1 //===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===/ 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 //===----------------------------------------------------------------------===/ 8 // 9 // This file implements semantic analysis for C++ templates. 10 //===----------------------------------------------------------------------===/ 11 12 #include "TreeTransform.h" 13 #include "clang/AST/ASTConsumer.h" 14 #include "clang/AST/ASTContext.h" 15 #include "clang/AST/ASTMutationListener.h" 16 #include "clang/AST/DeclFriend.h" 17 #include "clang/AST/DeclTemplate.h" 18 #include "clang/AST/Expr.h" 19 #include "clang/AST/ExprCXX.h" 20 #include "clang/AST/RecursiveASTVisitor.h" 21 #include "clang/AST/TypeVisitor.h" 22 #include "clang/Basic/LangOptions.h" 23 #include "clang/Basic/PartialDiagnostic.h" 24 #include "clang/Basic/TargetInfo.h" 25 #include "clang/Sema/DeclSpec.h" 26 #include "clang/Sema/Lookup.h" 27 #include "clang/Sema/ParsedTemplate.h" 28 #include "clang/Sema/Scope.h" 29 #include "clang/Sema/SemaInternal.h" 30 #include "clang/Sema/Template.h" 31 #include "clang/Sema/TemplateDeduction.h" 32 #include "llvm/ADT/SmallBitVector.h" 33 #include "llvm/ADT/SmallString.h" 34 #include "llvm/ADT/StringExtras.h" 35 using namespace clang; 36 using namespace sema; 37 38 // Exported for use by Parser. 39 SourceRange 40 clang::getTemplateParamsRange(TemplateParameterList const * const *Ps, 41 unsigned N) { 42 if (!N) return SourceRange(); 43 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc()); 44 } 45 46 /// \brief Determine whether the declaration found is acceptable as the name 47 /// of a template and, if so, return that template declaration. Otherwise, 48 /// returns NULL. 49 static NamedDecl *isAcceptableTemplateName(ASTContext &Context, 50 NamedDecl *Orig, 51 bool AllowFunctionTemplates) { 52 NamedDecl *D = Orig->getUnderlyingDecl(); 53 54 if (isa<TemplateDecl>(D)) { 55 if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D)) 56 return nullptr; 57 58 return Orig; 59 } 60 61 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) { 62 // C++ [temp.local]p1: 63 // Like normal (non-template) classes, class templates have an 64 // injected-class-name (Clause 9). The injected-class-name 65 // can be used with or without a template-argument-list. When 66 // it is used without a template-argument-list, it is 67 // equivalent to the injected-class-name followed by the 68 // template-parameters of the class template enclosed in 69 // <>. When it is used with a template-argument-list, it 70 // refers to the specified class template specialization, 71 // which could be the current specialization or another 72 // specialization. 73 if (Record->isInjectedClassName()) { 74 Record = cast<CXXRecordDecl>(Record->getDeclContext()); 75 if (Record->getDescribedClassTemplate()) 76 return Record->getDescribedClassTemplate(); 77 78 if (ClassTemplateSpecializationDecl *Spec 79 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) 80 return Spec->getSpecializedTemplate(); 81 } 82 83 return nullptr; 84 } 85 86 return nullptr; 87 } 88 89 void Sema::FilterAcceptableTemplateNames(LookupResult &R, 90 bool AllowFunctionTemplates) { 91 // The set of class templates we've already seen. 92 llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates; 93 LookupResult::Filter filter = R.makeFilter(); 94 while (filter.hasNext()) { 95 NamedDecl *Orig = filter.next(); 96 NamedDecl *Repl = isAcceptableTemplateName(Context, Orig, 97 AllowFunctionTemplates); 98 if (!Repl) 99 filter.erase(); 100 else if (Repl != Orig) { 101 102 // C++ [temp.local]p3: 103 // A lookup that finds an injected-class-name (10.2) can result in an 104 // ambiguity in certain cases (for example, if it is found in more than 105 // one base class). If all of the injected-class-names that are found 106 // refer to specializations of the same class template, and if the name 107 // is used as a template-name, the reference refers to the class 108 // template itself and not a specialization thereof, and is not 109 // ambiguous. 110 if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl)) 111 if (!ClassTemplates.insert(ClassTmpl).second) { 112 filter.erase(); 113 continue; 114 } 115 116 // FIXME: we promote access to public here as a workaround to 117 // the fact that LookupResult doesn't let us remember that we 118 // found this template through a particular injected class name, 119 // which means we end up doing nasty things to the invariants. 120 // Pretending that access is public is *much* safer. 121 filter.replace(Repl, AS_public); 122 } 123 } 124 filter.done(); 125 } 126 127 bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R, 128 bool AllowFunctionTemplates) { 129 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) 130 if (isAcceptableTemplateName(Context, *I, AllowFunctionTemplates)) 131 return true; 132 133 return false; 134 } 135 136 TemplateNameKind Sema::isTemplateName(Scope *S, 137 CXXScopeSpec &SS, 138 bool hasTemplateKeyword, 139 UnqualifiedId &Name, 140 ParsedType ObjectTypePtr, 141 bool EnteringContext, 142 TemplateTy &TemplateResult, 143 bool &MemberOfUnknownSpecialization) { 144 assert(getLangOpts().CPlusPlus && "No template names in C!"); 145 146 DeclarationName TName; 147 MemberOfUnknownSpecialization = false; 148 149 switch (Name.getKind()) { 150 case UnqualifiedId::IK_Identifier: 151 TName = DeclarationName(Name.Identifier); 152 break; 153 154 case UnqualifiedId::IK_OperatorFunctionId: 155 TName = Context.DeclarationNames.getCXXOperatorName( 156 Name.OperatorFunctionId.Operator); 157 break; 158 159 case UnqualifiedId::IK_LiteralOperatorId: 160 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier); 161 break; 162 163 default: 164 return TNK_Non_template; 165 } 166 167 QualType ObjectType = ObjectTypePtr.get(); 168 169 LookupResult R(*this, TName, Name.getLocStart(), LookupOrdinaryName); 170 LookupTemplateName(R, S, SS, ObjectType, EnteringContext, 171 MemberOfUnknownSpecialization); 172 if (R.empty()) return TNK_Non_template; 173 if (R.isAmbiguous()) { 174 // Suppress diagnostics; we'll redo this lookup later. 175 R.suppressDiagnostics(); 176 177 // FIXME: we might have ambiguous templates, in which case we 178 // should at least parse them properly! 179 return TNK_Non_template; 180 } 181 182 TemplateName Template; 183 TemplateNameKind TemplateKind; 184 185 unsigned ResultCount = R.end() - R.begin(); 186 if (ResultCount > 1) { 187 // We assume that we'll preserve the qualifier from a function 188 // template name in other ways. 189 Template = Context.getOverloadedTemplateName(R.begin(), R.end()); 190 TemplateKind = TNK_Function_template; 191 192 // We'll do this lookup again later. 193 R.suppressDiagnostics(); 194 } else { 195 TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl()); 196 197 if (SS.isSet() && !SS.isInvalid()) { 198 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 199 Template = Context.getQualifiedTemplateName(Qualifier, 200 hasTemplateKeyword, TD); 201 } else { 202 Template = TemplateName(TD); 203 } 204 205 if (isa<FunctionTemplateDecl>(TD)) { 206 TemplateKind = TNK_Function_template; 207 208 // We'll do this lookup again later. 209 R.suppressDiagnostics(); 210 } else { 211 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || 212 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD)); 213 TemplateKind = 214 isa<VarTemplateDecl>(TD) ? TNK_Var_template : TNK_Type_template; 215 } 216 } 217 218 TemplateResult = TemplateTy::make(Template); 219 return TemplateKind; 220 } 221 222 bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II, 223 SourceLocation IILoc, 224 Scope *S, 225 const CXXScopeSpec *SS, 226 TemplateTy &SuggestedTemplate, 227 TemplateNameKind &SuggestedKind) { 228 // We can't recover unless there's a dependent scope specifier preceding the 229 // template name. 230 // FIXME: Typo correction? 231 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) || 232 computeDeclContext(*SS)) 233 return false; 234 235 // The code is missing a 'template' keyword prior to the dependent template 236 // name. 237 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep(); 238 Diag(IILoc, diag::err_template_kw_missing) 239 << Qualifier << II.getName() 240 << FixItHint::CreateInsertion(IILoc, "template "); 241 SuggestedTemplate 242 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II)); 243 SuggestedKind = TNK_Dependent_template_name; 244 return true; 245 } 246 247 void Sema::LookupTemplateName(LookupResult &Found, 248 Scope *S, CXXScopeSpec &SS, 249 QualType ObjectType, 250 bool EnteringContext, 251 bool &MemberOfUnknownSpecialization) { 252 // Determine where to perform name lookup 253 MemberOfUnknownSpecialization = false; 254 DeclContext *LookupCtx = nullptr; 255 bool isDependent = false; 256 if (!ObjectType.isNull()) { 257 // This nested-name-specifier occurs in a member access expression, e.g., 258 // x->B::f, and we are looking into the type of the object. 259 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 260 LookupCtx = computeDeclContext(ObjectType); 261 isDependent = ObjectType->isDependentType(); 262 assert((isDependent || !ObjectType->isIncompleteType() || 263 ObjectType->castAs<TagType>()->isBeingDefined()) && 264 "Caller should have completed object type"); 265 266 // Template names cannot appear inside an Objective-C class or object type. 267 if (ObjectType->isObjCObjectOrInterfaceType()) { 268 Found.clear(); 269 return; 270 } 271 } else if (SS.isSet()) { 272 // This nested-name-specifier occurs after another nested-name-specifier, 273 // so long into the context associated with the prior nested-name-specifier. 274 LookupCtx = computeDeclContext(SS, EnteringContext); 275 isDependent = isDependentScopeSpecifier(SS); 276 277 // The declaration context must be complete. 278 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx)) 279 return; 280 } 281 282 bool ObjectTypeSearchedInScope = false; 283 bool AllowFunctionTemplatesInLookup = true; 284 if (LookupCtx) { 285 // Perform "qualified" name lookup into the declaration context we 286 // computed, which is either the type of the base of a member access 287 // expression or the declaration context associated with a prior 288 // nested-name-specifier. 289 LookupQualifiedName(Found, LookupCtx); 290 if (!ObjectType.isNull() && Found.empty()) { 291 // C++ [basic.lookup.classref]p1: 292 // In a class member access expression (5.2.5), if the . or -> token is 293 // immediately followed by an identifier followed by a <, the 294 // identifier must be looked up to determine whether the < is the 295 // beginning of a template argument list (14.2) or a less-than operator. 296 // The identifier is first looked up in the class of the object 297 // expression. If the identifier is not found, it is then looked up in 298 // the context of the entire postfix-expression and shall name a class 299 // or function template. 300 if (S) LookupName(Found, S); 301 ObjectTypeSearchedInScope = true; 302 AllowFunctionTemplatesInLookup = false; 303 } 304 } else if (isDependent && (!S || ObjectType.isNull())) { 305 // We cannot look into a dependent object type or nested nme 306 // specifier. 307 MemberOfUnknownSpecialization = true; 308 return; 309 } else { 310 // Perform unqualified name lookup in the current scope. 311 LookupName(Found, S); 312 313 if (!ObjectType.isNull()) 314 AllowFunctionTemplatesInLookup = false; 315 } 316 317 if (Found.empty() && !isDependent) { 318 // If we did not find any names, attempt to correct any typos. 319 DeclarationName Name = Found.getLookupName(); 320 Found.clear(); 321 // Simple filter callback that, for keywords, only accepts the C++ *_cast 322 auto FilterCCC = llvm::make_unique<CorrectionCandidateCallback>(); 323 FilterCCC->WantTypeSpecifiers = false; 324 FilterCCC->WantExpressionKeywords = false; 325 FilterCCC->WantRemainingKeywords = false; 326 FilterCCC->WantCXXNamedCasts = true; 327 if (TypoCorrection Corrected = CorrectTypo( 328 Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, 329 std::move(FilterCCC), CTK_ErrorRecovery, LookupCtx)) { 330 Found.setLookupName(Corrected.getCorrection()); 331 if (Corrected.getCorrectionDecl()) 332 Found.addDecl(Corrected.getCorrectionDecl()); 333 FilterAcceptableTemplateNames(Found); 334 if (!Found.empty()) { 335 if (LookupCtx) { 336 std::string CorrectedStr(Corrected.getAsString(getLangOpts())); 337 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && 338 Name.getAsString() == CorrectedStr; 339 diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest) 340 << Name << LookupCtx << DroppedSpecifier 341 << SS.getRange()); 342 } else { 343 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name); 344 } 345 } 346 } else { 347 Found.setLookupName(Name); 348 } 349 } 350 351 FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup); 352 if (Found.empty()) { 353 if (isDependent) 354 MemberOfUnknownSpecialization = true; 355 return; 356 } 357 358 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope && 359 !getLangOpts().CPlusPlus11) { 360 // C++03 [basic.lookup.classref]p1: 361 // [...] If the lookup in the class of the object expression finds a 362 // template, the name is also looked up in the context of the entire 363 // postfix-expression and [...] 364 // 365 // Note: C++11 does not perform this second lookup. 366 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(), 367 LookupOrdinaryName); 368 LookupName(FoundOuter, S); 369 FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false); 370 371 if (FoundOuter.empty()) { 372 // - if the name is not found, the name found in the class of the 373 // object expression is used, otherwise 374 } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>() || 375 FoundOuter.isAmbiguous()) { 376 // - if the name is found in the context of the entire 377 // postfix-expression and does not name a class template, the name 378 // found in the class of the object expression is used, otherwise 379 FoundOuter.clear(); 380 } else if (!Found.isSuppressingDiagnostics()) { 381 // - if the name found is a class template, it must refer to the same 382 // entity as the one found in the class of the object expression, 383 // otherwise the program is ill-formed. 384 if (!Found.isSingleResult() || 385 Found.getFoundDecl()->getCanonicalDecl() 386 != FoundOuter.getFoundDecl()->getCanonicalDecl()) { 387 Diag(Found.getNameLoc(), 388 diag::ext_nested_name_member_ref_lookup_ambiguous) 389 << Found.getLookupName() 390 << ObjectType; 391 Diag(Found.getRepresentativeDecl()->getLocation(), 392 diag::note_ambig_member_ref_object_type) 393 << ObjectType; 394 Diag(FoundOuter.getFoundDecl()->getLocation(), 395 diag::note_ambig_member_ref_scope); 396 397 // Recover by taking the template that we found in the object 398 // expression's type. 399 } 400 } 401 } 402 } 403 404 /// ActOnDependentIdExpression - Handle a dependent id-expression that 405 /// was just parsed. This is only possible with an explicit scope 406 /// specifier naming a dependent type. 407 ExprResult 408 Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS, 409 SourceLocation TemplateKWLoc, 410 const DeclarationNameInfo &NameInfo, 411 bool isAddressOfOperand, 412 const TemplateArgumentListInfo *TemplateArgs) { 413 DeclContext *DC = getFunctionLevelDeclContext(); 414 415 if (!isAddressOfOperand && 416 isa<CXXMethodDecl>(DC) && 417 cast<CXXMethodDecl>(DC)->isInstance()) { 418 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 419 420 // Since the 'this' expression is synthesized, we don't need to 421 // perform the double-lookup check. 422 NamedDecl *FirstQualifierInScope = nullptr; 423 424 return CXXDependentScopeMemberExpr::Create( 425 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true, 426 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc, 427 FirstQualifierInScope, NameInfo, TemplateArgs); 428 } 429 430 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs); 431 } 432 433 ExprResult 434 Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS, 435 SourceLocation TemplateKWLoc, 436 const DeclarationNameInfo &NameInfo, 437 const TemplateArgumentListInfo *TemplateArgs) { 438 return DependentScopeDeclRefExpr::Create( 439 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo, 440 TemplateArgs); 441 } 442 443 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining 444 /// that the template parameter 'PrevDecl' is being shadowed by a new 445 /// declaration at location Loc. Returns true to indicate that this is 446 /// an error, and false otherwise. 447 void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { 448 assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); 449 450 // Microsoft Visual C++ permits template parameters to be shadowed. 451 if (getLangOpts().MicrosoftExt) 452 return; 453 454 // C++ [temp.local]p4: 455 // A template-parameter shall not be redeclared within its 456 // scope (including nested scopes). 457 Diag(Loc, diag::err_template_param_shadow) 458 << cast<NamedDecl>(PrevDecl)->getDeclName(); 459 Diag(PrevDecl->getLocation(), diag::note_template_param_here); 460 return; 461 } 462 463 /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset 464 /// the parameter D to reference the templated declaration and return a pointer 465 /// to the template declaration. Otherwise, do nothing to D and return null. 466 TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) { 467 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) { 468 D = Temp->getTemplatedDecl(); 469 return Temp; 470 } 471 return nullptr; 472 } 473 474 ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion( 475 SourceLocation EllipsisLoc) const { 476 assert(Kind == Template && 477 "Only template template arguments can be pack expansions here"); 478 assert(getAsTemplate().get().containsUnexpandedParameterPack() && 479 "Template template argument pack expansion without packs"); 480 ParsedTemplateArgument Result(*this); 481 Result.EllipsisLoc = EllipsisLoc; 482 return Result; 483 } 484 485 static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef, 486 const ParsedTemplateArgument &Arg) { 487 488 switch (Arg.getKind()) { 489 case ParsedTemplateArgument::Type: { 490 TypeSourceInfo *DI; 491 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI); 492 if (!DI) 493 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation()); 494 return TemplateArgumentLoc(TemplateArgument(T), DI); 495 } 496 497 case ParsedTemplateArgument::NonType: { 498 Expr *E = static_cast<Expr *>(Arg.getAsExpr()); 499 return TemplateArgumentLoc(TemplateArgument(E), E); 500 } 501 502 case ParsedTemplateArgument::Template: { 503 TemplateName Template = Arg.getAsTemplate().get(); 504 TemplateArgument TArg; 505 if (Arg.getEllipsisLoc().isValid()) 506 TArg = TemplateArgument(Template, Optional<unsigned int>()); 507 else 508 TArg = Template; 509 return TemplateArgumentLoc(TArg, 510 Arg.getScopeSpec().getWithLocInContext( 511 SemaRef.Context), 512 Arg.getLocation(), 513 Arg.getEllipsisLoc()); 514 } 515 } 516 517 llvm_unreachable("Unhandled parsed template argument"); 518 } 519 520 /// \brief Translates template arguments as provided by the parser 521 /// into template arguments used by semantic analysis. 522 void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn, 523 TemplateArgumentListInfo &TemplateArgs) { 524 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I) 525 TemplateArgs.addArgument(translateTemplateArgument(*this, 526 TemplateArgsIn[I])); 527 } 528 529 static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S, 530 SourceLocation Loc, 531 IdentifierInfo *Name) { 532 NamedDecl *PrevDecl = SemaRef.LookupSingleName( 533 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForRedeclaration); 534 if (PrevDecl && PrevDecl->isTemplateParameter()) 535 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl); 536 } 537 538 /// ActOnTypeParameter - Called when a C++ template type parameter 539 /// (e.g., "typename T") has been parsed. Typename specifies whether 540 /// the keyword "typename" was used to declare the type parameter 541 /// (otherwise, "class" was used), and KeyLoc is the location of the 542 /// "class" or "typename" keyword. ParamName is the name of the 543 /// parameter (NULL indicates an unnamed template parameter) and 544 /// ParamNameLoc is the location of the parameter name (if any). 545 /// If the type parameter has a default argument, it will be added 546 /// later via ActOnTypeParameterDefault. 547 Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, 548 SourceLocation EllipsisLoc, 549 SourceLocation KeyLoc, 550 IdentifierInfo *ParamName, 551 SourceLocation ParamNameLoc, 552 unsigned Depth, unsigned Position, 553 SourceLocation EqualLoc, 554 ParsedType DefaultArg) { 555 assert(S->isTemplateParamScope() && 556 "Template type parameter not in template parameter scope!"); 557 bool Invalid = false; 558 559 SourceLocation Loc = ParamNameLoc; 560 if (!ParamName) 561 Loc = KeyLoc; 562 563 bool IsParameterPack = EllipsisLoc.isValid(); 564 TemplateTypeParmDecl *Param 565 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(), 566 KeyLoc, Loc, Depth, Position, ParamName, 567 Typename, IsParameterPack); 568 Param->setAccess(AS_public); 569 if (Invalid) 570 Param->setInvalidDecl(); 571 572 if (ParamName) { 573 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName); 574 575 // Add the template parameter into the current scope. 576 S->AddDecl(Param); 577 IdResolver.AddDecl(Param); 578 } 579 580 // C++0x [temp.param]p9: 581 // A default template-argument may be specified for any kind of 582 // template-parameter that is not a template parameter pack. 583 if (DefaultArg && IsParameterPack) { 584 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 585 DefaultArg = ParsedType(); 586 } 587 588 // Handle the default argument, if provided. 589 if (DefaultArg) { 590 TypeSourceInfo *DefaultTInfo; 591 GetTypeFromParser(DefaultArg, &DefaultTInfo); 592 593 assert(DefaultTInfo && "expected source information for type"); 594 595 // Check for unexpanded parameter packs. 596 if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo, 597 UPPC_DefaultArgument)) 598 return Param; 599 600 // Check the template argument itself. 601 if (CheckTemplateArgument(Param, DefaultTInfo)) { 602 Param->setInvalidDecl(); 603 return Param; 604 } 605 606 Param->setDefaultArgument(DefaultTInfo, false); 607 } 608 609 return Param; 610 } 611 612 /// \brief Check that the type of a non-type template parameter is 613 /// well-formed. 614 /// 615 /// \returns the (possibly-promoted) parameter type if valid; 616 /// otherwise, produces a diagnostic and returns a NULL type. 617 QualType 618 Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) { 619 // We don't allow variably-modified types as the type of non-type template 620 // parameters. 621 if (T->isVariablyModifiedType()) { 622 Diag(Loc, diag::err_variably_modified_nontype_template_param) 623 << T; 624 return QualType(); 625 } 626 627 // C++ [temp.param]p4: 628 // 629 // A non-type template-parameter shall have one of the following 630 // (optionally cv-qualified) types: 631 // 632 // -- integral or enumeration type, 633 if (T->isIntegralOrEnumerationType() || 634 // -- pointer to object or pointer to function, 635 T->isPointerType() || 636 // -- reference to object or reference to function, 637 T->isReferenceType() || 638 // -- pointer to member, 639 T->isMemberPointerType() || 640 // -- std::nullptr_t. 641 T->isNullPtrType() || 642 // If T is a dependent type, we can't do the check now, so we 643 // assume that it is well-formed. 644 T->isDependentType()) { 645 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter 646 // are ignored when determining its type. 647 return T.getUnqualifiedType(); 648 } 649 650 // C++ [temp.param]p8: 651 // 652 // A non-type template-parameter of type "array of T" or 653 // "function returning T" is adjusted to be of type "pointer to 654 // T" or "pointer to function returning T", respectively. 655 else if (T->isArrayType() || T->isFunctionType()) 656 return Context.getDecayedType(T); 657 658 Diag(Loc, diag::err_template_nontype_parm_bad_type) 659 << T; 660 661 return QualType(); 662 } 663 664 Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D, 665 unsigned Depth, 666 unsigned Position, 667 SourceLocation EqualLoc, 668 Expr *Default) { 669 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 670 QualType T = TInfo->getType(); 671 672 assert(S->isTemplateParamScope() && 673 "Non-type template parameter not in template parameter scope!"); 674 bool Invalid = false; 675 676 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc()); 677 if (T.isNull()) { 678 T = Context.IntTy; // Recover with an 'int' type. 679 Invalid = true; 680 } 681 682 IdentifierInfo *ParamName = D.getIdentifier(); 683 bool IsParameterPack = D.hasEllipsis(); 684 NonTypeTemplateParmDecl *Param 685 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 686 D.getLocStart(), 687 D.getIdentifierLoc(), 688 Depth, Position, ParamName, T, 689 IsParameterPack, TInfo); 690 Param->setAccess(AS_public); 691 692 if (Invalid) 693 Param->setInvalidDecl(); 694 695 if (ParamName) { 696 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(), 697 ParamName); 698 699 // Add the template parameter into the current scope. 700 S->AddDecl(Param); 701 IdResolver.AddDecl(Param); 702 } 703 704 // C++0x [temp.param]p9: 705 // A default template-argument may be specified for any kind of 706 // template-parameter that is not a template parameter pack. 707 if (Default && IsParameterPack) { 708 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 709 Default = nullptr; 710 } 711 712 // Check the well-formedness of the default template argument, if provided. 713 if (Default) { 714 // Check for unexpanded parameter packs. 715 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument)) 716 return Param; 717 718 TemplateArgument Converted; 719 ExprResult DefaultRes = 720 CheckTemplateArgument(Param, Param->getType(), Default, Converted); 721 if (DefaultRes.isInvalid()) { 722 Param->setInvalidDecl(); 723 return Param; 724 } 725 Default = DefaultRes.get(); 726 727 Param->setDefaultArgument(Default, false); 728 } 729 730 return Param; 731 } 732 733 /// ActOnTemplateTemplateParameter - Called when a C++ template template 734 /// parameter (e.g. T in template <template \<typename> class T> class array) 735 /// has been parsed. S is the current scope. 736 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S, 737 SourceLocation TmpLoc, 738 TemplateParameterList *Params, 739 SourceLocation EllipsisLoc, 740 IdentifierInfo *Name, 741 SourceLocation NameLoc, 742 unsigned Depth, 743 unsigned Position, 744 SourceLocation EqualLoc, 745 ParsedTemplateArgument Default) { 746 assert(S->isTemplateParamScope() && 747 "Template template parameter not in template parameter scope!"); 748 749 // Construct the parameter object. 750 bool IsParameterPack = EllipsisLoc.isValid(); 751 TemplateTemplateParmDecl *Param = 752 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 753 NameLoc.isInvalid()? TmpLoc : NameLoc, 754 Depth, Position, IsParameterPack, 755 Name, Params); 756 Param->setAccess(AS_public); 757 758 // If the template template parameter has a name, then link the identifier 759 // into the scope and lookup mechanisms. 760 if (Name) { 761 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name); 762 763 S->AddDecl(Param); 764 IdResolver.AddDecl(Param); 765 } 766 767 if (Params->size() == 0) { 768 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms) 769 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc()); 770 Param->setInvalidDecl(); 771 } 772 773 // C++0x [temp.param]p9: 774 // A default template-argument may be specified for any kind of 775 // template-parameter that is not a template parameter pack. 776 if (IsParameterPack && !Default.isInvalid()) { 777 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 778 Default = ParsedTemplateArgument(); 779 } 780 781 if (!Default.isInvalid()) { 782 // Check only that we have a template template argument. We don't want to 783 // try to check well-formedness now, because our template template parameter 784 // might have dependent types in its template parameters, which we wouldn't 785 // be able to match now. 786 // 787 // If none of the template template parameter's template arguments mention 788 // other template parameters, we could actually perform more checking here. 789 // However, it isn't worth doing. 790 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default); 791 if (DefaultArg.getArgument().getAsTemplate().isNull()) { 792 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template) 793 << DefaultArg.getSourceRange(); 794 return Param; 795 } 796 797 // Check for unexpanded parameter packs. 798 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(), 799 DefaultArg.getArgument().getAsTemplate(), 800 UPPC_DefaultArgument)) 801 return Param; 802 803 Param->setDefaultArgument(DefaultArg, false); 804 } 805 806 return Param; 807 } 808 809 /// ActOnTemplateParameterList - Builds a TemplateParameterList that 810 /// contains the template parameters in Params/NumParams. 811 TemplateParameterList * 812 Sema::ActOnTemplateParameterList(unsigned Depth, 813 SourceLocation ExportLoc, 814 SourceLocation TemplateLoc, 815 SourceLocation LAngleLoc, 816 Decl **Params, unsigned NumParams, 817 SourceLocation RAngleLoc) { 818 if (ExportLoc.isValid()) 819 Diag(ExportLoc, diag::warn_template_export_unsupported); 820 821 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc, 822 (NamedDecl**)Params, NumParams, 823 RAngleLoc); 824 } 825 826 static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) { 827 if (SS.isSet()) 828 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext())); 829 } 830 831 DeclResult 832 Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK, 833 SourceLocation KWLoc, CXXScopeSpec &SS, 834 IdentifierInfo *Name, SourceLocation NameLoc, 835 AttributeList *Attr, 836 TemplateParameterList *TemplateParams, 837 AccessSpecifier AS, SourceLocation ModulePrivateLoc, 838 SourceLocation FriendLoc, 839 unsigned NumOuterTemplateParamLists, 840 TemplateParameterList** OuterTemplateParamLists, 841 bool *SkipBody) { 842 assert(TemplateParams && TemplateParams->size() > 0 && 843 "No template parameters"); 844 assert(TUK != TUK_Reference && "Can only declare or define class templates"); 845 bool Invalid = false; 846 847 // Check that we can declare a template here. 848 if (CheckTemplateDeclScope(S, TemplateParams)) 849 return true; 850 851 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 852 assert(Kind != TTK_Enum && "can't build template of enumerated type"); 853 854 // There is no such thing as an unnamed class template. 855 if (!Name) { 856 Diag(KWLoc, diag::err_template_unnamed_class); 857 return true; 858 } 859 860 // Find any previous declaration with this name. For a friend with no 861 // scope explicitly specified, we only look for tag declarations (per 862 // C++11 [basic.lookup.elab]p2). 863 DeclContext *SemanticContext; 864 LookupResult Previous(*this, Name, NameLoc, 865 (SS.isEmpty() && TUK == TUK_Friend) 866 ? LookupTagName : LookupOrdinaryName, 867 ForRedeclaration); 868 if (SS.isNotEmpty() && !SS.isInvalid()) { 869 SemanticContext = computeDeclContext(SS, true); 870 if (!SemanticContext) { 871 // FIXME: Horrible, horrible hack! We can't currently represent this 872 // in the AST, and historically we have just ignored such friend 873 // class templates, so don't complain here. 874 Diag(NameLoc, TUK == TUK_Friend 875 ? diag::warn_template_qualified_friend_ignored 876 : diag::err_template_qualified_declarator_no_match) 877 << SS.getScopeRep() << SS.getRange(); 878 return TUK != TUK_Friend; 879 } 880 881 if (RequireCompleteDeclContext(SS, SemanticContext)) 882 return true; 883 884 // If we're adding a template to a dependent context, we may need to 885 // rebuilding some of the types used within the template parameter list, 886 // now that we know what the current instantiation is. 887 if (SemanticContext->isDependentContext()) { 888 ContextRAII SavedContext(*this, SemanticContext); 889 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams)) 890 Invalid = true; 891 } else if (TUK != TUK_Friend && TUK != TUK_Reference) 892 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc); 893 894 LookupQualifiedName(Previous, SemanticContext); 895 } else { 896 SemanticContext = CurContext; 897 LookupName(Previous, S); 898 } 899 900 if (Previous.isAmbiguous()) 901 return true; 902 903 NamedDecl *PrevDecl = nullptr; 904 if (Previous.begin() != Previous.end()) 905 PrevDecl = (*Previous.begin())->getUnderlyingDecl(); 906 907 // If there is a previous declaration with the same name, check 908 // whether this is a valid redeclaration. 909 ClassTemplateDecl *PrevClassTemplate 910 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl); 911 912 // We may have found the injected-class-name of a class template, 913 // class template partial specialization, or class template specialization. 914 // In these cases, grab the template that is being defined or specialized. 915 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) && 916 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) { 917 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext()); 918 PrevClassTemplate 919 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate(); 920 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) { 921 PrevClassTemplate 922 = cast<ClassTemplateSpecializationDecl>(PrevDecl) 923 ->getSpecializedTemplate(); 924 } 925 } 926 927 if (TUK == TUK_Friend) { 928 // C++ [namespace.memdef]p3: 929 // [...] When looking for a prior declaration of a class or a function 930 // declared as a friend, and when the name of the friend class or 931 // function is neither a qualified name nor a template-id, scopes outside 932 // the innermost enclosing namespace scope are not considered. 933 if (!SS.isSet()) { 934 DeclContext *OutermostContext = CurContext; 935 while (!OutermostContext->isFileContext()) 936 OutermostContext = OutermostContext->getLookupParent(); 937 938 if (PrevDecl && 939 (OutermostContext->Equals(PrevDecl->getDeclContext()) || 940 OutermostContext->Encloses(PrevDecl->getDeclContext()))) { 941 SemanticContext = PrevDecl->getDeclContext(); 942 } else { 943 // Declarations in outer scopes don't matter. However, the outermost 944 // context we computed is the semantic context for our new 945 // declaration. 946 PrevDecl = PrevClassTemplate = nullptr; 947 SemanticContext = OutermostContext; 948 949 // Check that the chosen semantic context doesn't already contain a 950 // declaration of this name as a non-tag type. 951 LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName, 952 ForRedeclaration); 953 DeclContext *LookupContext = SemanticContext; 954 while (LookupContext->isTransparentContext()) 955 LookupContext = LookupContext->getLookupParent(); 956 LookupQualifiedName(Previous, LookupContext); 957 958 if (Previous.isAmbiguous()) 959 return true; 960 961 if (Previous.begin() != Previous.end()) 962 PrevDecl = (*Previous.begin())->getUnderlyingDecl(); 963 } 964 } 965 } else if (PrevDecl && 966 !isDeclInScope(PrevDecl, SemanticContext, S, SS.isValid())) 967 PrevDecl = PrevClassTemplate = nullptr; 968 969 if (PrevClassTemplate) { 970 // Ensure that the template parameter lists are compatible. Skip this check 971 // for a friend in a dependent context: the template parameter list itself 972 // could be dependent. 973 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) && 974 !TemplateParameterListsAreEqual(TemplateParams, 975 PrevClassTemplate->getTemplateParameters(), 976 /*Complain=*/true, 977 TPL_TemplateMatch)) 978 return true; 979 980 // C++ [temp.class]p4: 981 // In a redeclaration, partial specialization, explicit 982 // specialization or explicit instantiation of a class template, 983 // the class-key shall agree in kind with the original class 984 // template declaration (7.1.5.3). 985 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl(); 986 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, 987 TUK == TUK_Definition, KWLoc, *Name)) { 988 Diag(KWLoc, diag::err_use_with_wrong_tag) 989 << Name 990 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName()); 991 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use); 992 Kind = PrevRecordDecl->getTagKind(); 993 } 994 995 // Check for redefinition of this class template. 996 if (TUK == TUK_Definition) { 997 if (TagDecl *Def = PrevRecordDecl->getDefinition()) { 998 // If we have a prior definition that is not visible, treat this as 999 // simply making that previous definition visible. 1000 NamedDecl *Hidden = nullptr; 1001 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) { 1002 *SkipBody = true; 1003 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate(); 1004 assert(Tmpl && "original definition of a class template is not a " 1005 "class template?"); 1006 if (auto *Listener = getASTMutationListener()) { 1007 Listener->RedefinedHiddenDefinition(Hidden, KWLoc); 1008 Listener->RedefinedHiddenDefinition(Tmpl, KWLoc); 1009 } 1010 Hidden->setHidden(false); 1011 Tmpl->setHidden(false); 1012 return Def; 1013 } 1014 1015 Diag(NameLoc, diag::err_redefinition) << Name; 1016 Diag(Def->getLocation(), diag::note_previous_definition); 1017 // FIXME: Would it make sense to try to "forget" the previous 1018 // definition, as part of error recovery? 1019 return true; 1020 } 1021 } 1022 } else if (PrevDecl && PrevDecl->isTemplateParameter()) { 1023 // Maybe we will complain about the shadowed template parameter. 1024 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 1025 // Just pretend that we didn't see the previous declaration. 1026 PrevDecl = nullptr; 1027 } else if (PrevDecl) { 1028 // C++ [temp]p5: 1029 // A class template shall not have the same name as any other 1030 // template, class, function, object, enumeration, enumerator, 1031 // namespace, or type in the same scope (3.3), except as specified 1032 // in (14.5.4). 1033 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 1034 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 1035 return true; 1036 } 1037 1038 // Check the template parameter list of this declaration, possibly 1039 // merging in the template parameter list from the previous class 1040 // template declaration. Skip this check for a friend in a dependent 1041 // context, because the template parameter list might be dependent. 1042 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) && 1043 CheckTemplateParameterList( 1044 TemplateParams, 1045 PrevClassTemplate ? PrevClassTemplate->getTemplateParameters() 1046 : nullptr, 1047 (SS.isSet() && SemanticContext && SemanticContext->isRecord() && 1048 SemanticContext->isDependentContext()) 1049 ? TPC_ClassTemplateMember 1050 : TUK == TUK_Friend ? TPC_FriendClassTemplate 1051 : TPC_ClassTemplate)) 1052 Invalid = true; 1053 1054 if (SS.isSet()) { 1055 // If the name of the template was qualified, we must be defining the 1056 // template out-of-line. 1057 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) { 1058 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match 1059 : diag::err_member_decl_does_not_match) 1060 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange(); 1061 Invalid = true; 1062 } 1063 } 1064 1065 CXXRecordDecl *NewClass = 1066 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name, 1067 PrevClassTemplate? 1068 PrevClassTemplate->getTemplatedDecl() : nullptr, 1069 /*DelayTypeCreation=*/true); 1070 SetNestedNameSpecifier(NewClass, SS); 1071 if (NumOuterTemplateParamLists > 0) 1072 NewClass->setTemplateParameterListsInfo(Context, 1073 NumOuterTemplateParamLists, 1074 OuterTemplateParamLists); 1075 1076 // Add alignment attributes if necessary; these attributes are checked when 1077 // the ASTContext lays out the structure. 1078 if (TUK == TUK_Definition) { 1079 AddAlignmentAttributesForRecord(NewClass); 1080 AddMsStructLayoutForRecord(NewClass); 1081 } 1082 1083 ClassTemplateDecl *NewTemplate 1084 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc, 1085 DeclarationName(Name), TemplateParams, 1086 NewClass, PrevClassTemplate); 1087 NewClass->setDescribedClassTemplate(NewTemplate); 1088 1089 if (ModulePrivateLoc.isValid()) 1090 NewTemplate->setModulePrivate(); 1091 1092 // Build the type for the class template declaration now. 1093 QualType T = NewTemplate->getInjectedClassNameSpecialization(); 1094 T = Context.getInjectedClassNameType(NewClass, T); 1095 assert(T->isDependentType() && "Class template type is not dependent?"); 1096 (void)T; 1097 1098 // If we are providing an explicit specialization of a member that is a 1099 // class template, make a note of that. 1100 if (PrevClassTemplate && 1101 PrevClassTemplate->getInstantiatedFromMemberTemplate()) 1102 PrevClassTemplate->setMemberSpecialization(); 1103 1104 // Set the access specifier. 1105 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord()) 1106 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS); 1107 1108 // Set the lexical context of these templates 1109 NewClass->setLexicalDeclContext(CurContext); 1110 NewTemplate->setLexicalDeclContext(CurContext); 1111 1112 if (TUK == TUK_Definition) 1113 NewClass->startDefinition(); 1114 1115 if (Attr) 1116 ProcessDeclAttributeList(S, NewClass, Attr); 1117 1118 if (PrevClassTemplate) 1119 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl()); 1120 1121 AddPushedVisibilityAttribute(NewClass); 1122 1123 if (TUK != TUK_Friend) { 1124 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes. 1125 Scope *Outer = S; 1126 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0) 1127 Outer = Outer->getParent(); 1128 PushOnScopeChains(NewTemplate, Outer); 1129 } else { 1130 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) { 1131 NewTemplate->setAccess(PrevClassTemplate->getAccess()); 1132 NewClass->setAccess(PrevClassTemplate->getAccess()); 1133 } 1134 1135 NewTemplate->setObjectOfFriendDecl(); 1136 1137 // Friend templates are visible in fairly strange ways. 1138 if (!CurContext->isDependentContext()) { 1139 DeclContext *DC = SemanticContext->getRedeclContext(); 1140 DC->makeDeclVisibleInContext(NewTemplate); 1141 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 1142 PushOnScopeChains(NewTemplate, EnclosingScope, 1143 /* AddToContext = */ false); 1144 } 1145 1146 FriendDecl *Friend = FriendDecl::Create( 1147 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc); 1148 Friend->setAccess(AS_public); 1149 CurContext->addDecl(Friend); 1150 } 1151 1152 if (Invalid) { 1153 NewTemplate->setInvalidDecl(); 1154 NewClass->setInvalidDecl(); 1155 } 1156 1157 ActOnDocumentableDecl(NewTemplate); 1158 1159 return NewTemplate; 1160 } 1161 1162 /// \brief Diagnose the presence of a default template argument on a 1163 /// template parameter, which is ill-formed in certain contexts. 1164 /// 1165 /// \returns true if the default template argument should be dropped. 1166 static bool DiagnoseDefaultTemplateArgument(Sema &S, 1167 Sema::TemplateParamListContext TPC, 1168 SourceLocation ParamLoc, 1169 SourceRange DefArgRange) { 1170 switch (TPC) { 1171 case Sema::TPC_ClassTemplate: 1172 case Sema::TPC_VarTemplate: 1173 case Sema::TPC_TypeAliasTemplate: 1174 return false; 1175 1176 case Sema::TPC_FunctionTemplate: 1177 case Sema::TPC_FriendFunctionTemplateDefinition: 1178 // C++ [temp.param]p9: 1179 // A default template-argument shall not be specified in a 1180 // function template declaration or a function template 1181 // definition [...] 1182 // If a friend function template declaration specifies a default 1183 // template-argument, that declaration shall be a definition and shall be 1184 // the only declaration of the function template in the translation unit. 1185 // (C++98/03 doesn't have this wording; see DR226). 1186 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ? 1187 diag::warn_cxx98_compat_template_parameter_default_in_function_template 1188 : diag::ext_template_parameter_default_in_function_template) 1189 << DefArgRange; 1190 return false; 1191 1192 case Sema::TPC_ClassTemplateMember: 1193 // C++0x [temp.param]p9: 1194 // A default template-argument shall not be specified in the 1195 // template-parameter-lists of the definition of a member of a 1196 // class template that appears outside of the member's class. 1197 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member) 1198 << DefArgRange; 1199 return true; 1200 1201 case Sema::TPC_FriendClassTemplate: 1202 case Sema::TPC_FriendFunctionTemplate: 1203 // C++ [temp.param]p9: 1204 // A default template-argument shall not be specified in a 1205 // friend template declaration. 1206 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template) 1207 << DefArgRange; 1208 return true; 1209 1210 // FIXME: C++0x [temp.param]p9 allows default template-arguments 1211 // for friend function templates if there is only a single 1212 // declaration (and it is a definition). Strange! 1213 } 1214 1215 llvm_unreachable("Invalid TemplateParamListContext!"); 1216 } 1217 1218 /// \brief Check for unexpanded parameter packs within the template parameters 1219 /// of a template template parameter, recursively. 1220 static bool DiagnoseUnexpandedParameterPacks(Sema &S, 1221 TemplateTemplateParmDecl *TTP) { 1222 // A template template parameter which is a parameter pack is also a pack 1223 // expansion. 1224 if (TTP->isParameterPack()) 1225 return false; 1226 1227 TemplateParameterList *Params = TTP->getTemplateParameters(); 1228 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 1229 NamedDecl *P = Params->getParam(I); 1230 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) { 1231 if (!NTTP->isParameterPack() && 1232 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(), 1233 NTTP->getTypeSourceInfo(), 1234 Sema::UPPC_NonTypeTemplateParameterType)) 1235 return true; 1236 1237 continue; 1238 } 1239 1240 if (TemplateTemplateParmDecl *InnerTTP 1241 = dyn_cast<TemplateTemplateParmDecl>(P)) 1242 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP)) 1243 return true; 1244 } 1245 1246 return false; 1247 } 1248 1249 /// \brief Checks the validity of a template parameter list, possibly 1250 /// considering the template parameter list from a previous 1251 /// declaration. 1252 /// 1253 /// If an "old" template parameter list is provided, it must be 1254 /// equivalent (per TemplateParameterListsAreEqual) to the "new" 1255 /// template parameter list. 1256 /// 1257 /// \param NewParams Template parameter list for a new template 1258 /// declaration. This template parameter list will be updated with any 1259 /// default arguments that are carried through from the previous 1260 /// template parameter list. 1261 /// 1262 /// \param OldParams If provided, template parameter list from a 1263 /// previous declaration of the same template. Default template 1264 /// arguments will be merged from the old template parameter list to 1265 /// the new template parameter list. 1266 /// 1267 /// \param TPC Describes the context in which we are checking the given 1268 /// template parameter list. 1269 /// 1270 /// \returns true if an error occurred, false otherwise. 1271 bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams, 1272 TemplateParameterList *OldParams, 1273 TemplateParamListContext TPC) { 1274 bool Invalid = false; 1275 1276 // C++ [temp.param]p10: 1277 // The set of default template-arguments available for use with a 1278 // template declaration or definition is obtained by merging the 1279 // default arguments from the definition (if in scope) and all 1280 // declarations in scope in the same way default function 1281 // arguments are (8.3.6). 1282 bool SawDefaultArgument = false; 1283 SourceLocation PreviousDefaultArgLoc; 1284 1285 // Dummy initialization to avoid warnings. 1286 TemplateParameterList::iterator OldParam = NewParams->end(); 1287 if (OldParams) 1288 OldParam = OldParams->begin(); 1289 1290 bool RemoveDefaultArguments = false; 1291 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 1292 NewParamEnd = NewParams->end(); 1293 NewParam != NewParamEnd; ++NewParam) { 1294 // Variables used to diagnose redundant default arguments 1295 bool RedundantDefaultArg = false; 1296 SourceLocation OldDefaultLoc; 1297 SourceLocation NewDefaultLoc; 1298 1299 // Variable used to diagnose missing default arguments 1300 bool MissingDefaultArg = false; 1301 1302 // Variable used to diagnose non-final parameter packs 1303 bool SawParameterPack = false; 1304 1305 if (TemplateTypeParmDecl *NewTypeParm 1306 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) { 1307 // Check the presence of a default argument here. 1308 if (NewTypeParm->hasDefaultArgument() && 1309 DiagnoseDefaultTemplateArgument(*this, TPC, 1310 NewTypeParm->getLocation(), 1311 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc() 1312 .getSourceRange())) 1313 NewTypeParm->removeDefaultArgument(); 1314 1315 // Merge default arguments for template type parameters. 1316 TemplateTypeParmDecl *OldTypeParm 1317 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr; 1318 1319 if (NewTypeParm->isParameterPack()) { 1320 assert(!NewTypeParm->hasDefaultArgument() && 1321 "Parameter packs can't have a default argument!"); 1322 SawParameterPack = true; 1323 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() && 1324 NewTypeParm->hasDefaultArgument()) { 1325 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc(); 1326 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc(); 1327 SawDefaultArgument = true; 1328 RedundantDefaultArg = true; 1329 PreviousDefaultArgLoc = NewDefaultLoc; 1330 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) { 1331 // Merge the default argument from the old declaration to the 1332 // new declaration. 1333 NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(), 1334 true); 1335 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc(); 1336 } else if (NewTypeParm->hasDefaultArgument()) { 1337 SawDefaultArgument = true; 1338 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc(); 1339 } else if (SawDefaultArgument) 1340 MissingDefaultArg = true; 1341 } else if (NonTypeTemplateParmDecl *NewNonTypeParm 1342 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) { 1343 // Check for unexpanded parameter packs. 1344 if (!NewNonTypeParm->isParameterPack() && 1345 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(), 1346 NewNonTypeParm->getTypeSourceInfo(), 1347 UPPC_NonTypeTemplateParameterType)) { 1348 Invalid = true; 1349 continue; 1350 } 1351 1352 // Check the presence of a default argument here. 1353 if (NewNonTypeParm->hasDefaultArgument() && 1354 DiagnoseDefaultTemplateArgument(*this, TPC, 1355 NewNonTypeParm->getLocation(), 1356 NewNonTypeParm->getDefaultArgument()->getSourceRange())) { 1357 NewNonTypeParm->removeDefaultArgument(); 1358 } 1359 1360 // Merge default arguments for non-type template parameters 1361 NonTypeTemplateParmDecl *OldNonTypeParm 1362 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr; 1363 if (NewNonTypeParm->isParameterPack()) { 1364 assert(!NewNonTypeParm->hasDefaultArgument() && 1365 "Parameter packs can't have a default argument!"); 1366 if (!NewNonTypeParm->isPackExpansion()) 1367 SawParameterPack = true; 1368 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() && 1369 NewNonTypeParm->hasDefaultArgument()) { 1370 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1371 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1372 SawDefaultArgument = true; 1373 RedundantDefaultArg = true; 1374 PreviousDefaultArgLoc = NewDefaultLoc; 1375 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) { 1376 // Merge the default argument from the old declaration to the 1377 // new declaration. 1378 // FIXME: We need to create a new kind of "default argument" 1379 // expression that points to a previous non-type template 1380 // parameter. 1381 NewNonTypeParm->setDefaultArgument( 1382 OldNonTypeParm->getDefaultArgument(), 1383 /*Inherited=*/ true); 1384 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1385 } else if (NewNonTypeParm->hasDefaultArgument()) { 1386 SawDefaultArgument = true; 1387 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1388 } else if (SawDefaultArgument) 1389 MissingDefaultArg = true; 1390 } else { 1391 TemplateTemplateParmDecl *NewTemplateParm 1392 = cast<TemplateTemplateParmDecl>(*NewParam); 1393 1394 // Check for unexpanded parameter packs, recursively. 1395 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) { 1396 Invalid = true; 1397 continue; 1398 } 1399 1400 // Check the presence of a default argument here. 1401 if (NewTemplateParm->hasDefaultArgument() && 1402 DiagnoseDefaultTemplateArgument(*this, TPC, 1403 NewTemplateParm->getLocation(), 1404 NewTemplateParm->getDefaultArgument().getSourceRange())) 1405 NewTemplateParm->removeDefaultArgument(); 1406 1407 // Merge default arguments for template template parameters 1408 TemplateTemplateParmDecl *OldTemplateParm 1409 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr; 1410 if (NewTemplateParm->isParameterPack()) { 1411 assert(!NewTemplateParm->hasDefaultArgument() && 1412 "Parameter packs can't have a default argument!"); 1413 if (!NewTemplateParm->isPackExpansion()) 1414 SawParameterPack = true; 1415 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() && 1416 NewTemplateParm->hasDefaultArgument()) { 1417 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation(); 1418 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation(); 1419 SawDefaultArgument = true; 1420 RedundantDefaultArg = true; 1421 PreviousDefaultArgLoc = NewDefaultLoc; 1422 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) { 1423 // Merge the default argument from the old declaration to the 1424 // new declaration. 1425 // FIXME: We need to create a new kind of "default argument" expression 1426 // that points to a previous template template parameter. 1427 NewTemplateParm->setDefaultArgument( 1428 OldTemplateParm->getDefaultArgument(), 1429 /*Inherited=*/ true); 1430 PreviousDefaultArgLoc 1431 = OldTemplateParm->getDefaultArgument().getLocation(); 1432 } else if (NewTemplateParm->hasDefaultArgument()) { 1433 SawDefaultArgument = true; 1434 PreviousDefaultArgLoc 1435 = NewTemplateParm->getDefaultArgument().getLocation(); 1436 } else if (SawDefaultArgument) 1437 MissingDefaultArg = true; 1438 } 1439 1440 // C++11 [temp.param]p11: 1441 // If a template parameter of a primary class template or alias template 1442 // is a template parameter pack, it shall be the last template parameter. 1443 if (SawParameterPack && (NewParam + 1) != NewParamEnd && 1444 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate || 1445 TPC == TPC_TypeAliasTemplate)) { 1446 Diag((*NewParam)->getLocation(), 1447 diag::err_template_param_pack_must_be_last_template_parameter); 1448 Invalid = true; 1449 } 1450 1451 if (RedundantDefaultArg) { 1452 // C++ [temp.param]p12: 1453 // A template-parameter shall not be given default arguments 1454 // by two different declarations in the same scope. 1455 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition); 1456 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg); 1457 Invalid = true; 1458 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) { 1459 // C++ [temp.param]p11: 1460 // If a template-parameter of a class template has a default 1461 // template-argument, each subsequent template-parameter shall either 1462 // have a default template-argument supplied or be a template parameter 1463 // pack. 1464 Diag((*NewParam)->getLocation(), 1465 diag::err_template_param_default_arg_missing); 1466 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg); 1467 Invalid = true; 1468 RemoveDefaultArguments = true; 1469 } 1470 1471 // If we have an old template parameter list that we're merging 1472 // in, move on to the next parameter. 1473 if (OldParams) 1474 ++OldParam; 1475 } 1476 1477 // We were missing some default arguments at the end of the list, so remove 1478 // all of the default arguments. 1479 if (RemoveDefaultArguments) { 1480 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 1481 NewParamEnd = NewParams->end(); 1482 NewParam != NewParamEnd; ++NewParam) { 1483 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam)) 1484 TTP->removeDefaultArgument(); 1485 else if (NonTypeTemplateParmDecl *NTTP 1486 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) 1487 NTTP->removeDefaultArgument(); 1488 else 1489 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument(); 1490 } 1491 } 1492 1493 return Invalid; 1494 } 1495 1496 namespace { 1497 1498 /// A class which looks for a use of a certain level of template 1499 /// parameter. 1500 struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> { 1501 typedef RecursiveASTVisitor<DependencyChecker> super; 1502 1503 unsigned Depth; 1504 bool Match; 1505 SourceLocation MatchLoc; 1506 1507 DependencyChecker(unsigned Depth) : Depth(Depth), Match(false) {} 1508 1509 DependencyChecker(TemplateParameterList *Params) : Match(false) { 1510 NamedDecl *ND = Params->getParam(0); 1511 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) { 1512 Depth = PD->getDepth(); 1513 } else if (NonTypeTemplateParmDecl *PD = 1514 dyn_cast<NonTypeTemplateParmDecl>(ND)) { 1515 Depth = PD->getDepth(); 1516 } else { 1517 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth(); 1518 } 1519 } 1520 1521 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) { 1522 if (ParmDepth >= Depth) { 1523 Match = true; 1524 MatchLoc = Loc; 1525 return true; 1526 } 1527 return false; 1528 } 1529 1530 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) { 1531 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc()); 1532 } 1533 1534 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) { 1535 return !Matches(T->getDepth()); 1536 } 1537 1538 bool TraverseTemplateName(TemplateName N) { 1539 if (TemplateTemplateParmDecl *PD = 1540 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl())) 1541 if (Matches(PD->getDepth())) 1542 return false; 1543 return super::TraverseTemplateName(N); 1544 } 1545 1546 bool VisitDeclRefExpr(DeclRefExpr *E) { 1547 if (NonTypeTemplateParmDecl *PD = 1548 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) 1549 if (Matches(PD->getDepth(), E->getExprLoc())) 1550 return false; 1551 return super::VisitDeclRefExpr(E); 1552 } 1553 1554 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) { 1555 return TraverseType(T->getReplacementType()); 1556 } 1557 1558 bool 1559 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) { 1560 return TraverseTemplateArgument(T->getArgumentPack()); 1561 } 1562 1563 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) { 1564 return TraverseType(T->getInjectedSpecializationType()); 1565 } 1566 }; 1567 } 1568 1569 /// Determines whether a given type depends on the given parameter 1570 /// list. 1571 static bool 1572 DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) { 1573 DependencyChecker Checker(Params); 1574 Checker.TraverseType(T); 1575 return Checker.Match; 1576 } 1577 1578 // Find the source range corresponding to the named type in the given 1579 // nested-name-specifier, if any. 1580 static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context, 1581 QualType T, 1582 const CXXScopeSpec &SS) { 1583 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data()); 1584 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) { 1585 if (const Type *CurType = NNS->getAsType()) { 1586 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0))) 1587 return NNSLoc.getTypeLoc().getSourceRange(); 1588 } else 1589 break; 1590 1591 NNSLoc = NNSLoc.getPrefix(); 1592 } 1593 1594 return SourceRange(); 1595 } 1596 1597 /// \brief Match the given template parameter lists to the given scope 1598 /// specifier, returning the template parameter list that applies to the 1599 /// name. 1600 /// 1601 /// \param DeclStartLoc the start of the declaration that has a scope 1602 /// specifier or a template parameter list. 1603 /// 1604 /// \param DeclLoc The location of the declaration itself. 1605 /// 1606 /// \param SS the scope specifier that will be matched to the given template 1607 /// parameter lists. This scope specifier precedes a qualified name that is 1608 /// being declared. 1609 /// 1610 /// \param TemplateId The template-id following the scope specifier, if there 1611 /// is one. Used to check for a missing 'template<>'. 1612 /// 1613 /// \param ParamLists the template parameter lists, from the outermost to the 1614 /// innermost template parameter lists. 1615 /// 1616 /// \param IsFriend Whether to apply the slightly different rules for 1617 /// matching template parameters to scope specifiers in friend 1618 /// declarations. 1619 /// 1620 /// \param IsExplicitSpecialization will be set true if the entity being 1621 /// declared is an explicit specialization, false otherwise. 1622 /// 1623 /// \returns the template parameter list, if any, that corresponds to the 1624 /// name that is preceded by the scope specifier @p SS. This template 1625 /// parameter list may have template parameters (if we're declaring a 1626 /// template) or may have no template parameters (if we're declaring a 1627 /// template specialization), or may be NULL (if what we're declaring isn't 1628 /// itself a template). 1629 TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier( 1630 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS, 1631 TemplateIdAnnotation *TemplateId, 1632 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend, 1633 bool &IsExplicitSpecialization, bool &Invalid) { 1634 IsExplicitSpecialization = false; 1635 Invalid = false; 1636 1637 // The sequence of nested types to which we will match up the template 1638 // parameter lists. We first build this list by starting with the type named 1639 // by the nested-name-specifier and walking out until we run out of types. 1640 SmallVector<QualType, 4> NestedTypes; 1641 QualType T; 1642 if (SS.getScopeRep()) { 1643 if (CXXRecordDecl *Record 1644 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true))) 1645 T = Context.getTypeDeclType(Record); 1646 else 1647 T = QualType(SS.getScopeRep()->getAsType(), 0); 1648 } 1649 1650 // If we found an explicit specialization that prevents us from needing 1651 // 'template<>' headers, this will be set to the location of that 1652 // explicit specialization. 1653 SourceLocation ExplicitSpecLoc; 1654 1655 while (!T.isNull()) { 1656 NestedTypes.push_back(T); 1657 1658 // Retrieve the parent of a record type. 1659 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) { 1660 // If this type is an explicit specialization, we're done. 1661 if (ClassTemplateSpecializationDecl *Spec 1662 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) { 1663 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) && 1664 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) { 1665 ExplicitSpecLoc = Spec->getLocation(); 1666 break; 1667 } 1668 } else if (Record->getTemplateSpecializationKind() 1669 == TSK_ExplicitSpecialization) { 1670 ExplicitSpecLoc = Record->getLocation(); 1671 break; 1672 } 1673 1674 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent())) 1675 T = Context.getTypeDeclType(Parent); 1676 else 1677 T = QualType(); 1678 continue; 1679 } 1680 1681 if (const TemplateSpecializationType *TST 1682 = T->getAs<TemplateSpecializationType>()) { 1683 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) { 1684 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext())) 1685 T = Context.getTypeDeclType(Parent); 1686 else 1687 T = QualType(); 1688 continue; 1689 } 1690 } 1691 1692 // Look one step prior in a dependent template specialization type. 1693 if (const DependentTemplateSpecializationType *DependentTST 1694 = T->getAs<DependentTemplateSpecializationType>()) { 1695 if (NestedNameSpecifier *NNS = DependentTST->getQualifier()) 1696 T = QualType(NNS->getAsType(), 0); 1697 else 1698 T = QualType(); 1699 continue; 1700 } 1701 1702 // Look one step prior in a dependent name type. 1703 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){ 1704 if (NestedNameSpecifier *NNS = DependentName->getQualifier()) 1705 T = QualType(NNS->getAsType(), 0); 1706 else 1707 T = QualType(); 1708 continue; 1709 } 1710 1711 // Retrieve the parent of an enumeration type. 1712 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1713 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization 1714 // check here. 1715 EnumDecl *Enum = EnumT->getDecl(); 1716 1717 // Get to the parent type. 1718 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent())) 1719 T = Context.getTypeDeclType(Parent); 1720 else 1721 T = QualType(); 1722 continue; 1723 } 1724 1725 T = QualType(); 1726 } 1727 // Reverse the nested types list, since we want to traverse from the outermost 1728 // to the innermost while checking template-parameter-lists. 1729 std::reverse(NestedTypes.begin(), NestedTypes.end()); 1730 1731 // C++0x [temp.expl.spec]p17: 1732 // A member or a member template may be nested within many 1733 // enclosing class templates. In an explicit specialization for 1734 // such a member, the member declaration shall be preceded by a 1735 // template<> for each enclosing class template that is 1736 // explicitly specialized. 1737 bool SawNonEmptyTemplateParameterList = false; 1738 1739 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) { 1740 if (SawNonEmptyTemplateParameterList) { 1741 Diag(DeclLoc, diag::err_specialize_member_of_template) 1742 << !Recovery << Range; 1743 Invalid = true; 1744 IsExplicitSpecialization = false; 1745 return true; 1746 } 1747 1748 return false; 1749 }; 1750 1751 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) { 1752 // Check that we can have an explicit specialization here. 1753 if (CheckExplicitSpecialization(Range, true)) 1754 return true; 1755 1756 // We don't have a template header, but we should. 1757 SourceLocation ExpectedTemplateLoc; 1758 if (!ParamLists.empty()) 1759 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc(); 1760 else 1761 ExpectedTemplateLoc = DeclStartLoc; 1762 1763 Diag(DeclLoc, diag::err_template_spec_needs_header) 1764 << Range 1765 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> "); 1766 return false; 1767 }; 1768 1769 unsigned ParamIdx = 0; 1770 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes; 1771 ++TypeIdx) { 1772 T = NestedTypes[TypeIdx]; 1773 1774 // Whether we expect a 'template<>' header. 1775 bool NeedEmptyTemplateHeader = false; 1776 1777 // Whether we expect a template header with parameters. 1778 bool NeedNonemptyTemplateHeader = false; 1779 1780 // For a dependent type, the set of template parameters that we 1781 // expect to see. 1782 TemplateParameterList *ExpectedTemplateParams = nullptr; 1783 1784 // C++0x [temp.expl.spec]p15: 1785 // A member or a member template may be nested within many enclosing 1786 // class templates. In an explicit specialization for such a member, the 1787 // member declaration shall be preceded by a template<> for each 1788 // enclosing class template that is explicitly specialized. 1789 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) { 1790 if (ClassTemplatePartialSpecializationDecl *Partial 1791 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) { 1792 ExpectedTemplateParams = Partial->getTemplateParameters(); 1793 NeedNonemptyTemplateHeader = true; 1794 } else if (Record->isDependentType()) { 1795 if (Record->getDescribedClassTemplate()) { 1796 ExpectedTemplateParams = Record->getDescribedClassTemplate() 1797 ->getTemplateParameters(); 1798 NeedNonemptyTemplateHeader = true; 1799 } 1800 } else if (ClassTemplateSpecializationDecl *Spec 1801 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) { 1802 // C++0x [temp.expl.spec]p4: 1803 // Members of an explicitly specialized class template are defined 1804 // in the same manner as members of normal classes, and not using 1805 // the template<> syntax. 1806 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization) 1807 NeedEmptyTemplateHeader = true; 1808 else 1809 continue; 1810 } else if (Record->getTemplateSpecializationKind()) { 1811 if (Record->getTemplateSpecializationKind() 1812 != TSK_ExplicitSpecialization && 1813 TypeIdx == NumTypes - 1) 1814 IsExplicitSpecialization = true; 1815 1816 continue; 1817 } 1818 } else if (const TemplateSpecializationType *TST 1819 = T->getAs<TemplateSpecializationType>()) { 1820 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) { 1821 ExpectedTemplateParams = Template->getTemplateParameters(); 1822 NeedNonemptyTemplateHeader = true; 1823 } 1824 } else if (T->getAs<DependentTemplateSpecializationType>()) { 1825 // FIXME: We actually could/should check the template arguments here 1826 // against the corresponding template parameter list. 1827 NeedNonemptyTemplateHeader = false; 1828 } 1829 1830 // C++ [temp.expl.spec]p16: 1831 // In an explicit specialization declaration for a member of a class 1832 // template or a member template that ap- pears in namespace scope, the 1833 // member template and some of its enclosing class templates may remain 1834 // unspecialized, except that the declaration shall not explicitly 1835 // specialize a class member template if its en- closing class templates 1836 // are not explicitly specialized as well. 1837 if (ParamIdx < ParamLists.size()) { 1838 if (ParamLists[ParamIdx]->size() == 0) { 1839 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(), 1840 false)) 1841 return nullptr; 1842 } else 1843 SawNonEmptyTemplateParameterList = true; 1844 } 1845 1846 if (NeedEmptyTemplateHeader) { 1847 // If we're on the last of the types, and we need a 'template<>' header 1848 // here, then it's an explicit specialization. 1849 if (TypeIdx == NumTypes - 1) 1850 IsExplicitSpecialization = true; 1851 1852 if (ParamIdx < ParamLists.size()) { 1853 if (ParamLists[ParamIdx]->size() > 0) { 1854 // The header has template parameters when it shouldn't. Complain. 1855 Diag(ParamLists[ParamIdx]->getTemplateLoc(), 1856 diag::err_template_param_list_matches_nontemplate) 1857 << T 1858 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(), 1859 ParamLists[ParamIdx]->getRAngleLoc()) 1860 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS); 1861 Invalid = true; 1862 return nullptr; 1863 } 1864 1865 // Consume this template header. 1866 ++ParamIdx; 1867 continue; 1868 } 1869 1870 if (!IsFriend) 1871 if (DiagnoseMissingExplicitSpecialization( 1872 getRangeOfTypeInNestedNameSpecifier(Context, T, SS))) 1873 return nullptr; 1874 1875 continue; 1876 } 1877 1878 if (NeedNonemptyTemplateHeader) { 1879 // In friend declarations we can have template-ids which don't 1880 // depend on the corresponding template parameter lists. But 1881 // assume that empty parameter lists are supposed to match this 1882 // template-id. 1883 if (IsFriend && T->isDependentType()) { 1884 if (ParamIdx < ParamLists.size() && 1885 DependsOnTemplateParameters(T, ParamLists[ParamIdx])) 1886 ExpectedTemplateParams = nullptr; 1887 else 1888 continue; 1889 } 1890 1891 if (ParamIdx < ParamLists.size()) { 1892 // Check the template parameter list, if we can. 1893 if (ExpectedTemplateParams && 1894 !TemplateParameterListsAreEqual(ParamLists[ParamIdx], 1895 ExpectedTemplateParams, 1896 true, TPL_TemplateMatch)) 1897 Invalid = true; 1898 1899 if (!Invalid && 1900 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr, 1901 TPC_ClassTemplateMember)) 1902 Invalid = true; 1903 1904 ++ParamIdx; 1905 continue; 1906 } 1907 1908 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters) 1909 << T 1910 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS); 1911 Invalid = true; 1912 continue; 1913 } 1914 } 1915 1916 // If there were at least as many template-ids as there were template 1917 // parameter lists, then there are no template parameter lists remaining for 1918 // the declaration itself. 1919 if (ParamIdx >= ParamLists.size()) { 1920 if (TemplateId && !IsFriend) { 1921 // We don't have a template header for the declaration itself, but we 1922 // should. 1923 IsExplicitSpecialization = true; 1924 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc, 1925 TemplateId->RAngleLoc)); 1926 1927 // Fabricate an empty template parameter list for the invented header. 1928 return TemplateParameterList::Create(Context, SourceLocation(), 1929 SourceLocation(), nullptr, 0, 1930 SourceLocation()); 1931 } 1932 1933 return nullptr; 1934 } 1935 1936 // If there were too many template parameter lists, complain about that now. 1937 if (ParamIdx < ParamLists.size() - 1) { 1938 bool HasAnyExplicitSpecHeader = false; 1939 bool AllExplicitSpecHeaders = true; 1940 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) { 1941 if (ParamLists[I]->size() == 0) 1942 HasAnyExplicitSpecHeader = true; 1943 else 1944 AllExplicitSpecHeaders = false; 1945 } 1946 1947 Diag(ParamLists[ParamIdx]->getTemplateLoc(), 1948 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers 1949 : diag::err_template_spec_extra_headers) 1950 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(), 1951 ParamLists[ParamLists.size() - 2]->getRAngleLoc()); 1952 1953 // If there was a specialization somewhere, such that 'template<>' is 1954 // not required, and there were any 'template<>' headers, note where the 1955 // specialization occurred. 1956 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader) 1957 Diag(ExplicitSpecLoc, 1958 diag::note_explicit_template_spec_does_not_need_header) 1959 << NestedTypes.back(); 1960 1961 // We have a template parameter list with no corresponding scope, which 1962 // means that the resulting template declaration can't be instantiated 1963 // properly (we'll end up with dependent nodes when we shouldn't). 1964 if (!AllExplicitSpecHeaders) 1965 Invalid = true; 1966 } 1967 1968 // C++ [temp.expl.spec]p16: 1969 // In an explicit specialization declaration for a member of a class 1970 // template or a member template that ap- pears in namespace scope, the 1971 // member template and some of its enclosing class templates may remain 1972 // unspecialized, except that the declaration shall not explicitly 1973 // specialize a class member template if its en- closing class templates 1974 // are not explicitly specialized as well. 1975 if (ParamLists.back()->size() == 0 && 1976 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(), 1977 false)) 1978 return nullptr; 1979 1980 // Return the last template parameter list, which corresponds to the 1981 // entity being declared. 1982 return ParamLists.back(); 1983 } 1984 1985 void Sema::NoteAllFoundTemplates(TemplateName Name) { 1986 if (TemplateDecl *Template = Name.getAsTemplateDecl()) { 1987 Diag(Template->getLocation(), diag::note_template_declared_here) 1988 << (isa<FunctionTemplateDecl>(Template) 1989 ? 0 1990 : isa<ClassTemplateDecl>(Template) 1991 ? 1 1992 : isa<VarTemplateDecl>(Template) 1993 ? 2 1994 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4) 1995 << Template->getDeclName(); 1996 return; 1997 } 1998 1999 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) { 2000 for (OverloadedTemplateStorage::iterator I = OST->begin(), 2001 IEnd = OST->end(); 2002 I != IEnd; ++I) 2003 Diag((*I)->getLocation(), diag::note_template_declared_here) 2004 << 0 << (*I)->getDeclName(); 2005 2006 return; 2007 } 2008 } 2009 2010 QualType Sema::CheckTemplateIdType(TemplateName Name, 2011 SourceLocation TemplateLoc, 2012 TemplateArgumentListInfo &TemplateArgs) { 2013 DependentTemplateName *DTN 2014 = Name.getUnderlying().getAsDependentTemplateName(); 2015 if (DTN && DTN->isIdentifier()) 2016 // When building a template-id where the template-name is dependent, 2017 // assume the template is a type template. Either our assumption is 2018 // correct, or the code is ill-formed and will be diagnosed when the 2019 // dependent name is substituted. 2020 return Context.getDependentTemplateSpecializationType(ETK_None, 2021 DTN->getQualifier(), 2022 DTN->getIdentifier(), 2023 TemplateArgs); 2024 2025 TemplateDecl *Template = Name.getAsTemplateDecl(); 2026 if (!Template || isa<FunctionTemplateDecl>(Template) || 2027 isa<VarTemplateDecl>(Template)) { 2028 // We might have a substituted template template parameter pack. If so, 2029 // build a template specialization type for it. 2030 if (Name.getAsSubstTemplateTemplateParmPack()) 2031 return Context.getTemplateSpecializationType(Name, TemplateArgs); 2032 2033 Diag(TemplateLoc, diag::err_template_id_not_a_type) 2034 << Name; 2035 NoteAllFoundTemplates(Name); 2036 return QualType(); 2037 } 2038 2039 // Check that the template argument list is well-formed for this 2040 // template. 2041 SmallVector<TemplateArgument, 4> Converted; 2042 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs, 2043 false, Converted)) 2044 return QualType(); 2045 2046 QualType CanonType; 2047 2048 bool InstantiationDependent = false; 2049 if (TypeAliasTemplateDecl *AliasTemplate = 2050 dyn_cast<TypeAliasTemplateDecl>(Template)) { 2051 // Find the canonical type for this type alias template specialization. 2052 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl(); 2053 if (Pattern->isInvalidDecl()) 2054 return QualType(); 2055 2056 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2057 Converted.data(), Converted.size()); 2058 2059 // Only substitute for the innermost template argument list. 2060 MultiLevelTemplateArgumentList TemplateArgLists; 2061 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); 2062 unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth(); 2063 for (unsigned I = 0; I < Depth; ++I) 2064 TemplateArgLists.addOuterTemplateArguments(None); 2065 2066 LocalInstantiationScope Scope(*this); 2067 InstantiatingTemplate Inst(*this, TemplateLoc, Template); 2068 if (Inst.isInvalid()) 2069 return QualType(); 2070 2071 CanonType = SubstType(Pattern->getUnderlyingType(), 2072 TemplateArgLists, AliasTemplate->getLocation(), 2073 AliasTemplate->getDeclName()); 2074 if (CanonType.isNull()) 2075 return QualType(); 2076 } else if (Name.isDependent() || 2077 TemplateSpecializationType::anyDependentTemplateArguments( 2078 TemplateArgs, InstantiationDependent)) { 2079 // This class template specialization is a dependent 2080 // type. Therefore, its canonical type is another class template 2081 // specialization type that contains all of the converted 2082 // arguments in canonical form. This ensures that, e.g., A<T> and 2083 // A<T, T> have identical types when A is declared as: 2084 // 2085 // template<typename T, typename U = T> struct A; 2086 TemplateName CanonName = Context.getCanonicalTemplateName(Name); 2087 CanonType = Context.getTemplateSpecializationType(CanonName, 2088 Converted.data(), 2089 Converted.size()); 2090 2091 // FIXME: CanonType is not actually the canonical type, and unfortunately 2092 // it is a TemplateSpecializationType that we will never use again. 2093 // In the future, we need to teach getTemplateSpecializationType to only 2094 // build the canonical type and return that to us. 2095 CanonType = Context.getCanonicalType(CanonType); 2096 2097 // This might work out to be a current instantiation, in which 2098 // case the canonical type needs to be the InjectedClassNameType. 2099 // 2100 // TODO: in theory this could be a simple hashtable lookup; most 2101 // changes to CurContext don't change the set of current 2102 // instantiations. 2103 if (isa<ClassTemplateDecl>(Template)) { 2104 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { 2105 // If we get out to a namespace, we're done. 2106 if (Ctx->isFileContext()) break; 2107 2108 // If this isn't a record, keep looking. 2109 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx); 2110 if (!Record) continue; 2111 2112 // Look for one of the two cases with InjectedClassNameTypes 2113 // and check whether it's the same template. 2114 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) && 2115 !Record->getDescribedClassTemplate()) 2116 continue; 2117 2118 // Fetch the injected class name type and check whether its 2119 // injected type is equal to the type we just built. 2120 QualType ICNT = Context.getTypeDeclType(Record); 2121 QualType Injected = cast<InjectedClassNameType>(ICNT) 2122 ->getInjectedSpecializationType(); 2123 2124 if (CanonType != Injected->getCanonicalTypeInternal()) 2125 continue; 2126 2127 // If so, the canonical type of this TST is the injected 2128 // class name type of the record we just found. 2129 assert(ICNT.isCanonical()); 2130 CanonType = ICNT; 2131 break; 2132 } 2133 } 2134 } else if (ClassTemplateDecl *ClassTemplate 2135 = dyn_cast<ClassTemplateDecl>(Template)) { 2136 // Find the class template specialization declaration that 2137 // corresponds to these arguments. 2138 void *InsertPos = nullptr; 2139 ClassTemplateSpecializationDecl *Decl 2140 = ClassTemplate->findSpecialization(Converted, InsertPos); 2141 if (!Decl) { 2142 // This is the first time we have referenced this class template 2143 // specialization. Create the canonical declaration and add it to 2144 // the set of specializations. 2145 Decl = ClassTemplateSpecializationDecl::Create(Context, 2146 ClassTemplate->getTemplatedDecl()->getTagKind(), 2147 ClassTemplate->getDeclContext(), 2148 ClassTemplate->getTemplatedDecl()->getLocStart(), 2149 ClassTemplate->getLocation(), 2150 ClassTemplate, 2151 Converted.data(), 2152 Converted.size(), nullptr); 2153 ClassTemplate->AddSpecialization(Decl, InsertPos); 2154 if (ClassTemplate->isOutOfLine()) 2155 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext()); 2156 } 2157 2158 // Diagnose uses of this specialization. 2159 (void)DiagnoseUseOfDecl(Decl, TemplateLoc); 2160 2161 CanonType = Context.getTypeDeclType(Decl); 2162 assert(isa<RecordType>(CanonType) && 2163 "type of non-dependent specialization is not a RecordType"); 2164 } 2165 2166 // Build the fully-sugared type for this class template 2167 // specialization, which refers back to the class template 2168 // specialization we created or found. 2169 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType); 2170 } 2171 2172 TypeResult 2173 Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc, 2174 TemplateTy TemplateD, SourceLocation TemplateLoc, 2175 SourceLocation LAngleLoc, 2176 ASTTemplateArgsPtr TemplateArgsIn, 2177 SourceLocation RAngleLoc, 2178 bool IsCtorOrDtorName) { 2179 if (SS.isInvalid()) 2180 return true; 2181 2182 TemplateName Template = TemplateD.get(); 2183 2184 // Translate the parser's template argument list in our AST format. 2185 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 2186 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 2187 2188 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) { 2189 QualType T 2190 = Context.getDependentTemplateSpecializationType(ETK_None, 2191 DTN->getQualifier(), 2192 DTN->getIdentifier(), 2193 TemplateArgs); 2194 // Build type-source information. 2195 TypeLocBuilder TLB; 2196 DependentTemplateSpecializationTypeLoc SpecTL 2197 = TLB.push<DependentTemplateSpecializationTypeLoc>(T); 2198 SpecTL.setElaboratedKeywordLoc(SourceLocation()); 2199 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 2200 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 2201 SpecTL.setTemplateNameLoc(TemplateLoc); 2202 SpecTL.setLAngleLoc(LAngleLoc); 2203 SpecTL.setRAngleLoc(RAngleLoc); 2204 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I) 2205 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 2206 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T)); 2207 } 2208 2209 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); 2210 2211 if (Result.isNull()) 2212 return true; 2213 2214 // Build type-source information. 2215 TypeLocBuilder TLB; 2216 TemplateSpecializationTypeLoc SpecTL 2217 = TLB.push<TemplateSpecializationTypeLoc>(Result); 2218 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 2219 SpecTL.setTemplateNameLoc(TemplateLoc); 2220 SpecTL.setLAngleLoc(LAngleLoc); 2221 SpecTL.setRAngleLoc(RAngleLoc); 2222 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i) 2223 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 2224 2225 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a 2226 // constructor or destructor name (in such a case, the scope specifier 2227 // will be attached to the enclosing Decl or Expr node). 2228 if (SS.isNotEmpty() && !IsCtorOrDtorName) { 2229 // Create an elaborated-type-specifier containing the nested-name-specifier. 2230 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result); 2231 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result); 2232 ElabTL.setElaboratedKeywordLoc(SourceLocation()); 2233 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context)); 2234 } 2235 2236 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result)); 2237 } 2238 2239 TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK, 2240 TypeSpecifierType TagSpec, 2241 SourceLocation TagLoc, 2242 CXXScopeSpec &SS, 2243 SourceLocation TemplateKWLoc, 2244 TemplateTy TemplateD, 2245 SourceLocation TemplateLoc, 2246 SourceLocation LAngleLoc, 2247 ASTTemplateArgsPtr TemplateArgsIn, 2248 SourceLocation RAngleLoc) { 2249 TemplateName Template = TemplateD.get(); 2250 2251 // Translate the parser's template argument list in our AST format. 2252 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 2253 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 2254 2255 // Determine the tag kind 2256 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 2257 ElaboratedTypeKeyword Keyword 2258 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind); 2259 2260 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) { 2261 QualType T = Context.getDependentTemplateSpecializationType(Keyword, 2262 DTN->getQualifier(), 2263 DTN->getIdentifier(), 2264 TemplateArgs); 2265 2266 // Build type-source information. 2267 TypeLocBuilder TLB; 2268 DependentTemplateSpecializationTypeLoc SpecTL 2269 = TLB.push<DependentTemplateSpecializationTypeLoc>(T); 2270 SpecTL.setElaboratedKeywordLoc(TagLoc); 2271 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 2272 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 2273 SpecTL.setTemplateNameLoc(TemplateLoc); 2274 SpecTL.setLAngleLoc(LAngleLoc); 2275 SpecTL.setRAngleLoc(RAngleLoc); 2276 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I) 2277 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 2278 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T)); 2279 } 2280 2281 if (TypeAliasTemplateDecl *TAT = 2282 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) { 2283 // C++0x [dcl.type.elab]p2: 2284 // If the identifier resolves to a typedef-name or the simple-template-id 2285 // resolves to an alias template specialization, the 2286 // elaborated-type-specifier is ill-formed. 2287 Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4; 2288 Diag(TAT->getLocation(), diag::note_declared_at); 2289 } 2290 2291 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); 2292 if (Result.isNull()) 2293 return TypeResult(true); 2294 2295 // Check the tag kind 2296 if (const RecordType *RT = Result->getAs<RecordType>()) { 2297 RecordDecl *D = RT->getDecl(); 2298 2299 IdentifierInfo *Id = D->getIdentifier(); 2300 assert(Id && "templated class must have an identifier"); 2301 2302 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition, 2303 TagLoc, *Id)) { 2304 Diag(TagLoc, diag::err_use_with_wrong_tag) 2305 << Result 2306 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName()); 2307 Diag(D->getLocation(), diag::note_previous_use); 2308 } 2309 } 2310 2311 // Provide source-location information for the template specialization. 2312 TypeLocBuilder TLB; 2313 TemplateSpecializationTypeLoc SpecTL 2314 = TLB.push<TemplateSpecializationTypeLoc>(Result); 2315 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 2316 SpecTL.setTemplateNameLoc(TemplateLoc); 2317 SpecTL.setLAngleLoc(LAngleLoc); 2318 SpecTL.setRAngleLoc(RAngleLoc); 2319 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i) 2320 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 2321 2322 // Construct an elaborated type containing the nested-name-specifier (if any) 2323 // and tag keyword. 2324 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result); 2325 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result); 2326 ElabTL.setElaboratedKeywordLoc(TagLoc); 2327 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context)); 2328 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result)); 2329 } 2330 2331 static bool CheckTemplatePartialSpecializationArgs( 2332 Sema &S, SourceLocation NameLoc, TemplateParameterList *TemplateParams, 2333 unsigned ExplicitArgs, SmallVectorImpl<TemplateArgument> &TemplateArgs); 2334 2335 static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized, 2336 NamedDecl *PrevDecl, 2337 SourceLocation Loc, 2338 bool IsPartialSpecialization); 2339 2340 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D); 2341 2342 static bool isTemplateArgumentTemplateParameter( 2343 const TemplateArgument &Arg, unsigned Depth, unsigned Index) { 2344 switch (Arg.getKind()) { 2345 case TemplateArgument::Null: 2346 case TemplateArgument::NullPtr: 2347 case TemplateArgument::Integral: 2348 case TemplateArgument::Declaration: 2349 case TemplateArgument::Pack: 2350 case TemplateArgument::TemplateExpansion: 2351 return false; 2352 2353 case TemplateArgument::Type: { 2354 QualType Type = Arg.getAsType(); 2355 const TemplateTypeParmType *TPT = 2356 Arg.getAsType()->getAs<TemplateTypeParmType>(); 2357 return TPT && !Type.hasQualifiers() && 2358 TPT->getDepth() == Depth && TPT->getIndex() == Index; 2359 } 2360 2361 case TemplateArgument::Expression: { 2362 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr()); 2363 if (!DRE || !DRE->getDecl()) 2364 return false; 2365 const NonTypeTemplateParmDecl *NTTP = 2366 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); 2367 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index; 2368 } 2369 2370 case TemplateArgument::Template: 2371 const TemplateTemplateParmDecl *TTP = 2372 dyn_cast_or_null<TemplateTemplateParmDecl>( 2373 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl()); 2374 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index; 2375 } 2376 llvm_unreachable("unexpected kind of template argument"); 2377 } 2378 2379 static bool isSameAsPrimaryTemplate(TemplateParameterList *Params, 2380 ArrayRef<TemplateArgument> Args) { 2381 if (Params->size() != Args.size()) 2382 return false; 2383 2384 unsigned Depth = Params->getDepth(); 2385 2386 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 2387 TemplateArgument Arg = Args[I]; 2388 2389 // If the parameter is a pack expansion, the argument must be a pack 2390 // whose only element is a pack expansion. 2391 if (Params->getParam(I)->isParameterPack()) { 2392 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 || 2393 !Arg.pack_begin()->isPackExpansion()) 2394 return false; 2395 Arg = Arg.pack_begin()->getPackExpansionPattern(); 2396 } 2397 2398 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I)) 2399 return false; 2400 } 2401 2402 return true; 2403 } 2404 2405 /// Convert the parser's template argument list representation into our form. 2406 static TemplateArgumentListInfo 2407 makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) { 2408 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc, 2409 TemplateId.RAngleLoc); 2410 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(), 2411 TemplateId.NumArgs); 2412 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs); 2413 return TemplateArgs; 2414 } 2415 2416 DeclResult Sema::ActOnVarTemplateSpecialization( 2417 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc, 2418 TemplateParameterList *TemplateParams, StorageClass SC, 2419 bool IsPartialSpecialization) { 2420 // D must be variable template id. 2421 assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId && 2422 "Variable template specialization is declared with a template it."); 2423 2424 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 2425 TemplateArgumentListInfo TemplateArgs = 2426 makeTemplateArgumentListInfo(*this, *TemplateId); 2427 SourceLocation TemplateNameLoc = D.getIdentifierLoc(); 2428 SourceLocation LAngleLoc = TemplateId->LAngleLoc; 2429 SourceLocation RAngleLoc = TemplateId->RAngleLoc; 2430 2431 TemplateName Name = TemplateId->Template.get(); 2432 2433 // The template-id must name a variable template. 2434 VarTemplateDecl *VarTemplate = 2435 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl()); 2436 if (!VarTemplate) { 2437 NamedDecl *FnTemplate; 2438 if (auto *OTS = Name.getAsOverloadedTemplate()) 2439 FnTemplate = *OTS->begin(); 2440 else 2441 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 2442 if (FnTemplate) 2443 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method) 2444 << FnTemplate->getDeclName(); 2445 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template) 2446 << IsPartialSpecialization; 2447 } 2448 2449 // Check for unexpanded parameter packs in any of the template arguments. 2450 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 2451 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I], 2452 UPPC_PartialSpecialization)) 2453 return true; 2454 2455 // Check that the template argument list is well-formed for this 2456 // template. 2457 SmallVector<TemplateArgument, 4> Converted; 2458 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs, 2459 false, Converted)) 2460 return true; 2461 2462 // Check that the type of this variable template specialization 2463 // matches the expected type. 2464 TypeSourceInfo *ExpectedDI; 2465 { 2466 // Do substitution on the type of the declaration 2467 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack, 2468 Converted.data(), Converted.size()); 2469 InstantiatingTemplate Inst(*this, TemplateKWLoc, VarTemplate); 2470 if (Inst.isInvalid()) 2471 return true; 2472 VarDecl *Templated = VarTemplate->getTemplatedDecl(); 2473 ExpectedDI = 2474 SubstType(Templated->getTypeSourceInfo(), 2475 MultiLevelTemplateArgumentList(TemplateArgList), 2476 Templated->getTypeSpecStartLoc(), Templated->getDeclName()); 2477 } 2478 if (!ExpectedDI) 2479 return true; 2480 2481 // Find the variable template (partial) specialization declaration that 2482 // corresponds to these arguments. 2483 if (IsPartialSpecialization) { 2484 if (CheckTemplatePartialSpecializationArgs( 2485 *this, TemplateNameLoc, VarTemplate->getTemplateParameters(), 2486 TemplateArgs.size(), Converted)) 2487 return true; 2488 2489 bool InstantiationDependent; 2490 if (!Name.isDependent() && 2491 !TemplateSpecializationType::anyDependentTemplateArguments( 2492 TemplateArgs.getArgumentArray(), TemplateArgs.size(), 2493 InstantiationDependent)) { 2494 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) 2495 << VarTemplate->getDeclName(); 2496 IsPartialSpecialization = false; 2497 } 2498 2499 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(), 2500 Converted)) { 2501 // C++ [temp.class.spec]p9b3: 2502 // 2503 // -- The argument list of the specialization shall not be identical 2504 // to the implicit argument list of the primary template. 2505 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 2506 << /*variable template*/ 1 2507 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord()) 2508 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); 2509 // FIXME: Recover from this by treating the declaration as a redeclaration 2510 // of the primary template. 2511 return true; 2512 } 2513 } 2514 2515 void *InsertPos = nullptr; 2516 VarTemplateSpecializationDecl *PrevDecl = nullptr; 2517 2518 if (IsPartialSpecialization) 2519 // FIXME: Template parameter list matters too 2520 PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos); 2521 else 2522 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos); 2523 2524 VarTemplateSpecializationDecl *Specialization = nullptr; 2525 2526 // Check whether we can declare a variable template specialization in 2527 // the current scope. 2528 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl, 2529 TemplateNameLoc, 2530 IsPartialSpecialization)) 2531 return true; 2532 2533 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) { 2534 // Since the only prior variable template specialization with these 2535 // arguments was referenced but not declared, reuse that 2536 // declaration node as our own, updating its source location and 2537 // the list of outer template parameters to reflect our new declaration. 2538 Specialization = PrevDecl; 2539 Specialization->setLocation(TemplateNameLoc); 2540 PrevDecl = nullptr; 2541 } else if (IsPartialSpecialization) { 2542 // Create a new class template partial specialization declaration node. 2543 VarTemplatePartialSpecializationDecl *PrevPartial = 2544 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl); 2545 VarTemplatePartialSpecializationDecl *Partial = 2546 VarTemplatePartialSpecializationDecl::Create( 2547 Context, VarTemplate->getDeclContext(), TemplateKWLoc, 2548 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC, 2549 Converted.data(), Converted.size(), TemplateArgs); 2550 2551 if (!PrevPartial) 2552 VarTemplate->AddPartialSpecialization(Partial, InsertPos); 2553 Specialization = Partial; 2554 2555 // If we are providing an explicit specialization of a member variable 2556 // template specialization, make a note of that. 2557 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 2558 PrevPartial->setMemberSpecialization(); 2559 2560 // Check that all of the template parameters of the variable template 2561 // partial specialization are deducible from the template 2562 // arguments. If not, this variable template partial specialization 2563 // will never be used. 2564 llvm::SmallBitVector DeducibleParams(TemplateParams->size()); 2565 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 2566 TemplateParams->getDepth(), DeducibleParams); 2567 2568 if (!DeducibleParams.all()) { 2569 unsigned NumNonDeducible = 2570 DeducibleParams.size() - DeducibleParams.count(); 2571 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 2572 << /*variable template*/ 1 << (NumNonDeducible > 1) 2573 << SourceRange(TemplateNameLoc, RAngleLoc); 2574 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 2575 if (!DeducibleParams[I]) { 2576 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 2577 if (Param->getDeclName()) 2578 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter) 2579 << Param->getDeclName(); 2580 else 2581 Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter) 2582 << "(anonymous)"; 2583 } 2584 } 2585 } 2586 } else { 2587 // Create a new class template specialization declaration node for 2588 // this explicit specialization or friend declaration. 2589 Specialization = VarTemplateSpecializationDecl::Create( 2590 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc, 2591 VarTemplate, DI->getType(), DI, SC, Converted.data(), Converted.size()); 2592 Specialization->setTemplateArgsInfo(TemplateArgs); 2593 2594 if (!PrevDecl) 2595 VarTemplate->AddSpecialization(Specialization, InsertPos); 2596 } 2597 2598 // C++ [temp.expl.spec]p6: 2599 // If a template, a member template or the member of a class template is 2600 // explicitly specialized then that specialization shall be declared 2601 // before the first use of that specialization that would cause an implicit 2602 // instantiation to take place, in every translation unit in which such a 2603 // use occurs; no diagnostic is required. 2604 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 2605 bool Okay = false; 2606 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) { 2607 // Is there any previous explicit specialization declaration? 2608 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 2609 Okay = true; 2610 break; 2611 } 2612 } 2613 2614 if (!Okay) { 2615 SourceRange Range(TemplateNameLoc, RAngleLoc); 2616 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 2617 << Name << Range; 2618 2619 Diag(PrevDecl->getPointOfInstantiation(), 2620 diag::note_instantiation_required_here) 2621 << (PrevDecl->getTemplateSpecializationKind() != 2622 TSK_ImplicitInstantiation); 2623 return true; 2624 } 2625 } 2626 2627 Specialization->setTemplateKeywordLoc(TemplateKWLoc); 2628 Specialization->setLexicalDeclContext(CurContext); 2629 2630 // Add the specialization into its lexical context, so that it can 2631 // be seen when iterating through the list of declarations in that 2632 // context. However, specializations are not found by name lookup. 2633 CurContext->addDecl(Specialization); 2634 2635 // Note that this is an explicit specialization. 2636 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 2637 2638 if (PrevDecl) { 2639 // Check that this isn't a redefinition of this specialization, 2640 // merging with previous declarations. 2641 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName, 2642 ForRedeclaration); 2643 PrevSpec.addDecl(PrevDecl); 2644 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec)); 2645 } else if (Specialization->isStaticDataMember() && 2646 Specialization->isOutOfLine()) { 2647 Specialization->setAccess(VarTemplate->getAccess()); 2648 } 2649 2650 // Link instantiations of static data members back to the template from 2651 // which they were instantiated. 2652 if (Specialization->isStaticDataMember()) 2653 Specialization->setInstantiationOfStaticDataMember( 2654 VarTemplate->getTemplatedDecl(), 2655 Specialization->getSpecializationKind()); 2656 2657 return Specialization; 2658 } 2659 2660 namespace { 2661 /// \brief A partial specialization whose template arguments have matched 2662 /// a given template-id. 2663 struct PartialSpecMatchResult { 2664 VarTemplatePartialSpecializationDecl *Partial; 2665 TemplateArgumentList *Args; 2666 }; 2667 } 2668 2669 DeclResult 2670 Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc, 2671 SourceLocation TemplateNameLoc, 2672 const TemplateArgumentListInfo &TemplateArgs) { 2673 assert(Template && "A variable template id without template?"); 2674 2675 // Check that the template argument list is well-formed for this template. 2676 SmallVector<TemplateArgument, 4> Converted; 2677 if (CheckTemplateArgumentList( 2678 Template, TemplateNameLoc, 2679 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false, 2680 Converted)) 2681 return true; 2682 2683 // Find the variable template specialization declaration that 2684 // corresponds to these arguments. 2685 void *InsertPos = nullptr; 2686 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization( 2687 Converted, InsertPos)) 2688 // If we already have a variable template specialization, return it. 2689 return Spec; 2690 2691 // This is the first time we have referenced this variable template 2692 // specialization. Create the canonical declaration and add it to 2693 // the set of specializations, based on the closest partial specialization 2694 // that it represents. That is, 2695 VarDecl *InstantiationPattern = Template->getTemplatedDecl(); 2696 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack, 2697 Converted.data(), Converted.size()); 2698 TemplateArgumentList *InstantiationArgs = &TemplateArgList; 2699 bool AmbiguousPartialSpec = false; 2700 typedef PartialSpecMatchResult MatchResult; 2701 SmallVector<MatchResult, 4> Matched; 2702 SourceLocation PointOfInstantiation = TemplateNameLoc; 2703 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation); 2704 2705 // 1. Attempt to find the closest partial specialization that this 2706 // specializes, if any. 2707 // If any of the template arguments is dependent, then this is probably 2708 // a placeholder for an incomplete declarative context; which must be 2709 // complete by instantiation time. Thus, do not search through the partial 2710 // specializations yet. 2711 // TODO: Unify with InstantiateClassTemplateSpecialization()? 2712 // Perhaps better after unification of DeduceTemplateArguments() and 2713 // getMoreSpecializedPartialSpecialization(). 2714 bool InstantiationDependent = false; 2715 if (!TemplateSpecializationType::anyDependentTemplateArguments( 2716 TemplateArgs, InstantiationDependent)) { 2717 2718 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs; 2719 Template->getPartialSpecializations(PartialSpecs); 2720 2721 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) { 2722 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I]; 2723 TemplateDeductionInfo Info(FailedCandidates.getLocation()); 2724 2725 if (TemplateDeductionResult Result = 2726 DeduceTemplateArguments(Partial, TemplateArgList, Info)) { 2727 // Store the failed-deduction information for use in diagnostics, later. 2728 // TODO: Actually use the failed-deduction info? 2729 FailedCandidates.addCandidate() 2730 .set(Partial, MakeDeductionFailureInfo(Context, Result, Info)); 2731 (void)Result; 2732 } else { 2733 Matched.push_back(PartialSpecMatchResult()); 2734 Matched.back().Partial = Partial; 2735 Matched.back().Args = Info.take(); 2736 } 2737 } 2738 2739 if (Matched.size() >= 1) { 2740 SmallVector<MatchResult, 4>::iterator Best = Matched.begin(); 2741 if (Matched.size() == 1) { 2742 // -- If exactly one matching specialization is found, the 2743 // instantiation is generated from that specialization. 2744 // We don't need to do anything for this. 2745 } else { 2746 // -- If more than one matching specialization is found, the 2747 // partial order rules (14.5.4.2) are used to determine 2748 // whether one of the specializations is more specialized 2749 // than the others. If none of the specializations is more 2750 // specialized than all of the other matching 2751 // specializations, then the use of the variable template is 2752 // ambiguous and the program is ill-formed. 2753 for (SmallVector<MatchResult, 4>::iterator P = Best + 1, 2754 PEnd = Matched.end(); 2755 P != PEnd; ++P) { 2756 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial, 2757 PointOfInstantiation) == 2758 P->Partial) 2759 Best = P; 2760 } 2761 2762 // Determine if the best partial specialization is more specialized than 2763 // the others. 2764 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(), 2765 PEnd = Matched.end(); 2766 P != PEnd; ++P) { 2767 if (P != Best && getMoreSpecializedPartialSpecialization( 2768 P->Partial, Best->Partial, 2769 PointOfInstantiation) != Best->Partial) { 2770 AmbiguousPartialSpec = true; 2771 break; 2772 } 2773 } 2774 } 2775 2776 // Instantiate using the best variable template partial specialization. 2777 InstantiationPattern = Best->Partial; 2778 InstantiationArgs = Best->Args; 2779 } else { 2780 // -- If no match is found, the instantiation is generated 2781 // from the primary template. 2782 // InstantiationPattern = Template->getTemplatedDecl(); 2783 } 2784 } 2785 2786 // 2. Create the canonical declaration. 2787 // Note that we do not instantiate the variable just yet, since 2788 // instantiation is handled in DoMarkVarDeclReferenced(). 2789 // FIXME: LateAttrs et al.? 2790 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation( 2791 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs, 2792 Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/); 2793 if (!Decl) 2794 return true; 2795 2796 if (AmbiguousPartialSpec) { 2797 // Partial ordering did not produce a clear winner. Complain. 2798 Decl->setInvalidDecl(); 2799 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous) 2800 << Decl; 2801 2802 // Print the matching partial specializations. 2803 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(), 2804 PEnd = Matched.end(); 2805 P != PEnd; ++P) 2806 Diag(P->Partial->getLocation(), diag::note_partial_spec_match) 2807 << getTemplateArgumentBindingsText( 2808 P->Partial->getTemplateParameters(), *P->Args); 2809 return true; 2810 } 2811 2812 if (VarTemplatePartialSpecializationDecl *D = 2813 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern)) 2814 Decl->setInstantiationOf(D, InstantiationArgs); 2815 2816 assert(Decl && "No variable template specialization?"); 2817 return Decl; 2818 } 2819 2820 ExprResult 2821 Sema::CheckVarTemplateId(const CXXScopeSpec &SS, 2822 const DeclarationNameInfo &NameInfo, 2823 VarTemplateDecl *Template, SourceLocation TemplateLoc, 2824 const TemplateArgumentListInfo *TemplateArgs) { 2825 2826 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(), 2827 *TemplateArgs); 2828 if (Decl.isInvalid()) 2829 return ExprError(); 2830 2831 VarDecl *Var = cast<VarDecl>(Decl.get()); 2832 if (!Var->getTemplateSpecializationKind()) 2833 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation, 2834 NameInfo.getLoc()); 2835 2836 // Build an ordinary singleton decl ref. 2837 return BuildDeclarationNameExpr(SS, NameInfo, Var, 2838 /*FoundD=*/nullptr, TemplateArgs); 2839 } 2840 2841 ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, 2842 SourceLocation TemplateKWLoc, 2843 LookupResult &R, 2844 bool RequiresADL, 2845 const TemplateArgumentListInfo *TemplateArgs) { 2846 // FIXME: Can we do any checking at this point? I guess we could check the 2847 // template arguments that we have against the template name, if the template 2848 // name refers to a single template. That's not a terribly common case, 2849 // though. 2850 // foo<int> could identify a single function unambiguously 2851 // This approach does NOT work, since f<int>(1); 2852 // gets resolved prior to resorting to overload resolution 2853 // i.e., template<class T> void f(double); 2854 // vs template<class T, class U> void f(U); 2855 2856 // These should be filtered out by our callers. 2857 assert(!R.empty() && "empty lookup results when building templateid"); 2858 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid"); 2859 2860 // In C++1y, check variable template ids. 2861 bool InstantiationDependent; 2862 if (R.getAsSingle<VarTemplateDecl>() && 2863 !TemplateSpecializationType::anyDependentTemplateArguments( 2864 *TemplateArgs, InstantiationDependent)) { 2865 return CheckVarTemplateId(SS, R.getLookupNameInfo(), 2866 R.getAsSingle<VarTemplateDecl>(), 2867 TemplateKWLoc, TemplateArgs); 2868 } 2869 2870 // We don't want lookup warnings at this point. 2871 R.suppressDiagnostics(); 2872 2873 UnresolvedLookupExpr *ULE 2874 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), 2875 SS.getWithLocInContext(Context), 2876 TemplateKWLoc, 2877 R.getLookupNameInfo(), 2878 RequiresADL, TemplateArgs, 2879 R.begin(), R.end()); 2880 2881 return ULE; 2882 } 2883 2884 // We actually only call this from template instantiation. 2885 ExprResult 2886 Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, 2887 SourceLocation TemplateKWLoc, 2888 const DeclarationNameInfo &NameInfo, 2889 const TemplateArgumentListInfo *TemplateArgs) { 2890 2891 assert(TemplateArgs || TemplateKWLoc.isValid()); 2892 DeclContext *DC; 2893 if (!(DC = computeDeclContext(SS, false)) || 2894 DC->isDependentContext() || 2895 RequireCompleteDeclContext(SS, DC)) 2896 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs); 2897 2898 bool MemberOfUnknownSpecialization; 2899 LookupResult R(*this, NameInfo, LookupOrdinaryName); 2900 LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false, 2901 MemberOfUnknownSpecialization); 2902 2903 if (R.isAmbiguous()) 2904 return ExprError(); 2905 2906 if (R.empty()) { 2907 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template) 2908 << NameInfo.getName() << SS.getRange(); 2909 return ExprError(); 2910 } 2911 2912 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) { 2913 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template) 2914 << SS.getScopeRep() 2915 << NameInfo.getName().getAsString() << SS.getRange(); 2916 Diag(Temp->getLocation(), diag::note_referenced_class_template); 2917 return ExprError(); 2918 } 2919 2920 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs); 2921 } 2922 2923 /// \brief Form a dependent template name. 2924 /// 2925 /// This action forms a dependent template name given the template 2926 /// name and its (presumably dependent) scope specifier. For 2927 /// example, given "MetaFun::template apply", the scope specifier \p 2928 /// SS will be "MetaFun::", \p TemplateKWLoc contains the location 2929 /// of the "template" keyword, and "apply" is the \p Name. 2930 TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S, 2931 CXXScopeSpec &SS, 2932 SourceLocation TemplateKWLoc, 2933 UnqualifiedId &Name, 2934 ParsedType ObjectType, 2935 bool EnteringContext, 2936 TemplateTy &Result) { 2937 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent()) 2938 Diag(TemplateKWLoc, 2939 getLangOpts().CPlusPlus11 ? 2940 diag::warn_cxx98_compat_template_outside_of_template : 2941 diag::ext_template_outside_of_template) 2942 << FixItHint::CreateRemoval(TemplateKWLoc); 2943 2944 DeclContext *LookupCtx = nullptr; 2945 if (SS.isSet()) 2946 LookupCtx = computeDeclContext(SS, EnteringContext); 2947 if (!LookupCtx && ObjectType) 2948 LookupCtx = computeDeclContext(ObjectType.get()); 2949 if (LookupCtx) { 2950 // C++0x [temp.names]p5: 2951 // If a name prefixed by the keyword template is not the name of 2952 // a template, the program is ill-formed. [Note: the keyword 2953 // template may not be applied to non-template members of class 2954 // templates. -end note ] [ Note: as is the case with the 2955 // typename prefix, the template prefix is allowed in cases 2956 // where it is not strictly necessary; i.e., when the 2957 // nested-name-specifier or the expression on the left of the -> 2958 // or . is not dependent on a template-parameter, or the use 2959 // does not appear in the scope of a template. -end note] 2960 // 2961 // Note: C++03 was more strict here, because it banned the use of 2962 // the "template" keyword prior to a template-name that was not a 2963 // dependent name. C++ DR468 relaxed this requirement (the 2964 // "template" keyword is now permitted). We follow the C++0x 2965 // rules, even in C++03 mode with a warning, retroactively applying the DR. 2966 bool MemberOfUnknownSpecialization; 2967 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name, 2968 ObjectType, EnteringContext, Result, 2969 MemberOfUnknownSpecialization); 2970 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() && 2971 isa<CXXRecordDecl>(LookupCtx) && 2972 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || 2973 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) { 2974 // This is a dependent template. Handle it below. 2975 } else if (TNK == TNK_Non_template) { 2976 Diag(Name.getLocStart(), 2977 diag::err_template_kw_refers_to_non_template) 2978 << GetNameFromUnqualifiedId(Name).getName() 2979 << Name.getSourceRange() 2980 << TemplateKWLoc; 2981 return TNK_Non_template; 2982 } else { 2983 // We found something; return it. 2984 return TNK; 2985 } 2986 } 2987 2988 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 2989 2990 switch (Name.getKind()) { 2991 case UnqualifiedId::IK_Identifier: 2992 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 2993 Name.Identifier)); 2994 return TNK_Dependent_template_name; 2995 2996 case UnqualifiedId::IK_OperatorFunctionId: 2997 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 2998 Name.OperatorFunctionId.Operator)); 2999 return TNK_Function_template; 3000 3001 case UnqualifiedId::IK_LiteralOperatorId: 3002 llvm_unreachable("literal operator id cannot have a dependent scope"); 3003 3004 default: 3005 break; 3006 } 3007 3008 Diag(Name.getLocStart(), 3009 diag::err_template_kw_refers_to_non_template) 3010 << GetNameFromUnqualifiedId(Name).getName() 3011 << Name.getSourceRange() 3012 << TemplateKWLoc; 3013 return TNK_Non_template; 3014 } 3015 3016 bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, 3017 TemplateArgumentLoc &AL, 3018 SmallVectorImpl<TemplateArgument> &Converted) { 3019 const TemplateArgument &Arg = AL.getArgument(); 3020 QualType ArgType; 3021 TypeSourceInfo *TSI = nullptr; 3022 3023 // Check template type parameter. 3024 switch(Arg.getKind()) { 3025 case TemplateArgument::Type: 3026 // C++ [temp.arg.type]p1: 3027 // A template-argument for a template-parameter which is a 3028 // type shall be a type-id. 3029 ArgType = Arg.getAsType(); 3030 TSI = AL.getTypeSourceInfo(); 3031 break; 3032 case TemplateArgument::Template: { 3033 // We have a template type parameter but the template argument 3034 // is a template without any arguments. 3035 SourceRange SR = AL.getSourceRange(); 3036 TemplateName Name = Arg.getAsTemplate(); 3037 Diag(SR.getBegin(), diag::err_template_missing_args) 3038 << Name << SR; 3039 if (TemplateDecl *Decl = Name.getAsTemplateDecl()) 3040 Diag(Decl->getLocation(), diag::note_template_decl_here); 3041 3042 return true; 3043 } 3044 case TemplateArgument::Expression: { 3045 // We have a template type parameter but the template argument is an 3046 // expression; see if maybe it is missing the "typename" keyword. 3047 CXXScopeSpec SS; 3048 DeclarationNameInfo NameInfo; 3049 3050 if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) { 3051 SS.Adopt(ArgExpr->getQualifierLoc()); 3052 NameInfo = ArgExpr->getNameInfo(); 3053 } else if (DependentScopeDeclRefExpr *ArgExpr = 3054 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) { 3055 SS.Adopt(ArgExpr->getQualifierLoc()); 3056 NameInfo = ArgExpr->getNameInfo(); 3057 } else if (CXXDependentScopeMemberExpr *ArgExpr = 3058 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) { 3059 if (ArgExpr->isImplicitAccess()) { 3060 SS.Adopt(ArgExpr->getQualifierLoc()); 3061 NameInfo = ArgExpr->getMemberNameInfo(); 3062 } 3063 } 3064 3065 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) { 3066 LookupResult Result(*this, NameInfo, LookupOrdinaryName); 3067 LookupParsedName(Result, CurScope, &SS); 3068 3069 if (Result.getAsSingle<TypeDecl>() || 3070 Result.getResultKind() == 3071 LookupResult::NotFoundInCurrentInstantiation) { 3072 // Suggest that the user add 'typename' before the NNS. 3073 SourceLocation Loc = AL.getSourceRange().getBegin(); 3074 Diag(Loc, getLangOpts().MSVCCompat 3075 ? diag::ext_ms_template_type_arg_missing_typename 3076 : diag::err_template_arg_must_be_type_suggest) 3077 << FixItHint::CreateInsertion(Loc, "typename "); 3078 Diag(Param->getLocation(), diag::note_template_param_here); 3079 3080 // Recover by synthesizing a type using the location information that we 3081 // already have. 3082 ArgType = 3083 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II); 3084 TypeLocBuilder TLB; 3085 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType); 3086 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/)); 3087 TL.setQualifierLoc(SS.getWithLocInContext(Context)); 3088 TL.setNameLoc(NameInfo.getLoc()); 3089 TSI = TLB.getTypeSourceInfo(Context, ArgType); 3090 3091 // Overwrite our input TemplateArgumentLoc so that we can recover 3092 // properly. 3093 AL = TemplateArgumentLoc(TemplateArgument(ArgType), 3094 TemplateArgumentLocInfo(TSI)); 3095 3096 break; 3097 } 3098 } 3099 // fallthrough 3100 } 3101 default: { 3102 // We have a template type parameter but the template argument 3103 // is not a type. 3104 SourceRange SR = AL.getSourceRange(); 3105 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; 3106 Diag(Param->getLocation(), diag::note_template_param_here); 3107 3108 return true; 3109 } 3110 } 3111 3112 if (CheckTemplateArgument(Param, TSI)) 3113 return true; 3114 3115 // Add the converted template type argument. 3116 ArgType = Context.getCanonicalType(ArgType); 3117 3118 // Objective-C ARC: 3119 // If an explicitly-specified template argument type is a lifetime type 3120 // with no lifetime qualifier, the __strong lifetime qualifier is inferred. 3121 if (getLangOpts().ObjCAutoRefCount && 3122 ArgType->isObjCLifetimeType() && 3123 !ArgType.getObjCLifetime()) { 3124 Qualifiers Qs; 3125 Qs.setObjCLifetime(Qualifiers::OCL_Strong); 3126 ArgType = Context.getQualifiedType(ArgType, Qs); 3127 } 3128 3129 Converted.push_back(TemplateArgument(ArgType)); 3130 return false; 3131 } 3132 3133 /// \brief Substitute template arguments into the default template argument for 3134 /// the given template type parameter. 3135 /// 3136 /// \param SemaRef the semantic analysis object for which we are performing 3137 /// the substitution. 3138 /// 3139 /// \param Template the template that we are synthesizing template arguments 3140 /// for. 3141 /// 3142 /// \param TemplateLoc the location of the template name that started the 3143 /// template-id we are checking. 3144 /// 3145 /// \param RAngleLoc the location of the right angle bracket ('>') that 3146 /// terminates the template-id. 3147 /// 3148 /// \param Param the template template parameter whose default we are 3149 /// substituting into. 3150 /// 3151 /// \param Converted the list of template arguments provided for template 3152 /// parameters that precede \p Param in the template parameter list. 3153 /// \returns the substituted template argument, or NULL if an error occurred. 3154 static TypeSourceInfo * 3155 SubstDefaultTemplateArgument(Sema &SemaRef, 3156 TemplateDecl *Template, 3157 SourceLocation TemplateLoc, 3158 SourceLocation RAngleLoc, 3159 TemplateTypeParmDecl *Param, 3160 SmallVectorImpl<TemplateArgument> &Converted) { 3161 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo(); 3162 3163 // If the argument type is dependent, instantiate it now based 3164 // on the previously-computed template arguments. 3165 if (ArgType->getType()->isDependentType()) { 3166 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 3167 Template, Converted, 3168 SourceRange(TemplateLoc, RAngleLoc)); 3169 if (Inst.isInvalid()) 3170 return nullptr; 3171 3172 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 3173 Converted.data(), Converted.size()); 3174 3175 // Only substitute for the innermost template argument list. 3176 MultiLevelTemplateArgumentList TemplateArgLists; 3177 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); 3178 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) 3179 TemplateArgLists.addOuterTemplateArguments(None); 3180 3181 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); 3182 ArgType = 3183 SemaRef.SubstType(ArgType, TemplateArgLists, 3184 Param->getDefaultArgumentLoc(), Param->getDeclName()); 3185 } 3186 3187 return ArgType; 3188 } 3189 3190 /// \brief Substitute template arguments into the default template argument for 3191 /// the given non-type template parameter. 3192 /// 3193 /// \param SemaRef the semantic analysis object for which we are performing 3194 /// the substitution. 3195 /// 3196 /// \param Template the template that we are synthesizing template arguments 3197 /// for. 3198 /// 3199 /// \param TemplateLoc the location of the template name that started the 3200 /// template-id we are checking. 3201 /// 3202 /// \param RAngleLoc the location of the right angle bracket ('>') that 3203 /// terminates the template-id. 3204 /// 3205 /// \param Param the non-type template parameter whose default we are 3206 /// substituting into. 3207 /// 3208 /// \param Converted the list of template arguments provided for template 3209 /// parameters that precede \p Param in the template parameter list. 3210 /// 3211 /// \returns the substituted template argument, or NULL if an error occurred. 3212 static ExprResult 3213 SubstDefaultTemplateArgument(Sema &SemaRef, 3214 TemplateDecl *Template, 3215 SourceLocation TemplateLoc, 3216 SourceLocation RAngleLoc, 3217 NonTypeTemplateParmDecl *Param, 3218 SmallVectorImpl<TemplateArgument> &Converted) { 3219 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 3220 Template, Converted, 3221 SourceRange(TemplateLoc, RAngleLoc)); 3222 if (Inst.isInvalid()) 3223 return ExprError(); 3224 3225 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 3226 Converted.data(), Converted.size()); 3227 3228 // Only substitute for the innermost template argument list. 3229 MultiLevelTemplateArgumentList TemplateArgLists; 3230 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); 3231 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) 3232 TemplateArgLists.addOuterTemplateArguments(None); 3233 3234 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); 3235 EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated); 3236 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists); 3237 } 3238 3239 /// \brief Substitute template arguments into the default template argument for 3240 /// the given template template parameter. 3241 /// 3242 /// \param SemaRef the semantic analysis object for which we are performing 3243 /// the substitution. 3244 /// 3245 /// \param Template the template that we are synthesizing template arguments 3246 /// for. 3247 /// 3248 /// \param TemplateLoc the location of the template name that started the 3249 /// template-id we are checking. 3250 /// 3251 /// \param RAngleLoc the location of the right angle bracket ('>') that 3252 /// terminates the template-id. 3253 /// 3254 /// \param Param the template template parameter whose default we are 3255 /// substituting into. 3256 /// 3257 /// \param Converted the list of template arguments provided for template 3258 /// parameters that precede \p Param in the template parameter list. 3259 /// 3260 /// \param QualifierLoc Will be set to the nested-name-specifier (with 3261 /// source-location information) that precedes the template name. 3262 /// 3263 /// \returns the substituted template argument, or NULL if an error occurred. 3264 static TemplateName 3265 SubstDefaultTemplateArgument(Sema &SemaRef, 3266 TemplateDecl *Template, 3267 SourceLocation TemplateLoc, 3268 SourceLocation RAngleLoc, 3269 TemplateTemplateParmDecl *Param, 3270 SmallVectorImpl<TemplateArgument> &Converted, 3271 NestedNameSpecifierLoc &QualifierLoc) { 3272 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted, 3273 SourceRange(TemplateLoc, RAngleLoc)); 3274 if (Inst.isInvalid()) 3275 return TemplateName(); 3276 3277 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 3278 Converted.data(), Converted.size()); 3279 3280 // Only substitute for the innermost template argument list. 3281 MultiLevelTemplateArgumentList TemplateArgLists; 3282 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); 3283 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) 3284 TemplateArgLists.addOuterTemplateArguments(None); 3285 3286 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); 3287 // Substitute into the nested-name-specifier first, 3288 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc(); 3289 if (QualifierLoc) { 3290 QualifierLoc = 3291 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists); 3292 if (!QualifierLoc) 3293 return TemplateName(); 3294 } 3295 3296 return SemaRef.SubstTemplateName( 3297 QualifierLoc, 3298 Param->getDefaultArgument().getArgument().getAsTemplate(), 3299 Param->getDefaultArgument().getTemplateNameLoc(), 3300 TemplateArgLists); 3301 } 3302 3303 /// \brief If the given template parameter has a default template 3304 /// argument, substitute into that default template argument and 3305 /// return the corresponding template argument. 3306 TemplateArgumentLoc 3307 Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template, 3308 SourceLocation TemplateLoc, 3309 SourceLocation RAngleLoc, 3310 Decl *Param, 3311 SmallVectorImpl<TemplateArgument> 3312 &Converted, 3313 bool &HasDefaultArg) { 3314 HasDefaultArg = false; 3315 3316 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) { 3317 if (!TypeParm->hasDefaultArgument()) 3318 return TemplateArgumentLoc(); 3319 3320 HasDefaultArg = true; 3321 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template, 3322 TemplateLoc, 3323 RAngleLoc, 3324 TypeParm, 3325 Converted); 3326 if (DI) 3327 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI); 3328 3329 return TemplateArgumentLoc(); 3330 } 3331 3332 if (NonTypeTemplateParmDecl *NonTypeParm 3333 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 3334 if (!NonTypeParm->hasDefaultArgument()) 3335 return TemplateArgumentLoc(); 3336 3337 HasDefaultArg = true; 3338 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template, 3339 TemplateLoc, 3340 RAngleLoc, 3341 NonTypeParm, 3342 Converted); 3343 if (Arg.isInvalid()) 3344 return TemplateArgumentLoc(); 3345 3346 Expr *ArgE = Arg.getAs<Expr>(); 3347 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE); 3348 } 3349 3350 TemplateTemplateParmDecl *TempTempParm 3351 = cast<TemplateTemplateParmDecl>(Param); 3352 if (!TempTempParm->hasDefaultArgument()) 3353 return TemplateArgumentLoc(); 3354 3355 HasDefaultArg = true; 3356 NestedNameSpecifierLoc QualifierLoc; 3357 TemplateName TName = SubstDefaultTemplateArgument(*this, Template, 3358 TemplateLoc, 3359 RAngleLoc, 3360 TempTempParm, 3361 Converted, 3362 QualifierLoc); 3363 if (TName.isNull()) 3364 return TemplateArgumentLoc(); 3365 3366 return TemplateArgumentLoc(TemplateArgument(TName), 3367 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(), 3368 TempTempParm->getDefaultArgument().getTemplateNameLoc()); 3369 } 3370 3371 /// \brief Check that the given template argument corresponds to the given 3372 /// template parameter. 3373 /// 3374 /// \param Param The template parameter against which the argument will be 3375 /// checked. 3376 /// 3377 /// \param Arg The template argument, which may be updated due to conversions. 3378 /// 3379 /// \param Template The template in which the template argument resides. 3380 /// 3381 /// \param TemplateLoc The location of the template name for the template 3382 /// whose argument list we're matching. 3383 /// 3384 /// \param RAngleLoc The location of the right angle bracket ('>') that closes 3385 /// the template argument list. 3386 /// 3387 /// \param ArgumentPackIndex The index into the argument pack where this 3388 /// argument will be placed. Only valid if the parameter is a parameter pack. 3389 /// 3390 /// \param Converted The checked, converted argument will be added to the 3391 /// end of this small vector. 3392 /// 3393 /// \param CTAK Describes how we arrived at this particular template argument: 3394 /// explicitly written, deduced, etc. 3395 /// 3396 /// \returns true on error, false otherwise. 3397 bool Sema::CheckTemplateArgument(NamedDecl *Param, 3398 TemplateArgumentLoc &Arg, 3399 NamedDecl *Template, 3400 SourceLocation TemplateLoc, 3401 SourceLocation RAngleLoc, 3402 unsigned ArgumentPackIndex, 3403 SmallVectorImpl<TemplateArgument> &Converted, 3404 CheckTemplateArgumentKind CTAK) { 3405 // Check template type parameters. 3406 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) 3407 return CheckTemplateTypeArgument(TTP, Arg, Converted); 3408 3409 // Check non-type template parameters. 3410 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { 3411 // Do substitution on the type of the non-type template parameter 3412 // with the template arguments we've seen thus far. But if the 3413 // template has a dependent context then we cannot substitute yet. 3414 QualType NTTPType = NTTP->getType(); 3415 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack()) 3416 NTTPType = NTTP->getExpansionType(ArgumentPackIndex); 3417 3418 if (NTTPType->isDependentType() && 3419 !isa<TemplateTemplateParmDecl>(Template) && 3420 !Template->getDeclContext()->isDependentContext()) { 3421 // Do substitution on the type of the non-type template parameter. 3422 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 3423 NTTP, Converted, 3424 SourceRange(TemplateLoc, RAngleLoc)); 3425 if (Inst.isInvalid()) 3426 return true; 3427 3428 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 3429 Converted.data(), Converted.size()); 3430 NTTPType = SubstType(NTTPType, 3431 MultiLevelTemplateArgumentList(TemplateArgs), 3432 NTTP->getLocation(), 3433 NTTP->getDeclName()); 3434 // If that worked, check the non-type template parameter type 3435 // for validity. 3436 if (!NTTPType.isNull()) 3437 NTTPType = CheckNonTypeTemplateParameterType(NTTPType, 3438 NTTP->getLocation()); 3439 if (NTTPType.isNull()) 3440 return true; 3441 } 3442 3443 switch (Arg.getArgument().getKind()) { 3444 case TemplateArgument::Null: 3445 llvm_unreachable("Should never see a NULL template argument here"); 3446 3447 case TemplateArgument::Expression: { 3448 TemplateArgument Result; 3449 ExprResult Res = 3450 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(), 3451 Result, CTAK); 3452 if (Res.isInvalid()) 3453 return true; 3454 3455 // If the resulting expression is new, then use it in place of the 3456 // old expression in the template argument. 3457 if (Res.get() != Arg.getArgument().getAsExpr()) { 3458 TemplateArgument TA(Res.get()); 3459 Arg = TemplateArgumentLoc(TA, Res.get()); 3460 } 3461 3462 Converted.push_back(Result); 3463 break; 3464 } 3465 3466 case TemplateArgument::Declaration: 3467 case TemplateArgument::Integral: 3468 case TemplateArgument::NullPtr: 3469 // We've already checked this template argument, so just copy 3470 // it to the list of converted arguments. 3471 Converted.push_back(Arg.getArgument()); 3472 break; 3473 3474 case TemplateArgument::Template: 3475 case TemplateArgument::TemplateExpansion: 3476 // We were given a template template argument. It may not be ill-formed; 3477 // see below. 3478 if (DependentTemplateName *DTN 3479 = Arg.getArgument().getAsTemplateOrTemplatePattern() 3480 .getAsDependentTemplateName()) { 3481 // We have a template argument such as \c T::template X, which we 3482 // parsed as a template template argument. However, since we now 3483 // know that we need a non-type template argument, convert this 3484 // template name into an expression. 3485 3486 DeclarationNameInfo NameInfo(DTN->getIdentifier(), 3487 Arg.getTemplateNameLoc()); 3488 3489 CXXScopeSpec SS; 3490 SS.Adopt(Arg.getTemplateQualifierLoc()); 3491 // FIXME: the template-template arg was a DependentTemplateName, 3492 // so it was provided with a template keyword. However, its source 3493 // location is not stored in the template argument structure. 3494 SourceLocation TemplateKWLoc; 3495 ExprResult E = DependentScopeDeclRefExpr::Create( 3496 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo, 3497 nullptr); 3498 3499 // If we parsed the template argument as a pack expansion, create a 3500 // pack expansion expression. 3501 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){ 3502 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc()); 3503 if (E.isInvalid()) 3504 return true; 3505 } 3506 3507 TemplateArgument Result; 3508 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result); 3509 if (E.isInvalid()) 3510 return true; 3511 3512 Converted.push_back(Result); 3513 break; 3514 } 3515 3516 // We have a template argument that actually does refer to a class 3517 // template, alias template, or template template parameter, and 3518 // therefore cannot be a non-type template argument. 3519 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) 3520 << Arg.getSourceRange(); 3521 3522 Diag(Param->getLocation(), diag::note_template_param_here); 3523 return true; 3524 3525 case TemplateArgument::Type: { 3526 // We have a non-type template parameter but the template 3527 // argument is a type. 3528 3529 // C++ [temp.arg]p2: 3530 // In a template-argument, an ambiguity between a type-id and 3531 // an expression is resolved to a type-id, regardless of the 3532 // form of the corresponding template-parameter. 3533 // 3534 // We warn specifically about this case, since it can be rather 3535 // confusing for users. 3536 QualType T = Arg.getArgument().getAsType(); 3537 SourceRange SR = Arg.getSourceRange(); 3538 if (T->isFunctionType()) 3539 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; 3540 else 3541 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; 3542 Diag(Param->getLocation(), diag::note_template_param_here); 3543 return true; 3544 } 3545 3546 case TemplateArgument::Pack: 3547 llvm_unreachable("Caller must expand template argument packs"); 3548 } 3549 3550 return false; 3551 } 3552 3553 3554 // Check template template parameters. 3555 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param); 3556 3557 // Substitute into the template parameter list of the template 3558 // template parameter, since previously-supplied template arguments 3559 // may appear within the template template parameter. 3560 { 3561 // Set up a template instantiation context. 3562 LocalInstantiationScope Scope(*this); 3563 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 3564 TempParm, Converted, 3565 SourceRange(TemplateLoc, RAngleLoc)); 3566 if (Inst.isInvalid()) 3567 return true; 3568 3569 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 3570 Converted.data(), Converted.size()); 3571 TempParm = cast_or_null<TemplateTemplateParmDecl>( 3572 SubstDecl(TempParm, CurContext, 3573 MultiLevelTemplateArgumentList(TemplateArgs))); 3574 if (!TempParm) 3575 return true; 3576 } 3577 3578 switch (Arg.getArgument().getKind()) { 3579 case TemplateArgument::Null: 3580 llvm_unreachable("Should never see a NULL template argument here"); 3581 3582 case TemplateArgument::Template: 3583 case TemplateArgument::TemplateExpansion: 3584 if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex)) 3585 return true; 3586 3587 Converted.push_back(Arg.getArgument()); 3588 break; 3589 3590 case TemplateArgument::Expression: 3591 case TemplateArgument::Type: 3592 // We have a template template parameter but the template 3593 // argument does not refer to a template. 3594 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template) 3595 << getLangOpts().CPlusPlus11; 3596 return true; 3597 3598 case TemplateArgument::Declaration: 3599 llvm_unreachable("Declaration argument with template template parameter"); 3600 case TemplateArgument::Integral: 3601 llvm_unreachable("Integral argument with template template parameter"); 3602 case TemplateArgument::NullPtr: 3603 llvm_unreachable("Null pointer argument with template template parameter"); 3604 3605 case TemplateArgument::Pack: 3606 llvm_unreachable("Caller must expand template argument packs"); 3607 } 3608 3609 return false; 3610 } 3611 3612 /// \brief Diagnose an arity mismatch in the 3613 static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template, 3614 SourceLocation TemplateLoc, 3615 TemplateArgumentListInfo &TemplateArgs) { 3616 TemplateParameterList *Params = Template->getTemplateParameters(); 3617 unsigned NumParams = Params->size(); 3618 unsigned NumArgs = TemplateArgs.size(); 3619 3620 SourceRange Range; 3621 if (NumArgs > NumParams) 3622 Range = SourceRange(TemplateArgs[NumParams].getLocation(), 3623 TemplateArgs.getRAngleLoc()); 3624 S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 3625 << (NumArgs > NumParams) 3626 << (isa<ClassTemplateDecl>(Template)? 0 : 3627 isa<FunctionTemplateDecl>(Template)? 1 : 3628 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 3629 << Template << Range; 3630 S.Diag(Template->getLocation(), diag::note_template_decl_here) 3631 << Params->getSourceRange(); 3632 return true; 3633 } 3634 3635 /// \brief Check whether the template parameter is a pack expansion, and if so, 3636 /// determine the number of parameters produced by that expansion. For instance: 3637 /// 3638 /// \code 3639 /// template<typename ...Ts> struct A { 3640 /// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B; 3641 /// }; 3642 /// \endcode 3643 /// 3644 /// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us 3645 /// is not a pack expansion, so returns an empty Optional. 3646 static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) { 3647 if (NonTypeTemplateParmDecl *NTTP 3648 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 3649 if (NTTP->isExpandedParameterPack()) 3650 return NTTP->getNumExpansionTypes(); 3651 } 3652 3653 if (TemplateTemplateParmDecl *TTP 3654 = dyn_cast<TemplateTemplateParmDecl>(Param)) { 3655 if (TTP->isExpandedParameterPack()) 3656 return TTP->getNumExpansionTemplateParameters(); 3657 } 3658 3659 return None; 3660 } 3661 3662 /// \brief Check that the given template argument list is well-formed 3663 /// for specializing the given template. 3664 bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, 3665 SourceLocation TemplateLoc, 3666 TemplateArgumentListInfo &TemplateArgs, 3667 bool PartialTemplateArgs, 3668 SmallVectorImpl<TemplateArgument> &Converted) { 3669 // Make a copy of the template arguments for processing. Only make the 3670 // changes at the end when successful in matching the arguments to the 3671 // template. 3672 TemplateArgumentListInfo NewArgs = TemplateArgs; 3673 3674 TemplateParameterList *Params = Template->getTemplateParameters(); 3675 3676 SourceLocation RAngleLoc = NewArgs.getRAngleLoc(); 3677 3678 // C++ [temp.arg]p1: 3679 // [...] The type and form of each template-argument specified in 3680 // a template-id shall match the type and form specified for the 3681 // corresponding parameter declared by the template in its 3682 // template-parameter-list. 3683 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template); 3684 SmallVector<TemplateArgument, 2> ArgumentPack; 3685 unsigned ArgIdx = 0, NumArgs = NewArgs.size(); 3686 LocalInstantiationScope InstScope(*this, true); 3687 for (TemplateParameterList::iterator Param = Params->begin(), 3688 ParamEnd = Params->end(); 3689 Param != ParamEnd; /* increment in loop */) { 3690 // If we have an expanded parameter pack, make sure we don't have too 3691 // many arguments. 3692 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) { 3693 if (*Expansions == ArgumentPack.size()) { 3694 // We're done with this parameter pack. Pack up its arguments and add 3695 // them to the list. 3696 Converted.push_back( 3697 TemplateArgument::CreatePackCopy(Context, 3698 ArgumentPack.data(), 3699 ArgumentPack.size())); 3700 ArgumentPack.clear(); 3701 3702 // This argument is assigned to the next parameter. 3703 ++Param; 3704 continue; 3705 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) { 3706 // Not enough arguments for this parameter pack. 3707 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 3708 << false 3709 << (isa<ClassTemplateDecl>(Template)? 0 : 3710 isa<FunctionTemplateDecl>(Template)? 1 : 3711 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 3712 << Template; 3713 Diag(Template->getLocation(), diag::note_template_decl_here) 3714 << Params->getSourceRange(); 3715 return true; 3716 } 3717 } 3718 3719 if (ArgIdx < NumArgs) { 3720 // Check the template argument we were given. 3721 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template, 3722 TemplateLoc, RAngleLoc, 3723 ArgumentPack.size(), Converted)) 3724 return true; 3725 3726 bool PackExpansionIntoNonPack = 3727 NewArgs[ArgIdx].getArgument().isPackExpansion() && 3728 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param)); 3729 if (PackExpansionIntoNonPack && isa<TypeAliasTemplateDecl>(Template)) { 3730 // Core issue 1430: we have a pack expansion as an argument to an 3731 // alias template, and it's not part of a parameter pack. This 3732 // can't be canonicalized, so reject it now. 3733 Diag(NewArgs[ArgIdx].getLocation(), 3734 diag::err_alias_template_expansion_into_fixed_list) 3735 << NewArgs[ArgIdx].getSourceRange(); 3736 Diag((*Param)->getLocation(), diag::note_template_param_here); 3737 return true; 3738 } 3739 3740 // We're now done with this argument. 3741 ++ArgIdx; 3742 3743 if ((*Param)->isTemplateParameterPack()) { 3744 // The template parameter was a template parameter pack, so take the 3745 // deduced argument and place it on the argument pack. Note that we 3746 // stay on the same template parameter so that we can deduce more 3747 // arguments. 3748 ArgumentPack.push_back(Converted.pop_back_val()); 3749 } else { 3750 // Move to the next template parameter. 3751 ++Param; 3752 } 3753 3754 // If we just saw a pack expansion into a non-pack, then directly convert 3755 // the remaining arguments, because we don't know what parameters they'll 3756 // match up with. 3757 if (PackExpansionIntoNonPack) { 3758 if (!ArgumentPack.empty()) { 3759 // If we were part way through filling in an expanded parameter pack, 3760 // fall back to just producing individual arguments. 3761 Converted.insert(Converted.end(), 3762 ArgumentPack.begin(), ArgumentPack.end()); 3763 ArgumentPack.clear(); 3764 } 3765 3766 while (ArgIdx < NumArgs) { 3767 Converted.push_back(NewArgs[ArgIdx].getArgument()); 3768 ++ArgIdx; 3769 } 3770 3771 return false; 3772 } 3773 3774 continue; 3775 } 3776 3777 // If we're checking a partial template argument list, we're done. 3778 if (PartialTemplateArgs) { 3779 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty()) 3780 Converted.push_back(TemplateArgument::CreatePackCopy(Context, 3781 ArgumentPack.data(), 3782 ArgumentPack.size())); 3783 3784 return false; 3785 } 3786 3787 // If we have a template parameter pack with no more corresponding 3788 // arguments, just break out now and we'll fill in the argument pack below. 3789 if ((*Param)->isTemplateParameterPack()) { 3790 assert(!getExpandedPackSize(*Param) && 3791 "Should have dealt with this already"); 3792 3793 // A non-expanded parameter pack before the end of the parameter list 3794 // only occurs for an ill-formed template parameter list, unless we've 3795 // got a partial argument list for a function template, so just bail out. 3796 if (Param + 1 != ParamEnd) 3797 return true; 3798 3799 Converted.push_back(TemplateArgument::CreatePackCopy(Context, 3800 ArgumentPack.data(), 3801 ArgumentPack.size())); 3802 ArgumentPack.clear(); 3803 3804 ++Param; 3805 continue; 3806 } 3807 3808 // Check whether we have a default argument. 3809 TemplateArgumentLoc Arg; 3810 3811 // Retrieve the default template argument from the template 3812 // parameter. For each kind of template parameter, we substitute the 3813 // template arguments provided thus far and any "outer" template arguments 3814 // (when the template parameter was part of a nested template) into 3815 // the default argument. 3816 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) { 3817 if (!TTP->hasDefaultArgument()) 3818 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs); 3819 3820 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this, 3821 Template, 3822 TemplateLoc, 3823 RAngleLoc, 3824 TTP, 3825 Converted); 3826 if (!ArgType) 3827 return true; 3828 3829 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), 3830 ArgType); 3831 } else if (NonTypeTemplateParmDecl *NTTP 3832 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 3833 if (!NTTP->hasDefaultArgument()) 3834 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs); 3835 3836 ExprResult E = SubstDefaultTemplateArgument(*this, Template, 3837 TemplateLoc, 3838 RAngleLoc, 3839 NTTP, 3840 Converted); 3841 if (E.isInvalid()) 3842 return true; 3843 3844 Expr *Ex = E.getAs<Expr>(); 3845 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); 3846 } else { 3847 TemplateTemplateParmDecl *TempParm 3848 = cast<TemplateTemplateParmDecl>(*Param); 3849 3850 if (!TempParm->hasDefaultArgument()) 3851 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs); 3852 3853 NestedNameSpecifierLoc QualifierLoc; 3854 TemplateName Name = SubstDefaultTemplateArgument(*this, Template, 3855 TemplateLoc, 3856 RAngleLoc, 3857 TempParm, 3858 Converted, 3859 QualifierLoc); 3860 if (Name.isNull()) 3861 return true; 3862 3863 Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc, 3864 TempParm->getDefaultArgument().getTemplateNameLoc()); 3865 } 3866 3867 // Introduce an instantiation record that describes where we are using 3868 // the default template argument. 3869 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted, 3870 SourceRange(TemplateLoc, RAngleLoc)); 3871 if (Inst.isInvalid()) 3872 return true; 3873 3874 // Check the default template argument. 3875 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, 3876 RAngleLoc, 0, Converted)) 3877 return true; 3878 3879 // Core issue 150 (assumed resolution): if this is a template template 3880 // parameter, keep track of the default template arguments from the 3881 // template definition. 3882 if (isTemplateTemplateParameter) 3883 NewArgs.addArgument(Arg); 3884 3885 // Move to the next template parameter and argument. 3886 ++Param; 3887 ++ArgIdx; 3888 } 3889 3890 // If we're performing a partial argument substitution, allow any trailing 3891 // pack expansions; they might be empty. This can happen even if 3892 // PartialTemplateArgs is false (the list of arguments is complete but 3893 // still dependent). 3894 if (ArgIdx < NumArgs && CurrentInstantiationScope && 3895 CurrentInstantiationScope->getPartiallySubstitutedPack()) { 3896 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion()) 3897 Converted.push_back(NewArgs[ArgIdx++].getArgument()); 3898 } 3899 3900 // If we have any leftover arguments, then there were too many arguments. 3901 // Complain and fail. 3902 if (ArgIdx < NumArgs) 3903 return diagnoseArityMismatch(*this, Template, TemplateLoc, NewArgs); 3904 3905 // No problems found with the new argument list, propagate changes back 3906 // to caller. 3907 TemplateArgs = NewArgs; 3908 3909 return false; 3910 } 3911 3912 namespace { 3913 class UnnamedLocalNoLinkageFinder 3914 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool> 3915 { 3916 Sema &S; 3917 SourceRange SR; 3918 3919 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited; 3920 3921 public: 3922 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { } 3923 3924 bool Visit(QualType T) { 3925 return inherited::Visit(T.getTypePtr()); 3926 } 3927 3928 #define TYPE(Class, Parent) \ 3929 bool Visit##Class##Type(const Class##Type *); 3930 #define ABSTRACT_TYPE(Class, Parent) \ 3931 bool Visit##Class##Type(const Class##Type *) { return false; } 3932 #define NON_CANONICAL_TYPE(Class, Parent) \ 3933 bool Visit##Class##Type(const Class##Type *) { return false; } 3934 #include "clang/AST/TypeNodes.def" 3935 3936 bool VisitTagDecl(const TagDecl *Tag); 3937 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS); 3938 }; 3939 } 3940 3941 bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) { 3942 return false; 3943 } 3944 3945 bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) { 3946 return Visit(T->getElementType()); 3947 } 3948 3949 bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) { 3950 return Visit(T->getPointeeType()); 3951 } 3952 3953 bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType( 3954 const BlockPointerType* T) { 3955 return Visit(T->getPointeeType()); 3956 } 3957 3958 bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType( 3959 const LValueReferenceType* T) { 3960 return Visit(T->getPointeeType()); 3961 } 3962 3963 bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType( 3964 const RValueReferenceType* T) { 3965 return Visit(T->getPointeeType()); 3966 } 3967 3968 bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType( 3969 const MemberPointerType* T) { 3970 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0)); 3971 } 3972 3973 bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType( 3974 const ConstantArrayType* T) { 3975 return Visit(T->getElementType()); 3976 } 3977 3978 bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType( 3979 const IncompleteArrayType* T) { 3980 return Visit(T->getElementType()); 3981 } 3982 3983 bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType( 3984 const VariableArrayType* T) { 3985 return Visit(T->getElementType()); 3986 } 3987 3988 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType( 3989 const DependentSizedArrayType* T) { 3990 return Visit(T->getElementType()); 3991 } 3992 3993 bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType( 3994 const DependentSizedExtVectorType* T) { 3995 return Visit(T->getElementType()); 3996 } 3997 3998 bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) { 3999 return Visit(T->getElementType()); 4000 } 4001 4002 bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) { 4003 return Visit(T->getElementType()); 4004 } 4005 4006 bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType( 4007 const FunctionProtoType* T) { 4008 for (const auto &A : T->param_types()) { 4009 if (Visit(A)) 4010 return true; 4011 } 4012 4013 return Visit(T->getReturnType()); 4014 } 4015 4016 bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType( 4017 const FunctionNoProtoType* T) { 4018 return Visit(T->getReturnType()); 4019 } 4020 4021 bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType( 4022 const UnresolvedUsingType*) { 4023 return false; 4024 } 4025 4026 bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) { 4027 return false; 4028 } 4029 4030 bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) { 4031 return Visit(T->getUnderlyingType()); 4032 } 4033 4034 bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) { 4035 return false; 4036 } 4037 4038 bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType( 4039 const UnaryTransformType*) { 4040 return false; 4041 } 4042 4043 bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) { 4044 return Visit(T->getDeducedType()); 4045 } 4046 4047 bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) { 4048 return VisitTagDecl(T->getDecl()); 4049 } 4050 4051 bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) { 4052 return VisitTagDecl(T->getDecl()); 4053 } 4054 4055 bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType( 4056 const TemplateTypeParmType*) { 4057 return false; 4058 } 4059 4060 bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType( 4061 const SubstTemplateTypeParmPackType *) { 4062 return false; 4063 } 4064 4065 bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType( 4066 const TemplateSpecializationType*) { 4067 return false; 4068 } 4069 4070 bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType( 4071 const InjectedClassNameType* T) { 4072 return VisitTagDecl(T->getDecl()); 4073 } 4074 4075 bool UnnamedLocalNoLinkageFinder::VisitDependentNameType( 4076 const DependentNameType* T) { 4077 return VisitNestedNameSpecifier(T->getQualifier()); 4078 } 4079 4080 bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType( 4081 const DependentTemplateSpecializationType* T) { 4082 return VisitNestedNameSpecifier(T->getQualifier()); 4083 } 4084 4085 bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType( 4086 const PackExpansionType* T) { 4087 return Visit(T->getPattern()); 4088 } 4089 4090 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) { 4091 return false; 4092 } 4093 4094 bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType( 4095 const ObjCInterfaceType *) { 4096 return false; 4097 } 4098 4099 bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType( 4100 const ObjCObjectPointerType *) { 4101 return false; 4102 } 4103 4104 bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) { 4105 return Visit(T->getValueType()); 4106 } 4107 4108 bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) { 4109 if (Tag->getDeclContext()->isFunctionOrMethod()) { 4110 S.Diag(SR.getBegin(), 4111 S.getLangOpts().CPlusPlus11 ? 4112 diag::warn_cxx98_compat_template_arg_local_type : 4113 diag::ext_template_arg_local_type) 4114 << S.Context.getTypeDeclType(Tag) << SR; 4115 return true; 4116 } 4117 4118 if (!Tag->hasNameForLinkage()) { 4119 S.Diag(SR.getBegin(), 4120 S.getLangOpts().CPlusPlus11 ? 4121 diag::warn_cxx98_compat_template_arg_unnamed_type : 4122 diag::ext_template_arg_unnamed_type) << SR; 4123 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here); 4124 return true; 4125 } 4126 4127 return false; 4128 } 4129 4130 bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier( 4131 NestedNameSpecifier *NNS) { 4132 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix())) 4133 return true; 4134 4135 switch (NNS->getKind()) { 4136 case NestedNameSpecifier::Identifier: 4137 case NestedNameSpecifier::Namespace: 4138 case NestedNameSpecifier::NamespaceAlias: 4139 case NestedNameSpecifier::Global: 4140 case NestedNameSpecifier::Super: 4141 return false; 4142 4143 case NestedNameSpecifier::TypeSpec: 4144 case NestedNameSpecifier::TypeSpecWithTemplate: 4145 return Visit(QualType(NNS->getAsType(), 0)); 4146 } 4147 llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); 4148 } 4149 4150 4151 /// \brief Check a template argument against its corresponding 4152 /// template type parameter. 4153 /// 4154 /// This routine implements the semantics of C++ [temp.arg.type]. It 4155 /// returns true if an error occurred, and false otherwise. 4156 bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, 4157 TypeSourceInfo *ArgInfo) { 4158 assert(ArgInfo && "invalid TypeSourceInfo"); 4159 QualType Arg = ArgInfo->getType(); 4160 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 4161 4162 if (Arg->isVariablyModifiedType()) { 4163 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg; 4164 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) { 4165 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR; 4166 } 4167 4168 // C++03 [temp.arg.type]p2: 4169 // A local type, a type with no linkage, an unnamed type or a type 4170 // compounded from any of these types shall not be used as a 4171 // template-argument for a template type-parameter. 4172 // 4173 // C++11 allows these, and even in C++03 we allow them as an extension with 4174 // a warning. 4175 bool NeedsCheck; 4176 if (LangOpts.CPlusPlus11) 4177 NeedsCheck = 4178 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_unnamed_type, 4179 SR.getBegin()) || 4180 !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_local_type, 4181 SR.getBegin()); 4182 else 4183 NeedsCheck = Arg->hasUnnamedOrLocalType(); 4184 4185 if (NeedsCheck) { 4186 UnnamedLocalNoLinkageFinder Finder(*this, SR); 4187 (void)Finder.Visit(Context.getCanonicalType(Arg)); 4188 } 4189 4190 return false; 4191 } 4192 4193 enum NullPointerValueKind { 4194 NPV_NotNullPointer, 4195 NPV_NullPointer, 4196 NPV_Error 4197 }; 4198 4199 /// \brief Determine whether the given template argument is a null pointer 4200 /// value of the appropriate type. 4201 static NullPointerValueKind 4202 isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param, 4203 QualType ParamType, Expr *Arg) { 4204 if (Arg->isValueDependent() || Arg->isTypeDependent()) 4205 return NPV_NotNullPointer; 4206 4207 if (!S.getLangOpts().CPlusPlus11) 4208 return NPV_NotNullPointer; 4209 4210 // Determine whether we have a constant expression. 4211 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg); 4212 if (ArgRV.isInvalid()) 4213 return NPV_Error; 4214 Arg = ArgRV.get(); 4215 4216 Expr::EvalResult EvalResult; 4217 SmallVector<PartialDiagnosticAt, 8> Notes; 4218 EvalResult.Diag = &Notes; 4219 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) || 4220 EvalResult.HasSideEffects) { 4221 SourceLocation DiagLoc = Arg->getExprLoc(); 4222 4223 // If our only note is the usual "invalid subexpression" note, just point 4224 // the caret at its location rather than producing an essentially 4225 // redundant note. 4226 if (Notes.size() == 1 && Notes[0].second.getDiagID() == 4227 diag::note_invalid_subexpr_in_const_expr) { 4228 DiagLoc = Notes[0].first; 4229 Notes.clear(); 4230 } 4231 4232 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant) 4233 << Arg->getType() << Arg->getSourceRange(); 4234 for (unsigned I = 0, N = Notes.size(); I != N; ++I) 4235 S.Diag(Notes[I].first, Notes[I].second); 4236 4237 S.Diag(Param->getLocation(), diag::note_template_param_here); 4238 return NPV_Error; 4239 } 4240 4241 // C++11 [temp.arg.nontype]p1: 4242 // - an address constant expression of type std::nullptr_t 4243 if (Arg->getType()->isNullPtrType()) 4244 return NPV_NullPointer; 4245 4246 // - a constant expression that evaluates to a null pointer value (4.10); or 4247 // - a constant expression that evaluates to a null member pointer value 4248 // (4.11); or 4249 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) || 4250 (EvalResult.Val.isMemberPointer() && 4251 !EvalResult.Val.getMemberPointerDecl())) { 4252 // If our expression has an appropriate type, we've succeeded. 4253 bool ObjCLifetimeConversion; 4254 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) || 4255 S.IsQualificationConversion(Arg->getType(), ParamType, false, 4256 ObjCLifetimeConversion)) 4257 return NPV_NullPointer; 4258 4259 // The types didn't match, but we know we got a null pointer; complain, 4260 // then recover as if the types were correct. 4261 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant) 4262 << Arg->getType() << ParamType << Arg->getSourceRange(); 4263 S.Diag(Param->getLocation(), diag::note_template_param_here); 4264 return NPV_NullPointer; 4265 } 4266 4267 // If we don't have a null pointer value, but we do have a NULL pointer 4268 // constant, suggest a cast to the appropriate type. 4269 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) { 4270 std::string Code = "static_cast<" + ParamType.getAsString() + ">("; 4271 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant) 4272 << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code) 4273 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()), 4274 ")"); 4275 S.Diag(Param->getLocation(), diag::note_template_param_here); 4276 return NPV_NullPointer; 4277 } 4278 4279 // FIXME: If we ever want to support general, address-constant expressions 4280 // as non-type template arguments, we should return the ExprResult here to 4281 // be interpreted by the caller. 4282 return NPV_NotNullPointer; 4283 } 4284 4285 /// \brief Checks whether the given template argument is compatible with its 4286 /// template parameter. 4287 static bool CheckTemplateArgumentIsCompatibleWithParameter( 4288 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn, 4289 Expr *Arg, QualType ArgType) { 4290 bool ObjCLifetimeConversion; 4291 if (ParamType->isPointerType() && 4292 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() && 4293 S.IsQualificationConversion(ArgType, ParamType, false, 4294 ObjCLifetimeConversion)) { 4295 // For pointer-to-object types, qualification conversions are 4296 // permitted. 4297 } else { 4298 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) { 4299 if (!ParamRef->getPointeeType()->isFunctionType()) { 4300 // C++ [temp.arg.nontype]p5b3: 4301 // For a non-type template-parameter of type reference to 4302 // object, no conversions apply. The type referred to by the 4303 // reference may be more cv-qualified than the (otherwise 4304 // identical) type of the template- argument. The 4305 // template-parameter is bound directly to the 4306 // template-argument, which shall be an lvalue. 4307 4308 // FIXME: Other qualifiers? 4309 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers(); 4310 unsigned ArgQuals = ArgType.getCVRQualifiers(); 4311 4312 if ((ParamQuals | ArgQuals) != ParamQuals) { 4313 S.Diag(Arg->getLocStart(), 4314 diag::err_template_arg_ref_bind_ignores_quals) 4315 << ParamType << Arg->getType() << Arg->getSourceRange(); 4316 S.Diag(Param->getLocation(), diag::note_template_param_here); 4317 return true; 4318 } 4319 } 4320 } 4321 4322 // At this point, the template argument refers to an object or 4323 // function with external linkage. We now need to check whether the 4324 // argument and parameter types are compatible. 4325 if (!S.Context.hasSameUnqualifiedType(ArgType, 4326 ParamType.getNonReferenceType())) { 4327 // We can't perform this conversion or binding. 4328 if (ParamType->isReferenceType()) 4329 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind) 4330 << ParamType << ArgIn->getType() << Arg->getSourceRange(); 4331 else 4332 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) 4333 << ArgIn->getType() << ParamType << Arg->getSourceRange(); 4334 S.Diag(Param->getLocation(), diag::note_template_param_here); 4335 return true; 4336 } 4337 } 4338 4339 return false; 4340 } 4341 4342 /// \brief Checks whether the given template argument is the address 4343 /// of an object or function according to C++ [temp.arg.nontype]p1. 4344 static bool 4345 CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S, 4346 NonTypeTemplateParmDecl *Param, 4347 QualType ParamType, 4348 Expr *ArgIn, 4349 TemplateArgument &Converted) { 4350 bool Invalid = false; 4351 Expr *Arg = ArgIn; 4352 QualType ArgType = Arg->getType(); 4353 4354 bool AddressTaken = false; 4355 SourceLocation AddrOpLoc; 4356 if (S.getLangOpts().MicrosoftExt) { 4357 // Microsoft Visual C++ strips all casts, allows an arbitrary number of 4358 // dereference and address-of operators. 4359 Arg = Arg->IgnoreParenCasts(); 4360 4361 bool ExtWarnMSTemplateArg = false; 4362 UnaryOperatorKind FirstOpKind; 4363 SourceLocation FirstOpLoc; 4364 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 4365 UnaryOperatorKind UnOpKind = UnOp->getOpcode(); 4366 if (UnOpKind == UO_Deref) 4367 ExtWarnMSTemplateArg = true; 4368 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) { 4369 Arg = UnOp->getSubExpr()->IgnoreParenCasts(); 4370 if (!AddrOpLoc.isValid()) { 4371 FirstOpKind = UnOpKind; 4372 FirstOpLoc = UnOp->getOperatorLoc(); 4373 } 4374 } else 4375 break; 4376 } 4377 if (FirstOpLoc.isValid()) { 4378 if (ExtWarnMSTemplateArg) 4379 S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument) 4380 << ArgIn->getSourceRange(); 4381 4382 if (FirstOpKind == UO_AddrOf) 4383 AddressTaken = true; 4384 else if (Arg->getType()->isPointerType()) { 4385 // We cannot let pointers get dereferenced here, that is obviously not a 4386 // constant expression. 4387 assert(FirstOpKind == UO_Deref); 4388 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 4389 << Arg->getSourceRange(); 4390 } 4391 } 4392 } else { 4393 // See through any implicit casts we added to fix the type. 4394 Arg = Arg->IgnoreImpCasts(); 4395 4396 // C++ [temp.arg.nontype]p1: 4397 // 4398 // A template-argument for a non-type, non-template 4399 // template-parameter shall be one of: [...] 4400 // 4401 // -- the address of an object or function with external 4402 // linkage, including function templates and function 4403 // template-ids but excluding non-static class members, 4404 // expressed as & id-expression where the & is optional if 4405 // the name refers to a function or array, or if the 4406 // corresponding template-parameter is a reference; or 4407 4408 // In C++98/03 mode, give an extension warning on any extra parentheses. 4409 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 4410 bool ExtraParens = false; 4411 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 4412 if (!Invalid && !ExtraParens) { 4413 S.Diag(Arg->getLocStart(), 4414 S.getLangOpts().CPlusPlus11 4415 ? diag::warn_cxx98_compat_template_arg_extra_parens 4416 : diag::ext_template_arg_extra_parens) 4417 << Arg->getSourceRange(); 4418 ExtraParens = true; 4419 } 4420 4421 Arg = Parens->getSubExpr(); 4422 } 4423 4424 while (SubstNonTypeTemplateParmExpr *subst = 4425 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg)) 4426 Arg = subst->getReplacement()->IgnoreImpCasts(); 4427 4428 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 4429 if (UnOp->getOpcode() == UO_AddrOf) { 4430 Arg = UnOp->getSubExpr(); 4431 AddressTaken = true; 4432 AddrOpLoc = UnOp->getOperatorLoc(); 4433 } 4434 } 4435 4436 while (SubstNonTypeTemplateParmExpr *subst = 4437 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg)) 4438 Arg = subst->getReplacement()->IgnoreImpCasts(); 4439 } 4440 4441 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg); 4442 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr; 4443 4444 // If our parameter has pointer type, check for a null template value. 4445 if (ParamType->isPointerType() || ParamType->isNullPtrType()) { 4446 NullPointerValueKind NPV; 4447 // dllimport'd entities aren't constant but are available inside of template 4448 // arguments. 4449 if (Entity && Entity->hasAttr<DLLImportAttr>()) 4450 NPV = NPV_NotNullPointer; 4451 else 4452 NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn); 4453 switch (NPV) { 4454 case NPV_NullPointer: 4455 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); 4456 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType), 4457 /*isNullPtr=*/true); 4458 return false; 4459 4460 case NPV_Error: 4461 return true; 4462 4463 case NPV_NotNullPointer: 4464 break; 4465 } 4466 } 4467 4468 // Stop checking the precise nature of the argument if it is value dependent, 4469 // it should be checked when instantiated. 4470 if (Arg->isValueDependent()) { 4471 Converted = TemplateArgument(ArgIn); 4472 return false; 4473 } 4474 4475 if (isa<CXXUuidofExpr>(Arg)) { 4476 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, 4477 ArgIn, Arg, ArgType)) 4478 return true; 4479 4480 Converted = TemplateArgument(ArgIn); 4481 return false; 4482 } 4483 4484 if (!DRE) { 4485 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 4486 << Arg->getSourceRange(); 4487 S.Diag(Param->getLocation(), diag::note_template_param_here); 4488 return true; 4489 } 4490 4491 // Cannot refer to non-static data members 4492 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) { 4493 S.Diag(Arg->getLocStart(), diag::err_template_arg_field) 4494 << Entity << Arg->getSourceRange(); 4495 S.Diag(Param->getLocation(), diag::note_template_param_here); 4496 return true; 4497 } 4498 4499 // Cannot refer to non-static member functions 4500 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) { 4501 if (!Method->isStatic()) { 4502 S.Diag(Arg->getLocStart(), diag::err_template_arg_method) 4503 << Method << Arg->getSourceRange(); 4504 S.Diag(Param->getLocation(), diag::note_template_param_here); 4505 return true; 4506 } 4507 } 4508 4509 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity); 4510 VarDecl *Var = dyn_cast<VarDecl>(Entity); 4511 4512 // A non-type template argument must refer to an object or function. 4513 if (!Func && !Var) { 4514 // We found something, but we don't know specifically what it is. 4515 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func) 4516 << Arg->getSourceRange(); 4517 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); 4518 return true; 4519 } 4520 4521 // Address / reference template args must have external linkage in C++98. 4522 if (Entity->getFormalLinkage() == InternalLinkage) { 4523 S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ? 4524 diag::warn_cxx98_compat_template_arg_object_internal : 4525 diag::ext_template_arg_object_internal) 4526 << !Func << Entity << Arg->getSourceRange(); 4527 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object) 4528 << !Func; 4529 } else if (!Entity->hasLinkage()) { 4530 S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage) 4531 << !Func << Entity << Arg->getSourceRange(); 4532 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object) 4533 << !Func; 4534 return true; 4535 } 4536 4537 if (Func) { 4538 // If the template parameter has pointer type, the function decays. 4539 if (ParamType->isPointerType() && !AddressTaken) 4540 ArgType = S.Context.getPointerType(Func->getType()); 4541 else if (AddressTaken && ParamType->isReferenceType()) { 4542 // If we originally had an address-of operator, but the 4543 // parameter has reference type, complain and (if things look 4544 // like they will work) drop the address-of operator. 4545 if (!S.Context.hasSameUnqualifiedType(Func->getType(), 4546 ParamType.getNonReferenceType())) { 4547 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 4548 << ParamType; 4549 S.Diag(Param->getLocation(), diag::note_template_param_here); 4550 return true; 4551 } 4552 4553 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 4554 << ParamType 4555 << FixItHint::CreateRemoval(AddrOpLoc); 4556 S.Diag(Param->getLocation(), diag::note_template_param_here); 4557 4558 ArgType = Func->getType(); 4559 } 4560 } else { 4561 // A value of reference type is not an object. 4562 if (Var->getType()->isReferenceType()) { 4563 S.Diag(Arg->getLocStart(), 4564 diag::err_template_arg_reference_var) 4565 << Var->getType() << Arg->getSourceRange(); 4566 S.Diag(Param->getLocation(), diag::note_template_param_here); 4567 return true; 4568 } 4569 4570 // A template argument must have static storage duration. 4571 if (Var->getTLSKind()) { 4572 S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local) 4573 << Arg->getSourceRange(); 4574 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here); 4575 return true; 4576 } 4577 4578 // If the template parameter has pointer type, we must have taken 4579 // the address of this object. 4580 if (ParamType->isReferenceType()) { 4581 if (AddressTaken) { 4582 // If we originally had an address-of operator, but the 4583 // parameter has reference type, complain and (if things look 4584 // like they will work) drop the address-of operator. 4585 if (!S.Context.hasSameUnqualifiedType(Var->getType(), 4586 ParamType.getNonReferenceType())) { 4587 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 4588 << ParamType; 4589 S.Diag(Param->getLocation(), diag::note_template_param_here); 4590 return true; 4591 } 4592 4593 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 4594 << ParamType 4595 << FixItHint::CreateRemoval(AddrOpLoc); 4596 S.Diag(Param->getLocation(), diag::note_template_param_here); 4597 4598 ArgType = Var->getType(); 4599 } 4600 } else if (!AddressTaken && ParamType->isPointerType()) { 4601 if (Var->getType()->isArrayType()) { 4602 // Array-to-pointer decay. 4603 ArgType = S.Context.getArrayDecayedType(Var->getType()); 4604 } else { 4605 // If the template parameter has pointer type but the address of 4606 // this object was not taken, complain and (possibly) recover by 4607 // taking the address of the entity. 4608 ArgType = S.Context.getPointerType(Var->getType()); 4609 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) { 4610 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 4611 << ParamType; 4612 S.Diag(Param->getLocation(), diag::note_template_param_here); 4613 return true; 4614 } 4615 4616 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 4617 << ParamType 4618 << FixItHint::CreateInsertion(Arg->getLocStart(), "&"); 4619 4620 S.Diag(Param->getLocation(), diag::note_template_param_here); 4621 } 4622 } 4623 } 4624 4625 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn, 4626 Arg, ArgType)) 4627 return true; 4628 4629 // Create the template argument. 4630 Converted = 4631 TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()), ParamType); 4632 S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false); 4633 return false; 4634 } 4635 4636 /// \brief Checks whether the given template argument is a pointer to 4637 /// member constant according to C++ [temp.arg.nontype]p1. 4638 static bool CheckTemplateArgumentPointerToMember(Sema &S, 4639 NonTypeTemplateParmDecl *Param, 4640 QualType ParamType, 4641 Expr *&ResultArg, 4642 TemplateArgument &Converted) { 4643 bool Invalid = false; 4644 4645 // Check for a null pointer value. 4646 Expr *Arg = ResultArg; 4647 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) { 4648 case NPV_Error: 4649 return true; 4650 case NPV_NullPointer: 4651 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); 4652 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType), 4653 /*isNullPtr*/true); 4654 if (S.Context.getTargetInfo().getCXXABI().isMicrosoft()) 4655 S.RequireCompleteType(Arg->getExprLoc(), ParamType, 0); 4656 return false; 4657 case NPV_NotNullPointer: 4658 break; 4659 } 4660 4661 bool ObjCLifetimeConversion; 4662 if (S.IsQualificationConversion(Arg->getType(), 4663 ParamType.getNonReferenceType(), 4664 false, ObjCLifetimeConversion)) { 4665 Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp, 4666 Arg->getValueKind()).get(); 4667 ResultArg = Arg; 4668 } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(), 4669 ParamType.getNonReferenceType())) { 4670 // We can't perform this conversion. 4671 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) 4672 << Arg->getType() << ParamType << Arg->getSourceRange(); 4673 S.Diag(Param->getLocation(), diag::note_template_param_here); 4674 return true; 4675 } 4676 4677 // See through any implicit casts we added to fix the type. 4678 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 4679 Arg = Cast->getSubExpr(); 4680 4681 // C++ [temp.arg.nontype]p1: 4682 // 4683 // A template-argument for a non-type, non-template 4684 // template-parameter shall be one of: [...] 4685 // 4686 // -- a pointer to member expressed as described in 5.3.1. 4687 DeclRefExpr *DRE = nullptr; 4688 4689 // In C++98/03 mode, give an extension warning on any extra parentheses. 4690 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 4691 bool ExtraParens = false; 4692 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 4693 if (!Invalid && !ExtraParens) { 4694 S.Diag(Arg->getLocStart(), 4695 S.getLangOpts().CPlusPlus11 ? 4696 diag::warn_cxx98_compat_template_arg_extra_parens : 4697 diag::ext_template_arg_extra_parens) 4698 << Arg->getSourceRange(); 4699 ExtraParens = true; 4700 } 4701 4702 Arg = Parens->getSubExpr(); 4703 } 4704 4705 while (SubstNonTypeTemplateParmExpr *subst = 4706 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg)) 4707 Arg = subst->getReplacement()->IgnoreImpCasts(); 4708 4709 // A pointer-to-member constant written &Class::member. 4710 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 4711 if (UnOp->getOpcode() == UO_AddrOf) { 4712 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 4713 if (DRE && !DRE->getQualifier()) 4714 DRE = nullptr; 4715 } 4716 } 4717 // A constant of pointer-to-member type. 4718 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) { 4719 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) { 4720 if (VD->getType()->isMemberPointerType()) { 4721 if (isa<NonTypeTemplateParmDecl>(VD)) { 4722 if (Arg->isTypeDependent() || Arg->isValueDependent()) { 4723 Converted = TemplateArgument(Arg); 4724 } else { 4725 VD = cast<ValueDecl>(VD->getCanonicalDecl()); 4726 Converted = TemplateArgument(VD, ParamType); 4727 } 4728 return Invalid; 4729 } 4730 } 4731 } 4732 4733 DRE = nullptr; 4734 } 4735 4736 if (!DRE) 4737 return S.Diag(Arg->getLocStart(), 4738 diag::err_template_arg_not_pointer_to_member_form) 4739 << Arg->getSourceRange(); 4740 4741 if (isa<FieldDecl>(DRE->getDecl()) || 4742 isa<IndirectFieldDecl>(DRE->getDecl()) || 4743 isa<CXXMethodDecl>(DRE->getDecl())) { 4744 assert((isa<FieldDecl>(DRE->getDecl()) || 4745 isa<IndirectFieldDecl>(DRE->getDecl()) || 4746 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && 4747 "Only non-static member pointers can make it here"); 4748 4749 // Okay: this is the address of a non-static member, and therefore 4750 // a member pointer constant. 4751 if (Arg->isTypeDependent() || Arg->isValueDependent()) { 4752 Converted = TemplateArgument(Arg); 4753 } else { 4754 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl()); 4755 Converted = TemplateArgument(D, ParamType); 4756 } 4757 return Invalid; 4758 } 4759 4760 // We found something else, but we don't know specifically what it is. 4761 S.Diag(Arg->getLocStart(), 4762 diag::err_template_arg_not_pointer_to_member_form) 4763 << Arg->getSourceRange(); 4764 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); 4765 return true; 4766 } 4767 4768 /// \brief Check a template argument against its corresponding 4769 /// non-type template parameter. 4770 /// 4771 /// This routine implements the semantics of C++ [temp.arg.nontype]. 4772 /// If an error occurred, it returns ExprError(); otherwise, it 4773 /// returns the converted template argument. \p ParamType is the 4774 /// type of the non-type template parameter after it has been instantiated. 4775 ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, 4776 QualType ParamType, Expr *Arg, 4777 TemplateArgument &Converted, 4778 CheckTemplateArgumentKind CTAK) { 4779 SourceLocation StartLoc = Arg->getLocStart(); 4780 4781 // If either the parameter has a dependent type or the argument is 4782 // type-dependent, there's nothing we can check now. 4783 if (ParamType->isDependentType() || Arg->isTypeDependent()) { 4784 // FIXME: Produce a cloned, canonical expression? 4785 Converted = TemplateArgument(Arg); 4786 return Arg; 4787 } 4788 4789 // We should have already dropped all cv-qualifiers by now. 4790 assert(!ParamType.hasQualifiers() && 4791 "non-type template parameter type cannot be qualified"); 4792 4793 if (CTAK == CTAK_Deduced && 4794 !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) { 4795 // C++ [temp.deduct.type]p17: 4796 // If, in the declaration of a function template with a non-type 4797 // template-parameter, the non-type template-parameter is used 4798 // in an expression in the function parameter-list and, if the 4799 // corresponding template-argument is deduced, the 4800 // template-argument type shall match the type of the 4801 // template-parameter exactly, except that a template-argument 4802 // deduced from an array bound may be of any integral type. 4803 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch) 4804 << Arg->getType().getUnqualifiedType() 4805 << ParamType.getUnqualifiedType(); 4806 Diag(Param->getLocation(), diag::note_template_param_here); 4807 return ExprError(); 4808 } 4809 4810 if (getLangOpts().CPlusPlus1z) { 4811 // FIXME: We can do some limited checking for a value-dependent but not 4812 // type-dependent argument. 4813 if (Arg->isValueDependent()) { 4814 Converted = TemplateArgument(Arg); 4815 return Arg; 4816 } 4817 4818 // C++1z [temp.arg.nontype]p1: 4819 // A template-argument for a non-type template parameter shall be 4820 // a converted constant expression of the type of the template-parameter. 4821 APValue Value; 4822 ExprResult ArgResult = CheckConvertedConstantExpression( 4823 Arg, ParamType, Value, CCEK_TemplateArg); 4824 if (ArgResult.isInvalid()) 4825 return ExprError(); 4826 4827 QualType CanonParamType = Context.getCanonicalType(ParamType); 4828 4829 // Convert the APValue to a TemplateArgument. 4830 switch (Value.getKind()) { 4831 case APValue::Uninitialized: 4832 assert(ParamType->isNullPtrType()); 4833 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true); 4834 break; 4835 case APValue::Int: 4836 assert(ParamType->isIntegralOrEnumerationType()); 4837 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType); 4838 break; 4839 case APValue::MemberPointer: { 4840 assert(ParamType->isMemberPointerType()); 4841 4842 // FIXME: We need TemplateArgument representation and mangling for these. 4843 if (!Value.getMemberPointerPath().empty()) { 4844 Diag(Arg->getLocStart(), 4845 diag::err_template_arg_member_ptr_base_derived_not_supported) 4846 << Value.getMemberPointerDecl() << ParamType 4847 << Arg->getSourceRange(); 4848 return ExprError(); 4849 } 4850 4851 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl()); 4852 Converted = VD ? TemplateArgument(VD, CanonParamType) 4853 : TemplateArgument(CanonParamType, /*isNullPtr*/true); 4854 break; 4855 } 4856 case APValue::LValue: { 4857 // For a non-type template-parameter of pointer or reference type, 4858 // the value of the constant expression shall not refer to 4859 assert(ParamType->isPointerType() || ParamType->isReferenceType() || 4860 ParamType->isNullPtrType()); 4861 // -- a temporary object 4862 // -- a string literal 4863 // -- the result of a typeid expression, or 4864 // -- a predefind __func__ variable 4865 if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) { 4866 if (isa<CXXUuidofExpr>(E)) { 4867 Converted = TemplateArgument(const_cast<Expr*>(E)); 4868 break; 4869 } 4870 Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 4871 << Arg->getSourceRange(); 4872 return ExprError(); 4873 } 4874 auto *VD = const_cast<ValueDecl *>( 4875 Value.getLValueBase().dyn_cast<const ValueDecl *>()); 4876 // -- a subobject 4877 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 && 4878 VD && VD->getType()->isArrayType() && 4879 Value.getLValuePath()[0].ArrayIndex == 0 && 4880 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) { 4881 // Per defect report (no number yet): 4882 // ... other than a pointer to the first element of a complete array 4883 // object. 4884 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() || 4885 Value.isLValueOnePastTheEnd()) { 4886 Diag(StartLoc, diag::err_non_type_template_arg_subobject) 4887 << Value.getAsString(Context, ParamType); 4888 return ExprError(); 4889 } 4890 assert((VD || !ParamType->isReferenceType()) && 4891 "null reference should not be a constant expression"); 4892 assert((!VD || !ParamType->isNullPtrType()) && 4893 "non-null value of type nullptr_t?"); 4894 Converted = VD ? TemplateArgument(VD, CanonParamType) 4895 : TemplateArgument(CanonParamType, /*isNullPtr*/true); 4896 break; 4897 } 4898 case APValue::AddrLabelDiff: 4899 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff); 4900 case APValue::Float: 4901 case APValue::ComplexInt: 4902 case APValue::ComplexFloat: 4903 case APValue::Vector: 4904 case APValue::Array: 4905 case APValue::Struct: 4906 case APValue::Union: 4907 llvm_unreachable("invalid kind for template argument"); 4908 } 4909 4910 return ArgResult.get(); 4911 } 4912 4913 // C++ [temp.arg.nontype]p5: 4914 // The following conversions are performed on each expression used 4915 // as a non-type template-argument. If a non-type 4916 // template-argument cannot be converted to the type of the 4917 // corresponding template-parameter then the program is 4918 // ill-formed. 4919 if (ParamType->isIntegralOrEnumerationType()) { 4920 // C++11: 4921 // -- for a non-type template-parameter of integral or 4922 // enumeration type, conversions permitted in a converted 4923 // constant expression are applied. 4924 // 4925 // C++98: 4926 // -- for a non-type template-parameter of integral or 4927 // enumeration type, integral promotions (4.5) and integral 4928 // conversions (4.7) are applied. 4929 4930 if (getLangOpts().CPlusPlus11) { 4931 // We can't check arbitrary value-dependent arguments. 4932 // FIXME: If there's no viable conversion to the template parameter type, 4933 // we should be able to diagnose that prior to instantiation. 4934 if (Arg->isValueDependent()) { 4935 Converted = TemplateArgument(Arg); 4936 return Arg; 4937 } 4938 4939 // C++ [temp.arg.nontype]p1: 4940 // A template-argument for a non-type, non-template template-parameter 4941 // shall be one of: 4942 // 4943 // -- for a non-type template-parameter of integral or enumeration 4944 // type, a converted constant expression of the type of the 4945 // template-parameter; or 4946 llvm::APSInt Value; 4947 ExprResult ArgResult = 4948 CheckConvertedConstantExpression(Arg, ParamType, Value, 4949 CCEK_TemplateArg); 4950 if (ArgResult.isInvalid()) 4951 return ExprError(); 4952 4953 // Widen the argument value to sizeof(parameter type). This is almost 4954 // always a no-op, except when the parameter type is bool. In 4955 // that case, this may extend the argument from 1 bit to 8 bits. 4956 QualType IntegerType = ParamType; 4957 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 4958 IntegerType = Enum->getDecl()->getIntegerType(); 4959 Value = Value.extOrTrunc(Context.getTypeSize(IntegerType)); 4960 4961 Converted = TemplateArgument(Context, Value, 4962 Context.getCanonicalType(ParamType)); 4963 return ArgResult; 4964 } 4965 4966 ExprResult ArgResult = DefaultLvalueConversion(Arg); 4967 if (ArgResult.isInvalid()) 4968 return ExprError(); 4969 Arg = ArgResult.get(); 4970 4971 QualType ArgType = Arg->getType(); 4972 4973 // C++ [temp.arg.nontype]p1: 4974 // A template-argument for a non-type, non-template 4975 // template-parameter shall be one of: 4976 // 4977 // -- an integral constant-expression of integral or enumeration 4978 // type; or 4979 // -- the name of a non-type template-parameter; or 4980 SourceLocation NonConstantLoc; 4981 llvm::APSInt Value; 4982 if (!ArgType->isIntegralOrEnumerationType()) { 4983 Diag(Arg->getLocStart(), 4984 diag::err_template_arg_not_integral_or_enumeral) 4985 << ArgType << Arg->getSourceRange(); 4986 Diag(Param->getLocation(), diag::note_template_param_here); 4987 return ExprError(); 4988 } else if (!Arg->isValueDependent()) { 4989 class TmplArgICEDiagnoser : public VerifyICEDiagnoser { 4990 QualType T; 4991 4992 public: 4993 TmplArgICEDiagnoser(QualType T) : T(T) { } 4994 4995 void diagnoseNotICE(Sema &S, SourceLocation Loc, 4996 SourceRange SR) override { 4997 S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR; 4998 } 4999 } Diagnoser(ArgType); 5000 5001 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser, 5002 false).get(); 5003 if (!Arg) 5004 return ExprError(); 5005 } 5006 5007 // From here on out, all we care about is the unqualified form 5008 // of the argument type. 5009 ArgType = ArgType.getUnqualifiedType(); 5010 5011 // Try to convert the argument to the parameter's type. 5012 if (Context.hasSameType(ParamType, ArgType)) { 5013 // Okay: no conversion necessary 5014 } else if (ParamType->isBooleanType()) { 5015 // This is an integral-to-boolean conversion. 5016 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get(); 5017 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || 5018 !ParamType->isEnumeralType()) { 5019 // This is an integral promotion or conversion. 5020 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get(); 5021 } else { 5022 // We can't perform this conversion. 5023 Diag(Arg->getLocStart(), 5024 diag::err_template_arg_not_convertible) 5025 << Arg->getType() << ParamType << Arg->getSourceRange(); 5026 Diag(Param->getLocation(), diag::note_template_param_here); 5027 return ExprError(); 5028 } 5029 5030 // Add the value of this argument to the list of converted 5031 // arguments. We use the bitwidth and signedness of the template 5032 // parameter. 5033 if (Arg->isValueDependent()) { 5034 // The argument is value-dependent. Create a new 5035 // TemplateArgument with the converted expression. 5036 Converted = TemplateArgument(Arg); 5037 return Arg; 5038 } 5039 5040 QualType IntegerType = Context.getCanonicalType(ParamType); 5041 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 5042 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); 5043 5044 if (ParamType->isBooleanType()) { 5045 // Value must be zero or one. 5046 Value = Value != 0; 5047 unsigned AllowedBits = Context.getTypeSize(IntegerType); 5048 if (Value.getBitWidth() != AllowedBits) 5049 Value = Value.extOrTrunc(AllowedBits); 5050 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType()); 5051 } else { 5052 llvm::APSInt OldValue = Value; 5053 5054 // Coerce the template argument's value to the value it will have 5055 // based on the template parameter's type. 5056 unsigned AllowedBits = Context.getTypeSize(IntegerType); 5057 if (Value.getBitWidth() != AllowedBits) 5058 Value = Value.extOrTrunc(AllowedBits); 5059 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType()); 5060 5061 // Complain if an unsigned parameter received a negative value. 5062 if (IntegerType->isUnsignedIntegerOrEnumerationType() 5063 && (OldValue.isSigned() && OldValue.isNegative())) { 5064 Diag(Arg->getLocStart(), diag::warn_template_arg_negative) 5065 << OldValue.toString(10) << Value.toString(10) << Param->getType() 5066 << Arg->getSourceRange(); 5067 Diag(Param->getLocation(), diag::note_template_param_here); 5068 } 5069 5070 // Complain if we overflowed the template parameter's type. 5071 unsigned RequiredBits; 5072 if (IntegerType->isUnsignedIntegerOrEnumerationType()) 5073 RequiredBits = OldValue.getActiveBits(); 5074 else if (OldValue.isUnsigned()) 5075 RequiredBits = OldValue.getActiveBits() + 1; 5076 else 5077 RequiredBits = OldValue.getMinSignedBits(); 5078 if (RequiredBits > AllowedBits) { 5079 Diag(Arg->getLocStart(), 5080 diag::warn_template_arg_too_large) 5081 << OldValue.toString(10) << Value.toString(10) << Param->getType() 5082 << Arg->getSourceRange(); 5083 Diag(Param->getLocation(), diag::note_template_param_here); 5084 } 5085 } 5086 5087 Converted = TemplateArgument(Context, Value, 5088 ParamType->isEnumeralType() 5089 ? Context.getCanonicalType(ParamType) 5090 : IntegerType); 5091 return Arg; 5092 } 5093 5094 QualType ArgType = Arg->getType(); 5095 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction 5096 5097 // Handle pointer-to-function, reference-to-function, and 5098 // pointer-to-member-function all in (roughly) the same way. 5099 if (// -- For a non-type template-parameter of type pointer to 5100 // function, only the function-to-pointer conversion (4.3) is 5101 // applied. If the template-argument represents a set of 5102 // overloaded functions (or a pointer to such), the matching 5103 // function is selected from the set (13.4). 5104 (ParamType->isPointerType() && 5105 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) || 5106 // -- For a non-type template-parameter of type reference to 5107 // function, no conversions apply. If the template-argument 5108 // represents a set of overloaded functions, the matching 5109 // function is selected from the set (13.4). 5110 (ParamType->isReferenceType() && 5111 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) || 5112 // -- For a non-type template-parameter of type pointer to 5113 // member function, no conversions apply. If the 5114 // template-argument represents a set of overloaded member 5115 // functions, the matching member function is selected from 5116 // the set (13.4). 5117 (ParamType->isMemberPointerType() && 5118 ParamType->getAs<MemberPointerType>()->getPointeeType() 5119 ->isFunctionType())) { 5120 5121 if (Arg->getType() == Context.OverloadTy) { 5122 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 5123 true, 5124 FoundResult)) { 5125 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart())) 5126 return ExprError(); 5127 5128 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 5129 ArgType = Arg->getType(); 5130 } else 5131 return ExprError(); 5132 } 5133 5134 if (!ParamType->isMemberPointerType()) { 5135 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 5136 ParamType, 5137 Arg, Converted)) 5138 return ExprError(); 5139 return Arg; 5140 } 5141 5142 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg, 5143 Converted)) 5144 return ExprError(); 5145 return Arg; 5146 } 5147 5148 if (ParamType->isPointerType()) { 5149 // -- for a non-type template-parameter of type pointer to 5150 // object, qualification conversions (4.4) and the 5151 // array-to-pointer conversion (4.2) are applied. 5152 // C++0x also allows a value of std::nullptr_t. 5153 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() && 5154 "Only object pointers allowed here"); 5155 5156 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 5157 ParamType, 5158 Arg, Converted)) 5159 return ExprError(); 5160 return Arg; 5161 } 5162 5163 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { 5164 // -- For a non-type template-parameter of type reference to 5165 // object, no conversions apply. The type referred to by the 5166 // reference may be more cv-qualified than the (otherwise 5167 // identical) type of the template-argument. The 5168 // template-parameter is bound directly to the 5169 // template-argument, which must be an lvalue. 5170 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() && 5171 "Only object references allowed here"); 5172 5173 if (Arg->getType() == Context.OverloadTy) { 5174 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 5175 ParamRefType->getPointeeType(), 5176 true, 5177 FoundResult)) { 5178 if (DiagnoseUseOfDecl(Fn, Arg->getLocStart())) 5179 return ExprError(); 5180 5181 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 5182 ArgType = Arg->getType(); 5183 } else 5184 return ExprError(); 5185 } 5186 5187 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 5188 ParamType, 5189 Arg, Converted)) 5190 return ExprError(); 5191 return Arg; 5192 } 5193 5194 // Deal with parameters of type std::nullptr_t. 5195 if (ParamType->isNullPtrType()) { 5196 if (Arg->isTypeDependent() || Arg->isValueDependent()) { 5197 Converted = TemplateArgument(Arg); 5198 return Arg; 5199 } 5200 5201 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) { 5202 case NPV_NotNullPointer: 5203 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible) 5204 << Arg->getType() << ParamType; 5205 Diag(Param->getLocation(), diag::note_template_param_here); 5206 return ExprError(); 5207 5208 case NPV_Error: 5209 return ExprError(); 5210 5211 case NPV_NullPointer: 5212 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); 5213 Converted = TemplateArgument(Context.getCanonicalType(ParamType), 5214 /*isNullPtr*/true); 5215 return Arg; 5216 } 5217 } 5218 5219 // -- For a non-type template-parameter of type pointer to data 5220 // member, qualification conversions (4.4) are applied. 5221 assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); 5222 5223 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg, 5224 Converted)) 5225 return ExprError(); 5226 return Arg; 5227 } 5228 5229 /// \brief Check a template argument against its corresponding 5230 /// template template parameter. 5231 /// 5232 /// This routine implements the semantics of C++ [temp.arg.template]. 5233 /// It returns true if an error occurred, and false otherwise. 5234 bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, 5235 TemplateArgumentLoc &Arg, 5236 unsigned ArgumentPackIndex) { 5237 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern(); 5238 TemplateDecl *Template = Name.getAsTemplateDecl(); 5239 if (!Template) { 5240 // Any dependent template name is fine. 5241 assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); 5242 return false; 5243 } 5244 5245 // C++0x [temp.arg.template]p1: 5246 // A template-argument for a template template-parameter shall be 5247 // the name of a class template or an alias template, expressed as an 5248 // id-expression. When the template-argument names a class template, only 5249 // primary class templates are considered when matching the 5250 // template template argument with the corresponding parameter; 5251 // partial specializations are not considered even if their 5252 // parameter lists match that of the template template parameter. 5253 // 5254 // Note that we also allow template template parameters here, which 5255 // will happen when we are dealing with, e.g., class template 5256 // partial specializations. 5257 if (!isa<ClassTemplateDecl>(Template) && 5258 !isa<TemplateTemplateParmDecl>(Template) && 5259 !isa<TypeAliasTemplateDecl>(Template)) { 5260 assert(isa<FunctionTemplateDecl>(Template) && 5261 "Only function templates are possible here"); 5262 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); 5263 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) 5264 << Template; 5265 } 5266 5267 TemplateParameterList *Params = Param->getTemplateParameters(); 5268 if (Param->isExpandedParameterPack()) 5269 Params = Param->getExpansionTemplateParameters(ArgumentPackIndex); 5270 5271 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), 5272 Params, 5273 true, 5274 TPL_TemplateTemplateArgumentMatch, 5275 Arg.getLocation()); 5276 } 5277 5278 /// \brief Given a non-type template argument that refers to a 5279 /// declaration and the type of its corresponding non-type template 5280 /// parameter, produce an expression that properly refers to that 5281 /// declaration. 5282 ExprResult 5283 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg, 5284 QualType ParamType, 5285 SourceLocation Loc) { 5286 // C++ [temp.param]p8: 5287 // 5288 // A non-type template-parameter of type "array of T" or 5289 // "function returning T" is adjusted to be of type "pointer to 5290 // T" or "pointer to function returning T", respectively. 5291 if (ParamType->isArrayType()) 5292 ParamType = Context.getArrayDecayedType(ParamType); 5293 else if (ParamType->isFunctionType()) 5294 ParamType = Context.getPointerType(ParamType); 5295 5296 // For a NULL non-type template argument, return nullptr casted to the 5297 // parameter's type. 5298 if (Arg.getKind() == TemplateArgument::NullPtr) { 5299 return ImpCastExprToType( 5300 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc), 5301 ParamType, 5302 ParamType->getAs<MemberPointerType>() 5303 ? CK_NullToMemberPointer 5304 : CK_NullToPointer); 5305 } 5306 assert(Arg.getKind() == TemplateArgument::Declaration && 5307 "Only declaration template arguments permitted here"); 5308 5309 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl()); 5310 5311 if (VD->getDeclContext()->isRecord() && 5312 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) || 5313 isa<IndirectFieldDecl>(VD))) { 5314 // If the value is a class member, we might have a pointer-to-member. 5315 // Determine whether the non-type template template parameter is of 5316 // pointer-to-member type. If so, we need to build an appropriate 5317 // expression for a pointer-to-member, since a "normal" DeclRefExpr 5318 // would refer to the member itself. 5319 if (ParamType->isMemberPointerType()) { 5320 QualType ClassType 5321 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext())); 5322 NestedNameSpecifier *Qualifier 5323 = NestedNameSpecifier::Create(Context, nullptr, false, 5324 ClassType.getTypePtr()); 5325 CXXScopeSpec SS; 5326 SS.MakeTrivial(Context, Qualifier, Loc); 5327 5328 // The actual value-ness of this is unimportant, but for 5329 // internal consistency's sake, references to instance methods 5330 // are r-values. 5331 ExprValueKind VK = VK_LValue; 5332 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance()) 5333 VK = VK_RValue; 5334 5335 ExprResult RefExpr = BuildDeclRefExpr(VD, 5336 VD->getType().getNonReferenceType(), 5337 VK, 5338 Loc, 5339 &SS); 5340 if (RefExpr.isInvalid()) 5341 return ExprError(); 5342 5343 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 5344 5345 // We might need to perform a trailing qualification conversion, since 5346 // the element type on the parameter could be more qualified than the 5347 // element type in the expression we constructed. 5348 bool ObjCLifetimeConversion; 5349 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(), 5350 ParamType.getUnqualifiedType(), false, 5351 ObjCLifetimeConversion)) 5352 RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp); 5353 5354 assert(!RefExpr.isInvalid() && 5355 Context.hasSameType(((Expr*) RefExpr.get())->getType(), 5356 ParamType.getUnqualifiedType())); 5357 return RefExpr; 5358 } 5359 } 5360 5361 QualType T = VD->getType().getNonReferenceType(); 5362 5363 if (ParamType->isPointerType()) { 5364 // When the non-type template parameter is a pointer, take the 5365 // address of the declaration. 5366 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc); 5367 if (RefExpr.isInvalid()) 5368 return ExprError(); 5369 5370 if (T->isFunctionType() || T->isArrayType()) { 5371 // Decay functions and arrays. 5372 RefExpr = DefaultFunctionArrayConversion(RefExpr.get()); 5373 if (RefExpr.isInvalid()) 5374 return ExprError(); 5375 5376 return RefExpr; 5377 } 5378 5379 // Take the address of everything else 5380 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 5381 } 5382 5383 ExprValueKind VK = VK_RValue; 5384 5385 // If the non-type template parameter has reference type, qualify the 5386 // resulting declaration reference with the extra qualifiers on the 5387 // type that the reference refers to. 5388 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) { 5389 VK = VK_LValue; 5390 T = Context.getQualifiedType(T, 5391 TargetRef->getPointeeType().getQualifiers()); 5392 } else if (isa<FunctionDecl>(VD)) { 5393 // References to functions are always lvalues. 5394 VK = VK_LValue; 5395 } 5396 5397 return BuildDeclRefExpr(VD, T, VK, Loc); 5398 } 5399 5400 /// \brief Construct a new expression that refers to the given 5401 /// integral template argument with the given source-location 5402 /// information. 5403 /// 5404 /// This routine takes care of the mapping from an integral template 5405 /// argument (which may have any integral type) to the appropriate 5406 /// literal value. 5407 ExprResult 5408 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg, 5409 SourceLocation Loc) { 5410 assert(Arg.getKind() == TemplateArgument::Integral && 5411 "Operation is only valid for integral template arguments"); 5412 QualType OrigT = Arg.getIntegralType(); 5413 5414 // If this is an enum type that we're instantiating, we need to use an integer 5415 // type the same size as the enumerator. We don't want to build an 5416 // IntegerLiteral with enum type. The integer type of an enum type can be of 5417 // any integral type with C++11 enum classes, make sure we create the right 5418 // type of literal for it. 5419 QualType T = OrigT; 5420 if (const EnumType *ET = OrigT->getAs<EnumType>()) 5421 T = ET->getDecl()->getIntegerType(); 5422 5423 Expr *E; 5424 if (T->isAnyCharacterType()) { 5425 CharacterLiteral::CharacterKind Kind; 5426 if (T->isWideCharType()) 5427 Kind = CharacterLiteral::Wide; 5428 else if (T->isChar16Type()) 5429 Kind = CharacterLiteral::UTF16; 5430 else if (T->isChar32Type()) 5431 Kind = CharacterLiteral::UTF32; 5432 else 5433 Kind = CharacterLiteral::Ascii; 5434 5435 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(), 5436 Kind, T, Loc); 5437 } else if (T->isBooleanType()) { 5438 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(), 5439 T, Loc); 5440 } else if (T->isNullPtrType()) { 5441 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); 5442 } else { 5443 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc); 5444 } 5445 5446 if (OrigT->isEnumeralType()) { 5447 // FIXME: This is a hack. We need a better way to handle substituted 5448 // non-type template parameters. 5449 E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E, 5450 nullptr, 5451 Context.getTrivialTypeSourceInfo(OrigT, Loc), 5452 Loc, Loc); 5453 } 5454 5455 return E; 5456 } 5457 5458 /// \brief Match two template parameters within template parameter lists. 5459 static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old, 5460 bool Complain, 5461 Sema::TemplateParameterListEqualKind Kind, 5462 SourceLocation TemplateArgLoc) { 5463 // Check the actual kind (type, non-type, template). 5464 if (Old->getKind() != New->getKind()) { 5465 if (Complain) { 5466 unsigned NextDiag = diag::err_template_param_different_kind; 5467 if (TemplateArgLoc.isValid()) { 5468 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 5469 NextDiag = diag::note_template_param_different_kind; 5470 } 5471 S.Diag(New->getLocation(), NextDiag) 5472 << (Kind != Sema::TPL_TemplateMatch); 5473 S.Diag(Old->getLocation(), diag::note_template_prev_declaration) 5474 << (Kind != Sema::TPL_TemplateMatch); 5475 } 5476 5477 return false; 5478 } 5479 5480 // Check that both are parameter packs are neither are parameter packs. 5481 // However, if we are matching a template template argument to a 5482 // template template parameter, the template template parameter can have 5483 // a parameter pack where the template template argument does not. 5484 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() && 5485 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch && 5486 Old->isTemplateParameterPack())) { 5487 if (Complain) { 5488 unsigned NextDiag = diag::err_template_parameter_pack_non_pack; 5489 if (TemplateArgLoc.isValid()) { 5490 S.Diag(TemplateArgLoc, 5491 diag::err_template_arg_template_params_mismatch); 5492 NextDiag = diag::note_template_parameter_pack_non_pack; 5493 } 5494 5495 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0 5496 : isa<NonTypeTemplateParmDecl>(New)? 1 5497 : 2; 5498 S.Diag(New->getLocation(), NextDiag) 5499 << ParamKind << New->isParameterPack(); 5500 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here) 5501 << ParamKind << Old->isParameterPack(); 5502 } 5503 5504 return false; 5505 } 5506 5507 // For non-type template parameters, check the type of the parameter. 5508 if (NonTypeTemplateParmDecl *OldNTTP 5509 = dyn_cast<NonTypeTemplateParmDecl>(Old)) { 5510 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New); 5511 5512 // If we are matching a template template argument to a template 5513 // template parameter and one of the non-type template parameter types 5514 // is dependent, then we must wait until template instantiation time 5515 // to actually compare the arguments. 5516 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch && 5517 (OldNTTP->getType()->isDependentType() || 5518 NewNTTP->getType()->isDependentType())) 5519 return true; 5520 5521 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) { 5522 if (Complain) { 5523 unsigned NextDiag = diag::err_template_nontype_parm_different_type; 5524 if (TemplateArgLoc.isValid()) { 5525 S.Diag(TemplateArgLoc, 5526 diag::err_template_arg_template_params_mismatch); 5527 NextDiag = diag::note_template_nontype_parm_different_type; 5528 } 5529 S.Diag(NewNTTP->getLocation(), NextDiag) 5530 << NewNTTP->getType() 5531 << (Kind != Sema::TPL_TemplateMatch); 5532 S.Diag(OldNTTP->getLocation(), 5533 diag::note_template_nontype_parm_prev_declaration) 5534 << OldNTTP->getType(); 5535 } 5536 5537 return false; 5538 } 5539 5540 return true; 5541 } 5542 5543 // For template template parameters, check the template parameter types. 5544 // The template parameter lists of template template 5545 // parameters must agree. 5546 if (TemplateTemplateParmDecl *OldTTP 5547 = dyn_cast<TemplateTemplateParmDecl>(Old)) { 5548 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New); 5549 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), 5550 OldTTP->getTemplateParameters(), 5551 Complain, 5552 (Kind == Sema::TPL_TemplateMatch 5553 ? Sema::TPL_TemplateTemplateParmMatch 5554 : Kind), 5555 TemplateArgLoc); 5556 } 5557 5558 return true; 5559 } 5560 5561 /// \brief Diagnose a known arity mismatch when comparing template argument 5562 /// lists. 5563 static 5564 void DiagnoseTemplateParameterListArityMismatch(Sema &S, 5565 TemplateParameterList *New, 5566 TemplateParameterList *Old, 5567 Sema::TemplateParameterListEqualKind Kind, 5568 SourceLocation TemplateArgLoc) { 5569 unsigned NextDiag = diag::err_template_param_list_different_arity; 5570 if (TemplateArgLoc.isValid()) { 5571 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 5572 NextDiag = diag::note_template_param_list_different_arity; 5573 } 5574 S.Diag(New->getTemplateLoc(), NextDiag) 5575 << (New->size() > Old->size()) 5576 << (Kind != Sema::TPL_TemplateMatch) 5577 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); 5578 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) 5579 << (Kind != Sema::TPL_TemplateMatch) 5580 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); 5581 } 5582 5583 /// \brief Determine whether the given template parameter lists are 5584 /// equivalent. 5585 /// 5586 /// \param New The new template parameter list, typically written in the 5587 /// source code as part of a new template declaration. 5588 /// 5589 /// \param Old The old template parameter list, typically found via 5590 /// name lookup of the template declared with this template parameter 5591 /// list. 5592 /// 5593 /// \param Complain If true, this routine will produce a diagnostic if 5594 /// the template parameter lists are not equivalent. 5595 /// 5596 /// \param Kind describes how we are to match the template parameter lists. 5597 /// 5598 /// \param TemplateArgLoc If this source location is valid, then we 5599 /// are actually checking the template parameter list of a template 5600 /// argument (New) against the template parameter list of its 5601 /// corresponding template template parameter (Old). We produce 5602 /// slightly different diagnostics in this scenario. 5603 /// 5604 /// \returns True if the template parameter lists are equal, false 5605 /// otherwise. 5606 bool 5607 Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, 5608 TemplateParameterList *Old, 5609 bool Complain, 5610 TemplateParameterListEqualKind Kind, 5611 SourceLocation TemplateArgLoc) { 5612 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) { 5613 if (Complain) 5614 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 5615 TemplateArgLoc); 5616 5617 return false; 5618 } 5619 5620 // C++0x [temp.arg.template]p3: 5621 // A template-argument matches a template template-parameter (call it P) 5622 // when each of the template parameters in the template-parameter-list of 5623 // the template-argument's corresponding class template or alias template 5624 // (call it A) matches the corresponding template parameter in the 5625 // template-parameter-list of P. [...] 5626 TemplateParameterList::iterator NewParm = New->begin(); 5627 TemplateParameterList::iterator NewParmEnd = New->end(); 5628 for (TemplateParameterList::iterator OldParm = Old->begin(), 5629 OldParmEnd = Old->end(); 5630 OldParm != OldParmEnd; ++OldParm) { 5631 if (Kind != TPL_TemplateTemplateArgumentMatch || 5632 !(*OldParm)->isTemplateParameterPack()) { 5633 if (NewParm == NewParmEnd) { 5634 if (Complain) 5635 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 5636 TemplateArgLoc); 5637 5638 return false; 5639 } 5640 5641 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, 5642 Kind, TemplateArgLoc)) 5643 return false; 5644 5645 ++NewParm; 5646 continue; 5647 } 5648 5649 // C++0x [temp.arg.template]p3: 5650 // [...] When P's template- parameter-list contains a template parameter 5651 // pack (14.5.3), the template parameter pack will match zero or more 5652 // template parameters or template parameter packs in the 5653 // template-parameter-list of A with the same type and form as the 5654 // template parameter pack in P (ignoring whether those template 5655 // parameters are template parameter packs). 5656 for (; NewParm != NewParmEnd; ++NewParm) { 5657 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, 5658 Kind, TemplateArgLoc)) 5659 return false; 5660 } 5661 } 5662 5663 // Make sure we exhausted all of the arguments. 5664 if (NewParm != NewParmEnd) { 5665 if (Complain) 5666 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 5667 TemplateArgLoc); 5668 5669 return false; 5670 } 5671 5672 return true; 5673 } 5674 5675 /// \brief Check whether a template can be declared within this scope. 5676 /// 5677 /// If the template declaration is valid in this scope, returns 5678 /// false. Otherwise, issues a diagnostic and returns true. 5679 bool 5680 Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { 5681 if (!S) 5682 return false; 5683 5684 // Find the nearest enclosing declaration scope. 5685 while ((S->getFlags() & Scope::DeclScope) == 0 || 5686 (S->getFlags() & Scope::TemplateParamScope) != 0) 5687 S = S->getParent(); 5688 5689 // C++ [temp]p4: 5690 // A template [...] shall not have C linkage. 5691 DeclContext *Ctx = S->getEntity(); 5692 if (Ctx && Ctx->isExternCContext()) 5693 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) 5694 << TemplateParams->getSourceRange(); 5695 5696 while (Ctx && isa<LinkageSpecDecl>(Ctx)) 5697 Ctx = Ctx->getParent(); 5698 5699 // C++ [temp]p2: 5700 // A template-declaration can appear only as a namespace scope or 5701 // class scope declaration. 5702 if (Ctx) { 5703 if (Ctx->isFileContext()) 5704 return false; 5705 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) { 5706 // C++ [temp.mem]p2: 5707 // A local class shall not have member templates. 5708 if (RD->isLocalClass()) 5709 return Diag(TemplateParams->getTemplateLoc(), 5710 diag::err_template_inside_local_class) 5711 << TemplateParams->getSourceRange(); 5712 else 5713 return false; 5714 } 5715 } 5716 5717 return Diag(TemplateParams->getTemplateLoc(), 5718 diag::err_template_outside_namespace_or_class_scope) 5719 << TemplateParams->getSourceRange(); 5720 } 5721 5722 /// \brief Determine what kind of template specialization the given declaration 5723 /// is. 5724 static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) { 5725 if (!D) 5726 return TSK_Undeclared; 5727 5728 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) 5729 return Record->getTemplateSpecializationKind(); 5730 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) 5731 return Function->getTemplateSpecializationKind(); 5732 if (VarDecl *Var = dyn_cast<VarDecl>(D)) 5733 return Var->getTemplateSpecializationKind(); 5734 5735 return TSK_Undeclared; 5736 } 5737 5738 /// \brief Check whether a specialization is well-formed in the current 5739 /// context. 5740 /// 5741 /// This routine determines whether a template specialization can be declared 5742 /// in the current context (C++ [temp.expl.spec]p2). 5743 /// 5744 /// \param S the semantic analysis object for which this check is being 5745 /// performed. 5746 /// 5747 /// \param Specialized the entity being specialized or instantiated, which 5748 /// may be a kind of template (class template, function template, etc.) or 5749 /// a member of a class template (member function, static data member, 5750 /// member class). 5751 /// 5752 /// \param PrevDecl the previous declaration of this entity, if any. 5753 /// 5754 /// \param Loc the location of the explicit specialization or instantiation of 5755 /// this entity. 5756 /// 5757 /// \param IsPartialSpecialization whether this is a partial specialization of 5758 /// a class template. 5759 /// 5760 /// \returns true if there was an error that we cannot recover from, false 5761 /// otherwise. 5762 static bool CheckTemplateSpecializationScope(Sema &S, 5763 NamedDecl *Specialized, 5764 NamedDecl *PrevDecl, 5765 SourceLocation Loc, 5766 bool IsPartialSpecialization) { 5767 // Keep these "kind" numbers in sync with the %select statements in the 5768 // various diagnostics emitted by this routine. 5769 int EntityKind = 0; 5770 if (isa<ClassTemplateDecl>(Specialized)) 5771 EntityKind = IsPartialSpecialization? 1 : 0; 5772 else if (isa<VarTemplateDecl>(Specialized)) 5773 EntityKind = IsPartialSpecialization ? 3 : 2; 5774 else if (isa<FunctionTemplateDecl>(Specialized)) 5775 EntityKind = 4; 5776 else if (isa<CXXMethodDecl>(Specialized)) 5777 EntityKind = 5; 5778 else if (isa<VarDecl>(Specialized)) 5779 EntityKind = 6; 5780 else if (isa<RecordDecl>(Specialized)) 5781 EntityKind = 7; 5782 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11) 5783 EntityKind = 8; 5784 else { 5785 S.Diag(Loc, diag::err_template_spec_unknown_kind) 5786 << S.getLangOpts().CPlusPlus11; 5787 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 5788 return true; 5789 } 5790 5791 // C++ [temp.expl.spec]p2: 5792 // An explicit specialization shall be declared in the namespace 5793 // of which the template is a member, or, for member templates, in 5794 // the namespace of which the enclosing class or enclosing class 5795 // template is a member. An explicit specialization of a member 5796 // function, member class or static data member of a class 5797 // template shall be declared in the namespace of which the class 5798 // template is a member. Such a declaration may also be a 5799 // definition. If the declaration is not a definition, the 5800 // specialization may be defined later in the name- space in which 5801 // the explicit specialization was declared, or in a namespace 5802 // that encloses the one in which the explicit specialization was 5803 // declared. 5804 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) { 5805 S.Diag(Loc, diag::err_template_spec_decl_function_scope) 5806 << Specialized; 5807 return true; 5808 } 5809 5810 if (S.CurContext->isRecord() && !IsPartialSpecialization) { 5811 if (S.getLangOpts().MicrosoftExt) { 5812 // Do not warn for class scope explicit specialization during 5813 // instantiation, warning was already emitted during pattern 5814 // semantic analysis. 5815 if (!S.ActiveTemplateInstantiations.size()) 5816 S.Diag(Loc, diag::ext_function_specialization_in_class) 5817 << Specialized; 5818 } else { 5819 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 5820 << Specialized; 5821 return true; 5822 } 5823 } 5824 5825 if (S.CurContext->isRecord() && 5826 !S.CurContext->Equals(Specialized->getDeclContext())) { 5827 // Make sure that we're specializing in the right record context. 5828 // Otherwise, things can go horribly wrong. 5829 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 5830 << Specialized; 5831 return true; 5832 } 5833 5834 // C++ [temp.class.spec]p6: 5835 // A class template partial specialization may be declared or redeclared 5836 // in any namespace scope in which its definition may be defined (14.5.1 5837 // and 14.5.2). 5838 DeclContext *SpecializedContext 5839 = Specialized->getDeclContext()->getEnclosingNamespaceContext(); 5840 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); 5841 5842 // Make sure that this redeclaration (or definition) occurs in an enclosing 5843 // namespace. 5844 // Note that HandleDeclarator() performs this check for explicit 5845 // specializations of function templates, static data members, and member 5846 // functions, so we skip the check here for those kinds of entities. 5847 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. 5848 // Should we refactor that check, so that it occurs later? 5849 if (!DC->Encloses(SpecializedContext) && 5850 !(isa<FunctionTemplateDecl>(Specialized) || 5851 isa<FunctionDecl>(Specialized) || 5852 isa<VarTemplateDecl>(Specialized) || 5853 isa<VarDecl>(Specialized))) { 5854 if (isa<TranslationUnitDecl>(SpecializedContext)) 5855 S.Diag(Loc, diag::err_template_spec_redecl_global_scope) 5856 << EntityKind << Specialized; 5857 else if (isa<NamespaceDecl>(SpecializedContext)) { 5858 int Diag = diag::err_template_spec_redecl_out_of_scope; 5859 if (S.getLangOpts().MicrosoftExt) 5860 Diag = diag::ext_ms_template_spec_redecl_out_of_scope; 5861 S.Diag(Loc, Diag) << EntityKind << Specialized 5862 << cast<NamedDecl>(SpecializedContext); 5863 } else 5864 llvm_unreachable("unexpected namespace context for specialization"); 5865 5866 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 5867 } else if ((!PrevDecl || 5868 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || 5869 getTemplateSpecializationKind(PrevDecl) == 5870 TSK_ImplicitInstantiation)) { 5871 // C++ [temp.exp.spec]p2: 5872 // An explicit specialization shall be declared in the namespace of which 5873 // the template is a member, or, for member templates, in the namespace 5874 // of which the enclosing class or enclosing class template is a member. 5875 // An explicit specialization of a member function, member class or 5876 // static data member of a class template shall be declared in the 5877 // namespace of which the class template is a member. 5878 // 5879 // C++11 [temp.expl.spec]p2: 5880 // An explicit specialization shall be declared in a namespace enclosing 5881 // the specialized template. 5882 // C++11 [temp.explicit]p3: 5883 // An explicit instantiation shall appear in an enclosing namespace of its 5884 // template. 5885 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) { 5886 bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext); 5887 if (isa<TranslationUnitDecl>(SpecializedContext)) { 5888 assert(!IsCPlusPlus11Extension && 5889 "DC encloses TU but isn't in enclosing namespace set"); 5890 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global) 5891 << EntityKind << Specialized; 5892 } else if (isa<NamespaceDecl>(SpecializedContext)) { 5893 int Diag; 5894 if (!IsCPlusPlus11Extension) 5895 Diag = diag::err_template_spec_decl_out_of_scope; 5896 else if (!S.getLangOpts().CPlusPlus11) 5897 Diag = diag::ext_template_spec_decl_out_of_scope; 5898 else 5899 Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope; 5900 S.Diag(Loc, Diag) 5901 << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext); 5902 } 5903 5904 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 5905 } 5906 } 5907 5908 return false; 5909 } 5910 5911 static SourceRange findTemplateParameter(unsigned Depth, Expr *E) { 5912 if (!E->isInstantiationDependent()) 5913 return SourceLocation(); 5914 DependencyChecker Checker(Depth); 5915 Checker.TraverseStmt(E); 5916 if (Checker.Match && Checker.MatchLoc.isInvalid()) 5917 return E->getSourceRange(); 5918 return Checker.MatchLoc; 5919 } 5920 5921 static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) { 5922 if (!TL.getType()->isDependentType()) 5923 return SourceLocation(); 5924 DependencyChecker Checker(Depth); 5925 Checker.TraverseTypeLoc(TL); 5926 if (Checker.Match && Checker.MatchLoc.isInvalid()) 5927 return TL.getSourceRange(); 5928 return Checker.MatchLoc; 5929 } 5930 5931 /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs 5932 /// that checks non-type template partial specialization arguments. 5933 static bool CheckNonTypeTemplatePartialSpecializationArgs( 5934 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param, 5935 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) { 5936 for (unsigned I = 0; I != NumArgs; ++I) { 5937 if (Args[I].getKind() == TemplateArgument::Pack) { 5938 if (CheckNonTypeTemplatePartialSpecializationArgs( 5939 S, TemplateNameLoc, Param, Args[I].pack_begin(), 5940 Args[I].pack_size(), IsDefaultArgument)) 5941 return true; 5942 5943 continue; 5944 } 5945 5946 if (Args[I].getKind() != TemplateArgument::Expression) 5947 continue; 5948 5949 Expr *ArgExpr = Args[I].getAsExpr(); 5950 5951 // We can have a pack expansion of any of the bullets below. 5952 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr)) 5953 ArgExpr = Expansion->getPattern(); 5954 5955 // Strip off any implicit casts we added as part of type checking. 5956 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr)) 5957 ArgExpr = ICE->getSubExpr(); 5958 5959 // C++ [temp.class.spec]p8: 5960 // A non-type argument is non-specialized if it is the name of a 5961 // non-type parameter. All other non-type arguments are 5962 // specialized. 5963 // 5964 // Below, we check the two conditions that only apply to 5965 // specialized non-type arguments, so skip any non-specialized 5966 // arguments. 5967 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr)) 5968 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl())) 5969 continue; 5970 5971 // C++ [temp.class.spec]p9: 5972 // Within the argument list of a class template partial 5973 // specialization, the following restrictions apply: 5974 // -- A partially specialized non-type argument expression 5975 // shall not involve a template parameter of the partial 5976 // specialization except when the argument expression is a 5977 // simple identifier. 5978 SourceRange ParamUseRange = 5979 findTemplateParameter(Param->getDepth(), ArgExpr); 5980 if (ParamUseRange.isValid()) { 5981 if (IsDefaultArgument) { 5982 S.Diag(TemplateNameLoc, 5983 diag::err_dependent_non_type_arg_in_partial_spec); 5984 S.Diag(ParamUseRange.getBegin(), 5985 diag::note_dependent_non_type_default_arg_in_partial_spec) 5986 << ParamUseRange; 5987 } else { 5988 S.Diag(ParamUseRange.getBegin(), 5989 diag::err_dependent_non_type_arg_in_partial_spec) 5990 << ParamUseRange; 5991 } 5992 return true; 5993 } 5994 5995 // -- The type of a template parameter corresponding to a 5996 // specialized non-type argument shall not be dependent on a 5997 // parameter of the specialization. 5998 // 5999 // FIXME: We need to delay this check until instantiation in some cases: 6000 // 6001 // template<template<typename> class X> struct A { 6002 // template<typename T, X<T> N> struct B; 6003 // template<typename T> struct B<T, 0>; 6004 // }; 6005 // template<typename> using X = int; 6006 // A<X>::B<int, 0> b; 6007 ParamUseRange = findTemplateParameter( 6008 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc()); 6009 if (ParamUseRange.isValid()) { 6010 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getLocStart(), 6011 diag::err_dependent_typed_non_type_arg_in_partial_spec) 6012 << Param->getType() << ParamUseRange; 6013 S.Diag(Param->getLocation(), diag::note_template_param_here) 6014 << (IsDefaultArgument ? ParamUseRange : SourceRange()); 6015 return true; 6016 } 6017 } 6018 6019 return false; 6020 } 6021 6022 /// \brief Check the non-type template arguments of a class template 6023 /// partial specialization according to C++ [temp.class.spec]p9. 6024 /// 6025 /// \param TemplateNameLoc the location of the template name. 6026 /// \param TemplateParams the template parameters of the primary class 6027 /// template. 6028 /// \param NumExplicit the number of explicitly-specified template arguments. 6029 /// \param TemplateArgs the template arguments of the class template 6030 /// partial specialization. 6031 /// 6032 /// \returns \c true if there was an error, \c false otherwise. 6033 static bool CheckTemplatePartialSpecializationArgs( 6034 Sema &S, SourceLocation TemplateNameLoc, 6035 TemplateParameterList *TemplateParams, unsigned NumExplicit, 6036 SmallVectorImpl<TemplateArgument> &TemplateArgs) { 6037 const TemplateArgument *ArgList = TemplateArgs.data(); 6038 6039 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 6040 NonTypeTemplateParmDecl *Param 6041 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I)); 6042 if (!Param) 6043 continue; 6044 6045 if (CheckNonTypeTemplatePartialSpecializationArgs( 6046 S, TemplateNameLoc, Param, &ArgList[I], 1, I >= NumExplicit)) 6047 return true; 6048 } 6049 6050 return false; 6051 } 6052 6053 DeclResult 6054 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, 6055 TagUseKind TUK, 6056 SourceLocation KWLoc, 6057 SourceLocation ModulePrivateLoc, 6058 TemplateIdAnnotation &TemplateId, 6059 AttributeList *Attr, 6060 MultiTemplateParamsArg TemplateParameterLists) { 6061 assert(TUK != TUK_Reference && "References are not specializations"); 6062 6063 CXXScopeSpec &SS = TemplateId.SS; 6064 6065 // NOTE: KWLoc is the location of the tag keyword. This will instead 6066 // store the location of the outermost template keyword in the declaration. 6067 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0 6068 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc; 6069 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc; 6070 SourceLocation LAngleLoc = TemplateId.LAngleLoc; 6071 SourceLocation RAngleLoc = TemplateId.RAngleLoc; 6072 6073 // Find the class template we're specializing 6074 TemplateName Name = TemplateId.Template.get(); 6075 ClassTemplateDecl *ClassTemplate 6076 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl()); 6077 6078 if (!ClassTemplate) { 6079 Diag(TemplateNameLoc, diag::err_not_class_template_specialization) 6080 << (Name.getAsTemplateDecl() && 6081 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())); 6082 return true; 6083 } 6084 6085 bool isExplicitSpecialization = false; 6086 bool isPartialSpecialization = false; 6087 6088 // Check the validity of the template headers that introduce this 6089 // template. 6090 // FIXME: We probably shouldn't complain about these headers for 6091 // friend declarations. 6092 bool Invalid = false; 6093 TemplateParameterList *TemplateParams = 6094 MatchTemplateParametersToScopeSpecifier( 6095 KWLoc, TemplateNameLoc, SS, &TemplateId, 6096 TemplateParameterLists, TUK == TUK_Friend, isExplicitSpecialization, 6097 Invalid); 6098 if (Invalid) 6099 return true; 6100 6101 if (TemplateParams && TemplateParams->size() > 0) { 6102 isPartialSpecialization = true; 6103 6104 if (TUK == TUK_Friend) { 6105 Diag(KWLoc, diag::err_partial_specialization_friend) 6106 << SourceRange(LAngleLoc, RAngleLoc); 6107 return true; 6108 } 6109 6110 // C++ [temp.class.spec]p10: 6111 // The template parameter list of a specialization shall not 6112 // contain default template argument values. 6113 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 6114 Decl *Param = TemplateParams->getParam(I); 6115 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) { 6116 if (TTP->hasDefaultArgument()) { 6117 Diag(TTP->getDefaultArgumentLoc(), 6118 diag::err_default_arg_in_partial_spec); 6119 TTP->removeDefaultArgument(); 6120 } 6121 } else if (NonTypeTemplateParmDecl *NTTP 6122 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 6123 if (Expr *DefArg = NTTP->getDefaultArgument()) { 6124 Diag(NTTP->getDefaultArgumentLoc(), 6125 diag::err_default_arg_in_partial_spec) 6126 << DefArg->getSourceRange(); 6127 NTTP->removeDefaultArgument(); 6128 } 6129 } else { 6130 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param); 6131 if (TTP->hasDefaultArgument()) { 6132 Diag(TTP->getDefaultArgument().getLocation(), 6133 diag::err_default_arg_in_partial_spec) 6134 << TTP->getDefaultArgument().getSourceRange(); 6135 TTP->removeDefaultArgument(); 6136 } 6137 } 6138 } 6139 } else if (TemplateParams) { 6140 if (TUK == TUK_Friend) 6141 Diag(KWLoc, diag::err_template_spec_friend) 6142 << FixItHint::CreateRemoval( 6143 SourceRange(TemplateParams->getTemplateLoc(), 6144 TemplateParams->getRAngleLoc())) 6145 << SourceRange(LAngleLoc, RAngleLoc); 6146 else 6147 isExplicitSpecialization = true; 6148 } else { 6149 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl"); 6150 } 6151 6152 // Check that the specialization uses the same tag kind as the 6153 // original template. 6154 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 6155 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!"); 6156 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 6157 Kind, TUK == TUK_Definition, KWLoc, 6158 *ClassTemplate->getIdentifier())) { 6159 Diag(KWLoc, diag::err_use_with_wrong_tag) 6160 << ClassTemplate 6161 << FixItHint::CreateReplacement(KWLoc, 6162 ClassTemplate->getTemplatedDecl()->getKindName()); 6163 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 6164 diag::note_previous_use); 6165 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 6166 } 6167 6168 // Translate the parser's template argument list in our AST format. 6169 TemplateArgumentListInfo TemplateArgs = 6170 makeTemplateArgumentListInfo(*this, TemplateId); 6171 6172 // Check for unexpanded parameter packs in any of the template arguments. 6173 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 6174 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I], 6175 UPPC_PartialSpecialization)) 6176 return true; 6177 6178 // Check that the template argument list is well-formed for this 6179 // template. 6180 SmallVector<TemplateArgument, 4> Converted; 6181 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 6182 TemplateArgs, false, Converted)) 6183 return true; 6184 6185 // Find the class template (partial) specialization declaration that 6186 // corresponds to these arguments. 6187 if (isPartialSpecialization) { 6188 if (CheckTemplatePartialSpecializationArgs( 6189 *this, TemplateNameLoc, ClassTemplate->getTemplateParameters(), 6190 TemplateArgs.size(), Converted)) 6191 return true; 6192 6193 bool InstantiationDependent; 6194 if (!Name.isDependent() && 6195 !TemplateSpecializationType::anyDependentTemplateArguments( 6196 TemplateArgs.getArgumentArray(), 6197 TemplateArgs.size(), 6198 InstantiationDependent)) { 6199 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) 6200 << ClassTemplate->getDeclName(); 6201 isPartialSpecialization = false; 6202 } 6203 } 6204 6205 void *InsertPos = nullptr; 6206 ClassTemplateSpecializationDecl *PrevDecl = nullptr; 6207 6208 if (isPartialSpecialization) 6209 // FIXME: Template parameter list matters, too 6210 PrevDecl = ClassTemplate->findPartialSpecialization(Converted, InsertPos); 6211 else 6212 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos); 6213 6214 ClassTemplateSpecializationDecl *Specialization = nullptr; 6215 6216 // Check whether we can declare a class template specialization in 6217 // the current scope. 6218 if (TUK != TUK_Friend && 6219 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl, 6220 TemplateNameLoc, 6221 isPartialSpecialization)) 6222 return true; 6223 6224 // The canonical type 6225 QualType CanonType; 6226 if (isPartialSpecialization) { 6227 // Build the canonical type that describes the converted template 6228 // arguments of the class template partial specialization. 6229 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 6230 CanonType = Context.getTemplateSpecializationType(CanonTemplate, 6231 Converted.data(), 6232 Converted.size()); 6233 6234 if (Context.hasSameType(CanonType, 6235 ClassTemplate->getInjectedClassNameSpecialization())) { 6236 // C++ [temp.class.spec]p9b3: 6237 // 6238 // -- The argument list of the specialization shall not be identical 6239 // to the implicit argument list of the primary template. 6240 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 6241 << /*class template*/0 << (TUK == TUK_Definition) 6242 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); 6243 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS, 6244 ClassTemplate->getIdentifier(), 6245 TemplateNameLoc, 6246 Attr, 6247 TemplateParams, 6248 AS_none, /*ModulePrivateLoc=*/SourceLocation(), 6249 /*FriendLoc*/SourceLocation(), 6250 TemplateParameterLists.size() - 1, 6251 TemplateParameterLists.data()); 6252 } 6253 6254 // Create a new class template partial specialization declaration node. 6255 ClassTemplatePartialSpecializationDecl *PrevPartial 6256 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl); 6257 ClassTemplatePartialSpecializationDecl *Partial 6258 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind, 6259 ClassTemplate->getDeclContext(), 6260 KWLoc, TemplateNameLoc, 6261 TemplateParams, 6262 ClassTemplate, 6263 Converted.data(), 6264 Converted.size(), 6265 TemplateArgs, 6266 CanonType, 6267 PrevPartial); 6268 SetNestedNameSpecifier(Partial, SS); 6269 if (TemplateParameterLists.size() > 1 && SS.isSet()) { 6270 Partial->setTemplateParameterListsInfo(Context, 6271 TemplateParameterLists.size() - 1, 6272 TemplateParameterLists.data()); 6273 } 6274 6275 if (!PrevPartial) 6276 ClassTemplate->AddPartialSpecialization(Partial, InsertPos); 6277 Specialization = Partial; 6278 6279 // If we are providing an explicit specialization of a member class 6280 // template specialization, make a note of that. 6281 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 6282 PrevPartial->setMemberSpecialization(); 6283 6284 // Check that all of the template parameters of the class template 6285 // partial specialization are deducible from the template 6286 // arguments. If not, this class template partial specialization 6287 // will never be used. 6288 llvm::SmallBitVector DeducibleParams(TemplateParams->size()); 6289 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 6290 TemplateParams->getDepth(), 6291 DeducibleParams); 6292 6293 if (!DeducibleParams.all()) { 6294 unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count(); 6295 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 6296 << /*class template*/0 << (NumNonDeducible > 1) 6297 << SourceRange(TemplateNameLoc, RAngleLoc); 6298 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 6299 if (!DeducibleParams[I]) { 6300 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 6301 if (Param->getDeclName()) 6302 Diag(Param->getLocation(), 6303 diag::note_partial_spec_unused_parameter) 6304 << Param->getDeclName(); 6305 else 6306 Diag(Param->getLocation(), 6307 diag::note_partial_spec_unused_parameter) 6308 << "(anonymous)"; 6309 } 6310 } 6311 } 6312 } else { 6313 // Create a new class template specialization declaration node for 6314 // this explicit specialization or friend declaration. 6315 Specialization 6316 = ClassTemplateSpecializationDecl::Create(Context, Kind, 6317 ClassTemplate->getDeclContext(), 6318 KWLoc, TemplateNameLoc, 6319 ClassTemplate, 6320 Converted.data(), 6321 Converted.size(), 6322 PrevDecl); 6323 SetNestedNameSpecifier(Specialization, SS); 6324 if (TemplateParameterLists.size() > 0) { 6325 Specialization->setTemplateParameterListsInfo(Context, 6326 TemplateParameterLists.size(), 6327 TemplateParameterLists.data()); 6328 } 6329 6330 if (!PrevDecl) 6331 ClassTemplate->AddSpecialization(Specialization, InsertPos); 6332 6333 CanonType = Context.getTypeDeclType(Specialization); 6334 } 6335 6336 // C++ [temp.expl.spec]p6: 6337 // If a template, a member template or the member of a class template is 6338 // explicitly specialized then that specialization shall be declared 6339 // before the first use of that specialization that would cause an implicit 6340 // instantiation to take place, in every translation unit in which such a 6341 // use occurs; no diagnostic is required. 6342 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 6343 bool Okay = false; 6344 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) { 6345 // Is there any previous explicit specialization declaration? 6346 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 6347 Okay = true; 6348 break; 6349 } 6350 } 6351 6352 if (!Okay) { 6353 SourceRange Range(TemplateNameLoc, RAngleLoc); 6354 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 6355 << Context.getTypeDeclType(Specialization) << Range; 6356 6357 Diag(PrevDecl->getPointOfInstantiation(), 6358 diag::note_instantiation_required_here) 6359 << (PrevDecl->getTemplateSpecializationKind() 6360 != TSK_ImplicitInstantiation); 6361 return true; 6362 } 6363 } 6364 6365 // If this is not a friend, note that this is an explicit specialization. 6366 if (TUK != TUK_Friend) 6367 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 6368 6369 // Check that this isn't a redefinition of this specialization. 6370 if (TUK == TUK_Definition) { 6371 if (RecordDecl *Def = Specialization->getDefinition()) { 6372 SourceRange Range(TemplateNameLoc, RAngleLoc); 6373 Diag(TemplateNameLoc, diag::err_redefinition) 6374 << Context.getTypeDeclType(Specialization) << Range; 6375 Diag(Def->getLocation(), diag::note_previous_definition); 6376 Specialization->setInvalidDecl(); 6377 return true; 6378 } 6379 } 6380 6381 if (Attr) 6382 ProcessDeclAttributeList(S, Specialization, Attr); 6383 6384 // Add alignment attributes if necessary; these attributes are checked when 6385 // the ASTContext lays out the structure. 6386 if (TUK == TUK_Definition) { 6387 AddAlignmentAttributesForRecord(Specialization); 6388 AddMsStructLayoutForRecord(Specialization); 6389 } 6390 6391 if (ModulePrivateLoc.isValid()) 6392 Diag(Specialization->getLocation(), diag::err_module_private_specialization) 6393 << (isPartialSpecialization? 1 : 0) 6394 << FixItHint::CreateRemoval(ModulePrivateLoc); 6395 6396 // Build the fully-sugared type for this class template 6397 // specialization as the user wrote in the specialization 6398 // itself. This means that we'll pretty-print the type retrieved 6399 // from the specialization's declaration the way that the user 6400 // actually wrote the specialization, rather than formatting the 6401 // name based on the "canonical" representation used to store the 6402 // template arguments in the specialization. 6403 TypeSourceInfo *WrittenTy 6404 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 6405 TemplateArgs, CanonType); 6406 if (TUK != TUK_Friend) { 6407 Specialization->setTypeAsWritten(WrittenTy); 6408 Specialization->setTemplateKeywordLoc(TemplateKWLoc); 6409 } 6410 6411 // C++ [temp.expl.spec]p9: 6412 // A template explicit specialization is in the scope of the 6413 // namespace in which the template was defined. 6414 // 6415 // We actually implement this paragraph where we set the semantic 6416 // context (in the creation of the ClassTemplateSpecializationDecl), 6417 // but we also maintain the lexical context where the actual 6418 // definition occurs. 6419 Specialization->setLexicalDeclContext(CurContext); 6420 6421 // We may be starting the definition of this specialization. 6422 if (TUK == TUK_Definition) 6423 Specialization->startDefinition(); 6424 6425 if (TUK == TUK_Friend) { 6426 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 6427 TemplateNameLoc, 6428 WrittenTy, 6429 /*FIXME:*/KWLoc); 6430 Friend->setAccess(AS_public); 6431 CurContext->addDecl(Friend); 6432 } else { 6433 // Add the specialization into its lexical context, so that it can 6434 // be seen when iterating through the list of declarations in that 6435 // context. However, specializations are not found by name lookup. 6436 CurContext->addDecl(Specialization); 6437 } 6438 return Specialization; 6439 } 6440 6441 Decl *Sema::ActOnTemplateDeclarator(Scope *S, 6442 MultiTemplateParamsArg TemplateParameterLists, 6443 Declarator &D) { 6444 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists); 6445 ActOnDocumentableDecl(NewDecl); 6446 return NewDecl; 6447 } 6448 6449 Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope, 6450 MultiTemplateParamsArg TemplateParameterLists, 6451 Declarator &D) { 6452 assert(getCurFunctionDecl() == nullptr && "Function parsing confused"); 6453 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 6454 6455 if (FTI.hasPrototype) { 6456 // FIXME: Diagnose arguments without names in C. 6457 } 6458 6459 Scope *ParentScope = FnBodyScope->getParent(); 6460 6461 D.setFunctionDefinitionKind(FDK_Definition); 6462 Decl *DP = HandleDeclarator(ParentScope, D, 6463 TemplateParameterLists); 6464 return ActOnStartOfFunctionDef(FnBodyScope, DP); 6465 } 6466 6467 /// \brief Strips various properties off an implicit instantiation 6468 /// that has just been explicitly specialized. 6469 static void StripImplicitInstantiation(NamedDecl *D) { 6470 D->dropAttr<DLLImportAttr>(); 6471 D->dropAttr<DLLExportAttr>(); 6472 6473 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 6474 FD->setInlineSpecified(false); 6475 } 6476 6477 /// \brief Compute the diagnostic location for an explicit instantiation 6478 // declaration or definition. 6479 static SourceLocation DiagLocForExplicitInstantiation( 6480 NamedDecl* D, SourceLocation PointOfInstantiation) { 6481 // Explicit instantiations following a specialization have no effect and 6482 // hence no PointOfInstantiation. In that case, walk decl backwards 6483 // until a valid name loc is found. 6484 SourceLocation PrevDiagLoc = PointOfInstantiation; 6485 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid(); 6486 Prev = Prev->getPreviousDecl()) { 6487 PrevDiagLoc = Prev->getLocation(); 6488 } 6489 assert(PrevDiagLoc.isValid() && 6490 "Explicit instantiation without point of instantiation?"); 6491 return PrevDiagLoc; 6492 } 6493 6494 /// \brief Diagnose cases where we have an explicit template specialization 6495 /// before/after an explicit template instantiation, producing diagnostics 6496 /// for those cases where they are required and determining whether the 6497 /// new specialization/instantiation will have any effect. 6498 /// 6499 /// \param NewLoc the location of the new explicit specialization or 6500 /// instantiation. 6501 /// 6502 /// \param NewTSK the kind of the new explicit specialization or instantiation. 6503 /// 6504 /// \param PrevDecl the previous declaration of the entity. 6505 /// 6506 /// \param PrevTSK the kind of the old explicit specialization or instantiatin. 6507 /// 6508 /// \param PrevPointOfInstantiation if valid, indicates where the previus 6509 /// declaration was instantiated (either implicitly or explicitly). 6510 /// 6511 /// \param HasNoEffect will be set to true to indicate that the new 6512 /// specialization or instantiation has no effect and should be ignored. 6513 /// 6514 /// \returns true if there was an error that should prevent the introduction of 6515 /// the new declaration into the AST, false otherwise. 6516 bool 6517 Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc, 6518 TemplateSpecializationKind NewTSK, 6519 NamedDecl *PrevDecl, 6520 TemplateSpecializationKind PrevTSK, 6521 SourceLocation PrevPointOfInstantiation, 6522 bool &HasNoEffect) { 6523 HasNoEffect = false; 6524 6525 switch (NewTSK) { 6526 case TSK_Undeclared: 6527 case TSK_ImplicitInstantiation: 6528 assert( 6529 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) && 6530 "previous declaration must be implicit!"); 6531 return false; 6532 6533 case TSK_ExplicitSpecialization: 6534 switch (PrevTSK) { 6535 case TSK_Undeclared: 6536 case TSK_ExplicitSpecialization: 6537 // Okay, we're just specializing something that is either already 6538 // explicitly specialized or has merely been mentioned without any 6539 // instantiation. 6540 return false; 6541 6542 case TSK_ImplicitInstantiation: 6543 if (PrevPointOfInstantiation.isInvalid()) { 6544 // The declaration itself has not actually been instantiated, so it is 6545 // still okay to specialize it. 6546 StripImplicitInstantiation(PrevDecl); 6547 return false; 6548 } 6549 // Fall through 6550 6551 case TSK_ExplicitInstantiationDeclaration: 6552 case TSK_ExplicitInstantiationDefinition: 6553 assert((PrevTSK == TSK_ImplicitInstantiation || 6554 PrevPointOfInstantiation.isValid()) && 6555 "Explicit instantiation without point of instantiation?"); 6556 6557 // C++ [temp.expl.spec]p6: 6558 // If a template, a member template or the member of a class template 6559 // is explicitly specialized then that specialization shall be declared 6560 // before the first use of that specialization that would cause an 6561 // implicit instantiation to take place, in every translation unit in 6562 // which such a use occurs; no diagnostic is required. 6563 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) { 6564 // Is there any previous explicit specialization declaration? 6565 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) 6566 return false; 6567 } 6568 6569 Diag(NewLoc, diag::err_specialization_after_instantiation) 6570 << PrevDecl; 6571 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here) 6572 << (PrevTSK != TSK_ImplicitInstantiation); 6573 6574 return true; 6575 } 6576 6577 case TSK_ExplicitInstantiationDeclaration: 6578 switch (PrevTSK) { 6579 case TSK_ExplicitInstantiationDeclaration: 6580 // This explicit instantiation declaration is redundant (that's okay). 6581 HasNoEffect = true; 6582 return false; 6583 6584 case TSK_Undeclared: 6585 case TSK_ImplicitInstantiation: 6586 // We're explicitly instantiating something that may have already been 6587 // implicitly instantiated; that's fine. 6588 return false; 6589 6590 case TSK_ExplicitSpecialization: 6591 // C++0x [temp.explicit]p4: 6592 // For a given set of template parameters, if an explicit instantiation 6593 // of a template appears after a declaration of an explicit 6594 // specialization for that template, the explicit instantiation has no 6595 // effect. 6596 HasNoEffect = true; 6597 return false; 6598 6599 case TSK_ExplicitInstantiationDefinition: 6600 // C++0x [temp.explicit]p10: 6601 // If an entity is the subject of both an explicit instantiation 6602 // declaration and an explicit instantiation definition in the same 6603 // translation unit, the definition shall follow the declaration. 6604 Diag(NewLoc, 6605 diag::err_explicit_instantiation_declaration_after_definition); 6606 6607 // Explicit instantiations following a specialization have no effect and 6608 // hence no PrevPointOfInstantiation. In that case, walk decl backwards 6609 // until a valid name loc is found. 6610 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation), 6611 diag::note_explicit_instantiation_definition_here); 6612 HasNoEffect = true; 6613 return false; 6614 } 6615 6616 case TSK_ExplicitInstantiationDefinition: 6617 switch (PrevTSK) { 6618 case TSK_Undeclared: 6619 case TSK_ImplicitInstantiation: 6620 // We're explicitly instantiating something that may have already been 6621 // implicitly instantiated; that's fine. 6622 return false; 6623 6624 case TSK_ExplicitSpecialization: 6625 // C++ DR 259, C++0x [temp.explicit]p4: 6626 // For a given set of template parameters, if an explicit 6627 // instantiation of a template appears after a declaration of 6628 // an explicit specialization for that template, the explicit 6629 // instantiation has no effect. 6630 // 6631 // In C++98/03 mode, we only give an extension warning here, because it 6632 // is not harmful to try to explicitly instantiate something that 6633 // has been explicitly specialized. 6634 Diag(NewLoc, getLangOpts().CPlusPlus11 ? 6635 diag::warn_cxx98_compat_explicit_instantiation_after_specialization : 6636 diag::ext_explicit_instantiation_after_specialization) 6637 << PrevDecl; 6638 Diag(PrevDecl->getLocation(), 6639 diag::note_previous_template_specialization); 6640 HasNoEffect = true; 6641 return false; 6642 6643 case TSK_ExplicitInstantiationDeclaration: 6644 // We're explicity instantiating a definition for something for which we 6645 // were previously asked to suppress instantiations. That's fine. 6646 6647 // C++0x [temp.explicit]p4: 6648 // For a given set of template parameters, if an explicit instantiation 6649 // of a template appears after a declaration of an explicit 6650 // specialization for that template, the explicit instantiation has no 6651 // effect. 6652 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) { 6653 // Is there any previous explicit specialization declaration? 6654 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 6655 HasNoEffect = true; 6656 break; 6657 } 6658 } 6659 6660 return false; 6661 6662 case TSK_ExplicitInstantiationDefinition: 6663 // C++0x [temp.spec]p5: 6664 // For a given template and a given set of template-arguments, 6665 // - an explicit instantiation definition shall appear at most once 6666 // in a program, 6667 6668 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations. 6669 Diag(NewLoc, (getLangOpts().MSVCCompat) 6670 ? diag::ext_explicit_instantiation_duplicate 6671 : diag::err_explicit_instantiation_duplicate) 6672 << PrevDecl; 6673 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation), 6674 diag::note_previous_explicit_instantiation); 6675 HasNoEffect = true; 6676 return false; 6677 } 6678 } 6679 6680 llvm_unreachable("Missing specialization/instantiation case?"); 6681 } 6682 6683 /// \brief Perform semantic analysis for the given dependent function 6684 /// template specialization. 6685 /// 6686 /// The only possible way to get a dependent function template specialization 6687 /// is with a friend declaration, like so: 6688 /// 6689 /// \code 6690 /// template \<class T> void foo(T); 6691 /// template \<class T> class A { 6692 /// friend void foo<>(T); 6693 /// }; 6694 /// \endcode 6695 /// 6696 /// There really isn't any useful analysis we can do here, so we 6697 /// just store the information. 6698 bool 6699 Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD, 6700 const TemplateArgumentListInfo &ExplicitTemplateArgs, 6701 LookupResult &Previous) { 6702 // Remove anything from Previous that isn't a function template in 6703 // the correct context. 6704 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 6705 LookupResult::Filter F = Previous.makeFilter(); 6706 while (F.hasNext()) { 6707 NamedDecl *D = F.next()->getUnderlyingDecl(); 6708 if (!isa<FunctionTemplateDecl>(D) || 6709 !FDLookupContext->InEnclosingNamespaceSetOf( 6710 D->getDeclContext()->getRedeclContext())) 6711 F.erase(); 6712 } 6713 F.done(); 6714 6715 // Should this be diagnosed here? 6716 if (Previous.empty()) return true; 6717 6718 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(), 6719 ExplicitTemplateArgs); 6720 return false; 6721 } 6722 6723 /// \brief Perform semantic analysis for the given function template 6724 /// specialization. 6725 /// 6726 /// This routine performs all of the semantic analysis required for an 6727 /// explicit function template specialization. On successful completion, 6728 /// the function declaration \p FD will become a function template 6729 /// specialization. 6730 /// 6731 /// \param FD the function declaration, which will be updated to become a 6732 /// function template specialization. 6733 /// 6734 /// \param ExplicitTemplateArgs the explicitly-provided template arguments, 6735 /// if any. Note that this may be valid info even when 0 arguments are 6736 /// explicitly provided as in, e.g., \c void sort<>(char*, char*); 6737 /// as it anyway contains info on the angle brackets locations. 6738 /// 6739 /// \param Previous the set of declarations that may be specialized by 6740 /// this function specialization. 6741 bool Sema::CheckFunctionTemplateSpecialization( 6742 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs, 6743 LookupResult &Previous) { 6744 // The set of function template specializations that could match this 6745 // explicit function template specialization. 6746 UnresolvedSet<8> Candidates; 6747 TemplateSpecCandidateSet FailedCandidates(FD->getLocation()); 6748 6749 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 6750 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 6751 I != E; ++I) { 6752 NamedDecl *Ovl = (*I)->getUnderlyingDecl(); 6753 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) { 6754 // Only consider templates found within the same semantic lookup scope as 6755 // FD. 6756 if (!FDLookupContext->InEnclosingNamespaceSetOf( 6757 Ovl->getDeclContext()->getRedeclContext())) 6758 continue; 6759 6760 // When matching a constexpr member function template specialization 6761 // against the primary template, we don't yet know whether the 6762 // specialization has an implicit 'const' (because we don't know whether 6763 // it will be a static member function until we know which template it 6764 // specializes), so adjust it now assuming it specializes this template. 6765 QualType FT = FD->getType(); 6766 if (FD->isConstexpr()) { 6767 CXXMethodDecl *OldMD = 6768 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl()); 6769 if (OldMD && OldMD->isConst()) { 6770 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>(); 6771 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 6772 EPI.TypeQuals |= Qualifiers::Const; 6773 FT = Context.getFunctionType(FPT->getReturnType(), 6774 FPT->getParamTypes(), EPI); 6775 } 6776 } 6777 6778 // C++ [temp.expl.spec]p11: 6779 // A trailing template-argument can be left unspecified in the 6780 // template-id naming an explicit function template specialization 6781 // provided it can be deduced from the function argument type. 6782 // Perform template argument deduction to determine whether we may be 6783 // specializing this template. 6784 // FIXME: It is somewhat wasteful to build 6785 TemplateDeductionInfo Info(FailedCandidates.getLocation()); 6786 FunctionDecl *Specialization = nullptr; 6787 if (TemplateDeductionResult TDK = DeduceTemplateArguments( 6788 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()), 6789 ExplicitTemplateArgs, FT, Specialization, Info)) { 6790 // Template argument deduction failed; record why it failed, so 6791 // that we can provide nifty diagnostics. 6792 FailedCandidates.addCandidate() 6793 .set(FunTmpl->getTemplatedDecl(), 6794 MakeDeductionFailureInfo(Context, TDK, Info)); 6795 (void)TDK; 6796 continue; 6797 } 6798 6799 // Record this candidate. 6800 Candidates.addDecl(Specialization, I.getAccess()); 6801 } 6802 } 6803 6804 // Find the most specialized function template. 6805 UnresolvedSetIterator Result = getMostSpecialized( 6806 Candidates.begin(), Candidates.end(), FailedCandidates, 6807 FD->getLocation(), 6808 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(), 6809 PDiag(diag::err_function_template_spec_ambiguous) 6810 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr), 6811 PDiag(diag::note_function_template_spec_matched)); 6812 6813 if (Result == Candidates.end()) 6814 return true; 6815 6816 // Ignore access information; it doesn't figure into redeclaration checking. 6817 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 6818 6819 FunctionTemplateSpecializationInfo *SpecInfo 6820 = Specialization->getTemplateSpecializationInfo(); 6821 assert(SpecInfo && "Function template specialization info missing?"); 6822 6823 // Note: do not overwrite location info if previous template 6824 // specialization kind was explicit. 6825 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind(); 6826 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) { 6827 Specialization->setLocation(FD->getLocation()); 6828 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr 6829 // function can differ from the template declaration with respect to 6830 // the constexpr specifier. 6831 Specialization->setConstexpr(FD->isConstexpr()); 6832 } 6833 6834 // FIXME: Check if the prior specialization has a point of instantiation. 6835 // If so, we have run afoul of . 6836 6837 // If this is a friend declaration, then we're not really declaring 6838 // an explicit specialization. 6839 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None); 6840 6841 // Check the scope of this explicit specialization. 6842 if (!isFriend && 6843 CheckTemplateSpecializationScope(*this, 6844 Specialization->getPrimaryTemplate(), 6845 Specialization, FD->getLocation(), 6846 false)) 6847 return true; 6848 6849 // C++ [temp.expl.spec]p6: 6850 // If a template, a member template or the member of a class template is 6851 // explicitly specialized then that specialization shall be declared 6852 // before the first use of that specialization that would cause an implicit 6853 // instantiation to take place, in every translation unit in which such a 6854 // use occurs; no diagnostic is required. 6855 bool HasNoEffect = false; 6856 if (!isFriend && 6857 CheckSpecializationInstantiationRedecl(FD->getLocation(), 6858 TSK_ExplicitSpecialization, 6859 Specialization, 6860 SpecInfo->getTemplateSpecializationKind(), 6861 SpecInfo->getPointOfInstantiation(), 6862 HasNoEffect)) 6863 return true; 6864 6865 // Mark the prior declaration as an explicit specialization, so that later 6866 // clients know that this is an explicit specialization. 6867 if (!isFriend) { 6868 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization); 6869 MarkUnusedFileScopedDecl(Specialization); 6870 } 6871 6872 // Turn the given function declaration into a function template 6873 // specialization, with the template arguments from the previous 6874 // specialization. 6875 // Take copies of (semantic and syntactic) template argument lists. 6876 const TemplateArgumentList* TemplArgs = new (Context) 6877 TemplateArgumentList(Specialization->getTemplateSpecializationArgs()); 6878 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(), 6879 TemplArgs, /*InsertPos=*/nullptr, 6880 SpecInfo->getTemplateSpecializationKind(), 6881 ExplicitTemplateArgs); 6882 6883 // The "previous declaration" for this function template specialization is 6884 // the prior function template specialization. 6885 Previous.clear(); 6886 Previous.addDecl(Specialization); 6887 return false; 6888 } 6889 6890 /// \brief Perform semantic analysis for the given non-template member 6891 /// specialization. 6892 /// 6893 /// This routine performs all of the semantic analysis required for an 6894 /// explicit member function specialization. On successful completion, 6895 /// the function declaration \p FD will become a member function 6896 /// specialization. 6897 /// 6898 /// \param Member the member declaration, which will be updated to become a 6899 /// specialization. 6900 /// 6901 /// \param Previous the set of declarations, one of which may be specialized 6902 /// by this function specialization; the set will be modified to contain the 6903 /// redeclared member. 6904 bool 6905 Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) { 6906 assert(!isa<TemplateDecl>(Member) && "Only for non-template members"); 6907 6908 // Try to find the member we are instantiating. 6909 NamedDecl *Instantiation = nullptr; 6910 NamedDecl *InstantiatedFrom = nullptr; 6911 MemberSpecializationInfo *MSInfo = nullptr; 6912 6913 if (Previous.empty()) { 6914 // Nowhere to look anyway. 6915 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) { 6916 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 6917 I != E; ++I) { 6918 NamedDecl *D = (*I)->getUnderlyingDecl(); 6919 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 6920 QualType Adjusted = Function->getType(); 6921 if (!hasExplicitCallingConv(Adjusted)) 6922 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType()); 6923 if (Context.hasSameType(Adjusted, Method->getType())) { 6924 Instantiation = Method; 6925 InstantiatedFrom = Method->getInstantiatedFromMemberFunction(); 6926 MSInfo = Method->getMemberSpecializationInfo(); 6927 break; 6928 } 6929 } 6930 } 6931 } else if (isa<VarDecl>(Member)) { 6932 VarDecl *PrevVar; 6933 if (Previous.isSingleResult() && 6934 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl()))) 6935 if (PrevVar->isStaticDataMember()) { 6936 Instantiation = PrevVar; 6937 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember(); 6938 MSInfo = PrevVar->getMemberSpecializationInfo(); 6939 } 6940 } else if (isa<RecordDecl>(Member)) { 6941 CXXRecordDecl *PrevRecord; 6942 if (Previous.isSingleResult() && 6943 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) { 6944 Instantiation = PrevRecord; 6945 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass(); 6946 MSInfo = PrevRecord->getMemberSpecializationInfo(); 6947 } 6948 } else if (isa<EnumDecl>(Member)) { 6949 EnumDecl *PrevEnum; 6950 if (Previous.isSingleResult() && 6951 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) { 6952 Instantiation = PrevEnum; 6953 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum(); 6954 MSInfo = PrevEnum->getMemberSpecializationInfo(); 6955 } 6956 } 6957 6958 if (!Instantiation) { 6959 // There is no previous declaration that matches. Since member 6960 // specializations are always out-of-line, the caller will complain about 6961 // this mismatch later. 6962 return false; 6963 } 6964 6965 // If this is a friend, just bail out here before we start turning 6966 // things into explicit specializations. 6967 if (Member->getFriendObjectKind() != Decl::FOK_None) { 6968 // Preserve instantiation information. 6969 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) { 6970 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction( 6971 cast<CXXMethodDecl>(InstantiatedFrom), 6972 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind()); 6973 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) { 6974 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 6975 cast<CXXRecordDecl>(InstantiatedFrom), 6976 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind()); 6977 } 6978 6979 Previous.clear(); 6980 Previous.addDecl(Instantiation); 6981 return false; 6982 } 6983 6984 // Make sure that this is a specialization of a member. 6985 if (!InstantiatedFrom) { 6986 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated) 6987 << Member; 6988 Diag(Instantiation->getLocation(), diag::note_specialized_decl); 6989 return true; 6990 } 6991 6992 // C++ [temp.expl.spec]p6: 6993 // If a template, a member template or the member of a class template is 6994 // explicitly specialized then that specialization shall be declared 6995 // before the first use of that specialization that would cause an implicit 6996 // instantiation to take place, in every translation unit in which such a 6997 // use occurs; no diagnostic is required. 6998 assert(MSInfo && "Member specialization info missing?"); 6999 7000 bool HasNoEffect = false; 7001 if (CheckSpecializationInstantiationRedecl(Member->getLocation(), 7002 TSK_ExplicitSpecialization, 7003 Instantiation, 7004 MSInfo->getTemplateSpecializationKind(), 7005 MSInfo->getPointOfInstantiation(), 7006 HasNoEffect)) 7007 return true; 7008 7009 // Check the scope of this explicit specialization. 7010 if (CheckTemplateSpecializationScope(*this, 7011 InstantiatedFrom, 7012 Instantiation, Member->getLocation(), 7013 false)) 7014 return true; 7015 7016 // Note that this is an explicit instantiation of a member. 7017 // the original declaration to note that it is an explicit specialization 7018 // (if it was previously an implicit instantiation). This latter step 7019 // makes bookkeeping easier. 7020 if (isa<FunctionDecl>(Member)) { 7021 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation); 7022 if (InstantiationFunction->getTemplateSpecializationKind() == 7023 TSK_ImplicitInstantiation) { 7024 InstantiationFunction->setTemplateSpecializationKind( 7025 TSK_ExplicitSpecialization); 7026 InstantiationFunction->setLocation(Member->getLocation()); 7027 } 7028 7029 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction( 7030 cast<CXXMethodDecl>(InstantiatedFrom), 7031 TSK_ExplicitSpecialization); 7032 MarkUnusedFileScopedDecl(InstantiationFunction); 7033 } else if (isa<VarDecl>(Member)) { 7034 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation); 7035 if (InstantiationVar->getTemplateSpecializationKind() == 7036 TSK_ImplicitInstantiation) { 7037 InstantiationVar->setTemplateSpecializationKind( 7038 TSK_ExplicitSpecialization); 7039 InstantiationVar->setLocation(Member->getLocation()); 7040 } 7041 7042 cast<VarDecl>(Member)->setInstantiationOfStaticDataMember( 7043 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization); 7044 MarkUnusedFileScopedDecl(InstantiationVar); 7045 } else if (isa<CXXRecordDecl>(Member)) { 7046 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation); 7047 if (InstantiationClass->getTemplateSpecializationKind() == 7048 TSK_ImplicitInstantiation) { 7049 InstantiationClass->setTemplateSpecializationKind( 7050 TSK_ExplicitSpecialization); 7051 InstantiationClass->setLocation(Member->getLocation()); 7052 } 7053 7054 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 7055 cast<CXXRecordDecl>(InstantiatedFrom), 7056 TSK_ExplicitSpecialization); 7057 } else { 7058 assert(isa<EnumDecl>(Member) && "Only member enums remain"); 7059 EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation); 7060 if (InstantiationEnum->getTemplateSpecializationKind() == 7061 TSK_ImplicitInstantiation) { 7062 InstantiationEnum->setTemplateSpecializationKind( 7063 TSK_ExplicitSpecialization); 7064 InstantiationEnum->setLocation(Member->getLocation()); 7065 } 7066 7067 cast<EnumDecl>(Member)->setInstantiationOfMemberEnum( 7068 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization); 7069 } 7070 7071 // Save the caller the trouble of having to figure out which declaration 7072 // this specialization matches. 7073 Previous.clear(); 7074 Previous.addDecl(Instantiation); 7075 return false; 7076 } 7077 7078 /// \brief Check the scope of an explicit instantiation. 7079 /// 7080 /// \returns true if a serious error occurs, false otherwise. 7081 static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D, 7082 SourceLocation InstLoc, 7083 bool WasQualifiedName) { 7084 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext(); 7085 DeclContext *CurContext = S.CurContext->getRedeclContext(); 7086 7087 if (CurContext->isRecord()) { 7088 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class) 7089 << D; 7090 return true; 7091 } 7092 7093 // C++11 [temp.explicit]p3: 7094 // An explicit instantiation shall appear in an enclosing namespace of its 7095 // template. If the name declared in the explicit instantiation is an 7096 // unqualified name, the explicit instantiation shall appear in the 7097 // namespace where its template is declared or, if that namespace is inline 7098 // (7.3.1), any namespace from its enclosing namespace set. 7099 // 7100 // This is DR275, which we do not retroactively apply to C++98/03. 7101 if (WasQualifiedName) { 7102 if (CurContext->Encloses(OrigContext)) 7103 return false; 7104 } else { 7105 if (CurContext->InEnclosingNamespaceSetOf(OrigContext)) 7106 return false; 7107 } 7108 7109 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) { 7110 if (WasQualifiedName) 7111 S.Diag(InstLoc, 7112 S.getLangOpts().CPlusPlus11? 7113 diag::err_explicit_instantiation_out_of_scope : 7114 diag::warn_explicit_instantiation_out_of_scope_0x) 7115 << D << NS; 7116 else 7117 S.Diag(InstLoc, 7118 S.getLangOpts().CPlusPlus11? 7119 diag::err_explicit_instantiation_unqualified_wrong_namespace : 7120 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x) 7121 << D << NS; 7122 } else 7123 S.Diag(InstLoc, 7124 S.getLangOpts().CPlusPlus11? 7125 diag::err_explicit_instantiation_must_be_global : 7126 diag::warn_explicit_instantiation_must_be_global_0x) 7127 << D; 7128 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 7129 return false; 7130 } 7131 7132 /// \brief Determine whether the given scope specifier has a template-id in it. 7133 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) { 7134 if (!SS.isSet()) 7135 return false; 7136 7137 // C++11 [temp.explicit]p3: 7138 // If the explicit instantiation is for a member function, a member class 7139 // or a static data member of a class template specialization, the name of 7140 // the class template specialization in the qualified-id for the member 7141 // name shall be a simple-template-id. 7142 // 7143 // C++98 has the same restriction, just worded differently. 7144 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS; 7145 NNS = NNS->getPrefix()) 7146 if (const Type *T = NNS->getAsType()) 7147 if (isa<TemplateSpecializationType>(T)) 7148 return true; 7149 7150 return false; 7151 } 7152 7153 // Explicit instantiation of a class template specialization 7154 DeclResult 7155 Sema::ActOnExplicitInstantiation(Scope *S, 7156 SourceLocation ExternLoc, 7157 SourceLocation TemplateLoc, 7158 unsigned TagSpec, 7159 SourceLocation KWLoc, 7160 const CXXScopeSpec &SS, 7161 TemplateTy TemplateD, 7162 SourceLocation TemplateNameLoc, 7163 SourceLocation LAngleLoc, 7164 ASTTemplateArgsPtr TemplateArgsIn, 7165 SourceLocation RAngleLoc, 7166 AttributeList *Attr) { 7167 // Find the class template we're specializing 7168 TemplateName Name = TemplateD.get(); 7169 TemplateDecl *TD = Name.getAsTemplateDecl(); 7170 // Check that the specialization uses the same tag kind as the 7171 // original template. 7172 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 7173 assert(Kind != TTK_Enum && 7174 "Invalid enum tag in class template explicit instantiation!"); 7175 7176 if (isa<TypeAliasTemplateDecl>(TD)) { 7177 Diag(KWLoc, diag::err_tag_reference_non_tag) << Kind; 7178 Diag(TD->getTemplatedDecl()->getLocation(), 7179 diag::note_previous_use); 7180 return true; 7181 } 7182 7183 ClassTemplateDecl *ClassTemplate = cast<ClassTemplateDecl>(TD); 7184 7185 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 7186 Kind, /*isDefinition*/false, KWLoc, 7187 *ClassTemplate->getIdentifier())) { 7188 Diag(KWLoc, diag::err_use_with_wrong_tag) 7189 << ClassTemplate 7190 << FixItHint::CreateReplacement(KWLoc, 7191 ClassTemplate->getTemplatedDecl()->getKindName()); 7192 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 7193 diag::note_previous_use); 7194 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 7195 } 7196 7197 // C++0x [temp.explicit]p2: 7198 // There are two forms of explicit instantiation: an explicit instantiation 7199 // definition and an explicit instantiation declaration. An explicit 7200 // instantiation declaration begins with the extern keyword. [...] 7201 TemplateSpecializationKind TSK = ExternLoc.isInvalid() 7202 ? TSK_ExplicitInstantiationDefinition 7203 : TSK_ExplicitInstantiationDeclaration; 7204 7205 if (TSK == TSK_ExplicitInstantiationDeclaration) { 7206 // Check for dllexport class template instantiation declarations. 7207 for (AttributeList *A = Attr; A; A = A->getNext()) { 7208 if (A->getKind() == AttributeList::AT_DLLExport) { 7209 Diag(ExternLoc, 7210 diag::warn_attribute_dllexport_explicit_instantiation_decl); 7211 Diag(A->getLoc(), diag::note_attribute); 7212 break; 7213 } 7214 } 7215 7216 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) { 7217 Diag(ExternLoc, 7218 diag::warn_attribute_dllexport_explicit_instantiation_decl); 7219 Diag(A->getLocation(), diag::note_attribute); 7220 } 7221 } 7222 7223 // Translate the parser's template argument list in our AST format. 7224 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 7225 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 7226 7227 // Check that the template argument list is well-formed for this 7228 // template. 7229 SmallVector<TemplateArgument, 4> Converted; 7230 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 7231 TemplateArgs, false, Converted)) 7232 return true; 7233 7234 // Find the class template specialization declaration that 7235 // corresponds to these arguments. 7236 void *InsertPos = nullptr; 7237 ClassTemplateSpecializationDecl *PrevDecl 7238 = ClassTemplate->findSpecialization(Converted, InsertPos); 7239 7240 TemplateSpecializationKind PrevDecl_TSK 7241 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared; 7242 7243 // C++0x [temp.explicit]p2: 7244 // [...] An explicit instantiation shall appear in an enclosing 7245 // namespace of its template. [...] 7246 // 7247 // This is C++ DR 275. 7248 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc, 7249 SS.isSet())) 7250 return true; 7251 7252 ClassTemplateSpecializationDecl *Specialization = nullptr; 7253 7254 bool HasNoEffect = false; 7255 if (PrevDecl) { 7256 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK, 7257 PrevDecl, PrevDecl_TSK, 7258 PrevDecl->getPointOfInstantiation(), 7259 HasNoEffect)) 7260 return PrevDecl; 7261 7262 // Even though HasNoEffect == true means that this explicit instantiation 7263 // has no effect on semantics, we go on to put its syntax in the AST. 7264 7265 if (PrevDecl_TSK == TSK_ImplicitInstantiation || 7266 PrevDecl_TSK == TSK_Undeclared) { 7267 // Since the only prior class template specialization with these 7268 // arguments was referenced but not declared, reuse that 7269 // declaration node as our own, updating the source location 7270 // for the template name to reflect our new declaration. 7271 // (Other source locations will be updated later.) 7272 Specialization = PrevDecl; 7273 Specialization->setLocation(TemplateNameLoc); 7274 PrevDecl = nullptr; 7275 } 7276 } 7277 7278 if (!Specialization) { 7279 // Create a new class template specialization declaration node for 7280 // this explicit specialization. 7281 Specialization 7282 = ClassTemplateSpecializationDecl::Create(Context, Kind, 7283 ClassTemplate->getDeclContext(), 7284 KWLoc, TemplateNameLoc, 7285 ClassTemplate, 7286 Converted.data(), 7287 Converted.size(), 7288 PrevDecl); 7289 SetNestedNameSpecifier(Specialization, SS); 7290 7291 if (!HasNoEffect && !PrevDecl) { 7292 // Insert the new specialization. 7293 ClassTemplate->AddSpecialization(Specialization, InsertPos); 7294 } 7295 } 7296 7297 // Build the fully-sugared type for this explicit instantiation as 7298 // the user wrote in the explicit instantiation itself. This means 7299 // that we'll pretty-print the type retrieved from the 7300 // specialization's declaration the way that the user actually wrote 7301 // the explicit instantiation, rather than formatting the name based 7302 // on the "canonical" representation used to store the template 7303 // arguments in the specialization. 7304 TypeSourceInfo *WrittenTy 7305 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 7306 TemplateArgs, 7307 Context.getTypeDeclType(Specialization)); 7308 Specialization->setTypeAsWritten(WrittenTy); 7309 7310 // Set source locations for keywords. 7311 Specialization->setExternLoc(ExternLoc); 7312 Specialization->setTemplateKeywordLoc(TemplateLoc); 7313 Specialization->setRBraceLoc(SourceLocation()); 7314 7315 if (Attr) 7316 ProcessDeclAttributeList(S, Specialization, Attr); 7317 7318 // Add the explicit instantiation into its lexical context. However, 7319 // since explicit instantiations are never found by name lookup, we 7320 // just put it into the declaration context directly. 7321 Specialization->setLexicalDeclContext(CurContext); 7322 CurContext->addDecl(Specialization); 7323 7324 // Syntax is now OK, so return if it has no other effect on semantics. 7325 if (HasNoEffect) { 7326 // Set the template specialization kind. 7327 Specialization->setTemplateSpecializationKind(TSK); 7328 return Specialization; 7329 } 7330 7331 // C++ [temp.explicit]p3: 7332 // A definition of a class template or class member template 7333 // shall be in scope at the point of the explicit instantiation of 7334 // the class template or class member template. 7335 // 7336 // This check comes when we actually try to perform the 7337 // instantiation. 7338 ClassTemplateSpecializationDecl *Def 7339 = cast_or_null<ClassTemplateSpecializationDecl>( 7340 Specialization->getDefinition()); 7341 if (!Def) 7342 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK); 7343 else if (TSK == TSK_ExplicitInstantiationDefinition) { 7344 MarkVTableUsed(TemplateNameLoc, Specialization, true); 7345 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation()); 7346 } 7347 7348 // Instantiate the members of this class template specialization. 7349 Def = cast_or_null<ClassTemplateSpecializationDecl>( 7350 Specialization->getDefinition()); 7351 if (Def) { 7352 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind(); 7353 7354 // Fix a TSK_ExplicitInstantiationDeclaration followed by a 7355 // TSK_ExplicitInstantiationDefinition 7356 if (Old_TSK == TSK_ExplicitInstantiationDeclaration && 7357 TSK == TSK_ExplicitInstantiationDefinition) 7358 // FIXME: Need to notify the ASTMutationListener that we did this. 7359 Def->setTemplateSpecializationKind(TSK); 7360 7361 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK); 7362 } 7363 7364 // Set the template specialization kind. 7365 Specialization->setTemplateSpecializationKind(TSK); 7366 return Specialization; 7367 } 7368 7369 // Explicit instantiation of a member class of a class template. 7370 DeclResult 7371 Sema::ActOnExplicitInstantiation(Scope *S, 7372 SourceLocation ExternLoc, 7373 SourceLocation TemplateLoc, 7374 unsigned TagSpec, 7375 SourceLocation KWLoc, 7376 CXXScopeSpec &SS, 7377 IdentifierInfo *Name, 7378 SourceLocation NameLoc, 7379 AttributeList *Attr) { 7380 7381 bool Owned = false; 7382 bool IsDependent = false; 7383 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference, 7384 KWLoc, SS, Name, NameLoc, Attr, AS_none, 7385 /*ModulePrivateLoc=*/SourceLocation(), 7386 MultiTemplateParamsArg(), Owned, IsDependent, 7387 SourceLocation(), false, TypeResult(), 7388 /*IsTypeSpecifier*/false); 7389 assert(!IsDependent && "explicit instantiation of dependent name not yet handled"); 7390 7391 if (!TagD) 7392 return true; 7393 7394 TagDecl *Tag = cast<TagDecl>(TagD); 7395 assert(!Tag->isEnum() && "shouldn't see enumerations here"); 7396 7397 if (Tag->isInvalidDecl()) 7398 return true; 7399 7400 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag); 7401 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass(); 7402 if (!Pattern) { 7403 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type) 7404 << Context.getTypeDeclType(Record); 7405 Diag(Record->getLocation(), diag::note_nontemplate_decl_here); 7406 return true; 7407 } 7408 7409 // C++0x [temp.explicit]p2: 7410 // If the explicit instantiation is for a class or member class, the 7411 // elaborated-type-specifier in the declaration shall include a 7412 // simple-template-id. 7413 // 7414 // C++98 has the same restriction, just worded differently. 7415 if (!ScopeSpecifierHasTemplateId(SS)) 7416 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id) 7417 << Record << SS.getRange(); 7418 7419 // C++0x [temp.explicit]p2: 7420 // There are two forms of explicit instantiation: an explicit instantiation 7421 // definition and an explicit instantiation declaration. An explicit 7422 // instantiation declaration begins with the extern keyword. [...] 7423 TemplateSpecializationKind TSK 7424 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 7425 : TSK_ExplicitInstantiationDeclaration; 7426 7427 // C++0x [temp.explicit]p2: 7428 // [...] An explicit instantiation shall appear in an enclosing 7429 // namespace of its template. [...] 7430 // 7431 // This is C++ DR 275. 7432 CheckExplicitInstantiationScope(*this, Record, NameLoc, true); 7433 7434 // Verify that it is okay to explicitly instantiate here. 7435 CXXRecordDecl *PrevDecl 7436 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl()); 7437 if (!PrevDecl && Record->getDefinition()) 7438 PrevDecl = Record; 7439 if (PrevDecl) { 7440 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo(); 7441 bool HasNoEffect = false; 7442 assert(MSInfo && "No member specialization information?"); 7443 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK, 7444 PrevDecl, 7445 MSInfo->getTemplateSpecializationKind(), 7446 MSInfo->getPointOfInstantiation(), 7447 HasNoEffect)) 7448 return true; 7449 if (HasNoEffect) 7450 return TagD; 7451 } 7452 7453 CXXRecordDecl *RecordDef 7454 = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 7455 if (!RecordDef) { 7456 // C++ [temp.explicit]p3: 7457 // A definition of a member class of a class template shall be in scope 7458 // at the point of an explicit instantiation of the member class. 7459 CXXRecordDecl *Def 7460 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition()); 7461 if (!Def) { 7462 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member) 7463 << 0 << Record->getDeclName() << Record->getDeclContext(); 7464 Diag(Pattern->getLocation(), diag::note_forward_declaration) 7465 << Pattern; 7466 return true; 7467 } else { 7468 if (InstantiateClass(NameLoc, Record, Def, 7469 getTemplateInstantiationArgs(Record), 7470 TSK)) 7471 return true; 7472 7473 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 7474 if (!RecordDef) 7475 return true; 7476 } 7477 } 7478 7479 // Instantiate all of the members of the class. 7480 InstantiateClassMembers(NameLoc, RecordDef, 7481 getTemplateInstantiationArgs(Record), TSK); 7482 7483 if (TSK == TSK_ExplicitInstantiationDefinition) 7484 MarkVTableUsed(NameLoc, RecordDef, true); 7485 7486 // FIXME: We don't have any representation for explicit instantiations of 7487 // member classes. Such a representation is not needed for compilation, but it 7488 // should be available for clients that want to see all of the declarations in 7489 // the source code. 7490 return TagD; 7491 } 7492 7493 DeclResult Sema::ActOnExplicitInstantiation(Scope *S, 7494 SourceLocation ExternLoc, 7495 SourceLocation TemplateLoc, 7496 Declarator &D) { 7497 // Explicit instantiations always require a name. 7498 // TODO: check if/when DNInfo should replace Name. 7499 DeclarationNameInfo NameInfo = GetNameForDeclarator(D); 7500 DeclarationName Name = NameInfo.getName(); 7501 if (!Name) { 7502 if (!D.isInvalidType()) 7503 Diag(D.getDeclSpec().getLocStart(), 7504 diag::err_explicit_instantiation_requires_name) 7505 << D.getDeclSpec().getSourceRange() 7506 << D.getSourceRange(); 7507 7508 return true; 7509 } 7510 7511 // The scope passed in may not be a decl scope. Zip up the scope tree until 7512 // we find one that is. 7513 while ((S->getFlags() & Scope::DeclScope) == 0 || 7514 (S->getFlags() & Scope::TemplateParamScope) != 0) 7515 S = S->getParent(); 7516 7517 // Determine the type of the declaration. 7518 TypeSourceInfo *T = GetTypeForDeclarator(D, S); 7519 QualType R = T->getType(); 7520 if (R.isNull()) 7521 return true; 7522 7523 // C++ [dcl.stc]p1: 7524 // A storage-class-specifier shall not be specified in [...] an explicit 7525 // instantiation (14.7.2) directive. 7526 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 7527 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef) 7528 << Name; 7529 return true; 7530 } else if (D.getDeclSpec().getStorageClassSpec() 7531 != DeclSpec::SCS_unspecified) { 7532 // Complain about then remove the storage class specifier. 7533 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class) 7534 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); 7535 7536 D.getMutableDeclSpec().ClearStorageClassSpecs(); 7537 } 7538 7539 // C++0x [temp.explicit]p1: 7540 // [...] An explicit instantiation of a function template shall not use the 7541 // inline or constexpr specifiers. 7542 // Presumably, this also applies to member functions of class templates as 7543 // well. 7544 if (D.getDeclSpec().isInlineSpecified()) 7545 Diag(D.getDeclSpec().getInlineSpecLoc(), 7546 getLangOpts().CPlusPlus11 ? 7547 diag::err_explicit_instantiation_inline : 7548 diag::warn_explicit_instantiation_inline_0x) 7549 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); 7550 if (D.getDeclSpec().isConstexprSpecified() && R->isFunctionType()) 7551 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is 7552 // not already specified. 7553 Diag(D.getDeclSpec().getConstexprSpecLoc(), 7554 diag::err_explicit_instantiation_constexpr); 7555 7556 // C++0x [temp.explicit]p2: 7557 // There are two forms of explicit instantiation: an explicit instantiation 7558 // definition and an explicit instantiation declaration. An explicit 7559 // instantiation declaration begins with the extern keyword. [...] 7560 TemplateSpecializationKind TSK 7561 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 7562 : TSK_ExplicitInstantiationDeclaration; 7563 7564 LookupResult Previous(*this, NameInfo, LookupOrdinaryName); 7565 LookupParsedName(Previous, S, &D.getCXXScopeSpec()); 7566 7567 if (!R->isFunctionType()) { 7568 // C++ [temp.explicit]p1: 7569 // A [...] static data member of a class template can be explicitly 7570 // instantiated from the member definition associated with its class 7571 // template. 7572 // C++1y [temp.explicit]p1: 7573 // A [...] variable [...] template specialization can be explicitly 7574 // instantiated from its template. 7575 if (Previous.isAmbiguous()) 7576 return true; 7577 7578 VarDecl *Prev = Previous.getAsSingle<VarDecl>(); 7579 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>(); 7580 7581 if (!PrevTemplate) { 7582 if (!Prev || !Prev->isStaticDataMember()) { 7583 // We expect to see a data data member here. 7584 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known) 7585 << Name; 7586 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 7587 P != PEnd; ++P) 7588 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here); 7589 return true; 7590 } 7591 7592 if (!Prev->getInstantiatedFromStaticDataMember()) { 7593 // FIXME: Check for explicit specialization? 7594 Diag(D.getIdentifierLoc(), 7595 diag::err_explicit_instantiation_data_member_not_instantiated) 7596 << Prev; 7597 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here); 7598 // FIXME: Can we provide a note showing where this was declared? 7599 return true; 7600 } 7601 } else { 7602 // Explicitly instantiate a variable template. 7603 7604 // C++1y [dcl.spec.auto]p6: 7605 // ... A program that uses auto or decltype(auto) in a context not 7606 // explicitly allowed in this section is ill-formed. 7607 // 7608 // This includes auto-typed variable template instantiations. 7609 if (R->isUndeducedType()) { 7610 Diag(T->getTypeLoc().getLocStart(), 7611 diag::err_auto_not_allowed_var_inst); 7612 return true; 7613 } 7614 7615 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId) { 7616 // C++1y [temp.explicit]p3: 7617 // If the explicit instantiation is for a variable, the unqualified-id 7618 // in the declaration shall be a template-id. 7619 Diag(D.getIdentifierLoc(), 7620 diag::err_explicit_instantiation_without_template_id) 7621 << PrevTemplate; 7622 Diag(PrevTemplate->getLocation(), 7623 diag::note_explicit_instantiation_here); 7624 return true; 7625 } 7626 7627 // Translate the parser's template argument list into our AST format. 7628 TemplateArgumentListInfo TemplateArgs = 7629 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId); 7630 7631 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc, 7632 D.getIdentifierLoc(), TemplateArgs); 7633 if (Res.isInvalid()) 7634 return true; 7635 7636 // Ignore access control bits, we don't need them for redeclaration 7637 // checking. 7638 Prev = cast<VarDecl>(Res.get()); 7639 } 7640 7641 // C++0x [temp.explicit]p2: 7642 // If the explicit instantiation is for a member function, a member class 7643 // or a static data member of a class template specialization, the name of 7644 // the class template specialization in the qualified-id for the member 7645 // name shall be a simple-template-id. 7646 // 7647 // C++98 has the same restriction, just worded differently. 7648 // 7649 // This does not apply to variable template specializations, where the 7650 // template-id is in the unqualified-id instead. 7651 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate) 7652 Diag(D.getIdentifierLoc(), 7653 diag::ext_explicit_instantiation_without_qualified_id) 7654 << Prev << D.getCXXScopeSpec().getRange(); 7655 7656 // Check the scope of this explicit instantiation. 7657 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true); 7658 7659 // Verify that it is okay to explicitly instantiate here. 7660 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind(); 7661 SourceLocation POI = Prev->getPointOfInstantiation(); 7662 bool HasNoEffect = false; 7663 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev, 7664 PrevTSK, POI, HasNoEffect)) 7665 return true; 7666 7667 if (!HasNoEffect) { 7668 // Instantiate static data member or variable template. 7669 7670 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 7671 if (PrevTemplate) { 7672 // Merge attributes. 7673 if (AttributeList *Attr = D.getDeclSpec().getAttributes().getList()) 7674 ProcessDeclAttributeList(S, Prev, Attr); 7675 } 7676 if (TSK == TSK_ExplicitInstantiationDefinition) 7677 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev); 7678 } 7679 7680 // Check the new variable specialization against the parsed input. 7681 if (PrevTemplate && Prev && !Context.hasSameType(Prev->getType(), R)) { 7682 Diag(T->getTypeLoc().getLocStart(), 7683 diag::err_invalid_var_template_spec_type) 7684 << 0 << PrevTemplate << R << Prev->getType(); 7685 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here) 7686 << 2 << PrevTemplate->getDeclName(); 7687 return true; 7688 } 7689 7690 // FIXME: Create an ExplicitInstantiation node? 7691 return (Decl*) nullptr; 7692 } 7693 7694 // If the declarator is a template-id, translate the parser's template 7695 // argument list into our AST format. 7696 bool HasExplicitTemplateArgs = false; 7697 TemplateArgumentListInfo TemplateArgs; 7698 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 7699 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId); 7700 HasExplicitTemplateArgs = true; 7701 } 7702 7703 // C++ [temp.explicit]p1: 7704 // A [...] function [...] can be explicitly instantiated from its template. 7705 // A member function [...] of a class template can be explicitly 7706 // instantiated from the member definition associated with its class 7707 // template. 7708 UnresolvedSet<8> Matches; 7709 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc()); 7710 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 7711 P != PEnd; ++P) { 7712 NamedDecl *Prev = *P; 7713 if (!HasExplicitTemplateArgs) { 7714 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) { 7715 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType()); 7716 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) { 7717 Matches.clear(); 7718 7719 Matches.addDecl(Method, P.getAccess()); 7720 if (Method->getTemplateSpecializationKind() == TSK_Undeclared) 7721 break; 7722 } 7723 } 7724 } 7725 7726 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev); 7727 if (!FunTmpl) 7728 continue; 7729 7730 TemplateDeductionInfo Info(FailedCandidates.getLocation()); 7731 FunctionDecl *Specialization = nullptr; 7732 if (TemplateDeductionResult TDK 7733 = DeduceTemplateArguments(FunTmpl, 7734 (HasExplicitTemplateArgs ? &TemplateArgs 7735 : nullptr), 7736 R, Specialization, Info)) { 7737 // Keep track of almost-matches. 7738 FailedCandidates.addCandidate() 7739 .set(FunTmpl->getTemplatedDecl(), 7740 MakeDeductionFailureInfo(Context, TDK, Info)); 7741 (void)TDK; 7742 continue; 7743 } 7744 7745 Matches.addDecl(Specialization, P.getAccess()); 7746 } 7747 7748 // Find the most specialized function template specialization. 7749 UnresolvedSetIterator Result = getMostSpecialized( 7750 Matches.begin(), Matches.end(), FailedCandidates, 7751 D.getIdentifierLoc(), 7752 PDiag(diag::err_explicit_instantiation_not_known) << Name, 7753 PDiag(diag::err_explicit_instantiation_ambiguous) << Name, 7754 PDiag(diag::note_explicit_instantiation_candidate)); 7755 7756 if (Result == Matches.end()) 7757 return true; 7758 7759 // Ignore access control bits, we don't need them for redeclaration checking. 7760 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 7761 7762 // C++11 [except.spec]p4 7763 // In an explicit instantiation an exception-specification may be specified, 7764 // but is not required. 7765 // If an exception-specification is specified in an explicit instantiation 7766 // directive, it shall be compatible with the exception-specifications of 7767 // other declarations of that function. 7768 if (auto *FPT = R->getAs<FunctionProtoType>()) 7769 if (FPT->hasExceptionSpec()) { 7770 unsigned DiagID = 7771 diag::err_mismatched_exception_spec_explicit_instantiation; 7772 if (getLangOpts().MicrosoftExt) 7773 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation; 7774 bool Result = CheckEquivalentExceptionSpec( 7775 PDiag(DiagID) << Specialization->getType(), 7776 PDiag(diag::note_explicit_instantiation_here), 7777 Specialization->getType()->getAs<FunctionProtoType>(), 7778 Specialization->getLocation(), FPT, D.getLocStart()); 7779 // In Microsoft mode, mismatching exception specifications just cause a 7780 // warning. 7781 if (!getLangOpts().MicrosoftExt && Result) 7782 return true; 7783 } 7784 7785 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) { 7786 Diag(D.getIdentifierLoc(), 7787 diag::err_explicit_instantiation_member_function_not_instantiated) 7788 << Specialization 7789 << (Specialization->getTemplateSpecializationKind() == 7790 TSK_ExplicitSpecialization); 7791 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here); 7792 return true; 7793 } 7794 7795 FunctionDecl *PrevDecl = Specialization->getPreviousDecl(); 7796 if (!PrevDecl && Specialization->isThisDeclarationADefinition()) 7797 PrevDecl = Specialization; 7798 7799 if (PrevDecl) { 7800 bool HasNoEffect = false; 7801 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, 7802 PrevDecl, 7803 PrevDecl->getTemplateSpecializationKind(), 7804 PrevDecl->getPointOfInstantiation(), 7805 HasNoEffect)) 7806 return true; 7807 7808 // FIXME: We may still want to build some representation of this 7809 // explicit specialization. 7810 if (HasNoEffect) 7811 return (Decl*) nullptr; 7812 } 7813 7814 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 7815 AttributeList *Attr = D.getDeclSpec().getAttributes().getList(); 7816 if (Attr) 7817 ProcessDeclAttributeList(S, Specialization, Attr); 7818 7819 if (Specialization->isDefined()) { 7820 // Let the ASTConsumer know that this function has been explicitly 7821 // instantiated now, and its linkage might have changed. 7822 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization)); 7823 } else if (TSK == TSK_ExplicitInstantiationDefinition) 7824 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization); 7825 7826 // C++0x [temp.explicit]p2: 7827 // If the explicit instantiation is for a member function, a member class 7828 // or a static data member of a class template specialization, the name of 7829 // the class template specialization in the qualified-id for the member 7830 // name shall be a simple-template-id. 7831 // 7832 // C++98 has the same restriction, just worded differently. 7833 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate(); 7834 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl && 7835 D.getCXXScopeSpec().isSet() && 7836 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 7837 Diag(D.getIdentifierLoc(), 7838 diag::ext_explicit_instantiation_without_qualified_id) 7839 << Specialization << D.getCXXScopeSpec().getRange(); 7840 7841 CheckExplicitInstantiationScope(*this, 7842 FunTmpl? (NamedDecl *)FunTmpl 7843 : Specialization->getInstantiatedFromMemberFunction(), 7844 D.getIdentifierLoc(), 7845 D.getCXXScopeSpec().isSet()); 7846 7847 // FIXME: Create some kind of ExplicitInstantiationDecl here. 7848 return (Decl*) nullptr; 7849 } 7850 7851 TypeResult 7852 Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 7853 const CXXScopeSpec &SS, IdentifierInfo *Name, 7854 SourceLocation TagLoc, SourceLocation NameLoc) { 7855 // This has to hold, because SS is expected to be defined. 7856 assert(Name && "Expected a name in a dependent tag"); 7857 7858 NestedNameSpecifier *NNS = SS.getScopeRep(); 7859 if (!NNS) 7860 return true; 7861 7862 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 7863 7864 if (TUK == TUK_Declaration || TUK == TUK_Definition) { 7865 Diag(NameLoc, diag::err_dependent_tag_decl) 7866 << (TUK == TUK_Definition) << Kind << SS.getRange(); 7867 return true; 7868 } 7869 7870 // Create the resulting type. 7871 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 7872 QualType Result = Context.getDependentNameType(Kwd, NNS, Name); 7873 7874 // Create type-source location information for this type. 7875 TypeLocBuilder TLB; 7876 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result); 7877 TL.setElaboratedKeywordLoc(TagLoc); 7878 TL.setQualifierLoc(SS.getWithLocInContext(Context)); 7879 TL.setNameLoc(NameLoc); 7880 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result)); 7881 } 7882 7883 TypeResult 7884 Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 7885 const CXXScopeSpec &SS, const IdentifierInfo &II, 7886 SourceLocation IdLoc) { 7887 if (SS.isInvalid()) 7888 return true; 7889 7890 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent()) 7891 Diag(TypenameLoc, 7892 getLangOpts().CPlusPlus11 ? 7893 diag::warn_cxx98_compat_typename_outside_of_template : 7894 diag::ext_typename_outside_of_template) 7895 << FixItHint::CreateRemoval(TypenameLoc); 7896 7897 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); 7898 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None, 7899 TypenameLoc, QualifierLoc, II, IdLoc); 7900 if (T.isNull()) 7901 return true; 7902 7903 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 7904 if (isa<DependentNameType>(T)) { 7905 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>(); 7906 TL.setElaboratedKeywordLoc(TypenameLoc); 7907 TL.setQualifierLoc(QualifierLoc); 7908 TL.setNameLoc(IdLoc); 7909 } else { 7910 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>(); 7911 TL.setElaboratedKeywordLoc(TypenameLoc); 7912 TL.setQualifierLoc(QualifierLoc); 7913 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc); 7914 } 7915 7916 return CreateParsedType(T, TSI); 7917 } 7918 7919 TypeResult 7920 Sema::ActOnTypenameType(Scope *S, 7921 SourceLocation TypenameLoc, 7922 const CXXScopeSpec &SS, 7923 SourceLocation TemplateKWLoc, 7924 TemplateTy TemplateIn, 7925 SourceLocation TemplateNameLoc, 7926 SourceLocation LAngleLoc, 7927 ASTTemplateArgsPtr TemplateArgsIn, 7928 SourceLocation RAngleLoc) { 7929 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent()) 7930 Diag(TypenameLoc, 7931 getLangOpts().CPlusPlus11 ? 7932 diag::warn_cxx98_compat_typename_outside_of_template : 7933 diag::ext_typename_outside_of_template) 7934 << FixItHint::CreateRemoval(TypenameLoc); 7935 7936 // Translate the parser's template argument list in our AST format. 7937 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 7938 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 7939 7940 TemplateName Template = TemplateIn.get(); 7941 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) { 7942 // Construct a dependent template specialization type. 7943 assert(DTN && "dependent template has non-dependent name?"); 7944 assert(DTN->getQualifier() == SS.getScopeRep()); 7945 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename, 7946 DTN->getQualifier(), 7947 DTN->getIdentifier(), 7948 TemplateArgs); 7949 7950 // Create source-location information for this type. 7951 TypeLocBuilder Builder; 7952 DependentTemplateSpecializationTypeLoc SpecTL 7953 = Builder.push<DependentTemplateSpecializationTypeLoc>(T); 7954 SpecTL.setElaboratedKeywordLoc(TypenameLoc); 7955 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 7956 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 7957 SpecTL.setTemplateNameLoc(TemplateNameLoc); 7958 SpecTL.setLAngleLoc(LAngleLoc); 7959 SpecTL.setRAngleLoc(RAngleLoc); 7960 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 7961 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 7962 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T)); 7963 } 7964 7965 QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs); 7966 if (T.isNull()) 7967 return true; 7968 7969 // Provide source-location information for the template specialization type. 7970 TypeLocBuilder Builder; 7971 TemplateSpecializationTypeLoc SpecTL 7972 = Builder.push<TemplateSpecializationTypeLoc>(T); 7973 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 7974 SpecTL.setTemplateNameLoc(TemplateNameLoc); 7975 SpecTL.setLAngleLoc(LAngleLoc); 7976 SpecTL.setRAngleLoc(RAngleLoc); 7977 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 7978 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 7979 7980 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T); 7981 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T); 7982 TL.setElaboratedKeywordLoc(TypenameLoc); 7983 TL.setQualifierLoc(SS.getWithLocInContext(Context)); 7984 7985 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T); 7986 return CreateParsedType(T, TSI); 7987 } 7988 7989 7990 /// Determine whether this failed name lookup should be treated as being 7991 /// disabled by a usage of std::enable_if. 7992 static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II, 7993 SourceRange &CondRange) { 7994 // We must be looking for a ::type... 7995 if (!II.isStr("type")) 7996 return false; 7997 7998 // ... within an explicitly-written template specialization... 7999 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType()) 8000 return false; 8001 TypeLoc EnableIfTy = NNS.getTypeLoc(); 8002 TemplateSpecializationTypeLoc EnableIfTSTLoc = 8003 EnableIfTy.getAs<TemplateSpecializationTypeLoc>(); 8004 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0) 8005 return false; 8006 const TemplateSpecializationType *EnableIfTST = 8007 cast<TemplateSpecializationType>(EnableIfTSTLoc.getTypePtr()); 8008 8009 // ... which names a complete class template declaration... 8010 const TemplateDecl *EnableIfDecl = 8011 EnableIfTST->getTemplateName().getAsTemplateDecl(); 8012 if (!EnableIfDecl || EnableIfTST->isIncompleteType()) 8013 return false; 8014 8015 // ... called "enable_if". 8016 const IdentifierInfo *EnableIfII = 8017 EnableIfDecl->getDeclName().getAsIdentifierInfo(); 8018 if (!EnableIfII || !EnableIfII->isStr("enable_if")) 8019 return false; 8020 8021 // Assume the first template argument is the condition. 8022 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange(); 8023 return true; 8024 } 8025 8026 /// \brief Build the type that describes a C++ typename specifier, 8027 /// e.g., "typename T::type". 8028 QualType 8029 Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword, 8030 SourceLocation KeywordLoc, 8031 NestedNameSpecifierLoc QualifierLoc, 8032 const IdentifierInfo &II, 8033 SourceLocation IILoc) { 8034 CXXScopeSpec SS; 8035 SS.Adopt(QualifierLoc); 8036 8037 DeclContext *Ctx = computeDeclContext(SS); 8038 if (!Ctx) { 8039 // If the nested-name-specifier is dependent and couldn't be 8040 // resolved to a type, build a typename type. 8041 assert(QualifierLoc.getNestedNameSpecifier()->isDependent()); 8042 return Context.getDependentNameType(Keyword, 8043 QualifierLoc.getNestedNameSpecifier(), 8044 &II); 8045 } 8046 8047 // If the nested-name-specifier refers to the current instantiation, 8048 // the "typename" keyword itself is superfluous. In C++03, the 8049 // program is actually ill-formed. However, DR 382 (in C++0x CD1) 8050 // allows such extraneous "typename" keywords, and we retroactively 8051 // apply this DR to C++03 code with only a warning. In any case we continue. 8052 8053 if (RequireCompleteDeclContext(SS, Ctx)) 8054 return QualType(); 8055 8056 DeclarationName Name(&II); 8057 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName); 8058 LookupQualifiedName(Result, Ctx, SS); 8059 unsigned DiagID = 0; 8060 Decl *Referenced = nullptr; 8061 switch (Result.getResultKind()) { 8062 case LookupResult::NotFound: { 8063 // If we're looking up 'type' within a template named 'enable_if', produce 8064 // a more specific diagnostic. 8065 SourceRange CondRange; 8066 if (isEnableIf(QualifierLoc, II, CondRange)) { 8067 Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if) 8068 << Ctx << CondRange; 8069 return QualType(); 8070 } 8071 8072 DiagID = diag::err_typename_nested_not_found; 8073 break; 8074 } 8075 8076 case LookupResult::FoundUnresolvedValue: { 8077 // We found a using declaration that is a value. Most likely, the using 8078 // declaration itself is meant to have the 'typename' keyword. 8079 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(), 8080 IILoc); 8081 Diag(IILoc, diag::err_typename_refers_to_using_value_decl) 8082 << Name << Ctx << FullRange; 8083 if (UnresolvedUsingValueDecl *Using 8084 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){ 8085 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc(); 8086 Diag(Loc, diag::note_using_value_decl_missing_typename) 8087 << FixItHint::CreateInsertion(Loc, "typename "); 8088 } 8089 } 8090 // Fall through to create a dependent typename type, from which we can recover 8091 // better. 8092 8093 case LookupResult::NotFoundInCurrentInstantiation: 8094 // Okay, it's a member of an unknown instantiation. 8095 return Context.getDependentNameType(Keyword, 8096 QualifierLoc.getNestedNameSpecifier(), 8097 &II); 8098 8099 case LookupResult::Found: 8100 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) { 8101 // We found a type. Build an ElaboratedType, since the 8102 // typename-specifier was just sugar. 8103 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); 8104 return Context.getElaboratedType(ETK_Typename, 8105 QualifierLoc.getNestedNameSpecifier(), 8106 Context.getTypeDeclType(Type)); 8107 } 8108 8109 DiagID = diag::err_typename_nested_not_type; 8110 Referenced = Result.getFoundDecl(); 8111 break; 8112 8113 case LookupResult::FoundOverloaded: 8114 DiagID = diag::err_typename_nested_not_type; 8115 Referenced = *Result.begin(); 8116 break; 8117 8118 case LookupResult::Ambiguous: 8119 return QualType(); 8120 } 8121 8122 // If we get here, it's because name lookup did not find a 8123 // type. Emit an appropriate diagnostic and return an error. 8124 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(), 8125 IILoc); 8126 Diag(IILoc, DiagID) << FullRange << Name << Ctx; 8127 if (Referenced) 8128 Diag(Referenced->getLocation(), diag::note_typename_refers_here) 8129 << Name; 8130 return QualType(); 8131 } 8132 8133 namespace { 8134 // See Sema::RebuildTypeInCurrentInstantiation 8135 class CurrentInstantiationRebuilder 8136 : public TreeTransform<CurrentInstantiationRebuilder> { 8137 SourceLocation Loc; 8138 DeclarationName Entity; 8139 8140 public: 8141 typedef TreeTransform<CurrentInstantiationRebuilder> inherited; 8142 8143 CurrentInstantiationRebuilder(Sema &SemaRef, 8144 SourceLocation Loc, 8145 DeclarationName Entity) 8146 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef), 8147 Loc(Loc), Entity(Entity) { } 8148 8149 /// \brief Determine whether the given type \p T has already been 8150 /// transformed. 8151 /// 8152 /// For the purposes of type reconstruction, a type has already been 8153 /// transformed if it is NULL or if it is not dependent. 8154 bool AlreadyTransformed(QualType T) { 8155 return T.isNull() || !T->isDependentType(); 8156 } 8157 8158 /// \brief Returns the location of the entity whose type is being 8159 /// rebuilt. 8160 SourceLocation getBaseLocation() { return Loc; } 8161 8162 /// \brief Returns the name of the entity whose type is being rebuilt. 8163 DeclarationName getBaseEntity() { return Entity; } 8164 8165 /// \brief Sets the "base" location and entity when that 8166 /// information is known based on another transformation. 8167 void setBase(SourceLocation Loc, DeclarationName Entity) { 8168 this->Loc = Loc; 8169 this->Entity = Entity; 8170 } 8171 8172 ExprResult TransformLambdaExpr(LambdaExpr *E) { 8173 // Lambdas never need to be transformed. 8174 return E; 8175 } 8176 }; 8177 } 8178 8179 /// \brief Rebuilds a type within the context of the current instantiation. 8180 /// 8181 /// The type \p T is part of the type of an out-of-line member definition of 8182 /// a class template (or class template partial specialization) that was parsed 8183 /// and constructed before we entered the scope of the class template (or 8184 /// partial specialization thereof). This routine will rebuild that type now 8185 /// that we have entered the declarator's scope, which may produce different 8186 /// canonical types, e.g., 8187 /// 8188 /// \code 8189 /// template<typename T> 8190 /// struct X { 8191 /// typedef T* pointer; 8192 /// pointer data(); 8193 /// }; 8194 /// 8195 /// template<typename T> 8196 /// typename X<T>::pointer X<T>::data() { ... } 8197 /// \endcode 8198 /// 8199 /// Here, the type "typename X<T>::pointer" will be created as a DependentNameType, 8200 /// since we do not know that we can look into X<T> when we parsed the type. 8201 /// This function will rebuild the type, performing the lookup of "pointer" 8202 /// in X<T> and returning an ElaboratedType whose canonical type is the same 8203 /// as the canonical type of T*, allowing the return types of the out-of-line 8204 /// definition and the declaration to match. 8205 TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T, 8206 SourceLocation Loc, 8207 DeclarationName Name) { 8208 if (!T || !T->getType()->isDependentType()) 8209 return T; 8210 8211 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name); 8212 return Rebuilder.TransformType(T); 8213 } 8214 8215 ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) { 8216 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(), 8217 DeclarationName()); 8218 return Rebuilder.TransformExpr(E); 8219 } 8220 8221 bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) { 8222 if (SS.isInvalid()) 8223 return true; 8224 8225 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); 8226 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(), 8227 DeclarationName()); 8228 NestedNameSpecifierLoc Rebuilt 8229 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc); 8230 if (!Rebuilt) 8231 return true; 8232 8233 SS.Adopt(Rebuilt); 8234 return false; 8235 } 8236 8237 /// \brief Rebuild the template parameters now that we know we're in a current 8238 /// instantiation. 8239 bool Sema::RebuildTemplateParamsInCurrentInstantiation( 8240 TemplateParameterList *Params) { 8241 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 8242 Decl *Param = Params->getParam(I); 8243 8244 // There is nothing to rebuild in a type parameter. 8245 if (isa<TemplateTypeParmDecl>(Param)) 8246 continue; 8247 8248 // Rebuild the template parameter list of a template template parameter. 8249 if (TemplateTemplateParmDecl *TTP 8250 = dyn_cast<TemplateTemplateParmDecl>(Param)) { 8251 if (RebuildTemplateParamsInCurrentInstantiation( 8252 TTP->getTemplateParameters())) 8253 return true; 8254 8255 continue; 8256 } 8257 8258 // Rebuild the type of a non-type template parameter. 8259 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param); 8260 TypeSourceInfo *NewTSI 8261 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(), 8262 NTTP->getLocation(), 8263 NTTP->getDeclName()); 8264 if (!NewTSI) 8265 return true; 8266 8267 if (NewTSI != NTTP->getTypeSourceInfo()) { 8268 NTTP->setTypeSourceInfo(NewTSI); 8269 NTTP->setType(NewTSI->getType()); 8270 } 8271 } 8272 8273 return false; 8274 } 8275 8276 /// \brief Produces a formatted string that describes the binding of 8277 /// template parameters to template arguments. 8278 std::string 8279 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 8280 const TemplateArgumentList &Args) { 8281 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size()); 8282 } 8283 8284 std::string 8285 Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 8286 const TemplateArgument *Args, 8287 unsigned NumArgs) { 8288 SmallString<128> Str; 8289 llvm::raw_svector_ostream Out(Str); 8290 8291 if (!Params || Params->size() == 0 || NumArgs == 0) 8292 return std::string(); 8293 8294 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 8295 if (I >= NumArgs) 8296 break; 8297 8298 if (I == 0) 8299 Out << "[with "; 8300 else 8301 Out << ", "; 8302 8303 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) { 8304 Out << Id->getName(); 8305 } else { 8306 Out << '$' << I; 8307 } 8308 8309 Out << " = "; 8310 Args[I].print(getPrintingPolicy(), Out); 8311 } 8312 8313 Out << ']'; 8314 return Out.str(); 8315 } 8316 8317 void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD, 8318 CachedTokens &Toks) { 8319 if (!FD) 8320 return; 8321 8322 LateParsedTemplate *LPT = new LateParsedTemplate; 8323 8324 // Take tokens to avoid allocations 8325 LPT->Toks.swap(Toks); 8326 LPT->D = FnD; 8327 LateParsedTemplateMap.insert(std::make_pair(FD, LPT)); 8328 8329 FD->setLateTemplateParsed(true); 8330 } 8331 8332 void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) { 8333 if (!FD) 8334 return; 8335 FD->setLateTemplateParsed(false); 8336 } 8337 8338 bool Sema::IsInsideALocalClassWithinATemplateFunction() { 8339 DeclContext *DC = CurContext; 8340 8341 while (DC) { 8342 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) { 8343 const FunctionDecl *FD = RD->isLocalClass(); 8344 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate); 8345 } else if (DC->isTranslationUnit() || DC->isNamespace()) 8346 return false; 8347 8348 DC = DC->getParent(); 8349 } 8350 return false; 8351 } 8352