SemaTemplate.cpp revision 219077
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 "clang/Sema/SemaInternal.h" 13#include "clang/Sema/Lookup.h" 14#include "clang/Sema/Scope.h" 15#include "clang/Sema/Template.h" 16#include "clang/Sema/TemplateDeduction.h" 17#include "TreeTransform.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/DeclFriend.h" 22#include "clang/AST/DeclTemplate.h" 23#include "clang/AST/RecursiveASTVisitor.h" 24#include "clang/AST/TypeVisitor.h" 25#include "clang/Sema/DeclSpec.h" 26#include "clang/Sema/ParsedTemplate.h" 27#include "clang/Basic/LangOptions.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "llvm/ADT/StringExtras.h" 30using namespace clang; 31using namespace sema; 32 33// Exported for use by Parser. 34SourceRange 35clang::getTemplateParamsRange(TemplateParameterList const * const *Ps, 36 unsigned N) { 37 if (!N) return SourceRange(); 38 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc()); 39} 40 41/// \brief Determine whether the declaration found is acceptable as the name 42/// of a template and, if so, return that template declaration. Otherwise, 43/// returns NULL. 44static NamedDecl *isAcceptableTemplateName(ASTContext &Context, 45 NamedDecl *Orig) { 46 NamedDecl *D = Orig->getUnderlyingDecl(); 47 48 if (isa<TemplateDecl>(D)) 49 return Orig; 50 51 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) { 52 // C++ [temp.local]p1: 53 // Like normal (non-template) classes, class templates have an 54 // injected-class-name (Clause 9). The injected-class-name 55 // can be used with or without a template-argument-list. When 56 // it is used without a template-argument-list, it is 57 // equivalent to the injected-class-name followed by the 58 // template-parameters of the class template enclosed in 59 // <>. When it is used with a template-argument-list, it 60 // refers to the specified class template specialization, 61 // which could be the current specialization or another 62 // specialization. 63 if (Record->isInjectedClassName()) { 64 Record = cast<CXXRecordDecl>(Record->getDeclContext()); 65 if (Record->getDescribedClassTemplate()) 66 return Record->getDescribedClassTemplate(); 67 68 if (ClassTemplateSpecializationDecl *Spec 69 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) 70 return Spec->getSpecializedTemplate(); 71 } 72 73 return 0; 74 } 75 76 return 0; 77} 78 79static void FilterAcceptableTemplateNames(ASTContext &C, LookupResult &R) { 80 // The set of class templates we've already seen. 81 llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates; 82 LookupResult::Filter filter = R.makeFilter(); 83 while (filter.hasNext()) { 84 NamedDecl *Orig = filter.next(); 85 NamedDecl *Repl = isAcceptableTemplateName(C, Orig); 86 if (!Repl) 87 filter.erase(); 88 else if (Repl != Orig) { 89 90 // C++ [temp.local]p3: 91 // A lookup that finds an injected-class-name (10.2) can result in an 92 // ambiguity in certain cases (for example, if it is found in more than 93 // one base class). If all of the injected-class-names that are found 94 // refer to specializations of the same class template, and if the name 95 // is followed by a template-argument-list, the reference refers to the 96 // class template itself and not a specialization thereof, and is not 97 // ambiguous. 98 // 99 // FIXME: Will we eventually have to do the same for alias templates? 100 if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl)) 101 if (!ClassTemplates.insert(ClassTmpl)) { 102 filter.erase(); 103 continue; 104 } 105 106 // FIXME: we promote access to public here as a workaround to 107 // the fact that LookupResult doesn't let us remember that we 108 // found this template through a particular injected class name, 109 // which means we end up doing nasty things to the invariants. 110 // Pretending that access is public is *much* safer. 111 filter.replace(Repl, AS_public); 112 } 113 } 114 filter.done(); 115} 116 117TemplateNameKind Sema::isTemplateName(Scope *S, 118 CXXScopeSpec &SS, 119 bool hasTemplateKeyword, 120 UnqualifiedId &Name, 121 ParsedType ObjectTypePtr, 122 bool EnteringContext, 123 TemplateTy &TemplateResult, 124 bool &MemberOfUnknownSpecialization) { 125 assert(getLangOptions().CPlusPlus && "No template names in C!"); 126 127 DeclarationName TName; 128 MemberOfUnknownSpecialization = false; 129 130 switch (Name.getKind()) { 131 case UnqualifiedId::IK_Identifier: 132 TName = DeclarationName(Name.Identifier); 133 break; 134 135 case UnqualifiedId::IK_OperatorFunctionId: 136 TName = Context.DeclarationNames.getCXXOperatorName( 137 Name.OperatorFunctionId.Operator); 138 break; 139 140 case UnqualifiedId::IK_LiteralOperatorId: 141 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier); 142 break; 143 144 default: 145 return TNK_Non_template; 146 } 147 148 QualType ObjectType = ObjectTypePtr.get(); 149 150 LookupResult R(*this, TName, Name.getSourceRange().getBegin(), 151 LookupOrdinaryName); 152 LookupTemplateName(R, S, SS, ObjectType, EnteringContext, 153 MemberOfUnknownSpecialization); 154 if (R.empty()) return TNK_Non_template; 155 if (R.isAmbiguous()) { 156 // Suppress diagnostics; we'll redo this lookup later. 157 R.suppressDiagnostics(); 158 159 // FIXME: we might have ambiguous templates, in which case we 160 // should at least parse them properly! 161 return TNK_Non_template; 162 } 163 164 TemplateName Template; 165 TemplateNameKind TemplateKind; 166 167 unsigned ResultCount = R.end() - R.begin(); 168 if (ResultCount > 1) { 169 // We assume that we'll preserve the qualifier from a function 170 // template name in other ways. 171 Template = Context.getOverloadedTemplateName(R.begin(), R.end()); 172 TemplateKind = TNK_Function_template; 173 174 // We'll do this lookup again later. 175 R.suppressDiagnostics(); 176 } else { 177 TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl()); 178 179 if (SS.isSet() && !SS.isInvalid()) { 180 NestedNameSpecifier *Qualifier 181 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 182 Template = Context.getQualifiedTemplateName(Qualifier, 183 hasTemplateKeyword, TD); 184 } else { 185 Template = TemplateName(TD); 186 } 187 188 if (isa<FunctionTemplateDecl>(TD)) { 189 TemplateKind = TNK_Function_template; 190 191 // We'll do this lookup again later. 192 R.suppressDiagnostics(); 193 } else { 194 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD)); 195 TemplateKind = TNK_Type_template; 196 } 197 } 198 199 TemplateResult = TemplateTy::make(Template); 200 return TemplateKind; 201} 202 203bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II, 204 SourceLocation IILoc, 205 Scope *S, 206 const CXXScopeSpec *SS, 207 TemplateTy &SuggestedTemplate, 208 TemplateNameKind &SuggestedKind) { 209 // We can't recover unless there's a dependent scope specifier preceding the 210 // template name. 211 // FIXME: Typo correction? 212 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) || 213 computeDeclContext(*SS)) 214 return false; 215 216 // The code is missing a 'template' keyword prior to the dependent template 217 // name. 218 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep(); 219 Diag(IILoc, diag::err_template_kw_missing) 220 << Qualifier << II.getName() 221 << FixItHint::CreateInsertion(IILoc, "template "); 222 SuggestedTemplate 223 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II)); 224 SuggestedKind = TNK_Dependent_template_name; 225 return true; 226} 227 228void Sema::LookupTemplateName(LookupResult &Found, 229 Scope *S, CXXScopeSpec &SS, 230 QualType ObjectType, 231 bool EnteringContext, 232 bool &MemberOfUnknownSpecialization) { 233 // Determine where to perform name lookup 234 MemberOfUnknownSpecialization = false; 235 DeclContext *LookupCtx = 0; 236 bool isDependent = false; 237 if (!ObjectType.isNull()) { 238 // This nested-name-specifier occurs in a member access expression, e.g., 239 // x->B::f, and we are looking into the type of the object. 240 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 241 LookupCtx = computeDeclContext(ObjectType); 242 isDependent = ObjectType->isDependentType(); 243 assert((isDependent || !ObjectType->isIncompleteType()) && 244 "Caller should have completed object type"); 245 } else if (SS.isSet()) { 246 // This nested-name-specifier occurs after another nested-name-specifier, 247 // so long into the context associated with the prior nested-name-specifier. 248 LookupCtx = computeDeclContext(SS, EnteringContext); 249 isDependent = isDependentScopeSpecifier(SS); 250 251 // The declaration context must be complete. 252 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx)) 253 return; 254 } 255 256 bool ObjectTypeSearchedInScope = false; 257 if (LookupCtx) { 258 // Perform "qualified" name lookup into the declaration context we 259 // computed, which is either the type of the base of a member access 260 // expression or the declaration context associated with a prior 261 // nested-name-specifier. 262 LookupQualifiedName(Found, LookupCtx); 263 264 if (!ObjectType.isNull() && Found.empty()) { 265 // C++ [basic.lookup.classref]p1: 266 // In a class member access expression (5.2.5), if the . or -> token is 267 // immediately followed by an identifier followed by a <, the 268 // identifier must be looked up to determine whether the < is the 269 // beginning of a template argument list (14.2) or a less-than operator. 270 // The identifier is first looked up in the class of the object 271 // expression. If the identifier is not found, it is then looked up in 272 // the context of the entire postfix-expression and shall name a class 273 // or function template. 274 if (S) LookupName(Found, S); 275 ObjectTypeSearchedInScope = true; 276 } 277 } else if (isDependent && (!S || ObjectType.isNull())) { 278 // We cannot look into a dependent object type or nested nme 279 // specifier. 280 MemberOfUnknownSpecialization = true; 281 return; 282 } else { 283 // Perform unqualified name lookup in the current scope. 284 LookupName(Found, S); 285 } 286 287 if (Found.empty() && !isDependent) { 288 // If we did not find any names, attempt to correct any typos. 289 DeclarationName Name = Found.getLookupName(); 290 if (DeclarationName Corrected = CorrectTypo(Found, S, &SS, LookupCtx, 291 false, CTC_CXXCasts)) { 292 FilterAcceptableTemplateNames(Context, Found); 293 if (!Found.empty()) { 294 if (LookupCtx) 295 Diag(Found.getNameLoc(), diag::err_no_member_template_suggest) 296 << Name << LookupCtx << Found.getLookupName() << SS.getRange() 297 << FixItHint::CreateReplacement(Found.getNameLoc(), 298 Found.getLookupName().getAsString()); 299 else 300 Diag(Found.getNameLoc(), diag::err_no_template_suggest) 301 << Name << Found.getLookupName() 302 << FixItHint::CreateReplacement(Found.getNameLoc(), 303 Found.getLookupName().getAsString()); 304 if (TemplateDecl *Template = Found.getAsSingle<TemplateDecl>()) 305 Diag(Template->getLocation(), diag::note_previous_decl) 306 << Template->getDeclName(); 307 } 308 } else { 309 Found.clear(); 310 Found.setLookupName(Name); 311 } 312 } 313 314 FilterAcceptableTemplateNames(Context, Found); 315 if (Found.empty()) { 316 if (isDependent) 317 MemberOfUnknownSpecialization = true; 318 return; 319 } 320 321 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope) { 322 // C++ [basic.lookup.classref]p1: 323 // [...] If the lookup in the class of the object expression finds a 324 // template, the name is also looked up in the context of the entire 325 // postfix-expression and [...] 326 // 327 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(), 328 LookupOrdinaryName); 329 LookupName(FoundOuter, S); 330 FilterAcceptableTemplateNames(Context, FoundOuter); 331 332 if (FoundOuter.empty()) { 333 // - if the name is not found, the name found in the class of the 334 // object expression is used, otherwise 335 } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>()) { 336 // - if the name is found in the context of the entire 337 // postfix-expression and does not name a class template, the name 338 // found in the class of the object expression is used, otherwise 339 } else if (!Found.isSuppressingDiagnostics()) { 340 // - if the name found is a class template, it must refer to the same 341 // entity as the one found in the class of the object expression, 342 // otherwise the program is ill-formed. 343 if (!Found.isSingleResult() || 344 Found.getFoundDecl()->getCanonicalDecl() 345 != FoundOuter.getFoundDecl()->getCanonicalDecl()) { 346 Diag(Found.getNameLoc(), 347 diag::ext_nested_name_member_ref_lookup_ambiguous) 348 << Found.getLookupName() 349 << ObjectType; 350 Diag(Found.getRepresentativeDecl()->getLocation(), 351 diag::note_ambig_member_ref_object_type) 352 << ObjectType; 353 Diag(FoundOuter.getFoundDecl()->getLocation(), 354 diag::note_ambig_member_ref_scope); 355 356 // Recover by taking the template that we found in the object 357 // expression's type. 358 } 359 } 360 } 361} 362 363/// ActOnDependentIdExpression - Handle a dependent id-expression that 364/// was just parsed. This is only possible with an explicit scope 365/// specifier naming a dependent type. 366ExprResult 367Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS, 368 const DeclarationNameInfo &NameInfo, 369 bool isAddressOfOperand, 370 const TemplateArgumentListInfo *TemplateArgs) { 371 NestedNameSpecifier *Qualifier 372 = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 373 374 DeclContext *DC = getFunctionLevelDeclContext(); 375 376 if (!isAddressOfOperand && 377 isa<CXXMethodDecl>(DC) && 378 cast<CXXMethodDecl>(DC)->isInstance()) { 379 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 380 381 // Since the 'this' expression is synthesized, we don't need to 382 // perform the double-lookup check. 383 NamedDecl *FirstQualifierInScope = 0; 384 385 return Owned(CXXDependentScopeMemberExpr::Create(Context, 386 /*This*/ 0, ThisType, 387 /*IsArrow*/ true, 388 /*Op*/ SourceLocation(), 389 Qualifier, SS.getRange(), 390 FirstQualifierInScope, 391 NameInfo, 392 TemplateArgs)); 393 } 394 395 return BuildDependentDeclRefExpr(SS, NameInfo, TemplateArgs); 396} 397 398ExprResult 399Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS, 400 const DeclarationNameInfo &NameInfo, 401 const TemplateArgumentListInfo *TemplateArgs) { 402 return Owned(DependentScopeDeclRefExpr::Create(Context, 403 SS.getWithLocInContext(Context), 404 NameInfo, 405 TemplateArgs)); 406} 407 408/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining 409/// that the template parameter 'PrevDecl' is being shadowed by a new 410/// declaration at location Loc. Returns true to indicate that this is 411/// an error, and false otherwise. 412bool Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { 413 assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); 414 415 // Microsoft Visual C++ permits template parameters to be shadowed. 416 if (getLangOptions().Microsoft) 417 return false; 418 419 // C++ [temp.local]p4: 420 // A template-parameter shall not be redeclared within its 421 // scope (including nested scopes). 422 Diag(Loc, diag::err_template_param_shadow) 423 << cast<NamedDecl>(PrevDecl)->getDeclName(); 424 Diag(PrevDecl->getLocation(), diag::note_template_param_here); 425 return true; 426} 427 428/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset 429/// the parameter D to reference the templated declaration and return a pointer 430/// to the template declaration. Otherwise, do nothing to D and return null. 431TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) { 432 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) { 433 D = Temp->getTemplatedDecl(); 434 return Temp; 435 } 436 return 0; 437} 438 439ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion( 440 SourceLocation EllipsisLoc) const { 441 assert(Kind == Template && 442 "Only template template arguments can be pack expansions here"); 443 assert(getAsTemplate().get().containsUnexpandedParameterPack() && 444 "Template template argument pack expansion without packs"); 445 ParsedTemplateArgument Result(*this); 446 Result.EllipsisLoc = EllipsisLoc; 447 return Result; 448} 449 450static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef, 451 const ParsedTemplateArgument &Arg) { 452 453 switch (Arg.getKind()) { 454 case ParsedTemplateArgument::Type: { 455 TypeSourceInfo *DI; 456 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI); 457 if (!DI) 458 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation()); 459 return TemplateArgumentLoc(TemplateArgument(T), DI); 460 } 461 462 case ParsedTemplateArgument::NonType: { 463 Expr *E = static_cast<Expr *>(Arg.getAsExpr()); 464 return TemplateArgumentLoc(TemplateArgument(E), E); 465 } 466 467 case ParsedTemplateArgument::Template: { 468 TemplateName Template = Arg.getAsTemplate().get(); 469 TemplateArgument TArg; 470 if (Arg.getEllipsisLoc().isValid()) 471 TArg = TemplateArgument(Template, llvm::Optional<unsigned int>()); 472 else 473 TArg = Template; 474 return TemplateArgumentLoc(TArg, 475 Arg.getScopeSpec().getRange(), 476 Arg.getLocation(), 477 Arg.getEllipsisLoc()); 478 } 479 } 480 481 llvm_unreachable("Unhandled parsed template argument"); 482 return TemplateArgumentLoc(); 483} 484 485/// \brief Translates template arguments as provided by the parser 486/// into template arguments used by semantic analysis. 487void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn, 488 TemplateArgumentListInfo &TemplateArgs) { 489 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I) 490 TemplateArgs.addArgument(translateTemplateArgument(*this, 491 TemplateArgsIn[I])); 492} 493 494/// ActOnTypeParameter - Called when a C++ template type parameter 495/// (e.g., "typename T") has been parsed. Typename specifies whether 496/// the keyword "typename" was used to declare the type parameter 497/// (otherwise, "class" was used), and KeyLoc is the location of the 498/// "class" or "typename" keyword. ParamName is the name of the 499/// parameter (NULL indicates an unnamed template parameter) and 500/// ParamName is the location of the parameter name (if any). 501/// If the type parameter has a default argument, it will be added 502/// later via ActOnTypeParameterDefault. 503Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis, 504 SourceLocation EllipsisLoc, 505 SourceLocation KeyLoc, 506 IdentifierInfo *ParamName, 507 SourceLocation ParamNameLoc, 508 unsigned Depth, unsigned Position, 509 SourceLocation EqualLoc, 510 ParsedType DefaultArg) { 511 assert(S->isTemplateParamScope() && 512 "Template type parameter not in template parameter scope!"); 513 bool Invalid = false; 514 515 if (ParamName) { 516 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, ParamNameLoc, 517 LookupOrdinaryName, 518 ForRedeclaration); 519 if (PrevDecl && PrevDecl->isTemplateParameter()) 520 Invalid = Invalid || DiagnoseTemplateParameterShadow(ParamNameLoc, 521 PrevDecl); 522 } 523 524 SourceLocation Loc = ParamNameLoc; 525 if (!ParamName) 526 Loc = KeyLoc; 527 528 TemplateTypeParmDecl *Param 529 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(), 530 Loc, Depth, Position, ParamName, Typename, 531 Ellipsis); 532 if (Invalid) 533 Param->setInvalidDecl(); 534 535 if (ParamName) { 536 // Add the template parameter into the current scope. 537 S->AddDecl(Param); 538 IdResolver.AddDecl(Param); 539 } 540 541 // C++0x [temp.param]p9: 542 // A default template-argument may be specified for any kind of 543 // template-parameter that is not a template parameter pack. 544 if (DefaultArg && Ellipsis) { 545 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 546 DefaultArg = ParsedType(); 547 } 548 549 // Handle the default argument, if provided. 550 if (DefaultArg) { 551 TypeSourceInfo *DefaultTInfo; 552 GetTypeFromParser(DefaultArg, &DefaultTInfo); 553 554 assert(DefaultTInfo && "expected source information for type"); 555 556 // Check for unexpanded parameter packs. 557 if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo, 558 UPPC_DefaultArgument)) 559 return Param; 560 561 // Check the template argument itself. 562 if (CheckTemplateArgument(Param, DefaultTInfo)) { 563 Param->setInvalidDecl(); 564 return Param; 565 } 566 567 Param->setDefaultArgument(DefaultTInfo, false); 568 } 569 570 return Param; 571} 572 573/// \brief Check that the type of a non-type template parameter is 574/// well-formed. 575/// 576/// \returns the (possibly-promoted) parameter type if valid; 577/// otherwise, produces a diagnostic and returns a NULL type. 578QualType 579Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) { 580 // We don't allow variably-modified types as the type of non-type template 581 // parameters. 582 if (T->isVariablyModifiedType()) { 583 Diag(Loc, diag::err_variably_modified_nontype_template_param) 584 << T; 585 return QualType(); 586 } 587 588 // C++ [temp.param]p4: 589 // 590 // A non-type template-parameter shall have one of the following 591 // (optionally cv-qualified) types: 592 // 593 // -- integral or enumeration type, 594 if (T->isIntegralOrEnumerationType() || 595 // -- pointer to object or pointer to function, 596 T->isPointerType() || 597 // -- reference to object or reference to function, 598 T->isReferenceType() || 599 // -- pointer to member. 600 T->isMemberPointerType() || 601 // If T is a dependent type, we can't do the check now, so we 602 // assume that it is well-formed. 603 T->isDependentType()) 604 return T; 605 // C++ [temp.param]p8: 606 // 607 // A non-type template-parameter of type "array of T" or 608 // "function returning T" is adjusted to be of type "pointer to 609 // T" or "pointer to function returning T", respectively. 610 else if (T->isArrayType()) 611 // FIXME: Keep the type prior to promotion? 612 return Context.getArrayDecayedType(T); 613 else if (T->isFunctionType()) 614 // FIXME: Keep the type prior to promotion? 615 return Context.getPointerType(T); 616 617 Diag(Loc, diag::err_template_nontype_parm_bad_type) 618 << T; 619 620 return QualType(); 621} 622 623Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D, 624 unsigned Depth, 625 unsigned Position, 626 SourceLocation EqualLoc, 627 Expr *Default) { 628 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 629 QualType T = TInfo->getType(); 630 631 assert(S->isTemplateParamScope() && 632 "Non-type template parameter not in template parameter scope!"); 633 bool Invalid = false; 634 635 IdentifierInfo *ParamName = D.getIdentifier(); 636 if (ParamName) { 637 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, D.getIdentifierLoc(), 638 LookupOrdinaryName, 639 ForRedeclaration); 640 if (PrevDecl && PrevDecl->isTemplateParameter()) 641 Invalid = Invalid || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), 642 PrevDecl); 643 } 644 645 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc()); 646 if (T.isNull()) { 647 T = Context.IntTy; // Recover with an 'int' type. 648 Invalid = true; 649 } 650 651 bool IsParameterPack = D.hasEllipsis(); 652 NonTypeTemplateParmDecl *Param 653 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 654 D.getIdentifierLoc(), 655 Depth, Position, ParamName, T, 656 IsParameterPack, TInfo); 657 if (Invalid) 658 Param->setInvalidDecl(); 659 660 if (D.getIdentifier()) { 661 // Add the template parameter into the current scope. 662 S->AddDecl(Param); 663 IdResolver.AddDecl(Param); 664 } 665 666 // C++0x [temp.param]p9: 667 // A default template-argument may be specified for any kind of 668 // template-parameter that is not a template parameter pack. 669 if (Default && IsParameterPack) { 670 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 671 Default = 0; 672 } 673 674 // Check the well-formedness of the default template argument, if provided. 675 if (Default) { 676 // Check for unexpanded parameter packs. 677 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument)) 678 return Param; 679 680 TemplateArgument Converted; 681 if (CheckTemplateArgument(Param, Param->getType(), Default, Converted)) { 682 Param->setInvalidDecl(); 683 return Param; 684 } 685 686 Param->setDefaultArgument(Default, false); 687 } 688 689 return Param; 690} 691 692/// ActOnTemplateTemplateParameter - Called when a C++ template template 693/// parameter (e.g. T in template <template <typename> class T> class array) 694/// has been parsed. S is the current scope. 695Decl *Sema::ActOnTemplateTemplateParameter(Scope* S, 696 SourceLocation TmpLoc, 697 TemplateParamsTy *Params, 698 SourceLocation EllipsisLoc, 699 IdentifierInfo *Name, 700 SourceLocation NameLoc, 701 unsigned Depth, 702 unsigned Position, 703 SourceLocation EqualLoc, 704 ParsedTemplateArgument Default) { 705 assert(S->isTemplateParamScope() && 706 "Template template parameter not in template parameter scope!"); 707 708 // Construct the parameter object. 709 bool IsParameterPack = EllipsisLoc.isValid(); 710 // FIXME: Pack-ness is dropped 711 TemplateTemplateParmDecl *Param = 712 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 713 NameLoc.isInvalid()? TmpLoc : NameLoc, 714 Depth, Position, IsParameterPack, 715 Name, Params); 716 717 // If the template template parameter has a name, then link the identifier 718 // into the scope and lookup mechanisms. 719 if (Name) { 720 S->AddDecl(Param); 721 IdResolver.AddDecl(Param); 722 } 723 724 if (Params->size() == 0) { 725 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms) 726 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc()); 727 Param->setInvalidDecl(); 728 } 729 730 // C++0x [temp.param]p9: 731 // A default template-argument may be specified for any kind of 732 // template-parameter that is not a template parameter pack. 733 if (IsParameterPack && !Default.isInvalid()) { 734 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 735 Default = ParsedTemplateArgument(); 736 } 737 738 if (!Default.isInvalid()) { 739 // Check only that we have a template template argument. We don't want to 740 // try to check well-formedness now, because our template template parameter 741 // might have dependent types in its template parameters, which we wouldn't 742 // be able to match now. 743 // 744 // If none of the template template parameter's template arguments mention 745 // other template parameters, we could actually perform more checking here. 746 // However, it isn't worth doing. 747 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default); 748 if (DefaultArg.getArgument().getAsTemplate().isNull()) { 749 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template) 750 << DefaultArg.getSourceRange(); 751 return Param; 752 } 753 754 // Check for unexpanded parameter packs. 755 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(), 756 DefaultArg.getArgument().getAsTemplate(), 757 UPPC_DefaultArgument)) 758 return Param; 759 760 Param->setDefaultArgument(DefaultArg, false); 761 } 762 763 return Param; 764} 765 766/// ActOnTemplateParameterList - Builds a TemplateParameterList that 767/// contains the template parameters in Params/NumParams. 768Sema::TemplateParamsTy * 769Sema::ActOnTemplateParameterList(unsigned Depth, 770 SourceLocation ExportLoc, 771 SourceLocation TemplateLoc, 772 SourceLocation LAngleLoc, 773 Decl **Params, unsigned NumParams, 774 SourceLocation RAngleLoc) { 775 if (ExportLoc.isValid()) 776 Diag(ExportLoc, diag::warn_template_export_unsupported); 777 778 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc, 779 (NamedDecl**)Params, NumParams, 780 RAngleLoc); 781} 782 783static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) { 784 if (SS.isSet()) 785 T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext())); 786} 787 788DeclResult 789Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK, 790 SourceLocation KWLoc, CXXScopeSpec &SS, 791 IdentifierInfo *Name, SourceLocation NameLoc, 792 AttributeList *Attr, 793 TemplateParameterList *TemplateParams, 794 AccessSpecifier AS) { 795 assert(TemplateParams && TemplateParams->size() > 0 && 796 "No template parameters"); 797 assert(TUK != TUK_Reference && "Can only declare or define class templates"); 798 bool Invalid = false; 799 800 // Check that we can declare a template here. 801 if (CheckTemplateDeclScope(S, TemplateParams)) 802 return true; 803 804 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 805 assert(Kind != TTK_Enum && "can't build template of enumerated type"); 806 807 // There is no such thing as an unnamed class template. 808 if (!Name) { 809 Diag(KWLoc, diag::err_template_unnamed_class); 810 return true; 811 } 812 813 // Find any previous declaration with this name. 814 DeclContext *SemanticContext; 815 LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName, 816 ForRedeclaration); 817 if (SS.isNotEmpty() && !SS.isInvalid()) { 818 SemanticContext = computeDeclContext(SS, true); 819 if (!SemanticContext) { 820 // FIXME: Produce a reasonable diagnostic here 821 return true; 822 } 823 824 if (RequireCompleteDeclContext(SS, SemanticContext)) 825 return true; 826 827 LookupQualifiedName(Previous, SemanticContext); 828 } else { 829 SemanticContext = CurContext; 830 LookupName(Previous, S); 831 } 832 833 if (Previous.isAmbiguous()) 834 return true; 835 836 NamedDecl *PrevDecl = 0; 837 if (Previous.begin() != Previous.end()) 838 PrevDecl = (*Previous.begin())->getUnderlyingDecl(); 839 840 // If there is a previous declaration with the same name, check 841 // whether this is a valid redeclaration. 842 ClassTemplateDecl *PrevClassTemplate 843 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl); 844 845 // We may have found the injected-class-name of a class template, 846 // class template partial specialization, or class template specialization. 847 // In these cases, grab the template that is being defined or specialized. 848 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) && 849 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) { 850 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext()); 851 PrevClassTemplate 852 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate(); 853 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) { 854 PrevClassTemplate 855 = cast<ClassTemplateSpecializationDecl>(PrevDecl) 856 ->getSpecializedTemplate(); 857 } 858 } 859 860 if (TUK == TUK_Friend) { 861 // C++ [namespace.memdef]p3: 862 // [...] When looking for a prior declaration of a class or a function 863 // declared as a friend, and when the name of the friend class or 864 // function is neither a qualified name nor a template-id, scopes outside 865 // the innermost enclosing namespace scope are not considered. 866 if (!SS.isSet()) { 867 DeclContext *OutermostContext = CurContext; 868 while (!OutermostContext->isFileContext()) 869 OutermostContext = OutermostContext->getLookupParent(); 870 871 if (PrevDecl && 872 (OutermostContext->Equals(PrevDecl->getDeclContext()) || 873 OutermostContext->Encloses(PrevDecl->getDeclContext()))) { 874 SemanticContext = PrevDecl->getDeclContext(); 875 } else { 876 // Declarations in outer scopes don't matter. However, the outermost 877 // context we computed is the semantic context for our new 878 // declaration. 879 PrevDecl = PrevClassTemplate = 0; 880 SemanticContext = OutermostContext; 881 } 882 } 883 884 if (CurContext->isDependentContext()) { 885 // If this is a dependent context, we don't want to link the friend 886 // class template to the template in scope, because that would perform 887 // checking of the template parameter lists that can't be performed 888 // until the outer context is instantiated. 889 PrevDecl = PrevClassTemplate = 0; 890 } 891 } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S)) 892 PrevDecl = PrevClassTemplate = 0; 893 894 if (PrevClassTemplate) { 895 // Ensure that the template parameter lists are compatible. 896 if (!TemplateParameterListsAreEqual(TemplateParams, 897 PrevClassTemplate->getTemplateParameters(), 898 /*Complain=*/true, 899 TPL_TemplateMatch)) 900 return true; 901 902 // C++ [temp.class]p4: 903 // In a redeclaration, partial specialization, explicit 904 // specialization or explicit instantiation of a class template, 905 // the class-key shall agree in kind with the original class 906 // template declaration (7.1.5.3). 907 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl(); 908 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, KWLoc, *Name)) { 909 Diag(KWLoc, diag::err_use_with_wrong_tag) 910 << Name 911 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName()); 912 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use); 913 Kind = PrevRecordDecl->getTagKind(); 914 } 915 916 // Check for redefinition of this class template. 917 if (TUK == TUK_Definition) { 918 if (TagDecl *Def = PrevRecordDecl->getDefinition()) { 919 Diag(NameLoc, diag::err_redefinition) << Name; 920 Diag(Def->getLocation(), diag::note_previous_definition); 921 // FIXME: Would it make sense to try to "forget" the previous 922 // definition, as part of error recovery? 923 return true; 924 } 925 } 926 } else if (PrevDecl && PrevDecl->isTemplateParameter()) { 927 // Maybe we will complain about the shadowed template parameter. 928 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 929 // Just pretend that we didn't see the previous declaration. 930 PrevDecl = 0; 931 } else if (PrevDecl) { 932 // C++ [temp]p5: 933 // A class template shall not have the same name as any other 934 // template, class, function, object, enumeration, enumerator, 935 // namespace, or type in the same scope (3.3), except as specified 936 // in (14.5.4). 937 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 938 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 939 return true; 940 } 941 942 // Check the template parameter list of this declaration, possibly 943 // merging in the template parameter list from the previous class 944 // template declaration. 945 if (CheckTemplateParameterList(TemplateParams, 946 PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0, 947 (SS.isSet() && SemanticContext && 948 SemanticContext->isRecord() && 949 SemanticContext->isDependentContext()) 950 ? TPC_ClassTemplateMember 951 : TPC_ClassTemplate)) 952 Invalid = true; 953 954 if (SS.isSet()) { 955 // If the name of the template was qualified, we must be defining the 956 // template out-of-line. 957 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate && 958 !(TUK == TUK_Friend && CurContext->isDependentContext())) 959 Diag(NameLoc, diag::err_member_def_does_not_match) 960 << Name << SemanticContext << SS.getRange(); 961 } 962 963 CXXRecordDecl *NewClass = 964 CXXRecordDecl::Create(Context, Kind, SemanticContext, NameLoc, Name, KWLoc, 965 PrevClassTemplate? 966 PrevClassTemplate->getTemplatedDecl() : 0, 967 /*DelayTypeCreation=*/true); 968 SetNestedNameSpecifier(NewClass, SS); 969 970 ClassTemplateDecl *NewTemplate 971 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc, 972 DeclarationName(Name), TemplateParams, 973 NewClass, PrevClassTemplate); 974 NewClass->setDescribedClassTemplate(NewTemplate); 975 976 // Build the type for the class template declaration now. 977 QualType T = NewTemplate->getInjectedClassNameSpecialization(); 978 T = Context.getInjectedClassNameType(NewClass, T); 979 assert(T->isDependentType() && "Class template type is not dependent?"); 980 (void)T; 981 982 // If we are providing an explicit specialization of a member that is a 983 // class template, make a note of that. 984 if (PrevClassTemplate && 985 PrevClassTemplate->getInstantiatedFromMemberTemplate()) 986 PrevClassTemplate->setMemberSpecialization(); 987 988 // Set the access specifier. 989 if (!Invalid && TUK != TUK_Friend) 990 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS); 991 992 // Set the lexical context of these templates 993 NewClass->setLexicalDeclContext(CurContext); 994 NewTemplate->setLexicalDeclContext(CurContext); 995 996 if (TUK == TUK_Definition) 997 NewClass->startDefinition(); 998 999 if (Attr) 1000 ProcessDeclAttributeList(S, NewClass, Attr); 1001 1002 if (TUK != TUK_Friend) 1003 PushOnScopeChains(NewTemplate, S); 1004 else { 1005 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) { 1006 NewTemplate->setAccess(PrevClassTemplate->getAccess()); 1007 NewClass->setAccess(PrevClassTemplate->getAccess()); 1008 } 1009 1010 NewTemplate->setObjectOfFriendDecl(/* PreviouslyDeclared = */ 1011 PrevClassTemplate != NULL); 1012 1013 // Friend templates are visible in fairly strange ways. 1014 if (!CurContext->isDependentContext()) { 1015 DeclContext *DC = SemanticContext->getRedeclContext(); 1016 DC->makeDeclVisibleInContext(NewTemplate, /* Recoverable = */ false); 1017 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 1018 PushOnScopeChains(NewTemplate, EnclosingScope, 1019 /* AddToContext = */ false); 1020 } 1021 1022 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 1023 NewClass->getLocation(), 1024 NewTemplate, 1025 /*FIXME:*/NewClass->getLocation()); 1026 Friend->setAccess(AS_public); 1027 CurContext->addDecl(Friend); 1028 } 1029 1030 if (Invalid) { 1031 NewTemplate->setInvalidDecl(); 1032 NewClass->setInvalidDecl(); 1033 } 1034 return NewTemplate; 1035} 1036 1037/// \brief Diagnose the presence of a default template argument on a 1038/// template parameter, which is ill-formed in certain contexts. 1039/// 1040/// \returns true if the default template argument should be dropped. 1041static bool DiagnoseDefaultTemplateArgument(Sema &S, 1042 Sema::TemplateParamListContext TPC, 1043 SourceLocation ParamLoc, 1044 SourceRange DefArgRange) { 1045 switch (TPC) { 1046 case Sema::TPC_ClassTemplate: 1047 return false; 1048 1049 case Sema::TPC_FunctionTemplate: 1050 case Sema::TPC_FriendFunctionTemplateDefinition: 1051 // C++ [temp.param]p9: 1052 // A default template-argument shall not be specified in a 1053 // function template declaration or a function template 1054 // definition [...] 1055 // If a friend function template declaration specifies a default 1056 // template-argument, that declaration shall be a definition and shall be 1057 // the only declaration of the function template in the translation unit. 1058 // (C++98/03 doesn't have this wording; see DR226). 1059 if (!S.getLangOptions().CPlusPlus0x) 1060 S.Diag(ParamLoc, 1061 diag::ext_template_parameter_default_in_function_template) 1062 << DefArgRange; 1063 return false; 1064 1065 case Sema::TPC_ClassTemplateMember: 1066 // C++0x [temp.param]p9: 1067 // A default template-argument shall not be specified in the 1068 // template-parameter-lists of the definition of a member of a 1069 // class template that appears outside of the member's class. 1070 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member) 1071 << DefArgRange; 1072 return true; 1073 1074 case Sema::TPC_FriendFunctionTemplate: 1075 // C++ [temp.param]p9: 1076 // A default template-argument shall not be specified in a 1077 // friend template declaration. 1078 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template) 1079 << DefArgRange; 1080 return true; 1081 1082 // FIXME: C++0x [temp.param]p9 allows default template-arguments 1083 // for friend function templates if there is only a single 1084 // declaration (and it is a definition). Strange! 1085 } 1086 1087 return false; 1088} 1089 1090/// \brief Check for unexpanded parameter packs within the template parameters 1091/// of a template template parameter, recursively. 1092bool DiagnoseUnexpandedParameterPacks(Sema &S, TemplateTemplateParmDecl *TTP){ 1093 TemplateParameterList *Params = TTP->getTemplateParameters(); 1094 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 1095 NamedDecl *P = Params->getParam(I); 1096 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) { 1097 if (S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(), 1098 NTTP->getTypeSourceInfo(), 1099 Sema::UPPC_NonTypeTemplateParameterType)) 1100 return true; 1101 1102 continue; 1103 } 1104 1105 if (TemplateTemplateParmDecl *InnerTTP 1106 = dyn_cast<TemplateTemplateParmDecl>(P)) 1107 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP)) 1108 return true; 1109 } 1110 1111 return false; 1112} 1113 1114/// \brief Checks the validity of a template parameter list, possibly 1115/// considering the template parameter list from a previous 1116/// declaration. 1117/// 1118/// If an "old" template parameter list is provided, it must be 1119/// equivalent (per TemplateParameterListsAreEqual) to the "new" 1120/// template parameter list. 1121/// 1122/// \param NewParams Template parameter list for a new template 1123/// declaration. This template parameter list will be updated with any 1124/// default arguments that are carried through from the previous 1125/// template parameter list. 1126/// 1127/// \param OldParams If provided, template parameter list from a 1128/// previous declaration of the same template. Default template 1129/// arguments will be merged from the old template parameter list to 1130/// the new template parameter list. 1131/// 1132/// \param TPC Describes the context in which we are checking the given 1133/// template parameter list. 1134/// 1135/// \returns true if an error occurred, false otherwise. 1136bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams, 1137 TemplateParameterList *OldParams, 1138 TemplateParamListContext TPC) { 1139 bool Invalid = false; 1140 1141 // C++ [temp.param]p10: 1142 // The set of default template-arguments available for use with a 1143 // template declaration or definition is obtained by merging the 1144 // default arguments from the definition (if in scope) and all 1145 // declarations in scope in the same way default function 1146 // arguments are (8.3.6). 1147 bool SawDefaultArgument = false; 1148 SourceLocation PreviousDefaultArgLoc; 1149 1150 bool SawParameterPack = false; 1151 SourceLocation ParameterPackLoc; 1152 1153 // Dummy initialization to avoid warnings. 1154 TemplateParameterList::iterator OldParam = NewParams->end(); 1155 if (OldParams) 1156 OldParam = OldParams->begin(); 1157 1158 bool RemoveDefaultArguments = false; 1159 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 1160 NewParamEnd = NewParams->end(); 1161 NewParam != NewParamEnd; ++NewParam) { 1162 // Variables used to diagnose redundant default arguments 1163 bool RedundantDefaultArg = false; 1164 SourceLocation OldDefaultLoc; 1165 SourceLocation NewDefaultLoc; 1166 1167 // Variables used to diagnose missing default arguments 1168 bool MissingDefaultArg = false; 1169 1170 // C++0x [temp.param]p11: 1171 // If a template parameter of a primary class template is a template 1172 // parameter pack, it shall be the last template parameter. 1173 if (SawParameterPack && TPC == TPC_ClassTemplate) { 1174 Diag(ParameterPackLoc, 1175 diag::err_template_param_pack_must_be_last_template_parameter); 1176 Invalid = true; 1177 } 1178 1179 if (TemplateTypeParmDecl *NewTypeParm 1180 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) { 1181 // Check the presence of a default argument here. 1182 if (NewTypeParm->hasDefaultArgument() && 1183 DiagnoseDefaultTemplateArgument(*this, TPC, 1184 NewTypeParm->getLocation(), 1185 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc() 1186 .getSourceRange())) 1187 NewTypeParm->removeDefaultArgument(); 1188 1189 // Merge default arguments for template type parameters. 1190 TemplateTypeParmDecl *OldTypeParm 1191 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : 0; 1192 1193 if (NewTypeParm->isParameterPack()) { 1194 assert(!NewTypeParm->hasDefaultArgument() && 1195 "Parameter packs can't have a default argument!"); 1196 SawParameterPack = true; 1197 ParameterPackLoc = NewTypeParm->getLocation(); 1198 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() && 1199 NewTypeParm->hasDefaultArgument()) { 1200 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc(); 1201 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc(); 1202 SawDefaultArgument = true; 1203 RedundantDefaultArg = true; 1204 PreviousDefaultArgLoc = NewDefaultLoc; 1205 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) { 1206 // Merge the default argument from the old declaration to the 1207 // new declaration. 1208 SawDefaultArgument = true; 1209 NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(), 1210 true); 1211 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc(); 1212 } else if (NewTypeParm->hasDefaultArgument()) { 1213 SawDefaultArgument = true; 1214 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc(); 1215 } else if (SawDefaultArgument) 1216 MissingDefaultArg = true; 1217 } else if (NonTypeTemplateParmDecl *NewNonTypeParm 1218 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) { 1219 // Check for unexpanded parameter packs. 1220 if (DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(), 1221 NewNonTypeParm->getTypeSourceInfo(), 1222 UPPC_NonTypeTemplateParameterType)) { 1223 Invalid = true; 1224 continue; 1225 } 1226 1227 // Check the presence of a default argument here. 1228 if (NewNonTypeParm->hasDefaultArgument() && 1229 DiagnoseDefaultTemplateArgument(*this, TPC, 1230 NewNonTypeParm->getLocation(), 1231 NewNonTypeParm->getDefaultArgument()->getSourceRange())) { 1232 NewNonTypeParm->removeDefaultArgument(); 1233 } 1234 1235 // Merge default arguments for non-type template parameters 1236 NonTypeTemplateParmDecl *OldNonTypeParm 1237 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : 0; 1238 if (NewNonTypeParm->isParameterPack()) { 1239 assert(!NewNonTypeParm->hasDefaultArgument() && 1240 "Parameter packs can't have a default argument!"); 1241 SawParameterPack = true; 1242 ParameterPackLoc = NewNonTypeParm->getLocation(); 1243 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() && 1244 NewNonTypeParm->hasDefaultArgument()) { 1245 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1246 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1247 SawDefaultArgument = true; 1248 RedundantDefaultArg = true; 1249 PreviousDefaultArgLoc = NewDefaultLoc; 1250 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) { 1251 // Merge the default argument from the old declaration to the 1252 // new declaration. 1253 SawDefaultArgument = true; 1254 // FIXME: We need to create a new kind of "default argument" 1255 // expression that points to a previous non-type template 1256 // parameter. 1257 NewNonTypeParm->setDefaultArgument( 1258 OldNonTypeParm->getDefaultArgument(), 1259 /*Inherited=*/ true); 1260 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1261 } else if (NewNonTypeParm->hasDefaultArgument()) { 1262 SawDefaultArgument = true; 1263 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1264 } else if (SawDefaultArgument) 1265 MissingDefaultArg = true; 1266 } else { 1267 // Check the presence of a default argument here. 1268 TemplateTemplateParmDecl *NewTemplateParm 1269 = cast<TemplateTemplateParmDecl>(*NewParam); 1270 1271 // Check for unexpanded parameter packs, recursively. 1272 if (DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) { 1273 Invalid = true; 1274 continue; 1275 } 1276 1277 if (NewTemplateParm->hasDefaultArgument() && 1278 DiagnoseDefaultTemplateArgument(*this, TPC, 1279 NewTemplateParm->getLocation(), 1280 NewTemplateParm->getDefaultArgument().getSourceRange())) 1281 NewTemplateParm->removeDefaultArgument(); 1282 1283 // Merge default arguments for template template parameters 1284 TemplateTemplateParmDecl *OldTemplateParm 1285 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : 0; 1286 if (NewTemplateParm->isParameterPack()) { 1287 assert(!NewTemplateParm->hasDefaultArgument() && 1288 "Parameter packs can't have a default argument!"); 1289 SawParameterPack = true; 1290 ParameterPackLoc = NewTemplateParm->getLocation(); 1291 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() && 1292 NewTemplateParm->hasDefaultArgument()) { 1293 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation(); 1294 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation(); 1295 SawDefaultArgument = true; 1296 RedundantDefaultArg = true; 1297 PreviousDefaultArgLoc = NewDefaultLoc; 1298 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) { 1299 // Merge the default argument from the old declaration to the 1300 // new declaration. 1301 SawDefaultArgument = true; 1302 // FIXME: We need to create a new kind of "default argument" expression 1303 // that points to a previous template template parameter. 1304 NewTemplateParm->setDefaultArgument( 1305 OldTemplateParm->getDefaultArgument(), 1306 /*Inherited=*/ true); 1307 PreviousDefaultArgLoc 1308 = OldTemplateParm->getDefaultArgument().getLocation(); 1309 } else if (NewTemplateParm->hasDefaultArgument()) { 1310 SawDefaultArgument = true; 1311 PreviousDefaultArgLoc 1312 = NewTemplateParm->getDefaultArgument().getLocation(); 1313 } else if (SawDefaultArgument) 1314 MissingDefaultArg = true; 1315 } 1316 1317 if (RedundantDefaultArg) { 1318 // C++ [temp.param]p12: 1319 // A template-parameter shall not be given default arguments 1320 // by two different declarations in the same scope. 1321 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition); 1322 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg); 1323 Invalid = true; 1324 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) { 1325 // C++ [temp.param]p11: 1326 // If a template-parameter of a class template has a default 1327 // template-argument, each subsequent template-parameter shall either 1328 // have a default template-argument supplied or be a template parameter 1329 // pack. 1330 Diag((*NewParam)->getLocation(), 1331 diag::err_template_param_default_arg_missing); 1332 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg); 1333 Invalid = true; 1334 RemoveDefaultArguments = true; 1335 } 1336 1337 // If we have an old template parameter list that we're merging 1338 // in, move on to the next parameter. 1339 if (OldParams) 1340 ++OldParam; 1341 } 1342 1343 // We were missing some default arguments at the end of the list, so remove 1344 // all of the default arguments. 1345 if (RemoveDefaultArguments) { 1346 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 1347 NewParamEnd = NewParams->end(); 1348 NewParam != NewParamEnd; ++NewParam) { 1349 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam)) 1350 TTP->removeDefaultArgument(); 1351 else if (NonTypeTemplateParmDecl *NTTP 1352 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) 1353 NTTP->removeDefaultArgument(); 1354 else 1355 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument(); 1356 } 1357 } 1358 1359 return Invalid; 1360} 1361 1362namespace { 1363 1364/// A class which looks for a use of a certain level of template 1365/// parameter. 1366struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> { 1367 typedef RecursiveASTVisitor<DependencyChecker> super; 1368 1369 unsigned Depth; 1370 bool Match; 1371 1372 DependencyChecker(TemplateParameterList *Params) : Match(false) { 1373 NamedDecl *ND = Params->getParam(0); 1374 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) { 1375 Depth = PD->getDepth(); 1376 } else if (NonTypeTemplateParmDecl *PD = 1377 dyn_cast<NonTypeTemplateParmDecl>(ND)) { 1378 Depth = PD->getDepth(); 1379 } else { 1380 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth(); 1381 } 1382 } 1383 1384 bool Matches(unsigned ParmDepth) { 1385 if (ParmDepth >= Depth) { 1386 Match = true; 1387 return true; 1388 } 1389 return false; 1390 } 1391 1392 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) { 1393 return !Matches(T->getDepth()); 1394 } 1395 1396 bool TraverseTemplateName(TemplateName N) { 1397 if (TemplateTemplateParmDecl *PD = 1398 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl())) 1399 if (Matches(PD->getDepth())) return false; 1400 return super::TraverseTemplateName(N); 1401 } 1402 1403 bool VisitDeclRefExpr(DeclRefExpr *E) { 1404 if (NonTypeTemplateParmDecl *PD = 1405 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) { 1406 if (PD->getDepth() == Depth) { 1407 Match = true; 1408 return false; 1409 } 1410 } 1411 return super::VisitDeclRefExpr(E); 1412 } 1413}; 1414} 1415 1416/// Determines whether a template-id depends on the given parameter 1417/// list. 1418static bool 1419DependsOnTemplateParameters(const TemplateSpecializationType *TemplateId, 1420 TemplateParameterList *Params) { 1421 DependencyChecker Checker(Params); 1422 Checker.TraverseType(QualType(TemplateId, 0)); 1423 return Checker.Match; 1424} 1425 1426/// \brief Match the given template parameter lists to the given scope 1427/// specifier, returning the template parameter list that applies to the 1428/// name. 1429/// 1430/// \param DeclStartLoc the start of the declaration that has a scope 1431/// specifier or a template parameter list. 1432/// 1433/// \param SS the scope specifier that will be matched to the given template 1434/// parameter lists. This scope specifier precedes a qualified name that is 1435/// being declared. 1436/// 1437/// \param ParamLists the template parameter lists, from the outermost to the 1438/// innermost template parameter lists. 1439/// 1440/// \param NumParamLists the number of template parameter lists in ParamLists. 1441/// 1442/// \param IsFriend Whether to apply the slightly different rules for 1443/// matching template parameters to scope specifiers in friend 1444/// declarations. 1445/// 1446/// \param IsExplicitSpecialization will be set true if the entity being 1447/// declared is an explicit specialization, false otherwise. 1448/// 1449/// \returns the template parameter list, if any, that corresponds to the 1450/// name that is preceded by the scope specifier @p SS. This template 1451/// parameter list may be have template parameters (if we're declaring a 1452/// template) or may have no template parameters (if we're declaring a 1453/// template specialization), or may be NULL (if we were's declaring isn't 1454/// itself a template). 1455TemplateParameterList * 1456Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc, 1457 const CXXScopeSpec &SS, 1458 TemplateParameterList **ParamLists, 1459 unsigned NumParamLists, 1460 bool IsFriend, 1461 bool &IsExplicitSpecialization, 1462 bool &Invalid) { 1463 IsExplicitSpecialization = false; 1464 1465 // Find the template-ids that occur within the nested-name-specifier. These 1466 // template-ids will match up with the template parameter lists. 1467 llvm::SmallVector<const TemplateSpecializationType *, 4> 1468 TemplateIdsInSpecifier; 1469 llvm::SmallVector<ClassTemplateSpecializationDecl *, 4> 1470 ExplicitSpecializationsInSpecifier; 1471 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 1472 NNS; NNS = NNS->getPrefix()) { 1473 const Type *T = NNS->getAsType(); 1474 if (!T) break; 1475 1476 // C++0x [temp.expl.spec]p17: 1477 // A member or a member template may be nested within many 1478 // enclosing class templates. In an explicit specialization for 1479 // such a member, the member declaration shall be preceded by a 1480 // template<> for each enclosing class template that is 1481 // explicitly specialized. 1482 // 1483 // Following the existing practice of GNU and EDG, we allow a typedef of a 1484 // template specialization type. 1485 while (const TypedefType *TT = dyn_cast<TypedefType>(T)) 1486 T = TT->getDecl()->getUnderlyingType().getTypePtr(); 1487 1488 if (const TemplateSpecializationType *SpecType 1489 = dyn_cast<TemplateSpecializationType>(T)) { 1490 TemplateDecl *Template = SpecType->getTemplateName().getAsTemplateDecl(); 1491 if (!Template) 1492 continue; // FIXME: should this be an error? probably... 1493 1494 if (const RecordType *Record = SpecType->getAs<RecordType>()) { 1495 ClassTemplateSpecializationDecl *SpecDecl 1496 = cast<ClassTemplateSpecializationDecl>(Record->getDecl()); 1497 // If the nested name specifier refers to an explicit specialization, 1498 // we don't need a template<> header. 1499 if (SpecDecl->getSpecializationKind() == TSK_ExplicitSpecialization) { 1500 ExplicitSpecializationsInSpecifier.push_back(SpecDecl); 1501 continue; 1502 } 1503 } 1504 1505 TemplateIdsInSpecifier.push_back(SpecType); 1506 } 1507 } 1508 1509 // Reverse the list of template-ids in the scope specifier, so that we can 1510 // more easily match up the template-ids and the template parameter lists. 1511 std::reverse(TemplateIdsInSpecifier.begin(), TemplateIdsInSpecifier.end()); 1512 1513 SourceLocation FirstTemplateLoc = DeclStartLoc; 1514 if (NumParamLists) 1515 FirstTemplateLoc = ParamLists[0]->getTemplateLoc(); 1516 1517 // Match the template-ids found in the specifier to the template parameter 1518 // lists. 1519 unsigned ParamIdx = 0, TemplateIdx = 0; 1520 for (unsigned NumTemplateIds = TemplateIdsInSpecifier.size(); 1521 TemplateIdx != NumTemplateIds; ++TemplateIdx) { 1522 const TemplateSpecializationType *TemplateId 1523 = TemplateIdsInSpecifier[TemplateIdx]; 1524 bool DependentTemplateId = TemplateId->isDependentType(); 1525 1526 // In friend declarations we can have template-ids which don't 1527 // depend on the corresponding template parameter lists. But 1528 // assume that empty parameter lists are supposed to match this 1529 // template-id. 1530 if (IsFriend && ParamIdx < NumParamLists && ParamLists[ParamIdx]->size()) { 1531 if (!DependentTemplateId || 1532 !DependsOnTemplateParameters(TemplateId, ParamLists[ParamIdx])) 1533 continue; 1534 } 1535 1536 if (ParamIdx >= NumParamLists) { 1537 // We have a template-id without a corresponding template parameter 1538 // list. 1539 1540 // ...which is fine if this is a friend declaration. 1541 if (IsFriend) { 1542 IsExplicitSpecialization = true; 1543 break; 1544 } 1545 1546 if (DependentTemplateId) { 1547 // FIXME: the location information here isn't great. 1548 Diag(SS.getRange().getBegin(), 1549 diag::err_template_spec_needs_template_parameters) 1550 << QualType(TemplateId, 0) 1551 << SS.getRange(); 1552 Invalid = true; 1553 } else { 1554 Diag(SS.getRange().getBegin(), diag::err_template_spec_needs_header) 1555 << SS.getRange() 1556 << FixItHint::CreateInsertion(FirstTemplateLoc, "template<> "); 1557 IsExplicitSpecialization = true; 1558 } 1559 return 0; 1560 } 1561 1562 // Check the template parameter list against its corresponding template-id. 1563 if (DependentTemplateId) { 1564 TemplateParameterList *ExpectedTemplateParams = 0; 1565 1566 // Are there cases in (e.g.) friends where this won't match? 1567 if (const InjectedClassNameType *Injected 1568 = TemplateId->getAs<InjectedClassNameType>()) { 1569 CXXRecordDecl *Record = Injected->getDecl(); 1570 if (ClassTemplatePartialSpecializationDecl *Partial = 1571 dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) 1572 ExpectedTemplateParams = Partial->getTemplateParameters(); 1573 else 1574 ExpectedTemplateParams = Record->getDescribedClassTemplate() 1575 ->getTemplateParameters(); 1576 } 1577 1578 if (ExpectedTemplateParams) 1579 TemplateParameterListsAreEqual(ParamLists[ParamIdx], 1580 ExpectedTemplateParams, 1581 true, TPL_TemplateMatch); 1582 1583 CheckTemplateParameterList(ParamLists[ParamIdx], 0, 1584 TPC_ClassTemplateMember); 1585 } else if (ParamLists[ParamIdx]->size() > 0) 1586 Diag(ParamLists[ParamIdx]->getTemplateLoc(), 1587 diag::err_template_param_list_matches_nontemplate) 1588 << TemplateId 1589 << ParamLists[ParamIdx]->getSourceRange(); 1590 else 1591 IsExplicitSpecialization = true; 1592 1593 ++ParamIdx; 1594 } 1595 1596 // If there were at least as many template-ids as there were template 1597 // parameter lists, then there are no template parameter lists remaining for 1598 // the declaration itself. 1599 if (ParamIdx >= NumParamLists) 1600 return 0; 1601 1602 // If there were too many template parameter lists, complain about that now. 1603 if (ParamIdx != NumParamLists - 1) { 1604 while (ParamIdx < NumParamLists - 1) { 1605 bool isExplicitSpecHeader = ParamLists[ParamIdx]->size() == 0; 1606 Diag(ParamLists[ParamIdx]->getTemplateLoc(), 1607 isExplicitSpecHeader? diag::warn_template_spec_extra_headers 1608 : diag::err_template_spec_extra_headers) 1609 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(), 1610 ParamLists[ParamIdx]->getRAngleLoc()); 1611 1612 if (isExplicitSpecHeader && !ExplicitSpecializationsInSpecifier.empty()) { 1613 Diag(ExplicitSpecializationsInSpecifier.back()->getLocation(), 1614 diag::note_explicit_template_spec_does_not_need_header) 1615 << ExplicitSpecializationsInSpecifier.back(); 1616 ExplicitSpecializationsInSpecifier.pop_back(); 1617 } 1618 1619 // We have a template parameter list with no corresponding scope, which 1620 // means that the resulting template declaration can't be instantiated 1621 // properly (we'll end up with dependent nodes when we shouldn't). 1622 if (!isExplicitSpecHeader) 1623 Invalid = true; 1624 1625 ++ParamIdx; 1626 } 1627 } 1628 1629 // Return the last template parameter list, which corresponds to the 1630 // entity being declared. 1631 return ParamLists[NumParamLists - 1]; 1632} 1633 1634QualType Sema::CheckTemplateIdType(TemplateName Name, 1635 SourceLocation TemplateLoc, 1636 const TemplateArgumentListInfo &TemplateArgs) { 1637 TemplateDecl *Template = Name.getAsTemplateDecl(); 1638 if (!Template) { 1639 // The template name does not resolve to a template, so we just 1640 // build a dependent template-id type. 1641 return Context.getTemplateSpecializationType(Name, TemplateArgs); 1642 } 1643 1644 // Check that the template argument list is well-formed for this 1645 // template. 1646 llvm::SmallVector<TemplateArgument, 4> Converted; 1647 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs, 1648 false, Converted)) 1649 return QualType(); 1650 1651 assert((Converted.size() == Template->getTemplateParameters()->size()) && 1652 "Converted template argument list is too short!"); 1653 1654 QualType CanonType; 1655 1656 if (Name.isDependent() || 1657 TemplateSpecializationType::anyDependentTemplateArguments( 1658 TemplateArgs)) { 1659 // This class template specialization is a dependent 1660 // type. Therefore, its canonical type is another class template 1661 // specialization type that contains all of the converted 1662 // arguments in canonical form. This ensures that, e.g., A<T> and 1663 // A<T, T> have identical types when A is declared as: 1664 // 1665 // template<typename T, typename U = T> struct A; 1666 TemplateName CanonName = Context.getCanonicalTemplateName(Name); 1667 CanonType = Context.getTemplateSpecializationType(CanonName, 1668 Converted.data(), 1669 Converted.size()); 1670 1671 // FIXME: CanonType is not actually the canonical type, and unfortunately 1672 // it is a TemplateSpecializationType that we will never use again. 1673 // In the future, we need to teach getTemplateSpecializationType to only 1674 // build the canonical type and return that to us. 1675 CanonType = Context.getCanonicalType(CanonType); 1676 1677 // This might work out to be a current instantiation, in which 1678 // case the canonical type needs to be the InjectedClassNameType. 1679 // 1680 // TODO: in theory this could be a simple hashtable lookup; most 1681 // changes to CurContext don't change the set of current 1682 // instantiations. 1683 if (isa<ClassTemplateDecl>(Template)) { 1684 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { 1685 // If we get out to a namespace, we're done. 1686 if (Ctx->isFileContext()) break; 1687 1688 // If this isn't a record, keep looking. 1689 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx); 1690 if (!Record) continue; 1691 1692 // Look for one of the two cases with InjectedClassNameTypes 1693 // and check whether it's the same template. 1694 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) && 1695 !Record->getDescribedClassTemplate()) 1696 continue; 1697 1698 // Fetch the injected class name type and check whether its 1699 // injected type is equal to the type we just built. 1700 QualType ICNT = Context.getTypeDeclType(Record); 1701 QualType Injected = cast<InjectedClassNameType>(ICNT) 1702 ->getInjectedSpecializationType(); 1703 1704 if (CanonType != Injected->getCanonicalTypeInternal()) 1705 continue; 1706 1707 // If so, the canonical type of this TST is the injected 1708 // class name type of the record we just found. 1709 assert(ICNT.isCanonical()); 1710 CanonType = ICNT; 1711 break; 1712 } 1713 } 1714 } else if (ClassTemplateDecl *ClassTemplate 1715 = dyn_cast<ClassTemplateDecl>(Template)) { 1716 // Find the class template specialization declaration that 1717 // corresponds to these arguments. 1718 void *InsertPos = 0; 1719 ClassTemplateSpecializationDecl *Decl 1720 = ClassTemplate->findSpecialization(Converted.data(), Converted.size(), 1721 InsertPos); 1722 if (!Decl) { 1723 // This is the first time we have referenced this class template 1724 // specialization. Create the canonical declaration and add it to 1725 // the set of specializations. 1726 Decl = ClassTemplateSpecializationDecl::Create(Context, 1727 ClassTemplate->getTemplatedDecl()->getTagKind(), 1728 ClassTemplate->getDeclContext(), 1729 ClassTemplate->getLocation(), 1730 ClassTemplate, 1731 Converted.data(), 1732 Converted.size(), 0); 1733 ClassTemplate->AddSpecialization(Decl, InsertPos); 1734 Decl->setLexicalDeclContext(CurContext); 1735 } 1736 1737 CanonType = Context.getTypeDeclType(Decl); 1738 assert(isa<RecordType>(CanonType) && 1739 "type of non-dependent specialization is not a RecordType"); 1740 } 1741 1742 // Build the fully-sugared type for this class template 1743 // specialization, which refers back to the class template 1744 // specialization we created or found. 1745 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType); 1746} 1747 1748TypeResult 1749Sema::ActOnTemplateIdType(TemplateTy TemplateD, SourceLocation TemplateLoc, 1750 SourceLocation LAngleLoc, 1751 ASTTemplateArgsPtr TemplateArgsIn, 1752 SourceLocation RAngleLoc) { 1753 TemplateName Template = TemplateD.getAsVal<TemplateName>(); 1754 1755 // Translate the parser's template argument list in our AST format. 1756 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 1757 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 1758 1759 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); 1760 TemplateArgsIn.release(); 1761 1762 if (Result.isNull()) 1763 return true; 1764 1765 TypeSourceInfo *DI = Context.CreateTypeSourceInfo(Result); 1766 TemplateSpecializationTypeLoc TL 1767 = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc()); 1768 TL.setTemplateNameLoc(TemplateLoc); 1769 TL.setLAngleLoc(LAngleLoc); 1770 TL.setRAngleLoc(RAngleLoc); 1771 for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i) 1772 TL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 1773 1774 return CreateParsedType(Result, DI); 1775} 1776 1777TypeResult Sema::ActOnTagTemplateIdType(CXXScopeSpec &SS, 1778 TypeResult TypeResult, 1779 TagUseKind TUK, 1780 TypeSpecifierType TagSpec, 1781 SourceLocation TagLoc) { 1782 if (TypeResult.isInvalid()) 1783 return ::TypeResult(); 1784 1785 TypeSourceInfo *DI; 1786 QualType Type = GetTypeFromParser(TypeResult.get(), &DI); 1787 1788 // Verify the tag specifier. 1789 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 1790 1791 if (const RecordType *RT = Type->getAs<RecordType>()) { 1792 RecordDecl *D = RT->getDecl(); 1793 1794 IdentifierInfo *Id = D->getIdentifier(); 1795 assert(Id && "templated class must have an identifier"); 1796 1797 if (!isAcceptableTagRedeclaration(D, TagKind, TagLoc, *Id)) { 1798 Diag(TagLoc, diag::err_use_with_wrong_tag) 1799 << Type 1800 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName()); 1801 Diag(D->getLocation(), diag::note_previous_use); 1802 } 1803 } 1804 1805 ElaboratedTypeKeyword Keyword 1806 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind); 1807 QualType ElabType = Context.getElaboratedType(Keyword, /*NNS=*/0, Type); 1808 1809 TypeSourceInfo *ElabDI = Context.CreateTypeSourceInfo(ElabType); 1810 ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(ElabDI->getTypeLoc()); 1811 TL.setKeywordLoc(TagLoc); 1812 TL.setQualifierRange(SS.getRange()); 1813 TL.getNamedTypeLoc().initializeFullCopy(DI->getTypeLoc()); 1814 return CreateParsedType(ElabType, ElabDI); 1815} 1816 1817ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, 1818 LookupResult &R, 1819 bool RequiresADL, 1820 const TemplateArgumentListInfo &TemplateArgs) { 1821 // FIXME: Can we do any checking at this point? I guess we could check the 1822 // template arguments that we have against the template name, if the template 1823 // name refers to a single template. That's not a terribly common case, 1824 // though. 1825 // foo<int> could identify a single function unambiguously 1826 // This approach does NOT work, since f<int>(1); 1827 // gets resolved prior to resorting to overload resolution 1828 // i.e., template<class T> void f(double); 1829 // vs template<class T, class U> void f(U); 1830 1831 // These should be filtered out by our callers. 1832 assert(!R.empty() && "empty lookup results when building templateid"); 1833 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid"); 1834 1835 NestedNameSpecifier *Qualifier = 0; 1836 SourceRange QualifierRange; 1837 if (SS.isSet()) { 1838 Qualifier = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 1839 QualifierRange = SS.getRange(); 1840 } 1841 1842 // We don't want lookup warnings at this point. 1843 R.suppressDiagnostics(); 1844 1845 UnresolvedLookupExpr *ULE 1846 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), 1847 Qualifier, QualifierRange, 1848 R.getLookupNameInfo(), 1849 RequiresADL, TemplateArgs, 1850 R.begin(), R.end()); 1851 1852 return Owned(ULE); 1853} 1854 1855// We actually only call this from template instantiation. 1856ExprResult 1857Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, 1858 const DeclarationNameInfo &NameInfo, 1859 const TemplateArgumentListInfo &TemplateArgs) { 1860 DeclContext *DC; 1861 if (!(DC = computeDeclContext(SS, false)) || 1862 DC->isDependentContext() || 1863 RequireCompleteDeclContext(SS, DC)) 1864 return BuildDependentDeclRefExpr(SS, NameInfo, &TemplateArgs); 1865 1866 bool MemberOfUnknownSpecialization; 1867 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1868 LookupTemplateName(R, (Scope*) 0, SS, QualType(), /*Entering*/ false, 1869 MemberOfUnknownSpecialization); 1870 1871 if (R.isAmbiguous()) 1872 return ExprError(); 1873 1874 if (R.empty()) { 1875 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template) 1876 << NameInfo.getName() << SS.getRange(); 1877 return ExprError(); 1878 } 1879 1880 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) { 1881 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template) 1882 << (NestedNameSpecifier*) SS.getScopeRep() 1883 << NameInfo.getName() << SS.getRange(); 1884 Diag(Temp->getLocation(), diag::note_referenced_class_template); 1885 return ExprError(); 1886 } 1887 1888 return BuildTemplateIdExpr(SS, R, /* ADL */ false, TemplateArgs); 1889} 1890 1891/// \brief Form a dependent template name. 1892/// 1893/// This action forms a dependent template name given the template 1894/// name and its (presumably dependent) scope specifier. For 1895/// example, given "MetaFun::template apply", the scope specifier \p 1896/// SS will be "MetaFun::", \p TemplateKWLoc contains the location 1897/// of the "template" keyword, and "apply" is the \p Name. 1898TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S, 1899 SourceLocation TemplateKWLoc, 1900 CXXScopeSpec &SS, 1901 UnqualifiedId &Name, 1902 ParsedType ObjectType, 1903 bool EnteringContext, 1904 TemplateTy &Result) { 1905 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent() && 1906 !getLangOptions().CPlusPlus0x) 1907 Diag(TemplateKWLoc, diag::ext_template_outside_of_template) 1908 << FixItHint::CreateRemoval(TemplateKWLoc); 1909 1910 DeclContext *LookupCtx = 0; 1911 if (SS.isSet()) 1912 LookupCtx = computeDeclContext(SS, EnteringContext); 1913 if (!LookupCtx && ObjectType) 1914 LookupCtx = computeDeclContext(ObjectType.get()); 1915 if (LookupCtx) { 1916 // C++0x [temp.names]p5: 1917 // If a name prefixed by the keyword template is not the name of 1918 // a template, the program is ill-formed. [Note: the keyword 1919 // template may not be applied to non-template members of class 1920 // templates. -end note ] [ Note: as is the case with the 1921 // typename prefix, the template prefix is allowed in cases 1922 // where it is not strictly necessary; i.e., when the 1923 // nested-name-specifier or the expression on the left of the -> 1924 // or . is not dependent on a template-parameter, or the use 1925 // does not appear in the scope of a template. -end note] 1926 // 1927 // Note: C++03 was more strict here, because it banned the use of 1928 // the "template" keyword prior to a template-name that was not a 1929 // dependent name. C++ DR468 relaxed this requirement (the 1930 // "template" keyword is now permitted). We follow the C++0x 1931 // rules, even in C++03 mode with a warning, retroactively applying the DR. 1932 bool MemberOfUnknownSpecialization; 1933 TemplateNameKind TNK = isTemplateName(0, SS, TemplateKWLoc.isValid(), Name, 1934 ObjectType, EnteringContext, Result, 1935 MemberOfUnknownSpecialization); 1936 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() && 1937 isa<CXXRecordDecl>(LookupCtx) && 1938 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()) { 1939 // This is a dependent template. Handle it below. 1940 } else if (TNK == TNK_Non_template) { 1941 Diag(Name.getSourceRange().getBegin(), 1942 diag::err_template_kw_refers_to_non_template) 1943 << GetNameFromUnqualifiedId(Name).getName() 1944 << Name.getSourceRange() 1945 << TemplateKWLoc; 1946 return TNK_Non_template; 1947 } else { 1948 // We found something; return it. 1949 return TNK; 1950 } 1951 } 1952 1953 NestedNameSpecifier *Qualifier 1954 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 1955 1956 switch (Name.getKind()) { 1957 case UnqualifiedId::IK_Identifier: 1958 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1959 Name.Identifier)); 1960 return TNK_Dependent_template_name; 1961 1962 case UnqualifiedId::IK_OperatorFunctionId: 1963 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1964 Name.OperatorFunctionId.Operator)); 1965 return TNK_Dependent_template_name; 1966 1967 case UnqualifiedId::IK_LiteralOperatorId: 1968 assert(false && "We don't support these; Parse shouldn't have allowed propagation"); 1969 1970 default: 1971 break; 1972 } 1973 1974 Diag(Name.getSourceRange().getBegin(), 1975 diag::err_template_kw_refers_to_non_template) 1976 << GetNameFromUnqualifiedId(Name).getName() 1977 << Name.getSourceRange() 1978 << TemplateKWLoc; 1979 return TNK_Non_template; 1980} 1981 1982bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, 1983 const TemplateArgumentLoc &AL, 1984 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 1985 const TemplateArgument &Arg = AL.getArgument(); 1986 1987 // Check template type parameter. 1988 switch(Arg.getKind()) { 1989 case TemplateArgument::Type: 1990 // C++ [temp.arg.type]p1: 1991 // A template-argument for a template-parameter which is a 1992 // type shall be a type-id. 1993 break; 1994 case TemplateArgument::Template: { 1995 // We have a template type parameter but the template argument 1996 // is a template without any arguments. 1997 SourceRange SR = AL.getSourceRange(); 1998 TemplateName Name = Arg.getAsTemplate(); 1999 Diag(SR.getBegin(), diag::err_template_missing_args) 2000 << Name << SR; 2001 if (TemplateDecl *Decl = Name.getAsTemplateDecl()) 2002 Diag(Decl->getLocation(), diag::note_template_decl_here); 2003 2004 return true; 2005 } 2006 default: { 2007 // We have a template type parameter but the template argument 2008 // is not a type. 2009 SourceRange SR = AL.getSourceRange(); 2010 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; 2011 Diag(Param->getLocation(), diag::note_template_param_here); 2012 2013 return true; 2014 } 2015 } 2016 2017 if (CheckTemplateArgument(Param, AL.getTypeSourceInfo())) 2018 return true; 2019 2020 // Add the converted template type argument. 2021 Converted.push_back( 2022 TemplateArgument(Context.getCanonicalType(Arg.getAsType()))); 2023 return false; 2024} 2025 2026/// \brief Substitute template arguments into the default template argument for 2027/// the given template type parameter. 2028/// 2029/// \param SemaRef the semantic analysis object for which we are performing 2030/// the substitution. 2031/// 2032/// \param Template the template that we are synthesizing template arguments 2033/// for. 2034/// 2035/// \param TemplateLoc the location of the template name that started the 2036/// template-id we are checking. 2037/// 2038/// \param RAngleLoc the location of the right angle bracket ('>') that 2039/// terminates the template-id. 2040/// 2041/// \param Param the template template parameter whose default we are 2042/// substituting into. 2043/// 2044/// \param Converted the list of template arguments provided for template 2045/// parameters that precede \p Param in the template parameter list. 2046/// 2047/// \returns the substituted template argument, or NULL if an error occurred. 2048static TypeSourceInfo * 2049SubstDefaultTemplateArgument(Sema &SemaRef, 2050 TemplateDecl *Template, 2051 SourceLocation TemplateLoc, 2052 SourceLocation RAngleLoc, 2053 TemplateTypeParmDecl *Param, 2054 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 2055 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo(); 2056 2057 // If the argument type is dependent, instantiate it now based 2058 // on the previously-computed template arguments. 2059 if (ArgType->getType()->isDependentType()) { 2060 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2061 Converted.data(), Converted.size()); 2062 2063 MultiLevelTemplateArgumentList AllTemplateArgs 2064 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 2065 2066 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 2067 Template, Converted.data(), 2068 Converted.size(), 2069 SourceRange(TemplateLoc, RAngleLoc)); 2070 2071 ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs, 2072 Param->getDefaultArgumentLoc(), 2073 Param->getDeclName()); 2074 } 2075 2076 return ArgType; 2077} 2078 2079/// \brief Substitute template arguments into the default template argument for 2080/// the given non-type template parameter. 2081/// 2082/// \param SemaRef the semantic analysis object for which we are performing 2083/// the substitution. 2084/// 2085/// \param Template the template that we are synthesizing template arguments 2086/// for. 2087/// 2088/// \param TemplateLoc the location of the template name that started the 2089/// template-id we are checking. 2090/// 2091/// \param RAngleLoc the location of the right angle bracket ('>') that 2092/// terminates the template-id. 2093/// 2094/// \param Param the non-type template parameter whose default we are 2095/// substituting into. 2096/// 2097/// \param Converted the list of template arguments provided for template 2098/// parameters that precede \p Param in the template parameter list. 2099/// 2100/// \returns the substituted template argument, or NULL if an error occurred. 2101static ExprResult 2102SubstDefaultTemplateArgument(Sema &SemaRef, 2103 TemplateDecl *Template, 2104 SourceLocation TemplateLoc, 2105 SourceLocation RAngleLoc, 2106 NonTypeTemplateParmDecl *Param, 2107 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 2108 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2109 Converted.data(), Converted.size()); 2110 2111 MultiLevelTemplateArgumentList AllTemplateArgs 2112 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 2113 2114 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 2115 Template, Converted.data(), 2116 Converted.size(), 2117 SourceRange(TemplateLoc, RAngleLoc)); 2118 2119 return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs); 2120} 2121 2122/// \brief Substitute template arguments into the default template argument for 2123/// the given template template parameter. 2124/// 2125/// \param SemaRef the semantic analysis object for which we are performing 2126/// the substitution. 2127/// 2128/// \param Template the template that we are synthesizing template arguments 2129/// for. 2130/// 2131/// \param TemplateLoc the location of the template name that started the 2132/// template-id we are checking. 2133/// 2134/// \param RAngleLoc the location of the right angle bracket ('>') that 2135/// terminates the template-id. 2136/// 2137/// \param Param the template template parameter whose default we are 2138/// substituting into. 2139/// 2140/// \param Converted the list of template arguments provided for template 2141/// parameters that precede \p Param in the template parameter list. 2142/// 2143/// \returns the substituted template argument, or NULL if an error occurred. 2144static TemplateName 2145SubstDefaultTemplateArgument(Sema &SemaRef, 2146 TemplateDecl *Template, 2147 SourceLocation TemplateLoc, 2148 SourceLocation RAngleLoc, 2149 TemplateTemplateParmDecl *Param, 2150 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 2151 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2152 Converted.data(), Converted.size()); 2153 2154 MultiLevelTemplateArgumentList AllTemplateArgs 2155 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 2156 2157 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 2158 Template, Converted.data(), 2159 Converted.size(), 2160 SourceRange(TemplateLoc, RAngleLoc)); 2161 2162 return SemaRef.SubstTemplateName( 2163 Param->getDefaultArgument().getArgument().getAsTemplate(), 2164 Param->getDefaultArgument().getTemplateNameLoc(), 2165 AllTemplateArgs); 2166} 2167 2168/// \brief If the given template parameter has a default template 2169/// argument, substitute into that default template argument and 2170/// return the corresponding template argument. 2171TemplateArgumentLoc 2172Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template, 2173 SourceLocation TemplateLoc, 2174 SourceLocation RAngleLoc, 2175 Decl *Param, 2176 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 2177 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) { 2178 if (!TypeParm->hasDefaultArgument()) 2179 return TemplateArgumentLoc(); 2180 2181 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template, 2182 TemplateLoc, 2183 RAngleLoc, 2184 TypeParm, 2185 Converted); 2186 if (DI) 2187 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI); 2188 2189 return TemplateArgumentLoc(); 2190 } 2191 2192 if (NonTypeTemplateParmDecl *NonTypeParm 2193 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2194 if (!NonTypeParm->hasDefaultArgument()) 2195 return TemplateArgumentLoc(); 2196 2197 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template, 2198 TemplateLoc, 2199 RAngleLoc, 2200 NonTypeParm, 2201 Converted); 2202 if (Arg.isInvalid()) 2203 return TemplateArgumentLoc(); 2204 2205 Expr *ArgE = Arg.takeAs<Expr>(); 2206 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE); 2207 } 2208 2209 TemplateTemplateParmDecl *TempTempParm 2210 = cast<TemplateTemplateParmDecl>(Param); 2211 if (!TempTempParm->hasDefaultArgument()) 2212 return TemplateArgumentLoc(); 2213 2214 TemplateName TName = SubstDefaultTemplateArgument(*this, Template, 2215 TemplateLoc, 2216 RAngleLoc, 2217 TempTempParm, 2218 Converted); 2219 if (TName.isNull()) 2220 return TemplateArgumentLoc(); 2221 2222 return TemplateArgumentLoc(TemplateArgument(TName), 2223 TempTempParm->getDefaultArgument().getTemplateQualifierRange(), 2224 TempTempParm->getDefaultArgument().getTemplateNameLoc()); 2225} 2226 2227/// \brief Check that the given template argument corresponds to the given 2228/// template parameter. 2229/// 2230/// \param Param The template parameter against which the argument will be 2231/// checked. 2232/// 2233/// \param Arg The template argument. 2234/// 2235/// \param Template The template in which the template argument resides. 2236/// 2237/// \param TemplateLoc The location of the template name for the template 2238/// whose argument list we're matching. 2239/// 2240/// \param RAngleLoc The location of the right angle bracket ('>') that closes 2241/// the template argument list. 2242/// 2243/// \param ArgumentPackIndex The index into the argument pack where this 2244/// argument will be placed. Only valid if the parameter is a parameter pack. 2245/// 2246/// \param Converted The checked, converted argument will be added to the 2247/// end of this small vector. 2248/// 2249/// \param CTAK Describes how we arrived at this particular template argument: 2250/// explicitly written, deduced, etc. 2251/// 2252/// \returns true on error, false otherwise. 2253bool Sema::CheckTemplateArgument(NamedDecl *Param, 2254 const TemplateArgumentLoc &Arg, 2255 NamedDecl *Template, 2256 SourceLocation TemplateLoc, 2257 SourceLocation RAngleLoc, 2258 unsigned ArgumentPackIndex, 2259 llvm::SmallVectorImpl<TemplateArgument> &Converted, 2260 CheckTemplateArgumentKind CTAK) { 2261 // Check template type parameters. 2262 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) 2263 return CheckTemplateTypeArgument(TTP, Arg, Converted); 2264 2265 // Check non-type template parameters. 2266 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2267 // Do substitution on the type of the non-type template parameter 2268 // with the template arguments we've seen thus far. But if the 2269 // template has a dependent context then we cannot substitute yet. 2270 QualType NTTPType = NTTP->getType(); 2271 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack()) 2272 NTTPType = NTTP->getExpansionType(ArgumentPackIndex); 2273 2274 if (NTTPType->isDependentType() && 2275 !isa<TemplateTemplateParmDecl>(Template) && 2276 !Template->getDeclContext()->isDependentContext()) { 2277 // Do substitution on the type of the non-type template parameter. 2278 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2279 NTTP, Converted.data(), Converted.size(), 2280 SourceRange(TemplateLoc, RAngleLoc)); 2281 2282 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2283 Converted.data(), Converted.size()); 2284 NTTPType = SubstType(NTTPType, 2285 MultiLevelTemplateArgumentList(TemplateArgs), 2286 NTTP->getLocation(), 2287 NTTP->getDeclName()); 2288 // If that worked, check the non-type template parameter type 2289 // for validity. 2290 if (!NTTPType.isNull()) 2291 NTTPType = CheckNonTypeTemplateParameterType(NTTPType, 2292 NTTP->getLocation()); 2293 if (NTTPType.isNull()) 2294 return true; 2295 } 2296 2297 switch (Arg.getArgument().getKind()) { 2298 case TemplateArgument::Null: 2299 assert(false && "Should never see a NULL template argument here"); 2300 return true; 2301 2302 case TemplateArgument::Expression: { 2303 Expr *E = Arg.getArgument().getAsExpr(); 2304 TemplateArgument Result; 2305 if (CheckTemplateArgument(NTTP, NTTPType, E, Result, CTAK)) 2306 return true; 2307 2308 Converted.push_back(Result); 2309 break; 2310 } 2311 2312 case TemplateArgument::Declaration: 2313 case TemplateArgument::Integral: 2314 // We've already checked this template argument, so just copy 2315 // it to the list of converted arguments. 2316 Converted.push_back(Arg.getArgument()); 2317 break; 2318 2319 case TemplateArgument::Template: 2320 case TemplateArgument::TemplateExpansion: 2321 // We were given a template template argument. It may not be ill-formed; 2322 // see below. 2323 if (DependentTemplateName *DTN 2324 = Arg.getArgument().getAsTemplateOrTemplatePattern() 2325 .getAsDependentTemplateName()) { 2326 // We have a template argument such as \c T::template X, which we 2327 // parsed as a template template argument. However, since we now 2328 // know that we need a non-type template argument, convert this 2329 // template name into an expression. 2330 2331 DeclarationNameInfo NameInfo(DTN->getIdentifier(), 2332 Arg.getTemplateNameLoc()); 2333 2334 // FIXME: TemplateArgumentLoc should store a NestedNameSpecifierLoc 2335 // for the template name. 2336 CXXScopeSpec SS; 2337 SS.MakeTrivial(Context, DTN->getQualifier(), 2338 Arg.getTemplateQualifierRange()); 2339 Expr *E = DependentScopeDeclRefExpr::Create(Context, 2340 SS.getWithLocInContext(Context), 2341 NameInfo); 2342 2343 // If we parsed the template argument as a pack expansion, create a 2344 // pack expansion expression. 2345 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){ 2346 ExprResult Expansion = ActOnPackExpansion(E, 2347 Arg.getTemplateEllipsisLoc()); 2348 if (Expansion.isInvalid()) 2349 return true; 2350 2351 E = Expansion.get(); 2352 } 2353 2354 TemplateArgument Result; 2355 if (CheckTemplateArgument(NTTP, NTTPType, E, Result)) 2356 return true; 2357 2358 Converted.push_back(Result); 2359 break; 2360 } 2361 2362 // We have a template argument that actually does refer to a class 2363 // template, template alias, or template template parameter, and 2364 // therefore cannot be a non-type template argument. 2365 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) 2366 << Arg.getSourceRange(); 2367 2368 Diag(Param->getLocation(), diag::note_template_param_here); 2369 return true; 2370 2371 case TemplateArgument::Type: { 2372 // We have a non-type template parameter but the template 2373 // argument is a type. 2374 2375 // C++ [temp.arg]p2: 2376 // In a template-argument, an ambiguity between a type-id and 2377 // an expression is resolved to a type-id, regardless of the 2378 // form of the corresponding template-parameter. 2379 // 2380 // We warn specifically about this case, since it can be rather 2381 // confusing for users. 2382 QualType T = Arg.getArgument().getAsType(); 2383 SourceRange SR = Arg.getSourceRange(); 2384 if (T->isFunctionType()) 2385 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; 2386 else 2387 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; 2388 Diag(Param->getLocation(), diag::note_template_param_here); 2389 return true; 2390 } 2391 2392 case TemplateArgument::Pack: 2393 llvm_unreachable("Caller must expand template argument packs"); 2394 break; 2395 } 2396 2397 return false; 2398 } 2399 2400 2401 // Check template template parameters. 2402 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param); 2403 2404 // Substitute into the template parameter list of the template 2405 // template parameter, since previously-supplied template arguments 2406 // may appear within the template template parameter. 2407 { 2408 // Set up a template instantiation context. 2409 LocalInstantiationScope Scope(*this); 2410 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2411 TempParm, Converted.data(), Converted.size(), 2412 SourceRange(TemplateLoc, RAngleLoc)); 2413 2414 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, 2415 Converted.data(), Converted.size()); 2416 TempParm = cast_or_null<TemplateTemplateParmDecl>( 2417 SubstDecl(TempParm, CurContext, 2418 MultiLevelTemplateArgumentList(TemplateArgs))); 2419 if (!TempParm) 2420 return true; 2421 } 2422 2423 switch (Arg.getArgument().getKind()) { 2424 case TemplateArgument::Null: 2425 assert(false && "Should never see a NULL template argument here"); 2426 return true; 2427 2428 case TemplateArgument::Template: 2429 case TemplateArgument::TemplateExpansion: 2430 if (CheckTemplateArgument(TempParm, Arg)) 2431 return true; 2432 2433 Converted.push_back(Arg.getArgument()); 2434 break; 2435 2436 case TemplateArgument::Expression: 2437 case TemplateArgument::Type: 2438 // We have a template template parameter but the template 2439 // argument does not refer to a template. 2440 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template); 2441 return true; 2442 2443 case TemplateArgument::Declaration: 2444 llvm_unreachable( 2445 "Declaration argument with template template parameter"); 2446 break; 2447 case TemplateArgument::Integral: 2448 llvm_unreachable( 2449 "Integral argument with template template parameter"); 2450 break; 2451 2452 case TemplateArgument::Pack: 2453 llvm_unreachable("Caller must expand template argument packs"); 2454 break; 2455 } 2456 2457 return false; 2458} 2459 2460/// \brief Check that the given template argument list is well-formed 2461/// for specializing the given template. 2462bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, 2463 SourceLocation TemplateLoc, 2464 const TemplateArgumentListInfo &TemplateArgs, 2465 bool PartialTemplateArgs, 2466 llvm::SmallVectorImpl<TemplateArgument> &Converted) { 2467 TemplateParameterList *Params = Template->getTemplateParameters(); 2468 unsigned NumParams = Params->size(); 2469 unsigned NumArgs = TemplateArgs.size(); 2470 bool Invalid = false; 2471 2472 SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc(); 2473 2474 bool HasParameterPack = 2475 NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack(); 2476 2477 if ((NumArgs > NumParams && !HasParameterPack) || 2478 (NumArgs < Params->getMinRequiredArguments() && 2479 !PartialTemplateArgs)) { 2480 // FIXME: point at either the first arg beyond what we can handle, 2481 // or the '>', depending on whether we have too many or too few 2482 // arguments. 2483 SourceRange Range; 2484 if (NumArgs > NumParams) 2485 Range = SourceRange(TemplateArgs[NumParams].getLocation(), RAngleLoc); 2486 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 2487 << (NumArgs > NumParams) 2488 << (isa<ClassTemplateDecl>(Template)? 0 : 2489 isa<FunctionTemplateDecl>(Template)? 1 : 2490 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 2491 << Template << Range; 2492 Diag(Template->getLocation(), diag::note_template_decl_here) 2493 << Params->getSourceRange(); 2494 Invalid = true; 2495 } 2496 2497 // C++ [temp.arg]p1: 2498 // [...] The type and form of each template-argument specified in 2499 // a template-id shall match the type and form specified for the 2500 // corresponding parameter declared by the template in its 2501 // template-parameter-list. 2502 llvm::SmallVector<TemplateArgument, 2> ArgumentPack; 2503 TemplateParameterList::iterator Param = Params->begin(), 2504 ParamEnd = Params->end(); 2505 unsigned ArgIdx = 0; 2506 LocalInstantiationScope InstScope(*this, true); 2507 while (Param != ParamEnd) { 2508 if (ArgIdx > NumArgs && PartialTemplateArgs) 2509 break; 2510 2511 if (ArgIdx < NumArgs) { 2512 // If we have an expanded parameter pack, make sure we don't have too 2513 // many arguments. 2514 if (NonTypeTemplateParmDecl *NTTP 2515 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 2516 if (NTTP->isExpandedParameterPack() && 2517 ArgumentPack.size() >= NTTP->getNumExpansionTypes()) { 2518 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 2519 << true 2520 << (isa<ClassTemplateDecl>(Template)? 0 : 2521 isa<FunctionTemplateDecl>(Template)? 1 : 2522 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 2523 << Template; 2524 Diag(Template->getLocation(), diag::note_template_decl_here) 2525 << Params->getSourceRange(); 2526 return true; 2527 } 2528 } 2529 2530 // Check the template argument we were given. 2531 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 2532 TemplateLoc, RAngleLoc, 2533 ArgumentPack.size(), Converted)) 2534 return true; 2535 2536 if ((*Param)->isTemplateParameterPack()) { 2537 // The template parameter was a template parameter pack, so take the 2538 // deduced argument and place it on the argument pack. Note that we 2539 // stay on the same template parameter so that we can deduce more 2540 // arguments. 2541 ArgumentPack.push_back(Converted.back()); 2542 Converted.pop_back(); 2543 } else { 2544 // Move to the next template parameter. 2545 ++Param; 2546 } 2547 ++ArgIdx; 2548 continue; 2549 } 2550 2551 // If we have a template parameter pack with no more corresponding 2552 // arguments, just break out now and we'll fill in the argument pack below. 2553 if ((*Param)->isTemplateParameterPack()) 2554 break; 2555 2556 // We have a default template argument that we will use. 2557 TemplateArgumentLoc Arg; 2558 2559 // Retrieve the default template argument from the template 2560 // parameter. For each kind of template parameter, we substitute the 2561 // template arguments provided thus far and any "outer" template arguments 2562 // (when the template parameter was part of a nested template) into 2563 // the default argument. 2564 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) { 2565 if (!TTP->hasDefaultArgument()) { 2566 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2567 break; 2568 } 2569 2570 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this, 2571 Template, 2572 TemplateLoc, 2573 RAngleLoc, 2574 TTP, 2575 Converted); 2576 if (!ArgType) 2577 return true; 2578 2579 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), 2580 ArgType); 2581 } else if (NonTypeTemplateParmDecl *NTTP 2582 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 2583 if (!NTTP->hasDefaultArgument()) { 2584 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2585 break; 2586 } 2587 2588 ExprResult E = SubstDefaultTemplateArgument(*this, Template, 2589 TemplateLoc, 2590 RAngleLoc, 2591 NTTP, 2592 Converted); 2593 if (E.isInvalid()) 2594 return true; 2595 2596 Expr *Ex = E.takeAs<Expr>(); 2597 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); 2598 } else { 2599 TemplateTemplateParmDecl *TempParm 2600 = cast<TemplateTemplateParmDecl>(*Param); 2601 2602 if (!TempParm->hasDefaultArgument()) { 2603 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2604 break; 2605 } 2606 2607 TemplateName Name = SubstDefaultTemplateArgument(*this, Template, 2608 TemplateLoc, 2609 RAngleLoc, 2610 TempParm, 2611 Converted); 2612 if (Name.isNull()) 2613 return true; 2614 2615 Arg = TemplateArgumentLoc(TemplateArgument(Name), 2616 TempParm->getDefaultArgument().getTemplateQualifierRange(), 2617 TempParm->getDefaultArgument().getTemplateNameLoc()); 2618 } 2619 2620 // Introduce an instantiation record that describes where we are using 2621 // the default template argument. 2622 InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param, 2623 Converted.data(), Converted.size(), 2624 SourceRange(TemplateLoc, RAngleLoc)); 2625 2626 // Check the default template argument. 2627 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, 2628 RAngleLoc, 0, Converted)) 2629 return true; 2630 2631 // Move to the next template parameter and argument. 2632 ++Param; 2633 ++ArgIdx; 2634 } 2635 2636 // Form argument packs for each of the parameter packs remaining. 2637 while (Param != ParamEnd) { 2638 // If we're checking a partial list of template arguments, don't fill 2639 // in arguments for non-template parameter packs. 2640 2641 if ((*Param)->isTemplateParameterPack()) { 2642 if (PartialTemplateArgs && ArgumentPack.empty()) { 2643 Converted.push_back(TemplateArgument()); 2644 } else if (ArgumentPack.empty()) 2645 Converted.push_back(TemplateArgument(0, 0)); 2646 else { 2647 Converted.push_back(TemplateArgument::CreatePackCopy(Context, 2648 ArgumentPack.data(), 2649 ArgumentPack.size())); 2650 ArgumentPack.clear(); 2651 } 2652 } 2653 2654 ++Param; 2655 } 2656 2657 return Invalid; 2658} 2659 2660namespace { 2661 class UnnamedLocalNoLinkageFinder 2662 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool> 2663 { 2664 Sema &S; 2665 SourceRange SR; 2666 2667 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited; 2668 2669 public: 2670 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { } 2671 2672 bool Visit(QualType T) { 2673 return inherited::Visit(T.getTypePtr()); 2674 } 2675 2676#define TYPE(Class, Parent) \ 2677 bool Visit##Class##Type(const Class##Type *); 2678#define ABSTRACT_TYPE(Class, Parent) \ 2679 bool Visit##Class##Type(const Class##Type *) { return false; } 2680#define NON_CANONICAL_TYPE(Class, Parent) \ 2681 bool Visit##Class##Type(const Class##Type *) { return false; } 2682#include "clang/AST/TypeNodes.def" 2683 2684 bool VisitTagDecl(const TagDecl *Tag); 2685 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS); 2686 }; 2687} 2688 2689bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) { 2690 return false; 2691} 2692 2693bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) { 2694 return Visit(T->getElementType()); 2695} 2696 2697bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) { 2698 return Visit(T->getPointeeType()); 2699} 2700 2701bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType( 2702 const BlockPointerType* T) { 2703 return Visit(T->getPointeeType()); 2704} 2705 2706bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType( 2707 const LValueReferenceType* T) { 2708 return Visit(T->getPointeeType()); 2709} 2710 2711bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType( 2712 const RValueReferenceType* T) { 2713 return Visit(T->getPointeeType()); 2714} 2715 2716bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType( 2717 const MemberPointerType* T) { 2718 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0)); 2719} 2720 2721bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType( 2722 const ConstantArrayType* T) { 2723 return Visit(T->getElementType()); 2724} 2725 2726bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType( 2727 const IncompleteArrayType* T) { 2728 return Visit(T->getElementType()); 2729} 2730 2731bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType( 2732 const VariableArrayType* T) { 2733 return Visit(T->getElementType()); 2734} 2735 2736bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType( 2737 const DependentSizedArrayType* T) { 2738 return Visit(T->getElementType()); 2739} 2740 2741bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType( 2742 const DependentSizedExtVectorType* T) { 2743 return Visit(T->getElementType()); 2744} 2745 2746bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) { 2747 return Visit(T->getElementType()); 2748} 2749 2750bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) { 2751 return Visit(T->getElementType()); 2752} 2753 2754bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType( 2755 const FunctionProtoType* T) { 2756 for (FunctionProtoType::arg_type_iterator A = T->arg_type_begin(), 2757 AEnd = T->arg_type_end(); 2758 A != AEnd; ++A) { 2759 if (Visit(*A)) 2760 return true; 2761 } 2762 2763 return Visit(T->getResultType()); 2764} 2765 2766bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType( 2767 const FunctionNoProtoType* T) { 2768 return Visit(T->getResultType()); 2769} 2770 2771bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType( 2772 const UnresolvedUsingType*) { 2773 return false; 2774} 2775 2776bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) { 2777 return false; 2778} 2779 2780bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) { 2781 return Visit(T->getUnderlyingType()); 2782} 2783 2784bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) { 2785 return false; 2786} 2787 2788bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) { 2789 return Visit(T->getDeducedType()); 2790} 2791 2792bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) { 2793 return VisitTagDecl(T->getDecl()); 2794} 2795 2796bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) { 2797 return VisitTagDecl(T->getDecl()); 2798} 2799 2800bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType( 2801 const TemplateTypeParmType*) { 2802 return false; 2803} 2804 2805bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType( 2806 const SubstTemplateTypeParmPackType *) { 2807 return false; 2808} 2809 2810bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType( 2811 const TemplateSpecializationType*) { 2812 return false; 2813} 2814 2815bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType( 2816 const InjectedClassNameType* T) { 2817 return VisitTagDecl(T->getDecl()); 2818} 2819 2820bool UnnamedLocalNoLinkageFinder::VisitDependentNameType( 2821 const DependentNameType* T) { 2822 return VisitNestedNameSpecifier(T->getQualifier()); 2823} 2824 2825bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType( 2826 const DependentTemplateSpecializationType* T) { 2827 return VisitNestedNameSpecifier(T->getQualifier()); 2828} 2829 2830bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType( 2831 const PackExpansionType* T) { 2832 return Visit(T->getPattern()); 2833} 2834 2835bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) { 2836 return false; 2837} 2838 2839bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType( 2840 const ObjCInterfaceType *) { 2841 return false; 2842} 2843 2844bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType( 2845 const ObjCObjectPointerType *) { 2846 return false; 2847} 2848 2849bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) { 2850 if (Tag->getDeclContext()->isFunctionOrMethod()) { 2851 S.Diag(SR.getBegin(), diag::ext_template_arg_local_type) 2852 << S.Context.getTypeDeclType(Tag) << SR; 2853 return true; 2854 } 2855 2856 if (!Tag->getDeclName() && !Tag->getTypedefForAnonDecl()) { 2857 S.Diag(SR.getBegin(), diag::ext_template_arg_unnamed_type) << SR; 2858 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here); 2859 return true; 2860 } 2861 2862 return false; 2863} 2864 2865bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier( 2866 NestedNameSpecifier *NNS) { 2867 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix())) 2868 return true; 2869 2870 switch (NNS->getKind()) { 2871 case NestedNameSpecifier::Identifier: 2872 case NestedNameSpecifier::Namespace: 2873 case NestedNameSpecifier::NamespaceAlias: 2874 case NestedNameSpecifier::Global: 2875 return false; 2876 2877 case NestedNameSpecifier::TypeSpec: 2878 case NestedNameSpecifier::TypeSpecWithTemplate: 2879 return Visit(QualType(NNS->getAsType(), 0)); 2880 } 2881 return false; 2882} 2883 2884 2885/// \brief Check a template argument against its corresponding 2886/// template type parameter. 2887/// 2888/// This routine implements the semantics of C++ [temp.arg.type]. It 2889/// returns true if an error occurred, and false otherwise. 2890bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, 2891 TypeSourceInfo *ArgInfo) { 2892 assert(ArgInfo && "invalid TypeSourceInfo"); 2893 QualType Arg = ArgInfo->getType(); 2894 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 2895 2896 if (Arg->isVariablyModifiedType()) { 2897 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg; 2898 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) { 2899 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR; 2900 } 2901 2902 // C++03 [temp.arg.type]p2: 2903 // A local type, a type with no linkage, an unnamed type or a type 2904 // compounded from any of these types shall not be used as a 2905 // template-argument for a template type-parameter. 2906 // 2907 // C++0x allows these, and even in C++03 we allow them as an extension with 2908 // a warning. 2909 if (!LangOpts.CPlusPlus0x && Arg->hasUnnamedOrLocalType()) { 2910 UnnamedLocalNoLinkageFinder Finder(*this, SR); 2911 (void)Finder.Visit(Context.getCanonicalType(Arg)); 2912 } 2913 2914 return false; 2915} 2916 2917/// \brief Checks whether the given template argument is the address 2918/// of an object or function according to C++ [temp.arg.nontype]p1. 2919static bool 2920CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S, 2921 NonTypeTemplateParmDecl *Param, 2922 QualType ParamType, 2923 Expr *ArgIn, 2924 TemplateArgument &Converted) { 2925 bool Invalid = false; 2926 Expr *Arg = ArgIn; 2927 QualType ArgType = Arg->getType(); 2928 2929 // See through any implicit casts we added to fix the type. 2930 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2931 Arg = Cast->getSubExpr(); 2932 2933 // C++ [temp.arg.nontype]p1: 2934 // 2935 // A template-argument for a non-type, non-template 2936 // template-parameter shall be one of: [...] 2937 // 2938 // -- the address of an object or function with external 2939 // linkage, including function templates and function 2940 // template-ids but excluding non-static class members, 2941 // expressed as & id-expression where the & is optional if 2942 // the name refers to a function or array, or if the 2943 // corresponding template-parameter is a reference; or 2944 DeclRefExpr *DRE = 0; 2945 2946 // In C++98/03 mode, give an extension warning on any extra parentheses. 2947 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 2948 bool ExtraParens = false; 2949 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2950 if (!Invalid && !ExtraParens && !S.getLangOptions().CPlusPlus0x) { 2951 S.Diag(Arg->getSourceRange().getBegin(), 2952 diag::ext_template_arg_extra_parens) 2953 << Arg->getSourceRange(); 2954 ExtraParens = true; 2955 } 2956 2957 Arg = Parens->getSubExpr(); 2958 } 2959 2960 bool AddressTaken = false; 2961 SourceLocation AddrOpLoc; 2962 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2963 if (UnOp->getOpcode() == UO_AddrOf) { 2964 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2965 AddressTaken = true; 2966 AddrOpLoc = UnOp->getOperatorLoc(); 2967 } 2968 } else 2969 DRE = dyn_cast<DeclRefExpr>(Arg); 2970 2971 if (!DRE) { 2972 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 2973 << Arg->getSourceRange(); 2974 S.Diag(Param->getLocation(), diag::note_template_param_here); 2975 return true; 2976 } 2977 2978 // Stop checking the precise nature of the argument if it is value dependent, 2979 // it should be checked when instantiated. 2980 if (Arg->isValueDependent()) { 2981 Converted = TemplateArgument(ArgIn); 2982 return false; 2983 } 2984 2985 if (!isa<ValueDecl>(DRE->getDecl())) { 2986 S.Diag(Arg->getSourceRange().getBegin(), 2987 diag::err_template_arg_not_object_or_func_form) 2988 << Arg->getSourceRange(); 2989 S.Diag(Param->getLocation(), diag::note_template_param_here); 2990 return true; 2991 } 2992 2993 NamedDecl *Entity = 0; 2994 2995 // Cannot refer to non-static data members 2996 if (FieldDecl *Field = dyn_cast<FieldDecl>(DRE->getDecl())) { 2997 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_field) 2998 << Field << Arg->getSourceRange(); 2999 S.Diag(Param->getLocation(), diag::note_template_param_here); 3000 return true; 3001 } 3002 3003 // Cannot refer to non-static member functions 3004 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(DRE->getDecl())) 3005 if (!Method->isStatic()) { 3006 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_method) 3007 << Method << Arg->getSourceRange(); 3008 S.Diag(Param->getLocation(), diag::note_template_param_here); 3009 return true; 3010 } 3011 3012 // Functions must have external linkage. 3013 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(DRE->getDecl())) { 3014 if (!isExternalLinkage(Func->getLinkage())) { 3015 S.Diag(Arg->getSourceRange().getBegin(), 3016 diag::err_template_arg_function_not_extern) 3017 << Func << Arg->getSourceRange(); 3018 S.Diag(Func->getLocation(), diag::note_template_arg_internal_object) 3019 << true; 3020 return true; 3021 } 3022 3023 // Okay: we've named a function with external linkage. 3024 Entity = Func; 3025 3026 // If the template parameter has pointer type, the function decays. 3027 if (ParamType->isPointerType() && !AddressTaken) 3028 ArgType = S.Context.getPointerType(Func->getType()); 3029 else if (AddressTaken && ParamType->isReferenceType()) { 3030 // If we originally had an address-of operator, but the 3031 // parameter has reference type, complain and (if things look 3032 // like they will work) drop the address-of operator. 3033 if (!S.Context.hasSameUnqualifiedType(Func->getType(), 3034 ParamType.getNonReferenceType())) { 3035 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 3036 << ParamType; 3037 S.Diag(Param->getLocation(), diag::note_template_param_here); 3038 return true; 3039 } 3040 3041 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 3042 << ParamType 3043 << FixItHint::CreateRemoval(AddrOpLoc); 3044 S.Diag(Param->getLocation(), diag::note_template_param_here); 3045 3046 ArgType = Func->getType(); 3047 } 3048 } else if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 3049 if (!isExternalLinkage(Var->getLinkage())) { 3050 S.Diag(Arg->getSourceRange().getBegin(), 3051 diag::err_template_arg_object_not_extern) 3052 << Var << Arg->getSourceRange(); 3053 S.Diag(Var->getLocation(), diag::note_template_arg_internal_object) 3054 << true; 3055 return true; 3056 } 3057 3058 // A value of reference type is not an object. 3059 if (Var->getType()->isReferenceType()) { 3060 S.Diag(Arg->getSourceRange().getBegin(), 3061 diag::err_template_arg_reference_var) 3062 << Var->getType() << Arg->getSourceRange(); 3063 S.Diag(Param->getLocation(), diag::note_template_param_here); 3064 return true; 3065 } 3066 3067 // Okay: we've named an object with external linkage 3068 Entity = Var; 3069 3070 // If the template parameter has pointer type, we must have taken 3071 // the address of this object. 3072 if (ParamType->isReferenceType()) { 3073 if (AddressTaken) { 3074 // If we originally had an address-of operator, but the 3075 // parameter has reference type, complain and (if things look 3076 // like they will work) drop the address-of operator. 3077 if (!S.Context.hasSameUnqualifiedType(Var->getType(), 3078 ParamType.getNonReferenceType())) { 3079 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 3080 << ParamType; 3081 S.Diag(Param->getLocation(), diag::note_template_param_here); 3082 return true; 3083 } 3084 3085 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 3086 << ParamType 3087 << FixItHint::CreateRemoval(AddrOpLoc); 3088 S.Diag(Param->getLocation(), diag::note_template_param_here); 3089 3090 ArgType = Var->getType(); 3091 } 3092 } else if (!AddressTaken && ParamType->isPointerType()) { 3093 if (Var->getType()->isArrayType()) { 3094 // Array-to-pointer decay. 3095 ArgType = S.Context.getArrayDecayedType(Var->getType()); 3096 } else { 3097 // If the template parameter has pointer type but the address of 3098 // this object was not taken, complain and (possibly) recover by 3099 // taking the address of the entity. 3100 ArgType = S.Context.getPointerType(Var->getType()); 3101 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) { 3102 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 3103 << ParamType; 3104 S.Diag(Param->getLocation(), diag::note_template_param_here); 3105 return true; 3106 } 3107 3108 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 3109 << ParamType 3110 << FixItHint::CreateInsertion(Arg->getLocStart(), "&"); 3111 3112 S.Diag(Param->getLocation(), diag::note_template_param_here); 3113 } 3114 } 3115 } else { 3116 // We found something else, but we don't know specifically what it is. 3117 S.Diag(Arg->getSourceRange().getBegin(), 3118 diag::err_template_arg_not_object_or_func) 3119 << Arg->getSourceRange(); 3120 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); 3121 return true; 3122 } 3123 3124 if (ParamType->isPointerType() && 3125 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() && 3126 S.IsQualificationConversion(ArgType, ParamType, false)) { 3127 // For pointer-to-object types, qualification conversions are 3128 // permitted. 3129 } else { 3130 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) { 3131 if (!ParamRef->getPointeeType()->isFunctionType()) { 3132 // C++ [temp.arg.nontype]p5b3: 3133 // For a non-type template-parameter of type reference to 3134 // object, no conversions apply. The type referred to by the 3135 // reference may be more cv-qualified than the (otherwise 3136 // identical) type of the template- argument. The 3137 // template-parameter is bound directly to the 3138 // template-argument, which shall be an lvalue. 3139 3140 // FIXME: Other qualifiers? 3141 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers(); 3142 unsigned ArgQuals = ArgType.getCVRQualifiers(); 3143 3144 if ((ParamQuals | ArgQuals) != ParamQuals) { 3145 S.Diag(Arg->getSourceRange().getBegin(), 3146 diag::err_template_arg_ref_bind_ignores_quals) 3147 << ParamType << Arg->getType() 3148 << Arg->getSourceRange(); 3149 S.Diag(Param->getLocation(), diag::note_template_param_here); 3150 return true; 3151 } 3152 } 3153 } 3154 3155 // At this point, the template argument refers to an object or 3156 // function with external linkage. We now need to check whether the 3157 // argument and parameter types are compatible. 3158 if (!S.Context.hasSameUnqualifiedType(ArgType, 3159 ParamType.getNonReferenceType())) { 3160 // We can't perform this conversion or binding. 3161 if (ParamType->isReferenceType()) 3162 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind) 3163 << ParamType << Arg->getType() << Arg->getSourceRange(); 3164 else 3165 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) 3166 << Arg->getType() << ParamType << Arg->getSourceRange(); 3167 S.Diag(Param->getLocation(), diag::note_template_param_here); 3168 return true; 3169 } 3170 } 3171 3172 // Create the template argument. 3173 Converted = TemplateArgument(Entity->getCanonicalDecl()); 3174 S.MarkDeclarationReferenced(Arg->getLocStart(), Entity); 3175 return false; 3176} 3177 3178/// \brief Checks whether the given template argument is a pointer to 3179/// member constant according to C++ [temp.arg.nontype]p1. 3180bool Sema::CheckTemplateArgumentPointerToMember(Expr *Arg, 3181 TemplateArgument &Converted) { 3182 bool Invalid = false; 3183 3184 // See through any implicit casts we added to fix the type. 3185 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 3186 Arg = Cast->getSubExpr(); 3187 3188 // C++ [temp.arg.nontype]p1: 3189 // 3190 // A template-argument for a non-type, non-template 3191 // template-parameter shall be one of: [...] 3192 // 3193 // -- a pointer to member expressed as described in 5.3.1. 3194 DeclRefExpr *DRE = 0; 3195 3196 // In C++98/03 mode, give an extension warning on any extra parentheses. 3197 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 3198 bool ExtraParens = false; 3199 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 3200 if (!Invalid && !ExtraParens && !getLangOptions().CPlusPlus0x) { 3201 Diag(Arg->getSourceRange().getBegin(), 3202 diag::ext_template_arg_extra_parens) 3203 << Arg->getSourceRange(); 3204 ExtraParens = true; 3205 } 3206 3207 Arg = Parens->getSubExpr(); 3208 } 3209 3210 // A pointer-to-member constant written &Class::member. 3211 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 3212 if (UnOp->getOpcode() == UO_AddrOf) { 3213 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 3214 if (DRE && !DRE->getQualifier()) 3215 DRE = 0; 3216 } 3217 } 3218 // A constant of pointer-to-member type. 3219 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) { 3220 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) { 3221 if (VD->getType()->isMemberPointerType()) { 3222 if (isa<NonTypeTemplateParmDecl>(VD) || 3223 (isa<VarDecl>(VD) && 3224 Context.getCanonicalType(VD->getType()).isConstQualified())) { 3225 if (Arg->isTypeDependent() || Arg->isValueDependent()) 3226 Converted = TemplateArgument(Arg); 3227 else 3228 Converted = TemplateArgument(VD->getCanonicalDecl()); 3229 return Invalid; 3230 } 3231 } 3232 } 3233 3234 DRE = 0; 3235 } 3236 3237 if (!DRE) 3238 return Diag(Arg->getSourceRange().getBegin(), 3239 diag::err_template_arg_not_pointer_to_member_form) 3240 << Arg->getSourceRange(); 3241 3242 if (isa<FieldDecl>(DRE->getDecl()) || isa<CXXMethodDecl>(DRE->getDecl())) { 3243 assert((isa<FieldDecl>(DRE->getDecl()) || 3244 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && 3245 "Only non-static member pointers can make it here"); 3246 3247 // Okay: this is the address of a non-static member, and therefore 3248 // a member pointer constant. 3249 if (Arg->isTypeDependent() || Arg->isValueDependent()) 3250 Converted = TemplateArgument(Arg); 3251 else 3252 Converted = TemplateArgument(DRE->getDecl()->getCanonicalDecl()); 3253 return Invalid; 3254 } 3255 3256 // We found something else, but we don't know specifically what it is. 3257 Diag(Arg->getSourceRange().getBegin(), 3258 diag::err_template_arg_not_pointer_to_member_form) 3259 << Arg->getSourceRange(); 3260 Diag(DRE->getDecl()->getLocation(), 3261 diag::note_template_arg_refers_here); 3262 return true; 3263} 3264 3265/// \brief Check a template argument against its corresponding 3266/// non-type template parameter. 3267/// 3268/// This routine implements the semantics of C++ [temp.arg.nontype]. 3269/// It returns true if an error occurred, and false otherwise. \p 3270/// InstantiatedParamType is the type of the non-type template 3271/// parameter after it has been instantiated. 3272/// 3273/// If no error was detected, Converted receives the converted template argument. 3274bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, 3275 QualType InstantiatedParamType, Expr *&Arg, 3276 TemplateArgument &Converted, 3277 CheckTemplateArgumentKind CTAK) { 3278 SourceLocation StartLoc = Arg->getSourceRange().getBegin(); 3279 3280 // If either the parameter has a dependent type or the argument is 3281 // type-dependent, there's nothing we can check now. 3282 if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) { 3283 // FIXME: Produce a cloned, canonical expression? 3284 Converted = TemplateArgument(Arg); 3285 return false; 3286 } 3287 3288 // C++ [temp.arg.nontype]p5: 3289 // The following conversions are performed on each expression used 3290 // as a non-type template-argument. If a non-type 3291 // template-argument cannot be converted to the type of the 3292 // corresponding template-parameter then the program is 3293 // ill-formed. 3294 // 3295 // -- for a non-type template-parameter of integral or 3296 // enumeration type, integral promotions (4.5) and integral 3297 // conversions (4.7) are applied. 3298 QualType ParamType = InstantiatedParamType; 3299 QualType ArgType = Arg->getType(); 3300 if (ParamType->isIntegralOrEnumerationType()) { 3301 // C++ [temp.arg.nontype]p1: 3302 // A template-argument for a non-type, non-template 3303 // template-parameter shall be one of: 3304 // 3305 // -- an integral constant-expression of integral or enumeration 3306 // type; or 3307 // -- the name of a non-type template-parameter; or 3308 SourceLocation NonConstantLoc; 3309 llvm::APSInt Value; 3310 if (!ArgType->isIntegralOrEnumerationType()) { 3311 Diag(Arg->getSourceRange().getBegin(), 3312 diag::err_template_arg_not_integral_or_enumeral) 3313 << ArgType << Arg->getSourceRange(); 3314 Diag(Param->getLocation(), diag::note_template_param_here); 3315 return true; 3316 } else if (!Arg->isValueDependent() && 3317 !Arg->isIntegerConstantExpr(Value, Context, &NonConstantLoc)) { 3318 Diag(NonConstantLoc, diag::err_template_arg_not_ice) 3319 << ArgType << Arg->getSourceRange(); 3320 return true; 3321 } 3322 3323 // From here on out, all we care about are the unqualified forms 3324 // of the parameter and argument types. 3325 ParamType = ParamType.getUnqualifiedType(); 3326 ArgType = ArgType.getUnqualifiedType(); 3327 3328 // Try to convert the argument to the parameter's type. 3329 if (Context.hasSameType(ParamType, ArgType)) { 3330 // Okay: no conversion necessary 3331 } else if (CTAK == CTAK_Deduced) { 3332 // C++ [temp.deduct.type]p17: 3333 // If, in the declaration of a function template with a non-type 3334 // template-parameter, the non-type template- parameter is used 3335 // in an expression in the function parameter-list and, if the 3336 // corresponding template-argument is deduced, the 3337 // template-argument type shall match the type of the 3338 // template-parameter exactly, except that a template-argument 3339 // deduced from an array bound may be of any integral type. 3340 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch) 3341 << ArgType << ParamType; 3342 Diag(Param->getLocation(), diag::note_template_param_here); 3343 return true; 3344 } else if (ParamType->isBooleanType()) { 3345 // This is an integral-to-boolean conversion. 3346 ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean); 3347 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || 3348 !ParamType->isEnumeralType()) { 3349 // This is an integral promotion or conversion. 3350 ImpCastExprToType(Arg, ParamType, CK_IntegralCast); 3351 } else { 3352 // We can't perform this conversion. 3353 Diag(Arg->getSourceRange().getBegin(), 3354 diag::err_template_arg_not_convertible) 3355 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 3356 Diag(Param->getLocation(), diag::note_template_param_here); 3357 return true; 3358 } 3359 3360 QualType IntegerType = Context.getCanonicalType(ParamType); 3361 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 3362 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); 3363 3364 if (!Arg->isValueDependent()) { 3365 llvm::APSInt OldValue = Value; 3366 3367 // Coerce the template argument's value to the value it will have 3368 // based on the template parameter's type. 3369 unsigned AllowedBits = Context.getTypeSize(IntegerType); 3370 if (Value.getBitWidth() != AllowedBits) 3371 Value = Value.extOrTrunc(AllowedBits); 3372 Value.setIsSigned(IntegerType->isSignedIntegerType()); 3373 3374 // Complain if an unsigned parameter received a negative value. 3375 if (IntegerType->isUnsignedIntegerType() 3376 && (OldValue.isSigned() && OldValue.isNegative())) { 3377 Diag(Arg->getSourceRange().getBegin(), diag::warn_template_arg_negative) 3378 << OldValue.toString(10) << Value.toString(10) << Param->getType() 3379 << Arg->getSourceRange(); 3380 Diag(Param->getLocation(), diag::note_template_param_here); 3381 } 3382 3383 // Complain if we overflowed the template parameter's type. 3384 unsigned RequiredBits; 3385 if (IntegerType->isUnsignedIntegerType()) 3386 RequiredBits = OldValue.getActiveBits(); 3387 else if (OldValue.isUnsigned()) 3388 RequiredBits = OldValue.getActiveBits() + 1; 3389 else 3390 RequiredBits = OldValue.getMinSignedBits(); 3391 if (RequiredBits > AllowedBits) { 3392 Diag(Arg->getSourceRange().getBegin(), 3393 diag::warn_template_arg_too_large) 3394 << OldValue.toString(10) << Value.toString(10) << Param->getType() 3395 << Arg->getSourceRange(); 3396 Diag(Param->getLocation(), diag::note_template_param_here); 3397 } 3398 } 3399 3400 // Add the value of this argument to the list of converted 3401 // arguments. We use the bitwidth and signedness of the template 3402 // parameter. 3403 if (Arg->isValueDependent()) { 3404 // The argument is value-dependent. Create a new 3405 // TemplateArgument with the converted expression. 3406 Converted = TemplateArgument(Arg); 3407 return false; 3408 } 3409 3410 Converted = TemplateArgument(Value, 3411 ParamType->isEnumeralType() ? ParamType 3412 : IntegerType); 3413 return false; 3414 } 3415 3416 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction 3417 3418 // C++0x [temp.arg.nontype]p5 bullets 2, 4 and 6 permit conversion 3419 // from a template argument of type std::nullptr_t to a non-type 3420 // template parameter of type pointer to object, pointer to 3421 // function, or pointer-to-member, respectively. 3422 if (ArgType->isNullPtrType() && 3423 (ParamType->isPointerType() || ParamType->isMemberPointerType())) { 3424 Converted = TemplateArgument((NamedDecl *)0); 3425 return false; 3426 } 3427 3428 // Handle pointer-to-function, reference-to-function, and 3429 // pointer-to-member-function all in (roughly) the same way. 3430 if (// -- For a non-type template-parameter of type pointer to 3431 // function, only the function-to-pointer conversion (4.3) is 3432 // applied. If the template-argument represents a set of 3433 // overloaded functions (or a pointer to such), the matching 3434 // function is selected from the set (13.4). 3435 (ParamType->isPointerType() && 3436 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) || 3437 // -- For a non-type template-parameter of type reference to 3438 // function, no conversions apply. If the template-argument 3439 // represents a set of overloaded functions, the matching 3440 // function is selected from the set (13.4). 3441 (ParamType->isReferenceType() && 3442 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) || 3443 // -- For a non-type template-parameter of type pointer to 3444 // member function, no conversions apply. If the 3445 // template-argument represents a set of overloaded member 3446 // functions, the matching member function is selected from 3447 // the set (13.4). 3448 (ParamType->isMemberPointerType() && 3449 ParamType->getAs<MemberPointerType>()->getPointeeType() 3450 ->isFunctionType())) { 3451 3452 if (Arg->getType() == Context.OverloadTy) { 3453 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 3454 true, 3455 FoundResult)) { 3456 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 3457 return true; 3458 3459 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 3460 ArgType = Arg->getType(); 3461 } else 3462 return true; 3463 } 3464 3465 if (!ParamType->isMemberPointerType()) 3466 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 3467 ParamType, 3468 Arg, Converted); 3469 3470 if (IsQualificationConversion(ArgType, ParamType.getNonReferenceType(), 3471 false)) { 3472 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 3473 } else if (!Context.hasSameUnqualifiedType(ArgType, 3474 ParamType.getNonReferenceType())) { 3475 // We can't perform this conversion. 3476 Diag(Arg->getSourceRange().getBegin(), 3477 diag::err_template_arg_not_convertible) 3478 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 3479 Diag(Param->getLocation(), diag::note_template_param_here); 3480 return true; 3481 } 3482 3483 return CheckTemplateArgumentPointerToMember(Arg, Converted); 3484 } 3485 3486 if (ParamType->isPointerType()) { 3487 // -- for a non-type template-parameter of type pointer to 3488 // object, qualification conversions (4.4) and the 3489 // array-to-pointer conversion (4.2) are applied. 3490 // C++0x also allows a value of std::nullptr_t. 3491 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() && 3492 "Only object pointers allowed here"); 3493 3494 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 3495 ParamType, 3496 Arg, Converted); 3497 } 3498 3499 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { 3500 // -- For a non-type template-parameter of type reference to 3501 // object, no conversions apply. The type referred to by the 3502 // reference may be more cv-qualified than the (otherwise 3503 // identical) type of the template-argument. The 3504 // template-parameter is bound directly to the 3505 // template-argument, which must be an lvalue. 3506 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() && 3507 "Only object references allowed here"); 3508 3509 if (Arg->getType() == Context.OverloadTy) { 3510 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 3511 ParamRefType->getPointeeType(), 3512 true, 3513 FoundResult)) { 3514 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 3515 return true; 3516 3517 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 3518 ArgType = Arg->getType(); 3519 } else 3520 return true; 3521 } 3522 3523 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 3524 ParamType, 3525 Arg, Converted); 3526 } 3527 3528 // -- For a non-type template-parameter of type pointer to data 3529 // member, qualification conversions (4.4) are applied. 3530 assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); 3531 3532 if (Context.hasSameUnqualifiedType(ParamType, ArgType)) { 3533 // Types match exactly: nothing more to do here. 3534 } else if (IsQualificationConversion(ArgType, ParamType, false)) { 3535 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 3536 } else { 3537 // We can't perform this conversion. 3538 Diag(Arg->getSourceRange().getBegin(), 3539 diag::err_template_arg_not_convertible) 3540 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 3541 Diag(Param->getLocation(), diag::note_template_param_here); 3542 return true; 3543 } 3544 3545 return CheckTemplateArgumentPointerToMember(Arg, Converted); 3546} 3547 3548/// \brief Check a template argument against its corresponding 3549/// template template parameter. 3550/// 3551/// This routine implements the semantics of C++ [temp.arg.template]. 3552/// It returns true if an error occurred, and false otherwise. 3553bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, 3554 const TemplateArgumentLoc &Arg) { 3555 TemplateName Name = Arg.getArgument().getAsTemplate(); 3556 TemplateDecl *Template = Name.getAsTemplateDecl(); 3557 if (!Template) { 3558 // Any dependent template name is fine. 3559 assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); 3560 return false; 3561 } 3562 3563 // C++ [temp.arg.template]p1: 3564 // A template-argument for a template template-parameter shall be 3565 // the name of a class template, expressed as id-expression. Only 3566 // primary class templates are considered when matching the 3567 // template template argument with the corresponding parameter; 3568 // partial specializations are not considered even if their 3569 // parameter lists match that of the template template parameter. 3570 // 3571 // Note that we also allow template template parameters here, which 3572 // will happen when we are dealing with, e.g., class template 3573 // partial specializations. 3574 if (!isa<ClassTemplateDecl>(Template) && 3575 !isa<TemplateTemplateParmDecl>(Template)) { 3576 assert(isa<FunctionTemplateDecl>(Template) && 3577 "Only function templates are possible here"); 3578 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); 3579 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) 3580 << Template; 3581 } 3582 3583 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), 3584 Param->getTemplateParameters(), 3585 true, 3586 TPL_TemplateTemplateArgumentMatch, 3587 Arg.getLocation()); 3588} 3589 3590/// \brief Given a non-type template argument that refers to a 3591/// declaration and the type of its corresponding non-type template 3592/// parameter, produce an expression that properly refers to that 3593/// declaration. 3594ExprResult 3595Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg, 3596 QualType ParamType, 3597 SourceLocation Loc) { 3598 assert(Arg.getKind() == TemplateArgument::Declaration && 3599 "Only declaration template arguments permitted here"); 3600 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl()); 3601 3602 if (VD->getDeclContext()->isRecord() && 3603 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD))) { 3604 // If the value is a class member, we might have a pointer-to-member. 3605 // Determine whether the non-type template template parameter is of 3606 // pointer-to-member type. If so, we need to build an appropriate 3607 // expression for a pointer-to-member, since a "normal" DeclRefExpr 3608 // would refer to the member itself. 3609 if (ParamType->isMemberPointerType()) { 3610 QualType ClassType 3611 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext())); 3612 NestedNameSpecifier *Qualifier 3613 = NestedNameSpecifier::Create(Context, 0, false, 3614 ClassType.getTypePtr()); 3615 CXXScopeSpec SS; 3616 SS.MakeTrivial(Context, Qualifier, Loc); 3617 3618 // The actual value-ness of this is unimportant, but for 3619 // internal consistency's sake, references to instance methods 3620 // are r-values. 3621 ExprValueKind VK = VK_LValue; 3622 if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance()) 3623 VK = VK_RValue; 3624 3625 ExprResult RefExpr = BuildDeclRefExpr(VD, 3626 VD->getType().getNonReferenceType(), 3627 VK, 3628 Loc, 3629 &SS); 3630 if (RefExpr.isInvalid()) 3631 return ExprError(); 3632 3633 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3634 3635 // We might need to perform a trailing qualification conversion, since 3636 // the element type on the parameter could be more qualified than the 3637 // element type in the expression we constructed. 3638 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(), 3639 ParamType.getUnqualifiedType(), false)) { 3640 Expr *RefE = RefExpr.takeAs<Expr>(); 3641 ImpCastExprToType(RefE, ParamType.getUnqualifiedType(), CK_NoOp); 3642 RefExpr = Owned(RefE); 3643 } 3644 3645 assert(!RefExpr.isInvalid() && 3646 Context.hasSameType(((Expr*) RefExpr.get())->getType(), 3647 ParamType.getUnqualifiedType())); 3648 return move(RefExpr); 3649 } 3650 } 3651 3652 QualType T = VD->getType().getNonReferenceType(); 3653 if (ParamType->isPointerType()) { 3654 // When the non-type template parameter is a pointer, take the 3655 // address of the declaration. 3656 ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc); 3657 if (RefExpr.isInvalid()) 3658 return ExprError(); 3659 3660 if (T->isFunctionType() || T->isArrayType()) { 3661 // Decay functions and arrays. 3662 Expr *RefE = (Expr *)RefExpr.get(); 3663 DefaultFunctionArrayConversion(RefE); 3664 if (RefE != RefExpr.get()) { 3665 RefExpr.release(); 3666 RefExpr = Owned(RefE); 3667 } 3668 3669 return move(RefExpr); 3670 } 3671 3672 // Take the address of everything else 3673 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3674 } 3675 3676 ExprValueKind VK = VK_RValue; 3677 3678 // If the non-type template parameter has reference type, qualify the 3679 // resulting declaration reference with the extra qualifiers on the 3680 // type that the reference refers to. 3681 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) { 3682 VK = VK_LValue; 3683 T = Context.getQualifiedType(T, 3684 TargetRef->getPointeeType().getQualifiers()); 3685 } 3686 3687 return BuildDeclRefExpr(VD, T, VK, Loc); 3688} 3689 3690/// \brief Construct a new expression that refers to the given 3691/// integral template argument with the given source-location 3692/// information. 3693/// 3694/// This routine takes care of the mapping from an integral template 3695/// argument (which may have any integral type) to the appropriate 3696/// literal value. 3697ExprResult 3698Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg, 3699 SourceLocation Loc) { 3700 assert(Arg.getKind() == TemplateArgument::Integral && 3701 "Operation is only valid for integral template arguments"); 3702 QualType T = Arg.getIntegralType(); 3703 if (T->isCharType() || T->isWideCharType()) 3704 return Owned(new (Context) CharacterLiteral( 3705 Arg.getAsIntegral()->getZExtValue(), 3706 T->isWideCharType(), 3707 T, 3708 Loc)); 3709 if (T->isBooleanType()) 3710 return Owned(new (Context) CXXBoolLiteralExpr( 3711 Arg.getAsIntegral()->getBoolValue(), 3712 T, 3713 Loc)); 3714 3715 QualType BT; 3716 if (const EnumType *ET = T->getAs<EnumType>()) 3717 BT = ET->getDecl()->getPromotionType(); 3718 else 3719 BT = T; 3720 3721 Expr *E = IntegerLiteral::Create(Context, *Arg.getAsIntegral(), BT, Loc); 3722 if (T->isEnumeralType()) { 3723 // FIXME: This is a hack. We need a better way to handle substituted 3724 // non-type template parameters. 3725 E = CStyleCastExpr::Create(Context, T, VK_RValue, CK_IntegralCast, 3726 E, 0, 3727 Context.getTrivialTypeSourceInfo(T, Loc), 3728 Loc, Loc); 3729 } 3730 3731 return Owned(E); 3732} 3733 3734/// \brief Match two template parameters within template parameter lists. 3735static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old, 3736 bool Complain, 3737 Sema::TemplateParameterListEqualKind Kind, 3738 SourceLocation TemplateArgLoc) { 3739 // Check the actual kind (type, non-type, template). 3740 if (Old->getKind() != New->getKind()) { 3741 if (Complain) { 3742 unsigned NextDiag = diag::err_template_param_different_kind; 3743 if (TemplateArgLoc.isValid()) { 3744 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3745 NextDiag = diag::note_template_param_different_kind; 3746 } 3747 S.Diag(New->getLocation(), NextDiag) 3748 << (Kind != Sema::TPL_TemplateMatch); 3749 S.Diag(Old->getLocation(), diag::note_template_prev_declaration) 3750 << (Kind != Sema::TPL_TemplateMatch); 3751 } 3752 3753 return false; 3754 } 3755 3756 // Check that both are parameter packs are neither are parameter packs. 3757 // However, if we are matching a template template argument to a 3758 // template template parameter, the template template parameter can have 3759 // a parameter pack where the template template argument does not. 3760 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() && 3761 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch && 3762 Old->isTemplateParameterPack())) { 3763 if (Complain) { 3764 unsigned NextDiag = diag::err_template_parameter_pack_non_pack; 3765 if (TemplateArgLoc.isValid()) { 3766 S.Diag(TemplateArgLoc, 3767 diag::err_template_arg_template_params_mismatch); 3768 NextDiag = diag::note_template_parameter_pack_non_pack; 3769 } 3770 3771 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0 3772 : isa<NonTypeTemplateParmDecl>(New)? 1 3773 : 2; 3774 S.Diag(New->getLocation(), NextDiag) 3775 << ParamKind << New->isParameterPack(); 3776 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here) 3777 << ParamKind << Old->isParameterPack(); 3778 } 3779 3780 return false; 3781 } 3782 3783 // For non-type template parameters, check the type of the parameter. 3784 if (NonTypeTemplateParmDecl *OldNTTP 3785 = dyn_cast<NonTypeTemplateParmDecl>(Old)) { 3786 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New); 3787 3788 // If we are matching a template template argument to a template 3789 // template parameter and one of the non-type template parameter types 3790 // is dependent, then we must wait until template instantiation time 3791 // to actually compare the arguments. 3792 if (Kind == Sema::TPL_TemplateTemplateArgumentMatch && 3793 (OldNTTP->getType()->isDependentType() || 3794 NewNTTP->getType()->isDependentType())) 3795 return true; 3796 3797 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) { 3798 if (Complain) { 3799 unsigned NextDiag = diag::err_template_nontype_parm_different_type; 3800 if (TemplateArgLoc.isValid()) { 3801 S.Diag(TemplateArgLoc, 3802 diag::err_template_arg_template_params_mismatch); 3803 NextDiag = diag::note_template_nontype_parm_different_type; 3804 } 3805 S.Diag(NewNTTP->getLocation(), NextDiag) 3806 << NewNTTP->getType() 3807 << (Kind != Sema::TPL_TemplateMatch); 3808 S.Diag(OldNTTP->getLocation(), 3809 diag::note_template_nontype_parm_prev_declaration) 3810 << OldNTTP->getType(); 3811 } 3812 3813 return false; 3814 } 3815 3816 return true; 3817 } 3818 3819 // For template template parameters, check the template parameter types. 3820 // The template parameter lists of template template 3821 // parameters must agree. 3822 if (TemplateTemplateParmDecl *OldTTP 3823 = dyn_cast<TemplateTemplateParmDecl>(Old)) { 3824 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New); 3825 return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), 3826 OldTTP->getTemplateParameters(), 3827 Complain, 3828 (Kind == Sema::TPL_TemplateMatch 3829 ? Sema::TPL_TemplateTemplateParmMatch 3830 : Kind), 3831 TemplateArgLoc); 3832 } 3833 3834 return true; 3835} 3836 3837/// \brief Diagnose a known arity mismatch when comparing template argument 3838/// lists. 3839static 3840void DiagnoseTemplateParameterListArityMismatch(Sema &S, 3841 TemplateParameterList *New, 3842 TemplateParameterList *Old, 3843 Sema::TemplateParameterListEqualKind Kind, 3844 SourceLocation TemplateArgLoc) { 3845 unsigned NextDiag = diag::err_template_param_list_different_arity; 3846 if (TemplateArgLoc.isValid()) { 3847 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3848 NextDiag = diag::note_template_param_list_different_arity; 3849 } 3850 S.Diag(New->getTemplateLoc(), NextDiag) 3851 << (New->size() > Old->size()) 3852 << (Kind != Sema::TPL_TemplateMatch) 3853 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); 3854 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) 3855 << (Kind != Sema::TPL_TemplateMatch) 3856 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); 3857} 3858 3859/// \brief Determine whether the given template parameter lists are 3860/// equivalent. 3861/// 3862/// \param New The new template parameter list, typically written in the 3863/// source code as part of a new template declaration. 3864/// 3865/// \param Old The old template parameter list, typically found via 3866/// name lookup of the template declared with this template parameter 3867/// list. 3868/// 3869/// \param Complain If true, this routine will produce a diagnostic if 3870/// the template parameter lists are not equivalent. 3871/// 3872/// \param Kind describes how we are to match the template parameter lists. 3873/// 3874/// \param TemplateArgLoc If this source location is valid, then we 3875/// are actually checking the template parameter list of a template 3876/// argument (New) against the template parameter list of its 3877/// corresponding template template parameter (Old). We produce 3878/// slightly different diagnostics in this scenario. 3879/// 3880/// \returns True if the template parameter lists are equal, false 3881/// otherwise. 3882bool 3883Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, 3884 TemplateParameterList *Old, 3885 bool Complain, 3886 TemplateParameterListEqualKind Kind, 3887 SourceLocation TemplateArgLoc) { 3888 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) { 3889 if (Complain) 3890 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 3891 TemplateArgLoc); 3892 3893 return false; 3894 } 3895 3896 // C++0x [temp.arg.template]p3: 3897 // A template-argument matches a template template-parameter (call it P) 3898 // when each of the template parameters in the template-parameter-list of 3899 // the template-argument's corresponding class template or template alias 3900 // (call it A) matches the corresponding template parameter in the 3901 // template-parameter-list of P. [...] 3902 TemplateParameterList::iterator NewParm = New->begin(); 3903 TemplateParameterList::iterator NewParmEnd = New->end(); 3904 for (TemplateParameterList::iterator OldParm = Old->begin(), 3905 OldParmEnd = Old->end(); 3906 OldParm != OldParmEnd; ++OldParm) { 3907 if (Kind != TPL_TemplateTemplateArgumentMatch || 3908 !(*OldParm)->isTemplateParameterPack()) { 3909 if (NewParm == NewParmEnd) { 3910 if (Complain) 3911 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 3912 TemplateArgLoc); 3913 3914 return false; 3915 } 3916 3917 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, 3918 Kind, TemplateArgLoc)) 3919 return false; 3920 3921 ++NewParm; 3922 continue; 3923 } 3924 3925 // C++0x [temp.arg.template]p3: 3926 // [...] When P's template- parameter-list contains a template parameter 3927 // pack (14.5.3), the template parameter pack will match zero or more 3928 // template parameters or template parameter packs in the 3929 // template-parameter-list of A with the same type and form as the 3930 // template parameter pack in P (ignoring whether those template 3931 // parameters are template parameter packs). 3932 for (; NewParm != NewParmEnd; ++NewParm) { 3933 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, 3934 Kind, TemplateArgLoc)) 3935 return false; 3936 } 3937 } 3938 3939 // Make sure we exhausted all of the arguments. 3940 if (NewParm != NewParmEnd) { 3941 if (Complain) 3942 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, 3943 TemplateArgLoc); 3944 3945 return false; 3946 } 3947 3948 return true; 3949} 3950 3951/// \brief Check whether a template can be declared within this scope. 3952/// 3953/// If the template declaration is valid in this scope, returns 3954/// false. Otherwise, issues a diagnostic and returns true. 3955bool 3956Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { 3957 // Find the nearest enclosing declaration scope. 3958 while ((S->getFlags() & Scope::DeclScope) == 0 || 3959 (S->getFlags() & Scope::TemplateParamScope) != 0) 3960 S = S->getParent(); 3961 3962 // C++ [temp]p2: 3963 // A template-declaration can appear only as a namespace scope or 3964 // class scope declaration. 3965 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 3966 if (Ctx && isa<LinkageSpecDecl>(Ctx) && 3967 cast<LinkageSpecDecl>(Ctx)->getLanguage() != LinkageSpecDecl::lang_cxx) 3968 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) 3969 << TemplateParams->getSourceRange(); 3970 3971 while (Ctx && isa<LinkageSpecDecl>(Ctx)) 3972 Ctx = Ctx->getParent(); 3973 3974 if (Ctx && (Ctx->isFileContext() || Ctx->isRecord())) 3975 return false; 3976 3977 return Diag(TemplateParams->getTemplateLoc(), 3978 diag::err_template_outside_namespace_or_class_scope) 3979 << TemplateParams->getSourceRange(); 3980} 3981 3982/// \brief Determine what kind of template specialization the given declaration 3983/// is. 3984static TemplateSpecializationKind getTemplateSpecializationKind(NamedDecl *D) { 3985 if (!D) 3986 return TSK_Undeclared; 3987 3988 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) 3989 return Record->getTemplateSpecializationKind(); 3990 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) 3991 return Function->getTemplateSpecializationKind(); 3992 if (VarDecl *Var = dyn_cast<VarDecl>(D)) 3993 return Var->getTemplateSpecializationKind(); 3994 3995 return TSK_Undeclared; 3996} 3997 3998/// \brief Check whether a specialization is well-formed in the current 3999/// context. 4000/// 4001/// This routine determines whether a template specialization can be declared 4002/// in the current context (C++ [temp.expl.spec]p2). 4003/// 4004/// \param S the semantic analysis object for which this check is being 4005/// performed. 4006/// 4007/// \param Specialized the entity being specialized or instantiated, which 4008/// may be a kind of template (class template, function template, etc.) or 4009/// a member of a class template (member function, static data member, 4010/// member class). 4011/// 4012/// \param PrevDecl the previous declaration of this entity, if any. 4013/// 4014/// \param Loc the location of the explicit specialization or instantiation of 4015/// this entity. 4016/// 4017/// \param IsPartialSpecialization whether this is a partial specialization of 4018/// a class template. 4019/// 4020/// \returns true if there was an error that we cannot recover from, false 4021/// otherwise. 4022static bool CheckTemplateSpecializationScope(Sema &S, 4023 NamedDecl *Specialized, 4024 NamedDecl *PrevDecl, 4025 SourceLocation Loc, 4026 bool IsPartialSpecialization) { 4027 // Keep these "kind" numbers in sync with the %select statements in the 4028 // various diagnostics emitted by this routine. 4029 int EntityKind = 0; 4030 if (isa<ClassTemplateDecl>(Specialized)) 4031 EntityKind = IsPartialSpecialization? 1 : 0; 4032 else if (isa<FunctionTemplateDecl>(Specialized)) 4033 EntityKind = 2; 4034 else if (isa<CXXMethodDecl>(Specialized)) 4035 EntityKind = 3; 4036 else if (isa<VarDecl>(Specialized)) 4037 EntityKind = 4; 4038 else if (isa<RecordDecl>(Specialized)) 4039 EntityKind = 5; 4040 else { 4041 S.Diag(Loc, diag::err_template_spec_unknown_kind); 4042 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 4043 return true; 4044 } 4045 4046 // C++ [temp.expl.spec]p2: 4047 // An explicit specialization shall be declared in the namespace 4048 // of which the template is a member, or, for member templates, in 4049 // the namespace of which the enclosing class or enclosing class 4050 // template is a member. An explicit specialization of a member 4051 // function, member class or static data member of a class 4052 // template shall be declared in the namespace of which the class 4053 // template is a member. Such a declaration may also be a 4054 // definition. If the declaration is not a definition, the 4055 // specialization may be defined later in the name- space in which 4056 // the explicit specialization was declared, or in a namespace 4057 // that encloses the one in which the explicit specialization was 4058 // declared. 4059 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) { 4060 S.Diag(Loc, diag::err_template_spec_decl_function_scope) 4061 << Specialized; 4062 return true; 4063 } 4064 4065 if (S.CurContext->isRecord() && !IsPartialSpecialization) { 4066 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 4067 << Specialized; 4068 return true; 4069 } 4070 4071 // C++ [temp.class.spec]p6: 4072 // A class template partial specialization may be declared or redeclared 4073 // in any namespace scope in which its definition may be defined (14.5.1 4074 // and 14.5.2). 4075 bool ComplainedAboutScope = false; 4076 DeclContext *SpecializedContext 4077 = Specialized->getDeclContext()->getEnclosingNamespaceContext(); 4078 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); 4079 if ((!PrevDecl || 4080 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || 4081 getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)){ 4082 // C++ [temp.exp.spec]p2: 4083 // An explicit specialization shall be declared in the namespace of which 4084 // the template is a member, or, for member templates, in the namespace 4085 // of which the enclosing class or enclosing class template is a member. 4086 // An explicit specialization of a member function, member class or 4087 // static data member of a class template shall be declared in the 4088 // namespace of which the class template is a member. 4089 // 4090 // C++0x [temp.expl.spec]p2: 4091 // An explicit specialization shall be declared in a namespace enclosing 4092 // the specialized template. 4093 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext) && 4094 !(S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext))) { 4095 bool IsCPlusPlus0xExtension 4096 = !S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext); 4097 if (isa<TranslationUnitDecl>(SpecializedContext)) 4098 S.Diag(Loc, IsCPlusPlus0xExtension 4099 ? diag::ext_template_spec_decl_out_of_scope_global 4100 : diag::err_template_spec_decl_out_of_scope_global) 4101 << EntityKind << Specialized; 4102 else if (isa<NamespaceDecl>(SpecializedContext)) 4103 S.Diag(Loc, IsCPlusPlus0xExtension 4104 ? diag::ext_template_spec_decl_out_of_scope 4105 : diag::err_template_spec_decl_out_of_scope) 4106 << EntityKind << Specialized 4107 << cast<NamedDecl>(SpecializedContext); 4108 4109 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 4110 ComplainedAboutScope = true; 4111 } 4112 } 4113 4114 // Make sure that this redeclaration (or definition) occurs in an enclosing 4115 // namespace. 4116 // Note that HandleDeclarator() performs this check for explicit 4117 // specializations of function templates, static data members, and member 4118 // functions, so we skip the check here for those kinds of entities. 4119 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. 4120 // Should we refactor that check, so that it occurs later? 4121 if (!ComplainedAboutScope && !DC->Encloses(SpecializedContext) && 4122 !(isa<FunctionTemplateDecl>(Specialized) || isa<VarDecl>(Specialized) || 4123 isa<FunctionDecl>(Specialized))) { 4124 if (isa<TranslationUnitDecl>(SpecializedContext)) 4125 S.Diag(Loc, diag::err_template_spec_redecl_global_scope) 4126 << EntityKind << Specialized; 4127 else if (isa<NamespaceDecl>(SpecializedContext)) 4128 S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope) 4129 << EntityKind << Specialized 4130 << cast<NamedDecl>(SpecializedContext); 4131 4132 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 4133 } 4134 4135 // FIXME: check for specialization-after-instantiation errors and such. 4136 4137 return false; 4138} 4139 4140/// \brief Subroutine of Sema::CheckClassTemplatePartialSpecializationArgs 4141/// that checks non-type template partial specialization arguments. 4142static bool CheckNonTypeClassTemplatePartialSpecializationArgs(Sema &S, 4143 NonTypeTemplateParmDecl *Param, 4144 const TemplateArgument *Args, 4145 unsigned NumArgs) { 4146 for (unsigned I = 0; I != NumArgs; ++I) { 4147 if (Args[I].getKind() == TemplateArgument::Pack) { 4148 if (CheckNonTypeClassTemplatePartialSpecializationArgs(S, Param, 4149 Args[I].pack_begin(), 4150 Args[I].pack_size())) 4151 return true; 4152 4153 continue; 4154 } 4155 4156 Expr *ArgExpr = Args[I].getAsExpr(); 4157 if (!ArgExpr) { 4158 continue; 4159 } 4160 4161 // We can have a pack expansion of any of the bullets below. 4162 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr)) 4163 ArgExpr = Expansion->getPattern(); 4164 4165 // Strip off any implicit casts we added as part of type checking. 4166 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr)) 4167 ArgExpr = ICE->getSubExpr(); 4168 4169 // C++ [temp.class.spec]p8: 4170 // A non-type argument is non-specialized if it is the name of a 4171 // non-type parameter. All other non-type arguments are 4172 // specialized. 4173 // 4174 // Below, we check the two conditions that only apply to 4175 // specialized non-type arguments, so skip any non-specialized 4176 // arguments. 4177 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr)) 4178 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl())) 4179 continue; 4180 4181 // C++ [temp.class.spec]p9: 4182 // Within the argument list of a class template partial 4183 // specialization, the following restrictions apply: 4184 // -- A partially specialized non-type argument expression 4185 // shall not involve a template parameter of the partial 4186 // specialization except when the argument expression is a 4187 // simple identifier. 4188 if (ArgExpr->isTypeDependent() || ArgExpr->isValueDependent()) { 4189 S.Diag(ArgExpr->getLocStart(), 4190 diag::err_dependent_non_type_arg_in_partial_spec) 4191 << ArgExpr->getSourceRange(); 4192 return true; 4193 } 4194 4195 // -- The type of a template parameter corresponding to a 4196 // specialized non-type argument shall not be dependent on a 4197 // parameter of the specialization. 4198 if (Param->getType()->isDependentType()) { 4199 S.Diag(ArgExpr->getLocStart(), 4200 diag::err_dependent_typed_non_type_arg_in_partial_spec) 4201 << Param->getType() 4202 << ArgExpr->getSourceRange(); 4203 S.Diag(Param->getLocation(), diag::note_template_param_here); 4204 return true; 4205 } 4206 } 4207 4208 return false; 4209} 4210 4211/// \brief Check the non-type template arguments of a class template 4212/// partial specialization according to C++ [temp.class.spec]p9. 4213/// 4214/// \param TemplateParams the template parameters of the primary class 4215/// template. 4216/// 4217/// \param TemplateArg the template arguments of the class template 4218/// partial specialization. 4219/// 4220/// \returns true if there was an error, false otherwise. 4221static bool CheckClassTemplatePartialSpecializationArgs(Sema &S, 4222 TemplateParameterList *TemplateParams, 4223 llvm::SmallVectorImpl<TemplateArgument> &TemplateArgs) { 4224 const TemplateArgument *ArgList = TemplateArgs.data(); 4225 4226 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 4227 NonTypeTemplateParmDecl *Param 4228 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I)); 4229 if (!Param) 4230 continue; 4231 4232 if (CheckNonTypeClassTemplatePartialSpecializationArgs(S, Param, 4233 &ArgList[I], 1)) 4234 return true; 4235 } 4236 4237 return false; 4238} 4239 4240/// \brief Retrieve the previous declaration of the given declaration. 4241static NamedDecl *getPreviousDecl(NamedDecl *ND) { 4242 if (VarDecl *VD = dyn_cast<VarDecl>(ND)) 4243 return VD->getPreviousDeclaration(); 4244 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 4245 return FD->getPreviousDeclaration(); 4246 if (TagDecl *TD = dyn_cast<TagDecl>(ND)) 4247 return TD->getPreviousDeclaration(); 4248 if (TypedefDecl *TD = dyn_cast<TypedefDecl>(ND)) 4249 return TD->getPreviousDeclaration(); 4250 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 4251 return FTD->getPreviousDeclaration(); 4252 if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND)) 4253 return CTD->getPreviousDeclaration(); 4254 return 0; 4255} 4256 4257DeclResult 4258Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, 4259 TagUseKind TUK, 4260 SourceLocation KWLoc, 4261 CXXScopeSpec &SS, 4262 TemplateTy TemplateD, 4263 SourceLocation TemplateNameLoc, 4264 SourceLocation LAngleLoc, 4265 ASTTemplateArgsPtr TemplateArgsIn, 4266 SourceLocation RAngleLoc, 4267 AttributeList *Attr, 4268 MultiTemplateParamsArg TemplateParameterLists) { 4269 assert(TUK != TUK_Reference && "References are not specializations"); 4270 4271 // Find the class template we're specializing 4272 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 4273 ClassTemplateDecl *ClassTemplate 4274 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl()); 4275 4276 if (!ClassTemplate) { 4277 Diag(TemplateNameLoc, diag::err_not_class_template_specialization) 4278 << (Name.getAsTemplateDecl() && 4279 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())); 4280 return true; 4281 } 4282 4283 bool isExplicitSpecialization = false; 4284 bool isPartialSpecialization = false; 4285 4286 // Check the validity of the template headers that introduce this 4287 // template. 4288 // FIXME: We probably shouldn't complain about these headers for 4289 // friend declarations. 4290 bool Invalid = false; 4291 TemplateParameterList *TemplateParams 4292 = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, SS, 4293 (TemplateParameterList**)TemplateParameterLists.get(), 4294 TemplateParameterLists.size(), 4295 TUK == TUK_Friend, 4296 isExplicitSpecialization, 4297 Invalid); 4298 if (Invalid) 4299 return true; 4300 4301 unsigned NumMatchedTemplateParamLists = TemplateParameterLists.size(); 4302 if (TemplateParams) 4303 --NumMatchedTemplateParamLists; 4304 4305 if (TemplateParams && TemplateParams->size() > 0) { 4306 isPartialSpecialization = true; 4307 4308 if (TUK == TUK_Friend) { 4309 Diag(KWLoc, diag::err_partial_specialization_friend) 4310 << SourceRange(LAngleLoc, RAngleLoc); 4311 return true; 4312 } 4313 4314 // C++ [temp.class.spec]p10: 4315 // The template parameter list of a specialization shall not 4316 // contain default template argument values. 4317 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 4318 Decl *Param = TemplateParams->getParam(I); 4319 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) { 4320 if (TTP->hasDefaultArgument()) { 4321 Diag(TTP->getDefaultArgumentLoc(), 4322 diag::err_default_arg_in_partial_spec); 4323 TTP->removeDefaultArgument(); 4324 } 4325 } else if (NonTypeTemplateParmDecl *NTTP 4326 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 4327 if (Expr *DefArg = NTTP->getDefaultArgument()) { 4328 Diag(NTTP->getDefaultArgumentLoc(), 4329 diag::err_default_arg_in_partial_spec) 4330 << DefArg->getSourceRange(); 4331 NTTP->removeDefaultArgument(); 4332 } 4333 } else { 4334 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param); 4335 if (TTP->hasDefaultArgument()) { 4336 Diag(TTP->getDefaultArgument().getLocation(), 4337 diag::err_default_arg_in_partial_spec) 4338 << TTP->getDefaultArgument().getSourceRange(); 4339 TTP->removeDefaultArgument(); 4340 } 4341 } 4342 } 4343 } else if (TemplateParams) { 4344 if (TUK == TUK_Friend) 4345 Diag(KWLoc, diag::err_template_spec_friend) 4346 << FixItHint::CreateRemoval( 4347 SourceRange(TemplateParams->getTemplateLoc(), 4348 TemplateParams->getRAngleLoc())) 4349 << SourceRange(LAngleLoc, RAngleLoc); 4350 else 4351 isExplicitSpecialization = true; 4352 } else if (TUK != TUK_Friend) { 4353 Diag(KWLoc, diag::err_template_spec_needs_header) 4354 << FixItHint::CreateInsertion(KWLoc, "template<> "); 4355 isExplicitSpecialization = true; 4356 } 4357 4358 // Check that the specialization uses the same tag kind as the 4359 // original template. 4360 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 4361 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!"); 4362 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 4363 Kind, KWLoc, 4364 *ClassTemplate->getIdentifier())) { 4365 Diag(KWLoc, diag::err_use_with_wrong_tag) 4366 << ClassTemplate 4367 << FixItHint::CreateReplacement(KWLoc, 4368 ClassTemplate->getTemplatedDecl()->getKindName()); 4369 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 4370 diag::note_previous_use); 4371 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 4372 } 4373 4374 // Translate the parser's template argument list in our AST format. 4375 TemplateArgumentListInfo TemplateArgs; 4376 TemplateArgs.setLAngleLoc(LAngleLoc); 4377 TemplateArgs.setRAngleLoc(RAngleLoc); 4378 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 4379 4380 // Check for unexpanded parameter packs in any of the template arguments. 4381 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 4382 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I], 4383 UPPC_PartialSpecialization)) 4384 return true; 4385 4386 // Check that the template argument list is well-formed for this 4387 // template. 4388 llvm::SmallVector<TemplateArgument, 4> Converted; 4389 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 4390 TemplateArgs, false, Converted)) 4391 return true; 4392 4393 assert((Converted.size() == ClassTemplate->getTemplateParameters()->size()) && 4394 "Converted template argument list is too short!"); 4395 4396 // Find the class template (partial) specialization declaration that 4397 // corresponds to these arguments. 4398 if (isPartialSpecialization) { 4399 if (CheckClassTemplatePartialSpecializationArgs(*this, 4400 ClassTemplate->getTemplateParameters(), 4401 Converted)) 4402 return true; 4403 4404 if (!Name.isDependent() && 4405 !TemplateSpecializationType::anyDependentTemplateArguments( 4406 TemplateArgs.getArgumentArray(), 4407 TemplateArgs.size())) { 4408 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) 4409 << ClassTemplate->getDeclName(); 4410 isPartialSpecialization = false; 4411 } 4412 } 4413 4414 void *InsertPos = 0; 4415 ClassTemplateSpecializationDecl *PrevDecl = 0; 4416 4417 if (isPartialSpecialization) 4418 // FIXME: Template parameter list matters, too 4419 PrevDecl 4420 = ClassTemplate->findPartialSpecialization(Converted.data(), 4421 Converted.size(), 4422 InsertPos); 4423 else 4424 PrevDecl 4425 = ClassTemplate->findSpecialization(Converted.data(), 4426 Converted.size(), InsertPos); 4427 4428 ClassTemplateSpecializationDecl *Specialization = 0; 4429 4430 // Check whether we can declare a class template specialization in 4431 // the current scope. 4432 if (TUK != TUK_Friend && 4433 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl, 4434 TemplateNameLoc, 4435 isPartialSpecialization)) 4436 return true; 4437 4438 // The canonical type 4439 QualType CanonType; 4440 if (PrevDecl && 4441 (PrevDecl->getSpecializationKind() == TSK_Undeclared || 4442 TUK == TUK_Friend)) { 4443 // Since the only prior class template specialization with these 4444 // arguments was referenced but not declared, or we're only 4445 // referencing this specialization as a friend, reuse that 4446 // declaration node as our own, updating its source location to 4447 // reflect our new declaration. 4448 Specialization = PrevDecl; 4449 Specialization->setLocation(TemplateNameLoc); 4450 PrevDecl = 0; 4451 CanonType = Context.getTypeDeclType(Specialization); 4452 } else if (isPartialSpecialization) { 4453 // Build the canonical type that describes the converted template 4454 // arguments of the class template partial specialization. 4455 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 4456 CanonType = Context.getTemplateSpecializationType(CanonTemplate, 4457 Converted.data(), 4458 Converted.size()); 4459 4460 if (Context.hasSameType(CanonType, 4461 ClassTemplate->getInjectedClassNameSpecialization())) { 4462 // C++ [temp.class.spec]p9b3: 4463 // 4464 // -- The argument list of the specialization shall not be identical 4465 // to the implicit argument list of the primary template. 4466 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 4467 << (TUK == TUK_Definition) 4468 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); 4469 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS, 4470 ClassTemplate->getIdentifier(), 4471 TemplateNameLoc, 4472 Attr, 4473 TemplateParams, 4474 AS_none); 4475 } 4476 4477 // Create a new class template partial specialization declaration node. 4478 ClassTemplatePartialSpecializationDecl *PrevPartial 4479 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl); 4480 unsigned SequenceNumber = PrevPartial? PrevPartial->getSequenceNumber() 4481 : ClassTemplate->getNextPartialSpecSequenceNumber(); 4482 ClassTemplatePartialSpecializationDecl *Partial 4483 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind, 4484 ClassTemplate->getDeclContext(), 4485 TemplateNameLoc, 4486 TemplateParams, 4487 ClassTemplate, 4488 Converted.data(), 4489 Converted.size(), 4490 TemplateArgs, 4491 CanonType, 4492 PrevPartial, 4493 SequenceNumber); 4494 SetNestedNameSpecifier(Partial, SS); 4495 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 4496 Partial->setTemplateParameterListsInfo(Context, 4497 NumMatchedTemplateParamLists, 4498 (TemplateParameterList**) TemplateParameterLists.release()); 4499 } 4500 4501 if (!PrevPartial) 4502 ClassTemplate->AddPartialSpecialization(Partial, InsertPos); 4503 Specialization = Partial; 4504 4505 // If we are providing an explicit specialization of a member class 4506 // template specialization, make a note of that. 4507 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 4508 PrevPartial->setMemberSpecialization(); 4509 4510 // Check that all of the template parameters of the class template 4511 // partial specialization are deducible from the template 4512 // arguments. If not, this class template partial specialization 4513 // will never be used. 4514 llvm::SmallVector<bool, 8> DeducibleParams; 4515 DeducibleParams.resize(TemplateParams->size()); 4516 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 4517 TemplateParams->getDepth(), 4518 DeducibleParams); 4519 unsigned NumNonDeducible = 0; 4520 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) 4521 if (!DeducibleParams[I]) 4522 ++NumNonDeducible; 4523 4524 if (NumNonDeducible) { 4525 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 4526 << (NumNonDeducible > 1) 4527 << SourceRange(TemplateNameLoc, RAngleLoc); 4528 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 4529 if (!DeducibleParams[I]) { 4530 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 4531 if (Param->getDeclName()) 4532 Diag(Param->getLocation(), 4533 diag::note_partial_spec_unused_parameter) 4534 << Param->getDeclName(); 4535 else 4536 Diag(Param->getLocation(), 4537 diag::note_partial_spec_unused_parameter) 4538 << "<anonymous>"; 4539 } 4540 } 4541 } 4542 } else { 4543 // Create a new class template specialization declaration node for 4544 // this explicit specialization or friend declaration. 4545 Specialization 4546 = ClassTemplateSpecializationDecl::Create(Context, Kind, 4547 ClassTemplate->getDeclContext(), 4548 TemplateNameLoc, 4549 ClassTemplate, 4550 Converted.data(), 4551 Converted.size(), 4552 PrevDecl); 4553 SetNestedNameSpecifier(Specialization, SS); 4554 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 4555 Specialization->setTemplateParameterListsInfo(Context, 4556 NumMatchedTemplateParamLists, 4557 (TemplateParameterList**) TemplateParameterLists.release()); 4558 } 4559 4560 if (!PrevDecl) 4561 ClassTemplate->AddSpecialization(Specialization, InsertPos); 4562 4563 CanonType = Context.getTypeDeclType(Specialization); 4564 } 4565 4566 // C++ [temp.expl.spec]p6: 4567 // If a template, a member template or the member of a class template is 4568 // explicitly specialized then that specialization shall be declared 4569 // before the first use of that specialization that would cause an implicit 4570 // instantiation to take place, in every translation unit in which such a 4571 // use occurs; no diagnostic is required. 4572 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 4573 bool Okay = false; 4574 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 4575 // Is there any previous explicit specialization declaration? 4576 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 4577 Okay = true; 4578 break; 4579 } 4580 } 4581 4582 if (!Okay) { 4583 SourceRange Range(TemplateNameLoc, RAngleLoc); 4584 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 4585 << Context.getTypeDeclType(Specialization) << Range; 4586 4587 Diag(PrevDecl->getPointOfInstantiation(), 4588 diag::note_instantiation_required_here) 4589 << (PrevDecl->getTemplateSpecializationKind() 4590 != TSK_ImplicitInstantiation); 4591 return true; 4592 } 4593 } 4594 4595 // If this is not a friend, note that this is an explicit specialization. 4596 if (TUK != TUK_Friend) 4597 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 4598 4599 // Check that this isn't a redefinition of this specialization. 4600 if (TUK == TUK_Definition) { 4601 if (RecordDecl *Def = Specialization->getDefinition()) { 4602 SourceRange Range(TemplateNameLoc, RAngleLoc); 4603 Diag(TemplateNameLoc, diag::err_redefinition) 4604 << Context.getTypeDeclType(Specialization) << Range; 4605 Diag(Def->getLocation(), diag::note_previous_definition); 4606 Specialization->setInvalidDecl(); 4607 return true; 4608 } 4609 } 4610 4611 if (Attr) 4612 ProcessDeclAttributeList(S, Specialization, Attr); 4613 4614 // Build the fully-sugared type for this class template 4615 // specialization as the user wrote in the specialization 4616 // itself. This means that we'll pretty-print the type retrieved 4617 // from the specialization's declaration the way that the user 4618 // actually wrote the specialization, rather than formatting the 4619 // name based on the "canonical" representation used to store the 4620 // template arguments in the specialization. 4621 TypeSourceInfo *WrittenTy 4622 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 4623 TemplateArgs, CanonType); 4624 if (TUK != TUK_Friend) { 4625 Specialization->setTypeAsWritten(WrittenTy); 4626 if (TemplateParams) 4627 Specialization->setTemplateKeywordLoc(TemplateParams->getTemplateLoc()); 4628 } 4629 TemplateArgsIn.release(); 4630 4631 // C++ [temp.expl.spec]p9: 4632 // A template explicit specialization is in the scope of the 4633 // namespace in which the template was defined. 4634 // 4635 // We actually implement this paragraph where we set the semantic 4636 // context (in the creation of the ClassTemplateSpecializationDecl), 4637 // but we also maintain the lexical context where the actual 4638 // definition occurs. 4639 Specialization->setLexicalDeclContext(CurContext); 4640 4641 // We may be starting the definition of this specialization. 4642 if (TUK == TUK_Definition) 4643 Specialization->startDefinition(); 4644 4645 if (TUK == TUK_Friend) { 4646 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 4647 TemplateNameLoc, 4648 WrittenTy, 4649 /*FIXME:*/KWLoc); 4650 Friend->setAccess(AS_public); 4651 CurContext->addDecl(Friend); 4652 } else { 4653 // Add the specialization into its lexical context, so that it can 4654 // be seen when iterating through the list of declarations in that 4655 // context. However, specializations are not found by name lookup. 4656 CurContext->addDecl(Specialization); 4657 } 4658 return Specialization; 4659} 4660 4661Decl *Sema::ActOnTemplateDeclarator(Scope *S, 4662 MultiTemplateParamsArg TemplateParameterLists, 4663 Declarator &D) { 4664 return HandleDeclarator(S, D, move(TemplateParameterLists), false); 4665} 4666 4667Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope, 4668 MultiTemplateParamsArg TemplateParameterLists, 4669 Declarator &D) { 4670 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 4671 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 4672 4673 if (FTI.hasPrototype) { 4674 // FIXME: Diagnose arguments without names in C. 4675 } 4676 4677 Scope *ParentScope = FnBodyScope->getParent(); 4678 4679 Decl *DP = HandleDeclarator(ParentScope, D, 4680 move(TemplateParameterLists), 4681 /*IsFunctionDefinition=*/true); 4682 if (FunctionTemplateDecl *FunctionTemplate 4683 = dyn_cast_or_null<FunctionTemplateDecl>(DP)) 4684 return ActOnStartOfFunctionDef(FnBodyScope, 4685 FunctionTemplate->getTemplatedDecl()); 4686 if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(DP)) 4687 return ActOnStartOfFunctionDef(FnBodyScope, Function); 4688 return 0; 4689} 4690 4691/// \brief Strips various properties off an implicit instantiation 4692/// that has just been explicitly specialized. 4693static void StripImplicitInstantiation(NamedDecl *D) { 4694 D->dropAttrs(); 4695 4696 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4697 FD->setInlineSpecified(false); 4698 } 4699} 4700 4701/// \brief Diagnose cases where we have an explicit template specialization 4702/// before/after an explicit template instantiation, producing diagnostics 4703/// for those cases where they are required and determining whether the 4704/// new specialization/instantiation will have any effect. 4705/// 4706/// \param NewLoc the location of the new explicit specialization or 4707/// instantiation. 4708/// 4709/// \param NewTSK the kind of the new explicit specialization or instantiation. 4710/// 4711/// \param PrevDecl the previous declaration of the entity. 4712/// 4713/// \param PrevTSK the kind of the old explicit specialization or instantiatin. 4714/// 4715/// \param PrevPointOfInstantiation if valid, indicates where the previus 4716/// declaration was instantiated (either implicitly or explicitly). 4717/// 4718/// \param HasNoEffect will be set to true to indicate that the new 4719/// specialization or instantiation has no effect and should be ignored. 4720/// 4721/// \returns true if there was an error that should prevent the introduction of 4722/// the new declaration into the AST, false otherwise. 4723bool 4724Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc, 4725 TemplateSpecializationKind NewTSK, 4726 NamedDecl *PrevDecl, 4727 TemplateSpecializationKind PrevTSK, 4728 SourceLocation PrevPointOfInstantiation, 4729 bool &HasNoEffect) { 4730 HasNoEffect = false; 4731 4732 switch (NewTSK) { 4733 case TSK_Undeclared: 4734 case TSK_ImplicitInstantiation: 4735 assert(false && "Don't check implicit instantiations here"); 4736 return false; 4737 4738 case TSK_ExplicitSpecialization: 4739 switch (PrevTSK) { 4740 case TSK_Undeclared: 4741 case TSK_ExplicitSpecialization: 4742 // Okay, we're just specializing something that is either already 4743 // explicitly specialized or has merely been mentioned without any 4744 // instantiation. 4745 return false; 4746 4747 case TSK_ImplicitInstantiation: 4748 if (PrevPointOfInstantiation.isInvalid()) { 4749 // The declaration itself has not actually been instantiated, so it is 4750 // still okay to specialize it. 4751 StripImplicitInstantiation(PrevDecl); 4752 return false; 4753 } 4754 // Fall through 4755 4756 case TSK_ExplicitInstantiationDeclaration: 4757 case TSK_ExplicitInstantiationDefinition: 4758 assert((PrevTSK == TSK_ImplicitInstantiation || 4759 PrevPointOfInstantiation.isValid()) && 4760 "Explicit instantiation without point of instantiation?"); 4761 4762 // C++ [temp.expl.spec]p6: 4763 // If a template, a member template or the member of a class template 4764 // is explicitly specialized then that specialization shall be declared 4765 // before the first use of that specialization that would cause an 4766 // implicit instantiation to take place, in every translation unit in 4767 // which such a use occurs; no diagnostic is required. 4768 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 4769 // Is there any previous explicit specialization declaration? 4770 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) 4771 return false; 4772 } 4773 4774 Diag(NewLoc, diag::err_specialization_after_instantiation) 4775 << PrevDecl; 4776 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here) 4777 << (PrevTSK != TSK_ImplicitInstantiation); 4778 4779 return true; 4780 } 4781 break; 4782 4783 case TSK_ExplicitInstantiationDeclaration: 4784 switch (PrevTSK) { 4785 case TSK_ExplicitInstantiationDeclaration: 4786 // This explicit instantiation declaration is redundant (that's okay). 4787 HasNoEffect = true; 4788 return false; 4789 4790 case TSK_Undeclared: 4791 case TSK_ImplicitInstantiation: 4792 // We're explicitly instantiating something that may have already been 4793 // implicitly instantiated; that's fine. 4794 return false; 4795 4796 case TSK_ExplicitSpecialization: 4797 // C++0x [temp.explicit]p4: 4798 // For a given set of template parameters, if an explicit instantiation 4799 // of a template appears after a declaration of an explicit 4800 // specialization for that template, the explicit instantiation has no 4801 // effect. 4802 HasNoEffect = true; 4803 return false; 4804 4805 case TSK_ExplicitInstantiationDefinition: 4806 // C++0x [temp.explicit]p10: 4807 // If an entity is the subject of both an explicit instantiation 4808 // declaration and an explicit instantiation definition in the same 4809 // translation unit, the definition shall follow the declaration. 4810 Diag(NewLoc, 4811 diag::err_explicit_instantiation_declaration_after_definition); 4812 Diag(PrevPointOfInstantiation, 4813 diag::note_explicit_instantiation_definition_here); 4814 assert(PrevPointOfInstantiation.isValid() && 4815 "Explicit instantiation without point of instantiation?"); 4816 HasNoEffect = true; 4817 return false; 4818 } 4819 break; 4820 4821 case TSK_ExplicitInstantiationDefinition: 4822 switch (PrevTSK) { 4823 case TSK_Undeclared: 4824 case TSK_ImplicitInstantiation: 4825 // We're explicitly instantiating something that may have already been 4826 // implicitly instantiated; that's fine. 4827 return false; 4828 4829 case TSK_ExplicitSpecialization: 4830 // C++ DR 259, C++0x [temp.explicit]p4: 4831 // For a given set of template parameters, if an explicit 4832 // instantiation of a template appears after a declaration of 4833 // an explicit specialization for that template, the explicit 4834 // instantiation has no effect. 4835 // 4836 // In C++98/03 mode, we only give an extension warning here, because it 4837 // is not harmful to try to explicitly instantiate something that 4838 // has been explicitly specialized. 4839 if (!getLangOptions().CPlusPlus0x) { 4840 Diag(NewLoc, diag::ext_explicit_instantiation_after_specialization) 4841 << PrevDecl; 4842 Diag(PrevDecl->getLocation(), 4843 diag::note_previous_template_specialization); 4844 } 4845 HasNoEffect = true; 4846 return false; 4847 4848 case TSK_ExplicitInstantiationDeclaration: 4849 // We're explicity instantiating a definition for something for which we 4850 // were previously asked to suppress instantiations. That's fine. 4851 return false; 4852 4853 case TSK_ExplicitInstantiationDefinition: 4854 // C++0x [temp.spec]p5: 4855 // For a given template and a given set of template-arguments, 4856 // - an explicit instantiation definition shall appear at most once 4857 // in a program, 4858 Diag(NewLoc, diag::err_explicit_instantiation_duplicate) 4859 << PrevDecl; 4860 Diag(PrevPointOfInstantiation, 4861 diag::note_previous_explicit_instantiation); 4862 HasNoEffect = true; 4863 return false; 4864 } 4865 break; 4866 } 4867 4868 assert(false && "Missing specialization/instantiation case?"); 4869 4870 return false; 4871} 4872 4873/// \brief Perform semantic analysis for the given dependent function 4874/// template specialization. The only possible way to get a dependent 4875/// function template specialization is with a friend declaration, 4876/// like so: 4877/// 4878/// template <class T> void foo(T); 4879/// template <class T> class A { 4880/// friend void foo<>(T); 4881/// }; 4882/// 4883/// There really isn't any useful analysis we can do here, so we 4884/// just store the information. 4885bool 4886Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD, 4887 const TemplateArgumentListInfo &ExplicitTemplateArgs, 4888 LookupResult &Previous) { 4889 // Remove anything from Previous that isn't a function template in 4890 // the correct context. 4891 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4892 LookupResult::Filter F = Previous.makeFilter(); 4893 while (F.hasNext()) { 4894 NamedDecl *D = F.next()->getUnderlyingDecl(); 4895 if (!isa<FunctionTemplateDecl>(D) || 4896 !FDLookupContext->InEnclosingNamespaceSetOf( 4897 D->getDeclContext()->getRedeclContext())) 4898 F.erase(); 4899 } 4900 F.done(); 4901 4902 // Should this be diagnosed here? 4903 if (Previous.empty()) return true; 4904 4905 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(), 4906 ExplicitTemplateArgs); 4907 return false; 4908} 4909 4910/// \brief Perform semantic analysis for the given function template 4911/// specialization. 4912/// 4913/// This routine performs all of the semantic analysis required for an 4914/// explicit function template specialization. On successful completion, 4915/// the function declaration \p FD will become a function template 4916/// specialization. 4917/// 4918/// \param FD the function declaration, which will be updated to become a 4919/// function template specialization. 4920/// 4921/// \param ExplicitTemplateArgs the explicitly-provided template arguments, 4922/// if any. Note that this may be valid info even when 0 arguments are 4923/// explicitly provided as in, e.g., \c void sort<>(char*, char*); 4924/// as it anyway contains info on the angle brackets locations. 4925/// 4926/// \param PrevDecl the set of declarations that may be specialized by 4927/// this function specialization. 4928bool 4929Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD, 4930 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4931 LookupResult &Previous) { 4932 // The set of function template specializations that could match this 4933 // explicit function template specialization. 4934 UnresolvedSet<8> Candidates; 4935 4936 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4937 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 4938 I != E; ++I) { 4939 NamedDecl *Ovl = (*I)->getUnderlyingDecl(); 4940 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) { 4941 // Only consider templates found within the same semantic lookup scope as 4942 // FD. 4943 if (!FDLookupContext->InEnclosingNamespaceSetOf( 4944 Ovl->getDeclContext()->getRedeclContext())) 4945 continue; 4946 4947 // C++ [temp.expl.spec]p11: 4948 // A trailing template-argument can be left unspecified in the 4949 // template-id naming an explicit function template specialization 4950 // provided it can be deduced from the function argument type. 4951 // Perform template argument deduction to determine whether we may be 4952 // specializing this template. 4953 // FIXME: It is somewhat wasteful to build 4954 TemplateDeductionInfo Info(Context, FD->getLocation()); 4955 FunctionDecl *Specialization = 0; 4956 if (TemplateDeductionResult TDK 4957 = DeduceTemplateArguments(FunTmpl, ExplicitTemplateArgs, 4958 FD->getType(), 4959 Specialization, 4960 Info)) { 4961 // FIXME: Template argument deduction failed; record why it failed, so 4962 // that we can provide nifty diagnostics. 4963 (void)TDK; 4964 continue; 4965 } 4966 4967 // Record this candidate. 4968 Candidates.addDecl(Specialization, I.getAccess()); 4969 } 4970 } 4971 4972 // Find the most specialized function template. 4973 UnresolvedSetIterator Result 4974 = getMostSpecialized(Candidates.begin(), Candidates.end(), 4975 TPOC_Other, 0, FD->getLocation(), 4976 PDiag(diag::err_function_template_spec_no_match) 4977 << FD->getDeclName(), 4978 PDiag(diag::err_function_template_spec_ambiguous) 4979 << FD->getDeclName() << (ExplicitTemplateArgs != 0), 4980 PDiag(diag::note_function_template_spec_matched)); 4981 if (Result == Candidates.end()) 4982 return true; 4983 4984 // Ignore access information; it doesn't figure into redeclaration checking. 4985 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 4986 Specialization->setLocation(FD->getLocation()); 4987 4988 // FIXME: Check if the prior specialization has a point of instantiation. 4989 // If so, we have run afoul of . 4990 4991 // If this is a friend declaration, then we're not really declaring 4992 // an explicit specialization. 4993 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None); 4994 4995 // Check the scope of this explicit specialization. 4996 if (!isFriend && 4997 CheckTemplateSpecializationScope(*this, 4998 Specialization->getPrimaryTemplate(), 4999 Specialization, FD->getLocation(), 5000 false)) 5001 return true; 5002 5003 // C++ [temp.expl.spec]p6: 5004 // If a template, a member template or the member of a class template is 5005 // explicitly specialized then that specialization shall be declared 5006 // before the first use of that specialization that would cause an implicit 5007 // instantiation to take place, in every translation unit in which such a 5008 // use occurs; no diagnostic is required. 5009 FunctionTemplateSpecializationInfo *SpecInfo 5010 = Specialization->getTemplateSpecializationInfo(); 5011 assert(SpecInfo && "Function template specialization info missing?"); 5012 5013 bool HasNoEffect = false; 5014 if (!isFriend && 5015 CheckSpecializationInstantiationRedecl(FD->getLocation(), 5016 TSK_ExplicitSpecialization, 5017 Specialization, 5018 SpecInfo->getTemplateSpecializationKind(), 5019 SpecInfo->getPointOfInstantiation(), 5020 HasNoEffect)) 5021 return true; 5022 5023 // Mark the prior declaration as an explicit specialization, so that later 5024 // clients know that this is an explicit specialization. 5025 if (!isFriend) { 5026 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization); 5027 MarkUnusedFileScopedDecl(Specialization); 5028 } 5029 5030 // Turn the given function declaration into a function template 5031 // specialization, with the template arguments from the previous 5032 // specialization. 5033 // Take copies of (semantic and syntactic) template argument lists. 5034 const TemplateArgumentList* TemplArgs = new (Context) 5035 TemplateArgumentList(Specialization->getTemplateSpecializationArgs()); 5036 const TemplateArgumentListInfo* TemplArgsAsWritten = ExplicitTemplateArgs 5037 ? new (Context) TemplateArgumentListInfo(*ExplicitTemplateArgs) : 0; 5038 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(), 5039 TemplArgs, /*InsertPos=*/0, 5040 SpecInfo->getTemplateSpecializationKind(), 5041 TemplArgsAsWritten); 5042 5043 // The "previous declaration" for this function template specialization is 5044 // the prior function template specialization. 5045 Previous.clear(); 5046 Previous.addDecl(Specialization); 5047 return false; 5048} 5049 5050/// \brief Perform semantic analysis for the given non-template member 5051/// specialization. 5052/// 5053/// This routine performs all of the semantic analysis required for an 5054/// explicit member function specialization. On successful completion, 5055/// the function declaration \p FD will become a member function 5056/// specialization. 5057/// 5058/// \param Member the member declaration, which will be updated to become a 5059/// specialization. 5060/// 5061/// \param Previous the set of declarations, one of which may be specialized 5062/// by this function specialization; the set will be modified to contain the 5063/// redeclared member. 5064bool 5065Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) { 5066 assert(!isa<TemplateDecl>(Member) && "Only for non-template members"); 5067 5068 // Try to find the member we are instantiating. 5069 NamedDecl *Instantiation = 0; 5070 NamedDecl *InstantiatedFrom = 0; 5071 MemberSpecializationInfo *MSInfo = 0; 5072 5073 if (Previous.empty()) { 5074 // Nowhere to look anyway. 5075 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) { 5076 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 5077 I != E; ++I) { 5078 NamedDecl *D = (*I)->getUnderlyingDecl(); 5079 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 5080 if (Context.hasSameType(Function->getType(), Method->getType())) { 5081 Instantiation = Method; 5082 InstantiatedFrom = Method->getInstantiatedFromMemberFunction(); 5083 MSInfo = Method->getMemberSpecializationInfo(); 5084 break; 5085 } 5086 } 5087 } 5088 } else if (isa<VarDecl>(Member)) { 5089 VarDecl *PrevVar; 5090 if (Previous.isSingleResult() && 5091 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl()))) 5092 if (PrevVar->isStaticDataMember()) { 5093 Instantiation = PrevVar; 5094 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember(); 5095 MSInfo = PrevVar->getMemberSpecializationInfo(); 5096 } 5097 } else if (isa<RecordDecl>(Member)) { 5098 CXXRecordDecl *PrevRecord; 5099 if (Previous.isSingleResult() && 5100 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) { 5101 Instantiation = PrevRecord; 5102 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass(); 5103 MSInfo = PrevRecord->getMemberSpecializationInfo(); 5104 } 5105 } 5106 5107 if (!Instantiation) { 5108 // There is no previous declaration that matches. Since member 5109 // specializations are always out-of-line, the caller will complain about 5110 // this mismatch later. 5111 return false; 5112 } 5113 5114 // If this is a friend, just bail out here before we start turning 5115 // things into explicit specializations. 5116 if (Member->getFriendObjectKind() != Decl::FOK_None) { 5117 // Preserve instantiation information. 5118 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) { 5119 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction( 5120 cast<CXXMethodDecl>(InstantiatedFrom), 5121 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind()); 5122 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) { 5123 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 5124 cast<CXXRecordDecl>(InstantiatedFrom), 5125 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind()); 5126 } 5127 5128 Previous.clear(); 5129 Previous.addDecl(Instantiation); 5130 return false; 5131 } 5132 5133 // Make sure that this is a specialization of a member. 5134 if (!InstantiatedFrom) { 5135 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated) 5136 << Member; 5137 Diag(Instantiation->getLocation(), diag::note_specialized_decl); 5138 return true; 5139 } 5140 5141 // C++ [temp.expl.spec]p6: 5142 // If a template, a member template or the member of a class template is 5143 // explicitly specialized then that spe- cialization shall be declared 5144 // before the first use of that specialization that would cause an implicit 5145 // instantiation to take place, in every translation unit in which such a 5146 // use occurs; no diagnostic is required. 5147 assert(MSInfo && "Member specialization info missing?"); 5148 5149 bool HasNoEffect = false; 5150 if (CheckSpecializationInstantiationRedecl(Member->getLocation(), 5151 TSK_ExplicitSpecialization, 5152 Instantiation, 5153 MSInfo->getTemplateSpecializationKind(), 5154 MSInfo->getPointOfInstantiation(), 5155 HasNoEffect)) 5156 return true; 5157 5158 // Check the scope of this explicit specialization. 5159 if (CheckTemplateSpecializationScope(*this, 5160 InstantiatedFrom, 5161 Instantiation, Member->getLocation(), 5162 false)) 5163 return true; 5164 5165 // Note that this is an explicit instantiation of a member. 5166 // the original declaration to note that it is an explicit specialization 5167 // (if it was previously an implicit instantiation). This latter step 5168 // makes bookkeeping easier. 5169 if (isa<FunctionDecl>(Member)) { 5170 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation); 5171 if (InstantiationFunction->getTemplateSpecializationKind() == 5172 TSK_ImplicitInstantiation) { 5173 InstantiationFunction->setTemplateSpecializationKind( 5174 TSK_ExplicitSpecialization); 5175 InstantiationFunction->setLocation(Member->getLocation()); 5176 } 5177 5178 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction( 5179 cast<CXXMethodDecl>(InstantiatedFrom), 5180 TSK_ExplicitSpecialization); 5181 MarkUnusedFileScopedDecl(InstantiationFunction); 5182 } else if (isa<VarDecl>(Member)) { 5183 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation); 5184 if (InstantiationVar->getTemplateSpecializationKind() == 5185 TSK_ImplicitInstantiation) { 5186 InstantiationVar->setTemplateSpecializationKind( 5187 TSK_ExplicitSpecialization); 5188 InstantiationVar->setLocation(Member->getLocation()); 5189 } 5190 5191 Context.setInstantiatedFromStaticDataMember(cast<VarDecl>(Member), 5192 cast<VarDecl>(InstantiatedFrom), 5193 TSK_ExplicitSpecialization); 5194 MarkUnusedFileScopedDecl(InstantiationVar); 5195 } else { 5196 assert(isa<CXXRecordDecl>(Member) && "Only member classes remain"); 5197 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation); 5198 if (InstantiationClass->getTemplateSpecializationKind() == 5199 TSK_ImplicitInstantiation) { 5200 InstantiationClass->setTemplateSpecializationKind( 5201 TSK_ExplicitSpecialization); 5202 InstantiationClass->setLocation(Member->getLocation()); 5203 } 5204 5205 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 5206 cast<CXXRecordDecl>(InstantiatedFrom), 5207 TSK_ExplicitSpecialization); 5208 } 5209 5210 // Save the caller the trouble of having to figure out which declaration 5211 // this specialization matches. 5212 Previous.clear(); 5213 Previous.addDecl(Instantiation); 5214 return false; 5215} 5216 5217/// \brief Check the scope of an explicit instantiation. 5218/// 5219/// \returns true if a serious error occurs, false otherwise. 5220static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D, 5221 SourceLocation InstLoc, 5222 bool WasQualifiedName) { 5223 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext(); 5224 DeclContext *CurContext = S.CurContext->getRedeclContext(); 5225 5226 if (CurContext->isRecord()) { 5227 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class) 5228 << D; 5229 return true; 5230 } 5231 5232 // C++0x [temp.explicit]p2: 5233 // An explicit instantiation shall appear in an enclosing namespace of its 5234 // template. 5235 // 5236 // This is DR275, which we do not retroactively apply to C++98/03. 5237 if (S.getLangOptions().CPlusPlus0x && 5238 !CurContext->Encloses(OrigContext)) { 5239 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) 5240 S.Diag(InstLoc, 5241 S.getLangOptions().CPlusPlus0x? 5242 diag::err_explicit_instantiation_out_of_scope 5243 : diag::warn_explicit_instantiation_out_of_scope_0x) 5244 << D << NS; 5245 else 5246 S.Diag(InstLoc, 5247 S.getLangOptions().CPlusPlus0x? 5248 diag::err_explicit_instantiation_must_be_global 5249 : diag::warn_explicit_instantiation_out_of_scope_0x) 5250 << D; 5251 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 5252 return false; 5253 } 5254 5255 // C++0x [temp.explicit]p2: 5256 // If the name declared in the explicit instantiation is an unqualified 5257 // name, the explicit instantiation shall appear in the namespace where 5258 // its template is declared or, if that namespace is inline (7.3.1), any 5259 // namespace from its enclosing namespace set. 5260 if (WasQualifiedName) 5261 return false; 5262 5263 if (CurContext->InEnclosingNamespaceSetOf(OrigContext)) 5264 return false; 5265 5266 S.Diag(InstLoc, 5267 S.getLangOptions().CPlusPlus0x? 5268 diag::err_explicit_instantiation_unqualified_wrong_namespace 5269 : diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x) 5270 << D << OrigContext; 5271 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 5272 return false; 5273} 5274 5275/// \brief Determine whether the given scope specifier has a template-id in it. 5276static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) { 5277 if (!SS.isSet()) 5278 return false; 5279 5280 // C++0x [temp.explicit]p2: 5281 // If the explicit instantiation is for a member function, a member class 5282 // or a static data member of a class template specialization, the name of 5283 // the class template specialization in the qualified-id for the member 5284 // name shall be a simple-template-id. 5285 // 5286 // C++98 has the same restriction, just worded differently. 5287 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 5288 NNS; NNS = NNS->getPrefix()) 5289 if (const Type *T = NNS->getAsType()) 5290 if (isa<TemplateSpecializationType>(T)) 5291 return true; 5292 5293 return false; 5294} 5295 5296// Explicit instantiation of a class template specialization 5297DeclResult 5298Sema::ActOnExplicitInstantiation(Scope *S, 5299 SourceLocation ExternLoc, 5300 SourceLocation TemplateLoc, 5301 unsigned TagSpec, 5302 SourceLocation KWLoc, 5303 const CXXScopeSpec &SS, 5304 TemplateTy TemplateD, 5305 SourceLocation TemplateNameLoc, 5306 SourceLocation LAngleLoc, 5307 ASTTemplateArgsPtr TemplateArgsIn, 5308 SourceLocation RAngleLoc, 5309 AttributeList *Attr) { 5310 // Find the class template we're specializing 5311 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 5312 ClassTemplateDecl *ClassTemplate 5313 = cast<ClassTemplateDecl>(Name.getAsTemplateDecl()); 5314 5315 // Check that the specialization uses the same tag kind as the 5316 // original template. 5317 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 5318 assert(Kind != TTK_Enum && 5319 "Invalid enum tag in class template explicit instantiation!"); 5320 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 5321 Kind, KWLoc, 5322 *ClassTemplate->getIdentifier())) { 5323 Diag(KWLoc, diag::err_use_with_wrong_tag) 5324 << ClassTemplate 5325 << FixItHint::CreateReplacement(KWLoc, 5326 ClassTemplate->getTemplatedDecl()->getKindName()); 5327 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 5328 diag::note_previous_use); 5329 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 5330 } 5331 5332 // C++0x [temp.explicit]p2: 5333 // There are two forms of explicit instantiation: an explicit instantiation 5334 // definition and an explicit instantiation declaration. An explicit 5335 // instantiation declaration begins with the extern keyword. [...] 5336 TemplateSpecializationKind TSK 5337 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 5338 : TSK_ExplicitInstantiationDeclaration; 5339 5340 // Translate the parser's template argument list in our AST format. 5341 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 5342 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 5343 5344 // Check that the template argument list is well-formed for this 5345 // template. 5346 llvm::SmallVector<TemplateArgument, 4> Converted; 5347 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 5348 TemplateArgs, false, Converted)) 5349 return true; 5350 5351 assert((Converted.size() == ClassTemplate->getTemplateParameters()->size()) && 5352 "Converted template argument list is too short!"); 5353 5354 // Find the class template specialization declaration that 5355 // corresponds to these arguments. 5356 void *InsertPos = 0; 5357 ClassTemplateSpecializationDecl *PrevDecl 5358 = ClassTemplate->findSpecialization(Converted.data(), 5359 Converted.size(), InsertPos); 5360 5361 TemplateSpecializationKind PrevDecl_TSK 5362 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared; 5363 5364 // C++0x [temp.explicit]p2: 5365 // [...] An explicit instantiation shall appear in an enclosing 5366 // namespace of its template. [...] 5367 // 5368 // This is C++ DR 275. 5369 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc, 5370 SS.isSet())) 5371 return true; 5372 5373 ClassTemplateSpecializationDecl *Specialization = 0; 5374 5375 bool HasNoEffect = false; 5376 if (PrevDecl) { 5377 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK, 5378 PrevDecl, PrevDecl_TSK, 5379 PrevDecl->getPointOfInstantiation(), 5380 HasNoEffect)) 5381 return PrevDecl; 5382 5383 // Even though HasNoEffect == true means that this explicit instantiation 5384 // has no effect on semantics, we go on to put its syntax in the AST. 5385 5386 if (PrevDecl_TSK == TSK_ImplicitInstantiation || 5387 PrevDecl_TSK == TSK_Undeclared) { 5388 // Since the only prior class template specialization with these 5389 // arguments was referenced but not declared, reuse that 5390 // declaration node as our own, updating the source location 5391 // for the template name to reflect our new declaration. 5392 // (Other source locations will be updated later.) 5393 Specialization = PrevDecl; 5394 Specialization->setLocation(TemplateNameLoc); 5395 PrevDecl = 0; 5396 } 5397 } 5398 5399 if (!Specialization) { 5400 // Create a new class template specialization declaration node for 5401 // this explicit specialization. 5402 Specialization 5403 = ClassTemplateSpecializationDecl::Create(Context, Kind, 5404 ClassTemplate->getDeclContext(), 5405 TemplateNameLoc, 5406 ClassTemplate, 5407 Converted.data(), 5408 Converted.size(), 5409 PrevDecl); 5410 SetNestedNameSpecifier(Specialization, SS); 5411 5412 if (!HasNoEffect && !PrevDecl) { 5413 // Insert the new specialization. 5414 ClassTemplate->AddSpecialization(Specialization, InsertPos); 5415 } 5416 } 5417 5418 // Build the fully-sugared type for this explicit instantiation as 5419 // the user wrote in the explicit instantiation itself. This means 5420 // that we'll pretty-print the type retrieved from the 5421 // specialization's declaration the way that the user actually wrote 5422 // the explicit instantiation, rather than formatting the name based 5423 // on the "canonical" representation used to store the template 5424 // arguments in the specialization. 5425 TypeSourceInfo *WrittenTy 5426 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 5427 TemplateArgs, 5428 Context.getTypeDeclType(Specialization)); 5429 Specialization->setTypeAsWritten(WrittenTy); 5430 TemplateArgsIn.release(); 5431 5432 // Set source locations for keywords. 5433 Specialization->setExternLoc(ExternLoc); 5434 Specialization->setTemplateKeywordLoc(TemplateLoc); 5435 5436 // Add the explicit instantiation into its lexical context. However, 5437 // since explicit instantiations are never found by name lookup, we 5438 // just put it into the declaration context directly. 5439 Specialization->setLexicalDeclContext(CurContext); 5440 CurContext->addDecl(Specialization); 5441 5442 // Syntax is now OK, so return if it has no other effect on semantics. 5443 if (HasNoEffect) { 5444 // Set the template specialization kind. 5445 Specialization->setTemplateSpecializationKind(TSK); 5446 return Specialization; 5447 } 5448 5449 // C++ [temp.explicit]p3: 5450 // A definition of a class template or class member template 5451 // shall be in scope at the point of the explicit instantiation of 5452 // the class template or class member template. 5453 // 5454 // This check comes when we actually try to perform the 5455 // instantiation. 5456 ClassTemplateSpecializationDecl *Def 5457 = cast_or_null<ClassTemplateSpecializationDecl>( 5458 Specialization->getDefinition()); 5459 if (!Def) 5460 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK); 5461 else if (TSK == TSK_ExplicitInstantiationDefinition) { 5462 MarkVTableUsed(TemplateNameLoc, Specialization, true); 5463 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation()); 5464 } 5465 5466 // Instantiate the members of this class template specialization. 5467 Def = cast_or_null<ClassTemplateSpecializationDecl>( 5468 Specialization->getDefinition()); 5469 if (Def) { 5470 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind(); 5471 5472 // Fix a TSK_ExplicitInstantiationDeclaration followed by a 5473 // TSK_ExplicitInstantiationDefinition 5474 if (Old_TSK == TSK_ExplicitInstantiationDeclaration && 5475 TSK == TSK_ExplicitInstantiationDefinition) 5476 Def->setTemplateSpecializationKind(TSK); 5477 5478 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK); 5479 } 5480 5481 // Set the template specialization kind. 5482 Specialization->setTemplateSpecializationKind(TSK); 5483 return Specialization; 5484} 5485 5486// Explicit instantiation of a member class of a class template. 5487DeclResult 5488Sema::ActOnExplicitInstantiation(Scope *S, 5489 SourceLocation ExternLoc, 5490 SourceLocation TemplateLoc, 5491 unsigned TagSpec, 5492 SourceLocation KWLoc, 5493 CXXScopeSpec &SS, 5494 IdentifierInfo *Name, 5495 SourceLocation NameLoc, 5496 AttributeList *Attr) { 5497 5498 bool Owned = false; 5499 bool IsDependent = false; 5500 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference, 5501 KWLoc, SS, Name, NameLoc, Attr, AS_none, 5502 MultiTemplateParamsArg(*this, 0, 0), 5503 Owned, IsDependent, false, false, 5504 TypeResult()); 5505 assert(!IsDependent && "explicit instantiation of dependent name not yet handled"); 5506 5507 if (!TagD) 5508 return true; 5509 5510 TagDecl *Tag = cast<TagDecl>(TagD); 5511 if (Tag->isEnum()) { 5512 Diag(TemplateLoc, diag::err_explicit_instantiation_enum) 5513 << Context.getTypeDeclType(Tag); 5514 return true; 5515 } 5516 5517 if (Tag->isInvalidDecl()) 5518 return true; 5519 5520 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag); 5521 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass(); 5522 if (!Pattern) { 5523 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type) 5524 << Context.getTypeDeclType(Record); 5525 Diag(Record->getLocation(), diag::note_nontemplate_decl_here); 5526 return true; 5527 } 5528 5529 // C++0x [temp.explicit]p2: 5530 // If the explicit instantiation is for a class or member class, the 5531 // elaborated-type-specifier in the declaration shall include a 5532 // simple-template-id. 5533 // 5534 // C++98 has the same restriction, just worded differently. 5535 if (!ScopeSpecifierHasTemplateId(SS)) 5536 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id) 5537 << Record << SS.getRange(); 5538 5539 // C++0x [temp.explicit]p2: 5540 // There are two forms of explicit instantiation: an explicit instantiation 5541 // definition and an explicit instantiation declaration. An explicit 5542 // instantiation declaration begins with the extern keyword. [...] 5543 TemplateSpecializationKind TSK 5544 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 5545 : TSK_ExplicitInstantiationDeclaration; 5546 5547 // C++0x [temp.explicit]p2: 5548 // [...] An explicit instantiation shall appear in an enclosing 5549 // namespace of its template. [...] 5550 // 5551 // This is C++ DR 275. 5552 CheckExplicitInstantiationScope(*this, Record, NameLoc, true); 5553 5554 // Verify that it is okay to explicitly instantiate here. 5555 CXXRecordDecl *PrevDecl 5556 = cast_or_null<CXXRecordDecl>(Record->getPreviousDeclaration()); 5557 if (!PrevDecl && Record->getDefinition()) 5558 PrevDecl = Record; 5559 if (PrevDecl) { 5560 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo(); 5561 bool HasNoEffect = false; 5562 assert(MSInfo && "No member specialization information?"); 5563 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK, 5564 PrevDecl, 5565 MSInfo->getTemplateSpecializationKind(), 5566 MSInfo->getPointOfInstantiation(), 5567 HasNoEffect)) 5568 return true; 5569 if (HasNoEffect) 5570 return TagD; 5571 } 5572 5573 CXXRecordDecl *RecordDef 5574 = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 5575 if (!RecordDef) { 5576 // C++ [temp.explicit]p3: 5577 // A definition of a member class of a class template shall be in scope 5578 // at the point of an explicit instantiation of the member class. 5579 CXXRecordDecl *Def 5580 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition()); 5581 if (!Def) { 5582 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member) 5583 << 0 << Record->getDeclName() << Record->getDeclContext(); 5584 Diag(Pattern->getLocation(), diag::note_forward_declaration) 5585 << Pattern; 5586 return true; 5587 } else { 5588 if (InstantiateClass(NameLoc, Record, Def, 5589 getTemplateInstantiationArgs(Record), 5590 TSK)) 5591 return true; 5592 5593 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 5594 if (!RecordDef) 5595 return true; 5596 } 5597 } 5598 5599 // Instantiate all of the members of the class. 5600 InstantiateClassMembers(NameLoc, RecordDef, 5601 getTemplateInstantiationArgs(Record), TSK); 5602 5603 if (TSK == TSK_ExplicitInstantiationDefinition) 5604 MarkVTableUsed(NameLoc, RecordDef, true); 5605 5606 // FIXME: We don't have any representation for explicit instantiations of 5607 // member classes. Such a representation is not needed for compilation, but it 5608 // should be available for clients that want to see all of the declarations in 5609 // the source code. 5610 return TagD; 5611} 5612 5613DeclResult Sema::ActOnExplicitInstantiation(Scope *S, 5614 SourceLocation ExternLoc, 5615 SourceLocation TemplateLoc, 5616 Declarator &D) { 5617 // Explicit instantiations always require a name. 5618 // TODO: check if/when DNInfo should replace Name. 5619 DeclarationNameInfo NameInfo = GetNameForDeclarator(D); 5620 DeclarationName Name = NameInfo.getName(); 5621 if (!Name) { 5622 if (!D.isInvalidType()) 5623 Diag(D.getDeclSpec().getSourceRange().getBegin(), 5624 diag::err_explicit_instantiation_requires_name) 5625 << D.getDeclSpec().getSourceRange() 5626 << D.getSourceRange(); 5627 5628 return true; 5629 } 5630 5631 // The scope passed in may not be a decl scope. Zip up the scope tree until 5632 // we find one that is. 5633 while ((S->getFlags() & Scope::DeclScope) == 0 || 5634 (S->getFlags() & Scope::TemplateParamScope) != 0) 5635 S = S->getParent(); 5636 5637 // Determine the type of the declaration. 5638 TypeSourceInfo *T = GetTypeForDeclarator(D, S); 5639 QualType R = T->getType(); 5640 if (R.isNull()) 5641 return true; 5642 5643 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 5644 // Cannot explicitly instantiate a typedef. 5645 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef) 5646 << Name; 5647 return true; 5648 } 5649 5650 // C++0x [temp.explicit]p1: 5651 // [...] An explicit instantiation of a function template shall not use the 5652 // inline or constexpr specifiers. 5653 // Presumably, this also applies to member functions of class templates as 5654 // well. 5655 if (D.getDeclSpec().isInlineSpecified() && getLangOptions().CPlusPlus0x) 5656 Diag(D.getDeclSpec().getInlineSpecLoc(), 5657 diag::err_explicit_instantiation_inline) 5658 <<FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); 5659 5660 // FIXME: check for constexpr specifier. 5661 5662 // C++0x [temp.explicit]p2: 5663 // There are two forms of explicit instantiation: an explicit instantiation 5664 // definition and an explicit instantiation declaration. An explicit 5665 // instantiation declaration begins with the extern keyword. [...] 5666 TemplateSpecializationKind TSK 5667 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 5668 : TSK_ExplicitInstantiationDeclaration; 5669 5670 LookupResult Previous(*this, NameInfo, LookupOrdinaryName); 5671 LookupParsedName(Previous, S, &D.getCXXScopeSpec()); 5672 5673 if (!R->isFunctionType()) { 5674 // C++ [temp.explicit]p1: 5675 // A [...] static data member of a class template can be explicitly 5676 // instantiated from the member definition associated with its class 5677 // template. 5678 if (Previous.isAmbiguous()) 5679 return true; 5680 5681 VarDecl *Prev = Previous.getAsSingle<VarDecl>(); 5682 if (!Prev || !Prev->isStaticDataMember()) { 5683 // We expect to see a data data member here. 5684 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known) 5685 << Name; 5686 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5687 P != PEnd; ++P) 5688 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here); 5689 return true; 5690 } 5691 5692 if (!Prev->getInstantiatedFromStaticDataMember()) { 5693 // FIXME: Check for explicit specialization? 5694 Diag(D.getIdentifierLoc(), 5695 diag::err_explicit_instantiation_data_member_not_instantiated) 5696 << Prev; 5697 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here); 5698 // FIXME: Can we provide a note showing where this was declared? 5699 return true; 5700 } 5701 5702 // C++0x [temp.explicit]p2: 5703 // If the explicit instantiation is for a member function, a member class 5704 // or a static data member of a class template specialization, the name of 5705 // the class template specialization in the qualified-id for the member 5706 // name shall be a simple-template-id. 5707 // 5708 // C++98 has the same restriction, just worded differently. 5709 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5710 Diag(D.getIdentifierLoc(), 5711 diag::ext_explicit_instantiation_without_qualified_id) 5712 << Prev << D.getCXXScopeSpec().getRange(); 5713 5714 // Check the scope of this explicit instantiation. 5715 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true); 5716 5717 // Verify that it is okay to explicitly instantiate here. 5718 MemberSpecializationInfo *MSInfo = Prev->getMemberSpecializationInfo(); 5719 assert(MSInfo && "Missing static data member specialization info?"); 5720 bool HasNoEffect = false; 5721 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev, 5722 MSInfo->getTemplateSpecializationKind(), 5723 MSInfo->getPointOfInstantiation(), 5724 HasNoEffect)) 5725 return true; 5726 if (HasNoEffect) 5727 return (Decl*) 0; 5728 5729 // Instantiate static data member. 5730 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5731 if (TSK == TSK_ExplicitInstantiationDefinition) 5732 InstantiateStaticDataMemberDefinition(D.getIdentifierLoc(), Prev); 5733 5734 // FIXME: Create an ExplicitInstantiation node? 5735 return (Decl*) 0; 5736 } 5737 5738 // If the declarator is a template-id, translate the parser's template 5739 // argument list into our AST format. 5740 bool HasExplicitTemplateArgs = false; 5741 TemplateArgumentListInfo TemplateArgs; 5742 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 5743 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 5744 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); 5745 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); 5746 ASTTemplateArgsPtr TemplateArgsPtr(*this, 5747 TemplateId->getTemplateArgs(), 5748 TemplateId->NumArgs); 5749 translateTemplateArguments(TemplateArgsPtr, TemplateArgs); 5750 HasExplicitTemplateArgs = true; 5751 TemplateArgsPtr.release(); 5752 } 5753 5754 // C++ [temp.explicit]p1: 5755 // A [...] function [...] can be explicitly instantiated from its template. 5756 // A member function [...] of a class template can be explicitly 5757 // instantiated from the member definition associated with its class 5758 // template. 5759 UnresolvedSet<8> Matches; 5760 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5761 P != PEnd; ++P) { 5762 NamedDecl *Prev = *P; 5763 if (!HasExplicitTemplateArgs) { 5764 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) { 5765 if (Context.hasSameUnqualifiedType(Method->getType(), R)) { 5766 Matches.clear(); 5767 5768 Matches.addDecl(Method, P.getAccess()); 5769 if (Method->getTemplateSpecializationKind() == TSK_Undeclared) 5770 break; 5771 } 5772 } 5773 } 5774 5775 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev); 5776 if (!FunTmpl) 5777 continue; 5778 5779 TemplateDeductionInfo Info(Context, D.getIdentifierLoc()); 5780 FunctionDecl *Specialization = 0; 5781 if (TemplateDeductionResult TDK 5782 = DeduceTemplateArguments(FunTmpl, 5783 (HasExplicitTemplateArgs ? &TemplateArgs : 0), 5784 R, Specialization, Info)) { 5785 // FIXME: Keep track of almost-matches? 5786 (void)TDK; 5787 continue; 5788 } 5789 5790 Matches.addDecl(Specialization, P.getAccess()); 5791 } 5792 5793 // Find the most specialized function template specialization. 5794 UnresolvedSetIterator Result 5795 = getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other, 0, 5796 D.getIdentifierLoc(), 5797 PDiag(diag::err_explicit_instantiation_not_known) << Name, 5798 PDiag(diag::err_explicit_instantiation_ambiguous) << Name, 5799 PDiag(diag::note_explicit_instantiation_candidate)); 5800 5801 if (Result == Matches.end()) 5802 return true; 5803 5804 // Ignore access control bits, we don't need them for redeclaration checking. 5805 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 5806 5807 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) { 5808 Diag(D.getIdentifierLoc(), 5809 diag::err_explicit_instantiation_member_function_not_instantiated) 5810 << Specialization 5811 << (Specialization->getTemplateSpecializationKind() == 5812 TSK_ExplicitSpecialization); 5813 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here); 5814 return true; 5815 } 5816 5817 FunctionDecl *PrevDecl = Specialization->getPreviousDeclaration(); 5818 if (!PrevDecl && Specialization->isThisDeclarationADefinition()) 5819 PrevDecl = Specialization; 5820 5821 if (PrevDecl) { 5822 bool HasNoEffect = false; 5823 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, 5824 PrevDecl, 5825 PrevDecl->getTemplateSpecializationKind(), 5826 PrevDecl->getPointOfInstantiation(), 5827 HasNoEffect)) 5828 return true; 5829 5830 // FIXME: We may still want to build some representation of this 5831 // explicit specialization. 5832 if (HasNoEffect) 5833 return (Decl*) 0; 5834 } 5835 5836 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5837 5838 if (TSK == TSK_ExplicitInstantiationDefinition) 5839 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization); 5840 5841 // C++0x [temp.explicit]p2: 5842 // If the explicit instantiation is for a member function, a member class 5843 // or a static data member of a class template specialization, the name of 5844 // the class template specialization in the qualified-id for the member 5845 // name shall be a simple-template-id. 5846 // 5847 // C++98 has the same restriction, just worded differently. 5848 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate(); 5849 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl && 5850 D.getCXXScopeSpec().isSet() && 5851 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5852 Diag(D.getIdentifierLoc(), 5853 diag::ext_explicit_instantiation_without_qualified_id) 5854 << Specialization << D.getCXXScopeSpec().getRange(); 5855 5856 CheckExplicitInstantiationScope(*this, 5857 FunTmpl? (NamedDecl *)FunTmpl 5858 : Specialization->getInstantiatedFromMemberFunction(), 5859 D.getIdentifierLoc(), 5860 D.getCXXScopeSpec().isSet()); 5861 5862 // FIXME: Create some kind of ExplicitInstantiationDecl here. 5863 return (Decl*) 0; 5864} 5865 5866TypeResult 5867Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 5868 const CXXScopeSpec &SS, IdentifierInfo *Name, 5869 SourceLocation TagLoc, SourceLocation NameLoc) { 5870 // This has to hold, because SS is expected to be defined. 5871 assert(Name && "Expected a name in a dependent tag"); 5872 5873 NestedNameSpecifier *NNS 5874 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5875 if (!NNS) 5876 return true; 5877 5878 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 5879 5880 if (TUK == TUK_Declaration || TUK == TUK_Definition) { 5881 Diag(NameLoc, diag::err_dependent_tag_decl) 5882 << (TUK == TUK_Definition) << Kind << SS.getRange(); 5883 return true; 5884 } 5885 5886 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 5887 return ParsedType::make(Context.getDependentNameType(Kwd, NNS, Name)); 5888} 5889 5890TypeResult 5891Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5892 const CXXScopeSpec &SS, const IdentifierInfo &II, 5893 SourceLocation IdLoc) { 5894 NestedNameSpecifier *NNS 5895 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5896 if (!NNS) 5897 return true; 5898 5899 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5900 !getLangOptions().CPlusPlus0x) 5901 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5902 << FixItHint::CreateRemoval(TypenameLoc); 5903 5904 QualType T = CheckTypenameType(ETK_Typename, NNS, II, 5905 TypenameLoc, SS.getRange(), IdLoc); 5906 if (T.isNull()) 5907 return true; 5908 5909 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5910 if (isa<DependentNameType>(T)) { 5911 DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc()); 5912 TL.setKeywordLoc(TypenameLoc); 5913 TL.setQualifierRange(SS.getRange()); 5914 TL.setNameLoc(IdLoc); 5915 } else { 5916 ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc()); 5917 TL.setKeywordLoc(TypenameLoc); 5918 TL.setQualifierRange(SS.getRange()); 5919 cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(IdLoc); 5920 } 5921 5922 return CreateParsedType(T, TSI); 5923} 5924 5925TypeResult 5926Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5927 const CXXScopeSpec &SS, SourceLocation TemplateLoc, 5928 ParsedType Ty) { 5929 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5930 !getLangOptions().CPlusPlus0x) 5931 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5932 << FixItHint::CreateRemoval(TypenameLoc); 5933 5934 TypeSourceInfo *InnerTSI = 0; 5935 QualType T = GetTypeFromParser(Ty, &InnerTSI); 5936 5937 assert(isa<TemplateSpecializationType>(T) && 5938 "Expected a template specialization type"); 5939 5940 if (computeDeclContext(SS, false)) { 5941 // If we can compute a declaration context, then the "typename" 5942 // keyword was superfluous. Just build an ElaboratedType to keep 5943 // track of the nested-name-specifier. 5944 5945 // Push the inner type, preserving its source locations if possible. 5946 TypeLocBuilder Builder; 5947 if (InnerTSI) 5948 Builder.pushFullCopy(InnerTSI->getTypeLoc()); 5949 else 5950 Builder.push<TemplateSpecializationTypeLoc>(T).initialize(Context, 5951 TemplateLoc); 5952 5953 /* Note: NNS already embedded in template specialization type T. */ 5954 T = Context.getElaboratedType(ETK_Typename, /*NNS=*/0, T); 5955 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T); 5956 TL.setKeywordLoc(TypenameLoc); 5957 TL.setQualifierRange(SS.getRange()); 5958 5959 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T); 5960 return CreateParsedType(T, TSI); 5961 } 5962 5963 // TODO: it's really silly that we make a template specialization 5964 // type earlier only to drop it again here. 5965 const TemplateSpecializationType *TST = cast<TemplateSpecializationType>(T); 5966 DependentTemplateName *DTN = 5967 TST->getTemplateName().getAsDependentTemplateName(); 5968 assert(DTN && "dependent template has non-dependent name?"); 5969 assert(DTN->getQualifier() 5970 == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); 5971 T = Context.getDependentTemplateSpecializationType(ETK_Typename, 5972 DTN->getQualifier(), 5973 DTN->getIdentifier(), 5974 TST->getNumArgs(), 5975 TST->getArgs()); 5976 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5977 DependentTemplateSpecializationTypeLoc TL = 5978 cast<DependentTemplateSpecializationTypeLoc>(TSI->getTypeLoc()); 5979 if (InnerTSI) { 5980 TemplateSpecializationTypeLoc TSTL = 5981 cast<TemplateSpecializationTypeLoc>(InnerTSI->getTypeLoc()); 5982 TL.setLAngleLoc(TSTL.getLAngleLoc()); 5983 TL.setRAngleLoc(TSTL.getRAngleLoc()); 5984 for (unsigned I = 0, E = TST->getNumArgs(); I != E; ++I) 5985 TL.setArgLocInfo(I, TSTL.getArgLocInfo(I)); 5986 } else { 5987 // FIXME: Poor source-location information here. 5988 TL.initializeLocal(Context, TemplateLoc); 5989 } 5990 TL.setKeywordLoc(TypenameLoc); 5991 TL.setQualifierRange(SS.getRange()); 5992 return CreateParsedType(T, TSI); 5993} 5994 5995/// \brief Build the type that describes a C++ typename specifier, 5996/// e.g., "typename T::type". 5997QualType 5998Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword, 5999 NestedNameSpecifier *NNS, const IdentifierInfo &II, 6000 SourceLocation KeywordLoc, SourceRange NNSRange, 6001 SourceLocation IILoc) { 6002 CXXScopeSpec SS; 6003 SS.MakeTrivial(Context, NNS, NNSRange); 6004 6005 DeclContext *Ctx = computeDeclContext(SS); 6006 if (!Ctx) { 6007 // If the nested-name-specifier is dependent and couldn't be 6008 // resolved to a type, build a typename type. 6009 assert(NNS->isDependent()); 6010 return Context.getDependentNameType(Keyword, NNS, &II); 6011 } 6012 6013 // If the nested-name-specifier refers to the current instantiation, 6014 // the "typename" keyword itself is superfluous. In C++03, the 6015 // program is actually ill-formed. However, DR 382 (in C++0x CD1) 6016 // allows such extraneous "typename" keywords, and we retroactively 6017 // apply this DR to C++03 code with only a warning. In any case we continue. 6018 6019 if (RequireCompleteDeclContext(SS, Ctx)) 6020 return QualType(); 6021 6022 DeclarationName Name(&II); 6023 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName); 6024 LookupQualifiedName(Result, Ctx); 6025 unsigned DiagID = 0; 6026 Decl *Referenced = 0; 6027 switch (Result.getResultKind()) { 6028 case LookupResult::NotFound: 6029 DiagID = diag::err_typename_nested_not_found; 6030 break; 6031 6032 case LookupResult::FoundUnresolvedValue: { 6033 // We found a using declaration that is a value. Most likely, the using 6034 // declaration itself is meant to have the 'typename' keyword. 6035 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : NNSRange.getBegin(), 6036 IILoc); 6037 Diag(IILoc, diag::err_typename_refers_to_using_value_decl) 6038 << Name << Ctx << FullRange; 6039 if (UnresolvedUsingValueDecl *Using 6040 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){ 6041 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc(); 6042 Diag(Loc, diag::note_using_value_decl_missing_typename) 6043 << FixItHint::CreateInsertion(Loc, "typename "); 6044 } 6045 } 6046 // Fall through to create a dependent typename type, from which we can recover 6047 // better. 6048 6049 case LookupResult::NotFoundInCurrentInstantiation: 6050 // Okay, it's a member of an unknown instantiation. 6051 return Context.getDependentNameType(Keyword, NNS, &II); 6052 6053 case LookupResult::Found: 6054 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) { 6055 // We found a type. Build an ElaboratedType, since the 6056 // typename-specifier was just sugar. 6057 return Context.getElaboratedType(ETK_Typename, NNS, 6058 Context.getTypeDeclType(Type)); 6059 } 6060 6061 DiagID = diag::err_typename_nested_not_type; 6062 Referenced = Result.getFoundDecl(); 6063 break; 6064 6065 6066 llvm_unreachable("unresolved using decl in non-dependent context"); 6067 return QualType(); 6068 6069 case LookupResult::FoundOverloaded: 6070 DiagID = diag::err_typename_nested_not_type; 6071 Referenced = *Result.begin(); 6072 break; 6073 6074 case LookupResult::Ambiguous: 6075 return QualType(); 6076 } 6077 6078 // If we get here, it's because name lookup did not find a 6079 // type. Emit an appropriate diagnostic and return an error. 6080 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : NNSRange.getBegin(), 6081 IILoc); 6082 Diag(IILoc, DiagID) << FullRange << Name << Ctx; 6083 if (Referenced) 6084 Diag(Referenced->getLocation(), diag::note_typename_refers_here) 6085 << Name; 6086 return QualType(); 6087} 6088 6089namespace { 6090 // See Sema::RebuildTypeInCurrentInstantiation 6091 class CurrentInstantiationRebuilder 6092 : public TreeTransform<CurrentInstantiationRebuilder> { 6093 SourceLocation Loc; 6094 DeclarationName Entity; 6095 6096 public: 6097 typedef TreeTransform<CurrentInstantiationRebuilder> inherited; 6098 6099 CurrentInstantiationRebuilder(Sema &SemaRef, 6100 SourceLocation Loc, 6101 DeclarationName Entity) 6102 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef), 6103 Loc(Loc), Entity(Entity) { } 6104 6105 /// \brief Determine whether the given type \p T has already been 6106 /// transformed. 6107 /// 6108 /// For the purposes of type reconstruction, a type has already been 6109 /// transformed if it is NULL or if it is not dependent. 6110 bool AlreadyTransformed(QualType T) { 6111 return T.isNull() || !T->isDependentType(); 6112 } 6113 6114 /// \brief Returns the location of the entity whose type is being 6115 /// rebuilt. 6116 SourceLocation getBaseLocation() { return Loc; } 6117 6118 /// \brief Returns the name of the entity whose type is being rebuilt. 6119 DeclarationName getBaseEntity() { return Entity; } 6120 6121 /// \brief Sets the "base" location and entity when that 6122 /// information is known based on another transformation. 6123 void setBase(SourceLocation Loc, DeclarationName Entity) { 6124 this->Loc = Loc; 6125 this->Entity = Entity; 6126 } 6127 }; 6128} 6129 6130/// \brief Rebuilds a type within the context of the current instantiation. 6131/// 6132/// The type \p T is part of the type of an out-of-line member definition of 6133/// a class template (or class template partial specialization) that was parsed 6134/// and constructed before we entered the scope of the class template (or 6135/// partial specialization thereof). This routine will rebuild that type now 6136/// that we have entered the declarator's scope, which may produce different 6137/// canonical types, e.g., 6138/// 6139/// \code 6140/// template<typename T> 6141/// struct X { 6142/// typedef T* pointer; 6143/// pointer data(); 6144/// }; 6145/// 6146/// template<typename T> 6147/// typename X<T>::pointer X<T>::data() { ... } 6148/// \endcode 6149/// 6150/// Here, the type "typename X<T>::pointer" will be created as a DependentNameType, 6151/// since we do not know that we can look into X<T> when we parsed the type. 6152/// This function will rebuild the type, performing the lookup of "pointer" 6153/// in X<T> and returning an ElaboratedType whose canonical type is the same 6154/// as the canonical type of T*, allowing the return types of the out-of-line 6155/// definition and the declaration to match. 6156TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T, 6157 SourceLocation Loc, 6158 DeclarationName Name) { 6159 if (!T || !T->getType()->isDependentType()) 6160 return T; 6161 6162 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name); 6163 return Rebuilder.TransformType(T); 6164} 6165 6166ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) { 6167 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(), 6168 DeclarationName()); 6169 return Rebuilder.TransformExpr(E); 6170} 6171 6172bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) { 6173 if (SS.isInvalid()) 6174 return true; 6175 6176 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); 6177 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(), 6178 DeclarationName()); 6179 NestedNameSpecifierLoc Rebuilt 6180 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc); 6181 if (!Rebuilt) 6182 return true; 6183 6184 SS.Adopt(Rebuilt); 6185 return false; 6186} 6187 6188/// \brief Produces a formatted string that describes the binding of 6189/// template parameters to template arguments. 6190std::string 6191Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 6192 const TemplateArgumentList &Args) { 6193 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size()); 6194} 6195 6196std::string 6197Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 6198 const TemplateArgument *Args, 6199 unsigned NumArgs) { 6200 llvm::SmallString<128> Str; 6201 llvm::raw_svector_ostream Out(Str); 6202 6203 if (!Params || Params->size() == 0 || NumArgs == 0) 6204 return std::string(); 6205 6206 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 6207 if (I >= NumArgs) 6208 break; 6209 6210 if (I == 0) 6211 Out << "[with "; 6212 else 6213 Out << ", "; 6214 6215 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) { 6216 Out << Id->getName(); 6217 } else { 6218 Out << '$' << I; 6219 } 6220 6221 Out << " = "; 6222 Args[I].print(Context.PrintingPolicy, Out); 6223 } 6224 6225 Out << ']'; 6226 return Out.str(); 6227} 6228