SemaTemplate.cpp revision bfc2eaa077e7f914cfbf35ffdf53da889847838c
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/Sema/DeclSpec.h" 24#include "clang/Sema/ParsedTemplate.h" 25#include "clang/Basic/LangOptions.h" 26#include "clang/Basic/PartialDiagnostic.h" 27#include "llvm/ADT/StringExtras.h" 28using namespace clang; 29using namespace sema; 30 31/// \brief Determine whether the declaration found is acceptable as the name 32/// of a template and, if so, return that template declaration. Otherwise, 33/// returns NULL. 34static NamedDecl *isAcceptableTemplateName(ASTContext &Context, 35 NamedDecl *Orig) { 36 NamedDecl *D = Orig->getUnderlyingDecl(); 37 38 if (isa<TemplateDecl>(D)) 39 return Orig; 40 41 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) { 42 // C++ [temp.local]p1: 43 // Like normal (non-template) classes, class templates have an 44 // injected-class-name (Clause 9). The injected-class-name 45 // can be used with or without a template-argument-list. When 46 // it is used without a template-argument-list, it is 47 // equivalent to the injected-class-name followed by the 48 // template-parameters of the class template enclosed in 49 // <>. When it is used with a template-argument-list, it 50 // refers to the specified class template specialization, 51 // which could be the current specialization or another 52 // specialization. 53 if (Record->isInjectedClassName()) { 54 Record = cast<CXXRecordDecl>(Record->getDeclContext()); 55 if (Record->getDescribedClassTemplate()) 56 return Record->getDescribedClassTemplate(); 57 58 if (ClassTemplateSpecializationDecl *Spec 59 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) 60 return Spec->getSpecializedTemplate(); 61 } 62 63 return 0; 64 } 65 66 return 0; 67} 68 69static void FilterAcceptableTemplateNames(ASTContext &C, LookupResult &R) { 70 // The set of class templates we've already seen. 71 llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates; 72 LookupResult::Filter filter = R.makeFilter(); 73 while (filter.hasNext()) { 74 NamedDecl *Orig = filter.next(); 75 NamedDecl *Repl = isAcceptableTemplateName(C, Orig); 76 if (!Repl) 77 filter.erase(); 78 else if (Repl != Orig) { 79 80 // C++ [temp.local]p3: 81 // A lookup that finds an injected-class-name (10.2) can result in an 82 // ambiguity in certain cases (for example, if it is found in more than 83 // one base class). If all of the injected-class-names that are found 84 // refer to specializations of the same class template, and if the name 85 // is followed by a template-argument-list, the reference refers to the 86 // class template itself and not a specialization thereof, and is not 87 // ambiguous. 88 // 89 // FIXME: Will we eventually have to do the same for alias templates? 90 if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl)) 91 if (!ClassTemplates.insert(ClassTmpl)) { 92 filter.erase(); 93 continue; 94 } 95 96 // FIXME: we promote access to public here as a workaround to 97 // the fact that LookupResult doesn't let us remember that we 98 // found this template through a particular injected class name, 99 // which means we end up doing nasty things to the invariants. 100 // Pretending that access is public is *much* safer. 101 filter.replace(Repl, AS_public); 102 } 103 } 104 filter.done(); 105} 106 107TemplateNameKind Sema::isTemplateName(Scope *S, 108 CXXScopeSpec &SS, 109 bool hasTemplateKeyword, 110 UnqualifiedId &Name, 111 ParsedType ObjectTypePtr, 112 bool EnteringContext, 113 TemplateTy &TemplateResult, 114 bool &MemberOfUnknownSpecialization) { 115 assert(getLangOptions().CPlusPlus && "No template names in C!"); 116 117 DeclarationName TName; 118 MemberOfUnknownSpecialization = false; 119 120 switch (Name.getKind()) { 121 case UnqualifiedId::IK_Identifier: 122 TName = DeclarationName(Name.Identifier); 123 break; 124 125 case UnqualifiedId::IK_OperatorFunctionId: 126 TName = Context.DeclarationNames.getCXXOperatorName( 127 Name.OperatorFunctionId.Operator); 128 break; 129 130 case UnqualifiedId::IK_LiteralOperatorId: 131 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier); 132 break; 133 134 default: 135 return TNK_Non_template; 136 } 137 138 QualType ObjectType = ObjectTypePtr.get(); 139 140 LookupResult R(*this, TName, Name.getSourceRange().getBegin(), 141 LookupOrdinaryName); 142 LookupTemplateName(R, S, SS, ObjectType, EnteringContext, 143 MemberOfUnknownSpecialization); 144 if (R.empty()) return TNK_Non_template; 145 if (R.isAmbiguous()) { 146 // Suppress diagnostics; we'll redo this lookup later. 147 R.suppressDiagnostics(); 148 149 // FIXME: we might have ambiguous templates, in which case we 150 // should at least parse them properly! 151 return TNK_Non_template; 152 } 153 154 TemplateName Template; 155 TemplateNameKind TemplateKind; 156 157 unsigned ResultCount = R.end() - R.begin(); 158 if (ResultCount > 1) { 159 // We assume that we'll preserve the qualifier from a function 160 // template name in other ways. 161 Template = Context.getOverloadedTemplateName(R.begin(), R.end()); 162 TemplateKind = TNK_Function_template; 163 164 // We'll do this lookup again later. 165 R.suppressDiagnostics(); 166 } else { 167 TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl()); 168 169 if (SS.isSet() && !SS.isInvalid()) { 170 NestedNameSpecifier *Qualifier 171 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 172 Template = Context.getQualifiedTemplateName(Qualifier, 173 hasTemplateKeyword, TD); 174 } else { 175 Template = TemplateName(TD); 176 } 177 178 if (isa<FunctionTemplateDecl>(TD)) { 179 TemplateKind = TNK_Function_template; 180 181 // We'll do this lookup again later. 182 R.suppressDiagnostics(); 183 } else { 184 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD)); 185 TemplateKind = TNK_Type_template; 186 } 187 } 188 189 TemplateResult = TemplateTy::make(Template); 190 return TemplateKind; 191} 192 193bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II, 194 SourceLocation IILoc, 195 Scope *S, 196 const CXXScopeSpec *SS, 197 TemplateTy &SuggestedTemplate, 198 TemplateNameKind &SuggestedKind) { 199 // We can't recover unless there's a dependent scope specifier preceding the 200 // template name. 201 // FIXME: Typo correction? 202 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) || 203 computeDeclContext(*SS)) 204 return false; 205 206 // The code is missing a 'template' keyword prior to the dependent template 207 // name. 208 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep(); 209 Diag(IILoc, diag::err_template_kw_missing) 210 << Qualifier << II.getName() 211 << FixItHint::CreateInsertion(IILoc, "template "); 212 SuggestedTemplate 213 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II)); 214 SuggestedKind = TNK_Dependent_template_name; 215 return true; 216} 217 218void Sema::LookupTemplateName(LookupResult &Found, 219 Scope *S, CXXScopeSpec &SS, 220 QualType ObjectType, 221 bool EnteringContext, 222 bool &MemberOfUnknownSpecialization) { 223 // Determine where to perform name lookup 224 MemberOfUnknownSpecialization = false; 225 DeclContext *LookupCtx = 0; 226 bool isDependent = false; 227 if (!ObjectType.isNull()) { 228 // This nested-name-specifier occurs in a member access expression, e.g., 229 // x->B::f, and we are looking into the type of the object. 230 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 231 LookupCtx = computeDeclContext(ObjectType); 232 isDependent = ObjectType->isDependentType(); 233 assert((isDependent || !ObjectType->isIncompleteType()) && 234 "Caller should have completed object type"); 235 } else if (SS.isSet()) { 236 // This nested-name-specifier occurs after another nested-name-specifier, 237 // so long into the context associated with the prior nested-name-specifier. 238 LookupCtx = computeDeclContext(SS, EnteringContext); 239 isDependent = isDependentScopeSpecifier(SS); 240 241 // The declaration context must be complete. 242 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx)) 243 return; 244 } 245 246 bool ObjectTypeSearchedInScope = false; 247 if (LookupCtx) { 248 // Perform "qualified" name lookup into the declaration context we 249 // computed, which is either the type of the base of a member access 250 // expression or the declaration context associated with a prior 251 // nested-name-specifier. 252 LookupQualifiedName(Found, LookupCtx); 253 254 if (!ObjectType.isNull() && Found.empty()) { 255 // C++ [basic.lookup.classref]p1: 256 // In a class member access expression (5.2.5), if the . or -> token is 257 // immediately followed by an identifier followed by a <, the 258 // identifier must be looked up to determine whether the < is the 259 // beginning of a template argument list (14.2) or a less-than operator. 260 // The identifier is first looked up in the class of the object 261 // expression. If the identifier is not found, it is then looked up in 262 // the context of the entire postfix-expression and shall name a class 263 // or function template. 264 if (S) LookupName(Found, S); 265 ObjectTypeSearchedInScope = true; 266 } 267 } else if (isDependent && (!S || ObjectType.isNull())) { 268 // We cannot look into a dependent object type or nested nme 269 // specifier. 270 MemberOfUnknownSpecialization = true; 271 return; 272 } else { 273 // Perform unqualified name lookup in the current scope. 274 LookupName(Found, S); 275 } 276 277 if (Found.empty() && !isDependent) { 278 // If we did not find any names, attempt to correct any typos. 279 DeclarationName Name = Found.getLookupName(); 280 if (DeclarationName Corrected = CorrectTypo(Found, S, &SS, LookupCtx, 281 false, CTC_CXXCasts)) { 282 FilterAcceptableTemplateNames(Context, Found); 283 if (!Found.empty()) { 284 if (LookupCtx) 285 Diag(Found.getNameLoc(), diag::err_no_member_template_suggest) 286 << Name << LookupCtx << Found.getLookupName() << SS.getRange() 287 << FixItHint::CreateReplacement(Found.getNameLoc(), 288 Found.getLookupName().getAsString()); 289 else 290 Diag(Found.getNameLoc(), diag::err_no_template_suggest) 291 << Name << Found.getLookupName() 292 << FixItHint::CreateReplacement(Found.getNameLoc(), 293 Found.getLookupName().getAsString()); 294 if (TemplateDecl *Template = Found.getAsSingle<TemplateDecl>()) 295 Diag(Template->getLocation(), diag::note_previous_decl) 296 << Template->getDeclName(); 297 } 298 } else { 299 Found.clear(); 300 Found.setLookupName(Name); 301 } 302 } 303 304 FilterAcceptableTemplateNames(Context, Found); 305 if (Found.empty()) { 306 if (isDependent) 307 MemberOfUnknownSpecialization = true; 308 return; 309 } 310 311 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope) { 312 // C++ [basic.lookup.classref]p1: 313 // [...] If the lookup in the class of the object expression finds a 314 // template, the name is also looked up in the context of the entire 315 // postfix-expression and [...] 316 // 317 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(), 318 LookupOrdinaryName); 319 LookupName(FoundOuter, S); 320 FilterAcceptableTemplateNames(Context, FoundOuter); 321 322 if (FoundOuter.empty()) { 323 // - if the name is not found, the name found in the class of the 324 // object expression is used, otherwise 325 } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>()) { 326 // - if the name is found in the context of the entire 327 // postfix-expression and does not name a class template, the name 328 // found in the class of the object expression is used, otherwise 329 } else if (!Found.isSuppressingDiagnostics()) { 330 // - if the name found is a class template, it must refer to the same 331 // entity as the one found in the class of the object expression, 332 // otherwise the program is ill-formed. 333 if (!Found.isSingleResult() || 334 Found.getFoundDecl()->getCanonicalDecl() 335 != FoundOuter.getFoundDecl()->getCanonicalDecl()) { 336 Diag(Found.getNameLoc(), 337 diag::ext_nested_name_member_ref_lookup_ambiguous) 338 << Found.getLookupName() 339 << ObjectType; 340 Diag(Found.getRepresentativeDecl()->getLocation(), 341 diag::note_ambig_member_ref_object_type) 342 << ObjectType; 343 Diag(FoundOuter.getFoundDecl()->getLocation(), 344 diag::note_ambig_member_ref_scope); 345 346 // Recover by taking the template that we found in the object 347 // expression's type. 348 } 349 } 350 } 351} 352 353/// ActOnDependentIdExpression - Handle a dependent id-expression that 354/// was just parsed. This is only possible with an explicit scope 355/// specifier naming a dependent type. 356ExprResult 357Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS, 358 const DeclarationNameInfo &NameInfo, 359 bool isAddressOfOperand, 360 const TemplateArgumentListInfo *TemplateArgs) { 361 NestedNameSpecifier *Qualifier 362 = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 363 364 DeclContext *DC = getFunctionLevelDeclContext(); 365 366 if (!isAddressOfOperand && 367 isa<CXXMethodDecl>(DC) && 368 cast<CXXMethodDecl>(DC)->isInstance()) { 369 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 370 371 // Since the 'this' expression is synthesized, we don't need to 372 // perform the double-lookup check. 373 NamedDecl *FirstQualifierInScope = 0; 374 375 return Owned(CXXDependentScopeMemberExpr::Create(Context, 376 /*This*/ 0, ThisType, 377 /*IsArrow*/ true, 378 /*Op*/ SourceLocation(), 379 Qualifier, SS.getRange(), 380 FirstQualifierInScope, 381 NameInfo, 382 TemplateArgs)); 383 } 384 385 return BuildDependentDeclRefExpr(SS, NameInfo, TemplateArgs); 386} 387 388ExprResult 389Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS, 390 const DeclarationNameInfo &NameInfo, 391 const TemplateArgumentListInfo *TemplateArgs) { 392 return Owned(DependentScopeDeclRefExpr::Create(Context, 393 static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 394 SS.getRange(), 395 NameInfo, 396 TemplateArgs)); 397} 398 399/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining 400/// that the template parameter 'PrevDecl' is being shadowed by a new 401/// declaration at location Loc. Returns true to indicate that this is 402/// an error, and false otherwise. 403bool Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { 404 assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); 405 406 // Microsoft Visual C++ permits template parameters to be shadowed. 407 if (getLangOptions().Microsoft) 408 return false; 409 410 // C++ [temp.local]p4: 411 // A template-parameter shall not be redeclared within its 412 // scope (including nested scopes). 413 Diag(Loc, diag::err_template_param_shadow) 414 << cast<NamedDecl>(PrevDecl)->getDeclName(); 415 Diag(PrevDecl->getLocation(), diag::note_template_param_here); 416 return true; 417} 418 419/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset 420/// the parameter D to reference the templated declaration and return a pointer 421/// to the template declaration. Otherwise, do nothing to D and return null. 422TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) { 423 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) { 424 D = Temp->getTemplatedDecl(); 425 return Temp; 426 } 427 return 0; 428} 429 430static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef, 431 const ParsedTemplateArgument &Arg) { 432 433 switch (Arg.getKind()) { 434 case ParsedTemplateArgument::Type: { 435 TypeSourceInfo *DI; 436 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI); 437 if (!DI) 438 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation()); 439 return TemplateArgumentLoc(TemplateArgument(T), DI); 440 } 441 442 case ParsedTemplateArgument::NonType: { 443 Expr *E = static_cast<Expr *>(Arg.getAsExpr()); 444 return TemplateArgumentLoc(TemplateArgument(E), E); 445 } 446 447 case ParsedTemplateArgument::Template: { 448 TemplateName Template = Arg.getAsTemplate().get(); 449 return TemplateArgumentLoc(TemplateArgument(Template), 450 Arg.getScopeSpec().getRange(), 451 Arg.getLocation()); 452 } 453 } 454 455 llvm_unreachable("Unhandled parsed template argument"); 456 return TemplateArgumentLoc(); 457} 458 459/// \brief Translates template arguments as provided by the parser 460/// into template arguments used by semantic analysis. 461void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn, 462 TemplateArgumentListInfo &TemplateArgs) { 463 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I) 464 TemplateArgs.addArgument(translateTemplateArgument(*this, 465 TemplateArgsIn[I])); 466} 467 468/// ActOnTypeParameter - Called when a C++ template type parameter 469/// (e.g., "typename T") has been parsed. Typename specifies whether 470/// the keyword "typename" was used to declare the type parameter 471/// (otherwise, "class" was used), and KeyLoc is the location of the 472/// "class" or "typename" keyword. ParamName is the name of the 473/// parameter (NULL indicates an unnamed template parameter) and 474/// ParamName is the location of the parameter name (if any). 475/// If the type parameter has a default argument, it will be added 476/// later via ActOnTypeParameterDefault. 477Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis, 478 SourceLocation EllipsisLoc, 479 SourceLocation KeyLoc, 480 IdentifierInfo *ParamName, 481 SourceLocation ParamNameLoc, 482 unsigned Depth, unsigned Position, 483 SourceLocation EqualLoc, 484 ParsedType DefaultArg) { 485 assert(S->isTemplateParamScope() && 486 "Template type parameter not in template parameter scope!"); 487 bool Invalid = false; 488 489 if (ParamName) { 490 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, ParamNameLoc, 491 LookupOrdinaryName, 492 ForRedeclaration); 493 if (PrevDecl && PrevDecl->isTemplateParameter()) 494 Invalid = Invalid || DiagnoseTemplateParameterShadow(ParamNameLoc, 495 PrevDecl); 496 } 497 498 SourceLocation Loc = ParamNameLoc; 499 if (!ParamName) 500 Loc = KeyLoc; 501 502 TemplateTypeParmDecl *Param 503 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(), 504 Loc, Depth, Position, ParamName, Typename, 505 Ellipsis); 506 if (Invalid) 507 Param->setInvalidDecl(); 508 509 if (ParamName) { 510 // Add the template parameter into the current scope. 511 S->AddDecl(Param); 512 IdResolver.AddDecl(Param); 513 } 514 515 // Handle the default argument, if provided. 516 if (DefaultArg) { 517 TypeSourceInfo *DefaultTInfo; 518 GetTypeFromParser(DefaultArg, &DefaultTInfo); 519 520 assert(DefaultTInfo && "expected source information for type"); 521 522 // C++0x [temp.param]p9: 523 // A default template-argument may be specified for any kind of 524 // template-parameter that is not a template parameter pack. 525 if (Ellipsis) { 526 Diag(EqualLoc, diag::err_template_param_pack_default_arg); 527 return Param; 528 } 529 530 // Check the template argument itself. 531 if (CheckTemplateArgument(Param, DefaultTInfo)) { 532 Param->setInvalidDecl(); 533 return Param; 534 } 535 536 Param->setDefaultArgument(DefaultTInfo, false); 537 } 538 539 return Param; 540} 541 542/// \brief Check that the type of a non-type template parameter is 543/// well-formed. 544/// 545/// \returns the (possibly-promoted) parameter type if valid; 546/// otherwise, produces a diagnostic and returns a NULL type. 547QualType 548Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) { 549 // We don't allow variably-modified types as the type of non-type template 550 // parameters. 551 if (T->isVariablyModifiedType()) { 552 Diag(Loc, diag::err_variably_modified_nontype_template_param) 553 << T; 554 return QualType(); 555 } 556 557 // C++ [temp.param]p4: 558 // 559 // A non-type template-parameter shall have one of the following 560 // (optionally cv-qualified) types: 561 // 562 // -- integral or enumeration type, 563 if (T->isIntegralOrEnumerationType() || 564 // -- pointer to object or pointer to function, 565 T->isPointerType() || 566 // -- reference to object or reference to function, 567 T->isReferenceType() || 568 // -- pointer to member. 569 T->isMemberPointerType() || 570 // If T is a dependent type, we can't do the check now, so we 571 // assume that it is well-formed. 572 T->isDependentType()) 573 return T; 574 // C++ [temp.param]p8: 575 // 576 // A non-type template-parameter of type "array of T" or 577 // "function returning T" is adjusted to be of type "pointer to 578 // T" or "pointer to function returning T", respectively. 579 else if (T->isArrayType()) 580 // FIXME: Keep the type prior to promotion? 581 return Context.getArrayDecayedType(T); 582 else if (T->isFunctionType()) 583 // FIXME: Keep the type prior to promotion? 584 return Context.getPointerType(T); 585 586 Diag(Loc, diag::err_template_nontype_parm_bad_type) 587 << T; 588 589 return QualType(); 590} 591 592Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D, 593 unsigned Depth, 594 unsigned Position, 595 SourceLocation EqualLoc, 596 Expr *Default) { 597 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 598 QualType T = TInfo->getType(); 599 600 assert(S->isTemplateParamScope() && 601 "Non-type template parameter not in template parameter scope!"); 602 bool Invalid = false; 603 604 IdentifierInfo *ParamName = D.getIdentifier(); 605 if (ParamName) { 606 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, D.getIdentifierLoc(), 607 LookupOrdinaryName, 608 ForRedeclaration); 609 if (PrevDecl && PrevDecl->isTemplateParameter()) 610 Invalid = Invalid || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), 611 PrevDecl); 612 } 613 614 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc()); 615 if (T.isNull()) { 616 T = Context.IntTy; // Recover with an 'int' type. 617 Invalid = true; 618 } 619 620 NonTypeTemplateParmDecl *Param 621 = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 622 D.getIdentifierLoc(), 623 Depth, Position, ParamName, T, TInfo); 624 if (Invalid) 625 Param->setInvalidDecl(); 626 627 if (D.getIdentifier()) { 628 // Add the template parameter into the current scope. 629 S->AddDecl(Param); 630 IdResolver.AddDecl(Param); 631 } 632 633 // Check the well-formedness of the default template argument, if provided. 634 if (Default) { 635 TemplateArgument Converted; 636 if (CheckTemplateArgument(Param, Param->getType(), Default, Converted)) { 637 Param->setInvalidDecl(); 638 return Param; 639 } 640 641 Param->setDefaultArgument(Default, false); 642 } 643 644 return Param; 645} 646 647/// ActOnTemplateTemplateParameter - Called when a C++ template template 648/// parameter (e.g. T in template <template <typename> class T> class array) 649/// has been parsed. S is the current scope. 650Decl *Sema::ActOnTemplateTemplateParameter(Scope* S, 651 SourceLocation TmpLoc, 652 TemplateParamsTy *Params, 653 IdentifierInfo *Name, 654 SourceLocation NameLoc, 655 unsigned Depth, 656 unsigned Position, 657 SourceLocation EqualLoc, 658 const ParsedTemplateArgument &Default) { 659 assert(S->isTemplateParamScope() && 660 "Template template parameter not in template parameter scope!"); 661 662 // Construct the parameter object. 663 TemplateTemplateParmDecl *Param = 664 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), 665 NameLoc.isInvalid()? TmpLoc : NameLoc, 666 Depth, Position, Name, 667 (TemplateParameterList*)Params); 668 669 // If the template template parameter has a name, then link the identifier 670 // into the scope and lookup mechanisms. 671 if (Name) { 672 S->AddDecl(Param); 673 IdResolver.AddDecl(Param); 674 } 675 676 if (!Default.isInvalid()) { 677 // Check only that we have a template template argument. We don't want to 678 // try to check well-formedness now, because our template template parameter 679 // might have dependent types in its template parameters, which we wouldn't 680 // be able to match now. 681 // 682 // If none of the template template parameter's template arguments mention 683 // other template parameters, we could actually perform more checking here. 684 // However, it isn't worth doing. 685 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default); 686 if (DefaultArg.getArgument().getAsTemplate().isNull()) { 687 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template) 688 << DefaultArg.getSourceRange(); 689 return Param; 690 } 691 692 Param->setDefaultArgument(DefaultArg, false); 693 } 694 695 return Param; 696} 697 698/// ActOnTemplateParameterList - Builds a TemplateParameterList that 699/// contains the template parameters in Params/NumParams. 700Sema::TemplateParamsTy * 701Sema::ActOnTemplateParameterList(unsigned Depth, 702 SourceLocation ExportLoc, 703 SourceLocation TemplateLoc, 704 SourceLocation LAngleLoc, 705 Decl **Params, unsigned NumParams, 706 SourceLocation RAngleLoc) { 707 if (ExportLoc.isValid()) 708 Diag(ExportLoc, diag::warn_template_export_unsupported); 709 710 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc, 711 (NamedDecl**)Params, NumParams, 712 RAngleLoc); 713} 714 715static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) { 716 if (SS.isSet()) 717 T->setQualifierInfo(static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 718 SS.getRange()); 719} 720 721DeclResult 722Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK, 723 SourceLocation KWLoc, CXXScopeSpec &SS, 724 IdentifierInfo *Name, SourceLocation NameLoc, 725 AttributeList *Attr, 726 TemplateParameterList *TemplateParams, 727 AccessSpecifier AS) { 728 assert(TemplateParams && TemplateParams->size() > 0 && 729 "No template parameters"); 730 assert(TUK != TUK_Reference && "Can only declare or define class templates"); 731 bool Invalid = false; 732 733 // Check that we can declare a template here. 734 if (CheckTemplateDeclScope(S, TemplateParams)) 735 return true; 736 737 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 738 assert(Kind != TTK_Enum && "can't build template of enumerated type"); 739 740 // There is no such thing as an unnamed class template. 741 if (!Name) { 742 Diag(KWLoc, diag::err_template_unnamed_class); 743 return true; 744 } 745 746 // Find any previous declaration with this name. 747 DeclContext *SemanticContext; 748 LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName, 749 ForRedeclaration); 750 if (SS.isNotEmpty() && !SS.isInvalid()) { 751 SemanticContext = computeDeclContext(SS, true); 752 if (!SemanticContext) { 753 // FIXME: Produce a reasonable diagnostic here 754 return true; 755 } 756 757 if (RequireCompleteDeclContext(SS, SemanticContext)) 758 return true; 759 760 LookupQualifiedName(Previous, SemanticContext); 761 } else { 762 SemanticContext = CurContext; 763 LookupName(Previous, S); 764 } 765 766 if (Previous.isAmbiguous()) 767 return true; 768 769 NamedDecl *PrevDecl = 0; 770 if (Previous.begin() != Previous.end()) 771 PrevDecl = (*Previous.begin())->getUnderlyingDecl(); 772 773 // If there is a previous declaration with the same name, check 774 // whether this is a valid redeclaration. 775 ClassTemplateDecl *PrevClassTemplate 776 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl); 777 778 // We may have found the injected-class-name of a class template, 779 // class template partial specialization, or class template specialization. 780 // In these cases, grab the template that is being defined or specialized. 781 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) && 782 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) { 783 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext()); 784 PrevClassTemplate 785 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate(); 786 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) { 787 PrevClassTemplate 788 = cast<ClassTemplateSpecializationDecl>(PrevDecl) 789 ->getSpecializedTemplate(); 790 } 791 } 792 793 if (TUK == TUK_Friend) { 794 // C++ [namespace.memdef]p3: 795 // [...] When looking for a prior declaration of a class or a function 796 // declared as a friend, and when the name of the friend class or 797 // function is neither a qualified name nor a template-id, scopes outside 798 // the innermost enclosing namespace scope are not considered. 799 if (!SS.isSet()) { 800 DeclContext *OutermostContext = CurContext; 801 while (!OutermostContext->isFileContext()) 802 OutermostContext = OutermostContext->getLookupParent(); 803 804 if (PrevDecl && 805 (OutermostContext->Equals(PrevDecl->getDeclContext()) || 806 OutermostContext->Encloses(PrevDecl->getDeclContext()))) { 807 SemanticContext = PrevDecl->getDeclContext(); 808 } else { 809 // Declarations in outer scopes don't matter. However, the outermost 810 // context we computed is the semantic context for our new 811 // declaration. 812 PrevDecl = PrevClassTemplate = 0; 813 SemanticContext = OutermostContext; 814 } 815 } 816 817 if (CurContext->isDependentContext()) { 818 // If this is a dependent context, we don't want to link the friend 819 // class template to the template in scope, because that would perform 820 // checking of the template parameter lists that can't be performed 821 // until the outer context is instantiated. 822 PrevDecl = PrevClassTemplate = 0; 823 } 824 } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S)) 825 PrevDecl = PrevClassTemplate = 0; 826 827 if (PrevClassTemplate) { 828 // Ensure that the template parameter lists are compatible. 829 if (!TemplateParameterListsAreEqual(TemplateParams, 830 PrevClassTemplate->getTemplateParameters(), 831 /*Complain=*/true, 832 TPL_TemplateMatch)) 833 return true; 834 835 // C++ [temp.class]p4: 836 // In a redeclaration, partial specialization, explicit 837 // specialization or explicit instantiation of a class template, 838 // the class-key shall agree in kind with the original class 839 // template declaration (7.1.5.3). 840 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl(); 841 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, KWLoc, *Name)) { 842 Diag(KWLoc, diag::err_use_with_wrong_tag) 843 << Name 844 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName()); 845 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use); 846 Kind = PrevRecordDecl->getTagKind(); 847 } 848 849 // Check for redefinition of this class template. 850 if (TUK == TUK_Definition) { 851 if (TagDecl *Def = PrevRecordDecl->getDefinition()) { 852 Diag(NameLoc, diag::err_redefinition) << Name; 853 Diag(Def->getLocation(), diag::note_previous_definition); 854 // FIXME: Would it make sense to try to "forget" the previous 855 // definition, as part of error recovery? 856 return true; 857 } 858 } 859 } else if (PrevDecl && PrevDecl->isTemplateParameter()) { 860 // Maybe we will complain about the shadowed template parameter. 861 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 862 // Just pretend that we didn't see the previous declaration. 863 PrevDecl = 0; 864 } else if (PrevDecl) { 865 // C++ [temp]p5: 866 // A class template shall not have the same name as any other 867 // template, class, function, object, enumeration, enumerator, 868 // namespace, or type in the same scope (3.3), except as specified 869 // in (14.5.4). 870 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 871 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 872 return true; 873 } 874 875 // Check the template parameter list of this declaration, possibly 876 // merging in the template parameter list from the previous class 877 // template declaration. 878 if (CheckTemplateParameterList(TemplateParams, 879 PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0, 880 TPC_ClassTemplate)) 881 Invalid = true; 882 883 if (SS.isSet()) { 884 // If the name of the template was qualified, we must be defining the 885 // template out-of-line. 886 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate && 887 !(TUK == TUK_Friend && CurContext->isDependentContext())) 888 Diag(NameLoc, diag::err_member_def_does_not_match) 889 << Name << SemanticContext << SS.getRange(); 890 } 891 892 CXXRecordDecl *NewClass = 893 CXXRecordDecl::Create(Context, Kind, SemanticContext, NameLoc, Name, KWLoc, 894 PrevClassTemplate? 895 PrevClassTemplate->getTemplatedDecl() : 0, 896 /*DelayTypeCreation=*/true); 897 SetNestedNameSpecifier(NewClass, SS); 898 899 ClassTemplateDecl *NewTemplate 900 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc, 901 DeclarationName(Name), TemplateParams, 902 NewClass, PrevClassTemplate); 903 NewClass->setDescribedClassTemplate(NewTemplate); 904 905 // Build the type for the class template declaration now. 906 QualType T = NewTemplate->getInjectedClassNameSpecialization(); 907 T = Context.getInjectedClassNameType(NewClass, T); 908 assert(T->isDependentType() && "Class template type is not dependent?"); 909 (void)T; 910 911 // If we are providing an explicit specialization of a member that is a 912 // class template, make a note of that. 913 if (PrevClassTemplate && 914 PrevClassTemplate->getInstantiatedFromMemberTemplate()) 915 PrevClassTemplate->setMemberSpecialization(); 916 917 // Set the access specifier. 918 if (!Invalid && TUK != TUK_Friend) 919 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS); 920 921 // Set the lexical context of these templates 922 NewClass->setLexicalDeclContext(CurContext); 923 NewTemplate->setLexicalDeclContext(CurContext); 924 925 if (TUK == TUK_Definition) 926 NewClass->startDefinition(); 927 928 if (Attr) 929 ProcessDeclAttributeList(S, NewClass, Attr); 930 931 if (TUK != TUK_Friend) 932 PushOnScopeChains(NewTemplate, S); 933 else { 934 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) { 935 NewTemplate->setAccess(PrevClassTemplate->getAccess()); 936 NewClass->setAccess(PrevClassTemplate->getAccess()); 937 } 938 939 NewTemplate->setObjectOfFriendDecl(/* PreviouslyDeclared = */ 940 PrevClassTemplate != NULL); 941 942 // Friend templates are visible in fairly strange ways. 943 if (!CurContext->isDependentContext()) { 944 DeclContext *DC = SemanticContext->getRedeclContext(); 945 DC->makeDeclVisibleInContext(NewTemplate, /* Recoverable = */ false); 946 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 947 PushOnScopeChains(NewTemplate, EnclosingScope, 948 /* AddToContext = */ false); 949 } 950 951 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 952 NewClass->getLocation(), 953 NewTemplate, 954 /*FIXME:*/NewClass->getLocation()); 955 Friend->setAccess(AS_public); 956 CurContext->addDecl(Friend); 957 } 958 959 if (Invalid) { 960 NewTemplate->setInvalidDecl(); 961 NewClass->setInvalidDecl(); 962 } 963 return NewTemplate; 964} 965 966/// \brief Diagnose the presence of a default template argument on a 967/// template parameter, which is ill-formed in certain contexts. 968/// 969/// \returns true if the default template argument should be dropped. 970static bool DiagnoseDefaultTemplateArgument(Sema &S, 971 Sema::TemplateParamListContext TPC, 972 SourceLocation ParamLoc, 973 SourceRange DefArgRange) { 974 switch (TPC) { 975 case Sema::TPC_ClassTemplate: 976 return false; 977 978 case Sema::TPC_FunctionTemplate: 979 // C++ [temp.param]p9: 980 // A default template-argument shall not be specified in a 981 // function template declaration or a function template 982 // definition [...] 983 // (This sentence is not in C++0x, per DR226). 984 if (!S.getLangOptions().CPlusPlus0x) 985 S.Diag(ParamLoc, 986 diag::err_template_parameter_default_in_function_template) 987 << DefArgRange; 988 return false; 989 990 case Sema::TPC_ClassTemplateMember: 991 // C++0x [temp.param]p9: 992 // A default template-argument shall not be specified in the 993 // template-parameter-lists of the definition of a member of a 994 // class template that appears outside of the member's class. 995 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member) 996 << DefArgRange; 997 return true; 998 999 case Sema::TPC_FriendFunctionTemplate: 1000 // C++ [temp.param]p9: 1001 // A default template-argument shall not be specified in a 1002 // friend template declaration. 1003 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template) 1004 << DefArgRange; 1005 return true; 1006 1007 // FIXME: C++0x [temp.param]p9 allows default template-arguments 1008 // for friend function templates if there is only a single 1009 // declaration (and it is a definition). Strange! 1010 } 1011 1012 return false; 1013} 1014 1015/// \brief Checks the validity of a template parameter list, possibly 1016/// considering the template parameter list from a previous 1017/// declaration. 1018/// 1019/// If an "old" template parameter list is provided, it must be 1020/// equivalent (per TemplateParameterListsAreEqual) to the "new" 1021/// template parameter list. 1022/// 1023/// \param NewParams Template parameter list for a new template 1024/// declaration. This template parameter list will be updated with any 1025/// default arguments that are carried through from the previous 1026/// template parameter list. 1027/// 1028/// \param OldParams If provided, template parameter list from a 1029/// previous declaration of the same template. Default template 1030/// arguments will be merged from the old template parameter list to 1031/// the new template parameter list. 1032/// 1033/// \param TPC Describes the context in which we are checking the given 1034/// template parameter list. 1035/// 1036/// \returns true if an error occurred, false otherwise. 1037bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams, 1038 TemplateParameterList *OldParams, 1039 TemplateParamListContext TPC) { 1040 bool Invalid = false; 1041 1042 // C++ [temp.param]p10: 1043 // The set of default template-arguments available for use with a 1044 // template declaration or definition is obtained by merging the 1045 // default arguments from the definition (if in scope) and all 1046 // declarations in scope in the same way default function 1047 // arguments are (8.3.6). 1048 bool SawDefaultArgument = false; 1049 SourceLocation PreviousDefaultArgLoc; 1050 1051 bool SawParameterPack = false; 1052 SourceLocation ParameterPackLoc; 1053 1054 // Dummy initialization to avoid warnings. 1055 TemplateParameterList::iterator OldParam = NewParams->end(); 1056 if (OldParams) 1057 OldParam = OldParams->begin(); 1058 1059 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 1060 NewParamEnd = NewParams->end(); 1061 NewParam != NewParamEnd; ++NewParam) { 1062 // Variables used to diagnose redundant default arguments 1063 bool RedundantDefaultArg = false; 1064 SourceLocation OldDefaultLoc; 1065 SourceLocation NewDefaultLoc; 1066 1067 // Variables used to diagnose missing default arguments 1068 bool MissingDefaultArg = false; 1069 1070 // C++0x [temp.param]p11: 1071 // If a template parameter of a class template is a template parameter pack, 1072 // it must be the last template parameter. 1073 if (SawParameterPack) { 1074 Diag(ParameterPackLoc, 1075 diag::err_template_param_pack_must_be_last_template_parameter); 1076 Invalid = true; 1077 } 1078 1079 if (TemplateTypeParmDecl *NewTypeParm 1080 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) { 1081 // Check the presence of a default argument here. 1082 if (NewTypeParm->hasDefaultArgument() && 1083 DiagnoseDefaultTemplateArgument(*this, TPC, 1084 NewTypeParm->getLocation(), 1085 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc() 1086 .getSourceRange())) 1087 NewTypeParm->removeDefaultArgument(); 1088 1089 // Merge default arguments for template type parameters. 1090 TemplateTypeParmDecl *OldTypeParm 1091 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : 0; 1092 1093 if (NewTypeParm->isParameterPack()) { 1094 assert(!NewTypeParm->hasDefaultArgument() && 1095 "Parameter packs can't have a default argument!"); 1096 SawParameterPack = true; 1097 ParameterPackLoc = NewTypeParm->getLocation(); 1098 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() && 1099 NewTypeParm->hasDefaultArgument()) { 1100 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc(); 1101 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc(); 1102 SawDefaultArgument = true; 1103 RedundantDefaultArg = true; 1104 PreviousDefaultArgLoc = NewDefaultLoc; 1105 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) { 1106 // Merge the default argument from the old declaration to the 1107 // new declaration. 1108 SawDefaultArgument = true; 1109 NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(), 1110 true); 1111 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc(); 1112 } else if (NewTypeParm->hasDefaultArgument()) { 1113 SawDefaultArgument = true; 1114 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc(); 1115 } else if (SawDefaultArgument) 1116 MissingDefaultArg = true; 1117 } else if (NonTypeTemplateParmDecl *NewNonTypeParm 1118 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) { 1119 // Check the presence of a default argument here. 1120 if (NewNonTypeParm->hasDefaultArgument() && 1121 DiagnoseDefaultTemplateArgument(*this, TPC, 1122 NewNonTypeParm->getLocation(), 1123 NewNonTypeParm->getDefaultArgument()->getSourceRange())) { 1124 NewNonTypeParm->removeDefaultArgument(); 1125 } 1126 1127 // Merge default arguments for non-type template parameters 1128 NonTypeTemplateParmDecl *OldNonTypeParm 1129 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : 0; 1130 if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() && 1131 NewNonTypeParm->hasDefaultArgument()) { 1132 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1133 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1134 SawDefaultArgument = true; 1135 RedundantDefaultArg = true; 1136 PreviousDefaultArgLoc = NewDefaultLoc; 1137 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) { 1138 // Merge the default argument from the old declaration to the 1139 // new declaration. 1140 SawDefaultArgument = true; 1141 // FIXME: We need to create a new kind of "default argument" 1142 // expression that points to a previous template template 1143 // parameter. 1144 NewNonTypeParm->setDefaultArgument( 1145 OldNonTypeParm->getDefaultArgument(), 1146 /*Inherited=*/ true); 1147 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc(); 1148 } else if (NewNonTypeParm->hasDefaultArgument()) { 1149 SawDefaultArgument = true; 1150 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc(); 1151 } else if (SawDefaultArgument) 1152 MissingDefaultArg = true; 1153 } else { 1154 // Check the presence of a default argument here. 1155 TemplateTemplateParmDecl *NewTemplateParm 1156 = cast<TemplateTemplateParmDecl>(*NewParam); 1157 if (NewTemplateParm->hasDefaultArgument() && 1158 DiagnoseDefaultTemplateArgument(*this, TPC, 1159 NewTemplateParm->getLocation(), 1160 NewTemplateParm->getDefaultArgument().getSourceRange())) 1161 NewTemplateParm->removeDefaultArgument(); 1162 1163 // Merge default arguments for template template parameters 1164 TemplateTemplateParmDecl *OldTemplateParm 1165 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : 0; 1166 if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() && 1167 NewTemplateParm->hasDefaultArgument()) { 1168 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation(); 1169 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation(); 1170 SawDefaultArgument = true; 1171 RedundantDefaultArg = true; 1172 PreviousDefaultArgLoc = NewDefaultLoc; 1173 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) { 1174 // Merge the default argument from the old declaration to the 1175 // new declaration. 1176 SawDefaultArgument = true; 1177 // FIXME: We need to create a new kind of "default argument" expression 1178 // that points to a previous template template parameter. 1179 NewTemplateParm->setDefaultArgument( 1180 OldTemplateParm->getDefaultArgument(), 1181 /*Inherited=*/ true); 1182 PreviousDefaultArgLoc 1183 = OldTemplateParm->getDefaultArgument().getLocation(); 1184 } else if (NewTemplateParm->hasDefaultArgument()) { 1185 SawDefaultArgument = true; 1186 PreviousDefaultArgLoc 1187 = NewTemplateParm->getDefaultArgument().getLocation(); 1188 } else if (SawDefaultArgument) 1189 MissingDefaultArg = true; 1190 } 1191 1192 if (RedundantDefaultArg) { 1193 // C++ [temp.param]p12: 1194 // A template-parameter shall not be given default arguments 1195 // by two different declarations in the same scope. 1196 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition); 1197 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg); 1198 Invalid = true; 1199 } else if (MissingDefaultArg) { 1200 // C++ [temp.param]p11: 1201 // If a template-parameter has a default template-argument, 1202 // all subsequent template-parameters shall have a default 1203 // template-argument supplied. 1204 Diag((*NewParam)->getLocation(), 1205 diag::err_template_param_default_arg_missing); 1206 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg); 1207 Invalid = true; 1208 } 1209 1210 // If we have an old template parameter list that we're merging 1211 // in, move on to the next parameter. 1212 if (OldParams) 1213 ++OldParam; 1214 } 1215 1216 return Invalid; 1217} 1218 1219/// \brief Match the given template parameter lists to the given scope 1220/// specifier, returning the template parameter list that applies to the 1221/// name. 1222/// 1223/// \param DeclStartLoc the start of the declaration that has a scope 1224/// specifier or a template parameter list. 1225/// 1226/// \param SS the scope specifier that will be matched to the given template 1227/// parameter lists. This scope specifier precedes a qualified name that is 1228/// being declared. 1229/// 1230/// \param ParamLists the template parameter lists, from the outermost to the 1231/// innermost template parameter lists. 1232/// 1233/// \param NumParamLists the number of template parameter lists in ParamLists. 1234/// 1235/// \param IsFriend Whether to apply the slightly different rules for 1236/// matching template parameters to scope specifiers in friend 1237/// declarations. 1238/// 1239/// \param IsExplicitSpecialization will be set true if the entity being 1240/// declared is an explicit specialization, false otherwise. 1241/// 1242/// \returns the template parameter list, if any, that corresponds to the 1243/// name that is preceded by the scope specifier @p SS. This template 1244/// parameter list may be have template parameters (if we're declaring a 1245/// template) or may have no template parameters (if we're declaring a 1246/// template specialization), or may be NULL (if we were's declaring isn't 1247/// itself a template). 1248TemplateParameterList * 1249Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc, 1250 const CXXScopeSpec &SS, 1251 TemplateParameterList **ParamLists, 1252 unsigned NumParamLists, 1253 bool IsFriend, 1254 bool &IsExplicitSpecialization, 1255 bool &Invalid) { 1256 IsExplicitSpecialization = false; 1257 1258 // Find the template-ids that occur within the nested-name-specifier. These 1259 // template-ids will match up with the template parameter lists. 1260 llvm::SmallVector<const TemplateSpecializationType *, 4> 1261 TemplateIdsInSpecifier; 1262 llvm::SmallVector<ClassTemplateSpecializationDecl *, 4> 1263 ExplicitSpecializationsInSpecifier; 1264 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 1265 NNS; NNS = NNS->getPrefix()) { 1266 const Type *T = NNS->getAsType(); 1267 if (!T) break; 1268 1269 // C++0x [temp.expl.spec]p17: 1270 // A member or a member template may be nested within many 1271 // enclosing class templates. In an explicit specialization for 1272 // such a member, the member declaration shall be preceded by a 1273 // template<> for each enclosing class template that is 1274 // explicitly specialized. 1275 // 1276 // Following the existing practice of GNU and EDG, we allow a typedef of a 1277 // template specialization type. 1278 if (const TypedefType *TT = dyn_cast<TypedefType>(T)) 1279 T = TT->LookThroughTypedefs().getTypePtr(); 1280 1281 if (const TemplateSpecializationType *SpecType 1282 = dyn_cast<TemplateSpecializationType>(T)) { 1283 TemplateDecl *Template = SpecType->getTemplateName().getAsTemplateDecl(); 1284 if (!Template) 1285 continue; // FIXME: should this be an error? probably... 1286 1287 if (const RecordType *Record = SpecType->getAs<RecordType>()) { 1288 ClassTemplateSpecializationDecl *SpecDecl 1289 = cast<ClassTemplateSpecializationDecl>(Record->getDecl()); 1290 // If the nested name specifier refers to an explicit specialization, 1291 // we don't need a template<> header. 1292 if (SpecDecl->getSpecializationKind() == TSK_ExplicitSpecialization) { 1293 ExplicitSpecializationsInSpecifier.push_back(SpecDecl); 1294 continue; 1295 } 1296 } 1297 1298 TemplateIdsInSpecifier.push_back(SpecType); 1299 } 1300 } 1301 1302 // Reverse the list of template-ids in the scope specifier, so that we can 1303 // more easily match up the template-ids and the template parameter lists. 1304 std::reverse(TemplateIdsInSpecifier.begin(), TemplateIdsInSpecifier.end()); 1305 1306 SourceLocation FirstTemplateLoc = DeclStartLoc; 1307 if (NumParamLists) 1308 FirstTemplateLoc = ParamLists[0]->getTemplateLoc(); 1309 1310 // Match the template-ids found in the specifier to the template parameter 1311 // lists. 1312 unsigned Idx = 0; 1313 for (unsigned NumTemplateIds = TemplateIdsInSpecifier.size(); 1314 Idx != NumTemplateIds; ++Idx) { 1315 QualType TemplateId = QualType(TemplateIdsInSpecifier[Idx], 0); 1316 bool DependentTemplateId = TemplateId->isDependentType(); 1317 if (Idx >= NumParamLists) { 1318 // We have a template-id without a corresponding template parameter 1319 // list. 1320 1321 // ...which is fine if this is a friend declaration. 1322 if (IsFriend) { 1323 IsExplicitSpecialization = true; 1324 break; 1325 } 1326 1327 if (DependentTemplateId) { 1328 // FIXME: the location information here isn't great. 1329 Diag(SS.getRange().getBegin(), 1330 diag::err_template_spec_needs_template_parameters) 1331 << TemplateId 1332 << SS.getRange(); 1333 Invalid = true; 1334 } else { 1335 Diag(SS.getRange().getBegin(), diag::err_template_spec_needs_header) 1336 << SS.getRange() 1337 << FixItHint::CreateInsertion(FirstTemplateLoc, "template<> "); 1338 IsExplicitSpecialization = true; 1339 } 1340 return 0; 1341 } 1342 1343 // Check the template parameter list against its corresponding template-id. 1344 if (DependentTemplateId) { 1345 TemplateParameterList *ExpectedTemplateParams = 0; 1346 1347 // Are there cases in (e.g.) friends where this won't match? 1348 if (const InjectedClassNameType *Injected 1349 = TemplateId->getAs<InjectedClassNameType>()) { 1350 CXXRecordDecl *Record = Injected->getDecl(); 1351 if (ClassTemplatePartialSpecializationDecl *Partial = 1352 dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) 1353 ExpectedTemplateParams = Partial->getTemplateParameters(); 1354 else 1355 ExpectedTemplateParams = Record->getDescribedClassTemplate() 1356 ->getTemplateParameters(); 1357 } 1358 1359 if (ExpectedTemplateParams) 1360 TemplateParameterListsAreEqual(ParamLists[Idx], 1361 ExpectedTemplateParams, 1362 true, TPL_TemplateMatch); 1363 1364 CheckTemplateParameterList(ParamLists[Idx], 0, TPC_ClassTemplateMember); 1365 } else if (ParamLists[Idx]->size() > 0) 1366 Diag(ParamLists[Idx]->getTemplateLoc(), 1367 diag::err_template_param_list_matches_nontemplate) 1368 << TemplateId 1369 << ParamLists[Idx]->getSourceRange(); 1370 else 1371 IsExplicitSpecialization = true; 1372 } 1373 1374 // If there were at least as many template-ids as there were template 1375 // parameter lists, then there are no template parameter lists remaining for 1376 // the declaration itself. 1377 if (Idx >= NumParamLists) 1378 return 0; 1379 1380 // If there were too many template parameter lists, complain about that now. 1381 if (Idx != NumParamLists - 1) { 1382 while (Idx < NumParamLists - 1) { 1383 bool isExplicitSpecHeader = ParamLists[Idx]->size() == 0; 1384 Diag(ParamLists[Idx]->getTemplateLoc(), 1385 isExplicitSpecHeader? diag::warn_template_spec_extra_headers 1386 : diag::err_template_spec_extra_headers) 1387 << SourceRange(ParamLists[Idx]->getTemplateLoc(), 1388 ParamLists[Idx]->getRAngleLoc()); 1389 1390 if (isExplicitSpecHeader && !ExplicitSpecializationsInSpecifier.empty()) { 1391 Diag(ExplicitSpecializationsInSpecifier.back()->getLocation(), 1392 diag::note_explicit_template_spec_does_not_need_header) 1393 << ExplicitSpecializationsInSpecifier.back(); 1394 ExplicitSpecializationsInSpecifier.pop_back(); 1395 } 1396 1397 // We have a template parameter list with no corresponding scope, which 1398 // means that the resulting template declaration can't be instantiated 1399 // properly (we'll end up with dependent nodes when we shouldn't). 1400 if (!isExplicitSpecHeader) 1401 Invalid = true; 1402 1403 ++Idx; 1404 } 1405 } 1406 1407 // Return the last template parameter list, which corresponds to the 1408 // entity being declared. 1409 return ParamLists[NumParamLists - 1]; 1410} 1411 1412QualType Sema::CheckTemplateIdType(TemplateName Name, 1413 SourceLocation TemplateLoc, 1414 const TemplateArgumentListInfo &TemplateArgs) { 1415 TemplateDecl *Template = Name.getAsTemplateDecl(); 1416 if (!Template) { 1417 // The template name does not resolve to a template, so we just 1418 // build a dependent template-id type. 1419 return Context.getTemplateSpecializationType(Name, TemplateArgs); 1420 } 1421 1422 // Check that the template argument list is well-formed for this 1423 // template. 1424 TemplateArgumentListBuilder Converted(Template->getTemplateParameters(), 1425 TemplateArgs.size()); 1426 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs, 1427 false, Converted)) 1428 return QualType(); 1429 1430 assert((Converted.structuredSize() == 1431 Template->getTemplateParameters()->size()) && 1432 "Converted template argument list is too short!"); 1433 1434 QualType CanonType; 1435 1436 if (Name.isDependent() || 1437 TemplateSpecializationType::anyDependentTemplateArguments( 1438 TemplateArgs)) { 1439 // This class template specialization is a dependent 1440 // type. Therefore, its canonical type is another class template 1441 // specialization type that contains all of the converted 1442 // arguments in canonical form. This ensures that, e.g., A<T> and 1443 // A<T, T> have identical types when A is declared as: 1444 // 1445 // template<typename T, typename U = T> struct A; 1446 TemplateName CanonName = Context.getCanonicalTemplateName(Name); 1447 CanonType = Context.getTemplateSpecializationType(CanonName, 1448 Converted.getFlatArguments(), 1449 Converted.flatSize()); 1450 1451 // FIXME: CanonType is not actually the canonical type, and unfortunately 1452 // it is a TemplateSpecializationType that we will never use again. 1453 // In the future, we need to teach getTemplateSpecializationType to only 1454 // build the canonical type and return that to us. 1455 CanonType = Context.getCanonicalType(CanonType); 1456 1457 // This might work out to be a current instantiation, in which 1458 // case the canonical type needs to be the InjectedClassNameType. 1459 // 1460 // TODO: in theory this could be a simple hashtable lookup; most 1461 // changes to CurContext don't change the set of current 1462 // instantiations. 1463 if (isa<ClassTemplateDecl>(Template)) { 1464 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { 1465 // If we get out to a namespace, we're done. 1466 if (Ctx->isFileContext()) break; 1467 1468 // If this isn't a record, keep looking. 1469 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx); 1470 if (!Record) continue; 1471 1472 // Look for one of the two cases with InjectedClassNameTypes 1473 // and check whether it's the same template. 1474 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) && 1475 !Record->getDescribedClassTemplate()) 1476 continue; 1477 1478 // Fetch the injected class name type and check whether its 1479 // injected type is equal to the type we just built. 1480 QualType ICNT = Context.getTypeDeclType(Record); 1481 QualType Injected = cast<InjectedClassNameType>(ICNT) 1482 ->getInjectedSpecializationType(); 1483 1484 if (CanonType != Injected->getCanonicalTypeInternal()) 1485 continue; 1486 1487 // If so, the canonical type of this TST is the injected 1488 // class name type of the record we just found. 1489 assert(ICNT.isCanonical()); 1490 CanonType = ICNT; 1491 break; 1492 } 1493 } 1494 } else if (ClassTemplateDecl *ClassTemplate 1495 = dyn_cast<ClassTemplateDecl>(Template)) { 1496 // Find the class template specialization declaration that 1497 // corresponds to these arguments. 1498 void *InsertPos = 0; 1499 ClassTemplateSpecializationDecl *Decl 1500 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 1501 Converted.flatSize(), InsertPos); 1502 if (!Decl) { 1503 // This is the first time we have referenced this class template 1504 // specialization. Create the canonical declaration and add it to 1505 // the set of specializations. 1506 Decl = ClassTemplateSpecializationDecl::Create(Context, 1507 ClassTemplate->getTemplatedDecl()->getTagKind(), 1508 ClassTemplate->getDeclContext(), 1509 ClassTemplate->getLocation(), 1510 ClassTemplate, 1511 Converted, 0); 1512 ClassTemplate->AddSpecialization(Decl, InsertPos); 1513 Decl->setLexicalDeclContext(CurContext); 1514 } 1515 1516 CanonType = Context.getTypeDeclType(Decl); 1517 assert(isa<RecordType>(CanonType) && 1518 "type of non-dependent specialization is not a RecordType"); 1519 } 1520 1521 // Build the fully-sugared type for this class template 1522 // specialization, which refers back to the class template 1523 // specialization we created or found. 1524 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType); 1525} 1526 1527TypeResult 1528Sema::ActOnTemplateIdType(TemplateTy TemplateD, SourceLocation TemplateLoc, 1529 SourceLocation LAngleLoc, 1530 ASTTemplateArgsPtr TemplateArgsIn, 1531 SourceLocation RAngleLoc) { 1532 TemplateName Template = TemplateD.getAsVal<TemplateName>(); 1533 1534 // Translate the parser's template argument list in our AST format. 1535 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 1536 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 1537 1538 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); 1539 TemplateArgsIn.release(); 1540 1541 if (Result.isNull()) 1542 return true; 1543 1544 TypeSourceInfo *DI = Context.CreateTypeSourceInfo(Result); 1545 TemplateSpecializationTypeLoc TL 1546 = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc()); 1547 TL.setTemplateNameLoc(TemplateLoc); 1548 TL.setLAngleLoc(LAngleLoc); 1549 TL.setRAngleLoc(RAngleLoc); 1550 for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i) 1551 TL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 1552 1553 return CreateParsedType(Result, DI); 1554} 1555 1556TypeResult Sema::ActOnTagTemplateIdType(TypeResult TypeResult, 1557 TagUseKind TUK, 1558 TypeSpecifierType TagSpec, 1559 SourceLocation TagLoc) { 1560 if (TypeResult.isInvalid()) 1561 return ::TypeResult(); 1562 1563 // FIXME: preserve source info, ideally without copying the DI. 1564 TypeSourceInfo *DI; 1565 QualType Type = GetTypeFromParser(TypeResult.get(), &DI); 1566 1567 // Verify the tag specifier. 1568 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 1569 1570 if (const RecordType *RT = Type->getAs<RecordType>()) { 1571 RecordDecl *D = RT->getDecl(); 1572 1573 IdentifierInfo *Id = D->getIdentifier(); 1574 assert(Id && "templated class must have an identifier"); 1575 1576 if (!isAcceptableTagRedeclaration(D, TagKind, TagLoc, *Id)) { 1577 Diag(TagLoc, diag::err_use_with_wrong_tag) 1578 << Type 1579 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName()); 1580 Diag(D->getLocation(), diag::note_previous_use); 1581 } 1582 } 1583 1584 ElaboratedTypeKeyword Keyword 1585 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind); 1586 QualType ElabType = Context.getElaboratedType(Keyword, /*NNS=*/0, Type); 1587 1588 return ParsedType::make(ElabType); 1589} 1590 1591ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, 1592 LookupResult &R, 1593 bool RequiresADL, 1594 const TemplateArgumentListInfo &TemplateArgs) { 1595 // FIXME: Can we do any checking at this point? I guess we could check the 1596 // template arguments that we have against the template name, if the template 1597 // name refers to a single template. That's not a terribly common case, 1598 // though. 1599 1600 // These should be filtered out by our callers. 1601 assert(!R.empty() && "empty lookup results when building templateid"); 1602 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid"); 1603 1604 NestedNameSpecifier *Qualifier = 0; 1605 SourceRange QualifierRange; 1606 if (SS.isSet()) { 1607 Qualifier = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 1608 QualifierRange = SS.getRange(); 1609 } 1610 1611 // We don't want lookup warnings at this point. 1612 R.suppressDiagnostics(); 1613 1614 bool Dependent 1615 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 1616 &TemplateArgs); 1617 UnresolvedLookupExpr *ULE 1618 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1619 Qualifier, QualifierRange, 1620 R.getLookupNameInfo(), 1621 RequiresADL, TemplateArgs, 1622 R.begin(), R.end()); 1623 1624 return Owned(ULE); 1625} 1626 1627// We actually only call this from template instantiation. 1628ExprResult 1629Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, 1630 const DeclarationNameInfo &NameInfo, 1631 const TemplateArgumentListInfo &TemplateArgs) { 1632 DeclContext *DC; 1633 if (!(DC = computeDeclContext(SS, false)) || 1634 DC->isDependentContext() || 1635 RequireCompleteDeclContext(SS, DC)) 1636 return BuildDependentDeclRefExpr(SS, NameInfo, &TemplateArgs); 1637 1638 bool MemberOfUnknownSpecialization; 1639 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1640 LookupTemplateName(R, (Scope*) 0, SS, QualType(), /*Entering*/ false, 1641 MemberOfUnknownSpecialization); 1642 1643 if (R.isAmbiguous()) 1644 return ExprError(); 1645 1646 if (R.empty()) { 1647 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template) 1648 << NameInfo.getName() << SS.getRange(); 1649 return ExprError(); 1650 } 1651 1652 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) { 1653 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template) 1654 << (NestedNameSpecifier*) SS.getScopeRep() 1655 << NameInfo.getName() << SS.getRange(); 1656 Diag(Temp->getLocation(), diag::note_referenced_class_template); 1657 return ExprError(); 1658 } 1659 1660 return BuildTemplateIdExpr(SS, R, /* ADL */ false, TemplateArgs); 1661} 1662 1663/// \brief Form a dependent template name. 1664/// 1665/// This action forms a dependent template name given the template 1666/// name and its (presumably dependent) scope specifier. For 1667/// example, given "MetaFun::template apply", the scope specifier \p 1668/// SS will be "MetaFun::", \p TemplateKWLoc contains the location 1669/// of the "template" keyword, and "apply" is the \p Name. 1670TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S, 1671 SourceLocation TemplateKWLoc, 1672 CXXScopeSpec &SS, 1673 UnqualifiedId &Name, 1674 ParsedType ObjectType, 1675 bool EnteringContext, 1676 TemplateTy &Result) { 1677 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent() && 1678 !getLangOptions().CPlusPlus0x) 1679 Diag(TemplateKWLoc, diag::ext_template_outside_of_template) 1680 << FixItHint::CreateRemoval(TemplateKWLoc); 1681 1682 DeclContext *LookupCtx = 0; 1683 if (SS.isSet()) 1684 LookupCtx = computeDeclContext(SS, EnteringContext); 1685 if (!LookupCtx && ObjectType) 1686 LookupCtx = computeDeclContext(ObjectType.get()); 1687 if (LookupCtx) { 1688 // C++0x [temp.names]p5: 1689 // If a name prefixed by the keyword template is not the name of 1690 // a template, the program is ill-formed. [Note: the keyword 1691 // template may not be applied to non-template members of class 1692 // templates. -end note ] [ Note: as is the case with the 1693 // typename prefix, the template prefix is allowed in cases 1694 // where it is not strictly necessary; i.e., when the 1695 // nested-name-specifier or the expression on the left of the -> 1696 // or . is not dependent on a template-parameter, or the use 1697 // does not appear in the scope of a template. -end note] 1698 // 1699 // Note: C++03 was more strict here, because it banned the use of 1700 // the "template" keyword prior to a template-name that was not a 1701 // dependent name. C++ DR468 relaxed this requirement (the 1702 // "template" keyword is now permitted). We follow the C++0x 1703 // rules, even in C++03 mode with a warning, retroactively applying the DR. 1704 bool MemberOfUnknownSpecialization; 1705 TemplateNameKind TNK = isTemplateName(0, SS, TemplateKWLoc.isValid(), Name, 1706 ObjectType, EnteringContext, Result, 1707 MemberOfUnknownSpecialization); 1708 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() && 1709 isa<CXXRecordDecl>(LookupCtx) && 1710 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()) { 1711 // This is a dependent template. Handle it below. 1712 } else if (TNK == TNK_Non_template) { 1713 Diag(Name.getSourceRange().getBegin(), 1714 diag::err_template_kw_refers_to_non_template) 1715 << GetNameFromUnqualifiedId(Name).getName() 1716 << Name.getSourceRange() 1717 << TemplateKWLoc; 1718 return TNK_Non_template; 1719 } else { 1720 // We found something; return it. 1721 return TNK; 1722 } 1723 } 1724 1725 NestedNameSpecifier *Qualifier 1726 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 1727 1728 switch (Name.getKind()) { 1729 case UnqualifiedId::IK_Identifier: 1730 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1731 Name.Identifier)); 1732 return TNK_Dependent_template_name; 1733 1734 case UnqualifiedId::IK_OperatorFunctionId: 1735 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1736 Name.OperatorFunctionId.Operator)); 1737 return TNK_Dependent_template_name; 1738 1739 case UnqualifiedId::IK_LiteralOperatorId: 1740 assert(false && "We don't support these; Parse shouldn't have allowed propagation"); 1741 1742 default: 1743 break; 1744 } 1745 1746 Diag(Name.getSourceRange().getBegin(), 1747 diag::err_template_kw_refers_to_non_template) 1748 << GetNameFromUnqualifiedId(Name).getName() 1749 << Name.getSourceRange() 1750 << TemplateKWLoc; 1751 return TNK_Non_template; 1752} 1753 1754bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, 1755 const TemplateArgumentLoc &AL, 1756 TemplateArgumentListBuilder &Converted) { 1757 const TemplateArgument &Arg = AL.getArgument(); 1758 1759 // Check template type parameter. 1760 switch(Arg.getKind()) { 1761 case TemplateArgument::Type: 1762 // C++ [temp.arg.type]p1: 1763 // A template-argument for a template-parameter which is a 1764 // type shall be a type-id. 1765 break; 1766 case TemplateArgument::Template: { 1767 // We have a template type parameter but the template argument 1768 // is a template without any arguments. 1769 SourceRange SR = AL.getSourceRange(); 1770 TemplateName Name = Arg.getAsTemplate(); 1771 Diag(SR.getBegin(), diag::err_template_missing_args) 1772 << Name << SR; 1773 if (TemplateDecl *Decl = Name.getAsTemplateDecl()) 1774 Diag(Decl->getLocation(), diag::note_template_decl_here); 1775 1776 return true; 1777 } 1778 default: { 1779 // We have a template type parameter but the template argument 1780 // is not a type. 1781 SourceRange SR = AL.getSourceRange(); 1782 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; 1783 Diag(Param->getLocation(), diag::note_template_param_here); 1784 1785 return true; 1786 } 1787 } 1788 1789 if (CheckTemplateArgument(Param, AL.getTypeSourceInfo())) 1790 return true; 1791 1792 // Add the converted template type argument. 1793 Converted.Append( 1794 TemplateArgument(Context.getCanonicalType(Arg.getAsType()))); 1795 return false; 1796} 1797 1798/// \brief Substitute template arguments into the default template argument for 1799/// the given template type parameter. 1800/// 1801/// \param SemaRef the semantic analysis object for which we are performing 1802/// the substitution. 1803/// 1804/// \param Template the template that we are synthesizing template arguments 1805/// for. 1806/// 1807/// \param TemplateLoc the location of the template name that started the 1808/// template-id we are checking. 1809/// 1810/// \param RAngleLoc the location of the right angle bracket ('>') that 1811/// terminates the template-id. 1812/// 1813/// \param Param the template template parameter whose default we are 1814/// substituting into. 1815/// 1816/// \param Converted the list of template arguments provided for template 1817/// parameters that precede \p Param in the template parameter list. 1818/// 1819/// \returns the substituted template argument, or NULL if an error occurred. 1820static TypeSourceInfo * 1821SubstDefaultTemplateArgument(Sema &SemaRef, 1822 TemplateDecl *Template, 1823 SourceLocation TemplateLoc, 1824 SourceLocation RAngleLoc, 1825 TemplateTypeParmDecl *Param, 1826 TemplateArgumentListBuilder &Converted) { 1827 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo(); 1828 1829 // If the argument type is dependent, instantiate it now based 1830 // on the previously-computed template arguments. 1831 if (ArgType->getType()->isDependentType()) { 1832 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1833 /*TakeArgs=*/false); 1834 1835 MultiLevelTemplateArgumentList AllTemplateArgs 1836 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1837 1838 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1839 Template, Converted.getFlatArguments(), 1840 Converted.flatSize(), 1841 SourceRange(TemplateLoc, RAngleLoc)); 1842 1843 ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs, 1844 Param->getDefaultArgumentLoc(), 1845 Param->getDeclName()); 1846 } 1847 1848 return ArgType; 1849} 1850 1851/// \brief Substitute template arguments into the default template argument for 1852/// the given non-type template parameter. 1853/// 1854/// \param SemaRef the semantic analysis object for which we are performing 1855/// the substitution. 1856/// 1857/// \param Template the template that we are synthesizing template arguments 1858/// for. 1859/// 1860/// \param TemplateLoc the location of the template name that started the 1861/// template-id we are checking. 1862/// 1863/// \param RAngleLoc the location of the right angle bracket ('>') that 1864/// terminates the template-id. 1865/// 1866/// \param Param the non-type template parameter whose default we are 1867/// substituting into. 1868/// 1869/// \param Converted the list of template arguments provided for template 1870/// parameters that precede \p Param in the template parameter list. 1871/// 1872/// \returns the substituted template argument, or NULL if an error occurred. 1873static ExprResult 1874SubstDefaultTemplateArgument(Sema &SemaRef, 1875 TemplateDecl *Template, 1876 SourceLocation TemplateLoc, 1877 SourceLocation RAngleLoc, 1878 NonTypeTemplateParmDecl *Param, 1879 TemplateArgumentListBuilder &Converted) { 1880 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1881 /*TakeArgs=*/false); 1882 1883 MultiLevelTemplateArgumentList AllTemplateArgs 1884 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1885 1886 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1887 Template, Converted.getFlatArguments(), 1888 Converted.flatSize(), 1889 SourceRange(TemplateLoc, RAngleLoc)); 1890 1891 return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs); 1892} 1893 1894/// \brief Substitute template arguments into the default template argument for 1895/// the given template template parameter. 1896/// 1897/// \param SemaRef the semantic analysis object for which we are performing 1898/// the substitution. 1899/// 1900/// \param Template the template that we are synthesizing template arguments 1901/// for. 1902/// 1903/// \param TemplateLoc the location of the template name that started the 1904/// template-id we are checking. 1905/// 1906/// \param RAngleLoc the location of the right angle bracket ('>') that 1907/// terminates the template-id. 1908/// 1909/// \param Param the template template parameter whose default we are 1910/// substituting into. 1911/// 1912/// \param Converted the list of template arguments provided for template 1913/// parameters that precede \p Param in the template parameter list. 1914/// 1915/// \returns the substituted template argument, or NULL if an error occurred. 1916static TemplateName 1917SubstDefaultTemplateArgument(Sema &SemaRef, 1918 TemplateDecl *Template, 1919 SourceLocation TemplateLoc, 1920 SourceLocation RAngleLoc, 1921 TemplateTemplateParmDecl *Param, 1922 TemplateArgumentListBuilder &Converted) { 1923 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1924 /*TakeArgs=*/false); 1925 1926 MultiLevelTemplateArgumentList AllTemplateArgs 1927 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1928 1929 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1930 Template, Converted.getFlatArguments(), 1931 Converted.flatSize(), 1932 SourceRange(TemplateLoc, RAngleLoc)); 1933 1934 return SemaRef.SubstTemplateName( 1935 Param->getDefaultArgument().getArgument().getAsTemplate(), 1936 Param->getDefaultArgument().getTemplateNameLoc(), 1937 AllTemplateArgs); 1938} 1939 1940/// \brief If the given template parameter has a default template 1941/// argument, substitute into that default template argument and 1942/// return the corresponding template argument. 1943TemplateArgumentLoc 1944Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template, 1945 SourceLocation TemplateLoc, 1946 SourceLocation RAngleLoc, 1947 Decl *Param, 1948 TemplateArgumentListBuilder &Converted) { 1949 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) { 1950 if (!TypeParm->hasDefaultArgument()) 1951 return TemplateArgumentLoc(); 1952 1953 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template, 1954 TemplateLoc, 1955 RAngleLoc, 1956 TypeParm, 1957 Converted); 1958 if (DI) 1959 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI); 1960 1961 return TemplateArgumentLoc(); 1962 } 1963 1964 if (NonTypeTemplateParmDecl *NonTypeParm 1965 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 1966 if (!NonTypeParm->hasDefaultArgument()) 1967 return TemplateArgumentLoc(); 1968 1969 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template, 1970 TemplateLoc, 1971 RAngleLoc, 1972 NonTypeParm, 1973 Converted); 1974 if (Arg.isInvalid()) 1975 return TemplateArgumentLoc(); 1976 1977 Expr *ArgE = Arg.takeAs<Expr>(); 1978 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE); 1979 } 1980 1981 TemplateTemplateParmDecl *TempTempParm 1982 = cast<TemplateTemplateParmDecl>(Param); 1983 if (!TempTempParm->hasDefaultArgument()) 1984 return TemplateArgumentLoc(); 1985 1986 TemplateName TName = SubstDefaultTemplateArgument(*this, Template, 1987 TemplateLoc, 1988 RAngleLoc, 1989 TempTempParm, 1990 Converted); 1991 if (TName.isNull()) 1992 return TemplateArgumentLoc(); 1993 1994 return TemplateArgumentLoc(TemplateArgument(TName), 1995 TempTempParm->getDefaultArgument().getTemplateQualifierRange(), 1996 TempTempParm->getDefaultArgument().getTemplateNameLoc()); 1997} 1998 1999/// \brief Check that the given template argument corresponds to the given 2000/// template parameter. 2001bool Sema::CheckTemplateArgument(NamedDecl *Param, 2002 const TemplateArgumentLoc &Arg, 2003 TemplateDecl *Template, 2004 SourceLocation TemplateLoc, 2005 SourceLocation RAngleLoc, 2006 TemplateArgumentListBuilder &Converted, 2007 CheckTemplateArgumentKind CTAK) { 2008 // Check template type parameters. 2009 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) 2010 return CheckTemplateTypeArgument(TTP, Arg, Converted); 2011 2012 // Check non-type template parameters. 2013 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2014 // Do substitution on the type of the non-type template parameter 2015 // with the template arguments we've seen thus far. 2016 QualType NTTPType = NTTP->getType(); 2017 if (NTTPType->isDependentType()) { 2018 // Do substitution on the type of the non-type template parameter. 2019 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2020 NTTP, Converted.getFlatArguments(), 2021 Converted.flatSize(), 2022 SourceRange(TemplateLoc, RAngleLoc)); 2023 2024 TemplateArgumentList TemplateArgs(Context, Converted, 2025 /*TakeArgs=*/false); 2026 NTTPType = SubstType(NTTPType, 2027 MultiLevelTemplateArgumentList(TemplateArgs), 2028 NTTP->getLocation(), 2029 NTTP->getDeclName()); 2030 // If that worked, check the non-type template parameter type 2031 // for validity. 2032 if (!NTTPType.isNull()) 2033 NTTPType = CheckNonTypeTemplateParameterType(NTTPType, 2034 NTTP->getLocation()); 2035 if (NTTPType.isNull()) 2036 return true; 2037 } 2038 2039 switch (Arg.getArgument().getKind()) { 2040 case TemplateArgument::Null: 2041 assert(false && "Should never see a NULL template argument here"); 2042 return true; 2043 2044 case TemplateArgument::Expression: { 2045 Expr *E = Arg.getArgument().getAsExpr(); 2046 TemplateArgument Result; 2047 if (CheckTemplateArgument(NTTP, NTTPType, E, Result, CTAK)) 2048 return true; 2049 2050 Converted.Append(Result); 2051 break; 2052 } 2053 2054 case TemplateArgument::Declaration: 2055 case TemplateArgument::Integral: 2056 // We've already checked this template argument, so just copy 2057 // it to the list of converted arguments. 2058 Converted.Append(Arg.getArgument()); 2059 break; 2060 2061 case TemplateArgument::Template: 2062 // We were given a template template argument. It may not be ill-formed; 2063 // see below. 2064 if (DependentTemplateName *DTN 2065 = Arg.getArgument().getAsTemplate().getAsDependentTemplateName()) { 2066 // We have a template argument such as \c T::template X, which we 2067 // parsed as a template template argument. However, since we now 2068 // know that we need a non-type template argument, convert this 2069 // template name into an expression. 2070 2071 DeclarationNameInfo NameInfo(DTN->getIdentifier(), 2072 Arg.getTemplateNameLoc()); 2073 2074 Expr *E = DependentScopeDeclRefExpr::Create(Context, 2075 DTN->getQualifier(), 2076 Arg.getTemplateQualifierRange(), 2077 NameInfo); 2078 2079 TemplateArgument Result; 2080 if (CheckTemplateArgument(NTTP, NTTPType, E, Result)) 2081 return true; 2082 2083 Converted.Append(Result); 2084 break; 2085 } 2086 2087 // We have a template argument that actually does refer to a class 2088 // template, template alias, or template template parameter, and 2089 // therefore cannot be a non-type template argument. 2090 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) 2091 << Arg.getSourceRange(); 2092 2093 Diag(Param->getLocation(), diag::note_template_param_here); 2094 return true; 2095 2096 case TemplateArgument::Type: { 2097 // We have a non-type template parameter but the template 2098 // argument is a type. 2099 2100 // C++ [temp.arg]p2: 2101 // In a template-argument, an ambiguity between a type-id and 2102 // an expression is resolved to a type-id, regardless of the 2103 // form of the corresponding template-parameter. 2104 // 2105 // We warn specifically about this case, since it can be rather 2106 // confusing for users. 2107 QualType T = Arg.getArgument().getAsType(); 2108 SourceRange SR = Arg.getSourceRange(); 2109 if (T->isFunctionType()) 2110 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; 2111 else 2112 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; 2113 Diag(Param->getLocation(), diag::note_template_param_here); 2114 return true; 2115 } 2116 2117 case TemplateArgument::Pack: 2118 llvm_unreachable("Caller must expand template argument packs"); 2119 break; 2120 } 2121 2122 return false; 2123 } 2124 2125 2126 // Check template template parameters. 2127 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param); 2128 2129 // Substitute into the template parameter list of the template 2130 // template parameter, since previously-supplied template arguments 2131 // may appear within the template template parameter. 2132 { 2133 // Set up a template instantiation context. 2134 LocalInstantiationScope Scope(*this); 2135 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2136 TempParm, Converted.getFlatArguments(), 2137 Converted.flatSize(), 2138 SourceRange(TemplateLoc, RAngleLoc)); 2139 2140 TemplateArgumentList TemplateArgs(Context, Converted, 2141 /*TakeArgs=*/false); 2142 TempParm = cast_or_null<TemplateTemplateParmDecl>( 2143 SubstDecl(TempParm, CurContext, 2144 MultiLevelTemplateArgumentList(TemplateArgs))); 2145 if (!TempParm) 2146 return true; 2147 2148 // FIXME: TempParam is leaked. 2149 } 2150 2151 switch (Arg.getArgument().getKind()) { 2152 case TemplateArgument::Null: 2153 assert(false && "Should never see a NULL template argument here"); 2154 return true; 2155 2156 case TemplateArgument::Template: 2157 if (CheckTemplateArgument(TempParm, Arg)) 2158 return true; 2159 2160 Converted.Append(Arg.getArgument()); 2161 break; 2162 2163 case TemplateArgument::Expression: 2164 case TemplateArgument::Type: 2165 // We have a template template parameter but the template 2166 // argument does not refer to a template. 2167 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template); 2168 return true; 2169 2170 case TemplateArgument::Declaration: 2171 llvm_unreachable( 2172 "Declaration argument with template template parameter"); 2173 break; 2174 case TemplateArgument::Integral: 2175 llvm_unreachable( 2176 "Integral argument with template template parameter"); 2177 break; 2178 2179 case TemplateArgument::Pack: 2180 llvm_unreachable("Caller must expand template argument packs"); 2181 break; 2182 } 2183 2184 return false; 2185} 2186 2187/// \brief Check that the given template argument list is well-formed 2188/// for specializing the given template. 2189bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, 2190 SourceLocation TemplateLoc, 2191 const TemplateArgumentListInfo &TemplateArgs, 2192 bool PartialTemplateArgs, 2193 TemplateArgumentListBuilder &Converted) { 2194 TemplateParameterList *Params = Template->getTemplateParameters(); 2195 unsigned NumParams = Params->size(); 2196 unsigned NumArgs = TemplateArgs.size(); 2197 bool Invalid = false; 2198 2199 SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc(); 2200 2201 bool HasParameterPack = 2202 NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack(); 2203 2204 if ((NumArgs > NumParams && !HasParameterPack) || 2205 (NumArgs < Params->getMinRequiredArguments() && 2206 !PartialTemplateArgs)) { 2207 // FIXME: point at either the first arg beyond what we can handle, 2208 // or the '>', depending on whether we have too many or too few 2209 // arguments. 2210 SourceRange Range; 2211 if (NumArgs > NumParams) 2212 Range = SourceRange(TemplateArgs[NumParams].getLocation(), RAngleLoc); 2213 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 2214 << (NumArgs > NumParams) 2215 << (isa<ClassTemplateDecl>(Template)? 0 : 2216 isa<FunctionTemplateDecl>(Template)? 1 : 2217 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 2218 << Template << Range; 2219 Diag(Template->getLocation(), diag::note_template_decl_here) 2220 << Params->getSourceRange(); 2221 Invalid = true; 2222 } 2223 2224 // C++ [temp.arg]p1: 2225 // [...] The type and form of each template-argument specified in 2226 // a template-id shall match the type and form specified for the 2227 // corresponding parameter declared by the template in its 2228 // template-parameter-list. 2229 unsigned ArgIdx = 0; 2230 for (TemplateParameterList::iterator Param = Params->begin(), 2231 ParamEnd = Params->end(); 2232 Param != ParamEnd; ++Param, ++ArgIdx) { 2233 if (ArgIdx > NumArgs && PartialTemplateArgs) 2234 break; 2235 2236 // If we have a template parameter pack, check every remaining template 2237 // argument against that template parameter pack. 2238 if ((*Param)->isTemplateParameterPack()) { 2239 Converted.BeginPack(); 2240 for (; ArgIdx < NumArgs; ++ArgIdx) { 2241 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 2242 TemplateLoc, RAngleLoc, Converted)) { 2243 Invalid = true; 2244 break; 2245 } 2246 } 2247 Converted.EndPack(); 2248 continue; 2249 } 2250 2251 if (ArgIdx < NumArgs) { 2252 // Check the template argument we were given. 2253 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 2254 TemplateLoc, RAngleLoc, Converted)) 2255 return true; 2256 2257 continue; 2258 } 2259 2260 // We have a default template argument that we will use. 2261 TemplateArgumentLoc Arg; 2262 2263 // Retrieve the default template argument from the template 2264 // parameter. For each kind of template parameter, we substitute the 2265 // template arguments provided thus far and any "outer" template arguments 2266 // (when the template parameter was part of a nested template) into 2267 // the default argument. 2268 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) { 2269 if (!TTP->hasDefaultArgument()) { 2270 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2271 break; 2272 } 2273 2274 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this, 2275 Template, 2276 TemplateLoc, 2277 RAngleLoc, 2278 TTP, 2279 Converted); 2280 if (!ArgType) 2281 return true; 2282 2283 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), 2284 ArgType); 2285 } else if (NonTypeTemplateParmDecl *NTTP 2286 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 2287 if (!NTTP->hasDefaultArgument()) { 2288 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2289 break; 2290 } 2291 2292 ExprResult E = SubstDefaultTemplateArgument(*this, Template, 2293 TemplateLoc, 2294 RAngleLoc, 2295 NTTP, 2296 Converted); 2297 if (E.isInvalid()) 2298 return true; 2299 2300 Expr *Ex = E.takeAs<Expr>(); 2301 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); 2302 } else { 2303 TemplateTemplateParmDecl *TempParm 2304 = cast<TemplateTemplateParmDecl>(*Param); 2305 2306 if (!TempParm->hasDefaultArgument()) { 2307 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2308 break; 2309 } 2310 2311 TemplateName Name = SubstDefaultTemplateArgument(*this, Template, 2312 TemplateLoc, 2313 RAngleLoc, 2314 TempParm, 2315 Converted); 2316 if (Name.isNull()) 2317 return true; 2318 2319 Arg = TemplateArgumentLoc(TemplateArgument(Name), 2320 TempParm->getDefaultArgument().getTemplateQualifierRange(), 2321 TempParm->getDefaultArgument().getTemplateNameLoc()); 2322 } 2323 2324 // Introduce an instantiation record that describes where we are using 2325 // the default template argument. 2326 InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param, 2327 Converted.getFlatArguments(), 2328 Converted.flatSize(), 2329 SourceRange(TemplateLoc, RAngleLoc)); 2330 2331 // Check the default template argument. 2332 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, 2333 RAngleLoc, Converted)) 2334 return true; 2335 } 2336 2337 return Invalid; 2338} 2339 2340/// \brief Check a template argument against its corresponding 2341/// template type parameter. 2342/// 2343/// This routine implements the semantics of C++ [temp.arg.type]. It 2344/// returns true if an error occurred, and false otherwise. 2345bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, 2346 TypeSourceInfo *ArgInfo) { 2347 assert(ArgInfo && "invalid TypeSourceInfo"); 2348 QualType Arg = ArgInfo->getType(); 2349 2350 // C++03 [temp.arg.type]p2: 2351 // A local type, a type with no linkage, an unnamed type or a type 2352 // compounded from any of these types shall not be used as a 2353 // template-argument for a template type-parameter. 2354 // C++0x allows these, and even in C++03 we allow them as an extension with 2355 // a warning. 2356 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 2357 if (!LangOpts.CPlusPlus0x) { 2358 const TagType *Tag = 0; 2359 if (const EnumType *EnumT = Arg->getAs<EnumType>()) 2360 Tag = EnumT; 2361 else if (const RecordType *RecordT = Arg->getAs<RecordType>()) 2362 Tag = RecordT; 2363 if (Tag && Tag->getDecl()->getDeclContext()->isFunctionOrMethod()) { 2364 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 2365 Diag(SR.getBegin(), diag::ext_template_arg_local_type) 2366 << QualType(Tag, 0) << SR; 2367 } else if (Tag && !Tag->getDecl()->getDeclName() && 2368 !Tag->getDecl()->getTypedefForAnonDecl()) { 2369 Diag(SR.getBegin(), diag::ext_template_arg_unnamed_type) << SR; 2370 Diag(Tag->getDecl()->getLocation(), 2371 diag::note_template_unnamed_type_here); 2372 } 2373 } 2374 2375 if (Arg->isVariablyModifiedType()) { 2376 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg; 2377 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) { 2378 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR; 2379 } 2380 2381 return false; 2382} 2383 2384/// \brief Checks whether the given template argument is the address 2385/// of an object or function according to C++ [temp.arg.nontype]p1. 2386static bool 2387CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S, 2388 NonTypeTemplateParmDecl *Param, 2389 QualType ParamType, 2390 Expr *ArgIn, 2391 TemplateArgument &Converted) { 2392 bool Invalid = false; 2393 Expr *Arg = ArgIn; 2394 QualType ArgType = Arg->getType(); 2395 2396 // See through any implicit casts we added to fix the type. 2397 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2398 Arg = Cast->getSubExpr(); 2399 2400 // C++ [temp.arg.nontype]p1: 2401 // 2402 // A template-argument for a non-type, non-template 2403 // template-parameter shall be one of: [...] 2404 // 2405 // -- the address of an object or function with external 2406 // linkage, including function templates and function 2407 // template-ids but excluding non-static class members, 2408 // expressed as & id-expression where the & is optional if 2409 // the name refers to a function or array, or if the 2410 // corresponding template-parameter is a reference; or 2411 DeclRefExpr *DRE = 0; 2412 2413 // Ignore (and complain about) any excess parentheses. 2414 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2415 if (!Invalid) { 2416 S.Diag(Arg->getSourceRange().getBegin(), 2417 diag::err_template_arg_extra_parens) 2418 << Arg->getSourceRange(); 2419 Invalid = true; 2420 } 2421 2422 Arg = Parens->getSubExpr(); 2423 } 2424 2425 bool AddressTaken = false; 2426 SourceLocation AddrOpLoc; 2427 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2428 if (UnOp->getOpcode() == UO_AddrOf) { 2429 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2430 AddressTaken = true; 2431 AddrOpLoc = UnOp->getOperatorLoc(); 2432 } 2433 } else 2434 DRE = dyn_cast<DeclRefExpr>(Arg); 2435 2436 if (!DRE) { 2437 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 2438 << Arg->getSourceRange(); 2439 S.Diag(Param->getLocation(), diag::note_template_param_here); 2440 return true; 2441 } 2442 2443 // Stop checking the precise nature of the argument if it is value dependent, 2444 // it should be checked when instantiated. 2445 if (Arg->isValueDependent()) { 2446 Converted = TemplateArgument(ArgIn->Retain()); 2447 return false; 2448 } 2449 2450 if (!isa<ValueDecl>(DRE->getDecl())) { 2451 S.Diag(Arg->getSourceRange().getBegin(), 2452 diag::err_template_arg_not_object_or_func_form) 2453 << Arg->getSourceRange(); 2454 S.Diag(Param->getLocation(), diag::note_template_param_here); 2455 return true; 2456 } 2457 2458 NamedDecl *Entity = 0; 2459 2460 // Cannot refer to non-static data members 2461 if (FieldDecl *Field = dyn_cast<FieldDecl>(DRE->getDecl())) { 2462 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_field) 2463 << Field << Arg->getSourceRange(); 2464 S.Diag(Param->getLocation(), diag::note_template_param_here); 2465 return true; 2466 } 2467 2468 // Cannot refer to non-static member functions 2469 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(DRE->getDecl())) 2470 if (!Method->isStatic()) { 2471 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_method) 2472 << Method << Arg->getSourceRange(); 2473 S.Diag(Param->getLocation(), diag::note_template_param_here); 2474 return true; 2475 } 2476 2477 // Functions must have external linkage. 2478 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(DRE->getDecl())) { 2479 if (!isExternalLinkage(Func->getLinkage())) { 2480 S.Diag(Arg->getSourceRange().getBegin(), 2481 diag::err_template_arg_function_not_extern) 2482 << Func << Arg->getSourceRange(); 2483 S.Diag(Func->getLocation(), diag::note_template_arg_internal_object) 2484 << true; 2485 return true; 2486 } 2487 2488 // Okay: we've named a function with external linkage. 2489 Entity = Func; 2490 2491 // If the template parameter has pointer type, the function decays. 2492 if (ParamType->isPointerType() && !AddressTaken) 2493 ArgType = S.Context.getPointerType(Func->getType()); 2494 else if (AddressTaken && ParamType->isReferenceType()) { 2495 // If we originally had an address-of operator, but the 2496 // parameter has reference type, complain and (if things look 2497 // like they will work) drop the address-of operator. 2498 if (!S.Context.hasSameUnqualifiedType(Func->getType(), 2499 ParamType.getNonReferenceType())) { 2500 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2501 << ParamType; 2502 S.Diag(Param->getLocation(), diag::note_template_param_here); 2503 return true; 2504 } 2505 2506 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2507 << ParamType 2508 << FixItHint::CreateRemoval(AddrOpLoc); 2509 S.Diag(Param->getLocation(), diag::note_template_param_here); 2510 2511 ArgType = Func->getType(); 2512 } 2513 } else if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 2514 if (!isExternalLinkage(Var->getLinkage())) { 2515 S.Diag(Arg->getSourceRange().getBegin(), 2516 diag::err_template_arg_object_not_extern) 2517 << Var << Arg->getSourceRange(); 2518 S.Diag(Var->getLocation(), diag::note_template_arg_internal_object) 2519 << true; 2520 return true; 2521 } 2522 2523 // A value of reference type is not an object. 2524 if (Var->getType()->isReferenceType()) { 2525 S.Diag(Arg->getSourceRange().getBegin(), 2526 diag::err_template_arg_reference_var) 2527 << Var->getType() << Arg->getSourceRange(); 2528 S.Diag(Param->getLocation(), diag::note_template_param_here); 2529 return true; 2530 } 2531 2532 // Okay: we've named an object with external linkage 2533 Entity = Var; 2534 2535 // If the template parameter has pointer type, we must have taken 2536 // the address of this object. 2537 if (ParamType->isReferenceType()) { 2538 if (AddressTaken) { 2539 // If we originally had an address-of operator, but the 2540 // parameter has reference type, complain and (if things look 2541 // like they will work) drop the address-of operator. 2542 if (!S.Context.hasSameUnqualifiedType(Var->getType(), 2543 ParamType.getNonReferenceType())) { 2544 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2545 << ParamType; 2546 S.Diag(Param->getLocation(), diag::note_template_param_here); 2547 return true; 2548 } 2549 2550 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2551 << ParamType 2552 << FixItHint::CreateRemoval(AddrOpLoc); 2553 S.Diag(Param->getLocation(), diag::note_template_param_here); 2554 2555 ArgType = Var->getType(); 2556 } 2557 } else if (!AddressTaken && ParamType->isPointerType()) { 2558 if (Var->getType()->isArrayType()) { 2559 // Array-to-pointer decay. 2560 ArgType = S.Context.getArrayDecayedType(Var->getType()); 2561 } else { 2562 // If the template parameter has pointer type but the address of 2563 // this object was not taken, complain and (possibly) recover by 2564 // taking the address of the entity. 2565 ArgType = S.Context.getPointerType(Var->getType()); 2566 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) { 2567 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 2568 << ParamType; 2569 S.Diag(Param->getLocation(), diag::note_template_param_here); 2570 return true; 2571 } 2572 2573 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 2574 << ParamType 2575 << FixItHint::CreateInsertion(Arg->getLocStart(), "&"); 2576 2577 S.Diag(Param->getLocation(), diag::note_template_param_here); 2578 } 2579 } 2580 } else { 2581 // We found something else, but we don't know specifically what it is. 2582 S.Diag(Arg->getSourceRange().getBegin(), 2583 diag::err_template_arg_not_object_or_func) 2584 << Arg->getSourceRange(); 2585 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); 2586 return true; 2587 } 2588 2589 if (ParamType->isPointerType() && 2590 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() && 2591 S.IsQualificationConversion(ArgType, ParamType)) { 2592 // For pointer-to-object types, qualification conversions are 2593 // permitted. 2594 } else { 2595 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) { 2596 if (!ParamRef->getPointeeType()->isFunctionType()) { 2597 // C++ [temp.arg.nontype]p5b3: 2598 // For a non-type template-parameter of type reference to 2599 // object, no conversions apply. The type referred to by the 2600 // reference may be more cv-qualified than the (otherwise 2601 // identical) type of the template- argument. The 2602 // template-parameter is bound directly to the 2603 // template-argument, which shall be an lvalue. 2604 2605 // FIXME: Other qualifiers? 2606 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers(); 2607 unsigned ArgQuals = ArgType.getCVRQualifiers(); 2608 2609 if ((ParamQuals | ArgQuals) != ParamQuals) { 2610 S.Diag(Arg->getSourceRange().getBegin(), 2611 diag::err_template_arg_ref_bind_ignores_quals) 2612 << ParamType << Arg->getType() 2613 << Arg->getSourceRange(); 2614 S.Diag(Param->getLocation(), diag::note_template_param_here); 2615 return true; 2616 } 2617 } 2618 } 2619 2620 // At this point, the template argument refers to an object or 2621 // function with external linkage. We now need to check whether the 2622 // argument and parameter types are compatible. 2623 if (!S.Context.hasSameUnqualifiedType(ArgType, 2624 ParamType.getNonReferenceType())) { 2625 // We can't perform this conversion or binding. 2626 if (ParamType->isReferenceType()) 2627 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind) 2628 << ParamType << Arg->getType() << Arg->getSourceRange(); 2629 else 2630 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) 2631 << Arg->getType() << ParamType << Arg->getSourceRange(); 2632 S.Diag(Param->getLocation(), diag::note_template_param_here); 2633 return true; 2634 } 2635 } 2636 2637 // Create the template argument. 2638 Converted = TemplateArgument(Entity->getCanonicalDecl()); 2639 S.MarkDeclarationReferenced(Arg->getLocStart(), Entity); 2640 return false; 2641} 2642 2643/// \brief Checks whether the given template argument is a pointer to 2644/// member constant according to C++ [temp.arg.nontype]p1. 2645bool Sema::CheckTemplateArgumentPointerToMember(Expr *Arg, 2646 TemplateArgument &Converted) { 2647 bool Invalid = false; 2648 2649 // See through any implicit casts we added to fix the type. 2650 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2651 Arg = Cast->getSubExpr(); 2652 2653 // C++ [temp.arg.nontype]p1: 2654 // 2655 // A template-argument for a non-type, non-template 2656 // template-parameter shall be one of: [...] 2657 // 2658 // -- a pointer to member expressed as described in 5.3.1. 2659 DeclRefExpr *DRE = 0; 2660 2661 // Ignore (and complain about) any excess parentheses. 2662 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2663 if (!Invalid) { 2664 Diag(Arg->getSourceRange().getBegin(), 2665 diag::err_template_arg_extra_parens) 2666 << Arg->getSourceRange(); 2667 Invalid = true; 2668 } 2669 2670 Arg = Parens->getSubExpr(); 2671 } 2672 2673 // A pointer-to-member constant written &Class::member. 2674 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2675 if (UnOp->getOpcode() == UO_AddrOf) { 2676 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2677 if (DRE && !DRE->getQualifier()) 2678 DRE = 0; 2679 } 2680 } 2681 // A constant of pointer-to-member type. 2682 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) { 2683 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) { 2684 if (VD->getType()->isMemberPointerType()) { 2685 if (isa<NonTypeTemplateParmDecl>(VD) || 2686 (isa<VarDecl>(VD) && 2687 Context.getCanonicalType(VD->getType()).isConstQualified())) { 2688 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2689 Converted = TemplateArgument(Arg->Retain()); 2690 else 2691 Converted = TemplateArgument(VD->getCanonicalDecl()); 2692 return Invalid; 2693 } 2694 } 2695 } 2696 2697 DRE = 0; 2698 } 2699 2700 if (!DRE) 2701 return Diag(Arg->getSourceRange().getBegin(), 2702 diag::err_template_arg_not_pointer_to_member_form) 2703 << Arg->getSourceRange(); 2704 2705 if (isa<FieldDecl>(DRE->getDecl()) || isa<CXXMethodDecl>(DRE->getDecl())) { 2706 assert((isa<FieldDecl>(DRE->getDecl()) || 2707 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && 2708 "Only non-static member pointers can make it here"); 2709 2710 // Okay: this is the address of a non-static member, and therefore 2711 // a member pointer constant. 2712 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2713 Converted = TemplateArgument(Arg->Retain()); 2714 else 2715 Converted = TemplateArgument(DRE->getDecl()->getCanonicalDecl()); 2716 return Invalid; 2717 } 2718 2719 // We found something else, but we don't know specifically what it is. 2720 Diag(Arg->getSourceRange().getBegin(), 2721 diag::err_template_arg_not_pointer_to_member_form) 2722 << Arg->getSourceRange(); 2723 Diag(DRE->getDecl()->getLocation(), 2724 diag::note_template_arg_refers_here); 2725 return true; 2726} 2727 2728/// \brief Check a template argument against its corresponding 2729/// non-type template parameter. 2730/// 2731/// This routine implements the semantics of C++ [temp.arg.nontype]. 2732/// It returns true if an error occurred, and false otherwise. \p 2733/// InstantiatedParamType is the type of the non-type template 2734/// parameter after it has been instantiated. 2735/// 2736/// If no error was detected, Converted receives the converted template argument. 2737bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, 2738 QualType InstantiatedParamType, Expr *&Arg, 2739 TemplateArgument &Converted, 2740 CheckTemplateArgumentKind CTAK) { 2741 SourceLocation StartLoc = Arg->getSourceRange().getBegin(); 2742 2743 // If either the parameter has a dependent type or the argument is 2744 // type-dependent, there's nothing we can check now. 2745 if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) { 2746 // FIXME: Produce a cloned, canonical expression? 2747 Converted = TemplateArgument(Arg); 2748 return false; 2749 } 2750 2751 // C++ [temp.arg.nontype]p5: 2752 // The following conversions are performed on each expression used 2753 // as a non-type template-argument. If a non-type 2754 // template-argument cannot be converted to the type of the 2755 // corresponding template-parameter then the program is 2756 // ill-formed. 2757 // 2758 // -- for a non-type template-parameter of integral or 2759 // enumeration type, integral promotions (4.5) and integral 2760 // conversions (4.7) are applied. 2761 QualType ParamType = InstantiatedParamType; 2762 QualType ArgType = Arg->getType(); 2763 if (ParamType->isIntegralOrEnumerationType()) { 2764 // C++ [temp.arg.nontype]p1: 2765 // A template-argument for a non-type, non-template 2766 // template-parameter shall be one of: 2767 // 2768 // -- an integral constant-expression of integral or enumeration 2769 // type; or 2770 // -- the name of a non-type template-parameter; or 2771 SourceLocation NonConstantLoc; 2772 llvm::APSInt Value; 2773 if (!ArgType->isIntegralOrEnumerationType()) { 2774 Diag(Arg->getSourceRange().getBegin(), 2775 diag::err_template_arg_not_integral_or_enumeral) 2776 << ArgType << Arg->getSourceRange(); 2777 Diag(Param->getLocation(), diag::note_template_param_here); 2778 return true; 2779 } else if (!Arg->isValueDependent() && 2780 !Arg->isIntegerConstantExpr(Value, Context, &NonConstantLoc)) { 2781 Diag(NonConstantLoc, diag::err_template_arg_not_ice) 2782 << ArgType << Arg->getSourceRange(); 2783 return true; 2784 } 2785 2786 // From here on out, all we care about are the unqualified forms 2787 // of the parameter and argument types. 2788 ParamType = ParamType.getUnqualifiedType(); 2789 ArgType = ArgType.getUnqualifiedType(); 2790 2791 // Try to convert the argument to the parameter's type. 2792 if (Context.hasSameType(ParamType, ArgType)) { 2793 // Okay: no conversion necessary 2794 } else if (CTAK == CTAK_Deduced) { 2795 // C++ [temp.deduct.type]p17: 2796 // If, in the declaration of a function template with a non-type 2797 // template-parameter, the non-type template- parameter is used 2798 // in an expression in the function parameter-list and, if the 2799 // corresponding template-argument is deduced, the 2800 // template-argument type shall match the type of the 2801 // template-parameter exactly, except that a template-argument 2802 // deduced from an array bound may be of any integral type. 2803 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch) 2804 << ArgType << ParamType; 2805 Diag(Param->getLocation(), diag::note_template_param_here); 2806 return true; 2807 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || 2808 !ParamType->isEnumeralType()) { 2809 // This is an integral promotion or conversion. 2810 ImpCastExprToType(Arg, ParamType, CK_IntegralCast); 2811 } else { 2812 // We can't perform this conversion. 2813 Diag(Arg->getSourceRange().getBegin(), 2814 diag::err_template_arg_not_convertible) 2815 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2816 Diag(Param->getLocation(), diag::note_template_param_here); 2817 return true; 2818 } 2819 2820 QualType IntegerType = Context.getCanonicalType(ParamType); 2821 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 2822 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); 2823 2824 if (!Arg->isValueDependent()) { 2825 llvm::APSInt OldValue = Value; 2826 2827 // Coerce the template argument's value to the value it will have 2828 // based on the template parameter's type. 2829 unsigned AllowedBits = Context.getTypeSize(IntegerType); 2830 if (Value.getBitWidth() != AllowedBits) 2831 Value.extOrTrunc(AllowedBits); 2832 Value.setIsSigned(IntegerType->isSignedIntegerType()); 2833 2834 // Complain if an unsigned parameter received a negative value. 2835 if (IntegerType->isUnsignedIntegerType() 2836 && (OldValue.isSigned() && OldValue.isNegative())) { 2837 Diag(Arg->getSourceRange().getBegin(), diag::warn_template_arg_negative) 2838 << OldValue.toString(10) << Value.toString(10) << Param->getType() 2839 << Arg->getSourceRange(); 2840 Diag(Param->getLocation(), diag::note_template_param_here); 2841 } 2842 2843 // Complain if we overflowed the template parameter's type. 2844 unsigned RequiredBits; 2845 if (IntegerType->isUnsignedIntegerType()) 2846 RequiredBits = OldValue.getActiveBits(); 2847 else if (OldValue.isUnsigned()) 2848 RequiredBits = OldValue.getActiveBits() + 1; 2849 else 2850 RequiredBits = OldValue.getMinSignedBits(); 2851 if (RequiredBits > AllowedBits) { 2852 Diag(Arg->getSourceRange().getBegin(), 2853 diag::warn_template_arg_too_large) 2854 << OldValue.toString(10) << Value.toString(10) << Param->getType() 2855 << Arg->getSourceRange(); 2856 Diag(Param->getLocation(), diag::note_template_param_here); 2857 } 2858 } 2859 2860 // Add the value of this argument to the list of converted 2861 // arguments. We use the bitwidth and signedness of the template 2862 // parameter. 2863 if (Arg->isValueDependent()) { 2864 // The argument is value-dependent. Create a new 2865 // TemplateArgument with the converted expression. 2866 Converted = TemplateArgument(Arg); 2867 return false; 2868 } 2869 2870 Converted = TemplateArgument(Value, 2871 ParamType->isEnumeralType() ? ParamType 2872 : IntegerType); 2873 return false; 2874 } 2875 2876 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction 2877 2878 // C++0x [temp.arg.nontype]p5 bullets 2, 4 and 6 permit conversion 2879 // from a template argument of type std::nullptr_t to a non-type 2880 // template parameter of type pointer to object, pointer to 2881 // function, or pointer-to-member, respectively. 2882 if (ArgType->isNullPtrType() && 2883 (ParamType->isPointerType() || ParamType->isMemberPointerType())) { 2884 Converted = TemplateArgument((NamedDecl *)0); 2885 return false; 2886 } 2887 2888 // Handle pointer-to-function, reference-to-function, and 2889 // pointer-to-member-function all in (roughly) the same way. 2890 if (// -- For a non-type template-parameter of type pointer to 2891 // function, only the function-to-pointer conversion (4.3) is 2892 // applied. If the template-argument represents a set of 2893 // overloaded functions (or a pointer to such), the matching 2894 // function is selected from the set (13.4). 2895 (ParamType->isPointerType() && 2896 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) || 2897 // -- For a non-type template-parameter of type reference to 2898 // function, no conversions apply. If the template-argument 2899 // represents a set of overloaded functions, the matching 2900 // function is selected from the set (13.4). 2901 (ParamType->isReferenceType() && 2902 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) || 2903 // -- For a non-type template-parameter of type pointer to 2904 // member function, no conversions apply. If the 2905 // template-argument represents a set of overloaded member 2906 // functions, the matching member function is selected from 2907 // the set (13.4). 2908 (ParamType->isMemberPointerType() && 2909 ParamType->getAs<MemberPointerType>()->getPointeeType() 2910 ->isFunctionType())) { 2911 2912 if (Arg->getType() == Context.OverloadTy) { 2913 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 2914 true, 2915 FoundResult)) { 2916 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 2917 return true; 2918 2919 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 2920 ArgType = Arg->getType(); 2921 } else 2922 return true; 2923 } 2924 2925 if (!ParamType->isMemberPointerType()) 2926 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2927 ParamType, 2928 Arg, Converted); 2929 2930 if (IsQualificationConversion(ArgType, ParamType.getNonReferenceType())) { 2931 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 2932 } else if (!Context.hasSameUnqualifiedType(ArgType, 2933 ParamType.getNonReferenceType())) { 2934 // We can't perform this conversion. 2935 Diag(Arg->getSourceRange().getBegin(), 2936 diag::err_template_arg_not_convertible) 2937 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2938 Diag(Param->getLocation(), diag::note_template_param_here); 2939 return true; 2940 } 2941 2942 return CheckTemplateArgumentPointerToMember(Arg, Converted); 2943 } 2944 2945 if (ParamType->isPointerType()) { 2946 // -- for a non-type template-parameter of type pointer to 2947 // object, qualification conversions (4.4) and the 2948 // array-to-pointer conversion (4.2) are applied. 2949 // C++0x also allows a value of std::nullptr_t. 2950 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() && 2951 "Only object pointers allowed here"); 2952 2953 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2954 ParamType, 2955 Arg, Converted); 2956 } 2957 2958 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { 2959 // -- For a non-type template-parameter of type reference to 2960 // object, no conversions apply. The type referred to by the 2961 // reference may be more cv-qualified than the (otherwise 2962 // identical) type of the template-argument. The 2963 // template-parameter is bound directly to the 2964 // template-argument, which must be an lvalue. 2965 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() && 2966 "Only object references allowed here"); 2967 2968 if (Arg->getType() == Context.OverloadTy) { 2969 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 2970 ParamRefType->getPointeeType(), 2971 true, 2972 FoundResult)) { 2973 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 2974 return true; 2975 2976 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 2977 ArgType = Arg->getType(); 2978 } else 2979 return true; 2980 } 2981 2982 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2983 ParamType, 2984 Arg, Converted); 2985 } 2986 2987 // -- For a non-type template-parameter of type pointer to data 2988 // member, qualification conversions (4.4) are applied. 2989 assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); 2990 2991 if (Context.hasSameUnqualifiedType(ParamType, ArgType)) { 2992 // Types match exactly: nothing more to do here. 2993 } else if (IsQualificationConversion(ArgType, ParamType)) { 2994 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 2995 } else { 2996 // We can't perform this conversion. 2997 Diag(Arg->getSourceRange().getBegin(), 2998 diag::err_template_arg_not_convertible) 2999 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 3000 Diag(Param->getLocation(), diag::note_template_param_here); 3001 return true; 3002 } 3003 3004 return CheckTemplateArgumentPointerToMember(Arg, Converted); 3005} 3006 3007/// \brief Check a template argument against its corresponding 3008/// template template parameter. 3009/// 3010/// This routine implements the semantics of C++ [temp.arg.template]. 3011/// It returns true if an error occurred, and false otherwise. 3012bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, 3013 const TemplateArgumentLoc &Arg) { 3014 TemplateName Name = Arg.getArgument().getAsTemplate(); 3015 TemplateDecl *Template = Name.getAsTemplateDecl(); 3016 if (!Template) { 3017 // Any dependent template name is fine. 3018 assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); 3019 return false; 3020 } 3021 3022 // C++ [temp.arg.template]p1: 3023 // A template-argument for a template template-parameter shall be 3024 // the name of a class template, expressed as id-expression. Only 3025 // primary class templates are considered when matching the 3026 // template template argument with the corresponding parameter; 3027 // partial specializations are not considered even if their 3028 // parameter lists match that of the template template parameter. 3029 // 3030 // Note that we also allow template template parameters here, which 3031 // will happen when we are dealing with, e.g., class template 3032 // partial specializations. 3033 if (!isa<ClassTemplateDecl>(Template) && 3034 !isa<TemplateTemplateParmDecl>(Template)) { 3035 assert(isa<FunctionTemplateDecl>(Template) && 3036 "Only function templates are possible here"); 3037 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); 3038 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) 3039 << Template; 3040 } 3041 3042 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), 3043 Param->getTemplateParameters(), 3044 true, 3045 TPL_TemplateTemplateArgumentMatch, 3046 Arg.getLocation()); 3047} 3048 3049/// \brief Given a non-type template argument that refers to a 3050/// declaration and the type of its corresponding non-type template 3051/// parameter, produce an expression that properly refers to that 3052/// declaration. 3053ExprResult 3054Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg, 3055 QualType ParamType, 3056 SourceLocation Loc) { 3057 assert(Arg.getKind() == TemplateArgument::Declaration && 3058 "Only declaration template arguments permitted here"); 3059 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl()); 3060 3061 if (VD->getDeclContext()->isRecord() && 3062 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD))) { 3063 // If the value is a class member, we might have a pointer-to-member. 3064 // Determine whether the non-type template template parameter is of 3065 // pointer-to-member type. If so, we need to build an appropriate 3066 // expression for a pointer-to-member, since a "normal" DeclRefExpr 3067 // would refer to the member itself. 3068 if (ParamType->isMemberPointerType()) { 3069 QualType ClassType 3070 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext())); 3071 NestedNameSpecifier *Qualifier 3072 = NestedNameSpecifier::Create(Context, 0, false, 3073 ClassType.getTypePtr()); 3074 CXXScopeSpec SS; 3075 SS.setScopeRep(Qualifier); 3076 ExprResult RefExpr = BuildDeclRefExpr(VD, 3077 VD->getType().getNonReferenceType(), 3078 Loc, 3079 &SS); 3080 if (RefExpr.isInvalid()) 3081 return ExprError(); 3082 3083 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3084 3085 // We might need to perform a trailing qualification conversion, since 3086 // the element type on the parameter could be more qualified than the 3087 // element type in the expression we constructed. 3088 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(), 3089 ParamType.getUnqualifiedType())) { 3090 Expr *RefE = RefExpr.takeAs<Expr>(); 3091 ImpCastExprToType(RefE, ParamType.getUnqualifiedType(), CK_NoOp); 3092 RefExpr = Owned(RefE); 3093 } 3094 3095 assert(!RefExpr.isInvalid() && 3096 Context.hasSameType(((Expr*) RefExpr.get())->getType(), 3097 ParamType.getUnqualifiedType())); 3098 return move(RefExpr); 3099 } 3100 } 3101 3102 QualType T = VD->getType().getNonReferenceType(); 3103 if (ParamType->isPointerType()) { 3104 // When the non-type template parameter is a pointer, take the 3105 // address of the declaration. 3106 ExprResult RefExpr = BuildDeclRefExpr(VD, T, Loc); 3107 if (RefExpr.isInvalid()) 3108 return ExprError(); 3109 3110 if (T->isFunctionType() || T->isArrayType()) { 3111 // Decay functions and arrays. 3112 Expr *RefE = (Expr *)RefExpr.get(); 3113 DefaultFunctionArrayConversion(RefE); 3114 if (RefE != RefExpr.get()) { 3115 RefExpr.release(); 3116 RefExpr = Owned(RefE); 3117 } 3118 3119 return move(RefExpr); 3120 } 3121 3122 // Take the address of everything else 3123 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3124 } 3125 3126 // If the non-type template parameter has reference type, qualify the 3127 // resulting declaration reference with the extra qualifiers on the 3128 // type that the reference refers to. 3129 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) 3130 T = Context.getQualifiedType(T, TargetRef->getPointeeType().getQualifiers()); 3131 3132 return BuildDeclRefExpr(VD, T, Loc); 3133} 3134 3135/// \brief Construct a new expression that refers to the given 3136/// integral template argument with the given source-location 3137/// information. 3138/// 3139/// This routine takes care of the mapping from an integral template 3140/// argument (which may have any integral type) to the appropriate 3141/// literal value. 3142ExprResult 3143Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg, 3144 SourceLocation Loc) { 3145 assert(Arg.getKind() == TemplateArgument::Integral && 3146 "Operation is only value for integral template arguments"); 3147 QualType T = Arg.getIntegralType(); 3148 if (T->isCharType() || T->isWideCharType()) 3149 return Owned(new (Context) CharacterLiteral( 3150 Arg.getAsIntegral()->getZExtValue(), 3151 T->isWideCharType(), 3152 T, 3153 Loc)); 3154 if (T->isBooleanType()) 3155 return Owned(new (Context) CXXBoolLiteralExpr( 3156 Arg.getAsIntegral()->getBoolValue(), 3157 T, 3158 Loc)); 3159 3160 return Owned(IntegerLiteral::Create(Context, *Arg.getAsIntegral(), T, Loc)); 3161} 3162 3163 3164/// \brief Determine whether the given template parameter lists are 3165/// equivalent. 3166/// 3167/// \param New The new template parameter list, typically written in the 3168/// source code as part of a new template declaration. 3169/// 3170/// \param Old The old template parameter list, typically found via 3171/// name lookup of the template declared with this template parameter 3172/// list. 3173/// 3174/// \param Complain If true, this routine will produce a diagnostic if 3175/// the template parameter lists are not equivalent. 3176/// 3177/// \param Kind describes how we are to match the template parameter lists. 3178/// 3179/// \param TemplateArgLoc If this source location is valid, then we 3180/// are actually checking the template parameter list of a template 3181/// argument (New) against the template parameter list of its 3182/// corresponding template template parameter (Old). We produce 3183/// slightly different diagnostics in this scenario. 3184/// 3185/// \returns True if the template parameter lists are equal, false 3186/// otherwise. 3187bool 3188Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, 3189 TemplateParameterList *Old, 3190 bool Complain, 3191 TemplateParameterListEqualKind Kind, 3192 SourceLocation TemplateArgLoc) { 3193 if (Old->size() != New->size()) { 3194 if (Complain) { 3195 unsigned NextDiag = diag::err_template_param_list_different_arity; 3196 if (TemplateArgLoc.isValid()) { 3197 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3198 NextDiag = diag::note_template_param_list_different_arity; 3199 } 3200 Diag(New->getTemplateLoc(), NextDiag) 3201 << (New->size() > Old->size()) 3202 << (Kind != TPL_TemplateMatch) 3203 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); 3204 Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) 3205 << (Kind != TPL_TemplateMatch) 3206 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); 3207 } 3208 3209 return false; 3210 } 3211 3212 for (TemplateParameterList::iterator OldParm = Old->begin(), 3213 OldParmEnd = Old->end(), NewParm = New->begin(); 3214 OldParm != OldParmEnd; ++OldParm, ++NewParm) { 3215 if ((*OldParm)->getKind() != (*NewParm)->getKind()) { 3216 if (Complain) { 3217 unsigned NextDiag = diag::err_template_param_different_kind; 3218 if (TemplateArgLoc.isValid()) { 3219 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3220 NextDiag = diag::note_template_param_different_kind; 3221 } 3222 Diag((*NewParm)->getLocation(), NextDiag) 3223 << (Kind != TPL_TemplateMatch); 3224 Diag((*OldParm)->getLocation(), diag::note_template_prev_declaration) 3225 << (Kind != TPL_TemplateMatch); 3226 } 3227 return false; 3228 } 3229 3230 if (TemplateTypeParmDecl *OldTTP 3231 = dyn_cast<TemplateTypeParmDecl>(*OldParm)) { 3232 // Template type parameters are equivalent if either both are template 3233 // type parameter packs or neither are (since we know we're at the same 3234 // index). 3235 TemplateTypeParmDecl *NewTTP = cast<TemplateTypeParmDecl>(*NewParm); 3236 if (OldTTP->isParameterPack() != NewTTP->isParameterPack()) { 3237 // FIXME: Implement the rules in C++0x [temp.arg.template]p5 that 3238 // allow one to match a template parameter pack in the template 3239 // parameter list of a template template parameter to one or more 3240 // template parameters in the template parameter list of the 3241 // corresponding template template argument. 3242 if (Complain) { 3243 unsigned NextDiag = diag::err_template_parameter_pack_non_pack; 3244 if (TemplateArgLoc.isValid()) { 3245 Diag(TemplateArgLoc, 3246 diag::err_template_arg_template_params_mismatch); 3247 NextDiag = diag::note_template_parameter_pack_non_pack; 3248 } 3249 Diag(NewTTP->getLocation(), NextDiag) 3250 << 0 << NewTTP->isParameterPack(); 3251 Diag(OldTTP->getLocation(), diag::note_template_parameter_pack_here) 3252 << 0 << OldTTP->isParameterPack(); 3253 } 3254 return false; 3255 } 3256 } else if (NonTypeTemplateParmDecl *OldNTTP 3257 = dyn_cast<NonTypeTemplateParmDecl>(*OldParm)) { 3258 // The types of non-type template parameters must agree. 3259 NonTypeTemplateParmDecl *NewNTTP 3260 = cast<NonTypeTemplateParmDecl>(*NewParm); 3261 3262 // If we are matching a template template argument to a template 3263 // template parameter and one of the non-type template parameter types 3264 // is dependent, then we must wait until template instantiation time 3265 // to actually compare the arguments. 3266 if (Kind == TPL_TemplateTemplateArgumentMatch && 3267 (OldNTTP->getType()->isDependentType() || 3268 NewNTTP->getType()->isDependentType())) 3269 continue; 3270 3271 if (Context.getCanonicalType(OldNTTP->getType()) != 3272 Context.getCanonicalType(NewNTTP->getType())) { 3273 if (Complain) { 3274 unsigned NextDiag = diag::err_template_nontype_parm_different_type; 3275 if (TemplateArgLoc.isValid()) { 3276 Diag(TemplateArgLoc, 3277 diag::err_template_arg_template_params_mismatch); 3278 NextDiag = diag::note_template_nontype_parm_different_type; 3279 } 3280 Diag(NewNTTP->getLocation(), NextDiag) 3281 << NewNTTP->getType() 3282 << (Kind != TPL_TemplateMatch); 3283 Diag(OldNTTP->getLocation(), 3284 diag::note_template_nontype_parm_prev_declaration) 3285 << OldNTTP->getType(); 3286 } 3287 return false; 3288 } 3289 } else { 3290 // The template parameter lists of template template 3291 // parameters must agree. 3292 assert(isa<TemplateTemplateParmDecl>(*OldParm) && 3293 "Only template template parameters handled here"); 3294 TemplateTemplateParmDecl *OldTTP 3295 = cast<TemplateTemplateParmDecl>(*OldParm); 3296 TemplateTemplateParmDecl *NewTTP 3297 = cast<TemplateTemplateParmDecl>(*NewParm); 3298 if (!TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), 3299 OldTTP->getTemplateParameters(), 3300 Complain, 3301 (Kind == TPL_TemplateMatch? TPL_TemplateTemplateParmMatch : Kind), 3302 TemplateArgLoc)) 3303 return false; 3304 } 3305 } 3306 3307 return true; 3308} 3309 3310/// \brief Check whether a template can be declared within this scope. 3311/// 3312/// If the template declaration is valid in this scope, returns 3313/// false. Otherwise, issues a diagnostic and returns true. 3314bool 3315Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { 3316 // Find the nearest enclosing declaration scope. 3317 while ((S->getFlags() & Scope::DeclScope) == 0 || 3318 (S->getFlags() & Scope::TemplateParamScope) != 0) 3319 S = S->getParent(); 3320 3321 // C++ [temp]p2: 3322 // A template-declaration can appear only as a namespace scope or 3323 // class scope declaration. 3324 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 3325 if (Ctx && isa<LinkageSpecDecl>(Ctx) && 3326 cast<LinkageSpecDecl>(Ctx)->getLanguage() != LinkageSpecDecl::lang_cxx) 3327 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) 3328 << TemplateParams->getSourceRange(); 3329 3330 while (Ctx && isa<LinkageSpecDecl>(Ctx)) 3331 Ctx = Ctx->getParent(); 3332 3333 if (Ctx && (Ctx->isFileContext() || Ctx->isRecord())) 3334 return false; 3335 3336 return Diag(TemplateParams->getTemplateLoc(), 3337 diag::err_template_outside_namespace_or_class_scope) 3338 << TemplateParams->getSourceRange(); 3339} 3340 3341/// \brief Determine what kind of template specialization the given declaration 3342/// is. 3343static TemplateSpecializationKind getTemplateSpecializationKind(NamedDecl *D) { 3344 if (!D) 3345 return TSK_Undeclared; 3346 3347 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) 3348 return Record->getTemplateSpecializationKind(); 3349 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) 3350 return Function->getTemplateSpecializationKind(); 3351 if (VarDecl *Var = dyn_cast<VarDecl>(D)) 3352 return Var->getTemplateSpecializationKind(); 3353 3354 return TSK_Undeclared; 3355} 3356 3357/// \brief Check whether a specialization is well-formed in the current 3358/// context. 3359/// 3360/// This routine determines whether a template specialization can be declared 3361/// in the current context (C++ [temp.expl.spec]p2). 3362/// 3363/// \param S the semantic analysis object for which this check is being 3364/// performed. 3365/// 3366/// \param Specialized the entity being specialized or instantiated, which 3367/// may be a kind of template (class template, function template, etc.) or 3368/// a member of a class template (member function, static data member, 3369/// member class). 3370/// 3371/// \param PrevDecl the previous declaration of this entity, if any. 3372/// 3373/// \param Loc the location of the explicit specialization or instantiation of 3374/// this entity. 3375/// 3376/// \param IsPartialSpecialization whether this is a partial specialization of 3377/// a class template. 3378/// 3379/// \returns true if there was an error that we cannot recover from, false 3380/// otherwise. 3381static bool CheckTemplateSpecializationScope(Sema &S, 3382 NamedDecl *Specialized, 3383 NamedDecl *PrevDecl, 3384 SourceLocation Loc, 3385 bool IsPartialSpecialization) { 3386 // Keep these "kind" numbers in sync with the %select statements in the 3387 // various diagnostics emitted by this routine. 3388 int EntityKind = 0; 3389 bool isTemplateSpecialization = false; 3390 if (isa<ClassTemplateDecl>(Specialized)) { 3391 EntityKind = IsPartialSpecialization? 1 : 0; 3392 isTemplateSpecialization = true; 3393 } else if (isa<FunctionTemplateDecl>(Specialized)) { 3394 EntityKind = 2; 3395 isTemplateSpecialization = true; 3396 } else if (isa<CXXMethodDecl>(Specialized)) 3397 EntityKind = 3; 3398 else if (isa<VarDecl>(Specialized)) 3399 EntityKind = 4; 3400 else if (isa<RecordDecl>(Specialized)) 3401 EntityKind = 5; 3402 else { 3403 S.Diag(Loc, diag::err_template_spec_unknown_kind); 3404 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3405 return true; 3406 } 3407 3408 // C++ [temp.expl.spec]p2: 3409 // An explicit specialization shall be declared in the namespace 3410 // of which the template is a member, or, for member templates, in 3411 // the namespace of which the enclosing class or enclosing class 3412 // template is a member. An explicit specialization of a member 3413 // function, member class or static data member of a class 3414 // template shall be declared in the namespace of which the class 3415 // template is a member. Such a declaration may also be a 3416 // definition. If the declaration is not a definition, the 3417 // specialization may be defined later in the name- space in which 3418 // the explicit specialization was declared, or in a namespace 3419 // that encloses the one in which the explicit specialization was 3420 // declared. 3421 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) { 3422 S.Diag(Loc, diag::err_template_spec_decl_function_scope) 3423 << Specialized; 3424 return true; 3425 } 3426 3427 if (S.CurContext->isRecord() && !IsPartialSpecialization) { 3428 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 3429 << Specialized; 3430 return true; 3431 } 3432 3433 // C++ [temp.class.spec]p6: 3434 // A class template partial specialization may be declared or redeclared 3435 // in any namespace scope in which its definition may be defined (14.5.1 3436 // and 14.5.2). 3437 bool ComplainedAboutScope = false; 3438 DeclContext *SpecializedContext 3439 = Specialized->getDeclContext()->getEnclosingNamespaceContext(); 3440 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); 3441 if ((!PrevDecl || 3442 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || 3443 getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)){ 3444 // C++ [temp.exp.spec]p2: 3445 // An explicit specialization shall be declared in the namespace of which 3446 // the template is a member, or, for member templates, in the namespace 3447 // of which the enclosing class or enclosing class template is a member. 3448 // An explicit specialization of a member function, member class or 3449 // static data member of a class template shall be declared in the 3450 // namespace of which the class template is a member. 3451 // 3452 // C++0x [temp.expl.spec]p2: 3453 // An explicit specialization shall be declared in a namespace enclosing 3454 // the specialized template. 3455 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext) && 3456 !(S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext))) { 3457 bool IsCPlusPlus0xExtension 3458 = !S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext); 3459 if (isa<TranslationUnitDecl>(SpecializedContext)) 3460 S.Diag(Loc, IsCPlusPlus0xExtension 3461 ? diag::ext_template_spec_decl_out_of_scope_global 3462 : diag::err_template_spec_decl_out_of_scope_global) 3463 << EntityKind << Specialized; 3464 else if (isa<NamespaceDecl>(SpecializedContext)) 3465 S.Diag(Loc, IsCPlusPlus0xExtension 3466 ? diag::ext_template_spec_decl_out_of_scope 3467 : diag::err_template_spec_decl_out_of_scope) 3468 << EntityKind << Specialized 3469 << cast<NamedDecl>(SpecializedContext); 3470 3471 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3472 ComplainedAboutScope = true; 3473 } 3474 } 3475 3476 // Make sure that this redeclaration (or definition) occurs in an enclosing 3477 // namespace. 3478 // Note that HandleDeclarator() performs this check for explicit 3479 // specializations of function templates, static data members, and member 3480 // functions, so we skip the check here for those kinds of entities. 3481 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. 3482 // Should we refactor that check, so that it occurs later? 3483 if (!ComplainedAboutScope && !DC->Encloses(SpecializedContext) && 3484 !(isa<FunctionTemplateDecl>(Specialized) || isa<VarDecl>(Specialized) || 3485 isa<FunctionDecl>(Specialized))) { 3486 if (isa<TranslationUnitDecl>(SpecializedContext)) 3487 S.Diag(Loc, diag::err_template_spec_redecl_global_scope) 3488 << EntityKind << Specialized; 3489 else if (isa<NamespaceDecl>(SpecializedContext)) 3490 S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope) 3491 << EntityKind << Specialized 3492 << cast<NamedDecl>(SpecializedContext); 3493 3494 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3495 } 3496 3497 // FIXME: check for specialization-after-instantiation errors and such. 3498 3499 return false; 3500} 3501 3502/// \brief Check the non-type template arguments of a class template 3503/// partial specialization according to C++ [temp.class.spec]p9. 3504/// 3505/// \param TemplateParams the template parameters of the primary class 3506/// template. 3507/// 3508/// \param TemplateArg the template arguments of the class template 3509/// partial specialization. 3510/// 3511/// \param MirrorsPrimaryTemplate will be set true if the class 3512/// template partial specialization arguments are identical to the 3513/// implicit template arguments of the primary template. This is not 3514/// necessarily an error (C++0x), and it is left to the caller to diagnose 3515/// this condition when it is an error. 3516/// 3517/// \returns true if there was an error, false otherwise. 3518bool Sema::CheckClassTemplatePartialSpecializationArgs( 3519 TemplateParameterList *TemplateParams, 3520 const TemplateArgumentListBuilder &TemplateArgs, 3521 bool &MirrorsPrimaryTemplate) { 3522 // FIXME: the interface to this function will have to change to 3523 // accommodate variadic templates. 3524 MirrorsPrimaryTemplate = true; 3525 3526 const TemplateArgument *ArgList = TemplateArgs.getFlatArguments(); 3527 3528 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 3529 // Determine whether the template argument list of the partial 3530 // specialization is identical to the implicit argument list of 3531 // the primary template. The caller may need to diagnostic this as 3532 // an error per C++ [temp.class.spec]p9b3. 3533 if (MirrorsPrimaryTemplate) { 3534 if (TemplateTypeParmDecl *TTP 3535 = dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(I))) { 3536 if (Context.getCanonicalType(Context.getTypeDeclType(TTP)) != 3537 Context.getCanonicalType(ArgList[I].getAsType())) 3538 MirrorsPrimaryTemplate = false; 3539 } else if (TemplateTemplateParmDecl *TTP 3540 = dyn_cast<TemplateTemplateParmDecl>( 3541 TemplateParams->getParam(I))) { 3542 TemplateName Name = ArgList[I].getAsTemplate(); 3543 TemplateTemplateParmDecl *ArgDecl 3544 = dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()); 3545 if (!ArgDecl || 3546 ArgDecl->getIndex() != TTP->getIndex() || 3547 ArgDecl->getDepth() != TTP->getDepth()) 3548 MirrorsPrimaryTemplate = false; 3549 } 3550 } 3551 3552 NonTypeTemplateParmDecl *Param 3553 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I)); 3554 if (!Param) { 3555 continue; 3556 } 3557 3558 Expr *ArgExpr = ArgList[I].getAsExpr(); 3559 if (!ArgExpr) { 3560 MirrorsPrimaryTemplate = false; 3561 continue; 3562 } 3563 3564 // C++ [temp.class.spec]p8: 3565 // A non-type argument is non-specialized if it is the name of a 3566 // non-type parameter. All other non-type arguments are 3567 // specialized. 3568 // 3569 // Below, we check the two conditions that only apply to 3570 // specialized non-type arguments, so skip any non-specialized 3571 // arguments. 3572 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr)) 3573 if (NonTypeTemplateParmDecl *NTTP 3574 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl())) { 3575 if (MirrorsPrimaryTemplate && 3576 (Param->getIndex() != NTTP->getIndex() || 3577 Param->getDepth() != NTTP->getDepth())) 3578 MirrorsPrimaryTemplate = false; 3579 3580 continue; 3581 } 3582 3583 // C++ [temp.class.spec]p9: 3584 // Within the argument list of a class template partial 3585 // specialization, the following restrictions apply: 3586 // -- A partially specialized non-type argument expression 3587 // shall not involve a template parameter of the partial 3588 // specialization except when the argument expression is a 3589 // simple identifier. 3590 if (ArgExpr->isTypeDependent() || ArgExpr->isValueDependent()) { 3591 Diag(ArgExpr->getLocStart(), 3592 diag::err_dependent_non_type_arg_in_partial_spec) 3593 << ArgExpr->getSourceRange(); 3594 return true; 3595 } 3596 3597 // -- The type of a template parameter corresponding to a 3598 // specialized non-type argument shall not be dependent on a 3599 // parameter of the specialization. 3600 if (Param->getType()->isDependentType()) { 3601 Diag(ArgExpr->getLocStart(), 3602 diag::err_dependent_typed_non_type_arg_in_partial_spec) 3603 << Param->getType() 3604 << ArgExpr->getSourceRange(); 3605 Diag(Param->getLocation(), diag::note_template_param_here); 3606 return true; 3607 } 3608 3609 MirrorsPrimaryTemplate = false; 3610 } 3611 3612 return false; 3613} 3614 3615/// \brief Retrieve the previous declaration of the given declaration. 3616static NamedDecl *getPreviousDecl(NamedDecl *ND) { 3617 if (VarDecl *VD = dyn_cast<VarDecl>(ND)) 3618 return VD->getPreviousDeclaration(); 3619 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 3620 return FD->getPreviousDeclaration(); 3621 if (TagDecl *TD = dyn_cast<TagDecl>(ND)) 3622 return TD->getPreviousDeclaration(); 3623 if (TypedefDecl *TD = dyn_cast<TypedefDecl>(ND)) 3624 return TD->getPreviousDeclaration(); 3625 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 3626 return FTD->getPreviousDeclaration(); 3627 if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND)) 3628 return CTD->getPreviousDeclaration(); 3629 return 0; 3630} 3631 3632DeclResult 3633Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, 3634 TagUseKind TUK, 3635 SourceLocation KWLoc, 3636 CXXScopeSpec &SS, 3637 TemplateTy TemplateD, 3638 SourceLocation TemplateNameLoc, 3639 SourceLocation LAngleLoc, 3640 ASTTemplateArgsPtr TemplateArgsIn, 3641 SourceLocation RAngleLoc, 3642 AttributeList *Attr, 3643 MultiTemplateParamsArg TemplateParameterLists) { 3644 assert(TUK != TUK_Reference && "References are not specializations"); 3645 3646 // Find the class template we're specializing 3647 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 3648 ClassTemplateDecl *ClassTemplate 3649 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl()); 3650 3651 if (!ClassTemplate) { 3652 Diag(TemplateNameLoc, diag::err_not_class_template_specialization) 3653 << (Name.getAsTemplateDecl() && 3654 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())); 3655 return true; 3656 } 3657 3658 bool isExplicitSpecialization = false; 3659 bool isPartialSpecialization = false; 3660 3661 // Check the validity of the template headers that introduce this 3662 // template. 3663 // FIXME: We probably shouldn't complain about these headers for 3664 // friend declarations. 3665 bool Invalid = false; 3666 TemplateParameterList *TemplateParams 3667 = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, SS, 3668 (TemplateParameterList**)TemplateParameterLists.get(), 3669 TemplateParameterLists.size(), 3670 TUK == TUK_Friend, 3671 isExplicitSpecialization, 3672 Invalid); 3673 if (Invalid) 3674 return true; 3675 3676 unsigned NumMatchedTemplateParamLists = TemplateParameterLists.size(); 3677 if (TemplateParams) 3678 --NumMatchedTemplateParamLists; 3679 3680 if (TemplateParams && TemplateParams->size() > 0) { 3681 isPartialSpecialization = true; 3682 3683 // C++ [temp.class.spec]p10: 3684 // The template parameter list of a specialization shall not 3685 // contain default template argument values. 3686 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 3687 Decl *Param = TemplateParams->getParam(I); 3688 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) { 3689 if (TTP->hasDefaultArgument()) { 3690 Diag(TTP->getDefaultArgumentLoc(), 3691 diag::err_default_arg_in_partial_spec); 3692 TTP->removeDefaultArgument(); 3693 } 3694 } else if (NonTypeTemplateParmDecl *NTTP 3695 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 3696 if (Expr *DefArg = NTTP->getDefaultArgument()) { 3697 Diag(NTTP->getDefaultArgumentLoc(), 3698 diag::err_default_arg_in_partial_spec) 3699 << DefArg->getSourceRange(); 3700 NTTP->removeDefaultArgument(); 3701 } 3702 } else { 3703 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param); 3704 if (TTP->hasDefaultArgument()) { 3705 Diag(TTP->getDefaultArgument().getLocation(), 3706 diag::err_default_arg_in_partial_spec) 3707 << TTP->getDefaultArgument().getSourceRange(); 3708 TTP->removeDefaultArgument(); 3709 } 3710 } 3711 } 3712 } else if (TemplateParams) { 3713 if (TUK == TUK_Friend) 3714 Diag(KWLoc, diag::err_template_spec_friend) 3715 << FixItHint::CreateRemoval( 3716 SourceRange(TemplateParams->getTemplateLoc(), 3717 TemplateParams->getRAngleLoc())) 3718 << SourceRange(LAngleLoc, RAngleLoc); 3719 else 3720 isExplicitSpecialization = true; 3721 } else if (TUK != TUK_Friend) { 3722 Diag(KWLoc, diag::err_template_spec_needs_header) 3723 << FixItHint::CreateInsertion(KWLoc, "template<> "); 3724 isExplicitSpecialization = true; 3725 } 3726 3727 // Check that the specialization uses the same tag kind as the 3728 // original template. 3729 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 3730 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!"); 3731 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 3732 Kind, KWLoc, 3733 *ClassTemplate->getIdentifier())) { 3734 Diag(KWLoc, diag::err_use_with_wrong_tag) 3735 << ClassTemplate 3736 << FixItHint::CreateReplacement(KWLoc, 3737 ClassTemplate->getTemplatedDecl()->getKindName()); 3738 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 3739 diag::note_previous_use); 3740 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 3741 } 3742 3743 // Translate the parser's template argument list in our AST format. 3744 TemplateArgumentListInfo TemplateArgs; 3745 TemplateArgs.setLAngleLoc(LAngleLoc); 3746 TemplateArgs.setRAngleLoc(RAngleLoc); 3747 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 3748 3749 // Check that the template argument list is well-formed for this 3750 // template. 3751 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 3752 TemplateArgs.size()); 3753 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 3754 TemplateArgs, false, Converted)) 3755 return true; 3756 3757 assert((Converted.structuredSize() == 3758 ClassTemplate->getTemplateParameters()->size()) && 3759 "Converted template argument list is too short!"); 3760 3761 // Find the class template (partial) specialization declaration that 3762 // corresponds to these arguments. 3763 if (isPartialSpecialization) { 3764 bool MirrorsPrimaryTemplate; 3765 if (CheckClassTemplatePartialSpecializationArgs( 3766 ClassTemplate->getTemplateParameters(), 3767 Converted, MirrorsPrimaryTemplate)) 3768 return true; 3769 3770 if (MirrorsPrimaryTemplate) { 3771 // C++ [temp.class.spec]p9b3: 3772 // 3773 // -- The argument list of the specialization shall not be identical 3774 // to the implicit argument list of the primary template. 3775 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 3776 << (TUK == TUK_Definition) 3777 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); 3778 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS, 3779 ClassTemplate->getIdentifier(), 3780 TemplateNameLoc, 3781 Attr, 3782 TemplateParams, 3783 AS_none); 3784 } 3785 3786 // FIXME: Diagnose friend partial specializations 3787 3788 if (!Name.isDependent() && 3789 !TemplateSpecializationType::anyDependentTemplateArguments( 3790 TemplateArgs.getArgumentArray(), 3791 TemplateArgs.size())) { 3792 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) 3793 << ClassTemplate->getDeclName(); 3794 isPartialSpecialization = false; 3795 } 3796 } 3797 3798 void *InsertPos = 0; 3799 ClassTemplateSpecializationDecl *PrevDecl = 0; 3800 3801 if (isPartialSpecialization) 3802 // FIXME: Template parameter list matters, too 3803 PrevDecl 3804 = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(), 3805 Converted.flatSize(), 3806 InsertPos); 3807 else 3808 PrevDecl 3809 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 3810 Converted.flatSize(), InsertPos); 3811 3812 ClassTemplateSpecializationDecl *Specialization = 0; 3813 3814 // Check whether we can declare a class template specialization in 3815 // the current scope. 3816 if (TUK != TUK_Friend && 3817 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl, 3818 TemplateNameLoc, 3819 isPartialSpecialization)) 3820 return true; 3821 3822 // The canonical type 3823 QualType CanonType; 3824 if (PrevDecl && 3825 (PrevDecl->getSpecializationKind() == TSK_Undeclared || 3826 TUK == TUK_Friend)) { 3827 // Since the only prior class template specialization with these 3828 // arguments was referenced but not declared, or we're only 3829 // referencing this specialization as a friend, reuse that 3830 // declaration node as our own, updating its source location to 3831 // reflect our new declaration. 3832 Specialization = PrevDecl; 3833 Specialization->setLocation(TemplateNameLoc); 3834 PrevDecl = 0; 3835 CanonType = Context.getTypeDeclType(Specialization); 3836 } else if (isPartialSpecialization) { 3837 // Build the canonical type that describes the converted template 3838 // arguments of the class template partial specialization. 3839 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 3840 CanonType = Context.getTemplateSpecializationType(CanonTemplate, 3841 Converted.getFlatArguments(), 3842 Converted.flatSize()); 3843 3844 // Create a new class template partial specialization declaration node. 3845 ClassTemplatePartialSpecializationDecl *PrevPartial 3846 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl); 3847 unsigned SequenceNumber = PrevPartial? PrevPartial->getSequenceNumber() 3848 : ClassTemplate->getNextPartialSpecSequenceNumber(); 3849 ClassTemplatePartialSpecializationDecl *Partial 3850 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind, 3851 ClassTemplate->getDeclContext(), 3852 TemplateNameLoc, 3853 TemplateParams, 3854 ClassTemplate, 3855 Converted, 3856 TemplateArgs, 3857 CanonType, 3858 PrevPartial, 3859 SequenceNumber); 3860 SetNestedNameSpecifier(Partial, SS); 3861 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 3862 Partial->setTemplateParameterListsInfo(Context, 3863 NumMatchedTemplateParamLists, 3864 (TemplateParameterList**) TemplateParameterLists.release()); 3865 } 3866 3867 if (!PrevPartial) 3868 ClassTemplate->AddPartialSpecialization(Partial, InsertPos); 3869 Specialization = Partial; 3870 3871 // If we are providing an explicit specialization of a member class 3872 // template specialization, make a note of that. 3873 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 3874 PrevPartial->setMemberSpecialization(); 3875 3876 // Check that all of the template parameters of the class template 3877 // partial specialization are deducible from the template 3878 // arguments. If not, this class template partial specialization 3879 // will never be used. 3880 llvm::SmallVector<bool, 8> DeducibleParams; 3881 DeducibleParams.resize(TemplateParams->size()); 3882 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 3883 TemplateParams->getDepth(), 3884 DeducibleParams); 3885 unsigned NumNonDeducible = 0; 3886 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) 3887 if (!DeducibleParams[I]) 3888 ++NumNonDeducible; 3889 3890 if (NumNonDeducible) { 3891 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 3892 << (NumNonDeducible > 1) 3893 << SourceRange(TemplateNameLoc, RAngleLoc); 3894 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 3895 if (!DeducibleParams[I]) { 3896 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 3897 if (Param->getDeclName()) 3898 Diag(Param->getLocation(), 3899 diag::note_partial_spec_unused_parameter) 3900 << Param->getDeclName(); 3901 else 3902 Diag(Param->getLocation(), 3903 diag::note_partial_spec_unused_parameter) 3904 << "<anonymous>"; 3905 } 3906 } 3907 } 3908 } else { 3909 // Create a new class template specialization declaration node for 3910 // this explicit specialization or friend declaration. 3911 Specialization 3912 = ClassTemplateSpecializationDecl::Create(Context, Kind, 3913 ClassTemplate->getDeclContext(), 3914 TemplateNameLoc, 3915 ClassTemplate, 3916 Converted, 3917 PrevDecl); 3918 SetNestedNameSpecifier(Specialization, SS); 3919 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 3920 Specialization->setTemplateParameterListsInfo(Context, 3921 NumMatchedTemplateParamLists, 3922 (TemplateParameterList**) TemplateParameterLists.release()); 3923 } 3924 3925 if (!PrevDecl) 3926 ClassTemplate->AddSpecialization(Specialization, InsertPos); 3927 3928 CanonType = Context.getTypeDeclType(Specialization); 3929 } 3930 3931 // C++ [temp.expl.spec]p6: 3932 // If a template, a member template or the member of a class template is 3933 // explicitly specialized then that specialization shall be declared 3934 // before the first use of that specialization that would cause an implicit 3935 // instantiation to take place, in every translation unit in which such a 3936 // use occurs; no diagnostic is required. 3937 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 3938 bool Okay = false; 3939 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 3940 // Is there any previous explicit specialization declaration? 3941 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 3942 Okay = true; 3943 break; 3944 } 3945 } 3946 3947 if (!Okay) { 3948 SourceRange Range(TemplateNameLoc, RAngleLoc); 3949 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 3950 << Context.getTypeDeclType(Specialization) << Range; 3951 3952 Diag(PrevDecl->getPointOfInstantiation(), 3953 diag::note_instantiation_required_here) 3954 << (PrevDecl->getTemplateSpecializationKind() 3955 != TSK_ImplicitInstantiation); 3956 return true; 3957 } 3958 } 3959 3960 // If this is not a friend, note that this is an explicit specialization. 3961 if (TUK != TUK_Friend) 3962 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 3963 3964 // Check that this isn't a redefinition of this specialization. 3965 if (TUK == TUK_Definition) { 3966 if (RecordDecl *Def = Specialization->getDefinition()) { 3967 SourceRange Range(TemplateNameLoc, RAngleLoc); 3968 Diag(TemplateNameLoc, diag::err_redefinition) 3969 << Context.getTypeDeclType(Specialization) << Range; 3970 Diag(Def->getLocation(), diag::note_previous_definition); 3971 Specialization->setInvalidDecl(); 3972 return true; 3973 } 3974 } 3975 3976 // Build the fully-sugared type for this class template 3977 // specialization as the user wrote in the specialization 3978 // itself. This means that we'll pretty-print the type retrieved 3979 // from the specialization's declaration the way that the user 3980 // actually wrote the specialization, rather than formatting the 3981 // name based on the "canonical" representation used to store the 3982 // template arguments in the specialization. 3983 TypeSourceInfo *WrittenTy 3984 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 3985 TemplateArgs, CanonType); 3986 if (TUK != TUK_Friend) { 3987 Specialization->setTypeAsWritten(WrittenTy); 3988 if (TemplateParams) 3989 Specialization->setTemplateKeywordLoc(TemplateParams->getTemplateLoc()); 3990 } 3991 TemplateArgsIn.release(); 3992 3993 // C++ [temp.expl.spec]p9: 3994 // A template explicit specialization is in the scope of the 3995 // namespace in which the template was defined. 3996 // 3997 // We actually implement this paragraph where we set the semantic 3998 // context (in the creation of the ClassTemplateSpecializationDecl), 3999 // but we also maintain the lexical context where the actual 4000 // definition occurs. 4001 Specialization->setLexicalDeclContext(CurContext); 4002 4003 // We may be starting the definition of this specialization. 4004 if (TUK == TUK_Definition) 4005 Specialization->startDefinition(); 4006 4007 if (TUK == TUK_Friend) { 4008 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 4009 TemplateNameLoc, 4010 WrittenTy, 4011 /*FIXME:*/KWLoc); 4012 Friend->setAccess(AS_public); 4013 CurContext->addDecl(Friend); 4014 } else { 4015 // Add the specialization into its lexical context, so that it can 4016 // be seen when iterating through the list of declarations in that 4017 // context. However, specializations are not found by name lookup. 4018 CurContext->addDecl(Specialization); 4019 } 4020 return Specialization; 4021} 4022 4023Decl *Sema::ActOnTemplateDeclarator(Scope *S, 4024 MultiTemplateParamsArg TemplateParameterLists, 4025 Declarator &D) { 4026 return HandleDeclarator(S, D, move(TemplateParameterLists), false); 4027} 4028 4029Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope, 4030 MultiTemplateParamsArg TemplateParameterLists, 4031 Declarator &D) { 4032 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 4033 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4034 "Not a function declarator!"); 4035 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4036 4037 if (FTI.hasPrototype) { 4038 // FIXME: Diagnose arguments without names in C. 4039 } 4040 4041 Scope *ParentScope = FnBodyScope->getParent(); 4042 4043 Decl *DP = HandleDeclarator(ParentScope, D, 4044 move(TemplateParameterLists), 4045 /*IsFunctionDefinition=*/true); 4046 if (FunctionTemplateDecl *FunctionTemplate 4047 = dyn_cast_or_null<FunctionTemplateDecl>(DP)) 4048 return ActOnStartOfFunctionDef(FnBodyScope, 4049 FunctionTemplate->getTemplatedDecl()); 4050 if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(DP)) 4051 return ActOnStartOfFunctionDef(FnBodyScope, Function); 4052 return 0; 4053} 4054 4055/// \brief Strips various properties off an implicit instantiation 4056/// that has just been explicitly specialized. 4057static void StripImplicitInstantiation(NamedDecl *D) { 4058 D->dropAttrs(); 4059 4060 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4061 FD->setInlineSpecified(false); 4062 } 4063} 4064 4065/// \brief Diagnose cases where we have an explicit template specialization 4066/// before/after an explicit template instantiation, producing diagnostics 4067/// for those cases where they are required and determining whether the 4068/// new specialization/instantiation will have any effect. 4069/// 4070/// \param NewLoc the location of the new explicit specialization or 4071/// instantiation. 4072/// 4073/// \param NewTSK the kind of the new explicit specialization or instantiation. 4074/// 4075/// \param PrevDecl the previous declaration of the entity. 4076/// 4077/// \param PrevTSK the kind of the old explicit specialization or instantiatin. 4078/// 4079/// \param PrevPointOfInstantiation if valid, indicates where the previus 4080/// declaration was instantiated (either implicitly or explicitly). 4081/// 4082/// \param HasNoEffect will be set to true to indicate that the new 4083/// specialization or instantiation has no effect and should be ignored. 4084/// 4085/// \returns true if there was an error that should prevent the introduction of 4086/// the new declaration into the AST, false otherwise. 4087bool 4088Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc, 4089 TemplateSpecializationKind NewTSK, 4090 NamedDecl *PrevDecl, 4091 TemplateSpecializationKind PrevTSK, 4092 SourceLocation PrevPointOfInstantiation, 4093 bool &HasNoEffect) { 4094 HasNoEffect = false; 4095 4096 switch (NewTSK) { 4097 case TSK_Undeclared: 4098 case TSK_ImplicitInstantiation: 4099 assert(false && "Don't check implicit instantiations here"); 4100 return false; 4101 4102 case TSK_ExplicitSpecialization: 4103 switch (PrevTSK) { 4104 case TSK_Undeclared: 4105 case TSK_ExplicitSpecialization: 4106 // Okay, we're just specializing something that is either already 4107 // explicitly specialized or has merely been mentioned without any 4108 // instantiation. 4109 return false; 4110 4111 case TSK_ImplicitInstantiation: 4112 if (PrevPointOfInstantiation.isInvalid()) { 4113 // The declaration itself has not actually been instantiated, so it is 4114 // still okay to specialize it. 4115 StripImplicitInstantiation(PrevDecl); 4116 return false; 4117 } 4118 // Fall through 4119 4120 case TSK_ExplicitInstantiationDeclaration: 4121 case TSK_ExplicitInstantiationDefinition: 4122 assert((PrevTSK == TSK_ImplicitInstantiation || 4123 PrevPointOfInstantiation.isValid()) && 4124 "Explicit instantiation without point of instantiation?"); 4125 4126 // C++ [temp.expl.spec]p6: 4127 // If a template, a member template or the member of a class template 4128 // is explicitly specialized then that specialization shall be declared 4129 // before the first use of that specialization that would cause an 4130 // implicit instantiation to take place, in every translation unit in 4131 // which such a use occurs; no diagnostic is required. 4132 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 4133 // Is there any previous explicit specialization declaration? 4134 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) 4135 return false; 4136 } 4137 4138 Diag(NewLoc, diag::err_specialization_after_instantiation) 4139 << PrevDecl; 4140 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here) 4141 << (PrevTSK != TSK_ImplicitInstantiation); 4142 4143 return true; 4144 } 4145 break; 4146 4147 case TSK_ExplicitInstantiationDeclaration: 4148 switch (PrevTSK) { 4149 case TSK_ExplicitInstantiationDeclaration: 4150 // This explicit instantiation declaration is redundant (that's okay). 4151 HasNoEffect = true; 4152 return false; 4153 4154 case TSK_Undeclared: 4155 case TSK_ImplicitInstantiation: 4156 // We're explicitly instantiating something that may have already been 4157 // implicitly instantiated; that's fine. 4158 return false; 4159 4160 case TSK_ExplicitSpecialization: 4161 // C++0x [temp.explicit]p4: 4162 // For a given set of template parameters, if an explicit instantiation 4163 // of a template appears after a declaration of an explicit 4164 // specialization for that template, the explicit instantiation has no 4165 // effect. 4166 HasNoEffect = true; 4167 return false; 4168 4169 case TSK_ExplicitInstantiationDefinition: 4170 // C++0x [temp.explicit]p10: 4171 // If an entity is the subject of both an explicit instantiation 4172 // declaration and an explicit instantiation definition in the same 4173 // translation unit, the definition shall follow the declaration. 4174 Diag(NewLoc, 4175 diag::err_explicit_instantiation_declaration_after_definition); 4176 Diag(PrevPointOfInstantiation, 4177 diag::note_explicit_instantiation_definition_here); 4178 assert(PrevPointOfInstantiation.isValid() && 4179 "Explicit instantiation without point of instantiation?"); 4180 HasNoEffect = true; 4181 return false; 4182 } 4183 break; 4184 4185 case TSK_ExplicitInstantiationDefinition: 4186 switch (PrevTSK) { 4187 case TSK_Undeclared: 4188 case TSK_ImplicitInstantiation: 4189 // We're explicitly instantiating something that may have already been 4190 // implicitly instantiated; that's fine. 4191 return false; 4192 4193 case TSK_ExplicitSpecialization: 4194 // C++ DR 259, C++0x [temp.explicit]p4: 4195 // For a given set of template parameters, if an explicit 4196 // instantiation of a template appears after a declaration of 4197 // an explicit specialization for that template, the explicit 4198 // instantiation has no effect. 4199 // 4200 // In C++98/03 mode, we only give an extension warning here, because it 4201 // is not harmful to try to explicitly instantiate something that 4202 // has been explicitly specialized. 4203 if (!getLangOptions().CPlusPlus0x) { 4204 Diag(NewLoc, diag::ext_explicit_instantiation_after_specialization) 4205 << PrevDecl; 4206 Diag(PrevDecl->getLocation(), 4207 diag::note_previous_template_specialization); 4208 } 4209 HasNoEffect = true; 4210 return false; 4211 4212 case TSK_ExplicitInstantiationDeclaration: 4213 // We're explicity instantiating a definition for something for which we 4214 // were previously asked to suppress instantiations. That's fine. 4215 return false; 4216 4217 case TSK_ExplicitInstantiationDefinition: 4218 // C++0x [temp.spec]p5: 4219 // For a given template and a given set of template-arguments, 4220 // - an explicit instantiation definition shall appear at most once 4221 // in a program, 4222 Diag(NewLoc, diag::err_explicit_instantiation_duplicate) 4223 << PrevDecl; 4224 Diag(PrevPointOfInstantiation, 4225 diag::note_previous_explicit_instantiation); 4226 HasNoEffect = true; 4227 return false; 4228 } 4229 break; 4230 } 4231 4232 assert(false && "Missing specialization/instantiation case?"); 4233 4234 return false; 4235} 4236 4237/// \brief Perform semantic analysis for the given dependent function 4238/// template specialization. The only possible way to get a dependent 4239/// function template specialization is with a friend declaration, 4240/// like so: 4241/// 4242/// template <class T> void foo(T); 4243/// template <class T> class A { 4244/// friend void foo<>(T); 4245/// }; 4246/// 4247/// There really isn't any useful analysis we can do here, so we 4248/// just store the information. 4249bool 4250Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD, 4251 const TemplateArgumentListInfo &ExplicitTemplateArgs, 4252 LookupResult &Previous) { 4253 // Remove anything from Previous that isn't a function template in 4254 // the correct context. 4255 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4256 LookupResult::Filter F = Previous.makeFilter(); 4257 while (F.hasNext()) { 4258 NamedDecl *D = F.next()->getUnderlyingDecl(); 4259 if (!isa<FunctionTemplateDecl>(D) || 4260 !FDLookupContext->InEnclosingNamespaceSetOf( 4261 D->getDeclContext()->getRedeclContext())) 4262 F.erase(); 4263 } 4264 F.done(); 4265 4266 // Should this be diagnosed here? 4267 if (Previous.empty()) return true; 4268 4269 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(), 4270 ExplicitTemplateArgs); 4271 return false; 4272} 4273 4274/// \brief Perform semantic analysis for the given function template 4275/// specialization. 4276/// 4277/// This routine performs all of the semantic analysis required for an 4278/// explicit function template specialization. On successful completion, 4279/// the function declaration \p FD will become a function template 4280/// specialization. 4281/// 4282/// \param FD the function declaration, which will be updated to become a 4283/// function template specialization. 4284/// 4285/// \param ExplicitTemplateArgs the explicitly-provided template arguments, 4286/// if any. Note that this may be valid info even when 0 arguments are 4287/// explicitly provided as in, e.g., \c void sort<>(char*, char*); 4288/// as it anyway contains info on the angle brackets locations. 4289/// 4290/// \param PrevDecl the set of declarations that may be specialized by 4291/// this function specialization. 4292bool 4293Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD, 4294 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4295 LookupResult &Previous) { 4296 // The set of function template specializations that could match this 4297 // explicit function template specialization. 4298 UnresolvedSet<8> Candidates; 4299 4300 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4301 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 4302 I != E; ++I) { 4303 NamedDecl *Ovl = (*I)->getUnderlyingDecl(); 4304 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) { 4305 // Only consider templates found within the same semantic lookup scope as 4306 // FD. 4307 if (!FDLookupContext->InEnclosingNamespaceSetOf( 4308 Ovl->getDeclContext()->getRedeclContext())) 4309 continue; 4310 4311 // C++ [temp.expl.spec]p11: 4312 // A trailing template-argument can be left unspecified in the 4313 // template-id naming an explicit function template specialization 4314 // provided it can be deduced from the function argument type. 4315 // Perform template argument deduction to determine whether we may be 4316 // specializing this template. 4317 // FIXME: It is somewhat wasteful to build 4318 TemplateDeductionInfo Info(Context, FD->getLocation()); 4319 FunctionDecl *Specialization = 0; 4320 if (TemplateDeductionResult TDK 4321 = DeduceTemplateArguments(FunTmpl, ExplicitTemplateArgs, 4322 FD->getType(), 4323 Specialization, 4324 Info)) { 4325 // FIXME: Template argument deduction failed; record why it failed, so 4326 // that we can provide nifty diagnostics. 4327 (void)TDK; 4328 continue; 4329 } 4330 4331 // Record this candidate. 4332 Candidates.addDecl(Specialization, I.getAccess()); 4333 } 4334 } 4335 4336 // Find the most specialized function template. 4337 UnresolvedSetIterator Result 4338 = getMostSpecialized(Candidates.begin(), Candidates.end(), 4339 TPOC_Other, FD->getLocation(), 4340 PDiag(diag::err_function_template_spec_no_match) 4341 << FD->getDeclName(), 4342 PDiag(diag::err_function_template_spec_ambiguous) 4343 << FD->getDeclName() << (ExplicitTemplateArgs != 0), 4344 PDiag(diag::note_function_template_spec_matched)); 4345 if (Result == Candidates.end()) 4346 return true; 4347 4348 // Ignore access information; it doesn't figure into redeclaration checking. 4349 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 4350 Specialization->setLocation(FD->getLocation()); 4351 4352 // FIXME: Check if the prior specialization has a point of instantiation. 4353 // If so, we have run afoul of . 4354 4355 // If this is a friend declaration, then we're not really declaring 4356 // an explicit specialization. 4357 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None); 4358 4359 // Check the scope of this explicit specialization. 4360 if (!isFriend && 4361 CheckTemplateSpecializationScope(*this, 4362 Specialization->getPrimaryTemplate(), 4363 Specialization, FD->getLocation(), 4364 false)) 4365 return true; 4366 4367 // C++ [temp.expl.spec]p6: 4368 // If a template, a member template or the member of a class template is 4369 // explicitly specialized then that specialization shall be declared 4370 // before the first use of that specialization that would cause an implicit 4371 // instantiation to take place, in every translation unit in which such a 4372 // use occurs; no diagnostic is required. 4373 FunctionTemplateSpecializationInfo *SpecInfo 4374 = Specialization->getTemplateSpecializationInfo(); 4375 assert(SpecInfo && "Function template specialization info missing?"); 4376 4377 bool HasNoEffect = false; 4378 if (!isFriend && 4379 CheckSpecializationInstantiationRedecl(FD->getLocation(), 4380 TSK_ExplicitSpecialization, 4381 Specialization, 4382 SpecInfo->getTemplateSpecializationKind(), 4383 SpecInfo->getPointOfInstantiation(), 4384 HasNoEffect)) 4385 return true; 4386 4387 // Mark the prior declaration as an explicit specialization, so that later 4388 // clients know that this is an explicit specialization. 4389 if (!isFriend) { 4390 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization); 4391 MarkUnusedFileScopedDecl(Specialization); 4392 } 4393 4394 // Turn the given function declaration into a function template 4395 // specialization, with the template arguments from the previous 4396 // specialization. 4397 // Take copies of (semantic and syntactic) template argument lists. 4398 const TemplateArgumentList* TemplArgs = new (Context) 4399 TemplateArgumentList(Specialization->getTemplateSpecializationArgs()); 4400 const TemplateArgumentListInfo* TemplArgsAsWritten = ExplicitTemplateArgs 4401 ? new (Context) TemplateArgumentListInfo(*ExplicitTemplateArgs) : 0; 4402 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(), 4403 TemplArgs, /*InsertPos=*/0, 4404 SpecInfo->getTemplateSpecializationKind(), 4405 TemplArgsAsWritten); 4406 4407 // The "previous declaration" for this function template specialization is 4408 // the prior function template specialization. 4409 Previous.clear(); 4410 Previous.addDecl(Specialization); 4411 return false; 4412} 4413 4414/// \brief Perform semantic analysis for the given non-template member 4415/// specialization. 4416/// 4417/// This routine performs all of the semantic analysis required for an 4418/// explicit member function specialization. On successful completion, 4419/// the function declaration \p FD will become a member function 4420/// specialization. 4421/// 4422/// \param Member the member declaration, which will be updated to become a 4423/// specialization. 4424/// 4425/// \param Previous the set of declarations, one of which may be specialized 4426/// by this function specialization; the set will be modified to contain the 4427/// redeclared member. 4428bool 4429Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) { 4430 assert(!isa<TemplateDecl>(Member) && "Only for non-template members"); 4431 4432 // Try to find the member we are instantiating. 4433 NamedDecl *Instantiation = 0; 4434 NamedDecl *InstantiatedFrom = 0; 4435 MemberSpecializationInfo *MSInfo = 0; 4436 4437 if (Previous.empty()) { 4438 // Nowhere to look anyway. 4439 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) { 4440 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 4441 I != E; ++I) { 4442 NamedDecl *D = (*I)->getUnderlyingDecl(); 4443 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 4444 if (Context.hasSameType(Function->getType(), Method->getType())) { 4445 Instantiation = Method; 4446 InstantiatedFrom = Method->getInstantiatedFromMemberFunction(); 4447 MSInfo = Method->getMemberSpecializationInfo(); 4448 break; 4449 } 4450 } 4451 } 4452 } else if (isa<VarDecl>(Member)) { 4453 VarDecl *PrevVar; 4454 if (Previous.isSingleResult() && 4455 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl()))) 4456 if (PrevVar->isStaticDataMember()) { 4457 Instantiation = PrevVar; 4458 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember(); 4459 MSInfo = PrevVar->getMemberSpecializationInfo(); 4460 } 4461 } else if (isa<RecordDecl>(Member)) { 4462 CXXRecordDecl *PrevRecord; 4463 if (Previous.isSingleResult() && 4464 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) { 4465 Instantiation = PrevRecord; 4466 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass(); 4467 MSInfo = PrevRecord->getMemberSpecializationInfo(); 4468 } 4469 } 4470 4471 if (!Instantiation) { 4472 // There is no previous declaration that matches. Since member 4473 // specializations are always out-of-line, the caller will complain about 4474 // this mismatch later. 4475 return false; 4476 } 4477 4478 // If this is a friend, just bail out here before we start turning 4479 // things into explicit specializations. 4480 if (Member->getFriendObjectKind() != Decl::FOK_None) { 4481 // Preserve instantiation information. 4482 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) { 4483 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction( 4484 cast<CXXMethodDecl>(InstantiatedFrom), 4485 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind()); 4486 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) { 4487 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 4488 cast<CXXRecordDecl>(InstantiatedFrom), 4489 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind()); 4490 } 4491 4492 Previous.clear(); 4493 Previous.addDecl(Instantiation); 4494 return false; 4495 } 4496 4497 // Make sure that this is a specialization of a member. 4498 if (!InstantiatedFrom) { 4499 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated) 4500 << Member; 4501 Diag(Instantiation->getLocation(), diag::note_specialized_decl); 4502 return true; 4503 } 4504 4505 // C++ [temp.expl.spec]p6: 4506 // If a template, a member template or the member of a class template is 4507 // explicitly specialized then that spe- cialization shall be declared 4508 // before the first use of that specialization that would cause an implicit 4509 // instantiation to take place, in every translation unit in which such a 4510 // use occurs; no diagnostic is required. 4511 assert(MSInfo && "Member specialization info missing?"); 4512 4513 bool HasNoEffect = false; 4514 if (CheckSpecializationInstantiationRedecl(Member->getLocation(), 4515 TSK_ExplicitSpecialization, 4516 Instantiation, 4517 MSInfo->getTemplateSpecializationKind(), 4518 MSInfo->getPointOfInstantiation(), 4519 HasNoEffect)) 4520 return true; 4521 4522 // Check the scope of this explicit specialization. 4523 if (CheckTemplateSpecializationScope(*this, 4524 InstantiatedFrom, 4525 Instantiation, Member->getLocation(), 4526 false)) 4527 return true; 4528 4529 // Note that this is an explicit instantiation of a member. 4530 // the original declaration to note that it is an explicit specialization 4531 // (if it was previously an implicit instantiation). This latter step 4532 // makes bookkeeping easier. 4533 if (isa<FunctionDecl>(Member)) { 4534 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation); 4535 if (InstantiationFunction->getTemplateSpecializationKind() == 4536 TSK_ImplicitInstantiation) { 4537 InstantiationFunction->setTemplateSpecializationKind( 4538 TSK_ExplicitSpecialization); 4539 InstantiationFunction->setLocation(Member->getLocation()); 4540 } 4541 4542 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction( 4543 cast<CXXMethodDecl>(InstantiatedFrom), 4544 TSK_ExplicitSpecialization); 4545 MarkUnusedFileScopedDecl(InstantiationFunction); 4546 } else if (isa<VarDecl>(Member)) { 4547 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation); 4548 if (InstantiationVar->getTemplateSpecializationKind() == 4549 TSK_ImplicitInstantiation) { 4550 InstantiationVar->setTemplateSpecializationKind( 4551 TSK_ExplicitSpecialization); 4552 InstantiationVar->setLocation(Member->getLocation()); 4553 } 4554 4555 Context.setInstantiatedFromStaticDataMember(cast<VarDecl>(Member), 4556 cast<VarDecl>(InstantiatedFrom), 4557 TSK_ExplicitSpecialization); 4558 MarkUnusedFileScopedDecl(InstantiationVar); 4559 } else { 4560 assert(isa<CXXRecordDecl>(Member) && "Only member classes remain"); 4561 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation); 4562 if (InstantiationClass->getTemplateSpecializationKind() == 4563 TSK_ImplicitInstantiation) { 4564 InstantiationClass->setTemplateSpecializationKind( 4565 TSK_ExplicitSpecialization); 4566 InstantiationClass->setLocation(Member->getLocation()); 4567 } 4568 4569 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 4570 cast<CXXRecordDecl>(InstantiatedFrom), 4571 TSK_ExplicitSpecialization); 4572 } 4573 4574 // Save the caller the trouble of having to figure out which declaration 4575 // this specialization matches. 4576 Previous.clear(); 4577 Previous.addDecl(Instantiation); 4578 return false; 4579} 4580 4581/// \brief Check the scope of an explicit instantiation. 4582/// 4583/// \returns true if a serious error occurs, false otherwise. 4584static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D, 4585 SourceLocation InstLoc, 4586 bool WasQualifiedName) { 4587 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext(); 4588 DeclContext *CurContext = S.CurContext->getRedeclContext(); 4589 4590 if (CurContext->isRecord()) { 4591 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class) 4592 << D; 4593 return true; 4594 } 4595 4596 // C++0x [temp.explicit]p2: 4597 // An explicit instantiation shall appear in an enclosing namespace of its 4598 // template. 4599 // 4600 // This is DR275, which we do not retroactively apply to C++98/03. 4601 if (S.getLangOptions().CPlusPlus0x && 4602 !CurContext->Encloses(OrigContext)) { 4603 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) 4604 S.Diag(InstLoc, 4605 S.getLangOptions().CPlusPlus0x? 4606 diag::err_explicit_instantiation_out_of_scope 4607 : diag::warn_explicit_instantiation_out_of_scope_0x) 4608 << D << NS; 4609 else 4610 S.Diag(InstLoc, 4611 S.getLangOptions().CPlusPlus0x? 4612 diag::err_explicit_instantiation_must_be_global 4613 : diag::warn_explicit_instantiation_out_of_scope_0x) 4614 << D; 4615 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 4616 return false; 4617 } 4618 4619 // C++0x [temp.explicit]p2: 4620 // If the name declared in the explicit instantiation is an unqualified 4621 // name, the explicit instantiation shall appear in the namespace where 4622 // its template is declared or, if that namespace is inline (7.3.1), any 4623 // namespace from its enclosing namespace set. 4624 if (WasQualifiedName) 4625 return false; 4626 4627 if (CurContext->InEnclosingNamespaceSetOf(OrigContext)) 4628 return false; 4629 4630 S.Diag(InstLoc, 4631 S.getLangOptions().CPlusPlus0x? 4632 diag::err_explicit_instantiation_unqualified_wrong_namespace 4633 : diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x) 4634 << D << OrigContext; 4635 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 4636 return false; 4637} 4638 4639/// \brief Determine whether the given scope specifier has a template-id in it. 4640static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) { 4641 if (!SS.isSet()) 4642 return false; 4643 4644 // C++0x [temp.explicit]p2: 4645 // If the explicit instantiation is for a member function, a member class 4646 // or a static data member of a class template specialization, the name of 4647 // the class template specialization in the qualified-id for the member 4648 // name shall be a simple-template-id. 4649 // 4650 // C++98 has the same restriction, just worded differently. 4651 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 4652 NNS; NNS = NNS->getPrefix()) 4653 if (Type *T = NNS->getAsType()) 4654 if (isa<TemplateSpecializationType>(T)) 4655 return true; 4656 4657 return false; 4658} 4659 4660// Explicit instantiation of a class template specialization 4661DeclResult 4662Sema::ActOnExplicitInstantiation(Scope *S, 4663 SourceLocation ExternLoc, 4664 SourceLocation TemplateLoc, 4665 unsigned TagSpec, 4666 SourceLocation KWLoc, 4667 const CXXScopeSpec &SS, 4668 TemplateTy TemplateD, 4669 SourceLocation TemplateNameLoc, 4670 SourceLocation LAngleLoc, 4671 ASTTemplateArgsPtr TemplateArgsIn, 4672 SourceLocation RAngleLoc, 4673 AttributeList *Attr) { 4674 // Find the class template we're specializing 4675 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 4676 ClassTemplateDecl *ClassTemplate 4677 = cast<ClassTemplateDecl>(Name.getAsTemplateDecl()); 4678 4679 // Check that the specialization uses the same tag kind as the 4680 // original template. 4681 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 4682 assert(Kind != TTK_Enum && 4683 "Invalid enum tag in class template explicit instantiation!"); 4684 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 4685 Kind, KWLoc, 4686 *ClassTemplate->getIdentifier())) { 4687 Diag(KWLoc, diag::err_use_with_wrong_tag) 4688 << ClassTemplate 4689 << FixItHint::CreateReplacement(KWLoc, 4690 ClassTemplate->getTemplatedDecl()->getKindName()); 4691 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 4692 diag::note_previous_use); 4693 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 4694 } 4695 4696 // C++0x [temp.explicit]p2: 4697 // There are two forms of explicit instantiation: an explicit instantiation 4698 // definition and an explicit instantiation declaration. An explicit 4699 // instantiation declaration begins with the extern keyword. [...] 4700 TemplateSpecializationKind TSK 4701 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4702 : TSK_ExplicitInstantiationDeclaration; 4703 4704 // Translate the parser's template argument list in our AST format. 4705 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 4706 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 4707 4708 // Check that the template argument list is well-formed for this 4709 // template. 4710 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 4711 TemplateArgs.size()); 4712 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 4713 TemplateArgs, false, Converted)) 4714 return true; 4715 4716 assert((Converted.structuredSize() == 4717 ClassTemplate->getTemplateParameters()->size()) && 4718 "Converted template argument list is too short!"); 4719 4720 // Find the class template specialization declaration that 4721 // corresponds to these arguments. 4722 void *InsertPos = 0; 4723 ClassTemplateSpecializationDecl *PrevDecl 4724 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 4725 Converted.flatSize(), InsertPos); 4726 4727 TemplateSpecializationKind PrevDecl_TSK 4728 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared; 4729 4730 // C++0x [temp.explicit]p2: 4731 // [...] An explicit instantiation shall appear in an enclosing 4732 // namespace of its template. [...] 4733 // 4734 // This is C++ DR 275. 4735 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc, 4736 SS.isSet())) 4737 return true; 4738 4739 ClassTemplateSpecializationDecl *Specialization = 0; 4740 4741 bool ReusedDecl = false; 4742 bool HasNoEffect = false; 4743 if (PrevDecl) { 4744 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK, 4745 PrevDecl, PrevDecl_TSK, 4746 PrevDecl->getPointOfInstantiation(), 4747 HasNoEffect)) 4748 return PrevDecl; 4749 4750 // Even though HasNoEffect == true means that this explicit instantiation 4751 // has no effect on semantics, we go on to put its syntax in the AST. 4752 4753 if (PrevDecl_TSK == TSK_ImplicitInstantiation || 4754 PrevDecl_TSK == TSK_Undeclared) { 4755 // Since the only prior class template specialization with these 4756 // arguments was referenced but not declared, reuse that 4757 // declaration node as our own, updating the source location 4758 // for the template name to reflect our new declaration. 4759 // (Other source locations will be updated later.) 4760 Specialization = PrevDecl; 4761 Specialization->setLocation(TemplateNameLoc); 4762 PrevDecl = 0; 4763 ReusedDecl = true; 4764 } 4765 } 4766 4767 if (!Specialization) { 4768 // Create a new class template specialization declaration node for 4769 // this explicit specialization. 4770 Specialization 4771 = ClassTemplateSpecializationDecl::Create(Context, Kind, 4772 ClassTemplate->getDeclContext(), 4773 TemplateNameLoc, 4774 ClassTemplate, 4775 Converted, PrevDecl); 4776 SetNestedNameSpecifier(Specialization, SS); 4777 4778 if (!HasNoEffect && !PrevDecl) { 4779 // Insert the new specialization. 4780 ClassTemplate->AddSpecialization(Specialization, InsertPos); 4781 } 4782 } 4783 4784 // Build the fully-sugared type for this explicit instantiation as 4785 // the user wrote in the explicit instantiation itself. This means 4786 // that we'll pretty-print the type retrieved from the 4787 // specialization's declaration the way that the user actually wrote 4788 // the explicit instantiation, rather than formatting the name based 4789 // on the "canonical" representation used to store the template 4790 // arguments in the specialization. 4791 TypeSourceInfo *WrittenTy 4792 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 4793 TemplateArgs, 4794 Context.getTypeDeclType(Specialization)); 4795 Specialization->setTypeAsWritten(WrittenTy); 4796 TemplateArgsIn.release(); 4797 4798 // Set source locations for keywords. 4799 Specialization->setExternLoc(ExternLoc); 4800 Specialization->setTemplateKeywordLoc(TemplateLoc); 4801 4802 // Add the explicit instantiation into its lexical context. However, 4803 // since explicit instantiations are never found by name lookup, we 4804 // just put it into the declaration context directly. 4805 Specialization->setLexicalDeclContext(CurContext); 4806 CurContext->addDecl(Specialization); 4807 4808 // Syntax is now OK, so return if it has no other effect on semantics. 4809 if (HasNoEffect) { 4810 // Set the template specialization kind. 4811 Specialization->setTemplateSpecializationKind(TSK); 4812 return Specialization; 4813 } 4814 4815 // C++ [temp.explicit]p3: 4816 // A definition of a class template or class member template 4817 // shall be in scope at the point of the explicit instantiation of 4818 // the class template or class member template. 4819 // 4820 // This check comes when we actually try to perform the 4821 // instantiation. 4822 ClassTemplateSpecializationDecl *Def 4823 = cast_or_null<ClassTemplateSpecializationDecl>( 4824 Specialization->getDefinition()); 4825 if (!Def) 4826 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK); 4827 else if (TSK == TSK_ExplicitInstantiationDefinition) { 4828 MarkVTableUsed(TemplateNameLoc, Specialization, true); 4829 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation()); 4830 } 4831 4832 // Instantiate the members of this class template specialization. 4833 Def = cast_or_null<ClassTemplateSpecializationDecl>( 4834 Specialization->getDefinition()); 4835 if (Def) { 4836 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind(); 4837 4838 // Fix a TSK_ExplicitInstantiationDeclaration followed by a 4839 // TSK_ExplicitInstantiationDefinition 4840 if (Old_TSK == TSK_ExplicitInstantiationDeclaration && 4841 TSK == TSK_ExplicitInstantiationDefinition) 4842 Def->setTemplateSpecializationKind(TSK); 4843 4844 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK); 4845 } 4846 4847 // Set the template specialization kind. 4848 Specialization->setTemplateSpecializationKind(TSK); 4849 return Specialization; 4850} 4851 4852// Explicit instantiation of a member class of a class template. 4853DeclResult 4854Sema::ActOnExplicitInstantiation(Scope *S, 4855 SourceLocation ExternLoc, 4856 SourceLocation TemplateLoc, 4857 unsigned TagSpec, 4858 SourceLocation KWLoc, 4859 CXXScopeSpec &SS, 4860 IdentifierInfo *Name, 4861 SourceLocation NameLoc, 4862 AttributeList *Attr) { 4863 4864 bool Owned = false; 4865 bool IsDependent = false; 4866 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference, 4867 KWLoc, SS, Name, NameLoc, Attr, AS_none, 4868 MultiTemplateParamsArg(*this, 0, 0), 4869 Owned, IsDependent); 4870 assert(!IsDependent && "explicit instantiation of dependent name not yet handled"); 4871 4872 if (!TagD) 4873 return true; 4874 4875 TagDecl *Tag = cast<TagDecl>(TagD); 4876 if (Tag->isEnum()) { 4877 Diag(TemplateLoc, diag::err_explicit_instantiation_enum) 4878 << Context.getTypeDeclType(Tag); 4879 return true; 4880 } 4881 4882 if (Tag->isInvalidDecl()) 4883 return true; 4884 4885 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag); 4886 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass(); 4887 if (!Pattern) { 4888 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type) 4889 << Context.getTypeDeclType(Record); 4890 Diag(Record->getLocation(), diag::note_nontemplate_decl_here); 4891 return true; 4892 } 4893 4894 // C++0x [temp.explicit]p2: 4895 // If the explicit instantiation is for a class or member class, the 4896 // elaborated-type-specifier in the declaration shall include a 4897 // simple-template-id. 4898 // 4899 // C++98 has the same restriction, just worded differently. 4900 if (!ScopeSpecifierHasTemplateId(SS)) 4901 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id) 4902 << Record << SS.getRange(); 4903 4904 // C++0x [temp.explicit]p2: 4905 // There are two forms of explicit instantiation: an explicit instantiation 4906 // definition and an explicit instantiation declaration. An explicit 4907 // instantiation declaration begins with the extern keyword. [...] 4908 TemplateSpecializationKind TSK 4909 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4910 : TSK_ExplicitInstantiationDeclaration; 4911 4912 // C++0x [temp.explicit]p2: 4913 // [...] An explicit instantiation shall appear in an enclosing 4914 // namespace of its template. [...] 4915 // 4916 // This is C++ DR 275. 4917 CheckExplicitInstantiationScope(*this, Record, NameLoc, true); 4918 4919 // Verify that it is okay to explicitly instantiate here. 4920 CXXRecordDecl *PrevDecl 4921 = cast_or_null<CXXRecordDecl>(Record->getPreviousDeclaration()); 4922 if (!PrevDecl && Record->getDefinition()) 4923 PrevDecl = Record; 4924 if (PrevDecl) { 4925 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo(); 4926 bool HasNoEffect = false; 4927 assert(MSInfo && "No member specialization information?"); 4928 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK, 4929 PrevDecl, 4930 MSInfo->getTemplateSpecializationKind(), 4931 MSInfo->getPointOfInstantiation(), 4932 HasNoEffect)) 4933 return true; 4934 if (HasNoEffect) 4935 return TagD; 4936 } 4937 4938 CXXRecordDecl *RecordDef 4939 = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 4940 if (!RecordDef) { 4941 // C++ [temp.explicit]p3: 4942 // A definition of a member class of a class template shall be in scope 4943 // at the point of an explicit instantiation of the member class. 4944 CXXRecordDecl *Def 4945 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition()); 4946 if (!Def) { 4947 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member) 4948 << 0 << Record->getDeclName() << Record->getDeclContext(); 4949 Diag(Pattern->getLocation(), diag::note_forward_declaration) 4950 << Pattern; 4951 return true; 4952 } else { 4953 if (InstantiateClass(NameLoc, Record, Def, 4954 getTemplateInstantiationArgs(Record), 4955 TSK)) 4956 return true; 4957 4958 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 4959 if (!RecordDef) 4960 return true; 4961 } 4962 } 4963 4964 // Instantiate all of the members of the class. 4965 InstantiateClassMembers(NameLoc, RecordDef, 4966 getTemplateInstantiationArgs(Record), TSK); 4967 4968 if (TSK == TSK_ExplicitInstantiationDefinition) 4969 MarkVTableUsed(NameLoc, RecordDef, true); 4970 4971 // FIXME: We don't have any representation for explicit instantiations of 4972 // member classes. Such a representation is not needed for compilation, but it 4973 // should be available for clients that want to see all of the declarations in 4974 // the source code. 4975 return TagD; 4976} 4977 4978DeclResult Sema::ActOnExplicitInstantiation(Scope *S, 4979 SourceLocation ExternLoc, 4980 SourceLocation TemplateLoc, 4981 Declarator &D) { 4982 // Explicit instantiations always require a name. 4983 // TODO: check if/when DNInfo should replace Name. 4984 DeclarationNameInfo NameInfo = GetNameForDeclarator(D); 4985 DeclarationName Name = NameInfo.getName(); 4986 if (!Name) { 4987 if (!D.isInvalidType()) 4988 Diag(D.getDeclSpec().getSourceRange().getBegin(), 4989 diag::err_explicit_instantiation_requires_name) 4990 << D.getDeclSpec().getSourceRange() 4991 << D.getSourceRange(); 4992 4993 return true; 4994 } 4995 4996 // The scope passed in may not be a decl scope. Zip up the scope tree until 4997 // we find one that is. 4998 while ((S->getFlags() & Scope::DeclScope) == 0 || 4999 (S->getFlags() & Scope::TemplateParamScope) != 0) 5000 S = S->getParent(); 5001 5002 // Determine the type of the declaration. 5003 TypeSourceInfo *T = GetTypeForDeclarator(D, S); 5004 QualType R = T->getType(); 5005 if (R.isNull()) 5006 return true; 5007 5008 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 5009 // Cannot explicitly instantiate a typedef. 5010 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef) 5011 << Name; 5012 return true; 5013 } 5014 5015 // C++0x [temp.explicit]p1: 5016 // [...] An explicit instantiation of a function template shall not use the 5017 // inline or constexpr specifiers. 5018 // Presumably, this also applies to member functions of class templates as 5019 // well. 5020 if (D.getDeclSpec().isInlineSpecified() && getLangOptions().CPlusPlus0x) 5021 Diag(D.getDeclSpec().getInlineSpecLoc(), 5022 diag::err_explicit_instantiation_inline) 5023 <<FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); 5024 5025 // FIXME: check for constexpr specifier. 5026 5027 // C++0x [temp.explicit]p2: 5028 // There are two forms of explicit instantiation: an explicit instantiation 5029 // definition and an explicit instantiation declaration. An explicit 5030 // instantiation declaration begins with the extern keyword. [...] 5031 TemplateSpecializationKind TSK 5032 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 5033 : TSK_ExplicitInstantiationDeclaration; 5034 5035 LookupResult Previous(*this, NameInfo, LookupOrdinaryName); 5036 LookupParsedName(Previous, S, &D.getCXXScopeSpec()); 5037 5038 if (!R->isFunctionType()) { 5039 // C++ [temp.explicit]p1: 5040 // A [...] static data member of a class template can be explicitly 5041 // instantiated from the member definition associated with its class 5042 // template. 5043 if (Previous.isAmbiguous()) 5044 return true; 5045 5046 VarDecl *Prev = Previous.getAsSingle<VarDecl>(); 5047 if (!Prev || !Prev->isStaticDataMember()) { 5048 // We expect to see a data data member here. 5049 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known) 5050 << Name; 5051 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5052 P != PEnd; ++P) 5053 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here); 5054 return true; 5055 } 5056 5057 if (!Prev->getInstantiatedFromStaticDataMember()) { 5058 // FIXME: Check for explicit specialization? 5059 Diag(D.getIdentifierLoc(), 5060 diag::err_explicit_instantiation_data_member_not_instantiated) 5061 << Prev; 5062 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here); 5063 // FIXME: Can we provide a note showing where this was declared? 5064 return true; 5065 } 5066 5067 // C++0x [temp.explicit]p2: 5068 // If the explicit instantiation is for a member function, a member class 5069 // or a static data member of a class template specialization, the name of 5070 // the class template specialization in the qualified-id for the member 5071 // name shall be a simple-template-id. 5072 // 5073 // C++98 has the same restriction, just worded differently. 5074 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5075 Diag(D.getIdentifierLoc(), 5076 diag::ext_explicit_instantiation_without_qualified_id) 5077 << Prev << D.getCXXScopeSpec().getRange(); 5078 5079 // Check the scope of this explicit instantiation. 5080 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true); 5081 5082 // Verify that it is okay to explicitly instantiate here. 5083 MemberSpecializationInfo *MSInfo = Prev->getMemberSpecializationInfo(); 5084 assert(MSInfo && "Missing static data member specialization info?"); 5085 bool HasNoEffect = false; 5086 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev, 5087 MSInfo->getTemplateSpecializationKind(), 5088 MSInfo->getPointOfInstantiation(), 5089 HasNoEffect)) 5090 return true; 5091 if (HasNoEffect) 5092 return (Decl*) 0; 5093 5094 // Instantiate static data member. 5095 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5096 if (TSK == TSK_ExplicitInstantiationDefinition) 5097 InstantiateStaticDataMemberDefinition(D.getIdentifierLoc(), Prev); 5098 5099 // FIXME: Create an ExplicitInstantiation node? 5100 return (Decl*) 0; 5101 } 5102 5103 // If the declarator is a template-id, translate the parser's template 5104 // argument list into our AST format. 5105 bool HasExplicitTemplateArgs = false; 5106 TemplateArgumentListInfo TemplateArgs; 5107 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 5108 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 5109 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); 5110 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); 5111 ASTTemplateArgsPtr TemplateArgsPtr(*this, 5112 TemplateId->getTemplateArgs(), 5113 TemplateId->NumArgs); 5114 translateTemplateArguments(TemplateArgsPtr, TemplateArgs); 5115 HasExplicitTemplateArgs = true; 5116 TemplateArgsPtr.release(); 5117 } 5118 5119 // C++ [temp.explicit]p1: 5120 // A [...] function [...] can be explicitly instantiated from its template. 5121 // A member function [...] of a class template can be explicitly 5122 // instantiated from the member definition associated with its class 5123 // template. 5124 UnresolvedSet<8> Matches; 5125 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5126 P != PEnd; ++P) { 5127 NamedDecl *Prev = *P; 5128 if (!HasExplicitTemplateArgs) { 5129 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) { 5130 if (Context.hasSameUnqualifiedType(Method->getType(), R)) { 5131 Matches.clear(); 5132 5133 Matches.addDecl(Method, P.getAccess()); 5134 if (Method->getTemplateSpecializationKind() == TSK_Undeclared) 5135 break; 5136 } 5137 } 5138 } 5139 5140 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev); 5141 if (!FunTmpl) 5142 continue; 5143 5144 TemplateDeductionInfo Info(Context, D.getIdentifierLoc()); 5145 FunctionDecl *Specialization = 0; 5146 if (TemplateDeductionResult TDK 5147 = DeduceTemplateArguments(FunTmpl, 5148 (HasExplicitTemplateArgs ? &TemplateArgs : 0), 5149 R, Specialization, Info)) { 5150 // FIXME: Keep track of almost-matches? 5151 (void)TDK; 5152 continue; 5153 } 5154 5155 Matches.addDecl(Specialization, P.getAccess()); 5156 } 5157 5158 // Find the most specialized function template specialization. 5159 UnresolvedSetIterator Result 5160 = getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other, 5161 D.getIdentifierLoc(), 5162 PDiag(diag::err_explicit_instantiation_not_known) << Name, 5163 PDiag(diag::err_explicit_instantiation_ambiguous) << Name, 5164 PDiag(diag::note_explicit_instantiation_candidate)); 5165 5166 if (Result == Matches.end()) 5167 return true; 5168 5169 // Ignore access control bits, we don't need them for redeclaration checking. 5170 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 5171 5172 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) { 5173 Diag(D.getIdentifierLoc(), 5174 diag::err_explicit_instantiation_member_function_not_instantiated) 5175 << Specialization 5176 << (Specialization->getTemplateSpecializationKind() == 5177 TSK_ExplicitSpecialization); 5178 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here); 5179 return true; 5180 } 5181 5182 FunctionDecl *PrevDecl = Specialization->getPreviousDeclaration(); 5183 if (!PrevDecl && Specialization->isThisDeclarationADefinition()) 5184 PrevDecl = Specialization; 5185 5186 if (PrevDecl) { 5187 bool HasNoEffect = false; 5188 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, 5189 PrevDecl, 5190 PrevDecl->getTemplateSpecializationKind(), 5191 PrevDecl->getPointOfInstantiation(), 5192 HasNoEffect)) 5193 return true; 5194 5195 // FIXME: We may still want to build some representation of this 5196 // explicit specialization. 5197 if (HasNoEffect) 5198 return (Decl*) 0; 5199 } 5200 5201 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5202 5203 if (TSK == TSK_ExplicitInstantiationDefinition) 5204 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization); 5205 5206 // C++0x [temp.explicit]p2: 5207 // If the explicit instantiation is for a member function, a member class 5208 // or a static data member of a class template specialization, the name of 5209 // the class template specialization in the qualified-id for the member 5210 // name shall be a simple-template-id. 5211 // 5212 // C++98 has the same restriction, just worded differently. 5213 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate(); 5214 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl && 5215 D.getCXXScopeSpec().isSet() && 5216 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5217 Diag(D.getIdentifierLoc(), 5218 diag::ext_explicit_instantiation_without_qualified_id) 5219 << Specialization << D.getCXXScopeSpec().getRange(); 5220 5221 CheckExplicitInstantiationScope(*this, 5222 FunTmpl? (NamedDecl *)FunTmpl 5223 : Specialization->getInstantiatedFromMemberFunction(), 5224 D.getIdentifierLoc(), 5225 D.getCXXScopeSpec().isSet()); 5226 5227 // FIXME: Create some kind of ExplicitInstantiationDecl here. 5228 return (Decl*) 0; 5229} 5230 5231TypeResult 5232Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 5233 const CXXScopeSpec &SS, IdentifierInfo *Name, 5234 SourceLocation TagLoc, SourceLocation NameLoc) { 5235 // This has to hold, because SS is expected to be defined. 5236 assert(Name && "Expected a name in a dependent tag"); 5237 5238 NestedNameSpecifier *NNS 5239 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5240 if (!NNS) 5241 return true; 5242 5243 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 5244 5245 if (TUK == TUK_Declaration || TUK == TUK_Definition) { 5246 Diag(NameLoc, diag::err_dependent_tag_decl) 5247 << (TUK == TUK_Definition) << Kind << SS.getRange(); 5248 return true; 5249 } 5250 5251 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 5252 return ParsedType::make(Context.getDependentNameType(Kwd, NNS, Name)); 5253} 5254 5255TypeResult 5256Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5257 const CXXScopeSpec &SS, const IdentifierInfo &II, 5258 SourceLocation IdLoc) { 5259 NestedNameSpecifier *NNS 5260 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5261 if (!NNS) 5262 return true; 5263 5264 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5265 !getLangOptions().CPlusPlus0x) 5266 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5267 << FixItHint::CreateRemoval(TypenameLoc); 5268 5269 QualType T = CheckTypenameType(ETK_Typename, NNS, II, 5270 TypenameLoc, SS.getRange(), IdLoc); 5271 if (T.isNull()) 5272 return true; 5273 5274 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5275 if (isa<DependentNameType>(T)) { 5276 DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc()); 5277 TL.setKeywordLoc(TypenameLoc); 5278 TL.setQualifierRange(SS.getRange()); 5279 TL.setNameLoc(IdLoc); 5280 } else { 5281 ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc()); 5282 TL.setKeywordLoc(TypenameLoc); 5283 TL.setQualifierRange(SS.getRange()); 5284 cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(IdLoc); 5285 } 5286 5287 return CreateParsedType(T, TSI); 5288} 5289 5290TypeResult 5291Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5292 const CXXScopeSpec &SS, SourceLocation TemplateLoc, 5293 ParsedType Ty) { 5294 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5295 !getLangOptions().CPlusPlus0x) 5296 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5297 << FixItHint::CreateRemoval(TypenameLoc); 5298 5299 TypeSourceInfo *InnerTSI = 0; 5300 QualType T = GetTypeFromParser(Ty, &InnerTSI); 5301 5302 assert(isa<TemplateSpecializationType>(T) && 5303 "Expected a template specialization type"); 5304 5305 if (computeDeclContext(SS, false)) { 5306 // If we can compute a declaration context, then the "typename" 5307 // keyword was superfluous. Just build an ElaboratedType to keep 5308 // track of the nested-name-specifier. 5309 5310 // Push the inner type, preserving its source locations if possible. 5311 TypeLocBuilder Builder; 5312 if (InnerTSI) 5313 Builder.pushFullCopy(InnerTSI->getTypeLoc()); 5314 else 5315 Builder.push<TemplateSpecializationTypeLoc>(T).initialize(TemplateLoc); 5316 5317 /* Note: NNS already embedded in template specialization type T. */ 5318 T = Context.getElaboratedType(ETK_Typename, /*NNS=*/0, T); 5319 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T); 5320 TL.setKeywordLoc(TypenameLoc); 5321 TL.setQualifierRange(SS.getRange()); 5322 5323 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T); 5324 return CreateParsedType(T, TSI); 5325 } 5326 5327 // TODO: it's really silly that we make a template specialization 5328 // type earlier only to drop it again here. 5329 TemplateSpecializationType *TST = cast<TemplateSpecializationType>(T); 5330 DependentTemplateName *DTN = 5331 TST->getTemplateName().getAsDependentTemplateName(); 5332 assert(DTN && "dependent template has non-dependent name?"); 5333 assert(DTN->getQualifier() 5334 == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); 5335 T = Context.getDependentTemplateSpecializationType(ETK_Typename, 5336 DTN->getQualifier(), 5337 DTN->getIdentifier(), 5338 TST->getNumArgs(), 5339 TST->getArgs()); 5340 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5341 DependentTemplateSpecializationTypeLoc TL = 5342 cast<DependentTemplateSpecializationTypeLoc>(TSI->getTypeLoc()); 5343 if (InnerTSI) { 5344 TemplateSpecializationTypeLoc TSTL = 5345 cast<TemplateSpecializationTypeLoc>(InnerTSI->getTypeLoc()); 5346 TL.setLAngleLoc(TSTL.getLAngleLoc()); 5347 TL.setRAngleLoc(TSTL.getRAngleLoc()); 5348 for (unsigned I = 0, E = TST->getNumArgs(); I != E; ++I) 5349 TL.setArgLocInfo(I, TSTL.getArgLocInfo(I)); 5350 } else { 5351 TL.initializeLocal(SourceLocation()); 5352 } 5353 TL.setKeywordLoc(TypenameLoc); 5354 TL.setQualifierRange(SS.getRange()); 5355 return CreateParsedType(T, TSI); 5356} 5357 5358/// \brief Build the type that describes a C++ typename specifier, 5359/// e.g., "typename T::type". 5360QualType 5361Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword, 5362 NestedNameSpecifier *NNS, const IdentifierInfo &II, 5363 SourceLocation KeywordLoc, SourceRange NNSRange, 5364 SourceLocation IILoc) { 5365 CXXScopeSpec SS; 5366 SS.setScopeRep(NNS); 5367 SS.setRange(NNSRange); 5368 5369 DeclContext *Ctx = computeDeclContext(SS); 5370 if (!Ctx) { 5371 // If the nested-name-specifier is dependent and couldn't be 5372 // resolved to a type, build a typename type. 5373 assert(NNS->isDependent()); 5374 return Context.getDependentNameType(Keyword, NNS, &II); 5375 } 5376 5377 // If the nested-name-specifier refers to the current instantiation, 5378 // the "typename" keyword itself is superfluous. In C++03, the 5379 // program is actually ill-formed. However, DR 382 (in C++0x CD1) 5380 // allows such extraneous "typename" keywords, and we retroactively 5381 // apply this DR to C++03 code with only a warning. In any case we continue. 5382 5383 if (RequireCompleteDeclContext(SS, Ctx)) 5384 return QualType(); 5385 5386 DeclarationName Name(&II); 5387 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName); 5388 LookupQualifiedName(Result, Ctx); 5389 unsigned DiagID = 0; 5390 Decl *Referenced = 0; 5391 switch (Result.getResultKind()) { 5392 case LookupResult::NotFound: 5393 DiagID = diag::err_typename_nested_not_found; 5394 break; 5395 5396 case LookupResult::NotFoundInCurrentInstantiation: 5397 // Okay, it's a member of an unknown instantiation. 5398 return Context.getDependentNameType(Keyword, NNS, &II); 5399 5400 case LookupResult::Found: 5401 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) { 5402 // We found a type. Build an ElaboratedType, since the 5403 // typename-specifier was just sugar. 5404 return Context.getElaboratedType(ETK_Typename, NNS, 5405 Context.getTypeDeclType(Type)); 5406 } 5407 5408 DiagID = diag::err_typename_nested_not_type; 5409 Referenced = Result.getFoundDecl(); 5410 break; 5411 5412 case LookupResult::FoundUnresolvedValue: 5413 llvm_unreachable("unresolved using decl in non-dependent context"); 5414 return QualType(); 5415 5416 case LookupResult::FoundOverloaded: 5417 DiagID = diag::err_typename_nested_not_type; 5418 Referenced = *Result.begin(); 5419 break; 5420 5421 case LookupResult::Ambiguous: 5422 return QualType(); 5423 } 5424 5425 // If we get here, it's because name lookup did not find a 5426 // type. Emit an appropriate diagnostic and return an error. 5427 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : NNSRange.getBegin(), 5428 IILoc); 5429 Diag(IILoc, DiagID) << FullRange << Name << Ctx; 5430 if (Referenced) 5431 Diag(Referenced->getLocation(), diag::note_typename_refers_here) 5432 << Name; 5433 return QualType(); 5434} 5435 5436namespace { 5437 // See Sema::RebuildTypeInCurrentInstantiation 5438 class CurrentInstantiationRebuilder 5439 : public TreeTransform<CurrentInstantiationRebuilder> { 5440 SourceLocation Loc; 5441 DeclarationName Entity; 5442 5443 public: 5444 typedef TreeTransform<CurrentInstantiationRebuilder> inherited; 5445 5446 CurrentInstantiationRebuilder(Sema &SemaRef, 5447 SourceLocation Loc, 5448 DeclarationName Entity) 5449 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef), 5450 Loc(Loc), Entity(Entity) { } 5451 5452 /// \brief Determine whether the given type \p T has already been 5453 /// transformed. 5454 /// 5455 /// For the purposes of type reconstruction, a type has already been 5456 /// transformed if it is NULL or if it is not dependent. 5457 bool AlreadyTransformed(QualType T) { 5458 return T.isNull() || !T->isDependentType(); 5459 } 5460 5461 /// \brief Returns the location of the entity whose type is being 5462 /// rebuilt. 5463 SourceLocation getBaseLocation() { return Loc; } 5464 5465 /// \brief Returns the name of the entity whose type is being rebuilt. 5466 DeclarationName getBaseEntity() { return Entity; } 5467 5468 /// \brief Sets the "base" location and entity when that 5469 /// information is known based on another transformation. 5470 void setBase(SourceLocation Loc, DeclarationName Entity) { 5471 this->Loc = Loc; 5472 this->Entity = Entity; 5473 } 5474 }; 5475} 5476 5477/// \brief Rebuilds a type within the context of the current instantiation. 5478/// 5479/// The type \p T is part of the type of an out-of-line member definition of 5480/// a class template (or class template partial specialization) that was parsed 5481/// and constructed before we entered the scope of the class template (or 5482/// partial specialization thereof). This routine will rebuild that type now 5483/// that we have entered the declarator's scope, which may produce different 5484/// canonical types, e.g., 5485/// 5486/// \code 5487/// template<typename T> 5488/// struct X { 5489/// typedef T* pointer; 5490/// pointer data(); 5491/// }; 5492/// 5493/// template<typename T> 5494/// typename X<T>::pointer X<T>::data() { ... } 5495/// \endcode 5496/// 5497/// Here, the type "typename X<T>::pointer" will be created as a DependentNameType, 5498/// since we do not know that we can look into X<T> when we parsed the type. 5499/// This function will rebuild the type, performing the lookup of "pointer" 5500/// in X<T> and returning an ElaboratedType whose canonical type is the same 5501/// as the canonical type of T*, allowing the return types of the out-of-line 5502/// definition and the declaration to match. 5503TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T, 5504 SourceLocation Loc, 5505 DeclarationName Name) { 5506 if (!T || !T->getType()->isDependentType()) 5507 return T; 5508 5509 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name); 5510 return Rebuilder.TransformType(T); 5511} 5512 5513ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) { 5514 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(), 5515 DeclarationName()); 5516 return Rebuilder.TransformExpr(E); 5517} 5518 5519bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) { 5520 if (SS.isInvalid()) return true; 5521 5522 NestedNameSpecifier *NNS = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 5523 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(), 5524 DeclarationName()); 5525 NestedNameSpecifier *Rebuilt = 5526 Rebuilder.TransformNestedNameSpecifier(NNS, SS.getRange()); 5527 if (!Rebuilt) return true; 5528 5529 SS.setScopeRep(Rebuilt); 5530 return false; 5531} 5532 5533/// \brief Produces a formatted string that describes the binding of 5534/// template parameters to template arguments. 5535std::string 5536Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 5537 const TemplateArgumentList &Args) { 5538 // FIXME: For variadic templates, we'll need to get the structured list. 5539 return getTemplateArgumentBindingsText(Params, Args.getFlatArgumentList(), 5540 Args.flat_size()); 5541} 5542 5543std::string 5544Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 5545 const TemplateArgument *Args, 5546 unsigned NumArgs) { 5547 std::string Result; 5548 5549 if (!Params || Params->size() == 0 || NumArgs == 0) 5550 return Result; 5551 5552 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 5553 if (I >= NumArgs) 5554 break; 5555 5556 if (I == 0) 5557 Result += "[with "; 5558 else 5559 Result += ", "; 5560 5561 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) { 5562 Result += Id->getName(); 5563 } else { 5564 Result += '$'; 5565 Result += llvm::utostr(I); 5566 } 5567 5568 Result += " = "; 5569 5570 switch (Args[I].getKind()) { 5571 case TemplateArgument::Null: 5572 Result += "<no value>"; 5573 break; 5574 5575 case TemplateArgument::Type: { 5576 std::string TypeStr; 5577 Args[I].getAsType().getAsStringInternal(TypeStr, 5578 Context.PrintingPolicy); 5579 Result += TypeStr; 5580 break; 5581 } 5582 5583 case TemplateArgument::Declaration: { 5584 bool Unnamed = true; 5585 if (NamedDecl *ND = dyn_cast_or_null<NamedDecl>(Args[I].getAsDecl())) { 5586 if (ND->getDeclName()) { 5587 Unnamed = false; 5588 Result += ND->getNameAsString(); 5589 } 5590 } 5591 5592 if (Unnamed) { 5593 Result += "<anonymous>"; 5594 } 5595 break; 5596 } 5597 5598 case TemplateArgument::Template: { 5599 std::string Str; 5600 llvm::raw_string_ostream OS(Str); 5601 Args[I].getAsTemplate().print(OS, Context.PrintingPolicy); 5602 Result += OS.str(); 5603 break; 5604 } 5605 5606 case TemplateArgument::Integral: { 5607 Result += Args[I].getAsIntegral()->toString(10); 5608 break; 5609 } 5610 5611 case TemplateArgument::Expression: { 5612 // FIXME: This is non-optimal, since we're regurgitating the 5613 // expression we were given. 5614 std::string Str; 5615 { 5616 llvm::raw_string_ostream OS(Str); 5617 Args[I].getAsExpr()->printPretty(OS, Context, 0, 5618 Context.PrintingPolicy); 5619 } 5620 Result += Str; 5621 break; 5622 } 5623 5624 case TemplateArgument::Pack: 5625 // FIXME: Format template argument packs 5626 Result += "<template argument pack>"; 5627 break; 5628 } 5629 } 5630 5631 Result += ']'; 5632 return Result; 5633} 5634