SemaTemplate.cpp revision ff3f7ef339ee1c531015fbd17016013d469d538f
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 // Silently drop template member friend declarations. 1379 // TODO: implement these 1380 if (IsFriend && NumParamLists) Invalid = true; 1381 1382 return 0; 1383 } 1384 1385 // If there were too many template parameter lists, complain about that now. 1386 if (Idx != NumParamLists - 1) { 1387 while (Idx < NumParamLists - 1) { 1388 bool isExplicitSpecHeader = ParamLists[Idx]->size() == 0; 1389 Diag(ParamLists[Idx]->getTemplateLoc(), 1390 isExplicitSpecHeader? diag::warn_template_spec_extra_headers 1391 : diag::err_template_spec_extra_headers) 1392 << SourceRange(ParamLists[Idx]->getTemplateLoc(), 1393 ParamLists[Idx]->getRAngleLoc()); 1394 1395 if (isExplicitSpecHeader && !ExplicitSpecializationsInSpecifier.empty()) { 1396 Diag(ExplicitSpecializationsInSpecifier.back()->getLocation(), 1397 diag::note_explicit_template_spec_does_not_need_header) 1398 << ExplicitSpecializationsInSpecifier.back(); 1399 ExplicitSpecializationsInSpecifier.pop_back(); 1400 } 1401 1402 // We have a template parameter list with no corresponding scope, which 1403 // means that the resulting template declaration can't be instantiated 1404 // properly (we'll end up with dependent nodes when we shouldn't). 1405 if (!isExplicitSpecHeader) 1406 Invalid = true; 1407 1408 ++Idx; 1409 } 1410 } 1411 1412 // Silently drop template member template friend declarations. 1413 // TODO: implement these 1414 if (IsFriend && NumParamLists > 1) 1415 Invalid = true; 1416 1417 // Return the last template parameter list, which corresponds to the 1418 // entity being declared. 1419 return ParamLists[NumParamLists - 1]; 1420} 1421 1422QualType Sema::CheckTemplateIdType(TemplateName Name, 1423 SourceLocation TemplateLoc, 1424 const TemplateArgumentListInfo &TemplateArgs) { 1425 TemplateDecl *Template = Name.getAsTemplateDecl(); 1426 if (!Template) { 1427 // The template name does not resolve to a template, so we just 1428 // build a dependent template-id type. 1429 return Context.getTemplateSpecializationType(Name, TemplateArgs); 1430 } 1431 1432 // Check that the template argument list is well-formed for this 1433 // template. 1434 TemplateArgumentListBuilder Converted(Template->getTemplateParameters(), 1435 TemplateArgs.size()); 1436 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs, 1437 false, Converted)) 1438 return QualType(); 1439 1440 assert((Converted.structuredSize() == 1441 Template->getTemplateParameters()->size()) && 1442 "Converted template argument list is too short!"); 1443 1444 QualType CanonType; 1445 1446 if (Name.isDependent() || 1447 TemplateSpecializationType::anyDependentTemplateArguments( 1448 TemplateArgs)) { 1449 // This class template specialization is a dependent 1450 // type. Therefore, its canonical type is another class template 1451 // specialization type that contains all of the converted 1452 // arguments in canonical form. This ensures that, e.g., A<T> and 1453 // A<T, T> have identical types when A is declared as: 1454 // 1455 // template<typename T, typename U = T> struct A; 1456 TemplateName CanonName = Context.getCanonicalTemplateName(Name); 1457 CanonType = Context.getTemplateSpecializationType(CanonName, 1458 Converted.getFlatArguments(), 1459 Converted.flatSize()); 1460 1461 // FIXME: CanonType is not actually the canonical type, and unfortunately 1462 // it is a TemplateSpecializationType that we will never use again. 1463 // In the future, we need to teach getTemplateSpecializationType to only 1464 // build the canonical type and return that to us. 1465 CanonType = Context.getCanonicalType(CanonType); 1466 1467 // This might work out to be a current instantiation, in which 1468 // case the canonical type needs to be the InjectedClassNameType. 1469 // 1470 // TODO: in theory this could be a simple hashtable lookup; most 1471 // changes to CurContext don't change the set of current 1472 // instantiations. 1473 if (isa<ClassTemplateDecl>(Template)) { 1474 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { 1475 // If we get out to a namespace, we're done. 1476 if (Ctx->isFileContext()) break; 1477 1478 // If this isn't a record, keep looking. 1479 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx); 1480 if (!Record) continue; 1481 1482 // Look for one of the two cases with InjectedClassNameTypes 1483 // and check whether it's the same template. 1484 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) && 1485 !Record->getDescribedClassTemplate()) 1486 continue; 1487 1488 // Fetch the injected class name type and check whether its 1489 // injected type is equal to the type we just built. 1490 QualType ICNT = Context.getTypeDeclType(Record); 1491 QualType Injected = cast<InjectedClassNameType>(ICNT) 1492 ->getInjectedSpecializationType(); 1493 1494 if (CanonType != Injected->getCanonicalTypeInternal()) 1495 continue; 1496 1497 // If so, the canonical type of this TST is the injected 1498 // class name type of the record we just found. 1499 assert(ICNT.isCanonical()); 1500 CanonType = ICNT; 1501 break; 1502 } 1503 } 1504 } else if (ClassTemplateDecl *ClassTemplate 1505 = dyn_cast<ClassTemplateDecl>(Template)) { 1506 // Find the class template specialization declaration that 1507 // corresponds to these arguments. 1508 void *InsertPos = 0; 1509 ClassTemplateSpecializationDecl *Decl 1510 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 1511 Converted.flatSize(), InsertPos); 1512 if (!Decl) { 1513 // This is the first time we have referenced this class template 1514 // specialization. Create the canonical declaration and add it to 1515 // the set of specializations. 1516 Decl = ClassTemplateSpecializationDecl::Create(Context, 1517 ClassTemplate->getTemplatedDecl()->getTagKind(), 1518 ClassTemplate->getDeclContext(), 1519 ClassTemplate->getLocation(), 1520 ClassTemplate, 1521 Converted, 0); 1522 ClassTemplate->AddSpecialization(Decl, InsertPos); 1523 Decl->setLexicalDeclContext(CurContext); 1524 } 1525 1526 CanonType = Context.getTypeDeclType(Decl); 1527 assert(isa<RecordType>(CanonType) && 1528 "type of non-dependent specialization is not a RecordType"); 1529 } 1530 1531 // Build the fully-sugared type for this class template 1532 // specialization, which refers back to the class template 1533 // specialization we created or found. 1534 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType); 1535} 1536 1537TypeResult 1538Sema::ActOnTemplateIdType(TemplateTy TemplateD, SourceLocation TemplateLoc, 1539 SourceLocation LAngleLoc, 1540 ASTTemplateArgsPtr TemplateArgsIn, 1541 SourceLocation RAngleLoc) { 1542 TemplateName Template = TemplateD.getAsVal<TemplateName>(); 1543 1544 // Translate the parser's template argument list in our AST format. 1545 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 1546 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 1547 1548 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); 1549 TemplateArgsIn.release(); 1550 1551 if (Result.isNull()) 1552 return true; 1553 1554 TypeSourceInfo *DI = Context.CreateTypeSourceInfo(Result); 1555 TemplateSpecializationTypeLoc TL 1556 = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc()); 1557 TL.setTemplateNameLoc(TemplateLoc); 1558 TL.setLAngleLoc(LAngleLoc); 1559 TL.setRAngleLoc(RAngleLoc); 1560 for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i) 1561 TL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 1562 1563 return CreateParsedType(Result, DI); 1564} 1565 1566TypeResult Sema::ActOnTagTemplateIdType(TypeResult TypeResult, 1567 TagUseKind TUK, 1568 TypeSpecifierType TagSpec, 1569 SourceLocation TagLoc) { 1570 if (TypeResult.isInvalid()) 1571 return ::TypeResult(); 1572 1573 // FIXME: preserve source info, ideally without copying the DI. 1574 TypeSourceInfo *DI; 1575 QualType Type = GetTypeFromParser(TypeResult.get(), &DI); 1576 1577 // Verify the tag specifier. 1578 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 1579 1580 if (const RecordType *RT = Type->getAs<RecordType>()) { 1581 RecordDecl *D = RT->getDecl(); 1582 1583 IdentifierInfo *Id = D->getIdentifier(); 1584 assert(Id && "templated class must have an identifier"); 1585 1586 if (!isAcceptableTagRedeclaration(D, TagKind, TagLoc, *Id)) { 1587 Diag(TagLoc, diag::err_use_with_wrong_tag) 1588 << Type 1589 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName()); 1590 Diag(D->getLocation(), diag::note_previous_use); 1591 } 1592 } 1593 1594 ElaboratedTypeKeyword Keyword 1595 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind); 1596 QualType ElabType = Context.getElaboratedType(Keyword, /*NNS=*/0, Type); 1597 1598 return ParsedType::make(ElabType); 1599} 1600 1601ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, 1602 LookupResult &R, 1603 bool RequiresADL, 1604 const TemplateArgumentListInfo &TemplateArgs) { 1605 // FIXME: Can we do any checking at this point? I guess we could check the 1606 // template arguments that we have against the template name, if the template 1607 // name refers to a single template. That's not a terribly common case, 1608 // though. 1609 1610 // These should be filtered out by our callers. 1611 assert(!R.empty() && "empty lookup results when building templateid"); 1612 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid"); 1613 1614 NestedNameSpecifier *Qualifier = 0; 1615 SourceRange QualifierRange; 1616 if (SS.isSet()) { 1617 Qualifier = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 1618 QualifierRange = SS.getRange(); 1619 } 1620 1621 // We don't want lookup warnings at this point. 1622 R.suppressDiagnostics(); 1623 1624 bool Dependent 1625 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 1626 &TemplateArgs); 1627 UnresolvedLookupExpr *ULE 1628 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1629 Qualifier, QualifierRange, 1630 R.getLookupNameInfo(), 1631 RequiresADL, TemplateArgs, 1632 R.begin(), R.end()); 1633 1634 return Owned(ULE); 1635} 1636 1637// We actually only call this from template instantiation. 1638ExprResult 1639Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, 1640 const DeclarationNameInfo &NameInfo, 1641 const TemplateArgumentListInfo &TemplateArgs) { 1642 DeclContext *DC; 1643 if (!(DC = computeDeclContext(SS, false)) || 1644 DC->isDependentContext() || 1645 RequireCompleteDeclContext(SS, DC)) 1646 return BuildDependentDeclRefExpr(SS, NameInfo, &TemplateArgs); 1647 1648 bool MemberOfUnknownSpecialization; 1649 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1650 LookupTemplateName(R, (Scope*) 0, SS, QualType(), /*Entering*/ false, 1651 MemberOfUnknownSpecialization); 1652 1653 if (R.isAmbiguous()) 1654 return ExprError(); 1655 1656 if (R.empty()) { 1657 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template) 1658 << NameInfo.getName() << SS.getRange(); 1659 return ExprError(); 1660 } 1661 1662 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) { 1663 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template) 1664 << (NestedNameSpecifier*) SS.getScopeRep() 1665 << NameInfo.getName() << SS.getRange(); 1666 Diag(Temp->getLocation(), diag::note_referenced_class_template); 1667 return ExprError(); 1668 } 1669 1670 return BuildTemplateIdExpr(SS, R, /* ADL */ false, TemplateArgs); 1671} 1672 1673/// \brief Form a dependent template name. 1674/// 1675/// This action forms a dependent template name given the template 1676/// name and its (presumably dependent) scope specifier. For 1677/// example, given "MetaFun::template apply", the scope specifier \p 1678/// SS will be "MetaFun::", \p TemplateKWLoc contains the location 1679/// of the "template" keyword, and "apply" is the \p Name. 1680TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S, 1681 SourceLocation TemplateKWLoc, 1682 CXXScopeSpec &SS, 1683 UnqualifiedId &Name, 1684 ParsedType ObjectType, 1685 bool EnteringContext, 1686 TemplateTy &Result) { 1687 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent() && 1688 !getLangOptions().CPlusPlus0x) 1689 Diag(TemplateKWLoc, diag::ext_template_outside_of_template) 1690 << FixItHint::CreateRemoval(TemplateKWLoc); 1691 1692 DeclContext *LookupCtx = 0; 1693 if (SS.isSet()) 1694 LookupCtx = computeDeclContext(SS, EnteringContext); 1695 if (!LookupCtx && ObjectType) 1696 LookupCtx = computeDeclContext(ObjectType.get()); 1697 if (LookupCtx) { 1698 // C++0x [temp.names]p5: 1699 // If a name prefixed by the keyword template is not the name of 1700 // a template, the program is ill-formed. [Note: the keyword 1701 // template may not be applied to non-template members of class 1702 // templates. -end note ] [ Note: as is the case with the 1703 // typename prefix, the template prefix is allowed in cases 1704 // where it is not strictly necessary; i.e., when the 1705 // nested-name-specifier or the expression on the left of the -> 1706 // or . is not dependent on a template-parameter, or the use 1707 // does not appear in the scope of a template. -end note] 1708 // 1709 // Note: C++03 was more strict here, because it banned the use of 1710 // the "template" keyword prior to a template-name that was not a 1711 // dependent name. C++ DR468 relaxed this requirement (the 1712 // "template" keyword is now permitted). We follow the C++0x 1713 // rules, even in C++03 mode with a warning, retroactively applying the DR. 1714 bool MemberOfUnknownSpecialization; 1715 TemplateNameKind TNK = isTemplateName(0, SS, TemplateKWLoc.isValid(), Name, 1716 ObjectType, EnteringContext, Result, 1717 MemberOfUnknownSpecialization); 1718 if (TNK == TNK_Non_template && LookupCtx->isDependentContext() && 1719 isa<CXXRecordDecl>(LookupCtx) && 1720 cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()) { 1721 // This is a dependent template. Handle it below. 1722 } else if (TNK == TNK_Non_template) { 1723 Diag(Name.getSourceRange().getBegin(), 1724 diag::err_template_kw_refers_to_non_template) 1725 << GetNameFromUnqualifiedId(Name).getName() 1726 << Name.getSourceRange() 1727 << TemplateKWLoc; 1728 return TNK_Non_template; 1729 } else { 1730 // We found something; return it. 1731 return TNK; 1732 } 1733 } 1734 1735 NestedNameSpecifier *Qualifier 1736 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 1737 1738 switch (Name.getKind()) { 1739 case UnqualifiedId::IK_Identifier: 1740 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1741 Name.Identifier)); 1742 return TNK_Dependent_template_name; 1743 1744 case UnqualifiedId::IK_OperatorFunctionId: 1745 Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1746 Name.OperatorFunctionId.Operator)); 1747 return TNK_Dependent_template_name; 1748 1749 case UnqualifiedId::IK_LiteralOperatorId: 1750 assert(false && "We don't support these; Parse shouldn't have allowed propagation"); 1751 1752 default: 1753 break; 1754 } 1755 1756 Diag(Name.getSourceRange().getBegin(), 1757 diag::err_template_kw_refers_to_non_template) 1758 << GetNameFromUnqualifiedId(Name).getName() 1759 << Name.getSourceRange() 1760 << TemplateKWLoc; 1761 return TNK_Non_template; 1762} 1763 1764bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, 1765 const TemplateArgumentLoc &AL, 1766 TemplateArgumentListBuilder &Converted) { 1767 const TemplateArgument &Arg = AL.getArgument(); 1768 1769 // Check template type parameter. 1770 switch(Arg.getKind()) { 1771 case TemplateArgument::Type: 1772 // C++ [temp.arg.type]p1: 1773 // A template-argument for a template-parameter which is a 1774 // type shall be a type-id. 1775 break; 1776 case TemplateArgument::Template: { 1777 // We have a template type parameter but the template argument 1778 // is a template without any arguments. 1779 SourceRange SR = AL.getSourceRange(); 1780 TemplateName Name = Arg.getAsTemplate(); 1781 Diag(SR.getBegin(), diag::err_template_missing_args) 1782 << Name << SR; 1783 if (TemplateDecl *Decl = Name.getAsTemplateDecl()) 1784 Diag(Decl->getLocation(), diag::note_template_decl_here); 1785 1786 return true; 1787 } 1788 default: { 1789 // We have a template type parameter but the template argument 1790 // is not a type. 1791 SourceRange SR = AL.getSourceRange(); 1792 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; 1793 Diag(Param->getLocation(), diag::note_template_param_here); 1794 1795 return true; 1796 } 1797 } 1798 1799 if (CheckTemplateArgument(Param, AL.getTypeSourceInfo())) 1800 return true; 1801 1802 // Add the converted template type argument. 1803 Converted.Append( 1804 TemplateArgument(Context.getCanonicalType(Arg.getAsType()))); 1805 return false; 1806} 1807 1808/// \brief Substitute template arguments into the default template argument for 1809/// the given template type parameter. 1810/// 1811/// \param SemaRef the semantic analysis object for which we are performing 1812/// the substitution. 1813/// 1814/// \param Template the template that we are synthesizing template arguments 1815/// for. 1816/// 1817/// \param TemplateLoc the location of the template name that started the 1818/// template-id we are checking. 1819/// 1820/// \param RAngleLoc the location of the right angle bracket ('>') that 1821/// terminates the template-id. 1822/// 1823/// \param Param the template template parameter whose default we are 1824/// substituting into. 1825/// 1826/// \param Converted the list of template arguments provided for template 1827/// parameters that precede \p Param in the template parameter list. 1828/// 1829/// \returns the substituted template argument, or NULL if an error occurred. 1830static TypeSourceInfo * 1831SubstDefaultTemplateArgument(Sema &SemaRef, 1832 TemplateDecl *Template, 1833 SourceLocation TemplateLoc, 1834 SourceLocation RAngleLoc, 1835 TemplateTypeParmDecl *Param, 1836 TemplateArgumentListBuilder &Converted) { 1837 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo(); 1838 1839 // If the argument type is dependent, instantiate it now based 1840 // on the previously-computed template arguments. 1841 if (ArgType->getType()->isDependentType()) { 1842 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1843 /*TakeArgs=*/false); 1844 1845 MultiLevelTemplateArgumentList AllTemplateArgs 1846 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1847 1848 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1849 Template, Converted.getFlatArguments(), 1850 Converted.flatSize(), 1851 SourceRange(TemplateLoc, RAngleLoc)); 1852 1853 ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs, 1854 Param->getDefaultArgumentLoc(), 1855 Param->getDeclName()); 1856 } 1857 1858 return ArgType; 1859} 1860 1861/// \brief Substitute template arguments into the default template argument for 1862/// the given non-type template parameter. 1863/// 1864/// \param SemaRef the semantic analysis object for which we are performing 1865/// the substitution. 1866/// 1867/// \param Template the template that we are synthesizing template arguments 1868/// for. 1869/// 1870/// \param TemplateLoc the location of the template name that started the 1871/// template-id we are checking. 1872/// 1873/// \param RAngleLoc the location of the right angle bracket ('>') that 1874/// terminates the template-id. 1875/// 1876/// \param Param the non-type template parameter whose default we are 1877/// substituting into. 1878/// 1879/// \param Converted the list of template arguments provided for template 1880/// parameters that precede \p Param in the template parameter list. 1881/// 1882/// \returns the substituted template argument, or NULL if an error occurred. 1883static ExprResult 1884SubstDefaultTemplateArgument(Sema &SemaRef, 1885 TemplateDecl *Template, 1886 SourceLocation TemplateLoc, 1887 SourceLocation RAngleLoc, 1888 NonTypeTemplateParmDecl *Param, 1889 TemplateArgumentListBuilder &Converted) { 1890 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1891 /*TakeArgs=*/false); 1892 1893 MultiLevelTemplateArgumentList AllTemplateArgs 1894 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1895 1896 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1897 Template, Converted.getFlatArguments(), 1898 Converted.flatSize(), 1899 SourceRange(TemplateLoc, RAngleLoc)); 1900 1901 return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs); 1902} 1903 1904/// \brief Substitute template arguments into the default template argument for 1905/// the given template template parameter. 1906/// 1907/// \param SemaRef the semantic analysis object for which we are performing 1908/// the substitution. 1909/// 1910/// \param Template the template that we are synthesizing template arguments 1911/// for. 1912/// 1913/// \param TemplateLoc the location of the template name that started the 1914/// template-id we are checking. 1915/// 1916/// \param RAngleLoc the location of the right angle bracket ('>') that 1917/// terminates the template-id. 1918/// 1919/// \param Param the template template parameter whose default we are 1920/// substituting into. 1921/// 1922/// \param Converted the list of template arguments provided for template 1923/// parameters that precede \p Param in the template parameter list. 1924/// 1925/// \returns the substituted template argument, or NULL if an error occurred. 1926static TemplateName 1927SubstDefaultTemplateArgument(Sema &SemaRef, 1928 TemplateDecl *Template, 1929 SourceLocation TemplateLoc, 1930 SourceLocation RAngleLoc, 1931 TemplateTemplateParmDecl *Param, 1932 TemplateArgumentListBuilder &Converted) { 1933 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1934 /*TakeArgs=*/false); 1935 1936 MultiLevelTemplateArgumentList AllTemplateArgs 1937 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1938 1939 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1940 Template, Converted.getFlatArguments(), 1941 Converted.flatSize(), 1942 SourceRange(TemplateLoc, RAngleLoc)); 1943 1944 return SemaRef.SubstTemplateName( 1945 Param->getDefaultArgument().getArgument().getAsTemplate(), 1946 Param->getDefaultArgument().getTemplateNameLoc(), 1947 AllTemplateArgs); 1948} 1949 1950/// \brief If the given template parameter has a default template 1951/// argument, substitute into that default template argument and 1952/// return the corresponding template argument. 1953TemplateArgumentLoc 1954Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template, 1955 SourceLocation TemplateLoc, 1956 SourceLocation RAngleLoc, 1957 Decl *Param, 1958 TemplateArgumentListBuilder &Converted) { 1959 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) { 1960 if (!TypeParm->hasDefaultArgument()) 1961 return TemplateArgumentLoc(); 1962 1963 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template, 1964 TemplateLoc, 1965 RAngleLoc, 1966 TypeParm, 1967 Converted); 1968 if (DI) 1969 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI); 1970 1971 return TemplateArgumentLoc(); 1972 } 1973 1974 if (NonTypeTemplateParmDecl *NonTypeParm 1975 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 1976 if (!NonTypeParm->hasDefaultArgument()) 1977 return TemplateArgumentLoc(); 1978 1979 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template, 1980 TemplateLoc, 1981 RAngleLoc, 1982 NonTypeParm, 1983 Converted); 1984 if (Arg.isInvalid()) 1985 return TemplateArgumentLoc(); 1986 1987 Expr *ArgE = Arg.takeAs<Expr>(); 1988 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE); 1989 } 1990 1991 TemplateTemplateParmDecl *TempTempParm 1992 = cast<TemplateTemplateParmDecl>(Param); 1993 if (!TempTempParm->hasDefaultArgument()) 1994 return TemplateArgumentLoc(); 1995 1996 TemplateName TName = SubstDefaultTemplateArgument(*this, Template, 1997 TemplateLoc, 1998 RAngleLoc, 1999 TempTempParm, 2000 Converted); 2001 if (TName.isNull()) 2002 return TemplateArgumentLoc(); 2003 2004 return TemplateArgumentLoc(TemplateArgument(TName), 2005 TempTempParm->getDefaultArgument().getTemplateQualifierRange(), 2006 TempTempParm->getDefaultArgument().getTemplateNameLoc()); 2007} 2008 2009/// \brief Check that the given template argument corresponds to the given 2010/// template parameter. 2011bool Sema::CheckTemplateArgument(NamedDecl *Param, 2012 const TemplateArgumentLoc &Arg, 2013 TemplateDecl *Template, 2014 SourceLocation TemplateLoc, 2015 SourceLocation RAngleLoc, 2016 TemplateArgumentListBuilder &Converted, 2017 CheckTemplateArgumentKind CTAK) { 2018 // Check template type parameters. 2019 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) 2020 return CheckTemplateTypeArgument(TTP, Arg, Converted); 2021 2022 // Check non-type template parameters. 2023 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2024 // Do substitution on the type of the non-type template parameter 2025 // with the template arguments we've seen thus far. 2026 QualType NTTPType = NTTP->getType(); 2027 if (NTTPType->isDependentType()) { 2028 // Do substitution on the type of the non-type template parameter. 2029 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2030 NTTP, Converted.getFlatArguments(), 2031 Converted.flatSize(), 2032 SourceRange(TemplateLoc, RAngleLoc)); 2033 2034 TemplateArgumentList TemplateArgs(Context, Converted, 2035 /*TakeArgs=*/false); 2036 NTTPType = SubstType(NTTPType, 2037 MultiLevelTemplateArgumentList(TemplateArgs), 2038 NTTP->getLocation(), 2039 NTTP->getDeclName()); 2040 // If that worked, check the non-type template parameter type 2041 // for validity. 2042 if (!NTTPType.isNull()) 2043 NTTPType = CheckNonTypeTemplateParameterType(NTTPType, 2044 NTTP->getLocation()); 2045 if (NTTPType.isNull()) 2046 return true; 2047 } 2048 2049 switch (Arg.getArgument().getKind()) { 2050 case TemplateArgument::Null: 2051 assert(false && "Should never see a NULL template argument here"); 2052 return true; 2053 2054 case TemplateArgument::Expression: { 2055 Expr *E = Arg.getArgument().getAsExpr(); 2056 TemplateArgument Result; 2057 if (CheckTemplateArgument(NTTP, NTTPType, E, Result, CTAK)) 2058 return true; 2059 2060 Converted.Append(Result); 2061 break; 2062 } 2063 2064 case TemplateArgument::Declaration: 2065 case TemplateArgument::Integral: 2066 // We've already checked this template argument, so just copy 2067 // it to the list of converted arguments. 2068 Converted.Append(Arg.getArgument()); 2069 break; 2070 2071 case TemplateArgument::Template: 2072 // We were given a template template argument. It may not be ill-formed; 2073 // see below. 2074 if (DependentTemplateName *DTN 2075 = Arg.getArgument().getAsTemplate().getAsDependentTemplateName()) { 2076 // We have a template argument such as \c T::template X, which we 2077 // parsed as a template template argument. However, since we now 2078 // know that we need a non-type template argument, convert this 2079 // template name into an expression. 2080 2081 DeclarationNameInfo NameInfo(DTN->getIdentifier(), 2082 Arg.getTemplateNameLoc()); 2083 2084 Expr *E = DependentScopeDeclRefExpr::Create(Context, 2085 DTN->getQualifier(), 2086 Arg.getTemplateQualifierRange(), 2087 NameInfo); 2088 2089 TemplateArgument Result; 2090 if (CheckTemplateArgument(NTTP, NTTPType, E, Result)) 2091 return true; 2092 2093 Converted.Append(Result); 2094 break; 2095 } 2096 2097 // We have a template argument that actually does refer to a class 2098 // template, template alias, or template template parameter, and 2099 // therefore cannot be a non-type template argument. 2100 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) 2101 << Arg.getSourceRange(); 2102 2103 Diag(Param->getLocation(), diag::note_template_param_here); 2104 return true; 2105 2106 case TemplateArgument::Type: { 2107 // We have a non-type template parameter but the template 2108 // argument is a type. 2109 2110 // C++ [temp.arg]p2: 2111 // In a template-argument, an ambiguity between a type-id and 2112 // an expression is resolved to a type-id, regardless of the 2113 // form of the corresponding template-parameter. 2114 // 2115 // We warn specifically about this case, since it can be rather 2116 // confusing for users. 2117 QualType T = Arg.getArgument().getAsType(); 2118 SourceRange SR = Arg.getSourceRange(); 2119 if (T->isFunctionType()) 2120 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; 2121 else 2122 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; 2123 Diag(Param->getLocation(), diag::note_template_param_here); 2124 return true; 2125 } 2126 2127 case TemplateArgument::Pack: 2128 llvm_unreachable("Caller must expand template argument packs"); 2129 break; 2130 } 2131 2132 return false; 2133 } 2134 2135 2136 // Check template template parameters. 2137 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param); 2138 2139 // Substitute into the template parameter list of the template 2140 // template parameter, since previously-supplied template arguments 2141 // may appear within the template template parameter. 2142 { 2143 // Set up a template instantiation context. 2144 LocalInstantiationScope Scope(*this); 2145 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 2146 TempParm, Converted.getFlatArguments(), 2147 Converted.flatSize(), 2148 SourceRange(TemplateLoc, RAngleLoc)); 2149 2150 TemplateArgumentList TemplateArgs(Context, Converted, 2151 /*TakeArgs=*/false); 2152 TempParm = cast_or_null<TemplateTemplateParmDecl>( 2153 SubstDecl(TempParm, CurContext, 2154 MultiLevelTemplateArgumentList(TemplateArgs))); 2155 if (!TempParm) 2156 return true; 2157 2158 // FIXME: TempParam is leaked. 2159 } 2160 2161 switch (Arg.getArgument().getKind()) { 2162 case TemplateArgument::Null: 2163 assert(false && "Should never see a NULL template argument here"); 2164 return true; 2165 2166 case TemplateArgument::Template: 2167 if (CheckTemplateArgument(TempParm, Arg)) 2168 return true; 2169 2170 Converted.Append(Arg.getArgument()); 2171 break; 2172 2173 case TemplateArgument::Expression: 2174 case TemplateArgument::Type: 2175 // We have a template template parameter but the template 2176 // argument does not refer to a template. 2177 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template); 2178 return true; 2179 2180 case TemplateArgument::Declaration: 2181 llvm_unreachable( 2182 "Declaration argument with template template parameter"); 2183 break; 2184 case TemplateArgument::Integral: 2185 llvm_unreachable( 2186 "Integral argument with template template parameter"); 2187 break; 2188 2189 case TemplateArgument::Pack: 2190 llvm_unreachable("Caller must expand template argument packs"); 2191 break; 2192 } 2193 2194 return false; 2195} 2196 2197/// \brief Check that the given template argument list is well-formed 2198/// for specializing the given template. 2199bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, 2200 SourceLocation TemplateLoc, 2201 const TemplateArgumentListInfo &TemplateArgs, 2202 bool PartialTemplateArgs, 2203 TemplateArgumentListBuilder &Converted) { 2204 TemplateParameterList *Params = Template->getTemplateParameters(); 2205 unsigned NumParams = Params->size(); 2206 unsigned NumArgs = TemplateArgs.size(); 2207 bool Invalid = false; 2208 2209 SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc(); 2210 2211 bool HasParameterPack = 2212 NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack(); 2213 2214 if ((NumArgs > NumParams && !HasParameterPack) || 2215 (NumArgs < Params->getMinRequiredArguments() && 2216 !PartialTemplateArgs)) { 2217 // FIXME: point at either the first arg beyond what we can handle, 2218 // or the '>', depending on whether we have too many or too few 2219 // arguments. 2220 SourceRange Range; 2221 if (NumArgs > NumParams) 2222 Range = SourceRange(TemplateArgs[NumParams].getLocation(), RAngleLoc); 2223 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 2224 << (NumArgs > NumParams) 2225 << (isa<ClassTemplateDecl>(Template)? 0 : 2226 isa<FunctionTemplateDecl>(Template)? 1 : 2227 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 2228 << Template << Range; 2229 Diag(Template->getLocation(), diag::note_template_decl_here) 2230 << Params->getSourceRange(); 2231 Invalid = true; 2232 } 2233 2234 // C++ [temp.arg]p1: 2235 // [...] The type and form of each template-argument specified in 2236 // a template-id shall match the type and form specified for the 2237 // corresponding parameter declared by the template in its 2238 // template-parameter-list. 2239 unsigned ArgIdx = 0; 2240 for (TemplateParameterList::iterator Param = Params->begin(), 2241 ParamEnd = Params->end(); 2242 Param != ParamEnd; ++Param, ++ArgIdx) { 2243 if (ArgIdx > NumArgs && PartialTemplateArgs) 2244 break; 2245 2246 // If we have a template parameter pack, check every remaining template 2247 // argument against that template parameter pack. 2248 if ((*Param)->isTemplateParameterPack()) { 2249 Converted.BeginPack(); 2250 for (; ArgIdx < NumArgs; ++ArgIdx) { 2251 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 2252 TemplateLoc, RAngleLoc, Converted)) { 2253 Invalid = true; 2254 break; 2255 } 2256 } 2257 Converted.EndPack(); 2258 continue; 2259 } 2260 2261 if (ArgIdx < NumArgs) { 2262 // Check the template argument we were given. 2263 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 2264 TemplateLoc, RAngleLoc, Converted)) 2265 return true; 2266 2267 continue; 2268 } 2269 2270 // We have a default template argument that we will use. 2271 TemplateArgumentLoc Arg; 2272 2273 // Retrieve the default template argument from the template 2274 // parameter. For each kind of template parameter, we substitute the 2275 // template arguments provided thus far and any "outer" template arguments 2276 // (when the template parameter was part of a nested template) into 2277 // the default argument. 2278 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) { 2279 if (!TTP->hasDefaultArgument()) { 2280 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2281 break; 2282 } 2283 2284 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this, 2285 Template, 2286 TemplateLoc, 2287 RAngleLoc, 2288 TTP, 2289 Converted); 2290 if (!ArgType) 2291 return true; 2292 2293 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), 2294 ArgType); 2295 } else if (NonTypeTemplateParmDecl *NTTP 2296 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 2297 if (!NTTP->hasDefaultArgument()) { 2298 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2299 break; 2300 } 2301 2302 ExprResult E = SubstDefaultTemplateArgument(*this, Template, 2303 TemplateLoc, 2304 RAngleLoc, 2305 NTTP, 2306 Converted); 2307 if (E.isInvalid()) 2308 return true; 2309 2310 Expr *Ex = E.takeAs<Expr>(); 2311 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); 2312 } else { 2313 TemplateTemplateParmDecl *TempParm 2314 = cast<TemplateTemplateParmDecl>(*Param); 2315 2316 if (!TempParm->hasDefaultArgument()) { 2317 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 2318 break; 2319 } 2320 2321 TemplateName Name = SubstDefaultTemplateArgument(*this, Template, 2322 TemplateLoc, 2323 RAngleLoc, 2324 TempParm, 2325 Converted); 2326 if (Name.isNull()) 2327 return true; 2328 2329 Arg = TemplateArgumentLoc(TemplateArgument(Name), 2330 TempParm->getDefaultArgument().getTemplateQualifierRange(), 2331 TempParm->getDefaultArgument().getTemplateNameLoc()); 2332 } 2333 2334 // Introduce an instantiation record that describes where we are using 2335 // the default template argument. 2336 InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param, 2337 Converted.getFlatArguments(), 2338 Converted.flatSize(), 2339 SourceRange(TemplateLoc, RAngleLoc)); 2340 2341 // Check the default template argument. 2342 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, 2343 RAngleLoc, Converted)) 2344 return true; 2345 } 2346 2347 return Invalid; 2348} 2349 2350/// \brief Check a template argument against its corresponding 2351/// template type parameter. 2352/// 2353/// This routine implements the semantics of C++ [temp.arg.type]. It 2354/// returns true if an error occurred, and false otherwise. 2355bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, 2356 TypeSourceInfo *ArgInfo) { 2357 assert(ArgInfo && "invalid TypeSourceInfo"); 2358 QualType Arg = ArgInfo->getType(); 2359 2360 // C++03 [temp.arg.type]p2: 2361 // A local type, a type with no linkage, an unnamed type or a type 2362 // compounded from any of these types shall not be used as a 2363 // template-argument for a template type-parameter. 2364 // C++0x allows these, and even in C++03 we allow them as an extension with 2365 // a warning. 2366 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 2367 if (!LangOpts.CPlusPlus0x) { 2368 const TagType *Tag = 0; 2369 if (const EnumType *EnumT = Arg->getAs<EnumType>()) 2370 Tag = EnumT; 2371 else if (const RecordType *RecordT = Arg->getAs<RecordType>()) 2372 Tag = RecordT; 2373 if (Tag && Tag->getDecl()->getDeclContext()->isFunctionOrMethod()) { 2374 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); 2375 Diag(SR.getBegin(), diag::ext_template_arg_local_type) 2376 << QualType(Tag, 0) << SR; 2377 } else if (Tag && !Tag->getDecl()->getDeclName() && 2378 !Tag->getDecl()->getTypedefForAnonDecl()) { 2379 Diag(SR.getBegin(), diag::ext_template_arg_unnamed_type) << SR; 2380 Diag(Tag->getDecl()->getLocation(), 2381 diag::note_template_unnamed_type_here); 2382 } 2383 } 2384 2385 if (Arg->isVariablyModifiedType()) { 2386 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg; 2387 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) { 2388 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR; 2389 } 2390 2391 return false; 2392} 2393 2394/// \brief Checks whether the given template argument is the address 2395/// of an object or function according to C++ [temp.arg.nontype]p1. 2396static bool 2397CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S, 2398 NonTypeTemplateParmDecl *Param, 2399 QualType ParamType, 2400 Expr *ArgIn, 2401 TemplateArgument &Converted) { 2402 bool Invalid = false; 2403 Expr *Arg = ArgIn; 2404 QualType ArgType = Arg->getType(); 2405 2406 // See through any implicit casts we added to fix the type. 2407 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2408 Arg = Cast->getSubExpr(); 2409 2410 // C++ [temp.arg.nontype]p1: 2411 // 2412 // A template-argument for a non-type, non-template 2413 // template-parameter shall be one of: [...] 2414 // 2415 // -- the address of an object or function with external 2416 // linkage, including function templates and function 2417 // template-ids but excluding non-static class members, 2418 // expressed as & id-expression where the & is optional if 2419 // the name refers to a function or array, or if the 2420 // corresponding template-parameter is a reference; or 2421 DeclRefExpr *DRE = 0; 2422 2423 // In C++98/03 mode, give an extension warning on any extra parentheses. 2424 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 2425 bool ExtraParens = false; 2426 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2427 if (!Invalid && !ExtraParens && !S.getLangOptions().CPlusPlus0x) { 2428 S.Diag(Arg->getSourceRange().getBegin(), 2429 diag::ext_template_arg_extra_parens) 2430 << Arg->getSourceRange(); 2431 ExtraParens = true; 2432 } 2433 2434 Arg = Parens->getSubExpr(); 2435 } 2436 2437 bool AddressTaken = false; 2438 SourceLocation AddrOpLoc; 2439 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2440 if (UnOp->getOpcode() == UO_AddrOf) { 2441 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2442 AddressTaken = true; 2443 AddrOpLoc = UnOp->getOperatorLoc(); 2444 } 2445 } else 2446 DRE = dyn_cast<DeclRefExpr>(Arg); 2447 2448 if (!DRE) { 2449 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) 2450 << Arg->getSourceRange(); 2451 S.Diag(Param->getLocation(), diag::note_template_param_here); 2452 return true; 2453 } 2454 2455 // Stop checking the precise nature of the argument if it is value dependent, 2456 // it should be checked when instantiated. 2457 if (Arg->isValueDependent()) { 2458 Converted = TemplateArgument(ArgIn->Retain()); 2459 return false; 2460 } 2461 2462 if (!isa<ValueDecl>(DRE->getDecl())) { 2463 S.Diag(Arg->getSourceRange().getBegin(), 2464 diag::err_template_arg_not_object_or_func_form) 2465 << Arg->getSourceRange(); 2466 S.Diag(Param->getLocation(), diag::note_template_param_here); 2467 return true; 2468 } 2469 2470 NamedDecl *Entity = 0; 2471 2472 // Cannot refer to non-static data members 2473 if (FieldDecl *Field = dyn_cast<FieldDecl>(DRE->getDecl())) { 2474 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_field) 2475 << Field << Arg->getSourceRange(); 2476 S.Diag(Param->getLocation(), diag::note_template_param_here); 2477 return true; 2478 } 2479 2480 // Cannot refer to non-static member functions 2481 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(DRE->getDecl())) 2482 if (!Method->isStatic()) { 2483 S.Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_method) 2484 << Method << Arg->getSourceRange(); 2485 S.Diag(Param->getLocation(), diag::note_template_param_here); 2486 return true; 2487 } 2488 2489 // Functions must have external linkage. 2490 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(DRE->getDecl())) { 2491 if (!isExternalLinkage(Func->getLinkage())) { 2492 S.Diag(Arg->getSourceRange().getBegin(), 2493 diag::err_template_arg_function_not_extern) 2494 << Func << Arg->getSourceRange(); 2495 S.Diag(Func->getLocation(), diag::note_template_arg_internal_object) 2496 << true; 2497 return true; 2498 } 2499 2500 // Okay: we've named a function with external linkage. 2501 Entity = Func; 2502 2503 // If the template parameter has pointer type, the function decays. 2504 if (ParamType->isPointerType() && !AddressTaken) 2505 ArgType = S.Context.getPointerType(Func->getType()); 2506 else if (AddressTaken && ParamType->isReferenceType()) { 2507 // If we originally had an address-of operator, but the 2508 // parameter has reference type, complain and (if things look 2509 // like they will work) drop the address-of operator. 2510 if (!S.Context.hasSameUnqualifiedType(Func->getType(), 2511 ParamType.getNonReferenceType())) { 2512 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2513 << ParamType; 2514 S.Diag(Param->getLocation(), diag::note_template_param_here); 2515 return true; 2516 } 2517 2518 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2519 << ParamType 2520 << FixItHint::CreateRemoval(AddrOpLoc); 2521 S.Diag(Param->getLocation(), diag::note_template_param_here); 2522 2523 ArgType = Func->getType(); 2524 } 2525 } else if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 2526 if (!isExternalLinkage(Var->getLinkage())) { 2527 S.Diag(Arg->getSourceRange().getBegin(), 2528 diag::err_template_arg_object_not_extern) 2529 << Var << Arg->getSourceRange(); 2530 S.Diag(Var->getLocation(), diag::note_template_arg_internal_object) 2531 << true; 2532 return true; 2533 } 2534 2535 // A value of reference type is not an object. 2536 if (Var->getType()->isReferenceType()) { 2537 S.Diag(Arg->getSourceRange().getBegin(), 2538 diag::err_template_arg_reference_var) 2539 << Var->getType() << Arg->getSourceRange(); 2540 S.Diag(Param->getLocation(), diag::note_template_param_here); 2541 return true; 2542 } 2543 2544 // Okay: we've named an object with external linkage 2545 Entity = Var; 2546 2547 // If the template parameter has pointer type, we must have taken 2548 // the address of this object. 2549 if (ParamType->isReferenceType()) { 2550 if (AddressTaken) { 2551 // If we originally had an address-of operator, but the 2552 // parameter has reference type, complain and (if things look 2553 // like they will work) drop the address-of operator. 2554 if (!S.Context.hasSameUnqualifiedType(Var->getType(), 2555 ParamType.getNonReferenceType())) { 2556 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2557 << ParamType; 2558 S.Diag(Param->getLocation(), diag::note_template_param_here); 2559 return true; 2560 } 2561 2562 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) 2563 << ParamType 2564 << FixItHint::CreateRemoval(AddrOpLoc); 2565 S.Diag(Param->getLocation(), diag::note_template_param_here); 2566 2567 ArgType = Var->getType(); 2568 } 2569 } else if (!AddressTaken && ParamType->isPointerType()) { 2570 if (Var->getType()->isArrayType()) { 2571 // Array-to-pointer decay. 2572 ArgType = S.Context.getArrayDecayedType(Var->getType()); 2573 } else { 2574 // If the template parameter has pointer type but the address of 2575 // this object was not taken, complain and (possibly) recover by 2576 // taking the address of the entity. 2577 ArgType = S.Context.getPointerType(Var->getType()); 2578 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) { 2579 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 2580 << ParamType; 2581 S.Diag(Param->getLocation(), diag::note_template_param_here); 2582 return true; 2583 } 2584 2585 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) 2586 << ParamType 2587 << FixItHint::CreateInsertion(Arg->getLocStart(), "&"); 2588 2589 S.Diag(Param->getLocation(), diag::note_template_param_here); 2590 } 2591 } 2592 } else { 2593 // We found something else, but we don't know specifically what it is. 2594 S.Diag(Arg->getSourceRange().getBegin(), 2595 diag::err_template_arg_not_object_or_func) 2596 << Arg->getSourceRange(); 2597 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); 2598 return true; 2599 } 2600 2601 if (ParamType->isPointerType() && 2602 !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() && 2603 S.IsQualificationConversion(ArgType, ParamType)) { 2604 // For pointer-to-object types, qualification conversions are 2605 // permitted. 2606 } else { 2607 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) { 2608 if (!ParamRef->getPointeeType()->isFunctionType()) { 2609 // C++ [temp.arg.nontype]p5b3: 2610 // For a non-type template-parameter of type reference to 2611 // object, no conversions apply. The type referred to by the 2612 // reference may be more cv-qualified than the (otherwise 2613 // identical) type of the template- argument. The 2614 // template-parameter is bound directly to the 2615 // template-argument, which shall be an lvalue. 2616 2617 // FIXME: Other qualifiers? 2618 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers(); 2619 unsigned ArgQuals = ArgType.getCVRQualifiers(); 2620 2621 if ((ParamQuals | ArgQuals) != ParamQuals) { 2622 S.Diag(Arg->getSourceRange().getBegin(), 2623 diag::err_template_arg_ref_bind_ignores_quals) 2624 << ParamType << Arg->getType() 2625 << Arg->getSourceRange(); 2626 S.Diag(Param->getLocation(), diag::note_template_param_here); 2627 return true; 2628 } 2629 } 2630 } 2631 2632 // At this point, the template argument refers to an object or 2633 // function with external linkage. We now need to check whether the 2634 // argument and parameter types are compatible. 2635 if (!S.Context.hasSameUnqualifiedType(ArgType, 2636 ParamType.getNonReferenceType())) { 2637 // We can't perform this conversion or binding. 2638 if (ParamType->isReferenceType()) 2639 S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind) 2640 << ParamType << Arg->getType() << Arg->getSourceRange(); 2641 else 2642 S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) 2643 << Arg->getType() << ParamType << Arg->getSourceRange(); 2644 S.Diag(Param->getLocation(), diag::note_template_param_here); 2645 return true; 2646 } 2647 } 2648 2649 // Create the template argument. 2650 Converted = TemplateArgument(Entity->getCanonicalDecl()); 2651 S.MarkDeclarationReferenced(Arg->getLocStart(), Entity); 2652 return false; 2653} 2654 2655/// \brief Checks whether the given template argument is a pointer to 2656/// member constant according to C++ [temp.arg.nontype]p1. 2657bool Sema::CheckTemplateArgumentPointerToMember(Expr *Arg, 2658 TemplateArgument &Converted) { 2659 bool Invalid = false; 2660 2661 // See through any implicit casts we added to fix the type. 2662 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2663 Arg = Cast->getSubExpr(); 2664 2665 // C++ [temp.arg.nontype]p1: 2666 // 2667 // A template-argument for a non-type, non-template 2668 // template-parameter shall be one of: [...] 2669 // 2670 // -- a pointer to member expressed as described in 5.3.1. 2671 DeclRefExpr *DRE = 0; 2672 2673 // In C++98/03 mode, give an extension warning on any extra parentheses. 2674 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 2675 bool ExtraParens = false; 2676 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2677 if (!Invalid && !ExtraParens && !getLangOptions().CPlusPlus0x) { 2678 Diag(Arg->getSourceRange().getBegin(), 2679 diag::ext_template_arg_extra_parens) 2680 << Arg->getSourceRange(); 2681 ExtraParens = true; 2682 } 2683 2684 Arg = Parens->getSubExpr(); 2685 } 2686 2687 // A pointer-to-member constant written &Class::member. 2688 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2689 if (UnOp->getOpcode() == UO_AddrOf) { 2690 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2691 if (DRE && !DRE->getQualifier()) 2692 DRE = 0; 2693 } 2694 } 2695 // A constant of pointer-to-member type. 2696 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) { 2697 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) { 2698 if (VD->getType()->isMemberPointerType()) { 2699 if (isa<NonTypeTemplateParmDecl>(VD) || 2700 (isa<VarDecl>(VD) && 2701 Context.getCanonicalType(VD->getType()).isConstQualified())) { 2702 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2703 Converted = TemplateArgument(Arg->Retain()); 2704 else 2705 Converted = TemplateArgument(VD->getCanonicalDecl()); 2706 return Invalid; 2707 } 2708 } 2709 } 2710 2711 DRE = 0; 2712 } 2713 2714 if (!DRE) 2715 return Diag(Arg->getSourceRange().getBegin(), 2716 diag::err_template_arg_not_pointer_to_member_form) 2717 << Arg->getSourceRange(); 2718 2719 if (isa<FieldDecl>(DRE->getDecl()) || isa<CXXMethodDecl>(DRE->getDecl())) { 2720 assert((isa<FieldDecl>(DRE->getDecl()) || 2721 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && 2722 "Only non-static member pointers can make it here"); 2723 2724 // Okay: this is the address of a non-static member, and therefore 2725 // a member pointer constant. 2726 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2727 Converted = TemplateArgument(Arg->Retain()); 2728 else 2729 Converted = TemplateArgument(DRE->getDecl()->getCanonicalDecl()); 2730 return Invalid; 2731 } 2732 2733 // We found something else, but we don't know specifically what it is. 2734 Diag(Arg->getSourceRange().getBegin(), 2735 diag::err_template_arg_not_pointer_to_member_form) 2736 << Arg->getSourceRange(); 2737 Diag(DRE->getDecl()->getLocation(), 2738 diag::note_template_arg_refers_here); 2739 return true; 2740} 2741 2742/// \brief Check a template argument against its corresponding 2743/// non-type template parameter. 2744/// 2745/// This routine implements the semantics of C++ [temp.arg.nontype]. 2746/// It returns true if an error occurred, and false otherwise. \p 2747/// InstantiatedParamType is the type of the non-type template 2748/// parameter after it has been instantiated. 2749/// 2750/// If no error was detected, Converted receives the converted template argument. 2751bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, 2752 QualType InstantiatedParamType, Expr *&Arg, 2753 TemplateArgument &Converted, 2754 CheckTemplateArgumentKind CTAK) { 2755 SourceLocation StartLoc = Arg->getSourceRange().getBegin(); 2756 2757 // If either the parameter has a dependent type or the argument is 2758 // type-dependent, there's nothing we can check now. 2759 if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) { 2760 // FIXME: Produce a cloned, canonical expression? 2761 Converted = TemplateArgument(Arg); 2762 return false; 2763 } 2764 2765 // C++ [temp.arg.nontype]p5: 2766 // The following conversions are performed on each expression used 2767 // as a non-type template-argument. If a non-type 2768 // template-argument cannot be converted to the type of the 2769 // corresponding template-parameter then the program is 2770 // ill-formed. 2771 // 2772 // -- for a non-type template-parameter of integral or 2773 // enumeration type, integral promotions (4.5) and integral 2774 // conversions (4.7) are applied. 2775 QualType ParamType = InstantiatedParamType; 2776 QualType ArgType = Arg->getType(); 2777 if (ParamType->isIntegralOrEnumerationType()) { 2778 // C++ [temp.arg.nontype]p1: 2779 // A template-argument for a non-type, non-template 2780 // template-parameter shall be one of: 2781 // 2782 // -- an integral constant-expression of integral or enumeration 2783 // type; or 2784 // -- the name of a non-type template-parameter; or 2785 SourceLocation NonConstantLoc; 2786 llvm::APSInt Value; 2787 if (!ArgType->isIntegralOrEnumerationType()) { 2788 Diag(Arg->getSourceRange().getBegin(), 2789 diag::err_template_arg_not_integral_or_enumeral) 2790 << ArgType << Arg->getSourceRange(); 2791 Diag(Param->getLocation(), diag::note_template_param_here); 2792 return true; 2793 } else if (!Arg->isValueDependent() && 2794 !Arg->isIntegerConstantExpr(Value, Context, &NonConstantLoc)) { 2795 Diag(NonConstantLoc, diag::err_template_arg_not_ice) 2796 << ArgType << Arg->getSourceRange(); 2797 return true; 2798 } 2799 2800 // From here on out, all we care about are the unqualified forms 2801 // of the parameter and argument types. 2802 ParamType = ParamType.getUnqualifiedType(); 2803 ArgType = ArgType.getUnqualifiedType(); 2804 2805 // Try to convert the argument to the parameter's type. 2806 if (Context.hasSameType(ParamType, ArgType)) { 2807 // Okay: no conversion necessary 2808 } else if (CTAK == CTAK_Deduced) { 2809 // C++ [temp.deduct.type]p17: 2810 // If, in the declaration of a function template with a non-type 2811 // template-parameter, the non-type template- parameter is used 2812 // in an expression in the function parameter-list and, if the 2813 // corresponding template-argument is deduced, the 2814 // template-argument type shall match the type of the 2815 // template-parameter exactly, except that a template-argument 2816 // deduced from an array bound may be of any integral type. 2817 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch) 2818 << ArgType << ParamType; 2819 Diag(Param->getLocation(), diag::note_template_param_here); 2820 return true; 2821 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || 2822 !ParamType->isEnumeralType()) { 2823 // This is an integral promotion or conversion. 2824 ImpCastExprToType(Arg, ParamType, CK_IntegralCast); 2825 } else { 2826 // We can't perform this conversion. 2827 Diag(Arg->getSourceRange().getBegin(), 2828 diag::err_template_arg_not_convertible) 2829 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2830 Diag(Param->getLocation(), diag::note_template_param_here); 2831 return true; 2832 } 2833 2834 QualType IntegerType = Context.getCanonicalType(ParamType); 2835 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 2836 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); 2837 2838 if (!Arg->isValueDependent()) { 2839 llvm::APSInt OldValue = Value; 2840 2841 // Coerce the template argument's value to the value it will have 2842 // based on the template parameter's type. 2843 unsigned AllowedBits = Context.getTypeSize(IntegerType); 2844 if (Value.getBitWidth() != AllowedBits) 2845 Value.extOrTrunc(AllowedBits); 2846 Value.setIsSigned(IntegerType->isSignedIntegerType()); 2847 2848 // Complain if an unsigned parameter received a negative value. 2849 if (IntegerType->isUnsignedIntegerType() 2850 && (OldValue.isSigned() && OldValue.isNegative())) { 2851 Diag(Arg->getSourceRange().getBegin(), diag::warn_template_arg_negative) 2852 << OldValue.toString(10) << Value.toString(10) << Param->getType() 2853 << Arg->getSourceRange(); 2854 Diag(Param->getLocation(), diag::note_template_param_here); 2855 } 2856 2857 // Complain if we overflowed the template parameter's type. 2858 unsigned RequiredBits; 2859 if (IntegerType->isUnsignedIntegerType()) 2860 RequiredBits = OldValue.getActiveBits(); 2861 else if (OldValue.isUnsigned()) 2862 RequiredBits = OldValue.getActiveBits() + 1; 2863 else 2864 RequiredBits = OldValue.getMinSignedBits(); 2865 if (RequiredBits > AllowedBits) { 2866 Diag(Arg->getSourceRange().getBegin(), 2867 diag::warn_template_arg_too_large) 2868 << OldValue.toString(10) << Value.toString(10) << Param->getType() 2869 << Arg->getSourceRange(); 2870 Diag(Param->getLocation(), diag::note_template_param_here); 2871 } 2872 } 2873 2874 // Add the value of this argument to the list of converted 2875 // arguments. We use the bitwidth and signedness of the template 2876 // parameter. 2877 if (Arg->isValueDependent()) { 2878 // The argument is value-dependent. Create a new 2879 // TemplateArgument with the converted expression. 2880 Converted = TemplateArgument(Arg); 2881 return false; 2882 } 2883 2884 Converted = TemplateArgument(Value, 2885 ParamType->isEnumeralType() ? ParamType 2886 : IntegerType); 2887 return false; 2888 } 2889 2890 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction 2891 2892 // C++0x [temp.arg.nontype]p5 bullets 2, 4 and 6 permit conversion 2893 // from a template argument of type std::nullptr_t to a non-type 2894 // template parameter of type pointer to object, pointer to 2895 // function, or pointer-to-member, respectively. 2896 if (ArgType->isNullPtrType() && 2897 (ParamType->isPointerType() || ParamType->isMemberPointerType())) { 2898 Converted = TemplateArgument((NamedDecl *)0); 2899 return false; 2900 } 2901 2902 // Handle pointer-to-function, reference-to-function, and 2903 // pointer-to-member-function all in (roughly) the same way. 2904 if (// -- For a non-type template-parameter of type pointer to 2905 // function, only the function-to-pointer conversion (4.3) is 2906 // applied. If the template-argument represents a set of 2907 // overloaded functions (or a pointer to such), the matching 2908 // function is selected from the set (13.4). 2909 (ParamType->isPointerType() && 2910 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) || 2911 // -- For a non-type template-parameter of type reference to 2912 // function, no conversions apply. If the template-argument 2913 // represents a set of overloaded functions, the matching 2914 // function is selected from the set (13.4). 2915 (ParamType->isReferenceType() && 2916 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) || 2917 // -- For a non-type template-parameter of type pointer to 2918 // member function, no conversions apply. If the 2919 // template-argument represents a set of overloaded member 2920 // functions, the matching member function is selected from 2921 // the set (13.4). 2922 (ParamType->isMemberPointerType() && 2923 ParamType->getAs<MemberPointerType>()->getPointeeType() 2924 ->isFunctionType())) { 2925 2926 if (Arg->getType() == Context.OverloadTy) { 2927 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 2928 true, 2929 FoundResult)) { 2930 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 2931 return true; 2932 2933 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 2934 ArgType = Arg->getType(); 2935 } else 2936 return true; 2937 } 2938 2939 if (!ParamType->isMemberPointerType()) 2940 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2941 ParamType, 2942 Arg, Converted); 2943 2944 if (IsQualificationConversion(ArgType, ParamType.getNonReferenceType())) { 2945 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 2946 } else if (!Context.hasSameUnqualifiedType(ArgType, 2947 ParamType.getNonReferenceType())) { 2948 // We can't perform this conversion. 2949 Diag(Arg->getSourceRange().getBegin(), 2950 diag::err_template_arg_not_convertible) 2951 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2952 Diag(Param->getLocation(), diag::note_template_param_here); 2953 return true; 2954 } 2955 2956 return CheckTemplateArgumentPointerToMember(Arg, Converted); 2957 } 2958 2959 if (ParamType->isPointerType()) { 2960 // -- for a non-type template-parameter of type pointer to 2961 // object, qualification conversions (4.4) and the 2962 // array-to-pointer conversion (4.2) are applied. 2963 // C++0x also allows a value of std::nullptr_t. 2964 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() && 2965 "Only object pointers allowed here"); 2966 2967 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2968 ParamType, 2969 Arg, Converted); 2970 } 2971 2972 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { 2973 // -- For a non-type template-parameter of type reference to 2974 // object, no conversions apply. The type referred to by the 2975 // reference may be more cv-qualified than the (otherwise 2976 // identical) type of the template-argument. The 2977 // template-parameter is bound directly to the 2978 // template-argument, which must be an lvalue. 2979 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() && 2980 "Only object references allowed here"); 2981 2982 if (Arg->getType() == Context.OverloadTy) { 2983 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 2984 ParamRefType->getPointeeType(), 2985 true, 2986 FoundResult)) { 2987 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 2988 return true; 2989 2990 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); 2991 ArgType = Arg->getType(); 2992 } else 2993 return true; 2994 } 2995 2996 return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 2997 ParamType, 2998 Arg, Converted); 2999 } 3000 3001 // -- For a non-type template-parameter of type pointer to data 3002 // member, qualification conversions (4.4) are applied. 3003 assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); 3004 3005 if (Context.hasSameUnqualifiedType(ParamType, ArgType)) { 3006 // Types match exactly: nothing more to do here. 3007 } else if (IsQualificationConversion(ArgType, ParamType)) { 3008 ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg)); 3009 } else { 3010 // We can't perform this conversion. 3011 Diag(Arg->getSourceRange().getBegin(), 3012 diag::err_template_arg_not_convertible) 3013 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 3014 Diag(Param->getLocation(), diag::note_template_param_here); 3015 return true; 3016 } 3017 3018 return CheckTemplateArgumentPointerToMember(Arg, Converted); 3019} 3020 3021/// \brief Check a template argument against its corresponding 3022/// template template parameter. 3023/// 3024/// This routine implements the semantics of C++ [temp.arg.template]. 3025/// It returns true if an error occurred, and false otherwise. 3026bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, 3027 const TemplateArgumentLoc &Arg) { 3028 TemplateName Name = Arg.getArgument().getAsTemplate(); 3029 TemplateDecl *Template = Name.getAsTemplateDecl(); 3030 if (!Template) { 3031 // Any dependent template name is fine. 3032 assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); 3033 return false; 3034 } 3035 3036 // C++ [temp.arg.template]p1: 3037 // A template-argument for a template template-parameter shall be 3038 // the name of a class template, expressed as id-expression. Only 3039 // primary class templates are considered when matching the 3040 // template template argument with the corresponding parameter; 3041 // partial specializations are not considered even if their 3042 // parameter lists match that of the template template parameter. 3043 // 3044 // Note that we also allow template template parameters here, which 3045 // will happen when we are dealing with, e.g., class template 3046 // partial specializations. 3047 if (!isa<ClassTemplateDecl>(Template) && 3048 !isa<TemplateTemplateParmDecl>(Template)) { 3049 assert(isa<FunctionTemplateDecl>(Template) && 3050 "Only function templates are possible here"); 3051 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); 3052 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) 3053 << Template; 3054 } 3055 3056 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), 3057 Param->getTemplateParameters(), 3058 true, 3059 TPL_TemplateTemplateArgumentMatch, 3060 Arg.getLocation()); 3061} 3062 3063/// \brief Given a non-type template argument that refers to a 3064/// declaration and the type of its corresponding non-type template 3065/// parameter, produce an expression that properly refers to that 3066/// declaration. 3067ExprResult 3068Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg, 3069 QualType ParamType, 3070 SourceLocation Loc) { 3071 assert(Arg.getKind() == TemplateArgument::Declaration && 3072 "Only declaration template arguments permitted here"); 3073 ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl()); 3074 3075 if (VD->getDeclContext()->isRecord() && 3076 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD))) { 3077 // If the value is a class member, we might have a pointer-to-member. 3078 // Determine whether the non-type template template parameter is of 3079 // pointer-to-member type. If so, we need to build an appropriate 3080 // expression for a pointer-to-member, since a "normal" DeclRefExpr 3081 // would refer to the member itself. 3082 if (ParamType->isMemberPointerType()) { 3083 QualType ClassType 3084 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext())); 3085 NestedNameSpecifier *Qualifier 3086 = NestedNameSpecifier::Create(Context, 0, false, 3087 ClassType.getTypePtr()); 3088 CXXScopeSpec SS; 3089 SS.setScopeRep(Qualifier); 3090 ExprResult RefExpr = BuildDeclRefExpr(VD, 3091 VD->getType().getNonReferenceType(), 3092 Loc, 3093 &SS); 3094 if (RefExpr.isInvalid()) 3095 return ExprError(); 3096 3097 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3098 3099 // We might need to perform a trailing qualification conversion, since 3100 // the element type on the parameter could be more qualified than the 3101 // element type in the expression we constructed. 3102 if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(), 3103 ParamType.getUnqualifiedType())) { 3104 Expr *RefE = RefExpr.takeAs<Expr>(); 3105 ImpCastExprToType(RefE, ParamType.getUnqualifiedType(), CK_NoOp); 3106 RefExpr = Owned(RefE); 3107 } 3108 3109 assert(!RefExpr.isInvalid() && 3110 Context.hasSameType(((Expr*) RefExpr.get())->getType(), 3111 ParamType.getUnqualifiedType())); 3112 return move(RefExpr); 3113 } 3114 } 3115 3116 QualType T = VD->getType().getNonReferenceType(); 3117 if (ParamType->isPointerType()) { 3118 // When the non-type template parameter is a pointer, take the 3119 // address of the declaration. 3120 ExprResult RefExpr = BuildDeclRefExpr(VD, T, Loc); 3121 if (RefExpr.isInvalid()) 3122 return ExprError(); 3123 3124 if (T->isFunctionType() || T->isArrayType()) { 3125 // Decay functions and arrays. 3126 Expr *RefE = (Expr *)RefExpr.get(); 3127 DefaultFunctionArrayConversion(RefE); 3128 if (RefE != RefExpr.get()) { 3129 RefExpr.release(); 3130 RefExpr = Owned(RefE); 3131 } 3132 3133 return move(RefExpr); 3134 } 3135 3136 // Take the address of everything else 3137 return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); 3138 } 3139 3140 // If the non-type template parameter has reference type, qualify the 3141 // resulting declaration reference with the extra qualifiers on the 3142 // type that the reference refers to. 3143 if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) 3144 T = Context.getQualifiedType(T, TargetRef->getPointeeType().getQualifiers()); 3145 3146 return BuildDeclRefExpr(VD, T, Loc); 3147} 3148 3149/// \brief Construct a new expression that refers to the given 3150/// integral template argument with the given source-location 3151/// information. 3152/// 3153/// This routine takes care of the mapping from an integral template 3154/// argument (which may have any integral type) to the appropriate 3155/// literal value. 3156ExprResult 3157Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg, 3158 SourceLocation Loc) { 3159 assert(Arg.getKind() == TemplateArgument::Integral && 3160 "Operation is only value for integral template arguments"); 3161 QualType T = Arg.getIntegralType(); 3162 if (T->isCharType() || T->isWideCharType()) 3163 return Owned(new (Context) CharacterLiteral( 3164 Arg.getAsIntegral()->getZExtValue(), 3165 T->isWideCharType(), 3166 T, 3167 Loc)); 3168 if (T->isBooleanType()) 3169 return Owned(new (Context) CXXBoolLiteralExpr( 3170 Arg.getAsIntegral()->getBoolValue(), 3171 T, 3172 Loc)); 3173 3174 return Owned(IntegerLiteral::Create(Context, *Arg.getAsIntegral(), T, Loc)); 3175} 3176 3177 3178/// \brief Determine whether the given template parameter lists are 3179/// equivalent. 3180/// 3181/// \param New The new template parameter list, typically written in the 3182/// source code as part of a new template declaration. 3183/// 3184/// \param Old The old template parameter list, typically found via 3185/// name lookup of the template declared with this template parameter 3186/// list. 3187/// 3188/// \param Complain If true, this routine will produce a diagnostic if 3189/// the template parameter lists are not equivalent. 3190/// 3191/// \param Kind describes how we are to match the template parameter lists. 3192/// 3193/// \param TemplateArgLoc If this source location is valid, then we 3194/// are actually checking the template parameter list of a template 3195/// argument (New) against the template parameter list of its 3196/// corresponding template template parameter (Old). We produce 3197/// slightly different diagnostics in this scenario. 3198/// 3199/// \returns True if the template parameter lists are equal, false 3200/// otherwise. 3201bool 3202Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, 3203 TemplateParameterList *Old, 3204 bool Complain, 3205 TemplateParameterListEqualKind Kind, 3206 SourceLocation TemplateArgLoc) { 3207 if (Old->size() != New->size()) { 3208 if (Complain) { 3209 unsigned NextDiag = diag::err_template_param_list_different_arity; 3210 if (TemplateArgLoc.isValid()) { 3211 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3212 NextDiag = diag::note_template_param_list_different_arity; 3213 } 3214 Diag(New->getTemplateLoc(), NextDiag) 3215 << (New->size() > Old->size()) 3216 << (Kind != TPL_TemplateMatch) 3217 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); 3218 Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) 3219 << (Kind != TPL_TemplateMatch) 3220 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); 3221 } 3222 3223 return false; 3224 } 3225 3226 for (TemplateParameterList::iterator OldParm = Old->begin(), 3227 OldParmEnd = Old->end(), NewParm = New->begin(); 3228 OldParm != OldParmEnd; ++OldParm, ++NewParm) { 3229 if ((*OldParm)->getKind() != (*NewParm)->getKind()) { 3230 if (Complain) { 3231 unsigned NextDiag = diag::err_template_param_different_kind; 3232 if (TemplateArgLoc.isValid()) { 3233 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 3234 NextDiag = diag::note_template_param_different_kind; 3235 } 3236 Diag((*NewParm)->getLocation(), NextDiag) 3237 << (Kind != TPL_TemplateMatch); 3238 Diag((*OldParm)->getLocation(), diag::note_template_prev_declaration) 3239 << (Kind != TPL_TemplateMatch); 3240 } 3241 return false; 3242 } 3243 3244 if (TemplateTypeParmDecl *OldTTP 3245 = dyn_cast<TemplateTypeParmDecl>(*OldParm)) { 3246 // Template type parameters are equivalent if either both are template 3247 // type parameter packs or neither are (since we know we're at the same 3248 // index). 3249 TemplateTypeParmDecl *NewTTP = cast<TemplateTypeParmDecl>(*NewParm); 3250 if (OldTTP->isParameterPack() != NewTTP->isParameterPack()) { 3251 // FIXME: Implement the rules in C++0x [temp.arg.template]p5 that 3252 // allow one to match a template parameter pack in the template 3253 // parameter list of a template template parameter to one or more 3254 // template parameters in the template parameter list of the 3255 // corresponding template template argument. 3256 if (Complain) { 3257 unsigned NextDiag = diag::err_template_parameter_pack_non_pack; 3258 if (TemplateArgLoc.isValid()) { 3259 Diag(TemplateArgLoc, 3260 diag::err_template_arg_template_params_mismatch); 3261 NextDiag = diag::note_template_parameter_pack_non_pack; 3262 } 3263 Diag(NewTTP->getLocation(), NextDiag) 3264 << 0 << NewTTP->isParameterPack(); 3265 Diag(OldTTP->getLocation(), diag::note_template_parameter_pack_here) 3266 << 0 << OldTTP->isParameterPack(); 3267 } 3268 return false; 3269 } 3270 } else if (NonTypeTemplateParmDecl *OldNTTP 3271 = dyn_cast<NonTypeTemplateParmDecl>(*OldParm)) { 3272 // The types of non-type template parameters must agree. 3273 NonTypeTemplateParmDecl *NewNTTP 3274 = cast<NonTypeTemplateParmDecl>(*NewParm); 3275 3276 // If we are matching a template template argument to a template 3277 // template parameter and one of the non-type template parameter types 3278 // is dependent, then we must wait until template instantiation time 3279 // to actually compare the arguments. 3280 if (Kind == TPL_TemplateTemplateArgumentMatch && 3281 (OldNTTP->getType()->isDependentType() || 3282 NewNTTP->getType()->isDependentType())) 3283 continue; 3284 3285 if (Context.getCanonicalType(OldNTTP->getType()) != 3286 Context.getCanonicalType(NewNTTP->getType())) { 3287 if (Complain) { 3288 unsigned NextDiag = diag::err_template_nontype_parm_different_type; 3289 if (TemplateArgLoc.isValid()) { 3290 Diag(TemplateArgLoc, 3291 diag::err_template_arg_template_params_mismatch); 3292 NextDiag = diag::note_template_nontype_parm_different_type; 3293 } 3294 Diag(NewNTTP->getLocation(), NextDiag) 3295 << NewNTTP->getType() 3296 << (Kind != TPL_TemplateMatch); 3297 Diag(OldNTTP->getLocation(), 3298 diag::note_template_nontype_parm_prev_declaration) 3299 << OldNTTP->getType(); 3300 } 3301 return false; 3302 } 3303 } else { 3304 // The template parameter lists of template template 3305 // parameters must agree. 3306 assert(isa<TemplateTemplateParmDecl>(*OldParm) && 3307 "Only template template parameters handled here"); 3308 TemplateTemplateParmDecl *OldTTP 3309 = cast<TemplateTemplateParmDecl>(*OldParm); 3310 TemplateTemplateParmDecl *NewTTP 3311 = cast<TemplateTemplateParmDecl>(*NewParm); 3312 if (!TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), 3313 OldTTP->getTemplateParameters(), 3314 Complain, 3315 (Kind == TPL_TemplateMatch? TPL_TemplateTemplateParmMatch : Kind), 3316 TemplateArgLoc)) 3317 return false; 3318 } 3319 } 3320 3321 return true; 3322} 3323 3324/// \brief Check whether a template can be declared within this scope. 3325/// 3326/// If the template declaration is valid in this scope, returns 3327/// false. Otherwise, issues a diagnostic and returns true. 3328bool 3329Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { 3330 // Find the nearest enclosing declaration scope. 3331 while ((S->getFlags() & Scope::DeclScope) == 0 || 3332 (S->getFlags() & Scope::TemplateParamScope) != 0) 3333 S = S->getParent(); 3334 3335 // C++ [temp]p2: 3336 // A template-declaration can appear only as a namespace scope or 3337 // class scope declaration. 3338 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 3339 if (Ctx && isa<LinkageSpecDecl>(Ctx) && 3340 cast<LinkageSpecDecl>(Ctx)->getLanguage() != LinkageSpecDecl::lang_cxx) 3341 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) 3342 << TemplateParams->getSourceRange(); 3343 3344 while (Ctx && isa<LinkageSpecDecl>(Ctx)) 3345 Ctx = Ctx->getParent(); 3346 3347 if (Ctx && (Ctx->isFileContext() || Ctx->isRecord())) 3348 return false; 3349 3350 return Diag(TemplateParams->getTemplateLoc(), 3351 diag::err_template_outside_namespace_or_class_scope) 3352 << TemplateParams->getSourceRange(); 3353} 3354 3355/// \brief Determine what kind of template specialization the given declaration 3356/// is. 3357static TemplateSpecializationKind getTemplateSpecializationKind(NamedDecl *D) { 3358 if (!D) 3359 return TSK_Undeclared; 3360 3361 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) 3362 return Record->getTemplateSpecializationKind(); 3363 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) 3364 return Function->getTemplateSpecializationKind(); 3365 if (VarDecl *Var = dyn_cast<VarDecl>(D)) 3366 return Var->getTemplateSpecializationKind(); 3367 3368 return TSK_Undeclared; 3369} 3370 3371/// \brief Check whether a specialization is well-formed in the current 3372/// context. 3373/// 3374/// This routine determines whether a template specialization can be declared 3375/// in the current context (C++ [temp.expl.spec]p2). 3376/// 3377/// \param S the semantic analysis object for which this check is being 3378/// performed. 3379/// 3380/// \param Specialized the entity being specialized or instantiated, which 3381/// may be a kind of template (class template, function template, etc.) or 3382/// a member of a class template (member function, static data member, 3383/// member class). 3384/// 3385/// \param PrevDecl the previous declaration of this entity, if any. 3386/// 3387/// \param Loc the location of the explicit specialization or instantiation of 3388/// this entity. 3389/// 3390/// \param IsPartialSpecialization whether this is a partial specialization of 3391/// a class template. 3392/// 3393/// \returns true if there was an error that we cannot recover from, false 3394/// otherwise. 3395static bool CheckTemplateSpecializationScope(Sema &S, 3396 NamedDecl *Specialized, 3397 NamedDecl *PrevDecl, 3398 SourceLocation Loc, 3399 bool IsPartialSpecialization) { 3400 // Keep these "kind" numbers in sync with the %select statements in the 3401 // various diagnostics emitted by this routine. 3402 int EntityKind = 0; 3403 bool isTemplateSpecialization = false; 3404 if (isa<ClassTemplateDecl>(Specialized)) { 3405 EntityKind = IsPartialSpecialization? 1 : 0; 3406 isTemplateSpecialization = true; 3407 } else if (isa<FunctionTemplateDecl>(Specialized)) { 3408 EntityKind = 2; 3409 isTemplateSpecialization = true; 3410 } else if (isa<CXXMethodDecl>(Specialized)) 3411 EntityKind = 3; 3412 else if (isa<VarDecl>(Specialized)) 3413 EntityKind = 4; 3414 else if (isa<RecordDecl>(Specialized)) 3415 EntityKind = 5; 3416 else { 3417 S.Diag(Loc, diag::err_template_spec_unknown_kind); 3418 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3419 return true; 3420 } 3421 3422 // C++ [temp.expl.spec]p2: 3423 // An explicit specialization shall be declared in the namespace 3424 // of which the template is a member, or, for member templates, in 3425 // the namespace of which the enclosing class or enclosing class 3426 // template is a member. An explicit specialization of a member 3427 // function, member class or static data member of a class 3428 // template shall be declared in the namespace of which the class 3429 // template is a member. Such a declaration may also be a 3430 // definition. If the declaration is not a definition, the 3431 // specialization may be defined later in the name- space in which 3432 // the explicit specialization was declared, or in a namespace 3433 // that encloses the one in which the explicit specialization was 3434 // declared. 3435 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) { 3436 S.Diag(Loc, diag::err_template_spec_decl_function_scope) 3437 << Specialized; 3438 return true; 3439 } 3440 3441 if (S.CurContext->isRecord() && !IsPartialSpecialization) { 3442 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 3443 << Specialized; 3444 return true; 3445 } 3446 3447 // C++ [temp.class.spec]p6: 3448 // A class template partial specialization may be declared or redeclared 3449 // in any namespace scope in which its definition may be defined (14.5.1 3450 // and 14.5.2). 3451 bool ComplainedAboutScope = false; 3452 DeclContext *SpecializedContext 3453 = Specialized->getDeclContext()->getEnclosingNamespaceContext(); 3454 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); 3455 if ((!PrevDecl || 3456 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || 3457 getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)){ 3458 // C++ [temp.exp.spec]p2: 3459 // An explicit specialization shall be declared in the namespace of which 3460 // the template is a member, or, for member templates, in the namespace 3461 // of which the enclosing class or enclosing class template is a member. 3462 // An explicit specialization of a member function, member class or 3463 // static data member of a class template shall be declared in the 3464 // namespace of which the class template is a member. 3465 // 3466 // C++0x [temp.expl.spec]p2: 3467 // An explicit specialization shall be declared in a namespace enclosing 3468 // the specialized template. 3469 if (!DC->InEnclosingNamespaceSetOf(SpecializedContext) && 3470 !(S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext))) { 3471 bool IsCPlusPlus0xExtension 3472 = !S.getLangOptions().CPlusPlus0x && DC->Encloses(SpecializedContext); 3473 if (isa<TranslationUnitDecl>(SpecializedContext)) 3474 S.Diag(Loc, IsCPlusPlus0xExtension 3475 ? diag::ext_template_spec_decl_out_of_scope_global 3476 : diag::err_template_spec_decl_out_of_scope_global) 3477 << EntityKind << Specialized; 3478 else if (isa<NamespaceDecl>(SpecializedContext)) 3479 S.Diag(Loc, IsCPlusPlus0xExtension 3480 ? diag::ext_template_spec_decl_out_of_scope 3481 : diag::err_template_spec_decl_out_of_scope) 3482 << EntityKind << Specialized 3483 << cast<NamedDecl>(SpecializedContext); 3484 3485 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3486 ComplainedAboutScope = true; 3487 } 3488 } 3489 3490 // Make sure that this redeclaration (or definition) occurs in an enclosing 3491 // namespace. 3492 // Note that HandleDeclarator() performs this check for explicit 3493 // specializations of function templates, static data members, and member 3494 // functions, so we skip the check here for those kinds of entities. 3495 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. 3496 // Should we refactor that check, so that it occurs later? 3497 if (!ComplainedAboutScope && !DC->Encloses(SpecializedContext) && 3498 !(isa<FunctionTemplateDecl>(Specialized) || isa<VarDecl>(Specialized) || 3499 isa<FunctionDecl>(Specialized))) { 3500 if (isa<TranslationUnitDecl>(SpecializedContext)) 3501 S.Diag(Loc, diag::err_template_spec_redecl_global_scope) 3502 << EntityKind << Specialized; 3503 else if (isa<NamespaceDecl>(SpecializedContext)) 3504 S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope) 3505 << EntityKind << Specialized 3506 << cast<NamedDecl>(SpecializedContext); 3507 3508 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 3509 } 3510 3511 // FIXME: check for specialization-after-instantiation errors and such. 3512 3513 return false; 3514} 3515 3516/// \brief Check the non-type template arguments of a class template 3517/// partial specialization according to C++ [temp.class.spec]p9. 3518/// 3519/// \param TemplateParams the template parameters of the primary class 3520/// template. 3521/// 3522/// \param TemplateArg the template arguments of the class template 3523/// partial specialization. 3524/// 3525/// \param MirrorsPrimaryTemplate will be set true if the class 3526/// template partial specialization arguments are identical to the 3527/// implicit template arguments of the primary template. This is not 3528/// necessarily an error (C++0x), and it is left to the caller to diagnose 3529/// this condition when it is an error. 3530/// 3531/// \returns true if there was an error, false otherwise. 3532bool Sema::CheckClassTemplatePartialSpecializationArgs( 3533 TemplateParameterList *TemplateParams, 3534 const TemplateArgumentListBuilder &TemplateArgs, 3535 bool &MirrorsPrimaryTemplate) { 3536 // FIXME: the interface to this function will have to change to 3537 // accommodate variadic templates. 3538 MirrorsPrimaryTemplate = true; 3539 3540 const TemplateArgument *ArgList = TemplateArgs.getFlatArguments(); 3541 3542 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 3543 // Determine whether the template argument list of the partial 3544 // specialization is identical to the implicit argument list of 3545 // the primary template. The caller may need to diagnostic this as 3546 // an error per C++ [temp.class.spec]p9b3. 3547 if (MirrorsPrimaryTemplate) { 3548 if (TemplateTypeParmDecl *TTP 3549 = dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(I))) { 3550 if (Context.getCanonicalType(Context.getTypeDeclType(TTP)) != 3551 Context.getCanonicalType(ArgList[I].getAsType())) 3552 MirrorsPrimaryTemplate = false; 3553 } else if (TemplateTemplateParmDecl *TTP 3554 = dyn_cast<TemplateTemplateParmDecl>( 3555 TemplateParams->getParam(I))) { 3556 TemplateName Name = ArgList[I].getAsTemplate(); 3557 TemplateTemplateParmDecl *ArgDecl 3558 = dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()); 3559 if (!ArgDecl || 3560 ArgDecl->getIndex() != TTP->getIndex() || 3561 ArgDecl->getDepth() != TTP->getDepth()) 3562 MirrorsPrimaryTemplate = false; 3563 } 3564 } 3565 3566 NonTypeTemplateParmDecl *Param 3567 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I)); 3568 if (!Param) { 3569 continue; 3570 } 3571 3572 Expr *ArgExpr = ArgList[I].getAsExpr(); 3573 if (!ArgExpr) { 3574 MirrorsPrimaryTemplate = false; 3575 continue; 3576 } 3577 3578 // C++ [temp.class.spec]p8: 3579 // A non-type argument is non-specialized if it is the name of a 3580 // non-type parameter. All other non-type arguments are 3581 // specialized. 3582 // 3583 // Below, we check the two conditions that only apply to 3584 // specialized non-type arguments, so skip any non-specialized 3585 // arguments. 3586 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr)) 3587 if (NonTypeTemplateParmDecl *NTTP 3588 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl())) { 3589 if (MirrorsPrimaryTemplate && 3590 (Param->getIndex() != NTTP->getIndex() || 3591 Param->getDepth() != NTTP->getDepth())) 3592 MirrorsPrimaryTemplate = false; 3593 3594 continue; 3595 } 3596 3597 // C++ [temp.class.spec]p9: 3598 // Within the argument list of a class template partial 3599 // specialization, the following restrictions apply: 3600 // -- A partially specialized non-type argument expression 3601 // shall not involve a template parameter of the partial 3602 // specialization except when the argument expression is a 3603 // simple identifier. 3604 if (ArgExpr->isTypeDependent() || ArgExpr->isValueDependent()) { 3605 Diag(ArgExpr->getLocStart(), 3606 diag::err_dependent_non_type_arg_in_partial_spec) 3607 << ArgExpr->getSourceRange(); 3608 return true; 3609 } 3610 3611 // -- The type of a template parameter corresponding to a 3612 // specialized non-type argument shall not be dependent on a 3613 // parameter of the specialization. 3614 if (Param->getType()->isDependentType()) { 3615 Diag(ArgExpr->getLocStart(), 3616 diag::err_dependent_typed_non_type_arg_in_partial_spec) 3617 << Param->getType() 3618 << ArgExpr->getSourceRange(); 3619 Diag(Param->getLocation(), diag::note_template_param_here); 3620 return true; 3621 } 3622 3623 MirrorsPrimaryTemplate = false; 3624 } 3625 3626 return false; 3627} 3628 3629/// \brief Retrieve the previous declaration of the given declaration. 3630static NamedDecl *getPreviousDecl(NamedDecl *ND) { 3631 if (VarDecl *VD = dyn_cast<VarDecl>(ND)) 3632 return VD->getPreviousDeclaration(); 3633 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 3634 return FD->getPreviousDeclaration(); 3635 if (TagDecl *TD = dyn_cast<TagDecl>(ND)) 3636 return TD->getPreviousDeclaration(); 3637 if (TypedefDecl *TD = dyn_cast<TypedefDecl>(ND)) 3638 return TD->getPreviousDeclaration(); 3639 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 3640 return FTD->getPreviousDeclaration(); 3641 if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND)) 3642 return CTD->getPreviousDeclaration(); 3643 return 0; 3644} 3645 3646DeclResult 3647Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, 3648 TagUseKind TUK, 3649 SourceLocation KWLoc, 3650 CXXScopeSpec &SS, 3651 TemplateTy TemplateD, 3652 SourceLocation TemplateNameLoc, 3653 SourceLocation LAngleLoc, 3654 ASTTemplateArgsPtr TemplateArgsIn, 3655 SourceLocation RAngleLoc, 3656 AttributeList *Attr, 3657 MultiTemplateParamsArg TemplateParameterLists) { 3658 assert(TUK != TUK_Reference && "References are not specializations"); 3659 3660 // Find the class template we're specializing 3661 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 3662 ClassTemplateDecl *ClassTemplate 3663 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl()); 3664 3665 if (!ClassTemplate) { 3666 Diag(TemplateNameLoc, diag::err_not_class_template_specialization) 3667 << (Name.getAsTemplateDecl() && 3668 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())); 3669 return true; 3670 } 3671 3672 bool isExplicitSpecialization = false; 3673 bool isPartialSpecialization = false; 3674 3675 // Check the validity of the template headers that introduce this 3676 // template. 3677 // FIXME: We probably shouldn't complain about these headers for 3678 // friend declarations. 3679 bool Invalid = false; 3680 TemplateParameterList *TemplateParams 3681 = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, SS, 3682 (TemplateParameterList**)TemplateParameterLists.get(), 3683 TemplateParameterLists.size(), 3684 TUK == TUK_Friend, 3685 isExplicitSpecialization, 3686 Invalid); 3687 if (Invalid) 3688 return true; 3689 3690 unsigned NumMatchedTemplateParamLists = TemplateParameterLists.size(); 3691 if (TemplateParams) 3692 --NumMatchedTemplateParamLists; 3693 3694 if (TemplateParams && TemplateParams->size() > 0) { 3695 isPartialSpecialization = true; 3696 3697 // C++ [temp.class.spec]p10: 3698 // The template parameter list of a specialization shall not 3699 // contain default template argument values. 3700 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 3701 Decl *Param = TemplateParams->getParam(I); 3702 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) { 3703 if (TTP->hasDefaultArgument()) { 3704 Diag(TTP->getDefaultArgumentLoc(), 3705 diag::err_default_arg_in_partial_spec); 3706 TTP->removeDefaultArgument(); 3707 } 3708 } else if (NonTypeTemplateParmDecl *NTTP 3709 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 3710 if (Expr *DefArg = NTTP->getDefaultArgument()) { 3711 Diag(NTTP->getDefaultArgumentLoc(), 3712 diag::err_default_arg_in_partial_spec) 3713 << DefArg->getSourceRange(); 3714 NTTP->removeDefaultArgument(); 3715 } 3716 } else { 3717 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param); 3718 if (TTP->hasDefaultArgument()) { 3719 Diag(TTP->getDefaultArgument().getLocation(), 3720 diag::err_default_arg_in_partial_spec) 3721 << TTP->getDefaultArgument().getSourceRange(); 3722 TTP->removeDefaultArgument(); 3723 } 3724 } 3725 } 3726 } else if (TemplateParams) { 3727 if (TUK == TUK_Friend) 3728 Diag(KWLoc, diag::err_template_spec_friend) 3729 << FixItHint::CreateRemoval( 3730 SourceRange(TemplateParams->getTemplateLoc(), 3731 TemplateParams->getRAngleLoc())) 3732 << SourceRange(LAngleLoc, RAngleLoc); 3733 else 3734 isExplicitSpecialization = true; 3735 } else if (TUK != TUK_Friend) { 3736 Diag(KWLoc, diag::err_template_spec_needs_header) 3737 << FixItHint::CreateInsertion(KWLoc, "template<> "); 3738 isExplicitSpecialization = true; 3739 } 3740 3741 // Check that the specialization uses the same tag kind as the 3742 // original template. 3743 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 3744 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!"); 3745 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 3746 Kind, KWLoc, 3747 *ClassTemplate->getIdentifier())) { 3748 Diag(KWLoc, diag::err_use_with_wrong_tag) 3749 << ClassTemplate 3750 << FixItHint::CreateReplacement(KWLoc, 3751 ClassTemplate->getTemplatedDecl()->getKindName()); 3752 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 3753 diag::note_previous_use); 3754 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 3755 } 3756 3757 // Translate the parser's template argument list in our AST format. 3758 TemplateArgumentListInfo TemplateArgs; 3759 TemplateArgs.setLAngleLoc(LAngleLoc); 3760 TemplateArgs.setRAngleLoc(RAngleLoc); 3761 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 3762 3763 // Check that the template argument list is well-formed for this 3764 // template. 3765 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 3766 TemplateArgs.size()); 3767 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 3768 TemplateArgs, false, Converted)) 3769 return true; 3770 3771 assert((Converted.structuredSize() == 3772 ClassTemplate->getTemplateParameters()->size()) && 3773 "Converted template argument list is too short!"); 3774 3775 // Find the class template (partial) specialization declaration that 3776 // corresponds to these arguments. 3777 if (isPartialSpecialization) { 3778 bool MirrorsPrimaryTemplate; 3779 if (CheckClassTemplatePartialSpecializationArgs( 3780 ClassTemplate->getTemplateParameters(), 3781 Converted, MirrorsPrimaryTemplate)) 3782 return true; 3783 3784 if (MirrorsPrimaryTemplate) { 3785 // C++ [temp.class.spec]p9b3: 3786 // 3787 // -- The argument list of the specialization shall not be identical 3788 // to the implicit argument list of the primary template. 3789 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 3790 << (TUK == TUK_Definition) 3791 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); 3792 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS, 3793 ClassTemplate->getIdentifier(), 3794 TemplateNameLoc, 3795 Attr, 3796 TemplateParams, 3797 AS_none); 3798 } 3799 3800 // FIXME: Diagnose friend partial specializations 3801 3802 if (!Name.isDependent() && 3803 !TemplateSpecializationType::anyDependentTemplateArguments( 3804 TemplateArgs.getArgumentArray(), 3805 TemplateArgs.size())) { 3806 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) 3807 << ClassTemplate->getDeclName(); 3808 isPartialSpecialization = false; 3809 } 3810 } 3811 3812 void *InsertPos = 0; 3813 ClassTemplateSpecializationDecl *PrevDecl = 0; 3814 3815 if (isPartialSpecialization) 3816 // FIXME: Template parameter list matters, too 3817 PrevDecl 3818 = ClassTemplate->findPartialSpecialization(Converted.getFlatArguments(), 3819 Converted.flatSize(), 3820 InsertPos); 3821 else 3822 PrevDecl 3823 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 3824 Converted.flatSize(), InsertPos); 3825 3826 ClassTemplateSpecializationDecl *Specialization = 0; 3827 3828 // Check whether we can declare a class template specialization in 3829 // the current scope. 3830 if (TUK != TUK_Friend && 3831 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl, 3832 TemplateNameLoc, 3833 isPartialSpecialization)) 3834 return true; 3835 3836 // The canonical type 3837 QualType CanonType; 3838 if (PrevDecl && 3839 (PrevDecl->getSpecializationKind() == TSK_Undeclared || 3840 TUK == TUK_Friend)) { 3841 // Since the only prior class template specialization with these 3842 // arguments was referenced but not declared, or we're only 3843 // referencing this specialization as a friend, reuse that 3844 // declaration node as our own, updating its source location to 3845 // reflect our new declaration. 3846 Specialization = PrevDecl; 3847 Specialization->setLocation(TemplateNameLoc); 3848 PrevDecl = 0; 3849 CanonType = Context.getTypeDeclType(Specialization); 3850 } else if (isPartialSpecialization) { 3851 // Build the canonical type that describes the converted template 3852 // arguments of the class template partial specialization. 3853 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 3854 CanonType = Context.getTemplateSpecializationType(CanonTemplate, 3855 Converted.getFlatArguments(), 3856 Converted.flatSize()); 3857 3858 // Create a new class template partial specialization declaration node. 3859 ClassTemplatePartialSpecializationDecl *PrevPartial 3860 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl); 3861 unsigned SequenceNumber = PrevPartial? PrevPartial->getSequenceNumber() 3862 : ClassTemplate->getNextPartialSpecSequenceNumber(); 3863 ClassTemplatePartialSpecializationDecl *Partial 3864 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind, 3865 ClassTemplate->getDeclContext(), 3866 TemplateNameLoc, 3867 TemplateParams, 3868 ClassTemplate, 3869 Converted, 3870 TemplateArgs, 3871 CanonType, 3872 PrevPartial, 3873 SequenceNumber); 3874 SetNestedNameSpecifier(Partial, SS); 3875 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 3876 Partial->setTemplateParameterListsInfo(Context, 3877 NumMatchedTemplateParamLists, 3878 (TemplateParameterList**) TemplateParameterLists.release()); 3879 } 3880 3881 if (!PrevPartial) 3882 ClassTemplate->AddPartialSpecialization(Partial, InsertPos); 3883 Specialization = Partial; 3884 3885 // If we are providing an explicit specialization of a member class 3886 // template specialization, make a note of that. 3887 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 3888 PrevPartial->setMemberSpecialization(); 3889 3890 // Check that all of the template parameters of the class template 3891 // partial specialization are deducible from the template 3892 // arguments. If not, this class template partial specialization 3893 // will never be used. 3894 llvm::SmallVector<bool, 8> DeducibleParams; 3895 DeducibleParams.resize(TemplateParams->size()); 3896 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 3897 TemplateParams->getDepth(), 3898 DeducibleParams); 3899 unsigned NumNonDeducible = 0; 3900 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) 3901 if (!DeducibleParams[I]) 3902 ++NumNonDeducible; 3903 3904 if (NumNonDeducible) { 3905 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 3906 << (NumNonDeducible > 1) 3907 << SourceRange(TemplateNameLoc, RAngleLoc); 3908 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 3909 if (!DeducibleParams[I]) { 3910 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 3911 if (Param->getDeclName()) 3912 Diag(Param->getLocation(), 3913 diag::note_partial_spec_unused_parameter) 3914 << Param->getDeclName(); 3915 else 3916 Diag(Param->getLocation(), 3917 diag::note_partial_spec_unused_parameter) 3918 << "<anonymous>"; 3919 } 3920 } 3921 } 3922 } else { 3923 // Create a new class template specialization declaration node for 3924 // this explicit specialization or friend declaration. 3925 Specialization 3926 = ClassTemplateSpecializationDecl::Create(Context, Kind, 3927 ClassTemplate->getDeclContext(), 3928 TemplateNameLoc, 3929 ClassTemplate, 3930 Converted, 3931 PrevDecl); 3932 SetNestedNameSpecifier(Specialization, SS); 3933 if (NumMatchedTemplateParamLists > 0 && SS.isSet()) { 3934 Specialization->setTemplateParameterListsInfo(Context, 3935 NumMatchedTemplateParamLists, 3936 (TemplateParameterList**) TemplateParameterLists.release()); 3937 } 3938 3939 if (!PrevDecl) 3940 ClassTemplate->AddSpecialization(Specialization, InsertPos); 3941 3942 CanonType = Context.getTypeDeclType(Specialization); 3943 } 3944 3945 // C++ [temp.expl.spec]p6: 3946 // If a template, a member template or the member of a class template is 3947 // explicitly specialized then that specialization shall be declared 3948 // before the first use of that specialization that would cause an implicit 3949 // instantiation to take place, in every translation unit in which such a 3950 // use occurs; no diagnostic is required. 3951 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 3952 bool Okay = false; 3953 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 3954 // Is there any previous explicit specialization declaration? 3955 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { 3956 Okay = true; 3957 break; 3958 } 3959 } 3960 3961 if (!Okay) { 3962 SourceRange Range(TemplateNameLoc, RAngleLoc); 3963 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 3964 << Context.getTypeDeclType(Specialization) << Range; 3965 3966 Diag(PrevDecl->getPointOfInstantiation(), 3967 diag::note_instantiation_required_here) 3968 << (PrevDecl->getTemplateSpecializationKind() 3969 != TSK_ImplicitInstantiation); 3970 return true; 3971 } 3972 } 3973 3974 // If this is not a friend, note that this is an explicit specialization. 3975 if (TUK != TUK_Friend) 3976 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 3977 3978 // Check that this isn't a redefinition of this specialization. 3979 if (TUK == TUK_Definition) { 3980 if (RecordDecl *Def = Specialization->getDefinition()) { 3981 SourceRange Range(TemplateNameLoc, RAngleLoc); 3982 Diag(TemplateNameLoc, diag::err_redefinition) 3983 << Context.getTypeDeclType(Specialization) << Range; 3984 Diag(Def->getLocation(), diag::note_previous_definition); 3985 Specialization->setInvalidDecl(); 3986 return true; 3987 } 3988 } 3989 3990 // Build the fully-sugared type for this class template 3991 // specialization as the user wrote in the specialization 3992 // itself. This means that we'll pretty-print the type retrieved 3993 // from the specialization's declaration the way that the user 3994 // actually wrote the specialization, rather than formatting the 3995 // name based on the "canonical" representation used to store the 3996 // template arguments in the specialization. 3997 TypeSourceInfo *WrittenTy 3998 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 3999 TemplateArgs, CanonType); 4000 if (TUK != TUK_Friend) { 4001 Specialization->setTypeAsWritten(WrittenTy); 4002 if (TemplateParams) 4003 Specialization->setTemplateKeywordLoc(TemplateParams->getTemplateLoc()); 4004 } 4005 TemplateArgsIn.release(); 4006 4007 // C++ [temp.expl.spec]p9: 4008 // A template explicit specialization is in the scope of the 4009 // namespace in which the template was defined. 4010 // 4011 // We actually implement this paragraph where we set the semantic 4012 // context (in the creation of the ClassTemplateSpecializationDecl), 4013 // but we also maintain the lexical context where the actual 4014 // definition occurs. 4015 Specialization->setLexicalDeclContext(CurContext); 4016 4017 // We may be starting the definition of this specialization. 4018 if (TUK == TUK_Definition) 4019 Specialization->startDefinition(); 4020 4021 if (TUK == TUK_Friend) { 4022 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 4023 TemplateNameLoc, 4024 WrittenTy, 4025 /*FIXME:*/KWLoc); 4026 Friend->setAccess(AS_public); 4027 CurContext->addDecl(Friend); 4028 } else { 4029 // Add the specialization into its lexical context, so that it can 4030 // be seen when iterating through the list of declarations in that 4031 // context. However, specializations are not found by name lookup. 4032 CurContext->addDecl(Specialization); 4033 } 4034 return Specialization; 4035} 4036 4037Decl *Sema::ActOnTemplateDeclarator(Scope *S, 4038 MultiTemplateParamsArg TemplateParameterLists, 4039 Declarator &D) { 4040 return HandleDeclarator(S, D, move(TemplateParameterLists), false); 4041} 4042 4043Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope, 4044 MultiTemplateParamsArg TemplateParameterLists, 4045 Declarator &D) { 4046 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 4047 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 4048 "Not a function declarator!"); 4049 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 4050 4051 if (FTI.hasPrototype) { 4052 // FIXME: Diagnose arguments without names in C. 4053 } 4054 4055 Scope *ParentScope = FnBodyScope->getParent(); 4056 4057 Decl *DP = HandleDeclarator(ParentScope, D, 4058 move(TemplateParameterLists), 4059 /*IsFunctionDefinition=*/true); 4060 if (FunctionTemplateDecl *FunctionTemplate 4061 = dyn_cast_or_null<FunctionTemplateDecl>(DP)) 4062 return ActOnStartOfFunctionDef(FnBodyScope, 4063 FunctionTemplate->getTemplatedDecl()); 4064 if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(DP)) 4065 return ActOnStartOfFunctionDef(FnBodyScope, Function); 4066 return 0; 4067} 4068 4069/// \brief Strips various properties off an implicit instantiation 4070/// that has just been explicitly specialized. 4071static void StripImplicitInstantiation(NamedDecl *D) { 4072 D->dropAttrs(); 4073 4074 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4075 FD->setInlineSpecified(false); 4076 } 4077} 4078 4079/// \brief Diagnose cases where we have an explicit template specialization 4080/// before/after an explicit template instantiation, producing diagnostics 4081/// for those cases where they are required and determining whether the 4082/// new specialization/instantiation will have any effect. 4083/// 4084/// \param NewLoc the location of the new explicit specialization or 4085/// instantiation. 4086/// 4087/// \param NewTSK the kind of the new explicit specialization or instantiation. 4088/// 4089/// \param PrevDecl the previous declaration of the entity. 4090/// 4091/// \param PrevTSK the kind of the old explicit specialization or instantiatin. 4092/// 4093/// \param PrevPointOfInstantiation if valid, indicates where the previus 4094/// declaration was instantiated (either implicitly or explicitly). 4095/// 4096/// \param HasNoEffect will be set to true to indicate that the new 4097/// specialization or instantiation has no effect and should be ignored. 4098/// 4099/// \returns true if there was an error that should prevent the introduction of 4100/// the new declaration into the AST, false otherwise. 4101bool 4102Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc, 4103 TemplateSpecializationKind NewTSK, 4104 NamedDecl *PrevDecl, 4105 TemplateSpecializationKind PrevTSK, 4106 SourceLocation PrevPointOfInstantiation, 4107 bool &HasNoEffect) { 4108 HasNoEffect = false; 4109 4110 switch (NewTSK) { 4111 case TSK_Undeclared: 4112 case TSK_ImplicitInstantiation: 4113 assert(false && "Don't check implicit instantiations here"); 4114 return false; 4115 4116 case TSK_ExplicitSpecialization: 4117 switch (PrevTSK) { 4118 case TSK_Undeclared: 4119 case TSK_ExplicitSpecialization: 4120 // Okay, we're just specializing something that is either already 4121 // explicitly specialized or has merely been mentioned without any 4122 // instantiation. 4123 return false; 4124 4125 case TSK_ImplicitInstantiation: 4126 if (PrevPointOfInstantiation.isInvalid()) { 4127 // The declaration itself has not actually been instantiated, so it is 4128 // still okay to specialize it. 4129 StripImplicitInstantiation(PrevDecl); 4130 return false; 4131 } 4132 // Fall through 4133 4134 case TSK_ExplicitInstantiationDeclaration: 4135 case TSK_ExplicitInstantiationDefinition: 4136 assert((PrevTSK == TSK_ImplicitInstantiation || 4137 PrevPointOfInstantiation.isValid()) && 4138 "Explicit instantiation without point of instantiation?"); 4139 4140 // C++ [temp.expl.spec]p6: 4141 // If a template, a member template or the member of a class template 4142 // is explicitly specialized then that specialization shall be declared 4143 // before the first use of that specialization that would cause an 4144 // implicit instantiation to take place, in every translation unit in 4145 // which such a use occurs; no diagnostic is required. 4146 for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) { 4147 // Is there any previous explicit specialization declaration? 4148 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) 4149 return false; 4150 } 4151 4152 Diag(NewLoc, diag::err_specialization_after_instantiation) 4153 << PrevDecl; 4154 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here) 4155 << (PrevTSK != TSK_ImplicitInstantiation); 4156 4157 return true; 4158 } 4159 break; 4160 4161 case TSK_ExplicitInstantiationDeclaration: 4162 switch (PrevTSK) { 4163 case TSK_ExplicitInstantiationDeclaration: 4164 // This explicit instantiation declaration is redundant (that's okay). 4165 HasNoEffect = true; 4166 return false; 4167 4168 case TSK_Undeclared: 4169 case TSK_ImplicitInstantiation: 4170 // We're explicitly instantiating something that may have already been 4171 // implicitly instantiated; that's fine. 4172 return false; 4173 4174 case TSK_ExplicitSpecialization: 4175 // C++0x [temp.explicit]p4: 4176 // For a given set of template parameters, if an explicit instantiation 4177 // of a template appears after a declaration of an explicit 4178 // specialization for that template, the explicit instantiation has no 4179 // effect. 4180 HasNoEffect = true; 4181 return false; 4182 4183 case TSK_ExplicitInstantiationDefinition: 4184 // C++0x [temp.explicit]p10: 4185 // If an entity is the subject of both an explicit instantiation 4186 // declaration and an explicit instantiation definition in the same 4187 // translation unit, the definition shall follow the declaration. 4188 Diag(NewLoc, 4189 diag::err_explicit_instantiation_declaration_after_definition); 4190 Diag(PrevPointOfInstantiation, 4191 diag::note_explicit_instantiation_definition_here); 4192 assert(PrevPointOfInstantiation.isValid() && 4193 "Explicit instantiation without point of instantiation?"); 4194 HasNoEffect = true; 4195 return false; 4196 } 4197 break; 4198 4199 case TSK_ExplicitInstantiationDefinition: 4200 switch (PrevTSK) { 4201 case TSK_Undeclared: 4202 case TSK_ImplicitInstantiation: 4203 // We're explicitly instantiating something that may have already been 4204 // implicitly instantiated; that's fine. 4205 return false; 4206 4207 case TSK_ExplicitSpecialization: 4208 // C++ DR 259, C++0x [temp.explicit]p4: 4209 // For a given set of template parameters, if an explicit 4210 // instantiation of a template appears after a declaration of 4211 // an explicit specialization for that template, the explicit 4212 // instantiation has no effect. 4213 // 4214 // In C++98/03 mode, we only give an extension warning here, because it 4215 // is not harmful to try to explicitly instantiate something that 4216 // has been explicitly specialized. 4217 if (!getLangOptions().CPlusPlus0x) { 4218 Diag(NewLoc, diag::ext_explicit_instantiation_after_specialization) 4219 << PrevDecl; 4220 Diag(PrevDecl->getLocation(), 4221 diag::note_previous_template_specialization); 4222 } 4223 HasNoEffect = true; 4224 return false; 4225 4226 case TSK_ExplicitInstantiationDeclaration: 4227 // We're explicity instantiating a definition for something for which we 4228 // were previously asked to suppress instantiations. That's fine. 4229 return false; 4230 4231 case TSK_ExplicitInstantiationDefinition: 4232 // C++0x [temp.spec]p5: 4233 // For a given template and a given set of template-arguments, 4234 // - an explicit instantiation definition shall appear at most once 4235 // in a program, 4236 Diag(NewLoc, diag::err_explicit_instantiation_duplicate) 4237 << PrevDecl; 4238 Diag(PrevPointOfInstantiation, 4239 diag::note_previous_explicit_instantiation); 4240 HasNoEffect = true; 4241 return false; 4242 } 4243 break; 4244 } 4245 4246 assert(false && "Missing specialization/instantiation case?"); 4247 4248 return false; 4249} 4250 4251/// \brief Perform semantic analysis for the given dependent function 4252/// template specialization. The only possible way to get a dependent 4253/// function template specialization is with a friend declaration, 4254/// like so: 4255/// 4256/// template <class T> void foo(T); 4257/// template <class T> class A { 4258/// friend void foo<>(T); 4259/// }; 4260/// 4261/// There really isn't any useful analysis we can do here, so we 4262/// just store the information. 4263bool 4264Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD, 4265 const TemplateArgumentListInfo &ExplicitTemplateArgs, 4266 LookupResult &Previous) { 4267 // Remove anything from Previous that isn't a function template in 4268 // the correct context. 4269 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4270 LookupResult::Filter F = Previous.makeFilter(); 4271 while (F.hasNext()) { 4272 NamedDecl *D = F.next()->getUnderlyingDecl(); 4273 if (!isa<FunctionTemplateDecl>(D) || 4274 !FDLookupContext->InEnclosingNamespaceSetOf( 4275 D->getDeclContext()->getRedeclContext())) 4276 F.erase(); 4277 } 4278 F.done(); 4279 4280 // Should this be diagnosed here? 4281 if (Previous.empty()) return true; 4282 4283 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(), 4284 ExplicitTemplateArgs); 4285 return false; 4286} 4287 4288/// \brief Perform semantic analysis for the given function template 4289/// specialization. 4290/// 4291/// This routine performs all of the semantic analysis required for an 4292/// explicit function template specialization. On successful completion, 4293/// the function declaration \p FD will become a function template 4294/// specialization. 4295/// 4296/// \param FD the function declaration, which will be updated to become a 4297/// function template specialization. 4298/// 4299/// \param ExplicitTemplateArgs the explicitly-provided template arguments, 4300/// if any. Note that this may be valid info even when 0 arguments are 4301/// explicitly provided as in, e.g., \c void sort<>(char*, char*); 4302/// as it anyway contains info on the angle brackets locations. 4303/// 4304/// \param PrevDecl the set of declarations that may be specialized by 4305/// this function specialization. 4306bool 4307Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD, 4308 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4309 LookupResult &Previous) { 4310 // The set of function template specializations that could match this 4311 // explicit function template specialization. 4312 UnresolvedSet<8> Candidates; 4313 4314 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext(); 4315 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 4316 I != E; ++I) { 4317 NamedDecl *Ovl = (*I)->getUnderlyingDecl(); 4318 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) { 4319 // Only consider templates found within the same semantic lookup scope as 4320 // FD. 4321 if (!FDLookupContext->InEnclosingNamespaceSetOf( 4322 Ovl->getDeclContext()->getRedeclContext())) 4323 continue; 4324 4325 // C++ [temp.expl.spec]p11: 4326 // A trailing template-argument can be left unspecified in the 4327 // template-id naming an explicit function template specialization 4328 // provided it can be deduced from the function argument type. 4329 // Perform template argument deduction to determine whether we may be 4330 // specializing this template. 4331 // FIXME: It is somewhat wasteful to build 4332 TemplateDeductionInfo Info(Context, FD->getLocation()); 4333 FunctionDecl *Specialization = 0; 4334 if (TemplateDeductionResult TDK 4335 = DeduceTemplateArguments(FunTmpl, ExplicitTemplateArgs, 4336 FD->getType(), 4337 Specialization, 4338 Info)) { 4339 // FIXME: Template argument deduction failed; record why it failed, so 4340 // that we can provide nifty diagnostics. 4341 (void)TDK; 4342 continue; 4343 } 4344 4345 // Record this candidate. 4346 Candidates.addDecl(Specialization, I.getAccess()); 4347 } 4348 } 4349 4350 // Find the most specialized function template. 4351 UnresolvedSetIterator Result 4352 = getMostSpecialized(Candidates.begin(), Candidates.end(), 4353 TPOC_Other, FD->getLocation(), 4354 PDiag(diag::err_function_template_spec_no_match) 4355 << FD->getDeclName(), 4356 PDiag(diag::err_function_template_spec_ambiguous) 4357 << FD->getDeclName() << (ExplicitTemplateArgs != 0), 4358 PDiag(diag::note_function_template_spec_matched)); 4359 if (Result == Candidates.end()) 4360 return true; 4361 4362 // Ignore access information; it doesn't figure into redeclaration checking. 4363 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 4364 Specialization->setLocation(FD->getLocation()); 4365 4366 // FIXME: Check if the prior specialization has a point of instantiation. 4367 // If so, we have run afoul of . 4368 4369 // If this is a friend declaration, then we're not really declaring 4370 // an explicit specialization. 4371 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None); 4372 4373 // Check the scope of this explicit specialization. 4374 if (!isFriend && 4375 CheckTemplateSpecializationScope(*this, 4376 Specialization->getPrimaryTemplate(), 4377 Specialization, FD->getLocation(), 4378 false)) 4379 return true; 4380 4381 // C++ [temp.expl.spec]p6: 4382 // If a template, a member template or the member of a class template is 4383 // explicitly specialized then that specialization shall be declared 4384 // before the first use of that specialization that would cause an implicit 4385 // instantiation to take place, in every translation unit in which such a 4386 // use occurs; no diagnostic is required. 4387 FunctionTemplateSpecializationInfo *SpecInfo 4388 = Specialization->getTemplateSpecializationInfo(); 4389 assert(SpecInfo && "Function template specialization info missing?"); 4390 4391 bool HasNoEffect = false; 4392 if (!isFriend && 4393 CheckSpecializationInstantiationRedecl(FD->getLocation(), 4394 TSK_ExplicitSpecialization, 4395 Specialization, 4396 SpecInfo->getTemplateSpecializationKind(), 4397 SpecInfo->getPointOfInstantiation(), 4398 HasNoEffect)) 4399 return true; 4400 4401 // Mark the prior declaration as an explicit specialization, so that later 4402 // clients know that this is an explicit specialization. 4403 if (!isFriend) { 4404 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization); 4405 MarkUnusedFileScopedDecl(Specialization); 4406 } 4407 4408 // Turn the given function declaration into a function template 4409 // specialization, with the template arguments from the previous 4410 // specialization. 4411 // Take copies of (semantic and syntactic) template argument lists. 4412 const TemplateArgumentList* TemplArgs = new (Context) 4413 TemplateArgumentList(Specialization->getTemplateSpecializationArgs()); 4414 const TemplateArgumentListInfo* TemplArgsAsWritten = ExplicitTemplateArgs 4415 ? new (Context) TemplateArgumentListInfo(*ExplicitTemplateArgs) : 0; 4416 FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(), 4417 TemplArgs, /*InsertPos=*/0, 4418 SpecInfo->getTemplateSpecializationKind(), 4419 TemplArgsAsWritten); 4420 4421 // The "previous declaration" for this function template specialization is 4422 // the prior function template specialization. 4423 Previous.clear(); 4424 Previous.addDecl(Specialization); 4425 return false; 4426} 4427 4428/// \brief Perform semantic analysis for the given non-template member 4429/// specialization. 4430/// 4431/// This routine performs all of the semantic analysis required for an 4432/// explicit member function specialization. On successful completion, 4433/// the function declaration \p FD will become a member function 4434/// specialization. 4435/// 4436/// \param Member the member declaration, which will be updated to become a 4437/// specialization. 4438/// 4439/// \param Previous the set of declarations, one of which may be specialized 4440/// by this function specialization; the set will be modified to contain the 4441/// redeclared member. 4442bool 4443Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) { 4444 assert(!isa<TemplateDecl>(Member) && "Only for non-template members"); 4445 4446 // Try to find the member we are instantiating. 4447 NamedDecl *Instantiation = 0; 4448 NamedDecl *InstantiatedFrom = 0; 4449 MemberSpecializationInfo *MSInfo = 0; 4450 4451 if (Previous.empty()) { 4452 // Nowhere to look anyway. 4453 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) { 4454 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 4455 I != E; ++I) { 4456 NamedDecl *D = (*I)->getUnderlyingDecl(); 4457 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 4458 if (Context.hasSameType(Function->getType(), Method->getType())) { 4459 Instantiation = Method; 4460 InstantiatedFrom = Method->getInstantiatedFromMemberFunction(); 4461 MSInfo = Method->getMemberSpecializationInfo(); 4462 break; 4463 } 4464 } 4465 } 4466 } else if (isa<VarDecl>(Member)) { 4467 VarDecl *PrevVar; 4468 if (Previous.isSingleResult() && 4469 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl()))) 4470 if (PrevVar->isStaticDataMember()) { 4471 Instantiation = PrevVar; 4472 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember(); 4473 MSInfo = PrevVar->getMemberSpecializationInfo(); 4474 } 4475 } else if (isa<RecordDecl>(Member)) { 4476 CXXRecordDecl *PrevRecord; 4477 if (Previous.isSingleResult() && 4478 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) { 4479 Instantiation = PrevRecord; 4480 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass(); 4481 MSInfo = PrevRecord->getMemberSpecializationInfo(); 4482 } 4483 } 4484 4485 if (!Instantiation) { 4486 // There is no previous declaration that matches. Since member 4487 // specializations are always out-of-line, the caller will complain about 4488 // this mismatch later. 4489 return false; 4490 } 4491 4492 // If this is a friend, just bail out here before we start turning 4493 // things into explicit specializations. 4494 if (Member->getFriendObjectKind() != Decl::FOK_None) { 4495 // Preserve instantiation information. 4496 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) { 4497 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction( 4498 cast<CXXMethodDecl>(InstantiatedFrom), 4499 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind()); 4500 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) { 4501 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 4502 cast<CXXRecordDecl>(InstantiatedFrom), 4503 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind()); 4504 } 4505 4506 Previous.clear(); 4507 Previous.addDecl(Instantiation); 4508 return false; 4509 } 4510 4511 // Make sure that this is a specialization of a member. 4512 if (!InstantiatedFrom) { 4513 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated) 4514 << Member; 4515 Diag(Instantiation->getLocation(), diag::note_specialized_decl); 4516 return true; 4517 } 4518 4519 // C++ [temp.expl.spec]p6: 4520 // If a template, a member template or the member of a class template is 4521 // explicitly specialized then that spe- cialization shall be declared 4522 // before the first use of that specialization that would cause an implicit 4523 // instantiation to take place, in every translation unit in which such a 4524 // use occurs; no diagnostic is required. 4525 assert(MSInfo && "Member specialization info missing?"); 4526 4527 bool HasNoEffect = false; 4528 if (CheckSpecializationInstantiationRedecl(Member->getLocation(), 4529 TSK_ExplicitSpecialization, 4530 Instantiation, 4531 MSInfo->getTemplateSpecializationKind(), 4532 MSInfo->getPointOfInstantiation(), 4533 HasNoEffect)) 4534 return true; 4535 4536 // Check the scope of this explicit specialization. 4537 if (CheckTemplateSpecializationScope(*this, 4538 InstantiatedFrom, 4539 Instantiation, Member->getLocation(), 4540 false)) 4541 return true; 4542 4543 // Note that this is an explicit instantiation of a member. 4544 // the original declaration to note that it is an explicit specialization 4545 // (if it was previously an implicit instantiation). This latter step 4546 // makes bookkeeping easier. 4547 if (isa<FunctionDecl>(Member)) { 4548 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation); 4549 if (InstantiationFunction->getTemplateSpecializationKind() == 4550 TSK_ImplicitInstantiation) { 4551 InstantiationFunction->setTemplateSpecializationKind( 4552 TSK_ExplicitSpecialization); 4553 InstantiationFunction->setLocation(Member->getLocation()); 4554 } 4555 4556 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction( 4557 cast<CXXMethodDecl>(InstantiatedFrom), 4558 TSK_ExplicitSpecialization); 4559 MarkUnusedFileScopedDecl(InstantiationFunction); 4560 } else if (isa<VarDecl>(Member)) { 4561 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation); 4562 if (InstantiationVar->getTemplateSpecializationKind() == 4563 TSK_ImplicitInstantiation) { 4564 InstantiationVar->setTemplateSpecializationKind( 4565 TSK_ExplicitSpecialization); 4566 InstantiationVar->setLocation(Member->getLocation()); 4567 } 4568 4569 Context.setInstantiatedFromStaticDataMember(cast<VarDecl>(Member), 4570 cast<VarDecl>(InstantiatedFrom), 4571 TSK_ExplicitSpecialization); 4572 MarkUnusedFileScopedDecl(InstantiationVar); 4573 } else { 4574 assert(isa<CXXRecordDecl>(Member) && "Only member classes remain"); 4575 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation); 4576 if (InstantiationClass->getTemplateSpecializationKind() == 4577 TSK_ImplicitInstantiation) { 4578 InstantiationClass->setTemplateSpecializationKind( 4579 TSK_ExplicitSpecialization); 4580 InstantiationClass->setLocation(Member->getLocation()); 4581 } 4582 4583 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 4584 cast<CXXRecordDecl>(InstantiatedFrom), 4585 TSK_ExplicitSpecialization); 4586 } 4587 4588 // Save the caller the trouble of having to figure out which declaration 4589 // this specialization matches. 4590 Previous.clear(); 4591 Previous.addDecl(Instantiation); 4592 return false; 4593} 4594 4595/// \brief Check the scope of an explicit instantiation. 4596/// 4597/// \returns true if a serious error occurs, false otherwise. 4598static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D, 4599 SourceLocation InstLoc, 4600 bool WasQualifiedName) { 4601 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext(); 4602 DeclContext *CurContext = S.CurContext->getRedeclContext(); 4603 4604 if (CurContext->isRecord()) { 4605 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class) 4606 << D; 4607 return true; 4608 } 4609 4610 // C++0x [temp.explicit]p2: 4611 // An explicit instantiation shall appear in an enclosing namespace of its 4612 // template. 4613 // 4614 // This is DR275, which we do not retroactively apply to C++98/03. 4615 if (S.getLangOptions().CPlusPlus0x && 4616 !CurContext->Encloses(OrigContext)) { 4617 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) 4618 S.Diag(InstLoc, 4619 S.getLangOptions().CPlusPlus0x? 4620 diag::err_explicit_instantiation_out_of_scope 4621 : diag::warn_explicit_instantiation_out_of_scope_0x) 4622 << D << NS; 4623 else 4624 S.Diag(InstLoc, 4625 S.getLangOptions().CPlusPlus0x? 4626 diag::err_explicit_instantiation_must_be_global 4627 : diag::warn_explicit_instantiation_out_of_scope_0x) 4628 << D; 4629 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 4630 return false; 4631 } 4632 4633 // C++0x [temp.explicit]p2: 4634 // If the name declared in the explicit instantiation is an unqualified 4635 // name, the explicit instantiation shall appear in the namespace where 4636 // its template is declared or, if that namespace is inline (7.3.1), any 4637 // namespace from its enclosing namespace set. 4638 if (WasQualifiedName) 4639 return false; 4640 4641 if (CurContext->InEnclosingNamespaceSetOf(OrigContext)) 4642 return false; 4643 4644 S.Diag(InstLoc, 4645 S.getLangOptions().CPlusPlus0x? 4646 diag::err_explicit_instantiation_unqualified_wrong_namespace 4647 : diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x) 4648 << D << OrigContext; 4649 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 4650 return false; 4651} 4652 4653/// \brief Determine whether the given scope specifier has a template-id in it. 4654static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) { 4655 if (!SS.isSet()) 4656 return false; 4657 4658 // C++0x [temp.explicit]p2: 4659 // If the explicit instantiation is for a member function, a member class 4660 // or a static data member of a class template specialization, the name of 4661 // the class template specialization in the qualified-id for the member 4662 // name shall be a simple-template-id. 4663 // 4664 // C++98 has the same restriction, just worded differently. 4665 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 4666 NNS; NNS = NNS->getPrefix()) 4667 if (Type *T = NNS->getAsType()) 4668 if (isa<TemplateSpecializationType>(T)) 4669 return true; 4670 4671 return false; 4672} 4673 4674// Explicit instantiation of a class template specialization 4675DeclResult 4676Sema::ActOnExplicitInstantiation(Scope *S, 4677 SourceLocation ExternLoc, 4678 SourceLocation TemplateLoc, 4679 unsigned TagSpec, 4680 SourceLocation KWLoc, 4681 const CXXScopeSpec &SS, 4682 TemplateTy TemplateD, 4683 SourceLocation TemplateNameLoc, 4684 SourceLocation LAngleLoc, 4685 ASTTemplateArgsPtr TemplateArgsIn, 4686 SourceLocation RAngleLoc, 4687 AttributeList *Attr) { 4688 // Find the class template we're specializing 4689 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 4690 ClassTemplateDecl *ClassTemplate 4691 = cast<ClassTemplateDecl>(Name.getAsTemplateDecl()); 4692 4693 // Check that the specialization uses the same tag kind as the 4694 // original template. 4695 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 4696 assert(Kind != TTK_Enum && 4697 "Invalid enum tag in class template explicit instantiation!"); 4698 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 4699 Kind, KWLoc, 4700 *ClassTemplate->getIdentifier())) { 4701 Diag(KWLoc, diag::err_use_with_wrong_tag) 4702 << ClassTemplate 4703 << FixItHint::CreateReplacement(KWLoc, 4704 ClassTemplate->getTemplatedDecl()->getKindName()); 4705 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 4706 diag::note_previous_use); 4707 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 4708 } 4709 4710 // C++0x [temp.explicit]p2: 4711 // There are two forms of explicit instantiation: an explicit instantiation 4712 // definition and an explicit instantiation declaration. An explicit 4713 // instantiation declaration begins with the extern keyword. [...] 4714 TemplateSpecializationKind TSK 4715 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4716 : TSK_ExplicitInstantiationDeclaration; 4717 4718 // Translate the parser's template argument list in our AST format. 4719 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 4720 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 4721 4722 // Check that the template argument list is well-formed for this 4723 // template. 4724 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 4725 TemplateArgs.size()); 4726 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, 4727 TemplateArgs, false, Converted)) 4728 return true; 4729 4730 assert((Converted.structuredSize() == 4731 ClassTemplate->getTemplateParameters()->size()) && 4732 "Converted template argument list is too short!"); 4733 4734 // Find the class template specialization declaration that 4735 // corresponds to these arguments. 4736 void *InsertPos = 0; 4737 ClassTemplateSpecializationDecl *PrevDecl 4738 = ClassTemplate->findSpecialization(Converted.getFlatArguments(), 4739 Converted.flatSize(), InsertPos); 4740 4741 TemplateSpecializationKind PrevDecl_TSK 4742 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared; 4743 4744 // C++0x [temp.explicit]p2: 4745 // [...] An explicit instantiation shall appear in an enclosing 4746 // namespace of its template. [...] 4747 // 4748 // This is C++ DR 275. 4749 if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc, 4750 SS.isSet())) 4751 return true; 4752 4753 ClassTemplateSpecializationDecl *Specialization = 0; 4754 4755 bool ReusedDecl = false; 4756 bool HasNoEffect = false; 4757 if (PrevDecl) { 4758 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK, 4759 PrevDecl, PrevDecl_TSK, 4760 PrevDecl->getPointOfInstantiation(), 4761 HasNoEffect)) 4762 return PrevDecl; 4763 4764 // Even though HasNoEffect == true means that this explicit instantiation 4765 // has no effect on semantics, we go on to put its syntax in the AST. 4766 4767 if (PrevDecl_TSK == TSK_ImplicitInstantiation || 4768 PrevDecl_TSK == TSK_Undeclared) { 4769 // Since the only prior class template specialization with these 4770 // arguments was referenced but not declared, reuse that 4771 // declaration node as our own, updating the source location 4772 // for the template name to reflect our new declaration. 4773 // (Other source locations will be updated later.) 4774 Specialization = PrevDecl; 4775 Specialization->setLocation(TemplateNameLoc); 4776 PrevDecl = 0; 4777 ReusedDecl = true; 4778 } 4779 } 4780 4781 if (!Specialization) { 4782 // Create a new class template specialization declaration node for 4783 // this explicit specialization. 4784 Specialization 4785 = ClassTemplateSpecializationDecl::Create(Context, Kind, 4786 ClassTemplate->getDeclContext(), 4787 TemplateNameLoc, 4788 ClassTemplate, 4789 Converted, PrevDecl); 4790 SetNestedNameSpecifier(Specialization, SS); 4791 4792 if (!HasNoEffect && !PrevDecl) { 4793 // Insert the new specialization. 4794 ClassTemplate->AddSpecialization(Specialization, InsertPos); 4795 } 4796 } 4797 4798 // Build the fully-sugared type for this explicit instantiation as 4799 // the user wrote in the explicit instantiation itself. This means 4800 // that we'll pretty-print the type retrieved from the 4801 // specialization's declaration the way that the user actually wrote 4802 // the explicit instantiation, rather than formatting the name based 4803 // on the "canonical" representation used to store the template 4804 // arguments in the specialization. 4805 TypeSourceInfo *WrittenTy 4806 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc, 4807 TemplateArgs, 4808 Context.getTypeDeclType(Specialization)); 4809 Specialization->setTypeAsWritten(WrittenTy); 4810 TemplateArgsIn.release(); 4811 4812 // Set source locations for keywords. 4813 Specialization->setExternLoc(ExternLoc); 4814 Specialization->setTemplateKeywordLoc(TemplateLoc); 4815 4816 // Add the explicit instantiation into its lexical context. However, 4817 // since explicit instantiations are never found by name lookup, we 4818 // just put it into the declaration context directly. 4819 Specialization->setLexicalDeclContext(CurContext); 4820 CurContext->addDecl(Specialization); 4821 4822 // Syntax is now OK, so return if it has no other effect on semantics. 4823 if (HasNoEffect) { 4824 // Set the template specialization kind. 4825 Specialization->setTemplateSpecializationKind(TSK); 4826 return Specialization; 4827 } 4828 4829 // C++ [temp.explicit]p3: 4830 // A definition of a class template or class member template 4831 // shall be in scope at the point of the explicit instantiation of 4832 // the class template or class member template. 4833 // 4834 // This check comes when we actually try to perform the 4835 // instantiation. 4836 ClassTemplateSpecializationDecl *Def 4837 = cast_or_null<ClassTemplateSpecializationDecl>( 4838 Specialization->getDefinition()); 4839 if (!Def) 4840 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK); 4841 else if (TSK == TSK_ExplicitInstantiationDefinition) { 4842 MarkVTableUsed(TemplateNameLoc, Specialization, true); 4843 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation()); 4844 } 4845 4846 // Instantiate the members of this class template specialization. 4847 Def = cast_or_null<ClassTemplateSpecializationDecl>( 4848 Specialization->getDefinition()); 4849 if (Def) { 4850 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind(); 4851 4852 // Fix a TSK_ExplicitInstantiationDeclaration followed by a 4853 // TSK_ExplicitInstantiationDefinition 4854 if (Old_TSK == TSK_ExplicitInstantiationDeclaration && 4855 TSK == TSK_ExplicitInstantiationDefinition) 4856 Def->setTemplateSpecializationKind(TSK); 4857 4858 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK); 4859 } 4860 4861 // Set the template specialization kind. 4862 Specialization->setTemplateSpecializationKind(TSK); 4863 return Specialization; 4864} 4865 4866// Explicit instantiation of a member class of a class template. 4867DeclResult 4868Sema::ActOnExplicitInstantiation(Scope *S, 4869 SourceLocation ExternLoc, 4870 SourceLocation TemplateLoc, 4871 unsigned TagSpec, 4872 SourceLocation KWLoc, 4873 CXXScopeSpec &SS, 4874 IdentifierInfo *Name, 4875 SourceLocation NameLoc, 4876 AttributeList *Attr) { 4877 4878 bool Owned = false; 4879 bool IsDependent = false; 4880 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference, 4881 KWLoc, SS, Name, NameLoc, Attr, AS_none, 4882 MultiTemplateParamsArg(*this, 0, 0), 4883 Owned, IsDependent, false, 4884 TypeResult()); 4885 assert(!IsDependent && "explicit instantiation of dependent name not yet handled"); 4886 4887 if (!TagD) 4888 return true; 4889 4890 TagDecl *Tag = cast<TagDecl>(TagD); 4891 if (Tag->isEnum()) { 4892 Diag(TemplateLoc, diag::err_explicit_instantiation_enum) 4893 << Context.getTypeDeclType(Tag); 4894 return true; 4895 } 4896 4897 if (Tag->isInvalidDecl()) 4898 return true; 4899 4900 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag); 4901 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass(); 4902 if (!Pattern) { 4903 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type) 4904 << Context.getTypeDeclType(Record); 4905 Diag(Record->getLocation(), diag::note_nontemplate_decl_here); 4906 return true; 4907 } 4908 4909 // C++0x [temp.explicit]p2: 4910 // If the explicit instantiation is for a class or member class, the 4911 // elaborated-type-specifier in the declaration shall include a 4912 // simple-template-id. 4913 // 4914 // C++98 has the same restriction, just worded differently. 4915 if (!ScopeSpecifierHasTemplateId(SS)) 4916 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id) 4917 << Record << SS.getRange(); 4918 4919 // C++0x [temp.explicit]p2: 4920 // There are two forms of explicit instantiation: an explicit instantiation 4921 // definition and an explicit instantiation declaration. An explicit 4922 // instantiation declaration begins with the extern keyword. [...] 4923 TemplateSpecializationKind TSK 4924 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4925 : TSK_ExplicitInstantiationDeclaration; 4926 4927 // C++0x [temp.explicit]p2: 4928 // [...] An explicit instantiation shall appear in an enclosing 4929 // namespace of its template. [...] 4930 // 4931 // This is C++ DR 275. 4932 CheckExplicitInstantiationScope(*this, Record, NameLoc, true); 4933 4934 // Verify that it is okay to explicitly instantiate here. 4935 CXXRecordDecl *PrevDecl 4936 = cast_or_null<CXXRecordDecl>(Record->getPreviousDeclaration()); 4937 if (!PrevDecl && Record->getDefinition()) 4938 PrevDecl = Record; 4939 if (PrevDecl) { 4940 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo(); 4941 bool HasNoEffect = false; 4942 assert(MSInfo && "No member specialization information?"); 4943 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK, 4944 PrevDecl, 4945 MSInfo->getTemplateSpecializationKind(), 4946 MSInfo->getPointOfInstantiation(), 4947 HasNoEffect)) 4948 return true; 4949 if (HasNoEffect) 4950 return TagD; 4951 } 4952 4953 CXXRecordDecl *RecordDef 4954 = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 4955 if (!RecordDef) { 4956 // C++ [temp.explicit]p3: 4957 // A definition of a member class of a class template shall be in scope 4958 // at the point of an explicit instantiation of the member class. 4959 CXXRecordDecl *Def 4960 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition()); 4961 if (!Def) { 4962 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member) 4963 << 0 << Record->getDeclName() << Record->getDeclContext(); 4964 Diag(Pattern->getLocation(), diag::note_forward_declaration) 4965 << Pattern; 4966 return true; 4967 } else { 4968 if (InstantiateClass(NameLoc, Record, Def, 4969 getTemplateInstantiationArgs(Record), 4970 TSK)) 4971 return true; 4972 4973 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition()); 4974 if (!RecordDef) 4975 return true; 4976 } 4977 } 4978 4979 // Instantiate all of the members of the class. 4980 InstantiateClassMembers(NameLoc, RecordDef, 4981 getTemplateInstantiationArgs(Record), TSK); 4982 4983 if (TSK == TSK_ExplicitInstantiationDefinition) 4984 MarkVTableUsed(NameLoc, RecordDef, true); 4985 4986 // FIXME: We don't have any representation for explicit instantiations of 4987 // member classes. Such a representation is not needed for compilation, but it 4988 // should be available for clients that want to see all of the declarations in 4989 // the source code. 4990 return TagD; 4991} 4992 4993DeclResult Sema::ActOnExplicitInstantiation(Scope *S, 4994 SourceLocation ExternLoc, 4995 SourceLocation TemplateLoc, 4996 Declarator &D) { 4997 // Explicit instantiations always require a name. 4998 // TODO: check if/when DNInfo should replace Name. 4999 DeclarationNameInfo NameInfo = GetNameForDeclarator(D); 5000 DeclarationName Name = NameInfo.getName(); 5001 if (!Name) { 5002 if (!D.isInvalidType()) 5003 Diag(D.getDeclSpec().getSourceRange().getBegin(), 5004 diag::err_explicit_instantiation_requires_name) 5005 << D.getDeclSpec().getSourceRange() 5006 << D.getSourceRange(); 5007 5008 return true; 5009 } 5010 5011 // The scope passed in may not be a decl scope. Zip up the scope tree until 5012 // we find one that is. 5013 while ((S->getFlags() & Scope::DeclScope) == 0 || 5014 (S->getFlags() & Scope::TemplateParamScope) != 0) 5015 S = S->getParent(); 5016 5017 // Determine the type of the declaration. 5018 TypeSourceInfo *T = GetTypeForDeclarator(D, S); 5019 QualType R = T->getType(); 5020 if (R.isNull()) 5021 return true; 5022 5023 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 5024 // Cannot explicitly instantiate a typedef. 5025 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef) 5026 << Name; 5027 return true; 5028 } 5029 5030 // C++0x [temp.explicit]p1: 5031 // [...] An explicit instantiation of a function template shall not use the 5032 // inline or constexpr specifiers. 5033 // Presumably, this also applies to member functions of class templates as 5034 // well. 5035 if (D.getDeclSpec().isInlineSpecified() && getLangOptions().CPlusPlus0x) 5036 Diag(D.getDeclSpec().getInlineSpecLoc(), 5037 diag::err_explicit_instantiation_inline) 5038 <<FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); 5039 5040 // FIXME: check for constexpr specifier. 5041 5042 // C++0x [temp.explicit]p2: 5043 // There are two forms of explicit instantiation: an explicit instantiation 5044 // definition and an explicit instantiation declaration. An explicit 5045 // instantiation declaration begins with the extern keyword. [...] 5046 TemplateSpecializationKind TSK 5047 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 5048 : TSK_ExplicitInstantiationDeclaration; 5049 5050 LookupResult Previous(*this, NameInfo, LookupOrdinaryName); 5051 LookupParsedName(Previous, S, &D.getCXXScopeSpec()); 5052 5053 if (!R->isFunctionType()) { 5054 // C++ [temp.explicit]p1: 5055 // A [...] static data member of a class template can be explicitly 5056 // instantiated from the member definition associated with its class 5057 // template. 5058 if (Previous.isAmbiguous()) 5059 return true; 5060 5061 VarDecl *Prev = Previous.getAsSingle<VarDecl>(); 5062 if (!Prev || !Prev->isStaticDataMember()) { 5063 // We expect to see a data data member here. 5064 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known) 5065 << Name; 5066 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5067 P != PEnd; ++P) 5068 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here); 5069 return true; 5070 } 5071 5072 if (!Prev->getInstantiatedFromStaticDataMember()) { 5073 // FIXME: Check for explicit specialization? 5074 Diag(D.getIdentifierLoc(), 5075 diag::err_explicit_instantiation_data_member_not_instantiated) 5076 << Prev; 5077 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here); 5078 // FIXME: Can we provide a note showing where this was declared? 5079 return true; 5080 } 5081 5082 // C++0x [temp.explicit]p2: 5083 // If the explicit instantiation is for a member function, a member class 5084 // or a static data member of a class template specialization, the name of 5085 // the class template specialization in the qualified-id for the member 5086 // name shall be a simple-template-id. 5087 // 5088 // C++98 has the same restriction, just worded differently. 5089 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5090 Diag(D.getIdentifierLoc(), 5091 diag::ext_explicit_instantiation_without_qualified_id) 5092 << Prev << D.getCXXScopeSpec().getRange(); 5093 5094 // Check the scope of this explicit instantiation. 5095 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true); 5096 5097 // Verify that it is okay to explicitly instantiate here. 5098 MemberSpecializationInfo *MSInfo = Prev->getMemberSpecializationInfo(); 5099 assert(MSInfo && "Missing static data member specialization info?"); 5100 bool HasNoEffect = false; 5101 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev, 5102 MSInfo->getTemplateSpecializationKind(), 5103 MSInfo->getPointOfInstantiation(), 5104 HasNoEffect)) 5105 return true; 5106 if (HasNoEffect) 5107 return (Decl*) 0; 5108 5109 // Instantiate static data member. 5110 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5111 if (TSK == TSK_ExplicitInstantiationDefinition) 5112 InstantiateStaticDataMemberDefinition(D.getIdentifierLoc(), Prev); 5113 5114 // FIXME: Create an ExplicitInstantiation node? 5115 return (Decl*) 0; 5116 } 5117 5118 // If the declarator is a template-id, translate the parser's template 5119 // argument list into our AST format. 5120 bool HasExplicitTemplateArgs = false; 5121 TemplateArgumentListInfo TemplateArgs; 5122 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 5123 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 5124 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); 5125 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); 5126 ASTTemplateArgsPtr TemplateArgsPtr(*this, 5127 TemplateId->getTemplateArgs(), 5128 TemplateId->NumArgs); 5129 translateTemplateArguments(TemplateArgsPtr, TemplateArgs); 5130 HasExplicitTemplateArgs = true; 5131 TemplateArgsPtr.release(); 5132 } 5133 5134 // C++ [temp.explicit]p1: 5135 // A [...] function [...] can be explicitly instantiated from its template. 5136 // A member function [...] of a class template can be explicitly 5137 // instantiated from the member definition associated with its class 5138 // template. 5139 UnresolvedSet<8> Matches; 5140 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 5141 P != PEnd; ++P) { 5142 NamedDecl *Prev = *P; 5143 if (!HasExplicitTemplateArgs) { 5144 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) { 5145 if (Context.hasSameUnqualifiedType(Method->getType(), R)) { 5146 Matches.clear(); 5147 5148 Matches.addDecl(Method, P.getAccess()); 5149 if (Method->getTemplateSpecializationKind() == TSK_Undeclared) 5150 break; 5151 } 5152 } 5153 } 5154 5155 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev); 5156 if (!FunTmpl) 5157 continue; 5158 5159 TemplateDeductionInfo Info(Context, D.getIdentifierLoc()); 5160 FunctionDecl *Specialization = 0; 5161 if (TemplateDeductionResult TDK 5162 = DeduceTemplateArguments(FunTmpl, 5163 (HasExplicitTemplateArgs ? &TemplateArgs : 0), 5164 R, Specialization, Info)) { 5165 // FIXME: Keep track of almost-matches? 5166 (void)TDK; 5167 continue; 5168 } 5169 5170 Matches.addDecl(Specialization, P.getAccess()); 5171 } 5172 5173 // Find the most specialized function template specialization. 5174 UnresolvedSetIterator Result 5175 = getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other, 5176 D.getIdentifierLoc(), 5177 PDiag(diag::err_explicit_instantiation_not_known) << Name, 5178 PDiag(diag::err_explicit_instantiation_ambiguous) << Name, 5179 PDiag(diag::note_explicit_instantiation_candidate)); 5180 5181 if (Result == Matches.end()) 5182 return true; 5183 5184 // Ignore access control bits, we don't need them for redeclaration checking. 5185 FunctionDecl *Specialization = cast<FunctionDecl>(*Result); 5186 5187 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) { 5188 Diag(D.getIdentifierLoc(), 5189 diag::err_explicit_instantiation_member_function_not_instantiated) 5190 << Specialization 5191 << (Specialization->getTemplateSpecializationKind() == 5192 TSK_ExplicitSpecialization); 5193 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here); 5194 return true; 5195 } 5196 5197 FunctionDecl *PrevDecl = Specialization->getPreviousDeclaration(); 5198 if (!PrevDecl && Specialization->isThisDeclarationADefinition()) 5199 PrevDecl = Specialization; 5200 5201 if (PrevDecl) { 5202 bool HasNoEffect = false; 5203 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, 5204 PrevDecl, 5205 PrevDecl->getTemplateSpecializationKind(), 5206 PrevDecl->getPointOfInstantiation(), 5207 HasNoEffect)) 5208 return true; 5209 5210 // FIXME: We may still want to build some representation of this 5211 // explicit specialization. 5212 if (HasNoEffect) 5213 return (Decl*) 0; 5214 } 5215 5216 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 5217 5218 if (TSK == TSK_ExplicitInstantiationDefinition) 5219 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization); 5220 5221 // C++0x [temp.explicit]p2: 5222 // If the explicit instantiation is for a member function, a member class 5223 // or a static data member of a class template specialization, the name of 5224 // the class template specialization in the qualified-id for the member 5225 // name shall be a simple-template-id. 5226 // 5227 // C++98 has the same restriction, just worded differently. 5228 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate(); 5229 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl && 5230 D.getCXXScopeSpec().isSet() && 5231 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 5232 Diag(D.getIdentifierLoc(), 5233 diag::ext_explicit_instantiation_without_qualified_id) 5234 << Specialization << D.getCXXScopeSpec().getRange(); 5235 5236 CheckExplicitInstantiationScope(*this, 5237 FunTmpl? (NamedDecl *)FunTmpl 5238 : Specialization->getInstantiatedFromMemberFunction(), 5239 D.getIdentifierLoc(), 5240 D.getCXXScopeSpec().isSet()); 5241 5242 // FIXME: Create some kind of ExplicitInstantiationDecl here. 5243 return (Decl*) 0; 5244} 5245 5246TypeResult 5247Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 5248 const CXXScopeSpec &SS, IdentifierInfo *Name, 5249 SourceLocation TagLoc, SourceLocation NameLoc) { 5250 // This has to hold, because SS is expected to be defined. 5251 assert(Name && "Expected a name in a dependent tag"); 5252 5253 NestedNameSpecifier *NNS 5254 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5255 if (!NNS) 5256 return true; 5257 5258 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 5259 5260 if (TUK == TUK_Declaration || TUK == TUK_Definition) { 5261 Diag(NameLoc, diag::err_dependent_tag_decl) 5262 << (TUK == TUK_Definition) << Kind << SS.getRange(); 5263 return true; 5264 } 5265 5266 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 5267 return ParsedType::make(Context.getDependentNameType(Kwd, NNS, Name)); 5268} 5269 5270TypeResult 5271Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5272 const CXXScopeSpec &SS, const IdentifierInfo &II, 5273 SourceLocation IdLoc) { 5274 NestedNameSpecifier *NNS 5275 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 5276 if (!NNS) 5277 return true; 5278 5279 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5280 !getLangOptions().CPlusPlus0x) 5281 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5282 << FixItHint::CreateRemoval(TypenameLoc); 5283 5284 QualType T = CheckTypenameType(ETK_Typename, NNS, II, 5285 TypenameLoc, SS.getRange(), IdLoc); 5286 if (T.isNull()) 5287 return true; 5288 5289 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5290 if (isa<DependentNameType>(T)) { 5291 DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc()); 5292 TL.setKeywordLoc(TypenameLoc); 5293 TL.setQualifierRange(SS.getRange()); 5294 TL.setNameLoc(IdLoc); 5295 } else { 5296 ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc()); 5297 TL.setKeywordLoc(TypenameLoc); 5298 TL.setQualifierRange(SS.getRange()); 5299 cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(IdLoc); 5300 } 5301 5302 return CreateParsedType(T, TSI); 5303} 5304 5305TypeResult 5306Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc, 5307 const CXXScopeSpec &SS, SourceLocation TemplateLoc, 5308 ParsedType Ty) { 5309 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent() && 5310 !getLangOptions().CPlusPlus0x) 5311 Diag(TypenameLoc, diag::ext_typename_outside_of_template) 5312 << FixItHint::CreateRemoval(TypenameLoc); 5313 5314 TypeSourceInfo *InnerTSI = 0; 5315 QualType T = GetTypeFromParser(Ty, &InnerTSI); 5316 5317 assert(isa<TemplateSpecializationType>(T) && 5318 "Expected a template specialization type"); 5319 5320 if (computeDeclContext(SS, false)) { 5321 // If we can compute a declaration context, then the "typename" 5322 // keyword was superfluous. Just build an ElaboratedType to keep 5323 // track of the nested-name-specifier. 5324 5325 // Push the inner type, preserving its source locations if possible. 5326 TypeLocBuilder Builder; 5327 if (InnerTSI) 5328 Builder.pushFullCopy(InnerTSI->getTypeLoc()); 5329 else 5330 Builder.push<TemplateSpecializationTypeLoc>(T).initialize(TemplateLoc); 5331 5332 /* Note: NNS already embedded in template specialization type T. */ 5333 T = Context.getElaboratedType(ETK_Typename, /*NNS=*/0, T); 5334 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T); 5335 TL.setKeywordLoc(TypenameLoc); 5336 TL.setQualifierRange(SS.getRange()); 5337 5338 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T); 5339 return CreateParsedType(T, TSI); 5340 } 5341 5342 // TODO: it's really silly that we make a template specialization 5343 // type earlier only to drop it again here. 5344 TemplateSpecializationType *TST = cast<TemplateSpecializationType>(T); 5345 DependentTemplateName *DTN = 5346 TST->getTemplateName().getAsDependentTemplateName(); 5347 assert(DTN && "dependent template has non-dependent name?"); 5348 assert(DTN->getQualifier() 5349 == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); 5350 T = Context.getDependentTemplateSpecializationType(ETK_Typename, 5351 DTN->getQualifier(), 5352 DTN->getIdentifier(), 5353 TST->getNumArgs(), 5354 TST->getArgs()); 5355 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 5356 DependentTemplateSpecializationTypeLoc TL = 5357 cast<DependentTemplateSpecializationTypeLoc>(TSI->getTypeLoc()); 5358 if (InnerTSI) { 5359 TemplateSpecializationTypeLoc TSTL = 5360 cast<TemplateSpecializationTypeLoc>(InnerTSI->getTypeLoc()); 5361 TL.setLAngleLoc(TSTL.getLAngleLoc()); 5362 TL.setRAngleLoc(TSTL.getRAngleLoc()); 5363 for (unsigned I = 0, E = TST->getNumArgs(); I != E; ++I) 5364 TL.setArgLocInfo(I, TSTL.getArgLocInfo(I)); 5365 } else { 5366 TL.initializeLocal(SourceLocation()); 5367 } 5368 TL.setKeywordLoc(TypenameLoc); 5369 TL.setQualifierRange(SS.getRange()); 5370 return CreateParsedType(T, TSI); 5371} 5372 5373/// \brief Build the type that describes a C++ typename specifier, 5374/// e.g., "typename T::type". 5375QualType 5376Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword, 5377 NestedNameSpecifier *NNS, const IdentifierInfo &II, 5378 SourceLocation KeywordLoc, SourceRange NNSRange, 5379 SourceLocation IILoc) { 5380 CXXScopeSpec SS; 5381 SS.setScopeRep(NNS); 5382 SS.setRange(NNSRange); 5383 5384 DeclContext *Ctx = computeDeclContext(SS); 5385 if (!Ctx) { 5386 // If the nested-name-specifier is dependent and couldn't be 5387 // resolved to a type, build a typename type. 5388 assert(NNS->isDependent()); 5389 return Context.getDependentNameType(Keyword, NNS, &II); 5390 } 5391 5392 // If the nested-name-specifier refers to the current instantiation, 5393 // the "typename" keyword itself is superfluous. In C++03, the 5394 // program is actually ill-formed. However, DR 382 (in C++0x CD1) 5395 // allows such extraneous "typename" keywords, and we retroactively 5396 // apply this DR to C++03 code with only a warning. In any case we continue. 5397 5398 if (RequireCompleteDeclContext(SS, Ctx)) 5399 return QualType(); 5400 5401 DeclarationName Name(&II); 5402 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName); 5403 LookupQualifiedName(Result, Ctx); 5404 unsigned DiagID = 0; 5405 Decl *Referenced = 0; 5406 switch (Result.getResultKind()) { 5407 case LookupResult::NotFound: 5408 DiagID = diag::err_typename_nested_not_found; 5409 break; 5410 5411 case LookupResult::NotFoundInCurrentInstantiation: 5412 // Okay, it's a member of an unknown instantiation. 5413 return Context.getDependentNameType(Keyword, NNS, &II); 5414 5415 case LookupResult::Found: 5416 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) { 5417 // We found a type. Build an ElaboratedType, since the 5418 // typename-specifier was just sugar. 5419 return Context.getElaboratedType(ETK_Typename, NNS, 5420 Context.getTypeDeclType(Type)); 5421 } 5422 5423 DiagID = diag::err_typename_nested_not_type; 5424 Referenced = Result.getFoundDecl(); 5425 break; 5426 5427 case LookupResult::FoundUnresolvedValue: 5428 llvm_unreachable("unresolved using decl in non-dependent context"); 5429 return QualType(); 5430 5431 case LookupResult::FoundOverloaded: 5432 DiagID = diag::err_typename_nested_not_type; 5433 Referenced = *Result.begin(); 5434 break; 5435 5436 case LookupResult::Ambiguous: 5437 return QualType(); 5438 } 5439 5440 // If we get here, it's because name lookup did not find a 5441 // type. Emit an appropriate diagnostic and return an error. 5442 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : NNSRange.getBegin(), 5443 IILoc); 5444 Diag(IILoc, DiagID) << FullRange << Name << Ctx; 5445 if (Referenced) 5446 Diag(Referenced->getLocation(), diag::note_typename_refers_here) 5447 << Name; 5448 return QualType(); 5449} 5450 5451namespace { 5452 // See Sema::RebuildTypeInCurrentInstantiation 5453 class CurrentInstantiationRebuilder 5454 : public TreeTransform<CurrentInstantiationRebuilder> { 5455 SourceLocation Loc; 5456 DeclarationName Entity; 5457 5458 public: 5459 typedef TreeTransform<CurrentInstantiationRebuilder> inherited; 5460 5461 CurrentInstantiationRebuilder(Sema &SemaRef, 5462 SourceLocation Loc, 5463 DeclarationName Entity) 5464 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef), 5465 Loc(Loc), Entity(Entity) { } 5466 5467 /// \brief Determine whether the given type \p T has already been 5468 /// transformed. 5469 /// 5470 /// For the purposes of type reconstruction, a type has already been 5471 /// transformed if it is NULL or if it is not dependent. 5472 bool AlreadyTransformed(QualType T) { 5473 return T.isNull() || !T->isDependentType(); 5474 } 5475 5476 /// \brief Returns the location of the entity whose type is being 5477 /// rebuilt. 5478 SourceLocation getBaseLocation() { return Loc; } 5479 5480 /// \brief Returns the name of the entity whose type is being rebuilt. 5481 DeclarationName getBaseEntity() { return Entity; } 5482 5483 /// \brief Sets the "base" location and entity when that 5484 /// information is known based on another transformation. 5485 void setBase(SourceLocation Loc, DeclarationName Entity) { 5486 this->Loc = Loc; 5487 this->Entity = Entity; 5488 } 5489 }; 5490} 5491 5492/// \brief Rebuilds a type within the context of the current instantiation. 5493/// 5494/// The type \p T is part of the type of an out-of-line member definition of 5495/// a class template (or class template partial specialization) that was parsed 5496/// and constructed before we entered the scope of the class template (or 5497/// partial specialization thereof). This routine will rebuild that type now 5498/// that we have entered the declarator's scope, which may produce different 5499/// canonical types, e.g., 5500/// 5501/// \code 5502/// template<typename T> 5503/// struct X { 5504/// typedef T* pointer; 5505/// pointer data(); 5506/// }; 5507/// 5508/// template<typename T> 5509/// typename X<T>::pointer X<T>::data() { ... } 5510/// \endcode 5511/// 5512/// Here, the type "typename X<T>::pointer" will be created as a DependentNameType, 5513/// since we do not know that we can look into X<T> when we parsed the type. 5514/// This function will rebuild the type, performing the lookup of "pointer" 5515/// in X<T> and returning an ElaboratedType whose canonical type is the same 5516/// as the canonical type of T*, allowing the return types of the out-of-line 5517/// definition and the declaration to match. 5518TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T, 5519 SourceLocation Loc, 5520 DeclarationName Name) { 5521 if (!T || !T->getType()->isDependentType()) 5522 return T; 5523 5524 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name); 5525 return Rebuilder.TransformType(T); 5526} 5527 5528ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) { 5529 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(), 5530 DeclarationName()); 5531 return Rebuilder.TransformExpr(E); 5532} 5533 5534bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) { 5535 if (SS.isInvalid()) return true; 5536 5537 NestedNameSpecifier *NNS = static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 5538 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(), 5539 DeclarationName()); 5540 NestedNameSpecifier *Rebuilt = 5541 Rebuilder.TransformNestedNameSpecifier(NNS, SS.getRange()); 5542 if (!Rebuilt) return true; 5543 5544 SS.setScopeRep(Rebuilt); 5545 return false; 5546} 5547 5548/// \brief Produces a formatted string that describes the binding of 5549/// template parameters to template arguments. 5550std::string 5551Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 5552 const TemplateArgumentList &Args) { 5553 // FIXME: For variadic templates, we'll need to get the structured list. 5554 return getTemplateArgumentBindingsText(Params, Args.getFlatArgumentList(), 5555 Args.flat_size()); 5556} 5557 5558std::string 5559Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 5560 const TemplateArgument *Args, 5561 unsigned NumArgs) { 5562 std::string Result; 5563 5564 if (!Params || Params->size() == 0 || NumArgs == 0) 5565 return Result; 5566 5567 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 5568 if (I >= NumArgs) 5569 break; 5570 5571 if (I == 0) 5572 Result += "[with "; 5573 else 5574 Result += ", "; 5575 5576 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) { 5577 Result += Id->getName(); 5578 } else { 5579 Result += '$'; 5580 Result += llvm::utostr(I); 5581 } 5582 5583 Result += " = "; 5584 5585 switch (Args[I].getKind()) { 5586 case TemplateArgument::Null: 5587 Result += "<no value>"; 5588 break; 5589 5590 case TemplateArgument::Type: { 5591 std::string TypeStr; 5592 Args[I].getAsType().getAsStringInternal(TypeStr, 5593 Context.PrintingPolicy); 5594 Result += TypeStr; 5595 break; 5596 } 5597 5598 case TemplateArgument::Declaration: { 5599 bool Unnamed = true; 5600 if (NamedDecl *ND = dyn_cast_or_null<NamedDecl>(Args[I].getAsDecl())) { 5601 if (ND->getDeclName()) { 5602 Unnamed = false; 5603 Result += ND->getNameAsString(); 5604 } 5605 } 5606 5607 if (Unnamed) { 5608 Result += "<anonymous>"; 5609 } 5610 break; 5611 } 5612 5613 case TemplateArgument::Template: { 5614 std::string Str; 5615 llvm::raw_string_ostream OS(Str); 5616 Args[I].getAsTemplate().print(OS, Context.PrintingPolicy); 5617 Result += OS.str(); 5618 break; 5619 } 5620 5621 case TemplateArgument::Integral: { 5622 Result += Args[I].getAsIntegral()->toString(10); 5623 break; 5624 } 5625 5626 case TemplateArgument::Expression: { 5627 // FIXME: This is non-optimal, since we're regurgitating the 5628 // expression we were given. 5629 std::string Str; 5630 { 5631 llvm::raw_string_ostream OS(Str); 5632 Args[I].getAsExpr()->printPretty(OS, Context, 0, 5633 Context.PrintingPolicy); 5634 } 5635 Result += Str; 5636 break; 5637 } 5638 5639 case TemplateArgument::Pack: 5640 // FIXME: Format template argument packs 5641 Result += "<template argument pack>"; 5642 break; 5643 } 5644 } 5645 5646 Result += ']'; 5647 return Result; 5648} 5649