SemaTemplate.cpp revision ff7bf10d1cb8274573589a41fd570396d7abb2ed
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 "Sema.h" 13#include "TreeTransform.h" 14#include "clang/AST/ASTContext.h" 15#include "clang/AST/Expr.h" 16#include "clang/AST/ExprCXX.h" 17#include "clang/AST/DeclTemplate.h" 18#include "clang/Parse/DeclSpec.h" 19#include "clang/Parse/Template.h" 20#include "clang/Basic/LangOptions.h" 21#include "clang/Basic/PartialDiagnostic.h" 22#include "llvm/Support/Compiler.h" 23#include "llvm/ADT/StringExtras.h" 24using namespace clang; 25 26/// \brief Determine whether the declaration found is acceptable as the name 27/// of a template and, if so, return that template declaration. Otherwise, 28/// returns NULL. 29static NamedDecl *isAcceptableTemplateName(ASTContext &Context, NamedDecl *D) { 30 if (!D) 31 return 0; 32 33 if (isa<TemplateDecl>(D)) 34 return D; 35 36 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) { 37 // C++ [temp.local]p1: 38 // Like normal (non-template) classes, class templates have an 39 // injected-class-name (Clause 9). The injected-class-name 40 // can be used with or without a template-argument-list. When 41 // it is used without a template-argument-list, it is 42 // equivalent to the injected-class-name followed by the 43 // template-parameters of the class template enclosed in 44 // <>. When it is used with a template-argument-list, it 45 // refers to the specified class template specialization, 46 // which could be the current specialization or another 47 // specialization. 48 if (Record->isInjectedClassName()) { 49 Record = cast<CXXRecordDecl>(Record->getDeclContext()); 50 if (Record->getDescribedClassTemplate()) 51 return Record->getDescribedClassTemplate(); 52 53 if (ClassTemplateSpecializationDecl *Spec 54 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) 55 return Spec->getSpecializedTemplate(); 56 } 57 58 return 0; 59 } 60 61 OverloadedFunctionDecl *Ovl = dyn_cast<OverloadedFunctionDecl>(D); 62 if (!Ovl) 63 return 0; 64 65 for (OverloadedFunctionDecl::function_iterator F = Ovl->function_begin(), 66 FEnd = Ovl->function_end(); 67 F != FEnd; ++F) { 68 if (FunctionTemplateDecl *FuncTmpl = dyn_cast<FunctionTemplateDecl>(*F)) { 69 // We've found a function template. Determine whether there are 70 // any other function templates we need to bundle together in an 71 // OverloadedFunctionDecl 72 for (++F; F != FEnd; ++F) { 73 if (isa<FunctionTemplateDecl>(*F)) 74 break; 75 } 76 77 if (F != FEnd) { 78 // Build an overloaded function decl containing only the 79 // function templates in Ovl. 80 OverloadedFunctionDecl *OvlTemplate 81 = OverloadedFunctionDecl::Create(Context, 82 Ovl->getDeclContext(), 83 Ovl->getDeclName()); 84 OvlTemplate->addOverload(FuncTmpl); 85 OvlTemplate->addOverload(*F); 86 for (++F; F != FEnd; ++F) { 87 if (isa<FunctionTemplateDecl>(*F)) 88 OvlTemplate->addOverload(*F); 89 } 90 91 return OvlTemplate; 92 } 93 94 return FuncTmpl; 95 } 96 } 97 98 return 0; 99} 100 101TemplateNameKind Sema::isTemplateName(Scope *S, 102 const CXXScopeSpec &SS, 103 UnqualifiedId &Name, 104 TypeTy *ObjectTypePtr, 105 bool EnteringContext, 106 TemplateTy &TemplateResult) { 107 DeclarationName TName; 108 109 switch (Name.getKind()) { 110 case UnqualifiedId::IK_Identifier: 111 TName = DeclarationName(Name.Identifier); 112 break; 113 114 case UnqualifiedId::IK_OperatorFunctionId: 115 TName = Context.DeclarationNames.getCXXOperatorName( 116 Name.OperatorFunctionId.Operator); 117 break; 118 119 default: 120 return TNK_Non_template; 121 } 122 123 // Determine where to perform name lookup 124 DeclContext *LookupCtx = 0; 125 bool isDependent = false; 126 if (ObjectTypePtr) { 127 // This nested-name-specifier occurs in a member access expression, e.g., 128 // x->B::f, and we are looking into the type of the object. 129 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 130 QualType ObjectType = QualType::getFromOpaquePtr(ObjectTypePtr); 131 LookupCtx = computeDeclContext(ObjectType); 132 isDependent = ObjectType->isDependentType(); 133 } else if (SS.isSet()) { 134 // This nested-name-specifier occurs after another nested-name-specifier, 135 // so long into the context associated with the prior nested-name-specifier. 136 137 LookupCtx = computeDeclContext(SS, EnteringContext); 138 isDependent = isDependentScopeSpecifier(SS); 139 } 140 141 LookupResult Found(*this, TName, SourceLocation(), LookupOrdinaryName); 142 bool ObjectTypeSearchedInScope = false; 143 if (LookupCtx) { 144 // Perform "qualified" name lookup into the declaration context we 145 // computed, which is either the type of the base of a member access 146 // expression or the declaration context associated with a prior 147 // nested-name-specifier. 148 149 // The declaration context must be complete. 150 if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(SS)) 151 return TNK_Non_template; 152 153 LookupQualifiedName(Found, LookupCtx); 154 155 if (ObjectTypePtr && Found.empty()) { 156 // C++ [basic.lookup.classref]p1: 157 // In a class member access expression (5.2.5), if the . or -> token is 158 // immediately followed by an identifier followed by a <, the 159 // identifier must be looked up to determine whether the < is the 160 // beginning of a template argument list (14.2) or a less-than operator. 161 // The identifier is first looked up in the class of the object 162 // expression. If the identifier is not found, it is then looked up in 163 // the context of the entire postfix-expression and shall name a class 164 // or function template. 165 // 166 // FIXME: When we're instantiating a template, do we actually have to 167 // look in the scope of the template? Seems fishy... 168 LookupName(Found, S); 169 ObjectTypeSearchedInScope = true; 170 } 171 } else if (isDependent) { 172 // We cannot look into a dependent object type or 173 return TNK_Non_template; 174 } else { 175 // Perform unqualified name lookup in the current scope. 176 LookupName(Found, S); 177 } 178 179 // FIXME: Cope with ambiguous name-lookup results. 180 assert(!Found.isAmbiguous() && 181 "Cannot handle template name-lookup ambiguities"); 182 183 NamedDecl *Template 184 = isAcceptableTemplateName(Context, Found.getAsSingleDecl(Context)); 185 if (!Template) 186 return TNK_Non_template; 187 188 if (ObjectTypePtr && !ObjectTypeSearchedInScope) { 189 // C++ [basic.lookup.classref]p1: 190 // [...] If the lookup in the class of the object expression finds a 191 // template, the name is also looked up in the context of the entire 192 // postfix-expression and [...] 193 // 194 LookupResult FoundOuter(*this, TName, SourceLocation(), LookupOrdinaryName); 195 LookupName(FoundOuter, S); 196 // FIXME: Handle ambiguities in this lookup better 197 NamedDecl *OuterTemplate 198 = isAcceptableTemplateName(Context, FoundOuter.getAsSingleDecl(Context)); 199 200 if (!OuterTemplate) { 201 // - if the name is not found, the name found in the class of the 202 // object expression is used, otherwise 203 } else if (!isa<ClassTemplateDecl>(OuterTemplate)) { 204 // - if the name is found in the context of the entire 205 // postfix-expression and does not name a class template, the name 206 // found in the class of the object expression is used, otherwise 207 } else { 208 // - if the name found is a class template, it must refer to the same 209 // entity as the one found in the class of the object expression, 210 // otherwise the program is ill-formed. 211 if (OuterTemplate->getCanonicalDecl() != Template->getCanonicalDecl()) { 212 Diag(Name.getSourceRange().getBegin(), 213 diag::err_nested_name_member_ref_lookup_ambiguous) 214 << TName 215 << Name.getSourceRange(); 216 Diag(Template->getLocation(), diag::note_ambig_member_ref_object_type) 217 << QualType::getFromOpaquePtr(ObjectTypePtr); 218 Diag(OuterTemplate->getLocation(), diag::note_ambig_member_ref_scope); 219 220 // Recover by taking the template that we found in the object 221 // expression's type. 222 } 223 } 224 } 225 226 if (SS.isSet() && !SS.isInvalid()) { 227 NestedNameSpecifier *Qualifier 228 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 229 if (OverloadedFunctionDecl *Ovl 230 = dyn_cast<OverloadedFunctionDecl>(Template)) 231 TemplateResult 232 = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, false, 233 Ovl)); 234 else 235 TemplateResult 236 = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, false, 237 cast<TemplateDecl>(Template))); 238 } else if (OverloadedFunctionDecl *Ovl 239 = dyn_cast<OverloadedFunctionDecl>(Template)) { 240 TemplateResult = TemplateTy::make(TemplateName(Ovl)); 241 } else { 242 TemplateResult = TemplateTy::make( 243 TemplateName(cast<TemplateDecl>(Template))); 244 } 245 246 if (isa<ClassTemplateDecl>(Template) || 247 isa<TemplateTemplateParmDecl>(Template)) 248 return TNK_Type_template; 249 250 assert((isa<FunctionTemplateDecl>(Template) || 251 isa<OverloadedFunctionDecl>(Template)) && 252 "Unhandled template kind in Sema::isTemplateName"); 253 return TNK_Function_template; 254} 255 256/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining 257/// that the template parameter 'PrevDecl' is being shadowed by a new 258/// declaration at location Loc. Returns true to indicate that this is 259/// an error, and false otherwise. 260bool Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { 261 assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); 262 263 // Microsoft Visual C++ permits template parameters to be shadowed. 264 if (getLangOptions().Microsoft) 265 return false; 266 267 // C++ [temp.local]p4: 268 // A template-parameter shall not be redeclared within its 269 // scope (including nested scopes). 270 Diag(Loc, diag::err_template_param_shadow) 271 << cast<NamedDecl>(PrevDecl)->getDeclName(); 272 Diag(PrevDecl->getLocation(), diag::note_template_param_here); 273 return true; 274} 275 276/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset 277/// the parameter D to reference the templated declaration and return a pointer 278/// to the template declaration. Otherwise, do nothing to D and return null. 279TemplateDecl *Sema::AdjustDeclIfTemplate(DeclPtrTy &D) { 280 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D.getAs<Decl>())) { 281 D = DeclPtrTy::make(Temp->getTemplatedDecl()); 282 return Temp; 283 } 284 return 0; 285} 286 287static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef, 288 const ParsedTemplateArgument &Arg) { 289 290 switch (Arg.getKind()) { 291 case ParsedTemplateArgument::Type: { 292 DeclaratorInfo *DI; 293 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI); 294 if (!DI) 295 DI = SemaRef.Context.getTrivialDeclaratorInfo(T, Arg.getLocation()); 296 return TemplateArgumentLoc(TemplateArgument(T), DI); 297 } 298 299 case ParsedTemplateArgument::NonType: { 300 Expr *E = static_cast<Expr *>(Arg.getAsExpr()); 301 return TemplateArgumentLoc(TemplateArgument(E), E); 302 } 303 304 case ParsedTemplateArgument::Template: { 305 TemplateName Template 306 = TemplateName::getFromVoidPointer(Arg.getAsTemplate().get()); 307 return TemplateArgumentLoc(TemplateArgument(Template), 308 Arg.getScopeSpec().getRange(), 309 Arg.getLocation()); 310 } 311 } 312 313 llvm::llvm_unreachable("Unhandled parsed template argument"); 314 return TemplateArgumentLoc(); 315} 316 317/// \brief Translates template arguments as provided by the parser 318/// into template arguments used by semantic analysis. 319void Sema::translateTemplateArguments(ASTTemplateArgsPtr &TemplateArgsIn, 320 llvm::SmallVectorImpl<TemplateArgumentLoc> &TemplateArgs) { 321 TemplateArgs.reserve(TemplateArgsIn.size()); 322 323 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I) 324 TemplateArgs.push_back(translateTemplateArgument(*this, TemplateArgsIn[I])); 325} 326 327/// ActOnTypeParameter - Called when a C++ template type parameter 328/// (e.g., "typename T") has been parsed. Typename specifies whether 329/// the keyword "typename" was used to declare the type parameter 330/// (otherwise, "class" was used), and KeyLoc is the location of the 331/// "class" or "typename" keyword. ParamName is the name of the 332/// parameter (NULL indicates an unnamed template parameter) and 333/// ParamName is the location of the parameter name (if any). 334/// If the type parameter has a default argument, it will be added 335/// later via ActOnTypeParameterDefault. 336Sema::DeclPtrTy Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis, 337 SourceLocation EllipsisLoc, 338 SourceLocation KeyLoc, 339 IdentifierInfo *ParamName, 340 SourceLocation ParamNameLoc, 341 unsigned Depth, unsigned Position) { 342 assert(S->isTemplateParamScope() && 343 "Template type parameter not in template parameter scope!"); 344 bool Invalid = false; 345 346 if (ParamName) { 347 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, LookupTagName); 348 if (PrevDecl && PrevDecl->isTemplateParameter()) 349 Invalid = Invalid || DiagnoseTemplateParameterShadow(ParamNameLoc, 350 PrevDecl); 351 } 352 353 SourceLocation Loc = ParamNameLoc; 354 if (!ParamName) 355 Loc = KeyLoc; 356 357 TemplateTypeParmDecl *Param 358 = TemplateTypeParmDecl::Create(Context, CurContext, Loc, 359 Depth, Position, ParamName, Typename, 360 Ellipsis); 361 if (Invalid) 362 Param->setInvalidDecl(); 363 364 if (ParamName) { 365 // Add the template parameter into the current scope. 366 S->AddDecl(DeclPtrTy::make(Param)); 367 IdResolver.AddDecl(Param); 368 } 369 370 return DeclPtrTy::make(Param); 371} 372 373/// ActOnTypeParameterDefault - Adds a default argument (the type 374/// Default) to the given template type parameter (TypeParam). 375void Sema::ActOnTypeParameterDefault(DeclPtrTy TypeParam, 376 SourceLocation EqualLoc, 377 SourceLocation DefaultLoc, 378 TypeTy *DefaultT) { 379 TemplateTypeParmDecl *Parm 380 = cast<TemplateTypeParmDecl>(TypeParam.getAs<Decl>()); 381 382 DeclaratorInfo *DefaultDInfo; 383 GetTypeFromParser(DefaultT, &DefaultDInfo); 384 385 assert(DefaultDInfo && "expected source information for type"); 386 387 // C++0x [temp.param]p9: 388 // A default template-argument may be specified for any kind of 389 // template-parameter that is not a template parameter pack. 390 if (Parm->isParameterPack()) { 391 Diag(DefaultLoc, diag::err_template_param_pack_default_arg); 392 return; 393 } 394 395 // C++ [temp.param]p14: 396 // A template-parameter shall not be used in its own default argument. 397 // FIXME: Implement this check! Needs a recursive walk over the types. 398 399 // Check the template argument itself. 400 if (CheckTemplateArgument(Parm, DefaultDInfo)) { 401 Parm->setInvalidDecl(); 402 return; 403 } 404 405 Parm->setDefaultArgument(DefaultDInfo, false); 406} 407 408/// \brief Check that the type of a non-type template parameter is 409/// well-formed. 410/// 411/// \returns the (possibly-promoted) parameter type if valid; 412/// otherwise, produces a diagnostic and returns a NULL type. 413QualType 414Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) { 415 // C++ [temp.param]p4: 416 // 417 // A non-type template-parameter shall have one of the following 418 // (optionally cv-qualified) types: 419 // 420 // -- integral or enumeration type, 421 if (T->isIntegralType() || T->isEnumeralType() || 422 // -- pointer to object or pointer to function, 423 (T->isPointerType() && 424 (T->getAs<PointerType>()->getPointeeType()->isObjectType() || 425 T->getAs<PointerType>()->getPointeeType()->isFunctionType())) || 426 // -- reference to object or reference to function, 427 T->isReferenceType() || 428 // -- pointer to member. 429 T->isMemberPointerType() || 430 // If T is a dependent type, we can't do the check now, so we 431 // assume that it is well-formed. 432 T->isDependentType()) 433 return T; 434 // C++ [temp.param]p8: 435 // 436 // A non-type template-parameter of type "array of T" or 437 // "function returning T" is adjusted to be of type "pointer to 438 // T" or "pointer to function returning T", respectively. 439 else if (T->isArrayType()) 440 // FIXME: Keep the type prior to promotion? 441 return Context.getArrayDecayedType(T); 442 else if (T->isFunctionType()) 443 // FIXME: Keep the type prior to promotion? 444 return Context.getPointerType(T); 445 446 Diag(Loc, diag::err_template_nontype_parm_bad_type) 447 << T; 448 449 return QualType(); 450} 451 452/// ActOnNonTypeTemplateParameter - Called when a C++ non-type 453/// template parameter (e.g., "int Size" in "template<int Size> 454/// class Array") has been parsed. S is the current scope and D is 455/// the parsed declarator. 456Sema::DeclPtrTy Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D, 457 unsigned Depth, 458 unsigned Position) { 459 DeclaratorInfo *DInfo = 0; 460 QualType T = GetTypeForDeclarator(D, S, &DInfo); 461 462 assert(S->isTemplateParamScope() && 463 "Non-type template parameter not in template parameter scope!"); 464 bool Invalid = false; 465 466 IdentifierInfo *ParamName = D.getIdentifier(); 467 if (ParamName) { 468 NamedDecl *PrevDecl = LookupSingleName(S, ParamName, LookupTagName); 469 if (PrevDecl && PrevDecl->isTemplateParameter()) 470 Invalid = Invalid || DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), 471 PrevDecl); 472 } 473 474 T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc()); 475 if (T.isNull()) { 476 T = Context.IntTy; // Recover with an 'int' type. 477 Invalid = true; 478 } 479 480 NonTypeTemplateParmDecl *Param 481 = NonTypeTemplateParmDecl::Create(Context, CurContext, D.getIdentifierLoc(), 482 Depth, Position, ParamName, T, DInfo); 483 if (Invalid) 484 Param->setInvalidDecl(); 485 486 if (D.getIdentifier()) { 487 // Add the template parameter into the current scope. 488 S->AddDecl(DeclPtrTy::make(Param)); 489 IdResolver.AddDecl(Param); 490 } 491 return DeclPtrTy::make(Param); 492} 493 494/// \brief Adds a default argument to the given non-type template 495/// parameter. 496void Sema::ActOnNonTypeTemplateParameterDefault(DeclPtrTy TemplateParamD, 497 SourceLocation EqualLoc, 498 ExprArg DefaultE) { 499 NonTypeTemplateParmDecl *TemplateParm 500 = cast<NonTypeTemplateParmDecl>(TemplateParamD.getAs<Decl>()); 501 Expr *Default = static_cast<Expr *>(DefaultE.get()); 502 503 // C++ [temp.param]p14: 504 // A template-parameter shall not be used in its own default argument. 505 // FIXME: Implement this check! Needs a recursive walk over the types. 506 507 // Check the well-formedness of the default template argument. 508 TemplateArgument Converted; 509 if (CheckTemplateArgument(TemplateParm, TemplateParm->getType(), Default, 510 Converted)) { 511 TemplateParm->setInvalidDecl(); 512 return; 513 } 514 515 TemplateParm->setDefaultArgument(DefaultE.takeAs<Expr>()); 516} 517 518 519/// ActOnTemplateTemplateParameter - Called when a C++ template template 520/// parameter (e.g. T in template <template <typename> class T> class array) 521/// has been parsed. S is the current scope. 522Sema::DeclPtrTy Sema::ActOnTemplateTemplateParameter(Scope* S, 523 SourceLocation TmpLoc, 524 TemplateParamsTy *Params, 525 IdentifierInfo *Name, 526 SourceLocation NameLoc, 527 unsigned Depth, 528 unsigned Position) { 529 assert(S->isTemplateParamScope() && 530 "Template template parameter not in template parameter scope!"); 531 532 // Construct the parameter object. 533 TemplateTemplateParmDecl *Param = 534 TemplateTemplateParmDecl::Create(Context, CurContext, TmpLoc, Depth, 535 Position, Name, 536 (TemplateParameterList*)Params); 537 538 // Make sure the parameter is valid. 539 // FIXME: Decl object is not currently invalidated anywhere so this doesn't 540 // do anything yet. However, if the template parameter list or (eventual) 541 // default value is ever invalidated, that will propagate here. 542 bool Invalid = false; 543 if (Invalid) { 544 Param->setInvalidDecl(); 545 } 546 547 // If the tt-param has a name, then link the identifier into the scope 548 // and lookup mechanisms. 549 if (Name) { 550 S->AddDecl(DeclPtrTy::make(Param)); 551 IdResolver.AddDecl(Param); 552 } 553 554 return DeclPtrTy::make(Param); 555} 556 557/// \brief Adds a default argument to the given template template 558/// parameter. 559void Sema::ActOnTemplateTemplateParameterDefault(DeclPtrTy TemplateParamD, 560 SourceLocation EqualLoc, 561 const ParsedTemplateArgument &Default) { 562 TemplateTemplateParmDecl *TemplateParm 563 = cast<TemplateTemplateParmDecl>(TemplateParamD.getAs<Decl>()); 564 565 // C++ [temp.param]p14: 566 // A template-parameter shall not be used in its own default argument. 567 // FIXME: Implement this check! Needs a recursive walk over the types. 568 569 // Check only that we have a template template argument. We don't want to 570 // try to check well-formedness now, because our template template parameter 571 // might have dependent types in its template parameters, which we wouldn't 572 // be able to match now. 573 // 574 // If none of the template template parameter's template arguments mention 575 // other template parameters, we could actually perform more checking here. 576 // However, it isn't worth doing. 577 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default); 578 if (DefaultArg.getArgument().getAsTemplate().isNull()) { 579 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template) 580 << DefaultArg.getSourceRange(); 581 return; 582 } 583 584 TemplateParm->setDefaultArgument(DefaultArg); 585} 586 587/// ActOnTemplateParameterList - Builds a TemplateParameterList that 588/// contains the template parameters in Params/NumParams. 589Sema::TemplateParamsTy * 590Sema::ActOnTemplateParameterList(unsigned Depth, 591 SourceLocation ExportLoc, 592 SourceLocation TemplateLoc, 593 SourceLocation LAngleLoc, 594 DeclPtrTy *Params, unsigned NumParams, 595 SourceLocation RAngleLoc) { 596 if (ExportLoc.isValid()) 597 Diag(ExportLoc, diag::note_template_export_unsupported); 598 599 return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc, 600 (NamedDecl**)Params, NumParams, 601 RAngleLoc); 602} 603 604Sema::DeclResult 605Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK, 606 SourceLocation KWLoc, const CXXScopeSpec &SS, 607 IdentifierInfo *Name, SourceLocation NameLoc, 608 AttributeList *Attr, 609 TemplateParameterList *TemplateParams, 610 AccessSpecifier AS) { 611 assert(TemplateParams && TemplateParams->size() > 0 && 612 "No template parameters"); 613 assert(TUK != TUK_Reference && "Can only declare or define class templates"); 614 bool Invalid = false; 615 616 // Check that we can declare a template here. 617 if (CheckTemplateDeclScope(S, TemplateParams)) 618 return true; 619 620 TagDecl::TagKind Kind = TagDecl::getTagKindForTypeSpec(TagSpec); 621 assert(Kind != TagDecl::TK_enum && "can't build template of enumerated type"); 622 623 // There is no such thing as an unnamed class template. 624 if (!Name) { 625 Diag(KWLoc, diag::err_template_unnamed_class); 626 return true; 627 } 628 629 // Find any previous declaration with this name. 630 DeclContext *SemanticContext; 631 LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName, 632 LookupResult::ForRedeclaration); 633 if (SS.isNotEmpty() && !SS.isInvalid()) { 634 if (RequireCompleteDeclContext(SS)) 635 return true; 636 637 SemanticContext = computeDeclContext(SS, true); 638 if (!SemanticContext) { 639 // FIXME: Produce a reasonable diagnostic here 640 return true; 641 } 642 643 LookupQualifiedName(Previous, SemanticContext); 644 } else { 645 SemanticContext = CurContext; 646 LookupName(Previous, S); 647 } 648 649 assert(!Previous.isAmbiguous() && "Ambiguity in class template redecl?"); 650 NamedDecl *PrevDecl = 0; 651 if (Previous.begin() != Previous.end()) 652 PrevDecl = *Previous.begin(); 653 654 if (PrevDecl && TUK == TUK_Friend) { 655 // C++ [namespace.memdef]p3: 656 // [...] When looking for a prior declaration of a class or a function 657 // declared as a friend, and when the name of the friend class or 658 // function is neither a qualified name nor a template-id, scopes outside 659 // the innermost enclosing namespace scope are not considered. 660 DeclContext *OutermostContext = CurContext; 661 while (!OutermostContext->isFileContext()) 662 OutermostContext = OutermostContext->getLookupParent(); 663 664 if (OutermostContext->Equals(PrevDecl->getDeclContext()) || 665 OutermostContext->Encloses(PrevDecl->getDeclContext())) { 666 SemanticContext = PrevDecl->getDeclContext(); 667 } else { 668 // Declarations in outer scopes don't matter. However, the outermost 669 // context we computed is the semantic context for our new 670 // declaration. 671 PrevDecl = 0; 672 SemanticContext = OutermostContext; 673 } 674 675 if (CurContext->isDependentContext()) { 676 // If this is a dependent context, we don't want to link the friend 677 // class template to the template in scope, because that would perform 678 // checking of the template parameter lists that can't be performed 679 // until the outer context is instantiated. 680 PrevDecl = 0; 681 } 682 } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S)) 683 PrevDecl = 0; 684 685 // If there is a previous declaration with the same name, check 686 // whether this is a valid redeclaration. 687 ClassTemplateDecl *PrevClassTemplate 688 = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl); 689 690 // We may have found the injected-class-name of a class template, 691 // class template partial specialization, or class template specialization. 692 // In these cases, grab the template that is being defined or specialized. 693 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) && 694 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) { 695 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext()); 696 PrevClassTemplate 697 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate(); 698 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) { 699 PrevClassTemplate 700 = cast<ClassTemplateSpecializationDecl>(PrevDecl) 701 ->getSpecializedTemplate(); 702 } 703 } 704 705 if (PrevClassTemplate) { 706 // Ensure that the template parameter lists are compatible. 707 if (!TemplateParameterListsAreEqual(TemplateParams, 708 PrevClassTemplate->getTemplateParameters(), 709 /*Complain=*/true, 710 TPL_TemplateMatch)) 711 return true; 712 713 // C++ [temp.class]p4: 714 // In a redeclaration, partial specialization, explicit 715 // specialization or explicit instantiation of a class template, 716 // the class-key shall agree in kind with the original class 717 // template declaration (7.1.5.3). 718 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl(); 719 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, KWLoc, *Name)) { 720 Diag(KWLoc, diag::err_use_with_wrong_tag) 721 << Name 722 << CodeModificationHint::CreateReplacement(KWLoc, 723 PrevRecordDecl->getKindName()); 724 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use); 725 Kind = PrevRecordDecl->getTagKind(); 726 } 727 728 // Check for redefinition of this class template. 729 if (TUK == TUK_Definition) { 730 if (TagDecl *Def = PrevRecordDecl->getDefinition(Context)) { 731 Diag(NameLoc, diag::err_redefinition) << Name; 732 Diag(Def->getLocation(), diag::note_previous_definition); 733 // FIXME: Would it make sense to try to "forget" the previous 734 // definition, as part of error recovery? 735 return true; 736 } 737 } 738 } else if (PrevDecl && PrevDecl->isTemplateParameter()) { 739 // Maybe we will complain about the shadowed template parameter. 740 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); 741 // Just pretend that we didn't see the previous declaration. 742 PrevDecl = 0; 743 } else if (PrevDecl) { 744 // C++ [temp]p5: 745 // A class template shall not have the same name as any other 746 // template, class, function, object, enumeration, enumerator, 747 // namespace, or type in the same scope (3.3), except as specified 748 // in (14.5.4). 749 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 750 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 751 return true; 752 } 753 754 // Check the template parameter list of this declaration, possibly 755 // merging in the template parameter list from the previous class 756 // template declaration. 757 if (CheckTemplateParameterList(TemplateParams, 758 PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0)) 759 Invalid = true; 760 761 // FIXME: If we had a scope specifier, we better have a previous template 762 // declaration! 763 764 CXXRecordDecl *NewClass = 765 CXXRecordDecl::Create(Context, Kind, SemanticContext, NameLoc, Name, KWLoc, 766 PrevClassTemplate? 767 PrevClassTemplate->getTemplatedDecl() : 0, 768 /*DelayTypeCreation=*/true); 769 770 ClassTemplateDecl *NewTemplate 771 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc, 772 DeclarationName(Name), TemplateParams, 773 NewClass, PrevClassTemplate); 774 NewClass->setDescribedClassTemplate(NewTemplate); 775 776 // Build the type for the class template declaration now. 777 QualType T = 778 Context.getTypeDeclType(NewClass, 779 PrevClassTemplate? 780 PrevClassTemplate->getTemplatedDecl() : 0); 781 assert(T->isDependentType() && "Class template type is not dependent?"); 782 (void)T; 783 784 // If we are providing an explicit specialization of a member that is a 785 // class template, make a note of that. 786 if (PrevClassTemplate && 787 PrevClassTemplate->getInstantiatedFromMemberTemplate()) 788 PrevClassTemplate->setMemberSpecialization(); 789 790 // Set the access specifier. 791 if (!Invalid && TUK != TUK_Friend) 792 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS); 793 794 // Set the lexical context of these templates 795 NewClass->setLexicalDeclContext(CurContext); 796 NewTemplate->setLexicalDeclContext(CurContext); 797 798 if (TUK == TUK_Definition) 799 NewClass->startDefinition(); 800 801 if (Attr) 802 ProcessDeclAttributeList(S, NewClass, Attr); 803 804 if (TUK != TUK_Friend) 805 PushOnScopeChains(NewTemplate, S); 806 else { 807 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) { 808 NewTemplate->setAccess(PrevClassTemplate->getAccess()); 809 NewClass->setAccess(PrevClassTemplate->getAccess()); 810 } 811 812 NewTemplate->setObjectOfFriendDecl(/* PreviouslyDeclared = */ 813 PrevClassTemplate != NULL); 814 815 // Friend templates are visible in fairly strange ways. 816 if (!CurContext->isDependentContext()) { 817 DeclContext *DC = SemanticContext->getLookupContext(); 818 DC->makeDeclVisibleInContext(NewTemplate, /* Recoverable = */ false); 819 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 820 PushOnScopeChains(NewTemplate, EnclosingScope, 821 /* AddToContext = */ false); 822 } 823 824 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 825 NewClass->getLocation(), 826 NewTemplate, 827 /*FIXME:*/NewClass->getLocation()); 828 Friend->setAccess(AS_public); 829 CurContext->addDecl(Friend); 830 } 831 832 if (Invalid) { 833 NewTemplate->setInvalidDecl(); 834 NewClass->setInvalidDecl(); 835 } 836 return DeclPtrTy::make(NewTemplate); 837} 838 839/// \brief Checks the validity of a template parameter list, possibly 840/// considering the template parameter list from a previous 841/// declaration. 842/// 843/// If an "old" template parameter list is provided, it must be 844/// equivalent (per TemplateParameterListsAreEqual) to the "new" 845/// template parameter list. 846/// 847/// \param NewParams Template parameter list for a new template 848/// declaration. This template parameter list will be updated with any 849/// default arguments that are carried through from the previous 850/// template parameter list. 851/// 852/// \param OldParams If provided, template parameter list from a 853/// previous declaration of the same template. Default template 854/// arguments will be merged from the old template parameter list to 855/// the new template parameter list. 856/// 857/// \returns true if an error occurred, false otherwise. 858bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams, 859 TemplateParameterList *OldParams) { 860 bool Invalid = false; 861 862 // C++ [temp.param]p10: 863 // The set of default template-arguments available for use with a 864 // template declaration or definition is obtained by merging the 865 // default arguments from the definition (if in scope) and all 866 // declarations in scope in the same way default function 867 // arguments are (8.3.6). 868 bool SawDefaultArgument = false; 869 SourceLocation PreviousDefaultArgLoc; 870 871 bool SawParameterPack = false; 872 SourceLocation ParameterPackLoc; 873 874 // Dummy initialization to avoid warnings. 875 TemplateParameterList::iterator OldParam = NewParams->end(); 876 if (OldParams) 877 OldParam = OldParams->begin(); 878 879 for (TemplateParameterList::iterator NewParam = NewParams->begin(), 880 NewParamEnd = NewParams->end(); 881 NewParam != NewParamEnd; ++NewParam) { 882 // Variables used to diagnose redundant default arguments 883 bool RedundantDefaultArg = false; 884 SourceLocation OldDefaultLoc; 885 SourceLocation NewDefaultLoc; 886 887 // Variables used to diagnose missing default arguments 888 bool MissingDefaultArg = false; 889 890 // C++0x [temp.param]p11: 891 // If a template parameter of a class template is a template parameter pack, 892 // it must be the last template parameter. 893 if (SawParameterPack) { 894 Diag(ParameterPackLoc, 895 diag::err_template_param_pack_must_be_last_template_parameter); 896 Invalid = true; 897 } 898 899 // Merge default arguments for template type parameters. 900 if (TemplateTypeParmDecl *NewTypeParm 901 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) { 902 TemplateTypeParmDecl *OldTypeParm 903 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : 0; 904 905 if (NewTypeParm->isParameterPack()) { 906 assert(!NewTypeParm->hasDefaultArgument() && 907 "Parameter packs can't have a default argument!"); 908 SawParameterPack = true; 909 ParameterPackLoc = NewTypeParm->getLocation(); 910 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() && 911 NewTypeParm->hasDefaultArgument()) { 912 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc(); 913 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc(); 914 SawDefaultArgument = true; 915 RedundantDefaultArg = true; 916 PreviousDefaultArgLoc = NewDefaultLoc; 917 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) { 918 // Merge the default argument from the old declaration to the 919 // new declaration. 920 SawDefaultArgument = true; 921 NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(), 922 true); 923 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc(); 924 } else if (NewTypeParm->hasDefaultArgument()) { 925 SawDefaultArgument = true; 926 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc(); 927 } else if (SawDefaultArgument) 928 MissingDefaultArg = true; 929 } else if (NonTypeTemplateParmDecl *NewNonTypeParm 930 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) { 931 // Merge default arguments for non-type template parameters 932 NonTypeTemplateParmDecl *OldNonTypeParm 933 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : 0; 934 if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() && 935 NewNonTypeParm->hasDefaultArgument()) { 936 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc(); 937 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc(); 938 SawDefaultArgument = true; 939 RedundantDefaultArg = true; 940 PreviousDefaultArgLoc = NewDefaultLoc; 941 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) { 942 // Merge the default argument from the old declaration to the 943 // new declaration. 944 SawDefaultArgument = true; 945 // FIXME: We need to create a new kind of "default argument" 946 // expression that points to a previous template template 947 // parameter. 948 NewNonTypeParm->setDefaultArgument( 949 OldNonTypeParm->getDefaultArgument()); 950 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc(); 951 } else if (NewNonTypeParm->hasDefaultArgument()) { 952 SawDefaultArgument = true; 953 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc(); 954 } else if (SawDefaultArgument) 955 MissingDefaultArg = true; 956 } else { 957 // Merge default arguments for template template parameters 958 TemplateTemplateParmDecl *NewTemplateParm 959 = cast<TemplateTemplateParmDecl>(*NewParam); 960 TemplateTemplateParmDecl *OldTemplateParm 961 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : 0; 962 if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() && 963 NewTemplateParm->hasDefaultArgument()) { 964 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation(); 965 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation(); 966 SawDefaultArgument = true; 967 RedundantDefaultArg = true; 968 PreviousDefaultArgLoc = NewDefaultLoc; 969 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) { 970 // Merge the default argument from the old declaration to the 971 // new declaration. 972 SawDefaultArgument = true; 973 // FIXME: We need to create a new kind of "default argument" expression 974 // that points to a previous template template parameter. 975 NewTemplateParm->setDefaultArgument( 976 OldTemplateParm->getDefaultArgument()); 977 PreviousDefaultArgLoc 978 = OldTemplateParm->getDefaultArgument().getLocation(); 979 } else if (NewTemplateParm->hasDefaultArgument()) { 980 SawDefaultArgument = true; 981 PreviousDefaultArgLoc 982 = NewTemplateParm->getDefaultArgument().getLocation(); 983 } else if (SawDefaultArgument) 984 MissingDefaultArg = true; 985 } 986 987 if (RedundantDefaultArg) { 988 // C++ [temp.param]p12: 989 // A template-parameter shall not be given default arguments 990 // by two different declarations in the same scope. 991 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition); 992 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg); 993 Invalid = true; 994 } else if (MissingDefaultArg) { 995 // C++ [temp.param]p11: 996 // If a template-parameter has a default template-argument, 997 // all subsequent template-parameters shall have a default 998 // template-argument supplied. 999 Diag((*NewParam)->getLocation(), 1000 diag::err_template_param_default_arg_missing); 1001 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg); 1002 Invalid = true; 1003 } 1004 1005 // If we have an old template parameter list that we're merging 1006 // in, move on to the next parameter. 1007 if (OldParams) 1008 ++OldParam; 1009 } 1010 1011 return Invalid; 1012} 1013 1014/// \brief Match the given template parameter lists to the given scope 1015/// specifier, returning the template parameter list that applies to the 1016/// name. 1017/// 1018/// \param DeclStartLoc the start of the declaration that has a scope 1019/// specifier or a template parameter list. 1020/// 1021/// \param SS the scope specifier that will be matched to the given template 1022/// parameter lists. This scope specifier precedes a qualified name that is 1023/// being declared. 1024/// 1025/// \param ParamLists the template parameter lists, from the outermost to the 1026/// innermost template parameter lists. 1027/// 1028/// \param NumParamLists the number of template parameter lists in ParamLists. 1029/// 1030/// \param IsExplicitSpecialization will be set true if the entity being 1031/// declared is an explicit specialization, false otherwise. 1032/// 1033/// \returns the template parameter list, if any, that corresponds to the 1034/// name that is preceded by the scope specifier @p SS. This template 1035/// parameter list may be have template parameters (if we're declaring a 1036/// template) or may have no template parameters (if we're declaring a 1037/// template specialization), or may be NULL (if we were's declaring isn't 1038/// itself a template). 1039TemplateParameterList * 1040Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc, 1041 const CXXScopeSpec &SS, 1042 TemplateParameterList **ParamLists, 1043 unsigned NumParamLists, 1044 bool &IsExplicitSpecialization) { 1045 IsExplicitSpecialization = false; 1046 1047 // Find the template-ids that occur within the nested-name-specifier. These 1048 // template-ids will match up with the template parameter lists. 1049 llvm::SmallVector<const TemplateSpecializationType *, 4> 1050 TemplateIdsInSpecifier; 1051 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 1052 NNS; NNS = NNS->getPrefix()) { 1053 if (const TemplateSpecializationType *SpecType 1054 = dyn_cast_or_null<TemplateSpecializationType>(NNS->getAsType())) { 1055 TemplateDecl *Template = SpecType->getTemplateName().getAsTemplateDecl(); 1056 if (!Template) 1057 continue; // FIXME: should this be an error? probably... 1058 1059 if (const RecordType *Record = SpecType->getAs<RecordType>()) { 1060 ClassTemplateSpecializationDecl *SpecDecl 1061 = cast<ClassTemplateSpecializationDecl>(Record->getDecl()); 1062 // If the nested name specifier refers to an explicit specialization, 1063 // we don't need a template<> header. 1064 // FIXME: revisit this approach once we cope with specializations 1065 // properly. 1066 if (SpecDecl->getSpecializationKind() == TSK_ExplicitSpecialization) 1067 continue; 1068 } 1069 1070 TemplateIdsInSpecifier.push_back(SpecType); 1071 } 1072 } 1073 1074 // Reverse the list of template-ids in the scope specifier, so that we can 1075 // more easily match up the template-ids and the template parameter lists. 1076 std::reverse(TemplateIdsInSpecifier.begin(), TemplateIdsInSpecifier.end()); 1077 1078 SourceLocation FirstTemplateLoc = DeclStartLoc; 1079 if (NumParamLists) 1080 FirstTemplateLoc = ParamLists[0]->getTemplateLoc(); 1081 1082 // Match the template-ids found in the specifier to the template parameter 1083 // lists. 1084 unsigned Idx = 0; 1085 for (unsigned NumTemplateIds = TemplateIdsInSpecifier.size(); 1086 Idx != NumTemplateIds; ++Idx) { 1087 QualType TemplateId = QualType(TemplateIdsInSpecifier[Idx], 0); 1088 bool DependentTemplateId = TemplateId->isDependentType(); 1089 if (Idx >= NumParamLists) { 1090 // We have a template-id without a corresponding template parameter 1091 // list. 1092 if (DependentTemplateId) { 1093 // FIXME: the location information here isn't great. 1094 Diag(SS.getRange().getBegin(), 1095 diag::err_template_spec_needs_template_parameters) 1096 << TemplateId 1097 << SS.getRange(); 1098 } else { 1099 Diag(SS.getRange().getBegin(), diag::err_template_spec_needs_header) 1100 << SS.getRange() 1101 << CodeModificationHint::CreateInsertion(FirstTemplateLoc, 1102 "template<> "); 1103 IsExplicitSpecialization = true; 1104 } 1105 return 0; 1106 } 1107 1108 // Check the template parameter list against its corresponding template-id. 1109 if (DependentTemplateId) { 1110 TemplateDecl *Template 1111 = TemplateIdsInSpecifier[Idx]->getTemplateName().getAsTemplateDecl(); 1112 1113 if (ClassTemplateDecl *ClassTemplate 1114 = dyn_cast<ClassTemplateDecl>(Template)) { 1115 TemplateParameterList *ExpectedTemplateParams = 0; 1116 // Is this template-id naming the primary template? 1117 if (Context.hasSameType(TemplateId, 1118 ClassTemplate->getInjectedClassNameType(Context))) 1119 ExpectedTemplateParams = ClassTemplate->getTemplateParameters(); 1120 // ... or a partial specialization? 1121 else if (ClassTemplatePartialSpecializationDecl *PartialSpec 1122 = ClassTemplate->findPartialSpecialization(TemplateId)) 1123 ExpectedTemplateParams = PartialSpec->getTemplateParameters(); 1124 1125 if (ExpectedTemplateParams) 1126 TemplateParameterListsAreEqual(ParamLists[Idx], 1127 ExpectedTemplateParams, 1128 true, TPL_TemplateMatch); 1129 } 1130 } else if (ParamLists[Idx]->size() > 0) 1131 Diag(ParamLists[Idx]->getTemplateLoc(), 1132 diag::err_template_param_list_matches_nontemplate) 1133 << TemplateId 1134 << ParamLists[Idx]->getSourceRange(); 1135 else 1136 IsExplicitSpecialization = true; 1137 } 1138 1139 // If there were at least as many template-ids as there were template 1140 // parameter lists, then there are no template parameter lists remaining for 1141 // the declaration itself. 1142 if (Idx >= NumParamLists) 1143 return 0; 1144 1145 // If there were too many template parameter lists, complain about that now. 1146 if (Idx != NumParamLists - 1) { 1147 while (Idx < NumParamLists - 1) { 1148 Diag(ParamLists[Idx]->getTemplateLoc(), 1149 diag::err_template_spec_extra_headers) 1150 << SourceRange(ParamLists[Idx]->getTemplateLoc(), 1151 ParamLists[Idx]->getRAngleLoc()); 1152 ++Idx; 1153 } 1154 } 1155 1156 // Return the last template parameter list, which corresponds to the 1157 // entity being declared. 1158 return ParamLists[NumParamLists - 1]; 1159} 1160 1161QualType Sema::CheckTemplateIdType(TemplateName Name, 1162 SourceLocation TemplateLoc, 1163 SourceLocation LAngleLoc, 1164 const TemplateArgumentLoc *TemplateArgs, 1165 unsigned NumTemplateArgs, 1166 SourceLocation RAngleLoc) { 1167 TemplateDecl *Template = Name.getAsTemplateDecl(); 1168 if (!Template) { 1169 // The template name does not resolve to a template, so we just 1170 // build a dependent template-id type. 1171 return Context.getTemplateSpecializationType(Name, TemplateArgs, 1172 NumTemplateArgs); 1173 } 1174 1175 // Check that the template argument list is well-formed for this 1176 // template. 1177 TemplateArgumentListBuilder Converted(Template->getTemplateParameters(), 1178 NumTemplateArgs); 1179 if (CheckTemplateArgumentList(Template, TemplateLoc, LAngleLoc, 1180 TemplateArgs, NumTemplateArgs, RAngleLoc, 1181 false, Converted)) 1182 return QualType(); 1183 1184 assert((Converted.structuredSize() == 1185 Template->getTemplateParameters()->size()) && 1186 "Converted template argument list is too short!"); 1187 1188 QualType CanonType; 1189 1190 if (Name.isDependent() || 1191 TemplateSpecializationType::anyDependentTemplateArguments( 1192 TemplateArgs, 1193 NumTemplateArgs)) { 1194 // This class template specialization is a dependent 1195 // type. Therefore, its canonical type is another class template 1196 // specialization type that contains all of the converted 1197 // arguments in canonical form. This ensures that, e.g., A<T> and 1198 // A<T, T> have identical types when A is declared as: 1199 // 1200 // template<typename T, typename U = T> struct A; 1201 TemplateName CanonName = Context.getCanonicalTemplateName(Name); 1202 CanonType = Context.getTemplateSpecializationType(CanonName, 1203 Converted.getFlatArguments(), 1204 Converted.flatSize()); 1205 1206 // FIXME: CanonType is not actually the canonical type, and unfortunately 1207 // it is a TemplateSpecializationType that we will never use again. 1208 // In the future, we need to teach getTemplateSpecializationType to only 1209 // build the canonical type and return that to us. 1210 CanonType = Context.getCanonicalType(CanonType); 1211 } else if (ClassTemplateDecl *ClassTemplate 1212 = dyn_cast<ClassTemplateDecl>(Template)) { 1213 // Find the class template specialization declaration that 1214 // corresponds to these arguments. 1215 llvm::FoldingSetNodeID ID; 1216 ClassTemplateSpecializationDecl::Profile(ID, 1217 Converted.getFlatArguments(), 1218 Converted.flatSize(), 1219 Context); 1220 void *InsertPos = 0; 1221 ClassTemplateSpecializationDecl *Decl 1222 = ClassTemplate->getSpecializations().FindNodeOrInsertPos(ID, InsertPos); 1223 if (!Decl) { 1224 // This is the first time we have referenced this class template 1225 // specialization. Create the canonical declaration and add it to 1226 // the set of specializations. 1227 Decl = ClassTemplateSpecializationDecl::Create(Context, 1228 ClassTemplate->getDeclContext(), 1229 ClassTemplate->getLocation(), 1230 ClassTemplate, 1231 Converted, 0); 1232 ClassTemplate->getSpecializations().InsertNode(Decl, InsertPos); 1233 Decl->setLexicalDeclContext(CurContext); 1234 } 1235 1236 CanonType = Context.getTypeDeclType(Decl); 1237 } 1238 1239 // Build the fully-sugared type for this class template 1240 // specialization, which refers back to the class template 1241 // specialization we created or found. 1242 return Context.getTemplateSpecializationType(Name, TemplateArgs, 1243 NumTemplateArgs, CanonType); 1244} 1245 1246Action::TypeResult 1247Sema::ActOnTemplateIdType(TemplateTy TemplateD, SourceLocation TemplateLoc, 1248 SourceLocation LAngleLoc, 1249 ASTTemplateArgsPtr TemplateArgsIn, 1250 SourceLocation RAngleLoc) { 1251 TemplateName Template = TemplateD.getAsVal<TemplateName>(); 1252 1253 // Translate the parser's template argument list in our AST format. 1254 llvm::SmallVector<TemplateArgumentLoc, 16> TemplateArgs; 1255 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 1256 1257 QualType Result = CheckTemplateIdType(Template, TemplateLoc, LAngleLoc, 1258 TemplateArgs.data(), 1259 TemplateArgs.size(), 1260 RAngleLoc); 1261 TemplateArgsIn.release(); 1262 1263 if (Result.isNull()) 1264 return true; 1265 1266 DeclaratorInfo *DI = Context.CreateDeclaratorInfo(Result); 1267 TemplateSpecializationTypeLoc TL 1268 = cast<TemplateSpecializationTypeLoc>(DI->getTypeLoc()); 1269 TL.setTemplateNameLoc(TemplateLoc); 1270 TL.setLAngleLoc(LAngleLoc); 1271 TL.setRAngleLoc(RAngleLoc); 1272 for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i) 1273 TL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); 1274 1275 return CreateLocInfoType(Result, DI).getAsOpaquePtr(); 1276} 1277 1278Sema::TypeResult Sema::ActOnTagTemplateIdType(TypeResult TypeResult, 1279 TagUseKind TUK, 1280 DeclSpec::TST TagSpec, 1281 SourceLocation TagLoc) { 1282 if (TypeResult.isInvalid()) 1283 return Sema::TypeResult(); 1284 1285 // FIXME: preserve source info, ideally without copying the DI. 1286 DeclaratorInfo *DI; 1287 QualType Type = GetTypeFromParser(TypeResult.get(), &DI); 1288 1289 // Verify the tag specifier. 1290 TagDecl::TagKind TagKind = TagDecl::getTagKindForTypeSpec(TagSpec); 1291 1292 if (const RecordType *RT = Type->getAs<RecordType>()) { 1293 RecordDecl *D = RT->getDecl(); 1294 1295 IdentifierInfo *Id = D->getIdentifier(); 1296 assert(Id && "templated class must have an identifier"); 1297 1298 if (!isAcceptableTagRedeclaration(D, TagKind, TagLoc, *Id)) { 1299 Diag(TagLoc, diag::err_use_with_wrong_tag) 1300 << Type 1301 << CodeModificationHint::CreateReplacement(SourceRange(TagLoc), 1302 D->getKindName()); 1303 Diag(D->getLocation(), diag::note_previous_use); 1304 } 1305 } 1306 1307 QualType ElabType = Context.getElaboratedType(Type, TagKind); 1308 1309 return ElabType.getAsOpaquePtr(); 1310} 1311 1312Sema::OwningExprResult Sema::BuildTemplateIdExpr(NestedNameSpecifier *Qualifier, 1313 SourceRange QualifierRange, 1314 TemplateName Template, 1315 SourceLocation TemplateNameLoc, 1316 SourceLocation LAngleLoc, 1317 const TemplateArgumentLoc *TemplateArgs, 1318 unsigned NumTemplateArgs, 1319 SourceLocation RAngleLoc) { 1320 // FIXME: Can we do any checking at this point? I guess we could check the 1321 // template arguments that we have against the template name, if the template 1322 // name refers to a single template. That's not a terribly common case, 1323 // though. 1324 1325 // Cope with an implicit member access in a C++ non-static member function. 1326 NamedDecl *D = Template.getAsTemplateDecl(); 1327 if (!D) 1328 D = Template.getAsOverloadedFunctionDecl(); 1329 1330 CXXScopeSpec SS; 1331 SS.setRange(QualifierRange); 1332 SS.setScopeRep(Qualifier); 1333 QualType ThisType, MemberType; 1334 if (D && isImplicitMemberReference(&SS, D, TemplateNameLoc, 1335 ThisType, MemberType)) { 1336 Expr *This = new (Context) CXXThisExpr(SourceLocation(), ThisType); 1337 return Owned(MemberExpr::Create(Context, This, true, 1338 Qualifier, QualifierRange, 1339 D, TemplateNameLoc, true, 1340 LAngleLoc, TemplateArgs, 1341 NumTemplateArgs, RAngleLoc, 1342 Context.OverloadTy)); 1343 } 1344 1345 return Owned(TemplateIdRefExpr::Create(Context, Context.OverloadTy, 1346 Qualifier, QualifierRange, 1347 Template, TemplateNameLoc, LAngleLoc, 1348 TemplateArgs, 1349 NumTemplateArgs, RAngleLoc)); 1350} 1351 1352Sema::OwningExprResult Sema::ActOnTemplateIdExpr(const CXXScopeSpec &SS, 1353 TemplateTy TemplateD, 1354 SourceLocation TemplateNameLoc, 1355 SourceLocation LAngleLoc, 1356 ASTTemplateArgsPtr TemplateArgsIn, 1357 SourceLocation RAngleLoc) { 1358 TemplateName Template = TemplateD.getAsVal<TemplateName>(); 1359 1360 // Translate the parser's template argument list in our AST format. 1361 llvm::SmallVector<TemplateArgumentLoc, 16> TemplateArgs; 1362 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 1363 TemplateArgsIn.release(); 1364 1365 return BuildTemplateIdExpr((NestedNameSpecifier *)SS.getScopeRep(), 1366 SS.getRange(), 1367 Template, TemplateNameLoc, LAngleLoc, 1368 TemplateArgs.data(), TemplateArgs.size(), 1369 RAngleLoc); 1370} 1371 1372/// \brief Form a dependent template name. 1373/// 1374/// This action forms a dependent template name given the template 1375/// name and its (presumably dependent) scope specifier. For 1376/// example, given "MetaFun::template apply", the scope specifier \p 1377/// SS will be "MetaFun::", \p TemplateKWLoc contains the location 1378/// of the "template" keyword, and "apply" is the \p Name. 1379Sema::TemplateTy 1380Sema::ActOnDependentTemplateName(SourceLocation TemplateKWLoc, 1381 const CXXScopeSpec &SS, 1382 UnqualifiedId &Name, 1383 TypeTy *ObjectType) { 1384 if ((ObjectType && 1385 computeDeclContext(QualType::getFromOpaquePtr(ObjectType))) || 1386 (SS.isSet() && computeDeclContext(SS, false))) { 1387 // C++0x [temp.names]p5: 1388 // If a name prefixed by the keyword template is not the name of 1389 // a template, the program is ill-formed. [Note: the keyword 1390 // template may not be applied to non-template members of class 1391 // templates. -end note ] [ Note: as is the case with the 1392 // typename prefix, the template prefix is allowed in cases 1393 // where it is not strictly necessary; i.e., when the 1394 // nested-name-specifier or the expression on the left of the -> 1395 // or . is not dependent on a template-parameter, or the use 1396 // does not appear in the scope of a template. -end note] 1397 // 1398 // Note: C++03 was more strict here, because it banned the use of 1399 // the "template" keyword prior to a template-name that was not a 1400 // dependent name. C++ DR468 relaxed this requirement (the 1401 // "template" keyword is now permitted). We follow the C++0x 1402 // rules, even in C++03 mode, retroactively applying the DR. 1403 TemplateTy Template; 1404 TemplateNameKind TNK = isTemplateName(0, SS, Name, ObjectType, 1405 false, Template); 1406 if (TNK == TNK_Non_template) { 1407 Diag(Name.getSourceRange().getBegin(), 1408 diag::err_template_kw_refers_to_non_template) 1409 << GetNameFromUnqualifiedId(Name) 1410 << Name.getSourceRange(); 1411 return TemplateTy(); 1412 } 1413 1414 return Template; 1415 } 1416 1417 NestedNameSpecifier *Qualifier 1418 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 1419 1420 switch (Name.getKind()) { 1421 case UnqualifiedId::IK_Identifier: 1422 return TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1423 Name.Identifier)); 1424 1425 case UnqualifiedId::IK_OperatorFunctionId: 1426 return TemplateTy::make(Context.getDependentTemplateName(Qualifier, 1427 Name.OperatorFunctionId.Operator)); 1428 1429 default: 1430 break; 1431 } 1432 1433 Diag(Name.getSourceRange().getBegin(), 1434 diag::err_template_kw_refers_to_non_template) 1435 << GetNameFromUnqualifiedId(Name) 1436 << Name.getSourceRange(); 1437 return TemplateTy(); 1438} 1439 1440bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, 1441 const TemplateArgumentLoc &AL, 1442 TemplateArgumentListBuilder &Converted) { 1443 const TemplateArgument &Arg = AL.getArgument(); 1444 1445 // Check template type parameter. 1446 if (Arg.getKind() != TemplateArgument::Type) { 1447 // C++ [temp.arg.type]p1: 1448 // A template-argument for a template-parameter which is a 1449 // type shall be a type-id. 1450 1451 // We have a template type parameter but the template argument 1452 // is not a type. 1453 SourceRange SR = AL.getSourceRange(); 1454 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; 1455 Diag(Param->getLocation(), diag::note_template_param_here); 1456 1457 return true; 1458 } 1459 1460 if (CheckTemplateArgument(Param, AL.getSourceDeclaratorInfo())) 1461 return true; 1462 1463 // Add the converted template type argument. 1464 Converted.Append( 1465 TemplateArgument(Context.getCanonicalType(Arg.getAsType()))); 1466 return false; 1467} 1468 1469/// \brief Substitute template arguments into the default template argument for 1470/// the given template type parameter. 1471/// 1472/// \param SemaRef the semantic analysis object for which we are performing 1473/// the substitution. 1474/// 1475/// \param Template the template that we are synthesizing template arguments 1476/// for. 1477/// 1478/// \param TemplateLoc the location of the template name that started the 1479/// template-id we are checking. 1480/// 1481/// \param RAngleLoc the location of the right angle bracket ('>') that 1482/// terminates the template-id. 1483/// 1484/// \param Param the template template parameter whose default we are 1485/// substituting into. 1486/// 1487/// \param Converted the list of template arguments provided for template 1488/// parameters that precede \p Param in the template parameter list. 1489/// 1490/// \returns the substituted template argument, or NULL if an error occurred. 1491static DeclaratorInfo * 1492SubstDefaultTemplateArgument(Sema &SemaRef, 1493 TemplateDecl *Template, 1494 SourceLocation TemplateLoc, 1495 SourceLocation RAngleLoc, 1496 TemplateTypeParmDecl *Param, 1497 TemplateArgumentListBuilder &Converted) { 1498 DeclaratorInfo *ArgType = Param->getDefaultArgumentInfo(); 1499 1500 // If the argument type is dependent, instantiate it now based 1501 // on the previously-computed template arguments. 1502 if (ArgType->getType()->isDependentType()) { 1503 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1504 /*TakeArgs=*/false); 1505 1506 MultiLevelTemplateArgumentList AllTemplateArgs 1507 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1508 1509 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1510 Template, Converted.getFlatArguments(), 1511 Converted.flatSize(), 1512 SourceRange(TemplateLoc, RAngleLoc)); 1513 1514 ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs, 1515 Param->getDefaultArgumentLoc(), 1516 Param->getDeclName()); 1517 } 1518 1519 return ArgType; 1520} 1521 1522/// \brief Substitute template arguments into the default template argument for 1523/// the given non-type template parameter. 1524/// 1525/// \param SemaRef the semantic analysis object for which we are performing 1526/// the substitution. 1527/// 1528/// \param Template the template that we are synthesizing template arguments 1529/// for. 1530/// 1531/// \param TemplateLoc the location of the template name that started the 1532/// template-id we are checking. 1533/// 1534/// \param RAngleLoc the location of the right angle bracket ('>') that 1535/// terminates the template-id. 1536/// 1537/// \param Param the non-type template parameter whose default we are 1538/// substituting into. 1539/// 1540/// \param Converted the list of template arguments provided for template 1541/// parameters that precede \p Param in the template parameter list. 1542/// 1543/// \returns the substituted template argument, or NULL if an error occurred. 1544static Sema::OwningExprResult 1545SubstDefaultTemplateArgument(Sema &SemaRef, 1546 TemplateDecl *Template, 1547 SourceLocation TemplateLoc, 1548 SourceLocation RAngleLoc, 1549 NonTypeTemplateParmDecl *Param, 1550 TemplateArgumentListBuilder &Converted) { 1551 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1552 /*TakeArgs=*/false); 1553 1554 MultiLevelTemplateArgumentList AllTemplateArgs 1555 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1556 1557 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1558 Template, Converted.getFlatArguments(), 1559 Converted.flatSize(), 1560 SourceRange(TemplateLoc, RAngleLoc)); 1561 1562 return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs); 1563} 1564 1565/// \brief Substitute template arguments into the default template argument for 1566/// the given template template parameter. 1567/// 1568/// \param SemaRef the semantic analysis object for which we are performing 1569/// the substitution. 1570/// 1571/// \param Template the template that we are synthesizing template arguments 1572/// for. 1573/// 1574/// \param TemplateLoc the location of the template name that started the 1575/// template-id we are checking. 1576/// 1577/// \param RAngleLoc the location of the right angle bracket ('>') that 1578/// terminates the template-id. 1579/// 1580/// \param Param the template template parameter whose default we are 1581/// substituting into. 1582/// 1583/// \param Converted the list of template arguments provided for template 1584/// parameters that precede \p Param in the template parameter list. 1585/// 1586/// \returns the substituted template argument, or NULL if an error occurred. 1587static TemplateName 1588SubstDefaultTemplateArgument(Sema &SemaRef, 1589 TemplateDecl *Template, 1590 SourceLocation TemplateLoc, 1591 SourceLocation RAngleLoc, 1592 TemplateTemplateParmDecl *Param, 1593 TemplateArgumentListBuilder &Converted) { 1594 TemplateArgumentList TemplateArgs(SemaRef.Context, Converted, 1595 /*TakeArgs=*/false); 1596 1597 MultiLevelTemplateArgumentList AllTemplateArgs 1598 = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs); 1599 1600 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, 1601 Template, Converted.getFlatArguments(), 1602 Converted.flatSize(), 1603 SourceRange(TemplateLoc, RAngleLoc)); 1604 1605 return SemaRef.SubstTemplateName( 1606 Param->getDefaultArgument().getArgument().getAsTemplate(), 1607 Param->getDefaultArgument().getTemplateNameLoc(), 1608 AllTemplateArgs); 1609} 1610 1611/// \brief Check that the given template argument corresponds to the given 1612/// template parameter. 1613bool Sema::CheckTemplateArgument(NamedDecl *Param, 1614 const TemplateArgumentLoc &Arg, 1615 TemplateDecl *Template, 1616 SourceLocation TemplateLoc, 1617 SourceLocation RAngleLoc, 1618 TemplateArgumentListBuilder &Converted) { 1619 // Check template type parameters. 1620 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) 1621 return CheckTemplateTypeArgument(TTP, Arg, Converted); 1622 1623 // Check non-type template parameters. 1624 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { 1625 // Do substitution on the type of the non-type template parameter 1626 // with the template arguments we've seen thus far. 1627 QualType NTTPType = NTTP->getType(); 1628 if (NTTPType->isDependentType()) { 1629 // Do substitution on the type of the non-type template parameter. 1630 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 1631 NTTP, Converted.getFlatArguments(), 1632 Converted.flatSize(), 1633 SourceRange(TemplateLoc, RAngleLoc)); 1634 1635 TemplateArgumentList TemplateArgs(Context, Converted, 1636 /*TakeArgs=*/false); 1637 NTTPType = SubstType(NTTPType, 1638 MultiLevelTemplateArgumentList(TemplateArgs), 1639 NTTP->getLocation(), 1640 NTTP->getDeclName()); 1641 // If that worked, check the non-type template parameter type 1642 // for validity. 1643 if (!NTTPType.isNull()) 1644 NTTPType = CheckNonTypeTemplateParameterType(NTTPType, 1645 NTTP->getLocation()); 1646 if (NTTPType.isNull()) 1647 return true; 1648 } 1649 1650 switch (Arg.getArgument().getKind()) { 1651 case TemplateArgument::Null: 1652 assert(false && "Should never see a NULL template argument here"); 1653 return true; 1654 1655 case TemplateArgument::Expression: { 1656 Expr *E = Arg.getArgument().getAsExpr(); 1657 TemplateArgument Result; 1658 if (CheckTemplateArgument(NTTP, NTTPType, E, Result)) 1659 return true; 1660 1661 Converted.Append(Result); 1662 break; 1663 } 1664 1665 case TemplateArgument::Declaration: 1666 case TemplateArgument::Integral: 1667 // We've already checked this template argument, so just copy 1668 // it to the list of converted arguments. 1669 Converted.Append(Arg.getArgument()); 1670 break; 1671 1672 case TemplateArgument::Template: 1673 // We were given a template template argument. It may not be ill-formed; 1674 // see below. 1675 if (DependentTemplateName *DTN 1676 = Arg.getArgument().getAsTemplate().getAsDependentTemplateName()) { 1677 // We have a template argument such as \c T::template X, which we 1678 // parsed as a template template argument. However, since we now 1679 // know that we need a non-type template argument, convert this 1680 // template name into an expression. 1681 Expr *E = new (Context) UnresolvedDeclRefExpr(DTN->getIdentifier(), 1682 Context.DependentTy, 1683 Arg.getTemplateNameLoc(), 1684 Arg.getTemplateQualifierRange(), 1685 DTN->getQualifier(), 1686 /*isAddressOfOperand=*/false); 1687 1688 TemplateArgument Result; 1689 if (CheckTemplateArgument(NTTP, NTTPType, E, Result)) 1690 return true; 1691 1692 Converted.Append(Result); 1693 break; 1694 } 1695 1696 // We have a template argument that actually does refer to a class 1697 // template, template alias, or template template parameter, and 1698 // therefore cannot be a non-type template argument. 1699 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) 1700 << Arg.getSourceRange(); 1701 1702 Diag(Param->getLocation(), diag::note_template_param_here); 1703 return true; 1704 1705 case TemplateArgument::Type: { 1706 // We have a non-type template parameter but the template 1707 // argument is a type. 1708 1709 // C++ [temp.arg]p2: 1710 // In a template-argument, an ambiguity between a type-id and 1711 // an expression is resolved to a type-id, regardless of the 1712 // form of the corresponding template-parameter. 1713 // 1714 // We warn specifically about this case, since it can be rather 1715 // confusing for users. 1716 QualType T = Arg.getArgument().getAsType(); 1717 SourceRange SR = Arg.getSourceRange(); 1718 if (T->isFunctionType()) 1719 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; 1720 else 1721 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; 1722 Diag(Param->getLocation(), diag::note_template_param_here); 1723 return true; 1724 } 1725 1726 case TemplateArgument::Pack: 1727 llvm::llvm_unreachable("Caller must expand template argument packs"); 1728 break; 1729 } 1730 1731 return false; 1732 } 1733 1734 1735 // Check template template parameters. 1736 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param); 1737 1738 // Substitute into the template parameter list of the template 1739 // template parameter, since previously-supplied template arguments 1740 // may appear within the template template parameter. 1741 { 1742 // Set up a template instantiation context. 1743 LocalInstantiationScope Scope(*this); 1744 InstantiatingTemplate Inst(*this, TemplateLoc, Template, 1745 TempParm, Converted.getFlatArguments(), 1746 Converted.flatSize(), 1747 SourceRange(TemplateLoc, RAngleLoc)); 1748 1749 TemplateArgumentList TemplateArgs(Context, Converted, 1750 /*TakeArgs=*/false); 1751 TempParm = cast_or_null<TemplateTemplateParmDecl>( 1752 SubstDecl(TempParm, CurContext, 1753 MultiLevelTemplateArgumentList(TemplateArgs))); 1754 if (!TempParm) 1755 return true; 1756 1757 // FIXME: TempParam is leaked. 1758 } 1759 1760 switch (Arg.getArgument().getKind()) { 1761 case TemplateArgument::Null: 1762 assert(false && "Should never see a NULL template argument here"); 1763 return true; 1764 1765 case TemplateArgument::Template: 1766 if (CheckTemplateArgument(TempParm, Arg)) 1767 return true; 1768 1769 Converted.Append(Arg.getArgument()); 1770 break; 1771 1772 case TemplateArgument::Expression: 1773 case TemplateArgument::Type: 1774 // We have a template template parameter but the template 1775 // argument does not refer to a template. 1776 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template); 1777 return true; 1778 1779 case TemplateArgument::Declaration: 1780 llvm::llvm_unreachable( 1781 "Declaration argument with template template parameter"); 1782 break; 1783 case TemplateArgument::Integral: 1784 llvm::llvm_unreachable( 1785 "Integral argument with template template parameter"); 1786 break; 1787 1788 case TemplateArgument::Pack: 1789 llvm::llvm_unreachable("Caller must expand template argument packs"); 1790 break; 1791 } 1792 1793 return false; 1794} 1795 1796/// \brief Check that the given template argument list is well-formed 1797/// for specializing the given template. 1798bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, 1799 SourceLocation TemplateLoc, 1800 SourceLocation LAngleLoc, 1801 const TemplateArgumentLoc *TemplateArgs, 1802 unsigned NumTemplateArgs, 1803 SourceLocation RAngleLoc, 1804 bool PartialTemplateArgs, 1805 TemplateArgumentListBuilder &Converted) { 1806 TemplateParameterList *Params = Template->getTemplateParameters(); 1807 unsigned NumParams = Params->size(); 1808 unsigned NumArgs = NumTemplateArgs; 1809 bool Invalid = false; 1810 1811 bool HasParameterPack = 1812 NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack(); 1813 1814 if ((NumArgs > NumParams && !HasParameterPack) || 1815 (NumArgs < Params->getMinRequiredArguments() && 1816 !PartialTemplateArgs)) { 1817 // FIXME: point at either the first arg beyond what we can handle, 1818 // or the '>', depending on whether we have too many or too few 1819 // arguments. 1820 SourceRange Range; 1821 if (NumArgs > NumParams) 1822 Range = SourceRange(TemplateArgs[NumParams].getLocation(), RAngleLoc); 1823 Diag(TemplateLoc, diag::err_template_arg_list_different_arity) 1824 << (NumArgs > NumParams) 1825 << (isa<ClassTemplateDecl>(Template)? 0 : 1826 isa<FunctionTemplateDecl>(Template)? 1 : 1827 isa<TemplateTemplateParmDecl>(Template)? 2 : 3) 1828 << Template << Range; 1829 Diag(Template->getLocation(), diag::note_template_decl_here) 1830 << Params->getSourceRange(); 1831 Invalid = true; 1832 } 1833 1834 // C++ [temp.arg]p1: 1835 // [...] The type and form of each template-argument specified in 1836 // a template-id shall match the type and form specified for the 1837 // corresponding parameter declared by the template in its 1838 // template-parameter-list. 1839 unsigned ArgIdx = 0; 1840 for (TemplateParameterList::iterator Param = Params->begin(), 1841 ParamEnd = Params->end(); 1842 Param != ParamEnd; ++Param, ++ArgIdx) { 1843 if (ArgIdx > NumArgs && PartialTemplateArgs) 1844 break; 1845 1846 // If we have a template parameter pack, check every remaining template 1847 // argument against that template parameter pack. 1848 if ((*Param)->isTemplateParameterPack()) { 1849 Converted.BeginPack(); 1850 for (; ArgIdx < NumArgs; ++ArgIdx) { 1851 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 1852 TemplateLoc, RAngleLoc, Converted)) { 1853 Invalid = true; 1854 break; 1855 } 1856 } 1857 Converted.EndPack(); 1858 continue; 1859 } 1860 1861 if (ArgIdx < NumArgs) { 1862 // Check the template argument we were given. 1863 if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, 1864 TemplateLoc, RAngleLoc, Converted)) 1865 return true; 1866 1867 continue; 1868 } 1869 1870 // We have a default template argument that we will use. 1871 TemplateArgumentLoc Arg; 1872 1873 // Retrieve the default template argument from the template 1874 // parameter. For each kind of template parameter, we substitute the 1875 // template arguments provided thus far and any "outer" template arguments 1876 // (when the template parameter was part of a nested template) into 1877 // the default argument. 1878 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) { 1879 if (!TTP->hasDefaultArgument()) { 1880 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 1881 break; 1882 } 1883 1884 DeclaratorInfo *ArgType = SubstDefaultTemplateArgument(*this, 1885 Template, 1886 TemplateLoc, 1887 RAngleLoc, 1888 TTP, 1889 Converted); 1890 if (!ArgType) 1891 return true; 1892 1893 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), 1894 ArgType); 1895 } else if (NonTypeTemplateParmDecl *NTTP 1896 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) { 1897 if (!NTTP->hasDefaultArgument()) { 1898 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 1899 break; 1900 } 1901 1902 Sema::OwningExprResult E = SubstDefaultTemplateArgument(*this, Template, 1903 TemplateLoc, 1904 RAngleLoc, 1905 NTTP, 1906 Converted); 1907 if (E.isInvalid()) 1908 return true; 1909 1910 Expr *Ex = E.takeAs<Expr>(); 1911 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); 1912 } else { 1913 TemplateTemplateParmDecl *TempParm 1914 = cast<TemplateTemplateParmDecl>(*Param); 1915 1916 if (!TempParm->hasDefaultArgument()) { 1917 assert((Invalid || PartialTemplateArgs) && "Missing default argument"); 1918 break; 1919 } 1920 1921 TemplateName Name = SubstDefaultTemplateArgument(*this, Template, 1922 TemplateLoc, 1923 RAngleLoc, 1924 TempParm, 1925 Converted); 1926 if (Name.isNull()) 1927 return true; 1928 1929 Arg = TemplateArgumentLoc(TemplateArgument(Name), 1930 TempParm->getDefaultArgument().getTemplateQualifierRange(), 1931 TempParm->getDefaultArgument().getTemplateNameLoc()); 1932 } 1933 1934 // Introduce an instantiation record that describes where we are using 1935 // the default template argument. 1936 InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param, 1937 Converted.getFlatArguments(), 1938 Converted.flatSize(), 1939 SourceRange(TemplateLoc, RAngleLoc)); 1940 1941 // Check the default template argument. 1942 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, 1943 RAngleLoc, Converted)) 1944 return true; 1945 } 1946 1947 return Invalid; 1948} 1949 1950/// \brief Check a template argument against its corresponding 1951/// template type parameter. 1952/// 1953/// This routine implements the semantics of C++ [temp.arg.type]. It 1954/// returns true if an error occurred, and false otherwise. 1955bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, 1956 DeclaratorInfo *ArgInfo) { 1957 assert(ArgInfo && "invalid DeclaratorInfo"); 1958 QualType Arg = ArgInfo->getType(); 1959 1960 // C++ [temp.arg.type]p2: 1961 // A local type, a type with no linkage, an unnamed type or a type 1962 // compounded from any of these types shall not be used as a 1963 // template-argument for a template type-parameter. 1964 // 1965 // FIXME: Perform the recursive and no-linkage type checks. 1966 const TagType *Tag = 0; 1967 if (const EnumType *EnumT = Arg->getAs<EnumType>()) 1968 Tag = EnumT; 1969 else if (const RecordType *RecordT = Arg->getAs<RecordType>()) 1970 Tag = RecordT; 1971 if (Tag && Tag->getDecl()->getDeclContext()->isFunctionOrMethod()) { 1972 SourceRange SR = ArgInfo->getTypeLoc().getFullSourceRange(); 1973 return Diag(SR.getBegin(), diag::err_template_arg_local_type) 1974 << QualType(Tag, 0) << SR; 1975 } else if (Tag && !Tag->getDecl()->getDeclName() && 1976 !Tag->getDecl()->getTypedefForAnonDecl()) { 1977 SourceRange SR = ArgInfo->getTypeLoc().getFullSourceRange(); 1978 Diag(SR.getBegin(), diag::err_template_arg_unnamed_type) << SR; 1979 Diag(Tag->getDecl()->getLocation(), diag::note_template_unnamed_type_here); 1980 return true; 1981 } 1982 1983 return false; 1984} 1985 1986/// \brief Checks whether the given template argument is the address 1987/// of an object or function according to C++ [temp.arg.nontype]p1. 1988bool Sema::CheckTemplateArgumentAddressOfObjectOrFunction(Expr *Arg, 1989 NamedDecl *&Entity) { 1990 bool Invalid = false; 1991 1992 // See through any implicit casts we added to fix the type. 1993 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 1994 Arg = Cast->getSubExpr(); 1995 1996 // C++0x allows nullptr, and there's no further checking to be done for that. 1997 if (Arg->getType()->isNullPtrType()) 1998 return false; 1999 2000 // C++ [temp.arg.nontype]p1: 2001 // 2002 // A template-argument for a non-type, non-template 2003 // template-parameter shall be one of: [...] 2004 // 2005 // -- the address of an object or function with external 2006 // linkage, including function templates and function 2007 // template-ids but excluding non-static class members, 2008 // expressed as & id-expression where the & is optional if 2009 // the name refers to a function or array, or if the 2010 // corresponding template-parameter is a reference; or 2011 DeclRefExpr *DRE = 0; 2012 2013 // Ignore (and complain about) any excess parentheses. 2014 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2015 if (!Invalid) { 2016 Diag(Arg->getSourceRange().getBegin(), 2017 diag::err_template_arg_extra_parens) 2018 << Arg->getSourceRange(); 2019 Invalid = true; 2020 } 2021 2022 Arg = Parens->getSubExpr(); 2023 } 2024 2025 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2026 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 2027 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2028 } else 2029 DRE = dyn_cast<DeclRefExpr>(Arg); 2030 2031 if (!DRE || !isa<ValueDecl>(DRE->getDecl())) 2032 return Diag(Arg->getSourceRange().getBegin(), 2033 diag::err_template_arg_not_object_or_func_form) 2034 << Arg->getSourceRange(); 2035 2036 // Cannot refer to non-static data members 2037 if (FieldDecl *Field = dyn_cast<FieldDecl>(DRE->getDecl())) 2038 return Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_field) 2039 << Field << Arg->getSourceRange(); 2040 2041 // Cannot refer to non-static member functions 2042 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(DRE->getDecl())) 2043 if (!Method->isStatic()) 2044 return Diag(Arg->getSourceRange().getBegin(), 2045 diag::err_template_arg_method) 2046 << Method << Arg->getSourceRange(); 2047 2048 // Functions must have external linkage. 2049 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(DRE->getDecl())) { 2050 if (Func->getStorageClass() == FunctionDecl::Static) { 2051 Diag(Arg->getSourceRange().getBegin(), 2052 diag::err_template_arg_function_not_extern) 2053 << Func << Arg->getSourceRange(); 2054 Diag(Func->getLocation(), diag::note_template_arg_internal_object) 2055 << true; 2056 return true; 2057 } 2058 2059 // Okay: we've named a function with external linkage. 2060 Entity = Func; 2061 return Invalid; 2062 } 2063 2064 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 2065 if (!Var->hasGlobalStorage()) { 2066 Diag(Arg->getSourceRange().getBegin(), 2067 diag::err_template_arg_object_not_extern) 2068 << Var << Arg->getSourceRange(); 2069 Diag(Var->getLocation(), diag::note_template_arg_internal_object) 2070 << true; 2071 return true; 2072 } 2073 2074 // Okay: we've named an object with external linkage 2075 Entity = Var; 2076 return Invalid; 2077 } 2078 2079 // We found something else, but we don't know specifically what it is. 2080 Diag(Arg->getSourceRange().getBegin(), 2081 diag::err_template_arg_not_object_or_func) 2082 << Arg->getSourceRange(); 2083 Diag(DRE->getDecl()->getLocation(), 2084 diag::note_template_arg_refers_here); 2085 return true; 2086} 2087 2088/// \brief Checks whether the given template argument is a pointer to 2089/// member constant according to C++ [temp.arg.nontype]p1. 2090bool Sema::CheckTemplateArgumentPointerToMember(Expr *Arg, 2091 TemplateArgument &Converted) { 2092 bool Invalid = false; 2093 2094 // See through any implicit casts we added to fix the type. 2095 while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg)) 2096 Arg = Cast->getSubExpr(); 2097 2098 // C++0x allows nullptr, and there's no further checking to be done for that. 2099 if (Arg->getType()->isNullPtrType()) 2100 return false; 2101 2102 // C++ [temp.arg.nontype]p1: 2103 // 2104 // A template-argument for a non-type, non-template 2105 // template-parameter shall be one of: [...] 2106 // 2107 // -- a pointer to member expressed as described in 5.3.1. 2108 DeclRefExpr *DRE = 0; 2109 2110 // Ignore (and complain about) any excess parentheses. 2111 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) { 2112 if (!Invalid) { 2113 Diag(Arg->getSourceRange().getBegin(), 2114 diag::err_template_arg_extra_parens) 2115 << Arg->getSourceRange(); 2116 Invalid = true; 2117 } 2118 2119 Arg = Parens->getSubExpr(); 2120 } 2121 2122 // A pointer-to-member constant written &Class::member. 2123 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) { 2124 if (UnOp->getOpcode() == UnaryOperator::AddrOf) { 2125 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr()); 2126 if (DRE && !DRE->getQualifier()) 2127 DRE = 0; 2128 } 2129 } 2130 // A constant of pointer-to-member type. 2131 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) { 2132 if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) { 2133 if (VD->getType()->isMemberPointerType()) { 2134 if (isa<NonTypeTemplateParmDecl>(VD) || 2135 (isa<VarDecl>(VD) && 2136 Context.getCanonicalType(VD->getType()).isConstQualified())) { 2137 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2138 Converted = TemplateArgument(Arg->Retain()); 2139 else 2140 Converted = TemplateArgument(VD->getCanonicalDecl()); 2141 return Invalid; 2142 } 2143 } 2144 } 2145 2146 DRE = 0; 2147 } 2148 2149 if (!DRE) 2150 return Diag(Arg->getSourceRange().getBegin(), 2151 diag::err_template_arg_not_pointer_to_member_form) 2152 << Arg->getSourceRange(); 2153 2154 if (isa<FieldDecl>(DRE->getDecl()) || isa<CXXMethodDecl>(DRE->getDecl())) { 2155 assert((isa<FieldDecl>(DRE->getDecl()) || 2156 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && 2157 "Only non-static member pointers can make it here"); 2158 2159 // Okay: this is the address of a non-static member, and therefore 2160 // a member pointer constant. 2161 if (Arg->isTypeDependent() || Arg->isValueDependent()) 2162 Converted = TemplateArgument(Arg->Retain()); 2163 else 2164 Converted = TemplateArgument(DRE->getDecl()->getCanonicalDecl()); 2165 return Invalid; 2166 } 2167 2168 // We found something else, but we don't know specifically what it is. 2169 Diag(Arg->getSourceRange().getBegin(), 2170 diag::err_template_arg_not_pointer_to_member_form) 2171 << Arg->getSourceRange(); 2172 Diag(DRE->getDecl()->getLocation(), 2173 diag::note_template_arg_refers_here); 2174 return true; 2175} 2176 2177/// \brief Check a template argument against its corresponding 2178/// non-type template parameter. 2179/// 2180/// This routine implements the semantics of C++ [temp.arg.nontype]. 2181/// It returns true if an error occurred, and false otherwise. \p 2182/// InstantiatedParamType is the type of the non-type template 2183/// parameter after it has been instantiated. 2184/// 2185/// If no error was detected, Converted receives the converted template argument. 2186bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, 2187 QualType InstantiatedParamType, Expr *&Arg, 2188 TemplateArgument &Converted) { 2189 SourceLocation StartLoc = Arg->getSourceRange().getBegin(); 2190 2191 // If either the parameter has a dependent type or the argument is 2192 // type-dependent, there's nothing we can check now. 2193 // FIXME: Add template argument to Converted! 2194 if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) { 2195 // FIXME: Produce a cloned, canonical expression? 2196 Converted = TemplateArgument(Arg); 2197 return false; 2198 } 2199 2200 // C++ [temp.arg.nontype]p5: 2201 // The following conversions are performed on each expression used 2202 // as a non-type template-argument. If a non-type 2203 // template-argument cannot be converted to the type of the 2204 // corresponding template-parameter then the program is 2205 // ill-formed. 2206 // 2207 // -- for a non-type template-parameter of integral or 2208 // enumeration type, integral promotions (4.5) and integral 2209 // conversions (4.7) are applied. 2210 QualType ParamType = InstantiatedParamType; 2211 QualType ArgType = Arg->getType(); 2212 if (ParamType->isIntegralType() || ParamType->isEnumeralType()) { 2213 // C++ [temp.arg.nontype]p1: 2214 // A template-argument for a non-type, non-template 2215 // template-parameter shall be one of: 2216 // 2217 // -- an integral constant-expression of integral or enumeration 2218 // type; or 2219 // -- the name of a non-type template-parameter; or 2220 SourceLocation NonConstantLoc; 2221 llvm::APSInt Value; 2222 if (!ArgType->isIntegralType() && !ArgType->isEnumeralType()) { 2223 Diag(Arg->getSourceRange().getBegin(), 2224 diag::err_template_arg_not_integral_or_enumeral) 2225 << ArgType << Arg->getSourceRange(); 2226 Diag(Param->getLocation(), diag::note_template_param_here); 2227 return true; 2228 } else if (!Arg->isValueDependent() && 2229 !Arg->isIntegerConstantExpr(Value, Context, &NonConstantLoc)) { 2230 Diag(NonConstantLoc, diag::err_template_arg_not_ice) 2231 << ArgType << Arg->getSourceRange(); 2232 return true; 2233 } 2234 2235 // FIXME: We need some way to more easily get the unqualified form 2236 // of the types without going all the way to the 2237 // canonical type. 2238 if (Context.getCanonicalType(ParamType).getCVRQualifiers()) 2239 ParamType = Context.getCanonicalType(ParamType).getUnqualifiedType(); 2240 if (Context.getCanonicalType(ArgType).getCVRQualifiers()) 2241 ArgType = Context.getCanonicalType(ArgType).getUnqualifiedType(); 2242 2243 // Try to convert the argument to the parameter's type. 2244 if (Context.hasSameType(ParamType, ArgType)) { 2245 // Okay: no conversion necessary 2246 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || 2247 !ParamType->isEnumeralType()) { 2248 // This is an integral promotion or conversion. 2249 ImpCastExprToType(Arg, ParamType, CastExpr::CK_IntegralCast); 2250 } else { 2251 // We can't perform this conversion. 2252 Diag(Arg->getSourceRange().getBegin(), 2253 diag::err_template_arg_not_convertible) 2254 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2255 Diag(Param->getLocation(), diag::note_template_param_here); 2256 return true; 2257 } 2258 2259 QualType IntegerType = Context.getCanonicalType(ParamType); 2260 if (const EnumType *Enum = IntegerType->getAs<EnumType>()) 2261 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); 2262 2263 if (!Arg->isValueDependent()) { 2264 // Check that an unsigned parameter does not receive a negative 2265 // value. 2266 if (IntegerType->isUnsignedIntegerType() 2267 && (Value.isSigned() && Value.isNegative())) { 2268 Diag(Arg->getSourceRange().getBegin(), diag::err_template_arg_negative) 2269 << Value.toString(10) << Param->getType() 2270 << Arg->getSourceRange(); 2271 Diag(Param->getLocation(), diag::note_template_param_here); 2272 return true; 2273 } 2274 2275 // Check that we don't overflow the template parameter type. 2276 unsigned AllowedBits = Context.getTypeSize(IntegerType); 2277 if (Value.getActiveBits() > AllowedBits) { 2278 Diag(Arg->getSourceRange().getBegin(), 2279 diag::err_template_arg_too_large) 2280 << Value.toString(10) << Param->getType() 2281 << Arg->getSourceRange(); 2282 Diag(Param->getLocation(), diag::note_template_param_here); 2283 return true; 2284 } 2285 2286 if (Value.getBitWidth() != AllowedBits) 2287 Value.extOrTrunc(AllowedBits); 2288 Value.setIsSigned(IntegerType->isSignedIntegerType()); 2289 } 2290 2291 // Add the value of this argument to the list of converted 2292 // arguments. We use the bitwidth and signedness of the template 2293 // parameter. 2294 if (Arg->isValueDependent()) { 2295 // The argument is value-dependent. Create a new 2296 // TemplateArgument with the converted expression. 2297 Converted = TemplateArgument(Arg); 2298 return false; 2299 } 2300 2301 Converted = TemplateArgument(Value, 2302 ParamType->isEnumeralType() ? ParamType 2303 : IntegerType); 2304 return false; 2305 } 2306 2307 // Handle pointer-to-function, reference-to-function, and 2308 // pointer-to-member-function all in (roughly) the same way. 2309 if (// -- For a non-type template-parameter of type pointer to 2310 // function, only the function-to-pointer conversion (4.3) is 2311 // applied. If the template-argument represents a set of 2312 // overloaded functions (or a pointer to such), the matching 2313 // function is selected from the set (13.4). 2314 // In C++0x, any std::nullptr_t value can be converted. 2315 (ParamType->isPointerType() && 2316 ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) || 2317 // -- For a non-type template-parameter of type reference to 2318 // function, no conversions apply. If the template-argument 2319 // represents a set of overloaded functions, the matching 2320 // function is selected from the set (13.4). 2321 (ParamType->isReferenceType() && 2322 ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) || 2323 // -- For a non-type template-parameter of type pointer to 2324 // member function, no conversions apply. If the 2325 // template-argument represents a set of overloaded member 2326 // functions, the matching member function is selected from 2327 // the set (13.4). 2328 // Again, C++0x allows a std::nullptr_t value. 2329 (ParamType->isMemberPointerType() && 2330 ParamType->getAs<MemberPointerType>()->getPointeeType() 2331 ->isFunctionType())) { 2332 if (Context.hasSameUnqualifiedType(ArgType, 2333 ParamType.getNonReferenceType())) { 2334 // We don't have to do anything: the types already match. 2335 } else if (ArgType->isNullPtrType() && (ParamType->isPointerType() || 2336 ParamType->isMemberPointerType())) { 2337 ArgType = ParamType; 2338 if (ParamType->isMemberPointerType()) 2339 ImpCastExprToType(Arg, ParamType, CastExpr::CK_NullToMemberPointer); 2340 else 2341 ImpCastExprToType(Arg, ParamType, CastExpr::CK_BitCast); 2342 } else if (ArgType->isFunctionType() && ParamType->isPointerType()) { 2343 ArgType = Context.getPointerType(ArgType); 2344 ImpCastExprToType(Arg, ArgType, CastExpr::CK_FunctionToPointerDecay); 2345 } else if (FunctionDecl *Fn 2346 = ResolveAddressOfOverloadedFunction(Arg, ParamType, true)) { 2347 if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin())) 2348 return true; 2349 2350 Arg = FixOverloadedFunctionReference(Arg, Fn); 2351 ArgType = Arg->getType(); 2352 if (ArgType->isFunctionType() && ParamType->isPointerType()) { 2353 ArgType = Context.getPointerType(Arg->getType()); 2354 ImpCastExprToType(Arg, ArgType, CastExpr::CK_FunctionToPointerDecay); 2355 } 2356 } 2357 2358 if (!Context.hasSameUnqualifiedType(ArgType, 2359 ParamType.getNonReferenceType())) { 2360 // We can't perform this conversion. 2361 Diag(Arg->getSourceRange().getBegin(), 2362 diag::err_template_arg_not_convertible) 2363 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2364 Diag(Param->getLocation(), diag::note_template_param_here); 2365 return true; 2366 } 2367 2368 if (ParamType->isMemberPointerType()) 2369 return CheckTemplateArgumentPointerToMember(Arg, Converted); 2370 2371 NamedDecl *Entity = 0; 2372 if (CheckTemplateArgumentAddressOfObjectOrFunction(Arg, Entity)) 2373 return true; 2374 2375 if (Entity) 2376 Entity = cast<NamedDecl>(Entity->getCanonicalDecl()); 2377 Converted = TemplateArgument(Entity); 2378 return false; 2379 } 2380 2381 if (ParamType->isPointerType()) { 2382 // -- for a non-type template-parameter of type pointer to 2383 // object, qualification conversions (4.4) and the 2384 // array-to-pointer conversion (4.2) are applied. 2385 // C++0x also allows a value of std::nullptr_t. 2386 assert(ParamType->getAs<PointerType>()->getPointeeType()->isObjectType() && 2387 "Only object pointers allowed here"); 2388 2389 if (ArgType->isNullPtrType()) { 2390 ArgType = ParamType; 2391 ImpCastExprToType(Arg, ParamType, CastExpr::CK_BitCast); 2392 } else if (ArgType->isArrayType()) { 2393 ArgType = Context.getArrayDecayedType(ArgType); 2394 ImpCastExprToType(Arg, ArgType, CastExpr::CK_ArrayToPointerDecay); 2395 } 2396 2397 if (IsQualificationConversion(ArgType, ParamType)) { 2398 ArgType = ParamType; 2399 ImpCastExprToType(Arg, ParamType, CastExpr::CK_NoOp); 2400 } 2401 2402 if (!Context.hasSameUnqualifiedType(ArgType, ParamType)) { 2403 // We can't perform this conversion. 2404 Diag(Arg->getSourceRange().getBegin(), 2405 diag::err_template_arg_not_convertible) 2406 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2407 Diag(Param->getLocation(), diag::note_template_param_here); 2408 return true; 2409 } 2410 2411 NamedDecl *Entity = 0; 2412 if (CheckTemplateArgumentAddressOfObjectOrFunction(Arg, Entity)) 2413 return true; 2414 2415 if (Entity) 2416 Entity = cast<NamedDecl>(Entity->getCanonicalDecl()); 2417 Converted = TemplateArgument(Entity); 2418 return false; 2419 } 2420 2421 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) { 2422 // -- For a non-type template-parameter of type reference to 2423 // object, no conversions apply. The type referred to by the 2424 // reference may be more cv-qualified than the (otherwise 2425 // identical) type of the template-argument. The 2426 // template-parameter is bound directly to the 2427 // template-argument, which must be an lvalue. 2428 assert(ParamRefType->getPointeeType()->isObjectType() && 2429 "Only object references allowed here"); 2430 2431 if (!Context.hasSameUnqualifiedType(ParamRefType->getPointeeType(), ArgType)) { 2432 Diag(Arg->getSourceRange().getBegin(), 2433 diag::err_template_arg_no_ref_bind) 2434 << InstantiatedParamType << Arg->getType() 2435 << Arg->getSourceRange(); 2436 Diag(Param->getLocation(), diag::note_template_param_here); 2437 return true; 2438 } 2439 2440 unsigned ParamQuals 2441 = Context.getCanonicalType(ParamType).getCVRQualifiers(); 2442 unsigned ArgQuals = Context.getCanonicalType(ArgType).getCVRQualifiers(); 2443 2444 if ((ParamQuals | ArgQuals) != ParamQuals) { 2445 Diag(Arg->getSourceRange().getBegin(), 2446 diag::err_template_arg_ref_bind_ignores_quals) 2447 << InstantiatedParamType << Arg->getType() 2448 << Arg->getSourceRange(); 2449 Diag(Param->getLocation(), diag::note_template_param_here); 2450 return true; 2451 } 2452 2453 NamedDecl *Entity = 0; 2454 if (CheckTemplateArgumentAddressOfObjectOrFunction(Arg, Entity)) 2455 return true; 2456 2457 Entity = cast<NamedDecl>(Entity->getCanonicalDecl()); 2458 Converted = TemplateArgument(Entity); 2459 return false; 2460 } 2461 2462 // -- For a non-type template-parameter of type pointer to data 2463 // member, qualification conversions (4.4) are applied. 2464 // C++0x allows std::nullptr_t values. 2465 assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); 2466 2467 if (Context.hasSameUnqualifiedType(ParamType, ArgType)) { 2468 // Types match exactly: nothing more to do here. 2469 } else if (ArgType->isNullPtrType()) { 2470 ImpCastExprToType(Arg, ParamType, CastExpr::CK_NullToMemberPointer); 2471 } else if (IsQualificationConversion(ArgType, ParamType)) { 2472 ImpCastExprToType(Arg, ParamType, CastExpr::CK_NoOp); 2473 } else { 2474 // We can't perform this conversion. 2475 Diag(Arg->getSourceRange().getBegin(), 2476 diag::err_template_arg_not_convertible) 2477 << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); 2478 Diag(Param->getLocation(), diag::note_template_param_here); 2479 return true; 2480 } 2481 2482 return CheckTemplateArgumentPointerToMember(Arg, Converted); 2483} 2484 2485/// \brief Check a template argument against its corresponding 2486/// template template parameter. 2487/// 2488/// This routine implements the semantics of C++ [temp.arg.template]. 2489/// It returns true if an error occurred, and false otherwise. 2490bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, 2491 const TemplateArgumentLoc &Arg) { 2492 TemplateName Name = Arg.getArgument().getAsTemplate(); 2493 TemplateDecl *Template = Name.getAsTemplateDecl(); 2494 if (!Template) { 2495 // Any dependent template name is fine. 2496 assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); 2497 return false; 2498 } 2499 2500 // C++ [temp.arg.template]p1: 2501 // A template-argument for a template template-parameter shall be 2502 // the name of a class template, expressed as id-expression. Only 2503 // primary class templates are considered when matching the 2504 // template template argument with the corresponding parameter; 2505 // partial specializations are not considered even if their 2506 // parameter lists match that of the template template parameter. 2507 // 2508 // Note that we also allow template template parameters here, which 2509 // will happen when we are dealing with, e.g., class template 2510 // partial specializations. 2511 if (!isa<ClassTemplateDecl>(Template) && 2512 !isa<TemplateTemplateParmDecl>(Template)) { 2513 assert(isa<FunctionTemplateDecl>(Template) && 2514 "Only function templates are possible here"); 2515 Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); 2516 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) 2517 << Template; 2518 } 2519 2520 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), 2521 Param->getTemplateParameters(), 2522 true, 2523 TPL_TemplateTemplateArgumentMatch, 2524 Arg.getLocation()); 2525} 2526 2527/// \brief Determine whether the given template parameter lists are 2528/// equivalent. 2529/// 2530/// \param New The new template parameter list, typically written in the 2531/// source code as part of a new template declaration. 2532/// 2533/// \param Old The old template parameter list, typically found via 2534/// name lookup of the template declared with this template parameter 2535/// list. 2536/// 2537/// \param Complain If true, this routine will produce a diagnostic if 2538/// the template parameter lists are not equivalent. 2539/// 2540/// \param Kind describes how we are to match the template parameter lists. 2541/// 2542/// \param TemplateArgLoc If this source location is valid, then we 2543/// are actually checking the template parameter list of a template 2544/// argument (New) against the template parameter list of its 2545/// corresponding template template parameter (Old). We produce 2546/// slightly different diagnostics in this scenario. 2547/// 2548/// \returns True if the template parameter lists are equal, false 2549/// otherwise. 2550bool 2551Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, 2552 TemplateParameterList *Old, 2553 bool Complain, 2554 TemplateParameterListEqualKind Kind, 2555 SourceLocation TemplateArgLoc) { 2556 if (Old->size() != New->size()) { 2557 if (Complain) { 2558 unsigned NextDiag = diag::err_template_param_list_different_arity; 2559 if (TemplateArgLoc.isValid()) { 2560 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 2561 NextDiag = diag::note_template_param_list_different_arity; 2562 } 2563 Diag(New->getTemplateLoc(), NextDiag) 2564 << (New->size() > Old->size()) 2565 << (Kind != TPL_TemplateMatch) 2566 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); 2567 Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) 2568 << (Kind != TPL_TemplateMatch) 2569 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); 2570 } 2571 2572 return false; 2573 } 2574 2575 for (TemplateParameterList::iterator OldParm = Old->begin(), 2576 OldParmEnd = Old->end(), NewParm = New->begin(); 2577 OldParm != OldParmEnd; ++OldParm, ++NewParm) { 2578 if ((*OldParm)->getKind() != (*NewParm)->getKind()) { 2579 if (Complain) { 2580 unsigned NextDiag = diag::err_template_param_different_kind; 2581 if (TemplateArgLoc.isValid()) { 2582 Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); 2583 NextDiag = diag::note_template_param_different_kind; 2584 } 2585 Diag((*NewParm)->getLocation(), NextDiag) 2586 << (Kind != TPL_TemplateMatch); 2587 Diag((*OldParm)->getLocation(), diag::note_template_prev_declaration) 2588 << (Kind != TPL_TemplateMatch); 2589 } 2590 return false; 2591 } 2592 2593 if (isa<TemplateTypeParmDecl>(*OldParm)) { 2594 // Okay; all template type parameters are equivalent (since we 2595 // know we're at the same index). 2596 } else if (NonTypeTemplateParmDecl *OldNTTP 2597 = dyn_cast<NonTypeTemplateParmDecl>(*OldParm)) { 2598 // The types of non-type template parameters must agree. 2599 NonTypeTemplateParmDecl *NewNTTP 2600 = cast<NonTypeTemplateParmDecl>(*NewParm); 2601 2602 // If we are matching a template template argument to a template 2603 // template parameter and one of the non-type template parameter types 2604 // is dependent, then we must wait until template instantiation time 2605 // to actually compare the arguments. 2606 if (Kind == TPL_TemplateTemplateArgumentMatch && 2607 (OldNTTP->getType()->isDependentType() || 2608 NewNTTP->getType()->isDependentType())) 2609 continue; 2610 2611 if (Context.getCanonicalType(OldNTTP->getType()) != 2612 Context.getCanonicalType(NewNTTP->getType())) { 2613 if (Complain) { 2614 unsigned NextDiag = diag::err_template_nontype_parm_different_type; 2615 if (TemplateArgLoc.isValid()) { 2616 Diag(TemplateArgLoc, 2617 diag::err_template_arg_template_params_mismatch); 2618 NextDiag = diag::note_template_nontype_parm_different_type; 2619 } 2620 Diag(NewNTTP->getLocation(), NextDiag) 2621 << NewNTTP->getType() 2622 << (Kind != TPL_TemplateMatch); 2623 Diag(OldNTTP->getLocation(), 2624 diag::note_template_nontype_parm_prev_declaration) 2625 << OldNTTP->getType(); 2626 } 2627 return false; 2628 } 2629 } else { 2630 // The template parameter lists of template template 2631 // parameters must agree. 2632 assert(isa<TemplateTemplateParmDecl>(*OldParm) && 2633 "Only template template parameters handled here"); 2634 TemplateTemplateParmDecl *OldTTP 2635 = cast<TemplateTemplateParmDecl>(*OldParm); 2636 TemplateTemplateParmDecl *NewTTP 2637 = cast<TemplateTemplateParmDecl>(*NewParm); 2638 if (!TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), 2639 OldTTP->getTemplateParameters(), 2640 Complain, 2641 (Kind == TPL_TemplateMatch? TPL_TemplateTemplateParmMatch : Kind), 2642 TemplateArgLoc)) 2643 return false; 2644 } 2645 } 2646 2647 return true; 2648} 2649 2650/// \brief Check whether a template can be declared within this scope. 2651/// 2652/// If the template declaration is valid in this scope, returns 2653/// false. Otherwise, issues a diagnostic and returns true. 2654bool 2655Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { 2656 // Find the nearest enclosing declaration scope. 2657 while ((S->getFlags() & Scope::DeclScope) == 0 || 2658 (S->getFlags() & Scope::TemplateParamScope) != 0) 2659 S = S->getParent(); 2660 2661 // C++ [temp]p2: 2662 // A template-declaration can appear only as a namespace scope or 2663 // class scope declaration. 2664 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 2665 if (Ctx && isa<LinkageSpecDecl>(Ctx) && 2666 cast<LinkageSpecDecl>(Ctx)->getLanguage() != LinkageSpecDecl::lang_cxx) 2667 return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) 2668 << TemplateParams->getSourceRange(); 2669 2670 while (Ctx && isa<LinkageSpecDecl>(Ctx)) 2671 Ctx = Ctx->getParent(); 2672 2673 if (Ctx && (Ctx->isFileContext() || Ctx->isRecord())) 2674 return false; 2675 2676 return Diag(TemplateParams->getTemplateLoc(), 2677 diag::err_template_outside_namespace_or_class_scope) 2678 << TemplateParams->getSourceRange(); 2679} 2680 2681/// \brief Determine what kind of template specialization the given declaration 2682/// is. 2683static TemplateSpecializationKind getTemplateSpecializationKind(NamedDecl *D) { 2684 if (!D) 2685 return TSK_Undeclared; 2686 2687 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) 2688 return Record->getTemplateSpecializationKind(); 2689 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) 2690 return Function->getTemplateSpecializationKind(); 2691 if (VarDecl *Var = dyn_cast<VarDecl>(D)) 2692 return Var->getTemplateSpecializationKind(); 2693 2694 return TSK_Undeclared; 2695} 2696 2697/// \brief Check whether a specialization is well-formed in the current 2698/// context. 2699/// 2700/// This routine determines whether a template specialization can be declared 2701/// in the current context (C++ [temp.expl.spec]p2). 2702/// 2703/// \param S the semantic analysis object for which this check is being 2704/// performed. 2705/// 2706/// \param Specialized the entity being specialized or instantiated, which 2707/// may be a kind of template (class template, function template, etc.) or 2708/// a member of a class template (member function, static data member, 2709/// member class). 2710/// 2711/// \param PrevDecl the previous declaration of this entity, if any. 2712/// 2713/// \param Loc the location of the explicit specialization or instantiation of 2714/// this entity. 2715/// 2716/// \param IsPartialSpecialization whether this is a partial specialization of 2717/// a class template. 2718/// 2719/// \returns true if there was an error that we cannot recover from, false 2720/// otherwise. 2721static bool CheckTemplateSpecializationScope(Sema &S, 2722 NamedDecl *Specialized, 2723 NamedDecl *PrevDecl, 2724 SourceLocation Loc, 2725 bool IsPartialSpecialization) { 2726 // Keep these "kind" numbers in sync with the %select statements in the 2727 // various diagnostics emitted by this routine. 2728 int EntityKind = 0; 2729 bool isTemplateSpecialization = false; 2730 if (isa<ClassTemplateDecl>(Specialized)) { 2731 EntityKind = IsPartialSpecialization? 1 : 0; 2732 isTemplateSpecialization = true; 2733 } else if (isa<FunctionTemplateDecl>(Specialized)) { 2734 EntityKind = 2; 2735 isTemplateSpecialization = true; 2736 } else if (isa<CXXMethodDecl>(Specialized)) 2737 EntityKind = 3; 2738 else if (isa<VarDecl>(Specialized)) 2739 EntityKind = 4; 2740 else if (isa<RecordDecl>(Specialized)) 2741 EntityKind = 5; 2742 else { 2743 S.Diag(Loc, diag::err_template_spec_unknown_kind); 2744 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 2745 return true; 2746 } 2747 2748 // C++ [temp.expl.spec]p2: 2749 // An explicit specialization shall be declared in the namespace 2750 // of which the template is a member, or, for member templates, in 2751 // the namespace of which the enclosing class or enclosing class 2752 // template is a member. An explicit specialization of a member 2753 // function, member class or static data member of a class 2754 // template shall be declared in the namespace of which the class 2755 // template is a member. Such a declaration may also be a 2756 // definition. If the declaration is not a definition, the 2757 // specialization may be defined later in the name- space in which 2758 // the explicit specialization was declared, or in a namespace 2759 // that encloses the one in which the explicit specialization was 2760 // declared. 2761 if (S.CurContext->getLookupContext()->isFunctionOrMethod()) { 2762 S.Diag(Loc, diag::err_template_spec_decl_function_scope) 2763 << Specialized; 2764 return true; 2765 } 2766 2767 if (S.CurContext->isRecord() && !IsPartialSpecialization) { 2768 S.Diag(Loc, diag::err_template_spec_decl_class_scope) 2769 << Specialized; 2770 return true; 2771 } 2772 2773 // C++ [temp.class.spec]p6: 2774 // A class template partial specialization may be declared or redeclared 2775 // in any namespace scope in which its definition may be defined (14.5.1 2776 // and 14.5.2). 2777 bool ComplainedAboutScope = false; 2778 DeclContext *SpecializedContext 2779 = Specialized->getDeclContext()->getEnclosingNamespaceContext(); 2780 DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); 2781 if ((!PrevDecl || 2782 getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || 2783 getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)){ 2784 // There is no prior declaration of this entity, so this 2785 // specialization must be in the same context as the template 2786 // itself. 2787 if (!DC->Equals(SpecializedContext)) { 2788 if (isa<TranslationUnitDecl>(SpecializedContext)) 2789 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global) 2790 << EntityKind << Specialized; 2791 else if (isa<NamespaceDecl>(SpecializedContext)) 2792 S.Diag(Loc, diag::err_template_spec_decl_out_of_scope) 2793 << EntityKind << Specialized 2794 << cast<NamedDecl>(SpecializedContext); 2795 2796 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 2797 ComplainedAboutScope = true; 2798 } 2799 } 2800 2801 // Make sure that this redeclaration (or definition) occurs in an enclosing 2802 // namespace. 2803 // Note that HandleDeclarator() performs this check for explicit 2804 // specializations of function templates, static data members, and member 2805 // functions, so we skip the check here for those kinds of entities. 2806 // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. 2807 // Should we refactor that check, so that it occurs later? 2808 if (!ComplainedAboutScope && !DC->Encloses(SpecializedContext) && 2809 !(isa<FunctionTemplateDecl>(Specialized) || isa<VarDecl>(Specialized) || 2810 isa<FunctionDecl>(Specialized))) { 2811 if (isa<TranslationUnitDecl>(SpecializedContext)) 2812 S.Diag(Loc, diag::err_template_spec_redecl_global_scope) 2813 << EntityKind << Specialized; 2814 else if (isa<NamespaceDecl>(SpecializedContext)) 2815 S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope) 2816 << EntityKind << Specialized 2817 << cast<NamedDecl>(SpecializedContext); 2818 2819 S.Diag(Specialized->getLocation(), diag::note_specialized_entity); 2820 } 2821 2822 // FIXME: check for specialization-after-instantiation errors and such. 2823 2824 return false; 2825} 2826 2827/// \brief Check the non-type template arguments of a class template 2828/// partial specialization according to C++ [temp.class.spec]p9. 2829/// 2830/// \param TemplateParams the template parameters of the primary class 2831/// template. 2832/// 2833/// \param TemplateArg the template arguments of the class template 2834/// partial specialization. 2835/// 2836/// \param MirrorsPrimaryTemplate will be set true if the class 2837/// template partial specialization arguments are identical to the 2838/// implicit template arguments of the primary template. This is not 2839/// necessarily an error (C++0x), and it is left to the caller to diagnose 2840/// this condition when it is an error. 2841/// 2842/// \returns true if there was an error, false otherwise. 2843bool Sema::CheckClassTemplatePartialSpecializationArgs( 2844 TemplateParameterList *TemplateParams, 2845 const TemplateArgumentListBuilder &TemplateArgs, 2846 bool &MirrorsPrimaryTemplate) { 2847 // FIXME: the interface to this function will have to change to 2848 // accommodate variadic templates. 2849 MirrorsPrimaryTemplate = true; 2850 2851 const TemplateArgument *ArgList = TemplateArgs.getFlatArguments(); 2852 2853 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 2854 // Determine whether the template argument list of the partial 2855 // specialization is identical to the implicit argument list of 2856 // the primary template. The caller may need to diagnostic this as 2857 // an error per C++ [temp.class.spec]p9b3. 2858 if (MirrorsPrimaryTemplate) { 2859 if (TemplateTypeParmDecl *TTP 2860 = dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(I))) { 2861 if (Context.getCanonicalType(Context.getTypeDeclType(TTP)) != 2862 Context.getCanonicalType(ArgList[I].getAsType())) 2863 MirrorsPrimaryTemplate = false; 2864 } else if (TemplateTemplateParmDecl *TTP 2865 = dyn_cast<TemplateTemplateParmDecl>( 2866 TemplateParams->getParam(I))) { 2867 TemplateName Name = ArgList[I].getAsTemplate(); 2868 TemplateTemplateParmDecl *ArgDecl 2869 = dyn_cast_or_null<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()); 2870 if (!ArgDecl || 2871 ArgDecl->getIndex() != TTP->getIndex() || 2872 ArgDecl->getDepth() != TTP->getDepth()) 2873 MirrorsPrimaryTemplate = false; 2874 } 2875 } 2876 2877 NonTypeTemplateParmDecl *Param 2878 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I)); 2879 if (!Param) { 2880 continue; 2881 } 2882 2883 Expr *ArgExpr = ArgList[I].getAsExpr(); 2884 if (!ArgExpr) { 2885 MirrorsPrimaryTemplate = false; 2886 continue; 2887 } 2888 2889 // C++ [temp.class.spec]p8: 2890 // A non-type argument is non-specialized if it is the name of a 2891 // non-type parameter. All other non-type arguments are 2892 // specialized. 2893 // 2894 // Below, we check the two conditions that only apply to 2895 // specialized non-type arguments, so skip any non-specialized 2896 // arguments. 2897 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr)) 2898 if (NonTypeTemplateParmDecl *NTTP 2899 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl())) { 2900 if (MirrorsPrimaryTemplate && 2901 (Param->getIndex() != NTTP->getIndex() || 2902 Param->getDepth() != NTTP->getDepth())) 2903 MirrorsPrimaryTemplate = false; 2904 2905 continue; 2906 } 2907 2908 // C++ [temp.class.spec]p9: 2909 // Within the argument list of a class template partial 2910 // specialization, the following restrictions apply: 2911 // -- A partially specialized non-type argument expression 2912 // shall not involve a template parameter of the partial 2913 // specialization except when the argument expression is a 2914 // simple identifier. 2915 if (ArgExpr->isTypeDependent() || ArgExpr->isValueDependent()) { 2916 Diag(ArgExpr->getLocStart(), 2917 diag::err_dependent_non_type_arg_in_partial_spec) 2918 << ArgExpr->getSourceRange(); 2919 return true; 2920 } 2921 2922 // -- The type of a template parameter corresponding to a 2923 // specialized non-type argument shall not be dependent on a 2924 // parameter of the specialization. 2925 if (Param->getType()->isDependentType()) { 2926 Diag(ArgExpr->getLocStart(), 2927 diag::err_dependent_typed_non_type_arg_in_partial_spec) 2928 << Param->getType() 2929 << ArgExpr->getSourceRange(); 2930 Diag(Param->getLocation(), diag::note_template_param_here); 2931 return true; 2932 } 2933 2934 MirrorsPrimaryTemplate = false; 2935 } 2936 2937 return false; 2938} 2939 2940Sema::DeclResult 2941Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, 2942 TagUseKind TUK, 2943 SourceLocation KWLoc, 2944 const CXXScopeSpec &SS, 2945 TemplateTy TemplateD, 2946 SourceLocation TemplateNameLoc, 2947 SourceLocation LAngleLoc, 2948 ASTTemplateArgsPtr TemplateArgsIn, 2949 SourceLocation RAngleLoc, 2950 AttributeList *Attr, 2951 MultiTemplateParamsArg TemplateParameterLists) { 2952 assert(TUK != TUK_Reference && "References are not specializations"); 2953 2954 // Find the class template we're specializing 2955 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 2956 ClassTemplateDecl *ClassTemplate 2957 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl()); 2958 2959 if (!ClassTemplate) { 2960 Diag(TemplateNameLoc, diag::err_not_class_template_specialization) 2961 << (Name.getAsTemplateDecl() && 2962 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl())); 2963 return true; 2964 } 2965 2966 bool isExplicitSpecialization = false; 2967 bool isPartialSpecialization = false; 2968 2969 // Check the validity of the template headers that introduce this 2970 // template. 2971 // FIXME: We probably shouldn't complain about these headers for 2972 // friend declarations. 2973 TemplateParameterList *TemplateParams 2974 = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, SS, 2975 (TemplateParameterList**)TemplateParameterLists.get(), 2976 TemplateParameterLists.size(), 2977 isExplicitSpecialization); 2978 if (TemplateParams && TemplateParams->size() > 0) { 2979 isPartialSpecialization = true; 2980 2981 // C++ [temp.class.spec]p10: 2982 // The template parameter list of a specialization shall not 2983 // contain default template argument values. 2984 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 2985 Decl *Param = TemplateParams->getParam(I); 2986 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) { 2987 if (TTP->hasDefaultArgument()) { 2988 Diag(TTP->getDefaultArgumentLoc(), 2989 diag::err_default_arg_in_partial_spec); 2990 TTP->removeDefaultArgument(); 2991 } 2992 } else if (NonTypeTemplateParmDecl *NTTP 2993 = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2994 if (Expr *DefArg = NTTP->getDefaultArgument()) { 2995 Diag(NTTP->getDefaultArgumentLoc(), 2996 diag::err_default_arg_in_partial_spec) 2997 << DefArg->getSourceRange(); 2998 NTTP->setDefaultArgument(0); 2999 DefArg->Destroy(Context); 3000 } 3001 } else { 3002 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param); 3003 if (TTP->hasDefaultArgument()) { 3004 Diag(TTP->getDefaultArgument().getLocation(), 3005 diag::err_default_arg_in_partial_spec) 3006 << TTP->getDefaultArgument().getSourceRange(); 3007 TTP->setDefaultArgument(TemplateArgumentLoc()); 3008 } 3009 } 3010 } 3011 } else if (TemplateParams) { 3012 if (TUK == TUK_Friend) 3013 Diag(KWLoc, diag::err_template_spec_friend) 3014 << CodeModificationHint::CreateRemoval( 3015 SourceRange(TemplateParams->getTemplateLoc(), 3016 TemplateParams->getRAngleLoc())) 3017 << SourceRange(LAngleLoc, RAngleLoc); 3018 else 3019 isExplicitSpecialization = true; 3020 } else if (TUK != TUK_Friend) { 3021 Diag(KWLoc, diag::err_template_spec_needs_header) 3022 << CodeModificationHint::CreateInsertion(KWLoc, "template<> "); 3023 isExplicitSpecialization = true; 3024 } 3025 3026 // Check that the specialization uses the same tag kind as the 3027 // original template. 3028 TagDecl::TagKind Kind; 3029 switch (TagSpec) { 3030 default: assert(0 && "Unknown tag type!"); 3031 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3032 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3033 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3034 } 3035 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 3036 Kind, KWLoc, 3037 *ClassTemplate->getIdentifier())) { 3038 Diag(KWLoc, diag::err_use_with_wrong_tag) 3039 << ClassTemplate 3040 << CodeModificationHint::CreateReplacement(KWLoc, 3041 ClassTemplate->getTemplatedDecl()->getKindName()); 3042 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 3043 diag::note_previous_use); 3044 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 3045 } 3046 3047 // Translate the parser's template argument list in our AST format. 3048 llvm::SmallVector<TemplateArgumentLoc, 16> TemplateArgs; 3049 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 3050 3051 // Check that the template argument list is well-formed for this 3052 // template. 3053 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 3054 TemplateArgs.size()); 3055 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, LAngleLoc, 3056 TemplateArgs.data(), TemplateArgs.size(), 3057 RAngleLoc, false, Converted)) 3058 return true; 3059 3060 assert((Converted.structuredSize() == 3061 ClassTemplate->getTemplateParameters()->size()) && 3062 "Converted template argument list is too short!"); 3063 3064 // Find the class template (partial) specialization declaration that 3065 // corresponds to these arguments. 3066 llvm::FoldingSetNodeID ID; 3067 if (isPartialSpecialization) { 3068 bool MirrorsPrimaryTemplate; 3069 if (CheckClassTemplatePartialSpecializationArgs( 3070 ClassTemplate->getTemplateParameters(), 3071 Converted, MirrorsPrimaryTemplate)) 3072 return true; 3073 3074 if (MirrorsPrimaryTemplate) { 3075 // C++ [temp.class.spec]p9b3: 3076 // 3077 // -- The argument list of the specialization shall not be identical 3078 // to the implicit argument list of the primary template. 3079 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) 3080 << (TUK == TUK_Definition) 3081 << CodeModificationHint::CreateRemoval(SourceRange(LAngleLoc, 3082 RAngleLoc)); 3083 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS, 3084 ClassTemplate->getIdentifier(), 3085 TemplateNameLoc, 3086 Attr, 3087 TemplateParams, 3088 AS_none); 3089 } 3090 3091 // FIXME: Diagnose friend partial specializations 3092 3093 // FIXME: Template parameter list matters, too 3094 ClassTemplatePartialSpecializationDecl::Profile(ID, 3095 Converted.getFlatArguments(), 3096 Converted.flatSize(), 3097 Context); 3098 } else 3099 ClassTemplateSpecializationDecl::Profile(ID, 3100 Converted.getFlatArguments(), 3101 Converted.flatSize(), 3102 Context); 3103 void *InsertPos = 0; 3104 ClassTemplateSpecializationDecl *PrevDecl = 0; 3105 3106 if (isPartialSpecialization) 3107 PrevDecl 3108 = ClassTemplate->getPartialSpecializations().FindNodeOrInsertPos(ID, 3109 InsertPos); 3110 else 3111 PrevDecl 3112 = ClassTemplate->getSpecializations().FindNodeOrInsertPos(ID, InsertPos); 3113 3114 ClassTemplateSpecializationDecl *Specialization = 0; 3115 3116 // Check whether we can declare a class template specialization in 3117 // the current scope. 3118 if (TUK != TUK_Friend && 3119 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl, 3120 TemplateNameLoc, 3121 isPartialSpecialization)) 3122 return true; 3123 3124 // The canonical type 3125 QualType CanonType; 3126 if (PrevDecl && 3127 (PrevDecl->getSpecializationKind() == TSK_Undeclared || 3128 TUK == TUK_Friend)) { 3129 // Since the only prior class template specialization with these 3130 // arguments was referenced but not declared, or we're only 3131 // referencing this specialization as a friend, reuse that 3132 // declaration node as our own, updating its source location to 3133 // reflect our new declaration. 3134 Specialization = PrevDecl; 3135 Specialization->setLocation(TemplateNameLoc); 3136 PrevDecl = 0; 3137 CanonType = Context.getTypeDeclType(Specialization); 3138 } else if (isPartialSpecialization) { 3139 // Build the canonical type that describes the converted template 3140 // arguments of the class template partial specialization. 3141 CanonType = Context.getTemplateSpecializationType( 3142 TemplateName(ClassTemplate), 3143 Converted.getFlatArguments(), 3144 Converted.flatSize()); 3145 3146 // Create a new class template partial specialization declaration node. 3147 ClassTemplatePartialSpecializationDecl *PrevPartial 3148 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl); 3149 ClassTemplatePartialSpecializationDecl *Partial 3150 = ClassTemplatePartialSpecializationDecl::Create(Context, 3151 ClassTemplate->getDeclContext(), 3152 TemplateNameLoc, 3153 TemplateParams, 3154 ClassTemplate, 3155 Converted, 3156 TemplateArgs.data(), 3157 TemplateArgs.size(), 3158 PrevPartial); 3159 3160 if (PrevPartial) { 3161 ClassTemplate->getPartialSpecializations().RemoveNode(PrevPartial); 3162 ClassTemplate->getPartialSpecializations().GetOrInsertNode(Partial); 3163 } else { 3164 ClassTemplate->getPartialSpecializations().InsertNode(Partial, InsertPos); 3165 } 3166 Specialization = Partial; 3167 3168 // If we are providing an explicit specialization of a member class 3169 // template specialization, make a note of that. 3170 if (PrevPartial && PrevPartial->getInstantiatedFromMember()) 3171 PrevPartial->setMemberSpecialization(); 3172 3173 // Check that all of the template parameters of the class template 3174 // partial specialization are deducible from the template 3175 // arguments. If not, this class template partial specialization 3176 // will never be used. 3177 llvm::SmallVector<bool, 8> DeducibleParams; 3178 DeducibleParams.resize(TemplateParams->size()); 3179 MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, 3180 TemplateParams->getDepth(), 3181 DeducibleParams); 3182 unsigned NumNonDeducible = 0; 3183 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) 3184 if (!DeducibleParams[I]) 3185 ++NumNonDeducible; 3186 3187 if (NumNonDeducible) { 3188 Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) 3189 << (NumNonDeducible > 1) 3190 << SourceRange(TemplateNameLoc, RAngleLoc); 3191 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { 3192 if (!DeducibleParams[I]) { 3193 NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I)); 3194 if (Param->getDeclName()) 3195 Diag(Param->getLocation(), 3196 diag::note_partial_spec_unused_parameter) 3197 << Param->getDeclName(); 3198 else 3199 Diag(Param->getLocation(), 3200 diag::note_partial_spec_unused_parameter) 3201 << std::string("<anonymous>"); 3202 } 3203 } 3204 } 3205 } else { 3206 // Create a new class template specialization declaration node for 3207 // this explicit specialization or friend declaration. 3208 Specialization 3209 = ClassTemplateSpecializationDecl::Create(Context, 3210 ClassTemplate->getDeclContext(), 3211 TemplateNameLoc, 3212 ClassTemplate, 3213 Converted, 3214 PrevDecl); 3215 3216 if (PrevDecl) { 3217 ClassTemplate->getSpecializations().RemoveNode(PrevDecl); 3218 ClassTemplate->getSpecializations().GetOrInsertNode(Specialization); 3219 } else { 3220 ClassTemplate->getSpecializations().InsertNode(Specialization, 3221 InsertPos); 3222 } 3223 3224 CanonType = Context.getTypeDeclType(Specialization); 3225 } 3226 3227 // C++ [temp.expl.spec]p6: 3228 // If a template, a member template or the member of a class template is 3229 // explicitly specialized then that specialization shall be declared 3230 // before the first use of that specialization that would cause an implicit 3231 // instantiation to take place, in every translation unit in which such a 3232 // use occurs; no diagnostic is required. 3233 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { 3234 SourceRange Range(TemplateNameLoc, RAngleLoc); 3235 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) 3236 << Context.getTypeDeclType(Specialization) << Range; 3237 3238 Diag(PrevDecl->getPointOfInstantiation(), 3239 diag::note_instantiation_required_here) 3240 << (PrevDecl->getTemplateSpecializationKind() 3241 != TSK_ImplicitInstantiation); 3242 return true; 3243 } 3244 3245 // If this is not a friend, note that this is an explicit specialization. 3246 if (TUK != TUK_Friend) 3247 Specialization->setSpecializationKind(TSK_ExplicitSpecialization); 3248 3249 // Check that this isn't a redefinition of this specialization. 3250 if (TUK == TUK_Definition) { 3251 if (RecordDecl *Def = Specialization->getDefinition(Context)) { 3252 SourceRange Range(TemplateNameLoc, RAngleLoc); 3253 Diag(TemplateNameLoc, diag::err_redefinition) 3254 << Context.getTypeDeclType(Specialization) << Range; 3255 Diag(Def->getLocation(), diag::note_previous_definition); 3256 Specialization->setInvalidDecl(); 3257 return true; 3258 } 3259 } 3260 3261 // Build the fully-sugared type for this class template 3262 // specialization as the user wrote in the specialization 3263 // itself. This means that we'll pretty-print the type retrieved 3264 // from the specialization's declaration the way that the user 3265 // actually wrote the specialization, rather than formatting the 3266 // name based on the "canonical" representation used to store the 3267 // template arguments in the specialization. 3268 QualType WrittenTy 3269 = Context.getTemplateSpecializationType(Name, 3270 TemplateArgs.data(), 3271 TemplateArgs.size(), 3272 CanonType); 3273 if (TUK != TUK_Friend) 3274 Specialization->setTypeAsWritten(WrittenTy); 3275 TemplateArgsIn.release(); 3276 3277 // C++ [temp.expl.spec]p9: 3278 // A template explicit specialization is in the scope of the 3279 // namespace in which the template was defined. 3280 // 3281 // We actually implement this paragraph where we set the semantic 3282 // context (in the creation of the ClassTemplateSpecializationDecl), 3283 // but we also maintain the lexical context where the actual 3284 // definition occurs. 3285 Specialization->setLexicalDeclContext(CurContext); 3286 3287 // We may be starting the definition of this specialization. 3288 if (TUK == TUK_Definition) 3289 Specialization->startDefinition(); 3290 3291 if (TUK == TUK_Friend) { 3292 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, 3293 TemplateNameLoc, 3294 WrittenTy.getTypePtr(), 3295 /*FIXME:*/KWLoc); 3296 Friend->setAccess(AS_public); 3297 CurContext->addDecl(Friend); 3298 } else { 3299 // Add the specialization into its lexical context, so that it can 3300 // be seen when iterating through the list of declarations in that 3301 // context. However, specializations are not found by name lookup. 3302 CurContext->addDecl(Specialization); 3303 } 3304 return DeclPtrTy::make(Specialization); 3305} 3306 3307Sema::DeclPtrTy 3308Sema::ActOnTemplateDeclarator(Scope *S, 3309 MultiTemplateParamsArg TemplateParameterLists, 3310 Declarator &D) { 3311 return HandleDeclarator(S, D, move(TemplateParameterLists), false); 3312} 3313 3314Sema::DeclPtrTy 3315Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope, 3316 MultiTemplateParamsArg TemplateParameterLists, 3317 Declarator &D) { 3318 assert(getCurFunctionDecl() == 0 && "Function parsing confused"); 3319 assert(D.getTypeObject(0).Kind == DeclaratorChunk::Function && 3320 "Not a function declarator!"); 3321 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 3322 3323 if (FTI.hasPrototype) { 3324 // FIXME: Diagnose arguments without names in C. 3325 } 3326 3327 Scope *ParentScope = FnBodyScope->getParent(); 3328 3329 DeclPtrTy DP = HandleDeclarator(ParentScope, D, 3330 move(TemplateParameterLists), 3331 /*IsFunctionDefinition=*/true); 3332 if (FunctionTemplateDecl *FunctionTemplate 3333 = dyn_cast_or_null<FunctionTemplateDecl>(DP.getAs<Decl>())) 3334 return ActOnStartOfFunctionDef(FnBodyScope, 3335 DeclPtrTy::make(FunctionTemplate->getTemplatedDecl())); 3336 if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(DP.getAs<Decl>())) 3337 return ActOnStartOfFunctionDef(FnBodyScope, DeclPtrTy::make(Function)); 3338 return DeclPtrTy(); 3339} 3340 3341/// \brief Diagnose cases where we have an explicit template specialization 3342/// before/after an explicit template instantiation, producing diagnostics 3343/// for those cases where they are required and determining whether the 3344/// new specialization/instantiation will have any effect. 3345/// 3346/// \param NewLoc the location of the new explicit specialization or 3347/// instantiation. 3348/// 3349/// \param NewTSK the kind of the new explicit specialization or instantiation. 3350/// 3351/// \param PrevDecl the previous declaration of the entity. 3352/// 3353/// \param PrevTSK the kind of the old explicit specialization or instantiatin. 3354/// 3355/// \param PrevPointOfInstantiation if valid, indicates where the previus 3356/// declaration was instantiated (either implicitly or explicitly). 3357/// 3358/// \param SuppressNew will be set to true to indicate that the new 3359/// specialization or instantiation has no effect and should be ignored. 3360/// 3361/// \returns true if there was an error that should prevent the introduction of 3362/// the new declaration into the AST, false otherwise. 3363bool 3364Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc, 3365 TemplateSpecializationKind NewTSK, 3366 NamedDecl *PrevDecl, 3367 TemplateSpecializationKind PrevTSK, 3368 SourceLocation PrevPointOfInstantiation, 3369 bool &SuppressNew) { 3370 SuppressNew = false; 3371 3372 switch (NewTSK) { 3373 case TSK_Undeclared: 3374 case TSK_ImplicitInstantiation: 3375 assert(false && "Don't check implicit instantiations here"); 3376 return false; 3377 3378 case TSK_ExplicitSpecialization: 3379 switch (PrevTSK) { 3380 case TSK_Undeclared: 3381 case TSK_ExplicitSpecialization: 3382 // Okay, we're just specializing something that is either already 3383 // explicitly specialized or has merely been mentioned without any 3384 // instantiation. 3385 return false; 3386 3387 case TSK_ImplicitInstantiation: 3388 if (PrevPointOfInstantiation.isInvalid()) { 3389 // The declaration itself has not actually been instantiated, so it is 3390 // still okay to specialize it. 3391 return false; 3392 } 3393 // Fall through 3394 3395 case TSK_ExplicitInstantiationDeclaration: 3396 case TSK_ExplicitInstantiationDefinition: 3397 assert((PrevTSK == TSK_ImplicitInstantiation || 3398 PrevPointOfInstantiation.isValid()) && 3399 "Explicit instantiation without point of instantiation?"); 3400 3401 // C++ [temp.expl.spec]p6: 3402 // If a template, a member template or the member of a class template 3403 // is explicitly specialized then that specialization shall be declared 3404 // before the first use of that specialization that would cause an 3405 // implicit instantiation to take place, in every translation unit in 3406 // which such a use occurs; no diagnostic is required. 3407 Diag(NewLoc, diag::err_specialization_after_instantiation) 3408 << PrevDecl; 3409 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here) 3410 << (PrevTSK != TSK_ImplicitInstantiation); 3411 3412 return true; 3413 } 3414 break; 3415 3416 case TSK_ExplicitInstantiationDeclaration: 3417 switch (PrevTSK) { 3418 case TSK_ExplicitInstantiationDeclaration: 3419 // This explicit instantiation declaration is redundant (that's okay). 3420 SuppressNew = true; 3421 return false; 3422 3423 case TSK_Undeclared: 3424 case TSK_ImplicitInstantiation: 3425 // We're explicitly instantiating something that may have already been 3426 // implicitly instantiated; that's fine. 3427 return false; 3428 3429 case TSK_ExplicitSpecialization: 3430 // C++0x [temp.explicit]p4: 3431 // For a given set of template parameters, if an explicit instantiation 3432 // of a template appears after a declaration of an explicit 3433 // specialization for that template, the explicit instantiation has no 3434 // effect. 3435 return false; 3436 3437 case TSK_ExplicitInstantiationDefinition: 3438 // C++0x [temp.explicit]p10: 3439 // If an entity is the subject of both an explicit instantiation 3440 // declaration and an explicit instantiation definition in the same 3441 // translation unit, the definition shall follow the declaration. 3442 Diag(NewLoc, 3443 diag::err_explicit_instantiation_declaration_after_definition); 3444 Diag(PrevPointOfInstantiation, 3445 diag::note_explicit_instantiation_definition_here); 3446 assert(PrevPointOfInstantiation.isValid() && 3447 "Explicit instantiation without point of instantiation?"); 3448 SuppressNew = true; 3449 return false; 3450 } 3451 break; 3452 3453 case TSK_ExplicitInstantiationDefinition: 3454 switch (PrevTSK) { 3455 case TSK_Undeclared: 3456 case TSK_ImplicitInstantiation: 3457 // We're explicitly instantiating something that may have already been 3458 // implicitly instantiated; that's fine. 3459 return false; 3460 3461 case TSK_ExplicitSpecialization: 3462 // C++ DR 259, C++0x [temp.explicit]p4: 3463 // For a given set of template parameters, if an explicit 3464 // instantiation of a template appears after a declaration of 3465 // an explicit specialization for that template, the explicit 3466 // instantiation has no effect. 3467 // 3468 // In C++98/03 mode, we only give an extension warning here, because it 3469 // is not not harmful to try to explicitly instantiate something that 3470 // has been explicitly specialized. 3471 if (!getLangOptions().CPlusPlus0x) { 3472 Diag(NewLoc, diag::ext_explicit_instantiation_after_specialization) 3473 << PrevDecl; 3474 Diag(PrevDecl->getLocation(), 3475 diag::note_previous_template_specialization); 3476 } 3477 SuppressNew = true; 3478 return false; 3479 3480 case TSK_ExplicitInstantiationDeclaration: 3481 // We're explicity instantiating a definition for something for which we 3482 // were previously asked to suppress instantiations. That's fine. 3483 return false; 3484 3485 case TSK_ExplicitInstantiationDefinition: 3486 // C++0x [temp.spec]p5: 3487 // For a given template and a given set of template-arguments, 3488 // - an explicit instantiation definition shall appear at most once 3489 // in a program, 3490 Diag(NewLoc, diag::err_explicit_instantiation_duplicate) 3491 << PrevDecl; 3492 Diag(PrevPointOfInstantiation, 3493 diag::note_previous_explicit_instantiation); 3494 SuppressNew = true; 3495 return false; 3496 } 3497 break; 3498 } 3499 3500 assert(false && "Missing specialization/instantiation case?"); 3501 3502 return false; 3503} 3504 3505/// \brief Perform semantic analysis for the given function template 3506/// specialization. 3507/// 3508/// This routine performs all of the semantic analysis required for an 3509/// explicit function template specialization. On successful completion, 3510/// the function declaration \p FD will become a function template 3511/// specialization. 3512/// 3513/// \param FD the function declaration, which will be updated to become a 3514/// function template specialization. 3515/// 3516/// \param HasExplicitTemplateArgs whether any template arguments were 3517/// explicitly provided. 3518/// 3519/// \param LAngleLoc the location of the left angle bracket ('<'), if 3520/// template arguments were explicitly provided. 3521/// 3522/// \param ExplicitTemplateArgs the explicitly-provided template arguments, 3523/// if any. 3524/// 3525/// \param NumExplicitTemplateArgs the number of explicitly-provided template 3526/// arguments. This number may be zero even when HasExplicitTemplateArgs is 3527/// true as in, e.g., \c void sort<>(char*, char*); 3528/// 3529/// \param RAngleLoc the location of the right angle bracket ('>'), if 3530/// template arguments were explicitly provided. 3531/// 3532/// \param PrevDecl the set of declarations that 3533bool 3534Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD, 3535 bool HasExplicitTemplateArgs, 3536 SourceLocation LAngleLoc, 3537 const TemplateArgumentLoc *ExplicitTemplateArgs, 3538 unsigned NumExplicitTemplateArgs, 3539 SourceLocation RAngleLoc, 3540 NamedDecl *&PrevDecl) { 3541 // The set of function template specializations that could match this 3542 // explicit function template specialization. 3543 typedef llvm::SmallVector<FunctionDecl *, 8> CandidateSet; 3544 CandidateSet Candidates; 3545 3546 DeclContext *FDLookupContext = FD->getDeclContext()->getLookupContext(); 3547 for (OverloadIterator Ovl(PrevDecl), OvlEnd; Ovl != OvlEnd; ++Ovl) { 3548 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(*Ovl)) { 3549 // Only consider templates found within the same semantic lookup scope as 3550 // FD. 3551 if (!FDLookupContext->Equals(Ovl->getDeclContext()->getLookupContext())) 3552 continue; 3553 3554 // C++ [temp.expl.spec]p11: 3555 // A trailing template-argument can be left unspecified in the 3556 // template-id naming an explicit function template specialization 3557 // provided it can be deduced from the function argument type. 3558 // Perform template argument deduction to determine whether we may be 3559 // specializing this template. 3560 // FIXME: It is somewhat wasteful to build 3561 TemplateDeductionInfo Info(Context); 3562 FunctionDecl *Specialization = 0; 3563 if (TemplateDeductionResult TDK 3564 = DeduceTemplateArguments(FunTmpl, HasExplicitTemplateArgs, 3565 ExplicitTemplateArgs, 3566 NumExplicitTemplateArgs, 3567 FD->getType(), 3568 Specialization, 3569 Info)) { 3570 // FIXME: Template argument deduction failed; record why it failed, so 3571 // that we can provide nifty diagnostics. 3572 (void)TDK; 3573 continue; 3574 } 3575 3576 // Record this candidate. 3577 Candidates.push_back(Specialization); 3578 } 3579 } 3580 3581 // Find the most specialized function template. 3582 FunctionDecl *Specialization = getMostSpecialized(Candidates.data(), 3583 Candidates.size(), 3584 TPOC_Other, 3585 FD->getLocation(), 3586 PartialDiagnostic(diag::err_function_template_spec_no_match) 3587 << FD->getDeclName(), 3588 PartialDiagnostic(diag::err_function_template_spec_ambiguous) 3589 << FD->getDeclName() << HasExplicitTemplateArgs, 3590 PartialDiagnostic(diag::note_function_template_spec_matched)); 3591 if (!Specialization) 3592 return true; 3593 3594 // FIXME: Check if the prior specialization has a point of instantiation. 3595 // If so, we have run afoul of . 3596 3597 // Check the scope of this explicit specialization. 3598 if (CheckTemplateSpecializationScope(*this, 3599 Specialization->getPrimaryTemplate(), 3600 Specialization, FD->getLocation(), 3601 false)) 3602 return true; 3603 3604 // C++ [temp.expl.spec]p6: 3605 // If a template, a member template or the member of a class template is 3606 // explicitly specialized then that specialization shall be declared 3607 // before the first use of that specialization that would cause an implicit 3608 // instantiation to take place, in every translation unit in which such a 3609 // use occurs; no diagnostic is required. 3610 FunctionTemplateSpecializationInfo *SpecInfo 3611 = Specialization->getTemplateSpecializationInfo(); 3612 assert(SpecInfo && "Function template specialization info missing?"); 3613 if (SpecInfo->getPointOfInstantiation().isValid()) { 3614 Diag(FD->getLocation(), diag::err_specialization_after_instantiation) 3615 << FD; 3616 Diag(SpecInfo->getPointOfInstantiation(), 3617 diag::note_instantiation_required_here) 3618 << (Specialization->getTemplateSpecializationKind() 3619 != TSK_ImplicitInstantiation); 3620 return true; 3621 } 3622 3623 // Mark the prior declaration as an explicit specialization, so that later 3624 // clients know that this is an explicit specialization. 3625 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization); 3626 3627 // Turn the given function declaration into a function template 3628 // specialization, with the template arguments from the previous 3629 // specialization. 3630 FD->setFunctionTemplateSpecialization(Context, 3631 Specialization->getPrimaryTemplate(), 3632 new (Context) TemplateArgumentList( 3633 *Specialization->getTemplateSpecializationArgs()), 3634 /*InsertPos=*/0, 3635 TSK_ExplicitSpecialization); 3636 3637 // The "previous declaration" for this function template specialization is 3638 // the prior function template specialization. 3639 PrevDecl = Specialization; 3640 return false; 3641} 3642 3643/// \brief Perform semantic analysis for the given non-template member 3644/// specialization. 3645/// 3646/// This routine performs all of the semantic analysis required for an 3647/// explicit member function specialization. On successful completion, 3648/// the function declaration \p FD will become a member function 3649/// specialization. 3650/// 3651/// \param Member the member declaration, which will be updated to become a 3652/// specialization. 3653/// 3654/// \param PrevDecl the set of declarations, one of which may be specialized 3655/// by this function specialization. 3656bool 3657Sema::CheckMemberSpecialization(NamedDecl *Member, NamedDecl *&PrevDecl) { 3658 assert(!isa<TemplateDecl>(Member) && "Only for non-template members"); 3659 3660 // Try to find the member we are instantiating. 3661 NamedDecl *Instantiation = 0; 3662 NamedDecl *InstantiatedFrom = 0; 3663 MemberSpecializationInfo *MSInfo = 0; 3664 3665 if (!PrevDecl) { 3666 // Nowhere to look anyway. 3667 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) { 3668 for (OverloadIterator Ovl(PrevDecl), OvlEnd; Ovl != OvlEnd; ++Ovl) { 3669 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Ovl)) { 3670 if (Context.hasSameType(Function->getType(), Method->getType())) { 3671 Instantiation = Method; 3672 InstantiatedFrom = Method->getInstantiatedFromMemberFunction(); 3673 MSInfo = Method->getMemberSpecializationInfo(); 3674 break; 3675 } 3676 } 3677 } 3678 } else if (isa<VarDecl>(Member)) { 3679 if (VarDecl *PrevVar = dyn_cast<VarDecl>(PrevDecl)) 3680 if (PrevVar->isStaticDataMember()) { 3681 Instantiation = PrevDecl; 3682 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember(); 3683 MSInfo = PrevVar->getMemberSpecializationInfo(); 3684 } 3685 } else if (isa<RecordDecl>(Member)) { 3686 if (CXXRecordDecl *PrevRecord = dyn_cast<CXXRecordDecl>(PrevDecl)) { 3687 Instantiation = PrevDecl; 3688 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass(); 3689 MSInfo = PrevRecord->getMemberSpecializationInfo(); 3690 } 3691 } 3692 3693 if (!Instantiation) { 3694 // There is no previous declaration that matches. Since member 3695 // specializations are always out-of-line, the caller will complain about 3696 // this mismatch later. 3697 return false; 3698 } 3699 3700 // Make sure that this is a specialization of a member. 3701 if (!InstantiatedFrom) { 3702 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated) 3703 << Member; 3704 Diag(Instantiation->getLocation(), diag::note_specialized_decl); 3705 return true; 3706 } 3707 3708 // C++ [temp.expl.spec]p6: 3709 // If a template, a member template or the member of a class template is 3710 // explicitly specialized then that spe- cialization shall be declared 3711 // before the first use of that specialization that would cause an implicit 3712 // instantiation to take place, in every translation unit in which such a 3713 // use occurs; no diagnostic is required. 3714 assert(MSInfo && "Member specialization info missing?"); 3715 if (MSInfo->getPointOfInstantiation().isValid()) { 3716 Diag(Member->getLocation(), diag::err_specialization_after_instantiation) 3717 << Member; 3718 Diag(MSInfo->getPointOfInstantiation(), 3719 diag::note_instantiation_required_here) 3720 << (MSInfo->getTemplateSpecializationKind() != TSK_ImplicitInstantiation); 3721 return true; 3722 } 3723 3724 // Check the scope of this explicit specialization. 3725 if (CheckTemplateSpecializationScope(*this, 3726 InstantiatedFrom, 3727 Instantiation, Member->getLocation(), 3728 false)) 3729 return true; 3730 3731 // Note that this is an explicit instantiation of a member. 3732 // the original declaration to note that it is an explicit specialization 3733 // (if it was previously an implicit instantiation). This latter step 3734 // makes bookkeeping easier. 3735 if (isa<FunctionDecl>(Member)) { 3736 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation); 3737 if (InstantiationFunction->getTemplateSpecializationKind() == 3738 TSK_ImplicitInstantiation) { 3739 InstantiationFunction->setTemplateSpecializationKind( 3740 TSK_ExplicitSpecialization); 3741 InstantiationFunction->setLocation(Member->getLocation()); 3742 } 3743 3744 cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction( 3745 cast<CXXMethodDecl>(InstantiatedFrom), 3746 TSK_ExplicitSpecialization); 3747 } else if (isa<VarDecl>(Member)) { 3748 VarDecl *InstantiationVar = cast<VarDecl>(Instantiation); 3749 if (InstantiationVar->getTemplateSpecializationKind() == 3750 TSK_ImplicitInstantiation) { 3751 InstantiationVar->setTemplateSpecializationKind( 3752 TSK_ExplicitSpecialization); 3753 InstantiationVar->setLocation(Member->getLocation()); 3754 } 3755 3756 Context.setInstantiatedFromStaticDataMember(cast<VarDecl>(Member), 3757 cast<VarDecl>(InstantiatedFrom), 3758 TSK_ExplicitSpecialization); 3759 } else { 3760 assert(isa<CXXRecordDecl>(Member) && "Only member classes remain"); 3761 CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation); 3762 if (InstantiationClass->getTemplateSpecializationKind() == 3763 TSK_ImplicitInstantiation) { 3764 InstantiationClass->setTemplateSpecializationKind( 3765 TSK_ExplicitSpecialization); 3766 InstantiationClass->setLocation(Member->getLocation()); 3767 } 3768 3769 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass( 3770 cast<CXXRecordDecl>(InstantiatedFrom), 3771 TSK_ExplicitSpecialization); 3772 } 3773 3774 // Save the caller the trouble of having to figure out which declaration 3775 // this specialization matches. 3776 PrevDecl = Instantiation; 3777 return false; 3778} 3779 3780/// \brief Check the scope of an explicit instantiation. 3781static void CheckExplicitInstantiationScope(Sema &S, NamedDecl *D, 3782 SourceLocation InstLoc, 3783 bool WasQualifiedName) { 3784 DeclContext *ExpectedContext 3785 = D->getDeclContext()->getEnclosingNamespaceContext()->getLookupContext(); 3786 DeclContext *CurContext = S.CurContext->getLookupContext(); 3787 3788 // C++0x [temp.explicit]p2: 3789 // An explicit instantiation shall appear in an enclosing namespace of its 3790 // template. 3791 // 3792 // This is DR275, which we do not retroactively apply to C++98/03. 3793 if (S.getLangOptions().CPlusPlus0x && 3794 !CurContext->Encloses(ExpectedContext)) { 3795 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ExpectedContext)) 3796 S.Diag(InstLoc, diag::err_explicit_instantiation_out_of_scope) 3797 << D << NS; 3798 else 3799 S.Diag(InstLoc, diag::err_explicit_instantiation_must_be_global) 3800 << D; 3801 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 3802 return; 3803 } 3804 3805 // C++0x [temp.explicit]p2: 3806 // If the name declared in the explicit instantiation is an unqualified 3807 // name, the explicit instantiation shall appear in the namespace where 3808 // its template is declared or, if that namespace is inline (7.3.1), any 3809 // namespace from its enclosing namespace set. 3810 if (WasQualifiedName) 3811 return; 3812 3813 if (CurContext->Equals(ExpectedContext)) 3814 return; 3815 3816 S.Diag(InstLoc, diag::err_explicit_instantiation_unqualified_wrong_namespace) 3817 << D << ExpectedContext; 3818 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here); 3819} 3820 3821/// \brief Determine whether the given scope specifier has a template-id in it. 3822static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) { 3823 if (!SS.isSet()) 3824 return false; 3825 3826 // C++0x [temp.explicit]p2: 3827 // If the explicit instantiation is for a member function, a member class 3828 // or a static data member of a class template specialization, the name of 3829 // the class template specialization in the qualified-id for the member 3830 // name shall be a simple-template-id. 3831 // 3832 // C++98 has the same restriction, just worded differently. 3833 for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 3834 NNS; NNS = NNS->getPrefix()) 3835 if (Type *T = NNS->getAsType()) 3836 if (isa<TemplateSpecializationType>(T)) 3837 return true; 3838 3839 return false; 3840} 3841 3842// Explicit instantiation of a class template specialization 3843// FIXME: Implement extern template semantics 3844Sema::DeclResult 3845Sema::ActOnExplicitInstantiation(Scope *S, 3846 SourceLocation ExternLoc, 3847 SourceLocation TemplateLoc, 3848 unsigned TagSpec, 3849 SourceLocation KWLoc, 3850 const CXXScopeSpec &SS, 3851 TemplateTy TemplateD, 3852 SourceLocation TemplateNameLoc, 3853 SourceLocation LAngleLoc, 3854 ASTTemplateArgsPtr TemplateArgsIn, 3855 SourceLocation RAngleLoc, 3856 AttributeList *Attr) { 3857 // Find the class template we're specializing 3858 TemplateName Name = TemplateD.getAsVal<TemplateName>(); 3859 ClassTemplateDecl *ClassTemplate 3860 = cast<ClassTemplateDecl>(Name.getAsTemplateDecl()); 3861 3862 // Check that the specialization uses the same tag kind as the 3863 // original template. 3864 TagDecl::TagKind Kind; 3865 switch (TagSpec) { 3866 default: assert(0 && "Unknown tag type!"); 3867 case DeclSpec::TST_struct: Kind = TagDecl::TK_struct; break; 3868 case DeclSpec::TST_union: Kind = TagDecl::TK_union; break; 3869 case DeclSpec::TST_class: Kind = TagDecl::TK_class; break; 3870 } 3871 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(), 3872 Kind, KWLoc, 3873 *ClassTemplate->getIdentifier())) { 3874 Diag(KWLoc, diag::err_use_with_wrong_tag) 3875 << ClassTemplate 3876 << CodeModificationHint::CreateReplacement(KWLoc, 3877 ClassTemplate->getTemplatedDecl()->getKindName()); 3878 Diag(ClassTemplate->getTemplatedDecl()->getLocation(), 3879 diag::note_previous_use); 3880 Kind = ClassTemplate->getTemplatedDecl()->getTagKind(); 3881 } 3882 3883 // C++0x [temp.explicit]p2: 3884 // There are two forms of explicit instantiation: an explicit instantiation 3885 // definition and an explicit instantiation declaration. An explicit 3886 // instantiation declaration begins with the extern keyword. [...] 3887 TemplateSpecializationKind TSK 3888 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 3889 : TSK_ExplicitInstantiationDeclaration; 3890 3891 // Translate the parser's template argument list in our AST format. 3892 llvm::SmallVector<TemplateArgumentLoc, 16> TemplateArgs; 3893 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 3894 3895 // Check that the template argument list is well-formed for this 3896 // template. 3897 TemplateArgumentListBuilder Converted(ClassTemplate->getTemplateParameters(), 3898 TemplateArgs.size()); 3899 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc, LAngleLoc, 3900 TemplateArgs.data(), TemplateArgs.size(), 3901 RAngleLoc, false, Converted)) 3902 return true; 3903 3904 assert((Converted.structuredSize() == 3905 ClassTemplate->getTemplateParameters()->size()) && 3906 "Converted template argument list is too short!"); 3907 3908 // Find the class template specialization declaration that 3909 // corresponds to these arguments. 3910 llvm::FoldingSetNodeID ID; 3911 ClassTemplateSpecializationDecl::Profile(ID, 3912 Converted.getFlatArguments(), 3913 Converted.flatSize(), 3914 Context); 3915 void *InsertPos = 0; 3916 ClassTemplateSpecializationDecl *PrevDecl 3917 = ClassTemplate->getSpecializations().FindNodeOrInsertPos(ID, InsertPos); 3918 3919 // C++0x [temp.explicit]p2: 3920 // [...] An explicit instantiation shall appear in an enclosing 3921 // namespace of its template. [...] 3922 // 3923 // This is C++ DR 275. 3924 CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc, 3925 SS.isSet()); 3926 3927 ClassTemplateSpecializationDecl *Specialization = 0; 3928 3929 if (PrevDecl) { 3930 bool SuppressNew = false; 3931 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK, 3932 PrevDecl, 3933 PrevDecl->getSpecializationKind(), 3934 PrevDecl->getPointOfInstantiation(), 3935 SuppressNew)) 3936 return DeclPtrTy::make(PrevDecl); 3937 3938 if (SuppressNew) 3939 return DeclPtrTy::make(PrevDecl); 3940 3941 if (PrevDecl->getSpecializationKind() == TSK_ImplicitInstantiation || 3942 PrevDecl->getSpecializationKind() == TSK_Undeclared) { 3943 // Since the only prior class template specialization with these 3944 // arguments was referenced but not declared, reuse that 3945 // declaration node as our own, updating its source location to 3946 // reflect our new declaration. 3947 Specialization = PrevDecl; 3948 Specialization->setLocation(TemplateNameLoc); 3949 PrevDecl = 0; 3950 } 3951 } 3952 3953 if (!Specialization) { 3954 // Create a new class template specialization declaration node for 3955 // this explicit specialization. 3956 Specialization 3957 = ClassTemplateSpecializationDecl::Create(Context, 3958 ClassTemplate->getDeclContext(), 3959 TemplateNameLoc, 3960 ClassTemplate, 3961 Converted, PrevDecl); 3962 3963 if (PrevDecl) { 3964 // Remove the previous declaration from the folding set, since we want 3965 // to introduce a new declaration. 3966 ClassTemplate->getSpecializations().RemoveNode(PrevDecl); 3967 ClassTemplate->getSpecializations().FindNodeOrInsertPos(ID, InsertPos); 3968 } 3969 3970 // Insert the new specialization. 3971 ClassTemplate->getSpecializations().InsertNode(Specialization, InsertPos); 3972 } 3973 3974 // Build the fully-sugared type for this explicit instantiation as 3975 // the user wrote in the explicit instantiation itself. This means 3976 // that we'll pretty-print the type retrieved from the 3977 // specialization's declaration the way that the user actually wrote 3978 // the explicit instantiation, rather than formatting the name based 3979 // on the "canonical" representation used to store the template 3980 // arguments in the specialization. 3981 QualType WrittenTy 3982 = Context.getTemplateSpecializationType(Name, 3983 TemplateArgs.data(), 3984 TemplateArgs.size(), 3985 Context.getTypeDeclType(Specialization)); 3986 Specialization->setTypeAsWritten(WrittenTy); 3987 TemplateArgsIn.release(); 3988 3989 // Add the explicit instantiation into its lexical context. However, 3990 // since explicit instantiations are never found by name lookup, we 3991 // just put it into the declaration context directly. 3992 Specialization->setLexicalDeclContext(CurContext); 3993 CurContext->addDecl(Specialization); 3994 3995 // C++ [temp.explicit]p3: 3996 // A definition of a class template or class member template 3997 // shall be in scope at the point of the explicit instantiation of 3998 // the class template or class member template. 3999 // 4000 // This check comes when we actually try to perform the 4001 // instantiation. 4002 ClassTemplateSpecializationDecl *Def 4003 = cast_or_null<ClassTemplateSpecializationDecl>( 4004 Specialization->getDefinition(Context)); 4005 if (!Def) 4006 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK); 4007 4008 // Instantiate the members of this class template specialization. 4009 Def = cast_or_null<ClassTemplateSpecializationDecl>( 4010 Specialization->getDefinition(Context)); 4011 if (Def) 4012 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK); 4013 4014 return DeclPtrTy::make(Specialization); 4015} 4016 4017// Explicit instantiation of a member class of a class template. 4018Sema::DeclResult 4019Sema::ActOnExplicitInstantiation(Scope *S, 4020 SourceLocation ExternLoc, 4021 SourceLocation TemplateLoc, 4022 unsigned TagSpec, 4023 SourceLocation KWLoc, 4024 const CXXScopeSpec &SS, 4025 IdentifierInfo *Name, 4026 SourceLocation NameLoc, 4027 AttributeList *Attr) { 4028 4029 bool Owned = false; 4030 bool IsDependent = false; 4031 DeclPtrTy TagD = ActOnTag(S, TagSpec, Action::TUK_Reference, 4032 KWLoc, SS, Name, NameLoc, Attr, AS_none, 4033 MultiTemplateParamsArg(*this, 0, 0), 4034 Owned, IsDependent); 4035 assert(!IsDependent && "explicit instantiation of dependent name not yet handled"); 4036 4037 if (!TagD) 4038 return true; 4039 4040 TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>()); 4041 if (Tag->isEnum()) { 4042 Diag(TemplateLoc, diag::err_explicit_instantiation_enum) 4043 << Context.getTypeDeclType(Tag); 4044 return true; 4045 } 4046 4047 if (Tag->isInvalidDecl()) 4048 return true; 4049 4050 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag); 4051 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass(); 4052 if (!Pattern) { 4053 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type) 4054 << Context.getTypeDeclType(Record); 4055 Diag(Record->getLocation(), diag::note_nontemplate_decl_here); 4056 return true; 4057 } 4058 4059 // C++0x [temp.explicit]p2: 4060 // If the explicit instantiation is for a class or member class, the 4061 // elaborated-type-specifier in the declaration shall include a 4062 // simple-template-id. 4063 // 4064 // C++98 has the same restriction, just worded differently. 4065 if (!ScopeSpecifierHasTemplateId(SS)) 4066 Diag(TemplateLoc, diag::err_explicit_instantiation_without_qualified_id) 4067 << Record << SS.getRange(); 4068 4069 // C++0x [temp.explicit]p2: 4070 // There are two forms of explicit instantiation: an explicit instantiation 4071 // definition and an explicit instantiation declaration. An explicit 4072 // instantiation declaration begins with the extern keyword. [...] 4073 TemplateSpecializationKind TSK 4074 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4075 : TSK_ExplicitInstantiationDeclaration; 4076 4077 // C++0x [temp.explicit]p2: 4078 // [...] An explicit instantiation shall appear in an enclosing 4079 // namespace of its template. [...] 4080 // 4081 // This is C++ DR 275. 4082 CheckExplicitInstantiationScope(*this, Record, NameLoc, true); 4083 4084 // Verify that it is okay to explicitly instantiate here. 4085 CXXRecordDecl *PrevDecl 4086 = cast_or_null<CXXRecordDecl>(Record->getPreviousDeclaration()); 4087 if (!PrevDecl && Record->getDefinition(Context)) 4088 PrevDecl = Record; 4089 if (PrevDecl) { 4090 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo(); 4091 bool SuppressNew = false; 4092 assert(MSInfo && "No member specialization information?"); 4093 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK, 4094 PrevDecl, 4095 MSInfo->getTemplateSpecializationKind(), 4096 MSInfo->getPointOfInstantiation(), 4097 SuppressNew)) 4098 return true; 4099 if (SuppressNew) 4100 return TagD; 4101 } 4102 4103 CXXRecordDecl *RecordDef 4104 = cast_or_null<CXXRecordDecl>(Record->getDefinition(Context)); 4105 if (!RecordDef) { 4106 // C++ [temp.explicit]p3: 4107 // A definition of a member class of a class template shall be in scope 4108 // at the point of an explicit instantiation of the member class. 4109 CXXRecordDecl *Def 4110 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition(Context)); 4111 if (!Def) { 4112 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member) 4113 << 0 << Record->getDeclName() << Record->getDeclContext(); 4114 Diag(Pattern->getLocation(), diag::note_forward_declaration) 4115 << Pattern; 4116 return true; 4117 } else { 4118 if (InstantiateClass(NameLoc, Record, Def, 4119 getTemplateInstantiationArgs(Record), 4120 TSK)) 4121 return true; 4122 4123 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition(Context)); 4124 if (!RecordDef) 4125 return true; 4126 } 4127 } 4128 4129 // Instantiate all of the members of the class. 4130 InstantiateClassMembers(NameLoc, RecordDef, 4131 getTemplateInstantiationArgs(Record), TSK); 4132 4133 // FIXME: We don't have any representation for explicit instantiations of 4134 // member classes. Such a representation is not needed for compilation, but it 4135 // should be available for clients that want to see all of the declarations in 4136 // the source code. 4137 return TagD; 4138} 4139 4140Sema::DeclResult Sema::ActOnExplicitInstantiation(Scope *S, 4141 SourceLocation ExternLoc, 4142 SourceLocation TemplateLoc, 4143 Declarator &D) { 4144 // Explicit instantiations always require a name. 4145 DeclarationName Name = GetNameForDeclarator(D); 4146 if (!Name) { 4147 if (!D.isInvalidType()) 4148 Diag(D.getDeclSpec().getSourceRange().getBegin(), 4149 diag::err_explicit_instantiation_requires_name) 4150 << D.getDeclSpec().getSourceRange() 4151 << D.getSourceRange(); 4152 4153 return true; 4154 } 4155 4156 // The scope passed in may not be a decl scope. Zip up the scope tree until 4157 // we find one that is. 4158 while ((S->getFlags() & Scope::DeclScope) == 0 || 4159 (S->getFlags() & Scope::TemplateParamScope) != 0) 4160 S = S->getParent(); 4161 4162 // Determine the type of the declaration. 4163 QualType R = GetTypeForDeclarator(D, S, 0); 4164 if (R.isNull()) 4165 return true; 4166 4167 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { 4168 // Cannot explicitly instantiate a typedef. 4169 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef) 4170 << Name; 4171 return true; 4172 } 4173 4174 // C++0x [temp.explicit]p1: 4175 // [...] An explicit instantiation of a function template shall not use the 4176 // inline or constexpr specifiers. 4177 // Presumably, this also applies to member functions of class templates as 4178 // well. 4179 if (D.getDeclSpec().isInlineSpecified() && getLangOptions().CPlusPlus0x) 4180 Diag(D.getDeclSpec().getInlineSpecLoc(), 4181 diag::err_explicit_instantiation_inline) 4182 << CodeModificationHint::CreateRemoval( 4183 SourceRange(D.getDeclSpec().getInlineSpecLoc())); 4184 4185 // FIXME: check for constexpr specifier. 4186 4187 // C++0x [temp.explicit]p2: 4188 // There are two forms of explicit instantiation: an explicit instantiation 4189 // definition and an explicit instantiation declaration. An explicit 4190 // instantiation declaration begins with the extern keyword. [...] 4191 TemplateSpecializationKind TSK 4192 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition 4193 : TSK_ExplicitInstantiationDeclaration; 4194 4195 LookupResult Previous(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName); 4196 LookupParsedName(Previous, S, &D.getCXXScopeSpec()); 4197 4198 if (!R->isFunctionType()) { 4199 // C++ [temp.explicit]p1: 4200 // A [...] static data member of a class template can be explicitly 4201 // instantiated from the member definition associated with its class 4202 // template. 4203 if (Previous.isAmbiguous()) 4204 return true; 4205 4206 VarDecl *Prev = dyn_cast_or_null<VarDecl>( 4207 Previous.getAsSingleDecl(Context)); 4208 if (!Prev || !Prev->isStaticDataMember()) { 4209 // We expect to see a data data member here. 4210 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known) 4211 << Name; 4212 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 4213 P != PEnd; ++P) 4214 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here); 4215 return true; 4216 } 4217 4218 if (!Prev->getInstantiatedFromStaticDataMember()) { 4219 // FIXME: Check for explicit specialization? 4220 Diag(D.getIdentifierLoc(), 4221 diag::err_explicit_instantiation_data_member_not_instantiated) 4222 << Prev; 4223 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here); 4224 // FIXME: Can we provide a note showing where this was declared? 4225 return true; 4226 } 4227 4228 // C++0x [temp.explicit]p2: 4229 // If the explicit instantiation is for a member function, a member class 4230 // or a static data member of a class template specialization, the name of 4231 // the class template specialization in the qualified-id for the member 4232 // name shall be a simple-template-id. 4233 // 4234 // C++98 has the same restriction, just worded differently. 4235 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 4236 Diag(D.getIdentifierLoc(), 4237 diag::err_explicit_instantiation_without_qualified_id) 4238 << Prev << D.getCXXScopeSpec().getRange(); 4239 4240 // Check the scope of this explicit instantiation. 4241 CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true); 4242 4243 // Verify that it is okay to explicitly instantiate here. 4244 MemberSpecializationInfo *MSInfo = Prev->getMemberSpecializationInfo(); 4245 assert(MSInfo && "Missing static data member specialization info?"); 4246 bool SuppressNew = false; 4247 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev, 4248 MSInfo->getTemplateSpecializationKind(), 4249 MSInfo->getPointOfInstantiation(), 4250 SuppressNew)) 4251 return true; 4252 if (SuppressNew) 4253 return DeclPtrTy(); 4254 4255 // Instantiate static data member. 4256 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 4257 if (TSK == TSK_ExplicitInstantiationDefinition) 4258 InstantiateStaticDataMemberDefinition(D.getIdentifierLoc(), Prev, false, 4259 /*DefinitionRequired=*/true); 4260 4261 // FIXME: Create an ExplicitInstantiation node? 4262 return DeclPtrTy(); 4263 } 4264 4265 // If the declarator is a template-id, translate the parser's template 4266 // argument list into our AST format. 4267 bool HasExplicitTemplateArgs = false; 4268 llvm::SmallVector<TemplateArgumentLoc, 16> TemplateArgs; 4269 if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) { 4270 TemplateIdAnnotation *TemplateId = D.getName().TemplateId; 4271 ASTTemplateArgsPtr TemplateArgsPtr(*this, 4272 TemplateId->getTemplateArgs(), 4273 TemplateId->NumArgs); 4274 translateTemplateArguments(TemplateArgsPtr, 4275 TemplateArgs); 4276 HasExplicitTemplateArgs = true; 4277 TemplateArgsPtr.release(); 4278 } 4279 4280 // C++ [temp.explicit]p1: 4281 // A [...] function [...] can be explicitly instantiated from its template. 4282 // A member function [...] of a class template can be explicitly 4283 // instantiated from the member definition associated with its class 4284 // template. 4285 llvm::SmallVector<FunctionDecl *, 8> Matches; 4286 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end(); 4287 P != PEnd; ++P) { 4288 NamedDecl *Prev = *P; 4289 if (!HasExplicitTemplateArgs) { 4290 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) { 4291 if (Context.hasSameUnqualifiedType(Method->getType(), R)) { 4292 Matches.clear(); 4293 Matches.push_back(Method); 4294 break; 4295 } 4296 } 4297 } 4298 4299 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev); 4300 if (!FunTmpl) 4301 continue; 4302 4303 TemplateDeductionInfo Info(Context); 4304 FunctionDecl *Specialization = 0; 4305 if (TemplateDeductionResult TDK 4306 = DeduceTemplateArguments(FunTmpl, HasExplicitTemplateArgs, 4307 TemplateArgs.data(), TemplateArgs.size(), 4308 R, Specialization, Info)) { 4309 // FIXME: Keep track of almost-matches? 4310 (void)TDK; 4311 continue; 4312 } 4313 4314 Matches.push_back(Specialization); 4315 } 4316 4317 // Find the most specialized function template specialization. 4318 FunctionDecl *Specialization 4319 = getMostSpecialized(Matches.data(), Matches.size(), TPOC_Other, 4320 D.getIdentifierLoc(), 4321 PartialDiagnostic(diag::err_explicit_instantiation_not_known) << Name, 4322 PartialDiagnostic(diag::err_explicit_instantiation_ambiguous) << Name, 4323 PartialDiagnostic(diag::note_explicit_instantiation_candidate)); 4324 4325 if (!Specialization) 4326 return true; 4327 4328 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) { 4329 Diag(D.getIdentifierLoc(), 4330 diag::err_explicit_instantiation_member_function_not_instantiated) 4331 << Specialization 4332 << (Specialization->getTemplateSpecializationKind() == 4333 TSK_ExplicitSpecialization); 4334 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here); 4335 return true; 4336 } 4337 4338 FunctionDecl *PrevDecl = Specialization->getPreviousDeclaration(); 4339 if (!PrevDecl && Specialization->isThisDeclarationADefinition()) 4340 PrevDecl = Specialization; 4341 4342 if (PrevDecl) { 4343 bool SuppressNew = false; 4344 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, 4345 PrevDecl, 4346 PrevDecl->getTemplateSpecializationKind(), 4347 PrevDecl->getPointOfInstantiation(), 4348 SuppressNew)) 4349 return true; 4350 4351 // FIXME: We may still want to build some representation of this 4352 // explicit specialization. 4353 if (SuppressNew) 4354 return DeclPtrTy(); 4355 } 4356 4357 if (TSK == TSK_ExplicitInstantiationDefinition) 4358 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization, 4359 false, /*DefinitionRequired=*/true); 4360 4361 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc()); 4362 4363 // C++0x [temp.explicit]p2: 4364 // If the explicit instantiation is for a member function, a member class 4365 // or a static data member of a class template specialization, the name of 4366 // the class template specialization in the qualified-id for the member 4367 // name shall be a simple-template-id. 4368 // 4369 // C++98 has the same restriction, just worded differently. 4370 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate(); 4371 if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl && 4372 D.getCXXScopeSpec().isSet() && 4373 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec())) 4374 Diag(D.getIdentifierLoc(), 4375 diag::err_explicit_instantiation_without_qualified_id) 4376 << Specialization << D.getCXXScopeSpec().getRange(); 4377 4378 CheckExplicitInstantiationScope(*this, 4379 FunTmpl? (NamedDecl *)FunTmpl 4380 : Specialization->getInstantiatedFromMemberFunction(), 4381 D.getIdentifierLoc(), 4382 D.getCXXScopeSpec().isSet()); 4383 4384 // FIXME: Create some kind of ExplicitInstantiationDecl here. 4385 return DeclPtrTy(); 4386} 4387 4388Sema::TypeResult 4389Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 4390 const CXXScopeSpec &SS, IdentifierInfo *Name, 4391 SourceLocation TagLoc, SourceLocation NameLoc) { 4392 // This has to hold, because SS is expected to be defined. 4393 assert(Name && "Expected a name in a dependent tag"); 4394 4395 NestedNameSpecifier *NNS 4396 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 4397 if (!NNS) 4398 return true; 4399 4400 QualType T = CheckTypenameType(NNS, *Name, SourceRange(TagLoc, NameLoc)); 4401 if (T.isNull()) 4402 return true; 4403 4404 TagDecl::TagKind TagKind = TagDecl::getTagKindForTypeSpec(TagSpec); 4405 QualType ElabType = Context.getElaboratedType(T, TagKind); 4406 4407 return ElabType.getAsOpaquePtr(); 4408} 4409 4410Sema::TypeResult 4411Sema::ActOnTypenameType(SourceLocation TypenameLoc, const CXXScopeSpec &SS, 4412 const IdentifierInfo &II, SourceLocation IdLoc) { 4413 NestedNameSpecifier *NNS 4414 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 4415 if (!NNS) 4416 return true; 4417 4418 QualType T = CheckTypenameType(NNS, II, SourceRange(TypenameLoc, IdLoc)); 4419 if (T.isNull()) 4420 return true; 4421 return T.getAsOpaquePtr(); 4422} 4423 4424Sema::TypeResult 4425Sema::ActOnTypenameType(SourceLocation TypenameLoc, const CXXScopeSpec &SS, 4426 SourceLocation TemplateLoc, TypeTy *Ty) { 4427 QualType T = GetTypeFromParser(Ty); 4428 NestedNameSpecifier *NNS 4429 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 4430 const TemplateSpecializationType *TemplateId 4431 = T->getAs<TemplateSpecializationType>(); 4432 assert(TemplateId && "Expected a template specialization type"); 4433 4434 if (computeDeclContext(SS, false)) { 4435 // If we can compute a declaration context, then the "typename" 4436 // keyword was superfluous. Just build a QualifiedNameType to keep 4437 // track of the nested-name-specifier. 4438 4439 // FIXME: Note that the QualifiedNameType had the "typename" keyword! 4440 return Context.getQualifiedNameType(NNS, T).getAsOpaquePtr(); 4441 } 4442 4443 return Context.getTypenameType(NNS, TemplateId).getAsOpaquePtr(); 4444} 4445 4446/// \brief Build the type that describes a C++ typename specifier, 4447/// e.g., "typename T::type". 4448QualType 4449Sema::CheckTypenameType(NestedNameSpecifier *NNS, const IdentifierInfo &II, 4450 SourceRange Range) { 4451 CXXRecordDecl *CurrentInstantiation = 0; 4452 if (NNS->isDependent()) { 4453 CurrentInstantiation = getCurrentInstantiationOf(NNS); 4454 4455 // If the nested-name-specifier does not refer to the current 4456 // instantiation, then build a typename type. 4457 if (!CurrentInstantiation) 4458 return Context.getTypenameType(NNS, &II); 4459 4460 // The nested-name-specifier refers to the current instantiation, so the 4461 // "typename" keyword itself is superfluous. In C++03, the program is 4462 // actually ill-formed. However, DR 382 (in C++0x CD1) allows such 4463 // extraneous "typename" keywords, and we retroactively apply this DR to 4464 // C++03 code. 4465 } 4466 4467 DeclContext *Ctx = 0; 4468 4469 if (CurrentInstantiation) 4470 Ctx = CurrentInstantiation; 4471 else { 4472 CXXScopeSpec SS; 4473 SS.setScopeRep(NNS); 4474 SS.setRange(Range); 4475 if (RequireCompleteDeclContext(SS)) 4476 return QualType(); 4477 4478 Ctx = computeDeclContext(SS); 4479 } 4480 assert(Ctx && "No declaration context?"); 4481 4482 DeclarationName Name(&II); 4483 LookupResult Result(*this, Name, Range.getEnd(), LookupOrdinaryName); 4484 LookupQualifiedName(Result, Ctx); 4485 unsigned DiagID = 0; 4486 Decl *Referenced = 0; 4487 switch (Result.getResultKind()) { 4488 case LookupResult::NotFound: 4489 DiagID = diag::err_typename_nested_not_found; 4490 break; 4491 4492 case LookupResult::Found: 4493 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) { 4494 // We found a type. Build a QualifiedNameType, since the 4495 // typename-specifier was just sugar. FIXME: Tell 4496 // QualifiedNameType that it has a "typename" prefix. 4497 return Context.getQualifiedNameType(NNS, Context.getTypeDeclType(Type)); 4498 } 4499 4500 DiagID = diag::err_typename_nested_not_type; 4501 Referenced = Result.getFoundDecl(); 4502 break; 4503 4504 case LookupResult::FoundOverloaded: 4505 DiagID = diag::err_typename_nested_not_type; 4506 Referenced = *Result.begin(); 4507 break; 4508 4509 case LookupResult::Ambiguous: 4510 return QualType(); 4511 } 4512 4513 // If we get here, it's because name lookup did not find a 4514 // type. Emit an appropriate diagnostic and return an error. 4515 Diag(Range.getEnd(), DiagID) << Range << Name << Ctx; 4516 if (Referenced) 4517 Diag(Referenced->getLocation(), diag::note_typename_refers_here) 4518 << Name; 4519 return QualType(); 4520} 4521 4522namespace { 4523 // See Sema::RebuildTypeInCurrentInstantiation 4524 class VISIBILITY_HIDDEN CurrentInstantiationRebuilder 4525 : public TreeTransform<CurrentInstantiationRebuilder> { 4526 SourceLocation Loc; 4527 DeclarationName Entity; 4528 4529 public: 4530 CurrentInstantiationRebuilder(Sema &SemaRef, 4531 SourceLocation Loc, 4532 DeclarationName Entity) 4533 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef), 4534 Loc(Loc), Entity(Entity) { } 4535 4536 /// \brief Determine whether the given type \p T has already been 4537 /// transformed. 4538 /// 4539 /// For the purposes of type reconstruction, a type has already been 4540 /// transformed if it is NULL or if it is not dependent. 4541 bool AlreadyTransformed(QualType T) { 4542 return T.isNull() || !T->isDependentType(); 4543 } 4544 4545 /// \brief Returns the location of the entity whose type is being 4546 /// rebuilt. 4547 SourceLocation getBaseLocation() { return Loc; } 4548 4549 /// \brief Returns the name of the entity whose type is being rebuilt. 4550 DeclarationName getBaseEntity() { return Entity; } 4551 4552 /// \brief Sets the "base" location and entity when that 4553 /// information is known based on another transformation. 4554 void setBase(SourceLocation Loc, DeclarationName Entity) { 4555 this->Loc = Loc; 4556 this->Entity = Entity; 4557 } 4558 4559 /// \brief Transforms an expression by returning the expression itself 4560 /// (an identity function). 4561 /// 4562 /// FIXME: This is completely unsafe; we will need to actually clone the 4563 /// expressions. 4564 Sema::OwningExprResult TransformExpr(Expr *E) { 4565 return getSema().Owned(E); 4566 } 4567 4568 /// \brief Transforms a typename type by determining whether the type now 4569 /// refers to a member of the current instantiation, and then 4570 /// type-checking and building a QualifiedNameType (when possible). 4571 QualType TransformTypenameType(TypeLocBuilder &TLB, TypenameTypeLoc TL); 4572 }; 4573} 4574 4575QualType 4576CurrentInstantiationRebuilder::TransformTypenameType(TypeLocBuilder &TLB, 4577 TypenameTypeLoc TL) { 4578 TypenameType *T = TL.getTypePtr(); 4579 4580 NestedNameSpecifier *NNS 4581 = TransformNestedNameSpecifier(T->getQualifier(), 4582 /*FIXME:*/SourceRange(getBaseLocation())); 4583 if (!NNS) 4584 return QualType(); 4585 4586 // If the nested-name-specifier did not change, and we cannot compute the 4587 // context corresponding to the nested-name-specifier, then this 4588 // typename type will not change; exit early. 4589 CXXScopeSpec SS; 4590 SS.setRange(SourceRange(getBaseLocation())); 4591 SS.setScopeRep(NNS); 4592 4593 QualType Result; 4594 if (NNS == T->getQualifier() && getSema().computeDeclContext(SS) == 0) 4595 Result = QualType(T, 0); 4596 4597 // Rebuild the typename type, which will probably turn into a 4598 // QualifiedNameType. 4599 else if (const TemplateSpecializationType *TemplateId = T->getTemplateId()) { 4600 QualType NewTemplateId 4601 = TransformType(QualType(TemplateId, 0)); 4602 if (NewTemplateId.isNull()) 4603 return QualType(); 4604 4605 if (NNS == T->getQualifier() && 4606 NewTemplateId == QualType(TemplateId, 0)) 4607 Result = QualType(T, 0); 4608 else 4609 Result = getDerived().RebuildTypenameType(NNS, NewTemplateId); 4610 } else 4611 Result = getDerived().RebuildTypenameType(NNS, T->getIdentifier(), 4612 SourceRange(TL.getNameLoc())); 4613 4614 TypenameTypeLoc NewTL = TLB.push<TypenameTypeLoc>(Result); 4615 NewTL.setNameLoc(TL.getNameLoc()); 4616 return Result; 4617} 4618 4619/// \brief Rebuilds a type within the context of the current instantiation. 4620/// 4621/// The type \p T is part of the type of an out-of-line member definition of 4622/// a class template (or class template partial specialization) that was parsed 4623/// and constructed before we entered the scope of the class template (or 4624/// partial specialization thereof). This routine will rebuild that type now 4625/// that we have entered the declarator's scope, which may produce different 4626/// canonical types, e.g., 4627/// 4628/// \code 4629/// template<typename T> 4630/// struct X { 4631/// typedef T* pointer; 4632/// pointer data(); 4633/// }; 4634/// 4635/// template<typename T> 4636/// typename X<T>::pointer X<T>::data() { ... } 4637/// \endcode 4638/// 4639/// Here, the type "typename X<T>::pointer" will be created as a TypenameType, 4640/// since we do not know that we can look into X<T> when we parsed the type. 4641/// This function will rebuild the type, performing the lookup of "pointer" 4642/// in X<T> and returning a QualifiedNameType whose canonical type is the same 4643/// as the canonical type of T*, allowing the return types of the out-of-line 4644/// definition and the declaration to match. 4645QualType Sema::RebuildTypeInCurrentInstantiation(QualType T, SourceLocation Loc, 4646 DeclarationName Name) { 4647 if (T.isNull() || !T->isDependentType()) 4648 return T; 4649 4650 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name); 4651 return Rebuilder.TransformType(T); 4652} 4653 4654/// \brief Produces a formatted string that describes the binding of 4655/// template parameters to template arguments. 4656std::string 4657Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 4658 const TemplateArgumentList &Args) { 4659 // FIXME: For variadic templates, we'll need to get the structured list. 4660 return getTemplateArgumentBindingsText(Params, Args.getFlatArgumentList(), 4661 Args.flat_size()); 4662} 4663 4664std::string 4665Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params, 4666 const TemplateArgument *Args, 4667 unsigned NumArgs) { 4668 std::string Result; 4669 4670 if (!Params || Params->size() == 0 || NumArgs == 0) 4671 return Result; 4672 4673 for (unsigned I = 0, N = Params->size(); I != N; ++I) { 4674 if (I >= NumArgs) 4675 break; 4676 4677 if (I == 0) 4678 Result += "[with "; 4679 else 4680 Result += ", "; 4681 4682 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) { 4683 Result += Id->getName(); 4684 } else { 4685 Result += '$'; 4686 Result += llvm::utostr(I); 4687 } 4688 4689 Result += " = "; 4690 4691 switch (Args[I].getKind()) { 4692 case TemplateArgument::Null: 4693 Result += "<no value>"; 4694 break; 4695 4696 case TemplateArgument::Type: { 4697 std::string TypeStr; 4698 Args[I].getAsType().getAsStringInternal(TypeStr, 4699 Context.PrintingPolicy); 4700 Result += TypeStr; 4701 break; 4702 } 4703 4704 case TemplateArgument::Declaration: { 4705 bool Unnamed = true; 4706 if (NamedDecl *ND = dyn_cast_or_null<NamedDecl>(Args[I].getAsDecl())) { 4707 if (ND->getDeclName()) { 4708 Unnamed = false; 4709 Result += ND->getNameAsString(); 4710 } 4711 } 4712 4713 if (Unnamed) { 4714 Result += "<anonymous>"; 4715 } 4716 break; 4717 } 4718 4719 case TemplateArgument::Template: { 4720 std::string Str; 4721 llvm::raw_string_ostream OS(Str); 4722 Args[I].getAsTemplate().print(OS, Context.PrintingPolicy); 4723 Result += OS.str(); 4724 break; 4725 } 4726 4727 case TemplateArgument::Integral: { 4728 Result += Args[I].getAsIntegral()->toString(10); 4729 break; 4730 } 4731 4732 case TemplateArgument::Expression: { 4733 assert(false && "No expressions in deduced template arguments!"); 4734 Result += "<expression>"; 4735 break; 4736 } 4737 4738 case TemplateArgument::Pack: 4739 // FIXME: Format template argument packs 4740 Result += "<template argument pack>"; 4741 break; 4742 } 4743 } 4744 4745 Result += ']'; 4746 return Result; 4747} 4748