ParseTemplate.cpp revision 194179
1//===--- ParseTemplate.cpp - Template Parsing -----------------------------===// 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// 10// This file implements parsing of C++ templates. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Parse/Parser.h" 15#include "clang/Parse/ParseDiagnostic.h" 16#include "clang/Parse/DeclSpec.h" 17#include "clang/Parse/Scope.h" 18using namespace clang; 19 20/// \brief Parse a template declaration, explicit instantiation, or 21/// explicit specialization. 22Parser::DeclPtrTy 23Parser::ParseDeclarationStartingWithTemplate(unsigned Context, 24 SourceLocation &DeclEnd, 25 AccessSpecifier AS) { 26 if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) 27 return ParseExplicitInstantiation(ConsumeToken(), DeclEnd); 28 29 return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS); 30} 31 32/// \brief Parse a template declaration or an explicit specialization. 33/// 34/// Template declarations include one or more template parameter lists 35/// and either the function or class template declaration. Explicit 36/// specializations contain one or more 'template < >' prefixes 37/// followed by a (possibly templated) declaration. Since the 38/// syntactic form of both features is nearly identical, we parse all 39/// of the template headers together and let semantic analysis sort 40/// the declarations from the explicit specializations. 41/// 42/// template-declaration: [C++ temp] 43/// 'export'[opt] 'template' '<' template-parameter-list '>' declaration 44/// 45/// explicit-specialization: [ C++ temp.expl.spec] 46/// 'template' '<' '>' declaration 47Parser::DeclPtrTy 48Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context, 49 SourceLocation &DeclEnd, 50 AccessSpecifier AS) { 51 assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) && 52 "Token does not start a template declaration."); 53 54 // Enter template-parameter scope. 55 ParseScope TemplateParmScope(this, Scope::TemplateParamScope); 56 57 // Parse multiple levels of template headers within this template 58 // parameter scope, e.g., 59 // 60 // template<typename T> 61 // template<typename U> 62 // class A<T>::B { ... }; 63 // 64 // We parse multiple levels non-recursively so that we can build a 65 // single data structure containing all of the template parameter 66 // lists to easily differentiate between the case above and: 67 // 68 // template<typename T> 69 // class A { 70 // template<typename U> class B; 71 // }; 72 // 73 // In the first case, the action for declaring A<T>::B receives 74 // both template parameter lists. In the second case, the action for 75 // defining A<T>::B receives just the inner template parameter list 76 // (and retrieves the outer template parameter list from its 77 // context). 78 bool isSpecialiation = true; 79 TemplateParameterLists ParamLists; 80 do { 81 // Consume the 'export', if any. 82 SourceLocation ExportLoc; 83 if (Tok.is(tok::kw_export)) { 84 ExportLoc = ConsumeToken(); 85 } 86 87 // Consume the 'template', which should be here. 88 SourceLocation TemplateLoc; 89 if (Tok.is(tok::kw_template)) { 90 TemplateLoc = ConsumeToken(); 91 } else { 92 Diag(Tok.getLocation(), diag::err_expected_template); 93 return DeclPtrTy(); 94 } 95 96 // Parse the '<' template-parameter-list '>' 97 SourceLocation LAngleLoc, RAngleLoc; 98 TemplateParameterList TemplateParams; 99 ParseTemplateParameters(ParamLists.size(), TemplateParams, LAngleLoc, 100 RAngleLoc); 101 102 if (!TemplateParams.empty()) 103 isSpecialiation = false; 104 105 ParamLists.push_back( 106 Actions.ActOnTemplateParameterList(ParamLists.size(), ExportLoc, 107 TemplateLoc, LAngleLoc, 108 TemplateParams.data(), 109 TemplateParams.size(), RAngleLoc)); 110 } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template)); 111 112 // Parse the actual template declaration. 113 return ParseSingleDeclarationAfterTemplate(Context, 114 ParsedTemplateInfo(&ParamLists, 115 isSpecialiation), 116 DeclEnd, AS); 117} 118 119/// \brief Parse a single declaration that declares a template, 120/// template specialization, or explicit instantiation of a template. 121/// 122/// \param TemplateParams if non-NULL, the template parameter lists 123/// that preceded this declaration. In this case, the declaration is a 124/// template declaration, out-of-line definition of a template, or an 125/// explicit template specialization. When NULL, the declaration is an 126/// explicit template instantiation. 127/// 128/// \param TemplateLoc when TemplateParams is NULL, the location of 129/// the 'template' keyword that indicates that we have an explicit 130/// template instantiation. 131/// 132/// \param DeclEnd will receive the source location of the last token 133/// within this declaration. 134/// 135/// \param AS the access specifier associated with this 136/// declaration. Will be AS_none for namespace-scope declarations. 137/// 138/// \returns the new declaration. 139Parser::DeclPtrTy 140Parser::ParseSingleDeclarationAfterTemplate( 141 unsigned Context, 142 const ParsedTemplateInfo &TemplateInfo, 143 SourceLocation &DeclEnd, 144 AccessSpecifier AS) { 145 assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate && 146 "Template information required"); 147 148 // Parse the declaration specifiers. 149 DeclSpec DS; 150 // FIXME: Pass TemplateLoc through for explicit template instantiations 151 ParseDeclarationSpecifiers(DS, TemplateInfo, AS); 152 153 if (Tok.is(tok::semi)) { 154 DeclEnd = ConsumeToken(); 155 return Actions.ParsedFreeStandingDeclSpec(CurScope, DS); 156 } 157 158 // Parse the declarator. 159 Declarator DeclaratorInfo(DS, (Declarator::TheContext)Context); 160 ParseDeclarator(DeclaratorInfo); 161 // Error parsing the declarator? 162 if (!DeclaratorInfo.hasName()) { 163 // If so, skip until the semi-colon or a }. 164 SkipUntil(tok::r_brace, true, true); 165 if (Tok.is(tok::semi)) 166 ConsumeToken(); 167 return DeclPtrTy(); 168 } 169 170 // If we have a declaration or declarator list, handle it. 171 if (isDeclarationAfterDeclarator()) { 172 // Parse this declaration. 173 DeclPtrTy ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo); 174 175 if (Tok.is(tok::comma)) { 176 Diag(Tok, diag::err_multiple_template_declarators) 177 << (int)TemplateInfo.Kind; 178 SkipUntil(tok::semi, true, false); 179 return ThisDecl; 180 } 181 182 // Eat the semi colon after the declaration. 183 ExpectAndConsume(tok::semi, diag::err_expected_semi_declation); 184 return ThisDecl; 185 } 186 187 if (DeclaratorInfo.isFunctionDeclarator() && 188 isStartOfFunctionDefinition()) { 189 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { 190 Diag(Tok, diag::err_function_declared_typedef); 191 192 if (Tok.is(tok::l_brace)) { 193 // This recovery skips the entire function body. It would be nice 194 // to simply call ParseFunctionDefinition() below, however Sema 195 // assumes the declarator represents a function, not a typedef. 196 ConsumeBrace(); 197 SkipUntil(tok::r_brace, true); 198 } else { 199 SkipUntil(tok::semi); 200 } 201 return DeclPtrTy(); 202 } 203 return ParseFunctionDefinition(DeclaratorInfo); 204 } 205 206 if (DeclaratorInfo.isFunctionDeclarator()) 207 Diag(Tok, diag::err_expected_fn_body); 208 else 209 Diag(Tok, diag::err_invalid_token_after_toplevel_declarator); 210 SkipUntil(tok::semi); 211 return DeclPtrTy(); 212} 213 214/// ParseTemplateParameters - Parses a template-parameter-list enclosed in 215/// angle brackets. Depth is the depth of this template-parameter-list, which 216/// is the number of template headers directly enclosing this template header. 217/// TemplateParams is the current list of template parameters we're building. 218/// The template parameter we parse will be added to this list. LAngleLoc and 219/// RAngleLoc will receive the positions of the '<' and '>', respectively, 220/// that enclose this template parameter list. 221bool Parser::ParseTemplateParameters(unsigned Depth, 222 TemplateParameterList &TemplateParams, 223 SourceLocation &LAngleLoc, 224 SourceLocation &RAngleLoc) { 225 // Get the template parameter list. 226 if(!Tok.is(tok::less)) { 227 Diag(Tok.getLocation(), diag::err_expected_less_after) << "template"; 228 return false; 229 } 230 LAngleLoc = ConsumeToken(); 231 232 // Try to parse the template parameter list. 233 if (Tok.is(tok::greater)) 234 RAngleLoc = ConsumeToken(); 235 else if(ParseTemplateParameterList(Depth, TemplateParams)) { 236 if(!Tok.is(tok::greater)) { 237 Diag(Tok.getLocation(), diag::err_expected_greater); 238 return false; 239 } 240 RAngleLoc = ConsumeToken(); 241 } 242 return true; 243} 244 245/// ParseTemplateParameterList - Parse a template parameter list. If 246/// the parsing fails badly (i.e., closing bracket was left out), this 247/// will try to put the token stream in a reasonable position (closing 248/// a statement, etc.) and return false. 249/// 250/// template-parameter-list: [C++ temp] 251/// template-parameter 252/// template-parameter-list ',' template-parameter 253bool 254Parser::ParseTemplateParameterList(unsigned Depth, 255 TemplateParameterList &TemplateParams) { 256 while(1) { 257 if (DeclPtrTy TmpParam 258 = ParseTemplateParameter(Depth, TemplateParams.size())) { 259 TemplateParams.push_back(TmpParam); 260 } else { 261 // If we failed to parse a template parameter, skip until we find 262 // a comma or closing brace. 263 SkipUntil(tok::comma, tok::greater, true, true); 264 } 265 266 // Did we find a comma or the end of the template parmeter list? 267 if(Tok.is(tok::comma)) { 268 ConsumeToken(); 269 } else if(Tok.is(tok::greater)) { 270 // Don't consume this... that's done by template parser. 271 break; 272 } else { 273 // Somebody probably forgot to close the template. Skip ahead and 274 // try to get out of the expression. This error is currently 275 // subsumed by whatever goes on in ParseTemplateParameter. 276 // TODO: This could match >>, and it would be nice to avoid those 277 // silly errors with template <vec<T>>. 278 // Diag(Tok.getLocation(), diag::err_expected_comma_greater); 279 SkipUntil(tok::greater, true, true); 280 return false; 281 } 282 } 283 return true; 284} 285 286/// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]). 287/// 288/// template-parameter: [C++ temp.param] 289/// type-parameter 290/// parameter-declaration 291/// 292/// type-parameter: (see below) 293/// 'class' ...[opt][C++0x] identifier[opt] 294/// 'class' identifier[opt] '=' type-id 295/// 'typename' ...[opt][C++0x] identifier[opt] 296/// 'typename' identifier[opt] '=' type-id 297/// 'template' ...[opt][C++0x] '<' template-parameter-list '>' 'class' identifier[opt] 298/// 'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression 299Parser::DeclPtrTy 300Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) { 301 if(Tok.is(tok::kw_class) || 302 (Tok.is(tok::kw_typename) && 303 // FIXME: Next token has not been annotated! 304 NextToken().isNot(tok::annot_typename))) { 305 return ParseTypeParameter(Depth, Position); 306 } 307 308 if(Tok.is(tok::kw_template)) 309 return ParseTemplateTemplateParameter(Depth, Position); 310 311 // If it's none of the above, then it must be a parameter declaration. 312 // NOTE: This will pick up errors in the closure of the template parameter 313 // list (e.g., template < ; Check here to implement >> style closures. 314 return ParseNonTypeTemplateParameter(Depth, Position); 315} 316 317/// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]). 318/// Other kinds of template parameters are parsed in 319/// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter. 320/// 321/// type-parameter: [C++ temp.param] 322/// 'class' ...[opt][C++0x] identifier[opt] 323/// 'class' identifier[opt] '=' type-id 324/// 'typename' ...[opt][C++0x] identifier[opt] 325/// 'typename' identifier[opt] '=' type-id 326Parser::DeclPtrTy Parser::ParseTypeParameter(unsigned Depth, unsigned Position){ 327 assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) && 328 "A type-parameter starts with 'class' or 'typename'"); 329 330 // Consume the 'class' or 'typename' keyword. 331 bool TypenameKeyword = Tok.is(tok::kw_typename); 332 SourceLocation KeyLoc = ConsumeToken(); 333 334 // Grab the ellipsis (if given). 335 bool Ellipsis = false; 336 SourceLocation EllipsisLoc; 337 if (Tok.is(tok::ellipsis)) { 338 Ellipsis = true; 339 EllipsisLoc = ConsumeToken(); 340 341 if (!getLang().CPlusPlus0x) 342 Diag(EllipsisLoc, diag::err_variadic_templates); 343 } 344 345 // Grab the template parameter name (if given) 346 SourceLocation NameLoc; 347 IdentifierInfo* ParamName = 0; 348 if(Tok.is(tok::identifier)) { 349 ParamName = Tok.getIdentifierInfo(); 350 NameLoc = ConsumeToken(); 351 } else if(Tok.is(tok::equal) || Tok.is(tok::comma) || 352 Tok.is(tok::greater)) { 353 // Unnamed template parameter. Don't have to do anything here, just 354 // don't consume this token. 355 } else { 356 Diag(Tok.getLocation(), diag::err_expected_ident); 357 return DeclPtrTy(); 358 } 359 360 DeclPtrTy TypeParam = Actions.ActOnTypeParameter(CurScope, TypenameKeyword, 361 Ellipsis, EllipsisLoc, 362 KeyLoc, ParamName, NameLoc, 363 Depth, Position); 364 365 // Grab a default type id (if given). 366 if(Tok.is(tok::equal)) { 367 SourceLocation EqualLoc = ConsumeToken(); 368 SourceLocation DefaultLoc = Tok.getLocation(); 369 TypeResult DefaultType = ParseTypeName(); 370 if (!DefaultType.isInvalid()) 371 Actions.ActOnTypeParameterDefault(TypeParam, EqualLoc, DefaultLoc, 372 DefaultType.get()); 373 } 374 375 return TypeParam; 376} 377 378/// ParseTemplateTemplateParameter - Handle the parsing of template 379/// template parameters. 380/// 381/// type-parameter: [C++ temp.param] 382/// 'template' '<' template-parameter-list '>' 'class' identifier[opt] 383/// 'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression 384Parser::DeclPtrTy 385Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { 386 assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); 387 388 // Handle the template <...> part. 389 SourceLocation TemplateLoc = ConsumeToken(); 390 TemplateParameterList TemplateParams; 391 SourceLocation LAngleLoc, RAngleLoc; 392 { 393 ParseScope TemplateParmScope(this, Scope::TemplateParamScope); 394 if(!ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, 395 RAngleLoc)) { 396 return DeclPtrTy(); 397 } 398 } 399 400 // Generate a meaningful error if the user forgot to put class before the 401 // identifier, comma, or greater. 402 if(!Tok.is(tok::kw_class)) { 403 Diag(Tok.getLocation(), diag::err_expected_class_before) 404 << PP.getSpelling(Tok); 405 return DeclPtrTy(); 406 } 407 SourceLocation ClassLoc = ConsumeToken(); 408 409 // Get the identifier, if given. 410 SourceLocation NameLoc; 411 IdentifierInfo* ParamName = 0; 412 if(Tok.is(tok::identifier)) { 413 ParamName = Tok.getIdentifierInfo(); 414 NameLoc = ConsumeToken(); 415 } else if(Tok.is(tok::equal) || Tok.is(tok::comma) || Tok.is(tok::greater)) { 416 // Unnamed template parameter. Don't have to do anything here, just 417 // don't consume this token. 418 } else { 419 Diag(Tok.getLocation(), diag::err_expected_ident); 420 return DeclPtrTy(); 421 } 422 423 TemplateParamsTy *ParamList = 424 Actions.ActOnTemplateParameterList(Depth, SourceLocation(), 425 TemplateLoc, LAngleLoc, 426 &TemplateParams[0], 427 TemplateParams.size(), 428 RAngleLoc); 429 430 Parser::DeclPtrTy Param 431 = Actions.ActOnTemplateTemplateParameter(CurScope, TemplateLoc, 432 ParamList, ParamName, 433 NameLoc, Depth, Position); 434 435 // Get the a default value, if given. 436 if (Tok.is(tok::equal)) { 437 SourceLocation EqualLoc = ConsumeToken(); 438 OwningExprResult DefaultExpr = ParseCXXIdExpression(); 439 if (DefaultExpr.isInvalid()) 440 return Param; 441 else if (Param) 442 Actions.ActOnTemplateTemplateParameterDefault(Param, EqualLoc, 443 move(DefaultExpr)); 444 } 445 446 return Param; 447} 448 449/// ParseNonTypeTemplateParameter - Handle the parsing of non-type 450/// template parameters (e.g., in "template<int Size> class array;"). 451/// 452/// template-parameter: 453/// ... 454/// parameter-declaration 455/// 456/// NOTE: It would be ideal to simply call out to ParseParameterDeclaration(), 457/// but that didn't work out to well. Instead, this tries to recrate the basic 458/// parsing of parameter declarations, but tries to constrain it for template 459/// parameters. 460/// FIXME: We need to make a ParseParameterDeclaration that works for 461/// non-type template parameters and normal function parameters. 462Parser::DeclPtrTy 463Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) { 464 SourceLocation StartLoc = Tok.getLocation(); 465 466 // Parse the declaration-specifiers (i.e., the type). 467 // FIXME: The type should probably be restricted in some way... Not all 468 // declarators (parts of declarators?) are accepted for parameters. 469 DeclSpec DS; 470 ParseDeclarationSpecifiers(DS); 471 472 // Parse this as a typename. 473 Declarator ParamDecl(DS, Declarator::TemplateParamContext); 474 ParseDeclarator(ParamDecl); 475 if (DS.getTypeSpecType() == DeclSpec::TST_unspecified && !DS.getTypeRep()) { 476 // This probably shouldn't happen - and it's more of a Sema thing, but 477 // basically we didn't parse the type name because we couldn't associate 478 // it with an AST node. we should just skip to the comma or greater. 479 // TODO: This is currently a placeholder for some kind of Sema Error. 480 Diag(Tok.getLocation(), diag::err_parse_error); 481 SkipUntil(tok::comma, tok::greater, true, true); 482 return DeclPtrTy(); 483 } 484 485 // Create the parameter. 486 DeclPtrTy Param = Actions.ActOnNonTypeTemplateParameter(CurScope, ParamDecl, 487 Depth, Position); 488 489 // If there is a default value, parse it. 490 if (Tok.is(tok::equal)) { 491 SourceLocation EqualLoc = ConsumeToken(); 492 493 // C++ [temp.param]p15: 494 // When parsing a default template-argument for a non-type 495 // template-parameter, the first non-nested > is taken as the 496 // end of the template-parameter-list rather than a greater-than 497 // operator. 498 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 499 500 OwningExprResult DefaultArg = ParseAssignmentExpression(); 501 if (DefaultArg.isInvalid()) 502 SkipUntil(tok::comma, tok::greater, true, true); 503 else if (Param) 504 Actions.ActOnNonTypeTemplateParameterDefault(Param, EqualLoc, 505 move(DefaultArg)); 506 } 507 508 return Param; 509} 510 511/// \brief Parses a template-id that after the template name has 512/// already been parsed. 513/// 514/// This routine takes care of parsing the enclosed template argument 515/// list ('<' template-parameter-list [opt] '>') and placing the 516/// results into a form that can be transferred to semantic analysis. 517/// 518/// \param Template the template declaration produced by isTemplateName 519/// 520/// \param TemplateNameLoc the source location of the template name 521/// 522/// \param SS if non-NULL, the nested-name-specifier preceding the 523/// template name. 524/// 525/// \param ConsumeLastToken if true, then we will consume the last 526/// token that forms the template-id. Otherwise, we will leave the 527/// last token in the stream (e.g., so that it can be replaced with an 528/// annotation token). 529bool 530Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template, 531 SourceLocation TemplateNameLoc, 532 const CXXScopeSpec *SS, 533 bool ConsumeLastToken, 534 SourceLocation &LAngleLoc, 535 TemplateArgList &TemplateArgs, 536 TemplateArgIsTypeList &TemplateArgIsType, 537 TemplateArgLocationList &TemplateArgLocations, 538 SourceLocation &RAngleLoc) { 539 assert(Tok.is(tok::less) && "Must have already parsed the template-name"); 540 541 // Consume the '<'. 542 LAngleLoc = ConsumeToken(); 543 544 // Parse the optional template-argument-list. 545 bool Invalid = false; 546 { 547 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 548 if (Tok.isNot(tok::greater)) 549 Invalid = ParseTemplateArgumentList(TemplateArgs, TemplateArgIsType, 550 TemplateArgLocations); 551 552 if (Invalid) { 553 // Try to find the closing '>'. 554 SkipUntil(tok::greater, true, !ConsumeLastToken); 555 556 return true; 557 } 558 } 559 560 if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater)) 561 return true; 562 563 // Determine the location of the '>' or '>>'. Only consume this 564 // token if the caller asked us to. 565 RAngleLoc = Tok.getLocation(); 566 567 if (Tok.is(tok::greatergreater)) { 568 if (!getLang().CPlusPlus0x) { 569 const char *ReplaceStr = "> >"; 570 if (NextToken().is(tok::greater) || NextToken().is(tok::greatergreater)) 571 ReplaceStr = "> > "; 572 573 Diag(Tok.getLocation(), diag::err_two_right_angle_brackets_need_space) 574 << CodeModificationHint::CreateReplacement( 575 SourceRange(Tok.getLocation()), ReplaceStr); 576 } 577 578 Tok.setKind(tok::greater); 579 if (!ConsumeLastToken) { 580 // Since we're not supposed to consume the '>>' token, we need 581 // to insert a second '>' token after the first. 582 PP.EnterToken(Tok); 583 } 584 } else if (ConsumeLastToken) 585 ConsumeToken(); 586 587 return false; 588} 589 590/// \brief Replace the tokens that form a simple-template-id with an 591/// annotation token containing the complete template-id. 592/// 593/// The first token in the stream must be the name of a template that 594/// is followed by a '<'. This routine will parse the complete 595/// simple-template-id and replace the tokens with a single annotation 596/// token with one of two different kinds: if the template-id names a 597/// type (and \p AllowTypeAnnotation is true), the annotation token is 598/// a type annotation that includes the optional nested-name-specifier 599/// (\p SS). Otherwise, the annotation token is a template-id 600/// annotation that does not include the optional 601/// nested-name-specifier. 602/// 603/// \param Template the declaration of the template named by the first 604/// token (an identifier), as returned from \c Action::isTemplateName(). 605/// 606/// \param TemplateNameKind the kind of template that \p Template 607/// refers to, as returned from \c Action::isTemplateName(). 608/// 609/// \param SS if non-NULL, the nested-name-specifier that precedes 610/// this template name. 611/// 612/// \param TemplateKWLoc if valid, specifies that this template-id 613/// annotation was preceded by the 'template' keyword and gives the 614/// location of that keyword. If invalid (the default), then this 615/// template-id was not preceded by a 'template' keyword. 616/// 617/// \param AllowTypeAnnotation if true (the default), then a 618/// simple-template-id that refers to a class template, template 619/// template parameter, or other template that produces a type will be 620/// replaced with a type annotation token. Otherwise, the 621/// simple-template-id is always replaced with a template-id 622/// annotation token. 623void Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK, 624 const CXXScopeSpec *SS, 625 SourceLocation TemplateKWLoc, 626 bool AllowTypeAnnotation) { 627 assert(getLang().CPlusPlus && "Can only annotate template-ids in C++"); 628 assert(Template && Tok.is(tok::identifier) && NextToken().is(tok::less) && 629 "Parser isn't at the beginning of a template-id"); 630 631 // Consume the template-name. 632 IdentifierInfo *Name = Tok.getIdentifierInfo(); 633 SourceLocation TemplateNameLoc = ConsumeToken(); 634 635 // Parse the enclosed template argument list. 636 SourceLocation LAngleLoc, RAngleLoc; 637 TemplateArgList TemplateArgs; 638 TemplateArgIsTypeList TemplateArgIsType; 639 TemplateArgLocationList TemplateArgLocations; 640 bool Invalid = ParseTemplateIdAfterTemplateName(Template, TemplateNameLoc, 641 SS, false, LAngleLoc, 642 TemplateArgs, 643 TemplateArgIsType, 644 TemplateArgLocations, 645 RAngleLoc); 646 647 ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(), 648 TemplateArgIsType.data(), 649 TemplateArgs.size()); 650 651 if (Invalid) // FIXME: How to recover from a broken template-id? 652 return; 653 654 // Build the annotation token. 655 if (TNK == TNK_Type_template && AllowTypeAnnotation) { 656 Action::TypeResult Type 657 = Actions.ActOnTemplateIdType(Template, TemplateNameLoc, 658 LAngleLoc, TemplateArgsPtr, 659 &TemplateArgLocations[0], 660 RAngleLoc); 661 if (Type.isInvalid()) // FIXME: better recovery? 662 return; 663 664 Tok.setKind(tok::annot_typename); 665 Tok.setAnnotationValue(Type.get()); 666 if (SS && SS->isNotEmpty()) 667 Tok.setLocation(SS->getBeginLoc()); 668 else if (TemplateKWLoc.isValid()) 669 Tok.setLocation(TemplateKWLoc); 670 else 671 Tok.setLocation(TemplateNameLoc); 672 } else { 673 // Build a template-id annotation token that can be processed 674 // later. 675 Tok.setKind(tok::annot_template_id); 676 TemplateIdAnnotation *TemplateId 677 = TemplateIdAnnotation::Allocate(TemplateArgs.size()); 678 TemplateId->TemplateNameLoc = TemplateNameLoc; 679 TemplateId->Name = Name; 680 TemplateId->Template = Template.getAs<void*>(); 681 TemplateId->Kind = TNK; 682 TemplateId->LAngleLoc = LAngleLoc; 683 TemplateId->RAngleLoc = RAngleLoc; 684 void **Args = TemplateId->getTemplateArgs(); 685 bool *ArgIsType = TemplateId->getTemplateArgIsType(); 686 SourceLocation *ArgLocs = TemplateId->getTemplateArgLocations(); 687 for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg) { 688 Args[Arg] = TemplateArgs[Arg]; 689 ArgIsType[Arg] = TemplateArgIsType[Arg]; 690 ArgLocs[Arg] = TemplateArgLocations[Arg]; 691 } 692 Tok.setAnnotationValue(TemplateId); 693 if (TemplateKWLoc.isValid()) 694 Tok.setLocation(TemplateKWLoc); 695 else 696 Tok.setLocation(TemplateNameLoc); 697 698 TemplateArgsPtr.release(); 699 } 700 701 // Common fields for the annotation token 702 Tok.setAnnotationEndLoc(RAngleLoc); 703 704 // In case the tokens were cached, have Preprocessor replace them with the 705 // annotation token. 706 PP.AnnotateCachedTokens(Tok); 707} 708 709/// \brief Replaces a template-id annotation token with a type 710/// annotation token. 711/// 712/// If there was a failure when forming the type from the template-id, 713/// a type annotation token will still be created, but will have a 714/// NULL type pointer to signify an error. 715void Parser::AnnotateTemplateIdTokenAsType(const CXXScopeSpec *SS) { 716 assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens"); 717 718 TemplateIdAnnotation *TemplateId 719 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 720 assert((TemplateId->Kind == TNK_Type_template || 721 TemplateId->Kind == TNK_Dependent_template_name) && 722 "Only works for type and dependent templates"); 723 724 ASTTemplateArgsPtr TemplateArgsPtr(Actions, 725 TemplateId->getTemplateArgs(), 726 TemplateId->getTemplateArgIsType(), 727 TemplateId->NumArgs); 728 729 Action::TypeResult Type 730 = Actions.ActOnTemplateIdType(TemplateTy::make(TemplateId->Template), 731 TemplateId->TemplateNameLoc, 732 TemplateId->LAngleLoc, 733 TemplateArgsPtr, 734 TemplateId->getTemplateArgLocations(), 735 TemplateId->RAngleLoc); 736 // Create the new "type" annotation token. 737 Tok.setKind(tok::annot_typename); 738 Tok.setAnnotationValue(Type.isInvalid()? 0 : Type.get()); 739 if (SS && SS->isNotEmpty()) // it was a C++ qualified type name. 740 Tok.setLocation(SS->getBeginLoc()); 741 742 // We might be backtracking, in which case we need to replace the 743 // template-id annotation token with the type annotation within the 744 // set of cached tokens. That way, we won't try to form the same 745 // class template specialization again. 746 PP.ReplaceLastTokenWithAnnotation(Tok); 747 TemplateId->Destroy(); 748} 749 750/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]). 751/// 752/// template-argument: [C++ 14.2] 753/// assignment-expression 754/// type-id 755/// id-expression 756void *Parser::ParseTemplateArgument(bool &ArgIsType) { 757 // C++ [temp.arg]p2: 758 // In a template-argument, an ambiguity between a type-id and an 759 // expression is resolved to a type-id, regardless of the form of 760 // the corresponding template-parameter. 761 // 762 // Therefore, we initially try to parse a type-id. 763 if (isCXXTypeId(TypeIdAsTemplateArgument)) { 764 ArgIsType = true; 765 TypeResult TypeArg = ParseTypeName(); 766 if (TypeArg.isInvalid()) 767 return 0; 768 return TypeArg.get(); 769 } 770 771 OwningExprResult ExprArg = ParseAssignmentExpression(); 772 if (ExprArg.isInvalid() || !ExprArg.get()) 773 return 0; 774 775 ArgIsType = false; 776 return ExprArg.release(); 777} 778 779/// ParseTemplateArgumentList - Parse a C++ template-argument-list 780/// (C++ [temp.names]). Returns true if there was an error. 781/// 782/// template-argument-list: [C++ 14.2] 783/// template-argument 784/// template-argument-list ',' template-argument 785bool 786Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs, 787 TemplateArgIsTypeList &TemplateArgIsType, 788 TemplateArgLocationList &TemplateArgLocations) { 789 while (true) { 790 bool IsType = false; 791 SourceLocation Loc = Tok.getLocation(); 792 void *Arg = ParseTemplateArgument(IsType); 793 if (Arg) { 794 TemplateArgs.push_back(Arg); 795 TemplateArgIsType.push_back(IsType); 796 TemplateArgLocations.push_back(Loc); 797 } else { 798 SkipUntil(tok::comma, tok::greater, true, true); 799 return true; 800 } 801 802 // If the next token is a comma, consume it and keep reading 803 // arguments. 804 if (Tok.isNot(tok::comma)) break; 805 806 // Consume the comma. 807 ConsumeToken(); 808 } 809 810 return Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater); 811} 812 813/// \brief Parse a C++ explicit template instantiation 814/// (C++ [temp.explicit]). 815/// 816/// explicit-instantiation: 817/// 'template' declaration 818Parser::DeclPtrTy 819Parser::ParseExplicitInstantiation(SourceLocation TemplateLoc, 820 SourceLocation &DeclEnd) { 821 return ParseSingleDeclarationAfterTemplate(Declarator::FileContext, 822 ParsedTemplateInfo(TemplateLoc), 823 DeclEnd, AS_none); 824} 825