ParseTemplate.cpp revision 193326
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' identifier[opt] 294/// 'class' identifier[opt] '=' type-id 295/// 'typename' identifier[opt] 296/// 'typename' identifier[opt] '=' type-id 297/// 'template' '<' 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' identifier[opt] 323/// 'class' identifier[opt] '=' type-id 324/// 'typename' 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 template parameter name (if given) 335 SourceLocation NameLoc; 336 IdentifierInfo* ParamName = 0; 337 if(Tok.is(tok::identifier)) { 338 ParamName = Tok.getIdentifierInfo(); 339 NameLoc = ConsumeToken(); 340 } else if(Tok.is(tok::equal) || Tok.is(tok::comma) || 341 Tok.is(tok::greater)) { 342 // Unnamed template parameter. Don't have to do anything here, just 343 // don't consume this token. 344 } else { 345 Diag(Tok.getLocation(), diag::err_expected_ident); 346 return DeclPtrTy(); 347 } 348 349 DeclPtrTy TypeParam = Actions.ActOnTypeParameter(CurScope, TypenameKeyword, 350 KeyLoc, ParamName, NameLoc, 351 Depth, Position); 352 353 // Grab a default type id (if given). 354 if(Tok.is(tok::equal)) { 355 SourceLocation EqualLoc = ConsumeToken(); 356 SourceLocation DefaultLoc = Tok.getLocation(); 357 TypeResult DefaultType = ParseTypeName(); 358 if (!DefaultType.isInvalid()) 359 Actions.ActOnTypeParameterDefault(TypeParam, EqualLoc, DefaultLoc, 360 DefaultType.get()); 361 } 362 363 return TypeParam; 364} 365 366/// ParseTemplateTemplateParameter - Handle the parsing of template 367/// template parameters. 368/// 369/// type-parameter: [C++ temp.param] 370/// 'template' '<' template-parameter-list '>' 'class' identifier[opt] 371/// 'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression 372Parser::DeclPtrTy 373Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { 374 assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); 375 376 // Handle the template <...> part. 377 SourceLocation TemplateLoc = ConsumeToken(); 378 TemplateParameterList TemplateParams; 379 SourceLocation LAngleLoc, RAngleLoc; 380 { 381 ParseScope TemplateParmScope(this, Scope::TemplateParamScope); 382 if(!ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, 383 RAngleLoc)) { 384 return DeclPtrTy(); 385 } 386 } 387 388 // Generate a meaningful error if the user forgot to put class before the 389 // identifier, comma, or greater. 390 if(!Tok.is(tok::kw_class)) { 391 Diag(Tok.getLocation(), diag::err_expected_class_before) 392 << PP.getSpelling(Tok); 393 return DeclPtrTy(); 394 } 395 SourceLocation ClassLoc = ConsumeToken(); 396 397 // Get the identifier, if given. 398 SourceLocation NameLoc; 399 IdentifierInfo* ParamName = 0; 400 if(Tok.is(tok::identifier)) { 401 ParamName = Tok.getIdentifierInfo(); 402 NameLoc = ConsumeToken(); 403 } else if(Tok.is(tok::equal) || Tok.is(tok::comma) || Tok.is(tok::greater)) { 404 // Unnamed template parameter. Don't have to do anything here, just 405 // don't consume this token. 406 } else { 407 Diag(Tok.getLocation(), diag::err_expected_ident); 408 return DeclPtrTy(); 409 } 410 411 TemplateParamsTy *ParamList = 412 Actions.ActOnTemplateParameterList(Depth, SourceLocation(), 413 TemplateLoc, LAngleLoc, 414 &TemplateParams[0], 415 TemplateParams.size(), 416 RAngleLoc); 417 418 Parser::DeclPtrTy Param 419 = Actions.ActOnTemplateTemplateParameter(CurScope, TemplateLoc, 420 ParamList, ParamName, 421 NameLoc, Depth, Position); 422 423 // Get the a default value, if given. 424 if (Tok.is(tok::equal)) { 425 SourceLocation EqualLoc = ConsumeToken(); 426 OwningExprResult DefaultExpr = ParseCXXIdExpression(); 427 if (DefaultExpr.isInvalid()) 428 return Param; 429 else if (Param) 430 Actions.ActOnTemplateTemplateParameterDefault(Param, EqualLoc, 431 move(DefaultExpr)); 432 } 433 434 return Param; 435} 436 437/// ParseNonTypeTemplateParameter - Handle the parsing of non-type 438/// template parameters (e.g., in "template<int Size> class array;"). 439/// 440/// template-parameter: 441/// ... 442/// parameter-declaration 443/// 444/// NOTE: It would be ideal to simply call out to ParseParameterDeclaration(), 445/// but that didn't work out to well. Instead, this tries to recrate the basic 446/// parsing of parameter declarations, but tries to constrain it for template 447/// parameters. 448/// FIXME: We need to make a ParseParameterDeclaration that works for 449/// non-type template parameters and normal function parameters. 450Parser::DeclPtrTy 451Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) { 452 SourceLocation StartLoc = Tok.getLocation(); 453 454 // Parse the declaration-specifiers (i.e., the type). 455 // FIXME: The type should probably be restricted in some way... Not all 456 // declarators (parts of declarators?) are accepted for parameters. 457 DeclSpec DS; 458 ParseDeclarationSpecifiers(DS); 459 460 // Parse this as a typename. 461 Declarator ParamDecl(DS, Declarator::TemplateParamContext); 462 ParseDeclarator(ParamDecl); 463 if (DS.getTypeSpecType() == DeclSpec::TST_unspecified && !DS.getTypeRep()) { 464 // This probably shouldn't happen - and it's more of a Sema thing, but 465 // basically we didn't parse the type name because we couldn't associate 466 // it with an AST node. we should just skip to the comma or greater. 467 // TODO: This is currently a placeholder for some kind of Sema Error. 468 Diag(Tok.getLocation(), diag::err_parse_error); 469 SkipUntil(tok::comma, tok::greater, true, true); 470 return DeclPtrTy(); 471 } 472 473 // Create the parameter. 474 DeclPtrTy Param = Actions.ActOnNonTypeTemplateParameter(CurScope, ParamDecl, 475 Depth, Position); 476 477 // If there is a default value, parse it. 478 if (Tok.is(tok::equal)) { 479 SourceLocation EqualLoc = ConsumeToken(); 480 481 // C++ [temp.param]p15: 482 // When parsing a default template-argument for a non-type 483 // template-parameter, the first non-nested > is taken as the 484 // end of the template-parameter-list rather than a greater-than 485 // operator. 486 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 487 488 OwningExprResult DefaultArg = ParseAssignmentExpression(); 489 if (DefaultArg.isInvalid()) 490 SkipUntil(tok::comma, tok::greater, true, true); 491 else if (Param) 492 Actions.ActOnNonTypeTemplateParameterDefault(Param, EqualLoc, 493 move(DefaultArg)); 494 } 495 496 return Param; 497} 498 499/// \brief Parses a template-id that after the template name has 500/// already been parsed. 501/// 502/// This routine takes care of parsing the enclosed template argument 503/// list ('<' template-parameter-list [opt] '>') and placing the 504/// results into a form that can be transferred to semantic analysis. 505/// 506/// \param Template the template declaration produced by isTemplateName 507/// 508/// \param TemplateNameLoc the source location of the template name 509/// 510/// \param SS if non-NULL, the nested-name-specifier preceding the 511/// template name. 512/// 513/// \param ConsumeLastToken if true, then we will consume the last 514/// token that forms the template-id. Otherwise, we will leave the 515/// last token in the stream (e.g., so that it can be replaced with an 516/// annotation token). 517bool 518Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template, 519 SourceLocation TemplateNameLoc, 520 const CXXScopeSpec *SS, 521 bool ConsumeLastToken, 522 SourceLocation &LAngleLoc, 523 TemplateArgList &TemplateArgs, 524 TemplateArgIsTypeList &TemplateArgIsType, 525 TemplateArgLocationList &TemplateArgLocations, 526 SourceLocation &RAngleLoc) { 527 assert(Tok.is(tok::less) && "Must have already parsed the template-name"); 528 529 // Consume the '<'. 530 LAngleLoc = ConsumeToken(); 531 532 // Parse the optional template-argument-list. 533 bool Invalid = false; 534 { 535 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 536 if (Tok.isNot(tok::greater)) 537 Invalid = ParseTemplateArgumentList(TemplateArgs, TemplateArgIsType, 538 TemplateArgLocations); 539 540 if (Invalid) { 541 // Try to find the closing '>'. 542 SkipUntil(tok::greater, true, !ConsumeLastToken); 543 544 return true; 545 } 546 } 547 548 if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater)) 549 return true; 550 551 // Determine the location of the '>' or '>>'. Only consume this 552 // token if the caller asked us to. 553 RAngleLoc = Tok.getLocation(); 554 555 if (Tok.is(tok::greatergreater)) { 556 if (!getLang().CPlusPlus0x) { 557 const char *ReplaceStr = "> >"; 558 if (NextToken().is(tok::greater) || NextToken().is(tok::greatergreater)) 559 ReplaceStr = "> > "; 560 561 Diag(Tok.getLocation(), diag::err_two_right_angle_brackets_need_space) 562 << CodeModificationHint::CreateReplacement( 563 SourceRange(Tok.getLocation()), ReplaceStr); 564 } 565 566 Tok.setKind(tok::greater); 567 if (!ConsumeLastToken) { 568 // Since we're not supposed to consume the '>>' token, we need 569 // to insert a second '>' token after the first. 570 PP.EnterToken(Tok); 571 } 572 } else if (ConsumeLastToken) 573 ConsumeToken(); 574 575 return false; 576} 577 578/// \brief Replace the tokens that form a simple-template-id with an 579/// annotation token containing the complete template-id. 580/// 581/// The first token in the stream must be the name of a template that 582/// is followed by a '<'. This routine will parse the complete 583/// simple-template-id and replace the tokens with a single annotation 584/// token with one of two different kinds: if the template-id names a 585/// type (and \p AllowTypeAnnotation is true), the annotation token is 586/// a type annotation that includes the optional nested-name-specifier 587/// (\p SS). Otherwise, the annotation token is a template-id 588/// annotation that does not include the optional 589/// nested-name-specifier. 590/// 591/// \param Template the declaration of the template named by the first 592/// token (an identifier), as returned from \c Action::isTemplateName(). 593/// 594/// \param TemplateNameKind the kind of template that \p Template 595/// refers to, as returned from \c Action::isTemplateName(). 596/// 597/// \param SS if non-NULL, the nested-name-specifier that precedes 598/// this template name. 599/// 600/// \param TemplateKWLoc if valid, specifies that this template-id 601/// annotation was preceded by the 'template' keyword and gives the 602/// location of that keyword. If invalid (the default), then this 603/// template-id was not preceded by a 'template' keyword. 604/// 605/// \param AllowTypeAnnotation if true (the default), then a 606/// simple-template-id that refers to a class template, template 607/// template parameter, or other template that produces a type will be 608/// replaced with a type annotation token. Otherwise, the 609/// simple-template-id is always replaced with a template-id 610/// annotation token. 611void Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK, 612 const CXXScopeSpec *SS, 613 SourceLocation TemplateKWLoc, 614 bool AllowTypeAnnotation) { 615 assert(getLang().CPlusPlus && "Can only annotate template-ids in C++"); 616 assert(Template && Tok.is(tok::identifier) && NextToken().is(tok::less) && 617 "Parser isn't at the beginning of a template-id"); 618 619 // Consume the template-name. 620 IdentifierInfo *Name = Tok.getIdentifierInfo(); 621 SourceLocation TemplateNameLoc = ConsumeToken(); 622 623 // Parse the enclosed template argument list. 624 SourceLocation LAngleLoc, RAngleLoc; 625 TemplateArgList TemplateArgs; 626 TemplateArgIsTypeList TemplateArgIsType; 627 TemplateArgLocationList TemplateArgLocations; 628 bool Invalid = ParseTemplateIdAfterTemplateName(Template, TemplateNameLoc, 629 SS, false, LAngleLoc, 630 TemplateArgs, 631 TemplateArgIsType, 632 TemplateArgLocations, 633 RAngleLoc); 634 635 ASTTemplateArgsPtr TemplateArgsPtr(Actions, TemplateArgs.data(), 636 TemplateArgIsType.data(), 637 TemplateArgs.size()); 638 639 if (Invalid) // FIXME: How to recover from a broken template-id? 640 return; 641 642 // Build the annotation token. 643 if (TNK == TNK_Type_template && AllowTypeAnnotation) { 644 Action::TypeResult Type 645 = Actions.ActOnTemplateIdType(Template, TemplateNameLoc, 646 LAngleLoc, TemplateArgsPtr, 647 &TemplateArgLocations[0], 648 RAngleLoc); 649 if (Type.isInvalid()) // FIXME: better recovery? 650 return; 651 652 Tok.setKind(tok::annot_typename); 653 Tok.setAnnotationValue(Type.get()); 654 if (SS && SS->isNotEmpty()) 655 Tok.setLocation(SS->getBeginLoc()); 656 else if (TemplateKWLoc.isValid()) 657 Tok.setLocation(TemplateKWLoc); 658 else 659 Tok.setLocation(TemplateNameLoc); 660 } else { 661 // Build a template-id annotation token that can be processed 662 // later. 663 Tok.setKind(tok::annot_template_id); 664 TemplateIdAnnotation *TemplateId 665 = TemplateIdAnnotation::Allocate(TemplateArgs.size()); 666 TemplateId->TemplateNameLoc = TemplateNameLoc; 667 TemplateId->Name = Name; 668 TemplateId->Template = Template.getAs<void*>(); 669 TemplateId->Kind = TNK; 670 TemplateId->LAngleLoc = LAngleLoc; 671 TemplateId->RAngleLoc = RAngleLoc; 672 void **Args = TemplateId->getTemplateArgs(); 673 bool *ArgIsType = TemplateId->getTemplateArgIsType(); 674 SourceLocation *ArgLocs = TemplateId->getTemplateArgLocations(); 675 for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg) { 676 Args[Arg] = TemplateArgs[Arg]; 677 ArgIsType[Arg] = TemplateArgIsType[Arg]; 678 ArgLocs[Arg] = TemplateArgLocations[Arg]; 679 } 680 Tok.setAnnotationValue(TemplateId); 681 if (TemplateKWLoc.isValid()) 682 Tok.setLocation(TemplateKWLoc); 683 else 684 Tok.setLocation(TemplateNameLoc); 685 686 TemplateArgsPtr.release(); 687 } 688 689 // Common fields for the annotation token 690 Tok.setAnnotationEndLoc(RAngleLoc); 691 692 // In case the tokens were cached, have Preprocessor replace them with the 693 // annotation token. 694 PP.AnnotateCachedTokens(Tok); 695} 696 697/// \brief Replaces a template-id annotation token with a type 698/// annotation token. 699/// 700/// If there was a failure when forming the type from the template-id, 701/// a type annotation token will still be created, but will have a 702/// NULL type pointer to signify an error. 703void Parser::AnnotateTemplateIdTokenAsType(const CXXScopeSpec *SS) { 704 assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens"); 705 706 TemplateIdAnnotation *TemplateId 707 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 708 assert((TemplateId->Kind == TNK_Type_template || 709 TemplateId->Kind == TNK_Dependent_template_name) && 710 "Only works for type and dependent templates"); 711 712 ASTTemplateArgsPtr TemplateArgsPtr(Actions, 713 TemplateId->getTemplateArgs(), 714 TemplateId->getTemplateArgIsType(), 715 TemplateId->NumArgs); 716 717 Action::TypeResult Type 718 = Actions.ActOnTemplateIdType(TemplateTy::make(TemplateId->Template), 719 TemplateId->TemplateNameLoc, 720 TemplateId->LAngleLoc, 721 TemplateArgsPtr, 722 TemplateId->getTemplateArgLocations(), 723 TemplateId->RAngleLoc); 724 // Create the new "type" annotation token. 725 Tok.setKind(tok::annot_typename); 726 Tok.setAnnotationValue(Type.isInvalid()? 0 : Type.get()); 727 if (SS && SS->isNotEmpty()) // it was a C++ qualified type name. 728 Tok.setLocation(SS->getBeginLoc()); 729 730 // We might be backtracking, in which case we need to replace the 731 // template-id annotation token with the type annotation within the 732 // set of cached tokens. That way, we won't try to form the same 733 // class template specialization again. 734 PP.ReplaceLastTokenWithAnnotation(Tok); 735 TemplateId->Destroy(); 736} 737 738/// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]). 739/// 740/// template-argument: [C++ 14.2] 741/// assignment-expression 742/// type-id 743/// id-expression 744void *Parser::ParseTemplateArgument(bool &ArgIsType) { 745 // C++ [temp.arg]p2: 746 // In a template-argument, an ambiguity between a type-id and an 747 // expression is resolved to a type-id, regardless of the form of 748 // the corresponding template-parameter. 749 // 750 // Therefore, we initially try to parse a type-id. 751 if (isCXXTypeId(TypeIdAsTemplateArgument)) { 752 ArgIsType = true; 753 TypeResult TypeArg = ParseTypeName(); 754 if (TypeArg.isInvalid()) 755 return 0; 756 return TypeArg.get(); 757 } 758 759 OwningExprResult ExprArg = ParseAssignmentExpression(); 760 if (ExprArg.isInvalid() || !ExprArg.get()) 761 return 0; 762 763 ArgIsType = false; 764 return ExprArg.release(); 765} 766 767/// ParseTemplateArgumentList - Parse a C++ template-argument-list 768/// (C++ [temp.names]). Returns true if there was an error. 769/// 770/// template-argument-list: [C++ 14.2] 771/// template-argument 772/// template-argument-list ',' template-argument 773bool 774Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs, 775 TemplateArgIsTypeList &TemplateArgIsType, 776 TemplateArgLocationList &TemplateArgLocations) { 777 while (true) { 778 bool IsType = false; 779 SourceLocation Loc = Tok.getLocation(); 780 void *Arg = ParseTemplateArgument(IsType); 781 if (Arg) { 782 TemplateArgs.push_back(Arg); 783 TemplateArgIsType.push_back(IsType); 784 TemplateArgLocations.push_back(Loc); 785 } else { 786 SkipUntil(tok::comma, tok::greater, true, true); 787 return true; 788 } 789 790 // If the next token is a comma, consume it and keep reading 791 // arguments. 792 if (Tok.isNot(tok::comma)) break; 793 794 // Consume the comma. 795 ConsumeToken(); 796 } 797 798 return Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater); 799} 800 801/// \brief Parse a C++ explicit template instantiation 802/// (C++ [temp.explicit]). 803/// 804/// explicit-instantiation: 805/// 'template' declaration 806Parser::DeclPtrTy 807Parser::ParseExplicitInstantiation(SourceLocation TemplateLoc, 808 SourceLocation &DeclEnd) { 809 return ParseSingleDeclarationAfterTemplate(Declarator::FileContext, 810 ParsedTemplateInfo(TemplateLoc), 811 DeclEnd, AS_none); 812} 813