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 "RAIIObjectsForParser.h" 16 #include "clang/AST/ASTConsumer.h" 17 #include "clang/AST/DeclTemplate.h" 18 #include "clang/Parse/ParseDiagnostic.h" 19 #include "clang/Sema/DeclSpec.h" 20 #include "clang/Sema/ParsedTemplate.h" 21 #include "clang/Sema/Scope.h" 22 using namespace clang; 23 24 /// \brief Parse a template declaration, explicit instantiation, or 25 /// explicit specialization. 26 Decl * 27 Parser::ParseDeclarationStartingWithTemplate(unsigned Context, 28 SourceLocation &DeclEnd, 29 AccessSpecifier AS, 30 AttributeList *AccessAttrs) { 31 ObjCDeclContextSwitch ObjCDC(*this); 32 33 if (Tok.is(tok::kw_template) && NextToken().isNot(tok::less)) { 34 return ParseExplicitInstantiation(Context, 35 SourceLocation(), ConsumeToken(), 36 DeclEnd, AS); 37 } 38 return ParseTemplateDeclarationOrSpecialization(Context, DeclEnd, AS, 39 AccessAttrs); 40 } 41 42 43 44 /// \brief Parse a template declaration or an explicit specialization. 45 /// 46 /// Template declarations include one or more template parameter lists 47 /// and either the function or class template declaration. Explicit 48 /// specializations contain one or more 'template < >' prefixes 49 /// followed by a (possibly templated) declaration. Since the 50 /// syntactic form of both features is nearly identical, we parse all 51 /// of the template headers together and let semantic analysis sort 52 /// the declarations from the explicit specializations. 53 /// 54 /// template-declaration: [C++ temp] 55 /// 'export'[opt] 'template' '<' template-parameter-list '>' declaration 56 /// 57 /// explicit-specialization: [ C++ temp.expl.spec] 58 /// 'template' '<' '>' declaration 59 Decl * 60 Parser::ParseTemplateDeclarationOrSpecialization(unsigned Context, 61 SourceLocation &DeclEnd, 62 AccessSpecifier AS, 63 AttributeList *AccessAttrs) { 64 assert((Tok.is(tok::kw_export) || Tok.is(tok::kw_template)) && 65 "Token does not start a template declaration."); 66 67 // Enter template-parameter scope. 68 ParseScope TemplateParmScope(this, Scope::TemplateParamScope); 69 70 // Tell the action that names should be checked in the context of 71 // the declaration to come. 72 ParsingDeclRAIIObject 73 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent); 74 75 // Parse multiple levels of template headers within this template 76 // parameter scope, e.g., 77 // 78 // template<typename T> 79 // template<typename U> 80 // class A<T>::B { ... }; 81 // 82 // We parse multiple levels non-recursively so that we can build a 83 // single data structure containing all of the template parameter 84 // lists to easily differentiate between the case above and: 85 // 86 // template<typename T> 87 // class A { 88 // template<typename U> class B; 89 // }; 90 // 91 // In the first case, the action for declaring A<T>::B receives 92 // both template parameter lists. In the second case, the action for 93 // defining A<T>::B receives just the inner template parameter list 94 // (and retrieves the outer template parameter list from its 95 // context). 96 bool isSpecialization = true; 97 bool LastParamListWasEmpty = false; 98 TemplateParameterLists ParamLists; 99 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth); 100 101 do { 102 // Consume the 'export', if any. 103 SourceLocation ExportLoc; 104 TryConsumeToken(tok::kw_export, ExportLoc); 105 106 // Consume the 'template', which should be here. 107 SourceLocation TemplateLoc; 108 if (!TryConsumeToken(tok::kw_template, TemplateLoc)) { 109 Diag(Tok.getLocation(), diag::err_expected_template); 110 return nullptr; 111 } 112 113 // Parse the '<' template-parameter-list '>' 114 SourceLocation LAngleLoc, RAngleLoc; 115 SmallVector<Decl*, 4> TemplateParams; 116 if (ParseTemplateParameters(CurTemplateDepthTracker.getDepth(), 117 TemplateParams, LAngleLoc, RAngleLoc)) { 118 // Skip until the semi-colon or a }. 119 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 120 TryConsumeToken(tok::semi); 121 return nullptr; 122 } 123 124 ParamLists.push_back( 125 Actions.ActOnTemplateParameterList(CurTemplateDepthTracker.getDepth(), 126 ExportLoc, 127 TemplateLoc, LAngleLoc, 128 TemplateParams.data(), 129 TemplateParams.size(), RAngleLoc)); 130 131 if (!TemplateParams.empty()) { 132 isSpecialization = false; 133 ++CurTemplateDepthTracker; 134 } else { 135 LastParamListWasEmpty = true; 136 } 137 } while (Tok.is(tok::kw_export) || Tok.is(tok::kw_template)); 138 139 // Parse the actual template declaration. 140 return ParseSingleDeclarationAfterTemplate(Context, 141 ParsedTemplateInfo(&ParamLists, 142 isSpecialization, 143 LastParamListWasEmpty), 144 ParsingTemplateParams, 145 DeclEnd, AS, AccessAttrs); 146 } 147 148 /// \brief Parse a single declaration that declares a template, 149 /// template specialization, or explicit instantiation of a template. 150 /// 151 /// \param DeclEnd will receive the source location of the last token 152 /// within this declaration. 153 /// 154 /// \param AS the access specifier associated with this 155 /// declaration. Will be AS_none for namespace-scope declarations. 156 /// 157 /// \returns the new declaration. 158 Decl * 159 Parser::ParseSingleDeclarationAfterTemplate( 160 unsigned Context, 161 const ParsedTemplateInfo &TemplateInfo, 162 ParsingDeclRAIIObject &DiagsFromTParams, 163 SourceLocation &DeclEnd, 164 AccessSpecifier AS, 165 AttributeList *AccessAttrs) { 166 assert(TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate && 167 "Template information required"); 168 169 if (Tok.is(tok::kw_static_assert)) { 170 // A static_assert declaration may not be templated. 171 Diag(Tok.getLocation(), diag::err_templated_invalid_declaration) 172 << TemplateInfo.getSourceRange(); 173 // Parse the static_assert declaration to improve error recovery. 174 return ParseStaticAssertDeclaration(DeclEnd); 175 } 176 177 if (Context == Declarator::MemberContext) { 178 // We are parsing a member template. 179 ParseCXXClassMemberDeclaration(AS, AccessAttrs, TemplateInfo, 180 &DiagsFromTParams); 181 return nullptr; 182 } 183 184 ParsedAttributesWithRange prefixAttrs(AttrFactory); 185 MaybeParseCXX11Attributes(prefixAttrs); 186 187 if (Tok.is(tok::kw_using)) 188 return ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd, 189 prefixAttrs); 190 191 // Parse the declaration specifiers, stealing any diagnostics from 192 // the template parameters. 193 ParsingDeclSpec DS(*this, &DiagsFromTParams); 194 195 ParseDeclarationSpecifiers(DS, TemplateInfo, AS, 196 getDeclSpecContextFromDeclaratorContext(Context)); 197 198 if (Tok.is(tok::semi)) { 199 ProhibitAttributes(prefixAttrs); 200 DeclEnd = ConsumeToken(); 201 Decl *Decl = Actions.ParsedFreeStandingDeclSpec( 202 getCurScope(), AS, DS, 203 TemplateInfo.TemplateParams ? *TemplateInfo.TemplateParams 204 : MultiTemplateParamsArg(), 205 TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation); 206 DS.complete(Decl); 207 return Decl; 208 } 209 210 // Move the attributes from the prefix into the DS. 211 if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) 212 ProhibitAttributes(prefixAttrs); 213 else 214 DS.takeAttributesFrom(prefixAttrs); 215 216 // Parse the declarator. 217 ParsingDeclarator DeclaratorInfo(*this, DS, (Declarator::TheContext)Context); 218 ParseDeclarator(DeclaratorInfo); 219 // Error parsing the declarator? 220 if (!DeclaratorInfo.hasName()) { 221 // If so, skip until the semi-colon or a }. 222 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 223 if (Tok.is(tok::semi)) 224 ConsumeToken(); 225 return nullptr; 226 } 227 228 LateParsedAttrList LateParsedAttrs(true); 229 if (DeclaratorInfo.isFunctionDeclarator()) 230 MaybeParseGNUAttributes(DeclaratorInfo, &LateParsedAttrs); 231 232 if (DeclaratorInfo.isFunctionDeclarator() && 233 isStartOfFunctionDefinition(DeclaratorInfo)) { 234 235 // Function definitions are only allowed at file scope and in C++ classes. 236 // The C++ inline method definition case is handled elsewhere, so we only 237 // need to handle the file scope definition case. 238 if (Context != Declarator::FileContext) { 239 Diag(Tok, diag::err_function_definition_not_allowed); 240 SkipMalformedDecl(); 241 return nullptr; 242 } 243 244 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { 245 // Recover by ignoring the 'typedef'. This was probably supposed to be 246 // the 'typename' keyword, which we should have already suggested adding 247 // if it's appropriate. 248 Diag(DS.getStorageClassSpecLoc(), diag::err_function_declared_typedef) 249 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); 250 DS.ClearStorageClassSpecs(); 251 } 252 253 if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) { 254 if (DeclaratorInfo.getName().getKind() != UnqualifiedId::IK_TemplateId) { 255 // If the declarator-id is not a template-id, issue a diagnostic and 256 // recover by ignoring the 'template' keyword. 257 Diag(Tok, diag::err_template_defn_explicit_instantiation) << 0; 258 return ParseFunctionDefinition(DeclaratorInfo, ParsedTemplateInfo(), 259 &LateParsedAttrs); 260 } else { 261 SourceLocation LAngleLoc 262 = PP.getLocForEndOfToken(TemplateInfo.TemplateLoc); 263 Diag(DeclaratorInfo.getIdentifierLoc(), 264 diag::err_explicit_instantiation_with_definition) 265 << SourceRange(TemplateInfo.TemplateLoc) 266 << FixItHint::CreateInsertion(LAngleLoc, "<>"); 267 268 // Recover as if it were an explicit specialization. 269 TemplateParameterLists FakedParamLists; 270 FakedParamLists.push_back(Actions.ActOnTemplateParameterList( 271 0, SourceLocation(), TemplateInfo.TemplateLoc, LAngleLoc, nullptr, 272 0, LAngleLoc)); 273 274 return ParseFunctionDefinition( 275 DeclaratorInfo, ParsedTemplateInfo(&FakedParamLists, 276 /*isSpecialization=*/true, 277 /*LastParamListWasEmpty=*/true), 278 &LateParsedAttrs); 279 } 280 } 281 return ParseFunctionDefinition(DeclaratorInfo, TemplateInfo, 282 &LateParsedAttrs); 283 } 284 285 // Parse this declaration. 286 Decl *ThisDecl = ParseDeclarationAfterDeclarator(DeclaratorInfo, 287 TemplateInfo); 288 289 if (Tok.is(tok::comma)) { 290 Diag(Tok, diag::err_multiple_template_declarators) 291 << (int)TemplateInfo.Kind; 292 SkipUntil(tok::semi); 293 return ThisDecl; 294 } 295 296 // Eat the semi colon after the declaration. 297 ExpectAndConsumeSemi(diag::err_expected_semi_declaration); 298 if (LateParsedAttrs.size() > 0) 299 ParseLexedAttributeList(LateParsedAttrs, ThisDecl, true, false); 300 DeclaratorInfo.complete(ThisDecl); 301 return ThisDecl; 302 } 303 304 /// ParseTemplateParameters - Parses a template-parameter-list enclosed in 305 /// angle brackets. Depth is the depth of this template-parameter-list, which 306 /// is the number of template headers directly enclosing this template header. 307 /// TemplateParams is the current list of template parameters we're building. 308 /// The template parameter we parse will be added to this list. LAngleLoc and 309 /// RAngleLoc will receive the positions of the '<' and '>', respectively, 310 /// that enclose this template parameter list. 311 /// 312 /// \returns true if an error occurred, false otherwise. 313 bool Parser::ParseTemplateParameters(unsigned Depth, 314 SmallVectorImpl<Decl*> &TemplateParams, 315 SourceLocation &LAngleLoc, 316 SourceLocation &RAngleLoc) { 317 // Get the template parameter list. 318 if (!TryConsumeToken(tok::less, LAngleLoc)) { 319 Diag(Tok.getLocation(), diag::err_expected_less_after) << "template"; 320 return true; 321 } 322 323 // Try to parse the template parameter list. 324 bool Failed = false; 325 if (!Tok.is(tok::greater) && !Tok.is(tok::greatergreater)) 326 Failed = ParseTemplateParameterList(Depth, TemplateParams); 327 328 if (Tok.is(tok::greatergreater)) { 329 // No diagnostic required here: a template-parameter-list can only be 330 // followed by a declaration or, for a template template parameter, the 331 // 'class' keyword. Therefore, the second '>' will be diagnosed later. 332 // This matters for elegant diagnosis of: 333 // template<template<typename>> struct S; 334 Tok.setKind(tok::greater); 335 RAngleLoc = Tok.getLocation(); 336 Tok.setLocation(Tok.getLocation().getLocWithOffset(1)); 337 } else if (!TryConsumeToken(tok::greater, RAngleLoc) && Failed) { 338 Diag(Tok.getLocation(), diag::err_expected) << tok::greater; 339 return true; 340 } 341 return false; 342 } 343 344 /// ParseTemplateParameterList - Parse a template parameter list. If 345 /// the parsing fails badly (i.e., closing bracket was left out), this 346 /// will try to put the token stream in a reasonable position (closing 347 /// a statement, etc.) and return false. 348 /// 349 /// template-parameter-list: [C++ temp] 350 /// template-parameter 351 /// template-parameter-list ',' template-parameter 352 bool 353 Parser::ParseTemplateParameterList(unsigned Depth, 354 SmallVectorImpl<Decl*> &TemplateParams) { 355 while (1) { 356 if (Decl *TmpParam 357 = ParseTemplateParameter(Depth, TemplateParams.size())) { 358 TemplateParams.push_back(TmpParam); 359 } else { 360 // If we failed to parse a template parameter, skip until we find 361 // a comma or closing brace. 362 SkipUntil(tok::comma, tok::greater, tok::greatergreater, 363 StopAtSemi | StopBeforeMatch); 364 } 365 366 // Did we find a comma or the end of the template parameter list? 367 if (Tok.is(tok::comma)) { 368 ConsumeToken(); 369 } else if (Tok.is(tok::greater) || Tok.is(tok::greatergreater)) { 370 // Don't consume this... that's done by template parser. 371 break; 372 } else { 373 // Somebody probably forgot to close the template. Skip ahead and 374 // try to get out of the expression. This error is currently 375 // subsumed by whatever goes on in ParseTemplateParameter. 376 Diag(Tok.getLocation(), diag::err_expected_comma_greater); 377 SkipUntil(tok::comma, tok::greater, tok::greatergreater, 378 StopAtSemi | StopBeforeMatch); 379 return false; 380 } 381 } 382 return true; 383 } 384 385 /// \brief Determine whether the parser is at the start of a template 386 /// type parameter. 387 bool Parser::isStartOfTemplateTypeParameter() { 388 if (Tok.is(tok::kw_class)) { 389 // "class" may be the start of an elaborated-type-specifier or a 390 // type-parameter. Per C++ [temp.param]p3, we prefer the type-parameter. 391 switch (NextToken().getKind()) { 392 case tok::equal: 393 case tok::comma: 394 case tok::greater: 395 case tok::greatergreater: 396 case tok::ellipsis: 397 return true; 398 399 case tok::identifier: 400 // This may be either a type-parameter or an elaborated-type-specifier. 401 // We have to look further. 402 break; 403 404 default: 405 return false; 406 } 407 408 switch (GetLookAheadToken(2).getKind()) { 409 case tok::equal: 410 case tok::comma: 411 case tok::greater: 412 case tok::greatergreater: 413 return true; 414 415 default: 416 return false; 417 } 418 } 419 420 if (Tok.isNot(tok::kw_typename)) 421 return false; 422 423 // C++ [temp.param]p2: 424 // There is no semantic difference between class and typename in a 425 // template-parameter. typename followed by an unqualified-id 426 // names a template type parameter. typename followed by a 427 // qualified-id denotes the type in a non-type 428 // parameter-declaration. 429 Token Next = NextToken(); 430 431 // If we have an identifier, skip over it. 432 if (Next.getKind() == tok::identifier) 433 Next = GetLookAheadToken(2); 434 435 switch (Next.getKind()) { 436 case tok::equal: 437 case tok::comma: 438 case tok::greater: 439 case tok::greatergreater: 440 case tok::ellipsis: 441 return true; 442 443 default: 444 return false; 445 } 446 } 447 448 /// ParseTemplateParameter - Parse a template-parameter (C++ [temp.param]). 449 /// 450 /// template-parameter: [C++ temp.param] 451 /// type-parameter 452 /// parameter-declaration 453 /// 454 /// type-parameter: (see below) 455 /// 'class' ...[opt] identifier[opt] 456 /// 'class' identifier[opt] '=' type-id 457 /// 'typename' ...[opt] identifier[opt] 458 /// 'typename' identifier[opt] '=' type-id 459 /// 'template' '<' template-parameter-list '>' 460 /// 'class' ...[opt] identifier[opt] 461 /// 'template' '<' template-parameter-list '>' 'class' identifier[opt] 462 /// = id-expression 463 Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) { 464 if (isStartOfTemplateTypeParameter()) 465 return ParseTypeParameter(Depth, Position); 466 467 if (Tok.is(tok::kw_template)) 468 return ParseTemplateTemplateParameter(Depth, Position); 469 470 // If it's none of the above, then it must be a parameter declaration. 471 // NOTE: This will pick up errors in the closure of the template parameter 472 // list (e.g., template < ; Check here to implement >> style closures. 473 return ParseNonTypeTemplateParameter(Depth, Position); 474 } 475 476 /// ParseTypeParameter - Parse a template type parameter (C++ [temp.param]). 477 /// Other kinds of template parameters are parsed in 478 /// ParseTemplateTemplateParameter and ParseNonTypeTemplateParameter. 479 /// 480 /// type-parameter: [C++ temp.param] 481 /// 'class' ...[opt][C++0x] identifier[opt] 482 /// 'class' identifier[opt] '=' type-id 483 /// 'typename' ...[opt][C++0x] identifier[opt] 484 /// 'typename' identifier[opt] '=' type-id 485 Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) { 486 assert((Tok.is(tok::kw_class) || Tok.is(tok::kw_typename)) && 487 "A type-parameter starts with 'class' or 'typename'"); 488 489 // Consume the 'class' or 'typename' keyword. 490 bool TypenameKeyword = Tok.is(tok::kw_typename); 491 SourceLocation KeyLoc = ConsumeToken(); 492 493 // Grab the ellipsis (if given). 494 SourceLocation EllipsisLoc; 495 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) { 496 Diag(EllipsisLoc, 497 getLangOpts().CPlusPlus11 498 ? diag::warn_cxx98_compat_variadic_templates 499 : diag::ext_variadic_templates); 500 } 501 502 // Grab the template parameter name (if given) 503 SourceLocation NameLoc; 504 IdentifierInfo *ParamName = nullptr; 505 if (Tok.is(tok::identifier)) { 506 ParamName = Tok.getIdentifierInfo(); 507 NameLoc = ConsumeToken(); 508 } else if (Tok.is(tok::equal) || Tok.is(tok::comma) || 509 Tok.is(tok::greater) || Tok.is(tok::greatergreater)) { 510 // Unnamed template parameter. Don't have to do anything here, just 511 // don't consume this token. 512 } else { 513 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier; 514 return nullptr; 515 } 516 517 // Recover from misplaced ellipsis. 518 bool AlreadyHasEllipsis = EllipsisLoc.isValid(); 519 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) 520 DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true); 521 522 // Grab a default argument (if available). 523 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before 524 // we introduce the type parameter into the local scope. 525 SourceLocation EqualLoc; 526 ParsedType DefaultArg; 527 if (TryConsumeToken(tok::equal, EqualLoc)) 528 DefaultArg = ParseTypeName(/*Range=*/nullptr, 529 Declarator::TemplateTypeArgContext).get(); 530 531 return Actions.ActOnTypeParameter(getCurScope(), TypenameKeyword, EllipsisLoc, 532 KeyLoc, ParamName, NameLoc, Depth, Position, 533 EqualLoc, DefaultArg); 534 } 535 536 /// ParseTemplateTemplateParameter - Handle the parsing of template 537 /// template parameters. 538 /// 539 /// type-parameter: [C++ temp.param] 540 /// 'template' '<' template-parameter-list '>' type-parameter-key 541 /// ...[opt] identifier[opt] 542 /// 'template' '<' template-parameter-list '>' type-parameter-key 543 /// identifier[opt] = id-expression 544 /// type-parameter-key: 545 /// 'class' 546 /// 'typename' [C++1z] 547 Decl * 548 Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) { 549 assert(Tok.is(tok::kw_template) && "Expected 'template' keyword"); 550 551 // Handle the template <...> part. 552 SourceLocation TemplateLoc = ConsumeToken(); 553 SmallVector<Decl*,8> TemplateParams; 554 SourceLocation LAngleLoc, RAngleLoc; 555 { 556 ParseScope TemplateParmScope(this, Scope::TemplateParamScope); 557 if (ParseTemplateParameters(Depth + 1, TemplateParams, LAngleLoc, 558 RAngleLoc)) { 559 return nullptr; 560 } 561 } 562 563 // Provide an ExtWarn if the C++1z feature of using 'typename' here is used. 564 // Generate a meaningful error if the user forgot to put class before the 565 // identifier, comma, or greater. Provide a fixit if the identifier, comma, 566 // or greater appear immediately or after 'struct'. In the latter case, 567 // replace the keyword with 'class'. 568 if (!TryConsumeToken(tok::kw_class)) { 569 bool Replace = Tok.is(tok::kw_typename) || Tok.is(tok::kw_struct); 570 const Token &Next = Tok.is(tok::kw_struct) ? NextToken() : Tok; 571 if (Tok.is(tok::kw_typename)) { 572 Diag(Tok.getLocation(), 573 getLangOpts().CPlusPlus1z 574 ? diag::warn_cxx14_compat_template_template_param_typename 575 : diag::ext_template_template_param_typename) 576 << (!getLangOpts().CPlusPlus1z 577 ? FixItHint::CreateReplacement(Tok.getLocation(), "class") 578 : FixItHint()); 579 } else if (Next.is(tok::identifier) || Next.is(tok::comma) || 580 Next.is(tok::greater) || Next.is(tok::greatergreater) || 581 Next.is(tok::ellipsis)) { 582 Diag(Tok.getLocation(), diag::err_class_on_template_template_param) 583 << (Replace ? FixItHint::CreateReplacement(Tok.getLocation(), "class") 584 : FixItHint::CreateInsertion(Tok.getLocation(), "class ")); 585 } else 586 Diag(Tok.getLocation(), diag::err_class_on_template_template_param); 587 588 if (Replace) 589 ConsumeToken(); 590 } 591 592 // Parse the ellipsis, if given. 593 SourceLocation EllipsisLoc; 594 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) 595 Diag(EllipsisLoc, 596 getLangOpts().CPlusPlus11 597 ? diag::warn_cxx98_compat_variadic_templates 598 : diag::ext_variadic_templates); 599 600 // Get the identifier, if given. 601 SourceLocation NameLoc; 602 IdentifierInfo *ParamName = nullptr; 603 if (Tok.is(tok::identifier)) { 604 ParamName = Tok.getIdentifierInfo(); 605 NameLoc = ConsumeToken(); 606 } else if (Tok.is(tok::equal) || Tok.is(tok::comma) || 607 Tok.is(tok::greater) || Tok.is(tok::greatergreater)) { 608 // Unnamed template parameter. Don't have to do anything here, just 609 // don't consume this token. 610 } else { 611 Diag(Tok.getLocation(), diag::err_expected) << tok::identifier; 612 return nullptr; 613 } 614 615 // Recover from misplaced ellipsis. 616 bool AlreadyHasEllipsis = EllipsisLoc.isValid(); 617 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) 618 DiagnoseMisplacedEllipsis(EllipsisLoc, NameLoc, AlreadyHasEllipsis, true); 619 620 TemplateParameterList *ParamList = 621 Actions.ActOnTemplateParameterList(Depth, SourceLocation(), 622 TemplateLoc, LAngleLoc, 623 TemplateParams.data(), 624 TemplateParams.size(), 625 RAngleLoc); 626 627 // Grab a default argument (if available). 628 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before 629 // we introduce the template parameter into the local scope. 630 SourceLocation EqualLoc; 631 ParsedTemplateArgument DefaultArg; 632 if (TryConsumeToken(tok::equal, EqualLoc)) { 633 DefaultArg = ParseTemplateTemplateArgument(); 634 if (DefaultArg.isInvalid()) { 635 Diag(Tok.getLocation(), 636 diag::err_default_template_template_parameter_not_template); 637 SkipUntil(tok::comma, tok::greater, tok::greatergreater, 638 StopAtSemi | StopBeforeMatch); 639 } 640 } 641 642 return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc, 643 ParamList, EllipsisLoc, 644 ParamName, NameLoc, Depth, 645 Position, EqualLoc, DefaultArg); 646 } 647 648 /// ParseNonTypeTemplateParameter - Handle the parsing of non-type 649 /// template parameters (e.g., in "template<int Size> class array;"). 650 /// 651 /// template-parameter: 652 /// ... 653 /// parameter-declaration 654 Decl * 655 Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) { 656 // Parse the declaration-specifiers (i.e., the type). 657 // FIXME: The type should probably be restricted in some way... Not all 658 // declarators (parts of declarators?) are accepted for parameters. 659 DeclSpec DS(AttrFactory); 660 ParseDeclarationSpecifiers(DS); 661 662 // Parse this as a typename. 663 Declarator ParamDecl(DS, Declarator::TemplateParamContext); 664 ParseDeclarator(ParamDecl); 665 if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) { 666 Diag(Tok.getLocation(), diag::err_expected_template_parameter); 667 return nullptr; 668 } 669 670 // Recover from misplaced ellipsis. 671 SourceLocation EllipsisLoc; 672 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) 673 DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, ParamDecl); 674 675 // If there is a default value, parse it. 676 // Per C++0x [basic.scope.pdecl]p9, we parse the default argument before 677 // we introduce the template parameter into the local scope. 678 SourceLocation EqualLoc; 679 ExprResult DefaultArg; 680 if (TryConsumeToken(tok::equal, EqualLoc)) { 681 // C++ [temp.param]p15: 682 // When parsing a default template-argument for a non-type 683 // template-parameter, the first non-nested > is taken as the 684 // end of the template-parameter-list rather than a greater-than 685 // operator. 686 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 687 EnterExpressionEvaluationContext Unevaluated(Actions, Sema::Unevaluated); 688 689 DefaultArg = Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression()); 690 if (DefaultArg.isInvalid()) 691 SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch); 692 } 693 694 // Create the parameter. 695 return Actions.ActOnNonTypeTemplateParameter(getCurScope(), ParamDecl, 696 Depth, Position, EqualLoc, 697 DefaultArg.get()); 698 } 699 700 void Parser::DiagnoseMisplacedEllipsis(SourceLocation EllipsisLoc, 701 SourceLocation CorrectLoc, 702 bool AlreadyHasEllipsis, 703 bool IdentifierHasName) { 704 FixItHint Insertion; 705 if (!AlreadyHasEllipsis) 706 Insertion = FixItHint::CreateInsertion(CorrectLoc, "..."); 707 Diag(EllipsisLoc, diag::err_misplaced_ellipsis_in_declaration) 708 << FixItHint::CreateRemoval(EllipsisLoc) << Insertion 709 << !IdentifierHasName; 710 } 711 712 void Parser::DiagnoseMisplacedEllipsisInDeclarator(SourceLocation EllipsisLoc, 713 Declarator &D) { 714 assert(EllipsisLoc.isValid()); 715 bool AlreadyHasEllipsis = D.getEllipsisLoc().isValid(); 716 if (!AlreadyHasEllipsis) 717 D.setEllipsisLoc(EllipsisLoc); 718 DiagnoseMisplacedEllipsis(EllipsisLoc, D.getIdentifierLoc(), 719 AlreadyHasEllipsis, D.hasName()); 720 } 721 722 /// \brief Parses a '>' at the end of a template list. 723 /// 724 /// If this function encounters '>>', '>>>', '>=', or '>>=', it tries 725 /// to determine if these tokens were supposed to be a '>' followed by 726 /// '>', '>>', '>=', or '>='. It emits an appropriate diagnostic if necessary. 727 /// 728 /// \param RAngleLoc the location of the consumed '>'. 729 /// 730 /// \param ConsumeLastToken if true, the '>' is not consumed. 731 /// 732 /// \returns true, if current token does not start with '>', false otherwise. 733 bool Parser::ParseGreaterThanInTemplateList(SourceLocation &RAngleLoc, 734 bool ConsumeLastToken) { 735 // What will be left once we've consumed the '>'. 736 tok::TokenKind RemainingToken; 737 const char *ReplacementStr = "> >"; 738 739 switch (Tok.getKind()) { 740 default: 741 Diag(Tok.getLocation(), diag::err_expected) << tok::greater; 742 return true; 743 744 case tok::greater: 745 // Determine the location of the '>' token. Only consume this token 746 // if the caller asked us to. 747 RAngleLoc = Tok.getLocation(); 748 if (ConsumeLastToken) 749 ConsumeToken(); 750 return false; 751 752 case tok::greatergreater: 753 RemainingToken = tok::greater; 754 break; 755 756 case tok::greatergreatergreater: 757 RemainingToken = tok::greatergreater; 758 break; 759 760 case tok::greaterequal: 761 RemainingToken = tok::equal; 762 ReplacementStr = "> ="; 763 break; 764 765 case tok::greatergreaterequal: 766 RemainingToken = tok::greaterequal; 767 break; 768 } 769 770 // This template-id is terminated by a token which starts with a '>'. Outside 771 // C++11, this is now error recovery, and in C++11, this is error recovery if 772 // the token isn't '>>' or '>>>'. 773 // '>>>' is for CUDA, where this sequence of characters is parsed into 774 // tok::greatergreatergreater, rather than two separate tokens. 775 776 RAngleLoc = Tok.getLocation(); 777 778 // The source range of the '>>' or '>=' at the start of the token. 779 CharSourceRange ReplacementRange = 780 CharSourceRange::getCharRange(RAngleLoc, 781 Lexer::AdvanceToTokenCharacter(RAngleLoc, 2, PP.getSourceManager(), 782 getLangOpts())); 783 784 // A hint to put a space between the '>>'s. In order to make the hint as 785 // clear as possible, we include the characters either side of the space in 786 // the replacement, rather than just inserting a space at SecondCharLoc. 787 FixItHint Hint1 = FixItHint::CreateReplacement(ReplacementRange, 788 ReplacementStr); 789 790 // A hint to put another space after the token, if it would otherwise be 791 // lexed differently. 792 FixItHint Hint2; 793 Token Next = NextToken(); 794 if ((RemainingToken == tok::greater || 795 RemainingToken == tok::greatergreater) && 796 (Next.is(tok::greater) || Next.is(tok::greatergreater) || 797 Next.is(tok::greatergreatergreater) || Next.is(tok::equal) || 798 Next.is(tok::greaterequal) || Next.is(tok::greatergreaterequal) || 799 Next.is(tok::equalequal)) && 800 areTokensAdjacent(Tok, Next)) 801 Hint2 = FixItHint::CreateInsertion(Next.getLocation(), " "); 802 803 unsigned DiagId = diag::err_two_right_angle_brackets_need_space; 804 if (getLangOpts().CPlusPlus11 && 805 (Tok.is(tok::greatergreater) || Tok.is(tok::greatergreatergreater))) 806 DiagId = diag::warn_cxx98_compat_two_right_angle_brackets; 807 else if (Tok.is(tok::greaterequal)) 808 DiagId = diag::err_right_angle_bracket_equal_needs_space; 809 Diag(Tok.getLocation(), DiagId) << Hint1 << Hint2; 810 811 // Strip the initial '>' from the token. 812 if (RemainingToken == tok::equal && Next.is(tok::equal) && 813 areTokensAdjacent(Tok, Next)) { 814 // Join two adjacent '=' tokens into one, for cases like: 815 // void (*p)() = f<int>; 816 // return f<int>==p; 817 ConsumeToken(); 818 Tok.setKind(tok::equalequal); 819 Tok.setLength(Tok.getLength() + 1); 820 } else { 821 Tok.setKind(RemainingToken); 822 Tok.setLength(Tok.getLength() - 1); 823 } 824 Tok.setLocation(Lexer::AdvanceToTokenCharacter(RAngleLoc, 1, 825 PP.getSourceManager(), 826 getLangOpts())); 827 828 if (!ConsumeLastToken) { 829 // Since we're not supposed to consume the '>' token, we need to push 830 // this token and revert the current token back to the '>'. 831 PP.EnterToken(Tok); 832 Tok.setKind(tok::greater); 833 Tok.setLength(1); 834 Tok.setLocation(RAngleLoc); 835 } 836 return false; 837 } 838 839 840 /// \brief Parses a template-id that after the template name has 841 /// already been parsed. 842 /// 843 /// This routine takes care of parsing the enclosed template argument 844 /// list ('<' template-parameter-list [opt] '>') and placing the 845 /// results into a form that can be transferred to semantic analysis. 846 /// 847 /// \param Template the template declaration produced by isTemplateName 848 /// 849 /// \param TemplateNameLoc the source location of the template name 850 /// 851 /// \param SS if non-NULL, the nested-name-specifier preceding the 852 /// template name. 853 /// 854 /// \param ConsumeLastToken if true, then we will consume the last 855 /// token that forms the template-id. Otherwise, we will leave the 856 /// last token in the stream (e.g., so that it can be replaced with an 857 /// annotation token). 858 bool 859 Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template, 860 SourceLocation TemplateNameLoc, 861 const CXXScopeSpec &SS, 862 bool ConsumeLastToken, 863 SourceLocation &LAngleLoc, 864 TemplateArgList &TemplateArgs, 865 SourceLocation &RAngleLoc) { 866 assert(Tok.is(tok::less) && "Must have already parsed the template-name"); 867 868 // Consume the '<'. 869 LAngleLoc = ConsumeToken(); 870 871 // Parse the optional template-argument-list. 872 bool Invalid = false; 873 { 874 GreaterThanIsOperatorScope G(GreaterThanIsOperator, false); 875 if (Tok.isNot(tok::greater) && Tok.isNot(tok::greatergreater)) 876 Invalid = ParseTemplateArgumentList(TemplateArgs); 877 878 if (Invalid) { 879 // Try to find the closing '>'. 880 if (ConsumeLastToken) 881 SkipUntil(tok::greater, StopAtSemi); 882 else 883 SkipUntil(tok::greater, StopAtSemi | StopBeforeMatch); 884 return true; 885 } 886 } 887 888 return ParseGreaterThanInTemplateList(RAngleLoc, ConsumeLastToken); 889 } 890 891 /// \brief Replace the tokens that form a simple-template-id with an 892 /// annotation token containing the complete template-id. 893 /// 894 /// The first token in the stream must be the name of a template that 895 /// is followed by a '<'. This routine will parse the complete 896 /// simple-template-id and replace the tokens with a single annotation 897 /// token with one of two different kinds: if the template-id names a 898 /// type (and \p AllowTypeAnnotation is true), the annotation token is 899 /// a type annotation that includes the optional nested-name-specifier 900 /// (\p SS). Otherwise, the annotation token is a template-id 901 /// annotation that does not include the optional 902 /// nested-name-specifier. 903 /// 904 /// \param Template the declaration of the template named by the first 905 /// token (an identifier), as returned from \c Action::isTemplateName(). 906 /// 907 /// \param TNK the kind of template that \p Template 908 /// refers to, as returned from \c Action::isTemplateName(). 909 /// 910 /// \param SS if non-NULL, the nested-name-specifier that precedes 911 /// this template name. 912 /// 913 /// \param TemplateKWLoc if valid, specifies that this template-id 914 /// annotation was preceded by the 'template' keyword and gives the 915 /// location of that keyword. If invalid (the default), then this 916 /// template-id was not preceded by a 'template' keyword. 917 /// 918 /// \param AllowTypeAnnotation if true (the default), then a 919 /// simple-template-id that refers to a class template, template 920 /// template parameter, or other template that produces a type will be 921 /// replaced with a type annotation token. Otherwise, the 922 /// simple-template-id is always replaced with a template-id 923 /// annotation token. 924 /// 925 /// If an unrecoverable parse error occurs and no annotation token can be 926 /// formed, this function returns true. 927 /// 928 bool Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK, 929 CXXScopeSpec &SS, 930 SourceLocation TemplateKWLoc, 931 UnqualifiedId &TemplateName, 932 bool AllowTypeAnnotation) { 933 assert(getLangOpts().CPlusPlus && "Can only annotate template-ids in C++"); 934 assert(Template && Tok.is(tok::less) && 935 "Parser isn't at the beginning of a template-id"); 936 937 // Consume the template-name. 938 SourceLocation TemplateNameLoc = TemplateName.getSourceRange().getBegin(); 939 940 // Parse the enclosed template argument list. 941 SourceLocation LAngleLoc, RAngleLoc; 942 TemplateArgList TemplateArgs; 943 bool Invalid = ParseTemplateIdAfterTemplateName(Template, 944 TemplateNameLoc, 945 SS, false, LAngleLoc, 946 TemplateArgs, 947 RAngleLoc); 948 949 if (Invalid) { 950 // If we failed to parse the template ID but skipped ahead to a >, we're not 951 // going to be able to form a token annotation. Eat the '>' if present. 952 TryConsumeToken(tok::greater); 953 return true; 954 } 955 956 ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs); 957 958 // Build the annotation token. 959 if (TNK == TNK_Type_template && AllowTypeAnnotation) { 960 TypeResult Type 961 = Actions.ActOnTemplateIdType(SS, TemplateKWLoc, 962 Template, TemplateNameLoc, 963 LAngleLoc, TemplateArgsPtr, RAngleLoc); 964 if (Type.isInvalid()) { 965 // If we failed to parse the template ID but skipped ahead to a >, we're not 966 // going to be able to form a token annotation. Eat the '>' if present. 967 TryConsumeToken(tok::greater); 968 return true; 969 } 970 971 Tok.setKind(tok::annot_typename); 972 setTypeAnnotation(Tok, Type.get()); 973 if (SS.isNotEmpty()) 974 Tok.setLocation(SS.getBeginLoc()); 975 else if (TemplateKWLoc.isValid()) 976 Tok.setLocation(TemplateKWLoc); 977 else 978 Tok.setLocation(TemplateNameLoc); 979 } else { 980 // Build a template-id annotation token that can be processed 981 // later. 982 Tok.setKind(tok::annot_template_id); 983 TemplateIdAnnotation *TemplateId 984 = TemplateIdAnnotation::Allocate(TemplateArgs.size(), TemplateIds); 985 TemplateId->TemplateNameLoc = TemplateNameLoc; 986 if (TemplateName.getKind() == UnqualifiedId::IK_Identifier) { 987 TemplateId->Name = TemplateName.Identifier; 988 TemplateId->Operator = OO_None; 989 } else { 990 TemplateId->Name = nullptr; 991 TemplateId->Operator = TemplateName.OperatorFunctionId.Operator; 992 } 993 TemplateId->SS = SS; 994 TemplateId->TemplateKWLoc = TemplateKWLoc; 995 TemplateId->Template = Template; 996 TemplateId->Kind = TNK; 997 TemplateId->LAngleLoc = LAngleLoc; 998 TemplateId->RAngleLoc = RAngleLoc; 999 ParsedTemplateArgument *Args = TemplateId->getTemplateArgs(); 1000 for (unsigned Arg = 0, ArgEnd = TemplateArgs.size(); Arg != ArgEnd; ++Arg) 1001 Args[Arg] = ParsedTemplateArgument(TemplateArgs[Arg]); 1002 Tok.setAnnotationValue(TemplateId); 1003 if (TemplateKWLoc.isValid()) 1004 Tok.setLocation(TemplateKWLoc); 1005 else 1006 Tok.setLocation(TemplateNameLoc); 1007 } 1008 1009 // Common fields for the annotation token 1010 Tok.setAnnotationEndLoc(RAngleLoc); 1011 1012 // In case the tokens were cached, have Preprocessor replace them with the 1013 // annotation token. 1014 PP.AnnotateCachedTokens(Tok); 1015 return false; 1016 } 1017 1018 /// \brief Replaces a template-id annotation token with a type 1019 /// annotation token. 1020 /// 1021 /// If there was a failure when forming the type from the template-id, 1022 /// a type annotation token will still be created, but will have a 1023 /// NULL type pointer to signify an error. 1024 void Parser::AnnotateTemplateIdTokenAsType() { 1025 assert(Tok.is(tok::annot_template_id) && "Requires template-id tokens"); 1026 1027 TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok); 1028 assert((TemplateId->Kind == TNK_Type_template || 1029 TemplateId->Kind == TNK_Dependent_template_name) && 1030 "Only works for type and dependent templates"); 1031 1032 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 1033 TemplateId->NumArgs); 1034 1035 TypeResult Type 1036 = Actions.ActOnTemplateIdType(TemplateId->SS, 1037 TemplateId->TemplateKWLoc, 1038 TemplateId->Template, 1039 TemplateId->TemplateNameLoc, 1040 TemplateId->LAngleLoc, 1041 TemplateArgsPtr, 1042 TemplateId->RAngleLoc); 1043 // Create the new "type" annotation token. 1044 Tok.setKind(tok::annot_typename); 1045 setTypeAnnotation(Tok, Type.isInvalid() ? ParsedType() : Type.get()); 1046 if (TemplateId->SS.isNotEmpty()) // it was a C++ qualified type name. 1047 Tok.setLocation(TemplateId->SS.getBeginLoc()); 1048 // End location stays the same 1049 1050 // Replace the template-id annotation token, and possible the scope-specifier 1051 // that precedes it, with the typename annotation token. 1052 PP.AnnotateCachedTokens(Tok); 1053 } 1054 1055 /// \brief Determine whether the given token can end a template argument. 1056 static bool isEndOfTemplateArgument(Token Tok) { 1057 return Tok.is(tok::comma) || Tok.is(tok::greater) || 1058 Tok.is(tok::greatergreater); 1059 } 1060 1061 /// \brief Parse a C++ template template argument. 1062 ParsedTemplateArgument Parser::ParseTemplateTemplateArgument() { 1063 if (!Tok.is(tok::identifier) && !Tok.is(tok::coloncolon) && 1064 !Tok.is(tok::annot_cxxscope)) 1065 return ParsedTemplateArgument(); 1066 1067 // C++0x [temp.arg.template]p1: 1068 // A template-argument for a template template-parameter shall be the name 1069 // of a class template or an alias template, expressed as id-expression. 1070 // 1071 // We parse an id-expression that refers to a class template or alias 1072 // template. The grammar we parse is: 1073 // 1074 // nested-name-specifier[opt] template[opt] identifier ...[opt] 1075 // 1076 // followed by a token that terminates a template argument, such as ',', 1077 // '>', or (in some cases) '>>'. 1078 CXXScopeSpec SS; // nested-name-specifier, if present 1079 ParseOptionalCXXScopeSpecifier(SS, ParsedType(), 1080 /*EnteringContext=*/false); 1081 1082 ParsedTemplateArgument Result; 1083 SourceLocation EllipsisLoc; 1084 if (SS.isSet() && Tok.is(tok::kw_template)) { 1085 // Parse the optional 'template' keyword following the 1086 // nested-name-specifier. 1087 SourceLocation TemplateKWLoc = ConsumeToken(); 1088 1089 if (Tok.is(tok::identifier)) { 1090 // We appear to have a dependent template name. 1091 UnqualifiedId Name; 1092 Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); 1093 ConsumeToken(); // the identifier 1094 1095 TryConsumeToken(tok::ellipsis, EllipsisLoc); 1096 1097 // If the next token signals the end of a template argument, 1098 // then we have a dependent template name that could be a template 1099 // template argument. 1100 TemplateTy Template; 1101 if (isEndOfTemplateArgument(Tok) && 1102 Actions.ActOnDependentTemplateName(getCurScope(), 1103 SS, TemplateKWLoc, Name, 1104 /*ObjectType=*/ ParsedType(), 1105 /*EnteringContext=*/false, 1106 Template)) 1107 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation); 1108 } 1109 } else if (Tok.is(tok::identifier)) { 1110 // We may have a (non-dependent) template name. 1111 TemplateTy Template; 1112 UnqualifiedId Name; 1113 Name.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); 1114 ConsumeToken(); // the identifier 1115 1116 TryConsumeToken(tok::ellipsis, EllipsisLoc); 1117 1118 if (isEndOfTemplateArgument(Tok)) { 1119 bool MemberOfUnknownSpecialization; 1120 TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS, 1121 /*hasTemplateKeyword=*/false, 1122 Name, 1123 /*ObjectType=*/ ParsedType(), 1124 /*EnteringContext=*/false, 1125 Template, 1126 MemberOfUnknownSpecialization); 1127 if (TNK == TNK_Dependent_template_name || TNK == TNK_Type_template) { 1128 // We have an id-expression that refers to a class template or 1129 // (C++0x) alias template. 1130 Result = ParsedTemplateArgument(SS, Template, Name.StartLocation); 1131 } 1132 } 1133 } 1134 1135 // If this is a pack expansion, build it as such. 1136 if (EllipsisLoc.isValid() && !Result.isInvalid()) 1137 Result = Actions.ActOnPackExpansion(Result, EllipsisLoc); 1138 1139 return Result; 1140 } 1141 1142 /// ParseTemplateArgument - Parse a C++ template argument (C++ [temp.names]). 1143 /// 1144 /// template-argument: [C++ 14.2] 1145 /// constant-expression 1146 /// type-id 1147 /// id-expression 1148 ParsedTemplateArgument Parser::ParseTemplateArgument() { 1149 // C++ [temp.arg]p2: 1150 // In a template-argument, an ambiguity between a type-id and an 1151 // expression is resolved to a type-id, regardless of the form of 1152 // the corresponding template-parameter. 1153 // 1154 // Therefore, we initially try to parse a type-id. 1155 if (isCXXTypeId(TypeIdAsTemplateArgument)) { 1156 SourceLocation Loc = Tok.getLocation(); 1157 TypeResult TypeArg = ParseTypeName(/*Range=*/nullptr, 1158 Declarator::TemplateTypeArgContext); 1159 if (TypeArg.isInvalid()) 1160 return ParsedTemplateArgument(); 1161 1162 return ParsedTemplateArgument(ParsedTemplateArgument::Type, 1163 TypeArg.get().getAsOpaquePtr(), 1164 Loc); 1165 } 1166 1167 // Try to parse a template template argument. 1168 { 1169 TentativeParsingAction TPA(*this); 1170 1171 ParsedTemplateArgument TemplateTemplateArgument 1172 = ParseTemplateTemplateArgument(); 1173 if (!TemplateTemplateArgument.isInvalid()) { 1174 TPA.Commit(); 1175 return TemplateTemplateArgument; 1176 } 1177 1178 // Revert this tentative parse to parse a non-type template argument. 1179 TPA.Revert(); 1180 } 1181 1182 // Parse a non-type template argument. 1183 SourceLocation Loc = Tok.getLocation(); 1184 ExprResult ExprArg = ParseConstantExpression(MaybeTypeCast); 1185 if (ExprArg.isInvalid() || !ExprArg.get()) 1186 return ParsedTemplateArgument(); 1187 1188 return ParsedTemplateArgument(ParsedTemplateArgument::NonType, 1189 ExprArg.get(), Loc); 1190 } 1191 1192 /// \brief Determine whether the current tokens can only be parsed as a 1193 /// template argument list (starting with the '<') and never as a '<' 1194 /// expression. 1195 bool Parser::IsTemplateArgumentList(unsigned Skip) { 1196 struct AlwaysRevertAction : TentativeParsingAction { 1197 AlwaysRevertAction(Parser &P) : TentativeParsingAction(P) { } 1198 ~AlwaysRevertAction() { Revert(); } 1199 } Tentative(*this); 1200 1201 while (Skip) { 1202 ConsumeToken(); 1203 --Skip; 1204 } 1205 1206 // '<' 1207 if (!TryConsumeToken(tok::less)) 1208 return false; 1209 1210 // An empty template argument list. 1211 if (Tok.is(tok::greater)) 1212 return true; 1213 1214 // See whether we have declaration specifiers, which indicate a type. 1215 while (isCXXDeclarationSpecifier() == TPResult::True) 1216 ConsumeToken(); 1217 1218 // If we have a '>' or a ',' then this is a template argument list. 1219 return Tok.is(tok::greater) || Tok.is(tok::comma); 1220 } 1221 1222 /// ParseTemplateArgumentList - Parse a C++ template-argument-list 1223 /// (C++ [temp.names]). Returns true if there was an error. 1224 /// 1225 /// template-argument-list: [C++ 14.2] 1226 /// template-argument 1227 /// template-argument-list ',' template-argument 1228 bool 1229 Parser::ParseTemplateArgumentList(TemplateArgList &TemplateArgs) { 1230 // Template argument lists are constant-evaluation contexts. 1231 EnterExpressionEvaluationContext EvalContext(Actions,Sema::ConstantEvaluated); 1232 ColonProtectionRAIIObject ColonProtection(*this, false); 1233 1234 do { 1235 ParsedTemplateArgument Arg = ParseTemplateArgument(); 1236 SourceLocation EllipsisLoc; 1237 if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) 1238 Arg = Actions.ActOnPackExpansion(Arg, EllipsisLoc); 1239 1240 if (Arg.isInvalid()) { 1241 SkipUntil(tok::comma, tok::greater, StopAtSemi | StopBeforeMatch); 1242 return true; 1243 } 1244 1245 // Save this template argument. 1246 TemplateArgs.push_back(Arg); 1247 1248 // If the next token is a comma, consume it and keep reading 1249 // arguments. 1250 } while (TryConsumeToken(tok::comma)); 1251 1252 return false; 1253 } 1254 1255 /// \brief Parse a C++ explicit template instantiation 1256 /// (C++ [temp.explicit]). 1257 /// 1258 /// explicit-instantiation: 1259 /// 'extern' [opt] 'template' declaration 1260 /// 1261 /// Note that the 'extern' is a GNU extension and C++11 feature. 1262 Decl *Parser::ParseExplicitInstantiation(unsigned Context, 1263 SourceLocation ExternLoc, 1264 SourceLocation TemplateLoc, 1265 SourceLocation &DeclEnd, 1266 AccessSpecifier AS) { 1267 // This isn't really required here. 1268 ParsingDeclRAIIObject 1269 ParsingTemplateParams(*this, ParsingDeclRAIIObject::NoParent); 1270 1271 return ParseSingleDeclarationAfterTemplate(Context, 1272 ParsedTemplateInfo(ExternLoc, 1273 TemplateLoc), 1274 ParsingTemplateParams, 1275 DeclEnd, AS); 1276 } 1277 1278 SourceRange Parser::ParsedTemplateInfo::getSourceRange() const { 1279 if (TemplateParams) 1280 return getTemplateParamsRange(TemplateParams->data(), 1281 TemplateParams->size()); 1282 1283 SourceRange R(TemplateLoc); 1284 if (ExternLoc.isValid()) 1285 R.setBegin(ExternLoc); 1286 return R; 1287 } 1288 1289 void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) { 1290 ((Parser *)P)->ParseLateTemplatedFuncDef(LPT); 1291 } 1292 1293 /// \brief Late parse a C++ function template in Microsoft mode. 1294 void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) { 1295 if (!LPT.D) 1296 return; 1297 1298 // Get the FunctionDecl. 1299 FunctionDecl *FunD = LPT.D->getAsFunction(); 1300 // Track template parameter depth. 1301 TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth); 1302 1303 // To restore the context after late parsing. 1304 Sema::ContextRAII GlobalSavedContext(Actions, Actions.CurContext); 1305 1306 SmallVector<ParseScope*, 4> TemplateParamScopeStack; 1307 1308 // Get the list of DeclContexts to reenter. 1309 SmallVector<DeclContext*, 4> DeclContextsToReenter; 1310 DeclContext *DD = FunD; 1311 while (DD && !DD->isTranslationUnit()) { 1312 DeclContextsToReenter.push_back(DD); 1313 DD = DD->getLexicalParent(); 1314 } 1315 1316 // Reenter template scopes from outermost to innermost. 1317 SmallVectorImpl<DeclContext *>::reverse_iterator II = 1318 DeclContextsToReenter.rbegin(); 1319 for (; II != DeclContextsToReenter.rend(); ++II) { 1320 TemplateParamScopeStack.push_back(new ParseScope(this, 1321 Scope::TemplateParamScope)); 1322 unsigned NumParamLists = 1323 Actions.ActOnReenterTemplateScope(getCurScope(), cast<Decl>(*II)); 1324 CurTemplateDepthTracker.addDepth(NumParamLists); 1325 if (*II != FunD) { 1326 TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope)); 1327 Actions.PushDeclContext(Actions.getCurScope(), *II); 1328 } 1329 } 1330 1331 assert(!LPT.Toks.empty() && "Empty body!"); 1332 1333 // Append the current token at the end of the new token stream so that it 1334 // doesn't get lost. 1335 LPT.Toks.push_back(Tok); 1336 PP.EnterTokenStream(LPT.Toks.data(), LPT.Toks.size(), true, false); 1337 1338 // Consume the previously pushed token. 1339 ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true); 1340 assert((Tok.is(tok::l_brace) || Tok.is(tok::colon) || Tok.is(tok::kw_try)) 1341 && "Inline method not starting with '{', ':' or 'try'"); 1342 1343 // Parse the method body. Function body parsing code is similar enough 1344 // to be re-used for method bodies as well. 1345 ParseScope FnScope(this, Scope::FnScope|Scope::DeclScope); 1346 1347 // Recreate the containing function DeclContext. 1348 Sema::ContextRAII FunctionSavedContext(Actions, 1349 Actions.getContainingDC(FunD)); 1350 1351 Actions.ActOnStartOfFunctionDef(getCurScope(), FunD); 1352 1353 if (Tok.is(tok::kw_try)) { 1354 ParseFunctionTryBlock(LPT.D, FnScope); 1355 } else { 1356 if (Tok.is(tok::colon)) 1357 ParseConstructorInitializer(LPT.D); 1358 else 1359 Actions.ActOnDefaultCtorInitializers(LPT.D); 1360 1361 if (Tok.is(tok::l_brace)) { 1362 assert((!isa<FunctionTemplateDecl>(LPT.D) || 1363 cast<FunctionTemplateDecl>(LPT.D) 1364 ->getTemplateParameters() 1365 ->getDepth() == TemplateParameterDepth - 1) && 1366 "TemplateParameterDepth should be greater than the depth of " 1367 "current template being instantiated!"); 1368 ParseFunctionStatementBody(LPT.D, FnScope); 1369 Actions.UnmarkAsLateParsedTemplate(FunD); 1370 } else 1371 Actions.ActOnFinishFunctionBody(LPT.D, nullptr); 1372 } 1373 1374 // Exit scopes. 1375 FnScope.Exit(); 1376 SmallVectorImpl<ParseScope *>::reverse_iterator I = 1377 TemplateParamScopeStack.rbegin(); 1378 for (; I != TemplateParamScopeStack.rend(); ++I) 1379 delete *I; 1380 } 1381 1382 /// \brief Lex a delayed template function for late parsing. 1383 void Parser::LexTemplateFunctionForLateParsing(CachedTokens &Toks) { 1384 tok::TokenKind kind = Tok.getKind(); 1385 if (!ConsumeAndStoreFunctionPrologue(Toks)) { 1386 // Consume everything up to (and including) the matching right brace. 1387 ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false); 1388 } 1389 1390 // If we're in a function-try-block, we need to store all the catch blocks. 1391 if (kind == tok::kw_try) { 1392 while (Tok.is(tok::kw_catch)) { 1393 ConsumeAndStoreUntil(tok::l_brace, Toks, /*StopAtSemi=*/false); 1394 ConsumeAndStoreUntil(tok::r_brace, Toks, /*StopAtSemi=*/false); 1395 } 1396 } 1397 } 1398