Parser.cpp revision 5e02c47a7085831586344a9728763cb50540c7f7
1//===--- Parser.cpp - C Language Family Parser ----------------------------===// 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 the Parser interfaces. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Parse/Parser.h" 15#include "clang/Basic/Diagnostic.h" 16#include "clang/Parse/DeclSpec.h" 17#include "clang/Parse/Scope.h" 18#include "ExtensionRAIIObject.h" 19#include "ParsePragma.h" 20using namespace clang; 21 22Parser::Parser(Preprocessor &pp, Action &actions) 23 : PP(pp), Actions(actions), Diags(PP.getDiagnostics()) { 24 Tok.setKind(tok::eof); 25 CurScope = 0; 26 NumCachedScopes = 0; 27 ParenCount = BracketCount = BraceCount = 0; 28 ObjCImpDecl = 0; 29 30 // Add #pragma handlers. These are removed and destroyed in the 31 // destructor. 32 PackHandler = 33 new PragmaPackHandler(&PP.getIdentifierTable().get("pack"), actions); 34 PP.AddPragmaHandler(0, PackHandler); 35 36 // Instantiate a LexedMethodsForTopClass for all the non-nested classes. 37 PushTopClassStack(); 38} 39 40/// Out-of-line virtual destructor to provide home for Action class. 41ActionBase::~ActionBase() {} 42 43/// Out-of-line virtual destructor to provide home for Action class. 44Action::~Action() {} 45 46// Defined out-of-line here because of dependecy on AttributeList 47Action::DeclTy *Action::ActOnUsingDirective(Scope *CurScope, 48 SourceLocation UsingLoc, 49 SourceLocation NamespcLoc, 50 const CXXScopeSpec &SS, 51 SourceLocation IdentLoc, 52 IdentifierInfo *NamespcName, 53 AttributeList *AttrList) { 54 55 // FIXME: Parser seems to assume that Action::ActOn* takes ownership over 56 // passed AttributeList, however other actions don't free it, is it 57 // temporary state or bug? 58 delete AttrList; 59 return 0; 60} 61 62DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) { 63 return Diags.Report(FullSourceLoc(Loc,PP.getSourceManager()), DiagID); 64} 65 66DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) { 67 return Diag(Tok.getLocation(), DiagID); 68} 69 70/// MatchRHSPunctuation - For punctuation with a LHS and RHS (e.g. '['/']'), 71/// this helper function matches and consumes the specified RHS token if 72/// present. If not present, it emits the specified diagnostic indicating 73/// that the parser failed to match the RHS of the token at LHSLoc. LHSName 74/// should be the name of the unmatched LHS token. 75SourceLocation Parser::MatchRHSPunctuation(tok::TokenKind RHSTok, 76 SourceLocation LHSLoc) { 77 78 if (Tok.is(RHSTok)) 79 return ConsumeAnyToken(); 80 81 SourceLocation R = Tok.getLocation(); 82 const char *LHSName = "unknown"; 83 diag::kind DID = diag::err_parse_error; 84 switch (RHSTok) { 85 default: break; 86 case tok::r_paren : LHSName = "("; DID = diag::err_expected_rparen; break; 87 case tok::r_brace : LHSName = "{"; DID = diag::err_expected_rbrace; break; 88 case tok::r_square: LHSName = "["; DID = diag::err_expected_rsquare; break; 89 case tok::greater: LHSName = "<"; DID = diag::err_expected_greater; break; 90 } 91 Diag(Tok, DID); 92 Diag(LHSLoc, diag::note_matching) << LHSName; 93 SkipUntil(RHSTok); 94 return R; 95} 96 97/// ExpectAndConsume - The parser expects that 'ExpectedTok' is next in the 98/// input. If so, it is consumed and false is returned. 99/// 100/// If the input is malformed, this emits the specified diagnostic. Next, if 101/// SkipToTok is specified, it calls SkipUntil(SkipToTok). Finally, true is 102/// returned. 103bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID, 104 const char *Msg, tok::TokenKind SkipToTok) { 105 if (Tok.is(ExpectedTok)) { 106 ConsumeAnyToken(); 107 return false; 108 } 109 110 Diag(Tok, DiagID) << Msg; 111 if (SkipToTok != tok::unknown) 112 SkipUntil(SkipToTok); 113 return true; 114} 115 116//===----------------------------------------------------------------------===// 117// Error recovery. 118//===----------------------------------------------------------------------===// 119 120/// SkipUntil - Read tokens until we get to the specified token, then consume 121/// it (unless DontConsume is true). Because we cannot guarantee that the 122/// token will ever occur, this skips to the next token, or to some likely 123/// good stopping point. If StopAtSemi is true, skipping will stop at a ';' 124/// character. 125/// 126/// If SkipUntil finds the specified token, it returns true, otherwise it 127/// returns false. 128bool Parser::SkipUntil(const tok::TokenKind *Toks, unsigned NumToks, 129 bool StopAtSemi, bool DontConsume) { 130 // We always want this function to skip at least one token if the first token 131 // isn't T and if not at EOF. 132 bool isFirstTokenSkipped = true; 133 while (1) { 134 // If we found one of the tokens, stop and return true. 135 for (unsigned i = 0; i != NumToks; ++i) { 136 if (Tok.is(Toks[i])) { 137 if (DontConsume) { 138 // Noop, don't consume the token. 139 } else { 140 ConsumeAnyToken(); 141 } 142 return true; 143 } 144 } 145 146 switch (Tok.getKind()) { 147 case tok::eof: 148 // Ran out of tokens. 149 return false; 150 151 case tok::l_paren: 152 // Recursively skip properly-nested parens. 153 ConsumeParen(); 154 SkipUntil(tok::r_paren, false); 155 break; 156 case tok::l_square: 157 // Recursively skip properly-nested square brackets. 158 ConsumeBracket(); 159 SkipUntil(tok::r_square, false); 160 break; 161 case tok::l_brace: 162 // Recursively skip properly-nested braces. 163 ConsumeBrace(); 164 SkipUntil(tok::r_brace, false); 165 break; 166 167 // Okay, we found a ']' or '}' or ')', which we think should be balanced. 168 // Since the user wasn't looking for this token (if they were, it would 169 // already be handled), this isn't balanced. If there is a LHS token at a 170 // higher level, we will assume that this matches the unbalanced token 171 // and return it. Otherwise, this is a spurious RHS token, which we skip. 172 case tok::r_paren: 173 if (ParenCount && !isFirstTokenSkipped) 174 return false; // Matches something. 175 ConsumeParen(); 176 break; 177 case tok::r_square: 178 if (BracketCount && !isFirstTokenSkipped) 179 return false; // Matches something. 180 ConsumeBracket(); 181 break; 182 case tok::r_brace: 183 if (BraceCount && !isFirstTokenSkipped) 184 return false; // Matches something. 185 ConsumeBrace(); 186 break; 187 188 case tok::string_literal: 189 case tok::wide_string_literal: 190 ConsumeStringToken(); 191 break; 192 case tok::semi: 193 if (StopAtSemi) 194 return false; 195 // FALL THROUGH. 196 default: 197 // Skip this token. 198 ConsumeToken(); 199 break; 200 } 201 isFirstTokenSkipped = false; 202 } 203} 204 205//===----------------------------------------------------------------------===// 206// Scope manipulation 207//===----------------------------------------------------------------------===// 208 209/// EnterScope - Start a new scope. 210void Parser::EnterScope(unsigned ScopeFlags) { 211 if (NumCachedScopes) { 212 Scope *N = ScopeCache[--NumCachedScopes]; 213 N->Init(CurScope, ScopeFlags); 214 CurScope = N; 215 } else { 216 CurScope = new Scope(CurScope, ScopeFlags); 217 } 218} 219 220/// ExitScope - Pop a scope off the scope stack. 221void Parser::ExitScope() { 222 assert(CurScope && "Scope imbalance!"); 223 224 // Inform the actions module that this scope is going away if there are any 225 // decls in it. 226 if (!CurScope->decl_empty()) 227 Actions.ActOnPopScope(Tok.getLocation(), CurScope); 228 229 Scope *OldScope = CurScope; 230 CurScope = OldScope->getParent(); 231 232 if (NumCachedScopes == ScopeCacheSize) 233 delete OldScope; 234 else 235 ScopeCache[NumCachedScopes++] = OldScope; 236} 237 238 239 240 241//===----------------------------------------------------------------------===// 242// C99 6.9: External Definitions. 243//===----------------------------------------------------------------------===// 244 245Parser::~Parser() { 246 // If we still have scopes active, delete the scope tree. 247 delete CurScope; 248 249 // Free the scope cache. 250 for (unsigned i = 0, e = NumCachedScopes; i != e; ++i) 251 delete ScopeCache[i]; 252 253 // Remove the pragma handlers we installed. 254 PP.RemovePragmaHandler(0, PackHandler); 255 delete PackHandler; 256} 257 258/// Initialize - Warm up the parser. 259/// 260void Parser::Initialize() { 261 // Prime the lexer look-ahead. 262 ConsumeToken(); 263 264 // Create the translation unit scope. Install it as the current scope. 265 assert(CurScope == 0 && "A scope is already active?"); 266 EnterScope(Scope::DeclScope); 267 Actions.ActOnTranslationUnitScope(Tok.getLocation(), CurScope); 268 269 if (Tok.is(tok::eof) && 270 !getLang().CPlusPlus) // Empty source file is an extension in C 271 Diag(Tok, diag::ext_empty_source_file); 272 273 // Initialization for Objective-C context sensitive keywords recognition. 274 // Referenced in Parser::ParseObjCTypeQualifierList. 275 if (getLang().ObjC1) { 276 ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in"); 277 ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out"); 278 ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout"); 279 ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway"); 280 ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy"); 281 ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref"); 282 } 283 284 Ident_super = &PP.getIdentifierTable().get("super"); 285} 286 287/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the 288/// action tells us to. This returns true if the EOF was encountered. 289bool Parser::ParseTopLevelDecl(DeclTy*& Result) { 290 Result = 0; 291 if (Tok.is(tok::eof)) { 292 Actions.ActOnEndOfTranslationUnit(); 293 return true; 294 } 295 296 Result = ParseExternalDeclaration(); 297 return false; 298} 299 300/// ParseTranslationUnit: 301/// translation-unit: [C99 6.9] 302/// external-declaration 303/// translation-unit external-declaration 304void Parser::ParseTranslationUnit() { 305 Initialize(); 306 307 DeclTy *Res; 308 while (!ParseTopLevelDecl(Res)) 309 /*parse them all*/; 310 311 ExitScope(); 312 assert(CurScope == 0 && "Scope imbalance!"); 313} 314 315/// ParseExternalDeclaration: 316/// 317/// external-declaration: [C99 6.9], declaration: [C++ dcl.dcl] 318/// function-definition 319/// declaration 320/// [EXT] ';' 321/// [GNU] asm-definition 322/// [GNU] __extension__ external-declaration 323/// [OBJC] objc-class-definition 324/// [OBJC] objc-class-declaration 325/// [OBJC] objc-alias-declaration 326/// [OBJC] objc-protocol-definition 327/// [OBJC] objc-method-definition 328/// [OBJC] @end 329/// [C++] linkage-specification 330/// [GNU] asm-definition: 331/// simple-asm-expr ';' 332/// 333Parser::DeclTy *Parser::ParseExternalDeclaration() { 334 switch (Tok.getKind()) { 335 case tok::semi: 336 Diag(Tok, diag::ext_top_level_semi); 337 ConsumeToken(); 338 // TODO: Invoke action for top-level semicolon. 339 return 0; 340 case tok::r_brace: 341 Diag(Tok, diag::err_expected_external_declaration); 342 ConsumeBrace(); 343 return 0; 344 case tok::eof: 345 Diag(Tok, diag::err_expected_external_declaration); 346 return 0; 347 case tok::kw___extension__: { 348 // __extension__ silences extension warnings in the subexpression. 349 ExtensionRAIIObject O(Diags); // Use RAII to do this. 350 ConsumeToken(); 351 return ParseExternalDeclaration(); 352 } 353 case tok::kw_asm: { 354 OwningExprResult Result(ParseSimpleAsm()); 355 356 ExpectAndConsume(tok::semi, diag::err_expected_semi_after, 357 "top-level asm block"); 358 359 if (!Result.isInvalid()) 360 return Actions.ActOnFileScopeAsmDecl(Tok.getLocation(), 361 move_convert(Result)); 362 return 0; 363 } 364 case tok::at: 365 // @ is not a legal token unless objc is enabled, no need to check. 366 return ParseObjCAtDirectives(); 367 case tok::minus: 368 case tok::plus: 369 if (getLang().ObjC1) 370 return ParseObjCMethodDefinition(); 371 else { 372 Diag(Tok, diag::err_expected_external_declaration); 373 ConsumeToken(); 374 } 375 return 0; 376 case tok::kw_using: 377 case tok::kw_namespace: 378 case tok::kw_typedef: 379 case tok::kw_template: 380 case tok::kw_export: // As in 'export template' 381 // A function definition cannot start with a these keywords. 382 return ParseDeclaration(Declarator::FileContext); 383 384 default: 385 // We can't tell whether this is a function-definition or declaration yet. 386 return ParseDeclarationOrFunctionDefinition(); 387 } 388} 389 390/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or 391/// a declaration. We can't tell which we have until we read up to the 392/// compound-statement in function-definition. TemplateParams, if 393/// non-NULL, provides the template parameters when we're parsing a 394/// C++ template-declaration. 395/// 396/// function-definition: [C99 6.9.1] 397/// decl-specs declarator declaration-list[opt] compound-statement 398/// [C90] function-definition: [C99 6.7.1] - implicit int result 399/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 400/// 401/// declaration: [C99 6.7] 402/// declaration-specifiers init-declarator-list[opt] ';' 403/// [!C99] init-declarator-list ';' [TODO: warn in c99 mode] 404/// [OMP] threadprivate-directive [TODO] 405/// 406Parser::DeclTy * 407Parser::ParseDeclarationOrFunctionDefinition( 408 TemplateParameterLists *TemplateParams) { 409 // Parse the common declaration-specifiers piece. 410 DeclSpec DS; 411 ParseDeclarationSpecifiers(DS, TemplateParams); 412 413 // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };" 414 // declaration-specifiers init-declarator-list[opt] ';' 415 if (Tok.is(tok::semi)) { 416 ConsumeToken(); 417 return Actions.ParsedFreeStandingDeclSpec(CurScope, DS); 418 } 419 420 // ObjC2 allows prefix attributes on class interfaces and protocols. 421 // FIXME: This still needs better diagnostics. We should only accept 422 // attributes here, no types, etc. 423 if (getLang().ObjC2 && Tok.is(tok::at)) { 424 SourceLocation AtLoc = ConsumeToken(); // the "@" 425 if (!Tok.isObjCAtKeyword(tok::objc_interface) && 426 !Tok.isObjCAtKeyword(tok::objc_protocol)) { 427 Diag(Tok, diag::err_objc_unexpected_attr); 428 SkipUntil(tok::semi); // FIXME: better skip? 429 return 0; 430 } 431 const char *PrevSpec = 0; 432 if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec)) 433 Diag(AtLoc, diag::err_invalid_decl_spec_combination) << PrevSpec; 434 if (Tok.isObjCAtKeyword(tok::objc_protocol)) 435 return ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes()); 436 return ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()); 437 } 438 439 // If the declspec consisted only of 'extern' and we have a string 440 // literal following it, this must be a C++ linkage specifier like 441 // 'extern "C"'. 442 if (Tok.is(tok::string_literal) && getLang().CPlusPlus && 443 DS.getStorageClassSpec() == DeclSpec::SCS_extern && 444 DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) 445 return ParseLinkage(Declarator::FileContext); 446 447 // Parse the first declarator. 448 Declarator DeclaratorInfo(DS, Declarator::FileContext); 449 ParseDeclarator(DeclaratorInfo); 450 // Error parsing the declarator? 451 if (!DeclaratorInfo.hasName()) { 452 // If so, skip until the semi-colon or a }. 453 SkipUntil(tok::r_brace, true, true); 454 if (Tok.is(tok::semi)) 455 ConsumeToken(); 456 return 0; 457 } 458 459 // If the declarator is the start of a function definition, handle it. 460 if (Tok.is(tok::equal) || // int X()= -> not a function def 461 Tok.is(tok::comma) || // int X(), -> not a function def 462 Tok.is(tok::semi) || // int X(); -> not a function def 463 Tok.is(tok::kw_asm) || // int X() __asm__ -> not a function def 464 Tok.is(tok::kw___attribute) || // int X() __attr__ -> not a function def 465 (getLang().CPlusPlus && 466 Tok.is(tok::l_paren)) ) { // int X(0) -> not a function def [C++] 467 // FALL THROUGH. 468 } else if (DeclaratorInfo.isFunctionDeclarator() && 469 (Tok.is(tok::l_brace) || // int X() {} 470 ( !getLang().CPlusPlus && 471 isDeclarationSpecifier() ))) { // int X(f) int f; {} 472 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) { 473 Diag(Tok, diag::err_function_declared_typedef); 474 475 if (Tok.is(tok::l_brace)) { 476 // This recovery skips the entire function body. It would be nice 477 // to simply call ParseFunctionDefinition() below, however Sema 478 // assumes the declarator represents a function, not a typedef. 479 ConsumeBrace(); 480 SkipUntil(tok::r_brace, true); 481 } else { 482 SkipUntil(tok::semi); 483 } 484 return 0; 485 } 486 return ParseFunctionDefinition(DeclaratorInfo); 487 } else { 488 if (DeclaratorInfo.isFunctionDeclarator()) 489 Diag(Tok, diag::err_expected_fn_body); 490 else 491 Diag(Tok, diag::err_expected_after_declarator); 492 SkipUntil(tok::semi); 493 return 0; 494 } 495 496 // Parse the init-declarator-list for a normal declaration. 497 return ParseInitDeclaratorListAfterFirstDeclarator(DeclaratorInfo); 498} 499 500/// ParseFunctionDefinition - We parsed and verified that the specified 501/// Declarator is well formed. If this is a K&R-style function, read the 502/// parameters declaration-list, then start the compound-statement. 503/// 504/// function-definition: [C99 6.9.1] 505/// decl-specs declarator declaration-list[opt] compound-statement 506/// [C90] function-definition: [C99 6.7.1] - implicit int result 507/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 508/// [C++] function-definition: [C++ 8.4] 509/// decl-specifier-seq[opt] declarator ctor-initializer[opt] function-body 510/// [C++] function-definition: [C++ 8.4] 511/// decl-specifier-seq[opt] declarator function-try-block [TODO] 512/// 513Parser::DeclTy *Parser::ParseFunctionDefinition(Declarator &D) { 514 const DeclaratorChunk &FnTypeInfo = D.getTypeObject(0); 515 assert(FnTypeInfo.Kind == DeclaratorChunk::Function && 516 "This isn't a function declarator!"); 517 const DeclaratorChunk::FunctionTypeInfo &FTI = FnTypeInfo.Fun; 518 519 // If this is C90 and the declspecs were completely missing, fudge in an 520 // implicit int. We do this here because this is the only place where 521 // declaration-specifiers are completely optional in the grammar. 522 if (getLang().ImplicitInt && D.getDeclSpec().getParsedSpecifiers() == 0) { 523 const char *PrevSpec; 524 D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int, 525 D.getIdentifierLoc(), 526 PrevSpec); 527 } 528 529 // If this declaration was formed with a K&R-style identifier list for the 530 // arguments, parse declarations for all of the args next. 531 // int foo(a,b) int a; float b; {} 532 if (!FTI.hasPrototype && FTI.NumArgs != 0) 533 ParseKNRParamDeclarations(D); 534 535 // We should have either an opening brace or, in a C++ constructor, 536 // we may have a colon. 537 // FIXME: In C++, we might also find the 'try' keyword. 538 if (Tok.isNot(tok::l_brace) && Tok.isNot(tok::colon)) { 539 Diag(Tok, diag::err_expected_fn_body); 540 541 // Skip over garbage, until we get to '{'. Don't eat the '{'. 542 SkipUntil(tok::l_brace, true, true); 543 544 // If we didn't find the '{', bail out. 545 if (Tok.isNot(tok::l_brace)) 546 return 0; 547 } 548 549 // Enter a scope for the function body. 550 ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope); 551 552 // Tell the actions module that we have entered a function definition with the 553 // specified Declarator for the function. 554 DeclTy *Res = Actions.ActOnStartOfFunctionDef(CurScope, D); 555 556 // If we have a colon, then we're probably parsing a C++ 557 // ctor-initializer. 558 if (Tok.is(tok::colon)) 559 ParseConstructorInitializer(Res); 560 561 SourceLocation BraceLoc = Tok.getLocation(); 562 return ParseFunctionStatementBody(Res, BraceLoc, BraceLoc); 563} 564 565/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides 566/// types for a function with a K&R-style identifier list for arguments. 567void Parser::ParseKNRParamDeclarations(Declarator &D) { 568 // We know that the top-level of this declarator is a function. 569 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 570 571 // Enter function-declaration scope, limiting any declarators to the 572 // function prototype scope, including parameter declarators. 573 ParseScope PrototypeScope(this, Scope::FnScope|Scope::DeclScope); 574 575 // Read all the argument declarations. 576 while (isDeclarationSpecifier()) { 577 SourceLocation DSStart = Tok.getLocation(); 578 579 // Parse the common declaration-specifiers piece. 580 DeclSpec DS; 581 ParseDeclarationSpecifiers(DS); 582 583 // C99 6.9.1p6: 'each declaration in the declaration list shall have at 584 // least one declarator'. 585 // NOTE: GCC just makes this an ext-warn. It's not clear what it does with 586 // the declarations though. It's trivial to ignore them, really hard to do 587 // anything else with them. 588 if (Tok.is(tok::semi)) { 589 Diag(DSStart, diag::err_declaration_does_not_declare_param); 590 ConsumeToken(); 591 continue; 592 } 593 594 // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other 595 // than register. 596 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 597 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 598 Diag(DS.getStorageClassSpecLoc(), 599 diag::err_invalid_storage_class_in_func_decl); 600 DS.ClearStorageClassSpecs(); 601 } 602 if (DS.isThreadSpecified()) { 603 Diag(DS.getThreadSpecLoc(), 604 diag::err_invalid_storage_class_in_func_decl); 605 DS.ClearStorageClassSpecs(); 606 } 607 608 // Parse the first declarator attached to this declspec. 609 Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext); 610 ParseDeclarator(ParmDeclarator); 611 612 // Handle the full declarator list. 613 while (1) { 614 DeclTy *AttrList; 615 // If attributes are present, parse them. 616 if (Tok.is(tok::kw___attribute)) 617 // FIXME: attach attributes too. 618 AttrList = ParseAttributes(); 619 620 // Ask the actions module to compute the type for this declarator. 621 Action::DeclTy *Param = 622 Actions.ActOnParamDeclarator(CurScope, ParmDeclarator); 623 624 if (Param && 625 // A missing identifier has already been diagnosed. 626 ParmDeclarator.getIdentifier()) { 627 628 // Scan the argument list looking for the correct param to apply this 629 // type. 630 for (unsigned i = 0; ; ++i) { 631 // C99 6.9.1p6: those declarators shall declare only identifiers from 632 // the identifier list. 633 if (i == FTI.NumArgs) { 634 Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param) 635 << ParmDeclarator.getIdentifier(); 636 break; 637 } 638 639 if (FTI.ArgInfo[i].Ident == ParmDeclarator.getIdentifier()) { 640 // Reject redefinitions of parameters. 641 if (FTI.ArgInfo[i].Param) { 642 Diag(ParmDeclarator.getIdentifierLoc(), 643 diag::err_param_redefinition) 644 << ParmDeclarator.getIdentifier(); 645 } else { 646 FTI.ArgInfo[i].Param = Param; 647 } 648 break; 649 } 650 } 651 } 652 653 // If we don't have a comma, it is either the end of the list (a ';') or 654 // an error, bail out. 655 if (Tok.isNot(tok::comma)) 656 break; 657 658 // Consume the comma. 659 ConsumeToken(); 660 661 // Parse the next declarator. 662 ParmDeclarator.clear(); 663 ParseDeclarator(ParmDeclarator); 664 } 665 666 if (Tok.is(tok::semi)) { 667 ConsumeToken(); 668 } else { 669 Diag(Tok, diag::err_parse_error); 670 // Skip to end of block or statement 671 SkipUntil(tok::semi, true); 672 if (Tok.is(tok::semi)) 673 ConsumeToken(); 674 } 675 } 676 677 // The actions module must verify that all arguments were declared. 678} 679 680 681/// ParseAsmStringLiteral - This is just a normal string-literal, but is not 682/// allowed to be a wide string, and is not subject to character translation. 683/// 684/// [GNU] asm-string-literal: 685/// string-literal 686/// 687Parser::OwningExprResult Parser::ParseAsmStringLiteral() { 688 if (!isTokenStringLiteral()) { 689 Diag(Tok, diag::err_expected_string_literal); 690 return ExprError(); 691 } 692 693 OwningExprResult Res(ParseStringLiteralExpression()); 694 if (Res.isInvalid()) return move(Res); 695 696 // TODO: Diagnose: wide string literal in 'asm' 697 698 return move(Res); 699} 700 701/// ParseSimpleAsm 702/// 703/// [GNU] simple-asm-expr: 704/// 'asm' '(' asm-string-literal ')' 705/// 706Parser::OwningExprResult Parser::ParseSimpleAsm() { 707 assert(Tok.is(tok::kw_asm) && "Not an asm!"); 708 SourceLocation Loc = ConsumeToken(); 709 710 if (Tok.isNot(tok::l_paren)) { 711 Diag(Tok, diag::err_expected_lparen_after) << "asm"; 712 return ExprError(); 713 } 714 715 ConsumeParen(); 716 717 OwningExprResult Result(ParseAsmStringLiteral()); 718 719 if (Result.isInvalid()) 720 SkipUntil(tok::r_paren); 721 else 722 MatchRHSPunctuation(tok::r_paren, Loc); 723 724 return move(Result); 725} 726 727/// TryAnnotateTypeOrScopeToken - If the current token position is on a 728/// typename (possibly qualified in C++) or a C++ scope specifier not followed 729/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens 730/// with a single annotation token representing the typename or C++ scope 731/// respectively. 732/// This simplifies handling of C++ scope specifiers and allows efficient 733/// backtracking without the need to re-parse and resolve nested-names and 734/// typenames. 735/// It will mainly be called when we expect to treat identifiers as typenames 736/// (if they are typenames). For example, in C we do not expect identifiers 737/// inside expressions to be treated as typenames so it will not be called 738/// for expressions in C. 739/// The benefit for C/ObjC is that a typename will be annotated and 740/// Actions.isTypeName will not be needed to be called again (e.g. isTypeName 741/// will not be called twice, once to check whether we have a declaration 742/// specifier, and another one to get the actual type inside 743/// ParseDeclarationSpecifiers). 744/// 745/// This returns true if the token was annotated. 746bool Parser::TryAnnotateTypeOrScopeToken(const Token *GlobalQualifier) { 747 // FIXME: what about template-ids? 748 if (Tok.is(tok::annot_qualtypename) || Tok.is(tok::annot_cxxscope)) 749 return false; 750 751 CXXScopeSpec SS; 752 if (getLang().CPlusPlus) 753 MaybeParseCXXScopeSpecifier(SS, GlobalQualifier); 754 755 if (Tok.is(tok::identifier)) { 756 DeclTy *Template = 0; 757 // If this is a template-id, annotate the template-id token. 758 if (getLang().CPlusPlus && NextToken().is(tok::less) && 759 (Template = Actions.isTemplateName(*Tok.getIdentifierInfo(), CurScope, 760 &SS))) 761 AnnotateTemplateIdToken(Template, &SS); 762 else { 763 // Determine whether the identifier is a type name. 764 TypeTy *Ty = Actions.isTypeName(*Tok.getIdentifierInfo(), CurScope, &SS); 765 if (Ty) { 766 // This is a typename. Replace the current token in-place with an 767 // annotation type token. 768 Tok.setKind(tok::annot_qualtypename); 769 Tok.setAnnotationValue(Ty); 770 Tok.setAnnotationEndLoc(Tok.getLocation()); 771 if (SS.isNotEmpty()) // it was a C++ qualified type name. 772 Tok.setLocation(SS.getBeginLoc()); 773 774 // In case the tokens were cached, have Preprocessor replace 775 // them with the annotation token. 776 PP.AnnotateCachedTokens(Tok); 777 return true; 778 } 779 } 780 781 // We either have an identifier that is not a type name or we have 782 // just created a template-id that might be a type name. Both 783 // cases will be handled below. 784 } 785 786 // FIXME: check for a template-id token here, and look it up if it 787 // names a type. 788 789 if (SS.isEmpty()) 790 return false; 791 792 // A C++ scope specifier that isn't followed by a typename. 793 // Push the current token back into the token stream (or revert it if it is 794 // cached) and use an annotation scope token for current token. 795 if (PP.isBacktrackEnabled()) 796 PP.RevertCachedTokens(1); 797 else 798 PP.EnterToken(Tok); 799 Tok.setKind(tok::annot_cxxscope); 800 Tok.setAnnotationValue(SS.getScopeRep()); 801 Tok.setAnnotationRange(SS.getRange()); 802 803 // In case the tokens were cached, have Preprocessor replace them with the 804 // annotation token. 805 PP.AnnotateCachedTokens(Tok); 806 return true; 807} 808 809/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only 810/// annotates C++ scope specifiers. This returns true if the token was 811/// annotated. 812bool Parser::TryAnnotateCXXScopeToken() { 813 assert(getLang().CPlusPlus && 814 "Call sites of this function should be guarded by checking for C++"); 815 816 if (Tok.is(tok::annot_cxxscope)) 817 return false; 818 819 CXXScopeSpec SS; 820 if (!MaybeParseCXXScopeSpecifier(SS)) 821 return false; 822 823 // Push the current token back into the token stream (or revert it if it is 824 // cached) and use an annotation scope token for current token. 825 if (PP.isBacktrackEnabled()) 826 PP.RevertCachedTokens(1); 827 else 828 PP.EnterToken(Tok); 829 Tok.setKind(tok::annot_cxxscope); 830 Tok.setAnnotationValue(SS.getScopeRep()); 831 Tok.setAnnotationRange(SS.getRange()); 832 833 // In case the tokens were cached, have Preprocessor replace them with the 834 // annotation token. 835 PP.AnnotateCachedTokens(Tok); 836 return true; 837} 838