Parser.cpp revision 198893
164562Sgshapiro//===--- Parser.cpp - C Language Family Parser ----------------------------===// 264562Sgshapiro// 364562Sgshapiro// The LLVM Compiler Infrastructure 464562Sgshapiro// 564562Sgshapiro// This file is distributed under the University of Illinois Open Source 664562Sgshapiro// License. See LICENSE.TXT for details. 764562Sgshapiro// 864562Sgshapiro//===----------------------------------------------------------------------===// 964562Sgshapiro// 1064562Sgshapiro// This file implements the Parser interfaces. 1164562Sgshapiro// 1264562Sgshapiro//===----------------------------------------------------------------------===// 1364562Sgshapiro 1464562Sgshapiro#include "clang/Parse/Parser.h" 1564562Sgshapiro#include "clang/Parse/ParseDiagnostic.h" 1664562Sgshapiro#include "clang/Parse/DeclSpec.h" 1764562Sgshapiro#include "clang/Parse/Scope.h" 1864562Sgshapiro#include "llvm/Support/raw_ostream.h" 1964562Sgshapiro#include "ExtensionRAIIObject.h" 2064562Sgshapiro#include "ParsePragma.h" 2164562Sgshapirousing namespace clang; 2264562Sgshapiro 23/// \brief A comment handler that passes comments found by the preprocessor 24/// to the parser action. 25class ActionCommentHandler : public CommentHandler { 26 Action &Actions; 27 28public: 29 explicit ActionCommentHandler(Action &Actions) : Actions(Actions) { } 30 31 virtual void HandleComment(Preprocessor &PP, SourceRange Comment) { 32 Actions.ActOnComment(Comment); 33 } 34}; 35 36Parser::Parser(Preprocessor &pp, Action &actions) 37 : CrashInfo(*this), PP(pp), Actions(actions), Diags(PP.getDiagnostics()), 38 GreaterThanIsOperator(true), TemplateParameterDepth(0) { 39 Tok.setKind(tok::eof); 40 CurScope = 0; 41 NumCachedScopes = 0; 42 ParenCount = BracketCount = BraceCount = 0; 43 ObjCImpDecl = DeclPtrTy(); 44 45 // Add #pragma handlers. These are removed and destroyed in the 46 // destructor. 47 PackHandler.reset(new 48 PragmaPackHandler(&PP.getIdentifierTable().get("pack"), actions)); 49 PP.AddPragmaHandler(0, PackHandler.get()); 50 51 UnusedHandler.reset(new 52 PragmaUnusedHandler(&PP.getIdentifierTable().get("unused"), actions, 53 *this)); 54 PP.AddPragmaHandler(0, UnusedHandler.get()); 55 56 WeakHandler.reset(new 57 PragmaWeakHandler(&PP.getIdentifierTable().get("weak"), actions)); 58 PP.AddPragmaHandler(0, WeakHandler.get()); 59 60 CommentHandler.reset(new ActionCommentHandler(actions)); 61 PP.AddCommentHandler(CommentHandler.get()); 62} 63 64/// If a crash happens while the parser is active, print out a line indicating 65/// what the current token is. 66void PrettyStackTraceParserEntry::print(llvm::raw_ostream &OS) const { 67 const Token &Tok = P.getCurToken(); 68 if (Tok.is(tok::eof)) { 69 OS << "<eof> parser at end of file\n"; 70 return; 71 } 72 73 if (Tok.getLocation().isInvalid()) { 74 OS << "<unknown> parser at unknown location\n"; 75 return; 76 } 77 78 const Preprocessor &PP = P.getPreprocessor(); 79 Tok.getLocation().print(OS, PP.getSourceManager()); 80 if (Tok.isAnnotation()) 81 OS << ": at annotation token \n"; 82 else 83 OS << ": current parser token '" << PP.getSpelling(Tok) << "'\n"; 84} 85 86 87DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) { 88 return Diags.Report(FullSourceLoc(Loc, PP.getSourceManager()), DiagID); 89} 90 91DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) { 92 return Diag(Tok.getLocation(), DiagID); 93} 94 95/// \brief Emits a diagnostic suggesting parentheses surrounding a 96/// given range. 97/// 98/// \param Loc The location where we'll emit the diagnostic. 99/// \param Loc The kind of diagnostic to emit. 100/// \param ParenRange Source range enclosing code that should be parenthesized. 101void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK, 102 SourceRange ParenRange) { 103 SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd()); 104 if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 105 // We can't display the parentheses, so just dig the 106 // warning/error and return. 107 Diag(Loc, DK); 108 return; 109 } 110 111 Diag(Loc, DK) 112 << CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(") 113 << CodeModificationHint::CreateInsertion(EndLoc, ")"); 114} 115 116/// MatchRHSPunctuation - For punctuation with a LHS and RHS (e.g. '['/']'), 117/// this helper function matches and consumes the specified RHS token if 118/// present. If not present, it emits the specified diagnostic indicating 119/// that the parser failed to match the RHS of the token at LHSLoc. LHSName 120/// should be the name of the unmatched LHS token. 121SourceLocation Parser::MatchRHSPunctuation(tok::TokenKind RHSTok, 122 SourceLocation LHSLoc) { 123 124 if (Tok.is(RHSTok)) 125 return ConsumeAnyToken(); 126 127 SourceLocation R = Tok.getLocation(); 128 const char *LHSName = "unknown"; 129 diag::kind DID = diag::err_parse_error; 130 switch (RHSTok) { 131 default: break; 132 case tok::r_paren : LHSName = "("; DID = diag::err_expected_rparen; break; 133 case tok::r_brace : LHSName = "{"; DID = diag::err_expected_rbrace; break; 134 case tok::r_square: LHSName = "["; DID = diag::err_expected_rsquare; break; 135 case tok::greater: LHSName = "<"; DID = diag::err_expected_greater; break; 136 } 137 Diag(Tok, DID); 138 Diag(LHSLoc, diag::note_matching) << LHSName; 139 SkipUntil(RHSTok); 140 return R; 141} 142 143/// ExpectAndConsume - The parser expects that 'ExpectedTok' is next in the 144/// input. If so, it is consumed and false is returned. 145/// 146/// If the input is malformed, this emits the specified diagnostic. Next, if 147/// SkipToTok is specified, it calls SkipUntil(SkipToTok). Finally, true is 148/// returned. 149bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID, 150 const char *Msg, tok::TokenKind SkipToTok) { 151 if (Tok.is(ExpectedTok)) { 152 ConsumeAnyToken(); 153 return false; 154 } 155 156 const char *Spelling = 0; 157 SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation); 158 if (EndLoc.isValid() && 159 (Spelling = tok::getTokenSimpleSpelling(ExpectedTok))) { 160 // Show what code to insert to fix this problem. 161 Diag(EndLoc, DiagID) 162 << Msg 163 << CodeModificationHint::CreateInsertion(EndLoc, Spelling); 164 } else 165 Diag(Tok, DiagID) << Msg; 166 167 if (SkipToTok != tok::unknown) 168 SkipUntil(SkipToTok); 169 return true; 170} 171 172//===----------------------------------------------------------------------===// 173// Error recovery. 174//===----------------------------------------------------------------------===// 175 176/// SkipUntil - Read tokens until we get to the specified token, then consume 177/// it (unless DontConsume is true). Because we cannot guarantee that the 178/// token will ever occur, this skips to the next token, or to some likely 179/// good stopping point. If StopAtSemi is true, skipping will stop at a ';' 180/// character. 181/// 182/// If SkipUntil finds the specified token, it returns true, otherwise it 183/// returns false. 184bool Parser::SkipUntil(const tok::TokenKind *Toks, unsigned NumToks, 185 bool StopAtSemi, bool DontConsume) { 186 // We always want this function to skip at least one token if the first token 187 // isn't T and if not at EOF. 188 bool isFirstTokenSkipped = true; 189 while (1) { 190 // If we found one of the tokens, stop and return true. 191 for (unsigned i = 0; i != NumToks; ++i) { 192 if (Tok.is(Toks[i])) { 193 if (DontConsume) { 194 // Noop, don't consume the token. 195 } else { 196 ConsumeAnyToken(); 197 } 198 return true; 199 } 200 } 201 202 switch (Tok.getKind()) { 203 case tok::eof: 204 // Ran out of tokens. 205 return false; 206 207 case tok::l_paren: 208 // Recursively skip properly-nested parens. 209 ConsumeParen(); 210 SkipUntil(tok::r_paren, false); 211 break; 212 case tok::l_square: 213 // Recursively skip properly-nested square brackets. 214 ConsumeBracket(); 215 SkipUntil(tok::r_square, false); 216 break; 217 case tok::l_brace: 218 // Recursively skip properly-nested braces. 219 ConsumeBrace(); 220 SkipUntil(tok::r_brace, false); 221 break; 222 223 // Okay, we found a ']' or '}' or ')', which we think should be balanced. 224 // Since the user wasn't looking for this token (if they were, it would 225 // already be handled), this isn't balanced. If there is a LHS token at a 226 // higher level, we will assume that this matches the unbalanced token 227 // and return it. Otherwise, this is a spurious RHS token, which we skip. 228 case tok::r_paren: 229 if (ParenCount && !isFirstTokenSkipped) 230 return false; // Matches something. 231 ConsumeParen(); 232 break; 233 case tok::r_square: 234 if (BracketCount && !isFirstTokenSkipped) 235 return false; // Matches something. 236 ConsumeBracket(); 237 break; 238 case tok::r_brace: 239 if (BraceCount && !isFirstTokenSkipped) 240 return false; // Matches something. 241 ConsumeBrace(); 242 break; 243 244 case tok::string_literal: 245 case tok::wide_string_literal: 246 ConsumeStringToken(); 247 break; 248 case tok::semi: 249 if (StopAtSemi) 250 return false; 251 // FALL THROUGH. 252 default: 253 // Skip this token. 254 ConsumeToken(); 255 break; 256 } 257 isFirstTokenSkipped = false; 258 } 259} 260 261//===----------------------------------------------------------------------===// 262// Scope manipulation 263//===----------------------------------------------------------------------===// 264 265/// EnterScope - Start a new scope. 266void Parser::EnterScope(unsigned ScopeFlags) { 267 if (NumCachedScopes) { 268 Scope *N = ScopeCache[--NumCachedScopes]; 269 N->Init(CurScope, ScopeFlags); 270 CurScope = N; 271 } else { 272 CurScope = new Scope(CurScope, ScopeFlags); 273 } 274} 275 276/// ExitScope - Pop a scope off the scope stack. 277void Parser::ExitScope() { 278 assert(CurScope && "Scope imbalance!"); 279 280 // Inform the actions module that this scope is going away if there are any 281 // decls in it. 282 if (!CurScope->decl_empty()) 283 Actions.ActOnPopScope(Tok.getLocation(), CurScope); 284 285 Scope *OldScope = CurScope; 286 CurScope = OldScope->getParent(); 287 288 if (NumCachedScopes == ScopeCacheSize) 289 delete OldScope; 290 else 291 ScopeCache[NumCachedScopes++] = OldScope; 292} 293 294 295 296 297//===----------------------------------------------------------------------===// 298// C99 6.9: External Definitions. 299//===----------------------------------------------------------------------===// 300 301Parser::~Parser() { 302 // If we still have scopes active, delete the scope tree. 303 delete CurScope; 304 305 // Free the scope cache. 306 for (unsigned i = 0, e = NumCachedScopes; i != e; ++i) 307 delete ScopeCache[i]; 308 309 // Remove the pragma handlers we installed. 310 PP.RemovePragmaHandler(0, PackHandler.get()); 311 PackHandler.reset(); 312 PP.RemovePragmaHandler(0, UnusedHandler.get()); 313 UnusedHandler.reset(); 314 PP.RemovePragmaHandler(0, WeakHandler.get()); 315 WeakHandler.reset(); 316 PP.RemoveCommentHandler(CommentHandler.get()); 317} 318 319/// Initialize - Warm up the parser. 320/// 321void Parser::Initialize() { 322 // Prime the lexer look-ahead. 323 ConsumeToken(); 324 325 // Create the translation unit scope. Install it as the current scope. 326 assert(CurScope == 0 && "A scope is already active?"); 327 EnterScope(Scope::DeclScope); 328 Actions.ActOnTranslationUnitScope(Tok.getLocation(), CurScope); 329 330 if (Tok.is(tok::eof) && 331 !getLang().CPlusPlus) // Empty source file is an extension in C 332 Diag(Tok, diag::ext_empty_source_file); 333 334 // Initialization for Objective-C context sensitive keywords recognition. 335 // Referenced in Parser::ParseObjCTypeQualifierList. 336 if (getLang().ObjC1) { 337 ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in"); 338 ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out"); 339 ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout"); 340 ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway"); 341 ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy"); 342 ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref"); 343 } 344 345 Ident_super = &PP.getIdentifierTable().get("super"); 346} 347 348/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the 349/// action tells us to. This returns true if the EOF was encountered. 350bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) { 351 Result = DeclGroupPtrTy(); 352 if (Tok.is(tok::eof)) { 353 Actions.ActOnEndOfTranslationUnit(); 354 return true; 355 } 356 357 Result = ParseExternalDeclaration(); 358 return false; 359} 360 361/// ParseTranslationUnit: 362/// translation-unit: [C99 6.9] 363/// external-declaration 364/// translation-unit external-declaration 365void Parser::ParseTranslationUnit() { 366 Initialize(); 367 368 DeclGroupPtrTy Res; 369 while (!ParseTopLevelDecl(Res)) 370 /*parse them all*/; 371 372 ExitScope(); 373 assert(CurScope == 0 && "Scope imbalance!"); 374} 375 376/// ParseExternalDeclaration: 377/// 378/// external-declaration: [C99 6.9], declaration: [C++ dcl.dcl] 379/// function-definition 380/// declaration 381/// [C++0x] empty-declaration 382/// [GNU] asm-definition 383/// [GNU] __extension__ external-declaration 384/// [OBJC] objc-class-definition 385/// [OBJC] objc-class-declaration 386/// [OBJC] objc-alias-declaration 387/// [OBJC] objc-protocol-definition 388/// [OBJC] objc-method-definition 389/// [OBJC] @end 390/// [C++] linkage-specification 391/// [GNU] asm-definition: 392/// simple-asm-expr ';' 393/// 394/// [C++0x] empty-declaration: 395/// ';' 396/// 397/// [C++0x/GNU] 'extern' 'template' declaration 398Parser::DeclGroupPtrTy Parser::ParseExternalDeclaration() { 399 DeclPtrTy SingleDecl; 400 switch (Tok.getKind()) { 401 case tok::semi: 402 if (!getLang().CPlusPlus0x) 403 Diag(Tok, diag::ext_top_level_semi) 404 << CodeModificationHint::CreateRemoval(SourceRange(Tok.getLocation())); 405 406 ConsumeToken(); 407 // TODO: Invoke action for top-level semicolon. 408 return DeclGroupPtrTy(); 409 case tok::r_brace: 410 Diag(Tok, diag::err_expected_external_declaration); 411 ConsumeBrace(); 412 return DeclGroupPtrTy(); 413 case tok::eof: 414 Diag(Tok, diag::err_expected_external_declaration); 415 return DeclGroupPtrTy(); 416 case tok::kw___extension__: { 417 // __extension__ silences extension warnings in the subexpression. 418 ExtensionRAIIObject O(Diags); // Use RAII to do this. 419 ConsumeToken(); 420 return ParseExternalDeclaration(); 421 } 422 case tok::kw_asm: { 423 OwningExprResult Result(ParseSimpleAsm()); 424 425 ExpectAndConsume(tok::semi, diag::err_expected_semi_after, 426 "top-level asm block"); 427 428 if (Result.isInvalid()) 429 return DeclGroupPtrTy(); 430 SingleDecl = Actions.ActOnFileScopeAsmDecl(Tok.getLocation(), move(Result)); 431 break; 432 } 433 case tok::at: 434 // @ is not a legal token unless objc is enabled, no need to check for ObjC. 435 /// FIXME: ParseObjCAtDirectives should return a DeclGroup for things like 436 /// @class foo, bar; 437 SingleDecl = ParseObjCAtDirectives(); 438 break; 439 case tok::minus: 440 case tok::plus: 441 if (!getLang().ObjC1) { 442 Diag(Tok, diag::err_expected_external_declaration); 443 ConsumeToken(); 444 return DeclGroupPtrTy(); 445 } 446 SingleDecl = ParseObjCMethodDefinition(); 447 break; 448 case tok::code_completion: 449 Actions.CodeCompleteOrdinaryName(CurScope); 450 ConsumeToken(); 451 return ParseExternalDeclaration(); 452 case tok::kw_using: 453 case tok::kw_namespace: 454 case tok::kw_typedef: 455 case tok::kw_template: 456 case tok::kw_export: // As in 'export template' 457 case tok::kw_static_assert: 458 // A function definition cannot start with a these keywords. 459 { 460 SourceLocation DeclEnd; 461 return ParseDeclaration(Declarator::FileContext, DeclEnd); 462 } 463 case tok::kw_extern: 464 if (getLang().CPlusPlus && NextToken().is(tok::kw_template)) { 465 // Extern templates 466 SourceLocation ExternLoc = ConsumeToken(); 467 SourceLocation TemplateLoc = ConsumeToken(); 468 SourceLocation DeclEnd; 469 return Actions.ConvertDeclToDeclGroup( 470 ParseExplicitInstantiation(ExternLoc, TemplateLoc, DeclEnd)); 471 } 472 473 // FIXME: Detect C++ linkage specifications here? 474 475 // Fall through to handle other declarations or function definitions. 476 477 default: 478 // We can't tell whether this is a function-definition or declaration yet. 479 return ParseDeclarationOrFunctionDefinition(); 480 } 481 482 // This routine returns a DeclGroup, if the thing we parsed only contains a 483 // single decl, convert it now. 484 return Actions.ConvertDeclToDeclGroup(SingleDecl); 485} 486 487/// \brief Determine whether the current token, if it occurs after a 488/// declarator, continues a declaration or declaration list. 489bool Parser::isDeclarationAfterDeclarator() { 490 return Tok.is(tok::equal) || // int X()= -> not a function def 491 Tok.is(tok::comma) || // int X(), -> not a function def 492 Tok.is(tok::semi) || // int X(); -> not a function def 493 Tok.is(tok::kw_asm) || // int X() __asm__ -> not a function def 494 Tok.is(tok::kw___attribute) || // int X() __attr__ -> not a function def 495 (getLang().CPlusPlus && 496 Tok.is(tok::l_paren)); // int X(0) -> not a function def [C++] 497} 498 499/// \brief Determine whether the current token, if it occurs after a 500/// declarator, indicates the start of a function definition. 501bool Parser::isStartOfFunctionDefinition() { 502 return Tok.is(tok::l_brace) || // int X() {} 503 (!getLang().CPlusPlus && 504 isDeclarationSpecifier()) || // int X(f) int f; {} 505 (getLang().CPlusPlus && 506 (Tok.is(tok::colon) || // X() : Base() {} (used for ctors) 507 Tok.is(tok::kw_try))); // X() try { ... } 508} 509 510/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or 511/// a declaration. We can't tell which we have until we read up to the 512/// compound-statement in function-definition. TemplateParams, if 513/// non-NULL, provides the template parameters when we're parsing a 514/// C++ template-declaration. 515/// 516/// function-definition: [C99 6.9.1] 517/// decl-specs declarator declaration-list[opt] compound-statement 518/// [C90] function-definition: [C99 6.7.1] - implicit int result 519/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 520/// 521/// declaration: [C99 6.7] 522/// declaration-specifiers init-declarator-list[opt] ';' 523/// [!C99] init-declarator-list ';' [TODO: warn in c99 mode] 524/// [OMP] threadprivate-directive [TODO] 525/// 526Parser::DeclGroupPtrTy 527Parser::ParseDeclarationOrFunctionDefinition(AccessSpecifier AS) { 528 // Parse the common declaration-specifiers piece. 529 ParsingDeclSpec DS(*this); 530 ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS); 531 532 // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };" 533 // declaration-specifiers init-declarator-list[opt] ';' 534 if (Tok.is(tok::semi)) { 535 ConsumeToken(); 536 DeclPtrTy TheDecl = Actions.ParsedFreeStandingDeclSpec(CurScope, DS); 537 DS.complete(TheDecl); 538 return Actions.ConvertDeclToDeclGroup(TheDecl); 539 } 540 541 // ObjC2 allows prefix attributes on class interfaces and protocols. 542 // FIXME: This still needs better diagnostics. We should only accept 543 // attributes here, no types, etc. 544 if (getLang().ObjC2 && Tok.is(tok::at)) { 545 SourceLocation AtLoc = ConsumeToken(); // the "@" 546 if (!Tok.isObjCAtKeyword(tok::objc_interface) && 547 !Tok.isObjCAtKeyword(tok::objc_protocol)) { 548 Diag(Tok, diag::err_objc_unexpected_attr); 549 SkipUntil(tok::semi); // FIXME: better skip? 550 return DeclGroupPtrTy(); 551 } 552 553 DS.abort(); 554 555 const char *PrevSpec = 0; 556 unsigned DiagID; 557 if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID)) 558 Diag(AtLoc, DiagID) << PrevSpec; 559 560 DeclPtrTy TheDecl; 561 if (Tok.isObjCAtKeyword(tok::objc_protocol)) 562 TheDecl = ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes()); 563 else 564 TheDecl = ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()); 565 return Actions.ConvertDeclToDeclGroup(TheDecl); 566 } 567 568 // If the declspec consisted only of 'extern' and we have a string 569 // literal following it, this must be a C++ linkage specifier like 570 // 'extern "C"'. 571 if (Tok.is(tok::string_literal) && getLang().CPlusPlus && 572 DS.getStorageClassSpec() == DeclSpec::SCS_extern && 573 DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) { 574 DS.abort(); 575 DeclPtrTy TheDecl = ParseLinkage(Declarator::FileContext); 576 return Actions.ConvertDeclToDeclGroup(TheDecl); 577 } 578 579 return ParseDeclGroup(DS, Declarator::FileContext, true); 580} 581 582/// ParseFunctionDefinition - We parsed and verified that the specified 583/// Declarator is well formed. If this is a K&R-style function, read the 584/// parameters declaration-list, then start the compound-statement. 585/// 586/// function-definition: [C99 6.9.1] 587/// decl-specs declarator declaration-list[opt] compound-statement 588/// [C90] function-definition: [C99 6.7.1] - implicit int result 589/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 590/// [C++] function-definition: [C++ 8.4] 591/// decl-specifier-seq[opt] declarator ctor-initializer[opt] 592/// function-body 593/// [C++] function-definition: [C++ 8.4] 594/// decl-specifier-seq[opt] declarator function-try-block 595/// 596Parser::DeclPtrTy Parser::ParseFunctionDefinition(ParsingDeclarator &D, 597 const ParsedTemplateInfo &TemplateInfo) { 598 const DeclaratorChunk &FnTypeInfo = D.getTypeObject(0); 599 assert(FnTypeInfo.Kind == DeclaratorChunk::Function && 600 "This isn't a function declarator!"); 601 const DeclaratorChunk::FunctionTypeInfo &FTI = FnTypeInfo.Fun; 602 603 // If this is C90 and the declspecs were completely missing, fudge in an 604 // implicit int. We do this here because this is the only place where 605 // declaration-specifiers are completely optional in the grammar. 606 if (getLang().ImplicitInt && D.getDeclSpec().isEmpty()) { 607 const char *PrevSpec; 608 unsigned DiagID; 609 D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int, 610 D.getIdentifierLoc(), 611 PrevSpec, DiagID); 612 D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin()); 613 } 614 615 // If this declaration was formed with a K&R-style identifier list for the 616 // arguments, parse declarations for all of the args next. 617 // int foo(a,b) int a; float b; {} 618 if (!FTI.hasPrototype && FTI.NumArgs != 0) 619 ParseKNRParamDeclarations(D); 620 621 // We should have either an opening brace or, in a C++ constructor, 622 // we may have a colon. 623 if (Tok.isNot(tok::l_brace) && Tok.isNot(tok::colon) && 624 Tok.isNot(tok::kw_try)) { 625 Diag(Tok, diag::err_expected_fn_body); 626 627 // Skip over garbage, until we get to '{'. Don't eat the '{'. 628 SkipUntil(tok::l_brace, true, true); 629 630 // If we didn't find the '{', bail out. 631 if (Tok.isNot(tok::l_brace)) 632 return DeclPtrTy(); 633 } 634 635 // Enter a scope for the function body. 636 ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope); 637 638 // Tell the actions module that we have entered a function definition with the 639 // specified Declarator for the function. 640 DeclPtrTy Res = TemplateInfo.TemplateParams? 641 Actions.ActOnStartOfFunctionTemplateDef(CurScope, 642 Action::MultiTemplateParamsArg(Actions, 643 TemplateInfo.TemplateParams->data(), 644 TemplateInfo.TemplateParams->size()), 645 D) 646 : Actions.ActOnStartOfFunctionDef(CurScope, D); 647 648 // Break out of the ParsingDeclarator context before we parse the body. 649 D.complete(Res); 650 651 // Break out of the ParsingDeclSpec context, too. This const_cast is 652 // safe because we're always the sole owner. 653 D.getMutableDeclSpec().abort(); 654 655 if (Tok.is(tok::kw_try)) 656 return ParseFunctionTryBlock(Res); 657 658 // If we have a colon, then we're probably parsing a C++ 659 // ctor-initializer. 660 if (Tok.is(tok::colon)) 661 ParseConstructorInitializer(Res); 662 else 663 Actions.ActOnDefaultCtorInitializers(Res); 664 665 return ParseFunctionStatementBody(Res); 666} 667 668/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides 669/// types for a function with a K&R-style identifier list for arguments. 670void Parser::ParseKNRParamDeclarations(Declarator &D) { 671 // We know that the top-level of this declarator is a function. 672 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 673 674 // Enter function-declaration scope, limiting any declarators to the 675 // function prototype scope, including parameter declarators. 676 ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope|Scope::DeclScope); 677 678 // Read all the argument declarations. 679 while (isDeclarationSpecifier()) { 680 SourceLocation DSStart = Tok.getLocation(); 681 682 // Parse the common declaration-specifiers piece. 683 DeclSpec DS; 684 ParseDeclarationSpecifiers(DS); 685 686 // C99 6.9.1p6: 'each declaration in the declaration list shall have at 687 // least one declarator'. 688 // NOTE: GCC just makes this an ext-warn. It's not clear what it does with 689 // the declarations though. It's trivial to ignore them, really hard to do 690 // anything else with them. 691 if (Tok.is(tok::semi)) { 692 Diag(DSStart, diag::err_declaration_does_not_declare_param); 693 ConsumeToken(); 694 continue; 695 } 696 697 // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other 698 // than register. 699 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 700 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 701 Diag(DS.getStorageClassSpecLoc(), 702 diag::err_invalid_storage_class_in_func_decl); 703 DS.ClearStorageClassSpecs(); 704 } 705 if (DS.isThreadSpecified()) { 706 Diag(DS.getThreadSpecLoc(), 707 diag::err_invalid_storage_class_in_func_decl); 708 DS.ClearStorageClassSpecs(); 709 } 710 711 // Parse the first declarator attached to this declspec. 712 Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext); 713 ParseDeclarator(ParmDeclarator); 714 715 // Handle the full declarator list. 716 while (1) { 717 Action::AttrTy *AttrList; 718 // If attributes are present, parse them. 719 if (Tok.is(tok::kw___attribute)) 720 // FIXME: attach attributes too. 721 AttrList = ParseAttributes(); 722 723 // Ask the actions module to compute the type for this declarator. 724 Action::DeclPtrTy Param = 725 Actions.ActOnParamDeclarator(CurScope, ParmDeclarator); 726 727 if (Param && 728 // A missing identifier has already been diagnosed. 729 ParmDeclarator.getIdentifier()) { 730 731 // Scan the argument list looking for the correct param to apply this 732 // type. 733 for (unsigned i = 0; ; ++i) { 734 // C99 6.9.1p6: those declarators shall declare only identifiers from 735 // the identifier list. 736 if (i == FTI.NumArgs) { 737 Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param) 738 << ParmDeclarator.getIdentifier(); 739 break; 740 } 741 742 if (FTI.ArgInfo[i].Ident == ParmDeclarator.getIdentifier()) { 743 // Reject redefinitions of parameters. 744 if (FTI.ArgInfo[i].Param) { 745 Diag(ParmDeclarator.getIdentifierLoc(), 746 diag::err_param_redefinition) 747 << ParmDeclarator.getIdentifier(); 748 } else { 749 FTI.ArgInfo[i].Param = Param; 750 } 751 break; 752 } 753 } 754 } 755 756 // If we don't have a comma, it is either the end of the list (a ';') or 757 // an error, bail out. 758 if (Tok.isNot(tok::comma)) 759 break; 760 761 // Consume the comma. 762 ConsumeToken(); 763 764 // Parse the next declarator. 765 ParmDeclarator.clear(); 766 ParseDeclarator(ParmDeclarator); 767 } 768 769 if (Tok.is(tok::semi)) { 770 ConsumeToken(); 771 } else { 772 Diag(Tok, diag::err_parse_error); 773 // Skip to end of block or statement 774 SkipUntil(tok::semi, true); 775 if (Tok.is(tok::semi)) 776 ConsumeToken(); 777 } 778 } 779 780 // The actions module must verify that all arguments were declared. 781 Actions.ActOnFinishKNRParamDeclarations(CurScope, D, Tok.getLocation()); 782} 783 784 785/// ParseAsmStringLiteral - This is just a normal string-literal, but is not 786/// allowed to be a wide string, and is not subject to character translation. 787/// 788/// [GNU] asm-string-literal: 789/// string-literal 790/// 791Parser::OwningExprResult Parser::ParseAsmStringLiteral() { 792 if (!isTokenStringLiteral()) { 793 Diag(Tok, diag::err_expected_string_literal); 794 return ExprError(); 795 } 796 797 OwningExprResult Res(ParseStringLiteralExpression()); 798 if (Res.isInvalid()) return move(Res); 799 800 // TODO: Diagnose: wide string literal in 'asm' 801 802 return move(Res); 803} 804 805/// ParseSimpleAsm 806/// 807/// [GNU] simple-asm-expr: 808/// 'asm' '(' asm-string-literal ')' 809/// 810Parser::OwningExprResult Parser::ParseSimpleAsm(SourceLocation *EndLoc) { 811 assert(Tok.is(tok::kw_asm) && "Not an asm!"); 812 SourceLocation Loc = ConsumeToken(); 813 814 if (Tok.isNot(tok::l_paren)) { 815 Diag(Tok, diag::err_expected_lparen_after) << "asm"; 816 return ExprError(); 817 } 818 819 Loc = ConsumeParen(); 820 821 OwningExprResult Result(ParseAsmStringLiteral()); 822 823 if (Result.isInvalid()) { 824 SkipUntil(tok::r_paren, true, true); 825 if (EndLoc) 826 *EndLoc = Tok.getLocation(); 827 ConsumeAnyToken(); 828 } else { 829 Loc = MatchRHSPunctuation(tok::r_paren, Loc); 830 if (EndLoc) 831 *EndLoc = Loc; 832 } 833 834 return move(Result); 835} 836 837/// TryAnnotateTypeOrScopeToken - If the current token position is on a 838/// typename (possibly qualified in C++) or a C++ scope specifier not followed 839/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens 840/// with a single annotation token representing the typename or C++ scope 841/// respectively. 842/// This simplifies handling of C++ scope specifiers and allows efficient 843/// backtracking without the need to re-parse and resolve nested-names and 844/// typenames. 845/// It will mainly be called when we expect to treat identifiers as typenames 846/// (if they are typenames). For example, in C we do not expect identifiers 847/// inside expressions to be treated as typenames so it will not be called 848/// for expressions in C. 849/// The benefit for C/ObjC is that a typename will be annotated and 850/// Actions.getTypeName will not be needed to be called again (e.g. getTypeName 851/// will not be called twice, once to check whether we have a declaration 852/// specifier, and another one to get the actual type inside 853/// ParseDeclarationSpecifiers). 854/// 855/// This returns true if the token was annotated or an unrecoverable error 856/// occurs. 857/// 858/// Note that this routine emits an error if you call it with ::new or ::delete 859/// as the current tokens, so only call it in contexts where these are invalid. 860bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext) { 861 assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) 862 || Tok.is(tok::kw_typename)) && 863 "Cannot be a type or scope token!"); 864 865 if (Tok.is(tok::kw_typename)) { 866 // Parse a C++ typename-specifier, e.g., "typename T::type". 867 // 868 // typename-specifier: 869 // 'typename' '::' [opt] nested-name-specifier identifier 870 // 'typename' '::' [opt] nested-name-specifier template [opt] 871 // simple-template-id 872 SourceLocation TypenameLoc = ConsumeToken(); 873 CXXScopeSpec SS; 874 bool HadNestedNameSpecifier 875 = ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false); 876 if (!HadNestedNameSpecifier) { 877 Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename); 878 return false; 879 } 880 881 TypeResult Ty; 882 if (Tok.is(tok::identifier)) { 883 // FIXME: check whether the next token is '<', first! 884 Ty = Actions.ActOnTypenameType(TypenameLoc, SS, *Tok.getIdentifierInfo(), 885 Tok.getLocation()); 886 } else if (Tok.is(tok::annot_template_id)) { 887 TemplateIdAnnotation *TemplateId 888 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 889 if (TemplateId->Kind == TNK_Function_template) { 890 Diag(Tok, diag::err_typename_refers_to_non_type_template) 891 << Tok.getAnnotationRange(); 892 return false; 893 } 894 895 AnnotateTemplateIdTokenAsType(0); 896 assert(Tok.is(tok::annot_typename) && 897 "AnnotateTemplateIdTokenAsType isn't working properly"); 898 if (Tok.getAnnotationValue()) 899 Ty = Actions.ActOnTypenameType(TypenameLoc, SS, SourceLocation(), 900 Tok.getAnnotationValue()); 901 else 902 Ty = true; 903 } else { 904 Diag(Tok, diag::err_expected_type_name_after_typename) 905 << SS.getRange(); 906 return false; 907 } 908 909 Tok.setKind(tok::annot_typename); 910 Tok.setAnnotationValue(Ty.isInvalid()? 0 : Ty.get()); 911 Tok.setAnnotationEndLoc(Tok.getLocation()); 912 Tok.setLocation(TypenameLoc); 913 PP.AnnotateCachedTokens(Tok); 914 return true; 915 } 916 917 CXXScopeSpec SS; 918 if (getLang().CPlusPlus) 919 ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext); 920 921 if (Tok.is(tok::identifier)) { 922 // Determine whether the identifier is a type name. 923 if (TypeTy *Ty = Actions.getTypeName(*Tok.getIdentifierInfo(), 924 Tok.getLocation(), CurScope, &SS)) { 925 // This is a typename. Replace the current token in-place with an 926 // annotation type token. 927 Tok.setKind(tok::annot_typename); 928 Tok.setAnnotationValue(Ty); 929 Tok.setAnnotationEndLoc(Tok.getLocation()); 930 if (SS.isNotEmpty()) // it was a C++ qualified type name. 931 Tok.setLocation(SS.getBeginLoc()); 932 933 // In case the tokens were cached, have Preprocessor replace 934 // them with the annotation token. 935 PP.AnnotateCachedTokens(Tok); 936 return true; 937 } 938 939 if (!getLang().CPlusPlus) { 940 // If we're in C, we can't have :: tokens at all (the lexer won't return 941 // them). If the identifier is not a type, then it can't be scope either, 942 // just early exit. 943 return false; 944 } 945 946 // If this is a template-id, annotate with a template-id or type token. 947 if (NextToken().is(tok::less)) { 948 TemplateTy Template; 949 UnqualifiedId TemplateName; 950 TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); 951 if (TemplateNameKind TNK 952 = Actions.isTemplateName(CurScope, SS, TemplateName, 953 /*ObjectType=*/0, EnteringContext, 954 Template)) { 955 // Consume the identifier. 956 ConsumeToken(); 957 if (AnnotateTemplateIdToken(Template, TNK, &SS, TemplateName)) { 958 // If an unrecoverable error occurred, we need to return true here, 959 // because the token stream is in a damaged state. We may not return 960 // a valid identifier. 961 return Tok.isNot(tok::identifier); 962 } 963 } 964 } 965 966 // The current token, which is either an identifier or a 967 // template-id, is not part of the annotation. Fall through to 968 // push that token back into the stream and complete the C++ scope 969 // specifier annotation. 970 } 971 972 if (Tok.is(tok::annot_template_id)) { 973 TemplateIdAnnotation *TemplateId 974 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 975 if (TemplateId->Kind == TNK_Type_template) { 976 // A template-id that refers to a type was parsed into a 977 // template-id annotation in a context where we weren't allowed 978 // to produce a type annotation token. Update the template-id 979 // annotation token to a type annotation token now. 980 AnnotateTemplateIdTokenAsType(&SS); 981 return true; 982 } 983 } 984 985 if (SS.isEmpty()) 986 return Tok.isNot(tok::identifier) && Tok.isNot(tok::coloncolon); 987 988 // A C++ scope specifier that isn't followed by a typename. 989 // Push the current token back into the token stream (or revert it if it is 990 // cached) and use an annotation scope token for current token. 991 if (PP.isBacktrackEnabled()) 992 PP.RevertCachedTokens(1); 993 else 994 PP.EnterToken(Tok); 995 Tok.setKind(tok::annot_cxxscope); 996 Tok.setAnnotationValue(SS.getScopeRep()); 997 Tok.setAnnotationRange(SS.getRange()); 998 999 // In case the tokens were cached, have Preprocessor replace them with the 1000 // annotation token. 1001 PP.AnnotateCachedTokens(Tok); 1002 return true; 1003} 1004 1005/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only 1006/// annotates C++ scope specifiers and template-ids. This returns 1007/// true if the token was annotated or there was an error that could not be 1008/// recovered from. 1009/// 1010/// Note that this routine emits an error if you call it with ::new or ::delete 1011/// as the current tokens, so only call it in contexts where these are invalid. 1012bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) { 1013 assert(getLang().CPlusPlus && 1014 "Call sites of this function should be guarded by checking for C++"); 1015 assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon)) && 1016 "Cannot be a type or scope token!"); 1017 1018 CXXScopeSpec SS; 1019 if (!ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext)) 1020 return Tok.is(tok::annot_template_id); 1021 1022 // Push the current token back into the token stream (or revert it if it is 1023 // cached) and use an annotation scope token for current token. 1024 if (PP.isBacktrackEnabled()) 1025 PP.RevertCachedTokens(1); 1026 else 1027 PP.EnterToken(Tok); 1028 Tok.setKind(tok::annot_cxxscope); 1029 Tok.setAnnotationValue(SS.getScopeRep()); 1030 Tok.setAnnotationRange(SS.getRange()); 1031 1032 // In case the tokens were cached, have Preprocessor replace them with the 1033 // annotation token. 1034 PP.AnnotateCachedTokens(Tok); 1035 return true; 1036} 1037 1038// Anchor the Parser::FieldCallback vtable to this translation unit. 1039// We use a spurious method instead of the destructor because 1040// destroying FieldCallbacks can actually be slightly 1041// performance-sensitive. 1042void Parser::FieldCallback::_anchor() { 1043} 1044