Parser.cpp revision 202379
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/Parse/ParseDiagnostic.h" 16#include "clang/Parse/DeclSpec.h" 17#include "clang/Parse/Scope.h" 18#include "clang/Parse/Template.h" 19#include "llvm/Support/raw_ostream.h" 20#include "RAIIObjectsForParser.h" 21#include "ParsePragma.h" 22using namespace clang; 23 24/// \brief A comment handler that passes comments found by the preprocessor 25/// to the parser action. 26class ActionCommentHandler : public CommentHandler { 27 Action &Actions; 28 29public: 30 explicit ActionCommentHandler(Action &Actions) : Actions(Actions) { } 31 32 virtual void HandleComment(Preprocessor &PP, SourceRange Comment) { 33 Actions.ActOnComment(Comment); 34 } 35}; 36 37Parser::Parser(Preprocessor &pp, Action &actions) 38 : CrashInfo(*this), PP(pp), Actions(actions), Diags(PP.getDiagnostics()), 39 GreaterThanIsOperator(true), ColonIsSacred(false), 40 TemplateParameterDepth(0) { 41 Tok.setKind(tok::eof); 42 CurScope = 0; 43 NumCachedScopes = 0; 44 ParenCount = BracketCount = BraceCount = 0; 45 ObjCImpDecl = DeclPtrTy(); 46 47 // Add #pragma handlers. These are removed and destroyed in the 48 // destructor. 49 PackHandler.reset(new 50 PragmaPackHandler(&PP.getIdentifierTable().get("pack"), actions)); 51 PP.AddPragmaHandler(0, PackHandler.get()); 52 53 UnusedHandler.reset(new 54 PragmaUnusedHandler(&PP.getIdentifierTable().get("unused"), actions, 55 *this)); 56 PP.AddPragmaHandler(0, UnusedHandler.get()); 57 58 WeakHandler.reset(new 59 PragmaWeakHandler(&PP.getIdentifierTable().get("weak"), actions)); 60 PP.AddPragmaHandler(0, WeakHandler.get()); 61 62 CommentHandler.reset(new ActionCommentHandler(actions)); 63 PP.AddCommentHandler(CommentHandler.get()); 64} 65 66/// If a crash happens while the parser is active, print out a line indicating 67/// what the current token is. 68void PrettyStackTraceParserEntry::print(llvm::raw_ostream &OS) const { 69 const Token &Tok = P.getCurToken(); 70 if (Tok.is(tok::eof)) { 71 OS << "<eof> parser at end of file\n"; 72 return; 73 } 74 75 if (Tok.getLocation().isInvalid()) { 76 OS << "<unknown> parser at unknown location\n"; 77 return; 78 } 79 80 const Preprocessor &PP = P.getPreprocessor(); 81 Tok.getLocation().print(OS, PP.getSourceManager()); 82 if (Tok.isAnnotation()) 83 OS << ": at annotation token \n"; 84 else 85 OS << ": current parser token '" << PP.getSpelling(Tok) << "'\n"; 86} 87 88 89DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) { 90 return Diags.Report(FullSourceLoc(Loc, PP.getSourceManager()), DiagID); 91} 92 93DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) { 94 return Diag(Tok.getLocation(), DiagID); 95} 96 97/// \brief Emits a diagnostic suggesting parentheses surrounding a 98/// given range. 99/// 100/// \param Loc The location where we'll emit the diagnostic. 101/// \param Loc The kind of diagnostic to emit. 102/// \param ParenRange Source range enclosing code that should be parenthesized. 103void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK, 104 SourceRange ParenRange) { 105 SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd()); 106 if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 107 // We can't display the parentheses, so just dig the 108 // warning/error and return. 109 Diag(Loc, DK); 110 return; 111 } 112 113 Diag(Loc, DK) 114 << CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(") 115 << CodeModificationHint::CreateInsertion(EndLoc, ")"); 116} 117 118/// MatchRHSPunctuation - For punctuation with a LHS and RHS (e.g. '['/']'), 119/// this helper function matches and consumes the specified RHS token if 120/// present. If not present, it emits the specified diagnostic indicating 121/// that the parser failed to match the RHS of the token at LHSLoc. LHSName 122/// should be the name of the unmatched LHS token. 123SourceLocation Parser::MatchRHSPunctuation(tok::TokenKind RHSTok, 124 SourceLocation LHSLoc) { 125 126 if (Tok.is(RHSTok)) 127 return ConsumeAnyToken(); 128 129 SourceLocation R = Tok.getLocation(); 130 const char *LHSName = "unknown"; 131 diag::kind DID = diag::err_parse_error; 132 switch (RHSTok) { 133 default: break; 134 case tok::r_paren : LHSName = "("; DID = diag::err_expected_rparen; break; 135 case tok::r_brace : LHSName = "{"; DID = diag::err_expected_rbrace; break; 136 case tok::r_square: LHSName = "["; DID = diag::err_expected_rsquare; break; 137 case tok::greater: LHSName = "<"; DID = diag::err_expected_greater; break; 138 } 139 Diag(Tok, DID); 140 Diag(LHSLoc, diag::note_matching) << LHSName; 141 SkipUntil(RHSTok); 142 return R; 143} 144 145/// ExpectAndConsume - The parser expects that 'ExpectedTok' is next in the 146/// input. If so, it is consumed and false is returned. 147/// 148/// If the input is malformed, this emits the specified diagnostic. Next, if 149/// SkipToTok is specified, it calls SkipUntil(SkipToTok). Finally, true is 150/// returned. 151bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID, 152 const char *Msg, tok::TokenKind SkipToTok) { 153 if (Tok.is(ExpectedTok)) { 154 ConsumeAnyToken(); 155 return false; 156 } 157 158 const char *Spelling = 0; 159 SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation); 160 if (EndLoc.isValid() && 161 (Spelling = tok::getTokenSimpleSpelling(ExpectedTok))) { 162 // Show what code to insert to fix this problem. 163 Diag(EndLoc, DiagID) 164 << Msg 165 << CodeModificationHint::CreateInsertion(EndLoc, Spelling); 166 } else 167 Diag(Tok, DiagID) << Msg; 168 169 if (SkipToTok != tok::unknown) 170 SkipUntil(SkipToTok); 171 return true; 172} 173 174//===----------------------------------------------------------------------===// 175// Error recovery. 176//===----------------------------------------------------------------------===// 177 178/// SkipUntil - Read tokens until we get to the specified token, then consume 179/// it (unless DontConsume is true). Because we cannot guarantee that the 180/// token will ever occur, this skips to the next token, or to some likely 181/// good stopping point. If StopAtSemi is true, skipping will stop at a ';' 182/// character. 183/// 184/// If SkipUntil finds the specified token, it returns true, otherwise it 185/// returns false. 186bool Parser::SkipUntil(const tok::TokenKind *Toks, unsigned NumToks, 187 bool StopAtSemi, bool DontConsume) { 188 // We always want this function to skip at least one token if the first token 189 // isn't T and if not at EOF. 190 bool isFirstTokenSkipped = true; 191 while (1) { 192 // If we found one of the tokens, stop and return true. 193 for (unsigned i = 0; i != NumToks; ++i) { 194 if (Tok.is(Toks[i])) { 195 if (DontConsume) { 196 // Noop, don't consume the token. 197 } else { 198 ConsumeAnyToken(); 199 } 200 return true; 201 } 202 } 203 204 switch (Tok.getKind()) { 205 case tok::eof: 206 // Ran out of tokens. 207 return false; 208 209 case tok::l_paren: 210 // Recursively skip properly-nested parens. 211 ConsumeParen(); 212 SkipUntil(tok::r_paren, false); 213 break; 214 case tok::l_square: 215 // Recursively skip properly-nested square brackets. 216 ConsumeBracket(); 217 SkipUntil(tok::r_square, false); 218 break; 219 case tok::l_brace: 220 // Recursively skip properly-nested braces. 221 ConsumeBrace(); 222 SkipUntil(tok::r_brace, false); 223 break; 224 225 // Okay, we found a ']' or '}' or ')', which we think should be balanced. 226 // Since the user wasn't looking for this token (if they were, it would 227 // already be handled), this isn't balanced. If there is a LHS token at a 228 // higher level, we will assume that this matches the unbalanced token 229 // and return it. Otherwise, this is a spurious RHS token, which we skip. 230 case tok::r_paren: 231 if (ParenCount && !isFirstTokenSkipped) 232 return false; // Matches something. 233 ConsumeParen(); 234 break; 235 case tok::r_square: 236 if (BracketCount && !isFirstTokenSkipped) 237 return false; // Matches something. 238 ConsumeBracket(); 239 break; 240 case tok::r_brace: 241 if (BraceCount && !isFirstTokenSkipped) 242 return false; // Matches something. 243 ConsumeBrace(); 244 break; 245 246 case tok::string_literal: 247 case tok::wide_string_literal: 248 ConsumeStringToken(); 249 break; 250 case tok::semi: 251 if (StopAtSemi) 252 return false; 253 // FALL THROUGH. 254 default: 255 // Skip this token. 256 ConsumeToken(); 257 break; 258 } 259 isFirstTokenSkipped = false; 260 } 261} 262 263//===----------------------------------------------------------------------===// 264// Scope manipulation 265//===----------------------------------------------------------------------===// 266 267/// EnterScope - Start a new scope. 268void Parser::EnterScope(unsigned ScopeFlags) { 269 if (NumCachedScopes) { 270 Scope *N = ScopeCache[--NumCachedScopes]; 271 N->Init(CurScope, ScopeFlags); 272 CurScope = N; 273 } else { 274 CurScope = new Scope(CurScope, ScopeFlags); 275 } 276} 277 278/// ExitScope - Pop a scope off the scope stack. 279void Parser::ExitScope() { 280 assert(CurScope && "Scope imbalance!"); 281 282 // Inform the actions module that this scope is going away if there are any 283 // decls in it. 284 if (!CurScope->decl_empty()) 285 Actions.ActOnPopScope(Tok.getLocation(), CurScope); 286 287 Scope *OldScope = CurScope; 288 CurScope = OldScope->getParent(); 289 290 if (NumCachedScopes == ScopeCacheSize) 291 delete OldScope; 292 else 293 ScopeCache[NumCachedScopes++] = OldScope; 294} 295 296 297 298 299//===----------------------------------------------------------------------===// 300// C99 6.9: External Definitions. 301//===----------------------------------------------------------------------===// 302 303Parser::~Parser() { 304 // If we still have scopes active, delete the scope tree. 305 delete CurScope; 306 307 // Free the scope cache. 308 for (unsigned i = 0, e = NumCachedScopes; i != e; ++i) 309 delete ScopeCache[i]; 310 311 // Remove the pragma handlers we installed. 312 PP.RemovePragmaHandler(0, PackHandler.get()); 313 PackHandler.reset(); 314 PP.RemovePragmaHandler(0, UnusedHandler.get()); 315 UnusedHandler.reset(); 316 PP.RemovePragmaHandler(0, WeakHandler.get()); 317 WeakHandler.reset(); 318 PP.RemoveCommentHandler(CommentHandler.get()); 319} 320 321/// Initialize - Warm up the parser. 322/// 323void Parser::Initialize() { 324 // Prime the lexer look-ahead. 325 ConsumeToken(); 326 327 // Create the translation unit scope. Install it as the current scope. 328 assert(CurScope == 0 && "A scope is already active?"); 329 EnterScope(Scope::DeclScope); 330 Actions.ActOnTranslationUnitScope(Tok.getLocation(), CurScope); 331 332 if (Tok.is(tok::eof) && 333 !getLang().CPlusPlus) // Empty source file is an extension in C 334 Diag(Tok, diag::ext_empty_source_file); 335 336 // Initialization for Objective-C context sensitive keywords recognition. 337 // Referenced in Parser::ParseObjCTypeQualifierList. 338 if (getLang().ObjC1) { 339 ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in"); 340 ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out"); 341 ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout"); 342 ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway"); 343 ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy"); 344 ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref"); 345 } 346 347 Ident_super = &PP.getIdentifierTable().get("super"); 348} 349 350/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the 351/// action tells us to. This returns true if the EOF was encountered. 352bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) { 353 Result = DeclGroupPtrTy(); 354 if (Tok.is(tok::eof)) { 355 Actions.ActOnEndOfTranslationUnit(); 356 return true; 357 } 358 359 CXX0XAttributeList Attr; 360 if (getLang().CPlusPlus0x && isCXX0XAttributeSpecifier()) 361 Attr = ParseCXX0XAttributes(); 362 Result = ParseExternalDeclaration(Attr); 363 return false; 364} 365 366/// ParseTranslationUnit: 367/// translation-unit: [C99 6.9] 368/// external-declaration 369/// translation-unit external-declaration 370void Parser::ParseTranslationUnit() { 371 Initialize(); 372 373 DeclGroupPtrTy Res; 374 while (!ParseTopLevelDecl(Res)) 375 /*parse them all*/; 376 377 ExitScope(); 378 assert(CurScope == 0 && "Scope imbalance!"); 379} 380 381/// ParseExternalDeclaration: 382/// 383/// external-declaration: [C99 6.9], declaration: [C++ dcl.dcl] 384/// function-definition 385/// declaration 386/// [C++0x] empty-declaration 387/// [GNU] asm-definition 388/// [GNU] __extension__ external-declaration 389/// [OBJC] objc-class-definition 390/// [OBJC] objc-class-declaration 391/// [OBJC] objc-alias-declaration 392/// [OBJC] objc-protocol-definition 393/// [OBJC] objc-method-definition 394/// [OBJC] @end 395/// [C++] linkage-specification 396/// [GNU] asm-definition: 397/// simple-asm-expr ';' 398/// 399/// [C++0x] empty-declaration: 400/// ';' 401/// 402/// [C++0x/GNU] 'extern' 'template' declaration 403Parser::DeclGroupPtrTy Parser::ParseExternalDeclaration(CXX0XAttributeList Attr) { 404 DeclPtrTy SingleDecl; 405 switch (Tok.getKind()) { 406 case tok::semi: 407 if (!getLang().CPlusPlus0x) 408 Diag(Tok, diag::ext_top_level_semi) 409 << CodeModificationHint::CreateRemoval(Tok.getLocation()); 410 411 ConsumeToken(); 412 // TODO: Invoke action for top-level semicolon. 413 return DeclGroupPtrTy(); 414 case tok::r_brace: 415 Diag(Tok, diag::err_expected_external_declaration); 416 ConsumeBrace(); 417 return DeclGroupPtrTy(); 418 case tok::eof: 419 Diag(Tok, diag::err_expected_external_declaration); 420 return DeclGroupPtrTy(); 421 case tok::kw___extension__: { 422 // __extension__ silences extension warnings in the subexpression. 423 ExtensionRAIIObject O(Diags); // Use RAII to do this. 424 ConsumeToken(); 425 return ParseExternalDeclaration(Attr); 426 } 427 case tok::kw_asm: { 428 if (Attr.HasAttr) 429 Diag(Attr.Range.getBegin(), diag::err_attributes_not_allowed) 430 << Attr.Range; 431 432 OwningExprResult Result(ParseSimpleAsm()); 433 434 ExpectAndConsume(tok::semi, diag::err_expected_semi_after, 435 "top-level asm block"); 436 437 if (Result.isInvalid()) 438 return DeclGroupPtrTy(); 439 SingleDecl = Actions.ActOnFileScopeAsmDecl(Tok.getLocation(), move(Result)); 440 break; 441 } 442 case tok::at: 443 // @ is not a legal token unless objc is enabled, no need to check for ObjC. 444 /// FIXME: ParseObjCAtDirectives should return a DeclGroup for things like 445 /// @class foo, bar; 446 SingleDecl = ParseObjCAtDirectives(); 447 break; 448 case tok::minus: 449 case tok::plus: 450 if (!getLang().ObjC1) { 451 Diag(Tok, diag::err_expected_external_declaration); 452 ConsumeToken(); 453 return DeclGroupPtrTy(); 454 } 455 SingleDecl = ParseObjCMethodDefinition(); 456 break; 457 case tok::code_completion: 458 Actions.CodeCompleteOrdinaryName(CurScope, 459 ObjCImpDecl? Action::CCC_ObjCImplementation 460 : Action::CCC_Namespace); 461 ConsumeToken(); 462 return ParseExternalDeclaration(Attr); 463 case tok::kw_using: 464 case tok::kw_namespace: 465 case tok::kw_typedef: 466 case tok::kw_template: 467 case tok::kw_export: // As in 'export template' 468 case tok::kw_static_assert: 469 // A function definition cannot start with a these keywords. 470 { 471 SourceLocation DeclEnd; 472 return ParseDeclaration(Declarator::FileContext, DeclEnd, Attr); 473 } 474 case tok::kw_extern: 475 if (getLang().CPlusPlus && NextToken().is(tok::kw_template)) { 476 // Extern templates 477 SourceLocation ExternLoc = ConsumeToken(); 478 SourceLocation TemplateLoc = ConsumeToken(); 479 SourceLocation DeclEnd; 480 return Actions.ConvertDeclToDeclGroup( 481 ParseExplicitInstantiation(ExternLoc, TemplateLoc, DeclEnd)); 482 } 483 484 // FIXME: Detect C++ linkage specifications here? 485 486 // Fall through to handle other declarations or function definitions. 487 488 default: 489 // We can't tell whether this is a function-definition or declaration yet. 490 return ParseDeclarationOrFunctionDefinition(Attr.AttrList); 491 } 492 493 // This routine returns a DeclGroup, if the thing we parsed only contains a 494 // single decl, convert it now. 495 return Actions.ConvertDeclToDeclGroup(SingleDecl); 496} 497 498/// \brief Determine whether the current token, if it occurs after a 499/// declarator, continues a declaration or declaration list. 500bool Parser::isDeclarationAfterDeclarator() { 501 return Tok.is(tok::equal) || // int X()= -> not a function def 502 Tok.is(tok::comma) || // int X(), -> not a function def 503 Tok.is(tok::semi) || // int X(); -> not a function def 504 Tok.is(tok::kw_asm) || // int X() __asm__ -> not a function def 505 Tok.is(tok::kw___attribute) || // int X() __attr__ -> not a function def 506 (getLang().CPlusPlus && 507 Tok.is(tok::l_paren)); // int X(0) -> not a function def [C++] 508} 509 510/// \brief Determine whether the current token, if it occurs after a 511/// declarator, indicates the start of a function definition. 512bool Parser::isStartOfFunctionDefinition() { 513 if (Tok.is(tok::l_brace)) // int X() {} 514 return true; 515 516 if (!getLang().CPlusPlus) 517 return isDeclarationSpecifier(); // int X(f) int f; {} 518 return Tok.is(tok::colon) || // X() : Base() {} (used for ctors) 519 Tok.is(tok::kw_try); // X() try { ... } 520} 521 522/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or 523/// a declaration. We can't tell which we have until we read up to the 524/// compound-statement in function-definition. TemplateParams, if 525/// non-NULL, provides the template parameters when we're parsing a 526/// C++ template-declaration. 527/// 528/// function-definition: [C99 6.9.1] 529/// decl-specs declarator declaration-list[opt] compound-statement 530/// [C90] function-definition: [C99 6.7.1] - implicit int result 531/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 532/// 533/// declaration: [C99 6.7] 534/// declaration-specifiers init-declarator-list[opt] ';' 535/// [!C99] init-declarator-list ';' [TODO: warn in c99 mode] 536/// [OMP] threadprivate-directive [TODO] 537/// 538Parser::DeclGroupPtrTy 539Parser::ParseDeclarationOrFunctionDefinition(ParsingDeclSpec &DS, 540 AttributeList *Attr, 541 AccessSpecifier AS) { 542 // Parse the common declaration-specifiers piece. 543 if (Attr) 544 DS.AddAttributes(Attr); 545 546 ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS, DSC_top_level); 547 548 // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };" 549 // declaration-specifiers init-declarator-list[opt] ';' 550 if (Tok.is(tok::semi)) { 551 ConsumeToken(); 552 DeclPtrTy TheDecl = Actions.ParsedFreeStandingDeclSpec(CurScope, DS); 553 DS.complete(TheDecl); 554 return Actions.ConvertDeclToDeclGroup(TheDecl); 555 } 556 557 // ObjC2 allows prefix attributes on class interfaces and protocols. 558 // FIXME: This still needs better diagnostics. We should only accept 559 // attributes here, no types, etc. 560 if (getLang().ObjC2 && Tok.is(tok::at)) { 561 SourceLocation AtLoc = ConsumeToken(); // the "@" 562 if (!Tok.isObjCAtKeyword(tok::objc_interface) && 563 !Tok.isObjCAtKeyword(tok::objc_protocol)) { 564 Diag(Tok, diag::err_objc_unexpected_attr); 565 SkipUntil(tok::semi); // FIXME: better skip? 566 return DeclGroupPtrTy(); 567 } 568 569 DS.abort(); 570 571 const char *PrevSpec = 0; 572 unsigned DiagID; 573 if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID)) 574 Diag(AtLoc, DiagID) << PrevSpec; 575 576 DeclPtrTy TheDecl; 577 if (Tok.isObjCAtKeyword(tok::objc_protocol)) 578 TheDecl = ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes()); 579 else 580 TheDecl = ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes()); 581 return Actions.ConvertDeclToDeclGroup(TheDecl); 582 } 583 584 // If the declspec consisted only of 'extern' and we have a string 585 // literal following it, this must be a C++ linkage specifier like 586 // 'extern "C"'. 587 if (Tok.is(tok::string_literal) && getLang().CPlusPlus && 588 DS.getStorageClassSpec() == DeclSpec::SCS_extern && 589 DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) { 590 DS.abort(); 591 DeclPtrTy TheDecl = ParseLinkage(DS, Declarator::FileContext); 592 return Actions.ConvertDeclToDeclGroup(TheDecl); 593 } 594 595 return ParseDeclGroup(DS, Declarator::FileContext, true); 596} 597 598Parser::DeclGroupPtrTy 599Parser::ParseDeclarationOrFunctionDefinition(AttributeList *Attr, 600 AccessSpecifier AS) { 601 ParsingDeclSpec DS(*this); 602 return ParseDeclarationOrFunctionDefinition(DS, Attr, AS); 603} 604 605/// ParseFunctionDefinition - We parsed and verified that the specified 606/// Declarator is well formed. If this is a K&R-style function, read the 607/// parameters declaration-list, then start the compound-statement. 608/// 609/// function-definition: [C99 6.9.1] 610/// decl-specs declarator declaration-list[opt] compound-statement 611/// [C90] function-definition: [C99 6.7.1] - implicit int result 612/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement 613/// [C++] function-definition: [C++ 8.4] 614/// decl-specifier-seq[opt] declarator ctor-initializer[opt] 615/// function-body 616/// [C++] function-definition: [C++ 8.4] 617/// decl-specifier-seq[opt] declarator function-try-block 618/// 619Parser::DeclPtrTy Parser::ParseFunctionDefinition(ParsingDeclarator &D, 620 const ParsedTemplateInfo &TemplateInfo) { 621 const DeclaratorChunk &FnTypeInfo = D.getTypeObject(0); 622 assert(FnTypeInfo.Kind == DeclaratorChunk::Function && 623 "This isn't a function declarator!"); 624 const DeclaratorChunk::FunctionTypeInfo &FTI = FnTypeInfo.Fun; 625 626 // If this is C90 and the declspecs were completely missing, fudge in an 627 // implicit int. We do this here because this is the only place where 628 // declaration-specifiers are completely optional in the grammar. 629 if (getLang().ImplicitInt && D.getDeclSpec().isEmpty()) { 630 const char *PrevSpec; 631 unsigned DiagID; 632 D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int, 633 D.getIdentifierLoc(), 634 PrevSpec, DiagID); 635 D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin()); 636 } 637 638 // If this declaration was formed with a K&R-style identifier list for the 639 // arguments, parse declarations for all of the args next. 640 // int foo(a,b) int a; float b; {} 641 if (!FTI.hasPrototype && FTI.NumArgs != 0) 642 ParseKNRParamDeclarations(D); 643 644 // We should have either an opening brace or, in a C++ constructor, 645 // we may have a colon. 646 if (Tok.isNot(tok::l_brace) && Tok.isNot(tok::colon) && 647 Tok.isNot(tok::kw_try)) { 648 Diag(Tok, diag::err_expected_fn_body); 649 650 // Skip over garbage, until we get to '{'. Don't eat the '{'. 651 SkipUntil(tok::l_brace, true, true); 652 653 // If we didn't find the '{', bail out. 654 if (Tok.isNot(tok::l_brace)) 655 return DeclPtrTy(); 656 } 657 658 // Enter a scope for the function body. 659 ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope); 660 661 // Tell the actions module that we have entered a function definition with the 662 // specified Declarator for the function. 663 DeclPtrTy Res = TemplateInfo.TemplateParams? 664 Actions.ActOnStartOfFunctionTemplateDef(CurScope, 665 Action::MultiTemplateParamsArg(Actions, 666 TemplateInfo.TemplateParams->data(), 667 TemplateInfo.TemplateParams->size()), 668 D) 669 : Actions.ActOnStartOfFunctionDef(CurScope, D); 670 671 // Break out of the ParsingDeclarator context before we parse the body. 672 D.complete(Res); 673 674 // Break out of the ParsingDeclSpec context, too. This const_cast is 675 // safe because we're always the sole owner. 676 D.getMutableDeclSpec().abort(); 677 678 if (Tok.is(tok::kw_try)) 679 return ParseFunctionTryBlock(Res); 680 681 // If we have a colon, then we're probably parsing a C++ 682 // ctor-initializer. 683 if (Tok.is(tok::colon)) 684 ParseConstructorInitializer(Res); 685 else 686 Actions.ActOnDefaultCtorInitializers(Res); 687 688 return ParseFunctionStatementBody(Res); 689} 690 691/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides 692/// types for a function with a K&R-style identifier list for arguments. 693void Parser::ParseKNRParamDeclarations(Declarator &D) { 694 // We know that the top-level of this declarator is a function. 695 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun; 696 697 // Enter function-declaration scope, limiting any declarators to the 698 // function prototype scope, including parameter declarators. 699 ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope|Scope::DeclScope); 700 701 // Read all the argument declarations. 702 while (isDeclarationSpecifier()) { 703 SourceLocation DSStart = Tok.getLocation(); 704 705 // Parse the common declaration-specifiers piece. 706 DeclSpec DS; 707 ParseDeclarationSpecifiers(DS); 708 709 // C99 6.9.1p6: 'each declaration in the declaration list shall have at 710 // least one declarator'. 711 // NOTE: GCC just makes this an ext-warn. It's not clear what it does with 712 // the declarations though. It's trivial to ignore them, really hard to do 713 // anything else with them. 714 if (Tok.is(tok::semi)) { 715 Diag(DSStart, diag::err_declaration_does_not_declare_param); 716 ConsumeToken(); 717 continue; 718 } 719 720 // C99 6.9.1p6: Declarations shall contain no storage-class specifiers other 721 // than register. 722 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && 723 DS.getStorageClassSpec() != DeclSpec::SCS_register) { 724 Diag(DS.getStorageClassSpecLoc(), 725 diag::err_invalid_storage_class_in_func_decl); 726 DS.ClearStorageClassSpecs(); 727 } 728 if (DS.isThreadSpecified()) { 729 Diag(DS.getThreadSpecLoc(), 730 diag::err_invalid_storage_class_in_func_decl); 731 DS.ClearStorageClassSpecs(); 732 } 733 734 // Parse the first declarator attached to this declspec. 735 Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext); 736 ParseDeclarator(ParmDeclarator); 737 738 // Handle the full declarator list. 739 while (1) { 740 Action::AttrTy *AttrList; 741 // If attributes are present, parse them. 742 if (Tok.is(tok::kw___attribute)) 743 // FIXME: attach attributes too. 744 AttrList = ParseGNUAttributes(); 745 746 // Ask the actions module to compute the type for this declarator. 747 Action::DeclPtrTy Param = 748 Actions.ActOnParamDeclarator(CurScope, ParmDeclarator); 749 750 if (Param && 751 // A missing identifier has already been diagnosed. 752 ParmDeclarator.getIdentifier()) { 753 754 // Scan the argument list looking for the correct param to apply this 755 // type. 756 for (unsigned i = 0; ; ++i) { 757 // C99 6.9.1p6: those declarators shall declare only identifiers from 758 // the identifier list. 759 if (i == FTI.NumArgs) { 760 Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param) 761 << ParmDeclarator.getIdentifier(); 762 break; 763 } 764 765 if (FTI.ArgInfo[i].Ident == ParmDeclarator.getIdentifier()) { 766 // Reject redefinitions of parameters. 767 if (FTI.ArgInfo[i].Param) { 768 Diag(ParmDeclarator.getIdentifierLoc(), 769 diag::err_param_redefinition) 770 << ParmDeclarator.getIdentifier(); 771 } else { 772 FTI.ArgInfo[i].Param = Param; 773 } 774 break; 775 } 776 } 777 } 778 779 // If we don't have a comma, it is either the end of the list (a ';') or 780 // an error, bail out. 781 if (Tok.isNot(tok::comma)) 782 break; 783 784 // Consume the comma. 785 ConsumeToken(); 786 787 // Parse the next declarator. 788 ParmDeclarator.clear(); 789 ParseDeclarator(ParmDeclarator); 790 } 791 792 if (Tok.is(tok::semi)) { 793 ConsumeToken(); 794 } else { 795 Diag(Tok, diag::err_parse_error); 796 // Skip to end of block or statement 797 SkipUntil(tok::semi, true); 798 if (Tok.is(tok::semi)) 799 ConsumeToken(); 800 } 801 } 802 803 // The actions module must verify that all arguments were declared. 804 Actions.ActOnFinishKNRParamDeclarations(CurScope, D, Tok.getLocation()); 805} 806 807 808/// ParseAsmStringLiteral - This is just a normal string-literal, but is not 809/// allowed to be a wide string, and is not subject to character translation. 810/// 811/// [GNU] asm-string-literal: 812/// string-literal 813/// 814Parser::OwningExprResult Parser::ParseAsmStringLiteral() { 815 if (!isTokenStringLiteral()) { 816 Diag(Tok, diag::err_expected_string_literal); 817 return ExprError(); 818 } 819 820 OwningExprResult Res(ParseStringLiteralExpression()); 821 if (Res.isInvalid()) return move(Res); 822 823 // TODO: Diagnose: wide string literal in 'asm' 824 825 return move(Res); 826} 827 828/// ParseSimpleAsm 829/// 830/// [GNU] simple-asm-expr: 831/// 'asm' '(' asm-string-literal ')' 832/// 833Parser::OwningExprResult Parser::ParseSimpleAsm(SourceLocation *EndLoc) { 834 assert(Tok.is(tok::kw_asm) && "Not an asm!"); 835 SourceLocation Loc = ConsumeToken(); 836 837 if (Tok.isNot(tok::l_paren)) { 838 Diag(Tok, diag::err_expected_lparen_after) << "asm"; 839 return ExprError(); 840 } 841 842 Loc = ConsumeParen(); 843 844 OwningExprResult Result(ParseAsmStringLiteral()); 845 846 if (Result.isInvalid()) { 847 SkipUntil(tok::r_paren, true, true); 848 if (EndLoc) 849 *EndLoc = Tok.getLocation(); 850 ConsumeAnyToken(); 851 } else { 852 Loc = MatchRHSPunctuation(tok::r_paren, Loc); 853 if (EndLoc) 854 *EndLoc = Loc; 855 } 856 857 return move(Result); 858} 859 860/// TryAnnotateTypeOrScopeToken - If the current token position is on a 861/// typename (possibly qualified in C++) or a C++ scope specifier not followed 862/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens 863/// with a single annotation token representing the typename or C++ scope 864/// respectively. 865/// This simplifies handling of C++ scope specifiers and allows efficient 866/// backtracking without the need to re-parse and resolve nested-names and 867/// typenames. 868/// It will mainly be called when we expect to treat identifiers as typenames 869/// (if they are typenames). For example, in C we do not expect identifiers 870/// inside expressions to be treated as typenames so it will not be called 871/// for expressions in C. 872/// The benefit for C/ObjC is that a typename will be annotated and 873/// Actions.getTypeName will not be needed to be called again (e.g. getTypeName 874/// will not be called twice, once to check whether we have a declaration 875/// specifier, and another one to get the actual type inside 876/// ParseDeclarationSpecifiers). 877/// 878/// This returns true if the token was annotated or an unrecoverable error 879/// occurs. 880/// 881/// Note that this routine emits an error if you call it with ::new or ::delete 882/// as the current tokens, so only call it in contexts where these are invalid. 883bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext) { 884 assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon) 885 || Tok.is(tok::kw_typename) || Tok.is(tok::annot_cxxscope)) && 886 "Cannot be a type or scope token!"); 887 888 if (Tok.is(tok::kw_typename)) { 889 // Parse a C++ typename-specifier, e.g., "typename T::type". 890 // 891 // typename-specifier: 892 // 'typename' '::' [opt] nested-name-specifier identifier 893 // 'typename' '::' [opt] nested-name-specifier template [opt] 894 // simple-template-id 895 SourceLocation TypenameLoc = ConsumeToken(); 896 CXXScopeSpec SS; 897 bool HadNestedNameSpecifier 898 = ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false); 899 if (!HadNestedNameSpecifier) { 900 Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename); 901 return false; 902 } 903 904 TypeResult Ty; 905 if (Tok.is(tok::identifier)) { 906 // FIXME: check whether the next token is '<', first! 907 Ty = Actions.ActOnTypenameType(TypenameLoc, SS, *Tok.getIdentifierInfo(), 908 Tok.getLocation()); 909 } else if (Tok.is(tok::annot_template_id)) { 910 TemplateIdAnnotation *TemplateId 911 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 912 if (TemplateId->Kind == TNK_Function_template) { 913 Diag(Tok, diag::err_typename_refers_to_non_type_template) 914 << Tok.getAnnotationRange(); 915 return false; 916 } 917 918 AnnotateTemplateIdTokenAsType(0); 919 assert(Tok.is(tok::annot_typename) && 920 "AnnotateTemplateIdTokenAsType isn't working properly"); 921 if (Tok.getAnnotationValue()) 922 Ty = Actions.ActOnTypenameType(TypenameLoc, SS, SourceLocation(), 923 Tok.getAnnotationValue()); 924 else 925 Ty = true; 926 } else { 927 Diag(Tok, diag::err_expected_type_name_after_typename) 928 << SS.getRange(); 929 return false; 930 } 931 932 Tok.setKind(tok::annot_typename); 933 Tok.setAnnotationValue(Ty.isInvalid()? 0 : Ty.get()); 934 Tok.setAnnotationEndLoc(Tok.getLocation()); 935 Tok.setLocation(TypenameLoc); 936 PP.AnnotateCachedTokens(Tok); 937 return true; 938 } 939 940 // Remembers whether the token was originally a scope annotation. 941 bool wasScopeAnnotation = Tok.is(tok::annot_cxxscope); 942 943 CXXScopeSpec SS; 944 if (getLang().CPlusPlus) 945 ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext); 946 947 if (Tok.is(tok::identifier)) { 948 // Determine whether the identifier is a type name. 949 if (TypeTy *Ty = Actions.getTypeName(*Tok.getIdentifierInfo(), 950 Tok.getLocation(), CurScope, &SS)) { 951 // This is a typename. Replace the current token in-place with an 952 // annotation type token. 953 Tok.setKind(tok::annot_typename); 954 Tok.setAnnotationValue(Ty); 955 Tok.setAnnotationEndLoc(Tok.getLocation()); 956 if (SS.isNotEmpty()) // it was a C++ qualified type name. 957 Tok.setLocation(SS.getBeginLoc()); 958 959 // In case the tokens were cached, have Preprocessor replace 960 // them with the annotation token. 961 PP.AnnotateCachedTokens(Tok); 962 return true; 963 } 964 965 if (!getLang().CPlusPlus) { 966 // If we're in C, we can't have :: tokens at all (the lexer won't return 967 // them). If the identifier is not a type, then it can't be scope either, 968 // just early exit. 969 return false; 970 } 971 972 // If this is a template-id, annotate with a template-id or type token. 973 if (NextToken().is(tok::less)) { 974 TemplateTy Template; 975 UnqualifiedId TemplateName; 976 TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation()); 977 if (TemplateNameKind TNK 978 = Actions.isTemplateName(CurScope, SS, TemplateName, 979 /*ObjectType=*/0, EnteringContext, 980 Template)) { 981 // Consume the identifier. 982 ConsumeToken(); 983 if (AnnotateTemplateIdToken(Template, TNK, &SS, TemplateName)) { 984 // If an unrecoverable error occurred, we need to return true here, 985 // because the token stream is in a damaged state. We may not return 986 // a valid identifier. 987 return Tok.isNot(tok::identifier); 988 } 989 } 990 } 991 992 // The current token, which is either an identifier or a 993 // template-id, is not part of the annotation. Fall through to 994 // push that token back into the stream and complete the C++ scope 995 // specifier annotation. 996 } 997 998 if (Tok.is(tok::annot_template_id)) { 999 TemplateIdAnnotation *TemplateId 1000 = static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue()); 1001 if (TemplateId->Kind == TNK_Type_template) { 1002 // A template-id that refers to a type was parsed into a 1003 // template-id annotation in a context where we weren't allowed 1004 // to produce a type annotation token. Update the template-id 1005 // annotation token to a type annotation token now. 1006 AnnotateTemplateIdTokenAsType(&SS); 1007 return true; 1008 } 1009 } 1010 1011 if (SS.isEmpty()) 1012 return Tok.isNot(tok::identifier) && Tok.isNot(tok::coloncolon); 1013 1014 // A C++ scope specifier that isn't followed by a typename. 1015 // Push the current token back into the token stream (or revert it if it is 1016 // cached) and use an annotation scope token for current token. 1017 if (PP.isBacktrackEnabled()) 1018 PP.RevertCachedTokens(1); 1019 else 1020 PP.EnterToken(Tok); 1021 Tok.setKind(tok::annot_cxxscope); 1022 Tok.setAnnotationValue(SS.getScopeRep()); 1023 Tok.setAnnotationRange(SS.getRange()); 1024 1025 // In case the tokens were cached, have Preprocessor replace them 1026 // with the annotation token. We don't need to do this if we've 1027 // just reverted back to the state we were in before being called. 1028 if (!wasScopeAnnotation) 1029 PP.AnnotateCachedTokens(Tok); 1030 return true; 1031} 1032 1033/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only 1034/// annotates C++ scope specifiers and template-ids. This returns 1035/// true if the token was annotated or there was an error that could not be 1036/// recovered from. 1037/// 1038/// Note that this routine emits an error if you call it with ::new or ::delete 1039/// as the current tokens, so only call it in contexts where these are invalid. 1040bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) { 1041 assert(getLang().CPlusPlus && 1042 "Call sites of this function should be guarded by checking for C++"); 1043 assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon)) && 1044 "Cannot be a type or scope token!"); 1045 1046 CXXScopeSpec SS; 1047 if (!ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext)) 1048 // If the token left behind is not an identifier, we either had an error or 1049 // successfully turned it into an annotation token. 1050 return Tok.isNot(tok::identifier); 1051 1052 // Push the current token back into the token stream (or revert it if it is 1053 // cached) and use an annotation scope token for current token. 1054 if (PP.isBacktrackEnabled()) 1055 PP.RevertCachedTokens(1); 1056 else 1057 PP.EnterToken(Tok); 1058 Tok.setKind(tok::annot_cxxscope); 1059 Tok.setAnnotationValue(SS.getScopeRep()); 1060 Tok.setAnnotationRange(SS.getRange()); 1061 1062 // In case the tokens were cached, have Preprocessor replace them with the 1063 // annotation token. 1064 PP.AnnotateCachedTokens(Tok); 1065 return true; 1066} 1067 1068// Anchor the Parser::FieldCallback vtable to this translation unit. 1069// We use a spurious method instead of the destructor because 1070// destroying FieldCallbacks can actually be slightly 1071// performance-sensitive. 1072void Parser::FieldCallback::_anchor() { 1073} 1074