Preprocessor.h revision 3437f1f1294499d4ef306c1089fcb3e29ec2aa68
1//===--- Preprocessor.h - C Language Family Preprocessor --------*- C++ -*-===// 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 defines the Preprocessor interface. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_CLANG_LEX_PREPROCESSOR_H 15#define LLVM_CLANG_LEX_PREPROCESSOR_H 16 17#include "clang/Lex/MacroInfo.h" 18#include "clang/Lex/Lexer.h" 19#include "clang/Lex/PTHLexer.h" 20#include "clang/Lex/PPCallbacks.h" 21#include "clang/Lex/TokenLexer.h" 22#include "clang/Lex/PTHManager.h" 23#include "clang/Basic/Builtins.h" 24#include "clang/Basic/Diagnostic.h" 25#include "clang/Basic/IdentifierTable.h" 26#include "clang/Basic/SourceLocation.h" 27#include "llvm/ADT/DenseMap.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/ADT/OwningPtr.h" 30#include "llvm/ADT/SmallVector.h" 31#include "llvm/Support/Allocator.h" 32#include <vector> 33 34namespace clang { 35 36class SourceManager; 37class ExternalPreprocessorSource; 38class FileManager; 39class FileEntry; 40class HeaderSearch; 41class PragmaNamespace; 42class PragmaHandler; 43class CommentHandler; 44class ScratchBuffer; 45class TargetInfo; 46class PPCallbacks; 47class CodeCompletionHandler; 48class DirectoryLookup; 49class PreprocessingRecord; 50 51/// Preprocessor - This object engages in a tight little dance with the lexer to 52/// efficiently preprocess tokens. Lexers know only about tokens within a 53/// single source file, and don't know anything about preprocessor-level issues 54/// like the #include stack, token expansion, etc. 55/// 56class Preprocessor { 57 Diagnostic *Diags; 58 LangOptions Features; 59 const TargetInfo &Target; 60 FileManager &FileMgr; 61 SourceManager &SourceMgr; 62 ScratchBuffer *ScratchBuf; 63 HeaderSearch &HeaderInfo; 64 65 /// \brief External source of macros. 66 ExternalPreprocessorSource *ExternalSource; 67 68 /// PTH - An optional PTHManager object used for getting tokens from 69 /// a token cache rather than lexing the original source file. 70 llvm::OwningPtr<PTHManager> PTH; 71 72 /// BP - A BumpPtrAllocator object used to quickly allocate and release 73 /// objects internal to the Preprocessor. 74 llvm::BumpPtrAllocator BP; 75 76 /// Identifiers for builtin macros and other builtins. 77 IdentifierInfo *Ident__LINE__, *Ident__FILE__; // __LINE__, __FILE__ 78 IdentifierInfo *Ident__DATE__, *Ident__TIME__; // __DATE__, __TIME__ 79 IdentifierInfo *Ident__INCLUDE_LEVEL__; // __INCLUDE_LEVEL__ 80 IdentifierInfo *Ident__BASE_FILE__; // __BASE_FILE__ 81 IdentifierInfo *Ident__TIMESTAMP__; // __TIMESTAMP__ 82 IdentifierInfo *Ident__COUNTER__; // __COUNTER__ 83 IdentifierInfo *Ident_Pragma, *Ident__pragma; // _Pragma, __pragma 84 IdentifierInfo *Ident__VA_ARGS__; // __VA_ARGS__ 85 IdentifierInfo *Ident__has_feature; // __has_feature 86 IdentifierInfo *Ident__has_builtin; // __has_builtin 87 IdentifierInfo *Ident__has_attribute; // __has_attribute 88 IdentifierInfo *Ident__has_include; // __has_include 89 IdentifierInfo *Ident__has_include_next; // __has_include_next 90 91 SourceLocation DATELoc, TIMELoc; 92 unsigned CounterValue; // Next __COUNTER__ value. 93 94 enum { 95 /// MaxIncludeStackDepth - Maximum depth of #includes. 96 MaxAllowedIncludeStackDepth = 200 97 }; 98 99 // State that is set before the preprocessor begins. 100 bool KeepComments : 1; 101 bool KeepMacroComments : 1; 102 103 // State that changes while the preprocessor runs: 104 bool InMacroArgs : 1; // True if parsing fn macro invocation args. 105 106 /// Whether the preprocessor owns the header search object. 107 bool OwnsHeaderSearch : 1; 108 109 /// DisableMacroExpansion - True if macro expansion is disabled. 110 bool DisableMacroExpansion : 1; 111 112 /// \brief Whether we have already loaded macros from the external source. 113 mutable bool ReadMacrosFromExternalSource : 1; 114 115 /// Identifiers - This is mapping/lookup information for all identifiers in 116 /// the program, including program keywords. 117 mutable IdentifierTable Identifiers; 118 119 /// Selectors - This table contains all the selectors in the program. Unlike 120 /// IdentifierTable above, this table *isn't* populated by the preprocessor. 121 /// It is declared/instantiated here because it's role/lifetime is 122 /// conceptually similar the IdentifierTable. In addition, the current control 123 /// flow (in clang::ParseAST()), make it convenient to put here. 124 /// FIXME: Make sure the lifetime of Identifiers/Selectors *isn't* tied to 125 /// the lifetime of the preprocessor. 126 SelectorTable Selectors; 127 128 /// BuiltinInfo - Information about builtins. 129 Builtin::Context BuiltinInfo; 130 131 /// PragmaHandlers - This tracks all of the pragmas that the client registered 132 /// with this preprocessor. 133 PragmaNamespace *PragmaHandlers; 134 135 /// \brief Tracks all of the comment handlers that the client registered 136 /// with this preprocessor. 137 std::vector<CommentHandler *> CommentHandlers; 138 139 /// \brief The code-completion handler. 140 CodeCompletionHandler *CodeComplete; 141 142 /// \brief The file that we're performing code-completion for, if any. 143 const FileEntry *CodeCompletionFile; 144 145 /// \brief The number of bytes that we will initially skip when entering the 146 /// main file, which is used when loading a precompiled preamble, along 147 /// with a flag that indicates whether skipping this number of bytes will 148 /// place the lexer at the start of a line. 149 std::pair<unsigned, bool> SkipMainFilePreamble; 150 151 /// CurLexer - This is the current top of the stack that we're lexing from if 152 /// not expanding a macro and we are lexing directly from source code. 153 /// Only one of CurLexer, CurPTHLexer, or CurTokenLexer will be non-null. 154 llvm::OwningPtr<Lexer> CurLexer; 155 156 /// CurPTHLexer - This is the current top of stack that we're lexing from if 157 /// not expanding from a macro and we are lexing from a PTH cache. 158 /// Only one of CurLexer, CurPTHLexer, or CurTokenLexer will be non-null. 159 llvm::OwningPtr<PTHLexer> CurPTHLexer; 160 161 /// CurPPLexer - This is the current top of the stack what we're lexing from 162 /// if not expanding a macro. This is an alias for either CurLexer or 163 /// CurPTHLexer. 164 PreprocessorLexer *CurPPLexer; 165 166 /// CurLookup - The DirectoryLookup structure used to find the current 167 /// FileEntry, if CurLexer is non-null and if applicable. This allows us to 168 /// implement #include_next and find directory-specific properties. 169 const DirectoryLookup *CurDirLookup; 170 171 /// CurTokenLexer - This is the current macro we are expanding, if we are 172 /// expanding a macro. One of CurLexer and CurTokenLexer must be null. 173 llvm::OwningPtr<TokenLexer> CurTokenLexer; 174 175 /// IncludeMacroStack - This keeps track of the stack of files currently 176 /// #included, and macros currently being expanded from, not counting 177 /// CurLexer/CurTokenLexer. 178 struct IncludeStackInfo { 179 Lexer *TheLexer; 180 PTHLexer *ThePTHLexer; 181 PreprocessorLexer *ThePPLexer; 182 TokenLexer *TheTokenLexer; 183 const DirectoryLookup *TheDirLookup; 184 185 IncludeStackInfo(Lexer *L, PTHLexer* P, PreprocessorLexer* PPL, 186 TokenLexer* TL, const DirectoryLookup *D) 187 : TheLexer(L), ThePTHLexer(P), ThePPLexer(PPL), TheTokenLexer(TL), 188 TheDirLookup(D) {} 189 }; 190 std::vector<IncludeStackInfo> IncludeMacroStack; 191 192 /// Callbacks - These are actions invoked when some preprocessor activity is 193 /// encountered (e.g. a file is #included, etc). 194 PPCallbacks *Callbacks; 195 196 /// Macros - For each IdentifierInfo with 'HasMacro' set, we keep a mapping 197 /// to the actual definition of the macro. 198 llvm::DenseMap<IdentifierInfo*, MacroInfo*> Macros; 199 200 /// \brief Macros that we want to warn because they are not used at the end 201 /// of the translation unit; we store just their SourceLocations instead 202 /// something like MacroInfo*. The benefit of this is that when we are 203 /// deserializing from PCH, we don't need to deserialize identifier & macros 204 /// just so that we can report that they are unused, we just warn using 205 /// the SourceLocations of this set (that will be filled by the ASTReader). 206 /// We are using SmallPtrSet instead of a vector for faster removal. 207 typedef llvm::SmallPtrSet<SourceLocation, 32> WarnUnusedMacroLocsTy; 208 WarnUnusedMacroLocsTy WarnUnusedMacroLocs; 209 210 /// MacroArgCache - This is a "freelist" of MacroArg objects that can be 211 /// reused for quick allocation. 212 MacroArgs *MacroArgCache; 213 friend class MacroArgs; 214 215 /// PragmaPushMacroInfo - For each IdentifierInfo used in a #pragma 216 /// push_macro directive, we keep a MacroInfo stack used to restore 217 /// previous macro value. 218 llvm::DenseMap<IdentifierInfo*, std::vector<MacroInfo*> > PragmaPushMacroInfo; 219 220 // Various statistics we track for performance analysis. 221 unsigned NumDirectives, NumIncluded, NumDefined, NumUndefined, NumPragma; 222 unsigned NumIf, NumElse, NumEndif; 223 unsigned NumEnteredSourceFiles, MaxIncludeStackDepth; 224 unsigned NumMacroExpanded, NumFnMacroExpanded, NumBuiltinMacroExpanded; 225 unsigned NumFastMacroExpanded, NumTokenPaste, NumFastTokenPaste; 226 unsigned NumSkipped; 227 228 /// Predefines - This string is the predefined macros that preprocessor 229 /// should use from the command line etc. 230 std::string Predefines; 231 232 /// TokenLexerCache - Cache macro expanders to reduce malloc traffic. 233 enum { TokenLexerCacheSize = 8 }; 234 unsigned NumCachedTokenLexers; 235 TokenLexer *TokenLexerCache[TokenLexerCacheSize]; 236 237 /// \brief A record of the macro definitions and instantiations that 238 /// occurred during preprocessing. 239 /// 240 /// This is an optional side structure that can be enabled with 241 /// \c createPreprocessingRecord() prior to preprocessing. 242 PreprocessingRecord *Record; 243 244private: // Cached tokens state. 245 typedef llvm::SmallVector<Token, 1> CachedTokensTy; 246 247 /// CachedTokens - Cached tokens are stored here when we do backtracking or 248 /// lookahead. They are "lexed" by the CachingLex() method. 249 CachedTokensTy CachedTokens; 250 251 /// CachedLexPos - The position of the cached token that CachingLex() should 252 /// "lex" next. If it points beyond the CachedTokens vector, it means that 253 /// a normal Lex() should be invoked. 254 CachedTokensTy::size_type CachedLexPos; 255 256 /// BacktrackPositions - Stack of backtrack positions, allowing nested 257 /// backtracks. The EnableBacktrackAtThisPos() method pushes a position to 258 /// indicate where CachedLexPos should be set when the BackTrack() method is 259 /// invoked (at which point the last position is popped). 260 std::vector<CachedTokensTy::size_type> BacktrackPositions; 261 262 struct MacroInfoChain { 263 MacroInfo MI; 264 MacroInfoChain *Next; 265 MacroInfoChain *Prev; 266 }; 267 268 /// MacroInfos are managed as a chain for easy disposal. This is the head 269 /// of that list. 270 MacroInfoChain *MIChainHead; 271 272 /// MICache - A "freelist" of MacroInfo objects that can be reused for quick 273 /// allocation. 274 MacroInfoChain *MICache; 275 276 MacroInfo *getInfoForMacro(IdentifierInfo *II) const; 277 278public: 279 Preprocessor(Diagnostic &diags, const LangOptions &opts, 280 const TargetInfo &target, 281 SourceManager &SM, HeaderSearch &Headers, 282 IdentifierInfoLookup *IILookup = 0, 283 bool OwnsHeaderSearch = false); 284 285 ~Preprocessor(); 286 287 Diagnostic &getDiagnostics() const { return *Diags; } 288 void setDiagnostics(Diagnostic &D) { Diags = &D; } 289 290 const LangOptions &getLangOptions() const { return Features; } 291 const TargetInfo &getTargetInfo() const { return Target; } 292 FileManager &getFileManager() const { return FileMgr; } 293 SourceManager &getSourceManager() const { return SourceMgr; } 294 HeaderSearch &getHeaderSearchInfo() const { return HeaderInfo; } 295 296 IdentifierTable &getIdentifierTable() { return Identifiers; } 297 SelectorTable &getSelectorTable() { return Selectors; } 298 Builtin::Context &getBuiltinInfo() { return BuiltinInfo; } 299 llvm::BumpPtrAllocator &getPreprocessorAllocator() { return BP; } 300 301 void setPTHManager(PTHManager* pm); 302 303 PTHManager *getPTHManager() { return PTH.get(); } 304 305 void setExternalSource(ExternalPreprocessorSource *Source) { 306 ExternalSource = Source; 307 } 308 309 ExternalPreprocessorSource *getExternalSource() const { 310 return ExternalSource; 311 } 312 313 /// SetCommentRetentionState - Control whether or not the preprocessor retains 314 /// comments in output. 315 void SetCommentRetentionState(bool KeepComments, bool KeepMacroComments) { 316 this->KeepComments = KeepComments | KeepMacroComments; 317 this->KeepMacroComments = KeepMacroComments; 318 } 319 320 bool getCommentRetentionState() const { return KeepComments; } 321 322 /// isCurrentLexer - Return true if we are lexing directly from the specified 323 /// lexer. 324 bool isCurrentLexer(const PreprocessorLexer *L) const { 325 return CurPPLexer == L; 326 } 327 328 /// getCurrentLexer - Return the current lexer being lexed from. Note 329 /// that this ignores any potentially active macro expansions and _Pragma 330 /// expansions going on at the time. 331 PreprocessorLexer *getCurrentLexer() const { return CurPPLexer; } 332 333 /// getCurrentFileLexer - Return the current file lexer being lexed from. 334 /// Note that this ignores any potentially active macro expansions and _Pragma 335 /// expansions going on at the time. 336 PreprocessorLexer *getCurrentFileLexer() const; 337 338 /// getPPCallbacks/addPPCallbacks - Accessors for preprocessor callbacks. 339 /// Note that this class takes ownership of any PPCallbacks object given to 340 /// it. 341 PPCallbacks *getPPCallbacks() const { return Callbacks; } 342 void addPPCallbacks(PPCallbacks *C) { 343 if (Callbacks) 344 C = new PPChainedCallbacks(C, Callbacks); 345 Callbacks = C; 346 } 347 348 /// getMacroInfo - Given an identifier, return the MacroInfo it is #defined to 349 /// or null if it isn't #define'd. 350 MacroInfo *getMacroInfo(IdentifierInfo *II) const { 351 if (!II->hasMacroDefinition()) 352 return 0; 353 354 return getInfoForMacro(II); 355 } 356 357 /// setMacroInfo - Specify a macro for this identifier. 358 /// 359 void setMacroInfo(IdentifierInfo *II, MacroInfo *MI); 360 361 /// macro_iterator/macro_begin/macro_end - This allows you to walk the current 362 /// state of the macro table. This visits every currently-defined macro. 363 typedef llvm::DenseMap<IdentifierInfo*, 364 MacroInfo*>::const_iterator macro_iterator; 365 macro_iterator macro_begin(bool IncludeExternalMacros = true) const; 366 macro_iterator macro_end(bool IncludeExternalMacros = true) const; 367 368 const std::string &getPredefines() const { return Predefines; } 369 /// setPredefines - Set the predefines for this Preprocessor. These 370 /// predefines are automatically injected when parsing the main file. 371 void setPredefines(const char *P) { Predefines = P; } 372 void setPredefines(const std::string &P) { Predefines = P; } 373 374 /// getIdentifierInfo - Return information about the specified preprocessor 375 /// identifier token. The version of this method that takes two character 376 /// pointers is preferred unless the identifier is already available as a 377 /// string (this avoids allocation and copying of memory to construct an 378 /// std::string). 379 IdentifierInfo *getIdentifierInfo(llvm::StringRef Name) const { 380 return &Identifiers.get(Name); 381 } 382 383 /// AddPragmaHandler - Add the specified pragma handler to the preprocessor. 384 /// If 'Namespace' is non-null, then it is a token required to exist on the 385 /// pragma line before the pragma string starts, e.g. "STDC" or "GCC". 386 void AddPragmaHandler(llvm::StringRef Namespace, PragmaHandler *Handler); 387 void AddPragmaHandler(PragmaHandler *Handler) { 388 AddPragmaHandler(llvm::StringRef(), Handler); 389 } 390 391 /// RemovePragmaHandler - Remove the specific pragma handler from 392 /// the preprocessor. If \arg Namespace is non-null, then it should 393 /// be the namespace that \arg Handler was added to. It is an error 394 /// to remove a handler that has not been registered. 395 void RemovePragmaHandler(llvm::StringRef Namespace, PragmaHandler *Handler); 396 void RemovePragmaHandler(PragmaHandler *Handler) { 397 RemovePragmaHandler(llvm::StringRef(), Handler); 398 } 399 400 /// \brief Add the specified comment handler to the preprocessor. 401 void AddCommentHandler(CommentHandler *Handler); 402 403 /// \brief Remove the specified comment handler. 404 /// 405 /// It is an error to remove a handler that has not been registered. 406 void RemoveCommentHandler(CommentHandler *Handler); 407 408 /// \brief Set the code completion handler to the given object. 409 void setCodeCompletionHandler(CodeCompletionHandler &Handler) { 410 CodeComplete = &Handler; 411 } 412 413 /// \brief Retrieve the current code-completion handler. 414 CodeCompletionHandler *getCodeCompletionHandler() const { 415 return CodeComplete; 416 } 417 418 /// \brief Clear out the code completion handler. 419 void clearCodeCompletionHandler() { 420 CodeComplete = 0; 421 } 422 423 /// \brief Hook used by the lexer to invoke the "natural language" code 424 /// completion point. 425 void CodeCompleteNaturalLanguage(); 426 427 /// \brief Retrieve the preprocessing record, or NULL if there is no 428 /// preprocessing record. 429 PreprocessingRecord *getPreprocessingRecord() const { return Record; } 430 431 /// \brief Create a new preprocessing record, which will keep track of 432 /// all macro expansions, macro definitions, etc. 433 void createPreprocessingRecord(); 434 435 /// EnterMainSourceFile - Enter the specified FileID as the main source file, 436 /// which implicitly adds the builtin defines etc. 437 void EnterMainSourceFile(); 438 439 /// EndSourceFile - Inform the preprocessor callbacks that processing is 440 /// complete. 441 void EndSourceFile(); 442 443 /// EnterSourceFile - Add a source file to the top of the include stack and 444 /// start lexing tokens from it instead of the current buffer. Emit an error 445 /// and don't enter the file on error. 446 void EnterSourceFile(FileID CurFileID, const DirectoryLookup *Dir, 447 SourceLocation Loc); 448 449 /// EnterMacro - Add a Macro to the top of the include stack and start lexing 450 /// tokens from it instead of the current buffer. Args specifies the 451 /// tokens input to a function-like macro. 452 /// 453 /// ILEnd specifies the location of the ')' for a function-like macro or the 454 /// identifier for an object-like macro. 455 void EnterMacro(Token &Identifier, SourceLocation ILEnd, MacroArgs *Args); 456 457 /// EnterTokenStream - Add a "macro" context to the top of the include stack, 458 /// which will cause the lexer to start returning the specified tokens. 459 /// 460 /// If DisableMacroExpansion is true, tokens lexed from the token stream will 461 /// not be subject to further macro expansion. Otherwise, these tokens will 462 /// be re-macro-expanded when/if expansion is enabled. 463 /// 464 /// If OwnsTokens is false, this method assumes that the specified stream of 465 /// tokens has a permanent owner somewhere, so they do not need to be copied. 466 /// If it is true, it assumes the array of tokens is allocated with new[] and 467 /// must be freed. 468 /// 469 void EnterTokenStream(const Token *Toks, unsigned NumToks, 470 bool DisableMacroExpansion, bool OwnsTokens); 471 472 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the 473 /// lexer stack. This should only be used in situations where the current 474 /// state of the top-of-stack lexer is known. 475 void RemoveTopOfLexerStack(); 476 477 /// EnableBacktrackAtThisPos - From the point that this method is called, and 478 /// until CommitBacktrackedTokens() or Backtrack() is called, the Preprocessor 479 /// keeps track of the lexed tokens so that a subsequent Backtrack() call will 480 /// make the Preprocessor re-lex the same tokens. 481 /// 482 /// Nested backtracks are allowed, meaning that EnableBacktrackAtThisPos can 483 /// be called multiple times and CommitBacktrackedTokens/Backtrack calls will 484 /// be combined with the EnableBacktrackAtThisPos calls in reverse order. 485 /// 486 /// NOTE: *DO NOT* forget to call either CommitBacktrackedTokens or Backtrack 487 /// at some point after EnableBacktrackAtThisPos. If you don't, caching of 488 /// tokens will continue indefinitely. 489 /// 490 void EnableBacktrackAtThisPos(); 491 492 /// CommitBacktrackedTokens - Disable the last EnableBacktrackAtThisPos call. 493 void CommitBacktrackedTokens(); 494 495 /// Backtrack - Make Preprocessor re-lex the tokens that were lexed since 496 /// EnableBacktrackAtThisPos() was previously called. 497 void Backtrack(); 498 499 /// isBacktrackEnabled - True if EnableBacktrackAtThisPos() was called and 500 /// caching of tokens is on. 501 bool isBacktrackEnabled() const { return !BacktrackPositions.empty(); } 502 503 /// Lex - To lex a token from the preprocessor, just pull a token from the 504 /// current lexer or macro object. 505 void Lex(Token &Result) { 506 if (CurLexer) 507 CurLexer->Lex(Result); 508 else if (CurPTHLexer) 509 CurPTHLexer->Lex(Result); 510 else if (CurTokenLexer) 511 CurTokenLexer->Lex(Result); 512 else 513 CachingLex(Result); 514 } 515 516 /// LexNonComment - Lex a token. If it's a comment, keep lexing until we get 517 /// something not a comment. This is useful in -E -C mode where comments 518 /// would foul up preprocessor directive handling. 519 void LexNonComment(Token &Result) { 520 do 521 Lex(Result); 522 while (Result.getKind() == tok::comment); 523 } 524 525 /// LexUnexpandedToken - This is just like Lex, but this disables macro 526 /// expansion of identifier tokens. 527 void LexUnexpandedToken(Token &Result) { 528 // Disable macro expansion. 529 bool OldVal = DisableMacroExpansion; 530 DisableMacroExpansion = true; 531 // Lex the token. 532 Lex(Result); 533 534 // Reenable it. 535 DisableMacroExpansion = OldVal; 536 } 537 538 /// LookAhead - This peeks ahead N tokens and returns that token without 539 /// consuming any tokens. LookAhead(0) returns the next token that would be 540 /// returned by Lex(), LookAhead(1) returns the token after it, etc. This 541 /// returns normal tokens after phase 5. As such, it is equivalent to using 542 /// 'Lex', not 'LexUnexpandedToken'. 543 const Token &LookAhead(unsigned N) { 544 if (CachedLexPos + N < CachedTokens.size()) 545 return CachedTokens[CachedLexPos+N]; 546 else 547 return PeekAhead(N+1); 548 } 549 550 /// RevertCachedTokens - When backtracking is enabled and tokens are cached, 551 /// this allows to revert a specific number of tokens. 552 /// Note that the number of tokens being reverted should be up to the last 553 /// backtrack position, not more. 554 void RevertCachedTokens(unsigned N) { 555 assert(isBacktrackEnabled() && 556 "Should only be called when tokens are cached for backtracking"); 557 assert(signed(CachedLexPos) - signed(N) >= signed(BacktrackPositions.back()) 558 && "Should revert tokens up to the last backtrack position, not more"); 559 assert(signed(CachedLexPos) - signed(N) >= 0 && 560 "Corrupted backtrack positions ?"); 561 CachedLexPos -= N; 562 } 563 564 /// EnterToken - Enters a token in the token stream to be lexed next. If 565 /// BackTrack() is called afterwards, the token will remain at the insertion 566 /// point. 567 void EnterToken(const Token &Tok) { 568 EnterCachingLexMode(); 569 CachedTokens.insert(CachedTokens.begin()+CachedLexPos, Tok); 570 } 571 572 /// AnnotateCachedTokens - We notify the Preprocessor that if it is caching 573 /// tokens (because backtrack is enabled) it should replace the most recent 574 /// cached tokens with the given annotation token. This function has no effect 575 /// if backtracking is not enabled. 576 /// 577 /// Note that the use of this function is just for optimization; so that the 578 /// cached tokens doesn't get re-parsed and re-resolved after a backtrack is 579 /// invoked. 580 void AnnotateCachedTokens(const Token &Tok) { 581 assert(Tok.isAnnotation() && "Expected annotation token"); 582 if (CachedLexPos != 0 && isBacktrackEnabled()) 583 AnnotatePreviousCachedTokens(Tok); 584 } 585 586 /// \brief Replace the last token with an annotation token. 587 /// 588 /// Like AnnotateCachedTokens(), this routine replaces an 589 /// already-parsed (and resolved) token with an annotation 590 /// token. However, this routine only replaces the last token with 591 /// the annotation token; it does not affect any other cached 592 /// tokens. This function has no effect if backtracking is not 593 /// enabled. 594 void ReplaceLastTokenWithAnnotation(const Token &Tok) { 595 assert(Tok.isAnnotation() && "Expected annotation token"); 596 if (CachedLexPos != 0 && isBacktrackEnabled()) 597 CachedTokens[CachedLexPos-1] = Tok; 598 } 599 600 /// \brief Specify the point at which code-completion will be performed. 601 /// 602 /// \param File the file in which code completion should occur. If 603 /// this file is included multiple times, code-completion will 604 /// perform completion the first time it is included. If NULL, this 605 /// function clears out the code-completion point. 606 /// 607 /// \param Line the line at which code completion should occur 608 /// (1-based). 609 /// 610 /// \param Column the column at which code completion should occur 611 /// (1-based). 612 /// 613 /// \returns true if an error occurred, false otherwise. 614 bool SetCodeCompletionPoint(const FileEntry *File, 615 unsigned Line, unsigned Column); 616 617 /// \brief Determine if this source location refers into the file 618 /// for which we are performing code completion. 619 bool isCodeCompletionFile(SourceLocation FileLoc) const; 620 621 /// \brief Determine if we are performing code completion. 622 bool isCodeCompletionEnabled() const { return CodeCompletionFile != 0; } 623 624 /// \brief Instruct the preprocessor to skip part of the main 625 /// the main source file. 626 /// 627 /// \brief Bytes The number of bytes in the preamble to skip. 628 /// 629 /// \brief StartOfLine Whether skipping these bytes puts the lexer at the 630 /// start of a line. 631 void setSkipMainFilePreamble(unsigned Bytes, bool StartOfLine) { 632 SkipMainFilePreamble.first = Bytes; 633 SkipMainFilePreamble.second = StartOfLine; 634 } 635 636 /// Diag - Forwarding function for diagnostics. This emits a diagnostic at 637 /// the specified Token's location, translating the token's start 638 /// position in the current buffer into a SourcePosition object for rendering. 639 DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) { 640 return Diags->Report(Loc, DiagID); 641 } 642 643 DiagnosticBuilder Diag(const Token &Tok, unsigned DiagID) { 644 return Diags->Report(Tok.getLocation(), DiagID); 645 } 646 647 /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a 648 /// token is the characters used to represent the token in the source file 649 /// after trigraph expansion and escaped-newline folding. In particular, this 650 /// wants to get the true, uncanonicalized, spelling of things like digraphs 651 /// UCNs, etc. 652 /// 653 /// \param Invalid If non-NULL, will be set \c true if an error occurs. 654 std::string getSpelling(const Token &Tok, bool *Invalid = 0) const { 655 return Lexer::getSpelling(Tok, SourceMgr, Features, Invalid); 656 } 657 658 /// getSpelling - This method is used to get the spelling of a token into a 659 /// preallocated buffer, instead of as an std::string. The caller is required 660 /// to allocate enough space for the token, which is guaranteed to be at least 661 /// Tok.getLength() bytes long. The length of the actual result is returned. 662 /// 663 /// Note that this method may do two possible things: it may either fill in 664 /// the buffer specified with characters, or it may *change the input pointer* 665 /// to point to a constant buffer with the data already in it (avoiding a 666 /// copy). The caller is not allowed to modify the returned buffer pointer 667 /// if an internal buffer is returned. 668 unsigned getSpelling(const Token &Tok, const char *&Buffer, 669 bool *Invalid = 0) const { 670 return Lexer::getSpelling(Tok, Buffer, SourceMgr, Features, Invalid); 671 } 672 673 /// getSpelling - This method is used to get the spelling of a token into a 674 /// SmallVector. Note that the returned StringRef may not point to the 675 /// supplied buffer if a copy can be avoided. 676 llvm::StringRef getSpelling(const Token &Tok, 677 llvm::SmallVectorImpl<char> &Buffer, 678 bool *Invalid = 0) const; 679 680 /// getSpellingOfSingleCharacterNumericConstant - Tok is a numeric constant 681 /// with length 1, return the character. 682 char getSpellingOfSingleCharacterNumericConstant(const Token &Tok, 683 bool *Invalid = 0) const { 684 assert(Tok.is(tok::numeric_constant) && 685 Tok.getLength() == 1 && "Called on unsupported token"); 686 assert(!Tok.needsCleaning() && "Token can't need cleaning with length 1"); 687 688 // If the token is carrying a literal data pointer, just use it. 689 if (const char *D = Tok.getLiteralData()) 690 return *D; 691 692 // Otherwise, fall back on getCharacterData, which is slower, but always 693 // works. 694 return *SourceMgr.getCharacterData(Tok.getLocation(), Invalid); 695 } 696 697 /// CreateString - Plop the specified string into a scratch buffer and set the 698 /// specified token's location and length to it. If specified, the source 699 /// location provides a location of the instantiation point of the token. 700 void CreateString(const char *Buf, unsigned Len, 701 Token &Tok, SourceLocation SourceLoc = SourceLocation()); 702 703 /// \brief Computes the source location just past the end of the 704 /// token at this source location. 705 /// 706 /// This routine can be used to produce a source location that 707 /// points just past the end of the token referenced by \p Loc, and 708 /// is generally used when a diagnostic needs to point just after a 709 /// token where it expected something different that it received. If 710 /// the returned source location would not be meaningful (e.g., if 711 /// it points into a macro), this routine returns an invalid 712 /// source location. 713 /// 714 /// \param Offset an offset from the end of the token, where the source 715 /// location should refer to. The default offset (0) produces a source 716 /// location pointing just past the end of the token; an offset of 1 produces 717 /// a source location pointing to the last character in the token, etc. 718 SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0) { 719 return Lexer::getLocForEndOfToken(Loc, Offset, SourceMgr, Features); 720 } 721 722 /// DumpToken - Print the token to stderr, used for debugging. 723 /// 724 void DumpToken(const Token &Tok, bool DumpFlags = false) const; 725 void DumpLocation(SourceLocation Loc) const; 726 void DumpMacro(const MacroInfo &MI) const; 727 728 /// AdvanceToTokenCharacter - Given a location that specifies the start of a 729 /// token, return a new location that specifies a character within the token. 730 SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart, 731 unsigned Char) const { 732 return Lexer::AdvanceToTokenCharacter(TokStart, Char, SourceMgr, Features); 733 } 734 735 /// IncrementPasteCounter - Increment the counters for the number of token 736 /// paste operations performed. If fast was specified, this is a 'fast paste' 737 /// case we handled. 738 /// 739 void IncrementPasteCounter(bool isFast) { 740 if (isFast) 741 ++NumFastTokenPaste; 742 else 743 ++NumTokenPaste; 744 } 745 746 void PrintStats(); 747 748 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a 749 /// comment (/##/) in microsoft mode, this method handles updating the current 750 /// state, returning the token on the next source line. 751 void HandleMicrosoftCommentPaste(Token &Tok); 752 753 //===--------------------------------------------------------------------===// 754 // Preprocessor callback methods. These are invoked by a lexer as various 755 // directives and events are found. 756 757 /// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the 758 /// identifier information for the token and install it into the token, 759 /// updating the token kind accordingly. 760 IdentifierInfo *LookUpIdentifierInfo(Token &Identifier) const; 761 762 /// HandleIdentifier - This callback is invoked when the lexer reads an 763 /// identifier and has filled in the tokens IdentifierInfo member. This 764 /// callback potentially macro expands it or turns it into a named token (like 765 /// 'for'). 766 void HandleIdentifier(Token &Identifier); 767 768 769 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of 770 /// the current file. This either returns the EOF token and returns true, or 771 /// pops a level off the include stack and returns false, at which point the 772 /// client should call lex again. 773 bool HandleEndOfFile(Token &Result, bool isEndOfMacro = false); 774 775 /// HandleEndOfTokenLexer - This callback is invoked when the current 776 /// TokenLexer hits the end of its token stream. 777 bool HandleEndOfTokenLexer(Token &Result); 778 779 /// HandleDirective - This callback is invoked when the lexer sees a # token 780 /// at the start of a line. This consumes the directive, modifies the 781 /// lexer/preprocessor state, and advances the lexer(s) so that the next token 782 /// read is the correct one. 783 void HandleDirective(Token &Result); 784 785 /// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If 786 /// not, emit a diagnostic and consume up until the eom. If EnableMacros is 787 /// true, then we consider macros that expand to zero tokens as being ok. 788 void CheckEndOfDirective(const char *Directive, bool EnableMacros = false); 789 790 /// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the 791 /// current line until the tok::eom token is found. 792 void DiscardUntilEndOfDirective(); 793 794 /// SawDateOrTime - This returns true if the preprocessor has seen a use of 795 /// __DATE__ or __TIME__ in the file so far. 796 bool SawDateOrTime() const { 797 return DATELoc != SourceLocation() || TIMELoc != SourceLocation(); 798 } 799 unsigned getCounterValue() const { return CounterValue; } 800 void setCounterValue(unsigned V) { CounterValue = V; } 801 802 /// AllocateMacroInfo - Allocate a new MacroInfo object with the provide 803 /// SourceLocation. 804 MacroInfo *AllocateMacroInfo(SourceLocation L); 805 806 /// CloneMacroInfo - Allocate a new MacroInfo object which is clone of MI. 807 MacroInfo *CloneMacroInfo(const MacroInfo &MI); 808 809 /// GetIncludeFilenameSpelling - Turn the specified lexer token into a fully 810 /// checked and spelled filename, e.g. as an operand of #include. This returns 811 /// true if the input filename was in <>'s or false if it were in ""'s. The 812 /// caller is expected to provide a buffer that is large enough to hold the 813 /// spelling of the filename, but is also expected to handle the case when 814 /// this method decides to use a different buffer. 815 bool GetIncludeFilenameSpelling(SourceLocation Loc,llvm::StringRef &Filename); 816 817 /// LookupFile - Given a "foo" or <foo> reference, look up the indicated file, 818 /// return null on failure. isAngled indicates whether the file reference is 819 /// for system #include's or not (i.e. using <> instead of ""). 820 const FileEntry *LookupFile(llvm::StringRef Filename, 821 bool isAngled, const DirectoryLookup *FromDir, 822 const DirectoryLookup *&CurDir); 823 824 /// GetCurLookup - The DirectoryLookup structure used to find the current 825 /// FileEntry, if CurLexer is non-null and if applicable. This allows us to 826 /// implement #include_next and find directory-specific properties. 827 const DirectoryLookup *GetCurDirLookup() { return CurDirLookup; } 828 829 /// isInPrimaryFile - Return true if we're in the top-level file, not in a 830 /// #include. 831 bool isInPrimaryFile() const; 832 833 /// ConcatenateIncludeName - Handle cases where the #include name is expanded 834 /// from a macro as multiple tokens, which need to be glued together. This 835 /// occurs for code like: 836 /// #define FOO <a/b.h> 837 /// #include FOO 838 /// because in this case, "<a/b.h>" is returned as 7 tokens, not one. 839 /// 840 /// This code concatenates and consumes tokens up to the '>' token. It 841 /// returns false if the > was found, otherwise it returns true if it finds 842 /// and consumes the EOM marker. 843 bool ConcatenateIncludeName(llvm::SmallString<128> &FilenameBuffer, 844 SourceLocation &End); 845 846private: 847 848 void PushIncludeMacroStack() { 849 IncludeMacroStack.push_back(IncludeStackInfo(CurLexer.take(), 850 CurPTHLexer.take(), 851 CurPPLexer, 852 CurTokenLexer.take(), 853 CurDirLookup)); 854 CurPPLexer = 0; 855 } 856 857 void PopIncludeMacroStack() { 858 CurLexer.reset(IncludeMacroStack.back().TheLexer); 859 CurPTHLexer.reset(IncludeMacroStack.back().ThePTHLexer); 860 CurPPLexer = IncludeMacroStack.back().ThePPLexer; 861 CurTokenLexer.reset(IncludeMacroStack.back().TheTokenLexer); 862 CurDirLookup = IncludeMacroStack.back().TheDirLookup; 863 IncludeMacroStack.pop_back(); 864 } 865 866 /// AllocateMacroInfo - Allocate a new MacroInfo object. 867 MacroInfo *AllocateMacroInfo(); 868 869 /// ReleaseMacroInfo - Release the specified MacroInfo. This memory will 870 /// be reused for allocating new MacroInfo objects. 871 void ReleaseMacroInfo(MacroInfo* MI); 872 873 /// ReadMacroName - Lex and validate a macro name, which occurs after a 874 /// #define or #undef. This emits a diagnostic, sets the token kind to eom, 875 /// and discards the rest of the macro line if the macro name is invalid. 876 void ReadMacroName(Token &MacroNameTok, char isDefineUndef = 0); 877 878 /// ReadMacroDefinitionArgList - The ( starting an argument list of a macro 879 /// definition has just been read. Lex the rest of the arguments and the 880 /// closing ), updating MI with what we learn. Return true if an error occurs 881 /// parsing the arg list. 882 bool ReadMacroDefinitionArgList(MacroInfo *MI); 883 884 /// SkipExcludedConditionalBlock - We just read a #if or related directive and 885 /// decided that the subsequent tokens are in the #if'd out portion of the 886 /// file. Lex the rest of the file, until we see an #endif. If 887 /// FoundNonSkipPortion is true, then we have already emitted code for part of 888 /// this #if directive, so #else/#elif blocks should never be entered. If 889 /// FoundElse is false, then #else directives are ok, if not, then we have 890 /// already seen one so a #else directive is a duplicate. When this returns, 891 /// the caller can lex the first valid token. 892 void SkipExcludedConditionalBlock(SourceLocation IfTokenLoc, 893 bool FoundNonSkipPortion, bool FoundElse); 894 895 /// PTHSkipExcludedConditionalBlock - A fast PTH version of 896 /// SkipExcludedConditionalBlock. 897 void PTHSkipExcludedConditionalBlock(); 898 899 /// EvaluateDirectiveExpression - Evaluate an integer constant expression that 900 /// may occur after a #if or #elif directive and return it as a bool. If the 901 /// expression is equivalent to "!defined(X)" return X in IfNDefMacro. 902 bool EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro); 903 904 /// RegisterBuiltinPragmas - Install the standard preprocessor pragmas: 905 /// #pragma GCC poison/system_header/dependency and #pragma once. 906 void RegisterBuiltinPragmas(); 907 908 /// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the 909 /// identifier table. 910 void RegisterBuiltinMacros(); 911 912 /// HandleMacroExpandedIdentifier - If an identifier token is read that is to 913 /// be expanded as a macro, handle it and return the next token as 'Tok'. If 914 /// the macro should not be expanded return true, otherwise return false. 915 bool HandleMacroExpandedIdentifier(Token &Tok, MacroInfo *MI); 916 917 /// isNextPPTokenLParen - Determine whether the next preprocessor token to be 918 /// lexed is a '('. If so, consume the token and return true, if not, this 919 /// method should have no observable side-effect on the lexed tokens. 920 bool isNextPPTokenLParen(); 921 922 /// ReadFunctionLikeMacroArgs - After reading "MACRO(", this method is 923 /// invoked to read all of the formal arguments specified for the macro 924 /// invocation. This returns null on error. 925 MacroArgs *ReadFunctionLikeMacroArgs(Token &MacroName, MacroInfo *MI, 926 SourceLocation &InstantiationEnd); 927 928 /// ExpandBuiltinMacro - If an identifier token is read that is to be expanded 929 /// as a builtin macro, handle it and return the next token as 'Tok'. 930 void ExpandBuiltinMacro(Token &Tok); 931 932 /// Handle_Pragma - Read a _Pragma directive, slice it up, process it, then 933 /// return the first token after the directive. The _Pragma token has just 934 /// been read into 'Tok'. 935 void Handle_Pragma(Token &Tok); 936 937 /// HandleMicrosoft__pragma - Like Handle_Pragma except the pragma text 938 /// is not enclosed within a string literal. 939 void HandleMicrosoft__pragma(Token &Tok); 940 941 void Handle_Pragma(unsigned Introducer, const std::string &StrVal, 942 SourceLocation PragmaLoc, SourceLocation RParenLoc); 943 944 /// EnterSourceFileWithLexer - Add a lexer to the top of the include stack and 945 /// start lexing tokens from it instead of the current buffer. 946 void EnterSourceFileWithLexer(Lexer *TheLexer, const DirectoryLookup *Dir); 947 948 /// EnterSourceFileWithPTH - Add a lexer to the top of the include stack and 949 /// start getting tokens from it using the PTH cache. 950 void EnterSourceFileWithPTH(PTHLexer *PL, const DirectoryLookup *Dir); 951 952 /// IsFileLexer - Returns true if we are lexing from a file and not a 953 /// pragma or a macro. 954 static bool IsFileLexer(const Lexer* L, const PreprocessorLexer* P) { 955 return L ? !L->isPragmaLexer() : P != 0; 956 } 957 958 static bool IsFileLexer(const IncludeStackInfo& I) { 959 return IsFileLexer(I.TheLexer, I.ThePPLexer); 960 } 961 962 bool IsFileLexer() const { 963 return IsFileLexer(CurLexer.get(), CurPPLexer); 964 } 965 966 //===--------------------------------------------------------------------===// 967 // Caching stuff. 968 void CachingLex(Token &Result); 969 bool InCachingLexMode() const { 970 // If the Lexer pointers are 0 and IncludeMacroStack is empty, it means 971 // that we are past EOF, not that we are in CachingLex mode. 972 return CurPPLexer == 0 && CurTokenLexer == 0 && CurPTHLexer == 0 && 973 !IncludeMacroStack.empty(); 974 } 975 void EnterCachingLexMode(); 976 void ExitCachingLexMode() { 977 if (InCachingLexMode()) 978 RemoveTopOfLexerStack(); 979 } 980 const Token &PeekAhead(unsigned N); 981 void AnnotatePreviousCachedTokens(const Token &Tok); 982 983 //===--------------------------------------------------------------------===// 984 /// Handle*Directive - implement the various preprocessor directives. These 985 /// should side-effect the current preprocessor object so that the next call 986 /// to Lex() will return the appropriate token next. 987 void HandleLineDirective(Token &Tok); 988 void HandleDigitDirective(Token &Tok); 989 void HandleUserDiagnosticDirective(Token &Tok, bool isWarning); 990 void HandleIdentSCCSDirective(Token &Tok); 991 992 // File inclusion. 993 void HandleIncludeDirective(SourceLocation HashLoc, 994 Token &Tok, 995 const DirectoryLookup *LookupFrom = 0, 996 bool isImport = false); 997 void HandleIncludeNextDirective(SourceLocation HashLoc, Token &Tok); 998 void HandleIncludeMacrosDirective(SourceLocation HashLoc, Token &Tok); 999 void HandleImportDirective(SourceLocation HashLoc, Token &Tok); 1000 1001 // Macro handling. 1002 void HandleDefineDirective(Token &Tok); 1003 void HandleUndefDirective(Token &Tok); 1004 1005 // Conditional Inclusion. 1006 void HandleIfdefDirective(Token &Tok, bool isIfndef, 1007 bool ReadAnyTokensBeforeDirective); 1008 void HandleIfDirective(Token &Tok, bool ReadAnyTokensBeforeDirective); 1009 void HandleEndifDirective(Token &Tok); 1010 void HandleElseDirective(Token &Tok); 1011 void HandleElifDirective(Token &Tok); 1012 1013 // Pragmas. 1014 void HandlePragmaDirective(unsigned Introducer); 1015public: 1016 void HandlePragmaOnce(Token &OnceTok); 1017 void HandlePragmaMark(); 1018 void HandlePragmaPoison(Token &PoisonTok); 1019 void HandlePragmaSystemHeader(Token &SysHeaderTok); 1020 void HandlePragmaDependency(Token &DependencyTok); 1021 void HandlePragmaComment(Token &CommentTok); 1022 void HandlePragmaMessage(Token &MessageTok); 1023 void HandlePragmaPushMacro(Token &Tok); 1024 void HandlePragmaPopMacro(Token &Tok); 1025 IdentifierInfo *ParsePragmaPushOrPopMacro(Token &Tok); 1026 1027 // Return true and store the first token only if any CommentHandler 1028 // has inserted some tokens and getCommentRetentionState() is false. 1029 bool HandleComment(Token &Token, SourceRange Comment); 1030 1031 /// \brief A macro is used, update information about macros that need unused 1032 /// warnings. 1033 void markMacroAsUsed(MacroInfo *MI); 1034}; 1035 1036/// \brief Abstract base class that describes a handler that will receive 1037/// source ranges for each of the comments encountered in the source file. 1038class CommentHandler { 1039public: 1040 virtual ~CommentHandler(); 1041 1042 // The handler shall return true if it has pushed any tokens 1043 // to be read using e.g. EnterToken or EnterTokenStream. 1044 virtual bool HandleComment(Preprocessor &PP, SourceRange Comment) = 0; 1045}; 1046 1047} // end namespace clang 1048 1049#endif 1050