Preprocessor.h revision d217773f106856a11879ec79dc468efefaf2ee75
1//===--- Preprocessor.h - C Language Family Preprocessor --------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by Chris Lattner and is distributed under 6// the University of Illinois Open Source 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/IdentifierTable.h" 18#include "clang/Lex/Lexer.h" 19#include "clang/Lex/MacroExpander.h" 20#include "clang/Basic/SourceLocation.h" 21 22namespace clang { 23 24class SourceManager; 25class FileManager; 26class FileEntry; 27class HeaderSearch; 28class PragmaNamespace; 29class PragmaHandler; 30class ScratchBuffer; 31class TargetInfo; 32class PPCallbacks; 33class DirectoryLookup; 34 35/// Preprocessor - This object forms engages in a tight little dance to 36/// efficiently preprocess tokens. Lexers know only about tokens within a 37/// single source file, and don't know anything about preprocessor-level issues 38/// like the #include stack, token expansion, etc. 39/// 40class Preprocessor { 41 Diagnostic &Diags; 42 const LangOptions &Features; 43 TargetInfo &Target; 44 FileManager &FileMgr; 45 SourceManager &SourceMgr; 46 ScratchBuffer *ScratchBuf; 47 HeaderSearch &HeaderInfo; 48 49 /// Identifiers for builtin macros and other builtins. 50 IdentifierInfo *Ident__LINE__, *Ident__FILE__; // __LINE__, __FILE__ 51 IdentifierInfo *Ident__DATE__, *Ident__TIME__; // __DATE__, __TIME__ 52 IdentifierInfo *Ident__INCLUDE_LEVEL__; // __INCLUDE_LEVEL__ 53 IdentifierInfo *Ident__BASE_FILE__; // __BASE_FILE__ 54 IdentifierInfo *Ident__TIMESTAMP__; // __TIMESTAMP__ 55 IdentifierInfo *Ident_Pragma, *Ident__VA_ARGS__; // _Pragma, __VA_ARGS__ 56 57 SourceLocation DATELoc, TIMELoc; 58 59 enum { 60 /// MaxIncludeStackDepth - Maximum depth of #includes. 61 MaxAllowedIncludeStackDepth = 200 62 }; 63 64 // State that is set before the preprocessor begins. 65 bool KeepComments : 1; 66 bool KeepMacroComments : 1; 67 68 // State that changes while the preprocessor runs: 69 bool DisableMacroExpansion : 1; // True if macro expansion is disabled. 70 bool InMacroArgs : 1; // True if parsing fn macro invocation args. 71 72 /// Identifiers - This is mapping/lookup information for all identifiers in 73 /// the program, including program keywords. 74 IdentifierTable Identifiers; 75 76 /// PragmaHandlers - This tracks all of the pragmas that the client registered 77 /// with this preprocessor. 78 PragmaNamespace *PragmaHandlers; 79 80 /// CurLexer - This is the current top of the stack that we're lexing from if 81 /// not expanding a macro. One of CurLexer and CurMacroExpander must be null. 82 Lexer *CurLexer; 83 84 /// CurLookup - The DirectoryLookup structure used to find the current 85 /// FileEntry, if CurLexer is non-null and if applicable. This allows us to 86 /// implement #include_next and find directory-specific properties. 87 const DirectoryLookup *CurDirLookup; 88 89 /// CurMacroExpander - This is the current macro we are expanding, if we are 90 /// expanding a macro. One of CurLexer and CurMacroExpander must be null. 91 MacroExpander *CurMacroExpander; 92 93 /// IncludeMacroStack - This keeps track of the stack of files currently 94 /// #included, and macros currently being expanded from, not counting 95 /// CurLexer/CurMacroExpander. 96 struct IncludeStackInfo { 97 Lexer *TheLexer; 98 const DirectoryLookup *TheDirLookup; 99 MacroExpander *TheMacroExpander; 100 IncludeStackInfo(Lexer *L, const DirectoryLookup *D, MacroExpander *M) 101 : TheLexer(L), TheDirLookup(D), TheMacroExpander(M) { 102 } 103 }; 104 std::vector<IncludeStackInfo> IncludeMacroStack; 105 106 /// Callbacks - These are actions invoked when some preprocessor activity is 107 /// encountered (e.g. a file is #included, etc). 108 PPCallbacks *Callbacks; 109 110 // Various statistics we track for performance analysis. 111 unsigned NumDirectives, NumIncluded, NumDefined, NumUndefined, NumPragma; 112 unsigned NumIf, NumElse, NumEndif; 113 unsigned NumEnteredSourceFiles, MaxIncludeStackDepth; 114 unsigned NumMacroExpanded, NumFnMacroExpanded, NumBuiltinMacroExpanded; 115 unsigned NumFastMacroExpanded, NumTokenPaste, NumFastTokenPaste; 116 unsigned NumSkipped; 117 118 /// MacroExpanderCache - Cache macro expanders to reduce malloc traffic. 119 enum { MacroExpanderCacheSize = 8 }; 120 unsigned NumCachedMacroExpanders; 121 MacroExpander *MacroExpanderCache[MacroExpanderCacheSize]; 122public: 123 Preprocessor(Diagnostic &diags, const LangOptions &opts, TargetInfo &target, 124 SourceManager &SM, HeaderSearch &Headers); 125 ~Preprocessor(); 126 127 Diagnostic &getDiagnostics() const { return Diags; } 128 const LangOptions &getLangOptions() const { return Features; } 129 TargetInfo &getTargetInfo() const { return Target; } 130 FileManager &getFileManager() const { return FileMgr; } 131 SourceManager &getSourceManager() const { return SourceMgr; } 132 HeaderSearch &getHeaderSearchInfo() const { return HeaderInfo; } 133 134 IdentifierTable &getIdentifierTable() { return Identifiers; } 135 136 /// SetCommentRetentionState - Control whether or not the preprocessor retains 137 /// comments in output. 138 void SetCommentRetentionState(bool KeepComments, bool KeepMacroComments) { 139 this->KeepComments = KeepComments | KeepMacroComments; 140 this->KeepMacroComments = KeepMacroComments; 141 } 142 143 bool getCommentRetentionState() const { return KeepComments; } 144 145 /// isCurrentLexer - Return true if we are lexing directly from the specified 146 /// lexer. 147 bool isCurrentLexer(const Lexer *L) const { 148 return CurLexer == L; 149 } 150 151 /// isInPrimaryFile - Return true if we're in the top-level file, not in a 152 /// #include. 153 bool isInPrimaryFile() const; 154 155 /// getCurrentLexer - Return the current file lexer being lexed from. Note 156 /// that this ignores any potentially active macro expansions and _Pragma 157 /// expansions going on at the time. 158 Lexer *getCurrentFileLexer() const; 159 160 /// getPPCallbacks/SetPPCallbacks - Accessors for preprocessor callbacks. 161 /// 162 PPCallbacks *getPPCallbacks() const { return Callbacks; } 163 void setPPCallbacks(PPCallbacks *C) { 164 Callbacks = C; 165 } 166 167 /// getIdentifierInfo - Return information about the specified preprocessor 168 /// identifier token. The version of this method that takes two character 169 /// pointers is preferred unless the identifier is already available as a 170 /// string (this avoids allocation and copying of memory to construct an 171 /// std::string). 172 IdentifierInfo *getIdentifierInfo(const char *NameStart, 173 const char *NameEnd) { 174 return &Identifiers.get(NameStart, NameEnd); 175 } 176 IdentifierInfo *getIdentifierInfo(const char *NameStr) { 177 return getIdentifierInfo(NameStr, NameStr+strlen(NameStr)); 178 } 179 180 /// AddPragmaHandler - Add the specified pragma handler to the preprocessor. 181 /// If 'Namespace' is non-null, then it is a token required to exist on the 182 /// pragma line before the pragma string starts, e.g. "STDC" or "GCC". 183 void AddPragmaHandler(const char *Namespace, PragmaHandler *Handler); 184 185 /// EnterSourceFile - Add a source file to the top of the include stack and 186 /// start lexing tokens from it instead of the current buffer. If isMainFile 187 /// is true, this is the main file for the translation unit. 188 void EnterSourceFile(unsigned CurFileID, const DirectoryLookup *Dir, 189 bool isMainFile = false); 190 191 /// EnterMacro - Add a Macro to the top of the include stack and start lexing 192 /// tokens from it instead of the current buffer. Args specifies the 193 /// tokens input to a function-like macro. 194 void EnterMacro(Token &Identifier, MacroArgs *Args); 195 196 /// EnterTokenStream - Add a "macro" context to the top of the include stack, 197 /// which will cause the lexer to start returning the specified tokens. Note 198 /// that these tokens will be re-macro-expanded when/if expansion is enabled. 199 /// This method assumes that the specified stream of tokens has a permanent 200 /// owner somewhere, so they do not need to be copied. 201 void EnterTokenStream(const Token *Toks, unsigned NumToks); 202 203 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the 204 /// lexer stack. This should only be used in situations where the current 205 /// state of the top-of-stack lexer is known. 206 void RemoveTopOfLexerStack(); 207 208 /// Lex - To lex a token from the preprocessor, just pull a token from the 209 /// current lexer or macro object. 210 void Lex(Token &Result) { 211 if (CurLexer) 212 CurLexer->Lex(Result); 213 else 214 CurMacroExpander->Lex(Result); 215 } 216 217 /// LexNonComment - Lex a token. If it's a comment, keep lexing until we get 218 /// something not a comment. This is useful in -E -C mode where comments 219 /// would foul up preprocessor directive handling. 220 void LexNonComment(Token &Result) { 221 do 222 Lex(Result); 223 while (Result.getKind() == tok::comment); 224 } 225 226 /// LexUnexpandedToken - This is just like Lex, but this disables macro 227 /// expansion of identifier tokens. 228 void LexUnexpandedToken(Token &Result) { 229 // Disable macro expansion. 230 bool OldVal = DisableMacroExpansion; 231 DisableMacroExpansion = true; 232 // Lex the token. 233 Lex(Result); 234 235 // Reenable it. 236 DisableMacroExpansion = OldVal; 237 } 238 239 /// Diag - Forwarding function for diagnostics. This emits a diagnostic at 240 /// the specified Token's location, translating the token's start 241 /// position in the current buffer into a SourcePosition object for rendering. 242 void Diag(SourceLocation Loc, unsigned DiagID); 243 void Diag(SourceLocation Loc, unsigned DiagID, const std::string &Msg); 244 void Diag(const Token &Tok, unsigned DiagID) { 245 Diag(Tok.getLocation(), DiagID); 246 } 247 void Diag(const Token &Tok, unsigned DiagID, const std::string &Msg) { 248 Diag(Tok.getLocation(), DiagID, Msg); 249 } 250 251 /// getSpelling() - Return the 'spelling' of the Tok token. The spelling of a 252 /// token is the characters used to represent the token in the source file 253 /// after trigraph expansion and escaped-newline folding. In particular, this 254 /// wants to get the true, uncanonicalized, spelling of things like digraphs 255 /// UCNs, etc. 256 std::string getSpelling(const Token &Tok) const; 257 258 /// getSpelling - This method is used to get the spelling of a token into a 259 /// preallocated buffer, instead of as an std::string. The caller is required 260 /// to allocate enough space for the token, which is guaranteed to be at least 261 /// Tok.getLength() bytes long. The length of the actual result is returned. 262 /// 263 /// Note that this method may do two possible things: it may either fill in 264 /// the buffer specified with characters, or it may *change the input pointer* 265 /// to point to a constant buffer with the data already in it (avoiding a 266 /// copy). The caller is not allowed to modify the returned buffer pointer 267 /// if an internal buffer is returned. 268 unsigned getSpelling(const Token &Tok, const char *&Buffer) const; 269 270 271 /// CreateString - Plop the specified string into a scratch buffer and return 272 /// a location for it. If specified, the source location provides a source 273 /// location for the token. 274 SourceLocation CreateString(const char *Buf, unsigned Len, 275 SourceLocation SourceLoc = SourceLocation()); 276 277 /// DumpToken - Print the token to stderr, used for debugging. 278 /// 279 void DumpToken(const Token &Tok, bool DumpFlags = false) const; 280 void DumpMacro(const MacroInfo &MI) const; 281 282 /// AdvanceToTokenCharacter - Given a location that specifies the start of a 283 /// token, return a new location that specifies a character within the token. 284 SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart,unsigned Char); 285 286 /// IncrementPasteCounter - Increment the counters for the number of token 287 /// paste operations performed. If fast was specified, this is a 'fast paste' 288 /// case we handled. 289 /// 290 void IncrementPasteCounter(bool isFast) { 291 if (isFast) 292 ++NumFastTokenPaste; 293 else 294 ++NumTokenPaste; 295 } 296 297 void PrintStats(); 298 299 //===--------------------------------------------------------------------===// 300 // Preprocessor callback methods. These are invoked by a lexer as various 301 // directives and events are found. 302 303 /// LookUpIdentifierInfo - Given a tok::identifier token, look up the 304 /// identifier information for the token and install it into the token. 305 IdentifierInfo *LookUpIdentifierInfo(Token &Identifier, 306 const char *BufPtr = 0); 307 308 /// HandleIdentifier - This callback is invoked when the lexer reads an 309 /// identifier and has filled in the tokens IdentifierInfo member. This 310 /// callback potentially macro expands it or turns it into a named token (like 311 /// 'for'). 312 void HandleIdentifier(Token &Identifier); 313 314 315 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of 316 /// the current file. This either returns the EOF token and returns true, or 317 /// pops a level off the include stack and returns false, at which point the 318 /// client should call lex again. 319 bool HandleEndOfFile(Token &Result, bool isEndOfMacro = false); 320 321 /// HandleEndOfMacro - This callback is invoked when the lexer hits the end of 322 /// the current macro line. It returns true if Result is filled in with a 323 /// token, or false if Lex should be called again. 324 bool HandleEndOfMacro(Token &Result); 325 326 /// HandleDirective - This callback is invoked when the lexer sees a # token 327 /// at the start of a line. This consumes the directive, modifies the 328 /// lexer/preprocessor state, and advances the lexer(s) so that the next token 329 /// read is the correct one. 330 void HandleDirective(Token &Result); 331 332 /// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If 333 /// not, emit a diagnostic and consume up until the eom. 334 void CheckEndOfDirective(const char *Directive); 335private: 336 337 /// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the 338 /// current line until the tok::eom token is found. 339 void DiscardUntilEndOfDirective(); 340 341 /// ReadMacroName - Lex and validate a macro name, which occurs after a 342 /// #define or #undef. This emits a diagnostic, sets the token kind to eom, 343 /// and discards the rest of the macro line if the macro name is invalid. 344 void ReadMacroName(Token &MacroNameTok, char isDefineUndef = 0); 345 346 /// ReadMacroDefinitionArgList - The ( starting an argument list of a macro 347 /// definition has just been read. Lex the rest of the arguments and the 348 /// closing ), updating MI with what we learn. Return true if an error occurs 349 /// parsing the arg list. 350 bool ReadMacroDefinitionArgList(MacroInfo *MI); 351 352 /// SkipExcludedConditionalBlock - We just read a #if or related directive and 353 /// decided that the subsequent tokens are in the #if'd out portion of the 354 /// file. Lex the rest of the file, until we see an #endif. If 355 /// FoundNonSkipPortion is true, then we have already emitted code for part of 356 /// this #if directive, so #else/#elif blocks should never be entered. If 357 /// FoundElse is false, then #else directives are ok, if not, then we have 358 /// already seen one so a #else directive is a duplicate. When this returns, 359 /// the caller can lex the first valid token. 360 void SkipExcludedConditionalBlock(SourceLocation IfTokenLoc, 361 bool FoundNonSkipPortion, bool FoundElse); 362 363 /// EvaluateDirectiveExpression - Evaluate an integer constant expression that 364 /// may occur after a #if or #elif directive and return it as a bool. If the 365 /// expression is equivalent to "!defined(X)" return X in IfNDefMacro. 366 bool EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro); 367 368 /// RegisterBuiltinPragmas - Install the standard preprocessor pragmas: 369 /// #pragma GCC poison/system_header/dependency and #pragma once. 370 void RegisterBuiltinPragmas(); 371 372 /// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the 373 /// identifier table. 374 void RegisterBuiltinMacros(); 375 IdentifierInfo *RegisterBuiltinMacro(const char *Name); 376 377 /// HandleMacroExpandedIdentifier - If an identifier token is read that is to 378 /// be expanded as a macro, handle it and return the next token as 'Tok'. If 379 /// the macro should not be expanded return true, otherwise return false. 380 bool HandleMacroExpandedIdentifier(Token &Tok, MacroInfo *MI); 381 382 /// isNextPPTokenLParen - Determine whether the next preprocessor token to be 383 /// lexed is a '('. If so, consume the token and return true, if not, this 384 /// method should have no observable side-effect on the lexed tokens. 385 bool isNextPPTokenLParen(); 386 387 /// ReadFunctionLikeMacroArgs - After reading "MACRO(", this method is 388 /// invoked to read all of the formal arguments specified for the macro 389 /// invocation. This returns null on error. 390 MacroArgs *ReadFunctionLikeMacroArgs(Token &MacroName, MacroInfo *MI); 391 392 /// ExpandBuiltinMacro - If an identifier token is read that is to be expanded 393 /// as a builtin macro, handle it and return the next token as 'Tok'. 394 void ExpandBuiltinMacro(Token &Tok); 395 396 /// Handle_Pragma - Read a _Pragma directive, slice it up, process it, then 397 /// return the first token after the directive. The _Pragma token has just 398 /// been read into 'Tok'. 399 void Handle_Pragma(Token &Tok); 400 401 402 /// EnterSourceFileWithLexer - Add a lexer to the top of the include stack and 403 /// start lexing tokens from it instead of the current buffer. 404 void EnterSourceFileWithLexer(Lexer *TheLexer, const DirectoryLookup *Dir); 405 406 /// GetIncludeFilenameSpelling - Turn the specified lexer token into a fully 407 /// checked and spelled filename, e.g. as an operand of #include. This returns 408 /// true if the input filename was in <>'s or false if it were in ""'s. The 409 /// caller is expected to provide a buffer that is large enough to hold the 410 /// spelling of the filename, but is also expected to handle the case when 411 /// this method decides to use a different buffer. 412 bool GetIncludeFilenameSpelling(const Token &FNTok, 413 const char *&BufStart, const char *&BufEnd); 414 415 /// LookupFile - Given a "foo" or <foo> reference, look up the indicated file, 416 /// return null on failure. isAngled indicates whether the file reference is 417 /// for system #include's or not (i.e. using <> instead of ""). 418 const FileEntry *LookupFile(const char *FilenameStart,const char *FilenameEnd, 419 bool isAngled, const DirectoryLookup *FromDir, 420 const DirectoryLookup *&CurDir); 421 422 //===--------------------------------------------------------------------===// 423 /// Handle*Directive - implement the various preprocessor directives. These 424 /// should side-effect the current preprocessor object so that the next call 425 /// to Lex() will return the appropriate token next. 426 427 void HandleUserDiagnosticDirective(Token &Tok, bool isWarning); 428 void HandleIdentSCCSDirective(Token &Tok); 429 430 // File inclusion. 431 void HandleIncludeDirective(Token &Tok, 432 const DirectoryLookup *LookupFrom = 0, 433 bool isImport = false); 434 void HandleIncludeNextDirective(Token &Tok); 435 void HandleImportDirective(Token &Tok); 436 437 // Macro handling. 438 void HandleDefineDirective(Token &Tok, bool isTargetSpecific); 439 void HandleUndefDirective(Token &Tok); 440 void HandleDefineOtherTargetDirective(Token &Tok); 441 // HandleAssertDirective(Token &Tok); 442 // HandleUnassertDirective(Token &Tok); 443 444 // Conditional Inclusion. 445 void HandleIfdefDirective(Token &Tok, bool isIfndef, 446 bool ReadAnyTokensBeforeDirective); 447 void HandleIfDirective(Token &Tok, bool ReadAnyTokensBeforeDirective); 448 void HandleEndifDirective(Token &Tok); 449 void HandleElseDirective(Token &Tok); 450 void HandleElifDirective(Token &Tok); 451 452 // Pragmas. 453 void HandlePragmaDirective(); 454public: 455 void HandlePragmaOnce(Token &OnceTok); 456 void HandlePragmaPoison(Token &PoisonTok); 457 void HandlePragmaSystemHeader(Token &SysHeaderTok); 458 void HandlePragmaDependency(Token &DependencyTok); 459}; 460 461} // end namespace clang 462 463#endif 464