TokenLexer.cpp revision ec3b5389a5032433116ec2f2ee266b9666ad2eb4
1//===--- TokenLexer.cpp - Lex from a token stream -------------------------===// 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 TokenLexer interface. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Lex/TokenLexer.h" 15#include "MacroArgs.h" 16#include "clang/Lex/MacroInfo.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/Basic/SourceManager.h" 19#include "clang/Lex/LexDiagnostic.h" 20#include "llvm/ADT/SmallVector.h" 21using namespace clang; 22 23 24/// Create a TokenLexer for the specified macro with the specified actual 25/// arguments. Note that this ctor takes ownership of the ActualArgs pointer. 26void TokenLexer::Init(Token &Tok, SourceLocation ELEnd, MacroArgs *Actuals) { 27 // If the client is reusing a TokenLexer, make sure to free any memory 28 // associated with it. 29 destroy(); 30 31 Macro = PP.getMacroInfo(Tok.getIdentifierInfo()); 32 ActualArgs = Actuals; 33 CurToken = 0; 34 35 ExpandLocStart = Tok.getLocation(); 36 ExpandLocEnd = ELEnd; 37 AtStartOfLine = Tok.isAtStartOfLine(); 38 HasLeadingSpace = Tok.hasLeadingSpace(); 39 Tokens = &*Macro->tokens_begin(); 40 OwnsTokens = false; 41 DisableMacroExpansion = false; 42 NumTokens = Macro->tokens_end()-Macro->tokens_begin(); 43 MacroExpansionStart = SourceLocation(); 44 45 SourceManager &SM = PP.getSourceManager(); 46 MacroStartSLocOffset = SM.getNextLocalOffset(); 47 48 if (NumTokens > 0) { 49 assert(Tokens[0].getLocation().isValid()); 50 assert((Tokens[0].getLocation().isFileID() || Tokens[0].is(tok::comment)) && 51 "Macro defined in macro?"); 52 assert(ExpandLocStart.isValid()); 53 54 // Reserve a source location entry chunk for the length of the macro 55 // definition. Tokens that get lexed directly from the definition will 56 // have their locations pointing inside this chunk. This is to avoid 57 // creating separate source location entries for each token. 58 SourceLocation macroStart = SM.getExpansionLoc(Tokens[0].getLocation()); 59 MacroDefStartInfo = SM.getDecomposedLoc(macroStart); 60 MacroExpansionStart = SM.createExpansionLoc(macroStart, 61 ExpandLocStart, 62 ExpandLocEnd, 63 Macro->getDefinitionLength(SM)); 64 } 65 66 // If this is a function-like macro, expand the arguments and change 67 // Tokens to point to the expanded tokens. 68 if (Macro->isFunctionLike() && Macro->getNumArgs()) 69 ExpandFunctionArguments(); 70 71 // Mark the macro as currently disabled, so that it is not recursively 72 // expanded. The macro must be disabled only after argument pre-expansion of 73 // function-like macro arguments occurs. 74 Macro->DisableMacro(); 75} 76 77 78 79/// Create a TokenLexer for the specified token stream. This does not 80/// take ownership of the specified token vector. 81void TokenLexer::Init(const Token *TokArray, unsigned NumToks, 82 bool disableMacroExpansion, bool ownsTokens) { 83 // If the client is reusing a TokenLexer, make sure to free any memory 84 // associated with it. 85 destroy(); 86 87 Macro = 0; 88 ActualArgs = 0; 89 Tokens = TokArray; 90 OwnsTokens = ownsTokens; 91 DisableMacroExpansion = disableMacroExpansion; 92 NumTokens = NumToks; 93 CurToken = 0; 94 ExpandLocStart = ExpandLocEnd = SourceLocation(); 95 AtStartOfLine = false; 96 HasLeadingSpace = false; 97 MacroExpansionStart = SourceLocation(); 98 99 // Set HasLeadingSpace/AtStartOfLine so that the first token will be 100 // returned unmodified. 101 if (NumToks != 0) { 102 AtStartOfLine = TokArray[0].isAtStartOfLine(); 103 HasLeadingSpace = TokArray[0].hasLeadingSpace(); 104 } 105} 106 107 108void TokenLexer::destroy() { 109 // If this was a function-like macro that actually uses its arguments, delete 110 // the expanded tokens. 111 if (OwnsTokens) { 112 delete [] Tokens; 113 Tokens = 0; 114 OwnsTokens = false; 115 } 116 117 // TokenLexer owns its formal arguments. 118 if (ActualArgs) ActualArgs->destroy(PP); 119} 120 121/// Expand the arguments of a function-like macro so that we can quickly 122/// return preexpanded tokens from Tokens. 123void TokenLexer::ExpandFunctionArguments() { 124 SourceManager &SM = PP.getSourceManager(); 125 126 SmallVector<Token, 128> ResultToks; 127 128 // Loop through 'Tokens', expanding them into ResultToks. Keep 129 // track of whether we change anything. If not, no need to keep them. If so, 130 // we install the newly expanded sequence as the new 'Tokens' list. 131 bool MadeChange = false; 132 133 // NextTokGetsSpace - When this is true, the next token appended to the 134 // output list will get a leading space, regardless of whether it had one to 135 // begin with or not. This is used for placemarker support. 136 bool NextTokGetsSpace = false; 137 138 for (unsigned i = 0, e = NumTokens; i != e; ++i) { 139 // If we found the stringify operator, get the argument stringified. The 140 // preprocessor already verified that the following token is a macro name 141 // when the #define was parsed. 142 const Token &CurTok = Tokens[i]; 143 if (CurTok.is(tok::hash) || CurTok.is(tok::hashat)) { 144 int ArgNo = Macro->getArgumentNum(Tokens[i+1].getIdentifierInfo()); 145 assert(ArgNo != -1 && "Token following # is not an argument?"); 146 147 SourceLocation hashInstLoc; 148 if(ExpandLocStart.isValid()) { 149 hashInstLoc = getExpansionLocForMacroDefLoc(CurTok.getLocation()); 150 assert(hashInstLoc.isValid() && "Expected '#' to come from definition"); 151 } 152 153 Token Res; 154 if (CurTok.is(tok::hash)) // Stringify 155 Res = ActualArgs->getStringifiedArgument(ArgNo, PP, hashInstLoc); 156 else { 157 // 'charify': don't bother caching these. 158 Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo), 159 PP, true, hashInstLoc); 160 } 161 162 // The stringified/charified string leading space flag gets set to match 163 // the #/#@ operator. 164 if (CurTok.hasLeadingSpace() || NextTokGetsSpace) 165 Res.setFlag(Token::LeadingSpace); 166 167 ResultToks.push_back(Res); 168 MadeChange = true; 169 ++i; // Skip arg name. 170 NextTokGetsSpace = false; 171 continue; 172 } 173 174 // Otherwise, if this is not an argument token, just add the token to the 175 // output buffer. 176 IdentifierInfo *II = CurTok.getIdentifierInfo(); 177 int ArgNo = II ? Macro->getArgumentNum(II) : -1; 178 if (ArgNo == -1) { 179 // This isn't an argument, just add it. 180 ResultToks.push_back(CurTok); 181 182 if (NextTokGetsSpace) { 183 ResultToks.back().setFlag(Token::LeadingSpace); 184 NextTokGetsSpace = false; 185 } 186 continue; 187 } 188 189 // An argument is expanded somehow, the result is different than the 190 // input. 191 MadeChange = true; 192 193 // Otherwise, this is a use of the argument. Find out if there is a paste 194 // (##) operator before or after the argument. 195 bool PasteBefore = 196 !ResultToks.empty() && ResultToks.back().is(tok::hashhash); 197 bool PasteAfter = i+1 != e && Tokens[i+1].is(tok::hashhash); 198 199 // If it is not the LHS/RHS of a ## operator, we must pre-expand the 200 // argument and substitute the expanded tokens into the result. This is 201 // C99 6.10.3.1p1. 202 if (!PasteBefore && !PasteAfter) { 203 const Token *ResultArgToks; 204 205 // Only preexpand the argument if it could possibly need it. This 206 // avoids some work in common cases. 207 const Token *ArgTok = ActualArgs->getUnexpArgument(ArgNo); 208 if (ActualArgs->ArgNeedsPreexpansion(ArgTok, PP)) 209 ResultArgToks = &ActualArgs->getPreExpArgument(ArgNo, Macro, PP)[0]; 210 else 211 ResultArgToks = ArgTok; // Use non-preexpanded tokens. 212 213 // If the arg token expanded into anything, append it. 214 if (ResultArgToks->isNot(tok::eof)) { 215 unsigned FirstResult = ResultToks.size(); 216 unsigned NumToks = MacroArgs::getArgLength(ResultArgToks); 217 ResultToks.append(ResultArgToks, ResultArgToks+NumToks); 218 219 // If the '##' came from expanding an argument, turn it into 'unknown' 220 // to avoid pasting. 221 for (unsigned i = FirstResult, e = ResultToks.size(); i != e; ++i) { 222 Token &Tok = ResultToks[i]; 223 if (Tok.is(tok::hashhash)) 224 Tok.setKind(tok::unknown); 225 } 226 227 if(ExpandLocStart.isValid()) { 228 SourceLocation curInst = 229 getExpansionLocForMacroDefLoc(CurTok.getLocation()); 230 assert(curInst.isValid() && 231 "Expected arg identifier to come from definition"); 232 for (unsigned i = FirstResult, e = ResultToks.size(); i != e; ++i) { 233 Token &Tok = ResultToks[i]; 234 Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(), 235 curInst, 236 Tok.getLength())); 237 } 238 } 239 240 // If any tokens were substituted from the argument, the whitespace 241 // before the first token should match the whitespace of the arg 242 // identifier. 243 ResultToks[FirstResult].setFlagValue(Token::LeadingSpace, 244 CurTok.hasLeadingSpace() || 245 NextTokGetsSpace); 246 NextTokGetsSpace = false; 247 } else { 248 // If this is an empty argument, and if there was whitespace before the 249 // formal token, make sure the next token gets whitespace before it. 250 NextTokGetsSpace = CurTok.hasLeadingSpace(); 251 } 252 continue; 253 } 254 255 // Okay, we have a token that is either the LHS or RHS of a paste (##) 256 // argument. It gets substituted as its non-pre-expanded tokens. 257 const Token *ArgToks = ActualArgs->getUnexpArgument(ArgNo); 258 unsigned NumToks = MacroArgs::getArgLength(ArgToks); 259 if (NumToks) { // Not an empty argument? 260 // If this is the GNU ", ## __VA_ARG__" extension, and we just learned 261 // that __VA_ARG__ expands to multiple tokens, avoid a pasting error when 262 // the expander trys to paste ',' with the first token of the __VA_ARG__ 263 // expansion. 264 if (PasteBefore && ResultToks.size() >= 2 && 265 ResultToks[ResultToks.size()-2].is(tok::comma) && 266 (unsigned)ArgNo == Macro->getNumArgs()-1 && 267 Macro->isVariadic()) { 268 // Remove the paste operator, report use of the extension. 269 PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma); 270 ResultToks.pop_back(); 271 } 272 273 ResultToks.append(ArgToks, ArgToks+NumToks); 274 275 // If the '##' came from expanding an argument, turn it into 'unknown' 276 // to avoid pasting. 277 for (unsigned i = ResultToks.size() - NumToks, e = ResultToks.size(); 278 i != e; ++i) { 279 Token &Tok = ResultToks[i]; 280 if (Tok.is(tok::hashhash)) 281 Tok.setKind(tok::unknown); 282 } 283 284 if (ExpandLocStart.isValid()) { 285 SourceLocation curInst = 286 getExpansionLocForMacroDefLoc(CurTok.getLocation()); 287 assert(curInst.isValid() && 288 "Expected arg identifier to come from definition"); 289 for (unsigned i = ResultToks.size() - NumToks, e = ResultToks.size(); 290 i != e; ++i) { 291 Token &Tok = ResultToks[i]; 292 Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(), 293 curInst, 294 Tok.getLength())); 295 } 296 } 297 298 // If this token (the macro argument) was supposed to get leading 299 // whitespace, transfer this information onto the first token of the 300 // expansion. 301 // 302 // Do not do this if the paste operator occurs before the macro argument, 303 // as in "A ## MACROARG". In valid code, the first token will get 304 // smooshed onto the preceding one anyway (forming AMACROARG). In 305 // assembler-with-cpp mode, invalid pastes are allowed through: in this 306 // case, we do not want the extra whitespace to be added. For example, 307 // we want ". ## foo" -> ".foo" not ". foo". 308 if ((CurTok.hasLeadingSpace() || NextTokGetsSpace) && 309 !PasteBefore) 310 ResultToks[ResultToks.size()-NumToks].setFlag(Token::LeadingSpace); 311 312 NextTokGetsSpace = false; 313 continue; 314 } 315 316 // If an empty argument is on the LHS or RHS of a paste, the standard (C99 317 // 6.10.3.3p2,3) calls for a bunch of placemarker stuff to occur. We 318 // implement this by eating ## operators when a LHS or RHS expands to 319 // empty. 320 NextTokGetsSpace |= CurTok.hasLeadingSpace(); 321 if (PasteAfter) { 322 // Discard the argument token and skip (don't copy to the expansion 323 // buffer) the paste operator after it. 324 NextTokGetsSpace |= Tokens[i+1].hasLeadingSpace(); 325 ++i; 326 continue; 327 } 328 329 // If this is on the RHS of a paste operator, we've already copied the 330 // paste operator to the ResultToks list. Remove it. 331 assert(PasteBefore && ResultToks.back().is(tok::hashhash)); 332 NextTokGetsSpace |= ResultToks.back().hasLeadingSpace(); 333 ResultToks.pop_back(); 334 335 // If this is the __VA_ARGS__ token, and if the argument wasn't provided, 336 // and if the macro had at least one real argument, and if the token before 337 // the ## was a comma, remove the comma. 338 if ((unsigned)ArgNo == Macro->getNumArgs()-1 && // is __VA_ARGS__ 339 ActualArgs->isVarargsElidedUse() && // Argument elided. 340 !ResultToks.empty() && ResultToks.back().is(tok::comma)) { 341 // Never add a space, even if the comma, ##, or arg had a space. 342 NextTokGetsSpace = false; 343 // Remove the paste operator, report use of the extension. 344 PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma); 345 ResultToks.pop_back(); 346 347 // If the comma was right after another paste (e.g. "X##,##__VA_ARGS__"), 348 // then removal of the comma should produce a placemarker token (in C99 349 // terms) which we model by popping off the previous ##, giving us a plain 350 // "X" when __VA_ARGS__ is empty. 351 if (!ResultToks.empty() && ResultToks.back().is(tok::hashhash)) 352 ResultToks.pop_back(); 353 } 354 continue; 355 } 356 357 // If anything changed, install this as the new Tokens list. 358 if (MadeChange) { 359 assert(!OwnsTokens && "This would leak if we already own the token list"); 360 // This is deleted in the dtor. 361 NumTokens = ResultToks.size(); 362 // The tokens will be added to Preprocessor's cache and will be removed 363 // when this TokenLexer finishes lexing them. 364 Tokens = PP.cacheMacroExpandedTokens(this, ResultToks); 365 366 // The preprocessor cache of macro expanded tokens owns these tokens,not us. 367 OwnsTokens = false; 368 } 369} 370 371/// Lex - Lex and return a token from this macro stream. 372/// 373void TokenLexer::Lex(Token &Tok) { 374 // Lexing off the end of the macro, pop this macro off the expansion stack. 375 if (isAtEnd()) { 376 // If this is a macro (not a token stream), mark the macro enabled now 377 // that it is no longer being expanded. 378 if (Macro) Macro->EnableMacro(); 379 380 // Pop this context off the preprocessors lexer stack and get the next 381 // token. This will delete "this" so remember the PP instance var. 382 Preprocessor &PPCache = PP; 383 if (PP.HandleEndOfTokenLexer(Tok)) 384 return; 385 386 // HandleEndOfTokenLexer may not return a token. If it doesn't, lex 387 // whatever is next. 388 return PPCache.Lex(Tok); 389 } 390 391 SourceManager &SM = PP.getSourceManager(); 392 393 // If this is the first token of the expanded result, we inherit spacing 394 // properties later. 395 bool isFirstToken = CurToken == 0; 396 397 // Get the next token to return. 398 Tok = Tokens[CurToken++]; 399 400 bool TokenIsFromPaste = false; 401 402 // If this token is followed by a token paste (##) operator, paste the tokens! 403 // Note that ## is a normal token when not expanding a macro. 404 if (!isAtEnd() && Tokens[CurToken].is(tok::hashhash) && Macro) { 405 // When handling the microsoft /##/ extension, the final token is 406 // returned by PasteTokens, not the pasted token. 407 if (PasteTokens(Tok)) 408 return; 409 410 TokenIsFromPaste = true; 411 } 412 413 // The token's current location indicate where the token was lexed from. We 414 // need this information to compute the spelling of the token, but any 415 // diagnostics for the expanded token should appear as if they came from 416 // ExpansionLoc. Pull this information together into a new SourceLocation 417 // that captures all of this. 418 if (ExpandLocStart.isValid() && // Don't do this for token streams. 419 // Check that the token's location was not already set properly. 420 SM.isBeforeInSourceLocationOffset(Tok.getLocation(), 421 MacroStartSLocOffset)) { 422 SourceLocation instLoc; 423 if (Tok.is(tok::comment)) { 424 instLoc = SM.createExpansionLoc(Tok.getLocation(), 425 ExpandLocStart, 426 ExpandLocEnd, 427 Tok.getLength()); 428 } else { 429 instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation()); 430 assert(instLoc.isValid() && 431 "Location for token not coming from definition was not set!"); 432 } 433 434 Tok.setLocation(instLoc); 435 } 436 437 // If this is the first token, set the lexical properties of the token to 438 // match the lexical properties of the macro identifier. 439 if (isFirstToken) { 440 Tok.setFlagValue(Token::StartOfLine , AtStartOfLine); 441 Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace); 442 } 443 444 // Handle recursive expansion! 445 if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != 0) { 446 // Change the kind of this identifier to the appropriate token kind, e.g. 447 // turning "for" into a keyword. 448 IdentifierInfo *II = Tok.getIdentifierInfo(); 449 Tok.setKind(II->getTokenID()); 450 451 // If this identifier was poisoned and from a paste, emit an error. This 452 // won't be handled by Preprocessor::HandleIdentifier because this is coming 453 // from a macro expansion. 454 if (II->isPoisoned() && TokenIsFromPaste) { 455 PP.HandlePoisonedIdentifier(Tok); 456 } 457 458 if (!DisableMacroExpansion && II->isHandleIdentifierCase()) 459 PP.HandleIdentifier(Tok); 460 } 461 462 // Otherwise, return a normal token. 463} 464 465/// PasteTokens - Tok is the LHS of a ## operator, and CurToken is the ## 466/// operator. Read the ## and RHS, and paste the LHS/RHS together. If there 467/// are more ## after it, chomp them iteratively. Return the result as Tok. 468/// If this returns true, the caller should immediately return the token. 469bool TokenLexer::PasteTokens(Token &Tok) { 470 llvm::SmallString<128> Buffer; 471 const char *ResultTokStrPtr = 0; 472 SourceLocation PasteOpLoc; 473 do { 474 // Consume the ## operator. 475 PasteOpLoc = Tokens[CurToken].getLocation(); 476 ++CurToken; 477 assert(!isAtEnd() && "No token on the RHS of a paste operator!"); 478 479 // Get the RHS token. 480 const Token &RHS = Tokens[CurToken]; 481 482 // Allocate space for the result token. This is guaranteed to be enough for 483 // the two tokens. 484 Buffer.resize(Tok.getLength() + RHS.getLength()); 485 486 // Get the spelling of the LHS token in Buffer. 487 const char *BufPtr = &Buffer[0]; 488 bool Invalid = false; 489 unsigned LHSLen = PP.getSpelling(Tok, BufPtr, &Invalid); 490 if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer! 491 memcpy(&Buffer[0], BufPtr, LHSLen); 492 if (Invalid) 493 return true; 494 495 BufPtr = &Buffer[LHSLen]; 496 unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid); 497 if (Invalid) 498 return true; 499 if (BufPtr != &Buffer[LHSLen]) // Really, we want the chars in Buffer! 500 memcpy(&Buffer[LHSLen], BufPtr, RHSLen); 501 502 // Trim excess space. 503 Buffer.resize(LHSLen+RHSLen); 504 505 // Plop the pasted result (including the trailing newline and null) into a 506 // scratch buffer where we can lex it. 507 Token ResultTokTmp; 508 ResultTokTmp.startToken(); 509 510 // Claim that the tmp token is a string_literal so that we can get the 511 // character pointer back from CreateString in getLiteralData(). 512 ResultTokTmp.setKind(tok::string_literal); 513 PP.CreateString(&Buffer[0], Buffer.size(), ResultTokTmp); 514 SourceLocation ResultTokLoc = ResultTokTmp.getLocation(); 515 ResultTokStrPtr = ResultTokTmp.getLiteralData(); 516 517 // Lex the resultant pasted token into Result. 518 Token Result; 519 520 if (Tok.isAnyIdentifier() && RHS.isAnyIdentifier()) { 521 // Common paste case: identifier+identifier = identifier. Avoid creating 522 // a lexer and other overhead. 523 PP.IncrementPasteCounter(true); 524 Result.startToken(); 525 Result.setKind(tok::raw_identifier); 526 Result.setRawIdentifierData(ResultTokStrPtr); 527 Result.setLocation(ResultTokLoc); 528 Result.setLength(LHSLen+RHSLen); 529 } else { 530 PP.IncrementPasteCounter(false); 531 532 assert(ResultTokLoc.isFileID() && 533 "Should be a raw location into scratch buffer"); 534 SourceManager &SourceMgr = PP.getSourceManager(); 535 FileID LocFileID = SourceMgr.getFileID(ResultTokLoc); 536 537 bool Invalid = false; 538 const char *ScratchBufStart 539 = SourceMgr.getBufferData(LocFileID, &Invalid).data(); 540 if (Invalid) 541 return false; 542 543 // Make a lexer to lex this string from. Lex just this one token. 544 // Make a lexer object so that we lex and expand the paste result. 545 Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID), 546 PP.getLangOptions(), ScratchBufStart, 547 ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen); 548 549 // Lex a token in raw mode. This way it won't look up identifiers 550 // automatically, lexing off the end will return an eof token, and 551 // warnings are disabled. This returns true if the result token is the 552 // entire buffer. 553 bool isInvalid = !TL.LexFromRawLexer(Result); 554 555 // If we got an EOF token, we didn't form even ONE token. For example, we 556 // did "/ ## /" to get "//". 557 isInvalid |= Result.is(tok::eof); 558 559 // If pasting the two tokens didn't form a full new token, this is an 560 // error. This occurs with "x ## +" and other stuff. Return with Tok 561 // unmodified and with RHS as the next token to lex. 562 if (isInvalid) { 563 // Test for the Microsoft extension of /##/ turning into // here on the 564 // error path. 565 if (PP.getLangOptions().Microsoft && Tok.is(tok::slash) && 566 RHS.is(tok::slash)) { 567 HandleMicrosoftCommentPaste(Tok); 568 return true; 569 } 570 571 // Do not emit the error when preprocessing assembler code. 572 if (!PP.getLangOptions().AsmPreprocessor) { 573 // Explicitly convert the token location to have proper expansion 574 // information so that the user knows where it came from. 575 SourceManager &SM = PP.getSourceManager(); 576 SourceLocation Loc = 577 SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2); 578 // If we're in microsoft extensions mode, downgrade this from a hard 579 // error to a warning that defaults to an error. This allows 580 // disabling it. 581 PP.Diag(Loc, 582 PP.getLangOptions().Microsoft ? diag::err_pp_bad_paste_ms 583 : diag::err_pp_bad_paste) 584 << Buffer.str(); 585 } 586 587 // Do not consume the RHS. 588 --CurToken; 589 } 590 591 // Turn ## into 'unknown' to avoid # ## # from looking like a paste 592 // operator. 593 if (Result.is(tok::hashhash)) 594 Result.setKind(tok::unknown); 595 } 596 597 // Transfer properties of the LHS over the the Result. 598 Result.setFlagValue(Token::StartOfLine , Tok.isAtStartOfLine()); 599 Result.setFlagValue(Token::LeadingSpace, Tok.hasLeadingSpace()); 600 601 // Finally, replace LHS with the result, consume the RHS, and iterate. 602 ++CurToken; 603 Tok = Result; 604 } while (!isAtEnd() && Tokens[CurToken].is(tok::hashhash)); 605 606 // The token's current location indicate where the token was lexed from. We 607 // need this information to compute the spelling of the token, but any 608 // diagnostics for the expanded token should appear as if the token was 609 // expanded from the (##) operator. Pull this information together into 610 // a new SourceLocation that captures all of this. 611 if (ExpandLocStart.isValid()) { 612 SourceManager &SM = PP.getSourceManager(); 613 SourceLocation pasteLocInst = 614 getExpansionLocForMacroDefLoc(PasteOpLoc); 615 assert(pasteLocInst.isValid() && 616 "Expected '##' to come from definition"); 617 618 Tok.setLocation(SM.createExpansionLoc(Tok.getLocation(), 619 pasteLocInst, 620 pasteLocInst, 621 Tok.getLength())); 622 } 623 624 // Now that we got the result token, it will be subject to expansion. Since 625 // token pasting re-lexes the result token in raw mode, identifier information 626 // isn't looked up. As such, if the result is an identifier, look up id info. 627 if (Tok.is(tok::raw_identifier)) { 628 // Look up the identifier info for the token. We disabled identifier lookup 629 // by saying we're skipping contents, so we need to do this manually. 630 PP.LookUpIdentifierInfo(Tok); 631 } 632 return false; 633} 634 635/// isNextTokenLParen - If the next token lexed will pop this macro off the 636/// expansion stack, return 2. If the next unexpanded token is a '(', return 637/// 1, otherwise return 0. 638unsigned TokenLexer::isNextTokenLParen() const { 639 // Out of tokens? 640 if (isAtEnd()) 641 return 2; 642 return Tokens[CurToken].is(tok::l_paren); 643} 644 645/// isParsingPreprocessorDirective - Return true if we are in the middle of a 646/// preprocessor directive. 647bool TokenLexer::isParsingPreprocessorDirective() const { 648 return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd(); 649} 650 651/// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes 652/// together to form a comment that comments out everything in the current 653/// macro, other active macros, and anything left on the current physical 654/// source line of the expanded buffer. Handle this by returning the 655/// first token on the next line. 656void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok) { 657 // We 'comment out' the rest of this macro by just ignoring the rest of the 658 // tokens that have not been lexed yet, if any. 659 660 // Since this must be a macro, mark the macro enabled now that it is no longer 661 // being expanded. 662 assert(Macro && "Token streams can't paste comments"); 663 Macro->EnableMacro(); 664 665 PP.HandleMicrosoftCommentPaste(Tok); 666} 667 668/// \brief If \arg loc is a file ID and points inside the current macro 669/// definition, returns the appropriate source location pointing at the 670/// macro expansion source location entry, otherwise it returns an invalid 671/// SourceLocation. 672SourceLocation 673TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const { 674 assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() && 675 "Not appropriate for token streams"); 676 assert(loc.isValid()); 677 678 SourceManager &SM = PP.getSourceManager(); 679 unsigned relativeOffset; 680 if (loc.isFileID() && 681 SM.isInFileID(loc, 682 MacroDefStartInfo.first, MacroDefStartInfo.second, 683 Macro->getDefinitionLength(SM), &relativeOffset)) { 684 return MacroExpansionStart.getFileLocWithOffset(relativeOffset); 685 } 686 687 return SourceLocation(); 688} 689