TokenLexer.cpp revision 327952
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 "clang/Basic/Diagnostic.h" 16#include "clang/Basic/IdentifierTable.h" 17#include "clang/Basic/LangOptions.h" 18#include "clang/Basic/SourceLocation.h" 19#include "clang/Basic/SourceManager.h" 20#include "clang/Basic/TokenKinds.h" 21#include "clang/Lex/LexDiagnostic.h" 22#include "clang/Lex/Lexer.h" 23#include "clang/Lex/MacroArgs.h" 24#include "clang/Lex/MacroInfo.h" 25#include "clang/Lex/Preprocessor.h" 26#include "clang/Lex/Token.h" 27#include "clang/Lex/VariadicMacroSupport.h" 28#include "llvm/ADT/ArrayRef.h" 29#include "llvm/ADT/SmallString.h" 30#include "llvm/ADT/SmallVector.h" 31#include "llvm/ADT/iterator_range.h" 32#include <cassert> 33#include <cstring> 34 35using namespace clang; 36 37/// Create a TokenLexer for the specified macro with the specified actual 38/// arguments. Note that this ctor takes ownership of the ActualArgs pointer. 39void TokenLexer::Init(Token &Tok, SourceLocation ELEnd, MacroInfo *MI, 40 MacroArgs *Actuals) { 41 // If the client is reusing a TokenLexer, make sure to free any memory 42 // associated with it. 43 destroy(); 44 45 Macro = MI; 46 ActualArgs = Actuals; 47 CurTokenIdx = 0; 48 49 ExpandLocStart = Tok.getLocation(); 50 ExpandLocEnd = ELEnd; 51 AtStartOfLine = Tok.isAtStartOfLine(); 52 HasLeadingSpace = Tok.hasLeadingSpace(); 53 NextTokGetsSpace = false; 54 Tokens = &*Macro->tokens_begin(); 55 OwnsTokens = false; 56 DisableMacroExpansion = false; 57 NumTokens = Macro->tokens_end()-Macro->tokens_begin(); 58 MacroExpansionStart = SourceLocation(); 59 60 SourceManager &SM = PP.getSourceManager(); 61 MacroStartSLocOffset = SM.getNextLocalOffset(); 62 63 if (NumTokens > 0) { 64 assert(Tokens[0].getLocation().isValid()); 65 assert((Tokens[0].getLocation().isFileID() || Tokens[0].is(tok::comment)) && 66 "Macro defined in macro?"); 67 assert(ExpandLocStart.isValid()); 68 69 // Reserve a source location entry chunk for the length of the macro 70 // definition. Tokens that get lexed directly from the definition will 71 // have their locations pointing inside this chunk. This is to avoid 72 // creating separate source location entries for each token. 73 MacroDefStart = SM.getExpansionLoc(Tokens[0].getLocation()); 74 MacroDefLength = Macro->getDefinitionLength(SM); 75 MacroExpansionStart = SM.createExpansionLoc(MacroDefStart, 76 ExpandLocStart, 77 ExpandLocEnd, 78 MacroDefLength); 79 } 80 81 // If this is a function-like macro, expand the arguments and change 82 // Tokens to point to the expanded tokens. 83 if (Macro->isFunctionLike() && Macro->getNumParams()) 84 ExpandFunctionArguments(); 85 86 // Mark the macro as currently disabled, so that it is not recursively 87 // expanded. The macro must be disabled only after argument pre-expansion of 88 // function-like macro arguments occurs. 89 Macro->DisableMacro(); 90} 91 92/// Create a TokenLexer for the specified token stream. This does not 93/// take ownership of the specified token vector. 94void TokenLexer::Init(const Token *TokArray, unsigned NumToks, 95 bool disableMacroExpansion, bool ownsTokens) { 96 // If the client is reusing a TokenLexer, make sure to free any memory 97 // associated with it. 98 destroy(); 99 100 Macro = nullptr; 101 ActualArgs = nullptr; 102 Tokens = TokArray; 103 OwnsTokens = ownsTokens; 104 DisableMacroExpansion = disableMacroExpansion; 105 NumTokens = NumToks; 106 CurTokenIdx = 0; 107 ExpandLocStart = ExpandLocEnd = SourceLocation(); 108 AtStartOfLine = false; 109 HasLeadingSpace = false; 110 NextTokGetsSpace = false; 111 MacroExpansionStart = SourceLocation(); 112 113 // Set HasLeadingSpace/AtStartOfLine so that the first token will be 114 // returned unmodified. 115 if (NumToks != 0) { 116 AtStartOfLine = TokArray[0].isAtStartOfLine(); 117 HasLeadingSpace = TokArray[0].hasLeadingSpace(); 118 } 119} 120 121void TokenLexer::destroy() { 122 // If this was a function-like macro that actually uses its arguments, delete 123 // the expanded tokens. 124 if (OwnsTokens) { 125 delete [] Tokens; 126 Tokens = nullptr; 127 OwnsTokens = false; 128 } 129 130 // TokenLexer owns its formal arguments. 131 if (ActualArgs) ActualArgs->destroy(PP); 132} 133 134bool TokenLexer::MaybeRemoveCommaBeforeVaArgs( 135 SmallVectorImpl<Token> &ResultToks, bool HasPasteOperator, MacroInfo *Macro, 136 unsigned MacroArgNo, Preprocessor &PP) { 137 // Is the macro argument __VA_ARGS__? 138 if (!Macro->isVariadic() || MacroArgNo != Macro->getNumParams()-1) 139 return false; 140 141 // In Microsoft-compatibility mode, a comma is removed in the expansion 142 // of " ... , __VA_ARGS__ " if __VA_ARGS__ is empty. This extension is 143 // not supported by gcc. 144 if (!HasPasteOperator && !PP.getLangOpts().MSVCCompat) 145 return false; 146 147 // GCC removes the comma in the expansion of " ... , ## __VA_ARGS__ " if 148 // __VA_ARGS__ is empty, but not in strict C99 mode where there are no 149 // named arguments, where it remains. In all other modes, including C99 150 // with GNU extensions, it is removed regardless of named arguments. 151 // Microsoft also appears to support this extension, unofficially. 152 if (PP.getLangOpts().C99 && !PP.getLangOpts().GNUMode 153 && Macro->getNumParams() < 2) 154 return false; 155 156 // Is a comma available to be removed? 157 if (ResultToks.empty() || !ResultToks.back().is(tok::comma)) 158 return false; 159 160 // Issue an extension diagnostic for the paste operator. 161 if (HasPasteOperator) 162 PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma); 163 164 // Remove the comma. 165 ResultToks.pop_back(); 166 167 if (!ResultToks.empty()) { 168 // If the comma was right after another paste (e.g. "X##,##__VA_ARGS__"), 169 // then removal of the comma should produce a placemarker token (in C99 170 // terms) which we model by popping off the previous ##, giving us a plain 171 // "X" when __VA_ARGS__ is empty. 172 if (ResultToks.back().is(tok::hashhash)) 173 ResultToks.pop_back(); 174 175 // Remember that this comma was elided. 176 ResultToks.back().setFlag(Token::CommaAfterElided); 177 } 178 179 // Never add a space, even if the comma, ##, or arg had a space. 180 NextTokGetsSpace = false; 181 return true; 182} 183 184void TokenLexer::stringifyVAOPTContents( 185 SmallVectorImpl<Token> &ResultToks, const VAOptExpansionContext &VCtx, 186 const SourceLocation VAOPTClosingParenLoc) { 187 const int NumToksPriorToVAOpt = VCtx.getNumberOfTokensPriorToVAOpt(); 188 const unsigned int NumVAOptTokens = ResultToks.size() - NumToksPriorToVAOpt; 189 Token *const VAOPTTokens = 190 NumVAOptTokens ? &ResultToks[NumToksPriorToVAOpt] : nullptr; 191 192 SmallVector<Token, 64> ConcatenatedVAOPTResultToks; 193 // FIXME: Should we keep track within VCtx that we did or didnot 194 // encounter pasting - and only then perform this loop. 195 196 // Perform token pasting (concatenation) prior to stringization. 197 for (unsigned int CurTokenIdx = 0; CurTokenIdx != NumVAOptTokens; 198 ++CurTokenIdx) { 199 if (VAOPTTokens[CurTokenIdx].is(tok::hashhash)) { 200 assert(CurTokenIdx != 0 && 201 "Can not have __VAOPT__ contents begin with a ##"); 202 Token &LHS = VAOPTTokens[CurTokenIdx - 1]; 203 pasteTokens(LHS, llvm::makeArrayRef(VAOPTTokens, NumVAOptTokens), 204 CurTokenIdx); 205 // Replace the token prior to the first ## in this iteration. 206 ConcatenatedVAOPTResultToks.back() = LHS; 207 if (CurTokenIdx == NumVAOptTokens) 208 break; 209 } 210 ConcatenatedVAOPTResultToks.push_back(VAOPTTokens[CurTokenIdx]); 211 } 212 213 ConcatenatedVAOPTResultToks.push_back(VCtx.getEOFTok()); 214 // Get the SourceLocation that represents the start location within 215 // the macro definition that marks where this string is substituted 216 // into: i.e. the __VA_OPT__ and the ')' within the spelling of the 217 // macro definition, and use it to indicate that the stringified token 218 // was generated from that location. 219 const SourceLocation ExpansionLocStartWithinMacro = 220 getExpansionLocForMacroDefLoc(VCtx.getVAOptLoc()); 221 const SourceLocation ExpansionLocEndWithinMacro = 222 getExpansionLocForMacroDefLoc(VAOPTClosingParenLoc); 223 224 Token StringifiedVAOPT = MacroArgs::StringifyArgument( 225 &ConcatenatedVAOPTResultToks[0], PP, VCtx.hasCharifyBefore() /*Charify*/, 226 ExpansionLocStartWithinMacro, ExpansionLocEndWithinMacro); 227 228 if (VCtx.getLeadingSpaceForStringifiedToken()) 229 StringifiedVAOPT.setFlag(Token::LeadingSpace); 230 231 StringifiedVAOPT.setFlag(Token::StringifiedInMacro); 232 // Resize (shrink) the token stream to just capture this stringified token. 233 ResultToks.resize(NumToksPriorToVAOpt + 1); 234 ResultToks.back() = StringifiedVAOPT; 235} 236 237/// Expand the arguments of a function-like macro so that we can quickly 238/// return preexpanded tokens from Tokens. 239void TokenLexer::ExpandFunctionArguments() { 240 SmallVector<Token, 128> ResultToks; 241 242 // Loop through 'Tokens', expanding them into ResultToks. Keep 243 // track of whether we change anything. If not, no need to keep them. If so, 244 // we install the newly expanded sequence as the new 'Tokens' list. 245 bool MadeChange = false; 246 247 const bool CalledWithVariadicArguments = 248 ActualArgs->invokedWithVariadicArgument(Macro); 249 250 VAOptExpansionContext VCtx(PP); 251 252 for (unsigned I = 0, E = NumTokens; I != E; ++I) { 253 const Token &CurTok = Tokens[I]; 254 // We don't want a space for the next token after a paste 255 // operator. In valid code, the token will get smooshed onto the 256 // preceding one anyway. In assembler-with-cpp mode, invalid 257 // pastes are allowed through: in this case, we do not want the 258 // extra whitespace to be added. For example, we want ". ## foo" 259 // -> ".foo" not ". foo". 260 if (I != 0 && !Tokens[I-1].is(tok::hashhash) && CurTok.hasLeadingSpace()) 261 NextTokGetsSpace = true; 262 263 if (VCtx.isVAOptToken(CurTok)) { 264 MadeChange = true; 265 assert(Tokens[I + 1].is(tok::l_paren) && 266 "__VA_OPT__ must be followed by '('"); 267 268 ++I; // Skip the l_paren 269 VCtx.sawVAOptFollowedByOpeningParens(CurTok.getLocation(), 270 ResultToks.size()); 271 272 continue; 273 } 274 275 // We have entered into the __VA_OPT__ context, so handle tokens 276 // appropriately. 277 if (VCtx.isInVAOpt()) { 278 // If we are about to process a token that is either an argument to 279 // __VA_OPT__ or its closing rparen, then: 280 // 1) If the token is the closing rparen that exits us out of __VA_OPT__, 281 // perform any necessary stringification or placemarker processing, 282 // and/or skip to the next token. 283 // 2) else if macro was invoked without variadic arguments skip this 284 // token. 285 // 3) else (macro was invoked with variadic arguments) process the token 286 // normally. 287 288 if (Tokens[I].is(tok::l_paren)) 289 VCtx.sawOpeningParen(Tokens[I].getLocation()); 290 // Continue skipping tokens within __VA_OPT__ if the macro was not 291 // called with variadic arguments, else let the rest of the loop handle 292 // this token. Note sawClosingParen() returns true only if the r_paren matches 293 // the closing r_paren of the __VA_OPT__. 294 if (!Tokens[I].is(tok::r_paren) || !VCtx.sawClosingParen()) { 295 if (!CalledWithVariadicArguments) { 296 // Skip this token. 297 continue; 298 } 299 // ... else the macro was called with variadic arguments, and we do not 300 // have a closing rparen - so process this token normally. 301 } else { 302 // Current token is the closing r_paren which marks the end of the 303 // __VA_OPT__ invocation, so handle any place-marker pasting (if 304 // empty) by removing hashhash either before (if exists) or after. And 305 // also stringify the entire contents if VAOPT was preceded by a hash, 306 // but do so only after any token concatenation that needs to occur 307 // within the contents of VAOPT. 308 309 if (VCtx.hasStringifyOrCharifyBefore()) { 310 // Replace all the tokens just added from within VAOPT into a single 311 // stringified token. This requires token-pasting to eagerly occur 312 // within these tokens. If either the contents of VAOPT were empty 313 // or the macro wasn't called with any variadic arguments, the result 314 // is a token that represents an empty string. 315 stringifyVAOPTContents(ResultToks, VCtx, 316 /*ClosingParenLoc*/ Tokens[I].getLocation()); 317 318 } else if (/*No tokens within VAOPT*/ !( 319 ResultToks.size() - VCtx.getNumberOfTokensPriorToVAOpt())) { 320 // Treat VAOPT as a placemarker token. Eat either the '##' before the 321 // RHS/VAOPT (if one exists, suggesting that the LHS (if any) to that 322 // hashhash was not a placemarker) or the '##' 323 // after VAOPT, but not both. 324 325 if (ResultToks.size() && ResultToks.back().is(tok::hashhash)) { 326 ResultToks.pop_back(); 327 } else if ((I + 1 != E) && Tokens[I + 1].is(tok::hashhash)) { 328 ++I; // Skip the following hashhash. 329 } 330 } 331 VCtx.reset(); 332 // We processed __VA_OPT__'s closing paren (and the exit out of 333 // __VA_OPT__), so skip to the next token. 334 continue; 335 } 336 } 337 338 // If we found the stringify operator, get the argument stringified. The 339 // preprocessor already verified that the following token is a macro 340 // parameter or __VA_OPT__ when the #define was lexed. 341 342 if (CurTok.isOneOf(tok::hash, tok::hashat)) { 343 int ArgNo = Macro->getParameterNum(Tokens[I+1].getIdentifierInfo()); 344 assert((ArgNo != -1 || VCtx.isVAOptToken(Tokens[I + 1])) && 345 "Token following # is not an argument or __VA_OPT__!"); 346 347 if (ArgNo == -1) { 348 // Handle the __VA_OPT__ case. 349 VCtx.sawHashOrHashAtBefore(NextTokGetsSpace, 350 CurTok.is(tok::hashat)); 351 continue; 352 } 353 // Else handle the simple argument case. 354 SourceLocation ExpansionLocStart = 355 getExpansionLocForMacroDefLoc(CurTok.getLocation()); 356 SourceLocation ExpansionLocEnd = 357 getExpansionLocForMacroDefLoc(Tokens[I+1].getLocation()); 358 359 Token Res; 360 if (CurTok.is(tok::hash)) // Stringify 361 Res = ActualArgs->getStringifiedArgument(ArgNo, PP, 362 ExpansionLocStart, 363 ExpansionLocEnd); 364 else { 365 // 'charify': don't bother caching these. 366 Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo), 367 PP, true, 368 ExpansionLocStart, 369 ExpansionLocEnd); 370 } 371 Res.setFlag(Token::StringifiedInMacro); 372 373 // The stringified/charified string leading space flag gets set to match 374 // the #/#@ operator. 375 if (NextTokGetsSpace) 376 Res.setFlag(Token::LeadingSpace); 377 378 ResultToks.push_back(Res); 379 MadeChange = true; 380 ++I; // Skip arg name. 381 NextTokGetsSpace = false; 382 continue; 383 } 384 385 // Find out if there is a paste (##) operator before or after the token. 386 bool NonEmptyPasteBefore = 387 !ResultToks.empty() && ResultToks.back().is(tok::hashhash); 388 bool PasteBefore = I != 0 && Tokens[I-1].is(tok::hashhash); 389 bool PasteAfter = I+1 != E && Tokens[I+1].is(tok::hashhash); 390 391 assert((!NonEmptyPasteBefore || PasteBefore || VCtx.isInVAOpt()) && 392 "unexpected ## in ResultToks"); 393 394 // Otherwise, if this is not an argument token, just add the token to the 395 // output buffer. 396 IdentifierInfo *II = CurTok.getIdentifierInfo(); 397 int ArgNo = II ? Macro->getParameterNum(II) : -1; 398 if (ArgNo == -1) { 399 // This isn't an argument, just add it. 400 ResultToks.push_back(CurTok); 401 402 if (NextTokGetsSpace) { 403 ResultToks.back().setFlag(Token::LeadingSpace); 404 NextTokGetsSpace = false; 405 } else if (PasteBefore && !NonEmptyPasteBefore) 406 ResultToks.back().clearFlag(Token::LeadingSpace); 407 408 continue; 409 } 410 411 // An argument is expanded somehow, the result is different than the 412 // input. 413 MadeChange = true; 414 415 // Otherwise, this is a use of the argument. 416 417 // In Microsoft mode, remove the comma before __VA_ARGS__ to ensure there 418 // are no trailing commas if __VA_ARGS__ is empty. 419 if (!PasteBefore && ActualArgs->isVarargsElidedUse() && 420 MaybeRemoveCommaBeforeVaArgs(ResultToks, 421 /*HasPasteOperator=*/false, 422 Macro, ArgNo, PP)) 423 continue; 424 425 // If it is not the LHS/RHS of a ## operator, we must pre-expand the 426 // argument and substitute the expanded tokens into the result. This is 427 // C99 6.10.3.1p1. 428 if (!PasteBefore && !PasteAfter) { 429 const Token *ResultArgToks; 430 431 // Only preexpand the argument if it could possibly need it. This 432 // avoids some work in common cases. 433 const Token *ArgTok = ActualArgs->getUnexpArgument(ArgNo); 434 if (ActualArgs->ArgNeedsPreexpansion(ArgTok, PP)) 435 ResultArgToks = &ActualArgs->getPreExpArgument(ArgNo, PP)[0]; 436 else 437 ResultArgToks = ArgTok; // Use non-preexpanded tokens. 438 439 // If the arg token expanded into anything, append it. 440 if (ResultArgToks->isNot(tok::eof)) { 441 size_t FirstResult = ResultToks.size(); 442 unsigned NumToks = MacroArgs::getArgLength(ResultArgToks); 443 ResultToks.append(ResultArgToks, ResultArgToks+NumToks); 444 445 // In Microsoft-compatibility mode, we follow MSVC's preprocessing 446 // behavior by not considering single commas from nested macro 447 // expansions as argument separators. Set a flag on the token so we can 448 // test for this later when the macro expansion is processed. 449 if (PP.getLangOpts().MSVCCompat && NumToks == 1 && 450 ResultToks.back().is(tok::comma)) 451 ResultToks.back().setFlag(Token::IgnoredComma); 452 453 // If the '##' came from expanding an argument, turn it into 'unknown' 454 // to avoid pasting. 455 for (Token &Tok : llvm::make_range(ResultToks.begin() + FirstResult, 456 ResultToks.end())) { 457 if (Tok.is(tok::hashhash)) 458 Tok.setKind(tok::unknown); 459 } 460 461 if(ExpandLocStart.isValid()) { 462 updateLocForMacroArgTokens(CurTok.getLocation(), 463 ResultToks.begin()+FirstResult, 464 ResultToks.end()); 465 } 466 467 // If any tokens were substituted from the argument, the whitespace 468 // before the first token should match the whitespace of the arg 469 // identifier. 470 ResultToks[FirstResult].setFlagValue(Token::LeadingSpace, 471 NextTokGetsSpace); 472 ResultToks[FirstResult].setFlagValue(Token::StartOfLine, false); 473 NextTokGetsSpace = false; 474 } 475 continue; 476 } 477 478 // Okay, we have a token that is either the LHS or RHS of a paste (##) 479 // argument. It gets substituted as its non-pre-expanded tokens. 480 const Token *ArgToks = ActualArgs->getUnexpArgument(ArgNo); 481 unsigned NumToks = MacroArgs::getArgLength(ArgToks); 482 if (NumToks) { // Not an empty argument? 483 bool VaArgsPseudoPaste = false; 484 // If this is the GNU ", ## __VA_ARGS__" extension, and we just learned 485 // that __VA_ARGS__ expands to multiple tokens, avoid a pasting error when 486 // the expander trys to paste ',' with the first token of the __VA_ARGS__ 487 // expansion. 488 if (NonEmptyPasteBefore && ResultToks.size() >= 2 && 489 ResultToks[ResultToks.size()-2].is(tok::comma) && 490 (unsigned)ArgNo == Macro->getNumParams()-1 && 491 Macro->isVariadic()) { 492 VaArgsPseudoPaste = true; 493 // Remove the paste operator, report use of the extension. 494 PP.Diag(ResultToks.pop_back_val().getLocation(), diag::ext_paste_comma); 495 } 496 497 ResultToks.append(ArgToks, ArgToks+NumToks); 498 499 // If the '##' came from expanding an argument, turn it into 'unknown' 500 // to avoid pasting. 501 for (Token &Tok : llvm::make_range(ResultToks.end() - NumToks, 502 ResultToks.end())) { 503 if (Tok.is(tok::hashhash)) 504 Tok.setKind(tok::unknown); 505 } 506 507 if (ExpandLocStart.isValid()) { 508 updateLocForMacroArgTokens(CurTok.getLocation(), 509 ResultToks.end()-NumToks, ResultToks.end()); 510 } 511 512 // Transfer the leading whitespace information from the token 513 // (the macro argument) onto the first token of the 514 // expansion. Note that we don't do this for the GNU 515 // pseudo-paste extension ", ## __VA_ARGS__". 516 if (!VaArgsPseudoPaste) { 517 ResultToks[ResultToks.size() - NumToks].setFlagValue(Token::StartOfLine, 518 false); 519 ResultToks[ResultToks.size() - NumToks].setFlagValue( 520 Token::LeadingSpace, NextTokGetsSpace); 521 } 522 523 NextTokGetsSpace = false; 524 continue; 525 } 526 527 // If an empty argument is on the LHS or RHS of a paste, the standard (C99 528 // 6.10.3.3p2,3) calls for a bunch of placemarker stuff to occur. We 529 // implement this by eating ## operators when a LHS or RHS expands to 530 // empty. 531 if (PasteAfter) { 532 // Discard the argument token and skip (don't copy to the expansion 533 // buffer) the paste operator after it. 534 ++I; 535 continue; 536 } 537 538 // If this is on the RHS of a paste operator, we've already copied the 539 // paste operator to the ResultToks list, unless the LHS was empty too. 540 // Remove it. 541 assert(PasteBefore); 542 if (NonEmptyPasteBefore) { 543 assert(ResultToks.back().is(tok::hashhash)); 544 // Do not remove the paste operator if it is the one before __VA_OPT__ 545 // (and we are still processing tokens within VA_OPT). We handle the case 546 // of removing the paste operator if __VA_OPT__ reduces to the notional 547 // placemarker above when we encounter the closing paren of VA_OPT. 548 if (!VCtx.isInVAOpt() || 549 ResultToks.size() > VCtx.getNumberOfTokensPriorToVAOpt()) 550 ResultToks.pop_back(); 551 } 552 553 // If this is the __VA_ARGS__ token, and if the argument wasn't provided, 554 // and if the macro had at least one real argument, and if the token before 555 // the ## was a comma, remove the comma. This is a GCC extension which is 556 // disabled when using -std=c99. 557 if (ActualArgs->isVarargsElidedUse()) 558 MaybeRemoveCommaBeforeVaArgs(ResultToks, 559 /*HasPasteOperator=*/true, 560 Macro, ArgNo, PP); 561 } 562 563 // If anything changed, install this as the new Tokens list. 564 if (MadeChange) { 565 assert(!OwnsTokens && "This would leak if we already own the token list"); 566 // This is deleted in the dtor. 567 NumTokens = ResultToks.size(); 568 // The tokens will be added to Preprocessor's cache and will be removed 569 // when this TokenLexer finishes lexing them. 570 Tokens = PP.cacheMacroExpandedTokens(this, ResultToks); 571 572 // The preprocessor cache of macro expanded tokens owns these tokens,not us. 573 OwnsTokens = false; 574 } 575} 576 577/// \brief Checks if two tokens form wide string literal. 578static bool isWideStringLiteralFromMacro(const Token &FirstTok, 579 const Token &SecondTok) { 580 return FirstTok.is(tok::identifier) && 581 FirstTok.getIdentifierInfo()->isStr("L") && SecondTok.isLiteral() && 582 SecondTok.stringifiedInMacro(); 583} 584 585/// Lex - Lex and return a token from this macro stream. 586bool TokenLexer::Lex(Token &Tok) { 587 // Lexing off the end of the macro, pop this macro off the expansion stack. 588 if (isAtEnd()) { 589 // If this is a macro (not a token stream), mark the macro enabled now 590 // that it is no longer being expanded. 591 if (Macro) Macro->EnableMacro(); 592 593 Tok.startToken(); 594 Tok.setFlagValue(Token::StartOfLine , AtStartOfLine); 595 Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace || NextTokGetsSpace); 596 if (CurTokenIdx == 0) 597 Tok.setFlag(Token::LeadingEmptyMacro); 598 return PP.HandleEndOfTokenLexer(Tok); 599 } 600 601 SourceManager &SM = PP.getSourceManager(); 602 603 // If this is the first token of the expanded result, we inherit spacing 604 // properties later. 605 bool isFirstToken = CurTokenIdx == 0; 606 607 // Get the next token to return. 608 Tok = Tokens[CurTokenIdx++]; 609 610 bool TokenIsFromPaste = false; 611 612 // If this token is followed by a token paste (##) operator, paste the tokens! 613 // Note that ## is a normal token when not expanding a macro. 614 if (!isAtEnd() && Macro && 615 (Tokens[CurTokenIdx].is(tok::hashhash) || 616 // Special processing of L#x macros in -fms-compatibility mode. 617 // Microsoft compiler is able to form a wide string literal from 618 // 'L#macro_arg' construct in a function-like macro. 619 (PP.getLangOpts().MSVCCompat && 620 isWideStringLiteralFromMacro(Tok, Tokens[CurTokenIdx])))) { 621 // When handling the microsoft /##/ extension, the final token is 622 // returned by pasteTokens, not the pasted token. 623 if (pasteTokens(Tok)) 624 return true; 625 626 TokenIsFromPaste = true; 627 } 628 629 // The token's current location indicate where the token was lexed from. We 630 // need this information to compute the spelling of the token, but any 631 // diagnostics for the expanded token should appear as if they came from 632 // ExpansionLoc. Pull this information together into a new SourceLocation 633 // that captures all of this. 634 if (ExpandLocStart.isValid() && // Don't do this for token streams. 635 // Check that the token's location was not already set properly. 636 SM.isBeforeInSLocAddrSpace(Tok.getLocation(), MacroStartSLocOffset)) { 637 SourceLocation instLoc; 638 if (Tok.is(tok::comment)) { 639 instLoc = SM.createExpansionLoc(Tok.getLocation(), 640 ExpandLocStart, 641 ExpandLocEnd, 642 Tok.getLength()); 643 } else { 644 instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation()); 645 } 646 647 Tok.setLocation(instLoc); 648 } 649 650 // If this is the first token, set the lexical properties of the token to 651 // match the lexical properties of the macro identifier. 652 if (isFirstToken) { 653 Tok.setFlagValue(Token::StartOfLine , AtStartOfLine); 654 Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace); 655 } else { 656 // If this is not the first token, we may still need to pass through 657 // leading whitespace if we've expanded a macro. 658 if (AtStartOfLine) Tok.setFlag(Token::StartOfLine); 659 if (HasLeadingSpace) Tok.setFlag(Token::LeadingSpace); 660 } 661 AtStartOfLine = false; 662 HasLeadingSpace = false; 663 664 // Handle recursive expansion! 665 if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) { 666 // Change the kind of this identifier to the appropriate token kind, e.g. 667 // turning "for" into a keyword. 668 IdentifierInfo *II = Tok.getIdentifierInfo(); 669 Tok.setKind(II->getTokenID()); 670 671 // If this identifier was poisoned and from a paste, emit an error. This 672 // won't be handled by Preprocessor::HandleIdentifier because this is coming 673 // from a macro expansion. 674 if (II->isPoisoned() && TokenIsFromPaste) { 675 PP.HandlePoisonedIdentifier(Tok); 676 } 677 678 if (!DisableMacroExpansion && II->isHandleIdentifierCase()) 679 return PP.HandleIdentifier(Tok); 680 } 681 682 // Otherwise, return a normal token. 683 return true; 684} 685 686bool TokenLexer::pasteTokens(Token &Tok) { 687 return pasteTokens(Tok, llvm::makeArrayRef(Tokens, NumTokens), CurTokenIdx); 688} 689 690/// LHSTok is the LHS of a ## operator, and CurTokenIdx is the ## 691/// operator. Read the ## and RHS, and paste the LHS/RHS together. If there 692/// are more ## after it, chomp them iteratively. Return the result as LHSTok. 693/// If this returns true, the caller should immediately return the token. 694bool TokenLexer::pasteTokens(Token &LHSTok, ArrayRef<Token> TokenStream, 695 unsigned int &CurIdx) { 696 assert(CurIdx > 0 && "## can not be the first token within tokens"); 697 assert((TokenStream[CurIdx].is(tok::hashhash) || 698 (PP.getLangOpts().MSVCCompat && 699 isWideStringLiteralFromMacro(LHSTok, TokenStream[CurIdx]))) && 700 "Token at this Index must be ## or part of the MSVC 'L " 701 "#macro-arg' pasting pair"); 702 703 // MSVC: If previous token was pasted, this must be a recovery from an invalid 704 // paste operation. Ignore spaces before this token to mimic MSVC output. 705 // Required for generating valid UUID strings in some MS headers. 706 if (PP.getLangOpts().MicrosoftExt && (CurIdx >= 2) && 707 TokenStream[CurIdx - 2].is(tok::hashhash)) 708 LHSTok.clearFlag(Token::LeadingSpace); 709 710 SmallString<128> Buffer; 711 const char *ResultTokStrPtr = nullptr; 712 SourceLocation StartLoc = LHSTok.getLocation(); 713 SourceLocation PasteOpLoc; 714 715 auto IsAtEnd = [&TokenStream, &CurIdx] { 716 return TokenStream.size() == CurIdx; 717 }; 718 719 do { 720 // Consume the ## operator if any. 721 PasteOpLoc = TokenStream[CurIdx].getLocation(); 722 if (TokenStream[CurIdx].is(tok::hashhash)) 723 ++CurIdx; 724 assert(!IsAtEnd() && "No token on the RHS of a paste operator!"); 725 726 // Get the RHS token. 727 const Token &RHS = TokenStream[CurIdx]; 728 729 // Allocate space for the result token. This is guaranteed to be enough for 730 // the two tokens. 731 Buffer.resize(LHSTok.getLength() + RHS.getLength()); 732 733 // Get the spelling of the LHS token in Buffer. 734 const char *BufPtr = &Buffer[0]; 735 bool Invalid = false; 736 unsigned LHSLen = PP.getSpelling(LHSTok, BufPtr, &Invalid); 737 if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer! 738 memcpy(&Buffer[0], BufPtr, LHSLen); 739 if (Invalid) 740 return true; 741 742 BufPtr = Buffer.data() + LHSLen; 743 unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid); 744 if (Invalid) 745 return true; 746 if (RHSLen && BufPtr != &Buffer[LHSLen]) 747 // Really, we want the chars in Buffer! 748 memcpy(&Buffer[LHSLen], BufPtr, RHSLen); 749 750 // Trim excess space. 751 Buffer.resize(LHSLen+RHSLen); 752 753 // Plop the pasted result (including the trailing newline and null) into a 754 // scratch buffer where we can lex it. 755 Token ResultTokTmp; 756 ResultTokTmp.startToken(); 757 758 // Claim that the tmp token is a string_literal so that we can get the 759 // character pointer back from CreateString in getLiteralData(). 760 ResultTokTmp.setKind(tok::string_literal); 761 PP.CreateString(Buffer, ResultTokTmp); 762 SourceLocation ResultTokLoc = ResultTokTmp.getLocation(); 763 ResultTokStrPtr = ResultTokTmp.getLiteralData(); 764 765 // Lex the resultant pasted token into Result. 766 Token Result; 767 768 if (LHSTok.isAnyIdentifier() && RHS.isAnyIdentifier()) { 769 // Common paste case: identifier+identifier = identifier. Avoid creating 770 // a lexer and other overhead. 771 PP.IncrementPasteCounter(true); 772 Result.startToken(); 773 Result.setKind(tok::raw_identifier); 774 Result.setRawIdentifierData(ResultTokStrPtr); 775 Result.setLocation(ResultTokLoc); 776 Result.setLength(LHSLen+RHSLen); 777 } else { 778 PP.IncrementPasteCounter(false); 779 780 assert(ResultTokLoc.isFileID() && 781 "Should be a raw location into scratch buffer"); 782 SourceManager &SourceMgr = PP.getSourceManager(); 783 FileID LocFileID = SourceMgr.getFileID(ResultTokLoc); 784 785 bool Invalid = false; 786 const char *ScratchBufStart 787 = SourceMgr.getBufferData(LocFileID, &Invalid).data(); 788 if (Invalid) 789 return false; 790 791 // Make a lexer to lex this string from. Lex just this one token. 792 // Make a lexer object so that we lex and expand the paste result. 793 Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID), 794 PP.getLangOpts(), ScratchBufStart, 795 ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen); 796 797 // Lex a token in raw mode. This way it won't look up identifiers 798 // automatically, lexing off the end will return an eof token, and 799 // warnings are disabled. This returns true if the result token is the 800 // entire buffer. 801 bool isInvalid = !TL.LexFromRawLexer(Result); 802 803 // If we got an EOF token, we didn't form even ONE token. For example, we 804 // did "/ ## /" to get "//". 805 isInvalid |= Result.is(tok::eof); 806 807 // If pasting the two tokens didn't form a full new token, this is an 808 // error. This occurs with "x ## +" and other stuff. Return with LHSTok 809 // unmodified and with RHS as the next token to lex. 810 if (isInvalid) { 811 // Explicitly convert the token location to have proper expansion 812 // information so that the user knows where it came from. 813 SourceManager &SM = PP.getSourceManager(); 814 SourceLocation Loc = 815 SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2); 816 817 // Test for the Microsoft extension of /##/ turning into // here on the 818 // error path. 819 if (PP.getLangOpts().MicrosoftExt && LHSTok.is(tok::slash) && 820 RHS.is(tok::slash)) { 821 HandleMicrosoftCommentPaste(LHSTok, Loc); 822 return true; 823 } 824 825 // Do not emit the error when preprocessing assembler code. 826 if (!PP.getLangOpts().AsmPreprocessor) { 827 // If we're in microsoft extensions mode, downgrade this from a hard 828 // error to an extension that defaults to an error. This allows 829 // disabling it. 830 PP.Diag(Loc, PP.getLangOpts().MicrosoftExt ? diag::ext_pp_bad_paste_ms 831 : diag::err_pp_bad_paste) 832 << Buffer; 833 } 834 835 // An error has occurred so exit loop. 836 break; 837 } 838 839 // Turn ## into 'unknown' to avoid # ## # from looking like a paste 840 // operator. 841 if (Result.is(tok::hashhash)) 842 Result.setKind(tok::unknown); 843 } 844 845 // Transfer properties of the LHS over the Result. 846 Result.setFlagValue(Token::StartOfLine , LHSTok.isAtStartOfLine()); 847 Result.setFlagValue(Token::LeadingSpace, LHSTok.hasLeadingSpace()); 848 849 // Finally, replace LHS with the result, consume the RHS, and iterate. 850 ++CurIdx; 851 LHSTok = Result; 852 } while (!IsAtEnd() && TokenStream[CurIdx].is(tok::hashhash)); 853 854 SourceLocation EndLoc = TokenStream[CurIdx - 1].getLocation(); 855 856 // The token's current location indicate where the token was lexed from. We 857 // need this information to compute the spelling of the token, but any 858 // diagnostics for the expanded token should appear as if the token was 859 // expanded from the full ## expression. Pull this information together into 860 // a new SourceLocation that captures all of this. 861 SourceManager &SM = PP.getSourceManager(); 862 if (StartLoc.isFileID()) 863 StartLoc = getExpansionLocForMacroDefLoc(StartLoc); 864 if (EndLoc.isFileID()) 865 EndLoc = getExpansionLocForMacroDefLoc(EndLoc); 866 FileID MacroFID = SM.getFileID(MacroExpansionStart); 867 while (SM.getFileID(StartLoc) != MacroFID) 868 StartLoc = SM.getImmediateExpansionRange(StartLoc).first; 869 while (SM.getFileID(EndLoc) != MacroFID) 870 EndLoc = SM.getImmediateExpansionRange(EndLoc).second; 871 872 LHSTok.setLocation(SM.createExpansionLoc(LHSTok.getLocation(), StartLoc, EndLoc, 873 LHSTok.getLength())); 874 875 // Now that we got the result token, it will be subject to expansion. Since 876 // token pasting re-lexes the result token in raw mode, identifier information 877 // isn't looked up. As such, if the result is an identifier, look up id info. 878 if (LHSTok.is(tok::raw_identifier)) { 879 // Look up the identifier info for the token. We disabled identifier lookup 880 // by saying we're skipping contents, so we need to do this manually. 881 PP.LookUpIdentifierInfo(LHSTok); 882 } 883 return false; 884} 885 886/// isNextTokenLParen - If the next token lexed will pop this macro off the 887/// expansion stack, return 2. If the next unexpanded token is a '(', return 888/// 1, otherwise return 0. 889unsigned TokenLexer::isNextTokenLParen() const { 890 // Out of tokens? 891 if (isAtEnd()) 892 return 2; 893 return Tokens[CurTokenIdx].is(tok::l_paren); 894} 895 896/// isParsingPreprocessorDirective - Return true if we are in the middle of a 897/// preprocessor directive. 898bool TokenLexer::isParsingPreprocessorDirective() const { 899 return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd(); 900} 901 902/// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes 903/// together to form a comment that comments out everything in the current 904/// macro, other active macros, and anything left on the current physical 905/// source line of the expanded buffer. Handle this by returning the 906/// first token on the next line. 907void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok, SourceLocation OpLoc) { 908 PP.Diag(OpLoc, diag::ext_comment_paste_microsoft); 909 910 // We 'comment out' the rest of this macro by just ignoring the rest of the 911 // tokens that have not been lexed yet, if any. 912 913 // Since this must be a macro, mark the macro enabled now that it is no longer 914 // being expanded. 915 assert(Macro && "Token streams can't paste comments"); 916 Macro->EnableMacro(); 917 918 PP.HandleMicrosoftCommentPaste(Tok); 919} 920 921/// \brief If \arg loc is a file ID and points inside the current macro 922/// definition, returns the appropriate source location pointing at the 923/// macro expansion source location entry, otherwise it returns an invalid 924/// SourceLocation. 925SourceLocation 926TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const { 927 assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() && 928 "Not appropriate for token streams"); 929 assert(loc.isValid() && loc.isFileID()); 930 931 SourceManager &SM = PP.getSourceManager(); 932 assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) && 933 "Expected loc to come from the macro definition"); 934 935 unsigned relativeOffset = 0; 936 SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset); 937 return MacroExpansionStart.getLocWithOffset(relativeOffset); 938} 939 940/// \brief Finds the tokens that are consecutive (from the same FileID) 941/// creates a single SLocEntry, and assigns SourceLocations to each token that 942/// point to that SLocEntry. e.g for 943/// assert(foo == bar); 944/// There will be a single SLocEntry for the "foo == bar" chunk and locations 945/// for the 'foo', '==', 'bar' tokens will point inside that chunk. 946/// 947/// \arg begin_tokens will be updated to a position past all the found 948/// consecutive tokens. 949static void updateConsecutiveMacroArgTokens(SourceManager &SM, 950 SourceLocation InstLoc, 951 Token *&begin_tokens, 952 Token * end_tokens) { 953 assert(begin_tokens < end_tokens); 954 955 SourceLocation FirstLoc = begin_tokens->getLocation(); 956 SourceLocation CurLoc = FirstLoc; 957 958 // Compare the source location offset of tokens and group together tokens that 959 // are close, even if their locations point to different FileIDs. e.g. 960 // 961 // |bar | foo | cake | (3 tokens from 3 consecutive FileIDs) 962 // ^ ^ 963 // |bar foo cake| (one SLocEntry chunk for all tokens) 964 // 965 // we can perform this "merge" since the token's spelling location depends 966 // on the relative offset. 967 968 Token *NextTok = begin_tokens + 1; 969 for (; NextTok < end_tokens; ++NextTok) { 970 SourceLocation NextLoc = NextTok->getLocation(); 971 if (CurLoc.isFileID() != NextLoc.isFileID()) 972 break; // Token from different kind of FileID. 973 974 int RelOffs; 975 if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs)) 976 break; // Token from different local/loaded location. 977 // Check that token is not before the previous token or more than 50 978 // "characters" away. 979 if (RelOffs < 0 || RelOffs > 50) 980 break; 981 982 if (CurLoc.isMacroID() && !SM.isWrittenInSameFile(CurLoc, NextLoc)) 983 break; // Token from a different macro. 984 985 CurLoc = NextLoc; 986 } 987 988 // For the consecutive tokens, find the length of the SLocEntry to contain 989 // all of them. 990 Token &LastConsecutiveTok = *(NextTok-1); 991 int LastRelOffs = 0; 992 SM.isInSameSLocAddrSpace(FirstLoc, LastConsecutiveTok.getLocation(), 993 &LastRelOffs); 994 unsigned FullLength = LastRelOffs + LastConsecutiveTok.getLength(); 995 996 // Create a macro expansion SLocEntry that will "contain" all of the tokens. 997 SourceLocation Expansion = 998 SM.createMacroArgExpansionLoc(FirstLoc, InstLoc,FullLength); 999 1000 // Change the location of the tokens from the spelling location to the new 1001 // expanded location. 1002 for (; begin_tokens < NextTok; ++begin_tokens) { 1003 Token &Tok = *begin_tokens; 1004 int RelOffs = 0; 1005 SM.isInSameSLocAddrSpace(FirstLoc, Tok.getLocation(), &RelOffs); 1006 Tok.setLocation(Expansion.getLocWithOffset(RelOffs)); 1007 } 1008} 1009 1010/// \brief Creates SLocEntries and updates the locations of macro argument 1011/// tokens to their new expanded locations. 1012/// 1013/// \param ArgIdSpellLoc the location of the macro argument id inside the macro 1014/// definition. 1015void TokenLexer::updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc, 1016 Token *begin_tokens, 1017 Token *end_tokens) { 1018 SourceManager &SM = PP.getSourceManager(); 1019 1020 SourceLocation InstLoc = 1021 getExpansionLocForMacroDefLoc(ArgIdSpellLoc); 1022 1023 while (begin_tokens < end_tokens) { 1024 // If there's only one token just create a SLocEntry for it. 1025 if (end_tokens - begin_tokens == 1) { 1026 Token &Tok = *begin_tokens; 1027 Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(), 1028 InstLoc, 1029 Tok.getLength())); 1030 return; 1031 } 1032 1033 updateConsecutiveMacroArgTokens(SM, InstLoc, begin_tokens, end_tokens); 1034 } 1035} 1036 1037void TokenLexer::PropagateLineStartLeadingSpaceInfo(Token &Result) { 1038 AtStartOfLine = Result.isAtStartOfLine(); 1039 HasLeadingSpace = Result.hasLeadingSpace(); 1040} 1041