PPDirectives.cpp revision 0ea76727ae91bca918a8414ed85b530eddcfedeb
1//===--- PPDirectives.cpp - Directive Handling for Preprocessor -----------===// 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 # directive processing for the Preprocessor. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Lex/Preprocessor.h" 15#include "clang/Lex/HeaderSearch.h" 16#include "clang/Lex/MacroInfo.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Basic/SourceManager.h" 19using namespace clang; 20 21//===----------------------------------------------------------------------===// 22// Utility Methods for Preprocessor Directive Handling. 23//===----------------------------------------------------------------------===// 24 25MacroInfo* Preprocessor::AllocateMacroInfo(SourceLocation L) { 26 MacroInfo *MI; 27 28 if (!MICache.empty()) { 29 MI = MICache.back(); 30 MICache.pop_back(); 31 } 32 else MI = (MacroInfo*) BP.Allocate<MacroInfo>(); 33 new (MI) MacroInfo(L); 34 return MI; 35} 36 37/// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the 38/// current line until the tok::eom token is found. 39void Preprocessor::DiscardUntilEndOfDirective() { 40 Token Tmp; 41 do { 42 LexUnexpandedToken(Tmp); 43 } while (Tmp.isNot(tok::eom)); 44} 45 46/// ReadMacroName - Lex and validate a macro name, which occurs after a 47/// #define or #undef. This sets the token kind to eom and discards the rest 48/// of the macro line if the macro name is invalid. isDefineUndef is 1 if 49/// this is due to a a #define, 2 if #undef directive, 0 if it is something 50/// else (e.g. #ifdef). 51void Preprocessor::ReadMacroName(Token &MacroNameTok, char isDefineUndef) { 52 // Read the token, don't allow macro expansion on it. 53 LexUnexpandedToken(MacroNameTok); 54 55 // Missing macro name? 56 if (MacroNameTok.is(tok::eom)) { 57 Diag(MacroNameTok, diag::err_pp_missing_macro_name); 58 return; 59 } 60 61 IdentifierInfo *II = MacroNameTok.getIdentifierInfo(); 62 if (II == 0) { 63 std::string Spelling = getSpelling(MacroNameTok); 64 const IdentifierInfo &Info = Identifiers.get(Spelling); 65 if (Info.isCPlusPlusOperatorKeyword()) 66 // C++ 2.5p2: Alternative tokens behave the same as its primary token 67 // except for their spellings. 68 Diag(MacroNameTok, diag::err_pp_operator_used_as_macro_name) << Spelling; 69 else 70 Diag(MacroNameTok, diag::err_pp_macro_not_identifier); 71 // Fall through on error. 72 } else if (isDefineUndef && II->getPPKeywordID() == tok::pp_defined) { 73 // Error if defining "defined": C99 6.10.8.4. 74 Diag(MacroNameTok, diag::err_defined_macro_name); 75 } else if (isDefineUndef && II->hasMacroDefinition() && 76 getMacroInfo(II)->isBuiltinMacro()) { 77 // Error if defining "__LINE__" and other builtins: C99 6.10.8.4. 78 if (isDefineUndef == 1) 79 Diag(MacroNameTok, diag::pp_redef_builtin_macro); 80 else 81 Diag(MacroNameTok, diag::pp_undef_builtin_macro); 82 } else { 83 // Okay, we got a good identifier node. Return it. 84 return; 85 } 86 87 // Invalid macro name, read and discard the rest of the line. Then set the 88 // token kind to tok::eom. 89 MacroNameTok.setKind(tok::eom); 90 return DiscardUntilEndOfDirective(); 91} 92 93/// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If 94/// not, emit a diagnostic and consume up until the eom. 95void Preprocessor::CheckEndOfDirective(const char *DirType) { 96 Token Tmp; 97 // Lex unexpanded tokens: macros might expand to zero tokens, causing us to 98 // miss diagnosing invalid lines. 99 LexUnexpandedToken(Tmp); 100 101 // There should be no tokens after the directive, but we allow them as an 102 // extension. 103 while (Tmp.is(tok::comment)) // Skip comments in -C mode. 104 LexUnexpandedToken(Tmp); 105 106 if (Tmp.isNot(tok::eom)) { 107 Diag(Tmp, diag::ext_pp_extra_tokens_at_eol) << DirType; 108 DiscardUntilEndOfDirective(); 109 } 110} 111 112 113 114/// SkipExcludedConditionalBlock - We just read a #if or related directive and 115/// decided that the subsequent tokens are in the #if'd out portion of the 116/// file. Lex the rest of the file, until we see an #endif. If 117/// FoundNonSkipPortion is true, then we have already emitted code for part of 118/// this #if directive, so #else/#elif blocks should never be entered. If ElseOk 119/// is true, then #else directives are ok, if not, then we have already seen one 120/// so a #else directive is a duplicate. When this returns, the caller can lex 121/// the first valid token. 122void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc, 123 bool FoundNonSkipPortion, 124 bool FoundElse) { 125 ++NumSkipped; 126 assert(CurTokenLexer == 0 && CurPPLexer && "Lexing a macro, not a file?"); 127 128 CurPPLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false, 129 FoundNonSkipPortion, FoundElse); 130 131 if (CurPTHLexer) { 132 PTHSkipExcludedConditionalBlock(); 133 return; 134 } 135 136 // Enter raw mode to disable identifier lookup (and thus macro expansion), 137 // disabling warnings, etc. 138 CurPPLexer->LexingRawMode = true; 139 Token Tok; 140 while (1) { 141 if (CurLexer) 142 CurLexer->Lex(Tok); 143 else 144 CurPTHLexer->Lex(Tok); 145 146 // If this is the end of the buffer, we have an error. 147 if (Tok.is(tok::eof)) { 148 // Emit errors for each unterminated conditional on the stack, including 149 // the current one. 150 while (!CurPPLexer->ConditionalStack.empty()) { 151 Diag(CurPPLexer->ConditionalStack.back().IfLoc, 152 diag::err_pp_unterminated_conditional); 153 CurPPLexer->ConditionalStack.pop_back(); 154 } 155 156 // Just return and let the caller lex after this #include. 157 break; 158 } 159 160 // If this token is not a preprocessor directive, just skip it. 161 if (Tok.isNot(tok::hash) || !Tok.isAtStartOfLine()) 162 continue; 163 164 // We just parsed a # character at the start of a line, so we're in 165 // directive mode. Tell the lexer this so any newlines we see will be 166 // converted into an EOM token (this terminates the macro). 167 CurPPLexer->ParsingPreprocessorDirective = true; 168 if (CurLexer) CurLexer->SetCommentRetentionState(false); 169 170 171 // Read the next token, the directive flavor. 172 LexUnexpandedToken(Tok); 173 174 // If this isn't an identifier directive (e.g. is "# 1\n" or "#\n", or 175 // something bogus), skip it. 176 if (Tok.isNot(tok::identifier)) { 177 CurPPLexer->ParsingPreprocessorDirective = false; 178 // Restore comment saving mode. 179 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 180 continue; 181 } 182 183 // If the first letter isn't i or e, it isn't intesting to us. We know that 184 // this is safe in the face of spelling differences, because there is no way 185 // to spell an i/e in a strange way that is another letter. Skipping this 186 // allows us to avoid looking up the identifier info for #define/#undef and 187 // other common directives. 188 const char *RawCharData = SourceMgr.getCharacterData(Tok.getLocation()); 189 char FirstChar = RawCharData[0]; 190 if (FirstChar >= 'a' && FirstChar <= 'z' && 191 FirstChar != 'i' && FirstChar != 'e') { 192 CurPPLexer->ParsingPreprocessorDirective = false; 193 // Restore comment saving mode. 194 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 195 continue; 196 } 197 198 // Get the identifier name without trigraphs or embedded newlines. Note 199 // that we can't use Tok.getIdentifierInfo() because its lookup is disabled 200 // when skipping. 201 // TODO: could do this with zero copies in the no-clean case by using 202 // strncmp below. 203 char Directive[20]; 204 unsigned IdLen; 205 if (!Tok.needsCleaning() && Tok.getLength() < 20) { 206 IdLen = Tok.getLength(); 207 memcpy(Directive, RawCharData, IdLen); 208 Directive[IdLen] = 0; 209 } else { 210 std::string DirectiveStr = getSpelling(Tok); 211 IdLen = DirectiveStr.size(); 212 if (IdLen >= 20) { 213 CurPPLexer->ParsingPreprocessorDirective = false; 214 // Restore comment saving mode. 215 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 216 continue; 217 } 218 memcpy(Directive, &DirectiveStr[0], IdLen); 219 Directive[IdLen] = 0; 220 } 221 222 if (FirstChar == 'i' && Directive[1] == 'f') { 223 if ((IdLen == 2) || // "if" 224 (IdLen == 5 && !strcmp(Directive+2, "def")) || // "ifdef" 225 (IdLen == 6 && !strcmp(Directive+2, "ndef"))) { // "ifndef" 226 // We know the entire #if/#ifdef/#ifndef block will be skipped, don't 227 // bother parsing the condition. 228 DiscardUntilEndOfDirective(); 229 CurPPLexer->pushConditionalLevel(Tok.getLocation(), /*wasskipping*/true, 230 /*foundnonskip*/false, 231 /*fnddelse*/false); 232 } 233 } else if (FirstChar == 'e') { 234 if (IdLen == 5 && !strcmp(Directive+1, "ndif")) { // "endif" 235 CheckEndOfDirective("#endif"); 236 PPConditionalInfo CondInfo; 237 CondInfo.WasSkipping = true; // Silence bogus warning. 238 bool InCond = CurPPLexer->popConditionalLevel(CondInfo); 239 InCond = InCond; // Silence warning in no-asserts mode. 240 assert(!InCond && "Can't be skipping if not in a conditional!"); 241 242 // If we popped the outermost skipping block, we're done skipping! 243 if (!CondInfo.WasSkipping) 244 break; 245 } else if (IdLen == 4 && !strcmp(Directive+1, "lse")) { // "else". 246 // #else directive in a skipping conditional. If not in some other 247 // skipping conditional, and if #else hasn't already been seen, enter it 248 // as a non-skipping conditional. 249 CheckEndOfDirective("#else"); 250 PPConditionalInfo &CondInfo = CurPPLexer->peekConditionalLevel(); 251 252 // If this is a #else with a #else before it, report the error. 253 if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_else_after_else); 254 255 // Note that we've seen a #else in this conditional. 256 CondInfo.FoundElse = true; 257 258 // If the conditional is at the top level, and the #if block wasn't 259 // entered, enter the #else block now. 260 if (!CondInfo.WasSkipping && !CondInfo.FoundNonSkip) { 261 CondInfo.FoundNonSkip = true; 262 break; 263 } 264 } else if (IdLen == 4 && !strcmp(Directive+1, "lif")) { // "elif". 265 PPConditionalInfo &CondInfo = CurPPLexer->peekConditionalLevel(); 266 267 bool ShouldEnter; 268 // If this is in a skipping block or if we're already handled this #if 269 // block, don't bother parsing the condition. 270 if (CondInfo.WasSkipping || CondInfo.FoundNonSkip) { 271 DiscardUntilEndOfDirective(); 272 ShouldEnter = false; 273 } else { 274 // Restore the value of LexingRawMode so that identifiers are 275 // looked up, etc, inside the #elif expression. 276 assert(CurPPLexer->LexingRawMode && "We have to be skipping here!"); 277 CurPPLexer->LexingRawMode = false; 278 IdentifierInfo *IfNDefMacro = 0; 279 ShouldEnter = EvaluateDirectiveExpression(IfNDefMacro); 280 CurPPLexer->LexingRawMode = true; 281 } 282 283 // If this is a #elif with a #else before it, report the error. 284 if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_elif_after_else); 285 286 // If this condition is true, enter it! 287 if (ShouldEnter) { 288 CondInfo.FoundNonSkip = true; 289 break; 290 } 291 } 292 } 293 294 CurPPLexer->ParsingPreprocessorDirective = false; 295 // Restore comment saving mode. 296 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 297 } 298 299 // Finally, if we are out of the conditional (saw an #endif or ran off the end 300 // of the file, just stop skipping and return to lexing whatever came after 301 // the #if block. 302 CurPPLexer->LexingRawMode = false; 303} 304 305void Preprocessor::PTHSkipExcludedConditionalBlock() { 306 307 while(1) { 308 assert(CurPTHLexer); 309 assert(CurPTHLexer->LexingRawMode == false); 310 311 // Skip to the next '#else', '#elif', or #endif. 312 if (CurPTHLexer->SkipBlock()) { 313 // We have reached an #endif. Both the '#' and 'endif' tokens 314 // have been consumed by the PTHLexer. Just pop off the condition level. 315 PPConditionalInfo CondInfo; 316 bool InCond = CurPTHLexer->popConditionalLevel(CondInfo); 317 InCond = InCond; // Silence warning in no-asserts mode. 318 assert(!InCond && "Can't be skipping if not in a conditional!"); 319 break; 320 } 321 322 // We have reached a '#else' or '#elif'. Lex the next token to get 323 // the directive flavor. 324 Token Tok; 325 LexUnexpandedToken(Tok); 326 327 // We can actually look up the IdentifierInfo here since we aren't in 328 // raw mode. 329 tok::PPKeywordKind K = Tok.getIdentifierInfo()->getPPKeywordID(); 330 331 if (K == tok::pp_else) { 332 // #else: Enter the else condition. We aren't in a nested condition 333 // since we skip those. We're always in the one matching the last 334 // blocked we skipped. 335 PPConditionalInfo &CondInfo = CurPTHLexer->peekConditionalLevel(); 336 // Note that we've seen a #else in this conditional. 337 CondInfo.FoundElse = true; 338 339 // If the #if block wasn't entered then enter the #else block now. 340 if (!CondInfo.FoundNonSkip) { 341 CondInfo.FoundNonSkip = true; 342 break; 343 } 344 345 // Otherwise skip this block. 346 continue; 347 } 348 349 assert(K == tok::pp_elif); 350 PPConditionalInfo &CondInfo = CurPTHLexer->peekConditionalLevel(); 351 352 // If this is a #elif with a #else before it, report the error. 353 if (CondInfo.FoundElse) 354 Diag(Tok, diag::pp_err_elif_after_else); 355 356 // If this is in a skipping block or if we're already handled this #if 357 // block, don't bother parsing the condition. We just skip this block. 358 if (CondInfo.FoundNonSkip) 359 continue; 360 361 // Evaluate the condition of the #elif. 362 IdentifierInfo *IfNDefMacro = 0; 363 CurPTHLexer->ParsingPreprocessorDirective = true; 364 bool ShouldEnter = EvaluateDirectiveExpression(IfNDefMacro); 365 CurPTHLexer->ParsingPreprocessorDirective = false; 366 367 // If this condition is true, enter it! 368 if (ShouldEnter) { 369 CondInfo.FoundNonSkip = true; 370 break; 371 } 372 373 // Otherwise, skip this block and go to the next one. 374 continue; 375 } 376} 377 378/// LookupFile - Given a "foo" or <foo> reference, look up the indicated file, 379/// return null on failure. isAngled indicates whether the file reference is 380/// for system #include's or not (i.e. using <> instead of ""). 381const FileEntry *Preprocessor::LookupFile(const char *FilenameStart, 382 const char *FilenameEnd, 383 bool isAngled, 384 const DirectoryLookup *FromDir, 385 const DirectoryLookup *&CurDir) { 386 // If the header lookup mechanism may be relative to the current file, pass in 387 // info about where the current file is. 388 const FileEntry *CurFileEnt = 0; 389 if (!FromDir) { 390 unsigned FileID = getCurrentFileLexer()->getFileID(); 391 CurFileEnt = SourceMgr.getFileEntryForID(FileID); 392 } 393 394 // Do a standard file entry lookup. 395 CurDir = CurDirLookup; 396 const FileEntry *FE = 397 HeaderInfo.LookupFile(FilenameStart, FilenameEnd, 398 isAngled, FromDir, CurDir, CurFileEnt); 399 if (FE) return FE; 400 401 // Otherwise, see if this is a subframework header. If so, this is relative 402 // to one of the headers on the #include stack. Walk the list of the current 403 // headers on the #include stack and pass them to HeaderInfo. 404 if (IsFileLexer()) { 405 if ((CurFileEnt = SourceMgr.getFileEntryForID(CurPPLexer->getFileID()))) 406 if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart, FilenameEnd, 407 CurFileEnt))) 408 return FE; 409 } 410 411 for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) { 412 IncludeStackInfo &ISEntry = IncludeMacroStack[e-i-1]; 413 if (IsFileLexer(ISEntry)) { 414 if ((CurFileEnt = 415 SourceMgr.getFileEntryForID(ISEntry.ThePPLexer->getFileID()))) 416 if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart, 417 FilenameEnd, CurFileEnt))) 418 return FE; 419 } 420 } 421 422 // Otherwise, we really couldn't find the file. 423 return 0; 424} 425 426 427//===----------------------------------------------------------------------===// 428// Preprocessor Directive Handling. 429//===----------------------------------------------------------------------===// 430 431/// HandleDirective - This callback is invoked when the lexer sees a # token 432/// at the start of a line. This consumes the directive, modifies the 433/// lexer/preprocessor state, and advances the lexer(s) so that the next token 434/// read is the correct one. 435void Preprocessor::HandleDirective(Token &Result) { 436 // FIXME: Traditional: # with whitespace before it not recognized by K&R? 437 438 // We just parsed a # character at the start of a line, so we're in directive 439 // mode. Tell the lexer this so any newlines we see will be converted into an 440 // EOM token (which terminates the directive). 441 CurPPLexer->ParsingPreprocessorDirective = true; 442 443 ++NumDirectives; 444 445 // We are about to read a token. For the multiple-include optimization FA to 446 // work, we have to remember if we had read any tokens *before* this 447 // pp-directive. 448 bool ReadAnyTokensBeforeDirective = CurPPLexer->MIOpt.getHasReadAnyTokensVal(); 449 450 // Read the next token, the directive flavor. This isn't expanded due to 451 // C99 6.10.3p8. 452 LexUnexpandedToken(Result); 453 454 // C99 6.10.3p11: Is this preprocessor directive in macro invocation? e.g.: 455 // #define A(x) #x 456 // A(abc 457 // #warning blah 458 // def) 459 // If so, the user is relying on non-portable behavior, emit a diagnostic. 460 if (InMacroArgs) 461 Diag(Result, diag::ext_embedded_directive); 462 463TryAgain: 464 switch (Result.getKind()) { 465 case tok::eom: 466 return; // null directive. 467 case tok::comment: 468 // Handle stuff like "# /*foo*/ define X" in -E -C mode. 469 LexUnexpandedToken(Result); 470 goto TryAgain; 471 472 case tok::numeric_constant: 473 // FIXME: implement # 7 line numbers! 474 DiscardUntilEndOfDirective(); 475 return; 476 default: 477 IdentifierInfo *II = Result.getIdentifierInfo(); 478 if (II == 0) break; // Not an identifier. 479 480 // Ask what the preprocessor keyword ID is. 481 switch (II->getPPKeywordID()) { 482 default: break; 483 // C99 6.10.1 - Conditional Inclusion. 484 case tok::pp_if: 485 return HandleIfDirective(Result, ReadAnyTokensBeforeDirective); 486 case tok::pp_ifdef: 487 return HandleIfdefDirective(Result, false, true/*not valid for miopt*/); 488 case tok::pp_ifndef: 489 return HandleIfdefDirective(Result, true, ReadAnyTokensBeforeDirective); 490 case tok::pp_elif: 491 return HandleElifDirective(Result); 492 case tok::pp_else: 493 return HandleElseDirective(Result); 494 case tok::pp_endif: 495 return HandleEndifDirective(Result); 496 497 // C99 6.10.2 - Source File Inclusion. 498 case tok::pp_include: 499 return HandleIncludeDirective(Result); // Handle #include. 500 501 // C99 6.10.3 - Macro Replacement. 502 case tok::pp_define: 503 return HandleDefineDirective(Result); 504 case tok::pp_undef: 505 return HandleUndefDirective(Result); 506 507 // C99 6.10.4 - Line Control. 508 case tok::pp_line: 509 // FIXME: implement #line 510 DiscardUntilEndOfDirective(); 511 return; 512 513 // C99 6.10.5 - Error Directive. 514 case tok::pp_error: 515 return HandleUserDiagnosticDirective(Result, false); 516 517 // C99 6.10.6 - Pragma Directive. 518 case tok::pp_pragma: 519 return HandlePragmaDirective(); 520 521 // GNU Extensions. 522 case tok::pp_import: 523 return HandleImportDirective(Result); 524 case tok::pp_include_next: 525 return HandleIncludeNextDirective(Result); 526 527 case tok::pp_warning: 528 Diag(Result, diag::ext_pp_warning_directive); 529 return HandleUserDiagnosticDirective(Result, true); 530 case tok::pp_ident: 531 return HandleIdentSCCSDirective(Result); 532 case tok::pp_sccs: 533 return HandleIdentSCCSDirective(Result); 534 case tok::pp_assert: 535 //isExtension = true; // FIXME: implement #assert 536 break; 537 case tok::pp_unassert: 538 //isExtension = true; // FIXME: implement #unassert 539 break; 540 } 541 break; 542 } 543 544 // If we reached here, the preprocessing token is not valid! 545 Diag(Result, diag::err_pp_invalid_directive); 546 547 // Read the rest of the PP line. 548 DiscardUntilEndOfDirective(); 549 550 // Okay, we're done parsing the directive. 551} 552 553void Preprocessor::HandleUserDiagnosticDirective(Token &Tok, 554 bool isWarning) { 555 // Read the rest of the line raw. We do this because we don't want macros 556 // to be expanded and we don't require that the tokens be valid preprocessing 557 // tokens. For example, this is allowed: "#warning ` 'foo". GCC does 558 // collapse multiple consequtive white space between tokens, but this isn't 559 // specified by the standard. 560 561 if (CurLexer) { 562 std::string Message = CurLexer->ReadToEndOfLine(); 563 unsigned DiagID = isWarning ? diag::pp_hash_warning : diag::err_pp_hash_error; 564 Diag(Tok, DiagID) << Message; 565 } 566 else { 567 CurPTHLexer->DiscardToEndOfLine(); 568 } 569} 570 571/// HandleIdentSCCSDirective - Handle a #ident/#sccs directive. 572/// 573void Preprocessor::HandleIdentSCCSDirective(Token &Tok) { 574 // Yes, this directive is an extension. 575 Diag(Tok, diag::ext_pp_ident_directive); 576 577 // Read the string argument. 578 Token StrTok; 579 Lex(StrTok); 580 581 // If the token kind isn't a string, it's a malformed directive. 582 if (StrTok.isNot(tok::string_literal) && 583 StrTok.isNot(tok::wide_string_literal)) { 584 Diag(StrTok, diag::err_pp_malformed_ident); 585 return; 586 } 587 588 // Verify that there is nothing after the string, other than EOM. 589 CheckEndOfDirective("#ident"); 590 591 if (Callbacks) 592 Callbacks->Ident(Tok.getLocation(), getSpelling(StrTok)); 593} 594 595//===----------------------------------------------------------------------===// 596// Preprocessor Include Directive Handling. 597//===----------------------------------------------------------------------===// 598 599/// GetIncludeFilenameSpelling - Turn the specified lexer token into a fully 600/// checked and spelled filename, e.g. as an operand of #include. This returns 601/// true if the input filename was in <>'s or false if it were in ""'s. The 602/// caller is expected to provide a buffer that is large enough to hold the 603/// spelling of the filename, but is also expected to handle the case when 604/// this method decides to use a different buffer. 605bool Preprocessor::GetIncludeFilenameSpelling(SourceLocation Loc, 606 const char *&BufStart, 607 const char *&BufEnd) { 608 // Get the text form of the filename. 609 assert(BufStart != BufEnd && "Can't have tokens with empty spellings!"); 610 611 // Make sure the filename is <x> or "x". 612 bool isAngled; 613 if (BufStart[0] == '<') { 614 if (BufEnd[-1] != '>') { 615 Diag(Loc, diag::err_pp_expects_filename); 616 BufStart = 0; 617 return true; 618 } 619 isAngled = true; 620 } else if (BufStart[0] == '"') { 621 if (BufEnd[-1] != '"') { 622 Diag(Loc, diag::err_pp_expects_filename); 623 BufStart = 0; 624 return true; 625 } 626 isAngled = false; 627 } else { 628 Diag(Loc, diag::err_pp_expects_filename); 629 BufStart = 0; 630 return true; 631 } 632 633 // Diagnose #include "" as invalid. 634 if (BufEnd-BufStart <= 2) { 635 Diag(Loc, diag::err_pp_empty_filename); 636 BufStart = 0; 637 return ""; 638 } 639 640 // Skip the brackets. 641 ++BufStart; 642 --BufEnd; 643 return isAngled; 644} 645 646/// ConcatenateIncludeName - Handle cases where the #include name is expanded 647/// from a macro as multiple tokens, which need to be glued together. This 648/// occurs for code like: 649/// #define FOO <a/b.h> 650/// #include FOO 651/// because in this case, "<a/b.h>" is returned as 7 tokens, not one. 652/// 653/// This code concatenates and consumes tokens up to the '>' token. It returns 654/// false if the > was found, otherwise it returns true if it finds and consumes 655/// the EOM marker. 656static bool ConcatenateIncludeName(llvm::SmallVector<char, 128> &FilenameBuffer, 657 Preprocessor &PP) { 658 Token CurTok; 659 660 PP.Lex(CurTok); 661 while (CurTok.isNot(tok::eom)) { 662 // Append the spelling of this token to the buffer. If there was a space 663 // before it, add it now. 664 if (CurTok.hasLeadingSpace()) 665 FilenameBuffer.push_back(' '); 666 667 // Get the spelling of the token, directly into FilenameBuffer if possible. 668 unsigned PreAppendSize = FilenameBuffer.size(); 669 FilenameBuffer.resize(PreAppendSize+CurTok.getLength()); 670 671 const char *BufPtr = &FilenameBuffer[PreAppendSize]; 672 unsigned ActualLen = PP.getSpelling(CurTok, BufPtr); 673 674 // If the token was spelled somewhere else, copy it into FilenameBuffer. 675 if (BufPtr != &FilenameBuffer[PreAppendSize]) 676 memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen); 677 678 // Resize FilenameBuffer to the correct size. 679 if (CurTok.getLength() != ActualLen) 680 FilenameBuffer.resize(PreAppendSize+ActualLen); 681 682 // If we found the '>' marker, return success. 683 if (CurTok.is(tok::greater)) 684 return false; 685 686 PP.Lex(CurTok); 687 } 688 689 // If we hit the eom marker, emit an error and return true so that the caller 690 // knows the EOM has been read. 691 PP.Diag(CurTok.getLocation(), diag::err_pp_expects_filename); 692 return true; 693} 694 695/// HandleIncludeDirective - The "#include" tokens have just been read, read the 696/// file to be included from the lexer, then include it! This is a common 697/// routine with functionality shared between #include, #include_next and 698/// #import. LookupFrom is set when this is a #include_next directive, it 699/// specifies the file to start searching from. 700void Preprocessor::HandleIncludeDirective(Token &IncludeTok, 701 const DirectoryLookup *LookupFrom, 702 bool isImport) { 703 704 Token FilenameTok; 705 CurPPLexer->LexIncludeFilename(FilenameTok); 706 707 // Reserve a buffer to get the spelling. 708 llvm::SmallVector<char, 128> FilenameBuffer; 709 const char *FilenameStart, *FilenameEnd; 710 711 switch (FilenameTok.getKind()) { 712 case tok::eom: 713 // If the token kind is EOM, the error has already been diagnosed. 714 return; 715 716 case tok::angle_string_literal: 717 case tok::string_literal: { 718 FilenameBuffer.resize(FilenameTok.getLength()); 719 FilenameStart = &FilenameBuffer[0]; 720 unsigned Len = getSpelling(FilenameTok, FilenameStart); 721 FilenameEnd = FilenameStart+Len; 722 break; 723 } 724 725 case tok::less: 726 // This could be a <foo/bar.h> file coming from a macro expansion. In this 727 // case, glue the tokens together into FilenameBuffer and interpret those. 728 FilenameBuffer.push_back('<'); 729 if (ConcatenateIncludeName(FilenameBuffer, *this)) 730 return; // Found <eom> but no ">"? Diagnostic already emitted. 731 FilenameStart = &FilenameBuffer[0]; 732 FilenameEnd = &FilenameBuffer[FilenameBuffer.size()]; 733 break; 734 default: 735 Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename); 736 DiscardUntilEndOfDirective(); 737 return; 738 } 739 740 bool isAngled = GetIncludeFilenameSpelling(FilenameTok.getLocation(), 741 FilenameStart, FilenameEnd); 742 // If GetIncludeFilenameSpelling set the start ptr to null, there was an 743 // error. 744 if (FilenameStart == 0) { 745 DiscardUntilEndOfDirective(); 746 return; 747 } 748 749 // Verify that there is nothing after the filename, other than EOM. Use the 750 // preprocessor to lex this in case lexing the filename entered a macro. 751 CheckEndOfDirective("#include"); 752 753 // Check that we don't have infinite #include recursion. 754 if (IncludeMacroStack.size() == MaxAllowedIncludeStackDepth-1) { 755 Diag(FilenameTok, diag::err_pp_include_too_deep); 756 return; 757 } 758 759 // Search include directories. 760 const DirectoryLookup *CurDir; 761 const FileEntry *File = LookupFile(FilenameStart, FilenameEnd, 762 isAngled, LookupFrom, CurDir); 763 if (File == 0) { 764 Diag(FilenameTok, diag::err_pp_file_not_found) 765 << std::string(FilenameStart, FilenameEnd); 766 return; 767 } 768 769 // Ask HeaderInfo if we should enter this #include file. If not, #including 770 // this file will have no effect. 771 if (!HeaderInfo.ShouldEnterIncludeFile(File, isImport)) 772 return; 773 774 // The #included file will be considered to be a system header if either it is 775 // in a system include directory, or if the #includer is a system include 776 // header. 777 SrcMgr::CharacteristicKind FileCharacter = 778 std::max(HeaderInfo.getFileDirFlavor(File), 779 SourceMgr.getFileCharacteristic(getCurrentFileLexer()->getFileID())); 780 781 // Look up the file, create a File ID for it. 782 unsigned FileID = SourceMgr.createFileID(File, FilenameTok.getLocation(), 783 FileCharacter); 784 if (FileID == 0) { 785 Diag(FilenameTok, diag::err_pp_file_not_found) 786 << std::string(FilenameStart, FilenameEnd); 787 return; 788 } 789 790 // Finally, if all is good, enter the new file! 791 EnterSourceFile(FileID, CurDir); 792} 793 794/// HandleIncludeNextDirective - Implements #include_next. 795/// 796void Preprocessor::HandleIncludeNextDirective(Token &IncludeNextTok) { 797 Diag(IncludeNextTok, diag::ext_pp_include_next_directive); 798 799 // #include_next is like #include, except that we start searching after 800 // the current found directory. If we can't do this, issue a 801 // diagnostic. 802 const DirectoryLookup *Lookup = CurDirLookup; 803 if (isInPrimaryFile()) { 804 Lookup = 0; 805 Diag(IncludeNextTok, diag::pp_include_next_in_primary); 806 } else if (Lookup == 0) { 807 Diag(IncludeNextTok, diag::pp_include_next_absolute_path); 808 } else { 809 // Start looking up in the next directory. 810 ++Lookup; 811 } 812 813 return HandleIncludeDirective(IncludeNextTok, Lookup); 814} 815 816/// HandleImportDirective - Implements #import. 817/// 818void Preprocessor::HandleImportDirective(Token &ImportTok) { 819 Diag(ImportTok, diag::ext_pp_import_directive); 820 821 return HandleIncludeDirective(ImportTok, 0, true); 822} 823 824//===----------------------------------------------------------------------===// 825// Preprocessor Macro Directive Handling. 826//===----------------------------------------------------------------------===// 827 828/// ReadMacroDefinitionArgList - The ( starting an argument list of a macro 829/// definition has just been read. Lex the rest of the arguments and the 830/// closing ), updating MI with what we learn. Return true if an error occurs 831/// parsing the arg list. 832bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI) { 833 llvm::SmallVector<IdentifierInfo*, 32> Arguments; 834 835 Token Tok; 836 while (1) { 837 LexUnexpandedToken(Tok); 838 switch (Tok.getKind()) { 839 case tok::r_paren: 840 // Found the end of the argument list. 841 if (Arguments.empty()) { // #define FOO() 842 MI->setArgumentList(Arguments.begin(), Arguments.end()); 843 return false; 844 } 845 // Otherwise we have #define FOO(A,) 846 Diag(Tok, diag::err_pp_expected_ident_in_arg_list); 847 return true; 848 case tok::ellipsis: // #define X(... -> C99 varargs 849 // Warn if use of C99 feature in non-C99 mode. 850 if (!Features.C99) Diag(Tok, diag::ext_variadic_macro); 851 852 // Lex the token after the identifier. 853 LexUnexpandedToken(Tok); 854 if (Tok.isNot(tok::r_paren)) { 855 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 856 return true; 857 } 858 // Add the __VA_ARGS__ identifier as an argument. 859 Arguments.push_back(Ident__VA_ARGS__); 860 MI->setIsC99Varargs(); 861 MI->setArgumentList(Arguments.begin(), Arguments.end()); 862 return false; 863 case tok::eom: // #define X( 864 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 865 return true; 866 default: 867 // Handle keywords and identifiers here to accept things like 868 // #define Foo(for) for. 869 IdentifierInfo *II = Tok.getIdentifierInfo(); 870 if (II == 0) { 871 // #define X(1 872 Diag(Tok, diag::err_pp_invalid_tok_in_arg_list); 873 return true; 874 } 875 876 // If this is already used as an argument, it is used multiple times (e.g. 877 // #define X(A,A. 878 if (std::find(Arguments.begin(), Arguments.end(), II) != 879 Arguments.end()) { // C99 6.10.3p6 880 Diag(Tok, diag::err_pp_duplicate_name_in_arg_list) << II; 881 return true; 882 } 883 884 // Add the argument to the macro info. 885 Arguments.push_back(II); 886 887 // Lex the token after the identifier. 888 LexUnexpandedToken(Tok); 889 890 switch (Tok.getKind()) { 891 default: // #define X(A B 892 Diag(Tok, diag::err_pp_expected_comma_in_arg_list); 893 return true; 894 case tok::r_paren: // #define X(A) 895 MI->setArgumentList(Arguments.begin(), Arguments.end()); 896 return false; 897 case tok::comma: // #define X(A, 898 break; 899 case tok::ellipsis: // #define X(A... -> GCC extension 900 // Diagnose extension. 901 Diag(Tok, diag::ext_named_variadic_macro); 902 903 // Lex the token after the identifier. 904 LexUnexpandedToken(Tok); 905 if (Tok.isNot(tok::r_paren)) { 906 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 907 return true; 908 } 909 910 MI->setIsGNUVarargs(); 911 MI->setArgumentList(Arguments.begin(), Arguments.end()); 912 return false; 913 } 914 } 915 } 916} 917 918/// HandleDefineDirective - Implements #define. This consumes the entire macro 919/// line then lets the caller lex the next real token. 920void Preprocessor::HandleDefineDirective(Token &DefineTok) { 921 ++NumDefined; 922 923 Token MacroNameTok; 924 ReadMacroName(MacroNameTok, 1); 925 926 // Error reading macro name? If so, diagnostic already issued. 927 if (MacroNameTok.is(tok::eom)) 928 return; 929 930 // If we are supposed to keep comments in #defines, reenable comment saving 931 // mode. 932 if (CurLexer) CurLexer->SetCommentRetentionState(KeepMacroComments); 933 934 // Create the new macro. 935 MacroInfo *MI = AllocateMacroInfo(MacroNameTok.getLocation()); 936 937 Token Tok; 938 LexUnexpandedToken(Tok); 939 940 // If this is a function-like macro definition, parse the argument list, 941 // marking each of the identifiers as being used as macro arguments. Also, 942 // check other constraints on the first token of the macro body. 943 if (Tok.is(tok::eom)) { 944 // If there is no body to this macro, we have no special handling here. 945 } else if (Tok.is(tok::l_paren) && !Tok.hasLeadingSpace()) { 946 // This is a function-like macro definition. Read the argument list. 947 MI->setIsFunctionLike(); 948 if (ReadMacroDefinitionArgList(MI)) { 949 // Forget about MI. 950 ReleaseMacroInfo(MI); 951 // Throw away the rest of the line. 952 if (CurPPLexer->ParsingPreprocessorDirective) 953 DiscardUntilEndOfDirective(); 954 return; 955 } 956 957 // Read the first token after the arg list for down below. 958 LexUnexpandedToken(Tok); 959 } else if (!Tok.hasLeadingSpace()) { 960 // C99 requires whitespace between the macro definition and the body. Emit 961 // a diagnostic for something like "#define X+". 962 if (Features.C99) { 963 Diag(Tok, diag::ext_c99_whitespace_required_after_macro_name); 964 } else { 965 // FIXME: C90/C++ do not get this diagnostic, but it does get a similar 966 // one in some cases! 967 } 968 } else { 969 // This is a normal token with leading space. Clear the leading space 970 // marker on the first token to get proper expansion. 971 Tok.clearFlag(Token::LeadingSpace); 972 } 973 974 // If this is a definition of a variadic C99 function-like macro, not using 975 // the GNU named varargs extension, enabled __VA_ARGS__. 976 977 // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro. 978 // This gets unpoisoned where it is allowed. 979 assert(Ident__VA_ARGS__->isPoisoned() && "__VA_ARGS__ should be poisoned!"); 980 if (MI->isC99Varargs()) 981 Ident__VA_ARGS__->setIsPoisoned(false); 982 983 // Read the rest of the macro body. 984 if (MI->isObjectLike()) { 985 // Object-like macros are very simple, just read their body. 986 while (Tok.isNot(tok::eom)) { 987 MI->AddTokenToBody(Tok); 988 // Get the next token of the macro. 989 LexUnexpandedToken(Tok); 990 } 991 992 } else { 993 // Otherwise, read the body of a function-like macro. This has to validate 994 // the # (stringize) operator. 995 while (Tok.isNot(tok::eom)) { 996 MI->AddTokenToBody(Tok); 997 998 // Check C99 6.10.3.2p1: ensure that # operators are followed by macro 999 // parameters in function-like macro expansions. 1000 if (Tok.isNot(tok::hash)) { 1001 // Get the next token of the macro. 1002 LexUnexpandedToken(Tok); 1003 continue; 1004 } 1005 1006 // Get the next token of the macro. 1007 LexUnexpandedToken(Tok); 1008 1009 // Not a macro arg identifier? 1010 if (!Tok.getIdentifierInfo() || 1011 MI->getArgumentNum(Tok.getIdentifierInfo()) == -1) { 1012 Diag(Tok, diag::err_pp_stringize_not_parameter); 1013 ReleaseMacroInfo(MI); 1014 1015 // Disable __VA_ARGS__ again. 1016 Ident__VA_ARGS__->setIsPoisoned(true); 1017 return; 1018 } 1019 1020 // Things look ok, add the param name token to the macro. 1021 MI->AddTokenToBody(Tok); 1022 1023 // Get the next token of the macro. 1024 LexUnexpandedToken(Tok); 1025 } 1026 } 1027 1028 1029 // Disable __VA_ARGS__ again. 1030 Ident__VA_ARGS__->setIsPoisoned(true); 1031 1032 // Check that there is no paste (##) operator at the begining or end of the 1033 // replacement list. 1034 unsigned NumTokens = MI->getNumTokens(); 1035 if (NumTokens != 0) { 1036 if (MI->getReplacementToken(0).is(tok::hashhash)) { 1037 Diag(MI->getReplacementToken(0), diag::err_paste_at_start); 1038 ReleaseMacroInfo(MI); 1039 return; 1040 } 1041 if (MI->getReplacementToken(NumTokens-1).is(tok::hashhash)) { 1042 Diag(MI->getReplacementToken(NumTokens-1), diag::err_paste_at_end); 1043 ReleaseMacroInfo(MI); 1044 return; 1045 } 1046 } 1047 1048 // If this is the primary source file, remember that this macro hasn't been 1049 // used yet. 1050 if (isInPrimaryFile()) 1051 MI->setIsUsed(false); 1052 1053 // Finally, if this identifier already had a macro defined for it, verify that 1054 // the macro bodies are identical and free the old definition. 1055 if (MacroInfo *OtherMI = getMacroInfo(MacroNameTok.getIdentifierInfo())) { 1056 if (!OtherMI->isUsed()) 1057 Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used); 1058 1059 // Macros must be identical. This means all tokes and whitespace separation 1060 // must be the same. C99 6.10.3.2. 1061 if (!MI->isIdenticalTo(*OtherMI, *this)) { 1062 Diag(MI->getDefinitionLoc(), diag::ext_pp_macro_redef) 1063 << MacroNameTok.getIdentifierInfo(); 1064 Diag(OtherMI->getDefinitionLoc(), diag::note_previous_definition); 1065 } 1066 ReleaseMacroInfo(OtherMI); 1067 } 1068 1069 setMacroInfo(MacroNameTok.getIdentifierInfo(), MI); 1070} 1071 1072/// HandleUndefDirective - Implements #undef. 1073/// 1074void Preprocessor::HandleUndefDirective(Token &UndefTok) { 1075 ++NumUndefined; 1076 1077 Token MacroNameTok; 1078 ReadMacroName(MacroNameTok, 2); 1079 1080 // Error reading macro name? If so, diagnostic already issued. 1081 if (MacroNameTok.is(tok::eom)) 1082 return; 1083 1084 // Check to see if this is the last token on the #undef line. 1085 CheckEndOfDirective("#undef"); 1086 1087 // Okay, we finally have a valid identifier to undef. 1088 MacroInfo *MI = getMacroInfo(MacroNameTok.getIdentifierInfo()); 1089 1090 // If the macro is not defined, this is a noop undef, just return. 1091 if (MI == 0) return; 1092 1093 if (!MI->isUsed()) 1094 Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used); 1095 1096 // Free macro definition. 1097 ReleaseMacroInfo(MI); 1098 setMacroInfo(MacroNameTok.getIdentifierInfo(), 0); 1099} 1100 1101 1102//===----------------------------------------------------------------------===// 1103// Preprocessor Conditional Directive Handling. 1104//===----------------------------------------------------------------------===// 1105 1106/// HandleIfdefDirective - Implements the #ifdef/#ifndef directive. isIfndef is 1107/// true when this is a #ifndef directive. ReadAnyTokensBeforeDirective is true 1108/// if any tokens have been returned or pp-directives activated before this 1109/// #ifndef has been lexed. 1110/// 1111void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef, 1112 bool ReadAnyTokensBeforeDirective) { 1113 ++NumIf; 1114 Token DirectiveTok = Result; 1115 1116 Token MacroNameTok; 1117 ReadMacroName(MacroNameTok); 1118 1119 // Error reading macro name? If so, diagnostic already issued. 1120 if (MacroNameTok.is(tok::eom)) { 1121 // Skip code until we get to #endif. This helps with recovery by not 1122 // emitting an error when the #endif is reached. 1123 SkipExcludedConditionalBlock(DirectiveTok.getLocation(), 1124 /*Foundnonskip*/false, /*FoundElse*/false); 1125 return; 1126 } 1127 1128 // Check to see if this is the last token on the #if[n]def line. 1129 CheckEndOfDirective(isIfndef ? "#ifndef" : "#ifdef"); 1130 1131 if (CurPPLexer->getConditionalStackDepth() == 0) { 1132 // If the start of a top-level #ifdef, inform MIOpt. 1133 if (!ReadAnyTokensBeforeDirective) { 1134 assert(isIfndef && "#ifdef shouldn't reach here"); 1135 CurPPLexer->MIOpt.EnterTopLevelIFNDEF(MacroNameTok.getIdentifierInfo()); 1136 } else 1137 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1138 } 1139 1140 IdentifierInfo *MII = MacroNameTok.getIdentifierInfo(); 1141 MacroInfo *MI = getMacroInfo(MII); 1142 1143 // If there is a macro, process it. 1144 if (MI) // Mark it used. 1145 MI->setIsUsed(true); 1146 1147 // Should we include the stuff contained by this directive? 1148 if (!MI == isIfndef) { 1149 // Yes, remember that we are inside a conditional, then lex the next token. 1150 CurPPLexer->pushConditionalLevel(DirectiveTok.getLocation(), /*wasskip*/false, 1151 /*foundnonskip*/true, /*foundelse*/false); 1152 } else { 1153 // No, skip the contents of this block and return the first token after it. 1154 SkipExcludedConditionalBlock(DirectiveTok.getLocation(), 1155 /*Foundnonskip*/false, 1156 /*FoundElse*/false); 1157 } 1158} 1159 1160/// HandleIfDirective - Implements the #if directive. 1161/// 1162void Preprocessor::HandleIfDirective(Token &IfToken, 1163 bool ReadAnyTokensBeforeDirective) { 1164 ++NumIf; 1165 1166 // Parse and evaluation the conditional expression. 1167 IdentifierInfo *IfNDefMacro = 0; 1168 bool ConditionalTrue = EvaluateDirectiveExpression(IfNDefMacro); 1169 1170 1171 // If this condition is equivalent to #ifndef X, and if this is the first 1172 // directive seen, handle it for the multiple-include optimization. 1173 if (CurPPLexer->getConditionalStackDepth() == 0) { 1174 if (!ReadAnyTokensBeforeDirective && IfNDefMacro) 1175 CurPPLexer->MIOpt.EnterTopLevelIFNDEF(IfNDefMacro); 1176 else 1177 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1178 } 1179 1180 // Should we include the stuff contained by this directive? 1181 if (ConditionalTrue) { 1182 // Yes, remember that we are inside a conditional, then lex the next token. 1183 CurPPLexer->pushConditionalLevel(IfToken.getLocation(), /*wasskip*/false, 1184 /*foundnonskip*/true, /*foundelse*/false); 1185 } else { 1186 // No, skip the contents of this block and return the first token after it. 1187 SkipExcludedConditionalBlock(IfToken.getLocation(), /*Foundnonskip*/false, 1188 /*FoundElse*/false); 1189 } 1190} 1191 1192/// HandleEndifDirective - Implements the #endif directive. 1193/// 1194void Preprocessor::HandleEndifDirective(Token &EndifToken) { 1195 ++NumEndif; 1196 1197 // Check that this is the whole directive. 1198 CheckEndOfDirective("#endif"); 1199 1200 PPConditionalInfo CondInfo; 1201 if (CurPPLexer->popConditionalLevel(CondInfo)) { 1202 // No conditionals on the stack: this is an #endif without an #if. 1203 Diag(EndifToken, diag::err_pp_endif_without_if); 1204 return; 1205 } 1206 1207 // If this the end of a top-level #endif, inform MIOpt. 1208 if (CurPPLexer->getConditionalStackDepth() == 0) 1209 CurPPLexer->MIOpt.ExitTopLevelConditional(); 1210 1211 assert(!CondInfo.WasSkipping && !CurPPLexer->LexingRawMode && 1212 "This code should only be reachable in the non-skipping case!"); 1213} 1214 1215 1216void Preprocessor::HandleElseDirective(Token &Result) { 1217 ++NumElse; 1218 1219 // #else directive in a non-skipping conditional... start skipping. 1220 CheckEndOfDirective("#else"); 1221 1222 PPConditionalInfo CI; 1223 if (CurPPLexer->popConditionalLevel(CI)) { 1224 Diag(Result, diag::pp_err_else_without_if); 1225 return; 1226 } 1227 1228 // If this is a top-level #else, inform the MIOpt. 1229 if (CurPPLexer->getConditionalStackDepth() == 0) 1230 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1231 1232 // If this is a #else with a #else before it, report the error. 1233 if (CI.FoundElse) Diag(Result, diag::pp_err_else_after_else); 1234 1235 // Finally, skip the rest of the contents of this block and return the first 1236 // token after it. 1237 return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true, 1238 /*FoundElse*/true); 1239} 1240 1241void Preprocessor::HandleElifDirective(Token &ElifToken) { 1242 ++NumElse; 1243 1244 // #elif directive in a non-skipping conditional... start skipping. 1245 // We don't care what the condition is, because we will always skip it (since 1246 // the block immediately before it was included). 1247 DiscardUntilEndOfDirective(); 1248 1249 PPConditionalInfo CI; 1250 if (CurPPLexer->popConditionalLevel(CI)) { 1251 Diag(ElifToken, diag::pp_err_elif_without_if); 1252 return; 1253 } 1254 1255 // If this is a top-level #elif, inform the MIOpt. 1256 if (CurPPLexer->getConditionalStackDepth() == 0) 1257 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1258 1259 // If this is a #elif with a #else before it, report the error. 1260 if (CI.FoundElse) Diag(ElifToken, diag::pp_err_elif_after_else); 1261 1262 // Finally, skip the rest of the contents of this block and return the first 1263 // token after it. 1264 return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true, 1265 /*FoundElse*/CI.FoundElse); 1266} 1267 1268