PPDirectives.cpp revision 2df37b8eaecc5382e0e511a738f88918f48d9454
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 25/// DiscardUntilEndOfDirective - Read and discard all tokens remaining on the 26/// current line until the tok::eom token is found. 27void Preprocessor::DiscardUntilEndOfDirective() { 28 Token Tmp; 29 do { 30 LexUnexpandedToken(Tmp); 31 } while (Tmp.isNot(tok::eom)); 32} 33 34/// isCXXNamedOperator - Returns "true" if the token is a named operator in C++. 35static bool isCXXNamedOperator(const std::string &Spelling) { 36 return Spelling == "and" || Spelling == "bitand" || Spelling == "bitor" || 37 Spelling == "compl" || Spelling == "not" || Spelling == "not_eq" || 38 Spelling == "or" || Spelling == "xor"; 39} 40 41/// ReadMacroName - Lex and validate a macro name, which occurs after a 42/// #define or #undef. This sets the token kind to eom and discards the rest 43/// of the macro line if the macro name is invalid. isDefineUndef is 1 if 44/// this is due to a a #define, 2 if #undef directive, 0 if it is something 45/// else (e.g. #ifdef). 46void Preprocessor::ReadMacroName(Token &MacroNameTok, char isDefineUndef) { 47 // Read the token, don't allow macro expansion on it. 48 LexUnexpandedToken(MacroNameTok); 49 50 // Missing macro name? 51 if (MacroNameTok.is(tok::eom)) { 52 Diag(MacroNameTok, diag::err_pp_missing_macro_name); 53 return; 54 } 55 56 IdentifierInfo *II = MacroNameTok.getIdentifierInfo(); 57 if (II == 0) { 58 std::string Spelling = getSpelling(MacroNameTok); 59 if (isCXXNamedOperator(Spelling)) 60 // C++ 2.5p2: Alternative tokens behave the same as its primary token 61 // except for their spellings. 62 Diag(MacroNameTok, diag::err_pp_operator_used_as_macro_name) << Spelling; 63 else 64 Diag(MacroNameTok, diag::err_pp_macro_not_identifier); 65 // Fall through on error. 66 } else if (isDefineUndef && II->getPPKeywordID() == tok::pp_defined) { 67 // Error if defining "defined": C99 6.10.8.4. 68 Diag(MacroNameTok, diag::err_defined_macro_name); 69 } else if (isDefineUndef && II->hasMacroDefinition() && 70 getMacroInfo(II)->isBuiltinMacro()) { 71 // Error if defining "__LINE__" and other builtins: C99 6.10.8.4. 72 if (isDefineUndef == 1) 73 Diag(MacroNameTok, diag::pp_redef_builtin_macro); 74 else 75 Diag(MacroNameTok, diag::pp_undef_builtin_macro); 76 } else { 77 // Okay, we got a good identifier node. Return it. 78 return; 79 } 80 81 // Invalid macro name, read and discard the rest of the line. Then set the 82 // token kind to tok::eom. 83 MacroNameTok.setKind(tok::eom); 84 return DiscardUntilEndOfDirective(); 85} 86 87/// CheckEndOfDirective - Ensure that the next token is a tok::eom token. If 88/// not, emit a diagnostic and consume up until the eom. 89void Preprocessor::CheckEndOfDirective(const char *DirType) { 90 Token Tmp; 91 // Lex unexpanded tokens: macros might expand to zero tokens, causing us to 92 // miss diagnosing invalid lines. 93 LexUnexpandedToken(Tmp); 94 95 // There should be no tokens after the directive, but we allow them as an 96 // extension. 97 while (Tmp.is(tok::comment)) // Skip comments in -C mode. 98 LexUnexpandedToken(Tmp); 99 100 if (Tmp.isNot(tok::eom)) { 101 Diag(Tmp, diag::ext_pp_extra_tokens_at_eol) << DirType; 102 DiscardUntilEndOfDirective(); 103 } 104} 105 106 107 108/// SkipExcludedConditionalBlock - We just read a #if or related directive and 109/// decided that the subsequent tokens are in the #if'd out portion of the 110/// file. Lex the rest of the file, until we see an #endif. If 111/// FoundNonSkipPortion is true, then we have already emitted code for part of 112/// this #if directive, so #else/#elif blocks should never be entered. If ElseOk 113/// is true, then #else directives are ok, if not, then we have already seen one 114/// so a #else directive is a duplicate. When this returns, the caller can lex 115/// the first valid token. 116void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc, 117 bool FoundNonSkipPortion, 118 bool FoundElse) { 119 ++NumSkipped; 120 assert(CurTokenLexer == 0 && CurPPLexer && "Lexing a macro, not a file?"); 121 122 CurPPLexer->pushConditionalLevel(IfTokenLoc, /*isSkipping*/false, 123 FoundNonSkipPortion, FoundElse); 124 125 // Enter raw mode to disable identifier lookup (and thus macro expansion), 126 // disabling warnings, etc. 127 CurPPLexer->LexingRawMode = true; 128 Token Tok; 129 while (1) { 130 if (CurLexer) 131 CurLexer->Lex(Tok); 132 else 133 CurPTHLexer->Lex(Tok); 134 135 // If this is the end of the buffer, we have an error. 136 if (Tok.is(tok::eof)) { 137 // Emit errors for each unterminated conditional on the stack, including 138 // the current one. 139 while (!CurPPLexer->ConditionalStack.empty()) { 140 Diag(CurPPLexer->ConditionalStack.back().IfLoc, 141 diag::err_pp_unterminated_conditional); 142 CurPPLexer->ConditionalStack.pop_back(); 143 } 144 145 // Just return and let the caller lex after this #include. 146 break; 147 } 148 149 // If this token is not a preprocessor directive, just skip it. 150 if (Tok.isNot(tok::hash) || !Tok.isAtStartOfLine()) 151 continue; 152 153 // We just parsed a # character at the start of a line, so we're in 154 // directive mode. Tell the lexer this so any newlines we see will be 155 // converted into an EOM token (this terminates the macro). 156 CurPPLexer->ParsingPreprocessorDirective = true; 157 if (CurLexer) CurLexer->SetCommentRetentionState(false); 158 159 160 // Read the next token, the directive flavor. 161 LexUnexpandedToken(Tok); 162 163 // If this isn't an identifier directive (e.g. is "# 1\n" or "#\n", or 164 // something bogus), skip it. 165 if (Tok.isNot(tok::identifier)) { 166 CurPPLexer->ParsingPreprocessorDirective = false; 167 // Restore comment saving mode. 168 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 169 continue; 170 } 171 172 // If the first letter isn't i or e, it isn't intesting to us. We know that 173 // this is safe in the face of spelling differences, because there is no way 174 // to spell an i/e in a strange way that is another letter. Skipping this 175 // allows us to avoid looking up the identifier info for #define/#undef and 176 // other common directives. 177 const char *RawCharData = SourceMgr.getCharacterData(Tok.getLocation()); 178 char FirstChar = RawCharData[0]; 179 if (FirstChar >= 'a' && FirstChar <= 'z' && 180 FirstChar != 'i' && FirstChar != 'e') { 181 CurPPLexer->ParsingPreprocessorDirective = false; 182 // Restore comment saving mode. 183 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 184 continue; 185 } 186 187 // Get the identifier name without trigraphs or embedded newlines. Note 188 // that we can't use Tok.getIdentifierInfo() because its lookup is disabled 189 // when skipping. 190 // TODO: could do this with zero copies in the no-clean case by using 191 // strncmp below. 192 char Directive[20]; 193 unsigned IdLen; 194 if (!Tok.needsCleaning() && Tok.getLength() < 20) { 195 IdLen = Tok.getLength(); 196 memcpy(Directive, RawCharData, IdLen); 197 Directive[IdLen] = 0; 198 } else { 199 std::string DirectiveStr = getSpelling(Tok); 200 IdLen = DirectiveStr.size(); 201 if (IdLen >= 20) { 202 CurPPLexer->ParsingPreprocessorDirective = false; 203 // Restore comment saving mode. 204 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 205 continue; 206 } 207 memcpy(Directive, &DirectiveStr[0], IdLen); 208 Directive[IdLen] = 0; 209 } 210 211 if (FirstChar == 'i' && Directive[1] == 'f') { 212 if ((IdLen == 2) || // "if" 213 (IdLen == 5 && !strcmp(Directive+2, "def")) || // "ifdef" 214 (IdLen == 6 && !strcmp(Directive+2, "ndef"))) { // "ifndef" 215 // We know the entire #if/#ifdef/#ifndef block will be skipped, don't 216 // bother parsing the condition. 217 DiscardUntilEndOfDirective(); 218 CurPPLexer->pushConditionalLevel(Tok.getLocation(), /*wasskipping*/true, 219 /*foundnonskip*/false, 220 /*fnddelse*/false); 221 } 222 } else if (FirstChar == 'e') { 223 if (IdLen == 5 && !strcmp(Directive+1, "ndif")) { // "endif" 224 CheckEndOfDirective("#endif"); 225 PPConditionalInfo CondInfo; 226 CondInfo.WasSkipping = true; // Silence bogus warning. 227 bool InCond = CurPPLexer->popConditionalLevel(CondInfo); 228 InCond = InCond; // Silence warning in no-asserts mode. 229 assert(!InCond && "Can't be skipping if not in a conditional!"); 230 231 // If we popped the outermost skipping block, we're done skipping! 232 if (!CondInfo.WasSkipping) 233 break; 234 } else if (IdLen == 4 && !strcmp(Directive+1, "lse")) { // "else". 235 // #else directive in a skipping conditional. If not in some other 236 // skipping conditional, and if #else hasn't already been seen, enter it 237 // as a non-skipping conditional. 238 CheckEndOfDirective("#else"); 239 PPConditionalInfo &CondInfo = CurPPLexer->peekConditionalLevel(); 240 241 // If this is a #else with a #else before it, report the error. 242 if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_else_after_else); 243 244 // Note that we've seen a #else in this conditional. 245 CondInfo.FoundElse = true; 246 247 // If the conditional is at the top level, and the #if block wasn't 248 // entered, enter the #else block now. 249 if (!CondInfo.WasSkipping && !CondInfo.FoundNonSkip) { 250 CondInfo.FoundNonSkip = true; 251 break; 252 } 253 } else if (IdLen == 4 && !strcmp(Directive+1, "lif")) { // "elif". 254 PPConditionalInfo &CondInfo = CurPPLexer->peekConditionalLevel(); 255 256 bool ShouldEnter; 257 // If this is in a skipping block or if we're already handled this #if 258 // block, don't bother parsing the condition. 259 if (CondInfo.WasSkipping || CondInfo.FoundNonSkip) { 260 DiscardUntilEndOfDirective(); 261 ShouldEnter = false; 262 } else { 263 // Restore the value of LexingRawMode so that identifiers are 264 // looked up, etc, inside the #elif expression. 265 assert(CurPPLexer->LexingRawMode && "We have to be skipping here!"); 266 CurPPLexer->LexingRawMode = false; 267 IdentifierInfo *IfNDefMacro = 0; 268 ShouldEnter = EvaluateDirectiveExpression(IfNDefMacro); 269 CurPPLexer->LexingRawMode = true; 270 } 271 272 // If this is a #elif with a #else before it, report the error. 273 if (CondInfo.FoundElse) Diag(Tok, diag::pp_err_elif_after_else); 274 275 // If this condition is true, enter it! 276 if (ShouldEnter) { 277 CondInfo.FoundNonSkip = true; 278 break; 279 } 280 } 281 } 282 283 CurPPLexer->ParsingPreprocessorDirective = false; 284 // Restore comment saving mode. 285 if (CurLexer) CurLexer->SetCommentRetentionState(KeepComments); 286 } 287 288 // Finally, if we are out of the conditional (saw an #endif or ran off the end 289 // of the file, just stop skipping and return to lexing whatever came after 290 // the #if block. 291 CurPPLexer->LexingRawMode = false; 292} 293 294/// LookupFile - Given a "foo" or <foo> reference, look up the indicated file, 295/// return null on failure. isAngled indicates whether the file reference is 296/// for system #include's or not (i.e. using <> instead of ""). 297const FileEntry *Preprocessor::LookupFile(const char *FilenameStart, 298 const char *FilenameEnd, 299 bool isAngled, 300 const DirectoryLookup *FromDir, 301 const DirectoryLookup *&CurDir) { 302 // If the header lookup mechanism may be relative to the current file, pass in 303 // info about where the current file is. 304 const FileEntry *CurFileEnt = 0; 305 if (!FromDir) { 306 SourceLocation FileLoc = getCurrentFileLexer()->getFileLoc(); 307 CurFileEnt = SourceMgr.getFileEntryForLoc(FileLoc); 308 } 309 310 // Do a standard file entry lookup. 311 CurDir = CurDirLookup; 312 const FileEntry *FE = 313 HeaderInfo.LookupFile(FilenameStart, FilenameEnd, 314 isAngled, FromDir, CurDir, CurFileEnt); 315 if (FE) return FE; 316 317 // Otherwise, see if this is a subframework header. If so, this is relative 318 // to one of the headers on the #include stack. Walk the list of the current 319 // headers on the #include stack and pass them to HeaderInfo. 320 if (CurLexer && !CurLexer->Is_PragmaLexer) { 321 if ((CurFileEnt = SourceMgr.getFileEntryForLoc(CurLexer->getFileLoc()))) 322 if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart, FilenameEnd, 323 CurFileEnt))) 324 return FE; 325 } 326 327 for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) { 328 IncludeStackInfo &ISEntry = IncludeMacroStack[e-i-1]; 329 if (ISEntry.TheLexer && !ISEntry.TheLexer->Is_PragmaLexer) { 330 if ((CurFileEnt = 331 SourceMgr.getFileEntryForLoc(ISEntry.TheLexer->getFileLoc()))) 332 if ((FE = HeaderInfo.LookupSubframeworkHeader(FilenameStart, 333 FilenameEnd, CurFileEnt))) 334 return FE; 335 } 336 } 337 338 // Otherwise, we really couldn't find the file. 339 return 0; 340} 341 342 343//===----------------------------------------------------------------------===// 344// Preprocessor Directive Handling. 345//===----------------------------------------------------------------------===// 346 347/// HandleDirective - This callback is invoked when the lexer sees a # token 348/// at the start of a line. This consumes the directive, modifies the 349/// lexer/preprocessor state, and advances the lexer(s) so that the next token 350/// read is the correct one. 351void Preprocessor::HandleDirective(Token &Result) { 352 // FIXME: Traditional: # with whitespace before it not recognized by K&R? 353 354 // We just parsed a # character at the start of a line, so we're in directive 355 // mode. Tell the lexer this so any newlines we see will be converted into an 356 // EOM token (which terminates the directive). 357 CurPPLexer->ParsingPreprocessorDirective = true; 358 359 ++NumDirectives; 360 361 // We are about to read a token. For the multiple-include optimization FA to 362 // work, we have to remember if we had read any tokens *before* this 363 // pp-directive. 364 bool ReadAnyTokensBeforeDirective = CurPPLexer->MIOpt.getHasReadAnyTokensVal(); 365 366 // Read the next token, the directive flavor. This isn't expanded due to 367 // C99 6.10.3p8. 368 LexUnexpandedToken(Result); 369 370 // C99 6.10.3p11: Is this preprocessor directive in macro invocation? e.g.: 371 // #define A(x) #x 372 // A(abc 373 // #warning blah 374 // def) 375 // If so, the user is relying on non-portable behavior, emit a diagnostic. 376 if (InMacroArgs) 377 Diag(Result, diag::ext_embedded_directive); 378 379TryAgain: 380 switch (Result.getKind()) { 381 case tok::eom: 382 return; // null directive. 383 case tok::comment: 384 // Handle stuff like "# /*foo*/ define X" in -E -C mode. 385 LexUnexpandedToken(Result); 386 goto TryAgain; 387 388 case tok::numeric_constant: 389 // FIXME: implement # 7 line numbers! 390 DiscardUntilEndOfDirective(); 391 return; 392 default: 393 IdentifierInfo *II = Result.getIdentifierInfo(); 394 if (II == 0) break; // Not an identifier. 395 396 // Ask what the preprocessor keyword ID is. 397 switch (II->getPPKeywordID()) { 398 default: break; 399 // C99 6.10.1 - Conditional Inclusion. 400 case tok::pp_if: 401 return HandleIfDirective(Result, ReadAnyTokensBeforeDirective); 402 case tok::pp_ifdef: 403 return HandleIfdefDirective(Result, false, true/*not valid for miopt*/); 404 case tok::pp_ifndef: 405 return HandleIfdefDirective(Result, true, ReadAnyTokensBeforeDirective); 406 case tok::pp_elif: 407 return HandleElifDirective(Result); 408 case tok::pp_else: 409 return HandleElseDirective(Result); 410 case tok::pp_endif: 411 return HandleEndifDirective(Result); 412 413 // C99 6.10.2 - Source File Inclusion. 414 case tok::pp_include: 415 return HandleIncludeDirective(Result); // Handle #include. 416 417 // C99 6.10.3 - Macro Replacement. 418 case tok::pp_define: 419 return HandleDefineDirective(Result); 420 case tok::pp_undef: 421 return HandleUndefDirective(Result); 422 423 // C99 6.10.4 - Line Control. 424 case tok::pp_line: 425 // FIXME: implement #line 426 DiscardUntilEndOfDirective(); 427 return; 428 429 // C99 6.10.5 - Error Directive. 430 case tok::pp_error: 431 return HandleUserDiagnosticDirective(Result, false); 432 433 // C99 6.10.6 - Pragma Directive. 434 case tok::pp_pragma: 435 return HandlePragmaDirective(); 436 437 // GNU Extensions. 438 case tok::pp_import: 439 return HandleImportDirective(Result); 440 case tok::pp_include_next: 441 return HandleIncludeNextDirective(Result); 442 443 case tok::pp_warning: 444 Diag(Result, diag::ext_pp_warning_directive); 445 return HandleUserDiagnosticDirective(Result, true); 446 case tok::pp_ident: 447 return HandleIdentSCCSDirective(Result); 448 case tok::pp_sccs: 449 return HandleIdentSCCSDirective(Result); 450 case tok::pp_assert: 451 //isExtension = true; // FIXME: implement #assert 452 break; 453 case tok::pp_unassert: 454 //isExtension = true; // FIXME: implement #unassert 455 break; 456 } 457 break; 458 } 459 460 // If we reached here, the preprocessing token is not valid! 461 Diag(Result, diag::err_pp_invalid_directive); 462 463 // Read the rest of the PP line. 464 DiscardUntilEndOfDirective(); 465 466 // Okay, we're done parsing the directive. 467} 468 469void Preprocessor::HandleUserDiagnosticDirective(Token &Tok, 470 bool isWarning) { 471 // Read the rest of the line raw. We do this because we don't want macros 472 // to be expanded and we don't require that the tokens be valid preprocessing 473 // tokens. For example, this is allowed: "#warning ` 'foo". GCC does 474 // collapse multiple consequtive white space between tokens, but this isn't 475 // specified by the standard. 476 std::string Message = CurLexer->ReadToEndOfLine(); 477 478 unsigned DiagID = isWarning ? diag::pp_hash_warning : diag::err_pp_hash_error; 479 Diag(Tok, DiagID) << Message; 480} 481 482/// HandleIdentSCCSDirective - Handle a #ident/#sccs directive. 483/// 484void Preprocessor::HandleIdentSCCSDirective(Token &Tok) { 485 // Yes, this directive is an extension. 486 Diag(Tok, diag::ext_pp_ident_directive); 487 488 // Read the string argument. 489 Token StrTok; 490 Lex(StrTok); 491 492 // If the token kind isn't a string, it's a malformed directive. 493 if (StrTok.isNot(tok::string_literal) && 494 StrTok.isNot(tok::wide_string_literal)) { 495 Diag(StrTok, diag::err_pp_malformed_ident); 496 return; 497 } 498 499 // Verify that there is nothing after the string, other than EOM. 500 CheckEndOfDirective("#ident"); 501 502 if (Callbacks) 503 Callbacks->Ident(Tok.getLocation(), getSpelling(StrTok)); 504} 505 506//===----------------------------------------------------------------------===// 507// Preprocessor Include Directive Handling. 508//===----------------------------------------------------------------------===// 509 510/// GetIncludeFilenameSpelling - Turn the specified lexer token into a fully 511/// checked and spelled filename, e.g. as an operand of #include. This returns 512/// true if the input filename was in <>'s or false if it were in ""'s. The 513/// caller is expected to provide a buffer that is large enough to hold the 514/// spelling of the filename, but is also expected to handle the case when 515/// this method decides to use a different buffer. 516bool Preprocessor::GetIncludeFilenameSpelling(SourceLocation Loc, 517 const char *&BufStart, 518 const char *&BufEnd) { 519 // Get the text form of the filename. 520 assert(BufStart != BufEnd && "Can't have tokens with empty spellings!"); 521 522 // Make sure the filename is <x> or "x". 523 bool isAngled; 524 if (BufStart[0] == '<') { 525 if (BufEnd[-1] != '>') { 526 Diag(Loc, diag::err_pp_expects_filename); 527 BufStart = 0; 528 return true; 529 } 530 isAngled = true; 531 } else if (BufStart[0] == '"') { 532 if (BufEnd[-1] != '"') { 533 Diag(Loc, diag::err_pp_expects_filename); 534 BufStart = 0; 535 return true; 536 } 537 isAngled = false; 538 } else { 539 Diag(Loc, diag::err_pp_expects_filename); 540 BufStart = 0; 541 return true; 542 } 543 544 // Diagnose #include "" as invalid. 545 if (BufEnd-BufStart <= 2) { 546 Diag(Loc, diag::err_pp_empty_filename); 547 BufStart = 0; 548 return ""; 549 } 550 551 // Skip the brackets. 552 ++BufStart; 553 --BufEnd; 554 return isAngled; 555} 556 557/// ConcatenateIncludeName - Handle cases where the #include name is expanded 558/// from a macro as multiple tokens, which need to be glued together. This 559/// occurs for code like: 560/// #define FOO <a/b.h> 561/// #include FOO 562/// because in this case, "<a/b.h>" is returned as 7 tokens, not one. 563/// 564/// This code concatenates and consumes tokens up to the '>' token. It returns 565/// false if the > was found, otherwise it returns true if it finds and consumes 566/// the EOM marker. 567static bool ConcatenateIncludeName(llvm::SmallVector<char, 128> &FilenameBuffer, 568 Preprocessor &PP) { 569 Token CurTok; 570 571 PP.Lex(CurTok); 572 while (CurTok.isNot(tok::eom)) { 573 // Append the spelling of this token to the buffer. If there was a space 574 // before it, add it now. 575 if (CurTok.hasLeadingSpace()) 576 FilenameBuffer.push_back(' '); 577 578 // Get the spelling of the token, directly into FilenameBuffer if possible. 579 unsigned PreAppendSize = FilenameBuffer.size(); 580 FilenameBuffer.resize(PreAppendSize+CurTok.getLength()); 581 582 const char *BufPtr = &FilenameBuffer[PreAppendSize]; 583 unsigned ActualLen = PP.getSpelling(CurTok, BufPtr); 584 585 // If the token was spelled somewhere else, copy it into FilenameBuffer. 586 if (BufPtr != &FilenameBuffer[PreAppendSize]) 587 memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen); 588 589 // Resize FilenameBuffer to the correct size. 590 if (CurTok.getLength() != ActualLen) 591 FilenameBuffer.resize(PreAppendSize+ActualLen); 592 593 // If we found the '>' marker, return success. 594 if (CurTok.is(tok::greater)) 595 return false; 596 597 PP.Lex(CurTok); 598 } 599 600 // If we hit the eom marker, emit an error and return true so that the caller 601 // knows the EOM has been read. 602 PP.Diag(CurTok.getLocation(), diag::err_pp_expects_filename); 603 return true; 604} 605 606/// HandleIncludeDirective - The "#include" tokens have just been read, read the 607/// file to be included from the lexer, then include it! This is a common 608/// routine with functionality shared between #include, #include_next and 609/// #import. LookupFrom is set when this is a #include_next directive, it 610/// specifies the file to start searching from. 611void Preprocessor::HandleIncludeDirective(Token &IncludeTok, 612 const DirectoryLookup *LookupFrom, 613 bool isImport) { 614 615 Token FilenameTok; 616 CurPPLexer->LexIncludeFilename(FilenameTok); 617 618 // Reserve a buffer to get the spelling. 619 llvm::SmallVector<char, 128> FilenameBuffer; 620 const char *FilenameStart, *FilenameEnd; 621 622 switch (FilenameTok.getKind()) { 623 case tok::eom: 624 // If the token kind is EOM, the error has already been diagnosed. 625 return; 626 627 case tok::angle_string_literal: 628 case tok::string_literal: { 629 FilenameBuffer.resize(FilenameTok.getLength()); 630 FilenameStart = &FilenameBuffer[0]; 631 unsigned Len = getSpelling(FilenameTok, FilenameStart); 632 FilenameEnd = FilenameStart+Len; 633 break; 634 } 635 636 case tok::less: 637 // This could be a <foo/bar.h> file coming from a macro expansion. In this 638 // case, glue the tokens together into FilenameBuffer and interpret those. 639 FilenameBuffer.push_back('<'); 640 if (ConcatenateIncludeName(FilenameBuffer, *this)) 641 return; // Found <eom> but no ">"? Diagnostic already emitted. 642 FilenameStart = &FilenameBuffer[0]; 643 FilenameEnd = &FilenameBuffer[FilenameBuffer.size()]; 644 break; 645 default: 646 Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename); 647 DiscardUntilEndOfDirective(); 648 return; 649 } 650 651 bool isAngled = GetIncludeFilenameSpelling(FilenameTok.getLocation(), 652 FilenameStart, FilenameEnd); 653 // If GetIncludeFilenameSpelling set the start ptr to null, there was an 654 // error. 655 if (FilenameStart == 0) { 656 DiscardUntilEndOfDirective(); 657 return; 658 } 659 660 // Verify that there is nothing after the filename, other than EOM. Use the 661 // preprocessor to lex this in case lexing the filename entered a macro. 662 CheckEndOfDirective("#include"); 663 664 // Check that we don't have infinite #include recursion. 665 if (IncludeMacroStack.size() == MaxAllowedIncludeStackDepth-1) { 666 Diag(FilenameTok, diag::err_pp_include_too_deep); 667 return; 668 } 669 670 // Search include directories. 671 const DirectoryLookup *CurDir; 672 const FileEntry *File = LookupFile(FilenameStart, FilenameEnd, 673 isAngled, LookupFrom, CurDir); 674 if (File == 0) { 675 Diag(FilenameTok, diag::err_pp_file_not_found) 676 << std::string(FilenameStart, FilenameEnd); 677 return; 678 } 679 680 // Ask HeaderInfo if we should enter this #include file. If not, #including 681 // this file will have no effect. 682 if (!HeaderInfo.ShouldEnterIncludeFile(File, isImport)) 683 return; 684 685 // The #included file will be considered to be a system header if either it is 686 // in a system include directory, or if the #includer is a system include 687 // header. 688 SrcMgr::CharacteristicKind FileCharacter = 689 std::max(HeaderInfo.getFileDirFlavor(File), 690 SourceMgr.getFileCharacteristic(getCurrentFileLexer()->getFileLoc())); 691 692 // Look up the file, create a File ID for it. 693 unsigned FileID = SourceMgr.createFileID(File, FilenameTok.getLocation(), 694 FileCharacter); 695 if (FileID == 0) { 696 Diag(FilenameTok, diag::err_pp_file_not_found) 697 << std::string(FilenameStart, FilenameEnd); 698 return; 699 } 700 701 // Finally, if all is good, enter the new file! 702 EnterSourceFile(FileID, CurDir); 703} 704 705/// HandleIncludeNextDirective - Implements #include_next. 706/// 707void Preprocessor::HandleIncludeNextDirective(Token &IncludeNextTok) { 708 Diag(IncludeNextTok, diag::ext_pp_include_next_directive); 709 710 // #include_next is like #include, except that we start searching after 711 // the current found directory. If we can't do this, issue a 712 // diagnostic. 713 const DirectoryLookup *Lookup = CurDirLookup; 714 if (isInPrimaryFile()) { 715 Lookup = 0; 716 Diag(IncludeNextTok, diag::pp_include_next_in_primary); 717 } else if (Lookup == 0) { 718 Diag(IncludeNextTok, diag::pp_include_next_absolute_path); 719 } else { 720 // Start looking up in the next directory. 721 ++Lookup; 722 } 723 724 return HandleIncludeDirective(IncludeNextTok, Lookup); 725} 726 727/// HandleImportDirective - Implements #import. 728/// 729void Preprocessor::HandleImportDirective(Token &ImportTok) { 730 Diag(ImportTok, diag::ext_pp_import_directive); 731 732 return HandleIncludeDirective(ImportTok, 0, true); 733} 734 735//===----------------------------------------------------------------------===// 736// Preprocessor Macro Directive Handling. 737//===----------------------------------------------------------------------===// 738 739/// ReadMacroDefinitionArgList - The ( starting an argument list of a macro 740/// definition has just been read. Lex the rest of the arguments and the 741/// closing ), updating MI with what we learn. Return true if an error occurs 742/// parsing the arg list. 743bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI) { 744 llvm::SmallVector<IdentifierInfo*, 32> Arguments; 745 746 Token Tok; 747 while (1) { 748 LexUnexpandedToken(Tok); 749 switch (Tok.getKind()) { 750 case tok::r_paren: 751 // Found the end of the argument list. 752 if (Arguments.empty()) { // #define FOO() 753 MI->setArgumentList(Arguments.begin(), Arguments.end()); 754 return false; 755 } 756 // Otherwise we have #define FOO(A,) 757 Diag(Tok, diag::err_pp_expected_ident_in_arg_list); 758 return true; 759 case tok::ellipsis: // #define X(... -> C99 varargs 760 // Warn if use of C99 feature in non-C99 mode. 761 if (!Features.C99) Diag(Tok, diag::ext_variadic_macro); 762 763 // Lex the token after the identifier. 764 LexUnexpandedToken(Tok); 765 if (Tok.isNot(tok::r_paren)) { 766 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 767 return true; 768 } 769 // Add the __VA_ARGS__ identifier as an argument. 770 Arguments.push_back(Ident__VA_ARGS__); 771 MI->setIsC99Varargs(); 772 MI->setArgumentList(Arguments.begin(), Arguments.end()); 773 return false; 774 case tok::eom: // #define X( 775 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 776 return true; 777 default: 778 // Handle keywords and identifiers here to accept things like 779 // #define Foo(for) for. 780 IdentifierInfo *II = Tok.getIdentifierInfo(); 781 if (II == 0) { 782 // #define X(1 783 Diag(Tok, diag::err_pp_invalid_tok_in_arg_list); 784 return true; 785 } 786 787 // If this is already used as an argument, it is used multiple times (e.g. 788 // #define X(A,A. 789 if (std::find(Arguments.begin(), Arguments.end(), II) != 790 Arguments.end()) { // C99 6.10.3p6 791 Diag(Tok, diag::err_pp_duplicate_name_in_arg_list) << II->getName(); 792 return true; 793 } 794 795 // Add the argument to the macro info. 796 Arguments.push_back(II); 797 798 // Lex the token after the identifier. 799 LexUnexpandedToken(Tok); 800 801 switch (Tok.getKind()) { 802 default: // #define X(A B 803 Diag(Tok, diag::err_pp_expected_comma_in_arg_list); 804 return true; 805 case tok::r_paren: // #define X(A) 806 MI->setArgumentList(Arguments.begin(), Arguments.end()); 807 return false; 808 case tok::comma: // #define X(A, 809 break; 810 case tok::ellipsis: // #define X(A... -> GCC extension 811 // Diagnose extension. 812 Diag(Tok, diag::ext_named_variadic_macro); 813 814 // Lex the token after the identifier. 815 LexUnexpandedToken(Tok); 816 if (Tok.isNot(tok::r_paren)) { 817 Diag(Tok, diag::err_pp_missing_rparen_in_macro_def); 818 return true; 819 } 820 821 MI->setIsGNUVarargs(); 822 MI->setArgumentList(Arguments.begin(), Arguments.end()); 823 return false; 824 } 825 } 826 } 827} 828 829/// HandleDefineDirective - Implements #define. This consumes the entire macro 830/// line then lets the caller lex the next real token. 831void Preprocessor::HandleDefineDirective(Token &DefineTok) { 832 ++NumDefined; 833 834 Token MacroNameTok; 835 ReadMacroName(MacroNameTok, 1); 836 837 // Error reading macro name? If so, diagnostic already issued. 838 if (MacroNameTok.is(tok::eom)) 839 return; 840 841 // If we are supposed to keep comments in #defines, reenable comment saving 842 // mode. 843 if (CurLexer) CurLexer->SetCommentRetentionState(KeepMacroComments); 844 845 // Create the new macro. 846 MacroInfo *MI = new MacroInfo(MacroNameTok.getLocation()); 847 848 Token Tok; 849 LexUnexpandedToken(Tok); 850 851 // If this is a function-like macro definition, parse the argument list, 852 // marking each of the identifiers as being used as macro arguments. Also, 853 // check other constraints on the first token of the macro body. 854 if (Tok.is(tok::eom)) { 855 // If there is no body to this macro, we have no special handling here. 856 } else if (Tok.is(tok::l_paren) && !Tok.hasLeadingSpace()) { 857 // This is a function-like macro definition. Read the argument list. 858 MI->setIsFunctionLike(); 859 if (ReadMacroDefinitionArgList(MI)) { 860 // Forget about MI. 861 delete MI; 862 // Throw away the rest of the line. 863 if (CurPPLexer->ParsingPreprocessorDirective) 864 DiscardUntilEndOfDirective(); 865 return; 866 } 867 868 // Read the first token after the arg list for down below. 869 LexUnexpandedToken(Tok); 870 } else if (!Tok.hasLeadingSpace()) { 871 // C99 requires whitespace between the macro definition and the body. Emit 872 // a diagnostic for something like "#define X+". 873 if (Features.C99) { 874 Diag(Tok, diag::ext_c99_whitespace_required_after_macro_name); 875 } else { 876 // FIXME: C90/C++ do not get this diagnostic, but it does get a similar 877 // one in some cases! 878 } 879 } else { 880 // This is a normal token with leading space. Clear the leading space 881 // marker on the first token to get proper expansion. 882 Tok.clearFlag(Token::LeadingSpace); 883 } 884 885 // If this is a definition of a variadic C99 function-like macro, not using 886 // the GNU named varargs extension, enabled __VA_ARGS__. 887 888 // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro. 889 // This gets unpoisoned where it is allowed. 890 assert(Ident__VA_ARGS__->isPoisoned() && "__VA_ARGS__ should be poisoned!"); 891 if (MI->isC99Varargs()) 892 Ident__VA_ARGS__->setIsPoisoned(false); 893 894 // Read the rest of the macro body. 895 if (MI->isObjectLike()) { 896 // Object-like macros are very simple, just read their body. 897 while (Tok.isNot(tok::eom)) { 898 MI->AddTokenToBody(Tok); 899 // Get the next token of the macro. 900 LexUnexpandedToken(Tok); 901 } 902 903 } else { 904 // Otherwise, read the body of a function-like macro. This has to validate 905 // the # (stringize) operator. 906 while (Tok.isNot(tok::eom)) { 907 MI->AddTokenToBody(Tok); 908 909 // Check C99 6.10.3.2p1: ensure that # operators are followed by macro 910 // parameters in function-like macro expansions. 911 if (Tok.isNot(tok::hash)) { 912 // Get the next token of the macro. 913 LexUnexpandedToken(Tok); 914 continue; 915 } 916 917 // Get the next token of the macro. 918 LexUnexpandedToken(Tok); 919 920 // Not a macro arg identifier? 921 if (!Tok.getIdentifierInfo() || 922 MI->getArgumentNum(Tok.getIdentifierInfo()) == -1) { 923 Diag(Tok, diag::err_pp_stringize_not_parameter); 924 delete MI; 925 926 // Disable __VA_ARGS__ again. 927 Ident__VA_ARGS__->setIsPoisoned(true); 928 return; 929 } 930 931 // Things look ok, add the param name token to the macro. 932 MI->AddTokenToBody(Tok); 933 934 // Get the next token of the macro. 935 LexUnexpandedToken(Tok); 936 } 937 } 938 939 940 // Disable __VA_ARGS__ again. 941 Ident__VA_ARGS__->setIsPoisoned(true); 942 943 // Check that there is no paste (##) operator at the begining or end of the 944 // replacement list. 945 unsigned NumTokens = MI->getNumTokens(); 946 if (NumTokens != 0) { 947 if (MI->getReplacementToken(0).is(tok::hashhash)) { 948 Diag(MI->getReplacementToken(0), diag::err_paste_at_start); 949 delete MI; 950 return; 951 } 952 if (MI->getReplacementToken(NumTokens-1).is(tok::hashhash)) { 953 Diag(MI->getReplacementToken(NumTokens-1), diag::err_paste_at_end); 954 delete MI; 955 return; 956 } 957 } 958 959 // If this is the primary source file, remember that this macro hasn't been 960 // used yet. 961 if (isInPrimaryFile()) 962 MI->setIsUsed(false); 963 964 // Finally, if this identifier already had a macro defined for it, verify that 965 // the macro bodies are identical and free the old definition. 966 if (MacroInfo *OtherMI = getMacroInfo(MacroNameTok.getIdentifierInfo())) { 967 if (!OtherMI->isUsed()) 968 Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used); 969 970 // Macros must be identical. This means all tokes and whitespace separation 971 // must be the same. C99 6.10.3.2. 972 if (!MI->isIdenticalTo(*OtherMI, *this)) { 973 Diag(MI->getDefinitionLoc(), diag::ext_pp_macro_redef) 974 << MacroNameTok.getIdentifierInfo()->getName(); 975 Diag(OtherMI->getDefinitionLoc(), diag::ext_pp_macro_redef2); 976 } 977 delete OtherMI; 978 } 979 980 setMacroInfo(MacroNameTok.getIdentifierInfo(), MI); 981} 982 983/// HandleUndefDirective - Implements #undef. 984/// 985void Preprocessor::HandleUndefDirective(Token &UndefTok) { 986 ++NumUndefined; 987 988 Token MacroNameTok; 989 ReadMacroName(MacroNameTok, 2); 990 991 // Error reading macro name? If so, diagnostic already issued. 992 if (MacroNameTok.is(tok::eom)) 993 return; 994 995 // Check to see if this is the last token on the #undef line. 996 CheckEndOfDirective("#undef"); 997 998 // Okay, we finally have a valid identifier to undef. 999 MacroInfo *MI = getMacroInfo(MacroNameTok.getIdentifierInfo()); 1000 1001 // If the macro is not defined, this is a noop undef, just return. 1002 if (MI == 0) return; 1003 1004 if (!MI->isUsed()) 1005 Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used); 1006 1007 // Free macro definition. 1008 delete MI; 1009 setMacroInfo(MacroNameTok.getIdentifierInfo(), 0); 1010} 1011 1012 1013//===----------------------------------------------------------------------===// 1014// Preprocessor Conditional Directive Handling. 1015//===----------------------------------------------------------------------===// 1016 1017/// HandleIfdefDirective - Implements the #ifdef/#ifndef directive. isIfndef is 1018/// true when this is a #ifndef directive. ReadAnyTokensBeforeDirective is true 1019/// if any tokens have been returned or pp-directives activated before this 1020/// #ifndef has been lexed. 1021/// 1022void Preprocessor::HandleIfdefDirective(Token &Result, bool isIfndef, 1023 bool ReadAnyTokensBeforeDirective) { 1024 ++NumIf; 1025 Token DirectiveTok = Result; 1026 1027 Token MacroNameTok; 1028 ReadMacroName(MacroNameTok); 1029 1030 // Error reading macro name? If so, diagnostic already issued. 1031 if (MacroNameTok.is(tok::eom)) { 1032 // Skip code until we get to #endif. This helps with recovery by not 1033 // emitting an error when the #endif is reached. 1034 SkipExcludedConditionalBlock(DirectiveTok.getLocation(), 1035 /*Foundnonskip*/false, /*FoundElse*/false); 1036 return; 1037 } 1038 1039 // Check to see if this is the last token on the #if[n]def line. 1040 CheckEndOfDirective(isIfndef ? "#ifndef" : "#ifdef"); 1041 1042 if (CurPPLexer->getConditionalStackDepth() == 0) { 1043 // If the start of a top-level #ifdef, inform MIOpt. 1044 if (!ReadAnyTokensBeforeDirective) { 1045 assert(isIfndef && "#ifdef shouldn't reach here"); 1046 CurPPLexer->MIOpt.EnterTopLevelIFNDEF(MacroNameTok.getIdentifierInfo()); 1047 } else 1048 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1049 } 1050 1051 IdentifierInfo *MII = MacroNameTok.getIdentifierInfo(); 1052 MacroInfo *MI = getMacroInfo(MII); 1053 1054 // If there is a macro, process it. 1055 if (MI) // Mark it used. 1056 MI->setIsUsed(true); 1057 1058 // Should we include the stuff contained by this directive? 1059 if (!MI == isIfndef) { 1060 // Yes, remember that we are inside a conditional, then lex the next token. 1061 CurPPLexer->pushConditionalLevel(DirectiveTok.getLocation(), /*wasskip*/false, 1062 /*foundnonskip*/true, /*foundelse*/false); 1063 } else { 1064 // No, skip the contents of this block and return the first token after it. 1065 SkipExcludedConditionalBlock(DirectiveTok.getLocation(), 1066 /*Foundnonskip*/false, 1067 /*FoundElse*/false); 1068 } 1069} 1070 1071/// HandleIfDirective - Implements the #if directive. 1072/// 1073void Preprocessor::HandleIfDirective(Token &IfToken, 1074 bool ReadAnyTokensBeforeDirective) { 1075 ++NumIf; 1076 1077 // Parse and evaluation the conditional expression. 1078 IdentifierInfo *IfNDefMacro = 0; 1079 bool ConditionalTrue = EvaluateDirectiveExpression(IfNDefMacro); 1080 1081 1082 // If this condition is equivalent to #ifndef X, and if this is the first 1083 // directive seen, handle it for the multiple-include optimization. 1084 if (CurPPLexer->getConditionalStackDepth() == 0) { 1085 if (!ReadAnyTokensBeforeDirective && IfNDefMacro) 1086 CurPPLexer->MIOpt.EnterTopLevelIFNDEF(IfNDefMacro); 1087 else 1088 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1089 } 1090 1091 // Should we include the stuff contained by this directive? 1092 if (ConditionalTrue) { 1093 // Yes, remember that we are inside a conditional, then lex the next token. 1094 CurPPLexer->pushConditionalLevel(IfToken.getLocation(), /*wasskip*/false, 1095 /*foundnonskip*/true, /*foundelse*/false); 1096 } else { 1097 // No, skip the contents of this block and return the first token after it. 1098 SkipExcludedConditionalBlock(IfToken.getLocation(), /*Foundnonskip*/false, 1099 /*FoundElse*/false); 1100 } 1101} 1102 1103/// HandleEndifDirective - Implements the #endif directive. 1104/// 1105void Preprocessor::HandleEndifDirective(Token &EndifToken) { 1106 ++NumEndif; 1107 1108 // Check that this is the whole directive. 1109 CheckEndOfDirective("#endif"); 1110 1111 PPConditionalInfo CondInfo; 1112 if (CurPPLexer->popConditionalLevel(CondInfo)) { 1113 // No conditionals on the stack: this is an #endif without an #if. 1114 Diag(EndifToken, diag::err_pp_endif_without_if); 1115 return; 1116 } 1117 1118 // If this the end of a top-level #endif, inform MIOpt. 1119 if (CurPPLexer->getConditionalStackDepth() == 0) 1120 CurPPLexer->MIOpt.ExitTopLevelConditional(); 1121 1122 assert(!CondInfo.WasSkipping && !CurPPLexer->LexingRawMode && 1123 "This code should only be reachable in the non-skipping case!"); 1124} 1125 1126 1127void Preprocessor::HandleElseDirective(Token &Result) { 1128 ++NumElse; 1129 1130 // #else directive in a non-skipping conditional... start skipping. 1131 CheckEndOfDirective("#else"); 1132 1133 PPConditionalInfo CI; 1134 if (CurPPLexer->popConditionalLevel(CI)) { 1135 Diag(Result, diag::pp_err_else_without_if); 1136 return; 1137 } 1138 1139 // If this is a top-level #else, inform the MIOpt. 1140 if (CurPPLexer->getConditionalStackDepth() == 0) 1141 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1142 1143 // If this is a #else with a #else before it, report the error. 1144 if (CI.FoundElse) Diag(Result, diag::pp_err_else_after_else); 1145 1146 // Finally, skip the rest of the contents of this block and return the first 1147 // token after it. 1148 return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true, 1149 /*FoundElse*/true); 1150} 1151 1152void Preprocessor::HandleElifDirective(Token &ElifToken) { 1153 ++NumElse; 1154 1155 // #elif directive in a non-skipping conditional... start skipping. 1156 // We don't care what the condition is, because we will always skip it (since 1157 // the block immediately before it was included). 1158 DiscardUntilEndOfDirective(); 1159 1160 PPConditionalInfo CI; 1161 if (CurPPLexer->popConditionalLevel(CI)) { 1162 Diag(ElifToken, diag::pp_err_elif_without_if); 1163 return; 1164 } 1165 1166 // If this is a top-level #elif, inform the MIOpt. 1167 if (CurPPLexer->getConditionalStackDepth() == 0) 1168 CurPPLexer->MIOpt.EnterTopLevelConditional(); 1169 1170 // If this is a #elif with a #else before it, report the error. 1171 if (CI.FoundElse) Diag(ElifToken, diag::pp_err_elif_after_else); 1172 1173 // Finally, skip the rest of the contents of this block and return the first 1174 // token after it. 1175 return SkipExcludedConditionalBlock(CI.IfLoc, /*Foundnonskip*/true, 1176 /*FoundElse*/CI.FoundElse); 1177} 1178 1179