1 //===--- PPLexerChange.cpp - Handle changing lexers in the 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 pieces of the Preprocessor interface that manage the 11 // current lexer stack. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "clang/Lex/Preprocessor.h" 16 #include "clang/Lex/HeaderSearch.h" 17 #include "clang/Lex/MacroInfo.h" 18 #include "clang/Lex/LexDiagnostic.h" 19 #include "clang/Basic/FileManager.h" 20 #include "clang/Basic/SourceManager.h" 21 #include "llvm/Support/FileSystem.h" 22 #include "llvm/Support/MemoryBuffer.h" 23 #include "llvm/Support/PathV2.h" 24 #include "llvm/ADT/StringSwitch.h" 25 using namespace clang; 26 27 PPCallbacks::~PPCallbacks() {} 28 29 //===----------------------------------------------------------------------===// 30 // Miscellaneous Methods. 31 //===----------------------------------------------------------------------===// 32 33 /// isInPrimaryFile - Return true if we're in the top-level file, not in a 34 /// #include. This looks through macro expansions and active _Pragma lexers. 35 bool Preprocessor::isInPrimaryFile() const { 36 if (IsFileLexer()) 37 return IncludeMacroStack.empty(); 38 39 // If there are any stacked lexers, we're in a #include. 40 assert(IsFileLexer(IncludeMacroStack[0]) && 41 "Top level include stack isn't our primary lexer?"); 42 for (unsigned i = 1, e = IncludeMacroStack.size(); i != e; ++i) 43 if (IsFileLexer(IncludeMacroStack[i])) 44 return false; 45 return true; 46 } 47 48 /// getCurrentLexer - Return the current file lexer being lexed from. Note 49 /// that this ignores any potentially active macro expansions and _Pragma 50 /// expansions going on at the time. 51 PreprocessorLexer *Preprocessor::getCurrentFileLexer() const { 52 if (IsFileLexer()) 53 return CurPPLexer; 54 55 // Look for a stacked lexer. 56 for (unsigned i = IncludeMacroStack.size(); i != 0; --i) { 57 const IncludeStackInfo& ISI = IncludeMacroStack[i-1]; 58 if (IsFileLexer(ISI)) 59 return ISI.ThePPLexer; 60 } 61 return 0; 62 } 63 64 65 //===----------------------------------------------------------------------===// 66 // Methods for Entering and Callbacks for leaving various contexts 67 //===----------------------------------------------------------------------===// 68 69 /// EnterSourceFile - Add a source file to the top of the include stack and 70 /// start lexing tokens from it instead of the current buffer. 71 void Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir, 72 SourceLocation Loc) { 73 assert(CurTokenLexer == 0 && "Cannot #include a file inside a macro!"); 74 ++NumEnteredSourceFiles; 75 76 if (MaxIncludeStackDepth < IncludeMacroStack.size()) 77 MaxIncludeStackDepth = IncludeMacroStack.size(); 78 79 if (PTH) { 80 if (PTHLexer *PL = PTH->CreateLexer(FID)) { 81 EnterSourceFileWithPTH(PL, CurDir); 82 return; 83 } 84 } 85 86 // Get the MemoryBuffer for this FID, if it fails, we fail. 87 bool Invalid = false; 88 const llvm::MemoryBuffer *InputFile = 89 getSourceManager().getBuffer(FID, Loc, &Invalid); 90 if (Invalid) { 91 SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID); 92 Diag(Loc, diag::err_pp_error_opening_file) 93 << std::string(SourceMgr.getBufferName(FileStart)) << ""; 94 return; 95 } 96 97 if (isCodeCompletionEnabled() && 98 SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) { 99 CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID); 100 CodeCompletionLoc = 101 CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset); 102 } 103 104 EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir); 105 return; 106 } 107 108 /// EnterSourceFileWithLexer - Add a source file to the top of the include stack 109 /// and start lexing tokens from it instead of the current buffer. 110 void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer, 111 const DirectoryLookup *CurDir) { 112 113 // Add the current lexer to the include stack. 114 if (CurPPLexer || CurTokenLexer) 115 PushIncludeMacroStack(); 116 117 CurLexer.reset(TheLexer); 118 CurPPLexer = TheLexer; 119 CurDirLookup = CurDir; 120 if (CurLexerKind != CLK_LexAfterModuleImport) 121 CurLexerKind = CLK_Lexer; 122 123 // Notify the client, if desired, that we are in a new source file. 124 if (Callbacks && !CurLexer->Is_PragmaLexer) { 125 SrcMgr::CharacteristicKind FileType = 126 SourceMgr.getFileCharacteristic(CurLexer->getFileLoc()); 127 128 Callbacks->FileChanged(CurLexer->getFileLoc(), 129 PPCallbacks::EnterFile, FileType); 130 } 131 } 132 133 /// EnterSourceFileWithPTH - Add a source file to the top of the include stack 134 /// and start getting tokens from it using the PTH cache. 135 void Preprocessor::EnterSourceFileWithPTH(PTHLexer *PL, 136 const DirectoryLookup *CurDir) { 137 138 if (CurPPLexer || CurTokenLexer) 139 PushIncludeMacroStack(); 140 141 CurDirLookup = CurDir; 142 CurPTHLexer.reset(PL); 143 CurPPLexer = CurPTHLexer.get(); 144 if (CurLexerKind != CLK_LexAfterModuleImport) 145 CurLexerKind = CLK_PTHLexer; 146 147 // Notify the client, if desired, that we are in a new source file. 148 if (Callbacks) { 149 FileID FID = CurPPLexer->getFileID(); 150 SourceLocation EnterLoc = SourceMgr.getLocForStartOfFile(FID); 151 SrcMgr::CharacteristicKind FileType = 152 SourceMgr.getFileCharacteristic(EnterLoc); 153 Callbacks->FileChanged(EnterLoc, PPCallbacks::EnterFile, FileType); 154 } 155 } 156 157 /// EnterMacro - Add a Macro to the top of the include stack and start lexing 158 /// tokens from it instead of the current buffer. 159 void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd, 160 MacroArgs *Args) { 161 PushIncludeMacroStack(); 162 CurDirLookup = 0; 163 164 if (NumCachedTokenLexers == 0) { 165 CurTokenLexer.reset(new TokenLexer(Tok, ILEnd, Args, *this)); 166 } else { 167 CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]); 168 CurTokenLexer->Init(Tok, ILEnd, Args); 169 } 170 if (CurLexerKind != CLK_LexAfterModuleImport) 171 CurLexerKind = CLK_TokenLexer; 172 } 173 174 /// EnterTokenStream - Add a "macro" context to the top of the include stack, 175 /// which will cause the lexer to start returning the specified tokens. 176 /// 177 /// If DisableMacroExpansion is true, tokens lexed from the token stream will 178 /// not be subject to further macro expansion. Otherwise, these tokens will 179 /// be re-macro-expanded when/if expansion is enabled. 180 /// 181 /// If OwnsTokens is false, this method assumes that the specified stream of 182 /// tokens has a permanent owner somewhere, so they do not need to be copied. 183 /// If it is true, it assumes the array of tokens is allocated with new[] and 184 /// must be freed. 185 /// 186 void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks, 187 bool DisableMacroExpansion, 188 bool OwnsTokens) { 189 // Save our current state. 190 PushIncludeMacroStack(); 191 CurDirLookup = 0; 192 193 // Create a macro expander to expand from the specified token stream. 194 if (NumCachedTokenLexers == 0) { 195 CurTokenLexer.reset(new TokenLexer(Toks, NumToks, DisableMacroExpansion, 196 OwnsTokens, *this)); 197 } else { 198 CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]); 199 CurTokenLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens); 200 } 201 if (CurLexerKind != CLK_LexAfterModuleImport) 202 CurLexerKind = CLK_TokenLexer; 203 } 204 205 /// \brief Compute the relative path that names the given file relative to 206 /// the given directory. 207 static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir, 208 const FileEntry *File, 209 SmallString<128> &Result) { 210 Result.clear(); 211 212 StringRef FilePath = File->getDir()->getName(); 213 StringRef Path = FilePath; 214 while (!Path.empty()) { 215 if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) { 216 if (CurDir == Dir) { 217 Result = FilePath.substr(Path.size()); 218 llvm::sys::path::append(Result, 219 llvm::sys::path::filename(File->getName())); 220 return; 221 } 222 } 223 224 Path = llvm::sys::path::parent_path(Path); 225 } 226 227 Result = File->getName(); 228 } 229 230 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of 231 /// the current file. This either returns the EOF token or pops a level off 232 /// the include stack and keeps going. 233 bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) { 234 assert(!CurTokenLexer && 235 "Ending a file when currently in a macro!"); 236 237 // See if this file had a controlling macro. 238 if (CurPPLexer) { // Not ending a macro, ignore it. 239 if (const IdentifierInfo *ControllingMacro = 240 CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) { 241 // Okay, this has a controlling macro, remember in HeaderFileInfo. 242 if (const FileEntry *FE = 243 SourceMgr.getFileEntryForID(CurPPLexer->getFileID())) 244 HeaderInfo.SetFileControllingMacro(FE, ControllingMacro); 245 } 246 } 247 248 // Complain about reaching a true EOF within arc_cf_code_audited. 249 // We don't want to complain about reaching the end of a macro 250 // instantiation or a _Pragma. 251 if (PragmaARCCFCodeAuditedLoc.isValid() && 252 !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) { 253 Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited); 254 255 // Recover by leaving immediately. 256 PragmaARCCFCodeAuditedLoc = SourceLocation(); 257 } 258 259 // If this is a #include'd file, pop it off the include stack and continue 260 // lexing the #includer file. 261 if (!IncludeMacroStack.empty()) { 262 263 // If we lexed the code-completion file, act as if we reached EOF. 264 if (isCodeCompletionEnabled() && CurPPLexer && 265 SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) == 266 CodeCompletionFileLoc) { 267 if (CurLexer) { 268 Result.startToken(); 269 CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof); 270 CurLexer.reset(); 271 } else { 272 assert(CurPTHLexer && "Got EOF but no current lexer set!"); 273 CurPTHLexer->getEOF(Result); 274 CurPTHLexer.reset(); 275 } 276 277 CurPPLexer = 0; 278 return true; 279 } 280 281 if (!isEndOfMacro && CurPPLexer && 282 SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) { 283 // Notify SourceManager to record the number of FileIDs that were created 284 // during lexing of the #include'd file. 285 unsigned NumFIDs = 286 SourceMgr.local_sloc_entry_size() - 287 CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/; 288 SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs); 289 } 290 291 FileID ExitedFID; 292 if (Callbacks && !isEndOfMacro && CurPPLexer) 293 ExitedFID = CurPPLexer->getFileID(); 294 295 // We're done with the #included file. 296 RemoveTopOfLexerStack(); 297 298 // Notify the client, if desired, that we are in a new source file. 299 if (Callbacks && !isEndOfMacro && CurPPLexer) { 300 SrcMgr::CharacteristicKind FileType = 301 SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation()); 302 Callbacks->FileChanged(CurPPLexer->getSourceLocation(), 303 PPCallbacks::ExitFile, FileType, ExitedFID); 304 } 305 306 // Client should lex another token. 307 return false; 308 } 309 310 // If the file ends with a newline, form the EOF token on the newline itself, 311 // rather than "on the line following it", which doesn't exist. This makes 312 // diagnostics relating to the end of file include the last file that the user 313 // actually typed, which is goodness. 314 if (CurLexer) { 315 const char *EndPos = CurLexer->BufferEnd; 316 if (EndPos != CurLexer->BufferStart && 317 (EndPos[-1] == '\n' || EndPos[-1] == '\r')) { 318 --EndPos; 319 320 // Handle \n\r and \r\n: 321 if (EndPos != CurLexer->BufferStart && 322 (EndPos[-1] == '\n' || EndPos[-1] == '\r') && 323 EndPos[-1] != EndPos[0]) 324 --EndPos; 325 } 326 327 Result.startToken(); 328 CurLexer->BufferPtr = EndPos; 329 CurLexer->FormTokenWithChars(Result, EndPos, tok::eof); 330 331 if (!isIncrementalProcessingEnabled()) 332 // We're done with lexing. 333 CurLexer.reset(); 334 } else { 335 assert(CurPTHLexer && "Got EOF but no current lexer set!"); 336 CurPTHLexer->getEOF(Result); 337 CurPTHLexer.reset(); 338 } 339 340 if (!isIncrementalProcessingEnabled()) 341 CurPPLexer = 0; 342 343 // This is the end of the top-level file. 'WarnUnusedMacroLocs' has collected 344 // all macro locations that we need to warn because they are not used. 345 for (WarnUnusedMacroLocsTy::iterator 346 I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end(); I!=E; ++I) 347 Diag(*I, diag::pp_macro_not_used); 348 349 // If we are building a module that has an umbrella header, make sure that 350 // each of the headers within the directory covered by the umbrella header 351 // was actually included by the umbrella header. 352 if (Module *Mod = getCurrentModule()) { 353 if (Mod->getUmbrellaHeader()) { 354 SourceLocation StartLoc 355 = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID()); 356 357 if (getDiagnostics().getDiagnosticLevel( 358 diag::warn_uncovered_module_header, 359 StartLoc) != DiagnosticsEngine::Ignored) { 360 ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap(); 361 typedef llvm::sys::fs::recursive_directory_iterator 362 recursive_directory_iterator; 363 const DirectoryEntry *Dir = Mod->getUmbrellaDir(); 364 llvm::error_code EC; 365 for (recursive_directory_iterator Entry(Dir->getName(), EC), End; 366 Entry != End && !EC; Entry.increment(EC)) { 367 using llvm::StringSwitch; 368 369 // Check whether this entry has an extension typically associated with 370 // headers. 371 if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path())) 372 .Cases(".h", ".H", ".hh", ".hpp", true) 373 .Default(false)) 374 continue; 375 376 if (const FileEntry *Header = getFileManager().getFile(Entry->path())) 377 if (!getSourceManager().hasFileInfo(Header)) { 378 if (!ModMap.isHeaderInUnavailableModule(Header)) { 379 // Find the relative path that would access this header. 380 SmallString<128> RelativePath; 381 computeRelativePath(FileMgr, Dir, Header, RelativePath); 382 Diag(StartLoc, diag::warn_uncovered_module_header) 383 << RelativePath; 384 } 385 } 386 } 387 } 388 } 389 } 390 391 return true; 392 } 393 394 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer 395 /// hits the end of its token stream. 396 bool Preprocessor::HandleEndOfTokenLexer(Token &Result) { 397 assert(CurTokenLexer && !CurPPLexer && 398 "Ending a macro when currently in a #include file!"); 399 400 if (!MacroExpandingLexersStack.empty() && 401 MacroExpandingLexersStack.back().first == CurTokenLexer.get()) 402 removeCachedMacroExpandedTokensOfLastLexer(); 403 404 // Delete or cache the now-dead macro expander. 405 if (NumCachedTokenLexers == TokenLexerCacheSize) 406 CurTokenLexer.reset(); 407 else 408 TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take(); 409 410 // Handle this like a #include file being popped off the stack. 411 return HandleEndOfFile(Result, true); 412 } 413 414 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the 415 /// lexer stack. This should only be used in situations where the current 416 /// state of the top-of-stack lexer is unknown. 417 void Preprocessor::RemoveTopOfLexerStack() { 418 assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load"); 419 420 if (CurTokenLexer) { 421 // Delete or cache the now-dead macro expander. 422 if (NumCachedTokenLexers == TokenLexerCacheSize) 423 CurTokenLexer.reset(); 424 else 425 TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take(); 426 } 427 428 PopIncludeMacroStack(); 429 } 430 431 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a 432 /// comment (/##/) in microsoft mode, this method handles updating the current 433 /// state, returning the token on the next source line. 434 void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) { 435 assert(CurTokenLexer && !CurPPLexer && 436 "Pasted comment can only be formed from macro"); 437 438 // We handle this by scanning for the closest real lexer, switching it to 439 // raw mode and preprocessor mode. This will cause it to return \n as an 440 // explicit EOD token. 441 PreprocessorLexer *FoundLexer = 0; 442 bool LexerWasInPPMode = false; 443 for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) { 444 IncludeStackInfo &ISI = *(IncludeMacroStack.end()-i-1); 445 if (ISI.ThePPLexer == 0) continue; // Scan for a real lexer. 446 447 // Once we find a real lexer, mark it as raw mode (disabling macro 448 // expansions) and preprocessor mode (return EOD). We know that the lexer 449 // was *not* in raw mode before, because the macro that the comment came 450 // from was expanded. However, it could have already been in preprocessor 451 // mode (#if COMMENT) in which case we have to return it to that mode and 452 // return EOD. 453 FoundLexer = ISI.ThePPLexer; 454 FoundLexer->LexingRawMode = true; 455 LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective; 456 FoundLexer->ParsingPreprocessorDirective = true; 457 break; 458 } 459 460 // Okay, we either found and switched over the lexer, or we didn't find a 461 // lexer. In either case, finish off the macro the comment came from, getting 462 // the next token. 463 if (!HandleEndOfTokenLexer(Tok)) Lex(Tok); 464 465 // Discarding comments as long as we don't have EOF or EOD. This 'comments 466 // out' the rest of the line, including any tokens that came from other macros 467 // that were active, as in: 468 // #define submacro a COMMENT b 469 // submacro c 470 // which should lex to 'a' only: 'b' and 'c' should be removed. 471 while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof)) 472 Lex(Tok); 473 474 // If we got an eod token, then we successfully found the end of the line. 475 if (Tok.is(tok::eod)) { 476 assert(FoundLexer && "Can't get end of line without an active lexer"); 477 // Restore the lexer back to normal mode instead of raw mode. 478 FoundLexer->LexingRawMode = false; 479 480 // If the lexer was already in preprocessor mode, just return the EOD token 481 // to finish the preprocessor line. 482 if (LexerWasInPPMode) return; 483 484 // Otherwise, switch out of PP mode and return the next lexed token. 485 FoundLexer->ParsingPreprocessorDirective = false; 486 return Lex(Tok); 487 } 488 489 // If we got an EOF token, then we reached the end of the token stream but 490 // didn't find an explicit \n. This can only happen if there was no lexer 491 // active (an active lexer would return EOD at EOF if there was no \n in 492 // preprocessor directive mode), so just return EOF as our token. 493 assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode"); 494 } 495