clang  8.0.0svn
PPLexerChange.cpp
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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"
19 #include "clang/Lex/HeaderSearch.h"
21 #include "clang/Lex/MacroInfo.h"
22 #include "llvm/ADT/StringSwitch.h"
23 #include "llvm/Support/FileSystem.h"
24 #include "llvm/Support/MemoryBuffer.h"
25 #include "llvm/Support/Path.h"
26 using namespace clang;
27 
29 
30 //===----------------------------------------------------------------------===//
31 // Miscellaneous Methods.
32 //===----------------------------------------------------------------------===//
33 
34 /// isInPrimaryFile - Return true if we're in the top-level file, not in a
35 /// \#include. This looks through macro expansions and active _Pragma lexers.
37  if (IsFileLexer())
38  return IncludeMacroStack.empty();
39 
40  // If there are any stacked lexers, we're in a #include.
41  assert(IsFileLexer(IncludeMacroStack[0]) &&
42  "Top level include stack isn't our primary lexer?");
43  return std::none_of(
44  IncludeMacroStack.begin() + 1, IncludeMacroStack.end(),
45  [&](const IncludeStackInfo &ISI) -> bool { return IsFileLexer(ISI); });
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.
52  if (IsFileLexer())
53  return CurPPLexer;
54 
55  // Look for a stacked lexer.
56  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
57  if (IsFileLexer(ISI))
58  return ISI.ThePPLexer;
59  }
60  return nullptr;
61 }
62 
63 
64 //===----------------------------------------------------------------------===//
65 // Methods for Entering and Callbacks for leaving various contexts
66 //===----------------------------------------------------------------------===//
67 
68 /// EnterSourceFile - Add a source file to the top of the include stack and
69 /// start lexing tokens from it instead of the current buffer.
71  SourceLocation Loc) {
72  assert(!CurTokenLexer && "Cannot #include a file inside a macro!");
73  ++NumEnteredSourceFiles;
74 
75  if (MaxIncludeStackDepth < IncludeMacroStack.size())
76  MaxIncludeStackDepth = IncludeMacroStack.size();
77 
78  // Get the MemoryBuffer for this FID, if it fails, we fail.
79  bool Invalid = false;
80  const llvm::MemoryBuffer *InputFile =
81  getSourceManager().getBuffer(FID, Loc, &Invalid);
82  if (Invalid) {
83  SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID);
84  Diag(Loc, diag::err_pp_error_opening_file)
85  << std::string(SourceMgr.getBufferName(FileStart)) << "";
86  return true;
87  }
88 
89  if (isCodeCompletionEnabled() &&
90  SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) {
91  CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID);
92  CodeCompletionLoc =
93  CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset);
94  }
95 
96  EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
97  return false;
98 }
99 
100 /// EnterSourceFileWithLexer - Add a source file to the top of the include stack
101 /// and start lexing tokens from it instead of the current buffer.
102 void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
103  const DirectoryLookup *CurDir) {
104 
105  // Add the current lexer to the include stack.
106  if (CurPPLexer || CurTokenLexer)
107  PushIncludeMacroStack();
108 
109  CurLexer.reset(TheLexer);
110  CurPPLexer = TheLexer;
111  CurDirLookup = CurDir;
112  CurLexerSubmodule = nullptr;
113  if (CurLexerKind != CLK_LexAfterModuleImport)
114  CurLexerKind = CLK_Lexer;
115 
116  // Notify the client, if desired, that we are in a new source file.
117  if (Callbacks && !CurLexer->Is_PragmaLexer) {
118  SrcMgr::CharacteristicKind FileType =
119  SourceMgr.getFileCharacteristic(CurLexer->getFileLoc());
120 
121  Callbacks->FileChanged(CurLexer->getFileLoc(),
122  PPCallbacks::EnterFile, FileType);
123  }
124 }
125 
126 /// EnterMacro - Add a Macro to the top of the include stack and start lexing
127 /// tokens from it instead of the current buffer.
129  MacroInfo *Macro, MacroArgs *Args) {
130  std::unique_ptr<TokenLexer> TokLexer;
131  if (NumCachedTokenLexers == 0) {
132  TokLexer = llvm::make_unique<TokenLexer>(Tok, ILEnd, Macro, Args, *this);
133  } else {
134  TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
135  TokLexer->Init(Tok, ILEnd, Macro, Args);
136  }
137 
138  PushIncludeMacroStack();
139  CurDirLookup = nullptr;
140  CurTokenLexer = std::move(TokLexer);
141  if (CurLexerKind != CLK_LexAfterModuleImport)
142  CurLexerKind = CLK_TokenLexer;
143 }
144 
145 /// EnterTokenStream - Add a "macro" context to the top of the include stack,
146 /// which will cause the lexer to start returning the specified tokens.
147 ///
148 /// If DisableMacroExpansion is true, tokens lexed from the token stream will
149 /// not be subject to further macro expansion. Otherwise, these tokens will
150 /// be re-macro-expanded when/if expansion is enabled.
151 ///
152 /// If OwnsTokens is false, this method assumes that the specified stream of
153 /// tokens has a permanent owner somewhere, so they do not need to be copied.
154 /// If it is true, it assumes the array of tokens is allocated with new[] and
155 /// must be freed.
156 ///
157 void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
158  bool DisableMacroExpansion,
159  bool OwnsTokens) {
160  if (CurLexerKind == CLK_CachingLexer) {
161  if (CachedLexPos < CachedTokens.size()) {
162  // We're entering tokens into the middle of our cached token stream. We
163  // can't represent that, so just insert the tokens into the buffer.
164  CachedTokens.insert(CachedTokens.begin() + CachedLexPos,
165  Toks, Toks + NumToks);
166  if (OwnsTokens)
167  delete [] Toks;
168  return;
169  }
170 
171  // New tokens are at the end of the cached token sequnece; insert the
172  // token stream underneath the caching lexer.
173  ExitCachingLexMode();
174  EnterTokenStream(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
175  EnterCachingLexMode();
176  return;
177  }
178 
179  // Create a macro expander to expand from the specified token stream.
180  std::unique_ptr<TokenLexer> TokLexer;
181  if (NumCachedTokenLexers == 0) {
182  TokLexer = llvm::make_unique<TokenLexer>(
183  Toks, NumToks, DisableMacroExpansion, OwnsTokens, *this);
184  } else {
185  TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
186  TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
187  }
188 
189  // Save our current state.
190  PushIncludeMacroStack();
191  CurDirLookup = nullptr;
192  CurTokenLexer = std::move(TokLexer);
193  if (CurLexerKind != CLK_LexAfterModuleImport)
194  CurLexerKind = CLK_TokenLexer;
195 }
196 
197 /// Compute the relative path that names the given file relative to
198 /// the given directory.
199 static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
200  const FileEntry *File,
202  Result.clear();
203 
204  StringRef FilePath = File->getDir()->getName();
205  StringRef Path = FilePath;
206  while (!Path.empty()) {
207  if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) {
208  if (CurDir == Dir) {
209  Result = FilePath.substr(Path.size());
210  llvm::sys::path::append(Result,
211  llvm::sys::path::filename(File->getName()));
212  return;
213  }
214  }
215 
216  Path = llvm::sys::path::parent_path(Path);
217  }
218 
219  Result = File->getName();
220 }
221 
222 void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
223  if (CurTokenLexer) {
224  CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
225  return;
226  }
227  if (CurLexer) {
228  CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
229  return;
230  }
231  // FIXME: Handle other kinds of lexers? It generally shouldn't matter,
232  // but it might if they're empty?
233 }
234 
235 /// Determine the location to use as the end of the buffer for a lexer.
236 ///
237 /// If the file ends with a newline, form the EOF token on the newline itself,
238 /// rather than "on the line following it", which doesn't exist. This makes
239 /// diagnostics relating to the end of file include the last file that the user
240 /// actually typed, which is goodness.
241 const char *Preprocessor::getCurLexerEndPos() {
242  const char *EndPos = CurLexer->BufferEnd;
243  if (EndPos != CurLexer->BufferStart &&
244  (EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
245  --EndPos;
246 
247  // Handle \n\r and \r\n:
248  if (EndPos != CurLexer->BufferStart &&
249  (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
250  EndPos[-1] != EndPos[0])
251  --EndPos;
252  }
253 
254  return EndPos;
255 }
256 
258  const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
259  if (Mod.getUmbrellaHeader())
260  SubMods.push_back(&Mod);
261  for (auto *M : Mod.submodules())
263 }
264 
265 void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
266  assert(Mod.getUmbrellaHeader() && "Module must use umbrella header");
267  SourceLocation StartLoc =
268  SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
269  if (getDiagnostics().isIgnored(diag::warn_uncovered_module_header, StartLoc))
270  return;
271 
272  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
273  const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
274  llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
275  std::error_code EC;
276  for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
277  End;
278  Entry != End && !EC; Entry.increment(EC)) {
279  using llvm::StringSwitch;
280 
281  // Check whether this entry has an extension typically associated with
282  // headers.
283  if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path()))
284  .Cases(".h", ".H", ".hh", ".hpp", true)
285  .Default(false))
286  continue;
287 
288  if (const FileEntry *Header = getFileManager().getFile(Entry->path()))
289  if (!getSourceManager().hasFileInfo(Header)) {
290  if (!ModMap.isHeaderInUnavailableModule(Header)) {
291  // Find the relative path that would access this header.
292  SmallString<128> RelativePath;
293  computeRelativePath(FileMgr, Dir, Header, RelativePath);
294  Diag(StartLoc, diag::warn_uncovered_module_header)
295  << Mod.getFullModuleName() << RelativePath;
296  }
297  }
298  }
299 }
300 
301 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of
302 /// the current file. This either returns the EOF token or pops a level off
303 /// the include stack and keeps going.
304 bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
305  assert(!CurTokenLexer &&
306  "Ending a file when currently in a macro!");
307 
308  // If we have an unclosed module region from a pragma at the end of a
309  // module, complain and close it now.
310  const bool LeavingSubmodule = CurLexer && CurLexerSubmodule;
311  if ((LeavingSubmodule || IncludeMacroStack.empty()) &&
312  !BuildingSubmoduleStack.empty() &&
313  BuildingSubmoduleStack.back().IsPragma) {
314  Diag(BuildingSubmoduleStack.back().ImportLoc,
315  diag::err_pp_module_begin_without_module_end);
316  Module *M = LeaveSubmodule(/*ForPragma*/true);
317 
318  Result.startToken();
319  const char *EndPos = getCurLexerEndPos();
320  CurLexer->BufferPtr = EndPos;
321  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
322  Result.setAnnotationEndLoc(Result.getLocation());
323  Result.setAnnotationValue(M);
324  return true;
325  }
326 
327  // See if this file had a controlling macro.
328  if (CurPPLexer) { // Not ending a macro, ignore it.
329  if (const IdentifierInfo *ControllingMacro =
330  CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
331  // Okay, this has a controlling macro, remember in HeaderFileInfo.
332  if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
333  HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
334  if (MacroInfo *MI =
335  getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro)))
336  MI->setUsedForHeaderGuard(true);
337  if (const IdentifierInfo *DefinedMacro =
338  CurPPLexer->MIOpt.GetDefinedMacro()) {
339  if (!isMacroDefined(ControllingMacro) &&
340  DefinedMacro != ControllingMacro &&
341  HeaderInfo.FirstTimeLexingFile(FE)) {
342 
343  // If the edit distance between the two macros is more than 50%,
344  // DefinedMacro may not be header guard, or can be header guard of
345  // another header file. Therefore, it maybe defining something
346  // completely different. This can be observed in the wild when
347  // handling feature macros or header guards in different files.
348 
349  const StringRef ControllingMacroName = ControllingMacro->getName();
350  const StringRef DefinedMacroName = DefinedMacro->getName();
351  const size_t MaxHalfLength = std::max(ControllingMacroName.size(),
352  DefinedMacroName.size()) / 2;
353  const unsigned ED = ControllingMacroName.edit_distance(
354  DefinedMacroName, true, MaxHalfLength);
355  if (ED <= MaxHalfLength) {
356  // Emit a warning for a bad header guard.
357  Diag(CurPPLexer->MIOpt.GetMacroLocation(),
358  diag::warn_header_guard)
359  << CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro;
360  Diag(CurPPLexer->MIOpt.GetDefinedLocation(),
361  diag::note_header_guard)
362  << CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro
363  << ControllingMacro
365  CurPPLexer->MIOpt.GetDefinedLocation(),
366  ControllingMacro->getName());
367  }
368  }
369  }
370  }
371  }
372  }
373 
374  // Complain about reaching a true EOF within arc_cf_code_audited.
375  // We don't want to complain about reaching the end of a macro
376  // instantiation or a _Pragma.
377  if (PragmaARCCFCodeAuditedLoc.isValid() &&
378  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
379  Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited);
380 
381  // Recover by leaving immediately.
382  PragmaARCCFCodeAuditedLoc = SourceLocation();
383  }
384 
385  // Complain about reaching a true EOF within assume_nonnull.
386  // We don't want to complain about reaching the end of a macro
387  // instantiation or a _Pragma.
388  if (PragmaAssumeNonNullLoc.isValid() &&
389  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
390  Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
391 
392  // Recover by leaving immediately.
393  PragmaAssumeNonNullLoc = SourceLocation();
394  }
395 
396  bool LeavingPCHThroughHeader = false;
397 
398  // If this is a #include'd file, pop it off the include stack and continue
399  // lexing the #includer file.
400  if (!IncludeMacroStack.empty()) {
401 
402  // If we lexed the code-completion file, act as if we reached EOF.
403  if (isCodeCompletionEnabled() && CurPPLexer &&
404  SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
405  CodeCompletionFileLoc) {
406  assert(CurLexer && "Got EOF but no current lexer set!");
407  Result.startToken();
408  CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
409  CurLexer.reset();
410 
411  CurPPLexer = nullptr;
412  recomputeCurLexerKind();
413  return true;
414  }
415 
416  if (!isEndOfMacro && CurPPLexer &&
417  SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
418  // Notify SourceManager to record the number of FileIDs that were created
419  // during lexing of the #include'd file.
420  unsigned NumFIDs =
421  SourceMgr.local_sloc_entry_size() -
422  CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
423  SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
424  }
425 
426  bool ExitedFromPredefinesFile = false;
427  FileID ExitedFID;
428  if (!isEndOfMacro && CurPPLexer) {
429  ExitedFID = CurPPLexer->getFileID();
430 
431  assert(PredefinesFileID.isValid() &&
432  "HandleEndOfFile is called before PredefinesFileId is set");
433  ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
434  }
435 
436  if (LeavingSubmodule) {
437  // We're done with this submodule.
438  Module *M = LeaveSubmodule(/*ForPragma*/false);
439 
440  // Notify the parser that we've left the module.
441  const char *EndPos = getCurLexerEndPos();
442  Result.startToken();
443  CurLexer->BufferPtr = EndPos;
444  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
445  Result.setAnnotationEndLoc(Result.getLocation());
446  Result.setAnnotationValue(M);
447  }
448 
449  bool FoundPCHThroughHeader = false;
450  if (CurPPLexer && creatingPCHWithThroughHeader() &&
451  isPCHThroughHeader(
452  SourceMgr.getFileEntryForID(CurPPLexer->getFileID())))
453  FoundPCHThroughHeader = true;
454 
455  // We're done with the #included file.
456  RemoveTopOfLexerStack();
457 
458  // Propagate info about start-of-line/leading white-space/etc.
459  PropagateLineStartLeadingSpaceInfo(Result);
460 
461  // Notify the client, if desired, that we are in a new source file.
462  if (Callbacks && !isEndOfMacro && CurPPLexer) {
463  SrcMgr::CharacteristicKind FileType =
464  SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
465  Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
466  PPCallbacks::ExitFile, FileType, ExitedFID);
467  }
468 
469  // Restore conditional stack from the preamble right after exiting from the
470  // predefines file.
471  if (ExitedFromPredefinesFile)
472  replayPreambleConditionalStack();
473 
474  if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader &&
475  (isInPrimaryFile() ||
476  CurPPLexer->getFileID() == getPredefinesFileID())) {
477  // Leaving the through header. Continue directly to end of main file
478  // processing.
479  LeavingPCHThroughHeader = true;
480  } else {
481  // Client should lex another token unless we generated an EOM.
482  return LeavingSubmodule;
483  }
484  }
485 
486  // If this is the end of the main file, form an EOF token.
487  assert(CurLexer && "Got EOF but no current lexer set!");
488  const char *EndPos = getCurLexerEndPos();
489  Result.startToken();
490  CurLexer->BufferPtr = EndPos;
491  CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
492 
493  if (isCodeCompletionEnabled()) {
494  // Inserting the code-completion point increases the source buffer by 1,
495  // but the main FileID was created before inserting the point.
496  // Compensate by reducing the EOF location by 1, otherwise the location
497  // will point to the next FileID.
498  // FIXME: This is hacky, the code-completion point should probably be
499  // inserted before the main FileID is created.
500  if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
501  Result.setLocation(Result.getLocation().getLocWithOffset(-1));
502  }
503 
504  if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) {
505  // Reached the end of the compilation without finding the through header.
506  Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen)
507  << PPOpts->PCHThroughHeader << 0;
508  }
509 
510  if (!isIncrementalProcessingEnabled())
511  // We're done with lexing.
512  CurLexer.reset();
513 
514  if (!isIncrementalProcessingEnabled())
515  CurPPLexer = nullptr;
516 
517  if (TUKind == TU_Complete) {
518  // This is the end of the top-level file. 'WarnUnusedMacroLocs' has
519  // collected all macro locations that we need to warn because they are not
520  // used.
521  for (WarnUnusedMacroLocsTy::iterator
522  I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
523  I!=E; ++I)
524  Diag(*I, diag::pp_macro_not_used);
525  }
526 
527  // If we are building a module that has an umbrella header, make sure that
528  // each of the headers within the directory, including all submodules, is
529  // covered by the umbrella header was actually included by the umbrella
530  // header.
531  if (Module *Mod = getCurrentModule()) {
534  for (auto *M : AllMods)
535  diagnoseMissingHeaderInUmbrellaDir(*M);
536  }
537 
538  return true;
539 }
540 
541 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
542 /// hits the end of its token stream.
544  assert(CurTokenLexer && !CurPPLexer &&
545  "Ending a macro when currently in a #include file!");
546 
547  if (!MacroExpandingLexersStack.empty() &&
548  MacroExpandingLexersStack.back().first == CurTokenLexer.get())
549  removeCachedMacroExpandedTokensOfLastLexer();
550 
551  // Delete or cache the now-dead macro expander.
552  if (NumCachedTokenLexers == TokenLexerCacheSize)
553  CurTokenLexer.reset();
554  else
555  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
556 
557  // Handle this like a #include file being popped off the stack.
558  return HandleEndOfFile(Result, true);
559 }
560 
561 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
562 /// lexer stack. This should only be used in situations where the current
563 /// state of the top-of-stack lexer is unknown.
565  assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
566 
567  if (CurTokenLexer) {
568  // Delete or cache the now-dead macro expander.
569  if (NumCachedTokenLexers == TokenLexerCacheSize)
570  CurTokenLexer.reset();
571  else
572  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
573  }
574 
575  PopIncludeMacroStack();
576 }
577 
578 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a
579 /// comment (/##/) in microsoft mode, this method handles updating the current
580 /// state, returning the token on the next source line.
582  assert(CurTokenLexer && !CurPPLexer &&
583  "Pasted comment can only be formed from macro");
584  // We handle this by scanning for the closest real lexer, switching it to
585  // raw mode and preprocessor mode. This will cause it to return \n as an
586  // explicit EOD token.
587  PreprocessorLexer *FoundLexer = nullptr;
588  bool LexerWasInPPMode = false;
589  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
590  if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
591 
592  // Once we find a real lexer, mark it as raw mode (disabling macro
593  // expansions) and preprocessor mode (return EOD). We know that the lexer
594  // was *not* in raw mode before, because the macro that the comment came
595  // from was expanded. However, it could have already been in preprocessor
596  // mode (#if COMMENT) in which case we have to return it to that mode and
597  // return EOD.
598  FoundLexer = ISI.ThePPLexer;
599  FoundLexer->LexingRawMode = true;
600  LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
601  FoundLexer->ParsingPreprocessorDirective = true;
602  break;
603  }
604 
605  // Okay, we either found and switched over the lexer, or we didn't find a
606  // lexer. In either case, finish off the macro the comment came from, getting
607  // the next token.
608  if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
609 
610  // Discarding comments as long as we don't have EOF or EOD. This 'comments
611  // out' the rest of the line, including any tokens that came from other macros
612  // that were active, as in:
613  // #define submacro a COMMENT b
614  // submacro c
615  // which should lex to 'a' only: 'b' and 'c' should be removed.
616  while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
617  Lex(Tok);
618 
619  // If we got an eod token, then we successfully found the end of the line.
620  if (Tok.is(tok::eod)) {
621  assert(FoundLexer && "Can't get end of line without an active lexer");
622  // Restore the lexer back to normal mode instead of raw mode.
623  FoundLexer->LexingRawMode = false;
624 
625  // If the lexer was already in preprocessor mode, just return the EOD token
626  // to finish the preprocessor line.
627  if (LexerWasInPPMode) return;
628 
629  // Otherwise, switch out of PP mode and return the next lexed token.
630  FoundLexer->ParsingPreprocessorDirective = false;
631  return Lex(Tok);
632  }
633 
634  // If we got an EOF token, then we reached the end of the token stream but
635  // didn't find an explicit \n. This can only happen if there was no lexer
636  // active (an active lexer would return EOD at EOF if there was no \n in
637  // preprocessor directive mode), so just return EOF as our token.
638  assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
639 }
640 
642  bool ForPragma) {
643  if (!getLangOpts().ModulesLocalVisibility) {
644  // Just track that we entered this submodule.
645  BuildingSubmoduleStack.push_back(
646  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
647  PendingModuleMacroNames.size()));
648  return;
649  }
650 
651  // Resolve as much of the module definition as we can now, before we enter
652  // one of its headers.
653  // FIXME: Can we enable Complain here?
654  // FIXME: Can we do this when local visibility is disabled?
655  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
656  ModMap.resolveExports(M, /*Complain=*/false);
657  ModMap.resolveUses(M, /*Complain=*/false);
658  ModMap.resolveConflicts(M, /*Complain=*/false);
659 
660  // If this is the first time we've entered this module, set up its state.
661  auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
662  auto &State = R.first->second;
663  bool FirstTime = R.second;
664  if (FirstTime) {
665  // Determine the set of starting macros for this submodule; take these
666  // from the "null" module (the predefines buffer).
667  //
668  // FIXME: If we have local visibility but not modules enabled, the
669  // NullSubmoduleState is polluted by #defines in the top-level source
670  // file.
671  auto &StartingMacros = NullSubmoduleState.Macros;
672 
673  // Restore to the starting state.
674  // FIXME: Do this lazily, when each macro name is first referenced.
675  for (auto &Macro : StartingMacros) {
676  // Skip uninteresting macros.
677  if (!Macro.second.getLatest() &&
678  Macro.second.getOverriddenMacros().empty())
679  continue;
680 
681  MacroState MS(Macro.second.getLatest());
682  MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
683  State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
684  }
685  }
686 
687  // Track that we entered this module.
688  BuildingSubmoduleStack.push_back(
689  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
690  PendingModuleMacroNames.size()));
691 
692  // Switch to this submodule as the current submodule.
693  CurSubmoduleState = &State;
694 
695  // This module is visible to itself.
696  if (FirstTime)
697  makeModuleVisible(M, ImportLoc);
698 }
699 
700 bool Preprocessor::needModuleMacros() const {
701  // If we're not within a submodule, we never need to create ModuleMacros.
702  if (BuildingSubmoduleStack.empty())
703  return false;
704  // If we are tracking module macro visibility even for textually-included
705  // headers, we need ModuleMacros.
706  if (getLangOpts().ModulesLocalVisibility)
707  return true;
708  // Otherwise, we only need module macros if we're actually compiling a module
709  // interface.
710  return getLangOpts().isCompilingModule();
711 }
712 
714  if (BuildingSubmoduleStack.empty() ||
715  BuildingSubmoduleStack.back().IsPragma != ForPragma) {
716  assert(ForPragma && "non-pragma module enter/leave mismatch");
717  return nullptr;
718  }
719 
720  auto &Info = BuildingSubmoduleStack.back();
721 
722  Module *LeavingMod = Info.M;
723  SourceLocation ImportLoc = Info.ImportLoc;
724 
725  if (!needModuleMacros() ||
726  (!getLangOpts().ModulesLocalVisibility &&
727  LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
728  // If we don't need module macros, or this is not a module for which we
729  // are tracking macro visibility, don't build any, and preserve the list
730  // of pending names for the surrounding submodule.
731  BuildingSubmoduleStack.pop_back();
732  makeModuleVisible(LeavingMod, ImportLoc);
733  return LeavingMod;
734  }
735 
736  // Create ModuleMacros for any macros defined in this submodule.
737  llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
738  for (unsigned I = Info.OuterPendingModuleMacroNames;
739  I != PendingModuleMacroNames.size(); ++I) {
740  auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
741  if (!VisitedMacros.insert(II).second)
742  continue;
743 
744  auto MacroIt = CurSubmoduleState->Macros.find(II);
745  if (MacroIt == CurSubmoduleState->Macros.end())
746  continue;
747  auto &Macro = MacroIt->second;
748 
749  // Find the starting point for the MacroDirective chain in this submodule.
750  MacroDirective *OldMD = nullptr;
751  auto *OldState = Info.OuterSubmoduleState;
752  if (getLangOpts().ModulesLocalVisibility)
753  OldState = &NullSubmoduleState;
754  if (OldState && OldState != CurSubmoduleState) {
755  // FIXME: It'd be better to start at the state from when we most recently
756  // entered this submodule, but it doesn't really matter.
757  auto &OldMacros = OldState->Macros;
758  auto OldMacroIt = OldMacros.find(II);
759  if (OldMacroIt == OldMacros.end())
760  OldMD = nullptr;
761  else
762  OldMD = OldMacroIt->second.getLatest();
763  }
764 
765  // This module may have exported a new macro. If so, create a ModuleMacro
766  // representing that fact.
767  bool ExplicitlyPublic = false;
768  for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
769  assert(MD && "broken macro directive chain");
770 
771  if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
772  // The latest visibility directive for a name in a submodule affects
773  // all the directives that come before it.
774  if (VisMD->isPublic())
775  ExplicitlyPublic = true;
776  else if (!ExplicitlyPublic)
777  // Private with no following public directive: not exported.
778  break;
779  } else {
780  MacroInfo *Def = nullptr;
781  if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
782  Def = DefMD->getInfo();
783 
784  // FIXME: Issue a warning if multiple headers for the same submodule
785  // define a macro, rather than silently ignoring all but the first.
786  bool IsNew;
787  // Don't bother creating a module macro if it would represent a #undef
788  // that doesn't override anything.
789  if (Def || !Macro.getOverriddenMacros().empty())
790  addModuleMacro(LeavingMod, II, Def,
791  Macro.getOverriddenMacros(), IsNew);
792 
793  if (!getLangOpts().ModulesLocalVisibility) {
794  // This macro is exposed to the rest of this compilation as a
795  // ModuleMacro; we don't need to track its MacroDirective any more.
796  Macro.setLatest(nullptr);
797  Macro.setOverriddenMacros(*this, {});
798  }
799  break;
800  }
801  }
802  }
803  PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
804 
805  // FIXME: Before we leave this submodule, we should parse all the other
806  // headers within it. Otherwise, we're left with an inconsistent state
807  // where we've made the module visible but don't yet have its complete
808  // contents.
809 
810  // Put back the outer module's state, if we're tracking it.
811  if (getLangOpts().ModulesLocalVisibility)
812  CurSubmoduleState = Info.OuterSubmoduleState;
813 
814  BuildingSubmoduleStack.pop_back();
815 
816  // A nested #include makes the included submodule visible.
817  makeModuleVisible(LeavingMod, ImportLoc);
818  return LeavingMod;
819 }
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
Lexer - This provides a simple interface that turns a text buffer into a stream of tokens...
Definition: Lexer.h:77
SourceLocation getLocWithOffset(int Offset) const
Return a source location with the specified offset from this SourceLocation.
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:122
Defines the clang::FileManager interface and associated types.
bool is(tok::TokenKind K) const
is/isNot - Predicates to check if this token is a specific kind, as in "if (Tok.is(tok::l_brace)) {...
Definition: Token.h:95
Defines the SourceManager interface.
bool isInPrimaryFile() const
Return true if we&#39;re in the top-level file, not in a #include.
Defines the clang::MacroInfo and clang::MacroDirective classes.
bool resolveUses(Module *Mod, bool Complain)
Resolve all of the unresolved uses in the given module.
Definition: ModuleMap.cpp:1260
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:78
const MacroDirective * getPrevious() const
Get previous definition of the macro with the same name.
Definition: MacroInfo.h:329
bool HandleEndOfTokenLexer(Token &Result)
Callback invoked when the current TokenLexer hits the end of its token stream.
One of these records is kept for each identifier that is lexed.
A directive for a defined macro or a macro imported from a module.
Definition: MacroInfo.h:407
bool ParsingPreprocessorDirective
True when parsing #XXX; turns &#39;\n&#39; into a tok::eod token.
bool resolveConflicts(Module *Mod, bool Complain)
Resolve all of the unresolved conflicts in the given module.
Definition: ModuleMap.cpp:1273
LineState State
void EnterSubmodule(Module *M, SourceLocation ImportLoc, bool ForPragma)
Module * LeaveSubmodule(bool ForPragma)
Header getUmbrellaHeader() const
Retrieve the header that serves as the umbrella header for this module.
Definition: Module.h:483
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
Describes a module or submodule.
Definition: Module.h:65
StringRef getTopLevelModuleName() const
Retrieve the name of the top-level module.
Definition: Module.h:461
std::string getFullModuleName(bool AllowStringLiterals=false) const
Retrieve the full name of this module, including the path from its top-level module.
Definition: Module.cpp:214
const FormatToken & Tok
const DirectoryEntry * getDirectory(StringRef DirName, bool CacheFailure=true)
Lookup, cache, and verify the specified directory (real or virtual).
const DirectoryEntry * Entry
Definition: Module.h:162
void setAnnotationValue(void *val)
Definition: Token.h:228
bool LexingRawMode
True if in raw mode.
SourceLocation End
MacroArgs - An instance of this class captures information about the formal arguments specified to a ...
Definition: MacroArgs.h:30
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:124
Defines the clang::Preprocessor interface.
void HandleMicrosoftCommentPaste(Token &Tok)
When the macro expander pastes together a comment (/##/) in Microsoft mode, this method handles updat...
bool resolveExports(Module *Mod, bool Complain)
Resolve all of the unresolved exports in the given module.
Definition: ModuleMap.cpp:1247
static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir, const FileEntry *File, SmallString< 128 > &Result)
Compute the relative path that names the given file relative to the given directory.
bool HandleEndOfFile(Token &Result, bool isEndOfMacro=false)
Callback invoked when the lexer hits the end of the current file.
The result type of a method or function.
DirectoryLookup - This class represents one entry in the search list that specifies the search order ...
const DirectoryEntry * getDir() const
Return the directory the file lives in.
Definition: FileManager.h:96
Encapsulates changes to the "macros namespace" (the location where the macro name became active...
Definition: MacroInfo.h:291
Encodes a location in the source.
StringRef getName() const
Definition: FileManager.h:86
void setAnnotationEndLoc(SourceLocation L)
Definition: Token.h:142
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:60
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
bool isNot(tok::TokenKind K) const
Definition: Token.h:96
bool EnterSourceFile(FileID FID, const DirectoryLookup *Dir, SourceLocation Loc)
Add a source file to the top of the include stack and start lexing tokens from it instead of the curr...
Dataflow Directional Tag Classes.
llvm::iterator_range< submodule_iterator > submodules()
Definition: Module.h:561
Encapsulates the data about a macro definition (e.g.
Definition: MacroInfo.h:40
DirectoryName getUmbrellaDir() const
Retrieve the directory for which this module serves as the umbrella.
Definition: Module.cpp:239
Cached information about one directory (either on disk or in the virtual file system).
Definition: FileManager.h:46
static void collectAllSubModulesWithUmbrellaHeader(const Module &Mod, SmallVectorImpl< const Module *> &SubMods)
static bool isMacroDefined(const Sema &S, SourceLocation Loc, StringRef Name)
void RemoveTopOfLexerStack()
Pop the current lexer/macro exp off the top of the lexer stack.
static FixItHint CreateReplacement(CharSourceRange RemoveRange, StringRef Code)
Create a code modification hint that replaces the given source range with the given code string...
Definition: Diagnostic.h:129
The translation unit is a complete translation unit.
Definition: LangOptions.h:356
bool isHeaderInUnavailableModule(const FileEntry *Header) const
Determine whether the given header is part of a module marked &#39;unavailable&#39;.
Definition: ModuleMap.cpp:666
__DEVICE__ int max(int __a, int __b)
void EnterMacro(Token &Tok, SourceLocation ILEnd, MacroInfo *Macro, MacroArgs *Args)
Add a Macro to the top of the include stack and start lexing tokens from it instead of the current bu...
void setLocation(SourceLocation L)
Definition: Token.h:132
PreprocessorLexer * getCurrentFileLexer() const
Return the current file lexer being lexed from.
void startToken()
Reset all flags to cleared.
Definition: Token.h:169
StringRef getName() const
Definition: FileManager.h:52