clang  9.0.0svn
PPLexerChange.cpp
Go to the documentation of this file.
1 //===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements pieces of the Preprocessor interface that manage the
10 // current lexer stack.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Lex/Preprocessor.h"
18 #include "clang/Lex/HeaderSearch.h"
20 #include "clang/Lex/MacroInfo.h"
21 #include "llvm/ADT/StringSwitch.h"
22 #include "llvm/Support/FileSystem.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 #include "llvm/Support/Path.h"
25 using namespace clang;
26 
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.
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  return std::none_of(
43  IncludeMacroStack.begin() + 1, IncludeMacroStack.end(),
44  [&](const IncludeStackInfo &ISI) -> bool { return IsFileLexer(ISI); });
45 }
46 
47 /// getCurrentLexer - Return the current file lexer being lexed from. Note
48 /// that this ignores any potentially active macro expansions and _Pragma
49 /// expansions going on at the time.
51  if (IsFileLexer())
52  return CurPPLexer;
53 
54  // Look for a stacked lexer.
55  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
56  if (IsFileLexer(ISI))
57  return ISI.ThePPLexer;
58  }
59  return nullptr;
60 }
61 
62 
63 //===----------------------------------------------------------------------===//
64 // Methods for Entering and Callbacks for leaving various contexts
65 //===----------------------------------------------------------------------===//
66 
67 /// EnterSourceFile - Add a source file to the top of the include stack and
68 /// start lexing tokens from it instead of the current buffer.
70  SourceLocation Loc) {
71  assert(!CurTokenLexer && "Cannot #include a file inside a macro!");
72  ++NumEnteredSourceFiles;
73 
74  if (MaxIncludeStackDepth < IncludeMacroStack.size())
75  MaxIncludeStackDepth = IncludeMacroStack.size();
76 
77  // Get the MemoryBuffer for this FID, if it fails, we fail.
78  bool Invalid = false;
79  const llvm::MemoryBuffer *InputFile =
80  getSourceManager().getBuffer(FID, Loc, &Invalid);
81  if (Invalid) {
82  SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID);
83  Diag(Loc, diag::err_pp_error_opening_file)
84  << std::string(SourceMgr.getBufferName(FileStart)) << "";
85  return true;
86  }
87 
88  if (isCodeCompletionEnabled() &&
89  SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) {
90  CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID);
91  CodeCompletionLoc =
92  CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset);
93  }
94 
95  EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
96  return false;
97 }
98 
99 /// EnterSourceFileWithLexer - Add a source file to the top of the include stack
100 /// and start lexing tokens from it instead of the current buffer.
101 void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
102  const DirectoryLookup *CurDir) {
103 
104  // Add the current lexer to the include stack.
105  if (CurPPLexer || CurTokenLexer)
106  PushIncludeMacroStack();
107 
108  CurLexer.reset(TheLexer);
109  CurPPLexer = TheLexer;
110  CurDirLookup = CurDir;
111  CurLexerSubmodule = nullptr;
112  if (CurLexerKind != CLK_LexAfterModuleImport)
113  CurLexerKind = CLK_Lexer;
114 
115  // Notify the client, if desired, that we are in a new source file.
116  if (Callbacks && !CurLexer->Is_PragmaLexer) {
117  SrcMgr::CharacteristicKind FileType =
118  SourceMgr.getFileCharacteristic(CurLexer->getFileLoc());
119 
120  Callbacks->FileChanged(CurLexer->getFileLoc(),
121  PPCallbacks::EnterFile, FileType);
122  }
123 }
124 
125 /// EnterMacro - Add a Macro to the top of the include stack and start lexing
126 /// tokens from it instead of the current buffer.
128  MacroInfo *Macro, MacroArgs *Args) {
129  std::unique_ptr<TokenLexer> TokLexer;
130  if (NumCachedTokenLexers == 0) {
131  TokLexer = llvm::make_unique<TokenLexer>(Tok, ILEnd, Macro, Args, *this);
132  } else {
133  TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
134  TokLexer->Init(Tok, ILEnd, Macro, Args);
135  }
136 
137  PushIncludeMacroStack();
138  CurDirLookup = nullptr;
139  CurTokenLexer = std::move(TokLexer);
140  if (CurLexerKind != CLK_LexAfterModuleImport)
141  CurLexerKind = CLK_TokenLexer;
142 }
143 
144 /// EnterTokenStream - Add a "macro" context to the top of the include stack,
145 /// which will cause the lexer to start returning the specified tokens.
146 ///
147 /// If DisableMacroExpansion is true, tokens lexed from the token stream will
148 /// not be subject to further macro expansion. Otherwise, these tokens will
149 /// be re-macro-expanded when/if expansion is enabled.
150 ///
151 /// If OwnsTokens is false, this method assumes that the specified stream of
152 /// tokens has a permanent owner somewhere, so they do not need to be copied.
153 /// If it is true, it assumes the array of tokens is allocated with new[] and
154 /// must be freed.
155 ///
156 void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
157  bool DisableMacroExpansion,
158  bool OwnsTokens) {
159  if (CurLexerKind == CLK_CachingLexer) {
160  if (CachedLexPos < CachedTokens.size()) {
161  // We're entering tokens into the middle of our cached token stream. We
162  // can't represent that, so just insert the tokens into the buffer.
163  CachedTokens.insert(CachedTokens.begin() + CachedLexPos,
164  Toks, Toks + NumToks);
165  if (OwnsTokens)
166  delete [] Toks;
167  return;
168  }
169 
170  // New tokens are at the end of the cached token sequnece; insert the
171  // token stream underneath the caching lexer.
172  ExitCachingLexMode();
173  EnterTokenStream(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
174  EnterCachingLexMode();
175  return;
176  }
177 
178  // Create a macro expander to expand from the specified token stream.
179  std::unique_ptr<TokenLexer> TokLexer;
180  if (NumCachedTokenLexers == 0) {
181  TokLexer = llvm::make_unique<TokenLexer>(
182  Toks, NumToks, DisableMacroExpansion, OwnsTokens, *this);
183  } else {
184  TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
185  TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
186  }
187 
188  // Save our current state.
189  PushIncludeMacroStack();
190  CurDirLookup = nullptr;
191  CurTokenLexer = std::move(TokLexer);
192  if (CurLexerKind != CLK_LexAfterModuleImport)
193  CurLexerKind = CLK_TokenLexer;
194 }
195 
196 /// Compute the relative path that names the given file relative to
197 /// the given directory.
198 static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
199  const FileEntry *File,
201  Result.clear();
202 
203  StringRef FilePath = File->getDir()->getName();
204  StringRef Path = FilePath;
205  while (!Path.empty()) {
206  if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) {
207  if (CurDir == Dir) {
208  Result = FilePath.substr(Path.size());
209  llvm::sys::path::append(Result,
210  llvm::sys::path::filename(File->getName()));
211  return;
212  }
213  }
214 
215  Path = llvm::sys::path::parent_path(Path);
216  }
217 
218  Result = File->getName();
219 }
220 
221 void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
222  if (CurTokenLexer) {
223  CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
224  return;
225  }
226  if (CurLexer) {
227  CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
228  return;
229  }
230  // FIXME: Handle other kinds of lexers? It generally shouldn't matter,
231  // but it might if they're empty?
232 }
233 
234 /// Determine the location to use as the end of the buffer for a lexer.
235 ///
236 /// If the file ends with a newline, form the EOF token on the newline itself,
237 /// rather than "on the line following it", which doesn't exist. This makes
238 /// diagnostics relating to the end of file include the last file that the user
239 /// actually typed, which is goodness.
240 const char *Preprocessor::getCurLexerEndPos() {
241  const char *EndPos = CurLexer->BufferEnd;
242  if (EndPos != CurLexer->BufferStart &&
243  (EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
244  --EndPos;
245 
246  // Handle \n\r and \r\n:
247  if (EndPos != CurLexer->BufferStart &&
248  (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
249  EndPos[-1] != EndPos[0])
250  --EndPos;
251  }
252 
253  return EndPos;
254 }
255 
257  const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
258  if (Mod.getUmbrellaHeader())
259  SubMods.push_back(&Mod);
260  for (auto *M : Mod.submodules())
262 }
263 
264 void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
265  assert(Mod.getUmbrellaHeader() && "Module must use umbrella header");
266  SourceLocation StartLoc =
267  SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
268  if (getDiagnostics().isIgnored(diag::warn_uncovered_module_header, StartLoc))
269  return;
270 
271  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
272  const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
273  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
274  std::error_code EC;
275  for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
276  End;
277  Entry != End && !EC; Entry.increment(EC)) {
278  using llvm::StringSwitch;
279 
280  // Check whether this entry has an extension typically associated with
281  // headers.
282  if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path()))
283  .Cases(".h", ".H", ".hh", ".hpp", true)
284  .Default(false))
285  continue;
286 
287  if (const FileEntry *Header = getFileManager().getFile(Entry->path()))
288  if (!getSourceManager().hasFileInfo(Header)) {
289  if (!ModMap.isHeaderInUnavailableModule(Header)) {
290  // Find the relative path that would access this header.
291  SmallString<128> RelativePath;
292  computeRelativePath(FileMgr, Dir, Header, RelativePath);
293  Diag(StartLoc, diag::warn_uncovered_module_header)
294  << Mod.getFullModuleName() << RelativePath;
295  }
296  }
297  }
298 }
299 
300 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of
301 /// the current file. This either returns the EOF token or pops a level off
302 /// the include stack and keeps going.
303 bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
304  assert(!CurTokenLexer &&
305  "Ending a file when currently in a macro!");
306 
307  // If we have an unclosed module region from a pragma at the end of a
308  // module, complain and close it now.
309  const bool LeavingSubmodule = CurLexer && CurLexerSubmodule;
310  if ((LeavingSubmodule || IncludeMacroStack.empty()) &&
311  !BuildingSubmoduleStack.empty() &&
312  BuildingSubmoduleStack.back().IsPragma) {
313  Diag(BuildingSubmoduleStack.back().ImportLoc,
314  diag::err_pp_module_begin_without_module_end);
315  Module *M = LeaveSubmodule(/*ForPragma*/true);
316 
317  Result.startToken();
318  const char *EndPos = getCurLexerEndPos();
319  CurLexer->BufferPtr = EndPos;
320  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
321  Result.setAnnotationEndLoc(Result.getLocation());
322  Result.setAnnotationValue(M);
323  return true;
324  }
325 
326  // See if this file had a controlling macro.
327  if (CurPPLexer) { // Not ending a macro, ignore it.
328  if (const IdentifierInfo *ControllingMacro =
329  CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
330  // Okay, this has a controlling macro, remember in HeaderFileInfo.
331  if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
332  HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
333  if (MacroInfo *MI =
334  getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro)))
335  MI->setUsedForHeaderGuard(true);
336  if (const IdentifierInfo *DefinedMacro =
337  CurPPLexer->MIOpt.GetDefinedMacro()) {
338  if (!isMacroDefined(ControllingMacro) &&
339  DefinedMacro != ControllingMacro &&
340  HeaderInfo.FirstTimeLexingFile(FE)) {
341 
342  // If the edit distance between the two macros is more than 50%,
343  // DefinedMacro may not be header guard, or can be header guard of
344  // another header file. Therefore, it maybe defining something
345  // completely different. This can be observed in the wild when
346  // handling feature macros or header guards in different files.
347 
348  const StringRef ControllingMacroName = ControllingMacro->getName();
349  const StringRef DefinedMacroName = DefinedMacro->getName();
350  const size_t MaxHalfLength = std::max(ControllingMacroName.size(),
351  DefinedMacroName.size()) / 2;
352  const unsigned ED = ControllingMacroName.edit_distance(
353  DefinedMacroName, true, MaxHalfLength);
354  if (ED <= MaxHalfLength) {
355  // Emit a warning for a bad header guard.
356  Diag(CurPPLexer->MIOpt.GetMacroLocation(),
357  diag::warn_header_guard)
358  << CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro;
359  Diag(CurPPLexer->MIOpt.GetDefinedLocation(),
360  diag::note_header_guard)
361  << CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro
362  << ControllingMacro
364  CurPPLexer->MIOpt.GetDefinedLocation(),
365  ControllingMacro->getName());
366  }
367  }
368  }
369  }
370  }
371  }
372 
373  // Complain about reaching a true EOF within arc_cf_code_audited.
374  // We don't want to complain about reaching the end of a macro
375  // instantiation or a _Pragma.
376  if (PragmaARCCFCodeAuditedLoc.isValid() &&
377  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
378  Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited);
379 
380  // Recover by leaving immediately.
381  PragmaARCCFCodeAuditedLoc = SourceLocation();
382  }
383 
384  // Complain about reaching a true EOF within assume_nonnull.
385  // We don't want to complain about reaching the end of a macro
386  // instantiation or a _Pragma.
387  if (PragmaAssumeNonNullLoc.isValid() &&
388  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
389  Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
390 
391  // Recover by leaving immediately.
392  PragmaAssumeNonNullLoc = SourceLocation();
393  }
394 
395  bool LeavingPCHThroughHeader = false;
396 
397  // If this is a #include'd file, pop it off the include stack and continue
398  // lexing the #includer file.
399  if (!IncludeMacroStack.empty()) {
400 
401  // If we lexed the code-completion file, act as if we reached EOF.
402  if (isCodeCompletionEnabled() && CurPPLexer &&
403  SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
404  CodeCompletionFileLoc) {
405  assert(CurLexer && "Got EOF but no current lexer set!");
406  Result.startToken();
407  CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
408  CurLexer.reset();
409 
410  CurPPLexer = nullptr;
411  recomputeCurLexerKind();
412  return true;
413  }
414 
415  if (!isEndOfMacro && CurPPLexer &&
416  SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
417  // Notify SourceManager to record the number of FileIDs that were created
418  // during lexing of the #include'd file.
419  unsigned NumFIDs =
420  SourceMgr.local_sloc_entry_size() -
421  CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
422  SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
423  }
424 
425  bool ExitedFromPredefinesFile = false;
426  FileID ExitedFID;
427  if (!isEndOfMacro && CurPPLexer) {
428  ExitedFID = CurPPLexer->getFileID();
429 
430  assert(PredefinesFileID.isValid() &&
431  "HandleEndOfFile is called before PredefinesFileId is set");
432  ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
433  }
434 
435  if (LeavingSubmodule) {
436  // We're done with this submodule.
437  Module *M = LeaveSubmodule(/*ForPragma*/false);
438 
439  // Notify the parser that we've left the module.
440  const char *EndPos = getCurLexerEndPos();
441  Result.startToken();
442  CurLexer->BufferPtr = EndPos;
443  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
444  Result.setAnnotationEndLoc(Result.getLocation());
445  Result.setAnnotationValue(M);
446  }
447 
448  bool FoundPCHThroughHeader = false;
449  if (CurPPLexer && creatingPCHWithThroughHeader() &&
450  isPCHThroughHeader(
451  SourceMgr.getFileEntryForID(CurPPLexer->getFileID())))
452  FoundPCHThroughHeader = true;
453 
454  // We're done with the #included file.
455  RemoveTopOfLexerStack();
456 
457  // Propagate info about start-of-line/leading white-space/etc.
458  PropagateLineStartLeadingSpaceInfo(Result);
459 
460  // Notify the client, if desired, that we are in a new source file.
461  if (Callbacks && !isEndOfMacro && CurPPLexer) {
462  SrcMgr::CharacteristicKind FileType =
463  SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
464  Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
465  PPCallbacks::ExitFile, FileType, ExitedFID);
466  }
467 
468  // Restore conditional stack from the preamble right after exiting from the
469  // predefines file.
470  if (ExitedFromPredefinesFile)
471  replayPreambleConditionalStack();
472 
473  if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader &&
474  (isInPrimaryFile() ||
475  CurPPLexer->getFileID() == getPredefinesFileID())) {
476  // Leaving the through header. Continue directly to end of main file
477  // processing.
478  LeavingPCHThroughHeader = true;
479  } else {
480  // Client should lex another token unless we generated an EOM.
481  return LeavingSubmodule;
482  }
483  }
484 
485  // If this is the end of the main file, form an EOF token.
486  assert(CurLexer && "Got EOF but no current lexer set!");
487  const char *EndPos = getCurLexerEndPos();
488  Result.startToken();
489  CurLexer->BufferPtr = EndPos;
490  CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
491 
492  if (isCodeCompletionEnabled()) {
493  // Inserting the code-completion point increases the source buffer by 1,
494  // but the main FileID was created before inserting the point.
495  // Compensate by reducing the EOF location by 1, otherwise the location
496  // will point to the next FileID.
497  // FIXME: This is hacky, the code-completion point should probably be
498  // inserted before the main FileID is created.
499  if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
500  Result.setLocation(Result.getLocation().getLocWithOffset(-1));
501  }
502 
503  if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) {
504  // Reached the end of the compilation without finding the through header.
505  Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen)
506  << PPOpts->PCHThroughHeader << 0;
507  }
508 
509  if (!isIncrementalProcessingEnabled())
510  // We're done with lexing.
511  CurLexer.reset();
512 
513  if (!isIncrementalProcessingEnabled())
514  CurPPLexer = nullptr;
515 
516  if (TUKind == TU_Complete) {
517  // This is the end of the top-level file. 'WarnUnusedMacroLocs' has
518  // collected all macro locations that we need to warn because they are not
519  // used.
520  for (WarnUnusedMacroLocsTy::iterator
521  I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
522  I!=E; ++I)
523  Diag(*I, diag::pp_macro_not_used);
524  }
525 
526  // If we are building a module that has an umbrella header, make sure that
527  // each of the headers within the directory, including all submodules, is
528  // covered by the umbrella header was actually included by the umbrella
529  // header.
530  if (Module *Mod = getCurrentModule()) {
533  for (auto *M : AllMods)
534  diagnoseMissingHeaderInUmbrellaDir(*M);
535  }
536 
537  return true;
538 }
539 
540 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
541 /// hits the end of its token stream.
543  assert(CurTokenLexer && !CurPPLexer &&
544  "Ending a macro when currently in a #include file!");
545 
546  if (!MacroExpandingLexersStack.empty() &&
547  MacroExpandingLexersStack.back().first == CurTokenLexer.get())
548  removeCachedMacroExpandedTokensOfLastLexer();
549 
550  // Delete or cache the now-dead macro expander.
551  if (NumCachedTokenLexers == TokenLexerCacheSize)
552  CurTokenLexer.reset();
553  else
554  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
555 
556  // Handle this like a #include file being popped off the stack.
557  return HandleEndOfFile(Result, true);
558 }
559 
560 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
561 /// lexer stack. This should only be used in situations where the current
562 /// state of the top-of-stack lexer is unknown.
564  assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
565 
566  if (CurTokenLexer) {
567  // Delete or cache the now-dead macro expander.
568  if (NumCachedTokenLexers == TokenLexerCacheSize)
569  CurTokenLexer.reset();
570  else
571  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
572  }
573 
574  PopIncludeMacroStack();
575 }
576 
577 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a
578 /// comment (/##/) in microsoft mode, this method handles updating the current
579 /// state, returning the token on the next source line.
581  assert(CurTokenLexer && !CurPPLexer &&
582  "Pasted comment can only be formed from macro");
583  // We handle this by scanning for the closest real lexer, switching it to
584  // raw mode and preprocessor mode. This will cause it to return \n as an
585  // explicit EOD token.
586  PreprocessorLexer *FoundLexer = nullptr;
587  bool LexerWasInPPMode = false;
588  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
589  if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
590 
591  // Once we find a real lexer, mark it as raw mode (disabling macro
592  // expansions) and preprocessor mode (return EOD). We know that the lexer
593  // was *not* in raw mode before, because the macro that the comment came
594  // from was expanded. However, it could have already been in preprocessor
595  // mode (#if COMMENT) in which case we have to return it to that mode and
596  // return EOD.
597  FoundLexer = ISI.ThePPLexer;
598  FoundLexer->LexingRawMode = true;
599  LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
600  FoundLexer->ParsingPreprocessorDirective = true;
601  break;
602  }
603 
604  // Okay, we either found and switched over the lexer, or we didn't find a
605  // lexer. In either case, finish off the macro the comment came from, getting
606  // the next token.
607  if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
608 
609  // Discarding comments as long as we don't have EOF or EOD. This 'comments
610  // out' the rest of the line, including any tokens that came from other macros
611  // that were active, as in:
612  // #define submacro a COMMENT b
613  // submacro c
614  // which should lex to 'a' only: 'b' and 'c' should be removed.
615  while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
616  Lex(Tok);
617 
618  // If we got an eod token, then we successfully found the end of the line.
619  if (Tok.is(tok::eod)) {
620  assert(FoundLexer && "Can't get end of line without an active lexer");
621  // Restore the lexer back to normal mode instead of raw mode.
622  FoundLexer->LexingRawMode = false;
623 
624  // If the lexer was already in preprocessor mode, just return the EOD token
625  // to finish the preprocessor line.
626  if (LexerWasInPPMode) return;
627 
628  // Otherwise, switch out of PP mode and return the next lexed token.
629  FoundLexer->ParsingPreprocessorDirective = false;
630  return Lex(Tok);
631  }
632 
633  // If we got an EOF token, then we reached the end of the token stream but
634  // didn't find an explicit \n. This can only happen if there was no lexer
635  // active (an active lexer would return EOD at EOF if there was no \n in
636  // preprocessor directive mode), so just return EOF as our token.
637  assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
638 }
639 
641  bool ForPragma) {
642  if (!getLangOpts().ModulesLocalVisibility) {
643  // Just track that we entered this submodule.
644  BuildingSubmoduleStack.push_back(
645  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
646  PendingModuleMacroNames.size()));
647  return;
648  }
649 
650  // Resolve as much of the module definition as we can now, before we enter
651  // one of its headers.
652  // FIXME: Can we enable Complain here?
653  // FIXME: Can we do this when local visibility is disabled?
654  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
655  ModMap.resolveExports(M, /*Complain=*/false);
656  ModMap.resolveUses(M, /*Complain=*/false);
657  ModMap.resolveConflicts(M, /*Complain=*/false);
658 
659  // If this is the first time we've entered this module, set up its state.
660  auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
661  auto &State = R.first->second;
662  bool FirstTime = R.second;
663  if (FirstTime) {
664  // Determine the set of starting macros for this submodule; take these
665  // from the "null" module (the predefines buffer).
666  //
667  // FIXME: If we have local visibility but not modules enabled, the
668  // NullSubmoduleState is polluted by #defines in the top-level source
669  // file.
670  auto &StartingMacros = NullSubmoduleState.Macros;
671 
672  // Restore to the starting state.
673  // FIXME: Do this lazily, when each macro name is first referenced.
674  for (auto &Macro : StartingMacros) {
675  // Skip uninteresting macros.
676  if (!Macro.second.getLatest() &&
677  Macro.second.getOverriddenMacros().empty())
678  continue;
679 
680  MacroState MS(Macro.second.getLatest());
681  MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
682  State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
683  }
684  }
685 
686  // Track that we entered this module.
687  BuildingSubmoduleStack.push_back(
688  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
689  PendingModuleMacroNames.size()));
690 
691  // Switch to this submodule as the current submodule.
692  CurSubmoduleState = &State;
693 
694  // This module is visible to itself.
695  if (FirstTime)
696  makeModuleVisible(M, ImportLoc);
697 }
698 
699 bool Preprocessor::needModuleMacros() const {
700  // If we're not within a submodule, we never need to create ModuleMacros.
701  if (BuildingSubmoduleStack.empty())
702  return false;
703  // If we are tracking module macro visibility even for textually-included
704  // headers, we need ModuleMacros.
705  if (getLangOpts().ModulesLocalVisibility)
706  return true;
707  // Otherwise, we only need module macros if we're actually compiling a module
708  // interface.
709  return getLangOpts().isCompilingModule();
710 }
711 
713  if (BuildingSubmoduleStack.empty() ||
714  BuildingSubmoduleStack.back().IsPragma != ForPragma) {
715  assert(ForPragma && "non-pragma module enter/leave mismatch");
716  return nullptr;
717  }
718 
719  auto &Info = BuildingSubmoduleStack.back();
720 
721  Module *LeavingMod = Info.M;
722  SourceLocation ImportLoc = Info.ImportLoc;
723 
724  if (!needModuleMacros() ||
725  (!getLangOpts().ModulesLocalVisibility &&
726  LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
727  // If we don't need module macros, or this is not a module for which we
728  // are tracking macro visibility, don't build any, and preserve the list
729  // of pending names for the surrounding submodule.
730  BuildingSubmoduleStack.pop_back();
731  makeModuleVisible(LeavingMod, ImportLoc);
732  return LeavingMod;
733  }
734 
735  // Create ModuleMacros for any macros defined in this submodule.
736  llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
737  for (unsigned I = Info.OuterPendingModuleMacroNames;
738  I != PendingModuleMacroNames.size(); ++I) {
739  auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
740  if (!VisitedMacros.insert(II).second)
741  continue;
742 
743  auto MacroIt = CurSubmoduleState->Macros.find(II);
744  if (MacroIt == CurSubmoduleState->Macros.end())
745  continue;
746  auto &Macro = MacroIt->second;
747 
748  // Find the starting point for the MacroDirective chain in this submodule.
749  MacroDirective *OldMD = nullptr;
750  auto *OldState = Info.OuterSubmoduleState;
751  if (getLangOpts().ModulesLocalVisibility)
752  OldState = &NullSubmoduleState;
753  if (OldState && OldState != CurSubmoduleState) {
754  // FIXME: It'd be better to start at the state from when we most recently
755  // entered this submodule, but it doesn't really matter.
756  auto &OldMacros = OldState->Macros;
757  auto OldMacroIt = OldMacros.find(II);
758  if (OldMacroIt == OldMacros.end())
759  OldMD = nullptr;
760  else
761  OldMD = OldMacroIt->second.getLatest();
762  }
763 
764  // This module may have exported a new macro. If so, create a ModuleMacro
765  // representing that fact.
766  bool ExplicitlyPublic = false;
767  for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
768  assert(MD && "broken macro directive chain");
769 
770  if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
771  // The latest visibility directive for a name in a submodule affects
772  // all the directives that come before it.
773  if (VisMD->isPublic())
774  ExplicitlyPublic = true;
775  else if (!ExplicitlyPublic)
776  // Private with no following public directive: not exported.
777  break;
778  } else {
779  MacroInfo *Def = nullptr;
780  if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
781  Def = DefMD->getInfo();
782 
783  // FIXME: Issue a warning if multiple headers for the same submodule
784  // define a macro, rather than silently ignoring all but the first.
785  bool IsNew;
786  // Don't bother creating a module macro if it would represent a #undef
787  // that doesn't override anything.
788  if (Def || !Macro.getOverriddenMacros().empty())
789  addModuleMacro(LeavingMod, II, Def,
790  Macro.getOverriddenMacros(), IsNew);
791 
792  if (!getLangOpts().ModulesLocalVisibility) {
793  // This macro is exposed to the rest of this compilation as a
794  // ModuleMacro; we don't need to track its MacroDirective any more.
795  Macro.setLatest(nullptr);
796  Macro.setOverriddenMacros(*this, {});
797  }
798  break;
799  }
800  }
801  }
802  PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
803 
804  // FIXME: Before we leave this submodule, we should parse all the other
805  // headers within it. Otherwise, we're left with an inconsistent state
806  // where we've made the module visible but don't yet have its complete
807  // contents.
808 
809  // Put back the outer module's state, if we're tracking it.
810  if (getLangOpts().ModulesLocalVisibility)
811  CurSubmoduleState = Info.OuterSubmoduleState;
812 
813  BuildingSubmoduleStack.pop_back();
814 
815  // A nested #include makes the included submodule visible.
816  makeModuleVisible(LeavingMod, ImportLoc);
817  return LeavingMod;
818 }
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:76
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:116
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:94
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:1271
CharacteristicKind
Indicates whether a file or directory holds normal user code, system code, or system code which is im...
Definition: SourceManager.h:77
const MacroDirective * getPrevious() const
Get previous definition of the macro with the same name.
Definition: MacroInfo.h:328
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:406
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:1284
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:489
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
Describes a module or submodule.
Definition: Module.h:64
StringRef getTopLevelModuleName() const
Retrieve the name of the top-level module.
Definition: Module.h:467
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:213
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:168
void setAnnotationValue(void *val)
Definition: Token.h:227
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:29
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:123
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:1258
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:92
Encapsulates changes to the "macros namespace" (the location where the macro name became active...
Definition: MacroInfo.h:290
Encodes a location in the source.
StringRef getName() const
Definition: FileManager.h:83
void setAnnotationEndLoc(SourceLocation L)
Definition: Token.h:141
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:59
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:95
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:567
Encapsulates the data about a macro definition (e.g.
Definition: MacroInfo.h:39
DirectoryName getUmbrellaDir() const
Retrieve the directory for which this module serves as the umbrella.
Definition: Module.cpp:238
Cached information about one directory (either on disk or in the virtual file system).
Definition: FileManager.h:45
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:128
The translation unit is a complete translation unit.
Definition: LangOptions.h:363
bool isHeaderInUnavailableModule(const FileEntry *Header) const
Determine whether the given header is part of a module marked &#39;unavailable&#39;.
Definition: ModuleMap.cpp:667
__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:131
PreprocessorLexer * getCurrentFileLexer() const
Return the current file lexer being lexed from.
void startToken()
Reset all flags to cleared.
Definition: Token.h:168
StringRef getName() const
Definition: FileManager.h:51