clang  9.0.0svn
PPLexerChange.cpp
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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, bool OwnsTokens,
158  bool IsReinject) {
159  if (CurLexerKind == CLK_CachingLexer) {
160  if (CachedLexPos < CachedTokens.size()) {
161  assert(IsReinject && "new tokens in the middle of cached stream");
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  IsReinject);
176  EnterCachingLexMode();
177  return;
178  }
179 
180  // Create a macro expander to expand from the specified token stream.
181  std::unique_ptr<TokenLexer> TokLexer;
182  if (NumCachedTokenLexers == 0) {
183  TokLexer = llvm::make_unique<TokenLexer>(
184  Toks, NumToks, DisableMacroExpansion, OwnsTokens, IsReinject, *this);
185  } else {
186  TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
187  TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens,
188  IsReinject);
189  }
190 
191  // Save our current state.
192  PushIncludeMacroStack();
193  CurDirLookup = nullptr;
194  CurTokenLexer = std::move(TokLexer);
195  if (CurLexerKind != CLK_LexAfterModuleImport)
196  CurLexerKind = CLK_TokenLexer;
197 }
198 
199 /// Compute the relative path that names the given file relative to
200 /// the given directory.
201 static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
202  const FileEntry *File,
204  Result.clear();
205 
206  StringRef FilePath = File->getDir()->getName();
207  StringRef Path = FilePath;
208  while (!Path.empty()) {
209  if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) {
210  if (CurDir == Dir) {
211  Result = FilePath.substr(Path.size());
212  llvm::sys::path::append(Result,
213  llvm::sys::path::filename(File->getName()));
214  return;
215  }
216  }
217 
218  Path = llvm::sys::path::parent_path(Path);
219  }
220 
221  Result = File->getName();
222 }
223 
224 void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
225  if (CurTokenLexer) {
226  CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
227  return;
228  }
229  if (CurLexer) {
230  CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
231  return;
232  }
233  // FIXME: Handle other kinds of lexers? It generally shouldn't matter,
234  // but it might if they're empty?
235 }
236 
237 /// Determine the location to use as the end of the buffer for a lexer.
238 ///
239 /// If the file ends with a newline, form the EOF token on the newline itself,
240 /// rather than "on the line following it", which doesn't exist. This makes
241 /// diagnostics relating to the end of file include the last file that the user
242 /// actually typed, which is goodness.
243 const char *Preprocessor::getCurLexerEndPos() {
244  const char *EndPos = CurLexer->BufferEnd;
245  if (EndPos != CurLexer->BufferStart &&
246  (EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
247  --EndPos;
248 
249  // Handle \n\r and \r\n:
250  if (EndPos != CurLexer->BufferStart &&
251  (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
252  EndPos[-1] != EndPos[0])
253  --EndPos;
254  }
255 
256  return EndPos;
257 }
258 
260  const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
261  if (Mod.getUmbrellaHeader())
262  SubMods.push_back(&Mod);
263  for (auto *M : Mod.submodules())
265 }
266 
267 void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
268  assert(Mod.getUmbrellaHeader() && "Module must use umbrella header");
269  SourceLocation StartLoc =
270  SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
271  if (getDiagnostics().isIgnored(diag::warn_uncovered_module_header, StartLoc))
272  return;
273 
274  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
275  const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
276  llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
277  std::error_code EC;
278  for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
279  End;
280  Entry != End && !EC; Entry.increment(EC)) {
281  using llvm::StringSwitch;
282 
283  // Check whether this entry has an extension typically associated with
284  // headers.
285  if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path()))
286  .Cases(".h", ".H", ".hh", ".hpp", true)
287  .Default(false))
288  continue;
289 
290  if (const FileEntry *Header = getFileManager().getFile(Entry->path()))
291  if (!getSourceManager().hasFileInfo(Header)) {
292  if (!ModMap.isHeaderInUnavailableModule(Header)) {
293  // Find the relative path that would access this header.
294  SmallString<128> RelativePath;
295  computeRelativePath(FileMgr, Dir, Header, RelativePath);
296  Diag(StartLoc, diag::warn_uncovered_module_header)
297  << Mod.getFullModuleName() << RelativePath;
298  }
299  }
300  }
301 }
302 
303 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of
304 /// the current file. This either returns the EOF token or pops a level off
305 /// the include stack and keeps going.
306 bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
307  assert(!CurTokenLexer &&
308  "Ending a file when currently in a macro!");
309 
310  // If we have an unclosed module region from a pragma at the end of a
311  // module, complain and close it now.
312  const bool LeavingSubmodule = CurLexer && CurLexerSubmodule;
313  if ((LeavingSubmodule || IncludeMacroStack.empty()) &&
314  !BuildingSubmoduleStack.empty() &&
315  BuildingSubmoduleStack.back().IsPragma) {
316  Diag(BuildingSubmoduleStack.back().ImportLoc,
317  diag::err_pp_module_begin_without_module_end);
318  Module *M = LeaveSubmodule(/*ForPragma*/true);
319 
320  Result.startToken();
321  const char *EndPos = getCurLexerEndPos();
322  CurLexer->BufferPtr = EndPos;
323  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
324  Result.setAnnotationEndLoc(Result.getLocation());
325  Result.setAnnotationValue(M);
326  return true;
327  }
328 
329  // See if this file had a controlling macro.
330  if (CurPPLexer) { // Not ending a macro, ignore it.
331  if (const IdentifierInfo *ControllingMacro =
332  CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
333  // Okay, this has a controlling macro, remember in HeaderFileInfo.
334  if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
335  HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
336  if (MacroInfo *MI =
337  getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro)))
338  MI->setUsedForHeaderGuard(true);
339  if (const IdentifierInfo *DefinedMacro =
340  CurPPLexer->MIOpt.GetDefinedMacro()) {
341  if (!isMacroDefined(ControllingMacro) &&
342  DefinedMacro != ControllingMacro &&
343  HeaderInfo.FirstTimeLexingFile(FE)) {
344 
345  // If the edit distance between the two macros is more than 50%,
346  // DefinedMacro may not be header guard, or can be header guard of
347  // another header file. Therefore, it maybe defining something
348  // completely different. This can be observed in the wild when
349  // handling feature macros or header guards in different files.
350 
351  const StringRef ControllingMacroName = ControllingMacro->getName();
352  const StringRef DefinedMacroName = DefinedMacro->getName();
353  const size_t MaxHalfLength = std::max(ControllingMacroName.size(),
354  DefinedMacroName.size()) / 2;
355  const unsigned ED = ControllingMacroName.edit_distance(
356  DefinedMacroName, true, MaxHalfLength);
357  if (ED <= MaxHalfLength) {
358  // Emit a warning for a bad header guard.
359  Diag(CurPPLexer->MIOpt.GetMacroLocation(),
360  diag::warn_header_guard)
361  << CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro;
362  Diag(CurPPLexer->MIOpt.GetDefinedLocation(),
363  diag::note_header_guard)
364  << CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro
365  << ControllingMacro
367  CurPPLexer->MIOpt.GetDefinedLocation(),
368  ControllingMacro->getName());
369  }
370  }
371  }
372  }
373  }
374  }
375 
376  // Complain about reaching a true EOF within arc_cf_code_audited.
377  // We don't want to complain about reaching the end of a macro
378  // instantiation or a _Pragma.
379  if (PragmaARCCFCodeAuditedLoc.isValid() &&
380  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
381  Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited);
382 
383  // Recover by leaving immediately.
384  PragmaARCCFCodeAuditedLoc = SourceLocation();
385  }
386 
387  // Complain about reaching a true EOF within assume_nonnull.
388  // We don't want to complain about reaching the end of a macro
389  // instantiation or a _Pragma.
390  if (PragmaAssumeNonNullLoc.isValid() &&
391  !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
392  Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
393 
394  // Recover by leaving immediately.
395  PragmaAssumeNonNullLoc = SourceLocation();
396  }
397 
398  bool LeavingPCHThroughHeader = false;
399 
400  // If this is a #include'd file, pop it off the include stack and continue
401  // lexing the #includer file.
402  if (!IncludeMacroStack.empty()) {
403 
404  // If we lexed the code-completion file, act as if we reached EOF.
405  if (isCodeCompletionEnabled() && CurPPLexer &&
406  SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
407  CodeCompletionFileLoc) {
408  assert(CurLexer && "Got EOF but no current lexer set!");
409  Result.startToken();
410  CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
411  CurLexer.reset();
412 
413  CurPPLexer = nullptr;
414  recomputeCurLexerKind();
415  return true;
416  }
417 
418  if (!isEndOfMacro && CurPPLexer &&
419  SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
420  // Notify SourceManager to record the number of FileIDs that were created
421  // during lexing of the #include'd file.
422  unsigned NumFIDs =
423  SourceMgr.local_sloc_entry_size() -
424  CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
425  SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
426  }
427 
428  bool ExitedFromPredefinesFile = false;
429  FileID ExitedFID;
430  if (!isEndOfMacro && CurPPLexer) {
431  ExitedFID = CurPPLexer->getFileID();
432 
433  assert(PredefinesFileID.isValid() &&
434  "HandleEndOfFile is called before PredefinesFileId is set");
435  ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
436  }
437 
438  if (LeavingSubmodule) {
439  // We're done with this submodule.
440  Module *M = LeaveSubmodule(/*ForPragma*/false);
441 
442  // Notify the parser that we've left the module.
443  const char *EndPos = getCurLexerEndPos();
444  Result.startToken();
445  CurLexer->BufferPtr = EndPos;
446  CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
447  Result.setAnnotationEndLoc(Result.getLocation());
448  Result.setAnnotationValue(M);
449  }
450 
451  bool FoundPCHThroughHeader = false;
452  if (CurPPLexer && creatingPCHWithThroughHeader() &&
453  isPCHThroughHeader(
454  SourceMgr.getFileEntryForID(CurPPLexer->getFileID())))
455  FoundPCHThroughHeader = true;
456 
457  // We're done with the #included file.
458  RemoveTopOfLexerStack();
459 
460  // Propagate info about start-of-line/leading white-space/etc.
461  PropagateLineStartLeadingSpaceInfo(Result);
462 
463  // Notify the client, if desired, that we are in a new source file.
464  if (Callbacks && !isEndOfMacro && CurPPLexer) {
465  SrcMgr::CharacteristicKind FileType =
466  SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
467  Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
468  PPCallbacks::ExitFile, FileType, ExitedFID);
469  }
470 
471  // Restore conditional stack from the preamble right after exiting from the
472  // predefines file.
473  if (ExitedFromPredefinesFile)
474  replayPreambleConditionalStack();
475 
476  if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader &&
477  (isInPrimaryFile() ||
478  CurPPLexer->getFileID() == getPredefinesFileID())) {
479  // Leaving the through header. Continue directly to end of main file
480  // processing.
481  LeavingPCHThroughHeader = true;
482  } else {
483  // Client should lex another token unless we generated an EOM.
484  return LeavingSubmodule;
485  }
486  }
487 
488  // If this is the end of the main file, form an EOF token.
489  assert(CurLexer && "Got EOF but no current lexer set!");
490  const char *EndPos = getCurLexerEndPos();
491  Result.startToken();
492  CurLexer->BufferPtr = EndPos;
493  CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
494 
495  if (isCodeCompletionEnabled()) {
496  // Inserting the code-completion point increases the source buffer by 1,
497  // but the main FileID was created before inserting the point.
498  // Compensate by reducing the EOF location by 1, otherwise the location
499  // will point to the next FileID.
500  // FIXME: This is hacky, the code-completion point should probably be
501  // inserted before the main FileID is created.
502  if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
503  Result.setLocation(Result.getLocation().getLocWithOffset(-1));
504  }
505 
506  if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) {
507  // Reached the end of the compilation without finding the through header.
508  Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen)
509  << PPOpts->PCHThroughHeader << 0;
510  }
511 
512  if (!isIncrementalProcessingEnabled())
513  // We're done with lexing.
514  CurLexer.reset();
515 
516  if (!isIncrementalProcessingEnabled())
517  CurPPLexer = nullptr;
518 
519  if (TUKind == TU_Complete) {
520  // This is the end of the top-level file. 'WarnUnusedMacroLocs' has
521  // collected all macro locations that we need to warn because they are not
522  // used.
523  for (WarnUnusedMacroLocsTy::iterator
524  I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
525  I!=E; ++I)
526  Diag(*I, diag::pp_macro_not_used);
527  }
528 
529  // If we are building a module that has an umbrella header, make sure that
530  // each of the headers within the directory, including all submodules, is
531  // covered by the umbrella header was actually included by the umbrella
532  // header.
533  if (Module *Mod = getCurrentModule()) {
536  for (auto *M : AllMods)
537  diagnoseMissingHeaderInUmbrellaDir(*M);
538  }
539 
540  return true;
541 }
542 
543 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
544 /// hits the end of its token stream.
546  assert(CurTokenLexer && !CurPPLexer &&
547  "Ending a macro when currently in a #include file!");
548 
549  if (!MacroExpandingLexersStack.empty() &&
550  MacroExpandingLexersStack.back().first == CurTokenLexer.get())
551  removeCachedMacroExpandedTokensOfLastLexer();
552 
553  // Delete or cache the now-dead macro expander.
554  if (NumCachedTokenLexers == TokenLexerCacheSize)
555  CurTokenLexer.reset();
556  else
557  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
558 
559  // Handle this like a #include file being popped off the stack.
560  return HandleEndOfFile(Result, true);
561 }
562 
563 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
564 /// lexer stack. This should only be used in situations where the current
565 /// state of the top-of-stack lexer is unknown.
567  assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
568 
569  if (CurTokenLexer) {
570  // Delete or cache the now-dead macro expander.
571  if (NumCachedTokenLexers == TokenLexerCacheSize)
572  CurTokenLexer.reset();
573  else
574  TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
575  }
576 
577  PopIncludeMacroStack();
578 }
579 
580 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a
581 /// comment (/##/) in microsoft mode, this method handles updating the current
582 /// state, returning the token on the next source line.
584  assert(CurTokenLexer && !CurPPLexer &&
585  "Pasted comment can only be formed from macro");
586  // We handle this by scanning for the closest real lexer, switching it to
587  // raw mode and preprocessor mode. This will cause it to return \n as an
588  // explicit EOD token.
589  PreprocessorLexer *FoundLexer = nullptr;
590  bool LexerWasInPPMode = false;
591  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
592  if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
593 
594  // Once we find a real lexer, mark it as raw mode (disabling macro
595  // expansions) and preprocessor mode (return EOD). We know that the lexer
596  // was *not* in raw mode before, because the macro that the comment came
597  // from was expanded. However, it could have already been in preprocessor
598  // mode (#if COMMENT) in which case we have to return it to that mode and
599  // return EOD.
600  FoundLexer = ISI.ThePPLexer;
601  FoundLexer->LexingRawMode = true;
602  LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
603  FoundLexer->ParsingPreprocessorDirective = true;
604  break;
605  }
606 
607  // Okay, we either found and switched over the lexer, or we didn't find a
608  // lexer. In either case, finish off the macro the comment came from, getting
609  // the next token.
610  if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
611 
612  // Discarding comments as long as we don't have EOF or EOD. This 'comments
613  // out' the rest of the line, including any tokens that came from other macros
614  // that were active, as in:
615  // #define submacro a COMMENT b
616  // submacro c
617  // which should lex to 'a' only: 'b' and 'c' should be removed.
618  while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
619  Lex(Tok);
620 
621  // If we got an eod token, then we successfully found the end of the line.
622  if (Tok.is(tok::eod)) {
623  assert(FoundLexer && "Can't get end of line without an active lexer");
624  // Restore the lexer back to normal mode instead of raw mode.
625  FoundLexer->LexingRawMode = false;
626 
627  // If the lexer was already in preprocessor mode, just return the EOD token
628  // to finish the preprocessor line.
629  if (LexerWasInPPMode) return;
630 
631  // Otherwise, switch out of PP mode and return the next lexed token.
632  FoundLexer->ParsingPreprocessorDirective = false;
633  return Lex(Tok);
634  }
635 
636  // If we got an EOF token, then we reached the end of the token stream but
637  // didn't find an explicit \n. This can only happen if there was no lexer
638  // active (an active lexer would return EOD at EOF if there was no \n in
639  // preprocessor directive mode), so just return EOF as our token.
640  assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
641 }
642 
644  bool ForPragma) {
645  if (!getLangOpts().ModulesLocalVisibility) {
646  // Just track that we entered this submodule.
647  BuildingSubmoduleStack.push_back(
648  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
649  PendingModuleMacroNames.size()));
650  if (Callbacks)
651  Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma);
652  return;
653  }
654 
655  // Resolve as much of the module definition as we can now, before we enter
656  // one of its headers.
657  // FIXME: Can we enable Complain here?
658  // FIXME: Can we do this when local visibility is disabled?
659  ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
660  ModMap.resolveExports(M, /*Complain=*/false);
661  ModMap.resolveUses(M, /*Complain=*/false);
662  ModMap.resolveConflicts(M, /*Complain=*/false);
663 
664  // If this is the first time we've entered this module, set up its state.
665  auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
666  auto &State = R.first->second;
667  bool FirstTime = R.second;
668  if (FirstTime) {
669  // Determine the set of starting macros for this submodule; take these
670  // from the "null" module (the predefines buffer).
671  //
672  // FIXME: If we have local visibility but not modules enabled, the
673  // NullSubmoduleState is polluted by #defines in the top-level source
674  // file.
675  auto &StartingMacros = NullSubmoduleState.Macros;
676 
677  // Restore to the starting state.
678  // FIXME: Do this lazily, when each macro name is first referenced.
679  for (auto &Macro : StartingMacros) {
680  // Skip uninteresting macros.
681  if (!Macro.second.getLatest() &&
682  Macro.second.getOverriddenMacros().empty())
683  continue;
684 
685  MacroState MS(Macro.second.getLatest());
686  MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
687  State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
688  }
689  }
690 
691  // Track that we entered this module.
692  BuildingSubmoduleStack.push_back(
693  BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
694  PendingModuleMacroNames.size()));
695 
696  if (Callbacks)
697  Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma);
698 
699  // Switch to this submodule as the current submodule.
700  CurSubmoduleState = &State;
701 
702  // This module is visible to itself.
703  if (FirstTime)
704  makeModuleVisible(M, ImportLoc);
705 }
706 
707 bool Preprocessor::needModuleMacros() const {
708  // If we're not within a submodule, we never need to create ModuleMacros.
709  if (BuildingSubmoduleStack.empty())
710  return false;
711  // If we are tracking module macro visibility even for textually-included
712  // headers, we need ModuleMacros.
713  if (getLangOpts().ModulesLocalVisibility)
714  return true;
715  // Otherwise, we only need module macros if we're actually compiling a module
716  // interface.
717  return getLangOpts().isCompilingModule();
718 }
719 
721  if (BuildingSubmoduleStack.empty() ||
722  BuildingSubmoduleStack.back().IsPragma != ForPragma) {
723  assert(ForPragma && "non-pragma module enter/leave mismatch");
724  return nullptr;
725  }
726 
727  auto &Info = BuildingSubmoduleStack.back();
728 
729  Module *LeavingMod = Info.M;
730  SourceLocation ImportLoc = Info.ImportLoc;
731 
732  if (!needModuleMacros() ||
733  (!getLangOpts().ModulesLocalVisibility &&
734  LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
735  // If we don't need module macros, or this is not a module for which we
736  // are tracking macro visibility, don't build any, and preserve the list
737  // of pending names for the surrounding submodule.
738  BuildingSubmoduleStack.pop_back();
739 
740  if (Callbacks)
741  Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma);
742 
743  makeModuleVisible(LeavingMod, ImportLoc);
744  return LeavingMod;
745  }
746 
747  // Create ModuleMacros for any macros defined in this submodule.
748  llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
749  for (unsigned I = Info.OuterPendingModuleMacroNames;
750  I != PendingModuleMacroNames.size(); ++I) {
751  auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
752  if (!VisitedMacros.insert(II).second)
753  continue;
754 
755  auto MacroIt = CurSubmoduleState->Macros.find(II);
756  if (MacroIt == CurSubmoduleState->Macros.end())
757  continue;
758  auto &Macro = MacroIt->second;
759 
760  // Find the starting point for the MacroDirective chain in this submodule.
761  MacroDirective *OldMD = nullptr;
762  auto *OldState = Info.OuterSubmoduleState;
763  if (getLangOpts().ModulesLocalVisibility)
764  OldState = &NullSubmoduleState;
765  if (OldState && OldState != CurSubmoduleState) {
766  // FIXME: It'd be better to start at the state from when we most recently
767  // entered this submodule, but it doesn't really matter.
768  auto &OldMacros = OldState->Macros;
769  auto OldMacroIt = OldMacros.find(II);
770  if (OldMacroIt == OldMacros.end())
771  OldMD = nullptr;
772  else
773  OldMD = OldMacroIt->second.getLatest();
774  }
775 
776  // This module may have exported a new macro. If so, create a ModuleMacro
777  // representing that fact.
778  bool ExplicitlyPublic = false;
779  for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
780  assert(MD && "broken macro directive chain");
781 
782  if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
783  // The latest visibility directive for a name in a submodule affects
784  // all the directives that come before it.
785  if (VisMD->isPublic())
786  ExplicitlyPublic = true;
787  else if (!ExplicitlyPublic)
788  // Private with no following public directive: not exported.
789  break;
790  } else {
791  MacroInfo *Def = nullptr;
792  if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
793  Def = DefMD->getInfo();
794 
795  // FIXME: Issue a warning if multiple headers for the same submodule
796  // define a macro, rather than silently ignoring all but the first.
797  bool IsNew;
798  // Don't bother creating a module macro if it would represent a #undef
799  // that doesn't override anything.
800  if (Def || !Macro.getOverriddenMacros().empty())
801  addModuleMacro(LeavingMod, II, Def,
802  Macro.getOverriddenMacros(), IsNew);
803 
804  if (!getLangOpts().ModulesLocalVisibility) {
805  // This macro is exposed to the rest of this compilation as a
806  // ModuleMacro; we don't need to track its MacroDirective any more.
807  Macro.setLatest(nullptr);
808  Macro.setOverriddenMacros(*this, {});
809  }
810  break;
811  }
812  }
813  }
814  PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
815 
816  // FIXME: Before we leave this submodule, we should parse all the other
817  // headers within it. Otherwise, we're left with an inconsistent state
818  // where we've made the module visible but don't yet have its complete
819  // contents.
820 
821  // Put back the outer module's state, if we're tracking it.
822  if (getLangOpts().ModulesLocalVisibility)
823  CurSubmoduleState = Info.OuterSubmoduleState;
824 
825  BuildingSubmoduleStack.pop_back();
826 
827  if (Callbacks)
828  Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma);
829 
830  // A nested #include makes the included submodule visible.
831  makeModuleVisible(LeavingMod, ImportLoc);
832  return LeavingMod;
833 }
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:97
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
__DEVICE__ int max(int __a, int __b)
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:230
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:126
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:144
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:98
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:568
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:129
The translation unit is a complete translation unit.
Definition: LangOptions.h:364
bool isHeaderInUnavailableModule(const FileEntry *Header) const
Determine whether the given header is part of a module marked &#39;unavailable&#39;.
Definition: ModuleMap.cpp:667
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:134
PreprocessorLexer * getCurrentFileLexer() const
Return the current file lexer being lexed from.
void startToken()
Reset all flags to cleared.
Definition: Token.h:171
StringRef getName() const
Definition: FileManager.h:51