1 //===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements pieces of the Preprocessor interface that manage the
11 // current lexer stack.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Lex/Preprocessor.h"
16 #include "clang/Basic/FileManager.h"
17 #include "clang/Basic/SourceManager.h"
18 #include "clang/Lex/HeaderSearch.h"
19 #include "clang/Lex/LexDiagnostic.h"
20 #include "clang/Lex/MacroInfo.h"
21 #include "clang/Lex/PTHManager.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;
28 PPCallbacks::~PPCallbacks() {}
30 //===----------------------------------------------------------------------===//
31 // Miscellaneous Methods.
32 //===----------------------------------------------------------------------===//
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.
36 bool Preprocessor::isInPrimaryFile() const {
38 return IncludeMacroStack.empty();
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 for (unsigned i = 1, e = IncludeMacroStack.size(); i != e; ++i)
44 if (IsFileLexer(IncludeMacroStack[i]))
49 /// getCurrentLexer - Return the current file lexer being lexed from. Note
50 /// that this ignores any potentially active macro expansions and _Pragma
51 /// expansions going on at the time.
52 PreprocessorLexer *Preprocessor::getCurrentFileLexer() const {
56 // Look for a stacked lexer.
57 for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
58 const IncludeStackInfo& ISI = IncludeMacroStack[i-1];
60 return ISI.ThePPLexer;
66 //===----------------------------------------------------------------------===//
67 // Methods for Entering and Callbacks for leaving various contexts
68 //===----------------------------------------------------------------------===//
70 /// EnterSourceFile - Add a source file to the top of the include stack and
71 /// start lexing tokens from it instead of the current buffer.
72 bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir,
74 assert(!CurTokenLexer && "Cannot #include a file inside a macro!");
75 ++NumEnteredSourceFiles;
77 if (MaxIncludeStackDepth < IncludeMacroStack.size())
78 MaxIncludeStackDepth = IncludeMacroStack.size();
81 if (PTHLexer *PL = PTH->CreateLexer(FID)) {
82 EnterSourceFileWithPTH(PL, CurDir);
87 // Get the MemoryBuffer for this FID, if it fails, we fail.
89 const llvm::MemoryBuffer *InputFile =
90 getSourceManager().getBuffer(FID, Loc, &Invalid);
92 SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID);
93 Diag(Loc, diag::err_pp_error_opening_file)
94 << std::string(SourceMgr.getBufferName(FileStart)) << "";
98 if (isCodeCompletionEnabled() &&
99 SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) {
100 CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID);
102 CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset);
105 EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
109 /// EnterSourceFileWithLexer - Add a source file to the top of the include stack
110 /// and start lexing tokens from it instead of the current buffer.
111 void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
112 const DirectoryLookup *CurDir) {
114 // Add the current lexer to the include stack.
115 if (CurPPLexer || CurTokenLexer)
116 PushIncludeMacroStack();
118 CurLexer.reset(TheLexer);
119 CurPPLexer = TheLexer;
120 CurDirLookup = CurDir;
121 CurSubmodule = nullptr;
122 if (CurLexerKind != CLK_LexAfterModuleImport)
123 CurLexerKind = CLK_Lexer;
125 // Notify the client, if desired, that we are in a new source file.
126 if (Callbacks && !CurLexer->Is_PragmaLexer) {
127 SrcMgr::CharacteristicKind FileType =
128 SourceMgr.getFileCharacteristic(CurLexer->getFileLoc());
130 Callbacks->FileChanged(CurLexer->getFileLoc(),
131 PPCallbacks::EnterFile, FileType);
135 /// EnterSourceFileWithPTH - Add a source file to the top of the include stack
136 /// and start getting tokens from it using the PTH cache.
137 void Preprocessor::EnterSourceFileWithPTH(PTHLexer *PL,
138 const DirectoryLookup *CurDir) {
140 if (CurPPLexer || CurTokenLexer)
141 PushIncludeMacroStack();
143 CurDirLookup = CurDir;
144 CurPTHLexer.reset(PL);
145 CurPPLexer = CurPTHLexer.get();
146 CurSubmodule = nullptr;
147 if (CurLexerKind != CLK_LexAfterModuleImport)
148 CurLexerKind = CLK_PTHLexer;
150 // Notify the client, if desired, that we are in a new source file.
152 FileID FID = CurPPLexer->getFileID();
153 SourceLocation EnterLoc = SourceMgr.getLocForStartOfFile(FID);
154 SrcMgr::CharacteristicKind FileType =
155 SourceMgr.getFileCharacteristic(EnterLoc);
156 Callbacks->FileChanged(EnterLoc, PPCallbacks::EnterFile, FileType);
160 /// EnterMacro - Add a Macro to the top of the include stack and start lexing
161 /// tokens from it instead of the current buffer.
162 void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
163 MacroInfo *Macro, MacroArgs *Args) {
164 std::unique_ptr<TokenLexer> TokLexer;
165 if (NumCachedTokenLexers == 0) {
166 TokLexer = llvm::make_unique<TokenLexer>(Tok, ILEnd, Macro, Args, *this);
168 TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
169 TokLexer->Init(Tok, ILEnd, Macro, Args);
172 PushIncludeMacroStack();
173 CurDirLookup = nullptr;
174 CurTokenLexer = std::move(TokLexer);
175 if (CurLexerKind != CLK_LexAfterModuleImport)
176 CurLexerKind = CLK_TokenLexer;
179 /// EnterTokenStream - Add a "macro" context to the top of the include stack,
180 /// which will cause the lexer to start returning the specified tokens.
182 /// If DisableMacroExpansion is true, tokens lexed from the token stream will
183 /// not be subject to further macro expansion. Otherwise, these tokens will
184 /// be re-macro-expanded when/if expansion is enabled.
186 /// If OwnsTokens is false, this method assumes that the specified stream of
187 /// tokens has a permanent owner somewhere, so they do not need to be copied.
188 /// If it is true, it assumes the array of tokens is allocated with new[] and
191 void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
192 bool DisableMacroExpansion,
194 if (CurLexerKind == CLK_CachingLexer) {
195 if (CachedLexPos < CachedTokens.size()) {
196 // We're entering tokens into the middle of our cached token stream. We
197 // can't represent that, so just insert the tokens into the buffer.
198 CachedTokens.insert(CachedTokens.begin() + CachedLexPos,
199 Toks, Toks + NumToks);
205 // New tokens are at the end of the cached token sequnece; insert the
206 // token stream underneath the caching lexer.
207 ExitCachingLexMode();
208 EnterTokenStream(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
209 EnterCachingLexMode();
213 // Create a macro expander to expand from the specified token stream.
214 std::unique_ptr<TokenLexer> TokLexer;
215 if (NumCachedTokenLexers == 0) {
216 TokLexer = llvm::make_unique<TokenLexer>(
217 Toks, NumToks, DisableMacroExpansion, OwnsTokens, *this);
219 TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
220 TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
223 // Save our current state.
224 PushIncludeMacroStack();
225 CurDirLookup = nullptr;
226 CurTokenLexer = std::move(TokLexer);
227 if (CurLexerKind != CLK_LexAfterModuleImport)
228 CurLexerKind = CLK_TokenLexer;
231 /// \brief Compute the relative path that names the given file relative to
232 /// the given directory.
233 static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
234 const FileEntry *File,
235 SmallString<128> &Result) {
238 StringRef FilePath = File->getDir()->getName();
239 StringRef Path = FilePath;
240 while (!Path.empty()) {
241 if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) {
243 Result = FilePath.substr(Path.size());
244 llvm::sys::path::append(Result,
245 llvm::sys::path::filename(File->getName()));
250 Path = llvm::sys::path::parent_path(Path);
253 Result = File->getName();
256 void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
258 CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
262 CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
265 // FIXME: Handle other kinds of lexers? It generally shouldn't matter,
266 // but it might if they're empty?
269 /// \brief Determine the location to use as the end of the buffer for a lexer.
271 /// If the file ends with a newline, form the EOF token on the newline itself,
272 /// rather than "on the line following it", which doesn't exist. This makes
273 /// diagnostics relating to the end of file include the last file that the user
274 /// actually typed, which is goodness.
275 const char *Preprocessor::getCurLexerEndPos() {
276 const char *EndPos = CurLexer->BufferEnd;
277 if (EndPos != CurLexer->BufferStart &&
278 (EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
281 // Handle \n\r and \r\n:
282 if (EndPos != CurLexer->BufferStart &&
283 (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
284 EndPos[-1] != EndPos[0])
292 /// HandleEndOfFile - This callback is invoked when the lexer hits the end of
293 /// the current file. This either returns the EOF token or pops a level off
294 /// the include stack and keeps going.
295 bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
296 assert(!CurTokenLexer &&
297 "Ending a file when currently in a macro!");
299 // See if this file had a controlling macro.
300 if (CurPPLexer) { // Not ending a macro, ignore it.
301 if (const IdentifierInfo *ControllingMacro =
302 CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
303 // Okay, this has a controlling macro, remember in HeaderFileInfo.
304 if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
305 HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
307 getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro))) {
308 MI->UsedForHeaderGuard = true;
310 if (const IdentifierInfo *DefinedMacro =
311 CurPPLexer->MIOpt.GetDefinedMacro()) {
312 if (!isMacroDefined(ControllingMacro) &&
313 DefinedMacro != ControllingMacro &&
314 HeaderInfo.FirstTimeLexingFile(FE)) {
316 // If the edit distance between the two macros is more than 50%,
317 // DefinedMacro may not be header guard, or can be header guard of
318 // another header file. Therefore, it maybe defining something
319 // completely different. This can be observed in the wild when
320 // handling feature macros or header guards in different files.
322 const StringRef ControllingMacroName = ControllingMacro->getName();
323 const StringRef DefinedMacroName = DefinedMacro->getName();
324 const size_t MaxHalfLength = std::max(ControllingMacroName.size(),
325 DefinedMacroName.size()) / 2;
326 const unsigned ED = ControllingMacroName.edit_distance(
327 DefinedMacroName, true, MaxHalfLength);
328 if (ED <= MaxHalfLength) {
329 // Emit a warning for a bad header guard.
330 Diag(CurPPLexer->MIOpt.GetMacroLocation(),
331 diag::warn_header_guard)
332 << CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro;
333 Diag(CurPPLexer->MIOpt.GetDefinedLocation(),
334 diag::note_header_guard)
335 << CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro
337 << FixItHint::CreateReplacement(
338 CurPPLexer->MIOpt.GetDefinedLocation(),
339 ControllingMacro->getName());
347 // Complain about reaching a true EOF within arc_cf_code_audited.
348 // We don't want to complain about reaching the end of a macro
349 // instantiation or a _Pragma.
350 if (PragmaARCCFCodeAuditedLoc.isValid() &&
351 !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
352 Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited);
354 // Recover by leaving immediately.
355 PragmaARCCFCodeAuditedLoc = SourceLocation();
358 // Complain about reaching a true EOF within assume_nonnull.
359 // We don't want to complain about reaching the end of a macro
360 // instantiation or a _Pragma.
361 if (PragmaAssumeNonNullLoc.isValid() &&
362 !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
363 Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
365 // Recover by leaving immediately.
366 PragmaAssumeNonNullLoc = SourceLocation();
369 // If this is a #include'd file, pop it off the include stack and continue
370 // lexing the #includer file.
371 if (!IncludeMacroStack.empty()) {
373 // If we lexed the code-completion file, act as if we reached EOF.
374 if (isCodeCompletionEnabled() && CurPPLexer &&
375 SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
376 CodeCompletionFileLoc) {
379 CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
382 assert(CurPTHLexer && "Got EOF but no current lexer set!");
383 CurPTHLexer->getEOF(Result);
387 CurPPLexer = nullptr;
391 if (!isEndOfMacro && CurPPLexer &&
392 SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
393 // Notify SourceManager to record the number of FileIDs that were created
394 // during lexing of the #include'd file.
396 SourceMgr.local_sloc_entry_size() -
397 CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
398 SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
402 if (Callbacks && !isEndOfMacro && CurPPLexer)
403 ExitedFID = CurPPLexer->getFileID();
405 bool LeavingSubmodule = CurSubmodule && CurLexer;
406 if (LeavingSubmodule) {
407 // Notify the parser that we've left the module.
408 const char *EndPos = getCurLexerEndPos();
410 CurLexer->BufferPtr = EndPos;
411 CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
412 Result.setAnnotationEndLoc(Result.getLocation());
413 Result.setAnnotationValue(CurSubmodule);
415 // We're done with this submodule.
419 // We're done with the #included file.
420 RemoveTopOfLexerStack();
422 // Propagate info about start-of-line/leading white-space/etc.
423 PropagateLineStartLeadingSpaceInfo(Result);
425 // Notify the client, if desired, that we are in a new source file.
426 if (Callbacks && !isEndOfMacro && CurPPLexer) {
427 SrcMgr::CharacteristicKind FileType =
428 SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
429 Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
430 PPCallbacks::ExitFile, FileType, ExitedFID);
433 // Client should lex another token unless we generated an EOM.
434 return LeavingSubmodule;
437 // If this is the end of the main file, form an EOF token.
439 const char *EndPos = getCurLexerEndPos();
441 CurLexer->BufferPtr = EndPos;
442 CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
444 if (isCodeCompletionEnabled()) {
445 // Inserting the code-completion point increases the source buffer by 1,
446 // but the main FileID was created before inserting the point.
447 // Compensate by reducing the EOF location by 1, otherwise the location
448 // will point to the next FileID.
449 // FIXME: This is hacky, the code-completion point should probably be
450 // inserted before the main FileID is created.
451 if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
452 Result.setLocation(Result.getLocation().getLocWithOffset(-1));
455 if (!isIncrementalProcessingEnabled())
456 // We're done with lexing.
459 assert(CurPTHLexer && "Got EOF but no current lexer set!");
460 CurPTHLexer->getEOF(Result);
464 if (!isIncrementalProcessingEnabled())
465 CurPPLexer = nullptr;
467 if (TUKind == TU_Complete) {
468 // This is the end of the top-level file. 'WarnUnusedMacroLocs' has
469 // collected all macro locations that we need to warn because they are not
471 for (WarnUnusedMacroLocsTy::iterator
472 I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
474 Diag(*I, diag::pp_macro_not_used);
477 // If we are building a module that has an umbrella header, make sure that
478 // each of the headers within the directory covered by the umbrella header
479 // was actually included by the umbrella header.
480 if (Module *Mod = getCurrentModule()) {
481 if (Mod->getUmbrellaHeader()) {
482 SourceLocation StartLoc
483 = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
485 if (!getDiagnostics().isIgnored(diag::warn_uncovered_module_header,
487 ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
488 const DirectoryEntry *Dir = Mod->getUmbrellaDir().Entry;
489 vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
491 for (vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC), End;
492 Entry != End && !EC; Entry.increment(EC)) {
493 using llvm::StringSwitch;
495 // Check whether this entry has an extension typically associated with
497 if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->getName()))
498 .Cases(".h", ".H", ".hh", ".hpp", true)
502 if (const FileEntry *Header =
503 getFileManager().getFile(Entry->getName()))
504 if (!getSourceManager().hasFileInfo(Header)) {
505 if (!ModMap.isHeaderInUnavailableModule(Header)) {
506 // Find the relative path that would access this header.
507 SmallString<128> RelativePath;
508 computeRelativePath(FileMgr, Dir, Header, RelativePath);
509 Diag(StartLoc, diag::warn_uncovered_module_header)
510 << Mod->getFullModuleName() << RelativePath;
521 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
522 /// hits the end of its token stream.
523 bool Preprocessor::HandleEndOfTokenLexer(Token &Result) {
524 assert(CurTokenLexer && !CurPPLexer &&
525 "Ending a macro when currently in a #include file!");
527 if (!MacroExpandingLexersStack.empty() &&
528 MacroExpandingLexersStack.back().first == CurTokenLexer.get())
529 removeCachedMacroExpandedTokensOfLastLexer();
531 // Delete or cache the now-dead macro expander.
532 if (NumCachedTokenLexers == TokenLexerCacheSize)
533 CurTokenLexer.reset();
535 TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
537 // Handle this like a #include file being popped off the stack.
538 return HandleEndOfFile(Result, true);
541 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
542 /// lexer stack. This should only be used in situations where the current
543 /// state of the top-of-stack lexer is unknown.
544 void Preprocessor::RemoveTopOfLexerStack() {
545 assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
548 // Delete or cache the now-dead macro expander.
549 if (NumCachedTokenLexers == TokenLexerCacheSize)
550 CurTokenLexer.reset();
552 TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
555 PopIncludeMacroStack();
558 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a
559 /// comment (/##/) in microsoft mode, this method handles updating the current
560 /// state, returning the token on the next source line.
561 void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
562 assert(CurTokenLexer && !CurPPLexer &&
563 "Pasted comment can only be formed from macro");
564 // We handle this by scanning for the closest real lexer, switching it to
565 // raw mode and preprocessor mode. This will cause it to return \n as an
566 // explicit EOD token.
567 PreprocessorLexer *FoundLexer = nullptr;
568 bool LexerWasInPPMode = false;
569 for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
570 IncludeStackInfo &ISI = *(IncludeMacroStack.end()-i-1);
571 if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
573 // Once we find a real lexer, mark it as raw mode (disabling macro
574 // expansions) and preprocessor mode (return EOD). We know that the lexer
575 // was *not* in raw mode before, because the macro that the comment came
576 // from was expanded. However, it could have already been in preprocessor
577 // mode (#if COMMENT) in which case we have to return it to that mode and
579 FoundLexer = ISI.ThePPLexer;
580 FoundLexer->LexingRawMode = true;
581 LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
582 FoundLexer->ParsingPreprocessorDirective = true;
586 // Okay, we either found and switched over the lexer, or we didn't find a
587 // lexer. In either case, finish off the macro the comment came from, getting
589 if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
591 // Discarding comments as long as we don't have EOF or EOD. This 'comments
592 // out' the rest of the line, including any tokens that came from other macros
593 // that were active, as in:
594 // #define submacro a COMMENT b
596 // which should lex to 'a' only: 'b' and 'c' should be removed.
597 while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
600 // If we got an eod token, then we successfully found the end of the line.
601 if (Tok.is(tok::eod)) {
602 assert(FoundLexer && "Can't get end of line without an active lexer");
603 // Restore the lexer back to normal mode instead of raw mode.
604 FoundLexer->LexingRawMode = false;
606 // If the lexer was already in preprocessor mode, just return the EOD token
607 // to finish the preprocessor line.
608 if (LexerWasInPPMode) return;
610 // Otherwise, switch out of PP mode and return the next lexed token.
611 FoundLexer->ParsingPreprocessorDirective = false;
615 // If we got an EOF token, then we reached the end of the token stream but
616 // didn't find an explicit \n. This can only happen if there was no lexer
617 // active (an active lexer would return EOD at EOF if there was no \n in
618 // preprocessor directive mode), so just return EOF as our token.
619 assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
622 void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc) {
623 if (!getLangOpts().ModulesLocalVisibility) {
624 // Just track that we entered this submodule.
625 BuildingSubmoduleStack.push_back(BuildingSubmoduleInfo(
626 M, ImportLoc, CurSubmoduleState, PendingModuleMacroNames.size()));
630 // Resolve as much of the module definition as we can now, before we enter
631 // one of its headers.
632 // FIXME: Can we enable Complain here?
633 // FIXME: Can we do this when local visibility is disabled?
634 ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
635 ModMap.resolveExports(M, /*Complain=*/false);
636 ModMap.resolveUses(M, /*Complain=*/false);
637 ModMap.resolveConflicts(M, /*Complain=*/false);
639 // If this is the first time we've entered this module, set up its state.
640 auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
641 auto &State = R.first->second;
642 bool FirstTime = R.second;
644 // Determine the set of starting macros for this submodule; take these
645 // from the "null" module (the predefines buffer).
647 // FIXME: If we have local visibility but not modules enabled, the
648 // NullSubmoduleState is polluted by #defines in the top-level source
650 auto &StartingMacros = NullSubmoduleState.Macros;
652 // Restore to the starting state.
653 // FIXME: Do this lazily, when each macro name is first referenced.
654 for (auto &Macro : StartingMacros) {
655 // Skip uninteresting macros.
656 if (!Macro.second.getLatest() &&
657 Macro.second.getOverriddenMacros().empty())
660 MacroState MS(Macro.second.getLatest());
661 MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
662 State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
666 // Track that we entered this module.
667 BuildingSubmoduleStack.push_back(BuildingSubmoduleInfo(
668 M, ImportLoc, CurSubmoduleState, PendingModuleMacroNames.size()));
670 // Switch to this submodule as the current submodule.
671 CurSubmoduleState = &State;
673 // This module is visible to itself.
675 makeModuleVisible(M, ImportLoc);
678 bool Preprocessor::needModuleMacros() const {
679 // If we're not within a submodule, we never need to create ModuleMacros.
680 if (BuildingSubmoduleStack.empty())
682 // If we are tracking module macro visibility even for textually-included
683 // headers, we need ModuleMacros.
684 if (getLangOpts().ModulesLocalVisibility)
686 // Otherwise, we only need module macros if we're actually compiling a module
688 return getLangOpts().CompilingModule;
691 void Preprocessor::LeaveSubmodule() {
692 auto &Info = BuildingSubmoduleStack.back();
694 Module *LeavingMod = Info.M;
695 SourceLocation ImportLoc = Info.ImportLoc;
697 if (!needModuleMacros() ||
698 (!getLangOpts().ModulesLocalVisibility &&
699 LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
700 // If we don't need module macros, or this is not a module for which we
701 // are tracking macro visibility, don't build any, and preserve the list
702 // of pending names for the surrounding submodule.
703 BuildingSubmoduleStack.pop_back();
704 makeModuleVisible(LeavingMod, ImportLoc);
708 // Create ModuleMacros for any macros defined in this submodule.
709 llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
710 for (unsigned I = Info.OuterPendingModuleMacroNames;
711 I != PendingModuleMacroNames.size(); ++I) {
712 auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
713 if (!VisitedMacros.insert(II).second)
716 auto MacroIt = CurSubmoduleState->Macros.find(II);
717 if (MacroIt == CurSubmoduleState->Macros.end())
719 auto &Macro = MacroIt->second;
721 // Find the starting point for the MacroDirective chain in this submodule.
722 MacroDirective *OldMD = nullptr;
723 auto *OldState = Info.OuterSubmoduleState;
724 if (getLangOpts().ModulesLocalVisibility)
725 OldState = &NullSubmoduleState;
726 if (OldState && OldState != CurSubmoduleState) {
727 // FIXME: It'd be better to start at the state from when we most recently
728 // entered this submodule, but it doesn't really matter.
729 auto &OldMacros = OldState->Macros;
730 auto OldMacroIt = OldMacros.find(II);
731 if (OldMacroIt == OldMacros.end())
734 OldMD = OldMacroIt->second.getLatest();
737 // This module may have exported a new macro. If so, create a ModuleMacro
738 // representing that fact.
739 bool ExplicitlyPublic = false;
740 for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
741 assert(MD && "broken macro directive chain");
743 // Stop on macros defined in other submodules of this module that we
744 // #included along the way. There's no point doing this if we're
745 // tracking local submodule visibility, since there can be no such
746 // directives in our list.
747 if (!getLangOpts().ModulesLocalVisibility) {
748 Module *Mod = getModuleContainingLocation(MD->getLocation());
749 if (Mod != LeavingMod &&
750 Mod->getTopLevelModule() == LeavingMod->getTopLevelModule())
754 if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
755 // The latest visibility directive for a name in a submodule affects
756 // all the directives that come before it.
757 if (VisMD->isPublic())
758 ExplicitlyPublic = true;
759 else if (!ExplicitlyPublic)
760 // Private with no following public directive: not exported.
763 MacroInfo *Def = nullptr;
764 if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
765 Def = DefMD->getInfo();
767 // FIXME: Issue a warning if multiple headers for the same submodule
768 // define a macro, rather than silently ignoring all but the first.
770 // Don't bother creating a module macro if it would represent a #undef
771 // that doesn't override anything.
772 if (Def || !Macro.getOverriddenMacros().empty())
773 addModuleMacro(LeavingMod, II, Def,
774 Macro.getOverriddenMacros(), IsNew);
779 PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
781 // FIXME: Before we leave this submodule, we should parse all the other
782 // headers within it. Otherwise, we're left with an inconsistent state
783 // where we've made the module visible but don't yet have its complete
786 // Put back the outer module's state, if we're tracking it.
787 if (getLangOpts().ModulesLocalVisibility)
788 CurSubmoduleState = Info.OuterSubmoduleState;
790 BuildingSubmoduleStack.pop_back();
792 // A nested #include makes the included submodule visible.
793 makeModuleVisible(LeavingMod, ImportLoc);