1 //===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements pieces of the Preprocessor interface that manage the
10 // current lexer stack.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Lex/Preprocessor.h"
15 #include "clang/Lex/PreprocessorOptions.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 "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;
27 PPCallbacks::~PPCallbacks() {}
29 //===----------------------------------------------------------------------===//
30 // Miscellaneous Methods.
31 //===----------------------------------------------------------------------===//
33 /// isInPrimaryFile - Return true if we're in the top-level file, not in a
34 /// \#include. This looks through macro expansions and active _Pragma lexers.
35 bool Preprocessor::isInPrimaryFile() const {
37 return IncludeMacroStack.empty();
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?");
43 IncludeMacroStack.begin() + 1, IncludeMacroStack.end(),
44 [&](const IncludeStackInfo &ISI) -> bool { return IsFileLexer(ISI); });
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.
50 PreprocessorLexer *Preprocessor::getCurrentFileLexer() const {
54 // Look for a stacked lexer.
55 for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
57 return ISI.ThePPLexer;
63 //===----------------------------------------------------------------------===//
64 // Methods for Entering and Callbacks for leaving various contexts
65 //===----------------------------------------------------------------------===//
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.
69 bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir,
71 assert(!CurTokenLexer && "Cannot #include a file inside a macro!");
72 ++NumEnteredSourceFiles;
74 if (MaxIncludeStackDepth < IncludeMacroStack.size())
75 MaxIncludeStackDepth = IncludeMacroStack.size();
77 // Get the MemoryBuffer for this FID, if it fails, we fail.
79 const llvm::MemoryBuffer *InputFile =
80 getSourceManager().getBuffer(FID, Loc, &Invalid);
82 SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID);
83 Diag(Loc, diag::err_pp_error_opening_file)
84 << std::string(SourceMgr.getBufferName(FileStart)) << "";
88 if (isCodeCompletionEnabled() &&
89 SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) {
90 CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID);
92 CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset);
95 EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
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) {
104 // Add the current lexer to the include stack.
105 if (CurPPLexer || CurTokenLexer)
106 PushIncludeMacroStack();
108 CurLexer.reset(TheLexer);
109 CurPPLexer = TheLexer;
110 CurDirLookup = CurDir;
111 CurLexerSubmodule = nullptr;
112 if (CurLexerKind != CLK_LexAfterModuleImport)
113 CurLexerKind = CLK_Lexer;
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());
120 Callbacks->FileChanged(CurLexer->getFileLoc(),
121 PPCallbacks::EnterFile, FileType);
125 /// EnterMacro - Add a Macro to the top of the include stack and start lexing
126 /// tokens from it instead of the current buffer.
127 void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
128 MacroInfo *Macro, MacroArgs *Args) {
129 std::unique_ptr<TokenLexer> TokLexer;
130 if (NumCachedTokenLexers == 0) {
131 TokLexer = std::make_unique<TokenLexer>(Tok, ILEnd, Macro, Args, *this);
133 TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
134 TokLexer->Init(Tok, ILEnd, Macro, Args);
137 PushIncludeMacroStack();
138 CurDirLookup = nullptr;
139 CurTokenLexer = std::move(TokLexer);
140 if (CurLexerKind != CLK_LexAfterModuleImport)
141 CurLexerKind = CLK_TokenLexer;
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.
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.
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
156 void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
157 bool DisableMacroExpansion, bool OwnsTokens,
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);
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,
176 EnterCachingLexMode();
180 // Create a macro expander to expand from the specified token stream.
181 std::unique_ptr<TokenLexer> TokLexer;
182 if (NumCachedTokenLexers == 0) {
183 TokLexer = std::make_unique<TokenLexer>(
184 Toks, NumToks, DisableMacroExpansion, OwnsTokens, IsReinject, *this);
186 TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
187 TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens,
191 // Save our current state.
192 PushIncludeMacroStack();
193 CurDirLookup = nullptr;
194 CurTokenLexer = std::move(TokLexer);
195 if (CurLexerKind != CLK_LexAfterModuleImport)
196 CurLexerKind = CLK_TokenLexer;
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,
203 SmallString<128> &Result) {
206 StringRef FilePath = File->getDir()->getName();
207 StringRef Path = FilePath;
208 while (!Path.empty()) {
209 if (auto 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()));
218 Path = llvm::sys::path::parent_path(Path);
221 Result = File->getName();
224 void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
226 CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
230 CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
233 // FIXME: Handle other kinds of lexers? It generally shouldn't matter,
234 // but it might if they're empty?
237 /// Determine the location to use as the end of the buffer for a lexer.
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')) {
249 // Handle \n\r and \r\n:
250 if (EndPos != CurLexer->BufferStart &&
251 (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
252 EndPos[-1] != EndPos[0])
259 static void collectAllSubModulesWithUmbrellaHeader(
260 const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
261 if (Mod.getUmbrellaHeader())
262 SubMods.push_back(&Mod);
263 for (auto *M : Mod.submodules())
264 collectAllSubModulesWithUmbrellaHeader(*M, SubMods);
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))
274 ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
275 const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
276 llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
278 for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
280 Entry != End && !EC; Entry.increment(EC)) {
281 using llvm::StringSwitch;
283 // Check whether this entry has an extension typically associated with
285 if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path()))
286 .Cases(".h", ".H", ".hh", ".hpp", true)
290 if (auto 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;
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!");
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);
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);
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);
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)) {
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.
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
366 << FixItHint::CreateReplacement(
367 CurPPLexer->MIOpt.GetDefinedLocation(),
368 ControllingMacro->getName());
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 (PragmaARCCFCodeAuditedInfo.second.isValid() && !isEndOfMacro &&
380 !(CurLexer && CurLexer->Is_PragmaLexer)) {
381 Diag(PragmaARCCFCodeAuditedInfo.second,
382 diag::err_pp_eof_in_arc_cf_code_audited);
384 // Recover by leaving immediately.
385 PragmaARCCFCodeAuditedInfo = {nullptr, SourceLocation()};
388 // Complain about reaching a true EOF within assume_nonnull.
389 // We don't want to complain about reaching the end of a macro
390 // instantiation or a _Pragma.
391 if (PragmaAssumeNonNullLoc.isValid() &&
392 !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
393 Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
395 // Recover by leaving immediately.
396 PragmaAssumeNonNullLoc = SourceLocation();
399 bool LeavingPCHThroughHeader = false;
401 // If this is a #include'd file, pop it off the include stack and continue
402 // lexing the #includer file.
403 if (!IncludeMacroStack.empty()) {
405 // If we lexed the code-completion file, act as if we reached EOF.
406 if (isCodeCompletionEnabled() && CurPPLexer &&
407 SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
408 CodeCompletionFileLoc) {
409 assert(CurLexer && "Got EOF but no current lexer set!");
411 CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
414 CurPPLexer = nullptr;
415 recomputeCurLexerKind();
419 if (!isEndOfMacro && CurPPLexer &&
420 SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
421 // Notify SourceManager to record the number of FileIDs that were created
422 // during lexing of the #include'd file.
424 SourceMgr.local_sloc_entry_size() -
425 CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
426 SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
429 bool ExitedFromPredefinesFile = false;
431 if (!isEndOfMacro && CurPPLexer) {
432 ExitedFID = CurPPLexer->getFileID();
434 assert(PredefinesFileID.isValid() &&
435 "HandleEndOfFile is called before PredefinesFileId is set");
436 ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
439 if (LeavingSubmodule) {
440 // We're done with this submodule.
441 Module *M = LeaveSubmodule(/*ForPragma*/false);
443 // Notify the parser that we've left the module.
444 const char *EndPos = getCurLexerEndPos();
446 CurLexer->BufferPtr = EndPos;
447 CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
448 Result.setAnnotationEndLoc(Result.getLocation());
449 Result.setAnnotationValue(M);
452 bool FoundPCHThroughHeader = false;
453 if (CurPPLexer && creatingPCHWithThroughHeader() &&
455 SourceMgr.getFileEntryForID(CurPPLexer->getFileID())))
456 FoundPCHThroughHeader = true;
458 // We're done with the #included file.
459 RemoveTopOfLexerStack();
461 // Propagate info about start-of-line/leading white-space/etc.
462 PropagateLineStartLeadingSpaceInfo(Result);
464 // Notify the client, if desired, that we are in a new source file.
465 if (Callbacks && !isEndOfMacro && CurPPLexer) {
466 SrcMgr::CharacteristicKind FileType =
467 SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
468 Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
469 PPCallbacks::ExitFile, FileType, ExitedFID);
472 // Restore conditional stack from the preamble right after exiting from the
474 if (ExitedFromPredefinesFile)
475 replayPreambleConditionalStack();
477 if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader &&
478 (isInPrimaryFile() ||
479 CurPPLexer->getFileID() == getPredefinesFileID())) {
480 // Leaving the through header. Continue directly to end of main file
482 LeavingPCHThroughHeader = true;
484 // Client should lex another token unless we generated an EOM.
485 return LeavingSubmodule;
489 // If this is the end of the main file, form an EOF token.
490 assert(CurLexer && "Got EOF but no current lexer set!");
491 const char *EndPos = getCurLexerEndPos();
493 CurLexer->BufferPtr = EndPos;
494 CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
496 if (isCodeCompletionEnabled()) {
497 // Inserting the code-completion point increases the source buffer by 1,
498 // but the main FileID was created before inserting the point.
499 // Compensate by reducing the EOF location by 1, otherwise the location
500 // will point to the next FileID.
501 // FIXME: This is hacky, the code-completion point should probably be
502 // inserted before the main FileID is created.
503 if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
504 Result.setLocation(Result.getLocation().getLocWithOffset(-1));
507 if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) {
508 // Reached the end of the compilation without finding the through header.
509 Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen)
510 << PPOpts->PCHThroughHeader << 0;
513 if (!isIncrementalProcessingEnabled())
514 // We're done with lexing.
517 if (!isIncrementalProcessingEnabled())
518 CurPPLexer = nullptr;
520 if (TUKind == TU_Complete) {
521 // This is the end of the top-level file. 'WarnUnusedMacroLocs' has
522 // collected all macro locations that we need to warn because they are not
524 for (WarnUnusedMacroLocsTy::iterator
525 I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
527 Diag(*I, diag::pp_macro_not_used);
530 // If we are building a module that has an umbrella header, make sure that
531 // each of the headers within the directory, including all submodules, is
532 // covered by the umbrella header was actually included by the umbrella
534 if (Module *Mod = getCurrentModule()) {
535 llvm::SmallVector<const Module *, 4> AllMods;
536 collectAllSubModulesWithUmbrellaHeader(*Mod, AllMods);
537 for (auto *M : AllMods)
538 diagnoseMissingHeaderInUmbrellaDir(*M);
544 /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
545 /// hits the end of its token stream.
546 bool Preprocessor::HandleEndOfTokenLexer(Token &Result) {
547 assert(CurTokenLexer && !CurPPLexer &&
548 "Ending a macro when currently in a #include file!");
550 if (!MacroExpandingLexersStack.empty() &&
551 MacroExpandingLexersStack.back().first == CurTokenLexer.get())
552 removeCachedMacroExpandedTokensOfLastLexer();
554 // Delete or cache the now-dead macro expander.
555 if (NumCachedTokenLexers == TokenLexerCacheSize)
556 CurTokenLexer.reset();
558 TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
560 // Handle this like a #include file being popped off the stack.
561 return HandleEndOfFile(Result, true);
564 /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
565 /// lexer stack. This should only be used in situations where the current
566 /// state of the top-of-stack lexer is unknown.
567 void Preprocessor::RemoveTopOfLexerStack() {
568 assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
571 // Delete or cache the now-dead macro expander.
572 if (NumCachedTokenLexers == TokenLexerCacheSize)
573 CurTokenLexer.reset();
575 TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
578 PopIncludeMacroStack();
581 /// HandleMicrosoftCommentPaste - When the macro expander pastes together a
582 /// comment (/##/) in microsoft mode, this method handles updating the current
583 /// state, returning the token on the next source line.
584 void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
585 assert(CurTokenLexer && !CurPPLexer &&
586 "Pasted comment can only be formed from macro");
587 // We handle this by scanning for the closest real lexer, switching it to
588 // raw mode and preprocessor mode. This will cause it to return \n as an
589 // explicit EOD token.
590 PreprocessorLexer *FoundLexer = nullptr;
591 bool LexerWasInPPMode = false;
592 for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
593 if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
595 // Once we find a real lexer, mark it as raw mode (disabling macro
596 // expansions) and preprocessor mode (return EOD). We know that the lexer
597 // was *not* in raw mode before, because the macro that the comment came
598 // from was expanded. However, it could have already been in preprocessor
599 // mode (#if COMMENT) in which case we have to return it to that mode and
601 FoundLexer = ISI.ThePPLexer;
602 FoundLexer->LexingRawMode = true;
603 LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
604 FoundLexer->ParsingPreprocessorDirective = true;
608 // Okay, we either found and switched over the lexer, or we didn't find a
609 // lexer. In either case, finish off the macro the comment came from, getting
611 if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
613 // Discarding comments as long as we don't have EOF or EOD. This 'comments
614 // out' the rest of the line, including any tokens that came from other macros
615 // that were active, as in:
616 // #define submacro a COMMENT b
618 // which should lex to 'a' only: 'b' and 'c' should be removed.
619 while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
622 // If we got an eod token, then we successfully found the end of the line.
623 if (Tok.is(tok::eod)) {
624 assert(FoundLexer && "Can't get end of line without an active lexer");
625 // Restore the lexer back to normal mode instead of raw mode.
626 FoundLexer->LexingRawMode = false;
628 // If the lexer was already in preprocessor mode, just return the EOD token
629 // to finish the preprocessor line.
630 if (LexerWasInPPMode) return;
632 // Otherwise, switch out of PP mode and return the next lexed token.
633 FoundLexer->ParsingPreprocessorDirective = false;
637 // If we got an EOF token, then we reached the end of the token stream but
638 // didn't find an explicit \n. This can only happen if there was no lexer
639 // active (an active lexer would return EOD at EOF if there was no \n in
640 // preprocessor directive mode), so just return EOF as our token.
641 assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
644 void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc,
646 if (!getLangOpts().ModulesLocalVisibility) {
647 // Just track that we entered this submodule.
648 BuildingSubmoduleStack.push_back(
649 BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
650 PendingModuleMacroNames.size()));
652 Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma);
656 // Resolve as much of the module definition as we can now, before we enter
657 // one of its headers.
658 // FIXME: Can we enable Complain here?
659 // FIXME: Can we do this when local visibility is disabled?
660 ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
661 ModMap.resolveExports(M, /*Complain=*/false);
662 ModMap.resolveUses(M, /*Complain=*/false);
663 ModMap.resolveConflicts(M, /*Complain=*/false);
665 // If this is the first time we've entered this module, set up its state.
666 auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
667 auto &State = R.first->second;
668 bool FirstTime = R.second;
670 // Determine the set of starting macros for this submodule; take these
671 // from the "null" module (the predefines buffer).
673 // FIXME: If we have local visibility but not modules enabled, the
674 // NullSubmoduleState is polluted by #defines in the top-level source
676 auto &StartingMacros = NullSubmoduleState.Macros;
678 // Restore to the starting state.
679 // FIXME: Do this lazily, when each macro name is first referenced.
680 for (auto &Macro : StartingMacros) {
681 // Skip uninteresting macros.
682 if (!Macro.second.getLatest() &&
683 Macro.second.getOverriddenMacros().empty())
686 MacroState MS(Macro.second.getLatest());
687 MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
688 State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
692 // Track that we entered this module.
693 BuildingSubmoduleStack.push_back(
694 BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
695 PendingModuleMacroNames.size()));
698 Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma);
700 // Switch to this submodule as the current submodule.
701 CurSubmoduleState = &State;
703 // This module is visible to itself.
705 makeModuleVisible(M, ImportLoc);
708 bool Preprocessor::needModuleMacros() const {
709 // If we're not within a submodule, we never need to create ModuleMacros.
710 if (BuildingSubmoduleStack.empty())
712 // If we are tracking module macro visibility even for textually-included
713 // headers, we need ModuleMacros.
714 if (getLangOpts().ModulesLocalVisibility)
716 // Otherwise, we only need module macros if we're actually compiling a module
718 return getLangOpts().isCompilingModule();
721 Module *Preprocessor::LeaveSubmodule(bool ForPragma) {
722 if (BuildingSubmoduleStack.empty() ||
723 BuildingSubmoduleStack.back().IsPragma != ForPragma) {
724 assert(ForPragma && "non-pragma module enter/leave mismatch");
728 auto &Info = BuildingSubmoduleStack.back();
730 Module *LeavingMod = Info.M;
731 SourceLocation ImportLoc = Info.ImportLoc;
733 if (!needModuleMacros() ||
734 (!getLangOpts().ModulesLocalVisibility &&
735 LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
736 // If we don't need module macros, or this is not a module for which we
737 // are tracking macro visibility, don't build any, and preserve the list
738 // of pending names for the surrounding submodule.
739 BuildingSubmoduleStack.pop_back();
742 Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma);
744 makeModuleVisible(LeavingMod, ImportLoc);
748 // Create ModuleMacros for any macros defined in this submodule.
749 llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
750 for (unsigned I = Info.OuterPendingModuleMacroNames;
751 I != PendingModuleMacroNames.size(); ++I) {
752 auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
753 if (!VisitedMacros.insert(II).second)
756 auto MacroIt = CurSubmoduleState->Macros.find(II);
757 if (MacroIt == CurSubmoduleState->Macros.end())
759 auto &Macro = MacroIt->second;
761 // Find the starting point for the MacroDirective chain in this submodule.
762 MacroDirective *OldMD = nullptr;
763 auto *OldState = Info.OuterSubmoduleState;
764 if (getLangOpts().ModulesLocalVisibility)
765 OldState = &NullSubmoduleState;
766 if (OldState && OldState != CurSubmoduleState) {
767 // FIXME: It'd be better to start at the state from when we most recently
768 // entered this submodule, but it doesn't really matter.
769 auto &OldMacros = OldState->Macros;
770 auto OldMacroIt = OldMacros.find(II);
771 if (OldMacroIt == OldMacros.end())
774 OldMD = OldMacroIt->second.getLatest();
777 // This module may have exported a new macro. If so, create a ModuleMacro
778 // representing that fact.
779 bool ExplicitlyPublic = false;
780 for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
781 assert(MD && "broken macro directive chain");
783 if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
784 // The latest visibility directive for a name in a submodule affects
785 // all the directives that come before it.
786 if (VisMD->isPublic())
787 ExplicitlyPublic = true;
788 else if (!ExplicitlyPublic)
789 // Private with no following public directive: not exported.
792 MacroInfo *Def = nullptr;
793 if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
794 Def = DefMD->getInfo();
796 // FIXME: Issue a warning if multiple headers for the same submodule
797 // define a macro, rather than silently ignoring all but the first.
799 // Don't bother creating a module macro if it would represent a #undef
800 // that doesn't override anything.
801 if (Def || !Macro.getOverriddenMacros().empty())
802 addModuleMacro(LeavingMod, II, Def,
803 Macro.getOverriddenMacros(), IsNew);
805 if (!getLangOpts().ModulesLocalVisibility) {
806 // This macro is exposed to the rest of this compilation as a
807 // ModuleMacro; we don't need to track its MacroDirective any more.
808 Macro.setLatest(nullptr);
809 Macro.setOverriddenMacros(*this, {});
815 PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
817 // FIXME: Before we leave this submodule, we should parse all the other
818 // headers within it. Otherwise, we're left with an inconsistent state
819 // where we've made the module visible but don't yet have its complete
822 // Put back the outer module's state, if we're tracking it.
823 if (getLangOpts().ModulesLocalVisibility)
824 CurSubmoduleState = Info.OuterSubmoduleState;
826 BuildingSubmoduleStack.pop_back();
829 Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma);
831 // A nested #include makes the included submodule visible.
832 makeModuleVisible(LeavingMod, ImportLoc);