//===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file implements pieces of the Preprocessor interface that manage the // current lexer stack. // //===----------------------------------------------------------------------===// #include "clang/Lex/Preprocessor.h" #include "clang/Lex/PreprocessorOptions.h" #include "clang/Basic/FileManager.h" #include "clang/Basic/SourceManager.h" #include "clang/Lex/HeaderSearch.h" #include "clang/Lex/LexDiagnostic.h" #include "clang/Lex/MacroInfo.h" #include "llvm/ADT/StringSwitch.h" #include "llvm/Support/FileSystem.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/Support/Path.h" using namespace clang; //===----------------------------------------------------------------------===// // Miscellaneous Methods. //===----------------------------------------------------------------------===// /// isInPrimaryFile - Return true if we're in the top-level file, not in a /// \#include. This looks through macro expansions and active _Pragma lexers. bool Preprocessor::isInPrimaryFile() const { if (IsFileLexer()) return IncludeMacroStack.empty(); // If there are any stacked lexers, we're in a #include. assert(IsFileLexer(IncludeMacroStack[0]) && "Top level include stack isn't our primary lexer?"); return std::none_of( IncludeMacroStack.begin() + 1, IncludeMacroStack.end(), [&](const IncludeStackInfo &ISI) -> bool { return IsFileLexer(ISI); }); } /// getCurrentLexer - Return the current file lexer being lexed from. Note /// that this ignores any potentially active macro expansions and _Pragma /// expansions going on at the time. PreprocessorLexer *Preprocessor::getCurrentFileLexer() const { if (IsFileLexer()) return CurPPLexer; // Look for a stacked lexer. for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) { if (IsFileLexer(ISI)) return ISI.ThePPLexer; } return nullptr; } //===----------------------------------------------------------------------===// // Methods for Entering and Callbacks for leaving various contexts //===----------------------------------------------------------------------===// /// EnterSourceFile - Add a source file to the top of the include stack and /// start lexing tokens from it instead of the current buffer. bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir, SourceLocation Loc) { assert(!CurTokenLexer && "Cannot #include a file inside a macro!"); ++NumEnteredSourceFiles; if (MaxIncludeStackDepth < IncludeMacroStack.size()) MaxIncludeStackDepth = IncludeMacroStack.size(); // Get the MemoryBuffer for this FID, if it fails, we fail. bool Invalid = false; const llvm::MemoryBuffer *InputFile = getSourceManager().getBuffer(FID, Loc, &Invalid); if (Invalid) { SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID); Diag(Loc, diag::err_pp_error_opening_file) << std::string(SourceMgr.getBufferName(FileStart)) << ""; return true; } if (isCodeCompletionEnabled() && SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) { CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID); CodeCompletionLoc = CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset); } EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir); return false; } /// EnterSourceFileWithLexer - Add a source file to the top of the include stack /// and start lexing tokens from it instead of the current buffer. void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer, const DirectoryLookup *CurDir) { // Add the current lexer to the include stack. if (CurPPLexer || CurTokenLexer) PushIncludeMacroStack(); CurLexer.reset(TheLexer); CurPPLexer = TheLexer; CurDirLookup = CurDir; CurLexerSubmodule = nullptr; if (CurLexerKind != CLK_LexAfterModuleImport) CurLexerKind = CLK_Lexer; // Notify the client, if desired, that we are in a new source file. if (Callbacks && !CurLexer->Is_PragmaLexer) { SrcMgr::CharacteristicKind FileType = SourceMgr.getFileCharacteristic(CurLexer->getFileLoc()); Callbacks->FileChanged(CurLexer->getFileLoc(), PPCallbacks::EnterFile, FileType); } } /// EnterMacro - Add a Macro to the top of the include stack and start lexing /// tokens from it instead of the current buffer. void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd, MacroInfo *Macro, MacroArgs *Args) { std::unique_ptr TokLexer; if (NumCachedTokenLexers == 0) { TokLexer = std::make_unique(Tok, ILEnd, Macro, Args, *this); } else { TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]); TokLexer->Init(Tok, ILEnd, Macro, Args); } PushIncludeMacroStack(); CurDirLookup = nullptr; CurTokenLexer = std::move(TokLexer); if (CurLexerKind != CLK_LexAfterModuleImport) CurLexerKind = CLK_TokenLexer; } /// EnterTokenStream - Add a "macro" context to the top of the include stack, /// which will cause the lexer to start returning the specified tokens. /// /// If DisableMacroExpansion is true, tokens lexed from the token stream will /// not be subject to further macro expansion. Otherwise, these tokens will /// be re-macro-expanded when/if expansion is enabled. /// /// If OwnsTokens is false, this method assumes that the specified stream of /// tokens has a permanent owner somewhere, so they do not need to be copied. /// If it is true, it assumes the array of tokens is allocated with new[] and /// must be freed. /// void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks, bool DisableMacroExpansion, bool OwnsTokens, bool IsReinject) { if (CurLexerKind == CLK_CachingLexer) { if (CachedLexPos < CachedTokens.size()) { assert(IsReinject && "new tokens in the middle of cached stream"); // We're entering tokens into the middle of our cached token stream. We // can't represent that, so just insert the tokens into the buffer. CachedTokens.insert(CachedTokens.begin() + CachedLexPos, Toks, Toks + NumToks); if (OwnsTokens) delete [] Toks; return; } // New tokens are at the end of the cached token sequnece; insert the // token stream underneath the caching lexer. ExitCachingLexMode(); EnterTokenStream(Toks, NumToks, DisableMacroExpansion, OwnsTokens, IsReinject); EnterCachingLexMode(); return; } // Create a macro expander to expand from the specified token stream. std::unique_ptr TokLexer; if (NumCachedTokenLexers == 0) { TokLexer = std::make_unique( Toks, NumToks, DisableMacroExpansion, OwnsTokens, IsReinject, *this); } else { TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]); TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens, IsReinject); } // Save our current state. PushIncludeMacroStack(); CurDirLookup = nullptr; CurTokenLexer = std::move(TokLexer); if (CurLexerKind != CLK_LexAfterModuleImport) CurLexerKind = CLK_TokenLexer; } /// Compute the relative path that names the given file relative to /// the given directory. static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir, const FileEntry *File, SmallString<128> &Result) { Result.clear(); StringRef FilePath = File->getDir()->getName(); StringRef Path = FilePath; while (!Path.empty()) { if (auto CurDir = FM.getDirectory(Path)) { if (*CurDir == Dir) { Result = FilePath.substr(Path.size()); llvm::sys::path::append(Result, llvm::sys::path::filename(File->getName())); return; } } Path = llvm::sys::path::parent_path(Path); } Result = File->getName(); } void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) { if (CurTokenLexer) { CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result); return; } if (CurLexer) { CurLexer->PropagateLineStartLeadingSpaceInfo(Result); return; } // FIXME: Handle other kinds of lexers? It generally shouldn't matter, // but it might if they're empty? } /// Determine the location to use as the end of the buffer for a lexer. /// /// If the file ends with a newline, form the EOF token on the newline itself, /// rather than "on the line following it", which doesn't exist. This makes /// diagnostics relating to the end of file include the last file that the user /// actually typed, which is goodness. const char *Preprocessor::getCurLexerEndPos() { const char *EndPos = CurLexer->BufferEnd; if (EndPos != CurLexer->BufferStart && (EndPos[-1] == '\n' || EndPos[-1] == '\r')) { --EndPos; // Handle \n\r and \r\n: if (EndPos != CurLexer->BufferStart && (EndPos[-1] == '\n' || EndPos[-1] == '\r') && EndPos[-1] != EndPos[0]) --EndPos; } return EndPos; } static void collectAllSubModulesWithUmbrellaHeader( const Module &Mod, SmallVectorImpl &SubMods) { if (Mod.getUmbrellaHeader()) SubMods.push_back(&Mod); for (auto *M : Mod.submodules()) collectAllSubModulesWithUmbrellaHeader(*M, SubMods); } void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) { assert(Mod.getUmbrellaHeader() && "Module must use umbrella header"); SourceLocation StartLoc = SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID()); if (getDiagnostics().isIgnored(diag::warn_uncovered_module_header, StartLoc)) return; ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap(); const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry; llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem(); std::error_code EC; for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC), End; Entry != End && !EC; Entry.increment(EC)) { using llvm::StringSwitch; // Check whether this entry has an extension typically associated with // headers. if (!StringSwitch(llvm::sys::path::extension(Entry->path())) .Cases(".h", ".H", ".hh", ".hpp", true) .Default(false)) continue; if (auto Header = getFileManager().getFile(Entry->path())) if (!getSourceManager().hasFileInfo(*Header)) { if (!ModMap.isHeaderInUnavailableModule(*Header)) { // Find the relative path that would access this header. SmallString<128> RelativePath; computeRelativePath(FileMgr, Dir, *Header, RelativePath); Diag(StartLoc, diag::warn_uncovered_module_header) << Mod.getFullModuleName() << RelativePath; } } } } /// HandleEndOfFile - This callback is invoked when the lexer hits the end of /// the current file. This either returns the EOF token or pops a level off /// the include stack and keeps going. bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) { assert(!CurTokenLexer && "Ending a file when currently in a macro!"); // If we have an unclosed module region from a pragma at the end of a // module, complain and close it now. const bool LeavingSubmodule = CurLexer && CurLexerSubmodule; if ((LeavingSubmodule || IncludeMacroStack.empty()) && !BuildingSubmoduleStack.empty() && BuildingSubmoduleStack.back().IsPragma) { Diag(BuildingSubmoduleStack.back().ImportLoc, diag::err_pp_module_begin_without_module_end); Module *M = LeaveSubmodule(/*ForPragma*/true); Result.startToken(); const char *EndPos = getCurLexerEndPos(); CurLexer->BufferPtr = EndPos; CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end); Result.setAnnotationEndLoc(Result.getLocation()); Result.setAnnotationValue(M); return true; } // See if this file had a controlling macro. if (CurPPLexer) { // Not ending a macro, ignore it. if (const IdentifierInfo *ControllingMacro = CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) { // Okay, this has a controlling macro, remember in HeaderFileInfo. if (const FileEntry *FE = CurPPLexer->getFileEntry()) { HeaderInfo.SetFileControllingMacro(FE, ControllingMacro); if (MacroInfo *MI = getMacroInfo(const_cast(ControllingMacro))) MI->setUsedForHeaderGuard(true); if (const IdentifierInfo *DefinedMacro = CurPPLexer->MIOpt.GetDefinedMacro()) { if (!isMacroDefined(ControllingMacro) && DefinedMacro != ControllingMacro && HeaderInfo.FirstTimeLexingFile(FE)) { // If the edit distance between the two macros is more than 50%, // DefinedMacro may not be header guard, or can be header guard of // another header file. Therefore, it maybe defining something // completely different. This can be observed in the wild when // handling feature macros or header guards in different files. const StringRef ControllingMacroName = ControllingMacro->getName(); const StringRef DefinedMacroName = DefinedMacro->getName(); const size_t MaxHalfLength = std::max(ControllingMacroName.size(), DefinedMacroName.size()) / 2; const unsigned ED = ControllingMacroName.edit_distance( DefinedMacroName, true, MaxHalfLength); if (ED <= MaxHalfLength) { // Emit a warning for a bad header guard. Diag(CurPPLexer->MIOpt.GetMacroLocation(), diag::warn_header_guard) << CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro; Diag(CurPPLexer->MIOpt.GetDefinedLocation(), diag::note_header_guard) << CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro << ControllingMacro << FixItHint::CreateReplacement( CurPPLexer->MIOpt.GetDefinedLocation(), ControllingMacro->getName()); } } } } } } // Complain about reaching a true EOF within arc_cf_code_audited. // We don't want to complain about reaching the end of a macro // instantiation or a _Pragma. if (PragmaARCCFCodeAuditedInfo.second.isValid() && !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) { Diag(PragmaARCCFCodeAuditedInfo.second, diag::err_pp_eof_in_arc_cf_code_audited); // Recover by leaving immediately. PragmaARCCFCodeAuditedInfo = {nullptr, SourceLocation()}; } // Complain about reaching a true EOF within assume_nonnull. // We don't want to complain about reaching the end of a macro // instantiation or a _Pragma. if (PragmaAssumeNonNullLoc.isValid() && !isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) { Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull); // Recover by leaving immediately. PragmaAssumeNonNullLoc = SourceLocation(); } bool LeavingPCHThroughHeader = false; // If this is a #include'd file, pop it off the include stack and continue // lexing the #includer file. if (!IncludeMacroStack.empty()) { // If we lexed the code-completion file, act as if we reached EOF. if (isCodeCompletionEnabled() && CurPPLexer && SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) == CodeCompletionFileLoc) { assert(CurLexer && "Got EOF but no current lexer set!"); Result.startToken(); CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof); CurLexer.reset(); CurPPLexer = nullptr; recomputeCurLexerKind(); return true; } if (!isEndOfMacro && CurPPLexer && (SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid() || // Predefines file doesn't have a valid include location. (PredefinesFileID.isValid() && CurPPLexer->getFileID() == PredefinesFileID))) { // Notify SourceManager to record the number of FileIDs that were created // during lexing of the #include'd file. unsigned NumFIDs = SourceMgr.local_sloc_entry_size() - CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/; SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs); } bool ExitedFromPredefinesFile = false; FileID ExitedFID; if (!isEndOfMacro && CurPPLexer) { ExitedFID = CurPPLexer->getFileID(); assert(PredefinesFileID.isValid() && "HandleEndOfFile is called before PredefinesFileId is set"); ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID); } if (LeavingSubmodule) { // We're done with this submodule. Module *M = LeaveSubmodule(/*ForPragma*/false); // Notify the parser that we've left the module. const char *EndPos = getCurLexerEndPos(); Result.startToken(); CurLexer->BufferPtr = EndPos; CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end); Result.setAnnotationEndLoc(Result.getLocation()); Result.setAnnotationValue(M); } bool FoundPCHThroughHeader = false; if (CurPPLexer && creatingPCHWithThroughHeader() && isPCHThroughHeader( SourceMgr.getFileEntryForID(CurPPLexer->getFileID()))) FoundPCHThroughHeader = true; // We're done with the #included file. RemoveTopOfLexerStack(); // Propagate info about start-of-line/leading white-space/etc. PropagateLineStartLeadingSpaceInfo(Result); // Notify the client, if desired, that we are in a new source file. if (Callbacks && !isEndOfMacro && CurPPLexer) { SrcMgr::CharacteristicKind FileType = SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation()); Callbacks->FileChanged(CurPPLexer->getSourceLocation(), PPCallbacks::ExitFile, FileType, ExitedFID); } // Restore conditional stack from the preamble right after exiting from the // predefines file. if (ExitedFromPredefinesFile) replayPreambleConditionalStack(); if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader && (isInPrimaryFile() || CurPPLexer->getFileID() == getPredefinesFileID())) { // Leaving the through header. Continue directly to end of main file // processing. LeavingPCHThroughHeader = true; } else { // Client should lex another token unless we generated an EOM. return LeavingSubmodule; } } // If this is the end of the main file, form an EOF token. assert(CurLexer && "Got EOF but no current lexer set!"); const char *EndPos = getCurLexerEndPos(); Result.startToken(); CurLexer->BufferPtr = EndPos; CurLexer->FormTokenWithChars(Result, EndPos, tok::eof); if (isCodeCompletionEnabled()) { // Inserting the code-completion point increases the source buffer by 1, // but the main FileID was created before inserting the point. // Compensate by reducing the EOF location by 1, otherwise the location // will point to the next FileID. // FIXME: This is hacky, the code-completion point should probably be // inserted before the main FileID is created. if (CurLexer->getFileLoc() == CodeCompletionFileLoc) Result.setLocation(Result.getLocation().getLocWithOffset(-1)); } if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) { // Reached the end of the compilation without finding the through header. Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen) << PPOpts->PCHThroughHeader << 0; } if (!isIncrementalProcessingEnabled()) // We're done with lexing. CurLexer.reset(); if (!isIncrementalProcessingEnabled()) CurPPLexer = nullptr; if (TUKind == TU_Complete) { // This is the end of the top-level file. 'WarnUnusedMacroLocs' has // collected all macro locations that we need to warn because they are not // used. for (WarnUnusedMacroLocsTy::iterator I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end(); I!=E; ++I) Diag(*I, diag::pp_macro_not_used); } // If we are building a module that has an umbrella header, make sure that // each of the headers within the directory, including all submodules, is // covered by the umbrella header was actually included by the umbrella // header. if (Module *Mod = getCurrentModule()) { llvm::SmallVector AllMods; collectAllSubModulesWithUmbrellaHeader(*Mod, AllMods); for (auto *M : AllMods) diagnoseMissingHeaderInUmbrellaDir(*M); } return true; } /// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer /// hits the end of its token stream. bool Preprocessor::HandleEndOfTokenLexer(Token &Result) { assert(CurTokenLexer && !CurPPLexer && "Ending a macro when currently in a #include file!"); if (!MacroExpandingLexersStack.empty() && MacroExpandingLexersStack.back().first == CurTokenLexer.get()) removeCachedMacroExpandedTokensOfLastLexer(); // Delete or cache the now-dead macro expander. if (NumCachedTokenLexers == TokenLexerCacheSize) CurTokenLexer.reset(); else TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer); // Handle this like a #include file being popped off the stack. return HandleEndOfFile(Result, true); } /// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the /// lexer stack. This should only be used in situations where the current /// state of the top-of-stack lexer is unknown. void Preprocessor::RemoveTopOfLexerStack() { assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load"); if (CurTokenLexer) { // Delete or cache the now-dead macro expander. if (NumCachedTokenLexers == TokenLexerCacheSize) CurTokenLexer.reset(); else TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer); } PopIncludeMacroStack(); } /// HandleMicrosoftCommentPaste - When the macro expander pastes together a /// comment (/##/) in microsoft mode, this method handles updating the current /// state, returning the token on the next source line. void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) { assert(CurTokenLexer && !CurPPLexer && "Pasted comment can only be formed from macro"); // We handle this by scanning for the closest real lexer, switching it to // raw mode and preprocessor mode. This will cause it to return \n as an // explicit EOD token. PreprocessorLexer *FoundLexer = nullptr; bool LexerWasInPPMode = false; for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) { if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer. // Once we find a real lexer, mark it as raw mode (disabling macro // expansions) and preprocessor mode (return EOD). We know that the lexer // was *not* in raw mode before, because the macro that the comment came // from was expanded. However, it could have already been in preprocessor // mode (#if COMMENT) in which case we have to return it to that mode and // return EOD. FoundLexer = ISI.ThePPLexer; FoundLexer->LexingRawMode = true; LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective; FoundLexer->ParsingPreprocessorDirective = true; break; } // Okay, we either found and switched over the lexer, or we didn't find a // lexer. In either case, finish off the macro the comment came from, getting // the next token. if (!HandleEndOfTokenLexer(Tok)) Lex(Tok); // Discarding comments as long as we don't have EOF or EOD. This 'comments // out' the rest of the line, including any tokens that came from other macros // that were active, as in: // #define submacro a COMMENT b // submacro c // which should lex to 'a' only: 'b' and 'c' should be removed. while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof)) Lex(Tok); // If we got an eod token, then we successfully found the end of the line. if (Tok.is(tok::eod)) { assert(FoundLexer && "Can't get end of line without an active lexer"); // Restore the lexer back to normal mode instead of raw mode. FoundLexer->LexingRawMode = false; // If the lexer was already in preprocessor mode, just return the EOD token // to finish the preprocessor line. if (LexerWasInPPMode) return; // Otherwise, switch out of PP mode and return the next lexed token. FoundLexer->ParsingPreprocessorDirective = false; return Lex(Tok); } // If we got an EOF token, then we reached the end of the token stream but // didn't find an explicit \n. This can only happen if there was no lexer // active (an active lexer would return EOD at EOF if there was no \n in // preprocessor directive mode), so just return EOF as our token. assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode"); } void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc, bool ForPragma) { if (!getLangOpts().ModulesLocalVisibility) { // Just track that we entered this submodule. BuildingSubmoduleStack.push_back( BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState, PendingModuleMacroNames.size())); if (Callbacks) Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma); return; } // Resolve as much of the module definition as we can now, before we enter // one of its headers. // FIXME: Can we enable Complain here? // FIXME: Can we do this when local visibility is disabled? ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap(); ModMap.resolveExports(M, /*Complain=*/false); ModMap.resolveUses(M, /*Complain=*/false); ModMap.resolveConflicts(M, /*Complain=*/false); // If this is the first time we've entered this module, set up its state. auto R = Submodules.insert(std::make_pair(M, SubmoduleState())); auto &State = R.first->second; bool FirstTime = R.second; if (FirstTime) { // Determine the set of starting macros for this submodule; take these // from the "null" module (the predefines buffer). // // FIXME: If we have local visibility but not modules enabled, the // NullSubmoduleState is polluted by #defines in the top-level source // file. auto &StartingMacros = NullSubmoduleState.Macros; // Restore to the starting state. // FIXME: Do this lazily, when each macro name is first referenced. for (auto &Macro : StartingMacros) { // Skip uninteresting macros. if (!Macro.second.getLatest() && Macro.second.getOverriddenMacros().empty()) continue; MacroState MS(Macro.second.getLatest()); MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros()); State.Macros.insert(std::make_pair(Macro.first, std::move(MS))); } } // Track that we entered this module. BuildingSubmoduleStack.push_back( BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState, PendingModuleMacroNames.size())); if (Callbacks) Callbacks->EnteredSubmodule(M, ImportLoc, ForPragma); // Switch to this submodule as the current submodule. CurSubmoduleState = &State; // This module is visible to itself. if (FirstTime) makeModuleVisible(M, ImportLoc); } bool Preprocessor::needModuleMacros() const { // If we're not within a submodule, we never need to create ModuleMacros. if (BuildingSubmoduleStack.empty()) return false; // If we are tracking module macro visibility even for textually-included // headers, we need ModuleMacros. if (getLangOpts().ModulesLocalVisibility) return true; // Otherwise, we only need module macros if we're actually compiling a module // interface. return getLangOpts().isCompilingModule(); } Module *Preprocessor::LeaveSubmodule(bool ForPragma) { if (BuildingSubmoduleStack.empty() || BuildingSubmoduleStack.back().IsPragma != ForPragma) { assert(ForPragma && "non-pragma module enter/leave mismatch"); return nullptr; } auto &Info = BuildingSubmoduleStack.back(); Module *LeavingMod = Info.M; SourceLocation ImportLoc = Info.ImportLoc; if (!needModuleMacros() || (!getLangOpts().ModulesLocalVisibility && LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) { // If we don't need module macros, or this is not a module for which we // are tracking macro visibility, don't build any, and preserve the list // of pending names for the surrounding submodule. BuildingSubmoduleStack.pop_back(); if (Callbacks) Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma); makeModuleVisible(LeavingMod, ImportLoc); return LeavingMod; } // Create ModuleMacros for any macros defined in this submodule. llvm::SmallPtrSet VisitedMacros; for (unsigned I = Info.OuterPendingModuleMacroNames; I != PendingModuleMacroNames.size(); ++I) { auto *II = const_cast(PendingModuleMacroNames[I]); if (!VisitedMacros.insert(II).second) continue; auto MacroIt = CurSubmoduleState->Macros.find(II); if (MacroIt == CurSubmoduleState->Macros.end()) continue; auto &Macro = MacroIt->second; // Find the starting point for the MacroDirective chain in this submodule. MacroDirective *OldMD = nullptr; auto *OldState = Info.OuterSubmoduleState; if (getLangOpts().ModulesLocalVisibility) OldState = &NullSubmoduleState; if (OldState && OldState != CurSubmoduleState) { // FIXME: It'd be better to start at the state from when we most recently // entered this submodule, but it doesn't really matter. auto &OldMacros = OldState->Macros; auto OldMacroIt = OldMacros.find(II); if (OldMacroIt == OldMacros.end()) OldMD = nullptr; else OldMD = OldMacroIt->second.getLatest(); } // This module may have exported a new macro. If so, create a ModuleMacro // representing that fact. bool ExplicitlyPublic = false; for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) { assert(MD && "broken macro directive chain"); if (auto *VisMD = dyn_cast(MD)) { // The latest visibility directive for a name in a submodule affects // all the directives that come before it. if (VisMD->isPublic()) ExplicitlyPublic = true; else if (!ExplicitlyPublic) // Private with no following public directive: not exported. break; } else { MacroInfo *Def = nullptr; if (DefMacroDirective *DefMD = dyn_cast(MD)) Def = DefMD->getInfo(); // FIXME: Issue a warning if multiple headers for the same submodule // define a macro, rather than silently ignoring all but the first. bool IsNew; // Don't bother creating a module macro if it would represent a #undef // that doesn't override anything. if (Def || !Macro.getOverriddenMacros().empty()) addModuleMacro(LeavingMod, II, Def, Macro.getOverriddenMacros(), IsNew); if (!getLangOpts().ModulesLocalVisibility) { // This macro is exposed to the rest of this compilation as a // ModuleMacro; we don't need to track its MacroDirective any more. Macro.setLatest(nullptr); Macro.setOverriddenMacros(*this, {}); } break; } } } PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames); // FIXME: Before we leave this submodule, we should parse all the other // headers within it. Otherwise, we're left with an inconsistent state // where we've made the module visible but don't yet have its complete // contents. // Put back the outer module's state, if we're tracking it. if (getLangOpts().ModulesLocalVisibility) CurSubmoduleState = Info.OuterSubmoduleState; BuildingSubmoduleStack.pop_back(); if (Callbacks) Callbacks->LeftSubmodule(LeavingMod, ImportLoc, ForPragma); // A nested #include makes the included submodule visible. makeModuleVisible(LeavingMod, ImportLoc); return LeavingMod; }