From c4436f675d8f5903303fc13d2c2eff2c5800d49b Mon Sep 17 00:00:00 2001 From: Ben Langmuir Date: Wed, 16 Nov 2022 16:07:34 -0800 Subject: [PATCH] [clang] Use InMemoryModuleCache for readASTFileControlBlock NFC When a pcm has already been loaded from disk, reuse it from the InMemoryModuleCache in readASTFileControlBlock. This avoids potentially reading it again. As noted in the FIXME, ideally we would also add the module to the cache if it will be used again later, but that could modify its build state and we do not have enough context currenlty to know if it's correct. Differential Revision: https://reviews.llvm.org/D138160 --- clang/include/clang/Serialization/ASTReader.h | 13 ++++---- clang/lib/Frontend/CompilerInstance.cpp | 3 +- clang/lib/Frontend/FrontendAction.cpp | 5 ++-- clang/lib/Frontend/FrontendActions.cpp | 10 ++++--- clang/lib/Serialization/ASTReader.cpp | 30 ++++++++++++------- .../DependencyScanningWorker.cpp | 2 +- 6 files changed, 39 insertions(+), 24 deletions(-) diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h index 23c67fc8828d..5569c0147bbd 100644 --- a/clang/include/clang/Serialization/ASTReader.h +++ b/clang/include/clang/Serialization/ASTReader.h @@ -1731,16 +1731,17 @@ public: /// Read the control block for the named AST file. /// /// \returns true if an error occurred, false otherwise. - static bool - readASTFileControlBlock(StringRef Filename, FileManager &FileMgr, - const PCHContainerReader &PCHContainerRdr, - bool FindModuleFileExtensions, - ASTReaderListener &Listener, - bool ValidateDiagnosticOptions); + static bool readASTFileControlBlock(StringRef Filename, FileManager &FileMgr, + const InMemoryModuleCache &ModuleCache, + const PCHContainerReader &PCHContainerRdr, + bool FindModuleFileExtensions, + ASTReaderListener &Listener, + bool ValidateDiagnosticOptions); /// Determine whether the given AST file is acceptable to load into a /// translation unit with the given language and target options. static bool isAcceptableASTFile(StringRef Filename, FileManager &FileMgr, + const InMemoryModuleCache &ModuleCache, const PCHContainerReader &PCHContainerRdr, const LangOptions &LangOpts, const TargetOptions &TargetOpts, diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp index 6402f1607485..79bbf375af96 100644 --- a/clang/lib/Frontend/CompilerInstance.cpp +++ b/clang/lib/Frontend/CompilerInstance.cpp @@ -252,7 +252,8 @@ static void collectIncludePCH(CompilerInstance &CI, // used here since we're not interested in validating the PCH at this time, // but only to check whether this is a file containing an AST. if (!ASTReader::readASTFileControlBlock( - Dir->path(), FileMgr, CI.getPCHContainerReader(), + Dir->path(), FileMgr, CI.getModuleCache(), + CI.getPCHContainerReader(), /*FindModuleFileExtensions=*/false, Validator, /*ValidateDiagnosticOptions=*/false)) MDC->addFile(Dir->path()); diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp index 76ef0cb3b405..8fa96be25630 100644 --- a/clang/lib/Frontend/FrontendAction.cpp +++ b/clang/lib/Frontend/FrontendAction.cpp @@ -778,8 +778,9 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI, Dir != DirEnd && !EC; Dir.increment(EC)) { // Check whether this is an acceptable AST file. if (ASTReader::isAcceptableASTFile( - Dir->path(), FileMgr, CI.getPCHContainerReader(), - CI.getLangOpts(), CI.getTargetOpts(), CI.getPreprocessorOpts(), + Dir->path(), FileMgr, CI.getModuleCache(), + CI.getPCHContainerReader(), CI.getLangOpts(), + CI.getTargetOpts(), CI.getPreprocessorOpts(), SpecificModuleCachePath, /*RequireStrictOptionMatches=*/true)) { PPOpts.ImplicitPCHInclude = std::string(Dir->path()); Found = true; diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp index b4ec3892a1b6..dfb7267eb23f 100644 --- a/clang/lib/Frontend/FrontendActions.cpp +++ b/clang/lib/Frontend/FrontendActions.cpp @@ -851,7 +851,8 @@ void DumpModuleInfoAction::ExecuteAction() { assert(isCurrentFileAST() && "dumping non-AST?"); // Set up the output file. std::unique_ptr OutFile; - StringRef OutputFileName = getCompilerInstance().getFrontendOpts().OutputFile; + CompilerInstance &CI = getCompilerInstance(); + StringRef OutputFileName = CI.getFrontendOpts().OutputFile; if (!OutputFileName.empty() && OutputFileName != "-") { std::error_code EC; OutFile.reset(new llvm::raw_fd_ostream(OutputFileName.str(), EC, @@ -861,14 +862,14 @@ void DumpModuleInfoAction::ExecuteAction() { llvm::raw_ostream &Out = OutputStream ? *OutputStream : llvm::outs(); Out << "Information for module file '" << getCurrentFile() << "':\n"; - auto &FileMgr = getCompilerInstance().getFileManager(); + auto &FileMgr = CI.getFileManager(); auto Buffer = FileMgr.getBufferForFile(getCurrentFile()); StringRef Magic = (*Buffer)->getMemBufferRef().getBuffer(); bool IsRaw = (Magic.size() >= 4 && Magic[0] == 'C' && Magic[1] == 'P' && Magic[2] == 'C' && Magic[3] == 'H'); Out << " Module format: " << (IsRaw ? "raw" : "obj") << "\n"; - Preprocessor &PP = getCompilerInstance().getPreprocessor(); + Preprocessor &PP = CI.getPreprocessor(); DumpModuleInfoListener Listener(Out); HeaderSearchOptions &HSOpts = PP.getHeaderSearchInfo().getHeaderSearchOpts(); @@ -966,7 +967,8 @@ void DumpModuleInfoAction::ExecuteAction() { // The reminder of the output is produced from the listener as the AST // FileCcontrolBlock is (re-)parsed. ASTReader::readASTFileControlBlock( - getCurrentFile(), FileMgr, getCompilerInstance().getPCHContainerReader(), + getCurrentFile(), FileMgr, CI.getModuleCache(), + CI.getPCHContainerReader(), /*FindModuleFileExtensions=*/true, Listener, HSOpts.ModulesValidateDiagnosticOptions); } diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp index 7b3d0592f8c0..befd17912cb5 100644 --- a/clang/lib/Serialization/ASTReader.cpp +++ b/clang/lib/Serialization/ASTReader.cpp @@ -5169,19 +5169,28 @@ namespace { bool ASTReader::readASTFileControlBlock( StringRef Filename, FileManager &FileMgr, - const PCHContainerReader &PCHContainerRdr, - bool FindModuleFileExtensions, + const InMemoryModuleCache &ModuleCache, + const PCHContainerReader &PCHContainerRdr, bool FindModuleFileExtensions, ASTReaderListener &Listener, bool ValidateDiagnosticOptions) { // Open the AST file. - // FIXME: This allows use of the VFS; we do not allow use of the - // VFS when actually loading a module. - auto Buffer = FileMgr.getBufferForFile(Filename); + std::unique_ptr OwnedBuffer; + llvm::MemoryBuffer *Buffer = ModuleCache.lookupPCM(Filename); if (!Buffer) { - return true; + // FIXME: We should add the pcm to the InMemoryModuleCache if it could be + // read again later, but we do not have the context here to determine if it + // is safe to change the result of InMemoryModuleCache::getPCMState(). + + // FIXME: This allows use of the VFS; we do not allow use of the + // VFS when actually loading a module. + auto BufferOrErr = FileMgr.getBufferForFile(Filename); + if (!BufferOrErr) + return true; + OwnedBuffer = std::move(*BufferOrErr); + Buffer = OwnedBuffer.get(); } // Initialize the stream - StringRef Bytes = PCHContainerRdr.ExtractPCH(**Buffer); + StringRef Bytes = PCHContainerRdr.ExtractPCH(*Buffer); BitstreamCursor Stream(Bytes); // Sniff for the signature. @@ -5434,6 +5443,7 @@ bool ASTReader::readASTFileControlBlock( } bool ASTReader::isAcceptableASTFile(StringRef Filename, FileManager &FileMgr, + const InMemoryModuleCache &ModuleCache, const PCHContainerReader &PCHContainerRdr, const LangOptions &LangOpts, const TargetOptions &TargetOpts, @@ -5443,9 +5453,9 @@ bool ASTReader::isAcceptableASTFile(StringRef Filename, FileManager &FileMgr, SimplePCHValidator validator(LangOpts, TargetOpts, PPOpts, ExistingModuleCachePath, FileMgr, RequireStrictOptionMatches); - return !readASTFileControlBlock(Filename, FileMgr, PCHContainerRdr, - /*FindModuleFileExtensions=*/false, - validator, + return !readASTFileControlBlock(Filename, FileMgr, ModuleCache, + PCHContainerRdr, + /*FindModuleFileExtensions=*/false, validator, /*ValidateDiagnosticOptions=*/true); } diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp index b7aff9637439..50c42087d2fa 100644 --- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp +++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp @@ -103,7 +103,7 @@ static void visitPrebuiltModule(StringRef PrebuiltModuleFilename, while (!Worklist.empty()) ASTReader::readASTFileControlBlock( - Worklist.pop_back_val(), CI.getFileManager(), + Worklist.pop_back_val(), CI.getFileManager(), CI.getModuleCache(), CI.getPCHContainerReader(), /*FindModuleFileExtensions=*/false, Listener, /*ValidateDiagnosticOptions=*/false);