1 //===--- PrecompiledPreamble.cpp - Build precompiled preambles --*- C++ -*-===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // Helper class to build precompiled preamble.
11 //===----------------------------------------------------------------------===//
28 #include "llvm/Config/llvm-config.h"
49 #warning "Unknown platform. Defaulting to UNIX-style paths for in-memory PCHs"  in getInMemoryPreamblePath()
59   // so we create an in-memory VFS with just that and overlay it on top.  in createVFSOverlayForPreamblePCH()
62   PCHFS->addFile(PCHFilename, 0, std::move(PCHBuffer));  in createVFSOverlayForPreamblePCH()
65   Overlay->pushOverlay(PCHFS);  in createVFSOverlayForPreamblePCH()
69 class PreambleDependencyCollector : public DependencyCollector {
74   // spuriously added by '-isystem' (e.g. to suppress warnings from those
88 class MissingFileCollector : public PPCallbacks {
106     // (We have some false negatives if PP recovered e.g. <foo> -> "foo")  in InclusionDirective()
128         if (IncludingFile->getDir())  in InclusionDirective()
129           NotFoundRelativeTo(IncludingFile->getDir());  in InclusionDirective()
143 class TemporaryFiles {
149   // Disallow constructing the class directly.
198 // so it's not intended to be used outside preamble-handling.
199 class TempPCHFile {
204     // crash-recovery testing, which is the only case where the preamble files  in create()
212     // that we would never get a race condition in a multi-threaded setting  in create()
221       llvm::sys::path::append(TempPath, "preamble-%%%%%%.pch");  in create()
223       // Use the same owner-only file permissions as fs::createTemporaryFile().  in create()
243     TemporaryFiles::getInstance().addFile(this->FilePath);  in TempPCHFile()
249 class PrecompilePreambleAction : public ASTFrontendAction {
263       *FileOS << Buffer->Data;  in setEmittedPreamblePCH()
268     this->HasEmittedPreamblePCH = true;  in setEmittedPreamblePCH()
283   friend class PrecompilePreambleConsumer;
288   std::unique_ptr<llvm::raw_pwrite_stream> FileOS; // null if in-memory
292 class PrecompilePreambleConsumer : public PCHGenerator {
303   bool HandleTopLevelDecl(DeclGroupRef DG) override {  in HandleTopLevelDecl()  argument
304     Action.Callbacks.HandleTopLevelDecl(DG);  in HandleTopLevelDecl()
344 template <class T> bool moveOnNoError(llvm::ErrorOr<T> Val, T &Output) {  in moveOnNoError()
359 class PrecompiledPreamble::PCHStorage {
364     S->File = std::move(File);  in file()
369     S->Memory = std::move(Buf);  in inMemory()
373   enum class Kind { InMemory, TempFile };
383     return File->getFilePath();  in filePath()
387     return StringRef(Memory->Data.data(), Memory->Data.size());  in memoryContents()
390   // Shrink in-memory buffers to fit.
391   // This incurs a copy, but preambles tend to be long-lived.
396     Memory->Data = decltype(Memory->Data)(Memory->Data);  in shrink()
423   FrontendOptions &FrontendOpts = PreambleInvocation->getFrontendOpts();  in Build()
425       PreambleInvocation->getPreprocessorOpts();  in Build()
443   std::vector<char> PreambleBytes(MainFileBuffer->getBufferStart(),  in Build()
444                                   MainFileBuffer->getBufferStart() +  in Build()
451       StoreInMemory ? getInMemoryPreamblePath() : Storage->filePath());  in Build()
465   Clang->setInvocation(std::move(PreambleInvocation));  in Build()
466   Clang->setDiagnostics(&Diagnostics);  in Build()
469   if (!Clang->createTarget())  in Build()
472   if (Clang->getFrontendOpts().Inputs.size() != 1 ||  in Build()
473       Clang->getFrontendOpts().Inputs[0].getKind().getFormat() !=  in Build()
475       Clang->getFrontendOpts().Inputs[0].getKind().getLanguage() ==  in Build()
482   ProcessWarningOptions(Diagnostics, Clang->getDiagnosticOpts());  in Build()
485       createVFSFromCompilerInvocation(Clang->getInvocation(), Diagnostics, VFS);  in Build()
488   Clang->setFileManager(new FileManager(Clang->getFileSystemOpts(), VFS));  in Build()
491   Clang->setSourceManager(  in Build()
492       new SourceManager(Diagnostics, Clang->getFileManager()));  in Build()
495   Clang->addDependencyCollector(PreambleDepCollector);  in Build()
497   Clang->getLangOpts().CompilingPCH = true;  in Build()
502       MainFileBuffer->getBuffer().slice(0, Bounds.Size), MainFilePath);  in Build()
515       /*WritePCHFile=*/Storage->getKind() == PCHStorage::Kind::TempFile,  in Build()
517   if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))  in Build()
520   // Performed after BeginSourceFile to ensure Clang->Preprocessor can be  in Build()
527     Clang->getPreprocessor().addPPCallbacks(std::move(DelegatedPPCallbacks));  in Build()
529     Clang->getPreprocessor().addCommentHandler(CommentHandler);  in Build()
531   Clang->getPreprocessor().addPPCallbacks(  in Build()
533           MissingFiles, Clang->getPreprocessor().getHeaderSearchInfo(),  in Build()
534           Clang->getSourceManager()));  in Build()
536   if (llvm::Error Err = Act->Execute())  in Build()
542   Act->EndSourceFile();  in Build()
544   if (!Act->hasEmittedPreamblePCH())  in Build()
552   SourceManager &SourceMgr = Clang->getSourceManager();  in Build()
553   for (auto &Filename : PreambleDepCollector->getDependencies()) {  in Build()
554     auto MaybeFile = Clang->getFileManager().getOptionalFileRef(Filename);  in Build()
575   Storage->shrink();  in Build()
586   switch (Storage->getKind()) {  in getSize()
588     return Storage->memoryContents().size();  in getSize()
591     if (llvm::sys::fs::file_size(Storage->filePath(), Result))  in getSize()
613       PreambleInvocation->getPreprocessorOpts();  in CanReuse()
617   // the main-file buffer within the precompiled preamble to fit the  in CanReuse()
624   // The preamble has not changed. We may be able to re-use the precompiled  in CanReuse()
652         PreambleFileHash::createForMemoryBuffer(RB.second->getMemBufferRef());  in CanReuse()
670       if (OverridenFileBuffer->second != F.second)  in CanReuse()
685       // This file was remapped; check whether the newly-mapped file  in CanReuse()
687       if (Overridden->second != F.second)  in CanReuse()
704     // consider the preamble out-of-date.  in CanReuse()
706       if (Status->isRegularFile())  in CanReuse()
736   assert(this->Storage != nullptr);  in PrecompiledPreamble()
799     if (VFS == RealFS || VFS->exists(PCHPath))  in setupPreambleStorage()
801     auto Buf = RealFS->getBufferForFile(PCHPath);  in setupPreambleStorage()
809     // We have a slight inconsistency here -- we're using the VFS to  in setupPreambleStorage()
814     // For in-memory preamble, we have to provide a VFS overlay that makes it  in setupPreambleStorage()
828 void PreambleCallbacks::HandleTopLevelDecl(DeclGroupRef DG) {}  in HandleTopLevelDecl()  argument
841   return "build-preamble.error";  in name()