| //===--- FileManager.cpp - File System Probing and Caching ----------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the FileManager interface. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // TODO: This should index all interesting directories with dirent calls. |
| // getdirentries ? |
| // opendir/readdir_r/closedir ? |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Basic/FileManager.h" |
| #include "clang/Basic/FileSystemStatCache.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/Config/llvm-config.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <algorithm> |
| #include <cassert> |
| #include <climits> |
| #include <cstdint> |
| #include <cstdlib> |
| #include <string> |
| #include <utility> |
| |
| using namespace clang; |
| |
| /// NON_EXISTENT_DIR - A special value distinct from null that is used to |
| /// represent a dir name that doesn't exist on the disk. |
| #define NON_EXISTENT_DIR reinterpret_cast<DirectoryEntry*>((intptr_t)-1) |
| |
| /// NON_EXISTENT_FILE - A special value distinct from null that is used to |
| /// represent a filename that doesn't exist on the disk. |
| #define NON_EXISTENT_FILE reinterpret_cast<FileEntry*>((intptr_t)-1) |
| |
| //===----------------------------------------------------------------------===// |
| // Common logic. |
| //===----------------------------------------------------------------------===// |
| |
| FileManager::FileManager(const FileSystemOptions &FSO, |
| IntrusiveRefCntPtr<vfs::FileSystem> FS) |
| : FS(std::move(FS)), FileSystemOpts(FSO), SeenDirEntries(64), |
| SeenFileEntries(64), NextFileUID(0) { |
| NumDirLookups = NumFileLookups = 0; |
| NumDirCacheMisses = NumFileCacheMisses = 0; |
| |
| // If the caller doesn't provide a virtual file system, just grab the real |
| // file system. |
| if (!this->FS) |
| this->FS = vfs::getRealFileSystem(); |
| } |
| |
| FileManager::~FileManager() = default; |
| |
| void FileManager::addStatCache(std::unique_ptr<FileSystemStatCache> statCache, |
| bool AtBeginning) { |
| assert(statCache && "No stat cache provided?"); |
| if (AtBeginning || !StatCache.get()) { |
| statCache->setNextStatCache(std::move(StatCache)); |
| StatCache = std::move(statCache); |
| return; |
| } |
| |
| FileSystemStatCache *LastCache = StatCache.get(); |
| while (LastCache->getNextStatCache()) |
| LastCache = LastCache->getNextStatCache(); |
| |
| LastCache->setNextStatCache(std::move(statCache)); |
| } |
| |
| void FileManager::removeStatCache(FileSystemStatCache *statCache) { |
| if (!statCache) |
| return; |
| |
| if (StatCache.get() == statCache) { |
| // This is the first stat cache. |
| StatCache = StatCache->takeNextStatCache(); |
| return; |
| } |
| |
| // Find the stat cache in the list. |
| FileSystemStatCache *PrevCache = StatCache.get(); |
| while (PrevCache && PrevCache->getNextStatCache() != statCache) |
| PrevCache = PrevCache->getNextStatCache(); |
| |
| assert(PrevCache && "Stat cache not found for removal"); |
| PrevCache->setNextStatCache(statCache->takeNextStatCache()); |
| } |
| |
| void FileManager::clearStatCaches() { |
| StatCache.reset(); |
| } |
| |
| /// \brief Retrieve the directory that the given file name resides in. |
| /// Filename can point to either a real file or a virtual file. |
| static const DirectoryEntry *getDirectoryFromFile(FileManager &FileMgr, |
| StringRef Filename, |
| bool CacheFailure) { |
| if (Filename.empty()) |
| return nullptr; |
| |
| if (llvm::sys::path::is_separator(Filename[Filename.size() - 1])) |
| return nullptr; // If Filename is a directory. |
| |
| StringRef DirName = llvm::sys::path::parent_path(Filename); |
| // Use the current directory if file has no path component. |
| if (DirName.empty()) |
| DirName = "."; |
| |
| return FileMgr.getDirectory(DirName, CacheFailure); |
| } |
| |
| /// Add all ancestors of the given path (pointing to either a file or |
| /// a directory) as virtual directories. |
| void FileManager::addAncestorsAsVirtualDirs(StringRef Path) { |
| StringRef DirName = llvm::sys::path::parent_path(Path); |
| if (DirName.empty()) |
| DirName = "."; |
| |
| auto &NamedDirEnt = |
| *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first; |
| |
| // When caching a virtual directory, we always cache its ancestors |
| // at the same time. Therefore, if DirName is already in the cache, |
| // we don't need to recurse as its ancestors must also already be in |
| // the cache. |
| if (NamedDirEnt.second && NamedDirEnt.second != NON_EXISTENT_DIR) |
| return; |
| |
| // Add the virtual directory to the cache. |
| auto UDE = llvm::make_unique<DirectoryEntry>(); |
| UDE->Name = NamedDirEnt.first(); |
| NamedDirEnt.second = UDE.get(); |
| VirtualDirectoryEntries.push_back(std::move(UDE)); |
| |
| // Recursively add the other ancestors. |
| addAncestorsAsVirtualDirs(DirName); |
| } |
| |
| const DirectoryEntry *FileManager::getDirectory(StringRef DirName, |
| bool CacheFailure) { |
| // stat doesn't like trailing separators except for root directory. |
| // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'. |
| // (though it can strip '\\') |
| if (DirName.size() > 1 && |
| DirName != llvm::sys::path::root_path(DirName) && |
| llvm::sys::path::is_separator(DirName.back())) |
| DirName = DirName.substr(0, DirName.size()-1); |
| #ifdef LLVM_ON_WIN32 |
| // Fixing a problem with "clang C:test.c" on Windows. |
| // Stat("C:") does not recognize "C:" as a valid directory |
| std::string DirNameStr; |
| if (DirName.size() > 1 && DirName.back() == ':' && |
| DirName.equals_lower(llvm::sys::path::root_name(DirName))) { |
| DirNameStr = DirName.str() + '.'; |
| DirName = DirNameStr; |
| } |
| #endif |
| |
| ++NumDirLookups; |
| auto &NamedDirEnt = |
| *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first; |
| |
| // See if there was already an entry in the map. Note that the map |
| // contains both virtual and real directories. |
| if (NamedDirEnt.second) |
| return NamedDirEnt.second == NON_EXISTENT_DIR ? nullptr |
| : NamedDirEnt.second; |
| |
| ++NumDirCacheMisses; |
| |
| // By default, initialize it to invalid. |
| NamedDirEnt.second = NON_EXISTENT_DIR; |
| |
| // Get the null-terminated directory name as stored as the key of the |
| // SeenDirEntries map. |
| StringRef InterndDirName = NamedDirEnt.first(); |
| |
| // Check to see if the directory exists. |
| FileData Data; |
| if (getStatValue(InterndDirName, Data, false, nullptr /*directory lookup*/)) { |
| // There's no real directory at the given path. |
| if (!CacheFailure) |
| SeenDirEntries.erase(DirName); |
| return nullptr; |
| } |
| |
| // It exists. See if we have already opened a directory with the |
| // same inode (this occurs on Unix-like systems when one dir is |
| // symlinked to another, for example) or the same path (on |
| // Windows). |
| DirectoryEntry &UDE = UniqueRealDirs[Data.UniqueID]; |
| |
| NamedDirEnt.second = &UDE; |
| if (UDE.getName().empty()) { |
| // We don't have this directory yet, add it. We use the string |
| // key from the SeenDirEntries map as the string. |
| UDE.Name = InterndDirName; |
| } |
| |
| return &UDE; |
| } |
| |
| const FileEntry *FileManager::getFile(StringRef Filename, bool openFile, |
| bool CacheFailure) { |
| ++NumFileLookups; |
| |
| // See if there is already an entry in the map. |
| auto &NamedFileEnt = |
| *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first; |
| |
| // See if there is already an entry in the map. |
| if (NamedFileEnt.second) |
| return NamedFileEnt.second == NON_EXISTENT_FILE ? nullptr |
| : NamedFileEnt.second; |
| |
| ++NumFileCacheMisses; |
| |
| // By default, initialize it to invalid. |
| NamedFileEnt.second = NON_EXISTENT_FILE; |
| |
| // Get the null-terminated file name as stored as the key of the |
| // SeenFileEntries map. |
| StringRef InterndFileName = NamedFileEnt.first(); |
| |
| // Look up the directory for the file. When looking up something like |
| // sys/foo.h we'll discover all of the search directories that have a 'sys' |
| // subdirectory. This will let us avoid having to waste time on known-to-fail |
| // searches when we go to find sys/bar.h, because all the search directories |
| // without a 'sys' subdir will get a cached failure result. |
| const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename, |
| CacheFailure); |
| if (DirInfo == nullptr) { // Directory doesn't exist, file can't exist. |
| if (!CacheFailure) |
| SeenFileEntries.erase(Filename); |
| |
| return nullptr; |
| } |
| |
| // FIXME: Use the directory info to prune this, before doing the stat syscall. |
| // FIXME: This will reduce the # syscalls. |
| |
| // Nope, there isn't. Check to see if the file exists. |
| std::unique_ptr<vfs::File> F; |
| FileData Data; |
| if (getStatValue(InterndFileName, Data, true, openFile ? &F : nullptr)) { |
| // There's no real file at the given path. |
| if (!CacheFailure) |
| SeenFileEntries.erase(Filename); |
| |
| return nullptr; |
| } |
| |
| assert((openFile || !F) && "undesired open file"); |
| |
| // It exists. See if we have already opened a file with the same inode. |
| // This occurs when one dir is symlinked to another, for example. |
| FileEntry &UFE = UniqueRealFiles[Data.UniqueID]; |
| |
| NamedFileEnt.second = &UFE; |
| |
| // If the name returned by getStatValue is different than Filename, re-intern |
| // the name. |
| if (Data.Name != Filename) { |
| auto &NamedFileEnt = |
| *SeenFileEntries.insert(std::make_pair(Data.Name, nullptr)).first; |
| if (!NamedFileEnt.second) |
| NamedFileEnt.second = &UFE; |
| else |
| assert(NamedFileEnt.second == &UFE && |
| "filename from getStatValue() refers to wrong file"); |
| InterndFileName = NamedFileEnt.first().data(); |
| } |
| |
| if (UFE.isValid()) { // Already have an entry with this inode, return it. |
| |
| // FIXME: this hack ensures that if we look up a file by a virtual path in |
| // the VFS that the getDir() will have the virtual path, even if we found |
| // the file by a 'real' path first. This is required in order to find a |
| // module's structure when its headers/module map are mapped in the VFS. |
| // We should remove this as soon as we can properly support a file having |
| // multiple names. |
| if (DirInfo != UFE.Dir && Data.IsVFSMapped) |
| UFE.Dir = DirInfo; |
| |
| // Always update the name to use the last name by which a file was accessed. |
| // FIXME: Neither this nor always using the first name is correct; we want |
| // to switch towards a design where we return a FileName object that |
| // encapsulates both the name by which the file was accessed and the |
| // corresponding FileEntry. |
| UFE.Name = InterndFileName; |
| |
| return &UFE; |
| } |
| |
| // Otherwise, we don't have this file yet, add it. |
| UFE.Name = InterndFileName; |
| UFE.Size = Data.Size; |
| UFE.ModTime = Data.ModTime; |
| UFE.Dir = DirInfo; |
| UFE.UID = NextFileUID++; |
| UFE.UniqueID = Data.UniqueID; |
| UFE.IsNamedPipe = Data.IsNamedPipe; |
| UFE.InPCH = Data.InPCH; |
| UFE.File = std::move(F); |
| UFE.IsValid = true; |
| if (UFE.File) |
| if (auto RealPathName = UFE.File->getName()) |
| UFE.RealPathName = *RealPathName; |
| return &UFE; |
| } |
| |
| const FileEntry * |
| FileManager::getVirtualFile(StringRef Filename, off_t Size, |
| time_t ModificationTime) { |
| ++NumFileLookups; |
| |
| // See if there is already an entry in the map. |
| auto &NamedFileEnt = |
| *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first; |
| |
| // See if there is already an entry in the map. |
| if (NamedFileEnt.second && NamedFileEnt.second != NON_EXISTENT_FILE) |
| return NamedFileEnt.second; |
| |
| ++NumFileCacheMisses; |
| |
| // By default, initialize it to invalid. |
| NamedFileEnt.second = NON_EXISTENT_FILE; |
| |
| addAncestorsAsVirtualDirs(Filename); |
| FileEntry *UFE = nullptr; |
| |
| // Now that all ancestors of Filename are in the cache, the |
| // following call is guaranteed to find the DirectoryEntry from the |
| // cache. |
| const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename, |
| /*CacheFailure=*/true); |
| assert(DirInfo && |
| "The directory of a virtual file should already be in the cache."); |
| |
| // Check to see if the file exists. If so, drop the virtual file |
| FileData Data; |
| const char *InterndFileName = NamedFileEnt.first().data(); |
| if (getStatValue(InterndFileName, Data, true, nullptr) == 0) { |
| Data.Size = Size; |
| Data.ModTime = ModificationTime; |
| UFE = &UniqueRealFiles[Data.UniqueID]; |
| |
| NamedFileEnt.second = UFE; |
| |
| // If we had already opened this file, close it now so we don't |
| // leak the descriptor. We're not going to use the file |
| // descriptor anyway, since this is a virtual file. |
| if (UFE->File) |
| UFE->closeFile(); |
| |
| // If we already have an entry with this inode, return it. |
| if (UFE->isValid()) |
| return UFE; |
| |
| UFE->UniqueID = Data.UniqueID; |
| UFE->IsNamedPipe = Data.IsNamedPipe; |
| UFE->InPCH = Data.InPCH; |
| } |
| |
| if (!UFE) { |
| VirtualFileEntries.push_back(llvm::make_unique<FileEntry>()); |
| UFE = VirtualFileEntries.back().get(); |
| NamedFileEnt.second = UFE; |
| } |
| |
| UFE->Name = InterndFileName; |
| UFE->Size = Size; |
| UFE->ModTime = ModificationTime; |
| UFE->Dir = DirInfo; |
| UFE->UID = NextFileUID++; |
| UFE->IsValid = true; |
| UFE->File.reset(); |
| return UFE; |
| } |
| |
| bool FileManager::FixupRelativePath(SmallVectorImpl<char> &path) const { |
| StringRef pathRef(path.data(), path.size()); |
| |
| if (FileSystemOpts.WorkingDir.empty() |
| || llvm::sys::path::is_absolute(pathRef)) |
| return false; |
| |
| SmallString<128> NewPath(FileSystemOpts.WorkingDir); |
| llvm::sys::path::append(NewPath, pathRef); |
| path = NewPath; |
| return true; |
| } |
| |
| bool FileManager::makeAbsolutePath(SmallVectorImpl<char> &Path) const { |
| bool Changed = FixupRelativePath(Path); |
| |
| if (!llvm::sys::path::is_absolute(StringRef(Path.data(), Path.size()))) { |
| FS->makeAbsolute(Path); |
| Changed = true; |
| } |
| |
| return Changed; |
| } |
| |
| llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> |
| FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile, |
| bool ShouldCloseOpenFile) { |
| uint64_t FileSize = Entry->getSize(); |
| // If there's a high enough chance that the file have changed since we |
| // got its size, force a stat before opening it. |
| if (isVolatile) |
| FileSize = -1; |
| |
| StringRef Filename = Entry->getName(); |
| // If the file is already open, use the open file descriptor. |
| if (Entry->File) { |
| auto Result = |
| Entry->File->getBuffer(Filename, FileSize, |
| /*RequiresNullTerminator=*/true, isVolatile); |
| // FIXME: we need a set of APIs that can make guarantees about whether a |
| // FileEntry is open or not. |
| if (ShouldCloseOpenFile) |
| Entry->closeFile(); |
| return Result; |
| } |
| |
| // Otherwise, open the file. |
| |
| if (FileSystemOpts.WorkingDir.empty()) |
| return FS->getBufferForFile(Filename, FileSize, |
| /*RequiresNullTerminator=*/true, isVolatile); |
| |
| SmallString<128> FilePath(Entry->getName()); |
| FixupRelativePath(FilePath); |
| return FS->getBufferForFile(FilePath, FileSize, |
| /*RequiresNullTerminator=*/true, isVolatile); |
| } |
| |
| llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> |
| FileManager::getBufferForFile(StringRef Filename) { |
| if (FileSystemOpts.WorkingDir.empty()) |
| return FS->getBufferForFile(Filename); |
| |
| SmallString<128> FilePath(Filename); |
| FixupRelativePath(FilePath); |
| return FS->getBufferForFile(FilePath.c_str()); |
| } |
| |
| /// getStatValue - Get the 'stat' information for the specified path, |
| /// using the cache to accelerate it if possible. This returns true |
| /// if the path points to a virtual file or does not exist, or returns |
| /// false if it's an existent real file. If FileDescriptor is NULL, |
| /// do directory look-up instead of file look-up. |
| bool FileManager::getStatValue(StringRef Path, FileData &Data, bool isFile, |
| std::unique_ptr<vfs::File> *F) { |
| // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be |
| // absolute! |
| if (FileSystemOpts.WorkingDir.empty()) |
| return FileSystemStatCache::get(Path, Data, isFile, F,StatCache.get(), *FS); |
| |
| SmallString<128> FilePath(Path); |
| FixupRelativePath(FilePath); |
| |
| return FileSystemStatCache::get(FilePath.c_str(), Data, isFile, F, |
| StatCache.get(), *FS); |
| } |
| |
| bool FileManager::getNoncachedStatValue(StringRef Path, |
| vfs::Status &Result) { |
| SmallString<128> FilePath(Path); |
| FixupRelativePath(FilePath); |
| |
| llvm::ErrorOr<vfs::Status> S = FS->status(FilePath.c_str()); |
| if (!S) |
| return true; |
| Result = *S; |
| return false; |
| } |
| |
| void FileManager::invalidateCache(const FileEntry *Entry) { |
| assert(Entry && "Cannot invalidate a NULL FileEntry"); |
| |
| SeenFileEntries.erase(Entry->getName()); |
| |
| // FileEntry invalidation should not block future optimizations in the file |
| // caches. Possible alternatives are cache truncation (invalidate last N) or |
| // invalidation of the whole cache. |
| UniqueRealFiles.erase(Entry->getUniqueID()); |
| } |
| |
| void FileManager::GetUniqueIDMapping( |
| SmallVectorImpl<const FileEntry *> &UIDToFiles) const { |
| UIDToFiles.clear(); |
| UIDToFiles.resize(NextFileUID); |
| |
| // Map file entries |
| for (llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator>::const_iterator |
| FE = SeenFileEntries.begin(), FEEnd = SeenFileEntries.end(); |
| FE != FEEnd; ++FE) |
| if (FE->getValue() && FE->getValue() != NON_EXISTENT_FILE) |
| UIDToFiles[FE->getValue()->getUID()] = FE->getValue(); |
| |
| // Map virtual file entries |
| for (const auto &VFE : VirtualFileEntries) |
| if (VFE && VFE.get() != NON_EXISTENT_FILE) |
| UIDToFiles[VFE->getUID()] = VFE.get(); |
| } |
| |
| void FileManager::modifyFileEntry(FileEntry *File, |
| off_t Size, time_t ModificationTime) { |
| File->Size = Size; |
| File->ModTime = ModificationTime; |
| } |
| |
| StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) { |
| // FIXME: use llvm::sys::fs::canonical() when it gets implemented |
| llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known |
| = CanonicalDirNames.find(Dir); |
| if (Known != CanonicalDirNames.end()) |
| return Known->second; |
| |
| StringRef CanonicalName(Dir->getName()); |
| |
| #ifdef LLVM_ON_UNIX |
| char CanonicalNameBuf[PATH_MAX]; |
| if (realpath(Dir->getName().str().c_str(), CanonicalNameBuf)) |
| CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage); |
| #else |
| SmallString<256> CanonicalNameBuf(CanonicalName); |
| llvm::sys::fs::make_absolute(CanonicalNameBuf); |
| llvm::sys::path::native(CanonicalNameBuf); |
| // We've run into needing to remove '..' here in the wild though, so |
| // remove it. |
| // On Windows, symlinks are significantly less prevalent, so removing |
| // '..' is pretty safe. |
| // Ideally we'd have an equivalent of `realpath` and could implement |
| // sys::fs::canonical across all the platforms. |
| llvm::sys::path::remove_dots(CanonicalNameBuf, /* remove_dot_dot */ true); |
| CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage); |
| #endif |
| |
| CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName)); |
| return CanonicalName; |
| } |
| |
| void FileManager::PrintStats() const { |
| llvm::errs() << "\n*** File Manager Stats:\n"; |
| llvm::errs() << UniqueRealFiles.size() << " real files found, " |
| << UniqueRealDirs.size() << " real dirs found.\n"; |
| llvm::errs() << VirtualFileEntries.size() << " virtual files found, " |
| << VirtualDirectoryEntries.size() << " virtual dirs found.\n"; |
| llvm::errs() << NumDirLookups << " dir lookups, " |
| << NumDirCacheMisses << " dir cache misses.\n"; |
| llvm::errs() << NumFileLookups << " file lookups, " |
| << NumFileCacheMisses << " file cache misses.\n"; |
| |
| //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups; |
| } |