| //===--- FileManager.h - File System Probing and Caching --------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// \file |
| /// Defines the clang::FileManager interface and associated types. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_BASIC_FILEMANAGER_H |
| #define LLVM_CLANG_BASIC_FILEMANAGER_H |
| |
| #include "clang/Basic/FileSystemOptions.h" |
| #include "clang/Basic/LLVM.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/IntrusiveRefCntPtr.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/StringMap.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Support/Allocator.h" |
| #include "llvm/Support/ErrorOr.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/VirtualFileSystem.h" |
| #include <ctime> |
| #include <map> |
| #include <memory> |
| #include <string> |
| |
| namespace llvm { |
| |
| class MemoryBuffer; |
| |
| } // end namespace llvm |
| |
| namespace clang { |
| |
| class FileSystemStatCache; |
| |
| /// Cached information about one directory (either on disk or in |
| /// the virtual file system). |
| class DirectoryEntry { |
| friend class FileManager; |
| |
| StringRef Name; // Name of the directory. |
| |
| public: |
| StringRef getName() const { return Name; } |
| }; |
| |
| /// Cached information about one file (either on disk |
| /// or in the virtual file system). |
| /// |
| /// If the 'File' member is valid, then this FileEntry has an open file |
| /// descriptor for the file. |
| class FileEntry { |
| friend class FileManager; |
| |
| StringRef Name; // Name of the file. |
| std::string RealPathName; // Real path to the file; could be empty. |
| off_t Size; // File size in bytes. |
| time_t ModTime; // Modification time of file. |
| const DirectoryEntry *Dir; // Directory file lives in. |
| unsigned UID; // A unique (small) ID for the file. |
| llvm::sys::fs::UniqueID UniqueID; |
| bool IsNamedPipe; |
| bool IsValid; // Is this \c FileEntry initialized and valid? |
| |
| /// The open file, if it is owned by the \p FileEntry. |
| mutable std::unique_ptr<llvm::vfs::File> File; |
| |
| public: |
| FileEntry() |
| : UniqueID(0, 0), IsNamedPipe(false), IsValid(false) |
| {} |
| |
| FileEntry(const FileEntry &) = delete; |
| FileEntry &operator=(const FileEntry &) = delete; |
| |
| StringRef getName() const { return Name; } |
| StringRef tryGetRealPathName() const { return RealPathName; } |
| bool isValid() const { return IsValid; } |
| off_t getSize() const { return Size; } |
| unsigned getUID() const { return UID; } |
| const llvm::sys::fs::UniqueID &getUniqueID() const { return UniqueID; } |
| time_t getModificationTime() const { return ModTime; } |
| |
| /// Return the directory the file lives in. |
| const DirectoryEntry *getDir() const { return Dir; } |
| |
| bool operator<(const FileEntry &RHS) const { return UniqueID < RHS.UniqueID; } |
| |
| /// Check whether the file is a named pipe (and thus can't be opened by |
| /// the native FileManager methods). |
| bool isNamedPipe() const { return IsNamedPipe; } |
| |
| void closeFile() const { |
| File.reset(); // rely on destructor to close File |
| } |
| |
| // Only for use in tests to see if deferred opens are happening, rather than |
| // relying on RealPathName being empty. |
| bool isOpenForTests() const { return File != nullptr; } |
| }; |
| |
| /// Implements support for file system lookup, file system caching, |
| /// and directory search management. |
| /// |
| /// This also handles more advanced properties, such as uniquing files based |
| /// on "inode", so that a file with two names (e.g. symlinked) will be treated |
| /// as a single file. |
| /// |
| class FileManager : public RefCountedBase<FileManager> { |
| IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS; |
| FileSystemOptions FileSystemOpts; |
| |
| /// Cache for existing real directories. |
| std::map<llvm::sys::fs::UniqueID, DirectoryEntry> UniqueRealDirs; |
| |
| /// Cache for existing real files. |
| std::map<llvm::sys::fs::UniqueID, FileEntry> UniqueRealFiles; |
| |
| /// The virtual directories that we have allocated. |
| /// |
| /// For each virtual file (e.g. foo/bar/baz.cpp), we add all of its parent |
| /// directories (foo/ and foo/bar/) here. |
| SmallVector<std::unique_ptr<DirectoryEntry>, 4> VirtualDirectoryEntries; |
| /// The virtual files that we have allocated. |
| SmallVector<std::unique_ptr<FileEntry>, 4> VirtualFileEntries; |
| |
| /// A cache that maps paths to directory entries (either real or |
| /// virtual) we have looked up |
| /// |
| /// The actual Entries for real directories/files are |
| /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries |
| /// for virtual directories/files are owned by |
| /// VirtualDirectoryEntries/VirtualFileEntries above. |
| /// |
| llvm::StringMap<DirectoryEntry*, llvm::BumpPtrAllocator> SeenDirEntries; |
| |
| /// A cache that maps paths to file entries (either real or |
| /// virtual) we have looked up. |
| /// |
| /// \see SeenDirEntries |
| llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries; |
| |
| /// The canonical names of directories. |
| llvm::DenseMap<const DirectoryEntry *, llvm::StringRef> CanonicalDirNames; |
| |
| /// Storage for canonical names that we have computed. |
| llvm::BumpPtrAllocator CanonicalNameStorage; |
| |
| /// Each FileEntry we create is assigned a unique ID #. |
| /// |
| unsigned NextFileUID; |
| |
| // Statistics. |
| unsigned NumDirLookups, NumFileLookups; |
| unsigned NumDirCacheMisses, NumFileCacheMisses; |
| |
| // Caching. |
| std::unique_ptr<FileSystemStatCache> StatCache; |
| |
| bool getStatValue(StringRef Path, llvm::vfs::Status &Status, bool isFile, |
| std::unique_ptr<llvm::vfs::File> *F); |
| |
| /// Add all ancestors of the given path (pointing to either a file |
| /// or a directory) as virtual directories. |
| void addAncestorsAsVirtualDirs(StringRef Path); |
| |
| /// Fills the RealPathName in file entry. |
| void fillRealPathName(FileEntry *UFE, llvm::StringRef FileName); |
| |
| public: |
| /// Construct a file manager, optionally with a custom VFS. |
| /// |
| /// \param FS if non-null, the VFS to use. Otherwise uses |
| /// llvm::vfs::getRealFileSystem(). |
| FileManager(const FileSystemOptions &FileSystemOpts, |
| IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr); |
| ~FileManager(); |
| |
| /// Installs the provided FileSystemStatCache object within |
| /// the FileManager. |
| /// |
| /// Ownership of this object is transferred to the FileManager. |
| /// |
| /// \param statCache the new stat cache to install. Ownership of this |
| /// object is transferred to the FileManager. |
| void setStatCache(std::unique_ptr<FileSystemStatCache> statCache); |
| |
| /// Removes the FileSystemStatCache object from the manager. |
| void clearStatCache(); |
| |
| /// Lookup, cache, and verify the specified directory (real or |
| /// virtual). |
| /// |
| /// This returns NULL if the directory doesn't exist. |
| /// |
| /// \param CacheFailure If true and the file does not exist, we'll cache |
| /// the failure to find this file. |
| const DirectoryEntry *getDirectory(StringRef DirName, |
| bool CacheFailure = true); |
| |
| /// Lookup, cache, and verify the specified file (real or |
| /// virtual). |
| /// |
| /// This returns NULL if the file doesn't exist. |
| /// |
| /// \param OpenFile if true and the file exists, it will be opened. |
| /// |
| /// \param CacheFailure If true and the file does not exist, we'll cache |
| /// the failure to find this file. |
| const FileEntry *getFile(StringRef Filename, bool OpenFile = false, |
| bool CacheFailure = true); |
| |
| /// Returns the current file system options |
| FileSystemOptions &getFileSystemOpts() { return FileSystemOpts; } |
| const FileSystemOptions &getFileSystemOpts() const { return FileSystemOpts; } |
| |
| llvm::vfs::FileSystem &getVirtualFileSystem() const { return *FS; } |
| |
| /// Retrieve a file entry for a "virtual" file that acts as |
| /// if there were a file with the given name on disk. |
| /// |
| /// The file itself is not accessed. |
| const FileEntry *getVirtualFile(StringRef Filename, off_t Size, |
| time_t ModificationTime); |
| |
| /// Open the specified file as a MemoryBuffer, returning a new |
| /// MemoryBuffer if successful, otherwise returning null. |
| llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> |
| getBufferForFile(const FileEntry *Entry, bool isVolatile = false, |
| bool ShouldCloseOpenFile = true); |
| llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> |
| getBufferForFile(StringRef Filename, bool isVolatile = false); |
| |
| /// Get the 'stat' information for the given \p Path. |
| /// |
| /// If the path is relative, it will be resolved against the WorkingDir of the |
| /// FileManager's FileSystemOptions. |
| /// |
| /// \returns false on success, true on error. |
| bool getNoncachedStatValue(StringRef Path, llvm::vfs::Status &Result); |
| |
| /// Remove the real file \p Entry from the cache. |
| void invalidateCache(const FileEntry *Entry); |
| |
| /// If path is not absolute and FileSystemOptions set the working |
| /// directory, the path is modified to be relative to the given |
| /// working directory. |
| /// \returns true if \c path changed. |
| bool FixupRelativePath(SmallVectorImpl<char> &path) const; |
| |
| /// Makes \c Path absolute taking into account FileSystemOptions and the |
| /// working directory option. |
| /// \returns true if \c Path changed to absolute. |
| bool makeAbsolutePath(SmallVectorImpl<char> &Path) const; |
| |
| /// Produce an array mapping from the unique IDs assigned to each |
| /// file to the corresponding FileEntry pointer. |
| void GetUniqueIDMapping( |
| SmallVectorImpl<const FileEntry *> &UIDToFiles) const; |
| |
| /// Modifies the size and modification time of a previously created |
| /// FileEntry. Use with caution. |
| static void modifyFileEntry(FileEntry *File, off_t Size, |
| time_t ModificationTime); |
| |
| /// Retrieve the canonical name for a given directory. |
| /// |
| /// This is a very expensive operation, despite its results being cached, |
| /// and should only be used when the physical layout of the file system is |
| /// required, which is (almost) never. |
| StringRef getCanonicalName(const DirectoryEntry *Dir); |
| |
| void PrintStats() const; |
| }; |
| |
| } // end namespace clang |
| |
| #endif // LLVM_CLANG_BASIC_FILEMANAGER_H |