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//===--- FileManager.h - File System Probing and Caching --------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
/// \file
/// \brief Defines the clang::FileManager interface and associated types.
#include "clang/Basic/FileSystemOptions.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Support/Allocator.h"
// FIXME: Enhance libsystem to support inode and other fields in stat.
#include <sys/types.h>
#ifdef _MSC_VER
typedef unsigned short mode_t;
struct stat;
namespace llvm {
class MemoryBuffer;
namespace sys { class Path; }
namespace clang {
class FileManager;
class FileSystemStatCache;
/// \brief Cached information about one directory (either on disk or in
/// the virtual file system).
class DirectoryEntry {
const char *Name; // Name of the directory.
friend class FileManager;
DirectoryEntry() : Name(0) {}
const char *getName() const { return Name; }
/// \brief Cached information about one file (either on disk
/// or in the virtual file system).
/// If the 'FD' member is valid, then this FileEntry has an open file
/// descriptor for the file.
class FileEntry {
const char *Name; // Name of the file.
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.
dev_t Device; // ID for the device containing the file.
ino_t Inode; // Inode number for the file.
mode_t FileMode; // The file mode as returned by 'stat'.
/// FD - The file descriptor for the file entry if it is opened and owned
/// by the FileEntry. If not, this is set to -1.
mutable int FD;
friend class FileManager;
FileEntry(dev_t device, ino_t inode, mode_t m)
: Name(0), Device(device), Inode(inode), FileMode(m), FD(-1) {}
// Add a default constructor for use with llvm::StringMap
FileEntry() : Name(0), Device(0), Inode(0), FileMode(0), FD(-1) {}
FileEntry(const FileEntry &FE) {
memcpy(this, &FE, sizeof(FE));
assert(FD == -1 && "Cannot copy a file-owning FileEntry");
void operator=(const FileEntry &FE) {
memcpy(this, &FE, sizeof(FE));
assert(FD == -1 && "Cannot assign a file-owning FileEntry");
const char *getName() const { return Name; }
off_t getSize() const { return Size; }
unsigned getUID() const { return UID; }
ino_t getInode() const { return Inode; }
dev_t getDevice() const { return Device; }
time_t getModificationTime() const { return ModTime; }
mode_t getFileMode() const { return FileMode; }
/// \brief Return the directory the file lives in.
const DirectoryEntry *getDir() const { return Dir; }
bool operator<(const FileEntry &RHS) const {
return Device < RHS.Device || (Device == RHS.Device && Inode < RHS.Inode);
/// \brief 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> {
FileSystemOptions FileSystemOpts;
class UniqueDirContainer;
class UniqueFileContainer;
/// \brief Cache for existing real directories.
UniqueDirContainer &UniqueRealDirs;
/// \brief Cache for existing real files.
UniqueFileContainer &UniqueRealFiles;
/// \brief 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<DirectoryEntry*, 4> VirtualDirectoryEntries;
/// \brief The virtual files that we have allocated.
SmallVector<FileEntry*, 4> VirtualFileEntries;
/// \brief 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;
/// \brief A cache that maps paths to file entries (either real or
/// virtual) we have looked up.
/// \see SeenDirEntries
llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries;
/// \brief Each FileEntry we create is assigned a unique ID #.
unsigned NextFileUID;
// Statistics.
unsigned NumDirLookups, NumFileLookups;
unsigned NumDirCacheMisses, NumFileCacheMisses;
// Caching.
OwningPtr<FileSystemStatCache> StatCache;
bool getStatValue(const char *Path, struct stat &StatBuf,
int *FileDescriptor);
/// Add all ancestors of the given path (pointing to either a file
/// or a directory) as virtual directories.
void addAncestorsAsVirtualDirs(StringRef Path);
FileManager(const FileSystemOptions &FileSystemOpts);
/// \brief 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.
/// \param AtBeginning whether this new stat cache must be installed at the
/// beginning of the chain of stat caches. Otherwise, it will be added to
/// the end of the chain.
void addStatCache(FileSystemStatCache *statCache, bool AtBeginning = false);
/// \brief Removes the specified FileSystemStatCache object from the manager.
void removeStatCache(FileSystemStatCache *statCache);
/// \brief Removes all FileSystemStatCache objects from the manager.
void clearStatCaches();
/// \brief 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);
/// \brief 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);
/// \brief Returns the current file system options
const FileSystemOptions &getFileSystemOptions() { return FileSystemOpts; }
/// \brief 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);
/// \brief Open the specified file as a MemoryBuffer, returning a new
/// MemoryBuffer if successful, otherwise returning null.
llvm::MemoryBuffer *getBufferForFile(const FileEntry *Entry,
std::string *ErrorStr = 0,
bool isVolatile = false);
llvm::MemoryBuffer *getBufferForFile(StringRef Filename,
std::string *ErrorStr = 0);
/// \brief 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.
bool getNoncachedStatValue(StringRef Path, struct stat &StatBuf);
/// \brief Remove the real file \p Entry from the cache.
void invalidateCache(const FileEntry *Entry);
/// \brief If path is not absolute and FileSystemOptions set the working
/// directory, the path is modified to be relative to the given
/// working directory.
void FixupRelativePath(SmallVectorImpl<char> &path) const;
/// \brief Produce an array mapping from the unique IDs assigned to each
/// file to the corresponding FileEntry pointer.
void GetUniqueIDMapping(
SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
/// \brief 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);
void PrintStats() const;
} // end namespace clang