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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.
// This file defines the FileManager interface.
#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"
#include "llvm/Config/config.h" // for mode_t
// FIXME: Enhance libsystem to support inode and other fields in stat.
#include <sys/types.h>
#include <sys/stat.h>
namespace clang {
class FileManager;
/// DirectoryEntry - Cached information about one directory on the disk.
class DirectoryEntry {
const char *Name; // Name of the directory.
friend class FileManager;
DirectoryEntry() : Name(0) {}
const char *getName() const { return Name; }
/// FileEntry - Cached information about one file on the disk.
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'.
friend class FileManager;
FileEntry(dev_t device, ino_t inode, mode_t m)
: Name(0), Device(device), Inode(inode), FileMode(m) {}
// Add a default constructor for use with llvm::StringMap
FileEntry() : Name(0), Device(0), Inode(0), FileMode(0) {}
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; }
/// getDir - 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 Abstract interface for introducing a FileManager cache for 'stat'
/// system calls, which is used by precompiled and pretokenized headers to
/// improve performance.
class StatSysCallCache {
llvm::OwningPtr<StatSysCallCache> NextStatCache;
virtual ~StatSysCallCache() {}
virtual int stat(const char *path, struct stat *buf) {
if (getNextStatCache())
return getNextStatCache()->stat(path, buf);
return ::stat(path, buf);
/// \brief Sets the next stat call cache in the chain of stat caches.
/// Takes ownership of the given stat cache.
void setNextStatCache(StatSysCallCache *Cache) {
/// \brief Retrieve the next stat call cache in the chain.
StatSysCallCache *getNextStatCache() { return NextStatCache.get(); }
/// \brief Retrieve the next stat call cache in the chain, transferring
/// ownership of this cache (and, transitively, all of the remaining caches)
/// to the caller.
StatSysCallCache *takeNextStatCache() { return NextStatCache.take(); }
/// \brief A stat "cache" that can be used by FileManager to keep
/// track of the results of stat() calls that occur throughout the
/// execution of the front end.
class MemorizeStatCalls : public StatSysCallCache {
/// \brief The result of a stat() call.
/// The first member is the result of calling stat(). If stat()
/// found something, the second member is a copy of the stat
/// structure.
typedef std::pair<int, struct stat> StatResult;
/// \brief The set of stat() calls that have been
llvm::StringMap<StatResult, llvm::BumpPtrAllocator> StatCalls;
typedef llvm::StringMap<StatResult, llvm::BumpPtrAllocator>::const_iterator
iterator begin() const { return StatCalls.begin(); }
iterator end() const { return StatCalls.end(); }
virtual int stat(const char *path, struct stat *buf);
/// FileManager - 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 {
class UniqueDirContainer;
class UniqueFileContainer;
/// UniqueDirs/UniqueFiles - Cache for existing directories/files.
UniqueDirContainer &UniqueDirs;
UniqueFileContainer &UniqueFiles;
/// DirEntries/FileEntries - This is a cache of directory/file entries we have
/// looked up. The actual Entry is owned by UniqueFiles/UniqueDirs above.
llvm::StringMap<DirectoryEntry*, llvm::BumpPtrAllocator> DirEntries;
llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> FileEntries;
/// NextFileUID - Each FileEntry we create is assigned a unique ID #.
unsigned NextFileUID;
/// \brief The virtual files that we have allocated.
llvm::SmallVector<FileEntry *, 4> VirtualFileEntries;
// Statistics.
unsigned NumDirLookups, NumFileLookups;
unsigned NumDirCacheMisses, NumFileCacheMisses;
// Caching.
llvm::OwningPtr<StatSysCallCache> StatCache;
int stat_cached(const char* path, struct stat* buf) {
return StatCache.get() ? StatCache->stat(path, buf) : stat(path, buf);
/// \brief Installs the provided StatSysCallCache 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(StatSysCallCache *statCache, bool AtBeginning = false);
/// \brief Removes the provided StatSysCallCache object from the file manager.
void removeStatCache(StatSysCallCache *statCache);
/// getDirectory - Lookup, cache, and verify the specified directory. This
/// returns null if the directory doesn't exist.
const DirectoryEntry *getDirectory(const llvm::StringRef &Filename) {
return getDirectory(Filename.begin(), Filename.end());
const DirectoryEntry *getDirectory(const char *FileStart,const char *FileEnd);
/// getFile - Lookup, cache, and verify the specified file. This returns null
/// if the file doesn't exist.
const FileEntry *getFile(const llvm::StringRef &Filename) {
return getFile(Filename.begin(), Filename.end());
const FileEntry *getFile(const char *FilenameStart,
const char *FilenameEnd);
/// \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(const llvm::StringRef &Filename,
off_t Size, time_t ModificationTime);
void PrintStats() const;
} // end namespace clang