1 //===--- FileManager.h - File System Probing and Caching --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// \brief Defines the clang::FileManager interface and associated types.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_FILEMANAGER_H
16 #define LLVM_CLANG_FILEMANAGER_H
18 #include "clang/Basic/FileSystemOptions.h"
19 #include "clang/Basic/LLVM.h"
20 #include "llvm/ADT/IntrusiveRefCntPtr.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/StringMap.h"
23 #include "llvm/ADT/StringRef.h"
24 #include "llvm/ADT/OwningPtr.h"
25 #include "llvm/Support/Allocator.h"
26 // FIXME: Enhance libsystem to support inode and other fields in stat.
27 #include <sys/types.h>
30 typedef unsigned short mode_t;
37 namespace sys { class Path; }
42 class FileSystemStatCache;
44 /// \brief Cached information about one directory (either on disk or in
45 /// the virtual file system).
46 class DirectoryEntry {
47 const char *Name; // Name of the directory.
48 friend class FileManager;
50 DirectoryEntry() : Name(0) {}
51 const char *getName() const { return Name; }
54 /// \brief Cached information about one file (either on disk
55 /// or in the virtual file system).
57 /// If the 'FD' member is valid, then this FileEntry has an open file
58 /// descriptor for the file.
60 const char *Name; // Name of the file.
61 off_t Size; // File size in bytes.
62 time_t ModTime; // Modification time of file.
63 const DirectoryEntry *Dir; // Directory file lives in.
64 unsigned UID; // A unique (small) ID for the file.
65 dev_t Device; // ID for the device containing the file.
66 ino_t Inode; // Inode number for the file.
67 mode_t FileMode; // The file mode as returned by 'stat'.
69 /// FD - The file descriptor for the file entry if it is opened and owned
70 /// by the FileEntry. If not, this is set to -1.
72 friend class FileManager;
75 FileEntry(dev_t device, ino_t inode, mode_t m)
76 : Name(0), Device(device), Inode(inode), FileMode(m), FD(-1) {}
77 // Add a default constructor for use with llvm::StringMap
78 FileEntry() : Name(0), Device(0), Inode(0), FileMode(0), FD(-1) {}
80 FileEntry(const FileEntry &FE) {
81 memcpy(this, &FE, sizeof(FE));
82 assert(FD == -1 && "Cannot copy a file-owning FileEntry");
85 void operator=(const FileEntry &FE) {
86 memcpy(this, &FE, sizeof(FE));
87 assert(FD == -1 && "Cannot assign a file-owning FileEntry");
92 const char *getName() const { return Name; }
93 off_t getSize() const { return Size; }
94 unsigned getUID() const { return UID; }
95 ino_t getInode() const { return Inode; }
96 dev_t getDevice() const { return Device; }
97 time_t getModificationTime() const { return ModTime; }
98 mode_t getFileMode() const { return FileMode; }
100 /// \brief Return the directory the file lives in.
101 const DirectoryEntry *getDir() const { return Dir; }
103 bool operator<(const FileEntry &RHS) const {
104 return Device < RHS.Device || (Device == RHS.Device && Inode < RHS.Inode);
108 /// \brief Implements support for file system lookup, file system caching,
109 /// and directory search management.
111 /// This also handles more advanced properties, such as uniquing files based
112 /// on "inode", so that a file with two names (e.g. symlinked) will be treated
113 /// as a single file.
115 class FileManager : public RefCountedBase<FileManager> {
116 FileSystemOptions FileSystemOpts;
118 class UniqueDirContainer;
119 class UniqueFileContainer;
121 /// \brief Cache for existing real directories.
122 UniqueDirContainer &UniqueRealDirs;
124 /// \brief Cache for existing real files.
125 UniqueFileContainer &UniqueRealFiles;
127 /// \brief The virtual directories that we have allocated.
129 /// For each virtual file (e.g. foo/bar/baz.cpp), we add all of its parent
130 /// directories (foo/ and foo/bar/) here.
131 SmallVector<DirectoryEntry*, 4> VirtualDirectoryEntries;
132 /// \brief The virtual files that we have allocated.
133 SmallVector<FileEntry*, 4> VirtualFileEntries;
135 /// \brief A cache that maps paths to directory entries (either real or
136 /// virtual) we have looked up
138 /// The actual Entries for real directories/files are
139 /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries
140 /// for virtual directories/files are owned by
141 /// VirtualDirectoryEntries/VirtualFileEntries above.
143 llvm::StringMap<DirectoryEntry*, llvm::BumpPtrAllocator> SeenDirEntries;
145 /// \brief A cache that maps paths to file entries (either real or
146 /// virtual) we have looked up.
148 /// \see SeenDirEntries
149 llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries;
151 /// \brief Each FileEntry we create is assigned a unique ID #.
153 unsigned NextFileUID;
156 unsigned NumDirLookups, NumFileLookups;
157 unsigned NumDirCacheMisses, NumFileCacheMisses;
160 OwningPtr<FileSystemStatCache> StatCache;
162 bool getStatValue(const char *Path, struct stat &StatBuf,
163 int *FileDescriptor);
165 /// Add all ancestors of the given path (pointing to either a file
166 /// or a directory) as virtual directories.
167 void addAncestorsAsVirtualDirs(StringRef Path);
170 FileManager(const FileSystemOptions &FileSystemOpts);
173 /// \brief Installs the provided FileSystemStatCache object within
176 /// Ownership of this object is transferred to the FileManager.
178 /// \param statCache the new stat cache to install. Ownership of this
179 /// object is transferred to the FileManager.
181 /// \param AtBeginning whether this new stat cache must be installed at the
182 /// beginning of the chain of stat caches. Otherwise, it will be added to
183 /// the end of the chain.
184 void addStatCache(FileSystemStatCache *statCache, bool AtBeginning = false);
186 /// \brief Removes the specified FileSystemStatCache object from the manager.
187 void removeStatCache(FileSystemStatCache *statCache);
189 /// \brief Removes all FileSystemStatCache objects from the manager.
190 void clearStatCaches();
192 /// \brief Lookup, cache, and verify the specified directory (real or
195 /// This returns NULL if the directory doesn't exist.
197 /// \param CacheFailure If true and the file does not exist, we'll cache
198 /// the failure to find this file.
199 const DirectoryEntry *getDirectory(StringRef DirName,
200 bool CacheFailure = true);
202 /// \brief Lookup, cache, and verify the specified file (real or
205 /// This returns NULL if the file doesn't exist.
207 /// \param OpenFile if true and the file exists, it will be opened.
209 /// \param CacheFailure If true and the file does not exist, we'll cache
210 /// the failure to find this file.
211 const FileEntry *getFile(StringRef Filename, bool OpenFile = false,
212 bool CacheFailure = true);
214 /// \brief Returns the current file system options
215 const FileSystemOptions &getFileSystemOptions() { return FileSystemOpts; }
217 /// \brief Retrieve a file entry for a "virtual" file that acts as
218 /// if there were a file with the given name on disk.
220 /// The file itself is not accessed.
221 const FileEntry *getVirtualFile(StringRef Filename, off_t Size,
222 time_t ModificationTime);
224 /// \brief Open the specified file as a MemoryBuffer, returning a new
225 /// MemoryBuffer if successful, otherwise returning null.
226 llvm::MemoryBuffer *getBufferForFile(const FileEntry *Entry,
227 std::string *ErrorStr = 0,
228 bool isVolatile = false);
229 llvm::MemoryBuffer *getBufferForFile(StringRef Filename,
230 std::string *ErrorStr = 0);
232 /// \brief Get the 'stat' information for the given \p Path.
234 /// If the path is relative, it will be resolved against the WorkingDir of the
235 /// FileManager's FileSystemOptions.
236 bool getNoncachedStatValue(StringRef Path, struct stat &StatBuf);
238 /// \brief Remove the real file \p Entry from the cache.
239 void invalidateCache(const FileEntry *Entry);
241 /// \brief If path is not absolute and FileSystemOptions set the working
242 /// directory, the path is modified to be relative to the given
243 /// working directory.
244 void FixupRelativePath(SmallVectorImpl<char> &path) const;
246 /// \brief Produce an array mapping from the unique IDs assigned to each
247 /// file to the corresponding FileEntry pointer.
248 void GetUniqueIDMapping(
249 SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
251 /// \brief Modifies the size and modification time of a previously created
252 /// FileEntry. Use with caution.
253 static void modifyFileEntry(FileEntry *File, off_t Size,
254 time_t ModificationTime);
256 void PrintStats() const;
259 } // end namespace clang