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 //===----------------------------------------------------------------------===//
10 // This file defines the FileManager interface.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_FILEMANAGER_H
15 #define LLVM_CLANG_FILEMANAGER_H
17 #include "clang/Basic/FileSystemOptions.h"
18 #include "llvm/ADT/IntrusiveRefCntPtr.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/ADT/OwningPtr.h"
23 #include "llvm/Support/Allocator.h"
24 #include "llvm/Config/config.h" // for mode_t
25 // FIXME: Enhance libsystem to support inode and other fields in stat.
26 #include <sys/types.h>
32 namespace sys { class Path; }
37 class FileSystemStatCache;
39 /// DirectoryEntry - Cached information about one directory (either on
40 /// the disk or in the virtual file system).
42 class DirectoryEntry {
43 const char *Name; // Name of the directory.
44 friend class FileManager;
46 DirectoryEntry() : Name(0) {}
47 const char *getName() const { return Name; }
50 /// FileEntry - Cached information about one file (either on the disk
51 /// or in the virtual file system). If the 'FD' member is valid, then
52 /// this FileEntry has an open file descriptor for the file.
55 const char *Name; // Name of the file.
56 off_t Size; // File size in bytes.
57 time_t ModTime; // Modification time of file.
58 const DirectoryEntry *Dir; // Directory file lives in.
59 unsigned UID; // A unique (small) ID for the file.
60 dev_t Device; // ID for the device containing the file.
61 ino_t Inode; // Inode number for the file.
62 mode_t FileMode; // The file mode as returned by 'stat'.
64 /// FD - The file descriptor for the file entry if it is opened and owned
65 /// by the FileEntry. If not, this is set to -1.
67 friend class FileManager;
70 FileEntry(dev_t device, ino_t inode, mode_t m)
71 : Name(0), Device(device), Inode(inode), FileMode(m), FD(-1) {}
72 // Add a default constructor for use with llvm::StringMap
73 FileEntry() : Name(0), Device(0), Inode(0), FileMode(0), FD(-1) {}
75 FileEntry(const FileEntry &FE) {
76 memcpy(this, &FE, sizeof(FE));
77 assert(FD == -1 && "Cannot copy a file-owning FileEntry");
80 void operator=(const FileEntry &FE) {
81 memcpy(this, &FE, sizeof(FE));
82 assert(FD == -1 && "Cannot assign a file-owning FileEntry");
87 const char *getName() const { return Name; }
88 off_t getSize() const { return Size; }
89 unsigned getUID() const { return UID; }
90 ino_t getInode() const { return Inode; }
91 dev_t getDevice() const { return Device; }
92 time_t getModificationTime() const { return ModTime; }
93 mode_t getFileMode() const { return FileMode; }
95 /// getDir - Return the directory the file lives in.
97 const DirectoryEntry *getDir() const { return Dir; }
99 bool operator<(const FileEntry &RHS) const {
100 return Device < RHS.Device || (Device == RHS.Device && Inode < RHS.Inode);
104 /// FileManager - Implements support for file system lookup, file system
105 /// caching, and directory search management. This also handles more advanced
106 /// properties, such as uniquing files based on "inode", so that a file with two
107 /// names (e.g. symlinked) will be treated as a single file.
109 class FileManager : public llvm::RefCountedBase<FileManager> {
110 FileSystemOptions FileSystemOpts;
112 class UniqueDirContainer;
113 class UniqueFileContainer;
115 /// UniqueRealDirs/UniqueRealFiles - Cache for existing real directories/files.
117 UniqueDirContainer &UniqueRealDirs;
118 UniqueFileContainer &UniqueRealFiles;
120 /// \brief The virtual directories that we have allocated. For each
121 /// virtual file (e.g. foo/bar/baz.cpp), we add all of its parent
122 /// directories (foo/ and foo/bar/) here.
123 llvm::SmallVector<DirectoryEntry*, 4> VirtualDirectoryEntries;
124 /// \brief The virtual files that we have allocated.
125 llvm::SmallVector<FileEntry*, 4> VirtualFileEntries;
127 /// SeenDirEntries/SeenFileEntries - This is a cache that maps paths
128 /// to directory/file entries (either real or virtual) we have
129 /// looked up. The actual Entries for real directories/files are
130 /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries
131 /// for virtual directories/files are owned by
132 /// VirtualDirectoryEntries/VirtualFileEntries above.
134 llvm::StringMap<DirectoryEntry*, llvm::BumpPtrAllocator> SeenDirEntries;
135 llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries;
137 /// NextFileUID - Each FileEntry we create is assigned a unique ID #.
139 unsigned NextFileUID;
142 unsigned NumDirLookups, NumFileLookups;
143 unsigned NumDirCacheMisses, NumFileCacheMisses;
146 llvm::OwningPtr<FileSystemStatCache> StatCache;
148 bool getStatValue(const char *Path, struct stat &StatBuf,
149 int *FileDescriptor);
151 /// Add all ancestors of the given path (pointing to either a file
152 /// or a directory) as virtual directories.
153 void addAncestorsAsVirtualDirs(llvm::StringRef Path);
156 FileManager(const FileSystemOptions &FileSystemOpts);
159 /// \brief Installs the provided FileSystemStatCache object within
162 /// Ownership of this object is transferred to the FileManager.
164 /// \param statCache the new stat cache to install. Ownership of this
165 /// object is transferred to the FileManager.
167 /// \param AtBeginning whether this new stat cache must be installed at the
168 /// beginning of the chain of stat caches. Otherwise, it will be added to
169 /// the end of the chain.
170 void addStatCache(FileSystemStatCache *statCache, bool AtBeginning = false);
172 /// \brief Removes the specified FileSystemStatCache object from the manager.
173 void removeStatCache(FileSystemStatCache *statCache);
175 /// getDirectory - Lookup, cache, and verify the specified directory
176 /// (real or virtual). This returns NULL if the directory doesn't exist.
178 const DirectoryEntry *getDirectory(llvm::StringRef DirName);
180 /// \brief Lookup, cache, and verify the specified file (real or
181 /// virtual). This returns NULL if the file doesn't exist.
183 /// \param openFile if true and the file exists, it will be opened.
184 const FileEntry *getFile(llvm::StringRef Filename, bool openFile = false);
186 /// \brief Retrieve a file entry for a "virtual" file that acts as
187 /// if there were a file with the given name on disk. The file
188 /// itself is not accessed.
189 const FileEntry *getVirtualFile(llvm::StringRef Filename, off_t Size,
190 time_t ModificationTime);
192 /// \brief Open the specified file as a MemoryBuffer, returning a new
193 /// MemoryBuffer if successful, otherwise returning null.
194 llvm::MemoryBuffer *getBufferForFile(const FileEntry *Entry,
195 std::string *ErrorStr = 0);
196 llvm::MemoryBuffer *getBufferForFile(llvm::StringRef Filename,
197 std::string *ErrorStr = 0);
199 // getNoncachedStatValue - Will get the 'stat' information for the given path.
200 // If the path is relative, it will be resolved against the WorkingDir of the
201 // FileManager's FileSystemOptions.
202 bool getNoncachedStatValue(llvm::StringRef Path, struct stat &StatBuf);
204 /// \brief If path is not absolute and FileSystemOptions set the working
205 /// directory, the path is modified to be relative to the given
206 /// working directory.
207 void FixupRelativePath(llvm::SmallVectorImpl<char> &path) const;
209 /// \brief Produce an array mapping from the unique IDs assigned to each
210 /// file to the corresponding FileEntry pointer.
211 void GetUniqueIDMapping(
212 llvm::SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
214 void PrintStats() const;
217 } // end namespace clang