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1//===--- FileManager.h - File System Probing and Caching --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \file
11/// Defines the clang::FileManager interface and associated types.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_BASIC_FILEMANAGER_H
16#define LLVM_CLANG_BASIC_FILEMANAGER_H
17
18#include "clang/Basic/FileSystemOptions.h"
19#include "clang/Basic/VirtualFileSystem.h"
20#include "llvm/ADT/DenseMap.h"
21#include "llvm/ADT/IntrusiveRefCntPtr.h"
22#include "llvm/ADT/SmallVector.h"
23#include "llvm/ADT/StringMap.h"
24#include "llvm/ADT/StringRef.h"
25#include "llvm/Support/Allocator.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/FileSystem.h"
28#include <ctime>
29#include <memory>
30#include <map>
31#include <string>
32
33namespace llvm {
34
35class MemoryBuffer;
36
37} // end namespace llvm
38
39namespace clang {
40
41class FileSystemStatCache;
42
43/// Cached information about one directory (either on disk or in
44/// the virtual file system).
45class DirectoryEntry {
46 friend class FileManager;
47
48 StringRef Name; // Name of the directory.
49
50public:
51 StringRef getName() const { return Name; }
52};
53
54/// Cached information about one file (either on disk
55/// or in the virtual file system).
56///
57/// If the 'File' member is valid, then this FileEntry has an open file
58/// descriptor for the file.
59class FileEntry {
60 friend class FileManager;
61
62 StringRef Name; // Name of the file.
63 std::string RealPathName; // Real path to the file; could be empty.
64 off_t Size; // File size in bytes.
65 time_t ModTime; // Modification time of file.
66 const DirectoryEntry *Dir; // Directory file lives in.
67 unsigned UID; // A unique (small) ID for the file.
68 llvm::sys::fs::UniqueID UniqueID;
69 bool IsNamedPipe;
70 bool InPCH;
71 bool IsValid; // Is this \c FileEntry initialized and valid?
72
73 /// The open file, if it is owned by the \p FileEntry.
74 mutable std::unique_ptr<vfs::File> File;
75
76public:
77 FileEntry()
78 : UniqueID(0, 0), IsNamedPipe(false), InPCH(false), IsValid(false)
79 {}
80
81 FileEntry(const FileEntry &) = delete;
82 FileEntry &operator=(const FileEntry &) = delete;
83
84 StringRef getName() const { return Name; }
85 StringRef tryGetRealPathName() const { return RealPathName; }
86 bool isValid() const { return IsValid; }
87 off_t getSize() const { return Size; }
88 unsigned getUID() const { return UID; }
89 const llvm::sys::fs::UniqueID &getUniqueID() const { return UniqueID; }
90 bool isInPCH() const { return InPCH; }
91 time_t getModificationTime() const { return ModTime; }
92
93 /// Return the directory the file lives in.
94 const DirectoryEntry *getDir() const { return Dir; }
95
96 bool operator<(const FileEntry &RHS) const { return UniqueID < RHS.UniqueID; }
97
98 /// Check whether the file is a named pipe (and thus can't be opened by
99 /// the native FileManager methods).
100 bool isNamedPipe() const { return IsNamedPipe; }
101
102 void closeFile() const {
103 File.reset(); // rely on destructor to close File
104 }
105};
106
107struct FileData;
108
109/// Implements support for file system lookup, file system caching,
110/// and directory search management.
111///
112/// This also handles more advanced properties, such as uniquing files based
113/// on "inode", so that a file with two names (e.g. symlinked) will be treated
114/// as a single file.
115///
116class FileManager : public RefCountedBase<FileManager> {
117 IntrusiveRefCntPtr<vfs::FileSystem> FS;
118 FileSystemOptions FileSystemOpts;
119
120 /// Cache for existing real directories.
121 std::map<llvm::sys::fs::UniqueID, DirectoryEntry> UniqueRealDirs;
122
123 /// Cache for existing real files.
124 std::map<llvm::sys::fs::UniqueID, FileEntry> UniqueRealFiles;
125
126 /// The virtual directories that we have allocated.
127 ///
128 /// For each virtual file (e.g. foo/bar/baz.cpp), we add all of its parent
129 /// directories (foo/ and foo/bar/) here.
130 SmallVector<std::unique_ptr<DirectoryEntry>, 4> VirtualDirectoryEntries;
131 /// The virtual files that we have allocated.
132 SmallVector<std::unique_ptr<FileEntry>, 4> VirtualFileEntries;
133
134 /// A cache that maps paths to directory entries (either real or
135 /// virtual) we have looked up
136 ///
137 /// The actual Entries for real directories/files are
138 /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries
139 /// for virtual directories/files are owned by
140 /// VirtualDirectoryEntries/VirtualFileEntries above.
141 ///
142 llvm::StringMap<DirectoryEntry*, llvm::BumpPtrAllocator> SeenDirEntries;
143
144 /// A cache that maps paths to file entries (either real or
145 /// virtual) we have looked up.
146 ///
147 /// \see SeenDirEntries
148 llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries;
149
150 /// The canonical names of directories.
151 llvm::DenseMap<const DirectoryEntry *, llvm::StringRef> CanonicalDirNames;
152
153 /// Storage for canonical names that we have computed.
154 llvm::BumpPtrAllocator CanonicalNameStorage;
155
156 /// Each FileEntry we create is assigned a unique ID #.
157 ///
158 unsigned NextFileUID;
159
160 // Statistics.
161 unsigned NumDirLookups, NumFileLookups;
162 unsigned NumDirCacheMisses, NumFileCacheMisses;
163
164 // Caching.
165 std::unique_ptr<FileSystemStatCache> StatCache;
166
167 bool getStatValue(StringRef Path, FileData &Data, bool isFile,
168 std::unique_ptr<vfs::File> *F);
169
170 /// Add all ancestors of the given path (pointing to either a file
171 /// or a directory) as virtual directories.
172 void addAncestorsAsVirtualDirs(StringRef Path);
173
174public:
175 FileManager(const FileSystemOptions &FileSystemOpts,
176 IntrusiveRefCntPtr<vfs::FileSystem> FS = nullptr);
177 ~FileManager();
178
179 /// Installs the provided FileSystemStatCache object within
180 /// the FileManager.
181 ///
182 /// Ownership of this object is transferred to the FileManager.
183 ///
184 /// \param statCache the new stat cache to install. Ownership of this
185 /// object is transferred to the FileManager.
186 ///
187 /// \param AtBeginning whether this new stat cache must be installed at the
188 /// beginning of the chain of stat caches. Otherwise, it will be added to
189 /// the end of the chain.
190 void addStatCache(std::unique_ptr<FileSystemStatCache> statCache,
191 bool AtBeginning = false);
192
193 /// Removes the specified FileSystemStatCache object from the manager.
194 void removeStatCache(FileSystemStatCache *statCache);
195
196 /// Removes all FileSystemStatCache objects from the manager.
197 void clearStatCaches();
198
199 /// Lookup, cache, and verify the specified directory (real or
200 /// virtual).
201 ///
202 /// This returns NULL if the directory doesn't exist.
203 ///
204 /// \param CacheFailure If true and the file does not exist, we'll cache
205 /// the failure to find this file.
206 const DirectoryEntry *getDirectory(StringRef DirName,
207 bool CacheFailure = true);
208
209 /// Lookup, cache, and verify the specified file (real or
210 /// virtual).
211 ///
212 /// This returns NULL if the file doesn't exist.
213 ///
214 /// \param OpenFile if true and the file exists, it will be opened.
215 ///
216 /// \param CacheFailure If true and the file does not exist, we'll cache
217 /// the failure to find this file.
218 const FileEntry *getFile(StringRef Filename, bool OpenFile = false,
219 bool CacheFailure = true);
220
221 /// Returns the current file system options
222 FileSystemOptions &getFileSystemOpts() { return FileSystemOpts; }
223 const FileSystemOptions &getFileSystemOpts() const { return FileSystemOpts; }
224
225 IntrusiveRefCntPtr<vfs::FileSystem> getVirtualFileSystem() const {
226 return FS;
227 }
228
229 /// Retrieve a file entry for a "virtual" file that acts as
230 /// if there were a file with the given name on disk.
231 ///
232 /// The file itself is not accessed.
233 const FileEntry *getVirtualFile(StringRef Filename, off_t Size,
234 time_t ModificationTime);
235
236 /// Open the specified file as a MemoryBuffer, returning a new
237 /// MemoryBuffer if successful, otherwise returning null.
238 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
239 getBufferForFile(const FileEntry *Entry, bool isVolatile = false,
240 bool ShouldCloseOpenFile = true);
241 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
242 getBufferForFile(StringRef Filename, bool isVolatile = false);
243
244 /// Get the 'stat' information for the given \p Path.
245 ///
246 /// If the path is relative, it will be resolved against the WorkingDir of the
247 /// FileManager's FileSystemOptions.
248 ///
249 /// \returns false on success, true on error.
250 bool getNoncachedStatValue(StringRef Path,
251 vfs::Status &Result);
252
253 /// Remove the real file \p Entry from the cache.
254 void invalidateCache(const FileEntry *Entry);
255
256 /// If path is not absolute and FileSystemOptions set the working
257 /// directory, the path is modified to be relative to the given
258 /// working directory.
259 /// \returns true if \c path changed.
260 bool FixupRelativePath(SmallVectorImpl<char> &path) const;
261
262 /// Makes \c Path absolute taking into account FileSystemOptions and the
263 /// working directory option.
264 /// \returns true if \c Path changed to absolute.
265 bool makeAbsolutePath(SmallVectorImpl<char> &Path) const;
266
267 /// Produce an array mapping from the unique IDs assigned to each
268 /// file to the corresponding FileEntry pointer.
269 void GetUniqueIDMapping(
270 SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
271
272 /// Modifies the size and modification time of a previously created
273 /// FileEntry. Use with caution.
274 static void modifyFileEntry(FileEntry *File, off_t Size,
275 time_t ModificationTime);
276
277 /// Retrieve the canonical name for a given directory.
278 ///
279 /// This is a very expensive operation, despite its results being cached,
280 /// and should only be used when the physical layout of the file system is
281 /// required, which is (almost) never.
282 StringRef getCanonicalName(const DirectoryEntry *Dir);
283
284 void PrintStats() const;
285};
286
287} // end namespace clang
288
289#endif // LLVM_CLANG_BASIC_FILEMANAGER_H
290

Warning: That file was not part of the compilation database. It may have many parsing errors.