Coverage Report

Created: 2022-07-16 07:03

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/Basic/FileManager.h
Line
Count
Source (jump to first uncovered line)
1
//===--- FileManager.h - File System Probing and Caching --------*- C++ -*-===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
///
9
/// \file
10
/// Defines the clang::FileManager interface and associated types.
11
///
12
//===----------------------------------------------------------------------===//
13
14
#ifndef LLVM_CLANG_BASIC_FILEMANAGER_H
15
#define LLVM_CLANG_BASIC_FILEMANAGER_H
16
17
#include "clang/Basic/DirectoryEntry.h"
18
#include "clang/Basic/FileEntry.h"
19
#include "clang/Basic/FileSystemOptions.h"
20
#include "clang/Basic/LLVM.h"
21
#include "llvm/ADT/DenseMap.h"
22
#include "llvm/ADT/IntrusiveRefCntPtr.h"
23
#include "llvm/ADT/PointerUnion.h"
24
#include "llvm/ADT/SmallVector.h"
25
#include "llvm/ADT/StringMap.h"
26
#include "llvm/ADT/StringRef.h"
27
#include "llvm/Support/Allocator.h"
28
#include "llvm/Support/ErrorOr.h"
29
#include "llvm/Support/FileSystem.h"
30
#include "llvm/Support/VirtualFileSystem.h"
31
#include <ctime>
32
#include <map>
33
#include <memory>
34
#include <string>
35
36
namespace llvm {
37
38
class MemoryBuffer;
39
40
} // end namespace llvm
41
42
namespace clang {
43
44
class FileSystemStatCache;
45
46
/// Implements support for file system lookup, file system caching,
47
/// and directory search management.
48
///
49
/// This also handles more advanced properties, such as uniquing files based
50
/// on "inode", so that a file with two names (e.g. symlinked) will be treated
51
/// as a single file.
52
///
53
class FileManager : public RefCountedBase<FileManager> {
54
  IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
55
  FileSystemOptions FileSystemOpts;
56
  llvm::SpecificBumpPtrAllocator<FileEntry> FilesAlloc;
57
  llvm::SpecificBumpPtrAllocator<DirectoryEntry> DirsAlloc;
58
59
  /// Cache for existing real directories.
60
  llvm::DenseMap<llvm::sys::fs::UniqueID, DirectoryEntry *> UniqueRealDirs;
61
62
  /// Cache for existing real files.
63
  llvm::DenseMap<llvm::sys::fs::UniqueID, FileEntry *> UniqueRealFiles;
64
65
  /// The virtual directories that we have allocated.
66
  ///
67
  /// For each virtual file (e.g. foo/bar/baz.cpp), we add all of its parent
68
  /// directories (foo/ and foo/bar/) here.
69
  SmallVector<DirectoryEntry *, 4> VirtualDirectoryEntries;
70
  /// The virtual files that we have allocated.
71
  SmallVector<FileEntry *, 4> VirtualFileEntries;
72
73
  /// A set of files that bypass the maps and uniquing.  They can have
74
  /// conflicting filenames.
75
  SmallVector<FileEntry *, 0> BypassFileEntries;
76
77
  /// A cache that maps paths to directory entries (either real or
78
  /// virtual) we have looked up, or an error that occurred when we looked up
79
  /// the directory.
80
  ///
81
  /// The actual Entries for real directories/files are
82
  /// owned by UniqueRealDirs/UniqueRealFiles above, while the Entries
83
  /// for virtual directories/files are owned by
84
  /// VirtualDirectoryEntries/VirtualFileEntries above.
85
  ///
86
  llvm::StringMap<llvm::ErrorOr<DirectoryEntry &>, llvm::BumpPtrAllocator>
87
  SeenDirEntries;
88
89
  /// A cache that maps paths to file entries (either real or
90
  /// virtual) we have looked up, or an error that occurred when we looked up
91
  /// the file.
92
  ///
93
  /// \see SeenDirEntries
94
  llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>, llvm::BumpPtrAllocator>
95
      SeenFileEntries;
96
97
  /// A mirror of SeenFileEntries to give fake answers for getBypassFile().
98
  ///
99
  /// Don't bother hooking up a BumpPtrAllocator. This should be rarely used,
100
  /// and only on error paths.
101
  std::unique_ptr<llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>>>
102
      SeenBypassFileEntries;
103
104
  /// The file entry for stdin, if it has been accessed through the FileManager.
105
  Optional<FileEntryRef> STDIN;
106
107
  /// The canonical names of files and directories .
108
  llvm::DenseMap<const void *, llvm::StringRef> CanonicalNames;
109
110
  /// Storage for canonical names that we have computed.
111
  llvm::BumpPtrAllocator CanonicalNameStorage;
112
113
  /// Each FileEntry we create is assigned a unique ID #.
114
  ///
115
  unsigned NextFileUID;
116
117
  // Caching.
118
  std::unique_ptr<FileSystemStatCache> StatCache;
119
120
  std::error_code getStatValue(StringRef Path, llvm::vfs::Status &Status,
121
                               bool isFile,
122
                               std::unique_ptr<llvm::vfs::File> *F);
123
124
  /// Add all ancestors of the given path (pointing to either a file
125
  /// or a directory) as virtual directories.
126
  void addAncestorsAsVirtualDirs(StringRef Path);
127
128
  /// Fills the RealPathName in file entry.
129
  void fillRealPathName(FileEntry *UFE, llvm::StringRef FileName);
130
131
public:
132
  /// Construct a file manager, optionally with a custom VFS.
133
  ///
134
  /// \param FS if non-null, the VFS to use.  Otherwise uses
135
  /// llvm::vfs::getRealFileSystem().
136
  FileManager(const FileSystemOptions &FileSystemOpts,
137
              IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
138
  ~FileManager();
139
140
  /// Installs the provided FileSystemStatCache object within
141
  /// the FileManager.
142
  ///
143
  /// Ownership of this object is transferred to the FileManager.
144
  ///
145
  /// \param statCache the new stat cache to install. Ownership of this
146
  /// object is transferred to the FileManager.
147
  void setStatCache(std::unique_ptr<FileSystemStatCache> statCache);
148
149
  /// Removes the FileSystemStatCache object from the manager.
150
  void clearStatCache();
151
152
  /// Returns the number of unique real file entries cached by the file manager.
153
  size_t getNumUniqueRealFiles() const { return UniqueRealFiles.size(); }
154
155
  /// Lookup, cache, and verify the specified directory (real or
156
  /// virtual).
157
  ///
158
  /// This returns a \c std::error_code if there was an error reading the
159
  /// directory. On success, returns the reference to the directory entry
160
  /// together with the exact path that was used to access a file by a
161
  /// particular call to getDirectoryRef.
162
  ///
163
  /// \param CacheFailure If true and the file does not exist, we'll cache
164
  /// the failure to find this file.
165
  llvm::Expected<DirectoryEntryRef> getDirectoryRef(StringRef DirName,
166
                                                    bool CacheFailure = true);
167
168
  /// Get a \c DirectoryEntryRef if it exists, without doing anything on error.
169
  llvm::Optional<DirectoryEntryRef>
170
6.87M
  getOptionalDirectoryRef(StringRef DirName, bool CacheFailure = true) {
171
6.87M
    return llvm::expectedToOptional(getDirectoryRef(DirName, CacheFailure));
172
6.87M
  }
173
174
  /// Lookup, cache, and verify the specified directory (real or
175
  /// virtual).
176
  ///
177
  /// This function is deprecated and will be removed at some point in the
178
  /// future, new clients should use
179
  ///  \c getDirectoryRef.
180
  ///
181
  /// This returns a \c std::error_code if there was an error reading the
182
  /// directory. If there is no error, the DirectoryEntry is guaranteed to be
183
  /// non-NULL.
184
  ///
185
  /// \param CacheFailure If true and the file does not exist, we'll cache
186
  /// the failure to find this file.
187
  llvm::ErrorOr<const DirectoryEntry *>
188
  getDirectory(StringRef DirName, bool CacheFailure = true);
189
190
  /// Lookup, cache, and verify the specified file (real or
191
  /// virtual).
192
  ///
193
  /// This function is deprecated and will be removed at some point in the
194
  /// future, new clients should use
195
  ///  \c getFileRef.
196
  ///
197
  /// This returns a \c std::error_code if there was an error loading the file.
198
  /// If there is no error, the FileEntry is guaranteed to be non-NULL.
199
  ///
200
  /// \param OpenFile if true and the file exists, it will be opened.
201
  ///
202
  /// \param CacheFailure If true and the file does not exist, we'll cache
203
  /// the failure to find this file.
204
  llvm::ErrorOr<const FileEntry *>
205
  getFile(StringRef Filename, bool OpenFile = false, bool CacheFailure = true);
206
207
  /// Lookup, cache, and verify the specified file (real or virtual). Return the
208
  /// reference to the file entry together with the exact path that was used to
209
  /// access a file by a particular call to getFileRef. If the underlying VFS is
210
  /// a redirecting VFS that uses external file names, the returned FileEntryRef
211
  /// will use the external name instead of the filename that was passed to this
212
  /// method.
213
  ///
214
  /// This returns a \c std::error_code if there was an error loading the file,
215
  /// or a \c FileEntryRef otherwise.
216
  ///
217
  /// \param OpenFile if true and the file exists, it will be opened.
218
  ///
219
  /// \param CacheFailure If true and the file does not exist, we'll cache
220
  /// the failure to find this file.
221
  llvm::Expected<FileEntryRef> getFileRef(StringRef Filename,
222
                                          bool OpenFile = false,
223
                                          bool CacheFailure = true);
224
225
  /// Get the FileEntryRef for stdin, returning an error if stdin cannot be
226
  /// read.
227
  ///
228
  /// This reads and caches stdin before returning. Subsequent calls return the
229
  /// same file entry, and a reference to the cached input is returned by calls
230
  /// to getBufferForFile.
231
  llvm::Expected<FileEntryRef> getSTDIN();
232
233
  /// Get a FileEntryRef if it exists, without doing anything on error.
234
  llvm::Optional<FileEntryRef> getOptionalFileRef(StringRef Filename,
235
                                                  bool OpenFile = false,
236
427k
                                                  bool CacheFailure = true) {
237
427k
    return llvm::expectedToOptional(
238
427k
        getFileRef(Filename, OpenFile, CacheFailure));
239
427k
  }
240
241
  /// Returns the current file system options
242
38.4k
  FileSystemOptions &getFileSystemOpts() { return FileSystemOpts; }
243
0
  const FileSystemOptions &getFileSystemOpts() const { return FileSystemOpts; }
244
245
568k
  llvm::vfs::FileSystem &getVirtualFileSystem() const { return *FS; }
246
247
338
  void setVirtualFileSystem(IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS) {
248
338
    this->FS = std::move(FS);
249
338
  }
250
251
  /// Retrieve a file entry for a "virtual" file that acts as
252
  /// if there were a file with the given name on disk.
253
  ///
254
  /// The file itself is not accessed.
255
  FileEntryRef getVirtualFileRef(StringRef Filename, off_t Size,
256
                                 time_t ModificationTime);
257
258
  const FileEntry *getVirtualFile(StringRef Filename, off_t Size,
259
                                  time_t ModificationTime);
260
261
  /// Retrieve a FileEntry that bypasses VFE, which is expected to be a virtual
262
  /// file entry, to access the real file.  The returned FileEntry will have
263
  /// the same filename as FE but a different identity and its own stat.
264
  ///
265
  /// This should be used only for rare error recovery paths because it
266
  /// bypasses all mapping and uniquing, blindly creating a new FileEntry.
267
  /// There is no attempt to deduplicate these; if you bypass the same file
268
  /// twice, you get two new file entries.
269
  llvm::Optional<FileEntryRef> getBypassFile(FileEntryRef VFE);
270
271
  /// Open the specified file as a MemoryBuffer, returning a new
272
  /// MemoryBuffer if successful, otherwise returning null.
273
  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
274
  getBufferForFile(const FileEntry *Entry, bool isVolatile = false,
275
                   bool RequiresNullTerminator = true);
276
  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
277
  getBufferForFile(StringRef Filename, bool isVolatile = false,
278
4.13k
                   bool RequiresNullTerminator = true) {
279
4.13k
    return getBufferForFileImpl(Filename, /*FileSize=*/-1, isVolatile,
280
4.13k
                                RequiresNullTerminator);
281
4.13k
  }
282
283
private:
284
  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
285
  getBufferForFileImpl(StringRef Filename, int64_t FileSize, bool isVolatile,
286
                       bool RequiresNullTerminator);
287
288
public:
289
  /// Get the 'stat' information for the given \p Path.
290
  ///
291
  /// If the path is relative, it will be resolved against the WorkingDir of the
292
  /// FileManager's FileSystemOptions.
293
  ///
294
  /// \returns a \c std::error_code describing an error, if there was one
295
  std::error_code getNoncachedStatValue(StringRef Path,
296
                                        llvm::vfs::Status &Result);
297
298
  /// If path is not absolute and FileSystemOptions set the working
299
  /// directory, the path is modified to be relative to the given
300
  /// working directory.
301
  /// \returns true if \c path changed.
302
  bool FixupRelativePath(SmallVectorImpl<char> &path) const;
303
304
  /// Makes \c Path absolute taking into account FileSystemOptions and the
305
  /// working directory option.
306
  /// \returns true if \c Path changed to absolute.
307
  bool makeAbsolutePath(SmallVectorImpl<char> &Path) const;
308
309
  /// Produce an array mapping from the unique IDs assigned to each
310
  /// file to the corresponding FileEntry pointer.
311
  void GetUniqueIDMapping(
312
                    SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
313
314
  /// Retrieve the canonical name for a given directory.
315
  ///
316
  /// This is a very expensive operation, despite its results being cached,
317
  /// and should only be used when the physical layout of the file system is
318
  /// required, which is (almost) never.
319
  StringRef getCanonicalName(const DirectoryEntry *Dir);
320
321
  /// Retrieve the canonical name for a given file.
322
  ///
323
  /// This is a very expensive operation, despite its results being cached,
324
  /// and should only be used when the physical layout of the file system is
325
  /// required, which is (almost) never.
326
  StringRef getCanonicalName(const FileEntry *File);
327
328
  void PrintStats() const;
329
};
330
331
} // end namespace clang
332
333
#endif // LLVM_CLANG_BASIC_FILEMANAGER_H