clang  3.9.0
FileManager.cpp
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1 //===--- FileManager.cpp - File System Probing and Caching ----------------===//
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 // This file implements the FileManager interface.
11 //
12 //===----------------------------------------------------------------------===//
13 //
14 // TODO: This should index all interesting directories with dirent calls.
15 // getdirentries ?
16 // opendir/readdir_r/closedir ?
17 //
18 //===----------------------------------------------------------------------===//
19 
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/Config/llvm-config.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/MemoryBuffer.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include <map>
30 #include <set>
31 #include <string>
32 #include <system_error>
33 
34 using namespace clang;
35 
36 /// NON_EXISTENT_DIR - A special value distinct from null that is used to
37 /// represent a dir name that doesn't exist on the disk.
38 #define NON_EXISTENT_DIR reinterpret_cast<DirectoryEntry*>((intptr_t)-1)
39 
40 /// NON_EXISTENT_FILE - A special value distinct from null that is used to
41 /// represent a filename that doesn't exist on the disk.
42 #define NON_EXISTENT_FILE reinterpret_cast<FileEntry*>((intptr_t)-1)
43 
44 //===----------------------------------------------------------------------===//
45 // Common logic.
46 //===----------------------------------------------------------------------===//
47 
50  : FS(FS), FileSystemOpts(FSO),
51  SeenDirEntries(64), SeenFileEntries(64), NextFileUID(0) {
52  NumDirLookups = NumFileLookups = 0;
53  NumDirCacheMisses = NumFileCacheMisses = 0;
54 
55  // If the caller doesn't provide a virtual file system, just grab the real
56  // file system.
57  if (!FS)
58  this->FS = vfs::getRealFileSystem();
59 }
60 
61 FileManager::~FileManager() = default;
62 
63 void FileManager::addStatCache(std::unique_ptr<FileSystemStatCache> statCache,
64  bool AtBeginning) {
65  assert(statCache && "No stat cache provided?");
66  if (AtBeginning || !StatCache.get()) {
67  statCache->setNextStatCache(std::move(StatCache));
68  StatCache = std::move(statCache);
69  return;
70  }
71 
72  FileSystemStatCache *LastCache = StatCache.get();
73  while (LastCache->getNextStatCache())
74  LastCache = LastCache->getNextStatCache();
75 
76  LastCache->setNextStatCache(std::move(statCache));
77 }
78 
80  if (!statCache)
81  return;
82 
83  if (StatCache.get() == statCache) {
84  // This is the first stat cache.
85  StatCache = StatCache->takeNextStatCache();
86  return;
87  }
88 
89  // Find the stat cache in the list.
90  FileSystemStatCache *PrevCache = StatCache.get();
91  while (PrevCache && PrevCache->getNextStatCache() != statCache)
92  PrevCache = PrevCache->getNextStatCache();
93 
94  assert(PrevCache && "Stat cache not found for removal");
95  PrevCache->setNextStatCache(statCache->takeNextStatCache());
96 }
97 
99  StatCache.reset();
100 }
101 
102 /// \brief Retrieve the directory that the given file name resides in.
103 /// Filename can point to either a real file or a virtual file.
105  StringRef Filename,
106  bool CacheFailure) {
107  if (Filename.empty())
108  return nullptr;
109 
110  if (llvm::sys::path::is_separator(Filename[Filename.size() - 1]))
111  return nullptr; // If Filename is a directory.
112 
113  StringRef DirName = llvm::sys::path::parent_path(Filename);
114  // Use the current directory if file has no path component.
115  if (DirName.empty())
116  DirName = ".";
117 
118  return FileMgr.getDirectory(DirName, CacheFailure);
119 }
120 
121 /// Add all ancestors of the given path (pointing to either a file or
122 /// a directory) as virtual directories.
123 void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
124  StringRef DirName = llvm::sys::path::parent_path(Path);
125  if (DirName.empty())
126  DirName = ".";
127 
128  auto &NamedDirEnt =
129  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
130 
131  // When caching a virtual directory, we always cache its ancestors
132  // at the same time. Therefore, if DirName is already in the cache,
133  // we don't need to recurse as its ancestors must also already be in
134  // the cache.
135  if (NamedDirEnt.second && NamedDirEnt.second != NON_EXISTENT_DIR)
136  return;
137 
138  // Add the virtual directory to the cache.
139  auto UDE = llvm::make_unique<DirectoryEntry>();
140  UDE->Name = NamedDirEnt.first().data();
141  NamedDirEnt.second = UDE.get();
142  VirtualDirectoryEntries.push_back(std::move(UDE));
143 
144  // Recursively add the other ancestors.
145  addAncestorsAsVirtualDirs(DirName);
146 }
147 
148 const DirectoryEntry *FileManager::getDirectory(StringRef DirName,
149  bool CacheFailure) {
150  // stat doesn't like trailing separators except for root directory.
151  // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'.
152  // (though it can strip '\\')
153  if (DirName.size() > 1 &&
154  DirName != llvm::sys::path::root_path(DirName) &&
155  llvm::sys::path::is_separator(DirName.back()))
156  DirName = DirName.substr(0, DirName.size()-1);
157 #ifdef LLVM_ON_WIN32
158  // Fixing a problem with "clang C:test.c" on Windows.
159  // Stat("C:") does not recognize "C:" as a valid directory
160  std::string DirNameStr;
161  if (DirName.size() > 1 && DirName.back() == ':' &&
162  DirName.equals_lower(llvm::sys::path::root_name(DirName))) {
163  DirNameStr = DirName.str() + '.';
164  DirName = DirNameStr;
165  }
166 #endif
167 
168  ++NumDirLookups;
169  auto &NamedDirEnt =
170  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
171 
172  // See if there was already an entry in the map. Note that the map
173  // contains both virtual and real directories.
174  if (NamedDirEnt.second)
175  return NamedDirEnt.second == NON_EXISTENT_DIR ? nullptr
176  : NamedDirEnt.second;
177 
178  ++NumDirCacheMisses;
179 
180  // By default, initialize it to invalid.
181  NamedDirEnt.second = NON_EXISTENT_DIR;
182 
183  // Get the null-terminated directory name as stored as the key of the
184  // SeenDirEntries map.
185  const char *InterndDirName = NamedDirEnt.first().data();
186 
187  // Check to see if the directory exists.
188  FileData Data;
189  if (getStatValue(InterndDirName, Data, false, nullptr /*directory lookup*/)) {
190  // There's no real directory at the given path.
191  if (!CacheFailure)
192  SeenDirEntries.erase(DirName);
193  return nullptr;
194  }
195 
196  // It exists. See if we have already opened a directory with the
197  // same inode (this occurs on Unix-like systems when one dir is
198  // symlinked to another, for example) or the same path (on
199  // Windows).
200  DirectoryEntry &UDE = UniqueRealDirs[Data.UniqueID];
201 
202  NamedDirEnt.second = &UDE;
203  if (!UDE.getName()) {
204  // We don't have this directory yet, add it. We use the string
205  // key from the SeenDirEntries map as the string.
206  UDE.Name = InterndDirName;
207  }
208 
209  return &UDE;
210 }
211 
212 const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
213  bool CacheFailure) {
214  ++NumFileLookups;
215 
216  // See if there is already an entry in the map.
217  auto &NamedFileEnt =
218  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
219 
220  // See if there is already an entry in the map.
221  if (NamedFileEnt.second)
222  return NamedFileEnt.second == NON_EXISTENT_FILE ? nullptr
223  : NamedFileEnt.second;
224 
225  ++NumFileCacheMisses;
226 
227  // By default, initialize it to invalid.
228  NamedFileEnt.second = NON_EXISTENT_FILE;
229 
230  // Get the null-terminated file name as stored as the key of the
231  // SeenFileEntries map.
232  const char *InterndFileName = NamedFileEnt.first().data();
233 
234  // Look up the directory for the file. When looking up something like
235  // sys/foo.h we'll discover all of the search directories that have a 'sys'
236  // subdirectory. This will let us avoid having to waste time on known-to-fail
237  // searches when we go to find sys/bar.h, because all the search directories
238  // without a 'sys' subdir will get a cached failure result.
239  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
240  CacheFailure);
241  if (DirInfo == nullptr) { // Directory doesn't exist, file can't exist.
242  if (!CacheFailure)
243  SeenFileEntries.erase(Filename);
244 
245  return nullptr;
246  }
247 
248  // FIXME: Use the directory info to prune this, before doing the stat syscall.
249  // FIXME: This will reduce the # syscalls.
250 
251  // Nope, there isn't. Check to see if the file exists.
252  std::unique_ptr<vfs::File> F;
253  FileData Data;
254  if (getStatValue(InterndFileName, Data, true, openFile ? &F : nullptr)) {
255  // There's no real file at the given path.
256  if (!CacheFailure)
257  SeenFileEntries.erase(Filename);
258 
259  return nullptr;
260  }
261 
262  assert((openFile || !F) && "undesired open file");
263 
264  // It exists. See if we have already opened a file with the same inode.
265  // This occurs when one dir is symlinked to another, for example.
266  FileEntry &UFE = UniqueRealFiles[Data.UniqueID];
267 
268  NamedFileEnt.second = &UFE;
269 
270  // If the name returned by getStatValue is different than Filename, re-intern
271  // the name.
272  if (Data.Name != Filename) {
273  auto &NamedFileEnt =
274  *SeenFileEntries.insert(std::make_pair(Data.Name, nullptr)).first;
275  if (!NamedFileEnt.second)
276  NamedFileEnt.second = &UFE;
277  else
278  assert(NamedFileEnt.second == &UFE &&
279  "filename from getStatValue() refers to wrong file");
280  InterndFileName = NamedFileEnt.first().data();
281  }
282 
283  if (UFE.isValid()) { // Already have an entry with this inode, return it.
284 
285  // FIXME: this hack ensures that if we look up a file by a virtual path in
286  // the VFS that the getDir() will have the virtual path, even if we found
287  // the file by a 'real' path first. This is required in order to find a
288  // module's structure when its headers/module map are mapped in the VFS.
289  // We should remove this as soon as we can properly support a file having
290  // multiple names.
291  if (DirInfo != UFE.Dir && Data.IsVFSMapped)
292  UFE.Dir = DirInfo;
293 
294  // Always update the name to use the last name by which a file was accessed.
295  // FIXME: Neither this nor always using the first name is correct; we want
296  // to switch towards a design where we return a FileName object that
297  // encapsulates both the name by which the file was accessed and the
298  // corresponding FileEntry.
299  UFE.Name = InterndFileName;
300 
301  return &UFE;
302  }
303 
304  // Otherwise, we don't have this file yet, add it.
305  UFE.Name = InterndFileName;
306  UFE.Size = Data.Size;
307  UFE.ModTime = Data.ModTime;
308  UFE.Dir = DirInfo;
309  UFE.UID = NextFileUID++;
310  UFE.UniqueID = Data.UniqueID;
311  UFE.IsNamedPipe = Data.IsNamedPipe;
312  UFE.InPCH = Data.InPCH;
313  UFE.File = std::move(F);
314  UFE.IsValid = true;
315  if (UFE.File)
316  if (auto RealPathName = UFE.File->getName())
317  UFE.RealPathName = *RealPathName;
318  return &UFE;
319 }
320 
321 const FileEntry *
322 FileManager::getVirtualFile(StringRef Filename, off_t Size,
323  time_t ModificationTime) {
324  ++NumFileLookups;
325 
326  // See if there is already an entry in the map.
327  auto &NamedFileEnt =
328  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
329 
330  // See if there is already an entry in the map.
331  if (NamedFileEnt.second && NamedFileEnt.second != NON_EXISTENT_FILE)
332  return NamedFileEnt.second;
333 
334  ++NumFileCacheMisses;
335 
336  // By default, initialize it to invalid.
337  NamedFileEnt.second = NON_EXISTENT_FILE;
338 
339  addAncestorsAsVirtualDirs(Filename);
340  FileEntry *UFE = nullptr;
341 
342  // Now that all ancestors of Filename are in the cache, the
343  // following call is guaranteed to find the DirectoryEntry from the
344  // cache.
345  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
346  /*CacheFailure=*/true);
347  assert(DirInfo &&
348  "The directory of a virtual file should already be in the cache.");
349 
350  // Check to see if the file exists. If so, drop the virtual file
351  FileData Data;
352  const char *InterndFileName = NamedFileEnt.first().data();
353  if (getStatValue(InterndFileName, Data, true, nullptr) == 0) {
354  Data.Size = Size;
355  Data.ModTime = ModificationTime;
356  UFE = &UniqueRealFiles[Data.UniqueID];
357 
358  NamedFileEnt.second = UFE;
359 
360  // If we had already opened this file, close it now so we don't
361  // leak the descriptor. We're not going to use the file
362  // descriptor anyway, since this is a virtual file.
363  if (UFE->File)
364  UFE->closeFile();
365 
366  // If we already have an entry with this inode, return it.
367  if (UFE->isValid())
368  return UFE;
369 
370  UFE->UniqueID = Data.UniqueID;
371  UFE->IsNamedPipe = Data.IsNamedPipe;
372  UFE->InPCH = Data.InPCH;
373  }
374 
375  if (!UFE) {
376  VirtualFileEntries.push_back(llvm::make_unique<FileEntry>());
377  UFE = VirtualFileEntries.back().get();
378  NamedFileEnt.second = UFE;
379  }
380 
381  UFE->Name = InterndFileName;
382  UFE->Size = Size;
383  UFE->ModTime = ModificationTime;
384  UFE->Dir = DirInfo;
385  UFE->UID = NextFileUID++;
386  UFE->File.reset();
387  return UFE;
388 }
389 
391  StringRef pathRef(path.data(), path.size());
392 
393  if (FileSystemOpts.WorkingDir.empty()
394  || llvm::sys::path::is_absolute(pathRef))
395  return false;
396 
397  SmallString<128> NewPath(FileSystemOpts.WorkingDir);
398  llvm::sys::path::append(NewPath, pathRef);
399  path = NewPath;
400  return true;
401 }
402 
404  bool Changed = FixupRelativePath(Path);
405 
406  if (!llvm::sys::path::is_absolute(StringRef(Path.data(), Path.size()))) {
407  llvm::sys::fs::make_absolute(Path);
408  Changed = true;
409  }
410 
411  return Changed;
412 }
413 
414 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
415 FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile,
416  bool ShouldCloseOpenFile) {
417  uint64_t FileSize = Entry->getSize();
418  // If there's a high enough chance that the file have changed since we
419  // got its size, force a stat before opening it.
420  if (isVolatile)
421  FileSize = -1;
422 
423  const char *Filename = Entry->getName();
424  // If the file is already open, use the open file descriptor.
425  if (Entry->File) {
426  auto Result =
427  Entry->File->getBuffer(Filename, FileSize,
428  /*RequiresNullTerminator=*/true, isVolatile);
429  // FIXME: we need a set of APIs that can make guarantees about whether a
430  // FileEntry is open or not.
431  if (ShouldCloseOpenFile)
432  Entry->closeFile();
433  return Result;
434  }
435 
436  // Otherwise, open the file.
437 
438  if (FileSystemOpts.WorkingDir.empty())
439  return FS->getBufferForFile(Filename, FileSize,
440  /*RequiresNullTerminator=*/true, isVolatile);
441 
444  return FS->getBufferForFile(FilePath, FileSize,
445  /*RequiresNullTerminator=*/true, isVolatile);
446 }
447 
448 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
450  if (FileSystemOpts.WorkingDir.empty())
451  return FS->getBufferForFile(Filename);
452 
453  SmallString<128> FilePath(Filename);
454  FixupRelativePath(FilePath);
455  return FS->getBufferForFile(FilePath.c_str());
456 }
457 
458 /// getStatValue - Get the 'stat' information for the specified path,
459 /// using the cache to accelerate it if possible. This returns true
460 /// if the path points to a virtual file or does not exist, or returns
461 /// false if it's an existent real file. If FileDescriptor is NULL,
462 /// do directory look-up instead of file look-up.
463 bool FileManager::getStatValue(const char *Path, FileData &Data, bool isFile,
464  std::unique_ptr<vfs::File> *F) {
465  // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
466  // absolute!
467  if (FileSystemOpts.WorkingDir.empty())
468  return FileSystemStatCache::get(Path, Data, isFile, F,StatCache.get(), *FS);
469 
472 
473  return FileSystemStatCache::get(FilePath.c_str(), Data, isFile, F,
474  StatCache.get(), *FS);
475 }
476 
478  vfs::Status &Result) {
480  FixupRelativePath(FilePath);
481 
482  llvm::ErrorOr<vfs::Status> S = FS->status(FilePath.c_str());
483  if (!S)
484  return true;
485  Result = *S;
486  return false;
487 }
488 
490  assert(Entry && "Cannot invalidate a NULL FileEntry");
491 
492  SeenFileEntries.erase(Entry->getName());
493 
494  // FileEntry invalidation should not block future optimizations in the file
495  // caches. Possible alternatives are cache truncation (invalidate last N) or
496  // invalidation of the whole cache.
497  UniqueRealFiles.erase(Entry->getUniqueID());
498 }
499 
500 
502  SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
503  UIDToFiles.clear();
504  UIDToFiles.resize(NextFileUID);
505 
506  // Map file entries
507  for (llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator>::const_iterator
508  FE = SeenFileEntries.begin(), FEEnd = SeenFileEntries.end();
509  FE != FEEnd; ++FE)
510  if (FE->getValue() && FE->getValue() != NON_EXISTENT_FILE)
511  UIDToFiles[FE->getValue()->getUID()] = FE->getValue();
512 
513  // Map virtual file entries
514  for (const auto &VFE : VirtualFileEntries)
515  if (VFE && VFE.get() != NON_EXISTENT_FILE)
516  UIDToFiles[VFE->getUID()] = VFE.get();
517 }
518 
520  off_t Size, time_t ModificationTime) {
521  File->Size = Size;
522  File->ModTime = ModificationTime;
523 }
524 
526  // FIXME: use llvm::sys::fs::canonical() when it gets implemented
528  = CanonicalDirNames.find(Dir);
529  if (Known != CanonicalDirNames.end())
530  return Known->second;
531 
532  StringRef CanonicalName(Dir->getName());
533 
534 #ifdef LLVM_ON_UNIX
535  char CanonicalNameBuf[PATH_MAX];
536  if (realpath(Dir->getName(), CanonicalNameBuf))
537  CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
538 #else
539  SmallString<256> CanonicalNameBuf(CanonicalName);
540  llvm::sys::fs::make_absolute(CanonicalNameBuf);
541  llvm::sys::path::native(CanonicalNameBuf);
542  // We've run into needing to remove '..' here in the wild though, so
543  // remove it.
544  // On Windows, symlinks are significantly less prevalent, so removing
545  // '..' is pretty safe.
546  // Ideally we'd have an equivalent of `realpath` and could implement
547  // sys::fs::canonical across all the platforms.
548  llvm::sys::path::remove_dots(CanonicalNameBuf, /* remove_dot_dot */ true);
549  CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
550 #endif
551 
552  CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
553  return CanonicalName;
554 }
555 
557  llvm::errs() << "\n*** File Manager Stats:\n";
558  llvm::errs() << UniqueRealFiles.size() << " real files found, "
559  << UniqueRealDirs.size() << " real dirs found.\n";
560  llvm::errs() << VirtualFileEntries.size() << " virtual files found, "
561  << VirtualDirectoryEntries.size() << " virtual dirs found.\n";
562  llvm::errs() << NumDirLookups << " dir lookups, "
563  << NumDirCacheMisses << " dir cache misses.\n";
564  llvm::errs() << NumFileLookups << " file lookups, "
565  << NumFileCacheMisses << " file cache misses.\n";
566 
567  //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups;
568 }
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:117
Defines the clang::FileManager interface and associated types.
IntrusiveRefCntPtr< FileSystem > getRealFileSystem()
Gets an vfs::FileSystem for the 'real' file system, as seen by the operating system.
bool isValid() const
Definition: FileManager.h:87
Defines the FileSystemStatCache interface.
FileManager(const FileSystemOptions &FileSystemOpts, IntrusiveRefCntPtr< vfs::FileSystem > FS=nullptr)
Definition: FileManager.cpp:48
static bool get(const char *Path, FileData &Data, bool isFile, std::unique_ptr< vfs::File > *F, FileSystemStatCache *Cache, vfs::FileSystem &FS)
Get the 'stat' information for the specified path, using the cache to accelerate it if possible...
#define NON_EXISTENT_DIR
NON_EXISTENT_DIR - A special value distinct from null that is used to represent a dir name that doesn...
Definition: FileManager.cpp:38
off_t getSize() const
Definition: FileManager.h:88
const StringRef FilePath
#define NON_EXISTENT_FILE
NON_EXISTENT_FILE - A special value distinct from null that is used to represent a filename that does...
Definition: FileManager.cpp:42
bool makeAbsolutePath(SmallVectorImpl< char > &Path) const
Makes Path absolute taking into account FileSystemOptions and the working directory option...
Abstract interface for introducing a FileManager cache for 'stat' system calls, which is used by prec...
std::unique_ptr< FileSystemStatCache > takeNextStatCache()
Retrieve the next stat call cache in the chain, transferring ownership of this cache (and...
The result of a status operation.
const FileEntry * getFile(StringRef Filename, bool OpenFile=false, bool CacheFailure=true)
Lookup, cache, and verify the specified file (real or virtual).
const DirectoryEntry * getDirectory(StringRef DirName, bool CacheFailure=true)
Lookup, cache, and verify the specified directory (real or virtual).
StringRef Filename
Definition: Format.cpp:1194
static const DirectoryEntry * getDirectoryFromFile(FileManager &FileMgr, StringRef Filename, bool CacheFailure)
Retrieve the directory that the given file name resides in.
const llvm::sys::fs::UniqueID & getUniqueID() const
Definition: FileManager.h:90
void setNextStatCache(std::unique_ptr< FileSystemStatCache > Cache)
Sets the next stat call cache in the chain of stat caches.
std::string WorkingDir
If set, paths are resolved as if the working directory was set to the value of WorkingDir.
The result type of a method or function.
void addStatCache(std::unique_ptr< FileSystemStatCache > statCache, bool AtBeginning=false)
Installs the provided FileSystemStatCache object within the FileManager.
Definition: FileManager.cpp:63
const char * getName() const
Definition: FileManager.h:85
llvm::sys::fs::UniqueID UniqueID
const TemplateArgument * iterator
Definition: Type.h:4233
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:53
void clearStatCaches()
Removes all FileSystemStatCache objects from the manager.
Definition: FileManager.cpp:98
const FileEntry * getVirtualFile(StringRef Filename, off_t Size, time_t ModificationTime)
Retrieve a file entry for a "virtual" file that acts as if there were a file with the given name on d...
const char * getName() const
Definition: FileManager.h:45
StringRef getCanonicalName(const DirectoryEntry *Dir)
Retrieve the canonical name for a given directory.
void removeStatCache(FileSystemStatCache *statCache)
Removes the specified FileSystemStatCache object from the manager.
Definition: FileManager.cpp:79
llvm::ErrorOr< std::unique_ptr< llvm::MemoryBuffer > > getBufferForFile(const FileEntry *Entry, bool isVolatile=false, bool ShouldCloseOpenFile=true)
Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.
void closeFile() const
Definition: FileManager.h:103
Cached information about one directory (either on disk or in the virtual file system).
Definition: FileManager.h:40
Keeps track of options that affect how file operations are performed.
bool getNoncachedStatValue(StringRef Path, vfs::Status &Result)
Get the 'stat' information for the given Path.
static void modifyFileEntry(FileEntry *File, off_t Size, time_t ModificationTime)
Modifies the size and modification time of a previously created FileEntry.
void PrintStats() const
void invalidateCache(const FileEntry *Entry)
Remove the real file Entry from the cache.
bool FixupRelativePath(SmallVectorImpl< char > &path) const
If path is not absolute and FileSystemOptions set the working directory, the path is modified to be r...
FileSystemStatCache * getNextStatCache()
Retrieve the next stat call cache in the chain.
void GetUniqueIDMapping(SmallVectorImpl< const FileEntry * > &UIDToFiles) const
Produce an array mapping from the unique IDs assigned to each file to the corresponding FileEntry poi...