clang  3.7.0
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 
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/Config/llvm-config.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 
62  for (unsigned i = 0, e = VirtualFileEntries.size(); i != e; ++i)
63  delete VirtualFileEntries[i];
64  for (unsigned i = 0, e = VirtualDirectoryEntries.size(); i != e; ++i)
65  delete VirtualDirectoryEntries[i];
66 }
67 
68 void FileManager::addStatCache(std::unique_ptr<FileSystemStatCache> statCache,
69  bool AtBeginning) {
70  assert(statCache && "No stat cache provided?");
71  if (AtBeginning || !StatCache.get()) {
72  statCache->setNextStatCache(std::move(StatCache));
73  StatCache = std::move(statCache);
74  return;
75  }
76 
77  FileSystemStatCache *LastCache = StatCache.get();
78  while (LastCache->getNextStatCache())
79  LastCache = LastCache->getNextStatCache();
80 
81  LastCache->setNextStatCache(std::move(statCache));
82 }
83 
85  if (!statCache)
86  return;
87 
88  if (StatCache.get() == statCache) {
89  // This is the first stat cache.
90  StatCache = StatCache->takeNextStatCache();
91  return;
92  }
93 
94  // Find the stat cache in the list.
95  FileSystemStatCache *PrevCache = StatCache.get();
96  while (PrevCache && PrevCache->getNextStatCache() != statCache)
97  PrevCache = PrevCache->getNextStatCache();
98 
99  assert(PrevCache && "Stat cache not found for removal");
100  PrevCache->setNextStatCache(statCache->takeNextStatCache());
101 }
102 
104  StatCache.reset();
105 }
106 
107 /// \brief Retrieve the directory that the given file name resides in.
108 /// Filename can point to either a real file or a virtual file.
110  StringRef Filename,
111  bool CacheFailure) {
112  if (Filename.empty())
113  return nullptr;
114 
115  if (llvm::sys::path::is_separator(Filename[Filename.size() - 1]))
116  return nullptr; // If Filename is a directory.
117 
118  StringRef DirName = llvm::sys::path::parent_path(Filename);
119  // Use the current directory if file has no path component.
120  if (DirName.empty())
121  DirName = ".";
122 
123  return FileMgr.getDirectory(DirName, CacheFailure);
124 }
125 
126 /// Add all ancestors of the given path (pointing to either a file or
127 /// a directory) as virtual directories.
128 void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
129  StringRef DirName = llvm::sys::path::parent_path(Path);
130  if (DirName.empty())
131  return;
132 
133  auto &NamedDirEnt =
134  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
135 
136  // When caching a virtual directory, we always cache its ancestors
137  // at the same time. Therefore, if DirName is already in the cache,
138  // we don't need to recurse as its ancestors must also already be in
139  // the cache.
140  if (NamedDirEnt.second)
141  return;
142 
143  // Add the virtual directory to the cache.
144  DirectoryEntry *UDE = new DirectoryEntry;
145  UDE->Name = NamedDirEnt.first().data();
146  NamedDirEnt.second = UDE;
147  VirtualDirectoryEntries.push_back(UDE);
148 
149  // Recursively add the other ancestors.
150  addAncestorsAsVirtualDirs(DirName);
151 }
152 
153 const DirectoryEntry *FileManager::getDirectory(StringRef DirName,
154  bool CacheFailure) {
155  // stat doesn't like trailing separators except for root directory.
156  // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'.
157  // (though it can strip '\\')
158  if (DirName.size() > 1 &&
159  DirName != llvm::sys::path::root_path(DirName) &&
160  llvm::sys::path::is_separator(DirName.back()))
161  DirName = DirName.substr(0, DirName.size()-1);
162 #ifdef LLVM_ON_WIN32
163  // Fixing a problem with "clang C:test.c" on Windows.
164  // Stat("C:") does not recognize "C:" as a valid directory
165  std::string DirNameStr;
166  if (DirName.size() > 1 && DirName.back() == ':' &&
167  DirName.equals_lower(llvm::sys::path::root_name(DirName))) {
168  DirNameStr = DirName.str() + '.';
169  DirName = DirNameStr;
170  }
171 #endif
172 
173  ++NumDirLookups;
174  auto &NamedDirEnt =
175  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
176 
177  // See if there was already an entry in the map. Note that the map
178  // contains both virtual and real directories.
179  if (NamedDirEnt.second)
180  return NamedDirEnt.second == NON_EXISTENT_DIR ? nullptr
181  : NamedDirEnt.second;
182 
183  ++NumDirCacheMisses;
184 
185  // By default, initialize it to invalid.
186  NamedDirEnt.second = NON_EXISTENT_DIR;
187 
188  // Get the null-terminated directory name as stored as the key of the
189  // SeenDirEntries map.
190  const char *InterndDirName = NamedDirEnt.first().data();
191 
192  // Check to see if the directory exists.
193  FileData Data;
194  if (getStatValue(InterndDirName, Data, false, nullptr /*directory lookup*/)) {
195  // There's no real directory at the given path.
196  if (!CacheFailure)
197  SeenDirEntries.erase(DirName);
198  return nullptr;
199  }
200 
201  // It exists. See if we have already opened a directory with the
202  // same inode (this occurs on Unix-like systems when one dir is
203  // symlinked to another, for example) or the same path (on
204  // Windows).
205  DirectoryEntry &UDE = UniqueRealDirs[Data.UniqueID];
206 
207  NamedDirEnt.second = &UDE;
208  if (!UDE.getName()) {
209  // We don't have this directory yet, add it. We use the string
210  // key from the SeenDirEntries map as the string.
211  UDE.Name = InterndDirName;
212  }
213 
214  return &UDE;
215 }
216 
217 const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
218  bool CacheFailure) {
219  ++NumFileLookups;
220 
221  // See if there is already an entry in the map.
222  auto &NamedFileEnt =
223  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
224 
225  // See if there is already an entry in the map.
226  if (NamedFileEnt.second)
227  return NamedFileEnt.second == NON_EXISTENT_FILE ? nullptr
228  : NamedFileEnt.second;
229 
230  ++NumFileCacheMisses;
231 
232  // By default, initialize it to invalid.
233  NamedFileEnt.second = NON_EXISTENT_FILE;
234 
235  // Get the null-terminated file name as stored as the key of the
236  // SeenFileEntries map.
237  const char *InterndFileName = NamedFileEnt.first().data();
238 
239  // Look up the directory for the file. When looking up something like
240  // sys/foo.h we'll discover all of the search directories that have a 'sys'
241  // subdirectory. This will let us avoid having to waste time on known-to-fail
242  // searches when we go to find sys/bar.h, because all the search directories
243  // without a 'sys' subdir will get a cached failure result.
244  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
245  CacheFailure);
246  if (DirInfo == nullptr) { // Directory doesn't exist, file can't exist.
247  if (!CacheFailure)
248  SeenFileEntries.erase(Filename);
249 
250  return nullptr;
251  }
252 
253  // FIXME: Use the directory info to prune this, before doing the stat syscall.
254  // FIXME: This will reduce the # syscalls.
255 
256  // Nope, there isn't. Check to see if the file exists.
257  std::unique_ptr<vfs::File> F;
258  FileData Data;
259  if (getStatValue(InterndFileName, Data, true, openFile ? &F : nullptr)) {
260  // There's no real file at the given path.
261  if (!CacheFailure)
262  SeenFileEntries.erase(Filename);
263 
264  return nullptr;
265  }
266 
267  assert((openFile || !F) && "undesired open file");
268 
269  // It exists. See if we have already opened a file with the same inode.
270  // This occurs when one dir is symlinked to another, for example.
271  FileEntry &UFE = UniqueRealFiles[Data.UniqueID];
272 
273  NamedFileEnt.second = &UFE;
274 
275  // If the name returned by getStatValue is different than Filename, re-intern
276  // the name.
277  if (Data.Name != Filename) {
278  auto &NamedFileEnt =
279  *SeenFileEntries.insert(std::make_pair(Data.Name, nullptr)).first;
280  if (!NamedFileEnt.second)
281  NamedFileEnt.second = &UFE;
282  else
283  assert(NamedFileEnt.second == &UFE &&
284  "filename from getStatValue() refers to wrong file");
285  InterndFileName = NamedFileEnt.first().data();
286  }
287 
288  if (UFE.isValid()) { // Already have an entry with this inode, return it.
289 
290  // FIXME: this hack ensures that if we look up a file by a virtual path in
291  // the VFS that the getDir() will have the virtual path, even if we found
292  // the file by a 'real' path first. This is required in order to find a
293  // module's structure when its headers/module map are mapped in the VFS.
294  // We should remove this as soon as we can properly support a file having
295  // multiple names.
296  if (DirInfo != UFE.Dir && Data.IsVFSMapped)
297  UFE.Dir = DirInfo;
298 
299  // Always update the name to use the last name by which a file was accessed.
300  // FIXME: Neither this nor always using the first name is correct; we want
301  // to switch towards a design where we return a FileName object that
302  // encapsulates both the name by which the file was accessed and the
303  // corresponding FileEntry.
304  UFE.Name = InterndFileName;
305 
306  return &UFE;
307  }
308 
309  // Otherwise, we don't have this file yet, add it.
310  UFE.Name = InterndFileName;
311  UFE.Size = Data.Size;
312  UFE.ModTime = Data.ModTime;
313  UFE.Dir = DirInfo;
314  UFE.UID = NextFileUID++;
315  UFE.UniqueID = Data.UniqueID;
316  UFE.IsNamedPipe = Data.IsNamedPipe;
317  UFE.InPCH = Data.InPCH;
318  UFE.File = std::move(F);
319  UFE.IsValid = true;
320  return &UFE;
321 }
322 
323 const FileEntry *
324 FileManager::getVirtualFile(StringRef Filename, off_t Size,
325  time_t ModificationTime) {
326  ++NumFileLookups;
327 
328  // See if there is already an entry in the map.
329  auto &NamedFileEnt =
330  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
331 
332  // See if there is already an entry in the map.
333  if (NamedFileEnt.second && NamedFileEnt.second != NON_EXISTENT_FILE)
334  return NamedFileEnt.second;
335 
336  ++NumFileCacheMisses;
337 
338  // By default, initialize it to invalid.
339  NamedFileEnt.second = NON_EXISTENT_FILE;
340 
341  addAncestorsAsVirtualDirs(Filename);
342  FileEntry *UFE = nullptr;
343 
344  // Now that all ancestors of Filename are in the cache, the
345  // following call is guaranteed to find the DirectoryEntry from the
346  // cache.
347  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
348  /*CacheFailure=*/true);
349  assert(DirInfo &&
350  "The directory of a virtual file should already be in the cache.");
351 
352  // Check to see if the file exists. If so, drop the virtual file
353  FileData Data;
354  const char *InterndFileName = NamedFileEnt.first().data();
355  if (getStatValue(InterndFileName, Data, true, nullptr) == 0) {
356  Data.Size = Size;
357  Data.ModTime = ModificationTime;
358  UFE = &UniqueRealFiles[Data.UniqueID];
359 
360  NamedFileEnt.second = UFE;
361 
362  // If we had already opened this file, close it now so we don't
363  // leak the descriptor. We're not going to use the file
364  // descriptor anyway, since this is a virtual file.
365  if (UFE->File)
366  UFE->closeFile();
367 
368  // If we already have an entry with this inode, return it.
369  if (UFE->isValid())
370  return UFE;
371 
372  UFE->UniqueID = Data.UniqueID;
373  UFE->IsNamedPipe = Data.IsNamedPipe;
374  UFE->InPCH = Data.InPCH;
375  }
376 
377  if (!UFE) {
378  UFE = new FileEntry();
379  VirtualFileEntries.push_back(UFE);
380  NamedFileEnt.second = UFE;
381  }
382 
383  UFE->Name = InterndFileName;
384  UFE->Size = Size;
385  UFE->ModTime = ModificationTime;
386  UFE->Dir = DirInfo;
387  UFE->UID = NextFileUID++;
388  UFE->File.reset();
389  return UFE;
390 }
391 
393  StringRef pathRef(path.data(), path.size());
394 
395  if (FileSystemOpts.WorkingDir.empty()
396  || llvm::sys::path::is_absolute(pathRef))
397  return;
398 
399  SmallString<128> NewPath(FileSystemOpts.WorkingDir);
400  llvm::sys::path::append(NewPath, pathRef);
401  path = NewPath;
402 }
403 
404 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
405 FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile,
406  bool ShouldCloseOpenFile) {
407  uint64_t FileSize = Entry->getSize();
408  // If there's a high enough chance that the file have changed since we
409  // got its size, force a stat before opening it.
410  if (isVolatile)
411  FileSize = -1;
412 
413  const char *Filename = Entry->getName();
414  // If the file is already open, use the open file descriptor.
415  if (Entry->File) {
416  auto Result =
417  Entry->File->getBuffer(Filename, FileSize,
418  /*RequiresNullTerminator=*/true, isVolatile);
419  // FIXME: we need a set of APIs that can make guarantees about whether a
420  // FileEntry is open or not.
421  if (ShouldCloseOpenFile)
422  Entry->closeFile();
423  return Result;
424  }
425 
426  // Otherwise, open the file.
427 
428  if (FileSystemOpts.WorkingDir.empty())
429  return FS->getBufferForFile(Filename, FileSize,
430  /*RequiresNullTerminator=*/true, isVolatile);
431 
432  SmallString<128> FilePath(Entry->getName());
433  FixupRelativePath(FilePath);
434  return FS->getBufferForFile(FilePath, FileSize,
435  /*RequiresNullTerminator=*/true, isVolatile);
436 }
437 
438 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
439 FileManager::getBufferForFile(StringRef Filename) {
440  if (FileSystemOpts.WorkingDir.empty())
441  return FS->getBufferForFile(Filename);
442 
443  SmallString<128> FilePath(Filename);
444  FixupRelativePath(FilePath);
445  return FS->getBufferForFile(FilePath.c_str());
446 }
447 
448 /// getStatValue - Get the 'stat' information for the specified path,
449 /// using the cache to accelerate it if possible. This returns true
450 /// if the path points to a virtual file or does not exist, or returns
451 /// false if it's an existent real file. If FileDescriptor is NULL,
452 /// do directory look-up instead of file look-up.
453 bool FileManager::getStatValue(const char *Path, FileData &Data, bool isFile,
454  std::unique_ptr<vfs::File> *F) {
455  // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
456  // absolute!
457  if (FileSystemOpts.WorkingDir.empty())
458  return FileSystemStatCache::get(Path, Data, isFile, F,StatCache.get(), *FS);
459 
460  SmallString<128> FilePath(Path);
461  FixupRelativePath(FilePath);
462 
463  return FileSystemStatCache::get(FilePath.c_str(), Data, isFile, F,
464  StatCache.get(), *FS);
465 }
466 
468  vfs::Status &Result) {
469  SmallString<128> FilePath(Path);
470  FixupRelativePath(FilePath);
471 
472  llvm::ErrorOr<vfs::Status> S = FS->status(FilePath.c_str());
473  if (!S)
474  return true;
475  Result = *S;
476  return false;
477 }
478 
480  assert(Entry && "Cannot invalidate a NULL FileEntry");
481 
482  SeenFileEntries.erase(Entry->getName());
483 
484  // FileEntry invalidation should not block future optimizations in the file
485  // caches. Possible alternatives are cache truncation (invalidate last N) or
486  // invalidation of the whole cache.
487  UniqueRealFiles.erase(Entry->getUniqueID());
488 }
489 
490 
492  SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
493  UIDToFiles.clear();
494  UIDToFiles.resize(NextFileUID);
495 
496  // Map file entries
497  for (llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator>::const_iterator
498  FE = SeenFileEntries.begin(), FEEnd = SeenFileEntries.end();
499  FE != FEEnd; ++FE)
500  if (FE->getValue() && FE->getValue() != NON_EXISTENT_FILE)
501  UIDToFiles[FE->getValue()->getUID()] = FE->getValue();
502 
503  // Map virtual file entries
505  VFE = VirtualFileEntries.begin(), VFEEnd = VirtualFileEntries.end();
506  VFE != VFEEnd; ++VFE)
507  if (*VFE && *VFE != NON_EXISTENT_FILE)
508  UIDToFiles[(*VFE)->getUID()] = *VFE;
509 }
510 
512  off_t Size, time_t ModificationTime) {
513  File->Size = Size;
514  File->ModTime = ModificationTime;
515 }
516 
517 /// Remove '.' path components from the given absolute path.
518 /// \return \c true if any changes were made.
519 // FIXME: Move this to llvm::sys::path.
521  using namespace llvm::sys;
522 
523  SmallVector<StringRef, 16> ComponentStack;
524  StringRef P(Path.data(), Path.size());
525 
526  // Skip the root path, then look for traversal in the components.
527  StringRef Rel = path::relative_path(P);
528  bool AnyDots = false;
529  for (StringRef C : llvm::make_range(path::begin(Rel), path::end(Rel))) {
530  if (C == ".") {
531  AnyDots = true;
532  continue;
533  }
534  ComponentStack.push_back(C);
535  }
536 
537  if (!AnyDots)
538  return false;
539 
540  SmallString<256> Buffer = path::root_path(P);
541  for (StringRef C : ComponentStack)
542  path::append(Buffer, C);
543 
544  Path.swap(Buffer);
545  return true;
546 }
547 
549  // FIXME: use llvm::sys::fs::canonical() when it gets implemented
550  llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known
551  = CanonicalDirNames.find(Dir);
552  if (Known != CanonicalDirNames.end())
553  return Known->second;
554 
555  StringRef CanonicalName(Dir->getName());
556 
557 #ifdef LLVM_ON_UNIX
558  char CanonicalNameBuf[PATH_MAX];
559  if (realpath(Dir->getName(), CanonicalNameBuf)) {
560  unsigned Len = strlen(CanonicalNameBuf);
561  char *Mem = static_cast<char *>(CanonicalNameStorage.Allocate(Len, 1));
562  memcpy(Mem, CanonicalNameBuf, Len);
563  CanonicalName = StringRef(Mem, Len);
564  }
565 #else
566  SmallString<256> CanonicalNameBuf(CanonicalName);
567  llvm::sys::fs::make_absolute(CanonicalNameBuf);
568  llvm::sys::path::native(CanonicalNameBuf);
569  removeDotPaths(CanonicalNameBuf);
570 #endif
571 
572  CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
573  return CanonicalName;
574 }
575 
577  llvm::errs() << "\n*** File Manager Stats:\n";
578  llvm::errs() << UniqueRealFiles.size() << " real files found, "
579  << UniqueRealDirs.size() << " real dirs found.\n";
580  llvm::errs() << VirtualFileEntries.size() << " virtual files found, "
581  << VirtualDirectoryEntries.size() << " virtual dirs found.\n";
582  llvm::errs() << NumDirLookups << " dir lookups, "
583  << NumDirCacheMisses << " dir cache misses.\n";
584  llvm::errs() << NumFileLookups << " file lookups, "
585  << NumFileCacheMisses << " file cache misses.\n";
586 
587  //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups;
588 }
589 
590 // Virtual destructors for abstract base classes that need live in Basic.
static bool removeDotPaths(SmallVectorImpl< char > &Path)
Remove any './' components from a path.
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:115
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:85
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
Definition: FileManager.cpp:38
off_t getSize() const
Definition: FileManager.h:86
void FixupRelativePath(SmallVectorImpl< char > &path) const
If path is not absolute and FileSystemOptions set the working directory, the path is modified to be r...
#define NON_EXISTENT_FILE
Definition: FileManager.cpp:42
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.
AnnotatingParser & P
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).
static const DirectoryEntry * getDirectoryFromFile(FileManager &FileMgr, StringRef Filename, bool CacheFailure)
Retrieve the directory that the given file name resides in. Filename can point to either a real file ...
const llvm::sys::fs::UniqueID & getUniqueID() const
Definition: FileManager.h:88
void setNextStatCache(std::unique_ptr< FileSystemStatCache > Cache)
Sets the next stat call cache in the chain of stat caches. Takes ownership of the given stat cache...
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:68
const char * getName() const
Definition: FileManager.h:84
llvm::sys::fs::UniqueID UniqueID
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.
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:84
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:101
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. Use with caution...
void PrintStats() const
void invalidateCache(const FileEntry *Entry)
Remove the real file Entry from the cache.
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...