clang  8.0.0svn
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 <algorithm>
30 #include <cassert>
31 #include <climits>
32 #include <cstdint>
33 #include <cstdlib>
34 #include <string>
35 #include <utility>
36 
37 using namespace clang;
38 
39 /// NON_EXISTENT_DIR - A special value distinct from null that is used to
40 /// represent a dir name that doesn't exist on the disk.
41 #define NON_EXISTENT_DIR reinterpret_cast<DirectoryEntry*>((intptr_t)-1)
42 
43 /// NON_EXISTENT_FILE - A special value distinct from null that is used to
44 /// represent a filename that doesn't exist on the disk.
45 #define NON_EXISTENT_FILE reinterpret_cast<FileEntry*>((intptr_t)-1)
46 
47 //===----------------------------------------------------------------------===//
48 // Common logic.
49 //===----------------------------------------------------------------------===//
50 
53  : FS(std::move(FS)), FileSystemOpts(FSO), SeenDirEntries(64),
54  SeenFileEntries(64), NextFileUID(0) {
55  NumDirLookups = NumFileLookups = 0;
56  NumDirCacheMisses = NumFileCacheMisses = 0;
57 
58  // If the caller doesn't provide a virtual file system, just grab the real
59  // file system.
60  if (!this->FS)
61  this->FS = llvm::vfs::getRealFileSystem();
62 }
63 
64 FileManager::~FileManager() = default;
65 
66 void FileManager::addStatCache(std::unique_ptr<FileSystemStatCache> statCache,
67  bool AtBeginning) {
68  assert(statCache && "No stat cache provided?");
69  if (AtBeginning || !StatCache.get()) {
70  statCache->setNextStatCache(std::move(StatCache));
71  StatCache = std::move(statCache);
72  return;
73  }
74 
75  FileSystemStatCache *LastCache = StatCache.get();
76  while (LastCache->getNextStatCache())
77  LastCache = LastCache->getNextStatCache();
78 
79  LastCache->setNextStatCache(std::move(statCache));
80 }
81 
83  if (!statCache)
84  return;
85 
86  if (StatCache.get() == statCache) {
87  // This is the first stat cache.
88  StatCache = StatCache->takeNextStatCache();
89  return;
90  }
91 
92  // Find the stat cache in the list.
93  FileSystemStatCache *PrevCache = StatCache.get();
94  while (PrevCache && PrevCache->getNextStatCache() != statCache)
95  PrevCache = PrevCache->getNextStatCache();
96 
97  assert(PrevCache && "Stat cache not found for removal");
98  PrevCache->setNextStatCache(statCache->takeNextStatCache());
99 }
100 
102  StatCache.reset();
103 }
104 
105 /// Retrieve the directory that the given file name resides in.
106 /// Filename can point to either a real file or a virtual file.
108  StringRef Filename,
109  bool CacheFailure) {
110  if (Filename.empty())
111  return nullptr;
112 
113  if (llvm::sys::path::is_separator(Filename[Filename.size() - 1]))
114  return nullptr; // If Filename is a directory.
115 
116  StringRef DirName = llvm::sys::path::parent_path(Filename);
117  // Use the current directory if file has no path component.
118  if (DirName.empty())
119  DirName = ".";
120 
121  return FileMgr.getDirectory(DirName, CacheFailure);
122 }
123 
124 /// Add all ancestors of the given path (pointing to either a file or
125 /// a directory) as virtual directories.
126 void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
127  StringRef DirName = llvm::sys::path::parent_path(Path);
128  if (DirName.empty())
129  DirName = ".";
130 
131  auto &NamedDirEnt =
132  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
133 
134  // When caching a virtual directory, we always cache its ancestors
135  // at the same time. Therefore, if DirName is already in the cache,
136  // we don't need to recurse as its ancestors must also already be in
137  // the cache.
138  if (NamedDirEnt.second && NamedDirEnt.second != NON_EXISTENT_DIR)
139  return;
140 
141  // Add the virtual directory to the cache.
142  auto UDE = llvm::make_unique<DirectoryEntry>();
143  UDE->Name = NamedDirEnt.first();
144  NamedDirEnt.second = UDE.get();
145  VirtualDirectoryEntries.push_back(std::move(UDE));
146 
147  // Recursively add the other ancestors.
148  addAncestorsAsVirtualDirs(DirName);
149 }
150 
151 const DirectoryEntry *FileManager::getDirectory(StringRef DirName,
152  bool CacheFailure) {
153  // stat doesn't like trailing separators except for root directory.
154  // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'.
155  // (though it can strip '\\')
156  if (DirName.size() > 1 &&
157  DirName != llvm::sys::path::root_path(DirName) &&
158  llvm::sys::path::is_separator(DirName.back()))
159  DirName = DirName.substr(0, DirName.size()-1);
160 #ifdef _WIN32
161  // Fixing a problem with "clang C:test.c" on Windows.
162  // Stat("C:") does not recognize "C:" as a valid directory
163  std::string DirNameStr;
164  if (DirName.size() > 1 && DirName.back() == ':' &&
165  DirName.equals_lower(llvm::sys::path::root_name(DirName))) {
166  DirNameStr = DirName.str() + '.';
167  DirName = DirNameStr;
168  }
169 #endif
170 
171  ++NumDirLookups;
172  auto &NamedDirEnt =
173  *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;
174 
175  // See if there was already an entry in the map. Note that the map
176  // contains both virtual and real directories.
177  if (NamedDirEnt.second)
178  return NamedDirEnt.second == NON_EXISTENT_DIR ? nullptr
179  : NamedDirEnt.second;
180 
181  ++NumDirCacheMisses;
182 
183  // By default, initialize it to invalid.
184  NamedDirEnt.second = NON_EXISTENT_DIR;
185 
186  // Get the null-terminated directory name as stored as the key of the
187  // SeenDirEntries map.
188  StringRef InterndDirName = NamedDirEnt.first();
189 
190  // Check to see if the directory exists.
191  FileData Data;
192  if (getStatValue(InterndDirName, Data, false, nullptr /*directory lookup*/)) {
193  // There's no real directory at the given path.
194  if (!CacheFailure)
195  SeenDirEntries.erase(DirName);
196  return nullptr;
197  }
198 
199  // It exists. See if we have already opened a directory with the
200  // same inode (this occurs on Unix-like systems when one dir is
201  // symlinked to another, for example) or the same path (on
202  // Windows).
203  DirectoryEntry &UDE = UniqueRealDirs[Data.UniqueID];
204 
205  NamedDirEnt.second = &UDE;
206  if (UDE.getName().empty()) {
207  // We don't have this directory yet, add it. We use the string
208  // key from the SeenDirEntries map as the string.
209  UDE.Name = InterndDirName;
210  }
211 
212  return &UDE;
213 }
214 
215 const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
216  bool CacheFailure) {
217  ++NumFileLookups;
218 
219  // See if there is already an entry in the map.
220  auto &NamedFileEnt =
221  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
222 
223  // See if there is already an entry in the map.
224  if (NamedFileEnt.second) {
225  if (NamedFileEnt.second == NON_EXISTENT_FILE)
226  return nullptr;
227  // Entry exists: return it *unless* it wasn't opened and open is requested.
228  if (!(NamedFileEnt.second->DeferredOpen && openFile))
229  return NamedFileEnt.second;
230  // We previously stat()ed the file, but didn't open it: do that below.
231  // FIXME: the below does other redundant work too (stats the dir and file).
232  } else {
233  // By default, initialize it to invalid.
234  NamedFileEnt.second = NON_EXISTENT_FILE;
235  }
236 
237  ++NumFileCacheMisses;
238 
239  // Get the null-terminated file name as stored as the key of the
240  // SeenFileEntries map.
241  StringRef InterndFileName = NamedFileEnt.first();
242 
243  // Look up the directory for the file. When looking up something like
244  // sys/foo.h we'll discover all of the search directories that have a 'sys'
245  // subdirectory. This will let us avoid having to waste time on known-to-fail
246  // searches when we go to find sys/bar.h, because all the search directories
247  // without a 'sys' subdir will get a cached failure result.
248  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
249  CacheFailure);
250  if (DirInfo == nullptr) { // Directory doesn't exist, file can't exist.
251  if (!CacheFailure)
252  SeenFileEntries.erase(Filename);
253 
254  return nullptr;
255  }
256 
257  // FIXME: Use the directory info to prune this, before doing the stat syscall.
258  // FIXME: This will reduce the # syscalls.
259 
260  // Nope, there isn't. Check to see if the file exists.
261  std::unique_ptr<llvm::vfs::File> F;
262  FileData Data;
263  if (getStatValue(InterndFileName, Data, true, openFile ? &F : nullptr)) {
264  // There's no real file at the given path.
265  if (!CacheFailure)
266  SeenFileEntries.erase(Filename);
267 
268  return nullptr;
269  }
270 
271  assert((openFile || !F) && "undesired open file");
272 
273  // It exists. See if we have already opened a file with the same inode.
274  // This occurs when one dir is symlinked to another, for example.
275  FileEntry &UFE = UniqueRealFiles[Data.UniqueID];
276  UFE.DeferredOpen = !openFile;
277 
278  NamedFileEnt.second = &UFE;
279 
280  // If the name returned by getStatValue is different than Filename, re-intern
281  // the name.
282  if (Data.Name != Filename) {
283  auto &NamedFileEnt =
284  *SeenFileEntries.insert(std::make_pair(Data.Name, nullptr)).first;
285  if (!NamedFileEnt.second)
286  NamedFileEnt.second = &UFE;
287  else
288  assert(NamedFileEnt.second == &UFE &&
289  "filename from getStatValue() refers to wrong file");
290  InterndFileName = NamedFileEnt.first().data();
291  }
292 
293  // If we opened the file for the first time, record the resulting info.
294  // Do this even if the cache entry was valid, maybe we didn't previously open.
295  if (F && !UFE.File) {
296  if (auto PathName = F->getName())
297  fillRealPathName(&UFE, *PathName);
298  UFE.File = std::move(F);
299  assert(!UFE.DeferredOpen && "we just opened it!");
300  }
301 
302  if (UFE.isValid()) { // Already have an entry with this inode, return it.
303 
304  // FIXME: this hack ensures that if we look up a file by a virtual path in
305  // the VFS that the getDir() will have the virtual path, even if we found
306  // the file by a 'real' path first. This is required in order to find a
307  // module's structure when its headers/module map are mapped in the VFS.
308  // We should remove this as soon as we can properly support a file having
309  // multiple names.
310  if (DirInfo != UFE.Dir && Data.IsVFSMapped)
311  UFE.Dir = DirInfo;
312 
313  // Always update the name to use the last name by which a file was accessed.
314  // FIXME: Neither this nor always using the first name is correct; we want
315  // to switch towards a design where we return a FileName object that
316  // encapsulates both the name by which the file was accessed and the
317  // corresponding FileEntry.
318  UFE.Name = InterndFileName;
319 
320  return &UFE;
321  }
322 
323  // Otherwise, we don't have this file yet, add it.
324  UFE.Name = InterndFileName;
325  UFE.Size = Data.Size;
326  UFE.ModTime = Data.ModTime;
327  UFE.Dir = DirInfo;
328  UFE.UID = NextFileUID++;
329  UFE.UniqueID = Data.UniqueID;
330  UFE.IsNamedPipe = Data.IsNamedPipe;
331  UFE.InPCH = Data.InPCH;
332  UFE.IsValid = true;
333  // Note File and DeferredOpen were initialized above.
334 
335  return &UFE;
336 }
337 
338 const FileEntry *
339 FileManager::getVirtualFile(StringRef Filename, off_t Size,
340  time_t ModificationTime) {
341  ++NumFileLookups;
342 
343  // See if there is already an entry in the map.
344  auto &NamedFileEnt =
345  *SeenFileEntries.insert(std::make_pair(Filename, nullptr)).first;
346 
347  // See if there is already an entry in the map.
348  if (NamedFileEnt.second && NamedFileEnt.second != NON_EXISTENT_FILE)
349  return NamedFileEnt.second;
350 
351  ++NumFileCacheMisses;
352 
353  // By default, initialize it to invalid.
354  NamedFileEnt.second = NON_EXISTENT_FILE;
355 
356  addAncestorsAsVirtualDirs(Filename);
357  FileEntry *UFE = nullptr;
358 
359  // Now that all ancestors of Filename are in the cache, the
360  // following call is guaranteed to find the DirectoryEntry from the
361  // cache.
362  const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
363  /*CacheFailure=*/true);
364  assert(DirInfo &&
365  "The directory of a virtual file should already be in the cache.");
366 
367  // Check to see if the file exists. If so, drop the virtual file
368  FileData Data;
369  const char *InterndFileName = NamedFileEnt.first().data();
370  if (getStatValue(InterndFileName, Data, true, nullptr) == 0) {
371  Data.Size = Size;
372  Data.ModTime = ModificationTime;
373  UFE = &UniqueRealFiles[Data.UniqueID];
374 
375  NamedFileEnt.second = UFE;
376 
377  // If we had already opened this file, close it now so we don't
378  // leak the descriptor. We're not going to use the file
379  // descriptor anyway, since this is a virtual file.
380  if (UFE->File)
381  UFE->closeFile();
382 
383  // If we already have an entry with this inode, return it.
384  if (UFE->isValid())
385  return UFE;
386 
387  UFE->UniqueID = Data.UniqueID;
388  UFE->IsNamedPipe = Data.IsNamedPipe;
389  UFE->InPCH = Data.InPCH;
390  fillRealPathName(UFE, Data.Name);
391  }
392 
393  if (!UFE) {
394  VirtualFileEntries.push_back(llvm::make_unique<FileEntry>());
395  UFE = VirtualFileEntries.back().get();
396  NamedFileEnt.second = UFE;
397  }
398 
399  UFE->Name = InterndFileName;
400  UFE->Size = Size;
401  UFE->ModTime = ModificationTime;
402  UFE->Dir = DirInfo;
403  UFE->UID = NextFileUID++;
404  UFE->IsValid = true;
405  UFE->File.reset();
406  UFE->DeferredOpen = false;
407  return UFE;
408 }
409 
411  StringRef pathRef(path.data(), path.size());
412 
413  if (FileSystemOpts.WorkingDir.empty()
414  || llvm::sys::path::is_absolute(pathRef))
415  return false;
416 
417  SmallString<128> NewPath(FileSystemOpts.WorkingDir);
418  llvm::sys::path::append(NewPath, pathRef);
419  path = NewPath;
420  return true;
421 }
422 
424  bool Changed = FixupRelativePath(Path);
425 
426  if (!llvm::sys::path::is_absolute(StringRef(Path.data(), Path.size()))) {
427  FS->makeAbsolute(Path);
428  Changed = true;
429  }
430 
431  return Changed;
432 }
433 
434 void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
435  llvm::SmallString<128> AbsPath(FileName);
436  // This is not the same as `VFS::getRealPath()`, which resolves symlinks
437  // but can be very expensive on real file systems.
438  // FIXME: the semantic of RealPathName is unclear, and the name might be
439  // misleading. We need to clean up the interface here.
440  makeAbsolutePath(AbsPath);
441  llvm::sys::path::remove_dots(AbsPath, /*remove_dot_dot=*/true);
442  UFE->RealPathName = AbsPath.str();
443 }
444 
445 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
446 FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile,
447  bool ShouldCloseOpenFile) {
448  uint64_t FileSize = Entry->getSize();
449  // If there's a high enough chance that the file have changed since we
450  // got its size, force a stat before opening it.
451  if (isVolatile)
452  FileSize = -1;
453 
454  StringRef Filename = Entry->getName();
455  // If the file is already open, use the open file descriptor.
456  if (Entry->File) {
457  auto Result =
458  Entry->File->getBuffer(Filename, FileSize,
459  /*RequiresNullTerminator=*/true, isVolatile);
460  // FIXME: we need a set of APIs that can make guarantees about whether a
461  // FileEntry is open or not.
462  if (ShouldCloseOpenFile)
463  Entry->closeFile();
464  return Result;
465  }
466 
467  // Otherwise, open the file.
468 
469  if (FileSystemOpts.WorkingDir.empty())
470  return FS->getBufferForFile(Filename, FileSize,
471  /*RequiresNullTerminator=*/true, isVolatile);
472 
473  SmallString<128> FilePath(Entry->getName());
474  FixupRelativePath(FilePath);
475  return FS->getBufferForFile(FilePath, FileSize,
476  /*RequiresNullTerminator=*/true, isVolatile);
477 }
478 
479 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
480 FileManager::getBufferForFile(StringRef Filename, bool isVolatile) {
481  if (FileSystemOpts.WorkingDir.empty())
482  return FS->getBufferForFile(Filename, -1, true, isVolatile);
483 
484  SmallString<128> FilePath(Filename);
485  FixupRelativePath(FilePath);
486  return FS->getBufferForFile(FilePath.c_str(), -1, true, isVolatile);
487 }
488 
489 /// getStatValue - Get the 'stat' information for the specified path,
490 /// using the cache to accelerate it if possible. This returns true
491 /// if the path points to a virtual file or does not exist, or returns
492 /// false if it's an existent real file. If FileDescriptor is NULL,
493 /// do directory look-up instead of file look-up.
494 bool FileManager::getStatValue(StringRef Path, FileData &Data, bool isFile,
495  std::unique_ptr<llvm::vfs::File> *F) {
496  // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
497  // absolute!
498  if (FileSystemOpts.WorkingDir.empty())
499  return FileSystemStatCache::get(Path, Data, isFile, F,StatCache.get(), *FS);
500 
501  SmallString<128> FilePath(Path);
502  FixupRelativePath(FilePath);
503 
504  return FileSystemStatCache::get(FilePath.c_str(), Data, isFile, F,
505  StatCache.get(), *FS);
506 }
507 
509  llvm::vfs::Status &Result) {
510  SmallString<128> FilePath(Path);
511  FixupRelativePath(FilePath);
512 
513  llvm::ErrorOr<llvm::vfs::Status> S = FS->status(FilePath.c_str());
514  if (!S)
515  return true;
516  Result = *S;
517  return false;
518 }
519 
521  assert(Entry && "Cannot invalidate a NULL FileEntry");
522 
523  SeenFileEntries.erase(Entry->getName());
524 
525  // FileEntry invalidation should not block future optimizations in the file
526  // caches. Possible alternatives are cache truncation (invalidate last N) or
527  // invalidation of the whole cache.
528  UniqueRealFiles.erase(Entry->getUniqueID());
529 }
530 
532  SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
533  UIDToFiles.clear();
534  UIDToFiles.resize(NextFileUID);
535 
536  // Map file entries
537  for (llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator>::const_iterator
538  FE = SeenFileEntries.begin(), FEEnd = SeenFileEntries.end();
539  FE != FEEnd; ++FE)
540  if (FE->getValue() && FE->getValue() != NON_EXISTENT_FILE)
541  UIDToFiles[FE->getValue()->getUID()] = FE->getValue();
542 
543  // Map virtual file entries
544  for (const auto &VFE : VirtualFileEntries)
545  if (VFE && VFE.get() != NON_EXISTENT_FILE)
546  UIDToFiles[VFE->getUID()] = VFE.get();
547 }
548 
550  off_t Size, time_t ModificationTime) {
551  File->Size = Size;
552  File->ModTime = ModificationTime;
553 }
554 
556  // FIXME: use llvm::sys::fs::canonical() when it gets implemented
557  llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known
558  = CanonicalDirNames.find(Dir);
559  if (Known != CanonicalDirNames.end())
560  return Known->second;
561 
562  StringRef CanonicalName(Dir->getName());
563 
564  SmallString<4096> CanonicalNameBuf;
565  if (!FS->getRealPath(Dir->getName(), CanonicalNameBuf))
566  CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage);
567 
568  CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
569  return CanonicalName;
570 }
571 
573  llvm::errs() << "\n*** File Manager Stats:\n";
574  llvm::errs() << UniqueRealFiles.size() << " real files found, "
575  << UniqueRealDirs.size() << " real dirs found.\n";
576  llvm::errs() << VirtualFileEntries.size() << " virtual files found, "
577  << VirtualDirectoryEntries.size() << " virtual dirs found.\n";
578  llvm::errs() << NumDirLookups << " dir lookups, "
579  << NumDirCacheMisses << " dir cache misses.\n";
580  llvm::errs() << NumFileLookups << " file lookups, "
581  << NumFileCacheMisses << " file cache misses.\n";
582 
583  //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups;
584 }
Implements support for file system lookup, file system caching, and directory search management...
Definition: FileManager.h:122
Defines the clang::FileManager interface and associated types.
void GetUniqueIDMapping(SmallVectorImpl< const FileEntry *> &UIDToFiles) const
Produce an array mapping from the unique IDs assigned to each file to the corresponding FileEntry poi...
void closeFile() const
Definition: FileManager.h:104
Defines the FileSystemStatCache interface.
bool makeAbsolutePath(SmallVectorImpl< char > &Path) const
Makes Path absolute taking into account FileSystemOptions and the working directory option...
const llvm::sys::fs::UniqueID & getUniqueID() const
Definition: FileManager.h:91
#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:41
FileManager(const FileSystemOptions &FileSystemOpts, IntrusiveRefCntPtr< llvm::vfs::FileSystem > FS=nullptr)
Definition: FileManager.cpp:51
Definition: Format.h:2072
#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:45
Abstract interface for introducing a FileManager cache for &#39;stat&#39; 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...
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:1629
bool FixupRelativePath(SmallVectorImpl< char > &path) const
If path is not absolute and FileSystemOptions set the working directory, the path is modified to be r...
static const DirectoryEntry * getDirectoryFromFile(FileManager &FileMgr, StringRef Filename, bool CacheFailure)
Retrieve the directory that the given file name resides in.
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.
static bool get(StringRef Path, FileData &Data, bool isFile, std::unique_ptr< llvm::vfs::File > *F, FileSystemStatCache *Cache, llvm::vfs::FileSystem &FS)
Get the &#39;stat&#39; information for the specified path, using the cache to accelerate it if possible...
void addStatCache(std::unique_ptr< FileSystemStatCache > statCache, bool AtBeginning=false)
Installs the provided FileSystemStatCache object within the FileManager.
Definition: FileManager.cpp:66
llvm::sys::fs::UniqueID UniqueID
StringRef getName() const
Definition: FileManager.h:86
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:60
void clearStatCaches()
Removes all FileSystemStatCache objects from the manager.
void PrintStats() const
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...
StringRef getCanonicalName(const DirectoryEntry *Dir)
Retrieve the canonical name for a given directory.
bool isValid() const
Definition: FileManager.h:88
Dataflow Directional Tag Classes.
off_t getSize() const
Definition: FileManager.h:89
void removeStatCache(FileSystemStatCache *statCache)
Removes the specified FileSystemStatCache object from the manager.
Definition: FileManager.cpp:82
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.
bool getNoncachedStatValue(StringRef Path, llvm::vfs::Status &Result)
Get the &#39;stat&#39; information for the given Path.
Cached information about one directory (either on disk or in the virtual file system).
Definition: FileManager.h:46
Keeps track of options that affect how file operations are performed.
static void modifyFileEntry(FileEntry *File, off_t Size, time_t ModificationTime)
Modifies the size and modification time of a previously created FileEntry.
void invalidateCache(const FileEntry *Entry)
Remove the real file Entry from the cache.
FileSystemStatCache * getNextStatCache()
Retrieve the next stat call cache in the chain.
StringRef getName() const
Definition: FileManager.h:52