1 //===--- FileManager.cpp - File System Probing and Caching ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the FileManager interface.
12 //===----------------------------------------------------------------------===//
14 // TODO: This should index all interesting directories with dirent calls.
16 // opendir/readdir_r/closedir ?
18 //===----------------------------------------------------------------------===//
20 #include "clang/Basic/FileManager.h"
21 #include "clang/Basic/FileSystemStatCache.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/Config/llvm-config.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/Path.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include "llvm/Support/system_error.h"
33 // FIXME: This is terrible, we need this for ::close.
34 #if !defined(_MSC_VER) && !defined(__MINGW32__)
40 #define S_ISFIFO(x) (0)
43 #if defined(LLVM_ON_UNIX)
46 using namespace clang;
48 // FIXME: Enhance libsystem to support inode and other fields.
51 /// NON_EXISTENT_DIR - A special value distinct from null that is used to
52 /// represent a dir name that doesn't exist on the disk.
53 #define NON_EXISTENT_DIR reinterpret_cast<DirectoryEntry*>((intptr_t)-1)
55 /// NON_EXISTENT_FILE - A special value distinct from null that is used to
56 /// represent a filename that doesn't exist on the disk.
57 #define NON_EXISTENT_FILE reinterpret_cast<FileEntry*>((intptr_t)-1)
60 FileEntry::~FileEntry() {
61 // If this FileEntry owns an open file descriptor that never got used, close
63 if (FD != -1) ::close(FD);
66 class FileManager::UniqueDirContainer {
67 /// UniqueDirs - Cache from ID's to existing directories/files.
68 std::map<llvm::sys::fs::UniqueID, DirectoryEntry> UniqueDirs;
71 /// getDirectory - Return an existing DirectoryEntry with the given
72 /// ID's if there is already one; otherwise create and return a
73 /// default-constructed DirectoryEntry.
74 DirectoryEntry &getDirectory(const llvm::sys::fs::UniqueID &UniqueID) {
75 return UniqueDirs[UniqueID];
78 size_t size() const { return UniqueDirs.size(); }
81 class FileManager::UniqueFileContainer {
82 /// UniqueFiles - Cache from ID's to existing directories/files.
83 std::set<FileEntry> UniqueFiles;
86 /// getFile - Return an existing FileEntry with the given ID's if
87 /// there is already one; otherwise create and return a
88 /// default-constructed FileEntry.
89 FileEntry &getFile(llvm::sys::fs::UniqueID UniqueID, bool IsNamedPipe,
91 return const_cast<FileEntry &>(
92 *UniqueFiles.insert(FileEntry(UniqueID, IsNamedPipe, InPCH)).first);
95 size_t size() const { return UniqueFiles.size(); }
97 void erase(const FileEntry *Entry) { UniqueFiles.erase(*Entry); }
100 //===----------------------------------------------------------------------===//
102 //===----------------------------------------------------------------------===//
104 FileManager::FileManager(const FileSystemOptions &FSO)
105 : FileSystemOpts(FSO),
106 UniqueRealDirs(*new UniqueDirContainer()),
107 UniqueRealFiles(*new UniqueFileContainer()),
108 SeenDirEntries(64), SeenFileEntries(64), NextFileUID(0) {
109 NumDirLookups = NumFileLookups = 0;
110 NumDirCacheMisses = NumFileCacheMisses = 0;
113 FileManager::~FileManager() {
114 delete &UniqueRealDirs;
115 delete &UniqueRealFiles;
116 for (unsigned i = 0, e = VirtualFileEntries.size(); i != e; ++i)
117 delete VirtualFileEntries[i];
118 for (unsigned i = 0, e = VirtualDirectoryEntries.size(); i != e; ++i)
119 delete VirtualDirectoryEntries[i];
122 void FileManager::addStatCache(FileSystemStatCache *statCache,
124 assert(statCache && "No stat cache provided?");
125 if (AtBeginning || StatCache.get() == 0) {
126 statCache->setNextStatCache(StatCache.take());
127 StatCache.reset(statCache);
131 FileSystemStatCache *LastCache = StatCache.get();
132 while (LastCache->getNextStatCache())
133 LastCache = LastCache->getNextStatCache();
135 LastCache->setNextStatCache(statCache);
138 void FileManager::removeStatCache(FileSystemStatCache *statCache) {
142 if (StatCache.get() == statCache) {
143 // This is the first stat cache.
144 StatCache.reset(StatCache->takeNextStatCache());
148 // Find the stat cache in the list.
149 FileSystemStatCache *PrevCache = StatCache.get();
150 while (PrevCache && PrevCache->getNextStatCache() != statCache)
151 PrevCache = PrevCache->getNextStatCache();
153 assert(PrevCache && "Stat cache not found for removal");
154 PrevCache->setNextStatCache(statCache->getNextStatCache());
157 void FileManager::clearStatCaches() {
161 /// \brief Retrieve the directory that the given file name resides in.
162 /// Filename can point to either a real file or a virtual file.
163 static const DirectoryEntry *getDirectoryFromFile(FileManager &FileMgr,
166 if (Filename.empty())
169 if (llvm::sys::path::is_separator(Filename[Filename.size() - 1]))
170 return NULL; // If Filename is a directory.
172 StringRef DirName = llvm::sys::path::parent_path(Filename);
173 // Use the current directory if file has no path component.
177 return FileMgr.getDirectory(DirName, CacheFailure);
180 /// Add all ancestors of the given path (pointing to either a file or
181 /// a directory) as virtual directories.
182 void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
183 StringRef DirName = llvm::sys::path::parent_path(Path);
187 llvm::StringMapEntry<DirectoryEntry *> &NamedDirEnt =
188 SeenDirEntries.GetOrCreateValue(DirName);
190 // When caching a virtual directory, we always cache its ancestors
191 // at the same time. Therefore, if DirName is already in the cache,
192 // we don't need to recurse as its ancestors must also already be in
194 if (NamedDirEnt.getValue())
197 // Add the virtual directory to the cache.
198 DirectoryEntry *UDE = new DirectoryEntry;
199 UDE->Name = NamedDirEnt.getKeyData();
200 NamedDirEnt.setValue(UDE);
201 VirtualDirectoryEntries.push_back(UDE);
203 // Recursively add the other ancestors.
204 addAncestorsAsVirtualDirs(DirName);
207 const DirectoryEntry *FileManager::getDirectory(StringRef DirName,
209 // stat doesn't like trailing separators except for root directory.
210 // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'.
211 // (though it can strip '\\')
212 if (DirName.size() > 1 &&
213 DirName != llvm::sys::path::root_path(DirName) &&
214 llvm::sys::path::is_separator(DirName.back()))
215 DirName = DirName.substr(0, DirName.size()-1);
217 // Fixing a problem with "clang C:test.c" on Windows.
218 // Stat("C:") does not recognize "C:" as a valid directory
219 std::string DirNameStr;
220 if (DirName.size() > 1 && DirName.back() == ':' &&
221 DirName.equals_lower(llvm::sys::path::root_name(DirName))) {
222 DirNameStr = DirName.str() + '.';
223 DirName = DirNameStr;
228 llvm::StringMapEntry<DirectoryEntry *> &NamedDirEnt =
229 SeenDirEntries.GetOrCreateValue(DirName);
231 // See if there was already an entry in the map. Note that the map
232 // contains both virtual and real directories.
233 if (NamedDirEnt.getValue())
234 return NamedDirEnt.getValue() == NON_EXISTENT_DIR
235 ? 0 : NamedDirEnt.getValue();
239 // By default, initialize it to invalid.
240 NamedDirEnt.setValue(NON_EXISTENT_DIR);
242 // Get the null-terminated directory name as stored as the key of the
243 // SeenDirEntries map.
244 const char *InterndDirName = NamedDirEnt.getKeyData();
246 // Check to see if the directory exists.
248 if (getStatValue(InterndDirName, Data, false, 0 /*directory lookup*/)) {
249 // There's no real directory at the given path.
251 SeenDirEntries.erase(DirName);
255 // It exists. See if we have already opened a directory with the
256 // same inode (this occurs on Unix-like systems when one dir is
257 // symlinked to another, for example) or the same path (on
259 DirectoryEntry &UDE =
260 UniqueRealDirs.getDirectory(Data.UniqueID);
262 NamedDirEnt.setValue(&UDE);
263 if (!UDE.getName()) {
264 // We don't have this directory yet, add it. We use the string
265 // key from the SeenDirEntries map as the string.
266 UDE.Name = InterndDirName;
272 const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
276 // See if there is already an entry in the map.
277 llvm::StringMapEntry<FileEntry *> &NamedFileEnt =
278 SeenFileEntries.GetOrCreateValue(Filename);
280 // See if there is already an entry in the map.
281 if (NamedFileEnt.getValue())
282 return NamedFileEnt.getValue() == NON_EXISTENT_FILE
283 ? 0 : NamedFileEnt.getValue();
285 ++NumFileCacheMisses;
287 // By default, initialize it to invalid.
288 NamedFileEnt.setValue(NON_EXISTENT_FILE);
290 // Get the null-terminated file name as stored as the key of the
291 // SeenFileEntries map.
292 const char *InterndFileName = NamedFileEnt.getKeyData();
294 // Look up the directory for the file. When looking up something like
295 // sys/foo.h we'll discover all of the search directories that have a 'sys'
296 // subdirectory. This will let us avoid having to waste time on known-to-fail
297 // searches when we go to find sys/bar.h, because all the search directories
298 // without a 'sys' subdir will get a cached failure result.
299 const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
301 if (DirInfo == 0) { // Directory doesn't exist, file can't exist.
303 SeenFileEntries.erase(Filename);
308 // FIXME: Use the directory info to prune this, before doing the stat syscall.
309 // FIXME: This will reduce the # syscalls.
311 // Nope, there isn't. Check to see if the file exists.
312 int FileDescriptor = -1;
314 if (getStatValue(InterndFileName, Data, true,
315 openFile ? &FileDescriptor : 0)) {
316 // There's no real file at the given path.
318 SeenFileEntries.erase(Filename);
323 if (FileDescriptor != -1 && !openFile) {
324 close(FileDescriptor);
328 // It exists. See if we have already opened a file with the same inode.
329 // This occurs when one dir is symlinked to another, for example.
331 UniqueRealFiles.getFile(Data.UniqueID, Data.IsNamedPipe, Data.InPCH);
333 NamedFileEnt.setValue(&UFE);
334 if (UFE.getName()) { // Already have an entry with this inode, return it.
335 // If the stat process opened the file, close it to avoid a FD leak.
336 if (FileDescriptor != -1)
337 close(FileDescriptor);
342 // Otherwise, we don't have this directory yet, add it.
343 // FIXME: Change the name to be a char* that points back to the
344 // 'SeenFileEntries' key.
345 UFE.Name = InterndFileName;
346 UFE.Size = Data.Size;
347 UFE.ModTime = Data.ModTime;
349 UFE.UID = NextFileUID++;
350 UFE.FD = FileDescriptor;
355 FileManager::getVirtualFile(StringRef Filename, off_t Size,
356 time_t ModificationTime) {
359 // See if there is already an entry in the map.
360 llvm::StringMapEntry<FileEntry *> &NamedFileEnt =
361 SeenFileEntries.GetOrCreateValue(Filename);
363 // See if there is already an entry in the map.
364 if (NamedFileEnt.getValue() && NamedFileEnt.getValue() != NON_EXISTENT_FILE)
365 return NamedFileEnt.getValue();
367 ++NumFileCacheMisses;
369 // By default, initialize it to invalid.
370 NamedFileEnt.setValue(NON_EXISTENT_FILE);
372 addAncestorsAsVirtualDirs(Filename);
375 // Now that all ancestors of Filename are in the cache, the
376 // following call is guaranteed to find the DirectoryEntry from the
378 const DirectoryEntry *DirInfo = getDirectoryFromFile(*this, Filename,
379 /*CacheFailure=*/true);
381 "The directory of a virtual file should already be in the cache.");
383 // Check to see if the file exists. If so, drop the virtual file
385 const char *InterndFileName = NamedFileEnt.getKeyData();
386 if (getStatValue(InterndFileName, Data, true, 0) == 0) {
388 Data.ModTime = ModificationTime;
389 UFE = &UniqueRealFiles.getFile(Data.UniqueID, Data.IsNamedPipe, Data.InPCH);
391 NamedFileEnt.setValue(UFE);
393 // If we had already opened this file, close it now so we don't
394 // leak the descriptor. We're not going to use the file
395 // descriptor anyway, since this is a virtual file.
401 // If we already have an entry with this inode, return it.
407 UFE = new FileEntry();
408 VirtualFileEntries.push_back(UFE);
409 NamedFileEnt.setValue(UFE);
412 UFE->Name = InterndFileName;
414 UFE->ModTime = ModificationTime;
416 UFE->UID = NextFileUID++;
421 void FileManager::FixupRelativePath(SmallVectorImpl<char> &path) const {
422 StringRef pathRef(path.data(), path.size());
424 if (FileSystemOpts.WorkingDir.empty()
425 || llvm::sys::path::is_absolute(pathRef))
428 SmallString<128> NewPath(FileSystemOpts.WorkingDir);
429 llvm::sys::path::append(NewPath, pathRef);
433 llvm::MemoryBuffer *FileManager::
434 getBufferForFile(const FileEntry *Entry, std::string *ErrorStr,
436 OwningPtr<llvm::MemoryBuffer> Result;
439 uint64_t FileSize = Entry->getSize();
440 // If there's a high enough chance that the file have changed since we
441 // got its size, force a stat before opening it.
445 const char *Filename = Entry->getName();
446 // If the file is already open, use the open file descriptor.
447 if (Entry->FD != -1) {
448 ec = llvm::MemoryBuffer::getOpenFile(Entry->FD, Filename, Result, FileSize);
450 *ErrorStr = ec.message();
454 return Result.take();
457 // Otherwise, open the file.
459 if (FileSystemOpts.WorkingDir.empty()) {
460 ec = llvm::MemoryBuffer::getFile(Filename, Result, FileSize);
462 *ErrorStr = ec.message();
463 return Result.take();
466 SmallString<128> FilePath(Entry->getName());
467 FixupRelativePath(FilePath);
468 ec = llvm::MemoryBuffer::getFile(FilePath.str(), Result, FileSize);
470 *ErrorStr = ec.message();
471 return Result.take();
474 llvm::MemoryBuffer *FileManager::
475 getBufferForFile(StringRef Filename, std::string *ErrorStr) {
476 OwningPtr<llvm::MemoryBuffer> Result;
478 if (FileSystemOpts.WorkingDir.empty()) {
479 ec = llvm::MemoryBuffer::getFile(Filename, Result);
481 *ErrorStr = ec.message();
482 return Result.take();
485 SmallString<128> FilePath(Filename);
486 FixupRelativePath(FilePath);
487 ec = llvm::MemoryBuffer::getFile(FilePath.c_str(), Result);
489 *ErrorStr = ec.message();
490 return Result.take();
493 /// getStatValue - Get the 'stat' information for the specified path,
494 /// using the cache to accelerate it if possible. This returns true
495 /// if the path points to a virtual file or does not exist, or returns
496 /// false if it's an existent real file. If FileDescriptor is NULL,
497 /// do directory look-up instead of file look-up.
498 bool FileManager::getStatValue(const char *Path, FileData &Data, bool isFile,
499 int *FileDescriptor) {
500 // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
502 if (FileSystemOpts.WorkingDir.empty())
503 return FileSystemStatCache::get(Path, Data, isFile, FileDescriptor,
506 SmallString<128> FilePath(Path);
507 FixupRelativePath(FilePath);
509 return FileSystemStatCache::get(FilePath.c_str(), Data, isFile,
510 FileDescriptor, StatCache.get());
513 bool FileManager::getNoncachedStatValue(StringRef Path,
514 llvm::sys::fs::file_status &Result) {
515 SmallString<128> FilePath(Path);
516 FixupRelativePath(FilePath);
518 return llvm::sys::fs::status(FilePath.c_str(), Result);
521 void FileManager::invalidateCache(const FileEntry *Entry) {
522 assert(Entry && "Cannot invalidate a NULL FileEntry");
524 SeenFileEntries.erase(Entry->getName());
526 // FileEntry invalidation should not block future optimizations in the file
527 // caches. Possible alternatives are cache truncation (invalidate last N) or
528 // invalidation of the whole cache.
529 UniqueRealFiles.erase(Entry);
533 void FileManager::GetUniqueIDMapping(
534 SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
536 UIDToFiles.resize(NextFileUID);
539 for (llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator>::const_iterator
540 FE = SeenFileEntries.begin(), FEEnd = SeenFileEntries.end();
542 if (FE->getValue() && FE->getValue() != NON_EXISTENT_FILE)
543 UIDToFiles[FE->getValue()->getUID()] = FE->getValue();
545 // Map virtual file entries
546 for (SmallVectorImpl<FileEntry *>::const_iterator
547 VFE = VirtualFileEntries.begin(), VFEEnd = VirtualFileEntries.end();
548 VFE != VFEEnd; ++VFE)
549 if (*VFE && *VFE != NON_EXISTENT_FILE)
550 UIDToFiles[(*VFE)->getUID()] = *VFE;
553 void FileManager::modifyFileEntry(FileEntry *File,
554 off_t Size, time_t ModificationTime) {
556 File->ModTime = ModificationTime;
559 StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) {
560 // FIXME: use llvm::sys::fs::canonical() when it gets implemented
562 llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known
563 = CanonicalDirNames.find(Dir);
564 if (Known != CanonicalDirNames.end())
565 return Known->second;
567 StringRef CanonicalName(Dir->getName());
568 char CanonicalNameBuf[PATH_MAX];
569 if (realpath(Dir->getName(), CanonicalNameBuf)) {
570 unsigned Len = strlen(CanonicalNameBuf);
571 char *Mem = static_cast<char *>(CanonicalNameStorage.Allocate(Len, 1));
572 memcpy(Mem, CanonicalNameBuf, Len);
573 CanonicalName = StringRef(Mem, Len);
576 CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
577 return CanonicalName;
579 return StringRef(Dir->getName());
583 void FileManager::PrintStats() const {
584 llvm::errs() << "\n*** File Manager Stats:\n";
585 llvm::errs() << UniqueRealFiles.size() << " real files found, "
586 << UniqueRealDirs.size() << " real dirs found.\n";
587 llvm::errs() << VirtualFileEntries.size() << " virtual files found, "
588 << VirtualDirectoryEntries.size() << " virtual dirs found.\n";
589 llvm::errs() << NumDirLookups << " dir lookups, "
590 << NumDirCacheMisses << " dir cache misses.\n";
591 llvm::errs() << NumFileLookups << " file lookups, "
592 << NumFileCacheMisses << " file cache misses.\n";
594 //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups;