1//===--- FileManager.cpp - File System Probing and Caching ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the FileManager interface.
10//
11//===----------------------------------------------------------------------===//
12//
13// TODO: This should index all interesting directories with dirent calls.
14// getdirentries ?
15// opendir/readdir_r/closedir ?
16//
17//===----------------------------------------------------------------------===//
18
19#include "clang/Basic/FileManager.h"
20#include "clang/Basic/FileSystemStatCache.h"
21#include "llvm/ADT/STLExtras.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/Statistic.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 <algorithm>
30#include <cassert>
31#include <climits>
32#include <cstdint>
33#include <cstdlib>
34#include <optional>
35#include <string>
36#include <utility>
37
38using namespace clang;
39
40#define DEBUG_TYPE "file-search"
41
42//===----------------------------------------------------------------------===//
43// Common logic.
44//===----------------------------------------------------------------------===//
45
46FileManager::FileManager(const FileSystemOptions &FSO,
47 IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS)
48 : FS(std::move(FS)), FileSystemOpts(FSO), SeenDirEntries(64),
49 SeenFileEntries(64), NextFileUID(0) {
50 // If the caller doesn't provide a virtual file system, just grab the real
51 // file system.
52 if (!this->FS)
53 this->FS = llvm::vfs::getRealFileSystem();
54}
55
56FileManager::~FileManager() = default;
57
58void FileManager::setStatCache(std::unique_ptr<FileSystemStatCache> statCache) {
59 assert(statCache && "No stat cache provided?");
60 StatCache = std::move(statCache);
61}
62
63void FileManager::clearStatCache() { StatCache.reset(); }
64
65/// Retrieve the directory that the given file name resides in.
66/// Filename can point to either a real file or a virtual file.
67static llvm::Expected<DirectoryEntryRef>
68getDirectoryFromFile(FileManager &FileMgr, StringRef Filename,
69 bool CacheFailure) {
70 if (Filename.empty())
71 return llvm::errorCodeToError(
72 EC: make_error_code(e: std::errc::no_such_file_or_directory));
73
74 if (llvm::sys::path::is_separator(value: Filename[Filename.size() - 1]))
75 return llvm::errorCodeToError(EC: make_error_code(e: std::errc::is_a_directory));
76
77 StringRef DirName = llvm::sys::path::parent_path(path: Filename);
78 // Use the current directory if file has no path component.
79 if (DirName.empty())
80 DirName = ".";
81
82 return FileMgr.getDirectoryRef(DirName, CacheFailure);
83}
84
85DirectoryEntry *&FileManager::getRealDirEntry(const llvm::vfs::Status &Status) {
86 assert(Status.isDirectory() && "The directory should exist!");
87 // See if we have already opened a directory with the
88 // same inode (this occurs on Unix-like systems when one dir is
89 // symlinked to another, for example) or the same path (on
90 // Windows).
91 DirectoryEntry *&UDE = UniqueRealDirs[Status.getUniqueID()];
92
93 if (!UDE) {
94 // We don't have this directory yet, add it. We use the string
95 // key from the SeenDirEntries map as the string.
96 UDE = new (DirsAlloc.Allocate()) DirectoryEntry();
97 }
98 return UDE;
99}
100
101/// Add all ancestors of the given path (pointing to either a file or
102/// a directory) as virtual directories.
103void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
104 StringRef DirName = llvm::sys::path::parent_path(path: Path);
105 if (DirName.empty())
106 DirName = ".";
107
108 auto &NamedDirEnt = *SeenDirEntries.insert(
109 KV: {DirName, std::errc::no_such_file_or_directory}).first;
110
111 // When caching a virtual directory, we always cache its ancestors
112 // at the same time. Therefore, if DirName is already in the cache,
113 // we don't need to recurse as its ancestors must also already be in
114 // the cache (or it's a known non-virtual directory).
115 if (NamedDirEnt.second)
116 return;
117
118 // Check to see if the directory exists.
119 llvm::vfs::Status Status;
120 auto statError =
121 getStatValue(Path: DirName, Status, isFile: false, F: nullptr /*directory lookup*/);
122 if (statError) {
123 // There's no real directory at the given path.
124 // Add the virtual directory to the cache.
125 auto *UDE = new (DirsAlloc.Allocate()) DirectoryEntry();
126 NamedDirEnt.second = *UDE;
127 VirtualDirectoryEntries.push_back(Elt: UDE);
128 } else {
129 // There is the real directory
130 DirectoryEntry *&UDE = getRealDirEntry(Status);
131 NamedDirEnt.second = *UDE;
132 }
133
134 // Recursively add the other ancestors.
135 addAncestorsAsVirtualDirs(Path: DirName);
136}
137
138llvm::Expected<DirectoryEntryRef>
139FileManager::getDirectoryRef(StringRef DirName, bool CacheFailure) {
140 // stat doesn't like trailing separators except for root directory.
141 // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'.
142 // (though it can strip '\\')
143 if (DirName.size() > 1 &&
144 DirName != llvm::sys::path::root_path(path: DirName) &&
145 llvm::sys::path::is_separator(value: DirName.back()))
146 DirName = DirName.substr(Start: 0, N: DirName.size()-1);
147 std::optional<std::string> DirNameStr;
148 if (is_style_windows(S: llvm::sys::path::Style::native)) {
149 // Fixing a problem with "clang C:test.c" on Windows.
150 // Stat("C:") does not recognize "C:" as a valid directory
151 if (DirName.size() > 1 && DirName.back() == ':' &&
152 DirName.equals_insensitive(RHS: llvm::sys::path::root_name(path: DirName))) {
153 DirNameStr = DirName.str() + '.';
154 DirName = *DirNameStr;
155 }
156 }
157
158 ++NumDirLookups;
159
160 // See if there was already an entry in the map. Note that the map
161 // contains both virtual and real directories.
162 auto SeenDirInsertResult =
163 SeenDirEntries.insert(KV: {DirName, std::errc::no_such_file_or_directory});
164 if (!SeenDirInsertResult.second) {
165 if (SeenDirInsertResult.first->second)
166 return DirectoryEntryRef(*SeenDirInsertResult.first);
167 return llvm::errorCodeToError(EC: SeenDirInsertResult.first->second.getError());
168 }
169
170 // We've not seen this before. Fill it in.
171 ++NumDirCacheMisses;
172 auto &NamedDirEnt = *SeenDirInsertResult.first;
173 assert(!NamedDirEnt.second && "should be newly-created");
174
175 // Get the null-terminated directory name as stored as the key of the
176 // SeenDirEntries map.
177 StringRef InterndDirName = NamedDirEnt.first();
178
179 // Check to see if the directory exists.
180 llvm::vfs::Status Status;
181 auto statError = getStatValue(Path: InterndDirName, Status, isFile: false,
182 F: nullptr /*directory lookup*/);
183 if (statError) {
184 // There's no real directory at the given path.
185 if (CacheFailure)
186 NamedDirEnt.second = statError;
187 else
188 SeenDirEntries.erase(Key: DirName);
189 return llvm::errorCodeToError(EC: statError);
190 }
191
192 // It exists.
193 DirectoryEntry *&UDE = getRealDirEntry(Status);
194 NamedDirEnt.second = *UDE;
195
196 return DirectoryEntryRef(NamedDirEnt);
197}
198
199llvm::ErrorOr<const DirectoryEntry *>
200FileManager::getDirectory(StringRef DirName, bool CacheFailure) {
201 auto Result = getDirectoryRef(DirName, CacheFailure);
202 if (Result)
203 return &Result->getDirEntry();
204 return llvm::errorToErrorCode(Err: Result.takeError());
205}
206
207llvm::ErrorOr<const FileEntry *>
208FileManager::getFile(StringRef Filename, bool openFile, bool CacheFailure) {
209 auto Result = getFileRef(Filename, OpenFile: openFile, CacheFailure);
210 if (Result)
211 return &Result->getFileEntry();
212 return llvm::errorToErrorCode(Err: Result.takeError());
213}
214
215llvm::Expected<FileEntryRef>
216FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) {
217 ++NumFileLookups;
218
219 // See if there is already an entry in the map.
220 auto SeenFileInsertResult =
221 SeenFileEntries.insert(KV: {Filename, std::errc::no_such_file_or_directory});
222 if (!SeenFileInsertResult.second) {
223 if (!SeenFileInsertResult.first->second)
224 return llvm::errorCodeToError(
225 EC: SeenFileInsertResult.first->second.getError());
226 return FileEntryRef(*SeenFileInsertResult.first);
227 }
228
229 // We've not seen this before. Fill it in.
230 ++NumFileCacheMisses;
231 auto *NamedFileEnt = &*SeenFileInsertResult.first;
232 assert(!NamedFileEnt->second && "should be newly-created");
233
234 // Get the null-terminated file name as stored as the key of the
235 // SeenFileEntries map.
236 StringRef InterndFileName = NamedFileEnt->first();
237
238 // Look up the directory for the file. When looking up something like
239 // sys/foo.h we'll discover all of the search directories that have a 'sys'
240 // subdirectory. This will let us avoid having to waste time on known-to-fail
241 // searches when we go to find sys/bar.h, because all the search directories
242 // without a 'sys' subdir will get a cached failure result.
243 auto DirInfoOrErr = getDirectoryFromFile(FileMgr&: *this, Filename, CacheFailure);
244 if (!DirInfoOrErr) { // Directory doesn't exist, file can't exist.
245 std::error_code Err = errorToErrorCode(Err: DirInfoOrErr.takeError());
246 if (CacheFailure)
247 NamedFileEnt->second = Err;
248 else
249 SeenFileEntries.erase(Key: Filename);
250
251 return llvm::errorCodeToError(EC: Err);
252 }
253 DirectoryEntryRef DirInfo = *DirInfoOrErr;
254
255 // FIXME: Use the directory info to prune this, before doing the stat syscall.
256 // FIXME: This will reduce the # syscalls.
257
258 // Check to see if the file exists.
259 std::unique_ptr<llvm::vfs::File> F;
260 llvm::vfs::Status Status;
261 auto statError = getStatValue(Path: InterndFileName, Status, isFile: true,
262 F: openFile ? &F : nullptr);
263 if (statError) {
264 // There's no real file at the given path.
265 if (CacheFailure)
266 NamedFileEnt->second = statError;
267 else
268 SeenFileEntries.erase(Key: Filename);
269
270 return llvm::errorCodeToError(EC: statError);
271 }
272
273 assert((openFile || !F) && "undesired open file");
274
275 // It exists. See if we have already opened a file with the same inode.
276 // This occurs when one dir is symlinked to another, for example.
277 FileEntry *&UFE = UniqueRealFiles[Status.getUniqueID()];
278 bool ReusingEntry = UFE != nullptr;
279 if (!UFE)
280 UFE = new (FilesAlloc.Allocate()) FileEntry();
281
282 if (!Status.ExposesExternalVFSPath || Status.getName() == Filename) {
283 // Use the requested name. Set the FileEntry.
284 NamedFileEnt->second = FileEntryRef::MapValue(*UFE, DirInfo);
285 } else {
286 // Name mismatch. We need a redirect. First grab the actual entry we want
287 // to return.
288 //
289 // This redirection logic intentionally leaks the external name of a
290 // redirected file that uses 'use-external-name' in \a
291 // vfs::RedirectionFileSystem. This allows clang to report the external
292 // name to users (in diagnostics) and to tools that don't have access to
293 // the VFS (in debug info and dependency '.d' files).
294 //
295 // FIXME: This is pretty complex and has some very complicated interactions
296 // with the rest of clang. It's also inconsistent with how "real"
297 // filesystems behave and confuses parts of clang expect to see the
298 // name-as-accessed on the \a FileEntryRef.
299 //
300 // A potential plan to remove this is as follows -
301 // - Update callers such as `HeaderSearch::findUsableModuleForHeader()`
302 // to explicitly use the `getNameAsRequested()` rather than just using
303 // `getName()`.
304 // - Add a `FileManager::getExternalPath` API for explicitly getting the
305 // remapped external filename when there is one available. Adopt it in
306 // callers like diagnostics/deps reporting instead of calling
307 // `getName()` directly.
308 // - Switch the meaning of `FileEntryRef::getName()` to get the requested
309 // name, not the external name. Once that sticks, revert callers that
310 // want the requested name back to calling `getName()`.
311 // - Update the VFS to always return the requested name. This could also
312 // return the external name, or just have an API to request it
313 // lazily. The latter has the benefit of making accesses of the
314 // external path easily tracked, but may also require extra work than
315 // just returning up front.
316 // - (Optionally) Add an API to VFS to get the external filename lazily
317 // and update `FileManager::getExternalPath()` to use it instead. This
318 // has the benefit of making such accesses easily tracked, though isn't
319 // necessarily required (and could cause extra work than just adding to
320 // eg. `vfs::Status` up front).
321 auto &Redirection =
322 *SeenFileEntries
323 .insert(KV: {Status.getName(), FileEntryRef::MapValue(*UFE, DirInfo)})
324 .first;
325 assert(Redirection.second->V.is<FileEntry *>() &&
326 "filename redirected to a non-canonical filename?");
327 assert(Redirection.second->V.get<FileEntry *>() == UFE &&
328 "filename from getStatValue() refers to wrong file");
329
330 // Cache the redirection in the previously-inserted entry, still available
331 // in the tentative return value.
332 NamedFileEnt->second = FileEntryRef::MapValue(Redirection, DirInfo);
333 }
334
335 FileEntryRef ReturnedRef(*NamedFileEnt);
336 if (ReusingEntry) { // Already have an entry with this inode, return it.
337 return ReturnedRef;
338 }
339
340 // Otherwise, we don't have this file yet, add it.
341 UFE->Size = Status.getSize();
342 UFE->ModTime = llvm::sys::toTimeT(TP: Status.getLastModificationTime());
343 UFE->Dir = &DirInfo.getDirEntry();
344 UFE->UID = NextFileUID++;
345 UFE->UniqueID = Status.getUniqueID();
346 UFE->IsNamedPipe = Status.getType() == llvm::sys::fs::file_type::fifo_file;
347 UFE->File = std::move(F);
348
349 if (UFE->File) {
350 if (auto PathName = UFE->File->getName())
351 fillRealPathName(UFE, FileName: *PathName);
352 } else if (!openFile) {
353 // We should still fill the path even if we aren't opening the file.
354 fillRealPathName(UFE, FileName: InterndFileName);
355 }
356 return ReturnedRef;
357}
358
359llvm::Expected<FileEntryRef> FileManager::getSTDIN() {
360 // Only read stdin once.
361 if (STDIN)
362 return *STDIN;
363
364 std::unique_ptr<llvm::MemoryBuffer> Content;
365 if (auto ContentOrError = llvm::MemoryBuffer::getSTDIN())
366 Content = std::move(*ContentOrError);
367 else
368 return llvm::errorCodeToError(EC: ContentOrError.getError());
369
370 STDIN = getVirtualFileRef(Filename: Content->getBufferIdentifier(),
371 Size: Content->getBufferSize(), ModificationTime: 0);
372 FileEntry &FE = const_cast<FileEntry &>(STDIN->getFileEntry());
373 FE.Content = std::move(Content);
374 FE.IsNamedPipe = true;
375 return *STDIN;
376}
377
378void FileManager::trackVFSUsage(bool Active) {
379 FS->visit(Callback: [Active](llvm::vfs::FileSystem &FileSys) {
380 if (auto *RFS = dyn_cast<llvm::vfs::RedirectingFileSystem>(Val: &FileSys))
381 RFS->setUsageTrackingActive(Active);
382 });
383}
384
385const FileEntry *FileManager::getVirtualFile(StringRef Filename, off_t Size,
386 time_t ModificationTime) {
387 return &getVirtualFileRef(Filename, Size, ModificationTime).getFileEntry();
388}
389
390FileEntryRef FileManager::getVirtualFileRef(StringRef Filename, off_t Size,
391 time_t ModificationTime) {
392 ++NumFileLookups;
393
394 // See if there is already an entry in the map for an existing file.
395 auto &NamedFileEnt = *SeenFileEntries.insert(
396 KV: {Filename, std::errc::no_such_file_or_directory}).first;
397 if (NamedFileEnt.second) {
398 FileEntryRef::MapValue Value = *NamedFileEnt.second;
399 if (LLVM_LIKELY(Value.V.is<FileEntry *>()))
400 return FileEntryRef(NamedFileEnt);
401 return FileEntryRef(*Value.V.get<const FileEntryRef::MapEntry *>());
402 }
403
404 // We've not seen this before, or the file is cached as non-existent.
405 ++NumFileCacheMisses;
406 addAncestorsAsVirtualDirs(Path: Filename);
407 FileEntry *UFE = nullptr;
408
409 // Now that all ancestors of Filename are in the cache, the
410 // following call is guaranteed to find the DirectoryEntry from the
411 // cache. A virtual file can also have an empty filename, that could come
412 // from a source location preprocessor directive with an empty filename as
413 // an example, so we need to pretend it has a name to ensure a valid directory
414 // entry can be returned.
415 auto DirInfo = expectedToOptional(E: getDirectoryFromFile(
416 FileMgr&: *this, Filename: Filename.empty() ? "." : Filename, /*CacheFailure=*/true));
417 assert(DirInfo &&
418 "The directory of a virtual file should already be in the cache.");
419
420 // Check to see if the file exists. If so, drop the virtual file
421 llvm::vfs::Status Status;
422 const char *InterndFileName = NamedFileEnt.first().data();
423 if (!getStatValue(Path: InterndFileName, Status, isFile: true, F: nullptr)) {
424 Status = llvm::vfs::Status(
425 Status.getName(), Status.getUniqueID(),
426 llvm::sys::toTimePoint(T: ModificationTime),
427 Status.getUser(), Status.getGroup(), Size,
428 Status.getType(), Status.getPermissions());
429
430 auto &RealFE = UniqueRealFiles[Status.getUniqueID()];
431 if (RealFE) {
432 // If we had already opened this file, close it now so we don't
433 // leak the descriptor. We're not going to use the file
434 // descriptor anyway, since this is a virtual file.
435 if (RealFE->File)
436 RealFE->closeFile();
437 // If we already have an entry with this inode, return it.
438 //
439 // FIXME: Surely this should add a reference by the new name, and return
440 // it instead...
441 NamedFileEnt.second = FileEntryRef::MapValue(*RealFE, *DirInfo);
442 return FileEntryRef(NamedFileEnt);
443 }
444 // File exists, but no entry - create it.
445 RealFE = new (FilesAlloc.Allocate()) FileEntry();
446 RealFE->UniqueID = Status.getUniqueID();
447 RealFE->IsNamedPipe =
448 Status.getType() == llvm::sys::fs::file_type::fifo_file;
449 fillRealPathName(UFE: RealFE, FileName: Status.getName());
450
451 UFE = RealFE;
452 } else {
453 // File does not exist, create a virtual entry.
454 UFE = new (FilesAlloc.Allocate()) FileEntry();
455 VirtualFileEntries.push_back(Elt: UFE);
456 }
457
458 NamedFileEnt.second = FileEntryRef::MapValue(*UFE, *DirInfo);
459 UFE->Size = Size;
460 UFE->ModTime = ModificationTime;
461 UFE->Dir = &DirInfo->getDirEntry();
462 UFE->UID = NextFileUID++;
463 UFE->File.reset();
464 return FileEntryRef(NamedFileEnt);
465}
466
467OptionalFileEntryRef FileManager::getBypassFile(FileEntryRef VF) {
468 // Stat of the file and return nullptr if it doesn't exist.
469 llvm::vfs::Status Status;
470 if (getStatValue(Path: VF.getName(), Status, /*isFile=*/true, /*F=*/nullptr))
471 return std::nullopt;
472
473 if (!SeenBypassFileEntries)
474 SeenBypassFileEntries = std::make_unique<
475 llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>>>();
476
477 // If we've already bypassed just use the existing one.
478 auto Insertion = SeenBypassFileEntries->insert(
479 KV: {VF.getName(), std::errc::no_such_file_or_directory});
480 if (!Insertion.second)
481 return FileEntryRef(*Insertion.first);
482
483 // Fill in the new entry from the stat.
484 FileEntry *BFE = new (FilesAlloc.Allocate()) FileEntry();
485 BypassFileEntries.push_back(Elt: BFE);
486 Insertion.first->second = FileEntryRef::MapValue(*BFE, VF.getDir());
487 BFE->Size = Status.getSize();
488 BFE->Dir = VF.getFileEntry().Dir;
489 BFE->ModTime = llvm::sys::toTimeT(TP: Status.getLastModificationTime());
490 BFE->UID = NextFileUID++;
491
492 // Save the entry in the bypass table and return.
493 return FileEntryRef(*Insertion.first);
494}
495
496bool FileManager::FixupRelativePath(SmallVectorImpl<char> &path) const {
497 StringRef pathRef(path.data(), path.size());
498
499 if (FileSystemOpts.WorkingDir.empty()
500 || llvm::sys::path::is_absolute(path: pathRef))
501 return false;
502
503 SmallString<128> NewPath(FileSystemOpts.WorkingDir);
504 llvm::sys::path::append(path&: NewPath, a: pathRef);
505 path = NewPath;
506 return true;
507}
508
509bool FileManager::makeAbsolutePath(SmallVectorImpl<char> &Path) const {
510 bool Changed = FixupRelativePath(path&: Path);
511
512 if (!llvm::sys::path::is_absolute(path: StringRef(Path.data(), Path.size()))) {
513 FS->makeAbsolute(Path);
514 Changed = true;
515 }
516
517 return Changed;
518}
519
520void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
521 llvm::SmallString<128> AbsPath(FileName);
522 // This is not the same as `VFS::getRealPath()`, which resolves symlinks
523 // but can be very expensive on real file systems.
524 // FIXME: the semantic of RealPathName is unclear, and the name might be
525 // misleading. We need to clean up the interface here.
526 makeAbsolutePath(Path&: AbsPath);
527 llvm::sys::path::remove_dots(path&: AbsPath, /*remove_dot_dot=*/true);
528 UFE->RealPathName = std::string(AbsPath);
529}
530
531llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
532FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
533 bool RequiresNullTerminator,
534 std::optional<int64_t> MaybeLimit) {
535 const FileEntry *Entry = &FE.getFileEntry();
536 // If the content is living on the file entry, return a reference to it.
537 if (Entry->Content)
538 return llvm::MemoryBuffer::getMemBuffer(Ref: Entry->Content->getMemBufferRef());
539
540 uint64_t FileSize = Entry->getSize();
541
542 if (MaybeLimit)
543 FileSize = *MaybeLimit;
544
545 // If there's a high enough chance that the file have changed since we
546 // got its size, force a stat before opening it.
547 if (isVolatile || Entry->isNamedPipe())
548 FileSize = -1;
549
550 StringRef Filename = FE.getName();
551 // If the file is already open, use the open file descriptor.
552 if (Entry->File) {
553 auto Result = Entry->File->getBuffer(Name: Filename, FileSize,
554 RequiresNullTerminator, IsVolatile: isVolatile);
555 Entry->closeFile();
556 return Result;
557 }
558
559 // Otherwise, open the file.
560 return getBufferForFileImpl(Filename, FileSize, isVolatile,
561 RequiresNullTerminator);
562}
563
564llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
565FileManager::getBufferForFileImpl(StringRef Filename, int64_t FileSize,
566 bool isVolatile,
567 bool RequiresNullTerminator) const {
568 if (FileSystemOpts.WorkingDir.empty())
569 return FS->getBufferForFile(Name: Filename, FileSize, RequiresNullTerminator,
570 IsVolatile: isVolatile);
571
572 SmallString<128> FilePath(Filename);
573 FixupRelativePath(path&: FilePath);
574 return FS->getBufferForFile(Name: FilePath, FileSize, RequiresNullTerminator,
575 IsVolatile: isVolatile);
576}
577
578/// getStatValue - Get the 'stat' information for the specified path,
579/// using the cache to accelerate it if possible. This returns true
580/// if the path points to a virtual file or does not exist, or returns
581/// false if it's an existent real file. If FileDescriptor is NULL,
582/// do directory look-up instead of file look-up.
583std::error_code
584FileManager::getStatValue(StringRef Path, llvm::vfs::Status &Status,
585 bool isFile, std::unique_ptr<llvm::vfs::File> *F) {
586 // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
587 // absolute!
588 if (FileSystemOpts.WorkingDir.empty())
589 return FileSystemStatCache::get(Path, Status, isFile, F,
590 Cache: StatCache.get(), FS&: *FS);
591
592 SmallString<128> FilePath(Path);
593 FixupRelativePath(path&: FilePath);
594
595 return FileSystemStatCache::get(Path: FilePath.c_str(), Status, isFile, F,
596 Cache: StatCache.get(), FS&: *FS);
597}
598
599std::error_code
600FileManager::getNoncachedStatValue(StringRef Path,
601 llvm::vfs::Status &Result) {
602 SmallString<128> FilePath(Path);
603 FixupRelativePath(path&: FilePath);
604
605 llvm::ErrorOr<llvm::vfs::Status> S = FS->status(Path: FilePath.c_str());
606 if (!S)
607 return S.getError();
608 Result = *S;
609 return std::error_code();
610}
611
612void FileManager::GetUniqueIDMapping(
613 SmallVectorImpl<OptionalFileEntryRef> &UIDToFiles) const {
614 UIDToFiles.clear();
615 UIDToFiles.resize(N: NextFileUID);
616
617 for (const auto &Entry : SeenFileEntries) {
618 // Only return files that exist and are not redirected.
619 if (!Entry.getValue() || !Entry.getValue()->V.is<FileEntry *>())
620 continue;
621 FileEntryRef FE(Entry);
622 // Add this file if it's the first one with the UID, or if its name is
623 // better than the existing one.
624 OptionalFileEntryRef &ExistingFE = UIDToFiles[FE.getUID()];
625 if (!ExistingFE || FE.getName() < ExistingFE->getName())
626 ExistingFE = FE;
627 }
628}
629
630StringRef FileManager::getCanonicalName(DirectoryEntryRef Dir) {
631 return getCanonicalName(Entry: Dir, Name: Dir.getName());
632}
633
634StringRef FileManager::getCanonicalName(FileEntryRef File) {
635 return getCanonicalName(Entry: File, Name: File.getName());
636}
637
638StringRef FileManager::getCanonicalName(const void *Entry, StringRef Name) {
639 llvm::DenseMap<const void *, llvm::StringRef>::iterator Known =
640 CanonicalNames.find(Val: Entry);
641 if (Known != CanonicalNames.end())
642 return Known->second;
643
644 // Name comes from FileEntry/DirectoryEntry::getName(), so it is safe to
645 // store it in the DenseMap below.
646 StringRef CanonicalName(Name);
647
648 SmallString<256> AbsPathBuf;
649 SmallString<256> RealPathBuf;
650 if (!FS->getRealPath(Path: Name, Output&: RealPathBuf)) {
651 if (is_style_windows(S: llvm::sys::path::Style::native)) {
652 // For Windows paths, only use the real path if it doesn't resolve
653 // a substitute drive, as those are used to avoid MAX_PATH issues.
654 AbsPathBuf = Name;
655 if (!FS->makeAbsolute(Path&: AbsPathBuf)) {
656 if (llvm::sys::path::root_name(path: RealPathBuf) ==
657 llvm::sys::path::root_name(path: AbsPathBuf)) {
658 CanonicalName = RealPathBuf.str().copy(A&: CanonicalNameStorage);
659 } else {
660 // Fallback to using the absolute path.
661 // Simplifying /../ is semantically valid on Windows even in the
662 // presence of symbolic links.
663 llvm::sys::path::remove_dots(path&: AbsPathBuf, /*remove_dot_dot=*/true);
664 CanonicalName = AbsPathBuf.str().copy(A&: CanonicalNameStorage);
665 }
666 }
667 } else {
668 CanonicalName = RealPathBuf.str().copy(A&: CanonicalNameStorage);
669 }
670 }
671
672 CanonicalNames.insert(KV: {Entry, CanonicalName});
673 return CanonicalName;
674}
675
676void FileManager::AddStats(const FileManager &Other) {
677 assert(&Other != this && "Collecting stats into the same FileManager");
678 NumDirLookups += Other.NumDirLookups;
679 NumFileLookups += Other.NumFileLookups;
680 NumDirCacheMisses += Other.NumDirCacheMisses;
681 NumFileCacheMisses += Other.NumFileCacheMisses;
682}
683
684void FileManager::PrintStats() const {
685 llvm::errs() << "\n*** File Manager Stats:\n";
686 llvm::errs() << UniqueRealFiles.size() << " real files found, "
687 << UniqueRealDirs.size() << " real dirs found.\n";
688 llvm::errs() << VirtualFileEntries.size() << " virtual files found, "
689 << VirtualDirectoryEntries.size() << " virtual dirs found.\n";
690 llvm::errs() << NumDirLookups << " dir lookups, "
691 << NumDirCacheMisses << " dir cache misses.\n";
692 llvm::errs() << NumFileLookups << " file lookups, "
693 << NumFileCacheMisses << " file cache misses.\n";
694
695 //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups;
696}
697