1 //===- VirtualFileSystem.h - Virtual File System Layer ----------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
10 /// Defines the virtual file system interface vfs::FileSystem.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_VIRTUALFILESYSTEM_H
15 #define LLVM_SUPPORT_VIRTUALFILESYSTEM_H
17 #include "llvm/ADT/IntrusiveRefCntPtr.h"
18 #include "llvm/ADT/None.h"
19 #include "llvm/ADT/Optional.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/Support/Chrono.h"
23 #include "llvm/Support/ErrorOr.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/Path.h"
26 #include "llvm/Support/SourceMgr.h"
33 #include <system_error>
44 /// The result of a \p status operation.
47 llvm::sys::fs::UniqueID UID;
48 llvm::sys::TimePoint<> MTime;
52 llvm::sys::fs::file_type Type = llvm::sys::fs::file_type::status_error;
53 llvm::sys::fs::perms Perms;
56 // FIXME: remove when files support multiple names
57 bool IsVFSMapped = false;
60 Status(const llvm::sys::fs::file_status &Status);
61 Status(const Twine &Name, llvm::sys::fs::UniqueID UID,
62 llvm::sys::TimePoint<> MTime, uint32_t User, uint32_t Group,
63 uint64_t Size, llvm::sys::fs::file_type Type,
64 llvm::sys::fs::perms Perms);
66 /// Get a copy of a Status with a different name.
67 static Status copyWithNewName(const Status &In, const Twine &NewName);
68 static Status copyWithNewName(const llvm::sys::fs::file_status &In,
69 const Twine &NewName);
71 /// Returns the name that should be used for this file or directory.
72 StringRef getName() const { return Name; }
74 /// @name Status interface from llvm::sys::fs
76 llvm::sys::fs::file_type getType() const { return Type; }
77 llvm::sys::fs::perms getPermissions() const { return Perms; }
78 llvm::sys::TimePoint<> getLastModificationTime() const { return MTime; }
79 llvm::sys::fs::UniqueID getUniqueID() const { return UID; }
80 uint32_t getUser() const { return User; }
81 uint32_t getGroup() const { return Group; }
82 uint64_t getSize() const { return Size; }
84 /// @name Status queries
85 /// These are static queries in llvm::sys::fs.
87 bool equivalent(const Status &Other) const;
88 bool isDirectory() const;
89 bool isRegularFile() const;
91 bool isSymlink() const;
92 bool isStatusKnown() const;
97 /// Represents an open file.
100 /// Destroy the file after closing it (if open).
101 /// Sub-classes should generally call close() inside their destructors. We
102 /// cannot do that from the base class, since close is virtual.
105 /// Get the status of the file.
106 virtual llvm::ErrorOr<Status> status() = 0;
108 /// Get the name of the file
109 virtual llvm::ErrorOr<std::string> getName() {
110 if (auto Status = status())
111 return Status->getName().str();
113 return Status.getError();
116 /// Get the contents of the file as a \p MemoryBuffer.
117 virtual llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
118 getBuffer(const Twine &Name, int64_t FileSize = -1,
119 bool RequiresNullTerminator = true, bool IsVolatile = false) = 0;
122 virtual std::error_code close() = 0;
125 /// A member of a directory, yielded by a directory_iterator.
126 /// Only information available on most platforms is included.
127 class directory_entry {
129 llvm::sys::fs::file_type Type = llvm::sys::fs::file_type::type_unknown;
132 directory_entry() = default;
133 directory_entry(std::string Path, llvm::sys::fs::file_type Type)
134 : Path(std::move(Path)), Type(Type) {}
136 llvm::StringRef path() const { return Path; }
137 llvm::sys::fs::file_type type() const { return Type; }
142 /// An interface for virtual file systems to provide an iterator over the
143 /// (non-recursive) contents of a directory.
145 virtual ~DirIterImpl();
147 /// Sets \c CurrentEntry to the next entry in the directory on success,
148 /// to directory_entry() at end, or returns a system-defined \c error_code.
149 virtual std::error_code increment() = 0;
151 directory_entry CurrentEntry;
154 } // namespace detail
156 /// An input iterator over the entries in a virtual path, similar to
157 /// llvm::sys::fs::directory_iterator.
158 class directory_iterator {
159 std::shared_ptr<detail::DirIterImpl> Impl; // Input iterator semantics on copy
162 directory_iterator(std::shared_ptr<detail::DirIterImpl> I)
163 : Impl(std::move(I)) {
164 assert(Impl.get() != nullptr && "requires non-null implementation");
165 if (Impl->CurrentEntry.path().empty())
166 Impl.reset(); // Normalize the end iterator to Impl == nullptr.
169 /// Construct an 'end' iterator.
170 directory_iterator() = default;
172 /// Equivalent to operator++, with an error code.
173 directory_iterator &increment(std::error_code &EC) {
174 assert(Impl && "attempting to increment past end");
175 EC = Impl->increment();
176 if (Impl->CurrentEntry.path().empty())
177 Impl.reset(); // Normalize the end iterator to Impl == nullptr.
181 const directory_entry &operator*() const { return Impl->CurrentEntry; }
182 const directory_entry *operator->() const { return &Impl->CurrentEntry; }
184 bool operator==(const directory_iterator &RHS) const {
185 if (Impl && RHS.Impl)
186 return Impl->CurrentEntry.path() == RHS.Impl->CurrentEntry.path();
187 return !Impl && !RHS.Impl;
189 bool operator!=(const directory_iterator &RHS) const {
190 return !(*this == RHS);
198 /// Keeps state for the recursive_directory_iterator.
199 struct RecDirIterState {
200 std::stack<directory_iterator, std::vector<directory_iterator>> Stack;
201 bool HasNoPushRequest = false;
204 } // end namespace detail
206 /// An input iterator over the recursive contents of a virtual path,
207 /// similar to llvm::sys::fs::recursive_directory_iterator.
208 class recursive_directory_iterator {
210 std::shared_ptr<detail::RecDirIterState>
211 State; // Input iterator semantics on copy.
214 recursive_directory_iterator(FileSystem &FS, const Twine &Path,
215 std::error_code &EC);
217 /// Construct an 'end' iterator.
218 recursive_directory_iterator() = default;
220 /// Equivalent to operator++, with an error code.
221 recursive_directory_iterator &increment(std::error_code &EC);
223 const directory_entry &operator*() const { return *State->Stack.top(); }
224 const directory_entry *operator->() const { return &*State->Stack.top(); }
226 bool operator==(const recursive_directory_iterator &Other) const {
227 return State == Other.State; // identity
229 bool operator!=(const recursive_directory_iterator &RHS) const {
230 return !(*this == RHS);
233 /// Gets the current level. Starting path is at level 0.
235 assert(!State->Stack.empty() &&
236 "Cannot get level without any iteration state");
237 return State->Stack.size() - 1;
240 void no_push() { State->HasNoPushRequest = true; }
243 /// The virtual file system interface.
244 class FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem> {
246 virtual ~FileSystem();
248 /// Get the status of the entry at \p Path, if one exists.
249 virtual llvm::ErrorOr<Status> status(const Twine &Path) = 0;
251 /// Get a \p File object for the file at \p Path, if one exists.
252 virtual llvm::ErrorOr<std::unique_ptr<File>>
253 openFileForRead(const Twine &Path) = 0;
255 /// This is a convenience method that opens a file, gets its content and then
257 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
258 getBufferForFile(const Twine &Name, int64_t FileSize = -1,
259 bool RequiresNullTerminator = true, bool IsVolatile = false);
261 /// Get a directory_iterator for \p Dir.
262 /// \note The 'end' iterator is directory_iterator().
263 virtual directory_iterator dir_begin(const Twine &Dir,
264 std::error_code &EC) = 0;
266 /// Set the working directory. This will affect all following operations on
267 /// this file system and may propagate down for nested file systems.
268 virtual std::error_code setCurrentWorkingDirectory(const Twine &Path) = 0;
270 /// Get the working directory of this file system.
271 virtual llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const = 0;
273 /// Gets real path of \p Path e.g. collapse all . and .. patterns, resolve
274 /// symlinks. For real file system, this uses `llvm::sys::fs::real_path`.
275 /// This returns errc::operation_not_permitted if not implemented by subclass.
276 virtual std::error_code getRealPath(const Twine &Path,
277 SmallVectorImpl<char> &Output) const;
279 /// Check whether a file exists. Provided for convenience.
280 bool exists(const Twine &Path);
282 /// Is the file mounted on a local filesystem?
283 virtual std::error_code isLocal(const Twine &Path, bool &Result);
285 /// Make \a Path an absolute path.
287 /// Makes \a Path absolute using the current directory if it is not already.
288 /// An empty \a Path will result in the current directory.
290 /// /absolute/path => /absolute/path
291 /// relative/../path => <current-directory>/relative/../path
293 /// \param Path A path that is modified to be an absolute path.
294 /// \returns success if \a path has been made absolute, otherwise a
295 /// platform-specific error_code.
296 virtual std::error_code makeAbsolute(SmallVectorImpl<char> &Path) const;
299 /// Gets an \p vfs::FileSystem for the 'real' file system, as seen by
300 /// the operating system.
301 /// The working directory is linked to the process's working directory.
302 /// (This is usually thread-hostile).
303 IntrusiveRefCntPtr<FileSystem> getRealFileSystem();
305 /// Create an \p vfs::FileSystem for the 'real' file system, as seen by
306 /// the operating system.
307 /// It has its own working directory, independent of (but initially equal to)
308 /// that of the process.
309 std::unique_ptr<FileSystem> createPhysicalFileSystem();
311 /// A file system that allows overlaying one \p AbstractFileSystem on top
314 /// Consists of a stack of >=1 \p FileSystem objects, which are treated as being
315 /// one merged file system. When there is a directory that exists in more than
316 /// one file system, the \p OverlayFileSystem contains a directory containing
317 /// the union of their contents. The attributes (permissions, etc.) of the
318 /// top-most (most recently added) directory are used. When there is a file
319 /// that exists in more than one file system, the file in the top-most file
320 /// system overrides the other(s).
321 class OverlayFileSystem : public FileSystem {
322 using FileSystemList = SmallVector<IntrusiveRefCntPtr<FileSystem>, 1>;
324 /// The stack of file systems, implemented as a list in order of
326 FileSystemList FSList;
329 OverlayFileSystem(IntrusiveRefCntPtr<FileSystem> Base);
331 /// Pushes a file system on top of the stack.
332 void pushOverlay(IntrusiveRefCntPtr<FileSystem> FS);
334 llvm::ErrorOr<Status> status(const Twine &Path) override;
335 llvm::ErrorOr<std::unique_ptr<File>>
336 openFileForRead(const Twine &Path) override;
337 directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
338 llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
339 std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
340 std::error_code isLocal(const Twine &Path, bool &Result) override;
341 std::error_code getRealPath(const Twine &Path,
342 SmallVectorImpl<char> &Output) const override;
344 using iterator = FileSystemList::reverse_iterator;
345 using const_iterator = FileSystemList::const_reverse_iterator;
346 using reverse_iterator = FileSystemList::iterator;
347 using const_reverse_iterator = FileSystemList::const_iterator;
349 /// Get an iterator pointing to the most recently added file system.
350 iterator overlays_begin() { return FSList.rbegin(); }
351 const_iterator overlays_begin() const { return FSList.rbegin(); }
353 /// Get an iterator pointing one-past the least recently added file system.
354 iterator overlays_end() { return FSList.rend(); }
355 const_iterator overlays_end() const { return FSList.rend(); }
357 /// Get an iterator pointing to the least recently added file system.
358 reverse_iterator overlays_rbegin() { return FSList.begin(); }
359 const_reverse_iterator overlays_rbegin() const { return FSList.begin(); }
361 /// Get an iterator pointing one-past the most recently added file system.
362 reverse_iterator overlays_rend() { return FSList.end(); }
363 const_reverse_iterator overlays_rend() const { return FSList.end(); }
366 /// By default, this delegates all calls to the underlying file system. This
367 /// is useful when derived file systems want to override some calls and still
368 /// proxy other calls.
369 class ProxyFileSystem : public FileSystem {
371 explicit ProxyFileSystem(IntrusiveRefCntPtr<FileSystem> FS)
372 : FS(std::move(FS)) {}
374 llvm::ErrorOr<Status> status(const Twine &Path) override {
375 return FS->status(Path);
377 llvm::ErrorOr<std::unique_ptr<File>>
378 openFileForRead(const Twine &Path) override {
379 return FS->openFileForRead(Path);
381 directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override {
382 return FS->dir_begin(Dir, EC);
384 llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override {
385 return FS->getCurrentWorkingDirectory();
387 std::error_code setCurrentWorkingDirectory(const Twine &Path) override {
388 return FS->setCurrentWorkingDirectory(Path);
390 std::error_code getRealPath(const Twine &Path,
391 SmallVectorImpl<char> &Output) const override {
392 return FS->getRealPath(Path, Output);
394 std::error_code isLocal(const Twine &Path, bool &Result) override {
395 return FS->isLocal(Path, Result);
399 FileSystem &getUnderlyingFS() { return *FS; }
402 IntrusiveRefCntPtr<FileSystem> FS;
404 virtual void anchor();
409 class InMemoryDirectory;
412 } // namespace detail
414 /// An in-memory file system.
415 class InMemoryFileSystem : public FileSystem {
416 std::unique_ptr<detail::InMemoryDirectory> Root;
417 std::string WorkingDirectory;
418 bool UseNormalizedPaths = true;
420 /// If HardLinkTarget is non-null, a hardlink is created to the To path which
421 /// must be a file. If it is null then it adds the file as the public addFile.
422 bool addFile(const Twine &Path, time_t ModificationTime,
423 std::unique_ptr<llvm::MemoryBuffer> Buffer,
424 Optional<uint32_t> User, Optional<uint32_t> Group,
425 Optional<llvm::sys::fs::file_type> Type,
426 Optional<llvm::sys::fs::perms> Perms,
427 const detail::InMemoryFile *HardLinkTarget);
430 explicit InMemoryFileSystem(bool UseNormalizedPaths = true);
431 ~InMemoryFileSystem() override;
433 /// Add a file containing a buffer or a directory to the VFS with a
434 /// path. The VFS owns the buffer. If present, User, Group, Type
435 /// and Perms apply to the newly-created file or directory.
436 /// \return true if the file or directory was successfully added,
437 /// false if the file or directory already exists in the file system with
438 /// different contents.
439 bool addFile(const Twine &Path, time_t ModificationTime,
440 std::unique_ptr<llvm::MemoryBuffer> Buffer,
441 Optional<uint32_t> User = None, Optional<uint32_t> Group = None,
442 Optional<llvm::sys::fs::file_type> Type = None,
443 Optional<llvm::sys::fs::perms> Perms = None);
445 /// Add a hard link to a file.
446 /// Here hard links are not intended to be fully equivalent to the classical
447 /// filesystem. Both the hard link and the file share the same buffer and
448 /// status (and thus have the same UniqueID). Because of this there is no way
449 /// to distinguish between the link and the file after the link has been
452 /// The To path must be an existing file or a hardlink. The From file must not
453 /// have been added before. The To Path must not be a directory. The From Node
454 /// is added as a hard link which points to the resolved file of To Node.
455 /// \return true if the above condition is satisfied and hardlink was
456 /// successfully created, false otherwise.
457 bool addHardLink(const Twine &From, const Twine &To);
459 /// Add a buffer to the VFS with a path. The VFS does not own the buffer.
460 /// If present, User, Group, Type and Perms apply to the newly-created file
462 /// \return true if the file or directory was successfully added,
463 /// false if the file or directory already exists in the file system with
464 /// different contents.
465 bool addFileNoOwn(const Twine &Path, time_t ModificationTime,
466 llvm::MemoryBuffer *Buffer, Optional<uint32_t> User = None,
467 Optional<uint32_t> Group = None,
468 Optional<llvm::sys::fs::file_type> Type = None,
469 Optional<llvm::sys::fs::perms> Perms = None);
471 std::string toString() const;
473 /// Return true if this file system normalizes . and .. in paths.
474 bool useNormalizedPaths() const { return UseNormalizedPaths; }
476 llvm::ErrorOr<Status> status(const Twine &Path) override;
477 llvm::ErrorOr<std::unique_ptr<File>>
478 openFileForRead(const Twine &Path) override;
479 directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
481 llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override {
482 return WorkingDirectory;
484 /// Canonicalizes \p Path by combining with the current working
485 /// directory and normalizing the path (e.g. remove dots). If the current
486 /// working directory is not set, this returns errc::operation_not_permitted.
488 /// This doesn't resolve symlinks as they are not supported in in-memory file
490 std::error_code getRealPath(const Twine &Path,
491 SmallVectorImpl<char> &Output) const override;
492 std::error_code isLocal(const Twine &Path, bool &Result) override;
493 std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
496 /// Get a globally unique ID for a virtual file or directory.
497 llvm::sys::fs::UniqueID getNextVirtualUniqueID();
499 /// Gets a \p FileSystem for a virtual file system described in YAML
501 IntrusiveRefCntPtr<FileSystem>
502 getVFSFromYAML(std::unique_ptr<llvm::MemoryBuffer> Buffer,
503 llvm::SourceMgr::DiagHandlerTy DiagHandler,
504 StringRef YAMLFilePath, void *DiagContext = nullptr,
505 IntrusiveRefCntPtr<FileSystem> ExternalFS = getRealFileSystem());
507 struct YAMLVFSEntry {
508 template <typename T1, typename T2>
509 YAMLVFSEntry(T1 &&VPath, T2 &&RPath, bool IsDirectory = false)
510 : VPath(std::forward<T1>(VPath)), RPath(std::forward<T2>(RPath)),
511 IsDirectory(IsDirectory) {}
514 bool IsDirectory = false;
517 class VFSFromYamlDirIterImpl;
518 class RedirectingFileSystemParser;
520 /// A virtual file system parsed from a YAML file.
522 /// Currently, this class allows creating virtual directories and mapping
523 /// virtual file paths to existing external files, available in \c ExternalFS.
525 /// The basic structure of the parsed file is:
528 /// 'version': <version number>,
529 /// <optional configuration>
531 /// <directory entries>
536 /// All configuration options are optional.
537 /// 'case-sensitive': <boolean, default=(true for Posix, false for Windows)>
538 /// 'use-external-names': <boolean, default=true>
539 /// 'overlay-relative': <boolean, default=false>
540 /// 'fallthrough': <boolean, default=true>
542 /// Virtual directories are represented as
545 /// 'type': 'directory',
546 /// 'name': <string>,
547 /// 'contents': [ <file or directory entries> ]
551 /// The default attributes for virtual directories are:
553 /// MTime = now() when created
557 /// UniqueID = unspecified unique value
560 /// Re-mapped files are represented as
564 /// 'name': <string>,
565 /// 'use-external-name': <boolean> # Optional
566 /// 'external-contents': <path to external file>
570 /// and inherit their attributes from the external contents.
572 /// In both cases, the 'name' field may contain multiple path components (e.g.
573 /// /path/to/file). However, any directory that contains more than one child
574 /// must be uniquely represented by a directory entry.
575 class RedirectingFileSystem : public vfs::FileSystem {
577 enum EntryKind { EK_Directory, EK_File };
579 /// A single file or directory in the VFS.
585 Entry(EntryKind K, StringRef Name) : Kind(K), Name(Name) {}
586 virtual ~Entry() = default;
588 StringRef getName() const { return Name; }
589 EntryKind getKind() const { return Kind; }
592 class RedirectingDirectoryEntry : public Entry {
593 std::vector<std::unique_ptr<Entry>> Contents;
597 RedirectingDirectoryEntry(StringRef Name,
598 std::vector<std::unique_ptr<Entry>> Contents,
600 : Entry(EK_Directory, Name), Contents(std::move(Contents)),
602 RedirectingDirectoryEntry(StringRef Name, Status S)
603 : Entry(EK_Directory, Name), S(std::move(S)) {}
605 Status getStatus() { return S; }
607 void addContent(std::unique_ptr<Entry> Content) {
608 Contents.push_back(std::move(Content));
611 Entry *getLastContent() const { return Contents.back().get(); }
613 using iterator = decltype(Contents)::iterator;
615 iterator contents_begin() { return Contents.begin(); }
616 iterator contents_end() { return Contents.end(); }
618 static bool classof(const Entry *E) { return E->getKind() == EK_Directory; }
621 class RedirectingFileEntry : public Entry {
623 enum NameKind { NK_NotSet, NK_External, NK_Virtual };
626 std::string ExternalContentsPath;
630 RedirectingFileEntry(StringRef Name, StringRef ExternalContentsPath,
632 : Entry(EK_File, Name), ExternalContentsPath(ExternalContentsPath),
635 StringRef getExternalContentsPath() const { return ExternalContentsPath; }
637 /// whether to use the external path as the name for this file.
638 bool useExternalName(bool GlobalUseExternalName) const {
639 return UseName == NK_NotSet ? GlobalUseExternalName
640 : (UseName == NK_External);
643 NameKind getUseName() const { return UseName; }
645 static bool classof(const Entry *E) { return E->getKind() == EK_File; }
649 friend class VFSFromYamlDirIterImpl;
650 friend class RedirectingFileSystemParser;
652 bool shouldUseExternalFS() const {
653 return ExternalFSValidWD && IsFallthrough;
656 // In a RedirectingFileSystem, keys can be specified in Posix or Windows
657 // style (or even a mixture of both), so this comparison helper allows
658 // slashes (representing a root) to match backslashes (and vice versa). Note
659 // that, other than the root, path components should not contain slashes or
661 bool pathComponentMatches(llvm::StringRef lhs, llvm::StringRef rhs) const {
662 if ((CaseSensitive ? lhs.equals(rhs) : lhs.equals_lower(rhs)))
664 return (lhs == "/" && rhs == "\\") || (lhs == "\\" && rhs == "/");
667 /// The root(s) of the virtual file system.
668 std::vector<std::unique_ptr<Entry>> Roots;
670 /// The current working directory of the file system.
671 std::string WorkingDirectory;
673 /// Whether the current working directory is valid for the external FS.
674 bool ExternalFSValidWD = false;
676 /// The file system to use for external references.
677 IntrusiveRefCntPtr<FileSystem> ExternalFS;
679 /// If IsRelativeOverlay is set, this represents the directory
680 /// path that should be prefixed to each 'external-contents' entry
681 /// when reading from YAML files.
682 std::string ExternalContentsPrefixDir;
684 /// @name Configuration
687 /// Whether to perform case-sensitive comparisons.
689 /// Currently, case-insensitive matching only works correctly with ASCII.
697 /// IsRelativeOverlay marks whether a ExternalContentsPrefixDir path must
698 /// be prefixed in every 'external-contents' when reading from YAML files.
699 bool IsRelativeOverlay = false;
701 /// Whether to use to use the value of 'external-contents' for the
702 /// names of files. This global value is overridable on a per-file basis.
703 bool UseExternalNames = true;
705 /// Whether to attempt a file lookup in external file system after it wasn't
707 bool IsFallthrough = true;
710 RedirectingFileSystem(IntrusiveRefCntPtr<FileSystem> ExternalFS);
712 /// Looks up the path <tt>[Start, End)</tt> in \p From, possibly
713 /// recursing into the contents of \p From if it is a directory.
714 ErrorOr<Entry *> lookupPath(llvm::sys::path::const_iterator Start,
715 llvm::sys::path::const_iterator End,
718 /// Get the status of a given an \c Entry.
719 ErrorOr<Status> status(const Twine &Path, Entry *E);
722 /// Looks up \p Path in \c Roots.
723 ErrorOr<Entry *> lookupPath(const Twine &Path) const;
725 /// Parses \p Buffer, which is expected to be in YAML format and
726 /// returns a virtual file system representing its contents.
727 static RedirectingFileSystem *
728 create(std::unique_ptr<MemoryBuffer> Buffer,
729 SourceMgr::DiagHandlerTy DiagHandler, StringRef YAMLFilePath,
730 void *DiagContext, IntrusiveRefCntPtr<FileSystem> ExternalFS);
732 ErrorOr<Status> status(const Twine &Path) override;
733 ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override;
735 std::error_code getRealPath(const Twine &Path,
736 SmallVectorImpl<char> &Output) const override;
738 llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
740 std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
742 std::error_code isLocal(const Twine &Path, bool &Result) override;
744 std::error_code makeAbsolute(SmallVectorImpl<char> &Path) const override;
746 directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
748 void setExternalContentsPrefixDir(StringRef PrefixDir);
750 StringRef getExternalContentsPrefixDir() const;
752 void dump(raw_ostream &OS) const;
753 void dumpEntry(raw_ostream &OS, Entry *E, int NumSpaces = 0) const;
754 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
755 LLVM_DUMP_METHOD void dump() const;
759 /// Collect all pairs of <virtual path, real path> entries from the
760 /// \p YAMLFilePath. This is used by the module dependency collector to forward
761 /// the entries into the reproducer output VFS YAML file.
762 void collectVFSFromYAML(
763 std::unique_ptr<llvm::MemoryBuffer> Buffer,
764 llvm::SourceMgr::DiagHandlerTy DiagHandler, StringRef YAMLFilePath,
765 SmallVectorImpl<YAMLVFSEntry> &CollectedEntries,
766 void *DiagContext = nullptr,
767 IntrusiveRefCntPtr<FileSystem> ExternalFS = getRealFileSystem());
769 class YAMLVFSWriter {
770 std::vector<YAMLVFSEntry> Mappings;
771 Optional<bool> IsCaseSensitive;
772 Optional<bool> IsOverlayRelative;
773 Optional<bool> UseExternalNames;
774 std::string OverlayDir;
776 void addEntry(StringRef VirtualPath, StringRef RealPath, bool IsDirectory);
779 YAMLVFSWriter() = default;
781 void addFileMapping(StringRef VirtualPath, StringRef RealPath);
782 void addDirectoryMapping(StringRef VirtualPath, StringRef RealPath);
784 void setCaseSensitivity(bool CaseSensitive) {
785 IsCaseSensitive = CaseSensitive;
788 void setUseExternalNames(bool UseExtNames) { UseExternalNames = UseExtNames; }
790 void setOverlayDir(StringRef OverlayDirectory) {
791 IsOverlayRelative = true;
792 OverlayDir.assign(OverlayDirectory.str());
795 const std::vector<YAMLVFSEntry> &getMappings() const { return Mappings; }
797 void write(llvm::raw_ostream &OS);
803 #endif // LLVM_SUPPORT_VIRTUALFILESYSTEM_H