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Diffstat (limited to 'clang-r344140b/include/llvm/Support/VirtualFileSystem.h')
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1 files changed, 522 insertions, 0 deletions
diff --git a/clang-r344140b/include/llvm/Support/VirtualFileSystem.h b/clang-r344140b/include/llvm/Support/VirtualFileSystem.h new file mode 100644 index 00000000..f2f8ffaf --- /dev/null +++ b/clang-r344140b/include/llvm/Support/VirtualFileSystem.h @@ -0,0 +1,522 @@ +//===- VirtualFileSystem.h - Virtual File System Layer ----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +/// \file +/// Defines the virtual file system interface vfs::FileSystem. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_VIRTUALFILESYSTEM_H +#define LLVM_SUPPORT_VIRTUALFILESYSTEM_H + +#include "llvm/ADT/IntrusiveRefCntPtr.h" +#include "llvm/ADT/None.h" +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Twine.h" +#include "llvm/Support/Chrono.h" +#include "llvm/Support/ErrorOr.h" +#include "llvm/Support/FileSystem.h" +#include "llvm/Support/SourceMgr.h" +#include <cassert> +#include <cstdint> +#include <ctime> +#include <memory> +#include <stack> +#include <string> +#include <system_error> +#include <utility> +#include <vector> + +namespace llvm { + +class MemoryBuffer; + +namespace vfs { + +/// The result of a \p status operation. +class Status { + std::string Name; + llvm::sys::fs::UniqueID UID; + llvm::sys::TimePoint<> MTime; + uint32_t User; + uint32_t Group; + uint64_t Size; + llvm::sys::fs::file_type Type = llvm::sys::fs::file_type::status_error; + llvm::sys::fs::perms Perms; + +public: + // FIXME: remove when files support multiple names + bool IsVFSMapped = false; + + Status() = default; + Status(const llvm::sys::fs::file_status &Status); + Status(StringRef Name, llvm::sys::fs::UniqueID UID, + llvm::sys::TimePoint<> MTime, uint32_t User, uint32_t Group, + uint64_t Size, llvm::sys::fs::file_type Type, + llvm::sys::fs::perms Perms); + + /// Get a copy of a Status with a different name. + static Status copyWithNewName(const Status &In, StringRef NewName); + static Status copyWithNewName(const llvm::sys::fs::file_status &In, + StringRef NewName); + + /// Returns the name that should be used for this file or directory. + StringRef getName() const { return Name; } + + /// @name Status interface from llvm::sys::fs + /// @{ + llvm::sys::fs::file_type getType() const { return Type; } + llvm::sys::fs::perms getPermissions() const { return Perms; } + llvm::sys::TimePoint<> getLastModificationTime() const { return MTime; } + llvm::sys::fs::UniqueID getUniqueID() const { return UID; } + uint32_t getUser() const { return User; } + uint32_t getGroup() const { return Group; } + uint64_t getSize() const { return Size; } + /// @} + /// @name Status queries + /// These are static queries in llvm::sys::fs. + /// @{ + bool equivalent(const Status &Other) const; + bool isDirectory() const; + bool isRegularFile() const; + bool isOther() const; + bool isSymlink() const; + bool isStatusKnown() const; + bool exists() const; + /// @} +}; + +/// Represents an open file. +class File { +public: + /// Destroy the file after closing it (if open). + /// Sub-classes should generally call close() inside their destructors. We + /// cannot do that from the base class, since close is virtual. + virtual ~File(); + + /// Get the status of the file. + virtual llvm::ErrorOr<Status> status() = 0; + + /// Get the name of the file + virtual llvm::ErrorOr<std::string> getName() { + if (auto Status = status()) + return Status->getName().str(); + else + return Status.getError(); + } + + /// Get the contents of the file as a \p MemoryBuffer. + virtual llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> + getBuffer(const Twine &Name, int64_t FileSize = -1, + bool RequiresNullTerminator = true, bool IsVolatile = false) = 0; + + /// Closes the file. + virtual std::error_code close() = 0; +}; + +/// A member of a directory, yielded by a directory_iterator. +/// Only information available on most platforms is included. +class directory_entry { + std::string Path; + llvm::sys::fs::file_type Type; + +public: + directory_entry() = default; + directory_entry(std::string Path, llvm::sys::fs::file_type Type) + : Path(std::move(Path)), Type(Type) {} + + llvm::StringRef path() const { return Path; } + llvm::sys::fs::file_type type() const { return Type; } +}; + +namespace detail { + +/// An interface for virtual file systems to provide an iterator over the +/// (non-recursive) contents of a directory. +struct DirIterImpl { + virtual ~DirIterImpl(); + + /// Sets \c CurrentEntry to the next entry in the directory on success, + /// to directory_entry() at end, or returns a system-defined \c error_code. + virtual std::error_code increment() = 0; + + directory_entry CurrentEntry; +}; + +} // namespace detail + +/// An input iterator over the entries in a virtual path, similar to +/// llvm::sys::fs::directory_iterator. +class directory_iterator { + std::shared_ptr<detail::DirIterImpl> Impl; // Input iterator semantics on copy + +public: + directory_iterator(std::shared_ptr<detail::DirIterImpl> I) + : Impl(std::move(I)) { + assert(Impl.get() != nullptr && "requires non-null implementation"); + if (Impl->CurrentEntry.path().empty()) + Impl.reset(); // Normalize the end iterator to Impl == nullptr. + } + + /// Construct an 'end' iterator. + directory_iterator() = default; + + /// Equivalent to operator++, with an error code. + directory_iterator &increment(std::error_code &EC) { + assert(Impl && "attempting to increment past end"); + EC = Impl->increment(); + if (Impl->CurrentEntry.path().empty()) + Impl.reset(); // Normalize the end iterator to Impl == nullptr. + return *this; + } + + const directory_entry &operator*() const { return Impl->CurrentEntry; } + const directory_entry *operator->() const { return &Impl->CurrentEntry; } + + bool operator==(const directory_iterator &RHS) const { + if (Impl && RHS.Impl) + return Impl->CurrentEntry.path() == RHS.Impl->CurrentEntry.path(); + return !Impl && !RHS.Impl; + } + bool operator!=(const directory_iterator &RHS) const { + return !(*this == RHS); + } +}; + +class FileSystem; + +/// An input iterator over the recursive contents of a virtual path, +/// similar to llvm::sys::fs::recursive_directory_iterator. +class recursive_directory_iterator { + using IterState = + std::stack<directory_iterator, std::vector<directory_iterator>>; + + FileSystem *FS; + std::shared_ptr<IterState> State; // Input iterator semantics on copy. + +public: + recursive_directory_iterator(FileSystem &FS, const Twine &Path, + std::error_code &EC); + + /// Construct an 'end' iterator. + recursive_directory_iterator() = default; + + /// Equivalent to operator++, with an error code. + recursive_directory_iterator &increment(std::error_code &EC); + + const directory_entry &operator*() const { return *State->top(); } + const directory_entry *operator->() const { return &*State->top(); } + + bool operator==(const recursive_directory_iterator &Other) const { + return State == Other.State; // identity + } + bool operator!=(const recursive_directory_iterator &RHS) const { + return !(*this == RHS); + } + + /// Gets the current level. Starting path is at level 0. + int level() const { + assert(!State->empty() && "Cannot get level without any iteration state"); + return State->size() - 1; + } +}; + +/// The virtual file system interface. +class FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem> { +public: + virtual ~FileSystem(); + + /// Get the status of the entry at \p Path, if one exists. + virtual llvm::ErrorOr<Status> status(const Twine &Path) = 0; + + /// Get a \p File object for the file at \p Path, if one exists. + virtual llvm::ErrorOr<std::unique_ptr<File>> + openFileForRead(const Twine &Path) = 0; + + /// This is a convenience method that opens a file, gets its content and then + /// closes the file. + llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> + getBufferForFile(const Twine &Name, int64_t FileSize = -1, + bool RequiresNullTerminator = true, bool IsVolatile = false); + + /// Get a directory_iterator for \p Dir. + /// \note The 'end' iterator is directory_iterator(). + virtual directory_iterator dir_begin(const Twine &Dir, + std::error_code &EC) = 0; + + /// Set the working directory. This will affect all following operations on + /// this file system and may propagate down for nested file systems. + virtual std::error_code setCurrentWorkingDirectory(const Twine &Path) = 0; + + /// Get the working directory of this file system. + virtual llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const = 0; + + /// Gets real path of \p Path e.g. collapse all . and .. patterns, resolve + /// symlinks. For real file system, this uses `llvm::sys::fs::real_path`. + /// This returns errc::operation_not_permitted if not implemented by subclass. + virtual std::error_code getRealPath(const Twine &Path, + SmallVectorImpl<char> &Output) const; + + /// Check whether a file exists. Provided for convenience. + bool exists(const Twine &Path); + + /// Make \a Path an absolute path. + /// + /// Makes \a Path absolute using the current directory if it is not already. + /// An empty \a Path will result in the current directory. + /// + /// /absolute/path => /absolute/path + /// relative/../path => <current-directory>/relative/../path + /// + /// \param Path A path that is modified to be an absolute path. + /// \returns success if \a path has been made absolute, otherwise a + /// platform-specific error_code. + std::error_code makeAbsolute(SmallVectorImpl<char> &Path) const; +}; + +/// Gets an \p vfs::FileSystem for the 'real' file system, as seen by +/// the operating system. +IntrusiveRefCntPtr<FileSystem> getRealFileSystem(); + +/// A file system that allows overlaying one \p AbstractFileSystem on top +/// of another. +/// +/// Consists of a stack of >=1 \p FileSystem objects, which are treated as being +/// one merged file system. When there is a directory that exists in more than +/// one file system, the \p OverlayFileSystem contains a directory containing +/// the union of their contents. The attributes (permissions, etc.) of the +/// top-most (most recently added) directory are used. When there is a file +/// that exists in more than one file system, the file in the top-most file +/// system overrides the other(s). +class OverlayFileSystem : public FileSystem { + using FileSystemList = SmallVector<IntrusiveRefCntPtr<FileSystem>, 1>; + + /// The stack of file systems, implemented as a list in order of + /// their addition. + FileSystemList FSList; + +public: + OverlayFileSystem(IntrusiveRefCntPtr<FileSystem> Base); + + /// Pushes a file system on top of the stack. + void pushOverlay(IntrusiveRefCntPtr<FileSystem> FS); + + llvm::ErrorOr<Status> status(const Twine &Path) override; + llvm::ErrorOr<std::unique_ptr<File>> + openFileForRead(const Twine &Path) override; + directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override; + llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override; + std::error_code setCurrentWorkingDirectory(const Twine &Path) override; + std::error_code getRealPath(const Twine &Path, + SmallVectorImpl<char> &Output) const override; + + using iterator = FileSystemList::reverse_iterator; + using const_iterator = FileSystemList::const_reverse_iterator; + + /// Get an iterator pointing to the most recently added file system. + iterator overlays_begin() { return FSList.rbegin(); } + const_iterator overlays_begin() const { return FSList.rbegin(); } + + /// Get an iterator pointing one-past the least recently added file + /// system. + iterator overlays_end() { return FSList.rend(); } + const_iterator overlays_end() const { return FSList.rend(); } +}; + +/// By default, this delegates all calls to the underlying file system. This +/// is useful when derived file systems want to override some calls and still +/// proxy other calls. +class ProxyFileSystem : public FileSystem { +public: + explicit ProxyFileSystem(IntrusiveRefCntPtr<FileSystem> FS) + : FS(std::move(FS)) {} + + llvm::ErrorOr<Status> status(const Twine &Path) override { + return FS->status(Path); + } + llvm::ErrorOr<std::unique_ptr<File>> + openFileForRead(const Twine &Path) override { + return FS->openFileForRead(Path); + } + directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override { + return FS->dir_begin(Dir, EC); + } + llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override { + return FS->getCurrentWorkingDirectory(); + } + std::error_code setCurrentWorkingDirectory(const Twine &Path) override { + return FS->setCurrentWorkingDirectory(Path); + } + std::error_code getRealPath(const Twine &Path, + SmallVectorImpl<char> &Output) const override { + return FS->getRealPath(Path, Output); + } + +protected: + FileSystem &getUnderlyingFS() { return *FS; } + +private: + IntrusiveRefCntPtr<FileSystem> FS; +}; + +namespace detail { + +class InMemoryDirectory; +class InMemoryFile; + +} // namespace detail + +/// An in-memory file system. +class InMemoryFileSystem : public FileSystem { + std::unique_ptr<detail::InMemoryDirectory> Root; + std::string WorkingDirectory; + bool UseNormalizedPaths = true; + + /// If HardLinkTarget is non-null, a hardlink is created to the To path which + /// must be a file. If it is null then it adds the file as the public addFile. + bool addFile(const Twine &Path, time_t ModificationTime, + std::unique_ptr<llvm::MemoryBuffer> Buffer, + Optional<uint32_t> User, Optional<uint32_t> Group, + Optional<llvm::sys::fs::file_type> Type, + Optional<llvm::sys::fs::perms> Perms, + const detail::InMemoryFile *HardLinkTarget); + +public: + explicit InMemoryFileSystem(bool UseNormalizedPaths = true); + ~InMemoryFileSystem() override; + + /// Add a file containing a buffer or a directory to the VFS with a + /// path. The VFS owns the buffer. If present, User, Group, Type + /// and Perms apply to the newly-created file or directory. + /// \return true if the file or directory was successfully added, + /// false if the file or directory already exists in the file system with + /// different contents. + bool addFile(const Twine &Path, time_t ModificationTime, + std::unique_ptr<llvm::MemoryBuffer> Buffer, + Optional<uint32_t> User = None, Optional<uint32_t> Group = None, + Optional<llvm::sys::fs::file_type> Type = None, + Optional<llvm::sys::fs::perms> Perms = None); + + /// Add a hard link to a file. + /// Here hard links are not intended to be fully equivalent to the classical + /// filesystem. Both the hard link and the file share the same buffer and + /// status (and thus have the same UniqueID). Because of this there is no way + /// to distinguish between the link and the file after the link has been + /// added. + /// + /// The To path must be an existing file or a hardlink. The From file must not + /// have been added before. The To Path must not be a directory. The From Node + /// is added as a hard link which points to the resolved file of To Node. + /// \return true if the above condition is satisfied and hardlink was + /// successfully created, false otherwise. + bool addHardLink(const Twine &From, const Twine &To); + + /// Add a buffer to the VFS with a path. The VFS does not own the buffer. + /// If present, User, Group, Type and Perms apply to the newly-created file + /// or directory. + /// \return true if the file or directory was successfully added, + /// false if the file or directory already exists in the file system with + /// different contents. + bool addFileNoOwn(const Twine &Path, time_t ModificationTime, + llvm::MemoryBuffer *Buffer, Optional<uint32_t> User = None, + Optional<uint32_t> Group = None, + Optional<llvm::sys::fs::file_type> Type = None, + Optional<llvm::sys::fs::perms> Perms = None); + + std::string toString() const; + + /// Return true if this file system normalizes . and .. in paths. + bool useNormalizedPaths() const { return UseNormalizedPaths; } + + llvm::ErrorOr<Status> status(const Twine &Path) override; + llvm::ErrorOr<std::unique_ptr<File>> + openFileForRead(const Twine &Path) override; + directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override; + + llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override { + return WorkingDirectory; + } + /// Canonicalizes \p Path by combining with the current working + /// directory and normalizing the path (e.g. remove dots). If the current + /// working directory is not set, this returns errc::operation_not_permitted. + /// + /// This doesn't resolve symlinks as they are not supported in in-memory file + /// system. + std::error_code getRealPath(const Twine &Path, + SmallVectorImpl<char> &Output) const override; + + std::error_code setCurrentWorkingDirectory(const Twine &Path) override; +}; + +/// Get a globally unique ID for a virtual file or directory. +llvm::sys::fs::UniqueID getNextVirtualUniqueID(); + +/// Gets a \p FileSystem for a virtual file system described in YAML +/// format. +IntrusiveRefCntPtr<FileSystem> +getVFSFromYAML(std::unique_ptr<llvm::MemoryBuffer> Buffer, + llvm::SourceMgr::DiagHandlerTy DiagHandler, + StringRef YAMLFilePath, void *DiagContext = nullptr, + IntrusiveRefCntPtr<FileSystem> ExternalFS = getRealFileSystem()); + +struct YAMLVFSEntry { + template <typename T1, typename T2> + YAMLVFSEntry(T1 &&VPath, T2 &&RPath) + : VPath(std::forward<T1>(VPath)), RPath(std::forward<T2>(RPath)) {} + std::string VPath; + std::string RPath; +}; + +/// Collect all pairs of <virtual path, real path> entries from the +/// \p YAMLFilePath. This is used by the module dependency collector to forward +/// the entries into the reproducer output VFS YAML file. +void collectVFSFromYAML( + std::unique_ptr<llvm::MemoryBuffer> Buffer, + llvm::SourceMgr::DiagHandlerTy DiagHandler, StringRef YAMLFilePath, + SmallVectorImpl<YAMLVFSEntry> &CollectedEntries, + void *DiagContext = nullptr, + IntrusiveRefCntPtr<FileSystem> ExternalFS = getRealFileSystem()); + +class YAMLVFSWriter { + std::vector<YAMLVFSEntry> Mappings; + Optional<bool> IsCaseSensitive; + Optional<bool> IsOverlayRelative; + Optional<bool> UseExternalNames; + Optional<bool> IgnoreNonExistentContents; + std::string OverlayDir; + +public: + YAMLVFSWriter() = default; + + void addFileMapping(StringRef VirtualPath, StringRef RealPath); + + void setCaseSensitivity(bool CaseSensitive) { + IsCaseSensitive = CaseSensitive; + } + + void setUseExternalNames(bool UseExtNames) { UseExternalNames = UseExtNames; } + + void setIgnoreNonExistentContents(bool IgnoreContents) { + IgnoreNonExistentContents = IgnoreContents; + } + + void setOverlayDir(StringRef OverlayDirectory) { + IsOverlayRelative = true; + OverlayDir.assign(OverlayDirectory.str()); + } + + void write(llvm::raw_ostream &OS); +}; + +} // namespace vfs +} // namespace llvm + +#endif // LLVM_SUPPORT_VIRTUALFILESYSTEM_H |