| //===- FileSystemStatCache.h - Caching for 'stat' calls ---------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// \file |
| /// Defines the FileSystemStatCache interface. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |
| #define LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |
| |
| #include "clang/Basic/LLVM.h" |
| #include "llvm/ADT/StringMap.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Support/Allocator.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/VirtualFileSystem.h" |
| #include <cstdint> |
| #include <ctime> |
| #include <memory> |
| #include <string> |
| #include <utility> |
| |
| namespace clang { |
| |
| /// Abstract interface for introducing a FileManager cache for 'stat' |
| /// system calls, which is used by precompiled and pretokenized headers to |
| /// improve performance. |
| class FileSystemStatCache { |
| virtual void anchor(); |
| |
| public: |
| virtual ~FileSystemStatCache() = default; |
| |
| /// Get the 'stat' information for the specified path, using the cache |
| /// to accelerate it if possible. |
| /// |
| /// \returns \c true if the path does not exist or \c false if it exists. |
| /// |
| /// If isFile is true, then this lookup should only return success for files |
| /// (not directories). If it is false this lookup should only return |
| /// success for directories (not files). On a successful file lookup, the |
| /// implementation can optionally fill in \p F with a valid \p File object and |
| /// the client guarantees that it will close it. |
| static std::error_code |
| get(StringRef Path, llvm::vfs::Status &Status, bool isFile, |
| std::unique_ptr<llvm::vfs::File> *F, |
| FileSystemStatCache *Cache, llvm::vfs::FileSystem &FS); |
| |
| protected: |
| // FIXME: The pointer here is a non-owning/optional reference to the |
| // unique_ptr. Optional<unique_ptr<vfs::File>&> might be nicer, but |
| // Optional needs some work to support references so this isn't possible yet. |
| virtual std::error_code getStat(StringRef Path, llvm::vfs::Status &Status, |
| bool isFile, |
| std::unique_ptr<llvm::vfs::File> *F, |
| llvm::vfs::FileSystem &FS) = 0; |
| }; |
| |
| /// A stat "cache" that can be used by FileManager to keep |
| /// track of the results of stat() calls that occur throughout the |
| /// execution of the front end. |
| class MemorizeStatCalls : public FileSystemStatCache { |
| public: |
| /// The set of stat() calls that have been seen. |
| llvm::StringMap<llvm::vfs::Status, llvm::BumpPtrAllocator> StatCalls; |
| |
| using iterator = |
| llvm::StringMap<llvm::vfs::Status, |
| llvm::BumpPtrAllocator>::const_iterator; |
| |
| iterator begin() const { return StatCalls.begin(); } |
| iterator end() const { return StatCalls.end(); } |
| |
| std::error_code getStat(StringRef Path, llvm::vfs::Status &Status, |
| bool isFile, |
| std::unique_ptr<llvm::vfs::File> *F, |
| llvm::vfs::FileSystem &FS) override; |
| }; |
| |
| } // namespace clang |
| |
| #endif // LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |