diff options
| author | Stephen Hines <srhines@google.com> | 2019-07-02 16:25:20 -0700 |
|---|---|---|
| committer | Ali B <abittin@gmail.com> | 2019-07-05 19:33:16 +0300 |
| commit | 9afee4e65dc5f9f5eb371683729ff67b8df81d03 (patch) | |
| tree | 4cf241d6c9044f91ee8c06e6920174d06f8de0b6 /clang-r353983e/include/clang/Basic/FileSystemStatCache.h | |
| parent | 2f19bd722c4c825320d1511c1ed83161b7f95d51 (diff) | |
clang 9.0.5 (based on r353983e) from build 5696680.
Bug: http://b/135931688
Bug: http://b/136008926
Test: N/A
Change-Id: I922d17410047d2e2df4625615352c588ee71b203
Diffstat (limited to 'clang-r353983e/include/clang/Basic/FileSystemStatCache.h')
| -rw-r--r-- | clang-r353983e/include/clang/Basic/FileSystemStatCache.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/clang-r353983e/include/clang/Basic/FileSystemStatCache.h b/clang-r353983e/include/clang/Basic/FileSystemStatCache.h new file mode 100644 index 00000000..0ae6a9eb --- /dev/null +++ b/clang-r353983e/include/clang/Basic/FileSystemStatCache.h @@ -0,0 +1,117 @@ +//===- 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 <cstdint> +#include <ctime> +#include <memory> +#include <string> +#include <utility> + +namespace llvm { + +namespace vfs { + +class File; +class FileSystem; + +} // namespace vfs +} // namespace llvm + +namespace clang { + +// FIXME: should probably replace this with vfs::Status +struct FileData { + std::string Name; + uint64_t Size = 0; + time_t ModTime = 0; + llvm::sys::fs::UniqueID UniqueID; + bool IsDirectory = false; + bool IsNamedPipe = false; + bool InPCH = false; + + // FIXME: remove this when files support multiple names + bool IsVFSMapped = false; + + FileData() = default; +}; + +/// 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; + + enum LookupResult { + /// We know the file exists and its cached stat data. + CacheExists, + + /// We know that the file doesn't exist. + CacheMissing + }; + + /// 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 bool get(StringRef Path, FileData &Data, 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 LookupResult getStat(StringRef Path, FileData &Data, 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<FileData, llvm::BumpPtrAllocator> StatCalls; + + using iterator = + llvm::StringMap<FileData, llvm::BumpPtrAllocator>::const_iterator; + + iterator begin() const { return StatCalls.begin(); } + iterator end() const { return StatCalls.end(); } + + LookupResult getStat(StringRef Path, FileData &Data, bool isFile, + std::unique_ptr<llvm::vfs::File> *F, + llvm::vfs::FileSystem &FS) override; +}; + +} // namespace clang + +#endif // LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |
