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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===- FileSystemStatCache.h - Caching for 'stat' calls ---------*- C++ -*-===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | /// \file |
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| 10 | /// Defines the FileSystemStatCache interface. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |||
| 14 | #ifndef LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |
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| 15 | #define LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |
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| 16 | |||
| 17 | #include "clang/Basic/LLVM.h" |
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| 18 | #include "llvm/ADT/StringMap.h" |
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| 19 | #include "llvm/ADT/StringRef.h" |
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| 20 | #include "llvm/Support/Allocator.h" |
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| 21 | #include "llvm/Support/FileSystem.h" |
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| 22 | #include "llvm/Support/VirtualFileSystem.h" |
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| 23 | #include <cstdint> |
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| 24 | #include <ctime> |
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| 25 | #include <memory> |
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| 26 | #include <optional> |
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| 27 | #include <string> |
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| 28 | #include <utility> |
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| 29 | |||
| 30 | namespace clang { |
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| 31 | |||
| 32 | /// Abstract interface for introducing a FileManager cache for 'stat' |
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| 33 | /// system calls, which is used by precompiled and pretokenized headers to |
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| 34 | /// improve performance. |
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| 35 | class FileSystemStatCache { |
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| 36 | virtual void anchor(); |
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| 37 | |||
| 38 | public: |
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| 39 | virtual ~FileSystemStatCache() = default; |
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| 40 | |||
| 41 | /// Get the 'stat' information for the specified path, using the cache |
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| 42 | /// to accelerate it if possible. |
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| 43 | /// |
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| 44 | /// \returns \c true if the path does not exist or \c false if it exists. |
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| 45 | /// |
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| 46 | /// If isFile is true, then this lookup should only return success for files |
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| 47 | /// (not directories). If it is false this lookup should only return |
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| 48 | /// success for directories (not files). On a successful file lookup, the |
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| 49 | /// implementation can optionally fill in \p F with a valid \p File object and |
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| 50 | /// the client guarantees that it will close it. |
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| 51 | static std::error_code |
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| 52 | get(StringRef Path, llvm::vfs::Status &Status, bool isFile, |
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| 53 | std::unique_ptr<llvm::vfs::File> *F, |
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| 54 | FileSystemStatCache *Cache, llvm::vfs::FileSystem &FS); |
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| 55 | |||
| 56 | protected: |
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| 57 | // FIXME: The pointer here is a non-owning/optional reference to the |
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| 58 | // unique_ptr. std::optional<unique_ptr<vfs::File>&> might be nicer, but |
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| 59 | // Optional needs some work to support references so this isn't possible yet. |
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| 60 | virtual std::error_code getStat(StringRef Path, llvm::vfs::Status &Status, |
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| 61 | bool isFile, |
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| 62 | std::unique_ptr<llvm::vfs::File> *F, |
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| 63 | llvm::vfs::FileSystem &FS) = 0; |
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| 64 | }; |
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| 65 | |||
| 66 | /// A stat "cache" that can be used by FileManager to keep |
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| 67 | /// track of the results of stat() calls that occur throughout the |
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| 68 | /// execution of the front end. |
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| 69 | class MemorizeStatCalls : public FileSystemStatCache { |
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| 70 | public: |
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| 71 | /// The set of stat() calls that have been seen. |
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| 72 | llvm::StringMap<llvm::vfs::Status, llvm::BumpPtrAllocator> StatCalls; |
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| 73 | |||
| 74 | using iterator = |
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| 75 | llvm::StringMap<llvm::vfs::Status, |
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| 76 | llvm::BumpPtrAllocator>::const_iterator; |
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| 77 | |||
| 78 | iterator begin() const { return StatCalls.begin(); } |
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| 79 | iterator end() const { return StatCalls.end(); } |
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| 80 | |||
| 81 | std::error_code getStat(StringRef Path, llvm::vfs::Status &Status, |
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| 82 | bool isFile, |
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| 83 | std::unique_ptr<llvm::vfs::File> *F, |
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| 84 | llvm::vfs::FileSystem &FS) override; |
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| 85 | }; |
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| 86 | |||
| 87 | } // namespace clang |
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| 88 | |||
| 89 | #endif // LLVM_CLANG_BASIC_FILESYSTEMSTATCACHE_H |