- //===- llvm/Support/FileSystem/UniqueID.h - UniqueID for files --*- 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 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file is cut out of llvm/Support/FileSystem.h to allow UniqueID to be 
- // reused without bloating the includes. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_SUPPORT_FILESYSTEM_UNIQUEID_H 
- #define LLVM_SUPPORT_FILESYSTEM_UNIQUEID_H 
-   
- #include "llvm/ADT/DenseMapInfo.h" 
- #include "llvm/ADT/Hashing.h" 
- #include <cstdint> 
- #include <utility> 
-   
- namespace llvm { 
- namespace sys { 
- namespace fs { 
-   
- class UniqueID { 
-   uint64_t Device; 
-   uint64_t File; 
-   
- public: 
-   UniqueID() = default; 
-   UniqueID(uint64_t Device, uint64_t File) : Device(Device), File(File) {} 
-   
-   bool operator==(const UniqueID &Other) const { 
-     return Device == Other.Device && File == Other.File; 
-   } 
-   bool operator!=(const UniqueID &Other) const { return !(*this == Other); } 
-   bool operator<(const UniqueID &Other) const { 
-     /// Don't use std::tie since it bloats the compile time of this header. 
-     if (Device < Other.Device) 
-       return true; 
-     if (Other.Device < Device) 
-       return false; 
-     return File < Other.File; 
-   } 
-   
-   uint64_t getDevice() const { return Device; } 
-   uint64_t getFile() const { return File; } 
- }; 
-   
- } // end namespace fs 
- } // end namespace sys 
-   
- // Support UniqueIDs as DenseMap keys. 
- template <> struct DenseMapInfo<llvm::sys::fs::UniqueID> { 
-   static inline llvm::sys::fs::UniqueID getEmptyKey() { 
-     auto EmptyKey = DenseMapInfo<std::pair<uint64_t, uint64_t>>::getEmptyKey(); 
-     return {EmptyKey.first, EmptyKey.second}; 
-   } 
-   
-   static inline llvm::sys::fs::UniqueID getTombstoneKey() { 
-     auto TombstoneKey = 
-         DenseMapInfo<std::pair<uint64_t, uint64_t>>::getTombstoneKey(); 
-     return {TombstoneKey.first, TombstoneKey.second}; 
-   } 
-   
-   static hash_code getHashValue(const llvm::sys::fs::UniqueID &Tag) { 
-     return hash_value(std::make_pair(Tag.getDevice(), Tag.getFile())); 
-   } 
-   
-   static bool isEqual(const llvm::sys::fs::UniqueID &LHS, 
-                       const llvm::sys::fs::UniqueID &RHS) { 
-     return LHS == RHS; 
-   } 
- }; 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_SUPPORT_FILESYSTEM_UNIQUEID_H 
-