1 //===-- SaveAndRestore.h - Utility -------------------------------*- C++ -*-=// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file provides utility classes that uses RAII to save and restore 11 // values. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_ANALYSIS_SAVERESTORE 16 #define LLVM_CLANG_ANALYSIS_SAVERESTORE 17 18 namespace clang { 19 20 // SaveAndRestore - A utility class that uses RAII to save and restore 21 // the value of a variable. 22 template<typename T> 23 struct SaveAndRestore { 24 SaveAndRestore(T& x) : X(x), old_value(x) {} 25 SaveAndRestore(T& x, const T &new_value) : X(x), old_value(x) { 26 X = new_value; 27 } 28 ~SaveAndRestore() { X = old_value; } 29 T get() { return old_value; } 30 private: 31 T& X; 32 T old_value; 33 }; 34 35 // SaveOr - Similar to SaveAndRestore. Operates only on bools; the old 36 // value of a variable is saved, and during the dstor the old value is 37 // or'ed with the new value. 38 struct SaveOr { 39 SaveOr(bool& x) : X(x), old_value(x) { x = false; } 40 ~SaveOr() { X |= old_value; } 41 private: 42 bool& X; 43 const bool old_value; 44 }; 45 46 } 47 #endif 48
