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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef SUPPORT_EXCEPTION_SAFETY_HELPERS_H10#define SUPPORT_EXCEPTION_SAFETY_HELPERS_H11 12#include <cassert>13#include <cstddef>14#include <forward_list>15#include <functional>16#include <utility>17#include "test_macros.h"18 19#if !defined(TEST_HAS_NO_EXCEPTIONS)20template <int N>21struct ThrowingCopy {22 static bool throwing_enabled;23 static int created_by_copying;24 static int destroyed;25 int x = 0; // Allows distinguishing between different instances.26 27 ThrowingCopy() = default;28 ThrowingCopy(int value) : x(value) {}29 ~ThrowingCopy() { ++destroyed; }30 31 ThrowingCopy(const ThrowingCopy& other) : x(other.x) {32 ++created_by_copying;33 if (throwing_enabled && created_by_copying == N) {34 throw -1;35 }36 }37 38 // Defined to silence GCC warnings. For test purposes, only copy construction is considered `created_by_copying`.39 ThrowingCopy& operator=(const ThrowingCopy& other) {40 x = other.x;41 return *this;42 }43 44 friend bool operator==(const ThrowingCopy& lhs, const ThrowingCopy& rhs) { return lhs.x == rhs.x; }45 friend bool operator<(const ThrowingCopy& lhs, const ThrowingCopy& rhs) { return lhs.x < rhs.x; }46 47 static void reset() { created_by_copying = destroyed = 0; }48};49 50template <int N>51bool ThrowingCopy<N>::throwing_enabled = true;52template <int N>53int ThrowingCopy<N>::created_by_copying = 0;54template <int N>55int ThrowingCopy<N>::destroyed = 0;56 57template <int N>58struct ThrowingDefault {59 static bool throwing_enabled;60 static int default_constructed;61 static int destroyed;62 int x = 0;63 64 ThrowingDefault() {65 ++default_constructed;66 if (throwing_enabled && default_constructed == N) {67 throw -1;68 }69 }70 71 ThrowingDefault(int value) : x(value) {}72 ThrowingDefault(const ThrowingDefault& other) = default;73 friend bool operator==(const ThrowingDefault& lhs, const ThrowingDefault& rhs) { return lhs.x == rhs.x; }74 friend bool operator<(const ThrowingDefault& lhs, const ThrowingDefault& rhs) { return lhs.x < rhs.x; }75 76 static void reset() { default_constructed = destroyed = 0; }77};78 79template <int N>80bool ThrowingDefault<N>::throwing_enabled = true;81template <int N>82int ThrowingDefault<N>::default_constructed = 0;83 84template <int N>85struct std::hash<ThrowingCopy<N>> {86 std::size_t operator()(const ThrowingCopy<N>& value) const { return value.x; }87};88 89template <int ThrowOn, int Size, class Func>90void test_exception_safety_throwing_copy(Func&& func) {91 using T = ThrowingCopy<ThrowOn>;92 T::reset();93 T in[Size];94 95 try {96 func(in, in + Size);97 assert(false); // The function call above should throw.98 99 } catch (int) {100 assert(T::created_by_copying == ThrowOn);101 assert(T::destroyed == ThrowOn - 1); // No destructor call for the partially-constructed element.102 }103}104 105// Destroys the container outside the user callback to avoid destroying extra elements upon throwing (which would106// complicate asserting that the expected number of elements was destroyed).107template <class Container, int ThrowOn, int Size, class Func>108void test_exception_safety_throwing_copy_container(Func&& func) {109 using T = ThrowingCopy<ThrowOn>;110 T::throwing_enabled = false;111 T in[Size];112 Container c(in, in + Size);113 T::throwing_enabled = true;114 T::reset();115 116 try {117 func(std::move(c));118 assert(false); // The function call above should throw.119 120 } catch (int) {121 assert(T::created_by_copying == ThrowOn);122 assert(T::destroyed == ThrowOn - 1); // No destructor call for the partially-constructed element.123 }124}125 126template <int ThrowOn, int Size, class Func>127void test_strong_exception_safety_throwing_copy(Func&& func) {128 using T = ThrowingCopy<ThrowOn>;129 T::throwing_enabled = false;130 131 std::forward_list<T> c0(Size);132 for (int i = 0; i < Size; ++i)133 c0.emplace_front(i);134 std::forward_list<T> c = c0;135 T in[Size];136 T::reset();137 T::throwing_enabled = true;138 try {139 func(c, in, in + Size);140 assert(false); // The function call above should throw.141 142 } catch (int) {143 assert(T::created_by_copying == ThrowOn);144 assert(T::destroyed == ThrowOn - 1); // No destructor call for the partially-constructed element.145 assert(c == c0); // Strong exception guarantee146 }147}148 149#endif // !defined(TEST_HAS_NO_EXCEPTIONS)150 151#endif // SUPPORT_EXCEPTION_SAFETY_HELPERS_H152