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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef SUPPORT_EXCEPTION_SAFETY_HELPERS_H
10#define SUPPORT_EXCEPTION_SAFETY_HELPERS_H
11
12#include <cassert>
13#include <cstddef>
14#include <functional>
15#include <utility>
16#include "test_macros.h"
17
18#if !defined(TEST_HAS_NO_EXCEPTIONS)
19template <int N>
20struct ThrowingCopy {
21 static bool throwing_enabled;
22 static int created_by_copying;
23 static int destroyed;
24 int x = 0; // Allows distinguishing between different instances.
25
26 ThrowingCopy() = default;
27 ThrowingCopy(int value) : x(value) {}
28 ~ThrowingCopy() {
29 ++destroyed;
30 }
31
32 ThrowingCopy(const ThrowingCopy& other) : x(other.x) {
33 ++created_by_copying;
34 if (throwing_enabled && created_by_copying == N) {
35 throw -1;
36 }
37 }
38
39 // Defined to silence GCC warnings. For test purposes, only copy construction is considered `created_by_copying`.
40 ThrowingCopy& operator=(const ThrowingCopy& other) {
41 x = other.x;
42 return *this;
43 }
44
45 friend bool operator==(const ThrowingCopy& lhs, const ThrowingCopy& rhs) { return lhs.x == rhs.x; }
46 friend bool operator<(const ThrowingCopy& lhs, const ThrowingCopy& rhs) { return lhs.x < rhs.x; }
47
48 static void reset() {
49 created_by_copying = destroyed = 0;
50 }
51};
52
53template <int N>
54bool ThrowingCopy<N>::throwing_enabled = true;
55template <int N>
56int ThrowingCopy<N>::created_by_copying = 0;
57template <int N>
58int ThrowingCopy<N>::destroyed = 0;
59
60template <int N>
61struct std::hash<ThrowingCopy<N>> {
62 std::size_t operator()(const ThrowingCopy<N>& value) const {
63 return value.x;
64 }
65};
66
67template <int ThrowOn, int Size, class Func>
68void test_exception_safety_throwing_copy(Func&& func) {
69 using T = ThrowingCopy<ThrowOn>;
70 T::reset();
71 T in[Size];
72
73 try {
74 func(in, in + Size);
75 assert(false); // The function call above should throw.
76
77 } catch (int) {
78 assert(T::created_by_copying == ThrowOn);
79 assert(T::destroyed == ThrowOn - 1); // No destructor call for the partially-constructed element.
80 }
81}
82
83// Destroys the container outside the user callback to avoid destroying extra elements upon throwing (which would
84// complicate asserting that the expected number of elements was destroyed).
85template <class Container, int ThrowOn, int Size, class Func>
86void test_exception_safety_throwing_copy_container(Func&& func) {
87 using T = ThrowingCopy<ThrowOn>;
88 T::throwing_enabled = false;
89 T in[Size];
90 Container c(in, in + Size);
91 T::throwing_enabled = true;
92 T::reset();
93
94 try {
95 func(std::move(c));
96 assert(false); // The function call above should throw.
97
98 } catch (int) {
99 assert(T::created_by_copying == ThrowOn);
100 assert(T::destroyed == ThrowOn - 1); // No destructor call for the partially-constructed element.
101 }
102}
103
104#endif // !defined(TEST_HAS_NO_EXCEPTIONS)
105
106#endif // SUPPORT_EXCEPTION_SAFETY_HELPERS_H
107

source code of libcxx/test/std/containers/exception_safety_helpers.h