/src/poppler/goo/GooCheckedOps.h
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1 | | //======================================================================== |
2 | | // |
3 | | // GooCheckedOps.h |
4 | | // |
5 | | // This file is licensed under the GPLv2 or later |
6 | | // |
7 | | // Copyright (C) 2018 Adam Reichold <adam.reichold@t-online.de> |
8 | | // Copyright (C) 2019 LE GARREC Vincent <legarrec.vincent@gmail.com> |
9 | | // Copyright (C) 2019-2021, 2025 Albert Astals Cid <aacid@kde.org> |
10 | | // |
11 | | //======================================================================== |
12 | | |
13 | | #ifndef GOO_CHECKED_OPS_H |
14 | | #define GOO_CHECKED_OPS_H |
15 | | |
16 | | #include <limits> |
17 | | #include <type_traits> |
18 | | |
19 | | template<typename T> |
20 | | inline bool checkedAssign(long long lz, T *z) |
21 | | { |
22 | | static_assert((std::numeric_limits<long long>::max)() > (std::numeric_limits<T>::max)(), "The max of long long type must be larger to perform overflow checks."); |
23 | | static_assert((std::numeric_limits<long long>::min)() < (std::numeric_limits<T>::min)(), "The min of long long type must be smaller to perform overflow checks."); |
24 | | |
25 | | if (lz > (std::numeric_limits<T>::max)() || lz < (std::numeric_limits<T>::min)()) { |
26 | | return true; |
27 | | } |
28 | | |
29 | | *z = static_cast<T>(lz); |
30 | | return false; |
31 | | } |
32 | | |
33 | | #ifndef __has_builtin |
34 | | # define __has_builtin(x) 0 |
35 | | #endif |
36 | | |
37 | | template<typename T> |
38 | | inline bool checkedAdd(T x, T y, T *z) |
39 | 326 | { |
40 | 326 | #if __has_builtin(__builtin_add_overflow) |
41 | 326 | return __builtin_add_overflow(x, y, z); |
42 | | #else |
43 | | const auto lz = static_cast<long long>(x) + static_cast<long long>(y); |
44 | | return checkedAssign(lz, z); |
45 | | #endif |
46 | 326 | } bool checkedAdd<int>(int, int, int*) Line | Count | Source | 39 | 326 | { | 40 | 326 | #if __has_builtin(__builtin_add_overflow) | 41 | 326 | return __builtin_add_overflow(x, y, z); | 42 | | #else | 43 | | const auto lz = static_cast<long long>(x) + static_cast<long long>(y); | 44 | | return checkedAssign(lz, z); | 45 | | #endif | 46 | 326 | } |
Unexecuted instantiation: bool checkedAdd<unsigned int>(unsigned int, unsigned int, unsigned int*) |
47 | | |
48 | | template<> |
49 | | inline bool checkedAdd<long long>(long long x, long long y, long long *z) |
50 | 207k | { |
51 | 207k | #if __has_builtin(__builtin_add_overflow) |
52 | 207k | return __builtin_add_overflow(x, y, z); |
53 | | #else |
54 | | if (x > 0 && y > 0) { |
55 | | if (x > (std::numeric_limits<long long>::max)() - y) { |
56 | | return true; |
57 | | } |
58 | | } else if (x < 0 && y < 0) { |
59 | | if (x < (std::numeric_limits<long long>::min)() - y) { |
60 | | return true; |
61 | | } |
62 | | } |
63 | | *z = x + y; |
64 | | return false; |
65 | | #endif |
66 | 207k | } |
67 | | |
68 | | template<typename T> |
69 | | inline bool checkedSubtraction(T x, T y, T *z) |
70 | 0 | { |
71 | 0 | #if __has_builtin(__builtin_sub_overflow) |
72 | 0 | return __builtin_sub_overflow(x, y, z); |
73 | | #else |
74 | | const auto lz = static_cast<long long>(x) - static_cast<long long>(y); |
75 | | return checkedAssign(lz, z); |
76 | | #endif |
77 | 0 | } |
78 | | |
79 | | template<typename T> |
80 | | inline bool checkedMultiply(T x, T y, T *z) |
81 | 940k | { |
82 | 940k | #if __has_builtin(__builtin_mul_overflow) |
83 | 940k | return __builtin_mul_overflow(x, y, z); |
84 | | #else |
85 | | const auto lz = static_cast<long long>(x) * static_cast<long long>(y); |
86 | | return checkedAssign(lz, z); |
87 | | #endif |
88 | 940k | } bool checkedMultiply<int>(int, int, int*) Line | Count | Source | 81 | 940k | { | 82 | 940k | #if __has_builtin(__builtin_mul_overflow) | 83 | 940k | return __builtin_mul_overflow(x, y, z); | 84 | | #else | 85 | | const auto lz = static_cast<long long>(x) * static_cast<long long>(y); | 86 | | return checkedAssign(lz, z); | 87 | | #endif | 88 | 940k | } |
Unexecuted instantiation: bool checkedMultiply<unsigned int>(unsigned int, unsigned int, unsigned int*) |
89 | | |
90 | | template<> |
91 | | inline bool checkedMultiply<long long>(long long x, long long y, long long *z) |
92 | 0 | { |
93 | 0 | #if __has_builtin(__builtin_mul_overflow) |
94 | 0 | return __builtin_mul_overflow(x, y, z); |
95 | | #else |
96 | | if (x != 0 && (std::numeric_limits<long long>::max)() / x < y) { |
97 | | return true; |
98 | | } |
99 | | |
100 | | *z = x * y; |
101 | | return false; |
102 | | #endif |
103 | 0 | } |
104 | | |
105 | | template<typename T> |
106 | | inline T safeAverage(T a, T b) |
107 | 0 | { |
108 | 0 | static_assert((std::numeric_limits<long long>::max)() > (std::numeric_limits<T>::max)(), "The max of long long type must be larger to perform overflow checks."); |
109 | 0 | static_assert((std::numeric_limits<long long>::min)() < (std::numeric_limits<T>::min)(), "The min of long long type must be smaller to perform overflow checks."); |
110 | |
|
111 | 0 | return static_cast<T>((static_cast<long long>(a) + static_cast<long long>(b)) / 2); |
112 | 0 | } |
113 | | |
114 | | #endif // GOO_CHECKED_OPS_H |