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e6615b1034
This adds macros for checked addition, subtraction, and multiplication with semantics similar to the builtins gcc and clang have had for years. Reviewed by: kib, emaste Differential Revision: https://reviews.freebsd.org/D41734
41 lines
1.0 KiB
C
41 lines
1.0 KiB
C
/*-
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* Copyright (c) 2023 Dag-Erling Smørgrav
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#ifndef __STDC_VERSION_STDCKDINT_H__
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#define __STDC_VERSION_STDCKDINT_H__ 202311L
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#include <sys/cdefs.h>
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#if __BSD_VISIBLE || __ISO_C_VISIBLE >= 2023
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#if __GNUC_PREREQ__(5, 1) || __has_builtin(__builtin_add_overflow)
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#define ckd_add(result, a, b) \
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(_Bool)__builtin_add_overflow((a), (b), (result))
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#else
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#define ckd_add(result, a, b) \
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_Static_assert(0, "checked addition not supported")
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#endif
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#if __GNUC_PREREQ__(5, 1) || __has_builtin(__builtin_sub_overflow)
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#define ckd_sub(result, a, b) \
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(_Bool)__builtin_sub_overflow((a), (b), (result))
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#else
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#define ckd_sub(result, a, b) \
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_Static_assert(0, "checked subtraction not supported")
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#endif
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#if __GNUC_PREREQ__(5, 1) || __has_builtin(__builtin_mul_overflow)
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#define ckd_mul(result, a, b) \
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(_Bool)__builtin_mul_overflow((a), (b), (result))
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#else
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#define ckd_mul(result, a, b) \
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_Static_assert(0, "checked multiplication not supported")
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#endif
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#endif
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#endif
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