#ifndef _OS_OVERFLOW_H
#define _OS_OVERFLOW_H
#include <sys/cdefs.h>
#include <stdbool.h>
#include <os/base.h>
bool __header_always_inline OS_WARN_RESULT
__os_warn_unused(__const bool x)
{
return x;
}
#if __has_builtin(__builtin_add_overflow) && \
__has_builtin(__builtin_sub_overflow) && \
__has_builtin(__builtin_mul_overflow)
#define os_add_overflow(a, b, res) __os_warn_unused(__builtin_add_overflow((a), (b), (res)))
#define os_sub_overflow(a, b, res) __os_warn_unused(__builtin_sub_overflow((a), (b), (res)))
#define os_mul_overflow(a, b, res) __os_warn_unused(__builtin_mul_overflow((a), (b), (res)))
#else
#ifdef __cplusplus
#define __OS_TYPE_CHECK(x, y) do { \
__typeof__(x) _x; \
__typeof__(y) _y; \
(void)(&_x == &_y, "overflow arithmetic: incompatible types"); \
} while (0)
#else
#define __OS_TYPE_CHECK(x, y) do { \
_Static_assert(__builtin_types_compatible_p(__typeof(x),__typeof(y)), \
"overflow arithmetic: incompatible types"); \
} while (0)
#endif
#define __os_add_overflow_func(T,U,V) _Generic((T), \
unsigned: __builtin_uadd_overflow, \
unsigned long: __builtin_uaddl_overflow, \
unsigned long long: __builtin_uaddll_overflow, \
int: __builtin_sadd_overflow, \
long: __builtin_saddl_overflow, \
long long: __builtin_saddll_overflow \
)(T,U,V)
#define __os_sub_overflow_func(T,U,V) _Generic((T), \
unsigned: __builtin_usub_overflow, \
unsigned long: __builtin_usubl_overflow, \
unsigned long long: __builtin_usubll_overflow, \
int: __builtin_ssub_overflow, \
long: __builtin_ssubl_overflow, \
long long: __builtin_ssubll_overflow \
)(T,U,V)
#define __os_mul_overflow_func(T,U,V) _Generic((T), \
unsigned: __builtin_umul_overflow, \
unsigned long: __builtin_umull_overflow, \
unsigned long long: __builtin_umulll_overflow, \
int: __builtin_smul_overflow, \
long: __builtin_smull_overflow, \
long long: __builtin_smulll_overflow \
)(T,U,V)
#define os_add_overflow(a, b, res) __os_warn_unused(__extension__({ \
__OS_TYPE_CHECK((a), (b)); \
__OS_TYPE_CHECK((b), *(res)); \
__os_add_overflow_func((a), (b), (res)); \
}))
#define os_sub_overflow(a, b, res) __os_warn_unused(__extension__({ \
__OS_TYPE_CHECK((a), (b)); \
__OS_TYPE_CHECK((b), *(res)); \
__os_sub_overflow_func((a), (b), (res)); \
}))
#define os_mul_overflow(a, b, res) __os_warn_unused(__extension__({ \
__OS_TYPE_CHECK((a), (b)); \
__OS_TYPE_CHECK((b), *(res)); \
__os_mul_overflow_func((a), (b), (res)); \
}))
#endif
#define os_add3_overflow(a, b, c, res) __os_warn_unused(__extension__({ \
__typeof(*(res)) _tmp; \
bool _s, _t; \
_s = os_add_overflow((a), (b), &_tmp); \
_t = os_add_overflow((c), _tmp, (res)); \
_s | _t; \
}))
#define os_mul3_overflow(a, b, c, res) __os_warn_unused(__extension__({ \
__typeof(*(res)) _tmp; \
bool _s, _t; \
_s = os_mul_overflow((a), (b), &_tmp); \
_t = os_mul_overflow((c), _tmp, (res)); \
_s | _t; \
}))
#define os_add_and_mul_overflow(a, b, x, res) __os_warn_unused(__extension__({ \
__typeof(*(res)) _tmp; \
bool _s, _t; \
_s = os_add_overflow((a), (b), &_tmp); \
_t = os_mul_overflow((x), _tmp, (res)); \
_s | _t; \
}))
#define os_mul_and_add_overflow(a, x, b, res) __os_warn_unused(__extension__({ \
__typeof(*(res)) _tmp; \
bool _s, _t; \
_s = os_mul_overflow((a), (x), &_tmp); \
_t = os_add_overflow((b), _tmp, (res)); \
_s | _t; \
}))
#define os_convert_overflow(a, res) os_add_overflow((a), 0, (res))
#endif