core-lightning/common/overflows.h
Rusty Russell 85ff95e829 common: new directory for any shared objects.
To avoid everything pulling in HTLCs stuff to the opening daemon, we
split the channel and commit_tx routines into initial_channel and
initial_commit_tx (no HTLC support) and move full HTLC supporting versions
into channeld.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2017-08-29 17:54:14 +02:00

35 lines
631 B
C

#ifndef LIGHTNING_OVERFLOWS_H
#define LIGHTNING_OVERFLOWS_H
#include "config.h"
static inline bool add_overflows_size_t(uint64_t a, uint64_t b)
{
return (size_t)a != a || (size_t)b != b || (a + b) < (size_t)a;
}
static inline bool add_overflows_u64(uint64_t a, uint64_t b)
{
return (a + b) < a;
}
static inline bool mul_overflows_s64(int64_t a, int64_t b)
{
int64_t ret;
if (a == 0)
return false;
ret = a * b;
return (ret / a != b);
}
static inline bool mul_overflows_u64(uint64_t a, uint64_t b)
{
uint64_t ret;
if (a == 0)
return false;
ret = a * b;
return (ret / a != b);
}
#endif /* LIGHTNING_OVERFLOWS_H */