core-lightning/common/overflows.h
Rusty Russell 8c22bd9ee1 headers: fix up header idempotent lines.
For future reference, done via:
	for f in `find wire/ bitcoin/ common/ lightningd -name '*.h' ! -name 'gen*'`; do ID=`echo -n LIGHTNING/$f | tr 'a-z' 'A-Z' | tr -cs 'A-Z0-9' _`; sed 's/^#\(ifndef\|define\) .*_H$/#\1 '$ID/ < $f | sed 's,#endif /..*_H ./$,#endif /* '$ID' */,' | bagto $f; done

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

35 lines
652 B
C

#ifndef LIGHTNING_COMMON_OVERFLOWS_H
#define LIGHTNING_COMMON_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_COMMON_OVERFLOWS_H */