radare2/libr/util/uleb128.c
2014-05-19 05:40:45 +04:00

47 lines
801 B
C

#include <r_util.h>
/* dex/dwarf uleb128 implementation */
R_API const ut8 *r_uleb128 (const ut8 *data, ut64 *v) {
ut8 c;
ut64 s, sum = 0;
if (data) {
if (*data) {
for (s = 0; ; s += 7) {
c = *(data++) & 0xff;
sum |= ((ut32) (c&0x7f) << s);
if (!(c&0x80)) break;
}
} else data++;
}
if (v) *v = sum;
return data;
}
R_API const ut8 *r_leb128 (const ut8 *data, st64 *v) {
ut8 c = 0;
st64 s = 0, sum = 0;
if (data) {
for (s = 0; *data;) {
c = *(data++) & 0x0ff;
sum |= ((st64) (c & 0x7f) << s);
s += 7;
if (!(c & 0x80)) break;
}
}
if ((s < (8 * sizeof (sum))) && (c & 0x40)) {
sum |= -((st64)1 << s);
}
if (v) *v = sum;
return data;
}
#if 0
main() {
ut32 n;
ut8 *buf = "\x10\x02\x90\x88";
r_uleb128 (buf, &n);
printf ("n = %d\n", n);
}
#endif