diff options
| -rw-r--r-- | unpack.c | 16 |
1 files changed, 13 insertions, 3 deletions
@@ -1,5 +1,5 @@ /* - * Copyright (C) 2020 Tomasz Kramkowski <tk@the-tk.com> + * Copyright (C) 2020-2021 Tomasz Kramkowski <tk@the-tk.com> * SPDX-License-Identifier: MIT */ #include <ctype.h> @@ -60,6 +60,16 @@ static uintmax_t read_val(const unsigned char *buf, size_t size, enum endian e) return val; } +static intmax_t minval(size_t s) +{ + switch (s) { + case 1: return INTMAX_C(-128); + case 2: return INTMAX_C(-32768); + case 4: return INTMAX_C(-2147483648); + default: return -INTMAX_C(9223372036854775807) - 1; + } +} + enum pack_status unpack(const void *buf_, size_t size, const char *fmt, ...) { enum endian endianness = BIG; @@ -151,8 +161,8 @@ enum pack_status unpack(const void *buf_, size_t size, const char *fmt, ...) if (!(val.u & (UINTMAX_C(1) << (s * 8 - 1)))) { vals = val.u; } else { - uintmax_t offt = BITMASK(s * 8); - vals = val.u - offt - 1; + vals = minval(s); + vals += val.u ^ (UINTMAX_C(1) << (s * 8 - 1)); } val.s = vals; tr_debug("val.s: %" PRIdMAX, val.s); |