append_buf
append_buf("<%s> [%u] %s %s",
append_buf(fmt_str, s, e->val);
append_buf(fmt_str, s, (unsigned long long)btf_enum64_value(e));
append_buf(".%s", spec->spec[i].name);
append_buf("[%u]", spec->spec[i].idx);
append_buf(" (");
append_buf("%s%d", i == 0 ? "" : ":", spec->raw_spec[i]);
append_buf(" @ offset %u.%u)", spec->bit_offset / 8, spec->bit_offset % 8);
append_buf(" @ offset %u)", spec->bit_offset / 8);