#!/usr/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# Disassemble a single function.
#
# usage: objdump-func <file> <func>

set -o errexit
set -o nounset

OBJDUMP="${CROSS_COMPILE:-}objdump"

command -v gawk >/dev/null 2>&1 || die "gawk isn't installed"

usage() {
	echo "usage: objdump-func <file> <func>" >&2
	exit 1
}

[[ $# -lt 2 ]] && usage

OBJ=$1; shift
FUNC=$1; shift

# Secret feature to allow adding extra objdump args at the end
EXTRA_ARGS=$@

# Note this also matches compiler-added suffixes like ".cold", etc
${OBJDUMP} -wdr $EXTRA_ARGS $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }'