#!/bin/sh

usage() {
	echo "Usage: ${0##*/} DIR1 DIR2"
	echo
	echo "Compares all object files recursivelty found in DIR1 and DIR2."
	echo "Prints diff of their disassembly."
	echo
	exit $1
}

filter() {
	# sed removes " address: " prefixes which mess up diff
	sed $'s/^\\(\t*\\)[ ]*[0-9a-f][0-9a-f]*:[ \t]*/\\1/' \
	| sed 's/__GI_//g'
}

test -d "$1" || usage 1
test -d "$2" || usage 1

{
	(
		cd "$1" || exit 1
		find -name '*.o' # -o -name '*.os' # -o -name '*.so'
	)
	(
		cd "$2" || exit 1
		find -name '*.o' # -o -name '*.os' # -o -name '*.so'
	)
} | sed 's:^\./::' | sort | uniq | \
(
while IFS='' read -r oname; do
	if ! test -f "$1/$oname"; then
		echo "Only $2/$oname"
		continue
	fi
	if ! test -f "$2/$oname"; then
		echo "Only $1/$oname"
		continue
	fi
	diff -q -- "$1/$oname" "$2/$oname" >/dev/null && continue
	(cd "$1" && { size "$oname"; objdump -dr "$oname" | filter; } >"$oname.disasm")
	(cd "$2" && { size "$oname"; objdump -dr "$oname" | filter; } >"$oname.disasm")
	diff -u -- "$1/$oname.disasm" "$2/$oname.disasm"
done
)