Use objdump to view the differences between two object files

asm-diff

#!/bin/bash
#
# Usage: asm-diff [options] file1 file2 [-- diff options]
#  Return the difference in the objudmp parsing of files
#
# OPTIONS:
#   -o,--objdump CMD --- specify objdump command to use
#   -j,--section NAME -- section to compare
#                        (default: .text)
#   -c,--clean --------- specify whether to clean addresses
#   -C,--really-clean -- specify whether to REALLY clean addresses
#   -f,--fun-clean ----- clean function names
#   -O,--objargs ARGS -- specify objdump args to use
#                        (default --no-show-raw-insn -d)
#                        (for data try -s)
#   -s,--strip --------- strip before comparison
#   -r,--ltrand-strip -- strip lt-rand symbols before comparison
#   -u,--context NUM --- NUM lines of context
#                        (default: 2000)
#   -d,--diffargs ARGS - specify diff args. Overrides context.
#                        (default: -uN)
#                        e.g., "-d '-y'" for side-by-side diff
SCRIPT="$0"
help(){
    local HELP_TEXT=$(cat "$SCRIPT" \
        |sed '/^[^#]/q' \
        |head -n -1 \
        |tail -n +3 \
        |sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' \
        |cut -c3-)
    echo "$HELP_TEXT"
    exit 1
}

OBJDUMP=objdump
OBJDUMP_ARGS="--no-show-raw-insn -d"
SECTION=.text
CLEAN=
FN_CLEAN=
STRIP=
LTRAND_STRIP=
LEFT_STRIP=
RIGHT_STRIP=
CONTEXT=4
DIFF_ARGS="-uN"

eval set -- $(getopt -o ho:j:cCfO:sru:d: -l help,objdump:,section:,clean,really-clean,fun-clean,objargs:,strip,ltrand-strip,context:,diffargs: -- "$@" || help;)
while [ $# -gt 0 ];do
    case $1 in
        -h|--help) help;;
        -o|--objdump) OBJDUMP=$2; shift;;
        -O|--objargs) OBJDUMP_ARGS=$2; shift;;
        -j|--section) SECTION=$2; shift;;
        -c|--clean) CLEAN=yes;;
        -C|--really-clean) CLEAN=REALLY;;
        -f|--fun-clean) FN_CLEAN=yes;;
        -u|--context) CONTEXT=$2; shift;;
        -d|--diffargs) DIFF_ARGS=$2; CONTEXT=""; shift;;
        -s|--strip) STRIP=yes;;
        -r|--ltrand-strip) LTRAND_STRIP=yes;;
        (--) shift; break;;
        (-*) error "unrecognized option $1";;
        (*)  break;;
    esac
    shift
done
if [ -z $1 ] || [ ! -f $1 ] || [ -z $2 ] || [ ! -f $2 ];then
    help
else
    LEFT=$1
    RIGHT=$2
    shift;shift;
fi
if [ ! -z $1 ];then
    DIFF_ARGS=$@
    CONTEXT=""
fi

function exit_hook (){
    if [ -f $LEFT_STRIP ];then
        rm -f $LEFT_STRIP;
    fi
    if [ -f $RIGHT_STRIP ];then
        rm -f $RIGHT_STRIP;
    fi
}
trap exit_hook SIGHUP SIGINT SIGTERM

if [ ! -z $STRIP ] || [ ! -z $LTRAND_STRIP ];then
    LEFT_STRIP=$(mktemp $(basename $LEFT)-XXXXXX.strip)
    RIGHT_STRIP=$(mktemp $(basename $RIGHT)-XXXXXX.strip)
    if [ ! -z $STRIP ];then
        STRIP_ARGS=-s
    fi
    if [ ! -z $LTRAND_STRIP ];then
        STRIP_ARGS=-w --strip-symbol="__ltrand.*"
    fi
    strip $LEFT $STRIP_ARGS -o $LEFT_STRIP
    strip $RIGHT $STRIP_ARGS -o $RIGHT_STRIP
    LEFT=$LEFT_STRIP
    RIGHT=$RIGHT_STRIP
fi

clean(){
    local SED_CMD=''
    if [ ! -z $CLEAN ] || [ ! -z $FN_CLEAN ];then
        SED_CMD+='s/[0-9a-f]\+\([: ]\)/ADDR\1/;'
        SED_CMD+='s/\(callq\|jmp\|jmpq\|jne\|je\|js\)\( *\)[0-9a-f]\+/\1\2ADDR/;'
    fi
    if [ $CLEAN == REALLY ];then
        SED_CMD+='s/[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]/ADDR/g;'
        SED_CMD+='s/0x[0-9a-f][0-9a-f][0-9a-f][0-9a-f](%rip)/0xADDR(%rip)/;'
        SED_CMD+='s/0x[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f](%rip)/0xADDR(%rip)/;'
    fi
    if [ ! -z $FN_CLEAN ];then
        SED_CMD+='s/<[^>]*>/<FUNCTION>/g;'
    fi
    cat -|sed "$SED_CMD"
}

if [ ! -z $CONTEXT ];then
    CONTEXT="-U$CONTEXT"
fi

colordiff $DIFF_ARGS $CONTEXT \
    <($OBJDUMP $OBJDUMP_ARGS -j $SECTION $LEFT|clean) \
    <($OBJDUMP $OBJDUMP_ARGS -j $SECTION $RIGHT|clean) |tail -n+5

exit_hook