#!/bin/bash
#
# Copyright (C) 2006-2007 Daniel Holbach <daniel.holbach@ubuntu.com>
# Modified by Siegfried-A. Gevatter <rainct@ubuntu.com>
#
# ##################################################################
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# See file /usr/share/common-licenses/GPL-2 for more details.
#
# ##################################################################
#
# This script is used to get a diff of the exported symbols of all .so files in
# every binary package of package $1.

# Required tools (besides awk, coreutils, grep and sed):
# * apt-cache and apt-get (from apt)
# * diff (from diffutils)
# * dpkg
# * lsb_release (from lsb-release)
# * nm (from binutils)

DISTRO=$(lsb_release -c -s)
DEBLINE=""
DEBUG=False

usage() {
    prog=$(basename $0)
    cat <<EOF
Usage: $prog [options] source-package [DEBDIR]

Get a diff of the exported symbols of all .so files in every binary package of
package the source package. The source package will be found in DEBDIR, defaulting to /var/cache/pbuilder/result.

Options:
  -h, --help  show this help message and exit
EOF
    exit $1
}

PACKAGE=""
DEBDIR="/var/cache/pbuilder/result"
POSITION=0
while [ $# -gt 0 ]; do
    case "$1" in
        -h|--help)
            usage 0
            ;;
        -*)
            usage 1
            ;;
        *)
            if [ $POSITION -eq 0 ]; then
                PACKAGE="$1"
            elif [ $POSITION -eq 1 ]; then
                DEBDIR="$1"
            else
                echo "Too many arguments." >&2
                usage 1
            fi
            POSITION=$(($POSITION+1))
    esac
    shift
done

if [ $POSITION -eq 0 ]; then
    echo "Missing argument: source package name." >&2
    usage 1
fi

VERSION=$(apt-cache madison "$PACKAGE" | grep -- "$DISTRO"'/.*Sources$' | awk '{print $3}')
PACKAGES=$(apt-cache showsrc "$PACKAGE" | grep-dctrl -s Binary -F Version "$VERSION" | sed 's/Binary\:\ //g;s/\,//g' | sort -u)

if [ `id -u` != "0" ]
then
    echo
    echo -n "You might now be asked for your password, as this script requires"
    echo " sudo privilegies in order to install the packages you want to check."
    echo
fi

sudo apt-get install $PACKAGES
echo

for pack in $PACKAGES;
do
    for lib in `dpkg -L $pack | grep -E "\.so$" | sort -u`
    do
        LIBNAME=$(basename $lib)
        nm -D $lib | cut -d' ' -f3 | sort -u > /tmp/$LIBNAME.old
    done;
    DEBLINE="$DEBLINE $DEBDIR/$pack*.deb "
done

if [[ -z $DEBLINE ]]; then
    echo "Package doesn't exist: $PACKAGE."
    exit 1
fi

NOFILE=True
for filename in $DEBLINE; do
    if [[ ${filename: -5} != "*.deb" ]]; then
        NOFILE=False
        [[ $DEBUG != True ]] || echo "Found binary file: $filename"
    fi
done

if [[ $NOFILE == True ]]; then
    echo "No matching binary files found in «$DEBDIR»."
    exit 1
fi

sudo dpkg -i $DEBLINE;
echo

for pack in $PACKAGES;
do
    for lib in `dpkg -L $pack | grep -E "\.so$" | sort -u`
    do
        LIBNAME=$(basename $lib)
        nm -D $lib | cut -d' ' -f3 | sort -u > /tmp/$LIBNAME.new
        echo "Checking: $lib"
        diff -u /tmp/$LIBNAME.{old,new}
        rm /tmp/$LIBNAME.{old,new}
    done;
done