#!/bin/sh

##
# Find mach-O executables and:
# - update the install_name of dependent Mach-O libraries.
#
# $Id$
#
# Copyright (c) 2002 Wilfredo Sanchez Vega, wsanchez@mit.edu.
# All rights reserved.
#
# Permission to use, copy, modify, and distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice, this permission, and the following
# disclaimer notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
# AUTHORS BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
# WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
##

# Be strict
set -u
set -e

##
# Functions
##

#
# Command line usage information
#
usage ()
{
    echo "Usage: $(basename $0) [-L <dir>] ... <file_or_dir> ...";
    echo "Options: -L add <dir> to search path for dependent libraries";
    exit 1;
}

#
# Find files by type
# Arguments:
#  $1 : a type string to match
#  $2 : a file mode string (see chmod(3), may be empty)
#  $3+: a list of targets
#
find_file_of_type ()
{
    match="$1"; shift;
     mode="$1"; shift;

    if [ -n "${mode}" ]; then mode="-perm +${mode}"; fi;

    for dir; do
        for file in $(find "${dir}" -type f ${mode}); do
            if file "${file}" | egrep ": ${match}" > /dev/null; then
                echo "${file}";
            fi;
        done;
    done;
}

#
# Shortcuts for find_file_of_type()
#
find_macho_executables () { find_file_of_type 'Mach-O executable'                                     '+x' "$@"; }
find_macho_dylibs      () { find_file_of_type 'Mach-O dynamically linked shared library'              ''   "$@"; }
find_macho_files       () { find_file_of_type 'Mach-O (executable|dynamically linked shared library)' ''   "$@"; }

#
# Given a file, list its dependencies.
#
macho_deps ()
{
    otool -L "$1" | grep '^	' | sed -e 's|^	\(.*\) (compatibility version.*|\1|';
}

#
# For each argument, find all Mach-O files if the argument is a
#  directory or verify that the argument is a Mach-O file if the
#  argument is a file.
# Then proceed to update the dependencies in the file and, if the file
#  is a shared library, update the file's install_name.
#
fix_macho_deps ()
{
    for file in $(find_macho_files "$@"); do

        # If ${file} is a library, update its install_name
        for lib in $(find_macho_dylibs "${file}"); do
                 dirname=$(cd $(dirname "${lib}") && pwd);
                basename=$(basename "${lib}");
                    path="${dirname}/${basename}";
            install_name=$(macho_deps "${path}" | head -1);

            if [ "${install_name}" != "${path}" ]; then
                echo "${lib}: updating install_name";
                install_name_tool -id "${path}" "${path}";
            fi;
        done;

        # Update dependencies
        for dep in $(macho_deps "${file}"); do
            if [ ! -f "${dep}" ]; then
                basename=$(basename "${dep}");

                if ! path=$(grep "${basename}$" "${LibrariesCache}" | head -1); then
                    echo "Can't locate library ${dep} for ${file}";
                else
                    echo "${file}: updating path to ${basename}";

                    install_name_tool -change "${dep}" "${path}" "${file}";
                fi;
            fi;
        done;

    done;
}

##
# Handle command line
##

LibrariesCache=$(mktemp -t $(basename $0));

if ! args=$(getopt L: "$@"); then usage; fi;
set -- ${args};
for option; do
    case "${option}" in
      -L)
        dir="$2";
        if [ ! -d "${dir}" ]; then echo "${dir}: not a directory"; exit 1; fi;
        dir=$(cd "${dir}" && pwd);
        find_macho_dylibs "${dir}" >> "${LibrariesCache}";
        shift 2;
        ;;
      --)
        shift;
        break;
        ;;
    esac;
done;

##
# Do The Right Thing
##

fix_macho_deps "$@";

rm -f "${LibrariesCache}";