#!/bin/bash
#
# Library dependency check script inspired by revdep-rebuild of Gentoo Linux
#
# Christoph Niethammer <niethammer@hlrs.de> (C) 2011
#
 
declare -r APP_NAME="${0##*/}"
declare -r VERSION="0.1"
declare -r FILES_FILE=1_files.rr
declare -r BROKEN_FILE=2_broken.rr
declare findMask
declare MODULE_NAMES
declare SEARCH_DIRS


# extract path information from module file
find_paths() {
    local pathspec=$1
    local PATHS=$( module display $MODULE_NAME |& awk "/.*path[[:space:]]+$pathspec[[:space:]]+/{ sub(/.*path[[:space:]]+$pathspec[[:space:]]+/,\"\"); print }" )
    for path in $PATHS; do 
        SEARCH_DIRS+="$path "
    done
}



function print_usage {

binary=`basename $0`
cat <<EOF
${APP_NAME}: (${VERSION})

Copyright (C) 2011 Christoph Niethammer <niethammer@hlrs.de>

Usage: $APP_NAME MODULE

-h, --help       Print this usage

Checks linking consistency of given modules.

EOF
}



##############################################################################
# MAIN
##############################################################################

if [ $# -lt 1 ]; then
    print_usage
    exit 0
fi

for arg in $@; do
    case $arg in
        --help|-h)
            print_usage
            exit 0
            ;;
        *)
            MODULE_NAMES+="${IFS}${arg}"
            ;;
    esac
done



for MODULE_NAME in $MODULE_NAMES; do
    find_paths PATH
    find_paths LD_LIBRARY_PATH
done

echo "SEARCH_DIRS=$SEARCH_DIRS"

find ${SEARCH_DIRS[@]} $findMask -type f \( -perm -u+x -o -perm -g+x -o -perm -o+x -o \
    -name '*.so' -o -name '*.so.*' -o -name '*.la' \) -print 2> /dev/null |
    sort -u > "$FILES_FILE"

files=($(<"$FILES_FILE"))

for target_file in "${files[@]}"; do
    if ! file $target_file | grep ELF > /dev/null ; then 
        continue
    fi
    if [[ $target_file != *.la ]]; then
        ldd_output=$(ldd "$target_file" 2> /dev/null)
        MISSING_LIBS=$(
            expr='s/[[:space:]]*\([^[:space:]]*\) => not found/\1/p'
            sed -n "$expr" <<< "$ldd_output"
        )
        REQUIRED_LIBS=$(
            expr='s/^[[:space:]]*NEEDED[[:space:]]*\([^[:space:]]*\).*/\1/p';
            objdump -x "$target_file" | grep NEEDED | sed "$expr" | sort -u
        )
        MISSING_LIBS=$(grep -F "$REQUIRED_LIBS" <<< "$MISSING_LIBS")

        if [[ $MISSING_LIBS ]]; then
            echo "obj $target_file" >> "$BROKEN_FILE"
            echo "  broken $target_file (requires $MISSING_LIBS)"
        fi
    fi
done