#!/bin/bash

# This script will populate the root directory with libs from the sysroot.
# (C) 2007 Yann E. MORIN
# Licensed under the GPL v2

# Detect where the toolchain is:
BIN_DIR="$(cd "$(dirname "$0")"; pwd)"
CT_READELF="${BIN_DIR}/@@CT_TARGET@@-readelf"
CT_SYSROOT_DIR="${BIN_DIR}/../@@CT_TARGET@@/sys-root"

myname=$(basename "$0")

doHelp() {
    cat <<_EOF_
NAME
    $myname - populate the target root file system

SYNOPSIS
    $myname OPTIONS -s source_root -d destination_root

DESCRIPTION
    $myname will 'populate' your target root file system ('src_dir') with
    libraries from the toolchain (eg. libc.so...), storing the result into
    'dst_dir'.

OPTIONS
    -s src_dir
        use 'src_dir' as the un-populated (source) root directory

    -d dst_dir
        use 'dst_dir' as the place to put the populated root directory

    -l name1[:name2[...]]
        Always add the specified shared library/ies name1, name2... from the
        toolchain (in the sys-root). Actual library names are searched as
        follows (where 'name' is replaced with the given name) in the
        sys-root directory:
          - libname.so
          - name.so
          - name
        If the file is found, then the SONAME of the library is used, and the
        library is copied with that name. If the library was not found, this
        yields an error (unless -f was given).

    -L file
        Read 'file' for a list of shared libraries to always add from the
        toolchain. The file should contain one library name per line; text
        after a # is ignored until the end of the line; spaces are ignored;
        empty lines are ignored. Libraries are searched for as with -l.

    -f  force execution: if destination directory already exists, it will be
        removed first; if a specified library (above) was not found, continue.

    -v  Be verbose

_EOF_
}

CT_ROOT_SRC_DIR=
CT_ROOT_DST_DIR=
CT_LIB_LIST=
CT_LIB_FILE=
CT_FORCE=no
CT_ECHO=true
while getopts ":s:d:l:L:fvh" CT_OPT; do
    case "${CT_OPT}" in
        s)  CT_ROOT_SRC_DIR="${OPTARG}";;
        d)  CT_ROOT_DST_DIR="${OPTARG}";;
        l)  CT_LIB_LIST="${CT_LIB_LIST}:${OPTARG}";;
        L)  CT_LIB_FILE="${OPTARG}";;
        f)  CT_FORCE=y;;
        v)  CT_ECHO=echo;;
        h)  doHelp
            exit 0
            ;;
        :)  echo "$myname: '-${OPTARG}' takes exactly one argument."
            exit 1
            ;;
        ?)  echo "$myname: unknown option '-${OPTARG}'."
            exit 1
            ;;
    esac
done

# Sanity checks
if [ -z "${CT_ROOT_SRC_DIR}" -o -z "${CT_ROOT_DST_DIR}" ]; then
    doHelp
    exit 1
fi
if [ ! -d "${CT_ROOT_SRC_DIR}" ]; then
    echo "$myname: '${CT_ROOT_SRC_DIR}': no such file or directory"
    exit 1
fi
if [ -d "${CT_ROOT_DST_DIR}" -a "${CT_FORCE}" != "y" ]; then
    echo "$myname: '${CT_ROOT_DST_DIR}': already exists"
    exit 1
fi
src_inode=$(ls -di "${CT_ROOT_SRC_DIR}")
dst_inode=$(ls -di "${CT_ROOT_DST_DIR}" 2>/dev/null)
if [ "${src_inode}" = "${dst_inode}" ]; then
    echo "$myname: source and destination are the same!"
    exit 1
fi

# Check existence of the forced libraries file
if [ -n "${CT_LIB_FILE}" -a ! \( -f "${CT_LIB_FILE}" -a -r "${CT_LIB_FILE}" \) ]; then
    echo "$myname: forced libraries file '${CT_LIB_FILE}' not found!"
    exit 1
fi

# Get rid of potentially older destination directory
if [ -d "${CT_ROOT_DST_DIR}" ]; then
    mv "${CT_ROOT_DST_DIR}" "${CT_ROOT_DST_DIR}.$$"
    setsid nohup rm -rf "${CT_ROOT_DST_DIR}.$$" >/dev/null 2>&1 &
fi

# Create the working copy
mkdir -p "${CT_ROOT_DST_DIR}"

# Make all path absolute
CT_ROOT_SRC_DIR=$(cd "${CT_ROOT_SRC_DIR}"; pwd)
CT_ROOT_DST_DIR=$(cd "${CT_ROOT_DST_DIR}"; pwd)

pushd "${CT_ROOT_SRC_DIR}" >/dev/null
tar cf - . |(cd "${CT_ROOT_DST_DIR}"; tar xf -)
popd >/dev/null

# A function do search for a library
# Usage: do_add_lib libname
# returns: 0 if library was found and added, !0 otherwise
do_add_lib() {
    local libname="$1"
    local ret=1
    local true_libname
    for dir in . usr; do
        ${CT_ECHO} -n "    trying in '${dir}'"
        libfile="${CT_SYSROOT_DIR}/${dir}/lib/${libname}"
        ${CT_ECHO} ": '${libfile}'"
        if [ -e "${libfile}" ]; then
            mkdir -p "${dir}/lib"
            true_libname=$("${CT_READELF}" -d "${libfile}" |egrep "SONAME" |sed -r -e 's,.+\[(.+)\] *$,\1,;')
            ${CT_ECHO} "      installing as '${dir}/lib/${true_libname}'"
            cat "${libfile}" >"${dir}/lib/${true_libname}"
            ret=0
            break
        fi
    done
    return ${ret}
}

# First of, copy the forced libraries into the working copy
if [ -n "${CT_LIB_FILE}" ]; then
    lib_list=$(sed -r -e ':loop; s/#.*//; s/[[:space:]]+//g; s/([^:])$/\1:/; /$/N; s/\n//; tloop;' "${CT_LIB_FILE}")
    CT_LIB_LIST=$(echo "${CT_LIB_LIST}:${lib_list}" |sed -r -e 's/:+/:/g; s/^:+//; s/:+$//;')
fi
CT_LIB_LIST="${CT_LIB_LIST//:/ }"
${CT_ECHO} "Installing forced libraries..."
pushd "${CT_ROOT_DST_DIR}" >/dev/null
for name in ${CT_LIB_LIST}; do
    [ -z "${name}" ] && continue
    found=0
    for libname in "lib${name}.so" "${name}.so" "${name}"; do
        ${CT_ECHO} "  searching for '${libname}'"
        if do_add_lib "${libname}"; then
            found=1
            break
        fi
    done
    if [ ${found} -eq 0 ]; then
        echo "$myname: library '${libname}' not found!"
        [ "${CT_FORCE}" = y ] || exit 1
    fi
done
popd >/dev/null

# Parse the working copy for executables and libraries
pushd "${CT_ROOT_DST_DIR}" >/dev/null
still_needed=1
while [ ${still_needed} -eq 1 ]; do
    ${CT_ECHO} "Looping..."
    still_needed=0
    for f in $(find . -type f -exec file {} \; |egrep ': ELF [[:digit:]]+-bit .SB (executable|shared object),' |cut -d ":" -f 1); do
        ${CT_ECHO} "Scanning '${f}'"
        for libname in $("${CT_READELF}" -d "${f}" |egrep '(NEEDED)' |sed -r -e 's,.+\[(.+)\] *$,\1,;'); do
            ${CT_ECHO} "  searching for '${libname}'"
            if [    -e "lib/${libname}"     \
                 -o -e "usr/lib/${libname}" ]; then
                ${CT_ECHO} "    already present"
                continue
            fi
            if do_add_lib "${libname}"; then
                still_needed=1
            else
                echo "$myname: library '${libname}' not found!"
            fi
        done
    done
done
popd >/dev/null