#!/bin/sh

# This script will populate the root directory with libs from the sysroot.

# (C) 2007 Yann E. MORIN

# Licensed under the GPL v2

set -e

# Use the tools discovered by crosstool-NG's ./configure:

install="@@CT_install@@"

grep="@@CT_grep@@"

sed="@@CT_sed@@"

# Detect where the toolchain is:

CT_PREFIX_DIR="$(cd "$(dirname "$0")/.."; pwd)"

CT_GCC="${0%-populate}-gcc"

CT_READELF="${0%-populate}-readelf"

CT_CFG_PREFIX_DIR="$("${CT_GCC}" -v 2>&1            \

                     |tr ' ' '\n'                   \

                     |"${grep}" -E -- '--prefix='   \

                     |cut -d = -f 2-

                    )"

CT_CFG_SYSROOT_DIR="$("${CT_GCC}" -v 2>&1                   \

                      |tr ' ' '\n'                          \

                      |"${grep}" -E -- '--with-sysroot='    \

                      |cut -d = -f 2-

                     )"

CT_SYSROOT_DIR="$(printf "${CT_CFG_SYSROOT_DIR}\n"                              \

                  |"${sed}" -r -e "s:^${CT_CFG_PREFIX_DIR}:${CT_PREFIX_DIR}:;"  \

                  |"${sed}" -r -e 's,/+,/,g;'                                   \

                 )"

myname=$(basename "$0")

doHelp() {

    cat <<_EOF_

NAME

    $myname - populate the target root file system

SYNOPSIS

    $myname OPTIONS -s source_root -d destination_root

DESCRIPTION

    This script will 'populate' your target root file system 'source_root'

    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.

        See the -f and -m options, below, on the required (non-)existence

        of this directory.

    -r sysroot_dir

        Use 'sysroot_dir' as the sysroot instead of the toolchain default.

    -l name1[:name2[...]]

        Always add the specified shared library/ies name1, name2... from the

        toolchain (in the sysroot). Actual library names are searched as

        follows (where 'name' is replaced with the given name) in the

        sysroot 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.

        Note: if using -m and the destination directory already exists, it

        is *not* removed, see below.

    -m  Merge the source root directory with the destination root directory.

        If the latter does not exist, it is created, and -m is ignored.

        If the destination root directory exists, then the content of the

        source root directory is copied in there, and the result is populated

        as usual.

        It can be useful if constructing a rootfs incrementally from many

        smaller source root directories, or if your destination root directory

        is an NFS export that your target mounts as / (and you don't want to

        re-run exportfs -av everytime). USE WITH CARE!

    -v  Be verbose. By default, populate is absolutely silent.

_EOF_

}

CT_ROOT_SRC_DIR=

CT_ROOT_DST_DIR=

CT_LIB_LIST=

CT_LIB_FILE=

CT_MERGE=

CT_FORCE=

CT_PRINTF=:

OPTIND=1

while getopts ":s:d:r:l:L:fmvh" CT_OPT; do

    case "${CT_OPT}" in

        s)  CT_ROOT_SRC_DIR="${OPTARG}";;

        d)  CT_ROOT_DST_DIR="${OPTARG}";;

        r)  CT_SYSROOT_DIR="${OPTARG}";;

        l)  CT_LIB_LIST="${CT_LIB_LIST}:${OPTARG}";;

        L)  CT_LIB_FILE="${OPTARG}";;

        f)  CT_FORCE=y;;

        m)  CT_MERGE=y;;

        v)  CT_PRINTF=printf;;

        h)  doHelp

            exit 0

            ;;

        :)  printf "$myname: '-${OPTARG}' takes exactly one argument.\n"

            exit 1

            ;;

        ?)  printf "$myname: unknown option '-${OPTARG}'.\n"

            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

    printf "$myname: '${CT_ROOT_SRC_DIR}': no such file or directory\n"

    exit 1

fi

if [ ! -d "${CT_SYSROOT_DIR}" ]; then

    printf "$myname: '${CT_SYSROOT_DIR}': no such file or directory\n"

    exit 1

fi

# If the dest dir does not exist, all is well

# If merging, we accept an existing dest directory

# If forcing and not merging, we remove an exiting dest directory

# If not forcing and not merging, we do not accept an exiting dest directory

if [ -d "${CT_ROOT_DST_DIR}" ]; then

    case "${CT_FORCE}:${CT_MERGE}" in

        *:y)    ;;

        y:)     rm -rf "${CT_ROOT_DST_DIR}";;

        :)      printf "$myname: '${CT_ROOT_DST_DIR}': already exists\n"

                exit 1

                ;;

    esac

fi

src_inode=$(ls -1id "${CT_ROOT_SRC_DIR}/." |awk '{ print $1 }')

dst_inode=$(ls -1id "${CT_ROOT_DST_DIR}/." 2>/dev/null |awk '{ print $1 }')

if [ "${src_inode}" -eq "$((dst_inode+0))" ]; then

    printf "$myname: source and destination are the same!\n"

    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

    printf "$myname: forced libraries file '${CT_LIB_FILE}' not found!\n"

    exit 1

fi

# Create the working copy, no issue if already existing

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)

CT_SYSROOT_DIR=$(cd "${CT_SYSROOT_DIR}"; pwd)

# Populate the destination directory with files from the source directory

cd "${CT_ROOT_SRC_DIR}"

cp -a . "${CT_ROOT_DST_DIR}"

cd - >/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 true_libname

    local dir

    local mode

    for dir in lib usr/lib; do

        if [ -e "${dir}/${libname}" ]; then

            ${CT_PRINTF} "    already present\n"

            return 0

        fi

    done

    for dir in lib usr/lib; do

        ${CT_PRINTF} "    trying in '%s'" "${dir}"

        libfile="${CT_SYSROOT_DIR}/${dir}/${libname}"

        ${CT_PRINTF} ": '%s'\n" "${libfile}"

        if [ -e "${libfile}" ]; then

            mkdir -p "${dir}"

            true_libname=$("${CT_READELF}" -d "${libfile}"          \

                           |"${grep}" "Library soname:"             \

                           |"${sed}" -r -e 's,.+\[(.+)\] *$,\1,;'   \

                          )

            case "${libfile}" in

                */ld*)  mode=0755;;

                *)      mode=0644;;

            esac

            ${CT_PRINTF} "      installing as '%s/%s', mode='%s'\n" "${dir}" "${true_libname}" "${mode}"

            ${install} -m "${mode}" "${libfile}" "${dir}/${true_libname}"

            do_resolve_deps "${dir}/${true_libname}"

            return 0

        fi

    done

    return 1

}

# A function to resolve all NEEDED entries for the given file, relative

# to the working directory (eg. dst_dir)

# Usage: do_resolve_deps some/where/some/file

# Returns: 0, meaning all dependencies were found

# If not all dependencies could be found, exists with error code 1

# (unless forced)

do_resolve_deps() {

    local file="${1}"

    local libname

    for libname in $("${CT_READELF}" -d "${file}"                           \

                     |"${grep}" -E '\(NEEDED\)[[:space:]]+Shared library:'  \

                     |"${sed}" -r -e 's,.+\[(.+)\] *$,\1,;'                 \

                    ); do

        [ -n "${libname}" ] || continue

        ${CT_PRINTF} "Searching for '%s' needed by '%s'\n" "${libname}" "${file}"

        if ! do_add_lib "${libname}"; then

            printf "$myname: library '${libname}' not found!\n"

            [ "${CT_FORCE}" = "y" ] || exit 1

        fi

    done

}

# We'll work in the copied rootfs

cd "${CT_ROOT_DST_DIR}"

# First of, copy the forced libraries into the working copy

lib_list=

if [ -n "${CT_LIB_FILE}" ]; then

    lib_list=$("${sed}" -r -e ':loop; s/#.*//;'         \

                           -e 's/[[:space:]]+//g;'      \

                           -e 's/([^:])$/\1:/;'         \

                           -e '/$/N; s/\n//; tloop;'    \

                        "${CT_LIB_FILE}"

              )

fi

CT_LIB_LIST=$(printf "${CT_LIB_LIST}:${lib_list}\n"         \

              |"${sed}" -r -e 's/^:+//; s/:+$//; s/:+/ /g;' \

             )

if [ -n "${CT_LIB_LIST}" ]; then

    for name in ${CT_LIB_LIST}; do

        [ -z "${name}" ] && continue

        found=0

        for libname in "lib${name}.so" "${name}.so" "${name}"; do

            ${CT_PRINTF} "Searching for forced library '%s'\n" "${libname}"

            if do_add_lib "${libname}"; then

                found=1

                break

            fi

        done

        if [ ${found} -eq 0 ]; then

            printf "$myname: library '${libname}' not found!\n"

            [ "${CT_FORCE}" = "y" ] || exit 1

        fi

    done

fi

# Create a temporary place where to store... temp files.

rand="$( dd if=/dev/urandom bs=1024 count=1 2>/dev/null \

         |md5sum                                        \

         |awk '{ print $1; }'

       )"

CT_TMP_DIR="${TMPDIR:-/tmp}/populate-${rand}-${$}"

( umask 0077; mkdir "${CT_TMP_DIR}" ) || { printf "Could not create temporary directory\n"; exit 1; }

trap "rm -rf ${CT_TMP_DIR}" EXIT

# List all ELF (executables|shared objects)...

find . -type f -exec file {} \;                                             \

|"${grep}" -E ': ELF [[:digit:]]+-bit (L|M)SB (executable|shared object),'  \

|cut -d ":" -f 1                                                            \

>"${CT_TMP_DIR}/files.list"

# ... and use that list to find missing dependencies

while read file; do

    do_resolve_deps "${file}"

done <"${CT_TMP_DIR}/files.list"

rm -rf "${CT_TMP_DIR}"

trap - EXIT

# OK, we're done. Back off.

cd - >/dev/null