#!@@CT_bash@@

# NON-CONFIGURABLE STUFF!
export LC_ALL=C
sed="@@CT_sed@@"
grep="@@CT_grep@@"
my_name="$( basename "${0}" )"
prefix="${0%-ldd}"
gcc="${prefix}-gcc"
readelf="${prefix}-readelf"
fake_load_addr="$((0xdeadbeef))"
fake_load_addr_sys="$((0x8badf00d))"
ld_library_path="/lib:/usr/lib"

do_error() {
    printf "%s: %s\n" "${my_name}" "$*" >&2
}

do_opt_error() {
    do_error "$@"
    printf "Try \`%s --help' for more information\n >&2"
}

show_version() {
    # Fake a real ldd, just in case some dumb script would check
    cat <<_EOF_
ldd (crosstool-NG) 1.8.0
Copyright (C) 2010 "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Licensed under the GPLv2, see the file LICENSES in the top-directory of the
sources for this package.
_EOF_
}

show_help() {
    cat <<_EOF_
Usage: ${my_name} [OPTION]... --root DIR FILE...
      --help              print this help and exit
      --version           print version information and exit
      --root dir          treat dir as being the root of the target
  -s, --show-system       mark libs from the sysroot with a trailing '[*]'

_EOF_
    cat <<_EOF_ |fmt
${my_name} tries to mimick the behavior of a real native ldd, but can be
used in a cross-development environment. Here is how it differs from a
real native ldd:

The LD_LIBRARY_PATH variable is not used, as it can not reliably be
guessed except at runtime, and we can't run.

${my_name} does not scan /etc/ld.so.cache, but instead uses /etc/ld.so.conf
(it understands the include directives therein for libces that have that).
[Note: this is missing for now...]

${my_name} will search the directory specified with --root for libraries
to resolve the NEEDED tags. If --root is not set, then ${my_name} will
use the value in the environment variable \${CT_XLDD_ROOT}. If neither
is set, then this is an error.

If NEEDED libraries can't be found in the specified root directory, then
${my_name} will also look in the sysroot of the toolchain to see if it
can find them.

For NEEDED libraries that were found, the output will look like:
        libneeded.so => /path/to/libneeded.so (0xloadaddr)

and for those that were not found, the output will look like:
        libneeded.so not found

The paths are relative to the specified root directory, or to the sysroot
(eg. /lib/libneeded.so, /usr/lib/libneeded.so, and so on...).

The expected load address 'loadaddr' is a faked address to match the output
of the real ldd, but has no actual meaning (set to some constants for now,
0x8badf00d for libraries from the sysroot, 0xdeadbeff for others).
_EOF_

# Unimplemeted yet:
#  -d, --data-relocs       process data relocations
#  -r, --function-relocs   process data and function relocations
#  -u, --unused            print unused direct dependencies
#  -v, --verbose           print all information

# See also this thread:
#  http://sourceware.org/ml/crossgcc/2008-09/msg00057.html
}

# Parse command line options
root="${CT_XLDD_ROOT}"
show_system=
while true; do
    case "${1}" in
        --help)
            show_help
            exit 0
            ;;
        --version)
            show_version
            exit 0
            ;;
        --root)
            root="$2"
            shift
            ;;
        --root=*)
            root="${1#--root=}"
            ;;
        --show-system|-s)
            show_system=1
            ;;
        -*)
            do_opt_error "unrecognized option \`${1}'"
            exit 1
            ;;
        *)
            break
            ;;
    esac
    shift
done

# Sanity checks
if [ -z "${root}" ]; then
    do_opt_error "no root given"
    exit 1
fi
if [ ! -d "${root}" ]; then
    do_error "\`${root}': no such file or directory"
    exit 1
fi

sysroot="$( "${gcc}" -print-sysroot )"

do_report_needed_found() {
    local needed="${1}"
    local path="${2}"
    local system="${3}"
    local loadaddr
    local sys

    if [ -z "${system}" ]; then
        loadaddr="${fake_load_addr}"
    else
        loadaddr="${fake_load_addr_sys}"
        if [ -n "${show_system}" ]; then
            sys=" [*]"
        fi
    fi

    # 8 to fake a 32-bit load address
    printf "%8s%s => %s (0x%0*x)%s\n"   \
           ""                           \
           "${needed}"                  \
           "${path}"                    \
           8                            \
           "${loadaddr}"                \
           "${sys}"
}

# Search a needed file, scanning ${lib_dir} in the root directory
do_find_needed() {
    local needed="${1}"
    local found
    local found_sysroot
    local d

    for d in "${needed_search_path[@]}"; do
        if [ -f "${root}${d}/${needed}" ]; then
            found="${d}/${needed}"
        fi
    done
    if [ -z "${found}" ]; then
    for d in "${needed_search_path[@]}"; do
        if [ -f "${sysroot}${d}/${needed}" ]; then
            found_sysroot="${d}/${needed}"
        fi
    done
    fi

    if [ -n "${found}" ]; then
        do_report_needed_found "${needed}" "${found}"
        do_process_file "${root}${found}"
    elif [ -n "${found_sysroot}" ]; then
        do_report_needed_found "${needed}" "${found_sysroot}" "sys"
        do_process_file "${sysroot}${found_sysroot}"
    else
        printf "%8c%s not found\n" "" "${needed}"
    fi
}

# Scan a file for all NEEDED tags
do_process_file() {
    local file="${1}"

    "${readelf}" -d "${file}"                                           \
    |"${grep}" -E '\(NEEDED\)'                                          \
    |"${sed}" -r -e 's/^.*Shared library:[[:space:]]+\[(.*)\]$/\1/;'    \
    |while read needed; do
        do_find_needed "${needed}"
     done
}

# Build up the full list of search directories
declare -a needed_search_path
ld_library_path="${ld_library_path}:"
while [ -n "${ld_library_path}" ]; do
    d="${ld_library_path%%:*}"
    [ -n "${d}" ] && needed_search_path+=( "${d}" )
    ld_library_path="${ld_library_path#*:}"
done

do_process_file "${1}"
