#! /bin/bash -efu

# heavily based upon find-suggests.ksyms by Andreas Gruenbacher <agruen@suse.de>.
# with modifications by Michael Brown <Michael_E_Brown@dell.com>
#
# -- added module versioning info to modalias() symbols
# -- removed code which inspects spec files.

IFS=$'\n'

#
# Initially, dont generate modalias() lines for kernel package. This needs
# additional discussion. Would like to eventually add them for
# completeness, so that we can determine when drivers are folded into
# mainline kernel.
#
is_kernel_package=""
case "${1:-}" in
kernel-module-*)    ;; # Fedora kernel module package names start with
		       # kernel-module.
kernel*)	   is_kernel_package=1 ;;
esac

if ! [ -z "$is_kernel_package" ]; then
    cat > /dev/null
    exit 0
fi

# Check for presence of the commands used.
# "command" is a builtin, faster to use than fork+execing "which" - see
# https://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html
command -v /sbin/modinfo >/dev/null || exit 1
command -v sed >/dev/null || exit 1
command -v sort >/dev/null || exit 1

print_modaliases() {
    declare class=$1 variants=$2 pos=$3
    if [ -n "$variants" ]; then
	echo "${class:0:pos}[$variants]${class:pos+1}"
    else
	[ -z "$class" ] || echo "$class"
    fi
}

combine_modaliases() {
    declare tag class variants="" pos="" n

    # Due to set -e, we can exit with exitcode 1 on read EOF
    # and this makes our caller think we failed. "|| return 0" prevents this:
    read class || return 0

    while read tag; do
	for ((n=0; n<${#class}; n++)); do
	    if [ "*" != "${class:n:1}" -a \
		 "${class:0:n}" = "${tag:0:n}" -a \
		 "${class:n+1}" = "${tag:n+1}" ] &&
	       ( [ -z "$pos" ] || [ $n = $pos ] ); then
		variants="${variants:-${class:n:1}}${tag:n:1}"
		pos=$n
		break
	    fi
	done
	if [ $n -eq ${#class} ]; then
	    print_modaliases "$class" "$variants" "$pos"
	    variants=
	    pos=
	    class=$tag
	fi
    done
    print_modaliases "$class" "$variants" "$pos"
}

for module in $(grep -E '/lib/modules/.+\.ko(\.gz|\.bz2|\.xz|\.zst)?$') "$@"; do
    # | head -n1 because some modules have *two* version tags. *cough*b44*cough*
    modver=$(/sbin/modinfo -F version "$module"| head -n1)
    modver=${modver//[^0-9a-zA-Z._]/_}
    # only add version tag if it has a version
    [ -z "$modver" ] || modver=" = $modver"

    /sbin/modinfo -F alias "$module" \
    | sed -nre "s,[^][0-9a-zA-Z._:*?/-],_,g; s,(.+),modalias(\\1)$modver,p"
done \
| sort -u \
| combine_modaliases