eclass/versionator.eclass - mirrors/cros/chromiumos/overlays/portage-stable - Git at Google

 # Copyright 1999-2018 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2

 # @ECLASS: versionator.eclass
 # @MAINTAINER:
 # Jonathan Callen <jcallen@gentoo.org>
 # base-system@gentoo.org
 # @BLURB: functions which simplify manipulation of ${PV} and similar version strings
 # @DESCRIPTION:
 # This eclass provides functions which simplify manipulating $PV and similar
 # variables. Most functions default to working with $PV, although other
 # values can be used.
 # @EXAMPLE:
 # Simple Example 1: $PV is 1.2.3b, we want 1_2.3b:
 #     MY_PV=$(replace_version_separator 1 '_' )
 #
 # Simple Example 2: $PV is 1.4.5, we want 1:
 #     MY_MAJORV=$(get_major_version )
 #
 # Rather than being a number, the index parameter can be a separator character
 # such as '-', '.' or '_'. In this case, the first separator of this kind is
 # selected.
 #
 # There's also:
 #     version_is_at_least             want      have
 #  which may be buggy, so use with caution.

 if [[ -z ${_VERSIONATOR_ECLASS} ]]; then
 _VERSIONATOR_ECLASS=1

 case ${EAPI:-0} in
 	0|1|2|3|4|5|6)
 		;;
 	*)
 		die "${ECLASS}: banned in EAPI=${EAPI}; use ver_* instead";;
 esac

 inherit estack

 # @FUNCTION: get_all_version_components
 # @USAGE: [version]
 # @DESCRIPTION:
 # Split up a version string into its component parts. If no parameter is
 # supplied, defaults to $PV.
 #     0.8.3       ->  0 . 8 . 3
 #     7c          ->  7 c
 #     3.0_p2      ->  3 . 0 _ p2
 #     20040905    ->  20040905
 #     3.0c-r1     ->  3 . 0 c - r1
 get_all_version_components() {
 	eshopts_push -s extglob
 	local ver_str=${1:-${PV}} result
 	result=()

 	# sneaky cache trick cache to avoid having to parse the same thing several
 	# times.
 	if [[ ${VERSIONATOR_CACHE_VER_STR} == ${ver_str} ]] ; then
 		echo ${VERSIONATOR_CACHE_RESULT}
 		eshopts_pop
 		return
 	fi
 	export VERSIONATOR_CACHE_VER_STR=${ver_str}

 	while [[ -n $ver_str ]] ; do
 		case "${ver_str::1}" in
 			# number: parse whilst we have a number
 			[[:digit:]])
 				result+=("${ver_str%%[^[:digit:]]*}")
 				ver_str=${ver_str##+([[:digit:]])}
 				;;

 			# separator: single character
 			[-_.])
 				result+=("${ver_str::1}")
 				ver_str=${ver_str:1}
 				;;

 			# letter: grab the letters plus any following numbers
 			[[:alpha:]])
 				local not_match=${ver_str##+([[:alpha:]])*([[:digit:]])}
 				# Can't say "${ver_str::-${#not_match}}" in Bash 3.2
 				result+=("${ver_str::${#ver_str} - ${#not_match}}")
 				ver_str=${not_match}
 				;;

 			# huh?
 			*)
 				result+=("${ver_str::1}")
 				ver_str=${ver_str:1}
 				;;
 		esac
 	done

 	export VERSIONATOR_CACHE_RESULT=${result[*]}
 	echo ${result[@]}
 	eshopts_pop
 }

 # @FUNCTION: get_version_components
 # @USAGE: [version]
 # @DESCRIPTION:
 # Get the important version components, excluding '.', '-' and '_'. Defaults to
 # $PV if no parameter is supplied.
 #     0.8.3       ->  0 8 3
 #     7c          ->  7 c
 #     3.0_p2      ->  3 0 p2
 #     20040905    ->  20040905
 #     3.0c-r1     ->  3 0 c r1
 get_version_components() {
 	local c=$(get_all_version_components "${1:-${PV}}")
 	echo ${c//[-._]/ }
 }

 # @FUNCTION: get_major_version
 # @USAGE: [version]
 # @DESCRIPTION:
 # Get the major version of a value. Defaults to $PV if no parameter is supplied.
 #     0.8.3       ->  0
 #     7c          ->  7
 #     3.0_p2      ->  3
 #     20040905    ->  20040905
 #     3.0c-r1     ->  3
 get_major_version() {
 	local c=($(get_all_version_components "${1:-${PV}}"))
 	echo ${c[0]}
 }

 # @FUNCTION: get_version_component_range
 # @USAGE: <range> [version]
 # @DESCRIPTION:
 # Get a particular component or range of components from the version. If no
 # version parameter is supplied, defaults to $PV.
 #    1      1.2.3       -> 1
 #    1-2    1.2.3       -> 1.2
 #    2-     1.2.3       -> 2.3
 get_version_component_range() {
 	eshopts_push -s extglob
 	local c v="${2:-${PV}}" range="${1}" range_start range_end
 	local -i i=-1 j=0
 	c=($(get_all_version_components "${v}"))
 	range_start=${range%-*}; range_start=${range_start:-1}
 	range_end=${range#*-}  ; range_end=${range_end:-${#c[@]}}

 	while ((j < range_start)); do
 		i+=1
 		((i > ${#c[@]})) && eshopts_pop && return
 		[[ -n "${c[i]//[-._]}" ]] && j+=1
 	done

 	while ((j <= range_end)); do
 		echo -n ${c[i]}
 		((i > ${#c[@]})) && eshopts_pop && return
 		[[ -n "${c[i]//[-._]}" ]] && j+=1
 		i+=1
 	done
 	eshopts_pop
 }

 # @FUNCTION: get_after_major_version
 # @USAGE: [version]
 # @DESCRIPTION:
 # Get everything after the major version and its separator (if present) of a
 # value. Defaults to $PV if no parameter is supplied.
 #     0.8.3       ->  8.3
 #     7c          ->  c
 #     3.0_p2      ->  0_p2
 #     20040905    ->  (empty string)
 #     3.0c-r1     ->  0c-r1
 get_after_major_version() {
 	echo $(get_version_component_range 2- "${1:-${PV}}")
 }

 # @FUNCTION: replace_version_separator
 # @USAGE: <search> <replacement> [subject]
 # @DESCRIPTION:
 # Replace the $1th separator with $2 in $3 (defaults to $PV if $3 is not
 # supplied). If there are fewer than $1 separators, don't change anything.
 #     1 '_' 1.2.3       -> 1_2.3
 #     2 '_' 1.2.3       -> 1.2_3
 #     1 '_' 1b-2.3      -> 1b_2.3
 # Rather than being a number, $1 can be a separator character such as '-', '.'
 # or '_'. In this case, the first separator of this kind is selected.
 replace_version_separator() {
 	eshopts_push -s extglob
 	local w c v="${3:-${PV}}"
 	declare -i i found=0
 	w=${1:-1}
 	c=($(get_all_version_components ${v}))
 	if [[ ${w} != *[[:digit:]]* ]] ; then
 		# it's a character, not an index
 		for ((i = 0; i < ${#c[@]}; i++)); do
 			if [[ ${c[i]} == ${w} ]]; then
 				c[i]=${2}
 				break
 			fi
 		done
 	else
 		for ((i = 0; i < ${#c[@]}; i++)); do
 			if [[ -n "${c[i]//[^-._]}" ]]; then
 				found+=1
 				if ((found == w)); then
 					c[i]=${2}
 					break
 				fi
 			fi
 		done
 	fi
 	c=${c[*]}
 	echo ${c// }
 	eshopts_pop
 }

 # @FUNCTION: replace_all_version_separators
 # @USAGE: <replacement> [subject]
 # @DESCRIPTION:
 # Replace all version separators in $2 (defaults to $PV) with $1.
 #     '_' 1b.2.3        -> 1b_2_3
 replace_all_version_separators() {
 	local c=($(get_all_version_components "${2:-${PV}}"))
 	c=${c[@]//[-._]/$1}
 	echo ${c// }
 }

 # @FUNCTION: delete_version_separator
 # @USAGE: <search> [subject]
 # @DESCRIPTION:
 # Delete the $1th separator in $2 (defaults to $PV if $2 is not supplied). If
 # there are fewer than $1 separators, don't change anything.
 #     1 1.2.3       -> 12.3
 #     2 1.2.3       -> 1.23
 #     1 1b-2.3      -> 1b2.3
 # Rather than being a number, $1 can be a separator character such as '-', '.'
 # or '_'. In this case, the first separator of this kind is deleted.
 delete_version_separator() {
 	replace_version_separator "${1}" "" "${2}"
 }

 # @FUNCTION: delete_all_version_separators
 # @USAGE: [subject]
 # @DESCRIPTION:
 # Delete all version separators in $1 (defaults to $PV).
 #     1b.2.3        -> 1b23
 delete_all_version_separators() {
 	replace_all_version_separators "" "${1}"
 }

 # @FUNCTION: get_version_component_count
 # @USAGE: [version]
 # @DESCRIPTION:
 # How many version components are there in $1 (defaults to $PV)?
 #     1.0.1       ->  3
 #     3.0c-r1     ->  4
 get_version_component_count() {
 	local a=($(get_version_components "${1:-${PV}}"))
 	echo ${#a[@]}
 }

 # @FUNCTION: get_last_version_component_index
 # @USAGE: [version]
 # @DESCRIPTION:
 # What is the index of the last version component in $1 (defaults to $PV)?
 # Equivalent to get_version_component_count - 1.
 #     1.0.1       ->  2
 #     3.0c-r1     ->  3
 get_last_version_component_index() {
 	echo $(($(get_version_component_count "${1:-${PV}}" ) - 1))
 }

 # @FUNCTION: version_is_at_least
 # @USAGE: <want> [have]
 # @DESCRIPTION:
 # Is $2 (defaults to $PVR) at least version $1? Intended for use in eclasses
 # only. May not be reliable, be sure to do very careful testing before actually
 # using this.
 version_is_at_least() {
 	local want_s="$1" have_s="${2:-${PVR}}" r
 	version_compare "${want_s}" "${have_s}"
 	r=$?
 	case $r in
 		1|2)
 			return 0
 			;;
 		3)
 			return 1
 			;;
 		*)
 			die "versionator compare bug [atleast, ${want_s}, ${have_s}, ${r}]"
 			;;
 	esac
 }

 # @FUNCTION: version_compare
 # @USAGE: <A> <B>
 # @DESCRIPTION:
 # Takes two parameters (A, B) which are versions. If A is an earlier version
 # than B, returns 1. If A is identical to B, return 2. If A is later than B,
 # return 3. You probably want version_is_at_least rather than this function.
 # May not be very reliable. Test carefully before using this.
 version_compare() {
 	eshopts_push -s extglob
 	local ver_a=${1} ver_b=${2} parts_a parts_b
 	local cur_tok_a cur_tok_b num_part_a num_part_b
 	local -i cur_idx_a=0 cur_idx_b=0 prev_idx_a prev_idx_b
 	parts_a=( $(get_all_version_components "${ver_a}" ) )
 	parts_b=( $(get_all_version_components "${ver_b}" ) )

 	### compare number parts.
 	local -i inf_loop=0
 	while true; do
 		inf_loop+=1
 		((inf_loop > 20)) && \
 			die "versionator compare bug [numbers, ${ver_a}, ${ver_b}]"

 		# Store the current index to test later
 		prev_idx_a=cur_idx_a
 		prev_idx_b=cur_idx_b

 		# grab the current number components
 		cur_tok_a=${parts_a[cur_idx_a]}
 		cur_tok_b=${parts_b[cur_idx_b]}

 		# number?
 		if [[ -n ${cur_tok_a} ]] && [[ -z ${cur_tok_a//[[:digit:]]} ]] ; then
 			cur_idx_a+=1
 			[[ ${parts_a[cur_idx_a]} == . ]] \
 				&& cur_idx_a+=1
 		else
 			cur_tok_a=
 		fi

 		if [[ -n ${cur_tok_b} ]] && [[ -z ${cur_tok_b//[[:digit:]]} ]] ; then
 			cur_idx_b+=1
 			[[ ${parts_b[cur_idx_b]} == . ]] \
 				&& cur_idx_b+=1
 		else
 			cur_tok_b=
 		fi

 		# done with number components?
 		[[ -z ${cur_tok_a} && -z ${cur_tok_b} ]] && break

 		# if a component is blank, then it is the lesser value
 		[[ -z ${cur_tok_a} ]] && eshopts_pop && return 1
 		[[ -z ${cur_tok_b} ]] && eshopts_pop && return 3

 		# According to PMS, if we are *not* in the first number part, and either
 		# token begins with "0", then we use a different algorithm (that
 		# effectively does floating point comparison)
 		if (( prev_idx_a != 0 && prev_idx_b != 0 )) \
 			&& [[ ${cur_tok_a} == 0* || ${cur_tok_b} == 0* ]] ; then

 			# strip trailing zeros
 			cur_tok_a=${cur_tok_a%%+(0)}
 			cur_tok_b=${cur_tok_b%%+(0)}

 			# do a *string* comparison of the resulting values: 2 > 11
 			[[ ${cur_tok_a} < ${cur_tok_b} ]] && eshopts_pop && return 1
 			[[ ${cur_tok_a} > ${cur_tok_b} ]] && eshopts_pop && return 3
 		else
 			# to avoid going into octal mode, strip any leading zeros. otherwise
 			# bash will throw a hissy fit on versions like 6.3.068.
 			cur_tok_a=${cur_tok_a##+(0)}
 			cur_tok_b=${cur_tok_b##+(0)}

 			# now if a component is blank, it was originally 0 -- make it so
 			: ${cur_tok_a:=0}
 			: ${cur_tok_b:=0}

 			# compare
 			((cur_tok_a < cur_tok_b)) && eshopts_pop && return 1
 			((cur_tok_a > cur_tok_b)) && eshopts_pop && return 3
 		fi
 	done

 	### number parts equal. compare letter parts.
 	local letter_a=
 	letter_a=${parts_a[cur_idx_a]}
 	if [[ ${#letter_a} -eq 1 && -z ${letter_a/[a-z]} ]] ; then
 		cur_idx_a+=1
 	else
 		letter_a=@
 	fi

 	local letter_b=
 	letter_b=${parts_b[cur_idx_b]}
 	if [[ ${#letter_b} -eq 1 && -z ${letter_b/[a-z]} ]] ; then
 		cur_idx_b+=1
 	else
 		letter_b=@
 	fi

 	# compare
 	[[ ${letter_a} < ${letter_b} ]] && eshopts_pop && return 1
 	[[ ${letter_a} > ${letter_b} ]] && eshopts_pop && return 3

 	### letter parts equal. compare suffixes in order.
 	inf_loop=0
 	while true ; do
 		inf_loop+=1
 		((inf_loop > 20)) && \
 			die "versionator compare bug [numbers, ${ver_a}, ${ver_b}]"
 		[[ ${parts_a[cur_idx_a]} == _ ]] && ((cur_idx_a++))
 		[[ ${parts_b[cur_idx_b]} == _ ]] && ((cur_idx_b++))

 		cur_tok_a=${parts_a[cur_idx_a]}
 		cur_tok_b=${parts_b[cur_idx_b]}
 		num_part_a=0
 		num_part_b=0

 		if has ${cur_tok_a%%+([0-9])} "alpha" "beta" "pre" "rc" "p"; then
 			cur_idx_a+=1
 			num_part_a=${cur_tok_a##+([a-z])}
 			# I don't like octal
 			num_part_a=${num_part_a##+(0)}
 			: ${num_part_a:=0}
 			cur_tok_a=${cur_tok_a%%+([0-9])}
 		else
 			cur_tok_a=
 		fi

 		if has ${cur_tok_b%%+([0-9])} alpha beta pre rc p; then
 			cur_idx_b+=1
 			num_part_b=${cur_tok_b##+([a-z])}
 			# I still don't like octal
 			num_part_b=${num_part_b##+(0)}
 			: ${num_part_b:=0}
 			cur_tok_b=${cur_tok_b%%+([0-9])}
 		else
 			cur_tok_b=
 		fi

 		if [[ ${cur_tok_a} != ${cur_tok_b} ]]; then
 			local suffix
 			for suffix in alpha beta pre rc "" p; do
 				[[ ${cur_tok_a} == ${suffix} ]] && eshopts_pop && return 1
 				[[ ${cur_tok_b} == ${suffix} ]] && eshopts_pop && return 3
 			done
 		elif [[ -z ${cur_tok_a} && -z ${cur_tok_b} ]]; then
 			break
 		else
 			((num_part_a < num_part_b)) && eshopts_pop && return 1
 			((num_part_a > num_part_b)) && eshopts_pop && return 3
 		fi
 	done

 	# At this point, the only thing that should be left is the -r# part
 	[[ ${parts_a[cur_idx_a]} == - ]] && ((cur_idx_a++))
 	[[ ${parts_b[cur_idx_b]} == - ]] && ((cur_idx_b++))

 	# Sanity check
 	if [[ ${parts_a[cur_idx_a]/r+([0-9])} || ${parts_b[cur_idx_b]/r+([0-9])} ]]; then
 		die "versionator compare bug [revisions, ${ver_a}, ${ver_b}]"
 	fi

 	num_part_a=${parts_a[cur_idx_a]#r}
 	num_part_a=${num_part_a##+(0)}
 	: ${num_part_a:=0}
 	num_part_b=${parts_b[cur_idx_b]#r}
 	num_part_b=${num_part_b##+(0)}
 	: ${num_part_b:=0}

 	((num_part_a < num_part_b)) && eshopts_pop && return 1
 	((num_part_a > num_part_b)) && eshopts_pop && return 3

 	### no differences.
 	eshopts_pop
 	return 2
 }

 # @FUNCTION: version_sort
 # @USAGE: <version> [more versions...]
 # @DESCRIPTION:
 # Returns its parameters sorted, highest version last. We're using a quadratic
 # algorithm for simplicity, so don't call it with more than a few dozen items.
 # Uses version_compare, so be careful.
 version_sort() {
 	eshopts_push -s extglob
 	local items=
 	local -i left=0
 	items=("$@")
 	while ((left < ${#items[@]})); do
 		local -i lowest_idx=left
 		local -i idx=lowest_idx+1
 		while ((idx < ${#items[@]})); do
 			version_compare "${items[lowest_idx]}" "${items[idx]}"
 			[[ $? -eq 3 ]] && lowest_idx=idx
 			idx+=1
 		done
 		local tmp=${items[lowest_idx]}
 		items[lowest_idx]=${items[left]}
 		items[left]=${tmp}
 		left+=1
 	done
 	echo ${items[@]}
 	eshopts_pop
 }

 # @FUNCTION: version_format_string
 # @USAGE: <format> [version]
 # @DESCRIPTION:
 # Reformat complicated version strings.  The first argument is the string
 # to reformat with while the rest of the args are passed on to the
 # get_version_components function.  You should make sure to single quote
 # the first argument since it'll have variables that get delayed expansions.
 # @EXAMPLE:
 # P="cow-hat-1.2.3_p4"
 # MY_P=$(version_format_string '${PN}_source_$1_$2-$3_$4')
 # Now MY_P will be: cow-hat_source_1_2-3_p4
 version_format_string() {
 	local fstr=$1
 	shift
 	set -- $(get_version_components "$@")
 	eval echo "${fstr}"
 }

 fi
	# Copyright 1999-2018 Gentoo Foundation
	# Distributed under the terms of the GNU General Public License v2

	# @ECLASS: versionator.eclass
	# @MAINTAINER:
	# Jonathan Callen <jcallen@gentoo.org>
	# base-system@gentoo.org
	# @BLURB: functions which simplify manipulation of ${PV} and similar version strings
	# @DESCRIPTION:
	# This eclass provides functions which simplify manipulating $PV and similar
	# variables. Most functions default to working with $PV, although other
	# values can be used.
	# @EXAMPLE:
	# Simple Example 1: $PV is 1.2.3b, we want 1_2.3b:
	# MY_PV=$(replace_version_separator 1 '_' )
	#
	# Simple Example 2: $PV is 1.4.5, we want 1:
	# MY_MAJORV=$(get_major_version )
	#
	# Rather than being a number, the index parameter can be a separator character
	# such as '-', '.' or '_'. In this case, the first separator of this kind is
	# selected.
	#
	# There's also:
	# version_is_at_least want have
	# which may be buggy, so use with caution.

	if [[ -z ${_VERSIONATOR_ECLASS} ]]; then
	_VERSIONATOR_ECLASS=1

	case ${EAPI:-0} in
	0\|1\|2\|3\|4\|5\|6)
	;;
	*)
	die "${ECLASS}: banned in EAPI=${EAPI}; use ver_* instead";;
	esac

	inherit estack

	# @FUNCTION: get_all_version_components
	# @USAGE: [version]
	# @DESCRIPTION:
	# Split up a version string into its component parts. If no parameter is
	# supplied, defaults to $PV.
	# 0.8.3 -> 0 . 8 . 3
	# 7c -> 7 c
	# 3.0_p2 -> 3 . 0 _ p2
	# 20040905 -> 20040905
	# 3.0c-r1 -> 3 . 0 c - r1
	get_all_version_components() {
	eshopts_push -s extglob
	local ver_str=${1:-${PV}} result
	result=()

	# sneaky cache trick cache to avoid having to parse the same thing several
	# times.
	if [[ ${VERSIONATOR_CACHE_VER_STR} == ${ver_str} ]] ; then
	echo ${VERSIONATOR_CACHE_RESULT}
	eshopts_pop
	return
	fi
	export VERSIONATOR_CACHE_VER_STR=${ver_str}

	while [[ -n $ver_str ]] ; do
	case "${ver_str::1}" in
	# number: parse whilst we have a number
	[[:digit:]])
	result+=("${ver_str%%[^[:digit:]]*}")
	ver_str=${ver_str##+([[:digit:]])}
	;;

	# separator: single character
	[-_.])
	result+=("${ver_str::1}")
	ver_str=${ver_str:1}
	;;

	# letter: grab the letters plus any following numbers
	[[:alpha:]])
	local not_match=${ver_str##+([[:alpha:]])*([[:digit:]])}
	# Can't say "${ver_str::-${#not_match}}" in Bash 3.2
	result+=("${ver_str::${#ver_str} - ${#not_match}}")
	ver_str=${not_match}
	;;

	# huh?
	*)
	result+=("${ver_str::1}")
	ver_str=${ver_str:1}
	;;
	esac
	done

	export VERSIONATOR_CACHE_RESULT=${result[*]}
	echo ${result[@]}
	eshopts_pop
	}

	# @FUNCTION: get_version_components
	# @USAGE: [version]
	# @DESCRIPTION:
	# Get the important version components, excluding '.', '-' and '_'. Defaults to
	# $PV if no parameter is supplied.
	# 0.8.3 -> 0 8 3
	# 7c -> 7 c
	# 3.0_p2 -> 3 0 p2
	# 20040905 -> 20040905
	# 3.0c-r1 -> 3 0 c r1
	get_version_components() {
	local c=$(get_all_version_components "${1:-${PV}}")
	echo ${c//[-._]/ }
	}

	# @FUNCTION: get_major_version
	# @USAGE: [version]
	# @DESCRIPTION:
	# Get the major version of a value. Defaults to $PV if no parameter is supplied.
	# 0.8.3 -> 0
	# 7c -> 7
	# 3.0_p2 -> 3
	# 20040905 -> 20040905
	# 3.0c-r1 -> 3
	get_major_version() {
	local c=($(get_all_version_components "${1:-${PV}}"))
	echo ${c[0]}
	}

	# @FUNCTION: get_version_component_range
	# @USAGE: <range> [version]
	# @DESCRIPTION:
	# Get a particular component or range of components from the version. If no
	# version parameter is supplied, defaults to $PV.
	# 1 1.2.3 -> 1
	# 1-2 1.2.3 -> 1.2
	# 2- 1.2.3 -> 2.3
	get_version_component_range() {
	eshopts_push -s extglob
	local c v="${2:-${PV}}" range="${1}" range_start range_end
	local -i i=-1 j=0
	c=($(get_all_version_components "${v}"))
	range_start=${range%-*}; range_start=${range_start:-1}
	range_end=${range#*-} ; range_end=${range_end:-${#c[@]}}

	while ((j < range_start)); do
	i+=1
	((i > ${#c[@]})) && eshopts_pop && return
	[[ -n "${c[i]//[-._]}" ]] && j+=1
	done

	while ((j <= range_end)); do
	echo -n ${c[i]}
	((i > ${#c[@]})) && eshopts_pop && return
	[[ -n "${c[i]//[-._]}" ]] && j+=1
	i+=1
	done
	eshopts_pop
	}

	# @FUNCTION: get_after_major_version
	# @USAGE: [version]
	# @DESCRIPTION:
	# Get everything after the major version and its separator (if present) of a
	# value. Defaults to $PV if no parameter is supplied.
	# 0.8.3 -> 8.3
	# 7c -> c
	# 3.0_p2 -> 0_p2
	# 20040905 -> (empty string)
	# 3.0c-r1 -> 0c-r1
	get_after_major_version() {
	echo $(get_version_component_range 2- "${1:-${PV}}")
	}

	# @FUNCTION: replace_version_separator
	# @USAGE: <search> <replacement> [subject]
	# @DESCRIPTION:
	# Replace the $1th separator with $2 in $3 (defaults to $PV if $3 is not
	# supplied). If there are fewer than $1 separators, don't change anything.
	# 1 '_' 1.2.3 -> 1_2.3
	# 2 '_' 1.2.3 -> 1.2_3
	# 1 '_' 1b-2.3 -> 1b_2.3
	# Rather than being a number, $1 can be a separator character such as '-', '.'
	# or '_'. In this case, the first separator of this kind is selected.
	replace_version_separator() {
	eshopts_push -s extglob
	local w c v="${3:-${PV}}"
	declare -i i found=0
	w=${1:-1}
	c=($(get_all_version_components ${v}))
	if [[ ${w} != [[:digit:]] ]] ; then
	# it's a character, not an index
	for ((i = 0; i < ${#c[@]}; i++)); do
	if [[ ${c[i]} == ${w} ]]; then
	c[i]=${2}
	break
	fi
	done
	else
	for ((i = 0; i < ${#c[@]}; i++)); do
	if [[ -n "${c[i]//[^-._]}" ]]; then
	found+=1
	if ((found == w)); then
	c[i]=${2}
	break
	fi
	fi
	done
	fi
	c=${c[*]}
	echo ${c// }
	eshopts_pop
	}

	# @FUNCTION: replace_all_version_separators
	# @USAGE: <replacement> [subject]
	# @DESCRIPTION:
	# Replace all version separators in $2 (defaults to $PV) with $1.
	# '_' 1b.2.3 -> 1b_2_3
	replace_all_version_separators() {
	local c=($(get_all_version_components "${2:-${PV}}"))
	c=${c[@]//[-._]/$1}
	echo ${c// }
	}

	# @FUNCTION: delete_version_separator
	# @USAGE: <search> [subject]
	# @DESCRIPTION:
	# Delete the $1th separator in $2 (defaults to $PV if $2 is not supplied). If
	# there are fewer than $1 separators, don't change anything.
	# 1 1.2.3 -> 12.3
	# 2 1.2.3 -> 1.23
	# 1 1b-2.3 -> 1b2.3
	# Rather than being a number, $1 can be a separator character such as '-', '.'
	# or '_'. In this case, the first separator of this kind is deleted.
	delete_version_separator() {
	replace_version_separator "${1}" "" "${2}"
	}

	# @FUNCTION: delete_all_version_separators
	# @USAGE: [subject]
	# @DESCRIPTION:
	# Delete all version separators in $1 (defaults to $PV).
	# 1b.2.3 -> 1b23
	delete_all_version_separators() {
	replace_all_version_separators "" "${1}"
	}

	# @FUNCTION: get_version_component_count
	# @USAGE: [version]
	# @DESCRIPTION:
	# How many version components are there in $1 (defaults to $PV)?
	# 1.0.1 -> 3
	# 3.0c-r1 -> 4
	get_version_component_count() {
	local a=($(get_version_components "${1:-${PV}}"))
	echo ${#a[@]}
	}

	# @FUNCTION: get_last_version_component_index
	# @USAGE: [version]
	# @DESCRIPTION:
	# What is the index of the last version component in $1 (defaults to $PV)?
	# Equivalent to get_version_component_count - 1.
	# 1.0.1 -> 2
	# 3.0c-r1 -> 3
	get_last_version_component_index() {
	echo $(($(get_version_component_count "${1:-${PV}}" ) - 1))
	}

	# @FUNCTION: version_is_at_least
	# @USAGE: <want> [have]
	# @DESCRIPTION:
	# Is $2 (defaults to $PVR) at least version $1? Intended for use in eclasses
	# only. May not be reliable, be sure to do very careful testing before actually
	# using this.
	version_is_at_least() {
	local want_s="$1" have_s="${2:-${PVR}}" r
	version_compare "${want_s}" "${have_s}"
	r=$?
	case $r in
	1\|2)
	return 0
	;;
	3)
	return 1
	;;
	*)
	die "versionator compare bug [atleast, ${want_s}, ${have_s}, ${r}]"
	;;
	esac
	}

	# @FUNCTION: version_compare
	# @USAGE: <A> <B>
	# @DESCRIPTION:
	# Takes two parameters (A, B) which are versions. If A is an earlier version
	# than B, returns 1. If A is identical to B, return 2. If A is later than B,
	# return 3. You probably want version_is_at_least rather than this function.
	# May not be very reliable. Test carefully before using this.
	version_compare() {
	eshopts_push -s extglob
	local ver_a=${1} ver_b=${2} parts_a parts_b
	local cur_tok_a cur_tok_b num_part_a num_part_b
	local -i cur_idx_a=0 cur_idx_b=0 prev_idx_a prev_idx_b
	parts_a=( $(get_all_version_components "${ver_a}" ) )
	parts_b=( $(get_all_version_components "${ver_b}" ) )

	### compare number parts.
	local -i inf_loop=0
	while true; do
	inf_loop+=1
	((inf_loop > 20)) && \
	die "versionator compare bug [numbers, ${ver_a}, ${ver_b}]"

	# Store the current index to test later
	prev_idx_a=cur_idx_a
	prev_idx_b=cur_idx_b

	# grab the current number components
	cur_tok_a=${parts_a[cur_idx_a]}
	cur_tok_b=${parts_b[cur_idx_b]}

	# number?
	if [[ -n ${cur_tok_a} ]] && [[ -z ${cur_tok_a//[[:digit:]]} ]] ; then
	cur_idx_a+=1
	[[ ${parts_a[cur_idx_a]} == . ]] \
	&& cur_idx_a+=1
	else
	cur_tok_a=
	fi

	if [[ -n ${cur_tok_b} ]] && [[ -z ${cur_tok_b//[[:digit:]]} ]] ; then
	cur_idx_b+=1
	[[ ${parts_b[cur_idx_b]} == . ]] \
	&& cur_idx_b+=1
	else
	cur_tok_b=
	fi

	# done with number components?
	[[ -z ${cur_tok_a} && -z ${cur_tok_b} ]] && break

	# if a component is blank, then it is the lesser value
	[[ -z ${cur_tok_a} ]] && eshopts_pop && return 1
	[[ -z ${cur_tok_b} ]] && eshopts_pop && return 3

	# According to PMS, if we are not in the first number part, and either
	# token begins with "0", then we use a different algorithm (that
	# effectively does floating point comparison)
	if (( prev_idx_a != 0 && prev_idx_b != 0 )) \
	&& [[ ${cur_tok_a} == 0* \|\| ${cur_tok_b} == 0* ]] ; then

	# strip trailing zeros
	cur_tok_a=${cur_tok_a%%+(0)}
	cur_tok_b=${cur_tok_b%%+(0)}

	# do a string comparison of the resulting values: 2 > 11
	[[ ${cur_tok_a} < ${cur_tok_b} ]] && eshopts_pop && return 1
	[[ ${cur_tok_a} > ${cur_tok_b} ]] && eshopts_pop && return 3
	else
	# to avoid going into octal mode, strip any leading zeros. otherwise
	# bash will throw a hissy fit on versions like 6.3.068.
	cur_tok_a=${cur_tok_a##+(0)}
	cur_tok_b=${cur_tok_b##+(0)}

	# now if a component is blank, it was originally 0 -- make it so
	: ${cur_tok_a:=0}
	: ${cur_tok_b:=0}

	# compare
	((cur_tok_a < cur_tok_b)) && eshopts_pop && return 1
	((cur_tok_a > cur_tok_b)) && eshopts_pop && return 3
	fi
	done

	### number parts equal. compare letter parts.
	local letter_a=
	letter_a=${parts_a[cur_idx_a]}
	if [[ ${#letter_a} -eq 1 && -z ${letter_a/[a-z]} ]] ; then
	cur_idx_a+=1
	else
	letter_a=@
	fi

	local letter_b=
	letter_b=${parts_b[cur_idx_b]}
	if [[ ${#letter_b} -eq 1 && -z ${letter_b/[a-z]} ]] ; then
	cur_idx_b+=1
	else
	letter_b=@
	fi

	# compare
	[[ ${letter_a} < ${letter_b} ]] && eshopts_pop && return 1
	[[ ${letter_a} > ${letter_b} ]] && eshopts_pop && return 3

	### letter parts equal. compare suffixes in order.
	inf_loop=0
	while true ; do
	inf_loop+=1
	((inf_loop > 20)) && \
	die "versionator compare bug [numbers, ${ver_a}, ${ver_b}]"
	[[ ${parts_a[cur_idx_a]} == _ ]] && ((cur_idx_a++))
	[[ ${parts_b[cur_idx_b]} == _ ]] && ((cur_idx_b++))

	cur_tok_a=${parts_a[cur_idx_a]}
	cur_tok_b=${parts_b[cur_idx_b]}
	num_part_a=0
	num_part_b=0

	if has ${cur_tok_a%%+([0-9])} "alpha" "beta" "pre" "rc" "p"; then
	cur_idx_a+=1
	num_part_a=${cur_tok_a##+([a-z])}
	# I don't like octal
	num_part_a=${num_part_a##+(0)}
	: ${num_part_a:=0}
	cur_tok_a=${cur_tok_a%%+([0-9])}
	else
	cur_tok_a=
	fi

	if has ${cur_tok_b%%+([0-9])} alpha beta pre rc p; then
	cur_idx_b+=1
	num_part_b=${cur_tok_b##+([a-z])}
	# I still don't like octal
	num_part_b=${num_part_b##+(0)}
	: ${num_part_b:=0}
	cur_tok_b=${cur_tok_b%%+([0-9])}
	else
	cur_tok_b=
	fi

	if [[ ${cur_tok_a} != ${cur_tok_b} ]]; then
	local suffix
	for suffix in alpha beta pre rc "" p; do
	[[ ${cur_tok_a} == ${suffix} ]] && eshopts_pop && return 1
	[[ ${cur_tok_b} == ${suffix} ]] && eshopts_pop && return 3
	done
	elif [[ -z ${cur_tok_a} && -z ${cur_tok_b} ]]; then
	break
	else
	((num_part_a < num_part_b)) && eshopts_pop && return 1
	((num_part_a > num_part_b)) && eshopts_pop && return 3
	fi
	done

	# At this point, the only thing that should be left is the -r# part
	[[ ${parts_a[cur_idx_a]} == - ]] && ((cur_idx_a++))
	[[ ${parts_b[cur_idx_b]} == - ]] && ((cur_idx_b++))

	# Sanity check
	if [[ ${parts_a[cur_idx_a]/r+([0-9])} \|\| ${parts_b[cur_idx_b]/r+([0-9])} ]]; then
	die "versionator compare bug [revisions, ${ver_a}, ${ver_b}]"
	fi

	num_part_a=${parts_a[cur_idx_a]#r}
	num_part_a=${num_part_a##+(0)}
	: ${num_part_a:=0}
	num_part_b=${parts_b[cur_idx_b]#r}
	num_part_b=${num_part_b##+(0)}
	: ${num_part_b:=0}

	((num_part_a < num_part_b)) && eshopts_pop && return 1
	((num_part_a > num_part_b)) && eshopts_pop && return 3

	### no differences.
	eshopts_pop
	return 2
	}

	# @FUNCTION: version_sort
	# @USAGE: <version> [more versions...]
	# @DESCRIPTION:
	# Returns its parameters sorted, highest version last. We're using a quadratic
	# algorithm for simplicity, so don't call it with more than a few dozen items.
	# Uses version_compare, so be careful.
	version_sort() {
	eshopts_push -s extglob
	local items=
	local -i left=0
	items=("$@")
	while ((left < ${#items[@]})); do
	local -i lowest_idx=left
	local -i idx=lowest_idx+1
	while ((idx < ${#items[@]})); do
	version_compare "${items[lowest_idx]}" "${items[idx]}"
	[[ $? -eq 3 ]] && lowest_idx=idx
	idx+=1
	done
	local tmp=${items[lowest_idx]}
	items[lowest_idx]=${items[left]}
	items[left]=${tmp}
	left+=1
	done
	echo ${items[@]}
	eshopts_pop
	}

	# @FUNCTION: version_format_string
	# @USAGE: <format> [version]
	# @DESCRIPTION:
	# Reformat complicated version strings. The first argument is the string
	# to reformat with while the rest of the args are passed on to the
	# get_version_components function. You should make sure to single quote
	# the first argument since it'll have variables that get delayed expansions.
	# @EXAMPLE:
	# P="cow-hat-1.2.3_p4"
	# MY_P=$(version_format_string '${PN}_source_$1_$2-$3_$4')
	# Now MY_P will be: cow-hat_source_1_2-3_p4
	version_format_string() {
	local fstr=$1
	shift
	set -- $(get_version_components "$@")
	eval echo "${fstr}"
	}

	fi