From: "Michał Górny" <mgorny@gentoo.org>
To: gentoo-dev@lists.gentoo.org
Subject: Re: [gentoo-dev] [PATCH v3] estack.eclass: Split estack* logic from eutils
Date: Sat, 18 Mar 2017 08:35:12 +0100 [thread overview]
Message-ID: <1489822512.1289.5.camel@gentoo.org> (raw)
In-Reply-To: <20170312101332.10442-1-mgorny@gentoo.org>
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On nie, 2017-03-12 at 11:13 +0100, Michał Górny wrote:
> Split the estack_* and related functions from eutils into a dedicated
> estack.eclass. Those functions have significant complexity and are not
> used frequently, therefore they benefit from having a separate file
> and an explicit dedicated maintainer.
>
> The new eclass is implicitly inherited by eutils to preserve
> compatibility. However, the inherit will be removed in EAPI 7,
> and the ebuilds should switch to using estack directly.
>
> Thanks to Ulrich Müller for doing the research on this.
>
> // v3: also rename&update tests
> ---
> eclass/estack.eclass | 217 +++++++++++++++++++++
> eclass/eutils.eclass | 210 +-------------------
> .../tests/{eutils_eshopts.sh => estack_eshopts.sh} | 4 +-
> .../tests/{eutils_estack.sh => estack_estack.sh} | 4 +-
> eclass/tests/{eutils_evar.sh => estack_evar.sh} | 4 +-
> 5 files changed, 230 insertions(+), 209 deletions(-)
> create mode 100644 eclass/estack.eclass
> rename eclass/tests/{eutils_eshopts.sh => estack_eshopts.sh} (93%)
> rename eclass/tests/{eutils_estack.sh => estack_estack.sh} (93%)
> rename eclass/tests/{eutils_evar.sh => estack_evar.sh} (96%)
>
> diff --git a/eclass/estack.eclass b/eclass/estack.eclass
> new file mode 100644
> index 000000000000..19c388f3d8d2
> --- /dev/null
> +++ b/eclass/estack.eclass
> @@ -0,0 +1,217 @@
> +# Copyright 1999-2017 Gentoo Foundation
> +# Distributed under the terms of the GNU General Public License v2
> +
> +# @ECLASS: estack.eclass
> +# @MAINTAINER:
> +# base-system@gentoo.org
> +# @BLURB: stack-like value storage support
> +# @DESCRIPTION:
> +# Support for storing values on stack-like variables.
> +
> +if [[ -z ${_ESTACK_ECLASS} ]]; then
> +
> +# @FUNCTION: estack_push
> +# @USAGE: <stack> [items to push]
> +# @DESCRIPTION:
> +# Push any number of items onto the specified stack. Pick a name that
> +# is a valid variable (i.e. stick to alphanumerics), and push as many
> +# items as you like onto the stack at once.
> +#
> +# The following code snippet will echo 5, then 4, then 3, then ...
> +# @CODE
> +# estack_push mystack 1 2 3 4 5
> +# while estack_pop mystack i ; do
> +# echo "${i}"
> +# done
> +# @CODE
> +estack_push() {
> + [[ $# -eq 0 ]] && die "estack_push: incorrect # of arguments"
> + local stack_name="_ESTACK_$1_" ; shift
> + eval ${stack_name}+=\( \"\$@\" \)
> +}
> +
> +# @FUNCTION: estack_pop
> +# @USAGE: <stack> [variable]
> +# @DESCRIPTION:
> +# Pop a single item off the specified stack. If a variable is specified,
> +# the popped item is stored there. If no more items are available, return
> +# 1, else return 0. See estack_push for more info.
> +estack_pop() {
> + [[ $# -eq 0 || $# -gt 2 ]] && die "estack_pop: incorrect # of arguments"
> +
> + # We use the fugly _estack_xxx var names to avoid collision with
> + # passing back the return value. If we used "local i" and the
> + # caller ran `estack_pop ... i`, we'd end up setting the local
> + # copy of "i" rather than the caller's copy. The _estack_xxx
> + # garbage is preferable to using $1/$2 everywhere as that is a
> + # bit harder to read.
> + local _estack_name="_ESTACK_$1_" ; shift
> + local _estack_retvar=$1 ; shift
> + eval local _estack_i=\${#${_estack_name}\[@\]}
> + # Don't warn -- let the caller interpret this as a failure
> + # or as normal behavior (akin to `shift`)
> + [[ $(( --_estack_i )) -eq -1 ]] && return 1
> +
> + if [[ -n ${_estack_retvar} ]] ; then
> + eval ${_estack_retvar}=\"\${${_estack_name}\[${_estack_i}\]}\"
> + fi
> + eval unset \"${_estack_name}\[${_estack_i}\]\"
> +}
> +
> +# @FUNCTION: evar_push
> +# @USAGE: <variable to save> [more vars to save]
> +# @DESCRIPTION:
> +# This let's you temporarily modify a variable and then restore it (including
> +# set vs unset semantics). Arrays are not supported at this time.
> +#
> +# This is meant for variables where using `local` does not work (such as
> +# exported variables, or only temporarily changing things in a func).
> +#
> +# For example:
> +# @CODE
> +# evar_push LC_ALL
> +# export LC_ALL=C
> +# ... do some stuff that needs LC_ALL=C set ...
> +# evar_pop
> +#
> +# # You can also save/restore more than one var at a time
> +# evar_push BUTTERFLY IN THE SKY
> +# ... do stuff with the vars ...
> +# evar_pop # This restores just one var, SKY
> +# ... do more stuff ...
> +# evar_pop 3 # This pops the remaining 3 vars
> +# @CODE
> +evar_push() {
> + local var val
> + for var ; do
> + [[ ${!var+set} == "set" ]] \
> + && val=${!var} \
> + || val="unset_76fc3c462065bb4ca959f939e6793f94"
> + estack_push evar "${var}" "${val}"
> + done
> +}
> +
> +# @FUNCTION: evar_push_set
> +# @USAGE: <variable to save> [new value to store]
> +# @DESCRIPTION:
> +# This is a handy shortcut to save and temporarily set a variable. If a value
> +# is not specified, the var will be unset.
> +evar_push_set() {
> + local var=$1
> + evar_push ${var}
> + case $# in
> + 1) unset ${var} ;;
> + 2) printf -v "${var}" '%s' "$2" ;;
> + *) die "${FUNCNAME}: incorrect # of args: $*" ;;
> + esac
> +}
> +
> +# @FUNCTION: evar_pop
> +# @USAGE: [number of vars to restore]
> +# @DESCRIPTION:
> +# Restore the variables to the state saved with the corresponding
> +# evar_push call. See that function for more details.
> +evar_pop() {
> + local cnt=${1:-bad}
> + case $# in
> + 0) cnt=1 ;;
> + 1) isdigit "${cnt}" || die "${FUNCNAME}: first arg must be a number: $*" ;;
> + *) die "${FUNCNAME}: only accepts one arg: $*" ;;
> + esac
> +
> + local var val
> + while (( cnt-- )) ; do
> + estack_pop evar val || die "${FUNCNAME}: unbalanced push"
> + estack_pop evar var || die "${FUNCNAME}: unbalanced push"
> + [[ ${val} == "unset_76fc3c462065bb4ca959f939e6793f94" ]] \
> + && unset ${var} \
> + || printf -v "${var}" '%s' "${val}"
> + done
> +}
> +
> +# @FUNCTION: eshopts_push
> +# @USAGE: [options to `set` or `shopt`]
> +# @DESCRIPTION:
> +# Often times code will want to enable a shell option to change code behavior.
> +# Since changing shell options can easily break other pieces of code (which
> +# assume the default state), eshopts_push is used to (1) push the current shell
> +# options onto a stack and (2) pass the specified arguments to set.
> +#
> +# If the first argument is '-s' or '-u', we assume you want to call `shopt`
> +# rather than `set` as there are some options only available via that.
> +#
> +# A common example is to disable shell globbing so that special meaning/care
> +# may be used with variables/arguments to custom functions. That would be:
> +# @CODE
> +# eshopts_push -o noglob
> +# for x in ${foo} ; do
> +# if ...some check... ; then
> +# eshopts_pop
> +# return 0
> +# fi
> +# done
> +# eshopts_pop
> +# @CODE
> +eshopts_push() {
> + if [[ $1 == -[su] ]] ; then
> + estack_push eshopts "$(shopt -p)"
> + [[ $# -eq 0 ]] && return 0
> + shopt "$@" || die "${FUNCNAME}: bad options to shopt: $*"
> + else
> + estack_push eshopts $-
> + [[ $# -eq 0 ]] && return 0
> + set "$@" || die "${FUNCNAME}: bad options to set: $*"
> + fi
> +}
> +
> +# @FUNCTION: eshopts_pop
> +# @USAGE:
> +# @DESCRIPTION:
> +# Restore the shell options to the state saved with the corresponding
> +# eshopts_push call. See that function for more details.
> +eshopts_pop() {
> + local s
> + estack_pop eshopts s || die "${FUNCNAME}: unbalanced push"
> + if [[ ${s} == "shopt -"* ]] ; then
> + eval "${s}" || die "${FUNCNAME}: sanity: invalid shopt options: ${s}"
> + else
> + set +$- || die "${FUNCNAME}: sanity: invalid shell settings: $-"
> + set -${s} || die "${FUNCNAME}: sanity: unable to restore saved shell settings: ${s}"
> + fi
> +}
> +
> +# @FUNCTION: eumask_push
> +# @USAGE: <new umask>
> +# @DESCRIPTION:
> +# Set the umask to the new value specified while saving the previous
> +# value onto a stack. Useful for temporarily changing the umask.
> +eumask_push() {
> + estack_push eumask "$(umask)"
> + umask "$@" || die "${FUNCNAME}: bad options to umask: $*"
> +}
> +
> +# @FUNCTION: eumask_pop
> +# @USAGE:
> +# @DESCRIPTION:
> +# Restore the previous umask state.
> +eumask_pop() {
> + [[ $# -eq 0 ]] || die "${FUNCNAME}: we take no options"
> + local s
> + estack_pop eumask s || die "${FUNCNAME}: unbalanced push"
> + umask ${s} || die "${FUNCNAME}: sanity: could not restore umask: ${s}"
> +}
> +
> +# @FUNCTION: isdigit
> +# @USAGE: <number> [more numbers]
> +# @DESCRIPTION:
> +# Return true if all arguments are numbers.
> +isdigit() {
> + local d
> + for d ; do
> + [[ ${d:-bad} == *[!0-9]* ]] && return 1
> + done
> + return 0
> +}
> +
> +_ESTACK_ECLASS=1
> +fi #_ESTACK_ECLASS
> diff --git a/eclass/eutils.eclass b/eclass/eutils.eclass
> index ac6a4854d17b..79ec00042a3f 100644
> --- a/eclass/eutils.eclass
> +++ b/eclass/eutils.eclass
> @@ -19,6 +19,13 @@ _EUTILS_ECLASS=1
>
> inherit multilib toolchain-funcs
>
> +# implicitly inherited (now split) eclasses
> +case ${EAPI:-0} in
> +0|1|2|3|4|5|6)
> + inherit estack
> + ;;
> +esac
> +
> # @FUNCTION: eqawarn
> # @USAGE: [message]
> # @DESCRIPTION:
> @@ -63,209 +70,6 @@ egit_clean() {
> find "$@" -type d -name '.git*' -prune -print0 | xargs -0 rm -rf
> }
>
> -# @FUNCTION: estack_push
> -# @USAGE: <stack> [items to push]
> -# @DESCRIPTION:
> -# Push any number of items onto the specified stack. Pick a name that
> -# is a valid variable (i.e. stick to alphanumerics), and push as many
> -# items as you like onto the stack at once.
> -#
> -# The following code snippet will echo 5, then 4, then 3, then ...
> -# @CODE
> -# estack_push mystack 1 2 3 4 5
> -# while estack_pop mystack i ; do
> -# echo "${i}"
> -# done
> -# @CODE
> -estack_push() {
> - [[ $# -eq 0 ]] && die "estack_push: incorrect # of arguments"
> - local stack_name="_ESTACK_$1_" ; shift
> - eval ${stack_name}+=\( \"\$@\" \)
> -}
> -
> -# @FUNCTION: estack_pop
> -# @USAGE: <stack> [variable]
> -# @DESCRIPTION:
> -# Pop a single item off the specified stack. If a variable is specified,
> -# the popped item is stored there. If no more items are available, return
> -# 1, else return 0. See estack_push for more info.
> -estack_pop() {
> - [[ $# -eq 0 || $# -gt 2 ]] && die "estack_pop: incorrect # of arguments"
> -
> - # We use the fugly _estack_xxx var names to avoid collision with
> - # passing back the return value. If we used "local i" and the
> - # caller ran `estack_pop ... i`, we'd end up setting the local
> - # copy of "i" rather than the caller's copy. The _estack_xxx
> - # garbage is preferable to using $1/$2 everywhere as that is a
> - # bit harder to read.
> - local _estack_name="_ESTACK_$1_" ; shift
> - local _estack_retvar=$1 ; shift
> - eval local _estack_i=\${#${_estack_name}\[@\]}
> - # Don't warn -- let the caller interpret this as a failure
> - # or as normal behavior (akin to `shift`)
> - [[ $(( --_estack_i )) -eq -1 ]] && return 1
> -
> - if [[ -n ${_estack_retvar} ]] ; then
> - eval ${_estack_retvar}=\"\${${_estack_name}\[${_estack_i}\]}\"
> - fi
> - eval unset \"${_estack_name}\[${_estack_i}\]\"
> -}
> -
> -# @FUNCTION: evar_push
> -# @USAGE: <variable to save> [more vars to save]
> -# @DESCRIPTION:
> -# This let's you temporarily modify a variable and then restore it (including
> -# set vs unset semantics). Arrays are not supported at this time.
> -#
> -# This is meant for variables where using `local` does not work (such as
> -# exported variables, or only temporarily changing things in a func).
> -#
> -# For example:
> -# @CODE
> -# evar_push LC_ALL
> -# export LC_ALL=C
> -# ... do some stuff that needs LC_ALL=C set ...
> -# evar_pop
> -#
> -# # You can also save/restore more than one var at a time
> -# evar_push BUTTERFLY IN THE SKY
> -# ... do stuff with the vars ...
> -# evar_pop # This restores just one var, SKY
> -# ... do more stuff ...
> -# evar_pop 3 # This pops the remaining 3 vars
> -# @CODE
> -evar_push() {
> - local var val
> - for var ; do
> - [[ ${!var+set} == "set" ]] \
> - && val=${!var} \
> - || val="unset_76fc3c462065bb4ca959f939e6793f94"
> - estack_push evar "${var}" "${val}"
> - done
> -}
> -
> -# @FUNCTION: evar_push_set
> -# @USAGE: <variable to save> [new value to store]
> -# @DESCRIPTION:
> -# This is a handy shortcut to save and temporarily set a variable. If a value
> -# is not specified, the var will be unset.
> -evar_push_set() {
> - local var=$1
> - evar_push ${var}
> - case $# in
> - 1) unset ${var} ;;
> - 2) printf -v "${var}" '%s' "$2" ;;
> - *) die "${FUNCNAME}: incorrect # of args: $*" ;;
> - esac
> -}
> -
> -# @FUNCTION: evar_pop
> -# @USAGE: [number of vars to restore]
> -# @DESCRIPTION:
> -# Restore the variables to the state saved with the corresponding
> -# evar_push call. See that function for more details.
> -evar_pop() {
> - local cnt=${1:-bad}
> - case $# in
> - 0) cnt=1 ;;
> - 1) isdigit "${cnt}" || die "${FUNCNAME}: first arg must be a number: $*" ;;
> - *) die "${FUNCNAME}: only accepts one arg: $*" ;;
> - esac
> -
> - local var val
> - while (( cnt-- )) ; do
> - estack_pop evar val || die "${FUNCNAME}: unbalanced push"
> - estack_pop evar var || die "${FUNCNAME}: unbalanced push"
> - [[ ${val} == "unset_76fc3c462065bb4ca959f939e6793f94" ]] \
> - && unset ${var} \
> - || printf -v "${var}" '%s' "${val}"
> - done
> -}
> -
> -# @FUNCTION: eshopts_push
> -# @USAGE: [options to `set` or `shopt`]
> -# @DESCRIPTION:
> -# Often times code will want to enable a shell option to change code behavior.
> -# Since changing shell options can easily break other pieces of code (which
> -# assume the default state), eshopts_push is used to (1) push the current shell
> -# options onto a stack and (2) pass the specified arguments to set.
> -#
> -# If the first argument is '-s' or '-u', we assume you want to call `shopt`
> -# rather than `set` as there are some options only available via that.
> -#
> -# A common example is to disable shell globbing so that special meaning/care
> -# may be used with variables/arguments to custom functions. That would be:
> -# @CODE
> -# eshopts_push -o noglob
> -# for x in ${foo} ; do
> -# if ...some check... ; then
> -# eshopts_pop
> -# return 0
> -# fi
> -# done
> -# eshopts_pop
> -# @CODE
> -eshopts_push() {
> - if [[ $1 == -[su] ]] ; then
> - estack_push eshopts "$(shopt -p)"
> - [[ $# -eq 0 ]] && return 0
> - shopt "$@" || die "${FUNCNAME}: bad options to shopt: $*"
> - else
> - estack_push eshopts $-
> - [[ $# -eq 0 ]] && return 0
> - set "$@" || die "${FUNCNAME}: bad options to set: $*"
> - fi
> -}
> -
> -# @FUNCTION: eshopts_pop
> -# @USAGE:
> -# @DESCRIPTION:
> -# Restore the shell options to the state saved with the corresponding
> -# eshopts_push call. See that function for more details.
> -eshopts_pop() {
> - local s
> - estack_pop eshopts s || die "${FUNCNAME}: unbalanced push"
> - if [[ ${s} == "shopt -"* ]] ; then
> - eval "${s}" || die "${FUNCNAME}: sanity: invalid shopt options: ${s}"
> - else
> - set +$- || die "${FUNCNAME}: sanity: invalid shell settings: $-"
> - set -${s} || die "${FUNCNAME}: sanity: unable to restore saved shell settings: ${s}"
> - fi
> -}
> -
> -# @FUNCTION: eumask_push
> -# @USAGE: <new umask>
> -# @DESCRIPTION:
> -# Set the umask to the new value specified while saving the previous
> -# value onto a stack. Useful for temporarily changing the umask.
> -eumask_push() {
> - estack_push eumask "$(umask)"
> - umask "$@" || die "${FUNCNAME}: bad options to umask: $*"
> -}
> -
> -# @FUNCTION: eumask_pop
> -# @USAGE:
> -# @DESCRIPTION:
> -# Restore the previous umask state.
> -eumask_pop() {
> - [[ $# -eq 0 ]] || die "${FUNCNAME}: we take no options"
> - local s
> - estack_pop eumask s || die "${FUNCNAME}: unbalanced push"
> - umask ${s} || die "${FUNCNAME}: sanity: could not restore umask: ${s}"
> -}
> -
> -# @FUNCTION: isdigit
> -# @USAGE: <number> [more numbers]
> -# @DESCRIPTION:
> -# Return true if all arguments are numbers.
> -isdigit() {
> - local d
> - for d ; do
> - [[ ${d:-bad} == *[!0-9]* ]] && return 1
> - done
> - return 0
> -}
> -
> # @VARIABLE: EPATCH_SOURCE
> # @DESCRIPTION:
> # Default directory to search for patches.
> diff --git a/eclass/tests/eutils_eshopts.sh b/eclass/tests/estack_eshopts.sh
> similarity index 93%
> rename from eclass/tests/eutils_eshopts.sh
> rename to eclass/tests/estack_eshopts.sh
> index 2e9bbb6d4612..606a17cfb053 100755
> --- a/eclass/tests/eutils_eshopts.sh
> +++ b/eclass/tests/estack_eshopts.sh
> @@ -1,10 +1,10 @@
> #!/bin/bash
> -# Copyright 1999-2015 Gentoo Foundation
> +# Copyright 1999-2017 Gentoo Foundation
> # Distributed under the terms of the GNU General Public License v2
>
> source tests-common.sh
>
> -inherit eutils
> +inherit estack
>
> test-it() {
> local s0 s1 s2
> diff --git a/eclass/tests/eutils_estack.sh b/eclass/tests/estack_estack.sh
> similarity index 93%
> rename from eclass/tests/eutils_estack.sh
> rename to eclass/tests/estack_estack.sh
> index c1fecf323133..4845243d3ae4 100755
> --- a/eclass/tests/eutils_estack.sh
> +++ b/eclass/tests/estack_estack.sh
> @@ -1,10 +1,10 @@
> #!/bin/bash
> -# Copyright 1999-2015 Gentoo Foundation
> +# Copyright 1999-2017 Gentoo Foundation
> # Distributed under the terms of the GNU General Public License v2
>
> source tests-common.sh
>
> -inherit eutils
> +inherit estack
>
> tbegin "initial stack state"
> estack_pop teststack
> diff --git a/eclass/tests/eutils_evar.sh b/eclass/tests/estack_evar.sh
> similarity index 96%
> rename from eclass/tests/eutils_evar.sh
> rename to eclass/tests/estack_evar.sh
> index f8db340f723d..29badba0079e 100755
> --- a/eclass/tests/eutils_evar.sh
> +++ b/eclass/tests/estack_evar.sh
> @@ -1,10 +1,10 @@
> #!/bin/bash
> -# Copyright 1999-2015 Gentoo Foundation
> +# Copyright 1999-2017 Gentoo Foundation
> # Distributed under the terms of the GNU General Public License v2
>
> source tests-common.sh
>
> -inherit eutils
> +inherit estack
>
> tbegin "simple push/pop"
> VAR=1
Merged.
--
Best regards,
Michał Górny
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prev parent reply other threads:[~2017-03-18 7:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-11 13:50 [gentoo-dev] [PATCH] estack.eclass: Split estack* logic from eutils Michał Górny
2017-03-11 14:25 ` Ulrich Mueller
2017-03-11 14:59 ` [gentoo-dev] [PATCH v2] " Michał Górny
2017-03-12 10:13 ` [gentoo-dev] [PATCH v3] " Michał Górny
2017-03-18 7:35 ` Michał Górny [this message]
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