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#! /bin/sh
#
# Copyright (C) 2019 Free Software Foundation, Inc.
# Written by Bruno Haible <bruno@clisp.org>, 2019.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
# Program that manages the subdirectories of a git checkout of a package
# that come from other packages (called "dependency packages").
#
# This program is similar in spirit to 'git submodule', with three
# essential differences:
#
# 1) Its options are easy to remember, and do not require knowledge of
# 'git submodule'.
#
# 2) The developer may choose to work on a different checkout for each
# dependency package. This is important when the developer is
# preparing simultaneous changes to the package and the dependency
# package, or is using the dependency package in several packages.
#
# The developer indicates this different checkout by setting the
# environment variable <SUBDIR>_SRCDIR (e.g. GNULIB_SRCDIR) to point to it.
#
# 3) The package maintainer may choose to use or not use git submodules.
#
# The advantages of management through a git submodule are:
# - Changes to the dependency package cannot suddenly break your package.
# In other words, when there is an incompatible change that will cause
# a breakage, you can fix things at your pace; you are not forced to
# cope with such breakages in an emergency.
# - When you need to make a change as a response to a change in the
# dependency package, your co-developers cannot accidentally mix things
# up (for example, use a combination of your newest change with an
# older version of the dependency package).
#
# The advantages of management without a git submodule (just as a plain
# subdirectory, let's call it a "subcheckout") are:
# - The simplicity: you are conceptually always using the newest revision
# of the dependency package.
# - You don't have to remember to periodially upgrade the dependency.
# Upgrading the dependency is an implicit operation.
# This program is meant to be copied to the top-level directory of the package,
# together with a configuration file. The configuration is supposed to be
# named '.gitmodules' and to define:
# * The git submodules, as described in "man 5 gitmodules" or
# <https://git-scm.com/docs/gitmodules>. For example:
#
# [submodule "gnulib"]
# url = git://git.savannah.gnu.org/gnulib.git
# path = gnulib
#
# You don't add this piece of configuration to .gitmodules manually. Instead,
# you would invoke
# $ git submodule add --name "gnulib" -- git://git.savannah.gnu.org/gnulib.git gnulib
#
# * The subdirectories that are not git submodules, in a similar syntax. For
# example:
#
# [subcheckout "gnulib"]
# url = git://git.savannah.gnu.org/gnulib.git
# path = gnulib
#
# Here the URL is the one used for anonymous checkouts of the dependency
# package. If the developer needs a checkout with write access, they can
# either set the GNULIB_SRCDIR environment variable to point to that checkout
# or modify the gnulib/.git/config file to enter a different URL.
scriptname="$0"
scriptversion='2019-04-01'
nl='
'
IFS=" "" $nl"
# func_usage
# outputs to stdout the --help usage message.
func_usage ()
{
echo "\
Usage: gitsub.sh pull [SUBDIR]
gitsub.sh upgrade [SUBDIR]
gitsub.sh checkout SUBDIR REVISION
Operations:
gitsub.sh pull [GIT_OPTIONS] [SUBDIR]
You should perform this operation after 'git clone ...' and after
every 'git pull'.
It brings your checkout in sync with what the other developers of
your package have committed and pushed.
If an environment variable <SUBDIR>_SRCDIR is set, with a non-empty
value, nothing is done for this SUBDIR.
Supported GIT_OPTIONS (for expert git users) are:
--reference <repository>
--depth <depth>
--recursive
If no SUBDIR is specified, the operation applies to all dependencies.
gitsub.sh upgrade [SUBDIR]
You should perform this operation periodically, to ensure currency
of the dependency package revisions that you use.
This operation pulls and checks out the changes that the developers
of the dependency package have committed and pushed.
If an environment variable <SUBDIR>_SRCDIR is set, with a non-empty
value, nothing is done for this SUBDIR.
If no SUBDIR is specified, the operation applies to all dependencies.
gitsub.sh checkout SUBDIR REVISION
Checks out a specific revision for a dependency package.
If an environment variable <SUBDIR>_SRCDIR is set, with a non-empty
value, this operation fails.
This script requires the git program in the PATH and an internet connection.
"
}
# func_version
# outputs to stdout the --version message.
func_version ()
{
year=`echo "$scriptversion" | sed -e 's/^\(....\)-.*/\1/'`
echo "\
gitsub.sh (GNU gnulib) $scriptversion
Copyright (C) 2019-$year Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
"
printf "Written by %s.\n" "Bruno Haible"
}
# func_fatal_error message
# outputs to stderr a fatal error message, and terminates the program.
# Input:
# - scriptname name of this program
func_fatal_error ()
{
echo "$scriptname: *** $1" 1>&2
echo "$scriptname: *** Stop." 1>&2
exit 1
}
# func_warning message
# Outputs to stderr a warning message,
func_warning ()
{
echo "gitsub.sh: warning: $1" 1>&2
}
# func_note message
# Outputs to stdout a note message,
func_note ()
{
echo "gitsub.sh: note: $1"
}
# Unset CDPATH. Otherwise, output from 'cd dir' can surprise callers.
(unset CDPATH) >/dev/null 2>&1 && unset CDPATH
# Command-line option processing.
mode=
while test $# -gt 0; do
case "$1" in
--help | --hel | --he | --h )
func_usage
exit $? ;;
--version | --versio | --versi | --vers | --ver | --ve | --v )
func_version
exit $? ;;
-- )
# Stop option processing
shift
break ;;
-* )
echo "gitsub.sh: unknown option $1" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1 ;;
* )
break ;;
esac
done
if test $# = 0; then
echo "gitsub.sh: missing operation argument" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1
fi
case "$1" in
pull | upgrade | checkout )
mode="$1"
shift ;;
*)
echo "gitsub.sh: unknown operation '$1'" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1 ;;
esac
if { test $mode = upgrade && test $# -gt 1; } \
|| { test $mode = checkout && test $# -gt 2; }; then
echo "gitsub.sh: too many arguments in '$mode' mode" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1
fi
if test $# = 0 && test $mode = checkout; then
echo "gitsub.sh: too few arguments in '$mode' mode" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1
fi
# Read the configuration.
# Output:
# - subcheckout_names space-separated list of subcheckout names
# - submodule_names space-separated list of submodule names
if test -f .gitmodules; then
subcheckout_names=`git config --file .gitmodules --get-regexp --name-only 'subcheckout\..*\.url' | sed -e 's/^subcheckout\.//' -e 's/\.url$//' | tr -d '\r' | tr '\n' ' '`
submodule_names=`git config --file .gitmodules --get-regexp --name-only 'submodule\..*\.url' | sed -e 's/^submodule\.//' -e 's/\.url$//' | tr -d '\r' | tr '\n' ' '`
else
subcheckout_names=
submodule_names=
fi
# func_validate SUBDIR
# Verifies that the state on the file system is in sync with the declarations
# in the configuration file.
# Input:
# - subcheckout_names space-separated list of subcheckout names
# - submodule_names space-separated list of submodule names
# Output:
# - srcdirvar Environment that the user can set
# - srcdir Value of the environment variable
# - path if $srcdir = "": relative path of the subdirectory
# - needs_init if $srcdir = "" and $path is not yet initialized:
# true
# - url if $srcdir = "" and $path is not yet initialized:
# the repository URL
func_validate ()
{
srcdirvar=`echo "$1" | LC_ALL=C sed -e 's/[^a-zA-Z0-9]/_/g' | LC_ALL=C tr '[a-z]' '[A-Z]'`"_SRCDIR"
eval 'srcdir=$'"$srcdirvar"
path=
url=
if test -n "$srcdir"; then
func_note "Ignoring '$1' because $srcdirvar is set."
else
found=false
needs_init=
case " $subcheckout_names " in *" $1 "*)
found=true
# It ought to be a subcheckout.
path=`git config --file .gitmodules "subcheckout.$1.path"`
if test -z "$path"; then
path="$1"
fi
if test -d "$path"; then
if test -d "$path/.git"; then
# It's a plain checkout.
:
else
if test -f "$path/.git"; then
# It's a submodule.
func_fatal_error "Subdirectory '$path' is supposed to be a plain checkout, but it is a submodule."
else
func_warning "Ignoring '$path' because it exists but is not a git checkout."
fi
fi
else
# The subdir does not yet exist.
needs_init=true
url=`git config --file .gitmodules "subcheckout.$1.url"`
if test -z "$url"; then
func_fatal_error "Property subcheckout.$1.url is not defined in .gitmodules"
fi
fi
;;
esac
case " $submodule_names " in *" $1 "*)
found=true
# It ought to be a submodule.
path=`git config --file .gitmodules "submodule.$1.path"`
if test -z "$path"; then
path="$1"
fi
if test -d "$path"; then
if test -d "$path/.git" || test -f "$path/.git"; then
# It's likely a submodule.
:
else
path_if_empty=`find "$path" -prune -empty 2>/dev/null`
if test -n "$path_if_empty"; then
# The subdir is empty.
needs_init=true
else
# The subdir is not empty.
# It is important to report an error, because we don't want to erase
# the user's files and 'git submodule update gnulib' sometimes reports
# "fatal: destination path '$path' already exists and is not an empty directory."
# but sometimes does not.
func_fatal_error "Subdir '$path' exists but is not a git checkout."
fi
fi
else
# The subdir does not yet exist.
needs_init=true
fi
# Another way to determine needs_init could be:
# if git submodule status "$path" | grep '^-' > /dev/null; then
# needs_init=true
# fi
if test -n "$needs_init"; then
url=`git config --file .gitmodules "submodule.$1.url"`
if test -z "$url"; then
func_fatal_error "Property submodule.$1.url is not defined in .gitmodules"
fi
fi
;;
esac
if ! $found; then
func_fatal_error "Subdir '$1' is not configured as a subcheckout or a submodule in .gitmodules"
fi
fi
}
# func_cleanup_current_git_clone
# Cleans up the current 'git clone' operation.
# Input:
# - path
func_cleanup_current_git_clone ()
{
rm -rf "$path"
func_fatal_error "git clone failed"
}
# func_pull SUBDIR GIT_OPTIONS
# Implements the 'pull' operation.
func_pull ()
{
func_validate "$1"
if test -z "$srcdir"; then
case " $subcheckout_names " in *" $1 "*)
# It's a subcheckout.
if test -d "$path"; then
if test -d "$path/.git"; then
(cd "$path" && git pull) || func_fatal_error "git operation failed"
fi
else
# The subdir does not yet exist. Create a plain checkout.
trap func_cleanup_current_git_clone 1 2 13 15
git clone $2 "$url" "$path" || func_cleanup_current_git_clone
trap - 1 2 13 15
fi
;;
esac
case " $submodule_names " in *" $1 "*)
# It's a submodule.
if test -n "$needs_init"; then
# Create a submodule checkout.
git submodule init -- "$path" && git submodule update $2 -- "$path" || func_fatal_error "git operation failed"
else
# See https://stackoverflow.com/questions/1030169/easy-way-to-pull-latest-of-all-git-submodules
# https://stackoverflow.com/questions/4611512/is-there-a-way-to-make-git-pull-automatically-update-submodules
git submodule update "$path" || func_fatal_error "git operation failed"
fi
;;
esac
fi
}
# func_upgrade SUBDIR
# Implements the 'upgrade' operation.
func_upgrade ()
{
func_validate "$1"
if test -z "$srcdir"; then
if test -d "$path"; then
case " $subcheckout_names " in *" $1 "*)
# It's a subcheckout.
if test -d "$path/.git"; then
(cd "$path" && git pull) || func_fatal_error "git operation failed"
fi
;;
esac
case " $submodule_names " in *" $1 "*)
# It's a submodule.
if test -z "$needs_init"; then
(cd "$path" && git fetch && git merge origin/master) || func_fatal_error "git operation failed"
fi
;;
esac
else
# The subdir does not yet exist.
func_fatal_error "Subdirectory '$path' does not exist yet. Use 'gitsub.sh pull' to create it."
fi
fi
}
# func_checkout SUBDIR REVISION
# Implements the 'checkout' operation.
func_checkout ()
{
func_validate "$1"
if test -z "$srcdir"; then
if test -d "$path"; then
case " $subcheckout_names " in *" $1 "*)
# It's a subcheckout.
if test -d "$path/.git"; then
(cd "$path" && git checkout "$2") || func_fatal_error "git operation failed"
fi
;;
esac
case " $submodule_names " in *" $1 "*)
# It's a submodule.
if test -z "$needs_init"; then
(cd "$path" && git checkout "$2") || func_fatal_error "git operation failed"
fi
;;
esac
else
# The subdir does not yet exist.
func_fatal_error "Subdirectory '$path' does not exist yet. Use 'gitsub.sh pull' to create it."
fi
fi
}
case "$mode" in
pull )
git_options=""
while test $# -gt 0; do
case "$1" in
--reference=* | --depth=* | --recursive)
git_options="$git_options $1"
shift
;;
--reference | --depth)
git_options="$git_options $1 $2"
shift; shift
;;
*)
break
;;
esac
done
if test $# -gt 1; then
echo "gitsub.sh: too many arguments in '$mode' mode" 1>&2
echo "Try 'gitsub.sh --help' for more information." 1>&2
exit 1
fi
if test $# = 0; then
for sub in $subcheckout_names $submodule_names; do
func_pull "$sub" "$git_options"
done
else
valid=false
for sub in $subcheckout_names $submodule_names; do
if test "$sub" = "$1"; then
valid=true
fi
done
if $valid; then
func_pull "$1" "$git_options"
else
func_fatal_error "Subdir '$1' is not configured as a subcheckout or a submodule in .gitmodules"
fi
fi
;;
upgrade )
if test $# = 0; then
for sub in $subcheckout_names $submodule_names; do
func_upgrade "$sub"
done
else
valid=false
for sub in $subcheckout_names $submodule_names; do
if test "$sub" = "$1"; then
valid=true
fi
done
if $valid; then
func_upgrade "$1"
else
func_fatal_error "Subdir '$1' is not configured as a subcheckout or a submodule in .gitmodules"
fi
fi
;;
checkout )
valid=false
for sub in $subcheckout_names $submodule_names; do
if test "$sub" = "$1"; then
valid=true
fi
done
if $valid; then
func_checkout "$1" "$2"
else
func_fatal_error "Subdir '$1' is not configured as a subcheckout or a submodule in .gitmodules"
fi
;;
esac