#!/bin/bash

# Create a patch which backports the support/ subdirectory.

# Copyright (C) 2017-2018 Free Software Foundation, Inc.

# This file is part of the GNU C Library.

# The GNU C Library is free software; you can redistribute it and/or

# modify it under the terms of the GNU Lesser General Public

# License as published by the Free Software Foundation; either

# version 2.1 of the License, or (at your option) any later version.

# The GNU C Library 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

# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public

# License along with the GNU C Library; if not, see

# <http://www.gnu.org/licenses/>.

# This script does not backport the Makefile tweaks outside the

# support/ directory (which need to be backported separately), or the

# changes to test-skeleton.c (which should not be backported).

set -e

export LC_ALL=C

export GIT_CONFIG=/dev/null

export GTT_CONFIG_NOSYSTEM=0

export GIT_PAGER=

usage () {

    cat >&2 <

usage: $0 {patch|commit}

EOF

    exit 1

}

if test $# -ne 1 ; then

    usage

fi

command="$1"

case "$command" in

    patch|commit)

    ;;

    *)

	usage

	;;

esac

# The upstream branch to work on.

branch=origin/master

# The commit which added the support/ directory.

initial_commit=c23de0aacbeaa7a091609b35764bed931475a16d

# We backport the support directory and this script.  Directories need

# to end in a /.

patch_targets="support/ scripts/backport-support.sh"

latest_commit="$(git log --max-count=1 --pretty=format:%H "$branch" -- \

  $patch_targets)"

# Simplify the branch name somewhat for reporting.

branch_name="$(echo "$branch" | sed s,^origin/,,)"

command_patch () {

    cat <

This patch creates the contents of the support/ directory up to this

upstream commit on the $branch_name branch:

EOF

    git log --max-count=1 "$latest_commit"

    echo

    git diff "$initial_commit"^.."$latest_commit" $patch_targets

    echo "# Before applying the patch, run this command:" >&2

    echo "# rm -rf $patch_targets" >&2

}

command_commit () {

    git status --porcelain | while read line ; do

	echo "error: working copy is not clean, cannot commit" >&2

	exit 1

    done

    for path in $patch_targets; do

	echo "# Processing $path" >&2

	case "$path" in

	    [a-zA-Z0-9]*/)

		# Directory.

		git rm --cached --ignore-unmatch -r "$path"

		rm -rf "$path"

		git read-tree --prefix="$path" "$latest_commit":"$path"

		git checkout "$path"

		;;

	    *)

		# File.

		git show "$latest_commit":"$path" > "$path"

		git add "$path"

	esac

    done

    git commit -m "Synchronize support/ infrastructure with $branch_name

This commit updates the support/ subdirectory to

commit $latest_commit

on the $branch_name branch.

"

}

command_$command