#!/bin/sh

# **********************************************************
# Copyright (c) 2014-2015 Google, Inc.    All rights reserved.
# **********************************************************

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# * Neither the name of Google, Inc. nor the names of its contributors may be
#   used to endorse or promote products derived from this software without
#   specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
# DAMAGE.

# This is the pre-commit git hook, which is run when a developer attempts
# to commit locally.

# Prevent committing to master
# The --short option is too recent to rely on so we use a bash expansion
# to remove refs/heads/.
branch=`git symbolic-ref -q HEAD`
if [ "${branch##*/}" = "master" ]; then
    exec 1>&2
    cat <<\EOF
Error: it looks like you're committing on master.
Use a topic branch instead.
Aborting commit.
EOF
    exit 1
fi

# Avoid mistakes in author configurations:
AUTHORINFO=$(git var GIT_AUTHOR_IDENT) || exit 1
NAME=$(printf '%s\n' "${AUTHORINFO}" | sed -n 's/^\(.*\) <.*$/\1/p')
EMAIL=$(printf '%s\n' "${AUTHORINFO}" | sed -n 's/^.* <\(.*\)> .*$/\1/p')
existing=`git log --author="${NAME} <${EMAIL}>" -n 1`
if [ -z "${existing}" ]; then
    printf "WARNING: \"${NAME} <${EMAIL}>\" is a new author.\n"
    printf "Please double-check that it is configured properly.\n"
fi

# XXX: The following lines are a verbatim copy from
# drmemory/make/git/hook-pre-commit.sh. In the future, we may need to
# create a separate dedicated repository, a submodule in both that provides
# shared config files.
# Prevent mistaken submodule commits by checking whether committing
# submodule + other stuff and if so bail if the submodule version is older.
# We want to allow a submodule-only rollback.
# XXX: this relies on several unix utilities which we assume are available
# on Windows.
libipt_diff=`git diff --cached third_party/libipt`
if ! test -z "$libipt_diff" ; then
    # third_party/libipt submodule is changed in the diff
    others=`git diff --cached --name-only | grep -v third_party/libipt`
    if ! test -z "$libipt_diff" ; then
        # There's at least one other change.  Let's run git log on
        # oldhash..newhash to see which is newer.
        range=`git diff --cached third_party/libipt | grep Subproject | awk '{print $NF}' | xargs | sed 's/ /../'`
        between=`cd third_party/libipt && git log --pretty=oneline $range`
        if test -z "$between" ; then
            exec 1>&2
            cat <<\EOF
Error: the third_party/libipt submodule is being rolled back.
This is likely a mistake: did you pull but not run git submodule update?
Aborting commit.
EOF
            exit 1
        fi
    fi
fi

# XXX: move code style checks here from runsuite.cmake?