make-release

#!/bin/sh -e

version="$1"
last_release="$2"

if [ 1 -ne $# -a 2 -ne $# ]; then
    echo "usage: $(basename $0) VERSION [LAST-RELEASE]" 2>&1
    exit 1
elif ! expr "$1" : 'v[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*' > /dev/null; then
    echo "$(basename $0): $version should be of the form v1.2.3" 2>&1
    exit 1
elif git rev-parse "$version" -- >/dev/null 2>&1; then
    echo "$(basename $0): git repository already contains $version" 2>&1
    exit 1
fi

find_default_last_release() {
    local next=
    while read line; do
	if [ "$version" == "$line" ]; then
	    next=1
	elif [ 1 == "$next" ]; then
	    echo "$line"
	    return
	fi
    done
}

if [ -z "$last_release" ]; then
    default_last_release=$((echo $version; git tag -l "v*.*.*") | \
			       sort -rVu | find_default_last_release)
    default_last_release=${default_last_release:-x}
    printf "Previous release or 'x' for none ($default_last_release)? "
    read last_release
    if [ -z "$last_release" ]; then
	last_release="$default_last_release"
    fi
fi

if [ x == "$last_release" ]; then
    last_release=
elif ! git rev-parse "$last_release" -- >/dev/null; then
    echo "$(basename $0): no commit $last_release" 2>&1
    exit 1
fi

./make-go1

parent=$(git rev-parse go1^)
tree=$(git rev-parse go1^{tree})

commit=$(echo "create release $version" | \
    git commit-tree -p $parent ${last_release:+-p} $last_release $tree)
git tag "$version" "$commit"

if github=$(git remote -v | sed -ne '/git@github.com/{s/[ 	].*//p;q;}')
then
    cat <<EOF
Now you may want to run:

    git push $github -f go1
    git push $github $version

EOF
fi