#!/bin/bash
# Copyright 2017 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

# build.release builds and publishes a new Go+BoringCrypto release.
# After running this script, the change to the RELEASES file should be
# sent out for review and committed to the repository (but the release
# is already done, so there's not much to review).

set -e

case "$#" in
0)
	rev=HEAD;;
1)
	rev="$1";;
*)
	echo 'usage: build.release [git-rev]' >&2
	exit 2
esac

# Determine commit to use.
commit=$(git rev-parse "$rev" | awk '{print substr($1, 1, 12)}')
if [ "$commit" = "" ]; then
	echo 'cannot find commit in git history' >&2
	exit 2
fi

# Determine base Go release from tags.
base=$(git log --decorate=short --oneline "$rev" | grep 'tag: go' | sed 1q | sed 's/[),].*//; s/.*tag: //')
if [ "$base" = "" ]; then
	echo "cannot find go release tag in git history for $rev" >&2
	exit 2
fi

# Determine boring crypto version from file.
boring=$(git show "$commit:misc/boring/VERSION")
if [ "$boring" = "" ]; then
	echo "missing BORINGVERSION file in $commit" >&2
	exit 2
fi

# Make sure we're not redefining a published release.
version="${base}b${boring}"
if grep "^$version " RELEASES >/dev/null; then
	echo "found $version in RELEASES - not rereleasing" >&2
	exit 2
fi

# Show what's going on, while the release builds.
# Good time for user to type ^C if something is wrong.
echo >&2
echo "building $version from $commit" >&2
echo >&2
git log -n1 "$commit" >&2
echo >&2

# Build the release tool in a temporary GOPATH.
dir=$(mktemp -d)
trap "rm -rf $dir" EXIT
export GOPATH="$dir"
export GOBIN="$dir"
go get -u golang.org/x/build/cmd/release

# Build the release.
sha() {
    if hash sha256sum 2>/dev/null; then
        sha256sum "$@"
    else
        shasum -a 256 "$@"
    fi
}
shortgo=$(echo "$base" | perl -pe 's/(go\d+\.\d+)(\.\d+|rc\d+)/$1/')
$dir/release -target linux-amd64 -rev "$commit" -version "$version" -tools "release-branch.$shortgo"
$dir/release -target src -rev "$commit" -version "$version" -tools "release-branch.$shortgo"
output="$version.linux-amd64.tar.gz"
ls -l "$output"
sha256=$(sha "$output" | awk '{print $1}')
outputsrc="$version.src.tar.gz"
ls -l "$outputsrc"
sha256src=$(sha "$outputsrc" | awk '{print $1}')

trap "rm -f /tmp/go.release.$$ /tmp/go.nm.$$" EXIT
tar -xzf "$output" -O go/bin/go >/tmp/go.release.$$
go tool nm /tmp/go.release.$$ >/tmp/go.nm.$$
if ! grep crypto/sha1.boringNewSHA1 /tmp/go.nm.$$ >/dev/null; then
	echo 'built release but did NOT find sha1.boringNewSHA1 in go command!' >&2
	exit 2
fi
if egrep 'crypto/sha1\.\(\*digest\)' /tmp/go.nm.$$ >/dev/null; then
	echo 'built release but DID find sha1.(*digest) in go command unexpectedly!' >&2
	exit 2
fi

# Publish the release.
gsutil cp "$output" gs://go-boringcrypto/
url="https://go-boringcrypto.storage.googleapis.com/$output"
gsutil cp "$outputsrc" gs://go-boringcrypto/
urlsrc="https://go-boringcrypto.storage.googleapis.com/$outputsrc"

# Record that it was published.
echo "$version $commit linux-amd64 $url $sha256" >>RELEASES
echo "$version $commit src $urlsrc $sha256src" >>RELEASES