src/minimize_jdk.sh

#!/bin/bash

# Copyright 2018 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This script creates from the full JDK a minimized version that only contains
# the specified JDK modules.

set -euo pipefail

if [ "$1" == "--allmodules" ]; then
  shift
  modules="ALL-MODULE-PATH"
else
  modules=$(cat "$2" | paste -sd "," - | tr -d '\r')
  # We have to add this module explicitly because jdeps doesn't find the
  # dependency on it but it is still necessary for TLSv1.3.
  modules="$modules,jdk.crypto.ec"
fi
fulljdk=$1
out=$3

UNAME=$(uname -s | tr 'A-Z' 'a-z')

if [[ "$UNAME" =~ msys_nt* ]]; then
  set -x
  mkdir "tmp.$$"
  cd "tmp.$$"
  unzip "../$fulljdk"
  cd zulu*
  ./bin/jlink --module-path ./jmods/ --add-modules "$modules" \
    --vm=server --strip-debug --no-man-pages \
    --output reduced
  cp DISCLAIMER readme.txt legal/java.base/ASSEMBLY_EXCEPTION \
    reduced/
  # These are necessary for --host_jvm_debug to work.
  cp bin/dt_socket.dll bin/jdwp.dll reduced/bin
  if [[ "$modules" != "ALL-MODULE-PATH" ]]; then
    # Only necessary for compilation, which doesn't happen with the minimal JDK.
    rm reduced/lib/ct.sym
  fi
  zip -r -9 ../reduced.zip reduced/
  cd ../..
  mv "tmp.$$/reduced.zip" "$out"
  rm -rf "tmp.$$"
else
  tar xf "$fulljdk"
  cd zulu*
  ./bin/jlink --module-path ./jmods/ --add-modules "$modules" \
    --vm=server --strip-debug --no-man-pages \
    --output reduced
  cp DISCLAIMER readme.txt legal/java.base/ASSEMBLY_EXCEPTION \
    reduced/
  # These are necessary for --host_jvm_debug to work.
  if [[ "$UNAME" =~ darwin ]]; then
    cp lib/libdt_socket.dylib lib/libjdwp.dylib reduced/lib
  else
    cp lib/libdt_socket.so lib/libjdwp.so reduced/lib
  fi
  if [[ "$modules" != "ALL-MODULE-PATH" ]]; then
    # Only necessary for compilation, which doesn't happen with the minimal JDK.
    rm reduced/lib/ct.sym
  fi
  GZIP=-9 tar -zcf ../reduced.tgz reduced
  cd ..
  mv reduced.tgz "$out"
fi