#!/bin/bash
THIS_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}"  )" >/dev/null 2>&1 && pwd )"
BUILD_DIR=/tmp/occlum_golang_toolchain
INSTALL_DIR=/opt/occlum/toolchains/golang
GO_VERSION="1.18.4"

if [[ $# -ge 1 ]];then
case $1 in
          --help|help)
               echo  "Usage:$0 [go1.16.3|go1.18.4]"
               exit
               ;;
          "go1.16.3"|"1.16.3"|"v1.16.3")
               GO_VERSION="1.16.3"
               ;;
          "go1.18.4"|"1.18.4"|"v1.18.4")
               GO_VERSION="1.18.4"
               ;;
     esac
fi

# Exit if any command fails
set -e

# Clean previous build and installation if any
rm -rf ${BUILD_DIR}
rm -rf ${INSTALL_DIR}

# Create the build directory
mkdir -p ${BUILD_DIR}
cd ${BUILD_DIR}

# Download Golang
git clone https://github.com/golang/go .
# Swtich to Golang 1.16.3 or Golang 1.18.4
git checkout -b go${GO_VERSION} tags/go${GO_VERSION}
# Apply the patch to adapt Golang to Occlum
git apply ${THIS_DIR}/adapt-golang${GO_VERSION}-to-occlum.patch

# Build Golang
cd src
./make.bash
mv ${BUILD_DIR} ${INSTALL_DIR}

# Generate the wrappers for Go
cat > ${INSTALL_DIR}/bin/occlum-go <<EOF
#!/bin/bash
OCCLUM_GCC="\$(which occlum-gcc)"
OCCLUM_GOFLAGS="-buildmode=pie \$GOFLAGS"
CC=\$OCCLUM_GCC GOFLAGS=\$OCCLUM_GOFLAGS ${INSTALL_DIR}/bin/go "\$@"
EOF

chmod +x ${INSTALL_DIR}/bin/occlum-go