opam-boot

#!/usr/bin/env bash
set -e

# Sensible defaults:
: ${OPAM_VERSION:="1.2.2"}
: ${OCAML_VERSION:="4.02.3"}
: ${OBJ:=`pwd`/_obj}

while [[ $# > 0 ]]; do
  key="$1"

  case $key in
    --opam)
    OPAM_VERSION="$2"
    shift # past argument
    ;;
    --ocaml)
    OCAML_VERSION="$2"
    shift # past argument
    ;;
    --obj)
    OBJ="$2"
    shift # past argument
    ;;
    build)
    BUILD="$2"
    shift # past argument
    ;;
    *)
    echo "Usage: $0 [--opam $OPAM_VERSION] [--ocaml $OCAML_VERSION] [--obj $OBJ] [build <name>]"
    echo ""
    echo "Construct an OCaml build environment from scratch with the given version"
    echo "of OPAM, the given OCaml version and place it in the given obj directory."
    echo ""
    echo "If the [build <name>] argument is given then a package is built from an opam"
    echo "file in the current directory and named <name>."
    exit 0
    ;;
  esac
  shift
done

ORIGINAL_DIR=`pwd`

mkdir -p ${OBJ}
ENV=${OBJ}/opam-env.sh
if [ -e ${ENV} ]; then
  . ${ENV}
fi
echo "export OPAMROOT=\"${OBJ}/opamroot\"" > ${ENV}
chmod a+x ${ENV}

mkdir -p ${OBJ}
PATH=${OBJ}/bin:$PATH
AVAILABLE_OPAM_VERSION=`opam --version 2>/dev/null || true`
AVAILABLE_OCAML_VERSION=`ocamlc -version 2>/dev/null || true`

FILE=opam-full-${OPAM_VERSION}.tar.gz
URL=https://github.com/ocaml/opam/releases/download/${OPAM_VERSION}/${FILE}

if [ "$OPAM_VERSION" = "$AVAILABLE_OPAM_VERSION" ]; then
  echo OPAM $OPAM_VERSION is already available.
else
  echo OPAM $OPAM_VERSION will be installed locally.
  cd ${OBJ}
  if [ ! -e ${FILE} ]; then
    curl -OL ${URL}
  fi
  tar -zxf ${FILE}
  cd opam-full-${OPAM_VERSION}
  if [ "" != "$AVAILABLE_OCAML_VERSION" ]; then
    # TODO: check whether available OCaml is new enough
    echo OCaml $AVAILABLE_OCAML_VERSION is available to compile OPAM.
    ./configure --prefix=${OBJ}
    make lib-ext
    make
  else
    echo OCaml is not available, performing a local installation
    make cold CONFIGURE_ARGS="--prefix=${OBJ}"
  fi
  make install
  echo "export PATH=$OBJ/bin:\$PATH" >> ${ENV}
  cd ${OBJ}
fi

export OPAMYES=1
export OPAMJOBS=2

. ${ENV}
if [ ! -d "${OPAMROOT}" ]; then
  if [ "$OCAML_VERSION" = "$AVAILABLE_OCAML_VERSION" ]; then
    opam init -n
  else
    opam init -n --comp=$OCAML_VERSION
  fi
else
  if [ "$OCAML_VERSION" != "$AVAILABLE_OCAML_VERSION" ]; then
    echo Switching to OCaml $OCAML_VERSION
    opam switch $OCAML_VERSION
  fi
fi
echo "eval \`opam config env\`" >> ${ENV}
. ${ENV}

AVAILABLE_OPAM_VERSION=`opam --version 2>/dev/null || true`
AVAILABLE_OCAML_VERSION=`ocamlc -version 2>/dev/null || true`
echo The build environment in ${OBJ} now has:
echo OPAM version $AVAILABLE_OPAM_VERSION
echo OCaml verion $AVAILABLE_OCAML_VERSION
echo To use the new environment, source the file:
echo ${OBJ}/opam-env.sh

if [ "" != "${BUILD}" ]; then
  echo Attempting to build ${BUILD} using a local opam file
  cd ${ORIGINAL_DIR}
  opam pin add -k git ${BUILD} .
  opam install ${BUILD} -y
fi