configure

#!/usr/bin/env bash

set -e
set -x

trap 'echo -e "\n\nConfiguration failed\n\n" >&2' ERR

rootdir=$(readlink -f $(dirname $0))

function usage() {
	echo "'configure' configures UBBD to compile on supported platforms."
	echo ""
	echo "Usage: ./configure [OPTION]..."
	echo ""
	echo "Defaults for the options are specified in brackets."
	echo ""
	echo "General:"
	echo " -h, --help                Display this help and exit"
	echo ""
	echo " --prefix=path             Configure installation prefix (default: /usr/local)"
	echo " --enable-debug            Configure for debug builds"
	echo " --enable-asan             Enable address sanitizer"
	echo ""
	echo "Backend:"
	echo " --enable-rbd-backend                Support RBD backend."
	echo " --disable-rbd-backend             Dont support RBD backend."
	echo " --enable-s3-backend                Support S3 backend."
	echo " --disable-s3-backend             Dont support S3 backend."
	echo " --enable-ssh-backend                Support SSH backend."
	echo " --disablee-ssh-backend           Dont support SSH backend."
	echo " --enable-cache-backend                Support CACHE backend."
	echo " --disable-cache-backend             Dont support CACHE backend."
	echo ""
}

# Load default values
# Convert config to sourceable configuration file
sed -r 's/CONFIG_([[:alnum:]_]+)=(.*)/CONFIG[\1]=\2/g' $rootdir/CONFIG > $rootdir/CONFIG.sh
declare -A CONFIG
source $rootdir/CONFIG.sh
rm $rootdir/CONFIG.sh

CONFIG_RBD_BACKEND=y

CONFIG_S3_BACKEND=n

CONFIG_CACHE_BACKEND=n

CONFIG_SSH_BACKEND=n

for i in "$@"; do
	case "$i" in
		-h | --help)
			usage
			exit 0
			;;
		--prefix=*)
			CONFIG[PREFIX]="${i#*=}"
			;;
		--enable-debug)
			CONFIG[DEBUG]=y
			;;
		--disable-debug)
			CONFIG[DEBUG]=n
			;;
		--enable-asan)
			CONFIG[ASAN]=y
			;;
		--disable-asan)
			CONFIG[ASAN]=n
			;;
		--enable-rbd-backend)
			CONFIG[RBD_BACKEND]=y
			;;
		--disable-rbd-backend)
			CONFIG[RBD_BACKEND]=n
			;;
		--enable-s3-backend)
			CONFIG[S3_BACKEND]=y
			;;
		--disable-s3-backend)
			CONFIG[S3_BACKEND]=n
			;;
		--enable-cache-backend)
			CONFIG[CACHE_BACKEND]=y
			;;
		--disable-cache-backend)
			CONFIG[CACHE_BACKEND]=n
			;;
		--enable-ssh-backend)
			CONFIG[SSH_BACKEND]=y
			;;
		--disable-ssh-backend)
			CONFIG[CACHE_BACKEND]=n
			;;
		*)
			echo "Unrecognized option $i"
			usage
			exit 1
			;;
	esac
done

CC=gcc

if [[ $arch == x86_64* ]]; then
	BUILD_CMD=($CC -o /dev/null -x c $CPPFLAGS $CFLAGS $LDFLAGS "-march=native")
else
	BUILD_CMD=($CC -o /dev/null -x c $CPPFLAGS $CFLAGS $LDFLAGS)
fi
BUILD_CMD+=(-I/usr/local/include -L/usr/local/lib)

if [[ "${CONFIG[RBD]}" = "y" ]]; then
	if ! echo -e '#include <rbd/librbd.h>\n#include <rados/librados.h>\n' \
		'int main(void) { return 0; }\n' \
		| "${BUILD_CMD[@]}" -lrados -lrbd - 2> /dev/null; then
		echo "--enable-rbd-backend requires librados and librbd."
		echo "Please install then re-run this script."
		exit 1
	fi
fi

if [[ "${CONFIG[ASAN]}" = "y" ]]; then
	if ! echo -e 'int main(void) { return 0; }\n' \
		| "${BUILD_CMD[@]}" -fsanitize=address - 2> /dev/null; then
		echo "--enable-asan requires libasan."
		echo "Please install then re-run this script."
		exit 1
	fi
fi

# We are now ready to generate final configuration. But first do sanity
# check to see if all keys in CONFIG array have its reflection in CONFIG file.
if (($(grep -cE "^\s*CONFIG_[[:alnum:]_]+=" "$rootdir/CONFIG") != ${#CONFIG[@]})); then
	echo ""
	echo "BUG: Some configuration options are not present in CONFIG file. Please update this file."
	echo "Missing options in CONFIG (+) file and in current config (-): "
	diff -u --label "CONFIG file" --label "CONFIG[@]" \
		<(sed -r -e '/^[[:space:]]*$/d; /^[[:space:]]*#.*/d; s/(CONFIG_[[:alnum:]_]+)=.*/\1/g' CONFIG | sort) \
		<(printf "CONFIG_%s\n" "${!CONFIG[@]}" | sort)
	exit 1
fi

echo -n "Creating mk/config.mk..."
mkdir -p $rootdir/mk/
cp -f $rootdir/CONFIG $rootdir/mk/config.mk
for key in "${!CONFIG[@]}"; do
	sed -i.bak -r "s#[[:space:]]*CONFIG_${key}=.*#CONFIG_${key}\?=${CONFIG[$key]}#g" $rootdir/mk/config.mk
done

echo "Type 'make' to build."

exit 0