#!/usr/bin/env bash

set -e

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

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

function usage()
{
	echo "'configure' configures SPDK 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 " --target-arch=arch        Target build architecture. Must be a valid GNU arch. Default: native"
	echo ""
	echo " --cross-prefix=prefix     Prefix for cross compilation (default: none)"
	echo "                           example: aarch64-linux-gnu"
	echo ""
	echo " --enable-debug            Configure for debug builds"
	echo " --enable-log-bt           Enable support of backtrace printing in SPDK logs (requires libunwind)."
	echo " --enable-werror           Treat compiler warnings as errors"
	echo " --enable-asan             Enable address sanitizer"
	echo " --enable-ubsan            Enable undefined behavior sanitizer"
	echo " --enable-coverage         Enable code coverage tracking"
	echo " --enable-lto              Enable link-time optimization"
	echo " --enable-pgo-capture      Enable generation of profile guided optimization data"
	echo " --enable-pgo-use          Use previously captured profile guided optimization data"
	echo " --disable-tests           Disable building of tests"
	echo ""
	echo "Specifying Dependencies:"
	echo "--with-DEPENDENCY[=path]   Use the given dependency. Optionally, provide the"
	echo "                           path."
	echo "--without-DEPENDENCY       Do not link to the given dependency. This may"
	echo "                           disable features and components."
	echo ""
	echo "Valid dependencies are listed below."
	echo " dpdk                      Build against a custom dpdk version. By default, the dpdk"
	echo "                           submodule in spdk tree will be used."
	echo "                           example: /usr/share/dpdk/x86_64-default-linuxapp-gcc"
	echo " env                       Use an alternate environment implementation instead of DPDK."
	echo "                           Implies --without-dpdk."
	echo " igb-uio-driver            Build DPDK's igb-uio driver."
	echo "                           Required on some systems to use qat devices. This flag is"
	echo "                           effective only with the default dpdk submodule."
	echo "                           No path required"
	echo " crypto                    Build vbdev crypto module."
	echo "                           No path required."
	echo " fio                       Build fio_plugin."
	echo "                           example: /usr/src/fio"
	echo " vhost                     Build vhost target. Enabled by default."
	echo "                           No path required."
	echo " internal-vhost-lib        Use the internal copy of rte_vhost. By default, the upstream"
	echo "                           rte_vhost from DPDK will be used."
	echo "                           No path required."
	echo " virtio                    Build vhost initiator and virtio-pci bdev modules."
	echo "                           No path required."
	echo " pmdk                      Build persistent memory bdev."
	echo "                           example: /usr/share/pmdk"
	echo " reduce                    Build vbdev compression module."
	echo "                           No path required."
	echo " vpp                       Build VPP net module."
	echo "                           example: /vpp_repo/build-root/rpmbuild/vpp-18.01.1.0/build-root/install-vpp-native/vpp"
	echo " rbd                       Build Ceph RBD bdev module."
	echo "                           No path required."
	echo " rdma                      Build RDMA transport for NVMf target and initiator."
	echo "                           No path required."
	echo " fc                        Build FC transport for NVMf target."
	echo "                           If an argument is provided, it is considered a directory containing"
	echo "                           libufc.a and fc_lld.h. Otherwise the regular system paths will"
	echo "                           be searched."
	echo " shared                    Build spdk shared libraries."
	echo "                           No path required."
	echo " iscsi-initiator           Build with iscsi bdev module."
	echo "                           No path required."
	echo " vtune                     Required to profile I/O under Intel VTune Amplifier XE."
	echo "                           example: /opt/intel/vtune_amplifier_xe_version"
	echo " ocf                       Build OCF library and bdev module."
	echo "                           If argument is directory, interpret it as root of OCF repo"
	echo "                           If argument is file, interpret it as compiled OCF lib"
	echo "                           If no argument is specified, OCF git submodule is used by default"
	echo "                           example: /usr/src/ocf/"
	echo " isal                      Build with ISA-L. Enabled by default on x86 and aarch64 architectures."
	echo "                           No path required."
	echo " uring                     Build I/O uring bdev."
	echo "                           If an argument is provided, it is considered a directory containing"
	echo "                           liburing.a and io_uring.h. Otherwise the regular system paths will"
	echo "                           be searched."
	echo " fuse                      Build FUSE components for mounting a blobfs filesystem."
	echo "                           No path required."
	echo " nvme-cuse                 Build NVMe driver with support for CUSE-based character devices."
	echo "                           No path required."
	echo ""
	echo "Environment variables:"
	echo ""
	echo "CC                         C compiler"
	echo "CFLAGS                     C compiler flags"
	echo "CXX                        C++ compiler"
	echo "CXXFLAGS                   C++ compiler flags"
	echo "LD                         Linker"
	echo "LDFLAGS                    Linker flags"
	echo "DESTDIR                    Destination for 'make install'"
	echo ""
}

# Load default values
# Convert config to sourcable 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

function check_dir() {
	arg="$1"
	dir="${arg#*=}"
	if [ ! -d "$dir" ]; then
		echo "$arg: directory not found"
		exit 1
	fi
}

for i in "$@"; do
	case "$i" in
		-h|--help)
			usage
			exit 0
			;;
		--prefix=*)
			CONFIG[PREFIX]="${i#*=}"
			;;
		--target-arch=*)
			CONFIG[ARCH]="${i#*=}"
			;;
		--cross-prefix=*)
			CONFIG[CROSS_PREFIX]="${i#*=}"
			;;
		--enable-debug)
			CONFIG[DEBUG]=y
			;;
		--disable-debug)
			CONFIG[DEBUG]=n
			;;
		--enable-log-bt)
			CONFIG[LOG_BACKTRACE]=y
			;;
		--disable-log-bt)
			CONFIG[LOG_BACKTRACE]=n
			;;
		--enable-asan)
			CONFIG[ASAN]=y
			;;
		--disable-asan)
			CONFIG[ASAN]=n
			;;
		--enable-ubsan)
			CONFIG[UBSAN]=y
			;;
		--disable-ubsan)
			CONFIG[UBSAN]=n
			;;
		--enable-tsan)
			CONFIG[TSAN]=y
			;;
		--disable-tsan)
			CONFIG[TSAN]=n
			;;
		--enable-coverage)
			CONFIG[COVERAGE]=y
			;;
		--disable-coverage)
			CONFIG[COVERAGE]=n
			;;
		--enable-lto)
			CONFIG[LTO]=y
			;;
		--disable-lto)
			CONFIG[LTO]=n
			;;
		--enable-pgo-capture)
			CONFIG[PGO_CAPTURE]=y
			;;
		--disable-pgo-capture)
			CONFIG[PGO_CAPTURE]=n
			;;
		--enable-pgo-use)
			CONFIG[PGO_USE]=y
			;;
		--disable-pgo-use)
			CONFIG[PGO_USE]=n
			;;
		--enable-tests)
			CONFIG[TESTS]=y
			;;
		--disable-tests)
			CONFIG[TESTS]=n
			;;
		--enable-werror)
			CONFIG[WERROR]=y
			;;
		--disable-werror)
			CONFIG[WERROR]=n
			;;
		--with-dpdk=*)
			check_dir "$i"
			CONFIG[DPDK_DIR]=$(readlink -f ${i#*=})
			;;
		--without-dpdk)
			CONFIG[DPDK_DIR]=
			;;
		--with-env=*)
			CONFIG[ENV]="${i#*=}"
			;;
		--with-rbd)
			CONFIG[RBD]=y
			;;
		--without-rbd)
			CONFIG[RBD]=n
			;;
		--with-rdma)
			CONFIG[RDMA]=y
			;;
		--without-rdma)
			CONFIG[RDMA]=n
			;;
		--with-fc=*)
			CONFIG[FC]=y
			CONFIG[FC_PATH]=$(readlink -f ${i#*=})
			;;
		--with-fc)
			CONFIG[FC]=y
			CONFIG[FC_PATH]=
			;;
		--without-fc)
			CONFIG[FC]=n
			CONFIG[FC_PATH]=
			;;
		--with-shared)
			CONFIG[SHARED]=y
			;;
		--without-shared)
			CONFIG[SHARED]=n
			;;
		--with-iscsi-initiator)
			CONFIG[ISCSI_INITIATOR]=y
			;;
		--without-iscsi-initiator)
			CONFIG[ISCSI_INITIATOR]=n
			;;
		--with-crypto)
			CONFIG[CRYPTO]=y
			;;
		--without-crypto)
			CONFIG[CRYPTO]=n
			;;
		--with-vhost)
			CONFIG[VHOST]=y
			;;
		--without-vhost)
			CONFIG[VHOST]=n
			;;
		--with-internal-vhost-lib)
			CONFIG[VHOST_INTERNAL_LIB]=y
			;;
		--without-internal-vhost-lib)
			CONFIG[VHOST_INTERNAL_LIB]=n
			;;
		--with-virtio)
			CONFIG[VIRTIO]=y
			;;
		--without-virtio)
			CONFIG[VIRTIO]=n
			;;
		--with-pmdk)
			CONFIG[PMDK]=y
			CONFIG[PMDK_DIR]=""
			;;
		--with-pmdk=*)
			CONFIG[PMDK]=y
			check_dir "$i"
			CONFIG[PMDK_DIR]=$(readlink -f ${i#*=})
			;;
		--without-pmdk)
			CONFIG[PMDK]=n
			;;
		--with-reduce)
			CONFIG[REDUCE]=y
			;;
		--without-reduce)
			CONFIG[REDUCE]=n
			;;
		--with-vpp)
			CONFIG[VPP]=y
			;;
		--with-vpp=*)
			CONFIG[VPP]=y
			check_dir "$i"
			CONFIG[VPP_DIR]=$(readlink -f ${i#*=})
			;;
		--without-vpp)
			CONFIG[VPP]=n
			;;
		--with-fio=*)
			check_dir "$i"
			CONFIG[FIO_SOURCE_DIR]="${i#*=}"
			CONFIG[FIO_PLUGIN]=y
			;;
		--without-fio)
			CONFIG[FIO_SOURCE_DIR]=
			CONFIG[FIO_PLUGIN]=n
			;;
		--with-vtune=*)
			check_dir "$i"
			CONFIG[VTUNE_DIR]="${i#*=}"
			CONFIG[VTUNE]=y
			;;
		--without-vtune)
			CONFIG[VTUNE_DIR]=
			CONFIG[VTUNE]=n
			;;
		--with-igb-uio-driver)
			CONFIG[IGB_UIO_DRIVER]=y
			;;
		--without-igb-uio-driver)
			CONFIG[IGB_UIO_DRIVER]=n
			;;
		--with-ocf)
			CONFIG[OCF]=y
			CONFIG[OCF_PATH]=$(readlink -f "./ocf")
			;;
		--with-ocf=*)
			CONFIG[OCF]=y
			CONFIG[OCF_PATH]=$(readlink -f ${i#*=})
			;;
		--without-ocf)
			CONFIG[OCF]=n
			CONFIG[OCF_PATH]=
			;;
		--with-isal)
			CONFIG[ISAL]=y
			;;
		--without-isal)
			CONFIG[ISAL]=n
			;;
		--with-uring=*)
			CONFIG[URING]=y
			CONFIG[URING_PATH]=$(readlink -f ${i#*=})
			;;
		--with-uring)
			CONFIG[URING]=y
			CONFIG[URING_PATH]=
			;;
		--without-uring)
			CONFIG[URING]=n
			CONFIG[URING_PATH]=
			;;
		--with-fuse)
			CONFIG[FUSE]=y
			;;
		--without-fuse)
			CONFIG[FUSE]=n
			;;
		--with-nvme-cuse)
			CONFIG[NVME_CUSE]=y
			;;
		--without-nvme-cuse)
			CONFIG[NVME_CUSE]=n
			;;
		--)
			break
			;;
		*)
			echo "Unrecognized option $i"
			usage
			exit 1
	esac
done

# Detect the compiler toolchain
$rootdir/scripts/detect_cc.sh --cc="$CC" --cxx="$CXX" --lto="${CONFIG[LTO]}" --ld="$LD" --cross-prefix="${CONFIG[CROSS_PREFIX]}"  > $rootdir/mk/cc.mk

CC=$(cat $rootdir/mk/cc.mk | grep "DEFAULT_CC=" | cut -d "=" -f 2)
CC_TYPE=$(cat $rootdir/mk/cc.mk | grep "CC_TYPE=" | cut -d "=" -f 2)

arch=$($CC -dumpmachine)

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

# Detect architecture and force no ISA-L if non-x86 or non-aarch64 architecture
if [[ "${CONFIG[ISAL]}" = "y" ]]; then
	if [[ $arch != x86_64* ]] && [[ $arch != aarch64* ]]; then
		echo "Notice: ISA-L disabled due to CPU incompatiblity."
		CONFIG[ISAL]=n
	fi
fi

if [[ "${CONFIG[ISAL]}" = "n" ]] && [[ "${CONFIG[REDUCE]}" = "y" ]]; then
		echo "ERROR Conflicting options: --with-reduce is not compatible with --without-isal."
		exit 1
fi

if [ -z "${CONFIG[ENV]}" ]; then
	CONFIG[ENV]=$rootdir/lib/env_dpdk
	echo "Using default SPDK env in ${CONFIG[ENV]}"
	if [ -z "${CONFIG[DPDK_DIR]}" ]; then
		if [ ! -f "$rootdir"/dpdk/config/common_base ]; then
			echo "DPDK not found; please specify --with-dpdk=<path> or run:"
			echo
			echo "  git submodule update --init"
			exit 1
		else
			CONFIG[DPDK_DIR]="${rootdir}/dpdk/build"
			echo "Using default DPDK in ${CONFIG[DPDK_DIR]}"
		fi

		if [[ "${CONFIG[VHOST]}" = "y" ]] && [[ "${CONFIG[VHOST_INTERNAL_LIB]}" = "n" ]]; then
			# We lookup "common_linux" file to check if DPDK version is >= 19.05.
			# "common_linux" is available since exactly DPDK 19.05 - it was renamed
			# from "common_linuxapp".
			if [ ! -f "$rootdir"/dpdk/config/common_linux ]; then
				echo "Notice: Using internal, legacy rte_vhost library due to DPDK" \
				     "version < 19.05"
				CONFIG[VHOST_INTERNAL_LIB]=y
			fi
		fi
	else
		if [[ "${CONFIG[VHOST]}" = "y" ]] && [[ "${CONFIG[VHOST_INTERNAL_LIB]}" = "n" ]]; then
			# DPDK must be already built, so we can simply try to use the new rte_vhost.
			# It has a number of internal dependencies though, so don't try to link the
			# program, just compile it
			if ! echo -e '#include <rte_vhost.h>\n' \
				'int main(void) { return rte_vhost_extern_callback_register(0, NULL, NULL); }\n' \
				| ${BUILD_CMD[@]} -c -Wno-deprecated-declarations -Werror \
				-I"${CONFIG[DPDK_DIR]}/include" - &>/dev/null; then
				echo "Notice: DPDK's rte_vhost not found or version < 19.05, using internal," \
				     "legacy rte_vhost library."
				CONFIG[VHOST_INTERNAL_LIB]=y
			fi
		fi
	fi
else
	if [ -n "${CONFIG[DPDK_DIR]}" ]; then
		echo "--with-env and --with-dpdk are mutually exclusive."
		exit 1
	fi

	if [ "${CONFIG[VHOST]}" = "y" ]; then
		echo "Vhost is only supported when using the default DPDK environment. Disabling it."
	fi
	# Always disable vhost, but only print the error message if the user explicitly turned it on.
	CONFIG[VHOST]="n"
	if [ "${CONFIG[VIRTIO]}" = "y" ]; then
		echo "Virtio is only supported when using the default DPDK environment. Disabling it."
	fi
	# Always disable virtio, but only print the error message if the user explicitly turned it on.
	CONFIG[VIRTIO]="n"
fi

if [ "${CONFIG[FIO_PLUGIN]}" = "y" ]; then
	if [ -z "${CONFIG[FIO_SOURCE_DIR]}" ]; then
		echo "When fio is enabled, you must specify the fio directory using --with-fio=path"
		exit 1
	fi
else
	CONFIG[FIO_SOURCE_DIR]=
fi

if [ "${CONFIG[VTUNE]}" = "y" ]; then
	if [ -z "${CONFIG[VTUNE_DIR]}" ]; then
		echo "When VTune is enabled, you must specify the VTune directory using --with-vtune=path"
		exit 1
	fi
fi

if [ "${CONFIG[ASAN]}" = "y" -a "${CONFIG[TSAN]}" = "y" ]; then
	echo "ERROR: ASAN and TSAN cannot be enabled at the same time."
	exit 1
fi

if [[ "$OSTYPE" == "freebsd"* ]]; then
	# FreeBSD doesn't support all configurations
	if [[ "${CONFIG[COVERAGE]}" == "y" ]]; then
		echo "ERROR: CONFIG_COVERAGE not available on FreeBSD"
		exit 1
	fi
fi

if [[ "$OSTYPE" == "freebsd"* ]]; then
	if [[ "${CONFIG[VHOST]}" == "y" ]]; then
		echo "Vhost is only supported on Linux. Disabling it."
		CONFIG[VHOST]="n"
	fi
	if [[ "${CONFIG[VHOST_INTERNAL_LIB]}" == "y" ]]; then
		echo "Internal rte_vhost library is only supported on Linux. Disabling it."
		CONFIG[VHOST_INTERNAL_LIB]="n"
	fi
	if [[ "${CONFIG[VIRTIO]}" == "y" ]]; then
		echo "Virtio is only supported on Linux. Disabling it."
		CONFIG[VIRTIO]="n"
	fi
fi

if [ "${CONFIG[RDMA]}" = "y" ]; then
	if ! echo -e '#include <infiniband/verbs.h>\n#include <rdma/rdma_verbs.h>\n' \
		'int main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -libverbs -lrdmacm - 2>/dev/null; then
		echo --with-rdma requires libverbs and librdmacm.
		echo Please install then re-run this script.
		exit 1
	fi

	if echo -e '#include <infiniband/verbs.h>\n' \
		'int main(void) { return !!IBV_WR_SEND_WITH_INV; }\n' \
		| ${BUILD_CMD[@]} -c - 2>/dev/null; then
		CONFIG[RDMA_SEND_WITH_INVAL]="y"
	else
		CONFIG[RDMA_SEND_WITH_INVAL]="n"
		echo "
*******************************************************************************
WARNING: The Infiniband Verbs opcode Send With Invalidate is either not
supported or is not functional with the current version of libibverbs installed
on this system. Please upgrade to at least version 1.1.

Beginning with Linux kernel 4.14, the kernel NVMe-oF initiator leverages Send
With Invalidate RDMA operations to improve performance. Failing to use the
Send With Invalidate operation on the NVMe-oF target side results in full
functionality, but greatly reduced performance. The SPDK NVMe-oF target will
be unable to leverage that operation using the currently installed version
of libibverbs, so Linux kernel NVMe-oF initiators based on kernels greater
than or equal to 4.14 will see significantly reduced performance.
*******************************************************************************"
	fi
fi

if [[ "${CONFIG[FC]}" = "y" ]]; then
	if [[ -n "${CONFIG[FC_PATH]}" ]]; then
		if [ ! -d "${CONFIG[FC_PATH]}" ]; then
			echo "${CONFIG[FC_PATH]}: directory not found"
			exit 1
		fi
	fi
fi

if [[ "${CONFIG[ISAL]}" = "y" ]] || [[ "${CONFIG[CRYPTO]}" = "y" ]]; then
	ver=$(nasm -v | awk '{print $3}' | sed 's/[^0-9]*//g')
	if [[ "${ver:0:1}" -le "2" ]] && [[ "${ver:0:3}" -le "213" ]] && [[ "${ver:0:5}" -lt "21303" ]]; then
		echo "Notice: ISA-L, compression & crypto auto-disabled due to nasm dependency."
		echo "These features require NASM version 2.13.03 or newer.  Please install"
		echo "or upgrade then re-run this script."
		CONFIG[ISAL]=n
		CONFIG[CRYPTO]=n
		CONFIG[IPSEC_MB]=n
		CONFIG[REDUCE]=n
	else
		if [[ "${CONFIG[CRYPTO]}" = "y" ]]; then
			CONFIG[IPSEC_MB]=y
		fi
	fi
fi

if [[ "${CONFIG[ISAL]}" = "y" ]]; then
	if [ ! -f "$rootdir"/isa-l/autogen.sh ]; then
		echo "ISA-L was not found; To install ISA-L run:"
		echo "  git submodule update --init"
		exit 1
	fi

	if [[ "${CONFIG[RBD]}" = "y" ]]; then
		echo "ISAL and RBD cannot co-exist currently so disabling ISAL and compression."
		CONFIG[ISAL]=n
		CONFIG[REDUCE]=n
	else
		cd $rootdir/isa-l
		ISAL_LOG=$rootdir/isa-l/spdk-isal.log
		echo -n "Configuring ISA-L (logfile: $ISAL_LOG)..."
		./autogen.sh &> $ISAL_LOG
		./configure CFLAGS="-fPIC -g -O2" --enable-shared=no >> $ISAL_LOG 2>&1
		echo "done."
		cd $rootdir
	fi
fi

if [[ "${CONFIG[PMDK]}" = "y" ]]; then
	if ! echo -e '#include <libpmemblk.h>\nint main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -lpmemblk - 2>/dev/null; then
		echo --with-pmdk requires libpmemblk.
		echo Please install then re-run this script.
		exit 1
	fi
fi

if [[ "${CONFIG[REDUCE]}" = "y" ]]; then
	if ! echo -e '#include <libpmem.h>\nint main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -lpmem - 2>/dev/null; then
		echo --with-reduce requires libpmem.
		echo Please install then re-run this script.
		exit 1
	fi
fi

if [[ "${CONFIG[VPP]}" = "y" ]]; then
	if [ ! -z "${CONFIG[VPP_DIR]}" ]; then
		VPP_CFLAGS="-L${CONFIG[VPP_DIR]}/lib -I${CONFIG[VPP_DIR]}/include"
	fi
	if ! echo -e '#include <vnet/session/application_interface.h>\nint main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} ${VPP_CFLAGS} -lvppinfra -lsvm -lvlibmemoryclient - 2>/dev/null; then
		echo --with-vpp requires installed vpp.
		echo Please install then re-run this script.
		exit 1
	fi
fi

if [[ "${CONFIG[NVME_CUSE]}" = "y" ]]; then
	if ! echo -e '#define FUSE_USE_VERSION 31\n#include <fuse3/cuse_lowlevel.h>\n#include <fuse3/fuse_lowlevel.h>\n#include <fuse3/fuse_opt.h>\nint main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -lfuse3 -D_FILE_OFFSET_BITS=64 - 2>/dev/null; then
		echo --with-cuse requires libfuse3.
		echo Please install then re-run this script.
		exit 1
	fi
fi

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 --with-rbd requires librados and librbd.
		echo Please install then re-run this script.
		exit 1
	fi
fi

if [[ "${CONFIG[ISCSI_INITIATOR]}" = "y" ]]; then
	# Fedora installs libiscsi to /usr/lib64/iscsi for some reason.
	if ! echo -e '#include <iscsi/iscsi.h>\n#include <iscsi/scsi-lowlevel.h>\n' \
		'#if LIBISCSI_API_VERSION < 20150621\n' \
		'#error\n' \
		'#endif\n' \
		'int main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -L/usr/lib64/iscsi -liscsi - 2>/dev/null; then
		echo --with-iscsi-initiator requires libiscsi with
		echo 'LIBISCSI_API_VERSION >= 20150621.'
		echo Please install then re-run this script.
		exit 1
	fi
fi

if [[ "${CONFIG[LOG_BACKTRACE]}" = "y" ]]; then
	if ! echo -e '#include <libunwind.h>\nint main(void) { return 0; }\n' \
		| ${BUILD_CMD[@]} -lunwind - 2>/dev/null; then
		echo --enable-log-bt requires libunwind.
		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

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

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

if [[ "${CONFIG[OCF]}" = "y" ]]; then
	# If OCF_PATH is a file, assume it is a library and use it to compile with
	if [ -f ${CONFIG[OCF_PATH]} ]; then
		CONFIG[CUSTOMOCF]=y
	else
		CONFIG[CUSTOMOCF]=n
	fi
fi

if [[ "${CONFIG[PGO_CAPTURE]}" = "y" && "${CONFIG[PGO_USE]}" = "y" ]]; then
	echo "ERROR: --enable-pgo-capture and --enable-pgo-use are mutually exclusive."
	exit 1
elif [[ "${CONFIG[PGO_USE]}" = "y" ]]; then
	if [[ "$CC_TYPE" = "clang" ]]; then
		# For clang we need to run an extra step on gathered profiling data.
		echo "Generating suitable profile data"
		llvm-profdata merge -output=build/pgo/default.profdata build/pgo
	fi
fi

if [[ "${CONFIG[URING]}" = "y" ]]; then
	if [[ -n "${CONFIG[URING_PATH]}" ]]; then
		if [ ! -d "${CONFIG[URING_PATH]}" ]; then
			echo "${CONFIG[URING_PATH]}: directory not found"
			exit 1
		fi
	fi
fi

if [[ "${CONFIG[FUSE]}" = "y" ]]; then
	if [[ ! -d /usr/include/fuse3 ]] && [[ ! -d /usr/local/include/fuse3 ]]; then
		echo "--with-fuse requires libfuse3."
		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 [ $(egrep -c "^\s*CONFIG_[[:alnum:]_]+=" $rootdir/CONFIG) -ne ${#CONFIG[@]} ]; then
	echo ""
	echo "BUG: Some configuration options are not present in CONFIG file. Please update this file."
	echo "Missing options in CONFIG (+) file and in current config (-): "
	diff -u --label "CONFIG file" --label "CONFIG[@]" \
		<(sed -r -e '/^\s*$/d; /^\s*#.*/d; s/(CONFIG_[[:alnum:]_]+)=.*/\1/g' CONFIG | sort) \
		<(printf "CONFIG_%s\n" ${!CONFIG[@]} | sort)
	exit 1
fi

echo -n "Creating mk/config.mk..."
cp -f $rootdir/CONFIG $rootdir/mk/config.mk
for key in ${!CONFIG[@]}; do
	sed -i.bak -r "s#^\s*CONFIG_${key}=.*#CONFIG_${key}\?=${CONFIG[$key]}#g" $rootdir/mk/config.mk
done
# On FreeBSD sed -i 'SUFFIX' - SUFFIX is mandatory. So no way but to delete the backed file.
rm -f $rootdir/mk/config.mk.bak
echo "done."

# Environment variables
echo -n "Creating mk/cc.flags.mk..."
rm -f $rootdir/mk/cc.flags.mk
[ -n "$CFLAGS" ] && echo "CFLAGS?=$CFLAGS" > $rootdir/mk/cc.flags.mk
[ -n "$CXXFLAGS" ] && echo "CXXFLAGS?=$CXXFLAGS" >> $rootdir/mk/cc.flags.mk
[ -n "$LDFLAGS" ] && echo "LDFLAGS?=$LDFLAGS" >> $rootdir/mk/cc.flags.mk
[ -n "$DESTDIR" ] && echo "DESTDIR?=$DESTDIR" >> $rootdir/mk/cc.flags.mk
echo "done."

if [[ "$OSTYPE" == "freebsd"* ]]; then
	echo "Type 'gmake' to build."
else
	echo "Type 'make' to build."
fi

exit 0