configure

#!/bin/bash

# Copyright 2018-2019 Maarten de Vries <maarten@de-vri.es>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

PROJECT_ROOT="$(cd "$(dirname "$0")"; pwd)"

die() {
	local pattern="$1"
	shift
	printf "$pattern\n" "$@" >&2
	exit 1
}

short_usage() {
	echo "usage: ./configure [--help] [PARAM=value ...]"
}

usage() {
	short_usage
	echo
	echo "Command-line options:"
	echo "  --help -h          Show this help message."
	echo
	echo "Parameters:"
	echo "  PREFIX=/usr/local     Set the installation prefix."
	echo "  LIBDIR=lib            Set the installation path for libraries."
	echo "  BINDIR=bin            Set the installation path for binaries."
	echo "  DATADIR=share         Set the installation path for data files."
	echo "  RELY_ON_SEARCH=false  Rely on the system search path for finding the preload library."
	echo
	echo "If LIBDIR, BINDIR or DATADIR are given as relative path, they are interpreted relative to PREFIX."
	echo
	echo "If RELY_ON_SEARCH is set to true, the preload library will be added to LD_PRELOAD"
	echo "as \"libcurl_inject_opt.so\" without absolute path. The dynamic linker will have"
	echo "to find the library on it's own. This allows the preload library to be used even"
	echo "with binaries that have elevated privileges on some systems (such as Linux)."

}

parse_single_config() {
	local source="$1"
	local arg="$2"
	if ! [[ $arg =~ ([_a-zA-Z0-9]+)\ *=\ *(.*) ]]; then
		short_usage >&2
		die "\nunrecognized argument: %s" "$arg"
	fi

	name="${BASH_REMATCH[1]}"
	value="${BASH_REMATCH[2]}"
	case "$name" in
		PREFIX)  PREFIX="$value";;
		LIBDIR)  LIBDIR="$value";;
		BINDIR)  BINDIR="$value";;
		DATADIR) DATADIR="$value";;
		RELY_ON_SEARCH) RELY_ON_SEARCH="$value";;
		*)
			short_usage >&2
			die "\nunrecognized parameter in %s: %s" "$source" "$name";;
	esac
}

parse_config() {
	while read arg; do
		parse_single_config "cache" "$arg"
	done
}

parse_args() {
	for arg in "$@"; do
		if [[ $arg == "--help" || $arg == "-h" ]]; then
			usage
			exit 0
		fi
		parse_single_config "command line" "$arg"
	done
}

generate_config() {
cat <<EOF
PREFIX  = $PREFIX
LIBDIR  = $LIBDIR
BINDIR  = $BINDIR
DATADIR = $DATADIR
RELY_ON_SEARCH = $RELY_ON_SEARCH
EOF
}

generate_make_config() {
cat <<EOF
PROJECT_ROOT = $PROJECT_ROOT
BUILD_DIR    = $PWD
EOF
}

PREFIX="/usr/local"
LIBDIR="lib"
BINDIR="bin"
DATADIR="share"
RELY_ON_SEARCH="false"

[[ -f config.cache ]] && parse_config < config.cache
parse_args "$@"

printf "PREFIX:  %s\n" "$PREFIX"
printf "LIBDIR:  %s\n" "$LIBDIR"
printf "BINDIR:  %s\n" "$BINDIR"
printf "DATADIR: %s\n" "$DATADIR"
printf "RELY_ON_SEARCH: %s\n" "$RELY_ON_SEARCH"

echo "Generating config.cache"
generate_config > config.cache

if [[ $PWD != $PROJECT_ROOT ]]; then
	echo "Generating config.make"
	generate_make_config > config.make
	echo "Copying Makefile"
	cp "$PROJECT_ROOT/Makefile" Makefile
fi