#!/bin/sh
#
# Copyright © 2009, 2010 Samy Al Bahra.
# Copyright © 2011 Devon H. O'Dell <devon.odell@gmail.com>
# All rights reserved.
#
# 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 AUTHOR 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 AUTHOR 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.
#

REQUIRE_HEADER="stdbool.h stdint.h"
GENERATE_FILE="build/ck.build"

EXIT_SUCCESS=0
EXIT_FAILURE=1

BUILD="$PWD/build/ck.build"
CFLAGS="$CFLAGS -Wall -I../include -pipe"
PREFIX=${PREFIX:-"/usr/local"}
HEADERS=${HEADERS:-"include"}
LIBRARY=${LIBRARY:-"lib"}

export CFLAGS
export PREFIX
LC_ALL=C
export LC_ALL

if test -n "${BASH_VERSION+set}" && (set -o posix) >/dev/null 2>&1; then
 	set -o posix
fi

trap epilog 1 2 3 6

epilog()
{
	rm -f .1.c .1
}

assert()
{

	if test "$#" -eq 2; then
		fail=$2
		print=true
	elif test "$#" -eq 3; then
		fail=$3
		print=echo
	else
		echo "Usage: assert <test> <fail string> or assert <test> <success string> <fail string>" 1>&2
		exit $EXIT_FAILURE
	fi

	if test -z "$1"; then
		echo "failed  [$fail]"
		exit $EXIT_FAILURE
	else
		${print} "success [$1]"
	fi
}

generate()
{
	sed -e "s#@PROFILE@#$PROFILE#g" \
	    -e "s#@CC@#$CC#g"           \
 	    -e "s#@CFLAGS@#$CFLAGS#g"   \
 	    -e "s#@HEADERS@#$HEADERS#g" \
	    -e "s#@LIBRARY@#$LIBRARY#g" \
	    -e "s#@PREFIX@#$PREFIX#g"   \
		$1 > $2
}


for option in $*; do
	value=`echo "$option" | sed -e 's/^[^=]*=\(.*\)/\1/'`

	case "$option" in
	--help)
		echo "./configure"
		echo "  --cflags=N     Compilation flags"
		echo "  --compiler=N   Use compiler \"N\""
		echo "  --headers=N    Headers subdirectory (default is \"${HEADERS}\")"
		echo "  --library=N    Libraries subdirectory (default is \"${LIBRARY}\")"
		echo "  --prefix=N     Installs library files in \"N\""
		echo "  --profile=N    Use build profile \"N\""
		exit $EXIT_SUCCESS
		;;
	--profile=*)
		PROFILE=$value
		;;
	--compiler=*)
		CC=$value
		;;
	--prefix=*)
		PREFIX=$value
		;;
	--cflags=*)
		CFLAGS="$CFLAGS $value"
		;;
	--headers=*)
		HEADERS=$value
		;;
	--library=*)
		LIBRARY=$value
		;;
	*)
		echo "./configure [--help]"
		exit $EXIT_FAILURE
		;;
	esac
done

if test "$PROFILE"; then
	printf "Using user-specified profile....."

	if test ! -f build/ck.build.$PROFILE; then
		echo "failed [$PROFILE]";
		exit $EXIT_FAILURE
	fi

	echo "success [$PROFILE]"
	printf "Generating build files..........."
	generate build/ck.build.in build/ck.build
	generate build/regressions.build.in build/regressions.build
	generate Makefile.in Makefile
	echo "success"
	exit $EXIT_SUCCESS
fi

printf "Detecting operating system......."
SYSTEM=`uname -s 2> /dev/null`
case "$SYSTEM" in
	"SunOS")
		SYSTEM=solaris
		;;
	"Linux"|"uClinux")
		SYSTEM=linux
		;;
	"FreeBSD"|"GNU/kFreeBSD")
		SYSTEM=freebsd
		;;
	"NetBSD")
		SYSTEM=netbsd
		;;
	"OpenBSD")
		SYSTEM=openbsd
		;;
	"DragonFly")
		SYSTEM=dragonflybsd
		;;
	"Darwin")
		SYSTEM=darwin
		;;
	*)
		SYSTEM=
		;;
esac

assert "$SYSTEM" "$SYSTEM" "unsupported"

printf "Detecting machine architecture..."
PLATFORM=`uname -m 2> /dev/null`
case $PLATFORM in
	"macppc"|"Power Macintosh"|"powerpc")
		PLATFORM=ppc32
		ENVIRONMENT=32
		assert "$PLATFORM $ENVIRONMENT" "$PLATFORM $ENVIRONMENT" "unsupported"
		;;
	"sun4u"|"sun4v"|"sparc64")
		PLATFORM=sparcv9
		ENVIRONMENT=64
		;;
	i386|i486|i586|i686|i586_i686|pentium*|athlon*|k5|k6|k6_2|k6_3)
		case $SYSTEM in
			darwin)
				ENVIRONMENT=64
				PLATFORM=x86_64
				;;
			freebsd)
				PLATFORM=x86
				ENVIRONMENT=32

				# FreeBSD doesn't give us a nice way to determine the CPU
				# class of the running system, reporting any 32-bit x86
				# architecture as i386. 486 is its minimum supported CPU
				# class and cmpxchg8b was implemented first in i586.
				dmesg | grep -q "486-class"
				if test "$?" -eq 0; then
					assert "" "" "Must have an i586 class or higher CPU"
				fi

				# FreeBSD still generates code for 486-class CPUs as its
				# default 32-bit target, but we need 586 at the least.
				echo "$CFLAGS" | grep -q 'march='
				if test "$?" -ne 0; then
					# Needed for cmpxchg8b
					CFLAGS="$CFLAGS -march=i586"
				fi
				;;
			linux)
				case $PLATFORM in
					i386|i486)
						assert "" "" "Must have an i586 class or higher CPU"
						;;
				esac

				PLATFORM=x86
				ENVIRONMENT=32
				;;
			
			*)
				PLATFORM=x86
				ENVIRONMENT=32
				assert "$PLATFORM $ENVIRONMENT" "$PLATFORM $ENVIRONMENT" "unsupported"
				;;
		esac
		;;
	"amd64"|"x86_64")
		PLATFORM=x86_64
		ENVIRONMENT=64
		;;
	"i86pc")
		ISA=`isainfo -n 2> /dev/null || echo i386`
		case "$ISA" in
			"amd64")
				PLATFORM=x86_64
				ENVIRONMENT=64
				;;
			*)
				PLATFORM=x86
				ENVIRONMENT=32
				assert "$PLATFORM $ENVIRONMENT" "$PLATFORM $ENVIRONMENT" "unsupported"
				;;
		esac
		;;
	"ppc64")
		PLATFORM=ppc64
		ENVIRONMENT=64
		assert "$PLATFORM $ENVIRONMENT" "$PLATFORM $ENVIRONMENT" "unsupported"
		;;
	*)
		PLATFORM=
		;;
esac

assert "$PLATFORM" "$PLATFORM" "unsupported"

if test "$ENVIRONMENT" -eq 32; then
	CFLAGS="-m32 $CFLAGS"
elif test "$ENVIRONMENT" -eq 64; then
	CFLAGS="-m64 $CFLAGS"
fi

# Platform will be used as a macro.
PROFILE="${PROFILE:-$PLATFORM}"
PLATFORM="__${PLATFORM}__"

printf "Finding suitable compiler........"
CC=`which "${CC:-cc}"`
assert "$CC" "not found"

# Make sure GCC 4.X, the only supported compiler, is being used.
cat << EOF > .1.c
int main(void) {
#if defined(__GNUC__) && (__GNUC__ >= 4)
	return (0);
#else
	return (1);
#endif
}
EOF

$CC -o .1 .1.c
./.1
r=$?
rm -f .1.c .1

if test "$r" -ne 0; then
	assert "" "update compiler"
else
	echo "success [$CC]"
fi

for i in $REQUIRE_HEADER; do
	printf "Checking header file usability..."

	cat << EOF > .1.c
#include <$i>
int main(void){return(0);}
EOF
	$CC -o .1 .1.c 2> /dev/null
	hf_s=$?

	rm -f .1 .1.c
	if test $hf_s -eq 0; then
		echo "success [$i]"
	else
		echo "failed  [$i]"
		exit $EXIT_FAILURE
	fi
done

printf "Generating build files..........."

generate build/ck.build.in build/ck.build
generate build/regressions.build.in build/regressions.build
generate Makefile.in Makefile

echo "success"