configure

#!/bin/sh

prefix=/usr/local
OUR_CPPFLAGS=

# Get a temporary filename
i=0
set -C
while : ; do i=$(($i+1))
tmpc="./conf$$-$PPID-$i.c"
2>|/dev/null > "$tmpc" && break
test "$i" -gt 50 && fail "$0: cannot create temporary file $tmpc"
done
set +C
trap 'rm "$tmpc"' EXIT INT QUIT TERM HUP

ismac() {
	uname -s | grep Darwin >/dev/null
}

isx86_64() {
	uname -m | grep -i X86_64 >/dev/null
}

isbsd() {
	uname -s | grep BSD >/dev/null
}

isopenbsd() {
	uname -s | grep OpenBSD >/dev/null
}

check_compile() {
	printf "checking %s ... " "$1"
	printf "$3" > "$tmpc"
	local res=0
	$CC $OUR_CPPFLAGS $CPPFLAGS $2 $CFLAGS -c "$tmpc" -o /dev/null >/dev/null 2>&1 \
	|| res=1
	test x$res = x0 && \
	{ printf "yes\n" ; test x"$2" = x || OUR_CPPFLAGS="$OUR_CPPFLAGS $2" ; } \
	|| printf "no\n"
	return $res
}

check_define() {
	printf "checking whether \$CC defines %s ... " "$1"
	local res=1
	$CC $OUR_CPPFLAGS $CPPFLAGS $CFLAGS -dM -E - </dev/null | grep "$1" >/dev/null && res=0
	test x$res = x0 && printf "yes\n" || printf "no\n"
	return $res
}

check_compile_run() {
	printf "checking %s ... " "$1"
	printf "$2" > "$tmpc"
	local res=0
	$CC $OUR_CPPFLAGS $CPPFLAGS $CFLAGS "$tmpc" -o "$tmpc".out >/dev/null 2>&1 \
	|| res=1
	test x$res = x0 && { "$tmpc".out || res=1 ; }
	rm -f "$tmpc".out
	test x$res = x0 && printf "yes\n" || printf "no\n"
	return $res
}

usage() {
	echo "supported arguments"
	echo "--prefix=/path            default: $prefix"
	echo "--exec_prefix=/path       default: $prefix/bin"
	echo "--bindir=/path            default: $prefix/bin"
	echo "--libdir=/path            default: $prefix/lib"
	echo "--includedir=/path        default: $prefix/include"
	echo "--sysconfdir=/path        default: $prefix/etc"
	echo "--ignore-cve              default: no"
	echo "	if set to yes ignores CVE-2015-3887 and makes it possible"
	echo "	to preload from current dir (insecure)"
	ismac && isx86_64 && echo "--fat-binary : build for both i386 and x86_64 architectures on 64-bit Macs"
	echo "--help : show this text"
	exit 1
}

spliteq() {
	arg=$1
	echo "${arg#*=}"
	#alternatives echo "$arg" | cut -d= -f2-
	# or echo "$arg" | sed 's/[^=]*=//'
}

fat_binary=
ignore_cve=no
parsearg() {
	case "$1" in
	--prefix=*) prefix=`spliteq $1`;;
	--exec_prefix=*) exec_prefix=`spliteq $1`;;
	--bindir=*) bindir=`spliteq $1`;;
	--libdir=*) libdir=`spliteq $1`;;
	--includedir=*) includedir=`spliteq $1`;;
	--sysconfdir=*) sysconfdir=`spliteq $1`;;
	--ignore-cve) ignore_cve=1;;
	--ignore-cve=*) ignore_cve=`spliteq $1`;;
	--fat-binary) fat_binary=1;;
	--help) usage;;
	esac
}

while true ; do
	case $1 in
	-*) parsearg "$1"; shift;;
	*) break ;;
	esac
done

if [ -z "$exec_prefix" ] ; then
	exec_prefix=$prefix
fi

if [ -z "$libdir" ] ; then
	libdir=$prefix/lib
fi

if [ -z "$includedir" ] ; then
	includedir=$prefix/include
fi

if [ -z "$sysconfdir" ] ; then
	sysconfdir=$prefix/etc
fi

if [ -z "$bindir" ] ; then
	bindir=$exec_prefix/bin
fi

if [ -z "$CC" ] ; then
	CC=cc
fi

check_compile 'whether netinet/in.h defines s6_addr16' "" \
'#include <netinet/in.h>\nint main(int a, char**c){struct in6_addr x={.s6_addr32[0]=a};return x.s6_addr16[0]; }' \
|| {
check_compile 'whether netinet/in.h defines __u6_addr.__u6_addr16' \
'-Ds6_addr16=__u6_addr.__u6_addr16 -Ds6_addr32=__u6_addr.__u6_addr32' \
'#include <netinet/in.h>\nint main(int a, char**c){struct in6_addr x={.s6_addr32[0]=a};return x.s6_addr16[0]; }'
}

check_define __OpenBSD__ && \
check_compile_run 'whether OpenBSDs fclose() (illegally) calls close()' \
'#include <stdio.h>\n#include<stdlib.h>\nint close(int x){exit(0);}int main(){fclose(stdin);return 1;}' && \
OUR_CPPFLAGS="$OUR_CPPFLAGS -DBROKEN_FCLOSE"

echo "CC=$CC">config.mak
[ -z "$CPPFLAGS" ] || echo "CPPFLAGS=$CPPFLAGS">>config.mak
[ -z "$CFLAGS" ] || echo "USER_CFLAGS=$CFLAGS">>config.mak
[ -z "$LDFLAGS" ] || echo "USER_LDFLAGS=$LDFLAGS">>config.mak
echo prefix=$prefix>>config.mak
echo exec_prefix=$exec_prefix>>config.mak
echo bindir=$bindir>>config.mak
echo libdir=$libdir>>config.mak
echo includedir=$includedir>>config.mak
echo sysconfdir=$sysconfdir>>config.mak
[ "$ignore_cve" = "no" ] && echo "CPPFLAGS+= -DSUPER_SECURE">>config.mak
[ -z "$OUR_CPPFLAGS" ] || echo "CPPFLAGS+= $OUR_CPPFLAGS" >>config.mak
make_cmd=make
if ismac ; then
	echo NO_AS_NEEDED=>>config.mak
	echo LDSO_SUFFIX=dylib>>config.mak
	echo MAC_CFLAGS+=-DIS_MAC=1>>config.mak
	if isx86_64 && [ "$fat_binary" = 1 ] ; then
		echo "Configuring a fat binary for i386 and x86_64"
		echo MAC_CFLAGS+=-arch i386 -arch x86_64>>config.mak
		echo LDFLAGS+=-arch i386 -arch x86_64>>config.mak
	fi
	echo LD_SET_SONAME=-Wl,-install_name,>>config.mak
elif isbsd ; then
	echo LIBDL=>>config.mak
	echo "CFLAGS+=-DIS_BSD">>config.mak
	isopenbsd && echo "CFLAGS+=-DIS_OPENBSD">>config.mak
	make_cmd=gmake
fi

echo "Done, now run $make_cmd && $make_cmd install"