#!/bin/sh -
#
# @(#)$Id: mkconfig,v 1.2 2018/09/28 05:49:13 jneitzel Exp $
#
# Write out an appropriate "config.h" file.
# This script is invoked automatically from the Makefile.
# Thus, the user does not need to run it manually.
#
# Exit w/ a status of 0 on success.
# Exit w/ a status of 1 on error.
# --
# Jeffrey Allen Neitzel
#

CONFIG_H="config.h"
rm -f $CONFIG_H
trap 'status=$? ; rm -f $CONFIG_H ; exit $status' HUP INT QUIT TERM

UNAME_S="`uname -s`"
UNAME_SRM="`uname -srm`"
PROGNAME="`basename $0`"
if test $# -ne 0 ; then echo 'usage: $(SHELL) ./'"$PROGNAME" >&2 ; exit 1 ; fi
if test X"$UNAME_S" = X -o X"$UNAME_SRM" = X ; then
	echo "$PROGNAME: Fatal uname(1) error" >&2 ; exit 1
fi

#
# Check whether or not we have the arc4random_uniform() function.
#
checkHaveArc4randomUniform()
{
rm -f arc4randomu.c arc4randomu
cat <<EOI >arc4randomu.c
#include <stdlib.h>
int main(void) { (void)arc4random_uniform(0200); return 0; }
EOI
cc -std=c99 -pedantic -Wall -Wextra -o arc4randomu arc4randomu.c >/dev/null 2>&1
test $? -eq 0 && ./arc4randomu
test $? -eq 0 &&
	echo '#define	HAVE_ARC4RANDOM_UNIFORM	1' ||
		echo '#define	HAVE_ARC4RANDOM_UNIFORM	0'
rm -f arc4randomu.c arc4randomu
}

cat <<EOI >$CONFIG_H
/*
 * rasgen - a random ASCII string generator
 */
/*
 * _XOPEN_SOURCE and/or _DEFAULT_SOURCE should be defined only if needed
 * to avoid compilation errors or warnings for the rasgen program on a
 * given system.  The systems where these feature test macros are (known
 * to be) needed are defined in the mkconfig script.
 *
 * This includes only Linux and (?maybe?) SunOS (Solaris/OpenIndiana)
 * at the present time.
 *
 *	Configured for: $UNAME_SRM
 */

#ifndef	CONFIG_H
#define	CONFIG_H

`checkHaveArc4randomUniform`

EOI

case "$UNAME_S" in
*BSD|Darwin|DragonFly)
	echo "/* $UNAME_S: No need for _XOPEN_SOURCE or _DEFAULT_SOURCE */" \
		>>$CONFIG_H
	;;
Linux)
	echo '#define	_XOPEN_SOURCE	700'   >>$CONFIG_H
	echo '#define	_DEFAULT_SOURCE'       >>$CONFIG_H
	;;
SunOS)
	( echo '#define	CONFIG_SUNOS' ; echo ) >>$CONFIG_H
	echo '#define	_XOPEN_SOURCE	700'   >>$CONFIG_H
	;;
*)
	#
	# This may or may not cause a compilation error.
	# Simply try it to see if it works or not.
	#
	echo "$PROGNAME: WARNING: Check \"$CONFIG_H\" if compilation fails." >&2
	cat <<EOI >>$CONFIG_H
/*
 * WARNING: $UNAME_SRM: Unknown system
 *
 * Please report this result to the developer if possible.
 */
EOI
	;;
esac

echo                             >>$CONFIG_H
echo '#endif	/* !CONFIG_H */' >>$CONFIG_H