?RCS: $Id: d_safemcpy.U,v 3.0 1993/08/18 12:06:58 ram Exp $
?RCS:
?RCS: Copyright (c) 1991-1993, Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic Licence,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic Licence; a copy of which may be found at the root
?RCS: of the source tree for dist 3.0.
?RCS:
?RCS: $Log: d_safemcpy.U,v $
?RCS: 
?RCS: Copy "abcde..." string to char abc[] so that
?RCS: gcc doesn't try to store the string in read-only memory.
?RCS: 
?RCS: Revision 3.0  1993/08/18  12:06:58  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?MAKE:d_safemcpy: cat d_memcpy +cc +ccflags +libs rm Oldconfig Setvar
?MAKE:	-pick add $@ %<
?S:d_safemcpy:
?S:	This variable conditionally defines the HAS_SAFE_MEMCPY symbol if
?S:	the memcpy() routine can do overlapping copies.
?S:.
?C:HAS_SAFE_MEMCPY (SAFE_MEMCPY):
?C:	This symbol, if defined, indicates that the memcpy routine is available
?C:	to copy potentially overlapping memory blocks. Otherwise you should
?C:	probably use memmove() or memcpy(). If neither is defined, roll your
?C:	own version.
?C:.
?H:#$d_safemcpy HAS_SAFE_MEMCPY	/**/
?H:.
?LINT: set d_safemcpy
: can memcpy handle overlapping blocks?
?X: assume the worst
val="$undef"
case "$d_memcpy" in
"$define")
	echo " "
	echo "Checking to see if your memcpy() can do overlapping copies..." >&4
	$cat >foo.c <<'EOCP'
main()
{
char buf[128], abc[128];
char *b;
int len;
int off;
int align;

memcpy(abc, "abcdefghijklmnopqrstuvwxyz0123456789", 36);

for (align = 7; align >= 0; align--) {
	for (len = 36; len; len--) {
		b = buf+align;
		memcpy(abc, b, len);
		for (off = 1; off <= len; off++) {
			memcpy(b, b+off, len);
			memcpy(b+off, b, len);
			if (memcmp(b, abc, len))
				exit(1);
		}
	}
}
exit(0);
}
EOCP
	if $cc foo.c -o safemcpy $ccflags $libs >/dev/null 2>&1 ; then
		if ./safemcpy 2>/dev/null; then
			echo "Yes, it can."
			val="$define"
		else
			echo "It can't, sorry."
		fi
	else
		echo "(I can't compile the test program, so we'll assume not...)"
	fi
	;;
esac
$rm -f foo.* safemcpy core
set d_safemcpy
eval $setvar