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?RCS: $Id$
?RCS:
?RCS: Copyright (c) 1991-1997, 2004-2006, 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 4.0.
?RCS:
?RCS: $Log: d_safemcpy.U,v $
?RCS: Revision 3.0.1.5 1997/02/28 15:41:12 ram
?RCS: patch61: improved overlapping copy check
?RCS: patch61: comfort them if they have memmove
?RCS: patch61: added ?F: metalint hint
?RCS:
?RCS: Revision 3.0.1.4 1995/07/25 13:58:46 ram
?RCS: patch56: re-arranged compile line to include ldflags before objects
?RCS:
?RCS: Revision 3.0.1.3 1995/03/21 08:47:26 ram
?RCS: patch52: swapped two first arguments of memcpy() calls
?RCS:
?RCS: Revision 3.0.1.2 1994/10/29 16:15:10 ram
?RCS: patch36: added 'ldflags' to the test compile line (ADO)
?RCS:
?RCS: Revision 3.0.1.1 1994/05/06 14:53:12 ram
?RCS: patch23: ensure string is not optimized in read-only memory (ADO)
?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 +optimize +ccflags +libs +ldflags rm \
d_memmove i_memory i_stdlib i_string i_unistd 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:.
?F:!safemcpy
?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
$cat >foo.c <<EOCP
#$i_memory I_MEMORY
#$i_stdlib I_STDLIB
#$i_string I_STRING
#$i_unistd I_UNISTD
EOCP
$cat >>foo.c <<'EOCP'
#include <stdio.h>
#ifdef I_MEMORY
# include <memory.h>
#endif
#ifdef I_STDLIB
# include <stdlib.h>
#endif
#ifdef I_STRING
# include <string.h>
#else
# include <strings.h>
#endif
#ifdef I_UNISTD
# include <unistd.h> /* Needed for NetBSD */
#endif
int main()
{
char buf[128], abc[128];
char *b;
int len;
int off;
int align;
/* Copy "abcde..." string to char abc[] so that gcc doesn't
try to store the string in read-only memory. */
memcpy(abc, "abcdefghijklmnopqrstuvwxyz0123456789", 36);
for (align = 7; align >= 0; align--) {
for (len = 36; len; len--) {
b = buf+align;
memcpy(b, abc, len);
for (off = 1; off <= len; off++) {
memcpy(b+off, b, len);
memcpy(b, b+off, len);
if (memcmp(b, abc, len))
exit(1);
}
}
}
exit(0);
}
EOCP
if $cc $optimize $ccflags $ldflags \
-o safemcpy foo.c $libs >/dev/null 2>&1; then
if ./safemcpy 2>/dev/null; then
echo "Yes, it can."
val="$define"
else
echo "It can't, sorry."
case "$d_memmove" in
"$define") echo "But that's Ok since you have memmove()." ;;
esac
fi
else
echo "(I can't compile the test program, so we'll assume not...)"
case "$d_memmove" in
"$define") echo "But that's Ok since you have memmove()." ;;
esac
fi
;;
esac
$rm -f foo.* safemcpy core
set d_safemcpy
eval $setvar
|