1 ?RCS: $Id: d_safemcpy.U,v 3.0.1.5 1997/02/28 15:41:12 ram Exp $
3 ?RCS: Copyright (c) 1991-1993, Raphael Manfredi
5 ?RCS: You may redistribute only under the terms of the Artistic Licence,
6 ?RCS: as specified in the README file that comes with the distribution.
7 ?RCS: You may reuse parts of this distribution only within the terms of
8 ?RCS: that same Artistic Licence; a copy of which may be found at the root
9 ?RCS: of the source tree for dist 3.0.
11 ?RCS: $Log: d_safemcpy.U,v $
12 ?RCS: Revision 3.0.1.5 1997/02/28 15:41:12 ram
13 ?RCS: patch61: improved overlapping copy check
14 ?RCS: patch61: comfort them if they have memmove
15 ?RCS: patch61: added ?F: metalint hint
17 ?RCS: Revision 3.0.1.4 1995/07/25 13:58:46 ram
18 ?RCS: patch56: re-arranged compile line to include ldflags before objects
20 ?RCS: Revision 3.0.1.3 1995/03/21 08:47:26 ram
21 ?RCS: patch52: swapped two first arguments of memcpy() calls
23 ?RCS: Revision 3.0.1.2 1994/10/29 16:15:10 ram
24 ?RCS: patch36: added 'ldflags' to the test compile line (ADO)
26 ?RCS: Revision 3.0.1.1 1994/05/06 14:53:12 ram
27 ?RCS: patch23: ensure string is not optimized in read-only memory (ADO)
29 ?RCS: Revision 3.0 1993/08/18 12:06:58 ram
30 ?RCS: Baseline for dist 3.0 netwide release.
32 ?MAKE:d_safemcpy: Compile cat d_memcpy rm \
33 d_memmove i_memory i_stdlib i_string i_unistd Oldconfig Setvar
34 ?MAKE: -pick add $@ %<
36 ?S: This variable conditionally defines the HAS_SAFE_MEMCPY symbol if
37 ?S: the memcpy() routine can do overlapping copies.
38 ?S: For overlapping copies, memmove() should be used, if available.
40 ?C:HAS_SAFE_MEMCPY (SAFE_MEMCPY):
41 ?C: This symbol, if defined, indicates that the memcpy routine is available
42 ?C: to copy potentially overlapping memory blocks. If you need to
43 ?C: copy overlapping memory blocks, you should check HAS_MEMMOVE and
44 ?C: use memmove() instead, if available.
46 ?H:#$d_safemcpy HAS_SAFE_MEMCPY /**/
50 : can memcpy handle overlapping blocks?
55 "$define") echo "I'll use memmove() instead of memcpy() for overlapping copies." ;;
56 *) case "$d_memcpy" in
58 echo "Checking to see if memcpy() can do overlapping copies..." >&4
79 # include <unistd.h> /* Needed for NetBSD */
83 char buf[128], abc[128];
89 /* Copy "abcde..." string to char abc[] so that gcc doesn't
90 try to store the string in read-only memory. */
91 memcpy(abc, "abcdefghijklmnopqrstuvwxyz0123456789", 36);
93 for (align = 7; align >= 0; align--) {
94 for (len = 36; len; len--) {
97 for (off = 1; off <= len; off++) {
98 memcpy(b+off, b, len);
99 memcpy(b, b+off, len);
100 if (memcmp(b, abc, len))
109 if eval $compile_ok; then
110 if ./try 2>/dev/null; then
114 echo "It can't, sorry."
117 echo "(I can't compile the test program, so we'll assume not...)"
121 $rm -f try.* try core