Don't look for a "safe" memcpy()

C89 says that, if you want to copy overlapping memory blocks, you must use
memmove(), and that attempt to copy overlapping memory blocks using memcpy()
yields undefined behaviour. So we should never even attempt to probe for a
system memcpy() implementation that just happens to handle overlapping
memory blocks. In particular, the compiler might compile the probe program
in such a way that Configure thinks overlapping memcpy() works even when it
doesn't.

This has the additional advantage of removing a Configure probe that needs
to execute a target-platform program on the build host.

1 files changed, 0 insertions, 78 deletions

diff --git a/Configure b/Configure
index 0c50aec492..6739e8babb 100755
--- a/Configure
+++ b/Configure
@@ -747,7 +747,6 @@ d_rint=''
 d_rmdir=''
 d_round=''
 d_safebcpy=''
-d_safemcpy=''
 d_sanemcmp=''
 d_sbrkproto=''
 d_scalbn=''
@@ -17990,82 +17989,6 @@ esac
 set d_safebcpy
 eval $setvar
 
-: can memcpy handle overlapping blocks?
-echo " "
-val="$undef"
-case "$d_memmove" in
-"$define") echo "I'll use memmove() instead of memcpy() for overlapping copies." ;;
-*)	case "$d_memcpy" in
-	"$define")
-		echo "Checking to see if memcpy() can do overlapping copies..." >&4
-		$cat >try.c <<EOCP
-#$i_memory I_MEMORY
-#$i_stdlib I_STDLIB
-#$i_string I_STRING
-#$i_unistd I_UNISTD
-EOCP
-	$cat >>try.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
-		set try
-		if eval $compile_ok; then
-			if $run ./try 2>/dev/null; then
-				echo "Yes, it can."
-				val="$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_try
-	;;
-esac
-set d_safemcpy
-eval $setvar
-
 : can memcmp be trusted to compare relative magnitude?
 val="$undef"
 case "$d_memcmp" in
@@ -25033,7 +24956,6 @@ d_rint='$d_rint'
 d_rmdir='$d_rmdir'
 d_round='$d_round'
 d_safebcpy='$d_safebcpy'
-d_safemcpy='$d_safemcpy'
 d_sanemcmp='$d_sanemcmp'
 d_sbrkproto='$d_sbrkproto'
 d_scalbn='$d_scalbn'