add compat for reallocarray

compat/reallocarray.c

@@ -0,0 +1,40 @@
+/*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
+/*
+ * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "../config.h"
+
+#include <sys/types.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
+ * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
+ */
+#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
+
+void *
+reallocarray(void *optr, size_t nmemb, size_t size)
+{
+	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+	    nmemb > 0 && SIZE_MAX / nmemb < size) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	return realloc(optr, size * nmemb);
+}

configure

@@ -227,6 +227,7 @@ runtest openssl		OPENSSL		|| true
 runtest pr_set_name	PR_SET_NAME	|| true
 runtest program_invocation_short_name PROGRAM_INVOCATION_SHORT_NAME "" -D_GNU_SOURCE || true
 runtest queue_h		QUEUE_H		|| true
+runtest reallocarray	REALLOCARRAY	|| true
 runtest recallocarray	RECALLOCARRAY	|| true
 runtest setproctitle	SETPROCTITLE	|| true
 runtest strlcat		STRLCAT		|| true
@@ -298,6 +299,7 @@ cat <<__HEREDOC__
 #define HAVE_PROGRAM_INVOCATION_SHORT_NAME ${HAVE_PROGRAM_INVOCATION_SHORT_NAME}
 #define HAVE_PR_SET_NAME	${HAVE_PR_SET_NAME}
 #define HAVE_QUEUE_H		${HAVE_QUEUE_H}
+#define HAVE_REALLOCARRAY	${HAVE_REALLOCARRAY}
 #define HAVE_RECALLOCARRAY	${HAVE_RECALLOCARRAY}
 #define HAVE_SETPROCTITLE	${HAVE_SETPROCTITLE}
 #define HAVE_STRLCAT		${HAVE_STRLCAT}
@@ -309,6 +311,7 @@ __HEREDOC__
 
 [ ${HAVE_EXPLICIT_BZERO} -eq 0 -o \
   ${HAVE_FREEZERO} -eq 0 -o \
+  ${HAVE_REALLOCARRAY} -eq 0 -o \
   ${HAVE_RECALLOCARRAY} -eq 0 -o \
   ${HAVE_STRLCAT} -eq 0 -o \
   ${HAVE_STRLCPY} -eq 0 -o \
@@ -346,8 +349,12 @@ fi
 if [ ${HAVE_IMSG} -eq 0 ]; then
 	COMPAT="${COMPAT} compat/imsg.o compat/imsg-buffer.o"
 fi
+if [ ${HAVE_REALLOCARRAY} -eq 0 ]; then
+	echo "extern	void	*reallocarray(void*, size_t, size_t);"
+	COMPAT="${COMPAT} compat/reallocarray.o"
+fi
 if [ ${HAVE_RECALLOCARRAY} -eq 0 ]; then
-	echo "extern	void*	 recallocarray(void*, size_t, size_t, size_t);"
+	echo "extern	void	*recallocarray(void*, size_t, size_t, size_t);"
 	COMPAT="${COMPAT} compat/recallocarray.o"
 fi
 if [ ${HAVE_SETPROCTITLE} -eq 0 ]; then

have/reallocarray.c

@@ -0,0 +1,7 @@
+#include <stdlib.h>
+
+int
+main(void)
+{
+	return !reallocarray(NULL, 2, 2);
+}