build: detect overflow for [re]allocate_array.

Use reallocarray() when we have it (i.e. in OpenBSD system). When we
don't, use equivalent overflow detection for our allocate_array and
reallocate_array functions.

Remove lib/reallocarray.c from our LIBOBJS as we no longer need it.

Provide a fallback SIZE_MAX macro definition in flexint.h (not
preprocessor friendly, but enough for our reallocate_array use case).

1 files changed, 0 insertions, 49 deletions

diff --git a/lib/reallocarray.c b/lib/reallocarray.c
deleted file mode 100644
index 0c1e250..0000000
--- a/lib/reallocarray.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook 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.
- */
-
-/* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */
-
-#include <config.h>
-#ifndef HAVE_REALLOCARRAY
-#undef reallocarray
-
-#include <sys/types.h>
-#include <errno.h>
-#ifdef HAVE_STDINT_H
-#include <stdint.h>
-#endif
-#include <stdlib.h>
-
-void *reallocarray(void *, size_t, size_t);
-
-/*
- * 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);
-}
-#endif /* HAVE_REALLOCARRAY */