[PATCH v2 1/2] Add nmalloc and nrealloc

[OndÅej BÃlka <neleai at seznam dot cz>]

Hi,

This patches cover more cases than previous patch. As a first part we
define nmalloc macros.

I tried a inline function but gcc decided not to inline some of these.
As this would cause a avoidable division that cost much more than few
bites that not inlining could save I go back to macros.

	* include/nmalloc.h: New file.

---
 include/nmalloc.h | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 include/nmalloc.h

diff --git a/include/nmalloc.h b/include/nmalloc.h
new file mode 100644
index 0000000..48deeaf
--- /dev/null
+++ b/include/nmalloc.h
@@ -0,0 +1,41 @@
+/* malloc macros with overflow checking.
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+
+#include <stdint.h>
+#ifndef _NMALLOC_H
+#define _NMALLOC_H
+
+#define NMALLOC(x, t) ((t *) nmalloc (x, sizeof (t)))
+#define NREALLOC(p, x, t) ((t *) nrealloc (p, x, sizeof (t)))
+
+#define  nmalloc(n, s) \
+({									\
+  size_t __n = (n), __s = (s);						\
+  (__s == 0 || SIZE_MAX / __s < __n) ? NULL : malloc (__n * __s);	\
+})
+
+void *realloc(void *ptr, size_t size);
+
+#define nrealloc(p, n, s) \
+({									\
+  size_t __n = (n), __s = (s);						\
+  (__n != 0 && SIZE_MAX / __s < __n) ? NULL : realloc (p, __n * __s);	\
+})
+
+#endif /* _NMALLOC_H  */
-- 
1.8.4.rc3