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author | Daniel P. Berrange <berrange@redhat.com> | 2013-09-09 09:59:45 +0100 |
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committer | Daniel P. Berrange <berrange@redhat.com> | 2013-09-09 16:42:01 +0100 |
commit | de0c5b13f7f2058f90dfd6425b3d337f137759fd (patch) | |
tree | 79da992d68f6f61a60f9845e19064bfa0ddc626d | |
parent | 7b7d750f87a7111e2e405f5de578e6bbaed7e1a9 (diff) | |
download | libvirt-python-split-de0c5b13f7f2058f90dfd6425b3d337f137759fd.tar.gz libvirt-python-split-de0c5b13f7f2058f90dfd6425b3d337f137759fd.tar.xz libvirt-python-split-de0c5b13f7f2058f90dfd6425b3d337f137759fd.zip |
Import gnulib's xalloc_oversized macro
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
-rw-r--r-- | libvirt-override.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/libvirt-override.c b/libvirt-override.c index 246a15b..acd06a6 100644 --- a/libvirt-override.c +++ b/libvirt-override.c @@ -20,6 +20,7 @@ #include <Python.h> #include <libvirt/libvirt.h> #include <libvirt/virterror.h> +#include <stddef.h> #include "typewrappers.h" #include "build/libvirt.h" @@ -35,6 +36,21 @@ extern void initcygvirtmod(void); # define MIN(a,b) (((a) < (b)) ? (a) : (b)) #endif +/* Return 1 if an array of N objects, each of size S, cannot exist due + to size arithmetic overflow. S must be positive and N must be + nonnegative. This is a macro, not a function, so that it + works correctly even when SIZE_MAX < N. + + By gnulib convention, SIZE_MAX represents overflow in size + calculations, so the conservative dividend to use here is + SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value. + However, malloc (SIZE_MAX) fails on all known hosts where + sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for + exactly-SIZE_MAX allocations on such hosts; this avoids a test and + branch when S is known to be 1. */ +#define xalloc_oversized(n, s) \ + ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n)) + #if 0 # define DEBUG_ERROR 1 #endif |