diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2017-01-18 22:07:34 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2017-02-01 03:37:17 +0200 |
| commit | ed63ec0d22ccdce3b2222d9a514423b7fbba3a0d (patch) | |
| tree | e8c361e656f9e039332374484dd1f8607317a219 | |
| parent | d757573e69f2ef58a4a7b41f6c55d65fa1e1c5c2 (diff) | |
ARRAY_SIZE: check that argument is an array
It's a familiar pattern: some code uses ARRAY_SIZE, then refactoring
changes the argument from an array to a pointer to a dynamically
allocated buffer. Code keeps compiling but any ARRAY_SIZE calls now
return the size of the pointer divided by element size.
Let's add build time checks to ARRAY_SIZE before we allow more
of these in the code-base.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
| -rw-r--r-- | include/qemu/osdep.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 689f253ea7..56c9e22405 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -198,8 +198,15 @@ extern int daemon(int, int); #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) #endif +/* + * &(x)[0] is always a pointer - if it's same type as x then the argument is a + * pointer, not an array. + */ +#define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ + typeof(&(x)[0]))) #ifndef ARRAY_SIZE -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ + QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) #endif int qemu_daemon(int nochdir, int noclose); |