diff mbox

[2/8] add QEMU_BUILD_BUG_EXPR

Message ID 20161027153217.16984-3-dgilbert@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dr. David Alan Gilbert Oct. 27, 2016, 3:32 p.m. UTC 
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Glib's GLIB_STATIC_ASSERT_EXPR can't be used in an array initialisation
where as this rune can.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 include/qemu/compiler.h | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Juan Quintela Feb. 13, 2017, 12:02 p.m. UTC | #1 
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> Glib's GLIB_STATIC_ASSERT_EXPR can't be used in an array initialisation
> where as this rune can.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>
diff mbox

Patch

diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 157698b..b6ad32c 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -88,6 +88,11 @@ 
 #define QEMU_BUILD_BUG_ON(x) \
     typedef char glue(qemu_build_bug_on__,__LINE__)[(x)?-1:1] __attribute__((unused));
 
+/* Evaluates to 0 or fails; seems to work in an array initialisation unlike
+ * GLIB_STATIC_ASSERT_EXPR.  Fails on true.
+ */
+#define QEMU_BUILD_BUG_EXPR(x) (sizeof(int [(x)?-1:1])-sizeof(int [1]))
+
 #if defined __GNUC__
 # if !QEMU_GNUC_PREREQ(4, 4)
    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */