qxl: switch to constants within BUILD_BUG_ON
commitdf45892c1290c6c853010b83e5afebe8740cb9fa
authorMichael S. Tsirkin <mst@redhat.com>
Wed, 25 Jan 2017 21:48:51 +0000 (25 23:48 +0200)
committerMichael S. Tsirkin <mst@redhat.com>
Tue, 31 Jan 2017 13:57:27 +0000 (31 15:57 +0200)
treebc3eff9b9091a4eef523bc48757d6565e373a3ba
parentf29831828441318c7916ae28e6e16e4a1c4a6795
qxl: switch to constants within BUILD_BUG_ON

We are switching BUILD_BUG_ON to verify that it's parameter is a
compile-time constant, and it turns out that some gcc versions
(specifically gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609) are
not smart enough to figure it out for expressions involving local
variables. This is harmless but means that the check is ineffective for
these platforms.  To fix, replace variables with macros.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
hw/display/qxl.c