[PATCH] qcow2: Silence clang -m32 compiler warning

[Hanna Reitz <hreitz@redhat.com>]

With -m32, size_t is generally only a uint32_t.  That makes clang
complain that in the assertion

  assert(qiov->size <= INT64_MAX);

the range of the type of qiov->size (size_t) is too small for any of its
values to ever exceed INT64_MAX.

Cast qiov->size to uint64_t to silence clang.

Fixes: f7ef38dd1310d7d9db76d0aa16899cbc5744f36d
       ("block: use int64_t instead of uint64_t in driver read
       handlers")
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
---
I don't know whether this is the best possible solution, or whether we
should care about this at all (I personally think it's basically just
wrong for clang to warn about always-true conditions in assertions), but
I thought I might as well just send this patch as the basis for a
discussion.
---
 block/qcow2-cluster.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 5727f92dcb..21884a1ab9 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -513,7 +513,8 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
      */
     assert(src_cluster_offset <= INT64_MAX);
     assert(src_cluster_offset + offset_in_cluster <= INT64_MAX);
-    assert(qiov->size <= INT64_MAX);
+    /* Cast qiov->size to uint64_t to silence a compiler warning on -m32 */
+    assert((uint64_t)qiov->size <= INT64_MAX);
     bdrv_check_qiov_request(src_cluster_offset + offset_in_cluster, qiov->size,
                             qiov, 0, &error_abort);
     /*
-- 
2.31.1