[05/17] qapi: Avoid use of 'data' member of qapi unions

Commit Message

Eric Blake Feb. 20, 2016, 12:19 a.m. UTC

qapi code generators currently create a 'void *data' member as
part of the anonymous union embedded in the C struct corresponding
to a qapi union.  However, directly assigning to this member of
the union feels a bit fishy, when we can directly use the rest
of the struct instead.

Signed-off-by: Eric Blake <[e-mail]>

---
v1: no change
Previously posted as part of qapi cleanup series F:
v6: rebase to latest
---
 blockdev.c | 31 +++++++++++++++++--------------
 ui/input.c |  2 +-
 2 files changed, 18 insertions(+), 15 deletions(-)

Comments

Daniel P. Berrangé Feb. 22, 2016, 10:34 a.m. UTC | #1

On Fri, Feb 19, 2016 at 05:19:35PM -0700, Eric Blake wrote:
> qapi code generators currently create a 'void *data' member as
> part of the anonymous union embedded in the C struct corresponding
> to a qapi union.  However, directly assigning to this member of
> the union feels a bit fishy, when we can directly use the rest
> of the struct instead.
> 
> Signed-off-by: Eric Blake <[e-mail]>
> 
> ---
> v1: no change
> Previously posted as part of qapi cleanup series F:
> v6: rebase to latest
> ---
>  blockdev.c | 31 +++++++++++++++++--------------
>  ui/input.c |  2 +-
>  2 files changed, 18 insertions(+), 15 deletions(-)

Reviewed-by: Daniel P. Berrange <[e-mail]>


Regards,
Daniel

Patch

diff --git a/blockdev.c b/blockdev.c
index 1f73478..09b9586 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1204,15 +1204,11 @@  void hmp_commit(Monitor *mon, const QDict *qdict)
     }
 }

-static void blockdev_do_action(TransactionActionKind type, void *data,
-                               Error **errp)
+static void blockdev_do_action(TransactionAction *action, Error **errp)
 {
-    TransactionAction action;
     TransactionActionList list;

-    action.type = type;
-    action.u.data = data;
-    list.value = &action;
+    list.value = action;
     list.next = NULL;
     qmp_transaction(&list, false, NULL, errp);
 }
@@ -1238,8 +1234,11 @@  void qmp_blockdev_snapshot_sync(bool has_device, const char *device,
         .has_mode = has_mode,
         .mode = mode,
     };
-    blockdev_do_action(TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
-                       &snapshot, errp);
+    TransactionAction action = {
+        .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
+        .u.blockdev_snapshot_sync = &snapshot,
+    };
+    blockdev_do_action(&action, errp);
 }

 void qmp_blockdev_snapshot(const char *node, const char *overlay,
@@ -1249,9 +1248,11 @@  void qmp_blockdev_snapshot(const char *node, const char *overlay,
         .node = (char *) node,
         .overlay = (char *) overlay
     };
-
-    blockdev_do_action(TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
-                       &snapshot_data, errp);
+    TransactionAction action = {
+        .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
+        .u.blockdev_snapshot = &snapshot_data,
+    };
+    blockdev_do_action(&action, errp);
 }

 void qmp_blockdev_snapshot_internal_sync(const char *device,
@@ -1262,9 +1263,11 @@  void qmp_blockdev_snapshot_internal_sync(const char *device,
         .device = (char *) device,
         .name = (char *) name
     };
-
-    blockdev_do_action(TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
-                       &snapshot, errp);
+    TransactionAction action = {
+        .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
+        .u.blockdev_snapshot_internal_sync = &snapshot,
+    };
+    blockdev_do_action(&action, errp);
 }

 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
diff --git a/ui/input.c b/ui/input.c
index e15c618..1e81c25 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -472,7 +472,7 @@  InputEvent *qemu_input_event_new_move(InputEventKind kind,
     InputMoveEvent *move = g_new0(InputMoveEvent, 1);

     evt->type = kind;
-    evt->u.data = move;
+    evt->u.rel = move; /* also would work as evt->u.abs */
     move->axis = axis;
     move->value = value;
     return evt;