path: root/backends/msmouse.c
diff options
authorEric Blake <eblake@redhat.com>2016-03-17 16:48:37 -0600
committerMarkus Armbruster <armbru@redhat.com>2016-03-18 10:29:26 +0100
commit32bafa8fdd098d52fbf1102d5a5e48d29398c0aa (patch)
treeca10fdb98f8c5c7cbecee273e64691c2c8f17728 /backends/msmouse.c
parent861877a0dd0a8e1bdbcc9743530f4dc9745a736a (diff)
qapi: Don't special-case simple union wrappers
Simple unions were carrying a special case that hid their 'data' QMP member from the resulting C struct, via the hack method QAPISchemaObjectTypeVariant.simple_union_type(). But by using the work we started by unboxing flat union and alternate branches, coupled with the ability to visit the members of an implicit type, we can now expose the simple union's implicit type in qapi-types.h: | struct q_obj_ImageInfoSpecificQCow2_wrapper { | ImageInfoSpecificQCow2 *data; | }; | | struct q_obj_ImageInfoSpecificVmdk_wrapper { | ImageInfoSpecificVmdk *data; | }; ... | struct ImageInfoSpecific { | ImageInfoSpecificKind type; | union { /* union tag is @type */ | void *data; |- ImageInfoSpecificQCow2 *qcow2; |- ImageInfoSpecificVmdk *vmdk; |+ q_obj_ImageInfoSpecificQCow2_wrapper qcow2; |+ q_obj_ImageInfoSpecificVmdk_wrapper vmdk; | } u; | }; Doing this removes asymmetry between QAPI's QMP side and its C side (both sides now expose 'data'), and means that the treatment of a simple union as sugar for a flat union is now equivalent in both languages (previously the two approaches used a different layer of dereferencing, where the simple union could be converted to a flat union with equivalent C layout but different {} on the wire, or to an equivalent QMP wire form but with different C representation). Using the implicit type also lets us get rid of the simple_union_type() hack. Of course, now all clients of simple unions have to adjust from using su->u.member to using su->u.member.data; while this touches a number of files in the tree, some earlier cleanup patches helped minimize the change to the initialization of a temporary variable rather than every single member access. The generated qapi-visit.c code is also affected by the layout change: |@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member | } | switch (obj->type) { | case IMAGE_INFO_SPECIFIC_KIND_QCOW2: |- visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err); |+ visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err); | break; | case IMAGE_INFO_SPECIFIC_KIND_VMDK: |- visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err); |+ visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err); | break; | default: | abort(); Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
Diffstat (limited to 'backends/msmouse.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/backends/msmouse.c b/backends/msmouse.c
index 5e1833c6e6..8dea5a130f 100644
--- a/backends/msmouse.c
+++ b/backends/msmouse.c
@@ -68,7 +68,7 @@ static CharDriverState *qemu_chr_open_msmouse(const char *id,
ChardevReturn *ret,
Error **errp)
- ChardevCommon *common = backend->u.msmouse;
+ ChardevCommon *common = backend->u.msmouse.data;
CharDriverState *chr;
chr = qemu_chr_alloc(common, errp);