In my LUKS encryption series, I have a discriminated union for storing options for different encryption formats. See qapi/crypto.json in this file:
https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg03187.html You'll notice I have the 'prefix' line for the enum commented out. When I uncomment this, I discovered that the discriminated union visitor does not deal with prefixes. To save having to wade through that big series, here is a quick reproducer diff --git a/qapi-schema.json b/qapi-schema.json index 8d04897..a58648d 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -4083,3 +4083,22 @@ ## { 'enum': 'ReplayMode', 'data': [ 'none', 'record', 'play' ] } + + +{ 'enum': 'QDemoType', + 'prefix': 'QDEMO_TYPE', + 'data': ['foo', 'bar' ] } + +{ 'struct': 'QDemoBase', + 'data': { 'type': 'QDemoType' } } + +{ 'struct': 'QDemoFoo', + 'data': { 'eek': 'int' } } + +{ 'struct': 'QDemoBar', + 'data': { 'wizz': 'str' } } + +{ 'union': 'QDemo', + 'base': 'QDemoBase', + 'discriminator': 'type', + 'data': { 'foo': 'QDemoFoo', 'bar': 'QDemoBar' } } Apply that and then try to build and it'll fail with: qapi-visit.c: In function ‘visit_type_QDemo’: qapi-visit.c:7596:10: error: ‘Q_DEMO_TYPE_FOO’ undeclared (first use in this function) case Q_DEMO_TYPE_FOO: ^ qapi-visit.c:7596:10: note: each undeclared identifier is reported only once for each function it appears in qapi-visit.c:7599:10: error: ‘Q_DEMO_TYPE_BAR’ undeclared (first use in this function) case Q_DEMO_TYPE_BAR: ^ The issue is that we used the 'QDEMO_TYPE' custom prefix for generating the enum, but we didn't use the prefix in the union visitor. I know we had had previous discussions with Markus strongly wanting to kill off the support for enum prefixes. So before I waste time trying to fix this union visitor code to handle prefixes, I figure we should decide if we actually want to fix it, or go with Markus' plan to kill custom prefixes on enums. Per previous discussions, I think the ability to have custom prefixes is quite desirable, to get more natural enum constant names. At the end of the day though, the default enum naming is far from the worst bit of QEMU, so I'm not ultimately too bothered either way. We either make custom enum prefixes work everything they need to, or remove them. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
