[Qemu-devel] [PATCH v4 01/10] qapi: Assert in places where variants are not handled

[Eric Blake <eblake@redhat.com>]

We are getting closer to the point where we could use one union
as the base or variant type within another union type (as long
as there are no collisions between any possible combination of
member names allowed across all discriminator choices).  But
until we get to that point, it is worth asserting that variants
are not present in places where we are not prepared to handle
them: base types must still be plain structs, and anywhere we
explode a struct into a parameter list (events and command
marshalling), we don't support variants in that explosion.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v4: new patch, split out from .is_empty() patch
---
 scripts/qapi.py          | 1 +
 scripts/qapi-commands.py | 3 ++-
 scripts/qapi-event.py    | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 6b2aa6e..dc26ef9 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -960,6 +960,7 @@ class QAPISchemaObjectType(QAPISchemaType):
             assert isinstance(self.base, QAPISchemaObjectType)
             self.base.check(schema)
             self.base.check_clash(schema, self.info, seen)
+            assert not self.base.variants
         for m in self.local_members:
             m.check(schema)
             m.check_clash(self.info, seen)
diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index f44e01f..edcbd10 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -2,7 +2,7 @@
 # QAPI command marshaller generator
 #
 # Copyright IBM, Corp. 2011
-# Copyright (C) 2014-2015 Red Hat, Inc.
+# Copyright (C) 2014-2016 Red Hat, Inc.
 #
 # Authors:
 #  Anthony Liguori <aliguori@us.ibm.com>
@@ -30,6 +30,7 @@ def gen_call(name, arg_type, ret_type):

     argstr = ''
     if arg_type:
+        assert not arg_type.variants
         for memb in arg_type.members:
             if memb.optional:
                 argstr += 'has_%s, ' % c_name(memb.name)
diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py
index fb579dd..c03cb78 100644
--- a/scripts/qapi-event.py
+++ b/scripts/qapi-event.py
@@ -59,6 +59,7 @@ def gen_event_send(name, arg_type):
                  name=name)

     if arg_type and arg_type.members:
+        assert not arg_type.variants
         ret += mcgen('''
     qov = qmp_output_visitor_new();
     v = qmp_output_get_visitor(qov);
-- 
2.5.0