[Qemu-devel] [PATCH v10 25/30] qapi: Hoist tag collision check to Variants.check()

[Eric Blake]

Checking that a given QAPISchemaObjectTypeVariant.name is a
member of the corresponding QAPISchemaEnumType of the owning
QAPISchemaObjectTypeVariants.tag_member ensures that there are
no collisions in the generated C union for those tag values
(since the enum itself should have no collisions).

However, this check was the only thing that Variant.check() was
doing beyond the work of the superclass ObjectTypeMember.check(),
and resulted in a difference of the .check() signatures just to
pass the enum type down.

Simplify things by instead doing the tag name check as part of
Variants.check(), at which point we can rely on inheritance
instead of overriding Variant.check().

Signed-off-by: Eric Blake <address@hidden>

---
v10: new patch
---
 scripts/qapi.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 6d8c4c7..798df51 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -1056,9 +1056,11 @@ class QAPISchemaObjectTypeVariants(object):
     def check(self, schema, seen):
         if self.tag_name:    # flat union
             self.tag_member = seen[self.tag_name]
-        assert isinstance(self.tag_member.type, QAPISchemaEnumType)
+        tag_type = self.tag_member.type
+        assert isinstance(tag_type, QAPISchemaEnumType)
         for v in self.variants:
-            v.check(schema, self.tag_member.type)
+            v.check(schema)
+            assert v.name in tag_type.values

     def check_clash(self, schema, seen):
         for v in self.variants:
@@ -1071,10 +1073,6 @@ class 
QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
     def __init__(self, name, typ):
         QAPISchemaObjectTypeMember.__init__(self, name, typ, False)

-    def check(self, schema, tag_type):
-        QAPISchemaObjectTypeMember.check(self, schema)
-        assert self.name in tag_type.values
-
     # This function exists to support ugly simple union special cases
     # TODO get rid of them, and drop the function
     def simple_union_type(self):
-- 
2.4.3