qapi: add QAPISchemaIfCond.is_present()

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210804083105.97531-4-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

2 files changed, 7 insertions, 4 deletions

diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index db1ebbf53a..e23725e2f9 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -123,10 +123,10 @@ def _tree_to_qlit(obj: JSONValue,
         ret = ''
         if obj.comment:
             ret += indent(level) + f"/* {obj.comment} */\n"
-        if obj.ifcond.ifcond:
+        if obj.ifcond.is_present():
             ret += gen_if(obj.ifcond.ifcond)
         ret += _tree_to_qlit(obj.value, level)
-        if obj.ifcond.ifcond:
+        if obj.ifcond.is_present():
             ret += '\n' + gen_endif(obj.ifcond.ifcond)
         return ret
 
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index e3beb24500..86fcd6cbd5 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -29,6 +29,9 @@ class QAPISchemaIfCond:
     def __init__(self, ifcond=None):
         self.ifcond = ifcond or []
 
+    def is_present(self):
+        return bool(self.ifcond)
+
 
 class QAPISchemaEntity:
     meta: Optional[str] = None
@@ -598,7 +601,7 @@ class QAPISchemaVariants:
                     self.info,
                     "discriminator member '%s' of %s must not be optional"
                     % (self._tag_name, base))
-            if self.tag_member.ifcond.ifcond:
+            if self.tag_member.ifcond.is_present():
                 raise QAPISemError(
                     self.info,
                     "discriminator member '%s' of %s must not be conditional"
@@ -606,7 +609,7 @@ class QAPISchemaVariants:
         else:                   # simple union
             assert isinstance(self.tag_member.type, QAPISchemaEnumType)
             assert not self.tag_member.optional
-            assert self.tag_member.ifcond.ifcond == []
+            assert not self.tag_member.ifcond.is_present()
         if self._tag_name:    # flat union
             # branches that are not explicitly covered get an empty type
             cases = {v.name for v in self.variants}