[PATCH v2] qapi: provide a friendly string representation of QAPI classes

["Daniel P. Berrangé" <berrange@redhat.com>]

If printing a QAPI schema object for debugging we get the classname and
a hex value for the instance:

  <qapi.schema.QAPISchemaEnumType object at 0x7f0ab4c2dad0>
  <qapi.schema.QAPISchemaObjectType object at 0x7f0ab4c2dd90>
  <qapi.schema.QAPISchemaArrayType object at 0x7f0ab4c2df90>

With this change we instead get the classname and the human friendly
name of the QAPI type instance:

  <QAPISchemaEnumType:CpuS390State>
  <QAPISchemaObjectType:CpuInfoS390>
  <QAPISchemaArrayType:CpuInfoFastList>

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---

v1 was two & half years ago:

  https://mail.gnu.org/archive/html/qemu-devel/2021-03/msg01645.html

 scripts/qapi/schema.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 231ebf61ba..20ffacbdf0 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -73,6 +73,12 @@ def __init__(self, name: str, info, doc, ifcond=None, features=None):
         self.features = features or []
         self._checked = False
 
+    def __repr__(self):
+        if self.name is not None:
+            return "<%s:%s>" % (type(self).__name__, self.name)
+        else:
+            return "<%s>" % type(self).__name__
+
     def c_name(self):
         return c_name(self.name)
 
-- 
2.41.0