[PATCH v5 18/36] qapi: establish mypy type-checking baseline

[John Snow]

Fix two very minor issues, and then establish a mypy type-checking
baseline.

Like pylint, this should be run from the folder above:

 > mypy --config-file=qapi/mypy.ini qapi/

This is designed and tested for mypy 0.770 or greater.

Signed-off-by: John Snow <jsnow@redhat.com>
Tested-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
---
 scripts/qapi/mypy.ini  | 60 ++++++++++++++++++++++++++++++++++++++++++
 scripts/qapi/schema.py |  3 ++-
 2 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 scripts/qapi/mypy.ini

diff --git a/scripts/qapi/mypy.ini b/scripts/qapi/mypy.ini
new file mode 100644
index 00000000000..00fac15dc6e
--- /dev/null
+++ b/scripts/qapi/mypy.ini
@@ -0,0 +1,60 @@
+[mypy]
+strict = True
+strict_optional = False
+disallow_untyped_calls = False
+python_version = 3.6
+
+[mypy-qapi.commands]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.error]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.events]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.expr]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.gen]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.introspect]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.parser]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.schema]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.source]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.types]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+
+[mypy-qapi.visit]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 74c6b96d391..483b4b68dff 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -17,6 +17,7 @@
 from collections import OrderedDict
 import os
 import re
+from typing import Optional
 
 from .common import POINTER_SUFFIX, c_name
 from .error import QAPIError, QAPISemError
@@ -25,7 +26,7 @@
 
 
 class QAPISchemaEntity:
-    meta = None
+    meta: Optional[str] = None
 
     def __init__(self, name, info, doc, ifcond=None, features=None):
         assert name is None or isinstance(name, str)
-- 
2.26.2