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| author | John Snow <jsnow@redhat.com> | 2024-03-15 16:22:43 +0100 |
|---|---|---|
| committer | Markus Armbruster <armbru@redhat.com> | 2024-04-24 10:03:54 +0200 |
| commit | 578cd9329b2c5beac55a8a8c672f96bd40cc183f (patch) | |
| tree | 92043fa86e9758db712cdc3339e10efbf29c42bf | |
| parent | ec103961bf2b8e690d53f8ae98258e9c76caf99a (diff) | |
| download | qemu-578cd9329b2c5beac55a8a8c672f96bd40cc183f.zip qemu-578cd9329b2c5beac55a8a8c672f96bd40cc183f.tar.gz qemu-578cd9329b2c5beac55a8a8c672f96bd40cc183f.tar.bz2 | |
qapi/schema: declare type for QAPISchemaArrayType.element_type
A QAPISchemaArrayType's element type gets resolved only during .check().
We have QAPISchemaArrayType.__init__() initialize self.element_type =
None, and .check() assign the actual type. Using .element_type before
.check() is wrong, and hopefully crashes due to the value being None.
Works.
However, it makes for awkward typing. With .element_type:
Optional[QAPISchemaType], mypy is of course unable to see that it's None
before .check(), and a QAPISchemaType after. To help it over the hump,
we'd have to assert self.element_type is not None before all the (valid)
uses. The assertion catches invalid uses, but only at run time; mypy
can't flag them.
Instead, declare .element_type in .__init__() as QAPISchemaType
*without* initializing it. Using .element_type before .check() now
certainly crashes, which is an improvement. Mypy still can't flag
invalid uses, but that's okay.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-8-armbru@redhat.com>
| -rw-r--r-- | scripts/qapi/schema.py | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py index 307f8af..48f157f 100644 --- a/scripts/qapi/schema.py +++ b/scripts/qapi/schema.py @@ -381,7 +381,7 @@ class QAPISchemaArrayType(QAPISchemaType): super().__init__(name, info, None) assert isinstance(element_type, str) self._element_type_name = element_type - self.element_type = None + self.element_type: QAPISchemaType def need_has_if_optional(self): # When FOO is an array, we still need has_FOO to distinguish |