Re: [PATCH v4 38/46] qapi/introspect.py: add _gen_features helper

[Eduardo Habkost]

On Wed, Sep 30, 2020 at 12:31:42AM -0400, John Snow wrote:
> _make_tree might receive a dict or some other type. Adding features
> information should arguably be performed by the caller at such a time
> when we know the type of the object and don't have to re-interrogate it.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  scripts/qapi/introspect.py | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
> index f7de3953391..5cbdc7414bd 100644
> --- a/scripts/qapi/introspect.py
> +++ b/scripts/qapi/introspect.py
> @@ -52,16 +52,12 @@
>  
>  
>  def _make_tree(obj: Union[_DObject, str], ifcond: List[str],
> -               features: List[QAPISchemaFeature],
>                 extra: Optional[Extra] = None
>                 ) -> Union[TreeNode, AnnotatedNode]:
>      if extra is None:
>          extra = {}
>      if ifcond:
>          extra['if'] = ifcond
> -    if features:
> -        assert isinstance(obj, dict)
> -        obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]

Now the reason for moving this code outside _make_tree() is more
obvious due to the type annotations.

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

>      if extra:
>          return (obj, extra)
>      return obj
> @@ -197,6 +193,11 @@ def _use_type(self, typ: QAPISchemaType) -> str:
>              return '[' + self._use_type(typ.element_type) + ']'
>          return self._name(typ.name)
>  
> +    @classmethod
> +    def _gen_features(cls,
> +                      features: List[QAPISchemaFeature]) -> List[TreeNode]:
> +        return [_make_tree(f.name, f.ifcond) for f in features]
> +
>      def _gen_tree(self, name: str, mtype: str, obj: _DObject,
>                    ifcond: List[str],
>                    features: Optional[List[QAPISchemaFeature]]) -> None:
> @@ -209,7 +210,9 @@ def _gen_tree(self, name: str, mtype: str, obj: _DObject,
>              name = self._name(name)
>          obj['name'] = name
>          obj['meta-type'] = mtype
> -        self._trees.append(_make_tree(obj, ifcond, features, extra))
> +        if features:
> +            obj['features'] = self._gen_features(features)
> +        self._trees.append(_make_tree(obj, ifcond, extra))
>  
>      def _gen_member(self,
>                      member: QAPISchemaObjectTypeMember) -> TreeNode:
> @@ -219,7 +222,9 @@ def _gen_member(self,
>          }
>          if member.optional:
>              obj['default'] = None
> -        return _make_tree(obj, member.ifcond, member.features)
> +        if member.features:
> +            obj['features'] = self._gen_features(member.features)
> +        return _make_tree(obj, member.ifcond)
>  
>      def _gen_variants(self, tag_name: str,
>                        variants: List[QAPISchemaVariant]) -> _DObject:
> @@ -231,7 +236,7 @@ def _gen_variant(self, variant: QAPISchemaVariant) -> 
> TreeNode:
>              'case': variant.name,
>              'type': self._use_type(variant.type)
>          }
> -        return _make_tree(obj, variant.ifcond, None)
> +        return _make_tree(obj, variant.ifcond)
>  
>      def visit_builtin_type(self, name: str, info: Optional[QAPISourceInfo],
>                             json_type: str) -> None:
> -- 
> 2.26.2
> 

-- 
Eduardo