Re: [PATCH] qapi: Fix code generation with Python 3.5

[John Snow <jsnow@redhat.com>]

On 1/16/20 3:25 PM, Markus Armbruster wrote:
> Recent commit 3e7fb5811b "qapi: Fix code generation for empty modules"
> modules" switched QAPISchema.visit() from
> 
>     for entity in self._entity_list:
> 
> effectively to
> 
>     for mod in self._module_dict.values():
>         for entity in mod._entity_list:
> 
> Visits in the same order as long as .values() is in insertion order.
> That's the case only for Python 3.6 and later.  Before, it's in some
> arbitrary order, which results in broken generated code.
> 
> Fix by making self._module_dict an OrderedDict rather than a dict.
> 
> Fixes: 3e7fb5811baab213dcc7149c3aa69442d683c26c
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  scripts/qapi/schema.py | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index 0bfc5256fb..5100110fa2 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -795,7 +795,7 @@ class QAPISchema(object):
>          self.docs = parser.docs
>          self._entity_list = []
>          self._entity_dict = {}
> -        self._module_dict = {}
> +        self._module_dict = OrderedDict()
>          self._schema_dir = os.path.dirname(fname)
>          self._make_module(None) # built-ins
>          self._make_module(fname)
> 

This problem has bitten me *many* times. I'm wondering if there's a
prescription that isn't just "Wait until we can stipulate 3.6+".