From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1FA6CC54E67 for ; Thu, 14 Mar 2024 13:02:35 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rkkiR-0001nW-5A; Thu, 14 Mar 2024 09:01:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rkkiO-0001n3-S0 for qemu-devel@nongnu.org; Thu, 14 Mar 2024 09:01:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rkkiN-0000yx-AZ for qemu-devel@nongnu.org; Thu, 14 Mar 2024 09:01:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710421302; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ihHHX+SsJD7fMFpa+NdYPb6SFpAYyGO6q3Qsml+esWs=; b=CXdsh7gREmkDZjHEKkkRghOicFynsKwH7gpIpPpi9uV061H9H/8PbrpUswu0yGB2znnHRA i4nOOgON9XX3/wVMnN6IJAK4u/9OcU9ohb2g2t65K2Bwko068R/5/sVKW0Ao8apOUGccwn gICDwGIto+d5W/7DH/ShRGr+MiF6iE0= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-464-f-LjpZgSMSKPCVS8BMoABA-1; Thu, 14 Mar 2024 09:01:38 -0400 X-MC-Unique: f-LjpZgSMSKPCVS8BMoABA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 814A22932486; Thu, 14 Mar 2024 13:01:38 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.138]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 52C81C01854; Thu, 14 Mar 2024 13:01:38 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 3EF0821E6A24; Thu, 14 Mar 2024 14:01:37 +0100 (CET) From: Markus Armbruster To: John Snow Cc: qemu-devel@nongnu.org, Peter Maydell , Michael Roth , Markus Armbruster Subject: Re: [PATCH v4 16/23] qapi/schema: Don't initialize "members" with `None` In-Reply-To: <20240313044127.49089-17-jsnow@redhat.com> (John Snow's message of "Wed, 13 Mar 2024 00:41:20 -0400") References: <20240313044127.49089-1-jsnow@redhat.com> <20240313044127.49089-17-jsnow@redhat.com> Date: Thu, 14 Mar 2024 14:01:37 +0100 Message-ID: <87a5n19dce.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.987, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org John Snow writes: > Declare, but don't initialize the "members" field with type > List[QAPISchemaObjectTypeMember]. > > This simplifies the typing from what would otherwise be > Optional[List[T]] to merely List[T]. This removes the need to add > assertions to several callsites that this value is not None - which it > never will be after the delayed initialization in check() anyway. > > The type declaration without initialization trick will cause accidental > uses of this field prior to full initialization to raise an > AttributeError. > > (Note that it is valid to have an empty members list, see the internal > q_empty object as an example. For this reason, we cannot use the empty > list as a replacement test for full initialization and instead rely on > the _checked/_check_complete fields.) > > Signed-off-by: John Snow > --- > scripts/qapi/schema.py | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py > index 50ebc4f12de..fb30314741a 100644 > --- a/scripts/qapi/schema.py > +++ b/scripts/qapi/schema.py > @@ -20,7 +20,7 @@ > from collections import OrderedDict > import os > import re > -from typing import List, Optional > +from typing import List, Optional, cast > > from .common import ( > POINTER_SUFFIX, > @@ -449,7 +449,7 @@ def __init__(self, name, info, doc, ifcond, features, > self.base = None > self.local_members = local_members > self.variants = variants > - self.members = None > + self.members: List[QAPISchemaObjectTypeMember] > self._check_complete = False > > def check(self, schema): > @@ -482,7 +482,11 @@ def check(self, schema): > for m in self.local_members: > m.check(schema) > m.check_clash(self.info, seen) > - members = seen.values() > + > + # check_clash works in terms of the supertype, but local_members > + # is asserted to be List[QAPISchemaObjectTypeMember]. Do you mean "but self.members is declared as List[QAPISchemaObjectTypeMember]"? > + # Cast down to the subtype. > + members = cast(List[QAPISchemaObjectTypeMember], list(seen.values())) Let's break the line after the comma. > > if self.variants: > self.variants.check(schema, seen) > @@ -515,11 +519,9 @@ def is_implicit(self): > return self.name.startswith('q_') > > def is_empty(self): > - assert self.members is not None > return not self.members and not self.variants > > def has_conditional_members(self): > - assert self.members is not None > return any(m.ifcond.is_present() for m in self.members) > > def c_name(self):