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 X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D60CCC433DB for ; Thu, 14 Jan 2021 00:31:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3E12423343 for ; Thu, 14 Jan 2021 00:31:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E12423343 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55168 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzqXV-000766-4b for qemu-devel@archiver.kernel.org; Wed, 13 Jan 2021 19:31:01 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42272) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzqWY-0006CK-Lc for qemu-devel@nongnu.org; Wed, 13 Jan 2021 19:30:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:39783) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kzqWT-0000dN-Fy for qemu-devel@nongnu.org; Wed, 13 Jan 2021 19:30:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610584195; 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=95HtpX3H9WfiM00KTg1ry8k0JvjY70E/rPe6UTONDMQ=; b=ZQ+YIBOlGNPIZeaY3hxdvKBIbVXIb0SEX9ksbAzV1JMDuXshJjBocwhruUhMzXB2u/YKi7 3LhFQKsQteC+Yq/RmyKU5mUKVkzNQIkJz3oq/Pd4YOjEWamd1/n3h2B9TVj8hUZmOV1+ko 3ATFYJUFRUzwUXKduS7PkjqPxuClYL8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-107-kGhOTlTCPDW5RcurG3m-sQ-1; Wed, 13 Jan 2021 19:29:50 -0500 X-MC-Unique: kGhOTlTCPDW5RcurG3m-sQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 74316107ACF7; Thu, 14 Jan 2021 00:29:49 +0000 (UTC) Received: from localhost (ovpn-66-3.rdu2.redhat.com [10.10.66.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id 96FB510013C1; Thu, 14 Jan 2021 00:29:45 +0000 (UTC) Date: Wed, 13 Jan 2021 19:29:44 -0500 From: Eduardo Habkost To: John Snow Subject: Re: [PATCH v2 07/12] qapi/schema: make QAPISourceInfo mandatory Message-ID: <20210114002944.GI4161@habkost.net> References: <20201217015927.197287-1-jsnow@redhat.com> <20201217015927.197287-8-jsnow@redhat.com> <87ft34x1bv.fsf@dusky.pond.sub.org> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.25, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michael Roth , Cleber Rosa , Markus Armbruster , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jan 13, 2021 at 06:04:29PM -0500, John Snow wrote: > On 1/13/21 11:12 AM, Markus Armbruster wrote: > > John Snow writes: > > > > > Signed-off-by: John Snow > > > > > > --- > > > > > > The event_enum_members change might become irrelevant after a > > > forthcoming (?) patch by Markus, but didn't have it in-hand at time of > > > publishing. > > > > It's in my "[PATCH 00/11] Drop support for QAPIGen without a file name", > > which includes parts of your v1. The parts that are new should be > > injected into your series so they replace your "[PATCH v2 09/12] > > qapi/gen: move write method to QAPIGenC, make fname a str". Holler if > > you need help. > > > > > Signed-off-by: John Snow > > > --- > > > scripts/qapi/events.py | 2 +- > > > scripts/qapi/schema.py | 25 ++++++++++++++----------- > > > scripts/qapi/types.py | 9 +++++---- > > > scripts/qapi/visit.py | 6 +++--- > > > 4 files changed, 23 insertions(+), 19 deletions(-) > > > > > > diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py > > > index 9851653b9d1..9ba4f109028 100644 > > > --- a/scripts/qapi/events.py > > > +++ b/scripts/qapi/events.py > > > @@ -225,7 +225,7 @@ def visit_event(self, > > > self._event_emit_name)) > > > # Note: we generate the enum member regardless of @ifcond, to > > > # keep the enumeration usable in target-independent code. > > > - self._event_enum_members.append(QAPISchemaEnumMember(name, None)) > > > + self._event_enum_members.append(QAPISchemaEnumMember(name, info)) > > > > This "enum" is not supposed to be erroneous. If it is, it's a bug. > > > > Your patch changes how the code behaves should such a bug bite here. > > Before, we crash. Afterwards, we report the bug using @info, which I'd > > expect to produce utterly confusing error messages. > > > > It doesn't change the behavior *here*, though. It changes it whenever this > info object is used in another context. ... and who knows when or where or > why it is being used, or by whom. > > I'll have to play with this. I'm not sure there's any way to coax a bug to > happen here that I am aware of right away. Can you think of how to will one > into existence? > > > My comments on PATCH 06 apply: how the code should behave here is a > > design issue that should be kept out of this patch series. > > > > If you need to pass a value other than None to help with static typing, > > then pass a suitable poison info that will crash right where None > > crashes now. I don't understand what would be the point of inventing something that behaves exactly like None but makes type checking less useful. With None/Optional, mypy gives us a way to be 100% sure the object isn't going to invalid. With a poison value, mypy can't tell us anymore if the code risks crashing at runtime. > > > > I think we need to, yes; or we probably really, really want to. Making the > info parameter optional really adds a lot of unidiomatic type-checking > confetti when we go to use info, and in many more contexts than just this > sorta-built-in-enum; it will creep badly. Which methods would require unidiomatic type-checking because of None/Optional? > > So, I gotta pass ...something here. but what? You want poison, but I think > it's not right to fundamentally poison all built-ins. > > Mmmmmmm. Maybe per-instance poison can be done? We actually share info > objects, but I can make poisoned copies. Using next_line() as a basis: > > def poison(self: T) -> T: > info = copy.copy(self) > info.poisoned = True > return info > > probably almost anything I do is not going to make a lot of sense unless I > can actually replicate and test the different error scenarios to prove that > we didn't make the error spaghetti unknowably worse. I see it as > functionally inevitable that I have to audit this and make sure we get good > error messages anyway, so ... maybe I just ought to do that now anyway. > > > > def gen_events(schema: QAPISchema, > > > diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py > > > index 720449feee4..0449771dfe5 100644 > > > --- a/scripts/qapi/schema.py > > > +++ b/scripts/qapi/schema.py > > > @@ -23,6 +23,7 @@ > > > from .error import QAPIError, QAPISemError > > > from .expr import check_exprs > > > from .parser import QAPISchemaParser > > > +from .source import QAPISourceInfo > > > class QAPISchemaEntity: > > > @@ -36,10 +37,10 @@ def __init__(self, name, info, doc, ifcond=None, features=None): > > > self.name = name > > > self._module = None > > > # For explicitly defined entities, info points to the (explicit) > > > - # definition. For builtins (and their arrays), info is None. > > > - # For implicitly defined entities, info points to a place that > > > - # triggered the implicit definition (there may be more than one > > > - # such place). > > > + # definition. For built-in types (and their arrays), info is a > > > + # special object that evaluates to False. For implicitly defined > > > + # entities, info points to a place that triggered the implicit > > > + # definition (there may be more than one such place). > > > self.info = info > > > self.doc = doc > > > self._ifcond = ifcond or [] > > > @@ -68,7 +69,7 @@ def check_doc(self): > > > def _set_module(self, schema, info): > > > assert self._checked > > > - self._module = schema.module_by_fname(info and info.fname) > > > + self._module = schema.module_by_fname(info.fname if info else None) > > > > Looks unrelated. > > > > Hmm, it sorta is. I have apparently edited this patch since I sent it, but > there was some tomfoolery over how "x and y" statements behave and this edit > was necessary at the time. > > "info and info.fname" returned None when info could actually be None, but > when it was updated to be a special source object, we could accidentally > pass that special source object as the name -- instead of None. Not good. > > I think I re-ordered some patches such that I can just pass in "info.fname" > unconditionally instead as of this patch. > > > > self._module.add_entity(self) > > > def set_module(self, schema): > > [...] > > > -- Eduardo