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 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 20398C433DB for ; Tue, 9 Feb 2021 12:58:38 +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 8EDD164E75 for ; Tue, 9 Feb 2021 12:58:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8EDD164E75 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]:36502 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9SbE-0004bA-FE for qemu-devel@archiver.kernel.org; Tue, 09 Feb 2021 07:58:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56290) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9Sa7-0003iv-Ku for qemu-devel@nongnu.org; Tue, 09 Feb 2021 07:57:27 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:40222) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9Sa2-0006mB-Kp for qemu-devel@nongnu.org; Tue, 09 Feb 2021 07:57:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612875439; 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=l14VMiB6c/BjemUCRxmVCpDKN09KPp4ACDu5DXvfjIw=; b=PUwLZDVOivJn1V5QIcdtLzGesXZgV7W0FRZzy5qF8Mr+OVH3RZpUU88P6tIXsUjHHsJ7Xk 5uWevZHU/rGqXz0O/8a9V9O6/ifNLFUy/M4SEdH3jY0JDa1Ee9I5c3CyTT/32syFgyLmmH K+AduXIQ6OWRTI0P0jH67kSgEMcIQ0s= 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-480-3Uae16YCMmKa5OlHDpgs_A-1; Tue, 09 Feb 2021 07:57:17 -0500 X-MC-Unique: 3Uae16YCMmKa5OlHDpgs_A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DBDFB8030B7 for ; Tue, 9 Feb 2021 12:57:16 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-115-51.ams2.redhat.com [10.36.115.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 886667770C; Tue, 9 Feb 2021 12:57:16 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1CD1F113865F; Tue, 9 Feb 2021 13:57:15 +0100 (CET) From: Markus Armbruster To: Kevin Wolf Subject: Re: [PATCH 2/6] qapi: Remember alias definitions in qobject-input-visitor References: <20201112172850.401925-1-kwolf@redhat.com> <20201112172850.401925-3-kwolf@redhat.com> Date: Tue, 09 Feb 2021 13:57:15 +0100 In-Reply-To: <20201112172850.401925-3-kwolf@redhat.com> (Kevin Wolf's message of "Thu, 12 Nov 2020 18:28:46 +0100") Message-ID: <87sg65pff8.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=63.128.21.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=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: jsnow@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Let me look at the actual code now Kevin reduced my confusion about the interface and the data structures. Kevin Wolf writes: > This makes qobject-input-visitor remember the currently valid aliases in > each StackObject. It doesn't actually allow using the aliases yet. > > Signed-off-by: Kevin Wolf > --- > qapi/qobject-input-visitor.c | 115 +++++++++++++++++++++++++++++++++++ > 1 file changed, 115 insertions(+) > > diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c > index 23843b242e..a00ac32682 100644 > --- a/qapi/qobject-input-visitor.c > +++ b/qapi/qobject-input-visitor.c > @@ -29,6 +29,29 @@ > #include "qemu/cutils.h" > #include "qemu/option.h" > > +typedef struct InputVisitorAlias { > + /* Alias name. NULL for any (wildcard alias). */ > + const char *alias; > + > + /* > + * NULL terminated array representing a path. > + * Must contain at least one non-NULL element if alias is not NULL. > + */ > + const char **src; > + > + /* StackObject in which the alias should be looked for */ > + struct StackObject *alias_so; > + > + /* > + * The alias remains valid as long as the containing StackObject has > + * StackObject.alias_scope_nesting >= InputVisitorAlias.scope_nesting > + * or until the whole StackObject is removed. > + */ > + int scope_nesting; > + > + QSLIST_ENTRY(InputVisitorAlias) next; > +} InputVisitorAlias; > + > typedef struct StackObject { > const char *name; /* Name of @obj in its parent, if any */ > QObject *obj; /* QDict or QList being visited */ > @@ -38,6 +61,9 @@ typedef struct StackObject { > const QListEntry *entry; /* If @obj is QList: unvisited tail */ > unsigned index; /* If @obj is QList: list index of @entry */ > > + QSLIST_HEAD(, InputVisitorAlias) aliases; > + int alias_scope_nesting; /* Increase on scope start, decrease on end */ > + > QSLIST_ENTRY(StackObject) node; /* parent */ > } StackObject; > > @@ -203,6 +229,38 @@ static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv, > return qstring_get_str(qstr); > } > > +/* > + * Propagates aliases from the parent StackObject @src to its direct > + * child StackObject @dst, which is representing the child struct @name. @name must equal dst->name, I think. Drop the parameter? > + * > + * Every alias whose source path begins with @name and which still > + * applies in @dst (i.e. it is either a wildcard alias or has at least > + * one more source path element) is propagated to @dst with the first I'm not sure I get the parenthesis. Perhaps the code will enlighten me. > + * element (i.e. @name) removed from the source path. > + */ > +static void propagate_aliases(StackObject *dst, StackObject *src, > + const char *name) > +{ > + InputVisitorAlias *a; > + > + QSLIST_FOREACH(a, &src->aliases, next) { > + if (!a->src[0] || strcmp(a->src[0], name)) { > + continue; > + } We only look at the aliases that apply to @dst or below. They do only when ->src[0] equals dst->name. Makes sense. > + if (a->src[1] || !a->alias) { If a->src[1], the alias applies below @dst, not to @dst. To get it to the place where it applies, we first need to propagate to @dst. Else, the alias applies to @dst. If !a->alias, we're looking at a wildcard alias, i.e. all members of the object described by @dst are aliased. Why do we need to propagate only wildcard aliases to @dst? > + InputVisitorAlias *alias = g_new(InputVisitorAlias, 1); > + > + *alias = (InputVisitorAlias) { > + .alias = a->alias, > + .alias_so = a->alias_so, > + .src = &a->src[1], > + }; > + > + QSLIST_INSERT_HEAD(&dst->aliases, alias, next); > + } > + } > +} > + > static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv, > const char *name, > QObject *obj, void *qapi) > @@ -226,6 +284,9 @@ static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv, > g_hash_table_insert(h, (void *)qdict_entry_key(entry), NULL); > } > tos->h = h; > + if (!QSLIST_EMPTY(&qiv->stack)) { > + propagate_aliases(tos, QSLIST_FIRST(&qiv->stack), name); > + } What if QSLIST_EMPTY(&qiv->stack) and tos->aliases contains aliases that apply deeper? > } else { > assert(qlist); > tos->entry = qlist_first(qlist); > @@ -257,10 +318,17 @@ static bool qobject_input_check_struct(Visitor *v, Error **errp) > > static void qobject_input_stack_object_free(StackObject *tos) > { > + InputVisitorAlias *a; > + > if (tos->h) { > g_hash_table_unref(tos->h); > } > > + while ((a = QSLIST_FIRST(&tos->aliases))) { > + QSLIST_REMOVE_HEAD(&tos->aliases, next); > + g_free(a); > + } > + > g_free(tos); > } > > @@ -274,6 +342,50 @@ static void qobject_input_pop(Visitor *v, void **obj) > qobject_input_stack_object_free(tos); > } > > +static void qobject_input_start_alias_scope(Visitor *v) > +{ > + QObjectInputVisitor *qiv = to_qiv(v); > + StackObject *tos = QSLIST_FIRST(&qiv->stack); > + > + tos->alias_scope_nesting++; > +} > + > +static void qobject_input_end_alias_scope(Visitor *v) > +{ > + QObjectInputVisitor *qiv = to_qiv(v); > + StackObject *tos = QSLIST_FIRST(&qiv->stack); > + InputVisitorAlias *a, *next; > + > + assert(tos->alias_scope_nesting > 0); > + tos->alias_scope_nesting--; > + > + QSLIST_FOREACH_SAFE(a, &tos->aliases, next, next) { > + if (a->scope_nesting > tos->alias_scope_nesting) { > + QSLIST_REMOVE(&tos->aliases, a, InputVisitorAlias, next); > + g_free(a); > + } > + } > +} > + > +static void qobject_input_define_alias(Visitor *v, const char *alias_name, > + const char **source) > +{ > + QObjectInputVisitor *qiv = to_qiv(v); > + StackObject *tos = QSLIST_FIRST(&qiv->stack); > + InputVisitorAlias *alias = g_new(InputVisitorAlias, 1); > + > + /* The source path can only be empty for wildcard aliases */ > + assert(source[0] || !alias_name); Possibly related: the "What does .alias = NULL, .src[] empty mean?" we discussed previously. > + > + *alias = (InputVisitorAlias) { > + .alias = alias_name, > + .alias_so = tos, > + .src = source, > + }; > + > + QSLIST_INSERT_HEAD(&tos->aliases, alias, next); > +} > + > static bool qobject_input_start_struct(Visitor *v, const char *name, void **obj, > size_t size, Error **errp) > { > @@ -696,6 +808,9 @@ static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj) > v->visitor.end_list = qobject_input_end_list; > v->visitor.start_alternate = qobject_input_start_alternate; > v->visitor.optional = qobject_input_optional; > + v->visitor.define_alias = qobject_input_define_alias; > + v->visitor.start_alias_scope = qobject_input_start_alias_scope; > + v->visitor.end_alias_scope = qobject_input_end_alias_scope; > v->visitor.free = qobject_input_free; > > v->root = qobject_ref(obj);