From patchwork Mon Aug 19 22:35:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 268315 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 36C662C0142 for ; Tue, 20 Aug 2013 08:34:12 +1000 (EST) Received: from localhost ([::1]:45117 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VBY1a-0002ip-BU for incoming@patchwork.ozlabs.org; Mon, 19 Aug 2013 18:34:10 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58701) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VBY0r-0002eI-6p for qemu-devel@nongnu.org; Mon, 19 Aug 2013 18:33:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VBY0g-0008O7-Ut for qemu-devel@nongnu.org; Mon, 19 Aug 2013 18:33:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63964) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VBY0g-0008O0-N5 for qemu-devel@nongnu.org; Mon, 19 Aug 2013 18:33:14 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r7JMXEbv015129 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 19 Aug 2013 18:33:14 -0400 Received: from lacos-laptop.usersys.redhat.com (vpn1-5-138.ams2.redhat.com [10.36.5.138]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r7JMXBph017933; Mon, 19 Aug 2013 18:33:13 -0400 From: Laszlo Ersek To: lcapitulino@redhat.com, qemu-devel@nongnu.org Date: Tue, 20 Aug 2013 00:35:33 +0200 Message-Id: <1376951740-23559-2-git-send-email-lersek@redhat.com> In-Reply-To: <1376951740-23559-1-git-send-email-lersek@redhat.com> References: <1376951740-23559-1-git-send-email-lersek@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 1/8] OptsVisitor: introduce basic list modes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org We're going to need more state while processing a list of repeated options. This change eliminates "repeated_opts_first" and adds a new state variable: list_mode repeated_opts repeated_opts_first -------------- ------------- ------------------- LM_NONE NULL false LM_STARTED non-NULL true LM_IN_PROGRESS non-NULL false Additionally, it is documented that lookup_scalar() and processed(), both called by opts_type_XXX(), are invalid in LM_STARTED -- generated qapi code calls opts_next_list() to allocate the very first link before trying to parse a scalar into it. List mode restrictions are expressed in positive / inclusive form. Signed-off-by: Laszlo Ersek --- qapi/opts-visitor.c | 45 +++++++++++++++++++++++++++++++++++---------- 1 files changed, 35 insertions(+), 10 deletions(-) diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c index 174bd8b..29fd1ab 100644 --- a/qapi/opts-visitor.c +++ b/qapi/opts-visitor.c @@ -1,7 +1,7 @@ /* * Options Visitor * - * Copyright Red Hat, Inc. 2012 + * Copyright Red Hat, Inc. 2012, 2013 * * Author: Laszlo Ersek * @@ -18,6 +18,15 @@ #include "qapi/visitor-impl.h" +enum ListMode +{ + LM_NONE, /* not traversing a list of repeated options */ + LM_STARTED, /* opts_start_list() succeeded */ + LM_IN_PROGRESS /* opts_next_list() has been called */ +}; + +typedef enum ListMode ListMode; + struct OptsVisitor { Visitor visitor; @@ -35,8 +44,8 @@ struct OptsVisitor /* The list currently being traversed with opts_start_list() / * opts_next_list(). The list must have a struct element type in the * schema, with a single mandatory scalar member. */ + ListMode list_mode; GQueue *repeated_opts; - bool repeated_opts_first; /* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for * uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does @@ -156,9 +165,11 @@ opts_start_list(Visitor *v, const char *name, Error **errp) OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v); /* we can't traverse a list in a list */ - assert(ov->repeated_opts == NULL); + assert(ov->list_mode == LM_NONE); ov->repeated_opts = lookup_distinct(ov, name, errp); - ov->repeated_opts_first = (ov->repeated_opts != NULL); + if (ov->repeated_opts != NULL) { + ov->list_mode = LM_STARTED; + } } @@ -168,10 +179,13 @@ opts_next_list(Visitor *v, GenericList **list, Error **errp) OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v); GenericList **link; - if (ov->repeated_opts_first) { - ov->repeated_opts_first = false; + switch (ov->list_mode) { + case LM_STARTED: + ov->list_mode = LM_IN_PROGRESS; link = list; - } else { + break; + + case LM_IN_PROGRESS: { const QemuOpt *opt; opt = g_queue_pop_head(ov->repeated_opts); @@ -180,6 +194,11 @@ opts_next_list(Visitor *v, GenericList **list, Error **errp) return NULL; } link = &(*list)->next; + break; + } + + default: + abort(); } *link = g_malloc0(sizeof **link); @@ -192,14 +211,16 @@ opts_end_list(Visitor *v, Error **errp) { OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v); + assert(ov->list_mode == LM_STARTED || ov->list_mode == LM_IN_PROGRESS); ov->repeated_opts = NULL; + ov->list_mode = LM_NONE; } static const QemuOpt * lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp) { - if (ov->repeated_opts == NULL) { + if (ov->list_mode == LM_NONE) { GQueue *list; /* the last occurrence of any QemuOpt takes effect when queried by name @@ -207,6 +228,7 @@ lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp) list = lookup_distinct(ov, name, errp); return list ? g_queue_peek_tail(list) : NULL; } + assert(ov->list_mode == LM_IN_PROGRESS); return g_queue_peek_head(ov->repeated_opts); } @@ -214,9 +236,12 @@ lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp) static void processed(OptsVisitor *ov, const char *name) { - if (ov->repeated_opts == NULL) { + if (ov->list_mode == LM_NONE) { g_hash_table_remove(ov->unprocessed_opts, name); + return; } + assert(ov->list_mode == LM_IN_PROGRESS); + /* do nothing */ } @@ -365,7 +390,7 @@ opts_start_optional(Visitor *v, bool *present, const char *name, OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v); /* we only support a single mandatory scalar field in a list node */ - assert(ov->repeated_opts == NULL); + assert(ov->list_mode == LM_NONE); *present = (lookup_distinct(ov, name, NULL) != NULL); }