From patchwork Tue Mar 27 12:20:46 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 148929 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BEB33B6EF1 for ; Tue, 27 Mar 2012 23:21:31 +1100 (EST) Received: from localhost ([::1]:33278 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVOz-0001Vn-Dt for incoming@patchwork.ozlabs.org; Tue, 27 Mar 2012 08:21:29 -0400 Received: from eggs.gnu.org ([208.118.235.92]:50162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVOY-000126-4x for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:21:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SCVOV-0000Kq-OD for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:21:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4377) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SCVOV-0000KX-Gu for qemu-devel@nongnu.org; Tue, 27 Mar 2012 08:20:59 -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 q2RCKwoE032610 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 27 Mar 2012 08:20:58 -0400 Received: from localhost (ovpn-113-71.phx2.redhat.com [10.3.113.71]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q2RCKvuX025885; Tue, 27 Mar 2012 08:20:57 -0400 From: Luiz Capitulino To: aliguori@us.ibm.com Date: Tue, 27 Mar 2012 09:20:46 -0300 Message-Id: <1332850851-4059-9-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1332850851-4059-1-git-send-email-lcapitulino@redhat.com> References: <1332850851-4059-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Paolo Bonzini , qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 08/13] qapi: untangle next_list 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 From: Paolo Bonzini Right now, the semantics of next_list are complicated. The caller must: * call start_list * call next_list for each element *including the first* * on the first call to next_list, the second argument should point to NULL and the result is the head of the list. On subsequent calls, the second argument should point to the last node (last result of next_list) and next_list itself tacks the element at the tail of the list. This works for both input and output visitor, but having the visitor write memory when it is only reading the list is ugly. Plus, relying on *list to detect the first call is tricky and undocumented. We can initialize so->entry in next_list instead of start_list, leaving it NULL in start_list. This way next_list sees clearly whether it is on the first call---as a bonus, it discriminates the cases based on internal state of the visitor rather than external state. We can also pull the assignment of the list head from generated code up to next_list. Signed-off-by: Paolo Bonzini Reviewed-by: Michael Roth Signed-off-by: Luiz Capitulino --- docs/qapi-code-gen.txt | 4 ++-- qapi/qmp-input-visitor.c | 22 +++++++++++++--------- scripts/qapi-visit.py | 4 ++-- 3 files changed, 17 insertions(+), 13 deletions(-) diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index 5831e37..ad11767 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -194,11 +194,11 @@ Example: void visit_type_UserDefOneList(Visitor *m, UserDefOneList ** obj, const char *name, Error **errp) { - GenericList *i; + GenericList *i, **prev = (GenericList **)obj; visit_start_list(m, name, errp); - for (i = visit_next_list(m, (GenericList **)obj, errp); i; i = visit_next_list(m, &i, errp)) { + for (; (i = visit_next_list(m, prev, errp)) != NULL; prev = &i) { UserDefOneList *native_i = (UserDefOneList *)i; visit_type_UserDefOne(m, &native_i->value, NULL, errp); } diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index ef9288f..413e333 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -64,9 +64,7 @@ static const QObject *qmp_input_get_object(QmpInputVisitor *qiv, static void qmp_input_push(QmpInputVisitor *qiv, const QObject *obj, Error **errp) { qiv->stack[qiv->nb_stack].obj = obj; - if (qobject_type(obj) == QTYPE_QLIST) { - qiv->stack[qiv->nb_stack].entry = qlist_first(qobject_to_qlist(obj)); - } + qiv->stack[qiv->nb_stack].entry = NULL; qiv->nb_stack++; if (qiv->nb_stack >= QIV_STACK_SIZE) { @@ -132,18 +130,24 @@ static GenericList *qmp_input_next_list(Visitor *v, GenericList **list, QmpInputVisitor *qiv = to_qiv(v); GenericList *entry; StackObject *so = &qiv->stack[qiv->nb_stack - 1]; + bool first; + + if (so->entry == NULL) { + so->entry = qlist_first(qobject_to_qlist(so->obj)); + first = true; + } else { + so->entry = qlist_next(so->entry); + first = false; + } if (so->entry == NULL) { return NULL; } entry = g_malloc0(sizeof(*entry)); - if (*list) { - so->entry = qlist_next(so->entry); - if (so->entry == NULL) { - g_free(entry); - return NULL; - } + if (first) { + *list = entry; + } else { (*list)->next = entry; } diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py index 31d50a6..8d4e94a 100644 --- a/scripts/qapi-visit.py +++ b/scripts/qapi-visit.py @@ -86,14 +86,14 @@ def generate_visit_list(name, members): void visit_type_%(name)sList(Visitor *m, %(name)sList ** obj, const char *name, Error **errp) { - GenericList *i, **head = (GenericList **)obj; + GenericList *i, **prev = (GenericList **)obj; if (error_is_set(errp)) { return; } visit_start_list(m, name, errp); - for (*head = i = visit_next_list(m, head, errp); i; i = visit_next_list(m, &i, errp)) { + for (; (i = visit_next_list(m, prev, errp)) != NULL; prev = &i) { %(name)sList *native_i = (%(name)sList *)i; visit_type_%(name)s(m, &native_i->value, NULL, errp); }