From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55114) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dB1mR-0007BC-K9 for qemu-devel@nongnu.org; Wed, 17 May 2017 12:26:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dB1mN-0006wt-LD for qemu-devel@nongnu.org; Wed, 17 May 2017 12:26:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48876) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dB1mN-0006wC-CZ for qemu-devel@nongnu.org; Wed, 17 May 2017 12:26:27 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4A92213A60 for ; Wed, 17 May 2017 16:26:26 +0000 (UTC) From: Markus Armbruster References: <20170509173559.31598-1-marcandre.lureau@redhat.com> <20170509173559.31598-9-marcandre.lureau@redhat.com> <87pof86750.fsf@dusky.pond.sub.org> Date: Wed, 17 May 2017 18:26:22 +0200 In-Reply-To: <87pof86750.fsf@dusky.pond.sub.org> (Markus Armbruster's message of "Tue, 16 May 2017 19:31:07 +0200") Message-ID: <87d1b71mc1.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 08/17] qapi: update the qobject visitor to use QUInt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, Eric Blake Markus Armbruster writes: > On the subject: there is no such thing as "QUInt". I guess you mean > "uint type" (like in PATCH 06's subject). Could also say "QNUM_U64". > > Apropos subject: humor me, and start your subjects with a capital > letter, like this: > > qapi: Update the qobject visitor ... > > Marc-Andr=C3=A9 Lureau writes: > >> Switch to use QNum/uint where appropriate to remove i64 limitation. >> >> The input visitor will cast i64 input to u64 for compatibility >> reasons (existing json QMP client already use negative i64 for large >> u64, and expect an implicit cast in qemu). >> >> Signed-off-by: Marc-Andr=C3=A9 Lureau >> --- >> qapi/qobject-input-visitor.c | 13 +++++++++++-- >> qapi/qobject-output-visitor.c | 3 +-- >> tests/test-qobject-output-visitor.c | 21 ++++++++++++++++----- >> 3 files changed, 28 insertions(+), 9 deletions(-) >> >> diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c >> index 785949ebab..72cefcf677 100644 >> --- a/qapi/qobject-input-visitor.c >> +++ b/qapi/qobject-input-visitor.c >> @@ -420,9 +420,9 @@ static void qobject_input_type_int64_keyval(Visitor = *v, const char *name, >> static void qobject_input_type_uint64(Visitor *v, const char *name, >> uint64_t *obj, Error **errp) >> { >> - /* FIXME: qobject_to_qnum mishandles values over INT64_MAX */ >> QObjectInputVisitor *qiv =3D to_qiv(v); >> QObject *qobj =3D qobject_input_get_object(qiv, name, true, errp); >> + Error *err =3D NULL; >> QNum *qnum; >>=20=20 >> if (!qobj) { >> @@ -435,7 +435,16 @@ static void qobject_input_type_uint64(Visitor *v, c= onst char *name, >> return; >> } >>=20=20 >> - *obj =3D qnum_get_int(qnum, errp); >> + /* XXX: compatibility case, accept negative values as u64 */ > > What does "XXX" signify? > >> + *obj =3D qnum_get_int(qnum, &err); >> + > > Shouldn't the comment go right here? Nope, I misread the code. We first try qnum_get_int(). Works for integers between -2^63 and 2^63-1. The assignment to *obj adds 2^64 to negative ones. When it doesn't work, we try qnum_get_uint(). Works for integers between 0 and 2^64-1, but only integers between 2^63 and 2^64-1 can occur. >> + if (err) { >> + error_free(err); >> + err =3D NULL; >> + *obj =3D qnum_get_uint(qnum, &err); >> + } >> + >> + error_propagate(errp, err); >> } Let's do this the other way round: *obj =3D qnum_get_uint(qnum, &err); if (err) { /* Need to accept negative values for backward compatibility */ error_free(err); err =3D NULL; *obj =3D qnum_get_int(qnum, &err); } error_propagate(errp, err); This way, the backward compatibility code is entirely contained in the conditional. It's also how I misread the code :) [...]