1 Return-Path: <ethan.glasser.camp@gmail.com>
\r
2 X-Original-To: notmuch@notmuchmail.org
\r
3 Delivered-To: notmuch@notmuchmail.org
\r
4 Received: from localhost (localhost [127.0.0.1])
\r
5 by olra.theworths.org (Postfix) with ESMTP id 543AE431FAF
\r
6 for <notmuch@notmuchmail.org>; Sat, 20 Oct 2012 18:46:45 -0700 (PDT)
\r
7 X-Virus-Scanned: Debian amavisd-new at olra.theworths.org
\r
11 X-Spam-Status: No, score=-0.799 tagged_above=-999 required=5
\r
12 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1,
\r
13 FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7] autolearn=disabled
\r
14 Received: from olra.theworths.org ([127.0.0.1])
\r
15 by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024)
\r
16 with ESMTP id XDU51ezOWXJZ for <notmuch@notmuchmail.org>;
\r
17 Sat, 20 Oct 2012 18:46:44 -0700 (PDT)
\r
18 Received: from mail-vc0-f181.google.com (mail-vc0-f181.google.com
\r
19 [209.85.220.181]) (using TLSv1 with cipher RC4-SHA (128/128 bits))
\r
20 (No client certificate requested)
\r
21 by olra.theworths.org (Postfix) with ESMTPS id 9405C431FAE
\r
22 for <notmuch@notmuchmail.org>; Sat, 20 Oct 2012 18:46:44 -0700 (PDT)
\r
23 Received: by mail-vc0-f181.google.com with SMTP id n11so1909718vch.26
\r
24 for <notmuch@notmuchmail.org>; Sat, 20 Oct 2012 18:46:42 -0700 (PDT)
\r
25 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
\r
26 h=from:to:subject:in-reply-to:references:user-agent:date:message-id
\r
27 :mime-version:content-type;
\r
28 bh=im1CbZ8uFOgVenJY3mO7AtoSAq28Pgp+cjOV+l2zAhQ=;
\r
29 b=nVNIiHE8ZLfgVINsPs1Ggnpjv4llZQv/2HLzjbZ1ziUnlolEt4ZCHHbgjtMY+Y0aFE
\r
30 0inYfK0YITIaUnteBL7iUmwxeDnx+g+p48BFzXliG78+ZDbl29oSNv8k/eRLMppPIuLH
\r
31 YMUdo3j8eXdSpWKf2P9xHWSWQ4sF1FPpiN9vXx54pcJbdbvAvFuv25LyTmfD7B+IOwY5
\r
32 2ui8wRysOVk9jME+DZ7/TFtJ8sBlvCtw2HgAK/LIOaF4ilIlSMHQQNwM5Ru8Iif79teD
\r
33 Ra2C/0U+4e85eArjNcepwMiBiMTVcjgbqlX8vXG591qiUcIZOU4g6syLHpX4/CfgWvm3
\r
35 Received: by 10.220.220.5 with SMTP id hw5mr8024596vcb.53.1350784002732;
\r
36 Sat, 20 Oct 2012 18:46:42 -0700 (PDT)
\r
37 Received: from smtp.gmail.com (p70-80.acedsl.com. [66.114.70.80])
\r
38 by mx.google.com with ESMTPS id y15sm6004289vdt.9.2012.10.20.18.46.40
\r
39 (version=TLSv1/SSLv3 cipher=OTHER);
\r
40 Sat, 20 Oct 2012 18:46:41 -0700 (PDT)
\r
41 From: Ethan Glasser-Camp <ethan.glasser.camp@gmail.com>
\r
42 To: Jani Nikula <jani@nikula.org>, notmuch@notmuchmail.org
\r
43 Subject: Re: [PATCH] lib: fix warnings when building with clang
\r
44 In-Reply-To: <1349076971-2065-1-git-send-email-jani@nikula.org>
\r
45 References: <1349076971-2065-1-git-send-email-jani@nikula.org>
\r
46 User-Agent: Notmuch/0.14+45~g6ea9330 (http://notmuchmail.org) Emacs/23.3.1
\r
47 (x86_64-pc-linux-gnu)
\r
48 Date: Sat, 20 Oct 2012 21:46:39 -0400
\r
49 Message-ID: <87pq4c61hc.fsf@betacantrips.com>
\r
51 Content-Type: text/plain; charset=us-ascii
\r
52 X-BeenThere: notmuch@notmuchmail.org
\r
53 X-Mailman-Version: 2.1.13
\r
55 List-Id: "Use and development of the notmuch mail system."
\r
56 <notmuch.notmuchmail.org>
\r
57 List-Unsubscribe: <http://notmuchmail.org/mailman/options/notmuch>,
\r
58 <mailto:notmuch-request@notmuchmail.org?subject=unsubscribe>
\r
59 List-Archive: <http://notmuchmail.org/pipermail/notmuch>
\r
60 List-Post: <mailto:notmuch@notmuchmail.org>
\r
61 List-Help: <mailto:notmuch-request@notmuchmail.org?subject=help>
\r
62 List-Subscribe: <http://notmuchmail.org/mailman/listinfo/notmuch>,
\r
63 <mailto:notmuch-request@notmuchmail.org?subject=subscribe>
\r
64 X-List-Received-Date: Sun, 21 Oct 2012 01:46:45 -0000
\r
66 Jani Nikula <jani@nikula.org> writes:
\r
68 > Building notmuch with CC=clang and CXX=clang++ produces the warnings:
\r
71 > lib/tags.c:43:5: warning: expression result unused [-Wunused-value]
\r
72 > talloc_steal (tags, list);
\r
73 > ^~~~~~~~~~~~~~~~~~~~~~~~~
\r
74 > /usr/include/talloc.h:345:143: note: expanded from:
\r
75 > ...__location__); __talloc_steal_ret; })
\r
76 > ^~~~~~~~~~~~~~~~~~
\r
77 > 1 warning generated.
\r
79 > CXX -O2 lib/message.o
\r
80 > lib/message.cc:791:5: warning: expression result unused [-Wunused-value]
\r
81 > talloc_reference (message, message->tag_list);
\r
82 > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\r
83 > /usr/include/talloc.h:932:36: note: expanded from:
\r
84 > ...(_TALLOC_TYPEOF(ptr))_talloc_reference_loc((ctx),(ptr), __location__)
\r
85 > ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\r
86 > 1 warning generated.
\r
88 > Check talloc_reference() return value, and explicitly ignore
\r
89 > talloc_steal() return value as it has no failure modes, to silence the
\r
92 > lib/message.cc | 4 +++-
\r
94 > 2 files changed, 4 insertions(+), 2 deletions(-)
\r
96 > diff --git a/lib/message.cc b/lib/message.cc
\r
97 > index 978de06..320901f 100644
\r
98 > --- a/lib/message.cc
\r
99 > +++ b/lib/message.cc
\r
100 > @@ -788,7 +788,9 @@ notmuch_message_get_tags (notmuch_message_t *message)
\r
101 > * possible to modify the message tags (which talloc_unlink's the
\r
102 > * current list from the message) while still iterating because
\r
103 > * the iterator will keep the current list alive. */
\r
104 > - talloc_reference (message, message->tag_list);
\r
105 > + if (!talloc_reference (message, message->tag_list))
\r
111 Hi! What you did with talloc_steal is obviously fine.
\r
113 I'd be happier about what you did with talloc_reference() if there were
\r
114 precedent, or a clearly-articulated convention for notmuch. Instead this
\r
115 is the third use in the codebase that I can see, and the other two are
\r
116 each unique to themselves. In mime-node.c we print an "out-of-memory"
\r
117 error and in lib/filenames.c we cast (void) talloc_reference (...), I
\r
118 guess figuring that we're pretty much hosed anyhow if we run out of
\r
121 Why return NULL here? It seems like if talloc_reference fails, we're
\r
122 going to crash eventually, so we should print an error to explain our
\r
123 impending doom. I'd guess you're uneasy printing anything from lib/, but
\r
124 still want to signal an error, and the only way you can do so is to
\r
125 return NULL. I guess that silences the compiler warning, but it's not
\r
126 really the correct way to handle the error IMO. On the other hand, it's
\r
127 such a weird corner case that I don't even think it merits a FIXME
\r
130 How about an assert instead of a return NULL?
\r