From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RCVD_IN_SORBS_SPAM, RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 9856220A36 for ; Tue, 7 Nov 2017 20:53:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933084AbdKGUx2 (ORCPT ); Tue, 7 Nov 2017 15:53:28 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:43474 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932298AbdKGUx1 (ORCPT ); Tue, 7 Nov 2017 15:53:27 -0500 Received: by mail-pg0-f68.google.com with SMTP id s75so425610pgs.0 for ; Tue, 07 Nov 2017 12:53:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=MtL7fgxXmN9BOg4kc9uOl1WfFUBZ3aDf7QCR8zlidyQ=; b=S058EdrT4l4A4yDBbAfBqV42RjUNBk8ZhJeZ+BVC3MhAc1pRxmn1m2Tw32twAVR96O EewWCfGDujBXsFn07N+pbh/xNMKfaSOSKqZJ4DhsAbB++csrZr6MyQKJ5P9SsGlJBHkl Lp2/kWRxg/MC/+D1KrISmChhnXXun2yYM+Wmfo0YvoPAn+yTZwjYGv3Sbnlo+0fmXKjj aJFiftWeLHs7O/CpE00pYojSDXB478KQdaLq4R/qZlB4SJb9+HJc+aOa+NQzH0j2Grn5 u5m1jf9EU6oMRvJ5stc0aP49q/4cjoCWJTeh0iCowdVJSKK5+XViEwIgM3QR0xxoaVc0 5riQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=MtL7fgxXmN9BOg4kc9uOl1WfFUBZ3aDf7QCR8zlidyQ=; b=rdMvK8ztTcfFtl9AE/bKvf/Ptv41At7xSSuxEYz9k/9tSfweHJv/IR5qKKqJd/yqFB deHBn9drxWicpPqNyzJtgbH965b3hHGdz0EK22UC+c3OzXKPSNOjHmBv71LDkQpgJf3u bQtvQ0fzPj8+qKAtr8FkAyz7cN92uan9wmjei+iej80MlCf9DWOd4D8w8ghXpnwDqFW3 8yJeFQ1rjeAMx6PR7WgZoGG0maOndcZBN7Nx2fLhFc/HWKlnPBkiK7VWxw4PcnuXI5Zn VGeRwZvthbTTKFc8WAEMvHgjYYQ7KpZXysJy+UwDu5V9vKMlhqBltnK1940/3raoBFRN KNcw== X-Gm-Message-State: AJaThX4EHfKN6Cti3DNVagwll0kcGkkGGxagEXkoQbMR7pqad+NHmn6H q7Por/AZv/uqaMnSlkRKZJB2om5cWZpqJZVsDw4= X-Google-Smtp-Source: ABhQp+SKCC6AQRzUyl+NUWXADTHMSPDBdtfS1r6tIW+xt90q9JWsr6zR37ewLNYzuYtMdIkKjgTAr5Za+iAhkd3JS3A= X-Received: by 10.159.198.131 with SMTP id g3mr7536plo.337.1510088007191; Tue, 07 Nov 2017 12:53:27 -0800 (PST) MIME-Version: 1.0 Received: by 10.100.177.141 with HTTP; Tue, 7 Nov 2017 12:53:26 -0800 (PST) In-Reply-To: <10901328af1e6e04e8c7c7b39977ec85f6c58142.1509870243.git.mhagger@alum.mit.edu> References: <10901328af1e6e04e8c7c7b39977ec85f6c58142.1509870243.git.mhagger@alum.mit.edu> From: =?UTF-8?Q?Martin_=C3=85gren?= Date: Tue, 7 Nov 2017 21:53:26 +0100 Message-ID: Subject: Re: [PATCH v2 3/9] ref_transaction_update(): die on disallowed flags To: Michael Haggerty Cc: Junio C Hamano , Eric Sunshine , Git Mailing List , Thomas Gummerer Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On 5 November 2017 at 09:42, Michael Haggerty wrote: > Callers shouldn't be passing disallowed flags into > `ref_transaction_update()`. So instead of masking them off, treat it > as a bug if any are set. > > Signed-off-by: Michael Haggerty > --- > refs.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/refs.c b/refs.c > index 62a7621025..7c1e206e08 100644 > --- a/refs.c > +++ b/refs.c > @@ -940,7 +940,8 @@ int ref_transaction_update(struct ref_transaction *transaction, > return -1; > } > > - flags &= REF_TRANSACTION_UPDATE_ALLOWED_FLAGS; > + if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS) > + BUG("illegal flags 0x%x passed to ref_transaction_update()", flags); > > flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0); The masking out is for sanity, but also partly to squelch a compiler-warning. Thomas reported [1] that dieing does not make the warning go away, but that masking out does. Of course, avoiding warnings is not the ultimate goal, and -Wnonnull is not part of DEVELOPER_CFLAGS. Thomas reluctantly suggested that one could do your check and then do the masking... Maybe it would be worth a note in the commit message. But blaming these lines quickly leads to c788c54cd (refs: strip out not allowed flags from ref_transaction_update, 2017-09-12), which describes this already. OTOH, since the warning does not hit these lines, but a bit below, maybe it's even worth a comment in the code. I'm not saying we should sprinkle comments for each warning we hit... Anyway, those were the thoughts than ran through my mind. [1] https://public-inbox.org/git/20170924204541.GA2853@hank/