From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=qfmR=A6=gmail.com=jwakely.gcc@sourceware.org>
Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534])
	by sourceware.org (Postfix) with ESMTPS id 6CB933858C2B
	for <gcc@gcc.gnu.org>; Tue,  9 May 2023 22:46:03 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6CB933858C2B
Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com
Received: by mail-ed1-x534.google.com with SMTP id 4fb4d7f45d1cf-50bd2d7ba74so63371272a12.1
        for <gcc@gcc.gnu.org>; Tue, 09 May 2023 15:46:03 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20221208; t=1683672362; x=1686264362;
        h=cc:to:subject:message-id:date:from:in-reply-to:references
         :mime-version:from:to:cc:subject:date:message-id:reply-to;
        bh=gZJDDCYQFrvdyKQpxwAm17RtoPiAFcx6MiWpommkEpE=;
        b=JVOAxP8btrImXwa5npl/Sl5keghpZCWzAL/2/zHpIZgbEV8MwEmgKB8s34dN5oQLEj
         cK3G3esy/Dawgp0589sQ5onXNtyWWczej2SHT71xTahrmUVV84UhDqKpnmM5N5bpI99C
         ZstL9YICgTdx0tjMritO2Z3hg8OAU+aO7NLYQOf4XjRscuOjUTpN0L1xB+h+ta4/atAh
         Hf+1Rf31G/i6sJwgYsAsWM6UbobKQwgUCL+YGuBWd4NQpyTwevHTCZlm+sGZUm7Xi2g1
         tHXytkmek4N+akQ0vkpernGwhrtX1nv+HcxN3h8N9OhXAO6n4mGl0ctXU2IUMFcWccOl
         /kug==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20221208; t=1683672362; x=1686264362;
        h=cc:to:subject:message-id:date:from:in-reply-to:references
         :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id
         :reply-to;
        bh=gZJDDCYQFrvdyKQpxwAm17RtoPiAFcx6MiWpommkEpE=;
        b=AN5nLb6PQSTC4gkRl7DQKIwis8Wi+4UbN+KglN518hxTQfnWx7u6Rw5Zsfge+Nql8K
         8utrdhKvHwlTGGOKCyDgI1CjmRWZVV6IrnowMVsgGgdiuaqWieNycsh7Bm8BMDbYuiEg
         mxYBCFXm6MPhlUTQ01rORfyqFK5ogVVnG/EQByV9HTBUEjz/gZMbchics1KL6x2lNcjr
         Vzxr0W+mONhasyGKTWYojvUkzHQJC03B87SKVVfhX8zR8F2j+YGotGOy5vJ8MyxLIgpb
         Ut2AzIaF40lVHCHYr1w56sGLpYstQx0Wm/lMDUcC8C1iVwMIhxKnyZ6+BhwMy8U/hWLo
         jAvw==
X-Gm-Message-State: AC+VfDxQGIRlFpR30/43OPo8qaW6lBesuckGdu4doXVnXjby/dezLeyl
	aPFuV4KGV4HzgWunepOOUXxv3M/vmWhNQfx21AY=
X-Google-Smtp-Source: ACHHUZ4aNgmSqXmRQvIRXS40OSwkWLVdn7C4u1KuI5g0z9zzNO60SGWQZ+8XPZC5nIl0hw7lcKe+nqA4is+nmHk73ok=
X-Received: by 2002:a17:907:8a24:b0:969:e993:6ff0 with SMTP id
 sc36-20020a1709078a2400b00969e9936ff0mr3601453ejc.25.1683672362024; Tue, 09
 May 2023 15:46:02 -0700 (PDT)
MIME-Version: 1.0
References: <877cth66qb.fsf@oldenburg.str.redhat.com> <CAGWvnykoEtT0BQtuN70DN6tWohtf=Mm7SW55psZvVmj3OvKUEg@mail.gmail.com>
 <CAH6eHdS5=AED+7MSe0prr8CZ-sYqnD159OjhTp9=R-a0aBZ3qw@mail.gmail.com>
 <20230509102201.6aa2a7d14fdb2f1e7abff449@killthe.net> <87r0rp5uf8.fsf@aarsen.me>
 <83ttwla1ep.fsf@gnu.org> <CAH6eHdS-7USHzX3rPJaR66sEdjG+-nHp7mDb0gD7ceBnp+Fmpg@mail.gmail.com>
 <83lehx9vix.fsf@gnu.org> <ZFqZ25xKm4w4IkqF@tucnak> <83fs859unu.fsf@gnu.org>
 <CAGWvny=xi++Ghyo2Ez5MJdYy5h3yH16gVpviKC99Ufu_bUmdYQ@mail.gmail.com>
 <CAH6eHdRAVwBcCmBgiuPyQNWGx3x33diAgQU8UG3s_NrJxK3ucQ@mail.gmail.com>
 <CAGWvnyk_MkQOrNNh1C=ubPj8qzg5x-p8CBfgWNqqtDVJ1mbhMg@mail.gmail.com> <CAF9ehCWsq-N9+U1+mTQahKT7cXEqLTptLb=b3Yq58gsWFEnxgA@mail.gmail.com>
In-Reply-To: <CAF9ehCWsq-N9+U1+mTQahKT7cXEqLTptLb=b3Yq58gsWFEnxgA@mail.gmail.com>
From: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Tue, 9 May 2023 23:45:50 +0100
Message-ID: <CAH6eHdS_sQ37VTpJHL7cqtgSdCSL3i4=tqMoY65wep9G56cf5g@mail.gmail.com>
Subject: Re: More C type errors by default for GCC 14
To: joel@rtems.org
Cc: David Edelsohn <dje.gcc@gmail.com>, Eli Zaretskii <eliz@gnu.org>, Jakub Jelinek <jakub@redhat.com>, 
	=?UTF-8?Q?Arsen_Arsenovi=C4=87?= <arsen@aarsen.me>, 
	"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=-0.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,KAM_NUMSUBJECT,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org
List-Id: <gcc.gcc.gnu.org>

On Tue, 9 May 2023 at 23:38, Joel Sherrill wrote:
> We are currently using gcc 12 and specifying C11.  To experiment with
> these stricter warnings and slowly address them, would we need to build
> with a newer C version?

No, the proposed changes are to give errors (instead of warnings) for
rules introduced in C99. GCC is just two decades late in enforcing the
C99 rules properly!


> What practices might the GCC community recommend to a project
> wanting to discover the issues uncovered and slowly address them? I

-Werror=implicit-int
-Werror=implicit-function-declaration
-Werror=int-conversion

> i am a bit gun shy because I remember the move from GCC 3.3 to 3.4
> where the improved strict alias checking gave us a LOT of warnings to
> deal with and it felt overwhelming. I don't want to do that again.
>
> But I believe in letting the compiler get stricter and find things. Defaulting
> to stricter checking is a good thing.

The checks are already done, they're just warnings by default, and so
easily missed/ignored when compiling large code bases.