From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 65761 invoked by alias); 27 Apr 2018 19:39:19 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 65747 invoked by uid 89); 27 Apr 2018 19:39:18 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:1454 X-HELO: mx1.redhat.com Received: from mx3-rdu2.redhat.com (HELO mx1.redhat.com) (66.187.233.73) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 27 Apr 2018 19:39:17 +0000 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1BBA241662E0; Fri, 27 Apr 2018 19:39:16 +0000 (UTC) Received: from [127.0.0.1] (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 790BA10B2B42; Fri, 27 Apr 2018 19:39:15 +0000 (UTC) Subject: Re: GDB 8.1 build error To: Simon Marchi References: <214C80CC-1173-41F6-AAA1-39C9D39E28B2@comcast.net> <454707570722fc0220074c0eca015a8f@polymtl.ca> Cc: Paul Koning , gdb@sourceware.org From: Pedro Alves Message-ID: <620c4459-0452-309b-925f-d18a37b49f5b@redhat.com> Date: Fri, 27 Apr 2018 20:00:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-SW-Source: 2018-04/txt/msg00033.txt.bz2 On 04/27/2018 08:18 PM, Simon Marchi wrote: > On 2018-04-27 15:08, Pedro Alves wrote: >> Oh, wait....  Your build line has no "-W" at all, it has "-w" instead?? >> How did that happen? > > When --disable-build-warnings is used, we don't put any -W/-Wno- flags: > > https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=gdb/warning.m4;h=f176a3291aa68acf0122609531abb4652425525b;hb=HEAD#l62 > >> Right, that's ill-formed, thus a gdb bug.  A const POD must either >> be initialized, or have a user-declared default constructor. >> >> So adding an explicit initializer like clang is suggesting should fix it: >> >>   const any_static_probe_ops any_static_probe_ops = {}; > > In the stackoverflow answer I pointed to in my other messages talks about a defect in the standard that was fixed. Oh, I had run into this in the past in context of an empty struct and thought that the bug fix was for that case only? http://open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#253 Oh geez, I assumed that any_static_probe_ops was a POD with function pointers, but now that I look, I see virtual methods... Anyhow. And it seems like the compilers aligned with the new behavior.  So is it really a GDB bug?  In any case, I have no problem adding the explicit initialization to be friendly with older compilers. Not sure anymore. But in any case I have no problems with the explicit initialization either. Thanks, Pedro Alves