From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 51696 invoked by alias); 13 Sep 2017 22:19:33 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 51686 invoked by uid 89); 13 Sep 2017 22:19:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-10.9 required=5.0 tests=BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 13 Sep 2017 22:19:31 +0000 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6E9E4C04B924 for ; Wed, 13 Sep 2017 22:19:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 6E9E4C04B924 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=palves@redhat.com 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 1CCF160841; Wed, 13 Sep 2017 22:19:27 +0000 (UTC) Subject: Re: [PATCH 1/4] Make gdb_dirbuf local to functions To: Sergio Durigan Junior References: <20170912042325.14927-1-sergiodj@redhat.com> <20170912042325.14927-2-sergiodj@redhat.com> <0e75c4bf-c9ec-7a07-f1e0-c9d7f11dd136@redhat.com> <87a81yz26g.fsf@redhat.com> Cc: GDB Patches From: Pedro Alves Message-ID: <0e5b1e93-20fa-b6ee-f7b9-eec4f8a50064@redhat.com> Date: Wed, 13 Sep 2017 22:19:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <87a81yz26g.fsf@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2017-09/txt/msg00366.txt.bz2 On 09/13/2017 11:03 PM, Sergio Durigan Junior wrote: > On Wednesday, September 13 2017, Pedro Alves wrote: >>> --- a/gdb/cli/cli-cmds.c >>> +++ b/gdb/cli/cli-cmds.c >>> @@ -380,6 +380,8 @@ quit_command (char *args, int from_tty) >>> static void >>> pwd_command (char *args, int from_tty) >>> { >>> + char gdb_dirbuf[BUFSIZ]; >> >> I don't recall offhand -- what's "BUFSIZ"? What defines it >> and is it guaranteed to be the right size for getcwd? > > BUFSIZ is defined by stdio.h, and is 8192 on my Fedora 25. This is much > greater than the previous "1024" that was being used before. Ah, that BUFSIZ. That's the FILE* stream buffer size [1], so I don't see it makes sense to use it for paths over PATH_MAX. It happens to be greater that 1024 on your system, but that's not guaranteed, no? [1] - http://pubs.opengroup.org/onlinepubs/9699919799/functions/setbuf.html http://pubs.opengroup.org/onlinepubs/009695399/basedefs/stdio.h.html > For reproducibility reasons I didn't want to use PATH_MAX. I don't understand this. Can you expand? What's not reproducible about PATH_MAX? How's that different from BUFSIZ? >> As an extension, on GNU/Linux, you can call 'getcwd (NULL, 0)' and >> that returns a heap-allocated buffer of the necessary size. Can we >> rely on gnulib to implement that behavior everywhere? Since >> it seems like we're xstrdup'ing the dir anyway, that likely would >> simplify things, and remove one arbitrary hardcoded limit, while >> at it. > > That's true, and it's better when you consider reproducible builds as > well. /me confused about that. > > According to gnulib: > > https://www.gnu.org/software/gnulib/manual/html_node/getcwd.html > > It is better to rely on this better version of getcwd. Alright. This makes the above moot, though I'd still like to understand the reproducibility argument, since I suspect that may come back in other cases. Thanks, Pedro Alves