From owner-svn-src-head@freebsd.org Mon Oct 15 13:53:37 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B904010DC4C3; Mon, 15 Oct 2018 13:53:37 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-it1-f175.google.com (mail-it1-f175.google.com [209.85.166.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 624B6756B4; Mon, 15 Oct 2018 13:53:37 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: by mail-it1-f175.google.com with SMTP id 134-v6so28727508itz.2; Mon, 15 Oct 2018 06:53:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=8RTlPaIF4kfDygHaKhxs0u48PYaeoacKZkQB8g6vxHM=; b=KK9PNjFb38SMl4A2fVVulADeLP66aVjaA2kstiW4ZcVUFLxhpCJY/D4/TWTmYZiwuk b+BRjyzxcWBmL1IZ/I2nxKDASLhO/wA9IECu74/hQgpEDXa9vCZixm/NjlXEBU9B3MKu Kk9jOp0qr6DHlSDi0KBX4eo2k0D9x4JvYYnDdeG3EBjwHen7J2FlQ8F4DVaw4NxpFs5W BkNmQ26EEKSGap2jxr5D9GoXNDjCy0qiSgNR7kDsWMpv51SNeqYEYxDpTHma+M/ky5OS imGY2RZkC1Nyj2s4r/PfWNQr4VvToGBNwOE+ZTiAvv36GkZn2MgwgKjOv9dC2GJxwxKL XCng== X-Gm-Message-State: ABuFfohQ1gfQWFi1yfcbnM0gTs0Jd9DC0u3JD0YCpoGMrQM7amxXiHUG NyFwQ7BOc9fNvKDrNC+sCYTeCywxtssXzAG3/PVYaA== X-Google-Smtp-Source: ACcGV60b22UB7VmYZn8567lnSc9YfW2lIHUAbV1eOrW4Z54U0CMu3NKIbRAo+8ljAeTrRUtG9WnXWh/BQzNjbCi0+XI= X-Received: by 2002:a24:7012:: with SMTP id f18-v6mr12085622itc.87.1539611610569; Mon, 15 Oct 2018 06:53:30 -0700 (PDT) MIME-Version: 1.0 References: <201810132126.w9DLQ73C022496@repo.freebsd.org> In-Reply-To: From: Ed Maste Date: Mon, 15 Oct 2018 05:54:34 -0400 Message-ID: Subject: Re: svn commit: r339350 - head/contrib/elftoolchain/elfcopy To: Antoine Brodin , gerald@freebsd.org Cc: FreeBSD Release Engineering Team , src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Oct 2018 13:53:37 -0000 On Mon, 15 Oct 2018 at 07:13, Ed Maste wrote: > > Hi Antoine, did you bisect to this rev or does it just look like the > most probable candidate? Can you copy a pair of differing .o files > (say, gcc/cc1plus-checksum.o) from the work dir to freefall? Antoine provided a tarball of the work dir to me, and pointed out that the *-checksum.o files are not interesting - they are warnings only and are present prior to the identified change. Comparing one of the other differing files, e.g. stage{2,3}-gcc/expmed.o, demonstrates the problem. Gcc's build machinery is reasonably obfuscated so I'm not sure of the exact set of operations, but I can infer that the stage2/stage3 comparison is running strip on the object files and then comparing the result. Gcc is encountering this part of my strip/objcopy change: > Stripping binaries with relocations > referencing removed symbols was already broken, and after this change > may still be broken in a different way. Stripping symbols and relocations from an object file is not a particularly useful operation, since the object then can't be linked or otherwise used. But it seems Gcc's stage comparison relies on this. I did try running "strip --strip-debug" on stage{2,3}-gcc/expmed.o (a reasonable operation on object files) and that produced identical output. It may well be that a further change to ELF Tool Chain's strip is warranted, but I suspect the most straightforward and reliable fix here will be to just have gcc use GNU strip.