From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: Latest GCC can't compile keymap.c correctly. Date: Thu, 07 Sep 2006 17:14:24 -0400 Message-ID: References: Reply-To: rms@gnu.org NNTP-Posting-Host: main.gmane.org Content-Type: text/plain; charset=ISO-8859-15 X-Trace: sea.gmane.org 1157663851 30497 80.91.229.2 (7 Sep 2006 21:17:31 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 7 Sep 2006 21:17:31 +0000 (UTC) Cc: j.s@jp.fujitsu.com, emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Sep 07 23:17:30 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1GLRFC-0005tP-Jy for ged-emacs-devel@m.gmane.org; Thu, 07 Sep 2006 23:17:08 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GLRFB-000143-T5 for ged-emacs-devel@m.gmane.org; Thu, 07 Sep 2006 17:17:05 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1GLRCe-0003yu-S8 for emacs-devel@gnu.org; Thu, 07 Sep 2006 17:14:28 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1GLRCe-0003xl-3b for emacs-devel@gnu.org; Thu, 07 Sep 2006 17:14:28 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GLRCd-0003xO-T8 for emacs-devel@gnu.org; Thu, 07 Sep 2006 17:14:27 -0400 Original-Received: from [199.232.76.164] (helo=fencepost.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.52) id 1GLRD6-0006VH-09 for emacs-devel@gnu.org; Thu, 07 Sep 2006 17:14:56 -0400 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.34) id 1GLRCa-0000ee-LT; Thu, 07 Sep 2006 17:14:24 -0400 Original-To: Kenichi Handa In-reply-to: (message from Kenichi Handa on Thu, 07 Sep 2006 11:31:12 +0900) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:59525 Archived-At: When we compile only keymap.c with gcc-4.0.3 and link it, the problem disappears. Either keymap.c has a bug or the latest GCC has a bug. We need to find out which function the problem is in. I suggest you split keymap.c into two files, and try compiling one with each GCC version. By moving functions between the two files you can determine where the problem is. (If you are using a high optimization level that does interprocedural optimization, you may need more subtle techniques to determine which function.) Once you know which function it is, make a .s file with each GCC version, and compare the two with each other and with the source code. This way you will find where the GCC 4.2 assenbly code is wrong. Then you can see whether there is something in the source code that has unspecified or undefined behavior. If so, we should fix that. If not, then it is a GCC bug, and you will have all the info needed to report it properly. I know this is a substantial amount of work, but it is the only way to solve the problem. And if this is a GCC bug, it is very important to fix it.