From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vadim Zeitlin Subject: Re: [PATCH] Avoid false positives in label detection in cpp diff hunk header regex. Date: Sat, 23 Mar 2013 09:48:30 +0000 (UTC) Message-ID: References: <7vehf78olw.fsf@alter.siamese.dyndns.org> <514CD34F.70107@kdbg.org> <7vhak35ami.fsf@alter.siamese.dyndns.org> <514CE53F.3080308@kdbg.org>

Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Sat Mar 23 10:49:25 2013 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UJL4j-0004AT-Fs for gcvg-git-2@plane.gmane.org; Sat, 23 Mar 2013 10:49:21 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755280Ab3CWJsx (ORCPT ); Sat, 23 Mar 2013 05:48:53 -0400 Received: from plane.gmane.org ([80.91.229.3]:54219 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546Ab3CWJsw (ORCPT ); Sat, 23 Mar 2013 05:48:52 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UJL4b-00044k-JE for git@vger.kernel.org; Sat, 23 Mar 2013 10:49:13 +0100 Received: from ip-208.net-89-3-60.rev.numericable.fr ([89.3.60.208]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 23 Mar 2013 10:49:13 +0100 Received: from vz-git by ip-208.net-89-3-60.rev.numericable.fr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 23 Mar 2013 10:49:13 +0100 X-Injected-Via-Gmane: http://gmane.org/ X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: sea.gmane.org User-Agent: Loom/3.14 (http://gmane.org/) X-Loom-IP: 89.3.60.208 (Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20100101 Firefox/19.0) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Andreas Schwab linux-m68k.org> writes: > Vadim Zeitlin zeitlins.org> writes: > > > "!^[ \t]*[A-Za-z_][A-Za-z_0-9]+[ \t]*:([^:]|$)\n" > > That would fail to match single-character identifiers. Oops, yes, you're right, of course, sorry. I have no idea why did I write that we needed to change this "*" to "+", the only explanation I see is that it was simply too late at night when I did it. So the final version of the exclusion regex is "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*[ \t]*:([^:]|$)\n" But I feel like I'm still missing something about what is going on here. Because after looking carefully at the (positive) regex for matching function and method names, which is "^([A-Za-z_][A-Za-z_0-9]*([ \t*]+[A-Za-z_][A-Za-z_0-9]*" "([ \t]*::[ \t]*[^[:space:]]+)?){1,}[ \t]*\\([^;]*)$\n" (split over 2 lines for readability), I actually don't understand how does it manage to match my declaration. Yet match it does, I do get @@ -438,6 +438,10 @@ firebird_statement_backend::execute(int number) in my diff. But how is this possible? The "[ \t*]+" part has nowhere to match but between "int" and "number" but it can't match there because there must be only alphanumeric characters before it. Yet, not only it does match but if I test with GNU grep -E, it matches too (after replacing "\\(" with just "\(" and removing "\n"). However if I test with perl or "sed -r", it does *not* match. Can anyone see what's going on here? FWIW I've started looking into this because I thought that the current regex wouldn't detect something like foo::nested_type foo::method() as a start of a method. However it does detect this just fine as well which I can't understand at all. I'm out of lame excuses (it's not too late here yet...) so I just hope that I'm missing something about the way Git creates hunk headers and not some obvious problem with the regex itself because I've been staring at it for half an hour but still can't see how does it manage to match here. Could anyone who does see it please explain? Thanks in advance, VZ