From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH 1/2] tests: make test_must_fail more verbose Date: Tue, 31 Aug 2010 14:06:18 -0400 Message-ID: <20100831180618.GB15020@sigill.intra.peff.net> References: <20100831155457.GB11014@sigill.intra.peff.net> <20100831155636.GA11530@sigill.intra.peff.net> <20100831171055.GO2315@burratino> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Jon Seymour , git@vger.kernel.org, gitster@pobox.com To: Jonathan Nieder X-From: git-owner@vger.kernel.org Tue Aug 31 20:06:08 2010 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OqVDj-0005UN-Ip for gcvg-git-2@lo.gmane.org; Tue, 31 Aug 2010 20:06:07 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754409Ab0HaSGB (ORCPT ); Tue, 31 Aug 2010 14:06:01 -0400 Received: from xen6.gtisc.gatech.edu ([143.215.130.70]:54806 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754352Ab0HaSGA (ORCPT ); Tue, 31 Aug 2010 14:06:00 -0400 Received: (qmail 29413 invoked by uid 111); 31 Aug 2010 18:06:00 -0000 Received: from 99-108-226-0.lightspeed.iplsin.sbcglobal.net (HELO sigill.intra.peff.net) (99.108.226.0) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.40) with ESMTPA; Tue, 31 Aug 2010 18:06:00 +0000 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 31 Aug 2010 14:06:18 -0400 Content-Disposition: inline In-Reply-To: <20100831171055.GO2315@burratino> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Aug 31, 2010 at 12:10:55PM -0500, Jonathan Nieder wrote: > > - test $? -gt 0 -a $? -le 129 -o $? -gt 192 > [...] > Can the exit status (e.g. from a shell function) be negative? I don't believe so. Both bash and dash complain about "return -1" (and POSIX says the number must be "an unsigned decimal integer"). More importantly, though, is how shells interpret an exit status from a command that has high bits set. Both bash and dash truncate it to 8-bits and treat it as unsigned. I would think any reasonable shell would do that (no, I don't have a Solaris 8 box handy to test on. :) ). > Though your patch does not affect this, a command interrupted by a > signal will receive exit status > 192 in shells like ksh93. Yeah, that is from 5a26973 (t/test-lib.sh: exit with small negagive int is ok with test_must_fail, 2008-07-12). I'm not sure I agree with the intent of that commit. We should perhaps just eliminate all the places where we use negative exit codes. > Posix says: > As explained in other sections, certain exit status values > have been reserved for special uses and should be used by > applications only for those purposes: > > 126 > A file to be executed was found, but it was not an > executable utility. > 127 > A utility to be executed was not found. > >128 > A command was interrupted by a signal. Yup, that's what I have always assumed to be the case. > Unfortunately that does not agree with git usage. > > 129 > Incorrect command-line usage, or help requested > (rather than SIGHUP). Yeah, we might consider changing that. We indeed confuse it with SIGHUP: $ git log -h 2>/dev/null; echo $? 129 $ git log -p >/dev/null; echo $? [now killall -HUP git elsewhere] 129 We also use 128 for our generic die. I don't know if this is ever problematic. It has the high bit set like a signal, but you don't actually check the bits in the shell. And the actual representation at the C level is not the same. So part of me is in favor of changing these to something more "normal". I am slightly worried, though, about breaking some caller. It is a user-visible interface, though I suspect 99% of callers only ever cared whether it was 0 or not. > Here's a test_might_fail patch for consistency. I didn't even know about that one. :) They should definitely be kept in sync. I wonder if it is worth implemening must_fail in terms of might_fail. > test_might_fail () { > "$@" > - test $? -ge 0 -a $? -le 129 -o $? -gt 192 > + exit_code=$? > + if test $exit_code -gt 129 -a $exit_code -le 192; then > + echo >&2 "test_might_fail: died by signal: $*" > + return 1 > + fi > + return 0 I wonder if 2/2 would need the "missing command" bit, too. Hrm. -Peff