Mailing-List: contact dev-help@httpd.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@httpd.apache.org
Received-SPF: pass (asf.osuosl.org: local policy)
From: Jim Jagielski <jim@jaguNET.com>
Message-Id: <200510031238.j93Cc6a01631@devsys.jaguNET.com>
Subject: Re: svn commit: r293305 - in /httpd/httpd/branches/2.2.x/modules:
 dav/fs/dbm.c
To: dev@httpd.apache.org
Date: Mon, 3 Oct 2005 08:38:02 -0400 (EDT)
Reply-To: jim@jaguNET.com
In-Reply-To: <20051003122839.GG6219@redhat.com> from "Joe Orton" at Oct 03,
 2005 01:28:39 PM
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Joe Orton wrote:
> 
> On Mon, Oct 03, 2005 at 08:11:44AM -0400, Jim Jagielski wrote:
> > Joe Orton wrote:
> > > 
> > > On Mon, Oct 03, 2005 at 07:50:39AM -0400, Jim Jagielski wrote:
> > > > Just some lines that caught my eye:
> > > > 
> > > > >  
> > > > > -    *context = (void *)(value == 'T');
> > > > > +    *context = (void *)((long)(value == 'T'));
> > > > >  
> > > > > -    int value = context != NULL;
> > > > > +    long value = context != NULL;
> > > > >      apr_fileperms_t perms = resource->info->finfo.protection;
> > > > > -    int old_value = (perms & APR_UEXECUTE) != 0;
> > > > > +    long old_value = (perms & APR_UEXECUTE) != 0;
> > > > >  
> > > > 
> > > > Huh? Whenever I see conditionals cast to (long) I get
> > > > suspicious. 
> > > 
> > > These are all cases where an integer is stored in a pointer; it's safe 
> > > to assume that a long will fit in a pointer on all platforms which httpd 
> > > runs on as a practical consideration, and using a cast to long rather 
> > > than a cast to int will avoid compiler warnings on LP64 platforms.
> > > 
> > 
> > The above explanation worries me to no end. :) Certainly a union could be
> > used to avoid this.
> 
> Well there are solutions, sure, not sure how a union would help here.  
> Try it and see... I usually end up deciding these issues are so marginal 
> that there's some better way to spend time fixing real bugs than to try 
> and break code which works perfectly well ;)
> 

At the very last, if we are "assuming" behavior which is
specifically implementation dependent, then a test during
configure time that ensures sizeof(void *) <= sizeof(long)
makes sense.

There is no room, IMO, for silent hidden assumptions
in httpd.

-- 
=======================================================================
 Jim Jagielski   [|]   jim@jaguNET.com   [|]   http://www.jaguNET.com/
           "If you can dodge a wrench, you can dodge a ball."