Proof positive the "signedness of char *" warning is useless.

Jason Schoon floydpink at gmail.com
Thu Dec 1 16:14:33 UTC 2005


This is the best solution I have heard thus far.  This is the path we have
always taken on our embedded platforms as well.

On 12/1/05, Rob Landley <rob at landley.net> wrote:
>
> On Wednesday 30 November 2005 17:41, Chuck Meade wrote:
> > Yeah that one can't be warned against by the compiler.  It is just an
> > error -- assuming the user wasn't purposely aiming for this behavior.
> >
> > In other words, if they wrote the above code using a signed char,
> > and did not handle (or prevent) the case where the MSB would get set,
> > and they are surprised when the comparison gives unexpected results,
> > then the error is on their part.
>
> Ok, so some of the most common _real_ errors aren't caught by this stupid
> warning (and can't be), so even herculean efforts to clean up the noise
> wouldn't actually be _useful_.
>
> But what _might_ be useful is -funsigned-char added to our makefile.  (The
> argument about this producing more or less efficient code still sounds
> like
> handwaving at this point.  I'm more concerned about whether or not our
> code
> is _right_.  We declare unsigned char in a lot of places already, if that
> affected the binary size I think we would have noticed by now.  As for
> efficiency, either the library has assembly optimized versions of strcmp()
> and friends, or it doesn't.)
>
> *rummage* *rummage*...
>
> I just set EXTRA_CFLAGS_OPTIONS to -funsigned-char and did a "make clean
> &&
> make" and it seems to have built (on ubuntu with gcc 3.3) just fine.  I'll
> try it on gcc 4.0 in a bit and see if it makes a difference to the darn
> warnings, and if so I'll patch Rules.mak and check it in to see what
> breaks
> for other people.
>
> I'm going to try to put together a -pre2 for release wednesday the
> 7th.  It
> probably won't have all the bugs from the list fixed, but I hope to at
> least
> have 'em triaged into "must fix for 1.1", "would be nice", and "not a 1.1
> issue."
>
> > Chuck
>
> Rob
> --
> Steve Ballmer: Innovation!  Inigo Montoya: You keep using that word.
> I do not think it means what you think it means.
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