Re: toupper and warnings

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2021-05-06 02:26, Greg A. Woods wrote:
> At Wed, 5 May 2021 20:33:30 -0000 (UTC), christos%astron.com@localhost (Christos Zoulas) wrote:
> Subject: Re: toupper and warnings
> > gcc hides warnings from system headers by default (my guess is because
> > the Linux system headers have a concealed firearms license).
> >
> > Our bsd.sys.mk turns it on... Try gcc -Wall -Wsystem-headers
>
> Does that really make the difference?
>
> (I can't quickly test it at the moment as I've fixed my test system such
> that I don't ever get these warnings from the ctype macros.  I.e. I went
> the other way and chose to make my implementation's "undefined
> behaviour" to be to behave as conservative as possible and allow the
> caller to use these macros in the traditional naive way without fear and
> without noisy warnings from picky compilers when char is signed.)

I'm not sure I understand why you'd get a warning in the first place.
toupper should take an int as input. Which is signed.
If you pass in a char, it should always fit and work.
Why should you get a warning?

  Johnny

--
Johnny Billquist                  || "I'm on a bus
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