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From: Martin Str|mberg <ams AT ludd DOT luth DOT se>
Message-Id: <200112251716.SAA11347@father.ludd.luth.se>
Subject: Re: gcc 3.03 and libc sources
In-Reply-To: <Pine.SUN.3.91.1011225131954.5289B-100000@is> from Eli Zaretskii at "Dec 25, 2001 01:31:51 pm"
To: djgpp-workers AT delorie DOT com
Date: Tue, 25 Dec 2001 18:16:39 +0100 (MET)
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According to Eli Zaretskii:
> 
> On Tue, 25 Dec 2001, Martin Str|mberg wrote:
> 
> > -  *decpt = dot ? dot - s : strlen (s);
> > +  *decpt = dot ? dot - s : (ssize_t)strlen (s);
> 
> I don't understand why did you cast to ssize_t here.  I'd say either cast 
> to int or to ptrdiff_t.  The latter is more accurate, since "dot -s" is a 
> difference between two pointers; but because gcc wants a signed type, int 
> should be okay as well.

I thought ssize_t is the signed counterpart of size_t and as
strlen()'s return type is size_t I made that change. Now I see that
ssize_t isn't standard but ptrdiff_t is, so I'll change that.

> I still have no idea why does gcc complain here.  What's wrong about 
> having an expression whose result could be either signed or unsigned?  I 
> think it's worth a bug report nonetheless, if only to hear an 
> explanation from the maintainers.

I'm using -Wsign-compare, which is the option that produces this
warning. I assume this makes gcc complain about implicit casting. So
if we have a "bool ? signed : unsigned" expression, one of signed or
unsigned must be casted.


Right,

						MartinS