Re: [PATCH] eliminate compile warnings

From: Thorsten Kranzkowski (
Date: Fri Nov 08 2002 - 02:38:45 EST

On Thu, Nov 07, 2002 at 05:33:49PM -0800, Richard Henderson wrote:
> As for the patch itself, it's not correct. At a glance,
> > addr = arch_get_unmapped_area_1 (PAGE_ALIGN(addr), len, limit);
> > - if (addr != -ENOMEM)
> > + if (addr != (unsigned) -ENOMEM)
> addr is unsigned long. If you truncate -ENOMEM to 32-bits, it will
> never match. There appears to be much more int/long confusion later.

I will give my patch another thought and I will feed it to you in smaller
pieces and with comments.

> You have to be /exceedingly/ careful to fix these warnings without
> introducing new bugs. If you change the type of a variable, you
> have to examine each and every use of the variable to determine if
> the semantics are unchanged. If you add a cast, you have to be sure
> that you cast to a type of the correct width. If you're adding lots
> of casts, you should think about changing the type of one or more
> variables.

Generally I'm aware of this - maybe a case of more coffee needed :)

> It's enough to make me wish we had -Wno-sign-compare in CFLAGS by
> default for the nonce. Which, incidentally, is what I've been doing
> for my own builds.
> There's absolutely no way I'm going to apply a jumbo patch that
> changes hundreds of these at once. If you still want to fix these,
> then you'll need to send them one at a time and include analysis of
> why each change is correct.

Will do.

Thanks for your time.


| Thorsten Kranzkowski        Internet:                      |
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