Re: [PATCH] sparse: Make struct token::special signed

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2014-12-23 at 11:01 -0800, Linus Torvalds wrote:
> On Tue, Dec 23, 2014 at 5:16 AM, Rasmus Villemoes <rv@rasmusvillemoes.dk> wrote:
> > There doesn't seem to be any reason for the special member of struct
> > token to be unsigned; AFAICT it is only ever being directly compared
> > to explicit characters and the SPECIAL_* enum constants using ==, !=
> > and in a switch statement. Making it plain int avoids an annoying
> > warning from match_op in token.h when compiling with -Wsign-compare.
> 
> Please don't use -Wsign-cpmpare to make decisions about code.
> 
> "unsigned" is generally the much preferred type if there are no
> reasons for it to be signed. And -Wsign-compare on its own is not a
> reason, since it gives insane warnings for good code.
> 
> -Wsign-compare is basically a "you can walk through the warnings and
> see if any of them are actually valid" thing. It's not worth it in any
> other form. Trying to be sign-compare clean will result in actively
> *worse* code in some circumstances (ie pointless casts etc etc).

Additionally "compare with characters" trips another flag, chars are
unsigned by default on some archs :)

Cheers
Ben.

>                      Linus
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