Re: [PATCH] Documentation: Explain a second alternative for multi-line macros.

[Randy Dunlap <randy.dunlap@oracle.com>]

Segher Boessenkool wrote:
> > > In this case, the second form
> > > should be used when the macro needs to return a value (and you can't
> > > use an inline function for whatever reason), whereas the first form
> > > should be used at all other times.
> >
> > that's a fair point, although it's certainly not the coding style
> > that's in play now.  for example,
> >
> >   #define setcc(cc) ({ \
> >     partial_status &= ~(SW_C0|SW_C1|SW_C2|SW_C3); \
> >     partial_status |= (cc) & (SW_C0|SW_C1|SW_C2|SW_C3); })
>
> This _does_ return a value though, bad example.

Where does it return a value?  I don't see any uses of it
in arch/i386/math-emu/* that use it as returning a value.

And with a small change to put it inside a do-while block
instead of ({ ... }), it at least builds cleanly.
I expected some complaints.

--
~Randy
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/