Re: any value to "NORET_TYPE" macro?

On 5/22/07, Robert P. J. Day <rpjday@xxxxxxxxxxxxxx> wrote:
On Tue, 22 May 2007, John Anthony Kazos Jr. wrote:

> > given that:
> >
> > $ grep -r "define.*NORET_TYPE" *
> > include/linux/ext4_fs.h:# define NORET_TYPE /**/
> > include/linux/linkage.h:#define NORET_TYPE /**/
> > include/linux/ext3_fs.h:# define NORET_TYPE /**/
> > $
> >
> > is there any obvious value to the 30 or so uses of that macro
> > sprinkled throughout the tree?
>
> Since it evaluates to absolutely empty code during pre-processing,
> there is no obvious value. The question is whether there is some odd
> hackish non-obvious value, I'd expect. (I'd also expect that to be
> another "no".)
>
> If something that evaluates to nothingness ("There was nothing
> left...not even a hole!") actually does anything, then somebody in
> the standards-compilers-users pipeline needs to be violently beaten
> for stupidity.


actually, one of the folks on the KJ list found this:

http://www.ussg.iu.edu/hypermail/linux/kernel/9605/1957.html

which speaks thusly:

...
-#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
-# define NORET_TYPE __volatile__
-# define ATTRIB_NORET /**/
-# define NORET_AND /**/
-#else
# define NORET_TYPE /**/
# define ATTRIB_NORET __attribute__((noreturn))
# define NORET_AND noreturn,
-#endif
...

so it looks like a thoroughly obsolete macro which can be tossed.
i'll make the patch and test it.

AFAICT, NORET_TYPE must've been introduced to silence gcc _warnings_,
and not do actually do anything useful that affects functionality in any way.
So the way to "test" your patch would be to see if there is any increase /
decrease in the number of *warnings* blurted out by gcc during kernel build
(best would be to build with various gcc versions on various platforms :-)

Satyam
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