Re: RFC: #pragma optimization_level

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On Apr 1, 2005, at 8:40 PM, Dale Johannesen wrote:

> On Apr 1, 2005, at 1:38 PM, Geoffrey Keating wrote:
> > Dale Johannesen <dalej@apple.com> writes:
> >
> > > - As a first cut I intend to allow only -O[0123s] to be specified in
> > > the pragma, as suggested by Geert Bosch.  I don't think there's any
> > > reason this couldn't be extended to single flags.
> >
> > How do you plan to deal with preprocessor macros?  On some systems,
> > like Linux and possibly even Darwin, the system headers will define
> > some macros or inline functions differently depending on the setting
> > of __OPTIMIZE__ and __OPTIMIZE_SIZE__ and so on.
>
> I wasn't aware of this.  It should be easy enough to keep track of the 
> pragmas
> as seen so these symbols have the right value during preprocessing.
> But that won't work in combination with inlining, because the saved 
> form
> used for inlining is after preprocessing is done; I don't see an 
> approach
> for that problem that doesn't involve major surgery.  I'm inclined to 
> just
> let it work in the natural way and document it.

One more note, the C++ front-end does lexing all at once which means 
#pragma is
not processed until after all of the preprocessing is done. So I don't 
know
how this will work with the C++ front-end.

Thanks,
Andrew Pinski