Re: [google]: initialize language field for clone function struct

[Richard Guenther <richard.guenther@gmail.com>]

On Wed, May 4, 2011 at 12:00 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> Umm, I think most of them (if not all) are just bogus.  If a FE doesn't
>> want to fold some stuff when at global scope it should not call fold.
>
> That isn't so easy because fold is invoked on sizes of types by stor-layout.c
> and these sizes can be variable (at least in Ada).  So I think that the calls
> to the hook are still needed.  But:
>  1) The -1 thing should go and the hook return boolean.  The prerequisite is
> to tidy up variable_size,
>  2) I think that the GIMPLE hook can return 0 unconditionally.
>
>> But I'm not sure that is actually what it tries to do ... and the existing
>> checks are far from consistently spread out in fold-const.c ...
>
> It prevents save_expr from being called at global level, since you cannot
> create SAVE_EXPRs outside functions.  Likewise in variable_size.

I see several places in fold-const.c that are not properly guarded then.
But anyway, if it is supposed to protect SAVE_EXPRs then I'd have expected
save_expr to contain that check and possibly return NULL if it can't save.

And I'm not sure you can't do SAVE_EXPRs outside of functions - you
could simply emit global temporaries.

Richard.

> --
> Eric Botcazou
>