Re: [patch 5/5] Remove function.h dependency on hard-reg-set.

[Richard Biener <richard dot guenther at gmail dot com>]

On Tue, Jun 16, 2015 at 7:21 PM, Andrew MacLeod <amacleod@redhat.com> wrote:
> function.h defines struct rtl_data which is used for generating rtl. In
> particular, it defines an instance 'crtl' which for generating rtl appears
> analagous to cfun for gimple and trees.
>
> That is the only reason function.h requires hard-reg-set.h.  I tried a lot
> of variations.. like moving it into rtl.h, moving it into its own file,  and
> eventually settled on putting it in emit-rtl.h   In fact, it turns out
> emit-rtl.c is where the instance is actually declared.... function.h was
> simply providing a reference to it so someone didn't have to include
> emit-rtl I guess.  BUt then emit-rtl.h has most of the inline functions for
> accessing it.  There appears to be some historical reason for not wanting to
> include emit-rtl.h? Im not sure.
>
> Placing it in rtl.h appeared to be someones original plan if I read the
> various comments correctly. I tried that in many variations, but the
> intricate dance between the generators and rtl.h and how to detect who
> really needs it made it ugly, and I couldn't find any decent way to do it.
> Putting it in Its own file worked OK, but it required that file to be
> incliuded a lot of other places.  Thats still an option however.    Given
> the changes to put it into emit-rtl.h are so simple in comparison, and all
> the routines that manipulate are already declared there, it seems like the
> most appropriate place.
>
> there were also 2 function prototypes in function.h which were guarded by
> #ifdef RTX_CODE....  I remove that and let the prototypes be defined.  I'm
> not sure why they were guarded... they aren't called if there is no RTX_CODE
> defined anyway... lots of other parameter lists refer to 'rtx' and there's
> no compilation error if the prototypes is produced but not used.
>
> By doing that, there is no longer any ordering requirement that function.h
> be included before rtl.h, and no dependency.  And of course, function.h no
> longer requires hard-reg-set.h etiher.
>
> bootstraps on x86_64-unknown-linux-gnu with no new regressions, and also
> compiles stage 1 for all the targets in config-list.mk.

Ok.

Thanks,
Richard.

> OK for trunk?
> Andrew