Re: [PATCH 02/12] remove some ifdef HAVE_cc0

[Trevor Saunders <tbsaunde@tbsaunde.org>]

On Thu, Apr 23, 2015 at 10:58:22AM +0100, Kyrill Tkachov wrote:
> 
> On 23/04/15 10:08, Richard Earnshaw wrote:
> >On 23/04/15 09:41, Kyrill Tkachov wrote:
> >>On 23/04/15 09:35, Richard Biener wrote:
> >>>On Thu, Apr 23, 2015 at 6:54 AM, Trevor Saunders <tbsaunde@tbsaunde.org> wrote:
> >>>>On Thu, Apr 23, 2015 at 04:27:59AM +0100, James Greenhalgh wrote:
> >>>>>On Tue, Apr 21, 2015 at 04:24:44PM +0100, Trevor Saunders wrote:
> >>>>>>On Tue, Apr 21, 2015 at 04:14:01PM +0200, Richard Biener wrote:
> >>>>>>>On Tue, Apr 21, 2015 at 3:24 PM,  <tbsaunde+gcc@tbsaunde.org> wrote:
> >>>>>>>>From: Trevor Saunders <tbsaunde+gcc@tbsaunde.org>
> >>>>>>>>
> >>>>>>>>gcc/ChangeLog:
> >>>>>>>>
> >>>>>>>>2015-04-21  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
> >>>>>>>>
> >>>>>>>>          * conditions.h: Define macros even if HAVE_cc0 is undefined.
> >>>>>>>>          * emit-rtl.c: Define functions even if HAVE_cc0 is undefined.
> >>>>>>>>          * final.c: Likewise.
> >>>>>>>>          * jump.c: Likewise.
> >>>>>>>>          * recog.c: Likewise.
> >>>>>>>>          * recog.h: Declare functions even when HAVE_cc0 is undefined.
> >>>>>>>>          * sched-deps.c (sched_analyze_2): Always compile case for cc0.
> >>>>>If I've counted right after the git bisect, this patch seems to break
> >>>>>the ARM buildi (arm-none-linux-gnueabihf):
> >>>>>
> >>>>>    In file included from insn-output.c:40:0:
> >>>>>    ..../gcc-src/gcc/conditions.h:112:0: error: "CC_STATUS_INIT" redefined [-Werror]
> >>>>>     #define CC_STATUS_INIT  \
> >>This is a warning-to-error from -Werror, so this came out during bootstrap
> >>rather than a cross-build, right?
> >>
> >>
> >>>>>     ^
> >>>>>    In file included from tm.h:35:0,
> >>>>>                     from insn-output.c:7:
> >>>>>    ..../gcc-src/gcc/config/arm/arm.h:2159:0: note: this is the location of the previous definition
> >>>>>     #define CC_STATUS_INIT \
> >>>>>     ^
> >>>>>
> >>>>>I guess the conditions.h definition wants wrapping in #ifndef - though a
> >>>>>quick grep suggests that ARM is the only target defining CC_STATUS_INIT
> >>>>>so lets CC the ARM maintainers and see what their preference is...
> >>>>Well, that seems pretty weird, but it looks intentional arm does this
> >>>>see http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00437.html
> >>>>
> >>>>Of course I now see final.c also defines a fall back, so maybe the right
> >>>>thing to do is wrap the conditions.h definition in #if HAVE_cc0, or
> >>>>maybe the final.c definition can go away? Right now I'm to tired to make
> >>>>a good decision about that.
> >>>>
> >>>>sorry about the bustage!
> >>>Looks like the best thing is to turn this into a target hook then?  Or move the
> >>>fallback/default to defaults.h

Given the macro has multiple definitions I guess ultimately it should
move to a target hook unless someone decides to rework the arm backend.
Till then the ifdef in conditions.h doesn't seem to bad (I may well work
on converting a bunch of stuff to target hooks in the somewhat near
future).

> >>Shall we revert this patch for now then to restore bootstrap?
> >>
> >Isn't the most constructive temporary fix to just wrap the definition in
> >conditions.h with #ifndef CC_STATUS_INIT?
> 
> Like this?
> Ok for trunk as a temporary fix?

sgtm, thanks!

Trev

> 
> Thanks,
> Kyrill
> 
> 2015-04-23  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
> 
>     * conditions.h (CC_STATUS_INIT): Gate on #ifndef CC_STATUS_INIT.
> >R.
> >
> >>Kyrill
> >>
> >>>Richard.
> >>>
> >>>>Trev
> >>>>
> >>>>
> >>>>>Thanks,
> >>>>>James
> 

> diff --git a/gcc/conditions.h b/gcc/conditions.h
> index 7cd1e1c..0bda9a4 100644
> --- a/gcc/conditions.h
> +++ b/gcc/conditions.h
> @@ -109,8 +109,10 @@ extern CC_STATUS cc_status;
>  /* This is how to initialize the variable cc_status.
>     final does this at appropriate moments.  */
>  
> +/* FIXME: We want to get rid of these ifndefs.  */
> +#ifndef CC_STATUS_INIT
>  #define CC_STATUS_INIT  \
>   (cc_status.flags = 0, cc_status.value1 = 0, cc_status.value2 = 0,  \
>    CC_STATUS_MDEP_INIT)
> -
> +#endif
>  #endif /* GCC_CONDITIONS_H */