Re: [Qemu-devel] [PATCH for-2.7 00/49] NEED_CPU_H / cpu.h / hw/hw.h cleanups

[Markus Armbruster]

Paolo Bonzini  writes:

> (CCs only on cover letter due to huge series).
>
> I am sending this now because of vacation coming soon (yay!).
> This series removes usage of NEED_CPU_H from several central
> include files in QEMU, most notably hw/hw.h and qemu-common.h.
> Definitions conditional on NEED_CPU_H remain only in disas/disas.h,
> exec/gdbstub.h, exec/helper-head.h and exec/log.h.
>
> The interesting patches are interspersed with other miscellaenous
> cleanups that I won't really dwell on in the cover letter.  Most
> of them are just making indirect inclusions explicit.
>
> Patches 5 to 27 make sure that target-independent code can access
> QOM objects for the CPU through an opaque type.  This is useful
> because often target-independent code uses a target-specific header
> file that happens to use pointers to ARMCPU* or similar.  The
> target-independent code itself does not use the pointed-to object,
> but the very presenece of the ARMCPU* name means that all users of
> that header have to bring in cpu.h.  By providing the opaque type,
> a much smaller API can be exposed to all these users in hw/.
>
> Patches 34 to 37 remove NEED_CPU_H from hw/hw.h, exec/memory.h
> and exec/cpu-common.h.
>
> Patches 38 and 39 remove two nested inclusions from qemu-common.h.
> This should make Markus's patch to remove unnecessary qemu-common.h
> inclusions even more effective.
>
> Patches 42 and 43 disentangle qemu-common.h and cpu.h, so that all
> users of the latter have to be explicit.  This has the biggest
> effect on reducing include pollution (the next offender is now
> exec/cpu-common.h).
>
> Patches 46 to 50 remove more nested inclusions, and especially:
> 1) the inclusion of the (TCG-specific) exec-all.h header from
> cpu.h, so that non-TCG functions cannot anymore creep into
> exec-all.h; 2) indirect qemu-common.h inclusion in hw/hw.h.
>
> At the end, hw/hw.h includes 13 fewer headers indirectly compared
> to before when NEED_CPU_H is not defined, and 27 fewer headers
> when NEED_CPU_H is defined.  This was found with the script of
> patch 1, which produces the following statistics:
>
> Compiled 3979 files | After: 4006 (nmi.o now built 
> per target)
> 3773 files include qemu-common.h| After: 3702 (-71)
> 1658 files include hw/hw.h  | After: 1589 (-69)
> 3101 files include cpu.h| After: 2337 (-764, -25%!)
> 3800 files include qapi-types.h | After: 3811 (+11, mostly from 
> nmi.c)
>  844 files include generated-tracers.h  | After: 844
> 1270 files include qapi/error.h | After: 1297 (+27, from nmi.c)
> 1996 files include block/aio.h  | After: 1647 (-349, -18%)
> 3544 files include qom/object.h | After: 3514 (-30)
> 3451 files include exec/memory.h| After: 3540 (+89, from indirect 
> inclusions)
> 3840 files include fpu/softfloat.h  | After: 3701 (-139)
> 3783 files include qemu/bswap.h | After: 3644 (-139)
> |
> osdep.h:| After: (adds exec/poison.h)
> linesbytes   files   source | linesbytes   files   source
> 174  49443   QEMU   | 226  52174   QEMU
> 17460440677  157 total  | 17512440950  158 total
> |
> qemu-common.h:  | After:
> linesbytes   files   source | linesbytes   files   source
> 7037 160007  14  QEMU   | 5919 132798  12  QEMU
> 24323595740  168 total  | 23205568531  166 total
> |
> hw/hw.h:| After:
> linesbytes   files   source | linesbytes   files   source
> 9714 228659  36  QEMU   | 8458 201740  24  QEMU
> 27052665298  192 total  | 25796638379  180 total
> |
> target-i386/cpu.h:  | After:
> linesbytes   files   source | linesbytes   files   source
> 11259270041  41  QEMU   | 10981263615  39  QEMU
> 28597706680  197 total  | 28319700254  195 total
> |
> hw/hw.h + NEED_CPU_H:   | After:
> linesbytes   files   source | linesbytes   files   source
> 12340294661  50  QEMU   | 8407 201467  23  QEMU
> 29678731300  206 total  | 25745638106  179 total
>
> The next objectives should be removing unnecessary inclusions from/of
> qemu-common.h (or delete it altogether) and exec/cpu-common.h.

I skimmed the whole series, and it all looks sane to me.

As your stats show, there's more work to do.  

Re: [Qemu-devel] [PATCH for-2.7 00/49] NEED_CPU_H / cpu.h / hw/hw.h cleanups

[Markus Armbruster]

Needs a rebase, but better delay rebasing until later, because this
stuff goes stale quickly.  What's your base commit?  Got a branch I can
pull?