Re: [Qemu-arm] [Qemu-devel] [PATCH 03/15] hw/ssi: Remove SSIBus from "qemu/typedefs.h"

[Markus Armbruster]

Philippe Mathieu-Daudé <address@hidden> writes:

> From: Philippe Mathieu-Daudé <address@hidden>
>
> There are only three files requiring this typedef, let them
> include "hw/ssi/ssi.h" directly to simplify "qemu/typedefs.h".
>
> To clean "qemu/typedefs.h", move the forward declaration
> to "hw/ssi/ssi.h".
>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> ---
>  hw/arm/strongarm.h      | 1 +
>  include/hw/arm/pxa.h    | 1 +
>  include/hw/ssi/pl022.h  | 1 +
>  include/hw/ssi/ssi.h    | 1 +
>  include/qemu/typedefs.h | 1 -
>  5 files changed, 4 insertions(+), 1 deletion(-)

When typedefs.h changes, we recompile the world, but it pretty much only
ever changes when new typedefs are added.  Thus, *keeping* a typedef
there is therefore pretty cheap.

Nevertheless, we shouldn't keep typedefs there without a real reason.
Being able to move one away without having to add any new #include
directives is a strong sign for "no real reason".  I like patches doing
that.

What I don't like is adding #include directives just so you can move
typedefs out of typedefs.h: it slows down the build.  Granted, the four
added by this patch are a drop in the bucket.  The point I'm trying to
make is typedefs.h's purpose: it's for avoiding #include directives.
Circular ones in particular, but others, too.