Re: [Qemu-devel] [PATCH] Error: Fix build when qemu-common.h is not included

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu, 07 Jul 2011 18:50:28 +0200
Stefan Weil <weil@mail.berlios.de> wrote:

> Am 07.07.2011 18:17, schrieb Michael Roth:
> > On 07/07/2011 11:02 AM, Luiz Capitulino wrote:
> >> Commit e4ea5e2d0e0e4c5188ab45b66f3195062ae059dc added the use of
> >> the macro GCC_FMT_ATTR to error.h, however qemu-common.h is not
> >> included by error.h
> >>
> >> This will cause a build error when files including error.h
> >> don't include qemu-common.h. Not an issue today because the only
> >> file including it is json-parser.h and it does include
> >> qemu-common.h, but let's fix it.
> >>
> >> Signed-off-by: Luiz Capitulino<lcapitulino@redhat.com>
> >> ---
> >>   error.h |    2 +-
> >>   1 files changed, 1 insertions(+), 1 deletions(-)
> 
> The same argument could be applied to more QEMU *.h files
> which also work only after qemu-common.h. Otherwise, including
> qemu-common.h in *.c files would rarely be needed.
> 
> As far as I remember, the *.h files used to be more self-contained
> some years ago, but then the strategy changed and central files
> like qemu-common.h were introduced.
> 
> I personally prefer self-contained include files like error.h
> (before my patch and after your patch), but I'm afraid that
> the QEMU way is different.

The current way is broken. Some qemu header files are a complete mess.
qemu-common.h and sysemu.h are good examples. They include too many
things, if you change them a lot of code will be recompiled.

I could make the problem less worse by moving all compiler related
macros to a compiler.h header and then include it in qemu-common.h
and error.h. This way error.h won't be affected, although the real
problem will remain unsolved.