Re: [Qemu-devel] [PATCH 26/67] cpu: replace command line flags with preprocessor

[Michael S. Tsirkin]

On Fri, May 04, 2018 at 02:35:49AM +0200, Thomas Huth wrote:
> On 03.05.2018 21:51, Michael S. Tsirkin wrote:
> > Each target is currently built with a different set of include
> > directories, this is what makes it possible to pull in a separate copy
> > of cpu.h depending on the target.
> > 
> > Replace with per-target ifdefs which are easier to understand.
> > 
> > Signed-off-by: Michael S. Tsirkin <address@hidden>
> > ---
> >  include/cpu.h | 2 ++
> >  1 file changed, 2 insertions(+)
> >  create mode 100644 include/cpu.h
> > 
> > diff --git a/include/cpu.h b/include/cpu.h
> > new file mode 100644
> > index 0000000..b18f163
> > --- /dev/null
> > +++ b/include/cpu.h
> > @@ -0,0 +1,2 @@
> > +#include "target-dir.h"
> > +#include TARGET_DIR(cpu.h)
> 
> That's a *bad* idea. As far as I can see, this way, cpu.h is now
> suddenly available to generic, non-target specific code. The headers in
> target/* are "hidden" by purpose for all code that gets compiled via
> common-obj-y and if you now make it available for everybody again, we'll
> end up in ugly situation where common code might have been compiled with
> target specific defines from target specific headers... Please don't do
> that!
> 
>  Thomas

Are you sure that is the case? TARGET_XXX defines really shouldn't be
set for non-target specific code.

-- 
MST