Re: [Qemu-devel] [PATCH v6 05/27] qapi: include osdep.h in type headers

[Markus Armbruster]

Marc-André Lureau <address@hidden> writes:

> Hi
>
> On Tue, Dec 4, 2018 at 7:23 PM Markus Armbruster <address@hidden> wrote:
>>
>> Marc-André Lureau <address@hidden> writes:
>>
>> > Now that the schema can be configured, it is crucial that all types
>> > are configured the same. Make sure config-host.h is included, so
>> > build-sys tracks the dependency and rebuilds the types, by including
>> > osdep.h first.
>> >
>> > Signed-off-by: Marc-André Lureau <address@hidden>
>> > ---
>> >  scripts/qapi/types.py | 1 +
>> >  1 file changed, 1 insertion(+)
>> >
>> > diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
>> > index fd7808103c..91f87d0b8f 100644
>> > --- a/scripts/qapi/types.py
>> > +++ b/scripts/qapi/types.py
>> > @@ -201,6 +201,7 @@ class 
>> > QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
>> >  ''',
>> >                                        types=types, visit=visit))
>> >          self._genh.preamble_add(mcgen('''
>> > +#include "qemu/osdep.h"
>> >  #include "qapi/qapi-builtin-types.h"
>> >  '''))
>>
>> No.  Every .c must include qemu/osdep.h first.  No .h may include it.
>> We clean this up periodically.  scripts/clean-includes can help with
>> that.  We currently have a few offenders in the tree.
>
> Ok, I don't know the reason an internal header couldn't include osdep,
> could you explain?
>
> I think we can replace osdep.h by config-host.h for the same result,
> I'd have to check.

Quote ./HACKING:

1.2. Include directives

Order include directives as follows:

#include "qemu/osdep.h"  /* Always first... */
#include <...>           /* then system headers... */
#include "..."           /* and finally QEMU headers. */

The "qemu/osdep.h" header contains preprocessor macros that affect the behavior
of core system headers like <stdint.h>.  It must be the first include so that
core system headers included by external libraries get the preprocessor macros
that QEMU depends on.

Do not include "qemu/osdep.h" from header files since the .c file will have
already included it.