Re: Artificially target-dependend compiles

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/5/21 14:45, Markus Armbruster wrote:
> Moving these definitions to machine-target.json moves the generated C
> from qapi/qapi-*-machine.[ch] to qapi/qapi-*-machine-target.[ch], where
> CONFIG_ACPI_VMGENID is okay.  It also makes qmp_query_vm_generation_id()
> target-dependent: it needs qapi/qapi-commands-machine-target.h.

If I understand correctly, the problem that 
qapi-commands-machine-target.h is target-dependent, because it uses 
"#ifdef CONFIG_ACPI_VMGENID" around the prototype?

On one hand, the "#ifdef" is unnecessary: the prototype does not depend 
on anything target-specific.  Removing it will avoid the 
target-dependence.  On the other hand, the "#ifdef" has a defensive 
purpose, in that an unnecessary definition (such as the one currently in 
the stub) will fail due to the implicit definition of 
qmp_query_vm_generation_id().

> Have you seen similar artificial target-dependence elsewhere?

I can't think of a specific example, but it does ring some bells.

Paolo