headers.chk failing under certain circumstances.

[Andrew Cooper <andrew.cooper3@citrix.com>]

Hello,

Back in changeset 19772:aaab04808ee7, you introduced headers.chk to
check the header files for ansi conformance.

To fix the current 32/64bit interaction errors with the kexec
hypercalls, I need to use uint64_aligned_t as a datatype.  For the
normal compile, this is all fine, but as header.chk does not define
__XEN__ or __XEN_TOOLS__, the declaration of uint64_aligned_t is never
made, leading to the check failing.

There are other hypercall interfaces which use these datatypes: domctl,
sysctl and hvm_op, but these header files are explicitly filtered out
from the prerequisites for header.chk.  Given that uint64_aligned_t is a
sensible datatype to be using with the hypercall interface, fixing the
check seems to be the correct solution.

In your oppinion, which is the best course of action? To define __XEN__
or __XEN_TOOLS__ as part of the check (this throws up other errors as
part of the check process, suggesting that the header files are hiding
ansi non-conformance in certain blocks), or dont predicate the
definition of uint64_aligned_t on the presence of the above defines?

In addition, why are certain header files excluded from being checked? 
Does this imply that then should be fixed up to be ansi conformant as well?

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com