Patch series available in this git branch:
https://xenbits.xen.org/git-http/people/aperard/xen-unstable.git br.build-system-xen-include-rework-v2

v2:
- new patch [1/4] to fix issue with command line that can be way too long
- other small changes, and reorder patches

Hi,

This patch series is about 2 improvement. First one is to use $(if_changed, )
in "include/Makefile" to make the generation of the compat headers less verbose
and to have the command line part of the decision to rebuild the headers.
Second one is to replace one slow script by a much faster one, and save time
when generating the headers.

There's some number here:
    https://lore.kernel.org/xen-devel/Yp3%2F%2Fc%2FCAcwLHCvi@perard.uk.xensource.com/

    On my machine when doing a full build [of the hypervisor], with `ccache`
    enabled, it saves about 1.17 seconds (out of ~17s), and without ccache, it
    saves about 2.0 seconds (out of ~37s).

Thanks.

Anthony PERARD (4):
  build,include: rework shell script for headers++.chk
  build: remove auto.conf prerequisite from compat/xlat.h target
  build: set PERL
  build: replace get-fields.sh by a perl script

 xen/Makefile                    |   1 +
 xen/include/Makefile            |  25 +-
 README                          |   1 +
 xen/tools/compat-xlat-header.pl | 539 ++++++++++++++++++++++++++++++++
 xen/tools/get-fields.sh         | 528 -------------------------------
 5 files changed, 557 insertions(+), 537 deletions(-)
 create mode 100755 xen/tools/compat-xlat-header.pl
 delete mode 100644 xen/tools/get-fields.sh

-- 
Anthony PERARD