[xen master] build: adjust include/xen/compile.h generation

[patchbot@xxxxxxx]

commit 299deb9dd93e5aae2f3b24ec001214458077a185
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Jan 14 11:03:03 2022 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Jan 14 11:03:03 2022 +0100

    build: adjust include/xen/compile.h generation
    
    Prior to 19427e439e01 ("build: generate "include/xen/compile.h" with
    if_changed") running "make install-xen" as root would not have printed
    the banner under normal circumstances. Its printing would instead have
    indicated that something was wrong (or during a normal build the lack
    of printing would do so).
    
    Further aforementioned change had another undesirable effect, which I
    didn't notice during review: Originally compile.h would have been
    re-generated (and final binaries re-linked) when its dependencies were
    updated after an earlier build. This is no longer the case now, which
    means that if some other file also was updated, then the re-build done
    during "make install-xen" would happen with a stale compile.h (as its
    updating is suppressed in this case).
    
    Restore the earlier behavior for both aspects.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
 xen/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/Makefile b/xen/Makefile
index dc6bdc44c7..1e10d9f680 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -424,6 +424,7 @@ targets += .banner
 quiet_cmd_compile.h = UPD     $@
 define cmd_compile.h
     if [ ! -r $@ -o -O $@ ]; then \
+       cat .banner; \
        sed -e 's/@@date@@/$(XEN_BUILD_DATE)/g' \
            -e 's/@@time@@/$(XEN_BUILD_TIME)/g' \
            -e 's/@@whoami@@/$(XEN_WHOAMI)/g' \
@@ -441,7 +442,7 @@ define cmd_compile.h
 endef
 
 include/xen/compile.h: include/xen/compile.h.in .banner FORCE
-       @cat .banner
+       $(if $(filter-out FORCE,$?),$(Q)rm -fv $@)
        $(call if_changed,compile.h)
 
 targets += include/xen/compile.h
--
generated by git-patchbot for /home/xen/git/xen.git#master