include: fix build without C++ compiler installed

The rule for headers++.chk wants to move headers++.chk.new to the
designated target, which means we have to create that file in the first
place.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Julien Grall <julien.grall@arm.com>

diff --git a/xen/include/Makefile b/xen/include/Makefile
index cd271dde0a730c0bee8dd00360caa0f72a2fb159..3a6fa0fd59fdd3112edb3f4f5a276c3086747617 100644 (file)
--- a/xen/include/Makefile
+++ b/xen/include/Makefile
@@ -120,7 +120,10 @@ headers99.chk: $(PUBLIC_C99_HEADERS) Makefile
 
 headers++.chk: $(PUBLIC_HEADERS) Makefile
        rm -f $@.new
-       $(CXX) -v >/dev/null 2>&1 || exit 0;                                  \
+       if ! $(CXX) -v >/dev/null 2>&1; then                                  \
+           touch $@.new;                                                     \
+           exit 0;                                                           \
+       fi;                                                                   \
        $(foreach i, $(filter %.h,$^),                                        \
            echo "#include "\"$(i)\"                                          \
            | $(CXX) -x c++ -std=gnu++98 -Wall -Werror -D__XEN_TOOLS__        \