kbuild: add comment about grouped target
GNU Make commit 8c888d95f618 ("[SV 8297] Implement "grouped targets"
for explicit rules.") added the '&:' syntax.
I think '&:' is a perfect fit here, but we cannot use it any time
soon. Just add a TODO comment.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/Makefile b/Makefile
index 4697d7c..7863d2a 100644
--- a/Makefile
+++ b/Makefile
@@ -677,6 +677,7 @@
#
# This exploits the 'multi-target pattern rule' trick.
# The syncconfig should be executed only once to make all the targets.
+# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
%/auto.conf %/auto.conf.cmd: $(KCONFIG_CONFIG)
$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
else # !may-sync-config
