kconfig: qconf: compile moc object separately

Currently, qconf.moc is included from qconf.cc but they can be compiled
independently.

When you modify qconf.cc, qconf.moc does not need recompiling.

Rename qconf.moc to qconf-moc.cc, and split it out as an independent
compilation unit.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/.gitignore

 # SPDX-License-Identifier: GPL-2.0-only
-*.moc
+/qconf-moc.cc
 *conf-cfg
 
 #

scripts/kconfig/Makefile

@@ -181,21 +181,22 @@ $(addprefix $(obj)/, mconf.o $(lxdialog)): $(obj)/mconf-cfg
 
 # qconf: Used for the xconfig target based on Qt
 hostprogs	+= qconf
-qconf-cxxobjs	:= qconf.o
+qconf-cxxobjs	:= qconf.o qconf-moc.o
 qconf-objs	:= images.o $(common-objs)
 
 HOSTLDLIBS_qconf	= $(shell . $(obj)/qconf-cfg && echo $$libs)
 HOSTCXXFLAGS_qconf.o	= $(shell . $(obj)/qconf-cfg && echo $$cflags)
+HOSTCXXFLAGS_qconf-moc.o = $(shell . $(obj)/qconf-cfg && echo $$cflags)
 
-$(obj)/qconf.o: $(obj)/qconf-cfg $(obj)/qconf.moc
+$(obj)/qconf.o: $(obj)/qconf-cfg
 
 quiet_cmd_moc = MOC     $@
-      cmd_moc = $(shell . $(obj)/qconf-cfg && echo $$moc) -i $< -o $@
+      cmd_moc = $(shell . $(obj)/qconf-cfg && echo $$moc) $< -o $@
 
-$(obj)/%.moc: $(src)/%.h $(obj)/qconf-cfg FORCE
+$(obj)/qconf-moc.cc: $(src)/qconf.h $(obj)/qconf-cfg FORCE
 	$(call if_changed,moc)
 
-targets += qconf.moc
+targets += qconf-moc.cc
 
 # gconf: Used for the gconfig target based on GTK+
 hostprogs	+= gconf

scripts/kconfig/qconf.cc

@@ -23,7 +23,6 @@
 #include "lkc.h"
 #include "qconf.h"
 
-#include "qconf.moc"
 #include "images.h"