perf build: Add gtk objects building

Move the gtk objects building under build framework.

Add new gtk build object so it's separated from the rest of the code and
could be librarized.

Signed-off-by: Jiri Olsa <[e-mail]>
Tested-by: Sukadev Bhattiprolu <[e-mail]>
Tested-by: Will Deacon <[e-mail]>
Cc: Alexis Berlemont <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Corey Ashford <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Build

···
 libperf-y += util/
 libperf-y += arch/
 libperf-y += ui/
+
+gtk-y += ui/gtk/

tools/perf/Makefile.perf

···
 
 ifndef NO_GTK2
   ALL_PROGRAMS += $(OUTPUT)libperf-gtk.so
-
-  GTK_OBJS += $(OUTPUT)ui/gtk/browser.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/hists.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/setup.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/util.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/helpline.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/progress.o
-  GTK_OBJS += $(OUTPUT)ui/gtk/annotate.o
+  GTK_IN := $(OUTPUT)gtk-in.o
 
 install-gtk: $(OUTPUT)libperf-gtk.so
 	$(call QUIET_INSTALL, 'GTK UI') \
···
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(OUTPUT)perf.o \
                $(BUILTIN_OBJS) $(PERF_IN) $(LIBS) -o $@
 
-$(GTK_OBJS): $(OUTPUT)%.o: %.c $(LIB_H)
-	$(QUIET_CC)$(CC) -o $@ -c -fPIC $(CFLAGS) $(GTK_CFLAGS) $<
+$(GTK_IN): FORCE
+	@$(MAKE) $(build)=gtk
 
-$(OUTPUT)libperf-gtk.so: $(GTK_OBJS) $(PERFLIBS)
+$(OUTPUT)libperf-gtk.so: $(GTK_IN) $(PERFLIBS)
 	$(QUIET_LINK)$(CC) -o $@ -shared $(LDFLAGS) $(filter %.o,$^) $(GTK_LIBS)
 
 $(OUTPUT)common-cmds.h: util/generate-cmdlist.sh command-list.txt
···
 	@$(MAKE) -C config/feature-checks clean >/dev/null
 
 clean: $(LIBTRACEEVENT)-clean $(LIBAPIKFS)-clean config-clean
-	$(call QUIET_CLEAN, core-objs)  $(RM) $(LIB_OBJS) $(BUILTIN_OBJS) $(LIB_FILE) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf.o $(LANG_BINDINGS) $(GTK_OBJS)
+	$(call QUIET_CLEAN, core-objs)  $(RM) $(LIB_OBJS) $(BUILTIN_OBJS) $(LIB_FILE) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf.o $(LANG_BINDINGS)
 	@find . -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
 	@$(RM) .config-detected
 	$(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 perf-read-vdsox32

tools/perf/config/Makefile

···
 $(call detected_var,prefix_SQ)
 $(call detected_var,perfexecdir_SQ)
 $(call detected_var,LIBDIR)
+$(call detected_var,GTK_CFLAGS)

tools/perf/ui/gtk/Build

···
+CFLAGS_gtk += -fPIC $(GTK_CFLAGS)
+
+gtk-y += browser.o
+gtk-y += hists.o
+gtk-y += setup.o
+gtk-y += util.o
+gtk-y += helpline.o
+gtk-y += progress.o
+gtk-y += annotate.o