Index: dnsmasq-2.72/Makefile
===================================================================
--- dnsmasq-2.72.orig/Makefile	2014-12-30 19:46:10.484921940 +0800
+++ dnsmasq-2.72/Makefile	2014-12-30 19:56:39.712926794 +0800
@@ -74,6 +74,10 @@
 hdrs = dnsmasq.h config.h dhcp-protocol.h dhcp6-protocol.h \
        dns-protocol.h radv-protocol.h ip6addr.h
 
+COPT_CONF = $(top)/.copt_$(shell $(CC) -DDNSMASQ_COMPILE_OPTS $(COPTS) -E $(top)/$(SRC)/config.h | \
+			( md5sum 2>/dev/null || md5 ) | cut -f 1 -d ' ')
+COPT_CONF_WILD = $(top)/.copt_*
+
 all : $(BUILDDIR)
 	@cd $(BUILDDIR) && $(MAKE) \
  top="$(top)" \
@@ -83,7 +87,7 @@
 
 mostly_clean :
 	rm -f $(BUILDDIR)/*.mo $(BUILDDIR)/*.pot 
-	rm -f $(BUILDDIR)/.configured $(BUILDDIR)/*.o $(BUILDDIR)/dnsmasq.a $(BUILDDIR)/dnsmasq 
+	rm -f $(BUILDDIR)/$(COPT_CONF_WILD) $(BUILDDIR)/*.o $(BUILDDIR)/dnsmasq.a $(BUILDDIR)/dnsmasq
 
 clean : mostly_clean
 	rm -f $(BUILDDIR)/dnsmasq_baseline
@@ -139,7 +143,7 @@
 
 # rules below are targets in recusive makes with cwd=$(BUILDDIR)
 
-.configured: $(hdrs)
+$(COPT_CONF): $(hdrs)
 	@rm -f *.o
 	@touch $@
 
@@ -149,7 +153,7 @@
 .c.o:
 	$(CC) $(CFLAGS) $(COPTS) $(i18n) $(build_cflags) $(RPM_OPT_FLAGS) -c $<	
 
-dnsmasq : .configured $(hdrs) $(objs)
+dnsmasq : $(COPT_CONF) $(hdrs) $(objs)
 	$(CC) $(LDFLAGS) -o $@ $(objs) $(build_libs) $(LIBS) 
 
 dnsmasq.pot : $(objs:.o=.c) $(hdrs)