make: Use generic build engine for libcriu.so

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makefile

@@ -126,12 +126,9 @@ ifeq ($(GCOV),1)
 %.o $(PROGRAM): override CFLAGS += --coverage
 endif
 
-all: config pie $(VERSION_HEADER) lib
+all: config pie $(VERSION_HEADER) $(CRIU-LIB)
 	$(Q) $(MAKE) $(PROGRAM)
 
-lib: $(VERSION_HEADER)
-	$(Q) $(MAKE) -C lib all
-
 protobuf/%::
 	$(Q) $(MAKE) $(build)=protobuf $@
 protobuf:
@@ -152,6 +149,11 @@ pie: arch/$(ARCH)
 built-in.o: $(VERSION_HEADER) pie
 	$(Q) $(MAKE) $(build-crtools)=. $@
 
+lib/%:: $(VERSION_HEADER) config built-in.o
+	$(Q) $(MAKE) $(build)=lib $@
+lib: $(VERSION_HEADER) config built-in.o
+	$(Q) $(MAKE) $(build)=lib all
+
 PROGRAM-BUILTINS	+= pie/util-fd.o
 PROGRAM-BUILTINS	+= pie/util.o
 PROGRAM-BUILTINS	+= protobuf/built-in.o
@@ -176,11 +178,11 @@ clean-built:
 	$(Q) $(MAKE) $(build)=arch/$(ARCH) clean
 	$(Q) $(MAKE) $(build)=protobuf clean
 	$(Q) $(MAKE) $(build)=pie clean
+	$(Q) $(MAKE) $(build)=lib clean
 	$(Q) $(MAKE) $(build-crtools)=. clean
 	$(Q) $(MAKE) -C Documentation clean
 	$(Q) $(RM) ./include/config.h
 	$(Q) $(RM) ./$(PROGRAM)
-	$(Q) $(MAKE) -C lib clean
 
 rebuild: clean-built
 	$(E) "  FORCE-REBUILD"

lib/Makefile

-.PHONY: all clean
+obj-y			+= criu.o
 
-all: libcriu.so
+cflags-y		+= -shared -fPIC -Wa,--noexecstack -fno-stack-protector
+LDFLAGS			+= --export-dynamic
+includes		+= -iquote $(obj)/../arch/$(ARCH)/include -iquote $(obj)/../include -iquote $(obj)/..
 
-libcriu.so: criu.o
-	$(Q) $(CC) $(CFLAGS) -shared -o $@ criu.o
+.SECONDARY:
 
-criu.o:
-	$(Q) $(CC) $(CFLAGS) -fPIC -c criu.c -I ../include/
+#
+# We need util-fd.c to be re-compiled with
+# own flags, but our build engine can't
+# do such tricks yet, so write a rule
+# manually for a while.
+$(obj)/util-fd.o: $(obj)/../pie/util-fd.c
+	$(E) "  CC      " $@
+	$(Q) $(CC) -c $(cflags-y) $(CFLAGS) $(includes) $< -o $@
 
-clean:
-	$(Q) $(RM) -f *.o
-	$(Q) $(RM) -f *.so
+$(obj)/built-in.o: $(obj)/util-fd.o
+
+$(obj)/libcriu.so: $(obj)/built-in.o
+	$(E) "  GEN     " $@
+	$(Q) $(CC) $(CFLAGS) -shared $^ -o $@
+
+_all += $(obj)/built-in.o
+cleanup-y += $(obj)/*.so
+
+ifneq ($(MAKECMDGOALS),clean)
+incdeps := y
+endif