Because they use their own compilation rule, they don't use the
dependency tracking logic from Makefile.global. To make sure that
dependency tracking works anyway for the *_srv.o files, depend on
their *.o siblings as well, which do have proper dependencies. It's a
hack that might fail someday if there is a *_srv.o without a
corresponding *.o, but it works for now (and those would probably go
into src/backend/port/ anyway).
libpgport_srv.a: $(OBJS_SRV)
$(AR) $(AROPT) $@ $^
-%_srv.o: %.c
+# Because this uses its own compilation rule, it doesn't use the
+# dependency tracking logic from Makefile.global. To make sure that
+# dependency tracking works anyway for the *_srv.o files, depend on
+# their *.o siblings as well, which do have proper dependencies. It's
+# a hack that might fail someday if there is a *_srv.o without a
+# corresponding *.o, but it works for now (and those would probably go
+# into src/backend/port/ anyway).
+%_srv.o: %.c %.o
$(CC) $(CFLAGS) $(subst -DFRONTEND,, $(CPPFLAGS)) -c $< -o $@
$(OBJS_SRV): | submake-errcodes