module RbSys::Mkmf

def deffile_definition
  warn("EXPORT_PREFIX is not defined, please require \"mkmf\" before requiring \"rb_sys/mkmf\"") unless defined?(EXPORT_PREFIX)
  return unless defined?(EXPORT_PREFIX) && EXPORT_PREFIX
  @deffile_definition ||= <<~MAKE
    $(DEFFILE):
    \t$(ECHO) creating target directory \\($(RUSTLIBDIR)\\)
    \t$(Q) $(MAKEDIRS) $(RUSTLIBDIR)
    \t$(ECHO) generating $(@)
    \t$(ECHO) EXPORTS > $@
    \t$(ECHO) $(TARGET_ENTRY) >> $@
  MAKE
end