-size_t base_len (char const *file);
-size_t dir_len (char const *file);
-char *last_component (char const *file);
+size_t base_len (char const *file) _GL_ATTRIBUTE_PURE;
+size_t dir_len (char const *file) _GL_ATTRIBUTE_PURE;
+char *last_component (char const *file) _GL_ATTRIBUTE_PURE;