+2014-08-18 David Malcolm <dmalcolm@redhat.com>
+
+ * is-a.h (template<T, U> safe_as_a <U *p>) New function.
+
2014-08-18 Jan Hubicka <hubicka@ucw.cz>
* ipa-visibility.c (update_visibility_by_resolution_info): Do no turn UNDEF
do_something_with (as_a <cgraph_node *> *ptr);
+TYPE safe_as_a <TYPE> (pointer)
+
+ Like as_a <TYPE> (pointer), but where pointer could be NULL. This
+ adds a check against NULL where the regular is_a_helper hook for TYPE
+ assumes non-NULL.
+
+ do_something_with (safe_as_a <cgraph_node *> *ptr);
+
TYPE dyn_cast <TYPE> (pointer)
Converts pointer to TYPE if and only if "is_a <TYPE> pointer". Otherwise,
return is_a_helper <T>::cast (p);
}
+/* Similar to as_a<>, but where the pointer can be NULL, even if
+ is_a_helper<T> doesn't check for NULL. */
+
+template <typename T, typename U>
+inline T
+safe_as_a (U *p)
+{
+ if (p)
+ {
+ gcc_checking_assert (is_a <T> (p));
+ return is_a_helper <T>::cast (p);
+ }
+ else
+ return NULL;
+}
+
/* A generic checked conversion from a base type U to a derived type T. See
the discussion above for when to use this function. */