[C++ PATCH] vfunc overrider simplification

https://gcc.gnu.org/ml/gcc-patches/2019-08/msg01674.html
	cp/
	* class.c (check_for_overrides): Conversion operators need
	checking too.

	testsuite/
	* g++.dg/inherit/virtual14.C: New.

From-SVN: r274903

gcc/cp/ChangeLog

+2019-08-24  Nathan Sidwell  <nathan@acm.org>
+
+	* class.c (check_for_overrides): Conversion operators need
+	checking too.
+
 2019-08-24  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* semantics.c (finish_switch_cond): Improve error message location.
 
-2019-08-22  Jason Merrill  <jason@redhat.com>
+2019-08-23  Jason Merrill  <jason@redhat.com>
 
 	* decl2.c (decl_dependent_p): New.
 	(mark_used): Check it instead of just processing_template_decl.
 
-2019-08-22  Jason Merrill  <jason@redhat.com>
+2019-08-23  Jason Merrill  <jason@redhat.com>
 
 	* parser.c (cp_parser_nested_name_specifier_opt): Avoid redundant
 	error.

gcc/cp/class.c

@@ -2817,10 +2817,12 @@ check_for_override (tree decl, tree ctype)
     return;
 
   /* IDENTIFIER_VIRTUAL_P indicates whether the name has ever been
-     used for a vfunc.  That avoids the expensive
-     look_for_overrides call that when we know there's nothing to
-     find.  */
-  if (IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
+     used for a vfunc.  That avoids the expensive look_for_overrides
+     call that when we know there's nothing to find.  As conversion
+     operators for the same type can have distinct identifiers, we
+     cannot optimize those in that way.  */
+  if ((IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
+       || DECL_CONV_FN_P (decl))
       && look_for_overrides (ctype, decl)
       /* Check staticness after we've checked if we 'override'.  */
       && !DECL_STATIC_FUNCTION_P (decl))

gcc/testsuite/ChangeLog

+2019-08-24  Nathan Sidwell  <nathan@acm.org>
+
+	* g++.dg/inherit/virtual14.C: New.
+
 2019-08-24  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/91390

gcc/testsuite/g++.dg/inherit/virtual14.C

+// { dg-do run }
+
+struct base 
+{
+  virtual operator int () { return 0;}
+};
+
+typedef int q;
+
+struct d : base
+{
+  operator q () { return 1; }
+};
+
+int invoke (base *d)
+{
+  return int (*d);
+}
+
+int main ()
+{
+  d d;
+  return !(invoke (&d) == 1);
+}