re PR c++/88122 (g++ ICE: internal compiler error: Segmentation fault)

	PR c++/88122
	* method.c (maybe_explain_implicit_delete): If
	FUNCTION_FIRST_USER_PARMTYPE (decl) is NULL, set const_p to false
	instead of ICEing.

	* g++.dg/cpp0x/implicit15.C: New test.

From-SVN: r266360

gcc/cp/ChangeLog

 2018-11-21  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/88122
+	* method.c (maybe_explain_implicit_delete): If
+	FUNCTION_FIRST_USER_PARMTYPE (decl) is NULL, set const_p to false
+	instead of ICEing.
+
 	PR c++/87386
 	* parser.c (cp_parser_primary_expression): Use
 	id_expression.get_location () instead of id_expr_token->location.

gcc/cp/method.c

@@ -1821,8 +1821,12 @@ maybe_explain_implicit_delete (tree decl)
       if (!informed)
 	{
 	  tree parms = FUNCTION_FIRST_USER_PARMTYPE (decl);
-	  tree parm_type = TREE_VALUE (parms);
-	  bool const_p = CP_TYPE_CONST_P (non_reference (parm_type));
+	  bool const_p = false;
+	  if (parms)
+	    {
+	      tree parm_type = TREE_VALUE (parms);
+	      const_p = CP_TYPE_CONST_P (non_reference (parm_type));
+	    }
 	  tree raises = NULL_TREE;
 	  bool deleted_p = false;
 	  tree scope = push_scope (ctype);

gcc/testsuite/ChangeLog

 2018-11-21  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/88122
+	* g++.dg/cpp0x/implicit15.C: New test.
+
 	PR c++/87386
 	* g++.dg/diagnostic/pr87386.C: New test.
 	* g++.dg/parse/error17.C: Adjust expected diagnostics.

gcc/testsuite/g++.dg/cpp0x/implicit15.C

+// PR c++/88122
+// { dg-do compile { target c++11 } }
+
+struct A {
+  A (...);	// { dg-message "candidate" }
+  A ();		// { dg-message "candidate" }
+};
+struct B : A {
+  using A::A;	// { dg-error "is ambiguous" }
+		// { dg-message "is implicitly deleted because the default definition would be ill-formed" "" { target *-*-* } .-1 }
+} b{3};		// { dg-error "use of deleted function" }