re PR c++/57948 (internal compiler error: in initialize_reference, at cp/call.c:9285)

/cp
2013-07-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/57948
	* call.c (initialize_reference): Don't crash when reference_binding
	returns a conv with conv->kind == ck_ambig.

/testsuite
2013-07-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/57948
	* g++.dg/conversion/ambig2.C: New.

From-SVN: r201318

gcc/cp/ChangeLog

+2013-07-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/57948
+	* call.c (initialize_reference): Don't crash when reference_binding
+	returns a conv with conv->kind == ck_ambig.
+
 2013-07-29  Jason Merrill  <jason@redhat.com>
 
 	* mangle.c (write_name): Check for null context.

gcc/cp/call.c

@@ -9282,10 +9282,14 @@ initialize_reference (tree type, tree expr,
       return error_mark_node;
     }
 
-  gcc_assert (conv->kind == ck_ref_bind);
-
-  /* Perform the conversion.  */
-  expr = convert_like (conv, expr, complain);
+  if (conv->kind == ck_ref_bind)
+    /* Perform the conversion.  */
+    expr = convert_like (conv, expr, complain);
+  else if (conv->kind == ck_ambig)
+    /* We gave an error in build_user_type_conversion_1.  */
+    expr = error_mark_node;
+  else
+    gcc_unreachable ();
 
   /* Free all the conversions we allocated.  */
   obstack_free (&conversion_obstack, p);

gcc/testsuite/ChangeLog

+2013-07-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/57948
+	* g++.dg/conversion/ambig2.C: New.
+
 2013-07-29  Maciej W. Rozycki  <macro@codesourcery.com>
 
 	* gcc.target/mips/fabs-2008.c: New test case.
@@ -85,7 +90,7 @@
 	* gcc.c-torture/execute/builtins/stpcpy-chk.x: Likewise.
 
 	* gcc.dg/pr27095.c: For Epiphany, add -mshort-calls.
-	* gcc.dg/tree-ssa/loop-1.c: Likewise. 
+	* gcc.dg/tree-ssa/loop-1.c: Likewise.
 
 	* gcc.dg/torture/pr37868.c: Disable for epiphany.
 	* gcc.dg/sibcall-6.c: Enable for epiphany.

gcc/testsuite/g++.dg/conversion/ambig2.C

+// PR c++/57948
+
+struct Base {   };
+struct Derived : Base
+{
+  struct Derived2 : Base
+  {
+    struct ConvertibleToBothDerivedRef
+    {
+      operator Derived&();
+      operator Derived2&();
+      void bind_lvalue_to_conv_lvalue_ambig(ConvertibleToBothDerivedRef both)
+      {
+	Base &br1 = both; // { dg-error "ambiguous" }
+      }
+    };
+  };
+};