--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.ruby.runtime/src/com/oracle/truffle/ruby/runtime/control/ExceptionTranslator.java	Mon Jan 06 17:12:09 2014 +0000
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2013 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+package com.oracle.truffle.ruby.runtime.control;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.ruby.runtime.*;
+import com.oracle.truffle.ruby.runtime.core.*;
+import com.oracle.truffle.ruby.runtime.objects.*;
+
+public final class ExceptionTranslator {
+
+    /**
+     * Translate a Java exception into a Ruby exception.
+     */
+    public static RubyBasicObject translateException(RubyContext context, Throwable exception) {
+        assert context != null;
+        assert exception != null;
+
+        CompilerAsserts.neverPartOfCompilation();
+
+        // RaiseException already includes the Ruby exception
+
+        if (exception instanceof RaiseException) {
+            return ((RaiseException) exception).getRubyException();
+        }
+
+        // Translate divide by zero into ZeroDivisionError
+
+        if (exception instanceof ArithmeticException && (exception.getMessage().endsWith("divide by zero") || exception.getMessage().endsWith("/ by zero"))) {
+            return new RubyException(context.getCoreLibrary().getZeroDivisionErrorClass(), "divided by 0");
+        }
+
+        /*
+         * If we can't translate the exception into a Ruby exception, then the error is ours and we
+         * report it as as RubyTruffleError. If a programmer sees this then it's a bug in our
+         * implementation.
+         */
+
+        if (context.getConfiguration().getPrintJavaExceptions()) {
+            exception.printStackTrace();
+        }
+
+        String message;
+
+        if (exception.getMessage() == null) {
+            message = exception.getClass().getSimpleName();
+        } else {
+            message = exception.getMessage();
+        }
+
+        return new RubyException(context.getCoreLibrary().getRubyTruffleErrorClass(), message);
+    }
+
+}