src/jdk/nashorn/api/scripting/NashornException.java

*** 27,36 ****
--- 27,37 ----
  
  import java.util.ArrayList;
  import java.util.List;
  import jdk.nashorn.internal.codegen.CompilerConstants;
  import jdk.nashorn.internal.runtime.ECMAErrors;
+ import jdk.nashorn.internal.runtime.ScriptObject;
  
  /**
   * This is base exception for all Nashorn exceptions. These originate from
   * user's ECMAScript code. Example: script parse errors, exceptions thrown from
   * scripts. Note that ScriptEngine methods like "eval", "invokeMethod",
*** 47,56 ****
--- 48,59 ----
      private final String fileName;
      // script line number
      private final int line;
      // script column number
      private final int column;
+     // underlying ECMA error object - lazily initialized
+     private Object ecmaError;
  
      /** script source name used for "engine.js" */
      public static final String ENGINE_SCRIPT_SOURCE_NAME = "nashorn:engine/resources/engine.js";
  
      /**
*** 186,191 ****
--- 189,223 ----
              assert buf.charAt(len - 1) == '\n';
              buf.deleteCharAt(len - 1);
          }
          return buf.toString();
      }
+     
+     protected Object getThrown() {
+         return null;
+     }
+     
+     protected NashornException initEcmaError(final ScriptObject global) {
+         if (ecmaError != null) {
+             return this; // initialized already!
+         }
+         
+         final Object thrown = getThrown();
+         if (thrown instanceof ScriptObject) {
+             ecmaError = ScriptObjectMirror.wrap(thrown, global);
+         } else {
+             ecmaError = thrown;
+         }
+         
+         return this;
+     }
+ 
+     /**
+      * Return the underlying ECMA error object, if available.
+      *
+      * @return underlying ECMA Error object's mirror or whatever was thrown
+      *         from script such as a String, Number or a Boolean.
+      */    
+     public Object getEcmaError() {
+         return ecmaError;
+     }
  }