8060717: [TESTBUG] Improve test coverage of MethodHandles.explicitCastArguments()

Reviewed-by: vlivanov, mhaupt

test/java/lang/invoke/LFCaching/TestMethods.java

 /*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -610,26 +610,7 @@ public enum TestMethods {
      * @return MethodType generated randomly.
      */
     private static MethodType randomMethodTypeGenerator(int arity) {
-        final Class<?>[] CLASSES = {
-            Object.class,
-            int.class,
-            boolean.class,
-            byte.class,
-            short.class,
-            char.class,
-            long.class,
-            float.class,
-            double.class
-        };
-        if (arity > Helper.MAX_ARITY) {
-            throw new IllegalArgumentException(
-                    String.format("Arity should not exceed %d!", Helper.MAX_ARITY));
-        }
-        List<Class<?>> list = Helper.randomClasses(CLASSES, arity);
-        list = Helper.getParams(list, false, arity);
-        int i = Helper.RNG.nextInt(CLASSES.length + 1);
-        Class<?> rtype = i == CLASSES.length ? void.class : CLASSES[i];
-        return MethodType.methodType(rtype, list);
+        return Helper.randomMethodTypeGenerator(arity);
     }
 
     /**

test/lib/testlibrary/jsr292/com/oracle/testlibrary/jsr292/Helper.java

 /*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -315,4 +315,33 @@ public class Helper {
         }
         return null;
     }
+
+    /**
+     * Routine used to obtain a randomly generated method type.
+     *
+     * @param arity Arity of returned method type.
+     * @return MethodType generated randomly.
+     */
+    public static MethodType randomMethodTypeGenerator(int arity) {
+        final Class<?>[] CLASSES = {
+            Object.class,
+            int.class,
+            boolean.class,
+            byte.class,
+            short.class,
+            char.class,
+            long.class,
+            float.class,
+            double.class
+        };
+        if (arity > MAX_ARITY) {
+            throw new IllegalArgumentException(
+                    String.format("Arity should not exceed %d!", MAX_ARITY));
+        }
+        List<Class<?>> list = randomClasses(CLASSES, arity);
+        list = getParams(list, false, arity);
+        int i = RNG.nextInt(CLASSES.length + 1);
+        Class<?> rtype = i == CLASSES.length ? void.class : CLASSES[i];
+        return MethodType.methodType(rtype, list);
+    }
 }