diff -r 0712796e4039 -r 04815c29859c hotspot/test/compiler/compilercontrol/share/JSONFile.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/compilercontrol/share/JSONFile.java	Tue Oct 20 21:09:57 2015 +0300
@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package compiler.compilercontrol.share;
+
+import java.io.FileNotFoundException;
+import java.io.PrintStream;
+import java.util.Objects;
+import java.util.Stack;
+
+/**
+ * Simple JSON file writer
+ */
+public class JSONFile implements AutoCloseable {
+    private final Stack<Element> stack;
+    private final String fileName;
+    private final PrintStream out;
+    private int spaces;
+
+    /**
+     * JSON element
+     */
+    public enum Element {
+        OBJECT,
+        ARRAY,
+        PAIR,
+        VALUE
+    }
+
+    /**
+     * Constructor. Creates file with default name
+     */
+    public JSONFile() {
+        this("directives_file.json");
+    }
+
+    /**
+     * Constructor
+     *
+     * @param fileName file name
+     */
+    public JSONFile(String fileName) {
+        this.spaces = 0;
+        this.stack = new Stack<>();
+        this.fileName = fileName;
+        try {
+            out = new PrintStream(fileName);
+        } catch (FileNotFoundException e) {
+            throw new Error("TESTBUG: can't open/create file " + fileName, e);
+        }
+    }
+
+    /**
+     * Gets file name
+     *
+     * @return file name string
+     */
+    public String getFileName() {
+        return fileName;
+    }
+
+    /**
+     * Gets current JSON element in the file.
+     * The element is a current {@linkplain Element}
+     * that was written into a file.
+     *
+     * @return the type of the current element,
+     * or null if there are nothing written
+     */
+    public Element getElement() {
+        if (stack.empty()) {
+            return null;
+        }
+        return stack.peek();
+    }
+
+    /**
+     * Writes given type with a value to file.
+     * Note that only PAIR and VALUE types accept a single value parameter.
+     * OBJECT and ARRAY do not have a value
+     *
+     * @param element  JSON element type
+     * @param value element's value
+     * @return this file instance
+     */
+    public JSONFile write(Element element, String... value) {
+        if (value.length > 1) {
+            throw new Error("TESTBUG: Unexpected value length: "
+                    + value.length);
+        }
+        if (!stack.empty()) {
+            if (stack.peek() == Element.VALUE) {
+                out.print(", ");
+                stack.pop();
+            }
+        }
+        switch (element) {
+            case OBJECT:
+                out.print("{");
+                spaces++;
+                stack.push(Element.VALUE);
+                break;
+            case ARRAY:
+                out.print("[");
+                stack.push(Element.VALUE);
+                break;
+            case PAIR:
+                fillSpaces();
+                Objects.requireNonNull(value, "TESTBUG: " + element
+                        + "requires a value to be set");
+                out.print(value[0] + ": ");
+                break;
+            case VALUE:
+                Objects.requireNonNull(value, "TESTBUG: " + element
+                        + "requires a value to be set");
+                out.print(value[0]);
+                break;
+        }
+        stack.push(element);
+        return this;
+    }
+
+    private void fillSpaces() {
+        out.println();
+        for (int i = 0; i < spaces; i++) {
+            // Fill with spaces to be more readable
+            out.print("  ");
+        }
+    }
+
+    /**
+     * Ends current object or array of {@linkplain Element}
+     *
+     * @return this file instance
+     */
+    public JSONFile end() {
+        if (!stack.empty()) {
+            Element prev = stack.pop();
+            while (prev != Element.OBJECT && prev != Element.ARRAY
+                    && !stack.empty()) {
+                prev = stack.pop();
+            }
+            switch (prev) {
+                case OBJECT:
+                    spaces--;
+                    fillSpaces();
+                    out.print("}");
+                    break;
+                case ARRAY:
+                    out.print("]");
+                    break;
+                default:
+                    throw new Error("TESTBUG: Incorrect end. " +
+                            "Wrong type found: " + prev);
+            }
+        } else {
+            throw new Error("TESTBUG: Incorrect end. Empty stack");
+        }
+        return this;
+    }
+
+    /**
+     * Closes this file
+     */
+    @Override
+    public void close() {
+        out.close();
+    }
+}