diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/SignatureIterator.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/SignatureIterator.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2001, 2010, 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 sun.jvm.hotspot.runtime;
+
+import sun.jvm.hotspot.oops.*;
+
+/** <P> SignatureIterators iterate over a Java signature (or parts of it).
+    (Syntax according to: "The Java Virtual Machine Specification" by
+    Tim Lindholm & Frank Yellin; section 4.3 Descriptors; p. 89ff.) </P>
+
+    <P> Example: Iterating over
+<PRE>
+([Lfoo;D)I
+0123456789
+</PRE>
+
+    using </P>
+
+<PRE>
+iterateParameters() calls: do_array(2, 7); do_double();
+iterateReturntype() calls:                              do_int();
+iterate()           calls: do_array(2, 7); do_double(); do_int();
+
+is_returnType()        is: false         ; false      ; true
+</PRE>
+*/
+
+public abstract class SignatureIterator {
+  protected Symbol _signature;       // the signature to iterate over
+  protected int    _index;           // the current character index (only valid during iteration)
+  protected int    _parameter_index; // the current parameter index (0 outside iteration phase)
+
+  protected void expect(char c) {
+    if (_signature.getByteAt(_index) != (byte) c) {
+      throw new RuntimeException("expecting '" + c + "'");
+    }
+    _index++;
+  }
+  protected void skipOptionalSize() {
+    byte c = _signature.getByteAt(_index);
+    while ('0' <= c && c <= '9') {
+      c = _signature.getByteAt(++_index);
+    }
+  }
+  // returns the parameter size in words (0 for void)
+  protected int parseType() {
+    switch(_signature.getByteAt(_index)) {
+    case 'B': doByte  (); _index++; return BasicTypeSize.getTByteSize();
+    case 'C': doChar  (); _index++; return BasicTypeSize.getTCharSize();
+    case 'D': doDouble(); _index++; return BasicTypeSize.getTDoubleSize();
+    case 'F': doFloat (); _index++; return BasicTypeSize.getTFloatSize();
+    case 'I': doInt   (); _index++; return BasicTypeSize.getTIntSize();
+    case 'J': doLong  (); _index++; return BasicTypeSize.getTLongSize();
+    case 'S': doShort (); _index++; return BasicTypeSize.getTShortSize();
+    case 'Z': doBool  (); _index++; return BasicTypeSize.getTBooleanSize();
+    case 'V':
+      {
+        if (!isReturnType()) {
+          throw new RuntimeException("illegal parameter type V (void)");
+        }
+
+        doVoid(); _index++;
+        return BasicTypeSize.getTVoidSize();
+      }
+    case 'L':
+      {
+        int begin = ++_index;
+        while (_signature.getByteAt(_index++) != ';') ;
+        doObject(begin, _index);
+        return BasicTypeSize.getTObjectSize();
+      }
+    case '[':
+      {
+        int begin = ++_index;
+        skipOptionalSize();
+        while (_signature.getByteAt(_index) == '[') {
+          _index++;
+          skipOptionalSize();
+        }
+        if (_signature.getByteAt(_index) == 'L') {
+          while (_signature.getByteAt(_index++) != ';') ;
+        } else {
+          _index++;
+        }
+        doArray(begin, _index);
+        return BasicTypeSize.getTArraySize();
+      }
+    }
+    throw new RuntimeException("Should not reach here: char " + (char)_signature.getByteAt(_index) + " @ " + _index + " in " + _signature.asString());
+  }
+  protected void checkSignatureEnd() {
+    if (_index < _signature.getLength()) {
+      System.err.println("too many chars in signature");
+      _signature.printValueOn(System.err);
+      System.err.println(" @ " + _index);
+    }
+  }
+
+  public SignatureIterator(Symbol signature) {
+    _signature       = signature;
+    _parameter_index = 0;
+  }
+
+  //
+  // Iteration
+  //
+
+  // dispatches once for field signatures
+  public void dispatchField() {
+    // no '(', just one (field) type
+    _index = 0;
+    _parameter_index = 0;
+    parseType();
+    checkSignatureEnd();
+  }
+
+  // iterates over parameters only
+  public void iterateParameters() {
+    // Parse parameters
+    _index = 0;
+    _parameter_index = 0;
+    expect('(');
+    while (_signature.getByteAt(_index) != ')') {
+      _parameter_index += parseType();
+    }
+    expect(')');
+    _parameter_index = 0; // so isReturnType() is false outside iteration
+  }
+
+  // iterates over returntype only
+  public void iterateReturntype() {
+    // Ignore parameters
+    _index = 0;
+    expect('(');
+    while (_signature.getByteAt(_index) != ')') {
+      _index++;
+    }
+    expect(')');
+    // Parse return type
+    _parameter_index = -1;
+    parseType();
+    checkSignatureEnd();
+    _parameter_index = 0; // so isReturnType() is false outside iteration
+  }
+
+  // iterates over whole signature
+  public void iterate() {
+    // Parse parameters
+    _index = 0;
+    _parameter_index = 0;
+    expect('(');
+    while (_signature.getByteAt(_index) != ')') {
+      _parameter_index += parseType();
+    }
+    expect(')');
+    // Parse return type
+    _parameter_index = -1;
+    parseType();
+    checkSignatureEnd();
+    _parameter_index = 0; // so isReturnType() is false outside iteration
+  }
+
+  // Returns the word index of the current parameter; returns a negative value at the return type
+  public int  parameterIndex()               { return _parameter_index; }
+  public boolean isReturnType()              { return (parameterIndex() < 0); }
+
+  // Basic types
+  public abstract void doBool  ();
+  public abstract void doChar  ();
+  public abstract void doFloat ();
+  public abstract void doDouble();
+  public abstract void doByte  ();
+  public abstract void doShort ();
+  public abstract void doInt   ();
+  public abstract void doLong  ();
+  public abstract void doVoid  ();
+
+  // Object types (begin indexes the first character of the entry, end
+  // indexes the first character after the entry)
+  public abstract void doObject(int begin, int end);
+  public abstract void doArray (int begin, int end);
+}