2 files changed, 66 insertions, 0 deletions
diff --git a/src/main/javassist/CodeConverter.java b/src/main/javassist/CodeConverter.java
index 6df3622c..10d7ddad 100644
--- a/src/main/javassist/CodeConverter.java
+++ b/src/main/javassist/CodeConverter.java
@@ -25,6 +25,7 @@ import javassist.convert.TransformAccessArrayField;
 import javassist.convert.TransformAfter;
 import javassist.convert.TransformBefore;
 import javassist.convert.TransformCall;
+import javassist.convert.TransformCallToStatic;
 import javassist.convert.TransformFieldAccess;
 import javassist.convert.TransformNew;
 import javassist.convert.TransformNewClass;
@@ -407,6 +408,42 @@ public class CodeConverter {
     }
 
     /**
+     * Redirect non-static method invocations in a method body to a static
+     * method. The return type must be same with the originally invoked method.
+     * As parameters, the static method receives
+     * the target object and all the parameters to the originally invoked
+     * method.  For example, if the originally invoked method is
+     * <code>move()</code>:
+     *
+     * <pre>class Point {
+     *     Point move(int x, int y) { ... }
+     * }</pre>
+     *
+     * <p>Then the static method must be something like this:
+     *
+     * <pre>class Verbose {
+     *     static Point print(Point target, int x, int y) { ... }
+     * }</pre>
+     *
+     * <p>The <code>CodeConverter</code> would translate bytecode
+     * equivalent to:
+     *
+     * <pre>Point p2 = p.move(x + y, 0);</pre>
+     *
+     * <p>into the bytecode equivalent to:
+     *
+     * <pre>Point p2 = Verbose.print(p, x + y, 0);</pre>
+     *
+     * @param origMethod   original method
+     * @param staticMethod static method
+     */
+    public void redirectMethodCallToStatic(CtMethod origMethod,
+                                           CtMethod staticMethod) {
+        transformers = new TransformCallToStatic(transformers, origMethod,
+                staticMethod);
+    }
+
+    /**
      * Insert a call to another method before an existing method call.
      * That "before" method must be static.  The return type must be
      * <code>void</code>.  As parameters, the before method receives
diff --git a/src/main/javassist/convert/TransformCallToStatic.java b/src/main/javassist/convert/TransformCallToStatic.java
new file mode 100644
index 00000000..87181edf
--- /dev/null
+++ b/src/main/javassist/convert/TransformCallToStatic.java
@@ -0,0 +1,29 @@
+package javassist.convert;
+
+import javassist.CtMethod;
+import javassist.bytecode.BadBytecode;
+import javassist.bytecode.CodeIterator;
+import javassist.bytecode.ConstPool;
+import javassist.bytecode.Descriptor;
+import javassist.bytecode.Opcode;
+
+public class TransformCallToStatic extends TransformCall {
+    public TransformCallToStatic(Transformer next, CtMethod origMethod, CtMethod substMethod) {
+        super(next, origMethod, substMethod);
+        methodDescriptor = origMethod.getMethodInfo2().getDescriptor();
+    }
+
+    @Override
+    protected int match(int c, int pos, CodeIterator iterator, int typedesc, ConstPool cp) {
+        if (newIndex == 0) {
+            String desc = Descriptor.insertParameter(classname, methodDescriptor);
+            int nt = cp.addNameAndTypeInfo(newMethodname, desc);
+            int ci = cp.addClassInfo(newClassname);
+            newIndex = cp.addMethodrefInfo(ci, nt);
+            constPool = cp;
+        }
+        iterator.writeByte(Opcode.INVOKESTATIC, pos);
+        iterator.write16bit(newIndex, pos + 1);
+        return pos;
+    }
+}