implemented removeMethod() etc.

git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@151 30ef5769-5b8d-40dd-aea6-55b5d6557bb3

11 files changed, 251 insertions, 136 deletions

diff --git a/src/main/javassist/CtClass.java b/src/main/javassist/CtClass.java
index 29512ace..78b40150 100644
--- a/src/main/javassist/CtClass.java
+++ b/src/main/javassist/CtClass.java
@@ -44,7 +44,7 @@ public abstract class CtClass {
     /**
      * The version number of this release.
      */
-    public static final String version = "3.0 RC1";
+    public static final String version = "3.0";
 
     /**
      * Prints the version number and the copyright notice.
@@ -55,7 +55,7 @@ public abstract class CtClass {
      */
     public static void main(String[] args) {
         System.out.println("Javassist version " + CtClass.version);
-        System.out.println("Copyright (C) 1999-2004 Shigeru Chiba."
+        System.out.println("Copyright (C) 1999-2005 Shigeru Chiba."
                            + " All Rights Reserved.");
     }
 
@@ -747,6 +747,16 @@ public abstract class CtClass {
     }
 
     /**
+     * Removes a constructor declared in this class.
+     *
+     * @param c     removed constructor.
+     * @throws NotFoundException   if the constructor is not found.
+     */
+    public void removeConstructor(CtConstructor c) throws NotFoundException {
+        checkModify();
+    }
+
+    /**
      * Adds a method.
      */
     public void addMethod(CtMethod m) throws CannotCompileException {
@@ -754,6 +764,16 @@ public abstract class CtClass {
     }
 
     /**
+     * Removes a method declared in this class.
+     *
+     * @param m     removed method.
+     * @throws NotFoundException   if the method is not found.
+     */
+    public void removeMethod(CtMethod m) throws NotFoundException {
+        checkModify();
+     }
+
+    /**
      * Adds a field.
      *
      * <p>The <code>CtField</code> belonging to another
@@ -826,6 +846,16 @@ public abstract class CtClass {
     }
 
     /**
+     * Removes a field declared in this class.
+     *
+     * @param f     removed field.
+     * @throws NotFoundException   if the field is not found.
+     */
+    public void removeField(CtField f) throws NotFoundException {
+        checkModify();
+    }
+
+    /**
      * Obtains an attribute with the given name.
      * If that attribute is not found in the class file, this
      * method returns null.
diff --git a/src/main/javassist/CtClassType.java b/src/main/javassist/CtClassType.java
index 5b249a42..d567a9b9 100644
--- a/src/main/javassist/CtClassType.java
+++ b/src/main/javassist/CtClassType.java
@@ -52,12 +52,13 @@ class CtClassType extends CtClass {
     boolean wasChanged;
     private boolean wasFrozen;
     boolean wasPruned;
+    boolean memberRemoved;
     ClassFile classfile;
 
-    private CtField fieldsCache;
-    private CtConstructor constructorsCache;
+    private CtMember fieldsCache;
+    private CtMember methodsCache;
+    private CtMember constructorsCache;
     private CtConstructor classInitializerCache;
-    private CtMethod methodsCache;
 
     private AccessorMaker accessors;
 
@@ -73,7 +74,7 @@ class CtClassType extends CtClass {
     CtClassType(String name, ClassPool cp) {
         super(name);
         classPool = cp;
-        wasChanged = wasFrozen = wasPruned = false;
+        wasChanged = wasFrozen = wasPruned = memberRemoved = false;
         classfile = null;
         accessors = null;
         fieldInitializers = null;
@@ -129,7 +130,7 @@ class CtClassType extends CtClass {
             buffer.append(" extends ??");
         }
 
-        CtField field = getFieldsCache();
+        CtMember field = getFieldsCache();
         buffer.append(" fields=");
         while (field != null) {
             buffer.append(field);
@@ -137,7 +138,7 @@ class CtClassType extends CtClass {
             field = field.next;
         }
 
-        CtConstructor c = getConstructorsCache();
+        CtMember c = getConstructorsCache();
         buffer.append(" constructors=");
         while (c != null) {
             buffer.append(c);
@@ -145,7 +146,7 @@ class CtClassType extends CtClass {
             c = c.next;
         }
 
-        CtMethod m = getMethodsCache();
+        CtMember m = getMethodsCache();
         buffer.append(" methods=");
         while (m != null) {
             buffer.append(m);
@@ -471,7 +472,7 @@ class CtClassType extends CtClass {
         }
         catch (NotFoundException e) {}
 
-        CtField cf = ((CtClassType)cc).getFieldsCache();
+        CtMember cf = ((CtClassType)cc).getFieldsCache();
         while (cf != null) {
             if (Modifier.isPublic(cf.getModifiers()))
                 alist.add(cf);
@@ -511,25 +512,25 @@ class CtClassType extends CtClass {
     }
 
     public CtField[] getDeclaredFields() {
-        CtField cf = getFieldsCache();
+        CtMember cf = getFieldsCache();
         int num = CtField.count(cf);
         CtField[] cfs = new CtField[num];
         int i = 0;
         while (cf != null) {
-            cfs[i++] = cf;
+            cfs[i++] = (CtField)cf;
             cf = cf.next;
         }
 
         return cfs;
     }
 
-    protected CtField getFieldsCache() {
+    protected CtMember getFieldsCache() {
         if (fieldsCache == null) {
             List list = getClassFile2().getFields();
             int n = list.size();
             for (int i = 0; i < n; ++i) {
                 FieldInfo finfo = (FieldInfo)list.get(i);
-                fieldsCache = CtField.append(fieldsCache,
+                fieldsCache = CtMember.append(fieldsCache,
                                              new CtField(finfo, this));
             }
         }
@@ -546,10 +547,10 @@ class CtClassType extends CtClass {
     }
 
     private CtField getDeclaredField2(String name) {
-        CtField cf = getFieldsCache();
+        CtMember cf = getFieldsCache();
         while (cf != null) {
             if (cf.getName().equals(name))
-                return cf;
+                return (CtField)cf;
 
             cf = cf.next;
         }
@@ -558,18 +559,18 @@ class CtClassType extends CtClass {
     }
 
     public CtBehavior[] getDeclaredBehaviors() {
-        CtConstructor cc = getConstructorsCache();
-        CtMethod cm = getMethodsCache();
-        int num = CtMethod.count(cm) + CtConstructor.count(cc);
+        CtMember cc = getConstructorsCache();
+        CtMember cm = getMethodsCache();
+        int num = CtMember.count(cm) + CtMember.count(cc);
         CtBehavior[] cb = new CtBehavior[num];
         int i = 0;
         while (cc != null) {
-            cb[i++] = cc;
+            cb[i++] = (CtBehavior)cc;
             cc = cc.next;
         }
 
         while (cm != null) {
-            cb[i++] = cm;
+            cb[i++] = (CtBehavior)cm;
             cm = cm.next;
         }
 
@@ -602,31 +603,31 @@ class CtClassType extends CtClass {
     public CtConstructor getConstructor(String desc)
         throws NotFoundException
     {
-        CtConstructor cc = getConstructorsCache();
+        CtConstructor cc = (CtConstructor)getConstructorsCache();
         while (cc != null) {
             if (cc.getMethodInfo2().getDescriptor().equals(desc))
                 return cc;
 
-            cc = cc.next;
+            cc = (CtConstructor)cc.next;
         }
 
         return super.getConstructor(desc);
     }
 
     public CtConstructor[] getDeclaredConstructors() {
-        CtConstructor cc = getConstructorsCache();
-        int num = CtConstructor.count(cc);
+        CtMember cc = getConstructorsCache();
+        int num = CtMember.count(cc);
         CtConstructor[] ccs = new CtConstructor[num];
         int i = 0;
         while (cc != null) {
-            ccs[i++] = cc;
+            ccs[i++] = (CtConstructor)cc;
             cc = cc.next;
         }
 
         return ccs;
     }
 
-    protected CtConstructor getConstructorsCache() {
+    protected CtMember getConstructorsCache() {
         if (constructorsCache == null) {
             List list = getClassFile2().getMethods();
             int n = list.size();
@@ -634,8 +635,8 @@ class CtClassType extends CtClass {
                 MethodInfo minfo = (MethodInfo)list.get(i);
                 if (minfo.isConstructor())
                     constructorsCache
-                        = CtConstructor.append(constructorsCache,
-                                            new CtConstructor(minfo, this));
+                        = CtMember.append(constructorsCache,
+                                          new CtConstructor(minfo, this));
             }
         }
 
@@ -675,10 +676,10 @@ class CtClassType extends CtClass {
         catch (NotFoundException e) {}
 
         if (cc instanceof CtClassType) {
-            CtMethod cm = ((CtClassType)cc).getMethodsCache();
+            CtMember cm = ((CtClassType)cc).getMethodsCache();
             while (cm != null) {
                 if (Modifier.isPublic(cm.getModifiers()))
-                    h.put(cm.getStringRep(), cm);
+                    h.put(((CtMethod)cm).getStringRep(), cm);
 
                 cm = cm.next;
             }
@@ -699,13 +700,13 @@ class CtClassType extends CtClass {
     private static CtMethod getMethod0(CtClass cc,
                                        String name, String desc) {
         if (cc instanceof CtClassType) {
-            CtMethod cm = ((CtClassType)cc).getMethodsCache();
+            CtMethod cm = (CtMethod)((CtClassType)cc).getMethodsCache();
             while (cm != null) {
                 if (cm.getName().equals(name)
                     && cm.getMethodInfo2().getDescriptor().equals(desc))
                     return cm;
 
-                cm = cm.next;
+                cm = (CtMethod)cm.next;
             }
         }
 
@@ -733,12 +734,12 @@ class CtClassType extends CtClass {
     }
 
     public CtMethod[] getDeclaredMethods() {
-        CtMethod cm = getMethodsCache();
-        int num = CtMethod.count(cm);
+        CtMember cm = getMethodsCache();
+        int num = CtMember.count(cm);
         CtMethod[] cms = new CtMethod[num];
         int i = 0;
         while (cm != null) {
-            cms[i++] = cm;
+            cms[i++] = (CtMethod)cm;
             cm = cm.next;
         }
 
@@ -746,10 +747,10 @@ class CtClassType extends CtClass {
     }
 
     public CtMethod getDeclaredMethod(String name) throws NotFoundException {
-        CtMethod m = getMethodsCache();
+        CtMember m = getMethodsCache();
         while (m != null) {
             if (m.getName().equals(name))
-                return m;
+                return (CtMethod)m;
 
             m = m.next;
         }
@@ -762,28 +763,28 @@ class CtClassType extends CtClass {
         throws NotFoundException
     {
         String desc = Descriptor.ofParameters(params);
-        CtMethod m = getMethodsCache();
+        CtMethod m = (CtMethod)getMethodsCache();
         while (m != null) {
             if (m.getName().equals(name)
                 && m.getMethodInfo2().getDescriptor().startsWith(desc))
                 return m;
 
-            m = m.next;
+            m = (CtMethod)m.next;
         }
 
         throw new NotFoundException(name + "(..) is not found in "
                                     + getName());
     }
 
-    protected CtMethod getMethodsCache() {
+    protected CtMember getMethodsCache() {
         if (methodsCache == null) {
             List list = getClassFile2().getMethods();
             int n = list.size();
             for (int i = 0; i < n; ++i) {
                 MethodInfo minfo = (MethodInfo)list.get(i);
                 if (minfo.isMethod())
-                    methodsCache = CtMethod.append(methodsCache,
-                                                new CtMethod(minfo, this));
+                    methodsCache = CtMember.append(methodsCache,
+                                                   new CtMethod(minfo, this));
             }
         }
 
@@ -824,6 +825,18 @@ class CtClassType extends CtClass {
         }
     }
 
+    public void removeField(CtField f) throws NotFoundException {
+        checkModify();
+        FieldInfo fi = f.getFieldInfo2();
+        ClassFile cf = getClassFile2();
+        if (cf.getFields().remove(fi)) {
+            fieldsCache = CtMember.remove(fieldsCache, f);
+            memberRemoved = true;
+        }
+        else
+            throw new NotFoundException(f.toString());
+    }
+
     public CtConstructor makeClassInitializer()
         throws CannotCompileException
     {
@@ -846,22 +859,46 @@ class CtClassType extends CtClass {
             throw new CannotCompileException("cannot add");
 
         getConstructorsCache();
-        constructorsCache = CtConstructor.append(constructorsCache, c);
+        constructorsCache = (CtConstructor)CtMember.append(constructorsCache, c);
         getClassFile2().addMethod(c.getMethodInfo2());
     }
 
+    public void removeConstructor(CtConstructor m) throws NotFoundException {
+        checkModify();
+        MethodInfo mi = m.getMethodInfo2();
+        ClassFile cf = getClassFile2();
+        if (cf.getMethods().remove(mi)) {
+            constructorsCache = CtMember.remove(constructorsCache, m);
+            memberRemoved = true;
+        }
+        else
+            throw new NotFoundException(m.toString());
+    }
+
     public void addMethod(CtMethod m) throws CannotCompileException {
         checkModify();
         if (m.getDeclaringClass() != this)
             throw new CannotCompileException("cannot add");
 
         getMethodsCache();
-        methodsCache = CtMethod.append(methodsCache, m);
+        methodsCache = CtMember.append(methodsCache, m);
         getClassFile2().addMethod(m.getMethodInfo2());
         if ((m.getModifiers() & Modifier.ABSTRACT) != 0)
             setModifiers(getModifiers() | Modifier.ABSTRACT);
     }
 
+    public void removeMethod(CtMethod m) throws NotFoundException {
+        checkModify();
+        MethodInfo mi = m.getMethodInfo2();
+        ClassFile cf = getClassFile2();
+        if (cf.getMethods().remove(mi)) {
+            methodsCache = CtMember.remove(methodsCache, m);
+            memberRemoved = true;
+        }
+        else
+            throw new NotFoundException(m.toString());
+    }
+
     public byte[] getAttribute(String name) {
         AttributeInfo ai = getClassFile2().getAttribute(name);
         if (ai == null)
@@ -910,6 +947,11 @@ class CtClassType extends CtClass {
             if (isModified()) {
                 checkPruned("toBytecode");
                 ClassFile cf = getClassFile2();
+                if (memberRemoved) {
+                    cf.compact();
+                    memberRemoved = false;
+                }
+
                 modifyClassConstructor(cf);
                 modifyConstructors(cf);
                 cf.write(out);
diff --git a/src/main/javassist/CtConstructor.java b/src/main/javassist/CtConstructor.java
index cac15b36..707d6863 100644
--- a/src/main/javassist/CtConstructor.java
+++ b/src/main/javassist/CtConstructor.java
@@ -33,8 +33,6 @@ import javassist.compiler.CompileError;
  * @see CtNewConstructor
  */
 public final class CtConstructor extends CtBehavior {
-    protected CtConstructor next;
-
     protected CtConstructor(MethodInfo minfo, CtClass declaring) {
         super(declaring, minfo);
         next = null;
@@ -132,30 +130,6 @@ public final class CtConstructor extends CtBehavior {
         }
     }
 
-    static CtConstructor append(CtConstructor list, CtConstructor tail) {
-        tail.next = null;
-        if (list == null)
-            return tail;
-        else {
-            CtConstructor lst = list;
-            while (lst.next != null)
-                lst = lst.next;
-
-            lst.next = tail;
-            return list;
-        }
-    }
-
-    static int count(CtConstructor m) {
-        int n = 0;
-        while (m != null) {
-            ++n;
-            m = m.next;
-        }
-
-        return n;
-    }
-
     /**
      * Returns true if this object represents a constructor.
      */
diff --git a/src/main/javassist/CtField.java b/src/main/javassist/CtField.java
index c537ed58..cfda5a22 100644
--- a/src/main/javassist/CtField.java
+++ b/src/main/javassist/CtField.java
@@ -27,7 +27,6 @@ import javassist.compiler.ast.ASTree;
  */
 public class CtField extends CtMember {
     protected FieldInfo fieldInfo;
-    CtField next;
 
     /**
      * Creates a <code>CtField</code> object.
@@ -98,6 +97,14 @@ public class CtField extends CtMember {
         next = null;
     }
 
+    /**
+     * Returns a String representation of the object.
+     */
+    public String toString() {
+        return getDeclaringClass().getName() + "." + getName()
+               + ":" + fieldInfo.getDescriptor();
+    }
+
     protected void extendToString(StringBuffer buffer) {
         buffer.append(' ');
         buffer.append(getName());
@@ -149,30 +156,6 @@ public class CtField extends CtMember {
         throw new CannotCompileException("not a field");
     }
 
-    static CtField append(CtField list, CtField tail) {
-        tail.next = null;
-        if (list == null)
-            return tail;
-        else {
-            CtField lst = list;
-            while (lst.next != null)
-                lst = lst.next;
-
-            lst.next = tail;
-            return list;
-        }
-    }
-
-    static int count(CtField f) {
-        int n = 0;
-        while (f != null) {
-            ++n;
-            f = f.next;
-        }
-
-        return n;
-    }
-
     /**
      * Returns the FieldInfo representing the field in the class file.
      */
diff --git a/src/main/javassist/CtMember.java b/src/main/javassist/CtMember.java
index 05d02bf8..59741352 100644
--- a/src/main/javassist/CtMember.java
+++ b/src/main/javassist/CtMember.java
@@ -20,10 +20,54 @@ package javassist;
  * or a method.
  */
 public abstract class CtMember {
+    protected CtMember next;          // for internal use
     protected CtClass declaringClass;
 
     protected CtMember(CtClass clazz) { declaringClass = clazz; }
 
+    static CtMember append(CtMember list, CtMember tail) {
+        tail.next = null;
+        if (list == null)
+            return tail;
+        else {
+            CtMember lst = list;
+            while (lst.next != null)
+                lst = lst.next;
+
+            lst.next = tail;
+            return list;
+        }
+    }
+
+    static int count(CtMember f) {
+        int n = 0;
+        while (f != null) {
+            ++n;
+            f = f.next;
+        }
+
+        return n;
+    }
+
+    static CtMember remove(CtMember list, CtMember m) {
+        CtMember top = list;
+        if (list == null)
+            return null;
+        else if (list == m)
+            return list.next;
+        else
+            while (list.next != null) {
+                if (list.next == m) {
+                    list.next = list.next.next;
+                    break;
+                }
+
+                list = list.next;
+            }
+
+        return top;
+    }
+
     public String toString() {
         StringBuffer buffer = new StringBuffer(getClass().getName());
         buffer.append("@");
diff --git a/src/main/javassist/CtMethod.java b/src/main/javassist/CtMethod.java
index 9d9416b3..8195e9b4 100644
--- a/src/main/javassist/CtMethod.java
+++ b/src/main/javassist/CtMethod.java
@@ -27,7 +27,6 @@ import javassist.bytecode.*;
  * @see CtNewMethod
  */
 public final class CtMethod extends CtBehavior {
-    protected CtMethod next;
     protected String cachedStringRep;
 
     CtMethod(MethodInfo minfo, CtClass declaring) {
@@ -133,30 +132,6 @@ public final class CtMethod extends CtBehavior {
         }
     }
 
-    static CtMethod append(CtMethod list, CtMethod tail) {
-        tail.next = null;
-        if (list == null)
-            return tail;
-        else {
-            CtMethod lst = list;
-            while (lst.next != null)
-                lst = lst.next;
-
-            lst.next = tail;
-            return list;
-        }
-    }
-
-    static int count(CtMethod m) {
-        int n = 0;
-        while (m != null) {
-            ++n;
-            m = m.next;
-        }
-
-        return n;
-    }
-
     /**
      * Returns a hash code value for the method.
      * If two methods have the same name and signature, then
diff --git a/src/main/javassist/bytecode/AttributeInfo.java b/src/main/javassist/bytecode/AttributeInfo.java
index 28b01846..06d89904 100644
--- a/src/main/javassist/bytecode/AttributeInfo.java
+++ b/src/main/javassist/bytecode/AttributeInfo.java
@@ -222,4 +222,18 @@ public class AttributeInfo {
             attr.write(out);
         }
     }
+
+    static LinkedList copyAll(LinkedList list, ConstPool cp) {
+        if (list == null)
+            return null;
+
+        LinkedList newList = new LinkedList();
+        int n = list.size();
+        for (int i = 0; i < n; ++i) {
+            AttributeInfo attr = (AttributeInfo)list.get(i);
+            newList.add(attr.copy(cp, null));
+        }
+
+        return newList;
+    }
 }
diff --git a/src/main/javassist/bytecode/ClassFile.java b/src/main/javassist/bytecode/ClassFile.java
index 4f85f667..5c4bc1cc 100644
--- a/src/main/javassist/bytecode/ClassFile.java
+++ b/src/main/javassist/bytecode/ClassFile.java
@@ -99,13 +99,33 @@ public final class ClassFile {
     }
 
     /**
-     * Discards all attributes, associated with both the class file and
-     * the members such as a code attribute and exceptions attribute.
-     * The unused constant pool entries are also discarded (a new packed
-     * constant pool is constructed).
+     * Eliminates dead constant pool items.  If a method or a field is removed,
+     * the constant pool items used by that method/field become dead items.
+     * This method recreates a constant pool.
      */
-    public void prune() {
+    public void compact() {
+        ConstPool cp = compact0();
+        ArrayList list = methods;
+        int n = list.size();
+        for (int i = 0; i < n; ++i) {
+            MethodInfo minfo = (MethodInfo)list.get(i);
+            minfo.compact(cp);
+        }
+
+        list = fields;
+        n = list.size();
+        for (int i = 0; i < n; ++i) {
+            FieldInfo finfo = (FieldInfo)list.get(i);
+            finfo.compact(cp);
+        }
+
+        attributes = AttributeInfo.copyAll(attributes, cp);
+        constPool = cp;
+    }
+
+    private ConstPool compact0() {
         ConstPool cp = new ConstPool(thisclassname);
+        thisClass = cp.getThisClassInfo();
         superClass = cp.addClassInfo(getSuperclass());
 
         if (interfaces != null) {
@@ -115,6 +135,18 @@ public final class ClassFile {
                     = cp.addClassInfo(constPool.getClassInfo(interfaces[i]));
         }
 
+        return cp;
+    }
+
+    /**
+     * Discards all attributes, associated with both the class file and
+     * the members such as a code attribute and exceptions attribute.
+     * The unused constant pool entries are also discarded (a new packed
+     * constant pool is constructed).
+     */
+    public void prune() {
+        ConstPool cp = compact0();
+
         ArrayList list = methods;
         int n = list.size();
         for (int i = 0; i < n; ++i) {
diff --git a/src/main/javassist/bytecode/CodeAttribute.java b/src/main/javassist/bytecode/CodeAttribute.java
index 4c7e27bb..97742d8a 100644
--- a/src/main/javassist/bytecode/CodeAttribute.java
+++ b/src/main/javassist/bytecode/CodeAttribute.java
@@ -82,19 +82,14 @@ public class CodeAttribute extends AttributeInfo implements Opcode {
         maxLocals = src.getMaxLocals();
         exceptions = src.getExceptionTable().copy(cp, classnames);
         info = src.copyCode(cp, classnames, exceptions, this);
-        attributes = new LinkedList();
 
-        /* Since an index into the source constant pool table may not
-           be translated, we don't copy the attributes.
-        */
-        /*
+        attributes = new LinkedList();
         List src_attr = src.getAttributes();
         int num = src_attr.size();
         for (int i = 0; i < num; ++i) {
             AttributeInfo ai = (AttributeInfo)src_attr.get(i);
             attributes.add(ai.copy(cp, classnames));
         }
-        */
     }
 
     CodeAttribute(ConstPool cp, int name_id, DataInputStream in)
diff --git a/src/main/javassist/bytecode/FieldInfo.java b/src/main/javassist/bytecode/FieldInfo.java
index ff45f1ba..8c2ed0a1 100644
--- a/src/main/javassist/bytecode/FieldInfo.java
+++ b/src/main/javassist/bytecode/FieldInfo.java
@@ -59,6 +59,21 @@ public final class FieldInfo {
         read(in);
     }
 
+    /**
+     * Copies all constant pool items to a given new constant pool
+     * and replaces the original items with the new ones.
+     * This is used for garbage collecting the items of removed fields
+     * and methods.
+     *
+     * @param cp    the destination
+     */
+    void compact(ConstPool cp) {
+        name = cp.addUtf8Info(getName());
+        descriptor = cp.addUtf8Info(getDescriptor());
+        attribute = AttributeInfo.copyAll(attribute, cp);
+        constPool = cp;
+    }
+
     void prune(ConstPool cp) {
         int index = getConstantValue();
         if (index == 0)
diff --git a/src/main/javassist/bytecode/MethodInfo.java b/src/main/javassist/bytecode/MethodInfo.java
index 3f3d93ef..3889fe54 100644
--- a/src/main/javassist/bytecode/MethodInfo.java
+++ b/src/main/javassist/bytecode/MethodInfo.java
@@ -30,13 +30,9 @@ import java.util.Map;
  */
 public final class MethodInfo {
     ConstPool constPool;
-
     int accessFlags;
-
     int name;
-
     int descriptor;
-
     LinkedList attribute; // may be null
 
     // Bill, do you really need this?
@@ -115,6 +111,21 @@ public final class MethodInfo {
                 + constPool.getUtf8Info(descriptor);
     }
 
+    /**
+     * Copies all constant pool items to a given new constant pool
+     * and replaces the original items with the new ones.
+     * This is used for garbage collecting the items of removed fields
+     * and methods.
+     *
+     * @param cp    the destination
+     */
+    void compact(ConstPool cp) {
+        name = cp.addUtf8Info(getName());
+        descriptor = cp.addUtf8Info(getDescriptor());
+        attribute = AttributeInfo.copyAll(attribute, cp);
+        constPool = cp;
+    }
+
     void prune(ConstPool cp) {
         attribute = null;
         name = cp.addUtf8Info(getName());