added InnerClassAttribute#remove method

3 files changed, 67 insertions, 0 deletions

diff --git a/src/main/javassist/bytecode/InnerClassesAttribute.java b/src/main/javassist/bytecode/InnerClassesAttribute.java
index 5dffd6ee..cf021791 100644
--- a/src/main/javassist/bytecode/InnerClassesAttribute.java
+++ b/src/main/javassist/bytecode/InnerClassesAttribute.java
@@ -198,6 +198,40 @@ public class InnerClassesAttribute extends AttributeInfo {
     }
 
     /**
+     * Removes the {@code nth} entry.  It does not eliminate
+     * constant pool items that the removed entry refers to.
+     * {@link ClassFile#compact()} should be executed to remove
+     * these unnecessary items. 
+     *
+     * @param nth       0, 1, 2, ...
+     * @return  the number of items after the removal.
+     * @see ClassFile#compact()
+     */
+    public int remove(int nth) {
+        byte[] data = get();
+        int len = data.length;
+        if (len < 10)
+            return 0;
+
+        int n = ByteArray.readU16bit(data, 0);
+        int nthPos = 2 + nth * 8;
+        if (n <= nth)
+            return n;
+
+        byte[] newData = new byte[len - 8];
+        ByteArray.write16bit(n - 1, newData, 0);
+        int i = 2, j = 2;
+        while (i < len)
+            if (i == nthPos)
+                i += 8;
+            else
+                newData[j++] = data[i++];
+
+        set(newData);
+        return n - 1;
+    }
+
+    /**
      * Makes a copy.  Class names are replaced according to the
      * given <code>Map</code> object.
      *
diff --git a/src/test/javassist/JvstTest5.java b/src/test/javassist/JvstTest5.java
index cefc84fc..6afb41a2 100644
--- a/src/test/javassist/JvstTest5.java
+++ b/src/test/javassist/JvstTest5.java
@@ -3,6 +3,9 @@ package javassist;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.TypeVariable;
 
+import javassist.bytecode.ClassFile;
+import javassist.bytecode.InnerClassesAttribute;
+
 public class JvstTest5 extends JvstTestRoot {
     public JvstTest5(String name) {
         super(name);
@@ -100,4 +103,26 @@ public class JvstTest5 extends JvstTestRoot {
         Object obj = make(cc.getName());
         assertEquals(1, invoke(obj, "run"));
     }
+
+    public void testInnerClassAttributeRemove() throws Exception {
+        CtClass cc = sloader.get("test5.InnerClassRemove");
+        ClassFile cf = cc.getClassFile();
+        InnerClassesAttribute ica = (InnerClassesAttribute)cf.getAttribute(InnerClassesAttribute.tag);
+        String second = ica.innerClass(1);
+        String secondName = ica.innerName(1);
+        String third = ica.innerClass(2);
+        String thirdName = ica.innerName(2);
+        assertEquals(3, ica.remove(3));
+        assertEquals(2, ica.remove(0));
+        assertEquals(second, ica.innerClass(0));
+        assertEquals(secondName, ica.innerName(0));
+        assertEquals(third, ica.innerClass(1));
+        assertEquals(thirdName, ica.innerName(1));
+        assertEquals(1, ica.remove(1));
+        assertEquals(second, ica.innerClass(0));
+        assertEquals(secondName, ica.innerName(0));
+        cc.writeFile();
+        Object obj = make(cc.getName());
+        assertEquals(1, invoke(obj, "run"));
+    }
 }
diff --git a/src/test/test5/InnerClassRemove.java b/src/test/test5/InnerClassRemove.java
new file mode 100644
index 00000000..8fff676b
--- /dev/null
+++ b/src/test/test5/InnerClassRemove.java
@@ -0,0 +1,8 @@
+package test5;
+
+public class InnerClassRemove {
+    public class A { int a; } 
+    class B { int b; } 
+    static class C { int c; } 
+    public int run() { return 1; }
+}