HeapCLONEOBJECT.java

package com.foursquare.heapaudit;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodAdapter;
import org.objectweb.asm.Opcodes;

class HeapCLONEOBJECT extends HeapUtil {

    // Allocations by java/lang/reflect/Constructor/newInstance
    // ([Ljava/lang/Object;)Ljava/lang/Object; or by java/lang/Object/clone
    // are triggered via calls to visitMethodInsn(INVOKEVIRTUAL) or to
    // visitMethodInsn(INVOKESPECIAL) where they return the reference to the
    // newly allocated object.

    static void after(boolean debug,
                      boolean trace,
                      MethodAdapter mv) {

        log(debug,
            trace,
            mv,
            "\tCLONEOBJECT.after");

        Label finish = new Label();

        if (HeapSettings.conditional) {

            // STACK: [...|obj]
            visitCheck(mv,
                       finish);
            // STACK: [...|obj]

        }

        // STACK: [...|obj]
        mv.visitInsn(Opcodes.DUP);
        // STACK: [...|obj|obj]
        mv.visitInsn(Opcodes.DUP);
        // STACK: [...|obj|obj|obj]
        mv.visitLdcInsn(-1);
        // STACK: [...|obj|obj|obj|count]
        mv.visitInsn(Opcodes.SWAP);
        // STACK: [...|obj|obj|count|obj]
        mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                           "java/lang/Object",
                           "getClass",
                           "()Ljava/lang/Class;");
        // STACK: [...|obj|obj|count|class]
        mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                           "java/lang/Class",
                           "getName",
                           "()Ljava/lang/String;");
        // STACK: [...|obj|obj|count|type]
        mv.visitLdcInsn((long)-1);
        // STACK: [...|obj|obj|count|type|size]
        mv.visitMethodInsn(Opcodes.INVOKESTATIC,
                           "com/foursquare/heapaudit/HeapUtil",
                           "record",
                           "(Ljava/lang/Object;ILjava/lang/String;J)V");
        // STACK: [...|obj]

        if (HeapSettings.conditional) {

            // STACK: [...|obj]
            visitFinish(mv,
                        finish);
            // STACK: [...|obj]

        }

    }

}