HeapNEWINSTANCE.java

package com.foursquare.heapaudit;

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

class HeapNEWINSTANCE extends HeapUtil {

    // Allocations by java/lang/Class/newInstance()Ljava/lang/Object; are
    // triggered via calls to visitMethodInsn(INVOKEVIRTUAL) where the top of
    // the stack contains the name of the class and returns a reference to the
    // newly allocated class object.

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

        log(debug,
            trace,
            mv,
            "\tNEWINSTANCE.before");

        // STACK: [...|class]
        mv.visitLdcInsn(-1);
        // STACK: [...|class|count]
        mv.visitInsn(Opcodes.SWAP);
        // STACK: [...|count|class]
        mv.visitInsn(Opcodes.DUP);
        // STACK: [...|count|class|class]

    }

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

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

        Label cleanup = new Label();

        Label finish = new Label();

        if (HeapSettings.conditional) {

            // STACK: [...|count|class|obj]
            visitCheck(mv,
                       cleanup);
            // STACK: [...|count|class|obj]

        }

        // STACK: [...|count|class|obj]
        mv.visitInsn(Opcodes.DUP_X2);
        // STACK: [...|obj|count|class|obj]
        mv.visitInsn(Opcodes.DUP_X2);
        // STACK: [...|obj|obj|count|class|obj]
        mv.visitInsn(Opcodes.POP);
        // 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) {

            visitCleanup(mv,
                         cleanup,
                         finish);
            // STACK: [...|count|class|obj]
            mv.visitInsn(Opcodes.SWAP);
            // STACK: [...|count|obj|class]
            mv.visitInsn(Opcodes.POP);
            // STACK: [...|count|obj]
            mv.visitInsn(Opcodes.SWAP);
            // STACK: [...|obj|count]
            mv.visitInsn(Opcodes.POP);
            // STACK: [...|obj]
            visitFinish(mv,
                        finish);
            // STACK: [...|obj]

        }

    }

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

        log(debug,
            trace,
            mv,
            "\tNEWINSTANCE.beforeX");

        // STACK: [...|class|count]
        mv.visitInsn(Opcodes.SWAP);
        // STACK: [...|count|class]
        mv.visitInsn(Opcodes.DUP2);
        // STACK: [...|count|class|count|class]
        mv.visitInsn(Opcodes.SWAP);
        // STACK: [...|count|class|class|count]

    }

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

        log(debug,
            trace,
            mv,
            "\tNEWINSTANCE.afterY");

        Label cleanup = new Label();

        Label finish = new Label();

        if (HeapSettings.conditional) {

            // STACK: [...|count|class|obj]
            visitCheck(mv,
                       cleanup);
            // STACK: [...|count|class|obj]

        }

        // STACK: [...|count|class|obj]
        mv.visitInsn(Opcodes.DUP_X2);
        // STACK: [...|obj|count|class|obj]
        mv.visitInsn(Opcodes.DUP_X2);
        // STACK: [...|obj|obj|count|class|obj]
        mv.visitInsn(Opcodes.POP);
        // STACK: [...|obj|obj|count|class]
        mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
                           "java/lang/Class",
                           "getName",
                           "()Ljava/lang/String;");
        // STACK: [...|obj|obj|count|type]
        mv.visitMethodInsn(Opcodes.INVOKESTATIC,
                           "com/foursquare/heapaudit/HeapUtil",
                           "record",
                           "(Ljava/lang/Object;[ILjava/lang/String;)V");
        // STACK: [...|obj]

        if (HeapSettings.conditional) {

            visitCleanup(mv,
                         cleanup,
                         finish);
            // STACK: [...|count|class|obj]
            mv.visitInsn(Opcodes.SWAP);
            // STACK: [...|count|obj|class]
            mv.visitInsn(Opcodes.POP);
            // STACK: [...|count|obj]
            mv.visitInsn(Opcodes.SWAP);
            // STACK: [...|obj|count]
            mv.visitInsn(Opcodes.POP);
            // STACK: [...|obj]
            visitFinish(mv,
                        finish);
            // STACK: [...|obj]

        }

    }

}