HeapANEWARRAY.java

package com.foursquare.heapaudit;

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

class HeapANEWARRAY extends HeapUtil {

    // Allocations by ANEWARRAY are triggered via calls to visitTypeInsn where
    // the top of the stack contains the number of elements in the array and
    // returns a reference to the newly allocated array object.

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

        log(debug,
            trace,
            mv,
            "\tANEWARRAY.before(" + type + ")");

        // STACK: [...|count]
        mv.visitInsn(Opcodes.DUP);
        // STACK: [...|count|count]

    }

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

        log(debug,
            trace,
            mv,
            "\tANEWARRAY.after(" + type + ")");

        Label cleanup = new Label();

        Label finish = new Label();

        if (HeapSettings.conditional) {

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

        }

        // STACK: [...|count|obj]
        mv.visitInsn(Opcodes.DUP_X1);
        // STACK: [...|obj|count|obj]
        mv.visitInsn(Opcodes.SWAP);
        // STACK: [...|obj|obj|count]
        mv.visitLdcInsn(type);
        // 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|obj]
            mv.visitInsn(Opcodes.SWAP);
            // STACK: [...|obj|count]
            mv.visitInsn(Opcodes.POP);
            // STACK: [...|obj]
            visitFinish(mv,
                        finish);
            // STACK: [...|obj]

        }

    }

}