关于这个指令的 BootstrapMethods 属性，我看了官方文档：
https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.7.21
但是里面没有详细介绍 bootstrap_arguments，有点不太明白，想请教一下，这个 bootstrap 方法的参数列表是做啥的呢？
我个人的理解是，单纯的支持 lambda 表达式，拿 runnable 来说，第二个参数对应的是生成的目标方法，第一个参数与第三个参数是一样的，所以不太明白为啥会有两个，它们的作用是啥？

Tests in error:
test_fis(com.gxk.jvm.builtin.JavaIoTest)

Test success after deleting the method.（Jvm-core/src/test/java/com.gxk.jvm.builtin.JavaIoTest.test_fis）

Hi, you wrote an issue on my project on gitlab (Metacircular JVM in pure Java https://gitlab.com/neoexpert/jvm ). I wisch you success in your project too :-)
maybe we can cooperate. Maybe your JVM could run on my JVM and vice versa. It woult be awesome.

On my Linux machine JAVA_HOME is not set, the JVM crashes with following error:

$ java -jar jvm-core/target/mini-jvm.jar -jar jvm-core/target/mini-jvm.jar -jar test.jar
Exception in thread "main" java.lang.IllegalStateException: must set env JAVA_HOME
        at com.gxk.jvm.util.Utils.classpath(Utils.java:263)           at com.gxk.jvm.VirtualMachine.run(VirtualMachine.java:58)                                                                   at com.gxk.jvm.Main.main(Main.java:28)

Maybe you can use my JVMTest.java Application which tests every Bytecode-Instruction (except INVOKEDYNAMIC):
https://gitlab.com/neoexpert/jvm/-/blob/184d80e18d6cfb130146604ea3f02f64f2843654/JVMTest.java

When your JVM can run this, then it is almost complete.

您好，在执行如以下包含classloader代码时，mini-jvm好像无法解析。

    try {
      Class cls = Class.forName("TestClass");
      cl = cls.getClassLoader();
      cl.getResource("name");
    } catch (Exception e) { 
      System.out.println(-1);
    }

报错如下所示：

Exception in thread "main" java.lang.NullPointerException
	at com.gxk.jvm.instruction.references.InvokeVirtualInst.execute(InvokeVirtualInst.java:80)
	at com.gxk.jvm.interpret.Interpreter.execute(Interpreter.java:53)
	at com.gxk.jvm.interpret.Interpreter.runMain(Interpreter.java:77)
	at com.gxk.jvm.VirtualMachine.run(VirtualMachine.java:79)
	at com.gxk.jvm.Main.main(Main.java:24)

1. 编写测试用例
   e.g

import java.util.*;

public class testMap {

    public static void main(String[] args){

    Map map = new HashMap<>();
    map.put("a", 12);

    System.out.println(map.get("a"));

    }
}

2.以 mini-jvm 运行, 判定结果是否符合预期.
3.若符合预期, 提交 PR.
4.若不合预期, 尝试修复, 若碰到问题, 评论即可.

提供
stop in [clazz] [method]
e.g ``` stop in java.lang.Object toString
操作.

运行到指定方法时, 中止运行以供调试.

Interceptor.java

public void doInterpret(Thread thread, Frame frame) {
thread.pushFrame(frame);
KClass clazz = frame.method.clazz;
if (clazz != null) {
// super clazz static interfaceInit
KClass superClazz = clazz.getUnStaticInitSuperClass();

clazz.name = "HelloWorld"
superClazz.name = "HelloWorld"

感觉 superClazz 的逻辑意义 和 实际扮演的角色 不符吧

通过测试案例

interface Interface {
  void doSomething();
  void somethingElse(String arg);
}

class RealObject implements Interface {
  @Override
  public void doSomething() {
    System.out.println("doSomething");
  }
  @Override
  public void somethingElse(String arg) {
    System.out.println("somethingElse " + arg);
  }
}


class DynamicProxyHandler implements InvocationHandler {
  private Object proxied;
  DynamicProxyHandler(Object proxied) {
    this.proxied = proxied;
  }
  @Override
  public Object
  invoke(Object proxy, Method method, Object[] args)
  throws Throwable {
    System.out.println(
      "**** proxy: " + proxy.getClass() +
      ", method: " + method + ", args: " + args);
    if(args != null)
      for(Object arg : args)
        System.out.println("  " + arg);
    return method.invoke(proxied, args);
  }
}

class SimpleDynamicProxy {
  public static void consumer(Interface iface) {
    iface.doSomething();
    iface.somethingElse("bonobo");
  }
  public static void main(String[] args) {
    RealObject real = new RealObject();
    consumer(real);
    // Insert a proxy and call again:
    Interface proxy = (Interface)Proxy.newProxyInstance(
      Interface.class.getClassLoader(),
      new Class[]{ Interface.class },
      new DynamicProxyHandler(real));
    consumer(proxy);
  }
}

=>

doSomething
somethingElse bonobo
SimpleProxy doSomething
doSomething
SimpleProxy somethingElse bonobo
somethingElse bonobo

1. 编写测试用例
   e.g

import java.util.ArrayList;
public class TestArrayList {
  public static void main(String[] args) {
      ArrayList<String> list = new ArrayList<>(2);
      list.add("1");
      list.add("2");
      
      int size = list.size();
      String l1 = list.get(0);
      
      System.out.println(size);
      System.out.println(l1);
  }
}

2. 以 mini-jvm 运行, 判定结果是否符合预期.
3. 若符合预期, 提交 PR.
4. 若不合预期, 尝试修复, 若碰到问题, 评论即可.

测试通过 类型信息 示例代码

`public class IfICmpEqInst implements Instruction {
public final int offset;

public IfICmpEqInst(int offset) {
this.offset = offset;
}

@OverRide
public int offset() {
return 3;
}

@OverRide
public void execute(Frame frame) {
Integer val2= frame.popInt();
Integer val1= frame.popInt();
### if (val1 == val2) { //Objects.equals(val1, val2)
frame.nextPc = frame.thread.getPc() + offset;
}
}
}
`

执行同一个程序, 基于 mini-jvm 的不报错, 基于 mini-jvm 的 mini-jvm 报错
master:mini-jvm jerry$ javac Test06LoadRefEachOther.java
master:mini-jvm jerry$ java -jar jvm-core/target/mini-jvm.jar -cp . Test06LoadRefEachOther
1
1
master:mini-jvm jerry$ java -jar jvm-core/target/mini-jvm.jar -jar jvm-core/target/mini-jvm.jar -cp . Test06LoadRefEachOther
java.lang.ArrayIndexOutOfBoundsException: 256
at com.gxk.jvm.instruction.AAStoreInst.execute(AAStoreInst.java:13)
at com.gxk.jvm.interpret.Interpreter.loop(Interpreter.java:119)
at com.gxk.jvm.interpret.Interpreter.doInterpret(Interpreter.java:75)
at com.gxk.jvm.interpret.Interpreter.interpret(Interpreter.java:45)
at com.gxk.jvm.VirtualMachine.run(VirtualMachine.java:74)
at com.gxk.jvm.Main.main(Main.java:23)
com/gxk/jvm/instruction/CAStoreInst.execute(CAStoreInst.java:13)
Exception in thread "main" java.lang.IllegalStateException
at com.gxk.jvm.interpret.Interpreter.loop(Interpreter.java:126)
at com.gxk.jvm.interpret.Interpreter.doInterpret(Interpreter.java:75)
at com.gxk.jvm.interpret.Interpreter.interpret(Interpreter.java:45)
at com.gxk.jvm.VirtualMachine.run(VirtualMachine.java:74)
at com.gxk.jvm.Main.main(Main.java:23)
master:mini-jvm jerry$

测试用例如下
/**

• LoadRefEachOther
• @author Jerry.X.He [email protected]
• @Version 1.0
• @Date 2020-03-08 10:58
  */
  public class Test06LoadRefEachOther {

// Test06LoadRefEachOther
// refer : https://hllvm-group.iteye.com/group/topic/38847
public static void main(String[] args) {

System.out.println(Clazz1.x1);

// System.out.println(Clazz2.x1);
System.out.println(Clazz2.x2);

}

/**

• Clazz1
• @author Jerry.X.He [email protected]
• @Version 1.0
• @Date 2020-03-08 10:59
  */
  private static class Clazz1 {
  static int x1 = 1;
  static {
  x1 = Clazz2.x2;
  }
  }

/**

• Clazz2
• @author Jerry.X.He [email protected]
• @Version 1.0
• @Date 2020-03-08 11:00
  */
  private static class Clazz2 extends Clazz1 {
  static int x2 = 2;
  static {
  x2 = Clazz1.x1;
  }
  }

}

... 放到这里 感觉有点别扭呀, 和规范 描述的差距太大了, 另外 放在这里 感觉还是有点不合适

master:mini-jvm jerry$ java -jar jvm-core/target/mini-jvm.jar -jar jvm-core/target/mini-jvm.jar -cp . HelloWorld
HelloWorldSuper
HelloWorldSuper
hello world

HelloWorld.java
public class HelloWorld extends HelloWorldSuper {
// static {
// System.out.println("");
// }
public static void main(String[] args) {
System.out.println("hello world");
}
}

HelloWorldSuper.java
public class HelloWorldSuper {
static {
System.out.println("HelloWorldSuper ");
}
}

LookupSwitchInst
TableSwitchInst

实现

支持启动可执行 jar

stop at : -- 在行中设置断点