Jasmin Assembler验证错误:期望在堆栈上找到对象/数组

Question

我在"java testphase"之后得到这个错误:

C:jasmin-2.4>java testphase
Exception in thread "main" java.lang.VerifyError: 
  (class: testphase, method: main signature: ([Ljava/lang/String;)V) 
  Expecting to find object/array on stack
  Could not find the main class: testphase. 
Program will exit.

代码:

.class public testphase
.super java/lang/Object
; standard initializer
.method public <init>()V
  aload_0
  invokenonvirtual java/lang/Object/<init>()V
  return
.end method
.method public static main([Ljava/lang/String;)V
  .limit stack 10
  .limit locals 3
  ; assign something
  iconst_1
  iconst_1
  iadd
  istore_1
 ; assign something
  iconst_2
  iconst_2
  isub
  istore_2
 ; Writeln
  getstatic java/lang/System/out Ljava/io/PrintStream;
  iload_1
  invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
  return
.end method

Answer 1

你有很多问题。

首先:你需要改变最后的

iload_1

aload_1

• 你正在加载String数组参数，所以不应该使用整数load (load)来加载。

第二，你正在加载一个String数组，而不是String。你需要选择你想要的元素。(如何解引用数组中的元素，请参阅aaload)

Answer 2

可以:

.class public testphase
.super java/lang/Object
; standard initializer
  .method public <init>()V
   aload_0
   invokenonvirtual java/lang/Object/<init>()V
   return
.end method
.method public static main([Ljava/lang/String;)V
  .limit stack 2
  .limit locals 3
  ; assign something
  iconst_1
  iconst_1
  iadd
  istore_1
  ; assign something
  iconst_2
  iconst_2
  isub
  istore_2
  ; Writeln
  getstatic java/lang/System/out Ljava/io/PrintStream;
  iload_1
  invokevirtual java/io/PrintStream/println(I)V
  ; Writeln variable 2
  getstatic java/lang/System/out Ljava/io/PrintStream;
  iload_2
  invokevirtual java/io/PrintStream/println(I)V
  return
.end method

基本变化包括System.out.println(int)的签名。