Semicompiled

package com.zarbosoft.semicompiled;

import java.lang.String;
import java.lang.System;

class Main {
  public static void main(String[] args) {
    System.out.println("Hello world");
  }
}

Classfile /tmp/semicompiled-5mKIlBrv-10511982186200349085/com/zarbosoft/semicompiled/Main.class
  Last modified Jun 2, 2024; size 398 bytes
  MD5 checksum b42da5109a3d91aa768b48dab9808800
class com.zarbosoft.semicompiled.Main
  minor version: 0
  major version: 52
  flags: (0x0020) ACC_SUPER
  this_class: #5                          // com/zarbosoft/semicompiled/Main
  super_class: #6                         // java/lang/Object
  interfaces: 0, fields: 0, methods: 2, attributes: 0
Constant pool:
   #1 = Methodref          #6.#14         // java/lang/Object."<init>":()V
   #2 = Fieldref           #15.#16        // java/lang/System.out:Ljava/io/PrintStream;
   #3 = String             #17            // Hello world
   #4 = Methodref          #18.#19        // java/io/PrintStream.println:(Ljava/lang/String;)V
   #5 = Class              #20            // com/zarbosoft/semicompiled/Main
   #6 = Class              #21            // java/lang/Object
   #7 = Utf8               <init>
   #8 = Utf8               ()V
   #9 = Utf8               Code
  #10 = Utf8               main
  #11 = Utf8               ([Ljava/lang/String;)V
  #12 = Utf8               MethodParameters
  #13 = Utf8               args
  #14 = NameAndType        #7:#8          // "<init>":()V
  #15 = Class              #22            // java/lang/System
  #16 = NameAndType        #23:#24        // out:Ljava/io/PrintStream;
  #17 = Utf8               Hello world
  #18 = Class              #25            // java/io/PrintStream
  #19 = NameAndType        #26:#27        // println:(Ljava/lang/String;)V
  #20 = Utf8               com/zarbosoft/semicompiled/Main
  #21 = Utf8               java/lang/Object
  #22 = Utf8               java/lang/System
  #23 = Utf8               out
  #24 = Utf8               Ljava/io/PrintStream;
  #25 = Utf8               java/io/PrintStream
  #26 = Utf8               println
  #27 = Utf8               (Ljava/lang/String;)V
{
  com.zarbosoft.semicompiled.Main();
    descriptor: ()V
    flags: (0x0000)
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: return

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
         3: ldc           #3                  // String Hello world
         5: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
         8: return
    MethodParameters:
      Name                           Flags
      args
}

package asm.com.zarbosoft.semicompiled;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.ConstantDynamic;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.RecordComponentVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.TypePath;

public class MainDump implements Opcodes {

  public static byte[] dump() throws Exception {

    ClassWriter classWriter = new ClassWriter(0);
    FieldVisitor fieldVisitor;
    RecordComponentVisitor recordComponentVisitor;
    MethodVisitor methodVisitor;
    AnnotationVisitor annotationVisitor0;

    classWriter.visit(
        V1_8, ACC_SUPER, "com/zarbosoft/semicompiled/Main", null, "java/lang/Object", null);

    {
      methodVisitor = classWriter.visitMethod(0, "<init>", "()V", null, null);
      methodVisitor.visitCode();
      methodVisitor.visitVarInsn(ALOAD, 0);
      methodVisitor.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
      methodVisitor.visitInsn(RETURN);
      methodVisitor.visitMaxs(1, 1);
      methodVisitor.visitEnd();
    }
    {
      methodVisitor =
          classWriter.visitMethod(
              ACC_PUBLIC | ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
      methodVisitor.visitParameter("args", 0);
      methodVisitor.visitCode();
      methodVisitor.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
      methodVisitor.visitLdcInsn("Hello world");
      methodVisitor.visitMethodInsn(
          INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
      methodVisitor.visitInsn(RETURN);
      methodVisitor.visitMaxs(2, 1);
      methodVisitor.visitEnd();
    }
    classWriter.visitEnd();

    return classWriter.toByteArray();
  }
}

Classfile /tmp/semicompiled-5mKIlBrv-10511982186200349085/com/zarbosoft/semicompiled/Main.class
  Last modified Jun 2, 2024; size 599 bytes
  MD5 checksum b57ff49136920a5f5f2a9a254c279978
  Compiled from "Main.java"
class com.zarbosoft.semicompiled.Main
  minor version: 0
  major version: 52
  flags: (0x0020) ACC_SUPER
  this_class: #5                          // com/zarbosoft/semicompiled/Main
  super_class: #6                         // java/lang/Object
  interfaces: 0, fields: 0, methods: 2, attributes: 1
Constant pool:
   #1 = Methodref          #6.#21         // java/lang/Object."<init>":()V
   #2 = Fieldref           #22.#23        // java/lang/System.out:Ljava/io/PrintStream;
   #3 = String             #24            // Hello world
   #4 = Methodref          #25.#26        // java/io/PrintStream.println:(Ljava/lang/String;)V
   #5 = Class              #27            // com/zarbosoft/semicompiled/Main
   #6 = Class              #28            // java/lang/Object
   #7 = Utf8               <init>
   #8 = Utf8               ()V
   #9 = Utf8               Code
  #10 = Utf8               LineNumberTable
  #11 = Utf8               LocalVariableTable
  #12 = Utf8               this
  #13 = Utf8               Lcom/zarbosoft/semicompiled/Main;
  #14 = Utf8               main
  #15 = Utf8               ([Ljava/lang/String;)V
  #16 = Utf8               args
  #17 = Utf8               [Ljava/lang/String;
  #18 = Utf8               MethodParameters
  #19 = Utf8               SourceFile
  #20 = Utf8               Main.java
  #21 = NameAndType        #7:#8          // "<init>":()V
  #22 = Class              #29            // java/lang/System
  #23 = NameAndType        #30:#31        // out:Ljava/io/PrintStream;
  #24 = Utf8               Hello world
  #25 = Class              #32            // java/io/PrintStream
  #26 = NameAndType        #33:#34        // println:(Ljava/lang/String;)V
  #27 = Utf8               com/zarbosoft/semicompiled/Main
  #28 = Utf8               java/lang/Object
  #29 = Utf8               java/lang/System
  #30 = Utf8               out
  #31 = Utf8               Ljava/io/PrintStream;
  #32 = Utf8               java/io/PrintStream
  #33 = Utf8               println
  #34 = Utf8               (Ljava/lang/String;)V
{
  com.zarbosoft.semicompiled.Main();
    descriptor: ()V
    flags: (0x0000)
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: return
      LineNumberTable:
        line 6: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   Lcom/zarbosoft/semicompiled/Main;

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
         3: ldc           #3                  // String Hello world
         5: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
         8: return
      LineNumberTable:
        line 8: 0
        line 9: 8
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       9     0  args   [Ljava/lang/String;
    MethodParameters:
      Name                           Flags
      args
}
SourceFile: "Main.java"

package asm.com.zarbosoft.semicompiled;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.ConstantDynamic;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.RecordComponentVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.TypePath;

public class MainDump implements Opcodes {

  public static byte[] dump() throws Exception {

    ClassWriter classWriter = new ClassWriter(0);
    FieldVisitor fieldVisitor;
    RecordComponentVisitor recordComponentVisitor;
    MethodVisitor methodVisitor;
    AnnotationVisitor annotationVisitor0;

    classWriter.visit(
        V1_8, ACC_SUPER, "com/zarbosoft/semicompiled/Main", null, "java/lang/Object", null);

    classWriter.visitSource("Main.java", null);

    {
      methodVisitor = classWriter.visitMethod(0, "<init>", "()V", null, null);
      methodVisitor.visitCode();
      Label label0 = new Label();
      methodVisitor.visitLabel(label0);
      methodVisitor.visitLineNumber(6, label0);
      methodVisitor.visitVarInsn(ALOAD, 0);
      methodVisitor.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
      methodVisitor.visitInsn(RETURN);
      Label label1 = new Label();
      methodVisitor.visitLabel(label1);
      methodVisitor.visitLocalVariable(
          "this", "Lcom/zarbosoft/semicompiled/Main;", null, label0, label1, 0);
      methodVisitor.visitMaxs(1, 1);
      methodVisitor.visitEnd();
    }
    {
      methodVisitor =
          classWriter.visitMethod(
              ACC_PUBLIC | ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
      methodVisitor.visitParameter("args", 0);
      methodVisitor.visitCode();
      Label label0 = new Label();
      methodVisitor.visitLabel(label0);
      methodVisitor.visitLineNumber(8, label0);
      methodVisitor.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
      methodVisitor.visitLdcInsn("Hello world");
      methodVisitor.visitMethodInsn(
          INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V", false);
      Label label1 = new Label();
      methodVisitor.visitLabel(label1);
      methodVisitor.visitLineNumber(9, label1);
      methodVisitor.visitInsn(RETURN);
      Label label2 = new Label();
      methodVisitor.visitLabel(label2);
      methodVisitor.visitLocalVariable("args", "[Ljava/lang/String;", null, label0, label2, 0);
      methodVisitor.visitMaxs(2, 1);
      methodVisitor.visitEnd();
    }
    classWriter.visitEnd();

    return classWriter.toByteArray();
  }
}