Semicompiled

package com.zarbosoft.semicompiled;

class Main {
  public static void myMain() {
    int x = 0;
    while (true) {
      x += 1;
      if (x == 3) {
        break;
      }
      x += 2;
    }
  }
}

Classfile /tmp/semicompiled-BiEoQy0X-2780055117974571815/com/zarbosoft/semicompiled/Main.class
  Last modified Jun 2, 2024; size 231 bytes
  MD5 checksum 5aed363e5cce6dbde29df6d2041d6b97
class com.zarbosoft.semicompiled.Main
  minor version: 0
  major version: 52
  flags: (0x0020) ACC_SUPER
  this_class: #2                          // com/zarbosoft/semicompiled/Main
  super_class: #3                         // java/lang/Object
  interfaces: 0, fields: 0, methods: 2, attributes: 0
Constant pool:
   #1 = Methodref          #3.#9          // java/lang/Object."<init>":()V
   #2 = Class              #10            // com/zarbosoft/semicompiled/Main
   #3 = Class              #11            // java/lang/Object
   #4 = Utf8               <init>
   #5 = Utf8               ()V
   #6 = Utf8               Code
   #7 = Utf8               myMain
   #8 = Utf8               StackMapTable
   #9 = NameAndType        #4:#5          // "<init>":()V
  #10 = Utf8               com/zarbosoft/semicompiled/Main
  #11 = Utf8               java/lang/Object
{
  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 myMain();
    descriptor: ()V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=0
         0: iconst_0
         1: istore_0
         2: iinc          0, 1
         5: iload_0
         6: iconst_3
         7: if_icmpne     13
        10: goto          19
        13: iinc          0, 2
        16: goto          2
        19: return
      StackMapTable: number_of_entries = 3
        frame_type = 252 /* append */
          offset_delta = 2
          locals = [ int ]
        frame_type = 10 /* same */
        frame_type = 5 /* same */
}

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, "myMain", "()V", null, null);
      methodVisitor.visitCode();
      methodVisitor.visitInsn(ICONST_0);
      methodVisitor.visitVarInsn(ISTORE, 0);
      Label label0 = new Label();
      methodVisitor.visitLabel(label0);
      methodVisitor.visitFrame(Opcodes.F_APPEND, 1, new Object[] {Opcodes.INTEGER}, 0, null);
      methodVisitor.visitIincInsn(0, 1);
      methodVisitor.visitVarInsn(ILOAD, 0);
      methodVisitor.visitInsn(ICONST_3);
      Label label1 = new Label();
      methodVisitor.visitJumpInsn(IF_ICMPNE, label1);
      Label label2 = new Label();
      methodVisitor.visitJumpInsn(GOTO, label2);
      methodVisitor.visitLabel(label1);
      methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
      methodVisitor.visitIincInsn(0, 2);
      methodVisitor.visitJumpInsn(GOTO, label0);
      methodVisitor.visitLabel(label2);
      methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
      methodVisitor.visitInsn(RETURN);
      methodVisitor.visitMaxs(2, 1);
      methodVisitor.visitEnd();
    }
    classWriter.visitEnd();

    return classWriter.toByteArray();
  }
}

Classfile /tmp/semicompiled-BiEoQy0X-2780055117974571815/com/zarbosoft/semicompiled/Main.class
  Last modified Jun 2, 2024; size 418 bytes
  MD5 checksum e096c16fd2c8a59b07335d56511ede81
  Compiled from "Main.java"
class com.zarbosoft.semicompiled.Main
  minor version: 0
  major version: 52
  flags: (0x0020) ACC_SUPER
  this_class: #2                          // com/zarbosoft/semicompiled/Main
  super_class: #3                         // java/lang/Object
  interfaces: 0, fields: 0, methods: 2, attributes: 1
Constant pool:
   #1 = Methodref          #3.#17         // java/lang/Object."<init>":()V
   #2 = Class              #18            // com/zarbosoft/semicompiled/Main
   #3 = Class              #19            // java/lang/Object
   #4 = Utf8               <init>
   #5 = Utf8               ()V
   #6 = Utf8               Code
   #7 = Utf8               LineNumberTable
   #8 = Utf8               LocalVariableTable
   #9 = Utf8               this
  #10 = Utf8               Lcom/zarbosoft/semicompiled/Main;
  #11 = Utf8               myMain
  #12 = Utf8               x
  #13 = Utf8               I
  #14 = Utf8               StackMapTable
  #15 = Utf8               SourceFile
  #16 = Utf8               Main.java
  #17 = NameAndType        #4:#5          // "<init>":()V
  #18 = Utf8               com/zarbosoft/semicompiled/Main
  #19 = Utf8               java/lang/Object
{
  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 3: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   Lcom/zarbosoft/semicompiled/Main;

  public static void myMain();
    descriptor: ()V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=0
         0: iconst_0
         1: istore_0
         2: iinc          0, 1
         5: iload_0
         6: iconst_3
         7: if_icmpne     13
        10: goto          19
        13: iinc          0, 2
        16: goto          2
        19: return
      LineNumberTable:
        line 5: 0
        line 6: 19
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            2      18     0     x   I
      StackMapTable: number_of_entries = 3
        frame_type = 252 /* append */
          offset_delta = 2
          locals = [ int ]
        frame_type = 10 /* same */
        frame_type = 5 /* same */
}
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(3, 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, "myMain", "()V", null, null);
      methodVisitor.visitCode();
      Label label0 = new Label();
      methodVisitor.visitLabel(label0);
      methodVisitor.visitLineNumber(5, label0);
      methodVisitor.visitInsn(ICONST_0);
      methodVisitor.visitVarInsn(ISTORE, 0);
      Label label1 = new Label();
      methodVisitor.visitLabel(label1);
      methodVisitor.visitFrame(Opcodes.F_APPEND, 1, new Object[] {Opcodes.INTEGER}, 0, null);
      methodVisitor.visitIincInsn(0, 1);
      methodVisitor.visitVarInsn(ILOAD, 0);
      methodVisitor.visitInsn(ICONST_3);
      Label label2 = new Label();
      methodVisitor.visitJumpInsn(IF_ICMPNE, label2);
      Label label3 = new Label();
      methodVisitor.visitJumpInsn(GOTO, label3);
      methodVisitor.visitLabel(label2);
      methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
      methodVisitor.visitIincInsn(0, 2);
      methodVisitor.visitJumpInsn(GOTO, label1);
      methodVisitor.visitLabel(label3);
      methodVisitor.visitLineNumber(6, label3);
      methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
      methodVisitor.visitInsn(RETURN);
      Label label4 = new Label();
      methodVisitor.visitLabel(label4);
      methodVisitor.visitLocalVariable("x", "I", null, label1, label4, 0);
      methodVisitor.visitMaxs(2, 1);
      methodVisitor.visitEnd();
    }
    classWriter.visitEnd();

    return classWriter.toByteArray();
  }
}