BytecodeListing.java:34-38: Decompile Bytecode Listing....

[0pdd]

The puzzle 845-380c5294 from #845 has to be resolved:

jeo-maven-plugin/src/main/java/org/eolang/jeo/representation/BytecodeListing.java

Lines 34 to 38 in 3636715

	* @todo #845:90min Decompile Bytecode Listing.
	* Currently we print bytecode listing to XMIR without decompiling it.
	* It's just raw, but human-readable bytecode.
	* We can make one step forward and try to decompile this code to Java.
	* This would be a great improvement for readability of this listing.

The puzzle was created by volodya-lombrozo on 13-Nov-24.

Estimate: 90 minutes, role: DEV.

If you have any technical questions, don't ask me, submit new tickets instead. The task will be "done" when the problem is fixed and the text of the puzzle is removed from the source code. Here is more about PDD and about me.

[h1alexbel]

@volodya-lombrozo can I take this?

[volodya-lombrozo]

@h1alexbel sure! Please, go ahead.

[h1alexbel]

@volodya-lombrozo should we decompile bytecode listing obtained after ASM transformation? For instance, this is the listing for MethodByte.class:

// class version 55.0 (55)
// access flags 0x21
public class org/eolang/jeo/MethodByte {

  // compiled from: MethodByte.java

  // access flags 0x1
  public <init>()V
   L0
    LINENUMBER 3 L0
    ALOAD 0
    INVOKESPECIAL java/lang/Object.<init> ()V
    RETURN
    MAXSTACK = 1
    MAXLOCALS = 1

  // access flags 0x9
  public static main([Ljava/lang/String;)V
   L0
    LINENUMBER 5 L0
    GETSTATIC java/lang/System.out : Ljava/io/PrintStream;
    INVOKESTATIC org/eolang/jeo/MethodByte.method ()B
    INVOKEVIRTUAL java/io/PrintStream.println (I)V
   L1
    LINENUMBER 6 L1
    GETSTATIC java/lang/System.out : Ljava/io/PrintStream;
    LDC "passed"
    INVOKEVIRTUAL java/io/PrintStream.println (Ljava/lang/String;)V
   L2
    LINENUMBER 7 L2
    RETURN
    MAXSTACK = 2
    MAXLOCALS = 1

  // access flags 0x8
  static method()B
   L0
    LINENUMBER 9 L0
    BIPUSH 52
    IRETURN
    MAXSTACK = 1
    MAXLOCALS = 0
}

or we should decompile the original bytecode instead? This is original MethodByte.class:

package org.eolang.jeo;

public class MethodByte {
    public MethodByte() {
    }

    public static void main(String[] var0) {
        System.out.println(method());
        System.out.println("passed");
    }

    static byte method() {
        return 52;
    }
}

[h1alexbel]

@volodya-lombrozo Also, I think we can maintain both listings: <listing/> (bytecode listing), and <decompiled/> (decompiled Java code). WDYT?

[volodya-lombrozo]

@h1alexbel I've already added bytecode listing, as you can see. The purpose of this issue is to try to decompile it to a Java, or at least to try it. We can do it by using https://github.com/fesh0r/fernflower or https://github.com/Storyyeller/Krakatau, or something else.

As for <decompiled/>, we just can't add it, we are limited by XMIR format that allows only <listing/>.