Decompile BEAM files to Elixir source code

What would the use case for this? Maybe there is a simpler way to achieve what you want?

You might find this helpful

The idea is to create a analysis tool that will work with AST of Elixir program

The problem is that the transformation from Elixir to BEAM bytecode loses information. A simple example:

a = 1
a = 2

will result in bytecode somewhat like

a = 1
a1= 2

Because rebinding variables isn’t possible in bytecode, so Elixir fakes it. There are plenty of such examples. Decompiling BEAM bytecode to Erlang is fairly straightforward and precise, but getting back to the original Elixir AST is, I think, almost impossible. The simpler solution would be to just stash the AST in a BEAM segment (the format is pretty extensible so while I’m not sure whether this is already happening somewhere, I’m sure it is not too hard to do this).

At the time you wrote this it seems that was already possible with Dbgi chunk, that you can see the pull request for it here, and get some more background from this 2017 Jose video:

But I may be misunderstanding something, because compilers and AST’s are not my thing

My project works with a lot of code but not all code:

I have also done some experiments with the BEAM file. See the little beam_file project.

With BeamFile you can create byte, erl, and elixir-code (with the limitation discussed here) from the beam file.

Example:

defmodule Example.Math do
  @moduledoc "Math is Fun"

  def add(number_a, number_b), do: number_a + number_b

  def odd_or_even(a) do
    if rem(a, 2) == 0 do
      :even
    else
      :odd
    end
  end
end

iex> {:ok, code} = BeamFile.elixir_code(Example.Math)
iex> IO.puts(code)
defmodule Elixir.Example.Math do
  @moduledoc """
  Math is Fun
  """

  def add(number_a, number_b) do
    :erlang.+(number_a, number_b)
  end

  def odd_or_even(a) do
    case(:erlang.==(:erlang.rem(a, 2), 0)) do
      false ->
        :odd

      true ->
        :even
    end
  end
end

Hello dear friends. hope you can help me.
I have some .beam files I want to decompile into .erl files (source code)
How can I do this. Please help me, I will thank you.

It depends on if the beam file includes the AST or not. Try this:

I believe there are some mechanisms in the compiler to turn the beam bytecode into Core Erlang if you just want to deduce the logic similar to an decompiler