Luau Decompiler (for bytecode version 3)

[atrexus]

I am not sure if this is the right place to post this, but I have been working on a Luau decompiler and thought it would be a cool idea to share it on the official Luau discussion board. It's written in .NET and required an extensive understanding of the Luau bytecode format.

The latest source code is available here (v0.0.3-alpha). I would love some feedback!

[strawbberrys]

I just tested this simple script and here was the result for anyone wondering:

Input (compiled on optimization level 0)

local message = "Hello"
local time = os.clock()

print(`message {time}`)

Output

-- Unluau v0.0.2-alpha guid: 6d3eda7a-9fdf-4e32-b157-df2653ded023
local "Hello" = "Hello"
local var3 = os.clock()
local var6 = "message %*":format(var3)
print(var6)

Obviously it's in beta but I only see two issues so far which are the quotations around the variable naming and how the var numbers don't really make sense. Converting the %* string format into the string interpolation format would leave a cleaner output as well, but it would function the same way. I can try with a larger script later but it looks decent right now.

[strawbberrys]

I also get this error a lot with almost any script I put in.
Unluau -> Deserializer encountered NOP (no operation) instruction. Unable to proceed.

[atrexus]

Hey @strawbberrys! thanks for taking a look at my project, I greatly appreciate it. As you can see from the header in the script that you decompiled, you used v0.0.2-alpha which, I must say, is extremely buggy. Try the same script on v0.0.3-alpha the more stable counterpart.

This was the output for my decompilation (I used the identical input script):

print("message %*":format(os.clock()))

I will work on adding a setting in the decompiler for string interpolation preference. I hope you continue to play around Unluau and feel free to create an issue if anything like this persists!

[atrexus]

@strawbberrys I just added string interpolation. The latest release will return the following:

print(`message {os.clock()}`)

If you prefer the version with string.format then you can disable string interpolation in the decompiler options.

[strawbberrys]

@societall Awesome, tested and confirmed it works. It is automatically disabled though, just had to pass the --string-interpolation arg.