Kotlinx-llvm dev blog!

I’m working on a kotlin idomatic library around the llvm C api which is coming along really well actually. I’m also making a full fledged custom language and compiler to test it out.


I’m working on implementing my latest features which is function calls, and some instructions like the ptrtoint instruction and the load instruction. Besides that, there is a checklist in the repo for the things that have been done.

The brute test in LLVM.kt produces this:

; ModuleID = 'test'
source_filename = "test"
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc19.23.28106"

@testVar = global i32 10

declare i32 @printf(i8*, ...)

define i32 @add(i32, i32 %y) {
  %add_res = add i32 %0, %y
  ret i32 %add_res

define i32 @main() {
  %message = alloca [3 x i8]
  store [3 x i8] c"%d\00", [3 x i8]* %message
  %messageGEP_ref = getelementptr [3 x i8], [3 x i8]* %message, i32 0
  %addCallRes = alloca i32
  %addFuncCall = call i32 @add(i32 10, i32 10)
  store i32 %addFuncCall, i32* %addCallRes
  %gepCast = bitcast [3 x i8]* %messageGEP_ref to i8*
  %0 = load i32, i32* %addCallRes
  %call = call i32 (i8*, ...) @printf(i8* %gepCast, i32 %0)
  ret i32 0

And when built into an executable executes :smiley:

 //Compile the llvm bitcode
C:\projects\kotlinx-llvm (master -> origin)
λ llc test.bc

//Build the build binary object into an executable
C:\projects\kotlinx-llvm (master -> origin)
λ clang -o test.exe test.
test.bc   test.c    test.exe  test.ll   test.o    test.s
C:\projects\kotlinx-llvm (master -> origin)
λ clang -o test.exe test.s

//Run the generated executable
C:\projects\kotlinx-llvm (master -> origin)
λ test.exe

Right now, the default llvm passes inline a lot of the instructions so there are places where you would see a temporary variable made that references or loads the value of some pointer that actually get inlined, like in the @add(i32 10, i32 10), we are actually trying to load the value of @testVar but because @testVar is just a primitive integer literal, it gets inlined. I’ll be adding custom llvm passes soon enough.

The custom language should be usable minimally as a language soon once I get function calls to work properly. I’ve almost got it done, but I had recently discovered that my ANTLR parser grammar was inefficient and was crashing the intellij plugin :frowning: but I had fixed it and had made a significant improvement to the performance as told by the profiler (I’ll post about it tonight after I’m done with work). When I get the toylang to compile with function calls working, I’ll make a demo video and post here!


Just now I have finally implemented the new kotlinx-llvm features into the toylang compiler and was finally able to produce a binary of a more complex program.

let test = "Hello\n";

fn add(x: Int, y: Int): Int{
    return x + y;

fn main(argc: Int){
    println("%d\n", add(5, 6));
C:\projects\kotlinx-llvm\toylang\run (master -> origin)
λ llc -filetype=obj -o test.o test.bc

C:\projects\kotlinx-llvm\toylang\run (master -> origin)
λ clang -o test.exe test.o

C:\projects\kotlinx-llvm\toylang\run (master -> origin)
λ test.exe

Just a quick checklist of things:

  • Refactor toylang compiler so that the scope information is generated by the parsing visitor rather than a separate component
  • Add compilation support for string interpolation rather than just lexical/parsing support
  • Create dedicated passes for several complex mechanisms
    • Type Checking
    • String interpolation
    • Type Information (Classes, structs, properties, etc)
    • “Module Catenation” aka The unionizing of modules into one super module
    • Complex error handling
  • Add in structs
  • I want to make functions first classes and allow pure functions as a feature
  • Improve local variables

A note to make about this toylang is that this is not Beagle, this is simply an educational language that is designed with simplicity and to test kotlinx-llvm properly and show people how kotlinx-llvm can be used and more importantly show how a compiler can be made.


This link seems broken for me

Fixed! Thank you! The problem was that the link didn’t have the branch in the url oops

Im curious how do you get the following outputs in your powershell?

C:\projects\kotlinx-llvm\toylang\run (master -> origin)
λ test.exe

(The lambda prompt :slight_smile: in the last command, im assuming the first one has something to do with git)

Could you please share a link or some information?

It’s a program called cmder. It’s a terminal/cmd emulator!

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