Kompiler is a compiler for the Kode programming language written in Kotlin. It translates a simple, statically typed language into WebAssembly (WASM) via LLVM IR with multiple optimization passes.

Kompiler demonstrates how a compiler works:

1. Lexing & Parsing → Abstract Syntax Tree (AST)
2. Semantic Analysis → Type checking
3. Code Generation → LLVM IR
4. Optimization → mem2reg (SSA promotion), function inlining
5. Backend → WebAssembly bytecode

The project prioritizes education and experimentation with real compiler techniques.

Kompiler consists of several pipeline stages:

• Parser → Grammar-based parsing with custom recursive descent
• Type Checker → Static type analysis and error reporting
• Codegen → LLVM IR generation with an SSA form
• Optimization Passes → mem2reg, inlining (with visualization support)
• WASM Backend → Direct LLVM IR to WebAssembly compilation (no LLVM dependency)

alien fun print_int{ x: i32 }: void;

fun add{ a: i32, b: i32 }: i32 (
    a + b;
);

fun main{}: i32 (
    i32 result = add{ 2, 3 };
    print_int{ result };
    0;
);

./gradlew run --args="example.kode"
# Compiles to build/out/example.wasm

./gradlew run --args="example.kode --run"
# Compiles and executes using Node.js

./gradlew run --args="example.kode --print-opt"
# Shows IR before and after each optimization pass

# Disable specific optimizations
./gradlew run --args="example.kode --no-mem2reg --no-inline"

# Print WebAssembly text format (requires wabt)
./gradlew run --args="example.kode --print-wasm"

# Combine options
./gradlew run --args="example.kode --print-opt --run"

The examples/opt/ directory contains programs demonstrating different optimizations:

# See mem2reg optimization in action
./gradlew run --args="examples/opt/1_mem2reg_simple.kode --print-opt"

# Compare with optimization disabled
./gradlew run --args="examples/opt/1_mem2reg_simple.kode --print-opt --no-mem2reg"

# See function inlining
./gradlew run --args="examples/opt/3_inlining_simple.kode --print-opt"

# See nested inlining (square calls multiply, both get inlined)
./gradlew run --args="examples/opt/4_inlining_nested.kode --print-opt"

Usage: kompiler <path-to-file> [options]

Options:
  --run           Run the compiled WebAssembly after compilation
  --no-mem2reg    Disable mem2reg optimization (alloca to SSA promotion)
  --no-inline     Disable function inlining optimization
  --print-opt     Print IR visualization before/after each optimization pass
  --print-wasm    Print generated WebAssembly text format (requires wabt/wasm2wat)
  -h, --help      Show this help message

Developed as part of a NIE-GEN (Code Generators) course project. The goal is to learn compiler design hands-on.