GL3

GL3 is an LLVM-based compiler for a systems programming language. The compiler is written in Go and uses the go-llvm bindings for code generation.

GL3 makes deliberate design choices that differ from many modern languages:

No Type Inference - All types must be explicitly specified. Variables require type annotations, and literals carry type suffixes. This eliminates ambiguity and makes the programmer's intentions explicit in the code.

No Array Types - Arrays are always a pointer to their elements, so sizes never become part of a type and there's no array-to-pointer decay to reason about. Use the arrays standard library module for growable arrays. When you need fixed-size memory without the heap, such as in an OS kernel before an allocator exists, __salloc from the intrinsics module allocates it on the stack.

The compiler uses LLVM to generate an object file for each module, then links them into a native executable using clang. Clang is required for linking.

• Go >=1.25.5
• LLVM 22 development libraries
• Clang (tested with version 22.1.1)

make

This builds the gl3 compiler binary, with the stdlib builtin modules embedded in it. You can remove the binary using make clean.

import "io"
import "ralloc"
import "strings"

struct Node {
    char* name
    Node* next
}

fnc main() -> int32 {
    def Node* a = malloc(sizeof Node) as Node*
    def Node* b = malloc(sizeof Node) as Node*

    a.name = dynstr("alice")
    a.next = b
    b.name = dynstr("bob")
    b.next = (0 as Node*)

    def Node* cur = a
    while (cur as int) != 0 {
        println("hello, %s", cur.name)
        cur = cur.next
    }

    str_free(a.name)
    str_free(b.name)
    free(a)
    free(b)
    return 0i32
}

./gl3 build example.gl3 -o output
./output

• SYNTAX.md - Complete language syntax reference
• STDLIB.md - Standard library documentation
• CLI.md - Command line interface reference