Wasm Structs

Struct.ds

// Compile with `dsc Struct.ds -platform wasm -Wno-build`

public struct Vector2
{
    public int X;
    public int Y;

    public int LengthSquared()
    {
        return X * X + Y * Y;
    }
}

public module StructTest
{
    public int Allocate()
    {
        Vector2 val;
        val.X = 3;
        val.Y = 4;
        Vector2 copy = val;
        return copy.LengthSquared();
    }
}

Struct.wast

(module 
    (func
        $Vector2.LengthSquared
        (param $stacktop i32)
        (param $this i32)
        (result i32)
        (local $frameptr i32)
        (local $stackptr i32)
        (block
            (set_local $frameptr (get_local $stacktop))
            (set_local $stackptr (get_local $frameptr))
            (return
                (i32.add
                    (i32.mul
                        (i32.load (i32.add (get_local $this) (i32.const 0)))
                        (i32.load (i32.add (get_local $this) (i32.const 0))))
                    (i32.mul
                        (i32.load (i32.add (get_local $this) (i32.const 4)))
                        (i32.load (i32.add (get_local $this) (i32.const 4))))))))
    (func
        $StructTest.Allocate
        (param $stacktop i32)
        (result i32)
        (local $frameptr i32)
        (local $stackptr i32)
        (local $tmp0 i32)
        (local $tmp1 i32)
        (block
            (set_local $frameptr (get_local $stacktop))
            (set_local $stackptr (get_local $frameptr))
            (set_local $stackptr (i32.add (get_local $stackptr) (i32.const 16)))
            (i32.store (i32.add (get_local $frameptr) (i32.const 0)) (i32.const 3))
            (i32.store (i32.add (get_local $frameptr) (i32.const 4)) (i32.const 4))
            (set_local $tmp0 (i32.add (get_local $frameptr) (i32.const 8)))
            (set_local $tmp1 (i32.add (get_local $frameptr) (i32.const 0)))
            (i32.store
                (i32.add (get_local $tmp1) (i32.const 0))
                (i32.load (i32.add (get_local $tmp0) (i32.const 0))))
            (i32.store
                (i32.add (get_local $tmp1) (i32.const 4))
                (i32.load (i32.add (get_local $tmp0) (i32.const 4))))
            (return
                (call
                    $Vector2.LengthSquared
                    (get_local $stackptr)
                    (i32.add (get_local $frameptr) (i32.const 8))))))
)