simmsb / a-compiler Goto Github PK

Hi, when writing programs and compiling with this compiler, I have found that it is possible to declare functions returning arrays.
For example:

fn a() -> [u1@4] {
	return {1, 2, 3, 4};
}

fn main() {
	var x := a();

	std.printf("%u1 %u1 %u1 %u1\n", x[0], x[1], x[2], x[3]);
}

This appears to function, presumably because the size of the array 1 * 4 fits into a register size.

However, the following:

fn a() -> [u1@5] {
	return {1, 2, 3, 4};
}

fn main() {
	var x := a();

	std.printf("%u1 %u1 %u1 %u1\n", x[0], x[1], x[2], x[3]);
}

(Note the array size changed to 5)

Produces an assertion exception:

~/dev/wewcompiler/objects/base.py", line 551, in get_register
    assert size in (1, 2, 4, 8)
AssertionError

After looking through your code it seems like the best place to apply a fix would be here:

https://github.com/nitros12/A-Compiler/blob/61783d3072015927b38e8293e2a0a3333c017229/wewcompiler/objects/types.py#L198-L200

This shouldn't compile:

var a := {x, y}; // this should fail to typecheck
fn x(l: u8, b: s4, n: *u8) {}
fn y() -> u8 {}
fn main() {}

Function types shouldn't implicitly cast, if they are (or are we even checking?)

Also edit array variables to yield pointer to array types but still have the size of arrays.
Make sure that pointers cannot cast to arrays.