Restructure and compartmentalize the project

codegen/luau/src/analyzer/as_symbol.rs

@@ -0,0 +1,36 @@
+use wasm_ast::node::{BinOpType, CmpOpType};
+
+pub trait AsSymbol {
+	fn as_symbol(&self) -> Option<&'static str>;
+}
+
+impl AsSymbol for BinOpType {
+	fn as_symbol(&self) -> Option<&'static str> {
+		let result = match self {
+			Self::Add_FN => "+",
+			Self::Sub_FN => "-",
+			Self::Mul_FN => "*",
+			Self::Div_FN => "/",
+			Self::RemS_I32 | Self::RemU_I32 => "%",
+			_ => return None,
+		};
+
+		Some(result)
+	}
+}
+
+impl AsSymbol for CmpOpType {
+	fn as_symbol(&self) -> Option<&'static str> {
+		let result = match self {
+			Self::Eq_I32 | Self::Eq_FN => "==",
+			Self::Ne_I32 | Self::Ne_FN => "~=",
+			Self::LtU_I32 | Self::Lt_FN => "<",
+			Self::GtU_I32 | Self::Gt_FN => ">",
+			Self::LeU_I32 | Self::Le_FN => "<=",
+			Self::GeU_I32 | Self::Ge_FN => ">=",
+			_ => return None,
+		};
+
+		Some(result)
+	}
+}

codegen/luau/src/analyzer/br_table.rs

@@ -0,0 +1,29 @@
+use std::collections::HashMap;
+
+use wasm_ast::{
+	node::{BrTable, FuncData},
+	visit::{Driver, Visitor},
+};
+
+struct Visit {
+	id_map: HashMap<usize, usize>,
+}
+
+impl Visitor for Visit {
+	fn visit_br_table(&mut self, table: &BrTable) {
+		let id = table as *const _ as usize;
+		let len = self.id_map.len() + 1;
+
+		self.id_map.insert(id, len);
+	}
+}
+
+pub fn visit(ast: &FuncData) -> HashMap<usize, usize> {
+	let mut visit = Visit {
+		id_map: HashMap::new(),
+	};
+
+	ast.accept(&mut visit);
+
+	visit.id_map
+}

codegen/luau/src/analyzer/localize.rs

@@ -0,0 +1,94 @@
+use std::collections::BTreeSet;
+
+use parity_wasm::elements::ValueType;
+use wasm_ast::{
+	node::{BinOp, CmpOp, FuncData, LoadAt, MemoryGrow, MemorySize, StoreAt, UnOp, Value},
+	visit::{Driver, Visitor},
+};
+
+use super::as_symbol::AsSymbol;
+
+struct Visit {
+	local_set: BTreeSet<(&'static str, &'static str)>,
+	memory_set: BTreeSet<usize>,
+}
+
+impl Visitor for Visit {
+	fn visit_load_at(&mut self, v: &LoadAt) {
+		let name = v.load_type().as_name();
+
+		self.memory_set.insert(0);
+		self.local_set.insert(("load", name));
+	}
+
+	fn visit_store_at(&mut self, v: &StoreAt) {
+		let name = v.store_type().as_name();
+
+		self.memory_set.insert(0);
+		self.local_set.insert(("store", name));
+	}
+
+	fn visit_value(&mut self, v: &Value) {
+		let name = match v {
+			Value::I64(0) => "K_ZERO",
+			Value::I64(1) => "K_ONE",
+			Value::I64(_) => "from_u32",
+			_ => return,
+		};
+
+		self.local_set.insert(("i64", name));
+	}
+
+	fn visit_un_op(&mut self, v: &UnOp) {
+		let name = v.op_type().as_name();
+
+		self.local_set.insert(name);
+	}
+
+	fn visit_bin_op(&mut self, v: &BinOp) {
+		if v.op_type().as_symbol().is_some() {
+			return;
+		}
+
+		let name = v.op_type().as_name();
+
+		self.local_set.insert(name);
+	}
+
+	fn visit_cmp_op(&mut self, v: &CmpOp) {
+		if v.op_type().as_symbol().is_some() {
+			return;
+		}
+
+		let name = v.op_type().as_name();
+
+		self.local_set.insert(name);
+	}
+
+	fn visit_memory_size(&mut self, m: &MemorySize) {
+		self.memory_set.insert(m.memory());
+	}
+
+	fn visit_memory_grow(&mut self, m: &MemoryGrow) {
+		self.memory_set.insert(m.memory());
+	}
+}
+
+pub fn visit(ast: &FuncData) -> (BTreeSet<(&'static str, &'static str)>, BTreeSet<usize>) {
+	let mut visit = Visit {
+		local_set: BTreeSet::new(),
+		memory_set: BTreeSet::new(),
+	};
+
+	if ast
+		.local_data()
+		.iter()
+		.any(|v| v.value_type() == ValueType::I64)
+	{
+		visit.local_set.insert(("i64", "K_ZERO"));
+	}
+
+	ast.accept(&mut visit);
+
+	(visit.local_set, visit.memory_set)
+}

codegen/luau/src/analyzer/mod.rs

@@ -0,0 +1,3 @@
+pub mod as_symbol;
+pub mod br_table;
+pub mod localize;

codegen/luau/src/backend/expression.rs

@@ -0,0 +1,173 @@
+use std::{
+	io::{Result, Write},
+	num::FpCategory,
+};
+
+use wasm_ast::node::{
+	BinOp, CmpOp, Expression, GetGlobal, GetLocal, GetTemporary, LoadAt, MemorySize, Select, UnOp,
+	Value,
+};
+
+use crate::analyzer::as_symbol::AsSymbol;
+
+use super::manager::{
+	write_cmp_op, write_condition, write_separated, write_variable, Driver, Manager,
+};
+
+macro_rules! impl_write_number {
+	($name:tt, $numeric:ty) => {
+		fn $name(number: $numeric, w: &mut dyn Write) -> Result<()> {
+			match (number.classify(), number.is_sign_negative()) {
+				(FpCategory::Nan, true) => write!(w, "(0.0 / 0.0) "),
+				(FpCategory::Nan, false) => write!(w, "-(0.0 / 0.0) "),
+				(FpCategory::Infinite, true) => write!(w, "-math.huge "),
+				(FpCategory::Infinite, false) => write!(w, "math.huge "),
+				_ => write!(w, "{number:e} "),
+			}
+		}
+	};
+}
+
+impl Driver for Select {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "(")?;
+		write_condition(self.condition(), mng, w)?;
+		write!(w, "and ")?;
+		self.on_true().write(mng, w)?;
+		write!(w, "or ")?;
+		self.on_false().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for GetTemporary {
+	fn write(&self, _: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "reg_{} ", self.var())
+	}
+}
+
+impl Driver for GetLocal {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write_variable(self.var(), mng, w)
+	}
+}
+
+impl Driver for GetGlobal {
+	fn write(&self, _: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "GLOBAL_LIST[{}].value ", self.var())
+	}
+}
+
+impl Driver for LoadAt {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "load_{}(memory_at_0, ", self.load_type().as_name())?;
+		self.pointer().write(mng, w)?;
+
+		if self.offset() != 0 {
+			write!(w, "+ {}", self.offset())?;
+		}
+
+		write!(w, ")")
+	}
+}
+
+impl Driver for MemorySize {
+	fn write(&self, _: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "memory_at_{}.min ", self.memory())
+	}
+}
+
+pub fn write_i32(number: i32, w: &mut dyn Write) -> Result<()> {
+	let list = number.to_ne_bytes();
+
+	write!(w, "{} ", u32::from_ne_bytes(list))
+}
+
+fn write_i64(number: i64, w: &mut dyn Write) -> Result<()> {
+	match number {
+		0 => write!(w, "i64_K_ZERO "),
+		1 => write!(w, "i64_K_ONE "),
+		_ => {
+			let list = number.to_ne_bytes();
+			let a = u32::from_ne_bytes(list[0..4].try_into().unwrap());
+			let b = u32::from_ne_bytes(list[4..8].try_into().unwrap());
+
+			write!(w, "i64_from_u32({a}, {b}) ")
+		}
+	}
+}
+
+impl_write_number!(write_f32, f32);
+impl_write_number!(write_f64, f64);
+
+impl Driver for Value {
+	fn write(&self, _: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::I32(i) => write_i32(*i, w),
+			Self::I64(i) => write_i64(*i, w),
+			Self::F32(f) => write_f32(*f, w),
+			Self::F64(f) => write_f64(*f, w),
+		}
+	}
+}
+
+impl Driver for UnOp {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		let (a, b) = self.op_type().as_name();
+
+		write!(w, "{a}_{b}(")?;
+		self.rhs().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for BinOp {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		if let Some(symbol) = self.op_type().as_symbol() {
+			write!(w, "(")?;
+			self.lhs().write(mng, w)?;
+			write!(w, "{symbol} ")?;
+			self.rhs().write(mng, w)?;
+			write!(w, ")")
+		} else {
+			let (head, tail) = self.op_type().as_name();
+
+			write!(w, "{head}_{tail}(")?;
+			self.lhs().write(mng, w)?;
+			write!(w, ", ")?;
+			self.rhs().write(mng, w)?;
+			write!(w, ")")
+		}
+	}
+}
+
+impl Driver for CmpOp {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "(")?;
+		write_cmp_op(self, mng, w)?;
+		write!(w, "and 1 or 0)")
+	}
+}
+
+impl Driver for Expression {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::Select(e) => e.write(mng, w),
+			Self::GetTemporary(e) => e.write(mng, w),
+			Self::GetLocal(e) => e.write(mng, w),
+			Self::GetGlobal(e) => e.write(mng, w),
+			Self::LoadAt(e) => e.write(mng, w),
+			Self::MemorySize(e) => e.write(mng, w),
+			Self::Value(e) => e.write(mng, w),
+			Self::UnOp(e) => e.write(mng, w),
+			Self::BinOp(e) => e.write(mng, w),
+			Self::CmpOp(e) => e.write(mng, w),
+		}
+	}
+}
+
+impl Driver for &[Expression] {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write_separated(self.iter(), |e, w| e.write(mng, w), w)
+	}
+}

codegen/luau/src/backend/manager.rs

@@ -0,0 +1,109 @@
+use std::{
+	collections::HashMap,
+	io::{Result, Write},
+	ops::Range,
+};
+
+use wasm_ast::node::{BrTable, CmpOp, Expression};
+
+use crate::analyzer::as_symbol::AsSymbol;
+
+#[derive(PartialEq, Eq)]
+pub enum Label {
+	Forward,
+	Backward,
+}
+
+#[derive(Default)]
+pub struct Manager {
+	table_map: HashMap<usize, usize>,
+	label_list: Vec<Label>,
+	num_param: usize,
+}
+
+impl Manager {
+	pub fn get_table_index(&self, table: &BrTable) -> usize {
+		let id = table as *const _ as usize;
+
+		self.table_map[&id]
+	}
+
+	pub fn set_table_map(&mut self, map: HashMap<usize, usize>) {
+		self.table_map = map;
+	}
+
+	pub fn set_num_param(&mut self, num_param: usize) {
+		self.num_param = num_param;
+	}
+
+	pub fn label_list(&self) -> &[Label] {
+		&self.label_list
+	}
+
+	pub fn push_label(&mut self, label: Label) -> usize {
+		self.label_list.push(label);
+
+		self.label_list.len() - 1
+	}
+
+	pub fn pop_label(&mut self) {
+		self.label_list.pop().unwrap();
+	}
+}
+
+pub trait Driver {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()>;
+}
+
+pub fn write_separated<I, T, M>(mut iter: I, mut func: M, w: &mut dyn Write) -> Result<()>
+where
+	M: FnMut(T, &mut dyn Write) -> Result<()>,
+	I: Iterator<Item = T>,
+{
+	match iter.next() {
+		Some(first) => func(first, w)?,
+		None => return Ok(()),
+	}
+
+	iter.try_for_each(|v| {
+		write!(w, ", ")?;
+		func(v, w)
+	})
+}
+
+pub fn write_ascending(prefix: &str, range: Range<usize>, w: &mut dyn Write) -> Result<()> {
+	write_separated(range, |i, w| write!(w, "{prefix}_{i}"), w)
+}
+
+pub fn write_variable(var: usize, mng: &Manager, w: &mut dyn Write) -> Result<()> {
+	if let Some(rem) = var.checked_sub(mng.num_param) {
+		write!(w, "loc_{rem} ")
+	} else {
+		write!(w, "param_{var} ")
+	}
+}
+
+pub fn write_cmp_op(cmp: &CmpOp, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+	if let Some(symbol) = cmp.op_type().as_symbol() {
+		cmp.lhs().write(mng, w)?;
+		write!(w, "{symbol} ")?;
+		cmp.rhs().write(mng, w)
+	} else {
+		let (head, tail) = cmp.op_type().as_name();
+
+		write!(w, "{head}_{tail}(")?;
+		cmp.lhs().write(mng, w)?;
+		write!(w, ", ")?;
+		cmp.rhs().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+pub fn write_condition(data: &Expression, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+	if let Expression::CmpOp(node) = data {
+		write_cmp_op(node, mng, w)
+	} else {
+		data.write(mng, w)?;
+		write!(w, "~= 0 ")
+	}
+}

codegen/luau/src/backend/mod.rs

@@ -0,0 +1,4 @@
+pub mod manager;
+
+mod expression;
+mod statement;

codegen/luau/src/backend/statement.rs

@@ -0,0 +1,380 @@
+use std::{
+	io::{Result, Write},
+	ops::Range,
+};
+
+use parity_wasm::elements::ValueType;
+use wasm_ast::node::{
+	Backward, Br, BrIf, BrTable, Call, CallIndirect, Forward, FuncData, If, MemoryGrow, SetGlobal,
+	SetLocal, SetTemporary, Statement, StoreAt, Terminator,
+};
+
+use crate::analyzer::br_table;
+
+use super::manager::{
+	write_ascending, write_condition, write_separated, write_variable, Driver, Label, Manager,
+};
+
+impl Driver for Br {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		if !self.align().is_aligned() {
+			write_ascending("reg", self.align().new_range(), w)?;
+			write!(w, " = ")?;
+			write_ascending("reg", self.align().old_range(), w)?;
+			write!(w, " ")?;
+		}
+
+		if self.target() == 0 {
+			if let Some(&Label::Backward) = mng.label_list().last() {
+				write!(w, "continue ")?;
+			} else {
+				write!(w, "break ")?;
+			}
+		} else {
+			let level = mng.label_list().len() - 1 - self.target();
+
+			write!(w, "desired = {level} ")?;
+			write!(w, "break ")?;
+		}
+
+		Ok(())
+	}
+}
+
+fn to_ordered_table<'a>(list: &'a [Br], default: &'a Br) -> Vec<&'a Br> {
+	let mut data: Vec<_> = list.iter().chain(std::iter::once(default)).collect();
+
+	data.sort_by_key(|v| v.target());
+	data.dedup_by_key(|v| v.target());
+
+	data
+}
+
+fn write_search_layer(
+	range: Range<usize>,
+	list: &[&Br],
+	mng: &mut Manager,
+	w: &mut dyn Write,
+) -> Result<()> {
+	if range.len() == 1 {
+		return list[range.start].write(mng, w);
+	}
+
+	let center = range.start + range.len() / 2;
+	let br = list[center];
+
+	if range.start != center {
+		write!(w, "if temp < {} then ", br.target())?;
+		write_search_layer(range.start..center, list, mng, w)?;
+		write!(w, "else")?;
+	}
+
+	if range.end != center + 1 {
+		write!(w, "if temp > {} then ", br.target())?;
+		write_search_layer(center + 1..range.end, list, mng, w)?;
+		write!(w, "else")?;
+	}
+
+	write!(w, " ")?;
+	br.write(mng, w)?;
+	write!(w, "end ")
+}
+
+fn write_table_setup(table: &BrTable, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+	let id = mng.get_table_index(table);
+
+	write!(w, "if not br_map[{id}] then ")?;
+	write!(w, "br_map[{id}] = (function() return {{[0] =")?;
+
+	table
+		.data()
+		.iter()
+		.try_for_each(|v| write!(w, "{},", v.target()))?;
+
+	write!(w, "}} end)()")?;
+	write!(w, "end ")?;
+
+	write!(w, "local temp = br_map[{id}][")?;
+	table.condition().write(mng, w)?;
+	write!(w, "] or {} ", table.default().target())
+}
+
+impl Driver for BrTable {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		if self.data().is_empty() {
+			// Our condition should be pure so we probably don't need
+			// to emit it in this case.
+			return self.default().write(mng, w);
+		}
+
+		// `BrTable` is optimized by first mapping all indices to targets through
+		// a Lua table; this reduces the size of the code generated as duplicate entries
+		// don't need checking. Then, for speed, a binary search is done for the target
+		// and the appropriate jump is performed.
+		let list = to_ordered_table(self.data(), self.default());
+
+		write_table_setup(self, mng, w)?;
+		write_search_layer(0..list.len(), &list, mng, w)
+	}
+}
+
+impl Driver for Terminator {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::Unreachable => write!(w, "error(\"out of code bounds\")"),
+			Self::Br(s) => s.write(mng, w),
+			Self::BrTable(s) => s.write(mng, w),
+		}
+	}
+}
+
+fn br_target(level: usize, in_loop: bool, w: &mut dyn Write) -> Result<()> {
+	write!(w, "if desired then ")?;
+	write!(w, "if desired == {level} then ")?;
+	write!(w, "desired = nil ")?;
+
+	if in_loop {
+		write!(w, "continue ")?;
+	}
+
+	write!(w, "else ")?;
+	write!(w, "break ")?;
+	write!(w, "end ")?;
+	write!(w, "end ")
+}
+
+fn write_br_gadget(label_list: &[Label], rem: usize, w: &mut dyn Write) -> Result<()> {
+	match label_list.last() {
+		Some(Label::Forward) => br_target(rem, false, w),
+		Some(Label::Backward) => br_target(rem, true, w),
+		None => Ok(()),
+	}
+}
+
+impl Driver for Forward {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		let rem = mng.push_label(Label::Forward);
+
+		write!(w, "while true do ")?;
+
+		self.code().iter().try_for_each(|s| s.write(mng, w))?;
+
+		if let Some(v) = self.last() {
+			v.write(mng, w)?;
+		} else {
+			write!(w, "break ")?;
+		}
+
+		write!(w, "end ")?;
+
+		mng.pop_label();
+		write_br_gadget(mng.label_list(), rem, w)
+	}
+}
+
+impl Driver for Backward {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		let rem = mng.push_label(Label::Backward);
+
+		write!(w, "while true do ")?;
+
+		self.code().iter().try_for_each(|s| s.write(mng, w))?;
+
+		if let Some(v) = self.last() {
+			v.write(mng, w)?;
+		} else {
+			write!(w, "break ")?;
+		}
+
+		write!(w, "end ")?;
+
+		mng.pop_label();
+		write_br_gadget(mng.label_list(), rem, w)
+	}
+}
+
+impl Driver for BrIf {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "if ")?;
+		write_condition(self.condition(), mng, w)?;
+		write!(w, "then ")?;
+		self.target().write(mng, w)?;
+		write!(w, "end ")
+	}
+}
+
+impl Driver for If {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "if ")?;
+		write_condition(self.condition(), mng, w)?;
+		write!(w, "then ")?;
+
+		self.on_true().write(mng, w)?;
+
+		if let Some(v) = self.on_false() {
+			write!(w, "else ")?;
+
+			v.write(mng, w)?;
+		}
+
+		write!(w, "end ")
+	}
+}
+
+fn write_call_store(result: Range<usize>, w: &mut dyn Write) -> Result<()> {
+	if result.is_empty() {
+		return Ok(());
+	}
+
+	write_ascending("reg", result, w)?;
+	write!(w, " = ")
+}
+
+impl Driver for Call {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write_call_store(self.result(), w)?;
+
+		write!(w, "FUNC_LIST[{}](", self.function())?;
+		self.param_list().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for CallIndirect {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write_call_store(self.result(), w)?;
+
+		write!(w, "TABLE_LIST[{}].data[", self.table())?;
+		self.index().write(mng, w)?;
+		write!(w, "](")?;
+		self.param_list().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for SetTemporary {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "reg_{} = ", self.var())?;
+		self.value().write(mng, w)
+	}
+}
+
+impl Driver for SetLocal {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write_variable(self.var(), mng, w)?;
+		write!(w, "= ")?;
+		self.value().write(mng, w)
+	}
+}
+
+impl Driver for SetGlobal {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "GLOBAL_LIST[{}].value = ", self.var())?;
+		self.value().write(mng, w)
+	}
+}
+
+impl Driver for StoreAt {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		write!(w, "store_{}(memory_at_0, ", self.store_type().as_name())?;
+		self.pointer().write(mng, w)?;
+
+		if self.offset() != 0 {
+			write!(w, "+ {}", self.offset())?;
+		}
+
+		write!(w, ", ")?;
+		self.value().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for MemoryGrow {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		let result = self.result();
+		let memory = self.memory();
+
+		write!(w, "reg_{result} = rt.allocator.grow(memory_at_{memory}, ")?;
+		self.size().write(mng, w)?;
+		write!(w, ")")
+	}
+}
+
+impl Driver for Statement {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		match self {
+			Self::Forward(s) => s.write(mng, w),
+			Self::Backward(s) => s.write(mng, w),
+			Self::BrIf(s) => s.write(mng, w),
+			Self::If(s) => s.write(mng, w),
+			Self::Call(s) => s.write(mng, w),
+			Self::CallIndirect(s) => s.write(mng, w),
+			Self::SetTemporary(s) => s.write(mng, w),
+			Self::SetLocal(s) => s.write(mng, w),
+			Self::SetGlobal(s) => s.write(mng, w),
+			Self::StoreAt(s) => s.write(mng, w),
+			Self::MemoryGrow(s) => s.write(mng, w),
+		}
+	}
+}
+
+fn write_parameter_list(ast: &FuncData, w: &mut dyn Write) -> Result<()> {
+	write!(w, "function(")?;
+	write_ascending("param", 0..ast.num_param(), w)?;
+	write!(w, ")")
+}
+
+fn write_variable_list(ast: &FuncData, w: &mut dyn Write) -> Result<()> {
+	let mut total = 0;
+
+	for data in ast.local_data().iter().filter(|v| v.count() != 0) {
+		let range = total..total + usize::try_from(data.count()).unwrap();
+		let zero = if data.value_type() == ValueType::I64 {
+			"i64_K_ZERO "
+		} else {
+			"0 "
+		};
+
+		total = range.end;
+
+		write!(w, "local ")?;
+		write_ascending("loc", range.clone(), w)?;
+		write!(w, " = ")?;
+		write_separated(range, |_, w| w.write_all(zero.as_bytes()), w)?;
+		write!(w, " ")?;
+	}
+
+	if ast.num_stack() != 0 {
+		write!(w, "local ")?;
+		write_ascending("reg", 0..ast.num_stack(), w)?;
+		write!(w, " ")?;
+	}
+
+	Ok(())
+}
+
+impl Driver for FuncData {
+	fn write(&self, mng: &mut Manager, w: &mut dyn Write) -> Result<()> {
+		let br_map = br_table::visit(self);
+
+		write_parameter_list(self, w)?;
+		write_variable_list(self, w)?;
+		write!(w, "local desired ")?;
+
+		if !br_map.is_empty() {
+			write!(w, "local br_map = {{}} ")?;
+		}
+
+		mng.set_table_map(br_map);
+		mng.set_num_param(self.num_param());
+		self.code().write(mng, w)?;
+
+		if self.num_result() != 0 {
+			write!(w, "return ")?;
+			write_ascending("reg", 0..self.num_result(), w)?;
+			write!(w, " ")?;
+		}
+
+		write!(w, "end ")
+	}
+}

codegen/luau/src/bin/wasm2luau.rs

@@ -0,0 +1,38 @@
+use std::io::{Result, Write};
+
+use parity_wasm::{deserialize_file, elements::Module};
+
+fn load_module(name: &str) -> Module {
+	deserialize_file(name)
+		.expect("Failed to parse WebAssembly file")
+		.parse_names()
+		.unwrap_or_else(|v| v.1)
+}
+
+fn do_runtime(lock: &mut dyn Write) -> Result<()> {
+	let runtime = codegen_luau::RUNTIME;
+	let numeric = codegen_luau::NUMERIC;
+
+	writeln!(lock, "local rt = (function()")?;
+	writeln!(lock, "local I64 = (function()")?;
+	writeln!(lock, "{numeric}")?;
+	writeln!(lock, "end)()")?;
+	writeln!(lock, "{runtime}")?;
+	writeln!(lock, "end)()")
+}
+
+fn main() -> Result<()> {
+	let wasm = match std::env::args().nth(1) {
+		Some(name) => load_module(&name),
+		None => {
+			eprintln!("usage: wasm2luau <file>");
+
+			return Ok(());
+		}
+	};
+
+	let lock = &mut std::io::stdout().lock();
+
+	do_runtime(lock)?;
+	codegen_luau::from_module_untyped(&wasm, lock)
+}

codegen/luau/src/lib.rs

@@ -0,0 +1,8 @@
+pub static RUNTIME: &str = include_str!("../runtime/runtime.lua");
+pub static NUMERIC: &str = include_str!("../runtime/numeric.lua");
+
+pub use translator::{from_inst_list, from_module_typed, from_module_untyped};
+
+mod analyzer;
+mod backend;
+mod translator;

codegen/luau/src/translator.rs

@@ -0,0 +1,350 @@
+use std::{
+	collections::BTreeSet,
+	io::{Result, Write},
+};
+
+use parity_wasm::elements::{
+	External, ImportCountType, Instruction, Internal, Module, NameSection, ResizableLimits,
+};
+
+use wasm_ast::{
+	builder::{Builder, TypeInfo},
+	node::{FuncData, Statement},
+};
+
+use crate::{
+	analyzer::localize,
+	backend::manager::{Driver, Manager},
+};
+
+fn to_internal_index(internal: Internal) -> u32 {
+	match internal {
+		Internal::Function(v) | Internal::Table(v) | Internal::Memory(v) | Internal::Global(v) => v,
+	}
+}
+
+fn limit_data_of(limits: &ResizableLimits) -> (u32, u32) {
+	let max = limits.maximum().unwrap_or(0xFFFF);
+
+	(limits.initial(), max)
+}
+
+fn write_table_init(limit: &ResizableLimits, w: &mut dyn Write) -> Result<()> {
+	let (a, b) = limit_data_of(limit);
+
+	write!(w, "{{ min = {a}, max = {b}, data = {{}} }}")
+}
+
+fn write_memory_init(limit: &ResizableLimits, w: &mut dyn Write) -> Result<()> {
+	let (a, b) = limit_data_of(limit);
+
+	write!(w, "rt.allocator.new({a}, {b})")
+}
+
+fn write_named_array(name: &str, len: usize, w: &mut dyn Write) -> Result<()> {
+	let len = len.saturating_sub(1);
+
+	write!(w, "local {name} = table.create({len})")
+}
+
+fn write_constant(code: &[Instruction], type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	let func = Builder::from_type_info(type_info).build_anonymous(code);
+
+	if let Some(Statement::SetTemporary(stat)) = func.code().code().last() {
+		stat.value().write(&mut Manager::default(), w)?;
+	} else {
+		panic!("Not a valid constant");
+	}
+
+	Ok(())
+}
+
+fn write_import_of<T>(wasm: &Module, lower: &str, cond: T, w: &mut dyn Write) -> Result<()>
+where
+	T: Fn(&External) -> bool,
+{
+	let import = match wasm.import_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+	let upper = lower.to_uppercase();
+
+	for (i, v) in import.iter().filter(|v| cond(v.external())).enumerate() {
+		let field = v.field();
+		let module = v.module();
+
+		write!(w, r#"{upper}[{i}] = wasm["{module}"].{lower}["{field}"]"#)?;
+	}
+
+	Ok(())
+}
+
+fn write_export_of<T>(wasm: &Module, lower: &str, cond: T, w: &mut dyn Write) -> Result<()>
+where
+	T: Fn(&Internal) -> bool,
+{
+	let export = match wasm.export_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+	let upper = lower.to_uppercase();
+
+	write!(w, "{lower} = {{")?;
+
+	for v in export.iter().filter(|v| cond(v.internal())) {
+		let field = v.field();
+		let index = to_internal_index(*v.internal());
+
+		write!(w, r#"["{field}"] = {upper}[{index}],"#)?;
+	}
+
+	write!(w, "}},")
+}
+
+fn write_import_list(wasm: &Module, w: &mut dyn Write) -> Result<()> {
+	write_import_of(wasm, "func_list", |v| matches!(v, External::Function(_)), w)?;
+	write_import_of(wasm, "table_list", |v| matches!(v, External::Table(_)), w)?;
+	write_import_of(wasm, "memory_list", |v| matches!(v, External::Memory(_)), w)?;
+	write_import_of(wasm, "global_list", |v| matches!(v, External::Global(_)), w)
+}
+
+fn write_export_list(wasm: &Module, w: &mut dyn Write) -> Result<()> {
+	write_export_of(wasm, "func_list", |v| matches!(v, Internal::Function(_)), w)?;
+	write_export_of(wasm, "table_list", |v| matches!(v, Internal::Table(_)), w)?;
+	write_export_of(wasm, "memory_list", |v| matches!(v, Internal::Memory(_)), w)?;
+	write_export_of(wasm, "global_list", |v| matches!(v, Internal::Global(_)), w)
+}
+
+fn write_table_list(wasm: &Module, w: &mut dyn Write) -> Result<()> {
+	let table = match wasm.table_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+	let offset = wasm.import_count(ImportCountType::Table);
+
+	for (i, v) in table.iter().enumerate() {
+		write!(w, "TABLE_LIST[{}] =", i + offset)?;
+		write_table_init(v.limits(), w)?;
+	}
+
+	Ok(())
+}
+
+fn write_memory_list(wasm: &Module, w: &mut dyn Write) -> Result<()> {
+	let memory = match wasm.memory_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+	let offset = wasm.import_count(ImportCountType::Memory);
+
+	for (i, v) in memory.iter().enumerate() {
+		write!(w, "MEMORY_LIST[{}] =", i + offset)?;
+		write_memory_init(v.limits(), w)?;
+	}
+
+	Ok(())
+}
+
+fn write_global_list(wasm: &Module, type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	let global = match wasm.global_section() {
+		Some(v) => v,
+		None => return Ok(()),
+	};
+	let offset = wasm.import_count(ImportCountType::Global);
+
+	for (i, v) in global.entries().iter().enumerate() {
+		write!(w, "GLOBAL_LIST[{}] = {{ value =", i + offset)?;
+		write_constant(v.init_expr().code(), type_info, w)?;
+		write!(w, "}}")?;
+	}
+
+	Ok(())
+}
+
+fn write_element_list(wasm: &Module, type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	let element = match wasm.elements_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+
+	for v in element {
+		let code = v.offset().as_ref().unwrap().code();
+
+		write!(w, "do ")?;
+		write!(w, "local target = TABLE_LIST[{}].data ", v.index())?;
+		write!(w, "local offset =")?;
+
+		write_constant(code, type_info, w)?;
+
+		write!(w, "local data = {{")?;
+
+		v.members()
+			.iter()
+			.try_for_each(|v| write!(w, "FUNC_LIST[{v}],"))?;
+
+		write!(w, "}}")?;
+
+		write!(w, "table.move(data, 1, #data, offset, target)")?;
+
+		write!(w, "end ")?;
+	}
+
+	Ok(())
+}
+
+fn write_data_list(wasm: &Module, type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	let data = match wasm.data_section() {
+		Some(v) => v.entries(),
+		None => return Ok(()),
+	};
+
+	for v in data {
+		let code = v.offset().as_ref().unwrap().code();
+		let index = v.index();
+
+		write!(w, "rt.store.string(")?;
+		write!(w, "MEMORY_LIST[{index}],")?;
+		write_constant(code, type_info, w)?;
+		write!(w, r#","{}")"#, v.value().escape_ascii())?;
+	}
+
+	Ok(())
+}
+
+fn build_func_list(wasm: &Module, type_info: &TypeInfo) -> Vec<FuncData> {
+	let list = match wasm.code_section() {
+		Some(v) => v.bodies(),
+		None => return Vec::new(),
+	};
+
+	let mut builder = Builder::from_type_info(type_info);
+
+	list.iter()
+		.enumerate()
+		.map(|f| builder.build_indexed(f.0, f.1))
+		.collect()
+}
+
+fn write_local_operation(head: &str, tail: &str, w: &mut dyn Write) -> Result<()> {
+	match (head, tail) {
+		("band" | "bor" | "bxor", "i32") => {
+			write!(w, "local {head}_{tail} = bit32.{head} ")
+		}
+		("abs" | "ceil" | "floor" | "sqrt", _) => {
+			write!(w, "local {head}_{tail} = math.{head} ")
+		}
+		_ => write!(w, "local {head}_{tail} = rt.{head}.{tail} "),
+	}
+}
+
+fn write_localize_used(func_list: &[FuncData], w: &mut dyn Write) -> Result<BTreeSet<usize>> {
+	let mut loc_set = BTreeSet::new();
+	let mut mem_set = BTreeSet::new();
+
+	for (loc, mem) in func_list.iter().map(localize::visit) {
+		loc_set.extend(loc);
+		mem_set.extend(mem);
+	}
+
+	for loc in loc_set {
+		write_local_operation(loc.0, loc.1, w)?;
+	}
+
+	for mem in &mem_set {
+		write!(w, "local memory_at_{mem} ")?;
+	}
+
+	Ok(mem_set)
+}
+
+fn write_func_start(wasm: &Module, index: u32, w: &mut dyn Write) -> Result<()> {
+	let opt = wasm
+		.names_section()
+		.and_then(NameSection::functions)
+		.and_then(|v| v.names().get(index));
+
+	write!(w, "FUNC_LIST")?;
+
+	if let Some(name) = opt {
+		write!(w, "--[[ {name} ]]")?;
+	}
+
+	write!(w, "[{index}] =")
+}
+
+fn write_func_list(
+	wasm: &Module,
+	type_info: &TypeInfo,
+	func_list: &[FuncData],
+	w: &mut dyn Write,
+) -> Result<()> {
+	func_list.iter().enumerate().try_for_each(|(i, v)| {
+		let index = (type_info.len_ex() + i).try_into().unwrap();
+
+		write_func_start(wasm, index, w)?;
+
+		v.write(&mut Manager::default(), w)
+	})
+}
+
+fn write_module_start(
+	wasm: &Module,
+	type_info: &TypeInfo,
+	mem_set: &BTreeSet<usize>,
+	w: &mut dyn Write,
+) -> Result<()> {
+	write!(w, "local function run_init_code()")?;
+	write_table_list(wasm, w)?;
+	write_memory_list(wasm, w)?;
+	write_global_list(wasm, type_info, w)?;
+	write_element_list(wasm, type_info, w)?;
+	write_data_list(wasm, type_info, w)?;
+	write!(w, "end ")?;
+
+	write!(w, "return function(wasm)")?;
+	write_import_list(wasm, w)?;
+	write!(w, "run_init_code()")?;
+
+	for mem in mem_set {
+		write!(w, "memory_at_{mem} = MEMORY_LIST[{mem}]")?;
+	}
+
+	if let Some(start) = wasm.start_section() {
+		write!(w, "FUNC_LIST[{start}]()")?;
+	}
+
+	write!(w, "return {{")?;
+	write_export_list(wasm, w)?;
+	write!(w, "}} end ")
+}
+
+/// # Errors
+/// Returns `Err` if writing to `Write` failed.
+pub fn from_inst_list(code: &[Instruction], type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	Builder::from_type_info(type_info)
+		.build_anonymous(code)
+		.write(&mut Manager::default(), w)
+}
+
+/// # Errors
+/// Returns `Err` if writing to `Write` failed.
+pub fn from_module_typed(wasm: &Module, type_info: &TypeInfo, w: &mut dyn Write) -> Result<()> {
+	let func_list = build_func_list(wasm, type_info);
+	let mem_set = write_localize_used(&func_list, w)?;
+
+	write_named_array("FUNC_LIST", wasm.functions_space(), w)?;
+	write_named_array("TABLE_LIST", wasm.table_space(), w)?;
+	write_named_array("MEMORY_LIST", wasm.memory_space(), w)?;
+	write_named_array("GLOBAL_LIST", wasm.globals_space(), w)?;
+
+	write_func_list(wasm, type_info, &func_list, w)?;
+	write_module_start(wasm, type_info, &mem_set, w)
+}
+
+/// # Errors
+/// Returns `Err` if writing to `Write` failed.
+pub fn from_module_untyped(wasm: &Module, w: &mut dyn Write) -> Result<()> {
+	let type_info = TypeInfo::from_module(wasm);
+
+	from_module_typed(wasm, &type_info, w)
+}