♻️ refactor: match the Lua CLI API more closely

Cargo.lock

@@ -3,60 +3,12 @@
 version = 3
 
 [[package]]
-name = "arrayref"
-version = "0.3.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b4930d2cb77ce62f89ee5d5289b4ac049559b1c45539271f5ed4fdc7db34545"
-
-[[package]]
-name = "arrayvec"
-version = "0.7.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96d30a06541fbafbc7f82ed10c06164cfbd2c401138f6addd8404629c4b16711"
-
-[[package]]
-name = "blake3"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0231f06152bf547e9c2b5194f247cd97aacf6dcd8b15d8e5ec0663f64580da87"
+name = "lunar_wave_cli"
+version = "0.1.0"
 dependencies = [
- "arrayref",
- "arrayvec",
- "cc",
- "cfg-if",
- "constant_time_eq",
+ "lunar_wave_vm",
 ]
 
-[[package]]
-name = "cc"
-version = "1.0.83"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
-dependencies = [
- "libc",
-]
-
-[[package]]
-name = "cfg-if"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-
-[[package]]
-name = "constant_time_eq"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7144d30dcf0fafbce74250a3963025d8d52177934239851c917d29f1df280c2"
-
-[[package]]
-name = "libc"
-version = "0.2.148"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9cdc71e17332e86d2e1d38c1f99edcb6288ee11b815fb1a4b049eaa2114d369b"
-
 [[package]]
 name = "lunar_wave_vm"
 version = "0.1.0"
-dependencies = [
- "blake3",
-]

Cargo.toml

@@ -1,21 +1,6 @@
-[package]
-name = "lunar_wave_vm"
-description = "A Lua virtual machine implementation"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
-
-[dev-dependencies]
-
-# blake3, used to hash test vectors
-blake3 = "1.5.0"
-
-[target.x86_64-unknown-linux-gnu]
-linker = "/usr/bin/clang"
-# Recommended for flamegraph
-rustflags = ["-Clink-arg=-fuse-ld=lld", "-Clink-arg=-Wl,--no-rosegment"]
-
-[profile.release]
-# Recommended for profiling, e.g. flamegraph
-debug = true
+[workspace]
+resolver = "2"
+members = [
+	"lunar_wave_cli",
+	"lunar_wave_vm",
+]

lunar_wave_cli/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "lunar_wave_cli"
+description = "A Lua CLI implementation"
+version = "0.1.0"
+edition = "2021"
+authors = ["ReactorScram"]
+
+[dependencies]
+lunar_wave_vm = { path = "../lunar_wave_vm" }
+
+[target.x86_64-unknown-linux-gnu]
+linker = "/usr/bin/clang"
+# Recommended for flamegraph
+rustflags = ["-Clink-arg=-fuse-ld=lld", "-Clink-arg=-Wl,--no-rosegment"]
+
+[profile.release]
+# Recommended for profiling, e.g. flamegraph
+debug = true

lunar_wave_cli/src/main.rs

@@ -0,0 +1,124 @@
+// cargo run -- --script lunar_wave_vm/test_vectors/fizz_buzz.lua
+
+use std::io::Read;
+
+use lunar_wave_vm as lwvm;
+
+fn main () -> Result <(), lwvm::StepError> {
+	let args: Vec <_> = std::env::args ().collect ();
+	lunar_wave (args)?;
+	Ok (())
+}
+
+fn lunar_wave (args: Vec <String>) -> Result <Vec <lwvm::Value>, lwvm::StepError> {
+	let mut list_bytecode = false;
+	let mut breakpoints = vec![];
+	let mut chunk = None;
+	let mut lua_args = vec! [];
+	
+	let mut arg_iter = args.iter ();
+	let _exe_name = arg_iter.next ().unwrap ();
+	
+	while let Some (arg) = arg_iter.next () {
+		match arg.as_str () {
+			"--break" => {
+				let s = arg_iter.next ().unwrap ();
+				let (block_idx, program_counter) = s.split_once (":").unwrap ();
+				let block_idx = str::parse (block_idx).unwrap ();
+				let program_counter = str::parse (program_counter).unwrap ();
+				
+				breakpoints.push (lwvm::Breakpoint {
+					block_idx,
+					program_counter,
+				});
+			},
+			"--list-bytecode" => list_bytecode = true,
+			"-" => {
+				let mut buf = vec! [];
+				std::io::stdin ().read_to_end (&mut buf).unwrap ();
+				let bc = lwvm::ensure_bytecode (buf);
+				let mut rdr = std::io::Cursor::new (bc);
+				chunk = Some (lwvm::parse_chunk (&mut rdr).unwrap ());
+				
+				lua_args = vec! ["-".to_string ()];
+			},
+			"--" => break,
+			x => {
+				if x.starts_with ('-') {
+					panic! ("Unknown flag `{x}`");
+				}
+				else if chunk.is_none () {
+					let bc = lwvm::compile_bytecode_from_file (x);
+					let mut rdr = std::io::Cursor::new (bc);
+					chunk = Some (lwvm::parse_chunk (&mut rdr).unwrap ());
+					
+					lua_args = vec! [x.to_string ()];
+				}
+				else {
+					lua_args.push (x.into ());
+				}
+			},
+		}
+	}
+	
+	let chunk = chunk.unwrap ();
+	
+	if list_bytecode {
+		dbg! (&chunk);
+	}
+	
+	let upvalues = lwvm::State::upvalues_from_args (lua_args.into_iter ());
+	
+	let mut vm = lwvm::State::new (chunk, upvalues);
+	if std::env::var("LWVM_DEBUG").is_ok() {
+		vm.debug_print = true;
+	}
+	
+	let mut in_break = false;
+	let mut last_input = String::new ();
+	
+	loop {
+		if in_break || breakpoints.iter ().any (|bp| vm.at_breakpoint (bp)) {
+			in_break = true;
+			dbg! (&vm.stack);
+			
+			let mut input = Default::default ();
+			std::io::stdin ().read_line (&mut input).unwrap ();
+			
+			let input = if input == "" {
+				&last_input
+			}
+			else {
+				last_input = input;
+				&last_input
+			};
+			
+			match input.as_str ().trim_end () {
+				"c" => in_break = false,
+				"q" => return Ok (vec! []),
+				"registers" => {
+					dbg! (&vm.registers);
+					continue;
+				}
+				"s" => {
+					match vm.step ()? {
+						None => (),
+						Some (lwvm::StepOutput::ChunkReturned (x)) => {
+							return Ok (x);
+						},
+					}
+					continue;
+				},
+				x => { dbg! (x); },
+			}
+		}
+		
+		match vm.step ()? {
+			None => (),
+			Some (lwvm::StepOutput::ChunkReturned (x)) => {
+				return Ok (x);
+			},
+		}
+	}
+}
+

lunar_wave_vm/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "lunar_wave_vm"
+description = "A Lua virtual machine implementation"
+version = "0.1.0"
+edition = "2021"
+authors = ["ReactorScram"]

lunar_wave_vm/src/lib.rs

@@ -0,0 +1,17 @@
+mod instruction;
+mod loader;
+mod state;
+mod value;
+
+pub use loader::compile_bytecode_from_file as compile_bytecode_from_file;
+pub use loader::compile_bytecode as compile_bytecode;
+pub use loader::ensure_bytecode as ensure_bytecode;
+pub use loader::parse_chunk as parse_chunk;
+pub use state::Breakpoint as Breakpoint;
+pub use state::State as State;
+pub use state::StepError as StepError;
+pub use state::StepOutput as StepOutput;
+pub use value::Value as Value;
+
+#[cfg (test)]
+mod tests;

lunar_wave_vm/src/loader.rs

@@ -8,12 +8,10 @@ use crate::{
 	}
 };
 
-pub (crate) fn compile_bytecode_from_file (path: &str) -> Vec <u8> {
-	use std::{
-		process::{
+pub fn compile_bytecode_from_file (path: &str) -> Vec <u8> {
+	use std::process::{
 		Command,
 		Stdio,
-		},
 	};
 	
 	let child = Command::new ("luac5.4")
@@ -36,7 +34,7 @@ pub (crate) fn compile_bytecode_from_file (path: &str) -> Vec <u8> {
 /// 
 /// `source` is a Vec because we move it to a worker thread
 
-pub (crate) fn compile_bytecode_from_stdin (source: Vec <u8>) -> Vec <u8> {
+pub fn compile_bytecode (source: Vec <u8>) -> Vec <u8> {
 	use std::{
 		io::Write,
 		process::{
@@ -66,6 +64,19 @@ pub (crate) fn compile_bytecode_from_stdin (source: Vec <u8>) -> Vec <u8> {
 	output.stdout.as_slice ().to_vec ()
 }
 
+/// Checks whether the input is already bytecode, or is possibly
+/// Lua source code. If it's source code, compiles and returns bytecode.
+/// If it's bytecode, just returns the input.
+
+pub fn ensure_bytecode (buffer: Vec <u8>) -> Vec <u8> {
+	let bytecode_header = &[0x1b, 0x4c, 0x75, 0x61, 0x54, 0x00, 0x19, 0x93];
+	if buffer.starts_with (bytecode_header) {
+		return buffer;
+	}
+	
+	compile_bytecode (buffer)
+}
+
 fn i_sb (buf: [u8; 4]) -> Option <i8> {
 	let b = buf [2];
 	i8::try_from (i32::try_from (b).ok ()? - 127).ok ()

lunar_wave_vm/src/state.rs

@@ -1,5 +1,3 @@
-use std::rc::Rc;
-
 use crate::{
 	instruction::Instruction,
 	value::{
@@ -8,21 +6,21 @@ use crate::{
 	},
 };
 
-#[derive (Debug)]
+#[derive (Clone, Debug)]
 pub struct Upvalue {
 	pub in_stack: bool,
 	pub idx: u8,
 	pub kind: u8,
 }
 
-#[derive (Debug)]
+#[derive (Clone, Debug)]
 pub struct Block {
 	pub instructions: Vec <Instruction>,
 	pub constants: Vec <Value>,
 	pub upvalues: Vec <Upvalue>,
 }
 
-#[derive (Debug)]
+#[derive (Clone, Debug)]
 pub struct Chunk {
 	pub blocks: Vec <Block>,
 }
@@ -47,7 +45,7 @@ pub struct Breakpoint {
 }
 
 #[derive (Debug)]
-pub struct State <'a> {
+pub struct State {
 	pub registers: Vec <Value>,
 	// Currently only used for native function calls
 	top: usize,
@@ -55,8 +53,8 @@ pub struct State <'a> {
 	
 	pub debug_print: bool,
 	step_count: u32,
-	chunk: &'a Chunk,
-	upvalues: &'a [Value],
+	chunk: Chunk,
+	upvalues: Vec <Value>,
 }
 
 fn lw_io_write (l: &mut State, num_args: usize) -> usize {
@@ -142,8 +140,8 @@ pub struct StepError {
 	msg: &'static str,
 }
 
-impl <'a> State <'a> {
-	pub fn new (chunk: &'a Chunk, upvalues: &'a [Value]) -> Self {
+impl State {
+	pub fn new (chunk: Chunk, upvalues: Vec <Value>) -> Self {
 		Self {
 			// TODO: Stack is actually supposed to grow to a limit of
 			// idk 10,000. I thought it was fixed at 256.
@@ -206,12 +204,12 @@ impl <'a> State <'a> {
 	
 	/// Short form to get access to a register within our window
 	
-	fn reg (&self, i: u8) -> &Value {
+	pub fn reg (&self, i: u8) -> &Value {
 		let frame = self.stack.last ().unwrap ();
 		&self.registers [frame.register_offset + i as usize]
 	}
 	
-	fn reg_mut (&mut self, i: u8) -> &mut Value {
+	pub fn reg_mut (&mut self, i: u8) -> &mut Value {
 		let frame = self.stack.last ().unwrap ();
 		&mut self.registers [frame.register_offset + i as usize]
 	}
@@ -232,11 +230,10 @@ impl <'a> State <'a> {
 	
 	pub fn step (&mut self) -> Result <Option <StepOutput>, StepError> 
 	{
-		let chunk = self.chunk;
 		self.step_count += 1;
 		
 		let frame = self.stack.last_mut ().unwrap ().clone ();
-		let block = chunk.blocks.get (frame.block_idx).unwrap ();
+		let block = self.chunk.blocks.get (frame.block_idx).unwrap ();
 		
 		let mut next_pc = frame.program_counter;
 		
@@ -256,10 +253,10 @@ impl <'a> State <'a> {
 			self.make_step_error (msg, instruction)
 		};
 		
-		match instruction {
+		match instruction.clone () {
 			Instruction::Add (a, b, c) => {
-				let v_b = self.reg (*b);
-				let v_c = self.reg (*c);
+				let v_b = self.reg (b);
+				let v_c = self.reg (c);
 				
 				let x = if let (Some (v_b), Some (v_c)) = (v_b.as_int (), v_c.as_int ()) 
 				{
@@ -271,24 +268,24 @@ impl <'a> State <'a> {
 					Value::from (v_b + v_c)
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
 			Instruction::AddI (a, b, s_c) => {
-				let v_b = self.reg (*b);
+				let v_b = self.reg (b);
 				
 				let x = if let Some (v_b) = v_b.as_int () 
 				{
-					Value::from (v_b + *s_c as i64)
+					Value::from (v_b + s_c as i64)
 				}
 				else {
 					let v_b = v_b.as_float ().unwrap_or_else (|| panic! ("{v_b}"));
-					Value::from (v_b + f64::from (*s_c))
+					Value::from (v_b + f64::from (s_c))
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
 			Instruction::Call (a, b, c) => {
-				let b = usize::from (*b);
+				let b = usize::from (b);
 				
 				// Take arguments from registers [a + 1, a + b)
 				// Call the function in register [a]
@@ -301,7 +298,7 @@ impl <'a> State <'a> {
 				// Do a clone here to avoid a borow problem.
 				// Should be fixable with more clever code.
 				
-				let v_a = self.reg (*a).clone ();
+				let v_a = self.reg (a).clone ();
 				
 				match v_a {
 					Value::BogusClosure (rc) => {
@@ -315,7 +312,7 @@ impl <'a> State <'a> {
 						self.stack.push (StackFrame {
 							program_counter: 0,
 							block_idx: target_block,
-							register_offset: current_frame.register_offset + *a as usize + 1,
+							register_offset: current_frame.register_offset + a as usize + 1,
 						});
 						
 						if self.debug_print {
@@ -329,23 +326,25 @@ impl <'a> State <'a> {
 					},
 					Value::RsFunc (x) => {
 						let current_frame = self.stack.last ().unwrap ();
-						let new_offset = current_frame.register_offset + usize::from (*a) + 1;
+						let new_offset = current_frame.register_offset + usize::from (a) + 1;
+						
+						// Trash the stack frame so it doesn't point to a
+						// valid Lua function
 						self.stack.push (StackFrame {
 							program_counter: 65535, // Bogus for native functions
 							block_idx: 65535, // Bogus
 							register_offset: new_offset,
 						});
 						
-						// No clue what the '1' is doing here
-						let b = if b == 0 {
-							self.top - *a as usize
+						let num_args = if b == 0 {
+							self.top - a as usize
 						}
 						else {
-							b
+							b - 1
 						};
 						
 						// Call
-						let num_results = x (self, b - 1);
+						let num_results = x (self, num_args);
 						
 						let popped_frame = self.stack.pop ().unwrap ();
 						let offset = popped_frame.register_offset - 1;
@@ -355,7 +354,7 @@ impl <'a> State <'a> {
 						}
 						
 						// Set up top for the next call
-						if *c == 0 {
+						if c == 0 {
 							self.top = popped_frame.register_offset - 1 + num_results;
 						}
 					},
@@ -365,10 +364,10 @@ impl <'a> State <'a> {
 				}
 			},
 			Instruction::Closure (a, b) => {
-				let b = usize::try_from (*b).unwrap ();
+				let b = usize::try_from (b).unwrap ();
 				
 				let idx = frame.block_idx + b + 1;
-				let block = &chunk.blocks [idx];
+				let block = &self.chunk.blocks [idx];
 				
 				let mut new_upvalues = Vec::with_capacity (block.upvalues.len ());
 				for uv in &block.upvalues {
@@ -382,31 +381,31 @@ impl <'a> State <'a> {
 					new_upvalues.push (val);
 				}
 				
-				*self.reg_mut (*a) = Value::from (BogusClosure {
+				*self.reg_mut (a) = Value::from (BogusClosure {
 					idx,
 					upvalues: new_upvalues,
 				});
 			},
 			Instruction::Div (a, b, c) => {
-				let v_b = self.reg (*b);
-				let v_c = self.reg (*c);
+				let v_b = self.reg (b);
+				let v_c = self.reg (c);
 				
 				let v_b = v_b.as_float ().unwrap_or_else (|| panic! ("{v_b}"));
 				
 				let v_c = v_c.as_float ().ok_or_else (|| make_step_error ("C must be a number"))?;
 				
-				*self.reg_mut (*a) = Value::from (v_b / v_c);
+				*self.reg_mut (a) = Value::from (v_b / v_c);
 			},
 			Instruction::EqI (a, sb, k_flag) => {
-				if (self.reg (*a).as_int ().unwrap () == *sb as i64) != *k_flag 
+				if (self.reg (a).as_int ().unwrap () == sb as i64) != k_flag 
 				{
 					next_pc += 1;
 				}
 			},
 			Instruction::EqK (a, b, k_flag) => {
-				let b = usize::from (*b);
+				let b = usize::from (b);
 				
-				if (*self.reg (*a) == k [b]) != *k_flag {
+				if (*self.reg (a) == k [b]) != k_flag {
 					next_pc += 1;
 				}
 			},
@@ -414,60 +413,60 @@ impl <'a> State <'a> {
 				// This is used for NewTable. Maybe it's for reserving
 				// capacity in the array or something?
 				
-				assert_eq! (*ax, 0, "implemented only for ax == 0");
+				assert_eq! (ax, 0, "implemented only for ax == 0");
 			},
 			Instruction::ForLoop (a, bx) => {
-				let mut iter = self.reg (*a + 3).as_int ().unwrap ();
+				let mut iter = self.reg (a + 3).as_int ().unwrap ();
 				iter += 1;
-				*self.reg_mut (*a + 3) = iter.into ();
+				*self.reg_mut (a + 3) = iter.into ();
 				
-				let stop = self.reg (*a + 1).as_int ().unwrap ();
+				let stop = self.reg (a + 1).as_int ().unwrap ();
 				
 				if iter <= stop {
-					next_pc -= i32::try_from (*bx).unwrap ();
+					next_pc -= i32::try_from (bx).unwrap ();
 				}
 			},
 			Instruction::ForPrep (a, bx) => {
-				let start = self.reg (*a).as_int ().unwrap ();
-				let stop = self.reg (*a + 1).as_int ().unwrap ();
+				let start = self.reg (a).as_int ().unwrap ();
+				let stop = self.reg (a + 1).as_int ().unwrap ();
 				
 				if start > stop {
-					next_pc += i32::try_from (*bx).unwrap () + 1;
+					next_pc += i32::try_from (bx).unwrap () + 1;
 				}
 				
-				*self.reg_mut (*a + 3) = start.into ();
+				*self.reg_mut (a + 3) = start.into ();
 			},
 			Instruction::GetField (a, b, c) => {
-				let t = match self.reg (*b) {
+				let t = match self.reg (b) {
 					Value::Nil => Err (make_step_error ("R[B] must not be nil"))?,
 					Value::Table (t) => t,
 					_ => Err (make_step_error ("R[B] must be a table"))?,
 				};
 				
-				let key = match &k [usize::from (*c)] {
+				let key = match &k [usize::from (c)] {
 					Value::String (s) => s,
 					_ => panic! ("K[C] must be a string"),
 				};
 				
 				let val = t.borrow ().get_str (key.as_str ()).clone ();
 				
-				*self.reg_mut (*a) = val;
+				*self.reg_mut (a) = val;
 			},
 			Instruction::GetTable (a, b, c) => {
-				let t = match self.reg (*b) {
+				let t = match self.reg (b) {
 					Value::Table (t) => t,
 					_ => panic! ("R[B] must be a table"),
 				};
 				
-				let key = self.reg (*c);
+				let key = self.reg (c);
 				
 				let val = t.borrow ().get (key.clone ());
 				
-				*self.reg_mut (*a) = val;
+				*self.reg_mut (a) = val;
 			},
 			Instruction::GetTabUp (a, b, c) => {
-				let b = usize::try_from (*b).unwrap ();
-				let c = usize::try_from (*c).unwrap ();
+				let b = usize::try_from (b).unwrap ();
+				let c = usize::try_from (c).unwrap ();
 				
 				// If we're inside a closure, use its upvalues
 				// instead of the chunk's upvalues
@@ -493,17 +492,17 @@ impl <'a> State <'a> {
 					_ => panic! ("GetTabUp only supports string keys"),
 				};
 				
-				*self.reg_mut (*a) = table.get (key);
+				*self.reg_mut (a) = table.get (key);
 			},
 			Instruction::GetI (a, b, c) => {
-				let key = i64::try_from (*c).unwrap ();
+				let key = i64::try_from (c).unwrap ();
 				
 				let value = {
-					let table = self.reg (*b).as_table ().expect ("GetI only works on tables").borrow ();
+					let table = self.reg (b).as_table ().expect ("GetI only works on tables").borrow ();
 					table.get_int (key)
 				};
 				
-				*self.reg_mut (*a) = value;
+				*self.reg_mut (a) = value;
 			},
 			Instruction::GetUpVal (a, b) => {
 				let this_func = self.stack.last ().unwrap ().register_offset - 1;
@@ -512,20 +511,20 @@ impl <'a> State <'a> {
 					_ => panic! ("Can't do GetUpVal outside a closure"),
 				};
 				
-				let b  = usize::try_from  (*b).unwrap ();
+				let b  = usize::try_from  (b).unwrap ();
 				
 				let upvalue = match closure.borrow ().upvalues.get (b) {
 					Some (x) => x.clone (),
 					None => {
-						dbg! (chunk, &self);
+						dbg! (&self);
 						panic! ("Missing upvalue");
 					}
 				};
-				*self.reg_mut (*a) = upvalue;
+				*self.reg_mut (a) = upvalue;
 			},
 			Instruction::Jmp (s_j) => next_pc += s_j,
 			Instruction::Len (a, b) => {
-				let len = match self.reg (*b) {
+				let len = match self.reg (b) {
 					Value::BogusClosure (_) => Err (make_step_error ("attempt to get length of a function value"))?,
 					Value::Boolean (_) => Err (make_step_error ("attempt to get length of a boolean value"))?,
 					Value::Float (_) => Err (make_step_error ("attempt to get length of a number value"))?,
@@ -536,31 +535,31 @@ impl <'a> State <'a> {
 					Value::Table (t) => t.borrow ().length ().into (),
 				};
 				
-				*self.reg_mut (*a) = len;
+				*self.reg_mut (a) = len;
 			}
 			Instruction::LoadF (a, sbx) => {
-				*self.reg_mut (*a) = Value::Float (*sbx as f64);
+				*self.reg_mut (a) = Value::Float (sbx as f64);
 			}
 			Instruction::LoadFalse (a) => {
-				*self.reg_mut (*a) = false.into ();
+				*self.reg_mut (a) = false.into ();
 			},
 			Instruction::LoadI (a, sbx) => {
-				*self.reg_mut (*a) = Value::Integer (*sbx as i64);
+				*self.reg_mut (a) = Value::Integer (sbx as i64);
 			},
 			Instruction::LoadK (a, bx) => {
-				let bx = usize::try_from (*bx).unwrap ();
+				let bx = usize::try_from (bx).unwrap ();
 				
-				*self.reg_mut (*a) = k [bx].clone ();
+				*self.reg_mut (a) = k [bx].clone ();
 			},
 			Instruction::LoadNil (a) => {
-				*self.reg_mut (*a) = Value::Nil;
+				*self.reg_mut (a) = Value::Nil;
 			},
 			Instruction::LoadTrue (a) => {
-				*self.reg_mut (*a) = true.into ();
+				*self.reg_mut (a) = true.into ();
 			},
 			Instruction::MmBin (a, b, _c) => {
-				let a = self.reg (*a);
-				let b = self.reg (*b);
+				let a = self.reg (a);
+				let b = self.reg (b);
 				
 				if a.as_float().is_some() && b.as_float().is_some () {
 					// No need for metamethods
@@ -576,20 +575,20 @@ impl <'a> State <'a> {
 				// Ignore
 			},
 			Instruction::ModK (a, b, c) => {
-				let b = self.reg (*b).as_int().unwrap ();
-				let c = k [usize::from (*c)].as_int ().unwrap ();
+				let b = self.reg (b).as_int().unwrap ();
+				let c = k [usize::from (c)].as_int ().unwrap ();
 				
-				*self.reg_mut (*a) = (b % c).into ();
+				*self.reg_mut (a) = (b % c).into ();
 			},
 			Instruction::Move (a, b) => {
 				// If the value in b is deleted instead of duplicated,
 				// a bunch of tests fail
 				
-				*self.reg_mut (*a) = self.reg (*b).clone ();
+				*self.reg_mut (a) = self.reg (b).clone ();
 			},
 			Instruction::Mul (a, b, c) => {
-				let v_b = self.reg (*b);
-				let v_c = self.reg (*c);
+				let v_b = self.reg (b);
+				let v_c = self.reg (c);
 				
 				let x = if let (Some (v_b), Some (v_c)) = (v_b.as_int (), v_c.as_int ()) 
 				{
@@ -601,11 +600,11 @@ impl <'a> State <'a> {
 					Value::from (v_b * v_c)
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
 			Instruction::MulK (a, b, c) => {
-				let v_b = self.reg (*b);
-				let v_c = &k [usize::from (*c)];
+				let v_b = self.reg (b);
+				let v_c = &k [usize::from (c)];
 				
 				let x = if let (Some (v_b), Some (v_c)) = (v_b.as_int (), v_c.as_int ()) 
 				{
@@ -617,30 +616,30 @@ impl <'a> State <'a> {
 					Value::from (v_b * v_c)
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
 			Instruction::NewTable (a) => {
-				*self.reg_mut (*a) = Value::Table (Default::default ());
+				*self.reg_mut (a) = Value::Table (Default::default ());
 			},
 			Instruction::Not (a, b) => {
-				*self.reg_mut (*a) = Value::Boolean (! self.reg (*b).is_truthy());
+				*self.reg_mut (a) = Value::Boolean (! self.reg (b).is_truthy());
 			}
-			Instruction::Return (a, b, _c, k) => {
-				let a = usize::try_from (*a).unwrap ();
-				let b = usize::try_from (*b).unwrap ();
+			Instruction::Return (a, b, _c, k_flag) => {
+				let a = usize::try_from (a).unwrap ();
+				let b = usize::try_from (b).unwrap ();
 				
 				let popped_frame = self.stack.pop ().unwrap ();
 				
 				// Build closure if needed. No point building if we're
 				// popping the last frame and exiting the program.
 				
-				if *k && ! self.stack.is_empty () {
+				if k_flag && ! self.stack.is_empty () {
 					let closure_idx = match &self.registers [popped_frame.register_offset + a] {
 						Value::BogusClosure (rc) => rc.borrow ().idx,
 						_ => panic! ("Impossible"),
 					};
 					
-					let upvalue_count = chunk.blocks [closure_idx].upvalues.len ();
+					let upvalue_count = self.chunk.blocks [closure_idx].upvalues.len ();
 					
 					let start_reg = a + popped_frame.register_offset - upvalue_count;
 					
@@ -678,7 +677,7 @@ impl <'a> State <'a> {
 					self.top = popped_frame.register_offset - 1 + b - 1;
 				}
 				else {
-					// Return from the entire program
+					// Return from the entire chunk
 					return Ok (Some (StepOutput::ChunkReturned (self.registers [a..(a + b - 1)].to_vec())));
 				}
 			},
@@ -688,7 +687,7 @@ impl <'a> State <'a> {
 				self.top = popped_frame.register_offset - 1 + 0;
 			},
 			Instruction::Return1 (a) => {
-				let a = usize::try_from (*a).unwrap ();
+				let a = usize::try_from (a).unwrap ();
 				let popped_frame = self.stack.pop ().unwrap ();
 				
 				
@@ -713,58 +712,58 @@ impl <'a> State <'a> {
 				self.top = popped_frame.register_offset - 1 + 1;
 			},
 			Instruction::SetField (a, b, c, k_flag) => {
-				let value = if *k_flag {
-					&k [usize::from (*c)]
+				let value = if k_flag {
+					&k [usize::from (c)]
 				}
 				else {
-					self.reg (*c)
+					self.reg (c)
 				}
 				.clone ();
 				
-				let b = usize::try_from (*b).unwrap ();
+				let b = usize::try_from (b).unwrap ();
 				
 				let key = match k.get (b).unwrap () {
 					Value::String (s) => s.as_ref (),
 					_ => panic! ("SetField only supports string keys"),
 				};
 				
-				let mut dst = self.reg (*a).as_table ()
+				let mut dst = self.reg (a).as_table ()
 				.expect ("SetField only works on tables").borrow_mut ();
 				
 				dst.insert_str (key.as_str (), value);
 			},
 			Instruction::SetI (a, b, c, k_flag) => {
-				let value = if *k_flag {
-					&k [usize::from (*c)]
+				let value = if k_flag {
+					&k [usize::from (c)]
 				}
 				else {
-					self.reg (*c)
+					self.reg (c)
 				}
 				.clone ();
 				
-				let mut dst = self.reg_mut (*a).as_table ().expect ("SetI only works on tables").borrow_mut ();
+				let mut dst = self.reg_mut (a).as_table ().expect ("SetI only works on tables").borrow_mut ();
 				
-				dst.insert_int (i64::from (*b), value);
+				dst.insert_int (i64::from (b), value);
 			},
-			Instruction::SetList (a, b, c, k) => {
-				if *b == 0 {
+			Instruction::SetList (a, b, c, k_flag) => {
+				if b == 0 {
 					panic! ("SetList with b == 0 not implemented");
 				}
-				if *k {
+				if k_flag {
 					panic! ("SetList with k = true not implemented");
 				}
 				
-				let mut dst = self.reg (*a).as_table ().expect ("SetList only works on tables").borrow_mut ();
+				let mut dst = self.reg (a).as_table ().expect ("SetList only works on tables").borrow_mut ();
 				
-				for i in 1..=*b {
-					let src = self.reg (*a + i);
-					dst.insert_int (i64::from (*c + i), src.clone ());
+				for i in 1..=b {
+					let src = self.reg (a + i);
+					dst.insert_int (i64::from (c + i), src.clone ());
 				}
 			},
 			Instruction::SetTabUp (_a, _b, _c) => unimplemented! (),
 			Instruction::Sub (a, b, c) => {
-				let v_b = self.reg (*b);
-				let v_c = self.reg (*c);
+				let v_b = self.reg (b);
+				let v_c = self.reg (c);
 				
 				let x = if let (Some (v_b), Some (v_c)) = (v_b.as_int (), v_c.as_int ()) 
 				{
@@ -776,28 +775,32 @@ impl <'a> State <'a> {
 					Value::from (v_b - v_c)
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
-			Instruction::TailCall (a, b, _c, k) => {
+			Instruction::TailCall (a, b, c, k) => {
+				let a = usize::from (a);
 				assert! (!k, "closing over values in tail calls not implemented");
 				
-				// Shift closure and inputs into place
-				let a = usize::from (*a);
-				let b = usize::from (*b);
-				let offset = frame.register_offset - 1;
-				for i in (offset)..(offset + b) {
-					self.registers [i] = self.registers [i + a + 1].take ();
-				}
+				let offset = frame.register_offset;
+				let value = self.registers [offset + a].take ();
+				match value {
+					Value::BogusClosure (closure) => {
+						let closure = closure.borrow ();
 						
-				let value = &self.registers [offset];
-				let closure = if let Some (x) = value.as_closure () {
-					x
+						// Shift inputs into place
+						
+						let b = usize::from (b);
+						
+						let num_args = if b == 0 {
+							self.top - a
 						}
 						else {
-					dbg! (self);
-					panic! ("OP_TAILCALL only implemented for closures");
+							b - 1
 						};
-				let closure = closure.borrow ();
+						
+						for i in (offset)..(offset + num_args) {
+							self.registers [i] = self.registers [i + a + 1].take ();
+						}
 						
 						// Jump into the other function
 						
@@ -808,13 +811,57 @@ impl <'a> State <'a> {
 						// Skip the PC increment
 						return Ok (None);
 					},
-			Instruction::Test (a, k) => {
-				if self.reg (*a).is_truthy() != *k {
+					Value::RsFunc (x) => {
+						// Shift inputs into place
+						let b = usize::from (b);
+						for i in (offset)..(offset + b) {
+							self.registers [i] = self.registers [i + a + 1].take ();
+						}
+						
+						let frame = self.stack.last_mut ().unwrap ();
+						// Trash the stack frame so it doesn't point
+						// to any valid Lua function
+						*frame = StackFrame {
+							block_idx: 65535,
+							program_counter: 65535,
+							register_offset: offset,
+						};
+						
+						let num_args = if b == 0 {
+							self.top - a
+						}
+						else {
+							b - 1
+						};
+						
+						// Call
+						let num_results = x (self, num_args);
+						let popped_frame = self.stack.pop ().unwrap ();
+						
+						if self.stack.is_empty () {
+							// The whole chunk is exiting
+							return Ok (Some (StepOutput::ChunkReturned (self.registers [a..(a + num_results)].to_vec())));
+						}
+						else {
+							// Set up top for the next call
+							if c == 0 {
+								self.top = popped_frame.register_offset - 1 + num_results;
+							}
+						}
+					},
+					_ => {
+						dbg! (&self.stack);
+						panic! ("OP_TAILCALL argument must be a function");
+					},
+				}
+			},
+			Instruction::Test (a, k_flag) => {
+				if self.reg (a).is_truthy() != k_flag {
 					next_pc += 1;
 				}
 			},
 			Instruction::UnM (a, b) => {
-				let v_b = self.reg (*b);
+				let v_b = self.reg (b);
 				
 				let x = if let Some (v_b) = v_b.as_int () 
 				{
@@ -825,7 +872,7 @@ impl <'a> State <'a> {
 					Value::from (-v_b)
 				};
 				
-				*self.reg_mut (*a) = x;
+				*self.reg_mut (a) = x;
 			},
 			Instruction::VarArgPrep (_) => (),
 		}

lunar_wave_vm/src/tests.rs

@@ -22,9 +22,9 @@ fn calculate_hash<T: Hash>(t: &T) -> u64 {
 /// Takes arguments and a parsed Lua chunk, runs its,
 /// and returns the output
 
-fn run_chunk (args: &[&str], chunk: &Chunk) -> Vec <Value> {
+fn run_chunk (args: &[&str], chunk: Chunk) -> Vec <Value> {
 	let upvalues = State::upvalues_from_args (args.into_iter ().map (|s| s.to_string ()));
-	let mut vm = State::new (chunk, &upvalues);
+	let mut vm = State::new (chunk, upvalues);
 	vm.execute_chunk (&[]).unwrap ()
 }
 
@@ -33,7 +33,7 @@ fn run_chunk (args: &[&str], chunk: &Chunk) -> Vec <Value> {
 
 fn run_bytecode (args: &[&str], bc: &[u8]) -> Vec <Value> {
 	let chunk = loader::parse_chunk_from_bytes (&bc).unwrap ();
-	run_chunk (args, &chunk)
+	run_chunk (args, chunk)
 }
 
 /// Takes arguments and Lua source code, 
@@ -42,7 +42,7 @@ fn run_bytecode (args: &[&str], bc: &[u8]) -> Vec <Value> {
 /// and returns the output
 
 fn run_source (args: &[&str], s: &str) -> Vec <Value> {
-	let bc = loader::compile_bytecode_from_stdin (s.as_bytes ().to_vec ());
+	let bc = loader::compile_bytecode (s.as_bytes ().to_vec ());
 	run_bytecode (args, &bc)
 }
 
@@ -119,7 +119,7 @@ fn bools () {
 		let expected: Vec <Value> = expected;
 		
 		let upvalues = State::upvalues_from_args (arg.into_iter ().map (|s| s.to_string ()));
-		let mut vm = State::new (&chunk, &upvalues);
+		let mut vm = State::new (chunk.clone (), upvalues);
 		let actual = vm.execute_chunk (&[]).unwrap ();
 		assert_eq! (actual, expected);
 	}
@@ -128,10 +128,10 @@ fn bools () {
 #[test]
 fn closure () {
 	let source = include_bytes! ("../test_vectors/closure.lua");
-	let bytecode = &crate::loader::compile_bytecode_from_stdin (source.to_vec ());
+	let bytecode = &crate::loader::compile_bytecode (source.to_vec ());
 	let chunk = crate::loader::parse_chunk_from_bytes (bytecode).unwrap ();
 	
-	assert_eq! (run_chunk (&["_exe_name"], &chunk), vec! [Value::from (23i64)]);
+	assert_eq! (run_chunk (&["_exe_name"], chunk), vec! [Value::from (23i64)]);
 }
 
 #[test]
@@ -175,7 +175,7 @@ fn floats () {
 	] {
 		let expected: Vec <Value> = expected;
 		let upvalues = State::upvalues_from_args (arg.into_iter ().map (|s| s.to_string ()));
-		let mut vm = State::new (&chunk, &upvalues);
+		let mut vm = State::new (chunk.clone (), upvalues);
 		let actual = vm.execute_chunk (&[]).unwrap ();
 		
 		assert_eq! (actual, expected);
@@ -185,24 +185,20 @@ fn floats () {
 #[test]
 fn fma () {
 	let source = include_bytes! ("../test_vectors/fma.lua");
-	let bytecode = &crate::loader::compile_bytecode_from_stdin (source.to_vec ());
+	let bytecode = &crate::loader::compile_bytecode (source.to_vec ());
 	let chunk = crate::loader::parse_chunk_from_bytes (bytecode).unwrap ();
 	assert_eq! (chunk.blocks.len (), 5);
 	
 	assert_eq! (chunk.blocks [3].upvalues.len (), 2);
 	
-	for (arg, expected) in [
-		(vec! ["_exe_name"], vec! [122.into ()]),
-		(vec! ["_exe_name"], vec! [122.into ()]),
-	] {
-		let expected: Vec <Value> = expected;
+	let arg = vec! ["_exe_name"];
 	let upvalues = State::upvalues_from_args (arg.into_iter ().map (|s| s.to_string ()));
-		let mut vm = State::new (&chunk, &upvalues);
+	let mut vm = State::new (chunk, upvalues);
 	let actual = vm.execute_chunk (&[]).unwrap ();
+	let expected = vec! [Value::from (122)];
 	
 	assert_eq! (actual, expected);
 }
-}
 
 #[test]
 fn heap () {
@@ -279,29 +275,29 @@ fn is_93 () {
 	end
 	"#;
 	
-	let bc = loader::compile_bytecode_from_stdin (src.as_bytes ().to_vec ());
+	let bc = loader::compile_bytecode (src.as_bytes ().to_vec ());
 	let chunk = loader::parse_chunk_from_bytes (&bc).unwrap ();
 	
 	assert_eq! (chunk.blocks [0].instructions [3], Inst::EqK (0, 1, false));
 	
 	let run = run_chunk;
 	
-	assert_eq! (run (&[""], &chunk), vec! [Value::from (1)]);
-	assert_eq! (run (&["", "93"], &chunk), vec! [Value::from (0)]);
-	assert_eq! (run (&["", "94"], &chunk), vec! [Value::from (1)]);
+	assert_eq! (run (&[""], chunk.clone ()), vec! [Value::from (1)]);
+	assert_eq! (run (&["", "93"], chunk.clone ()), vec! [Value::from (0)]);
+	assert_eq! (run (&["", "94"], chunk.clone ()), vec! [Value::from (1)]);
 }
 
 #[test]
 fn native_functions () {
-	fn add (l: &mut State) -> i32 {
+	fn add (_: &mut State) -> i32 {
 		0
 	}
 	
-	fn multiply (l: &mut State) -> i32 {
+	fn multiply (_: &mut State) -> i32 {
 		0
 	}
 	
-	fn greet (l: &mut State) -> i32 {
+	fn greet (_: &mut State) -> i32 {
 		0
 	}
 	
@@ -359,6 +355,25 @@ fn tables_2 () {
 	run_source (&[], src);
 }
 
+#[test]
+fn tailcall () {
+	use crate::instruction::Instruction;
+	
+	let src = r#"
+	return tonumber ("5")
+	"#;
+	
+	let bc = loader::compile_bytecode (src.as_bytes ().to_vec ());
+	let chunk = loader::parse_chunk_from_bytes (&bc).unwrap ();
+	
+	assert_eq! (chunk.blocks [0].instructions [3], Instruction::TailCall (0, 2, 1, false));
+	
+	let actual = run_chunk (&[], chunk);
+	let expected = vec! [Value::from (5)];
+	
+	assert_eq! (actual, expected);
+}
+
 #[test]
 fn value_size () {
 	// Per https://www.lua.org/doc/jucs05.pdf,

lunar_wave_vm/test_vectors/args.lua

@@ -0,0 +1,2 @@
+print (arg [0])
+print (arg [1])

lunar_wave_vm/tests/embedding.rs

@@ -0,0 +1,42 @@
+use lunar_wave_vm as lwvm;
+
+#[test]
+fn embedding () {
+	use lwvm::{
+		State,
+		Value,
+	};
+	
+	let src = br#"
+	return host_lib.add (14, 12)
+	"#;
+	
+	fn host_add (l: &mut State, num_args: usize) -> usize {
+		assert_eq! (num_args, 2);
+		let a = l.reg (0).as_int ().unwrap ();
+		let b = l.reg (1).as_int ().unwrap ();
+		*l.reg_mut (0) = Value::from (a + b + 1993);
+		1
+	}
+	
+	let bytecode = lwvm::compile_bytecode (src.to_vec ());
+	let mut rdr = std::io::Cursor::new (bytecode);
+	let chunk = lwvm::parse_chunk (&mut rdr).unwrap ();
+	
+	let host_lib = [
+		("add", Value::RsFunc (host_add)),
+	].into_iter ().map (|(k, v)| (k.to_string (), v));
+	
+	let env = [
+		("host_lib", Value::from_iter (host_lib.into_iter ())),
+	].into_iter ().map (|(k, v)| (k.to_string (), v));
+	
+	let upvalues = vec! [
+		Value::from_iter (env.into_iter ()),
+	];
+	
+	let mut vm = State::new (chunk, upvalues);
+	let output = vm.execute_chunk (&vec! []).unwrap ();
+	
+	assert_eq! (output, vec! [Value::from (2019)]);
+}

src/main.rs

@@ -1,118 +0,0 @@
-// cargo run -- --script test_vectors/fizz_buzz.lua
-
-mod instruction;
-mod loader;
-mod state;
-mod value;
-
-#[cfg (test)]
-mod tests;
-
-fn main () -> Result <(), state::StepError> {
-	use state::State;
-	
-	let mut list_bytecode = false;
-	let mut pipe_bytecode = false;
-	let mut script = None;
-	let mut breakpoints = vec![];
-	
-	let mut args = std::env::args ();
-	let exe_name = args.next ().unwrap ();
-	
-	while let Some (arg) = args.next () {
-		match arg.as_str () {
-			"--break" => {
-				let s = args.next ().unwrap ();
-				let (block_idx, program_counter) = s.split_once (":").unwrap ();
-				let block_idx = str::parse (block_idx).unwrap ();
-				let program_counter = str::parse (program_counter).unwrap ();
-				
-				breakpoints.push (state::Breakpoint {
-					block_idx,
-					program_counter,
-				});
-			},
-			"--list-bytecode" => list_bytecode = true,
-			"--pipe-bytecode" => pipe_bytecode = true,
-			"--script" => script = Some (args.next ().unwrap ()),
-			"--" => break,
-			_ => panic! ("can't parse args"),
-		}
-	}
-	
-	let chunk = if let Some (script) = script {
-		let bytecode = loader::compile_bytecode_from_file (&script);
-		let mut rdr = std::io::Cursor::new (bytecode);
-		loader::parse_chunk (&mut rdr).unwrap ()
-	}
-	else if pipe_bytecode {
-		let mut stdin = std::io::stdin ().lock ();
-		loader::parse_chunk (&mut stdin).unwrap ()
-	}
-	else {
-		unimplemented!();
-	};
-	
-	if list_bytecode {
-		dbg! (&chunk);
-	}
-	
-	let upvalues = State::upvalues_from_args ([exe_name].into_iter ().chain (args));
-	
-	let mut vm = State::new (&chunk, &upvalues);
-	if std::env::var("LWVM_DEBUG").is_ok() {
-		vm.debug_print = true;
-	}
-	
-	let mut in_break = false;
-	let mut last_input = String::new ();
-	
-	loop {
-		if in_break || breakpoints.iter ().any (|bp| vm.at_breakpoint (bp)) {
-			in_break = true;
-			dbg! (&vm.stack);
-			
-			let mut input = Default::default ();
-			std::io::stdin ().read_line (&mut input).unwrap ();
-			
-			let input = if input == "" {
-				&last_input
-			}
-			else {
-				last_input = input;
-				&last_input
-			};
-			
-			match input.as_str ().trim_end () {
-				"c" => in_break = false,
-				"q" => return Ok (()),
-				"registers" => {
-					dbg! (&vm.registers);
-					continue;
-				}
-				"s" => {
-					match vm.step ()? {
-						None => (),
-						Some (state::StepOutput::ChunkReturned (x)) => {
-							dbg! (x);
-							return Ok (());
-						},
-					}
-					continue;
-				},
-				x => { dbg! (x); },
-			}
-		}
-		
-		match vm.step ()? {
-			None => (),
-			Some (state::StepOutput::ChunkReturned (x)) => {
-				dbg! (x);
-				return Ok (());
-			},
-		}
-	}
-	
-	dbg! (vm);
-	panic! ("Hit max iterations before block returned");
-}