from-scratch/stages/lisp0/test.rs
2026-07-05 08:47:29 +02:00

569 lines
17 KiB
Rust

#![feature(allocator_api, box_as_ptr)]
unsafe extern "C" {
fn heap_alloc(size: usize, align: usize) -> *mut u8;
fn heap_dealloc(ptr: *mut u8, size: usize, align: usize);
fn init_source(source: *mut Source, fd: i32) -> *mut Source;
fn getc() -> SourceIterResult;
fn peekc() -> SourceIterResult;
fn eval(expr: Object, env: Object) -> Object;
fn init_env() -> Object;
fn parse_next_token() -> Object;
#[link_name = "ifile"]
static mut IFILE: Source;
#[link_name = "nil"]
static NIL: ();
#[link_name = "env"]
static GENV: ();
}
use std::ptr::NonNull;
#[repr(C)]
#[derive(Copy, Clone)]
struct Object(*mut ());
impl Object {
const BYTE: u8 = 0;
const NUM: u8 = 1;
const PRIM: u8 = 2;
const CONS: u8 = 3;
const CLOS: u8 = 4;
const ATOM: u8 = 5;
const ARR: u8 = 6;
const NUM_MAGIC: u32 = 0x5555;
fn is_nil(&self) -> bool {
self.0 as *const () == &raw const NIL
}
fn tag(&self) -> u8 {
self.0.addr() as u8 & 0b111
}
fn bits(&self) -> usize {
self.0.addr()
}
fn ptr(&self) -> *mut () {
self.0.map_addr(|addr| addr & !0b111)
}
fn is_g_env(&self) -> bool {
self.0 as *const () == unsafe { *ENV_INIT }.0 as *const ()
}
}
#[derive(Copy, Clone)]
struct DebugObjectExplicitGenv(Object);
impl std::fmt::Debug for DebugObjectExplicitGenv {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
#[repr(C)]
struct Cons {
refc: u64,
car: Object,
cdr: Object,
}
if self.0.is_g_env() {
let mut proxy = unsafe {
Cons {
refc: 1,
car: self.0.ptr().byte_add(8).cast::<Object>().read(),
cdr: self.0.ptr().byte_add(16).cast::<Object>().read(),
}
};
let obj =
Object((&raw const proxy as *mut ()).map_addr(|addr| addr | Object::CONS as usize));
write!(f, "{:?}", obj)
} else {
return write!(f, "{:?}", self.0);
}
}
}
impl std::fmt::Debug for Object {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
if self.is_nil() {
return write!(f, "nil");
}
if self.is_g_env() {
return write!(f, "#<g_env>");
}
fn fmt_byte(byte: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let c = unsafe { byte.cast::<u8>().read() };
if c.is_ascii_graphic() || c == b' ' {
write!(f, "'{}'", c as char)
} else {
write!(f, "'\\x{:02x}'", c)
}
}
fn fmt_num(num: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let num_ptr = unsafe { num.cast::<i64>().read() };
write!(f, "{}", num_ptr)
}
fn fmt_prim(prim: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let prim_ptr = unsafe { prim.cast::<*const ()>().read() };
write!(f, "#<prim {:?}>", prim_ptr)
}
fn fmt_cons(cons: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let (car, cdr) = unsafe { cons.cast::<(Object, Object)>().read() };
if !cdr.is_nil() && cdr.tag() == Object::CONS {
// If the cdr is a cons cell, we can print it as a list
write!(f, "({car:?}")?;
let mut cdr = cdr;
while !cdr.is_nil() && cdr.tag() == Object::CONS {
let (next_car, next_cdr) =
unsafe { cdr.ptr().byte_add(8).cast::<(Object, Object)>().read() };
write!(f, " {next_car:?}")?;
cdr = next_cdr;
}
if cdr.is_nil() {
write!(f, ")")
} else {
write!(f, " {cdr:?})")
}
} else {
write!(f, "({car:?} . {cdr:?})")
}
}
fn fmt_clos(clos: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let (car, env) = unsafe { clos.cast::<(Object, Object)>().read() };
assert_eq!(
car.tag(),
Object::CONS,
"Expected a pair for lambda cdr, got tag {}",
car.tag()
);
let (params, body) = unsafe { car.ptr().cast::<(Object, Object)>().read() };
write!(f, "λ ")?;
if env.0 as *const () == &raw const NIL {
write!(f, " #<g_env> ++ ")
} else {
write!(f, " {env:?} ++ ")
}
}
fn fmt_atom(atom: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let (ptr, len) = unsafe {
(
atom.cast::<*const u8>().read(),
atom.byte_add(8).cast::<usize>().read(),
)
};
let slice = unsafe { core::slice::from_raw_parts(ptr, len) };
let string = core::str::from_utf8(slice).unwrap_or("<invalid utf-8>");
write!(f, "'{string}")
}
fn fmt_arr(arr: *const (), f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let len = unsafe { arr.cast::<u32>().read() } as usize;
let cap = unsafe { arr.byte_add(4).cast::<u32>().read() } as usize;
let data = unsafe { arr.byte_add(8).cast::<Object>().read() };
let data_ptr = data.ptr();
let data_tag = data.tag();
match data_tag {
Object::BYTE => {
let slice = unsafe { core::slice::from_raw_parts(data_ptr as *const u8, len) };
let string = core::str::from_utf8(slice).unwrap_or("<invalid utf-8>");
write!(f, "\"{string}\"")
}
_ => {
const SIZES: [usize; 7] = [1, 8, 8, 16, 16, 16, 16];
let _fn = match data_tag {
Object::BYTE => fmt_byte,
Object::NUM => fmt_num,
Object::PRIM => fmt_prim,
Object::CONS => fmt_cons,
Object::CLOS => fmt_clos,
Object::ATOM => fmt_atom,
Object::ARR => fmt_arr,
_ => unreachable!(),
};
write!(f, "[")?;
for i in 0..len {
let elem = unsafe { data_ptr.byte_add(i * SIZES[data_tag as usize]) };
_fn(elem, f)?;
if i + 1 < len {
write!(f, ", ")?;
}
}
write!(f, "]")
}
}
}
unsafe {
match self.tag() {
Object::BYTE => {
let byte = self.ptr().addr() >> 8 as u8;
fmt_byte(&raw const byte as _, f)
}
Object::NUM => {
let MASK: usize = 0x5555_0000_0000_0000 | Object::NUM as usize;
if self.bits() & MASK == MASK {
let num = (self.bits() >> 8) as i32 as i64;
fmt_num(&raw const num as _, f)
} else {
fmt_num(self.ptr().byte_add(8), f)
}
}
Object::PRIM => fmt_prim(self.ptr().byte_add(8), f),
Object::CONS => fmt_cons(self.ptr().byte_add(8), f),
Object::CLOS => fmt_clos(self.ptr().byte_add(8), f),
Object::ATOM => fmt_atom(self.ptr().byte_add(8), f),
Object::ARR => fmt_arr(self.ptr().byte_add(8), f),
_ => write!(f, "#<unknown tag {}>", self.tag()),
}
}
}
}
#[repr(C)]
struct Source {
fd: i32,
peeked: (u8, u8),
buf: NonNull<u8>,
buf_cur: usize,
buf_end: usize,
}
#[repr(align(8))]
struct Bool(bool);
impl core::ops::Deref for Bool {
type Target = bool;
fn deref(&self) -> &Self::Target {
&self.0
}
}
#[repr(C)]
struct SourceIterResult {
c: u8,
some: Bool,
}
struct HeapAlloc;
unsafe impl std::alloc::Allocator for HeapAlloc {
fn allocate(
&self,
layout: std::alloc::Layout,
) -> Result<std::ptr::NonNull<[u8]>, std::alloc::AllocError> {
let ptr = unsafe { heap_alloc(layout.size(), layout.align()) };
if ptr.is_null() {
Err(std::alloc::AllocError)
} else {
Ok(std::ptr::NonNull::slice_from_raw_parts(
std::ptr::NonNull::new(ptr).unwrap(),
layout.size(),
))
}
}
unsafe fn deallocate(&self, ptr: std::ptr::NonNull<u8>, layout: std::alloc::Layout) {
heap_dealloc(ptr.as_ptr(), layout.size(), layout.align());
}
}
static mut ENV_INIT: std::cell::LazyCell<Object> =
std::cell::LazyCell::new(|| unsafe { init_env() });
#[cfg(test)]
mod tests {
use super::*;
use std::fs::File;
use std::mem::ManuallyDrop;
use std::os::fd::AsRawFd;
#[test]
fn test_heap_alloc_dealloc() {
let small = Box::new_in(42u8, HeapAlloc);
let ptr_sized = Box::new_in(42usize, HeapAlloc);
let big = Box::new_in([0u8; 48], HeapAlloc);
let large = Box::new_in([0u8; 1024], HeapAlloc);
let page_sized = Box::new_in([0u8; 4096], HeapAlloc);
assert_eq!(*small, 42);
assert_ne!(
Box::as_ptr(&small) as *const (),
Box::as_ptr(&ptr_sized) as *const ()
);
let small_ptr = Box::as_ptr(&small) as *const ();
drop(small);
let small2 = Box::new_in(43u8, HeapAlloc);
assert_eq!(*small2, 43);
assert_eq!(small_ptr, Box::as_ptr(&small2) as *const ());
}
#[test]
fn source() {
let mut file = std::fs::File::open("lisp1.asm").unwrap();
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let SourceIterResult { c, some } = getc();
assert!(*some);
assert_eq!(c, b'd');
let SourceIterResult { c, some } = peekc();
assert!(*some);
assert_eq!(c, b'e');
let SourceIterResult { c, some } = getc();
assert!(*some);
assert_eq!(c, b'e');
}
}
#[test]
fn parse_list() {
let file = ManuallyDrop::new(File::open("tests/list.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn parse_quoted_list() {
let file = ManuallyDrop::new(File::open("tests/quoted-list.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn parse_string() {
let file = ManuallyDrop::new(File::open("tests/string.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn parse_atom() {
let file = ManuallyDrop::new(File::open("tests/atom.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn parse_pair() {
let file = ManuallyDrop::new(File::open("tests/pair.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn parse_big_number() {
let file = ManuallyDrop::new(File::open("tests/big-number.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let obj = parse_next_token();
println!("{:?}", obj);
}
}
#[test]
fn global_env() {
unsafe {
let env = unsafe { *ENV_INIT };
println!("{:?}", DebugObjectExplicitGenv(env));
}
}
#[test]
fn eval_add() {
let file = ManuallyDrop::new(File::open("tests/add.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_let() {
let file = ManuallyDrop::new(File::open("tests/let.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_letstar() {
let file = ManuallyDrop::new(File::open("tests/letstar.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_print() {
let file = ManuallyDrop::new(File::open("tests/print.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_if() {
let file = ManuallyDrop::new(File::open("tests/if.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_define() {
let file = ManuallyDrop::new(File::open("tests/define.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_typeof() {
let file = ManuallyDrop::new(File::open("tests/typeof.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_eval() {
let file = ManuallyDrop::new(File::open("tests/eval.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_comment() {
let file = ManuallyDrop::new(File::open("tests/comment.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
eprintln!("parsed: {:?}", expr);
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_mapcar() {
let file = ManuallyDrop::new(File::open("tests/mapcar.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_setq() {
let file = ManuallyDrop::new(File::open("tests/setq.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn eval_equal() {
let file = ManuallyDrop::new(File::open("tests/equal.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
#[test]
fn complex() {
let file = ManuallyDrop::new(File::open("tests/print-args.l").unwrap());
unsafe {
init_source(&raw mut IFILE, file.as_raw_fd());
let expr = parse_next_token();
let env = unsafe { *ENV_INIT };
let result = eval(expr, env);
eprint!("done: ");
eprintln!("{result:?}");
}
}
}