Files
nixjit/evaluator/nixjit_context/src/resolve.rs
2025-08-15 23:14:21 +08:00

266 lines
8.6 KiB
Rust

use std::cell::RefCell;
use derive_more::Unwrap;
use hashbrown::HashMap;
use nixjit_error::Result;
use nixjit_hir::Hir;
use nixjit_ir::{Const, ExprId, Param, StackIdx};
use nixjit_lir::{Lir, LookupResult, Resolve, ResolveContext};
use replace_with::replace_with_and_return;
use super::{Context, Pin};
#[derive(Clone)]
enum Scope<'ctx> {
/// A `let` binding scope, mapping variable names to their expression IDs.
Let(HashMap<String, ExprId>),
/// A function argument scope. `Some` holds the name of the argument set if present.
Arg(Option<String>),
Builtins(&'ctx HashMap<&'static str, ExprId>),
Repl(&'ctx HashMap<String, ExprId>),
}
/// Represents an expression at different stages of compilation.
#[derive(Debug, Unwrap)]
enum Ir {
/// An expression in the High-Level Intermediate Representation (HIR).
Hir(Hir),
/// An expression in the Low-Level Intermediate Representation (LIR).
Lir(Lir),
}
impl Ir {
unsafe fn unwrap_hir_unchecked(self) -> Hir {
if let Self::Hir(hir) = self {
hir
} else {
unsafe { core::hint::unreachable_unchecked() }
}
}
}
pub struct ResolveCtx<'ctx, 'bump> {
ctx: &'ctx mut Context<'bump>,
irs: Vec<Pin<'bump, RefCell<Ir>>>,
scopes: Vec<Scope<'ctx>>,
has_with: bool,
with_used: bool,
closures: Vec<(ExprId, Option<ExprId>, usize)>,
current_expr: Option<ExprId>,
}
impl<'ctx, 'bump> ResolveCtx<'ctx, 'bump> {
pub fn new(ctx: &'ctx mut Context<'bump>) -> Self {
let ctx_mut = unsafe { &mut *(ctx as *mut Context) };
Self {
scopes: vec![
Scope::Builtins(&ctx.global_scope),
Scope::Repl(&ctx.repl_scope),
],
has_with: false,
with_used: false,
irs: core::mem::take(&mut ctx.hirs)
.into_iter()
.map(|hir| Ir::Hir(hir).into())
.map(|ir| Pin::new_in(ir, ctx.bump))
.collect(),
ctx: ctx_mut,
closures: Vec::new(),
current_expr: None,
}
}
fn get_ir(&self, id: ExprId) -> &RefCell<Ir> {
let idx = unsafe { id.raw() } - self.ctx.lirs.len();
if cfg!(debug_assertions) {
self.irs.get(idx).unwrap()
} else {
unsafe { self.irs.get_unchecked(idx) }
}
}
fn get_ir_mut(&mut self, id: ExprId) -> &mut RefCell<Ir> {
let idx = unsafe { id.raw() } - self.ctx.lirs.len();
if cfg!(debug_assertions) {
self.irs.get_mut(idx).unwrap()
} else {
unsafe { self.irs.get_unchecked_mut(idx) }
}
}
fn add_dep(&mut self, from: ExprId, to: ExprId, count: &mut usize) -> StackIdx {
if let Some(&idx) = self.ctx.graph.edge_weight(from, to) {
idx
} else {
*count += 1;
let idx = unsafe { StackIdx::from_raw(*count - 1) };
assert_ne!(from, to);
self.ctx.graph.add_edge(from, to, idx);
idx
}
}
fn new_lir(&mut self, lir: Lir) -> ExprId {
self.irs.push(Pin::new_in(
RefCell::new(Ir::Lir(lir)),
self.ctx.bump,
));
unsafe { ExprId::from_raw(self.ctx.lirs.len() + self.irs.len() - 1) }
}
}
impl ResolveContext for ResolveCtx<'_, '_> {
fn resolve(&mut self, expr: ExprId) -> Result<()> {
let prev_expr = self.current_expr.replace(expr);
let result = unsafe {
let ctx = &mut *(self as *mut Self);
let ir = &mut self.get_ir_mut(expr);
if !matches!(ir.try_borrow().as_deref(), Ok(Ir::Hir(_))) {
return Ok(());
}
replace_with_and_return(
&mut *ir.borrow_mut(),
|| {
Ir::Hir(Hir::Const(Const {
val: nixjit_value::Const::Null,
}))
},
|ir| match ir.unwrap_hir_unchecked().resolve(ctx) {
Ok(lir) => (Ok(()), Ir::Lir(lir)),
Err(err) => (
Err(err),
Ir::Hir(Hir::Const(Const {
val: nixjit_value::Const::Null,
})),
),
},
)
};
self.current_expr = prev_expr;
result
}
fn resolve_call(&mut self, func: ExprId, arg: ExprId) -> Result<()> {
todo!()
}
fn resolve_root(mut self, expr: ExprId) -> Result<()> {
self.closures.push((expr, None, 0));
let ret = self.resolve(expr);
if ret.is_ok() {
self.ctx.lirs.extend(
self.irs
.into_iter()
.map(Pin::into_inner)
.map(RefCell::into_inner)
.map(Ir::unwrap_lir)
.map(|lir| crate::Pin::new_in(lir, self.ctx.bump)),
);
}
ret
}
fn lookup(&mut self, name: &str) -> LookupResult {
let mut closure_depth = 0;
// Then search from outer to inner scopes for dependencies
for scope in self.scopes.iter().rev() {
match scope {
Scope::Builtins(scope) => {
if let Some(&expr) = scope.get(&name) {
return LookupResult::Expr(expr);
}
}
Scope::Let(scope) | &Scope::Repl(scope) => {
if let Some(&dep) = scope.get(name) {
let (expr, _, deps) = unsafe { &mut *(self as *mut Self) }
.closures
.last_mut()
.unwrap();
let idx = self.add_dep(*expr, dep, deps);
return LookupResult::Stack(idx);
}
}
Scope::Arg(ident) => {
if ident.as_deref() == Some(name) {
// This is an outer function's parameter, treat as dependency
// We need to find the corresponding parameter expression to create dependency
// For now, we need to handle this case by creating a dependency to the parameter
let mut iter = unsafe { &mut *(self as *mut Self) }
.closures
.iter_mut()
.rev()
.take(closure_depth + 1)
.rev();
let Some((func, Some(arg), count)) = iter.next() else {
unreachable!()
};
let mut cur = self.add_dep(*func, *arg, count);
for (func, _, count) in iter {
let idx = self.new_lir(Lir::StackRef(cur));
cur = self.add_dep(*func, idx, count);
}
return LookupResult::Stack(cur);
}
closure_depth += 1;
}
}
}
if self.has_with {
self.with_used = true;
LookupResult::Unknown
} else {
LookupResult::NotFound
}
}
fn lookup_arg(&mut self) -> StackIdx {
let Some((func, Some(arg), count)) =
unsafe { &mut *(self as *mut Self) }.closures.last_mut()
else {
unreachable!()
};
self.add_dep(*func, *arg, count)
}
fn new_func(&mut self, body: ExprId, param: Param) {
self.ctx.funcs.insert(body, param);
}
fn with_let_env<T>(
&mut self,
bindings: HashMap<String, ExprId>,
f: impl FnOnce(&mut Self) -> T,
) -> T {
self.scopes.push(Scope::Let(bindings));
let res = f(self);
self.scopes.pop();
res
}
fn with_with_env<T>(&mut self, f: impl FnOnce(&mut Self) -> T) -> (bool, T) {
let has_with = self.has_with;
let with_used = self.with_used;
self.has_with = true;
self.with_used = false;
let res = f(self);
self.has_with = has_with;
(core::mem::replace(&mut self.with_used, with_used), res)
}
fn with_closure_env<T>(
&mut self,
func: ExprId,
ident: Option<String>,
f: impl FnOnce(&mut Self) -> T,
) -> T {
let arg = self.new_lir(Lir::Arg(nixjit_ir::Arg));
self.closures.push((func, Some(arg), 0));
self.scopes.push(Scope::Arg(ident));
let res = f(self);
self.scopes.pop();
self.closures.pop();
res
}
}