use super::{Compiler, Symbol};
use anyhow::Result;
use dynamic::{Dynamic, Type};
use parser::{BinaryOp, Expr, ExprKind, PatternKind, Span, Stmt, StmtKind};
impl Compiler {
fn merge_return_type(left: Option<Type>, right: Type) -> Type {
match left {
Some(left) if left == right => left,
Some(left) => left + right,
None => right,
}
}
fn infer_return_type(&mut self, stmt: &Stmt) -> Result<Option<Type>> {
match &stmt.kind {
StmtKind::Return(Some(expr)) => Ok(Some(self.infer_expr(expr)?)),
StmtKind::Return(None) => Ok(Some(Type::Void)),
StmtKind::Block(stmts) => {
let mut ret = None;
for stmt in stmts {
if let Some(ty) = self.infer_return_type(stmt)? {
ret = Some(Self::merge_return_type(ret, ty));
}
}
Ok(ret)
}
StmtKind::If { cond, then_body, else_body } => {
let cond_ty = self.infer_expr(cond)?;
if cond_ty != Type::Bool {
return Err(Self::semantic_error(cond.span, "条件表达式必须是布尔类型"));
}
let mut ret = self.infer_return_type(then_body)?;
if let Some(body) = else_body {
if let Some(ty) = self.infer_return_type(body)? {
ret = Some(Self::merge_return_type(ret, ty));
}
}
Ok(ret)
}
StmtKind::While { cond, body } => {
let cond_ty = self.infer_expr(cond)?;
if cond_ty != Type::Bool {
return Err(Self::semantic_error(cond.span, "条件表达式必须是布尔类型"));
}
self.infer_return_type(body)
}
StmtKind::Loop(body) => self.infer_return_type(body),
StmtKind::For { pat, range, body } => {
if let PatternKind::Var { idx, .. } = &pat.kind {
let ty = self.infer_expr(range)?;
self.set_ty(*idx, ty);
} else if let PatternKind::Tuple(pats) = &pat.kind {
let ty = self.infer_expr(range)?;
assert!(ty.is_any());
for pat in pats {
if let Some(idx) = pat.var() {
self.set_ty(idx, Type::Any);
}
}
}
self.infer_return_type(body)
}
StmtKind::Let { .. } => {
self.infer_stmt(stmt)?;
Ok(None)
}
StmtKind::Expr(expr, close) => {
let ty = self.infer_expr(expr)?;
Ok(if *close { None } else { Some(ty) })
}
_ => {
self.infer_stmt(stmt)?;
Ok(None)
}
}
}
pub fn infer_expr(&mut self, expr: &Expr) -> Result<Type> {
match &expr.kind {
ExprKind::Value(Dynamic::Null) => Ok(Type::Any),
ExprKind::Value(v) => Ok(v.get_type()),
ExprKind::Var(idx) => {
let idx = self.top() + (*idx as usize);
if idx < self.tys.len() { self.symbols.get_type(&self.tys[idx]) } else { Ok(Type::Any) }
}
ExprKind::Id(id, _) => match self.symbols.get_symbol(*id)?.1 {
Symbol::Const { ty, .. } => Ok(ty.clone()),
Symbol::Static { ty, .. } => Ok(ty.clone()),
Symbol::Struct(ty, _) => Ok(ty.clone()),
Symbol::Fn { .. } => Ok(Type::Symbol { id: *id, params: Vec::new() }),
Symbol::Native(ty) => Ok(ty.clone()),
s => Err(Self::semantic_error(expr.span, format!("符号 {:?} 不是变量、常量、静态变量、结构体", s))),
},
ExprKind::AssocId { id, params } => Ok(Type::Symbol { id: *id, params: params.clone() }),
ExprKind::Unary { value, .. } => self.infer_expr(value.as_ref()),
ExprKind::Binary { left, op, right } => {
let assign_idx = if op.is_assign() { if let ExprKind::Var(idx) = &left.kind { Some(*idx) } else { None } } else { None };
let ty = if op.is_logic() {
let left_ty = self.infer_expr(left)?;
if matches!(op, BinaryOp::And | BinaryOp::Or) && left_ty.is_any() { Type::Any } else { Type::Bool }
} else if op == &BinaryOp::Idx {
let left_ty = self.infer_expr(left)?;
if let Type::Array(elem_ty, _) = left_ty {
(*elem_ty).clone()
} else if let Type::Vec(elem_ty, _) = left_ty {
(*elem_ty).clone()
} else {
let left_ty = self.symbols.get_type(&left_ty)?;
let right_ty = if right.is_value() || right.is_const() {
let right_value = if let ExprKind::Const(c) = &right.kind { self.consts[*c].clone() } else { right.clone().value()? };
if right_value.is_str() {
if left_ty.is_any() {
return Ok(Type::Any);
}
if let Ok(field) = self.symbols.get_field(&left_ty, right_value.as_str()) {
return if let Type::Fn { ret, .. } = field.1 { Ok(ret.as_ref().clone()) } else { Ok(field.1.clone()) };
}
} else if let Type::Struct { fields, .. } = &left_ty
&& let Some(idx) = right_value.as_int()
{
return fields.get(idx as usize).map(|(_, ty)| ty.clone()).ok_or_else(|| Self::semantic_error(right.span, format!("结构字段索引越界 {}", idx)));
}
right_value.get_type()
} else {
self.infer_expr(right)?
};
if right_ty.is_int() || right_ty.is_uint() {
if left_ty.is_any() {
return Ok(Type::Any);
}
let (_, s) = self.symbols.get_field(&left_ty, "get_idx")?;
let fn_ty = self.symbols.get_type(&s)?;
return if let Type::Fn { ret, .. } = &fn_ty { Ok(ret.as_ref().clone()) } else { Ok(fn_ty) };
}
if left_ty.is_any() {
return Ok(Type::Any);
}
Type::Any
}
} else {
let right_ty = self.infer_expr(right)?;
if op == &BinaryOp::Assign { right_ty } else { self.infer_expr(left)? + right_ty }
};
assign_idx.map(|idx| self.set_ty(idx, ty.clone()));
Ok(ty)
}
ExprKind::Call { obj, params } => {
if let ExprKind::AssocId { id, params: generic_args } = &obj.kind {
let mut args = Vec::new();
for p in params {
args.push(self.infer_expr(p)?);
}
self.infer_fn_with_params(*id, &args, generic_args)
} else if let ExprKind::TypedMethod { obj: target, ty, name } = &obj.kind {
let base_name = match ty {
Type::Ident { name, .. } => name.clone(),
Type::Symbol { id, .. } => self.symbols.get_symbol(*id)?.0.clone(),
_ => return Ok(Type::Any),
};
let id = self.symbols.get_id(&format!("{}::{}", base_name, name))?;
let mut args = vec![self.infer_expr(target)?];
for p in params {
args.push(self.infer_expr(p)?);
}
self.infer_fn(id, &args)
} else if let ExprKind::Id(id, obj_expr) = &obj.kind {
let mut args: Vec<Type> = if let Some(obj) = obj_expr { vec![self.infer_expr(obj)?] } else { Vec::new() };
for p in params {
args.push(self.infer_expr(p)?);
}
self.infer_fn(*id, &args)
} else if obj.is_idx() {
let (target, _, method) = obj.clone().binary().unwrap();
let ty = self.infer_expr(&target)?;
if let Some(method) = self.get_value(&method) {
let method = method.as_str();
let fn_ty = match self.get_field(&ty, method) {
Ok((_, fn_ty)) => fn_ty,
Err(_) => {
let id = self.symbols.get_id(method)?;
if self.symbols.get_symbol(id)?.1.is_fn() {
Type::Symbol { id, params: Vec::new() }
} else {
return Err(Self::semantic_error(obj.span, format!("符号 {method} 不是函数")));
}
}
};
if let Type::Symbol { id, .. } = fn_ty {
let mut args = vec![ty];
for p in params {
args.push(self.infer_expr(p)?);
}
self.infer_fn(id, &args)
} else {
Ok(fn_ty)
}
} else {
Ok(Type::Any)
}
} else if let ExprKind::Var(idx) = &obj.kind {
let idx = self.top() + (*idx as usize);
if idx < self.tys.len()
&& let Type::Symbol { id, .. } = self.tys[idx]
{
let mut args = Vec::new();
for p in params {
args.push(self.infer_expr(p)?);
}
self.infer_fn(id, &args)
} else {
Ok(Type::Any)
}
} else if obj.is_value() {
Ok(Type::Void)
} else {
Ok(Type::Any)
}
}
ExprKind::Typed { ty, .. } => Ok(ty.clone()),
ExprKind::Stmt(stmt) => self.infer_stmt(stmt),
ExprKind::Range { start, stop, .. } => {
let start_ty = self.infer_expr(start)?;
let stop_ty = self.infer_expr(stop)?;
Ok(if start_ty.is_any() {
stop_ty
} else if stop_ty.is_any() {
start_ty
} else {
stop_ty
})
}
_ => Ok(Type::Any),
}
}
fn get_fn_tys(&mut self, tys: &[Type], arg_tys: &[Type]) -> Result<Vec<Type>> {
let mut fn_tys = Vec::new();
for (i, ty) in tys.iter().enumerate() {
if !ty.is_any() {
fn_tys.push(ty.clone());
} else if let Some(arg_ty) = arg_tys.get(i) {
fn_tys.push(self.symbols.get_type(arg_ty)?);
} else {
fn_tys.push(Type::Any);
}
}
Ok(fn_tys)
}
pub fn infer_fn(&mut self, id: u32, arg_tys: &[Type]) -> Result<Type> {
self.infer_fn_with_params(id, arg_tys, &[])
}
pub fn infer_fn_with_params(&mut self, id: u32, arg_tys: &[Type], generic_args: &[Type]) -> Result<Type> {
let (name, s) = self.symbols.get_symbol(id).map(|(n, s)| (n.clone(), s.clone()))?;
if let Symbol::Fn { ty, args, generic_params, cap, body, .. } = s {
if let Type::Fn { tys, ret: _ } = ty {
let inferred_generic_args = if generic_args.is_empty() { crate::infer_generic_args_from_types(&generic_params, &tys, arg_tys) } else { generic_args.to_vec() };
let generic_args = if generic_params.is_empty() { &[] } else { inferred_generic_args.as_slice() };
let tys = if generic_params.is_empty() { tys } else { tys.iter().map(|ty| crate::substitute_type(ty, &generic_params, generic_args)).collect() };
let body = if generic_params.is_empty() { body.as_ref().clone() } else { crate::substitute_stmt(body.as_ref(), &generic_params, generic_args) };
let fn_tys = self.get_fn_tys(&tys, arg_tys)?;
let body = if generic_params.is_empty() {
body
} else {
let mut compile_tys = tys.clone();
let mut compile_cap = cap.clone();
let saved_state = self.take_local_state();
let compiled = self.compile_fn(&args, &mut compile_tys, body, &mut compile_cap);
self.restore_local_state(saved_state);
Stmt::new(StmtKind::Block(compiled?), Span::default())
};
if let Some(fns) = self.fns.get_mut(&id) {
for f in fns.iter() {
if f.0 == generic_args && f.1 == fn_tys {
return Ok(f.2.clone());
}
}
fns.push((generic_args.to_vec(), fn_tys.clone(), Type::Any));
} else {
self.fns.insert(id, vec![(generic_args.to_vec(), fn_tys.clone(), Type::Any)]);
}
let top = self.tys.len();
self.tys.append(&mut fn_tys.clone());
for c in cap.vars.iter() {
self.tys.push(self.tys[self.top() + *c].clone());
}
self.frames.push(top);
let ret_ty = self.infer_return_type(&body).map(|ty| ty.unwrap_or(Type::Void));
if let Some(top) = self.frames.pop() {
self.tys.truncate(top);
}
let ret_ty = match ret_ty {
Ok(ret_ty) => ret_ty,
Err(err) => {
log::error!("infer_fn {} failed: {:?}", name, err);
let should_remove = self
.fns
.get_mut(&id)
.map(|fns| {
fns.retain(|item| item.0 != generic_args || item.1 != fn_tys || item.2 != Type::Any);
fns.is_empty()
})
.unwrap_or(false);
if should_remove {
self.fns.remove(&id);
}
return Err(err);
}
};
self.fns.get_mut(&id).map(|f| {
f.iter_mut().find(|item| item.0 == generic_args && item.1 == fn_tys).map(|item| item.2 = ret_ty.clone());
});
Ok(ret_ty)
} else {
Ok(Type::Any)
}
} else if let Symbol::Native(f) = s {
if let Type::Fn { ret, .. } = f { Ok((*ret).clone()) } else { Ok(Type::Any) }
} else if matches!(s, Symbol::Null) {
Ok(Type::Any)
} else {
Err(Self::semantic_error(Span::default(), format!("符号 {:?} 不是函数", name)))
}
}
pub fn infer_stmt(&mut self, stmt: &Stmt) -> Result<Type> {
match &stmt.kind {
StmtKind::Expr(expr, close) => {
if !close {
self.infer_expr(expr)
} else {
self.infer_expr(expr)?;
Ok(Type::Void)
}
}
StmtKind::Return(expr) => {
if let Some(e) = expr {
self.infer_expr(e)
} else {
Ok(Type::Void)
}
}
StmtKind::Block(stmts) => {
for (idx, stmt) in stmts.iter().enumerate() {
let ty = self.infer_stmt(stmt)?;
if stmt.is_return() || idx == stmts.len() - 1 {
return Ok(ty);
}
}
Ok(Type::Void)
}
StmtKind::If { then_body, else_body, .. } => {
let then_ty = self.infer_stmt(then_body)?;
if let Some(e) = else_body {
let else_ty = self.infer_stmt(e)?;
if then_ty != else_ty {
log::info!("then 和 else 有不同类型 {:?} {:?}", then_ty, else_ty);
return Ok(if then_ty.is_any() { else_ty } else { then_ty });
}
}
if else_body.is_none() {
return Ok(Type::Void);
}
Ok(then_ty)
}
StmtKind::While { cond, body } => {
let cond_ty = self.infer_expr(cond)?;
if cond_ty != Type::Bool {
return Err(Self::semantic_error(cond.span, "条件表达式必须是布尔类型"));
}
self.infer_stmt(body)
}
StmtKind::For { pat, range, body } => {
if let PatternKind::Var { idx, .. } = &pat.kind {
let ty = self.infer_expr(range)?;
self.set_ty(*idx, ty);
} else if let PatternKind::Tuple(pats) = &pat.kind {
let ty = self.infer_expr(range)?;
assert!(ty.is_any());
for pat in pats {
if let Some(idx) = pat.var() {
self.set_ty(idx, Type::Any);
}
}
}
self.infer_stmt(body)
}
StmtKind::Let { pat, value } => {
let expr_ty = if let StmtKind::Expr(expr, _) = &value.kind { self.infer_expr(expr)? } else { self.infer_stmt(value)? };
if let PatternKind::Ident { ty, .. } = &pat.kind {
let annotated_ty = self.symbols.get_type(ty)?;
if annotated_ty.is_any() {
self.add_ty(expr_ty);
} else {
self.add_ty(annotated_ty);
}
} else if let PatternKind::Var { idx, .. } = &pat.kind {
self.set_ty(*idx, expr_ty);
} else if matches!(pat.kind, PatternKind::Wildcard) {
self.add_ty(expr_ty);
}
Ok(Type::Void)
}
_ => Ok(Type::Void),
}
}
}