remember where fields resolve to during inference

This commit is contained in:
Aleksey Kladov 2019-01-25 20:02:53 +03:00
parent dc5ecf4469
commit 0044514a4e

View file

@ -732,8 +732,10 @@ pub(super) fn type_for_field(db: &impl HirDatabase, field: StructField) -> Ty {
/// The result of type inference: A mapping from expressions and patterns to types.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct InferenceResult {
/// For each method call expr, record the function it resolved to.
/// For each method call expr, records the function it resolves to.
method_resolutions: FxHashMap<ExprId, Function>,
/// For each field access expr, records the field it resolves to.
field_resolutions: FxHashMap<ExprId, StructField>,
type_of_expr: ArenaMap<ExprId, Ty>,
type_of_pat: ArenaMap<PatId, Ty>,
}
@ -770,6 +772,7 @@ struct InferenceContext<'a, D: HirDatabase> {
impl_block: Option<ImplBlock>,
var_unification_table: InPlaceUnificationTable<TypeVarId>,
method_resolutions: FxHashMap<ExprId, Function>,
field_resolutions: FxHashMap<ExprId, StructField>,
type_of_expr: ArenaMap<ExprId, Ty>,
type_of_pat: ArenaMap<PatId, Ty>,
/// The return type of the function being inferred.
@ -861,6 +864,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
) -> Self {
InferenceContext {
method_resolutions: FxHashMap::default(),
field_resolutions: FxHashMap::default(),
type_of_expr: ArenaMap::default(),
type_of_pat: ArenaMap::default(),
var_unification_table: InPlaceUnificationTable::new(),
@ -886,6 +890,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
}
InferenceResult {
method_resolutions: mem::replace(&mut self.method_resolutions, Default::default()),
field_resolutions: mem::replace(&mut self.field_resolutions, Default::default()),
type_of_expr: expr_types,
type_of_pat: pat_types,
}
@ -899,6 +904,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
self.method_resolutions.insert(expr, func);
}
fn write_field_resolution(&mut self, expr: ExprId, field: StructField) {
self.field_resolutions.insert(expr, field);
}
fn write_pat_ty(&mut self, pat: PatId, ty: Ty) {
self.type_of_pat.insert(pat, ty);
}
@ -1251,9 +1260,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
ty
}
fn infer_expr(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
let body = Arc::clone(&self.body); // avoid borrow checker problem
let ty = match &body[expr] {
let ty = match &body[tgt_expr] {
Expr::Missing => Ty::Unknown,
Expr::If {
condition,
@ -1344,7 +1353,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
let resolved = receiver_ty.clone().lookup_method(self.db, method_name);
let method_ty = match resolved {
Some(func) => {
self.write_method_resolution(expr, func);
self.write_method_resolution(tgt_expr, func);
self.db.type_for_def(func.into())
}
None => Ty::Unknown,
@ -1389,7 +1398,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
expected.ty
}
Expr::Path(p) => self.infer_path_expr(expr, p).unwrap_or(Ty::Unknown),
Expr::Path(p) => self.infer_path_expr(tgt_expr, p).unwrap_or(Ty::Unknown),
Expr::Continue => Ty::Never,
Expr::Break { expr } => {
if let Some(expr) = expr {
@ -1436,9 +1445,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
def_id: AdtDef::Struct(s),
ref substs,
..
} => s
.field(self.db, name)
.map(|field| field.ty(self.db).subst(substs)),
} => s.field(self.db, name).map(|field| {
self.write_field_resolution(tgt_expr, field);
field.ty(self.db).subst(substs)
}),
_ => None,
})
.unwrap_or(Ty::Unknown);
@ -1545,7 +1555,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
let ty = self.insert_type_vars_shallow(ty);
self.unify(&ty, &expected.ty);
let ty = self.resolve_ty_as_possible(ty);
self.write_expr_ty(expr, ty.clone());
self.write_expr_ty(tgt_expr, ty.clone());
ty
}