bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer/unify.rs')
-rw-r--r--crates/hir-ty/src/infer/unify.rs48
1 files changed, 22 insertions, 26 deletions
diff --git a/crates/hir-ty/src/infer/unify.rs b/crates/hir-ty/src/infer/unify.rs
index 0fb71135b4..0a68a9f3b5 100644
--- a/crates/hir-ty/src/infer/unify.rs
+++ b/crates/hir-ty/src/infer/unify.rs
@@ -10,7 +10,6 @@ use chalk_solve::infer::ParameterEnaVariableExt;
use either::Either;
use ena::unify::UnifyKey;
use hir_expand::name;
-use stdx::never;
use triomphe::Arc;
use super::{InferOk, InferResult, InferenceContext, TypeError};
@@ -92,15 +91,10 @@ pub(crate) fn unify(
let vars = Substitution::from_iter(
Interner,
tys.binders.iter(Interner).map(|it| match &it.kind {
- chalk_ir::VariableKind::Ty(_) => {
- GenericArgData::Ty(table.new_type_var()).intern(Interner)
- }
- chalk_ir::VariableKind::Lifetime => {
- GenericArgData::Ty(table.new_type_var()).intern(Interner)
- } // FIXME: maybe wrong?
- chalk_ir::VariableKind::Const(ty) => {
- GenericArgData::Const(table.new_const_var(ty.clone())).intern(Interner)
- }
+ chalk_ir::VariableKind::Ty(_) => table.new_type_var().cast(Interner),
+ // FIXME: maybe wrong?
+ chalk_ir::VariableKind::Lifetime => table.new_type_var().cast(Interner),
+ chalk_ir::VariableKind::Const(ty) => table.new_const_var(ty.clone()).cast(Interner),
}),
);
let ty1_with_vars = vars.apply(tys.value.0.clone(), Interner);
@@ -111,10 +105,10 @@ pub(crate) fn unify(
// default any type vars that weren't unified back to their original bound vars
// (kind of hacky)
let find_var = |iv| {
- vars.iter(Interner).position(|v| match v.interned() {
- chalk_ir::GenericArgData::Ty(ty) => ty.inference_var(Interner),
- chalk_ir::GenericArgData::Lifetime(lt) => lt.inference_var(Interner),
- chalk_ir::GenericArgData::Const(c) => c.inference_var(Interner),
+ vars.iter(Interner).position(|v| match v.data(Interner) {
+ GenericArgData::Ty(ty) => ty.inference_var(Interner),
+ GenericArgData::Lifetime(lt) => lt.inference_var(Interner),
+ GenericArgData::Const(c) => c.inference_var(Interner),
} == Some(iv))
};
let fallback = |iv, kind, default, binder| match kind {
@@ -149,6 +143,9 @@ pub(crate) struct InferenceTable<'a> {
var_unification_table: ChalkInferenceTable,
type_variable_table: Vec<TypeVariableFlags>,
pending_obligations: Vec<Canonicalized<InEnvironment<Goal>>>,
+ /// Double buffer used in [`Self::resolve_obligations_as_possible`] to cut down on
+ /// temporary allocations.
+ resolve_obligations_buffer: Vec<Canonicalized<InEnvironment<Goal>>>,
}
pub(crate) struct InferenceTableSnapshot {
@@ -165,6 +162,7 @@ impl<'a> InferenceTable<'a> {
var_unification_table: ChalkInferenceTable::new(),
type_variable_table: Vec::new(),
pending_obligations: Vec::new(),
+ resolve_obligations_buffer: Vec::new(),
}
}
@@ -516,10 +514,10 @@ impl<'a> InferenceTable<'a> {
pub(crate) fn resolve_obligations_as_possible(&mut self) {
let _span = profile::span("resolve_obligations_as_possible");
let mut changed = true;
- let mut obligations = Vec::new();
- while changed {
- changed = false;
+ let mut obligations = mem::take(&mut self.resolve_obligations_buffer);
+ while mem::take(&mut changed) {
mem::swap(&mut self.pending_obligations, &mut obligations);
+
for canonicalized in obligations.drain(..) {
if !self.check_changed(&canonicalized) {
self.pending_obligations.push(canonicalized);
@@ -534,6 +532,8 @@ impl<'a> InferenceTable<'a> {
self.register_obligation_in_env(uncanonical);
}
}
+ self.resolve_obligations_buffer = obligations;
+ self.resolve_obligations_buffer.clear();
}
pub(crate) fn fudge_inference<T: TypeFoldable<Interner>>(
@@ -611,9 +611,9 @@ impl<'a> InferenceTable<'a> {
fn check_changed(&mut self, canonicalized: &Canonicalized<InEnvironment<Goal>>) -> bool {
canonicalized.free_vars.iter().any(|var| {
let iv = match var.data(Interner) {
- chalk_ir::GenericArgData::Ty(ty) => ty.inference_var(Interner),
- chalk_ir::GenericArgData::Lifetime(lt) => lt.inference_var(Interner),
- chalk_ir::GenericArgData::Const(c) => c.inference_var(Interner),
+ GenericArgData::Ty(ty) => ty.inference_var(Interner),
+ GenericArgData::Lifetime(lt) => lt.inference_var(Interner),
+ GenericArgData::Const(c) => c.inference_var(Interner),
}
.expect("free var is not inference var");
if self.var_unification_table.probe_var(iv).is_some() {
@@ -690,14 +690,10 @@ impl<'a> InferenceTable<'a> {
.fill(|it| {
let arg = match it {
ParamKind::Type => self.new_type_var(),
- ParamKind::Const(ty) => {
- never!("Tuple with const parameter");
- return GenericArgData::Const(self.new_const_var(ty.clone()))
- .intern(Interner);
- }
+ ParamKind::Const(_) => unreachable!("Tuple with const parameter"),
};
arg_tys.push(arg.clone());
- GenericArgData::Ty(arg).intern(Interner)
+ arg.cast(Interner)
})
.build();