bjoernager/rust
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fast_reject: remove StripReferences

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This commit is contained in:
lcnr 2022-01-25 12:50:00 +01:00
parent 165142e993
commit 0efc6c02cb
7 changed files with 20 additions and 68 deletions
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20
compiler/rustc_middle/src/ty/fast_reject.rs
View file

@ -54,12 +54,6 @@ pub enum SimplifyParams {
No,
}
#[derive(PartialEq, Eq, Debug, Clone, Copy)]
pub enum StripReferences {
Yes,
No,
}
/// Tries to simplify a type by only returning the outermost injective¹ layer, if one exists.
///
/// The idea is to get something simple that we can use to quickly decide if two types could unify,
@ -73,8 +67,6 @@ pub enum StripReferences {
/// When using `SimplifyParams::Yes`, we still return a simplified type for params and projections²,
/// the reasoning for this can be seen at the places doing this.
///
/// For diagnostics we strip references with `StripReferences::Yes`. This is currently the best
/// way to skip some unhelpful suggestions.
///
/// ¹ meaning that if two outermost layers are different, then the whole types are also different.
/// ² FIXME(@lcnr): this seems like it can actually end up being unsound with the way it's used during
@ -87,7 +79,6 @@ pub fn simplify_type(
tcx: TyCtxt<'_>,
ty: Ty<'_>,
can_simplify_params: SimplifyParams,
strip_references: StripReferences,
) -> Option<SimplifiedType> {
match *ty.kind() {
ty::Bool => Some(BoolSimplifiedType),
@ -106,16 +97,7 @@ pub fn simplify_type(
}
_ => Some(MarkerTraitObjectSimplifiedType),
},
ty::Ref(_, ty, mutbl) => {
if strip_references == StripReferences::Yes {
// For diagnostics, when recommending similar impls we want to
// recommend impls even when there is a reference mismatch,
// so we treat &T and T equivalently in that case.
simplify_type(tcx, ty, can_simplify_params, strip_references)
} else {
Some(RefSimplifiedType(mutbl))
}
}
ty::Ref(_, _, mutbl) => Some(RefSimplifiedType(mutbl)),
ty::FnDef(def_id, _) | ty::Closure(def_id, _) => Some(ClosureSimplifiedType(def_id)),
ty::Generator(def_id, _, _) => Some(GeneratorSimplifiedType(def_id)),
ty::GeneratorWitness(ref tys) => {

12
compiler/rustc_middle/src/ty/trait_def.rs
View file

@ -1,5 +1,5 @@
use crate::traits::specialization_graph;
use crate::ty::fast_reject::{self, SimplifiedType, SimplifyParams, StripReferences};
use crate::ty::fast_reject::{self, SimplifiedType, SimplifyParams};
use crate::ty::fold::TypeFoldable;
use crate::ty::{Ident, Ty, TyCtxt};
use rustc_hir as hir;
@ -150,9 +150,7 @@ impl<'tcx> TyCtxt<'tcx> {
self_ty: Ty<'tcx>,
) -> impl Iterator<Item = DefId> + 'tcx {
let impls = self.trait_impls_of(def_id);
if let Some(simp) =
fast_reject::simplify_type(self, self_ty, SimplifyParams::No, StripReferences::No)
{
if let Some(simp) = fast_reject::simplify_type(self, self_ty, SimplifyParams::No) {
if let Some(impls) = impls.non_blanket_impls.get(&simp) {
return impls.iter().copied();
}
@ -189,9 +187,7 @@ impl<'tcx> TyCtxt<'tcx> {
// whose outer level is not a parameter or projection. Especially for things like
// `T: Clone` this is incredibly useful as we would otherwise look at all the impls
// of `Clone` for `Option<T>`, `Vec<T>`, `ConcreteType` and so on.
if let Some(simp) =
fast_reject::simplify_type(self, self_ty, SimplifyParams::Yes, StripReferences::No)
{
if let Some(simp) = fast_reject::simplify_type(self, self_ty, SimplifyParams::Yes) {
if let Some(impls) = impls.non_blanket_impls.get(&simp) {
for &impl_def_id in impls {
if let result @ Some(_) = f(impl_def_id) {
@ -251,7 +247,7 @@ pub(super) fn trait_impls_of_provider(tcx: TyCtxt<'_>, trait_id: DefId) -> Trait
}
if let Some(simplified_self_ty) =
fast_reject::simplify_type(tcx, impl_self_ty, SimplifyParams::No, StripReferences::No)
fast_reject::simplify_type(tcx, impl_self_ty, SimplifyParams::No)
{
impls.non_blanket_impls.entry(simplified_self_ty).or_default().push(impl_def_id);
} else {