make trait two ways turn usizes private

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -12,7 +12,7 @@ use rustc_middle::mir::interpret::AllocId;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::{CrateNum, DefId};
 use rustc_span::Span;
-use stable_mir::ty::IndexToVal;
+use stable_mir::ty::IndexedVal;
 use stable_mir::CompilerError;
 use std::fmt::Debug;
 use std::hash::Hash;
@@ -23,7 +23,7 @@ impl<'tcx> Index<stable_mir::DefId> for Tables<'tcx> {
 
     #[inline(always)]
     fn index(&self, index: stable_mir::DefId) -> &Self::Output {
-        &self.def_ids.get_index_and_assert(index.0, index)
+        &self.def_ids[index]
     }
 }
 
@@ -32,7 +32,7 @@ impl<'tcx> Index<stable_mir::ty::Span> for Tables<'tcx> {
 
     #[inline(always)]
     fn index(&self, index: stable_mir::ty::Span) -> &Self::Output {
-        &self.spans.get_index_and_assert(index.0, index)
+        &self.spans[index]
     }
 }
 
@@ -98,15 +98,15 @@ impl<'tcx> Tables<'tcx> {
     }
 
     fn create_def_id(&mut self, did: DefId) -> stable_mir::DefId {
-        self.def_ids.entry(did)
+        self.def_ids.create_or_fetch(did)
     }
 
     fn create_alloc_id(&mut self, aid: AllocId) -> stable_mir::AllocId {
-        self.alloc_ids.entry(aid)
+        self.alloc_ids.create_or_fetch(aid)
     }
 
     pub(crate) fn create_span(&mut self, span: Span) -> stable_mir::ty::Span {
-        self.spans.entry(span)
+        self.spans.create_or_fetch(span)
     }
 }
 
@@ -192,19 +192,22 @@ pub struct IndexMap<K, V> {
     index_map: fx::FxIndexMap<K, V>,
 }
 
-impl<K: PartialEq + Hash + Eq, V: Copy + Debug + PartialEq + IndexToVal> IndexMap<K, V> {
-    /// Because we are using values as indexes, this first get's the
-    /// key using index of the value provided, then asserts that value
-    /// we got from IndexMap is equal to one we provided.
-    pub fn get_index_and_assert(&self, index: usize, value: V) -> &K {
-        let (k, v) = self.index_map.get_index(index).unwrap();
-        assert_eq!(*v, value, "Provided value doesn't match with indexed value");
-        k
-    }
-
-    pub fn entry(&mut self, key: K) -> V {
+impl<K: PartialEq + Hash + Eq, V: Copy + Debug + PartialEq + IndexedVal> IndexMap<K, V> {
+    pub fn create_or_fetch(&mut self, key: K) -> V {
         let len = self.index_map.len();
         let v = self.index_map.entry(key).or_insert(V::to_val(len));
         *v
     }
 }
+
+impl<K: PartialEq + Hash + Eq, V: Copy + Debug + PartialEq + IndexedVal> Index<V>
+    for IndexMap<K, V>
+{
+    type Output = K;
+
+    fn index(&self, index: V) -> &Self::Output {
+        let (k, v) = self.index_map.get_index(index.to_index()).unwrap();
+        assert_eq!(*v, index, "Provided value doesn't match with indexed value");
+        k
+    }
+}

compiler/stable_mir/src/lib.rs

@@ -22,7 +22,7 @@ use std::fmt;
 use std::fmt::Debug;
 
 use self::ty::{
-    GenericPredicates, Generics, ImplDef, ImplTrait, IndexToVal, Span, TraitDecl, TraitDef, Ty,
+    GenericPredicates, Generics, ImplDef, ImplTrait, IndexedVal, Span, TraitDecl, TraitDef, Ty,
     TyKind,
 };
 
@@ -42,7 +42,7 @@ pub type CrateNum = usize;
 
 /// A unique identification number for each item accessible for the current compilation unit.
 #[derive(Clone, Copy, PartialEq, Eq)]
-pub struct DefId(pub usize);
+pub struct DefId(usize);
 
 impl Debug for DefId {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -53,26 +53,27 @@ impl Debug for DefId {
     }
 }
 
-impl IndexToVal for DefId {
-    fn to_val(index: usize) -> Self
-    where
-        Self: std::marker::Sized,
-    {
+impl IndexedVal for DefId {
+    fn to_val(index: usize) -> Self {
         DefId(index)
     }
+
+    fn to_index(&self) -> usize {
+        self.0
+    }
 }
 
 /// A unique identification number for each provenance
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
-pub struct AllocId(pub usize);
+pub struct AllocId(usize);
 
-impl IndexToVal for AllocId {
-    fn to_val(index: usize) -> Self
-    where
-        Self: std::marker::Sized,
-    {
+impl IndexedVal for AllocId {
+    fn to_val(index: usize) -> Self {
         AllocId(index)
     }
+    fn to_index(&self) -> usize {
+        self.0
+    }
 }
 
 /// A list of crate items.

compiler/stable_mir/src/ty.rs

@@ -75,7 +75,7 @@ pub struct Placeholder<T> {
 }
 
 #[derive(Clone, Copy, PartialEq, Eq)]
-pub struct Span(pub usize);
+pub struct Span(usize);
 
 impl Debug for Span {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
@@ -86,13 +86,13 @@ impl Debug for Span {
     }
 }
 
-impl IndexToVal for Span {
-    fn to_val(index: usize) -> Self
-    where
-        Self: std::marker::Sized,
-    {
+impl IndexedVal for Span {
+    fn to_val(index: usize) -> Self {
         Span(index)
     }
+    fn to_index(&self) -> usize {
+        self.0
+    }
 }
 
 #[derive(Clone, Debug)]
@@ -575,8 +575,8 @@ pub enum ImplPolarity {
     Reservation,
 }
 
-pub trait IndexToVal {
-    fn to_val(index: usize) -> Self
-    where
-        Self: std::marker::Sized;
+pub trait IndexedVal {
+    fn to_val(index: usize) -> Self;
+
+    fn to_index(&self) -> usize;
 }