X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_middle%2Fsrc%2Fty%2Fmod.rs;h=f83bceca3b53ba27bdcab4885698a9ea0193c60d;hb=c0f80e71661b02270613254dda588ef737df3a31;hp=e68f27cc0fd5d7cb7bb4a3831f7e9d09dbff82a3;hpb=d26e07b91a48047c0acd1e5527f49e57902eb6e7;p=rust.git

diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index e68f27cc0fd..f83bceca3b5 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -28,7 +28,6 @@
 pub use adt::*;
 pub use assoc::*;
 pub use generics::*;
-use hir::OpaqueTyOrigin;
 use rustc_ast as ast;
 use rustc_ast::node_id::NodeMap;
 use rustc_attr as attr;
@@ -39,7 +38,7 @@
 use rustc_data_structures::tagged_ptr::CopyTaggedPtr;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, LifetimeRes, Res};
-use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalDefIdMap};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap};
 use rustc_hir::Node;
 use rustc_index::vec::IndexVec;
 use rustc_macros::HashStable;
@@ -437,7 +436,7 @@ pub struct CrateVariancesMap<'tcx> {
     /// For each item with generics, maps to a vector of the variance
     /// of its generics. If an item has no generics, it will have no
     /// entry.
-    pub variances: FxHashMap<DefId, &'tcx [ty::Variance]>,
+    pub variances: DefIdMap<&'tcx [ty::Variance]>,
 }
 
 // Contains information needed to resolve types and (in the future) look up
@@ -1345,7 +1344,6 @@ pub fn remap_generic_params_to_declaration_params(
         tcx: TyCtxt<'tcx>,
         // typeck errors have subpar spans for opaque types, so delay error reporting until borrowck.
         ignore_errors: bool,
-        origin: OpaqueTyOrigin,
     ) -> Self {
         let OpaqueTypeKey { def_id, substs } = opaque_type_key;
 
@@ -1361,30 +1359,7 @@ pub fn remap_generic_params_to_declaration_params(
         // This zip may have several times the same lifetime in `substs` paired with a different
         // lifetime from `id_substs`. Simply `collect`ing the iterator is the correct behaviour:
         // it will pick the last one, which is the one we introduced in the impl-trait desugaring.
-        let map = substs.iter().zip(id_substs);
-
-        let map: FxHashMap<GenericArg<'tcx>, GenericArg<'tcx>> = match origin {
-            // HACK: The HIR lowering for async fn does not generate
-            // any `+ Captures<'x>` bounds for the `impl Future<...>`, so all async fns with lifetimes
-            // would now fail to compile. We should probably just make hir lowering fill this in properly.
-            OpaqueTyOrigin::AsyncFn(_) => map.collect(),
-            OpaqueTyOrigin::FnReturn(_) | OpaqueTyOrigin::TyAlias => {
-                // Opaque types may only use regions that are bound. So for
-                // ```rust
-                // type Foo<'a, 'b, 'c> = impl Trait<'a> + 'b;
-                // ```
-                // we may not use `'c` in the hidden type.
-                let variances = tcx.variances_of(def_id);
-                debug!(?variances);
-
-                map.filter(|(_, v)| {
-                    let ty::GenericArgKind::Lifetime(lt) = v.unpack() else { return true };
-                    let ty::ReEarlyBound(ebr) = lt.kind() else { bug!() };
-                    variances[ebr.index as usize] == ty::Variance::Invariant
-                })
-                .collect()
-            }
-        };
+        let map = substs.iter().zip(id_substs).collect();
         debug!("map = {:#?}", map);
 
         // Convert the type from the function into a type valid outside
@@ -2382,6 +2357,11 @@ pub fn trait_is_auto(self, trait_def_id: DefId) -> bool {
         self.trait_def(trait_def_id).has_auto_impl
     }
 
+    /// Returns `true` if this is a trait alias.
+    pub fn trait_is_alias(self, trait_def_id: DefId) -> bool {
+        self.def_kind(trait_def_id) == DefKind::TraitAlias
+    }
+
     pub fn trait_is_coinductive(self, trait_def_id: DefId) -> bool {
         self.trait_is_auto(trait_def_id) || self.lang_items().sized_trait() == Some(trait_def_id)
     }
@@ -2639,7 +2619,7 @@ fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
 }
 
 #[derive(Debug, Default, Copy, Clone)]
-pub struct FoundRelationships {
+pub struct InferVarInfo {
     /// This is true if we identified that this Ty (`?T`) is found in a `?T: Foo`
     /// obligation, where:
     ///