Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 20 insertions, 172 deletions

diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 0a903a769..c7d2e4c22 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -2,7 +2,6 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/resolution.html
 
-mod chalk;
 pub mod query;
 pub mod select;
 pub mod solve;
@@ -30,12 +29,8 @@ use std::hash::{Hash, Hasher};
 
 pub use self::select::{EvaluationCache, EvaluationResult, OverflowError, SelectionCache};
 
-pub type CanonicalChalkEnvironmentAndGoal<'tcx> = Canonical<'tcx, ChalkEnvironmentAndGoal<'tcx>>;
-
 pub use self::ObligationCauseCode::*;
 
-pub use self::chalk::{ChalkEnvironmentAndGoal, RustInterner as ChalkRustInterner};
-
 /// Depending on the stage of compilation, we want projection to be
 /// more or less conservative.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, HashStable, Encodable, Decodable)]
@@ -445,6 +440,12 @@ pub enum ObligationCauseCode<'tcx> {
     /// Obligations to prove that a `std::ops::Drop` impl is not stronger than
     /// the ADT it's being implemented for.
     DropImpl,
+
+    /// Requirement for a `const N: Ty` to implement `Ty: ConstParamTy`
+    ConstParam(Ty<'tcx>),
+
+    /// Obligations emitted during the normalization of a weak type alias.
+    TypeAlias(InternedObligationCauseCode<'tcx>, Span, DefId),
 }
 
 /// The 'location' at which we try to perform HIR-based wf checking.
@@ -587,6 +588,10 @@ pub enum SelectionError<'tcx> {
     /// Signaling that an error has already been emitted, to avoid
     /// multiple errors being shown.
     ErrorReporting,
+    /// Computing an opaque type's hidden type caused an error (e.g. a cycle error).
+    /// We can thus not know whether the hidden type implements an auto trait, so
+    /// we should not presume anything about it.
+    OpaqueTypeAutoTraitLeakageUnknown(DefId),
 }
 
 #[derive(Clone, Debug, TypeVisitable, Lift)]
@@ -640,12 +645,6 @@ pub enum ImplSource<'tcx, N> {
     /// ImplSource identifying a particular impl.
     UserDefined(ImplSourceUserDefinedData<'tcx, N>),
 
-    /// ImplSource for auto trait implementations.
-    /// This carries the information and nested obligations with regards
-    /// to an auto implementation for a trait `Trait`. The nested obligations
-    /// ensure the trait implementation holds for all the constituent types.
-    AutoImpl(ImplSourceAutoImplData<N>),
-
     /// Successful resolution to an obligation provided by the caller
     /// for some type parameter. The `Vec<N>` represents the
     /// obligations incurred from normalizing the where-clause (if
@@ -653,84 +652,40 @@ pub enum ImplSource<'tcx, N> {
     Param(Vec<N>, ty::BoundConstness),
 
     /// Virtual calls through an object.
-    Object(ImplSourceObjectData<'tcx, N>),
+    Object(ImplSourceObjectData<N>),
 
     /// Successful resolution for a builtin trait.
-    Builtin(ImplSourceBuiltinData<N>),
+    Builtin(Vec<N>),
 
     /// ImplSource for trait upcasting coercion
-    TraitUpcasting(ImplSourceTraitUpcastingData<'tcx, N>),
-
-    /// ImplSource automatically generated for a closure. The `DefId` is the ID
-    /// of the closure expression. This is an `ImplSource::UserDefined` in spirit, but the
-    /// impl is generated by the compiler and does not appear in the source.
-    Closure(ImplSourceClosureData<'tcx, N>),
-
-    /// Same as above, but for a function pointer type with the given signature.
-    FnPointer(ImplSourceFnPointerData<'tcx, N>),
-
-    /// ImplSource automatically generated for a generator.
-    Generator(ImplSourceGeneratorData<'tcx, N>),
-
-    /// ImplSource automatically generated for a generator backing an async future.
-    Future(ImplSourceFutureData<'tcx, N>),
-
-    /// ImplSource for a trait alias.
-    TraitAlias(ImplSourceTraitAliasData<'tcx, N>),
-
-    /// ImplSource for a `const Drop` implementation.
-    ConstDestruct(ImplSourceConstDestructData<N>),
+    TraitUpcasting(ImplSourceTraitUpcastingData<N>),
 }
 
 impl<'tcx, N> ImplSource<'tcx, N> {
     pub fn nested_obligations(self) -> Vec<N> {
         match self {
             ImplSource::UserDefined(i) => i.nested,
-            ImplSource::Param(n, _) => n,
-            ImplSource::Builtin(i) => i.nested,
-            ImplSource::AutoImpl(d) => d.nested,
-            ImplSource::Closure(c) => c.nested,
-            ImplSource::Generator(c) => c.nested,
-            ImplSource::Future(c) => c.nested,
+            ImplSource::Param(n, _) | ImplSource::Builtin(n) => n,
             ImplSource::Object(d) => d.nested,
-            ImplSource::FnPointer(d) => d.nested,
-            ImplSource::TraitAlias(d) => d.nested,
             ImplSource::TraitUpcasting(d) => d.nested,
-            ImplSource::ConstDestruct(i) => i.nested,
         }
     }
 
     pub fn borrow_nested_obligations(&self) -> &[N] {
         match self {
             ImplSource::UserDefined(i) => &i.nested,
-            ImplSource::Param(n, _) => n,
-            ImplSource::Builtin(i) => &i.nested,
-            ImplSource::AutoImpl(d) => &d.nested,
-            ImplSource::Closure(c) => &c.nested,
-            ImplSource::Generator(c) => &c.nested,
-            ImplSource::Future(c) => &c.nested,
+            ImplSource::Param(n, _) | ImplSource::Builtin(n) => &n,
             ImplSource::Object(d) => &d.nested,
-            ImplSource::FnPointer(d) => &d.nested,
-            ImplSource::TraitAlias(d) => &d.nested,
             ImplSource::TraitUpcasting(d) => &d.nested,
-            ImplSource::ConstDestruct(i) => &i.nested,
         }
     }
 
     pub fn borrow_nested_obligations_mut(&mut self) -> &mut [N] {
         match self {
             ImplSource::UserDefined(i) => &mut i.nested,
-            ImplSource::Param(n, _) => n,
-            ImplSource::Builtin(i) => &mut i.nested,
-            ImplSource::AutoImpl(d) => &mut d.nested,
-            ImplSource::Closure(c) => &mut c.nested,
-            ImplSource::Generator(c) => &mut c.nested,
-            ImplSource::Future(c) => &mut c.nested,
+            ImplSource::Param(n, _) | ImplSource::Builtin(n) => n,
             ImplSource::Object(d) => &mut d.nested,
-            ImplSource::FnPointer(d) => &mut d.nested,
-            ImplSource::TraitAlias(d) => &mut d.nested,
             ImplSource::TraitUpcasting(d) => &mut d.nested,
-            ImplSource::ConstDestruct(i) => &mut i.nested,
         }
     }
 
@@ -745,54 +700,17 @@ impl<'tcx, N> ImplSource<'tcx, N> {
                 nested: i.nested.into_iter().map(f).collect(),
             }),
             ImplSource::Param(n, ct) => ImplSource::Param(n.into_iter().map(f).collect(), ct),
-            ImplSource::Builtin(i) => ImplSource::Builtin(ImplSourceBuiltinData {
-                nested: i.nested.into_iter().map(f).collect(),
-            }),
+            ImplSource::Builtin(n) => ImplSource::Builtin(n.into_iter().map(f).collect()),
             ImplSource::Object(o) => ImplSource::Object(ImplSourceObjectData {
-                upcast_trait_ref: o.upcast_trait_ref,
                 vtable_base: o.vtable_base,
                 nested: o.nested.into_iter().map(f).collect(),
             }),
-            ImplSource::AutoImpl(d) => ImplSource::AutoImpl(ImplSourceAutoImplData {
-                trait_def_id: d.trait_def_id,
-                nested: d.nested.into_iter().map(f).collect(),
-            }),
-            ImplSource::Closure(c) => ImplSource::Closure(ImplSourceClosureData {
-                closure_def_id: c.closure_def_id,
-                substs: c.substs,
-                nested: c.nested.into_iter().map(f).collect(),
-            }),
-            ImplSource::Generator(c) => ImplSource::Generator(ImplSourceGeneratorData {
-                generator_def_id: c.generator_def_id,
-                substs: c.substs,
-                nested: c.nested.into_iter().map(f).collect(),
-            }),
-            ImplSource::Future(c) => ImplSource::Future(ImplSourceFutureData {
-                generator_def_id: c.generator_def_id,
-                substs: c.substs,
-                nested: c.nested.into_iter().map(f).collect(),
-            }),
-            ImplSource::FnPointer(p) => ImplSource::FnPointer(ImplSourceFnPointerData {
-                fn_ty: p.fn_ty,
-                nested: p.nested.into_iter().map(f).collect(),
-            }),
-            ImplSource::TraitAlias(d) => ImplSource::TraitAlias(ImplSourceTraitAliasData {
-                alias_def_id: d.alias_def_id,
-                substs: d.substs,
-                nested: d.nested.into_iter().map(f).collect(),
-            }),
             ImplSource::TraitUpcasting(d) => {
                 ImplSource::TraitUpcasting(ImplSourceTraitUpcastingData {
-                    upcast_trait_ref: d.upcast_trait_ref,
                     vtable_vptr_slot: d.vtable_vptr_slot,
                     nested: d.nested.into_iter().map(f).collect(),
                 })
             }
-            ImplSource::ConstDestruct(i) => {
-                ImplSource::ConstDestruct(ImplSourceConstDestructData {
-                    nested: i.nested.into_iter().map(f).collect(),
-                })
-            }
         }
     }
 }
@@ -817,47 +735,7 @@ pub struct ImplSourceUserDefinedData<'tcx, N> {
 
 #[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
 #[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceGeneratorData<'tcx, N> {
-    pub generator_def_id: DefId,
-    pub substs: SubstsRef<'tcx>,
-    /// Nested obligations. This can be non-empty if the generator
-    /// signature contains associated types.
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceFutureData<'tcx, N> {
-    pub generator_def_id: DefId,
-    pub substs: SubstsRef<'tcx>,
-    /// Nested obligations. This can be non-empty if the generator
-    /// signature contains associated types.
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceClosureData<'tcx, N> {
-    pub closure_def_id: DefId,
-    pub substs: SubstsRef<'tcx>,
-    /// Nested obligations. This can be non-empty if the closure
-    /// signature contains associated types.
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceAutoImplData<N> {
-    pub trait_def_id: DefId,
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceTraitUpcastingData<'tcx, N> {
-    /// `Foo` upcast to the obligation trait. This will be some supertrait of `Foo`.
-    pub upcast_trait_ref: ty::PolyTraitRef<'tcx>,
-
+pub struct ImplSourceTraitUpcastingData<N> {
     /// The vtable is formed by concatenating together the method lists of
     /// the base object trait and all supertraits, pointers to supertrait vtable will
     /// be provided when necessary; this is the position of `upcast_trait_ref`'s vtable
@@ -867,18 +745,9 @@ pub struct ImplSourceTraitUpcastingData<'tcx, N> {
     pub nested: Vec<N>,
 }
 
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceBuiltinData<N> {
-    pub nested: Vec<N>,
-}
-
 #[derive(PartialEq, Eq, Clone, TyEncodable, TyDecodable, HashStable, Lift)]
 #[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceObjectData<'tcx, N> {
-    /// `Foo` upcast to the obligation trait. This will be some supertrait of `Foo`.
-    pub upcast_trait_ref: ty::PolyTraitRef<'tcx>,
-
+pub struct ImplSourceObjectData<N> {
     /// The vtable is formed by concatenating together the method lists of
     /// the base object trait and all supertraits, pointers to supertrait vtable will
     /// be provided when necessary; this is the start of `upcast_trait_ref`'s methods
@@ -888,27 +757,6 @@ pub struct ImplSourceObjectData<'tcx, N> {
     pub nested: Vec<N>,
 }
 
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceFnPointerData<'tcx, N> {
-    pub fn_ty: Ty<'tcx>,
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceConstDestructData<N> {
-    pub nested: Vec<N>,
-}
-
-#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct ImplSourceTraitAliasData<'tcx, N> {
-    pub alias_def_id: DefId,
-    pub substs: SubstsRef<'tcx>,
-    pub nested: Vec<N>,
-}
-
 #[derive(Clone, Debug, PartialEq, Eq, Hash, HashStable, PartialOrd, Ord)]
 pub enum ObjectSafetyViolation {
     /// `Self: Sized` declared on the trait.
@@ -1109,7 +957,7 @@ pub enum CodegenObligationError {
     FulfillmentError,
 }
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, TypeFoldable, TypeVisitable)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)]
 pub enum DefiningAnchor {
     /// `DefId` of the item.
     Bind(LocalDefId),