From d376012a43f91f6dfdd761d786c016f7c343f950 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Thu, 15 Sep 2022 13:43:44 +0000
Subject: [PATCH] Derive TypeFoldable and TypeVisitable for mir::PlaceElement

---
 compiler/rustc_middle/src/mir/mod.rs            |  2 --
 compiler/rustc_middle/src/mir/syntax.rs         |  2 +-
 compiler/rustc_middle/src/mir/type_foldable.rs  | 17 -----------------
 compiler/rustc_middle/src/mir/type_visitable.rs | 12 ------------
 4 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 526bb5d7285..685f11db4e0 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -2551,8 +2551,6 @@ pub(crate) fn variant(
     }
 }
 
-TrivialTypeTraversalAndLiftImpls! { ProjectionKind, }
-
 impl<'tcx> TypeFoldable<'tcx> for UserTypeProjection {
     fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
         Ok(UserTypeProjection {
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index d2bb897b5b6..89b999b55b9 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -872,7 +872,7 @@ pub struct Place<'tcx> {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[derive(TyEncodable, TyDecodable, HashStable)]
+#[derive(TyEncodable, TyDecodable, HashStable, TypeFoldable, TypeVisitable)]
 pub enum ProjectionElem<V, T> {
     Deref,
     Field(Field, T),
diff --git a/compiler/rustc_middle/src/mir/type_foldable.rs b/compiler/rustc_middle/src/mir/type_foldable.rs
index dc72d409473..64dac2e3834 100644
--- a/compiler/rustc_middle/src/mir/type_foldable.rs
+++ b/compiler/rustc_middle/src/mir/type_foldable.rs
@@ -175,23 +175,6 @@ fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Se
     }
 }
 
-impl<'tcx> TypeFoldable<'tcx> for PlaceElem<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
-        use crate::mir::ProjectionElem::*;
-
-        Ok(match self {
-            Deref => Deref,
-            Field(f, ty) => Field(f, ty.try_fold_with(folder)?),
-            Index(v) => Index(v.try_fold_with(folder)?),
-            Downcast(symbol, variantidx) => Downcast(symbol, variantidx),
-            ConstantIndex { offset, min_length, from_end } => {
-                ConstantIndex { offset, min_length, from_end }
-            }
-            Subslice { from, to, from_end } => Subslice { from, to, from_end },
-        })
-    }
-}
-
 impl<'tcx> TypeFoldable<'tcx> for GeneratorSavedLocal {
     fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, _: &mut F) -> Result<Self, F::Error> {
         Ok(self)
diff --git a/compiler/rustc_middle/src/mir/type_visitable.rs b/compiler/rustc_middle/src/mir/type_visitable.rs
index 2963c3273ab..7875b2bb8cf 100644
--- a/compiler/rustc_middle/src/mir/type_visitable.rs
+++ b/compiler/rustc_middle/src/mir/type_visitable.rs
@@ -137,18 +137,6 @@ fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::Br
     }
 }
 
-impl<'tcx> TypeVisitable<'tcx> for PlaceElem<'tcx> {
-    fn visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> ControlFlow<Vs::BreakTy> {
-        use crate::mir::ProjectionElem::*;
-
-        match self {
-            Field(_, ty) => ty.visit_with(visitor),
-            Index(v) => v.visit_with(visitor),
-            _ => ControlFlow::CONTINUE,
-        }
-    }
-}
-
 impl<'tcx> TypeVisitable<'tcx> for GeneratorSavedLocal {
     fn visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> ControlFlow<V::BreakTy> {
         ControlFlow::CONTINUE