From 8a4cbcf2207cc6ee489e1c3fea9e7d8dfeb396d9 Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Sun, 31 Jul 2022 16:13:25 +0200
Subject: [PATCH] Derive HashStable for HIR Expr and Ty.

---
 compiler/rustc_hir/src/hir.rs                   |  4 ++--
 compiler/rustc_hir/src/stable_hash_impls.rs     | 17 +----------------
 .../rustc_query_system/src/ich/impls_hir.rs     | 14 --------------
 3 files changed, 3 insertions(+), 32 deletions(-)

diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 617433a9803..79b2ef9f93e 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1626,7 +1626,7 @@ pub struct AnonConst {
 }
 
 /// An expression.
-#[derive(Debug)]
+#[derive(Debug, HashStable_Generic)]
 pub struct Expr<'hir> {
     pub hir_id: HirId,
     pub kind: ExprKind<'hir>,
@@ -2380,7 +2380,7 @@ impl TypeBinding<'_> {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, HashStable_Generic)]
 pub struct Ty<'hir> {
     pub hir_id: HirId,
     pub kind: TyKind<'hir>,
diff --git a/compiler/rustc_hir/src/stable_hash_impls.rs b/compiler/rustc_hir/src/stable_hash_impls.rs
index 8ccd59e8e37..5b9c42686c3 100644
--- a/compiler/rustc_hir/src/stable_hash_impls.rs
+++ b/compiler/rustc_hir/src/stable_hash_impls.rs
@@ -1,8 +1,7 @@
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
 
 use crate::hir::{
-    AttributeMap, BodyId, Crate, Expr, ForeignItemId, ImplItemId, ItemId, OwnerNodes, TraitItemId,
-    Ty,
+    AttributeMap, BodyId, Crate, ForeignItemId, ImplItemId, ItemId, OwnerNodes, TraitItemId,
 };
 use crate::hir_id::{HirId, ItemLocalId};
 use rustc_span::def_id::DefPathHash;
@@ -14,8 +13,6 @@ pub trait HashStableContext:
     rustc_ast::HashStableContext + rustc_target::HashStableContext
 {
     fn hash_body_id(&mut self, _: BodyId, hasher: &mut StableHasher);
-    fn hash_hir_expr(&mut self, _: &Expr<'_>, hasher: &mut StableHasher);
-    fn hash_hir_ty(&mut self, _: &Ty<'_>, hasher: &mut StableHasher);
 }
 
 impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for HirId {
@@ -96,18 +93,6 @@ impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for BodyId {
 // want to pick up on a reference changing its target, so we hash the NodeIds
 // in "DefPath Mode".
 
-impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for Expr<'_> {
-    fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_hir_expr(self, hasher)
-    }
-}
-
-impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for Ty<'_> {
-    fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
-        hcx.hash_hir_ty(self, hasher)
-    }
-}
-
 impl<'tcx, HirCtx: crate::HashStableContext> HashStable<HirCtx> for OwnerNodes<'tcx> {
     fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
         // We ignore the `nodes` and `bodies` fields since these refer to information included in
diff --git a/compiler/rustc_query_system/src/ich/impls_hir.rs b/compiler/rustc_query_system/src/ich/impls_hir.rs
index 6a43487aea8..b717db76578 100644
--- a/compiler/rustc_query_system/src/ich/impls_hir.rs
+++ b/compiler/rustc_query_system/src/ich/impls_hir.rs
@@ -19,18 +19,4 @@ impl<'ctx> rustc_hir::HashStableContext for StableHashingContext<'ctx> {
             }
         }
     }
-
-    fn hash_hir_expr(&mut self, expr: &hir::Expr<'_>, hasher: &mut StableHasher) {
-        let hir::Expr { hir_id, ref span, ref kind } = *expr;
-        hir_id.hash_stable(self, hasher);
-        span.hash_stable(self, hasher);
-        kind.hash_stable(self, hasher);
-    }
-
-    fn hash_hir_ty(&mut self, ty: &hir::Ty<'_>, hasher: &mut StableHasher) {
-        let hir::Ty { hir_id, ref kind, ref span } = *ty;
-        hir_id.hash_stable(self, hasher);
-        kind.hash_stable(self, hasher);
-        span.hash_stable(self, hasher);
-    }
 }