From 167b70692ba2a97521237d36b487fbfccd3fb72b Mon Sep 17 00:00:00 2001
From: Jack Huey <31162821+jackh726@users.noreply.github.com>
Date: Thu, 6 Apr 2023 21:26:38 -0400
Subject: [PATCH] Remove expect_anon and expect_anon_placeholder in favor of
 var

---
 compiler/rustc_middle/src/infer/canonical.rs   | 10 ++++------
 compiler/rustc_middle/src/ty/sty.rs            | 18 ------------------
 .../src/solve/eval_ctxt/canonical.rs           |  2 +-
 compiler/rustc_traits/src/chalk/lowering.rs    | 16 +++++++---------
 4 files changed, 12 insertions(+), 34 deletions(-)

diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index d3f71e75d99..6bbf9690bf6 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -149,17 +149,15 @@ pub fn is_region(&self) -> bool {
         }
     }
 
-    pub fn expect_anon_placeholder(self) -> u32 {
+    pub fn expect_placeholder_index(self) -> usize {
         match self.kind {
             CanonicalVarKind::Ty(_)
             | CanonicalVarKind::Region(_)
             | CanonicalVarKind::Const(_, _) => bug!("expected placeholder: {self:?}"),
 
-            CanonicalVarKind::PlaceholderRegion(placeholder) => {
-                placeholder.bound.kind.expect_anon()
-            }
-            CanonicalVarKind::PlaceholderTy(placeholder) => placeholder.bound.kind.expect_anon(),
-            CanonicalVarKind::PlaceholderConst(placeholder, _) => placeholder.bound.as_u32(),
+            CanonicalVarKind::PlaceholderRegion(placeholder) => placeholder.bound.var.as_usize(),
+            CanonicalVarKind::PlaceholderTy(placeholder) => placeholder.bound.var.as_usize(),
+            CanonicalVarKind::PlaceholderConst(placeholder, _) => placeholder.bound.as_usize(),
         }
     }
 }
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index f6d79e94a51..76194f350f5 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -107,15 +107,6 @@ pub fn get_id(&self) -> Option<DefId> {
             _ => None,
         }
     }
-
-    pub fn expect_anon(&self) -> u32 {
-        match *self {
-            BoundRegionKind::BrNamed(_, _) | BoundRegionKind::BrEnv => {
-                bug!("expected anon region: {self:?}")
-            }
-            BoundRegionKind::BrAnon(idx, _) => idx,
-        }
-    }
 }
 
 pub trait Article {
@@ -1537,15 +1528,6 @@ pub enum BoundTyKind {
     Param(DefId, Symbol),
 }
 
-impl BoundTyKind {
-    pub fn expect_anon(self) -> u32 {
-        match self {
-            BoundTyKind::Anon(i) => i,
-            _ => bug!(),
-        }
-    }
-}
-
 impl From<BoundVar> for BoundTy {
     fn from(var: BoundVar) -> Self {
         BoundTy { var, kind: BoundTyKind::Anon(var.as_u32()) }
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
index ee90488730a..714b6dfb717 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
@@ -188,7 +188,7 @@ fn compute_query_response_substitution(
                 } else {
                     // For placeholders which were already part of the input, we simply map this
                     // universal bound variable back the placeholder of the input.
-                    original_values[info.expect_anon_placeholder() as usize]
+                    original_values[info.expect_placeholder_index()]
                 }
             },
         ));
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index f7caf50c56a..c59e496eb0a 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -1168,13 +1168,12 @@ fn interner(&self) -> TyCtxt<'tcx> {
 
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
         match *t.kind() {
-            ty::Placeholder(ty::PlaceholderType {
-                universe: ty::UniverseIndex::ROOT,
-                bound: ty::BoundTy { kind: name, .. },
-            }) => match self.params.get(&name.expect_anon()) {
-                Some(&ty::ParamTy { index, name }) => self.tcx.mk_ty_param(index, name),
-                None => t,
-            },
+            ty::Placeholder(ty::PlaceholderType { universe: ty::UniverseIndex::ROOT, bound }) => {
+                match self.params.get(&bound.var.as_u32()) {
+                    Some(&ty::ParamTy { index, name }) => self.tcx.mk_ty_param(index, name),
+                    None => t,
+                }
+            }
 
             _ => t.super_fold_with(self),
         }
@@ -1202,8 +1201,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for PlaceholdersCollector {
     fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
         match t.kind() {
             ty::Placeholder(p) if p.universe == self.universe_index => {
-                self.next_ty_placeholder =
-                    self.next_ty_placeholder.max(p.bound.kind.expect_anon() as usize + 1);
+                self.next_ty_placeholder = self.next_ty_placeholder.max(p.bound.var.as_usize() + 1);
             }
 
             _ => (),