From f525b173edd08cf68f025a5b2db38b665887771d Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 10 Mar 2025 02:31:16 +0000
Subject: [PATCH] Remove AdtFlags::IS_ANONYMOUS and Copy/Clone condition for
 anonymous ADT

---
 compiler/rustc_middle/src/ty/adt.rs                     | 8 --------
 compiler/rustc_middle/src/ty/mod.rs                     | 2 +-
 compiler/rustc_trait_selection/src/traits/select/mod.rs | 9 ---------
 3 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index 3585f28b4a550..c1dc6a894cae5 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -53,8 +53,6 @@ bitflags::bitflags! {
         const IS_VARIANT_LIST_NON_EXHAUSTIVE = 1 << 8;
         /// Indicates whether the type is `UnsafeCell`.
         const IS_UNSAFE_CELL              = 1 << 9;
-        /// Indicates whether the type is anonymous.
-        const IS_ANONYMOUS                = 1 << 10;
     }
 }
 rustc_data_structures::external_bitflags_debug! { AdtFlags }
@@ -402,12 +400,6 @@ impl<'tcx> AdtDef<'tcx> {
         self.flags().contains(AdtFlags::IS_MANUALLY_DROP)
     }
 
-    /// Returns `true` if this is an anonymous adt
-    #[inline]
-    pub fn is_anonymous(self) -> bool {
-        self.flags().contains(AdtFlags::IS_ANONYMOUS)
-    }
-
     /// Returns `true` if this type has a destructor.
     pub fn has_dtor(self, tcx: TyCtxt<'tcx>) -> bool {
         self.destructor(tcx).is_some()
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index c5509c0a6087e..97cfe5946af15 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1151,7 +1151,7 @@ pub struct VariantDef {
     /// `DefId` that identifies the variant's constructor.
     /// If this variant is a struct variant, then this is `None`.
     pub ctor: Option<(CtorKind, DefId)>,
-    /// Variant or struct name, maybe empty for anonymous adt (struct or union).
+    /// Variant or struct name.
     pub name: Symbol,
     /// Discriminant of this variant.
     pub discr: VariantDiscr,
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 0a54b8468fe3c..e1adabbeaa662 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2231,15 +2231,6 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 }
             }
 
-            // `Copy` and `Clone` are automatically implemented for an anonymous adt
-            // if all of its fields are `Copy` and `Clone`
-            ty::Adt(adt, args) if adt.is_anonymous() => {
-                // (*) binder moved here
-                Where(obligation.predicate.rebind(
-                    adt.non_enum_variant().fields.iter().map(|f| f.ty(self.tcx(), args)).collect(),
-                ))
-            }
-
             ty::Adt(..) | ty::Alias(..) | ty::Param(..) | ty::Placeholder(..) => {
                 // Fallback to whatever user-defined impls exist in this case.
                 None