From 9c29e0b818a157023025da233f0c411dfebb5080 Mon Sep 17 00:00:00 2001
From: bohan <bohan-zhang@foxmail.com>
Date: Thu, 8 Aug 2024 20:30:20 +0800
Subject: [PATCH] rm `declared_features` field in resolver

---
 compiler/rustc_resolve/src/lib.rs    | 5 -----
 compiler/rustc_resolve/src/macros.rs | 3 ++-
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 023e428dc1ba7..89ac839651fb1 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -1129,9 +1129,6 @@ pub struct Resolver<'a, 'tcx> {
     /// Also includes of list of each fields visibility
     struct_constructors: LocalDefIdMap<(Res, ty::Visibility<DefId>, Vec<ty::Visibility<DefId>>)>,
 
-    /// Features declared for this crate.
-    declared_features: FxHashSet<Symbol>,
-
     lint_buffer: LintBuffer,
 
     next_node_id: NodeId,
@@ -1402,7 +1399,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
         let registered_tools = tcx.registered_tools(());
 
-        let features = tcx.features();
         let pub_vis = ty::Visibility::<DefId>::Public;
         let edition = tcx.sess.edition();
 
@@ -1506,7 +1502,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             multi_segment_macro_resolutions: Default::default(),
             builtin_attrs: Default::default(),
             containers_deriving_copy: Default::default(),
-            declared_features: features.declared_features.clone(),
             lint_buffer: LintBuffer::default(),
             next_node_id: CRATE_NODE_ID,
             node_id_to_def_id,
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index a6301a367a4b3..da7278175e93a 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -1001,7 +1001,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 let feature = stability.feature;
 
                 let is_allowed = |feature| {
-                    self.declared_features.contains(&feature) || span.allows_unstable(feature)
+                    self.tcx.features().declared_features.contains(&feature)
+                        || span.allows_unstable(feature)
                 };
                 let allowed_by_implication = implied_by.is_some_and(|feature| is_allowed(feature));
                 if !is_allowed(feature) && !allowed_by_implication {