4 files changed, 21 insertions, 4 deletions
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index 8ea535599c9..2050c5f9608 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -1,7 +1,6 @@
 //! The main parser interface.
 
 // tidy-alphabetical-start
-#![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![feature(assert_matches)]
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 9ed7124a11c..d6cc98d505c 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -2206,7 +2206,7 @@ impl<'a> Parser<'a> {
 
             if self.look_ahead(1, |t| *t == token::Bang) && self.look_ahead(2, |t| t.is_ident()) {
                 return IsMacroRulesItem::Yes { has_bang: true };
-            } else if self.look_ahead(1, |t| (t.is_ident())) {
+            } else if self.look_ahead(1, |t| t.is_ident()) {
                 // macro_rules foo
                 self.dcx().emit_err(errors::MacroRulesMissingBang {
                     span: macro_rules_span,
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index bc939b8f5a7..90491e53249 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -1297,8 +1297,10 @@ impl<'a> Parser<'a> {
         let kind = if pat {
             let guar = self
                 .dcx()
-                .struct_span_err(blk_span, "`inline_const_pat` has been removed")
-                .with_help("use a named `const`-item or an `if`-guard instead")
+                .struct_span_err(blk_span, "const blocks cannot be used as patterns")
+                .with_help(
+                    "use a named `const`-item or an `if`-guard (`x if x == const { ... }`) instead",
+                )
                 .emit();
             ExprKind::Err(guar)
         } else {
diff --git a/compiler/rustc_parse/src/validate_attr.rs b/compiler/rustc_parse/src/validate_attr.rs
index 67b68e77d2b..bb5c1e0e653 100644
--- a/compiler/rustc_parse/src/validate_attr.rs
+++ b/compiler/rustc_parse/src/validate_attr.rs
@@ -271,6 +271,10 @@ pub fn check_builtin_meta_item(
         if matches!(
             name,
             sym::inline
+                | sym::export_stable
+                | sym::ffi_const
+                | sym::ffi_pure
+                | sym::rustc_std_internal_symbol
                 | sym::may_dangle
                 | sym::rustc_as_ptr
                 | sym::rustc_pub_transparent
@@ -279,6 +283,18 @@ pub fn check_builtin_meta_item(
                 | sym::rustc_confusables
                 | sym::rustc_skip_during_method_dispatch
                 | sym::rustc_pass_by_value
+                | sym::rustc_deny_explicit_impl
+                | sym::rustc_do_not_implement_via_object
+                | sym::rustc_coinductive
+                | sym::const_trait
+                | sym::rustc_specialization_trait
+                | sym::rustc_unsafe_specialization_marker
+                | sym::rustc_allow_incoherent_impl
+                | sym::rustc_coherence_is_core
+                | sym::marker
+                | sym::fundamental
+                | sym::rustc_paren_sugar
+                | sym::type_const
                 | sym::repr
                 | sym::align
                 | sym::deprecated