diff --git a/src/libsyntax/attr/builtin.rs b/src/libsyntax/attr/builtin.rs
index d0a31b330ab39..7886824cd32cf 100644
--- a/src/libsyntax/attr/builtin.rs
+++ b/src/libsyntax/attr/builtin.rs
@@ -535,6 +535,10 @@ pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
     super::first_attr_value_str_by_name(attrs, sym::crate_name)
 }
 
+pub fn is_accessible(_sess: &ParseSess, _path: &ast::Path) -> bool {
+    true
+}
+
 /// Tests if a cfg-pattern matches the cfg set
 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
     eval_condition(cfg, sess, &mut |cfg| {
@@ -546,6 +550,15 @@ pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Feat
             return error(cfg.path.span, "`cfg` predicate key must be an identifier");
         }
         match &cfg.kind {
+            MetaItemKind::List(ref mis) if cfg.name_or_empty() == sym::accessible => {
+                if mis.len() != 1 {
+                    span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
+                    return false;
+                }
+                dbg!(&cfg);
+                dbg!(&cfg.path);
+                unreachable!();
+            }
             MetaItemKind::List(..) => {
                 error(cfg.span, "unexpected parentheses after `cfg` predicate key")
             }
diff --git a/src/libsyntax/feature_gate/active.rs b/src/libsyntax/feature_gate/active.rs
index d59d0f0e28e9b..46d53378cfd2a 100644
--- a/src/libsyntax/feature_gate/active.rs
+++ b/src/libsyntax/feature_gate/active.rs
@@ -529,6 +529,9 @@ declare_features! (
     /// Allows using the `#[register_attr]` attribute.
     (active, register_tool, "1.41.0", Some(66079), None),
 
+    /// Allows the use of `#[cfg(accessible(..))]`.
+    (active, cfg_accessible, "1.41.0", Some(64797), None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------
diff --git a/src/libsyntax/feature_gate/builtin_attrs.rs b/src/libsyntax/feature_gate/builtin_attrs.rs
index 608cc2a09cbee..74adcdfaf8ab5 100644
--- a/src/libsyntax/feature_gate/builtin_attrs.rs
+++ b/src/libsyntax/feature_gate/builtin_attrs.rs
@@ -27,6 +27,7 @@ macro_rules! cfg_fn {
 /// `cfg(...)`'s that are feature gated.
 const GATED_CFGS: &[(Symbol, Symbol, GateFn)] = &[
     // (name in cfg, feature, function to check if the feature is enabled)
+    (sym::accessible, sym::cfg_accessible, cfg_fn!(cfg_accessible)),
     (sym::target_thread_local, sym::cfg_target_thread_local, cfg_fn!(cfg_target_thread_local)),
     (sym::target_has_atomic, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
     (sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index c41f413970ff5..9cb50c2f37eeb 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -119,6 +119,7 @@ symbols! {
         abi_vectorcall,
         abi_x86_interrupt,
         aborts,
+        accessible,
         advanced_slice_patterns,
         adx_target_feature,
         alias,
@@ -172,6 +173,7 @@ symbols! {
         C,
         cdylib,
         cfg,
+        cfg_accessible,
         cfg_attr,
         cfg_attr_multi,
         cfg_doctest,
diff --git a/src/test/ui/feature-gates/feature-gate-cfg_accessible.rs b/src/test/ui/feature-gates/feature-gate-cfg_accessible.rs
new file mode 100644
index 0000000000000..1a1fc71f21b2f
--- /dev/null
+++ b/src/test/ui/feature-gates/feature-gate-cfg_accessible.rs
@@ -0,0 +1,2 @@
+#[cfg(accessible(::std::mem::ManuallyDrop))] //~^ ERROR: currently unstable
+fn main() {}