Unsupport `#[derive(Trait)]` sugar for `#[derive_Trait]` legacy plugin attributes

1 files changed, 0 insertions, 16 deletions

diff --git a/src/librustc_plugin/registry.rs b/src/librustc_plugin/registry.rs
index 6c10ac7ea5c..2fb28a8a66f 100644
--- a/src/librustc_plugin/registry.rs
+++ b/src/librustc_plugin/registry.rs
@@ -60,8 +60,6 @@ pub struct Registry<'a> {
 
     #[doc(hidden)]
     pub attributes: Vec<(String, AttributeType)>,
-
-    whitelisted_custom_derives: Vec<ast::Name>,
 }
 
 impl<'a> Registry<'a> {
@@ -77,7 +75,6 @@ impl<'a> Registry<'a> {
             lint_groups: FxHashMap::default(),
             llvm_passes: vec![],
             attributes: vec![],
-            whitelisted_custom_derives: Vec::new(),
         }
     }
 
@@ -130,19 +127,6 @@ impl<'a> Registry<'a> {
         }));
     }
 
-    /// This can be used in place of `register_syntax_extension` to register legacy custom derives
-    /// (i.e. attribute syntax extensions whose name begins with `derive_`). Legacy custom
-    /// derives defined by this function do not trigger deprecation warnings when used.
-    pub fn register_custom_derive(&mut self, name: ast::Name, extension: SyntaxExtension) {
-        assert!(name.as_str().starts_with("derive_"));
-        self.whitelisted_custom_derives.push(name);
-        self.register_syntax_extension(name, extension);
-    }
-
-    pub fn take_whitelisted_custom_derives(&mut self) -> Vec<ast::Name> {
-        ::std::mem::replace(&mut self.whitelisted_custom_derives, Vec::new())
-    }
-
     /// Register a macro of the usual kind.
     ///
     /// This is a convenience wrapper for `register_syntax_extension`.