Replace #[plugin_registrar] with exporting __rustc_plugin_registrar

3 files changed, 5 insertions, 70 deletions

diff --git a/compiler/rustc_plugin_impl/src/build.rs b/compiler/rustc_plugin_impl/src/build.rs
deleted file mode 100644
index b95c4a72019..00000000000
--- a/compiler/rustc_plugin_impl/src/build.rs
+++ /dev/null
@@ -1,57 +0,0 @@
-//! Used by `rustc` when compiling a plugin crate.
-
-use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
-use rustc_hir::itemlikevisit::ItemLikeVisitor;
-use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::TyCtxt;
-use rustc_span::symbol::sym;
-use rustc_span::Span;
-
-struct RegistrarFinder<'tcx> {
-    tcx: TyCtxt<'tcx>,
-    registrars: Vec<(LocalDefId, Span)>,
-}
-
-impl<'v, 'tcx> ItemLikeVisitor<'v> for RegistrarFinder<'tcx> {
-    fn visit_item(&mut self, item: &hir::Item<'_>) {
-        if let hir::ItemKind::Fn(..) = item.kind {
-            let attrs = self.tcx.hir().attrs(item.hir_id());
-            if self.tcx.sess.contains_name(attrs, sym::plugin_registrar) {
-                self.registrars.push((item.def_id, item.span));
-            }
-        }
-    }
-
-    fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {}
-
-    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {}
-
-    fn visit_foreign_item(&mut self, _foreign_item: &hir::ForeignItem<'_>) {}
-}
-
-/// Finds the function marked with `#[plugin_registrar]`, if any.
-fn plugin_registrar_fn(tcx: TyCtxt<'_>, (): ()) -> Option<LocalDefId> {
-    let mut finder = RegistrarFinder { tcx, registrars: Vec::new() };
-    tcx.hir().krate().visit_all_item_likes(&mut finder);
-
-    let (def_id, span) = finder.registrars.pop()?;
-
-    if !finder.registrars.is_empty() {
-        let diagnostic = tcx.sess.diagnostic();
-        let mut e = diagnostic.struct_err("multiple plugin registration functions found");
-        e.span_note(span, "one is here");
-        for &(_, span) in &finder.registrars {
-            e.span_note(span, "one is here");
-        }
-        e.emit();
-        diagnostic.abort_if_errors();
-        unreachable!();
-    }
-
-    Some(def_id)
-}
-
-pub fn provide(providers: &mut Providers) {
-    *providers = Providers { plugin_registrar_fn, ..*providers };
-}
diff --git a/compiler/rustc_plugin_impl/src/lib.rs b/compiler/rustc_plugin_impl/src/lib.rs
index 5bf4d300e9e..a1e13a1abb6 100644
--- a/compiler/rustc_plugin_impl/src/lib.rs
+++ b/compiler/rustc_plugin_impl/src/lib.rs
@@ -12,7 +12,6 @@
 
 use rustc_lint::LintStore;
 
-pub mod build;
 pub mod load;
 
 /// Structure used to register plugins.
diff --git a/compiler/rustc_plugin_impl/src/load.rs b/compiler/rustc_plugin_impl/src/load.rs
index 687f7db221f..5da02e3a489 100644
--- a/compiler/rustc_plugin_impl/src/load.rs
+++ b/compiler/rustc_plugin_impl/src/load.rs
@@ -55,20 +55,13 @@ fn load_plugin(
     metadata_loader: &dyn MetadataLoader,
     ident: Ident,
 ) {
-    let (lib, disambiguator) =
-        locator::find_plugin_registrar(sess, metadata_loader, ident.span, ident.name);
-    let symbol = sess.generate_plugin_registrar_symbol(disambiguator);
-    let fun = dylink_registrar(sess, ident.span, lib, symbol);
+    let lib = locator::find_plugin_registrar(sess, metadata_loader, ident.span, ident.name);
+    let fun = dylink_registrar(sess, ident.span, lib);
     plugins.push(fun);
 }
 
 // Dynamically link a registrar function into the compiler process.
-fn dylink_registrar(
-    sess: &Session,
-    span: Span,
-    path: PathBuf,
-    symbol: String,
-) -> PluginRegistrarFn {
+fn dylink_registrar(sess: &Session, span: Span, path: PathBuf) -> PluginRegistrarFn {
     use rustc_metadata::dynamic_lib::DynamicLibrary;
 
     // Make sure the path contains a / or the linker will search for it.
@@ -83,7 +76,7 @@ fn dylink_registrar(
     };
 
     unsafe {
-        let registrar = match lib.symbol(&symbol) {
+        let registrar = match lib.symbol("__rustc_plugin_registrar") {
             Ok(registrar) => mem::transmute::<*mut u8, PluginRegistrarFn>(registrar),
             // again fatal if we can't register macros
             Err(err) => sess.span_fatal(span, &err),
@@ -91,7 +84,7 @@ fn dylink_registrar(
 
         // Intentionally leak the dynamic library. We can't ever unload it
         // since the library can make things that will live arbitrarily long
-        // (e.g., an @-box cycle or a thread).
+        // (e.g., an Rc cycle or a thread).
         mem::forget(lib);
 
         registrar