Auto merge of #60794 - Centril:rollup-vlguvns, r=Centril

Rollup of 5 pull requests

Successful merges:

 - #60176 (Explain error when yielding a reference to a local variable)
 - #60201 (coretest: Downgrade deny to warn)
 - #60562 (Add #[doc(hidden)] attribute on compiler generated module.)
 - #60710 (Use `delay_span_bug` for error cases when checking `AnonConst` parent)
 - #60770 (add impl_trait_in_bindings to INCOMPLETE_FEATURES)

Failed merges:

r? @ghost

1 files changed, 6 insertions, 1 deletions

diff --git a/src/libsyntax_ext/proc_macro_decls.rs b/src/libsyntax_ext/proc_macro_decls.rs
index 5ced1400acb..1eab739cf64 100644
--- a/src/libsyntax_ext/proc_macro_decls.rs
+++ b/src/libsyntax_ext/proc_macro_decls.rs
@@ -328,6 +328,7 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
 
 // Creates a new module which looks like:
 //
+//      #[doc(hidden)]
 //      mod $gensym {
 //          extern crate proc_macro;
 //
@@ -361,6 +362,10 @@ fn mk_decls(
     });
     let span = DUMMY_SP.apply_mark(mark);
 
+    let hidden = cx.meta_list_item_word(span, Symbol::intern("hidden"));
+    let doc = cx.meta_list(span, Symbol::intern("doc"), vec![hidden]);
+    let doc_hidden = cx.attribute(span, doc);
+
     let proc_macro = Ident::from_str("proc_macro");
     let krate = cx.item(span,
                         proc_macro,
@@ -425,7 +430,7 @@ fn mk_decls(
         span,
         span,
         ast::Ident::with_empty_ctxt(Symbol::gensym("decls")),
-        vec![],
+        vec![doc_hidden],
         vec![krate, decls_static],
     ).map(|mut i| {
         i.vis = respan(span, ast::VisibilityKind::Public);