1 files changed, 50 insertions, 0 deletions
diff --git a/third_party/rust/inherent/src/visibility.rs b/third_party/rust/inherent/src/visibility.rs
new file mode 100644
index 0000000000..72213fda62
--- /dev/null
+++ b/third_party/rust/inherent/src/visibility.rs
@@ -0,0 +1,50 @@
+use proc_macro2::TokenStream;
+use quote::ToTokens;
+use syn::ext::IdentExt;
+use syn::parse::{Parse, ParseStream, Result};
+use syn::{Ident, Path, Token, VisPublic, VisRestricted};
+
+pub struct Visibility {
+    variant: syn::Visibility,
+}
+
+impl Parse for Visibility {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let lookahead = input.lookahead1();
+
+        let variant = if input.is_empty() {
+            syn::Visibility::Inherited
+        } else if lookahead.peek(Token![pub]) {
+            syn::Visibility::Public(VisPublic {
+                pub_token: input.parse()?,
+            })
+        } else if lookahead.peek(Token![crate])
+            || lookahead.peek(Token![self])
+            || lookahead.peek(Token![super])
+        {
+            syn::Visibility::Restricted(VisRestricted {
+                pub_token: Default::default(),
+                paren_token: Default::default(),
+                in_token: None,
+                path: Box::new(Path::from(input.call(Ident::parse_any)?)),
+            })
+        } else if lookahead.peek(Token![in]) {
+            syn::Visibility::Restricted(VisRestricted {
+                pub_token: Default::default(),
+                paren_token: Default::default(),
+                in_token: Some(input.parse()?),
+                path: Box::new(input.call(Path::parse_mod_style)?),
+            })
+        } else {
+            return Err(lookahead.error());
+        };
+
+        Ok(Visibility { variant })
+    }
+}
+
+impl ToTokens for Visibility {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        self.variant.to_tokens(tokens);
+    }
+}