libsyntax: forbid visibility modifiers for enum variants

fixes rust-lang#28433

Author: matklad

src/libsyntax/parse/parser.rs

@@ -5210,13 +5210,10 @@ impl<'a> Parser<'a> {
             let variant_attrs = self.parse_outer_attributes();
             let vlo = self.span.lo;
 
-            let vis = try!(self.parse_visibility());
-
-            let ident;
             let kind;
             let mut args = Vec::new();
             let mut disr_expr = None;
-            ident = try!(self.parse_ident());
+            let ident = try!(self.parse_ident());
             if try!(self.eat(&token::OpenDelim(token::Brace)) ){
                 // Parse a struct variant.
                 all_nullary = false;
@@ -5258,7 +5255,7 @@ impl<'a> Parser<'a> {
                 kind: kind,
                 id: ast::DUMMY_NODE_ID,
                 disr_expr: disr_expr,
-                vis: vis,
+                vis: Inherited,
             };
             variants.push(P(spanned(vlo, self.last_span.hi, vr)));
 

src/test/compile-fail/issue-3993-2.rs renamed to src/test/compile-fail/issue-28433.rs

@@ -1,4 +1,4 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,16 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use zoo::bird::{duck, goose};
-
-mod zoo {
-    pub enum bird {
-        pub duck, //~ ERROR: unnecessary `pub` visibility
-        goose
-    }
+enum bird {
+    pub duck, //~ ERROR: expected identifier, found keyword `pub`
+    goose
 }
 
 
 fn main() {
-    let y = goose;
+    let y = bird::goose;
 }

src/test/compile-fail/useless-priv.rs renamed to src/test/compile-fail/useless-pub.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 struct A { pub i: isize }
-pub enum C { pub Variant }      //~ ERROR: unnecessary `pub`
 
 pub trait E {
     fn foo(&self);