resolve: Fix variant namespacing

Author: petrochenkov

src/librustc_resolve/build_reduced_graph.rs

@@ -510,9 +510,9 @@ impl<'a, 'b:'a, 'tcx:'b> GraphBuilder<'a, 'b, 'tcx> {
             self.structs.insert(variant_def_id, Vec::new());
         }
 
+        // Variants are always treated as importable to allow them to be glob used.
+        // All variants are defined in both type and value namespaces as future-proofing.
         let child = self.add_child(name, parent, ForbidDuplicateTypesAndValues, variant.span);
-        // variants are always treated as importable to allow them to be glob
-        // used
         child.define_value(Def::Variant(item_id, self.ast_map.local_def_id(variant.node.data.id())),
                            variant.span,
                            DefModifiers::PUBLIC | DefModifiers::IMPORTABLE | variant_modifiers);
@@ -618,15 +618,14 @@ impl<'a, 'b:'a, 'tcx:'b> GraphBuilder<'a, 'b, 'tcx> {
             Def::Variant(_, variant_id) => {
                 debug!("(building reduced graph for external crate) building variant {}",
                        final_ident);
-                // variants are always treated as importable to allow them to be
-                // glob used
+                // Variants are always treated as importable to allow them to be glob used.
+                // All variants are defined in both type and value namespaces as future-proofing.
                 let modifiers = DefModifiers::PUBLIC | DefModifiers::IMPORTABLE;
+                child_name_bindings.define_type(def, DUMMY_SP, modifiers);
+                child_name_bindings.define_value(def, DUMMY_SP, modifiers);
                 if self.session.cstore.variant_kind(variant_id) == Some(VariantKind::Struct) {
-                    child_name_bindings.define_type(def, DUMMY_SP, modifiers);
                     // Not adding fields for variants as they are not accessed with a self receiver
                     self.structs.insert(variant_id, Vec::new());
-                } else {
-                    child_name_bindings.define_value(def, DUMMY_SP, modifiers);
                 }
             }
             Def::Fn(..) |

src/test/auxiliary/variant-namespacing.rs

@@ -0,0 +1,15 @@
+// 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.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub enum XE {
+    XStruct { a: u8 },
+    XTuple(u8),
+    XUnit,
+}

src/test/compile-fail/empty-struct-braces-pat-1.rs

@@ -39,6 +39,6 @@ fn main() {
         XEmpty1 => () // Not an error, `XEmpty1` is interpreted as a new binding
     }
     match xe3 {
-        XE::XEmpty3 => () //~ ERROR no associated item named `XEmpty3` found for type
+        XE::XEmpty3 => () //~ ERROR `XE::XEmpty3` does not name a tuple variant or a tuple struct
     }
 }

src/test/compile-fail/empty-struct-braces-pat-3.rs

@@ -36,6 +36,6 @@ fn main() {
         E::Empty3(..) => () //~ ERROR `E::Empty3` does not name a tuple variant or a tuple struct
     }
     match xe3 {
-        XE::XEmpty3(..) => () //~ ERROR no associated item named `XEmpty3` found for type
+        XE::XEmpty3(..) => () //~ ERROR `XE::XEmpty3` does not name a tuple variant or a tuple
     }
 }

src/test/compile-fail/variant-namespacing.rs

@@ -0,0 +1,49 @@
+// 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.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// aux-build:variant-namespacing.rs
+
+extern crate variant_namespacing;
+pub use variant_namespacing::XE::*;
+//~^ ERROR import `XStruct` conflicts with type in this module
+//~| ERROR import `XStruct` conflicts with value in this module
+//~| ERROR import `XTuple` conflicts with type in this module
+//~| ERROR import `XTuple` conflicts with value in this module
+//~| ERROR import `XUnit` conflicts with type in this module
+//~| ERROR import `XUnit` conflicts with value in this module
+pub use E::*;
+//~^ ERROR import `Struct` conflicts with type in this module
+//~| ERROR import `Struct` conflicts with value in this module
+//~| ERROR import `Tuple` conflicts with type in this module
+//~| ERROR import `Tuple` conflicts with value in this module
+//~| ERROR import `Unit` conflicts with type in this module
+//~| ERROR import `Unit` conflicts with value in this module
+
+enum E {
+    Struct { a: u8 },
+    Tuple(u8),
+    Unit,
+}
+
+type Struct = u8;
+type Tuple = u8;
+type Unit = u8;
+type XStruct = u8;
+type XTuple = u8;
+type XUnit = u8;
+
+const Struct: u8 = 0;
+const Tuple: u8 = 0;
+const Unit: u8 = 0;
+const XStruct: u8 = 0;
+const XTuple: u8 = 0;
+const XUnit: u8 = 0;
+
+fn main() {}

src/test/run-pass/empty-struct-braces.rs

@@ -95,8 +95,7 @@ fn xcrate() {
     let e2: XEmpty2 = XEmpty2 {};
     let e2: XEmpty2 = XEmpty2;
     let e3: XE = XE::XEmpty3 {};
-    // FIXME: Commented out tests are waiting for PR 30882 (fixes for variant namespaces)
-    // let e4: XE = XE::XEmpty4 {};
+    let e4: XE = XE::XEmpty4 {};
     let e4: XE = XE::XEmpty4;
 
     match e1 {
@@ -109,10 +108,10 @@ fn xcrate() {
         XE::XEmpty3 {} => {}
         _ => {}
     }
-    // match e4 {
-    //     XE::XEmpty4 {} => {}
-    //     _ => {}
-    // }
+    match e4 {
+        XE::XEmpty4 {} => {}
+        _ => {}
+    }
 
     match e1 {
         XEmpty1 { .. } => {}
@@ -124,18 +123,18 @@ fn xcrate() {
         XE::XEmpty3 { .. } => {}
         _ => {}
     }
-    // match e4 {
-    //     XE::XEmpty4 { .. } => {}
-    //     _ => {}
-    // }
+    match e4 {
+        XE::XEmpty4 { .. } => {}
+        _ => {}
+    }
 
     match e2 {
         XEmpty2 => {}
     }
-    // match e4 {
-    //     XE::XEmpty4 => {}
-    //     _ => {}
-    // }
+    match e4 {
+        XE::XEmpty4 => {}
+        _ => {}
+    }
 
     let e11: XEmpty1 = XEmpty1 { ..e1 };
     let e22: XEmpty2 = XEmpty2 { ..e2 };