Use the proper term when using non-existing variant

When using a non-existing variant, function or associated item, refer to
the proper term, instead of defaulting to "associated item" in
diagnostics.

Author: estebank

src/librustc/ty/sty.rs

@@ -1219,6 +1219,15 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    pub fn is_enum(&self) -> bool {
+        match self.sty {
+            TyAdt(adt_def, _) => {
+                adt_def.is_enum()
+            }
+            _ => false,
+        }
+    }
+
     pub fn is_closure(&self) -> bool {
         match self.sty {
             TyClosure(..) => true,
@@ -1233,6 +1242,13 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
         }
     }
 
+    pub fn is_fresh_ty(&self) -> bool {
+        match self.sty {
+            TyInfer(FreshTy(_)) => true,
+            _ => false,
+        }
+    }
+
     pub fn is_fresh(&self) -> bool {
         match self.sty {
             TyInfer(FreshTy(_)) => true,

src/librustc_typeck/check/method/suggest.rs

@@ -164,12 +164,14 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         };
 
         match error {
-            MethodError::NoMatch(NoMatchData { static_candidates: static_sources,
-                                               unsatisfied_predicates,
-                                               out_of_scope_traits,
-                                               lev_candidate,
-                                               mode,
-                                               .. }) => {
+            MethodError::NoMatch(NoMatchData {
+                static_candidates: static_sources,
+                unsatisfied_predicates,
+                out_of_scope_traits,
+                lev_candidate,
+                mode,
+                ..
+            }) => {
                 let tcx = self.tcx;
 
                 let actual = self.resolve_type_vars_if_possible(&rcvr_ty);
@@ -179,18 +181,19 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                                       current scope",
                                      if mode == Mode::MethodCall {
                                          "method"
+                                     } else if actual.is_enum() {
+                                         "variant"
                                      } else {
-                                         match item_name.as_str().chars().next() {
-                                             Some(name) => {
-                                                 if name.is_lowercase() {
-                                                     "function or associated item"
-                                                 } else {
-                                                     "associated item"
-                                                 }
-                                             },
-                                             None => {
-                                                 ""
-                                             },
+                                         let fresh_ty = actual.is_fresh_ty();
+                                         match (item_name.as_str().chars().next(), fresh_ty) {
+                                             (Some(name), false) if name.is_lowercase() => {
+                                                 "function or associated item"
+                                             }
+                                             (Some(_), false) => "associated item",
+                                             (Some(_), true) | (None, false) => {
+                                                 "variant or associated item"
+                                             }
+                                             (None, true) => "variant",
                                          }
                                      },
                                      item_name,

src/test/compile-fail/bogus-tag.rs

@@ -15,6 +15,6 @@ fn main() {
     let red: color = color::rgb(255, 0, 0);
     match red {
       color::rgb(r, g, b) => { println!("rgb"); }
-      color::hsl(h, s, l) => { println!("hsl"); }  //~ ERROR no function
+      color::hsl(h, s, l) => { println!("hsl"); }  //~ ERROR no variant
     }
 }

src/test/compile-fail/empty-struct-braces-expr.rs

@@ -29,6 +29,6 @@ fn main() {
 
     let xe1 = XEmpty1; //~ ERROR expected value, found struct `XEmpty1`
     let xe1 = XEmpty1(); //~ ERROR expected function, found struct `XEmpty1`
-    let xe3 = XE::Empty3; //~ ERROR no associated item named `Empty3` found for type
-    let xe3 = XE::Empty3(); //~ ERROR no associated item named `Empty3` found for type
+    let xe3 = XE::Empty3; //~ ERROR no variant named `Empty3` found for type
+    let xe3 = XE::Empty3(); //~ ERROR no variant named `Empty3` found for type
 }

src/test/compile-fail/issue-22933-2.rs

@@ -12,7 +12,7 @@ enum Delicious {
     Pie      = 0x1,
     Apple    = 0x2,
     ApplePie = Delicious::Apple as isize | Delicious::PIE as isize,
-    //~^ ERROR no associated item named `PIE` found for type `Delicious`
+    //~^ ERROR no variant named `PIE` found for type `Delicious`
 }
 
 fn main() {}

src/test/compile-fail/issue-23173.rs

@@ -13,5 +13,5 @@ enum Token { LeftParen, RightParen, Plus, Minus, /* etc */ }
 fn use_token(token: &Token) { unimplemented!() }
 
 fn main() {
-    use_token(&Token::Homura); //~ ERROR no associated item named
+    use_token(&Token::Homura); //~ ERROR no variant named `Homura`
 }

src/test/compile-fail/issue-23217.rs

@@ -10,7 +10,7 @@
 
 pub enum SomeEnum {
     B = SomeEnum::A,
-    //~^ ERROR no associated item named `A` found for type `SomeEnum`
+    //~^ ERROR no variant named `A` found for type `SomeEnum`
 }
 
 fn main() {}

src/test/compile-fail/issue-28971.rs

@@ -16,7 +16,8 @@ enum Foo {
 fn main(){
     foo(|| {
         match Foo::Bar(1) {
-            Foo::Baz(..) => (), //~ ERROR no associated
+            Foo::Baz(..) => (),
+            //~^ ERROR no variant named `Baz` found for type `Foo`
             _ => (),
         }
     });