Fix handling of struct variants in a couple of places

Fixes #17405.
Fixes #17518.
Fixes #17800.

src/librustc/diagnostics.rs

@@ -38,7 +38,6 @@ register_diagnostics!(
     E0017,
     E0019,
     E0020,
-    E0021,
     E0022,
     E0023,
     E0024,
@@ -62,7 +61,6 @@ register_diagnostics!(
     E0045,
     E0046,
     E0047,
-    E0048,
     E0049,
     E0050,
     E0051,
@@ -117,8 +115,6 @@ register_diagnostics!(
     E0109,
     E0110,
     E0113,
-    E0114,
-    E0115,
     E0116,
     E0117,
     E0118,
@@ -152,5 +148,7 @@ register_diagnostics!(
     E0158,
     E0159,
     E0161,
-    E0162
+    E0162,
+    E0163,
+    E0164
 )

src/librustc/middle/typeck/check/_match.rs

@@ -382,26 +382,43 @@ pub fn check_struct_like_enum_variant_pat(pcx: &pat_ctxt,
 
     // Find the variant that was specified.
     match tcx.def_map.borrow().find(&pat_id) {
-        Some(&def::DefVariant(found_enum_id, variant_id, _))
+        Some(&def::DefVariant(found_enum_id, variant_id, true))
                 if found_enum_id == enum_id => {
             // Get the struct fields from this struct-like enum variant.
-            let class_fields = ty::lookup_struct_fields(tcx, variant_id);
-
-            check_struct_pat_fields(pcx, span, fields, class_fields,
+            let struct_fields = ty::lookup_struct_fields(tcx, variant_id);
+            check_struct_pat_fields(pcx, span, fields, struct_fields,
                                     variant_id, substitutions, etc);
+            fcx.write_ty(pat_id, expected);
+        }
+        Some(&def::DefVariant(_, _, false)) => {
+            let name = pprust::path_to_string(path);
+            span_err!(tcx.sess, span, E0163,
+                "`{}` does not name a struct variant", name);
+            fcx.write_error(pat_id);
+        }
+        Some(&def::DefVariant(_, _, true)) => {
+            let name = pprust::path_to_string(path);
+            span_err!(tcx.sess, span, E0164,
+                "`{}` does not name a variant of the type being matched against", name);
+            fcx.write_error(pat_id);
         }
         Some(&def::DefStruct(..)) |
-        Some(&def::DefVariant(..)) |
         Some(&def::DefTy(..)) => {
             let name = pprust::path_to_string(path);
             span_err!(tcx.sess, span, E0028,
-                "mismatched types: expected `{}`, found `{}`",
-                fcx.infcx().ty_to_string(expected), name);
+                "`{}` does not name a variant", name);
+            fcx.write_error(pat_id);
         }
         _ => {
             tcx.sess.span_bug(span, "resolve didn't write in variant");
         }
     }
+
+    if ty::type_is_error(fcx.node_ty(pat_id)) {
+        for field in fields.iter() {
+            check_pat(pcx, &*field.pat, ty::mk_err());
+        }
+    }
 }
 
 // Pattern checking is top-down rather than bottom-up so that bindings get

src/librustc/middle/typeck/check/mod.rs

@@ -4330,7 +4330,7 @@ fn check_expr_with_unifier(fcx: &FnCtxt,
         // Resolve the path.
         let def = tcx.def_map.borrow().find(&id).map(|i| *i);
         let struct_id = match def {
-            Some(def::DefVariant(enum_id, variant_id, _)) => {
+            Some(def::DefVariant(enum_id, variant_id, true)) => {
                 check_struct_enum_variant(fcx, id, expr.span, enum_id,
                                           variant_id, fields.as_slice());
                 enum_id

src/test/compile-fail/issue-15896.rs

@@ -18,7 +18,7 @@ fn main() {
     let e = B(REB(()), Tau { t: 3 });
     let u = match e {
         B(
-          Tau{t: x},    //~ ERROR mismatched types
+          Tau{t: x}, //~ ERROR `Tau` does not name a variant
           _) => x,
     };
 }

src/test/compile-fail/issue-17405.rs

@@ -0,0 +1,19 @@
+// Copyright 2014 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.
+
+enum Foo {
+    Bar(int)
+}
+
+fn main() {
+    match Bar(1i) {
+        Foo { i } => () //~ ERROR `Foo` does not name a variant
+    }
+}

src/test/compile-fail/issue-17518.rs

@@ -0,0 +1,17 @@
+// Copyright 2014 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.
+
+enum SomeEnum {
+    E
+}
+
+fn main() {
+    E { name: "foobar" }; //~ ERROR `E` does not name a structure
+}

src/test/compile-fail/issue-17800.rs

@@ -0,0 +1,21 @@
+// Copyright 2014 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.
+
+enum MyOption<T> {
+    MySome(T),
+    MyNone,
+}
+
+fn main() {
+    match MySome(42i) {
+        MySome { x: 42i } => (), //~ ERROR `MySome` does not name a struct variant
+        _ => (),
+    }
+}