use structured suggestion for pattern-named-the-same-as-variant warning

Author: zackmdavis

src/librustc_mir/hair/pattern/check_match.rs

@@ -23,7 +23,7 @@ use rustc::session::Session;
 use rustc::ty::{self, Ty, TyCtxt};
 use rustc::ty::subst::Substs;
 use rustc::lint;
-use rustc_errors::DiagnosticBuilder;
+use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc::util::common::ErrorReported;
 
 use rustc::hir::def::*;
@@ -328,10 +328,12 @@ fn check_for_bindings_named_the_same_as_variants(cx: &MatchVisitor, pat: &Pat) {
                         "pattern binding `{}` is named the same as one \
                          of the variants of the type `{}`",
                         name.node, ty_path);
-                    help!(err,
-                        "if you meant to match on a variant, \
-                        consider making the path in the pattern qualified: `{}::{}`",
-                        ty_path, name.node);
+                    err.span_suggestion_with_applicability(
+                        p.span,
+                        "to match on the variant, qualify the path",
+                        format!("{}::{}", ty_path, name.node),
+                        Applicability::MachineApplicable
+                    );
                     err.emit();
                 }
             }

src/test/ui/issue-19100.fixed

@@ -0,0 +1,40 @@
+// 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.
+
+// run-pass
+// run-rustfix
+
+#![allow(non_snake_case)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+#[derive(Copy, Clone)]
+enum Foo {
+    Bar,
+    Baz
+}
+
+impl Foo {
+    fn foo(&self) {
+        match self {
+            &
+Foo::Bar if true
+//~^ WARN pattern binding `Bar` is named the same as one of the variants of the type `Foo`
+=> println!("bar"),
+            &
+Foo::Baz if false
+//~^ WARN pattern binding `Baz` is named the same as one of the variants of the type `Foo`
+=> println!("baz"),
+_ => ()
+        }
+    }
+}
+
+fn main() {}

src/test/ui/issue-19100.rs

@@ -9,6 +9,7 @@
 // except according to those terms.
 
 // run-pass
+// run-rustfix
 
 #![allow(non_snake_case)]
 #![allow(dead_code)]

src/test/ui/issue-19100.stderr

@@ -1,16 +1,12 @@
 warning[E0170]: pattern binding `Bar` is named the same as one of the variants of the type `Foo`
-  --> $DIR/issue-19100.rs:27:1
+  --> $DIR/issue-19100.rs:28:1
    |
 LL | Bar if true
-   | ^^^
-   |
-   = help: if you meant to match on a variant, consider making the path in the pattern qualified: `Foo::Bar`
+   | ^^^ help: to match on the variant, qualify the path: `Foo::Bar`
 
 warning[E0170]: pattern binding `Baz` is named the same as one of the variants of the type `Foo`
-  --> $DIR/issue-19100.rs:31:1
+  --> $DIR/issue-19100.rs:32:1
    |
 LL | Baz if false
-   | ^^^
-   |
-   = help: if you meant to match on a variant, consider making the path in the pattern qualified: `Foo::Baz`
+   | ^^^ help: to match on the variant, qualify the path: `Foo::Baz`
 

src/test/ui/issue-30302.stderr

@@ -2,9 +2,7 @@ warning[E0170]: pattern binding `Nil` is named the same as one of the variants o
   --> $DIR/issue-30302.rs:23:9
    |
 LL |         Nil => true,
-   |         ^^^
-   |
-   = help: if you meant to match on a variant, consider making the path in the pattern qualified: `Stack::Nil`
+   |         ^^^ help: to match on the variant, qualify the path: `Stack::Nil`
 
 error: unreachable pattern
   --> $DIR/issue-30302.rs:25:9