Rollup merge of rust-lang#56114 - varkor:nonexhaustive-backticks, r=nikomatsakis

Enclose type in backticks for "non-exhaustive patterns" error

This makes the error style consistent with the convention in error messages.

Author: GuillaumeGomez

src/librustc_mir/hair/pattern/check_match.rs

@@ -234,7 +234,7 @@ impl<'a, 'tcx> MatchVisitor<'a, 'tcx> {
                 if !scrutinee_is_uninhabited {
                     // We know the type is inhabited, so this must be wrong
                     let mut err = create_e0004(self.tcx.sess, scrut.span,
-                                               format!("non-exhaustive patterns: type {} \
+                                               format!("non-exhaustive patterns: type `{}` \
                                                         is non-empty",
                                                        pat_ty));
                     span_help!(&mut err, scrut.span,

src/librustc_typeck/check/autoderef.rs

@@ -59,15 +59,15 @@ impl<'a, 'gcx, 'tcx> Iterator for Autoderef<'a, 'gcx, 'tcx> {
         if self.steps.len() >= *tcx.sess.recursion_limit.get() {
             // We've reached the recursion limit, error gracefully.
             let suggested_limit = *tcx.sess.recursion_limit.get() * 2;
-            let msg = format!("reached the recursion limit while auto-dereferencing {:?}",
+            let msg = format!("reached the recursion limit while auto-dereferencing `{:?}`",
                               self.cur_ty);
             let error_id = (DiagnosticMessageId::ErrorId(55), Some(self.span), msg);
             let fresh = tcx.sess.one_time_diagnostics.borrow_mut().insert(error_id);
             if fresh {
                 struct_span_err!(tcx.sess,
                                  self.span,
                                  E0055,
-                                 "reached the recursion limit while auto-dereferencing {:?}",
+                                 "reached the recursion limit while auto-dereferencing `{:?}`",
                                  self.cur_ty)
                     .span_label(self.span, "deref recursion limit reached")
                     .help(&format!(

src/librustc_typeck/diagnostics.rs

@@ -538,7 +538,7 @@ fn main() {
     let foo = Foo;
     let ref_foo = &&Foo;
 
-    // error, reached the recursion limit while auto-dereferencing &&Foo
+    // error, reached the recursion limit while auto-dereferencing `&&Foo`
     ref_foo.foo();
 }
 ```

src/test/ui/did_you_mean/recursion_limit_deref.stderr

@@ -1,4 +1,4 @@
-error[E0055]: reached the recursion limit while auto-dereferencing I
+error[E0055]: reached the recursion limit while auto-dereferencing `I`
   --> $DIR/recursion_limit_deref.rs:60:22
    |
 LL |     let x: &Bottom = &t; //~ ERROR mismatched types

src/test/ui/error-codes/E0004-2.stderr

@@ -1,4 +1,4 @@
-error[E0004]: non-exhaustive patterns: type std::option::Option<i32> is non-empty
+error[E0004]: non-exhaustive patterns: type `std::option::Option<i32>` is non-empty
   --> $DIR/E0004-2.rs:14:11
    |
 LL |     match x { } //~ ERROR E0004

src/test/ui/error-codes/E0055.stderr

@@ -1,4 +1,4 @@
-error[E0055]: reached the recursion limit while auto-dereferencing Foo
+error[E0055]: reached the recursion limit while auto-dereferencing `Foo`
   --> $DIR/E0055.rs:21:13
    |
 LL |     ref_foo.foo();

src/test/ui/infinite/infinite-autoderef.stderr

@@ -7,15 +7,15 @@ LL |         x = box x;
    |             cyclic type of infinite size
    |             help: try using a conversion method: `box x.to_string()`
 
-error[E0055]: reached the recursion limit while auto-dereferencing Foo
+error[E0055]: reached the recursion limit while auto-dereferencing `Foo`
   --> $DIR/infinite-autoderef.rs:35:5
    |
 LL |     Foo.foo;
    |     ^^^^^^^ deref recursion limit reached
    |
    = help: consider adding a `#![recursion_limit="128"]` attribute to your crate
 
-error[E0055]: reached the recursion limit while auto-dereferencing Foo
+error[E0055]: reached the recursion limit while auto-dereferencing `Foo`
   --> $DIR/infinite-autoderef.rs:35:9
    |
 LL |     Foo.foo;
@@ -29,7 +29,7 @@ error[E0609]: no field `foo` on type `Foo`
 LL |     Foo.foo;
    |         ^^^ unknown field
 
-error[E0055]: reached the recursion limit while auto-dereferencing Foo
+error[E0055]: reached the recursion limit while auto-dereferencing `Foo`
   --> $DIR/infinite-autoderef.rs:36:9
    |
 LL |     Foo.bar();

src/test/ui/issues/issue-3096-1.stderr

@@ -1,4 +1,4 @@
-error[E0004]: non-exhaustive patterns: type () is non-empty
+error[E0004]: non-exhaustive patterns: type `()` is non-empty
   --> $DIR/issue-3096-1.rs:12:11
    |
 LL |     match () { } //~ ERROR non-exhaustive

src/test/ui/issues/issue-3096-2.stderr

@@ -1,4 +1,4 @@
-error[E0004]: non-exhaustive patterns: type *const bottom is non-empty
+error[E0004]: non-exhaustive patterns: type `*const bottom` is non-empty
   --> $DIR/issue-3096-2.rs:15:11
    |
 LL |     match x { } //~ ERROR non-exhaustive patterns

src/test/ui/issues/issue-38940.rs

@@ -42,5 +42,5 @@ fn main() {
     let t = Top::new();
     let x: &Bottom = &t;
     //~^ ERROR mismatched types
-    //~| ERROR reached the recursion limit while auto-dereferencing I
+    //~| ERROR reached the recursion limit while auto-dereferencing `I`
 }

src/test/ui/issues/issue-38940.stderr

@@ -1,4 +1,4 @@
-error[E0055]: reached the recursion limit while auto-dereferencing I
+error[E0055]: reached the recursion limit while auto-dereferencing `I`
   --> $DIR/issue-38940.rs:43:22
    |
 LL |     let x: &Bottom = &t;

src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr

@@ -4,7 +4,7 @@ error[E0004]: non-exhaustive patterns: `Err(_)` not covered
 LL |     let _ = match x {   //~ ERROR non-exhaustive
    |                   ^ pattern `Err(_)` not covered
 
-error[E0004]: non-exhaustive patterns: type &Void is non-empty
+error[E0004]: non-exhaustive patterns: type `&Void` is non-empty
   --> $DIR/uninhabited-matches-feature-gated.rs:20:19
    |
 LL |     let _ = match x {}; //~ ERROR non-exhaustive
@@ -16,7 +16,7 @@ help: ensure that all possible cases are being handled, possibly by adding wildc
 LL |     let _ = match x {}; //~ ERROR non-exhaustive
    |                   ^
 
-error[E0004]: non-exhaustive patterns: type (Void,) is non-empty
+error[E0004]: non-exhaustive patterns: type `(Void,)` is non-empty
   --> $DIR/uninhabited-matches-feature-gated.rs:23:19
    |
 LL |     let _ = match x {}; //~ ERROR non-exhaustive
@@ -28,7 +28,7 @@ help: ensure that all possible cases are being handled, possibly by adding wildc
 LL |     let _ = match x {}; //~ ERROR non-exhaustive
    |                   ^
 
-error[E0004]: non-exhaustive patterns: type [Void; 1] is non-empty
+error[E0004]: non-exhaustive patterns: type `[Void; 1]` is non-empty
   --> $DIR/uninhabited-matches-feature-gated.rs:26:19
    |
 LL |     let _ = match x {}; //~ ERROR non-exhaustive