parser: tweak unmatched wording

Author: Centril

src/librustc_parse/parser/item.rs

@@ -119,17 +119,18 @@ impl<'a> Parser<'a> {
         }
         let vs = pprust::vis_to_string(&vis);
         let vs = vs.trim_end();
-        self.struct_span_err(vis.span, &format!("unmatched visibility `{}`", vs))
-            .span_label(vis.span, "the unmatched visibility")
+        self.struct_span_err(vis.span, &format!("visibility `{}` not followed by an item", vs))
+            .span_label(vis.span, "the visibility")
             .help(&format!("you likely meant to define an item, e.g., `{} fn foo() {{}}`", vs))
             .emit();
     }
 
     /// Error in-case a `default` was parsed but no item followed.
     fn error_on_unmatched_defaultness(&self, def: Defaultness) {
-        if let Defaultness::Default(span) = def {
-            self.struct_span_err(span, "unmatched `default`")
-                .span_label(span, "the unmatched `default`")
+        if let Defaultness::Default(sp) = def {
+            self.struct_span_err(sp, "`default` not followed by an item")
+                .span_label(sp, "the `default` qualifier")
+                .note("only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`")
                 .emit();
         }
     }

src/test/ui/parser/default-unmatched-assoc.rs

@@ -3,14 +3,14 @@ fn main() {}
 trait Foo {
     default!(); //~ ERROR cannot find macro `default` in this scope
     default do
-    //~^ ERROR unmatched `default`
+    //~^ ERROR `default` not followed by an item
     //~| ERROR non-item in item list
 }
 
 struct S;
 impl S {
     default!(); //~ ERROR cannot find macro `default` in this scope
     default do
-    //~^ ERROR unmatched `default`
+    //~^ ERROR `default` not followed by an item
     //~| ERROR non-item in item list
 }

src/test/ui/parser/default-unmatched-assoc.stderr

@@ -1,8 +1,10 @@
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/default-unmatched-assoc.rs:5:5
    |
 LL |     default do
-   |     ^^^^^^^ the unmatched `default`
+   |     ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: non-item in item list
   --> $DIR/default-unmatched-assoc.rs:5:13
@@ -16,11 +18,13 @@ LL |     default do
 LL | }
    | - item list ends here
 
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/default-unmatched-assoc.rs:13:5
    |
 LL |     default do
-   |     ^^^^^^^ the unmatched `default`
+   |     ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: non-item in item list
   --> $DIR/default-unmatched-assoc.rs:13:13

src/test/ui/parser/default-unmatched-extern.rs

@@ -3,6 +3,6 @@ fn main() {}
 extern "C" {
     default!(); //~ ERROR cannot find macro `default` in this scope
     default do
-    //~^ ERROR unmatched `default`
+    //~^ ERROR `default` not followed by an item
     //~| ERROR non-item in item list
 }

src/test/ui/parser/default-unmatched-extern.stderr

@@ -1,8 +1,10 @@
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/default-unmatched-extern.rs:5:5
    |
 LL |     default do
-   |     ^^^^^^^ the unmatched `default`
+   |     ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: non-item in item list
   --> $DIR/default-unmatched-extern.rs:5:13

src/test/ui/parser/default-unmatched.rs

@@ -1,6 +1,6 @@
 mod foo {
     default!(); // OK.
     default do
-    //~^ ERROR unmatched `default`
+    //~^ ERROR `default` not followed by an item
     //~| ERROR expected item, found reserved keyword `do`
 }

src/test/ui/parser/default-unmatched.stderr

@@ -1,8 +1,10 @@
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/default-unmatched.rs:3:5
    |
 LL |     default do
-   |     ^^^^^^^ the unmatched `default`
+   |     ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: expected item, found reserved keyword `do`
   --> $DIR/default-unmatched.rs:3:13

src/test/ui/parser/default.rs

@@ -20,7 +20,7 @@ impl Foo for u16 {
 
 impl Foo for u32 { //~ ERROR not all trait items implemented, missing: `foo`
     default pub fn foo<T: Default>() -> T { T::default() }
-    //~^ ERROR unmatched `default`
+    //~^ ERROR `default` not followed by an item
     //~| ERROR non-item in item list
 }
 

src/test/ui/parser/default.stderr

@@ -1,8 +1,10 @@
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/default.rs:22:5
    |
 LL |     default pub fn foo<T: Default>() -> T { T::default() }
-   |     ^^^^^^^ the unmatched `default`
+   |     ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: non-item in item list
   --> $DIR/default.rs:22:13

src/test/ui/parser/duplicate-visibility.rs

@@ -2,6 +2,6 @@ fn main() {}
 
 extern {
     pub pub fn foo();
-    //~^ ERROR unmatched visibility `pub`
+    //~^ ERROR visibility `pub` not followed by an item
     //~| ERROR non-item in item list
 }

src/test/ui/parser/duplicate-visibility.stderr

@@ -1,8 +1,8 @@
-error: unmatched visibility `pub`
+error: visibility `pub` not followed by an item
   --> $DIR/duplicate-visibility.rs:4:5
    |
 LL |     pub pub fn foo();
-   |     ^^^ the unmatched visibility
+   |     ^^^ the visibility
    |
    = help: you likely meant to define an item, e.g., `pub fn foo() {}`
 

src/test/ui/parser/impl-parsing.rs

@@ -7,4 +7,4 @@ impl ?Sized for Type {} //~ ERROR expected a trait, found type
 impl ?Sized for .. {} //~ ERROR expected a trait, found type
 
 default unsafe FAIL //~ ERROR expected item, found keyword `unsafe`
-//~^ ERROR unmatched `default`
+//~^ ERROR `default` not followed by an item

src/test/ui/parser/impl-parsing.stderr

@@ -22,11 +22,13 @@ error: expected a trait, found type
 LL | impl ?Sized for .. {}
    |      ^^^^^^
 
-error: unmatched `default`
+error: `default` not followed by an item
   --> $DIR/impl-parsing.rs:9:1
    |
 LL | default unsafe FAIL
-   | ^^^^^^^ the unmatched `default`
+   | ^^^^^^^ the `default` qualifier
+   |
+   = note: only `fn`, `const`, `type`, or `impl` items may be prefixed by `default`
 
 error: expected item, found keyword `unsafe`
   --> $DIR/impl-parsing.rs:9:9

src/test/ui/parser/issue-41155.rs

@@ -1,7 +1,7 @@
 struct S;
 
 impl S {
-    pub //~ ERROR unmatched visibility `pub`
+    pub //~ ERROR visibility `pub` not followed by an item
 } //~ ERROR non-item in item list
 
 fn main() {}

src/test/ui/parser/issue-41155.stderr

@@ -1,8 +1,8 @@
-error: unmatched visibility `pub`
+error: visibility `pub` not followed by an item
   --> $DIR/issue-41155.rs:4:5
    |
 LL |     pub
-   |     ^^^ the unmatched visibility
+   |     ^^^ the visibility
    |
    = help: you likely meant to define an item, e.g., `pub fn foo() {}`
 

src/test/ui/pub/pub-restricted-error-fn.rs

@@ -1,2 +1,2 @@
-pub(crate) () fn foo() {} //~ unmatched visibility
+pub(crate) () fn foo() {} //~ ERROR visibility `pub(crate)` not followed by an item
 //~^ ERROR expected item, found `(`

src/test/ui/pub/pub-restricted-error-fn.stderr

@@ -1,8 +1,8 @@
-error: unmatched visibility `pub(crate)`
+error: visibility `pub(crate)` not followed by an item
   --> $DIR/pub-restricted-error-fn.rs:1:1
    |
 LL | pub(crate) () fn foo() {}
-   | ^^^^^^^^^^ the unmatched visibility
+   | ^^^^^^^^^^ the visibility
    |
    = help: you likely meant to define an item, e.g., `pub(crate) fn foo() {}`