Improve error message for E0424

src/librustc_resolve/lib.rs

@@ -3009,7 +3009,8 @@ fn smart_resolve_path_fragment(&mut self,
             if is_self_value(path, ns) {
                 __diagnostic_used!(E0424);
                 err.code(DiagnosticId::Error("E0424".into()));
-                err.span_label(span, format!("`self` value is only available in \
+                err.span_label(span, format!("`self` value is a keyword \
+                                               only available in \
                                                methods with `self` parameter"));
                 return (err, Vec::new());
             }
@@ -3052,7 +3053,8 @@ fn smart_resolve_path_fragment(&mut self,
                                 Applicability::MachineApplicable,
                             );
                             if !self_is_available {
-                                err.span_label(span, format!("`self` value is only available in \
+                                err.span_label(span, format!("`self` value is a keyword \
+                                                               only available in \
                                                                methods with `self` parameter"));
                             }
                         }

src/test/ui/error-codes/E0424.stderr

@@ -2,7 +2,7 @@ error[E0424]: expected value, found module `self`
   --> $DIR/E0424.rs:17:9
    |
 LL |         self.bar(); //~ ERROR E0424
-   |         ^^^^ `self` value is only available in methods with `self` parameter
+   |         ^^^^ `self` value is a keyword only available in methods with `self` parameter
 
 error: aborting due to previous error
 

src/test/ui/resolve/issue-2356.stderr

@@ -22,7 +22,7 @@ error[E0425]: cannot find value `whiskers` in this scope
 LL |     whiskers -= other;
    |     ^^^^^^^^
    |     |
-   |     `self` value is only available in methods with `self` parameter
+   |     `self` value is a keyword only available in methods with `self` parameter
    |     help: try: `self.whiskers`
 
 error[E0425]: cannot find function `shave` in this scope
@@ -65,7 +65,7 @@ error[E0424]: expected value, found module `self`
   --> $DIR/issue-2356.rs:75:8
    |
 LL |     if self.whiskers > 3 {
-   |        ^^^^ `self` value is only available in methods with `self` parameter
+   |        ^^^^ `self` value is a keyword only available in methods with `self` parameter
 
 error[E0425]: cannot find function `grow_older` in this scope
   --> $DIR/issue-2356.rs:82:5
@@ -91,7 +91,7 @@ error[E0425]: cannot find value `whiskers` in this scope
 LL |     whiskers = 4;
    |     ^^^^^^^^
    |     |
-   |     `self` value is only available in methods with `self` parameter
+   |     `self` value is a keyword only available in methods with `self` parameter
    |     help: try: `self.whiskers`
 
 error[E0425]: cannot find function `purr_louder` in this scope
@@ -104,7 +104,7 @@ error[E0424]: expected value, found module `self`
   --> $DIR/issue-2356.rs:102:5
    |
 LL |     self += 1;
-   |     ^^^^ `self` value is only available in methods with `self` parameter
+   |     ^^^^ `self` value is a keyword only available in methods with `self` parameter
 
 error: aborting due to 17 previous errors
 

src/test/ui/resolve/unresolved_static_type_field.stderr

@@ -4,7 +4,7 @@ error[E0425]: cannot find value `cx` in this scope
 LL |         f(cx);
    |           ^^
    |           |
-   |           `self` value is only available in methods with `self` parameter
+   |           `self` value is a keyword only available in methods with `self` parameter
    |           help: try: `self.cx`
 
 error: aborting due to previous error