Make E0599's label more clear for field which is used like a method.

fixes #127178

Author: surechen

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -2288,7 +2288,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
 
             let field_kind = if is_accessible { "field" } else { "private field" };
-            err.span_label(item_name.span, format!("{field_kind}, not a method"));
+            err.span_label(
+                item_name.span,
+                format!(
+                    "`{item_name}` is a {field_kind} \
+            in the current scope, but is used like a method"
+                ),
+            );
             return true;
         }
         false

tests/ui/confuse-field-and-method/issue-18343.stderr

@@ -5,7 +5,7 @@ LL | struct Obj<F> where F: FnMut() -> u32 {
    | ------------- method `closure` not found for this struct
 ...
 LL |     o.closure();
-   |       ^^^^^^^ field, not a method
+   |       ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |

tests/ui/confuse-field-and-method/issue-2392.stderr

@@ -5,7 +5,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `closure` not found for this struct
 ...
 LL |     o_closure.closure();
-   |               ^^^^^^^ field, not a method
+   |               ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |
@@ -21,7 +21,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
 LL |     o_closure.not_closure();
    |               ^^^^^^^^^^^-- help: remove the arguments
    |               |
-   |               field, not a method
+   |               `not_closure` is a field in the current scope, but is used like a method
 
 error[E0599]: no method named `closure` found for struct `Obj` in the current scope
   --> $DIR/issue-2392.rs:42:12
@@ -30,7 +30,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `closure` not found for this struct
 ...
 LL |     o_func.closure();
-   |            ^^^^^^^ field, not a method
+   |            ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |
@@ -44,7 +44,7 @@ LL | struct BoxedObj {
    | --------------- method `boxed_closure` not found for this struct
 ...
 LL |     boxed_fn.boxed_closure();
-   |              ^^^^^^^^^^^^^ field, not a method
+   |              ^^^^^^^^^^^^^ `boxed_closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `boxed_closure`, surround the field access with parentheses
    |
@@ -58,7 +58,7 @@ LL | struct BoxedObj {
    | --------------- method `boxed_closure` not found for this struct
 ...
 LL |     boxed_closure.boxed_closure();
-   |                   ^^^^^^^^^^^^^ field, not a method
+   |                   ^^^^^^^^^^^^^ `boxed_closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `boxed_closure`, surround the field access with parentheses
    |
@@ -72,7 +72,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `closure` not found for this struct
 ...
 LL |     w.wrap.closure();
-   |            ^^^^^^^ field, not a method
+   |            ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |
@@ -88,7 +88,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
 LL |     w.wrap.not_closure();
    |            ^^^^^^^^^^^-- help: remove the arguments
    |            |
-   |            field, not a method
+   |            `not_closure` is a field in the current scope, but is used like a method
 
 error[E0599]: no method named `closure` found for struct `Obj` in the current scope
   --> $DIR/issue-2392.rs:58:24
@@ -97,7 +97,7 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `closure` not found for this struct
 ...
 LL |     check_expression().closure();
-   |                        ^^^^^^^ field, not a method
+   |                        ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |
@@ -111,7 +111,7 @@ LL | struct FuncContainer {
    | -------------------- method `f1` not found for this struct
 ...
 LL |             (*self.container).f1(1);
-   |                               ^^ field, not a method
+   |                               ^^ `f1` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `f1`, surround the field access with parentheses
    |
@@ -125,7 +125,7 @@ LL | struct FuncContainer {
    | -------------------- method `f2` not found for this struct
 ...
 LL |             (*self.container).f2(1);
-   |                               ^^ field, not a method
+   |                               ^^ `f2` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `f2`, surround the field access with parentheses
    |
@@ -139,7 +139,7 @@ LL | struct FuncContainer {
    | -------------------- method `f3` not found for this struct
 ...
 LL |             (*self.container).f3(1);
-   |                               ^^ field, not a method
+   |                               ^^ `f3` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `f3`, surround the field access with parentheses
    |

tests/ui/confuse-field-and-method/issue-32128.stderr

@@ -5,7 +5,7 @@ LL | struct Example {
    | -------------- method `example` not found for this struct
 ...
 LL |     demo.example(1);
-   |          ^^^^^^^ field, not a method
+   |          ^^^^^^^ `example` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `example`, surround the field access with parentheses
    |

tests/ui/confuse-field-and-method/issue-33784.stderr

@@ -2,7 +2,7 @@ error[E0599]: no method named `closure` found for reference `&Obj<{closure@$DIR/
   --> $DIR/issue-33784.rs:27:7
    |
 LL |     p.closure();
-   |       ^^^^^^^ field, not a method
+   |       ^^^^^^^ `closure` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `closure`, surround the field access with parentheses
    |
@@ -17,7 +17,7 @@ error[E0599]: no method named `fn_ptr` found for reference `&&Obj<{closure@$DIR/
   --> $DIR/issue-33784.rs:29:7
    |
 LL |     q.fn_ptr();
-   |       ^^^^^^ field, not a method
+   |       ^^^^^^ `fn_ptr` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `fn_ptr`, surround the field access with parentheses
    |
@@ -28,7 +28,7 @@ error[E0599]: no method named `c_fn_ptr` found for reference `&D` in the current
   --> $DIR/issue-33784.rs:32:7
    |
 LL |     s.c_fn_ptr();
-   |       ^^^^^^^^ field, not a method
+   |       ^^^^^^^^ `c_fn_ptr` is a field in the current scope, but is used like a method
    |
 help: to call the function stored in `c_fn_ptr`, surround the field access with parentheses
    |

tests/ui/confuse-field-and-method/private-field.stderr

@@ -5,7 +5,7 @@ LL |     pub struct Dog {
    |     -------------- method `dog_age` not found for this struct
 ...
 LL |     let dog_age = dog.dog_age();
-   |                       ^^^^^^^ private field, not a method
+   |                       ^^^^^^^ `dog_age` is a private field in the current scope, but is used like a method
 
 error: aborting due to 1 previous error