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

@@ -2277,7 +2277,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let call_expr = tcx.hir().expect_expr(tcx.parent_hir_id(expr.hir_id));
 
                     if let Some(span) = call_expr.span.trim_start(item_name.span) {
-                        err.span_suggestion(
+                        err.span_suggestion_verbose(
                             span,
                             "remove the arguments",
                             "",
@@ -3266,7 +3266,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 .copied();
 
             if explain {
-                err.help("items from traits can only be used if the trait is in scope");
+                err.help(
+                    "items from traits can only be used if the trait is implemented and in scope",
+                );
             }
 
             let msg = format!(
@@ -3570,7 +3572,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             }
         }
-        if self.suggest_valid_traits(err, item_name, valid_out_of_scope_traits, true) {
+        if self.suggest_valid_traits(
+            err,
+            item_name,
+            valid_out_of_scope_traits,
+            !trait_missing_method,
+        ) {
             return;
         }
 

tests/ui/async-await/in-trait/dont-project-to-specializable-projection.stderr

@@ -29,7 +29,7 @@ LL |         match fut.as_mut().poll(ctx) {
    |
    = note: the method is available for `Pin<&mut impl Future<Output = ()>>` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Future` which provides `poll` is implemented but not in scope; perhaps you want to import it
    |
 LL + use std::future::Future;

tests/ui/coherence/coherence_inherent.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `the_fn` found for reference `&TheStruct` in the c
 LL |         s.the_fn();
    |           ^^^^^^ method not found in `&TheStruct`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `TheTrait` which provides `the_fn` is implemented but not in scope; perhaps you want to import it
    |
 LL +     use Lib::TheTrait;

tests/ui/coherence/coherence_inherent_cc.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `the_fn` found for reference `&TheStruct` in the c
 LL |         s.the_fn();
    |           ^^^^^^ method not found in `&TheStruct`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `TheTrait` which provides `the_fn` is implemented but not in scope; perhaps you want to import it
    |
 LL +     use coherence_inherent_cc_lib::TheTrait;

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

@@ -19,9 +19,13 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `not_closure` not found for this struct
 ...
 LL |     o_closure.not_closure();
-   |               ^^^^^^^^^^^-- help: remove the arguments
-   |               |
-   |               field, not a method
+   |               ^^^^^^^^^^^ field, not a method
+   |
+help: remove the arguments
+   |
+LL -     o_closure.not_closure();
+LL +     o_closure.not_closure;
+   |
 
 error[E0599]: no method named `closure` found for struct `Obj` in the current scope
   --> $DIR/issue-2392.rs:42:12
@@ -86,9 +90,13 @@ LL | struct Obj<F> where F: FnOnce() -> u32 {
    | ------------- method `not_closure` not found for this struct
 ...
 LL |     w.wrap.not_closure();
-   |            ^^^^^^^^^^^-- help: remove the arguments
-   |            |
-   |            field, not a method
+   |            ^^^^^^^^^^^ field, not a method
+   |
+help: remove the arguments
+   |
+LL -     w.wrap.not_closure();
+LL +     w.wrap.not_closure;
+   |
 
 error[E0599]: no method named `closure` found for struct `Obj` in the current scope
   --> $DIR/issue-2392.rs:58:24

tests/ui/generic-associated-types/method-unsatisfied-assoc-type-predicate.rs

@@ -26,6 +26,7 @@ fn f(a: S) {
     a.f();
     //~^ ERROR the method `f` exists for struct `S`, but its trait bounds were not satisfied
     //~| NOTE method cannot be called on `S` due to unsatisfied trait bounds
+    //~| HELP items from traits can only be used if the trait is implemented and in scope
 }
 
 fn main() {}

tests/ui/hygiene/no_implicit_prelude.stderr

@@ -22,7 +22,7 @@ LL |     fn f() { ::bar::m!(); }
 LL |         ().clone()
    |            ^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: there is a method `clone_from` with a similar name, but with different arguments
   --> $SRC_DIR/core/src/clone.rs:LL:COL
    = note: this error originates in the macro `::bar::m` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/hygiene/trait_items.stderr

@@ -10,7 +10,7 @@ LL |     fn f() { ::baz::m!(); }
 LL |     pub macro m() { ().f() }
    |                        ^ method not found in `()`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
    = note: this error originates in the macro `::baz::m` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: trait `T` which provides `f` is implemented but not in scope; perhaps you want to import it
    |

tests/ui/impl-trait/call_method_without_import.no_import.stderr

@@ -7,7 +7,7 @@ LL |         x.fmt(f);
    |
    = note: the method is available for `impl Debug` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Debug` which provides `fmt` is implemented but not in scope; perhaps you want to import it
    |
 LL + use std::fmt::Debug;
@@ -19,7 +19,7 @@ error[E0599]: no method named `fmt` found for mutable reference `&mut impl Debug
 LL |         x.fmt(f);
    |           ^^^ method not found in `&mut impl Debug`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: the following traits which provide `fmt` are implemented but not in scope; perhaps you want to import one of them
    |
 LL + use std::fmt::Binary;

tests/ui/impl-trait/no-method-suggested-traits.rs

@@ -22,9 +22,9 @@ fn main() {
 
     1u32.method();
     //~^ ERROR no method named
-    //~|items from traits can only be used if the trait is in scope
+    //~|items from traits can only be used if the trait is implemented and in scope
     std::rc::Rc::new(&mut Box::new(&1u32)).method();
-    //~^items from traits can only be used if the trait is in scope
+    //~^items from traits can only be used if the trait is implemented and in scope
     //~| ERROR no method named `method` found for struct
 
     'a'.method();

tests/ui/impl-trait/no-method-suggested-traits.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `method` found for type `u32` in the current scope
 LL |     1u32.method();
    |          ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: the following traits which provide `method` are implemented but not in scope; perhaps you want to import one of them
    |
 LL + use foo::Bar;
@@ -26,7 +26,7 @@ error[E0599]: no method named `method` found for struct `Rc<&mut Box<&u32>>` in
 LL |     std::rc::Rc::new(&mut Box::new(&1u32)).method();
    |                                            ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: the following traits which provide `method` are implemented but not in scope; perhaps you want to import one of them
    |
 LL + use foo::Bar;
@@ -51,7 +51,7 @@ LL |         fn method(&self) {}
 LL |     'a'.method();
    |         ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Bar` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use foo::Bar;
@@ -67,7 +67,7 @@ error[E0599]: no method named `method` found for struct `Rc<&mut Box<&char>>` in
 LL |     std::rc::Rc::new(&mut Box::new(&'a')).method();
    |                                           ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Bar` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use foo::Bar;
@@ -88,7 +88,7 @@ LL |     1i32.method();
 LL |         fn method(&self) {}
    |            ------ the method is available for `i32` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `PubPub` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use no_method_suggested_traits::foo::PubPub;
@@ -104,7 +104,7 @@ error[E0599]: no method named `method` found for struct `Rc<&mut Box<&i32>>` in
 LL |     std::rc::Rc::new(&mut Box::new(&1i32)).method();
    |                                            ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `PubPub` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use no_method_suggested_traits::foo::PubPub;

tests/ui/imports/overlapping_pub_trait.rs

@@ -11,5 +11,5 @@ fn main() {
     use overlapping_pub_trait_source::S;
     S.method();
     //~^ ERROR no method named `method` found for struct `S` in the current scope [E0599]
-    //~| HELP items from traits can only be used if the trait is in scope
+    //~| HELP items from traits can only be used if the trait is implemented and in scope
 }

tests/ui/imports/overlapping_pub_trait.stderr

@@ -9,7 +9,7 @@ LL |     S.method();
 LL |     pub trait Tr { fn method(&self); }
    |                       ------ the method is available for `S` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Tr` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use overlapping_pub_trait_source::m::Tr;

tests/ui/imports/unnamed_pub_trait.rs

@@ -12,5 +12,5 @@ fn main() {
     use unnamed_pub_trait_source::S;
     S.method();
     //~^ ERROR no method named `method` found for struct `S` in the current scope [E0599]
-    //~| HELP items from traits can only be used if the trait is in scope
+    //~| HELP items from traits can only be used if the trait is implemented and in scope
 }

tests/ui/imports/unnamed_pub_trait.stderr

@@ -9,7 +9,7 @@ LL |     S.method();
 LL |     pub trait Tr { fn method(&self); }
    |                       ------ the method is available for `S` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Tr` which provides `method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use unnamed_pub_trait_source::prelude::*; // trait Tr

tests/ui/issues/issue-10465.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `foo` found for reference `&B` in the current scop
 LL |             b.foo();
    |               ^^^ method not found in `&B`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `A` which provides `foo` is implemented but not in scope; perhaps you want to import it
    |
 LL +         use a::A;

tests/ui/issues/issue-39175.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `exec` found for mutable reference `&mut Command`
 LL |     Command::new("echo").arg("hello").exec();
    |                                       ^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: there is a method `pre_exec` with a similar name, but with different arguments
   --> $SRC_DIR/std/src/os/unix/process.rs:LL:COL
 help: trait `CommandExt` which provides `exec` is implemented but not in scope; perhaps you want to import it

tests/ui/issues/issue-56175.stderr

@@ -9,7 +9,7 @@ LL |     reexported_trait::FooStruct.trait_method();
 LL |         fn trait_method(&self) {
    |            ------------ the method is available for `FooStruct` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Trait` which provides `trait_method` is implemented but not in scope; perhaps you want to import it
    |
 LL + use reexported_trait::Trait;
@@ -30,7 +30,7 @@ LL |     reexported_trait::FooStruct.trait_method_b();
 LL |         fn trait_method_b(&self) {
    |            -------------- the method is available for `FooStruct` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `TraitB` which provides `trait_method_b` is implemented but not in scope; perhaps you want to import it
    |
 LL + use reexported_trait::TraitBRename;

tests/ui/methods/field-method-suggestion-using-return-ty.rs

@@ -4,14 +4,14 @@ impl Wrapper<Option<i32>> {
     fn inner_mut(&self) -> Option<&mut i32> {
         self.as_mut()
         //~^ ERROR no method named `as_mut` found for reference `&Wrapper<Option<i32>>` in the current scope
+        //~| HELP items from traits can only be used if the trait is implemented and in scope
         //~| HELP one of the expressions' fields has a method of the same name
-        //~| HELP items from traits can only be used if
     }
 
     fn inner_mut_bad(&self) -> Option<&mut u32> {
         self.as_mut()
         //~^ ERROR no method named `as_mut` found for reference `&Wrapper<Option<i32>>` in the current scope
-        //~| HELP items from traits can only be used if
+        //~| HELP items from traits can only be used if the trait is implemented and in scope
     }
 }
 

tests/ui/rust-2018/trait-import-suggestions.stderr

@@ -7,7 +7,7 @@ LL |             fn foobar(&self) { }
 LL |         x.foobar();
    |           ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Foobar` which provides `foobar` is implemented but not in scope; perhaps you want to import it
    |
 LL +     use crate::foo::foobar::Foobar;
@@ -26,7 +26,7 @@ LL |         fn bar(&self) { }
 LL |     x.bar();
    |       ^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Bar` which provides `bar` is implemented but not in scope; perhaps you want to import it
    |
 LL + use crate::foo::Bar;
@@ -53,7 +53,7 @@ error[E0599]: no function or associated item named `from_str` found for type `u3
 LL |     let y = u32::from_str("33");
    |                  ^^^^^^^^ function or associated item not found in `u32`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `FromStr` which provides `from_str` is implemented but not in scope; perhaps you want to import it
    |
 LL + use std::str::FromStr;

tests/ui/rust-2018/uniform-paths/issue-87932.stderr

@@ -7,7 +7,7 @@ LL | pub struct A {}
 LL |     A::deserialize();
    |        ^^^^^^^^^^^ function or associated item not found in `A`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Deserialize` which provides `deserialize` is implemented but not in scope; perhaps you want to import it
    |
 LL + use <crate::A as issue_87932_a::Deserialize>::deserialize::_a::Deserialize;

tests/ui/rust-2021/future-prelude-collision-shadow.stderr

@@ -4,7 +4,7 @@ error[E0599]: no method named `try_into` found for type `u8` in the current scop
 LL |         let _: u32 = 3u8.try_into().unwrap();
    |                          ^^^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
    = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021
 help: the following traits which provide `try_into` are implemented but not in scope; perhaps you want to import one of them
    |

tests/ui/shadowed/shadowed-trait-methods.stderr

@@ -7,7 +7,7 @@ LL |     pub trait T { fn f(&self) {} }
 LL |     ().f()
    |        ^ method not found in `()`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `T` which provides `f` is implemented but not in scope; perhaps you want to import it
    |
 LL + use foo::T;

tests/ui/suggestions/dont-wrap-ambiguous-receivers.rs

@@ -17,5 +17,5 @@ mod banana {
 fn main() {
     banana::Chaenomeles.pick()
     //~^ ERROR no method named
-    //~| HELP items from traits can only be used if the trait is in scope
+    //~| HELP items from traits can only be used if the trait is implemented and in scope
 }

tests/ui/suggestions/dont-wrap-ambiguous-receivers.stderr

@@ -7,7 +7,7 @@ LL |     pub struct Chaenomeles;
 LL |     banana::Chaenomeles.pick()
    |                         ^^^^ method not found in `Chaenomeles`
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: the following traits which provide `pick` are implemented but not in scope; perhaps you want to import one of them
    |
 LL + use banana::Apple;

tests/ui/suggestions/import-trait-for-method-call.stderr

@@ -7,7 +7,7 @@ LL |     h.finish()
    |
    = note: the method is available for `DefaultHasher` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Hasher` which provides `finish` is implemented but not in scope; perhaps you want to import it
    |
 LL + use std::hash::Hasher;

tests/ui/suggestions/suggest-tryinto-edition-change.stderr

@@ -47,7 +47,7 @@ LL |     let _i: i16 = 0_i32.try_into().unwrap();
    |
    = note: the method is available for `i32` here
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
    = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021
 help: trait `TryInto` which provides `try_into` is implemented but not in scope; perhaps you want to import it
    |

tests/ui/suggestions/use-placement-typeck.stderr

@@ -10,7 +10,7 @@ LL |     }
 LL |     pub struct S;
    |     ------------ method `abc` not found for this struct
    |
-   = help: items from traits can only be used if the trait is in scope
+   = help: items from traits can only be used if the trait is implemented and in scope
 help: trait `Foo` which provides `abc` is implemented but not in scope; perhaps you want to import it
    |
 LL + use m::Foo;