Use multipart suggestions.

compiler/rustc_typeck/src/astconv/mod.rs

@@ -2617,30 +2617,39 @@ fn maybe_lint_bare_trait(&self, self_ty: &hir::Ty<'_>, in_path: bool) {
         if let hir::TyKind::TraitObject([poly_trait_ref, ..], _, TraitObjectSyntax::None) =
             self_ty.kind
         {
-            let (mut sugg, app) = match tcx.sess.source_map().span_to_snippet(self_ty.span) {
+            let needs_bracket = in_path
-                Ok(s) if poly_trait_ref.trait_ref.path.is_global() => {
+                && !tcx
-                    (format!("dyn ({})", s), Applicability::MachineApplicable)
-                }
-                Ok(s) => (format!("dyn {}", s), Applicability::MachineApplicable),
-                Err(_) => ("dyn <type>".to_string(), Applicability::HasPlaceholders),
-            };
-            if in_path {
-                let has_bracket = tcx
                     .sess
                     .source_map()
                     .span_to_prev_source(self_ty.span)
                     .ok()
                     .map_or(false, |s| s.trim_end().ends_with('<'));
-                if !has_bracket {
+
-                    sugg = format!("<{}>", sugg);
+            let is_global = poly_trait_ref.trait_ref.path.is_global();
-                }
+            let sugg = Vec::from_iter([
-            }
+                (
+                    self_ty.span.shrink_to_lo(),
+                    format!(
+                        "{}dyn {}",
+                        if needs_bracket { "<" } else { "" },
+                        if is_global { "(" } else { "" },
+                    ),
+                ),
+                (
+                    self_ty.span.shrink_to_hi(),
+                    format!(
+                        "{}{}",
+                        if is_global { ")" } else { "" },
+                        if needs_bracket { ">" } else { "" },
+                    ),
+                ),
+            ]);
             if self_ty.span.edition() >= Edition::Edition2021 {
                 let msg = "trait objects must include the `dyn` keyword";
                 let label = "add `dyn` keyword before this trait";
-                let mut err =
+                rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg)
-                    rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg);
+                    .multipart_suggestion_verbose(label, sugg, Applicability::MachineApplicable)
-                err.span_suggestion_verbose(self_ty.span, label, sugg, app).emit();
+                    .emit();
             } else {
                 let msg = "trait objects without an explicit `dyn` are deprecated";
                 tcx.struct_span_lint_hir(
@@ -2648,9 +2657,13 @@ fn maybe_lint_bare_trait(&self, self_ty: &hir::Ty<'_>, in_path: bool) {
                     self_ty.hir_id,
                     self_ty.span,
                     |lint| {
-                        let mut db = lint.build(msg);
+                        lint.build(msg)
-                        db.span_suggestion(self_ty.span, "use `dyn`", sugg, app);
+                            .multipart_suggestion_verbose(
-                        db.emit()
+                                "use `dyn`",
+                                sugg,
+                                Applicability::MachineApplicable,
+                            )
+                            .emit()
                     },
                 );
             }

src/test/ui/did_you_mean/bad-assoc-ty.stderr

@@ -103,11 +103,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/bad-assoc-ty.rs:33:10
    |
 LL | type H = Fn(u8) -> (u8)::Output;
-   |          ^^^^^^^^^^^^^^ help: use `dyn`: `<dyn Fn(u8) -> (u8)>`
+   |          ^^^^^^^^^^^^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL | type H = <dyn Fn(u8) -> (u8)>::Output;
+   |          ++++               +
 
 error[E0223]: ambiguous associated type
   --> $DIR/bad-assoc-ty.rs:33:10

src/test/ui/dyn-keyword/dyn-2018-edition-lint.stderr

@@ -2,7 +2,7 @@ error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:17
    |
 LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-   |                 ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                 ^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/dyn-2018-edition-lint.rs:2:8
@@ -11,15 +11,25 @@ LL | #[deny(bare_trait_objects)]
    |        ^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
+LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   | 
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:35
    |
 LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-   |                                   ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                                   ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
+LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   | 
 
 error: aborting due to 2 previous errors
 

src/test/ui/dyn-keyword/dyn-2021-edition-error.stderr

@@ -6,8 +6,9 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    |
 help: add `dyn` keyword before this trait
    |
-LL | fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-   |                 ~~~~~~~~~~~~~
+LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   | 
 
 error[E0782]: trait objects must include the `dyn` keyword
   --> $DIR/dyn-2021-edition-error.rs:3:35
@@ -17,8 +18,9 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    |
 help: add `dyn` keyword before this trait
    |
-LL | fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-   |                                   ~~~~~~~~~~~~~
+LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   | 
 
 error: aborting due to 2 previous errors
 

src/test/ui/dyn-keyword/dyn-angle-brackets.stderr

@@ -2,7 +2,7 @@ error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-angle-brackets.rs:15:10
    |
 LL |         <fmt::Debug>::fmt(self, f)
-   |          ^^^^^^^^^^ help: use `dyn`: `dyn fmt::Debug`
+   |          ^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/dyn-angle-brackets.rs:4:9
@@ -11,6 +11,11 @@ LL | #![deny(bare_trait_objects)]
    |         ^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -         <fmt::Debug>::fmt(self, f)
+LL +         <dyn fmt::Debug>::fmt(self, f)
+   | 
 
 error: aborting due to previous error
 

src/test/ui/editions/dyn-trait-sugg-2021.stderr

@@ -7,7 +7,7 @@ LL |     Foo::hi(123);
 help: add `dyn` keyword before this trait
    |
 LL |     <dyn Foo>::hi(123);
-   |     ~~~~~~~~~
+   |     ++++    +
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-28344.stderr

@@ -2,11 +2,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-28344.rs:4:17
    |
 LL |     let x: u8 = BitXor::bitor(0 as u8, 0 as u8);
-   |                 ^^^^^^ help: use `dyn`: `<dyn BitXor>`
+   |                 ^^^^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let x: u8 = <dyn BitXor>::bitor(0 as u8, 0 as u8);
+   |                 ++++       +
 
 error[E0191]: the value of the associated type `Output` (from trait `BitXor`) must be specified
   --> $DIR/issue-28344.rs:4:17
@@ -27,10 +31,14 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-28344.rs:10:13
    |
 LL |     let g = BitXor::bitor;
-   |             ^^^^^^ help: use `dyn`: `<dyn BitXor>`
+   |             ^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let g = <dyn BitXor>::bitor;
+   |             ++++       +
 
 error[E0191]: the value of the associated type `Output` (from trait `BitXor`) must be specified
   --> $DIR/issue-28344.rs:10:13

src/test/ui/issues/issue-58734.stderr

@@ -2,11 +2,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-58734.rs:20:5
    |
 LL |     Trait::nonexistent(());
-   |     ^^^^^ help: use `dyn`: `<dyn Trait>`
+   |     ^^^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     <dyn Trait>::nonexistent(());
+   |     ++++      +
 
 error[E0599]: no function or associated item named `nonexistent` found for trait object `dyn Trait` in the current scope
   --> $DIR/issue-58734.rs:20:12

src/test/ui/issues/issue-86756.stderr

@@ -18,11 +18,16 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-86756.rs:5:15
    |
 LL |     eq::<dyn, Foo>
-   |               ^^^ help: use `dyn`: `dyn Foo`
+   |               ^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -     eq::<dyn, Foo>
+LL +     eq::<dyn, dyn Foo>
+   | 
 
 error[E0107]: missing generics for trait `Foo`
   --> $DIR/issue-86756.rs:5:15

src/test/ui/lint/bare-trait-objects-path.stderr

@@ -2,11 +2,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/bare-trait-objects-path.rs:23:12
    |
 LL |     let _: Dyn::Ty;
-   |            ^^^ help: use `dyn`: `<dyn Dyn>`
+   |            ^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let _: <dyn Dyn>::Ty;
+   |            ++++    +
 
 error[E0223]: ambiguous associated type
   --> $DIR/bare-trait-objects-path.rs:23:12
@@ -18,28 +22,40 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/bare-trait-objects-path.rs:14:5
    |
 LL |     Dyn::func();
-   |     ^^^ help: use `dyn`: `<dyn Dyn>`
+   |     ^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     <dyn Dyn>::func();
+   |     ++++    +
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/bare-trait-objects-path.rs:17:5
    |
 LL |     ::Dyn::func();
-   |     ^^^^^ help: use `dyn`: `<dyn (::Dyn)>`
+   |     ^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     <dyn (::Dyn)>::func();
+   |     ++++++     ++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/bare-trait-objects-path.rs:20:5
    |
 LL |     Dyn::CONST;
-   |     ^^^ help: use `dyn`: `<dyn Dyn>`
+   |     ^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     <dyn Dyn>::CONST;
+   |     ++++    +
 
 error: aborting due to previous error; 4 warnings emitted
 

src/test/ui/lint/force-warn/allowed-group-warn-by-default-lint.stderr

@@ -2,29 +2,44 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/allowed-group-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = note: requested on the command line with `--force-warn bare-trait-objects`
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/allowed-group-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/allowed-group-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: 3 warnings emitted
 

src/test/ui/lint/force-warn/cap-lints-allow.stderr

@@ -2,29 +2,44 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/cap-lints-allow.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = note: requested on the command line with `--force-warn bare-trait-objects`
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/cap-lints-allow.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/cap-lints-allow.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: 3 warnings emitted
 

src/test/ui/lint/force-warn/lint-group-allowed-cli-warn-by-default-lint.stderr

@@ -2,29 +2,44 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-cli-warn-by-default-lint.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = note: `--force-warn bare-trait-objects` implied by `--force-warn rust-2018-idioms`
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-cli-warn-by-default-lint.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-cli-warn-by-default-lint.rs:8:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: 3 warnings emitted
 

src/test/ui/lint/force-warn/lint-group-allowed-lint-group.stderr

@@ -2,29 +2,44 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-lint-group.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = note: `--force-warn bare-trait-objects` implied by `--force-warn rust-2018-idioms`
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-lint-group.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-lint-group.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: 3 warnings emitted
 

src/test/ui/lint/force-warn/lint-group-allowed-warn-by-default-lint.stderr

@@ -2,29 +2,44 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = note: `--force-warn bare-trait-objects` implied by `--force-warn rust-2018-idioms`
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-warn-by-default-lint.rs:10:25
    |
 LL | pub fn function(_x: Box<SomeTrait>) {}
-   |                         ^^^^^^^^^ help: use `dyn`: `dyn SomeTrait`
+   |                         ^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub fn function(_x: Box<SomeTrait>) {}
+LL + pub fn function(_x: Box<dyn SomeTrait>) {}
+   | 
 
 warning: 3 warnings emitted
 

src/test/ui/parser/trait-object-trait-parens.stderr

@@ -20,11 +20,16 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/trait-object-trait-parens.rs:8:16
    |
 LL |     let _: Box<(Obj) + (?Sized) + (for<'a> Trait<'a>)>;
-   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn (Obj) + (?Sized) + (for<'a> Trait<'a>)`
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -     let _: Box<(Obj) + (?Sized) + (for<'a> Trait<'a>)>;
+LL +     let _: Box<dyn (Obj) + (?Sized) + (for<'a> Trait<'a>)>;
+   | 
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:8:35
@@ -41,10 +46,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/trait-object-trait-parens.rs:13:16
    |
 LL |     let _: Box<?Sized + (for<'a> Trait<'a>) + (Obj)>;
-   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn ?Sized + (for<'a> Trait<'a>) + (Obj)`
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -     let _: Box<?Sized + (for<'a> Trait<'a>) + (Obj)>;
+LL +     let _: Box<dyn ?Sized + (for<'a> Trait<'a>) + (Obj)>;
+   | 
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:13:47
@@ -61,10 +71,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/trait-object-trait-parens.rs:18:16
    |
 LL |     let _: Box<for<'a> Trait<'a> + (Obj) + (?Sized)>;
-   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> Trait<'a> + (Obj) + (?Sized)`
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -     let _: Box<for<'a> Trait<'a> + (Obj) + (?Sized)>;
+LL +     let _: Box<dyn for<'a> Trait<'a> + (Obj) + (?Sized)>;
+   | 
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:18:36

src/test/ui/suggestions/issue-61963.stderr

@@ -2,7 +2,7 @@ error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:22:14
    |
 LL |     bar: Box<Bar>,
-   |              ^^^ help: use `dyn`: `dyn Bar`
+   |              ^^^
    |
 note: the lint level is defined here
   --> $DIR/issue-61963.rs:3:9
@@ -11,15 +11,25 @@ LL | #![deny(bare_trait_objects)]
    |         ^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL -     bar: Box<Bar>,
+LL +     bar: Box<dyn Bar>,
+   | 
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:18:1
    |
 LL | pub struct Foo {
-   | ^^^ help: use `dyn`: `dyn pub`
+   | ^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - pub struct Foo {
+LL + dyn pub struct Foo {
+   | 
 
 error: aborting due to 2 previous errors
 

src/test/ui/traits/bound/not-on-bare-trait.stderr

@@ -2,11 +2,16 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/not-on-bare-trait.rs:7:12
    |
 LL | fn foo(_x: Foo + Send) {
-   |            ^^^^^^^^^^ help: use `dyn`: `dyn Foo + Send`
+   |            ^^^^^^^^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL - fn foo(_x: Foo + Send) {
+LL + fn foo(_x: dyn Foo + Send) {
+   | 
 
 error[E0277]: the size for values of type `(dyn Foo + Send + 'static)` cannot be known at compilation time
   --> $DIR/not-on-bare-trait.rs:7:8

src/test/ui/unspecified-self-in-trait-ref.stderr

@@ -2,11 +2,15 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/unspecified-self-in-trait-ref.rs:10:13
    |
 LL |     let a = Foo::lol();
-   |             ^^^ help: use `dyn`: `<dyn Foo>`
+   |             ^^^
    |
    = note: `#[warn(bare_trait_objects)]` on by default
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let a = <dyn Foo>::lol();
+   |             ++++    +
 
 error[E0599]: no function or associated item named `lol` found for trait object `dyn Foo<_>` in the current scope
   --> $DIR/unspecified-self-in-trait-ref.rs:10:18
@@ -18,10 +22,14 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/unspecified-self-in-trait-ref.rs:14:13
    |
 LL |     let b = Foo::<_>::lol();
-   |             ^^^^^^^^ help: use `dyn`: `<dyn Foo::<_>>`
+   |             ^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let b = <dyn Foo::<_>>::lol();
+   |             ++++         +
 
 error[E0599]: no function or associated item named `lol` found for trait object `dyn Foo<_>` in the current scope
   --> $DIR/unspecified-self-in-trait-ref.rs:14:23
@@ -33,10 +41,14 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/unspecified-self-in-trait-ref.rs:18:13
    |
 LL |     let c = Bar::lol();
-   |             ^^^ help: use `dyn`: `<dyn Bar>`
+   |             ^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let c = <dyn Bar>::lol();
+   |             ++++    +
 
 error[E0599]: no function or associated item named `lol` found for trait object `dyn Bar<_, _>` in the current scope
   --> $DIR/unspecified-self-in-trait-ref.rs:18:18
@@ -48,10 +60,14 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/unspecified-self-in-trait-ref.rs:22:13
    |
 LL |     let d = Bar::<usize, _>::lol();
-   |             ^^^^^^^^^^^^^^^ help: use `dyn`: `<dyn Bar::<usize, _>>`
+   |             ^^^^^^^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let d = <dyn Bar::<usize, _>>::lol();
+   |             ++++                +
 
 error[E0599]: no function or associated item named `lol` found for trait object `dyn Bar<usize, _>` in the current scope
   --> $DIR/unspecified-self-in-trait-ref.rs:22:30
@@ -63,10 +79,14 @@ warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/unspecified-self-in-trait-ref.rs:26:13
    |
 LL |     let e = Bar::<usize>::lol();
-   |             ^^^^^^^^^^^^ help: use `dyn`: `<dyn Bar::<usize>>`
+   |             ^^^^^^^^^^^^
    |
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
+help: use `dyn`
+   |
+LL |     let e = <dyn Bar::<usize>>::lol();
+   |             ++++             +
 
 error[E0393]: the type parameter `A` must be explicitly specified
   --> $DIR/unspecified-self-in-trait-ref.rs:26:13