Tweak trait modifier errors

compiler/rustc_parse/messages.ftl

@@ -869,10 +869,10 @@ parse_trait_alias_cannot_be_auto = trait aliases cannot be `auto`
 parse_trait_alias_cannot_be_const = trait aliases cannot be `const`
 parse_trait_alias_cannot_be_unsafe = trait aliases cannot be `unsafe`
 
-parse_trait_impl_modifier_in_inherent_impl = inherent impls cannot be {$annotation}
-    .because = {$annotation} because of this
+parse_trait_impl_modifier_in_inherent_impl = inherent impls cannot be {$modifier_name}
+    .because = {$modifier_name} because of this
     .type = inherent impl for this type
-    .only_trait = only trait implementations may be annotated with {$annotation}
+    .note = only trait implementations may be annotated with `{$modifier}`
 
 parse_transpose_dyn_or_impl = `for<...>` expected after `{$kw}`, not before
     .suggestion = move `{$kw}` before the `for<...>`

compiler/rustc_parse/src/errors.rs

@@ -73,16 +73,16 @@ pub(crate) struct BadQPathStage2 {
 
 #[derive(Diagnostic)]
 #[diag(parse_trait_impl_modifier_in_inherent_impl)]
-pub(crate) struct TraitImplModifierInInherentImpl<'a> {
+#[note]
+pub(crate) struct TraitImplModifierInInherentImpl {
     #[primary_span]
     pub span: Span,
+    pub modifier: &'static str,
+    pub modifier_name: &'static str,
     #[label(parse_because)]
-    pub annotation_span: Span,
-    pub annotation: &'a str,
+    pub modifier_span: Span,
     #[label(parse_type)]
     pub self_ty: Span,
-    #[note(parse_only_trait)]
-    pub only_trait: bool,
 }
 
 #[derive(Subdiagnostic)]

compiler/rustc_parse/src/parser/item.rs

@@ -667,36 +667,27 @@ fn parse_item_impl(
             }
             None => {
                 let self_ty = ty_first;
-                let error = |annotation_span, annotation, only_trait| {
-                    errors::TraitImplModifierInInherentImpl {
+                let error = |modifier, modifier_name, modifier_span| {
+                    self.dcx().create_err(errors::TraitImplModifierInInherentImpl {
                         span: self_ty.span,
-                        annotation_span,
-                        annotation,
+                        modifier,
+                        modifier_name,
+                        modifier_span,
                         self_ty: self_ty.span,
-                        only_trait,
-                    }
+                    })
                 };
 
                 if let Safety::Unsafe(span) = safety {
-                    self.dcx()
-                        .create_err(errors::TraitImplModifierInInherentImpl {
-                            span: self_ty.span,
-                            annotation_span: span,
-                            annotation: "unsafe",
-                            self_ty: self_ty.span,
-                            only_trait: true,
-                        })
-                        .with_code(E0197)
-                        .emit();
+                    error("unsafe", "unsafe", span).with_code(E0197).emit();
                 }
                 if let ImplPolarity::Negative(span) = polarity {
-                    self.dcx().emit_err(error(span, "negative", false));
+                    error("!", "negative", span).emit();
                 }
                 if let Defaultness::Default(def_span) = defaultness {
-                    self.dcx().emit_err(error(def_span, "`default`", true));
+                    error("default", "default", def_span).emit();
                 }
                 if let Const::Yes(span) = constness {
-                    self.dcx().emit_err(error(span, "`const`", true));
+                    error("const", "const", span).emit();
                 }
                 (None, self_ty)
             }

tests/ui/error-codes/E0197.stderr

@@ -6,7 +6,7 @@ LL | unsafe impl Foo { }
    | |
    | unsafe because of this
    |
-   = note: only trait implementations may be annotated with unsafe
+   = note: only trait implementations may be annotated with `unsafe`
 
 error: aborting due to 1 previous error
 

tests/ui/parser/default-on-wrong-item-kind.rs

@@ -19,7 +19,7 @@ mod free_items {
     default union foo {} //~ ERROR a union cannot be `default`
     default trait foo {} //~ ERROR a trait cannot be `default`
     default trait foo = Ord; //~ ERROR a trait alias cannot be `default`
-    default impl foo {} //~ ERROR inherent impls cannot be `default`
+    default impl foo {} //~ ERROR inherent impls cannot be default
     default!();
     default::foo::bar!();
     default default!(); //~ ERROR an item macro invocation cannot be `default`
@@ -53,7 +53,7 @@ mod free_items {
     //~^ ERROR trait is not supported in `extern` blocks
     default trait foo = Ord; //~ ERROR a trait alias cannot be `default`
     //~^ ERROR trait alias is not supported in `extern` blocks
-    default impl foo {} //~ ERROR inherent impls cannot be `default`
+    default impl foo {} //~ ERROR inherent impls cannot be default
     //~^ ERROR implementation is not supported in `extern` blocks
     default!();
     default::foo::bar!();
@@ -90,7 +90,7 @@ impl S {
     //~^ ERROR trait is not supported in `trait`s or `impl`s
     default trait foo = Ord; //~ ERROR a trait alias cannot be `default`
     //~^ ERROR trait alias is not supported in `trait`s or `impl`s
-    default impl foo {} //~ ERROR inherent impls cannot be `default`
+    default impl foo {} //~ ERROR inherent impls cannot be default
     //~^ ERROR implementation is not supported in `trait`s or `impl`s
     default!();
     default::foo::bar!();
@@ -127,7 +127,7 @@ trait T {
     //~^ ERROR trait is not supported in `trait`s or `impl`s
     default trait foo = Ord; //~ ERROR a trait alias cannot be `default`
     //~^ ERROR trait alias is not supported in `trait`s or `impl`s
-    default impl foo {} //~ ERROR inherent impls cannot be `default`
+    default impl foo {} //~ ERROR inherent impls cannot be default
     //~^ ERROR implementation is not supported in `trait`s or `impl`s
     default!();
     default::foo::bar!();

tests/ui/parser/default-on-wrong-item-kind.stderr

@@ -78,13 +78,13 @@ LL |     default trait foo = Ord;
    |
    = note: only associated `fn`, `const`, and `type` items can be `default`
 
-error: inherent impls cannot be `default`
+error: inherent impls cannot be default
   --> $DIR/default-on-wrong-item-kind.rs:22:18
    |
 LL |     default impl foo {}
    |     -------      ^^^ inherent impl for this type
    |     |
-   |     `default` because of this
+   |     default because of this
    |
    = note: only trait implementations may be annotated with `default`
 
@@ -285,13 +285,13 @@ LL |     default trait foo = Ord;
    |
    = help: consider moving the trait alias out to a nearby module scope
 
-error: inherent impls cannot be `default`
+error: inherent impls cannot be default
   --> $DIR/default-on-wrong-item-kind.rs:56:18
    |
 LL |     default impl foo {}
    |     -------      ^^^ inherent impl for this type
    |     |
-   |     `default` because of this
+   |     default because of this
    |
    = note: only trait implementations may be annotated with `default`
 
@@ -509,13 +509,13 @@ LL |     default trait foo = Ord;
    |
    = help: consider moving the trait alias out to a nearby module scope
 
-error: inherent impls cannot be `default`
+error: inherent impls cannot be default
   --> $DIR/default-on-wrong-item-kind.rs:93:18
    |
 LL |     default impl foo {}
    |     -------      ^^^ inherent impl for this type
    |     |
-   |     `default` because of this
+   |     default because of this
    |
    = note: only trait implementations may be annotated with `default`
 
@@ -733,13 +733,13 @@ LL |     default trait foo = Ord;
    |
    = help: consider moving the trait alias out to a nearby module scope
 
-error: inherent impls cannot be `default`
+error: inherent impls cannot be default
   --> $DIR/default-on-wrong-item-kind.rs:130:18
    |
 LL |     default impl foo {}
    |     -------      ^^^ inherent impl for this type
    |     |
-   |     `default` because of this
+   |     default because of this
    |
    = note: only trait implementations may be annotated with `default`
 

tests/ui/specialization/defaultimpl/validation.rs

@@ -4,7 +4,7 @@
 struct S;
 struct Z;
 
-default impl S {} //~ ERROR inherent impls cannot be `default`
+default impl S {} //~ ERROR inherent impls cannot be default
 
 default unsafe impl Send for S {}
 //~^ ERROR impls of auto traits cannot be default

tests/ui/specialization/defaultimpl/validation.stderr

@@ -1,10 +1,10 @@
-error: inherent impls cannot be `default`
+error: inherent impls cannot be default
   --> $DIR/validation.rs:7:14
    |
 LL | default impl S {}
    | -------      ^ inherent impl for this type
    | |
-   | `default` because of this
+   | default because of this
    |
    = note: only trait implementations may be annotated with `default`
 

tests/ui/traits/const-traits/inherent-impl.rs

@@ -5,9 +5,9 @@
 trait T {}
 
 impl const S {}
-//~^ ERROR inherent impls cannot be `const`
+//~^ ERROR inherent impls cannot be const
 
 impl const dyn T {}
-//~^ ERROR inherent impls cannot be `const`
+//~^ ERROR inherent impls cannot be const
 
 fn main() {}

tests/ui/traits/const-traits/inherent-impl.stderr

@@ -1,20 +1,20 @@
-error: inherent impls cannot be `const`
+error: inherent impls cannot be const
   --> $DIR/inherent-impl.rs:7:12
    |
 LL | impl const S {}
    |      ----- ^ inherent impl for this type
    |      |
-   |      `const` because of this
+   |      const because of this
    |
    = note: only trait implementations may be annotated with `const`
 
-error: inherent impls cannot be `const`
+error: inherent impls cannot be const
   --> $DIR/inherent-impl.rs:10:12
    |
 LL | impl const dyn T {}
    |      ----- ^^^^^ inherent impl for this type
    |      |
-   |      `const` because of this
+   |      const because of this
    |
    = note: only trait implementations may be annotated with `const`
 

tests/ui/traits/const-traits/macro-const-trait-bound-theoretical-regression.stderr

@@ -1,4 +1,4 @@
-error: inherent impls cannot be `const`
+error: inherent impls cannot be const
   --> $DIR/macro-const-trait-bound-theoretical-regression.rs:10:40
    |
 LL |     (impl $c:ident Trait) => { impl $c Trait {} };
@@ -7,7 +7,7 @@ LL |     (impl $c:ident Trait) => { impl $c Trait {} };
 LL | demo! { impl const Trait }
    | --------------------------
    | |            |
-   | |            `const` because of this
+   | |            const because of this
    | in this macro invocation
    |
    = note: only trait implementations may be annotated with `const`

tests/ui/traits/const-traits/span-bug-issue-121418.rs

@@ -4,7 +4,7 @@
 trait T {}
 
 impl const dyn T {
-    //~^ ERROR inherent impls cannot be `const`
+    //~^ ERROR inherent impls cannot be const
     pub const fn new() -> std::sync::Mutex<dyn T> {}
     //~^ ERROR mismatched types
     //~| ERROR cannot be known at compilation time

tests/ui/traits/const-traits/span-bug-issue-121418.stderr

@@ -1,10 +1,10 @@
-error: inherent impls cannot be `const`
+error: inherent impls cannot be const
   --> $DIR/span-bug-issue-121418.rs:6:12
    |
 LL | impl const dyn T {
    |      ----- ^^^^^ inherent impl for this type
    |      |
-   |      `const` because of this
+   |      const because of this
    |
    = note: only trait implementations may be annotated with `const`
 

tests/ui/traits/safety-inherent-impl.stderr

@@ -6,7 +6,7 @@ LL | unsafe impl SomeStruct {
    | |
    | unsafe because of this
    |
-   = note: only trait implementations may be annotated with unsafe
+   = note: only trait implementations may be annotated with `unsafe`
 
 error: aborting due to 1 previous error
 

tests/ui/traits/syntax-trait-polarity.stderr

@@ -5,6 +5,8 @@ LL | impl !TestType {}
    |      -^^^^^^^^ inherent impl for this type
    |      |
    |      negative because of this
+   |
+   = note: only trait implementations may be annotated with `!`
 
 error: inherent impls cannot be negative
   --> $DIR/syntax-trait-polarity.rs:18:10
@@ -13,6 +15,8 @@ LL | impl<T> !TestType2<T> {}
    |         -^^^^^^^^^^^^ inherent impl for this type
    |         |
    |         negative because of this
+   |
+   = note: only trait implementations may be annotated with `!`
 
 error[E0198]: negative impls cannot be unsafe
   --> $DIR/syntax-trait-polarity.rs:12:13