Rollup merge of #106072 - eopb:dyn-derive, r=estebank

fix: misleading "add dyn keyword before derive macro" suggestion

Fixes #106071

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -3305,7 +3305,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
  let label = "add `dyn` keyword before this trait";
  let mut diag =
  rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg);
- diag.multipart_suggestion_verbose(label, sugg, Applicability::MachineApplicable);
+ if self_ty.span.can_be_used_for_suggestions() {
+ diag.multipart_suggestion_verbose(
+ label,
+ sugg,
+ Applicability::MachineApplicable,
+ );
+ }
  // check if the impl trait that we are considering is a impl of a local trait
  self.maybe_lint_blanket_trait_impl(&self_ty, &mut diag);
  diag.emit();

tests/ui/traits/issue-106072.rs

@@ -0,0 +1,5 @@
+#[derive(Clone)] //~ trait objects must include the `dyn` keyword
+ //~| trait objects must include the `dyn` keyword
+struct Foo;
+trait Foo {} //~ the name `Foo` is defined multiple times
+fn main() {}

tests/ui/traits/issue-106072.stderr

@@ -0,0 +1,30 @@
+error[E0428]: the name `Foo` is defined multiple times
+ --> $DIR/issue-106072.rs:4:1
+ |
+LL | struct Foo;
+ | ----------- previous definition of the type `Foo` here
+LL | trait Foo {}
+ | ^^^^^^^^^ `Foo` redefined here
+ |
+ = note: `Foo` must be defined only once in the type namespace of this module
+
+error[E0782]: trait objects must include the `dyn` keyword
+ --> $DIR/issue-106072.rs:1:10
+ |
+LL | #[derive(Clone)]
+ | ^^^^^
+ |
+ = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0782]: trait objects must include the `dyn` keyword
+ --> $DIR/issue-106072.rs:1:10
+ |
+LL | #[derive(Clone)]
+ | ^^^^^
+ |
+ = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0428, E0782.
+For more information about an error, try `rustc --explain E0428`.