Make diagnostics clearer for binop-related errors in foreign crates

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -2985,46 +2985,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         foreign_preds.sort_by_key(|pred: &&ty::TraitPredicate<'_>| pred.trait_ref.to_string());
-        let foreign_def_ids = foreign_preds
-            .iter()
-            .filter_map(|pred| match pred.self_ty().kind() {
-                ty::Adt(def, _) => Some(def.did()),
-                _ => None,
-            })
-            .collect::<FxIndexSet<_>>();
-        let mut foreign_spans: MultiSpan = foreign_def_ids
-            .iter()
-            .filter_map(|def_id| {
-                let span = self.tcx.def_span(*def_id);
-                if span.is_dummy() { None } else { Some(span) }
-            })
-            .collect::<Vec<_>>()
-            .into();
-        for pred in &foreign_preds {
-            if let ty::Adt(def, _) = pred.self_ty().kind() {
-                foreign_spans.push_span_label(
-                    self.tcx.def_span(def.did()),
-                    format!("not implement `{}`", pred.trait_ref.print_trait_sugared()),
-                );
+
+        for pred in foreign_preds {
+            let ty = pred.self_ty();
+            let ty::Adt(def, _) = ty.kind() else { continue };
+            let span = self.tcx.def_span(def.did());
+            if span.is_dummy() {
+                continue;
             }
-        }
-        if foreign_spans.primary_span().is_some() {
-            let msg = if let [foreign_pred] = foreign_preds.as_slice() {
-                format!(
-                    "the foreign item type `{}` doesn't implement `{}`",
-                    foreign_pred.self_ty(),
-                    foreign_pred.trait_ref.print_trait_sugared()
-                )
-            } else {
-                format!(
-                    "the foreign item type{} {} implement required trait{} for this \
-                     operation to be valid",
-                    pluralize!(foreign_def_ids.len()),
-                    if foreign_def_ids.len() > 1 { "don't" } else { "doesn't" },
-                    pluralize!(foreign_preds.len()),
-                )
-            };
-            err.span_note(foreign_spans, msg);
+            let mut mspan: MultiSpan = span.into();
+            mspan.push_span_label(span, format!("`{ty}` is defined in another crate"));
+            err.span_note(
+                mspan,
+                format!("`{ty}` does not implement `{}`", pred.trait_ref.print_trait_sugared()),
+            );
         }
 
         let preds: Vec<_> = errors

tests/ui/array-slice-vec/vec-res-add.stderr

@@ -6,10 +6,10 @@ LL |     let k = i + j;
    |             |
    |             Vec<R>
    |
-note: the foreign item type `Vec<R>` doesn't implement `Add`
+note: `Vec<R>` does not implement `Add`
   --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
    |
-   = note: not implement `Add`
+   = note: `Vec<R>` is defined in another crate
 
 error: aborting due to 1 previous error
 

tests/ui/autoref-autoderef/autoderef-box-no-add.stderr

@@ -6,11 +6,11 @@ LL |     let z: isize = a.x + b.y;
    |                    |
    |                    Box<isize>
    |
-note: the foreign item type `Box<isize>` doesn't implement `Add`
+note: `Box<isize>` does not implement `Add`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
   ::: $SRC_DIR/alloc/src/boxed.rs:LL:COL
    |
-   = note: not implement `Add`
+   = note: `Box<isize>` is defined in another crate
 
 error[E0369]: cannot add `Box<isize>` to `Box<isize>`
   --> $DIR/autoderef-box-no-add.rs:31:33
@@ -20,11 +20,11 @@ LL |     let answer: isize = forty.a + two.a;
    |                         |
    |                         Box<isize>
    |
-note: the foreign item type `Box<isize>` doesn't implement `Add`
+note: `Box<isize>` does not implement `Add`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
   ::: $SRC_DIR/alloc/src/boxed.rs:LL:COL
    |
-   = note: not implement `Add`
+   = note: `Box<isize>` is defined in another crate
 
 error: aborting due to 2 previous errors
 

tests/ui/binop/binary-op-not-allowed-issue-125631.stderr

@@ -11,10 +11,10 @@ note: an implementation of `PartialEq` might be missing for `T1`
    |
 LL | struct T1;
    | ^^^^^^^^^ must implement `PartialEq`
-note: the foreign item type `std::io::Error` doesn't implement `PartialEq`
+note: `std::io::Error` does not implement `PartialEq`
   --> $SRC_DIR/std/src/io/error.rs:LL:COL
    |
-   = note: not implement `PartialEq`
+   = note: `std::io::Error` is defined in another crate
 help: consider annotating `T1` with `#[derive(PartialEq)]`
    |
 LL + #[derive(PartialEq)]
@@ -29,13 +29,14 @@ LL |     (Error::new(ErrorKind::Other, "2"), thread::current())
 LL |         == (Error::new(ErrorKind::Other, "2"), thread::current());
    |         ^^ ------------------------------------------------------ (std::io::Error, Thread)
    |
-note: the foreign item types don't implement required traits for this operation to be valid
-  --> $SRC_DIR/std/src/io/error.rs:LL:COL
-   |
-   = note: not implement `PartialEq`
+note: `Thread` does not implement `PartialEq`
   --> $SRC_DIR/std/src/thread/mod.rs:LL:COL
    |
-   = note: not implement `PartialEq`
+   = note: `Thread` is defined in another crate
+note: `std::io::Error` does not implement `PartialEq`
+  --> $SRC_DIR/std/src/io/error.rs:LL:COL
+   |
+   = note: `std::io::Error` is defined in another crate
 
 error[E0369]: binary operation `==` cannot be applied to type `(std::io::Error, Thread, T1, T2)`
   --> $DIR/binary-op-not-allowed-issue-125631.rs:14:9
@@ -52,13 +53,14 @@ LL | struct T1;
    | ^^^^^^^^^ must implement `PartialEq`
 LL | struct T2;
    | ^^^^^^^^^ must implement `PartialEq`
-note: the foreign item types don't implement required traits for this operation to be valid
-  --> $SRC_DIR/std/src/io/error.rs:LL:COL
-   |
-   = note: not implement `PartialEq`
+note: `Thread` does not implement `PartialEq`
   --> $SRC_DIR/std/src/thread/mod.rs:LL:COL
    |
-   = note: not implement `PartialEq`
+   = note: `Thread` is defined in another crate
+note: `std::io::Error` does not implement `PartialEq`
+  --> $SRC_DIR/std/src/io/error.rs:LL:COL
+   |
+   = note: `std::io::Error` is defined in another crate
 help: consider annotating `T1` with `#[derive(PartialEq)]`
    |
 LL + #[derive(PartialEq)]

tests/ui/binop/binop-bitxor-str.stderr

@@ -6,10 +6,10 @@ LL | fn main() { let x = "a".to_string() ^ "b".to_string(); }
    |                     |
    |                     String
    |
-note: the foreign item type `String` doesn't implement `BitXor`
+note: `String` does not implement `BitXor`
   --> $SRC_DIR/alloc/src/string.rs:LL:COL
    |
-   = note: not implement `BitXor`
+   = note: `String` is defined in another crate
 
 error: aborting due to 1 previous error
 

tests/ui/error-codes/E0067.stderr

@@ -6,11 +6,11 @@ LL |     LinkedList::new() += 1;
    |     |
    |     cannot use `+=` on type `LinkedList<_>`
    |
-note: the foreign item type `LinkedList<_>` doesn't implement `AddAssign<{integer}>`
+note: `LinkedList<_>` does not implement `AddAssign<{integer}>`
   --> $SRC_DIR/alloc/src/collections/linked_list.rs:LL:COL
   ::: $SRC_DIR/alloc/src/collections/linked_list.rs:LL:COL
    |
-   = note: not implement `AddAssign<{integer}>`
+   = note: `LinkedList<_>` is defined in another crate
 
 error[E0067]: invalid left-hand side of assignment
   --> $DIR/E0067.rs:4:23

tests/ui/operator-recovery/box-arithmetic-14915.stderr

@@ -6,11 +6,11 @@ LL |     println!("{}", x + 1);
    |                    |
    |                    Box<isize>
    |
-note: the foreign item type `Box<isize>` doesn't implement `Add<{integer}>`
+note: `Box<isize>` does not implement `Add<{integer}>`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
   ::: $SRC_DIR/alloc/src/boxed.rs:LL:COL
    |
-   = note: not implement `Add<{integer}>`
+   = note: `Box<isize>` is defined in another crate
 
 error: aborting due to 1 previous error
 

tests/ui/pattern/pattern-tyvar-2.stderr

@@ -6,10 +6,10 @@ LL | fn foo(t: Bar) -> isize { match t { Bar::T1(_, Some(x)) => { return x * 3;
    |                                                                     |
    |                                                                     Vec<isize>
    |
-note: the foreign item type `Vec<isize>` doesn't implement `Mul<{integer}>`
+note: `Vec<isize>` does not implement `Mul<{integer}>`
   --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
    |
-   = note: not implement `Mul<{integer}>`
+   = note: `Vec<isize>` is defined in another crate
 
 error: aborting due to 1 previous error
 

tests/ui/typeck/assign-non-lval-derefmut.stderr

@@ -19,10 +19,10 @@ LL |     x.lock().unwrap() += 1;
    |     |
    |     cannot use `+=` on type `std::sync::MutexGuard<'_, usize>`
    |
-note: the foreign item type `std::sync::MutexGuard<'_, usize>` doesn't implement `AddAssign<{integer}>`
+note: `std::sync::MutexGuard<'_, usize>` does not implement `AddAssign<{integer}>`
   --> $SRC_DIR/std/src/sync/poison/mutex.rs:LL:COL
    |
-   = note: not implement `AddAssign<{integer}>`
+   = note: `std::sync::MutexGuard<'_, usize>` is defined in another crate
 help: `+=` can be used on `usize` if you dereference the left-hand side
    |
 LL |     *x.lock().unwrap() += 1;
@@ -51,10 +51,10 @@ LL |     y += 1;
    |     |
    |     cannot use `+=` on type `std::sync::MutexGuard<'_, usize>`
    |
-note: the foreign item type `std::sync::MutexGuard<'_, usize>` doesn't implement `AddAssign<{integer}>`
+note: `std::sync::MutexGuard<'_, usize>` does not implement `AddAssign<{integer}>`
   --> $SRC_DIR/std/src/sync/poison/mutex.rs:LL:COL
    |
-   = note: not implement `AddAssign<{integer}>`
+   = note: `std::sync::MutexGuard<'_, usize>` is defined in another crate
 help: `+=` can be used on `usize` if you dereference the left-hand side
    |
 LL |     *y += 1;

tests/ui/typeck/minus-string.stderr

@@ -4,10 +4,10 @@ error[E0600]: cannot apply unary operator `-` to type `String`
 LL |     -"foo".to_string();
    |     ^^^^^^^^^^^^^^^^^^ cannot apply unary operator `-`
    |
-note: the foreign item type `String` doesn't implement `Neg`
+note: `String` does not implement `Neg`
   --> $SRC_DIR/alloc/src/string.rs:LL:COL
    |
-   = note: not implement `Neg`
+   = note: `String` is defined in another crate
 
 error: aborting due to 1 previous error