diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs index f8843b892db..2bf582dcfb1 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs @@ -466,7 +466,6 @@ fn suggest_dereferences( && let Some(arg_ty) = typeck_results.expr_ty_adjusted_opt(expr) { // Suggest dereferencing the argument to a function/method call if possible - let mut real_trait_pred = trait_pred; while let Some((parent_code, parent_trait_pred)) = code.parent() { code = parent_code; @@ -553,6 +552,9 @@ fn suggest_dereferences( ); if self.predicate_may_hold(&obligation) && self.predicate_must_hold_modulo_regions(&sized_obligation) + // Do not suggest * if it is already a reference, + // will suggest removing the borrow instead in that case. + && !matches!(expr.kind, hir::ExprKind::AddrOf(..)) { let call_node = self.tcx.hir_node(*call_hir_id); let msg = "consider dereferencing here"; diff --git a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs new file mode 100644 index 00000000000..a71657316ae --- /dev/null +++ b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs @@ -0,0 +1,18 @@ +fn main() { + let fields = vec![1]; + let variant = vec![2]; + + // should not suggest `*&variant.iter()` + for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) { + //~^ ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator + //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator + eprintln!("{} {}", src, dest); + } + + // don't suggest add `variant.iter().clone().clone()` + for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) { + //~^ ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator + //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator + eprintln!("{} {}", src, dest); + } +} diff --git a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr new file mode 100644 index 00000000000..a3ed51ace08 --- /dev/null +++ b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr @@ -0,0 +1,61 @@ +error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator + --> $DIR/invalid-suggest-deref-issue-127590.rs:6:54 + | +LL | for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) { + | -------------- ^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator + | | + | required by a bound introduced by this call + | + = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`, which is required by `&std::slice::Iter<'_, {integer}>: IntoIterator` + = note: required for `&std::slice::Iter<'_, {integer}>` to implement `IntoIterator` +note: required by a bound in `std::iter::zip` + --> $SRC_DIR/core/src/iter/adapters/zip.rs:LL:COL +help: consider removing the leading `&`-reference + | +LL - for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) { +LL + for (src, dest) in std::iter::zip(fields.iter(), variant.iter()) { + | + +error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator + --> $DIR/invalid-suggest-deref-issue-127590.rs:6:24 + | +LL | for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator + | + = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`, which is required by `Zip, &std::slice::Iter<'_, {integer}>>: IntoIterator` + = help: the trait `Iterator` is implemented for `std::slice::Iter<'a, T>` + = note: required for `Zip, &std::slice::Iter<'_, {integer}>>` to implement `Iterator` + = note: required for `Zip, &std::slice::Iter<'_, {integer}>>` to implement `IntoIterator` + +error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator + --> $DIR/invalid-suggest-deref-issue-127590.rs:13:54 + | +LL | for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) { + | -------------- ^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator + | | + | required by a bound introduced by this call + | + = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`, which is required by `&std::slice::Iter<'_, {integer}>: IntoIterator` + = note: required for `&std::slice::Iter<'_, {integer}>` to implement `IntoIterator` +note: required by a bound in `std::iter::zip` + --> $SRC_DIR/core/src/iter/adapters/zip.rs:LL:COL +help: consider removing the leading `&`-reference + | +LL - for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) { +LL + for (src, dest) in std::iter::zip(fields.iter(), variant.iter().clone()) { + | + +error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator + --> $DIR/invalid-suggest-deref-issue-127590.rs:13:24 + | +LL | for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator + | + = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`, which is required by `Zip, &std::slice::Iter<'_, {integer}>>: IntoIterator` + = help: the trait `Iterator` is implemented for `std::slice::Iter<'a, T>` + = note: required for `Zip, &std::slice::Iter<'_, {integer}>>` to implement `Iterator` + = note: required for `Zip, &std::slice::Iter<'_, {integer}>>` to implement `IntoIterator` + +error: aborting due to 4 previous errors + +For more information about this error, try `rustc --explain E0277`.