diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs index 98417e8c7a3f4..f536ec5d7c685 100644 --- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs @@ -10,6 +10,7 @@ use rustc_middle::ty::{self, Ty}; use rustc_mir_dataflow::move_paths::{LookupResult, MovePathIndex}; use rustc_span::{BytePos, ExpnKind, MacroKind, Span}; use rustc_trait_selection::error_reporting::traits::FindExprBySpan; +use rustc_trait_selection::infer::InferCtxtExt; use tracing::debug; use crate::MirBorrowckCtxt; @@ -267,6 +268,15 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { kind, self.is_upvar_field_projection(original_path.as_ref()) ); + if self.has_ambiguous_copy(original_path.ty(self.body, self.infcx.tcx).ty) { + // If the type may implement Copy, skip the error. + // It's an error with the Copy implementation (e.g. duplicate Copy) rather than borrow check + self.span_delayed_bug( + span, + "Type may implement copy, but there is no other error.", + ); + return; + } ( match kind { &IllegalMoveOriginKind::BorrowedContent { target_place } => self @@ -291,6 +301,13 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { self.buffer_error(err); } + fn has_ambiguous_copy(&mut self, ty: Ty<'tcx>) -> bool { + let Some(copy_trait_def) = self.infcx.tcx.lang_items().copy_trait() else { return false }; + // This is only going to be ambiguous if there are incoherent impls, because otherwise + // ambiguity should never happen in MIR. + self.infcx.type_implements_trait(copy_trait_def, [ty], self.param_env).may_apply() + } + fn report_cannot_move_from_static(&mut self, place: Place<'tcx>, span: Span) -> Diag<'infcx> { let description = if place.projection.len() == 1 { format!("static item {}", self.describe_any_place(place.as_ref())) diff --git a/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.rs b/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.rs new file mode 100644 index 0000000000000..3ea2c3ababe0f --- /dev/null +++ b/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.rs @@ -0,0 +1,10 @@ +// Duplicate implementations of Copy/Clone should not trigger +// borrow check warnings +// See #131083 + +#[derive(Copy, Clone)] +#[derive(Copy, Clone)] +//~^ ERROR conflicting implementations of trait `Copy` +enum E {} + +fn main() {} diff --git a/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.stderr b/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.stderr new file mode 100644 index 0000000000000..799391461daed --- /dev/null +++ b/tests/ui/derives/duplicate-derive-copy-clone-diagnostics.stderr @@ -0,0 +1,23 @@ +error[E0119]: conflicting implementations of trait `Copy` for type `E` + --> $DIR/duplicate-derive-copy-clone-diagnostics.rs:2:10 + | +LL | #[derive(Copy, Clone)] + | ---- first implementation here +LL | #[derive(Copy, Clone)] + | ^^^^ conflicting implementation for `E` + | + = note: this error originates in the derive macro `Copy` (in Nightly builds, run with -Z macro-backtrace for more info) + +error[E0119]: conflicting implementations of trait `Clone` for type `E` + --> $DIR/duplicate-derive-copy-clone-diagnostics.rs:2:16 + | +LL | #[derive(Copy, Clone)] + | ----- first implementation here +LL | #[derive(Copy, Clone)] + | ^^^^^ conflicting implementation for `E` + | + = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info) + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0119`.