diff options
| -rw-r--r-- | compiler/rustc_hir_typeck/src/coercion.rs | 38 | ||||
| -rw-r--r-- | tests/ui/structs/struct-path-self-type-mismatch.stderr | 4 |
2 files changed, 41 insertions, 1 deletions
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs index 6c03bc3b57a..58f4e07e944 100644 --- a/compiler/rustc_hir_typeck/src/coercion.rs +++ b/compiler/rustc_hir_typeck/src/coercion.rs @@ -1738,6 +1738,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> { // label pointing out the cause for the type coercion will be wrong // as prior return coercions would not be relevant (#57664). let fn_decl = if let (Some(expr), Some(blk_id)) = (expression, blk_id) { + self.explain_self_literal(fcx, &mut err, expr); let pointing_at_return_type = fcx.suggest_mismatched_types_on_tail(&mut err, expr, expected, found, blk_id); if let (Some(cond_expr), true, false) = ( @@ -1810,6 +1811,43 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> { err } + fn explain_self_literal( + &self, + fcx: &FnCtxt<'_, 'tcx>, + err: &mut Diagnostic, + expr: &'tcx hir::Expr<'tcx>, + ) { + match expr.peel_drop_temps().kind { + hir::ExprKind::Struct( + hir::QPath::Resolved( + None, + hir::Path { res: hir::def::Res::SelfTyAlias { alias_to, .. }, .. }, + ), + .., + ) + | hir::ExprKind::Call( + hir::Expr { + kind: + hir::ExprKind::Path(hir::QPath::Resolved( + None, + hir::Path { res: hir::def::Res::SelfTyAlias { alias_to, .. }, .. }, + )), + .. + }, + .., + ) => { + if let Some(hir::Node::Item(hir::Item { + kind: hir::ItemKind::Impl(hir::Impl { self_ty, .. }), + .. + })) = fcx.tcx.hir().get_if_local(*alias_to) + { + err.span_label(self_ty.span, "this is the type of the `Self` literal"); + } + } + _ => {} + } + } + /// Checks whether the return type is unsized via an obligation, which makes /// sure we consider `dyn Trait: Sized` where clauses, which are trivially /// false but technically valid for typeck. diff --git a/tests/ui/structs/struct-path-self-type-mismatch.stderr b/tests/ui/structs/struct-path-self-type-mismatch.stderr index cddc1356194..f4ca4851083 100644 --- a/tests/ui/structs/struct-path-self-type-mismatch.stderr +++ b/tests/ui/structs/struct-path-self-type-mismatch.stderr @@ -24,7 +24,9 @@ error[E0308]: mismatched types --> $DIR/struct-path-self-type-mismatch.rs:13:9 | LL | impl<T> Foo<T> { - | - found type parameter + | - ------ this is the type of the `Self` literal + | | + | found type parameter LL | fn new<U>(u: U) -> Foo<U> { | - ------ expected `Foo<U>` because of return type | | |