diff options
| -rw-r--r-- | compiler/rustc_typeck/src/check/method/confirm.rs | 26 | ||||
| -rw-r--r-- | src/test/ui/methods/issues/issue-61525.rs | 20 | ||||
| -rw-r--r-- | src/test/ui/methods/issues/issue-61525.stderr | 39 |
3 files changed, 74 insertions, 11 deletions
diff --git a/compiler/rustc_typeck/src/check/method/confirm.rs b/compiler/rustc_typeck/src/check/method/confirm.rs index d8cdc9275f4..b14f3d6de4e 100644 --- a/compiler/rustc_typeck/src/check/method/confirm.rs +++ b/compiler/rustc_typeck/src/check/method/confirm.rs @@ -81,11 +81,25 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { let rcvr_substs = self.fresh_receiver_substs(self_ty, &pick); let all_substs = self.instantiate_method_substs(&pick, segment, rcvr_substs); - debug!("all_substs={:?}", all_substs); + debug!("rcvr_substs={rcvr_substs:?}, all_substs={all_substs:?}"); // Create the final signature for the method, replacing late-bound regions. let (method_sig, method_predicates) = self.instantiate_method_sig(&pick, all_substs); + // If there is a `Self: Sized` bound and `Self` is a trait object, it is possible that + // something which derefs to `Self` actually implements the trait and the caller + // wanted to make a static dispatch on it but forgot to import the trait. + // See test `src/test/ui/issue-35976.rs`. + // + // In that case, we'll error anyway, but we'll also re-run the search with all traits + // in scope, and if we find another method which can be used, we'll output an + // appropriate hint suggesting to import the trait. + let filler_substs = rcvr_substs + .extend_to(self.tcx, pick.item.def_id, |def, _| self.tcx.mk_param_from_def(def)); + let illegal_sized_bound = self.predicates_require_illegal_sized_bound( + &self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_substs), + ); + // Unify the (adjusted) self type with what the method expects. // // SUBTLE: if we want good error messages, because of "guessing" while matching @@ -106,16 +120,6 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { // Make sure nobody calls `drop()` explicitly. self.enforce_illegal_method_limitations(&pick); - // If there is a `Self: Sized` bound and `Self` is a trait object, it is possible that - // something which derefs to `Self` actually implements the trait and the caller - // wanted to make a static dispatch on it but forgot to import the trait. - // See test `src/test/ui/issue-35976.rs`. - // - // In that case, we'll error anyway, but we'll also re-run the search with all traits - // in scope, and if we find another method which can be used, we'll output an - // appropriate hint suggesting to import the trait. - let illegal_sized_bound = self.predicates_require_illegal_sized_bound(&method_predicates); - // Add any trait/regions obligations specified on the method's type parameters. // We won't add these if we encountered an illegal sized bound, so that we can use // a custom error in that case. diff --git a/src/test/ui/methods/issues/issue-61525.rs b/src/test/ui/methods/issues/issue-61525.rs new file mode 100644 index 00000000000..c5ca0326e43 --- /dev/null +++ b/src/test/ui/methods/issues/issue-61525.rs @@ -0,0 +1,20 @@ +pub trait Example { + fn query<Q>(self, q: Q); +} + +impl Example for i32 { + fn query<Q>(self, _: Q) { + unimplemented!() + } +} + +mod nested { + use super::Example; + fn example() { + 1.query::<dyn ToString>("") + //~^ ERROR the size for values of type `dyn ToString` cannot be known at compilation time + //~| ERROR mismatched types + } +} + +fn main() {} diff --git a/src/test/ui/methods/issues/issue-61525.stderr b/src/test/ui/methods/issues/issue-61525.stderr new file mode 100644 index 00000000000..aec968d7c44 --- /dev/null +++ b/src/test/ui/methods/issues/issue-61525.stderr @@ -0,0 +1,39 @@ +error[E0277]: the size for values of type `dyn ToString` cannot be known at compilation time + --> $DIR/issue-61525.rs:14:33 + | +LL | 1.query::<dyn ToString>("") + | ----- ^^ doesn't have a size known at compile-time + | | + | required by a bound introduced by this call + | + = help: the trait `Sized` is not implemented for `dyn ToString` +note: required by a bound in `Example::query` + --> $DIR/issue-61525.rs:2:14 + | +LL | fn query<Q>(self, q: Q); + | ^ required by this bound in `Example::query` +help: consider relaxing the implicit `Sized` restriction + | +LL | fn query<Q: ?Sized>(self, q: Q); + | ++++++++ + +error[E0308]: mismatched types + --> $DIR/issue-61525.rs:14:33 + | +LL | 1.query::<dyn ToString>("") + | --------------------- ^^ expected trait object `dyn ToString`, found `&str` + | | + | arguments to this function are incorrect + | + = note: expected trait object `dyn ToString` + found reference `&'static str` +note: associated function defined here + --> $DIR/issue-61525.rs:2:8 + | +LL | fn query<Q>(self, q: Q); + | ^^^^^ + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0277, E0308. +For more information about an error, try `rustc --explain E0277`. |