diff --git a/compiler/rustc_typeck/src/check/closure.rs b/compiler/rustc_typeck/src/check/closure.rs index c3deab0938d3b..d4336563b9603 100644 --- a/compiler/rustc_typeck/src/check/closure.rs +++ b/compiler/rustc_typeck/src/check/closure.rs @@ -259,7 +259,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// The `cause_span` should be the span that caused us to /// have this expected signature, or `None` if we can't readily /// know that. - #[instrument(level = "debug", skip(self, cause_span))] fn deduce_sig_from_projection( &self, cause_span: Option, @@ -267,13 +266,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ) -> Option> { let tcx = self.tcx; + debug!("deduce_sig_from_projection({:?})", projection); + let trait_def_id = projection.trait_def_id(tcx); let is_fn = tcx.fn_trait_kind_from_lang_item(trait_def_id).is_some(); let gen_trait = tcx.require_lang_item(LangItem::Generator, cause_span); let is_gen = gen_trait == trait_def_id; if !is_fn && !is_gen { - debug!("not fn or generator"); + debug!("deduce_sig_from_projection: not fn or generator"); return None; } @@ -282,7 +283,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // associated item and not yield. let return_assoc_item = self.tcx.associated_item_def_ids(gen_trait)[1]; if return_assoc_item != projection.projection_def_id() { - debug!("not return assoc item of generator"); + debug!("deduce_sig_from_projection: not return assoc item of generator"); return None; } } @@ -290,7 +291,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let input_tys = if is_fn { let arg_param_ty = projection.skip_binder().projection_ty.substs.type_at(1); let arg_param_ty = self.resolve_vars_if_possible(arg_param_ty); - debug!(?arg_param_ty); + debug!("deduce_sig_from_projection: arg_param_ty={:?}", arg_param_ty); match arg_param_ty.kind() { ty::Tuple(tys) => tys.into_iter().map(|k| k.expect_ty()).collect::>(), @@ -305,7 +306,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Since this is a return parameter type it is safe to unwrap. let ret_param_ty = projection.skip_binder().term.ty().unwrap(); let ret_param_ty = self.resolve_vars_if_possible(ret_param_ty); - debug!(?ret_param_ty); + debug!("deduce_sig_from_projection: ret_param_ty={:?}", ret_param_ty); let sig = projection.rebind(self.tcx.mk_fn_sig( input_tys.iter(), @@ -314,7 +315,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { hir::Unsafety::Normal, Abi::Rust, )); - debug!(?sig); + debug!("deduce_sig_from_projection: sig={:?}", sig); Some(ExpectedSig { cause_span, sig }) } diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs index 52db15b69a375..e60893a658b3d 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs @@ -730,32 +730,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ) -> Vec> { let formal_ret = self.resolve_vars_with_obligations(formal_ret); let ret_ty = match expected_ret.only_has_type(self) { - Some(ret) => { - // HACK(oli-obk): This is a backwards compatibility hack. Without it, the inference - // variable will get instantiated with the opaque type. The inference variable often - // has various helpful obligations registered for it that help closures figure out their - // signature. If we infer the inference var to the opaque type, the closure won't be able - // to find those obligations anymore, and it can't necessarily find them from the opaque - // type itself. We could be more powerful with inference if we *combined* the obligations - // so that we got both the obligations from the opaque type and the ones from the inference - // variable. That will accept more code than we do right now, so we need to carefully consider - // the implications. - // Note: this check is pessimistic, as the inference type could be matched with something other - // than the opaque type, but then we need a new `TypeRelation` just for this specific case and - // can't re-use `sup` below. - if formal_ret.has_infer_types() { - for ty in ret.walk() { - if let ty::subst::GenericArgKind::Type(ty) = ty.unpack() { - if let ty::Opaque(def_id, _) = *ty.kind() { - if self.infcx.opaque_type_origin(def_id, DUMMY_SP).is_some() { - return Vec::new(); - } - } - } - } - } - ret - } + Some(ret) => ret, None => return Vec::new(), }; let expect_args = self diff --git a/src/test/ui/impl-trait/hidden-type-is-opaque-2.rs b/src/test/ui/impl-trait/hidden-type-is-opaque-2.rs deleted file mode 100644 index 1b65685a6c06f..0000000000000 --- a/src/test/ui/impl-trait/hidden-type-is-opaque-2.rs +++ /dev/null @@ -1,34 +0,0 @@ -// This doesn't work, because we don't flow information from opaque types -// into function arguments via the function's generic parameters -// FIXME(oli-obk): make `expected_inputs_for_expected_output` support this - -fn reify_as() -> Thunk Continuation> { - Thunk::new(|mut cont| { //~ ERROR type annotations needed - cont.reify_as(); - cont - }) -} - -#[must_use] -struct Thunk(F); - -impl Thunk { - fn new(f: F) -> Self - where - F: ContFn, - { - Thunk(f) - } -} - -trait ContFn {} - -impl Continuation> ContFn for F {} - -struct Continuation; - -impl Continuation { - fn reify_as(&mut self) {} -} - -fn main() {} diff --git a/src/test/ui/impl-trait/hidden-type-is-opaque-2.stderr b/src/test/ui/impl-trait/hidden-type-is-opaque-2.stderr deleted file mode 100644 index e538aaeb4c5ed..0000000000000 --- a/src/test/ui/impl-trait/hidden-type-is-opaque-2.stderr +++ /dev/null @@ -1,11 +0,0 @@ -error[E0282]: type annotations needed - --> $DIR/hidden-type-is-opaque-2.rs:6:17 - | -LL | Thunk::new(|mut cont| { - | ^^^^^^^^ consider giving this closure parameter a type - | - = note: type must be known at this point - -error: aborting due to previous error - -For more information about this error, try `rustc --explain E0282`. diff --git a/src/test/ui/impl-trait/hidden-type-is-opaque.rs b/src/test/ui/impl-trait/hidden-type-is-opaque.rs deleted file mode 100644 index b302ae36ef42c..0000000000000 --- a/src/test/ui/impl-trait/hidden-type-is-opaque.rs +++ /dev/null @@ -1,32 +0,0 @@ -// check-pass - -fn reify_as() -> Thunk { - Thunk::new(|mut cont| { - cont.reify_as(); - cont - }) -} - -#[must_use] -struct Thunk(F); - -impl Thunk { - fn new(f: F) -> Self - where - F: FnOnce(Continuation) -> Continuation, - { - Thunk(f) - } -} - -trait ContFn {} - -impl Continuation> ContFn for F {} - -struct Continuation; - -impl Continuation { - fn reify_as(&mut self) {} -} - -fn main() {} diff --git a/src/test/ui/impl-trait/issues/issue-70877.rs b/src/test/ui/impl-trait/issues/issue-70877.rs index 1a86fa00ed1a0..8169cfafac711 100644 --- a/src/test/ui/impl-trait/issues/issue-70877.rs +++ b/src/test/ui/impl-trait/issues/issue-70877.rs @@ -13,7 +13,7 @@ impl Iterator for Bar { type Item = FooItem; fn next(&mut self) -> Option { - Some(Box::new(quux)) //~ ERROR mismatched types + Some(Box::new(quux)) } } diff --git a/src/test/ui/impl-trait/issues/issue-70877.stderr b/src/test/ui/impl-trait/issues/issue-70877.stderr index 7cbd58bdabf2f..8813bff3c353e 100644 --- a/src/test/ui/impl-trait/issues/issue-70877.stderr +++ b/src/test/ui/impl-trait/issues/issue-70877.stderr @@ -1,17 +1,3 @@ -error[E0308]: mismatched types - --> $DIR/issue-70877.rs:16:9 - | -LL | type FooRet = impl std::fmt::Debug; - | -------------------- the expected opaque type -... -LL | fn next(&mut self) -> Option { - | ------------------ expected `Option Fn(&'r (dyn ToString + 'r)) -> FooRet + 'static)>>` because of return type -LL | Some(Box::new(quux)) - | ^^^^^^^^^^^^^^^^^^^^ expected trait object `dyn Fn`, found fn item - | - = note: expected enum `Option Fn(&'r (dyn ToString + 'r)) -> FooRet + 'static)>>` - found enum `Option fn(&'r (dyn ToString + 'r)) -> FooRet {quux}>>` - error: opaque type's hidden type cannot be another opaque type from the same scope --> $DIR/issue-70877.rs:31:12 | @@ -29,6 +15,5 @@ note: opaque type being used as hidden type LL | type FooRet = impl std::fmt::Debug; | ^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 2 previous errors +error: aborting due to previous error -For more information about this error, try `rustc --explain E0308`.