diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs index 06a7a6bb301de..ac8173f101a65 100644 --- a/src/librustc/hir/lowering.rs +++ b/src/librustc/hir/lowering.rs @@ -2170,6 +2170,16 @@ impl<'a> LoweringContext<'a> { impl_trait_return_allow: bool, make_ret_async: Option, ) -> P { + debug!("lower_fn_decl(\ + fn_decl: {:?}, \ + in_band_ty_params: {:?}, \ + impl_trait_return_allow: {}, \ + make_ret_async: {:?})", + decl, + in_band_ty_params, + impl_trait_return_allow, + make_ret_async, + ); let lt_mode = if make_ret_async.is_some() { // In `async fn`, argument-position elided lifetimes // must be transformed into fresh generic parameters so that @@ -2462,7 +2472,7 @@ impl<'a> LoweringContext<'a> { hir::FunctionRetTy::Return(P(hir::Ty { kind: opaque_ty_ref, - span, + span: opaque_ty_span, hir_id: self.next_id(), })) } @@ -2572,7 +2582,7 @@ impl<'a> LoweringContext<'a> { hir::Lifetime { hir_id: self.lower_node_id(id), span, - name: name, + name, } } diff --git a/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs b/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs index d7cba87e6b132..a431b541fa42f 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs @@ -45,7 +45,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> { /// /// It will later be extended to trait objects. pub(super) fn try_report_anon_anon_conflict(&self) -> Option { - let (span, sub, sup) = self.get_regions(); + let (span, sub, sup) = self.regions(); // Determine whether the sub and sup consist of both anonymous (elided) regions. let anon_reg_sup = self.tcx().is_suitable_region(sup)?; diff --git a/src/librustc/infer/error_reporting/nice_region_error/mod.rs b/src/librustc/infer/error_reporting/nice_region_error/mod.rs index cd003aa8dab70..09cfbf850a57d 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/mod.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/mod.rs @@ -77,7 +77,7 @@ impl<'cx, 'tcx> NiceRegionError<'cx, 'tcx> { .or_else(|| self.try_report_impl_not_conforming_to_trait()) } - pub fn get_regions(&self) -> (Span, ty::Region<'tcx>, ty::Region<'tcx>) { + pub fn regions(&self) -> (Span, ty::Region<'tcx>, ty::Region<'tcx>) { match (&self.error, self.regions) { (Some(ConcreteFailure(origin, sub, sup)), None) => (origin.span(), sub, sup), (Some(SubSupConflict(_, _, origin, sub, _, sup)), None) => (origin.span(), sub, sup), diff --git a/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs b/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs index 3613184919164..0abdeb7199344 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/named_anon_conflict.rs @@ -11,7 +11,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> { /// When given a `ConcreteFailure` for a function with parameters containing a named region and /// an anonymous region, emit an descriptive diagnostic error. pub(super) fn try_report_named_anon_conflict(&self) -> Option> { - let (span, sub, sup) = self.get_regions(); + let (span, sub, sup) = self.regions(); debug!( "try_report_named_anon_conflict(sub={:?}, sup={:?}, error={:?})", diff --git a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs index 9d405d4ea40c9..01ba748c4e1f9 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs @@ -20,8 +20,9 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> { ) = error.clone() { let anon_reg_sup = self.tcx().is_suitable_region(sup_r)?; + let return_ty = self.tcx().return_type_impl_trait(anon_reg_sup.def_id); if sub_r == &RegionKind::ReStatic && - self.tcx().return_type_impl_trait(anon_reg_sup.def_id).is_some() + return_ty.is_some() { let sp = var_origin.span(); let return_sp = sub_origin.span(); @@ -52,17 +53,23 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> { }) => name.to_string(), _ => "'_".to_owned(), }; - if let Ok(snippet) = self.tcx().sess.source_map().span_to_snippet(return_sp) { - err.span_suggestion( - return_sp, - &format!( - "you can add a constraint to the return type to make it last \ + let fn_return_span = return_ty.unwrap().1; + if let Ok(snippet) = + self.tcx().sess.source_map().span_to_snippet(fn_return_span) { + // only apply this suggestion onto functions with + // explicit non-desugar'able return. + if fn_return_span.desugaring_kind().is_none() { + err.span_suggestion( + fn_return_span, + &format!( + "you can add a constraint to the return type to make it last \ less than `'static` and match {}", - lifetime, - ), - format!("{} + {}", snippet, lifetime_name), - Applicability::Unspecified, - ); + lifetime, + ), + format!("{} + {}", snippet, lifetime_name), + Applicability::Unspecified, + ); + } } err.emit(); return Some(ErrorReported); diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs index 41d069bf6ae33..fec0c8bb9223b 100644 --- a/src/librustc/ty/context.rs +++ b/src/librustc/ty/context.rs @@ -1529,14 +1529,14 @@ impl<'tcx> TyCtxt<'tcx> { return Some(FreeRegionInfo { def_id: suitable_region_binding_scope, boundregion: bound_region, - is_impl_item: is_impl_item, + is_impl_item, }); } pub fn return_type_impl_trait( &self, scope_def_id: DefId, - ) -> Option> { + ) -> Option<(Ty<'tcx>, Span)> { // HACK: `type_of_def_id()` will fail on these (#55796), so return `None`. let hir_id = self.hir().as_local_hir_id(scope_def_id).unwrap(); match self.hir().get(hir_id) { @@ -1557,7 +1557,8 @@ impl<'tcx> TyCtxt<'tcx> { let sig = ret_ty.fn_sig(*self); let output = self.erase_late_bound_regions(&sig.output()); if output.is_impl_trait() { - Some(output) + let fn_decl = self.hir().fn_decl_by_hir_id(hir_id).unwrap(); + Some((output, fn_decl.output.span())) } else { None } diff --git a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs index 26b288cb4b24e..e6795dbfd449c 100644 --- a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs +++ b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs @@ -715,10 +715,10 @@ impl<'tcx> RegionInferenceContext<'tcx> { if let (Some(f), Some(ty::RegionKind::ReStatic)) = (self.to_error_region(fr), self.to_error_region(outlived_fr)) { - if let Some(ty::TyS { + if let Some((ty::TyS { kind: ty::Opaque(did, substs), .. - }) = infcx + }, _)) = infcx .tcx .is_suitable_region(f) .map(|r| r.def_id) diff --git a/src/test/ui/async-await/issues/issue-62097.nll.stderr b/src/test/ui/async-await/issues/issue-62097.nll.stderr new file mode 100644 index 0000000000000..0c64f90cb9fae --- /dev/null +++ b/src/test/ui/async-await/issues/issue-62097.nll.stderr @@ -0,0 +1,29 @@ +error[E0373]: closure may outlive the current function, but it borrows `self`, which is owned by the current function + --> $DIR/issue-62097.rs:13:13 + | +LL | foo(|| self.bar()).await; + | ^^ ---- `self` is borrowed here + | | + | may outlive borrowed value `self` + | +note: function requires argument type to outlive `'static` + --> $DIR/issue-62097.rs:13:9 + | +LL | foo(|| self.bar()).await; + | ^^^^^^^^^^^^^^^^^^ +help: to force the closure to take ownership of `self` (and any other referenced variables), use the `move` keyword + | +LL | foo(move || self.bar()).await; + | ^^^^^^^ + +error[E0521]: borrowed data escapes outside of function + --> $DIR/issue-62097.rs:13:9 + | +LL | pub async fn run_dummy_fn(&self) { + | ----- `self` is a reference that is only valid in the function body +LL | foo(|| self.bar()).await; + | ^^^^^^^^^^^^^^^^^^ `self` escapes the function body here + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0373`. diff --git a/src/test/ui/async-await/issues/issue-62097.rs b/src/test/ui/async-await/issues/issue-62097.rs new file mode 100644 index 0000000000000..ea482d3667e2b --- /dev/null +++ b/src/test/ui/async-await/issues/issue-62097.rs @@ -0,0 +1,19 @@ +// edition:2018 +async fn foo(fun: F) +where + F: FnOnce() + 'static +{ + fun() +} + +struct Struct; + +impl Struct { + pub async fn run_dummy_fn(&self) { //~ ERROR cannot infer + foo(|| self.bar()).await; + } + + pub fn bar(&self) {} +} + +fn main() {} diff --git a/src/test/ui/async-await/issues/issue-62097.stderr b/src/test/ui/async-await/issues/issue-62097.stderr new file mode 100644 index 0000000000000..94afccc06a9e7 --- /dev/null +++ b/src/test/ui/async-await/issues/issue-62097.stderr @@ -0,0 +1,16 @@ +error: cannot infer an appropriate lifetime + --> $DIR/issue-62097.rs:12:31 + | +LL | pub async fn run_dummy_fn(&self) { + | ^^^^^ ...but this borrow... +LL | foo(|| self.bar()).await; + | --- this return type evaluates to the `'static` lifetime... + | +note: ...can't outlive the lifetime `'_` as defined on the method body at 12:31 + --> $DIR/issue-62097.rs:12:31 + | +LL | pub async fn run_dummy_fn(&self) { + | ^ + +error: aborting due to previous error + diff --git a/src/test/ui/async-await/issues/issue-63388-2.stderr b/src/test/ui/async-await/issues/issue-63388-2.stderr index efec160588fc4..7e45d588c6c6c 100644 --- a/src/test/ui/async-await/issues/issue-63388-2.stderr +++ b/src/test/ui/async-await/issues/issue-63388-2.stderr @@ -20,10 +20,6 @@ note: ...can't outlive the lifetime `'_` as defined on the method body at 11:14 | LL | foo: &dyn Foo, bar: &'a dyn Foo | ^ -help: you can add a constraint to the return type to make it last less than `'static` and match the lifetime `'_` as defined on the method body at 11:14 - | -LL | foo + '_ - | error: aborting due to 2 previous errors diff --git a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr index bce1900ca602c..91075ffbdb605 100644 --- a/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr +++ b/src/test/ui/self/arbitrary_self_types_pin_lifetime_impl_trait-async.stderr @@ -11,10 +11,6 @@ note: ...can't outlive the lifetime `'_` as defined on the method body at 8:26 | LL | async fn f(self: Pin<&Self>) -> impl Clone { self } | ^ -help: you can add a constraint to the return type to make it last less than `'static` and match the lifetime `'_` as defined on the method body at 8:26 - | -LL | async fn f(self: Pin<&Self>) -> impl Clone + '_ { self } - | ^^^^^^^^^^^^^^^ error: aborting due to previous error