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 abb30d042ca4c..00e81ee049183 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 @@ -674,8 +674,11 @@ impl<'tcx> RegionInferenceContext<'tcx> { borrow_region: RegionVid, outlived_region: RegionVid, ) -> (ConstraintCategory, bool, Span, Option) { - let (category, from_closure, span) = - self.best_blame_constraint(mir, borrow_region, |r| r == outlived_region); + let (category, from_closure, span) = self.best_blame_constraint( + mir, + borrow_region, + |r| self.provides_universal_region(r, borrow_region, outlived_region) + ); let outlived_fr_name = self.give_region_a_name(infcx, mir, upvars, mir_def_id, outlived_region, &mut 1); (category, from_closure, span, outlived_fr_name) diff --git a/src/test/ui/nll/local-outlives-static-via-hrtb.rs b/src/test/ui/nll/local-outlives-static-via-hrtb.rs new file mode 100644 index 0000000000000..5f1f9b3a7f229 --- /dev/null +++ b/src/test/ui/nll/local-outlives-static-via-hrtb.rs @@ -0,0 +1,26 @@ +// Test that we handle the case when a local variable is borrowed for `'static` +// due to an outlives constraint involving a region in an incompatible universe + +pub trait Outlives<'this> {} + +impl<'this, T> Outlives<'this> for T where T: 'this {} +trait Reference { + type AssociatedType; +} + +impl<'a, T: 'a> Reference for &'a T { + type AssociatedType = &'a (); +} + +fn assert_static_via_hrtb(_: G) where for<'a> G: Outlives<'a> {} + +fn assert_static_via_hrtb_with_assoc_type(_: &'_ T) +where + for<'a> &'a T: Reference, +{} + +fn main() { + let local = 0; + assert_static_via_hrtb(&local); //~ ERROR `local` does not live long enough + assert_static_via_hrtb_with_assoc_type(&&local); //~ ERROR `local` does not live long enough +} diff --git a/src/test/ui/nll/local-outlives-static-via-hrtb.stderr b/src/test/ui/nll/local-outlives-static-via-hrtb.stderr new file mode 100644 index 0000000000000..61009da49ffed --- /dev/null +++ b/src/test/ui/nll/local-outlives-static-via-hrtb.stderr @@ -0,0 +1,26 @@ +error[E0597]: `local` does not live long enough + --> $DIR/local-outlives-static-via-hrtb.rs:24:28 + | +LL | assert_static_via_hrtb(&local); + | -----------------------^^^^^^- + | | | + | | borrowed value does not live long enough + | argument requires that `local` is borrowed for `'static` +LL | assert_static_via_hrtb_with_assoc_type(&&local); +LL | } + | - `local` dropped here while still borrowed + +error[E0597]: `local` does not live long enough + --> $DIR/local-outlives-static-via-hrtb.rs:25:45 + | +LL | assert_static_via_hrtb_with_assoc_type(&&local); + | ----------------------------------------^^^^^^- + | | | + | | borrowed value does not live long enough + | argument requires that `local` is borrowed for `'static` +LL | } + | - `local` dropped here while still borrowed + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0597`.