diff --git a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
index dd8a7f19a63..0fabcfe4564 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
@@ -1268,7 +1268,7 @@ pub trait ClosureRegionRequirementsExt<'gcx, 'tcx> {
tcx: TyCtxt<'_, 'gcx, 'tcx>,
location: Location,
closure_def_id: DefId,
- closure_substs: ty::ClosureSubsts<'tcx>,
+ closure_substs: &'tcx ty::subst::Substs<'tcx>,
) -> Vec<QueryRegionConstraint<'tcx>>;
fn subst_closure_mapping<T>(
@@ -1299,23 +1299,19 @@ impl<'gcx, 'tcx> ClosureRegionRequirementsExt<'gcx, 'tcx> for ClosureRegionRequi
tcx: TyCtxt<'_, 'gcx, 'tcx>,
location: Location,
closure_def_id: DefId,
- closure_substs: ty::ClosureSubsts<'tcx>,
+ closure_substs: &'tcx ty::subst::Substs<'tcx>,
) -> Vec<QueryRegionConstraint<'tcx>> {
debug!(
"apply_requirements(location={:?}, closure_def_id={:?}, closure_substs={:?})",
location, closure_def_id, closure_substs
);
- // Get Tu.
- let user_closure_ty = tcx.mk_closure(closure_def_id, closure_substs);
- debug!("apply_requirements: user_closure_ty={:?}", user_closure_ty);
-
- // Extract the values of the free regions in `user_closure_ty`
+ // Extract the values of the free regions in `closure_substs`
// into a vector. These are the regions that we will be
// relating to one another.
let closure_mapping = &UniversalRegions::closure_mapping(
tcx,
- user_closure_ty,
+ closure_substs,
self.num_external_vids,
tcx.closure_base_def_id(closure_def_id),
);
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index 1e79bc272e4..c5758cde949 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -42,7 +42,7 @@ use rustc::traits::query::type_op::custom::CustomTypeOp;
use rustc::traits::query::{Fallible, NoSolution};
use rustc::traits::{ObligationCause, PredicateObligations};
use rustc::ty::fold::TypeFoldable;
-use rustc::ty::subst::{Subst, UnpackedKind};
+use rustc::ty::subst::{Subst, Substs, UnpackedKind};
use rustc::ty::{self, RegionVid, ToPolyTraitRef, Ty, TyCtxt, TyKind};
use std::rc::Rc;
use std::{fmt, iter};
@@ -2075,12 +2075,9 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
// desugaring. A closure gets desugared to a struct, and
// these extra requirements are basically like where
// clauses on the struct.
- AggregateKind::Closure(def_id, substs) => {
- self.prove_closure_bounds(tcx, *def_id, *substs, location)
- }
-
- AggregateKind::Generator(def_id, substs, _) => {
- tcx.predicates_of(*def_id).instantiate(tcx, substs.substs)
+ AggregateKind::Closure(def_id, ty::ClosureSubsts { substs })
+ | AggregateKind::Generator(def_id, ty::GeneratorSubsts { substs }, _) => {
+ self.prove_closure_bounds(tcx, *def_id, substs, location)
}
AggregateKind::Array(_) | AggregateKind::Tuple => ty::InstantiatedPredicates::empty(),
@@ -2096,7 +2093,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
&mut self,
tcx: TyCtxt<'a, 'gcx, 'tcx>,
def_id: DefId,
- substs: ty::ClosureSubsts<'tcx>,
+ substs: &'tcx Substs<'tcx>,
location: Location,
) -> ty::InstantiatedPredicates<'tcx> {
if let Some(closure_region_requirements) =
@@ -2155,7 +2152,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
);
}
- tcx.predicates_of(def_id).instantiate(tcx, substs.substs)
+ tcx.predicates_of(def_id).instantiate(tcx, substs)
}
fn prove_trait_ref(
diff --git a/src/librustc_mir/borrow_check/nll/universal_regions.rs b/src/librustc_mir/borrow_check/nll/universal_regions.rs
index eb6f1a0677b..c54a4f96b7d 100644
--- a/src/librustc_mir/borrow_check/nll/universal_regions.rs
+++ b/src/librustc_mir/borrow_check/nll/universal_regions.rs
@@ -232,13 +232,13 @@ impl<'tcx> UniversalRegions<'tcx> {
/// `V[1]: V[2]`.
pub fn closure_mapping(
tcx: TyCtxt<'_, '_, 'tcx>,
- closure_ty: Ty<'tcx>,
+ closure_substs: &'tcx Substs<'tcx>,
expected_num_vars: usize,
closure_base_def_id: DefId,
) -> IndexVec<RegionVid, ty::Region<'tcx>> {
let mut region_mapping = IndexVec::with_capacity(expected_num_vars);
region_mapping.push(tcx.types.re_static);
- tcx.for_each_free_region(&closure_ty, |fr| {
+ tcx.for_each_free_region(&closure_substs, |fr| {
region_mapping.push(fr);
});
diff --git a/src/test/ui/generator/generator-region-requirements.ast.stderr b/src/test/ui/generator/generator-region-requirements.ast.stderr
new file mode 100644
index 00000000000..6a423aea7ec
--- /dev/null
+++ b/src/test/ui/generator/generator-region-requirements.ast.stderr
@@ -0,0 +1,12 @@
+error[E0621]: explicit lifetime required in the type of `x`
+ --> $DIR/generator-region-requirements.rs:15:51
+ |
+LL | fn dangle(x: &mut i32) -> &'static mut i32 {
+ | -------- help: add explicit lifetime `'static` to the type of `x`: `&'static mut i32`
+...
+LL | GeneratorState::Complete(c) => return c,
+ | ^ lifetime `'static` required
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0621`.
diff --git a/src/test/ui/generator/generator-region-requirements.nll.stderr b/src/test/ui/generator/generator-region-requirements.nll.stderr
new file mode 100644
index 00000000000..5d1050dc352
--- /dev/null
+++ b/src/test/ui/generator/generator-region-requirements.nll.stderr
@@ -0,0 +1,12 @@
+error[E0621]: explicit lifetime required in the type of `x`
+ --> $DIR/generator-region-requirements.rs:11:9
+ |
+LL | fn dangle(x: &mut i32) -> &'static mut i32 {
+ | -------- help: add explicit lifetime `'static` to the type of `x`: `&'static mut i32`
+...
+LL | x
+ | ^ lifetime `'static` required
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0621`.
diff --git a/src/test/ui/generator/generator-region-requirements.rs b/src/test/ui/generator/generator-region-requirements.rs
new file mode 100644
index 00000000000..59e7841309c
--- /dev/null
+++ b/src/test/ui/generator/generator-region-requirements.rs
@@ -0,0 +1,21 @@
+// revisions: ast nll
+// ignore-compare-mode-nll
+
+#![feature(generators, generator_trait)]
+#![cfg_attr(nll, feature(nll))]
+use std::ops::{Generator, GeneratorState};
+
+fn dangle(x: &mut i32) -> &'static mut i32 {
+ let mut g = || {
+ yield;
+ x
+ };
+ loop {
+ match unsafe { g.resume() } {
+ GeneratorState::Complete(c) => return c,
+ GeneratorState::Yielded(_) => (),
+ }
+ }
+}
+
+fn main() {}