diff --git a/src/librustc_mir/borrow_check/nll/mod.rs b/src/librustc_mir/borrow_check/nll/mod.rs
index 693210da8d3a8..7cab0acb4326a 100644
--- a/src/librustc_mir/borrow_check/nll/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/mod.rs
@@ -276,7 +276,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
infcx: &InferCtxt<'a, 'gcx, 'tcx>,
mir: &Mir<'tcx>,
mir_def_id: DefId,
- regioncx: &RegionInferenceContext,
+ regioncx: &RegionInferenceContext<'tcx>,
closure_region_requirements: &Option<ClosureRegionRequirements>,
errors_buffer: &mut Vec<Diagnostic>,
) {
@@ -299,7 +299,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
.diagnostic()
.span_note_diag(mir.span, "External requirements");
- regioncx.annotate(&mut err);
+ regioncx.annotate(tcx, &mut err);
err.note(&format!(
"number of external vids: {}",
@@ -319,7 +319,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
.sess
.diagnostic()
.span_note_diag(mir.span, "No external requirements");
- regioncx.annotate(&mut err);
+ regioncx.annotate(tcx, &mut err);
err.buffer(errors_buffer);
}
diff --git a/src/librustc_mir/borrow_check/nll/region_infer/annotation.rs b/src/librustc_mir/borrow_check/nll/region_infer/annotation.rs
deleted file mode 100644
index 7cde06be0c23b..0000000000000
--- a/src/librustc_mir/borrow_check/nll/region_infer/annotation.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! As part of the NLL unit tests, you can annotate a function with
-//! `#[rustc_regions]`, and we will emit information about the region
-//! inference context and -- in particular -- the external constraints
-//! that this region imposes on others. The methods in this file
-//! handle the part about dumping the inference context internal
-//! state.
-
-use borrow_check::nll::region_infer::RegionInferenceContext;
-use borrow_check::nll::universal_regions::DefiningTy;
-use rustc_errors::DiagnosticBuilder;
-
-impl<'tcx> RegionInferenceContext<'tcx> {
- /// Write out our state into the `.mir` files.
- pub(crate) fn annotate(&self, err: &mut DiagnosticBuilder<'_>) {
- match self.universal_regions.defining_ty {
- DefiningTy::Closure(def_id, substs) => {
- err.note(&format!(
- "defining type: {:?} with closure substs {:#?}",
- def_id,
- &substs.substs[..]
- ));
- }
- DefiningTy::Generator(def_id, substs, _) => {
- err.note(&format!(
- "defining type: {:?} with generator substs {:#?}",
- def_id,
- &substs.substs[..]
- ));
- }
- DefiningTy::FnDef(def_id, substs) => {
- err.note(&format!(
- "defining type: {:?} with substs {:#?}",
- def_id,
- &substs[..]
- ));
- }
- DefiningTy::Const(def_id, substs) => {
- err.note(&format!(
- "defining constant type: {:?} with substs {:#?}",
- def_id,
- &substs[..]
- ));
- }
- }
- }
-}
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 bbdf2a9292210..cb15c88bb3e6f 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
@@ -29,11 +29,10 @@ use rustc::util::common;
use rustc_data_structures::graph::scc::Sccs;
use rustc_data_structures::indexed_set::IdxSet;
use rustc_data_structures::indexed_vec::IndexVec;
-use rustc_errors::Diagnostic;
+use rustc_errors::{DiagnosticBuilder, Diagnostic};
use std::rc::Rc;
-mod annotation;
mod dump_mir;
mod error_reporting;
mod graphviz;
@@ -359,6 +358,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
self.universal_regions.to_region_vid(r)
}
+ /// Add annotations for `#[rustc_regions]`; see `UniversalRegions::annotate`.
+ crate fn annotate(&self, tcx: TyCtxt<'_, '_, 'tcx>, err: &mut DiagnosticBuilder<'_>) {
+ self.universal_regions.annotate(tcx, err)
+ }
+
/// Returns true if the region `r` contains the point `p`.
///
/// Panics if called before `solve()` executes,
@@ -686,7 +690,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
test: _,
} = type_test;
-
let generic_ty = generic_kind.to_ty(tcx);
let subject = match self.try_promote_type_test_subject(infcx, generic_ty) {
Some(s) => s,
@@ -698,20 +701,38 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// `ClosureOutlivesRequirement`.
let r_scc = self.constraint_sccs.scc(*lower_bound);
for ur in self.scc_values.universal_regions_outlived_by(r_scc) {
+ // Check whether we can already prove that the "subject" outlives `ur`.
+ // If so, we don't have to propagate this requirement to our caller.
+ //
+ // To continue the example from the function, if we are trying to promote
+ // a requirement that `T: 'X`, and we know that `'X = '1 + '2` (i.e., the union
+ // `'1` and `'2`), then in this loop `ur` will be `'1` (and `'2`). So here
+ // we check whether `T: '1` is something we *can* prove. If so, no need
+ // to propagate that requirement.
+ //
+ // This is needed because -- particularly in the case
+ // where `ur` is a local bound -- we are sometimes in a
+ // position to prove things that our caller cannot. See
+ // #53570 for an example.
+ if self.eval_region_test(mir, ur, &type_test.test) {
+ continue;
+ }
+
+ debug!("try_promote_type_test: ur={:?}", ur);
+
let non_local_ub = self.universal_region_relations.non_local_upper_bound(ur);
+ debug!("try_promote_type_test: non_local_ub={:?}", non_local_ub);
assert!(self.universal_regions.is_universal_region(non_local_ub));
- assert!(
- !self
- .universal_regions
- .is_local_free_region(non_local_ub)
- );
+ assert!(!self.universal_regions.is_local_free_region(non_local_ub));
- propagated_outlives_requirements.push(ClosureOutlivesRequirement {
+ let requirement = ClosureOutlivesRequirement {
subject,
outlived_free_region: non_local_ub,
blame_span: locations.span(mir),
- });
+ };
+ debug!("try_promote_type_test: pushing {:#?}", requirement);
+ propagated_outlives_requirements.push(requirement);
}
true
}
@@ -917,8 +938,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// now). Therefore, the sup-region outlives the sub-region if,
// for each universal region R1 in the sub-region, there
// exists some region R2 in the sup-region that outlives R1.
- let universal_outlives = self
- .scc_values
+ let universal_outlives = self.scc_values
.universal_regions_outlived_by(sub_region_scc)
.all(|r1| {
self.scc_values
@@ -1029,8 +1049,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// (because `fr` includes `end(o)`).
for shorter_fr in self.scc_values.universal_regions_outlived_by(longer_fr_scc) {
// If it is known that `fr: o`, carry on.
- if self
- .universal_region_relations
+ if self.universal_region_relations
.outlives(longer_fr, shorter_fr)
{
continue;
@@ -1046,8 +1065,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
if let Some(propagated_outlives_requirements) = propagated_outlives_requirements {
// Shrink `fr` until we find a non-local region (if we do).
// We'll call that `fr-` -- it's ever so slightly smaller than `fr`.
- if let Some(fr_minus) = self
- .universal_region_relations
+ if let Some(fr_minus) = self.universal_region_relations
.non_local_lower_bound(longer_fr)
{
debug!("check_universal_region: fr_minus={:?}", fr_minus);
@@ -1056,8 +1074,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// region. (We always will.) We'll call that
// `shorter_fr+` -- it's ever so slightly larger than
// `fr`.
- let shorter_fr_plus = self
- .universal_region_relations
+ let shorter_fr_plus = self.universal_region_relations
.non_local_upper_bound(shorter_fr);
debug!(
"check_universal_region: shorter_fr_plus={:?}",
@@ -1117,8 +1134,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
let error_region = match error_element {
RegionElement::Location(l) => self.find_sub_region_live_at(longer_fr, l),
RegionElement::RootUniversalRegion(r) => r,
- RegionElement::SubUniversalRegion(error_ui) => self
- .definitions
+ RegionElement::SubUniversalRegion(error_ui) => self.definitions
.iter_enumerated()
.filter_map(|(r, definition)| match definition.origin {
NLLRegionVariableOrigin::BoundRegion(ui) if error_ui == ui => Some(r),
@@ -1215,7 +1231,11 @@ impl<'gcx, 'tcx> ClosureRegionRequirementsExt<'gcx, 'tcx> for ClosureRegionRequi
// 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, self.num_external_vids, tcx.closure_base_def_id(closure_def_id));
+ tcx,
+ user_closure_ty,
+ self.num_external_vids,
+ tcx.closure_base_def_id(closure_def_id),
+ );
debug!("apply_requirements: closure_mapping={:?}", closure_mapping);
// Create the predicates.
diff --git a/src/librustc_mir/borrow_check/nll/universal_regions.rs b/src/librustc_mir/borrow_check/nll/universal_regions.rs
index 5115312825605..eb6f1a0677b2c 100644
--- a/src/librustc_mir/borrow_check/nll/universal_regions.rs
+++ b/src/librustc_mir/borrow_check/nll/universal_regions.rs
@@ -31,6 +31,7 @@ use rustc::ty::subst::Substs;
use rustc::ty::{self, ClosureSubsts, GeneratorSubsts, RegionVid, Ty, TyCtxt};
use rustc::util::nodemap::FxHashMap;
use rustc_data_structures::indexed_vec::{Idx, IndexVec};
+use rustc_errors::DiagnosticBuilder;
use std::iter;
use syntax::ast;
@@ -310,6 +311,69 @@ impl<'tcx> UniversalRegions<'tcx> {
pub fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
self.indices.to_region_vid(r)
}
+
+ /// As part of the NLL unit tests, you can annotate a function with
+ /// `#[rustc_regions]`, and we will emit information about the region
+ /// inference context and -- in particular -- the external constraints
+ /// that this region imposes on others. The methods in this file
+ /// handle the part about dumping the inference context internal
+ /// state.
+ crate fn annotate(&self, tcx: TyCtxt<'_, '_, 'tcx>, err: &mut DiagnosticBuilder<'_>) {
+ match self.defining_ty {
+ DefiningTy::Closure(def_id, substs) => {
+ err.note(&format!(
+ "defining type: {:?} with closure substs {:#?}",
+ def_id,
+ &substs.substs[..]
+ ));
+
+ // FIXME: It'd be nice to print the late-bound regions
+ // here, but unfortunately these wind up stored into
+ // tests, and the resulting print-outs include def-ids
+ // and other things that are not stable across tests!
+ // So we just include the region-vid. Annoying.
+ let closure_base_def_id = tcx.closure_base_def_id(def_id);
+ for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+ err.note(&format!(
+ "late-bound region is {:?}",
+ self.to_region_vid(r),
+ ));
+ });
+ }
+ DefiningTy::Generator(def_id, substs, _) => {
+ err.note(&format!(
+ "defining type: {:?} with generator substs {:#?}",
+ def_id,
+ &substs.substs[..]
+ ));
+
+ // FIXME: As above, we'd like to print out the region
+ // `r` but doing so is not stable across architectures
+ // and so forth.
+ let closure_base_def_id = tcx.closure_base_def_id(def_id);
+ for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+ err.note(&format!(
+ "late-bound region is {:?}",
+ self.to_region_vid(r),
+ ));
+ });
+ }
+ DefiningTy::FnDef(def_id, substs) => {
+ err.note(&format!(
+ "defining type: {:?} with substs {:#?}",
+ def_id,
+ &substs[..]
+ ));
+ }
+ DefiningTy::Const(def_id, substs) => {
+ err.note(&format!(
+ "defining constant type: {:?} with substs {:#?}",
+ def_id,
+ &substs[..]
+ ));
+ }
+ }
+ }
}
struct UniversalRegionsBuilder<'cx, 'gcx: 'tcx, 'tcx: 'cx> {
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
index 892910686433a..fa14d496a1441 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
@@ -12,6 +12,9 @@ LL | | },
i16,
for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
]
+ = note: late-bound region is '_#4r
+ = note: late-bound region is '_#5r
+ = note: late-bound region is '_#6r
error: unsatisfied lifetime constraints
--> $DIR/propagate-approximated-fail-no-postdom.rs:56:13
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
index 1ff9374c21267..1af96b97e73bd 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
@@ -14,6 +14,8 @@ LL | | });
i16,
for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
]
+ = note: late-bound region is '_#3r
+ = note: late-bound region is '_#4r
= note: number of external vids: 5
= note: where '_#1r: '_#2r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
index f50864d946be9..9de9e21ba43d2 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
@@ -15,6 +15,8 @@ LL | | });
i16,
for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) u32>))
]
+ = note: late-bound region is '_#2r
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where '_#1r: '_#0r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
index 8a89320d10cad..6acb675005540 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
@@ -14,6 +14,8 @@ LL | | });
i16,
for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
]
+ = note: late-bound region is '_#3r
+ = note: late-bound region is '_#4r
= note: number of external vids: 5
= note: where '_#1r: '_#0r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
index 71dbc412fef4c..e0902ca1ddbe8 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
@@ -14,6 +14,8 @@ LL | | });
i16,
for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
]
+ = note: late-bound region is '_#3r
+ = note: late-bound region is '_#4r
= note: number of external vids: 5
= note: where '_#1r: '_#2r
diff --git a/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr b/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
index d189385213fa1..a3f78507d8d0c 100644
--- a/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
@@ -12,6 +12,7 @@ LL | | },
i16,
for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
]
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where '_#1r: '_#2r
diff --git a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
index a63c6b1670837..31cad6ba1b570 100644
--- a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
@@ -13,6 +13,8 @@ LL | | });
i16,
for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
]
+ = note: late-bound region is '_#2r
+ = note: late-bound region is '_#3r
error: unsatisfied lifetime constraints
--> $DIR/propagate-fail-to-approximate-longer-no-bounds.rs:47:9
diff --git a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
index 67510a5a81f11..4e21816e8c0c4 100644
--- a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
@@ -13,6 +13,8 @@ LL | | });
i16,
for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
]
+ = note: late-bound region is '_#3r
+ = note: late-bound region is '_#4r
error: unsatisfied lifetime constraints
--> $DIR/propagate-fail-to-approximate-longer-wrong-bounds.rs:51:9
diff --git a/src/test/ui/nll/issue-53570.rs b/src/test/ui/nll/issue-53570.rs
new file mode 100644
index 0000000000000..9617e40ec39d9
--- /dev/null
+++ b/src/test/ui/nll/issue-53570.rs
@@ -0,0 +1,46 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Regression test for #53570. Here, we need to propagate that `T: 'a`
+// but in some versions of NLL we were propagating a stronger
+// requirement that `T: 'static`. This arose because we actually had
+// to propagate both that `T: 'a` but also `T: 'b` where `'b` is the
+// higher-ranked lifetime that appears in the type of the closure
+// parameter `x` -- since `'b` cannot be expressed in the caller's
+// space, that got promoted th `'static`.
+//
+// compile-pass
+
+#![feature(nll)]
+#![feature(rustc_attrs)]
+#![allow(dead_code)]
+
+use std::cell::{RefCell, Ref};
+
+trait AnyVec<'a> {
+}
+
+trait GenericVec<T> {
+ fn unwrap<'a, 'b>(vec: &'b AnyVec<'a>) -> &'b [T] where T: 'a;
+}
+
+struct Scratchpad<'a> {
+ buffers: RefCell<Box<AnyVec<'a>>>,
+}
+
+impl<'a> Scratchpad<'a> {
+ fn get<T: GenericVec<T>>(&self) -> Ref<[T]>
+ where T: 'a
+ {
+ Ref::map(self.buffers.borrow(), |x| T::unwrap(x.as_ref()))
+ }
+}
+
+fn main() { }
diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
index 24f4bea1ba2f8..a91761f3ece2f 100644
--- a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
@@ -10,6 +10,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
i32,
extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
]
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where T: '_#2r
= note: where '_#1r: '_#2r
diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr
index df4f619b7763b..0064393f271ca 100644
--- a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr
@@ -10,6 +10,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
i32,
extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
]
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where '_#1r: '_#2r
diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-static-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-static-closure.stderr
index 136e143e80edf..3f8ed324f564a 100644
--- a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-static-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-static-closure.stderr
@@ -10,6 +10,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
i32,
extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
]
+ = note: late-bound region is '_#3r
note: No external requirements
--> $DIR/projection-one-region-trait-bound-static-closure.rs:42:1
diff --git a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
index 176e45ae09872..19dcb5f93dac3 100644
--- a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
@@ -11,6 +11,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
i32,
extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T))
]
+ = note: late-bound region is '_#4r
= note: number of external vids: 5
= note: where <T as Anything<ReClosureBound('_#1r), ReClosureBound('_#2r)>>::AssocType: '_#3r
@@ -212,6 +213,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
i32,
extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
]
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where <T as Anything<ReClosureBound('_#1r), ReClosureBound('_#1r)>>::AssocType: '_#2r
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
index 1f5edf08957d6..106eaa6a3abe9 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
@@ -36,6 +36,7 @@ LL | twice(cell, value, |a, b| invoke(a, b));
i16,
for<'r, 's> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) ()>>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) T))
]
+ = note: late-bound region is '_#2r
= note: number of external vids: 3
= note: where T: '_#1r
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
index 1b9baf61305d9..f0e86a580b20a 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-where-clause.stderr
@@ -16,6 +16,7 @@ LL | | })
i32,
extern "rust-call" fn((std::cell::Cell<&'_#1r ()>, T))
]
+ = note: late-bound region is '_#2r
= note: number of external vids: 3
= note: where T: '_#1r
@@ -106,6 +107,7 @@ LL | | })
i32,
extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
]
+ = note: late-bound region is '_#3r
= note: number of external vids: 4
= note: where T: '_#2r