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Auto merge of #52021 - nikomatsakis:nll-region-errors, r=estebank

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refactor and cleanup region errors for NLL

This is a WIP commit. It simplifies some of the code from https://github.com/rust-lang/rust/pull/51536 and extends a few more steps towards the errors that @davidtwco and I were shooting for. These are intended as a replacement for the general "unable to infer lifetime" messages -- one that is actually actionable. We're certainly not there yet, but the overall shape hopefully gets a bit clearer.

I'm thinking about trying to open up an internals thread to sketch out the overall plan and perhaps discuss how to get the wording right, which special cases to handle, etc.

r? @estebank
cc @davidtwco
This commit is contained in:
bors 2018-07-06 23:36:16 +00:00
commit a178cba9f1
53 changed files with 692 additions and 293 deletions
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2
src/librustc/ich/impls_mir.rs
View file

@ -30,7 +30,7 @@ impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
internal,
is_user_variable
});
impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref, mutability });
impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, var_hir_id, by_ref, mutability });
impl_stable_hash_for!(struct mir::BasicBlockData<'tcx> { statements, terminator, is_cleanup });
impl_stable_hash_for!(struct mir::UnsafetyViolation { source_info, description, kind });
impl_stable_hash_for!(struct mir::UnsafetyCheckResult { violations, unsafe_blocks });

14
src/librustc/mir/mod.rs
View file

@ -15,7 +15,7 @@
use graphviz::IntoCow;
use hir::def::CtorKind;
use hir::def_id::DefId;
use hir::{self, InlineAsm};
use hir::{self, HirId, InlineAsm};
use middle::region;
use mir::interpret::{EvalErrorKind, Scalar, Value};
use mir::visit::MirVisitable;
@ -380,6 +380,15 @@ pub enum ClearCrossCrate<T> {
Set(T),
}
impl<T> ClearCrossCrate<T> {
pub fn assert_crate_local(self) -> T {
match self {
ClearCrossCrate::Clear => bug!("unwrapping cross-crate data"),
ClearCrossCrate::Set(v) => v,
}
}
}
impl<T: serialize::Encodable> serialize::UseSpecializedEncodable for ClearCrossCrate<T> {}
impl<T: serialize::Decodable> serialize::UseSpecializedDecodable for ClearCrossCrate<T> {}
@ -785,6 +794,9 @@ impl<'tcx> LocalDecl<'tcx> {
pub struct UpvarDecl {
pub debug_name: Name,
/// `HirId` of the captured variable
pub var_hir_id: ClearCrossCrate<HirId>,
/// If true, the capture is behind a reference.
pub by_ref: bool,

46
src/librustc/ty/fold.rs
View file

@ -253,13 +253,34 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
value.fold_with(&mut RegionFolder::new(self, skipped_regions, &mut f))
}
pub fn for_each_free_region<T,F>(self,
value: &T,
callback: F)
where F: FnMut(ty::Region<'tcx>),
T: TypeFoldable<'tcx>,
{
value.visit_with(&mut RegionVisitor {
/// Invoke `callback` on every region appearing free in `value`.
pub fn for_each_free_region(
self,
value: &impl TypeFoldable<'tcx>,
mut callback: impl FnMut(ty::Region<'tcx>),
) {
self.any_free_region_meets(value, |r| {
callback(r);
false
});
}
/// True if `callback` returns true for every region appearing free in `value`.
pub fn all_free_regions_meet(
self,
value: &impl TypeFoldable<'tcx>,
mut callback: impl FnMut(ty::Region<'tcx>) -> bool,
) -> bool {
!self.any_free_region_meets(value, |r| !callback(r))
}
/// True if `callback` returns true for some region appearing free in `value`.
pub fn any_free_region_meets(
self,
value: &impl TypeFoldable<'tcx>,
callback: impl FnMut(ty::Region<'tcx>) -> bool,
) -> bool {
return value.visit_with(&mut RegionVisitor {
outer_index: ty::INNERMOST,
callback
});
@ -287,25 +308,22 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
}
impl<'tcx, F> TypeVisitor<'tcx> for RegionVisitor<F>
where F : FnMut(ty::Region<'tcx>)
where F: FnMut(ty::Region<'tcx>) -> bool
{
fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> bool {
self.outer_index.shift_in(1);
t.skip_binder().visit_with(self);
let result = t.skip_binder().visit_with(self);
self.outer_index.shift_out(1);
false // keep visiting
result
}
fn visit_region(&mut self, r: ty::Region<'tcx>) -> bool {
match *r {
ty::ReLateBound(debruijn, _) if debruijn < self.outer_index => {
/* ignore bound regions */
false // ignore bound regions, keep visiting
}
_ => (self.callback)(r),
}
false // keep visiting
}
}
}

10
src/librustc_mir/borrow_check/mod.rs
View file

@ -128,6 +128,8 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
input_mir: &Mir<'gcx>,
def_id: DefId,
) -> BorrowCheckResult<'gcx> {
debug!("do_mir_borrowck(def_id = {:?})", def_id);
let tcx = infcx.tcx;
let attributes = tcx.get_attrs(def_id);
let param_env = tcx.param_env(def_id);
@ -319,10 +321,14 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
}
}
BorrowCheckResult {
let result = BorrowCheckResult {
closure_requirements: opt_closure_req,
used_mut_upvars: mbcx.used_mut_upvars,
}
};
debug!("do_mir_borrowck: result = {:#?}", result);
result
}
#[allow(dead_code)]

261
src/librustc_mir/borrow_check/nll/region_infer/error_reporting.rs → src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs
View file

@ -8,19 +8,21 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::fmt;
use borrow_check::nll::region_infer::{ConstraintIndex, RegionInferenceContext};
use borrow_check::nll::region_infer::values::ToElementIndex;
use borrow_check::nll::region_infer::{ConstraintIndex, RegionInferenceContext};
use borrow_check::nll::type_check::Locations;
use rustc::hir::def_id::DefId;
use rustc::infer::InferCtxt;
use rustc::infer::error_reporting::nice_region_error::NiceRegionError;
use rustc::mir::{self, Location, Mir, Place, StatementKind, TerminatorKind, Rvalue};
use rustc::infer::InferCtxt;
use rustc::mir::{self, Location, Mir, Place, Rvalue, StatementKind, TerminatorKind};
use rustc::ty::RegionVid;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::fx::FxHashSet;
use rustc_data_structures::indexed_vec::IndexVec;
use std::fmt;
use syntax_pos::Span;
mod region_name;
/// Constraints that are considered interesting can be categorized to
/// determine why they are interesting. Order of variants indicates
/// sort order of the category, thereby influencing diagnostic output.
@ -47,115 +49,105 @@ impl fmt::Display for ConstraintCategory {
}
impl<'tcx> RegionInferenceContext<'tcx> {
/// When reporting an error, it is useful to be able to determine which constraints influenced
/// the region being reported as an error. This function finds all of the paths from the
/// Walks the graph of constraints (where `'a: 'b` is considered
/// an edge `'b -> 'a`) to find all paths from `from_region` to
/// `to_region`. The paths are accumulated into the vector
/// `results`. The paths are stored as a series of
/// `ConstraintIndex` values -- in other words, a list of *edges*.
///
/// # Parameters
///
/// - `from_region`
/// When reporting an error, it is useful to be able to determine
/// which constraints influenced the region being reported as an
/// error. This function finds all of the paths from the
/// constraint.
fn find_constraint_paths_from_region(
fn find_constraint_paths_between_regions(
&self,
r0: RegionVid
from_region: RegionVid,
target_test: impl Fn(RegionVid) -> bool,
) -> Vec<Vec<ConstraintIndex>> {
let constraints = self.constraints.clone();
let mut results = vec![];
self.find_constraint_paths_between_regions_helper(
from_region,
from_region,
&target_test,
&mut FxHashSet::default(),
&mut vec![],
&mut results,
);
results
}
// Mapping of regions to the previous region and constraint index that led to it.
let mut previous = FxHashMap();
// Regions yet to be visited.
let mut next = vec! [ r0 ];
// Regions that have been visited.
let mut visited = FxHashSet();
// Ends of paths.
let mut end_regions = FxHashSet();
// When we've still got points to visit...
while let Some(current) = next.pop() {
// ...take the next point...
debug!("find_constraint_paths_from_region: current={:?} visited={:?} next={:?}",
current, visited, next);
// ...but make sure not to visit this point again...
visited.insert(current);
// ...find the edges containing it...
let mut upcoming = Vec::new();
for (index, constraint) in constraints.iter_enumerated() {
if constraint.sub == current {
// ...add the regions that join us with to the path we've taken...
debug!("find_constraint_paths_from_region: index={:?} constraint={:?}",
index, constraint);
let next_region = constraint.sup.clone();
// ...unless we've visited it since this was added...
if visited.contains(&next_region) {
debug!("find_constraint_paths_from_region: skipping as visited");
continue;
}
previous.insert(next_region, (index, Some(current)));
upcoming.push(next_region);
}
}
if upcoming.is_empty() {
// If we didn't find any edges then this is the end of a path...
debug!("find_constraint_paths_from_region: new end region current={:?}", current);
end_regions.insert(current);
} else {
// ...but, if we did find edges, then add these to the regions yet to visit.
debug!("find_constraint_paths_from_region: extend next upcoming={:?}", upcoming);
next.extend(upcoming);
}
/// Helper for `find_constraint_paths_between_regions`.
fn find_constraint_paths_between_regions_helper(
&self,
from_region: RegionVid,
current_region: RegionVid,
target_test: &impl Fn(RegionVid) -> bool,
visited: &mut FxHashSet<RegionVid>,
stack: &mut Vec<ConstraintIndex>,
results: &mut Vec<Vec<ConstraintIndex>>,
) {
let dependency_map = self.dependency_map.as_ref().unwrap();
// Check if we already visited this region.
if !visited.insert(current_region) {
return;
}
// Now we've visited each point, compute the final paths.
let mut paths: Vec<Vec<ConstraintIndex>> = Vec::new();
debug!("find_constraint_paths_from_region: end_regions={:?}", end_regions);
for end_region in end_regions {
debug!("find_constraint_paths_from_region: end_region={:?}", end_region);
// Get the constraint and region that led to this end point.
// We can unwrap as we know if end_point was in the vector that it
// must also be in our previous map.
let (mut index, mut region) = previous.get(&end_region).unwrap();
debug!("find_constraint_paths_from_region: index={:?} region={:?}", index, region);
// Keep track of the indices.
let mut path: Vec<ConstraintIndex> = vec![index];
while region.is_some() && region != Some(r0) {
let p = previous.get(&region.unwrap()).unwrap();
index = p.0;
region = p.1;
debug!("find_constraint_paths_from_region: index={:?} region={:?}", index, region);
path.push(index);
// Check if we reached the region we were looking for.
if target_test(current_region) {
if !stack.is_empty() {
assert_eq!(self.constraints[stack[0]].sub, from_region);
results.push(stack.clone());
}
// Add to our paths.
paths.push(path);
return;
}
debug!("find_constraint_paths_from_region: paths={:?}", paths);
paths
self.constraints
.each_affected_by_dirty(dependency_map[current_region], |constraint| {
assert_eq!(self.constraints[constraint].sub, current_region);
stack.push(constraint);
self.find_constraint_paths_between_regions_helper(
from_region,
self.constraints[constraint].sup,
target_test,
visited,
stack,
results,
);
stack.pop();
});
}
/// This function will return true if a constraint is interesting and false if a constraint
/// is not. It is useful in filtering constraint paths to only interesting points.
fn constraint_is_interesting(&self, index: &ConstraintIndex) -> bool {
self.constraints.get(*index).filter(|constraint| {
debug!("constraint_is_interesting: locations={:?} constraint={:?}",
constraint.locations, constraint);
if let Locations::Interesting(_) = constraint.locations { true } else { false }
}).is_some()
fn constraint_is_interesting(&self, index: ConstraintIndex) -> bool {
let constraint = self.constraints[index];
debug!(
"constraint_is_interesting: locations={:?} constraint={:?}",
constraint.locations, constraint
);
if let Locations::Interesting(_) = constraint.locations {
true
} else {
false
}
}
/// This function classifies a constraint from a location.
fn classify_constraint(&self, index: &ConstraintIndex,
mir: &Mir<'tcx>) -> Option<(ConstraintCategory, Span)> {
let constraint = self.constraints.get(*index)?;
fn classify_constraint(
&self,
index: ConstraintIndex,
mir: &Mir<'tcx>,
) -> (ConstraintCategory, Span) {
let constraint = self.constraints[index];
let span = constraint.locations.span(mir);
let location = constraint.locations.from_location()?;
let location = constraint.locations.from_location().unwrap_or(Location::START);
if !self.constraint_is_interesting(index) {
return Some((ConstraintCategory::Boring, span));
return (ConstraintCategory::Boring, span);
}
let data = &mir[location.block];
@ -182,12 +174,12 @@ impl<'tcx> RegionInferenceContext<'tcx> {
_ => ConstraintCategory::Other,
}
}
},
}
_ => ConstraintCategory::Other,
}
};
Some((category, span))
(category, span)
}
/// Report an error because the universal region `fr` was required to outlive
@ -207,12 +199,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
outlived_fr: RegionVid,
blame_span: Span,
) {
// Obviously uncool error reporting.
debug!("report_error(fr={:?}, outlived_fr={:?})", fr, outlived_fr);
let fr_name = self.to_error_region(fr);
let outlived_fr_name = self.to_error_region(outlived_fr);
if let (Some(f), Some(o)) = (fr_name, outlived_fr_name) {
if let (Some(f), Some(o)) = (self.to_error_region(fr), self.to_error_region(outlived_fr)) {
let tables = infcx.tcx.typeck_tables_of(mir_def_id);
let nice = NiceRegionError::new_from_span(infcx.tcx, blame_span, o, f, Some(tables));
if let Some(_error_reported) = nice.try_report() {
@ -220,43 +209,52 @@ impl<'tcx> RegionInferenceContext<'tcx> {
}
}
let fr_string = match fr_name {
Some(r) => format!("free region `{}`", r),
None => format!("free region `{:?}`", fr),
};
// Find all paths
let constraint_paths = self.find_constraint_paths_between_regions(outlived_fr, |r| r == fr);
debug!("report_error: constraint_paths={:#?}", constraint_paths);
let outlived_fr_string = match outlived_fr_name {
Some(r) => format!("free region `{}`", r),
None => format!("free region `{:?}`", outlived_fr),
};
let constraints = self.find_constraint_paths_from_region(fr.clone());
let path = constraints.iter().min_by_key(|p| p.len()).unwrap();
// Find the shortest such path.
let path = constraint_paths.iter().min_by_key(|p| p.len()).unwrap();
debug!("report_error: shortest_path={:?}", path);
let mut categorized_path = path.iter().filter_map(|index| {
self.classify_constraint(index, mir)
}).collect::<Vec<(ConstraintCategory, Span)>>();
// Classify each of the constraints along the path.
let mut categorized_path: Vec<(ConstraintCategory, Span)> = path.iter()
.map(|&index| self.classify_constraint(index, mir))
.collect();
debug!("report_error: categorized_path={:?}", categorized_path);
// Find what appears to be the most interesting path to report to the user.
categorized_path.sort_by(|p0, p1| p0.0.cmp(&p1.0));
debug!("report_error: sorted_path={:?}", categorized_path);
if let Some((category, span)) = &categorized_path.first() {
let mut diag = infcx.tcx.sess.struct_span_err(
*span, &format!("{} requires that data must outlive {}",
category, outlived_fr_string),
);
// Get a span
let (category, span) = categorized_path.first().unwrap();
let diag = &mut infcx.tcx.sess.struct_span_err(
*span,
&format!("unsatisfied lifetime constraints"), // FIXME
);
diag.emit();
} else {
let mut diag = infcx.tcx.sess.struct_span_err(
blame_span,
&format!("{} does not outlive {}", fr_string, outlived_fr_string,),
);
// Figure out how we can refer
let counter = &mut 1;
let fr_name = self.give_region_a_name(infcx.tcx, mir, mir_def_id, fr, counter, diag);
let outlived_fr_name = self.give_region_a_name(
infcx.tcx,
mir,
mir_def_id,
outlived_fr,
counter,
diag,
);
diag.emit();
}
diag.span_label(
*span,
format!(
"{} requires that `{}` must outlive `{}`",
category, fr_name, outlived_fr_name,
),
);
diag.emit();
}
// Find some constraint `X: Y` where:
@ -269,8 +267,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
/// Tries to finds a good span to blame for the fact that `fr1`
/// contains `fr2`.
pub(super) fn blame_constraint(&self, fr1: RegionVid,
elem: impl ToElementIndex) -> ConstraintIndex {
pub(super) fn blame_constraint(
&self,
fr1: RegionVid,
elem: impl ToElementIndex,
) -> ConstraintIndex {
// Find everything that influenced final value of `fr`.
let influenced_fr1 = self.dependencies(fr1);

256
src/librustc_mir/borrow_check/nll/region_infer/error_reporting/region_name.rs Normal file
View file

@ -0,0 +1,256 @@
// 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.
use borrow_check::nll::region_infer::RegionInferenceContext;
use borrow_check::nll::ToRegionVid;
use rustc::hir::def_id::DefId;
use rustc::mir::{Local, Mir};
use rustc::ty::{self, RegionVid, TyCtxt};
use rustc_data_structures::indexed_vec::Idx;
use rustc_errors::DiagnosticBuilder;
use syntax::ast::Name;
use syntax::symbol::keywords;
use syntax_pos::symbol::InternedString;
impl<'tcx> RegionInferenceContext<'tcx> {
/// Maps from an internal MIR region vid to something that we can
/// report to the user. In some cases, the region vids will map
/// directly to lifetimes that the user has a name for (e.g.,
/// `'static`). But frequently they will not, in which case we
/// have to find some way to identify the lifetime to the user. To
/// that end, this function takes a "diagnostic" so that it can
/// create auxiliary notes as needed.
///
/// Example (function arguments):
///
/// Suppose we are trying to give a name to the lifetime of the
/// reference `x`:
///
/// ```
/// fn foo(x: &u32) { .. }
/// ```
///
/// This function would create a label like this:
///
/// ```
/// | fn foo(x: &u32) { .. }
/// ------- fully elaborated type of `x` is `&'1 u32`
/// ```
///
/// and then return the name `'1` for us to use.
crate fn give_region_a_name(
&self,
tcx: TyCtxt<'_, '_, 'tcx>,
mir: &Mir<'tcx>,
mir_def_id: DefId,
fr: RegionVid,
counter: &mut usize,
diag: &mut DiagnosticBuilder,
) -> InternedString {
debug!("give_region_a_name(fr={:?}, counter={})", fr, counter);
assert!(self.universal_regions.is_universal_region(fr));
self.give_name_from_error_region(tcx, mir_def_id, fr, counter, diag)
.or_else(|| {
self.give_name_if_anonymous_region_appears_in_arguments(tcx, mir, fr, counter, diag)
})
.or_else(|| {
self.give_name_if_anonymous_region_appears_in_upvars(tcx, mir, fr, counter, diag)
})
.or_else(|| {
self.give_name_if_anonymous_region_appears_in_output(tcx, mir, fr, counter, diag)
})
.unwrap_or_else(|| span_bug!(mir.span, "can't make a name for free region {:?}", fr))
}
/// Check for the case where `fr` maps to something that the
/// *user* has a name for. In that case, we'll be able to map
/// `fr` to a `Region<'tcx>`, and that region will be one of
/// named variants.
fn give_name_from_error_region(
&self,
tcx: TyCtxt<'_, '_, 'tcx>,
mir_def_id: DefId,
fr: RegionVid,
counter: &mut usize,
diag: &mut DiagnosticBuilder<'_>,
) -> Option<InternedString> {
let error_region = self.to_error_region(fr)?;
debug!("give_region_a_name: error_region = {:?}", error_region);
match error_region {
ty::ReEarlyBound(ebr) => Some(ebr.name),
ty::ReStatic => Some(keywords::StaticLifetime.name().as_interned_str()),
ty::ReFree(free_region) => match free_region.bound_region {
ty::BoundRegion::BrNamed(_, name) => Some(name),
ty::BoundRegion::BrEnv => {
let closure_span = tcx.hir.span_if_local(mir_def_id).unwrap();
let region_name = self.synthesize_region_name(counter);
diag.span_label(
closure_span,
format!("lifetime `{}` represents the closure body", region_name),
);
Some(region_name)
}
ty::BoundRegion::BrAnon(_) | ty::BoundRegion::BrFresh(_) => None,
},
ty::ReLateBound(..)
| ty::ReScope(..)
| ty::ReVar(..)
| ty::ReSkolemized(..)
| ty::ReEmpty
| ty::ReErased
| ty::ReClosureBound(..)
| ty::ReCanonical(..) => None,
}
}
/// Find an argument that contains `fr` and label it with a fully
/// elaborated type, returning something like `'1`. Result looks
/// like:
///
/// ```
/// | fn foo(x: &u32) { .. }
/// ------- fully elaborated type of `x` is `&'1 u32`
/// ```
fn give_name_if_anonymous_region_appears_in_arguments(
&self,
tcx: TyCtxt<'_, '_, 'tcx>,
mir: &Mir<'tcx>,
fr: RegionVid,
counter: &mut usize,
diag: &mut DiagnosticBuilder<'_>,
) -> Option<InternedString> {
let implicit_inputs = self.universal_regions.defining_ty.implicit_inputs();
let argument_index = self.universal_regions
.unnormalized_input_tys
.iter()
.skip(implicit_inputs)
.position(|arg_ty| {
debug!("give_name_if_anonymous_region_appears_in_arguments: arg_ty = {:?}", arg_ty);
tcx.any_free_region_meets(arg_ty, |r| r.to_region_vid() == fr)
})?
+ implicit_inputs;
debug!(
"give_name_if_anonymous_region_appears_in_arguments: \
found {:?} in argument {} which has type {:?}",
fr, argument_index, self.universal_regions.unnormalized_input_tys[argument_index],
);
let region_name = self.synthesize_region_name(counter);
let argument_local = Local::new(argument_index + 1);
let argument_span = mir.local_decls[argument_local].source_info.span;
diag.span_label(
argument_span,
format!("lifetime `{}` appears in this argument", region_name,),
);
Some(region_name)
}
/// Find a closure upvar that contains `fr` and label it with a
/// fully elaborated type, returning something like `'1`. Result
/// looks like:
///
/// ```
/// | let x = Some(&22);
/// - fully elaborated type of `x` is `Option<&'1 u32>`
/// ```
fn give_name_if_anonymous_region_appears_in_upvars(
&self,
tcx: TyCtxt<'_, '_, 'tcx>,
mir: &Mir<'tcx>,
fr: RegionVid,
counter: &mut usize,
diag: &mut DiagnosticBuilder<'_>,
) -> Option<InternedString> {
let upvar_index = self.universal_regions
.defining_ty
.upvar_tys(tcx)
.position(|upvar_ty| {
debug!(
"give_name_if_anonymous_region_appears_in_upvars: upvar_ty = {:?}",
upvar_ty,
);
tcx.any_free_region_meets(&upvar_ty, |r| r.to_region_vid() == fr)
})?;
debug!(
"give_name_if_anonymous_region_appears_in_upvars: \
found {:?} in upvar {} which has type {:?}",
fr,
upvar_index,
self.universal_regions
.defining_ty
.upvar_tys(tcx)
.nth(upvar_index),
);
let region_name = self.synthesize_region_name(counter);
let upvar_hir_id = mir.upvar_decls[upvar_index].var_hir_id.assert_crate_local();
let upvar_node_id = tcx.hir.hir_to_node_id(upvar_hir_id);
let upvar_span = tcx.hir.span(upvar_node_id);
let upvar_name = tcx.hir.name(upvar_node_id);
diag.span_label(
upvar_span,
format!(
"lifetime `{}` appears in the type of `{}`",
region_name, upvar_name,
),
);
Some(region_name)
}
/// Check for arguments appearing in the (closure) return type. It
/// must be a closure since, in a free fn, such an argument would
/// have to either also appear in an argument (if using elision)
/// or be early bound (named, not in argument).
fn give_name_if_anonymous_region_appears_in_output(
&self,
tcx: TyCtxt<'_, '_, 'tcx>,
mir: &Mir<'tcx>,
fr: RegionVid,
counter: &mut usize,
diag: &mut DiagnosticBuilder<'_>,
) -> Option<InternedString> {
let return_ty = self.universal_regions
.unnormalized_output_ty;
debug!("give_name_if_anonymous_region_appears_in_output: return_ty = {:?}", return_ty);
if !tcx.any_free_region_meets(&return_ty, |r| r.to_region_vid() == fr) {
return None;
}
let region_name = self.synthesize_region_name(counter);
diag.span_label(
mir.span,
format!("lifetime `{}` appears in return type", region_name),
);
Some(region_name)
}
/// Create a synthetic region named `'1`, incrementing the
/// counter.
fn synthesize_region_name(&self, counter: &mut usize) -> InternedString {
let c = *counter;
*counter += 1;
Name::intern(&format!("'{:?}", c)).as_interned_str()
}
}

5
src/librustc_mir/borrow_check/nll/region_infer/mod.rs
View file

@ -256,6 +256,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
fn init_universal_regions(&mut self) {
// Update the names (if any)
for (external_name, variable) in self.universal_regions.named_universal_regions() {
debug!(
"init_universal_regions: region {:?} has external name {:?}",
variable,
external_name
);
self.definitions[variable].external_name = Some(external_name);
}

76
src/librustc_mir/borrow_check/nll/universal_regions.rs
View file

@ -22,15 +22,16 @@
//! The code in this file doesn't *do anything* with those results; it
//! just returns them for other code to use.
use rustc::hir::{self, BodyOwnerKind, HirId};
use either::Either;
use rustc::hir::def_id::DefId;
use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
use rustc::infer::region_constraints::GenericKind;
use rustc::hir::{self, BodyOwnerKind, HirId};
use rustc::infer::outlives::bounds::{self, OutlivesBound};
use rustc::infer::outlives::free_region_map::FreeRegionRelations;
use rustc::ty::{self, RegionVid, Ty, TyCtxt, ClosureSubsts, GeneratorSubsts};
use rustc::infer::region_constraints::GenericKind;
use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
use rustc::ty::fold::TypeFoldable;
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_data_structures::transitive_relation::TransitiveRelation;
@ -128,6 +129,34 @@ pub enum DefiningTy<'tcx> {
Const(DefId, &'tcx Substs<'tcx>),
}
impl<'tcx> DefiningTy<'tcx> {
/// Returns a list of all the upvar types for this MIR. If this is
/// not a closure or generator, there are no upvars, and hence it
/// will be an empty list. The order of types in this list will
/// match up with the `upvar_decls` field of `Mir`.
pub fn upvar_tys(self, tcx: TyCtxt<'_, '_, 'tcx>) -> impl Iterator<Item = Ty<'tcx>> + 'tcx {
match self {
DefiningTy::Closure(def_id, substs) => Either::Left(substs.upvar_tys(def_id, tcx)),
DefiningTy::Generator(def_id, substs, _) => {
Either::Right(Either::Left(substs.upvar_tys(def_id, tcx)))
}
DefiningTy::FnDef(..) | DefiningTy::Const(..) => {
Either::Right(Either::Right(iter::empty()))
}
}
}
/// Number of implicit inputs -- notably the "environment"
/// parameter for closures -- that appear in MIR but not in the
/// user's code.
pub fn implicit_inputs(self) -> usize {
match self {
DefiningTy::Closure(..) | DefiningTy::Generator(..) => 1,
DefiningTy::FnDef(..) | DefiningTy::Const(..) => 0,
}
}
}
#[derive(Debug)]
struct UniversalRegionIndices<'tcx> {
/// For those regions that may appear in the parameter environment
@ -493,18 +522,15 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
debug!(
"build: global regions = {}..{}",
FIRST_GLOBAL_INDEX,
first_extern_index
FIRST_GLOBAL_INDEX, first_extern_index
);
debug!(
"build: extern regions = {}..{}",
first_extern_index,
first_local_index
first_extern_index, first_local_index
);
debug!(
"build: local regions = {}..{}",
first_local_index,
num_universals
first_local_index, num_universals
);
let yield_ty = match defining_ty {
@ -545,10 +571,12 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
tables.node_id_to_type(self.mir_hir_id)
};
debug!("defining_ty (pre-replacement): {:?}", defining_ty);
let defining_ty = self.infcx
.replace_free_regions_with_nll_infer_vars(FR, &defining_ty);
match defining_ty.sty {
match defining_ty.sty {
ty::TyClosure(def_id, substs) => DefiningTy::Closure(def_id, substs),
ty::TyGenerator(def_id, substs, movability) => {
DefiningTy::Generator(def_id, substs, movability)
@ -587,8 +615,8 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
let closure_base_def_id = tcx.closure_base_def_id(self.mir_def_id);
let identity_substs = Substs::identity_for_item(gcx, closure_base_def_id);
let fr_substs = match defining_ty {
DefiningTy::Closure(_, ClosureSubsts { ref substs }) |
DefiningTy::Generator(_, GeneratorSubsts { ref substs }, _) => {
DefiningTy::Closure(_, ClosureSubsts { ref substs })
| DefiningTy::Generator(_, GeneratorSubsts { ref substs }, _) => {
// In the case of closures, we rely on the fact that
// the first N elements in the ClosureSubsts are
// inherited from the `closure_base_def_id`.
@ -726,8 +754,7 @@ impl UniversalRegionRelations {
fn relate_universal_regions(&mut self, fr_a: RegionVid, fr_b: RegionVid) {
debug!(
"relate_universal_regions: fr_a={:?} outlives fr_b={:?}",
fr_a,
fr_b
fr_a, fr_b
);
self.outlives.add(fr_a, fr_b);
self.inverse_outlives.add(fr_b, fr_a);
@ -780,8 +807,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'gcx, 'tcx> {
{
debug!(
"replace_bound_regions_with_nll_infer_vars(value={:?}, all_outlive_scope={:?})",
value,
all_outlive_scope,
value, all_outlive_scope,
);
let (value, _map) = self.tcx.replace_late_bound_regions(value, |br| {
let liberated_region = self.tcx.mk_region(ty::ReFree(ty::FreeRegion {
@ -790,7 +816,10 @@ impl<'cx, 'gcx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'gcx, 'tcx> {
}));
let region_vid = self.next_nll_region_var(origin);
indices.insert_late_bound_region(liberated_region, region_vid.to_region_vid());
debug!("liberated_region={:?} => {:?}", liberated_region, region_vid);
debug!(
"liberated_region={:?} => {:?}",
liberated_region, region_vid
);
region_vid
});
value
@ -803,9 +832,8 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
/// in later and instantiate the late-bound regions, and then we
/// insert the `ReFree` version of those into the map as
/// well. These are used for error reporting.
fn insert_late_bound_region(&mut self, r: ty::Region<'tcx>,
vid: ty::RegionVid)
{
fn insert_late_bound_region(&mut self, r: ty::Region<'tcx>, vid: ty::RegionVid) {
debug!("insert_late_bound_region({:?}, {:?})", r, vid);
self.indices.insert(r, vid);
}
@ -821,9 +849,9 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
if let ty::ReVar(..) = r {
r.to_region_vid()
} else {
*self.indices.get(&r).unwrap_or_else(|| {
bug!("cannot convert `{:?}` to a region vid", r)
})
*self.indices
.get(&r)
.unwrap_or_else(|| bug!("cannot convert `{:?}` to a region vid", r))
}
}

1
src/librustc_mir/build/mod.rs
View file

@ -534,6 +534,7 @@ fn construct_fn<'a, 'gcx, 'tcx, A>(hir: Cx<'a, 'gcx, 'tcx>,
};
let mut decl = UpvarDecl {
debug_name: keywords::Invalid.name(),
var_hir_id: ClearCrossCrate::Set(var_hir_id),
by_ref,
mutability: Mutability::Not,
};

2
src/test/compile-fail/borrowck/borrowck-describe-lvalue.rs
View file

@ -302,7 +302,7 @@ fn main() {
// FIXME(#49824) -- the free region error below should probably not be there
let mut x = 0;
|| {
|| { //[mir]~ ERROR free region `` does not outlive
|| { //[mir]~ ERROR unsatisfied lifetime constraints
let y = &mut x;
&mut x; //[ast]~ ERROR cannot borrow `**x` as mutable more than once at a time
//[mir]~^ ERROR cannot borrow `x` as mutable more than once at a time

2
src/test/compile-fail/mir_check_cast_closure.rs
View file

@ -14,7 +14,7 @@
fn bar<'a, 'b>() -> fn(&'a u32, &'b u32) -> &'a u32 {
let g: fn(_, _) -> _ = |_x, y| y;
//~^ ERROR free region `'b` does not outlive free region `'a`
//~^ ERROR unsatisfied lifetime constraints
g
//~^ WARNING not reporting region error due to nll
}

2
src/test/compile-fail/mir_check_cast_reify.rs
View file

@ -45,7 +45,7 @@ fn bar<'a>(x: &'a u32) -> &'static u32 {
// as part of checking the `ReifyFnPointer`.
let f: fn(_) -> _ = foo;
//~^ WARNING not reporting region error due to nll
//~| ERROR free region `'a` does not outlive free region `'static`
//~| ERROR unsatisfied lifetime constraints
f(x)
}

2
src/test/compile-fail/mir_check_cast_unsafe_fn.rs
View file

@ -17,7 +17,7 @@ fn bar<'a>(input: &'a u32, f: fn(&'a u32) -> &'a u32) -> &'static u32 {
// in `g`. These are related via the `UnsafeFnPointer` cast.
let g: unsafe fn(_) -> _ = f;
//~^ WARNING not reporting region error due to nll
//~| ERROR free region `'a` does not outlive free region `'static`
//~| ERROR unsatisfied lifetime constraints
unsafe { g(input) }
}

3
src/test/compile-fail/mir_check_cast_unsize.rs
View file

@ -15,8 +15,7 @@
use std::fmt::Debug;
fn bar<'a>(x: &'a u32) -> &'static dyn Debug {
//~^ ERROR free region `'a` does not outlive free region `'static`
x
x //~ ERROR unsatisfied lifetime constraints
//~^ WARNING not reporting region error due to nll
}

2
src/test/compile-fail/regions-static-bound.rs
View file

@ -18,7 +18,7 @@ fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static ()
fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
t //[ll]~ ERROR E0312
//[nll]~^ WARNING not reporting region error due to nll
//[nll]~| ERROR free region `'a` does not outlive free region `'static`
//[nll]~| ERROR unsatisfied lifetime constraints
}
fn error(u: &(), v: &()) {

10
src/test/ui/borrowck/issue-45983.nll.stderr
View file

@ -4,11 +4,15 @@ warning: not reporting region error due to nll
LL | give_any(|y| x = Some(y));
| ^
error: free region `` does not outlive free region `'_#2r`
--> $DIR/issue-45983.rs:17:27
error: unsatisfied lifetime constraints
--> $DIR/issue-45983.rs:17:18
|
LL | let x = None;
| - lifetime `'2` appears in the type of `x`
LL | give_any(|y| x = Some(y));
| ^
| - ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
| |
| lifetime `'1` appears in this argument
error[E0594]: cannot assign to immutable item `x`
--> $DIR/issue-45983.rs:17:18

10
src/test/ui/borrowck/issue-7573.nll.stderr
View file

@ -4,11 +4,17 @@ warning: not reporting region error due to nll
LL | let mut lines_to_use: Vec<&CrateId> = Vec::new();
| ^
error: free region `` does not outlive free region `'_#2r`
error: unsatisfied lifetime constraints
--> $DIR/issue-7573.rs:32:9
|
LL | let mut lines_to_use: Vec<&CrateId> = Vec::new();
| ---------------- lifetime `'2` appears in the type of `lines_to_use`
LL | //~^ NOTE cannot infer an appropriate lifetime
LL | let push_id = |installed_id: &CrateId| {
| ------------ lifetime `'1` appears in this argument
...
LL | lines_to_use.push(installed_id);
| ^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`
error: aborting due to previous error

10
src/test/ui/borrowck/regions-escape-bound-fn-2.nll.stderr
View file

@ -4,11 +4,15 @@ warning: not reporting region error due to nll
LL | with_int(|y| x = Some(y));
| ^
error: free region `` does not outlive free region `'_#2r`
--> $DIR/regions-escape-bound-fn-2.rs:18:27
error: unsatisfied lifetime constraints
--> $DIR/regions-escape-bound-fn-2.rs:18:18
|
LL | let mut x = None;
| ----- lifetime `'2` appears in the type of `x`
LL | with_int(|y| x = Some(y));
| ^
| - ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
| |
| lifetime `'1` appears in this argument
error: aborting due to previous error

10
src/test/ui/borrowck/regions-escape-bound-fn.nll.stderr
View file

@ -4,11 +4,15 @@ warning: not reporting region error due to nll
LL | with_int(|y| x = Some(y));
| ^^^^^^^
error: free region `` does not outlive free region `'_#2r`
--> $DIR/regions-escape-bound-fn.rs:18:27
error: unsatisfied lifetime constraints
--> $DIR/regions-escape-bound-fn.rs:18:18
|
LL | let mut x: Option<&isize> = None;
| ----- lifetime `'2` appears in the type of `x`
LL | with_int(|y| x = Some(y));
| ^
| - ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
| |
| lifetime `'1` appears in this argument
error: aborting due to previous error

10
src/test/ui/borrowck/regions-escape-unboxed-closure.nll.stderr
View file

@ -4,11 +4,15 @@ warning: not reporting region error due to nll
LL | with_int(&mut |y| x = Some(y));
| ^^^^^^^
error: free region `` does not outlive free region `'_#2r`
--> $DIR/regions-escape-unboxed-closure.rs:16:32
error: unsatisfied lifetime constraints
--> $DIR/regions-escape-unboxed-closure.rs:16:23
|
LL | let mut x: Option<&isize> = None;
| ----- lifetime `'2` appears in the type of `x`
LL | with_int(&mut |y| x = Some(y));
| ^
| - ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
| |
| lifetime `'1` appears in this argument
error: aborting due to previous error

32
src/test/ui/closure-expected-type/expect-region-supply-region.nll.stderr
View file

@ -22,23 +22,37 @@ warning: not reporting region error due to nll
LL | f = Some(x);
| ^^^^^^^
error: free region `` does not outlive free region `'_#2r`
--> $DIR/expect-region-supply-region.rs:28:18
error: unsatisfied lifetime constraints
--> $DIR/expect-region-supply-region.rs:28:9
|
LL | let mut f: Option<&u32> = None;
| ----- lifetime `'2` appears in the type of `f`
LL | closure_expecting_bound(|x| {
| - lifetime `'1` appears in this argument
LL | f = Some(x); //~ ERROR borrowed data cannot be stored outside of its closure
| ^
| ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
error: free region `` does not outlive free region `'_#2r`
--> $DIR/expect-region-supply-region.rs:38:18
error: unsatisfied lifetime constraints
--> $DIR/expect-region-supply-region.rs:38:9
|
LL | let mut f: Option<&u32> = None;
| ----- lifetime `'2` appears in the type of `f`
LL | closure_expecting_bound(|x: &u32| {
| - lifetime `'1` appears in this argument
LL | f = Some(x); //~ ERROR borrowed data cannot be stored outside of its closure
| ^
| ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
error: free region `` does not outlive free region `'_#2r`
--> $DIR/expect-region-supply-region.rs:52:18
error: unsatisfied lifetime constraints
--> $DIR/expect-region-supply-region.rs:52:9
|
LL | let mut f: Option<&u32> = None;
| ----- lifetime `'2` appears in the type of `f`
...
LL | closure_expecting_bound(|x: &'x u32| {
| - lifetime `'1` appears in this argument
...
LL | f = Some(x);
| ^
| ^^^^^^^^^^^ free region requires that `'1` must outlive `'2`
error: aborting due to 3 previous errors

8
src/test/ui/error-codes/E0621-does-not-trigger-for-closures.nll.stderr
View file

@ -4,11 +4,15 @@ warning: not reporting region error due to nll
LL | invoke(&x, |a, b| if a > b { a } else { b }); //~ ERROR E0495
| ^^^^^^
error: free region `` does not outlive free region `'_#2r`
error: unsatisfied lifetime constraints
--> $DIR/E0621-does-not-trigger-for-closures.rs:25:26
|
LL | invoke(&x, |a, b| if a > b { a } else { b }); //~ ERROR E0495
| ^^^^^
| ----------^^^^^-----------------
| | | |
| | | free region requires that `'1` must outlive `'2`
| | lifetime `'1` appears in this argument
| lifetime `'2` appears in return type
error: aborting due to previous error

10
src/test/ui/impl-trait/static-return-lifetime-infered.nll.stderr
View file

@ -10,17 +10,19 @@ warning: not reporting region error due to nll
LL | self.x.iter().map(|a| a.0)
| ^^^^
error: free region `` does not outlive free region `'static`
error: unsatisfied lifetime constraints
--> $DIR/static-return-lifetime-infered.rs:17:9
|
LL | fn iter_values_anon(&self) -> impl Iterator<Item=u32> {
| ----- lifetime `'1` appears in this argument
LL | self.x.iter().map(|a| a.0)
| ^^^^^^^^^^^^^
| ^^^^^^ cast requires that `'1` must outlive `'static`
error: free region `'a` does not outlive free region `'static`
error: unsatisfied lifetime constraints
--> $DIR/static-return-lifetime-infered.rs:21:9
|
LL | self.x.iter().map(|a| a.0)
| ^^^^^^^^^^^^^
| ^^^^^^ cast requires that `'a` must outlive `'static`
error: aborting due to 2 previous errors

4
src/test/ui/in-band-lifetimes/impl/dyn-trait.nll.stderr
View file

@ -4,11 +4,11 @@ warning: not reporting region error due to nll
LL | static_val(x); //~ ERROR cannot infer
| ^
error: free region `'a` does not outlive free region `'static`
error: unsatisfied lifetime constraints
--> $DIR/dyn-trait.rs:32:5
|
LL | static_val(x); //~ ERROR cannot infer
| ^^^^^^^^^^^^^
| ^^^^^^^^^^^^^ argument requires that `'a` must outlive `'static`
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/escape-argument-callee.rs
View file

@ -34,7 +34,7 @@ fn test() {
{
let y = 22;
let mut closure = expect_sig(|p, y| *p = y);
//~^ ERROR does not outlive free region
//~^ ERROR
//~| WARNING not reporting region error due to nll
closure(&mut p, &y);
}

7
src/test/ui/nll/closure-requirements/escape-argument-callee.stderr
View file

@ -4,11 +4,14 @@ warning: not reporting region error due to nll
LL | let mut closure = expect_sig(|p, y| *p = y);
| ^
error: free region `ReFree(DefId(0/1:9 ~ escape_argument_callee[317d]::test[0]::{{closure}}[0]), BrAnon(3))` does not outlive free region `ReFree(DefId(0/1:9 ~ escape_argument_callee[317d]::test[0]::{{closure}}[0]), BrAnon(2))`
error: unsatisfied lifetime constraints
--> $DIR/escape-argument-callee.rs:36:45
|
LL | let mut closure = expect_sig(|p, y| *p = y);
| ^^^^^^
| - - ^^^^^^ free region requires that `'1` must outlive `'2`
| | |
| | lifetime `'1` appears in this argument
| lifetime `'2` appears in this argument
note: No external requirements
--> $DIR/escape-argument-callee.rs:36:38

3
src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.rs
View file

@ -54,8 +54,7 @@ fn supply<'a, 'b, 'c>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>, cell_c: Cell
// Only works if 'x: 'y:
let p = x.get();
//~^ WARN not reporting region error due to nll
//~| ERROR does not outlive free region
demand_y(x, y, p)
demand_y(x, y, p) //~ ERROR
},
);
}

16
src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
View file

@ -4,11 +4,16 @@ warning: not reporting region error due to nll
LL | let p = x.get();
| ^^^^^^^
error: free region `ReFree(DefId(0/1:20 ~ propagate_approximated_fail_no_postdom[317d]::supply[0]::{{closure}}[0]), BrAnon(1))` does not outlive free region `ReFree(DefId(0/1:20 ~ propagate_approximated_fail_no_postdom[317d]::supply[0]::{{closure}}[0]), BrAnon(2))`
--> $DIR/propagate-approximated-fail-no-postdom.rs:55:17
error: unsatisfied lifetime constraints
--> $DIR/propagate-approximated-fail-no-postdom.rs:57:13
|
LL | let p = x.get();
| ^
LL | |_outlives1, _outlives2, _outlives3, x, y| {
| ---------- ---------- lifetime `'2` appears in this argument
| |
| lifetime `'1` appears in this argument
...
LL | demand_y(x, y, p) //~ ERROR
| ^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`
note: No external requirements
--> $DIR/propagate-approximated-fail-no-postdom.rs:53:9
@ -17,8 +22,7 @@ LL | / |_outlives1, _outlives2, _outlives3, x, y| {
LL | | // Only works if 'x: 'y:
LL | | let p = x.get();
LL | | //~^ WARN not reporting region error due to nll
LL | | //~| ERROR does not outlive free region
LL | | demand_y(x, y, p)
LL | | demand_y(x, y, p) //~ ERROR
LL | | },
| |_________^
|

2
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.rs
View file

@ -31,7 +31,7 @@ fn case1() {
foo(cell, |cell_a, cell_x| {
//~^ WARNING not reporting region error due to nll
cell_a.set(cell_x.get()); // forces 'x: 'a, error in closure
//~^ ERROR argument requires that data must outlive free region
//~^ ERROR
})
}

13
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
View file

@ -4,11 +4,16 @@ warning: not reporting region error due to nll
LL | foo(cell, |cell_a, cell_x| {
| ^^^
error: argument requires that data must outlive free region `'_#1r`
--> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:33:20
error: unsatisfied lifetime constraints
--> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:33:9
|
LL | foo(cell, |cell_a, cell_x| {
| ------ ------ lifetime `'1` appears in this argument
| |
| lifetime `'2` appears in this argument
LL | //~^ WARNING not reporting region error due to nll
LL | cell_a.set(cell_x.get()); // forces 'x: 'a, error in closure
| ^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`
note: No external requirements
--> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:31:15
@ -17,7 +22,7 @@ LL | foo(cell, |cell_a, cell_x| {
| _______________^
LL | | //~^ WARNING not reporting region error due to nll
LL | | cell_a.set(cell_x.get()); // forces 'x: 'a, error in closure
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | | })
| |_____^
|

2
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.rs
View file

@ -43,7 +43,7 @@ fn demand_y<'x, 'y>(_cell_x: &Cell<&'x u32>, _cell_y: &Cell<&'y u32>, _y: &'y u3
#[rustc_regions]
fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
//~^ ERROR argument requires that data must outlive free region
//~^ ERROR
// Only works if 'x: 'y:
demand_y(x, y, x.get()) //~ WARNING not reporting region error due to nll

10
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
View file

@ -9,7 +9,7 @@ note: External requirements
|
LL | establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
| _______________________________________________^
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | |
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get()) //~ WARNING not reporting region error due to nll
@ -23,23 +23,23 @@ LL | | });
= note: number of external vids: 2
= note: where '_#1r: '_#0r
error: argument requires that data must outlive free region `ReStatic`
error: unsatisfied lifetime constraints
--> $DIR/propagate-approximated-shorter-to-static-no-bound.rs:45:5
|
LL | / establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | |
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get()) //~ WARNING not reporting region error due to nll
LL | | });
| |______^
| |______^ argument requires that `'a` must outlive `'static`
note: No external requirements
--> $DIR/propagate-approximated-shorter-to-static-no-bound.rs:44:1
|
LL | / fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
LL | | establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | |
... |
LL | | });

2
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.rs
View file

@ -46,7 +46,7 @@ fn demand_y<'x, 'y>(_cell_x: &Cell<&'x u32>, _cell_y: &Cell<&'y u32>, _y: &'y u3
#[rustc_regions]
fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
//~^ ERROR argument requires that data must outlive free region
//~^ ERROR
// Only works if 'x: 'y:
demand_y(x, y, x.get())
//~^ WARNING not reporting region error due to nll

10
src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
View file

@ -9,7 +9,7 @@ note: External requirements
|
LL | establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
| _______________________________________________^
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get())
LL | | //~^ WARNING not reporting region error due to nll
@ -23,23 +23,23 @@ LL | | });
= note: number of external vids: 3
= note: where '_#1r: '_#0r
error: argument requires that data must outlive free region `ReStatic`
error: unsatisfied lifetime constraints
--> $DIR/propagate-approximated-shorter-to-static-wrong-bound.rs:48:5
|
LL | / establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get())
LL | | //~^ WARNING not reporting region error due to nll
LL | | });
| |______^
| |______^ argument requires that `'a` must outlive `'static`
note: No external requirements
--> $DIR/propagate-approximated-shorter-to-static-wrong-bound.rs:47:1
|
LL | / fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
LL | | establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
LL | | //~^ ERROR argument requires that data must outlive free region
LL | | //~^ ERROR
LL | | // Only works if 'x: 'y:
... |
LL | | });

2
src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs
View file

@ -46,7 +46,7 @@ fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
// Only works if 'x: 'y:
demand_y(x, y, x.get())
//~^ WARN not reporting region error due to nll
//~| ERROR argument requires that data must outlive free region
//~| ERROR
});
}

11
src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
View file

@ -4,11 +4,16 @@ warning: not reporting region error due to nll
LL | demand_y(x, y, x.get())
| ^^^^^^^^^^^^^^^^^^^^^^^
error: argument requires that data must outlive free region `ReFree(DefId(0/1:18 ~ propagate_fail_to_approximate_longer_no_bounds[317d]::supply[0]::{{closure}}[0]), BrAnon(2))`
error: unsatisfied lifetime constraints
--> $DIR/propagate-fail-to-approximate-longer-no-bounds.rs:47:9
|
LL | establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
| --------- - lifetime `'1` appears in this argument
| |
| lifetime `'2` appears in this argument
LL | // Only works if 'x: 'y:
LL | demand_y(x, y, x.get())
| ^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`
note: No external requirements
--> $DIR/propagate-fail-to-approximate-longer-no-bounds.rs:45:47
@ -18,7 +23,7 @@ LL | establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get())
LL | | //~^ WARN not reporting region error due to nll
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | });
| |_____^
|

2
src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.rs
View file

@ -50,7 +50,7 @@ fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) {
// Only works if 'x: 'y:
demand_y(x, y, x.get())
//~^ WARN not reporting region error due to nll
//~| ERROR does not outlive free region
//~| ERROR
});
}

13
src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
View file

@ -4,11 +4,16 @@ warning: not reporting region error due to nll
LL | demand_y(x, y, x.get())
| ^^^^^^^^^^^^^^^^^^^^^^^
error: free region `ReFree(DefId(0/1:18 ~ propagate_fail_to_approximate_longer_wrong_bounds[317d]::supply[0]::{{closure}}[0]), BrAnon(2))` does not outlive free region `ReFree(DefId(0/1:18 ~ propagate_fail_to_approximate_longer_wrong_bounds[317d]::supply[0]::{{closure}}[0]), BrAnon(4))`
--> $DIR/propagate-fail-to-approximate-longer-wrong-bounds.rs:51:18
error: unsatisfied lifetime constraints
--> $DIR/propagate-fail-to-approximate-longer-wrong-bounds.rs:51:9
|
LL | establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y| {
| ---------- ---------- lifetime `'2` appears in this argument
| |
| lifetime `'1` appears in this argument
LL | // Only works if 'x: 'y:
LL | demand_y(x, y, x.get())
| ^
| ^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'1` must outlive `'2`
note: No external requirements
--> $DIR/propagate-fail-to-approximate-longer-wrong-bounds.rs:49:47
@ -18,7 +23,7 @@ LL | establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x,
LL | | // Only works if 'x: 'y:
LL | | demand_y(x, y, x.get())
LL | | //~^ WARN not reporting region error due to nll
LL | | //~| ERROR does not outlive free region
LL | | //~| ERROR
LL | | });
| |_____^
|

2
src/test/ui/nll/closure-requirements/region-lbr-named-does-not-outlive-static.rs
View file

@ -18,7 +18,7 @@
fn foo<'a>(x: &'a u32) -> &'static u32 {
&*x
//~^ WARN not reporting region error due to nll
//~| ERROR does not outlive free region
//~| ERROR
}
fn main() { }

4
src/test/ui/nll/closure-requirements/region-lbr-named-does-not-outlive-static.stderr
View file

@ -4,11 +4,11 @@ warning: not reporting region error due to nll
LL | &*x
| ^^^
error: free region `ReFree(DefId(0/0:3 ~ region_lbr_named_does_not_outlive_static[317d]::foo[0]), BrNamed(crate0:DefIndex(1:9), 'a))` does not outlive free region `ReStatic`
error: unsatisfied lifetime constraints
--> $DIR/region-lbr-named-does-not-outlive-static.rs:19:5
|
LL | &*x
| ^^^
| ^^^ free region requires that `'a` must outlive `'static`
error: aborting due to previous error

2
src/test/ui/nll/closure-requirements/return-wrong-bound-region.rs
View file

@ -20,7 +20,7 @@
fn test() {
expect_sig(|a, b| b); // ought to return `a`
//~^ WARN not reporting region error due to nll
//~| ERROR does not outlive free region
//~| ERROR
}
fn expect_sig<F>(f: F) -> F

9
src/test/ui/nll/closure-requirements/return-wrong-bound-region.stderr
View file

@ -4,11 +4,14 @@ warning: not reporting region error due to nll
LL | expect_sig(|a, b| b); // ought to return `a`
| ^
error: free region `ReFree(DefId(0/1:9 ~ return_wrong_bound_region[317d]::test[0]::{{closure}}[0]), BrAnon(2))` does not outlive free region `ReFree(DefId(0/1:9 ~ return_wrong_bound_region[317d]::test[0]::{{closure}}[0]), BrAnon(1))`
error: unsatisfied lifetime constraints
--> $DIR/return-wrong-bound-region.rs:21:23
|
LL | expect_sig(|a, b| b); // ought to return `a`
| ^
| - - ^ free region requires that `'1` must outlive `'2`
| | |
| | lifetime `'1` appears in this argument
| lifetime `'2` appears in this argument
note: No external requirements
--> $DIR/return-wrong-bound-region.rs:21:16
@ -27,7 +30,7 @@ note: No external requirements
LL | / fn test() {
LL | | expect_sig(|a, b| b); // ought to return `a`
LL | | //~^ WARN not reporting region error due to nll
LL | | //~| ERROR does not outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|

2
src/test/ui/nll/issue-48238.rs
View file

@ -18,5 +18,5 @@ fn use_val<'a>(val: &'a u8) -> &'a u8 {
fn main() {
let orig: u8 = 5;
move || use_val(&orig); //~ ERROR free region `` does not outlive free region `'_#1r`
move || use_val(&orig); //~ ERROR
}

12
src/test/ui/nll/issue-48238.stderr
View file

@ -1,8 +1,12 @@
error: free region `` does not outlive free region `'_#1r`
--> $DIR/issue-48238.rs:21:21
error: unsatisfied lifetime constraints
--> $DIR/issue-48238.rs:21:13
|
LL | move || use_val(&orig); //~ ERROR free region `` does not outlive free region `'_#1r`
| ^^^^^
LL | move || use_val(&orig); //~ ERROR
| --------^^^^^^^^^^^^^^
| | |
| | argument requires that `'1` must outlive `'2`
| lifetime `'1` represents the closure body
| lifetime `'2` appears in return type
error: aborting due to previous error

2
src/test/ui/nll/issue-50716.rs
View file

@ -22,7 +22,7 @@ where
for<'b> &'b T: A,
<&'static T as A>::X: Sized
{
let _x = *s; //~ ERROR assignment requires that data must outlive free region `'static`
let _x = *s; //~ ERROR
}
fn main() {}

6
src/test/ui/nll/issue-50716.stderr
View file

@ -1,8 +1,8 @@
error: assignment requires that data must outlive free region `'static`
error: unsatisfied lifetime constraints
--> $DIR/issue-50716.rs:25:14
|
LL | let _x = *s; //~ ERROR assignment requires that data must outlive free region `'static`
| ^^
LL | let _x = *s; //~ ERROR
| ^^ assignment requires that `'a` must outlive `'static`
error: aborting due to previous error

6
src/test/ui/nll/ty-outlives/projection-one-region-closure.rs
View file

@ -55,7 +55,7 @@ where
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR the parameter type `T` may not live long enough
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]
@ -67,7 +67,7 @@ where
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR the parameter type `T` may not live long enough
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]
@ -89,7 +89,7 @@ where
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR the parameter type `T` may not live long enough
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]

18
src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr
View file

@ -40,11 +40,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
|
= help: consider adding an explicit lifetime bound `T: ReFree(DefId(0/0:8 ~ projection_one_region_closure[317d]::no_relationships_late[0]), BrNamed(crate0:DefIndex(1:16), 'a))`...
error: argument requires that data must outlive free region `ReFree(DefId(0/0:8 ~ projection_one_region_closure[317d]::no_relationships_late[0]), BrNamed(crate0:DefIndex(1:16), 'a))`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-closure.rs:55:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-closure.rs:51:1
@ -54,7 +54,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | {
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|
@ -88,11 +88,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
|
= help: consider adding an explicit lifetime bound `T: ReEarlyBound(0, 'a)`...
error: argument requires that data must outlive free region `ReEarlyBound(0, 'a)`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-closure.rs:67:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-closure.rs:62:1
@ -102,7 +102,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | 'a: 'a,
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|
@ -137,11 +137,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
|
= help: consider adding an explicit lifetime bound `T: ReEarlyBound(0, 'a)`...
error: argument requires that data must outlive free region `ReEarlyBound(0, 'a)`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-closure.rs:89:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-closure.rs:74:1
@ -151,7 +151,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | T::AssocType: 'a,
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|

6
src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.rs
View file

@ -46,7 +46,7 @@ where
{
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]
@ -57,7 +57,7 @@ where
{
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]
@ -78,7 +78,7 @@ where
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]

18
src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr
View file

@ -31,11 +31,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
= note: number of external vids: 3
= note: where '_#1r: '_#2r
error: argument requires that data must outlive free region `ReFree(DefId(0/0:8 ~ projection_one_region_trait_bound_closure[317d]::no_relationships_late[0]), BrNamed(crate0:DefIndex(1:16), 'a))`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-trait-bound-closure.rs:47:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-trait-bound-closure.rs:43:1
@ -45,7 +45,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | {
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|
@ -70,11 +70,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
= note: number of external vids: 4
= note: where '_#2r: '_#3r
error: argument requires that data must outlive free region `ReEarlyBound(0, 'a)`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-trait-bound-closure.rs:58:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-trait-bound-closure.rs:53:1
@ -84,7 +84,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | 'a: 'a,
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|
@ -110,11 +110,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
= note: number of external vids: 4
= note: where '_#2r: '_#3r
error: argument requires that data must outlive free region `ReEarlyBound(0, 'a)`
error: unsatisfied lifetime constraints
--> $DIR/projection-one-region-trait-bound-closure.rs:79:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-one-region-trait-bound-closure.rs:64:1
@ -124,7 +124,7 @@ LL | | where
LL | | T: Anything<'b>,
LL | | T::AssocType: 'a,
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|

2
src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.rs
View file

@ -107,7 +107,7 @@ where
{
with_signature(cell, t, |cell, t| require(cell, t));
//~^ WARNING not reporting region error due to nll
//~| ERROR argument requires that data must outlive free region
//~| ERROR
}
#[rustc_regions]

6
src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr
View file

@ -239,11 +239,11 @@ LL | with_signature(cell, t, |cell, t| require(cell, t));
= note: number of external vids: 3
= note: where <T as Anything<ReClosureBound('_#1r), ReClosureBound('_#1r)>>::AssocType: '_#2r
error: argument requires that data must outlive free region `ReFree(DefId(0/0:13 ~ projection_two_region_trait_bound_closure[317d]::two_regions[0]), BrNamed(crate0:DefIndex(1:43), 'a))`
error: unsatisfied lifetime constraints
--> $DIR/projection-two-region-trait-bound-closure.rs:108:5
|
LL | with_signature(cell, t, |cell, t| require(cell, t));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'b` must outlive `'a`
note: No external requirements
--> $DIR/projection-two-region-trait-bound-closure.rs:104:1
@ -253,7 +253,7 @@ LL | | where
LL | | T: Anything<'b, 'b>,
LL | | {
... |
LL | | //~| ERROR argument requires that data must outlive free region
LL | | //~| ERROR
LL | | }
| |_^
|

7
src/test/ui/underscore-lifetime/dyn-trait-underscore.nll.stderr
View file

@ -22,11 +22,14 @@ warning: not reporting region error due to nll
LL | Box::new(items.iter()) //~ ERROR cannot infer an appropriate lifetime
| ^^^^^^^^^^^^^^^^^^^^^^
error: cast requires that data must outlive free region `'static`
error: unsatisfied lifetime constraints
--> $DIR/dyn-trait-underscore.rs:18:5
|
LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
| ----- lifetime `'1` appears in this argument
LL | // ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
LL | Box::new(items.iter()) //~ ERROR cannot infer an appropriate lifetime
| ^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^ cast requires that `'1` must outlive `'static`
error: aborting due to previous error