// option. This file may not be copied, modified, or distributed
// except according to those terms.
-use borrow_check::nll::ConstraintDescription;
-use borrow_check::nll::constraints::{OutlivesConstraint};
+use borrow_check::nll::constraints::OutlivesConstraint;
use borrow_check::nll::region_infer::RegionInferenceContext;
use borrow_check::nll::type_check::Locations;
use borrow_check::nll::universal_regions::DefiningTy;
-use util::borrowck_errors::{BorrowckErrors, Origin};
+use borrow_check::nll::ConstraintDescription;
use rustc::hir::def_id::DefId;
use rustc::infer::error_reporting::nice_region_error::NiceRegionError;
use rustc::infer::InferCtxt;
use rustc_data_structures::indexed_vec::IndexVec;
use rustc_errors::{Diagnostic, DiagnosticBuilder};
use std::collections::VecDeque;
+use syntax::errors::Applicability;
use syntax::symbol::keywords;
use syntax_pos::Span;
-use syntax::errors::Applicability;
+use util::borrowck_errors::{BorrowckErrors, Origin};
mod region_name;
mod var_name;
debug!("best_blame_constraint(from_region={:?})", from_region);
// Find all paths
- let (path, target_region) = self
- .find_constraint_paths_between_regions(from_region, target_test)
- .unwrap();
+ let (path, target_region) =
+ self.find_constraint_paths_between_regions(from_region, target_test)
+ .unwrap();
debug!(
"best_blame_constraint: path={:#?}",
path.iter()
);
// Classify each of the constraints along the path.
- let mut categorized_path: Vec<(ConstraintCategory, bool, Span)> = path
- .iter()
+ let mut categorized_path: Vec<(ConstraintCategory, bool, Span)> = path.iter()
.map(|constraint| {
if constraint.category == ConstraintCategory::ClosureBounds {
self.retrieve_closure_constraint_info(mir, &constraint)
| ConstraintCategory::Boring
| ConstraintCategory::BoringNoLocation
| ConstraintCategory::Internal => false,
- ConstraintCategory::TypeAnnotation
- | ConstraintCategory::Return => true,
+ ConstraintCategory::TypeAnnotation | ConstraintCategory::Return => true,
_ => constraint_sup_scc != target_scc,
}
});
if let Some(i) = best_choice {
- return categorized_path[i]
+ return categorized_path[i];
}
// If that search fails, that is.. unusual. Maybe everything
// enqueue any regions we find, keeping track of how we
// reached them.
let fr_static = self.universal_regions.fr_static;
- for constraint in self.constraint_graph.outgoing_edges(r,
- &self.constraints,
- fr_static) {
+ for constraint in self.constraint_graph
+ .outgoing_edges(r, &self.constraints, fr_static)
+ {
assert_eq!(constraint.sup, r);
let sub_region = constraint.sub;
if let Trace::NotVisited = context[sub_region] {
) {
debug!("report_error(fr={:?}, outlived_fr={:?})", fr, outlived_fr);
- let (category, _, span) = self.best_blame_constraint(
- mir,
- fr,
- |r| r == outlived_fr
- );
+ let (category, _, span) = self.best_blame_constraint(mir, fr, |r| r == outlived_fr);
// Check if we can use one of the "nice region errors".
if let (Some(f), Some(o)) = (self.to_error_region(fr), self.to_error_region(outlived_fr)) {
self.universal_regions.is_local_free_region(outlived_fr),
);
- debug!("report_error: fr_is_local={:?} outlived_fr_is_local={:?} category={:?}",
- fr_is_local, outlived_fr_is_local, category);
+ debug!(
+ "report_error: fr_is_local={:?} outlived_fr_is_local={:?} category={:?}",
+ fr_is_local, outlived_fr_is_local, category
+ );
match (category, fr_is_local, outlived_fr_is_local) {
- (ConstraintCategory::Return, true, false) if self.is_closure_fn_mut(infcx, fr) =>
- self.report_fnmut_error(mir, infcx, mir_def_id, fr, outlived_fr, span,
- errors_buffer),
- (ConstraintCategory::Assignment, true, false) |
- (ConstraintCategory::CallArgument, true, false) =>
- self.report_escaping_data_error(mir, infcx, mir_def_id, fr, outlived_fr,
- category, span, errors_buffer),
- _ =>
- self.report_general_error(mir, infcx, mir_def_id, fr, fr_is_local,
- outlived_fr, outlived_fr_is_local,
- category, span, errors_buffer),
+ (ConstraintCategory::Return, true, false) if self.is_closure_fn_mut(infcx, fr) => {
+ self.report_fnmut_error(
+ mir,
+ infcx,
+ mir_def_id,
+ fr,
+ outlived_fr,
+ span,
+ errors_buffer,
+ )
+ }
+ (ConstraintCategory::Assignment, true, false)
+ | (ConstraintCategory::CallArgument, true, false) => self.report_escaping_data_error(
+ mir,
+ infcx,
+ mir_def_id,
+ fr,
+ outlived_fr,
+ category,
+ span,
+ errors_buffer,
+ ),
+ _ => self.report_general_error(
+ mir,
+ infcx,
+ mir_def_id,
+ fr,
+ fr_is_local,
+ outlived_fr,
+ outlived_fr_is_local,
+ category,
+ span,
+ errors_buffer,
+ ),
};
}
span: Span,
errors_buffer: &mut Vec<Diagnostic>,
) {
- let mut diag = infcx.tcx.sess.struct_span_err(
- span,
- "captured variable cannot escape `FnMut` closure body",
- );
+ let mut diag = infcx
+ .tcx
+ .sess
+ .struct_span_err(span, "captured variable cannot escape `FnMut` closure body");
// We should check if the return type of this closure is in fact a closure - in that
// case, we can special case the error further.
"returns a reference to a captured variable which escapes the closure body"
};
- diag.span_label(
- span,
- message,
- );
+ diag.span_label(span, message);
- match self.give_region_a_name(infcx, mir, mir_def_id, outlived_fr, &mut 1).source {
- RegionNameSource::NamedEarlyBoundRegion(fr_span) |
- RegionNameSource::NamedFreeRegion(fr_span) |
- RegionNameSource::SynthesizedFreeEnvRegion(fr_span, _) |
- RegionNameSource::CannotMatchHirTy(fr_span, _) |
- RegionNameSource::MatchedHirTy(fr_span) |
- RegionNameSource::MatchedAdtAndSegment(fr_span) |
- RegionNameSource::AnonRegionFromUpvar(fr_span, _) |
- RegionNameSource::AnonRegionFromOutput(fr_span, _, _) => {
+ match self.give_region_a_name(infcx, mir, mir_def_id, outlived_fr, &mut 1)
+ .source
+ {
+ RegionNameSource::NamedEarlyBoundRegion(fr_span)
+ | RegionNameSource::NamedFreeRegion(fr_span)
+ | RegionNameSource::SynthesizedFreeEnvRegion(fr_span, _)
+ | RegionNameSource::CannotMatchHirTy(fr_span, _)
+ | RegionNameSource::MatchedHirTy(fr_span)
+ | RegionNameSource::MatchedAdtAndSegment(fr_span)
+ | RegionNameSource::AnonRegionFromUpvar(fr_span, _)
+ | RegionNameSource::AnonRegionFromOutput(fr_span, _, _) => {
diag.span_label(fr_span, "inferred to be a `FnMut` closure");
- },
- _ => {},
+ }
+ _ => {}
}
- diag.note("`FnMut` closures only have access to their captured variables while they are \
- executing...");
+ diag.note(
+ "`FnMut` closures only have access to their captured variables while they are \
+ executing...",
+ );
diag.note("...therefore, they cannot allow references to captured variables to escape");
diag.buffer(errors_buffer);
DefiningTy::Closure(..) => "closure",
DefiningTy::Generator(..) => "generator",
DefiningTy::FnDef(..) => "function",
- DefiningTy::Const(..) => "const"
+ DefiningTy::Const(..) => "const",
};
// Revert to the normal error in these cases.
|| (category == ConstraintCategory::Assignment && escapes_from == "function")
|| escapes_from == "const"
{
- return self.report_general_error(mir, infcx, mir_def_id,
- fr, true, outlived_fr, false,
- category, span, errors_buffer);
+ return self.report_general_error(
+ mir,
+ infcx,
+ mir_def_id,
+ fr,
+ true,
+ outlived_fr,
+ false,
+ category,
+ span,
+ errors_buffer,
+ );
}
- let mut diag = infcx.tcx.borrowed_data_escapes_closure(span, escapes_from, Origin::Mir);
+ let mut diag = infcx
+ .tcx
+ .borrowed_data_escapes_closure(span, escapes_from, Origin::Mir);
if let Some((Some(outlived_fr_name), outlived_fr_span)) = outlived_fr_name_and_span {
diag.span_label(
),
);
- diag.span_label(span, format!("`{}` escapes the {} body here", fr_name, escapes_from));
+ diag.span_label(
+ span,
+ format!("`{}` escapes the {} body here", fr_name, escapes_from),
+ );
}
diag.buffer(errors_buffer);
let counter = &mut 1;
let fr_name = self.give_region_a_name(infcx, mir, mir_def_id, fr, counter);
fr_name.highlight_region_name(&mut diag);
- let outlived_fr_name = self.give_region_a_name(
- infcx, mir, mir_def_id, outlived_fr, counter);
+ let outlived_fr_name =
+ self.give_region_a_name(infcx, mir, mir_def_id, outlived_fr, counter);
outlived_fr_name.highlight_region_name(&mut diag);
- let mir_def_name = if infcx.tcx.is_closure(mir_def_id) { "closure" } else { "function" };
+ let mir_def_name = if infcx.tcx.is_closure(mir_def_id) {
+ "closure"
+ } else {
+ "function"
+ };
match (category, outlived_fr_is_local, fr_is_local) {
(ConstraintCategory::Return, true, _) => {
- diag.span_label(span, format!(
- "{} was supposed to return data with lifetime `{}` but it is returning \
- data with lifetime `{}`",
- mir_def_name, outlived_fr_name, fr_name
- ));
- },
+ diag.span_label(
+ span,
+ format!(
+ "{} was supposed to return data with lifetime `{}` but it is returning \
+ data with lifetime `{}`",
+ mir_def_name, outlived_fr_name, fr_name
+ ),
+ );
+ }
_ => {
- diag.span_label(span, format!(
- "{}requires that `{}` must outlive `{}`",
- category.description(), fr_name, outlived_fr_name,
- ));
- },
+ diag.span_label(
+ span,
+ format!(
+ "{}requires that `{}` must outlive `{}`",
+ category.description(),
+ fr_name,
+ outlived_fr_name,
+ ),
+ );
+ }
}
- self.add_static_impl_trait_suggestion(
- infcx, &mut diag, fr, fr_name, outlived_fr,
- );
+ self.add_static_impl_trait_suggestion(infcx, &mut diag, fr, fr_name, outlived_fr);
diag.buffer(errors_buffer);
}
fr_name: RegionName,
outlived_fr: RegionVid,
) {
- if let (
- Some(f),
- Some(ty::RegionKind::ReStatic)
- ) = (self.to_error_region(fr), self.to_error_region(outlived_fr)) {
+ if let (Some(f), Some(ty::RegionKind::ReStatic)) =
+ (self.to_error_region(fr), self.to_error_region(outlived_fr))
+ {
if let Some(ty::TyS {
sty: ty::TyKind::Opaque(did, substs),
..
- }) = infcx.tcx.is_suitable_region(f)
- .map(|r| r.def_id)
- .map(|id| infcx.tcx.return_type_impl_trait(id))
- .unwrap_or(None)
+ }) = infcx
+ .tcx
+ .is_suitable_region(f)
+ .map(|r| r.def_id)
+ .map(|id| infcx.tcx.return_type_impl_trait(id))
+ .unwrap_or(None)
{
// Check whether or not the impl trait return type is intended to capture
// data with the static lifetime.
let mut found = false;
for predicate in bounds.predicates {
if let ty::Predicate::TypeOutlives(binder) = predicate {
- if let ty::OutlivesPredicate(
- _,
- ty::RegionKind::ReStatic
- ) = binder.skip_binder() {
+ if let ty::OutlivesPredicate(_, ty::RegionKind::ReStatic) =
+ binder.skip_binder()
+ {
found = true;
break;
}
found
};
- debug!("add_static_impl_trait_suggestion: has_static_predicate={:?}",
- has_static_predicate);
+ debug!(
+ "add_static_impl_trait_suggestion: has_static_predicate={:?}",
+ has_static_predicate
+ );
let static_str = keywords::StaticLifetime.name();
// If there is a static predicate, then the only sensible suggestion is to replace
// fr with `'static`.
if has_static_predicate {
- diag.help(
- &format!(
- "consider replacing `{}` with `{}`",
- fr_name, static_str,
- ),
- );
+ diag.help(&format!(
+ "consider replacing `{}` with `{}`",
+ fr_name, static_str,
+ ));
} else {
// Otherwise, we should suggest adding a constraint on the return type.
let span = infcx.tcx.def_span(*did);
borrow_region: RegionVid,
outlived_region: RegionVid,
) -> (ConstraintCategory, bool, Span, RegionName) {
- let (category, from_closure, span) = self.best_blame_constraint(
- mir,
- borrow_region,
- |r| r == outlived_region
- );
- let outlived_fr_name = self.give_region_a_name(
- infcx, mir, mir_def_id, outlived_region, &mut 1);
+ let (category, from_closure, span) =
+ self.best_blame_constraint(mir, borrow_region, |r| r == outlived_region);
+ let outlived_fr_name =
+ self.give_region_a_name(infcx, mir, mir_def_id, outlived_region, &mut 1);
(category, from_closure, span, outlived_fr_name)
}
crate fn find_sub_region_live_at(&self, fr1: RegionVid, elem: Location) -> RegionVid {
debug!("find_sub_region_live_at(fr1={:?}, elem={:?})", fr1, elem);
// Find all paths
- let (_path, r) =
- self.find_constraint_paths_between_regions(fr1, |r| {
- self.liveness_constraints.contains(r, elem)
- }).unwrap();
+ let (_path, r) = self.find_constraint_paths_between_regions(fr1, |r| {
+ self.liveness_constraints.contains(r, elem)
+ }).unwrap();
r
}
fn retrieve_closure_constraint_info(
&self,
mir: &Mir<'tcx>,
- constraint: &OutlivesConstraint
+ constraint: &OutlivesConstraint,
) -> (ConstraintCategory, bool, Span) {
let loc = match constraint.locations {
Locations::All(span) => return (constraint.category, false, span),
Locations::Single(loc) => loc,
};
- let opt_span_category = self
- .closure_bounds_mapping[&loc]
- .get(&(constraint.sup, constraint.sub));
+ let opt_span_category =
+ self.closure_bounds_mapping[&loc].get(&(constraint.sup, constraint.sub));
opt_span_category
.map(|&(category, span)| (category, true, span))
.unwrap_or((constraint.category, false, mir.source_info(loc).span))
}
/// Returns `true` if a closure is inferred to be an `FnMut` closure.
- crate fn is_closure_fn_mut(
- &self,
- infcx: &InferCtxt<'_, '_, 'tcx>,
- fr: RegionVid,
- ) -> bool {
+ crate fn is_closure_fn_mut(&self, infcx: &InferCtxt<'_, '_, 'tcx>, fr: RegionVid) -> bool {
if let Some(ty::ReFree(free_region)) = self.to_error_region(fr) {
if let ty::BoundRegion::BrEnv = free_region.bound_region {
if let DefiningTy::Closure(def_id, substs) = self.universal_regions.defining_ty {
projects / rust.git / commitdiff