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collect region contexts during mir renumbering

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b-naber 2022-11-08 16:27:01 +01:00 • committed by b-naber
parent cb35a7b481
commit 2f79f73821
9 changed files with 364 additions and 42 deletions
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90
compiler/rustc_borrowck/src/lib.rs
View file

@ -25,7 +25,9 @@ use rustc_hir as hir;
use rustc_hir::def_id::LocalDefId;
use rustc_index::bit_set::ChunkedBitSet;
use rustc_index::vec::IndexVec;
use rustc_infer::infer::{DefiningAnchor, InferCtxt, NllRegionVariableOrigin, TyCtxtInferExt};
use rustc_infer::infer::{
DefiningAnchor, InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin, TyCtxtInferExt,
};
use rustc_middle::mir::{
traversal, Body, ClearCrossCrate, Local, Location, Mutability, NonDivergingIntrinsic, Operand,
Place, PlaceElem, PlaceRef, VarDebugInfoContents,
@ -95,6 +97,7 @@ use nll::{PoloniusOutput, ToRegionVid};
use place_ext::PlaceExt;
use places_conflict::{places_conflict, PlaceConflictBias};
use region_infer::RegionInferenceContext;
use renumber::RegionCtxt;
// FIXME(eddyb) perhaps move this somewhere more centrally.
#[derive(Debug)]
@ -168,10 +171,10 @@ fn do_mir_borrowck<'tcx>(
return_body_with_facts: bool,
) -> (BorrowCheckResult<'tcx>, Option<Box<BodyWithBorrowckFacts<'tcx>>>) {
let def = input_body.source.with_opt_param().as_local().unwrap();
debug!(?def);
let tcx = infcx.tcx;
let infcx = BorrowckInferCtxt::new(infcx);
let param_env = tcx.param_env(def.did);
let mut local_names = IndexVec::from_elem(None, &input_body.local_decls);
@ -219,7 +222,7 @@ fn do_mir_borrowck<'tcx>(
let mut body_owned = input_body.clone();
let mut promoted = input_promoted.clone();
let free_regions =
nll::replace_regions_in_mir(infcx, param_env, &mut body_owned, &mut promoted);
nll::replace_regions_in_mir(&infcx, param_env, &mut body_owned, &mut promoted);
let body = &body_owned; // no further changes
let location_table_owned = LocationTable::new(body);
@ -257,7 +260,7 @@ fn do_mir_borrowck<'tcx>(
opt_closure_req,
nll_errors,
} = nll::compute_regions(
infcx,
&infcx,
free_regions,
body,
&promoted,
@ -272,12 +275,12 @@ fn do_mir_borrowck<'tcx>(
// Dump MIR results into a file, if that is enabled. This let us
// write unit-tests, as well as helping with debugging.
nll::dump_mir_results(infcx, &body, &regioncx, &opt_closure_req);
nll::dump_mir_results(&infcx, &body, &regioncx, &opt_closure_req);
// We also have a `#[rustc_regions]` annotation that causes us to dump
// information.
nll::dump_annotation(
infcx,
&infcx,
&body,
&regioncx,
&opt_closure_req,
@ -321,7 +324,7 @@ fn do_mir_borrowck<'tcx>(
if let Err((move_data, move_errors)) = move_data_results {
let mut promoted_mbcx = MirBorrowckCtxt {
infcx,
infcx: &infcx,
param_env,
body: promoted_body,
move_data: &move_data,
@ -350,7 +353,7 @@ fn do_mir_borrowck<'tcx>(
}
let mut mbcx = MirBorrowckCtxt {
infcx,
infcx: &infcx,
param_env,
body,
move_data: &mdpe.move_data,
@ -482,22 +485,81 @@ pub struct BodyWithBorrowckFacts<'tcx> {
pub location_table: LocationTable,
}
struct BorrowckInferCtxt<'cx, 'tcx> {
pub struct BorrowckInferCtxt<'cx, 'tcx> {
pub(crate) infcx: &'cx InferCtxt<'tcx>,
#[cfg(debug_assertions)]
pub(crate) _reg_var_to_origin: RefCell<FxHashMap<ty::Region<'tcx>, NllRegionVariableOrigin>>,
pub(crate) reg_var_to_origin: RefCell<FxHashMap<ty::RegionVid, RegionCtxt>>,
}
impl<'cx, 'tcx> BorrowckInferCtxt<'cx, 'tcx> {
#[cfg(not(debug_assertions))]
pub(crate) fn _new(infcx: &'cx InferCtxt<'tcx>) -> Self {
pub(crate) fn new(infcx: &'cx InferCtxt<'tcx>) -> Self {
BorrowckInferCtxt { infcx }
}
#[cfg(debug_assertions)]
pub(crate) fn _new(infcx: &'cx InferCtxt<'tcx>) -> Self {
BorrowckInferCtxt { infcx, _reg_var_to_origin: RefCell::new(Default::default()) }
pub(crate) fn new(infcx: &'cx InferCtxt<'tcx>) -> Self {
BorrowckInferCtxt { infcx, reg_var_to_origin: RefCell::new(Default::default()) }
}
#[cfg(not(debug_assertions))]
pub(crate) fn next_region_var(&self, origin: RegionVariableOrigin) -> ty::Region<'tcx> {
self.infcx.next_region_var(origin)
}
#[cfg(debug_assertions)]
pub(crate) fn next_region_var(
&self,
origin: RegionVariableOrigin,
ctxt: RegionCtxt,
) -> ty::Region<'tcx> {
let next_region = self.infcx.next_region_var(origin);
let vid = next_region
.try_get_var()
.unwrap_or_else(|| bug!("expected RegionKind::RegionVar on {:?}", next_region));
debug!("inserting vid {:?} with origin {:?} into var_to_origin", vid, origin);
let mut var_to_origin = self.reg_var_to_origin.borrow_mut();
let prev = var_to_origin.insert(vid, ctxt);
debug!("var_to_origin after insertion: {:?}", var_to_origin);
// This only makes sense if not called in a canonicalization context. If this
// ever changes we either want to get rid of `BorrowckInferContext::reg_var_to_origin`
// or modify how we track nll region vars for that map.
assert!(matches!(prev, None));
next_region
}
#[cfg(not(debug_assertions))]
pub(crate) fn next_nll_region_var(&self, origin: NllRegionVariableOrigin) -> ty::Region<'tcx> {
self.infcx.next_nll_region_var(origin)
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
pub(crate) fn next_nll_region_var(
&self,
origin: NllRegionVariableOrigin,
ctxt: RegionCtxt,
) -> ty::Region<'tcx> {
let next_region = self.infcx.next_nll_region_var(origin.clone());
let vid = next_region
.try_get_var()
.unwrap_or_else(|| bug!("expected RegionKind::RegionVar on {:?}", next_region));
debug!("inserting vid {:?} with origin {:?} into var_to_origin", vid, origin);
let mut var_to_origin = self.reg_var_to_origin.borrow_mut();
let prev = var_to_origin.insert(vid, ctxt);
debug!("var_to_origin after insertion: {:?}", var_to_origin);
// This only makes sense if not called in a canonicalization context. If this
// ever changes we either want to get rid of `BorrowckInferContext::reg_var_to_origin`
// or modify how we track nll region vars for that map.
assert!(matches!(prev, None));
next_region
}
}
@ -510,7 +572,7 @@ impl<'cx, 'tcx> Deref for BorrowckInferCtxt<'cx, 'tcx> {
}
struct MirBorrowckCtxt<'cx, 'tcx> {
infcx: &'cx InferCtxt<'tcx>,
infcx: &'cx BorrowckInferCtxt<'cx, 'tcx>,
param_env: ParamEnv<'tcx>,
body: &'cx Body<'tcx>,
move_data: &'cx MoveData<'tcx>,

16
compiler/rustc_borrowck/src/nll.rs
View file

@ -5,7 +5,6 @@
use rustc_data_structures::vec_map::VecMap;
use rustc_hir::def_id::LocalDefId;
use rustc_index::vec::IndexVec;
use rustc_infer::infer::InferCtxt;
use rustc_middle::mir::{create_dump_file, dump_enabled, dump_mir, PassWhere};
use rustc_middle::mir::{
BasicBlock, Body, ClosureOutlivesSubject, ClosureRegionRequirements, LocalKind, Location,
@ -37,7 +36,7 @@ use crate::{
renumber,
type_check::{self, MirTypeckRegionConstraints, MirTypeckResults},
universal_regions::UniversalRegions,
Upvar,
BorrowckInferCtxt, Upvar,
};
pub type PoloniusOutput = Output<RustcFacts>;
@ -58,7 +57,7 @@ pub(crate) struct NllOutput<'tcx> {
/// `compute_regions`.
#[instrument(skip(infcx, param_env, body, promoted), level = "debug")]
pub(crate) fn replace_regions_in_mir<'tcx>(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
param_env: ty::ParamEnv<'tcx>,
body: &mut Body<'tcx>,
promoted: &mut IndexVec<Promoted, Body<'tcx>>,
@ -157,7 +156,7 @@ fn populate_polonius_move_facts(
///
/// This may result in errors being reported.
pub(crate) fn compute_regions<'cx, 'tcx>(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
universal_regions: UniversalRegions<'tcx>,
body: &Body<'tcx>,
promoted: &IndexVec<Promoted, Body<'tcx>>,
@ -258,6 +257,11 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
borrow_set,
);
if cfg!(debug_assertions) {
let var_to_origin = infcx.reg_var_to_origin.borrow();
debug!("var_to_origin: {:#?}", var_to_origin);
}
let mut regioncx = RegionInferenceContext::new(
var_origins,
universal_regions,
@ -322,7 +326,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
}
pub(super) fn dump_mir_results<'tcx>(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
body: &Body<'tcx>,
regioncx: &RegionInferenceContext<'tcx>,
closure_region_requirements: &Option<ClosureRegionRequirements<'_>>,
@ -372,7 +376,7 @@ pub(super) fn dump_mir_results<'tcx>(
#[allow(rustc::diagnostic_outside_of_impl)]
#[allow(rustc::untranslatable_diagnostic)]
pub(super) fn dump_annotation<'tcx>(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
body: &Body<'tcx>,
regioncx: &RegionInferenceContext<'tcx>,
closure_region_requirements: &Option<ClosureRegionRequirements<'_>>,

115
compiler/rustc_borrowck/src/renumber.rs
View file

@ -1,18 +1,23 @@
<<<<<<< HEAD
#![deny(rustc::untranslatable_diagnostic)]
#![deny(rustc::diagnostic_outside_of_impl)]
=======
use crate::BorrowckInferCtxt;
>>>>>>> 2464f768a17 (collect region contexts during mir renumbering)
use rustc_index::vec::IndexVec;
use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_middle::mir::visit::{MutVisitor, TyContext};
use rustc_middle::mir::Constant;
use rustc_middle::mir::{Body, Location, Promoted};
use rustc_middle::ty::subst::SubstsRef;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_span::Symbol;
/// Replaces all free regions appearing in the MIR with fresh
/// inference variables, returning the number of variables created.
#[instrument(skip(infcx, body, promoted), level = "debug")]
pub fn renumber_mir<'tcx>(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
body: &mut Body<'tcx>,
promoted: &mut IndexVec<Promoted, Body<'tcx>>,
) {
@ -29,8 +34,9 @@ pub fn renumber_mir<'tcx>(
/// Replaces all regions appearing in `value` with fresh inference
/// variables.
#[cfg(not(debug_assertions))]
#[instrument(skip(infcx), level = "debug")]
pub fn renumber_regions<'tcx, T>(infcx: &InferCtxt<'tcx>, value: T) -> T
pub(crate) fn renumber_regions<'tcx, T>(infcx: &BorrowckInferCtxt<'_, 'tcx>, value: T) -> T
where
T: TypeFoldable<'tcx>,
{
@ -40,11 +46,73 @@ where
})
}
/// Replaces all regions appearing in `value` with fresh inference
/// variables.
#[cfg(debug_assertions)]
#[instrument(skip(infcx), level = "debug")]
pub(crate) fn renumber_regions<'tcx, T>(
infcx: &BorrowckInferCtxt<'_, 'tcx>,
value: T,
ctxt: RegionCtxt,
) -> T
where
T: TypeFoldable<'tcx>,
{
infcx.tcx.fold_regions(value, |_region, _depth| {
let origin = NllRegionVariableOrigin::Existential { from_forall: false };
infcx.next_nll_region_var(origin, ctxt)
})
}
#[cfg(debug_assertions)]
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub(crate) enum RegionCtxt {
Location(Location),
TyContext(TyContext),
Free(Symbol),
Bound(Symbol),
LateBound(Symbol),
Existential(Option<Symbol>),
Placeholder(Symbol),
Unknown,
}
#[cfg(debug_assertions)]
impl RegionCtxt {
/// Used to determine the representative of a component in the strongly connected
/// constraint graph
/// FIXME: don't use underscore here. Got a 'not used' error for some reason
pub(crate) fn _preference_value(self) -> usize {
let _anon = Symbol::intern("anon");
match self {
RegionCtxt::Unknown => 1,
RegionCtxt::Existential(None) => 2,
RegionCtxt::Existential(Some(_anon))
| RegionCtxt::Free(_anon)
| RegionCtxt::Bound(_anon)
| RegionCtxt::LateBound(_anon) => 2,
RegionCtxt::Location(_) => 3,
RegionCtxt::TyContext(_) => 4,
_ => 5,
}
}
}
struct NllVisitor<'a, 'tcx> {
infcx: &'a InferCtxt<'tcx>,
infcx: &'a BorrowckInferCtxt<'a, 'tcx>,
}
impl<'a, 'tcx> NllVisitor<'a, 'tcx> {
#[cfg(debug_assertions)]
fn renumber_regions<T>(&mut self, value: T, ctxt: RegionCtxt) -> T
where
T: TypeFoldable<'tcx>,
{
renumber_regions(self.infcx, value, ctxt)
}
#[cfg(not(debug_assertions))]
fn renumber_regions<T>(&mut self, value: T) -> T
where
T: TypeFoldable<'tcx>,
@ -58,13 +126,23 @@ impl<'a, 'tcx> MutVisitor<'tcx> for NllVisitor<'a, 'tcx> {
self.infcx.tcx
}
#[cfg(not(debug_assertions))]
#[instrument(skip(self), level = "debug")]
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, ty_context: TyContext) {
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _ty_context: TyContext) {
*ty = self.renumber_regions(*ty);
debug!(?ty);
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _ty_context: TyContext) {
*ty = self.renumber_regions(*ty, RegionCtxt::TyContext(_ty_context));
debug!(?ty);
}
#[cfg(not(debug_assertions))]
#[instrument(skip(self), level = "debug")]
fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
*substs = self.renumber_regions(*substs);
@ -72,6 +150,15 @@ impl<'a, 'tcx> MutVisitor<'tcx> for NllVisitor<'a, 'tcx> {
debug!(?substs);
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
*substs = self.renumber_regions(*substs, RegionCtxt::Location(location));
debug!(?substs);
}
#[cfg(not(debug_assertions))]
#[instrument(skip(self), level = "debug")]
fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
let old_region = *region;
@ -80,10 +167,28 @@ impl<'a, 'tcx> MutVisitor<'tcx> for NllVisitor<'a, 'tcx> {
debug!(?region);
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
let old_region = *region;
*region = self.renumber_regions(old_region, RegionCtxt::Location(location));
debug!(?region);
}
#[cfg(not(debug_assertions))]
#[instrument(skip(self), level = "debug")]
fn visit_constant(&mut self, constant: &mut Constant<'tcx>, _location: Location) {
let literal = constant.literal;
constant.literal = self.renumber_regions(literal);
debug!("constant: {:#?}", constant);
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
fn visit_constant(&mut self, constant: &mut Constant<'tcx>, _location: Location) {
let literal = constant.literal;
constant.literal = self.renumber_regions(literal, RegionCtxt::Location(_location));
debug!("constant: {:#?}", constant);
}
}

34
compiler/rustc_borrowck/src/type_check/mod.rs
View file

@ -1335,11 +1335,35 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
};
let (sig, map) = tcx.replace_late_bound_regions(sig, |br| {
self.infcx.next_region_var(LateBoundRegion(
term.source_info.span,
br.kind,
LateBoundRegionConversionTime::FnCall,
))
#[cfg(not(debug_assertions))]
{
self.infcx.next_region_var(LateBoundRegion(
term.source_info.span,
br.kind,
LateBoundRegionConversionTime::FnCall,
))
}
#[cfg(debug_assertions)]
{
use crate::renumber::RegionCtxt;
use rustc_span::Symbol;
let name = match br.kind {
ty::BoundRegionKind::BrAnon(_) => Symbol::intern("anon"),
ty::BoundRegionKind::BrNamed(_, name) => name,
ty::BoundRegionKind::BrEnv => Symbol::intern("env"),
};
self.infcx.next_region_var(
LateBoundRegion(
term.source_info.span,
br.kind,
LateBoundRegionConversionTime::FnCall,
),
RegionCtxt::LateBound(name),
)
}
});
debug!(?sig);
// IMPORTANT: We have to prove well formed for the function signature before

117
compiler/rustc_borrowck/src/universal_regions.rs
View file

@ -20,15 +20,18 @@ use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::lang_items::LangItem;
use rustc_hir::{BodyOwnerKind, HirId};
use rustc_index::vec::{Idx, IndexVec};
use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::{
self, DefIdTree, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt,
};
use rustc_middle::ty::{InternalSubsts, SubstsRef};
use rustc_span::Symbol;
use std::iter;
use crate::nll::ToRegionVid;
use crate::renumber::RegionCtxt;
use crate::BorrowckInferCtxt;
#[derive(Debug)]
pub struct UniversalRegions<'tcx> {
@ -224,7 +227,7 @@ impl<'tcx> UniversalRegions<'tcx> {
/// signature. This will also compute the relationships that are
/// known between those regions.
pub fn new(
infcx: &InferCtxt<'tcx>,
infcx: &BorrowckInferCtxt<'_, 'tcx>,
mir_def: ty::WithOptConstParam<LocalDefId>,
param_env: ty::ParamEnv<'tcx>,
) -> Self {
@ -385,7 +388,7 @@ impl<'tcx> UniversalRegions<'tcx> {
}
struct UniversalRegionsBuilder<'cx, 'tcx> {
infcx: &'cx InferCtxt<'tcx>,
infcx: &'cx BorrowckInferCtxt<'cx, 'tcx>,
mir_def: ty::WithOptConstParam<LocalDefId>,
mir_hir_id: HirId,
param_env: ty::ParamEnv<'tcx>,
@ -403,7 +406,13 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
assert_eq!(FIRST_GLOBAL_INDEX, self.infcx.num_region_vars());
// Create the "global" region that is always free in all contexts: 'static.
#[cfg(not(debug_assertions))]
let fr_static = self.infcx.next_nll_region_var(FR).to_region_vid();
#[cfg(debug_assertions)]
let fr_static = self
.infcx
.next_nll_region_var(FR, RegionCtxt::Free(Symbol::intern("static")))
.to_region_vid();
// We've now added all the global regions. The next ones we
// add will be external.
@ -480,6 +489,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
LangItem::VaList,
Some(self.infcx.tcx.def_span(self.mir_def.did)),
);
let reg_vid = self.infcx.next_nll_region_var(FR, RegionCtxt::Free(Symbol::intern("c-variadic")).to_region_vid();
let region =
self.infcx.tcx.mk_re_var(self.infcx.next_nll_region_var(FR).to_region_vid());
let va_list_ty =
@ -491,7 +501,14 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
}
}
#[cfg(not(debug_assertions))]
let fr_fn_body = self.infcx.next_nll_region_var(FR).to_region_vid();
#[cfg(debug_assertions)]
let fr_fn_body = self
.infcx
.next_nll_region_var(FR, RegionCtxt::Free(Symbol::intern("fn_body")))
.to_region_vid();
let num_universals = self.infcx.num_region_vars();
debug!("build: global regions = {}..{}", FIRST_GLOBAL_INDEX, first_extern_index);
@ -718,7 +735,8 @@ trait InferCtxtExt<'tcx> {
);
}
impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
impl<'cx, 'tcx> InferCtxtExt<'tcx> for BorrowckInferCtxt<'cx, 'tcx> {
#[cfg(not(debug_assertions))]
fn replace_free_regions_with_nll_infer_vars<T>(
&self,
origin: NllRegionVariableOrigin,
@ -727,9 +745,33 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
where
T: TypeFoldable<'tcx>,
{
self.tcx.fold_regions(value, |_region, _depth| self.next_nll_region_var(origin))
self.tcx.fold_regions(value, |_region, _depth| self.infcx.next_nll_region_var(origin))
}
#[cfg(debug_assertions)]
#[instrument(skip(self), level = "debug")]
fn replace_free_regions_with_nll_infer_vars<T>(
&self,
origin: NllRegionVariableOrigin,
value: T,
) -> T
where
T: TypeFoldable<'tcx>,
{
self.infcx.tcx.fold_regions(value, |region, _depth| {
let name = match region.get_name() {
Some(name) => name,
_ => Symbol::intern("anon"),
};
debug!(?region, ?name);
let reg_var = self.next_nll_region_var(origin, RegionCtxt::Free(name));
reg_var
})
}
#[cfg(not(debug_assertions))]
#[instrument(level = "debug", skip(self, indices))]
fn replace_bound_regions_with_nll_infer_vars<T>(
&self,
@ -752,6 +794,38 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
value
}
#[cfg(debug_assertions)]
#[instrument(level = "debug", skip(self, indices))]
fn replace_bound_regions_with_nll_infer_vars<T>(
&self,
origin: NllRegionVariableOrigin,
all_outlive_scope: LocalDefId,
value: ty::Binder<'tcx, T>,
indices: &mut UniversalRegionIndices<'tcx>,
) -> T
where
T: TypeFoldable<'tcx>,
{
let (value, _map) = self.tcx.replace_late_bound_regions(value, |br| {
debug!(?br);
let liberated_region = self.tcx.mk_region(ty::ReFree(ty::FreeRegion {
scope: all_outlive_scope.to_def_id(),
bound_region: br.kind,
}));
let name = match br.kind.get_name() {
Some(name) => name,
_ => Symbol::intern("anon"),
};
let region_vid = self.next_nll_region_var(origin, RegionCtxt::Bound(name));
indices.insert_late_bound_region(liberated_region, region_vid.to_region_vid());
debug!(?liberated_region, ?region_vid);
region_vid
});
value
}
/// Finds late-bound regions that do not appear in the parameter listing and adds them to the
/// indices vector. Typically, we identify late-bound regions as we process the inputs and
/// outputs of the closure/function. However, sometimes there are late-bound regions which do
@ -761,6 +835,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
/// entries for them and store them in the indices map. This code iterates over the complete
/// set of late-bound regions and checks for any that we have not yet seen, adding them to the
/// inputs vector.
#[cfg(not(debug_assertions))]
#[instrument(skip(self, indices))]
fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope(
&self,
@ -792,6 +867,38 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
}
});
}
/// Finds late-bound regions that do not appear in the parameter listing and adds them to the
/// indices vector. Typically, we identify late-bound regions as we process the inputs and
/// outputs of the closure/function. However, sometimes there are late-bound regions which do
/// not appear in the fn parameters but which are nonetheless in scope. The simplest case of
/// this are unused functions, like fn foo<'a>() { } (see e.g., #51351). Despite not being used,
/// users can still reference these regions (e.g., let x: &'a u32 = &22;), so we need to create
/// entries for them and store them in the indices map. This code iterates over the complete
/// set of late-bound regions and checks for any that we have not yet seen, adding them to the
/// inputs vector.
#[cfg(debug_assertions)]
#[instrument(skip(self, indices))]
fn replace_late_bound_regions_with_nll_infer_vars(
&self,
mir_def_id: LocalDefId,
indices: &mut UniversalRegionIndices<'tcx>,
) {
let typeck_root_def_id = self.tcx.typeck_root_def_id(mir_def_id.to_def_id());
for_each_late_bound_region_defined_on(self.tcx, typeck_root_def_id, |r| {
debug!(?r);
if !indices.indices.contains_key(&r) {
let name = match r.get_name() {
Some(name) => name,
_ => Symbol::intern("anon"),
};
let region_vid = self.next_nll_region_var(FR, RegionCtxt::LateBound(name));
debug!(?region_vid);
indices.insert_late_bound_region(r, region_vid.to_region_vid());
}
});
}
}
impl<'tcx> UniversalRegionIndices<'tcx> {