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uplift fold_regions to rustc_type_ir

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This commit is contained in:
lcnr 2024-11-27 18:37:39 +01:00
parent f005c7437d
commit 9fe7750bcd
24 changed files with 129 additions and 115 deletions
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3
compiler/rustc_borrowck/src/lib.rs
View file

@ -34,6 +34,7 @@ use rustc_infer::infer::{
use rustc_middle::mir::tcx::PlaceTy;
use rustc_middle::mir::*;
use rustc_middle::query::Providers;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, ParamEnv, RegionVid, TyCtxt, TypingMode};
use rustc_middle::{bug, span_bug};
use rustc_mir_dataflow::impls::{
@ -502,7 +503,7 @@ impl<'tcx> BorrowckInferCtxt<'tcx> {
for data in tcx.typeck(def_id).concrete_opaque_types.iter().map(|(k, v)| (*k, *v)) {
// HIR typeck did not infer the regions of the opaque, so we instantiate
// them with fresh inference variables.
let (key, hidden_ty) = tcx.fold_regions(data, |_, _| {
let (key, hidden_ty) = fold_regions(tcx, data, |_, _| {
self.next_nll_region_var_in_universe(
NllRegionVariableOrigin::Existential { from_forall: false },
ty::UniverseIndex::ROOT,

5
compiler/rustc_borrowck/src/region_infer/mod.rs
View file

@ -18,6 +18,7 @@ use rustc_middle::mir::{
TerminatorKind,
};
use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable, UniverseIndex};
use rustc_mir_dataflow::points::DenseLocationMap;
use rustc_span::Span;
@ -1100,7 +1101,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
let ty = ty.fold_with(&mut OpaqueFolder { tcx });
let mut failed = false;
let ty = tcx.fold_regions(ty, |r, _depth| {
let ty = fold_regions(tcx, ty, |r, _depth| {
let r_vid = self.to_region_vid(r);
let r_scc = self.constraint_sccs.scc(r_vid);
@ -1273,7 +1274,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
tcx.fold_regions(value, |r, _db| {
fold_regions(tcx, value, |r, _db| {
let vid = self.to_region_vid(r);
let scc = self.constraint_sccs.scc(vid);
let repr = self.scc_representative(scc);

7
compiler/rustc_borrowck/src/region_infer/opaque_types.rs
View file

@ -3,6 +3,7 @@ use rustc_errors::ErrorGuaranteed;
use rustc_hir::def_id::LocalDefId;
use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin, TyCtxtInferExt as _};
use rustc_macros::extension;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::visit::TypeVisitableExt;
use rustc_middle::ty::{
self, GenericArgKind, GenericArgs, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable,
@ -117,7 +118,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
});
debug!(?opaque_type_key, ?arg_regions);
let concrete_type = infcx.tcx.fold_regions(concrete_type, |region, _| {
let concrete_type = fold_regions(infcx.tcx, concrete_type, |region, _| {
arg_regions
.iter()
.find(|&&(arg_vid, _)| self.eval_equal(region.as_var(), arg_vid))
@ -204,7 +205,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
tcx.fold_regions(ty, |region, _| match *region {
fold_regions(tcx, ty, |region, _| match *region {
ty::ReVar(vid) => {
let scc = self.constraint_sccs.scc(vid);
@ -442,7 +443,7 @@ impl<'tcx> LazyOpaqueTyEnv<'tcx> {
let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
let mut seen = vec![tcx.lifetimes.re_static];
let canonical_args = tcx.fold_regions(args, |r1, _| {
let canonical_args = fold_regions(tcx, args, |r1, _| {
if r1.is_error() {
r1
} else if let Some(&r2) = seen.iter().find(|&&r2| {

3
compiler/rustc_borrowck/src/renumber.rs
View file

@ -2,6 +2,7 @@ use rustc_index::IndexSlice;
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_middle::mir::visit::{MutVisitor, TyContext};
use rustc_middle::mir::{Body, ConstOperand, Location, Promoted};
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt, TypeFoldable};
use rustc_span::Symbol;
use tracing::{debug, instrument};
@ -68,7 +69,7 @@ impl<'a, 'tcx> RegionRenumberer<'a, 'tcx> {
F: Fn() -> RegionCtxt,
{
let origin = NllRegionVariableOrigin::Existential { from_forall: false };
self.infcx.tcx.fold_regions(value, |_region, _depth| {
fold_regions(self.infcx.tcx, value, |_region, _depth| {
self.infcx.next_nll_region_var(origin, || region_ctxt_fn())
})
}

3
compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
View file

@ -8,6 +8,7 @@ use rustc_middle::bug;
use rustc_middle::mir::{ClosureOutlivesSubject, ClosureRegionRequirements, ConstraintCategory};
use rustc_middle::traits::ObligationCause;
use rustc_middle::traits::query::NoSolution;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, GenericArgKind, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
use rustc_span::Span;
use rustc_trait_selection::traits::ScrubbedTraitError;
@ -216,7 +217,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
/// are dealt with during trait solving.
fn replace_placeholders_with_nll<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, value: T) -> T {
if value.has_placeholders() {
self.tcx.fold_regions(value, |r, _| match *r {
fold_regions(self.tcx, value, |r, _| match *r {
ty::RePlaceholder(placeholder) => {
self.constraints.placeholder_region(self.infcx, placeholder)
}

5
compiler/rustc_borrowck/src/type_check/mod.rs
View file

@ -26,6 +26,7 @@ use rustc_middle::mir::*;
use rustc_middle::traits::query::NoSolution;
use rustc_middle::ty::adjustment::PointerCoercion;
use rustc_middle::ty::cast::CastTy;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::visit::TypeVisitableExt;
use rustc_middle::ty::{
self, Binder, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, CoroutineArgsExt,
@ -213,7 +214,7 @@ pub(crate) fn type_check<'a, 'tcx>(
// Convert all regions to nll vars.
let (opaque_type_key, hidden_type) =
infcx.tcx.fold_regions((opaque_type_key, hidden_type), |region, _| {
fold_regions(infcx.tcx, (opaque_type_key, hidden_type), |region, _| {
match region.kind() {
ty::ReVar(_) => region,
ty::RePlaceholder(placeholder) => {
@ -2073,7 +2074,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
);
let is_implicit_coercion = coercion_source == CoercionSource::Implicit;
let unsize_to = tcx.fold_regions(ty, |r, _| {
let unsize_to = fold_regions(tcx, ty, |r, _| {
if let ty::ReVar(_) = r.kind() { tcx.lifetimes.re_erased } else { r }
});
self.prove_trait_ref(

6
compiler/rustc_borrowck/src/universal_regions.rs
View file

@ -26,7 +26,7 @@ use rustc_hir::lang_items::LangItem;
use rustc_index::IndexVec;
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_macros::extension;
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::fold::{TypeFoldable, fold_regions};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::{
self, GenericArgs, GenericArgsRef, InlineConstArgs, InlineConstArgsParts, RegionVid, Ty,
@ -824,7 +824,7 @@ impl<'tcx> BorrowckInferCtxt<'tcx> {
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
self.infcx.tcx.fold_regions(value, |region, _depth| {
fold_regions(self.infcx.tcx, value, |region, _depth| {
let name = region.get_name_or_anon();
debug!(?region, ?name);
@ -906,7 +906,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
tcx.fold_regions(value, |region, _| ty::Region::new_var(tcx, self.to_region_vid(region)))
fold_regions(tcx, value, |region, _| ty::Region::new_var(tcx, self.to_region_vid(region)))
}
}

4
compiler/rustc_hir_analysis/src/check/check.rs
View file

@ -17,7 +17,7 @@ use rustc_middle::middle::resolve_bound_vars::ResolvedArg;
use rustc_middle::middle::stability::EvalResult;
use rustc_middle::span_bug;
use rustc_middle::ty::error::TypeErrorToStringExt;
use rustc_middle::ty::fold::BottomUpFolder;
use rustc_middle::ty::fold::{BottomUpFolder, fold_regions};
use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
use rustc_middle::ty::util::{Discr, InspectCoroutineFields, IntTypeExt};
use rustc_middle::ty::{
@ -346,7 +346,7 @@ fn check_opaque_meets_bounds<'tcx>(
// FIXME: Consider wrapping the hidden type in an existential `Binder` and instantiating it
// here rather than using ReErased.
let hidden_ty = tcx.type_of(def_id.to_def_id()).instantiate(tcx, args);
let hidden_ty = tcx.fold_regions(hidden_ty, |re, _dbi| match re.kind() {
let hidden_ty = fold_regions(tcx, hidden_ty, |re, _dbi| match re.kind() {
ty::ReErased => infcx.next_region_var(RegionVariableOrigin::MiscVariable(span)),
_ => re,
});

3
compiler/rustc_hir_analysis/src/collect.rs
View file

@ -34,6 +34,7 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
use rustc_infer::traits::ObligationCause;
use rustc_middle::hir::nested_filter;
use rustc_middle::query::Providers;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::util::{Discr, IntTypeExt};
use rustc_middle::ty::{self, AdtKind, Const, IsSuggestable, Ty, TyCtxt, TypingMode};
use rustc_middle::{bug, span_bug};
@ -1415,7 +1416,7 @@ fn infer_return_ty_for_fn_sig<'tcx>(
GenericParamKind::Lifetime { .. } => true,
_ => false,
});
let fn_sig = tcx.fold_regions(fn_sig, |r, _| match *r {
let fn_sig = fold_regions(tcx, fn_sig, |r, _| match *r {
ty::ReErased => {
if has_region_params {
ty::Region::new_error_with_message(

3
compiler/rustc_hir_analysis/src/collect/type_of.rs
View file

@ -5,6 +5,7 @@ use rustc_hir as hir;
use rustc_hir::HirId;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_middle::query::plumbing::CyclePlaceholder;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::print::with_forced_trimmed_paths;
use rustc_middle::ty::util::IntTypeExt;
use rustc_middle::ty::{self, Article, IsSuggestable, Ty, TyCtxt, TypeVisitableExt};
@ -113,7 +114,7 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
// so no need for ConstArg.
Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), span, .. }) if e.hir_id == hir_id => {
let ty = tcx.typeck(def_id).node_type(tcx.local_def_id_to_hir_id(def_id));
let ty = tcx.fold_regions(ty, |r, _| {
let ty = fold_regions(tcx, ty, |r, _| {
if r.is_erased() { ty::Region::new_error_misc(tcx) } else { r }
});
let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false, None) {

3
compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
View file

@ -37,6 +37,7 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
use rustc_infer::traits::ObligationCause;
use rustc_middle::middle::stability::AllowUnstable;
use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::print::PrintPolyTraitRefExt as _;
use rustc_middle::ty::{
self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, ParamEnv, Ty, TyCtxt,
@ -1569,7 +1570,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
infcx.fresh_args_for_item(DUMMY_SP, impl_def_id),
);
let value = tcx.fold_regions(qself_ty, |_, _| tcx.lifetimes.re_erased);
let value = fold_regions(tcx, qself_ty, |_, _| tcx.lifetimes.re_erased);
// FIXME: Don't bother dealing with non-lifetime binders here...
if value.has_escaping_bound_vars() {
return false;

3
compiler/rustc_hir_analysis/src/hir_wf_check.rs
View file

@ -5,6 +5,7 @@ use rustc_infer::infer::TyCtxtInferExt;
use rustc_infer::traits::{ObligationCause, WellFormedLoc};
use rustc_middle::bug;
use rustc_middle::query::Providers;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, TyCtxt, TypingMode};
use rustc_span::def_id::LocalDefId;
use rustc_trait_selection::traits::{self, ObligationCtxt};
@ -75,7 +76,7 @@ fn diagnostic_hir_wf_check<'tcx>(
// This visitor can walk into binders, resulting in the `tcx_ty` to
// potentially reference escaping bound variables. We simply erase
// those here.
let tcx_ty = self.tcx.fold_regions(tcx_ty, |r, _| {
let tcx_ty = fold_regions(self.tcx, tcx_ty, |r, _| {
if r.is_bound() { self.tcx.lifetimes.re_erased } else { r }
});
let cause = traits::ObligationCause::new(

7
compiler/rustc_hir_typeck/src/writeback.rs
View file

@ -12,7 +12,7 @@ use rustc_hir::intravisit::{self, Visitor};
use rustc_middle::span_bug;
use rustc_middle::traits::ObligationCause;
use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCoercion};
use rustc_middle::ty::fold::{TypeFoldable, TypeFolder};
use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, fold_regions};
use rustc_middle::ty::visit::TypeVisitableExt;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperFoldable};
use rustc_span::Span;
@ -827,7 +827,10 @@ impl<'cx, 'tcx> Resolver<'cx, 'tcx> {
// no reason to keep regions around. They will be repopulated during MIR
// borrowck, and specifically region constraints will be populated during
// MIR typeck which is run on the new body.
value = tcx.fold_regions(value, |_, _| tcx.lifetimes.re_erased);
//
// We're not using `tcx.erase_regions` as that also anonymizes bound variables,
// regressing borrowck diagnostics.
value = fold_regions(tcx, value, |_, _| tcx.lifetimes.re_erased);
// Normalize consts in writeback, because GCE doesn't normalize eagerly.
if tcx.features().generic_const_exprs() {

4
compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
View file

@ -9,7 +9,7 @@ use rustc_data_structures::graph::implementation::{
use rustc_data_structures::intern::Interned;
use rustc_data_structures::unord::UnordSet;
use rustc_index::{IndexSlice, IndexVec};
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::fold::{TypeFoldable, fold_regions};
use rustc_middle::ty::{
self, ReBound, ReEarlyParam, ReErased, ReError, ReLateParam, RePlaceholder, ReStatic, ReVar,
Region, RegionVid, Ty, TyCtxt,
@ -974,7 +974,7 @@ impl<'tcx> LexicalRegionResolutions<'tcx> {
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
tcx.fold_regions(value, |r, _db| self.resolve_region(tcx, r))
fold_regions(tcx, value, |r, _db| self.resolve_region(tcx, r))
}
fn value(&self, rid: RegionVid) -> &VarValue<'tcx> {

4
compiler/rustc_infer/src/infer/mod.rs
View file

@ -33,7 +33,7 @@ use rustc_middle::traits::select;
pub use rustc_middle::ty::IntVarValue;
use rustc_middle::ty::error::{ExpectedFound, TypeError};
use rustc_middle::ty::fold::{
BoundVarReplacerDelegate, TypeFoldable, TypeFolder, TypeSuperFoldable,
BoundVarReplacerDelegate, TypeFoldable, TypeFolder, TypeSuperFoldable, fold_regions,
};
use rustc_middle::ty::visit::TypeVisitableExt;
use rustc_middle::ty::{
@ -1165,7 +1165,7 @@ impl<'tcx> InferCtxt<'tcx> {
}
if value.has_infer_regions() {
let guar = self.dcx().delayed_bug(format!("`{value:?}` is not fully resolved"));
Ok(self.tcx.fold_regions(value, |re, _| {
Ok(fold_regions(self.tcx, value, |re, _| {
if re.is_var() { ty::Region::new_error(self.tcx, guar) } else { re }
}))
} else {

5
compiler/rustc_middle/src/mir/query.rs
View file

@ -17,6 +17,7 @@ use smallvec::SmallVec;
use super::{ConstValue, SourceInfo};
use crate::mir;
use crate::ty::fold::fold_regions;
use crate::ty::{self, CoroutineArgsExt, OpaqueHiddenType, Ty, TyCtxt};
rustc_index::newtype_index! {
@ -315,7 +316,7 @@ impl<'tcx> ClosureOutlivesSubjectTy<'tcx> {
/// All regions of `ty` must be of kind `ReVar` and must represent
/// universal regions *external* to the closure.
pub fn bind(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Self {
let inner = tcx.fold_regions(ty, |r, depth| match r.kind() {
let inner = fold_regions(tcx, ty, |r, depth| match r.kind() {
ty::ReVar(vid) => {
let br = ty::BoundRegion {
var: ty::BoundVar::new(vid.index()),
@ -334,7 +335,7 @@ impl<'tcx> ClosureOutlivesSubjectTy<'tcx> {
tcx: TyCtxt<'tcx>,
mut map: impl FnMut(ty::RegionVid) -> ty::Region<'tcx>,
) -> Ty<'tcx> {
tcx.fold_regions(self.inner, |r, depth| match r.kind() {
fold_regions(tcx, self.inner, |r, depth| match r.kind() {
ty::ReBound(debruijn, br) => {
debug_assert_eq!(debruijn, depth);
map(ty::RegionVid::new(br.var.index()))

83
compiler/rustc_middle/src/ty/fold.rs
View file

@ -2,9 +2,9 @@ use rustc_data_structures::fx::FxIndexMap;
use rustc_hir::def_id::DefId;
use rustc_type_ir::data_structures::DelayedMap;
pub use rustc_type_ir::fold::{
FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable, shift_region, shift_vars,
FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable, fold_regions, shift_region,
shift_vars,
};
use tracing::{debug, instrument};
use crate::ty::{self, Binder, BoundTy, Ty, TyCtxt, TypeVisitableExt};
@ -50,85 +50,6 @@ where
}
}
///////////////////////////////////////////////////////////////////////////
// Region folder
impl<'tcx> TyCtxt<'tcx> {
/// Folds the escaping and free regions in `value` using `f`.
pub fn fold_regions<T>(
self,
value: T,
mut f: impl FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
) -> T
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
value.fold_with(&mut RegionFolder::new(self, &mut f))
}
}
/// Folds over the substructure of a type, visiting its component
/// types and all regions that occur *free* within it.
///
/// That is, function pointer types and trait object can introduce
/// new bound regions which are not visited by this visitors as
/// they are not free; only regions that occur free will be
/// visited by `fld_r`.
pub struct RegionFolder<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
/// Stores the index of a binder *just outside* the stuff we have
/// visited. So this begins as INNERMOST; when we pass through a
/// binder, it is incremented (via `shift_in`).
current_index: ty::DebruijnIndex,
/// Callback invokes for each free region. The `DebruijnIndex`
/// points to the binder *just outside* the ones we have passed
/// through.
fold_region_fn:
&'a mut (dyn FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx> + 'a),
}
impl<'a, 'tcx> RegionFolder<'a, 'tcx> {
#[inline]
pub fn new(
tcx: TyCtxt<'tcx>,
fold_region_fn: &'a mut dyn FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
) -> RegionFolder<'a, 'tcx> {
RegionFolder { tcx, current_index: ty::INNERMOST, fold_region_fn }
}
}
impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
fn cx(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
&mut self,
t: ty::Binder<'tcx, T>,
) -> ty::Binder<'tcx, T> {
self.current_index.shift_in(1);
let t = t.super_fold_with(self);
self.current_index.shift_out(1);
t
}
#[instrument(skip(self), level = "debug", ret)]
fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
match *r {
ty::ReBound(debruijn, _) if debruijn < self.current_index => {
debug!(?self.current_index, "skipped bound region");
r
}
_ => {
debug!(?self.current_index, "folding free region");
(self.fold_region_fn)(r, self.current_index)
}
}
}
}
///////////////////////////////////////////////////////////////////////////
// Bound vars replacer

3
compiler/rustc_middle/src/ty/util.rs
View file

@ -21,6 +21,7 @@ use tracing::{debug, instrument};
use super::TypingEnv;
use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
use crate::query::Providers;
use crate::ty::fold::fold_regions;
use crate::ty::layout::{FloatExt, IntegerExt};
use crate::ty::{
self, Asyncness, FallibleTypeFolder, GenericArgKind, GenericArgsRef, Ty, TyCtxt, TypeFoldable,
@ -735,7 +736,7 @@ impl<'tcx> TyCtxt<'tcx> {
.filter(|decl| !decl.ignore_for_traits)
.map(move |decl| {
let mut vars = vec![];
let ty = self.fold_regions(decl.ty, |re, debruijn| {
let ty = fold_regions(self, decl.ty, |re, debruijn| {
assert_eq!(re, self.lifetimes.re_erased);
let var = ty::BoundVar::from_usize(vars.len());
vars.push(ty::BoundVariableKind::Region(ty::BoundRegionKind::Anon));

3
compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/util.rs
View file

@ -3,6 +3,7 @@
use rustc_hir as hir;
use rustc_hir::def_id::LocalDefId;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, Binder, Region, Ty, TyCtxt, TypeFoldable};
use rustc_span::Span;
use tracing::instrument;
@ -83,7 +84,7 @@ pub fn find_param_with_region<'tcx>(
// May return None; sometimes the tables are not yet populated.
let ty = fn_sig.inputs()[index];
let mut found_anon_region = false;
let new_param_ty = tcx.fold_regions(ty, |r, _| {
let new_param_ty = fold_regions(tcx, ty, |r, _| {
if r == anon_region {
found_anon_region = true;
replace_region

3
compiler/rustc_trait_selection/src/traits/select/mod.rs
View file

@ -25,6 +25,7 @@ use rustc_middle::dep_graph::{DepNodeIndex, dep_kinds};
pub use rustc_middle::traits::select::*;
use rustc_middle::ty::abstract_const::NotConstEvaluatable;
use rustc_middle::ty::error::TypeErrorToStringExt;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::print::{PrintTraitRefExt as _, with_no_trimmed_paths};
use rustc_middle::ty::{
self, GenericArgsRef, PolyProjectionPredicate, Ty, TyCtxt, TypeFoldable, TypeVisitableExt,
@ -3209,7 +3210,7 @@ fn bind_coroutine_hidden_types_above<'tcx>(
// Only remap erased regions if we use them.
if considering_regions {
bty = bty.map_bound(|ty| {
tcx.fold_regions(ty, |r, current_depth| match r.kind() {
fold_regions(tcx, ty, |r, current_depth| match r.kind() {
ty::ReErased => {
let br = ty::BoundRegion {
var: ty::BoundVar::from_u32(counter),

4
compiler/rustc_ty_utils/src/implied_bounds.rs
View file

@ -6,6 +6,7 @@ use rustc_hir::def::DefKind;
use rustc_hir::def_id::LocalDefId;
use rustc_middle::bug;
use rustc_middle::query::Providers;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_span::Span;
@ -86,7 +87,8 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
}
}
// FIXME: This could use a real folder, I guess.
let remapped_wf_tys = tcx.fold_regions(
let remapped_wf_tys = fold_regions(
tcx,
tcx.assumed_wf_types(fn_def_id.expect_local()).to_vec(),
|region, _| {
// If `region` is a `ReLateParam` that is captured by the

3
compiler/rustc_ty_utils/src/ty.rs
View file

@ -5,6 +5,7 @@ use rustc_hir::def::DefKind;
use rustc_index::bit_set::BitSet;
use rustc_middle::bug;
use rustc_middle::query::Providers;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{
self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, Upcast,
};
@ -197,7 +198,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ImplTraitInTraitFinder<'_, 'tcx> {
// We have entered some binders as we've walked into the
// bounds of the RPITIT. Shift these binders back out when
// constructing the top-level projection predicate.
let shifted_alias_ty = self.tcx.fold_regions(unshifted_alias_ty, |re, depth| {
let shifted_alias_ty = fold_regions(self.tcx, unshifted_alias_ty, |re, depth| {
if let ty::ReBound(index, bv) = re.kind() {
if depth != ty::INNERMOST {
return ty::Region::new_error_with_message(

74
compiler/rustc_type_ir/src/fold.rs
View file

@ -49,7 +49,7 @@ use std::mem;
use rustc_index::{Idx, IndexVec};
use thin_vec::ThinVec;
use tracing::instrument;
use tracing::{debug, instrument};
use crate::data_structures::Lrc;
use crate::inherent::*;
@ -431,3 +431,75 @@ where
value.fold_with(&mut Shifter::new(cx, amount))
}
}
///////////////////////////////////////////////////////////////////////////
// Region folder
pub fn fold_regions<I: Interner, T>(
cx: I,
value: T,
mut f: impl FnMut(I::Region, ty::DebruijnIndex) -> I::Region,
) -> T
where
T: TypeFoldable<I>,
{
value.fold_with(&mut RegionFolder::new(cx, &mut f))
}
/// Folds over the substructure of a type, visiting its component
/// types and all regions that occur *free* within it.
///
/// That is, function pointer types and trait object can introduce
/// new bound regions which are not visited by this visitors as
/// they are not free; only regions that occur free will be
/// visited by `fld_r`.
pub struct RegionFolder<'a, I: Interner> {
cx: I,
/// Stores the index of a binder *just outside* the stuff we have
/// visited. So this begins as INNERMOST; when we pass through a
/// binder, it is incremented (via `shift_in`).
current_index: ty::DebruijnIndex,
/// Callback invokes for each free region. The `DebruijnIndex`
/// points to the binder *just outside* the ones we have passed
/// through.
fold_region_fn: &'a mut (dyn FnMut(I::Region, ty::DebruijnIndex) -> I::Region + 'a),
}
impl<'a, I: Interner> RegionFolder<'a, I> {
#[inline]
pub fn new(
cx: I,
fold_region_fn: &'a mut dyn FnMut(I::Region, ty::DebruijnIndex) -> I::Region,
) -> RegionFolder<'a, I> {
RegionFolder { cx, current_index: ty::INNERMOST, fold_region_fn }
}
}
impl<'a, I: Interner> TypeFolder<I> for RegionFolder<'a, I> {
fn cx(&self) -> I {
self.cx
}
fn fold_binder<T: TypeFoldable<I>>(&mut self, t: ty::Binder<I, T>) -> ty::Binder<I, T> {
self.current_index.shift_in(1);
let t = t.super_fold_with(self);
self.current_index.shift_out(1);
t
}
#[instrument(skip(self), level = "debug", ret)]
fn fold_region(&mut self, r: I::Region) -> I::Region {
match r.kind() {
ty::ReBound(debruijn, _) if debruijn < self.current_index => {
debug!(?self.current_index, "skipped bound region");
r
}
_ => {
debug!(?self.current_index, "folding free region");
(self.fold_region_fn)(r, self.current_index)
}
}
}
}

3
src/librustdoc/clean/auto_trait.rs
View file

@ -2,6 +2,7 @@ use rustc_data_structures::fx::{FxIndexMap, FxIndexSet, IndexEntry};
use rustc_hir as hir;
use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
use rustc_middle::bug;
use rustc_middle::ty::fold::fold_regions;
use rustc_middle::ty::{self, Region, Ty};
use rustc_span::def_id::DefId;
use rustc_span::symbol::{Symbol, kw};
@ -182,7 +183,7 @@ fn clean_param_env<'tcx>(
.is_some_and(|pred| tcx.lang_items().sized_trait() == Some(pred.def_id()))
})
.map(|pred| {
tcx.fold_regions(pred, |r, _| match *r {
fold_regions(tcx, pred, |r, _| match *r {
// FIXME: Don't `unwrap_or`, I think we should panic if we encounter an infer var that
// we can't map to a concrete region. However, `AutoTraitFinder` *does* leak those kinds
// of `ReVar`s for some reason at the time of writing. See `rustdoc-ui/` tests.