diff options
Diffstat (limited to 'compiler/rustc_borrowck/src/universal_regions.rs')
| -rw-r--r-- | compiler/rustc_borrowck/src/universal_regions.rs | 133 |
1 files changed, 96 insertions, 37 deletions
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs index 2beb5e0ab..a4a0c5b90 100644 --- a/compiler/rustc_borrowck/src/universal_regions.rs +++ b/compiler/rustc_borrowck/src/universal_regions.rs @@ -22,7 +22,9 @@ use rustc_hir::{BodyOwnerKind, HirId}; use rustc_index::vec::{Idx, IndexVec}; use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin}; use rustc_middle::ty::fold::TypeFoldable; -use rustc_middle::ty::{self, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt}; +use rustc_middle::ty::{ + self, DefIdTree, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt, +}; use rustc_middle::ty::{InternalSubsts, SubstsRef}; use std::iter; @@ -241,7 +243,7 @@ impl<'tcx> UniversalRegions<'tcx> { tcx: TyCtxt<'tcx>, closure_substs: SubstsRef<'tcx>, expected_num_vars: usize, - typeck_root_def_id: DefId, + closure_def_id: LocalDefId, ) -> IndexVec<RegionVid, ty::Region<'tcx>> { let mut region_mapping = IndexVec::with_capacity(expected_num_vars); region_mapping.push(tcx.lifetimes.re_static); @@ -249,7 +251,7 @@ impl<'tcx> UniversalRegions<'tcx> { region_mapping.push(fr); }); - for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| { + for_each_late_bound_region_in_recursive_scope(tcx, tcx.local_parent(closure_def_id), |r| { region_mapping.push(r); }); @@ -339,9 +341,8 @@ impl<'tcx> UniversalRegions<'tcx> { // tests, and the resulting print-outs include def-ids // and other things that are not stable across tests! // So we just include the region-vid. Annoying. - let typeck_root_def_id = tcx.typeck_root_def_id(def_id); - for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| { - err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),)); + for_each_late_bound_region_in_recursive_scope(tcx, def_id.expect_local(), |r| { + err.note(&format!("late-bound region is {:?}", self.to_region_vid(r))); }); } DefiningTy::Generator(def_id, substs, _) => { @@ -354,9 +355,8 @@ impl<'tcx> UniversalRegions<'tcx> { // FIXME: As above, we'd like to print out the region // `r` but doing so is not stable across architectures // and so forth. - let typeck_root_def_id = tcx.typeck_root_def_id(def_id); - for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| { - err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),)); + for_each_late_bound_region_in_recursive_scope(tcx, def_id.expect_local(), |r| { + err.note(&format!("late-bound region is {:?}", self.to_region_vid(r))); }); } DefiningTy::FnDef(def_id, substs) => { @@ -421,13 +421,24 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> { first_extern_index } else { // If this is a closure, generator, or inline-const, then the late-bound regions from the enclosing - // function are actually external regions to us. For example, here, 'a is not local + // function/closures are actually external regions to us. For example, here, 'a is not local // to the closure c (although it is local to the fn foo): // fn foo<'a>() { // let c = || { let x: &'a u32 = ...; } // } - self.infcx - .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices); + for_each_late_bound_region_in_recursive_scope( + self.infcx.tcx, + self.infcx.tcx.local_parent(self.mir_def.did), + |r| { + debug!(?r); + if !indices.indices.contains_key(&r) { + let region_vid = self.infcx.next_nll_region_var(FR); + debug!(?region_vid); + indices.insert_late_bound_region(r, region_vid.to_region_vid()); + } + }, + ); + // Any regions created during the execution of `defining_ty` or during the above // late-bound region replacement are all considered 'extern' regions self.infcx.num_region_vars() @@ -444,12 +455,16 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> { bound_inputs_and_output, &mut indices, ); - // Converse of above, if this is a function then the late-bound regions declared on its - // signature are local to the fn. - if self.mir_def.did.to_def_id() == typeck_root_def_id { - self.infcx - .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices); - } + // Converse of above, if this is a function/closure then the late-bound regions declared on its + // signature are local. + for_each_late_bound_region_in_item(self.infcx.tcx, self.mir_def.did, |r| { + debug!(?r); + if !indices.indices.contains_key(&r) { + let region_vid = self.infcx.next_nll_region_var(FR); + debug!(?region_vid); + indices.insert_late_bound_region(r, region_vid.to_region_vid()); + } + }); let (unnormalized_output_ty, mut unnormalized_input_tys) = inputs_and_output.split_last().unwrap(); @@ -572,9 +587,9 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> { let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.did.to_def_id()); let identity_substs = InternalSubsts::identity_for_item(tcx, typeck_root_def_id); let fr_substs = match defining_ty { - DefiningTy::Closure(_, ref substs) - | DefiningTy::Generator(_, ref substs, _) - | DefiningTy::InlineConst(_, ref substs) => { + DefiningTy::Closure(_, substs) + | DefiningTy::Generator(_, substs, _) + | DefiningTy::InlineConst(_, substs) => { // In the case of closures, we rely on the fact that // the first N elements in the ClosureSubsts are // inherited from the `typeck_root_def_id`. @@ -692,7 +707,13 @@ trait InferCtxtExt<'tcx> { where T: TypeFoldable<'tcx>; - fn replace_late_bound_regions_with_nll_infer_vars( + fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope( + &self, + mir_def_id: LocalDefId, + indices: &mut UniversalRegionIndices<'tcx>, + ); + + fn replace_late_bound_regions_with_nll_infer_vars_in_item( &self, mir_def_id: LocalDefId, indices: &mut UniversalRegionIndices<'tcx>, @@ -746,13 +767,28 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { /// set of late-bound regions and checks for any that we have not yet seen, adding them to the /// inputs vector. #[instrument(skip(self, indices))] - fn replace_late_bound_regions_with_nll_infer_vars( + fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope( + &self, + mir_def_id: LocalDefId, + indices: &mut UniversalRegionIndices<'tcx>, + ) { + for_each_late_bound_region_in_recursive_scope(self.tcx, mir_def_id, |r| { + debug!(?r); + if !indices.indices.contains_key(&r) { + let region_vid = self.next_nll_region_var(FR); + debug!(?region_vid); + indices.insert_late_bound_region(r, region_vid.to_region_vid()); + } + }); + } + + #[instrument(skip(self, indices))] + fn replace_late_bound_regions_with_nll_infer_vars_in_item( &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| { + for_each_late_bound_region_in_item(self.tcx, mir_def_id, |r| { debug!(?r); if !indices.indices.contains_key(&r) { let region_vid = self.next_nll_region_var(FR); @@ -803,21 +839,44 @@ impl<'tcx> UniversalRegionIndices<'tcx> { } } -/// Iterates over the late-bound regions defined on fn_def_id and -/// invokes `f` with the liberated form of each one. -fn for_each_late_bound_region_defined_on<'tcx>( +/// Iterates over the late-bound regions defined on `mir_def_id` and all of its +/// parents, up to the typeck root, and invokes `f` with the liberated form +/// of each one. +fn for_each_late_bound_region_in_recursive_scope<'tcx>( tcx: TyCtxt<'tcx>, - fn_def_id: DefId, + mut mir_def_id: LocalDefId, mut f: impl FnMut(ty::Region<'tcx>), ) { - if let Some(late_bounds) = tcx.is_late_bound_map(fn_def_id.expect_local()) { - for ®ion_def_id in late_bounds.iter() { - let name = tcx.item_name(region_def_id.to_def_id()); - let liberated_region = tcx.mk_region(ty::ReFree(ty::FreeRegion { - scope: fn_def_id, - bound_region: ty::BoundRegionKind::BrNamed(region_def_id.to_def_id(), name), - })); - f(liberated_region); + let typeck_root_def_id = tcx.typeck_root_def_id(mir_def_id.to_def_id()); + + // Walk up the tree, collecting late-bound regions until we hit the typeck root + loop { + for_each_late_bound_region_in_item(tcx, mir_def_id, &mut f); + + if mir_def_id.to_def_id() == typeck_root_def_id { + break; + } else { + mir_def_id = tcx.local_parent(mir_def_id); } } } + +/// Iterates over the late-bound regions defined on `mir_def_id` and all of its +/// parents, up to the typeck root, and invokes `f` with the liberated form +/// of each one. +fn for_each_late_bound_region_in_item<'tcx>( + tcx: TyCtxt<'tcx>, + mir_def_id: LocalDefId, + mut f: impl FnMut(ty::Region<'tcx>), +) { + if !tcx.def_kind(mir_def_id).is_fn_like() { + return; + } + + for bound_var in tcx.late_bound_vars(tcx.hir().local_def_id_to_hir_id(mir_def_id)) { + let ty::BoundVariableKind::Region(bound_region) = bound_var else { continue; }; + let liberated_region = tcx + .mk_region(ty::ReFree(ty::FreeRegion { scope: mir_def_id.to_def_id(), bound_region })); + f(liberated_region); + } +} |