diff options
Diffstat (limited to 'src/librustc_mir/dataflow/impls/borrows.rs')
| -rw-r--r-- | src/librustc_mir/dataflow/impls/borrows.rs | 123 |
1 files changed, 56 insertions, 67 deletions
diff --git a/src/librustc_mir/dataflow/impls/borrows.rs b/src/librustc_mir/dataflow/impls/borrows.rs index 5433b7f5f74..30eccebd331 100644 --- a/src/librustc_mir/dataflow/impls/borrows.rs +++ b/src/librustc_mir/dataflow/impls/borrows.rs @@ -1,14 +1,14 @@ -use rustc::mir::{self, Location, Place, PlaceBase, Body}; -use rustc::ty::{self, TyCtxt}; +use rustc::mir::{self, Body, Location, Place, PlaceBase}; use rustc::ty::RegionVid; +use rustc::ty::{self, TyCtxt}; -use rustc_index::bit_set::BitSet; use rustc_data_structures::fx::FxHashMap; +use rustc_index::bit_set::BitSet; use rustc_index::vec::{Idx, IndexVec}; use crate::borrow_check::{ - ToRegionVid, BorrowSet, BorrowData, RegionInferenceContext, PlaceExt, PlaceConflictBias, - places_conflict, + places_conflict, BorrowData, BorrowSet, PlaceConflictBias, PlaceExt, RegionInferenceContext, + ToRegionVid, }; use crate::dataflow::{BitDenotation, BottomValue, GenKillSet}; @@ -43,7 +43,7 @@ struct StackEntry { bb: mir::BasicBlock, lo: usize, hi: usize, - first_part_only: bool + first_part_only: bool, } fn precompute_borrows_out_of_scope<'tcx>( @@ -77,16 +77,13 @@ fn precompute_borrows_out_of_scope<'tcx>( while let Some(StackEntry { bb, lo, hi, first_part_only }) = stack.pop() { let mut finished_early = first_part_only; - for i in lo ..= hi { + for i in lo..=hi { let location = Location { block: bb, statement_index: i }; // If region does not contain a point at the location, then add to list and skip // successor locations. if !regioncx.region_contains(borrow_region, location) { debug!("borrow {:?} gets killed at {:?}", borrow_index, location); - borrows_out_of_scope_at_location - .entry(location) - .or_default() - .push(borrow_index); + borrows_out_of_scope_at_location.entry(location).or_default().push(borrow_index); finished_early = true; break; } @@ -97,7 +94,8 @@ fn precompute_borrows_out_of_scope<'tcx>( let bb_data = &body[bb]; assert!(hi == bb_data.statements.len()); for &succ_bb in bb_data.terminator().successors() { - visited.entry(succ_bb) + visited + .entry(succ_bb) .and_modify(|lo| { // `succ_bb` has been seen before. If it wasn't // fully processed, add its first part to `stack` @@ -145,9 +143,14 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { let borrow_region = borrow_data.region.to_region_vid(); let location = borrow_set.borrows[borrow_index].reserve_location; - precompute_borrows_out_of_scope(body, &nonlexical_regioncx, - &mut borrows_out_of_scope_at_location, - borrow_index, borrow_region, location); + precompute_borrows_out_of_scope( + body, + &nonlexical_regioncx, + &mut borrows_out_of_scope_at_location, + borrow_index, + borrow_region, + location, + ); } Borrows { @@ -160,7 +163,9 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { } } - crate fn borrows(&self) -> &IndexVec<BorrowIndex, BorrowData<'tcx>> { &self.borrow_set.borrows } + crate fn borrows(&self) -> &IndexVec<BorrowIndex, BorrowData<'tcx>> { + &self.borrow_set.borrows + } pub fn location(&self, idx: BorrowIndex) -> &Location { &self.borrow_set.borrows[idx].reserve_location @@ -168,9 +173,11 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { /// Add all borrows to the kill set, if those borrows are out of scope at `location`. /// That means they went out of a nonlexical scope - fn kill_loans_out_of_scope_at_location(&self, - trans: &mut GenKillSet<BorrowIndex>, - location: Location) { + fn kill_loans_out_of_scope_at_location( + &self, + trans: &mut GenKillSet<BorrowIndex>, + location: Location, + ) { // NOTE: The state associated with a given `location` // reflects the dataflow on entry to the statement. // Iterate over each of the borrows that we've precomputed @@ -188,20 +195,12 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { } /// Kill any borrows that conflict with `place`. - fn kill_borrows_on_place( - &self, - trans: &mut GenKillSet<BorrowIndex>, - place: &Place<'tcx> - ) { + fn kill_borrows_on_place(&self, trans: &mut GenKillSet<BorrowIndex>, place: &Place<'tcx>) { debug!("kill_borrows_on_place: place={:?}", place); if let PlaceBase::Local(local) = place.base { - let other_borrows_of_local = self - .borrow_set - .local_map - .get(&local) - .into_iter() - .flat_map(|bs| bs.into_iter()); + let other_borrows_of_local = + self.borrow_set.local_map.get(&local).into_iter().flat_map(|bs| bs.into_iter()); // If the borrowed place is a local with no projections, all other borrows of this // local must conflict. This is purely an optimization so we don't have to call @@ -217,16 +216,16 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { // pair of array indices are unequal, so that when `places_conflict` returns true, we // will be assured that two places being compared definitely denotes the same sets of // locations. - let definitely_conflicting_borrows = other_borrows_of_local - .filter(|&&i| { - places_conflict( - self.tcx, - self.param_env, - self.body, - &self.borrow_set.borrows[i].borrowed_place, - place, - PlaceConflictBias::NoOverlap) - }); + let definitely_conflicting_borrows = other_borrows_of_local.filter(|&&i| { + places_conflict( + self.tcx, + self.param_env, + self.body, + &self.borrow_set.borrows[i].borrowed_place, + place, + PlaceConflictBias::NoOverlap, + ) + }); trans.kill_all(definitely_conflicting_borrows); } @@ -235,7 +234,9 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> { impl<'a, 'tcx> BitDenotation<'tcx> for Borrows<'a, 'tcx> { type Idx = BorrowIndex; - fn name() -> &'static str { "borrows" } + fn name() -> &'static str { + "borrows" + } fn bits_per_block(&self) -> usize { self.borrow_set.borrows.len() * 2 } @@ -245,19 +246,13 @@ impl<'a, 'tcx> BitDenotation<'tcx> for Borrows<'a, 'tcx> { // function execution, so this method has no effect. } - fn before_statement_effect(&self, - trans: &mut GenKillSet<Self::Idx>, - location: Location) { - debug!("Borrows::before_statement_effect trans: {:?} location: {:?}", - trans, location); + fn before_statement_effect(&self, trans: &mut GenKillSet<Self::Idx>, location: Location) { + debug!("Borrows::before_statement_effect trans: {:?} location: {:?}", trans, location); self.kill_loans_out_of_scope_at_location(trans, location); } - fn statement_effect(&self, - trans: &mut GenKillSet<Self::Idx>, - location: Location) { - debug!("Borrows::statement_effect: trans={:?} location={:?}", - trans, location); + fn statement_effect(&self, trans: &mut GenKillSet<Self::Idx>, location: Location) { + debug!("Borrows::statement_effect: trans={:?} location={:?}", trans, location); let block = &self.body.basic_blocks().get(location.block).unwrap_or_else(|| { panic!("could not find block at location {:?}", location); @@ -268,7 +263,7 @@ impl<'a, 'tcx> BitDenotation<'tcx> for Borrows<'a, 'tcx> { debug!("Borrows::statement_effect: stmt={:?}", stmt); match stmt.kind { - mir::StatementKind::Assign(box(ref lhs, ref rhs)) => { + mir::StatementKind::Assign(box (ref lhs, ref rhs)) => { if let mir::Rvalue::Ref(_, _, ref place) = *rhs { if place.ignore_borrow( self.tcx, @@ -303,27 +298,21 @@ impl<'a, 'tcx> BitDenotation<'tcx> for Borrows<'a, 'tcx> { } } - mir::StatementKind::FakeRead(..) | - mir::StatementKind::SetDiscriminant { .. } | - mir::StatementKind::StorageLive(..) | - mir::StatementKind::Retag { .. } | - mir::StatementKind::AscribeUserType(..) | - mir::StatementKind::Nop => {} - + mir::StatementKind::FakeRead(..) + | mir::StatementKind::SetDiscriminant { .. } + | mir::StatementKind::StorageLive(..) + | mir::StatementKind::Retag { .. } + | mir::StatementKind::AscribeUserType(..) + | mir::StatementKind::Nop => {} } } - fn before_terminator_effect(&self, - trans: &mut GenKillSet<Self::Idx>, - location: Location) { - debug!("Borrows::before_terminator_effect: trans={:?} location={:?}", - trans, location); + fn before_terminator_effect(&self, trans: &mut GenKillSet<Self::Idx>, location: Location) { + debug!("Borrows::before_terminator_effect: trans={:?} location={:?}", trans, location); self.kill_loans_out_of_scope_at_location(trans, location); } - fn terminator_effect(&self, - _: &mut GenKillSet<Self::Idx>, - _: Location) {} + fn terminator_effect(&self, _: &mut GenKillSet<Self::Idx>, _: Location) {} fn propagate_call_return( &self, |