From 6000c2e0e16ee60078a3e2810ff3d26639bdeff5 Mon Sep 17 00:00:00 2001 From: Matthew Jasper Date: Fri, 30 Nov 2018 21:49:43 +0000 Subject: [PATCH] Use visit_local to find 2PB activations --- src/librustc_mir/borrow_check/borrow_set.rs | 110 ++++++++++---------- 1 file changed, 55 insertions(+), 55 deletions(-) diff --git a/src/librustc_mir/borrow_check/borrow_set.rs b/src/librustc_mir/borrow_check/borrow_set.rs index a6af79ffbe922..947c32df0f6a3 100644 --- a/src/librustc_mir/borrow_check/borrow_set.rs +++ b/src/librustc_mir/borrow_check/borrow_set.rs @@ -230,68 +230,68 @@ impl<'a, 'gcx, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'gcx, 'tcx> { self.super_assign(block, assigned_place, rvalue, location) } - fn visit_place( + fn visit_local( &mut self, - place: &mir::Place<'tcx>, + temp: &Local, context: PlaceContext<'tcx>, location: Location, ) { - self.super_place(place, context, location); - - // We found a use of some temporary TEMP... - if let Place::Local(temp) = place { - // ... check whether we (earlier) saw a 2-phase borrow like - // - // TMP = &mut place - if let Some(&borrow_index) = self.pending_activations.get(temp) { - let borrow_data = &mut self.idx_vec[borrow_index]; - - // Watch out: the use of TMP in the borrow itself - // doesn't count as an activation. =) - if borrow_data.reserve_location == location && - context == PlaceContext::MutatingUse(MutatingUseContext::Store) - { - return; - } + if !context.is_use() { + return; + } - if let TwoPhaseActivation::ActivatedAt(other_location) = - borrow_data.activation_location { - span_bug!( - self.mir.source_info(location).span, - "found two uses for 2-phase borrow temporary {:?}: \ - {:?} and {:?}", - temp, - location, - other_location, - ); - } + // We found a use of some temporary TMP + // check whether we (earlier) saw a 2-phase borrow like + // + // TMP = &mut place + if let Some(&borrow_index) = self.pending_activations.get(temp) { + let borrow_data = &mut self.idx_vec[borrow_index]; - // Otherwise, this is the unique later use - // that we expect. - borrow_data.activation_location = match context { - // The use of TMP in a shared borrow does not - // count as an actual activation. - PlaceContext::NonMutatingUse(NonMutatingUseContext::SharedBorrow(..)) | - PlaceContext::NonMutatingUse(NonMutatingUseContext::ShallowBorrow(..)) => - TwoPhaseActivation::NotActivated, - _ => { - // Double check: This borrow is indeed a two-phase borrow (that is, - // we are 'transitioning' from `NotActivated` to `ActivatedAt`) and - // we've not found any other activations (checked above). - assert_eq!( - borrow_data.activation_location, - TwoPhaseActivation::NotActivated, - "never found an activation for this borrow!", - ); - - self.activation_map - .entry(location) - .or_default() - .push(borrow_index); - TwoPhaseActivation::ActivatedAt(location) - } - }; + // Watch out: the use of TMP in the borrow itself + // doesn't count as an activation. =) + if borrow_data.reserve_location == location && + context == PlaceContext::MutatingUse(MutatingUseContext::Store) + { + return; } + + if let TwoPhaseActivation::ActivatedAt(other_location) = + borrow_data.activation_location { + span_bug!( + self.mir.source_info(location).span, + "found two uses for 2-phase borrow temporary {:?}: \ + {:?} and {:?}", + temp, + location, + other_location, + ); + } + + // Otherwise, this is the unique later use + // that we expect. + borrow_data.activation_location = match context { + // The use of TMP in a shared borrow does not + // count as an actual activation. + PlaceContext::NonMutatingUse(NonMutatingUseContext::SharedBorrow(..)) | + PlaceContext::NonMutatingUse(NonMutatingUseContext::ShallowBorrow(..)) => + TwoPhaseActivation::NotActivated, + _ => { + // Double check: This borrow is indeed a two-phase borrow (that is, + // we are 'transitioning' from `NotActivated` to `ActivatedAt`) and + // we've not found any other activations (checked above). + assert_eq!( + borrow_data.activation_location, + TwoPhaseActivation::NotActivated, + "never found an activation for this borrow!", + ); + + self.activation_map + .entry(location) + .or_default() + .push(borrow_index); + TwoPhaseActivation::ActivatedAt(location) + } + }; } }