diff --git a/src/librustc_mir/borrow_check/borrow_set.rs b/src/librustc_mir/borrow_check/borrow_set.rs
index fd7dc7fc4bd3a..947c32df0f6a3 100644
--- a/src/librustc_mir/borrow_check/borrow_set.rs
+++ b/src/librustc_mir/borrow_check/borrow_set.rs
@@ -16,7 +16,7 @@ use rustc::mir::traversal;
use rustc::mir::visit::{
PlaceContext, Visitor, NonUseContext, MutatingUseContext, NonMutatingUseContext
};
-use rustc::mir::{self, Location, Mir, Place, Local};
+use rustc::mir::{self, Location, Mir, Local};
use rustc::ty::{RegionVid, TyCtxt};
use rustc::util::nodemap::{FxHashMap, FxHashSet};
use rustc_data_structures::indexed_vec::IndexVec;
@@ -41,10 +41,6 @@ crate struct BorrowSet<'tcx> {
/// only need to store one borrow index
crate activation_map: FxHashMap<Location, Vec<BorrowIndex>>,
- /// Every borrow has a region; this maps each such regions back to
- /// its borrow-indexes.
- crate region_map: FxHashMap<RegionVid, FxHashSet<BorrowIndex>>,
-
/// Map from local to all the borrows on that local
crate local_map: FxHashMap<mir::Local, FxHashSet<BorrowIndex>>,
@@ -149,7 +145,6 @@ impl<'tcx> BorrowSet<'tcx> {
idx_vec: IndexVec::new(),
location_map: Default::default(),
activation_map: Default::default(),
- region_map: Default::default(),
local_map: Default::default(),
pending_activations: Default::default(),
locals_state_at_exit:
@@ -164,7 +159,6 @@ impl<'tcx> BorrowSet<'tcx> {
borrows: visitor.idx_vec,
location_map: visitor.location_map,
activation_map: visitor.activation_map,
- region_map: visitor.region_map,
local_map: visitor.local_map,
locals_state_at_exit: visitor.locals_state_at_exit,
}
@@ -184,7 +178,6 @@ struct GatherBorrows<'a, 'gcx: 'tcx, 'tcx: 'a> {
idx_vec: IndexVec<BorrowIndex, BorrowData<'tcx>>,
location_map: FxHashMap<Location, BorrowIndex>,
activation_map: FxHashMap<Location, Vec<BorrowIndex>>,
- region_map: FxHashMap<RegionVid, FxHashSet<BorrowIndex>>,
local_map: FxHashMap<mir::Local, FxHashSet<BorrowIndex>>,
/// When we encounter a 2-phase borrow statement, it will always
@@ -229,7 +222,6 @@ impl<'a, 'gcx, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'gcx, 'tcx> {
self.insert_as_pending_if_two_phase(location, &assigned_place, kind, idx);
- self.region_map.entry(region).or_default().insert(idx);
if let Some(local) = borrowed_place.root_local() {
self.local_map.entry(local).or_default().insert(idx);
}
@@ -238,68 +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)
+ }
+ };
}
}
diff --git a/src/librustc_mir/dataflow/impls/borrows.rs b/src/librustc_mir/dataflow/impls/borrows.rs
index 27bc28ac81d84..3a9e4fc9e4ab9 100644
--- a/src/librustc_mir/dataflow/impls/borrows.rs
+++ b/src/librustc_mir/dataflow/impls/borrows.rs
@@ -246,7 +246,7 @@ impl<'a, 'gcx, 'tcx> BitDenotation for Borrows<'a, 'gcx, 'tcx> {
// re-consider the current implementations of the
// propagate_call_return method.
- if let mir::Rvalue::Ref(region, _, ref place) = **rhs {
+ if let mir::Rvalue::Ref(_, _, ref place) = **rhs {
if place.ignore_borrow(
self.tcx,
self.mir,
@@ -258,13 +258,6 @@ impl<'a, 'gcx, 'tcx> BitDenotation for Borrows<'a, 'gcx, 'tcx> {
panic!("could not find BorrowIndex for location {:?}", location);
});
- assert!(self.borrow_set.region_map
- .get(®ion.to_region_vid())
- .unwrap_or_else(|| {
- panic!("could not find BorrowIndexs for RegionVid {:?}", region);
- })
- .contains(&index)
- );
sets.gen(*index);
// Issue #46746: Two-phase borrows handles
diff --git a/src/librustc_mir/transform/cleanup_post_borrowck.rs b/src/librustc_mir/transform/cleanup_post_borrowck.rs
index c0edd3926d32d..6d7fc404edbb1 100644
--- a/src/librustc_mir/transform/cleanup_post_borrowck.rs
+++ b/src/librustc_mir/transform/cleanup_post_borrowck.rs
@@ -10,17 +10,25 @@
//! This module provides two passes:
//!
-//! - [CleanAscribeUserType], that replaces all
-//! [StatementKind::AscribeUserType] statements with [StatementKind::Nop].
-//! - [CleanFakeReadsAndBorrows], that replaces all [FakeRead] statements and
-//! borrows that are read by [FakeReadCause::ForMatchGuard] fake reads with
-//! [StatementKind::Nop].
+//! - [`CleanAscribeUserType`], that replaces all [`AscribeUserType`]
+//! statements with [`Nop`].
+//! - [`CleanFakeReadsAndBorrows`], that replaces all [`FakeRead`] statements
+//! and borrows that are read by [`ForMatchGuard`] fake reads with [`Nop`].
//!
-//! The [CleanFakeReadsAndBorrows] "pass" is actually implemented as two
+//! The `CleanFakeReadsAndBorrows` "pass" is actually implemented as two
//! traversals (aka visits) of the input MIR. The first traversal,
-//! [DeleteAndRecordFakeReads], deletes the fake reads and finds the temporaries
-//! read by [ForMatchGuard] reads, and [DeleteFakeBorrows] deletes the
-//! initialization of those temporaries.
+//! [`DeleteAndRecordFakeReads`], deletes the fake reads and finds the
+//! temporaries read by [`ForMatchGuard`] reads, and [`DeleteFakeBorrows`]
+//! deletes the initialization of those temporaries.
+//!
+//! [`CleanAscribeUserType`]: cleanup_post_borrowck::CleanAscribeUserType
+//! [`CleanFakeReadsAndBorrows`]: cleanup_post_borrowck::CleanFakeReadsAndBorrows
+//! [`DeleteAndRecordFakeReads`]: cleanup_post_borrowck::DeleteAndRecordFakeReads
+//! [`DeleteFakeBorrows`]: cleanup_post_borrowck::DeleteFakeBorrows
+//! [`AscribeUserType`]: rustc::mir::StatementKind::AscribeUserType
+//! [`Nop`]: rustc::mir::StatementKind::Nop
+//! [`FakeRead`]: rustc::mir::StatementKind::FakeRead
+//! [`ForMatchGuard`]: rustc::mir::FakeReadCause::ForMatchGuard
use rustc_data_structures::fx::FxHashSet;