Extend the BorTag GC to AllocIds

src/borrow_tracker/mod.rs

@@ -76,7 +76,7 @@ pub struct FrameState {
 }
 
 impl VisitTags for FrameState {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, _visit: &mut TagVisitor<'_>) {
  // `protected_tags` are already recorded by `GlobalStateInner`.
  }
 }
@@ -111,9 +111,9 @@ pub struct GlobalStateInner {
 }
 
 impl VisitTags for GlobalStateInner {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  for &tag in self.protected_tags.keys() {
- visit(tag);
+ visit(None, Some(tag));
  }
  // The only other candidate is base_ptr_tags, and that does not need visiting since we don't ever
  // GC the bottommost/root tag.
@@ -472,7 +472,7 @@ impl AllocState {
 }
 
 impl VisitTags for AllocState {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  match self {
  AllocState::StackedBorrows(sb) => sb.visit_tags(visit),
  AllocState::TreeBorrows(tb) => tb.visit_tags(visit),

src/borrow_tracker/stacked_borrows/mod.rs

@@ -463,9 +463,9 @@ impl Stacks {
 }
 
 impl VisitTags for Stacks {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  for tag in self.exposed_tags.iter().copied() {
- visit(tag);
+ visit(None, Some(tag));
  }
  }
 }

src/borrow_tracker/tree_borrows/tree.rs

@@ -745,10 +745,10 @@ impl Tree {
 }
 
 impl VisitTags for Tree {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  // To ensure that the root never gets removed, we visit it
  // (the `root` node of `Tree` is not an `Option<_>`)
- visit(self.nodes.get(self.root).unwrap().tag)
+ visit(None, Some(self.nodes.get(self.root).unwrap().tag))
  }
 }
 

src/concurrency/data_race.rs

@@ -694,8 +694,8 @@ pub struct VClockAlloc {
 }
 
 impl VisitTags for VClockAlloc {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {
- // No tags here.
+ fn visit_tags(&self, _visit: &mut TagVisitor<'_>) {
+ // No tags or allocIds here.
  }
 }
 
@@ -1275,7 +1275,7 @@ pub struct GlobalState {
 }
 
 impl VisitTags for GlobalState {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, _visit: &mut TagVisitor<'_>) {
  // We don't have any tags.
  }
 }

src/concurrency/init_once.rs

@@ -46,7 +46,7 @@ pub(super) struct InitOnce<'mir, 'tcx> {
 }
 
 impl<'mir, 'tcx> VisitTags for InitOnce<'mir, 'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  for waiter in self.waiters.iter() {
  waiter.callback.visit_tags(visit);
  }

src/concurrency/sync.rs

@@ -182,7 +182,7 @@ pub(crate) struct SynchronizationState<'mir, 'tcx> {
 }
 
 impl<'mir, 'tcx> VisitTags for SynchronizationState<'mir, 'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  for init_once in self.init_onces.iter() {
  init_once.visit_tags(visit);
  }

src/concurrency/thread.rs

@@ -220,7 +220,7 @@ impl<'mir, 'tcx> Thread<'mir, 'tcx> {
 }
 
 impl VisitTags for Thread<'_, '_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Thread {
  panic_payloads: panic_payload,
  last_error,
@@ -243,7 +243,7 @@ impl VisitTags for Thread<'_, '_> {
 }
 
 impl VisitTags for Frame<'_, '_, Provenance, FrameExtra<'_>> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Frame {
  return_place,
  locals,
@@ -333,7 +333,7 @@ pub struct ThreadManager<'mir, 'tcx> {
 }
 
 impl VisitTags for ThreadManager<'_, '_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let ThreadManager {
  threads,
  thread_local_alloc_ids,

src/concurrency/weak_memory.rs

@@ -109,7 +109,7 @@ pub struct StoreBufferAlloc {
 }
 
 impl VisitTags for StoreBufferAlloc {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Self { store_buffers } = self;
  for val in store_buffers
  .borrow()

src/intptrcast.rs

@@ -45,8 +45,10 @@ pub struct GlobalStateInner {
 }
 
 impl VisitTags for GlobalStateInner {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {
- // Nothing to visit here.
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
+ for id in &self.exposed {
+ id.visit_tags(visit)
+ }
  }
 }
 
@@ -63,6 +65,11 @@ impl GlobalStateInner {
 }
 
 impl<'mir, 'tcx> GlobalStateInner {
+ pub fn remove_unreachable_allocs(&mut self, live_allocs: &FxHashSet<AllocId>) {
+ self.int_to_ptr_map.retain(|(_, id)| live_allocs.contains(id));
+ self.base_addr.retain(|id, _| live_allocs.contains(id));
+ }
+
  // Returns the exposed `AllocId` that corresponds to the specified addr,
  // or `None` if the addr is out of bounds
  fn alloc_id_from_addr(ecx: &MiriInterpCx<'mir, 'tcx>, addr: u64) -> Option<AllocId> {

src/lib.rs

@@ -125,7 +125,7 @@ pub use crate::machine::{
 pub use crate::mono_hash_map::MonoHashMap;
 pub use crate::operator::EvalContextExt as _;
 pub use crate::range_map::RangeMap;
-pub use crate::tag_gc::{EvalContextExt as _, VisitTags};
+pub use crate::tag_gc::{EvalContextExt as _, TagVisitor, VisitTags};
 
 /// Insert rustc arguments at the beginning of the argument list that Miri wants to be
 /// set per default, for maximal validation power.

src/machine.rs

@@ -79,7 +79,7 @@ impl<'tcx> std::fmt::Debug for FrameExtra<'tcx> {
 }
 
 impl VisitTags for FrameExtra<'_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let FrameExtra { catch_unwind, borrow_tracker, timing: _, is_user_relevant: _ } = self;
 
  catch_unwind.visit_tags(visit);
@@ -295,7 +295,7 @@ pub struct AllocExtra<'tcx> {
 }
 
 impl VisitTags for AllocExtra<'_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let AllocExtra { borrow_tracker, data_race, weak_memory, backtrace: _ } = self;
 
  borrow_tracker.visit_tags(visit);
@@ -777,7 +777,7 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
 }
 
 impl VisitTags for MiriMachine<'_, '_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  #[rustfmt::skip]
  let MiriMachine {
  threads,

src/shims/env.rs

@@ -38,7 +38,7 @@ pub struct EnvVars<'tcx> {
 }
 
 impl VisitTags for EnvVars<'_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let EnvVars { map, environ } = self;
 
  environ.visit_tags(visit);

src/shims/panic.rs

@@ -36,7 +36,7 @@ pub struct CatchUnwindData<'tcx> {
 }
 
 impl VisitTags for CatchUnwindData<'_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let CatchUnwindData { catch_fn, data, dest, ret: _ } = self;
  catch_fn.visit_tags(visit);
  data.visit_tags(visit);

src/shims/time.rs

@@ -279,7 +279,7 @@ struct UnblockCallback {
 }
 
 impl VisitTags for UnblockCallback {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {}
+ fn visit_tags(&self, _visit: &mut TagVisitor<'_>) {}
 }
 
 impl<'mir, 'tcx: 'mir> MachineCallback<'mir, 'tcx> for UnblockCallback {

src/shims/tls.rs

@@ -208,7 +208,7 @@ impl<'tcx> TlsData<'tcx> {
 }
 
 impl VisitTags for TlsData<'_> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let TlsData { keys, macos_thread_dtors, next_key: _ } = self;
 
  for scalar in keys.values().flat_map(|v| v.data.values()) {

src/shims/unix/fs.rs

@@ -289,7 +289,7 @@ pub struct FileHandler {
 }
 
 impl VisitTags for FileHandler {
- fn visit_tags(&self, _visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, _visit: &mut TagVisitor<'_>) {
  // All our FileDescriptor do not have any tags.
  }
 }
@@ -491,7 +491,7 @@ impl Default for DirHandler {
 }
 
 impl VisitTags for DirHandler {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let DirHandler { streams, next_id: _ } = self;
 
  for dir in streams.values() {

src/shims/unix/linux/sync.rs

@@ -187,7 +187,7 @@ pub fn futex<'tcx>(
  }
 
  impl<'tcx> VisitTags for Callback<'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Callback { thread: _, addr_usize: _, dest } = self;
  dest.visit_tags(visit);
  }

src/shims/unix/sync.rs

@@ -817,7 +817,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
  }
 
  impl<'tcx> VisitTags for Callback<'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Callback { active_thread: _, mutex_id: _, id: _, dest } = self;
  dest.visit_tags(visit);
  }

src/shims/windows/sync.rs

@@ -205,7 +205,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
  }
 
  impl<'tcx> VisitTags for Callback<'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Callback { init_once_id: _, pending_place } = self;
  pending_place.visit_tags(visit);
  }
@@ -338,7 +338,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
  }
 
  impl<'tcx> VisitTags for Callback<'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Callback { thread: _, addr: _, dest } = self;
  dest.visit_tags(visit);
  }
@@ -442,7 +442,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
  }
 
  impl<'tcx> VisitTags for Callback<'tcx> {
- fn visit_tags(&self, visit: &mut dyn FnMut(BorTag)) {
+ fn visit_tags(&self, visit: &mut TagVisitor<'_>) {
  let Callback { thread: _, condvar_id: _, lock_id: _, mode: _, dest } = self;
  dest.visit_tags(visit);
  }