Fix uninitialized variable errors when the appropriate sync occurs

compiler/rustc_borrowck/src/polonius/loan_invalidations.rs

@@ -145,11 +145,11 @@ impl<'cx, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'cx, 'tcx> {
  self.mutate_place(location, *resume_arg, Deep);
  }
  TerminatorKind::Reattach { continuation } => {
- // FIXME(jhilton): Should we be invalidating locals in the current basic block as well? I think we should be,
+ // FIXME(jhilton): Should we be invalidating locals in the current basic block as well? I think we should be,
  // for consistency with what we did in the type-checker. My concern is that we only want to kill locals for the
  // *current block*, which I don't think we're currently expressing. One way to think about modeling this
  // is that we can imagine Detach as pushing a new stack frame for the spawned task so that way we don't
- // invalidate all locals, only the locals that are generated in the spawned task. Alternatively, loan invalidation
+ // invalidate all locals, only the locals that are generated in the spawned task. Alternatively, loan invalidation
  // can be handled by however blocks handle this situation.
  let borrow_set = self.borrow_set;
  let end_spawned_task =

compiler/rustc_data_structures/src/work_queue.rs

@@ -42,3 +42,11 @@ impl<T: Idx> WorkQueue<T> {
  }
  }
 }
+
+impl<T: Idx> Extend<T> for WorkQueue<T> {
+ fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
+ for element in iter {
+ self.insert(element);
+ }
+ }
+}

compiler/rustc_index/src/bit_set.rs

@@ -677,8 +677,63 @@ impl<T: Idx> BitRelations<ChunkedBitSet<T>> for ChunkedBitSet<T> {
  unimplemented!("implement if/when necessary");
  }
 
- fn intersect(&mut self, _other: &ChunkedBitSet<T>) -> bool {
- unimplemented!("implement if/when necessary");
+ fn intersect(&mut self, other: &ChunkedBitSet<T>) -> bool {
+ assert_eq!(self.domain_size, other.domain_size);
+ debug_assert_eq!(self.chunks.len(), other.chunks.len());
+
+ let mut changed = false;
+ for (mut self_chunk, other_chunk) in self.chunks.iter_mut().zip(other.chunks.iter()) {
+ match (&mut self_chunk, &other_chunk) {
+ (_, Ones(_)) | (Zeros(_), _) => {}
+ (Ones(self_chunk_domain_size), Zeros(other_chunk_domain_size))
+ | (Ones(self_chunk_domain_size), Mixed(other_chunk_domain_size, ..))
+ | (Mixed(self_chunk_domain_size, ..), Zeros(other_chunk_domain_size, ..)) => {
+ // `other_chunk` fully overwrites `self_chunk`
+ debug_assert_eq!(self_chunk_domain_size, other_chunk_domain_size);
+ *self_chunk = other_chunk.clone();
+ changed = true;
+ }
+ (
+ Mixed(
+ self_chunk_domain_size,
+ ref mut self_chunk_count,
+ ref mut self_chunk_words,
+ ),
+ Mixed(other_chunk_domain_size, _other_chunk_count, other_chunk_words),
+ ) => {
+ debug_assert_eq!(self_chunk_domain_size, other_chunk_domain_size);
+ // First check if the operation would change
+ // `self_chunk.words`. If not, we can avoid allocating some
+ // words, and this happens often enough that it's a
+ // performance win. Also, we only need to operate on the
+ // in-use words, hence the slicing.
+ let op = |a, b| a & b;
+ let num_words = num_words(*self_chunk_domain_size as usize);
+ if bitwise_changes(
+ &self_chunk_words[0..num_words],
+ &other_chunk_words[0..num_words],
+ op,
+ ) {
+ let self_chunk_words = Rc::make_mut(self_chunk_words);
+ let has_changed = bitwise(
+ &mut self_chunk_words[0..num_words],
+ &other_chunk_words[0..num_words],
+ op,
+ );
+ debug_assert!(has_changed);
+ *self_chunk_count = self_chunk_words[0..num_words]
+ .iter()
+ .map(|w| w.count_ones() as ChunkSize)
+ .sum();
+ if *self_chunk_count == *self_chunk_domain_size {
+ *self_chunk = Ones(*self_chunk_domain_size);
+ }
+ changed = true;
+ }
+ }
+ }
+ }
+ changed
  }
 }
 

compiler/rustc_index/src/bit_set/tests.rs

@@ -437,6 +437,92 @@ fn chunked_bitset_iter() {
  check_iter(&bit, &vec);
 }
 
+#[test]
+fn chunked_bitset_intersect_empty_empty() {
+ let vec: Vec<usize> = Vec::new();
+ let n = 10000;
+ let mut bit1 = with_elements_chunked(&vec, n);
+ let mut bit2 = with_elements_chunked(&vec, n);
+ assert!(!bit1.intersect(&bit2));
+ assert_eq!(bit1, bit2);
+ assert!(!bit2.intersect(&bit1));
+ assert_eq!(bit1, bit2);
+}
+
+#[test]
+fn chunked_bitset_intersect_empty_filled() {
+ let n = 10000;
+ let vec1: Vec<usize> = Vec::new();
+ let vec2: Vec<usize> = (0..n).collect();
+ let mut bit1 = with_elements_chunked(&vec1, n);
+ let mut bit2 = with_elements_chunked(&vec2, n);
+ let bit1_clone = bit1.clone();
+ assert!(!bit1.intersect(&bit2));
+ assert_eq!(bit1, bit1_clone);
+ assert!(bit2.intersect(&bit1));
+ assert_eq!(bit2, bit1);
+}
+
+#[test]
+fn chunked_bitset_intersect_empty_mixed() {
+ let n = 10000;
+ let vec1: Vec<usize> = Vec::new();
+ let vec2: Vec<usize> = vec![0, 1, 2, 2010, 2047, 2099, 6000, 6002, 6004];
+ let mut bit1 = with_elements_chunked(&vec1, n);
+ let mut bit2 = with_elements_chunked(&vec2, n);
+ let bit1_clone = bit1.clone();
+ assert!(!bit1.intersect(&bit2));
+ assert_eq!(bit1, bit1_clone);
+ assert!(bit2.intersect(&bit1));
+ assert_eq!(bit2, bit1);
+}
+
+#[test]
+fn chunked_bitset_intersect_filled_filled() {
+ let n = 10000;
+ let vec1: Vec<usize> = (0..n).collect();
+ let vec2: Vec<usize> = (0..n).collect();
+ let mut bit1 = with_elements_chunked(&vec1, n);
+ let mut bit2 = with_elements_chunked(&vec2, n);
+ let bit1_clone = bit1.clone();
+ assert!(!bit1.intersect(&bit2));
+ assert_eq!(bit1, bit1_clone);
+ assert!(!bit2.intersect(&bit1));
+ assert_eq!(bit2, bit1);
+}
+
+#[test]
+fn chunked_bitset_intersect_filled_mixed() {
+ let n = 10000;
+ let vec1: Vec<usize> = (0..n).collect();
+ let vec2: Vec<usize> = vec![0, 1, 2, 2010, 2047, 2099, 6000, 6002, 6004];
+ let vec_expected: Vec<usize> = vec![0, 1, 2, 2010, 2047, 2099, 6000, 6002, 6004];
+ let mut bit1 = with_elements_chunked(&vec1, n);
+ let mut bit2 = with_elements_chunked(&vec2, n);
+ let bit_expected = with_elements_chunked(&vec_expected, n);
+ let bit1_clone = bit1.clone();
+ assert!(bit1.intersect(&bit2));
+ assert_eq!(bit1, bit_expected);
+ assert!(!bit2.intersect(&bit1_clone));
+ assert_eq!(bit2, bit_expected);
+}
+
+#[test]
+fn chunked_bitset_intersect_mixed_mixed() {
+ let n = 10000;
+ let vec1: Vec<usize> = vec![0, 1, 2, 2010, 5, 10, 20];
+ let vec2: Vec<usize> = vec![0, 1, 2, 2010, 2047, 2099, 6000, 6002, 6004];
+ let vec_expected: Vec<usize> = vec![0, 1, 2, 2010];
+ let mut bit1 = with_elements_chunked(&vec1, n);
+ let mut bit2 = with_elements_chunked(&vec2, n);
+ let expected = with_elements_chunked(&vec_expected, n);
+ let bit1_clone = bit1.clone();
+ assert!(bit1.intersect(&bit2));
+ assert_eq!(bit1, expected);
+ assert!(bit2.intersect(&bit1_clone));
+ assert_eq!(bit2, expected);
+}
+
 #[test]
 fn grow() {
  let mut set: GrowableBitSet<usize> = GrowableBitSet::with_capacity(65);

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -553,6 +553,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
  }
  }
 
+ fn should_inject_fake_read(&self, initializer_id: ExprId) -> bool {
+ // For spawns, we don't want to emit a FakeRead since the value will only be defined on sync.
+ // They're nested inside a Scope consistently, so we just unwrap the scope.
+ match self.thir[initializer_id] {
+ Expr { kind: ExprKind::Scope { value, .. }, .. } => {
+ !matches!(self.thir[value], Expr { kind: ExprKind::CilkSpawn { .. }, .. })
+ }
+ _ => true,
+ }
+ }
+
  pub(super) fn expr_into_pattern(
  &mut self,
  mut block: BasicBlock,
@@ -566,9 +577,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
  self.storage_live_binding(block, var, irrefutable_pat.span, OutsideGuard, true);
  unpack!(block = self.expr_into_dest(place, block, initializer_id));
 
- // Inject a fake read, see comments on `FakeReadCause::ForLet`.
- let source_info = self.source_info(irrefutable_pat.span);
- self.cfg.push_fake_read(block, source_info, FakeReadCause::ForLet(None), place);
+ if self.should_inject_fake_read(initializer_id) {
+ // Inject a fake read, see comments on `FakeReadCause::ForLet`.
+ let source_info = self.source_info(irrefutable_pat.span);
+ self.cfg.push_fake_read(block, source_info, FakeReadCause::ForLet(None), place);
+ }
 
  self.schedule_drop_for_binding(var, irrefutable_pat.span, OutsideGuard);
  block.unit()
@@ -597,10 +610,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
  self.storage_live_binding(block, var, irrefutable_pat.span, OutsideGuard, true);
  unpack!(block = self.expr_into_dest(place, block, initializer_id));
 
- // Inject a fake read, see comments on `FakeReadCause::ForLet`.
- let pattern_source_info = self.source_info(irrefutable_pat.span);
- let cause_let = FakeReadCause::ForLet(None);
- self.cfg.push_fake_read(block, pattern_source_info, cause_let, place);
+ if self.should_inject_fake_read(initializer_id) {
+ // Inject a fake read, see comments on `FakeReadCause::ForLet`.
+ let pattern_source_info = self.source_info(irrefutable_pat.span);
+ let cause_let = FakeReadCause::ForLet(None);
+ self.cfg.push_fake_read(block, pattern_source_info, cause_let, place);
+ }
 
  let ty_source_info = self.source_info(annotation.span);