diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_propagate.rs')
-rw-r--r-- | compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_propagate.rs | 92 |
1 files changed, 0 insertions, 92 deletions
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_propagate.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_propagate.rs deleted file mode 100644 index 633b47889..000000000 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_propagate.rs +++ /dev/null @@ -1,92 +0,0 @@ -use super::{DropRangesBuilder, PostOrderId}; -use rustc_index::{bit_set::BitSet, IndexVec}; -use std::collections::BTreeMap; - -impl DropRangesBuilder { - pub fn propagate_to_fixpoint(&mut self) { - trace!("before fixpoint: {:#?}", self); - let preds = self.compute_predecessors(); - - trace!("predecessors: {:#?}", preds.iter_enumerated().collect::<BTreeMap<_, _>>()); - - let mut new_state = BitSet::new_empty(self.num_values()); - let mut changed_nodes = BitSet::new_empty(self.nodes.len()); - let mut unchanged_mask = BitSet::new_filled(self.nodes.len()); - changed_nodes.insert(0u32.into()); - - let mut propagate = || { - let mut changed = false; - unchanged_mask.insert_all(); - for id in self.nodes.indices() { - trace!("processing {:?}, changed_nodes: {:?}", id, changed_nodes); - // Check if any predecessor has changed, and if not then short-circuit. - // - // We handle the start node specially, since it doesn't have any predecessors, - // but we need to start somewhere. - if match id.index() { - 0 => !changed_nodes.contains(id), - _ => !preds[id].iter().any(|pred| changed_nodes.contains(*pred)), - } { - trace!("short-circuiting because none of {:?} have changed", preds[id]); - unchanged_mask.remove(id); - continue; - } - - if id.index() == 0 { - new_state.clear(); - } else { - // If we are not the start node and we have no predecessors, treat - // everything as dropped because there's no way to get here anyway. - new_state.insert_all(); - }; - - for pred in &preds[id] { - new_state.intersect(&self.nodes[*pred].drop_state); - } - - for drop in &self.nodes[id].drops { - new_state.insert(*drop); - } - - for reinit in &self.nodes[id].reinits { - new_state.remove(*reinit); - } - - if self.nodes[id].drop_state.intersect(&new_state) { - changed_nodes.insert(id); - changed = true; - } else { - unchanged_mask.remove(id); - } - } - - changed_nodes.intersect(&unchanged_mask); - changed - }; - - while propagate() { - trace!("drop_state changed, re-running propagation"); - } - - trace!("after fixpoint: {:#?}", self); - } - - fn compute_predecessors(&self) -> IndexVec<PostOrderId, Vec<PostOrderId>> { - let mut preds = IndexVec::from_fn_n(|_| vec![], self.nodes.len()); - for (id, node) in self.nodes.iter_enumerated() { - // If the node has no explicit successors, we assume that control - // will from this node into the next one. - // - // If there are successors listed, then we assume that all - // possible successors are given and we do not include the default. - if node.successors.len() == 0 && id.index() != self.nodes.len() - 1 { - preds[id + 1].push(id); - } else { - for succ in &node.successors { - preds[*succ].push(id); - } - } - } - preds - } -} |