Port MaybeStorageLive to new dataflow framework

Author: ecstatic-morse

src/librustc_mir/dataflow/impls/storage_liveness.rs

@@ -1,70 +1,68 @@
 pub use super::*;
 
-use crate::dataflow::generic::{Results, ResultsRefCursor};
-use crate::dataflow::BitDenotation;
-use crate::dataflow::MaybeBorrowedLocals;
+use crate::dataflow::generic::{self as dataflow, GenKill, Results, ResultsRefCursor};
+use crate::dataflow::BottomValue;
 use rustc::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor};
 use rustc::mir::*;
 use std::cell::RefCell;
 
 #[derive(Copy, Clone)]
-pub struct MaybeStorageLive<'a, 'tcx> {
-    body: &'a Body<'tcx>,
-}
+pub struct MaybeStorageLive;
 
-impl<'a, 'tcx> MaybeStorageLive<'a, 'tcx> {
-    pub fn new(body: &'a Body<'tcx>) -> Self {
-        MaybeStorageLive { body }
-    }
+impl dataflow::AnalysisDomain<'tcx> for MaybeStorageLive {
+    type Idx = Local;
 
-    pub fn body(&self) -> &Body<'tcx> {
-        self.body
-    }
-}
+    const NAME: &'static str = "maybe_storage_live";
 
-impl<'a, 'tcx> BitDenotation<'tcx> for MaybeStorageLive<'a, 'tcx> {
-    type Idx = Local;
-    fn name() -> &'static str {
-        "maybe_storage_live"
-    }
-    fn bits_per_block(&self) -> usize {
-        self.body.local_decls.len()
+    fn bits_per_block(&self, body: &mir::Body<'tcx>) -> usize {
+        body.local_decls.len()
     }
 
-    fn start_block_effect(&self, on_entry: &mut BitSet<Local>) {
+    fn initialize_start_block(&self, body: &mir::Body<'tcx>, on_entry: &mut BitSet<Self::Idx>) {
         // The resume argument is live on function entry (we don't care about
         // the `self` argument)
-        for arg in self.body.args_iter().skip(1) {
+        for arg in body.args_iter().skip(1) {
             on_entry.insert(arg);
         }
     }
+}
 
-    fn statement_effect(&self, trans: &mut GenKillSet<Local>, loc: Location) {
-        let stmt = &self.body[loc.block].statements[loc.statement_index];
-
+impl dataflow::GenKillAnalysis<'tcx> for MaybeStorageLive {
+    fn statement_effect(
+        &self,
+        trans: &mut impl GenKill<Self::Idx>,
+        stmt: &mir::Statement<'tcx>,
+        _: Location,
+    ) {
         match stmt.kind {
             StatementKind::StorageLive(l) => trans.gen(l),
             StatementKind::StorageDead(l) => trans.kill(l),
             _ => (),
         }
     }
 
-    fn terminator_effect(&self, _trans: &mut GenKillSet<Local>, _loc: Location) {
+    fn terminator_effect(
+        &self,
+        _trans: &mut impl GenKill<Self::Idx>,
+        _: &mir::Terminator<'tcx>,
+        _: Location,
+    ) {
         // Terminators have no effect
     }
 
-    fn propagate_call_return(
+    fn call_return_effect(
         &self,
-        _in_out: &mut BitSet<Local>,
-        _call_bb: mir::BasicBlock,
-        _dest_bb: mir::BasicBlock,
-        _dest_place: &mir::Place<'tcx>,
+        _trans: &mut impl GenKill<Self::Idx>,
+        _block: BasicBlock,
+        _func: &mir::Operand<'tcx>,
+        _args: &[mir::Operand<'tcx>],
+        _return_place: &mir::Place<'tcx>,
     ) {
         // Nothing to do when a call returns successfully
     }
 }
 
-impl<'a, 'tcx> BottomValue for MaybeStorageLive<'a, 'tcx> {
+impl BottomValue for MaybeStorageLive {
     /// bottom = dead
     const BOTTOM_VALUE: bool = false;
 }

src/librustc_mir/transform/generator.rs

@@ -473,12 +473,10 @@ fn locals_live_across_suspend_points(
 
     // Calculate when MIR locals have live storage. This gives us an upper bound of their
     // lifetimes.
-    let storage_live_analysis = MaybeStorageLive::new(body_ref);
-    let storage_live_results =
-        do_dataflow(tcx, body_ref, def_id, &[], &dead_unwinds, storage_live_analysis, |bd, p| {
-            DebugFormatted::new(&bd.body().local_decls[p])
-        });
-    let mut storage_live_cursor = DataflowResultsCursor::new(&storage_live_results, body_ref);
+    let mut storage_live = MaybeStorageLive
+        .into_engine(tcx, body_ref, def_id)
+        .iterate_to_fixpoint()
+        .into_results_cursor(body_ref);
 
     // Find the MIR locals which do not use StorageLive/StorageDead statements.
     // The storage of these locals are always live.
@@ -534,8 +532,8 @@ fn locals_live_across_suspend_points(
                 liveness.outs[block].union(borrowed_locals_cursor.get());
             }
 
-            storage_live_cursor.seek(loc);
-            let storage_liveness = storage_live_cursor.get();
+            storage_live.seek_before(loc);
+            let storage_liveness = storage_live.get();
 
             // Store the storage liveness for later use so we can restore the state
             // after a suspension point