Ignore FakeReadCause::ForLet in liveness

ecstatic-morse · ecstatic-morse · commit 6a2987b3a08b · 2020-05-13T09:17:30.000-07:00
diff --git a/src/librustc_mir/dataflow/impls/liveness.rs b/src/librustc_mir/dataflow/impls/liveness.rs
@@ -49,6 +49,9 @@ impl GenKillAnalysis<'tcx> for MaybeLiveLocals {
         statement: &mir::Statement<'tcx>,
         location: Location,
     ) {
+        if let mir::StatementKind::FakeRead(mir::FakeReadCause::ForLet, _) = statement.kind {
+            return;
+        }
         self.transfer_function(trans).visit_statement(statement, location);
     }
 

Original file line number	Diff line number	Diff line change
`@@ -49,6 +49,9 @@ impl GenKillAnalysis<'tcx> for MaybeLiveLocals {`
`49`	`49`	`statement: &mir::Statement<'tcx>,`
`50`	`50`	`location: Location,`
`51`	`51`	`) {`
	`52`	`+ if let mir::StatementKind::FakeRead(mir::FakeReadCause::ForLet, _) = statement.kind {`
	`53`	`+ return;`
	`54`	`+ }`
`52`	`55`	`self.transfer_function(trans).visit_statement(statement, location);`
`53`	`56`	`}`
`54`	`57`