From fe0260fbf892d5b49e79ee310b5e198c72c3d576 Mon Sep 17 00:00:00 2001
From: Federico Poli <federpoli@gmail.com>
Date: Thu, 15 Feb 2018 15:04:43 +0100
Subject: [PATCH] mir: Gather move at SwitchInt, Assert terminators

Previously, "_1" was not marked as "definitely uninitialized" after a "switchInt(move _1)" terminator.

Related discussion: https://internals.rust-lang.org/t/why-is-2-definitely-initialized-after-switchint-move-2/6760
---
 src/librustc_mir/dataflow/move_paths/builder.rs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/librustc_mir/dataflow/move_paths/builder.rs b/src/librustc_mir/dataflow/move_paths/builder.rs
index 635d99e7737a9..d6f419f6cfb41 100644
--- a/src/librustc_mir/dataflow/move_paths/builder.rs
+++ b/src/librustc_mir/dataflow/move_paths/builder.rs
@@ -353,9 +353,12 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> {
                 self.gather_move(&Place::Local(RETURN_PLACE));
             }
 
-            TerminatorKind::Assert { .. } |
-            TerminatorKind::SwitchInt { .. } => {
-                // branching terminators - these don't move anything
+            TerminatorKind::Assert { ref cond, .. } => {
+                self.gather_operand(cond);
+            }
+
+            TerminatorKind::SwitchInt { ref discr, .. } => {
+                self.gather_operand(discr);
             }
 
             TerminatorKind::Yield { ref value, .. } => {