Imported Upstream version 1.9.0+dfsg1

[rustc.git] / src / librustc_mir / build / matches / simplify.rs

diff --git a/src/librustc_mir/build/matches/simplify.rs b/src/librustc_mir/build/matches/simplify.rs
index 2c8e1c1ccf673e9d44f5e7861552d6b86a0f2ca1..a3337badf884b92d9e0533052dc94fd4a5b98975 100644 (file)
--- a/src/librustc_mir/build/matches/simplify.rs
+++ b/src/librustc_mir/build/matches/simplify.rs
@@ -95,7 +95,18 @@ impl<'a,'tcx> Builder<'a,'tcx> {
                 Err(match_pair)
             }
 
-            PatternKind::Array { ref prefix, ref slice, ref suffix } => {
+            PatternKind::Range { .. } |
+            PatternKind::Variant { .. } => {
+                // cannot simplify, test is required
+                Err(match_pair)
+            }
+
+            PatternKind::Slice { .. } if !match_pair.slice_len_checked => {
+                Err(match_pair)
+            }
+
+            PatternKind::Array { ref prefix, ref slice, ref suffix } |
+            PatternKind::Slice { ref prefix, ref slice, ref suffix } => {
                 unpack!(block = self.prefix_suffix_slice(&mut candidate.match_pairs,
                                                          block,
                                                          match_pair.lvalue.clone(),
@@ -105,13 +116,6 @@ impl<'a,'tcx> Builder<'a,'tcx> {
                 Ok(block)
             }
 
-            PatternKind::Slice { .. } |
-            PatternKind::Range { .. } |
-            PatternKind::Variant { .. } => {
-                // cannot simplify, test is required
-                Err(match_pair)
-            }
-
             PatternKind::Leaf { ref subpatterns } => {
                 // tuple struct, match subpats (if any)
                 candidate.match_pairs