Fix #3969: AddMissingInts: Rescue bbs shd. receive state from pred.in

* This (conservatively) ensures that even if the very first instruction of the BB might raise an exception, the rescue block sees state from entry of the BB, rather than (optimistically) from the end of the BB which control might never reach. * The conservative assumption also matches the JVM verifier's assumption and should ensure that generated bytecode passes the verifier * Verified that the generated IR is correct on the following snippet. -------- def foo saved = bar() ensure bar(saved) end --------
jruby · Jun 15, 2016 · f3f5776 · f3f5776
1 parent fd4c8d3
commit f3f5776
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java b/core/src/main/java/org/jruby/ir/dataflow/analyses/DefinedVariableNode.java
@@ -43,18 +43,20 @@ public void applyPreMeetHandler() {
 
     @Override
     public void compute_MEET(Edge e, DefinedVariableNode pred) {
+        BitSet predState =  basicBlock.isRescueEntry() ? pred.in : pred.out;
+
         // If pred.out is TOP, in doesn't change.
-        if (pred.out != null) {
+        if (predState != null) {
             // if in is TOP, init in to a bitset with all 1's
             // so the intersection computes the right value.
             if (in == null) {
                 // Make sure 'in' and 'out' are the same size!
-                int n = pred.out.size();
+                int n = predState.size();
                 in = new BitSet(n);
                 in.set(0, n);
             }
 
-            in.and(pred.out);
+            in.and(predState);
         }
     }