Zap holes in dependent code array after deoptimizing a code group.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index d9da23f363ed1e18e363ff3e79b0fe02d348cc29..4e5a434ddbe314b944b680fd681e6f1c88cf59b0 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9601,9 +9601,15 @@ void DependentCode::DeoptimizeDependentCodeGroup(
     Code* code = code_at(i);
     code->set_marked_for_deoptimization(true);
   }
+  // Compact the array by moving all subsequent groups to fill in the new holes.
   for (int src = end, dst = start; src < number_of_entries; src++, dst++) {
     set_code_at(dst, code_at(src));
   }
+  // Now the holes are at the end of the array, zap them.

[Michael Starzinger, 2013/02/25 12:18:22]

Maybe we should add a comment saying that this is only needed by the
heap-verifier, but we play it safe and always do it. I'll leave this up to you.

+  int removed = end - start;
+  for (int i = number_of_entries - removed; i < number_of_entries; i++) {
+    clear_code_at(i);
+  }
   set_number_of_entries(group, 0);
   DeoptimizeDependentCodeFilter filter;
   Deoptimizer::DeoptimizeAllFunctionsWith(&filter);