VM support for running Kernel binaries.

runtime/vm/redundancy_elimination.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/redundancy_elimination.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph.h"
 #include "vm/hash_map.h"
 #include "vm/il_printer.h"
@@ skipping 3335 matching lines @@
 
     // Initialize cdefs with the original initial definitions (ParameterInstr).
     // The following representation is used:
     // ParameterInstr => unknown
     // ConstantInstr => known constant
     // NULL => non-constant
     GrowableArray<Definition*>* idefs = catch_entry->initial_definitions();
     GrowableArray<Definition*> cdefs(idefs->length());
     cdefs.AddArray(*idefs);
 
-    // exception_var and stacktrace_var are never constant.
-    intptr_t ex_idx = base - catch_entry->exception_var().index();
-    intptr_t st_idx = base - catch_entry->stacktrace_var().index();
-    cdefs[ex_idx] = cdefs[st_idx] = NULL;
+    // exception_var and stacktrace_var are never constant.  In asynchronous or
+    // generator functions they may be context-allocated in which case they are
+    // not tracked in the environment anyway.
+    if (!catch_entry->exception_var().is_captured()) {
+      cdefs[base - catch_entry->exception_var().index()] = NULL;
+    }
+    if (!catch_entry->stacktrace_var().is_captured()) {
+      cdefs[base - catch_entry->stacktrace_var().index()] = NULL;
+    }
 
     for (BlockIterator block_it = flow_graph->reverse_postorder_iterator();
          !block_it.Done();
          block_it.Advance()) {
       BlockEntryInstr* block = block_it.Current();
       if (block->try_index() == catch_entry->catch_try_index()) {
         for (ForwardInstructionIterator instr_it(block);
              !instr_it.Done();
              instr_it.Advance()) {
           Instruction* current = instr_it.Current();
@@ skipping 116 matching lines @@
         join->phis_ = NULL;
       } else {
         join->phis_->TruncateTo(to_index);
       }
     }
   }
 }
 
 
 }  // namespace dart