Validate well-formedness of the use lists in debug mode.

runtime/vm/flow_graph.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_FLOW_GRAPH_H_
 #define VM_FLOW_GRAPH_H_
 
 #include "vm/growable_array.h"
 #include "vm/parser.h"
 
@@ skipping 51 matching lines @@
 
   intptr_t alloc_ssa_temp_index() { return current_ssa_temp_index_++; }
 
   // Operations on the flow graph.
   void ComputeSSA();
   void ComputeUseLists();
 
   // TODO(zerny): Once the SSA is feature complete this should be removed.
   void Bailout(const char* reason) const;
 
+#ifdef DEBUG
+  // Validation methods for debugging.
+  bool ResetUseLists();
+  bool ValidateUseLists();
+#endif  // DEBUG
+
  private:
   void DiscoverBlocks();
 
   // SSA transformation methods and fields.
   void ComputeDominators(
       GrowableArray<BlockEntryInstr*>* preorder,
       GrowableArray<intptr_t>* parent,
       GrowableArray<BitVector*>* dominance_frontier);
 
   void CompressPath(
@@ skipping 31 matching lines @@
   const intptr_t stack_local_count_;
   GraphEntryInstr* graph_entry_;
   GrowableArray<BlockEntryInstr*> preorder_;
   GrowableArray<BlockEntryInstr*> postorder_;
   GrowableArray<BlockEntryInstr*> reverse_postorder_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_H_