Add missing StorePointer/StoreSmi in ContextScope.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
===================================================================
--- runtime/vm/raw_object.h	(revision 41399)
+++ runtime/vm/raw_object.h	(working copy)
@@ -1211,13 +1211,21 @@
   int32_t num_variables_;
 
   RawObject** from() {
-    return reinterpret_cast<RawObject**>(&ptr()->data()[0]);
+    VariableDesc* begin = const_cast<VariableDesc*>(ptr()->VariableDescAddr(0));
+    return reinterpret_cast<RawObject**>(begin);
   }
   // Variable length data follows here.
-  RawObject** data() { OPEN_ARRAY_START(RawObject*, RawObject*); }
+  RawObject* const* data() const { OPEN_ARRAY_START(RawObject*, RawObject*); }
+  const VariableDesc* VariableDescAddr(intptr_t index) const {
+    ASSERT((index >= 0) && (index < num_variables_ + 1));
+    // data() points to the first component of the first descriptor.
+    return &(reinterpret_cast<const VariableDesc*>(data())[index]);
+  }
   RawObject** to(intptr_t num_vars) {
-    const intptr_t data_length = num_vars * (sizeof(VariableDesc)/kWordSize);
-    return reinterpret_cast<RawObject**>(&ptr()->data()[data_length - 1]);
+    VariableDesc* end =
+        const_cast<VariableDesc*>(ptr()->VariableDescAddr(num_vars));
+    // 'end' points at the first word beyond the last descriptor, so step back.
+    return reinterpret_cast<RawObject**>(end) - 1;

[Ivan Posva, 2014/11/07 00:18:12]

Pointer arithmetic?

   }
 };