CompileType::ToNullableCid must check whether type is implemented in addition to checking whether t…

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 100 matching lines @@
 //      is guaranteed to be sub type of this type.
 //
 // Values of CompileType form a lattice with a None type as a bottom and a
 // nullable Dynamic type as a top element. Method Union provides a join
 // operation for the lattice.
 class CompileType : public ValueObject {
  public:
   static const bool kNullable = true;
   static const bool kNonNullable = false;
 
+  CompileType(bool is_nullable, intptr_t cid, const AbstractType* type)
+      : is_nullable_(is_nullable), cid_(cid), type_(type) { }
+
   CompileType(const CompileType& other)
       : ValueObject(),
         is_nullable_(other.is_nullable_),
         cid_(other.cid_),
         type_(other.type_) { }
 
   CompileType& operator=(const CompileType& other) {
     is_nullable_ = other.is_nullable_;
     cid_ = other.cid_;
     type_ =  other.type_;
@@ skipping 72 matching lines @@
   }
 
   bool IsNone() const {
     return (cid_ == kIllegalCid) && (type_ == NULL);
   }
 
   void PrintTo(BufferFormatter* f) const;
   const char* ToCString() const;
 
  private:
-  CompileType(bool is_nullable, intptr_t cid, const AbstractType* type)
-      : is_nullable_(is_nullable), cid_(cid), type_(type) { }
-
   bool CanComputeIsInstanceOf(const AbstractType& type,
                               bool is_nullable,
                               bool* is_instance);
 
   bool is_nullable_;
   intptr_t cid_;
   const AbstractType* type_;
 };
 
 
@@ skipping 4271 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_