Refactored SEA IR folder structure to be more logical.

Change-Id: I302c79af92c07cceb38dff36efe416bfa4869a91
diff --git a/compiler/sea_ir/ir/sea_node.h b/compiler/sea_ir/ir/sea_node.h
new file mode 100644
index 0000000..4dab5cb
--- /dev/null
+++ b/compiler/sea_ir/ir/sea_node.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_SEA_IR_IR_SEA_NODE_H_
+#define ART_COMPILER_SEA_IR_IR_SEA_NODE_H_
+
+#include "base/stringprintf.h"
+
+namespace sea_ir {
+class Region;
+class IRVisitor;
+
+class IVisitable {
+ public:
+  virtual void Accept(IRVisitor* visitor) = 0;
+  virtual ~IVisitable() {}
+};
+
+// This abstract class provides the essential services that
+// we want each SEA IR element to have.
+// At the moment, these are:
+// - an id and corresponding string representation.
+// - a .dot graph language representation for .dot output.
+//
+// Note that SEA IR nodes could also be Regions, Projects
+// which are not instructions.
+class SeaNode: public IVisitable {
+ public:
+  explicit SeaNode():id_(GetNewId()), string_id_() {
+    string_id_ = art::StringPrintf("%d", id_);
+  }
+
+  // Adds CFG predecessors and successors to each block.
+  void AddSuccessor(Region* successor);
+  void AddPredecessor(Region* predecesor);
+
+  // Returns the id of the current block as string
+  const std::string& StringId() const {
+    return string_id_;
+  }
+  // Returns the id of this node as int. The id is supposed to be unique among
+  // all instances of all subclasses of this class.
+  int Id() const {
+    return id_;
+  }
+
+  virtual ~SeaNode() { }
+
+ protected:
+  static int GetNewId() {
+    return current_max_node_id_++;
+  }
+
+  const int id_;
+  std::string string_id_;
+
+ private:
+  static int current_max_node_id_;
+  // Creating new instances of sea node objects should not be done through copy or assignment
+  // operators because that would lead to duplication of their unique ids.
+  DISALLOW_COPY_AND_ASSIGN(SeaNode);
+};
+}  // namespace sea_ir
+#endif  // ART_COMPILER_SEA_IR_IR_SEA_NODE_H_