add antlr

lib/antlr4/include/tree/TerminalNode.h

@@ -0,0 +1,32 @@
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+#include "tree/ParseTree.h"
+
+namespace antlr4 {
+namespace tree {
+
+  class ANTLR4CPP_PUBLIC TerminalNode : public ParseTree {
+  public:
+    ~TerminalNode() override;
+
+    virtual Token* getSymbol() = 0;
+
+    /** Set the parent for this leaf node.
+     *
+     *  Technically, this is not backward compatible as it changes
+     *  the interface but no one was able to create custom
+     *  TerminalNodes anyway so I'm adding as it improves internal
+     *  code quality.
+     *
+     *  @since 4.7
+     */
+    virtual void setParent(RuleContext *parent) = 0;
+  };
+
+} // namespace tree
+} // namespace antlr4