add antlr

lib/antlr4/include/InterpreterRuleContext.h

@@ -0,0 +1,45 @@
+/* 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 "ParserRuleContext.h"
+
+namespace antlr4 {
+
+  /**
+   * This class extends {@link ParserRuleContext} by allowing the value of
+   * {@link #getRuleIndex} to be explicitly set for the context.
+   *
+   * <p>
+   * {@link ParserRuleContext} does not include field storage for the rule index
+   * since the context classes created by the code generator override the
+   * {@link #getRuleIndex} method to return the correct value for that context.
+   * Since the parser interpreter does not use the context classes generated for a
+   * parser, this class (with slightly more memory overhead per node) is used to
+   * provide equivalent functionality.</p>
+   */
+  class ANTLR4CPP_PUBLIC InterpreterRuleContext : public ParserRuleContext {
+  public:
+    InterpreterRuleContext();
+
+    /**
+     * Constructs a new {@link InterpreterRuleContext} with the specified
+     * parent, invoking state, and rule index.
+     *
+     * @param parent The parent context.
+     * @param invokingStateNumber The invoking state number.
+     * @param ruleIndex The rule index for the current context.
+     */
+    InterpreterRuleContext(ParserRuleContext *parent, size_t invokingStateNumber, size_t ruleIndex);
+
+    virtual size_t getRuleIndex() const override;
+
+  protected:
+    /** This is the backing field for {@link #getRuleIndex}. */
+    const size_t _ruleIndex = INVALID_INDEX;
+};
+
+} // namespace antlr4