OoasTools

/**

  *

  *                      OOAS Compiler

  *

  *       Copyright 2015, AIT Austrian Institute of Technology.

  * This code is based on the C# Version of the OOAS Compiler, which is

  * copyright 2015 by the Institute of Software Technology, Graz University

  * of Technology with portions copyright by the AIT Austrian Institute of

  * Technology. All rights reserved.

  *

  * SEE THE "LICENSE" FILE FOR THE TERMS UNDER WHICH THIS FILE IS PROVIDED.

  *

  * If you modify the file please update the list of contributors below to in-

  * clude your name. Please also stick to the coding convention of using TABs

  * to do the basic (block-level) indentation and spaces for anything after

  * that. (Enable the display of special chars and it should be pretty obvious

  * what this means.) Also, remove all trailing whitespace.

  *

  * Contributors:

  *               Willibald Krenn (AIT)

  *               Stephan Zimmerer (AIT)

  *               Markus Demetz (AIT)

  *               Christoph Czurda (AIT)

  *

  */

package org.momut.ooas.visitors;

import java.util.Stack;

/// <summary>

/// This visitor scans all methods and decides whether they are pure, i.e. there is no state-update.

/// </summary>

public final class OoaMethodPureClassifierVisitor extends OoaCompleteAstTraversalVisitor

{

	Stack<MethodIdentifier> currentMethod = new Stack<MethodIdentifier>();

	@Override

	public void visit(MethodIdentifier methodIdentifier)

	{

		currentMethod.push(methodIdentifier);

		((FunctionType)currentMethod.peek().type()).SetIsPureFunction(true); // assume is true..

		super.visit(currentMethod.peek());

		if (((FunctionType)currentMethod.peek().type()).isPureFunction())

		{

			m_ParserState.AddMessage(

					new ParserMessage(m_ParserState.filename, methodIdentifier.line(),

							methodIdentifier.column(), String.format("Found pure method: %s",

									methodIdentifier.tokenText())));

		} else

			m_ParserState.AddMessage(

					new ParserMessage(m_ParserState.filename, methodIdentifier.line(),

							methodIdentifier.column(), String.format("Found extended method: %s",

									methodIdentifier.tokenText())));

		currentMethod.pop();

	}

	@Override

	public void visit(OoActionSystemType systemType)

	{

		boolean functionPure = false; //introduce variable with save value

		if (currentMethod.size() > 0 && currentMethod.peek() != null) //if we are determining the pureness...

		{

			functionPure = ((FunctionType)currentMethod.peek().type()).isPureFunction(); //...save the current value

		}

		super.visit(systemType); // go down in recursion

		if ( currentMethod.size() > 0 && currentMethod.peek() != null) //but restore old pureness!

		{

			((FunctionType)currentMethod.peek().type()).SetIsPureFunction(functionPure);

		}

	}

	@Override

	public void visit(Assignment assignment)

	{

		boolean assignmentPure = true;

		if (currentMethod.size() > 0 && currentMethod.peek() != null)

		{

			for (Expression x: assignment.places())

			{

				if (x.kind() != ExpressionKind.Identifier)

					assignmentPure = false;

				else if (((IdentifierExpression)x).identifier().kind() == IdentifierKind.AttributeIdentifier)

					assignmentPure = false;

			}

			boolean functionPure = assignmentPure && ((FunctionType)currentMethod.peek().type()).isPureFunction();

			((FunctionType)currentMethod.peek().type()).SetIsPureFunction(functionPure);

		}

		super.visit(assignment);

	}

	public OoaMethodPureClassifierVisitor(ParserState aState)

	{

		super (aState);

	}

}