TargetValue.java

/*
  TargetValue.java

  (c) 2010-2014 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.tools.forthcomp.words;

import v9t9.tools.forthcomp.AbortException;
import v9t9.tools.forthcomp.DictEntry;
import v9t9.tools.forthcomp.HostContext;
import v9t9.tools.forthcomp.ISemantics;
import v9t9.tools.forthcomp.ITargetContext;
import v9t9.tools.forthcomp.TargetContext;

/**
 * @author ejs
 *
 */
public class TargetValue extends TargetWord {
	private int cells;

	/**
	 * @param addr 
	 * 
	 */
	public TargetValue(DictEntry entry, int cells_) {
		super(entry);
		this.cells = cells_;
		
		setCompilationSemantics(new ISemantics() {
			
			public void execute(HostContext hostContext, TargetContext targetContext)
					throws AbortException {
				if (getEntry().canInline())
					targetContext.compileLiteral(getEntry().getParamAddr(), false, true);
				else
					targetContext.compile(TargetValue.this);
			}
		});
		setExecutionSemantics(new ISemantics() {
			
			public void execute(HostContext hostContext, TargetContext targetContext)
			throws AbortException {
				int addr = getEntry().getParamAddr();
				if (getCells() == 1)
					hostContext.pushData(targetContext.readCell(addr));
				else if (getCells() == 2) {
					hostContext.pushData(targetContext.readCell(addr + targetContext.getCellSize()));
					hostContext.pushData(targetContext.readCell(addr));
				} else
					assert false;
			}
		});
	}

	/**
	 * @param value
	 */
	public void setValue(ITargetContext targetContext, int value) {
		targetContext.writeCell(getEntry().getParamAddr(), value);
	}

	/**
	 * @return
	 */
	public int getCells() {
		return cells;
	}
	
}