OriginNode.java

/**
 * Copyright 2012 Tobias Gierke <tobias.gierke@code-sourcery.de>
 *
 * 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.
 */
package de.codesourcery.jasm16.ast;

import java.io.IOException;

import de.codesourcery.jasm16.Address;
import de.codesourcery.jasm16.compiler.ICompilationContext;
import de.codesourcery.jasm16.compiler.io.IObjectCodeWriter;
import de.codesourcery.jasm16.exceptions.ParseException;
import de.codesourcery.jasm16.lexer.TokenType;
import de.codesourcery.jasm16.parser.IParseContext;

/**
 * '.org' AST node.
 * 
 * @author tobias.gierke@code-sourcery.de
 */
public class OriginNode extends ObjectCodeOutputNode implements IPreprocessorDirective
{
    @Override
	protected ASTNode copySingleNode()
    {
        final OriginNode result = new OriginNode();
        result.setAddress( getAddress() );
        return result;
    }

    @Override
    public boolean supportsChildNodes()
    {
        return true;
    }

    @Override
    protected ASTNode parseInternal(IParseContext context) throws ParseException
    {
        mergeWithAllTokensTextRegion( context.read( TokenType.ORIGIN ) );
        mergeWithAllTokensTextRegion( context.parseWhitespace() );
        
        final NumberNode number;
        try {
            context.mark();
            number = (NumberNode) addChild( new NumberNode().parseInternal( context ) , context );
        } catch(Exception e) {
            addCompilationErrorAndAdvanceParser( e , context );
            return this;
        } finally {
            context.clearMark();
        }
        
        try {
            setAddress( Address.wordAddress( number.getValue() ) );
        } catch(IllegalArgumentException e) {
            context.addCompilationError( "Address value is out-of-range" , number );            
        }
        return this;
    }

	@Override
    public void symbolsResolved(ICompilationContext context)
    {
        // nothing to do here
    }

    @Override
    public int getSizeInBytes(long thisNodesObjectCodeOffsetInBytes)
    {
    	if ( getAddress().getValue() < thisNodesObjectCodeOffsetInBytes ) {
    		return UNKNOWN_SIZE;
    	} else  if ( getAddress().getValue() == thisNodesObjectCodeOffsetInBytes ) {
    		return 0;
    	}
        return (int) (getAddress().getValue() - thisNodesObjectCodeOffsetInBytes);
    }

    @Override
    public void writeObjectCode(IObjectCodeWriter writer, ICompilationContext compContext) throws IOException, ParseException
    {
        if ( getAddress() == null ) {
            throw new RuntimeException("Internal error, .origin node has no address ?");
        }
        
        writer.advanceToWriteOffset( getAddress() );
    }
}