CASTConditionalExpression.java

/*******************************************************************************
 * Copyright (c) 2005, 2011 IBM Corporation and others.
 * 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
 *
 * Contributors:
 *    John Camelon (IBM Rational Software) - Initial API and implementation
 *    Yuan Zhang / Beth Tibbitts (IBM Research)
 *    Markus Schorn (Wind River Systems)
 *******************************************************************************/
package org.eclipse.cdt.internal.core.dom.parser.c;

import org.eclipse.cdt.core.dom.ast.ASTVisitor;
import org.eclipse.cdt.core.dom.ast.IASTConditionalExpression;
import org.eclipse.cdt.core.dom.ast.IASTExpression;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IPointerType;
import org.eclipse.cdt.core.dom.ast.IType;
import org.eclipse.cdt.internal.core.dom.parser.ASTNode;
import org.eclipse.cdt.internal.core.dom.parser.IASTAmbiguityParent;

/**
 * Conditional expression in C
 */
public class CASTConditionalExpression extends ASTNode implements
        IASTConditionalExpression, IASTAmbiguityParent {

    private IASTExpression condition;
    private IASTExpression negative;
    private IASTExpression positive;

    public CASTConditionalExpression() {
	}

	public CASTConditionalExpression(IASTExpression condition, 
			IASTExpression positive, IASTExpression negative) {
		setLogicalConditionExpression(condition);
		setPositiveResultExpression(positive);
		setNegativeResultExpression(negative);
	}
	
	public CASTConditionalExpression copy() {
		return copy(CopyStyle.withoutLocations);
	}

	public CASTConditionalExpression copy(CopyStyle style) {
		CASTConditionalExpression copy = new CASTConditionalExpression();
		copy.setLogicalConditionExpression(condition == null ? null : condition.copy(style));
		copy.setPositiveResultExpression(positive == null ? null : positive.copy(style));
		copy.setNegativeResultExpression(negative == null ? null : negative.copy(style));
		copy.setOffsetAndLength(this);
		if (style == CopyStyle.withLocations) {
			copy.setCopyLocation(this);
		}
		return copy;
	}

	public IASTExpression getLogicalConditionExpression() {
        return condition;
    }

    public void setLogicalConditionExpression(IASTExpression expression) {
        assertNotFrozen();
        condition = expression;
        if (expression != null) {
			expression.setParent(this);
			expression.setPropertyInParent(LOGICAL_CONDITION);
		}
    }

    public IASTExpression getPositiveResultExpression() {
        return positive;
    }

    public void setPositiveResultExpression(IASTExpression expression) {
        assertNotFrozen();
        this.positive = expression;
        if (expression != null) {
			expression.setParent(this);
			expression.setPropertyInParent(POSITIVE_RESULT);
		}
    }

    public IASTExpression getNegativeResultExpression() {
        return negative;
    }

    public void setNegativeResultExpression(IASTExpression expression) {
        assertNotFrozen();
        this.negative = expression;
        if (expression != null) {
			expression.setParent(this);
			expression.setPropertyInParent(NEGATIVE_RESULT);
		}
    }

    @Override
	public boolean accept( ASTVisitor action ){
        if( action.shouldVisitExpressions ){
		    switch( action.visit( this ) ){
	            case ASTVisitor.PROCESS_ABORT : return false;
	            case ASTVisitor.PROCESS_SKIP  : return true;
	            default : break;
	        }
		}
        
        if( condition != null ) if( !condition.accept( action ) ) return false;
        if( positive != null ) if( !positive.accept( action ) ) return false;
        if( negative != null ) if( !negative.accept( action ) ) return false;
        if( action.shouldVisitExpressions ){
        	switch( action.leave( this ) ){
        		case ASTVisitor.PROCESS_ABORT : return false;
        		case ASTVisitor.PROCESS_SKIP  : return true;
        		default : break;
        	}
        }
        return true;
    }
    
    public void replace(IASTNode child, IASTNode other) {
        if( child == condition )
        {
            other.setPropertyInParent( child.getPropertyInParent() );
            other.setParent( child.getParent() );
            condition = (IASTExpression) other;
        }
        if( child == positive)
        {
            other.setPropertyInParent( child.getPropertyInParent() );
            other.setParent( child.getParent() );
            positive= (IASTExpression) other;
        }
        if( child == negative)
        {
            other.setPropertyInParent( child.getPropertyInParent() );
            other.setParent( child.getParent() );
            negative= (IASTExpression) other;
        }
    }
    
    public IType getExpressionType() {
		IASTExpression positiveExpression = getPositiveResultExpression();
		if (positiveExpression == null) {
			positiveExpression= getLogicalConditionExpression();
		}
		IType t2 = positiveExpression.getExpressionType();
		IType t3 = getNegativeResultExpression().getExpressionType();
		if (t3 instanceof IPointerType || t2 == null)
			return t3;
		return t2;
	}
    
	public boolean isLValue() {
		return false;
	}
	
	public final ValueCategory getValueCategory() {
		return ValueCategory.PRVALUE;
	}
}