CASTUnaryExpression.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.IASTExpression;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IASTUnaryExpression;
import org.eclipse.cdt.core.dom.ast.IArrayType;
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;
import org.eclipse.cdt.internal.core.dom.parser.ITypeContainer;

/**
 * Unary expression in C.
 */
public class CASTUnaryExpression extends ASTNode implements IASTUnaryExpression, IASTAmbiguityParent {
    private int operator;
    private IASTExpression operand;

    
    public CASTUnaryExpression() {
	}

	public CASTUnaryExpression(int operator, IASTExpression operand) {
		this.operator = operator;
		setOperand(operand);
	}

	public CASTUnaryExpression copy() {
		return copy(CopyStyle.withoutLocations);
	}
	
	public CASTUnaryExpression copy(CopyStyle style) {
		CASTUnaryExpression copy = new CASTUnaryExpression(operator, operand == null ? null
				: operand.copy(style));
		copy.setOffsetAndLength(this);
		if (style == CopyStyle.withLocations) {
			copy.setCopyLocation(this);
		}
		return copy;
	}

	public int getOperator() {
        return operator;
    }

    public void setOperator(int value) {
        assertNotFrozen();
        this.operator = value;
    }

    public IASTExpression getOperand() {
        return operand;
    }

    public void setOperand(IASTExpression expression) {
        assertNotFrozen();
        operand = expression;
        if (expression != null) {
			expression.setParent(this);
			expression.setPropertyInParent(OPERAND);
		}
    }

    @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( operand != null ) if( !operand.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 == operand )
        {
            other.setPropertyInParent( child.getPropertyInParent() );
            other.setParent( child.getParent() );
            operand = (IASTExpression) other;
        }
    }
    
	public IType getExpressionType() {
		int op = getOperator();
		if (op == op_sizeof) {
			return CVisitor.get_SIZE_T(this);
		}
		final IType exprType = getOperand().getExpressionType();
		IType type = CVisitor.unwrapTypedefs(exprType);
		switch(op) {
		case op_star:
			if (type instanceof IPointerType || type instanceof IArrayType) {
				return ((ITypeContainer) type).getType();
			}
			break;
		case op_amper:
			return new CPointerType(type, 0);
		case op_minus:
		case op_plus:
		case op_tilde:
			IType t= CArithmeticConversion.promoteCType(type);
			if (t != null) {
				return t;
			}
			break;
		}
		return exprType; // return the original
	}

	public boolean isLValue() {
		switch (getOperator()) {
		case op_bracketedPrimary:
			return getOperand().isLValue();
		case op_star:
		case op_prefixDecr:
		case op_prefixIncr:
			return true;
		default:
			return false;
		}
	}
	
	public final ValueCategory getValueCategory() {
		return isLValue() ? ValueCategory.LVALUE : ValueCategory.PRVALUE;
	}
}