path: root/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTConditionalExpression.java

/*******************************************************************************
 *  Copyright (c) 2004, 2012 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) - Initial API and implementation
 *      Markus Schorn (Wind River Systems)
 *******************************************************************************/
package org.eclipse.cdt.internal.core.dom.parser.cpp;

import static org.eclipse.cdt.core.dom.ast.IASTExpression.ValueCategory.LVALUE;

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.IASTUnaryExpression;
import org.eclipse.cdt.core.dom.ast.IType;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTExpression;
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.cpp.semantics.EvalConditional;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalFixed;

public class CPPASTConditionalExpression extends ASTNode implements IASTConditionalExpression,
		ICPPASTExpression, IASTAmbiguityParent {
    private ICPPASTExpression fCondition;
    private ICPPASTExpression fPositive;
    private ICPPASTExpression fNegative;
    private ICPPEvaluation fEval;
    
    public CPPASTConditionalExpression() {
	}
    
	public CPPASTConditionalExpression(IASTExpression condition, IASTExpression postive, IASTExpression negative) {
    	setLogicalConditionExpression(condition);
    	setPositiveResultExpression(postive);
    	setNegativeResultExpression(negative);
	}

	@Override
	public CPPASTConditionalExpression copy() {
		return copy(CopyStyle.withoutLocations);
	}
	
	@Override
	public CPPASTConditionalExpression copy(CopyStyle style) {
		CPPASTConditionalExpression copy = new CPPASTConditionalExpression();
		copy.setLogicalConditionExpression(fCondition == null ? null : fCondition.copy(style));
		copy.setPositiveResultExpression(fPositive == null ? null : fPositive.copy(style));
		copy.setNegativeResultExpression(fNegative == null ? null : fNegative.copy(style));
		copy.setOffsetAndLength(this);
		if (style == CopyStyle.withLocations) {
			copy.setCopyLocation(this);
		}
		return copy;
	}

	@Override
	public IASTExpression getLogicalConditionExpression() {
        return fCondition;
    }

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

    @Override
	public IASTExpression getPositiveResultExpression() {
        return fPositive;
    }

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

    @Override
	public IASTExpression getNegativeResultExpression() {
        return fNegative;
    }

    @Override
	public void setNegativeResultExpression(IASTExpression expression) {
        assertNotFrozen();
        this.fNegative = (ICPPASTExpression) 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 (fCondition != null && !fCondition.accept(action))
			return false;
		if (fPositive != null && !fPositive.accept(action))
			return false;
		if (fNegative != null && !fNegative.accept(action))
			return false;
        
		if (action.shouldVisitExpressions && action.leave(this) == ASTVisitor.PROCESS_ABORT)
			return false;

        return true;
    }

	@Override
	public void replace(IASTNode child, IASTNode other) {
		if (child == fCondition) {
			other.setPropertyInParent(child.getPropertyInParent());
			other.setParent(child.getParent());
			fCondition = (ICPPASTExpression) other;
		}
		if (child == fPositive) {
			other.setPropertyInParent(child.getPropertyInParent());
			other.setParent(child.getParent());
			fPositive = (ICPPASTExpression) other;
		}
		if (child == fNegative) {
			other.setPropertyInParent(child.getPropertyInParent());
			other.setParent(child.getParent());
			fNegative = (ICPPASTExpression) other;
		}
	}

	private boolean isThrowExpression(IASTExpression expr) {
		while (expr instanceof IASTUnaryExpression) {
			final IASTUnaryExpression unaryExpr = (IASTUnaryExpression) expr;
			final int op = unaryExpr.getOperator();
			if (op == IASTUnaryExpression.op_throw) {
				return true;
			} else if (op == IASTUnaryExpression.op_bracketedPrimary) {
				expr= unaryExpr.getOperand();
			} else {
				return false;
			}
		}
		return false;
	}

	@Override
	public ICPPEvaluation getEvaluation() {
		if (fEval == null) {
			if (fCondition == null || fNegative == null) {
				fEval= EvalFixed.INCOMPLETE;
			} else {
				final ICPPEvaluation condEval = fCondition.getEvaluation();
				final ICPPEvaluation posEval = fPositive == null ? null : fPositive.getEvaluation();
				fEval= new EvalConditional(condEval, posEval, fNegative.getEvaluation(),
						isThrowExpression(fPositive), isThrowExpression(fNegative));
			}
		}
		return fEval;
	}
	
    @Override
	public IType getExpressionType() {
    	return getEvaluation().getTypeOrFunctionSet(this);
    }
    
	@Override
	public ValueCategory getValueCategory() {
    	return getEvaluation().getValueCategory(this);
    }

	@Override
	public boolean isLValue() {
		return getValueCategory() == LVALUE;
	}
}