/*******************************************************************************
* Copyright (c) 2000, 2009 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.wst.jsdt.internal.compiler.ast;
import org.eclipse.wst.jsdt.core.ast.IASTNode;
import org.eclipse.wst.jsdt.core.ast.ICompoundAssignment;
import org.eclipse.wst.jsdt.internal.compiler.ASTVisitor;
import org.eclipse.wst.jsdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.wst.jsdt.internal.compiler.flow.FlowContext;
import org.eclipse.wst.jsdt.internal.compiler.flow.FlowInfo;
import org.eclipse.wst.jsdt.internal.compiler.impl.Constant;
import org.eclipse.wst.jsdt.internal.compiler.lookup.BlockScope;
import org.eclipse.wst.jsdt.internal.compiler.lookup.LookupEnvironment;
import org.eclipse.wst.jsdt.internal.compiler.lookup.TypeBinding;
public class CompoundAssignment extends Assignment implements OperatorIds, ICompoundAssignment {
public int operator;
public int preAssignImplicitConversion;
// var op exp is equivalent to var = (varType) var op exp
// assignmentImplicitConversion stores the cast needed for the assignment
public CompoundAssignment(Expression lhs, Expression expression,int operator, int sourceEnd) {
//lhs is always a reference by construction ,
//but is build as an expression ==> the checkcast cannot fail
super(lhs, expression, sourceEnd);
lhs.bits &= ~IsStrictlyAssigned; // tag lhs as NON assigned - it is also a read access
lhs.bits |= IsCompoundAssigned; // tag lhs as assigned by compound
this.operator = operator ;
}
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext,
FlowInfo flowInfo) {
// record setting a variable: various scenarii are possible, setting an array reference,
// a field reference, a blank final field reference, a field of an enclosing instance or
// just a local variable.
if (this.resolvedType.id != T_JavaLangString) {
lhs.checkNPE(currentScope, flowContext, flowInfo);
}
return ((Reference) lhs).analyseAssignment(currentScope, flowContext, flowInfo, this, true).unconditionalInits();
}
public int nullStatus(FlowInfo flowInfo) {
return FlowInfo.NON_NULL;
// we may have complained on checkNPE, but we avoid duplicate error
}
public String operatorToString() {
switch (operator) {
case PLUS :
return "+="; //$NON-NLS-1$
case MINUS :
return "-="; //$NON-NLS-1$
case MULTIPLY :
return "*="; //$NON-NLS-1$
case DIVIDE :
return "/="; //$NON-NLS-1$
case AND :
return "&="; //$NON-NLS-1$
case OR :
return "|="; //$NON-NLS-1$
case XOR :
return "^="; //$NON-NLS-1$
case REMAINDER :
return "%="; //$NON-NLS-1$
case LEFT_SHIFT :
return "<<="; //$NON-NLS-1$
case RIGHT_SHIFT :
return ">>="; //$NON-NLS-1$
case UNSIGNED_RIGHT_SHIFT :
return ">>>="; //$NON-NLS-1$
}
return "unknown operator"; //$NON-NLS-1$
}
public StringBuffer printExpressionNoParenthesis(int indent, StringBuffer output) {
lhs.printExpression(indent, output).append(' ').append(operatorToString()).append(' ');
return expression.printExpression(0, output) ;
}
public TypeBinding resolveType(BlockScope scope) {
constant = Constant.NotAConstant;
if (!(this.lhs instanceof Reference) || this.lhs.isThis()) {
scope.problemReporter().expressionShouldBeAVariable(this.lhs);
return null;
}
TypeBinding originalLhsType = lhs.resolveType(scope);
TypeBinding originalExpressionType = expression.resolveType(scope);
this.resolvedType=TypeBinding.ANY;
if (originalLhsType == null || originalExpressionType == null)
{
return null;
}
// autoboxing support
LookupEnvironment env = scope.environment();
TypeBinding lhsType = originalLhsType, expressionType = originalExpressionType;
boolean use15specifics = scope.compilerOptions().sourceLevel >= ClassFileConstants.JDK1_5;
boolean unboxedLhs = false;
if (use15specifics) {
if (!lhsType.isBaseType() && expressionType.id != T_JavaLangString && expressionType.id != T_null) {
TypeBinding unboxedType = env.computeBoxingType(lhsType);
if (unboxedType != lhsType) {
lhsType = unboxedType;
unboxedLhs = true;
}
}
if (!expressionType.isBaseType() && lhsType.id != T_JavaLangString && lhsType.id != T_null) {
expressionType = env.computeBoxingType(expressionType);
}
}
if (restrainUsageToNumericTypes() && !lhsType.isNumericType() && !lhsType.isAnyType()) {
scope.problemReporter().operatorOnlyValidOnNumericType(this, lhsType, expressionType);
return null;
}
int lhsID = lhsType.id;
int expressionID = expressionType.id;
if (lhsID > 15 || expressionID > 15) {
if (lhsID != T_JavaLangString) { // String += Thread is valid whereas Thread += String is not
scope.problemReporter().invalidOperator(this, lhsType, expressionType);
return null;
}
expressionID = T_JavaLangObject; // use the Object has tag table
}
// the code is an int
// (cast) left Op (cast) rigth --> result
// 0000 0000 0000 0000 0000
// <<16 <<12 <<8 <<4 <<0
// the conversion is stored INTO the reference (info needed for the code gen)
int result = OperatorExpression.OperatorSignatures[operator][ (lhsID << 4) + expressionID];
if (result == T_undefined) {
scope.problemReporter().invalidOperator(this, lhsType, expressionType);
return null;
}
// if (operator == PLUS){
// if(lhsID == T_JavaLangObject) {
// // <Object> += <String> is illegal (39248)
// scope.problemReporter().invalidOperator(this, lhsType, expressionType);
// return null;
// } else {
// // <int | boolean> += <String> is illegal
// if ((lhsType.isNumericType() || lhsID == T_boolean) && !expressionType.isNumericType()){
// scope.problemReporter().invalidOperator(this, lhsType, expressionType);
// return null;
// }
// }
// }
this.preAssignImplicitConversion = (unboxedLhs ? BOXING : 0) | (lhsID << 4) | (result & 0x0000F);
return this.resolvedType = originalLhsType;
}
public boolean restrainUsageToNumericTypes(){
return false ;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
lhs.traverse(visitor, scope);
expression.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
public int getASTType() {
return IASTNode.COMPOUND_ASSIGNMENT;
}
}