/*******************************************************************************
* 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.jdt.internal.compiler.ast;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.flow.FlowContext;
import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
public class CompoundAssignment extends Assignment implements OperatorIds {
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) {
this.lhs.checkNPE(currentScope, flowContext, flowInfo);
}
return ((Reference)this.lhs).analyseAssignment(currentScope, flowContext, flowInfo, this, true).unconditionalInits();
}
public boolean checkCastCompatibility() {
return true;
}
public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
// 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.
int pc= codeStream.position;
((Reference)this.lhs).generateCompoundAssignment(currentScope, codeStream, this.expression, this.operator, this.preAssignImplicitConversion, valueRequired);
if (valueRequired) {
codeStream.generateImplicitConversion(this.implicitConversion);
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
public int nullStatus(FlowInfo flowInfo) {
return FlowInfo.NON_NULL;
// we may have complained on checkNPE, but we avoid duplicate error
}
public String operatorToString() {
switch (this.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) {
this.lhs.printExpression(indent, output).append(' ').append(operatorToString()).append(' ');
return this.expression.printExpression(0, output);
}
public TypeBinding resolveType(BlockScope scope) {
this.constant= Constant.NotAConstant;
if (!(this.lhs instanceof Reference) || this.lhs.isThis()) {
scope.problemReporter().expressionShouldBeAVariable(this.lhs);
return null;
}
boolean expressionIsCast= this.expression instanceof CastExpression;
if (expressionIsCast)
this.expression.bits|= ASTNode.DisableUnnecessaryCastCheck; // will check later on
TypeBinding originalLhsType= this.lhs.resolveType(scope);
TypeBinding originalExpressionType= this.expression.resolveType(scope);
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()) {
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[this.operator][(lhsID << 4) + expressionID];
if (result == T_undefined) {
scope.problemReporter().invalidOperator(this, lhsType, expressionType);
return null;
}
if (this.operator == PLUS) {
if (lhsID == T_JavaLangObject && (scope.compilerOptions().complianceLevel < ClassFileConstants.JDK1_7)) {
// <Object> += <String> is illegal (39248) for compliance < 1.7
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;
}
}
}
TypeBinding resultType= TypeBinding.wellKnownType(scope, result & 0x0000F);
if (checkCastCompatibility()) {
if (originalLhsType.id != T_JavaLangString && resultType.id != T_JavaLangString) {
if (!checkCastTypesCompatibility(scope, originalLhsType, resultType, null)) {
scope.problemReporter().invalidOperator(this, originalLhsType, expressionType);
return null;
}
}
}
this.lhs.computeConversion(scope, TypeBinding.wellKnownType(scope, (result >>> 16) & 0x0000F), originalLhsType);
this.expression.computeConversion(scope, TypeBinding.wellKnownType(scope, (result >>> 8) & 0x0000F), originalExpressionType);
this.preAssignImplicitConversion= (unboxedLhs ? BOXING : 0) | (lhsID << 4) | (result & 0x0000F);
if (unboxedLhs)
scope.problemReporter().autoboxing(this, lhsType, originalLhsType);
if (expressionIsCast)
CastExpression.checkNeedForArgumentCasts(scope, this.operator, result, this.lhs, originalLhsType.id, false, this.expression, originalExpressionType.id, true);
return this.resolvedType= originalLhsType;
}
public boolean restrainUsageToNumericTypes() {
return false;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
this.lhs.traverse(visitor, scope);
this.expression.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
}