/*******************************************************************************
* Copyright (c) 2000, 2013 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
* Stephan Herrmann - Contribution for
* bug 345305 - [compiler][null] Compiler misidentifies a case of "variable can only be null"
* bug 392862 - [1.8][compiler][null] Evaluate null annotations on array types
* bug 383368 - [compiler][null] syntactic null analysis for field references
* bug 403147 - [compiler][null] FUP of bug 400761: consolidate interaction between unboxing, NPE, and deferred checking
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
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.ArrayBinding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.TagBits;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeIds;
public class ArrayReference extends Reference {
public Expression receiver;
public Expression position;
public ArrayReference(Expression rec, Expression pos) {
this.receiver = rec;
this.position = pos;
this.sourceStart = rec.sourceStart;
}
public FlowInfo analyseAssignment(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, Assignment assignment, boolean compoundAssignment) {
// TODO (maxime) optimization: unconditionalInits is applied to all existing calls
// account for potential ArrayIndexOutOfBoundsException:
flowContext.recordAbruptExit();
if (assignment.expression == null) {
return analyseCode(currentScope, flowContext, flowInfo);
}
flowInfo = assignment
.expression
.analyseCode(
currentScope,
flowContext,
analyseCode(currentScope, flowContext, flowInfo).unconditionalInits());
if ((this.resolvedType.tagBits & TagBits.AnnotationNonNull) != 0) {
int nullStatus = assignment.expression.nullStatus(flowInfo, flowContext);
if (nullStatus != FlowInfo.NON_NULL) {
currentScope.problemReporter().nullityMismatch(this, assignment.expression.resolvedType, this.resolvedType, nullStatus, currentScope.environment().getNonNullAnnotationName());
}
}
return flowInfo;
}
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
this.receiver.checkNPE(currentScope, flowContext, flowInfo);
flowInfo = this.receiver.analyseCode(currentScope, flowContext, flowInfo);
flowInfo = this.position.analyseCode(currentScope, flowContext, flowInfo);
this.position.checkNPEbyUnboxing(currentScope, flowContext, flowInfo);
// account for potential ArrayIndexOutOfBoundsException:
flowContext.recordAbruptExit();
return flowInfo;
}
public boolean checkNPE(BlockScope scope, FlowContext flowContext, FlowInfo flowInfo) {
if ((this.resolvedType.tagBits & TagBits.AnnotationNullable) != 0) {
scope.problemReporter().arrayReferencePotentialNullReference(this);
return true;
} else {
return super.checkNPE(scope, flowContext, flowInfo);
}
}
public void generateAssignment(BlockScope currentScope, CodeStream codeStream, Assignment assignment, boolean valueRequired) {
int pc = codeStream.position;
this.receiver.generateCode(currentScope, codeStream, true);
if (this.receiver instanceof CastExpression // ((type[])null)[0]
&& ((CastExpression)this.receiver).innermostCastedExpression().resolvedType == TypeBinding.NULL){
codeStream.checkcast(this.receiver.resolvedType);
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
this.position.generateCode(currentScope, codeStream, true);
assignment.expression.generateCode(currentScope, codeStream, true);
codeStream.arrayAtPut(this.resolvedType.id, valueRequired);
if (valueRequired) {
codeStream.generateImplicitConversion(assignment.implicitConversion);
}
}
/**
* Code generation for a array reference
*/
public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
int pc = codeStream.position;
this.receiver.generateCode(currentScope, codeStream, true);
if (this.receiver instanceof CastExpression // ((type[])null)[0]
&& ((CastExpression)this.receiver).innermostCastedExpression().resolvedType == TypeBinding.NULL){
codeStream.checkcast(this.receiver.resolvedType);
}
this.position.generateCode(currentScope, codeStream, true);
codeStream.arrayAt(this.resolvedType.id);
// Generating code for the potential runtime type checking
if (valueRequired) {
codeStream.generateImplicitConversion(this.implicitConversion);
} else {
boolean isUnboxing = (this.implicitConversion & TypeIds.UNBOXING) != 0;
// conversion only generated if unboxing
if (isUnboxing) codeStream.generateImplicitConversion(this.implicitConversion);
switch (isUnboxing ? postConversionType(currentScope).id : this.resolvedType.id) {
case T_long :
case T_double :
codeStream.pop2();
break;
default :
codeStream.pop();
}
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
public void generateCompoundAssignment(BlockScope currentScope, CodeStream codeStream, Expression expression, int operator, int assignmentImplicitConversion, boolean valueRequired) {
this.receiver.generateCode(currentScope, codeStream, true);
if (this.receiver instanceof CastExpression // ((type[])null)[0]
&& ((CastExpression)this.receiver).innermostCastedExpression().resolvedType == TypeBinding.NULL){
codeStream.checkcast(this.receiver.resolvedType);
}
this.position.generateCode(currentScope, codeStream, true);
codeStream.dup2();
codeStream.arrayAt(this.resolvedType.id);
int operationTypeID;
switch(operationTypeID = (this.implicitConversion & TypeIds.IMPLICIT_CONVERSION_MASK) >> 4) {
case T_JavaLangString :
case T_JavaLangObject :
case T_undefined :
codeStream.generateStringConcatenationAppend(currentScope, null, expression);
break;
default :
// promote the array reference to the suitable operation type
codeStream.generateImplicitConversion(this.implicitConversion);
// generate the increment value (will by itself be promoted to the operation value)
if (expression == IntLiteral.One) { // prefix operation
codeStream.generateConstant(expression.constant, this.implicitConversion);
} else {
expression.generateCode(currentScope, codeStream, true);
}
// perform the operation
codeStream.sendOperator(operator, operationTypeID);
// cast the value back to the array reference type
codeStream.generateImplicitConversion(assignmentImplicitConversion);
}
codeStream.arrayAtPut(this.resolvedType.id, valueRequired);
}
public void generatePostIncrement(BlockScope currentScope, CodeStream codeStream, CompoundAssignment postIncrement, boolean valueRequired) {
this.receiver.generateCode(currentScope, codeStream, true);
if (this.receiver instanceof CastExpression // ((type[])null)[0]
&& ((CastExpression)this.receiver).innermostCastedExpression().resolvedType == TypeBinding.NULL){
codeStream.checkcast(this.receiver.resolvedType);
}
this.position.generateCode(currentScope, codeStream, true);
codeStream.dup2();
codeStream.arrayAt(this.resolvedType.id);
if (valueRequired) {
switch(this.resolvedType.id) {
case TypeIds.T_long :
case TypeIds.T_double :
codeStream.dup2_x2();
break;
default :
codeStream.dup_x2();
break;
}
}
codeStream.generateImplicitConversion(this.implicitConversion);
codeStream.generateConstant(
postIncrement.expression.constant,
this.implicitConversion);
codeStream.sendOperator(postIncrement.operator, this.implicitConversion & TypeIds.COMPILE_TYPE_MASK);
codeStream.generateImplicitConversion(
postIncrement.preAssignImplicitConversion);
codeStream.arrayAtPut(this.resolvedType.id, false);
}
public StringBuffer printExpression(int indent, StringBuffer output) {
this.receiver.printExpression(0, output).append('[');
return this.position.printExpression(0, output).append(']');
}
public TypeBinding resolveType(BlockScope scope) {
this.constant = Constant.NotAConstant;
if (this.receiver instanceof CastExpression // no cast check for ((type[])null)[0]
&& ((CastExpression)this.receiver).innermostCastedExpression() instanceof NullLiteral) {
this.receiver.bits |= ASTNode.DisableUnnecessaryCastCheck; // will check later on
}
TypeBinding arrayType = this.receiver.resolveType(scope);
if (arrayType != null) {
this.receiver.computeConversion(scope, arrayType, arrayType);
if (arrayType.isArrayType()) {
TypeBinding elementType = ((ArrayBinding) arrayType).elementsType();
this.resolvedType = ((this.bits & ASTNode.IsStrictlyAssigned) == 0) ? elementType.capture(scope, this.sourceEnd) : elementType;
} else {
scope.problemReporter().referenceMustBeArrayTypeAt(arrayType, this);
}
}
TypeBinding positionType = this.position.resolveTypeExpecting(scope, TypeBinding.INT);
if (positionType != null) {
this.position.computeConversion(scope, TypeBinding.INT, positionType);
}
return this.resolvedType;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
this.receiver.traverse(visitor, scope);
this.position.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
}