--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2004 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.internal.compiler.ast;
+
+import org.eclipse.jdt.core.compiler.CharOperation;
+import org.eclipse.jdt.internal.compiler.ASTVisitor;
+import org.eclipse.jdt.internal.compiler.impl.*;
+import org.eclipse.jdt.internal.compiler.codegen.*;
+import org.eclipse.jdt.internal.compiler.flow.*;
+import org.eclipse.jdt.internal.compiler.lookup.*;
+
+public class EqualExpression extends BinaryExpression {
+
+public EqualExpression(Expression left, Expression right,int operator) {
+ super(left,right,operator);
+}
+public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
+ if (((bits & OperatorMASK) >> OperatorSHIFT) == EQUAL_EQUAL) {
+ if ((left.constant != NotAConstant) && (left.constant.typeID() == T_boolean)) {
+ if (left.constant.booleanValue()) { // true == anything
+ // this is equivalent to the right argument inits
+ return right.analyseCode(currentScope, flowContext, flowInfo);
+ } else { // false == anything
+ // this is equivalent to the right argument inits negated
+ return right.analyseCode(currentScope, flowContext, flowInfo).asNegatedCondition();
+ }
+ }
+ if ((right.constant != NotAConstant) && (right.constant.typeID() == T_boolean)) {
+ if (right.constant.booleanValue()) { // anything == true
+ // this is equivalent to the right argument inits
+ return left.analyseCode(currentScope, flowContext, flowInfo);
+ } else { // anything == false
+ // this is equivalent to the right argument inits negated
+ return left.analyseCode(currentScope, flowContext, flowInfo).asNegatedCondition();
+ }
+ }
+ return right.analyseCode(
+ currentScope, flowContext,
+ left.analyseCode(currentScope, flowContext, flowInfo).unconditionalInits()).unconditionalInits();
+ } else { //NOT_EQUAL :
+ if ((left.constant != NotAConstant) && (left.constant.typeID() == T_boolean)) {
+ if (!left.constant.booleanValue()) { // false != anything
+ // this is equivalent to the right argument inits
+ return right.analyseCode(currentScope, flowContext, flowInfo);
+ } else { // true != anything
+ // this is equivalent to the right argument inits negated
+ return right.analyseCode(currentScope, flowContext, flowInfo).asNegatedCondition();
+ }
+ }
+ if ((right.constant != NotAConstant) && (right.constant.typeID() == T_boolean)) {
+ if (!right.constant.booleanValue()) { // anything != false
+ // this is equivalent to the right argument inits
+ return left.analyseCode(currentScope, flowContext, flowInfo);
+ } else { // anything != true
+ // this is equivalent to the right argument inits negated
+ return left.analyseCode(currentScope, flowContext, flowInfo).asNegatedCondition();
+ }
+ }
+ return right.analyseCode(
+ currentScope, flowContext,
+ left.analyseCode(currentScope, flowContext, flowInfo).unconditionalInits()).asNegatedCondition().unconditionalInits();
+ }
+}
+public final boolean areTypesCastCompatible(BlockScope scope, TypeBinding castType, TypeBinding expressionType) {
+ //see specifications 5.5
+ //A more complete version of this method is provided on
+ //CastExpression (it deals with constant and need runtime checkcast)
+
+ if (castType == expressionType) return true;
+
+ //========ARRAY===============
+ if (expressionType.isArrayType()) {
+ if (castType.isArrayType()) { //------- (castTb.isArray) expressionTb.isArray -----------
+ TypeBinding expressionEltType = ((ArrayBinding) expressionType).elementsType(scope);
+ if (expressionEltType.isBaseType())
+ // <---stop the recursion-------
+ return ((ArrayBinding) castType).elementsType(scope) == expressionEltType;
+ //recursivly on the elts...
+ return areTypesCastCompatible(scope, ((ArrayBinding) castType).elementsType(scope), expressionEltType);
+ }
+ if (castType.isBaseType()) {
+ return false;
+ }
+ if (castType.isClass()) { //------(castTb.isClass) expressionTb.isArray ---------------
+ if (castType.id == T_Object)
+ return true;
+ return false;
+ }
+ if (castType.isInterface()) { //------- (castTb.isInterface) expressionTb.isArray -----------
+ if (castType.id == T_JavaLangCloneable || castType.id == T_JavaIoSerializable) {
+ return true;
+ }
+ return false;
+ }
+
+ return false;
+ }
+
+ //------------(castType) null--------------
+ if (expressionType == NullBinding) {
+ return !castType.isBaseType();
+ }
+
+ //========BASETYPE==============
+ if (expressionType.isBaseType()) {
+ return false;
+ }
+
+
+ //========REFERENCE TYPE===================
+
+ if (expressionType.isClass()) {
+ if (castType.isArrayType()) { // ---- (castTb.isArray) expressionTb.isClass -------
+ if (expressionType.id == T_Object)
+ return true;
+ }
+ if (castType.isBaseType()) {
+ return false;
+ }
+ if (castType.isClass()) { // ----- (castTb.isClass) expressionTb.isClass ------
+ if (expressionType.isCompatibleWith(castType))
+ return true;
+ else {
+ if (castType.isCompatibleWith(expressionType)) {
+ return true;
+ }
+ return false;
+ }
+ }
+ if (castType.isInterface()) { // ----- (castTb.isInterface) expressionTb.isClass -------
+ if (expressionType.isCompatibleWith(castType))
+ return true;
+ if (!((ReferenceBinding) expressionType).isFinal()) {
+ return true;
+ }
+ //no subclass for expressionTb, thus compile-time check is valid
+ }
+
+ return false;
+ }
+ if (expressionType.isInterface()) {
+ if (castType.isArrayType()) { // ----- (castTb.isArray) expressionTb.isInterface ------
+ if (expressionType.id == T_JavaLangCloneable || expressionType.id == T_JavaIoSerializable)
+ //potential runtime error
+ {
+ return true;
+ }
+ return false;
+ }
+ if (castType.isBaseType()) {
+ return false;
+ }
+ if (castType.isClass()) { // ----- (castTb.isClass) expressionTb.isInterface --------
+ if (castType.id == T_Object)
+ return true;
+ if (((ReferenceBinding) castType).isFinal()) { //no subclass for castTb, thus compile-time check is valid
+ if (castType.isCompatibleWith(expressionType)) {
+ return true;
+ }
+ return false;
+ }
+ return true;
+ }
+ if (castType.isInterface()) { // ----- (castTb.isInterface) expressionTb.isInterface -------
+ if (expressionType.isCompatibleWith(castType))
+ return true;
+ if (!castType.isCompatibleWith(expressionType)) {
+ MethodBinding[] castTbMethods = ((ReferenceBinding) castType).methods();
+ int castTbMethodsLength = castTbMethods.length;
+ MethodBinding[] expressionTbMethods = ((ReferenceBinding) expressionType).methods();
+ int expressionTbMethodsLength = expressionTbMethods.length;
+ for (int i = 0; i < castTbMethodsLength; i++) {
+ for (int j = 0; j < expressionTbMethodsLength; j++) {
+ if (CharOperation.equals(castTbMethods[i].selector, expressionTbMethods[j].selector)) {
+ if (castTbMethods[i].returnType != expressionTbMethods[j].returnType) {
+ if (castTbMethods[i].areParametersEqual(expressionTbMethods[j])) {
+ return false;
+ }
+ }
+ }
+ }
+ }
+ }
+ return true;
+ }
+ return false;
+ }
+ return false;
+}
+public final void computeConstant(TypeBinding leftType, TypeBinding rightType) {
+ if ((this.left.constant != NotAConstant) && (this.right.constant != NotAConstant)) {
+ this.constant =
+ Constant.computeConstantOperationEQUAL_EQUAL(
+ left.constant,
+ leftType.id,
+ EQUAL_EQUAL,
+ right.constant,
+ rightType.id);
+ if (((this.bits & OperatorMASK) >> OperatorSHIFT) == NOT_EQUAL)
+ constant = Constant.fromValue(!constant.booleanValue());
+ } else {
+ this.constant = NotAConstant;
+ // no optimization for null == null
+ }
+}
+/**
+ * Normal == or != code generation.
+ *
+ * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
+ * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
+ * @param valueRequired boolean
+ */
+public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
+
+ if (constant != NotAConstant) {
+ int pc = codeStream.position;
+ if (valueRequired)
+ codeStream.generateConstant(constant, implicitConversion);
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ }
+ Label falseLabel;
+ bits |= OnlyValueRequiredMASK;
+ generateOptimizedBoolean(
+ currentScope,
+ codeStream,
+ null,
+ falseLabel = new Label(codeStream),
+ valueRequired);
+ if (falseLabel.hasForwardReferences()) {
+ if (valueRequired){
+ // comparison is TRUE
+ codeStream.iconst_1();
+ if ((bits & ValueForReturnMASK) != 0){
+ codeStream.ireturn();
+ // comparison is FALSE
+ falseLabel.place();
+ codeStream.iconst_0();
+ } else {
+ Label endLabel = new Label(codeStream);
+ codeStream.goto_(endLabel);
+ codeStream.decrStackSize(1);
+ // comparison is FALSE
+ falseLabel.place();
+ codeStream.iconst_0();
+ endLabel.place();
+ }
+ } else {
+ falseLabel.place();
+ }
+ }
+}
+/**
+ * Boolean operator code generation
+ * Optimized operations are: == and !=
+ */
+public void generateOptimizedBoolean(BlockScope currentScope, CodeStream codeStream, Label trueLabel, Label falseLabel, boolean valueRequired) {
+
+ if (constant != Constant.NotAConstant) {
+ super.generateOptimizedBoolean(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
+ return;
+ }
+ if (((bits & OperatorMASK) >> OperatorSHIFT) == EQUAL_EQUAL) {
+ if ((left.implicitConversion & 0xF) /*compile-time*/ == T_boolean) {
+ generateOptimizedBooleanEqual(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
+ } else {
+ generateOptimizedNonBooleanEqual(currentScope, codeStream, trueLabel, falseLabel, valueRequired);
+ }
+ } else {
+ if ((left.implicitConversion & 0xF) /*compile-time*/ == T_boolean) {
+ generateOptimizedBooleanEqual(currentScope, codeStream, falseLabel, trueLabel, valueRequired);
+ } else {
+ generateOptimizedNonBooleanEqual(currentScope, codeStream, falseLabel, trueLabel, valueRequired);
+ }
+ }
+}
+/**
+ * Boolean generation for == with boolean operands
+ *
+ * Note this code does not optimize conditional constants !!!!
+ */
+public void generateOptimizedBooleanEqual(BlockScope currentScope, CodeStream codeStream, Label trueLabel, Label falseLabel, boolean valueRequired) {
+
+ // optimized cases: true == x, false == x
+ if (left.constant != NotAConstant) {
+ boolean inline = left.constant.booleanValue();
+ right.generateOptimizedBoolean(currentScope, codeStream, (inline ? trueLabel : falseLabel), (inline ? falseLabel : trueLabel), valueRequired);
+ return;
+ } // optimized cases: x == true, x == false
+ if (right.constant != NotAConstant) {
+ boolean inline = right.constant.booleanValue();
+ left.generateOptimizedBoolean(currentScope, codeStream, (inline ? trueLabel : falseLabel), (inline ? falseLabel : trueLabel), valueRequired);
+ return;
+ }
+ // default case
+ left.generateCode(currentScope, codeStream, valueRequired);
+ right.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ codeStream.if_icmpeq(trueLabel);
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ codeStream.if_icmpne(falseLabel);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ // reposition the endPC
+ codeStream.updateLastRecordedEndPC(codeStream.position);
+}
+/**
+ * Boolean generation for == with non-boolean operands
+ *
+ */
+public void generateOptimizedNonBooleanEqual(BlockScope currentScope, CodeStream codeStream, Label trueLabel, Label falseLabel, boolean valueRequired) {
+
+ int pc = codeStream.position;
+ Constant inline;
+ if ((inline = right.constant) != NotAConstant) {
+ // optimized case: x == 0
+ if (((left.implicitConversion >> 4) == T_int) && (inline.intValue() == 0)) {
+ left.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ codeStream.ifeq(trueLabel);
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ codeStream.ifne(falseLabel);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ }
+ }
+ if ((inline = left.constant) != NotAConstant) {
+ // optimized case: 0 == x
+ if (((left.implicitConversion >> 4) == T_int)
+ && (inline.intValue() == 0)) {
+ right.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ codeStream.ifeq(trueLabel);
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ codeStream.ifne(falseLabel);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ }
+ }
+ // null cases
+ // optimized case: x == null
+ if (right instanceof NullLiteral) {
+ if (left instanceof NullLiteral) {
+ // null == null
+ if (valueRequired) {
+ if ((bits & OnlyValueRequiredMASK) != 0) {
+ if (((bits & OperatorMASK) >> OperatorSHIFT) == EQUAL_EQUAL) {
+ codeStream.iconst_1();
+ } else {
+ codeStream.iconst_0();
+ }
+ } else {
+ if (falseLabel == null) {
+ // implicit falling through the FALSE case
+ if (trueLabel != null) {
+ codeStream.goto_(trueLabel);
+ }
+ }
+ }
+ }
+ } else {
+ left.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ codeStream.ifnull(trueLabel);
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ codeStream.ifnonnull(falseLabel);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ } else if (left instanceof NullLiteral) { // optimized case: null == x
+ right.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ codeStream.ifnull(trueLabel);
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ codeStream.ifnonnull(falseLabel);
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+ return;
+ }
+
+ // default case
+ left.generateCode(currentScope, codeStream, valueRequired);
+ right.generateCode(currentScope, codeStream, valueRequired);
+ if (valueRequired) {
+ if (falseLabel == null) {
+ if (trueLabel != null) {
+ // implicit falling through the FALSE case
+ switch (left.implicitConversion >> 4) { // operand runtime type
+ case T_int :
+ codeStream.if_icmpeq(trueLabel);
+ break;
+ case T_float :
+ codeStream.fcmpl();
+ codeStream.ifeq(trueLabel);
+ break;
+ case T_long :
+ codeStream.lcmp();
+ codeStream.ifeq(trueLabel);
+ break;
+ case T_double :
+ codeStream.dcmpl();
+ codeStream.ifeq(trueLabel);
+ break;
+ default :
+ codeStream.if_acmpeq(trueLabel);
+ }
+ }
+ } else {
+ // implicit falling through the TRUE case
+ if (trueLabel == null) {
+ switch (left.implicitConversion >> 4) { // operand runtime type
+ case T_int :
+ codeStream.if_icmpne(falseLabel);
+ break;
+ case T_float :
+ codeStream.fcmpl();
+ codeStream.ifne(falseLabel);
+ break;
+ case T_long :
+ codeStream.lcmp();
+ codeStream.ifne(falseLabel);
+ break;
+ case T_double :
+ codeStream.dcmpl();
+ codeStream.ifne(falseLabel);
+ break;
+ default :
+ codeStream.if_acmpne(falseLabel);
+ }
+ } else {
+ // no implicit fall through TRUE/FALSE --> should never occur
+ }
+ }
+ }
+ codeStream.recordPositionsFrom(pc, this.sourceStart);
+}
+public boolean isCompactableOperation() {
+ return false;
+}
+public TypeBinding resolveType(BlockScope scope) {
+
+ boolean leftIsCast, rightIsCast;
+ if ((leftIsCast = left instanceof CastExpression) == true) left.bits |= IgnoreNeedForCastCheckMASK; // will check later on
+ TypeBinding leftType = left.resolveType(scope);
+
+ if ((rightIsCast = right instanceof CastExpression) == true) right.bits |= IgnoreNeedForCastCheckMASK; // will check later on
+ TypeBinding rightType = right.resolveType(scope);
+
+ // always return BooleanBinding
+ if (leftType == null || rightType == null){
+ constant = NotAConstant;
+ return null;
+ }
+
+ // both base type
+ if (leftType.isBaseType() && rightType.isBaseType()) {
+ // the code is an int
+ // (cast) left == (cast) right --> result
+ // 0000 0000 0000 0000 0000
+ // <<16 <<12 <<8 <<4 <<0
+ int operatorSignature = OperatorSignatures[EQUAL_EQUAL][ (leftType.id << 4) + rightType.id];
+ left.implicitConversion = operatorSignature >>> 12;
+ right.implicitConversion = (operatorSignature >>> 4) & 0x000FF;
+ bits |= operatorSignature & 0xF;
+ if ((operatorSignature & 0x0000F) == T_undefined) {
+ constant = Constant.NotAConstant;
+ scope.problemReporter().invalidOperator(this, leftType, rightType);
+ return null;
+ }
+ // check need for operand cast
+ if (leftIsCast || rightIsCast) {
+ CastExpression.checkNeedForArgumentCasts(scope, EQUAL_EQUAL, operatorSignature, left, leftType.id, leftIsCast, right, rightType.id, rightIsCast);
+ }
+ computeConstant(leftType, rightType);
+ return this.resolvedType = BooleanBinding;
+ }
+
+ // Object references
+ // spec 15.20.3
+ if (areTypesCastCompatible(scope, rightType, leftType) || areTypesCastCompatible(scope, leftType, rightType)) {
+ // (special case for String)
+ if ((rightType.id == T_String) && (leftType.id == T_String)) {
+ computeConstant(leftType, rightType);
+ } else {
+ constant = NotAConstant;
+ }
+ if (rightType.id == T_String) {
+ right.implicitConversion = String2String;
+ }
+ if (leftType.id == T_String) {
+ left.implicitConversion = String2String;
+ }
+ // check need for operand cast
+ boolean unnecessaryLeftCast = (left.bits & UnnecessaryCastMask) != 0;
+ boolean unnecessaryRightCast = (right.bits & UnnecessaryCastMask) != 0;
+ if (unnecessaryLeftCast || unnecessaryRightCast) {
+ TypeBinding alternateLeftType = unnecessaryLeftCast ? ((CastExpression)left).expression.resolvedType : leftType;
+ TypeBinding alternateRightType = unnecessaryRightCast ? ((CastExpression)right).expression.resolvedType : rightType;
+ if (areTypesCastCompatible(scope, alternateLeftType, alternateRightType)
+ || areTypesCastCompatible(scope, alternateRightType, alternateLeftType)) {
+ if (unnecessaryLeftCast) scope.problemReporter().unnecessaryCast((CastExpression)left);
+ if (unnecessaryRightCast) scope.problemReporter().unnecessaryCast((CastExpression)right);
+ }
+ }
+ return this.resolvedType = BooleanBinding;
+ }
+ constant = NotAConstant;
+ scope.problemReporter().notCompatibleTypesError(this, leftType, rightType);
+ return null;
+}
+public void traverse(ASTVisitor visitor, BlockScope scope) {
+ if (visitor.visit(this, scope)) {
+ left.traverse(visitor, scope);
+ right.traverse(visitor, scope);
+ }
+ visitor.endVisit(this, scope);
+}
+}