| /******************************************************************************* |
| * 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.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 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 (this.checkCastTypesCompatibility(scope, leftType, rightType, null) |
| || this.checkCastTypesCompatibility(scope, rightType, leftType, null)) { |
| |
| // (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 (this.checkCastTypesCompatibility(scope, alternateLeftType, alternateRightType, null) |
| || this.checkCastTypesCompatibility(scope, alternateRightType, alternateLeftType, null)) { |
| 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); |
| } |
| } |
