OR_OR_Expression.java
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net.sourceforge.phpdt.internal.compiler.ast |
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PHPeclipse |
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These are the metrics that contribute to the Enerjy Score for this file, ranked by impact. So the metrics listed at the top influence the score to a greater extent that the metrics listed at the bottom.
/*******************************************************************************
* Copyright (c) 2000, 2003 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 net.sourceforge.phpdt.internal.compiler.ast;
import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
import net.sourceforge.phpdt.internal.compiler.impl.Constant;
import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
// dedicated treatment for the ||
public class OR_OR_Expression extends BinaryExpression {
int rightInitStateIndex = -1;
int mergedInitStateIndex = -1;
public OR_OR_Expression(Expression left, Expression right, int operator) {
super(left, right, operator);
}
public FlowInfo analyseCode(BlockScope currentScope,
FlowContext flowContext, FlowInfo flowInfo) {
Constant cst = this.left.optimizedBooleanConstant();
boolean isLeftOptimizedTrue = cst != NotAConstant
&& cst.booleanValue() == true;
boolean isLeftOptimizedFalse = cst != NotAConstant
&& cst.booleanValue() == false;
if (isLeftOptimizedFalse) {
// FALSE || anything
// need to be careful of scenario:
// (x || y) || !z, if passing the left info to the right, it would
// be swapped by the !
FlowInfo mergedInfo = left.analyseCode(currentScope, flowContext,
flowInfo).unconditionalInits();
mergedInfo = right.analyseCode(currentScope, flowContext,
mergedInfo);
mergedInitStateIndex = currentScope.methodScope()
.recordInitializationStates(mergedInfo);
return mergedInfo;
}
FlowInfo leftInfo = left.analyseCode(currentScope, flowContext,
flowInfo);
// need to be careful of scenario:
// (x || y) || !z, if passing the left info to the right, it would be
// swapped by the !
FlowInfo rightInfo = leftInfo.initsWhenFalse().unconditionalInits()
.copy();
rightInitStateIndex = currentScope.methodScope()
.recordInitializationStates(rightInfo);
int previousMode = rightInfo.reachMode();
if (isLeftOptimizedTrue) {
rightInfo.setReachMode(FlowInfo.UNREACHABLE);
}
rightInfo = right.analyseCode(currentScope, flowContext, rightInfo);
FlowInfo falseMergedInfo = rightInfo.initsWhenFalse().copy();
rightInfo.setReachMode(previousMode); // reset after falseMergedInfo
// got extracted
FlowInfo mergedInfo = FlowInfo
.conditional(
// merging two true initInfos for such a negative case:
// if ((t && (b = t)) || f) r = b; // b may not have
// been initialized
leftInfo.initsWhenTrue().copy().unconditionalInits()
.mergedWith(
rightInfo.initsWhenTrue().copy()
.unconditionalInits()),
falseMergedInfo);
mergedInitStateIndex = currentScope.methodScope()
.recordInitializationStates(mergedInfo);
return mergedInfo;
}
/**
* Code generation for a binary operation
*
* @param currentScope
* net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
* @param codeStream
* net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
* @param valueRequired
* boolean
*/
// public void generateCode(
// BlockScope currentScope,
// CodeStream codeStream,
// boolean valueRequired) {
// int pc = codeStream.position;
// Label falseLabel, endLabel;
// if (constant != Constant.NotAConstant) {
// if (valueRequired)
// codeStream.generateConstant(constant, implicitConversion);
// codeStream.recordPositionsFrom(pc, this.sourceStart);
// return;
// }
// bits |= OnlyValueRequiredMASK;
// generateOptimizedBoolean(
// currentScope,
// codeStream,
// null,
// (falseLabel = new Label(codeStream)),
// valueRequired);
// /* improving code gen for such a case: boolean b = i < 0 || true;
// * since the label has never been used, we have the inlined value on the
// stack. */
// if (falseLabel.hasForwardReferences()) {
// if (valueRequired) {
// codeStream.iconst_1();
// if ((bits & ValueForReturnMASK) != 0) {
// codeStream.ireturn();
// falseLabel.place();
// codeStream.iconst_0();
// } else {
// codeStream.goto_(endLabel = new Label(codeStream));
// codeStream.decrStackSize(1);
// falseLabel.place();
// codeStream.iconst_0();
// endLabel.place();
// }
// } else {
// falseLabel.place();
// }
// }
// if (valueRequired) {
// codeStream.generateImplicitConversion(implicitConversion);
// }
// codeStream.recordPositionsFrom(pc, this.sourceStart);
// }
//
// /**
// * Boolean operator code generation
// * Optimized operations are: ||
// */
// 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;
// }
// Constant condConst;
// if ((condConst = left.optimizedBooleanConstant()) != NotAConstant) {
// if (condConst.booleanValue() == true) {
// // <something equivalent to true> || x
// left.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// false);
// if (valueRequired) {
// if ((bits & OnlyValueRequiredMASK) != 0) {
// codeStream.iconst_1();
// } else {
// if (trueLabel != null) {
// codeStream.goto_(trueLabel);
// }
// }
// }
// // reposition the endPC
// codeStream.updateLastRecordedEndPC(codeStream.position);
// } else {
// // <something equivalent to false> || x
// left.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// false);
// if (rightInitStateIndex != -1) {
// codeStream.addDefinitelyAssignedVariables(currentScope,
// rightInitStateIndex);
// }
// if ((bits & OnlyValueRequiredMASK) != 0) {
// right.generateCode(currentScope, codeStream, valueRequired);
// } else {
// right.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// valueRequired);
// }
// }
// if (mergedInitStateIndex != -1) {
// codeStream.removeNotDefinitelyAssignedVariables(
// currentScope,
// mergedInitStateIndex);
// }
// return;
// }
// if ((condConst = right.optimizedBooleanConstant()) != NotAConstant) {
// if (condConst.booleanValue() == true) {
// // x || <something equivalent to true>
// Label internalFalseLabel = new Label(codeStream);
// left.generateOptimizedBoolean(
// currentScope,
// codeStream,
// null,
// internalFalseLabel, // will be true in the end
// false);
// if (rightInitStateIndex != -1) {
// codeStream.addDefinitelyAssignedVariables(currentScope,
// rightInitStateIndex);
// }
// internalFalseLabel.place();
// right.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// false);
// if (valueRequired) {
// if ((bits & OnlyValueRequiredMASK) != 0) {
// codeStream.iconst_1();
// } else {
// if (trueLabel != null) {
// codeStream.goto_(trueLabel);
// }
// }
// }
// // reposition the endPC
// codeStream.updateLastRecordedEndPC(codeStream.position);
// } else {
// // x || <something equivalent to false>
// if ((bits & OnlyValueRequiredMASK) != 0) {
// left.generateCode(currentScope, codeStream, valueRequired);
// } else {
// left.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// valueRequired);
// }
// if (rightInitStateIndex != -1) {
// codeStream.addDefinitelyAssignedVariables(currentScope,
// rightInitStateIndex);
// }
// right.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// falseLabel,
// false);
// }
// if (mergedInitStateIndex != -1) {
// codeStream.removeNotDefinitelyAssignedVariables(
// currentScope,
// mergedInitStateIndex);
// }
// return;
// }
// // default case
// if (falseLabel == null) {
// if (trueLabel != null) {
// // implicit falling through the FALSE case
// left.generateOptimizedBoolean(currentScope, codeStream, trueLabel, null,
// true);
// right.generateOptimizedBoolean(
// currentScope,
// codeStream,
// trueLabel,
// null,
// valueRequired);
// }
// } else {
// // implicit falling through the TRUE case
// if (trueLabel == null) {
// Label internalTrueLabel = new Label(codeStream);
// left.generateOptimizedBoolean(
// currentScope,
// codeStream,
// internalTrueLabel,
// null,
// true);
// if (rightInitStateIndex != -1) {
// codeStream.addDefinitelyAssignedVariables(currentScope,
// rightInitStateIndex);
// }
// right.generateOptimizedBoolean(
// currentScope,
// codeStream,
// null,
// falseLabel,
// valueRequired);
// internalTrueLabel.place();
// } else {
// // no implicit fall through TRUE/FALSE --> should never occur
// }
// }
// if (mergedInitStateIndex != -1) {
// codeStream.removeNotDefinitelyAssignedVariables(
// currentScope,
// mergedInitStateIndex);
// }
// }
public boolean isCompactableOperation() {
return false;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
left.traverse(visitor, scope);
right.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
}
The table below shows all metrics for OR_OR_Expression.java.




