org.eclipse.jdt.internal.compiler.ast.LabeledStatement Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2008 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.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.lookup.*;
public class LabeledStatement extends Statement {
public Statement statement;
public char[] label;
public BranchLabel targetLabel;
public int labelEnd;
// for local variables table attributes
int mergedInitStateIndex = -1;
/**
* LabeledStatement constructor comment.
*/
public LabeledStatement(char[] label, Statement statement, long labelPosition, int sourceEnd) {
this.statement = statement;
// remember useful empty statement
if (statement instanceof EmptyStatement) statement.bits |= IsUsefulEmptyStatement;
this.label = label;
this.sourceStart = (int)(labelPosition >>> 32);
this.labelEnd = (int) labelPosition;
this.sourceEnd = sourceEnd;
}
public FlowInfo analyseCode(
BlockScope currentScope,
FlowContext flowContext,
FlowInfo flowInfo) {
// need to stack a context to store explicit label, answer inits in case of normal completion merged
// with those relative to the exit path from break statement occurring inside the labeled statement.
if (this.statement == null) {
return flowInfo;
} else {
LabelFlowContext labelContext;
FlowInfo statementInfo, mergedInfo;
statementInfo = this.statement.analyseCode(
currentScope,
(labelContext =
new LabelFlowContext(
flowContext,
this,
this.label,
(this.targetLabel = new BranchLabel()),
currentScope)),
flowInfo);
boolean reinjectNullInfo = (statementInfo.tagBits & FlowInfo.UNREACHABLE) != 0 &&
(labelContext.initsOnBreak.tagBits & FlowInfo.UNREACHABLE) == 0;
mergedInfo = statementInfo.mergedWith(labelContext.initsOnBreak);
if (reinjectNullInfo) {
// an embedded loop has had no chance to reinject forgotten null info
((UnconditionalFlowInfo)mergedInfo).addInitializationsFrom(flowInfo.unconditionalFieldLessCopy()).
addInitializationsFrom(labelContext.initsOnBreak.unconditionalFieldLessCopy());
}
this.mergedInitStateIndex =
currentScope.methodScope().recordInitializationStates(mergedInfo);
if ((this.bits & ASTNode.LabelUsed) == 0) {
currentScope.problemReporter().unusedLabel(this);
}
return mergedInfo;
}
}
public ASTNode concreteStatement() {
// return statement.concreteStatement(); // for supporting nested labels: a:b:c: someStatement (see 21912)
return this.statement;
}
/**
* Code generation for labeled statement
*
* may not need actual source positions recording
*
* @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
* @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
*/
public void generateCode(BlockScope currentScope, CodeStream codeStream) {
if ((this.bits & IsReachable) == 0) {
return;
}
int pc = codeStream.position;
if (this.targetLabel != null) {
this.targetLabel.initialize(codeStream);
if (this.statement != null) {
this.statement.generateCode(currentScope, codeStream);
}
this.targetLabel.place();
}
// May loose some local variable initializations : affecting the local variable attributes
if (this.mergedInitStateIndex != -1) {
codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex);
codeStream.addDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex);
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
public StringBuffer printStatement(int tab, StringBuffer output) {
printIndent(tab, output).append(this.label).append(": "); //$NON-NLS-1$
if (this.statement == null)
output.append(';');
else
this.statement.printStatement(0, output);
return output;
}
public void resolve(BlockScope scope) {
if (this.statement != null) {
this.statement.resolve(scope);
}
}
public void traverse(
ASTVisitor visitor,
BlockScope blockScope) {
if (visitor.visit(this, blockScope)) {
if (this.statement != null) this.statement.traverse(visitor, blockScope);
}
visitor.endVisit(this, blockScope);
}
}