org.eclipse.jdt.internal.compiler.ast.BreakStatement.java Source code

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Here is the source code for org.eclipse.jdt.internal.compiler.ast.BreakStatement.java

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/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * 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"
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.lookup.*;

public class BreakStatement extends BranchStatement {

    public BreakStatement(char[] label, int sourceStart, int e) {
        super(label, sourceStart, e);
    }

    @Override
    public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {

        // here requires to generate a sequence of finally blocks invocations depending corresponding
        // to each of the traversed try statements, so that execution will terminate properly.

        // lookup the label, this should answer the returnContext
        FlowContext targetContext = (this.label == null) ? flowContext.getTargetContextForDefaultBreak()
                : flowContext.getTargetContextForBreakLabel(this.label);

        // JLS 13 14.15
        if (targetContext instanceof SwitchFlowContext
                && targetContext.associatedNode instanceof SwitchExpression) {
            currentScope.problemReporter().switchExpressionBreakNotAllowed(this);
        }
        if (targetContext == null) {
            if (this.label == null) {
                currentScope.problemReporter().invalidBreak(this);
            } else {
                currentScope.problemReporter().undefinedLabel(this);
            }
            return flowInfo; // pretend it did not break since no actual target
        }

        targetContext.recordAbruptExit();
        targetContext.expireNullCheckedFieldInfo();

        this.initStateIndex = currentScope.methodScope().recordInitializationStates(flowInfo);

        this.targetLabel = targetContext.breakLabel();
        FlowContext traversedContext = flowContext;
        int subCount = 0;
        this.subroutines = new SubRoutineStatement[5];

        do {
            SubRoutineStatement sub;
            if ((sub = traversedContext.subroutine()) != null) {
                if (subCount == this.subroutines.length) {
                    System.arraycopy(this.subroutines, 0,
                            (this.subroutines = new SubRoutineStatement[subCount * 2]), 0, subCount); // grow
                }
                this.subroutines[subCount++] = sub;
                if (sub.isSubRoutineEscaping()) {
                    break;
                }
            }
            traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
            traversedContext.recordBreakTo(targetContext);

            if (traversedContext instanceof InsideSubRoutineFlowContext) {
                ASTNode node = traversedContext.associatedNode;
                if (node instanceof TryStatement) {
                    TryStatement tryStatement = (TryStatement) node;
                    flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
                }
            } else if (traversedContext == targetContext) {
                // only record break info once accumulated through subroutines, and only against target context
                targetContext.recordBreakFrom(flowInfo);
                break;
            }
        } while ((traversedContext = traversedContext.getLocalParent()) != null);

        // resize subroutines
        if (subCount != this.subroutines.length) {
            System.arraycopy(this.subroutines, 0, (this.subroutines = new SubRoutineStatement[subCount]), 0,
                    subCount);
        }
        return FlowInfo.DEAD_END;
    }

    @Override
    public StringBuffer printStatement(int tab, StringBuffer output) {
        printIndent(tab, output).append("break"); //$NON-NLS-1$
        if (this.label != null)
            output.append(' ').append(this.label);
        return output.append(';');
    }

    @Override
    public void traverse(ASTVisitor visitor, BlockScope blockscope) {
        visitor.visit(this, blockscope);
        visitor.endVisit(this, blockscope);
    }

    @Override
    public boolean doesNotCompleteNormally() {
        return true;
    }
}