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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.codegen.CodeStream;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.lookup.*;
public class BreakStatement extends BranchStatement {
public Expression expression;
public SwitchExpression switchExpression;
public boolean isImplicit;
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);
if (targetContext == null) {
if (this.label == null) {
currentScope.problemReporter().invalidBreak(this);
} else {
if (this.switchExpression == null)
currentScope.problemReporter().undefinedLabel(this);
}
return flowInfo; // pretend it did not break since no actual target
}
if (this.switchExpression != null && this.expression != null) {
flowInfo = this.expression.analyseCode(currentScope, flowContext, flowInfo);
this.expression.checkNPEbyUnboxing(currentScope, flowContext, flowInfo);
if (flowInfo.reachMode() == FlowInfo.REACHABLE && currentScope.compilerOptions().isAnnotationBasedNullAnalysisEnabled)
checkAgainstNullAnnotation(currentScope, flowContext, flowInfo, this.expression);
}
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
protected void generateExpressionResultCode(BlockScope currentScope, CodeStream codeStream) {
if (this.label == null && this.expression != null) {
this.expression.generateCode(currentScope, codeStream, this.switchExpression != null);
}
}
@Override
protected void adjustStackSize(BlockScope currentScope, CodeStream codeStream) {
if (this.label == null && this.expression != null && this.switchExpression != null) {
TypeBinding postConversionType = this.expression.postConversionType(currentScope);
switch(postConversionType.id) {
case TypeIds.T_long :
case TypeIds.T_double :
codeStream.decrStackSize(2);
break;
case TypeIds.T_void :
break;
default :
codeStream.decrStackSize(1);
break;
}
}
}
@Override
public void resolve(BlockScope scope) {
super.resolve(scope);
if (this.expression != null && (this.switchExpression != null || this.isImplicit)) {
if (this.switchExpression == null && this.isImplicit && !this.expression.statementExpression()) {
if (scope.compilerOptions().enablePreviewFeatures) {
/* JLS 12 14.11.2
Switch labeled rules in switch statements differ from those in switch expressions (15.28).
In switch statements they must be switch labeled statement expressions, ... */
scope.problemReporter().invalidExpressionAsStatement(this.expression);
return;
}
}
this.expression.resolveType(scope);
} else if (this.expression == null && this.switchExpression != null) {
scope.problemReporter().switchExpressionBreakMissingValue(this);
}
}
@Override
public TypeBinding resolveExpressionType(BlockScope scope) {
return this.expression != null ? this.expression.resolveType(scope) : null;
}
@Override
public StringBuffer printStatement(int tab, StringBuffer output) {
if (!this.isImplicit) // implicit for SwitchLabeledExpressions
printIndent(tab, output).append("break"); //$NON-NLS-1$
if (this.label != null)
output.append(' ').append(this.label);
if (this.expression != null) {
output.append(' ');
this.expression.printExpression(tab, output);
}
return output.append(';');
}
@Override
public void traverse(ASTVisitor visitor, BlockScope blockscope) {
if (visitor.visit(this, blockscope)) {
if (this.expression != null)
this.expression.traverse(visitor, blockscope);
}
visitor.endVisit(this, blockscope);
}
@Override
public boolean doesNotCompleteNormally() {
return true;
}
}
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