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/*
* Copyright 2003-2014 Dave Griffith, Bas Leijdekkers
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.siyeh.ig.initialization;
import com.intellij.psi.*;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.util.PsiTreeUtil;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.psiutils.ExpressionUtils;
import com.siyeh.ig.psiutils.VariableAccessUtils;
import org.jetbrains.annotations.NotNull;
public class NonThreadSafeLazyInitializationInspectionBase extends BaseInspection {
@Override
@NotNull
public String getDisplayName() {
return InspectionGadgetsBundle.message(
"non.thread.safe.lazy.initialization.display.name");
}
@Override
@NotNull
public String buildErrorString(Object... infos) {
return InspectionGadgetsBundle.message(
"non.thread.safe.lazy.initialization.problem.descriptor");
}
@Override
public BaseInspectionVisitor buildVisitor() {
return new UnsafeSafeLazyInitializationVisitor();
}
private static class UnsafeSafeLazyInitializationVisitor
extends BaseInspectionVisitor {
@Override
public void visitAssignmentExpression(
@NotNull PsiAssignmentExpression expression) {
super.visitAssignmentExpression(expression);
final PsiExpression lhs = expression.getLExpression();
if (!(lhs instanceof PsiReferenceExpression)) {
return;
}
final PsiReferenceExpression reference = (PsiReferenceExpression)lhs;
final PsiElement referent = reference.resolve();
if (!(referent instanceof PsiField)) {
return;
}
final PsiField field = (PsiField)referent;
if (!field.hasModifierProperty(PsiModifier.STATIC)) {
return;
}
if (isInStaticInitializer(expression)) {
return;
}
if (isInSynchronizedContext(expression)) {
return;
}
final PsiStatement statement = PsiTreeUtil.getParentOfType(expression, PsiStatement.class);
final PsiElement parent =
PsiTreeUtil.skipParentsOfType(statement, PsiCodeBlock.class, PsiBlockStatement.class);
if (!(parent instanceof PsiIfStatement)) {
return;
}
final PsiIfStatement ifStatement = (PsiIfStatement)parent;
final PsiExpression condition = ifStatement.getCondition();
if (condition == null|| !isNullComparison(condition, field)) {
return;
}
registerError(lhs, ifStatement, field);
}
private static boolean isNullComparison(PsiExpression condition, PsiVariable variable) {
if (!(condition instanceof PsiBinaryExpression)) {
return false;
}
final PsiBinaryExpression comparison = (PsiBinaryExpression)condition;
final IElementType tokenType = comparison.getOperationTokenType();
if (!tokenType.equals(JavaTokenType.EQEQ)) {
return false;
}
final PsiExpression lhs = comparison.getLOperand();
final PsiExpression rhs = comparison.getROperand();
if (ExpressionUtils.isNullLiteral(rhs)) {
return VariableAccessUtils.evaluatesToVariable(lhs, variable);
}
else if (ExpressionUtils.isNullLiteral(lhs)) {
return VariableAccessUtils.evaluatesToVariable(rhs, variable);
}
return false;
}
private static boolean isInSynchronizedContext(PsiElement element) {
final PsiSynchronizedStatement syncBlock =
PsiTreeUtil.getParentOfType(element,
PsiSynchronizedStatement.class);
if (syncBlock != null) {
return true;
}
final PsiMethod method =
PsiTreeUtil.getParentOfType(element,
PsiMethod.class);
return method != null &&
method.hasModifierProperty(PsiModifier.SYNCHRONIZED)
&& method.hasModifierProperty(PsiModifier.STATIC);
}
private static boolean isInStaticInitializer(PsiElement element) {
final PsiClassInitializer initializer =
PsiTreeUtil.getParentOfType(element,
PsiClassInitializer.class);
return initializer != null &&
initializer.hasModifierProperty(PsiModifier.STATIC);
}
}
}
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