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/*
* Copyright 2000-2013 JetBrains s.r.o.
*
* 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.ipp.asserttoif;
import com.intellij.codeInsight.AnnotationUtil;
import com.intellij.codeInsight.NullableNotNullManager;
import com.intellij.psi.*;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.psi.util.PsiUtil;
import com.siyeh.ig.PsiReplacementUtil;
import com.siyeh.ig.psiutils.ParenthesesUtils;
import com.siyeh.ig.psiutils.VariableAccessUtils;
import com.siyeh.ipp.base.Intention;
import com.siyeh.ipp.base.PsiElementPredicate;
import org.jetbrains.annotations.NotNull;
import java.util.List;
/**
* @author Bas Leijdekkers
*/
public class ObjectsRequireNonNullIntention extends Intention {
@NotNull
@Override
protected PsiElementPredicate getElementPredicate() {
return new NullCheckedAssignmentPredicate();
}
@Override
protected void processIntention(@NotNull PsiElement element) {
if (!(element instanceof PsiReferenceExpression)) {
return;
}
final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)element;
final PsiElement target = referenceExpression.resolve();
if (!(target instanceof PsiVariable)) {
return;
}
final PsiVariable variable = (PsiVariable)target;
final List<String> notNulls = NullableNotNullManager.getInstance(element.getProject()).getNotNulls();
final PsiAnnotation annotation = AnnotationUtil.findAnnotation(variable, notNulls);
if (annotation != null) {
annotation.delete();
} else {
final PsiStatement referenceStatement = PsiTreeUtil.getParentOfType(referenceExpression, PsiStatement.class);
final PsiElement parent = referenceStatement.getParent();
if (!(parent instanceof PsiCodeBlock)) {
return;
}
final PsiCodeBlock codeBlock = (PsiCodeBlock)parent;
final PsiStatement[] statements = codeBlock.getStatements();
PsiStatement statementToDelete = null;
for (PsiStatement statement : statements) {
if (statement == referenceStatement) {
break;
}
if (NullCheckedAssignmentPredicate.isNotNullAssertion(statement, variable) ||
NullCheckedAssignmentPredicate.isIfStatementNullCheck(statement, variable)) {
statementToDelete = statement;
break;
}
}
if (statementToDelete == null) {
return;
}
statementToDelete.delete();
}
PsiReplacementUtil
.replaceExpressionAndShorten(referenceExpression, "java.util.Objects.requireNonNull(" + referenceExpression.getText() + ")");
}
private static class NullCheckedAssignmentPredicate implements PsiElementPredicate {
@Override
public boolean satisfiedBy(PsiElement element) {
if (!PsiUtil.isLanguageLevel7OrHigher(element)) {
return false;
}
if (!(element instanceof PsiReferenceExpression)) {
return false;
}
final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)element;
if (PsiUtil.isAccessedForWriting(referenceExpression)) {
return false;
}
final PsiElement target = referenceExpression.resolve();
if (!(target instanceof PsiVariable)) {
return false;
}
final PsiVariable variable = (PsiVariable)target;
if (NullableNotNullManager.isNotNull(variable)) {
return true;
}
final PsiStatement referenceStatement = PsiTreeUtil.getParentOfType(referenceExpression, PsiStatement.class);
final PsiElement parent = referenceStatement != null ? referenceStatement.getParent() : null;
if (!(parent instanceof PsiCodeBlock)) {
return false;
}
final PsiCodeBlock codeBlock = (PsiCodeBlock)parent;
final PsiStatement[] statements = codeBlock.getStatements();
for (PsiStatement statement : statements) {
if (statement == referenceStatement) {
return false;
}
if (isNotNullAssertion(statement, variable) || isIfStatementNullCheck(statement, variable)) {
return true;
}
}
return false;
}
private static boolean isIfStatementNullCheck(PsiStatement statement, @NotNull PsiVariable variable) {
if (!(statement instanceof PsiIfStatement)) {
return false;
}
final PsiIfStatement ifStatement = (PsiIfStatement)statement;
final PsiStatement elseBranch = ifStatement.getElseBranch();
if (elseBranch != null) {
return false;
}
final PsiStatement thenBranch = ifStatement.getThenBranch();
if (!IfStatementPredicate.isSimpleThrowStatement(thenBranch)) {
return false;
}
final PsiExpression condition = ifStatement.getCondition();
return isNullComparison(condition, variable, true);
}
private static boolean isNotNullAssertion(PsiStatement statement, @NotNull PsiVariable variable) {
if (!(statement instanceof PsiAssertStatement)) {
return false;
}
final PsiAssertStatement assertStatement = (PsiAssertStatement)statement;
final PsiExpression condition = assertStatement.getAssertCondition();
return isNullComparison(condition, variable, false);
}
private static boolean isNullComparison(PsiExpression expression, @NotNull PsiVariable variable, boolean equal) {
expression = ParenthesesUtils.stripParentheses(expression);
if (!(expression instanceof PsiBinaryExpression)) {
return false;
}
final PsiBinaryExpression binaryExpression = (PsiBinaryExpression)expression;
final IElementType tokenType = binaryExpression.getOperationTokenType();
if (equal) {
if (!JavaTokenType.EQEQ.equals(tokenType)) {
return false;
}
}
else {
if (!JavaTokenType.NE.equals(tokenType)) {
return false;
}
}
final PsiExpression lhs = binaryExpression.getLOperand();
final PsiExpression rhs = binaryExpression.getROperand();
if (rhs == null) {
return false;
}
return PsiType.NULL.equals(rhs.getType()) && VariableAccessUtils.evaluatesToVariable(lhs, variable) ||
PsiType.NULL.equals(lhs.getType()) && VariableAccessUtils.evaluatesToVariable(rhs, variable);
}
}
}
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