| /* |
| * Copyright 2003-2012 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.assignment; |
| |
| import com.intellij.codeInsight.NullableNotNullManager; |
| import com.intellij.codeInsight.intention.AddAnnotationPsiFix; |
| import com.intellij.codeInspection.ui.SingleCheckboxOptionsPanel; |
| import com.intellij.psi.*; |
| import com.siyeh.InspectionGadgetsBundle; |
| import com.siyeh.ig.BaseInspection; |
| import com.siyeh.ig.BaseInspectionVisitor; |
| import com.siyeh.ig.DelegatingFix; |
| import com.siyeh.ig.InspectionGadgetsFix; |
| import com.siyeh.ig.psiutils.ParenthesesUtils; |
| import org.jetbrains.annotations.NotNull; |
| |
| import javax.swing.*; |
| |
| public class AssignmentToNullInspection extends BaseInspection { |
| |
| @SuppressWarnings("PublicField") |
| public boolean ignoreAssignmentsToFields = false; |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message("assignment.to.null.display.name"); |
| } |
| |
| @Override |
| @NotNull |
| public String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message( |
| "assignment.to.null.problem.descriptor"); |
| } |
| |
| @Override |
| protected InspectionGadgetsFix buildFix(Object... infos) { |
| final Object info = infos[0]; |
| if (!(info instanceof PsiReferenceExpression)) { |
| return null; |
| } |
| final PsiElement target = ((PsiReferenceExpression)info).resolve(); |
| if (!(target instanceof PsiVariable)) { |
| return null; |
| } |
| final NullableNotNullManager manager = NullableNotNullManager.getInstance(target.getProject()); |
| return new DelegatingFix(new AddAnnotationPsiFix(manager.getDefaultNullable(), (PsiVariable)target,PsiNameValuePair.EMPTY_ARRAY)); |
| } |
| |
| @Override |
| public JComponent createOptionsPanel() { |
| return new SingleCheckboxOptionsPanel(InspectionGadgetsBundle.message( |
| "assignment.to.null.option"), this, |
| "ignoreAssignmentsToFields"); |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new AssignmentToNullVisitor(); |
| } |
| |
| private class AssignmentToNullVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitLiteralExpression( |
| @NotNull PsiLiteralExpression value) { |
| super.visitLiteralExpression(value); |
| final String text = value.getText(); |
| if (!PsiKeyword.NULL.equals(text)) { |
| return; |
| } |
| PsiElement parent = value.getParent(); |
| while (parent instanceof PsiParenthesizedExpression || |
| parent instanceof PsiConditionalExpression || |
| parent instanceof PsiTypeCastExpression) { |
| parent = parent.getParent(); |
| } |
| if (!(parent instanceof PsiAssignmentExpression)) { |
| return; |
| } |
| final PsiAssignmentExpression assignmentExpression = |
| (PsiAssignmentExpression)parent; |
| final PsiExpression lhs = ParenthesesUtils.stripParentheses( |
| assignmentExpression.getLExpression()); |
| if (lhs == null || isReferenceToNullableVariable(lhs)) { |
| return; |
| } |
| registerError(lhs, lhs); |
| } |
| |
| private boolean isReferenceToNullableVariable( |
| PsiExpression lhs) { |
| if (!(lhs instanceof PsiReferenceExpression)) { |
| return false; |
| } |
| final PsiReferenceExpression referenceExpression = |
| (PsiReferenceExpression)lhs; |
| final PsiElement element = referenceExpression.resolve(); |
| if (!(element instanceof PsiVariable)) { |
| return false; |
| } |
| final PsiVariable variable = (PsiVariable)element; |
| if (ignoreAssignmentsToFields && variable instanceof PsiField) { |
| return true; |
| } |
| return NullableNotNullManager.isNullable(variable); |
| } |
| } |
| } |