| /* |
| * Copyright 2003-2013 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.numeric; |
| |
| import com.intellij.psi.*; |
| import com.intellij.psi.tree.IElementType; |
| import com.intellij.psi.util.ConstantExpressionUtil; |
| import com.siyeh.InspectionGadgetsBundle; |
| import com.siyeh.ig.BaseInspection; |
| import com.siyeh.ig.BaseInspectionVisitor; |
| import org.jetbrains.annotations.NotNull; |
| |
| public class DivideByZeroInspection extends BaseInspection { |
| |
| @Override |
| @NotNull |
| public String getID() { |
| return "divzero"; |
| } |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message("divide.by.zero.display.name"); |
| } |
| |
| @Override |
| @NotNull |
| protected String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message("divide.by.zero.problem.descriptor"); |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new DivisionByZeroVisitor(); |
| } |
| |
| private static class DivisionByZeroVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitPolyadicExpression(PsiPolyadicExpression expression) { |
| super.visitPolyadicExpression(expression); |
| final IElementType tokenType = expression.getOperationTokenType(); |
| if (!JavaTokenType.DIV.equals(tokenType) && !JavaTokenType.PERC.equals(tokenType)) { |
| return; |
| } |
| final PsiExpression[] operands = expression.getOperands(); |
| for (int i = 1; i < operands.length; i++) { |
| final PsiExpression operand = operands[i]; |
| if (isZero(operand)) { |
| registerError(operand); |
| return; |
| } |
| } |
| } |
| |
| @Override |
| public void visitAssignmentExpression(PsiAssignmentExpression expression) { |
| super.visitAssignmentExpression(expression); |
| final PsiExpression rhs = expression.getRExpression(); |
| if (rhs == null) { |
| return; |
| } |
| final IElementType tokenType = expression.getOperationTokenType(); |
| if (!tokenType.equals(JavaTokenType.DIVEQ) && !tokenType.equals(JavaTokenType.PERCEQ) || !isZero(rhs)) { |
| return; |
| } |
| registerError(expression); |
| } |
| |
| private static boolean isZero(PsiExpression expression) { |
| final Object value = ConstantExpressionUtil.computeCastTo(expression, PsiType.DOUBLE); |
| if (!(value instanceof Double)) { |
| return false; |
| } |
| final double constantValue = ((Double)value).doubleValue(); |
| return constantValue == 0.0 || constantValue == -0.0; |
| } |
| } |
| } |