| /* |
| * 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.codeInspection.ProblemDescriptor; |
| import com.intellij.codeInspection.ui.SingleCheckboxOptionsPanel; |
| import com.intellij.openapi.project.Project; |
| import com.intellij.psi.*; |
| import com.intellij.psi.tree.IElementType; |
| import com.intellij.psi.util.ConstantExpressionUtil; |
| import com.intellij.util.IncorrectOperationException; |
| import com.siyeh.InspectionGadgetsBundle; |
| import com.siyeh.ig.BaseInspection; |
| import com.siyeh.ig.BaseInspectionVisitor; |
| import com.siyeh.ig.InspectionGadgetsFix; |
| import com.siyeh.ig.PsiReplacementUtil; |
| import com.siyeh.ig.psiutils.EquivalenceChecker; |
| import com.siyeh.ig.psiutils.ExpressionUtils; |
| import gnu.trove.THashSet; |
| import org.jetbrains.annotations.NonNls; |
| import org.jetbrains.annotations.NotNull; |
| |
| import javax.swing.*; |
| import java.util.Set; |
| |
| public class PointlessArithmeticExpressionInspection |
| extends BaseInspection { |
| |
| private static final Set<IElementType> arithmeticTokens = |
| new THashSet<IElementType>(9); |
| |
| static { |
| arithmeticTokens.add(JavaTokenType.PLUS); |
| arithmeticTokens.add(JavaTokenType.MINUS); |
| arithmeticTokens.add(JavaTokenType.ASTERISK); |
| arithmeticTokens.add(JavaTokenType.DIV); |
| arithmeticTokens.add(JavaTokenType.PERC); |
| arithmeticTokens.add(JavaTokenType.GT); |
| arithmeticTokens.add(JavaTokenType.LT); |
| arithmeticTokens.add(JavaTokenType.LE); |
| arithmeticTokens.add(JavaTokenType.GE); |
| } |
| |
| /** |
| * @noinspection PublicField |
| */ |
| public boolean m_ignoreExpressionsContainingConstants = true; |
| |
| @Override |
| public JComponent createOptionsPanel() { |
| return new SingleCheckboxOptionsPanel( |
| InspectionGadgetsBundle.message( |
| "pointless.boolean.expression.ignore.option"), |
| this, "m_ignoreExpressionsContainingConstants"); |
| } |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message( |
| "pointless.arithmetic.expression.display.name"); |
| } |
| |
| @Override |
| public boolean isEnabledByDefault() { |
| return true; |
| } |
| |
| @Override |
| @NotNull |
| public String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message( |
| "expression.can.be.replaced.problem.descriptor", |
| calculateReplacementExpression((PsiExpression)infos[0])); |
| } |
| |
| @NonNls |
| String calculateReplacementExpression(PsiExpression expression) { |
| final PsiBinaryExpression exp = (PsiBinaryExpression)expression; |
| final PsiExpression lhs = exp.getLOperand(); |
| final PsiExpression rhs = exp.getROperand(); |
| assert rhs != null; |
| final IElementType tokenType = exp.getOperationTokenType(); |
| if (tokenType.equals(JavaTokenType.PLUS)) { |
| if (isZero(lhs)) { |
| return rhs.getText(); |
| } |
| else { |
| return lhs.getText(); |
| } |
| } |
| else if (tokenType.equals(JavaTokenType.MINUS)) { |
| if (isZero(rhs)) { |
| return lhs.getText(); |
| } |
| return "0"; |
| } |
| else if (tokenType.equals(JavaTokenType.ASTERISK)) { |
| if (isOne(lhs)) { |
| return rhs.getText(); |
| } |
| else if (isOne(rhs)) { |
| return lhs.getText(); |
| } |
| else { |
| return "0"; |
| } |
| } |
| else if (tokenType.equals(JavaTokenType.DIV)) { |
| if (ExpressionUtils.isOne(rhs)) { |
| return lhs.getText(); |
| } |
| return "1"; |
| } |
| else if (tokenType.equals(JavaTokenType.PERC)) { |
| return "0"; |
| } |
| else if (tokenType.equals(JavaTokenType.LE) || |
| tokenType.equals(JavaTokenType.GE)) { |
| return "true"; |
| } |
| else if (tokenType.equals(JavaTokenType.LT) || |
| tokenType.equals(JavaTokenType.GT)) { |
| return "false"; |
| } |
| else { |
| return ""; |
| } |
| } |
| |
| @Override |
| public InspectionGadgetsFix buildFix(Object... infos) { |
| return new PointlessArithmeticFix(); |
| } |
| |
| private class PointlessArithmeticFix extends InspectionGadgetsFix { |
| @Override |
| @NotNull |
| public String getFamilyName() { |
| return getName(); |
| } |
| |
| @Override |
| @NotNull |
| public String getName() { |
| return InspectionGadgetsBundle.message( |
| "constant.conditional.expression.simplify.quickfix"); |
| } |
| |
| @Override |
| public void doFix(Project project, ProblemDescriptor descriptor) |
| throws IncorrectOperationException { |
| final PsiExpression expression = |
| (PsiExpression)descriptor.getPsiElement(); |
| final String newExpression = |
| calculateReplacementExpression(expression); |
| PsiReplacementUtil.replaceExpression(expression, newExpression); |
| } |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new PointlessArithmeticVisitor(); |
| } |
| |
| private class PointlessArithmeticVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitBinaryExpression( |
| @NotNull PsiBinaryExpression expression) { |
| super.visitBinaryExpression(expression); |
| final PsiExpression rhs = expression.getROperand(); |
| if (rhs == null) { |
| return; |
| } |
| final PsiType expressionType = expression.getType(); |
| if (PsiType.DOUBLE.equals(expressionType) || |
| PsiType.FLOAT.equals(expressionType)) { |
| return; |
| } |
| if (!arithmeticTokens.contains(expression.getOperationTokenType())) { |
| return; |
| } |
| if (ExpressionUtils.hasStringType(expression)) { |
| return; |
| } |
| final PsiExpression lhs = expression.getLOperand(); |
| final IElementType tokenType = expression.getOperationTokenType(); |
| final boolean isPointless; |
| if (tokenType.equals(JavaTokenType.PLUS)) { |
| isPointless = additionExpressionIsPointless(lhs, rhs); |
| } |
| else if (tokenType.equals(JavaTokenType.MINUS)) { |
| isPointless = subtractionExpressionIsPointless(lhs, rhs); |
| } |
| else if (tokenType.equals(JavaTokenType.ASTERISK)) { |
| isPointless = multiplyExpressionIsPointless(lhs, rhs); |
| } |
| else if (tokenType.equals(JavaTokenType.DIV)) { |
| isPointless = divideExpressionIsPointless(lhs, rhs); |
| } |
| else if (tokenType.equals(JavaTokenType.PERC)) { |
| isPointless = modExpressionIsPointless(lhs, rhs); |
| } |
| else if (tokenType.equals(JavaTokenType.LE) || |
| tokenType.equals(JavaTokenType.GE) || |
| tokenType.equals(JavaTokenType.GT) || |
| tokenType.equals(JavaTokenType.LT)) { |
| isPointless = comparisonExpressionIsPointless(lhs, rhs, |
| tokenType); |
| } |
| else { |
| isPointless = false; |
| } |
| if (!isPointless) { |
| return; |
| } |
| if (!PsiType.BOOLEAN.equals(expressionType)) { |
| if (expressionType == null || |
| !expressionType.equals(rhs.getType()) || |
| !expressionType.equals(lhs.getType())) { |
| // A bit rude way to avoid false positive of |
| // 'int sum = 5, n = 6; float p = (1.0f * sum) / n;' |
| return; |
| } |
| } |
| registerError(expression, expression); |
| } |
| |
| private boolean subtractionExpressionIsPointless(PsiExpression lhs, PsiExpression rhs) { |
| if (PsiType.INT.equals(lhs.getType()) && EquivalenceChecker.expressionsAreEquivalent(lhs, rhs)) { |
| return true; |
| } |
| return isZero(rhs); |
| } |
| |
| private boolean additionExpressionIsPointless(PsiExpression lhs, PsiExpression rhs) { |
| return isZero(lhs) || isZero(rhs); |
| } |
| |
| private boolean multiplyExpressionIsPointless(PsiExpression lhs, PsiExpression rhs) { |
| return isZero(lhs) || isZero(rhs) || isOne(lhs) || isOne(rhs); |
| } |
| |
| private boolean divideExpressionIsPointless(PsiExpression lhs, PsiExpression rhs) { |
| if (PsiType.INT.equals(lhs.getType()) && EquivalenceChecker.expressionsAreEquivalent(lhs, rhs)) { |
| return true; |
| } |
| return isOne(rhs); |
| } |
| |
| private boolean modExpressionIsPointless(PsiExpression lhs, PsiExpression rhs) { |
| if (PsiType.INT.equals(lhs.getType()) && EquivalenceChecker.expressionsAreEquivalent(lhs, rhs)) { |
| return true; |
| } |
| return PsiType.INT.equals(rhs.getType()) && isOne(rhs); |
| } |
| |
| private boolean comparisonExpressionIsPointless( |
| PsiExpression lhs, PsiExpression rhs, IElementType comparison) { |
| if (PsiType.INT.equals(lhs.getType()) && |
| PsiType.INT.equals(rhs.getType())) { |
| return intComparisonIsPointless(lhs, rhs, comparison); |
| } |
| else if (PsiType.LONG.equals(lhs.getType()) && |
| PsiType.LONG.equals(rhs.getType())) { |
| return longComparisonIsPointless(lhs, rhs, comparison); |
| } |
| return false; |
| } |
| |
| private boolean intComparisonIsPointless( |
| PsiExpression lhs, PsiExpression rhs, IElementType comparison) { |
| if (isMaxInt(lhs) || isMinInt(rhs)) { |
| return JavaTokenType.GE.equals(comparison) || |
| JavaTokenType.LT.equals(comparison); |
| } |
| if (isMinInt(lhs) || isMaxInt(rhs)) { |
| return JavaTokenType.LE.equals(comparison) || |
| JavaTokenType.GT.equals(comparison); |
| } |
| return false; |
| } |
| |
| private boolean longComparisonIsPointless( |
| PsiExpression lhs, PsiExpression rhs, IElementType comparison) { |
| if (isMaxLong(lhs) || isMinLong(rhs)) { |
| return JavaTokenType.GE.equals(comparison) || |
| JavaTokenType.LT.equals(comparison); |
| } |
| if (isMinLong(lhs) || isMaxLong(rhs)) { |
| return JavaTokenType.LE.equals(comparison) || |
| JavaTokenType.GT.equals(comparison); |
| } |
| return false; |
| } |
| } |
| |
| boolean isZero(PsiExpression expression) { |
| if (m_ignoreExpressionsContainingConstants && |
| !(expression instanceof PsiLiteralExpression)) { |
| return false; |
| } |
| return ExpressionUtils.isZero(expression); |
| } |
| |
| boolean isOne(PsiExpression expression) { |
| if (m_ignoreExpressionsContainingConstants && |
| !(expression instanceof PsiLiteralExpression)) { |
| return false; |
| } |
| return ExpressionUtils.isOne(expression); |
| } |
| |
| private static boolean isMinDouble(PsiExpression expression) { |
| final Double value = (Double) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.DOUBLE); |
| return value != null && value.doubleValue() == Double.MIN_VALUE; |
| } |
| |
| private static boolean isMaxDouble(PsiExpression expression) { |
| final Double value = (Double) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.DOUBLE); |
| //noinspection FloatingPointEquality |
| return value != null && value.doubleValue() == Double.MAX_VALUE; |
| } |
| |
| private static boolean isMinFloat(PsiExpression expression) { |
| final Float value = (Float) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.FLOAT); |
| //noinspection FloatingPointEquality |
| return value != null && value.floatValue() == Float.MIN_VALUE; |
| } |
| |
| private static boolean isMaxFloat(PsiExpression expression) { |
| final Float value = (Float) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.FLOAT); |
| //noinspection FloatingPointEquality |
| return value != null && value.floatValue() == Float.MAX_VALUE; |
| } |
| |
| private static boolean isMinInt(PsiExpression expression) { |
| final Integer value = (Integer) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.INT); |
| return value != null && value.intValue() == Integer.MIN_VALUE; |
| } |
| |
| private static boolean isMaxInt(PsiExpression expression) { |
| final Integer value = (Integer) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.INT); |
| return value != null && value.intValue() == Integer.MAX_VALUE; |
| } |
| |
| private static boolean isMinLong(PsiExpression expression) { |
| final Long value = (Long) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.LONG); |
| return value != null && value.longValue() == Long.MIN_VALUE; |
| } |
| |
| private static boolean isMaxLong(PsiExpression expression) { |
| final Long value = (Long) |
| ConstantExpressionUtil.computeCastTo( |
| expression, PsiType.LONG); |
| return value != null && value.longValue() == Long.MAX_VALUE; |
| } |
| } |
