| /* |
| * 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.bitwise; |
| |
| 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.psi.util.PsiUtilCore; |
| 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 org.jetbrains.annotations.NonNls; |
| import org.jetbrains.annotations.NotNull; |
| |
| import javax.swing.*; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| public class PointlessBitwiseExpressionInspection extends BaseInspection { |
| |
| /** |
| * @noinspection PublicField |
| */ |
| public boolean m_ignoreExpressionsContainingConstants = false; |
| |
| static final Set<IElementType> bitwiseTokens = |
| new HashSet<IElementType>(6); |
| |
| static { |
| bitwiseTokens.add(JavaTokenType.AND); |
| bitwiseTokens.add(JavaTokenType.OR); |
| bitwiseTokens.add(JavaTokenType.XOR); |
| bitwiseTokens.add(JavaTokenType.LTLT); |
| bitwiseTokens.add(JavaTokenType.GTGT); |
| bitwiseTokens.add(JavaTokenType.GTGTGT); |
| } |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message( |
| "pointless.bitwise.expression.display.name"); |
| } |
| |
| @Override |
| @NotNull |
| public String buildErrorString(Object... infos) { |
| final PsiPolyadicExpression polyadicExpression = |
| (PsiPolyadicExpression)infos[0]; |
| final String replacementExpression = |
| calculateReplacementExpression(polyadicExpression); |
| return InspectionGadgetsBundle.message( |
| "expression.can.be.replaced.problem.descriptor", |
| replacementExpression); |
| } |
| |
| @Override |
| public boolean isEnabledByDefault() { |
| return true; |
| } |
| |
| @Override |
| public JComponent createOptionsPanel() { |
| return new SingleCheckboxOptionsPanel(InspectionGadgetsBundle.message("pointless.boolean.expression.ignore.option"), |
| this, "m_ignoreExpressionsContainingConstants"); |
| } |
| |
| @NonNls |
| String calculateReplacementExpression(PsiPolyadicExpression expression) { |
| final IElementType tokenType = expression.getOperationTokenType(); |
| final PsiExpression[] operands = expression.getOperands(); |
| PsiExpression previousOperand = null; |
| for (int i = 0, length = operands.length; i < length; i++) { |
| final PsiExpression operand = operands[i]; |
| if (isZero(operand)) { |
| if (tokenType.equals(JavaTokenType.AND) || |
| (tokenType.equals(JavaTokenType.LTLT) || tokenType.equals(JavaTokenType.GTGT) || tokenType.equals(JavaTokenType.GTGTGT)) && |
| previousOperand == null) { |
| return getText(expression, operands[0], operands[length - 1], PsiType.LONG.equals(expression.getType()) ? "0L" : "0"); |
| } |
| else if (tokenType.equals(JavaTokenType.OR) || tokenType.equals(JavaTokenType.XOR) || |
| (tokenType.equals(JavaTokenType.LTLT) || tokenType.equals(JavaTokenType.GTGT) || tokenType.equals(JavaTokenType.GTGTGT)) && |
| previousOperand != null) { |
| return getText(expression, i == length - 1 ? expression.getTokenBeforeOperand(operand) : operand); |
| } |
| } |
| else if (isAllOnes(operand)) { |
| if (tokenType.equals(JavaTokenType.AND)) { |
| return getText(expression, i == length - 1 ? expression.getTokenBeforeOperand(operand) : operand); |
| } |
| if (tokenType.equals(JavaTokenType.OR)) { |
| return operand.getText(); |
| } |
| else if (tokenType.equals(JavaTokenType.XOR)) { |
| if (previousOperand != null) { |
| return getText(expression, previousOperand, operand, "~" + previousOperand.getText()); |
| } |
| else { |
| final PsiExpression nextOperand = operands[i + 1]; |
| return getText(expression, operand, nextOperand, "~" + nextOperand.getText()); |
| } |
| } |
| } |
| else if (EquivalenceChecker.expressionsAreEquivalent(previousOperand, operand)) { |
| if (tokenType.equals(JavaTokenType.OR) || tokenType.equals(JavaTokenType.AND)) { |
| return getText(expression, previousOperand, operand, operand.getText()); |
| } |
| else if (tokenType.equals(JavaTokenType.XOR)) { |
| return getText(expression, previousOperand, operand, PsiType.LONG.equals(expression.getType()) ? "0L" : "0"); |
| } |
| } |
| previousOperand = operand; |
| } |
| return ""; |
| } |
| |
| public static String getText(PsiPolyadicExpression expression, PsiElement fromTarget, PsiElement untilTarget, |
| @NotNull @NonNls String replacement) { |
| final StringBuilder result = new StringBuilder(); |
| boolean stop = false; |
| for (PsiElement child : expression.getChildren()) { |
| if (child == fromTarget) { |
| stop = true; |
| result.append(replacement); |
| } |
| else if (child == untilTarget) { |
| stop = false; |
| } |
| else if (child instanceof PsiComment || !stop) { |
| result.append(child.getText()); |
| } |
| else if (child instanceof PsiJavaToken && untilTarget == null) { |
| stop = false; |
| } |
| } |
| return result.toString(); |
| } |
| |
| private static String getText(PsiPolyadicExpression expression, PsiElement exclude) { |
| return getText(expression, exclude, null, "").trim(); |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new PointlessBitwiseVisitor(); |
| } |
| |
| @Override |
| public InspectionGadgetsFix buildFix(Object... infos) { |
| return new PointlessBitwiseFix(); |
| } |
| |
| private class PointlessBitwiseFix extends InspectionGadgetsFix { |
| |
| @Override |
| @NotNull |
| public String getName() { |
| return InspectionGadgetsBundle.message( |
| "pointless.bitwise.expression.simplify.quickfix"); |
| } |
| @Override |
| @NotNull |
| public String getFamilyName() { |
| return getName(); |
| } |
| |
| @Override |
| public void doFix(Project project, ProblemDescriptor descriptor) |
| throws IncorrectOperationException { |
| final PsiPolyadicExpression expression = (PsiPolyadicExpression) |
| descriptor.getPsiElement(); |
| final String newExpression = |
| calculateReplacementExpression(expression); |
| PsiReplacementUtil.replaceExpression(expression, newExpression); |
| } |
| } |
| |
| private class PointlessBitwiseVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitPolyadicExpression(@NotNull PsiPolyadicExpression expression) { |
| super.visitPolyadicExpression(expression); |
| final IElementType sign = expression.getOperationTokenType(); |
| if (!bitwiseTokens.contains(sign)) { |
| return; |
| } |
| if (PsiUtilCore.hasErrorElementChild(expression)) { |
| return; |
| } |
| final PsiExpression[] operands = expression.getOperands(); |
| for (PsiExpression operand : operands) { |
| if (operand == null) { |
| return; |
| } |
| final PsiType type = operand.getType(); |
| if (type == null || type.equals(PsiType.BOOLEAN) || |
| type.equalsToText(CommonClassNames.JAVA_LANG_BOOLEAN)) { |
| return; |
| } |
| } |
| final boolean isPointless; |
| if (sign.equals(JavaTokenType.AND) || sign.equals(JavaTokenType.OR) || |
| sign.equals(JavaTokenType.XOR)) { |
| isPointless = booleanExpressionIsPointless(operands); |
| } |
| else if (sign.equals(JavaTokenType.LTLT) || |
| sign.equals(JavaTokenType.GTGT) || |
| sign.equals(JavaTokenType.GTGTGT)) { |
| isPointless = shiftExpressionIsPointless(operands); |
| } |
| else { |
| isPointless = false; |
| } |
| if (!isPointless) { |
| return; |
| } |
| registerError(expression, expression); |
| } |
| |
| private boolean booleanExpressionIsPointless(PsiExpression[] operands) { |
| PsiExpression previousExpression = null; |
| for (PsiExpression operand : operands) { |
| if (isZero(operand) || isAllOnes(operand) || EquivalenceChecker.expressionsAreEquivalent(previousExpression, operand)) { |
| return true; |
| } |
| previousExpression = operand; |
| } |
| return false; |
| } |
| |
| private boolean shiftExpressionIsPointless(PsiExpression[] operands) { |
| for (PsiExpression operand : operands) { |
| if (isZero(operand)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| } |
| |
| private boolean isZero(PsiExpression expression) { |
| if (m_ignoreExpressionsContainingConstants |
| && !(expression instanceof PsiLiteralExpression)) { |
| return false; |
| } |
| return ExpressionUtils.isZero(expression); |
| } |
| |
| private boolean isAllOnes(PsiExpression expression) { |
| if (m_ignoreExpressionsContainingConstants |
| && !(expression instanceof PsiLiteralExpression)) { |
| return false; |
| } |
| final PsiType expressionType = expression.getType(); |
| final Object value = |
| ConstantExpressionUtil.computeCastTo(expression, |
| expressionType); |
| if (value == null) { |
| return false; |
| } |
| if (value instanceof Integer && |
| ((Integer)value).intValue() == 0xffffffff) { |
| return true; |
| } |
| if (value instanceof Long && |
| ((Long)value).longValue() == 0xffffffffffffffffL) { |
| return true; |
| } |
| if (value instanceof Short && |
| ((Short)value).shortValue() == (short)0xffff) { |
| return true; |
| } |
| if (value instanceof Character && |
| ((Character)value).charValue() == (char)0xffff) { |
| return true; |
| } |
| return value instanceof Byte && |
| ((Byte)value).byteValue() == (byte)0xff; |
| } |
| } |
