| /* |
| * Copyright 2003-2008 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.controlflow; |
| |
| import com.intellij.codeInspection.ProblemDescriptor; |
| import com.intellij.openapi.project.Project; |
| import com.intellij.psi.*; |
| import com.intellij.psi.tree.IElementType; |
| import com.intellij.psi.util.PsiTreeUtil; |
| import com.intellij.psi.util.PsiUtilCore; |
| import com.intellij.util.Function; |
| import com.intellij.util.IncorrectOperationException; |
| import com.intellij.util.containers.ContainerUtil; |
| 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.BoolUtils; |
| import com.siyeh.ig.psiutils.ControlFlowUtils; |
| import com.siyeh.ig.psiutils.EquivalenceChecker; |
| import org.jetbrains.annotations.NonNls; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.util.Collection; |
| |
| public class TrivialIfInspection extends BaseInspection { |
| |
| @Override |
| @NotNull |
| public String getID() { |
| return "RedundantIfStatement"; |
| } |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message("trivial.if.display.name"); |
| } |
| |
| @Override |
| public boolean isEnabledByDefault() { |
| return true; |
| } |
| |
| @Override |
| @NotNull |
| protected String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message("trivial.if.problem.descriptor"); |
| } |
| |
| @Override |
| public InspectionGadgetsFix buildFix(Object... infos) { |
| return new TrivialIfFix(); |
| } |
| |
| private static class TrivialIfFix 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) { |
| final PsiElement ifKeywordElement = descriptor.getPsiElement(); |
| final PsiIfStatement statement = (PsiIfStatement)ifKeywordElement.getParent(); |
| simplify(statement); |
| } |
| } |
| |
| public static void simplify(PsiIfStatement statement) { |
| if (isSimplifiableAssignment(statement)) { |
| replaceSimplifiableAssignment(statement); |
| } |
| else if (isSimplifiableReturn(statement)) { |
| repaceSimplifiableReturn(statement); |
| } |
| else if (isSimplifiableImplicitReturn(statement)) { |
| replaceSimplifiableImplicitReturn(statement); |
| } |
| else if (isSimplifiableAssignmentNegated(statement)) { |
| replaceSimplifiableAssignmentNegated(statement); |
| } |
| else if (isSimplifiableReturnNegated(statement)) { |
| repaceSimplifiableReturnNegated(statement); |
| } |
| else if (isSimplifiableImplicitReturnNegated(statement)) { |
| replaceSimplifiableImplicitReturnNegated(statement); |
| } |
| else if (isSimplifiableImplicitAssignment(statement)) { |
| replaceSimplifiableImplicitAssignment(statement); |
| } |
| else if (isSimplifiableImplicitAssignmentNegated(statement)) { |
| replaceSimplifiableImplicitAssignmentNegated(statement); |
| } |
| } |
| |
| private static void replaceSimplifiableImplicitReturn( |
| PsiIfStatement statement) throws IncorrectOperationException { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = condition.getText(); |
| final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(statement, PsiWhiteSpace.class); |
| @NonNls final String newStatement = "return " + conditionText + ';'; |
| PsiReplacementUtil.replaceStatement(statement, newStatement); |
| assert nextStatement != null; |
| nextStatement.delete(); |
| } |
| |
| private static void repaceSimplifiableReturn(PsiIfStatement statement) |
| throws IncorrectOperationException { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = condition.getText(); |
| @NonNls final String newStatement = "return " + conditionText + ';'; |
| final Collection<PsiComment> comments = PsiTreeUtil.findChildrenOfType(statement, PsiComment.class); |
| final PsiElement parent = statement.getParent(); |
| for (PsiComment comment : comments) { |
| parent.addBefore(comment.copy(), statement); |
| } |
| PsiReplacementUtil.replaceStatement(statement, newStatement); |
| } |
| |
| private static void replaceSimplifiableAssignment(PsiIfStatement statement) |
| throws IncorrectOperationException { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final Collection<PsiComment> comments = ContainerUtil.map(PsiTreeUtil.findChildrenOfType(statement, PsiComment.class), |
| new Function<PsiComment, PsiComment>() { |
| @Override |
| public PsiComment fun(PsiComment comment) { |
| return (PsiComment)comment.copy(); |
| } |
| }); |
| final String conditionText = condition.getText(); |
| final PsiStatement thenBranch = statement.getThenBranch(); |
| final PsiExpressionStatement assignmentStatement = (PsiExpressionStatement)ControlFlowUtils.stripBraces(thenBranch); |
| final PsiAssignmentExpression assignmentExpression = (PsiAssignmentExpression)assignmentStatement.getExpression(); |
| final PsiJavaToken operator = assignmentExpression.getOperationSign(); |
| final String operand = operator.getText(); |
| final PsiExpression lhs = assignmentExpression.getLExpression(); |
| final String lhsText = lhs.getText(); |
| final PsiElement parent = statement.getParent(); |
| for (PsiComment comment : comments) { |
| parent.addBefore(comment, statement); |
| } |
| PsiReplacementUtil.replaceStatement(statement, lhsText + operand + conditionText + ';'); |
| } |
| |
| private static void replaceSimplifiableImplicitAssignment(PsiIfStatement statement) throws IncorrectOperationException { |
| final PsiElement prevStatement = PsiTreeUtil.skipSiblingsBackward(statement, PsiWhiteSpace.class); |
| if (prevStatement == null) { |
| return; |
| } |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = condition.getText(); |
| final PsiStatement thenBranch = statement.getThenBranch(); |
| final PsiExpressionStatement assignmentStatement = |
| (PsiExpressionStatement) |
| ControlFlowUtils.stripBraces(thenBranch); |
| final PsiAssignmentExpression assignmentExpression = |
| (PsiAssignmentExpression)assignmentStatement.getExpression(); |
| final PsiJavaToken operator = |
| assignmentExpression.getOperationSign(); |
| final String operand = operator.getText(); |
| final PsiExpression lhs = assignmentExpression.getLExpression(); |
| final String lhsText = lhs.getText(); |
| PsiReplacementUtil.replaceStatement(statement, lhsText + operand + conditionText + ';'); |
| prevStatement.delete(); |
| } |
| |
| private static void replaceSimplifiableImplicitAssignmentNegated(PsiIfStatement statement) { |
| final PsiElement prevStatement = PsiTreeUtil.skipSiblingsBackward(statement, PsiWhiteSpace.class); |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = BoolUtils.getNegatedExpressionText(condition); |
| final PsiStatement thenBranch = statement.getThenBranch(); |
| final PsiExpressionStatement assignmentStatement = (PsiExpressionStatement)ControlFlowUtils.stripBraces(thenBranch); |
| final PsiAssignmentExpression assignmentExpression = (PsiAssignmentExpression) assignmentStatement.getExpression(); |
| final PsiJavaToken operator = |
| assignmentExpression.getOperationSign(); |
| final String operand = operator.getText(); |
| final PsiExpression lhs = assignmentExpression.getLExpression(); |
| final String lhsText = lhs.getText(); |
| PsiReplacementUtil.replaceStatement(statement, lhsText + operand + conditionText + ';'); |
| assert prevStatement != null; |
| prevStatement.delete(); |
| } |
| |
| private static void replaceSimplifiableImplicitReturnNegated(PsiIfStatement statement) { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = BoolUtils.getNegatedExpressionText(condition); |
| final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(statement, PsiWhiteSpace.class); |
| if (nextStatement == null) { |
| return; |
| } |
| @NonNls final String newStatement = "return " + conditionText + ';'; |
| PsiReplacementUtil.replaceStatement(statement, newStatement); |
| nextStatement.delete(); |
| } |
| |
| private static void repaceSimplifiableReturnNegated(PsiIfStatement statement) { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = BoolUtils.getNegatedExpressionText(condition); |
| @NonNls final String newStatement = "return " + conditionText + ';'; |
| PsiReplacementUtil.replaceStatement(statement, newStatement); |
| } |
| |
| private static void replaceSimplifiableAssignmentNegated(PsiIfStatement statement) { |
| final PsiExpression condition = statement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| final String conditionText = BoolUtils.getNegatedExpressionText(condition); |
| final PsiStatement thenBranch = statement.getThenBranch(); |
| final PsiExpressionStatement assignmentStatement = (PsiExpressionStatement)ControlFlowUtils.stripBraces(thenBranch); |
| final PsiAssignmentExpression assignmentExpression = (PsiAssignmentExpression)assignmentStatement.getExpression(); |
| final PsiJavaToken operator = |
| assignmentExpression.getOperationSign(); |
| final String operand = operator.getText(); |
| final PsiExpression lhs = assignmentExpression.getLExpression(); |
| final String lhsText = lhs.getText(); |
| PsiReplacementUtil.replaceStatement(statement, lhsText + operand + conditionText + ';'); |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new TrivialIfVisitor(); |
| } |
| |
| private static class TrivialIfVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitIfStatement(@NotNull PsiIfStatement ifStatement) { |
| super.visitIfStatement(ifStatement); |
| final PsiExpression condition = ifStatement.getCondition(); |
| if (condition == null) { |
| return; |
| } |
| if (isTrivial(ifStatement)) { |
| registerStatementError(ifStatement); |
| } |
| } |
| } |
| |
| public static boolean isTrivial(PsiIfStatement ifStatement) { |
| if (PsiUtilCore.hasErrorElementChild(ifStatement)) { |
| return false; |
| } |
| if (isSimplifiableAssignment(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableReturn(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableImplicitReturn(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableAssignmentNegated(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableReturnNegated(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableImplicitReturnNegated(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableImplicitAssignment(ifStatement)) { |
| return true; |
| } |
| if (isSimplifiableImplicitAssignmentNegated(ifStatement)) { |
| return true; |
| } |
| return false; |
| } |
| |
| public static boolean isSimplifiableImplicitReturn(PsiIfStatement ifStatement) { |
| if (ifStatement.getElseBranch() != null) { |
| return false; |
| } |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(ifStatement, PsiWhiteSpace.class); |
| if (!(nextStatement instanceof PsiStatement)) { |
| return false; |
| } |
| |
| final PsiStatement elseBranch = (PsiStatement)nextStatement; |
| return ConditionalUtils.isReturn(thenBranch, PsiKeyword.TRUE) |
| && ConditionalUtils.isReturn(elseBranch, PsiKeyword.FALSE); |
| } |
| |
| public static boolean isSimplifiableImplicitReturnNegated(PsiIfStatement ifStatement) { |
| if (ifStatement.getElseBranch() != null) { |
| return false; |
| } |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| |
| final PsiElement nextStatement = |
| PsiTreeUtil.skipSiblingsForward(ifStatement, |
| PsiWhiteSpace.class); |
| if (!(nextStatement instanceof PsiStatement)) { |
| return false; |
| } |
| final PsiStatement elseBranch = (PsiStatement)nextStatement; |
| return ConditionalUtils.isReturn(thenBranch, PsiKeyword.FALSE) |
| && ConditionalUtils.isReturn(elseBranch, PsiKeyword.TRUE); |
| } |
| |
| public static boolean isSimplifiableReturn(PsiIfStatement ifStatement) { |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| PsiStatement elseBranch = ifStatement.getElseBranch(); |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| return ConditionalUtils.isReturn(thenBranch, PsiKeyword.TRUE) |
| && ConditionalUtils.isReturn(elseBranch, PsiKeyword.FALSE); |
| } |
| |
| public static boolean isSimplifiableReturnNegated(PsiIfStatement ifStatement) { |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| PsiStatement elseBranch = ifStatement.getElseBranch(); |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| return ConditionalUtils.isReturn(thenBranch, PsiKeyword.FALSE) |
| && ConditionalUtils.isReturn(elseBranch, PsiKeyword.TRUE); |
| } |
| |
| public static boolean isSimplifiableAssignment(PsiIfStatement ifStatement) { |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| PsiStatement elseBranch = ifStatement.getElseBranch(); |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| if (ConditionalUtils.isAssignment(thenBranch, PsiKeyword.TRUE) && |
| ConditionalUtils.isAssignment(elseBranch, PsiKeyword.FALSE)) { |
| final PsiExpressionStatement thenExpressionStatement = |
| (PsiExpressionStatement)thenBranch; |
| final PsiAssignmentExpression thenExpression = |
| (PsiAssignmentExpression) |
| thenExpressionStatement.getExpression(); |
| final PsiExpressionStatement elseExpressionStatement = |
| (PsiExpressionStatement)elseBranch; |
| final PsiAssignmentExpression elseExpression = |
| (PsiAssignmentExpression) |
| elseExpressionStatement.getExpression(); |
| final IElementType thenTokenType = thenExpression.getOperationTokenType(); |
| if (!thenTokenType.equals(elseExpression.getOperationTokenType())) { |
| return false; |
| } |
| final PsiExpression thenLhs = thenExpression.getLExpression(); |
| final PsiExpression elseLhs = elseExpression.getLExpression(); |
| return EquivalenceChecker.expressionsAreEquivalent(thenLhs, |
| elseLhs); |
| } |
| else { |
| return false; |
| } |
| } |
| |
| public static boolean isSimplifiableAssignmentNegated(PsiIfStatement ifStatement) { |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| PsiStatement elseBranch = ifStatement.getElseBranch(); |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| if (ConditionalUtils.isAssignment(thenBranch, PsiKeyword.FALSE) && |
| ConditionalUtils.isAssignment(elseBranch, PsiKeyword.TRUE)) { |
| final PsiExpressionStatement thenExpressionStatement = |
| (PsiExpressionStatement)thenBranch; |
| final PsiAssignmentExpression thenExpression = |
| (PsiAssignmentExpression) |
| thenExpressionStatement.getExpression(); |
| final PsiExpressionStatement elseExpressionStatement = |
| (PsiExpressionStatement)elseBranch; |
| final PsiAssignmentExpression elseExpression = |
| (PsiAssignmentExpression) |
| elseExpressionStatement.getExpression(); |
| final IElementType thenTokenType = thenExpression.getOperationTokenType(); |
| if (!thenTokenType.equals(elseExpression.getOperationTokenType())) { |
| return false; |
| } |
| final PsiExpression thenLhs = thenExpression.getLExpression(); |
| final PsiExpression elseLhs = elseExpression.getLExpression(); |
| return EquivalenceChecker.expressionsAreEquivalent(thenLhs, |
| elseLhs); |
| } |
| else { |
| return false; |
| } |
| } |
| |
| public static boolean isSimplifiableImplicitAssignment(PsiIfStatement ifStatement) { |
| if (ifStatement.getElseBranch() != null) { |
| return false; |
| } |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| final PsiElement nextStatement = |
| PsiTreeUtil.skipSiblingsBackward(ifStatement, |
| PsiWhiteSpace.class); |
| if (!(nextStatement instanceof PsiStatement)) { |
| return false; |
| } |
| PsiStatement elseBranch = (PsiStatement)nextStatement; |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| if (ConditionalUtils.isAssignment(thenBranch, PsiKeyword.TRUE) && |
| ConditionalUtils.isAssignment(elseBranch, PsiKeyword.FALSE)) { |
| final PsiExpressionStatement thenExpressionStatement = |
| (PsiExpressionStatement)thenBranch; |
| final PsiAssignmentExpression thenExpression = |
| (PsiAssignmentExpression) |
| thenExpressionStatement.getExpression(); |
| final PsiExpressionStatement elseExpressionStatement = |
| (PsiExpressionStatement)elseBranch; |
| final PsiAssignmentExpression elseExpression = |
| (PsiAssignmentExpression) |
| elseExpressionStatement.getExpression(); |
| final IElementType thenTokenType = thenExpression.getOperationTokenType(); |
| if (!thenTokenType.equals(elseExpression.getOperationTokenType())) { |
| return false; |
| } |
| final PsiExpression thenLhs = thenExpression.getLExpression(); |
| final PsiExpression elseLhs = elseExpression.getLExpression(); |
| return EquivalenceChecker.expressionsAreEquivalent(thenLhs, |
| elseLhs); |
| } |
| else { |
| return false; |
| } |
| } |
| |
| public static boolean isSimplifiableImplicitAssignmentNegated(PsiIfStatement ifStatement) { |
| if (ifStatement.getElseBranch() != null) { |
| return false; |
| } |
| PsiStatement thenBranch = ifStatement.getThenBranch(); |
| thenBranch = ControlFlowUtils.stripBraces(thenBranch); |
| final PsiElement nextStatement = |
| PsiTreeUtil.skipSiblingsBackward(ifStatement, |
| PsiWhiteSpace.class); |
| if (!(nextStatement instanceof PsiStatement)) { |
| return false; |
| } |
| PsiStatement elseBranch = (PsiStatement)nextStatement; |
| elseBranch = ControlFlowUtils.stripBraces(elseBranch); |
| if (ConditionalUtils.isAssignment(thenBranch, PsiKeyword.FALSE) && |
| ConditionalUtils.isAssignment(elseBranch, PsiKeyword.TRUE)) { |
| final PsiExpressionStatement thenExpressionStatement = |
| (PsiExpressionStatement)thenBranch; |
| final PsiAssignmentExpression thenExpression = |
| (PsiAssignmentExpression) |
| thenExpressionStatement.getExpression(); |
| final PsiExpressionStatement elseExpressionStatement = |
| (PsiExpressionStatement)elseBranch; |
| final PsiAssignmentExpression elseExpression = |
| (PsiAssignmentExpression) |
| elseExpressionStatement.getExpression(); |
| final IElementType thenTokenType = thenExpression.getOperationTokenType(); |
| if (!thenTokenType.equals(elseExpression.getOperationTokenType())) { |
| return false; |
| } |
| final PsiExpression thenLhs = thenExpression.getLExpression(); |
| final PsiExpression elseLhs = elseExpression.getLExpression(); |
| return EquivalenceChecker.expressionsAreEquivalent(thenLhs, |
| elseLhs); |
| } |
| else { |
| return false; |
| } |
| } |
| } |
