| /* |
| * 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.controlflow; |
| |
| import com.intellij.codeInspection.ProblemDescriptor; |
| import com.intellij.openapi.project.Project; |
| import com.intellij.openapi.util.Ref; |
| import com.intellij.psi.*; |
| import com.intellij.psi.search.LocalSearchScope; |
| import com.intellij.psi.util.PsiTreeUtil; |
| import com.intellij.refactoring.extractMethod.InputVariables; |
| import com.intellij.refactoring.util.duplicates.ConditionalReturnStatementValue; |
| import com.intellij.refactoring.util.duplicates.DuplicatesFinder; |
| import com.intellij.refactoring.util.duplicates.Match; |
| import com.intellij.refactoring.util.duplicates.ReturnValue; |
| 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.ControlFlowUtils; |
| import com.siyeh.ig.psiutils.EquivalenceChecker; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.util.Collections; |
| |
| public class IfStatementWithIdenticalBranchesInspection |
| extends BaseInspection { |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message( |
| "if.statement.with.identical.branches.display.name"); |
| } |
| |
| @Override |
| @NotNull |
| public String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message( |
| "if.statement.with.identical.branches.problem.descriptor"); |
| } |
| |
| @Override |
| public InspectionGadgetsFix buildFix(Object... infos) { |
| return new CollapseIfFix(); |
| } |
| |
| private static class CollapseIfFix extends InspectionGadgetsFix { |
| |
| public CollapseIfFix() { |
| } |
| |
| @Override |
| @NotNull |
| public String getName() { |
| return InspectionGadgetsBundle.message( |
| "if.statement.with.identical.branches.collapse.quickfix"); |
| } |
| |
| @NotNull |
| @Override |
| public String getFamilyName() { |
| return getName(); |
| } |
| |
| @Override |
| public void doFix(@NotNull Project project, |
| ProblemDescriptor descriptor) |
| throws IncorrectOperationException { |
| final PsiElement identifier = descriptor.getPsiElement(); |
| final PsiIfStatement statement = |
| (PsiIfStatement)identifier.getParent(); |
| assert statement != null; |
| final PsiStatement thenBranch = statement.getThenBranch(); |
| if (thenBranch == null) { |
| return; |
| } |
| final PsiStatement elseBranch = statement.getElseBranch(); |
| if (elseBranch == null) { |
| // implicit else branch after the if |
| statement.delete(); |
| return; |
| } |
| if (elseBranch instanceof PsiIfStatement) { |
| final PsiIfStatement elseIfStatement = |
| (PsiIfStatement)elseBranch; |
| final PsiExpression condition1 = statement.getCondition(); |
| final PsiExpression condition2 = elseIfStatement.getCondition(); |
| if (condition1 == null) { |
| return; |
| } |
| PsiReplacementUtil.replaceExpression(condition1, buildOrExpressionText( |
| condition1, condition2)); |
| final PsiStatement elseElseBranch = |
| elseIfStatement.getElseBranch(); |
| if (elseElseBranch == null) { |
| elseIfStatement.delete(); |
| } |
| else { |
| elseIfStatement.replace(elseElseBranch); |
| } |
| } |
| else { |
| final PsiElement parent = statement.getParent(); |
| if (thenBranch instanceof PsiBlockStatement) { |
| final PsiBlockStatement blockStatement = |
| (PsiBlockStatement)thenBranch; |
| if (parent instanceof PsiCodeBlock) { |
| final PsiCodeBlock codeBlock = |
| blockStatement.getCodeBlock(); |
| final PsiStatement[] statements = |
| codeBlock.getStatements(); |
| if (statements.length > 0) { |
| parent.addRangeBefore(statements[0], |
| statements[statements.length - 1], statement); |
| } |
| statement.delete(); |
| } |
| else { |
| statement.replace(blockStatement); |
| } |
| } |
| else { |
| statement.replace(thenBranch); |
| } |
| } |
| } |
| |
| private static String buildOrExpressionText(PsiExpression expression1, |
| PsiExpression expression2) { |
| final StringBuilder result = new StringBuilder(); |
| if (expression1 != null) { |
| result.append(expression1.getText()); |
| } |
| result.append("||"); |
| if (expression2 != null) { |
| result.append(expression2.getText()); |
| } |
| return result.toString(); |
| } |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new IfStatementWithIdenticalBranchesVisitor(); |
| } |
| |
| private static class IfStatementWithIdenticalBranchesVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitIfStatement(@NotNull PsiIfStatement ifStatement) { |
| super.visitIfStatement(ifStatement); |
| final PsiStatement elseBranch = ifStatement.getElseBranch(); |
| final PsiStatement thenBranch = ifStatement.getThenBranch(); |
| if (thenBranch == null) { |
| return; |
| } |
| final Project project = ifStatement.getProject(); |
| final InputVariables inputVariables = |
| new InputVariables(Collections.<PsiVariable>emptyList(), |
| project, new LocalSearchScope(thenBranch), false); |
| final DuplicatesFinder finder = |
| new DuplicatesFinder(new PsiElement[]{thenBranch}, |
| inputVariables, null, |
| Collections.<PsiVariable>emptyList()); |
| if (elseBranch instanceof PsiIfStatement) { |
| final PsiIfStatement statement = (PsiIfStatement)elseBranch; |
| final PsiStatement branch = statement.getThenBranch(); |
| if (branch == null) { |
| return; |
| } |
| final Match match = finder.isDuplicate(branch, true); |
| if (match != null) { |
| final ReturnValue matchReturnValue = match.getReturnValue(); |
| if (matchReturnValue instanceof ConditionalReturnStatementValue && |
| !matchReturnValue.isEquivalent(buildReturnValue(thenBranch))) { |
| return; |
| } |
| registerStatementError(ifStatement, statement); |
| return; |
| } |
| } |
| if (elseBranch == null) { |
| checkIfStatementWithoutElseBranch(ifStatement); |
| } |
| else { |
| final Match match = finder.isDuplicate(elseBranch, true); |
| if (match != null) { |
| final ReturnValue matchReturnValue = match.getReturnValue(); |
| if (matchReturnValue instanceof ConditionalReturnStatementValue && |
| !matchReturnValue.isEquivalent(buildReturnValue(thenBranch))) { |
| return; |
| } |
| registerStatementError(ifStatement); |
| } |
| } |
| } |
| |
| @Nullable |
| private ReturnValue buildReturnValue(PsiElement element) { |
| final Ref<PsiReturnStatement> result = Ref.create(null); |
| element.accept(new JavaRecursiveElementWalkingVisitor() { |
| @Override |
| public void visitReturnStatement(PsiReturnStatement statement) { |
| super.visitReturnStatement(statement); |
| result.set(statement); |
| } |
| }); |
| final PsiReturnStatement returnStatement = result.get(); |
| if (returnStatement == null) { |
| return null; |
| } |
| final PsiExpression expression = returnStatement.getReturnValue(); |
| if (expression == null) { |
| return null; |
| } |
| return new ConditionalReturnStatementValue(expression); |
| } |
| |
| private void checkIfStatementWithoutElseBranch( |
| PsiIfStatement ifStatement) { |
| final PsiStatement thenBranch = ifStatement.getThenBranch(); |
| if (ControlFlowUtils.statementMayCompleteNormally(thenBranch)) { |
| return; |
| } |
| PsiStatement nextStatement = getNextStatement(ifStatement); |
| if (thenBranch instanceof PsiBlockStatement) { |
| final PsiBlockStatement blockStatement = |
| (PsiBlockStatement)thenBranch; |
| final PsiCodeBlock codeBlock = blockStatement.getCodeBlock(); |
| final PsiStatement[] statements = codeBlock.getStatements(); |
| final PsiStatement lastStatement = |
| statements[statements.length - 1]; |
| for (PsiStatement statement : statements) { |
| if (nextStatement == null) { |
| if (statement == lastStatement && |
| statement instanceof PsiReturnStatement) { |
| final PsiReturnStatement returnStatement = |
| (PsiReturnStatement)statement; |
| if (returnStatement.getReturnValue() == null) { |
| registerStatementError(ifStatement); |
| } |
| } |
| return; |
| } |
| else if (!EquivalenceChecker.statementsAreEquivalent( |
| statement, nextStatement)) { |
| return; |
| } |
| nextStatement = getNextStatement(nextStatement); |
| } |
| } |
| else if (!EquivalenceChecker.statementsAreEquivalent( |
| thenBranch, nextStatement)) { |
| return; |
| } |
| registerStatementError(ifStatement); |
| } |
| |
| @Nullable |
| private static PsiStatement getNextStatement(PsiStatement statement) { |
| PsiStatement nextStatement = |
| PsiTreeUtil.getNextSiblingOfType(statement, |
| PsiStatement.class); |
| while (nextStatement == null) { |
| //noinspection AssignmentToMethodParameter |
| statement = PsiTreeUtil.getParentOfType(statement, |
| PsiStatement.class); |
| if (statement == null) { |
| return null; |
| } |
| if (statement instanceof PsiLoopStatement) { |
| // return in a loop statement is not the same as continuing |
| // looping. |
| return statement; |
| } |
| nextStatement = PsiTreeUtil.getNextSiblingOfType(statement, |
| PsiStatement.class); |
| if (nextStatement == null) { |
| continue; |
| } |
| final PsiElement statementParent = statement.getParent(); |
| if (!(statementParent instanceof PsiIfStatement)) { |
| continue; |
| } |
| // nextStatement should not be the else part of an if statement |
| final PsiElement nextStatementParent = |
| nextStatement.getParent(); |
| if (statementParent.equals(nextStatementParent)) { |
| nextStatement = null; |
| } |
| } |
| return nextStatement; |
| } |
| } |
| } |