| /* |
| * Copyright 2006-2011 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.classlayout; |
| |
| import com.intellij.analysis.AnalysisScope; |
| import com.intellij.codeInspection.*; |
| import com.intellij.codeInspection.reference.RefEntity; |
| import com.intellij.codeInspection.reference.RefMethod; |
| import com.intellij.openapi.util.Key; |
| import com.intellij.psi.*; |
| import com.intellij.psi.util.PsiUtil; |
| import com.siyeh.InspectionGadgetsBundle; |
| import com.siyeh.ig.BaseGlobalInspection; |
| import com.siyeh.ig.psiutils.MethodInheritanceUtils; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Set; |
| |
| public class MethodReturnAlwaysConstantInspection extends BaseGlobalInspection { |
| |
| private static final Key<Boolean> ALWAYS_CONSTANT = |
| Key.create("ALWAYS_CONSTANT"); |
| |
| @NotNull |
| @Override |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message( |
| "method.return.always.constant.display.name"); |
| } |
| |
| @Override |
| public CommonProblemDescriptor[] checkElement( |
| @NotNull RefEntity refEntity, @NotNull AnalysisScope scope, @NotNull InspectionManager manager, |
| @NotNull GlobalInspectionContext globalContext) { |
| if (!(refEntity instanceof RefMethod)) { |
| return null; |
| } |
| final RefMethod refMethod = (RefMethod)refEntity; |
| final Boolean alreadyProcessed = refMethod.getUserData(ALWAYS_CONSTANT); |
| if (alreadyProcessed != null && alreadyProcessed.booleanValue()) { |
| return null; |
| } |
| if (!(refMethod.getElement() instanceof PsiMethod)) { |
| return null; |
| } |
| final PsiMethod method = (PsiMethod)refMethod.getElement(); |
| if (method.getBody() == null) { |
| return null; //we'll catch it on another method |
| } |
| if (!alwaysReturnsConstant(method)) { |
| return null; |
| } |
| final Set<RefMethod> siblingMethods = |
| MethodInheritanceUtils.calculateSiblingMethods(refMethod); |
| for (RefMethod siblingMethod : siblingMethods) { |
| final PsiMethod siblingPsiMethod = |
| (PsiMethod)siblingMethod.getElement(); |
| if (method.getBody() != null && |
| !alwaysReturnsConstant(siblingPsiMethod)) { |
| return null; |
| } |
| } |
| final List<ProblemDescriptor> out = new ArrayList<ProblemDescriptor>(); |
| for (RefMethod siblingRefMethod : siblingMethods) { |
| final PsiMethod siblingMethod = |
| (PsiMethod)siblingRefMethod.getElement(); |
| final PsiIdentifier identifier = siblingMethod.getNameIdentifier(); |
| if (identifier == null) { |
| continue; |
| } |
| out.add(manager.createProblemDescriptor(identifier, |
| InspectionGadgetsBundle.message( |
| "method.return.always.constant.problem.descriptor"), false, null, |
| ProblemHighlightType.GENERIC_ERROR_OR_WARNING)); |
| siblingRefMethod.putUserData(ALWAYS_CONSTANT, |
| Boolean.valueOf(true)); |
| } |
| return out.toArray(new ProblemDescriptor[out.size()]); |
| } |
| |
| private static boolean alwaysReturnsConstant(PsiMethod method) { |
| final PsiCodeBlock body = method.getBody(); |
| if (body == null) { |
| return false; |
| } |
| final PsiStatement[] statements = body.getStatements(); |
| if (statements.length != 1) { |
| return false; |
| } |
| final PsiStatement statement = statements[0]; |
| if (!(statement instanceof PsiReturnStatement)) { |
| return false; |
| } |
| final PsiReturnStatement returnStatement = |
| (PsiReturnStatement)statement; |
| final PsiExpression value = returnStatement.getReturnValue(); |
| return value != null && PsiUtil.isConstantExpression(value); |
| } |
| } |