| /* |
| * Copyright 2000-2013 JetBrains s.r.o. |
| * |
| * 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.migration; |
| |
| import com.intellij.psi.*; |
| import com.intellij.psi.util.InheritanceUtil; |
| import com.intellij.psi.util.PsiTreeUtil; |
| import com.intellij.psi.util.PsiUtil; |
| import com.siyeh.HardcodedMethodConstants; |
| import com.siyeh.InspectionGadgetsBundle; |
| import com.siyeh.ig.BaseInspection; |
| import com.siyeh.ig.BaseInspectionVisitor; |
| import com.siyeh.ig.psiutils.TypeUtils; |
| import com.siyeh.ig.psiutils.VariableAccessUtils; |
| import org.jetbrains.annotations.NonNls; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| public class WhileCanBeForeachInspectionBase extends BaseInspection { |
| @Nullable |
| public static PsiStatement getPreviousStatement(PsiElement context) { |
| final PsiElement prevStatement = PsiTreeUtil.skipSiblingsBackward(context, PsiWhiteSpace.class, PsiComment.class); |
| if (!(prevStatement instanceof PsiStatement)) { |
| return null; |
| } |
| return (PsiStatement)prevStatement; |
| } |
| |
| @Override |
| @NotNull |
| public String getID() { |
| return "WhileLoopReplaceableByForEach"; |
| } |
| |
| @Override |
| @NotNull |
| public String getDisplayName() { |
| return InspectionGadgetsBundle.message("while.can.be.foreach.display.name"); |
| } |
| |
| @Override |
| @NotNull |
| protected String buildErrorString(Object... infos) { |
| return InspectionGadgetsBundle.message("while.can.be.foreach.problem.descriptor"); |
| } |
| |
| @Override |
| public boolean isEnabledByDefault() { |
| return true; |
| } |
| |
| @Override |
| public BaseInspectionVisitor buildVisitor() { |
| return new WhileCanBeForeachVisitor(); |
| } |
| |
| private static class WhileCanBeForeachVisitor extends BaseInspectionVisitor { |
| |
| @Override |
| public void visitWhileStatement(@NotNull PsiWhileStatement whileStatement) { |
| super.visitWhileStatement(whileStatement); |
| if (!PsiUtil.isLanguageLevel5OrHigher(whileStatement)) { |
| return; |
| } |
| if (!isCollectionLoopStatement(whileStatement)) { |
| return; |
| } |
| registerStatementError(whileStatement); |
| } |
| |
| private static boolean isCollectionLoopStatement(PsiWhileStatement whileStatement) { |
| final PsiStatement initialization = getPreviousStatement(whileStatement); |
| if (!(initialization instanceof PsiDeclarationStatement)) { |
| return false; |
| } |
| final PsiDeclarationStatement declaration = (PsiDeclarationStatement)initialization; |
| final PsiElement[] declaredElements = declaration.getDeclaredElements(); |
| if (declaredElements.length != 1) { |
| return false; |
| } |
| final PsiElement declaredElement = declaredElements[0]; |
| if (!(declaredElement instanceof PsiVariable)) { |
| return false; |
| } |
| final PsiVariable variable = (PsiVariable)declaredElement; |
| if (!TypeUtils.variableHasTypeOrSubtype(variable, CommonClassNames.JAVA_UTIL_ITERATOR, "java.util.ListIterator")) { |
| return false; |
| } |
| final PsiExpression initialValue = variable.getInitializer(); |
| if (initialValue == null) { |
| return false; |
| } |
| if (!(initialValue instanceof PsiMethodCallExpression)) { |
| return false; |
| } |
| final PsiMethodCallExpression initialCall = (PsiMethodCallExpression)initialValue; |
| final PsiExpressionList argumentList = initialCall.getArgumentList(); |
| final PsiExpression[] argument = argumentList.getExpressions(); |
| if (argument.length != 0) { |
| return false; |
| } |
| final PsiReferenceExpression initialMethodExpression = initialCall.getMethodExpression(); |
| @NonNls final String initialCallName = initialMethodExpression.getReferenceName(); |
| if (!"iterator".equals(initialCallName) && !"listIterator".equals(initialCallName)) { |
| return false; |
| } |
| final PsiExpression qualifier = initialMethodExpression.getQualifierExpression(); |
| if (qualifier instanceof PsiSuperExpression) { |
| return false; |
| } |
| final PsiClass qualifierClass; |
| if (qualifier != null) { |
| final PsiType qualifierType = qualifier.getType(); |
| if (!(qualifierType instanceof PsiClassType)) { |
| return false; |
| } |
| qualifierClass = ((PsiClassType)qualifierType).resolve(); |
| } |
| else { |
| qualifierClass = PsiTreeUtil.getParentOfType(whileStatement, PsiClass.class); |
| } |
| if (qualifierClass == null) { |
| return false; |
| } |
| if (!InheritanceUtil.isInheritor(qualifierClass, CommonClassNames.JAVA_LANG_ITERABLE)) { |
| return false; |
| } |
| final PsiExpression condition = whileStatement.getCondition(); |
| if (!isHasNextCalled(variable, condition)) { |
| return false; |
| } |
| final PsiStatement body = whileStatement.getBody(); |
| if (body == null) { |
| return false; |
| } |
| if (calculateCallsToIteratorNext(variable, body) != 1) { |
| return false; |
| } |
| if (isIteratorRemoveCalled(variable, body)) { |
| return false; |
| } |
| //noinspection SimplifiableIfStatement |
| if (isIteratorHasNextCalled(variable, body)) { |
| return false; |
| } |
| if (VariableAccessUtils.variableIsAssigned(variable, body)) { |
| return false; |
| } |
| if (VariableAccessUtils.variableIsPassedAsMethodArgument(variable, body)) { |
| return false; |
| } |
| PsiElement nextSibling = whileStatement.getNextSibling(); |
| while (nextSibling != null) { |
| if (VariableAccessUtils.variableValueIsUsed(variable, nextSibling)) { |
| return false; |
| } |
| nextSibling = nextSibling.getNextSibling(); |
| } |
| return true; |
| } |
| |
| private static boolean isHasNextCalled(PsiVariable iterator, PsiExpression condition) { |
| if (!(condition instanceof PsiMethodCallExpression)) { |
| return false; |
| } |
| final PsiMethodCallExpression call = (PsiMethodCallExpression)condition; |
| final PsiExpressionList argumentList = call.getArgumentList(); |
| final PsiExpression[] arguments = argumentList.getExpressions(); |
| if (arguments.length != 0) { |
| return false; |
| } |
| final PsiReferenceExpression methodExpression = call.getMethodExpression(); |
| @NonNls final String methodName = methodExpression.getReferenceName(); |
| if (!HardcodedMethodConstants.HAS_NEXT.equals(methodName)) { |
| return false; |
| } |
| final PsiExpression qualifier = methodExpression.getQualifierExpression(); |
| if (qualifier == null) { |
| return true; |
| } |
| if (!(qualifier instanceof PsiReferenceExpression)) { |
| return false; |
| } |
| final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier; |
| final PsiElement target = referenceExpression.resolve(); |
| return iterator.equals(target); |
| } |
| |
| private static int calculateCallsToIteratorNext(PsiVariable iterator, PsiElement context) { |
| final NumberCallsToIteratorNextVisitor visitor = new NumberCallsToIteratorNextVisitor(iterator); |
| context.accept(visitor); |
| return visitor.getNumCallsToIteratorNext(); |
| } |
| |
| private static boolean isIteratorRemoveCalled(PsiVariable iterator, PsiElement context) { |
| final IteratorMethodCallVisitor visitor = new IteratorMethodCallVisitor(iterator); |
| context.accept(visitor); |
| return visitor.isMethodCalled(); |
| } |
| |
| private static boolean isIteratorHasNextCalled(PsiVariable iterator, PsiElement context) { |
| final IteratorHasNextVisitor visitor = new IteratorHasNextVisitor(iterator); |
| context.accept(visitor); |
| return visitor.isHasNextCalled(); |
| } |
| } |
| |
| private static class NumberCallsToIteratorNextVisitor extends JavaRecursiveElementVisitor { |
| |
| private int numCallsToIteratorNext = 0; |
| private final PsiVariable iterator; |
| |
| private NumberCallsToIteratorNextVisitor(PsiVariable iterator) { |
| this.iterator = iterator; |
| } |
| |
| @Override |
| public void visitMethodCallExpression(@NotNull PsiMethodCallExpression callExpression) { |
| super.visitMethodCallExpression(callExpression); |
| final PsiReferenceExpression methodExpression = callExpression.getMethodExpression(); |
| @NonNls final String methodName = methodExpression.getReferenceName(); |
| if (!HardcodedMethodConstants.NEXT.equals(methodName)) { |
| return; |
| } |
| final PsiExpression qualifier = methodExpression.getQualifierExpression(); |
| if (!(qualifier instanceof PsiReferenceExpression)) { |
| return; |
| } |
| final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier; |
| final PsiElement target = referenceExpression.resolve(); |
| if (!iterator.equals(target)) { |
| return; |
| } |
| numCallsToIteratorNext++; |
| } |
| |
| public int getNumCallsToIteratorNext() { |
| return numCallsToIteratorNext; |
| } |
| } |
| |
| private static class IteratorMethodCallVisitor extends JavaRecursiveElementVisitor { |
| |
| private boolean methodCalled = false; |
| private final PsiVariable iterator; |
| |
| IteratorMethodCallVisitor(PsiVariable iterator) { |
| this.iterator = iterator; |
| } |
| |
| @Override |
| public void visitElement(@NotNull PsiElement element) { |
| if (!methodCalled) { |
| super.visitElement(element); |
| } |
| } |
| |
| @Override |
| public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression) { |
| if (methodCalled) { |
| return; |
| } |
| super.visitMethodCallExpression(expression); |
| final PsiReferenceExpression methodExpression = expression.getMethodExpression(); |
| final String name = methodExpression.getReferenceName(); |
| if (HardcodedMethodConstants.NEXT.equals(name)) { |
| return; |
| } |
| final PsiExpression qualifier = methodExpression.getQualifierExpression(); |
| if (!(qualifier instanceof PsiReferenceExpression)) { |
| return; |
| } |
| final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier; |
| final PsiElement target = referenceExpression.resolve(); |
| if (iterator.equals(target)) { |
| methodCalled = true; |
| } |
| } |
| |
| public boolean isMethodCalled() { |
| return methodCalled; |
| } |
| } |
| |
| private static class IteratorHasNextVisitor extends JavaRecursiveElementVisitor { |
| |
| private boolean hasNextCalled = false; |
| private final PsiVariable iterator; |
| |
| private IteratorHasNextVisitor(PsiVariable iterator) { |
| this.iterator = iterator; |
| } |
| |
| @Override |
| public void visitElement(@NotNull PsiElement element) { |
| if (!hasNextCalled) { |
| super.visitElement(element); |
| } |
| } |
| |
| @Override |
| public void visitMethodCallExpression(@NotNull PsiMethodCallExpression expression) { |
| super.visitMethodCallExpression(expression); |
| final PsiReferenceExpression methodExpression = expression.getMethodExpression(); |
| @NonNls final String name = methodExpression.getReferenceName(); |
| if (!HardcodedMethodConstants.HAS_NEXT.equals(name)) { |
| return; |
| } |
| final PsiExpression qualifier = methodExpression.getQualifierExpression(); |
| if (!(qualifier instanceof PsiReferenceExpression)) { |
| return; |
| } |
| final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier; |
| final PsiElement target = referenceExpression.resolve(); |
| if (iterator.equals(target)) { |
| hasNextCalled = true; |
| } |
| } |
| |
| public boolean isHasNextCalled() { |
| return hasNextCalled; |
| } |
| } |
| } |