/*
* Copyright 2006-2015 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.j2me;
import com.intellij.codeInspection.ProblemDescriptor;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.psi.*;
import com.intellij.psi.codeStyle.CodeStyleManager;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.util.PsiTreeUtil;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.InspectionGadgetsFix;
import com.siyeh.ig.psiutils.*;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.ArrayList;
import java.util.List;
public class SimplifiableIfStatementInspection extends BaseInspection {
@Override
@NotNull
public String getDisplayName() {
return InspectionGadgetsBundle.message("simplifiable.if.statement.display.name");
}
@Override
public boolean isEnabledByDefault() {
return true;
}
@Override
public BaseInspectionVisitor buildVisitor() {
return new SimplifiableIfStatementVisitor();
}
@Override
@NotNull
public String buildErrorString(Object... infos) {
final PsiIfStatement statement = (PsiIfStatement)infos[0];
return InspectionGadgetsBundle.message("simplifiable.if.statement.problem.descriptor",
StringUtil.escapeXml(calculateReplacementStatement(statement)));
}
@Nullable
@NonNls
static String calculateReplacementStatement(PsiIfStatement statement) {
final PsiStatement thenBranch = ControlFlowUtils.stripBraces(statement.getThenBranch());
if (thenBranch == null) {
return null;
}
PsiStatement elseBranch = statement.getElseBranch();
if (elseBranch == null) {
final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(statement, PsiWhiteSpace.class);
if (nextStatement instanceof PsiStatement) {
elseBranch = (PsiStatement)nextStatement;
}
} else {
elseBranch = ControlFlowUtils.stripBraces(elseBranch);
}
if (elseBranch == null) {
return null;
}
final PsiExpression condition = statement.getCondition();
if (condition == null) {
return null;
}
if (thenBranch instanceof PsiReturnStatement && elseBranch instanceof PsiReturnStatement) {
return calculateReplacementReturnStatement(thenBranch, elseBranch, condition);
} else if (thenBranch instanceof PsiExpressionStatement && elseBranch instanceof PsiExpressionStatement) {
final PsiExpressionStatement thenStatement = (PsiExpressionStatement)thenBranch;
final PsiExpressionStatement elseStatement = (PsiExpressionStatement)elseBranch;
final PsiExpression thenExpression = thenStatement.getExpression();
final PsiExpression elseExpression = elseStatement.getExpression();
if (!(thenExpression instanceof PsiAssignmentExpression) || !(elseExpression instanceof PsiAssignmentExpression)) {
return null;
}
final PsiAssignmentExpression thenAssignment = (PsiAssignmentExpression)thenExpression;
final PsiAssignmentExpression elseAssignment = (PsiAssignmentExpression)elseExpression;
return calculateReplacementAssignmentStatement(thenAssignment, elseAssignment, condition);
}
return null;
}
private static String calculateReplacementAssignmentStatement(PsiAssignmentExpression thenAssignment,
PsiAssignmentExpression elseAssignment, PsiExpression condition) {
final PsiExpression lhs = thenAssignment.getLExpression();
final PsiExpression thenRhs = thenAssignment.getRExpression();
if (thenRhs == null) {
return "";
}
final PsiExpression elseRhs = elseAssignment.getRExpression();
if (elseRhs == null) {
return "";
}
final PsiJavaToken token = elseAssignment.getOperationSign();
if (BoolUtils.isTrue(thenRhs)) {
return lhs.getText() + ' ' + token.getText() + ' ' +
buildExpressionText(condition, ParenthesesUtils.OR_PRECEDENCE) + " || " +
buildExpressionText(elseRhs, ParenthesesUtils.OR_PRECEDENCE) + ';';
}
else if (BoolUtils.isFalse(thenRhs)) {
return lhs.getText() + ' ' + token.getText() + ' ' +
BoolUtils.getNegatedExpressionText(condition, ParenthesesUtils.AND_PRECEDENCE) + " && " +
buildExpressionText(elseRhs, ParenthesesUtils.AND_PRECEDENCE) + ';';
}
if (BoolUtils.isTrue(elseRhs)) {
return lhs.getText() + ' ' + token.getText() + ' ' +
BoolUtils.getNegatedExpressionText(condition, ParenthesesUtils.OR_PRECEDENCE) + " || " +
buildExpressionText(thenRhs, ParenthesesUtils.OR_PRECEDENCE) + ';';
}
else {
return lhs.getText() + ' ' + token.getText() + ' ' +
buildExpressionText(condition, ParenthesesUtils.AND_PRECEDENCE) + " && " +
buildExpressionText(thenRhs, ParenthesesUtils.AND_PRECEDENCE) + ';';
}
}
@NonNls
private static String calculateReplacementReturnStatement(PsiStatement thenBranch, PsiStatement elseBranch, PsiExpression condition) {
final PsiReturnStatement thenReturnStatement = (PsiReturnStatement)thenBranch;
final PsiExpression thenReturnValue = thenReturnStatement.getReturnValue();
if (thenReturnValue == null) {
return "";
}
final PsiReturnStatement elseReturnStatement = (PsiReturnStatement)elseBranch;
final PsiExpression elseReturnValue = elseReturnStatement.getReturnValue();
if (elseReturnValue == null) {
return "";
}
if (BoolUtils.isTrue(thenReturnValue)) {
return "return " + buildExpressionText(condition, ParenthesesUtils.OR_PRECEDENCE) + " || " +
buildExpressionText(elseReturnValue, ParenthesesUtils.OR_PRECEDENCE) + ';';
}
else if (BoolUtils.isFalse(thenReturnValue)) {
return "return " + BoolUtils.getNegatedExpressionText(condition, ParenthesesUtils.AND_PRECEDENCE) + " && " +
buildExpressionText(elseReturnValue, ParenthesesUtils.AND_PRECEDENCE) + ';';
}
if (BoolUtils.isTrue(elseReturnValue)) {
return "return " + BoolUtils.getNegatedExpressionText(condition, ParenthesesUtils.OR_PRECEDENCE) + " || " +
buildExpressionText(thenReturnValue, ParenthesesUtils.OR_PRECEDENCE) + ';';
}
else {
return "return " + buildExpressionText(condition, ParenthesesUtils.AND_PRECEDENCE) + " && " +
buildExpressionText(thenReturnValue, ParenthesesUtils.AND_PRECEDENCE) + ';';
}
}
private static String buildExpressionText(PsiExpression expression, int precedence) {
final StringBuilder builder = new StringBuilder();
if (ParenthesesUtils.getPrecedence(expression) > precedence) {
builder.append('(');
appendPresentableText(expression, builder);
builder.append(')');
}
else {
appendPresentableText(expression, builder);
}
return builder.toString();
}
private static void appendPresentableText(@Nullable PsiElement element, StringBuilder builder) {
if (element == null) {
return;
}
if (element instanceof PsiWhiteSpace) {
final PsiElement prevSibling = element.getPrevSibling();
if (prevSibling instanceof PsiComment) {
final PsiComment comment = (PsiComment)prevSibling;
if (JavaTokenType.END_OF_LINE_COMMENT.equals(comment.getTokenType())) {
builder.append('\n');
return;
}
}
builder.append(' ');
return;
}
final PsiElement[] children = element.getChildren();
if (children.length == 0) {
builder.append(element.getText());
}
else {
for (PsiElement child : children) {
appendPresentableText(child, builder);
}
}
}
@Override
public InspectionGadgetsFix buildFix(Object... infos) {
return new SimplifiableIfStatementFix();
}
private static class SimplifiableIfStatementFix extends InspectionGadgetsFix {
@Override
@NotNull
public String getFamilyName() {
return InspectionGadgetsBundle.message("constant.conditional.expression.simplify.quickfix");
}
@Override
public void doFix(Project project, ProblemDescriptor descriptor) {
final PsiElement element = descriptor.getPsiElement();
final PsiIfStatement ifStatement = (PsiIfStatement)element.getParent();
List<PsiComment> before = new ArrayList<>();
List<PsiComment> after = new ArrayList<>();
collectComments(ifStatement, true, before, after);
final String newStatementText = calculateReplacementStatement(ifStatement);
if (newStatementText == null) {
return;
}
final StringBuilder codeBlockText = new StringBuilder("{\n");
for (PsiComment comment : before) {
codeBlockText.append(comment.getText()).append('\n');
}
codeBlockText.append(newStatementText).append('\n');
for (PsiComment comment : after) {
codeBlockText.append(comment.getText()).append('\n');
}
codeBlockText.append('}');
if (ifStatement.getElseBranch() == null) {
final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(ifStatement, PsiWhiteSpace.class);
if (nextStatement != null) {
nextStatement.delete();
}
}
final JavaPsiFacade psiFacade = JavaPsiFacade.getInstance(project);
final PsiCodeBlock codeBlock = psiFacade.getElementFactory().createCodeBlockFromText(codeBlockText.toString(), ifStatement);
final PsiElement parent = ifStatement.getParent();
PsiElement child = codeBlock.getFirstBodyElement();
final PsiElement end = codeBlock.getLastBodyElement();
while (true) {
parent.addBefore(child, ifStatement);
if (child == end) {
break;
}
child = child.getNextSibling();
}
ifStatement.delete();
CodeStyleManager.getInstance(project).reformat(parent);
}
private static void collectComments(PsiElement element, boolean first, List<PsiComment> before, List<PsiComment> after) {
if (element instanceof PsiComment) {
if (first) {
before.add((PsiComment)element);
}
else {
after.add((PsiComment)element);
}
return;
}
for (PsiElement child : element.getChildren()) {
if (child instanceof PsiKeyword) {
final PsiKeyword keyword = (PsiKeyword)child;
if (keyword.getTokenType() == JavaTokenType.ELSE_KEYWORD) {
first = false;
}
}
else {
collectComments(child, first, before, after);
}
}
}
}
private static class SimplifiableIfStatementVisitor extends BaseInspectionVisitor {
@Override
public void visitIfStatement(PsiIfStatement statement) {
super.visitIfStatement(statement);
if (statement.getCondition() == null) {
return;
}
if (!(isReplaceableAssignment(statement) || isReplaceableReturn(statement))) {
return;
}
registerStatementError(statement, statement);
}
public static boolean isReplaceableReturn(PsiIfStatement ifStatement) {
PsiStatement thenBranch = ifStatement.getThenBranch();
thenBranch = ControlFlowUtils.stripBraces(thenBranch);
PsiStatement elseBranch = ifStatement.getElseBranch();
elseBranch = ControlFlowUtils.stripBraces(elseBranch);
if (elseBranch == null) {
final PsiElement nextStatement = PsiTreeUtil.skipSiblingsForward(ifStatement, PsiWhiteSpace.class);
if (nextStatement instanceof PsiStatement) {
elseBranch = (PsiStatement)nextStatement;
}
}
if (!(thenBranch instanceof PsiReturnStatement) || !(elseBranch instanceof PsiReturnStatement)) {
return false;
}
final PsiExpression thenReturn = ((PsiReturnStatement)thenBranch).getReturnValue();
if (thenReturn == null) {
return false;
}
final PsiType thenType = thenReturn.getType();
if (!PsiType.BOOLEAN.equals(thenType)) {
return false;
}
final PsiExpression elseReturn = ((PsiReturnStatement)elseBranch).getReturnValue();
if (elseReturn == null) {
return false;
}
final PsiType elseType = elseReturn.getType();
if (!PsiType.BOOLEAN.equals(elseType)) {
return false;
}
final boolean thenConstant = BoolUtils.isFalse(thenReturn) || BoolUtils.isTrue(thenReturn);
final boolean elseConstant = BoolUtils.isFalse(elseReturn) || BoolUtils.isTrue(elseReturn);
return thenConstant != elseConstant;
}
public static boolean isReplaceableAssignment(PsiIfStatement ifStatement) {
PsiStatement thenBranch = ifStatement.getThenBranch();
if (thenBranch == null) {
return false;
}
thenBranch = ControlFlowUtils.stripBraces(thenBranch);
if (thenBranch == null || !isAssignment(thenBranch)) {
return false;
}
PsiStatement elseBranch = ifStatement.getElseBranch();
if (elseBranch == null) {
return false;
}
elseBranch = ControlFlowUtils.stripBraces(elseBranch);
if (elseBranch == null || !isAssignment(elseBranch)) {
return false;
}
final PsiExpressionStatement thenStatement = (PsiExpressionStatement)thenBranch;
final PsiAssignmentExpression thenExpression = (PsiAssignmentExpression)thenStatement.getExpression();
final PsiExpressionStatement elseStatement = (PsiExpressionStatement)elseBranch;
final PsiAssignmentExpression elseExpression = (PsiAssignmentExpression)elseStatement.getExpression();
final IElementType elseTokenType = elseExpression.getOperationTokenType();
if (!thenExpression.getOperationTokenType().equals(elseTokenType)) {
return false;
}
final PsiExpression thenRhs = thenExpression.getRExpression();
if (thenRhs == null) {
return false;
}
final PsiType thenRhsType = thenRhs.getType();
if (!PsiType.BOOLEAN.equals(thenRhsType)) {
return false;
}
final PsiExpression elseRhs = elseExpression.getRExpression();
if (elseRhs == null) {
return false;
}
final PsiType elseRhsType = elseRhs.getType();
if (!PsiType.BOOLEAN.equals(elseRhsType)) {
return false;
}
final boolean thenConstant = BoolUtils.isFalse(thenRhs) || BoolUtils.isTrue(thenRhs);
final boolean elseConstant = BoolUtils.isFalse(elseRhs) || BoolUtils.isTrue(elseRhs);
if (thenConstant == elseConstant) {
return false;
}
final PsiExpression thenLhs = thenExpression.getLExpression();
final PsiExpression elseLhs = elseExpression.getLExpression();
return EquivalenceChecker.getCanonicalPsiEquivalence().expressionsAreEquivalent(thenLhs, elseLhs);
}
public static boolean isAssignment(@Nullable PsiStatement statement) {
if (!(statement instanceof PsiExpressionStatement)) {
return false;
}
final PsiExpressionStatement expressionStatement = (PsiExpressionStatement)statement;
final PsiExpression expression = expressionStatement.getExpression();
return expression instanceof PsiAssignmentExpression;
}
}
}