/*
* Copyright 2000-2017 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.intellij.codeInspection.miscGenerics;
import com.intellij.codeInsight.AnnotationUtil;
import com.intellij.codeInsight.ExpectedTypeInfo;
import com.intellij.codeInsight.ExpectedTypesProvider;
import com.intellij.codeInsight.daemon.GroupNames;
import com.intellij.codeInspection.*;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.util.TypeConversionUtil;
import com.intellij.refactoring.util.InlineUtil;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
* @author ven
*/
public class RedundantArrayForVarargsCallInspection extends GenericsInspectionToolBase {
private static final Logger LOG = Logger.getInstance("#com.intellij.codeInspection.miscGenerics.RedundantArrayForVarargsCallInspection");
private static final LocalQuickFix myQuickFixAction = new MyQuickFix();
private static class MyQuickFix implements LocalQuickFix {
@Override
public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
PsiNewExpression arrayCreation = (PsiNewExpression)descriptor.getPsiElement();
if (arrayCreation == null) return;
InlineUtil.inlineArrayCreationForVarargs(arrayCreation);
}
@Override
@NotNull
public String getFamilyName() {
return InspectionsBundle.message("inspection.redundant.array.creation.quickfix");
}
}
@Override
public ProblemDescriptor[] getDescriptions(@NotNull PsiElement place,
@NotNull final InspectionManager manager,
final boolean isOnTheFly) {
final List<ProblemDescriptor> problems = new ArrayList<>();
place.accept(new JavaRecursiveElementWalkingVisitor() {
@Override
public void visitCallExpression(PsiCallExpression expression) {
super.visitCallExpression(expression);
checkCall(expression);
}
@Override
public void visitEnumConstant(PsiEnumConstant enumConstant) {
super.visitEnumConstant(enumConstant);
checkCall(enumConstant);
}
@Override
public void visitClass(PsiClass aClass) {
//do not go inside to prevent multiple signals of the same problem
}
private void checkCall(PsiCall expression) {
final JavaResolveResult resolveResult = expression.resolveMethodGenerics();
PsiElement element = resolveResult.getElement();
final PsiSubstitutor substitutor = resolveResult.getSubstitutor();
if (!(element instanceof PsiMethod)) {
return;
}
PsiMethod method = (PsiMethod)element;
if (!method.isVarArgs() ||
AnnotationUtil.isAnnotated(method, Collections.singletonList("java.lang.invoke.MethodHandle.PolymorphicSignature"))) {
return;
}
PsiParameter[] parameters = method.getParameterList().getParameters();
PsiExpressionList argumentList = expression.getArgumentList();
if (argumentList == null) {
return;
}
PsiExpression[] args = argumentList.getExpressions();
if (parameters.length != args.length) {
return;
}
PsiExpression lastArg = args[args.length - 1];
PsiParameter lastParameter = parameters[args.length - 1];
if (!lastParameter.isVarArgs()) {
return;
}
PsiType lastParamType = lastParameter.getType();
LOG.assertTrue(lastParamType instanceof PsiEllipsisType, lastParamType);
if (!(lastArg instanceof PsiNewExpression)) {
return;
}
final PsiType substitutedLastParamType = substitutor.substitute(((PsiEllipsisType)lastParamType).toArrayType());
final PsiType lastArgType = lastArg.getType();
if (lastArgType == null || !lastArgType.equals(substitutedLastParamType) &&
!lastArgType.equals(TypeConversionUtil.erasure(substitutedLastParamType))) {
return;
}
PsiExpression[] initializers = getInitializers((PsiNewExpression)lastArg);
if (initializers == null) {
return;
}
if (Arrays.stream(initializers).anyMatch(expr -> expr instanceof PsiArrayInitializerExpression)) {
return;
}
if (!isSafeToFlatten(expression, method, initializers)) {
return;
}
String message = InspectionsBundle.message("inspection.redundant.array.creation.for.varargs.call.descriptor");
ProblemDescriptor descriptor = manager.createProblemDescriptor(lastArg, message, myQuickFixAction,
ProblemHighlightType.GENERIC_ERROR_OR_WARNING, isOnTheFly);
problems.add(descriptor);
}
private boolean isSafeToFlatten(@NotNull PsiCall callExpression, @NotNull PsiMethod oldRefMethod, @NotNull PsiExpression[] arrayElements) {
if (arrayElements.length == 1) {
PsiType type = arrayElements[0].getType();
// change foo(new Object[]{array}) to foo(array) is not safe
if (PsiType.NULL.equals(type) || type instanceof PsiArrayType) return false;
}
PsiCall copy = (PsiCall)callExpression.copy();
PsiExpressionList copyArgumentList = copy.getArgumentList();
LOG.assertTrue(copyArgumentList != null);
PsiExpression[] args = copyArgumentList.getExpressions();
try {
args[args.length - 1].delete();
if (arrayElements.length > 0) {
copyArgumentList.addRange(arrayElements[0], arrayElements[arrayElements.length - 1]);
}
final Project project = callExpression.getProject();
final JavaResolveResult resolveResult;
if (callExpression instanceof PsiEnumConstant) {
final PsiEnumConstant enumConstant = (PsiEnumConstant)callExpression;
final PsiClass containingClass = enumConstant.getContainingClass();
if (containingClass == null) return false;
final JavaPsiFacade facade = JavaPsiFacade.getInstance(project);
final PsiClassType classType = facade.getElementFactory().createType(containingClass);
resolveResult = facade.getResolveHelper().resolveConstructor(classType, copyArgumentList, enumConstant);
return resolveResult.isValidResult() && resolveResult.getElement() == oldRefMethod;
}
else {
resolveResult = copy.resolveMethodGenerics();
if (!resolveResult.isValidResult() || resolveResult.getElement() != oldRefMethod) {
return false;
}
if (callExpression.getParent() instanceof PsiExpressionStatement) return true;
final ExpectedTypeInfo[] expectedTypes = ExpectedTypesProvider.getExpectedTypes((PsiCallExpression)callExpression, false);
if (expectedTypes.length == 0) return false;
final PsiType expressionType = ((PsiCallExpression)copy).getType();
if (expressionType == null) return false;
for (ExpectedTypeInfo expectedType : expectedTypes) {
if (expectedType.getType().isAssignableFrom(expressionType)) {
return true;
}
}
return false;
}
}
catch (IncorrectOperationException e) {
return false;
}
}
});
if (problems.isEmpty()) return null;
return problems.toArray(new ProblemDescriptor[problems.size()]);
}
@Nullable
private static PsiExpression[] getInitializers(final PsiNewExpression newExpression) {
PsiArrayInitializerExpression initializer = newExpression.getArrayInitializer();
if (initializer != null) {
return initializer.getInitializers();
}
PsiExpression[] dims = newExpression.getArrayDimensions();
if (dims.length > 0) {
PsiExpression firstDimension = dims[0];
Object value =
JavaPsiFacade.getInstance(newExpression.getProject()).getConstantEvaluationHelper().computeConstantExpression(firstDimension);
if (value instanceof Integer && ((Integer)value).intValue() == 0) return PsiExpression.EMPTY_ARRAY;
}
return null;
}
@Override
@NotNull
public String getGroupDisplayName() {
return GroupNames.VERBOSE_GROUP_NAME;
}
@Override
@NotNull
public String getDisplayName() {
return InspectionsBundle.message("inspection.redundant.array.creation.display.name");
}
@Override
@NotNull
@NonNls
public String getShortName() {
return "RedundantArrayCreation";
}
}