From dbb8a2bac3f2d3069615e73867bff2185ec3d4a5 Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <basleijdekkers@gmail.com>
Date: Fri, 11 Oct 2019 16:22:17 +0200
Subject: [PATCH] unused declaration: a class with non-static fields is not a
 utility class

GitOrigin-RevId: 4c3f04dce18ee56fb0a0fe3beeee405fe91f750e
---
 .../reference/RefClassImpl.java               | 10 ++++--
 .../deadCode/nonUtility/expected.xml          | 32 +++++++++++++++++++
 .../deadCode/nonUtility/src/NonUtility.java   |  6 ++++
 .../codeInspection/UnusedDeclarationTest.java | 20 +++---------
 4 files changed, 50 insertions(+), 18 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/deadCode/nonUtility/expected.xml
 create mode 100644 java/java-tests/testData/inspection/deadCode/nonUtility/src/NonUtility.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefClassImpl.java b/java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefClassImpl.java
index c883b8ec3bb9..daa4e5fdf179 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefClassImpl.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefClassImpl.java
@@ -167,13 +167,17 @@ public class RefClassImpl extends RefJavaElementImpl implements RefClass {
         }
       }
     }
+    if (!isInterface()) {
+      for (int i = 0; i < uFields.length && utilityClass; i++) {
+        if (!uFields[i].isStatic()) {
+          utilityClass = false;
+        }
+      }
+    }
 
     if (!utilityClass) {
       utilityClass = ClassUtils.isSingleton(uClass.getJavaPsi());
     }
-    if (utilityClass && !isInterface() && uMethods.length == 0 && ContainerUtil.find(uFields, UField::isStatic) == null) {
-      utilityClass = false;
-    }
 
     if (varargConstructor != null && getDefaultConstructor() == null) {
       setDefaultConstructor((RefMethodImpl)varargConstructor);
diff --git a/java/java-tests/testData/inspection/deadCode/nonUtility/expected.xml b/java/java-tests/testData/inspection/deadCode/nonUtility/expected.xml
new file mode 100644
index 000000000000..c8fbfbb3a2da
--- /dev/null
+++ b/java/java-tests/testData/inspection/deadCode/nonUtility/expected.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+
+  <problem>
+    <file>NonUtility.java</file>
+    <line>1</line>
+    <problem_class>unused declaration</problem_class>
+    <description>Class is not instantiated.</description>
+  </problem>
+
+  <problem>
+    <file>NonUtility.java</file>
+    <line>2</line>
+    <problem_class>unused declaration</problem_class>
+    <description>Field has no usages.</description>
+  </problem>
+
+  <problem>
+    <file>NonUtility.java</file>
+    <line>3</line>
+    <problem_class>unused declaration</problem_class>
+    <description>Field has no usages.</description>
+  </problem>
+
+  <problem>
+    <file>NonUtility.java</file>
+    <line>5</line>
+    <problem_class>unused declaration</problem_class>
+    <description>Method is never used.</description>
+  </problem>
+
+</problems>
\ No newline at end of file
diff --git a/java/java-tests/testData/inspection/deadCode/nonUtility/src/NonUtility.java b/java/java-tests/testData/inspection/deadCode/nonUtility/src/NonUtility.java
new file mode 100644
index 000000000000..72e686990b20
--- /dev/null
+++ b/java/java-tests/testData/inspection/deadCode/nonUtility/src/NonUtility.java
@@ -0,0 +1,6 @@
+public class NonUtility {
+    private int i;
+    private int j;
+
+    public static void utility() {}
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationTest.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationTest.java
index c1cf4a92e7a7..04cc5e6b110b 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationTest.java
@@ -1,18 +1,4 @@
-/*
- * 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.
- */
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.java.codeInspection;
 
 import com.intellij.codeInspection.ex.EntryPointsManagerBase;
@@ -142,6 +128,10 @@ public class UnusedDeclarationTest extends AbstractUnusedDeclarationTest {
     doTest5();
   }
 
+  public void testNonUtility() {
+    doTest();
+  }
+
   public void testJunitEntryPoint() {
     doTest();
   }