Java: don't consider constructors used when the class is used externally (IDEA-206602)

for global "Unused declaration" inspection

GitOrigin-RevId: e671cef5b81a2e148ec747e91e876959c0481d8d

java/java-analysis-impl/src/com/intellij/codeInspection/ex/EntryPointsManagerBase.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.codeInspection.ex;
 
 import com.intellij.codeInsight.AnnotationUtil;
@@ -268,13 +268,8 @@ public abstract class EntryPointsManagerBase extends EntryPointsManager implemen
         return;
       }
 
-      List<RefMethod> refConstructors = refClass.getConstructors();
-      if (refConstructors.size() == 1) {
-        addEntryPoint(refConstructors.get(0), isPersistent);
-      }
-      else if (refConstructors.size() > 1) {
-        // Many constructors here. Need to ask user which ones are used
-        for (RefMethod refConstructor : refConstructors) {
+      if (isPersistent) {
+        for (RefMethod refConstructor : refClass.getConstructors()) {
           addEntryPoint(refConstructor, isPersistent);
         }
       }

java/java-tests/testData/inspection/deadCode/SCR9690/ext_src/B.java

@@ -1,3 +1,7 @@
 class B extends A {
+
+  public static void main(String[] args) {
+    new B();
+  }
 }
 

java/java-tests/testData/inspection/deadCode/externallyUsedClass/expected.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+  <problem>
+    <file>UsefulClass.java</file>
+    <line>4</line>
+    <entry_point TYPE="method" FQNAME="a.UsefulClass UsefulClass()" />
+    <description>Constructor is never used.</description>
+  </problem>
+</problems>

java/java-tests/testData/inspection/deadCode/externallyUsedClass/src/a/UsefulClass.java

@@ -0,0 +1,6 @@
+package a;
+
+public class UsefulClass {
+    public UsefulClass() {
+    }
+}

java/java-tests/testData/inspection/deadCode/externallyUsedClass/test_src/b/Another.java

@@ -0,0 +1,6 @@
+package b;
+
+import a.UsefulClass;
+
+public class Another {
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationInSubScopeTest.java

@@ -1,6 +1,4 @@
-/*
- * Copyright 2000-2017 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.
- */
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.java.codeInspection;
 
 import com.intellij.analysis.AnalysisScope;
@@ -29,6 +27,10 @@ public class UnusedDeclarationInSubScopeTest extends AbstractUnusedDeclarationTe
     doTest();
   }
 
+  public void testExternallyUsedClass() {
+    doTest();
+  }
+
   @Override
   protected void doTest() {
     doTest("deadCode/" + getTestName(true), myToolWrapper);