Do not compute stubs when building DefaultImpls light classes

Do not build stubs when computing inner classes of a light class
This should implicitly fix a deadlock reported in KT-9907 and KT-9811

compiler/light-classes/src/org/jetbrains/kotlin/asJava/JavaElementFinder.java

@@ -34,6 +34,7 @@ import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.load.java.JvmAbi;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.FqNamesUtilKt;
+import org.jetbrains.kotlin.psi.KtClass;
 import org.jetbrains.kotlin.psi.KtClassOrObject;
 import org.jetbrains.kotlin.psi.KtEnumEntry;
 import org.jetbrains.kotlin.psi.KtFile;
@@ -146,7 +147,8 @@ public class JavaElementFinder extends PsiElementFinder implements KotlinFinderM
         if (!qualifiedName.shortName().asString().equals(JvmAbi.DEFAULT_IMPLS_CLASS_NAME)) return;
 
         for (KtClassOrObject classOrObject : lightClassGenerationSupport.findClassOrObjectDeclarations(qualifiedName.parent(), scope)) {
-            if (LightClassUtilsKt.getHasInterfaceDefaultImpls(classOrObject)) {
+            //NOTE: can't filter out more interfaces right away because decompiled declarations do not have member bodies
+            if (classOrObject instanceof KtClass && ((KtClass) classOrObject).isInterface()) {
                 PsiClass interfaceClass = LightClassUtil.INSTANCE$.getPsiClass(classOrObject);
                 if (interfaceClass != null) {
                     PsiClass implsClass = interfaceClass.findInnerClassByName(JvmAbi.DEFAULT_IMPLS_CLASS_NAME, false);

compiler/light-classes/src/org/jetbrains/kotlin/asJava/KtLightClassForExplicitDeclaration.kt

@@ -45,6 +45,7 @@ import org.jetbrains.kotlin.psi.psiUtil.getStrictParentOfType
 import org.jetbrains.kotlin.psi.stubs.KotlinClassOrObjectStub
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.jvm.JvmClassName
+import java.util.*
 import javax.swing.Icon
 
 public open class KtLightClassForExplicitDeclaration(
@@ -364,12 +365,13 @@ public open class KtLightClassForExplicitDeclaration(
     override fun toString() = "${KtLightClass::class.java.simpleName}:$classFqName"
 
     override fun getOwnInnerClasses(): List<PsiClass> {
-        return getDelegate().innerClasses
-            .map {
-                val declaration = ClsWrapperStubPsiFactory.getOriginalDeclaration(it) as KtClassOrObject?
-                if (declaration != null) create(declaration, it) else null
-            }
-            .filterNotNull()
+        val result = ArrayList<PsiClass?>()
+        classOrObject.declarations.filterIsInstance<KtClassOrObject>().mapTo(result) { create(it) }
+
+        if (classOrObject.hasInterfaceDefaultImpls) {
+            result.add(KtLightClassForInterfaceDefaultImpls(classFqName.defaultImplsChild(), classOrObject))
+        }
+        return result.filterNotNull()
     }
 
     override fun getUseScope(): SearchScope = getOrigin().useScope
@@ -387,11 +389,7 @@ public open class KtLightClassForExplicitDeclaration(
                 FINAL_KEYWORD to PsiModifier.FINAL)
 
 
-        @JvmOverloads
-        public fun create(
-                classOrObject: KtClassOrObject,
-                psiClass: PsiClass? = null
-        ): KtLightClassForExplicitDeclaration? {
+        public fun create(classOrObject: KtClassOrObject): KtLightClassForExplicitDeclaration? {
             if (LightClassUtil.belongsToKotlinBuiltIns(classOrObject.getContainingKtFile())) {
                 return null
             }
@@ -402,13 +400,6 @@ public open class KtLightClassForExplicitDeclaration(
                 return KtLightClassForAnonymousDeclaration(fqName, classOrObject)
             }
 
-            if (classOrObject.hasInterfaceDefaultImpls) {
-                val implsFqName = fqName.defaultImplsChild()
-                if (implsFqName.asString() == psiClass?.qualifiedName) {
-                    return KtLightClassForInterfaceDefaultImpls(implsFqName, classOrObject)
-                }
-            }
-
             return KtLightClassForExplicitDeclaration(fqName, classOrObject)
         }
 

compiler/light-classes/src/org/jetbrains/kotlin/asJava/KtLightClassForInterfaceDefaultImpls.kt

@@ -48,4 +48,6 @@ public open class KtLightClassForInterfaceDefaultImpls(
     }
 
     override fun getContainingClass() = KtLightClassForExplicitDeclaration.create(classOrObject)
+
+    override fun getOwnInnerClasses() = emptyList<PsiClass>()
 }

idea/idea-completion/testData/injava/InterfaceDefaultImplsNonImported.java

@@ -0,0 +1,11 @@
+public class Testing {
+    public static void test() {
+        DefaultImpl<caret>
+    }
+}
+
+// EXIST:  { lookupString: "DefaultImpls", tailText: " (defaultImpls.NonAbstractFun)" }
+// EXIST:  { lookupString: "DefaultImpls", tailText: " (defaultImpls.NonAbstractFunWithExpressionBody)" }
+// EXIST:  { lookupString: "DefaultImpls", tailText: " (defaultImpls.NonAbstractProperty)" }
+// EXIST:  { lookupString: "DefaultImpls", tailText: " (defaultImpls.NonAbstractPropertyWithBody)" }
+// ABSENT:  { lookupString: "DefaultImpls", tailText: " (defaultImpls.AllAbstract)" }

idea/idea-completion/testData/injava/mockLib/defaultImpls.kt

@@ -0,0 +1,30 @@
+package defaultImpls;
+
+interface AllAbstract {
+    val c: Int
+    fun <T> f(t: T): T
+
+    val g: Int
+
+    var g2: String
+}
+
+interface NonAbstractFun {
+    fun f() {
+
+    }
+}
+
+interface NonAbstractFunWithExpressionBody {
+    fun f() = 3
+}
+
+interface NonAbstractProperty {
+    val c: Int get() = 3
+}
+
+interface NonAbstractPropertyWithBody {
+    val c: Int get() {
+        return 3
+    }
+}

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/CompiledKotlinInJavaCompletionTestGenerated.java

@@ -101,6 +101,12 @@ public class CompiledKotlinInJavaCompletionTestGenerated extends AbstractCompile
         doTest(fileName);
     }
 
+    @TestMetadata("InterfaceDefaultImplsNonImported.java")
+    public void testInterfaceDefaultImplsNonImported() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/injava/InterfaceDefaultImplsNonImported.java");
+        doTest(fileName);
+    }
+
     @TestMetadata("MultiFileFacade.java")
     public void testMultiFileFacade() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/injava/MultiFileFacade.java");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/KotlinSourceInJavaCompletionTestGenerated.java

@@ -101,6 +101,12 @@ public class KotlinSourceInJavaCompletionTestGenerated extends AbstractKotlinSou
         doTest(fileName);
     }
 
+    @TestMetadata("InterfaceDefaultImplsNonImported.java")
+    public void testInterfaceDefaultImplsNonImported() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/injava/InterfaceDefaultImplsNonImported.java");
+        doTest(fileName);
+    }
+
     @TestMetadata("MultiFileFacade.java")
     public void testMultiFileFacade() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/injava/MultiFileFacade.java");