Test that no delegated properties are used in critical classes in reflection

compiler/tests/org/jetbrains/kotlin/code/ReflectionCodeSanityTest.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2010-2015 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 org.jetbrains.kotlin.code
+
+import junit.framework.TestCase
+import org.jetbrains.kotlin.codegen.forTestCompile.ForTestCompileRuntime
+import org.jetbrains.kotlin.load.java.JvmAbi
+import java.lang.reflect.Field
+
+class ReflectionCodeSanityTest : TestCase() {
+    fun testNoDelegatedPropertiesInKClassAndKProperties() {
+        val classLoader = ForTestCompileRuntime.runtimeAndReflectJarClassLoader()
+
+        val classesToCheck = linkedSetOf<Class<*>>()
+        fun addClassToCheck(klass: Class<*>) {
+            if (classesToCheck.add(klass)) {
+                @Suppress("UNNECESSARY_SAFE_CALL") // https://youtrack.jetbrains.com/issue/KT-9294
+                klass.superclass?.let { addClassToCheck(it) }
+            }
+        }
+
+        fun addClass(name: String) = addClassToCheck(classLoader.loadClass("kotlin.reflect.jvm.internal.$name"))
+
+        addClass("KClassImpl")
+        addClass("KMutableProperty0Impl")
+        addClass("KMutableProperty1Impl")
+        addClass("KMutableProperty2Impl")
+
+        val badFields = linkedSetOf<Field>()
+        for (klass in classesToCheck) {
+            badFields.addAll(klass.declaredFields.filter { it.name.endsWith(JvmAbi.DELEGATED_PROPERTY_NAME_SUFFIX) })
+        }
+
+        if (badFields.isNotEmpty()) {
+            fail("The fields listed below appear to be delegates for properties.\n" +
+                 "It's highly not recommended to use property delegates in reflection.jvm because a KProperty instance\n" +
+                 "is created for each delegated property and that makes the initialization sequence of reflection\n" +
+                 "implementation classes unpredictable and leads to a deadlock or ExceptionInInitializerError.\n\n" +
+                 "Please un-delegate the corresponding properties:\n\n" +
+                 badFields.joinToString("\n"))
+        }
+    }
+}

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KDeclarationContainerImpl.kt

@@ -37,8 +37,6 @@ import kotlin.reflect.KCallable
 import kotlin.reflect.KotlinReflectionInternalError
 
 internal abstract class KDeclarationContainerImpl : ClassBasedDeclarationContainer {
-    // NB: be careful not to introduce delegated properties in this class and subclasses, there are problems with circular dependencies
-
     // Note: this is stored here on a soft reference to prevent GC from destroying the weak reference to it in the moduleByClassLoader cache
     private val moduleData_ = ReflectProperties.lazySoft {
         jClass.getOrCreateModule()