Make ClassDescriptor#classId nullable

Local classes or anonymous objects do not have a class id. Use "!!" almost
everywhere to make assertion explicit

compiler/backend/src/org/jetbrains/kotlin/codegen/state/KotlinTypeMapper.java

@@ -242,7 +242,7 @@ public class KotlinTypeMapper {
         }
 
         @NotNull
-        private static ContainingClassesInfo forClassMemberOrNull(@NotNull ClassId classId) {
+        private static ContainingClassesInfo forClassMember(@NotNull ClassId classId) {
             return new ContainingClassesInfo(classId, classId);
         }
     }
@@ -258,7 +258,7 @@ public class KotlinTypeMapper {
         }
         else {
             ClassId classId = getContainerClassIdForClassDescriptor((ClassDescriptor) parentDeclaration);
-            containingClassesInfo = ContainingClassesInfo.forClassMemberOrNull(classId);
+            containingClassesInfo = ContainingClassesInfo.forClassMember(classId);
         }
         if (containingClassesInfo == null) {
             throw new IllegalStateException("Couldn't find container for " + deserializedDescriptor.getName());
@@ -269,11 +269,14 @@ public class KotlinTypeMapper {
     @NotNull
     private static ClassId getContainerClassIdForClassDescriptor(@NotNull ClassDescriptor classDescriptor) {
         ClassId classId = DescriptorUtilsKt.getClassId(classDescriptor);
+        assert classId != null : "Deserialized class should have a ClassId: " + classDescriptor;
+
         if (isInterface(classDescriptor)) {
             FqName relativeClassName = classId.getRelativeClassName();
             //TODO test nested trait fun inlining
-            classId = new ClassId(classId.getPackageFqName(), Name.identifier(relativeClassName.shortName().asString() + JvmAbi.DEFAULT_IMPLS_SUFFIX));
+            return new ClassId(classId.getPackageFqName(), Name.identifier(relativeClassName.shortName().asString() + JvmAbi.DEFAULT_IMPLS_SUFFIX));
         }
+
         return classId;
     }
 

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/MissingDependencyClassChecker.kt

@@ -42,7 +42,7 @@ class MissingDependencyClassChecker : CallChecker {
 
         fun consider(classDescriptor: ClassDescriptor) {
             if (classDescriptor is NotFoundClasses.MockClassDescriptor) {
-                result.add(classDescriptor.classId)
+                result.add(classDescriptor.classId!!)
                 return
             }
             (classDescriptor.containingDeclaration as? ClassDescriptor)?.let(::consider)

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/annotationCheckers.kt

@@ -73,11 +73,11 @@ object FileClassAnnotationsChecker: AdditionalAnnotationChecker {
             fileAnnotationsToCheck.add(Pair(entry, classDescriptor))
         }
 
-        if (!fileAnnotationsToCheck.any { it.second.classId.asSingleFqName() == JvmFileClassUtil.JVM_MULTIFILE_CLASS }) return
+        if (!fileAnnotationsToCheck.any { it.second.classId?.asSingleFqName() == JvmFileClassUtil.JVM_MULTIFILE_CLASS }) return
 
         for ((entry, classDescriptor) in fileAnnotationsToCheck) {
-            val classFqName = classDescriptor.classId.asSingleFqName()
-            if (ALWAYS_APPLICABLE.contains(classFqName)) continue
+            val classFqName = classDescriptor.classId!!.asSingleFqName()
+            if (classFqName in ALWAYS_APPLICABLE) continue
             if (classDescriptor.getAnnotationRetention() != KotlinRetention.SOURCE) {
                 trace.report(ErrorsJvm.ANNOTATION_IS_NOT_APPLICABLE_TO_MULTIFILE_CLASSES.on(entry, classFqName))
             }

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.kt

@@ -74,16 +74,13 @@ val ClassifierDescriptorWithTypeParameters.denotedClassDescriptor: ClassDescript
         else -> throw UnsupportedOperationException("Unexpected descriptor kind: $this")
     }
 
-val ClassDescriptor.classId: ClassId
-    get() {
-        val owner = containingDeclaration
-        if (owner is PackageFragmentDescriptor) {
-            return ClassId(owner.fqName, name)
+val ClassDescriptor.classId: ClassId?
+    get() = containingDeclaration.let { owner ->
+        when (owner) {
+            is PackageFragmentDescriptor -> ClassId(owner.fqName, name)
+            is ClassDescriptor -> owner.classId?.createNestedClassId(name)
+            else -> null
         }
-        else if (owner is ClassDescriptor) {
-            return owner.classId.createNestedClassId(name)
-        }
-        throw IllegalStateException("Illegal container: $owner")
     }
 
 val ClassifierDescriptorWithTypeParameters.hasCompanionObject: Boolean

core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/descriptors/DeserializedClassDescriptor.kt

@@ -161,7 +161,7 @@ class DeserializedClassDescriptor(
             if (unresolved.isNotEmpty()) {
                 c.components.errorReporter.reportIncompleteHierarchy(
                         this@DeserializedClassDescriptor,
-                        unresolved.map { it.classId.asSingleFqName().asString() }
+                        unresolved.map { it.classId?.asSingleFqName()?.asString() ?: it.name.asString() }
                 )
             }
 

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

@@ -271,7 +271,7 @@ internal object RuntimeTypeMapper {
 
         val classId = klass.classId
         if (!classId.isLocal) {
-            JavaToKotlinClassMap.INSTANCE.mapJavaToKotlin(classId.asSingleFqName(), DefaultBuiltIns.Instance)?.let { return it.classId }
+            JavaToKotlinClassMap.INSTANCE.mapJavaToKotlin(classId.asSingleFqName(), DefaultBuiltIns.Instance)?.let { return it.classId!! }
         }
 
         return classId

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

@@ -51,7 +51,7 @@ internal fun ClassDescriptor.toJavaClass(): Class<*>? {
         else -> {
             // If this is neither a Kotlin class nor a Java class, it is either a built-in or some fake class descriptor like the one
             // that's created for java.io.Serializable in JvmBuiltInsSettings
-            val classId = JavaToKotlinClassMap.INSTANCE.mapKotlinToJava(DescriptorUtils.getFqName(this)) ?: classId
+            val classId = JavaToKotlinClassMap.INSTANCE.mapKotlinToJava(DescriptorUtils.getFqName(this)) ?: classId!!
             val packageName = classId.packageFqName.asString()
             val className = classId.relativeClassName.asString()
             // All pseudo-classes like kotlin.String.Companion must be accessible from the current class loader

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/LightMemberOriginForCompiledElement.kt

@@ -81,10 +81,10 @@ private fun PsiMember.relativeClassName(): List<Name> {
 }
 
 private fun ClassDescriptor.relativeClassName(): List<Name> {
-    return classId.relativeClassName.pathSegments().drop(1).orEmpty()
+    return classId!!.relativeClassName.pathSegments().drop(1).orEmpty()
 }
 
-private fun ClassDescriptor.desc(): String = "L" + JvmClassName.byClassId(classId).internalName + ";"
+private fun ClassDescriptor.desc(): String = "L" + JvmClassName.byClassId(classId!!).internalName + ";"
 
 private object ByJvmSignatureIndexer : DecompiledTextIndexer<ClassNameAndSignature> {
     override fun indexDescriptor(descriptor: DeclarationDescriptor): Collection<ClassNameAndSignature> {

js/js.serializer/src/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializationUtil.kt

@@ -187,7 +187,7 @@ object KotlinJavascriptSerializationUtil {
     }
 
     private fun getFileName(classDescriptor: ClassDescriptor): String {
-        return KotlinJavascriptSerializedResourcePaths.getClassMetadataPath(classDescriptor.classId)
+        return KotlinJavascriptSerializedResourcePaths.getClassMetadataPath(classDescriptor.classId!!)
     }
 
     fun toContentMap(module: ModuleDescriptor): Map<String, ByteArray> {