Support JvmPackageName with JvmMultifileClass

This is an internal feature of our standard library needed to compile
new API for unsigned types

compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassCodegen.kt

@@ -39,6 +39,7 @@ import org.jetbrains.kotlin.psi.KtTypeAlias
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.MemberComparator
 import org.jetbrains.kotlin.resolve.jvm.AsmTypes
+import org.jetbrains.kotlin.resolve.jvm.JvmClassName
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.MultifileClass
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.MultifileClassPart
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.OtherOrigin
@@ -49,7 +50,6 @@ import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedCallableMemberDescriptor
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedPropertyDescriptor
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedSimpleFunctionDescriptor
-import org.jetbrains.kotlin.utils.SmartList
 import org.jetbrains.org.objectweb.asm.MethodVisitor
 import org.jetbrains.org.objectweb.asm.Opcodes
 import org.jetbrains.org.objectweb.asm.Type
@@ -66,7 +66,7 @@ class MultifileClassCodegenImpl(
 ) : MultifileClassCodegen {
     private val facadeClassType = AsmUtil.asmTypeByFqNameWithoutInnerClasses(facadeFqName)
 
-    private val packageFragment = getOnlyPackageFragment(facadeFqName.parent(), files, state.module)
+    private val packageFragment = getOnlyPackageFragment(files, state.module)
 
     private val compiledPackageFragment = getCompiledPackageFragment(facadeFqName, state)
 
@@ -329,6 +329,20 @@ class MultifileClassCodegenImpl(
                 arv.visit(null, internalName)
             }
             arv.visitEnd()
+
+            val kotlinPackageFqName =
+                packageFragment?.fqName ?: compiledPackageFragment?.fqName
+                ?: error("Either source package or compiled package should not be null: $facadeClassType ($files)")
+
+            if (files.any { it.packageFqName != kotlinPackageFqName })
+                throw UnsupportedOperationException(
+                    "Multi-file parts of a facade with JvmPackageName should all lie in the same Kotlin package:\n  " +
+                            files.joinToString("\n  ") { file -> "$file: package ${file.packageFqName}" }
+                )
+
+            if (kotlinPackageFqName != JvmClassName.byInternalName(facadeClassType.internalName).packageFqName) {
+                av.visit(JvmAnnotationNames.METADATA_PACKAGE_NAME_FIELD_NAME, kotlinPackageFqName.asString())
+            }
         }
     }
 
@@ -350,21 +364,10 @@ class MultifileClassCodegenImpl(
         private val J_L_OBJECT = AsmTypes.OBJECT_TYPE.internalName
         private const val FACADE_CLASS_ATTRIBUTES = Opcodes.ACC_PUBLIC or Opcodes.ACC_FINAL or Opcodes.ACC_SUPER
 
-        private fun getOnlyPackageFragment(
-            packageFqName: FqName,
-            files: Collection<KtFile>,
-            moduleDescriptor: ModuleDescriptor
-        ): PackageFragmentDescriptor? {
-            val fragments = SmartList<PackageFragmentDescriptor>()
-            for (file in files) {
-                val fragment = moduleDescriptor.findPackageFragmentForFile(file)
+        private fun getOnlyPackageFragment(files: Collection<KtFile>, moduleDescriptor: ModuleDescriptor): PackageFragmentDescriptor? {
+            val fragments = files.mapTo(linkedSetOf()) { file ->
+                moduleDescriptor.findPackageFragmentForFile(file)
                     ?: throw AssertionError("package fragment is null for " + file + "\n" + file.text)
-
-                assert(packageFqName == fragment.fqName) { "expected package fq name: " + packageFqName + ", actual: " + fragment.fqName }
-
-                if (!fragments.contains(fragment)) {
-                    fragments.add(fragment)
-                }
             }
             if (fragments.size > 1) {
                 throw IllegalStateException("More than one package fragment, files: $files | fragments: $fragments")

compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassPartCodegen.kt

@@ -22,9 +22,11 @@ import org.jetbrains.kotlin.codegen.context.MultifileClassPartContext
 import org.jetbrains.kotlin.codegen.state.GenerationState
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames.METADATA_PACKAGE_NAME_FIELD_NAME
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtProperty
+import org.jetbrains.kotlin.resolve.jvm.JvmClassName
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.OtherOrigin
 import org.jetbrains.org.objectweb.asm.Opcodes
 
@@ -97,6 +99,11 @@ class MultifileClassPartCodegen(
         writeKotlinMetadata(v, state, KotlinClassHeader.Kind.MULTIFILE_CLASS_PART, extraFlags) { av ->
             AsmUtil.writeAnnotationData(av, serializer, packageProto)
             av.visit(JvmAnnotationNames.METADATA_MULTIFILE_CLASS_NAME_FIELD_NAME, facadeClassType.internalName)
+
+            val kotlinPackageFqName = element.packageFqName
+            if (kotlinPackageFqName != JvmClassName.byInternalName(partType.internalName).packageFqName) {
+                av.visit(METADATA_PACKAGE_NAME_FIELD_NAME, kotlinPackageFqName.asString())
+            }
         }
     }
 

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

@@ -28,7 +28,10 @@ import org.jetbrains.kotlin.resolve.AdditionalAnnotationChecker
 import org.jetbrains.kotlin.resolve.AnnotationChecker
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingTrace
-import org.jetbrains.kotlin.resolve.descriptorUtil.*
+import org.jetbrains.kotlin.resolve.descriptorUtil.annotationClass
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.resolve.descriptorUtil.getAnnotationRetention
+import org.jetbrains.kotlin.resolve.descriptorUtil.isRepeatableAnnotation
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
 
 object RepeatableAnnotationChecker: AdditionalAnnotationChecker {
@@ -81,12 +84,8 @@ object FileClassAnnotationsChecker: AdditionalAnnotationChecker {
                 if (classDescriptor.getAnnotationRetention() != KotlinRetention.SOURCE) {
                     trace.report(ErrorsJvm.ANNOTATION_IS_NOT_APPLICABLE_TO_MULTIFILE_CLASSES.on(entry, classFqName))
                 }
-                if (classFqName == JvmFileClassUtil.JVM_PACKAGE_NAME) {
-                    trace.report(ErrorsJvm.JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_MULTIFILE_CLASSES.on(entry))
-                }
             }
-        }
-        else {
+        } else {
             for ((entry, classDescriptor) in fileAnnotationsToCheck) {
                 if (classDescriptor.fqNameSafe != JvmFileClassUtil.JVM_PACKAGE_NAME) continue
 
@@ -97,13 +96,11 @@ object FileClassAnnotationsChecker: AdditionalAnnotationChecker {
                 val value = (stringTemplateEntries.singleOrNull() as? KtLiteralStringTemplateEntry)?.text
                 if (value == null) {
                     trace.report(ErrorsJvm.JVM_PACKAGE_NAME_CANNOT_BE_EMPTY.on(entry))
-                }
-                else if (!isValidJavaFqName(value)) {
+                } else if (!isValidJavaFqName(value)) {
                     trace.report(ErrorsJvm.JVM_PACKAGE_NAME_MUST_BE_VALID_NAME.on(entry))
-                }
-                else if (entry.containingKtFile.declarations.any {
-                    it !is KtFunction && it !is KtProperty && it !is KtTypeAlias
-                }) {
+                } else if (entry.containingKtFile.declarations.any {
+                        it !is KtFunction && it !is KtProperty && it !is KtTypeAlias
+                    }) {
                     trace.report(ErrorsJvm.JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_FILES_WITH_CLASSES.on(entry))
                 }
             }

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java

@@ -67,7 +67,6 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
         MAP.put(NON_SOURCE_REPEATED_ANNOTATION, "Repeatable annotations with non-SOURCE retention are not yet supported");
         MAP.put(ANNOTATION_IS_NOT_APPLICABLE_TO_MULTIFILE_CLASSES, "Annotation ''@{0}'' is not applicable to the multi-file classes", TO_STRING);
 
-        MAP.put(JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_MULTIFILE_CLASSES, "''@JvmPackageName'' annotation is not supported in multi-file classes");
         MAP.put(JVM_PACKAGE_NAME_CANNOT_BE_EMPTY, "''@JvmPackageName'' annotation value cannot be empty");
         MAP.put(JVM_PACKAGE_NAME_MUST_BE_VALID_NAME, "''@JvmPackageName'' annotation value must be a valid dot-qualified name of a package");
         MAP.put(JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_FILES_WITH_CLASSES, "''@JvmPackageName'' annotation is not supported for files with class declarations");

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java

@@ -68,7 +68,6 @@ public interface ErrorsJvm {
     DiagnosticFactory0<KtAnnotationEntry> NON_SOURCE_REPEATED_ANNOTATION = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<KtAnnotationEntry, FqName> ANNOTATION_IS_NOT_APPLICABLE_TO_MULTIFILE_CLASSES = DiagnosticFactory1.create(ERROR);
 
-    DiagnosticFactory0<KtAnnotationEntry> JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_MULTIFILE_CLASSES = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> JVM_PACKAGE_NAME_CANNOT_BE_EMPTY = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> JVM_PACKAGE_NAME_MUST_BE_VALID_NAME = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_FILES_WITH_CLASSES = DiagnosticFactory0.create(ERROR);

compiler/testData/codegen/box/jvmPackageName/multifileClass.kt

@@ -0,0 +1,41 @@
+// IGNORE_BACKEND: JVM_IR
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+// FILE: A1.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+@file:JvmPackageName("baz.foo.quux.bar")
+@file:JvmName("Facade")
+@file:JvmMultifileClass
+package foo.bar
+
+val g: S? get() = f().substring(0, 0) + "K"
+
+// FILE: A2.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+@file:JvmPackageName("baz.foo.quux.bar")
+@file:JvmName("Facade")
+@file:JvmMultifileClass
+package foo.bar
+
+inline fun <T> i(block: () -> T): T = block()
+
+// FILE: A3.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+@file:JvmPackageName("baz.foo.quux.bar")
+@file:JvmName("Facade")
+@file:JvmMultifileClass
+package foo.bar
+
+typealias S = String
+
+fun f(): String = "O"
+
+// FILE: B.kt
+
+import foo.bar.*
+
+fun box(): S = i { f() + g }

compiler/testData/compileKotlinAgainstKotlin/jvmPackageNameMultifileClass.kt

@@ -0,0 +1,25 @@
+// IGNORE_BACKEND: JVM_IR
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+// FILE: A.kt
+
+@file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+@file:JvmPackageName("baz.foo.quux.bar")
+@file:JvmName("Facade")
+@file:JvmMultifileClass
+package foo.bar
+
+typealias S = String
+
+fun f(): String = "O"
+
+val g: S? get() = f().substring(0, 0) + "K"
+
+inline fun <T> i(block: () -> T): T = block()
+
+// FILE: B.kt
+
+import foo.bar.*
+
+fun box(): S = i { f() + g }

compiler/testData/diagnostics/testsWithStdLib/annotations/jvmPackageName/incorrectJvmPackageName.kt

@@ -1,11 +1,5 @@
 // !DIAGNOSTICS: -INVISIBLE_MEMBER -INVISIBLE_REFERENCE
 
-// FILE: a.kt
-<!JVM_PACKAGE_NAME_NOT_SUPPORTED_IN_MULTIFILE_CLASSES!>@file:JvmPackageName("a")<!>
-@file:JvmMultifileClass
-package a
-fun a() {}
-
 // FILE: b.kt
 <!JVM_PACKAGE_NAME_CANNOT_BE_EMPTY!>@file:JvmPackageName("")<!>
 package b

compiler/testData/diagnostics/testsWithStdLib/annotations/jvmPackageName/incorrectJvmPackageName.txt

@@ -1,9 +1,5 @@
 package
 
-package a {
-    public fun a(): kotlin.Unit
-}
-
 package b {
     public fun b(): kotlin.Unit
 }

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K1_A.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmPackageName("j1")
+@file:JvmName("K1")
+@file:JvmMultifileClass
+package k1
+
+fun f1() {}

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K1_B.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmPackageName("j1")
+@file:JvmName("K1")
+@file:JvmMultifileClass
+package k1
+
+val v2 = Unit

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K1_C.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmPackageName("j1")
+@file:JvmName("K1")
+@file:JvmMultifileClass
+package k1
+
+typealias T3 = List<String>

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K2_A.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmPackageName("j2")
+@file:JvmName("K2")
+@file:JvmMultifileClass
+package k2
+
+fun f1() {}

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K2_B.kt

@@ -0,0 +1,7 @@
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@file:JvmPackageName("j3")
+@file:JvmName("K2")
+@file:JvmMultifileClass
+package k2
+
+val v2 = Unit

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/K2_C.kt

@@ -0,0 +1,5 @@
+@file:JvmName("K2")
+@file:JvmMultifileClass
+package k2
+
+typealias T3 = List<String>

compiler/testData/moduleProtoBuf/jvmPackageNameMultifileClass/module-proto.txt

@@ -0,0 +1,8 @@
+k1
+  j1/K1__K1_AKt (j1/K1)
+  j1/K1__K1_BKt (j1/K1)
+  j1/K1__K1_CKt (j1/K1)
+k2
+  k2/K2__K2_CKt (k2/K2)
+  j2/K2__K2_AKt (j2/K2)
+  j3/K2__K2_BKt (j3/K2)

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -14655,6 +14655,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
         }
 
+        @TestMetadata("multifileClass.kt")
+        public void testMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmPackageName/multifileClass.kt");
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             runTest("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");

compiler/tests/org/jetbrains/kotlin/codegen/CompileKotlinAgainstKotlinTestGenerated.java

@@ -188,6 +188,11 @@ public class CompileKotlinAgainstKotlinTestGenerated extends AbstractCompileKotl
         runTest("compiler/testData/compileKotlinAgainstKotlin/jvmPackageNameInRootPackage.kt");
     }
 
+    @TestMetadata("jvmPackageNameMultifileClass.kt")
+    public void testJvmPackageNameMultifileClass() throws Exception {
+        runTest("compiler/testData/compileKotlinAgainstKotlin/jvmPackageNameMultifileClass.kt");
+    }
+
     @TestMetadata("jvmPackageNameWithJvmName.kt")
     public void testJvmPackageNameWithJvmName() throws Exception {
         runTest("compiler/testData/compileKotlinAgainstKotlin/jvmPackageNameWithJvmName.kt");

compiler/tests/org/jetbrains/kotlin/codegen/JvmModuleProtoBufTest.kt

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.codegen
 
 import org.jetbrains.kotlin.cli.jvm.K2JVMCompiler
 import org.jetbrains.kotlin.config.ApiVersion
-import org.jetbrains.kotlin.config.KotlinCompilerVersion
 import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.config.LanguageVersionSettingsImpl
 import org.jetbrains.kotlin.load.kotlin.loadModuleMapping
@@ -31,28 +30,28 @@ import java.io.File
 
 class JvmModuleProtoBufTest : KtUsefulTestCase() {
     private fun doTest(
-            relativeDirectory: String,
-            compileWith: LanguageVersion = LanguageVersion.LATEST_STABLE,
-            loadWith: LanguageVersion = LanguageVersion.LATEST_STABLE,
-            extraOptions: List<String> = emptyList()
+        relativeDirectory: String,
+        compileWith: LanguageVersion = LanguageVersion.LATEST_STABLE,
+        loadWith: LanguageVersion = LanguageVersion.LATEST_STABLE,
+        extraOptions: List<String> = emptyList()
     ) {
         val directory = KotlinTestUtils.getTestDataPathBase() + relativeDirectory
         val tmpdir = KotlinTestUtils.tmpDir(this::class.simpleName)
 
         val moduleName = "main"
-        CompilerTestUtil.executeCompilerAssertSuccessful(K2JVMCompiler(), listOf(
+        CompilerTestUtil.executeCompilerAssertSuccessful(
+            K2JVMCompiler(), listOf(
                 directory,
                 "-d", tmpdir.path,
                 "-module-name", moduleName,
                 "-language-version", compileWith.versionString
-        ) + extraOptions)
+            ) + extraOptions
+        )
 
         val mapping = ModuleMapping.loadModuleMapping(
-                File(tmpdir, "META-INF/$moduleName.${ModuleMapping.MAPPING_FILE_EXT}").readBytes(), "test",
-                CompilerDeserializationConfiguration(
-                        LanguageVersionSettingsImpl(loadWith, ApiVersion.createByLanguageVersion(loadWith))
-                ),
-                ::error
+            File(tmpdir, "META-INF/$moduleName.${ModuleMapping.MAPPING_FILE_EXT}").readBytes(), "test",
+            CompilerDeserializationConfiguration(LanguageVersionSettingsImpl(loadWith, ApiVersion.createByLanguageVersion(loadWith))),
+            ::error
         )
         val result = buildString {
             for (annotationClassId in mapping.moduleData.annotations) {
@@ -82,18 +81,19 @@ class JvmModuleProtoBufTest : KtUsefulTestCase() {
     }
 
     fun testJvmPackageName() {
-        doTest("/moduleProtoBuf/jvmPackageName",
-               compileWith = LanguageVersion.KOTLIN_1_2, loadWith = LanguageVersion.KOTLIN_1_2)
+        doTest("/moduleProtoBuf/jvmPackageName")
     }
 
     fun testJvmPackageNameManyParts() {
-        doTest("/moduleProtoBuf/jvmPackageNameManyParts",
-               compileWith = LanguageVersion.KOTLIN_1_2, loadWith = LanguageVersion.KOTLIN_1_2)
+        doTest("/moduleProtoBuf/jvmPackageNameManyParts")
     }
 
     fun testJvmPackageNameLanguageVersion11() {
-        doTest("/moduleProtoBuf/jvmPackageNameLanguageVersion11",
-               compileWith = LanguageVersion.KOTLIN_1_2, loadWith = LanguageVersion.KOTLIN_1_1)
+        doTest("/moduleProtoBuf/jvmPackageNameLanguageVersion11", loadWith = LanguageVersion.KOTLIN_1_1)
+    }
+
+    fun testJvmPackageNameMultifileClass() {
+        doTest("/moduleProtoBuf/jvmPackageNameMultifileClass")
     }
 
     fun testExperimental() {

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -14655,6 +14655,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
         }
 
+        @TestMetadata("multifileClass.kt")
+        public void testMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmPackageName/multifileClass.kt");
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             runTest("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -14660,6 +14660,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/jvmPackageName/metadataField.kt");
         }
 
+        @TestMetadata("multifileClass.kt")
+        public void testMultifileClass() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmPackageName/multifileClass.kt");
+        }
+
         @TestMetadata("rootPackage.kt")
         public void testRootPackage() throws Exception {
             runTest("compiler/testData/codegen/box/jvmPackageName/rootPackage.kt");

core/metadata.jvm/src/jvm_module.proto

@@ -41,11 +41,13 @@ message Module {
 }
 
 message PackageParts {
+  // Dot-separated Kotlin FQ name of the package.
   required string package_fq_name = 1;
 
   // Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
   // (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-  // Kotlin package name (i.e. it has not been changed with @JvmPackageName) are listed here.
+  // Kotlin package name (i.e. it has not been changed with @JvmPackageName) are listed here, the rest are listed in
+  // class_with_jvm_package_name_short_name.
   repeated string short_class_name = 2;
 
   // For each name in short_class_name, index of the name of the corresponding multi-file facade class in multifile_facade_short_name + 1,
@@ -54,12 +56,24 @@ message PackageParts {
   repeated int32 multifile_facade_short_name_id = 3 [packed = true];
 
   // Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -> facade mapping.
+  //
+  // The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by @JvmPackageName,
+  // and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+  // otherwise behavior is unspecified.
   repeated string multifile_facade_short_name = 4;
 
-  // Short names of files (single file facades), whose JVM package differs from the Kotlin package because of @JvmPackageName.
-  // The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+  // Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+  // @JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
   repeated string class_with_jvm_package_name_short_name = 5;
 
+  // This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+  // multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+  // names of multi-file facades whose JVM package differs from the Kotlin package because of @JvmPackageName.
+  //
+  // For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+  // multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+  repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];
+
   // For each name in class_with_jvm_package_name_short_name, the index (into PackageTable#jvm_package_name) of the JVM package name.
   // This list should have at least one element, otherwise classes with JVM package names are going to be ignored completely.
   //

core/metadata.jvm/src/org/jetbrains/kotlin/metadata/jvm/JvmModuleProtoBuf.java

@@ -1702,14 +1702,26 @@ public final class JvmModuleProtoBuf {
 
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     boolean hasPackageFqName();
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     java.lang.String getPackageFqName();
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
         getPackageFqNameBytes();
@@ -1720,7 +1732,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1731,7 +1744,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     int getShortClassNameCount();
@@ -1741,7 +1755,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     java.lang.String getShortClassName(int index);
@@ -1751,7 +1766,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
@@ -1793,6 +1809,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1802,6 +1821,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     int getMultifileFacadeShortNameCount();
@@ -1810,6 +1832,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     java.lang.String getMultifileFacadeShortName(int index);
@@ -1818,6 +1843,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
@@ -1827,8 +1855,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1837,8 +1865,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     int getClassWithJvmPackageNameShortNameCount();
@@ -1846,8 +1874,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     java.lang.String getClassWithJvmPackageNameShortName(int index);
@@ -1855,13 +1883,50 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
         getClassWithJvmPackageNameShortNameBytes(int index);
 
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    java.util.List<java.lang.Integer> getClassWithJvmPackageNameMultifileFacadeShortNameIdList();
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    int getClassWithJvmPackageNameMultifileFacadeShortNameIdCount();
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    int getClassWithJvmPackageNameMultifileFacadeShortNameId(int index);
+
     /**
      * <code>repeated int32 class_with_jvm_package_name_package_id = 6 [packed = true];</code>
      *
@@ -2004,9 +2069,9 @@ public final class JvmModuleProtoBuf {
               break;
             }
             case 48: {
-              if (!((mutable_bitField0_ & 0x00000020) == 0x00000020)) {
+              if (!((mutable_bitField0_ & 0x00000040) == 0x00000040)) {
                 classWithJvmPackageNamePackageId_ = new java.util.ArrayList<java.lang.Integer>();
-                mutable_bitField0_ |= 0x00000020;
+                mutable_bitField0_ |= 0x00000040;
               }
               classWithJvmPackageNamePackageId_.add(input.readInt32());
               break;
@@ -2014,9 +2079,9 @@ public final class JvmModuleProtoBuf {
             case 50: {
               int length = input.readRawVarint32();
               int limit = input.pushLimit(length);
-              if (!((mutable_bitField0_ & 0x00000020) == 0x00000020) && input.getBytesUntilLimit() > 0) {
+              if (!((mutable_bitField0_ & 0x00000040) == 0x00000040) && input.getBytesUntilLimit() > 0) {
                 classWithJvmPackageNamePackageId_ = new java.util.ArrayList<java.lang.Integer>();
-                mutable_bitField0_ |= 0x00000020;
+                mutable_bitField0_ |= 0x00000040;
               }
               while (input.getBytesUntilLimit() > 0) {
                 classWithJvmPackageNamePackageId_.add(input.readInt32());
@@ -2024,6 +2089,27 @@ public final class JvmModuleProtoBuf {
               input.popLimit(limit);
               break;
             }
+            case 56: {
+              if (!((mutable_bitField0_ & 0x00000020) == 0x00000020)) {
+                classWithJvmPackageNameMultifileFacadeShortNameId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000020;
+              }
+              classWithJvmPackageNameMultifileFacadeShortNameId_.add(input.readInt32());
+              break;
+            }
+            case 58: {
+              int length = input.readRawVarint32();
+              int limit = input.pushLimit(length);
+              if (!((mutable_bitField0_ & 0x00000020) == 0x00000020) && input.getBytesUntilLimit() > 0) {
+                classWithJvmPackageNameMultifileFacadeShortNameId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000020;
+              }
+              while (input.getBytesUntilLimit() > 0) {
+                classWithJvmPackageNameMultifileFacadeShortNameId_.add(input.readInt32());
+              }
+              input.popLimit(limit);
+              break;
+            }
           }
         }
       } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
@@ -2044,9 +2130,12 @@ public final class JvmModuleProtoBuf {
         if (((mutable_bitField0_ & 0x00000010) == 0x00000010)) {
           classWithJvmPackageNameShortName_ = classWithJvmPackageNameShortName_.getUnmodifiableView();
         }
-        if (((mutable_bitField0_ & 0x00000020) == 0x00000020)) {
+        if (((mutable_bitField0_ & 0x00000040) == 0x00000040)) {
           classWithJvmPackageNamePackageId_ = java.util.Collections.unmodifiableList(classWithJvmPackageNamePackageId_);
         }
+        if (((mutable_bitField0_ & 0x00000020) == 0x00000020)) {
+          classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.unmodifiableList(classWithJvmPackageNameMultifileFacadeShortNameId_);
+        }
         try {
           unknownFieldsCodedOutput.flush();
         } catch (java.io.IOException e) {
@@ -2077,12 +2166,20 @@ public final class JvmModuleProtoBuf {
     private java.lang.Object packageFqName_;
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     public boolean hasPackageFqName() {
       return ((bitField0_ & 0x00000001) == 0x00000001);
     }
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     public java.lang.String getPackageFqName() {
       java.lang.Object ref = packageFqName_;
@@ -2100,6 +2197,10 @@ public final class JvmModuleProtoBuf {
     }
     /**
      * <code>required string package_fq_name = 1;</code>
+     *
+     * <pre>
+     * Dot-separated Kotlin FQ name of the package.
+     * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
         getPackageFqNameBytes() {
@@ -2123,7 +2224,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -2136,7 +2238,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     public int getShortClassNameCount() {
@@ -2148,7 +2251,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     public java.lang.String getShortClassName(int index) {
@@ -2160,7 +2264,8 @@ public final class JvmModuleProtoBuf {
      * <pre>
      * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
      * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+     * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+     * class_with_jvm_package_name_short_name.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
@@ -2216,6 +2321,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -2227,6 +2335,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     public int getMultifileFacadeShortNameCount() {
@@ -2237,6 +2348,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     public java.lang.String getMultifileFacadeShortName(int index) {
@@ -2247,6 +2361,9 @@ public final class JvmModuleProtoBuf {
      *
      * <pre>
      * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+     * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+     * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+     * otherwise behavior is unspecified.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
@@ -2260,8 +2377,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -2272,8 +2389,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     public int getClassWithJvmPackageNameShortNameCount() {
@@ -2283,8 +2400,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     public java.lang.String getClassWithJvmPackageNameShortName(int index) {
@@ -2294,8 +2411,8 @@ public final class JvmModuleProtoBuf {
      * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
      *
      * <pre>
-     * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-     * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+     * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+     * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
@@ -2303,6 +2420,53 @@ public final class JvmModuleProtoBuf {
       return classWithJvmPackageNameShortName_.getByteString(index);
     }
 
+    public static final int CLASS_WITH_JVM_PACKAGE_NAME_MULTIFILE_FACADE_SHORT_NAME_ID_FIELD_NUMBER = 7;
+    private java.util.List<java.lang.Integer> classWithJvmPackageNameMultifileFacadeShortNameId_;
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    public java.util.List<java.lang.Integer>
+        getClassWithJvmPackageNameMultifileFacadeShortNameIdList() {
+      return classWithJvmPackageNameMultifileFacadeShortNameId_;
+    }
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    public int getClassWithJvmPackageNameMultifileFacadeShortNameIdCount() {
+      return classWithJvmPackageNameMultifileFacadeShortNameId_.size();
+    }
+    /**
+     * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+     *
+     * <pre>
+     * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+     * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+     * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+     * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+     * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+     * </pre>
+     */
+    public int getClassWithJvmPackageNameMultifileFacadeShortNameId(int index) {
+      return classWithJvmPackageNameMultifileFacadeShortNameId_.get(index);
+    }
+    private int classWithJvmPackageNameMultifileFacadeShortNameIdMemoizedSerializedSize = -1;
+
     public static final int CLASS_WITH_JVM_PACKAGE_NAME_PACKAGE_ID_FIELD_NUMBER = 6;
     private java.util.List<java.lang.Integer> classWithJvmPackageNamePackageId_;
     /**
@@ -2356,6 +2520,7 @@ public final class JvmModuleProtoBuf {
       multifileFacadeShortNameId_ = java.util.Collections.emptyList();
       multifileFacadeShortName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
       classWithJvmPackageNameShortName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+      classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.emptyList();
       classWithJvmPackageNamePackageId_ = java.util.Collections.emptyList();
     }
     private byte memoizedIsInitialized = -1;
@@ -2401,6 +2566,13 @@ public final class JvmModuleProtoBuf {
       for (int i = 0; i < classWithJvmPackageNamePackageId_.size(); i++) {
         output.writeInt32NoTag(classWithJvmPackageNamePackageId_.get(i));
       }
+      if (getClassWithJvmPackageNameMultifileFacadeShortNameIdList().size() > 0) {
+        output.writeRawVarint32(58);
+        output.writeRawVarint32(classWithJvmPackageNameMultifileFacadeShortNameIdMemoizedSerializedSize);
+      }
+      for (int i = 0; i < classWithJvmPackageNameMultifileFacadeShortNameId_.size(); i++) {
+        output.writeInt32NoTag(classWithJvmPackageNameMultifileFacadeShortNameId_.get(i));
+      }
       output.writeRawBytes(unknownFields);
     }
 
@@ -2469,6 +2641,20 @@ public final class JvmModuleProtoBuf {
         }
         classWithJvmPackageNamePackageIdMemoizedSerializedSize = dataSize;
       }
+      {
+        int dataSize = 0;
+        for (int i = 0; i < classWithJvmPackageNameMultifileFacadeShortNameId_.size(); i++) {
+          dataSize += org.jetbrains.kotlin.protobuf.CodedOutputStream
+            .computeInt32SizeNoTag(classWithJvmPackageNameMultifileFacadeShortNameId_.get(i));
+        }
+        size += dataSize;
+        if (!getClassWithJvmPackageNameMultifileFacadeShortNameIdList().isEmpty()) {
+          size += 1;
+          size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+              .computeInt32SizeNoTag(dataSize);
+        }
+        classWithJvmPackageNameMultifileFacadeShortNameIdMemoizedSerializedSize = dataSize;
+      }
       size += unknownFields.size();
       memoizedSerializedSize = size;
       return size;
@@ -2573,8 +2759,10 @@ public final class JvmModuleProtoBuf {
         bitField0_ = (bitField0_ & ~0x00000008);
         classWithJvmPackageNameShortName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
         bitField0_ = (bitField0_ & ~0x00000010);
-        classWithJvmPackageNamePackageId_ = java.util.Collections.emptyList();
+        classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.emptyList();
         bitField0_ = (bitField0_ & ~0x00000020);
+        classWithJvmPackageNamePackageId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000040);
         return this;
       }
 
@@ -2623,9 +2811,14 @@ public final class JvmModuleProtoBuf {
         }
         result.classWithJvmPackageNameShortName_ = classWithJvmPackageNameShortName_;
         if (((bitField0_ & 0x00000020) == 0x00000020)) {
-          classWithJvmPackageNamePackageId_ = java.util.Collections.unmodifiableList(classWithJvmPackageNamePackageId_);
+          classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.unmodifiableList(classWithJvmPackageNameMultifileFacadeShortNameId_);
           bitField0_ = (bitField0_ & ~0x00000020);
         }
+        result.classWithJvmPackageNameMultifileFacadeShortNameId_ = classWithJvmPackageNameMultifileFacadeShortNameId_;
+        if (((bitField0_ & 0x00000040) == 0x00000040)) {
+          classWithJvmPackageNamePackageId_ = java.util.Collections.unmodifiableList(classWithJvmPackageNamePackageId_);
+          bitField0_ = (bitField0_ & ~0x00000040);
+        }
         result.classWithJvmPackageNamePackageId_ = classWithJvmPackageNamePackageId_;
         result.bitField0_ = to_bitField0_;
         return result;
@@ -2677,11 +2870,21 @@ public final class JvmModuleProtoBuf {
             classWithJvmPackageNameShortName_.addAll(other.classWithJvmPackageNameShortName_);
           }
           
+        }
+        if (!other.classWithJvmPackageNameMultifileFacadeShortNameId_.isEmpty()) {
+          if (classWithJvmPackageNameMultifileFacadeShortNameId_.isEmpty()) {
+            classWithJvmPackageNameMultifileFacadeShortNameId_ = other.classWithJvmPackageNameMultifileFacadeShortNameId_;
+            bitField0_ = (bitField0_ & ~0x00000020);
+          } else {
+            ensureClassWithJvmPackageNameMultifileFacadeShortNameIdIsMutable();
+            classWithJvmPackageNameMultifileFacadeShortNameId_.addAll(other.classWithJvmPackageNameMultifileFacadeShortNameId_);
+          }
+          
         }
         if (!other.classWithJvmPackageNamePackageId_.isEmpty()) {
           if (classWithJvmPackageNamePackageId_.isEmpty()) {
             classWithJvmPackageNamePackageId_ = other.classWithJvmPackageNamePackageId_;
-            bitField0_ = (bitField0_ & ~0x00000020);
+            bitField0_ = (bitField0_ & ~0x00000040);
           } else {
             ensureClassWithJvmPackageNamePackageIdIsMutable();
             classWithJvmPackageNamePackageId_.addAll(other.classWithJvmPackageNamePackageId_);
@@ -2723,12 +2926,20 @@ public final class JvmModuleProtoBuf {
       private java.lang.Object packageFqName_ = "";
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public boolean hasPackageFqName() {
         return ((bitField0_ & 0x00000001) == 0x00000001);
       }
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public java.lang.String getPackageFqName() {
         java.lang.Object ref = packageFqName_;
@@ -2746,6 +2957,10 @@ public final class JvmModuleProtoBuf {
       }
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
           getPackageFqNameBytes() {
@@ -2762,6 +2977,10 @@ public final class JvmModuleProtoBuf {
       }
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public Builder setPackageFqName(
           java.lang.String value) {
@@ -2775,6 +2994,10 @@ public final class JvmModuleProtoBuf {
       }
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public Builder clearPackageFqName() {
         bitField0_ = (bitField0_ & ~0x00000001);
@@ -2784,6 +3007,10 @@ public final class JvmModuleProtoBuf {
       }
       /**
        * <code>required string package_fq_name = 1;</code>
+       *
+       * <pre>
+       * Dot-separated Kotlin FQ name of the package.
+       * </pre>
        */
       public Builder setPackageFqNameBytes(
           org.jetbrains.kotlin.protobuf.ByteString value) {
@@ -2809,7 +3036,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -2822,7 +3050,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public int getShortClassNameCount() {
@@ -2834,7 +3063,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public java.lang.String getShortClassName(int index) {
@@ -2846,7 +3076,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
@@ -2859,7 +3090,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public Builder setShortClassName(
@@ -2878,7 +3110,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public Builder addShortClassName(
@@ -2897,7 +3130,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public Builder addAllShortClassName(
@@ -2914,7 +3148,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public Builder clearShortClassName() {
@@ -2929,7 +3164,8 @@ public final class JvmModuleProtoBuf {
        * <pre>
        * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
        * (multi-file facades are not present in this list, they are defined below). Only files whose JVM package name is equal to the
-       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here.
+       * Kotlin package name (i.e. it has not been changed with &#64;JvmPackageName) are listed here, the rest are listed in
+       * class_with_jvm_package_name_short_name.
        * </pre>
        */
       public Builder addShortClassNameBytes(
@@ -3063,6 +3299,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -3074,6 +3313,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public int getMultifileFacadeShortNameCount() {
@@ -3084,6 +3326,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public java.lang.String getMultifileFacadeShortName(int index) {
@@ -3094,6 +3339,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
@@ -3105,6 +3353,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public Builder setMultifileFacadeShortName(
@@ -3122,6 +3373,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public Builder addMultifileFacadeShortName(
@@ -3139,6 +3393,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public Builder addAllMultifileFacadeShortName(
@@ -3154,6 +3411,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public Builder clearMultifileFacadeShortName() {
@@ -3167,6 +3427,9 @@ public final class JvmModuleProtoBuf {
        *
        * <pre>
        * Short names of multi-file facades, used in multifile_facade_short_name_id to store the part -&gt; facade mapping.
+       * The package name of the multi-file facade is package_fq_name if this multi-file facade is not affected by &#64;JvmPackageName,
+       * and the JVM package name of any multi-file part otherwise. Note that in the latter case, all parts must have the same JVM package name,
+       * otherwise behavior is unspecified.
        * </pre>
        */
       public Builder addMultifileFacadeShortNameBytes(
@@ -3191,8 +3454,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -3203,8 +3466,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public int getClassWithJvmPackageNameShortNameCount() {
@@ -3214,8 +3477,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public java.lang.String getClassWithJvmPackageNameShortName(int index) {
@@ -3225,8 +3488,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
@@ -3237,8 +3500,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public Builder setClassWithJvmPackageNameShortName(
@@ -3255,8 +3518,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public Builder addClassWithJvmPackageNameShortName(
@@ -3273,8 +3536,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public Builder addAllClassWithJvmPackageNameShortName(
@@ -3289,8 +3552,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public Builder clearClassWithJvmPackageNameShortName() {
@@ -3303,8 +3566,8 @@ public final class JvmModuleProtoBuf {
        * <code>repeated string class_with_jvm_package_name_short_name = 5;</code>
        *
        * <pre>
-       * Short names of files (single file facades), whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
-       * The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
+       * Short names of files (single file facades and multi-file _parts_), whose JVM package differs from the Kotlin package because of
+       * &#64;JvmPackageName. The JVM package name of each file is stored at the same index in class_with_jvm_package_name_package_id.
        * </pre>
        */
       public Builder addClassWithJvmPackageNameShortNameBytes(
@@ -3318,11 +3581,133 @@ public final class JvmModuleProtoBuf {
         return this;
       }
 
+      private java.util.List<java.lang.Integer> classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.emptyList();
+      private void ensureClassWithJvmPackageNameMultifileFacadeShortNameIdIsMutable() {
+        if (!((bitField0_ & 0x00000020) == 0x00000020)) {
+          classWithJvmPackageNameMultifileFacadeShortNameId_ = new java.util.ArrayList<java.lang.Integer>(classWithJvmPackageNameMultifileFacadeShortNameId_);
+          bitField0_ |= 0x00000020;
+         }
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public java.util.List<java.lang.Integer>
+          getClassWithJvmPackageNameMultifileFacadeShortNameIdList() {
+        return java.util.Collections.unmodifiableList(classWithJvmPackageNameMultifileFacadeShortNameId_);
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public int getClassWithJvmPackageNameMultifileFacadeShortNameIdCount() {
+        return classWithJvmPackageNameMultifileFacadeShortNameId_.size();
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public int getClassWithJvmPackageNameMultifileFacadeShortNameId(int index) {
+        return classWithJvmPackageNameMultifileFacadeShortNameId_.get(index);
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public Builder setClassWithJvmPackageNameMultifileFacadeShortNameId(
+          int index, int value) {
+        ensureClassWithJvmPackageNameMultifileFacadeShortNameIdIsMutable();
+        classWithJvmPackageNameMultifileFacadeShortNameId_.set(index, value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public Builder addClassWithJvmPackageNameMultifileFacadeShortNameId(int value) {
+        ensureClassWithJvmPackageNameMultifileFacadeShortNameIdIsMutable();
+        classWithJvmPackageNameMultifileFacadeShortNameId_.add(value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public Builder addAllClassWithJvmPackageNameMultifileFacadeShortNameId(
+          java.lang.Iterable<? extends java.lang.Integer> values) {
+        ensureClassWithJvmPackageNameMultifileFacadeShortNameIdIsMutable();
+        org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+            values, classWithJvmPackageNameMultifileFacadeShortNameId_);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 class_with_jvm_package_name_multifile_facade_short_name_id = 7 [packed = true];</code>
+       *
+       * <pre>
+       * This list is an addition to class_with_jvm_package_name_short_name exactly almost in the same way as
+       * multifile_facade_short_name_id is an addition to short_class_name. The only difference is that this list contains _full_ internal
+       * names of multi-file facades whose JVM package differs from the Kotlin package because of &#64;JvmPackageName.
+       * For each name in class_with_jvm_package_name_short_name, index of the name of the corresponding multi-file facade class in
+       * multifile_facade_short_name + 1, or 0 if the class is not a multi-file part.
+       * </pre>
+       */
+      public Builder clearClassWithJvmPackageNameMultifileFacadeShortNameId() {
+        classWithJvmPackageNameMultifileFacadeShortNameId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000020);
+        
+        return this;
+      }
+
       private java.util.List<java.lang.Integer> classWithJvmPackageNamePackageId_ = java.util.Collections.emptyList();
       private void ensureClassWithJvmPackageNamePackageIdIsMutable() {
-        if (!((bitField0_ & 0x00000020) == 0x00000020)) {
+        if (!((bitField0_ & 0x00000040) == 0x00000040)) {
           classWithJvmPackageNamePackageId_ = new java.util.ArrayList<java.lang.Integer>(classWithJvmPackageNamePackageId_);
-          bitField0_ |= 0x00000020;
+          bitField0_ |= 0x00000040;
          }
       }
       /**
@@ -3435,7 +3820,7 @@ public final class JvmModuleProtoBuf {
        */
       public Builder clearClassWithJvmPackageNamePackageId() {
         classWithJvmPackageNamePackageId_ = java.util.Collections.emptyList();
-        bitField0_ = (bitField0_ & ~0x00000020);
+        bitField0_ = (bitField0_ & ~0x00000040);
         
         return this;
       }

core/metadata.jvm/src/org/jetbrains/kotlin/metadata/jvm/deserialization/JvmMetadataVersion.kt

@@ -27,7 +27,7 @@ class JvmMetadataVersion(versionArray: IntArray, val isStrictSemantics: Boolean)
 
     companion object {
         @JvmField
-        val INSTANCE = JvmMetadataVersion(1, 1, 14)
+        val INSTANCE = JvmMetadataVersion(1, 1, 15)
 
         @JvmField
         val INVALID_VERSION = JvmMetadataVersion()

core/metadata.jvm/src/org/jetbrains/kotlin/metadata/jvm/deserialization/ModuleMapping.kt

@@ -75,10 +75,12 @@ class ModuleMapping private constructor(
                 val packageParts = result.getOrPut(packageFqName) { PackageParts(packageFqName) }
 
                 for ((index, partShortName) in proto.shortClassNameList.withIndex()) {
-                    val multifileFacadeId = proto.multifileFacadeShortNameIdList.getOrNull(index)?.minus(1)
-                    val facadeShortName = multifileFacadeId?.let(proto.multifileFacadeShortNameList::getOrNull)
-                    val facadeInternalName = facadeShortName?.let { internalNameOf(packageFqName, it) }
-                    packageParts.addPart(internalNameOf(packageFqName, partShortName), facadeInternalName)
+                    packageParts.addPart(
+                        internalNameOf(packageFqName, partShortName),
+                        loadMultiFileFacadeInternalName(
+                            proto.multifileFacadeShortNameIdList, proto.multifileFacadeShortNameList, index, packageFqName
+                        )
+                    )
                 }
 
                 if (isJvmPackageNameSupported) {
@@ -87,7 +89,16 @@ class ModuleMapping private constructor(
                             ?: proto.classWithJvmPackageNamePackageIdList.lastOrNull()
                             ?: continue
                         val jvmPackageName = moduleProto.jvmPackageNameList.getOrNull(packageId) ?: continue
-                        packageParts.addPart(internalNameOf(jvmPackageName, partShortName), null)
+
+                        packageParts.addPart(
+                            internalNameOf(jvmPackageName, partShortName),
+                            loadMultiFileFacadeInternalName(
+                                proto.classWithJvmPackageNameMultifileFacadeShortNameIdList,
+                                proto.multifileFacadeShortNameList,
+                                index,
+                                jvmPackageName
+                            )
+                        )
                     }
                 }
             }
@@ -103,6 +114,17 @@ class ModuleMapping private constructor(
 
             return ModuleMapping(result, BinaryModuleData(annotations), debugName)
         }
+
+        private fun loadMultiFileFacadeInternalName(
+            multifileFacadeIds: List<Int>,
+            multifileFacadeShortNames: List<String>,
+            index: Int,
+            packageFqName: String
+        ): String? {
+            val multifileFacadeId = multifileFacadeIds.getOrNull(index)?.minus(1)
+            val facadeShortName = multifileFacadeId?.let(multifileFacadeShortNames::getOrNull)
+            return facadeShortName?.let { internalNameOf(packageFqName, it) }
+        }
     }
 }
 
@@ -140,9 +162,10 @@ class PackageParts(val packageFqName: String) {
                     partInternalName.packageName == packageInternalName
                 }
 
-                writePartsWithinPackage(partsWithinPackage)
-
-                writePartsOutsidePackage(partsOutsidePackage, builder)
+                val facadeNameToId = mutableMapOf<String, Int>()
+                writePartsWithinPackage(partsWithinPackage, facadeNameToId)
+                writePartsOutsidePackage(partsOutsidePackage, facadeNameToId, builder)
+                writeMultifileFacadeNames(facadeNameToId)
             })
         }
 
@@ -154,26 +177,24 @@ class PackageParts(val packageFqName: String) {
         }
     }
 
-    private fun JvmModuleProtoBuf.PackageParts.Builder.writePartsWithinPackage(parts: List<String>) {
-        val facadeNameToId = mutableMapOf<String, Int>()
+    private fun JvmModuleProtoBuf.PackageParts.Builder.writePartsWithinPackage(
+        parts: List<String>,
+        facadeNameToId: MutableMap<String, Int>
+    ) {
         for ((facadeInternalName, partInternalNames) in parts.groupBy { getMultifileFacadeName(it) }.toSortedMap(nullsLast())) {
             for (partInternalName in partInternalNames.sorted()) {
                 addShortClassName(partInternalName.className)
                 if (facadeInternalName != null) {
-                    addMultifileFacadeShortNameId(1 + facadeNameToId.getOrPut(facadeInternalName.className) { facadeNameToId.size })
+                    addMultifileFacadeShortNameId(getMultifileFacadeShortNameId(facadeInternalName, facadeNameToId))
                 }
             }
         }
-
-        for ((facadeId, facadeName) in facadeNameToId.values.zip(facadeNameToId.keys).sortedBy(Pair<Int, String>::first)) {
-            assert(facadeId == multifileFacadeShortNameCount) { "Multifile facades are loaded incorrectly: $facadeNameToId" }
-            addMultifileFacadeShortName(facadeName)
-        }
     }
 
     // Writes information about package parts which have a different JVM package from the Kotlin package (with the help of @JvmPackageName)
     private fun JvmModuleProtoBuf.PackageParts.Builder.writePartsOutsidePackage(
         parts: List<String>,
+        facadeNameToId: MutableMap<String, Int>,
         packageTableBuilder: JvmModuleProtoBuf.Module.Builder
     ) {
         val packageIds = mutableListOf<Int>()
@@ -183,9 +204,16 @@ class PackageParts(val packageFqName: String) {
                 packageTableBuilder.addJvmPackageName(packageFqName)
             }
             val packageId = packageTableBuilder.jvmPackageNameList.indexOf(packageFqName)
-            for (part in partsInPackage.map { it.className }.sorted()) {
-                addClassWithJvmPackageNameShortName(part)
-                packageIds.add(packageId)
+            for ((facadeInternalName, partInternalNames) in partsInPackage.groupBy { getMultifileFacadeName(it) }.toSortedMap(nullsLast())) {
+                for (partInternalName in partInternalNames.sorted()) {
+                    addClassWithJvmPackageNameShortName(partInternalName.className)
+                    if (facadeInternalName != null) {
+                        addClassWithJvmPackageNameMultifileFacadeShortNameId(
+                            getMultifileFacadeShortNameId(facadeInternalName, facadeNameToId)
+                        )
+                    }
+                    packageIds.add(packageId)
+                }
             }
         }
 
@@ -197,6 +225,17 @@ class PackageParts(val packageFqName: String) {
         addAllClassWithJvmPackageNamePackageId(packageIds)
     }
 
+    private fun getMultifileFacadeShortNameId(facadeInternalName: String, facadeNameToId: MutableMap<String, Int>): Int {
+        return 1 + facadeNameToId.getOrPut(facadeInternalName.className) { facadeNameToId.size }
+    }
+
+    private fun JvmModuleProtoBuf.PackageParts.Builder.writeMultifileFacadeNames(facadeNameToId: Map<String, Int>) {
+        for ((facadeId, facadeName) in facadeNameToId.values.zip(facadeNameToId.keys).sortedBy(Pair<Int, String>::first)) {
+            assert(facadeId == multifileFacadeShortNameCount) { "Multifile facades are loaded incorrectly: $facadeNameToId" }
+            addMultifileFacadeShortName(facadeName)
+        }
+    }
+
     private val String.packageName: String get() = substringBeforeLast('/', "")
     private val String.className: String get() = substringAfterLast('/')