KT-11410: write multifile class code generation scheme to extra field (xi) in kotlin.Metadata.

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.java

@@ -29,7 +29,10 @@ public final class JvmAnnotationNames {
     public static final String KIND_FIELD_NAME = "k";
     public static final String METADATA_DATA_FIELD_NAME = "d1";
     public static final String METADATA_STRINGS_FIELD_NAME = "d2";
-    public static final String METADATA_MULTIFILE_CLASS_NAME_FIELD_NAME = "xs";
+    public static final String METADATA_EXTRA_STRING_FIELD_NAME = "xs";
+    public static final String METADATA_MULTIFILE_CLASS_NAME_FIELD_NAME = METADATA_EXTRA_STRING_FIELD_NAME;
+    public static final String METADATA_EXTRA_INT_FIELD_NAME = "xi";
+    public static final String METADATA_MULTIFILE_CLASS_KIND_FIELD_NAME = METADATA_EXTRA_INT_FIELD_NAME;
 
     public static final Name DEFAULT_ANNOTATION_MEMBER_NAME = Name.identifier("value");
 

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/JvmMetadataVersion.kt

@@ -32,7 +32,7 @@ class JvmMetadataVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
         var skipCheck: Boolean = false
 
         @JvmField
-        val INSTANCE = JvmMetadataVersion(1, 1, 0)
+        val INSTANCE = JvmMetadataVersion(1, 1, 1)
 
         @JvmField
         val INVALID_VERSION = JvmMetadataVersion()

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/KotlinClassHeader.kt

@@ -25,7 +25,8 @@ class KotlinClassHeader(
         val bytecodeVersion: JvmBytecodeBinaryVersion,
         val data: Array<String>?,
         val strings: Array<String>?,
-        val multifileClassName: String?
+        val extraString: String?,
+        val extraInt: Int
 ) {
     // See kotlin.Metadata
     enum class Kind(val id: Int) {
@@ -44,5 +45,27 @@ class KotlinClassHeader(
         }
     }
 
+    // See kotlin.Metadata
+    enum class MultifileClassKind(val id: Int) {
+        DELEGATING(0),
+        INHERITING(1);
+
+        companion object {
+            private val entryById = values().associateBy(MultifileClassKind::id)
+
+            @JvmStatic
+            fun getById(id: Int) = entryById[id]
+        }
+    }
+
+    val multifileClassName: String?
+        get() = if (kind == Kind.MULTIFILE_CLASS_PART) extraString else null
+
+    val multifileClassKind: MultifileClassKind?
+        get() = if (kind == Kind.MULTIFILE_CLASS || kind == Kind.MULTIFILE_CLASS_PART)
+            MultifileClassKind.getById(extraInt)
+        else
+            null
+
     override fun toString() = "$kind version=$metadataVersion"
 }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/ReadKotlinClassHeaderAnnotationVisitor.java

@@ -50,7 +50,8 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
 
     private JvmMetadataVersion metadataVersion = null;
     private JvmBytecodeBinaryVersion bytecodeVersion = null;
-    private String multifileClassName = null;
+    private String extraString = null;
+    private int extraInt = 0;
     private String[] data = null;
     private String[] strings = null;
     private KotlinClassHeader.Kind headerKind = null;
@@ -76,7 +77,8 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
                 bytecodeVersion != null ? bytecodeVersion : JvmBytecodeBinaryVersion.INVALID_VERSION,
                 data,
                 strings,
-                multifileClassName
+                extraString,
+                extraInt
         );
     }
 
@@ -135,9 +137,14 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
                     bytecodeVersion = new JvmBytecodeBinaryVersion((int[]) value);
                 }
             }
-            else if (METADATA_MULTIFILE_CLASS_NAME_FIELD_NAME.equals(string)) {
+            else if (METADATA_EXTRA_STRING_FIELD_NAME.equals(string)) {
                 if (value instanceof String) {
-                    multifileClassName = (String) value;
+                    extraString = (String) value;
+                }
+            }
+            else if (METADATA_EXTRA_INT_FIELD_NAME.equals(string)) {
+                if (value instanceof Integer) {
+                    extraInt = (Integer) value;
                 }
             }
         }
@@ -209,7 +216,7 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
                 }
             }
             else if ("multifileClassName".equals(string)) {
-                multifileClassName = value instanceof String ? (String) value : null;
+                extraString = value instanceof String ? (String) value : null;
             }
         }