Add KotlinVersion.IS_PRE_RELEASE and a flag to kotlin/Metadata

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

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.jvm.JvmClassName;
 
+@SuppressWarnings("PointlessBitwiseExpression")
 public final class JvmAnnotationNames {
     public static final FqName METADATA_FQ_NAME = new FqName("kotlin.Metadata");
     public static final String METADATA_DESC = "L" + JvmClassName.byFqNameWithoutInnerClasses(METADATA_FQ_NAME).getInternalName() + ";";
@@ -32,7 +33,9 @@ public final class JvmAnnotationNames {
     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 int METADATA_MULTIFILE_PARTS_INHERIT_FLAG = 1 << 0;
+    public static final int METADATA_PRE_RELEASE_FLAG = 1 << 1;
 
     public static final Name DEFAULT_ANNOTATION_MEMBER_NAME = Name.identifier("value");
 

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

@@ -16,8 +16,11 @@
 
 package org.jetbrains.kotlin.load.kotlin.header
 
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames
 import org.jetbrains.kotlin.load.java.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.load.kotlin.JvmMetadataVersion
+import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader.MultifileClassKind.DELEGATING
+import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader.MultifileClassKind.INHERITING
 
 class KotlinClassHeader(
         val kind: KotlinClassHeader.Kind,
@@ -45,27 +48,27 @@ 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]
-        }
+    enum class MultifileClassKind {
+        DELEGATING,
+        INHERITING;
     }
 
     val multifileClassName: String?
         get() = if (kind == Kind.MULTIFILE_CLASS_PART) extraString else null
 
+    // TODO: use in incremental compilation
     val multifileClassKind: MultifileClassKind?
-        get() = if (kind == Kind.MULTIFILE_CLASS || kind == Kind.MULTIFILE_CLASS_PART)
-            MultifileClassKind.getById(extraInt)
+        get() = if (kind == Kind.MULTIFILE_CLASS || kind == Kind.MULTIFILE_CLASS_PART) {
+            if ((extraInt and JvmAnnotationNames.METADATA_MULTIFILE_PARTS_INHERIT_FLAG) != 0)
+                INHERITING
+            else
+                DELEGATING
+        }
         else
             null
 
+    val isPreRelease: Boolean
+        get() = (extraInt and JvmAnnotationNames.METADATA_PRE_RELEASE_FLAG) != 0
+
     override fun toString() = "$kind version=$metadataVersion"
 }

core/runtime.jvm/src/kotlin/Metadata.kt

@@ -57,7 +57,10 @@ internal annotation class Metadata(
          */
         val xs: String = "",
         /**
-         * An extra int. For multi-file class, represents code generation scheme.
+         * An extra int. Bits of this number represent the following flags:
+         *
+         * 0 - this is a multi-file class facade or part, compiled with `-Xmultifile-parts-inherit`.
+         * 1 - this class file is compiled by a pre-release version of Kotlin and is not visible to release versions.
          */
         val xi: Int = 0
 )

core/util.runtime/src/org/jetbrains/kotlin/config/KotlinCompilerVersion.java

@@ -20,4 +20,18 @@ public class KotlinCompilerVersion {
     // The value of this constant is generated by the build script
     // DON'T MODIFY IT
     public static final String VERSION = "@snapshot@";
+
+    // True if this compiler is of a non-stable (EAP or Beta) version.
+    // Binaries produced by this compiler can not be loaded by release versions of the compiler.
+    // Change this value before and after every major release
+    public static final boolean IS_PRE_RELEASE = true;
+
+    static {
+        if (!VERSION.equals("@snapshot@") && !VERSION.contains("-") && IS_PRE_RELEASE) {
+            throw new IllegalStateException(
+                    "IS_PRE_RELEASE cannot be false for a compiler without '-' in its version.\n" +
+                    "Please change IS_PRE_RELEASE to false, commit and push this change to master"
+            );
+        }
+    }
 }