Improve ABI version from one number to "major.minor.patch"

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

@@ -16,11 +16,16 @@
 
 package org.jetbrains.kotlin.load.java;
 
-public final class AbiVersionUtil {
-    public static final int INVALID_VERSION = -1;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion;
 
-    public static boolean isAbiVersionCompatible(int abiVersion) {
-        return abiVersion == JvmAbi.VERSION;
+public final class AbiVersionUtil {
+    public static final BinaryVersion INVALID_VERSION = BinaryVersion.create(new int[0]);
+
+    public static boolean isAbiVersionCompatible(@NotNull BinaryVersion actual) {
+        // TODO: compare versions according to Semantic Versioning
+        return actual.getMajor() == JvmAbi.VERSION.getMajor() &&
+               actual.getMinor() == JvmAbi.VERSION.getMinor();
     }
 
     private AbiVersionUtil() {

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

@@ -21,13 +21,20 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.name.ClassId;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
+import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion;
 
 public final class JvmAbi {
     /**
      * This constant is used to identify binary format (class file) versions
-     * If you change class file metadata format and/or naming conventions, please increase this number
+     * If you change class file metadata format and/or naming conventions, please change this version.
+     * - Major version should be increased only when the new binary format is neither forward- nor backward compatible.
+     *   This shouldn't really ever happen at all.
+     * - Minor version should be increased when the new format is backward compatible,
+     *   i.e. the new compiler can process old class files, but the old compiler will not be able to process new class files.
+     * - Patch version can be increased freely and is only supposed to be used for debugging. Increase the patch version when you
+     *   make a change to the metadata format or the bytecode which is both forward- and backward compatible.
      */
-    public static final int VERSION = 24;
+    public static final BinaryVersion VERSION = BinaryVersion.create(0, 24, 0);
 
     public static final String TRAIT_IMPL_CLASS_NAME = "$TImpl";
     public static final String TRAIT_IMPL_SUFFIX = "$" + TRAIT_IMPL_CLASS_NAME;

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

@@ -38,7 +38,7 @@ public final class JvmAnnotationNames {
     public static final FqName KOTLIN_SIGNATURE = new FqName("kotlin.jvm.KotlinSignature");
     public static final FqName OLD_KOTLIN_SIGNATURE = new FqName("jet.runtime.typeinfo.KotlinSignature");
 
-    public static final String ABI_VERSION_FIELD_NAME = "abiVersion";
+    public static final String VERSION_FIELD_NAME = "version";
     public static final String KIND_FIELD_NAME = "kind";
     public static final String FILE_PART_CLASS_NAMES_FIELD_NAME = "filePartClassNames";
     public static final String MULTIFILE_CLASS_NAME_FIELD_NAME = "multifileClassName";
@@ -114,6 +114,8 @@ public final class JvmAnnotationNames {
     @Deprecated
     public static final FqName OLD_KOTLIN_TRAIT_IMPL = new FqName("jet.KotlinTraitImpl");
 
+    public static final String OLD_ABI_VERSION_FIELD_NAME = "abiVersion";
+
     // When these annotations appear on a declaration, they are copied to the _type_ of the declaration, becoming type annotations
     // See also DescriptorRendererOptions#excludedTypeAnnotationClasses
     public static final Set<FqName> ANNOTATIONS_COPIED_TO_TYPES = KotlinPackage.setOf(

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

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.load.kotlin
 
 import org.jetbrains.kotlin.load.java.AbiVersionUtil
+import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion
 import org.jetbrains.kotlin.serialization.jvm.JvmPackageTable
 import java.io.ByteArrayInputStream
 import java.io.DataInputStream
@@ -28,19 +29,27 @@ public class ModuleMapping private constructor(val packageFqName2Parts: Map<Stri
     }
 
     companion object {
-        public val MAPPING_FILE_EXT: String = "kotlin_module";
+        public val MAPPING_FILE_EXT: String = "kotlin_module"
 
         public val EMPTY: ModuleMapping = ModuleMapping(emptyMap())
 
-        fun create(protoWithAbi: ByteArray? = null): ModuleMapping {
-            if (protoWithAbi == null) {
+        fun create(proto: ByteArray? = null): ModuleMapping {
+            if (proto == null) {
                 return EMPTY
             }
 
-            val inputStream = DataInputStream(ByteArrayInputStream(protoWithAbi))
-            val intCount = inputStream.readInt()
-            assert(intCount == 1, {"Expected one int value for abi version, but: $intCount"})
-            val abiVersion = Integer.valueOf(inputStream.readInt());
+            val inputStream = DataInputStream(ByteArrayInputStream(proto))
+            val size = inputStream.readInt()
+
+            val abiVersion =
+                    if (size == 1) {
+                        // TODO: this is a temporary workaround, drop after M13
+                        BinaryVersion.create(0, inputStream.readInt(), 0)
+                    }
+                    else {
+                        BinaryVersion.create((0..size - 1).map { inputStream.readInt() }.toIntArray())
+                    }
+
             if (AbiVersionUtil.isAbiVersionCompatible(abiVersion)) {
                 val parseFrom = JvmPackageTable.PackageTable.parseFrom(inputStream)
                 if (parseFrom != null) {
@@ -55,6 +64,7 @@ public class ModuleMapping private constructor(val packageFqName2Parts: Map<Stri
                     return ModuleMapping(packageFqNameParts)
                 }
             }
+
             return EMPTY
         }
     }

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

@@ -16,13 +16,14 @@
 
 package org.jetbrains.kotlin.load.kotlin.header
 
+import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion
 import org.jetbrains.kotlin.load.java.AbiVersionUtil
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinClass
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinSyntheticClass
 
 public class KotlinClassHeader(
         public val kind: KotlinClassHeader.Kind,
-        public val version: Int,
+        public val version: BinaryVersion,
         public val annotationData: Array<String>?,
         public val classKind: KotlinClass.Kind?,
         public val syntheticClassKind: KotlinSyntheticClass.Kind?,

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

@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.load.java.AbiVersionUtil;
 import org.jetbrains.kotlin.name.ClassId;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.jvm.JvmClassName;
+import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -59,7 +60,7 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
         OLD_DEPRECATED_ANNOTATIONS_KINDS.put(JvmClassName.byFqNameWithoutInnerClasses(OLD_KOTLIN_TRAIT_IMPL), SYNTHETIC_CLASS);
     }
 
-    private int version = AbiVersionUtil.INVALID_VERSION;
+    private BinaryVersion version = AbiVersionUtil.INVALID_VERSION;
     private String multifileClassName = null;
     private String[] filePartClassNames = null;
     private String[] annotationData = null;
@@ -151,12 +152,18 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
 
         @Override
         public void visit(@Nullable Name name, @Nullable Object value) {
-            if (name != null) {
-                if (name.asString().equals(ABI_VERSION_FIELD_NAME)) {
-                    version = value instanceof Integer ? (Integer) value : AbiVersionUtil.INVALID_VERSION;
-                }
-                else if (name.asString().equals(MULTIFILE_CLASS_NAME_FIELD_NAME)) {
-                    multifileClassName = value instanceof String ? (String) value : null;
+            if (name == null) return;
+
+            String string = name.asString();
+            if (VERSION_FIELD_NAME.equals(string)) {
+                version = value instanceof int[] ? BinaryVersion.create((int[]) value) : AbiVersionUtil.INVALID_VERSION;
+            }
+            else if (MULTIFILE_CLASS_NAME_FIELD_NAME.equals(string)) {
+                multifileClassName = value instanceof String ? (String) value : null;
+            }
+            else if (OLD_ABI_VERSION_FIELD_NAME.equals(string)) {
+                if (version == AbiVersionUtil.INVALID_VERSION && value instanceof Integer && (Integer) value > 0) {
+                    version = BinaryVersion.create(0, (Integer) value, 0);
                 }
             }
         }