Remove JvmBytecodeBinaryVersion from the compiler code

Move it to build-common where it's still used in incremental compilation
caches, and simplify a bit. In the future, it'll make sense to remove it
completely and to avoid writing it to caches. In this commit, I don't do
that to prevent the IC cache version to be updated, causing rebuilds for
all JPS projects.

 #KT-41758

build-common/src/org/jetbrains/kotlin/build/JvmBuildMetaInfo.kt

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.build
 
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion
 
 /**

build-common/src/org/jetbrains/kotlin/build/JvmBytecodeBinaryVersion.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.build
+
+/**
+ * Bytecode version was in the Kotlin metadata ([Metadata.bytecodeVersion]) since 1.0, but it was never used meaningfully in the compiler,
+ * outside of one very special case regarding experimental coroutines, which is now obsolete. It is still used in incremental compilation
+ * caches though. We should probably just pretend that the bytecode version of any Kotlin file from now on is equal to the latest observed
+ * bytecode version, `1.0.3` (see [INSTANCE]).
+ */
+class JvmBytecodeBinaryVersion(vararg numbers: Int) {
+    val major: Int = numbers.getOrNull(0) ?: -1
+    val minor: Int = numbers.getOrNull(1) ?: -1
+    val patch: Int = numbers.getOrNull(2) ?: -1
+
+    override fun toString(): String = buildString {
+        append(major)
+        if (minor != -1) {
+            append(".$minor")
+            if (patch != -1) append(".$patch")
+        }
+    }
+
+    companion object {
+        @JvmField
+        val INSTANCE = JvmBytecodeBinaryVersion(1, 0, 3)
+    }
+}

core/compiler.common.jvm/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.java

@@ -30,7 +30,6 @@ public final class JvmAnnotationNames {
     public static final String METADATA_DESC = "L" + JvmClassName.byFqNameWithoutInnerClasses(METADATA_FQ_NAME).getInternalName() + ";";
 
     public static final String METADATA_VERSION_FIELD_NAME = "mv";
-    public static final String BYTECODE_VERSION_FIELD_NAME = "bv";
     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";

core/descriptors.jvm/src/org/jetbrains/kotlin/load/kotlin/header/ReadKotlinClassHeaderAnnotationVisitor.java

@@ -20,7 +20,6 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.SourceElement;
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames;
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion;
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion;
 import org.jetbrains.kotlin.name.ClassId;
 import org.jetbrains.kotlin.name.FqName;
@@ -51,7 +50,6 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
     }
 
     private int[] metadataVersionArray = null;
-    private JvmBytecodeBinaryVersion bytecodeVersion = null;
     private String extraString = null;
     private int extraInt = 0;
     private String packageName = null;
@@ -79,17 +77,7 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
             return null;
         }
 
-        return new KotlinClassHeader(
-                headerKind,
-                metadataVersion,
-                bytecodeVersion != null ? bytecodeVersion : JvmBytecodeBinaryVersion.INSTANCE,
-                data,
-                incompatibleData,
-                strings,
-                extraString,
-                extraInt,
-                packageName
-        );
+        return new KotlinClassHeader(headerKind, metadataVersion, data, incompatibleData, strings, extraString, extraInt, packageName);
     }
 
     private boolean shouldHaveData() {
@@ -142,11 +130,6 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
                     metadataVersionArray = (int[]) value;
                 }
             }
-            else if (BYTECODE_VERSION_FIELD_NAME.equals(string)) {
-                if (value instanceof int[]) {
-                    bytecodeVersion = new JvmBytecodeBinaryVersion((int[]) value);
-                }
-            }
             else if (METADATA_EXTRA_STRING_FIELD_NAME.equals(string)) {
                 if (value instanceof String) {
                     extraString = (String) value;
@@ -227,11 +210,6 @@ public class ReadKotlinClassHeaderAnnotationVisitor implements AnnotationVisitor
             if ("version".equals(string)) {
                 if (value instanceof int[]) {
                     metadataVersionArray = (int[]) value;
-
-                    // If there's no bytecode binary version in the class file, we assume it to be equal to the metadata version
-                    if (bytecodeVersion == null) {
-                        bytecodeVersion = new JvmBytecodeBinaryVersion((int[]) value);
-                    }
                 }
             }
             else if ("multifileClassName".equals(string)) {

core/deserialization.common.jvm/src/org/jetbrains/kotlin/load/kotlin/header/KotlinClassHeader.kt

@@ -8,13 +8,11 @@ package org.jetbrains.kotlin.load.kotlin.header
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.*
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader.MultifileClassKind.DELEGATING
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader.MultifileClassKind.INHERITING
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion
 
 class KotlinClassHeader(
     val kind: Kind,
     val metadataVersion: JvmMetadataVersion,
-    val bytecodeVersion: JvmBytecodeBinaryVersion,
     val data: Array<String>?,
     val incompatibleData: Array<String>?,
     val strings: Array<String>?,

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

@@ -1,21 +0,0 @@
-/*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.metadata.jvm.deserialization
-
-import org.jetbrains.kotlin.metadata.deserialization.BinaryVersion
-
-/**
- * The version of conventions used in bytecode of generated .class files, such as default method naming & signatures,
- * internal member name mangling specifics, property getter/setter names, etc.
- */
-class JvmBytecodeBinaryVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
-    override fun isCompatible() = this.isCompatibleTo(INSTANCE)
-
-    companion object {
-        @JvmField
-        val INSTANCE = JvmBytecodeBinaryVersion(1, 0, 3)
-    }
-}

jps-plugin/jps-tests/test/org/jetbrains/kotlin/jps/incremental/CacheVersionTest.kt

@@ -5,7 +5,7 @@
 
 package org.jetbrains.kotlin.jps.incremental
 
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion
+import org.jetbrains.kotlin.build.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion
 import org.junit.Assert.assertEquals
 import org.junit.Test
@@ -54,4 +54,4 @@ class CacheVersionTest {
             ).toString()
         )
     }
-}
+}

jps-plugin/src/org/jetbrains/kotlin/jps/incremental/CacheVersionManager.kt

@@ -6,7 +6,7 @@
 package org.jetbrains.kotlin.jps.incremental
 
 import org.jetbrains.annotations.TestOnly
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion
+import org.jetbrains.kotlin.build.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion
 import java.io.File
 import java.io.IOException
@@ -79,4 +79,4 @@ data class CacheVersion(val intValue: Int) {
         )
 
     override fun toString(): String = "CacheVersion(caches: $own, bytecode: $bytecode, metadata: $metadata)"
-}
+}

libraries/kotlinx-metadata/jvm/src/kotlinx/metadata/jvm/KotlinClassHeader.kt

@@ -7,7 +7,6 @@
 
 package kotlinx.metadata.jvm
 
-import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmBytecodeBinaryVersion
 import org.jetbrains.kotlin.metadata.jvm.deserialization.JvmMetadataVersion
 
 /**
@@ -175,6 +174,6 @@ constructor(
             level = DeprecationLevel.ERROR
         )
         @JvmField
-        val COMPATIBLE_BYTECODE_VERSION = JvmBytecodeBinaryVersion.INSTANCE.toArray().copyOf()
+        val COMPATIBLE_BYTECODE_VERSION = intArrayOf(1, 0, 3)
     }
 }