Fix for KT-16614: Report inability to inline 1.8 bytecode into 1.6 bytecode as an error, no as an exception

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/AnonymousObjectTransformer.java

@@ -66,7 +66,6 @@ public class AnonymousObjectTransformer extends ObjectTransformer<AnonymousObjec
         createClassReader().accept(new ClassVisitor(InlineCodegenUtil.API, classBuilder.getVisitor()) {
             @Override
             public void visit(int version, int access, @NotNull String name, String signature, String superName, String[] interfaces) {
-                InlineCodegenUtil.assertVersionNotGreaterThanGeneratedOne(version, name, inliningContext.state);
                 classBuilder.defineClass(null, version, access, name, signature, superName, interfaces);
                 if(CoroutineCodegenUtilKt.COROUTINE_IMPL_ASM_TYPE.getInternalName().equals(superName)) {
                     inliningContext.setContinuation(true);

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/InlineCodegen.java

@@ -38,6 +38,7 @@ import org.jetbrains.kotlin.load.kotlin.incremental.components.IncrementalCache;
 import org.jetbrains.kotlin.name.ClassId;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
+import org.jetbrains.kotlin.renderer.DescriptorRenderer;
 import org.jetbrains.kotlin.resolve.BindingContext;
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
@@ -202,7 +203,7 @@ public class InlineCodegen extends CallGenerator {
         MethodNode node = nodeAndSmap != null ? nodeAndSmap.getNode() : null;
         throw new CompilationException(
                 "Couldn't inline method call '" + functionDescriptor.getName() + "' into\n" +
-                contextDescriptor + "\n" +
+                DescriptorRenderer.DEBUG_TEXT.render(contextDescriptor) + "\n" +
                 (element != null ? element.getText() : "<no source>") +
                 (generateNodeText ? ("\nCause: " + InlineCodegenUtil.getNodeText(node)) : ""),
                 e, callElement
@@ -321,7 +322,7 @@ public class InlineCodegen extends CallGenerator {
                 }
             });
 
-            return InlineCodegenUtil.getMethodNode(bytes, asmMethod.getName(), asmMethod.getDescriptor(), classId, state);
+            return InlineCodegenUtil.getMethodNode(bytes, asmMethod.getName(), asmMethod.getDescriptor(), classId);
         }
 
         assert callableDescriptor instanceof DeserializedCallableMemberDescriptor : "Not a deserialized function or proper: " + callableDescriptor;
@@ -348,7 +349,7 @@ public class InlineCodegen extends CallGenerator {
         });
 
 
-        return InlineCodegenUtil.getMethodNode(bytes, asmMethod.getName(), asmMethod.getDescriptor(), containerId, state);
+        return InlineCodegenUtil.getMethodNode(bytes, asmMethod.getName(), asmMethod.getDescriptor(), containerId);
     }
 
     @NotNull

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/InlineCodegenUtil.java

@@ -92,8 +92,7 @@ public class InlineCodegenUtil {
             byte[] classData,
             final String methodName,
             final String methodDescriptor,
-            ClassId classId,
-            final @NotNull GenerationState state
+            ClassId classId
     ) {
         ClassReader cr = new ClassReader(classData);
         final MethodNode[] node = new MethodNode[1];
@@ -103,10 +102,6 @@ public class InlineCodegenUtil {
         lines[1] = Integer.MIN_VALUE;
         //noinspection PointlessBitwiseExpression
         cr.accept(new ClassVisitor(API) {
-            @Override
-            public void visit(int version, int access, @NotNull String name, String signature, String superName, String[] interfaces) {
-                assertVersionNotGreaterThanGeneratedOne(version, name, state);
-            }
 
             @Override
             public void visitSource(String source, String debug) {
@@ -151,16 +146,6 @@ public class InlineCodegenUtil {
         return new SMAPAndMethodNode(node[0], smap);
     }
 
-    public static void assertVersionNotGreaterThanGeneratedOne(int version, String internalName, @NotNull GenerationState state) {
-        // TODO: report a proper diagnostic
-        if (version > state.getClassFileVersion() && !"true".equals(System.getProperty("kotlin.skip.bytecode.version.check"))) {
-            throw new UnsupportedOperationException(
-                    "Cannot inline bytecode of class " + internalName + " which has version " + version + ". " +
-                    "This compiler can only inline Java 1.6 bytecode (version " + Opcodes.V1_6 + ")"
-            );
-        }
-    }
-
     public static void initDefaultSourceMappingIfNeeded(
             @NotNull CodegenContext context, @NotNull MemberCodegen codegen, @NotNull GenerationState state
     ) {

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/ObjectTransformer.kt

@@ -66,7 +66,6 @@ class WhenMappingTransformer(
         val fieldNode = transformationInfo.fieldNode
         classReader.accept(object : ClassVisitor(InlineCodegenUtil.API, classBuilder.visitor) {
             override fun visit(version: Int, access: Int, name: String, signature: String?, superName: String, interfaces: Array<String>) {
-                InlineCodegenUtil.assertVersionNotGreaterThanGeneratedOne(version, name, state)
                 classBuilder.defineClass(null, version, access, name, signature, superName, interfaces)
             }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/state/GenerationState.kt

@@ -123,7 +123,8 @@ class GenerationState @JvmOverloads constructor(
         extraJvmDiagnosticsTrace.bindingContext.diagnostics
     }
 
-    val isJvm8Target: Boolean = configuration.get(JVMConfigurationKeys.JVM_TARGET) == JvmTarget.JVM_1_8
+    val target = configuration.get(JVMConfigurationKeys.JVM_TARGET) ?: JvmTarget.DEFAULT
+    val isJvm8Target: Boolean = target == JvmTarget.JVM_1_8
     val isJvm8TargetWithDefaults: Boolean =  isJvm8Target && configuration.getBoolean(JVMConfigurationKeys.JVM8_TARGET_WITH_DEFAULTS)
     val generateDefaultImplsForJvm8: Boolean = configuration.getBoolean(JVMConfigurationKeys.INTERFACE_COMPATIBILITY)
 
@@ -162,7 +163,7 @@ class GenerationState @JvmOverloads constructor(
 
     val rootContext: CodegenContext<*> = RootContext(this)
 
-    val classFileVersion: Int = if (isJvm8Target) Opcodes.V1_8 else Opcodes.V1_6
+    val classFileVersion: Int = target.bytecodeVersion
 
     val generateParametersMetadata: Boolean = configuration.getBoolean(JVMConfigurationKeys.PARAMETERS_METADATA)
 

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

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.jvm.checkers
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.JVMConfigurationKeys
+import org.jetbrains.kotlin.config.JvmTarget
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.ClassOrPackageFragmentDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.load.kotlin.FileBasedKotlinClass
+import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinaryPackageSourceElement
+import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinarySourceElement
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.calls.checkers.CallChecker
+import org.jetbrains.kotlin.resolve.calls.checkers.CallCheckerContext
+import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.inline.InlineUtil
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
+import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedCallableMemberDescriptor
+
+class InlinePlatformCompatibilityChecker: CallChecker {
+
+    private val doCheck = doCheck()
+
+    override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
+        if (!doCheck) return
+
+        val resultingDescriptor = resolvedCall.resultingDescriptor as? CallableMemberDescriptor ?: return
+        if (!InlineUtil.isInline(resultingDescriptor)) {
+            if (resultingDescriptor is PropertyDescriptor && InlineUtil.isInline(resultingDescriptor.getter)) {
+            //TODO: we should distinguish setter usage from getter one, now we could report wrong diagnostic on non-inline setter
+            //var prop: Int
+            // inline get
+            // set
+            //
+            // prop  - resolved call with property descriptor and we should report error
+            // prop = 1 - resolved call with setter for whole expression and property descriptor for left part,
+            //              so we couldn't distinguish is this expression for setter or for getter and will report wrong diagnostic
+            }
+            else {
+                return
+            }
+        }
+
+        val propertyOrFun = DescriptorUtils.getDirectMember(resultingDescriptor)
+        val inliningBytecodeVersion = getBytecodeVersionIfDeserializedDescriptor(propertyOrFun) ?: return
+
+        val compilingTarget = context.compilerConfiguration[JVMConfigurationKeys.JVM_TARGET] ?: JvmTarget.DEFAULT
+        val compilingBytecodeVersion = compilingTarget.bytecodeVersion
+        if (compilingBytecodeVersion < inliningBytecodeVersion) {
+            context.trace.report(ErrorsJvm.INLINE_FROM_HIGHER_PLATFORM.on(reportOn, JvmTarget.getDescription(inliningBytecodeVersion), JvmTarget.getDescription(compilingBytecodeVersion)))
+        }
+    }
+
+    companion object {
+
+        fun doCheck() = "true" != System.getProperty("kotlin.skip.bytecode.version.check")
+
+        fun getBytecodeVersionIfDeserializedDescriptor(funOrProperty: DeclarationDescriptor): Int? {
+            if (funOrProperty !is DeserializedCallableMemberDescriptor) return null
+
+            val containingDeclaration = funOrProperty.containingDeclaration as ClassOrPackageFragmentDescriptor
+
+            val source = containingDeclaration.source
+            val binaryClass =
+                    when (source) {
+                        is KotlinJvmBinarySourceElement -> source.binaryClass
+                        is KotlinJvmBinaryPackageSourceElement -> source.getContainingBinaryClass(funOrProperty)
+                        else -> null
+                    } as? FileBasedKotlinClass ?: return null
+
+            return binaryClass.classVersion
+        }
+    }
+}
+

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

@@ -115,6 +115,8 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
 
         MAP.put(ErrorsJvm.DEFAULT_METHOD_CALL_FROM_JAVA6_TARGET, "Super calls to Java default methods are deprecated in JVM target 1.6. Recompile with '-jvm-target 1.8'");
         MAP.put(ErrorsJvm.INTERFACE_STATIC_METHOD_CALL_FROM_JAVA6_TARGET, "Calls to static methods in Java interfaces are deprecated in JVM target 1.6. Recompile with '-jvm-target 1.8'");
+
+        MAP.put(ErrorsJvm.INLINE_FROM_HIGHER_PLATFORM, "Cannot inline bytecode built with {0} into bytecode that is being built with {1}. Please specify proper ''-jvm-target'' option", Renderers.TO_STRING, Renderers.TO_STRING);
     }
 
     @NotNull

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

@@ -92,6 +92,8 @@ public interface ErrorsJvm {
     DiagnosticFactory0<PsiElement> DEFAULT_METHOD_CALL_FROM_JAVA6_TARGET = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory0<PsiElement> INTERFACE_STATIC_METHOD_CALL_FROM_JAVA6_TARGET = DiagnosticFactory0.create(WARNING);
 
+    DiagnosticFactory2<PsiElement, String, String> INLINE_FROM_HIGHER_PLATFORM = DiagnosticFactory2.create(ERROR);
+
     @SuppressWarnings("UnusedDeclaration")
     Object _initializer = new Object() {
         {

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/platform/JvmPlatformConfigurator.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.container.useImpl
 import org.jetbrains.kotlin.container.useInstance
 import org.jetbrains.kotlin.platform.JavaToKotlinClassMap
 import org.jetbrains.kotlin.resolve.PlatformConfigurator
+import org.jetbrains.kotlin.resolve.calls.checkers.InlineCheckerWrapper
 import org.jetbrains.kotlin.resolve.calls.checkers.ReifiedTypeParameterSubstitutionChecker
 import org.jetbrains.kotlin.resolve.checkers.HeaderImplDeclarationChecker
 import org.jetbrains.kotlin.resolve.checkers.MissingDependencyClassChecker
@@ -55,7 +56,8 @@ object JvmPlatformConfigurator : PlatformConfigurator(
                 UnsupportedSyntheticCallableReferenceChecker(),
                 SuperCallWithDefaultArgumentsChecker(),
                 ProtectedSyntheticExtensionCallChecker,
-                ReifiedTypeParameterSubstitutionChecker()
+                ReifiedTypeParameterSubstitutionChecker(),
+                InlinePlatformCompatibilityChecker()
         ),
 
         additionalTypeCheckers = listOf(

compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/library/a.kt

@@ -0,0 +1,39 @@
+// JVM_TARGET: 1.8
+package a
+
+inline fun inlineFun(p: () -> Unit) {
+    p()
+}
+
+var inlineGetter: Int
+    inline get() = 1
+    set(varue) {}
+
+var inlineSetter: Int
+    get() = 1
+    inline set(varue) {}
+
+var allInline: Int
+    inline get() = 1
+    inline set(varue) {}
+
+
+
+class A {
+    inline fun inlineFun(p: () -> Unit) {
+        p()
+    }
+
+    var inlineGetter: Int
+        inline get() = 1
+        set(varue) {}
+
+    var inlineSetter: Int
+        get() = 1
+        inline set(varue) {}
+
+    var allInline: Int
+        inline get() = 1
+        inline set(varue) {}
+
+}

compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/output.txt

@@ -0,0 +1,37 @@
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:6:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    inlineFun {}
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:7:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    inlineGetter
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:8:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    inlineGetter = 1
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:11:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    inlineSetter = 1
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:13:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    allInline
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:14:5: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    allInline = 1
+    ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:17:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.inlineFun {}
+      ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:18:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.inlineGetter
+      ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:19:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.inlineGetter = 1
+      ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:22:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.inlineSetter = 1
+      ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:24:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.allInline
+      ^
+compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt:25:7: error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6. Please specify proper '-jvm-target' option
+    a.allInline = 1
+      ^
+COMPILATION_ERROR

compiler/testData/compileKotlinAgainstCustomBinaries/wrongInlineTarget/source.kt

@@ -0,0 +1,28 @@
+package usage
+
+import a.*
+
+fun baz() {
+    inlineFun {}
+    inlineGetter
+    inlineGetter = 1
+
+    inlineSetter
+    inlineSetter = 1
+
+    allInline
+    allInline = 1
+
+    val a = A()
+    a.inlineFun {}
+    a.inlineGetter
+    a.inlineGetter = 1
+
+    a.inlineSetter
+    a.inlineSetter = 1
+
+    a.allInline
+    a.allInline = 1
+}
+
+

compiler/tests-java8/tests/org/jetbrains/kotlin/jvm/repl/ReplCompilerJava8Test.kt

@@ -83,13 +83,10 @@ class ReplCompilerJava8Test : TestCase() {
         val configuration = makeConfiguration().apply {
             put(JVMConfigurationKeys.JVM_TARGET, JvmTarget.JVM_1_6)
         }
-        try {
-            runTest(configuration)
-            Assert.fail("Should fail due to bytecode incompatibility check")
-        }
-        catch (e: CompilationException) {
-            Assert.assertTrue(e.message!!.contains("This compiler can only inline Java 1.6 bytecode (version 50)"))
-        }
+
+        val result = runTest(configuration)
+        Assert.assertTrue(result is ReplCompileResult.Error)
+        Assert.assertTrue((result as ReplCompileResult.Error).message.contains("error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6"))
     }
 
     @Test
@@ -98,11 +95,9 @@ class ReplCompilerJava8Test : TestCase() {
         val configuration = makeConfiguration()
         System.setProperty(KOTLIN_REPL_JVM_TARGET_PROPERTY, "1.6")
         try {
-            runTest(configuration)
-            Assert.fail("Should fail due to bytecode incompatibility check")
-        }
-        catch (e: CompilationException) {
-            Assert.assertTrue(e.message!!.contains("This compiler can only inline Java 1.6 bytecode (version 50)"))
+            val result = runTest(configuration)
+            Assert.assertTrue(result is ReplCompileResult.Error)
+            Assert.assertTrue((result as ReplCompileResult.Error).message.contains("error: cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6"))
         }
         finally {
             System.clearProperty(KOTLIN_REPL_JVM_TARGET_PROPERTY)

compiler/tests/org/jetbrains/kotlin/jvm/compiler/CompileKotlinAgainstCustomBinariesTest.java

@@ -89,15 +89,19 @@ public class CompileKotlinAgainstCustomBinariesTest extends TestCaseWithTmpdir {
 
     @NotNull
     private File compileLibrary(@NotNull String sourcePath, @NotNull File... extraClassPath) {
+        return compileLibrary(sourcePath, Collections.<String>emptyList(), extraClassPath);
+    }
+
+    private File compileLibrary(@NotNull String sourcePath, List<String> additionalOptions, @NotNull File... extraClassPath) {
         File destination = new File(tmpdir, sourcePath + ".jar");
-        compileLibrary(new K2JVMCompiler(), sourcePath, destination, extraClassPath);
+        compileLibrary(new K2JVMCompiler(), sourcePath, destination, additionalOptions, extraClassPath);
         return destination;
     }
 
     private void compileLibrary(
-            @NotNull CLICompiler<?> compiler, @NotNull String sourcePath, @NotNull File destination, @NotNull File... extraClassPath
+            @NotNull CLICompiler<?> compiler, @NotNull String sourcePath, @NotNull File destination, List<String> additionalOptions, @NotNull File... extraClassPath
     ) {
-        Pair<String, ExitCode> output = compileKotlin(compiler, sourcePath, destination, Collections.<String>emptyList(), extraClassPath);
+        Pair<String, ExitCode> output = compileKotlin(compiler, sourcePath, destination, additionalOptions, extraClassPath);
         Assert.assertEquals(normalizeOutput(new Pair<String, ExitCode>("", ExitCode.OK)), normalizeOutput(output));
     }
 
@@ -324,7 +328,7 @@ public class CompileKotlinAgainstCustomBinariesTest extends TestCaseWithTmpdir {
 
         try {
             System.setProperty(TEST_IS_PRE_RELEASE_SYSTEM_PROPERTY, "true");
-            compileLibrary(compiler, libraryName, destination);
+            compileLibrary(compiler, libraryName, destination, Collections.<String>emptyList());
         }
         finally {
             System.clearProperty(TEST_IS_PRE_RELEASE_SYSTEM_PROPERTY);
@@ -629,4 +633,14 @@ public class CompileKotlinAgainstCustomBinariesTest extends TestCaseWithTmpdir {
         Pair<String, ExitCode> output = compileKotlin("source.kt", tmpdir, library1);
         KotlinTestUtils.assertEqualsToFile(new File(getTestDataDirectory(), "output.txt"), normalizeOutput(output));
     }
+
+    public void testWrongInlineTarget() throws Exception {
+        File library = compileLibrary("library", Arrays.asList("-jvm-target", "1.8"));
+
+        Pair<String, ExitCode> outputMain = compileKotlin("source.kt", tmpdir, library);
+
+        KotlinTestUtils.assertEqualsToFile(
+                new File(getTestDataDirectory(), "output.txt"), normalizeOutput(outputMain)
+        );
+    }
 }

compiler/util/src/org/jetbrains/kotlin/config/JvmTarget.kt

@@ -17,17 +17,36 @@
 package org.jetbrains.kotlin.config
 
 import org.jetbrains.kotlin.utils.DescriptionAware
+import org.jetbrains.org.objectweb.asm.Opcodes
 
 enum class JvmTarget(override val description: String) : DescriptionAware {
     JVM_1_6("1.6"),
     JVM_1_8("1.8"),
     ;
 
+    val bytecodeVersion: Int
+        get() = when(this) {
+            JVM_1_6 -> Opcodes.V1_6
+            JVM_1_8 -> Opcodes.V1_8
+        }
+
     companion object {
         @JvmField
         val DEFAULT = JVM_1_6
 
         @JvmStatic
         fun fromString(string: String) = values().find { it.description == string }
+
+        fun getDescription(bytecodeVersion: Int): String {
+            val platformDescription = values().find { it.bytecodeVersion == bytecodeVersion }?.description ?:
+                   when (bytecodeVersion) {
+                       Opcodes.V1_7 -> "1.7"
+                       Opcodes.V1_8 + 1 -> "1.9"
+                       else -> null
+                   }
+
+            return if (platformDescription != null) "JVM target $platformDescription"
+                    else "JVM bytecode version $bytecodeVersion"
+        }
     }
 }