Language version 2.0: fix compiler messages and minor details

compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/K2JSCompiler.java

@@ -175,15 +175,15 @@ public class K2JSCompiler extends CLICompiler<K2JSCompilerArguments> {
 
         ExitCode exitCode = OK;
 
-        LanguageVersionSettings languageVersionSettings = CommonConfigurationKeysKt.getLanguageVersionSettings(configuration);
-        LanguageVersion languageVersion = languageVersionSettings.getLanguageVersion();
-        if (K2JSCompilerArgumentsKt.isIrBackendEnabled(arguments) || languageVersion.getUsesK2()) {
+        boolean useFir = Boolean.TRUE.equals(configuration.get(CommonConfigurationKeys.USE_FIR));
+        if (K2JSCompilerArgumentsKt.isIrBackendEnabled(arguments) || useFir) {
             exitCode = getIrCompiler().doExecute(arguments, configuration.copy(), rootDisposable, paths);
         }
-        if (K2JSCompilerArgumentsKt.isPreIrBackendDisabled(arguments) || languageVersion.getUsesK2()) {
+        if (K2JSCompilerArgumentsKt.isPreIrBackendDisabled(arguments) || useFir) {
             return exitCode;
         }
 
+        LanguageVersionSettings languageVersionSettings = CommonConfigurationKeysKt.getLanguageVersionSettings(configuration);
 
         if (CompilerSystemProperties.KOTLIN_JS_COMPILER_LEGACY_FORCE_ENABLED.getValue() != "true" && languageVersionSettings.getLanguageVersion().compareTo(LanguageVersion.KOTLIN_1_9) >= 0) {
             messageCollector.report(ERROR, "Old Kotlin/JS compiler is no longer supported. Please migrate to the new JS IR backend", null);

compiler/cli/src/org/jetbrains/kotlin/cli/common/CLICompiler.kt

@@ -104,19 +104,19 @@ abstract class CLICompiler<A : CommonCompilerArguments> : CLITool<A>() {
                         arguments.languageVersion == null -> {
                             messageCollector.report(
                                 STRONG_WARNING,
-                                "Compiler flag -Xuse-k2 is deprecated, please use -language-version 2.0 instead"
+                                "Compiler flag -Xuse-k2 is deprecated, please use \"-language-version 2.0\" instead"
                             )
                         }
                         languageVersion.usesK2 -> {
                             messageCollector.report(
                                 STRONG_WARNING,
-                                "Compiler flag -Xuse-k2 is redundant"
+                                "Compiler flag -Xuse-k2 is redundant, the \"-language-version 2.0\" is used instead"
                             )
                         }
                         else -> {
                             messageCollector.report(
                                 STRONG_WARNING,
-                                "With -Xuse-k2 compiler flag -language-version $languageVersion has no effect, please remove -Xuse-k2 flag or use -language-version 2.0 instead"
+                                "With -Xuse-k2 compiler flag \"-language-version $languageVersion\" has no effect, please remove -Xuse-k2 flag and use \"-language-version 2.0\" instead"
                             )
                         }
                     }
@@ -202,7 +202,8 @@ abstract class CLICompiler<A : CommonCompilerArguments> : CLITool<A>() {
         val pluginConfigurations = arguments.pluginConfigurations.orEmpty().toMutableList()
         val messageCollector = configuration.getNotNull(MESSAGE_COLLECTOR_KEY)
 
-        if (!checkPluginsArguments(messageCollector, arguments.useK2, pluginClasspaths, pluginOptions, pluginConfigurations)) {
+        val useK2 = configuration.get(CommonConfigurationKeys.USE_FIR) == true
+        if (!checkPluginsArguments(messageCollector, useK2, pluginClasspaths, pluginOptions, pluginConfigurations)) {
             return INTERNAL_ERROR
         }
 
@@ -274,7 +275,7 @@ fun checkPluginsArguments(
             hasErrors = true
             messageCollector.report(
                 ERROR,
-                "-Xcompiler-plugin argument is allowed only for for K2 compiler. Please use -Xplugin argument or enable -Xuse-k2"
+                "-Xcompiler-plugin argument is allowed only for language version 2.0. Please use -Xplugin argument for language version 1.9 and below"
             )
         }
         if (pluginClasspaths.isNotEmpty() || pluginOptions.isNotEmpty()) {

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/FirKotlinToJvmBytecodeCompiler.kt

@@ -86,7 +86,7 @@ object FirKotlinToJvmBytecodeCompiler {
                 """
                     |There are some plugins incompatible with language version 2.0:
                     |${notSupportedPlugins.joinToString(separator = "\n|") { "  $it" }}
-                    |Please use language version 1.* (e.g. 1.9)
+                    |Please use language version 1.9 or below
                 """.trimMargin()
             )
             return false

compiler/cli/src/org/jetbrains/kotlin/cli/metadata/K2MetadataCompiler.kt

@@ -59,7 +59,7 @@ class K2MetadataCompiler : CLICompiler<K2MetadataCompilerArguments>() {
     ): ExitCode {
         val collector = configuration.getNotNull(CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY)
         if (configuration.getBoolean(CommonConfigurationKeys.USE_FIR)) {
-            collector.report(ERROR, "Compilation to metadata is not supported in language version 2.0 right now")
+            collector.report(ERROR, "Compilation to metadata is not supported with language version 2.0 right now")
             return ExitCode.COMPILATION_ERROR
         }
         val performanceManager = configuration.getNotNull(CLIConfigurationKeys.PERF_MANAGER)

compiler/testData/cli/jvm/firHello.out

@@ -1,3 +1,3 @@
-warning: compiler flag -Xuse-k2 is deprecated, please use -language-version 2.0 instead
+warning: compiler flag -Xuse-k2 is deprecated, please use "-language-version 2.0" instead
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
 OK

compiler/testData/cli/jvm/firHello20WithFlag.out

@@ -1,3 +1,3 @@
-warning: compiler flag -Xuse-k2 is redundant
+warning: compiler flag -Xuse-k2 is redundant, the "-language-version 2.0" is used instead
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
 OK

compiler/testData/cli/jvm/firHello20WithOldLV.out

@@ -1,3 +1,3 @@
-warning: with -Xuse-k2 compiler flag -language-version 1.5 has no effect, please remove -Xuse-k2 flag or use -language-version 2.0 instead
+warning: with -Xuse-k2 compiler flag "-language-version 1.5" has no effect, please remove -Xuse-k2 flag and use "-language-version 2.0" instead
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
 OK

compiler/testData/cli/metadata/fir.out

@@ -1,3 +1,3 @@
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-error: compilation to metadata is not supported in language version 2.0 right now
+error: compilation to metadata is not supported with language version 2.0 right now
 COMPILATION_ERROR

compiler/testData/compileKotlinAgainstCustomBinaries/firAgainstFirUsingFlag/output.txt

@@ -1,2 +1,2 @@
-warning: compiler flag -Xuse-k2 is deprecated, please use -language-version 2.0 instead
+warning: compiler flag -Xuse-k2 is deprecated, please use "-language-version 2.0" instead
 OK

kotlin-native/backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2Native.kt

@@ -58,9 +58,6 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
         if (pluginLoadResult != ExitCode.OK) return pluginLoadResult
 
         val messageCollector = configuration.get(CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY) ?: MessageCollector.NONE
-        if (configuration.getBoolean(CommonConfigurationKeys.USE_FIR)) {
-            messageCollector.report(WARNING, "New compiler pipeline K2 is experimental in Kotlin/Native. No compatibility guarantees are yet provided")
-        }
 
         val enoughArguments = arguments.freeArgs.isNotEmpty() || arguments.isUsefulWithoutFreeArgs
         if (!enoughArguments) {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/sources/DefaultLanguageSettingsBuilder.kt

@@ -146,7 +146,7 @@ private val apiVersionValues = ApiVersion.run {
         KOTLIN_1_7,
         KOTLIN_1_8,
         KOTLIN_1_9,
-        KOTLIN_2_0
+        KOTLIN_2_0,
     )
 }
 

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/Kapt3Plugin.kt

@@ -71,7 +71,7 @@ class Kapt3CommandLineProcessor : CommandLineProcessor {
         if (configuration.getBoolean(CommonConfigurationKeys.USE_FIR)) {
             configuration[CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY]?.report(
                 CompilerMessageSeverity.ERROR,
-                "kapt currently doesn't support language version 2.0\nPlease use language version 1.* (e.g. 1.9) instead"
+                "kapt currently doesn't support language version 2.0\nPlease use language version 1.9 or below"
             )
         }