KT-52217 Rename 'use-fir' to 'use-k2', update message

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/CommonCompilerArguments.kt

@@ -294,10 +294,11 @@ abstract class CommonCompilerArguments : CommonToolArguments() {
 
     @GradleOption(DefaultValues.BooleanFalseDefault::class)
     @Argument(
-        value = "-Xuse-fir",
+        value = "-Xuse-k2",
-        description = "Compile using Front-end IR. Warning: this feature is far from being production-ready"
+        deprecatedName = "-Xuse-fir",
+        description = "Compile using experimental K2. K2 is a new compiler pipeline, no compatibility guarantees are yet provided"
     )
-    var useFir: Boolean by FreezableVar(false)
+    var useK2: Boolean by FreezableVar(false)
 
     @Argument(
         value = "-Xuse-fir-extended-checkers",

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JVMCompilerArguments.kt

@@ -528,7 +528,7 @@ Also sets `-jvm-target` value equal to the selected JDK version"""
         result[JvmAnalysisFlags.sanitizeParentheses] = sanitizeParentheses
         result[JvmAnalysisFlags.suppressMissingBuiltinsError] = suppressMissingBuiltinsError
         result[JvmAnalysisFlags.enableJvmPreview] = enableJvmPreview
-        result[AnalysisFlags.allowUnstableDependencies] = allowUnstableDependencies || useFir
+        result[AnalysisFlags.allowUnstableDependencies] = allowUnstableDependencies || useK2
         result[JvmAnalysisFlags.disableUltraLightClasses] = disableUltraLightClasses
         result[JvmAnalysisFlags.useIR] = !useOldBackend
         return result

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

@@ -22,7 +22,7 @@ fun <A : CommonCompilerArguments> CompilerConfiguration.setupCommonArguments(
     createMetadataVersion: ((IntArray) -> BinaryVersion)? = null
 ) {
     put(CommonConfigurationKeys.DISABLE_INLINE, arguments.noInline)
-    put(CommonConfigurationKeys.USE_FIR, arguments.useFir)
+    put(CommonConfigurationKeys.USE_FIR, arguments.useK2)
     put(CommonConfigurationKeys.USE_FIR_EXTENDED_CHECKERS, arguments.useFirExtendedCheckers)
     put(CommonConfigurationKeys.EXPECT_ACTUAL_LINKER, arguments.expectActualLinker)
     putIfNotNull(CLIConfigurationKeys.INTELLIJ_PLUGIN_ROOT, arguments.intellijPluginRoot)

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

@@ -82,7 +82,7 @@ object FirKotlinToJvmBytecodeCompiler {
 
         messageCollector.report(
             STRONG_WARNING,
-            "ATTENTION!\n This build uses in-dev FIR: \n  -Xuse-fir"
+            "ATTENTION!\n This build uses experimental K2 compiler: \n  -Xuse-k2"
         )
 
         projectConfiguration.get(ComponentRegistrar.PLUGIN_COMPONENT_REGISTRARS)?.let { pluginComponentRegistrars ->

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt

@@ -97,7 +97,7 @@ fun compileModulesUsingFrontendIrAndLightTree(
 
     messageCollector.report(
         CompilerMessageSeverity.STRONG_WARNING,
-        "ATTENTION!\n This build uses in-dev FIR: \n  -Xuse-fir"
+        "ATTENTION!\n This build uses experimental K2 compiler: \n  -Xuse-k2"
     )
 
     val outputs = mutableListOf<GenerationState>()

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

@@ -230,7 +230,7 @@ fun CompilerConfiguration.configureAdvancedJvmOptions(arguments: K2JVMCompilerAr
 
     // TODO: ignore previous configuration value when we do not need old backend in scripting by default
     val useOldBackend = arguments.useOldBackend || (!arguments.useIR && get(JVMConfigurationKeys.IR) == false)
-    val useIR = arguments.useFir ||
+    val useIR = arguments.useK2 ||
             if (languageVersionSettings.supportsFeature(LanguageFeature.JvmIrEnabledByDefault)) {
                 !useOldBackend
             } else {

compiler/fir/modularized-tests/tests/org/jetbrains/kotlin/fir/FE1FullPipelineModularizedTest.kt

@@ -15,7 +15,7 @@ class FE1FullPipelineModularizedTest : AbstractFullPipelineModularizedTest() {
     override fun configureArguments(args: K2JVMCompilerArguments, moduleData: ModuleData) {
         args.useIR = USE_BE_IR
         args.useOldBackend = !USE_BE_IR
-        args.useFir = false
+        args.useK2 = false
         args.jvmDefault = "compatibility"
         args.apiVersion = "1.4"
         args.optIn = arrayOf(

compiler/fir/modularized-tests/tests/org/jetbrains/kotlin/fir/FullPipelineModularizedTest.kt

@@ -12,7 +12,7 @@ private val LANGUAGE_VERSION: String = System.getProperty("fir.bench.language.ve
 class FullPipelineModularizedTest : AbstractFullPipelineModularizedTest() {
 
     override fun configureArguments(args: K2JVMCompilerArguments, moduleData: ModuleData) {
-        args.useFir = true
+        args.useK2 = true
         args.useIR = true
         args.apiVersion = LANGUAGE_VERSION
         args.jvmDefault = "compatibility"

compiler/incremental-compilation-impl/src/org/jetbrains/kotlin/incremental/IncrementalJvmCompilerRunner.kt

@@ -88,7 +88,7 @@ fun makeIncrementally(
 
     withIC(args) {
         val compiler =
-            if (args.useFir && args.useFirIC && args.useFirLT /* TODO: move LT check into runner */ )
+            if (args.useK2 && args.useFirIC && args.useFirLT /* TODO: move LT check into runner */ )
                 IncrementalFirJvmCompilerRunner(
                     cachesDir, buildReporter, buildHistoryFile, emptyList(), EmptyModulesApiHistory, kotlinExtensions, ClasspathSnapshotDisabled
                 )
@@ -97,7 +97,7 @@ fun makeIncrementally(
                     cachesDir,
                     buildReporter,
                     // Use precise setting in case of non-Gradle build
-                    usePreciseJavaTracking = !args.useFir, // TODO: add fir-based java classes tracker when available and set this to true
+                    usePreciseJavaTracking = !args.useK2, // TODO: add fir-based java classes tracker when available and set this to true
                     outputFiles = emptyList(),
                     buildHistoryFile = buildHistoryFile,
                     modulesApiHistory = EmptyModulesApiHistory,

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalFirICLightTreeJvmCompilerRunnerTest.kt

@@ -12,7 +12,7 @@ import java.io.File
 abstract class AbstractIncrementalFirICLightTreeJvmCompilerRunnerTest : AbstractIncrementalJvmCompilerRunnerTest() {
     override fun createCompilerArguments(destinationDir: File, testDir: File): K2JVMCompilerArguments =
         super.createCompilerArguments(destinationDir, testDir).apply {
-            useFir = true
+            useK2 = true
             useIR = true
             useFirIC = true
             useFirLT = true

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalFirJvmCompilerRunnerTest.kt

@@ -23,7 +23,7 @@ import java.io.File
 abstract class AbstractIncrementalFirJvmCompilerRunnerTest : AbstractIncrementalJvmCompilerRunnerTest() {
     override fun createCompilerArguments(destinationDir: File, testDir: File): K2JVMCompilerArguments =
         super.createCompilerArguments(destinationDir, testDir).apply {
-            useFir = true
+            useK2 = true
             useIR = true
         }
 

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalFirLightTreeJvmCompilerRunnerTest.kt

@@ -12,7 +12,7 @@ import java.io.File
 abstract class AbstractIncrementalFirLightTreeJvmCompilerRunnerTest : AbstractIncrementalJvmCompilerRunnerTest() {
     override fun createCompilerArguments(destinationDir: File, testDir: File): K2JVMCompilerArguments =
         super.createCompilerArguments(destinationDir, testDir).apply {
-            useFir = true
+            useK2 = true
             useIR = true
             useFirIC = false
             useFirLT = true

compiler/testData/cli/js/jsExtraHelp.out

@@ -104,10 +104,10 @@ where advanced options include:
   -Xsuppress-version-warnings Suppress warnings about outdated, inconsistent or experimental language or API versions
   -Xunrestricted-builder-inference
                              Eliminate builder inference restrictions like allowance of returning type variables of a builder inference call
-  -Xuse-fir                  Compile using Front-end IR. Warning: this feature is far from being production-ready
   -Xuse-fir-extended-checkers Use extended analysis mode based on Front-end IR. Warning: this feature is far from being production-ready
   -Xuse-fir-ic               Compile using Front-end IR internal incremental compilation cycle. Warning: this feature is far from being production-ready
   -Xuse-fir-lt               Compile using LightTree parser with Front-end IR. Warning: this feature is far from being production-ready
+  -Xuse-k2                   Compile using experimental K2. K2 is a new compiler pipeline, no compatibility guarantees are yet provided
   -Xuse-mixed-named-arguments Enable Support named arguments in their own position even if the result appears as mixed
   -Xverbose-phases           Be verbose while performing these backend phases
 

compiler/testData/cli/jvm/conflictingProjection.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/conflictingProjection.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/conflictingProjection.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/conflictingProjection.kt:10:19: error: projection is conflicting with variance of the corresponding type parameter of Out<in kotlin/Int>. Remove the projection or replace it with '*'
 fun a8(value: Out<in Int>) {}
                   ^

compiler/testData/cli/jvm/extendedCheckers.args

@@ -1,5 +1,5 @@
 $TESTDATA_DIR$/extendedCheckers.kt
--Xuse-fir
+-Xuse-k2
 -Xuse-fir-extended-checkers
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/extendedCheckers.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/extendedCheckers.kt:2:12: warning: redundant explicit type
     val i: Int = 1
            ^

compiler/testData/cli/jvm/extendedCheckersNoWarning.args

@@ -1,5 +1,5 @@
 $TESTDATA_DIR$/extendedCheckersNoWarning.kt
--Xuse-fir
+-Xuse-k2
 -Xuse-fir-extended-checkers
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/extendedCheckersNoWarning.out

@@ -1,4 +1,4 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 OK

compiler/testData/cli/jvm/extraHelp.out

@@ -210,10 +210,10 @@ where advanced options include:
   -Xsuppress-version-warnings Suppress warnings about outdated, inconsistent or experimental language or API versions
   -Xunrestricted-builder-inference
                              Eliminate builder inference restrictions like allowance of returning type variables of a builder inference call
-  -Xuse-fir                  Compile using Front-end IR. Warning: this feature is far from being production-ready
   -Xuse-fir-extended-checkers Use extended analysis mode based on Front-end IR. Warning: this feature is far from being production-ready
   -Xuse-fir-ic               Compile using Front-end IR internal incremental compilation cycle. Warning: this feature is far from being production-ready
   -Xuse-fir-lt               Compile using LightTree parser with Front-end IR. Warning: this feature is far from being production-ready
+  -Xuse-k2                   Compile using experimental K2. K2 is a new compiler pipeline, no compatibility guarantees are yet provided
   -Xuse-mixed-named-arguments Enable Support named arguments in their own position even if the result appears as mixed
   -Xverbose-phases           Be verbose while performing these backend phases
 

compiler/testData/cli/jvm/firError.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/firError.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/firError.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/firError.kt:5:13: error: variable 'x' must be initialized
     println(x)
             ^

compiler/testData/cli/jvm/firHello.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/firHello.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/firHello.out

@@ -1,4 +1,4 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 OK

compiler/testData/cli/jvm/firMultiplatformCompilationWithError.args

@@ -2,7 +2,7 @@ $TESTDATA_DIR$/firMultiplatformCompilationWithError/common.kt
 $TESTDATA_DIR$/firMultiplatformCompilationWithError/jvm.kt
 -Xcommon-sources
 $TESTDATA_DIR$/firMultiplatformCompilationWithError/common.kt
--Xuse-fir
+-Xuse-k2
 -cp
 .
 -d

compiler/testData/cli/jvm/firMultiplatformCompilationWithError.out

@@ -9,8 +9,8 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/firMultiplatformCompilationWithError/jvm.kt:1:18: error: actual class 'public abstract actual interface A : R|kotlin/Any|' has no corresponding members for expected class members:
 
     public abstract expect fun foo(): R|kotlin/Unit|

compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors.args

@@ -2,7 +2,7 @@ $TESTDATA_DIR$/firMultiplatformCompilationWithoutErrors/common.kt
 $TESTDATA_DIR$/firMultiplatformCompilationWithoutErrors/jvm.kt
 -Xcommon-sources
 $TESTDATA_DIR$/firMultiplatformCompilationWithoutErrors/common.kt
--Xuse-fir
+-Xuse-k2
 -cp
 .
 -d

compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors.out

@@ -9,6 +9,6 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 OK

compiler/testData/cli/jvm/firStdlibDependency.args

@@ -1,5 +1,5 @@
 $TESTDATA_DIR$/firStdlibDependency.kt
--Xuse-fir
+-Xuse-k2
 -cp
 .
 -d

compiler/testData/cli/jvm/firStdlibDependency.out

@@ -1,4 +1,4 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 OK

compiler/testData/cli/jvm/firVsClassicAnnotation.args

@@ -1,6 +1,6 @@
 $TESTDATA_DIR$/firVsClassicAnnotation.kt
 -classpath
 $TESTDATA_DIR$/firVsClassicAnnotation
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/firVsClassicAnnotation.out

@@ -1,4 +1,4 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 OK

compiler/testData/cli/jvm/inapplicableLateinitModifier.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/inapplicableLateinitModifier.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/inapplicableLateinitModifier.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/inapplicableLateinitModifier.kt:6:1: error: 'lateinit' modifier is not allowed on delegated properties
 lateinit var kest by Delegate
 ^

compiler/testData/cli/jvm/instanceAccessBeforeSuperCall.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/instanceAccessBeforeSuperCall.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$

compiler/testData/cli/jvm/instanceAccessBeforeSuperCall.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/instanceAccessBeforeSuperCall.kt:2:26: error: unresolved reference: getSomeInt
     constructor(x: Int = getSomeInt(), other: A = this, header: String = keker) {}
                          ^

compiler/testData/cli/jvm/optInEmptyMessageFir.args

@@ -2,5 +2,5 @@ $TESTDATA_DIR$/optInEmptyMessageFir.kt
 -d
 $TEMP_DIR$
 -opt-in=kotlin.RequiresOptIn
--Xuse-fir
+-Xuse-k2
 

compiler/testData/cli/jvm/optInEmptyMessageFir.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/optInEmptyMessageFir.kt:8:5: error: this declaration needs opt-in. Its usage must be marked with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
     foo()
     ^

compiler/testData/cli/jvm/optInOverrideMessageFir.args

@@ -2,4 +2,4 @@ $TESTDATA_DIR$/optInOverrideMessageFir.kt
 -d
 $TEMP_DIR$
 -opt-in=kotlin.RequiresOptIn
--Xuse-fir
+-Xuse-k2

compiler/testData/cli/jvm/optInOverrideMessageFir.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
+ This build uses experimental K2 compiler:
-  -Xuse-fir
+  -Xuse-k2
 compiler/testData/cli/jvm/optInOverrideMessageFir.kt:16:18: error: base declaration of supertype 'Base' needs opt-in. This API is experimental and can change at any time, please use with care. The declaration override must be annotated with '@Marker' or '@OptIn(Marker::class)'
     override fun foo() {}
                  ^

compiler/tests-common/tests/org/jetbrains/kotlin/jvm/compiler/AbstractKotlinCompilerIntegrationTest.kt

@@ -137,10 +137,7 @@ abstract class AbstractKotlinCompilerIntegrationTest : TestCaseWithTmpdir() {
 
     private fun String.removeFirWarning(): String {
         return this.replace(
-            """warning: ATTENTION!
+            "warning: ATTENTION!\n This build uses experimental K2 compiler: \n  -Xuse-k2\n", ""
- This build uses in-dev FIR: 
-  -Xuse-fir
-""", ""
         )
     }
 

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

@@ -546,7 +546,7 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
 
     fun testInternalFromFriendModuleFir() {
         val library = compileLibrary("library")
-        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xfriend-paths=${library.path}", "-Xuse-fir"))
+        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xfriend-paths=${library.path}", "-Xuse-k2"))
     }
 
     fun testJvmDefaultClashWithOld() {
@@ -620,20 +620,20 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
     }
 
     fun testFirAgainstFir() {
-        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-fir"))
+        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-k2"))
-        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xuse-fir"))
+        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xuse-k2"))
     }
 
     fun testFirAgainstOldJvm() {
         val library = compileLibrary("library")
-        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xuse-fir"))
+        compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xuse-k2"))
     }
 
     fun testFirIncorrectJavaSignature() {
         compileKotlin(
             "source.kt", tmpdir,
             listOf(),
-            additionalOptions = listOf("-Xuse-fir"),
+            additionalOptions = listOf("-Xuse-k2"),
             additionalSources = listOf("A.java", "B.java"),
         )
     }
@@ -647,10 +647,10 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
     }
 
     fun testOldJvmAgainstFir() {
-        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-fir"))
+        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-k2"))
         compileKotlin("source.kt", tmpdir, listOf(library))
 
-        val library2 = compileLibrary("library", additionalOptions = listOf("-Xuse-fir", "-Xabi-stability=unstable"))
+        val library2 = compileLibrary("library", additionalOptions = listOf("-Xuse-k2", "-Xabi-stability=unstable"))
         compileKotlin("source.kt", tmpdir, listOf(library2))
     }
 
@@ -660,12 +660,12 @@ class CompileKotlinAgainstCustomBinariesTest : AbstractKotlinCompilerIntegration
     }
 
     fun testOldJvmAgainstFirWithStableAbi() {
-        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-fir", "-Xabi-stability=stable"))
+        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-k2", "-Xabi-stability=stable"))
         compileKotlin("source.kt", tmpdir, listOf(library))
     }
 
     fun testOldJvmAgainstFirWithAllowUnstableDependencies() {
-        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-fir"))
+        val library = compileLibrary("library", additionalOptions = listOf("-Xuse-k2"))
         compileKotlin("source.kt", tmpdir, listOf(library), additionalOptions = listOf("-Xallow-unstable-dependencies"))
     }
 

jps/jps-common/test/CompilerArgumentsContentProspectorTest.kt

@@ -95,7 +95,7 @@ class CompilerArgumentsContentProspectorTest {
             CommonCompilerArguments::profilePhases,
             CommonCompilerArguments::checkPhaseConditions,
             CommonCompilerArguments::checkStickyPhaseConditions,
-            CommonCompilerArguments::useFir,
+            CommonCompilerArguments::useK2,
             CommonCompilerArguments::useFirExtendedCheckers,
             CommonCompilerArguments::disableUltraLightClasses,
             CommonCompilerArguments::useMixedNamedArguments,

libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinCommonOptions.kt

@@ -20,8 +20,8 @@ interface KotlinCommonOptions  : org.jetbrains.kotlin.gradle.dsl.KotlinCommonToo
      var languageVersion: kotlin.String?
 
     /**
-     * Compile using Front-end IR. Warning: this feature is far from being production-ready
+     * Compile using experimental K2. K2 is a new compiler pipeline, no compatibility guarantees are yet provided
      * Default value: false
      */
-     var useFir: kotlin.Boolean
+     var useK2: kotlin.Boolean
 }

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt

@@ -152,7 +152,7 @@ internal open class GradleCompilerRunner(
                         report(BooleanMetrics.JVM_COMPILER_IR_MODE, args.useIR)
                         report(StringMetrics.JVM_DEFAULTS, args.jvmDefault)
                         report(StringMetrics.USE_OLD_BACKEND, args.useOldBackend.toString())
-                        report(StringMetrics.USE_FIR, args.useFir.toString())
+                        report(StringMetrics.USE_FIR, args.useK2.toString())
                     }
                 }
                 is K2JSCompilerArguments -> {

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinJsOptionsBase.kt

@@ -30,11 +30,11 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
 
     override var languageVersion: kotlin.String? = null
 
-    private var useFirField: kotlin.Boolean? = null
+    private var useK2Field: kotlin.Boolean? = null
-    override var useFir: kotlin.Boolean
+    override var useK2: kotlin.Boolean
-        get() = useFirField ?: false
+        get() = useK2Field ?: false
         set(value) {
-            useFirField = value
+            useK2Field = value
         }
 
     private var friendModulesDisabledField: kotlin.Boolean? = null
@@ -105,7 +105,7 @@ internal abstract class KotlinJsOptionsBase : org.jetbrains.kotlin.gradle.dsl.Ko
         verboseField?.let { args.verbose = it }
         apiVersion?.let { args.apiVersion = it }
         languageVersion?.let { args.languageVersion = it }
-        useFirField?.let { args.useFir = it }
+        useK2Field?.let { args.useK2 = it }
         friendModulesDisabledField?.let { args.friendModulesDisabled = it }
         mainField?.let { args.main = it }
         metaInfoField?.let { args.metaInfo = it }
@@ -126,7 +126,7 @@ internal fun org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments.fil
     verbose = false
     apiVersion = null
     languageVersion = null
-    useFir = false
+    useK2 = false
     friendModulesDisabled = false
     main = "call"
     metaInfo = true

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinJvmOptionsBase.kt

@@ -30,11 +30,11 @@ internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.K
 
     override var languageVersion: kotlin.String? = null
 
-    private var useFirField: kotlin.Boolean? = null
+    private var useK2Field: kotlin.Boolean? = null
-    override var useFir: kotlin.Boolean
+    override var useK2: kotlin.Boolean
-        get() = useFirField ?: false
+        get() = useK2Field ?: false
         set(value) {
-            useFirField = value
+            useK2Field = value
         }
 
     private var javaParametersField: kotlin.Boolean? = null
@@ -68,7 +68,7 @@ internal abstract class KotlinJvmOptionsBase : org.jetbrains.kotlin.gradle.dsl.K
         verboseField?.let { args.verbose = it }
         apiVersion?.let { args.apiVersion = it }
         languageVersion?.let { args.languageVersion = it }
-        useFirField?.let { args.useFir = it }
+        useK2Field?.let { args.useK2 = it }
         javaParametersField?.let { args.javaParameters = it }
         jvmTarget?.let { args.jvmTarget = it }
         moduleName?.let { args.moduleName = it }
@@ -83,7 +83,7 @@ internal fun org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments.fi
     verbose = false
     apiVersion = null
     languageVersion = null
-    useFir = false
+    useK2 = false
     javaParameters = false
     jvmTarget = null
     moduleName = null

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/KotlinMultiplatformCommonOptionsBase.kt

@@ -30,11 +30,11 @@ internal abstract class KotlinMultiplatformCommonOptionsBase : org.jetbrains.kot
 
     override var languageVersion: kotlin.String? = null
 
-    private var useFirField: kotlin.Boolean? = null
+    private var useK2Field: kotlin.Boolean? = null
-    override var useFir: kotlin.Boolean
+    override var useK2: kotlin.Boolean
-        get() = useFirField ?: false
+        get() = useK2Field ?: false
         set(value) {
-            useFirField = value
+            useK2Field = value
         }
 
     internal open fun updateArguments(args: org.jetbrains.kotlin.cli.common.arguments.K2MetadataCompilerArguments) {
@@ -43,7 +43,7 @@ internal abstract class KotlinMultiplatformCommonOptionsBase : org.jetbrains.kot
         verboseField?.let { args.verbose = it }
         apiVersion?.let { args.apiVersion = it }
         languageVersion?.let { args.languageVersion = it }
-        useFirField?.let { args.useFir = it }
+        useK2Field?.let { args.useK2 = it }
     }
 }
 
@@ -53,5 +53,5 @@ internal fun org.jetbrains.kotlin.cli.common.arguments.K2MetadataCompilerArgumen
     verbose = false
     apiVersion = null
     languageVersion = null
-    useFir = false
+    useK2 = false
 }

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

@@ -132,8 +132,8 @@ internal class PropertiesProvider private constructor(private val project: Proje
     val useKotlinAbiSnapshot: Boolean
         get() = booleanProperty(KOTLIN_ABI_SNAPSHOT) ?: false
 
-    val useFir: Boolean?
+    val useK2: Boolean?
-        get() = booleanProperty("kotlin.useFir")
+        get() = booleanProperty("kotlin.useK2")
 
     val keepMppDependenciesIntactInPoms: Boolean?
         get() = booleanProperty("kotlin.mpp.keepMppDependenciesIntactInPoms")

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeCompilation.kt

@@ -36,8 +36,8 @@ internal class NativeCompileOptions(languageSettingsProvider: () -> LanguageSett
         set(value) {
             languageSettings.languageVersion = value
         }
-
+    
-    override var useFir: Boolean
+    override var useK2: Boolean
         get() = false
         set(@Suppress("UNUSED_PARAMETER") value) {}
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/configuration/KotlinCompileConfig.kt

@@ -39,8 +39,8 @@ internal open class BaseKotlinCompileConfig<TASK : KotlinCompile> : AbstractKotl
             taskProvider.configure { task ->
                 task.incremental = propertiesProvider.incrementalJvm ?: true
 
-                if (propertiesProvider.useFir == true) {
+                if (propertiesProvider.useK2 == true) {
-                    task.kotlinOptions.useFir = true
+                    task.kotlinOptions.useK2 = true
                 }
                 task.usePreciseJavaTracking = propertiesProvider.usePreciseJavaTracking ?: true
                 task.jvmTargetValidationMode.set(propertiesProvider.jvmTargetValidationMode)

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/impl/errorReporting.kt

@@ -129,7 +129,7 @@ internal fun reportArgumentsNotAllowed(
         K2JVMCompilerArguments::useJavac,
         K2JVMCompilerArguments::useIR,
         K2JVMCompilerArguments::useOldBackend,
-        K2JVMCompilerArguments::useFir
+        K2JVMCompilerArguments::useK2
     )
 
 internal fun reportArgumentsIgnoredGenerally(