Reorganize access to "customized" features in LanguageVersionSettings

Right now, there is no guaranteed way to get the full set of language
features that have been customized in `LanguageVersionSettings`.
I.e., which features were explicitly specified in the LANGUAGE
directive of a test data file with "plus" and "minus" signs
irrespectively of their state for the specific language version used
in that test.

There are two auxiliary functions that might look like they do exactly
what is required. But in fact they are not:
`getManuallyEnabledLanguageFeatures()` and
`getManuallyDisabledLanguageFeatures()`. These functions return ONLY
meaningful language features. And they filter out any enabled feature
that is already "stable" in the current language version, or any
disabled language feature that is "experimental" in the current LV.

So, we are introducing a new function in `LanguageVersionSettings`
to get the full set of customized features:
`getCustomizedLanguageFeatures()`. Also, the two auxiliary functions
are renamed to `getCustomizedEffectively[En|Dis]abledLanguageFeatures()`
to correctly reflect their meaning.

^KT-71957
^KT-78188

Author: ddolovov

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/serializeModuleIntoKlib.kt

@@ -17,6 +17,8 @@ import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.config.forcesPreReleaseBinariesIfEnabled
+import org.jetbrains.kotlin.config.getCustomizedEffectivelyDisabledLanguageFeatures
+import org.jetbrains.kotlin.config.getCustomizedEffectivelyEnabledLanguageFeatures
 import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.impl.deduplicating
@@ -202,11 +204,12 @@ fun <Dependency : KotlinLibrary, SourceFile> serializeModuleIntoKlib(
 }
 
 fun addLanguageFeaturesToManifest(manifestProperties: Properties, languageVersionSettings: LanguageVersionSettings) {
-    val enabledFeatures = languageVersionSettings.getManuallyEnabledLanguageFeatures()
-
+    val enabledFeatures = languageVersionSettings.getCustomizedEffectivelyEnabledLanguageFeatures()
     val presentableEnabledFeatures = enabledFeatures.sortedBy(LanguageFeature::name).joinToString(" ") { "+$it" }
-    val presentableDisabledFeatures =
-        languageVersionSettings.getManuallyDisabledLanguageFeatures().sortedBy(LanguageFeature::name).joinToString(" ") { "-$it" }
+
+    val disabledFeatures = languageVersionSettings.getCustomizedEffectivelyDisabledLanguageFeatures()
+    val presentableDisabledFeatures = disabledFeatures.sortedBy(LanguageFeature::name).joinToString(" ") { "-$it" }
+
     val presentableAlteredFeatures = "$presentableEnabledFeatures $presentableDisabledFeatures".trim()
     if (presentableAlteredFeatures.isNotBlank()) {
         manifestProperties.setProperty(KLIB_PROPERTY_MANUALLY_ALTERED_LANGUAGE_FEATURES, presentableAlteredFeatures)

compiler/tests-common-new/testFixtures/org/jetbrains/kotlin/test/frontend/classic/handlers/ClassicUnstableAndK2LanguageFeaturesSkipConfigurator.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.test.frontend.classic.handlers
 
 import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.config.getCustomizedEffectivelyEnabledLanguageFeatures
 import org.jetbrains.kotlin.test.services.MetaTestConfigurator
 import org.jetbrains.kotlin.test.services.TestServices
 import org.jetbrains.kotlin.test.services.moduleStructure
@@ -25,7 +26,7 @@ class ClassicUnstableAndK2LanguageFeaturesSkipConfigurator(testServices: TestSer
     override fun shouldSkipTest(): Boolean {
         val settings = testServices.moduleStructure.modules.first().languageVersionSettings
         if (settings.languageVersion.usesK2) return false
-        return settings.getManuallyEnabledLanguageFeatures().any { feature ->
+        return settings.getCustomizedEffectivelyEnabledLanguageFeatures().any { feature ->
             when (val sinceVersion = feature.sinceVersion) {
                 null -> feature in unscheduledK2OnlyFeatures
                 else -> sinceVersion.usesK2

compiler/tests-common/testFixtures/org/jetbrains/kotlin/checkers/CompilerTestLanguageVersionSettings.kt

@@ -36,11 +36,8 @@ data class CompilerTestLanguageVersionSettings(
     override fun getFeatureSupport(feature: LanguageFeature): LanguageFeature.State =
         extraLanguageFeatures[feature] ?: delegate.getFeatureSupport(feature)
 
-    override fun getManuallyEnabledLanguageFeatures(): List<LanguageFeature> =
-        delegate.getManuallyEnabledLanguageFeatures()
-
-    override fun getManuallyDisabledLanguageFeatures(): List<LanguageFeature> =
-        delegate.getManuallyDisabledLanguageFeatures()
+    override fun getCustomizedLanguageFeatures(): Map<LanguageFeature, LanguageFeature.State> =
+        delegate.getCustomizedLanguageFeatures()
 
     override fun isPreRelease(): Boolean = KotlinCompilerVersion.isPreRelease()
 

compiler/tests-compiler-utils/testFixtures/org/jetbrains/kotlin/fir/session/FirSessionFactoryHelper.kt

@@ -104,9 +104,7 @@ object FirSessionFactoryHelper {
                         return features.getOrDefault(feature, LanguageFeature.State.DISABLED)
                     }
 
-                    override fun getManuallyEnabledLanguageFeatures(): List<LanguageFeature> = stub()
-
-                    override fun getManuallyDisabledLanguageFeatures(): List<LanguageFeature> = stub()
+                    override fun getCustomizedLanguageFeatures(): Map<LanguageFeature, LanguageFeature.State> = stub()
 
                     override fun isPreRelease(): Boolean = stub()
 

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

@@ -695,9 +695,7 @@ interface LanguageVersionSettings {
     fun supportsFeature(feature: LanguageFeature): Boolean =
         getFeatureSupport(feature) == LanguageFeature.State.ENABLED
 
-    fun getManuallyEnabledLanguageFeatures(): List<LanguageFeature>
-
-    fun getManuallyDisabledLanguageFeatures(): List<LanguageFeature>
+    fun getCustomizedLanguageFeatures(): Map<LanguageFeature, LanguageFeature.State>
 
     fun isPreRelease(): Boolean
 
@@ -735,20 +733,7 @@ class LanguageVersionSettingsImpl @JvmOverloads constructor(
         }
     }
 
-    override fun getManuallyEnabledLanguageFeatures(): List<LanguageFeature> =
-        specificFeatures.filter { isEnabledOnlyByFlag(it.key, it.value) }.keys.toList()
-
-    override fun getManuallyDisabledLanguageFeatures(): List<LanguageFeature> =
-        specificFeatures.filter { isDisabledOnlyByFlag(it.key, it.value) }.keys.toList()
-
-    private fun isEnabledOnlyByFlag(feature: LanguageFeature, state: LanguageFeature.State): Boolean =
-        !isEnabledByDefault(feature) && (state == LanguageFeature.State.ENABLED)
-
-    private fun isDisabledOnlyByFlag(feature: LanguageFeature, state: LanguageFeature.State): Boolean =
-        isEnabledByDefault(feature) && state == LanguageFeature.State.DISABLED
-
-    private fun isEnabledByDefault(feature: LanguageFeature): Boolean =
-        feature.sinceVersion != null && languageVersion >= feature.sinceVersion && apiVersion >= feature.sinceApiVersion
+    override fun getCustomizedLanguageFeatures(): Map<LanguageFeature, LanguageFeature.State> = specificFeatures
 
     override fun toString() = buildString {
         append("Language = $languageVersion, API = $apiVersion")
@@ -785,3 +770,18 @@ fun LanguageFeature.forcesPreReleaseBinariesIfEnabled(): Boolean {
     val isFeatureNotReleasedYet = sinceVersion?.isStable != true
     return isFeatureNotReleasedYet && forcesPreReleaseBinaries
 }
+
+fun LanguageVersionSettings.getCustomizedEffectivelyEnabledLanguageFeatures(): Set<LanguageFeature> {
+    return getCustomizedLanguageFeatures().entries.mapNotNullTo(mutableSetOf()) { (feature, state) ->
+        feature.takeIf { !isEnabledByDefault(feature) && state == LanguageFeature.State.ENABLED }
+    }
+}
+
+fun LanguageVersionSettings.getCustomizedEffectivelyDisabledLanguageFeatures(): Set<LanguageFeature> {
+    return getCustomizedLanguageFeatures().entries.mapNotNullTo(mutableSetOf()) { (feature, state) ->
+        feature.takeIf { isEnabledByDefault(feature) && state == LanguageFeature.State.DISABLED }
+    }
+}
+
+private fun LanguageVersionSettings.isEnabledByDefault(languageFeature: LanguageFeature): Boolean =
+    languageFeature.sinceVersion != null && languageVersion >= languageFeature.sinceVersion && apiVersion >= languageFeature.sinceApiVersion