[FIR] Promote diagnostic for -Xcontext-receivers to error

#KT-72994

Author: cypressious

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/config/FirContextParametersLanguageVersionSettingsChecker.kt

@@ -6,36 +6,16 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.config
 
 import org.jetbrains.kotlin.config.LanguageFeature
-import org.jetbrains.kotlin.config.LanguageVersion
-import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.diagnostics.impl.BaseDiagnosticsCollector
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.isEnabled
 
 object FirContextParametersLanguageVersionSettingsChecker : FirLanguageVersionSettingsChecker() {
-    private val WARNING_STARTING_FROM_2_2: String = """
+    val DIAGNOSTIC_MESSAGE: String = """
         Experimental context receivers are superseded by context parameters.
         Replace the '-Xcontext-receivers' compiler argument with '-Xcontext-parameters' and migrate to the new syntax.
 
-        See the context parameters proposal for more details: https://kotl.in/context-parameters
-        This warning will become an error in future releases.""".trimIndent()
-
-    private val WARNING_BEFORE_2_2: String = """
-        Experimental context receivers are deprecated and will be superseded by context parameters.
-        Kotlin compiler version ${LanguageVersion.KOTLIN_2_2} will be the last version that supports context receivers.
-        Consider migrating to extension receivers or regular parameters now.
-        Alternatively, migrate directly to context parameters when Kotlin ${LanguageVersion.KOTLIN_2_2} is released.
-
-        See the context parameters proposal for more details: https://kotl.in/context-parameters
-        This warning will become an error in future releases.""".trimIndent()
-
-    fun getMessage(languageVersionSettings: LanguageVersionSettings): String {
-        return if (languageVersionSettings.languageVersion >= LanguageVersion.KOTLIN_2_2) {
-            WARNING_STARTING_FROM_2_2
-        } else {
-            WARNING_BEFORE_2_2
-        }
-    }
+        See the context parameters proposal for more details: https://kotl.in/context-parameters""".trimIndent()
 
     context(context: CheckerContext)
     override fun check(reporter: BaseDiagnosticsCollector.RawReporter) {
@@ -48,8 +28,8 @@ object FirContextParametersLanguageVersionSettingsChecker : FirLanguageVersionSe
                 "Experimental language features for context receivers and context parameters cannot be enabled at the same time. " +
                         "Remove the '-Xcontext-receivers' compiler argument."
             )
-        } else if (context.languageVersionSettings.languageVersion >= LanguageVersion.KOTLIN_2_2) {
-            reporter.reportWarning(WARNING_STARTING_FROM_2_2)
+        } else {
+            reporter.reportError(DIAGNOSTIC_MESSAGE)
         }
     }
 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirContextReceiversDeprecatedDeclarationChecker.kt

@@ -36,7 +36,7 @@ object FirContextReceiversDeprecatedDeclarationChecker : FirBasicDeclarationChec
             if (declaration is FirConstructor && declaration !is FirPrimaryConstructor) {
                 reporter.reportOn(declaration.source, FirErrors.CONTEXT_CLASS_OR_CONSTRUCTOR)
             } else {
-                val message = FirContextParametersLanguageVersionSettingsChecker.getMessage(context.languageVersionSettings)
+                val message = FirContextParametersLanguageVersionSettingsChecker.DIAGNOSTIC_MESSAGE
                 reporter.reportOn(declaration.source, FirErrors.CONTEXT_RECEIVERS_DEPRECATED, message)
             }
         }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/type/FirContextualFunctionTypeChecker.kt

@@ -55,7 +55,7 @@ object FirContextualFunctionTypeChecker : FirResolvedTypeRefChecker(MppCheckerKi
                     FirErrors.SUBTYPING_BETWEEN_CONTEXT_RECEIVERS
                 )
             }
-            val message = FirContextParametersLanguageVersionSettingsChecker.getMessage(context.languageVersionSettings)
+            val message = FirContextParametersLanguageVersionSettingsChecker.DIAGNOSTIC_MESSAGE
             reporter.reportOn(typeRef.source, FirErrors.CONTEXT_RECEIVERS_DEPRECATED, message)
         } else {
             source.requireFeatureSupport(LanguageFeature.ContextParameters)