[FIR] Implement DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE diagnostic

#KT-59409 Fixed

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -1009,6 +1009,10 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
         val DATA_OBJECT_CUSTOM_EQUALS_OR_HASH_CODE by error<KtNamedFunction>(PositioningStrategy.OVERRIDE_MODIFIER)
     }
 
+    val PARAMETER_DEFAULT_VALUES by object : DiagnosticGroup("Parameter default values") {
+        val DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE by error<KtElement>()
+    }
+
     val FUN_INTERFACES by object : DiagnosticGroup("Fun interfaces") {
         val FUN_INTERFACE_CONSTRUCTOR_REFERENCE by error<KtExpression>(PositioningStrategy.REFERENCE_BY_QUALIFIED)
         val FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS by error<KtClass>(PositioningStrategy.FUN_MODIFIER)

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -527,6 +527,9 @@ object FirErrors {
     val TAIL_RECURSION_IN_TRY_IS_NOT_SUPPORTED by warning0<PsiElement>(SourceElementPositioningStrategies.REFERENCED_NAME_BY_QUALIFIED)
     val DATA_OBJECT_CUSTOM_EQUALS_OR_HASH_CODE by error0<KtNamedFunction>(SourceElementPositioningStrategies.OVERRIDE_MODIFIER)
 
+    // Parameter default values
+    val DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE by error0<KtElement>()
+
     // Fun interfaces
     val FUN_INTERFACE_CONSTRUCTOR_REFERENCE by error0<KtExpression>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
     val FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS by error0<KtClass>(SourceElementPositioningStrategies.FUN_MODIFIER)

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

@@ -217,6 +217,19 @@ object FirOverrideChecker : FirClassChecker() {
         return null
     }
 
+    @OptIn(SymbolInternals::class)
+    private fun FirFunctionSymbol<*>.checkDefaultValues(
+        reporter: DiagnosticReporter,
+        context: CheckerContext,
+    ) {
+        for (valueParameterSymbol in valueParameterSymbols) {
+            val defaultValue = valueParameterSymbol.fir.defaultValue
+            if (defaultValue != null) {
+                reporter.reportOn(defaultValue.source, FirErrors.DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE, context)
+            }
+        }
+    }
+
     private fun checkMember(
         member: FirCallableSymbol<*>,
         containingClass: FirClass,
@@ -299,6 +312,10 @@ object FirOverrideChecker : FirClassChecker() {
 
         member.checkDeprecation(reporter, overriddenMemberSymbols, context)
 
+        if (member is FirFunctionSymbol) {
+            member.checkDefaultValues(reporter, context)
+        }
+
         val restriction = member.checkReturnType(
             overriddenSymbols = overriddenMemberSymbols,
             typeCheckerState = typeCheckerState,

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrorsDefaultMessages.kt

@@ -153,6 +153,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DATA_CLASS_WITHOU
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DATA_OBJECT_CUSTOM_EQUALS_OR_HASH_CODE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DECLARATION_CANT_BE_INLINED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DEFAULT_ARGUMENTS_IN_EXPECT_WITH_ACTUAL_TYPEALIAS
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DEFINITELY_NON_NULLABLE_AS_REIFIED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATED_MEMBER_HIDES_SUPERTYPE_OVERRIDE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATED_PROPERTY_INSIDE_VALUE_CLASS
@@ -1643,6 +1644,9 @@ object FirErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
         map.put(TAIL_RECURSION_IN_TRY_IS_NOT_SUPPORTED, "Tail recursion optimization inside try/catch/finally is not supported")
         map.put(DATA_OBJECT_CUSTOM_EQUALS_OR_HASH_CODE, "Data object cannot have a custom implementation of 'equals' or 'hashCode'")
 
+        // Parameter default values
+        map.put(DEFAULT_VALUE_NOT_ALLOWED_IN_OVERRIDE, "An overriding function is not allowed to specify default values for its parameters.")
+
         // Fun interfaces
         map.put(FUN_INTERFACE_CONSTRUCTOR_REFERENCE, "Functional/SAM interface constructor references are prohibited")