FIR Java: support Java setters more properly in use-site scope

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassUseSiteMemberScope.kt

@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.fir.scopes.getContainingClassifierNamesIfPresent
 import org.jetbrains.kotlin.fir.scopes.impl.AbstractFirUseSiteMemberScope
 import org.jetbrains.kotlin.fir.symbols.CallableId
 import org.jetbrains.kotlin.fir.symbols.impl.*
+import org.jetbrains.kotlin.fir.types.isUnit
 import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.name.Name
 
@@ -58,33 +59,19 @@ class JavaClassUseSiteMemberScope(
     }
 
     private fun generateAccessorSymbol(
-        functionSymbol: FirFunctionSymbol<*>,
+        getterSymbol: FirNamedFunctionSymbol,
+        setterSymbol: FirNamedFunctionSymbol?,
         syntheticPropertyName: Name,
-        isGetter: Boolean
     ): FirAccessorSymbol? {
-        if (functionSymbol !is FirNamedFunctionSymbol) {
-            return null
-        }
-        val fir = functionSymbol.fir
-        if (fir.isStatic) {
-            return null
-        }
-        when (isGetter) {
-            true -> if (fir.valueParameters.isNotEmpty()) {
-                return null
-            }
-            false -> if (fir.valueParameters.size != 1) {
-                return null
-            }
-        }
         return buildSyntheticProperty {
             session = this@JavaClassUseSiteMemberScope.session
             name = syntheticPropertyName
             symbol = FirAccessorSymbol(
-                accessorId = functionSymbol.callableId,
+                accessorId = getterSymbol.callableId,
-                callableId = CallableId(functionSymbol.callableId.packageName, functionSymbol.callableId.className, syntheticPropertyName)
+                callableId = CallableId(getterSymbol.callableId.packageName, getterSymbol.callableId.className, syntheticPropertyName)
             )
-            delegateGetter = fir
+            delegateGetter = getterSymbol.fir
+            delegateSetter = setterSymbol?.fir
         }.symbol
     }
 
@@ -103,9 +90,28 @@ class JavaClassUseSiteMemberScope(
 
         if (klass is FirJavaClass) {
             for (getterName in getterNames) {
+                var getterSymbol: FirNamedFunctionSymbol? = null
+                var setterSymbol: FirNamedFunctionSymbol? = null
                 declaredMemberScope.processFunctionsByName(getterName) { functionSymbol ->
+                    if (getterSymbol == null && functionSymbol is FirNamedFunctionSymbol) {
+                        val function = functionSymbol.fir
+                        if (!function.isStatic && function.valueParameters.isEmpty()) {
+                            getterSymbol = functionSymbol
+                        }
+                    }
+                }
+                val setterName = session.syntheticNamesProvider.setterNameByGetterName(getterName)
+                if (getterSymbol != null && setterName != null) {
+                    declaredMemberScope.processFunctionsByName(setterName) { functionSymbol ->
+                        if (setterSymbol == null && functionSymbol is FirNamedFunctionSymbol) {
+                            val function = functionSymbol.fir
+                            if (!function.isStatic && function.returnTypeRef.isUnit && function.valueParameters.size == 1) {
+                                setterSymbol = functionSymbol
+                            }
+                        }
+                    }
                     val accessorSymbol = generateAccessorSymbol(
-                        functionSymbol, propertyName, isGetter = true
+                        getterSymbol!!, setterSymbol, propertyName
                     )
                     if (accessorSymbol != null) {
                         // NB: accessor should not be processed directly unless we find matching property symbol in supertype
@@ -158,7 +164,6 @@ class JavaClassUseSiteMemberScope(
             return processAccessorFunctionsAndPropertiesByName(name, emptyList(), processor)
         }
         val getterNames = FirJavaSyntheticNamesProvider.possibleGetterNamesByPropertyName(name)
-        val setterName = Name.identifier(SETTER_PREFIX + name.identifier.capitalize())
         return processAccessorFunctionsAndPropertiesByName(name, getterNames, processor)
     }
 
@@ -169,7 +174,8 @@ class JavaClassUseSiteMemberScope(
         val potentialPropertyName = session.syntheticNamesProvider.propertyNameByAccessorName(name)
             ?: return super.processFunctionsByName(name, processor)
         val accessors = mutableListOf<FirAccessorSymbol>()
-        processAccessorFunctionsAndPropertiesByName(potentialPropertyName, listOf(name)) {
+        val getterName = session.syntheticNamesProvider.getterNameBySetterName(name) ?: name
+        processAccessorFunctionsAndPropertiesByName(potentialPropertyName, listOf(getterName)) {
             if (it is FirAccessorSymbol) {
                 accessors += it
             }
@@ -188,8 +194,4 @@ class JavaClassUseSiteMemberScope(
             }
         }
     }
-
-    companion object {
-        private const val SETTER_PREFIX = "set"
-    }
 }

compiler/fir/jvm/src/org/jetbrains/kotlin/fir/resolve/FirJavaSyntheticNamesProvider.kt

@@ -32,16 +32,25 @@ object FirJavaSyntheticNamesProvider : FirSyntheticNamesProvider() {
         }
     }
 
-    override fun setterNameByGetterName(name: Name): Name {
+    override fun setterNameByGetterName(name: Name): Name? {
         val identifier = name.identifier
         val prefix = when {
             identifier.startsWith(GETTER_PREFIX) -> GETTER_PREFIX
             identifier.startsWith(IS_PREFIX) -> IS_PREFIX
-            else -> throw IllegalArgumentException()
+            else -> return null
         }
         return Name.identifier(SETTER_PREFIX + identifier.removePrefix(prefix))
     }
 
+    override fun getterNameBySetterName(name: Name): Name? {
+        val identifier = name.identifier
+        val prefix = when {
+            identifier.startsWith(SETTER_PREFIX) -> SETTER_PREFIX
+            else -> return null
+        }
+        return Name.identifier(GETTER_PREFIX + identifier.removePrefix(prefix))
+    }
+
     override fun propertyNameByAccessorName(name: Name): Name? {
         if (name.isSpecial) return null
         val identifier = name.identifier

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirSyntheticNamesProvider.kt

@@ -11,7 +11,8 @@ import org.jetbrains.kotlin.name.Name
 
 abstract class FirSyntheticNamesProvider : FirSessionComponent {
     abstract fun possibleGetterNamesByPropertyName(name: Name): List<Name>
-    abstract fun setterNameByGetterName(name: Name): Name
+    abstract fun setterNameByGetterName(name: Name): Name?
+    abstract fun getterNameBySetterName(name: Name): Name?
     abstract fun propertyNameByAccessorName(name: Name): Name?
 }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/Synthetics.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.fir.symbols.StandardClassIds
 import org.jetbrains.kotlin.fir.symbols.SyntheticSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.fir.types.ConeNullability.NOT_NULL
 import org.jetbrains.kotlin.name.Name
 
 class SyntheticPropertySymbol(
@@ -64,15 +65,19 @@ class FirSyntheticPropertiesScope(
         var matchingSetter: FirSimpleFunction? = null
         if (getterReturnType != null) {
             val setterName = syntheticNamesProvider.setterNameByGetterName(getterName)
-            baseScope.processFunctionsByName(setterName, fun(setterSymbol: FirFunctionSymbol<*>) {
+            if (setterName != null) {
-                if (matchingSetter != null) return
+                baseScope.processFunctionsByName(setterName, fun(setterSymbol: FirFunctionSymbol<*>) {
-                val setter = setterSymbol.fir as? FirSimpleFunction ?: return
+                    if (matchingSetter != null) return
-                val parameter = setter.valueParameters.singleOrNull() ?: return
+                    val setter = setterSymbol.fir as? FirSimpleFunction ?: return
-                if (setter.typeParameters.isNotEmpty() || setter.isStatic) return
+                    val parameter = setter.valueParameters.singleOrNull() ?: return
-                val parameterType = (parameter.returnTypeRef as? FirResolvedTypeRef)?.type ?: return
+                    if (setter.typeParameters.isNotEmpty() || setter.isStatic) return
-                if (getterReturnType.withNullability(ConeNullability.NOT_NULL) != parameterType.withNullability(ConeNullability.NOT_NULL)) return
+                    val parameterType = (parameter.returnTypeRef as? FirResolvedTypeRef)?.type ?: return
-                matchingSetter = setter
+                    if (getterReturnType.withNullability(NOT_NULL) != parameterType.withNullability(NOT_NULL)) {
-            })
+                        return
+                    }
+                    matchingSetter = setter
+                })
+            }
         }
 
         val property = buildSyntheticProperty {