[FIR] Improve synthetic functional interfaces support

Rename fictitiousFunctionSymbols -> syntheticFunctionalInterfaceSymbols
Support suspend function interfaces
Add supertypes for KFunction / KSuspendFunction

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/impl/FirLibrarySymbolProviderImpl.kt

@@ -18,13 +18,14 @@ import org.jetbrains.kotlin.fir.deserialization.FirBuiltinAnnotationDeserializer
 import org.jetbrains.kotlin.fir.deserialization.FirDeserializationContext
 import org.jetbrains.kotlin.fir.deserialization.deserializeClassToSymbol
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.ScopeSession
+import org.jetbrains.kotlin.fir.resolve.constructClassType
 import org.jetbrains.kotlin.fir.resolve.getOrPut
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.KotlinScopeProvider
 import org.jetbrains.kotlin.fir.scopes.impl.nestedClassifierScope
 import org.jetbrains.kotlin.fir.symbols.CallableId
 import org.jetbrains.kotlin.fir.symbols.impl.*
+import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
 import org.jetbrains.kotlin.fir.types.impl.FirResolvedTypeRefImpl
 import org.jetbrains.kotlin.metadata.ProtoBuf
@@ -132,17 +133,20 @@ class FirLibrarySymbolProviderImpl(val session: FirSession, val kotlinScopeProvi
 
     private val allPackageFragments = loadBuiltIns().groupBy { it.fqName }
 
-    private val fictitiousFunctionSymbols = mutableMapOf<Int, FirRegularClassSymbol>()
+    private data class SyntheticFunctionalInterfaceSymbolKey(val kind: FunctionClassDescriptor.Kind, val arity: Int)
 
-    override fun getClassLikeSymbolByFqName(classId: ClassId): FirRegularClassSymbol? {
+    private val syntheticFunctionalInterfaceSymbols = mutableMapOf<SyntheticFunctionalInterfaceSymbolKey, FirRegularClassSymbol>()
-        return allPackageFragments[classId.packageFqName]?.firstNotNullResult {
+
-            it.getClassLikeSymbolByFqName(classId)
+
-        } ?: with(classId) {
+    private fun FunctionClassDescriptor.Kind.classId(arity: Int) = ClassId(packageFqName, numberedClassName(arity))
+
+    private fun trySyntheticFunctionalInterface(classId: ClassId): FirRegularClassSymbol? {
+        return with(classId) {
             val className = relativeClassName.asString()
             val kind = FunctionClassDescriptor.Kind.byClassNamePrefix(packageFqName, className) ?: return@with null
             val prefix = kind.classNamePrefix
             val arity = className.substring(prefix.length).toIntOrNull() ?: return null
-            fictitiousFunctionSymbols.getOrPut(arity) {
+            syntheticFunctionalInterfaceSymbols.getOrPut(SyntheticFunctionalInterfaceSymbolKey(kind, arity)) {
                 val status = FirDeclarationStatusImpl(Visibilities.PUBLIC, Modality.ABSTRACT).apply {
                     isExpect = false
                     isActual = false
@@ -187,7 +191,7 @@ class FirLibrarySymbolProviderImpl(val session: FirSession, val kotlinScopeProvi
                             }
                         )
                         val name = OperatorNameConventions.INVOKE
-                        val status = FirDeclarationStatusImpl(Visibilities.PUBLIC, Modality.ABSTRACT).apply {
+                        val functionStatus = FirDeclarationStatusImpl(Visibilities.PUBLIC, Modality.ABSTRACT).apply {
                             isExpect = false
                             isActual = false
                             isOverride = false
@@ -196,36 +200,36 @@ class FirLibrarySymbolProviderImpl(val session: FirSession, val kotlinScopeProvi
                             isInline = false
                             isTailRec = false
                             isExternal = false
-                            isSuspend = false
+                            isSuspend =
+                                kind == FunctionClassDescriptor.Kind.SuspendFunction ||
+                                        kind == FunctionClassDescriptor.Kind.KSuspendFunction
                         }
+                        val typeArguments = typeParameters.map {
+                            FirResolvedTypeRefImpl(
+                                null,
+                                ConeTypeParameterTypeImpl(it.symbol.toLookupTag(), false)
+                            )
+                        }
+
                         addDeclaration(
                             FirSimpleFunctionImpl(
                                 null,
                                 this@FirLibrarySymbolProviderImpl.session,
-                                FirResolvedTypeRefImpl(
+                                typeArguments.last(),
-                                    null,
-                                    ConeTypeParameterTypeImpl(
-                                        typeParameters.last().symbol.toLookupTag(),
-                                        false
-                                    )
-                                ),
                                 null,
                                 name,
-                                status,
+                                functionStatus,
                                 FirNamedFunctionSymbol(CallableId(packageFqName, relativeClassName, name))
                             ).apply {
                                 resolvePhase = FirResolvePhase.DECLARATIONS
-                                valueParameters += this@klass.typeParameters.dropLast(1).map { typeParameter ->
+                                valueParameters += typeArguments.dropLast(1).mapIndexed { index, typeArgument ->
-                                    val name = Name.identifier(typeParameter.name.asString().toLowerCase())
+                                    val parameterName = Name.identifier("p${index + 1}")
                                     FirValueParameterImpl(
                                         null,
                                         this@FirLibrarySymbolProviderImpl.session,
-                                        FirResolvedTypeRefImpl(
+                                        typeArgument,
-                                            null,
+                                        parameterName,
-                                            ConeTypeParameterTypeImpl(typeParameter.symbol.toLookupTag(), false)
+                                        FirVariableSymbol(parameterName),
-                                        ),
-                                        name,
-                                        FirVariableSymbol(name),
                                         defaultValue = null,
                                         isCrossinline = false,
                                         isNoinline = false,
@@ -234,13 +238,43 @@ class FirLibrarySymbolProviderImpl(val session: FirSession, val kotlinScopeProvi
                                 }
                             }
                         )
-                        replaceSuperTypeRefs(listOf(session.builtinTypes.anyType))
+
+                        fun createSuperType(
+                            kind: FunctionClassDescriptor.Kind
+                        ): FirResolvedTypeRef {
+                            return FirResolvedTypeRefImpl(
+                                null,
+                                ConeClassLikeLookupTagImpl(kind.classId(arity))
+                                    .constructClassType(typeArguments.map { it.type }.toTypedArray(), isNullable = false)
+                            )
+                        }
+
+                        val superTypes = when (kind) {
+
+                            FunctionClassDescriptor.Kind.Function,
+                            FunctionClassDescriptor.Kind.SuspendFunction ->
+                                listOf(session.builtinTypes.anyType)
+
+                            FunctionClassDescriptor.Kind.KFunction ->
+                                listOf(createSuperType(FunctionClassDescriptor.Kind.Function))
+                            FunctionClassDescriptor.Kind.KSuspendFunction ->
+                                listOf(createSuperType(FunctionClassDescriptor.Kind.SuspendFunction))
+                        }
+                        replaceSuperTypeRefs(superTypes)
+
                     }
                 }
             }
         }
     }
 
+
+    override fun getClassLikeSymbolByFqName(classId: ClassId): FirRegularClassSymbol? {
+        return allPackageFragments[classId.packageFqName]?.firstNotNullResult {
+            it.getClassLikeSymbolByFqName(classId)
+        } ?: trySyntheticFunctionalInterface(classId)
+    }
+
     override fun getTopLevelCallableSymbols(packageFqName: FqName, name: Name): List<FirCallableSymbol<*>> {
         return allPackageFragments[packageFqName]?.flatMap {
             it.getTopLevelCallableSymbols(name)

compiler/fir/resolve/testData/resolve/stdlib/callableReferences/fromBasicDiagnosticTests/moreSpecificAmbiguousExtensions.txt

@@ -12,9 +12,9 @@ FILE: moreSpecificAmbiguousExtensions.kt
         lval extFun2: R|kotlin/reflect/KFunction2<IB, IB, kotlin/Unit>| = Q|IB|::R|/extFun|
     }
     public final fun testWithExpectedType(): R|kotlin/Unit| {
-        lval extFun_AB_A: @R|kotlin/ExtensionFunctionType|() R|kotlin/reflect/KFunction2<IA, IB, kotlin/Unit>| = Q|IA|::R|/extFun|
+        lval extFun_AB_A: R|IA.(IB) -> kotlin/Unit| = Q|IA|::R|/extFun|
-        lval extFun_AA_B: @R|kotlin/ExtensionFunctionType|() R|kotlin/reflect/KFunction2<IA, IA, kotlin/Unit>| = Q|IB|::R|/extFun|
+        lval extFun_AA_B: R|IA.(IA) -> kotlin/Unit| = Q|IB|::R|/extFun|
-        lval extFun_BB_A: @R|kotlin/ExtensionFunctionType|() R|kotlin/reflect/KFunction2<IB, IB, kotlin/Unit>| = Q|IA|::R|/extFun|
+        lval extFun_BB_A: R|IB.(IB) -> kotlin/Unit| = Q|IA|::R|/extFun|
-        lval extFun_BA_B: @R|kotlin/ExtensionFunctionType|() R|kotlin/reflect/KFunction2<IB, IA, kotlin/Unit>| = Q|IB|::R|/extFun|
+        lval extFun_BA_B: R|IB.(IA) -> kotlin/Unit| = Q|IB|::R|/extFun|
-        lval extFun_BB_B: @R|kotlin/ExtensionFunctionType|() R|kotlin/reflect/KFunction2<IB, IB, kotlin/Unit>| = Q|IB|::R|/extFun|
+        lval extFun_BB_B: R|IB.(IB) -> kotlin/Unit| = Q|IB|::R|/extFun|
     }

compiler/testData/codegen/box/casts/functions/asFunKSmall.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // TODO: muted automatically, investigate should it be ran for JS or not
 // IGNORE_BACKEND: JS, NATIVE

compiler/testData/codegen/box/casts/functions/reifiedAsFunKSmall.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // TODO: muted automatically, investigate should it be ran for JS or not
 // IGNORE_BACKEND: JS, NATIVE

compiler/testData/codegen/box/casts/functions/reifiedSafeAsFunKSmall.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // TODO: muted automatically, investigate should it be ran for JS or not
 // IGNORE_BACKEND: JS

compiler/testData/ir/irText/expressions/callableReferenceTypeArguments.fir.txt

@@ -34,7 +34,7 @@ FILE fqName:<root> fileName:/callableReferenceTypeArguments.kt
   PROPERTY name:test1 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test1 type:kotlin.Function1<kotlin.Int, kotlin.Unit> visibility:private [final,static]
       EXPRESSION_BODY
-        FUNCTION_REFERENCE 'public final fun topLevel1 <T> (x: T of <root>.topLevel1): kotlin.Unit [inline] declared in <root>' type=kotlin.Function1<kotlin.Int, kotlin.Unit> origin=null
+        FUNCTION_REFERENCE 'public final fun topLevel1 <T> (x: T of <root>.topLevel1): kotlin.Unit [inline] declared in <root>' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test1> visibility:public modality:FINAL <> () returnType:kotlin.Function1<kotlin.Int, kotlin.Unit>
       correspondingProperty: PROPERTY name:test1 visibility:public modality:FINAL [val]
       BLOCK_BODY
@@ -43,7 +43,7 @@ FILE fqName:<root> fileName:/callableReferenceTypeArguments.kt
   PROPERTY name:test2 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function1<kotlin.collections.List<kotlin.String>, kotlin.Unit> visibility:private [final,static]
       EXPRESSION_BODY
-        FUNCTION_REFERENCE 'public final fun topLevel2 <T> (x: kotlin.collections.List<T of <root>.topLevel2>): kotlin.Unit [inline] declared in <root>' type=kotlin.Function1<kotlin.collections.List<kotlin.String>, kotlin.Unit> origin=null
+        FUNCTION_REFERENCE 'public final fun topLevel2 <T> (x: kotlin.collections.List<T of <root>.topLevel2>): kotlin.Unit [inline] declared in <root>' type=kotlin.reflect.KFunction1<kotlin.collections.List<kotlin.String>, kotlin.Unit> origin=null
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test2> visibility:public modality:FINAL <> () returnType:kotlin.Function1<kotlin.collections.List<kotlin.String>, kotlin.Unit>
       correspondingProperty: PROPERTY name:test2 visibility:public modality:FINAL [val]
       BLOCK_BODY
@@ -52,7 +52,7 @@ FILE fqName:<root> fileName:/callableReferenceTypeArguments.kt
   PROPERTY name:test3 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test3 type:kotlin.Function1<kotlin.Int, kotlin.Unit> visibility:private [final,static]
       EXPRESSION_BODY
-        FUNCTION_REFERENCE 'public final fun objectMember <T> (x: T of <root>.Host.objectMember): kotlin.Unit [inline] declared in <root>.Host' type=kotlin.Function1<kotlin.Int, kotlin.Unit> origin=null
+        FUNCTION_REFERENCE 'public final fun objectMember <T> (x: T of <root>.Host.objectMember): kotlin.Unit [inline] declared in <root>.Host' type=kotlin.reflect.KFunction1<kotlin.Int, kotlin.Unit> origin=null
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test3> visibility:public modality:FINAL <> () returnType:kotlin.Function1<kotlin.Int, kotlin.Unit>
       correspondingProperty: PROPERTY name:test3 visibility:public modality:FINAL [val]
       BLOCK_BODY

compiler/testData/ir/irText/expressions/sam/samConstructors.fir.txt

@@ -19,7 +19,7 @@ FILE fqName:<root> fileName:/samConstructors.kt
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test3 (): java.lang.Runnable declared in <root>'
         CALL 'public final fun Runnable (block: kotlin.Function0<kotlin.Unit>): java.lang.Runnable declared in java.lang' type=java.lang.Runnable origin=null
-          block: FUNCTION_REFERENCE 'public final fun foo (): kotlin.Unit declared in <root>' type=kotlin.Function0<kotlin.Unit> origin=null
+          block: FUNCTION_REFERENCE 'public final fun foo (): kotlin.Unit declared in <root>' type=kotlin.reflect.KFunction0<kotlin.Unit> origin=null
   FUN name:test4 visibility:public modality:FINAL <> () returnType:java.util.Comparator<kotlin.Int>
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test4 (): java.util.Comparator<kotlin.Int> declared in <root>'

compiler/testData/ir/irText/expressions/sam/samConversionsWithSmartCasts.fir.txt

@@ -91,4 +91,4 @@ FILE fqName:<root> fileName:/samConversionsWithSmartCasts.kt
     BLOCK_BODY
       CALL 'public open fun run1 (r: java.lang.Runnable?): kotlin.Unit [operator] declared in <root>.J' type=kotlin.Unit origin=null
         $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.J' type=<root>.J origin=null
-        r: FUNCTION_REFERENCE 'public final fun test9 (): kotlin.Unit declared in <root>' type=kotlin.Function0<kotlin.Unit> origin=null
+        r: FUNCTION_REFERENCE 'public final fun test9 (): kotlin.Unit declared in <root>' type=kotlin.reflect.KFunction0<kotlin.Unit> origin=null

compiler/testData/ir/irText/expressions/typeAliasConstructorReference.fir.txt

@@ -61,7 +61,7 @@ FILE fqName:<root> fileName:/typeAliasConstructorReference.kt
   PROPERTY name:test1 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test1 type:kotlin.Function1<kotlin.Int, <root>.C> visibility:private [final,static]
       EXPRESSION_BODY
-        FUNCTION_REFERENCE 'public constructor <init> (x: kotlin.Int) [primary] declared in <root>.C' type=kotlin.Function1<kotlin.Int, <root>.C> origin=null
+        FUNCTION_REFERENCE 'public constructor <init> (x: kotlin.Int) [primary] declared in <root>.C' type=kotlin.reflect.KFunction1<kotlin.Int, <root>.C> origin=null
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test1> visibility:public modality:FINAL <> () returnType:kotlin.Function1<kotlin.Int, <root>.C>
       correspondingProperty: PROPERTY name:test1 visibility:public modality:FINAL [val]
       BLOCK_BODY
@@ -70,7 +70,7 @@ FILE fqName:<root> fileName:/typeAliasConstructorReference.kt
   PROPERTY name:test2 visibility:public modality:FINAL [val]
     FIELD PROPERTY_BACKING_FIELD name:test2 type:kotlin.Function1<kotlin.Int, <root>.Host.Nested> visibility:private [final,static]
       EXPRESSION_BODY
-        FUNCTION_REFERENCE 'public constructor <init> (x: kotlin.Int) [primary] declared in <root>.Host.Nested' type=kotlin.Function1<kotlin.Int, <root>.Host.Nested> origin=null
+        FUNCTION_REFERENCE 'public constructor <init> (x: kotlin.Int) [primary] declared in <root>.Host.Nested' type=kotlin.reflect.KFunction1<kotlin.Int, <root>.Host.Nested> origin=null
     FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test2> visibility:public modality:FINAL <> () returnType:kotlin.Function1<kotlin.Int, <root>.Host.Nested>
       correspondingProperty: PROPERTY name:test2 visibility:public modality:FINAL [val]
       BLOCK_BODY