Add base declaration checker for fun interfaces

compiler/testData/diagnostics/tests/funInterface/funInterfaceDeclarationCheck.fir.kt

@@ -0,0 +1,104 @@
+// !LANGUAGE: +FunctionalInterfaceConversion
+
+fun interface Good {
+    fun invoke()
+}
+
+fun interface Foo1
+
+fun interface Foo2 {
+
+}
+
+fun interface Foo3 {
+    fun foo()
+    fun bar()
+}
+
+interface BaseWithSAM {
+    fun base()
+}
+
+fun interface Foo4 : BaseWithSAM {
+    fun oneMore()
+}
+
+fun interface Foo4WithDefault : BaseWithSAM {
+    fun oneMore() {}
+}
+
+interface BaseWithDefault {
+    fun def() {}
+}
+
+fun interface Foo4WithBaseDefault : BaseWithDefault {
+    fun oneMore()
+}
+
+fun interface GoodWithBase : BaseWithSAM
+
+fun interface Foo5 {
+    val prop: Int
+}
+
+fun interface Foo6 {
+    fun foo()
+    val prop: Int
+}
+
+fun interface Foo7 : BaseWithSAM {
+    val prop: Int
+}
+
+fun interface GoodWithPropAndBase : BaseWithSAM {
+    val prop: Int get() = 42
+}
+
+fun interface Foo8 {
+    fun <T> invoke(x: T)
+}
+
+fun interface GoodGeneric<T> {
+    fun invoke(x: T)
+}
+
+interface BaseWithGeneric {
+    fun <T> invoke(x: T)
+}
+
+fun interface Foo9 : BaseWithGeneric
+
+fun interface GoodExtensionGeneric : GoodGeneric<String>
+
+fun interface GoodSuspend {
+    suspend fun invoke()
+}
+
+class WithNestedFun<K> {
+    fun interface NestedSimple
+
+    fun interface GoodFun {
+        fun invoke()
+    }
+
+    fun interface NestedFun {
+        fun inovke(element: K)
+    }
+}
+
+fun <T> local() {
+    fun interface LocalFun {
+        fun invoke(element: T)
+    }
+}
+
+fun interface WithDefaultValue {
+    fun invoke(s: String = "")
+}
+
+interface BaseWithDefaultValue {
+    fun invoke(s: String = "")
+}
+
+fun interface DeriveDefault : BaseWithDefaultValue
+

compiler/testData/diagnostics/tests/funInterface/funInterfaceDeclarationCheck.kt

@@ -0,0 +1,103 @@
+// !LANGUAGE: +FunctionalInterfaceConversion
+
+fun interface Good {
+    fun invoke()
+}
+
+<!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface Foo1
+
+<!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface Foo2 {
+
+}
+
+<!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface Foo3 {
+    fun foo()
+    fun bar()
+}
+
+interface BaseWithSAM {
+    fun base()
+}
+
+<!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface Foo4 : BaseWithSAM {
+    fun oneMore()
+}
+
+fun interface Foo4WithDefault : BaseWithSAM {
+    fun oneMore() {}
+}
+
+interface BaseWithDefault {
+    fun def() {}
+}
+
+fun interface Foo4WithBaseDefault : BaseWithDefault {
+    fun oneMore()
+}
+
+fun interface GoodWithBase : BaseWithSAM
+
+<!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface Foo5 {
+    <!FUN_INTERFACE_CANNOT_HAVE_ABSTRACT_PROPERTIES!>val<!> prop: Int
+}
+
+fun interface Foo6 {
+    fun foo()
+    <!FUN_INTERFACE_CANNOT_HAVE_ABSTRACT_PROPERTIES!>val<!> prop: Int
+}
+
+fun interface Foo7 : BaseWithSAM {
+    <!FUN_INTERFACE_CANNOT_HAVE_ABSTRACT_PROPERTIES!>val<!> prop: Int
+}
+
+fun interface GoodWithPropAndBase : BaseWithSAM {
+    val prop: Int get() = 42
+}
+
+fun interface Foo8 {
+    fun <!FUN_INTERFACE_ABSTRACT_METHOD_WITH_TYPE_PARAMETERS!><T><!> invoke(x: T)
+}
+
+fun interface GoodGeneric<T> {
+    fun invoke(x: T)
+}
+
+interface BaseWithGeneric {
+    fun <T> invoke(x: T)
+}
+
+<!FUN_INTERFACE_ABSTRACT_METHOD_WITH_TYPE_PARAMETERS!>fun<!> interface Foo9 : BaseWithGeneric
+
+fun interface GoodExtensionGeneric : GoodGeneric<String>
+
+fun interface GoodSuspend {
+    suspend fun invoke()
+}
+
+class WithNestedFun<K> {
+    <!FUN_INTERFACE_WRONG_COUNT_OF_ABSTRACT_MEMBERS!>fun<!> interface NestedSimple
+
+    fun interface GoodFun {
+        fun invoke()
+    }
+
+    fun interface NestedFun {
+        fun inovke(element: <!UNRESOLVED_REFERENCE!>K<!>)
+    }
+}
+
+fun <T> local() {
+    <!LOCAL_INTERFACE_NOT_ALLOWED!>fun interface LocalFun<!> {
+        fun invoke(element: T)
+    }
+}
+
+fun interface WithDefaultValue {
+    fun invoke(<!FUN_INTERFACE_ABSTRACT_METHOD_WITH_DEFAULT_VALUE!>s: String = ""<!>)
+}
+
+interface BaseWithDefaultValue {
+    fun invoke(s: String = "")
+}
+
+<!FUN_INTERFACE_ABSTRACT_METHOD_WITH_DEFAULT_VALUE!>fun<!> interface DeriveDefault : BaseWithDefaultValue

compiler/testData/diagnostics/tests/funInterface/funInterfaceDeclarationCheck.txt

@@ -0,0 +1,196 @@
+package
+
+public fun </*0*/ T> local(): kotlin.Unit
+
+public interface BaseWithDefault {
+    public open fun def(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface BaseWithDefaultValue {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun invoke(/*0*/ s: kotlin.String = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface BaseWithGeneric {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun </*0*/ T> invoke(/*0*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface BaseWithSAM {
+    public abstract fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface DeriveDefault : BaseWithDefaultValue {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun invoke(/*0*/ s: kotlin.String = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo3 {
+    public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo4 : BaseWithSAM {
+    public abstract override /*1*/ /*fake_override*/ fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun oneMore(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo4WithBaseDefault : BaseWithDefault {
+    public open override /*1*/ /*fake_override*/ fun def(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun oneMore(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo4WithDefault : BaseWithSAM {
+    public abstract override /*1*/ /*fake_override*/ fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open fun oneMore(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo5 {
+    public abstract val prop: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo6 {
+    public abstract val prop: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo7 : BaseWithSAM {
+    public abstract val prop: kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo8 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun </*0*/ T> invoke(/*0*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Foo9 : BaseWithGeneric {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun </*0*/ T> invoke(/*0*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface Good {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun invoke(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface GoodExtensionGeneric : GoodGeneric<kotlin.String> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun invoke(/*0*/ x: kotlin.String): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface GoodGeneric</*0*/ T> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun invoke(/*0*/ x: T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface GoodSuspend {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract suspend fun invoke(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface GoodWithBase : BaseWithSAM {
+    public abstract override /*1*/ /*fake_override*/ fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface GoodWithPropAndBase : BaseWithSAM {
+    public open val prop: kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun base(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public fun interface WithDefaultValue {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract fun invoke(/*0*/ s: kotlin.String = ...): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class WithNestedFun</*0*/ K> {
+    public constructor WithNestedFun</*0*/ K>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public fun interface GoodFun {
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public abstract fun invoke(): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public fun interface NestedFun {
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public abstract fun inovke(/*0*/ element: [ERROR : K]): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public fun interface NestedSimple {
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}