Fix multiple exceptions related to subtypes of function types

The main change is in FunctionsTypingVisitor#visitLambdaExpression, where we
incorrectly allowed subtypes of function types to be expected type during
resolution of lambdas

Also see EA-70485

 #KT-9820 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt

@@ -16,10 +16,7 @@
 
 package org.jetbrains.kotlin.resolve
 
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.*
-import org.jetbrains.kotlin.builtins.getReceiverTypeFromFunctionType
-import org.jetbrains.kotlin.builtins.getValueParametersFromFunctionType
-import org.jetbrains.kotlin.builtins.isFunctionTypeOrSubtype
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.ConstructorDescriptorImpl
@@ -220,12 +217,15 @@ class FunctionDescriptorResolver(
         )
     }
 
-    private fun KotlinType.functionTypeExpected() = !TypeUtils.noExpectedType(this) && isFunctionTypeOrSubtype
+    private fun KotlinType.functionTypeExpected() = !TypeUtils.noExpectedType(this) && isFunctionType
     private fun KotlinType.getReceiverType(): KotlinType? =
             if (functionTypeExpected()) getReceiverTypeFromFunctionType(this) else null
 
     private fun KotlinType.getValueParameters(owner: FunctionDescriptor): List<ValueParameterDescriptor>? =
-            if (functionTypeExpected()) getValueParametersFromFunctionType(owner, this) else null
+            if (functionTypeExpected()) {
+                createValueParametersFromFunctionType(owner, getParameterTypeProjectionsFromFunctionType(this))
+            }
+            else null
 
     fun resolvePrimaryConstructorDescriptor(
             scope: LexicalScope,

compiler/frontend/src/org/jetbrains/kotlin/resolve/callableReferences/CallableReferencesResolutionUtils.kt

@@ -16,7 +16,10 @@
 
 package org.jetbrains.kotlin.resolve.callableReferences
 
-import org.jetbrains.kotlin.builtins.*
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.ReflectionTypes
+import org.jetbrains.kotlin.builtins.createFunctionType
+import org.jetbrains.kotlin.builtins.createValueParametersFromFunctionType
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.AnonymousFunctionDescriptor
@@ -210,11 +213,9 @@ private fun bindFunctionReference(expression: KtCallableReferenceExpression, typ
     )
 
     functionDescriptor.initialize(
-            getReceiverTypeFromFunctionType(type),
+            null, null, emptyList(),
-            null,
+            createValueParametersFromFunctionType(functionDescriptor, type.arguments.dropLast(1)),
-            emptyList(),
+            type.arguments.last().type,
-            getValueParametersFromFunctionType(functionDescriptor, type),
-            getReturnTypeFromFunctionType(type),
             Modality.FINAL,
             Visibilities.PUBLIC
     )

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/FunctionsTypingVisitor.kt

@@ -21,7 +21,7 @@ import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.createFunctionType
 import org.jetbrains.kotlin.builtins.getReturnTypeFromFunctionType
-import org.jetbrains.kotlin.builtins.isFunctionTypeOrSubtype
+import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
@@ -140,7 +140,7 @@ internal class FunctionsTypingVisitor(facade: ExpressionTypingInternals) : Expre
         if (!expression.functionLiteral.hasBody()) return null
 
         val expectedType = context.expectedType
-        val functionTypeExpected = !noExpectedType(expectedType) && expectedType.isFunctionTypeOrSubtype
+        val functionTypeExpected = !noExpectedType(expectedType) && expectedType.isFunctionType
 
         val functionDescriptor = createFunctionLiteralDescriptor(expression, context)
         expression.valueParameters.forEach {

compiler/testData/diagnostics/testsWithStdLib/regression/ea70485_functionTypeInheritor.kt

@@ -0,0 +1,17 @@
+class O : Function2<Int, String, Unit> {
+    override fun invoke(p1: Int, p2: String) {
+    }
+}
+
+fun test() {
+    val a = fun(<!UNUSED_PARAMETER!>o<!>: O) {
+    }
+    a <!TYPE_MISMATCH!>{}<!>
+}
+
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Ext<!> : <!SUPERTYPE_IS_EXTENSION_FUNCTION_TYPE!>String.() -> Unit<!> {
+}
+
+fun test2() {
+    val <!UNUSED_VARIABLE!>f<!>: Ext = <!TYPE_MISMATCH!>{}<!>
+}

compiler/testData/diagnostics/testsWithStdLib/regression/ea70485_functionTypeInheritor.txt

@@ -0,0 +1,20 @@
+package
+
+public fun test(): kotlin.Unit
+public fun test2(): kotlin.Unit
+
+public final class Ext : kotlin.String.() -> kotlin.Unit {
+    public constructor Ext()
+    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*/ p1: kotlin.String): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class O : (kotlin.Int, kotlin.String) -> kotlin.Unit {
+    public constructor O()
+    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*/ fun invoke(/*0*/ p1: kotlin.Int, /*1*/ p2: kotlin.String): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/regression/kt9820_javaFunctionTypeInheritor.kt

@@ -0,0 +1,16 @@
+// FILE: J.java
+
+import kotlin.jvm.functions.Function1;
+
+public interface J extends Function1<Integer, Void> {
+}
+
+// FILE: 1.kt
+
+fun useJ(j: J) {
+    j(42)
+}
+
+fun jj() {
+    useJ(<!TYPE_MISMATCH!>{}<!>)
+}

compiler/testData/diagnostics/testsWithStdLib/regression/kt9820_javaFunctionTypeInheritor.txt

@@ -0,0 +1,12 @@
+package
+
+public /*synthesized*/ fun J(/*0*/ function: (kotlin.Int!) -> java.lang.Void!): J
+public fun jj(): kotlin.Unit
+public fun useJ(/*0*/ j: J): kotlin.Unit
+
+public interface J : (kotlin.Int!) -> java.lang.Void! {
+    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*/ p1: kotlin.Int!): java.lang.Void!
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java

@@ -1036,6 +1036,12 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
             doTest(fileName);
         }
 
+        @TestMetadata("ea70485_functionTypeInheritor.kt")
+        public void testEa70485_functionTypeInheritor() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/regression/ea70485_functionTypeInheritor.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("ea70880_illegalJvmName.kt")
         public void testEa70880_illegalJvmName() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/regression/ea70880_illegalJvmName.kt");
@@ -1053,6 +1059,12 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/regression/kt9345.kt");
             doTest(fileName);
         }
+
+        @TestMetadata("kt9820_javaFunctionTypeInheritor.kt")
+        public void testKt9820_javaFunctionTypeInheritor() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/testsWithStdLib/regression/kt9820_javaFunctionTypeInheritor.kt");
+            doTest(fileName);
+        }
     }
 
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/reified")

core/descriptors/src/org/jetbrains/kotlin/builtins/functionTypes.kt

@@ -63,16 +63,14 @@ fun isNumberedFunctionClassFqName(fqName: FqNameUnsafe): Boolean {
 }
 
 fun getReceiverTypeFromFunctionType(type: KotlinType): KotlinType? {
-    assert(type.isFunctionTypeOrSubtype) { type }
+    assert(type.isFunctionType) { "Not a function type: $type" }
-    if (type.isExtensionFunctionType) {
+    return if (type.isTypeAnnotatedWithExtensionFunctionType) type.arguments.first().type else null
-        return type.arguments.first().type
-    }
-    return null
 }
 
-fun getValueParametersFromFunctionType(functionDescriptor: FunctionDescriptor, type: KotlinType): List<ValueParameterDescriptor> {
+fun createValueParametersFromFunctionType(
-    assert(type.isFunctionTypeOrSubtype) { type }
+        functionDescriptor: FunctionDescriptor, parameterTypes: List<TypeProjection>
-    return getParameterTypeProjectionsFromFunctionType(type).mapIndexed { i, typeProjection ->
+): List<ValueParameterDescriptor> {
+    return parameterTypes.mapIndexed { i, typeProjection ->
         ValueParameterDescriptorImpl(
                 functionDescriptor, null, i, Annotations.EMPTY,
                 Name.identifier("p${i + 1}"), typeProjection.type,
@@ -85,22 +83,17 @@ fun getValueParametersFromFunctionType(functionDescriptor: FunctionDescriptor, t
 }
 
 fun getReturnTypeFromFunctionType(type: KotlinType): KotlinType {
-    assert(type.isFunctionTypeOrSubtype) { type }
+    assert(type.isFunctionType) { "Not a function type: $type" }
     return type.arguments.last().type
 }
 
 fun getParameterTypeProjectionsFromFunctionType(type: KotlinType): List<TypeProjection> {
-    assert(type.isFunctionTypeOrSubtype) { type }
+    assert(type.isFunctionType) { "Not a function type: $type" }
     val arguments = type.arguments
     val first = if (type.isExtensionFunctionType) 1 else 0
-    val last = arguments.size - 2
+    val last = arguments.size - 1
-    // TODO: fix bugs associated with this here and in neighboring methods, see KT-9820
+    assert(first <= last) { "Not an exact function type: $type" }
-    assert(first <= last + 1) { "Not an exact function type: $type" }
+    return arguments.subList(first, last)
-    val parameterTypes = ArrayList<TypeProjection>(last - first + 1)
-    for (i in first..last) {
-        parameterTypes.add(arguments[i])
-    }
-    return parameterTypes
 }
 
 fun createFunctionType(