Implicit nothing / intersection types are now checked also for member functions #KT-11666 Fixed

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

@@ -349,6 +349,7 @@ class DeclarationsChecker(
             if (memberDescriptor.kind != CallableMemberDescriptor.Kind.DECLARATION) continue
             val member = DescriptorToSourceUtils.descriptorToDeclaration(memberDescriptor) as? KtFunction
             if (member != null && memberDescriptor is FunctionDescriptor) {
+                checkImplicitCallableType(member, memberDescriptor)
                 checkFunctionExposedType(member, memberDescriptor)
                 checkVarargParameters(trace, memberDescriptor)
             }
@@ -689,14 +690,15 @@ class DeclarationsChecker(
             if (!hasBody && !hasAbstractModifier && !hasExternalModifier && !inTrait) {
                 trace.report(NON_ABSTRACT_FUNCTION_WITH_NO_BODY.on(function, functionDescriptor))
             }
-            return
         }
-        if (!function.hasBody() && !hasAbstractModifier && !hasExternalModifier) {
-            trace.report(NON_MEMBER_FUNCTION_NO_BODY.on(function, functionDescriptor))
+        else /* top-level only */ {
+            if (!function.hasBody() && !hasAbstractModifier && !hasExternalModifier) {
+                trace.report(NON_MEMBER_FUNCTION_NO_BODY.on(function, functionDescriptor))
+            }
+            checkImplicitCallableType(function, functionDescriptor)
+            checkFunctionExposedType(function, functionDescriptor)
+            checkVarargParameters(trace, functionDescriptor)
         }
-        checkImplicitCallableType(function, functionDescriptor)
-        checkFunctionExposedType(function, functionDescriptor)
-        checkVarargParameters(trace, functionDescriptor)
     }
 
     private fun checkImplicitCallableType(declaration: KtCallableDeclaration, descriptor: CallableDescriptor) {

compiler/testData/codegen/box/typeMapping/kt3863.kt

@@ -4,7 +4,7 @@ import kotlin.reflect.KProperty
 
 class NotImplemented<T>(){
     operator fun getValue(thisRef: Any?, prop: KProperty<*>): T = notImplemented()
-    operator fun setValue(thisRef: Any?, prop: KProperty<*>, value: T) = notImplemented()
+    operator fun setValue(thisRef: Any?, prop: KProperty<*>, value: T): Nothing = notImplemented()
 }
 
 fun notImplemented() : Nothing = notImplemented()

compiler/testData/codegen/properties/privateClassPropertyAccessors.kt

@@ -27,7 +27,7 @@ class C {
 
 
 object Delegate {
-    operator fun getValue(x: C, p: KProperty<*>) = throw AssertionError()
+    operator fun getValue(x: C, p: KProperty<*>): Nothing = throw AssertionError()
 
-    operator fun setValue(x: C, p: KProperty<*>, value: Int) = throw AssertionError()
+    operator fun setValue(x: C, p: KProperty<*>, value: Int): Nothing = throw AssertionError()
 }

compiler/testData/diagnostics/tests/implicitIntersection.kt

@@ -14,6 +14,8 @@ class My(b: B) {
     val <!IMPLICIT_INTERSECTION_TYPE!>x<!> = if (b is A && b is C) b else null
     // Ok: given explicitly
     val y: C? = if (b is A && b is C) <!DEBUG_INFO_SMARTCAST!>b<!> else null
+    // Error!
+    fun <!IMPLICIT_INTERSECTION_TYPE!>foo<!>(b: B) = if (b is A && b is C) b else null
 }
 
 fun bar(b: B): String {

compiler/testData/diagnostics/tests/implicitIntersection.txt

@@ -28,6 +28,7 @@ public final class My {
     public final val x: {C & A & B}?
     public final val y: C?
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(/*0*/ b: B): {C & A & B}?
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

compiler/testData/diagnostics/tests/implicitNothing.kt

@@ -16,3 +16,21 @@ fun check() {
     // Unreachable / unused, but not implicit Nothing
     <!UNREACHABLE_CODE!>val <!UNUSED_VARIABLE!>x<!> =<!> null!!
 }
+
+class Klass {
+    fun <!IMPLICIT_NOTHING_RETURN_TYPE!>bar<!>() = null!!
+
+    val <!IMPLICIT_NOTHING_PROPERTY_TYPE!>y<!> = null!!
+
+    init {
+        fun <!IMPLICIT_NOTHING_RETURN_TYPE!>local<!>() = bar()
+        // Should be unreachable: see KT-5311
+        val z = null!!
+    }
+
+    fun foo() {
+        fun <!IMPLICIT_NOTHING_RETURN_TYPE!>local<!>() = bar()
+
+        <!UNREACHABLE_CODE!>val <!UNUSED_VARIABLE!>x<!> =<!> y
+    }
+}

compiler/testData/diagnostics/tests/implicitNothing.txt

@@ -7,3 +7,13 @@ public fun baz(): kotlin.Nothing
 public fun check(): kotlin.Unit
 public fun foo(): kotlin.Nothing
 public fun gav(): kotlin.Any
+
+public final class Klass {
+    public constructor Klass()
+    public final val y: kotlin.Nothing
+    public final fun bar(): kotlin.Nothing
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/loadJava/compiledKotlin/annotations/classMembers/DelegatedProperty.kt

@@ -6,6 +6,6 @@ annotation class Anno
 
 class Class {
     @Anno val x: Int by object {
-        operator fun getValue(thiz: Class, data: KProperty<*>) = null!!
+        operator fun getValue(thiz: Class, data: KProperty<*>): Nothing = null!!
     }
 }

compiler/testData/loadJava/compiledKotlin/annotations/packageMembers/DelegatedProperty.kt

@@ -8,5 +8,5 @@ import kotlin.reflect.KProperty
 annotation class Anno
 
 @Anno val x: Int by object {
-    operator fun getValue(thiz: Any?, data: KProperty<*>) = null!!
+    operator fun getValue(thiz: Any?, data: KProperty<*>): Nothing = null!!
 }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/typeEnhancement/typeEnhancement.kt

@@ -213,7 +213,7 @@ private class EnhancedTypeAnnotations(private val fqNameToMatch: FqName) : Annot
 }
 
 private object EnhancedTypeAnnotationDescriptor : AnnotationDescriptor {
-    private fun throwError() = error("No methods should be called on this descriptor. Only its presence matters")
+    private fun throwError(): Nothing = error("No methods should be called on this descriptor. Only its presence matters")
     override fun getType() = throwError()
     override fun getAllValueArguments() = throwError()
     override fun getSource() = throwError()

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KFunctionFromReferenceImpl.kt

@@ -76,6 +76,6 @@ internal object EmptyContainerForLocal : KDeclarationContainerImpl() {
 
     override fun getFunctions(name: Name): Collection<FunctionDescriptor> = fail()
 
-    private fun fail() = throw KotlinReflectionInternalError("Introspecting local functions, lambdas and anonymous functions " +
+    private fun fail(): Nothing = throw KotlinReflectionInternalError("Introspecting local functions, lambdas and anonymous functions " +
                                                              "is not yet fully supported in Kotlin reflection")
 }

idea/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinEvaluationBuilder.kt

@@ -440,9 +440,9 @@ class KotlinEvaluator(val codeFragment: KtCodeFragment, val sourcePosition: Sour
             }
         }
 
-        private fun exception(msg: String) = throw EvaluateExceptionUtil.createEvaluateException(msg)
+        private fun exception(msg: String): Nothing = throw EvaluateExceptionUtil.createEvaluateException(msg)
 
-        private fun exception(e: Throwable) = throw EvaluateExceptionUtil.createEvaluateException(e)
+        private fun exception(e: Throwable): Nothing = throw EvaluateExceptionUtil.createEvaluateException(e)
 
         // contextFile must be NotNull when analyzeInlineFunctions = true
         private fun KtFile.checkForErrors(analyzeInlineFunctions: Boolean = false, contextFile: KtFile? = null): ExtendedAnalysisResult {

idea/testData/intentions/convertFunctionToProperty/nothingFun.kt

@@ -1,7 +1,7 @@
 // WITH_RUNTIME
 // IS_APPLICABLE: false
 class A(val n: Int) {
-    fun <caret>foo() = throw Exception("foo")
+    fun <caret>foo(): Nothing = throw Exception("foo")
 }
 
 fun test() {