Implicit callable type check refactoring, additional check for property with explicit Nothing type

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -727,6 +727,7 @@ public interface Errors {
     DiagnosticFactory2<KtElement, KotlinType, KotlinType> INCOMPATIBLE_TYPES = DiagnosticFactory2.create(ERROR);
 
     DiagnosticFactory0<PsiElement> IMPLICIT_NOTHING_RETURN_TYPE = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<PsiElement> IMPLICIT_NOTHING_PROPERTY_TYPE = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory1<PsiElement, KotlinType> IMPLICIT_INTERSECTION_TYPE = DiagnosticFactory1.create(ERROR);
 
     // Context tracking

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -527,6 +527,7 @@ public class DefaultErrorMessages {
         MAP.put(TYPE_MISMATCH_IN_CONDITION, "Condition must be of type kotlin.Boolean, but is of type {0}", RENDER_TYPE);
         MAP.put(INCOMPATIBLE_TYPES, "Incompatible types: {0} and {1}", RENDER_TYPE, RENDER_TYPE);
         MAP.put(IMPLICIT_NOTHING_RETURN_TYPE, "''Nothing'' return type needs to be specified explicitly");
+        MAP.put(IMPLICIT_NOTHING_PROPERTY_TYPE, "Deprecated: ''Nothing'' property type needs to be specified explicitly");
         MAP.put(IMPLICIT_INTERSECTION_TYPE, "Inferred type {0} is an intersection, please specify the required type explicitly", RENDER_TYPE);
         MAP.put(EXPECTED_CONDITION, "Expected condition of type kotlin.Boolean");
 

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

@@ -435,13 +435,7 @@ class DeclarationsChecker(
         checkTypeParameterConstraints(property)
         checkPropertyExposedType(property, propertyDescriptor)
         checkPropertyTypeParametersAreUsedInReceiverType(propertyDescriptor)
-        propertyDescriptor.returnType?.let {
+        checkImplicitCallableType(property, propertyDescriptor)
-            if (property.typeReference == null) {
-                if (it.constructor is IntersectionTypeConstructor) {
-                    trace.report(IMPLICIT_INTERSECTION_TYPE.on(property.nameIdentifier ?: property, it))
-                }
-            }
-        }
     }
 
     private fun checkPropertyTypeParametersAreUsedInReceiverType(descriptor: PropertyDescriptor) {
@@ -656,19 +650,25 @@ class DeclarationsChecker(
         if (!function.hasBody() && !hasAbstractModifier && !hasExternalModifier) {
             trace.report(NON_MEMBER_FUNCTION_NO_BODY.on(function, functionDescriptor))
         }
-        functionDescriptor.returnType?.let {
+        checkImplicitCallableType(function, functionDescriptor)
-            if (!function.hasDeclaredReturnType()) {
+        checkFunctionExposedType(function, functionDescriptor)
+        checkVarargParameters(trace, functionDescriptor)
+    }
+
+    private fun checkImplicitCallableType(declaration: KtCallableDeclaration, descriptor: CallableDescriptor) {
+        descriptor.returnType?.let {
+            if (declaration.typeReference == null) {
+                val target = declaration.nameIdentifier ?: declaration
                 if (it.isNothing()) {
-                    trace.report(IMPLICIT_NOTHING_RETURN_TYPE.on(nameIdentifier ?: function))
+                    trace.report(
+                            (if (declaration is KtProperty) IMPLICIT_NOTHING_PROPERTY_TYPE else IMPLICIT_NOTHING_RETURN_TYPE).on(target)
+                    )
                 }
                 if (it.constructor is IntersectionTypeConstructor) {
-                    trace.report(IMPLICIT_INTERSECTION_TYPE.on(nameIdentifier ?: function, it))
+                    trace.report(IMPLICIT_INTERSECTION_TYPE.on(target, it))
                 }
             }
         }
-
-        checkFunctionExposedType(function, functionDescriptor)
-        checkVarargParameters(trace, functionDescriptor)
     }
 
     private fun checkFunctionExposedType(function: KtFunction, functionDescriptor: FunctionDescriptor) {

compiler/testData/diagnostics/tests/implicitNothing.kt

@@ -5,3 +5,14 @@ fun <!IMPLICIT_NOTHING_RETURN_TYPE!>bar<!>() = null!!
 fun <!IMPLICIT_NOTHING_RETURN_TYPE!>baz<!>() = bar()
 
 fun gav(): Any = null!!
+
+val <!IMPLICIT_NOTHING_PROPERTY_TYPE!>x<!> = null!!
+
+val y: Nothing = throw Exception()
+
+fun check() {
+    // Error: KT-10449
+    fun local() = bar()
+    // Unreachable / unused, but not implicit Nothing
+    <!UNREACHABLE_CODE!>val <!UNUSED_VARIABLE!>x<!> =<!> null!!
+}

compiler/testData/diagnostics/tests/implicitNothing.txt

@@ -1,6 +1,9 @@
 package
 
+public val x: kotlin.Nothing
+public val y: kotlin.Nothing
 public fun bar(): kotlin.Nothing
 public fun baz(): kotlin.Nothing
+public fun check(): kotlin.Unit
 public fun foo(): kotlin.Nothing
 public fun gav(): kotlin.Any

compiler/testData/diagnostics/testsWithStdLib/resolve/javaPackageMembers.kt

@@ -1,6 +1,6 @@
 fun fn(): Nothing = throw java.lang.RuntimeException("oops")
 
-val x = throw java.lang.RuntimeException("oops")
+val x: Nothing = throw java.lang.RuntimeException("oops")
 
 class SomeClass {
     fun method() {