Specificity supported for dynamic types

compiler/frontend/src/org/jetbrains/jet/lang/resolve/OverloadUtil.java

@@ -22,6 +22,7 @@ import org.jetbrains.jet.lang.descriptors.ConstructorDescriptor;
 import org.jetbrains.jet.lang.descriptors.SimpleFunctionDescriptor;
 import org.jetbrains.jet.lang.descriptors.PropertyDescriptor;
 import org.jetbrains.jet.lang.types.JetType;
+import org.jetbrains.jet.lang.types.TypesPackage;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 
 import java.util.List;
@@ -70,8 +71,8 @@ public class OverloadUtil {
         for (int i = 0; i < superValueParameters.size(); ++i) {
             JetType superValueParameterType = OverridingUtil.getUpperBound(superValueParameters.get(i));
             JetType subValueParameterType = OverridingUtil.getUpperBound(subValueParameters.get(i));
-            // TODO: compare erasure
+            if (!JetTypeChecker.DEFAULT.equalTypes(superValueParameterType, subValueParameterType)
-            if (!JetTypeChecker.DEFAULT.equalTypes(superValueParameterType, subValueParameterType)) {
+                || TypesPackage.oneMoreSpecificThanAnother(subValueParameterType, superValueParameterType)) {
                 return OverridingUtil.OverrideCompatibilityInfo
                         .valueParameterTypeMismatch(superValueParameterType, subValueParameterType, INCOMPATIBLE);
             }

compiler/testData/diagnostics/tests/dynamicTypes/overloading.kt

@@ -0,0 +1,26 @@
+// !CHECK_TYPE
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+// MODULE[js]: m1
+// FILE: k.kt
+
+fun dyn(d: dynamic) {}
+
+fun foo(d: dynamic): String = ""
+fun foo(d: Int): Int = 1
+
+fun nothing(d: dynamic): Int = 1
+fun nothing(d: Nothing): String = ""
+
+fun test(d: dynamic) {
+    dyn(1)
+    dyn("")
+
+    foo(1).checkType { it : _<Int> }
+    foo("").checkType { it : _<String> }
+
+    // Checking specificity of `dynamic` vs `Nothing`
+    nothing(d).checkType { it : _<String> }
+    nothing("").checkType { it : _<Int> }
+    [suppress("UNREACHABLE_CODE")] nothing(null!!).checkType { it : _<String> }
+}

compiler/testData/diagnostics/tests/dynamicTypes/overloading.txt

@@ -0,0 +1,8 @@
+package
+
+internal fun dyn(/*0*/ d: (kotlin.Nothing..kotlin.Any?)): kotlin.Unit
+internal fun foo(/*0*/ d: (kotlin.Nothing..kotlin.Any?)): kotlin.String
+internal fun foo(/*0*/ d: kotlin.Int): kotlin.Int
+internal fun nothing(/*0*/ d: dynamic): kotlin.Int
+internal fun nothing(/*0*/ d: kotlin.Nothing): kotlin.String
+internal fun test(/*0*/ d: dynamic): kotlin.Unit

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -3722,6 +3722,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("overloading.kt")
+            public void testOverloading() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/dynamicTypes/overloading.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("unsupported.kt")
             public void testUnsupported() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/dynamicTypes/unsupported.kt");

core/descriptors/src/org/jetbrains/jet/lang/types/TypeCapabilities.kt

@@ -33,6 +33,8 @@ public trait Specificity : TypeCapability {
 
 fun JetType.getSpecificityRelationTo(otherType: JetType) = this.getCapability(javaClass<Specificity>())?.getSpecificityRelationTo(otherType) ?: Specificity.Relation.DONT_KNOW
 
+fun oneMoreSpecificThanAnother(a: JetType, b: JetType) = a.getSpecificityRelationTo(b) != Specificity.Relation.DONT_KNOW || b.getSpecificityRelationTo(a) != Specificity.Relation.DONT_KNOW
+
 // To facilitate laziness, any JetType implementation may inherit from this trait,
 // even if it turns out that the type an instance represents is not actually a type variable
 // (i.e. it is not derived from a type parameter), see isTypeVariable

core/descriptors/src/org/jetbrains/jet/lang/types/dynamicTypes.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.lang.types
 
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
+import kotlin.platform.platformStatic
 
 open class DynamicTypesSettings {
     open val dynamicTypesAllowed: Boolean
@@ -28,10 +29,36 @@ class DynamicTypesAllowed: DynamicTypesSettings() {
         get() = true
 }
 
+trait Dynamicity : TypeCapability
+
 object DynamicType : DelegatingFlexibleType(
         KotlinBuiltIns.getInstance().getNothingType(),
         KotlinBuiltIns.getInstance().getNullableAnyType(),
-        FlexibleTypeCapabilities.NONE
+        DynamicTypeCapabilities
 ) {
     override fun getDelegate() = upperBound
-}
+}
+
+fun JetType.isDynamic(): Boolean = this.getCapability(javaClass<Dynamicity>()) != null
+
+public object DynamicTypeCapabilities : FlexibleTypeCapabilities {
+    override val id: String get() = "kotlin.DynamicType"
+
+    override fun <T : TypeCapability> getCapability(capabilityClass: Class<T>, jetType: JetType, flexibility: Flexibility): T? {
+        if (capabilityClass.isAssignableFrom(javaClass<Impl>()))
+            [suppress("UNCHECKED_CAST")]
+            return Impl(jetType, flexibility) as T
+        else return null
+    }
+
+
+    private class Impl(val type: JetType, val flexibility: Flexibility) : Dynamicity, Specificity {
+
+        private val lowerBound: JetType get() = flexibility.lowerBound
+        private val upperBound: JetType get() = flexibility.upperBound
+
+        override fun getSpecificityRelationTo(otherType: JetType): Specificity.Relation {
+            return if (!otherType.isDynamic()) Specificity.Relation.LESS_SPECIFIC else Specificity.Relation.DONT_KNOW
+        }
+    }
+}

spec-docs/dynamic-types.md

@@ -32,6 +32,7 @@ fun jsFun(p: dynamic): dynamic
 - ??? `glb(T, dynamic) = T`
 - `dynamic` can't be substituted for reified parameters of function/constructor calls (this means that it's not possible to create an array of `dynamic`)
 - `dynamic` can't be used as a supertype or upper bound for a tpe parameter
+- `dynamic` is less specific than any other type
 
 ## Syntax