Extensible specificity expressed as a type capability

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/results/OverloadingConflictResolver.java

@@ -25,9 +25,7 @@ import org.jetbrains.jet.lang.resolve.OverrideResolver;
 import org.jetbrains.jet.lang.resolve.calls.model.MutableResolvedCall;
 import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCall;
 import org.jetbrains.jet.lang.resolve.calls.model.VariableAsFunctionResolvedCall;
-import org.jetbrains.jet.lang.types.BoundsSubstitutor;
-import org.jetbrains.jet.lang.types.JetType;
-import org.jetbrains.jet.lang.types.TypeUtils;
+import org.jetbrains.jet.lang.types.*;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
@@ -240,21 +238,15 @@ public class OverloadingConflictResolver {
 
     private boolean typeMoreSpecific(@NotNull JetType specific, @NotNull JetType general) {
         boolean isSubtype = JetTypeChecker.DEFAULT.isSubtypeOf(specific, general) ||
-                            numericTypeMoreSpecific(specific, general);
+                    numericTypeMoreSpecific(specific, general);
+
         if (!isSubtype) return false;
 
-        boolean specificIsFlexible = specific.isFlexible();
-        boolean generalIsFlexible = general.isFlexible();
-
-        if (specificIsFlexible && !generalIsFlexible) {
-            // Int! lessSpecific Int
-            // Int! >< Int?
+        Specificity.Relation sThanG = TypesPackage.getSpecificityRelationTo(specific, general);
+        Specificity.Relation gThanS = TypesPackage.getSpecificityRelationTo(general, specific);
+        if (sThanG == Specificity.Relation.LESS_SPECIFIC && gThanS != Specificity.Relation.LESS_SPECIFIC) {
             return false;
         }
-        else if (!specificIsFlexible && generalIsFlexible) {
-            // Int? >< Int!
-            if (specific.isNullable()) return false;
-        }
 
         return true;
     }

compiler/testData/diagnostics/tests/platformTypes/intVsIntegerAmbiguity.kt

@@ -9,6 +9,8 @@ public class J {
 
     public interface B {}
     public static B foo(Integer s);
+
+    public static Integer getInteger();
 }
 
 // FILE: k.kt
@@ -25,5 +27,8 @@ fun test(i: Int, ni: Int?) {
     foo(i) : J.A
     J.foo(ni) : J.B
     <!OVERLOAD_RESOLUTION_AMBIGUITY!>foo<!>(ni)
+
+    foo(J.getInteger())
+    J.foo(J.getInteger())
 }
 

compiler/testData/diagnostics/tests/platformTypes/methodCall/overloadingForSubclass.kt

@@ -0,0 +1,30 @@
+// FILE: p/Super.java
+package p;
+
+public interface Super {}
+
+// FILE: p/Sub.java
+package p;
+
+public interface Sub extends Super {}
+
+// FILE: p/Util.java
+
+package p;
+
+public abstract class Util {
+    public abstract void foo(String s, Super sup)
+    public void foo(String s, Sub sub) {}
+}
+
+// FILE: k.kt
+
+import p.*
+
+class C: Util() {
+    override fun foo(s: String, sub: Super) {}
+}
+
+fun foo(sub: Sub) {
+    C().foo("", sub)
+}

compiler/testData/diagnostics/tests/platformTypes/methodCall/overloadingForSubclass.txt

@@ -0,0 +1,12 @@
+package
+
+internal fun foo(/*0*/ sub: p.Sub): kotlin.Unit
+
+internal final class C : p.Util {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun foo(/*0*/ s: kotlin.String, /*1*/ sub: p.Super): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun foo(/*0*/ s: kotlin.String!, /*1*/ sub: p.Sub!): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -7863,6 +7863,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     doTest(fileName);
                 }
                 
+                @TestMetadata("overloadingForSubclass.kt")
+                public void testOverloadingForSubclass() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/platformTypes/methodCall/overloadingForSubclass.kt");
+                    doTest(fileName);
+                }
+                
                 @TestMetadata("sam.kt")
                 public void testSam() throws Exception {
                     String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/platformTypes/methodCall/sam.kt");

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/types/LazyJavaTypeResolver.kt

@@ -34,8 +34,6 @@ import org.jetbrains.jet.lang.types.checker.JetTypeChecker
 import org.jetbrains.jet.lang.resolve.java.PLATFORM_TYPES
 import org.jetbrains.jet.lang.resolve.java.lazy.types.Flexibility.*
 import org.jetbrains.jet.lang.descriptors.annotations.Annotations
-import org.jetbrains.jet.lang.resolve.name.FqName
-import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.jet.lang.resolve.java.JvmAnnotationNames
 
 class LazyJavaTypeResolver(
@@ -273,7 +271,7 @@ class LazyJavaTypeResolver(
     public open class FlexibleJavaClassifierType protected (
             lowerBound: JetType,
             upperBound: JetType
-    ) : DelegatingFlexibleType(lowerBound, upperBound), CustomTypeVariable {
+    ) : DelegatingFlexibleType(lowerBound, upperBound), CustomTypeVariable, Specificity {
         public class object {
             public fun create(lowerBound: JetType, upperBound: JetType): JetType {
                 if (lowerBound == upperBound) return lowerBound
@@ -294,6 +292,22 @@ class LazyJavaTypeResolver(
             return if (replacement.isFlexible()) replacement
                    else FlexibleJavaClassifierType(TypeUtils.makeNotNullable(replacement), TypeUtils.makeNullable(replacement))
         }
+
+        override fun getSpecificityRelationTo(otherType: JetType): Specificity.Relation {
+            // For primitive types we have to take care of the case when there are two overloaded methods like
+            //    foo(int) and foo(Integer)
+            // if we do not discriminate one of them, any call to foo(kotlin.Int) will result in overload resolution ambiguity
+            // so, for such cases, we discriminate Integer in favour of int
+            if (!KotlinBuiltIns.getInstance().isPrimitiveType(otherType) || !KotlinBuiltIns.getInstance().isPrimitiveType(getLowerBound())) {
+                return Specificity.Relation.DONT_KNOW
+            }
+            // Int! >< Int?
+            if (otherType.isFlexible()) return Specificity.Relation.DONT_KNOW
+            // Int? >< Int!
+            if (otherType.isNullable()) return Specificity.Relation.DONT_KNOW
+            // Int! lessSpecific Int
+            return Specificity.Relation.LESS_SPECIFIC
+        }
     }
 
     /*

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

@@ -16,6 +16,17 @@
 
 package org.jetbrains.jet.lang.types
 
-import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor
+public trait TypeCapability
 
-public trait TypeCapability
+public trait Specificity : TypeCapability {
+
+    public enum class Relation {
+        LESS_SPECIFIC
+        MORE_SPECIFIC
+        DONT_KNOW
+    }
+
+    public fun getSpecificityRelationTo(otherType: JetType): Relation
+}
+
+fun JetType.getSpecificityRelationTo(otherType: JetType) = this.getCapability(javaClass<Specificity>())?.getSpecificityRelationTo(otherType) ?: Specificity.Relation.DONT_KNOW