Move OverridingUtil#getUpperBound to OverloadUtil, add tests on overloads

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

@@ -21,8 +21,9 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.FqNameUnsafe
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo.Result.*
+import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo.Result.INCOMPATIBLE
 import org.jetbrains.kotlin.resolve.scopes.KtScope
+import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.oneMoreSpecificThanAnother
 
@@ -47,11 +48,12 @@ object OverloadUtil {
         val aValueParameters = OverridingUtil.compiledValueParameters(a)
         val bValueParameters = OverridingUtil.compiledValueParameters(b)
 
-        for (i in aValueParameters.indices) {
-            val superValueParameterType = OverridingUtil.getUpperBound(aValueParameters[i])
-            val subValueParameterType = OverridingUtil.getUpperBound(bValueParameters[i])
+        for ((aType, bType) in aValueParameters.zip(bValueParameters)) {
+            // TODO: check type parameters, create a substitution and compare parameter types according to it, like in OverridingUtil
+            val superValueParameterType = aType.upperBound
+            val subValueParameterType = bType.upperBound
             if (!KotlinTypeChecker.DEFAULT.equalTypes(superValueParameterType, subValueParameterType) ||
-                    oneMoreSpecificThanAnother(subValueParameterType, superValueParameterType)) {
+                oneMoreSpecificThanAnother(subValueParameterType, superValueParameterType)) {
                 return true
             }
         }
@@ -67,6 +69,16 @@ object OverloadUtil {
                 else -> throw IllegalStateException()
             }
 
+    private val KotlinType.upperBound: KotlinType
+        get() {
+            val classifier = constructor.declarationDescriptor
+            return when (classifier) {
+                is ClassDescriptor -> this
+                is TypeParameterDescriptor -> classifier.upperBoundsAsType
+                else -> error("Unknown type constructor: $this")
+            }
+        }
+
     public @JvmStatic fun groupModulePackageMembersByFqName(
             c: BodiesResolveContext,
             constructorsInPackages: MultiMap<FqNameUnsafe, ConstructorDescriptor>

compiler/testData/diagnostics/tests/overload/TypeParameterMultipleBounds.kt

@@ -0,0 +1,15 @@
+import java.io.Serializable
+
+interface Test1 {
+    <!CONFLICTING_OVERLOADS!>fun <T> foo(t: T)<!> where T : Cloneable, T : Serializable
+    <!CONFLICTING_OVERLOADS!>fun <T> foo(t: T)<!> where T : Serializable, T : Cloneable
+}
+
+
+interface I1
+interface I2 : I1
+
+interface Test2 {
+    <!CONFLICTING_OVERLOADS!>fun <T> foo(t: T)<!> where T : I1, T : I2
+    <!CONFLICTING_OVERLOADS!>fun <T> foo(t: T)<!> where T : I2, T : I1
+}

compiler/testData/diagnostics/tests/overload/TypeParameterMultipleBounds.txt

@@ -0,0 +1,29 @@
+package
+
+public interface I1 {
+    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*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface I2 : I1 {
+    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*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface Test1 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun </*0*/ T : kotlin.Cloneable> foo(/*0*/ t: T): kotlin.Unit where T : java.io.Serializable
+    public abstract fun </*0*/ T : java.io.Serializable> foo(/*0*/ t: T): kotlin.Unit where T : kotlin.Cloneable
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface Test2 {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun </*0*/ T : I1> foo(/*0*/ t: T): kotlin.Unit where T : I2
+    public abstract fun </*0*/ T : I2> foo(/*0*/ t: T): kotlin.Unit where T : I1
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/redeclarations/typeParameterWithTwoBounds.kt

@@ -0,0 +1,8 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+interface Foo
+interface Bar
+
+<!CONFLICTING_JVM_DECLARATIONS!>fun <T> foo(x: T): T<!> where T: Foo, T: Bar {null!!}
+<!CONFLICTING_JVM_DECLARATIONS!>fun foo(x: Foo): Foo<!> {null!!}
+fun foo(x: Bar): Bar {null!!}

compiler/testData/diagnostics/tests/redeclarations/typeParameterWithTwoBounds.txt

@@ -0,0 +1,17 @@
+package
+
+public fun foo(/*0*/ x: Bar): Bar
+public fun foo(/*0*/ x: Foo): Foo
+public fun </*0*/ T : Foo> foo(/*0*/ x: T): T where T : Bar
+
+public interface Bar {
+    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*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface Foo {
+    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*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -10697,6 +10697,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/overload/SyntheticAndNotSynthetic.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("TypeParameterMultipleBounds.kt")
+            public void testTypeParameterMultipleBounds() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/overload/TypeParameterMultipleBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/diagnostics/tests/override")
@@ -12017,6 +12023,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/redeclarations/SingletonAndFunctionSameName.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("typeParameterWithTwoBounds.kt")
+            public void testTypeParameterWithTwoBounds() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/redeclarations/typeParameterWithTwoBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/diagnostics/tests/reflection")

core/descriptors/src/org/jetbrains/kotlin/resolve/OverridingUtil.java

@@ -237,18 +237,6 @@ public class OverridingUtil {
         return parameters;
     }
 
-    static KotlinType getUpperBound(KotlinType type) {
-        if (type.getConstructor().getDeclarationDescriptor() instanceof ClassDescriptor) {
-            return type;
-        }
-        else if (type.getConstructor().getDeclarationDescriptor() instanceof TypeParameterDescriptor) {
-            return ((TypeParameterDescriptor) type.getConstructor().getDeclarationDescriptor()).getUpperBoundsAsType();
-        }
-        else {
-            throw new IllegalStateException("unknown type constructor: " + type.getConstructor().getClass().getName());
-        }
-    }
-
     public static void generateOverridesInFunctionGroup(
             @SuppressWarnings("UnusedParameters")
             @NotNull Name name, //DO NOT DELETE THIS PARAMETER: needed to make sure all descriptors have the same name