Implement operator checks for controller's handleResult

compiler/frontend/src/org/jetbrains/kotlin/coroutines/coroutineUtil.kt

@@ -17,25 +17,14 @@
 package org.jetbrains.kotlin.coroutines
 
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
-import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.types.KotlinType
-
+import org.jetbrains.kotlin.util.OperatorNameConventions
-@JvmField
-val CONTINUATION_INTERFACE_FQ_NAME = FqName("kotlin.coroutines.Continuation")
-
-@JvmField
-val HANDLE_RESULT_NAME = Name.identifier("handleResult")
 
 /**
- * @returns type of first value parameter if function is 'operator handleResult' in coroutine controller
+ * @returns type of first value parameter if function is 'operator handleResult' in coroutines controller
  */
 fun SimpleFunctionDescriptor.getExpectedTypeForCoroutineControllerHandleResult(): KotlinType? {
-    if (name != HANDLE_RESULT_NAME) return null
+    if (!isOperator || name != OperatorNameConventions.COROUTINE_HANDLE_RESULT) return null
-    if (valueParameters.size != 2) return null
 
-    if (valueParameters[1].type.constructor.declarationDescriptor?.fqNameUnsafe != CONTINUATION_INTERFACE_FQ_NAME.toUnsafe()) return null
+    return valueParameters.getOrNull(0)?.type
-
-    return valueParameters[0].type
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/CallResolverUtil.kt

@@ -179,7 +179,9 @@ fun getEffectiveExpectedType(parameterDescriptor: ValueParameterDescriptor, argu
 
         val newExpectedLambdaReturnType =
                 receiverType.memberScope
-                        .getContributedFunctions(HANDLE_RESULT_NAME, KotlinLookupLocation(argument.asElement())).mapNotNull {
+                        .getContributedFunctions(
+                                OperatorNameConventions.COROUTINE_HANDLE_RESULT, KotlinLookupLocation(argument.asElement())
+                        ).mapNotNull {
                                 it.getExpectedTypeForCoroutineControllerHandleResult()
                         }.singleOrNull()
                 // If no handleResult function found, then expected return type for lambda is Unit

compiler/testData/diagnostics/tests/coroutines/lambdaExpectedType.kt

@@ -1,15 +1,15 @@
 // !CHECK_TYPE
 // !DIAGNOSTICS: -UNUSED_PARAMETER -ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE -UNUSED_VALUE -UNUSED_VARIABLE
 class IntController {
-    fun handleResult(x: Int, c: Continuation<Nothing>) { }
+    operator fun handleResult(x: Int, c: Continuation<Nothing>) { }
 }
 
 class GenericController<T> {
-    fun handleResult(x: T, c: Continuation<Nothing>) { }
+    operator fun handleResult(x: T, c: Continuation<Nothing>) { }
 }
 
 class UnitController {
-    fun handleResult(x: Unit, c: Continuation<Nothing>) { }
+    operator fun handleResult(x: Unit, c: Continuation<Nothing>) { }
 }
 
 class EmptyController

compiler/testData/diagnostics/tests/coroutines/lambdaExpectedType.txt

@@ -18,7 +18,7 @@ public final class EmptyController {
 public final class GenericController</*0*/ T> {
     public constructor GenericController</*0*/ T>()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public final fun handleResult(/*0*/ x: T, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public final operator fun handleResult(/*0*/ x: T, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
@@ -26,7 +26,7 @@ public final class GenericController</*0*/ T> {
 public final class IntController {
     public constructor IntController()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public final fun handleResult(/*0*/ x: kotlin.Int, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public final operator fun handleResult(/*0*/ x: kotlin.Int, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
@@ -34,7 +34,7 @@ public final class IntController {
 public final class UnitController {
     public constructor UnitController()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public final fun handleResult(/*0*/ x: kotlin.Unit, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public final operator fun handleResult(/*0*/ x: kotlin.Unit, /*1*/ c: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

compiler/testData/diagnostics/tests/coroutines/wrongHandleResult.kt

@@ -0,0 +1,34 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+class A1 {
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Int) {
+    }
+}
+
+class A2 {
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Int, y: Int) {
+    }
+}
+
+class A3 {
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Int, y: Continuation<Any>) {
+    }
+}
+
+class A4 {
+    operator fun handleResult(x: Int, y: Continuation<Nothing>) {
+    }
+}
+
+class A5 {
+    // TODO: Allow?
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Int, y: Continuation<Nothing>): Int = 1
+}
+
+class A6 {
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun <T> handleResult(x: Int, y: Continuation<Nothing>) {
+    }
+
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: String = "", y: Continuation<Nothing>) {}
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Double = 1.0, vararg y: Continuation<Nothing>) {}
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun handleResult(x: Double = 1.0, z: Int, y: Continuation<Nothing>) {}
+}

compiler/testData/diagnostics/tests/coroutines/wrongHandleResult.txt

@@ -0,0 +1,52 @@
+package
+
+public final class A1 {
+    public constructor A1()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A2 {
+    public constructor A2()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A3 {
+    public constructor A3()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.coroutines.Continuation<kotlin.Any>): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A4 {
+    public constructor A4()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A5 {
+    public constructor A5()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A6 {
+    public constructor A6()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun handleResult(/*0*/ x: kotlin.Double = ..., /*1*/ vararg y: kotlin.coroutines.Continuation<kotlin.Nothing> /*kotlin.Array<out kotlin.coroutines.Continuation<kotlin.Nothing>>*/): kotlin.Unit
+    public final operator fun handleResult(/*0*/ x: kotlin.Double = ..., /*1*/ z: kotlin.Int, /*2*/ y: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public final operator fun </*0*/ T> handleResult(/*0*/ x: kotlin.Int, /*1*/ y: kotlin.coroutines.Continuation<kotlin.Nothing>): kotlin.Unit
+    public final operator fun handleResult(/*0*/ x: kotlin.String = ..., /*1*/ y: kotlin.coroutines.Continuation<kotlin.Nothing>): 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/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -3878,6 +3878,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/coroutines/lambdaExpectedType.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("wrongHandleResult.kt")
+            public void testWrongHandleResult() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/coroutines/wrongHandleResult.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/diagnostics/tests/cyclicHierarchy")

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

@@ -51,6 +51,7 @@ public class DescriptorUtils {
     public static final FqName JVM_NAME = new FqName("kotlin.jvm.JvmName");
     public static final FqName VOLATILE = new FqName("kotlin.jvm.Volatile");
     public static final FqName SYNCHRONIZED = new FqName("kotlin.jvm.Synchronized");
+    public static final FqName CONTINUATION_INTERFACE_FQ_NAME = new FqName("kotlin.coroutines.Continuation");
 
     private DescriptorUtils() {
     }

core/descriptors/src/org/jetbrains/kotlin/util/OperatorChecker.kt

@@ -22,23 +22,20 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
+import org.jetbrains.kotlin.resolve.DescriptorUtils
-import org.jetbrains.kotlin.resolve.descriptorUtil.hasDefaultValue
+import org.jetbrains.kotlin.resolve.descriptorUtil.*
-import org.jetbrains.kotlin.resolve.descriptorUtil.isExtension
-import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.isNothing
 import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
 import org.jetbrains.kotlin.util.MemberKindCheck.Member
 import org.jetbrains.kotlin.util.MemberKindCheck.MemberOrExtension
-import org.jetbrains.kotlin.util.ReturnsCheck.*
-import org.jetbrains.kotlin.util.ValueParameterCountCheck.NoValueParameters
-import org.jetbrains.kotlin.util.ValueParameterCountCheck.SingleValueParameter
 import org.jetbrains.kotlin.util.OperatorNameConventions.ASSIGNMENT_OPERATIONS
 import org.jetbrains.kotlin.util.OperatorNameConventions.BINARY_OPERATION_NAMES
 import org.jetbrains.kotlin.util.OperatorNameConventions.COMPARE_TO
 import org.jetbrains.kotlin.util.OperatorNameConventions.COMPONENT_REGEX
 import org.jetbrains.kotlin.util.OperatorNameConventions.CONTAINS
+import org.jetbrains.kotlin.util.OperatorNameConventions.COROUTINE_HANDLE_RESULT
 import org.jetbrains.kotlin.util.OperatorNameConventions.DEC
 import org.jetbrains.kotlin.util.OperatorNameConventions.EQUALS
 import org.jetbrains.kotlin.util.OperatorNameConventions.GET
@@ -52,6 +49,9 @@ import org.jetbrains.kotlin.util.OperatorNameConventions.RANGE_TO
 import org.jetbrains.kotlin.util.OperatorNameConventions.SET
 import org.jetbrains.kotlin.util.OperatorNameConventions.SET_VALUE
 import org.jetbrains.kotlin.util.OperatorNameConventions.SIMPLE_UNARY_OPERATION_NAMES
+import org.jetbrains.kotlin.util.ReturnsCheck.*
+import org.jetbrains.kotlin.util.ValueParameterCountCheck.NoValueParameters
+import org.jetbrains.kotlin.util.ValueParameterCountCheck.SingleValueParameter
 
 sealed class CheckResult(val isSuccess: Boolean) {
     class IllegalSignature(val error: String) : CheckResult(false)
@@ -85,6 +85,9 @@ sealed class ValueParameterCountCheck(override val description: String) : Check
     class AtLeast(val n: Int) : ValueParameterCountCheck("must have at least $n value parameter" + (if (n > 1) "s" else "")) {
         override fun check(functionDescriptor: FunctionDescriptor) = functionDescriptor.valueParameters.size >= n
     }
+    class Equals(val n: Int) : ValueParameterCountCheck("must have exactly $n value parameters") {
+        override fun check(functionDescriptor: FunctionDescriptor) = functionDescriptor.valueParameters.size == n
+    }
 }
 
 private object NoDefaultAndVarargsCheck : Check {
@@ -93,6 +96,11 @@ private object NoDefaultAndVarargsCheck : Check {
             functionDescriptor.valueParameters.all { !it.hasDefaultValue() && it.varargElementType == null }
 }
 
+private object NoTypeParametersCheck : Check {
+    override val description = "should not have type parameters"
+    override fun check(functionDescriptor: FunctionDescriptor) = functionDescriptor.typeParameters.isEmpty()
+}
+
 private object IsKPropertyCheck : Check {
     override val description = "second parameter must have a KProperty type or its supertype"
     override fun check(functionDescriptor: FunctionDescriptor): Boolean {
@@ -179,7 +187,18 @@ object OperatorChecks {
                 }
             },
             Checks(ASSIGNMENT_OPERATIONS, MemberOrExtension, ReturnsUnit, SingleValueParameter, NoDefaultAndVarargsCheck),
-            Checks(COMPONENT_REGEX, MemberOrExtension, NoValueParameters)
+            Checks(COMPONENT_REGEX, MemberOrExtension, NoValueParameters),
+            Checks(
+                    COROUTINE_HANDLE_RESULT, Member, ValueParameterCountCheck.Equals(2), ReturnsUnit,
+                    NoDefaultAndVarargsCheck, NoTypeParametersCheck) {
+                val secondParameter = valueParameters[1]
+                ensure(
+                        secondParameter.type.constructor.declarationDescriptor?.fqNameUnsafe == DescriptorUtils.CONTINUATION_INTERFACE_FQ_NAME.toUnsafe()
+                            && secondParameter.type.arguments[0].type.isNothing()
+                ) {
+                    "Second parameter should be Continuation<Nothing>"
+                }
+            }
     )
 
     fun checkOperator(functionDescriptor: FunctionDescriptor): CheckResult {
@@ -192,4 +211,4 @@ object OperatorChecks {
     }
 }
 
-fun FunctionDescriptor.isValidOperator() = isOperator && OperatorChecks.checkOperator(this).isSuccess
+fun FunctionDescriptor.isValidOperator() = isOperator && OperatorChecks.checkOperator(this).isSuccess

core/descriptors/src/org/jetbrains/kotlin/util/OperatorNameConventions.kt

@@ -56,6 +56,7 @@ object OperatorNameConventions {
     @JvmField val MOD_ASSIGN = Name.identifier("modAssign")
     @JvmField val PLUS_ASSIGN = Name.identifier("plusAssign")
     @JvmField val MINUS_ASSIGN = Name.identifier("minusAssign")
+    @JvmField val COROUTINE_HANDLE_RESULT = Name.identifier("handleResult")
 
     // If you add new unary, binary or assignment operators, add it to OperatorConventions as well