Do not write version requirements for suspend functions

Previous attempt was at 6807ed6642, but it was reverted in 7771e5914d
(see that commit for the explanation). Now it should be fine to remove
these version requirements.

No issue reported because it's mostly not a user-visible change. The
main effect is that it reduces differences in metadata between K1 and
K2, namely it fixes the ValueClass.kt kotlinp test.

compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt

@@ -478,10 +478,6 @@ class FirElementSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(property))
 
-            if (property.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -573,10 +569,6 @@ class FirElementSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(function))
 
-            if (function.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -679,10 +671,6 @@ class FirElementSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(constructor))
 
-            if (constructor.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -1062,11 +1050,6 @@ class FirElementSerializer private constructor(
 
     private fun useTypeTable(): Boolean = extension.shouldUseTypeTable()
 
-    private fun FirCallableDeclaration.isSuspendOrHasSuspendTypesInSignature(): Boolean {
-        // TODO (types in signature)
-        return this.isSuspend
-    }
-
     private fun MutableVersionRequirementTable.serializeVersionRequirements(container: FirAnnotationContainer): List<Int> =
         serializeVersionRequirements(container.annotations)
 
@@ -1082,9 +1065,6 @@ class FirElementSerializer private constructor(
         return writeLanguageVersionRequirement(languageFeature, this)
     }
 
-    private fun MutableVersionRequirementTable.writeVersionRequirementDependingOnCoroutinesVersion(): Int =
-        writeVersionRequirement(LanguageFeature.ReleaseCoroutines)
-
     private fun serializeVersionRequirementFromRequireKotlin(annotation: FirAnnotation): ProtoBuf.VersionRequirement.Builder? {
         val argumentMapping = annotation.argumentMapping.mapping
 
@@ -1240,7 +1220,7 @@ class FirElementSerializer private constructor(
             return serializer
         }
 
-        fun writeLanguageVersionRequirement(
+        private fun writeLanguageVersionRequirement(
             languageFeature: LanguageFeature,
             versionRequirementTable: MutableVersionRequirementTable
         ): Int {
@@ -1252,7 +1232,7 @@ class FirElementSerializer private constructor(
             )
         }
 
-        fun writeVersionRequirement(
+        private fun writeVersionRequirement(
             major: Int,
             minor: Int,
             patch: Int,

compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt

@@ -8,7 +8,6 @@ package org.jetbrains.kotlin.serialization
 import com.intellij.openapi.project.Project
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.isSuspendFunctionType
-import org.jetbrains.kotlin.builtins.isSuspendFunctionTypeOrSubtype
 import org.jetbrains.kotlin.builtins.transformSuspendFunctionToRuntimeFunctionType
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
@@ -43,7 +42,6 @@ import org.jetbrains.kotlin.serialization.deserialization.descriptorVisibility
 import org.jetbrains.kotlin.serialization.deserialization.memberKind
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.extensions.TypeAttributeTranslators
-import org.jetbrains.kotlin.types.typeUtil.contains
 import org.jetbrains.kotlin.types.typeUtil.replaceAnnotations
 import java.util.*
 
@@ -296,10 +294,6 @@ class DescriptorSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(descriptor))
 
-            if (descriptor.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -389,10 +383,6 @@ class DescriptorSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(descriptor))
 
-            if (descriptor.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -421,10 +411,6 @@ class DescriptorSerializer private constructor(
         versionRequirementTable?.run {
             builder.addAllVersionRequirement(serializeVersionRequirements(descriptor))
 
-            if (descriptor.isSuspendOrHasSuspendTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -437,24 +423,6 @@ class DescriptorSerializer private constructor(
         return builder
     }
 
-    private fun MutableVersionRequirementTable.writeVersionRequirementDependingOnCoroutinesVersion(): Int =
-        writeVersionRequirement(LanguageFeature.ReleaseCoroutines)
-
-    private fun CallableMemberDescriptor.isSuspendOrHasSuspendTypesInSignature(): Boolean {
-        if (this is FunctionDescriptor && isSuspend) return true
-
-        return allTypesFromSignature().any { type -> type.contains(UnwrappedType::isSuspendFunctionTypeOrSubtype) }
-    }
-
-    private fun CallableMemberDescriptor.allTypesFromSignature(): List<KotlinType> {
-        return listOfNotNull(
-            extensionReceiverParameter?.type,
-            returnType,
-            *typeParameters.flatMap { it.upperBounds }.toTypedArray(),
-            *valueParameters.map(ValueParameterDescriptor::getType).toTypedArray()
-        )
-    }
-
     private fun typeAliasProto(descriptor: TypeAliasDescriptor): ProtoBuf.TypeAlias.Builder? {
         val builder = ProtoBuf.TypeAlias.newBuilder()
         val local = createChildSerializer(descriptor)

compiler/testData/versionRequirement/nestedClassMembers.kt

@@ -12,8 +12,6 @@ class Outer {
 
             @RequireKotlin("1.3")
             val x = ""
-
-            suspend fun s() {}
         }
     }
 

compiler/testData/versionRequirement/suspendFun.kt

@@ -1,16 +0,0 @@
-package test
-
-suspend fun topLevel() {}
-
-class Foo {
-    constructor(block: suspend () -> Unit)
-
-    suspend fun member() {}
-}
-
-fun async1(block: suspend () -> Unit) {}
-fun (suspend () -> Unit).async2() {}
-fun async3(): suspend () -> Unit = null!!
-fun async4(): Map<Int, suspend () -> Unit>? = null
-
-val (suspend () -> Unit).asyncVal: () -> Unit get() = {}

compiler/tests/org/jetbrains/kotlin/serialization/AbstractVersionRequirementTest.kt

@@ -124,23 +124,6 @@ abstract class AbstractVersionRequirementTest : TestCaseWithTmpdir() {
 
     protected abstract fun loadModule(directory: File): ModuleDescriptor
 
-    fun testSuspendFun() {
-        doTest(
-            VersionRequirement.Version(1, 3), DeprecationLevel.ERROR, null, ProtoBuf.VersionRequirement.VersionKind.LANGUAGE_VERSION, null,
-            customLanguageVersion = LanguageVersion.KOTLIN_1_3,
-            fqNamesWithRequirements = listOf(
-                "test.topLevel",
-                "test.Foo.member",
-                "test.Foo.<init>",
-                "test.async1",
-                "test.async2",
-                "test.async3",
-                "test.async4",
-                "test.asyncVal"
-            )
-        )
-    }
-
     fun testDefinitelyNotNull() {
         doTest(
             VersionRequirement.Version(1, 7), DeprecationLevel.ERROR, null, ProtoBuf.VersionRequirement.VersionKind.LANGUAGE_VERSION, null,
@@ -221,7 +204,6 @@ abstract class AbstractVersionRequirementTest : TestCaseWithTmpdir() {
                 "test.Outer.Inner.Deep.<init>",
                 "test.Outer.Inner.Deep.f",
                 "test.Outer.Inner.Deep.x",
-                "test.Outer.Inner.Deep.s",
                 "test.Outer.Nested.g",
                 "test.Outer.Companion"
             )