Remove configurations and code for Kotlin versions prior to 2.0

Author: Mr3zee

README.md

@@ -157,11 +157,8 @@ Integrations in progress:
 - Integration with [gRPC](https://grpc.io/)  (in prototype)
 
 ## Kotlin compatibility
-We support all stable Kotlin versions starting from 1.7.0:
-- 1.7.0, 1.7.10, 1.7.20, 1.7.21, 1.7.22
-- 1.8.0, 1.8.10, 1.8.20, 1.8.21, 1.8.22
-- 1.9.0, 1.9.10, 1.9.20, 1.9.21, 1.9.22, 1.9.23, 1.9.24, 1.9.25
-- 2.0.0, 2.0.10
+We support all stable Kotlin versions starting from 2.0.0:
+- 2.0.0, 2.0.10, 2.0.20, 2.0.21
 
 To simplify project configuration, our Gradle plugin sets a proper library version automatically using BOM, 
 based on the project's Kotlin version:

build.gradle.kts

@@ -11,12 +11,7 @@ plugins {
     alias(libs.plugins.conventions.kover)
     alias(libs.plugins.conventions.gradle.doctor)
     alias(libs.plugins.binary.compatibility.validator)
-
-    if (libs.versions.atomicfu.get() >= "0.24.0") {
-        alias(libs.plugins.atomicfu.new)
-    } else {
-        alias(libs.plugins.atomicfu.old)
-    }
+    alias(libs.plugins.atomicfu)
 }
 
 // useful for dependencies introspection

compiler-plugin/compiler-plugin-backend/src/main/core/kotlinx/rpc/codegen/extension/RPCDeclarationScanner.kt

@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.util.dumpKotlinLike
-import org.jetbrains.kotlin.ir.util.packageFqName
 
 /**
  * This class scans user declared RPC service
@@ -73,15 +72,8 @@ internal object RPCDeclarationScanner {
             }
         }
 
-        val packageName = service.packageFqName?.asString()
-            ?: error("Expected package name of the ${service.name.asString()}")
-
         val stubClassNotNull = stubClass
-        // only for KSP generation
-            ?: ctx.getIrClassSymbol(
-                packageName = packageName,
-                name = "${service.name.asString()}${RpcNames.SERVICE_STUB_NAME_KSP.asString()}"
-            ).owner
+            ?: error("Expected generated stub class to be present in ${service.name.asString()}. FIR failed to do so.")
 
         return ServiceDeclaration(
             service = service,

compiler-plugin/compiler-plugin-backend/src/main/core/kotlinx/rpc/codegen/extension/RPCStubGenerator.kt

@@ -7,7 +7,6 @@ package kotlinx.rpc.codegen.extension
 import kotlinx.rpc.codegen.VersionSpecificApi
 import kotlinx.rpc.codegen.VersionSpecificApiImpl.copyToVS
 import kotlinx.rpc.codegen.common.rpcMethodClassName
-import kotlinx.rpc.codegen.common.rpcMethodClassNameKsp
 import org.jetbrains.kotlin.backend.common.lower.DeclarationIrBuilder
 import org.jetbrains.kotlin.backend.jvm.functionByName
 import org.jetbrains.kotlin.cli.common.messages.MessageCollector
@@ -156,7 +155,7 @@ internal class RPCStubGenerator(
         propertyName: String,
         propertyType: IrType,
         valueParameter: IrValueParameter,
-        propertyVisibility: DescriptorVisibility = DescriptorVisibilities.PRIVATE
+        propertyVisibility: DescriptorVisibility = DescriptorVisibilities.PRIVATE,
     ): IrProperty {
         return addConstructorProperty(Name.identifier(propertyName), propertyType, valueParameter, propertyVisibility)
     }
@@ -165,7 +164,7 @@ internal class RPCStubGenerator(
         propertyName: Name,
         propertyType: IrType,
         valueParameter: IrValueParameter,
-        propertyVisibility: DescriptorVisibility = DescriptorVisibilities.PRIVATE
+        propertyVisibility: DescriptorVisibility = DescriptorVisibilities.PRIVATE,
     ): IrProperty {
         return addProperty {
             name = propertyName
@@ -537,8 +536,7 @@ internal class RPCStubGenerator(
         val isMethodObject = method.arguments.isEmpty()
 
         val methodClassName = method.function.name.rpcMethodClassName
-        val methodClassNameKsp = method.function.name.rpcMethodClassNameKsp
-        val methodClass: IrClass = initiateAndGetMethodClass(methodClassName, methodClassNameKsp, method)
+        val methodClass: IrClass = initiateAndGetMethodClass(methodClassName, method)
 
         addFunction {
             name = method.function.name
@@ -652,17 +650,12 @@ internal class RPCStubGenerator(
      * }
      * ```
      */
-    private fun IrClass.initiateAndGetMethodClass(
-        methodClassName: Name,
-        methodClassNameKsp: Name,
-        method: ServiceDeclaration.Method
-    ): IrClass {
-        val methodClass = findDeclaration<IrClass> {
-            it.name == methodClassName || it.name == methodClassNameKsp
-        } ?: error(
-            "Expected $methodClassName or $methodClassNameKsp class to be present in stub class " +
-                    "${declaration.service.name}${declaration.stubClass.name}"
-        )
+    private fun IrClass.initiateAndGetMethodClass(methodClassName: Name, method: ServiceDeclaration.Method): IrClass {
+        val methodClass = findDeclaration<IrClass> { it.name == methodClassName }
+            ?: error(
+                "Expected $methodClassName class to be present in stub class " +
+                        "${declaration.service.name}${declaration.stubClass.name}"
+            )
 
         methodClasses.add(methodClass)
 
@@ -764,7 +757,7 @@ internal class RPCStubGenerator(
         functionThisReceiver: IrValueParameter,
         isMethodObject: Boolean,
         methodClass: IrClass,
-        arguments: List<IrValueParameter>
+        arguments: List<IrValueParameter>,
     ): IrCall {
         val call = irCall(
             callee = ctx.functions.rpcClientCall.symbol,