Update Kotlin to 2.1.0 (#4284)

* Bump Kotlin version to 2.1
* Warnings cleanup
* Update Kotlin version in integration tests
* Upgrade Gradle in integration tests
* Fix classloading test after more precise Gradle classpath resolution

gradle.properties

@@ -1,8 +1,8 @@
 # Kotlin
 version=1.9.0-SNAPSHOT
 group=org.jetbrains.kotlinx
-kotlin_version=2.0.0
-kotlin_language_version=2.0
+kotlin_version=2.1.0
+kotlin_language_version=2.1
 # DO NOT rename this property without adapting kotlinx.train build chain:
 atomicfu_version=0.26.1
 
@@ -43,7 +43,6 @@ kotlin.native.ignoreDisabledTargets=true
 # TODO: Remove once KT-37187 is fixed
 org.gradle.jvmargs=-Xmx3g
 
-kotlin.mpp.stability.nowarn=true
 kotlinx.atomicfu.enableJvmIrTransformation=true
 # When the flag below is set to `true`, AtomicFU cannot process
 # usages of `moveForward` in `ConcurrentLinkedList.kt` correctly.

integration-testing/build.gradle

@@ -122,6 +122,7 @@ sourceSets {
 compileDebugAgentTestKotlin {
     kotlinOptions {
         freeCompilerArgs += ["-Xallow-kotlin-package"]
+        jvmTarget = "1.8"
     }
 }
 
@@ -163,19 +164,26 @@ task coreAgentTest(type: Test) {
 }
 
 compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
+    kotlinOptions.jvmTarget = "17"
 }
 
 check {
     dependsOn([jvmCoreTest, debugDynamicAgentTest, mavenTest, debugAgentTest, coreAgentTest, ":jpmsTest:check", 'smokeTest:build', "java8Test:check"])
 }
+
 compileKotlin {
     kotlinOptions {
-        jvmTarget = "1.8"
+        jvmTarget = "17"
     }
 }
 
+kotlin.jvmToolchain(17)
+
 // Drop this when node js version become stable
 tasks.withType(org.jetbrains.kotlin.gradle.targets.js.npm.tasks.KotlinNpmInstallTask.class).configureEach {
     it.args.add("--ignore-engines")
 }
+
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile.class).configureEach {
+    jvmTargetValidationMode = org.jetbrains.kotlin.gradle.dsl.jvm.JvmTargetValidationMode.WARNING
+}

integration-testing/gradle.properties

@@ -1,4 +1,4 @@
-kotlin_version=2.0.0
+kotlin_version=2.1.0
 coroutines_version=1.9.0-SNAPSHOT
 asm_version=9.3
 junit5_version=5.7.0

integration-testing/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-all.zip
+networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

integration-testing/gradlew

@@ -15,6 +15,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 
 ##############################################################################
 #
@@ -55,7 +57,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,13 +82,12 @@ do
     esac
 done
 
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-APP_NAME="Gradle"
+# This is normally unused
+# shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s
+' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -133,22 +134,29 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -193,18 +201,28 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
         -classpath "$CLASSPATH" \
         org.gradle.wrapper.GradleWrapperMain \
         "$@"
 
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
 # Use "xargs" to parse quoted args.
 #
 # With -n1 it outputs one arg per line, with the quotes and backslashes removed.

integration-testing/gradlew.bat

@@ -13,8 +13,10 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 @rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +27,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,13 +43,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,11 +59,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -75,13 +78,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal

integration-testing/src/debugAgentTest/kotlin/DebugAgentTest.kt

@@ -1,3 +1,5 @@
+@file:OptIn(ExperimentalCoroutinesApi::class)
+
 import org.junit.*
 import kotlinx.coroutines.*
 import kotlinx.coroutines.debug.*

integration-testing/src/jvmCoreTest/kotlin/ListAllCoroutineThrowableSubclassesTest.kt

@@ -31,12 +31,16 @@ class ListAllCoroutineThrowableSubclassesTest {
         "kotlinx.coroutines.channels.ClosedReceiveChannelException",
         "kotlinx.coroutines.flow.internal.ChildCancelledException",
         "kotlinx.coroutines.flow.internal.AbortFlowException",
+        "kotlinx.coroutines.debug.junit5.CoroutinesTimeoutException",
     )
 
     @Test
     fun testThrowableSubclassesAreSerializable() {
         val classes = ClassPath.from(this.javaClass.classLoader)
-            .getTopLevelClassesRecursive("kotlinx.coroutines");
+            .getTopLevelClassesRecursive("kotlinx.coroutines")
+            // Not in the classpath: requires explicit dependency
+            .filter { it.name != "kotlinx.coroutines.debug.CoroutinesBlockHoundIntegration"
+                    && it.name != "kotlinx.coroutines.debug.junit5.CoroutinesTimeoutExtension" };
         val throwables = classes.filter { Throwable::class.java.isAssignableFrom(it.load()) }.map { it.toString() }
         for (throwable in throwables) {
             for (field in throwable.javaClass.declaredFields) {

integration-testing/src/mavenTest/kotlin/MavenPublicationMetaInfValidator.kt

@@ -48,10 +48,10 @@ class MavenPublicationMetaInfValidator {
     private fun JarFile.checkMetaInfStructure(expected: Set<String>) {
         val actual = HashSet<String>()
         for (e in entries()) {
-            if (e.isDirectory() || !e.realName.contains("META-INF")) {
+            if (e.isDirectory() || !e.name.contains("META-INF")) {
                 continue
             }
-            val partialName = e.realName.substringAfter("META-INF/")
+            val partialName = e.name.substringAfter("META-INF/")
             actual.add(partialName)
         }
 

kotlinx-coroutines-core/common/src/Builders.common.kt

@@ -153,6 +153,7 @@ public suspend fun <T> withContext(
         // FAST PATH #1 -- new context is the same as the old one
         if (newContext === oldContext) {
             val coroutine = ScopeCoroutine(newContext, uCont)
+            @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
             return@sc coroutine.startUndispatchedOrReturn(coroutine, block)
         }
         // FAST PATH #2 -- the new dispatcher is the same as the old one (something else changed)
@@ -161,11 +162,13 @@ public suspend fun <T> withContext(
             val coroutine = UndispatchedCoroutine(newContext, uCont)
             // There are changes in the context, so this thread needs to be updated
             withCoroutineContext(coroutine.context, null) {
+                @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
                 return@sc coroutine.startUndispatchedOrReturn(coroutine, block)
             }
         }
         // SLOW PATH -- use new dispatcher
         val coroutine = DispatchedCoroutine(newContext, uCont)
+        @Suppress("LEAKED_IN_PLACE_LAMBDA")  // Contract is preserved, invoked immediately or throws
         block.startCoroutineCancellable(coroutine, coroutine)
         coroutine.getResult()
     }

kotlinx-coroutines-core/common/src/CoroutineScope.kt

@@ -281,6 +281,7 @@ public suspend fun <R> coroutineScope(block: suspend CoroutineScope.() -> R): R
     }
     return suspendCoroutineUninterceptedOrReturn { uCont ->
         val coroutine = ScopeCoroutine(uCont.context, uCont)
+        @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
         coroutine.startUndispatchedOrReturn(coroutine, block)
     }
 }

kotlinx-coroutines-core/common/src/Supervisor.kt

@@ -53,6 +53,7 @@ public suspend fun <R> supervisorScope(block: suspend CoroutineScope.() -> R): R
     }
     return suspendCoroutineUninterceptedOrReturn { uCont ->
         val coroutine = SupervisorCoroutine(uCont.context, uCont)
+        @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
         coroutine.startUndispatchedOrReturn(coroutine, block)
     }
 }

kotlinx-coroutines-core/common/src/Timeout.kt

@@ -40,6 +40,7 @@ public suspend fun <T> withTimeout(timeMillis: Long, block: suspend CoroutineSco
     }
     if (timeMillis <= 0L) throw TimeoutCancellationException("Timed out immediately")
     return suspendCoroutineUninterceptedOrReturn { uCont ->
+        @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
         setupTimeout(TimeoutCoroutine(timeMillis, uCont), block)
     }
 }

kotlinx-coroutines-core/common/src/internal/Synchronized.common.kt

@@ -24,5 +24,6 @@ public inline fun <T> synchronized(lock: SynchronizedObject, block: () -> T): T
     contract {
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
+    @Suppress("LEAKED_IN_PLACE_LAMBDA") // Contract is preserved, invoked immediately or throws
     return synchronizedImpl(lock, block)
 }

kotlinx-coroutines-core/common/test/SupervisorTest.kt

@@ -1,5 +1,3 @@
-@file:Suppress("NAMED_ARGUMENTS_NOT_ALLOWED") // KT-21913
-
 package kotlinx.coroutines
 
 import kotlinx.coroutines.testing.*

kotlinx-coroutines-core/concurrent/src/internal/LockFreeLinkedList.kt

@@ -1,5 +1,3 @@
-@file:Suppress("NO_EXPLICIT_VISIBILITY_IN_API_MODE")
-
 package kotlinx.coroutines.internal
 
 import kotlinx.atomicfu.*

kotlinx-coroutines-core/jvm/src/internal/Concurrent.kt

@@ -3,12 +3,10 @@ package kotlinx.coroutines.internal
 import java.util.*
 import kotlin.concurrent.withLock as withLockJvm
 
-@Suppress("ACTUAL_WITHOUT_EXPECT")
 internal actual typealias ReentrantLock = java.util.concurrent.locks.ReentrantLock
 
 internal actual inline fun <T> ReentrantLock.withLock(action: () -> T) = this.withLockJvm(action)
 
-@Suppress("ACTUAL_WITHOUT_EXPECT") // Visibility
 internal actual typealias WorkaroundAtomicReference<T> = java.util.concurrent.atomic.AtomicReference<T>
 
 // BenignDataRace is OptionalExpectation and doesn't have to be here

kotlinx-coroutines-core/jvm/src/internal/InternalAnnotations.kt

@@ -1,4 +1,3 @@
 package kotlinx.coroutines.internal
 
-@Suppress("ACTUAL_WITHOUT_EXPECT") // Not the same name to WA the bug in the compiler
 internal actual typealias IgnoreJreRequirement = org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

kotlinx-coroutines-core/jvm/src/internal/LocalAtomics.kt

@@ -1,4 +1,3 @@
 package kotlinx.coroutines.internal
 
-@Suppress("ACTUAL_WITHOUT_EXPECT")
 internal actual typealias LocalAtomicInt = java.util.concurrent.atomic.AtomicInteger

kotlinx-coroutines-core/jvm/src/internal/StackTraceRecovery.kt

@@ -198,10 +198,8 @@ private fun StackTraceElement.elementWiseEquals(e: StackTraceElement): Boolean {
             && fileName == e.fileName && className == e.className
 }
 
-@Suppress("ACTUAL_WITHOUT_EXPECT")
 internal actual typealias CoroutineStackFrame = kotlin.coroutines.jvm.internal.CoroutineStackFrame
 
-@Suppress("ACTUAL_WITHOUT_EXPECT")
 internal actual typealias StackTraceElement = java.lang.StackTraceElement
 
 @Suppress("EXTENSION_SHADOWED_BY_MEMBER")

kotlinx-coroutines-core/jvm/src/internal/ThreadLocal.kt

@@ -2,7 +2,6 @@ package kotlinx.coroutines.internal
 
 import java.lang.ThreadLocal
 
-@Suppress("ACTUAL_WITHOUT_EXPECT") // internal visibility
 internal actual typealias CommonThreadLocal<T> = ThreadLocal<T>
 
 internal actual fun<T> commonThreadLocal(name: Symbol): CommonThreadLocal<T> = ThreadLocal()