Clean up Kotlin code in buildSrc/ (#1512)

- fix most IntelliJ warnings (regex refactoring was done by IDE)
- replace hardcoded JVM target versions with BuildInfo.jvmTarget

buildSrc/src/main/kotlin/ExecutableJar.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,6 +36,7 @@ abstract class ExecutableJar : DefaultTask() {
   @get:Input abstract val jvmArgs: ListProperty<String>
 
   @TaskAction
+  @Suppress("unused")
   fun buildJar() {
     val inFile = inJar.get().asFile
     val outFile = outJar.get().asFile

buildSrc/src/main/kotlin/MergeSourcesJars.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -57,7 +57,7 @@ open class MergeSourcesJars : DefaultTask() {
     // a word or a period character. should catch most cases.
     val importPattern =
       Pattern.compile(
-        "(?<!(\\w|\\.))(" + relocatedPkgs.keys.joinToString("|") { it.replace(".", "\\.") } + ")"
+        "(?<!([\\w.]))(" + relocatedPkgs.keys.joinToString("|") { it.replace(".", "\\.") } + ")"
       )
 
     val sourceFileExts = sourceFileExtensions.get()

buildSrc/src/main/kotlin/NativeImageBuild.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -102,6 +102,7 @@ abstract class NativeImageBuild : DefaultTask() {
   }
 
   @TaskAction
+  @Suppress("unused")
   protected fun run() {
     execOperations.exec {
       val exclusions =

buildSrc/src/main/kotlin/pklAllProjects.gradle.kts

@@ -52,14 +52,14 @@ configurations.all {
 }
 
 plugins.withType(JavaPlugin::class).configureEach {
-  tasks.withType<JavaCompile>().configureEach { options.release = 17 }
+  tasks.withType<JavaCompile>().configureEach { options.release = buildInfo.jvmTarget }
 }
 
 tasks.withType<KotlinJvmCompile>().configureEach {
   compilerOptions {
-    jvmTarget = JvmTarget.JVM_17
+    jvmTarget = JvmTarget.fromTarget(buildInfo.jvmTarget.toString())
     freeCompilerArgs.addAll("-Xjsr305=strict", "-Xjvm-default=all")
-    freeCompilerArgs.add("-Xjdk-release=17")
+    freeCompilerArgs.add("-Xjdk-release=${buildInfo.jvmTarget}")
   }
 }
 
@@ -110,7 +110,6 @@ tasks.withType(Test::class).configureEach {
   }
   debugOptions {
     enabled = System.getProperty("jvmdebug")?.toBoolean() ?: false
-    @Suppress("UnstableApiUsage")
     host = "*"
     port = 5005
     suspend = true
@@ -121,7 +120,6 @@ tasks.withType(Test::class).configureEach {
 tasks.withType(JavaExec::class).configureEach {
   debugOptions {
     enabled = System.getProperty("jvmdebug")?.toBoolean() ?: false
-    @Suppress("UnstableApiUsage")
     host = "*"
     port = 5005
     suspend = true

buildSrc/src/main/kotlin/pklGradlePluginTest.gradle.kts

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@ tasks.addRule("Pattern: compatibilityTest[All|Releases|Latest|Candidate|Nightly|
   val taskName = this
   val matchResult = Regex("compatibilityTest(.+)").matchEntire(taskName) ?: return@addRule
 
+  // https://github.com/gradle/gradle/issues/32599
+  @Suppress("DEPRECATION")
   when (val taskNameSuffix = matchResult.groupValues[1]) {
     "All" ->
       task("compatibilityTestAll") {

buildSrc/src/main/kotlin/pklJavaExecutable.gradle.kts

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -72,7 +72,7 @@ fun Task.setupTestStartJavaExecutable(launcher: Provider<JavaLauncher>? = null)
     outputFile.get().asFile.toPath().apply {
       try {
         parent.createDirectories()
-      } catch (ignored: java.nio.file.FileAlreadyExistsException) {}
+      } catch (_: java.nio.file.FileAlreadyExistsException) {}
       writeText("OK")
     }
   }

buildSrc/src/main/kotlin/pklNativeExecutable.gradle.kts

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2025-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -161,7 +161,7 @@ val testStartNativeExecutable by
       outputFile.get().asFile.toPath().apply {
         try {
           parent.createDirectories()
-        } catch (ignored: java.nio.file.FileAlreadyExistsException) {}
+        } catch (_: java.nio.file.FileAlreadyExistsException) {}
         writeText("OK")
       }
     }