Pass compilation args using the official way

src/main/kotlin/io/bazel/kotlin/builder/tasks/jvm/CompilationArgs.kt

@@ -125,7 +125,8 @@ class CompilationArgs(
     return value(
       toArgs(
         paths.asSequence()
-          .map { dfs.getPath(it) })
+          .map { dfs.getPath(it) }
+      )
     )
   }
 
@@ -167,11 +168,27 @@ class CompilationArgs(
     return this
   }
 
-  fun xFlag(flag: String, value: String): CompilationArgs {
+  fun xFlag(
+    flag: String,
+    value: String
+  ): CompilationArgs {
     args.add("-X$flag=$value")
     return this
   }
 
+  fun repeatFlag(
+    flag: String,
+    vararg values: Pair<String, List<String>>,
+    transform: (option: String, value: String) -> String
+  ): CompilationArgs {
+    values.forEach { (option, values) ->
+      values.forEach {
+        flag(flag, transform(option, it))
+      }
+    }
+    return this
+  }
+
   fun list(): List<String> = args.toList()
 
   fun base64Encode(

src/main/kotlin/io/bazel/kotlin/builder/tasks/jvm/compilation_task.kt

@@ -110,7 +110,9 @@ internal fun JvmCompilationTask.plugins(
     }
   }
 
-internal fun JvmCompilationTask.preProcessingSteps(context: CompilationTaskContext): JvmCompilationTask {
+internal fun JvmCompilationTask.preProcessingSteps(
+  context: CompilationTaskContext
+): JvmCompilationTask {
   return context.execute("expand sources") { expandWithSourceJarSources() }
 }
 
@@ -138,10 +140,10 @@ internal fun JvmCompilationTask.kaptArgs(
     "-target" to info.toolchainInfo.jvm.jvmTarget,
     "-source" to info.toolchainInfo.jvm.jvmTarget
   )
-  return CompilationArgs()
-    .xFlag("plugin", plugins.kapt.jarPath)
-    .base64Encode(
-      "-P",
+  return CompilationArgs().apply {
+    xFlag("plugin", plugins.kapt.jarPath)
+
+    val values = arrayOf(
       "sources" to listOf(directories.generatedJavaSources),
       "classes" to listOf(directories.generatedClasses),
       "stubs" to listOf(directories.stubs),
@@ -152,15 +154,35 @@ internal fun JvmCompilationTask.kaptArgs(
       "processors" to listOf(inputs.processorsList.joinToString(",")),
       "apclasspath" to inputs.processorpathsList,
       "aptMode" to listOf(aptMode)
-    ) { enc -> "plugin:${plugins.kapt.id}:configuration=$enc" }
+    )
+
+    val version = info.toolchainInfo.common.apiVersion.toFloat()
+    when {
+      version < 1.5 -> base64Encode(
+        "-P",
+        *values
+      ) { enc -> "plugin:${plugins.kapt.id}:configuration=$enc" }
+      else -> repeatFlag(
+        "-P",
+        *values
+      ) { option, value ->
+        "plugin:${plugins.kapt.id}:$option=$value"
+      }
+    }
+  }
 }
 
 internal fun JvmCompilationTask.runPlugins(
   context: CompilationTaskContext,
   plugins: InternalCompilerPlugins,
   compiler: KotlinToolchain.KotlincInvoker
 ): JvmCompilationTask {
-  if ((inputs.processorsList.isEmpty() && inputs.stubsPluginsList.isEmpty()) || inputs.kotlinSourcesList.isEmpty()) {
+  if ((
+    inputs.processorsList.isEmpty() &&
+      inputs.stubsPluginsList.isEmpty()
+    ) ||
+    inputs.kotlinSourcesList.isEmpty()
+  ) {
     return this
   } else {
     return context.execute("kapt (${inputs.processorsList.joinToString(", ")})") {
@@ -175,14 +197,15 @@ internal fun JvmCompilationTask.runPlugins(
           .plus(
             kaptArgs(context, plugins, "stubsAndApt")
           )
-      )
+        )
         .flag("-d", directories.generatedClasses)
         .values(inputs.kotlinSourcesList)
         .values(inputs.javaSourcesList).list().let { args ->
           context.executeCompilerTask(
             args,
             compiler::compile,
-            printOnSuccess = context.whenTracing { false } ?: true)
+            printOnSuccess = context.whenTracing { false } ?: true
+          )
         }.let { outputLines ->
           // if tracing is enabled the output should be formatted in a special way, if we aren't
           // tracing then any compiler output would make it's way to the console as is.
@@ -215,16 +238,16 @@ internal fun JvmCompilationTask.createOutputJar() =
  * Produce the primary output jar.
  */
 internal fun JvmCompilationTask.createAbiJar() =
-    JarCreator(
-        path = Paths.get(outputs.abijar),
-        normalize = true,
-        verbose = false
-    ).also {
-      it.addDirectory(Paths.get(directories.abiClasses))
-      it.addDirectory(Paths.get(directories.generatedClasses))
-      it.setJarOwner(info.label, info.bazelRuleKind)
-      it.execute()
-    }
+  JarCreator(
+    path = Paths.get(outputs.abijar),
+    normalize = true,
+    verbose = false
+  ).also {
+    it.addDirectory(Paths.get(directories.abiClasses))
+    it.addDirectory(Paths.get(directories.generatedClasses))
+    it.setJarOwner(info.label, info.bazelRuleKind)
+    it.execute()
+  }
 
 /**
  * Produce a jar of sources generated by KAPT.
@@ -284,10 +307,12 @@ fun JvmCompilationTask.compileKotlin(
     writeJdeps(outputs.jdeps, emptyJdeps(info.label))
     return emptyList()
   } else {
-    return (args + plugins(
-      options = inputs.compilerPluginOptionsList,
-      classpath = inputs.compilerPluginClasspathList
-    ))
+    return (
+      args + plugins(
+        options = inputs.compilerPluginOptionsList,
+        classpath = inputs.compilerPluginClasspathList
+      )
+      )
       .values(inputs.javaSourcesList)
       .values(inputs.kotlinSourcesList)
       .flag("-d", directories.classes)
@@ -312,7 +337,8 @@ fun JvmCompilationTask.compileKotlin(
                   .flatMap { walk(it) }
                   .filter { !isDirectory(it) }
                   .map { it.toString() }
-                  .collect(toList()))
+                  .collect(toList())
+              )
             }
           }
       }
@@ -368,7 +394,8 @@ private fun JvmCompilationTask.expandWithSources(sources: Iterator<String>): Jvm
   updateBuilder { builder ->
     sources.filterOutNonCompilableSources().partitionJvmSources(
       { builder.inputsBuilder.addKotlinSources(it) },
-      { builder.inputsBuilder.addJavaSources(it) })
+      { builder.inputsBuilder.addJavaSources(it) }
+    )
   }
 
 private fun JvmCompilationTask.updateBuilder(
@@ -383,9 +410,9 @@ private fun JvmCompilationTask.updateBuilder(
  * Only keep java and kotlin files for the iterator. Filter our all other non-compilable files.
  */
 private fun Iterator<String>.filterOutNonCompilableSources(): Iterator<String> {
-   val result = mutableListOf<String>()
-   this.forEach {
-     if (it.endsWith(".kt") or it.endsWith(".java")) result.add(it)
-   }
+  val result = mutableListOf<String>()
+  this.forEach {
+    if (it.endsWith(".kt") or it.endsWith(".java")) result.add(it)
+  }
   return result.iterator()
 }