Kotlin compiler should run first.

modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/api/ICompilerContributor.kt

@@ -2,7 +2,7 @@ package com.beust.kobalt.api
 
 import com.beust.kobalt.TaskResult
 
-interface ICompiler {
+interface ICompiler : Comparable<ICompiler> {
     /**
      * The suffixes handled by this compiler (without the dot, e.g. "java" or "kt").
      */
@@ -17,6 +17,17 @@ interface ICompiler {
      * Run the compilation based on the info.
      */
     fun compile(project: Project, context: KobaltContext, info: CompilerActionInfo) : TaskResult
+
+    companion object {
+        val DEFAULT_PRIORITY: Int = 5
+    }
+
+    /**
+     * The priority of this compiler. Lower priority compilers are run first.
+     */
+    val priority: Int get() = DEFAULT_PRIORITY
+
+    override fun compareTo(other: ICompiler) = priority.compareTo(other.priority)
 }
 
 interface ICompilerContributor : IProjectAffinity {

modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/internal/JvmCompilerPlugin.kt

@@ -194,29 +194,28 @@ open class JvmCompilerPlugin @Inject constructor(
         if (compilerContributors.isEmpty()) {
             throw KobaltException("Couldn't find any compiler for project ${project.name}")
         } else {
-            compilerContributors.forEach { contributor ->
+            val allCompilers = compilerContributors.flatMap { it.compilersFor(project, context)}.sorted()
-                contributor.compilersFor(project, context).forEach { compiler ->
+            allCompilers.forEach { compiler ->
-                    val contributedSourceDirs =
+                val contributedSourceDirs =
-                        if (isTest) {
+                    if (isTest) {
-                            context.testSourceDirectories(project)
+                        context.testSourceDirectories(project)
-                        } else {
-                            context.sourceDirectories(project)
-                        }
-                    val sourceFiles = KFiles.findSourceFiles(project.directory,
-                            contributedSourceDirs.map { it.path }, compiler.sourceSuffixes)
-                    if (sourceFiles.size > 0) {
-                        // TODO: createCompilerActionInfo recalculates the source files, only compute them
-                        // once and pass them
-                        val info = createCompilerActionInfo(project, context, isTest, sourceDirectories,
-                                sourceSuffixes = compiler.sourceSuffixes)
-                        val thisResult = compiler.compile(project, context, info)
-                        results.add(thisResult)
-                        if (!thisResult.success && failedResult == null) {
-                            failedResult = thisResult
-                        }
                     } else {
-                        log(2, "Compiler $compiler not running on ${project.name} since no source files were found")
+                        context.sourceDirectories(project)
                     }
+                val sourceFiles = KFiles.findSourceFiles(project.directory,
+                        contributedSourceDirs.map { it.path }, compiler.sourceSuffixes)
+                if (sourceFiles.size > 0) {
+                    // TODO: createCompilerActionInfo recalculates the source files, only compute them
+                    // once and pass them
+                    val info = createCompilerActionInfo(project, context, isTest, sourceDirectories,
+                            sourceSuffixes = compiler.sourceSuffixes)
+                    val thisResult = compiler.compile(project, context, info)
+                    results.add(thisResult)
+                    if (!thisResult.success && failedResult == null) {
+                        failedResult = thisResult
+                    }
+                } else {
+                    log(2, "Compiler $compiler not running on ${project.name} since no source files were found")
                 }
             }
             return if (failedResult != null) failedResult!!

src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinPlugin.kt

@@ -19,8 +19,7 @@ import javax.inject.Singleton
 @Singleton
 class KotlinPlugin @Inject constructor(val executors: KobaltExecutors, val dependencyManager: DependencyManager,
         override val configActor: ConfigActor<KotlinConfig>)
-    : BaseJvmPlugin<KotlinConfig>(configActor), IDocContributor, IClasspathContributor, ICompilerContributor,
+    : BaseJvmPlugin<KotlinConfig>(configActor), IDocContributor, IClasspathContributor, ICompilerContributor, IBuildConfigContributor {
-        IBuildConfigContributor {
 
     companion object {
         const val PLUGIN_NAME = "Kotlin"
@@ -116,6 +115,9 @@ class KotlinPlugin @Inject constructor(val executors: KobaltExecutors, val depen
     val compiler = object: ICompiler {
         override val sourceSuffixes = listOf("kt")
 
+        /** The Kotlin compiler should run before the Java one */
+        override val priority: Int get() = ICompiler.DEFAULT_PRIORITY - 1
+
         override val sourceDirectory = "kotlin"
 
         override fun compile(project: Project, context: KobaltContext, info: CompilerActionInfo): TaskResult {