Support JVM META-INF generation

sweetspi-compiler-plugin/src/main/kotlin/SweetCommandLineProcessor.kt

@@ -5,9 +5,32 @@
 package dev.whyoleg.sweetspi.compiler
 
 import org.jetbrains.kotlin.compiler.plugin.*
+import org.jetbrains.kotlin.config.*
+import kotlin.io.path.*
 
 @OptIn(ExperimentalCompilerApi::class)
 class SweetCommandLineProcessor : CommandLineProcessor {
     override val pluginId: String = "dev.whyoleg.sweetspi"
-    override val pluginOptions: Collection<CliOption> = emptyList()
+    override val pluginOptions: Collection<CliOption> = listOf(
+        RESOURCES_PATH
+    )
+
+    override fun processOption(
+        option: AbstractCliOption,
+        value: String,
+        configuration: CompilerConfiguration,
+    ): Unit = when (option.optionName) {
+        RESOURCES_PATH.optionName -> configuration.put(SweetConfigurationKeys.RESOURCES_PATH, Path(value))
+        else                      -> error("Unknown plugin option: ${option.optionName}")
+    }
+
+    companion object {
+        private val RESOURCES_PATH = CliOption(
+            optionName = "resourcesPath",
+            valueDescription = "<path>",
+            description = SweetConfigurationKeys.RESOURCES_PATH.toString(),
+            required = true,
+            allowMultipleOccurrences = false,
+        )
+    }
 }

sweetspi-compiler-plugin/src/main/kotlin/SweetCompilerPluginRegistrar.kt

@@ -16,6 +16,11 @@ class SweetCompilerPluginRegistrar : CompilerPluginRegistrar() {
 
     override fun ExtensionStorage.registerExtensions(configuration: CompilerConfiguration) {
         FirExtensionRegistrarAdapter.registerExtension(SweetFirExtensionRegistrar())
-        IrGenerationExtension.registerExtension(SweetIrGenerationExtension(configuration.irMessageLogger))
+        IrGenerationExtension.registerExtension(
+            SweetIrGenerationExtension(
+                configuration.irMessageLogger,
+                configuration.getNotNull(SweetConfigurationKeys.RESOURCES_PATH)
+            )
+        )
     }
 }

sweetspi-compiler-plugin/src/main/kotlin/SweetConfigurationKeys.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2025 Oleg Yukhnevich. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package dev.whyoleg.sweetspi.compiler
+
+import org.jetbrains.kotlin.config.*
+import java.nio.file.*
+
+object SweetConfigurationKeys {
+    val RESOURCES_PATH = CompilerConfigurationKey<Path>("Path to resources dir")
+}

sweetspi-compiler-plugin/src/main/kotlin/SweetIrGenerationExtension.kt

@@ -17,6 +17,8 @@ import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.*
 import org.jetbrains.kotlin.platform.jvm.*
+import java.nio.file.*
+import kotlin.io.path.*
 
 private val SweetOrigin: IrDeclarationOrigin = IrDeclarationOriginImpl("SWEET_SPI")
 
@@ -38,6 +40,7 @@ private val SweetOrigin: IrDeclarationOrigin = IrDeclarationOriginImpl("SWEET_SP
 @OptIn(UnsafeDuringIrConstructionAPI::class)
 class SweetIrGenerationExtension(
     private val logger: IrMessageLogger,
+    private val resourcesPath: Path,
 ) : IrGenerationExtension {
 
     override fun generate(moduleFragment: IrModuleFragment, pluginContext: IrPluginContext) {
@@ -60,17 +63,12 @@ class SweetIrGenerationExtension(
         }.associateBy(IrClass::classIdOrFail) // should be called ONLY after `addChild`
 
         // handle @ServiceProvider
-        moduleFragment.files.forEach { file ->
+        val serviceProviders = moduleFragment.files.flatMap { file ->
             file.declarations.flatMap { declaration ->
                 val serviceTypes = findDeclaredServiceTypes(declaration)
                     ?.ifEmpty { resolveServiceTypes(declaration) }
                     ?: return@flatMap emptyList()
 
-//                messageCollector.report(
-//                    CompilerMessageSeverity.WARNING,
-//                    "$declaration: ${serviceTypes.joinToString { it.classFqName!!.asString() }}"
-//                )
-
                 // TODO: add checkers for invalid combinations
                 when (declaration) {
                     is IrClass          -> buildJvmServiceProviderImplClasses(
@@ -102,7 +100,17 @@ class SweetIrGenerationExtension(
                     }
                     else                -> emptyList()
                 }
-            }.forEach(file::addChild)
+            }.onEach(file::addChild)
+        }.groupBy { it.superTypes.single() }
+
+        // drop all resources first
+        resourcesPath.toFile().deleteRecursively()
+        serviceProviders.forEach { (superType, providers) ->
+            resourcesPath.resolve(
+                "META-INF/services/${superType.classOrFail.owner.kotlinFqName.asString()}"
+            ).createParentDirectories().writeText(
+                providers.joinToString("\n") { it.kotlinFqName.asString() }
+            )
         }
     }
 

sweetspi-gradle-plugin/src/main/kotlin/SweetSpiPlugin.kt

@@ -71,8 +71,25 @@ public abstract class SweetSpiPlugin @Inject constructor(
     )
 
     override fun isApplicable(kotlinCompilation: KotlinCompilation<*>): Boolean = true
+
     override fun applyToCompilation(kotlinCompilation: KotlinCompilation<*>): Provider<List<SubpluginOption>> {
-        // TODO: for JVM we should provide folder for resources
-        return kotlinCompilation.target.project.provider { emptyList() }
+        val project = kotlinCompilation.target.project
+
+        val resourcesPath = project.layout.buildDirectory.dir(
+            "generated/sweetspi/${kotlinCompilation.defaultSourceSet.name}/resources"
+        )
+        // cross-link compilation and resource processing tasks via resources dir output
+        kotlinCompilation.compileTaskProvider.configure {
+            it.outputs.dir(resourcesPath).withPropertyName("sweetspi.resourcesPath")
+        }
+        kotlinCompilation.defaultSourceSet.resources.srcDir(
+            kotlinCompilation.compileTaskProvider.map { resourcesPath.get() }
+        )
+
+        return project.provider {
+            listOf(
+                SubpluginOption("resourcesPath", resourcesPath.get().toString())
+            )
+        }
     }
 }