[Gradle, BT] Move script definitions scanning into the build tools API

#KT-61449 In Progress

compiler/build-tools/kotlin-build-tools-api/api/kotlin-build-tools-api.api

@@ -12,6 +12,7 @@ public abstract interface class org/jetbrains/kotlin/buildtools/api/CompilationS
 	public abstract fun calculateClasspathSnapshot (Ljava/io/File;Lorg/jetbrains/kotlin/buildtools/api/jvm/ClassSnapshotGranularity;)Lorg/jetbrains/kotlin/buildtools/api/jvm/ClasspathEntrySnapshot;
 	public abstract fun compileJvm (Lorg/jetbrains/kotlin/buildtools/api/ProjectId;Lorg/jetbrains/kotlin/buildtools/api/CompilerExecutionStrategyConfiguration;Lorg/jetbrains/kotlin/buildtools/api/jvm/JvmCompilationConfiguration;Ljava/util/List;Ljava/util/List;)Lorg/jetbrains/kotlin/buildtools/api/CompilationResult;
 	public abstract fun finishProjectCompilation (Lorg/jetbrains/kotlin/buildtools/api/ProjectId;)V
+	public abstract fun getCustomKotlinScriptFilenameExtensions (Ljava/util/List;)Ljava/util/Collection;
 	public static fun loadImplementation (Ljava/lang/ClassLoader;)Lorg/jetbrains/kotlin/buildtools/api/CompilationService;
 	public abstract fun makeCompilerExecutionStrategyConfiguration ()Lorg/jetbrains/kotlin/buildtools/api/CompilerExecutionStrategyConfiguration;
 	public abstract fun makeJvmCompilationConfiguration ()Lorg/jetbrains/kotlin/buildtools/api/jvm/JvmCompilationConfiguration;

compiler/build-tools/kotlin-build-tools-api/src/main/kotlin/org/jetbrains/kotlin/buildtools/api/CompilationService.kt

@@ -70,6 +70,14 @@ public interface CompilationService {
      */
     public fun finishProjectCompilation(projectId: ProjectId)
 
+    /**
+     * Retrieves the custom Kotlin script filename extensions based on script definitions from the specified classpath.
+     *
+     * @param classpath The list of files representing the classpath.
+     * @return A collection of strings representing the custom Kotlin script filename extensions.
+     */
+    public fun getCustomKotlinScriptFilenameExtensions(classpath: List<File>): Collection<String>
+
     @ExperimentalBuildToolsApi
     public companion object {
         @JvmStatic

compiler/build-tools/kotlin-build-tools-impl/build.gradle.kts

@@ -14,8 +14,11 @@ dependencies {
     compileOnly(project(":compiler:incremental-compilation-impl"))
     compileOnly(project(":kotlin-compiler-runner-unshaded"))
     compileOnly(intellijCore())
+    compileOnly(project(":kotlin-scripting-compiler"))
     runtimeOnly(project(":kotlin-compiler-embeddable"))
     runtimeOnly(project(":kotlin-compiler-runner"))
+    runtimeOnly(project(":kotlin-scripting-compiler-embeddable"))
+    runtimeOnly(project(":kotlin-scripting-compiler-impl-embeddable"))
 }
 
 publish()

compiler/build-tools/kotlin-build-tools-impl/src/main/kotlin/org/jetbrains/kotlin/buildtools/internal/CompilationServiceImpl.kt

@@ -12,6 +12,8 @@ import org.jetbrains.kotlin.cli.common.ExitCode
 import org.jetbrains.kotlin.cli.common.arguments.parseCommandLineArguments
 import org.jetbrains.kotlin.cli.common.arguments.validateArguments
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
+import org.jetbrains.kotlin.cli.common.messages.MessageRenderer
+import org.jetbrains.kotlin.cli.common.messages.PrintingMessageCollector
 import org.jetbrains.kotlin.cli.jvm.K2JVMCompiler
 import org.jetbrains.kotlin.compilerRunner.KotlinCompilerRunnerUtils
 import org.jetbrains.kotlin.config.Services
@@ -20,9 +22,12 @@ import org.jetbrains.kotlin.daemon.common.CompilerId
 import org.jetbrains.kotlin.daemon.common.configureDaemonJVMOptions
 import org.jetbrains.kotlin.daemon.common.filterExtractProps
 import org.jetbrains.kotlin.incremental.classpathDiff.ClasspathEntrySnapshotter
+import org.jetbrains.kotlin.scripting.compiler.plugin.impl.reporter
+import org.jetbrains.kotlin.scripting.definitions.ScriptDefinitionsFromClasspathDiscoverySource
 import java.io.File
 import java.net.URLClassLoader
 import java.util.concurrent.ConcurrentHashMap
+import kotlin.script.experimental.jvm.defaultJvmScriptingHostConfiguration
 
 private val ExitCode.asCompilationResult
     get() = when (this) {
@@ -77,6 +82,16 @@ internal object CompilationServiceImpl : CompilationService {
         file.delete()
     }
 
+    override fun getCustomKotlinScriptFilenameExtensions(classpath: List<File>): Collection<String> {
+        val definitions = ScriptDefinitionsFromClasspathDiscoverySource(
+            classpath,
+            defaultJvmScriptingHostConfiguration,
+            PrintingMessageCollector(System.out, MessageRenderer.WITHOUT_PATHS, false).reporter
+        ).definitions
+
+        return definitions.mapTo(arrayListOf()) { it.fileExtension }
+    }
+
     private fun compileInProcess(
         loggerAdapter: KotlinLoggerMessageCollectorAdapter,
         sources: List<File>,