Refactor host configuration handling and script definition creation

so it is possible now to create custom host configuration with template
and all configurations are handled consistenly.
Also introduce and use new ScriptDefinition class wrapping compilation
and evaluation configurations, that could be consistenly created from a
template.

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/definitions/LazyScriptDefinitionFromDiscoveredClass.kt

@@ -8,14 +8,11 @@ package org.jetbrains.kotlin.scripting.definitions
 import java.io.File
 import kotlin.script.experimental.annotations.KotlinScript
 import kotlin.script.experimental.api.*
-import kotlin.script.experimental.host.ScriptingHostConfiguration
-import kotlin.script.experimental.host.configurationDependencies
-import kotlin.script.experimental.host.createCompilationConfigurationFromTemplate
-import kotlin.script.experimental.host.createEvaluationConfigurationFromTemplate
+import kotlin.script.experimental.host.*
 import kotlin.script.experimental.jvm.JvmDependency
 
 class LazyScriptDefinitionFromDiscoveredClass internal constructor(
-    baseHostConfiguration: ScriptingHostConfiguration,
+    private val baseHostConfiguration: ScriptingHostConfiguration,
     private val annotationsFromAsm: ArrayList<BinAnnData>,
     private val className: String,
     private val classpath: List<File>,
@@ -30,31 +27,21 @@ class LazyScriptDefinitionFromDiscoveredClass internal constructor(
         messageReporter: MessageReporter
     ) : this(baseHostConfiguration, loadAnnotationsFromClass(classBytes), className, classpath, messageReporter)
 
-    override val hostConfiguration: ScriptingHostConfiguration by lazy(LazyThreadSafetyMode.PUBLICATION) {
-        ScriptingHostConfiguration(baseHostConfiguration) {
-            configurationDependencies.append(JvmDependency(classpath))
-        }
-    }
-
-    private val configurations by lazy(LazyThreadSafetyMode.PUBLICATION) {
+    private val definition: kotlin.script.experimental.host.ScriptDefinition by lazy(LazyThreadSafetyMode.PUBLICATION) {
         messageReporter(
             ScriptDiagnostic.Severity.DEBUG,
             "Configure scripting: loading script definition class $className using classpath $classpath\n.  ${Thread.currentThread().stackTrace}"
         )
         try {
-            val compileCfg =
-                createCompilationConfigurationFromTemplate(
-                    KotlinType(className),
-                    hostConfiguration,
-                    LazyScriptDefinitionFromDiscoveredClass::class
-                )
-            val evalCfg =
-                createEvaluationConfigurationFromTemplate(
-                    KotlinType(className),
-                    hostConfiguration,
-                    LazyScriptDefinitionFromDiscoveredClass::class
-                )
-            compileCfg to evalCfg
+            createScriptDefinitionFromTemplate(
+                KotlinType(className),
+                baseHostConfiguration.with {
+                    if (classpath.isNotEmpty()) {
+                        configurationDependencies.append(JvmDependency(classpath))
+                    }
+                },
+                LazyScriptDefinitionFromDiscoveredClass::class
+            )
         } catch (ex: ClassNotFoundException) {
             messageReporter(ScriptDiagnostic.Severity.ERROR, "Cannot find script definition class $className")
             InvalidScriptDefinition
@@ -67,8 +54,11 @@ class LazyScriptDefinitionFromDiscoveredClass internal constructor(
         }
     }
 
-    override val compilationConfiguration: ScriptCompilationConfiguration get() = configurations.first
-    override val evaluationConfiguration: ScriptEvaluationConfiguration get() = configurations.second
+    override val hostConfiguration: ScriptingHostConfiguration
+        get() = definition.compilationConfiguration[ScriptCompilationConfiguration.hostConfiguration] ?: baseHostConfiguration
+
+    override val compilationConfiguration: ScriptCompilationConfiguration get() = definition.compilationConfiguration
+    override val evaluationConfiguration: ScriptEvaluationConfiguration get() = definition.evaluationConfiguration
 
     override val fileExtension: String by lazy(LazyThreadSafetyMode.PUBLICATION) {
         annotationsFromAsm.find { it.name == KotlinScript::class.java.simpleName }?.args
@@ -84,4 +74,5 @@ class LazyScriptDefinitionFromDiscoveredClass internal constructor(
     }
 }
 
-val InvalidScriptDefinition = ScriptCompilationConfiguration() to ScriptEvaluationConfiguration()
+val InvalidScriptDefinition =
+    ScriptDefinition(ScriptCompilationConfiguration(), ScriptEvaluationConfiguration())

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/definitions/ScriptDefinition.kt

@@ -11,9 +11,7 @@ import org.jetbrains.kotlin.scripting.resolve.KotlinScriptDefinitionFromAnnotate
 import java.io.File
 import kotlin.reflect.KClass
 import kotlin.script.experimental.api.*
-import kotlin.script.experimental.host.ScriptingHostConfiguration
-import kotlin.script.experimental.host.createCompilationConfigurationFromTemplate
-import kotlin.script.experimental.host.createEvaluationConfigurationFromTemplate
+import kotlin.script.experimental.host.*
 import kotlin.script.experimental.jvm.baseClassLoader
 import kotlin.script.experimental.jvm.jvm
 
@@ -181,14 +179,19 @@ abstract class ScriptDefinition : UserDataHolderBase() {
     ) : FromConfigurationsBase()
 
     open class FromTemplate(
-        hostConfiguration: ScriptingHostConfiguration,
+        private val baseHostConfiguration: ScriptingHostConfiguration,
         template: KClass<*>,
         contextClass: KClass<*> = ScriptCompilationConfiguration::class
-    ) : FromConfigurations(
-        hostConfiguration,
-        createCompilationConfigurationFromTemplate(KotlinType(template), hostConfiguration, contextClass),
-        createEvaluationConfigurationFromTemplate(KotlinType(template), hostConfiguration, contextClass)
-    )
+    ) : FromConfigurationsBase() {
+
+        private val definition = createScriptDefinitionFromTemplate(KotlinType(template), baseHostConfiguration, contextClass)
+
+        override val hostConfiguration: ScriptingHostConfiguration
+            get() = definition.compilationConfiguration[ScriptCompilationConfiguration.hostConfiguration] ?: baseHostConfiguration
+
+        override val compilationConfiguration: ScriptCompilationConfiguration get() = definition.compilationConfiguration
+        override val evaluationConfiguration: ScriptEvaluationConfiguration get() = definition.evaluationConfiguration
+    }
 
     companion object {
         fun getDefault(hostConfiguration: ScriptingHostConfiguration) =