Adds AdditionalExtractableAnalyser EP.

Adds annotations to ExtractableCodeDescriptor.
Adds functionality of adding annotations to KtPsiFactory.CallableBuilder

idea/resources/META-INF/extensions/ide.xml

@@ -67,6 +67,9 @@
         <extensionPoint qualifiedName="org.jetbrains.kotlin.scripting.idea.listener"
                         interface="org.jetbrains.kotlin.idea.core.script.configuration.listener.ScriptChangeListener"
                         area="IDEA_PROJECT"/>
+
+        <extensionPoint qualifiedName="org.jetbrains.kotlin.additionalExtractableAnalyser"
+                        interface="org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.AdditionalExtractableAnalyser"/>
     </extensionPoints>
 
     <extensions defaultExtensionNs="org.jetbrains.kotlin">

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/AdditionalExtractableAnalyser.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine
+
+import com.intellij.openapi.extensions.ExtensionPointName
+
+/**
+ * Allows to modify ExtractableCodeDescriptor within [ExtractionData.performAnalysis].
+ */
+interface AdditionalExtractableAnalyser {
+
+    fun amendDescriptor(descriptor: ExtractableCodeDescriptor): ExtractableCodeDescriptor
+
+    companion object {
+        val EP_NAME = ExtensionPointName.create<AdditionalExtractableAnalyser>("org.jetbrains.kotlin.additionalExtractableAnalyser")
+    }
+}

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/ExtractableCodeDescriptor.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.idea.core.replaced
 import org.jetbrains.kotlin.idea.refactoring.KotlinRefactoringBundle
 import org.jetbrains.kotlin.idea.refactoring.introduce.extractionEngine.OutputValue.*
@@ -357,7 +358,8 @@ data class ExtractableCodeDescriptor(
     val replacementMap: MultiMap<KtSimpleNameExpression, Replacement>,
     val controlFlow: ControlFlow,
     val returnType: KotlinType,
-    val modifiers: List<KtKeywordToken> = emptyList()
+    val modifiers: List<KtKeywordToken> = emptyList(),
+    val annotations: List<AnnotationDescriptor> = emptyList()
 ) {
     val name: String get() = suggestedNames.firstOrNull() ?: ""
     val duplicates: List<DuplicateInfo> by lazy { findDuplicates() }
@@ -393,7 +395,8 @@ fun ExtractableCodeDescriptor.copy(
         newReplacementMap,
         controlFlow.copy(oldToNewParameters),
         returnType ?: this.returnType,
-        modifiers
+        modifiers,
+        annotations
     )
 }
 

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/extractableAnalysisUtil.kt

@@ -708,6 +708,9 @@ fun ExtractionData.performAnalysis(): AnalysisResult {
         descriptor = descriptor.copy(modifiers = listOf(KtTokens.SUSPEND_KEYWORD))
     }
 
+    for (analyser in AdditionalExtractableAnalyser.EP_NAME.extensions) {
+        descriptor = analyser.amendDescriptor(descriptor)
+    }
 
     return AnalysisResult(
         descriptor,

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractionEngine/extractorUtil.kt

@@ -61,10 +61,16 @@ private fun buildSignature(config: ExtractionGeneratorConfiguration, renderer: D
         fun TypeParameter.isReified() = originalDeclaration.hasModifier(KtTokens.REIFIED_KEYWORD)
         val shouldBeInline = config.descriptor.typeParameters.any { it.isReified() }
 
+
+        val annotations = if (config.descriptor.annotations.isEmpty()) {
+            ""
+        } else {
+            config.descriptor.annotations.joinToString(separator = "\n", postfix = "\n") { renderer.renderAnnotation(it) }
+        }
         val extraModifiers = config.descriptor.modifiers.map { it.value } +
                 listOfNotNull(if (shouldBeInline) KtTokens.INLINE_KEYWORD.value else null)
         val modifiers = if (visibility.isNotEmpty()) listOf(visibility) + extraModifiers else extraModifiers
-        modifier(modifiers.joinToString(separator = " "))
+        modifier(annotations + modifiers.joinToString(separator = " "))
 
         typeParams(
             config.descriptor.typeParameters.map {