KT-12303 Pass only relevant annotations to annotation processors

(cherry picked from commit 01742aa)

libraries/tools/kotlin-annotation-processing/src/main/kotlin/org/jetbrains/kotlin/annotation/AnnotationProcessorWrapper.kt

@@ -26,11 +26,11 @@ import javax.lang.model.element.TypeElement
 import javax.tools.Diagnostic
 import kotlin.properties.Delegates
 
-public class AnnotationProcessorStub : AbstractProcessor() {
+class AnnotationProcessorStub : AbstractProcessor() {
     override fun process(annotations: Set<TypeElement>?, roundEnv: RoundEnvironment?) = true
 }
 
-public abstract class AnnotationProcessorWrapper(
+abstract class AnnotationProcessorWrapper(
         private val processorFqName: String,
         private val taskQualifier: String
 ) : Processor {
@@ -38,6 +38,13 @@ public abstract class AnnotationProcessorWrapper(
     private companion object {
         val KAPT_ANNOTATION_OPTION = "kapt.annotations"
         val KAPT_KOTLIN_GENERATED_OPTION = "kapt.kotlin.generated"
+
+        /*
+        * If no Java sources are provided, javac finishes without running Annotation Processing.
+        * This is not what we want, so we generate a special class for this case
+        * with a field annotated with KAPT_SPECIAL_ANNOTATION (see AnnotationProcessingManager.generateJavaHackFile).
+        */
+        val KAPT_SPECIAL_ANNOTATION = "__gen.KotlinAptAnnotation"
     }
 
     private val processor: Processor by lazy {
@@ -56,6 +63,8 @@ public abstract class AnnotationProcessorWrapper(
 
     private var roundCounter = 0
 
+    private var handledAnnotationTypes: Set<String> = emptySet()
+
     override fun getCompletions(
             element: Element?,
             annotation: AnnotationMirror?,
@@ -83,11 +92,13 @@ public abstract class AnnotationProcessorWrapper(
         }
 
         processor.init(processingEnv)
+
+        handledAnnotationTypes = this.supportedAnnotationTypes
     }
 
     override fun getSupportedAnnotationTypes(): MutableSet<String> {
         val supportedAnnotations = processor.supportedAnnotationTypes.toMutableSet()
-        supportedAnnotations.add("__gen.KotlinAptAnnotation")
+        supportedAnnotations.add(KAPT_SPECIAL_ANNOTATION)
         return supportedAnnotations
     }
 
@@ -106,7 +117,10 @@ public abstract class AnnotationProcessorWrapper(
 
         if (roundCounter == 1) {
             for (annotationFqName in kotlinAnnotationsProvider.annotatedKotlinElements.keys) {
-                if (annotationFqName in existingFqNames) continue
+                if (annotationFqName in existingFqNames
+                        || annotationFqName == KAPT_SPECIAL_ANNOTATION
+                        || annotationFqName !in handledAnnotationTypes // Filter out irrelevant annotations) continue
+                ) continue
                 existingFqNames.add(annotationFqName)
                 processingEnv.elementUtils.getTypeElement(annotationFqName)?.let { wrappedAnnotations += it }
             }