[SLC] introduce SimpleAnnotationsBox

^KT-56046

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/annotations/AnnotationsBox.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2010-2023 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.light.classes.symbol.annotations
+
+import com.intellij.psi.PsiAnnotation
+import com.intellij.psi.PsiAnnotationOwner
+
+internal sealed interface AnnotationsBox : PsiAnnotationOwner {
+    override fun getApplicableAnnotations(): Array<PsiAnnotation> = annotations
+    override fun addAnnotation(qualifiedName: String): PsiAnnotation = throw UnsupportedOperationException()
+}

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/annotations/LazyAnnotationsBox.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.light.classes.symbol.annotations
 
 import com.intellij.psi.PsiAnnotation
-import com.intellij.psi.PsiAnnotationOwner
 import com.intellij.psi.PsiModifierList
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.StandardClassIds
@@ -17,7 +16,7 @@ internal class LazyAnnotationsBox(
     private val owner: PsiModifierList,
     private val annotationsProvider: AnnotationsProvider,
     private val additionalAnnotationsProvider: AdditionalAnnotationsProvider = DefaultAnnotationsProvider,
-) : PsiAnnotationOwner {
+) : AnnotationsBox {
     private val annotationsArray: AtomicReference<Array<PsiAnnotation>?> = AtomicReference()
     private var specialAnnotations: SmartList<PsiAnnotation>? = null
     private val monitor = Any()
@@ -61,8 +60,6 @@ internal class LazyAnnotationsBox(
             annotationsArray.get() ?: error("Unexpected state")
         }
 
-    override fun getApplicableAnnotations(): Array<PsiAnnotation> = annotations
-
     override fun findAnnotation(qualifiedName: String): PsiAnnotation? = findAnnotation(qualifiedName, withAdditionalAnnotations = true)
 
     fun findAnnotation(qualifiedName: String, withAdditionalAnnotations: Boolean): PsiAnnotation? {
@@ -124,8 +121,6 @@ internal class LazyAnnotationsBox(
         }
     }
 
-    override fun addAnnotation(qualifiedName: String): PsiAnnotation = throw UnsupportedOperationException()
-
     companion object {
         /**
          * @see org.jetbrains.kotlin.fir.resolve.transformers.plugin.CompilerRequiredAnnotationsHelper

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/annotations/SimpleAnnotationsBox.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2023 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.light.classes.symbol.annotations
+
+import com.intellij.psi.PsiAnnotation
+import org.jetbrains.kotlin.asJava.classes.lazyPub
+
+internal class SimpleAnnotationsBox(annotationsComputer: () -> Collection<PsiAnnotation>) : AnnotationsBox {
+    private val lazyAnnotation: Array<PsiAnnotation> by lazyPub {
+        val annotations = annotationsComputer()
+        if (annotations.isEmpty()) PsiAnnotation.EMPTY_ARRAY else annotations.toTypedArray()
+    }
+
+    override fun getAnnotations(): Array<PsiAnnotation> = lazyAnnotation
+    override fun findAnnotation(qualifiedName: String): PsiAnnotation? = lazyAnnotation.find { it.qualifiedName == qualifiedName }
+}