From 204c5952bf6b227406feaa51f47876cf5e1b8817 Mon Sep 17 00:00:00 2001
From: Jinseong Jeon <jsjeon@google.com>
Date: Fri, 3 Sep 2021 23:53:34 -0700
Subject: [PATCH] LC: avoid adding @null nullability annotations

---
 .../asJava/elements/KtLightModifierList.kt    |  3 +-
 .../asJava/elements/lightAnnotations.kt       | 32 ++++++++++---------
 2 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightModifierList.kt b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightModifierList.kt
index 6ea44313073..bb88a578d72 100644
--- a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightModifierList.kt
+++ b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightModifierList.kt
@@ -91,7 +91,8 @@ abstract class KtLightModifierList<out T : KtLightElement<KtModifierListOwner, P
                 else -> KtLightNullabilityAnnotation(modifierListOwner as KtLightElement<*, PsiModifierListOwner>, this)
             }
 
-            return annotationsForEntries + listOf(nullabilityAnnotation)
+            return annotationsForEntries +
+                    (if (nullabilityAnnotation.qualifiedName != null) listOf(nullabilityAnnotation) else emptyList())
         }
 
         return annotationsForEntries
diff --git a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/lightAnnotations.kt b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/lightAnnotations.kt
index d3108f633fd..b03362d49ed 100644
--- a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/lightAnnotations.kt
+++ b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/lightAnnotations.kt
@@ -277,52 +277,54 @@ open class KtLightNullabilityAnnotation<D : KtLightElement<*, PsiModifierListOwn
 
     override fun findAttributeValue(attributeName: String?): PsiAnnotationMemberValue? = null
 
-    override fun getQualifiedName(): String? {
+    private val _qualifiedName: String? by lazy {
         val annotatedElement = member.takeIf(::isFromSources)?.kotlinOrigin
             ?: // it is out of our hands
-            return getClsNullabilityAnnotation(member)?.qualifiedName
+            return@lazy getClsNullabilityAnnotation(member)?.qualifiedName
 
-        if (!fastCheckIsNullabilityApplied(member)) return null
+        if (!fastCheckIsNullabilityApplied(member)) return@lazy null
 
         // all data-class generated members are not-null
-        if (annotatedElement is KtClass && annotatedElement.isData()) return NotNull::class.java.name
+        if (annotatedElement is KtClass && annotatedElement.isData()) return@lazy NotNull::class.java.name
 
         // objects and companion objects have NotNull annotation (if annotated element is implicit ctor then skip annotation)
         if (annotatedElement is KtObjectDeclaration) {
-            if ((parent.parent as? PsiMethod)?.isConstructor == true) return null
-            return NotNull::class.java.name
+            if ((parent.parent as? PsiMethod)?.isConstructor == true) return@lazy null
+            return@lazy NotNull::class.java.name
         }
 
         // don't annotate property setters
-        if (annotatedElement is KtValVarKeywordOwner && member is KtLightMethod && member.returnType == PsiType.VOID) return null
+        if (annotatedElement is KtValVarKeywordOwner && member is KtLightMethod && member.returnType == PsiType.VOID) return@lazy null
 
         if (annotatedElement is KtNamedFunction && annotatedElement.modifierList?.hasSuspendModifier() == true) {
-            return Nullable::class.java.name
+            return@lazy Nullable::class.java.name
         }
 
-        val kotlinType = getTargetType(annotatedElement) ?: return null
+        val kotlinType = getTargetType(annotatedElement) ?: return@lazy null
 
         if (KotlinBuiltIns.isPrimitiveType(kotlinType) && (annotatedElement as? KtParameter)?.isVarArg != true) {
             // no need to annotate them explicitly except the case when overriding reference-type makes it non-primitive for Jvm
-            if (!(annotatedElement is KtCallableDeclaration && annotatedElement.hasModifier(KtTokens.OVERRIDE_KEYWORD))) return null
+            if (!(annotatedElement is KtCallableDeclaration && annotatedElement.hasModifier(KtTokens.OVERRIDE_KEYWORD))) return@lazy null
 
             val overriddenDescriptors =
                 (annotatedElement.analyze()[BindingContext.DECLARATION_TO_DESCRIPTOR, annotatedElement] as? CallableMemberDescriptor)?.overriddenDescriptors
-            if (overriddenDescriptors?.all { it.returnType == kotlinType } == true) return null
+            if (overriddenDescriptors?.all { it.returnType == kotlinType } == true) return@lazy null
         }
-        if (kotlinType.isUnit() && (annotatedElement !is KtValVarKeywordOwner)) return null // not annotate unit-functions
+        if (kotlinType.isUnit() && (annotatedElement !is KtValVarKeywordOwner)) return@lazy null // not annotate unit-functions
         if (kotlinType.isTypeParameter()) {
-            if (!TypeUtils.hasNullableSuperType(kotlinType)) return NotNull::class.java.name
-            if (!kotlinType.isMarkedNullable) return null
+            if (!TypeUtils.hasNullableSuperType(kotlinType)) return@lazy NotNull::class.java.name
+            if (!kotlinType.isMarkedNullable) return@lazy null
         }
 
-        return when (kotlinType.nullability()) {
+        when (kotlinType.nullability()) {
             TypeNullability.NOT_NULL -> NotNull::class.java.name
             TypeNullability.NULLABLE -> Nullable::class.java.name
             TypeNullability.FLEXIBLE -> null
         }
     }
 
+    override fun getQualifiedName(): String? = _qualifiedName
+
     internal fun KtTypeReference.getType(): KotlinType? = analyze()[BindingContext.TYPE, this]
 
     private fun getTargetType(annotatedElement: PsiElement): KotlinType? {