[FE 1.0] Support loading rxjava3 nullability annotations on bounded wildcards

^KT-53041 Fixed

core/compiler.common.jvm/src/org/jetbrains/kotlin/load/java/JavaNullabilityAnnotationSettings.kt

@@ -10,8 +10,16 @@ import org.jetbrains.kotlin.name.findValueForMostSpecificFqname
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
 
 val JSPECIFY_ANNOTATIONS_PACKAGE = FqName("org.jspecify.nullness")
+val RXJAVA3_ANNOTATIONS_PACKAGE = FqName("io.reactivex.rxjava3.annotations")
 val CHECKER_FRAMEWORK_COMPATQUAL_ANNOTATIONS_PACKAGE = FqName("org.checkerframework.checker.nullness.compatqual")
 
+private val RXJAVA3_ANNOTATIONS_PACKAGE_NAME = RXJAVA3_ANNOTATIONS_PACKAGE.asString()
+
+val RXJAVA3_ANNOTATIONS = arrayOf(
+    FqName("$RXJAVA3_ANNOTATIONS_PACKAGE_NAME.Nullable"),
+    FqName("$RXJAVA3_ANNOTATIONS_PACKAGE_NAME.NonNull")
+)
+
 val NULLABILITY_ANNOTATION_SETTINGS: NullabilityAnnotationStates<JavaNullabilityAnnotationsStatus> = NullabilityAnnotationStatesImpl(
     mapOf(
         FqName("org.jetbrains.annotations") to JavaNullabilityAnnotationsStatus.DEFAULT,
@@ -39,7 +47,7 @@ val NULLABILITY_ANNOTATION_SETTINGS: NullabilityAnnotationStates<JavaNullability
             sinceVersion = KotlinVersion(1, 9),
             reportLevelAfter = ReportLevel.STRICT
         ),
-        FqName("io.reactivex.rxjava3.annotations") to JavaNullabilityAnnotationsStatus(
+        RXJAVA3_ANNOTATIONS_PACKAGE to JavaNullabilityAnnotationsStatus(
             reportLevelBefore = ReportLevel.WARN,
             sinceVersion = KotlinVersion(1, 8),
             reportLevelAfter = ReportLevel.STRICT

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/types/JavaTypeResolver.kt

@@ -20,7 +20,7 @@ import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMapper
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
-import org.jetbrains.kotlin.types.TypeUsage
+import org.jetbrains.kotlin.load.java.extractNullabilityAnnotationOnBoundedWildcard
 import org.jetbrains.kotlin.types.TypeUsage.COMMON
 import org.jetbrains.kotlin.types.TypeUsage.SUPERTYPE
 import org.jetbrains.kotlin.load.java.lazy.LazyJavaAnnotations
@@ -287,8 +287,15 @@ class JavaTypeResolver(
                 if (bound == null || projectionKind.isConflictingArgumentFor(typeParameter))
                     makeStarProjection(typeParameter, attr)
                 else {
+                    val nullabilityAnnotationOnWildcard = extractNullabilityAnnotationOnBoundedWildcard(c, javaType)
+                    val transformedJavaType = transformJavaType(bound, COMMON.toAttributes()).let {
+                        if (nullabilityAnnotationOnWildcard != null) {
+                            it.replaceAnnotations(Annotations.create(it.annotations + nullabilityAnnotationOnWildcard))
+                        } else it
+                    }
+
                     createProjection(
-                        type = transformJavaType(bound, COMMON.toAttributes()),
+                        type = transformedJavaType,
                         projectionKind = projectionKind,
                         typeParameterDescriptor = typeParameter
                     )

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/utils.kt

@@ -18,7 +18,11 @@ package org.jetbrains.kotlin.load.java
 
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.load.java.descriptors.JavaMethodDescriptor
+import org.jetbrains.kotlin.load.java.lazy.LazyJavaAnnotations
+import org.jetbrains.kotlin.load.java.lazy.LazyJavaResolverContext
+import org.jetbrains.kotlin.load.java.structure.JavaWildcardType
 import org.jetbrains.kotlin.resolve.deprecation.DescriptorBasedDeprecationInfo
 import org.jetbrains.kotlin.resolve.deprecation.DeprecationLevelValue
 
@@ -36,3 +40,9 @@ fun isJspecifyEnabledInStrictMode(javaTypeEnhancementState: JavaTypeEnhancementS
 
 fun hasErasedValueParameters(memberDescriptor: CallableMemberDescriptor) =
     memberDescriptor is FunctionDescriptor && memberDescriptor.getUserData(JavaMethodDescriptor.HAS_ERASED_VALUE_PARAMETERS) == true
+
+// For now it's supported only for RxJava3 annotations, see KT-53041
+fun extractNullabilityAnnotationOnBoundedWildcard(c: LazyJavaResolverContext, wildcardType: JavaWildcardType): AnnotationDescriptor? {
+    require(wildcardType.bound != null) { "Nullability annotations on unbounded wildcards aren't supported" }
+    return LazyJavaAnnotations(c, wildcardType).find { annotation -> RXJAVA3_ANNOTATIONS.any { annotation.fqName == it } }
+}