FIR: Create DefinitelyNotNull only for annotated types

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancementSignatureParts.kt

@@ -15,12 +15,14 @@ import org.jetbrains.kotlin.fir.java.JavaTypeParameterStack
 import org.jetbrains.kotlin.fir.java.toConeKotlinTypeWithNullability
 import org.jetbrains.kotlin.fir.java.toFirJavaTypeRef
 import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
-import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
 import org.jetbrains.kotlin.load.java.MUTABLE_ANNOTATIONS
 import org.jetbrains.kotlin.load.java.READ_ONLY_ANNOTATIONS
+import org.jetbrains.kotlin.load.java.structure.JavaClassifierType
+import org.jetbrains.kotlin.load.java.structure.JavaTypeParameter
 import org.jetbrains.kotlin.load.java.structure.JavaWildcardType
 import org.jetbrains.kotlin.load.java.typeEnhancement.*
 import org.jetbrains.kotlin.name.ClassId
@@ -133,7 +135,7 @@ internal class EnhancementSignatureParts(
                 mapping.isMutable(upper.toFqNameUnsafe()) -> MutabilityQualifier.MUTABLE
                 else -> null
             },
-            isNotNullTypeParameter = false //TODO: unwrap() is NotNullTypeParameter
+            isNotNullTypeParameter = lower is ConeDefinitelyNotNullType
         )
     }
 
@@ -212,11 +214,14 @@ internal class EnhancementSignatureParts(
                     MutabilityQualifier.MUTABLE
                 )
             ),
-            isNotNullTypeParameter = nullabilityInfo?.qualifier == NullabilityQualifier.NOT_NULL && true, /* TODO: isTypeParameter()*/
+            isNotNullTypeParameter = nullabilityInfo?.qualifier == NullabilityQualifier.NOT_NULL && this.isTypeParameterBasedType(),
             isNullabilityQualifierForWarning = nullabilityInfo?.isForWarningOnly == true
         )
     }
 
+    private fun FirTypeRef?.isTypeParameterBasedType() =
+        ((this as? FirJavaTypeRef)?.type as? JavaClassifierType)?.classifier is JavaTypeParameter
+
     private fun FirTypeRef?.computeQualifiersForOverride(
         session: FirSession,
         fromSupertypes: Collection<FirTypeRef>,

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt

@@ -18,7 +18,6 @@ import org.jetbrains.kotlin.fir.java.declarations.FirJavaClass
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaField
 import org.jetbrains.kotlin.fir.java.toConeProjection
 import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
-import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.fir.references.impl.FirResolvedNamedReferenceImpl
 import org.jetbrains.kotlin.fir.references.impl.FirSimpleNamedReference
 import org.jetbrains.kotlin.fir.resolve.*
@@ -32,6 +31,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.typeContext
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.impl.FirResolvedTypeRefImpl
+import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.DEFAULT_NULL_FQ_NAME
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames.DEFAULT_VALUE_FQ_NAME
 import org.jetbrains.kotlin.load.java.descriptors.AnnotationDefaultValue
@@ -87,7 +87,9 @@ private fun JavaType?.enhancePossiblyFlexible(
 
             when {
                 type.isRaw -> ConeRawType(lowerResult, upperResult)
-                else -> coneFlexibleOrSimpleType(session, lowerResult, upperResult)
+                else -> coneFlexibleOrSimpleType(
+                    session, lowerResult, upperResult, isNotNullTypeParameter = qualifiers(index).isNotNullTypeParameter
+                )
             }
         }
         is JavaArrayType -> {
@@ -122,11 +124,12 @@ private fun JavaType?.subtreeSize(): Int {
 private fun coneFlexibleOrSimpleType(
     session: FirSession,
     lowerBound: ConeLookupTagBasedType,
-    upperBound: ConeLookupTagBasedType
+    upperBound: ConeLookupTagBasedType,
+    isNotNullTypeParameter: Boolean
 ): ConeKotlinType {
     if (AbstractStrictEqualityTypeChecker.strictEqualTypes(session.typeContext, lowerBound, upperBound)) {
         val lookupTag = lowerBound.lookupTag
-        if (lookupTag is ConeTypeParameterLookupTag && !lowerBound.isMarkedNullable) {
+        if (isNotNullTypeParameter && lookupTag is ConeTypeParameterLookupTag && !lowerBound.isMarkedNullable) {
             // TODO: we need enhancement for type parameter bounds for this code to work properly
             // At this moment, this condition is always true
             if (lookupTag.typeParameterSymbol.fir.bounds.any {