[Infer][bucketing] Moving warnings on dereferences of @Nullable params from B5 -> B1,

infer/src/backend/buckets.ml

@@ -101,9 +101,9 @@ let check_access access_opt =
       Some Localise.BucketLevel.b1
   | _ -> None
 
-let classify_access desc access_opt =
-  L.d_strln "Doing classification";
+let classify_access desc access_opt is_nullable =
+  let default_bucket = if is_nullable then Localise.BucketLevel.b1 else Localise.BucketLevel.b5 in
   let show_in_message = !Config.show_buckets in
   match check_access access_opt with
-  | None -> Localise.error_desc_set_bucket desc Localise.BucketLevel.b5 show_in_message
+  | None -> Localise.error_desc_set_bucket desc default_bucket show_in_message
   | Some bucket -> Localise.error_desc_set_bucket desc bucket show_in_message

infer/src/backend/buckets.mli

@@ -8,5 +8,5 @@
 
 open Utils
 
-(** Classify the bucket of an error desc using Location.access information *)
-val classify_access : Localise.error_desc -> Localise.access option -> Localise.error_desc
+(** Classify the bucket of an error desc using Location.access and nullable information *)
+val classify_access : Localise.error_desc -> Localise.access option -> bool -> Localise.error_desc

infer/src/backend/errdesc.ml

@@ -749,7 +749,7 @@ let create_dereference_desc
             | _ -> desc)
       | _ -> desc
     else desc in
-  if use_buckets then Buckets.classify_access desc access_opt'
+  if use_buckets then Buckets.classify_access desc access_opt' is_nullable
   else desc
 
 (** explain memory access performed by the current instruction