diff --git a/infer/src/bufferoverrun/absLoc.ml b/infer/src/bufferoverrun/absLoc.ml
index e985117d5..c9addeed8 100644
--- a/infer/src/bufferoverrun/absLoc.ml
+++ b/infer/src/bufferoverrun/absLoc.ml
@@ -61,7 +61,7 @@ module Allocsite = struct
 
   let is_pretty = function Symbol _ | Known {path= Some _} -> true | _ -> false
 
-  let is_literal_string = function LiteralString s -> Some s | _ -> None
+  let get_literal_string = function LiteralString s -> Some s | _ -> None
 
   let is_unknown = function Unknown -> true | Symbol _ | Known _ | LiteralString _ -> false
 
@@ -301,11 +301,11 @@ module Loc = struct
     match field_loc with Field {prefix= l} | StarField {prefix= l} -> equal loc l | _ -> false
 
 
-  let is_literal_string = function Allocsite a -> Allocsite.is_literal_string a | _ -> None
+  let get_literal_string = function Allocsite a -> Allocsite.get_literal_string a | _ -> None
 
-  let is_literal_string_strlen = function
+  let get_literal_string_strlen = function
     | Field {prefix= l; fn} when Typ.Fieldname.equal (BufferOverrunField.c_strlen ()) fn ->
-        is_literal_string l
+        get_literal_string l
     | _ ->
         None
 
diff --git a/infer/src/bufferoverrun/absLoc.mli b/infer/src/bufferoverrun/absLoc.mli
new file mode 100644
index 000000000..ee5e0f866
--- /dev/null
+++ b/infer/src/bufferoverrun/absLoc.mli
@@ -0,0 +1,150 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+
+open! IStd
+
+module Allocsite : sig
+  type t = private
+    | Unknown
+    | Symbol of Symb.SymbolPath.partial
+    | Known of
+        { proc_name: string
+        ; node_hash: int  (** hash of the node being allocated *)
+        ; inst_num: int  (** order of the instruction in the node, i.e. n-th instruction *)
+        ; dimension: int  (** depth of nested array *)
+        ; represents_multiple_values: bool
+        ; path: Symb.SymbolPath.partial option }
+    | LiteralString of string
+
+  include PrettyPrintable.PrintableOrderedType with type t := t
+
+  val to_string : t -> string
+
+  val unknown : t
+
+  val make :
+       Typ.Procname.t
+    -> node_hash:int
+    -> inst_num:int
+    -> dimension:int
+    -> path:Symb.SymbolPath.partial option
+    -> represents_multiple_values:bool
+    -> t
+
+  val make_symbol : Symb.SymbolPath.partial -> t
+
+  val literal_string : string -> t
+
+  val get_literal_string : t -> string option
+
+  val get_param_path : t -> Symb.SymbolPath.partial option
+
+  val eq : t -> t -> Boolean.t
+end
+
+module Loc : sig
+  type field_typ
+
+  type t = private
+    | Var of Var.t  (** abstract location of variable *)
+    | Allocsite of Allocsite.t  (** abstract location of allocsites *)
+    | Field of {prefix: t; fn: Typ.Fieldname.t; typ: field_typ}
+        (** field appended abstract locations, i.e., [prefix.fn] *)
+    | StarField of {prefix: t; last_field: Typ.Fieldname.t}
+        (** field appended abstract locations, but some of intermediate fields are abstracted, i.e.,
+            [prefix.*.fn] *)
+  [@@deriving equal]
+
+  include PrettyPrintable.PrintableOrderedType with type t := t
+
+  val to_string : t -> string
+
+  val of_allocsite : Allocsite.t -> t
+
+  val of_c_strlen : t -> t
+  (** It appends the [strlen] field. *)
+
+  val of_id : Ident.t -> t
+
+  val of_path : Symb.SymbolPath.partial -> t
+
+  val of_pvar : Pvar.t -> t
+
+  val of_var : Var.t -> t
+
+  val unknown : t
+
+  val exists_pvar : f:(Pvar.t -> bool) -> t -> bool
+  (** It checks if a pvar in location satisfies [f]. *)
+
+  val exists_str : f:(string -> bool) -> t -> bool
+  (** It checks if a variable or a field name in the location path satisfies [f]. *)
+
+  val get_literal_string : t -> string option
+
+  val get_literal_string_strlen : t -> string option
+
+  val get_path : t -> Symb.SymbolPath.partial option
+
+  val is_field_of : loc:t -> field_loc:t -> bool
+  (** It checks if [loc] is prefix of [field_loc]. *)
+
+  val is_frontend_tmp : t -> bool
+
+  val is_global : t -> bool
+
+  val is_pretty : t -> bool
+  (** It checks if it is representable with pretty form, e.g., with a path or with a variable
+     name. *)
+
+  val is_return : t -> bool
+
+  val is_unknown : t -> bool
+
+  val represents_multiple_values : t -> bool
+
+  val append_field : ?typ:Typ.typ -> t -> fn:Typ.Fieldname.t -> t
+  (** It appends field. [typ] is the type of [fn]. *)
+end
+
+module PowLoc : sig
+  include AbstractDomain.FiniteSetS with type elt = Loc.t
+
+  val append_field : t -> fn:Typ.Fieldname.t -> t
+
+  val append_star_field : t -> fn:Typ.Fieldname.t -> t
+
+  val bot : t
+
+  val cast : Typ.typ -> t -> t
+
+  val of_c_strlen : t -> t
+  (** It appends the [strlen] field. *)
+
+  val unknown : t
+
+  val exists_str : f:(string -> bool) -> t -> bool
+  (** It checks if a variable or a field name in the location path satisfies [f]. *)
+
+  val is_bot : t -> bool
+
+  (** Type for evaluating a path to an abstract location. *)
+  type eval_locpath = Symb.SymbolPath.partial -> t
+
+  val subst : t -> eval_locpath -> t
+  (** It substitutes paths in the abstract location using [eval_locpath]. *)
+
+  val subst_loc : Loc.t -> eval_locpath -> t
+  (** It substitutes paths in the abstract location using [eval_locpath]. *)
+
+  val lift_cmp : Boolean.EqualOrder.t -> t -> t -> Boolean.t
+  (** It lifts a comparison of [Loc.t] to [t].  The comparison can be [Boolean.EqualOrder.eq],
+     [Boolean.EqualOrder.ne], etc. *)
+end
+
+val can_strong_update : PowLoc.t -> bool
+(** It checks if the abstract location can be updated strongly. *)
diff --git a/infer/src/bufferoverrun/bufferOverrunAnalysis.ml b/infer/src/bufferoverrun/bufferOverrunAnalysis.ml
index 6e0a7c13b..a70b9c246 100644
--- a/infer/src/bufferoverrun/bufferOverrunAnalysis.ml
+++ b/infer/src/bufferoverrun/bufferOverrunAnalysis.ml
@@ -12,6 +12,7 @@ open AbsLoc
 open! AbstractDomain.Types
 module BoUtils = BufferOverrunUtils
 module Dom = BufferOverrunDomain
+module F = Format
 module L = Logging
 module Models = BufferOverrunModels
 module Sem = BufferOverrunSemantics
diff --git a/infer/src/bufferoverrun/bufferOverrunChecker.ml b/infer/src/bufferoverrun/bufferOverrunChecker.ml
index dda8c5c62..e987ee0d3 100644
--- a/infer/src/bufferoverrun/bufferOverrunChecker.ml
+++ b/infer/src/bufferoverrun/bufferOverrunChecker.ml
@@ -8,11 +8,11 @@
  *)
 
 open! IStd
-open AbsLoc
 open! AbstractDomain.Types
 module BoUtils = BufferOverrunUtils
 module CFG = BufferOverrunAnalysis.CFG
 module Dom = BufferOverrunDomain
+module F = Format
 module L = Logging
 module Models = BufferOverrunModels
 module PO = BufferOverrunProofObligations
diff --git a/infer/src/bufferoverrun/bufferOverrunDomain.ml b/infer/src/bufferoverrun/bufferOverrunDomain.ml
index 7f426d992..8b0dc9452 100644
--- a/infer/src/bufferoverrun/bufferOverrunDomain.ml
+++ b/infer/src/bufferoverrun/bufferOverrunDomain.ml
@@ -653,11 +653,11 @@ module Val = struct
       let may_last_field = may_last_field path in
       of_path tenv ~may_last_field integer_type_widths entry_location typ path
     in
-    match Loc.is_literal_string l with
+    match Loc.get_literal_string l with
     | Some s ->
         deref_of_literal_string s
     | None -> (
-      match Loc.is_literal_string_strlen l with
+      match Loc.get_literal_string_strlen l with
       | Some s ->
           of_itv (Itv.of_int (String.length s))
       | None -> (