[IR] More detailed type for Fieldname.t

Summary:
Split Fieldname.t into `Java` and `Clang`. Each of them have different naming conventions and this way it's easier to differentiate between them.
Make `Java` variant store string instead of mangled since mangled part was always empty
Changes to `Clang` variant are coming in the next diff

Reviewed By: jeremydubreil

Differential Revision: D4746708

fbshipit-source-id: c5858a8

infer/src/IR/Fieldname.re

@@ -10,7 +10,13 @@ open! IStd;
 
 let module Hashtbl = Caml.Hashtbl;
 
-type t = {fpos: int, fname: Mangled.t} [@@deriving compare];
+type t =
+  | Hidden /* Backend relies that Hidden is the smallest (first) field in Abs.should_raise_objc_leak */
+  | Clang Mangled.t
+  | Java string
+[@@deriving compare];
+
+let hidden_str = ".hidden";
 
 let equal = [%compare.equal : t];
 
@@ -24,22 +30,38 @@ let module Map = Caml.Map.Make {
   let compare = compare;
 };
 
+let module Clang = {
+
+  /** Create a field name with the given position (field number in the CSU) */
+  let create (n: Mangled.t) => Clang n;
+};
+
+let module Java = {
 
-/** Create a field name with the given position (field number in the CSU) */
-let create (n: Mangled.t) (position: int) => {fpos: position, fname: n};
+  /** Create a field name with the given position (field number in the CSU) */
+  let from_string n => Java n;
+};
 
 
 /** Convert a fieldname to a string. */
-let to_string fn => Mangled.to_string fn.fname;
+let to_string =
+  fun
+  | Hidden => hidden_str
+  | Java fname => fname
+  | Clang fname => Mangled.to_string fname;
 
 
 /** Convert a fieldname to a string, including the mangled part. */
-let to_complete_string fn => Mangled.to_string_full fn.fname;
+let to_complete_string =
+  fun
+  | Hidden => hidden_str
+  | Java fname => fname
+  | Clang fname => Mangled.to_string_full fname;
 
 
 /** Convert a fieldname to a simplified string with at most one-level path. */
 let to_simplified_string fn => {
-  let s = Mangled.to_string fn.fname;
+  let s = to_string fn;
   switch (String.rsplit2 s on::'.') {
   | Some (s1, s2) =>
     switch (String.rsplit2 s1 on::'.') {
@@ -53,18 +75,20 @@ let to_simplified_string fn => {
 
 /** Convert a fieldname to a flat string without path. */
 let to_flat_string fn => {
-  let s = Mangled.to_string fn.fname;
+  let s = to_string fn;
   switch (String.rsplit2 s on::'.') {
   | Some (_, s2) => s2
   | _ => s
   }
 };
 
-let pp f fn =>
-  /* only use for debug F.fprintf f "%a#%d" pp_name fn.fname fn.fpos */
-  Mangled.pp f fn.fname;
+let pp f =>
+  fun
+  | Hidden => Format.fprintf f "%s" hidden_str
+  | Java fname => Format.fprintf f "%s" fname
+  | Clang fname => Mangled.pp f fname;
 
-let pp_latex style f fn => Latex.pp_string style f (Mangled.to_string fn.fname);
+let pp_latex style f fn => Latex.pp_string style f (to_string fn);
 
 
 /** Returns the class part of the fieldname */
@@ -95,11 +119,9 @@ let java_is_outer_instance fn => {
   }
 };
 
-let fieldname_offset fn => fn.fpos;
-
 
 /** hidded fieldname constant */
-let hidden = create (Mangled.from_string ".hidden") 0;
+let hidden = Hidden;
 
 
 /** hidded fieldname constant */

infer/src/IR/Fieldname.rei

@@ -24,9 +24,17 @@ let module Set: Caml.Set.S with type elt = t;
 /** Map for fieldnames */
 let module Map: Caml.Map.S with type key = t;
 
+let module Clang: {
 
-/** Create a field name at the given position */
-let create: Mangled.t => int => t;
+  /** Create a clang field name */
+  let create: Mangled.t => t;
+};
+
+let module Java: {
+
+  /** Create a java field name */
+  let from_string: string => t;
+};
 
 
 /** Convert a field name to a string. */

infer/src/backend/prover.ml

@@ -1972,7 +1972,7 @@ and sigma_imply tenv calc_index_frame calc_missing subs prop1 sigma2 : (subst2 *
             (Exp.int len, [(index, Sil.Eexp (Exp.zero, Sil.inst_none))], Sil.inst_none)
       | Config.Java ->
           let mk_fld_sexp s =
-            let fld = Fieldname.create (Mangled.from_string s) 0 in
+            let fld = Fieldname.Java.from_string s in
             let se = Sil.Eexp (Exp.Var (Ident.create_fresh Ident.kprimed), Sil.Inone) in
             (fld, se) in
           let fields = ["java.lang.String.count"; "java.lang.String.hash"; "java.lang.String.offset"; "java.lang.String.value"] in
@@ -1989,7 +1989,7 @@ and sigma_imply tenv calc_index_frame calc_missing subs prop1 sigma2 : (subst2 *
     let root = Exp.Const (Const.Cclass (Ident.string_to_name s)) in
     let sexp = (* TODO: add appropriate fields *)
       Sil.Estruct
-        ([(Fieldname.create (Mangled.from_string "java.lang.Class.name") 0,
+        ([(Fieldname.Java.from_string "java.lang.Class.name",
            Sil.Eexp ((Exp.Const (Const.Cstr s), Sil.Inone)))], Sil.inst_none) in
     let class_texp =
       let class_type = Typ.Name.Java.from_string "java.lang.Class" in

infer/src/checkers/ThreadSafety.ml

@@ -324,9 +324,8 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
           (* create a dummy write that represents mutating the contents of the container *)
           let open Domain in
           let dummy_fieldname =
-            Fieldname.create
-              (Mangled.from_string
-                 (container_write_string ^ (Typ.Procname.get_method callee_pname))) 0 in
+            Fieldname.Java.from_string
+              (container_write_string ^ (Typ.Procname.get_method callee_pname)) in
           let dummy_access_exp = Exp.Lfield (receiver_exp, dummy_fieldname, receiver_typ) in
           let callee_accesses =
             match AccessPath.of_lhs_exp dummy_access_exp receiver_typ ~f_resolve_id with

infer/src/clang/cGeneral_utils.ml

@@ -102,7 +102,7 @@ let replicate n el = List.map ~f:(fun _ -> el) (list_range 0 (n -1))
 let mk_class_field_name field_qual_name =
   let field_name = field_qual_name.Clang_ast_t.ni_name in
   let class_name = CAst_utils.get_class_name_from_member field_qual_name in
-  Fieldname.create (Mangled.mangled field_name class_name) 0
+  Fieldname.Clang.create (Mangled.mangled field_name class_name)
 
 let is_cpp_translation translation_unit_context =
   let lang = translation_unit_context.CFrontend_config.lang in

infer/src/eradicate/typeCheck.ml

@@ -221,9 +221,7 @@ let rec typecheck_expr
         match EradicateChecks.explain_expr tenv node index_exp with
         | Some s -> s
         | None -> "?" in
-      let fname = Fieldname.create
-          (Mangled.from_string index)
-          0 in
+      let fname = Fieldname.Java.from_string index in
       if checks.eradicate then
         EradicateChecks.check_array_access tenv
           find_canonical_duplicate
@@ -560,7 +558,7 @@ let typecheck_instr
           node
           instr_ref
           array_exp
-          (Fieldname.create (Mangled.from_string "length") 0)
+          (Fieldname.Java.from_string "length")
           ta
           loc
           false;

infer/src/java/jTransType.ml

@@ -205,11 +205,9 @@ let translate_method_name m =
 
 
 let fieldname_create cn fs =
-  let fieldname cn fs =
   let fieldname = (JBasics.fs_name fs) in
   let classname = (JBasics.cn_name cn) in
-    Mangled.from_string (classname^"."^fieldname) in
-  Fieldname.create (fieldname cn fs) 0
+  Fieldname.Java.from_string (classname^"."^fieldname)
 
 let create_sil_class_field cn cf =
   let fs = cf.Javalib.cf_signature in

infer/src/unit/accessPathTestUtils.ml

@@ -15,8 +15,7 @@ let make_var var_str =
 let make_base ?(typ=Typ.Tvoid) base_str =
   AccessPath.base_of_pvar (make_var base_str) typ
 
-let make_fieldname fld_str =
-  Fieldname.create (Mangled.from_string fld_str) 0
+let make_fieldname = Fieldname.Java.from_string
 
 let make_field_access access_str =
   AccessPath.FieldAccess (make_fieldname access_str)