unifying checking of temporary variables

Reviewed By: jeremydubreil

Differential Revision: D3473066

fbshipit-source-id: 871b878

infer/src/IR/Pvar.re

@@ -260,6 +260,26 @@ let is_this pvar => Mangled.equal (get_name pvar) (Mangled.from_string "this");
 let is_return pv => get_name pv == Ident.name_return;
 
 
+/** return true if [pvar] is a temporary variable generated by the frontend */
+let is_frontend_tmp pvar => {
+  /* Check whether the program variable is a temporary one generated by the Clang frontend */
+  let is_clang_tmp name => string_is_prefix "_tmp" name;
+  /* Check whether the program variable is a temporary one generated by sawja */
+  let is_sawja_tmp name =>
+    string_is_prefix "$irvar" name || string_is_prefix "$T" name || string_is_prefix "$bc" name;
+  let name = to_string pvar;
+  switch pvar.pv_kind {
+  | Local_var pname =>
+    if (Procname.is_java pname) {
+      is_sawja_tmp name
+    } else {
+      is_clang_tmp name
+    }
+  | _ => false
+  }
+};
+
+
 /** Turn an ordinary program variable into a callee program variable */
 let to_callee pname pvar =>
   switch pvar.pv_kind {

infer/src/IR/Pvar.rei

@@ -83,6 +83,10 @@ let is_return: t => bool;
 let is_this: t => bool;
 
 
+/** return true if [pvar] is a temporary variable generated by the frontend */
+let is_frontend_tmp: t => bool;
+
+
 /** [mk name proc_name suffix] creates a program var with the given function name and suffix */
 let mk: Mangled.t => Procname.t => t;
 

infer/src/backend/errdesc.ml

@@ -194,25 +194,6 @@ let rec find_boolean_assignment node pvar true_branch : Cfg.Node.t option =
       else None
   | _ -> None
 
-(** Check whether the program variable is a temporary one generated by CIL *)
-let pvar_is_cil_tmp pvar =
-  Pvar.is_local pvar &&
-  let name = Pvar.to_string pvar in
-  string_is_prefix "_tmp" name
-
-(** Check whether the program variable is a temporary one generated by sawja *)
-let pvar_is_sawja_tmp pvar =
-  Pvar.is_local pvar &&
-  let name = Pvar.to_string pvar in
-  string_is_prefix "$irvar" name ||
-  string_is_prefix "$T" name ||
-  string_is_prefix "$bc" name
-
-(** Check whether the program variable is a temporary generated by the front-end *)
-let pvar_is_frontend_tmp pvar =
-  if !Config.curr_language = Config.Java then pvar_is_sawja_tmp pvar
-  else pvar_is_cil_tmp pvar
-
 (** Find the Letderef instruction used to declare normal variable [id],
     and return the expression dereferenced to initialize [id] *)
 let rec _find_normal_variable_letderef (seen : Sil.ExpSet.t) node id : Sil.dexp option =
@@ -288,7 +269,7 @@ and _exp_lv_dexp (_seen : Sil.ExpSet.t) node e : Sil.dexp option =
          | Some de -> Some (Sil.Dderef de))
     | Sil.Lvar pvar ->
         if verbose then (L.d_str "exp_lv_dexp: program var "; Sil.d_exp e; L.d_ln ());
-        if pvar_is_frontend_tmp pvar then
+        if Pvar.is_frontend_tmp pvar then
           begin
             match find_program_variable_assignment node pvar with
             | None -> None
@@ -361,7 +342,7 @@ and _exp_rv_dexp (_seen : Sil.ExpSet.t) node e : Sil.dexp option =
         Some (Sil.Dconst c)
     | Sil.Lvar pv ->
         if verbose then (L.d_str "exp_rv_dexp: program var "; Sil.d_exp e; L.d_ln ());
-        if pvar_is_frontend_tmp pv
+        if Pvar.is_frontend_tmp pv
         then _exp_lv_dexp _seen (* avoid spurious cycle detection *) node e
         else Some (Sil.Dpvaraddr pv)
     | Sil.Var id when Ident.is_normal id ->
@@ -510,7 +491,7 @@ let explain_leak tenv hpred prop alloc_att_opt bucket =
   let check_pvar pvar =
     (* check that pvar is local or global and has the same type as the leaked hpred *)
     (Pvar.is_local pvar || Pvar.is_global pvar) &&
-    not (pvar_is_frontend_tmp pvar) &&
+    not (Pvar.is_frontend_tmp pvar) &&
     match hpred_typ_opt, find_typ_without_ptr prop pvar with
     | Some (Sil.Sizeof (t1, _, _)), Some (Sil.Sizeof (Typ.Tptr (t2_, _), _, _)) ->
         (try
@@ -545,7 +526,7 @@ let explain_leak tenv hpred prop alloc_att_opt bucket =
           | _ -> [] in
         let nullify_pvars = IList.flatten (IList.map get_nullify node_instrs) in
         let nullify_pvars_notmp =
-          IList.filter (fun pvar -> not (pvar_is_frontend_tmp pvar)) nullify_pvars in
+          IList.filter (fun pvar -> not (Pvar.is_frontend_tmp pvar)) nullify_pvars in
         value_str_from_pvars_vpath nullify_pvars_notmp vpath
     | Some (Sil.Set (lexp, _, _, _)) when vpath = None ->
         if verbose
@@ -609,7 +590,7 @@ let vpath_find prop _exp : Sil.dexp option * Typ.t option =
       | Sil.Eexp (e, _) when Sil.exp_equal exp e ->
           let sigma' = (IList.rev_append sigma_acc' sigma_todo') in
           (match lexp with
-           | Sil.Lvar pv when not (pvar_is_frontend_tmp pv) ->
+           | Sil.Lvar pv when not (Pvar.is_frontend_tmp pv) ->
                let typo = match texp with
                  | Sil.Sizeof (typ, _, _) -> Some typ
                  | _ -> None in

infer/src/backend/errdesc.mli

@@ -130,12 +130,6 @@ val explain_memory_access : Localise.deref_str -> 'a Prop.t -> Location.t -> Loc
 val explain_null_test_after_dereference :
   Sil.exp -> Cfg.Node.t -> int -> Location.t -> Localise.error_desc
 
-(** Check whether the program variable is a temporary one generated by CIL *)
-val pvar_is_cil_tmp : Pvar.t -> bool
-
-(** Check whether the program variable is a temporary generated by the front-end *)
-val pvar_is_frontend_tmp : Pvar.t -> bool
-
 (** Print a warning to the err stream at the given location (note: only prints in developer mode) *)
 val warning_err : Location.t -> ('a, Format.formatter, unit) format -> 'a
 

infer/src/backend/interproc.ml

@@ -384,10 +384,10 @@ let check_assignement_guard node =
     match i with
     | Sil.Letderef _ -> true
     | _ -> false in
-  let is_cil_tmp e =
+  let is_frontend_tmp e =
     match e with
     | Sil.Lvar pv ->
-        Errdesc.pvar_is_cil_tmp pv
+        Pvar.is_frontend_tmp pv
     | _ -> false in
   let succs = Cfg.Node.get_succs node in
   let l_node = Cfg.Node.get_last_loc node in
@@ -453,7 +453,7 @@ let check_assignement_guard node =
          (match set_instr_at_succs_loc with
           | [Sil.Set(e, _, _, _)] ->
               (* we now check if e is the same expression used to prune*)
-              if (is_prune_exp e) && not ((node_contains_call node) && (is_cil_tmp e)) then (
+              if (is_prune_exp e) && not ((node_contains_call node) && (is_frontend_tmp e)) then (
                 let desc = Errdesc.explain_condition_is_assignment l_node in
                 let exn = Exceptions.Condition_is_assignment (desc, __POS__) in
                 let pre_opt = State.get_normalized_pre (Abs.abstract_no_symop pname) in

infer/src/checkers/idenv.ml

@@ -50,7 +50,7 @@ let expand_expr idenv e = match e with
 let expand_expr_temps idenv node _exp =
   let exp = expand_expr idenv _exp in
   match exp with
-  | Sil.Lvar pvar when Errdesc.pvar_is_frontend_tmp pvar ->
+  | Sil.Lvar pvar when Pvar.is_frontend_tmp pvar ->
       (match Errdesc.find_program_variable_assignment node pvar with
        | None -> exp
        | Some (_, id) ->
@@ -61,5 +61,5 @@ let expand_expr_temps idenv node _exp =
 let exp_is_temp idenv e =
   match expand_expr idenv e with
   | Sil.Lvar pvar ->
-      Errdesc.pvar_is_frontend_tmp pvar
+      Pvar.is_frontend_tmp pvar
   | _ -> false

infer/src/checkers/repeatedCallsChecker.ml

@@ -113,7 +113,7 @@ struct
       let filter_arg (e, _) = match e with
         | Sil.Lvar pvar ->
             (* same temporary variable does not imply same value *)
-            not (Errdesc.pvar_is_frontend_tmp pvar)
+            not (Pvar.is_frontend_tmp pvar)
         | _ -> true in
       IList.for_all filter_arg args in
 

infer/src/eradicate/typeCheck.ml

@@ -117,7 +117,7 @@ module ComplexExpressions = struct
       | Sil.Dretcall _ ->
           case_not_handled ()
       | Sil.Dpvar pv
-      | Sil.Dpvaraddr pv when not (Errdesc.pvar_is_frontend_tmp pv) ->
+      | Sil.Dpvaraddr pv when not (Pvar.is_frontend_tmp pv) ->
           Pvar.to_string pv
       | Sil.Dpvar _
       | Sil.Dpvaraddr _ (* front-end variable -- this should not happen) *) ->
@@ -328,8 +328,7 @@ let typecheck_instr
         Errdesc.find_normal_variable_funcall node' id <> None ->
         handle_function_call node' id
     | Sil.Lvar pvar when
-        ComplexExpressions.functions_idempotent () &&
-        Errdesc.pvar_is_frontend_tmp pvar ->
+        ComplexExpressions.functions_idempotent () && Pvar.is_frontend_tmp pvar ->
         let frontend_variable_assignment =
           Errdesc.find_program_variable_assignment node pvar in
         begin
@@ -441,7 +440,7 @@ let typecheck_instr
     let typestate' = handle_pvar typestate pvar in
     let curr_node = TypeErr.InstrRef.get_node instr_ref in
     let frontent_variable_assignment =
-      if Errdesc.pvar_is_frontend_tmp pvar
+      if Pvar.is_frontend_tmp pvar
       then Errdesc.find_program_variable_assignment curr_node pvar
       else None in
     match frontent_variable_assignment with
@@ -1058,7 +1057,7 @@ let typecheck_instr
             let c' = Idenv.expand_expr idenv _cond in
             if not (Sil.exp_equal c' _cond) then normalize_cond _node c'
             else _node, c'
-        | Sil.Lvar pvar when Errdesc.pvar_is_frontend_tmp pvar ->
+        | Sil.Lvar pvar when Pvar.is_frontend_tmp pvar ->
             (match handle_assignment_in_condition pvar with
              | None ->
                  (match Errdesc.find_program_variable_assignment _node pvar with