[uninit] convert to HIL

Summary: This will make it easier to generalize the checker to handling uninitialized struct fields.

Reviewed By: ddino

Differential Revision: D6099484

fbshipit-source-id: b9c534b

infer/src/checkers/uninit.ml

@@ -30,11 +30,75 @@ end)
 
 let intraprocedural_only = true
 
+module TransferFunctions (CFG : ProcCfg.S) = struct
+  module CFG = CFG
+  module Domain = RecordDomain
+
+  type extras = FormalMap.t
+
+  let exec_instr (astate: Domain.astate) {ProcData.extras} _ (instr: HilInstr.t) =
+    match instr with
+    | Assign (((lhs_var, _), _), HilExp.AccessPath ((rhs_var, rhs_typ as rhs_base), _), _)
+     -> let uninit_vars = D.remove lhs_var astate.uninit_vars in
+        let prepost =
+          if FormalMap.is_formal rhs_base extras
+             && match rhs_typ.desc with Typ.Tptr _ -> true | _ -> false
+          then
+            let pre' = D.add rhs_var (fst astate.prepost) in
+            let post = snd astate.prepost in
+            (pre', post)
+          else astate.prepost
+        in
+        {astate with uninit_vars; prepost}
+    | Assign (((lhs_var, _), _), _, _)
+     -> let uninit_vars = D.remove lhs_var astate.uninit_vars in
+        {astate with uninit_vars}
+    | Call (_, _, actuals, _, _)
+     -> (* in case of intraprocedural only analysis we assume that parameters passed by reference
+           to a function will be initialized inside that function *)
+        let uninit_vars =
+          List.fold
+            ~f:(fun acc actual_exp ->
+              match actual_exp with
+              | HilExp.AccessPath ((actual_var, {Typ.desc= Tptr _}), _)
+               -> D.remove actual_var acc
+              | _
+               -> acc)
+            ~init:astate.uninit_vars actuals
+        in
+        {astate with uninit_vars}
+    | Assume _
+     -> astate
+end
+
+module CFG = ProcCfg.OneInstrPerNode (ProcCfg.Normal)
+module Analyzer = AbstractInterpreter.Make (CFG) (LowerHil.MakeDefault (TransferFunctions))
+
+let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
+  let cfg = CFG.from_pdesc proc_desc in
+  (* start with empty set of uninit local vars and  empty set of init formal params *)
+  let formal_map = FormalMap.make proc_desc in
+  let uninit_vars =
+    List.map
+      ~f:(fun (name, _) ->
+        let pvar = Pvar.mk name (Procdesc.get_proc_name proc_desc) in
+        Var.of_pvar pvar)
+      (Procdesc.get_locals cfg)
+  in
+  let init =
+    ( { RecordDomain.uninit_vars= UninitVars.of_list uninit_vars
+      ; RecordDomain.aliased_vars= AliasedVars.empty
+      ; RecordDomain.prepost= (D.empty, D.empty) }
+    , IdAccessPathMapDomain.empty )
+  in
+  let invariant_map =
+    Analyzer.exec_cfg cfg (ProcData.make proc_desc tenv formal_map) ~initial:init ~debug:true
+  in
   (* Check if an expression is in set of variables *)
   let exp_in_set exp vset =
     let _, pvars = Exp.get_vars exp in
     List.exists ~f:(fun pv -> D.mem (Var.of_pvar pv) vset) pvars
-
+  in
   let zip_actual_formal_params callee_pname actual_params =
     match Ondemand.get_proc_desc callee_pname with
     | Some pdesc
@@ -43,7 +107,7 @@ let zip_actual_formal_params callee_pname actual_params =
         (List.zip actual formals, actual)
     | _
      -> (None, [])
-
+  in
   let deref_actual_params callee_pname actual_params deref_formal_params =
     match zip_actual_formal_params callee_pname actual_params with
     | None, _
@@ -54,149 +118,6 @@ let deref_actual_params callee_pname actual_params deref_formal_params =
             let fe = Exp.Lvar (Pvar.mk f callee_pname) in
             if exp_in_set fe deref_formal_params then a :: acc else acc)
           ~init:[] assoc_actual_formal
-
-module TransferFunctions (CFG : ProcCfg.S) = struct
-  module CFG = CFG
-  (*  a state is a pair: ({set of uninitialized locals}, {set of written formal params})  *)
-  (*  module Domain = AbstractDomain.Pair (UninitVars) (PrePost)*)
-  module Domain = RecordDomain
-
-  type extras = ProcData.no_extras
-
-  let apply_fun_exp_set f exp vset =
-    let _, pvars = Exp.get_vars exp in
-    List.fold ~f:(fun acc_set pvar -> f (Var.of_pvar pvar) acc_set) ~init:vset pvars
-
-  let exp_add_set exp vset = apply_fun_exp_set D.add exp vset
-
-  let exp_remove_set exp vset = apply_fun_exp_set D.remove exp vset
-
-  let set_difference set1 set2 =
-    List.fold ~f:(fun acc_set e -> exp_remove_set e acc_set) ~init:set1 set2
-
-  (* check if its a basic type *)
-  let rec is_basic_typ t =
-    match t.Typ.desc with
-    | Typ.Tint _ | Typ.Tfloat _ | Typ.Tvoid
-     -> true
-    | Typ.Tptr (t', _)
-     -> is_basic_typ t'
-    | _
-     -> false
-
-  (* returns the formal parameter of a procedure that have a pointer type *)
-  let ptr_formals pdesc =
-    let proc_name = Procdesc.get_proc_name pdesc in
-    let is_ptr (_, t) = match t.Typ.desc with Typ.Tptr _ -> true | _ -> false in
-    let pfs = List.filter ~f:is_ptr (Procdesc.get_formals pdesc) in
-    List.map ~f:(fun (name, _) -> Exp.Lvar (Pvar.mk name proc_name)) pfs
-
-  (* Update the set of written formals when it finds a sequence
-     n$0=*&i;
-     ....
-    *n$0=..;
-*)
-  let update_state_formal node pdesc formal_set =
-    let ptr_formals = ptr_formals pdesc in
-    let ids_assigned_to_formals, dereferenced_ids =
-      List.fold
-        ~f:(fun (acc1, acc2) (i, _) ->
-          match i with
-          | Sil.Load (lhs_id, rhs_exp, _, _) when List.mem ptr_formals rhs_exp ~equal:Exp.equal
-           -> ((lhs_id, rhs_exp) :: acc1, acc2)
-          | Sil.Store (Exp.Var lhs_id, _, _, _)
-           -> (acc1, lhs_id :: acc2)
-          | _
-           -> (acc1, acc2))
-        (CFG.instr_ids node) ~init:([], [])
-    in
-    List.fold
-      ~f:(fun acc_set (id, formal_param) ->
-        if List.mem dereferenced_ids id ~equal:Ident.equal then exp_add_set formal_param acc_set
-        else acc_set)
-      ids_assigned_to_formals ~init:formal_set
-
-  let exec_instr
-      ( {Domain.uninit_vars= uninit; Domain.aliased_vars= _; Domain.prepost= pre, wformals} as
-      astate ) {ProcData.pdesc} node = function
-    | Sil.Load (_, rhs_exp, _, _)
-     -> let post = update_state_formal node pdesc wformals in
-        let set_ptr_formals = ptr_formals pdesc in
-        let pre' =
-          if List.mem set_ptr_formals ~equal:Exp.equal rhs_exp && not (exp_in_set rhs_exp post)
-          then exp_add_set rhs_exp pre
-          else pre
-        in
-        {astate with prepost= (pre', post)}
-    | Sil.Store (lhs_exp, _, rhs_exp, _)
-     -> if exp_in_set rhs_exp uninit then astate
-        else {astate with Domain.uninit_vars= exp_remove_set lhs_exp uninit}
-    | Sil.Call (ret_id, Exp.Const Const.Cfun callee_pname, actual_params, _, _)
-      when not intraprocedural_only
-     -> (
-        let astate' =
-          Option.value_map
-            ~f:(fun (ret_id, _) ->
-              {astate with Domain.uninit_vars= exp_remove_set (Exp.Var ret_id) uninit})
-            ~default:astate ret_id
-        in
-        match
-          ( zip_actual_formal_params callee_pname actual_params
-          , Summary.read_summary pdesc callee_pname )
-        with
-        | (Some assoc_actual_formal, actual), Some {pre= _; post= wformals_callee}
-         -> let initialized_actual_params =
-              List.filter
-                ~f:(fun a ->
-                  match List.Assoc.find assoc_actual_formal ~equal:Exp.equal a with
-                  | Some fp
-                   -> D.mem (Var.of_pvar (Pvar.mk fp callee_pname)) wformals_callee
-                  | None
-                   -> false)
-                actual
-            in
-            let uninit' = set_difference uninit initialized_actual_params in
-            {astate with Domain.uninit_vars= uninit'; Domain.prepost= astate'.prepost}
-        | _, _
-         -> L.(debug Linters Medium)
-              "Warning: unable to deal with callee '%s' summary@\n"
-              (Typ.Procname.to_string callee_pname) ;
-            astate' )
-    | Sil.Call (_, _, actual_params, _, _)
-     -> (* in case of intraprocedural only analysis we assume that parameters
-           passed by reference to a function will be initialized inside that function *)
-        let actual_passed_by_ref =
-          List.fold
-            ~f:(fun acc (e, t) -> match t.Typ.desc with Typ.Tptr _ -> e :: acc | _ -> acc)
-            ~init:[] actual_params
-        in
-        let uninit' = set_difference uninit actual_passed_by_ref in
-        {astate with Domain.uninit_vars= uninit'}
-    | Sil.Declare_locals (pvar_list, _)
-     -> List.fold
-          ~f:(fun astate_acc (pvar, t) ->
-            if is_basic_typ t then
-              { astate_acc with
-                Domain.uninit_vars= D.add (Var.of_pvar pvar) astate_acc.Domain.uninit_vars }
-            else astate_acc)
-          ~init:astate pvar_list
-    | Sil.Remove_temps _ | Sil.Abstract _ | Sil.Nullify _ | Sil.Prune _
-     -> astate
-end
-
-module CFG = ProcCfg.OneInstrPerNode (ProcCfg.Normal)
-module Analyzer = AbstractInterpreter.Make (CFG) (TransferFunctions)
-
-let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
-  let cfg = CFG.from_pdesc proc_desc in
-  (* start with empty set of uninit local vars and  empty set of init formal params *)
-  let init =
-    { RecordDomain.uninit_vars= UninitVars.empty
-    ; RecordDomain.aliased_vars= AliasedVars.empty
-    ; RecordDomain.prepost= (D.empty, D.empty) }
-  in
-  let invariant_map =
-    Analyzer.exec_cfg cfg (ProcData.make_default proc_desc tenv) ~initial:init ~debug:true
   in
   let report_uninit_value uninit_vars instr =
     let report message loc =
@@ -240,9 +161,10 @@ let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
         | Some node_id -> (
           match Analyzer.extract_pre node_id invariant_map with
           | Some
-              { RecordDomain.uninit_vars= uninitialized_vars
+              ( { RecordDomain.uninit_vars= uninitialized_vars
                 ; RecordDomain.aliased_vars= _
                 ; RecordDomain.prepost= _ }
+              , _ )
            -> report_uninit_value uninitialized_vars instr
           | None
            -> () )
@@ -252,7 +174,8 @@ let checker {Callbacks.tenv; summary; proc_desc} : Specs.summary =
   List.iter (CFG.nodes cfg) ~f:report_on_node ;
   match Analyzer.extract_post (CFG.id (CFG.exit_node cfg)) invariant_map with
   | Some
-      {RecordDomain.uninit_vars= _; RecordDomain.aliased_vars= _; RecordDomain.prepost= pre, post}
+      ( {RecordDomain.uninit_vars= _; RecordDomain.aliased_vars= _; RecordDomain.prepost= pre, post}
+      , _ )
    -> Summary.update_summary {pre; post} summary
   | None
    -> if Procdesc.Node.get_succs (Procdesc.get_start_node proc_desc) <> [] then (