Fix IntLit.to_int interface and uses.

Summary: `IntLit.to_int` could raise, was not documented until recently and was not named `_exn`.  Switch to option type and fix uses.

Reviewed By: jeremydubreil

Differential Revision: D8865525

fbshipit-source-id: f5ec2f221

infer/src/IR/IntLit.ml

@@ -59,7 +59,9 @@ let of_int32 i = of_int64 (Int64.of_int32 i)
 
 let of_int i = of_int64 (Int64.of_int i)
 
-let to_int (_, i, _) = Int64.to_int_exn i
+let to_int (_, i, _) = Int64.to_int i
+
+let to_int_exn (_, i, _) = Int64.to_int_exn i
 
 let to_float (_, i, _) = Int64.to_float i
 

infer/src/IR/IntLit.mli

@@ -87,8 +87,9 @@ val shift_right : t -> t -> t
 
 val sub : t -> t -> t
 
-val to_int : t -> int
-(** throws exception if literal is not representable as an OCaml int *)
+val to_int : t -> int option
+
+val to_int_exn : t -> int
 
 val to_float : t -> float
 

infer/src/biabduction/BuiltinDefn.ml

@@ -717,7 +717,7 @@ let execute___split_get_nth {Builtin.tenv; pdesc; prop_; path; ret_id_typ; args}
       match (n_lexp1, n_lexp2, n_lexp3) with
       | Exp.Const (Const.Cstr str1), Exp.Const (Const.Cstr str2), Exp.Const (Const.Cint n_sil)
         -> (
-          let n = IntLit.to_int n_sil in
+          let n = IntLit.to_int_exn n_sil in
           try
             let parts = Str.split (Str.regexp_string str2) str1 in
             let n_part = List.nth_exn parts n in

infer/src/biabduction/SymExec.ml

@@ -388,7 +388,7 @@ let reason_to_skip ~callee_desc : string option =
 (** In case of constant string dereference, return the result immediately *)
 let check_constant_string_dereference lexp =
   let string_lookup s n =
-    let c = try Char.to_int s.[IntLit.to_int n] with Invalid_argument _ -> 0 in
+    let c = try Char.to_int s.[IntLit.to_int_exn n] with Invalid_argument _ -> 0 in
     Exp.int (IntLit.of_int c)
   in
   match lexp with

infer/src/bufferoverrun/bufferOverrunChecker.ml

@@ -269,7 +269,7 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
           let rec decl_local pname ~node_hash location loc typ ~inst_num ~dimension mem =
             match typ.Typ.desc with
             | Typ.Tarray {elt= typ; length; stride} ->
-                let stride = Option.map ~f:IntLit.to_int stride in
+                let stride = Option.map ~f:IntLit.to_int_exn stride in
                 BoUtils.Exec.decl_local_array ~decl_local pname ~node_hash location loc typ ~length
                   ?stride ~inst_num ~dimension mem
             | Typ.Tstruct typname -> (

infer/src/bufferoverrun/bufferOverrunModels.ml

@@ -177,7 +177,7 @@ let set_array_length array length_exp =
     match array with
     | Exp.Lvar array_pvar, {Typ.desc= Typ.Tarray {elt; stride}} ->
         let length = Sem.eval length_exp mem |> Dom.Val.get_itv in
-        let stride = Option.map ~f:IntLit.to_int stride in
+        let stride = Option.map ~f:IntLit.to_int_exn stride in
         let v =
           Sem.eval_array_alloc pname ~node_hash elt ~stride ~offset:Itv.zero ~size:length
             ~inst_num:0 ~dimension:1

infer/src/bufferoverrun/bufferOverrunSemantics.ml

@@ -14,8 +14,8 @@ open! AbstractDomain.Types
 open BufferOverrunDomain
 
 let eval_const : Const.t -> Val.t = function
-  | Const.Cint intlit -> (
-    try Val.of_int (IntLit.to_int intlit) with _ -> Val.Itv.top )
+  | Const.Cint intlit ->
+      Option.value_map ~default:Val.Itv.top ~f:Val.of_int (IntLit.to_int intlit)
   | Const.Cfloat f ->
       f |> int_of_float |> Val.of_int
   | _ ->
@@ -60,9 +60,9 @@ let rec sizeof (typ: Typ.t) : int =
   | Typ.Tstruct _ | Typ.TVar _ ->
       4 (* TODO *)
   | Typ.Tarray {length= Some length; stride= Some stride} ->
-      IntLit.to_int stride * IntLit.to_int length
+      IntLit.to_int_exn stride * IntLit.to_int_exn length
   | Typ.Tarray {elt; length= Some length; stride= None} ->
-      sizeof elt * IntLit.to_int length
+      sizeof elt * IntLit.to_int_exn length
   | _ ->
       4
 

infer/src/bufferoverrun/bufferOverrunUtils.ml

@@ -94,7 +94,7 @@ module Exec = struct
                   let i = Dom.Val.get_itv (Sem.eval dyn_length mem) in
                   Itv.plus i length )
             in
-            let stride = Option.map stride ~f:IntLit.to_int in
+            let stride = Option.map stride ~f:IntLit.to_int_exn in
             let v =
               Sem.eval_array_alloc pname ~node_hash typ ~stride ~offset:Itv.zero ~size:length
                 ~inst_num ~dimension

infer/src/bufferoverrun/itv.ml

@@ -1912,7 +1912,7 @@ let of_bool = function
 
 let of_int : int -> astate = fun n -> NonBottom (ItvPure.of_int n)
 
-let of_int_lit n = try of_int (IntLit.to_int n) with _ -> top
+let of_int_lit n = Option.value_map ~default:top ~f:of_int (IntLit.to_int n)
 
 let of_int64 : Int64.t -> astate =
  fun n -> Int64.to_int n |> Option.value_map ~f:of_int ~default:top

infer/src/clang/cTrans.ml

@@ -411,7 +411,7 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
               List.map field_exp_typs ~f:(fun exp_typ -> (fill_typ_with_zero exp_typ).control)
               |> collect_controls trans_state.context.procdesc |> mk_trans_result exp_typ
           | Tarray {elt= field_typ; length= Some n} ->
-              let size = IntLit.to_int n in
+              let size = IntLit.to_int_exn n in
               let indices = CGeneral_utils.list_range 0 (size - 1) in
               List.map indices ~f:(fun i ->
                   let idx_exp = Exp.Const (Const.Cint (IntLit.of_int i)) in

infer/src/quandary/ClangTrace.ml

@@ -330,7 +330,9 @@ module SinkKind = struct
             match HilExp.eval exp with
             | Some (Const.Cint i) ->
                 (* check if the data kind might be CURLOPT_URL *)
-                if controls_request (IntLit.to_int i) then taint_after_nth 1 URL actuals else None
+                IntLit.to_int i
+                |> Option.bind ~f:(fun n ->
+                       if controls_request n then taint_after_nth 1 URL actuals else None )
             | _ ->
                 (* can't statically resolve data kind; taint it just in case *)
                 taint_after_nth 1 URL actuals )