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[uninit] Use type information from locals if argument has type void* in function signature

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Summary: In an intra-procedural analysis we assume that parameters passed by reference to a function will be initialized inside that function. We use the type information of an actual parameter to initialize the fields of the struct. This does not work if a function has a parameter of type void* as the actual parameters also has type void*. To solve this issue, we use type information from local variables.

Reviewed By: jvillard

Differential Revision: D20670253

fbshipit-source-id: dc9f051ef
master
Daiva Naudziuniene 5 years ago committed by Facebook GitHub Bot
parent f343be40f4
commit 526af36061
4 changed files with 66 additions and 53 deletions
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70
infer/src/checkers/uninit.ml
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@ -40,6 +40,37 @@ let should_report_on_type t =
type extras = {formals: FormalMap.t; summary: Summary.t}
module Initial = struct
let get_locals tenv pdesc =
List.fold (Procdesc.get_locals pdesc) ~init:[]
~f:(fun acc (var_data : ProcAttributes.var_data) ->
let pvar = Pvar.mk var_data.name (Procdesc.get_proc_name pdesc) in
let base_access_expr = HilExp.AccessExpression.base (Var.of_pvar pvar, var_data.typ) in
match var_data.typ.Typ.desc with
| Typ.Tstruct qual_name
(* T30105165 remove filtering after we improve union translation *)
when not (Typ.Name.is_union qual_name) -> (
match Tenv.lookup tenv qual_name with
| Some {fields} ->
let flist =
List.fold
~f:(fun acc' (fn, _, _) ->
HilExp.AccessExpression.field_offset base_access_expr fn :: acc' )
~init:acc fields
in
base_access_expr :: flist
(* for struct we take the struct address, and the access_path
to the fields one level down *)
| _ ->
acc )
| Typ.Tarray {elt} ->
HilExp.AccessExpression.array_offset base_access_expr elt None :: acc
| Typ.Tptr _ ->
base_access_expr :: HilExp.AccessExpression.dereference base_access_expr :: acc
| _ ->
base_access_expr :: acc )
end
module TransferFunctions (CFG : ProcCfg.S) = struct
module CFG = CFG
module Domain = RecordDomain
@ -240,8 +271,6 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
{astate with maybe_uninit_vars}
else astate
| Call (_, call, actuals, _, loc) ->
(* in case of intraprocedural only analysis we assume that parameters passed by reference
to a function will be initialized inside that function *)
let pname_opt = match call with Direct pname -> Some pname | Indirect _ -> None in
let callee_formals_opt = Option.bind pname_opt ~f:get_formals in
let is_initializing_all_args =
@ -274,11 +303,15 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
MaybeUninitVars.remove_all_fields tenv base
(MaybeUninitVars.remove access_expr_to_remove acc)
| _, {Typ.desc= Tptr _} -> (
(* in case of intraprocedural only analysis we assume that parameters passed by reference
to a function will be initialized inside that function *)
match pname_opt with
| Some pname when Config.uninit_interproc ->
remove_initialized_params summary pname acc idx access_expr_to_remove true
| _ ->
MaybeUninitVars.remove_everything_under tenv access_expr_to_remove acc )
let locals = MaybeUninitVars.of_list (Initial.get_locals tenv pdesc) in
MaybeUninitVars.remove_everything_under tenv locals access_expr_to_remove
acc )
| _ ->
acc )
| HilExp.Closure (_, apl) ->
@ -306,37 +339,6 @@ end
module CFG = ProcCfg.Normal
module Analyzer = LowerHil.MakeAbstractInterpreter (TransferFunctions (CFG))
module Initial = struct
let get_locals tenv pdesc =
List.fold (Procdesc.get_locals pdesc) ~init:[]
~f:(fun acc (var_data : ProcAttributes.var_data) ->
let pvar = Pvar.mk var_data.name (Procdesc.get_proc_name pdesc) in
let base_access_expr = HilExp.AccessExpression.base (Var.of_pvar pvar, var_data.typ) in
match var_data.typ.Typ.desc with
| Typ.Tstruct qual_name
(* T30105165 remove filtering after we improve union translation *)
when not (Typ.Name.is_union qual_name) -> (
match Tenv.lookup tenv qual_name with
| Some {fields} ->
let flist =
List.fold
~f:(fun acc' (fn, _, _) ->
HilExp.AccessExpression.field_offset base_access_expr fn :: acc' )
~init:acc fields
in
base_access_expr :: flist
(* for struct we take the struct address, and the access_path
to the fields one level down *)
| _ ->
acc )
| Typ.Tarray {elt} ->
HilExp.AccessExpression.array_offset base_access_expr elt None :: acc
| Typ.Tptr _ ->
base_access_expr :: HilExp.AccessExpression.dereference base_access_expr :: acc
| _ ->
base_access_expr :: acc )
end
let checker {Callbacks.exe_env; summary} : Summary.t =
let proc_desc = Summary.get_proc_desc summary in
let proc_name = Summary.get_proc_name summary in

24
infer/src/checkers/uninitDomain.ml
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@ -43,10 +43,14 @@ module MaybeUninitVars = struct
maybe_uninit_vars
let remove_all_fields tenv base maybe_uninit_vars =
match base with
| _, {Typ.desc= Tptr ({Typ.desc= Tstruct name_struct}, _)} | _, {Typ.desc= Tstruct name_struct}
-> (
let find_access_expr_typ tenv access_expr vars =
try HilExp.AccessExpression.get_typ (find access_expr vars) tenv with Caml.Not_found -> None
let remove_all_fields tenv ?(locals = empty) base maybe_uninit_vars =
let remove_all_fields_inner base_type =
match base_type.Typ.desc with
| Typ.Tptr ({Typ.desc= Tstruct name_struct}, _) | Typ.Tstruct name_struct -> (
match Tenv.lookup tenv name_struct with
| Some {fields} ->
List.fold fields ~init:maybe_uninit_vars ~f:(fun acc (fn, _, _) ->
@ -57,6 +61,13 @@ module MaybeUninitVars = struct
maybe_uninit_vars )
| _ ->
maybe_uninit_vars
in
match base with
| _, {Typ.desc= Tptr ({Typ.desc= Tvoid}, _)} ->
Option.value_map ~default:maybe_uninit_vars ~f:remove_all_fields_inner
(find_access_expr_typ tenv (HilExp.AccessExpression.base base) locals)
| _, typ ->
remove_all_fields_inner typ
let remove_dereference_access base maybe_uninit_vars =
@ -79,9 +90,10 @@ module MaybeUninitVars = struct
maybe_uninit_vars
let remove_everything_under tenv access_expr maybe_uninit_vars =
let remove_everything_under tenv locals access_expr maybe_uninit_vars =
let base = HilExp.AccessExpression.get_base access_expr in
maybe_uninit_vars |> remove access_expr |> remove_all_fields tenv base
maybe_uninit_vars |> remove access_expr
|> remove_all_fields tenv ~locals base
|> remove_all_array_elements base |> remove_dereference_access base
end

1
infer/tests/codetoanalyze/cpp/uninit/issues.exp
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@ -10,7 +10,6 @@ codetoanalyze/cpp/uninit/members.cpp, access_pointer_members_bad, 5, UNINITIALIZ
codetoanalyze/cpp/uninit/struct.cpp, pass_basic_type_field_bad, 3, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/struct.cpp, struct_partial_init_bad, 6, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/struct.cpp, struct_uninit_bad, 3, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/uninit.cpp, FP_pointer_param_void_star_ok, 4, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/uninit.cpp, bad1, 2, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/uninit.cpp, bad2, 2, UNINITIALIZED_VALUE, no_bucket, ERROR, []
codetoanalyze/cpp/uninit/uninit.cpp, branch1_FP, 11, UNINITIALIZED_VALUE, no_bucket, ERROR, []

6
infer/tests/codetoanalyze/cpp/uninit/uninit.cpp
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@ -269,11 +269,11 @@ int no_warning_noreturn_callee_ok(bool t) {
void some_f(void* p);
int* FP_pointer_param_void_star_ok() {
int* pointer_param_void_star_ok() {
A a;
int* res;
some_f(&a); // the type of a here is void*, hence no fields are found
return a.ptr; // false positive
some_f(&a);
return a.ptr;
}
short union_ok() {

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