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(*
* Copyright (c) 2017-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*)
open! IStd
open AbsLoc
open! AbstractDomain.Types
module L = Logging
module Dom = BufferOverrunDomain
module Relation = BufferOverrunDomainRelation
module PO = BufferOverrunProofObligations
module Sem = BufferOverrunSemantics
module Trace = BufferOverrunTrace
module TraceSet = Trace.Set
module Exec = struct
let get_alist_size alist mem =
let size_powloc = Dom.Val.get_pow_loc alist in
Dom.Mem.find_set size_powloc mem
let load_val id val_ mem =
let locs = val_ |> Dom.Val.get_all_locs in
let v = Dom.Mem.find_set locs mem in
let mem = Dom.Mem.add_stack (Loc.of_id id) v mem in
if PowLoc.is_singleton locs && not v.represents_multiple_values then
Dom.Mem.load_simple_alias id (PowLoc.min_elt locs) mem
else mem
type decl_local =
Typ.Procname.t
-> node_hash:int
-> Location.t
-> Loc.t
-> Typ.t
-> inst_num:int
-> represents_multiple_values:bool
-> dimension:int
-> Dom.Mem.astate
-> Dom.Mem.astate * int
let decl_local_array :
decl_local:decl_local
-> Typ.Procname.t
-> node_hash:int
-> Location.t
-> Loc.t
-> Typ.t
-> length:IntLit.t option
-> ?stride:int
-> inst_num:int
-> represents_multiple_values:bool
-> dimension:int
-> Dom.Mem.astate
-> Dom.Mem.astate * int =
fun ~decl_local pname ~node_hash location loc typ ~length ?stride ~inst_num
~represents_multiple_values ~dimension mem ->
let offset = Itv.zero in
let size = Option.value_map ~default:Itv.top ~f:Itv.of_int_lit length in
let path = Loc.get_path loc in
let allocsite = Allocsite.make pname ~node_hash ~inst_num ~dimension ~path in
let mem =
let arr =
Dom.Val.of_array_alloc allocsite ~stride ~offset ~size
|> Dom.Val.add_trace_elem (Trace.ArrDecl location)
|> Dom.Val.sets_represents_multiple_values ~represents_multiple_values
in
if Int.equal dimension 1 then Dom.Mem.add_stack loc arr mem else Dom.Mem.add_heap loc arr mem
in
let mem = Dom.Mem.init_array_relation allocsite ~offset ~size ~size_exp_opt:None mem in
let loc = Loc.of_allocsite allocsite in
let mem, _ =
decl_local pname ~node_hash location loc typ ~inst_num ~represents_multiple_values:true
~dimension:(dimension + 1) mem
in
(mem, inst_num + 1)
let decl_local_collection :
Typ.Procname.t
-> node_hash:int
-> Location.t
-> Loc.t
-> inst_num:int
-> represents_multiple_values:bool
-> dimension:int
-> Dom.Mem.astate
-> Dom.Mem.astate * int =
fun pname ~node_hash location loc ~inst_num ~represents_multiple_values ~dimension mem ->
let path = Loc.get_path loc in
let allocsite = Allocsite.make pname ~node_hash ~inst_num ~dimension ~path in
let alloc_loc = Loc.of_allocsite allocsite in
let mem =
let alist =
Dom.Val.of_pow_loc (PowLoc.singleton alloc_loc)
|> Dom.Val.add_trace_elem (Trace.ArrDecl location)
|> Dom.Val.sets_represents_multiple_values ~represents_multiple_values
in
if Int.equal dimension 1 then Dom.Mem.add_stack loc alist mem
else
let size = Dom.Val.Itv.zero in
Dom.Mem.add_heap loc alist mem |> Dom.Mem.add_heap alloc_loc size
in
(mem, inst_num + 1)
type c_sym_array_kind = CSymArray_Array | CSymArray_Pointer
type decl_sym_val =
Typ.Procname.t
-> Itv.SymbolPath.partial
-> Tenv.t
-> node_hash:int
-> Location.t
-> represents_multiple_values:bool
-> depth:int
-> Loc.t
-> Typ.t
-> Dom.Mem.astate
-> Dom.Mem.astate
let decl_sym_arr :
decl_sym_val:decl_sym_val
-> c_sym_array_kind
-> Typ.Procname.t
-> Itv.SymbolTable.t
-> Itv.SymbolPath.partial
-> Tenv.t
-> node_hash:int
-> Location.t
-> represents_multiple_values:bool
-> depth:int
-> Loc.t
-> Typ.t
-> ?offset:Itv.t
-> ?size:Itv.t
-> ?stride:int
-> inst_num:int
-> new_sym_num:Itv.Counter.t
-> new_alloc_num:Itv.Counter.t
-> Dom.Mem.astate
-> Dom.Mem.astate =
fun ~decl_sym_val array_kind pname symbol_table path tenv ~node_hash location
~represents_multiple_values ~depth loc typ ?offset ?size ?stride ~inst_num ~new_sym_num
~new_alloc_num mem ->
let option_value opt_x default_f = match opt_x with Some x -> x | None -> default_f () in
let offset =
option_value offset (fun () ->
Itv.make_sym pname symbol_table (Itv.SymbolPath.offset path) new_sym_num )
in
let size =
option_value size (fun () ->
Itv.make_sym ~unsigned:true pname symbol_table (Itv.SymbolPath.length path) new_sym_num
)
in
let allocsite =
let alloc_num = Itv.Counter.next new_alloc_num in
Allocsite.make pname ~node_hash ~inst_num ~dimension:alloc_num ~path:(Some path)
in
let mem =
let arr =
let elem = Trace.SymAssign (loc, location) in
Dom.Val.of_array_alloc allocsite ~stride ~offset ~size
|> Dom.Val.add_trace_elem elem
|> Dom.Val.sets_represents_multiple_values ~represents_multiple_values
in
mem |> Dom.Mem.add_heap loc arr |> Dom.Mem.init_param_relation loc
|> Dom.Mem.init_array_relation allocsite ~offset ~size ~size_exp_opt:None
in
let deref_loc = Loc.of_allocsite allocsite in
let path = Itv.SymbolPath.index path in
let represents_multiple_values =
match array_kind with CSymArray_Array -> true | CSymArray_Pointer -> false
(* unsound but avoids many FPs for non-array pointers *)
in
decl_sym_val pname path tenv ~node_hash location ~represents_multiple_values ~depth deref_loc
typ mem
let decl_sym_java_ptr :
decl_sym_val:decl_sym_val
-> Typ.Procname.t
-> Itv.SymbolPath.partial
-> Tenv.t
-> node_hash:int
-> Location.t
-> represents_multiple_values:bool
-> depth:int
-> Loc.t
-> Typ.t
-> inst_num:int
-> new_alloc_num:Itv.Counter.t
-> Dom.Mem.astate
-> Dom.Mem.astate =
fun ~decl_sym_val pname path tenv ~node_hash location ~represents_multiple_values ~depth loc typ
~inst_num ~new_alloc_num mem ->
let alloc_num = Itv.Counter.next new_alloc_num in
let elem = Trace.SymAssign (loc, location) in
let allocsite =
Allocsite.make pname ~node_hash ~inst_num ~dimension:alloc_num ~path:(Some path)
in
let alloc_loc = Loc.of_allocsite allocsite in
let v =
Dom.Val.of_pow_loc (PowLoc.singleton alloc_loc)
|> Dom.Val.add_trace_elem elem
|> Dom.Val.sets_represents_multiple_values ~represents_multiple_values
in
let mem = Dom.Mem.add_heap loc v mem in
decl_sym_val pname path tenv ~node_hash location ~represents_multiple_values ~depth alloc_loc
typ mem
let decl_sym_collection :
Typ.Procname.t
-> Itv.SymbolTable.t
-> Itv.SymbolPath.partial
-> Location.t
-> represents_multiple_values:bool
-> Loc.t
-> new_sym_num:Itv.Counter.t
-> Dom.Mem.astate
-> Dom.Mem.astate =
fun pname symbol_table path location ~represents_multiple_values loc ~new_sym_num mem ->
let size =
Itv.make_sym ~unsigned:true pname symbol_table (Itv.SymbolPath.length path) new_sym_num
|> Dom.Val.of_itv
|> Dom.Val.add_trace_elem (Trace.SymAssign (loc, location))
|> Dom.Val.sets_represents_multiple_values ~represents_multiple_values
in
Dom.Mem.add_heap loc size mem
let init_array_fields tenv pname path ~node_hash typ locs ?dyn_length mem =
let rec init_field path locs dimension ?dyn_length (mem, inst_num) (field_name, field_typ, _) =
let field_path = Option.map path ~f:(fun path -> Symb.SymbolPath.field path field_name) in
let field_loc = PowLoc.append_field locs ~fn:field_name in
let mem =
match field_typ.Typ.desc with
| Tarray {length= Some length; stride} ->
let length = Itv.of_int_lit length in
let length =
Option.value_map dyn_length ~default:length ~f:(fun dyn_length ->
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_exn in
let allocsite =
Allocsite.make pname ~node_hash ~inst_num ~dimension ~path:field_path
in
let offset, size = (Itv.zero, length) in
let v = Dom.Val.of_array_alloc allocsite ~stride ~offset ~size in
mem |> Dom.Mem.strong_update field_loc v
|> Dom.Mem.init_array_relation allocsite ~offset ~size ~size_exp_opt:None
| _ ->
init_fields field_path field_typ field_loc dimension ?dyn_length mem
in
(mem, inst_num + 1)
and init_fields path typ locs dimension ?dyn_length mem =
match typ.Typ.desc with
| Tstruct typename -> (
match Tenv.lookup tenv typename with
| Some str ->
let f = init_field path locs (dimension + 1) in
IList.fold_last ~f ~f_last:(f ?dyn_length) ~init:(mem, 1) str.Typ.Struct.fields |> fst
| None ->
mem )
| _ ->
mem
in
init_fields path typ locs 1 ?dyn_length mem
let rec set_dyn_length tenv typ locs dyn_length mem =
match typ.Typ.desc with
| Tstruct typename -> (
match Tenv.lookup tenv typename with
| Some {fields} when not (List.is_empty fields) -> (
let field_name, field_typ, _ = List.last_exn fields in
let field_loc = PowLoc.append_field locs ~fn:field_name in
match field_typ.Typ.desc with
| Tarray {length= Some length} ->
let length = Itv.plus (Itv.of_int_lit length) dyn_length in
let v = Dom.Mem.find_set field_loc mem |> Dom.Val.set_array_size length in
Dom.Mem.strong_update field_loc v mem
| _ ->
set_dyn_length tenv field_typ field_loc dyn_length mem )
| _ ->
mem )
| _ ->
mem
end
module Check = struct
let check_access ~size ~idx ~size_sym_exp ~idx_sym_exp ~relation ~arr ~idx_traces
?(is_collection_add = false) location cond_set =
let arr_traces = Dom.Val.get_traces arr in
match (size, idx) with
| NonBottom length, NonBottom idx ->
let traces = TraceSet.merge ~arr_traces ~idx_traces location in
PO.ConditionSet.add_array_access location ~size:length ~idx ~size_sym_exp ~idx_sym_exp
~relation ~is_collection_add traces cond_set
| _ ->
cond_set
let array_access ~arr ~idx ~idx_sym_exp ~relation ~is_plus location cond_set =
let arr_blk = Dom.Val.get_array_blk arr in
let size = ArrayBlk.sizeof arr_blk in
let size_sym_exp = Relation.SymExp.of_sym (Dom.Val.get_size_sym arr) in
let offset = ArrayBlk.offsetof arr_blk in
let offset_sym_exp = Relation.SymExp.of_sym (Dom.Val.get_offset_sym arr) in
let idx_itv = Dom.Val.get_itv idx in
let idx_traces = Dom.Val.get_traces idx in
let idx_in_blk = (if is_plus then Itv.plus else Itv.minus) offset idx_itv in
let idx_sym_exp =
Option.map2 offset_sym_exp idx_sym_exp ~f:(fun offset_sym_exp idx_sym_exp ->
let op = if is_plus then Relation.SymExp.plus else Relation.SymExp.minus in
op idx_sym_exp offset_sym_exp )
in
L.(debug BufferOverrun Verbose)
"@[<v 2>Add condition :@,array: %a@, idx: %a@,@]@." ArrayBlk.pp arr_blk Itv.pp idx_in_blk ;
check_access ~size ~idx:idx_in_blk ~size_sym_exp ~idx_sym_exp ~relation ~arr ~idx_traces
location cond_set
let collection_access ~array_exp ~index_exp ?(is_collection_add = false) mem location cond_set =
let idx = Sem.eval index_exp mem in
let arr = Sem.eval array_exp mem in
let idx_traces = Dom.Val.get_traces idx in
let size = Exec.get_alist_size arr mem |> Dom.Val.get_itv in
let idx = Dom.Val.get_itv idx in
let relation = Dom.Mem.get_relation mem in
check_access ~size ~idx ~size_sym_exp:None ~idx_sym_exp:None ~relation ~arr ~idx_traces
~is_collection_add location cond_set
let lindex ~array_exp ~index_exp mem location cond_set =
let idx = Sem.eval index_exp mem in
let arr = Sem.eval_arr array_exp mem in
let idx_sym_exp = Relation.SymExp.of_exp ~get_sym_f:(Sem.get_sym_f mem) index_exp in
let relation = Dom.Mem.get_relation mem in
array_access ~arr ~idx ~idx_sym_exp ~relation ~is_plus:true location cond_set
let array_access_byte ~arr ~idx ~relation ~is_plus location cond_set =
let arr_blk = Dom.Val.get_array_blk arr in
let size = ArrayBlk.sizeof_byte arr_blk in
let offset = ArrayBlk.offsetof arr_blk in
let idx_itv = Dom.Val.get_itv idx in
let idx_traces = Dom.Val.get_traces idx in
let idx_in_blk = (if is_plus then Itv.plus else Itv.minus) offset idx_itv in
L.(debug BufferOverrun Verbose)
"@[<v 2>Add condition :@,array: %a@, idx: %a@,@]@." ArrayBlk.pp arr_blk Itv.pp idx_in_blk ;
check_access ~size ~idx:idx_in_blk ~size_sym_exp:None ~idx_sym_exp:None ~relation ~arr
~idx_traces location cond_set ~is_collection_add:true
let lindex_byte ~array_exp ~byte_index_exp mem location cond_set =
let idx = Sem.eval byte_index_exp mem in
let arr = Sem.eval_arr array_exp mem in
let relation = Dom.Mem.get_relation mem in
array_access_byte ~arr ~idx ~relation ~is_plus:true location cond_set
let binary_operation integer_type_widths bop ~lhs ~rhs location cond_set =
let lhs_itv = Dom.Val.get_itv lhs in
let rhs_itv = Dom.Val.get_itv rhs in
match (lhs_itv, rhs_itv) with
| NonBottom lhs_itv, NonBottom rhs_itv ->
let traces =
TraceSet.join (Dom.Val.get_traces lhs) (Dom.Val.get_traces rhs)
|> TraceSet.add_elem (Trace.Binop location)
in
L.(debug BufferOverrun Verbose)
"@[<v 2>Add condition :@,bop:%s@, lhs: %a@, rhs: %a@,@]@." (Binop.str Pp.text bop)
Itv.ItvPure.pp lhs_itv Itv.ItvPure.pp rhs_itv ;
PO.ConditionSet.add_binary_operation integer_type_widths location bop ~lhs:lhs_itv
~rhs:rhs_itv traces cond_set
| _, _ ->
cond_set
end