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(*
* Copyright (c) 2013-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
let is_modelled_static_function name =
[objc] Refactor modeling of CoreFoundation and CoreGraphics libraries Summary: The diff is very big but it's mostly removing code. It was inspired by the fact that we were getting Dead Store FPs because we were modeling some functions from CoreFoundation and CoreGraphics directly as alloc in the frontend, which caused the parameters of the function to be seen as dead. See the new test. To deal with this, if we are going to skip the function, we model it as malloc instead. Given how many models we had for those "model as malloc" functions, I removed them to rely solely on the new mechanism. The modeling of malloc and release was still based on the old retain count implementation, even though all we do here is a malloc/free kind of analysis. I also changed that to be actually malloc/free which removed many Assert false in the tests. CFRelease is not exactly free though, and it's possible to use the variable afterwards. So used a custom free builtin that only cares about removing the Memory attribute and focuses on minimizing Memory Leaks FPs. Otherwise we were translating CFBridgingRelease as a special cast, and this wasn't working. To simplify this as well, I removed all the code for the special cast, and just modeled CFBridgingRelease and CFAutorelease also as free_cf, to avoid Memory Leak false positives. I also treated the cast __bridge_transfer as a free_cf model. This means we stopped trying to report Memory Leaks on those objects. The modeling of CoreGraph release functions was done in the frontend, but seemed simpler to also simplify that code and model all the relevant functions. Reviewed By: sblackshear Differential Revision: D6397150 fbshipit-source-id: b1dc636
7 years ago
let modelled_functions = ["_dispatch_once"; "CFAutorelease"; "CFBridgingRelease"] in
List.mem ~equal:String.equal modelled_functions name
[objc] Refactor modeling of CoreFoundation and CoreGraphics libraries Summary: The diff is very big but it's mostly removing code. It was inspired by the fact that we were getting Dead Store FPs because we were modeling some functions from CoreFoundation and CoreGraphics directly as alloc in the frontend, which caused the parameters of the function to be seen as dead. See the new test. To deal with this, if we are going to skip the function, we model it as malloc instead. Given how many models we had for those "model as malloc" functions, I removed them to rely solely on the new mechanism. The modeling of malloc and release was still based on the old retain count implementation, even though all we do here is a malloc/free kind of analysis. I also changed that to be actually malloc/free which removed many Assert false in the tests. CFRelease is not exactly free though, and it's possible to use the variable afterwards. So used a custom free builtin that only cares about removing the Memory attribute and focuses on minimizing Memory Leaks FPs. Otherwise we were translating CFBridgingRelease as a special cast, and this wasn't working. To simplify this as well, I removed all the code for the special cast, and just modeled CFBridgingRelease and CFAutorelease also as free_cf, to avoid Memory Leak false positives. I also treated the cast __bridge_transfer as a free_cf model. This means we stopped trying to report Memory Leaks on those objects. The modeling of CoreGraph release functions was done in the frontend, but seemed simpler to also simplify that code and model all the relevant functions. Reviewed By: sblackshear Differential Revision: D6397150 fbshipit-source-id: b1dc636
7 years ago
let class_equal class_typename class_name = String.equal (Typ.Name.name class_typename) class_name
let is_builtin_expect pname =
String.equal (Typ.Procname.to_string pname) CFrontend_config.builtin_expect
let is_builtin_object_size pname =
String.equal (Typ.Procname.to_string pname) CFrontend_config.builtin_object_size
let is_std_addressof pname =
(* since std_addressof is a template function, matching it requires QualifiedCppName *)
QualifiedCppName.Match.match_qualifiers CFrontend_config.std_addressof
(Typ.Procname.get_qualifiers pname)
let is_replace_with_deref_first_arg pname =
String.equal (Typ.Procname.to_string pname) CFrontend_config.replace_with_deref_first_arg_attr
let is_modeled_builtin funct = String.equal funct CFrontend_config.builtin_memset_chk
let is_modeled_attribute attr_name =
List.mem ~equal:String.equal CFrontend_config.modeled_function_attributes attr_name
let is_assert_log_s funct =
String.equal funct CFrontend_config.assert_rtn
|| String.equal funct CFrontend_config.assert_fail
|| String.equal funct CFrontend_config.fbAssertWithSignalAndLogFunctionHelper
|| String.is_substring ~substring:CFrontend_config.google_MakeCheckOpString funct
let is_assert_log_method m = String.equal m CFrontend_config.google_LogMessageFatal
let is_handleFailureInMethod funct =
String.equal funct CFrontend_config.handleFailureInMethod
|| String.equal funct CFrontend_config.handleFailureInFunction
(** If the function is a builtin model, return the model, otherwise return the function *)
let is_assert_log pname =
match pname with
| Typ.Procname.ObjC_Cpp _ ->
is_assert_log_method (Typ.Procname.to_string pname)
| Typ.Procname.C _ ->
is_assert_log_s (Typ.Procname.to_string pname)
| _ ->
false
let get_predefined_ms_method condition class_name method_name method_kind mk_procname arguments
return_type attributes builtin =
if condition then
let procname =
match builtin with
| Some procname ->
procname
| None ->
mk_procname class_name method_name method_kind
in
let ms =
CMethodSignature.mk procname None arguments return_type attributes
(CAst_utils.dummy_source_range ())
ClangMethodKind.C_FUNCTION None None None `None
in
Some ms
else None
let get_predefined_ms_stringWithUTF8String class_name method_name mk_procname =
let condition =
class_equal class_name CFrontend_config.nsstring_cl
&& String.equal method_name CFrontend_config.string_with_utf8_m
in
let id_type = CType_to_sil_type.type_of_builtin_type_kind `ObjCId in
let char_star_type =
let char_type = CType_to_sil_type.type_of_builtin_type_kind ~is_const:true `Char_S in
Typ.Tptr (char_type, Typ.Pk_pointer) |> Typ.mk ~quals:(Typ.mk_type_quals ())
in
let param_name = Mangled.from_string "x" in
let params = [CMethodSignature.mk_param_type param_name char_star_type] in
get_predefined_ms_method condition class_name method_name Typ.Procname.ObjC_Cpp.ObjCClassMethod
mk_procname params (id_type, Annot.Item.empty) [] None
let get_predefined_ms_is_kind_of_class class_name method_name mk_procname =
let condition = String.equal method_name CFrontend_config.is_kind_of_class in
let class_type = CType_to_sil_type.type_of_builtin_type_kind `ObjCClass in
let name = Mangled.from_string CFrontend_config.self in
let params = [CMethodSignature.mk_param_type name class_type] in
let bool_type = CType_to_sil_type.type_of_builtin_type_kind `Bool in
get_predefined_ms_method condition class_name method_name
Typ.Procname.ObjC_Cpp.ObjCInstanceMethod mk_procname params (bool_type, Annot.Item.empty) []
(Some BuiltinDecl.__instanceof)
let get_predefined_model_method_signature class_name method_name mk_procname =
let next_predefined f = function Some _ as x -> x | None -> f method_name mk_procname in
None
|> next_predefined (get_predefined_ms_stringWithUTF8String class_name)
|> next_predefined (get_predefined_ms_is_kind_of_class class_name)