infer_clone/infer/src/IR/Typ.ml

(*
 * Copyright (c) 2009-2013, Monoidics ltd.
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *)

(** The Smallfoot Intermediate Language: Types *)

open! IStd
module Hashtbl = Caml.Hashtbl
module L = Logging
module F = Format

module IntegerWidths = struct
  type t = {char_width: int; short_width: int; int_width: int; long_width: int; longlong_width: int}
  [@@deriving compare]

  let java = {char_width= 16; short_width= 16; int_width= 32; long_width= 64; longlong_width= 64}

  module SQLite = SqliteUtils.MarshalledNullableDataNOTForComparison (struct
    type nonrec t = t
  end)

  let load_statement =
    ResultsDatabase.register_statement
      "SELECT integer_type_widths FROM source_files WHERE source_file = :k"


  let load source =
    ResultsDatabase.with_registered_statement load_statement ~f:(fun db load_stmt ->
        SourceFile.SQLite.serialize source
        |> Sqlite3.bind load_stmt 1
        |> SqliteUtils.check_result_code db ~log:"load bind source file" ;
        SqliteUtils.result_single_column_option ~finalize:false ~log:"Typ.IntegerWidths.load" db
          load_stmt
        |> Option.bind ~f:SQLite.deserialize )
end

(** Kinds of integers *)
type ikind =
  | IChar  (** [char] *)
  | ISChar  (** [signed char] *)
  | IUChar  (** [unsigned char] *)
  | IBool  (** [bool] *)
  | IInt  (** [int] *)
  | IUInt  (** [unsigned int] *)
  | IShort  (** [short] *)
  | IUShort  (** [unsigned short] *)
  | ILong  (** [long] *)
  | IULong  (** [unsigned long] *)
  | ILongLong  (** [long long] (or [_int64] on Microsoft Visual C) *)
  | IULongLong  (** [unsigned long long] (or [unsigned int64_] on Microsoft Visual C) *)
  | I128  (** [__int128_t] *)
  | IU128  (** [__uint128_t] *)
[@@deriving compare]

let equal_ikind = [%compare.equal: ikind]

let ikind_to_string = function
  | IChar ->
      "char"
  | ISChar ->
      "signed char"
  | IUChar ->
      "unsigned char"
  | IBool ->
      "_Bool"
  | IInt ->
      "int"
  | IUInt ->
      "unsigned int"
  | IShort ->
      "short"
  | IUShort ->
      "unsigned short"
  | ILong ->
      "long"
  | IULong ->
      "unsigned long"
  | ILongLong ->
      "long long"
  | IULongLong ->
      "unsigned long long"
  | I128 ->
      "__int128_t"
  | IU128 ->
      "__uint128_t"


let width_of_ikind {IntegerWidths.char_width; short_width; int_width; long_width; longlong_width} =
  function
  | IBool ->
      8
  | ISChar | IChar | IUChar ->
      char_width
  | IShort | IUShort ->
      short_width
  | IInt | IUInt ->
      int_width
  | ILong | IULong ->
      long_width
  | ILongLong | IULongLong ->
      longlong_width
  | I128 | IU128 ->
      128


let ikind_is_unsigned = function
  | IBool | IUChar | IUShort | IUInt | IULong | IULongLong | IU128 ->
      true
  | ISChar | IChar | IShort | IInt | ILong | ILongLong | I128 ->
      false


let range_of_ikind =
  let range bits ~unsigned =
    if unsigned then Z.(~$0, shift_left ~$1 bits - ~$1)
    else
      let bound = Z.(shift_left ~$1) (bits - 1) in
      Z.(~-bound, bound - ~$1)
  in
  fun integer_widths x ->
    let bits_for_range = match x with IBool -> 1 | _ -> width_of_ikind integer_widths x in
    range bits_for_range ~unsigned:(ikind_is_unsigned x)


let ikind_is_char = function IChar | ISChar | IUChar -> true | _ -> false

(** Kinds of floating-point numbers *)
type fkind =
  | FFloat  (** [float] *)
  | FDouble  (** [double] *)
  | FLongDouble  (** [long double] *)
[@@deriving compare]

let equal_fkind = [%compare.equal: fkind]

let fkind_to_string = function
  | FFloat ->
      "float"
  | FDouble ->
      "double"
  | FLongDouble ->
      "long double"


(** kind of pointer *)
type ptr_kind =
  | Pk_pointer  (** C/C++, Java, Objc standard/__strong pointer *)
  | Pk_reference  (** C++ reference *)
  | Pk_objc_weak  (** Obj-C __weak pointer *)
  | Pk_objc_unsafe_unretained  (** Obj-C __unsafe_unretained pointer *)
  | Pk_objc_autoreleasing  (** Obj-C __autoreleasing pointer *)
[@@deriving compare]

let equal_ptr_kind = [%compare.equal: ptr_kind]

let ptr_kind_string = function
  | Pk_reference ->
      "&"
  | Pk_pointer ->
      "*"
  | Pk_objc_weak ->
      "__weak *"
  | Pk_objc_unsafe_unretained ->
      "__unsafe_unretained *"
  | Pk_objc_autoreleasing ->
      "__autoreleasing *"


module T = struct
  type type_quals = {is_const: bool; is_restrict: bool; is_volatile: bool} [@@deriving compare]

  (** types for sil (structured) expressions *)
  type t = {desc: desc; quals: type_quals} [@@deriving compare]

  and desc =
    | Tint of ikind  (** integer type *)
    | Tfloat of fkind  (** float type *)
    | Tvoid  (** void type *)
    | Tfun of {no_return: bool}  (** function type with noreturn attribute *)
    | Tptr of t * ptr_kind  (** pointer type *)
    | Tstruct of name  (** structured value type name *)
    | TVar of string  (** type variable (ie. C++ template variables) *)
    | Tarray of {elt: t; length: IntLit.t option; stride: IntLit.t option}
        (** array type with statically fixed length and stride *)
  [@@deriving compare]

  and name =
    | CStruct of QualifiedCppName.t
    | CUnion of QualifiedCppName.t
    | CppClass of QualifiedCppName.t * template_spec_info
    | JavaClass of Mangled.t
    | ObjcClass of QualifiedCppName.t
    | ObjcProtocol of QualifiedCppName.t
  [@@deriving compare]

  and template_arg = TType of t | TInt of Int64.t | TNull | TNullPtr | TOpaque
  [@@deriving compare]

  and template_spec_info =
    | NoTemplate
    | Template of {mangled: string option; args: template_arg list}
  [@@deriving compare]

  let equal_desc = [%compare.equal: desc]

  let equal_quals = [%compare.equal: type_quals]

  let equal = [%compare.equal: t]

  let rec equal_ignore_quals t1 t2 = equal_desc_ignore_quals t1.desc t2.desc

  and equal_desc_ignore_quals d1 d2 =
    match (d1, d2) with
    | Tint ikind1, Tint ikind2 ->
        equal_ikind ikind1 ikind2
    | Tfloat fkind1, Tfloat fkind2 ->
        equal_fkind fkind1 fkind2
    | Tvoid, Tvoid ->
        true
    | Tptr (t1, ptr_kind1), Tptr (t2, ptr_kind2) ->
        equal_ptr_kind ptr_kind1 ptr_kind2 && equal_ignore_quals t1 t2
    | Tarray {elt= t1}, Tarray {elt= t2} ->
        equal_ignore_quals t1 t2
    | _, _ ->
        false
end

include T

let mk_type_quals ?default ?is_const ?is_restrict ?is_volatile () =
  let default_ = {is_const= false; is_restrict= false; is_volatile= false} in
  let mk_aux ?(default = default_) ?(is_const = default.is_const)
      ?(is_restrict = default.is_restrict) ?(is_volatile = default.is_volatile) () =
    {is_const; is_restrict; is_volatile}
  in
  mk_aux ?default ?is_const ?is_restrict ?is_volatile ()


let is_const {is_const} = is_const

let is_restrict {is_restrict} = is_restrict

let is_volatile {is_volatile} = is_volatile

let is_weak_pointer t = match t.desc with Tptr (_, Pk_objc_weak) -> true | _ -> false

let is_strong_pointer t = match t.desc with Tptr (_, Pk_pointer) -> true | _ -> false

let mk ?default ?quals desc : t =
  let default_ = {desc; quals= mk_type_quals ()} in
  let mk_aux ?(default = default_) ?(quals = default.quals) desc = {desc; quals} in
  mk_aux ?default ?quals desc


let mk_array ?default ?quals ?length ?stride elt : t =
  mk ?default ?quals (Tarray {elt; length; stride})


let void = mk Tvoid

let void_star = mk (Tptr (mk Tvoid, Pk_pointer))

let uint = mk (Tint IUInt)

let get_ikind_opt {desc} = match desc with Tint ikind -> Some ikind | _ -> None

(* TODO: size_t should be implementation-dependent. *)
let size_t = IULong

let escape pe = if Pp.equal_print_kind pe.Pp.kind Pp.HTML then Escape.escape_xml else ident

(** Pretty print a type with all the details, using the C syntax. *)
let rec pp_full pe f typ =
  let pp_quals f {quals} =
    if is_const quals then F.pp_print_string f " const " ;
    if is_restrict quals then F.pp_print_string f " __restrict " ;
    if is_volatile quals then F.pp_print_string f " volatile "
  in
  let pp_desc f {desc} =
    match desc with
    | Tstruct tname ->
        (pp_name_c_syntax pe) f tname
    | TVar name ->
        F.pp_print_string f name
    | Tint ik ->
        F.pp_print_string f (ikind_to_string ik)
    | Tfloat fk ->
        F.pp_print_string f (fkind_to_string fk)
    | Tvoid ->
        F.pp_print_string f "void"
    | Tfun {no_return= false} ->
        F.pp_print_string f "_fn_"
    | Tfun {no_return= true} ->
        F.pp_print_string f "_fn_noreturn_"
    | Tptr (({desc= Tarray _ | Tfun _} as typ), pk) ->
        F.fprintf f "%a(%s)" (pp_full pe) typ (ptr_kind_string pk |> escape pe)
    | Tptr (typ, pk) ->
        F.fprintf f "%a%s" (pp_full pe) typ (ptr_kind_string pk |> escape pe)
    | Tarray {elt; length; stride} ->
        let pp_int_opt fmt = function
          | Some x ->
              IntLit.pp fmt x
          | None ->
              F.pp_print_char fmt '_'
        in
        F.fprintf f "%a[%a*%a]" (pp_full pe) elt pp_int_opt length pp_int_opt stride
  in
  F.fprintf f "%a%a" pp_desc typ pp_quals typ


and pp_name_c_syntax pe f = function
  | CStruct name | CUnion name | ObjcClass name | ObjcProtocol name ->
      QualifiedCppName.pp f name
  | CppClass (name, template_spec) ->
      F.fprintf f "%a%a" QualifiedCppName.pp name (pp_template_spec_info pe) template_spec
  | JavaClass name ->
      Mangled.pp f name


and pp_template_spec_info pe f = function
  | NoTemplate ->
      ()
  | Template {args} ->
      let pp_arg_opt f = function
        | TType typ ->
            pp_full pe f typ
        | TInt i ->
            Int64.pp f i
        | TNull ->
            F.pp_print_string f "null"
        | TNullPtr ->
            F.pp_print_string f "NullPtr"
        | TOpaque ->
            F.pp_print_string f "Opaque"
      in
      F.fprintf f "%s%a%s" (escape pe "<") (Pp.comma_seq pp_arg_opt) args (escape pe ">")


(** Pretty print a type. Do nothing by default. *)
let pp pe f te = if Config.print_types then pp_full pe f te else ()

let to_string typ =
  let pp fmt = pp_full Pp.text fmt typ in
  F.asprintf "%t" pp


module Name = struct
  type t = name [@@deriving compare]

  let equal = [%compare.equal: t]

  let hash = Hashtbl.hash

  let qual_name = function
    | CStruct name | CUnion name | ObjcClass name | ObjcProtocol name ->
        name
    | CppClass (name, templ_args) ->
        let template_suffix = F.asprintf "%a" (pp_template_spec_info Pp.text) templ_args in
        QualifiedCppName.append_template_args_to_last name ~args:template_suffix
    | JavaClass _ ->
        QualifiedCppName.empty


  let unqualified_name = function
    | CStruct name | CUnion name | ObjcClass name | ObjcProtocol name ->
        name
    | CppClass (name, _) ->
        name
    | JavaClass _ ->
        QualifiedCppName.empty


  let get_template_spec_info = function CppClass (_, templ_args) -> Some templ_args | _ -> None

  let name n =
    match n with
    | CStruct _ | CUnion _ | CppClass _ | ObjcClass _ | ObjcProtocol _ ->
        qual_name n |> QualifiedCppName.to_qual_string
    | JavaClass name ->
        Mangled.to_string name


  let pp fmt tname =
    let prefix = function
      | CStruct _ ->
          "struct"
      | CUnion _ ->
          "union"
      | CppClass _ | JavaClass _ | ObjcClass _ ->
          "class"
      | ObjcProtocol _ ->
          "protocol"
    in
    F.fprintf fmt "%s %a" (prefix tname) (pp_name_c_syntax Pp.text) tname


  let to_string = F.asprintf "%a" pp

  let is_class = function CppClass _ | JavaClass _ | ObjcClass _ -> true | _ -> false

  let is_union = function CUnion _ -> true | _ -> false

  let is_objc_protocol name = match name with ObjcProtocol _ -> true | _ -> false

  let is_same_type t1 t2 =
    match (t1, t2) with
    | CStruct _, CStruct _
    | CUnion _, CUnion _
    | CppClass _, CppClass _
    | JavaClass _, JavaClass _
    | ObjcClass _, ObjcClass _
    | ObjcProtocol _, ObjcProtocol _ ->
        true
    | _ ->
        false


  module C = struct
    let from_qual_name qual_name = CStruct qual_name

    let from_string name_str = QualifiedCppName.of_qual_string name_str |> from_qual_name

    let union_from_qual_name qual_name = CUnion qual_name
  end

  module Java = struct
    module Split = struct
      (** e.g. {type_name="int"; package=None} for primitive types
      * or {type_name="PrintWriter"; package=Some "java.io"} for objects.
      *)
      type t = {package: string option; type_name: string}

      let make ?package type_name = {type_name; package}

      (** Given a package.class_name string, it looks for the latest dot and split the string
                in two (package, class_name) *)
      let of_string package_classname =
        match String.rsplit2 package_classname ~on:'.' with
        | Some (package, type_name) ->
            {type_name; package= Some package}
        | None ->
            {type_name= package_classname; package= None}


      let package {package} = package

      let type_name {type_name} = type_name

      let java_lang_object = make ~package:"java.lang" "Object"

      let java_lang_string = make ~package:"java.lang" "String"

      let void = make "void"
    end

    let from_string name_str = JavaClass (Mangled.from_string name_str)

    let from_package_class package_name class_name =
      if String.equal package_name "" then from_string class_name
      else from_string (package_name ^ "." ^ class_name)


    let is_class = function JavaClass _ -> true | _ -> false

    let java_io_serializable = from_string "java.io.Serializable"

    let java_lang_class = from_string "java.lang.Class"

    let java_lang_cloneable = from_string "java.lang.Cloneable"

    let java_lang_object = from_string "java.lang.Object"

    let split_typename typename = Split.of_string (name typename)

    let get_outer_class class_name =
      let {Split.package; type_name} = split_typename class_name in
      match String.rsplit2 ~on:'$' type_name with
      | Some (parent_class, _) ->
          Some (from_package_class (Option.value ~default:"" package) parent_class)
      | None ->
          None


    let is_anonymous_inner_class_name class_name =
      let class_name_no_package = Split.type_name (split_typename class_name) in
      match String.rsplit2 class_name_no_package ~on:'$' with
      | Some (_, s) ->
          let is_int =
            try
              ignore (int_of_string (String.strip s)) ;
              true
            with Failure _ -> false
          in
          is_int
      | None ->
          false


    let is_external_classname name_string =
      let {Split.package} = Split.of_string name_string in
      Option.exists ~f:Config.java_package_is_external package


    let is_external t = is_external_classname (name t)
  end

  module Cpp = struct
    let from_qual_name template_spec_info qual_name = CppClass (qual_name, template_spec_info)

    let is_class = function CppClass _ -> true | _ -> false
  end

  module Objc = struct
    let from_qual_name qual_name = ObjcClass qual_name

    let from_string name_str = QualifiedCppName.of_qual_string name_str |> from_qual_name

    let protocol_from_qual_name qual_name = ObjcProtocol qual_name

    let is_class = function ObjcClass _ -> true | _ -> false
  end

  module Set = Caml.Set.Make (struct
    type nonrec t = t

    let compare = compare
  end)
end

(** dump a type with all the details. *)
let d_full (t : t) = L.d_pp_with_pe pp_full t

(** dump a list of types. *)
let d_list (tl : t list) =
  let pp pe = Pp.seq (pp pe) in
  L.d_pp_with_pe pp tl


let name typ = match typ.desc with Tstruct name -> Some name | _ -> None

let unsome s = function
  | Some default_typ ->
      default_typ
  | None ->
      L.internal_error "No default typ in %s@." s ;
      assert false


(** turn a *T into a T. fails if [typ] is not a pointer type *)
let strip_ptr typ = match typ.desc with Tptr (t, _) -> t | _ -> assert false

(** If an array type, return the type of the element.
    If not, return the default type if given, otherwise raise an exception *)
let array_elem default_opt typ =
  match typ.desc with Tarray {elt} -> elt | _ -> unsome "array_elem" default_opt


let is_class_of_kind check_fun typ =
  match typ.desc with Tstruct tname -> check_fun tname | _ -> false


let is_objc_class = is_class_of_kind Name.Objc.is_class

let is_cpp_class = is_class_of_kind Name.Cpp.is_class

let is_pointer typ = match typ.desc with Tptr _ -> true | _ -> false

let is_reference typ = match typ.desc with Tptr (_, Pk_reference) -> true | _ -> false

let is_struct typ = match typ.desc with Tstruct _ -> true | _ -> false

let is_pointer_to_cpp_class typ = match typ.desc with Tptr (t, _) -> is_cpp_class t | _ -> false

let is_pointer_to_void typ = match typ.desc with Tptr ({desc= Tvoid}, _) -> true | _ -> false

let is_pointer_to_int typ = match typ.desc with Tptr ({desc= Tint _}, _) -> true | _ -> false

let is_int typ = match typ.desc with Tint _ -> true | _ -> false

let is_unsigned_int typ = match typ.desc with Tint ikind -> ikind_is_unsigned ikind | _ -> false

let is_char typ = match typ.desc with Tint ikind -> ikind_is_char ikind | _ -> false

let has_block_prefix s =
  match Str.split_delim (Str.regexp_string Config.anonymous_block_prefix) s with
  | _ :: _ :: _ ->
      true
  | _ ->
      false


type typ = t

module Procname = struct
  (** Level of verbosity of some to_string functions. *)
  type detail_level = Verbose | Non_verbose | Simple [@@deriving compare]

  let equal_detail_level = [%compare.equal: detail_level]

  let is_verbose v = match v with Verbose -> true | _ -> false

  module Java = struct
    type kind =
      | Non_Static
          (** in Java, procedures called with invokevirtual, invokespecial, and invokeinterface *)
      | Static  (** in Java, procedures called with invokestatic *)
    [@@deriving compare]

    (* TODO: use Mangled.t here *)
    type java_type = Name.Java.Split.t = {package: string option; type_name: string}
    [@@deriving compare]

    let java_void = {package= None; type_name= "void"}

    (** Type of java procedure names. *)
    type t =
      { method_name: string
      ; parameters: java_type list
      ; class_name: Name.t
      ; return_type: java_type option (* option because constructors have no return type *)
      ; kind: kind }
    [@@deriving compare]

    let make class_name return_type method_name parameters kind =
      {class_name; return_type; method_name; parameters; kind}


    (** A type is a pair (package, type_name) that is translated in a string package.type_name *)
    let pp_type_verbosity verbosity fmt p =
      match p with
      | {package= Some package; type_name} when is_verbose verbosity ->
          F.fprintf fmt "%s.%s" package type_name
      | {type_name} ->
          F.pp_print_string fmt type_name


    (** Given a list of types, it creates a unique string of types separated by commas *)
    let rec pp_param_list verbosity fmt inputList =
      match inputList with
      | [] ->
          ()
      | [head] ->
          pp_type_verbosity verbosity fmt head
      | head :: rest ->
          pp_type_verbosity verbosity fmt head ;
          F.pp_print_string fmt "," ;
          pp_param_list verbosity fmt rest


    let java_type_of_name class_name = Name.Java.Split.of_string (Name.name class_name)

    (** It is the same as java_type_to_string_verbosity, but Java return types are optional because
        of constructors without type *)
    let pp_return_type verbosity fmt j =
      match j.return_type with None -> () | Some typ -> pp_type_verbosity verbosity fmt typ


    let get_class_name j = Name.name j.class_name

    let get_class_type_name j = j.class_name

    let get_simple_class_name j = Name.Java.Split.(j |> get_class_name |> of_string |> type_name)

    let get_package j = Name.Java.Split.(j |> get_class_name |> of_string |> package)

    let get_method j = j.method_name

    let replace_method_name method_name j = {j with method_name}

    let replace_parameters parameters j = {j with parameters}

    let replace_return_type ret_type j = {j with return_type= Some ret_type}

    let get_parameters j = j.parameters

    (** Prints a string of a java procname with the given level of verbosity *)
    let pp ?(withclass = false) verbosity fmt j =
      match verbosity with
      | Verbose | Non_verbose ->
          (* if verbose, then package.class.method(params): rtype,
         else rtype package.class.method(params)
         verbose is used for example to create unique filenames, non_verbose to create reports *)
          let pp_class_name verbosity fmt j =
            pp_type_verbosity verbosity fmt (Name.Java.split_typename j.class_name)
          in
          let separator =
            match (j.return_type, verbosity) with
            | None, _ ->
                ""
            | Some _, Verbose ->
                ":"
            | _ ->
                " "
          in
          if not (equal_detail_level verbosity Verbose) then
            F.fprintf fmt "%a%s" (pp_return_type verbosity) j separator ;
          F.fprintf fmt "%a.%s(%a)" (pp_class_name verbosity) j j.method_name
            (pp_param_list verbosity) j.parameters ;
          if equal_detail_level verbosity Verbose then
            F.fprintf fmt "%s%a" separator (pp_return_type verbosity) j
      | Simple ->
          (* methodname(...) or without ... if there are no parameters *)
          let pp_class_prefix ~withclass verbosity fmt j =
            if withclass then
              F.fprintf fmt "%a." (pp_type_verbosity verbosity)
                (Name.Java.split_typename j.class_name)
          in
          let params = match j.parameters with [] -> "" | _ -> "..." in
          let pp_method_name ~withclass verbosity fmt j =
            if String.equal j.method_name "<init>" then
              F.pp_print_string fmt (get_simple_class_name j)
            else F.fprintf fmt "%a%s" (pp_class_prefix ~withclass verbosity) j j.method_name
          in
          F.fprintf fmt "%a(%s)" (pp_method_name ~withclass verbosity) j params


    let get_return_typ pname_java =
      let rec java_from_string = function
        | "" | "void" ->
            mk Tvoid
        | "int" ->
            mk (Tint IInt)
        | "byte" ->
            mk (Tint IShort)
        | "short" ->
            mk (Tint IShort)
        | "boolean" ->
            mk (Tint IBool)
        | "char" ->
            mk (Tint IChar)
        | "long" ->
            mk (Tint ILong)
        | "float" ->
            mk (Tfloat FFloat)
        | "double" ->
            mk (Tfloat FDouble)
        | typ_str when String.contains typ_str '[' ->
            let stripped_typ = String.sub typ_str ~pos:0 ~len:(String.length typ_str - 2) in
            mk (Tptr (mk_array (java_from_string stripped_typ), Pk_pointer))
        | typ_str ->
            mk (Tstruct (Name.Java.from_string typ_str))
      in
      let typ = java_from_string (F.asprintf "%a" (pp_return_type Verbose) pname_java) in
      match typ.desc with Tstruct _ -> mk (Tptr (typ, Pk_pointer)) | _ -> typ


    let is_close {method_name} = String.equal method_name "close"

    let constructor_method_name = "<init>"

    let class_initializer_method_name = "<clinit>"

    let is_class_initializer {method_name} = String.equal method_name class_initializer_method_name

    let get_class_initializer class_name =
      { method_name= class_initializer_method_name
      ; parameters= []
      ; class_name
      ; return_type= Some java_void
      ; kind= Static }


    let is_anonymous_inner_class_constructor {class_name} =
      Name.Java.is_anonymous_inner_class_name class_name


    let is_static {kind} = match kind with Static -> true | _ -> false

    let is_lambda {method_name} = String.is_prefix ~prefix:"lambda$" method_name

    let is_generated {method_name} = String.is_prefix ~prefix:"$" method_name

    let is_access_method {method_name} =
      match String.rsplit2 method_name ~on:'$' with
      | Some ("access", s) ->
          let is_int =
            try
              ignore (int_of_string s) ;
              true
            with Failure _ -> false
          in
          is_int
      | _ ->
          false


    let is_autogen_method {method_name} = String.contains method_name '$'

    (** Check if the proc name has the type of a java vararg.
      Note: currently only checks that the last argument has type Object[]. *)
    let is_vararg {parameters} =
      match List.last parameters with Some {type_name= "java.lang.Object[]"} -> true | _ -> false


    let is_external java_pname =
      let package = get_package java_pname in
      Option.exists ~f:Config.java_package_is_external package
  end

  module Parameter = struct
    (** Type for parameters in clang procnames, [Some name] means the parameter is of type pointer to struct, with [name]
  being the name of the struct, [None] means the parameter is of some other type. *)
    type clang_parameter = Name.t option [@@deriving compare]

    (** Type for parameters in procnames, for java and clang. *)
    type t = JavaParameter of Java.java_type | ClangParameter of clang_parameter
    [@@deriving compare]

    let of_typ typ =
      match typ.T.desc with T.Tptr ({desc= Tstruct name}, Pk_pointer) -> Some name | _ -> None


    let pp_parameters fmt parameters =
      if List.exists ~f:Option.is_some parameters then
        (* the tests rely on the fact that we discard non-pointer-to-struct types for some reason,
           hence the slight re-implementation of [Pp.seq] to avoid building the list of [Some] items
           explicitly *)
        let rec pp_parameters_aux fmt = function
          | [] ->
              ()
          | [Some param] ->
              F.pp_print_string fmt (Name.to_string param)
          | None :: parameters ->
              pp_parameters_aux fmt parameters
          | (Some _ as param_some) :: None :: parameters ->
              pp_parameters_aux fmt (param_some :: parameters)
          | Some param :: (Some _ :: _ as parameters) ->
              F.fprintf fmt "%s," (Name.to_string param) ;
              pp_parameters_aux fmt parameters
        in
        F.fprintf fmt "(%a)" pp_parameters_aux parameters


    let clang_param_of_name class_name : clang_parameter = Some class_name
  end

  module ObjC_Cpp = struct
    type kind =
      | CPPMethod of {mangled: string option}
      | CPPConstructor of {mangled: string option; is_constexpr: bool}
      | CPPDestructor of {mangled: string option}
      | ObjCClassMethod
      | ObjCInstanceMethod
      | ObjCInternalMethod
    [@@deriving compare]

    type t =
      { class_name: Name.t
      ; kind: kind
      ; method_name: string
      ; parameters: Parameter.clang_parameter list
      ; template_args: template_spec_info }
    [@@deriving compare]

    let make class_name method_name kind template_args parameters =
      {class_name; method_name; kind; template_args; parameters}


    let get_class_name objc_cpp = Name.name objc_cpp.class_name

    let get_class_type_name objc_cpp = objc_cpp.class_name

    let get_class_qualifiers objc_cpp = Name.qual_name objc_cpp.class_name

    let objc_method_kind_of_bool is_instance =
      if is_instance then ObjCInstanceMethod else ObjCClassMethod


    let is_objc_constructor method_name =
      String.equal method_name "new" || String.is_prefix ~prefix:"init" method_name


    let is_objc_kind = function
      | ObjCClassMethod | ObjCInstanceMethod | ObjCInternalMethod ->
          true
      | _ ->
          false


    let is_objc_method {kind} = is_objc_kind kind

    let is_objc_dealloc method_name = String.equal method_name "dealloc"

    let is_destructor = function
      | {kind= CPPDestructor _} ->
          true
      | name ->
          is_objc_dealloc name.method_name


    let is_inner_destructor ({method_name} as pname) =
      is_destructor pname
      && String.is_prefix ~prefix:Config.clang_inner_destructor_prefix method_name


    let is_constexpr = function {kind= CPPConstructor {is_constexpr= true}} -> true | _ -> false

    let is_cpp_lambda {method_name} = String.is_substring ~substring:"operator()" method_name

    let is_operator_equal {method_name} = String.is_substring ~substring:"operator=" method_name

    let pp_verbose_kind fmt = function
      | CPPMethod {mangled} | CPPDestructor {mangled} ->
          F.fprintf fmt "(%s)" (Option.value ~default:"" mangled)
      | CPPConstructor {mangled; is_constexpr} ->
          F.fprintf fmt "{%s%s}"
            (Option.value ~default:"" mangled)
            (if is_constexpr then "|constexpr" else "")
      | ObjCClassMethod ->
          F.pp_print_string fmt "class"
      | ObjCInstanceMethod ->
          F.pp_print_string fmt "instance"
      | ObjCInternalMethod ->
          F.pp_print_string fmt "internal"


    let pp verbosity fmt osig =
      match verbosity with
      | Simple ->
          F.pp_print_string fmt osig.method_name
      | Non_verbose ->
          F.fprintf fmt "%s::%s" (Name.name osig.class_name) osig.method_name
      | Verbose ->
          F.fprintf fmt "%s::%s%a%a" (Name.name osig.class_name) osig.method_name
            Parameter.pp_parameters osig.parameters pp_verbose_kind osig.kind


    let get_parameters osig = osig.parameters

    let replace_parameters new_parameters osig = {osig with parameters= new_parameters}
  end

  module C = struct
    (** Type of c procedure names. *)
    type t =
      { name: QualifiedCppName.t
      ; mangled: string option
      ; parameters: Parameter.clang_parameter list
      ; template_args: template_spec_info }
    [@@deriving compare]

    let c name mangled parameters template_args =
      {name; mangled= Some mangled; parameters; template_args}


    let from_string name =
      { name= QualifiedCppName.of_qual_string name
      ; mangled= None
      ; parameters= []
      ; template_args= NoTemplate }


    let pp verbosity fmt {name; mangled; parameters} =
      let plain = QualifiedCppName.to_qual_string name in
      match verbosity with
      | Simple ->
          F.fprintf fmt "%s()" plain
      | Non_verbose ->
          F.pp_print_string fmt plain
      | Verbose ->
          let pp_mangled fmt = function None -> () | Some s -> F.fprintf fmt "{%s}" s in
          F.fprintf fmt "%s%a%a" plain Parameter.pp_parameters parameters pp_mangled mangled


    let get_parameters c = c.parameters

    let replace_parameters new_parameters c = {c with parameters= new_parameters}
  end

  module Block = struct
    (** Type of Objective C block names. *)
    type block_name = string [@@deriving compare]

    type t = {name: block_name; parameters: Parameter.clang_parameter list} [@@deriving compare]

    let make name parameters = {name; parameters}

    let pp verbosity fmt bsig =
      match verbosity with
      | Simple ->
          F.pp_print_string fmt "block"
      | Non_verbose ->
          F.pp_print_string fmt bsig.name
      | Verbose ->
          F.fprintf fmt "%s%a" bsig.name Parameter.pp_parameters bsig.parameters


    let get_parameters block = block.parameters

    let replace_parameters new_parameters block = {block with parameters= new_parameters}
  end

  (** Type of procedure names. *)
  type t =
    | Java of Java.t
    | C of C.t
    | Linters_dummy_method
    | Block of Block.t
    | ObjC_Cpp of ObjC_Cpp.t
    | WithBlockParameters of t * Block.block_name list
  [@@deriving compare]

  let equal = [%compare.equal: t]

  (** hash function for procname *)
  let hash = Hashtbl.hash

  let with_block_parameters base blocks = WithBlockParameters (base, blocks)

  let is_java = function Java _ -> true | _ -> false

  (* TODO: deprecate this unfortunately named function and use is_clang instead *)
  let is_c_method = function ObjC_Cpp _ -> true | _ -> false

  let is_c_function = function C _ -> true | _ -> false

  let is_clang = function
    | ObjC_Cpp name ->
        ObjC_Cpp.is_objc_method name
    | name ->
        is_c_function name


  let is_java_access_method pname =
    match pname with Java java_pname -> Java.is_access_method java_pname | _ -> false


  let is_objc_method procname =
    match procname with ObjC_Cpp name -> ObjC_Cpp.is_objc_method name | _ -> false


  let block_name_of_procname procname =
    match procname with
    | Block block ->
        block.name
    | _ ->
        Logging.die InternalError "Only to be called with Objective-C block names"


  let empty_block = Block {name= ""; parameters= []}

  (** Replace the class name component of a procedure name.
      In case of Java, replace package and class name. *)
  let rec replace_class t (new_class : Name.t) =
    match t with
    | Java j ->
        Java {j with class_name= new_class}
    | ObjC_Cpp osig ->
        ObjC_Cpp {osig with class_name= new_class}
    | WithBlockParameters (base, blocks) ->
        WithBlockParameters (replace_class base new_class, blocks)
    | C _ | Block _ | Linters_dummy_method ->
        t


  let get_class_type_name = function
    | Java java_pname ->
        Some (Java.get_class_type_name java_pname)
    | ObjC_Cpp objc_pname ->
        Some (ObjC_Cpp.get_class_type_name objc_pname)
    | _ ->
        None


  let get_class_name = function
    | Java java_pname ->
        Some (Java.get_class_name java_pname)
    | ObjC_Cpp objc_pname ->
        Some (ObjC_Cpp.get_class_name objc_pname)
    | _ ->
        None


  let is_method_in_objc_protocol t =
    match t with ObjC_Cpp osig -> Name.is_objc_protocol osig.class_name | _ -> false


  let rec objc_cpp_replace_method_name t (new_method_name : string) =
    match t with
    | ObjC_Cpp osig ->
        ObjC_Cpp {osig with method_name= new_method_name}
    | WithBlockParameters (base, blocks) ->
        WithBlockParameters (objc_cpp_replace_method_name base new_method_name, blocks)
    | C _ | Block _ | Linters_dummy_method | Java _ ->
        t


  (** Return the method/function of a procname. *)
  let rec get_method = function
    | ObjC_Cpp name ->
        name.method_name
    | WithBlockParameters (base, _) ->
        get_method base
    | C {name} ->
        QualifiedCppName.to_qual_string name
    | Block {name} ->
        name
    | Java j ->
        j.method_name
    | Linters_dummy_method ->
        "Linters_dummy_method"


  (** Return whether the procname is a block procname. *)
  let is_objc_block = function Block _ -> true | _ -> false

  (** Return the language of the procedure. *)
  let get_language = function
    | ObjC_Cpp _ ->
        Language.Clang
    | C _ ->
        Language.Clang
    | Block _ ->
        Language.Clang
    | Linters_dummy_method ->
        Language.Clang
    | WithBlockParameters _ ->
        Language.Clang
    | Java _ ->
        Language.Java


  (** [is_constructor pname] returns true if [pname] is a constructor *)
  let is_constructor = function
    | Java js ->
        String.equal js.method_name Java.constructor_method_name
    | ObjC_Cpp {kind= CPPConstructor _} ->
        true
    | ObjC_Cpp {kind; method_name} when ObjC_Cpp.is_objc_kind kind ->
        ObjC_Cpp.is_objc_constructor method_name
    | _ ->
        false


  (** [is_infer_undefined pn] returns true if [pn] is a special Infer undefined proc *)
  let is_infer_undefined pn =
    match pn with
    | Java j ->
        let regexp = Str.regexp_string "com.facebook.infer.builtins.InferUndefined" in
        Str.string_match regexp (Java.get_class_name j) 0
    | _ ->
        (* TODO: add cases for obj-c, c, c++ *)
        false


  let get_global_name_of_initializer = function
    | C {name}
      when String.is_prefix ~prefix:Config.clang_initializer_prefix
             (QualifiedCppName.to_qual_string name) ->
        let name_str = QualifiedCppName.to_qual_string name in
        let prefix_len = String.length Config.clang_initializer_prefix in
        Some (String.sub name_str ~pos:prefix_len ~len:(String.length name_str - prefix_len))
    | _ ->
        None


  (** Very verbose representation of an existing Procname.t *)
  let rec pp_unique_id fmt = function
    | Java j ->
        Java.pp Verbose fmt j
    | C osig ->
        C.pp Verbose fmt osig
    | ObjC_Cpp osig ->
        ObjC_Cpp.pp Verbose fmt osig
    | Block bsig ->
        Block.pp Verbose fmt bsig
    | WithBlockParameters (base, []) ->
        pp_unique_id fmt base
    | WithBlockParameters (base, (_ :: _ as blocks)) ->
        pp_unique_id fmt base ;
        F.pp_print_string fmt "_" ;
        Pp.seq ~sep:"_" F.pp_print_string fmt blocks
    | Linters_dummy_method ->
        F.pp_print_string fmt "Linters_dummy_method"


  let to_unique_id proc_name = F.asprintf "%a" pp_unique_id proc_name

  (** Convert a proc name to a string for the user to see *)
  let rec pp fmt = function
    | Java j ->
        Java.pp Non_verbose fmt j
    | C osig ->
        C.pp Non_verbose fmt osig
    | ObjC_Cpp osig ->
        ObjC_Cpp.pp Non_verbose fmt osig
    | Block bsig ->
        Block.pp Non_verbose fmt bsig
    | WithBlockParameters (base, []) ->
        pp fmt base
    | WithBlockParameters (base, (_ :: _ as blocks)) ->
        pp fmt base ;
        F.pp_print_string fmt "_" ;
        Pp.seq ~sep:"_" F.pp_print_string fmt blocks
    | Linters_dummy_method ->
        pp_unique_id fmt Linters_dummy_method


  let to_string proc_name = F.asprintf "%a" pp proc_name

  (** Convenient representation of a procname for external tools (e.g. eclipse plugin) *)
  let rec pp_simplified_string ?(withclass = false) fmt = function
    | Java j ->
        Java.pp ~withclass Simple fmt j
    | C osig ->
        C.pp Simple fmt osig
    | ObjC_Cpp osig ->
        ObjC_Cpp.pp Simple fmt osig
    | Block bsig ->
        Block.pp Simple fmt bsig
    | WithBlockParameters (base, _) ->
        pp_simplified_string fmt base
    | Linters_dummy_method ->
        pp_unique_id fmt Linters_dummy_method


  let to_simplified_string ?withclass proc_name =
    F.asprintf "%a" (pp_simplified_string ?withclass) proc_name


  let from_string_c_fun func = C (C.from_string func)

  let java_inner_class_prefix_regex = Str.regexp "\\$[0-9]+"

  let hashable_name proc_name =
    match proc_name with
    | Java pname -> (
        (* Strip autogenerated anonymous inner class numbers in order to keep the bug hash
           invariant when introducing new anonymous classes *)
        let name = F.asprintf "%a" (Java.pp ~withclass:true Simple) pname in
        match Str.search_forward java_inner_class_prefix_regex name 0 with
        | _ ->
            Str.global_replace java_inner_class_prefix_regex "$_" name
        | exception Caml.Not_found ->
            name )
    | ObjC_Cpp m when ObjC_Cpp.is_objc_method m ->
        (* In Objective C, the list of parameters is part of the method name. To prevent the bug
           hash to change when a parameter is introduced or removed, only the part of the name
           before the first colon is used for the bug hash *)
        let name = F.asprintf "%a" (pp_simplified_string ~withclass:true) proc_name in
        List.hd_exn (String.split_on_chars name ~on:[':'])
    | _ ->
        (* Other cases for C and C++ method names *)
        F.asprintf "%a" (pp_simplified_string ~withclass:true) proc_name


  let rec get_parameters procname =
    let clang_param_to_param clang_params =
      List.map ~f:(fun par -> Parameter.ClangParameter par) clang_params
    in
    match procname with
    | Java j ->
        List.map ~f:(fun par -> Parameter.JavaParameter par) (Java.get_parameters j)
    | C osig ->
        clang_param_to_param (C.get_parameters osig)
    | ObjC_Cpp osig ->
        clang_param_to_param (ObjC_Cpp.get_parameters osig)
    | Block bsig ->
        clang_param_to_param (Block.get_parameters bsig)
    | WithBlockParameters (base, _) ->
        get_parameters base
    | Linters_dummy_method ->
        []


  let rec replace_parameters new_parameters procname =
    let params_to_java_params params =
      List.map
        ~f:(fun param ->
          match param with
          | Parameter.JavaParameter par ->
              par
          | _ ->
              Logging.(die InternalError)
                "Expected Java parameters in Java procname, but got Clang parameters" params )
        params
    in
    let params_to_clang_params params =
      List.map
        ~f:(fun param ->
          match param with
          | Parameter.ClangParameter par ->
              par
          | _ ->
              Logging.(die InternalError)
                "Expected Clang parameters in Clang procname, but got Java parameters" params )
        params
    in
    match procname with
    | Java j ->
        Java (Java.replace_parameters (params_to_java_params new_parameters) j)
    | C osig ->
        C (C.replace_parameters (params_to_clang_params new_parameters) osig)
    | ObjC_Cpp osig ->
        ObjC_Cpp (ObjC_Cpp.replace_parameters (params_to_clang_params new_parameters) osig)
    | Block bsig ->
        Block (Block.replace_parameters (params_to_clang_params new_parameters) bsig)
    | WithBlockParameters (base, blocks) ->
        WithBlockParameters (replace_parameters new_parameters base, blocks)
    | Linters_dummy_method ->
        procname


  let parameter_of_name procname class_name =
    match procname with
    | Java _ ->
        Parameter.JavaParameter (Java.java_type_of_name class_name)
    | _ ->
        Parameter.ClangParameter (Parameter.clang_param_of_name class_name)


  let describe f pn =
    let name = hashable_name pn in
    match String.lsplit2 ~on:'<' name with
    | Some (name_without_template, _template_part) ->
        F.pp_print_string f name_without_template
    | None ->
        F.pp_print_string f name


  module Hashable = struct
    type nonrec t = t

    let equal = equal

    let hash = hash
  end

  module Hash = Hashtbl.Make (Hashable)

  module Map = PrettyPrintable.MakePPMap (struct
    type nonrec t = t

    let compare = compare

    let pp = pp
  end)

  module Set = PrettyPrintable.MakePPSet (struct
    type nonrec t = t

    let compare = compare

    let pp = pp
  end)

  let get_qualifiers pname =
    match pname with
    | C {name} ->
        name
    | ObjC_Cpp objc_cpp ->
        ObjC_Cpp.get_class_qualifiers objc_cpp
        |> QualifiedCppName.append_qualifier ~qual:objc_cpp.method_name
    | _ ->
        QualifiedCppName.empty


  (** Convert a proc name to a filename *)
  let to_filename ?crc_only pname =
    (* filenames for clang procs are REVERSED qualifiers with '#' as separator *)
    let pp_rev_qualified fmt pname =
      let rev_qualifiers = get_qualifiers pname |> QualifiedCppName.to_rev_list in
      Pp.seq ~sep:"#" F.pp_print_string fmt rev_qualifiers
    in
    let proc_id =
      match pname with
      | C {parameters; mangled} ->
          let pp_mangled fmt = function
            | None ->
                ()
            | Some mangled ->
                F.fprintf fmt "#%s" mangled
          in
          F.asprintf "%a%a%a" pp_rev_qualified pname Parameter.pp_parameters parameters pp_mangled
            mangled
      | ObjC_Cpp objc_cpp ->
          F.asprintf "%a%a#%a" pp_rev_qualified pname Parameter.pp_parameters objc_cpp.parameters
            ObjC_Cpp.pp_verbose_kind objc_cpp.kind
      | _ ->
          F.asprintf "%a" pp_unique_id pname
    in
    Escape.escape_filename @@ DB.append_crc_cutoff ?crc_only proc_id


  module SQLite = struct
    module T = struct
      type nonrec t = t

      let compare = compare

      let hash = hash

      let sexp_of_t p = Sexp.Atom (F.asprintf "%a" pp p)
    end

    module Serializer = SqliteUtils.MarshalledDataForComparison (T)

    let pname_to_key = Base.Hashtbl.create (module T)

    let serialize pname =
      let default () = Serializer.serialize pname in
      Base.Hashtbl.find_or_add pname_to_key pname ~default


    let deserialize = Serializer.deserialize

    let clear_cache () = Base.Hashtbl.clear pname_to_key
  end

  module SQLiteList = SqliteUtils.MarshalledDataNOTForComparison (struct
    type nonrec t = t list
  end)
end

module Fieldname = struct
  type t = Clang of {class_name: Name.t; field_name: string} | Java of string
  [@@deriving compare]

  let equal = [%compare.equal: t]

  module T = struct
    type nonrec t = t

    let compare = compare
  end

  module Set = Caml.Set.Make (T)
  module Map = Caml.Map.Make (T)

  (** Convert a fieldname to a string. *)
  let to_string = function Java fname -> fname | Clang {field_name} -> field_name

  (** Convert a fieldname to a simplified string with at most one-level path. *)
  let to_simplified_string fn =
    let s = to_string fn in
    match String.rsplit2 s ~on:'.' with
    | Some (s1, s2) -> (
      match String.rsplit2 s1 ~on:'.' with Some (_, s4) -> s4 ^ "." ^ s2 | _ -> s )
    | _ ->
        s


  let to_full_string fname =
    match fname with
    | Clang {class_name; field_name} ->
        Name.to_string class_name ^ "::" ^ field_name
    | _ ->
        to_string fname


  (** Convert a fieldname to a flat string without path. *)
  let to_flat_string fn =
    let s = to_string fn in
    match String.rsplit2 s ~on:'.' with Some (_, s2) -> s2 | _ -> s


  let pp f = function Java field_name | Clang {field_name} -> Format.pp_print_string f field_name

  let clang_get_qual_class = function
    | Clang {class_name} ->
        Some (Name.qual_name class_name)
    | _ ->
        None


  module Clang = struct
    let from_class_name class_name field_name = Clang {class_name; field_name}
  end

  module Java = struct
    let from_string n = Java n

    let is_captured_parameter field_name =
      match field_name with
      | Java _ ->
          String.is_prefix ~prefix:"val$" (to_flat_string field_name)
      | Clang _ ->
          false


    let get_class fn =
      let fn = to_string fn in
      let ri = String.rindex_exn fn '.' in
      String.slice fn 0 ri


    let get_field fn =
      let fn = to_string fn in
      let ri = 1 + String.rindex_exn fn '.' in
      String.slice fn ri 0


    let is_outer_instance fn =
      let fn = to_string fn in
      let fn_len = String.length fn in
      fn_len <> 0
      &&
      let this = ".this$" in
      let last_char = fn.[fn_len - 1] in
      (last_char >= '0' && last_char <= '9')
      && String.is_suffix fn ~suffix:(this ^ String.of_char last_char)
  end
end

module Struct = struct
  type field = Fieldname.t * T.t * Annot.Item.t [@@deriving compare]

  type fields = field list

  (** Type for a structured value. *)
  type t =
    { fields: fields  (** non-static fields *)
    ; statics: fields  (** static fields *)
    ; supers: Name.t list  (** superclasses *)
    ; methods: Procname.t list  (** methods defined *)
    ; exported_objc_methods: Procname.t list  (** methods in ObjC interface, subset of [methods] *)
    ; annots: Annot.Item.t  (** annotations *) }

  type lookup = Name.t -> t option

  let pp_field pe f (field_name, typ, ann) =
    F.fprintf f "@\n\t\t%a %a %a" (pp_full pe) typ Fieldname.pp field_name Annot.Item.pp ann


  let pp pe name f {fields; supers; methods; exported_objc_methods; annots} =
    if Config.debug_mode then
      (* change false to true to print the details of struct *)
      F.fprintf f
        "%a @\n\
         \tfields: {%a@\n\
         \t}@\n\
         \tsupers: {%a@\n\
         \t}@\n\
         \tmethods: {%a@\n\
         \t}@\n\
         \texported_obj_methods: {%a@\n\
         \t}@\n\
         \tannots: {%a@\n\
         \t}"
        Name.pp name
        (Pp.seq (pp_field pe))
        fields
        (Pp.seq (fun f n -> F.fprintf f "@\n\t\t%a" Name.pp n))
        supers
        (Pp.seq (fun f m -> F.fprintf f "@\n\t\t%a" Procname.pp m))
        methods
        (Pp.seq (fun f m -> F.fprintf f "@\n\t\t%a" Procname.pp m))
        exported_objc_methods Annot.Item.pp annots
    else Name.pp f name


  let internal_mk_struct ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots
      () =
    let default_ =
      { fields= []
      ; statics= []
      ; methods= []
      ; exported_objc_methods= []
      ; supers= []
      ; annots= Annot.Item.empty }
    in
    let mk_struct_ ?(default = default_) ?(fields = default.fields) ?(statics = default.statics)
        ?(methods = default.methods) ?(exported_objc_methods = default.exported_objc_methods)
        ?(supers = default.supers) ?(annots = default.annots) () =
      {fields; statics; methods; exported_objc_methods; supers; annots}
    in
    mk_struct_ ?default ?fields ?statics ?methods ?exported_objc_methods ?supers ?annots ()


  (** the element typ of the final extensible array in the given typ, if any *)
  let rec get_extensible_array_element_typ ~lookup (typ : T.t) =
    match typ.desc with
    | Tarray {elt} ->
        Some elt
    | Tstruct name -> (
      match lookup name with
      | Some {fields} -> (
        match List.last fields with
        | Some (_, fld_typ, _) ->
            get_extensible_array_element_typ ~lookup fld_typ
        | None ->
            None )
      | None ->
          None )
    | _ ->
        None


  (** If a struct type with field f, return the type of f. If not, return the default *)
  let fld_typ ~lookup ~default fn (typ : T.t) =
    match typ.desc with
    | Tstruct name -> (
      match lookup name with
      | Some {fields} ->
          List.find ~f:(fun (f, _, _) -> Fieldname.equal f fn) fields
          |> Option.value_map ~f:snd3 ~default
      | None ->
          default )
    | _ ->
        default


  let get_field_type_and_annotation ~lookup fn (typ : T.t) =
    match typ.desc with
    | Tstruct name | Tptr ({desc= Tstruct name}, _) -> (
      match lookup name with
      | Some {fields; statics} ->
          List.find_map
            ~f:(fun (f, t, a) ->
              match Fieldname.equal f fn with true -> Some (t, a) | false -> None )
            (fields @ statics)
      | None ->
          None )
    | _ ->
        None
end