(***********************************************************************)
(*                                                                     *)
(*                                OCaml                                *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 1996 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* A variant of the "lambda" code with direct / indirect calls explicit
   and closures explicit too *)

open Asttypes
open Lambda

type function_label = string

type ustructured_constant =
  | Uconst_float of float
  | Uconst_int32 of int32
  | Uconst_int64 of int64
  | Uconst_nativeint of nativeint
  | Uconst_block of int * uconstant list
  | Uconst_float_array of float list
  | Uconst_string of string

and uconstant =
  | Uconst_ref of string * ustructured_constant
  | Uconst_int of int
  | Uconst_ptr of int

type ulambda =
    Uvar of Ident.t
  | Uconst of uconstant
  | Udirect_apply of function_label * ulambda list * Debuginfo.t
  | Ugeneric_apply of ulambda * ulambda list * Debuginfo.t
  | Uclosure of ufunction list * ulambda list
  | Uoffset of ulambda * int
  | Ulet of Ident.t * ulambda * ulambda
  | Uletrec of (Ident.t * ulambda) list * ulambda
  | Uprim of primitive * ulambda list * Debuginfo.t
  | Uswitch of ulambda * ulambda_switch
  | Ustringswitch of ulambda * (string * ulambda) list * ulambda option
  | Ustaticfail of int * ulambda list
  | Ucatch of int * Ident.t list * ulambda * ulambda
  | Utrywith of ulambda * Ident.t * ulambda
  | Uifthenelse of ulambda * ulambda * ulambda
  | Usequence of ulambda * ulambda
  | Uwhile of ulambda * ulambda
  | Ufor of Ident.t * ulambda * ulambda * direction_flag * ulambda
  | Uassign of Ident.t * ulambda
  | Usend of meth_kind * ulambda * ulambda * ulambda list * Debuginfo.t

and ufunction = {
  label  : function_label;
  arity  : int;
  params : Ident.t list;
  body   : ulambda;
  dbg    : Debuginfo.t
}

and ulambda_switch =
  { us_index_consts: int array;
    us_actions_consts : ulambda array;
    us_index_blocks: int array;
    us_actions_blocks: ulambda array}

(* Description of known functions *)

type function_description =
  { fun_label: function_label;          (* Label of direct entry point *)
    fun_arity: int;                     (* Number of arguments *)
    mutable fun_closed: bool;           (* True if environment not used *)
    mutable fun_inline: (Ident.t list * ulambda) option;
    mutable fun_float_const_prop: bool  (* Can propagate FP consts *)
  }

(* Approximation of values *)

type value_approximation =
    Value_closure of function_description * value_approximation
  | Value_tuple of value_approximation array
  | Value_unknown
  | Value_const of uconstant
  | Value_global_field of string * int