ocaml/bytecomp/lambda.ml

249 lines
7.9 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* 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. *)
(* *)
(***********************************************************************)
(* $Id$ *)
open Misc
open Path
open Asttypes
type primitive =
Pidentity
| Pignore
(* Globals *)
| Pgetglobal of Ident.t
| Psetglobal of Ident.t
(* Operations on heap blocks *)
| Pmakeblock of int * mutable_flag
| Pfield of int
| Psetfield of int * bool
| Pfloatfield of int
| Psetfloatfield of int
(* External call *)
| Pccall of Primitive.description
(* Exceptions *)
| Praise
(* Boolean operations *)
| Psequand | Psequor | Pnot
(* Integer operations *)
| Pnegint | Paddint | Psubint | Pmulint | Pdivint | Pmodint
| Pandint | Porint | Pxorint
| Plslint | Plsrint | Pasrint
| Pintcomp of comparison
| Poffsetint of int
| Poffsetref of int
(* Float operations *)
| Pintoffloat | Pfloatofint
| Pnegfloat | Pabsfloat
| Paddfloat | Psubfloat | Pmulfloat | Pdivfloat
| Pfloatcomp of comparison
(* String operations *)
| Pstringlength | Pstringrefu | Pstringsetu | Pstringrefs | Pstringsets
(* Array operations *)
| Pmakearray of array_kind
| Parraylength of array_kind
| Parrayrefu of array_kind
| Parraysetu of array_kind
| Parrayrefs of array_kind
| Parraysets of array_kind
(* Bitvect operations *)
| Pbittest
and comparison =
Ceq | Cneq | Clt | Cgt | Cle | Cge
and array_kind =
Pgenarray | Paddrarray | Pintarray | Pfloatarray
type structured_constant =
Const_base of constant
| Const_pointer of int
| Const_block of int * structured_constant list
| Const_float_array of string list
type function_kind = Curried | Tupled
type let_kind = Strict | Alias | StrictOpt | Variable
type shared_code = (int * int) list
type lambda =
Lvar of Ident.t
| Lconst of structured_constant
| Lapply of lambda * lambda list
| Lfunction of function_kind * Ident.t list * lambda
| Llet of let_kind * Ident.t * lambda * lambda
| Lletrec of (Ident.t * lambda) list * lambda
| Lprim of primitive * lambda list
| Lswitch of lambda * lambda_switch
| Lstaticfail
| Lcatch of lambda * lambda
| Ltrywith of lambda * Ident.t * lambda
| Lifthenelse of lambda * lambda * lambda
| Lsequence of lambda * lambda
| Lwhile of lambda * lambda
| Lfor of Ident.t * lambda * lambda * direction_flag * lambda
| Lassign of Ident.t * lambda
| Lsend of lambda * lambda * lambda list
| Levent of lambda * lambda_event
| Lifused of Ident.t * lambda
and lambda_switch =
{ sw_numconsts: int;
sw_consts: (int * lambda) list;
sw_numblocks: int;
sw_blocks: (int * lambda) list;
sw_checked: bool }
and lambda_event =
{ lev_loc: int;
lev_kind: lambda_event_kind;
lev_repr: int ref option;
lev_env: Env.summary }
and lambda_event_kind =
Lev_before
| Lev_after of Types.type_expr
| Lev_function
let const_unit = Const_pointer 0
let lambda_unit = Lconst const_unit
let name_lambda arg fn =
match arg with
Lvar id -> fn id
| _ -> let id = Ident.create "let" in Llet(Strict, id, arg, fn id)
let name_lambda_list args fn =
let rec name_list names = function
[] -> fn (List.rev names)
| (Lvar id as arg) :: rem ->
name_list (arg :: names) rem
| arg :: rem ->
let id = Ident.create "let" in
Llet(Strict, id, arg, name_list (Lvar id :: names) rem) in
name_list [] args
module IdentSet =
Set.Make(struct
type t = Ident.t
let compare = compare
end)
let free_variables l =
let fv = ref IdentSet.empty in
let rec freevars = function
Lvar id ->
fv := IdentSet.add id !fv
| Lconst sc -> ()
| Lapply(fn, args) ->
freevars fn; List.iter freevars args
| Lfunction(kind, params, body) ->
freevars body;
List.iter (fun param -> fv := IdentSet.remove param !fv) params
| Llet(str, id, arg, body) ->
freevars arg; freevars body; fv := IdentSet.remove id !fv
| Lletrec(decl, body) ->
freevars body;
List.iter (fun (id, exp) -> freevars exp) decl;
List.iter (fun (id, exp) -> fv := IdentSet.remove id !fv) decl
| Lprim(p, args) ->
List.iter freevars args
| Lswitch(arg, sw) ->
freevars arg;
List.iter (fun (key, case) -> freevars case) sw.sw_consts;
List.iter (fun (key, case) -> freevars case) sw.sw_blocks
| Lstaticfail -> ()
| Lcatch(e1, e2) ->
freevars e1; freevars e2
| Ltrywith(e1, exn, e2) ->
freevars e1; freevars e2; fv := IdentSet.remove exn !fv
| Lifthenelse(e1, e2, e3) ->
freevars e1; freevars e2; freevars e3
| Lsequence(e1, e2) ->
freevars e1; freevars e2
| Lwhile(e1, e2) ->
freevars e1; freevars e2
| Lfor(v, e1, e2, dir, e3) ->
freevars e1; freevars e2; freevars e3; fv := IdentSet.remove v !fv
| Lassign(id, e) ->
fv := IdentSet.add id !fv; freevars e
| Lsend (met, obj, args) ->
List.iter freevars (met::obj::args)
| Levent (lam, evt) ->
freevars lam
| Lifused (v, e) ->
freevars e
in freevars l; !fv
(* Check if an action has a "when" guard *)
let rec is_guarded = function
Lifthenelse(cond, body, Lstaticfail) -> true
| Llet(str, id, lam, body) -> is_guarded body
| Levent(lam, ev) -> is_guarded lam
| _ -> false
(* Translate an access path *)
let rec transl_path = function
Pident id ->
if Ident.global id then Lprim(Pgetglobal id, []) else Lvar id
| Pdot(p, s, pos) ->
Lprim(Pfield pos, [transl_path p])
| Papply(p1, p2) ->
fatal_error "Lambda.transl_path"
(* Compile a sequence of expressions *)
let rec make_sequence fn = function
[] -> lambda_unit
| [x] -> fn x
| x::rem ->
let lam = fn x in Lsequence(lam, make_sequence fn rem)
(* Apply a substitution to a lambda-term.
Assumes that the bound variables of the lambda-term do not
belong to the domain of the substitution.
Assumes that the image of the substitution is out of reach
of the bound variables of the lambda-term (no capture). *)
let subst_lambda s lam =
let rec subst = function
Lvar id as l ->
begin try Ident.find_same id s with Not_found -> l end
| Lconst sc as l -> l
| Lapply(fn, args) -> Lapply(subst fn, List.map subst args)
| Lfunction(kind, params, body) -> Lfunction(kind, params, subst body)
| Llet(str, id, arg, body) -> Llet(str, id, subst arg, subst body)
| Lletrec(decl, body) -> Lletrec(List.map subst_decl decl, subst body)
| Lprim(p, args) -> Lprim(p, List.map subst args)
| Lswitch(arg, sw) ->
Lswitch(subst arg,
{sw with sw_consts = List.map subst_case sw.sw_consts;
sw_blocks = List.map subst_case sw.sw_blocks})
| Lstaticfail -> Lstaticfail
| Lcatch(e1, e2) -> Lcatch(subst e1, subst e2)
| Ltrywith(e1, exn, e2) -> Ltrywith(subst e1, exn, subst e2)
| Lifthenelse(e1, e2, e3) -> Lifthenelse(subst e1, subst e2, subst e3)
| Lsequence(e1, e2) -> Lsequence(subst e1, subst e2)
| Lwhile(e1, e2) -> Lwhile(subst e1, subst e2)
| Lfor(v, e1, e2, dir, e3) -> Lfor(v, subst e1, subst e2, dir, subst e3)
| Lassign(id, e) -> Lassign(id, subst e)
| Lsend (met, obj, args) -> Lsend (subst met, subst obj, List.map subst args)
| Levent (lam, evt) -> Levent (subst lam, evt)
| Lifused (v, e) -> Lifused (v, subst e)
and subst_decl (id, exp) = (id, subst exp)
and subst_case (key, case) = (key, subst case)
in subst lam