ocaml/bytecomp/translcore.ml

587 lines
21 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* Translation from typed abstract syntax to lambda terms,
for the core language *)
open Misc
open Asttypes
open Primitive
open Path
open Types
open Typedtree
open Lambda
open Translobj
type error =
Illegal_letrec_pat
| Illegal_letrec_expr
| Free_super_var
exception Error of Location.t * error
(* Translation of primitives *)
let comparisons_table = create_hashtable 11 [
"%equal",
(Pccall{prim_name = "equal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Ceq,
Pfloatcomp Ceq,
Pccall{prim_name = "string_equal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false});
"%notequal",
(Pccall{prim_name = "notequal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Cneq,
Pfloatcomp Cneq,
Pccall{prim_name = "string_notequal"; prim_arity = 2;
prim_alloc = false; prim_native_name = "";
prim_native_float = false});
"%lessthan",
(Pccall{prim_name = "lessthan"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Clt,
Pfloatcomp Clt,
Pccall{prim_name = "lessthan"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false});
"%greaterthan",
(Pccall{prim_name = "greaterthan"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Cgt,
Pfloatcomp Cgt,
Pccall{prim_name = "greaterthan"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false});
"%lessequal",
(Pccall{prim_name = "lessequal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Cle,
Pfloatcomp Cle,
Pccall{prim_name = "lessequal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false});
"%greaterequal",
(Pccall{prim_name = "greaterequal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false},
Pintcomp Cge,
Pfloatcomp Cge,
Pccall{prim_name = "greaterequal"; prim_arity = 2; prim_alloc = false;
prim_native_name = ""; prim_native_float = false})
]
let primitives_table = create_hashtable 31 [
"%identity", Pidentity;
"%field0", Pfield 0;
"%field1", Pfield 1;
"%setfield0", Psetfield(0, true);
"%makeblock", Pmakeblock(0, Immutable);
"%makemutable", Pmakeblock(0, Mutable);
"%raise", Praise;
"%sequand", Psequand;
"%sequor", Psequor;
"%boolnot", Pnot;
"%negint", Pnegint;
"%succint", Poffsetint 1;
"%predint", Poffsetint(-1);
"%addint", Paddint;
"%subint", Psubint;
"%mulint", Pmulint;
"%divint", Pdivint;
"%modint", Pmodint;
"%andint", Pandint;
"%orint", Porint;
"%xorint", Pxorint;
"%lslint", Plslint;
"%lsrint", Plsrint;
"%asrint", Pasrint;
"%eq", Pintcomp Ceq;
"%noteq", Pintcomp Cneq;
"%ltint", Pintcomp Clt;
"%leint", Pintcomp Cle;
"%gtint", Pintcomp Cgt;
"%geint", Pintcomp Cge;
"%incr", Poffsetref(1);
"%decr", Poffsetref(-1);
"%intoffloat", Pintoffloat;
"%floatofint", Pfloatofint;
"%negfloat", Pnegfloat;
"%absfloat", Pabsfloat;
"%addfloat", Paddfloat;
"%subfloat", Psubfloat;
"%mulfloat", Pmulfloat;
"%divfloat", Pdivfloat;
"%eqfloat", Pfloatcomp Ceq;
"%noteqfloat", Pfloatcomp Cneq;
"%ltfloat", Pfloatcomp Clt;
"%lefloat", Pfloatcomp Cle;
"%gtfloat", Pfloatcomp Cgt;
"%gefloat", Pfloatcomp Cge;
"%string_length", Pstringlength;
"%string_safe_get", Pstringrefs;
"%string_safe_set", Pstringsets;
"%string_unsafe_get", Pstringrefu;
"%string_unsafe_set", Pstringsetu;
"%array_length", Parraylength Pgenarray;
"%array_safe_get", Parrayrefs Pgenarray;
"%array_safe_set", Parraysets Pgenarray;
"%array_unsafe_get", Parrayrefu Pgenarray;
"%array_unsafe_set", Parraysetu Pgenarray;
"%obj_size", Parraylength Paddrarray;
"%obj_field", Parrayrefu Paddrarray;
"%obj_set_field", Parraysetu Paddrarray
]
let has_base_type exp base_ty =
let exp_ty =
Ctype.expand_head exp.exp_env (Ctype.correct_levels exp.exp_type) in
match (Ctype.repr exp_ty, Ctype.repr base_ty) with
{desc = Tconstr(p1, _, _)}, {desc = Tconstr(p2, _, _)} -> Path.same p1 p2
| (_, _) -> false
let maybe_pointer arg =
not(has_base_type arg Predef.type_int or has_base_type arg Predef.type_char)
let array_element_kind env ty =
let ty = Ctype.repr (Ctype.expand_head env ty) in
match ty.desc with
Tvar ->
Pgenarray
| Tconstr(p, args, abbrev) ->
if Path.same p Predef.path_int || Path.same p Predef.path_char then
Pintarray
else if Path.same p Predef.path_float then
Pfloatarray
else if Path.same p Predef.path_string
|| Path.same p Predef.path_array then
Paddrarray
else begin
try
match Env.find_type p env with
{type_kind = Type_abstract} ->
Pgenarray
| {type_kind = Type_variant cstrs}
when List.for_all (fun (name, args) -> args = []) cstrs ->
Pintarray
| {type_kind = _} ->
Paddrarray
with Not_found ->
(* This can happen due to e.g. missing -I options,
causing some .cmi files to be unavailable.
Maybe we should emit a warning. *)
Pgenarray
end
| _ ->
Paddrarray
let array_kind arg =
let ty = Ctype.correct_levels arg.exp_type in
let array_ty = Ctype.expand_head arg.exp_env ty in
match (Ctype.repr array_ty).desc with
Tconstr(p, [elt_ty], _) when Path.same p Predef.path_array ->
array_element_kind arg.exp_env elt_ty
| _ ->
fatal_error "Translcore.array_kind"
let prim_makearray =
{ prim_name = "make_vect"; prim_arity = 2; prim_alloc = true;
prim_native_name = ""; prim_native_float = false }
let transl_prim prim args =
try
let (gencomp, intcomp, floatcomp, stringcomp) =
Hashtbl.find comparisons_table prim.prim_name in
begin match args with
[arg1; {exp_desc = Texp_construct({cstr_tag = Cstr_constant _}, _)}] ->
intcomp
| [{exp_desc = Texp_construct({cstr_tag = Cstr_constant _}, _)}; arg2] ->
intcomp
| [arg1; arg2] when has_base_type arg1 Predef.type_int
or has_base_type arg1 Predef.type_char ->
intcomp
| [arg1; arg2] when has_base_type arg1 Predef.type_float ->
floatcomp
| [arg1; arg2] when has_base_type arg1 Predef.type_string ->
stringcomp
| _ ->
gencomp
end
with Not_found ->
try
let p = Hashtbl.find primitives_table prim.prim_name in
(* Try strength reduction based on the type of the argument *)
begin match (p, args) with
(Psetfield(n, _), [arg1; arg2]) -> Psetfield(n, maybe_pointer arg2)
| (Parraylength Pgenarray, [arg]) -> Parraylength(array_kind arg)
| (Parrayrefu Pgenarray, arg1 :: _) -> Parrayrefu(array_kind arg1)
| (Parraysetu Pgenarray, arg1 :: _) -> Parraysetu(array_kind arg1)
| (Parrayrefs Pgenarray, arg1 :: _) -> Parrayrefs(array_kind arg1)
| (Parraysets Pgenarray, arg1 :: _) -> Parraysets(array_kind arg1)
| _ -> p
end
with Not_found ->
Pccall prim
(* Eta-expand a primitive without knowing the types of its arguments *)
let transl_primitive p =
let prim =
try
let (gencomp, intcomp, floatcomp, stringcomp) =
Hashtbl.find comparisons_table p.prim_name in
gencomp
with Not_found ->
try
Hashtbl.find primitives_table p.prim_name
with Not_found ->
Pccall p in
let rec make_params n =
if n <= 0 then [] else Ident.create "prim" :: make_params (n-1) in
let params = make_params p.prim_arity in
Lfunction(Curried, params, Lprim(prim, List.map (fun id -> Lvar id) params))
(* To check the well-formedness of r.h.s. of "let rec" definitions *)
let check_recursive_lambda idlist lam =
let rec check_top = function
Lfunction(kind, params, body) as funct -> true
| Lprim(Pmakeblock(tag, mut), args) -> List.for_all check args
| Lprim(Pmakearray kind, args) -> List.for_all check args
| Llet(str, id, arg, body) -> check arg & check_top body
| Lletrec(bindings, body) ->
List.for_all (fun (id, arg) -> check arg) bindings & check_top body
| Levent (lam, _) -> check_top lam
| _ -> false
and check = function
Lvar _ -> true
| Lconst cst -> true
| Lfunction(kind, params, body) -> true
| Llet(str, id, arg, body) -> check arg & check body
| Lletrec(bindings, body) ->
List.for_all (fun (id, arg) -> check arg) bindings & check body
| Lprim(Pmakeblock(tag, mut), args) -> List.for_all check args
| Lprim(Pmakearray kind, args) -> List.for_all check args
| Levent (lam, _) -> check lam
| lam ->
let fv = free_variables lam in
List.for_all (fun id -> not(IdentSet.mem id fv)) idlist
in check_top lam
(* To propagate structured constants *)
exception Not_constant
let extract_constant = function
Lconst sc -> sc
| _ -> raise Not_constant
let extract_float = function
Const_base(Const_float f) -> f
| _ -> fatal_error "Translcore.extract_float"
(* To find reasonable names for let-bound and lambda-bound idents *)
let rec name_pattern default = function
[] -> Ident.create default
| (p, e) :: rem ->
match p.pat_desc with
Tpat_var id -> id
| Tpat_alias(p, id) -> id
| _ -> name_pattern default rem
(* Insertion of debugging events *)
let event_before exp lam =
if !Clflags.debug && lam <> Lstaticfail
then Levent(lam, {lev_loc = exp.exp_loc.Location.loc_start;
lev_kind = Lev_before;
lev_repr = None;
lev_env = Env.summary exp.exp_env})
else lam
let event_after exp lam =
if !Clflags.debug
then Levent(lam, {lev_loc = exp.exp_loc.Location.loc_end;
lev_kind = Lev_after exp.exp_type;
lev_repr = None;
lev_env = Env.summary exp.exp_env})
else lam
let event_function exp lam =
if !Clflags.debug then
let repr = Some (ref 0) in
let (info, body) = lam repr in
(info,
Levent(body, {lev_loc = exp.exp_loc.Location.loc_start;
lev_kind = Lev_function;
lev_repr = repr;
lev_env = Env.summary exp.exp_env}))
else
lam None
(* Translation of expressions *)
let rec transl_exp e =
match e.exp_desc with
Texp_ident(path, {val_kind = Val_prim p}) ->
transl_primitive p
| Texp_ident(path, {val_kind = Val_anc _}) ->
raise(Error(e.exp_loc, Free_super_var))
| Texp_ident(path, desc) ->
transl_path path
| Texp_constant cst ->
Lconst(Const_base cst)
| Texp_let(rec_flag, pat_expr_list, body) ->
transl_let rec_flag pat_expr_list (event_before body (transl_exp body))
| Texp_function pat_expr_list ->
let ((kind, params), body) =
event_function e
(function repr ->
transl_function e.exp_loc !Clflags.native_code repr pat_expr_list)
in
Lfunction(kind, params, body)
| Texp_apply({exp_desc = Texp_ident(path, {val_kind = Val_prim p})}, args)
when List.length args = p.prim_arity ->
let prim = transl_prim p args in
let lam = Lprim(prim, transl_list args) in
begin match prim with Pccall _ -> event_after e lam | _ -> lam end
| Texp_apply(funct, args) ->
let lam =
match transl_exp funct with
Lsend(lmet, lobj, largs) ->
Lsend(lmet, lobj, largs @ transl_list args)
| Levent(Lsend(lmet, lobj, largs), _) ->
Lsend(lmet, lobj, largs @ transl_list args)
| lexp ->
Lapply(lexp, transl_list args) in
event_after e lam
| Texp_match({exp_desc = Texp_tuple argl} as arg, pat_expr_list) ->
Matching.for_multiple_match e.exp_loc
(transl_list argl) (transl_cases pat_expr_list)
| Texp_match(arg, pat_expr_list) ->
Matching.for_function e.exp_loc None
(transl_exp arg) (transl_cases pat_expr_list)
| Texp_try(body, pat_expr_list) ->
let id = name_pattern "exn" pat_expr_list in
Ltrywith(transl_exp body, id,
Matching.for_trywith (Lvar id) (transl_cases pat_expr_list))
| Texp_tuple el ->
let ll = transl_list el in
begin try
Lconst(Const_block(0, List.map extract_constant ll))
with Not_constant ->
Lprim(Pmakeblock(0, Immutable), ll)
end
| Texp_construct(cstr, args) ->
let ll = transl_list args in
begin match cstr.cstr_tag with
Cstr_constant n ->
Lconst(Const_pointer n)
| Cstr_block n ->
begin try
Lconst(Const_block(n, List.map extract_constant ll))
with Not_constant ->
Lprim(Pmakeblock(n, Immutable), ll)
end
| Cstr_exception path ->
Lprim(Pmakeblock(0, Immutable), transl_path path :: ll)
end
| Texp_record ((lbl1, _) :: _ as lbl_expr_list) ->
let lv = Array.create (Array.length lbl1.lbl_all) Lstaticfail in
List.iter
(fun (lbl, expr) -> lv.(lbl.lbl_pos) <- transl_exp expr)
lbl_expr_list;
let ll = Array.to_list lv in
if List.exists (fun (lbl, expr) -> lbl.lbl_mut = Mutable) lbl_expr_list
then begin
match lbl1.lbl_repres with
Record_regular -> Lprim(Pmakeblock(0, Mutable), ll)
| Record_float -> Lprim(Pmakearray Pfloatarray, ll)
end else begin
try
let cl = List.map extract_constant ll in
match lbl1.lbl_repres with
Record_regular -> Lconst(Const_block(0, cl))
| Record_float ->
Lconst(Const_float_array(List.map extract_float cl))
with Not_constant ->
match lbl1.lbl_repres with
Record_regular -> Lprim(Pmakeblock(0, Immutable), ll)
| Record_float -> Lprim(Pmakearray Pfloatarray, ll)
end
| Texp_field(arg, lbl) ->
let access =
match lbl.lbl_repres with
Record_regular -> Pfield lbl.lbl_pos
| Record_float -> Pfloatfield lbl.lbl_pos in
Lprim(access, [transl_exp arg])
| Texp_setfield(arg, lbl, newval) ->
let access =
match lbl.lbl_repres with
Record_regular -> Psetfield(lbl.lbl_pos, maybe_pointer newval)
| Record_float -> Psetfloatfield lbl.lbl_pos in
Lprim(access, [transl_exp arg; transl_exp newval])
| Texp_array expr_list ->
let kind = array_kind e in
let len = List.length expr_list in
if len <= Config.max_young_wosize then
Lprim(Pmakearray kind, transl_list expr_list)
else begin
let v = Ident.create "makearray" in
let rec fill_fields pos = function
[] ->
Lvar v
| arg :: rem ->
Lsequence(Lprim(Parraysetu kind,
[Lvar v;
Lconst(Const_base(Const_int pos));
transl_exp arg]),
fill_fields (pos+1) rem) in
Llet(Strict, v,
Lprim(Pccall prim_makearray,
[Lconst(Const_base(Const_int len));
transl_exp (List.hd expr_list)]),
fill_fields 1 (List.tl expr_list))
end
| Texp_ifthenelse(cond, ifso, Some ifnot) ->
Lifthenelse(transl_exp cond,
event_before ifso (transl_exp ifso),
event_before ifnot (transl_exp ifnot))
| Texp_ifthenelse(cond, ifso, None) ->
Lifthenelse(transl_exp cond,
event_before ifso (transl_exp ifso),
lambda_unit)
| Texp_sequence(expr1, expr2) ->
Lsequence(transl_exp expr1, event_before expr2 (transl_exp expr2))
| Texp_while(cond, body) ->
Lwhile(transl_exp cond, event_before body (transl_exp body))
| Texp_for(param, low, high, dir, body) ->
Lfor(param, transl_exp low, transl_exp high, dir,
event_before body (transl_exp body))
| Texp_when(cond, body) ->
event_before cond
(Lifthenelse(transl_exp cond, event_before body (transl_exp body),
Lstaticfail))
| Texp_send(expr, met) ->
let met_id =
match met with
Tmeth_name nm -> meth nm
| Tmeth_val id -> id
in
event_after e (Lsend(Lvar met_id, transl_exp expr, []))
| Texp_new cl ->
Lprim(Pfield 0, [transl_path cl])
| Texp_instvar(path_self, path) ->
Lprim(Parrayrefu Paddrarray , [transl_path path_self; transl_path path])
| Texp_setinstvar(path_self, path, expr) ->
transl_setinstvar (transl_path path_self) path expr
| Texp_override(path_self, modifs) ->
let cpy = Ident.create "copy" in
Llet(Strict, cpy, Lapply(oo_prim "copy", [transl_path path_self]),
List.fold_right
(fun (path, expr) rem ->
Lsequence(transl_setinstvar (Lvar cpy) path expr,
rem))
modifs
(Lvar cpy))
| _ ->
fatal_error "Translcore.transl"
and transl_list expr_list =
List.map transl_exp expr_list
and transl_cases pat_expr_list =
List.map
(fun (pat, expr) -> (pat, event_before expr (transl_exp expr)))
pat_expr_list
and transl_tupled_cases patl_expr_list =
List.map (fun (patl, expr) -> (patl, transl_exp expr)) patl_expr_list
and transl_function loc untuplify_fn repr pat_expr_list =
match pat_expr_list with
[pat, ({exp_desc = Texp_function pl} as exp)] ->
let param = name_pattern "param" pat_expr_list in
let ((_, params), body) = transl_function exp.exp_loc false repr pl in
((Curried, param :: params),
Matching.for_function loc None (Lvar param) [pat, body])
| ({pat_desc = Tpat_tuple pl}, _) :: _ when untuplify_fn ->
begin try
let size = List.length pl in
let pats_expr_list =
List.map
(fun (pat, expr) -> (Matching.flatten_pattern size pat, expr))
pat_expr_list in
let params = List.map (fun p -> Ident.create "param") pl in
((Tupled, params),
Matching.for_tupled_function loc params
(transl_tupled_cases pats_expr_list))
with Matching.Cannot_flatten ->
let param = name_pattern "param" pat_expr_list in
((Curried, [param]),
Matching.for_function loc repr (Lvar param)
(transl_cases pat_expr_list))
end
| _ ->
let param = name_pattern "param" pat_expr_list in
((Curried, [param]),
Matching.for_function loc repr (Lvar param)
(transl_cases pat_expr_list))
and transl_let rec_flag pat_expr_list body =
match rec_flag with
Nonrecursive ->
let rec transl = function
[] ->
body
| (pat, expr) :: rem ->
Matching.for_let pat.pat_loc (transl_exp expr) pat (transl rem)
in transl pat_expr_list
| Recursive ->
let idlist =
List.map
(fun (pat, expr) ->
match pat.pat_desc with
Tpat_var id -> id
| _ -> raise(Error(pat.pat_loc, Illegal_letrec_pat)))
pat_expr_list in
let transl_case (pat, expr) id =
let lam = transl_exp expr in
if not (check_recursive_lambda idlist lam) then
raise(Error(expr.exp_loc, Illegal_letrec_expr));
(id, lam) in
Lletrec(List.map2 transl_case pat_expr_list idlist, body)
and transl_setinstvar self var expr =
Lprim(Parraysetu (if maybe_pointer expr then Paddrarray else Pintarray),
[self; transl_path var; transl_exp expr])
(* Compile an exception definition *)
let transl_exception id decl =
Lprim(Pmakeblock(0, Immutable),
[Lconst(Const_base(Const_string(Ident.name id)))])
(* Error report *)
open Format
let report_error = function
Illegal_letrec_pat ->
print_string
"Only variables are allowed as left-hand side of `let rec'"
| Illegal_letrec_expr ->
print_string
"This kind of expression is not allowed as right-hand side of `let rec'"
| Free_super_var ->
print_string
"Ancestor names can only be used to select inherited methods"