488 lines
17 KiB
OCaml
488 lines
17 KiB
OCaml
(* Translation from typed abstract syntax to lambda terms,
|
|
for the core language *)
|
|
|
|
open Misc
|
|
open Asttypes
|
|
open Primitive
|
|
open Path
|
|
open Typedtree
|
|
open Lambda
|
|
|
|
|
|
type error =
|
|
Illegal_letrec_pat
|
|
| Illegal_letrec_expr
|
|
|
|
exception Error of Location.t * error
|
|
|
|
(* The translation environment maps identifiers bound by patterns
|
|
to lambda-terms, e.g. access paths.
|
|
Identifiers unbound in the environment List.map to themselves. *)
|
|
|
|
(* Compute the access paths to identifiers bound in patterns. *)
|
|
|
|
let identity_env e = e
|
|
|
|
let rec bind_pattern env pat arg mut =
|
|
match pat.pat_desc with
|
|
Tpat_var id ->
|
|
begin match mut with
|
|
Mutable -> (env, fun e -> Llet(id, arg, e))
|
|
| Immutable -> (add_env id arg env, identity_env)
|
|
end
|
|
| Tpat_alias(pat, id) ->
|
|
let (ext_env, bind) = bind_pattern env pat arg mut in
|
|
begin match mut with
|
|
Mutable -> (ext_env, fun e -> Llet(id, arg, bind e))
|
|
| Immutable -> (add_env id arg ext_env, bind)
|
|
end
|
|
| Tpat_tuple patl ->
|
|
begin match arg with
|
|
Lprim(Pmakeblock _, argl) -> bind_patterns env patl argl
|
|
| _ -> bind_pattern_list env patl arg mut 0
|
|
end
|
|
| Tpat_construct(cstr, patl) ->
|
|
begin match cstr.cstr_tag with
|
|
Cstr_constant _ -> (env, identity_env)
|
|
| Cstr_block _ -> bind_pattern_list env patl arg mut 0
|
|
| Cstr_exception _ -> bind_pattern_list env patl arg mut 1
|
|
end
|
|
| Tpat_record lbl_pat_list ->
|
|
bind_label_pattern env lbl_pat_list arg mut
|
|
| _ ->
|
|
(env, identity_env)
|
|
|
|
and bind_pattern_list env patl arg mut pos =
|
|
match patl with
|
|
[] -> (env, identity_env)
|
|
| pat :: rem ->
|
|
let (env1, bind1) =
|
|
bind_pattern env pat (Lprim(Pfield pos, [arg])) mut in
|
|
let (env2, bind2) =
|
|
bind_pattern_list env1 rem arg mut (pos+1) in
|
|
(env2, fun e -> bind1(bind2 e))
|
|
|
|
and bind_label_pattern env patl arg mut =
|
|
match patl with
|
|
[] -> (env, identity_env)
|
|
| (lbl, pat) :: rem ->
|
|
let mut1 =
|
|
match lbl.lbl_mut with Mutable -> Mutable | Immutable -> mut in
|
|
let access =
|
|
match lbl.lbl_repres with
|
|
Record_regular -> Pfield lbl.lbl_pos
|
|
| Record_float -> Pfloatfield lbl.lbl_pos in
|
|
let (env1, bind1) =
|
|
bind_pattern env pat (Lprim(access, [arg])) mut1 in
|
|
let (env2, bind2) =
|
|
bind_label_pattern env1 rem arg mut in
|
|
(env2, fun e -> bind1(bind2 e))
|
|
|
|
and bind_patterns env patl argl =
|
|
match (patl, argl) with
|
|
([], []) -> (env, identity_env)
|
|
| (pat1::patl, arg1::argl) ->
|
|
let (env1, bind1) = bind_pattern env pat1 arg1 Immutable in
|
|
let (env2, bind2) = bind_patterns env1 patl argl in
|
|
(env2, fun e -> bind1(bind2 e))
|
|
| (_, _) ->
|
|
fatal_error "Translcore.bind_patterns"
|
|
|
|
(* 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;
|
|
"%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;
|
|
"%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 same_base_type ty1 ty2 =
|
|
match (Ctype.repr ty1, Ctype.repr ty2) with
|
|
(Tconstr(p1, []), Tconstr(p2, [])) -> Path.same p1 p2
|
|
| (_, _) -> false
|
|
|
|
let maybe_pointer arg =
|
|
not(same_base_type arg.exp_type Predef.type_int or
|
|
same_base_type arg.exp_type Predef.type_char)
|
|
|
|
let array_kind arg =
|
|
match Ctype.repr arg.exp_type with
|
|
Tconstr(p, [ty]) ->
|
|
begin match Ctype.repr ty with
|
|
Tvar v -> Pgenarray
|
|
| Tconstr(p, _) ->
|
|
if Path.same p Predef.path_int or Path.same p Predef.path_char then
|
|
Pintarray
|
|
else if Path.same p Predef.path_float then
|
|
Pfloatarray
|
|
else
|
|
Paddrarray
|
|
| _ -> Paddrarray
|
|
end
|
|
| _ -> fatal_error "Translcore.array_kind"
|
|
|
|
let transl_prim prim args =
|
|
try
|
|
let (gencomp, intcomp, floatcomp, stringcomp) =
|
|
Hashtbl.find comparisons_table prim.prim_name in
|
|
match args with
|
|
[arg1; {exp_desc = Texp_construct(cstr, [])}] ->
|
|
intcomp
|
|
| [{exp_desc = Texp_construct(cstr, [])}; arg2] ->
|
|
intcomp
|
|
| [arg1; arg2] when same_base_type arg1.exp_type Predef.type_int
|
|
or same_base_type arg1.exp_type Predef.type_char ->
|
|
intcomp
|
|
| [arg1; arg2] when same_base_type arg1.exp_type Predef.type_float ->
|
|
floatcomp
|
|
| [arg1; arg2] when same_base_type arg1.exp_type Predef.type_string ->
|
|
stringcomp
|
|
| _ ->
|
|
gencomp
|
|
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
|
|
|
|
(* To check the well-formedness of r.h.s. of "let rec" definitions *)
|
|
|
|
let check_recursive_lambda id lam =
|
|
let rec check_top = function
|
|
Lfunction(param, body) as funct -> true
|
|
| Lprim(Pmakeblock tag, args) -> List.for_all check args
|
|
| Llet(id, arg, body) -> check arg & check_top body
|
|
| _ -> false
|
|
and check = function
|
|
Lvar _ -> true
|
|
| Lconst cst -> true
|
|
| Lfunction(param, body) -> true
|
|
| Llet(_, arg, body) -> check arg & check body
|
|
| Lprim(Pmakeblock tag, args) -> List.for_all check args
|
|
| lam -> not(IdentSet.mem id (free_variables lam))
|
|
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 name_pattern default p =
|
|
match p.pat_desc with
|
|
Tpat_var id -> id
|
|
| Tpat_alias(p, id) -> id
|
|
| _ -> Ident.new default
|
|
|
|
let name_pattern_list default = function
|
|
[] -> Ident.new default
|
|
| (p, e) :: _ -> name_pattern default p
|
|
|
|
(* Translation of expressions *)
|
|
|
|
let rec transl_exp env e =
|
|
match e.exp_desc with
|
|
Texp_ident(path, desc) ->
|
|
begin match path with
|
|
Pident id -> transl_access env id
|
|
| _ -> transl_path path
|
|
end
|
|
| Texp_constant cst ->
|
|
Lconst(Const_base cst)
|
|
| Texp_let(rec_flag, pat_expr_list, body) ->
|
|
let (ext_env, add_let) = transl_let env rec_flag pat_expr_list in
|
|
add_let(transl_exp ext_env body)
|
|
| Texp_function pat_expr_list ->
|
|
let param = name_pattern_list "param" pat_expr_list in
|
|
Lfunction(param, Matching.for_function e.exp_loc (Lvar param)
|
|
(transl_cases env (Lvar param) pat_expr_list))
|
|
| Texp_apply({exp_desc = Texp_ident(path, {val_prim = Some p})},
|
|
args) when List.length args = p.prim_arity ->
|
|
Lprim(transl_prim p args, transl_list env args)
|
|
| Texp_apply(funct, args) ->
|
|
Lapply(transl_exp env funct, transl_list env args)
|
|
| Texp_match({exp_desc = Texp_tuple argl} as arg, pat_expr_list) ->
|
|
name_lambda_list (transl_list env argl) (fun paraml ->
|
|
let param = Lprim(Pmakeblock 0, paraml) in
|
|
Matching.for_function e.exp_loc param
|
|
(transl_cases env param pat_expr_list))
|
|
| Texp_match(arg, pat_expr_list) ->
|
|
name_lambda (transl_exp env arg) (fun id ->
|
|
Matching.for_function e.exp_loc (Lvar id)
|
|
(transl_cases env (Lvar id) pat_expr_list))
|
|
| Texp_try(body, pat_expr_list) ->
|
|
let id = Ident.new "exn" in
|
|
Ltrywith(transl_exp env body, id,
|
|
Matching.for_trywith id
|
|
(transl_cases env (Lvar id) pat_expr_list))
|
|
| Texp_tuple el ->
|
|
let ll = transl_list env el in
|
|
begin try
|
|
Lconst(Const_block(0, List.map extract_constant ll))
|
|
with Not_constant ->
|
|
Lprim(Pmakeblock 0, ll)
|
|
end
|
|
| Texp_construct(cstr, args) ->
|
|
let ll = transl_list env 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, ll)
|
|
end
|
|
| Cstr_exception path ->
|
|
Lprim(Pmakeblock 0, transl_path path :: ll)
|
|
end
|
|
| Texp_record ((lbl1, _) :: _ as lbl_expr_list) ->
|
|
let lv = Array.new (Array.length lbl1.lbl_all) Lstaticfail in
|
|
List.iter
|
|
(fun (lbl, expr) -> lv.(lbl.lbl_pos) <- transl_exp env expr)
|
|
lbl_expr_list;
|
|
let ll = Array.to_list lv in
|
|
begin try
|
|
List.iter
|
|
(fun (lbl, expr) -> if lbl.lbl_mut = Mutable then raise Not_constant)
|
|
lbl_expr_list;
|
|
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, 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 env 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 env arg; transl_exp env newval])
|
|
| Texp_array expr_list ->
|
|
Lprim(Pmakearray(array_kind e), transl_list env expr_list)
|
|
| Texp_ifthenelse(cond, ifso, Some ifnot) ->
|
|
Lifthenelse(transl_exp env cond, transl_exp env ifso,
|
|
transl_exp env ifnot)
|
|
| Texp_ifthenelse(cond, ifso, None) ->
|
|
Lifthenelse(transl_exp env cond, transl_exp env ifso, lambda_unit)
|
|
| Texp_sequence(expr1, expr2) ->
|
|
Lsequence(transl_exp env expr1, transl_exp env expr2)
|
|
| Texp_while(cond, body) ->
|
|
Lwhile(transl_exp env cond, transl_exp env body)
|
|
| Texp_for(param, low, high, dir, body) ->
|
|
Lfor(param, transl_exp env low, transl_exp env high, dir,
|
|
transl_exp env body)
|
|
| Texp_when(cond, body) ->
|
|
Lifthenelse(transl_exp env cond, transl_exp env body, Lstaticfail)
|
|
| _ ->
|
|
fatal_error "Translcore.transl"
|
|
|
|
and transl_list env = function
|
|
[] -> []
|
|
| expr :: rem -> transl_exp env expr :: transl_list env rem
|
|
|
|
and transl_cases env param pat_expr_list =
|
|
let transl_case (pat, expr) =
|
|
let (ext_env, bind_fun) = bind_pattern env pat param Immutable in
|
|
(pat, bind_fun(transl_exp ext_env expr)) in
|
|
List.map transl_case pat_expr_list
|
|
|
|
and transl_let env rec_flag pat_expr_list =
|
|
match rec_flag with
|
|
Nonrecursive ->
|
|
let rec transl body_env = function
|
|
[] ->
|
|
(body_env, identity_env)
|
|
| (pat, expr) :: rem ->
|
|
let id = name_pattern "let" pat in
|
|
let (ext_env, bind_fun) =
|
|
bind_pattern body_env pat (Lvar id) Immutable in
|
|
let (final_env, add_let_fun) =
|
|
transl ext_env rem in
|
|
(final_env,
|
|
fun e -> Llet(id, transl_exp env expr,
|
|
Matching.for_let pat.pat_loc id pat
|
|
(bind_fun(add_let_fun e)))) in
|
|
transl env pat_expr_list
|
|
| Recursive ->
|
|
let transl_case (pat, expr) =
|
|
let id =
|
|
match pat.pat_desc with
|
|
Tpat_var id -> id
|
|
| _ -> raise(Error(pat.pat_loc, Illegal_letrec_pat)) in
|
|
let lam = transl_exp env expr in
|
|
if not (check_recursive_lambda id lam) then
|
|
raise(Error(expr.exp_loc, Illegal_letrec_expr));
|
|
(id, lam) in
|
|
let decls =
|
|
List.map transl_case pat_expr_list in
|
|
(env, fun e -> Lletrec(decls, e))
|
|
|
|
(* Compile a primitive definition *)
|
|
|
|
let transl_primitive = function
|
|
None -> fatal_error "Translcore.transl_primitive"
|
|
| Some 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 add_params n params =
|
|
if n >= p.prim_arity
|
|
then Lprim(prim, List.rev params)
|
|
else begin
|
|
let id = Ident.new "prim" in
|
|
Lfunction(id, add_params (n+1) (Lvar id :: params))
|
|
end in
|
|
add_params 0 []
|
|
|
|
(* Compile an exception definition *)
|
|
|
|
let transl_exception id decl =
|
|
Lprim(Pmakeblock 0, [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'"
|