(***********************************************************************) (* *) (* 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 = (* Do not expand abbreviations here, to avoid bringing in external interfaces that are not strictly necessary. This results in sligthly suboptimal code. The correct way of doing this would be to consult the type definition (as in array_element_kind below) to return false if exp.exp_type is a variant or record type. *) match ((Ctype.repr exp.exp_type).desc, (Ctype.repr base_ty).desc) with (Tconstr(p1, [], _), 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 rec array_element_kind env ty = let ty = Ctype.repr 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} -> begin try array_element_kind env (Ctype.expand_abbrev env p args abbrev ty.level) with Ctype.Cannot_expand -> Pgenarray end | {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 array_ty = Ctype.expand_root arg.exp_env arg.exp_type 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 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 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 | _ -> 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 | 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 then Levent(lam, {lev_loc = exp.exp_loc.Location.loc_start; lev_kind = Lev_before; 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_env = Env.summary exp.exp_env}) else lam (* 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) = transl_function e.exp_loc !Clflags.native_code 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 -> Lprim(transl_prim p args, transl_list args) | 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 (transl_exp arg) (transl_cases pat_expr_list) | Texp_try(body, pat_expr_list) -> let id = Ident.create "exn" 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) -> Lifthenelse(transl_exp cond, transl_exp body, Lstaticfail) | Texp_send(expr, met) -> event_after e (Lsend(Lvar (meth met), 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 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 pl in (Curried, param :: params, Matching.for_function loc (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 (Lvar param) (transl_cases pat_expr_list)) end | _ -> let param = name_pattern "param" pat_expr_list in (Curried, [param], Matching.for_function loc (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"