(***********************************************************************) (* *) (* OCaml *) (* *) (* Xavier Leroy and Jerome Vouillon, 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. *) (* *) (***********************************************************************) (**** Typing of type definitions ****) open Misc open Asttypes open Parsetree open Primitive open Types open Typetexp type native_repr_kind = Unboxed | Untagged let string_of_native_repr_kind = function | Unboxed -> "unboxed" | Untagged -> "untagged" type error = Repeated_parameter | Duplicate_constructor of string | Too_many_constructors | Duplicate_label of string | Recursive_abbrev of string | Cycle_in_def of string * type_expr | Definition_mismatch of type_expr * Includecore.type_mismatch list | Constraint_failed of type_expr * type_expr | Inconsistent_constraint of Env.t * (type_expr * type_expr) list | Type_clash of Env.t * (type_expr * type_expr) list | Parameters_differ of Path.t * type_expr * type_expr | Null_arity_external | Missing_native_external | Unbound_type_var of type_expr * type_declaration | Not_open_type of Path.t | Not_extensible_type of Path.t | Extension_mismatch of Path.t * Includecore.type_mismatch list | Rebind_wrong_type of Longident.t * Env.t * (type_expr * type_expr) list | Rebind_mismatch of Longident.t * Path.t * Path.t | Rebind_private of Longident.t | Bad_variance of int * (bool * bool * bool) * (bool * bool * bool) | Unavailable_type_constructor of Path.t | Bad_fixed_type of string | Unbound_type_var_ext of type_expr * extension_constructor | Varying_anonymous | Val_in_structure | Invalid_native_repr_attribute_payload of native_repr_kind | Multiple_native_repr_attributes | Cannot_unbox_or_untag_type of native_repr_kind open Typedtree exception Error of Location.t * error (* Enter all declared types in the environment as abstract types *) let enter_type env sdecl id = let decl = { type_params = List.map (fun _ -> Btype.newgenvar ()) sdecl.ptype_params; type_arity = List.length sdecl.ptype_params; type_kind = Type_abstract; type_private = sdecl.ptype_private; type_manifest = begin match sdecl.ptype_manifest with None -> None | Some _ -> Some(Ctype.newvar ()) end; type_variance = List.map (fun _ -> Variance.full) sdecl.ptype_params; type_newtype_level = None; type_loc = sdecl.ptype_loc; type_attributes = sdecl.ptype_attributes; } in Env.add_type ~check:true id decl env let update_type temp_env env id loc = let path = Path.Pident id in let decl = Env.find_type path temp_env in match decl.type_manifest with None -> () | Some ty -> let params = List.map (fun _ -> Ctype.newvar ()) decl.type_params in try Ctype.unify env (Ctype.newconstr path params) ty with Ctype.Unify trace -> raise (Error(loc, Type_clash (env, trace))) (* Determine if a type is (an abbreviation for) the type "float" *) (* We use the Ctype.expand_head_opt version of expand_head to get access to the manifest type of private abbreviations. *) let is_float env ty = match Ctype.repr (Ctype.expand_head_opt env ty) with {desc = Tconstr(p, _, _)} -> Path.same p Predef.path_float | _ -> false (* Determine if a type definition defines a fixed type. (PW) *) let is_fixed_type sd = let rec has_row_var sty = match sty.ptyp_desc with Ptyp_alias (sty, _) -> has_row_var sty | Ptyp_class _ | Ptyp_object (_, Open) | Ptyp_variant (_, Open, _) | Ptyp_variant (_, Closed, Some _) -> true | _ -> false in match sd.ptype_manifest with None -> false | Some sty -> sd.ptype_kind = Ptype_abstract && sd.ptype_private = Private && has_row_var sty (* Set the row variable in a fixed type *) let set_fixed_row env loc p decl = let tm = match decl.type_manifest with None -> assert false | Some t -> Ctype.expand_head env t in let rv = match tm.desc with Tvariant row -> let row = Btype.row_repr row in tm.desc <- Tvariant {row with row_fixed = true}; if Btype.static_row row then Btype.newgenty Tnil else row.row_more | Tobject (ty, _) -> snd (Ctype.flatten_fields ty) | _ -> raise (Error (loc, Bad_fixed_type "is not an object or variant")) in if not (Btype.is_Tvar rv) then raise (Error (loc, Bad_fixed_type "has no row variable")); rv.desc <- Tconstr (p, decl.type_params, ref Mnil) (* Translate one type declaration *) module StringSet = Set.Make(struct type t = string let compare (x:t) y = compare x y end) let make_params env params = let make_param (sty, v) = try (transl_type_param env sty, v) with Already_bound -> raise(Error(sty.ptyp_loc, Repeated_parameter)) in List.map make_param params let transl_labels loc env closed lbls = if lbls = [] then Syntaxerr.ill_formed_ast loc "Records cannot be empty."; let all_labels = ref StringSet.empty in List.iter (fun {pld_name = {txt=name; loc}} -> if StringSet.mem name !all_labels then raise(Error(loc, Duplicate_label name)); all_labels := StringSet.add name !all_labels) lbls; let mk {pld_name=name;pld_mutable=mut;pld_type=arg;pld_loc=loc;pld_attributes=attrs} = let arg = Ast_helper.Typ.force_poly arg in let cty = transl_simple_type env closed arg in {ld_id = Ident.create name.txt; ld_name = name; ld_mutable = mut; ld_type = cty; ld_loc = loc; ld_attributes = attrs} in let lbls = List.map mk lbls in let lbls' = List.map (fun ld -> let ty = ld.ld_type.ctyp_type in let ty = match ty.desc with Tpoly(t,[]) -> t | _ -> ty in {Types.ld_id = ld.ld_id; ld_mutable = ld.ld_mutable; ld_type = ty; ld_loc = ld.ld_loc; ld_attributes = ld.ld_attributes } ) lbls in lbls, lbls' let transl_constructor_arguments loc env closed = function | Pcstr_tuple l -> let l = List.map (transl_simple_type env closed) l in Types.Cstr_tuple (List.map (fun t -> t.ctyp_type) l), Cstr_tuple l | Pcstr_record l -> let lbls, lbls' = transl_labels loc env closed l in Types.Cstr_record lbls', Cstr_record lbls let make_constructor loc env type_path type_params sargs sret_type = match sret_type with | None -> let args, targs = transl_constructor_arguments loc env true sargs in targs, None, args, None | Some sret_type -> (* if it's a generalized constructor we must first narrow and then widen so as to not introduce any new constraints *) let z = narrow () in reset_type_variables (); let args, targs = transl_constructor_arguments loc env false sargs in let tret_type = transl_simple_type env false sret_type in let ret_type = tret_type.ctyp_type in begin match (Ctype.repr ret_type).desc with Tconstr (p', _, _) when Path.same type_path p' -> () | _ -> raise (Error (sret_type.ptyp_loc, Constraint_failed (ret_type, Ctype.newconstr type_path type_params))) end; widen z; targs, Some tret_type, args, Some ret_type let transl_declaration env sdecl id = (* Bind type parameters *) reset_type_variables(); Ctype.begin_def (); let tparams = make_params env sdecl.ptype_params in let params = List.map (fun (cty, _) -> cty.ctyp_type) tparams in let cstrs = List.map (fun (sty, sty', loc) -> transl_simple_type env false sty, transl_simple_type env false sty', loc) sdecl.ptype_cstrs in let (tkind, kind) = match sdecl.ptype_kind with Ptype_abstract -> Ttype_abstract, Type_abstract | Ptype_variant scstrs -> if scstrs = [] then Syntaxerr.ill_formed_ast sdecl.ptype_loc "Variant types cannot be empty."; let all_constrs = ref StringSet.empty in List.iter (fun {pcd_name = {txt = name}} -> if StringSet.mem name !all_constrs then raise(Error(sdecl.ptype_loc, Duplicate_constructor name)); all_constrs := StringSet.add name !all_constrs) scstrs; if List.length (List.filter (fun cd -> cd.pcd_args <> Pcstr_tuple []) scstrs) > (Config.max_tag + 1) then raise(Error(sdecl.ptype_loc, Too_many_constructors)); let make_cstr scstr = let name = Ident.create scstr.pcd_name.txt in let targs, tret_type, args, ret_type = make_constructor scstr.pcd_loc env (Path.Pident id) params scstr.pcd_args scstr.pcd_res in let tcstr = { cd_id = name; cd_name = scstr.pcd_name; cd_args = targs; cd_res = tret_type; cd_loc = scstr.pcd_loc; cd_attributes = scstr.pcd_attributes } in let cstr = { Types.cd_id = name; cd_args = args; cd_res = ret_type; cd_loc = scstr.pcd_loc; cd_attributes = scstr.pcd_attributes } in tcstr, cstr in let tcstrs, cstrs = List.split (List.map make_cstr scstrs) in Ttype_variant tcstrs, Type_variant cstrs | Ptype_record lbls -> let lbls, lbls' = transl_labels sdecl.ptype_loc env true lbls in let rep = if List.for_all (fun l -> is_float env l.Types.ld_type) lbls' then Record_float else Record_regular in Ttype_record lbls, Type_record(lbls', rep) | Ptype_open -> Ttype_open, Type_open in let (tman, man) = match sdecl.ptype_manifest with None -> None, None | Some sty -> let no_row = not (is_fixed_type sdecl) in let cty = transl_simple_type env no_row sty in Some cty, Some cty.ctyp_type in let decl = { type_params = params; type_arity = List.length params; type_kind = kind; type_private = sdecl.ptype_private; type_manifest = man; type_variance = List.map (fun _ -> Variance.full) params; type_newtype_level = None; type_loc = sdecl.ptype_loc; type_attributes = sdecl.ptype_attributes; } in (* Check constraints *) List.iter (fun (cty, cty', loc) -> let ty = cty.ctyp_type in let ty' = cty'.ctyp_type in try Ctype.unify env ty ty' with Ctype.Unify tr -> raise(Error(loc, Inconsistent_constraint (env, tr)))) cstrs; Ctype.end_def (); (* Add abstract row *) if is_fixed_type sdecl then begin let (p, _) = try Env.lookup_type (Longident.Lident(Ident.name id ^ "#row")) env with Not_found -> assert false in set_fixed_row env sdecl.ptype_loc p decl end; (* Check for cyclic abbreviations *) begin match decl.type_manifest with None -> () | Some ty -> if Ctype.cyclic_abbrev env id ty then raise(Error(sdecl.ptype_loc, Recursive_abbrev sdecl.ptype_name.txt)); end; { typ_id = id; typ_name = sdecl.ptype_name; typ_params = tparams; typ_type = decl; typ_cstrs = cstrs; typ_loc = sdecl.ptype_loc; typ_manifest = tman; typ_kind = tkind; typ_private = sdecl.ptype_private; typ_attributes = sdecl.ptype_attributes; } (* Generalize a type declaration *) let generalize_decl decl = List.iter Ctype.generalize decl.type_params; Btype.iter_type_expr_kind Ctype.generalize decl.type_kind; begin match decl.type_manifest with | None -> () | Some ty -> Ctype.generalize ty end (* Check that all constraints are enforced *) module TypeSet = Btype.TypeSet module TypeMap = Btype.TypeMap let rec check_constraints_rec env loc visited ty = let ty = Ctype.repr ty in if TypeSet.mem ty !visited then () else begin visited := TypeSet.add ty !visited; match ty.desc with | Tconstr (path, args, _) -> let args' = List.map (fun _ -> Ctype.newvar ()) args in let ty' = Ctype.newconstr path args' in begin try Ctype.enforce_constraints env ty' with Ctype.Unify _ -> assert false | Not_found -> raise (Error(loc, Unavailable_type_constructor path)) end; if not (Ctype.matches env ty ty') then raise (Error(loc, Constraint_failed (ty, ty'))); List.iter (check_constraints_rec env loc visited) args | Tpoly (ty, tl) -> let _, ty = Ctype.instance_poly false tl ty in check_constraints_rec env loc visited ty | _ -> Btype.iter_type_expr (check_constraints_rec env loc visited) ty end module SMap = Map.Make(String) let check_constraints_labels env visited l pl = let rec get_loc name = function [] -> assert false | pld :: tl -> if name = pld.pld_name.txt then pld.pld_type.ptyp_loc else get_loc name tl in List.iter (fun {Types.ld_id=name; ld_type=ty} -> check_constraints_rec env (get_loc (Ident.name name) pl) visited ty) l let check_constraints env sdecl (_, decl) = let visited = ref TypeSet.empty in begin match decl.type_kind with | Type_abstract -> () | Type_variant l -> let find_pl = function Ptype_variant pl -> pl | Ptype_record _ | Ptype_abstract | Ptype_open -> assert false in let pl = find_pl sdecl.ptype_kind in let pl_index = let foldf acc x = SMap.add x.pcd_name.txt x acc in List.fold_left foldf SMap.empty pl in List.iter (fun {Types.cd_id=name; cd_args; cd_res} -> let {pcd_args; pcd_res; _} = try SMap.find (Ident.name name) pl_index with Not_found -> assert false in begin match cd_args, pcd_args with | Cstr_tuple tyl, Pcstr_tuple styl -> List.iter2 (fun sty ty -> check_constraints_rec env sty.ptyp_loc visited ty) styl tyl | Cstr_record tyl, Pcstr_record styl -> check_constraints_labels env visited tyl styl | _ -> assert false end; match pcd_res, cd_res with | Some sr, Some r -> check_constraints_rec env sr.ptyp_loc visited r | _ -> () ) l | Type_record (l, _) -> let find_pl = function Ptype_record pl -> pl | Ptype_variant _ | Ptype_abstract | Ptype_open -> assert false in let pl = find_pl sdecl.ptype_kind in check_constraints_labels env visited l pl | Type_open -> () end; begin match decl.type_manifest with | None -> () | Some ty -> let sty = match sdecl.ptype_manifest with Some sty -> sty | _ -> assert false in check_constraints_rec env sty.ptyp_loc visited ty end (* If both a variant/record definition and a type equation are given, need to check that the equation refers to a type of the same kind with the same constructors and labels. *) let check_coherence env loc id decl = match decl with { type_kind = (Type_variant _ | Type_record _| Type_open); type_manifest = Some ty } -> begin match (Ctype.repr ty).desc with Tconstr(path, args, _) -> begin try let decl' = Env.find_type path env in let err = if List.length args <> List.length decl.type_params then [Includecore.Arity] else if not (Ctype.equal env false args decl.type_params) then [Includecore.Constraint] else Includecore.type_declarations ~equality:true env (Path.last path) decl' id (Subst.type_declaration (Subst.add_type id path Subst.identity) decl) in if err <> [] then raise(Error(loc, Definition_mismatch (ty, err))) with Not_found -> raise(Error(loc, Unavailable_type_constructor path)) end | _ -> raise(Error(loc, Definition_mismatch (ty, []))) end | _ -> () let check_abbrev env sdecl (id, decl) = check_coherence env sdecl.ptype_loc id decl (* Check that recursion is well-founded *) let check_well_founded env loc path to_check ty = let visited = ref TypeMap.empty in let rec check ty0 exp_nodes ty = let ty = Btype.repr ty in if TypeSet.mem ty exp_nodes then begin (*Format.eprintf "@[%a@]@." Printtyp.raw_type_expr ty;*) if match ty0.desc with | Tconstr (p, _, _) -> Path.same p path | _ -> false then raise (Error (loc, Recursive_abbrev (Path.name path))) else raise (Error (loc, Cycle_in_def (Path.name path, ty0))) end; let (fini, exp_nodes) = try let prev = TypeMap.find ty !visited in if TypeSet.subset exp_nodes prev then (true, exp_nodes) else (false, TypeSet.union exp_nodes prev) with Not_found -> (false, exp_nodes) in let snap = Btype.snapshot () in if fini then () else try visited := TypeMap.add ty exp_nodes !visited; match ty.desc with | Tconstr(p, args, _) when not (TypeSet.is_empty exp_nodes) || to_check p -> let ty' = Ctype.try_expand_once_opt env ty in let ty0 = if TypeSet.is_empty exp_nodes then ty else ty0 in check ty0 (TypeSet.add ty exp_nodes) ty' | _ -> raise Ctype.Cannot_expand with | Ctype.Cannot_expand -> let nodes = if !Clflags.recursive_types && Ctype.is_contractive env ty || match ty.desc with Tobject _ | Tvariant _ -> true | _ -> false then TypeSet.empty else exp_nodes in Btype.iter_type_expr (check ty0 nodes) ty | Ctype.Unify _ -> (* Will be detected by check_recursion *) Btype.backtrack snap in Ctype.wrap_trace_gadt_instances env (check ty TypeSet.empty) ty let check_well_founded_manifest env loc path decl = if decl.type_manifest = None then () else let args = List.map (fun _ -> Ctype.newvar()) decl.type_params in check_well_founded env loc path (Path.same path) (Ctype.newconstr path args) let check_well_founded_decl env loc path decl to_check = let open Btype in let it = {type_iterators with it_type_expr = (fun _ -> check_well_founded env loc path to_check)} in it.it_type_declaration it (Ctype.instance_declaration decl) (* Check for ill-defined abbrevs *) let check_recursion env loc path decl to_check = (* to_check is true for potentially mutually recursive paths. (path, decl) is the type declaration to be checked. *) if decl.type_params = [] then () else let visited = ref [] in let rec check_regular cpath args prev_exp ty = let ty = Ctype.repr ty in if not (List.memq ty !visited) then begin visited := ty :: !visited; match ty.desc with | Tconstr(path', args', _) -> if Path.same path path' then begin if not (Ctype.equal env false args args') then raise (Error(loc, Parameters_differ(cpath, ty, Ctype.newconstr path args))) end (* Attempt to expand a type abbreviation if: 1- [to_check path'] holds (otherwise the expansion cannot involve [path]); 2- we haven't expanded this type constructor before (otherwise we could loop if [path'] is itself a non-regular abbreviation). *) else if to_check path' && not (List.mem path' prev_exp) then begin try (* Attempt expansion *) let (params0, body0, _) = Env.find_type_expansion path' env in let (params, body) = Ctype.instance_parameterized_type params0 body0 in begin try List.iter2 (Ctype.unify env) params args' with Ctype.Unify _ -> raise (Error(loc, Constraint_failed (ty, Ctype.newconstr path' params0))); end; check_regular path' args (path' :: prev_exp) body with Not_found -> () end; List.iter (check_regular cpath args prev_exp) args' | Tpoly (ty, tl) -> let (_, ty) = Ctype.instance_poly ~keep_names:true false tl ty in check_regular cpath args prev_exp ty | _ -> Btype.iter_type_expr (check_regular cpath args prev_exp) ty end in Misc.may (fun body -> let (args, body) = Ctype.instance_parameterized_type ~keep_names:true decl.type_params body in check_regular path args [] body) decl.type_manifest let check_abbrev_recursion env id_loc_list to_check tdecl = let decl = tdecl.typ_type in let id = tdecl.typ_id in check_recursion env (List.assoc id id_loc_list) (Path.Pident id) decl to_check (* Compute variance *) let get_variance ty visited = try TypeMap.find ty !visited with Not_found -> Variance.null let compute_variance env visited vari ty = let rec compute_variance_rec vari ty = (* Format.eprintf "%a: %x@." Printtyp.type_expr ty (Obj.magic vari); *) let ty = Ctype.repr ty in let vari' = get_variance ty visited in if Variance.subset vari vari' then () else let vari = Variance.union vari vari' in visited := TypeMap.add ty vari !visited; let compute_same = compute_variance_rec vari in match ty.desc with Tarrow (_, ty1, ty2, _) -> let open Variance in let v = conjugate vari in let v1 = if mem May_pos v || mem May_neg v then set May_weak true v else v in compute_variance_rec v1 ty1; compute_same ty2 | Ttuple tl -> List.iter compute_same tl | Tconstr (path, tl, _) -> let open Variance in if tl = [] then () else begin try let decl = Env.find_type path env in let cvari f = mem f vari in List.iter2 (fun ty v -> let cv f = mem f v in let strict = cvari Inv && cv Inj || (cvari Pos || cvari Neg) && cv Inv in if strict then compute_variance_rec full ty else let p1 = inter v vari and n1 = inter v (conjugate vari) in let v1 = union (inter covariant (union p1 (conjugate p1))) (inter (conjugate covariant) (union n1 (conjugate n1))) and weak = cvari May_weak && (cv May_pos || cv May_neg) || (cvari May_pos || cvari May_neg) && cv May_weak in let v2 = set May_weak weak v1 in compute_variance_rec v2 ty) tl decl.type_variance with Not_found -> List.iter (compute_variance_rec may_inv) tl end | Tobject (ty, _) -> compute_same ty | Tfield (_, _, ty1, ty2) -> compute_same ty1; compute_same ty2 | Tsubst ty -> compute_same ty | Tvariant row -> let row = Btype.row_repr row in List.iter (fun (_,f) -> match Btype.row_field_repr f with Rpresent (Some ty) -> compute_same ty | Reither (_, tyl, _, _) -> let open Variance in let upper = List.fold_left (fun s f -> set f true s) null [May_pos; May_neg; May_weak] in let v = inter vari upper in List.iter (compute_variance_rec v) tyl | _ -> ()) row.row_fields; compute_same row.row_more | Tpoly (ty, _) -> compute_same ty | Tvar _ | Tnil | Tlink _ | Tunivar _ -> () | Tpackage (_, _, tyl) -> let v = Variance.(if mem Pos vari || mem Neg vari then full else may_inv) in List.iter (compute_variance_rec v) tyl in compute_variance_rec vari ty let make p n i = let open Variance in set May_pos p (set May_neg n (set May_weak n (set Inj i null))) let compute_variance_type env check (required, loc) decl tyl = (* Requirements *) let required = List.map (fun (c,n,i) -> if c || n then (c,n,i) else (true,true,i)) required in (* Prepare *) let params = List.map Btype.repr decl.type_params in let tvl = ref TypeMap.empty in (* Compute occurences in body *) let open Variance in List.iter (fun (cn,ty) -> compute_variance env tvl (if cn then full else covariant) ty) tyl; if check then begin (* Check variance of parameters *) let pos = ref 0 in List.iter2 (fun ty (c, n, i) -> incr pos; let var = get_variance ty tvl in let (co,cn) = get_upper var and ij = mem Inj var in if Btype.is_Tvar ty && (co && not c || cn && not n || not ij && i) then raise (Error(loc, Bad_variance (!pos, (co,cn,ij), (c,n,i))))) params required; (* Check propagation from constrained parameters *) let args = Btype.newgenty (Ttuple params) in let fvl = Ctype.free_variables args in let fvl = List.filter (fun v -> not (List.memq v params)) fvl in (* If there are no extra variables there is nothing to do *) if fvl = [] then () else let tvl2 = ref TypeMap.empty in List.iter2 (fun ty (p,n,i) -> if Btype.is_Tvar ty then () else let v = if p then if n then full else covariant else conjugate covariant in compute_variance env tvl2 v ty) params required; let visited = ref TypeSet.empty in let rec check ty = let ty = Ctype.repr ty in if TypeSet.mem ty !visited then () else let visited' = TypeSet.add ty !visited in visited := visited'; let v1 = get_variance ty tvl in let snap = Btype.snapshot () in let v2 = TypeMap.fold (fun t vt v -> if Ctype.equal env false [ty] [t] then union vt v else v) !tvl2 null in Btype.backtrack snap; let (c1,n1) = get_upper v1 and (c2,n2,_,i2) = get_lower v2 in if c1 && not c2 || n1 && not n2 then if List.memq ty fvl then let code = if not i2 then -2 else if c2 || n2 then -1 else -3 in raise (Error (loc, Bad_variance (code, (c1,n1,false), (c2,n2,false)))) else Btype.iter_type_expr check ty in List.iter (fun (_,ty) -> check ty) tyl; end; List.map2 (fun ty (p, n, i) -> let v = get_variance ty tvl in let tr = decl.type_private in (* Use required variance where relevant *) let concr = decl.type_kind <> Type_abstract (*|| tr = Type_new*) in let (p, n) = if tr = Private || not (Btype.is_Tvar ty) then (p, n) (* set *) else (false, false) (* only check *) and i = concr || i && tr = Private in let v = union v (make p n i) in let v = if not concr then v else if mem Pos v && mem Neg v then full else if Btype.is_Tvar ty then v else union v (if p then if n then full else covariant else conjugate covariant) in if decl.type_kind = Type_abstract && tr = Public then v else set May_weak (mem May_neg v) v) params required let add_false = List.map (fun ty -> false, ty) (* A parameter is constrained if either is is instantiated, or it is a variable appearing in another parameter *) let constrained vars ty = match ty.desc with | Tvar _ -> List.exists (fun tl -> List.memq ty tl) vars | _ -> true let for_constr = function | Types.Cstr_tuple l -> add_false l | Types.Cstr_record l -> List.map (fun {Types.ld_mutable; ld_type} -> (ld_mutable = Mutable, ld_type)) l let compute_variance_gadt env check (required, loc as rloc) decl (tl, ret_type_opt) = match ret_type_opt with | None -> compute_variance_type env check rloc {decl with type_private = Private} (for_constr tl) | Some ret_type -> match Ctype.repr ret_type with | {desc=Tconstr (_, tyl, _)} -> (* let tyl = List.map (Ctype.expand_head env) tyl in *) let tyl = List.map Ctype.repr tyl in let fvl = List.map (Ctype.free_variables ?env:None) tyl in let _ = List.fold_left2 (fun (fv1,fv2) ty (c,n,i) -> match fv2 with [] -> assert false | fv :: fv2 -> (* fv1 @ fv2 = free_variables of other parameters *) if (c||n) && constrained (fv1 @ fv2) ty then raise (Error(loc, Varying_anonymous)); (fv :: fv1, fv2)) ([], fvl) tyl required in compute_variance_type env check rloc {decl with type_params = tyl; type_private = Private} (for_constr tl) | _ -> assert false let compute_variance_extension env check decl ext rloc = compute_variance_gadt env check rloc {decl with type_params = ext.ext_type_params} (ext.ext_args, ext.ext_ret_type) let compute_variance_decl env check decl (required, _ as rloc) = if (decl.type_kind = Type_abstract || decl.type_kind = Type_open) && decl.type_manifest = None then List.map (fun (c, n, i) -> make (not n) (not c) (decl.type_kind <> Type_abstract || i)) required else let mn = match decl.type_manifest with None -> [] | Some ty -> [false, ty] in match decl.type_kind with Type_abstract | Type_open -> compute_variance_type env check rloc decl mn | Type_variant tll -> if List.for_all (fun c -> c.Types.cd_res = None) tll then compute_variance_type env check rloc decl (mn @ List.flatten (List.map (fun c -> for_constr c.Types.cd_args) tll)) else begin let mn = List.map (fun (_,ty) -> (Types.Cstr_tuple [ty],None)) mn in let tll = mn @ List.map (fun c -> c.Types.cd_args, c.Types.cd_res) tll in match List.map (compute_variance_gadt env check rloc decl) tll with | vari :: rem -> let varl = List.fold_left (List.map2 Variance.union) vari rem in List.map Variance.(fun v -> if mem Pos v && mem Neg v then full else v) varl | _ -> assert false end | Type_record (ftl, _) -> compute_variance_type env check rloc decl (mn @ List.map (fun {Types.ld_mutable; ld_type} -> (ld_mutable = Mutable, ld_type)) ftl) let is_sharp id = let s = Ident.name id in String.length s > 0 && s.[0] = '#' let rec compute_variance_fixpoint env decls required variances = let new_decls = List.map2 (fun (id, decl) variance -> id, {decl with type_variance = variance}) decls variances in let new_env = List.fold_right (fun (id, decl) env -> Env.add_type ~check:true id decl env) new_decls env in let new_variances = List.map2 (fun (id, decl) -> compute_variance_decl new_env false decl) new_decls required in let new_variances = List.map2 (List.map2 Variance.union) new_variances variances in if new_variances <> variances then compute_variance_fixpoint env decls required new_variances else begin (* List.iter (fun (id, decl) -> Printf.eprintf "%s:" (Ident.name id); List.iter (fun (v : Variance.t) -> Printf.eprintf " %x" (Obj.magic v : int)) decl.type_variance; prerr_endline "") new_decls; *) List.iter2 (fun (id, decl) req -> if not (is_sharp id) then ignore (compute_variance_decl new_env true decl req)) new_decls required; new_decls, new_env end let init_variance (id, decl) = List.map (fun _ -> Variance.null) decl.type_params let add_injectivity = List.map (function | Covariant -> (true, false, false) | Contravariant -> (false, true, false) | Invariant -> (false, false, false) ) (* for typeclass.ml *) let compute_variance_decls env cldecls = let decls, required = List.fold_right (fun (obj_id, obj_abbr, cl_abbr, clty, cltydef, ci) (decls, req) -> let variance = List.map snd ci.ci_params in (obj_id, obj_abbr) :: decls, (add_injectivity variance, ci.ci_loc) :: req) cldecls ([],[]) in let variances = List.map init_variance decls in let (decls, _) = compute_variance_fixpoint env decls required variances in List.map2 (fun (_,decl) (_, _, cl_abbr, clty, cltydef, _) -> let variance = decl.type_variance in (decl, {cl_abbr with type_variance = variance}, {clty with cty_variance = variance}, {cltydef with clty_variance = variance})) decls cldecls (* Check multiple declarations of labels/constructors *) let check_duplicates sdecl_list = let labels = Hashtbl.create 7 and constrs = Hashtbl.create 7 in List.iter (fun sdecl -> match sdecl.ptype_kind with Ptype_variant cl -> List.iter (fun pcd -> try let name' = Hashtbl.find constrs pcd.pcd_name.txt in Location.prerr_warning pcd.pcd_loc (Warnings.Duplicate_definitions ("constructor", pcd.pcd_name.txt, name', sdecl.ptype_name.txt)) with Not_found -> Hashtbl.add constrs pcd.pcd_name.txt sdecl.ptype_name.txt) cl | Ptype_record fl -> List.iter (fun {pld_name=cname;pld_loc=loc} -> try let name' = Hashtbl.find labels cname.txt in Location.prerr_warning loc (Warnings.Duplicate_definitions ("label", cname.txt, name', sdecl.ptype_name.txt)) with Not_found -> Hashtbl.add labels cname.txt sdecl.ptype_name.txt) fl | Ptype_abstract -> () | Ptype_open -> ()) sdecl_list (* Force recursion to go through id for private types*) let name_recursion sdecl id decl = match decl with | { type_kind = Type_abstract; type_manifest = Some ty; type_private = Private; } when is_fixed_type sdecl -> let ty = Ctype.repr ty in let ty' = Btype.newty2 ty.level ty.desc in if Ctype.deep_occur ty ty' then let td = Tconstr(Path.Pident id, decl.type_params, ref Mnil) in Btype.link_type ty (Btype.newty2 ty.level td); {decl with type_manifest = Some ty'} else decl | _ -> decl (* Translate a set of type declarations, mutually recursive or not *) let transl_type_decl env rec_flag sdecl_list = (* Add dummy types for fixed rows *) let fixed_types = List.filter is_fixed_type sdecl_list in let sdecl_list = List.map (fun sdecl -> let ptype_name = mkloc (sdecl.ptype_name.txt ^"#row") sdecl.ptype_name.loc in {sdecl with ptype_name; ptype_kind = Ptype_abstract; ptype_manifest = None}) fixed_types @ sdecl_list in (* Create identifiers. *) let id_list = List.map (fun sdecl -> Ident.create sdecl.ptype_name.txt) sdecl_list in (* Since we've introduced fresh idents, make sure the definition level is at least the binding time of these events. Otherwise, passing one of the recursively-defined type constrs as argument to an abbreviation may fail. *) Ctype.init_def(Ident.current_time()); Ctype.begin_def(); (* Enter types. *) let temp_env = match rec_flag with | Asttypes.Nonrecursive -> env | Asttypes.Recursive -> List.fold_left2 enter_type env sdecl_list id_list in (* Translate each declaration. *) let current_slot = ref None in let warn_unused = Warnings.is_active (Warnings.Unused_type_declaration "") in let id_slots id = match rec_flag with | Asttypes.Recursive when warn_unused -> (* See typecore.ml for a description of the algorithm used to detect unused declarations in a set of recursive definitions. *) let slot = ref [] in let td = Env.find_type (Path.Pident id) temp_env in let name = Ident.name id in Env.set_type_used_callback name td (fun old_callback -> match !current_slot with | Some slot -> slot := (name, td) :: !slot | None -> List.iter (fun (name, d) -> Env.mark_type_used env name d) (get_ref slot); old_callback () ); id, Some slot | Asttypes.Recursive | Asttypes.Nonrecursive -> id, None in let transl_declaration name_sdecl (id, slot) = current_slot := slot; transl_declaration temp_env name_sdecl id in let tdecls = List.map2 transl_declaration sdecl_list (List.map id_slots id_list) in let decls = List.map (fun tdecl -> (tdecl.typ_id, tdecl.typ_type)) tdecls in current_slot := None; (* Check for duplicates *) check_duplicates sdecl_list; (* Build the final env. *) let newenv = List.fold_right (fun (id, decl) env -> Env.add_type ~check:true id decl env) decls env in (* Update stubs *) begin match rec_flag with | Asttypes.Nonrecursive -> () | Asttypes.Recursive -> List.iter2 (fun id sdecl -> update_type temp_env newenv id sdecl.ptype_loc) id_list sdecl_list end; (* Generalize type declarations. *) Ctype.end_def(); List.iter (fun (_, decl) -> generalize_decl decl) decls; (* Check for ill-formed abbrevs *) let id_loc_list = List.map2 (fun id sdecl -> (id, sdecl.ptype_loc)) id_list sdecl_list in List.iter (fun (id, decl) -> check_well_founded_manifest newenv (List.assoc id id_loc_list) (Path.Pident id) decl) decls; let to_check = function Path.Pident id -> List.mem_assoc id id_loc_list | _ -> false in List.iter (fun (id, decl) -> check_well_founded_decl newenv (List.assoc id id_loc_list) (Path.Pident id) decl to_check) decls; List.iter (check_abbrev_recursion newenv id_loc_list to_check) tdecls; (* Check that all type variable are closed *) List.iter2 (fun sdecl tdecl -> let decl = tdecl.typ_type in match Ctype.closed_type_decl decl with Some ty -> raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl))) | None -> ()) sdecl_list tdecls; (* Check that constraints are enforced *) List.iter2 (check_constraints newenv) sdecl_list decls; (* Name recursion *) let decls = List.map2 (fun sdecl (id, decl) -> id, name_recursion sdecl id decl) sdecl_list decls in (* Add variances to the environment *) let required = List.map (fun sdecl -> add_injectivity (List.map snd sdecl.ptype_params), sdecl.ptype_loc ) sdecl_list in let final_decls, final_env = compute_variance_fixpoint env decls required (List.map init_variance decls) in (* Check re-exportation *) List.iter2 (check_abbrev final_env) sdecl_list final_decls; (* Keep original declaration *) let final_decls = List.map2 (fun tdecl (id2, decl) -> { tdecl with typ_type = decl } ) tdecls final_decls in (* Done *) (final_decls, final_env) (* Translating type extensions *) let transl_extension_constructor env type_path type_params typext_params priv sext = let id = Ident.create sext.pext_name.txt in let args, ret_type, kind = match sext.pext_kind with Pext_decl(sargs, sret_type) -> let targs, tret_type, args, ret_type = make_constructor sext.pext_loc env type_path typext_params sargs sret_type in args, ret_type, Text_decl(targs, tret_type) | Pext_rebind lid -> let cdescr = Typetexp.find_constructor env sext.pext_loc lid.txt in let usage = if cdescr.cstr_private = Private || priv = Public then Env.Positive else Env.Privatize in Env.mark_constructor usage env (Longident.last lid.txt) cdescr; let (args, cstr_res) = Ctype.instance_constructor cdescr in let res, ret_type = if cdescr.cstr_generalized then let params = Ctype.instance_list env type_params in let res = Ctype.newconstr type_path params in let ret_type = Some (Ctype.newconstr type_path params) in res, ret_type else (Ctype.newconstr type_path typext_params), None in begin try Ctype.unify env cstr_res res with Ctype.Unify trace -> raise (Error(lid.loc, Rebind_wrong_type(lid.txt, env, trace))) end; (* Remove "_" names from parameters used in the constructor *) if not cdescr.cstr_generalized then begin let vars = Ctype.free_variables (Btype.newgenty (Ttuple args)) in List.iter (function {desc = Tvar (Some "_")} as ty -> if List.memq ty vars then ty.desc <- Tvar None | _ -> ()) typext_params end; (* Ensure that constructor's type matches the type being extended *) let cstr_type_path, cstr_type_params = match cdescr.cstr_res.desc with Tconstr (p, _, _) -> let decl = Env.find_type p env in p, decl.type_params | _ -> assert false in let cstr_types = (Btype.newgenty (Tconstr(cstr_type_path, cstr_type_params, ref Mnil))) :: cstr_type_params in let ext_types = (Btype.newgenty (Tconstr(type_path, type_params, ref Mnil))) :: type_params in if not (Ctype.equal env true cstr_types ext_types) then raise (Error(lid.loc, Rebind_mismatch(lid.txt, cstr_type_path, type_path))); (* Disallow rebinding private constructors to non-private *) begin match cdescr.cstr_private, priv with Private, Public -> raise (Error(lid.loc, Rebind_private lid.txt)) | _ -> () end; let path = match cdescr.cstr_tag with Cstr_extension(path, _) -> path | _ -> assert false in let args = match cdescr.cstr_inlined with | None -> Types.Cstr_tuple args | Some decl -> let tl = match args with | [ {desc=Tconstr(_, tl, _)} ] -> tl | _ -> assert false in let decl = Ctype.instance_declaration decl in assert (List.length decl.type_params = List.length tl); List.iter2 (Ctype.unify env) decl.type_params tl; let lbls = match decl.type_kind with | Type_record (lbls, Record_extension) -> lbls | _ -> assert false in Types.Cstr_record lbls in args, ret_type, Text_rebind(path, lid) in let ext = { ext_type_path = type_path; ext_type_params = typext_params; ext_args = args; ext_ret_type = ret_type; ext_private = priv; Types.ext_loc = sext.pext_loc; Types.ext_attributes = sext.pext_attributes; } in { ext_id = id; ext_name = sext.pext_name; ext_type = ext; ext_kind = kind; Typedtree.ext_loc = sext.pext_loc; Typedtree.ext_attributes = sext.pext_attributes; } let transl_type_extension check_open env loc styext = reset_type_variables(); Ctype.begin_def(); let (type_path, type_decl) = Typetexp.find_type env loc styext.ptyext_path.txt in begin match type_decl.type_kind with Type_open -> () | Type_abstract -> if check_open then begin try let {pext_loc} = List.find (function {pext_kind = Pext_decl _} -> true | {pext_kind = Pext_rebind _} -> false) styext.ptyext_constructors in raise (Error(pext_loc, Not_open_type type_path)) with Not_found -> () end | _ -> raise (Error(loc, Not_extensible_type type_path)) end; let type_variance = List.map (fun v -> let (co, cn) = Variance.get_upper v in (not cn, not co, false)) type_decl.type_variance in let err = if type_decl.type_arity <> List.length styext.ptyext_params then [Includecore.Arity] else if List.for_all2 (fun (c1, n1, _) (c2, n2, _) -> (not c2 || c1) && (not n2 || n1)) type_variance (add_injectivity (List.map snd styext.ptyext_params)) then [] else [Includecore.Variance] in if err <> [] then raise (Error(loc, Extension_mismatch (type_path, err))); let ttype_params = make_params env styext.ptyext_params in let type_params = List.map (fun (cty, _) -> cty.ctyp_type) ttype_params in List.iter2 (Ctype.unify_var env) (Ctype.instance_list env type_decl.type_params) type_params; let constructors = List.map (transl_extension_constructor env type_path type_decl.type_params type_params styext.ptyext_private) styext.ptyext_constructors in Ctype.end_def(); (* Generalize types *) List.iter Ctype.generalize type_params; List.iter (fun ext -> Btype.iter_type_expr_cstr_args Ctype.generalize ext.ext_type.ext_args; may Ctype.generalize ext.ext_type.ext_ret_type) constructors; (* Check that all type variable are closed *) List.iter (fun ext -> match Ctype.closed_extension_constructor ext.ext_type with Some ty -> raise(Error(ext.ext_loc, Unbound_type_var_ext(ty, ext.ext_type))) | None -> ()) constructors; (* Check variances are correct *) List.iter (fun ext-> ignore (compute_variance_extension env true type_decl ext.ext_type (type_variance, loc))) constructors; (* Add extension constructors to the environment *) let newenv = List.fold_left (fun env ext -> Env.add_extension ~check:true ext.ext_id ext.ext_type env) env constructors in let tyext = { tyext_path = type_path; tyext_txt = styext.ptyext_path; tyext_params = ttype_params; tyext_constructors = constructors; tyext_private = styext.ptyext_private; tyext_attributes = styext.ptyext_attributes; } in (tyext, newenv) let transl_exception env sext = reset_type_variables(); Ctype.begin_def(); let ext = transl_extension_constructor env Predef.path_exn [] [] Asttypes.Public sext in Ctype.end_def(); (* Generalize types *) Btype.iter_type_expr_cstr_args Ctype.generalize ext.ext_type.ext_args; may Ctype.generalize ext.ext_type.ext_ret_type; (* Check that all type variable are closed *) begin match Ctype.closed_extension_constructor ext.ext_type with Some ty -> raise (Error(ext.ext_loc, Unbound_type_var_ext(ty, ext.ext_type))) | None -> () end; let newenv = Env.add_extension ~check:true ext.ext_id ext.ext_type env in ext, newenv type native_repr_attribute = | Native_repr_attr_absent | Native_repr_attr_present of native_repr_kind let get_native_repr_attribute core_type = match List.filter (fun (n, _) -> match n.Location.txt with | "unboxed" | "untagged" -> true | _ -> false) core_type.ptyp_attributes with | [] -> Native_repr_attr_absent | _ :: (n, _) :: _ -> raise (Error (n.Location.loc, Multiple_native_repr_attributes)) | [(n, payload)] -> let kind = if n.txt = "unboxed" then Unboxed else Untagged in match payload with | PStr [] -> Native_repr_attr_present kind | _ -> raise (Error (n.Location.loc, Invalid_native_repr_attribute_payload kind)) let native_repr_of_type env kind ty = match kind, (Ctype.expand_head_opt env ty).desc with | Untagged, Tconstr (path, _, _) when Path.same path Predef.path_int -> Some Untagged_int | Unboxed, Tconstr (path, _, _) when Path.same path Predef.path_float -> Some Unboxed_float | Unboxed, Tconstr (path, _, _) when Path.same path Predef.path_int32 -> Some (Unboxed_integer Pint32) | Unboxed, Tconstr (path, _, _) when Path.same path Predef.path_int64 -> Some (Unboxed_integer Pint64) | Unboxed, Tconstr (path, _, _) when Path.same path Predef.path_nativeint -> Some (Unboxed_integer Pnativeint) | _ -> None let make_native_repr env core_type ty = match get_native_repr_attribute core_type with | Native_repr_attr_absent -> Same_as_ocaml_repr | Native_repr_attr_present kind -> begin match native_repr_of_type env kind ty with | None -> raise (Error (core_type.ptyp_loc, Cannot_unbox_or_untag_type kind)) | Some repr -> repr end let rec parse_native_repr_attributes env core_type ty = match core_type.ptyp_desc, (Ctype.repr ty).desc with | Ptyp_arrow (_, ct1, ct2), Tarrow (_, t1, t2, _) -> let repr_arg = make_native_repr env ct1 t1 in let repr_args, repr_res = parse_native_repr_attributes env ct2 t2 in (repr_arg :: repr_args, repr_res) | Ptyp_arrow _, _ | _, Tarrow _ -> assert false | _ -> ([], make_native_repr env core_type ty) (* Translate a value declaration *) let transl_value_decl env loc valdecl = let cty = Typetexp.transl_type_scheme env valdecl.pval_type in let ty = cty.ctyp_type in let v = match valdecl.pval_prim with [] when Env.is_in_signature env -> { val_type = ty; val_kind = Val_reg; Types.val_loc = loc; val_attributes = valdecl.pval_attributes } | [] -> raise (Error(valdecl.pval_loc, Val_in_structure)) | _ -> let native_repr_args, native_repr_res = parse_native_repr_attributes env valdecl.pval_type ty in let prim = Primitive.parse_declaration valdecl ~native_repr_args ~native_repr_res in if prim.prim_arity = 0 && (prim.prim_name = "" || prim.prim_name.[0] <> '%') then raise(Error(valdecl.pval_type.ptyp_loc, Null_arity_external)); if !Clflags.native_code && prim.prim_arity > 5 && prim.prim_native_name = "" then raise(Error(valdecl.pval_type.ptyp_loc, Missing_native_external)); { val_type = ty; val_kind = Val_prim prim; Types.val_loc = loc; val_attributes = valdecl.pval_attributes } in let (id, newenv) = Env.enter_value valdecl.pval_name.txt v env ~check:(fun s -> Warnings.Unused_value_declaration s) in let desc = { val_id = id; val_name = valdecl.pval_name; val_desc = cty; val_val = v; val_prim = valdecl.pval_prim; val_loc = valdecl.pval_loc; val_attributes = valdecl.pval_attributes; } in desc, newenv (* Translate a "with" constraint -- much simplified version of transl_type_decl. *) let transl_with_constraint env id row_path orig_decl sdecl = Env.mark_type_used env (Ident.name id) orig_decl; reset_type_variables(); Ctype.begin_def(); let tparams = make_params env sdecl.ptype_params in let params = List.map (fun (cty, _) -> cty.ctyp_type) tparams in let orig_decl = Ctype.instance_declaration orig_decl in let arity_ok = List.length params = orig_decl.type_arity in if arity_ok then List.iter2 (Ctype.unify_var env) params orig_decl.type_params; let constraints = List.map (function (ty, ty', loc) -> try let cty = transl_simple_type env false ty in let cty' = transl_simple_type env false ty' in let ty = cty.ctyp_type in let ty' = cty'.ctyp_type in Ctype.unify env ty ty'; (cty, cty', loc) with Ctype.Unify tr -> raise(Error(loc, Inconsistent_constraint (env, tr)))) sdecl.ptype_cstrs in let no_row = not (is_fixed_type sdecl) in let (tman, man) = match sdecl.ptype_manifest with None -> None, None | Some sty -> let cty = transl_simple_type env no_row sty in Some cty, Some cty.ctyp_type in let priv = if sdecl.ptype_private = Private then Private else if arity_ok && orig_decl.type_kind <> Type_abstract then orig_decl.type_private else sdecl.ptype_private in if arity_ok && orig_decl.type_kind <> Type_abstract && sdecl.ptype_private = Private then Location.prerr_warning sdecl.ptype_loc (Warnings.Deprecated "spurious use of private"); let decl = { type_params = params; type_arity = List.length params; type_kind = if arity_ok && man <> None then orig_decl.type_kind else Type_abstract; type_private = priv; type_manifest = man; type_variance = []; type_newtype_level = None; type_loc = sdecl.ptype_loc; type_attributes = sdecl.ptype_attributes; } in begin match row_path with None -> () | Some p -> set_fixed_row env sdecl.ptype_loc p decl end; begin match Ctype.closed_type_decl decl with None -> () | Some ty -> raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl))) end; let decl = name_recursion sdecl id decl in let decl = {decl with type_variance = compute_variance_decl env true decl (add_injectivity (List.map snd sdecl.ptype_params), sdecl.ptype_loc)} in Ctype.end_def(); generalize_decl decl; { typ_id = id; typ_name = sdecl.ptype_name; typ_params = tparams; typ_type = decl; typ_cstrs = constraints; typ_loc = sdecl.ptype_loc; typ_manifest = tman; typ_kind = Ttype_abstract; typ_private = sdecl.ptype_private; typ_attributes = sdecl.ptype_attributes; } (* Approximate a type declaration: just make all types abstract *) let abstract_type_decl arity = let rec make_params n = if n <= 0 then [] else Ctype.newvar() :: make_params (n-1) in Ctype.begin_def(); let decl = { type_params = make_params arity; type_arity = arity; type_kind = Type_abstract; type_private = Public; type_manifest = None; type_variance = replicate_list Variance.full arity; type_newtype_level = None; type_loc = Location.none; type_attributes = []; } in Ctype.end_def(); generalize_decl decl; decl let approx_type_decl env sdecl_list = List.map (fun sdecl -> (Ident.create sdecl.ptype_name.txt, abstract_type_decl (List.length sdecl.ptype_params))) sdecl_list (* Variant of check_abbrev_recursion to check the well-formedness conditions on type abbreviations defined within recursive modules. *) let check_recmod_typedecl env loc recmod_ids path decl = (* recmod_ids is the list of recursively-defined module idents. (path, decl) is the type declaration to be checked. *) let to_check path = List.exists (fun id -> Path.isfree id path) recmod_ids in check_well_founded_decl env loc path decl to_check; check_recursion env loc path decl to_check (**** Error report ****) open Format let explain_unbound_gen ppf tv tl typ kwd pr = try let ti = List.find (fun ti -> Ctype.deep_occur tv (typ ti)) tl in let ty0 = (* Hack to force aliasing when needed *) Btype.newgenty (Tobject(tv, ref None)) in Printtyp.reset_and_mark_loops_list [typ ti; ty0]; fprintf ppf ".@.@[In %s@ %a@;<1 -2>the variable %a is unbound@]" kwd pr ti Printtyp.type_expr tv with Not_found -> () let explain_unbound ppf tv tl typ kwd lab = explain_unbound_gen ppf tv tl typ kwd (fun ppf ti -> fprintf ppf "%s%a" (lab ti) Printtyp.type_expr (typ ti)) let explain_unbound_single ppf tv ty = let trivial ty = explain_unbound ppf tv [ty] (fun t -> t) "type" (fun _ -> "") in match (Ctype.repr ty).desc with Tobject(fi,_) -> let (tl, rv) = Ctype.flatten_fields fi in if rv == tv then trivial ty else explain_unbound ppf tv tl (fun (_,_,t) -> t) "method" (fun (lab,_,_) -> lab ^ ": ") | Tvariant row -> let row = Btype.row_repr row in if row.row_more == tv then trivial ty else explain_unbound ppf tv row.row_fields (fun (l,f) -> match Btype.row_field_repr f with Rpresent (Some t) -> t | Reither (_,[t],_,_) -> t | Reither (_,tl,_,_) -> Btype.newgenty (Ttuple tl) | _ -> Btype.newgenty (Ttuple[])) "case" (fun (lab,_) -> "`" ^ lab ^ " of ") | _ -> trivial ty let tys_of_constr_args = function | Types.Cstr_tuple tl -> tl | Types.Cstr_record lbls -> List.map (fun l -> l.Types.ld_type) lbls let report_error ppf = function | Repeated_parameter -> fprintf ppf "A type parameter occurs several times" | Duplicate_constructor s -> fprintf ppf "Two constructors are named %s" s | Too_many_constructors -> fprintf ppf "@[Too many non-constant constructors@ -- maximum is %i %s@]" (Config.max_tag + 1) "non-constant constructors" | Duplicate_label s -> fprintf ppf "Two labels are named %s" s | Recursive_abbrev s -> fprintf ppf "The type abbreviation %s is cyclic" s | Cycle_in_def (s, ty) -> Printtyp.reset_and_mark_loops ty; fprintf ppf "@[The definition of %s contains a cycle:@ %a@]" s Printtyp.type_expr ty | Definition_mismatch (ty, errs) -> Printtyp.reset_and_mark_loops ty; fprintf ppf "@[@[%s@ %s@;<1 2>%a@]%a@]" "This variant or record definition" "does not match that of type" Printtyp.type_expr ty (Includecore.report_type_mismatch "the original" "this" "definition") errs | Constraint_failed (ty, ty') -> Printtyp.reset_and_mark_loops ty; Printtyp.mark_loops ty'; fprintf ppf "@[%s@ @[Type@ %a@ should be an instance of@ %a@]@]" "Constraints are not satisfied in this type." Printtyp.type_expr ty Printtyp.type_expr ty' | Parameters_differ (path, ty, ty') -> Printtyp.reset_and_mark_loops ty; Printtyp.mark_loops ty'; fprintf ppf "@[In the definition of %s, type@ %a@ should be@ %a@]" (Path.name path) Printtyp.type_expr ty Printtyp.type_expr ty' | Inconsistent_constraint (env, trace) -> fprintf ppf "The type constraints are not consistent.@."; Printtyp.report_unification_error ppf env trace (fun ppf -> fprintf ppf "Type") (fun ppf -> fprintf ppf "is not compatible with type") | Type_clash (env, trace) -> Printtyp.report_unification_error ppf env trace (function ppf -> fprintf ppf "This type constructor expands to type") (function ppf -> fprintf ppf "but is used here with type") | Null_arity_external -> fprintf ppf "External identifiers must be functions" | Missing_native_external -> fprintf ppf "@[An external function with more than 5 arguments \ requires a second stub function@ \ for native-code compilation@]" | Unbound_type_var (ty, decl) -> fprintf ppf "A type variable is unbound in this type declaration"; let ty = Ctype.repr ty in begin match decl.type_kind, decl.type_manifest with | Type_variant tl, _ -> explain_unbound_gen ppf ty tl (fun c -> let tl = tys_of_constr_args c.cd_args in Btype.newgenty (Ttuple tl) ) "case" (fun ppf c -> fprintf ppf "%s of %a" (Ident.name c.Types.cd_id) Printtyp.constructor_arguments c.cd_args) | Type_record (tl, _), _ -> explain_unbound ppf ty tl (fun l -> l.Types.ld_type) "field" (fun l -> Ident.name l.Types.ld_id ^ ": ") | Type_abstract, Some ty' -> explain_unbound_single ppf ty ty' | _ -> () end | Unbound_type_var_ext (ty, ext) -> fprintf ppf "A type variable is unbound in this extension constructor"; let args = tys_of_constr_args ext.ext_args in explain_unbound ppf ty args (fun c -> c) "type" (fun _ -> "") | Not_open_type path -> fprintf ppf "@[%s@ %a@]" "Cannot extend type definition" Printtyp.path path | Not_extensible_type path -> fprintf ppf "@[%s@ %a@ %s@]" "Type" Printtyp.path path "is not extensible" | Extension_mismatch (path, errs) -> fprintf ppf "@[@[%s@ %s@;<1 2>%s@]%a@]" "This extension" "does not match the definition of type" (Path.name path) (Includecore.report_type_mismatch "the type" "this extension" "definition") errs | Rebind_wrong_type (lid, env, trace) -> Printtyp.report_unification_error ppf env trace (function ppf -> fprintf ppf "The constructor %a@ has type" Printtyp.longident lid) (function ppf -> fprintf ppf "but was expected to be of type") | Rebind_mismatch (lid, p, p') -> fprintf ppf "@[%s@ %a@ %s@ %s@ %s@ %s@ %s@]" "The constructor" Printtyp.longident lid "extends type" (Path.name p) "whose declaration does not match" "the declaration of type" (Path.name p') | Rebind_private lid -> fprintf ppf "@[%s@ %a@ %s@]" "The constructor" Printtyp.longident lid "is private" | Bad_variance (n, v1, v2) -> let variance (p,n,i) = let inj = if i then "injective " else "" in match p, n with true, true -> inj ^ "invariant" | true, false -> inj ^ "covariant" | false, true -> inj ^ "contravariant" | false, false -> if inj = "" then "unrestricted" else inj in let suffix n = let teen = (n mod 100)/10 = 1 in match n mod 10 with | 1 when not teen -> "st" | 2 when not teen -> "nd" | 3 when not teen -> "rd" | _ -> "th" in if n = -1 then fprintf ppf "@[%s@ %s@ It" "In this definition, a type variable has a variance that" "is not reflected by its occurrence in type parameters." else if n = -2 then fprintf ppf "@[%s@ %s@]" "In this definition, a type variable cannot be deduced" "from the type parameters." else if n = -3 then fprintf ppf "@[%s@ %s@ It" "In this definition, a type variable has a variance that" "cannot be deduced from the type parameters." else fprintf ppf "@[%s@ %s@ The %d%s type parameter" "In this definition, expected parameter" "variances are not satisfied." n (suffix n); if n <> -2 then fprintf ppf " was expected to be %s,@ but it is %s.@]" (variance v2) (variance v1) | Unavailable_type_constructor p -> fprintf ppf "The definition of type %a@ is unavailable" Printtyp.path p | Bad_fixed_type r -> fprintf ppf "This fixed type %s" r | Varying_anonymous -> fprintf ppf "@[%s@ %s@ %s@]" "In this GADT definition," "the variance of some parameter" "cannot be checked" | Val_in_structure -> fprintf ppf "Value declarations are only allowed in signatures" | Invalid_native_repr_attribute_payload kind -> fprintf ppf "[@%s] attribute does not accept a payload" (string_of_native_repr_kind kind) | Multiple_native_repr_attributes -> fprintf ppf "Too many [@unboxed]/[@untagged] attributes" | Cannot_unbox_or_untag_type Unboxed -> fprintf ppf "Don't know how to unbox this type. Only float, int32, \ int64 and nativeint can be unboxed" | Cannot_unbox_or_untag_type Untagged -> fprintf ppf "Don't know how to untag this type. Only int \ can be untagged" let () = Location.register_error_of_exn (function | Error (loc, err) -> Some (Location.error_of_printer loc report_error err) | _ -> None )