/usr/lib/ocaml/atd/atd_check.ml is in libatd-ocaml-dev 1.1.2-1build4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | (* Semantic verification *)
open Printf
open Atd_ast
let add_name accu = function
`Name (_, (loc, k, tal), _) -> k :: accu
| _ -> accu
let get_kind = function
`Sum _ -> `Sum
| `Record _ -> `Record
| _ -> `Other
let check_inheritance tbl (t0 : type_expr) =
let not_a kind x =
let msg =
sprintf "Cannot inherit from non-%s type"
(match kind with
`Sum -> "variant"
| `Record -> "record"
| _ -> assert false)
in
error_at (loc_of_type_expr t0) msg
in
let rec check kind inherited (t : type_expr) =
match t with
`Sum (_, vl, _) when kind = `Sum ->
List.iter (
function
`Inherit (_, t) -> check kind inherited t
| `Variant _ -> ()
) vl
| `Record (_, fl, _) when kind = `Record ->
List.iter (
function
`Inherit (_, t) -> check kind inherited t
| `Field _ -> ()
) fl
| `Sum _
| `Record _
| `Tuple _
| `List _
| `Option _
| `Nullable _
| `Shared _
| `Wrap _ as x -> not_a kind x
| `Name (_, (loc, k, tal), _) ->
if List.mem k inherited then
error_at (loc_of_type_expr t0) "Cyclic inheritance"
else
let (arity, opt_def) =
try Hashtbl.find tbl k
with Not_found -> error_at loc ("Undefined type " ^ k)
in
(match opt_def with
None -> ()
| Some (_, _, t) -> check kind (k :: inherited) t
)
| `Tvar _ ->
error_at (loc_of_type_expr t0) "Cannot inherit from a type variable"
in
check (get_kind t0) (add_name [] t0) t0
let check_type_expr tbl tvars (t : type_expr) =
let rec check : type_expr -> unit = function
`Sum (_, vl, _) as x ->
List.iter (check_variant (Hashtbl.create 10)) vl;
check_inheritance tbl x
| `Record (_, fl, _) as x ->
List.iter (check_field (Hashtbl.create 10)) fl;
check_inheritance tbl x
| `Tuple (_, tl, _) -> List.iter (fun (_, x, _) -> check x) tl
| `List (_, t, _) -> check t
| `Option (_, t, _) -> check t
| `Nullable (_, t, _) -> check t
| `Shared (loc, t, _) ->
if Atd_ast.is_parametrized t then
error_at loc "Shared type cannot be polymorphic";
check t
| `Wrap (_, t, _) -> check t
| `Name (_, (loc, k, tal), _) ->
assert (k <> "list" && k <> "option"
&& k <> "nullable" && k <> "shared" && k <> "wrap");
let (arity, opt_def) =
try Hashtbl.find tbl k
with Not_found -> error_at loc ("Undefined type " ^ k)
in
let n = List.length tal in
if arity <> n then
error_at loc (sprintf "Type %s was defined to take %i parameters, \
but %i argument%s."
k arity n (if n > 1 then "s are given"
else " is given")
);
List.iter check tal
| `Tvar (loc, s) ->
if not (List.mem s tvars) then
error_at loc (sprintf "Unbound type variable '%s" s)
and check_variant accu = function
`Variant (loc, (k, _), opt_t) ->
if Hashtbl.mem accu k then
error_at loc
(sprintf
"Multiple definitions of the same variant constructor %s" k);
Hashtbl.add accu k ();
(match opt_t with
None -> ()
| Some t -> check t)
| `Inherit (_, t) ->
(* overriding is allowed, for now without a warning *)
check t
and check_field accu = function
`Field (loc, (k, fk, _), t) ->
if Hashtbl.mem accu k then
error_at loc
(sprintf "Multiple definitions of the same field %s" k);
Hashtbl.add accu k ();
check t
| `Inherit (_, t) ->
(* overriding is allowed, for now without a warning *)
check t
in
check t
let check (l : Atd_ast.module_body) =
let predef = Atd_predef.make_table () in
let tbl = Hashtbl.copy predef in
(* first pass: put all definitions in the table *)
List.iter (
function `Type ((loc, (k, pl, a), t) as x) ->
if Hashtbl.mem tbl k then
if Hashtbl.mem predef k then
error_at loc
(sprintf "%s is a predefined type, it cannot be redefined." k)
else
error_at loc
(sprintf "Type %s is defined for the second time." k)
else
Hashtbl.add tbl k (List.length pl, Some x)
) l;
(* second pass: check existence and arity of types in type expressions,
check that inheritance is not cyclic *)
List.iter (
function `Type (loc, (k, tvars, a), t) ->
check_type_expr tbl tvars t
) l;
|