ocaml/otherlibs/dynlink/dynlink.mli

130 lines
5.4 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, 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 GNU Library General Public License, with *)
(* the special exception on linking described in file ../../LICENSE. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(** Dynamic loading of bytecode object files. *)
(** {6 Initialization} *)
val init : unit -> unit
(** Initialize the [Dynlink] library.
Must be called before any other function in this module. *)
(** {6 Dynamic loading of compiled bytecode files} *)
val loadfile : string -> unit
(** Load the given bytecode object file ([.cmo] file) or
bytecode library file ([.cma] file), and link it with the running program.
All toplevel expressions in the loaded compilation units
are evaluated. No facilities are provided to
access value names defined by the unit. Therefore, the unit
must register itself its entry points with the main program,
e.g. by modifying tables of functions. *)
val loadfile_private : string -> unit
(** Same as [loadfile], except that the compilation units just loaded
are hidden (cannot be referenced) from other modules dynamically
loaded afterwards. *)
(** {6 Access control} *)
val allow_only: string list -> unit
(** [allow_only units] restricts the compilation units that dynamically-linked
units can reference: it only allows references to the units named in
list [units]. References to any other compilation unit will cause
a [Unavailable_unit] error during [loadfile] or [loadfile_private].
Initially (just after calling [init]), all compilation units composing
the program currently running are available for reference from
dynamically-linked units. [allow_only] can be used to grant access
to some of them only, e.g. to the units that compose the API for
dynamically-linked code, and prevent access to all other units,
e.g. private, internal modules of the running program. *)
val prohibit: string list -> unit
(** [prohibit units] prohibits dynamically-linked units from referencing
the units named in list [units]. This can be used to prevent
access to selected units, e.g. private, internal modules of
the running program. *)
val default_available_units: unit -> unit
(** Reset the set of units that can be referenced from dynamically-linked
code to its default value, that is, all units composing the currently
running program. *)
val allow_unsafe_modules : bool -> unit
(** Govern whether unsafe object files are allowed to be
dynamically linked. A compilation unit is ``unsafe'' if it contains
declarations of external functions, which can break type safety.
By default, dynamic linking of unsafe object files is
not allowed. *)
(** {6 Deprecated, low-level API for access control} *)
(** @deprecated The functions [add_interfaces], [add_available_units]
and [clear_available_units] should not be used in new programs,
since the default initialization of allowed units, along with the
[allow_only] and [prohibit] function, provides a better, safer
mechanism to control access to program units. The three functions
below are provided for backward compatibility only. *)
val add_interfaces : string list -> string list -> unit
(** [add_interfaces units path] grants dynamically-linked object
files access to the compilation units named in list [units].
The interfaces ([.cmi] files) for these units are searched in
[path] (a list of directory names). *)
val add_available_units : (string * Digest.t) list -> unit
(** Same as {!Dynlink.add_interfaces}, but instead of searching [.cmi] files
to find the unit interfaces, uses the interface digests given
for each unit. This way, the [.cmi] interface files need not be
available at run-time. The digests can be extracted from [.cmi]
files using the [extract_crc] program installed in the
Objective Caml standard library directory. *)
val clear_available_units : unit -> unit
(** Empty the list of compilation units accessible to dynamically-linked
programs. *)
(** {6 Error reporting} *)
type linking_error =
Undefined_global of string
| Unavailable_primitive of string
| Uninitialized_global of string
type error =
Not_a_bytecode_file of string
| Inconsistent_import of string
| Unavailable_unit of string
| Unsafe_file
| Linking_error of string * linking_error
| Corrupted_interface of string
| File_not_found of string
| Cannot_open_dll of string
exception Error of error
(** Errors in dynamic linking are reported by raising the [Error]
exception with a description of the error. *)
val error_message : error -> string
(** Convert an error description to a printable message. *)
(**/**)
(** {6 Internal functions} *)
val digest_interface : string -> string list -> Digest.t