Module Dynlink

module Dynlink: sig  end

Dynamic loading of bytecode object files.

val init : unit -> unit

Initialize the library. Must be called before loadfile.

val loadfile : string -> unit

Load the given bytecode object file and link it. All toplevel expressions in the loaded compilation unit 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 module loaded is not made available to other modules dynamically loaded afterwards.

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). Initially, dynamically-linked object files do not have access to any of the compilation units composing the running program, not even the standard library. add_interfaces or Dynlink.add_available_units (see below) must be called to grant access to some of the units.

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

Clear the list of compilation units accessible to dynamically-linked programs.

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.

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.