Module Dynlink

module Dynlink: sig .. end

val is_native : bool

true if the program is native, false if the program is bytecode.

val loadfile : string -> unit

In bytecode: load the given bytecode object file (.cmo file) or bytecode library file (.cma file), and link it with the running program. In native code: load the given OCaml plugin file (usually .cmxs), 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.

val adapt_filename : string -> string

In bytecode, the identity function. In native code, replace the last extension with .cmxs.

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. In native code, this function does nothing; object files with external functions are always allowed to be dynamically linked.

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.

val init : unit -> unit

Deprecated.Initialize the Dynlink library. This function is called automatically when needed.

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.