ocaml/otherlibs/dynlink/dynlink.ml

333 lines
11 KiB
OCaml

(***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* 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. *)
(* *)
(***********************************************************************)
(* Dynamic loading of .cmo files *)
open Dynlinkaux (* REMOVE_ME for ../../debugger/dynlink.ml *)
open Cmo_format
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
| Inconsistent_implementation of string
exception Error of error
let () =
Printexc.register_printer
(function
| Error err ->
let msg = match err with
| Not_a_bytecode_file s ->
Printf.sprintf "Not_a_bytecode_file %S" s
| Inconsistent_import s ->
Printf.sprintf "Inconsistent_import %S" s
| Unavailable_unit s ->
Printf.sprintf "Unavailable_unit %S" s
| Unsafe_file ->
"Unsafe_file"
| Linking_error (s, Undefined_global s') ->
Printf.sprintf "Linking_error (%S, Dynlink.Undefined_global %S)"
s s'
| Linking_error (s, Unavailable_primitive s') ->
Printf.sprintf "Linking_error (%S, Dynlink.Unavailable_primitive \
%S)" s s'
| Linking_error (s, Uninitialized_global s') ->
Printf.sprintf "Linking_error (%S, Dynlink.Uninitialized_global \
%S)" s s'
| Corrupted_interface s ->
Printf.sprintf "Corrupted_interface %S" s
| File_not_found s ->
Printf.sprintf "File_not_found %S" s
| Cannot_open_dll s ->
Printf.sprintf "Cannot_open_dll %S" s
| Inconsistent_implementation s ->
Printf.sprintf "Inconsistent_implementation %S" s in
Some (Printf.sprintf "Dynlink.Error(Dynlink.%s)" msg)
| _ -> None)
(* Management of interface CRCs *)
let crc_interfaces = ref (Consistbl.create ())
let allow_extension = ref true
(* Check that the object file being loaded has been compiled against
the same interfaces as the program itself. In addition, check that
only authorized compilation units are referenced. *)
let check_consistency file_name cu =
try
List.iter
(fun (name, crco) ->
match crco with
None -> ()
| Some crc ->
if name = cu.cu_name then
Consistbl.set !crc_interfaces name crc file_name
else if !allow_extension then
Consistbl.check !crc_interfaces name crc file_name
else
Consistbl.check_noadd !crc_interfaces name crc file_name)
cu.cu_imports
with Consistbl.Inconsistency(name, user, auth) ->
raise(Error(Inconsistent_import name))
| Consistbl.Not_available(name) ->
raise(Error(Unavailable_unit name))
(* Empty the crc_interfaces table *)
let clear_available_units () =
Consistbl.clear !crc_interfaces;
allow_extension := false
(* Allow only access to the units with the given names *)
let allow_only names =
Consistbl.filter (fun name -> List.mem name names) !crc_interfaces;
allow_extension := false
(* Prohibit access to the units with the given names *)
let prohibit names =
Consistbl.filter (fun name -> not (List.mem name names)) !crc_interfaces;
allow_extension := false
(* Initialize the crc_interfaces table with a list of units with fixed CRCs *)
let add_available_units units =
List.iter
(fun (unit, crc) -> Consistbl.set !crc_interfaces unit crc "")
units
(* Default interface CRCs: those found in the current executable *)
let default_crcs = ref []
let default_available_units () =
clear_available_units();
List.iter
(fun (unit, crco) ->
match crco with
None -> ()
| Some crc -> Consistbl.set !crc_interfaces unit crc "")
!default_crcs;
allow_extension := true
(* Initialize the linker tables and everything *)
let inited = ref false
let init () =
if not !inited then begin
default_crcs := Symtable.init_toplevel();
default_available_units ();
inited := true;
end
let clear_available_units () = init(); clear_available_units ()
let allow_only l = init(); allow_only l
let prohibit l = init(); prohibit l
let add_available_units l = init(); add_available_units l
let default_available_units () = init(); default_available_units ()
(* Read the CRC of an interface from its .cmi file *)
let digest_interface unit loadpath =
let filename =
let shortname = unit ^ ".cmi" in
try
Misc.find_in_path_uncap loadpath shortname
with Not_found ->
raise (Error(File_not_found shortname)) in
let ic = open_in_bin filename in
try
let buffer =
really_input_string ic (String.length Config.cmi_magic_number)
in
if buffer <> Config.cmi_magic_number then begin
close_in ic;
raise(Error(Corrupted_interface filename))
end;
let cmi = Cmi_format.input_cmi ic in
close_in ic;
let crc =
match cmi.Cmi_format.cmi_crcs with
(_, Some crc) :: _ -> crc
| _ -> raise(Error(Corrupted_interface filename))
in
crc
with End_of_file | Failure _ ->
close_in ic;
raise(Error(Corrupted_interface filename))
(* Initialize the crc_interfaces table with a list of units.
Their CRCs are read from their interfaces. *)
let add_interfaces units loadpath =
add_available_units
(List.map (fun unit -> (unit, digest_interface unit loadpath)) units)
(* Check whether the object file being loaded was compiled in unsafe mode *)
let unsafe_allowed = ref false
let allow_unsafe_modules b =
unsafe_allowed := b
let check_unsafe_module cu =
if (not !unsafe_allowed) && cu.cu_primitives <> []
then raise(Error(Unsafe_file))
(* Load in-core and execute a bytecode object file *)
external register_code_fragment: bytes -> int -> string -> unit
= "caml_register_code_fragment"
let load_compunit ic file_name file_digest compunit =
check_consistency file_name compunit;
check_unsafe_module compunit;
seek_in ic compunit.cu_pos;
let code_size = compunit.cu_codesize + 8 in
let code = Meta.static_alloc code_size in
unsafe_really_input ic code 0 compunit.cu_codesize;
Bytes.unsafe_set code compunit.cu_codesize (Char.chr Opcodes.opRETURN);
Bytes.unsafe_set code (compunit.cu_codesize + 1) '\000';
Bytes.unsafe_set code (compunit.cu_codesize + 2) '\000';
Bytes.unsafe_set code (compunit.cu_codesize + 3) '\000';
Bytes.unsafe_set code (compunit.cu_codesize + 4) '\001';
Bytes.unsafe_set code (compunit.cu_codesize + 5) '\000';
Bytes.unsafe_set code (compunit.cu_codesize + 6) '\000';
Bytes.unsafe_set code (compunit.cu_codesize + 7) '\000';
let initial_symtable = Symtable.current_state() in
begin try
Symtable.patch_object code compunit.cu_reloc;
Symtable.check_global_initialized compunit.cu_reloc;
Symtable.update_global_table()
with Symtable.Error error ->
let new_error =
match error with
Symtable.Undefined_global s -> Undefined_global s
| Symtable.Unavailable_primitive s -> Unavailable_primitive s
| Symtable.Uninitialized_global s -> Uninitialized_global s
| _ -> assert false in
raise(Error(Linking_error (file_name, new_error)))
end;
(* PR#5215: identify this code fragment by
digest of file contents + unit name.
Unit name is needed for .cma files, which produce several code fragments.*)
let digest = Digest.string (file_digest ^ compunit.cu_name) in
register_code_fragment code code_size digest;
let events =
if compunit.cu_debug = 0 then [| |]
else begin
seek_in ic compunit.cu_debug;
[| input_value ic |]
end in
Meta.add_debug_info code code_size events;
begin try
ignore((Meta.reify_bytecode code code_size) ())
with exn ->
Symtable.restore_state initial_symtable;
raise exn
end
let loadfile file_name =
init();
if not (Sys.file_exists file_name)
then raise (Error (File_not_found file_name));
let ic = open_in_bin file_name in
let file_digest = Digest.channel ic (-1) in
seek_in ic 0;
try
let buffer =
try really_input_string ic (String.length Config.cmo_magic_number)
with End_of_file -> raise (Error (Not_a_bytecode_file file_name))
in
if buffer = Config.cmo_magic_number then begin
let compunit_pos = input_binary_int ic in (* Go to descriptor *)
seek_in ic compunit_pos;
let cu = (input_value ic : compilation_unit) in
load_compunit ic file_name file_digest cu
end else
if buffer = Config.cma_magic_number then begin
let toc_pos = input_binary_int ic in (* Go to table of contents *)
seek_in ic toc_pos;
let lib = (input_value ic : library) in
begin try
Dll.open_dlls Dll.For_execution
(List.map Dll.extract_dll_name lib.lib_dllibs)
with Failure reason ->
raise(Error(Cannot_open_dll reason))
end;
List.iter (load_compunit ic file_name file_digest) lib.lib_units
end else
raise(Error(Not_a_bytecode_file file_name));
close_in ic
with exc ->
close_in ic; raise exc
let loadfile_private file_name =
init();
let initial_symtable = Symtable.current_state()
and initial_crc = !crc_interfaces in
try
loadfile file_name;
Symtable.hide_additions initial_symtable;
crc_interfaces := initial_crc
with exn ->
Symtable.hide_additions initial_symtable;
crc_interfaces := initial_crc;
raise exn
(* Error report *)
let error_message = function
Not_a_bytecode_file name ->
name ^ " is not a bytecode object file"
| Inconsistent_import name ->
"interface mismatch on " ^ name
| Unavailable_unit name ->
"no implementation available for " ^ name
| Unsafe_file ->
"this object file uses unsafe features"
| Linking_error (name, Undefined_global s) ->
"error while linking " ^ name ^ ".\n" ^
"Reference to undefined global `" ^ s ^ "'"
| Linking_error (name, Unavailable_primitive s) ->
"error while linking " ^ name ^ ".\n" ^
"The external function `" ^ s ^ "' is not available"
| Linking_error (name, Uninitialized_global s) ->
"error while linking " ^ name ^ ".\n" ^
"The module `" ^ s ^ "' is not yet initialized"
| Corrupted_interface name ->
"corrupted interface file " ^ name
| File_not_found name ->
"cannot find file " ^ name ^ " in search path"
| Cannot_open_dll reason ->
"error loading shared library: " ^ reason
| Inconsistent_implementation name ->
"implementation mismatch on " ^ name
let is_native = false
let adapt_filename f = f