aboutsummaryrefslogtreecommitdiffhomepage
path: root/library/library.ml
blob: 024ac9e6fa5da2a2ed40cc048ceaf3bd06e2eafb (plain)
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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2015     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

open Pp
open Errors
open Util

open Names
open Libnames
open Nameops
open Libobject
open Lib

(************************************************************************)
(*s Low-level interning/externing of libraries to files *)

let raw_extern_library f =
  System.raw_extern_state Coq_config.vo_magic_number f

let raw_intern_library f =
  System.with_magic_number_check
    (System.raw_intern_state Coq_config.vo_magic_number) f

(************************************************************************)
(** Serialized objects loaded on-the-fly *)

exception Faulty of string

module Delayed :
sig

type 'a delayed
val in_delayed : string -> in_channel -> 'a delayed
val fetch_delayed : 'a delayed -> 'a

end =
struct

type 'a delayed = {
  del_file : string;
  del_off : int;
  del_digest : Digest.t;
}

let in_delayed f ch =
  let pos = pos_in ch in
  let _, digest = System.skip_in_segment f ch in
  { del_file = f; del_digest = digest; del_off = pos; }

(** Fetching a table of opaque terms at position [pos] in file [f],
    expecting to find first a copy of [digest]. *)

let fetch_delayed del =
  let { del_digest = digest; del_file = f; del_off = pos; } = del in
  try
    let ch = raw_intern_library f in
    let () = seek_in ch pos in
    let obj, _, digest' = System.marshal_in_segment f ch in
    let () = close_in ch in
    if not (String.equal digest digest') then raise (Faulty f);
    obj
  with e when Errors.noncritical e -> raise (Faulty f)

end

open Delayed


(************************************************************************)
(*s Modules on disk contain the following informations (after the magic
    number, and before the digest). *)

type compilation_unit_name = DirPath.t

type library_disk = {
  md_compiled : Safe_typing.compiled_library;
  md_objects : Declaremods.library_objects;
}

type summary_disk = {
  md_name : compilation_unit_name;
  md_imports : compilation_unit_name array;
  md_deps : (compilation_unit_name * Safe_typing.vodigest) array;
}

(*s Modules loaded in memory contain the following informations. They are
    kept in the global table [libraries_table]. *)

type library_t = {
  library_name : compilation_unit_name;
  library_data : library_disk delayed;
  library_deps : (compilation_unit_name * Safe_typing.vodigest) array;
  library_imports : compilation_unit_name array;
  library_digests : Safe_typing.vodigest;
  library_extra_univs : Univ.universe_context_set;
}

type library_summary = {
  libsum_name : compilation_unit_name;
  libsum_digests : Safe_typing.vodigest;
  libsum_imports : compilation_unit_name array;
}

module LibraryOrdered = DirPath
module LibraryMap = Map.Make(LibraryOrdered)
module LibraryFilenameMap = Map.Make(LibraryOrdered)

(* This is a map from names to loaded libraries *)
let libraries_table : library_summary LibraryMap.t ref =
  Summary.ref LibraryMap.empty ~name:"LIBRARY"

(* This is the map of loaded libraries filename *)
(* (not synchronized so as not to be caught in the states on disk) *)
let libraries_filename_table = ref LibraryFilenameMap.empty

(* These are the _ordered_ sets of loaded, imported and exported libraries *)
let libraries_loaded_list = Summary.ref [] ~name:"LIBRARY-LOAD"
let libraries_imports_list = Summary.ref [] ~name:"LIBRARY-IMPORT"
let libraries_exports_list = Summary.ref [] ~name:"LIBRARY-EXPORT"

(* various requests to the tables *)

let find_library dir =
  LibraryMap.find dir !libraries_table

let try_find_library dir =
  try find_library dir
  with Not_found ->
    errorlabstrm "Library.find_library"
      (str "Unknown library " ++ str (DirPath.to_string dir))

let register_library_filename dir f =
  (* Not synchronized: overwrite the previous binding if one existed *)
  (* from a previous play of the session *)
  libraries_filename_table :=
    LibraryFilenameMap.add dir f !libraries_filename_table

let library_full_filename dir =
  try LibraryFilenameMap.find dir !libraries_filename_table
  with Not_found -> "<unavailable filename>"

let overwrite_library_filenames f =
  let f =
    if Filename.is_relative f then Filename.concat (Sys.getcwd ()) f else f in
  LibraryMap.iter (fun dir _ -> register_library_filename dir f)
    !libraries_table

let library_is_loaded dir =
  try let _ = find_library dir in true
  with Not_found -> false

let library_is_opened dir =
  List.exists (fun name -> DirPath.equal name dir) !libraries_imports_list

let loaded_libraries () = !libraries_loaded_list

let opened_libraries () = !libraries_imports_list

  (* If a library is loaded several time, then the first occurrence must
     be performed first, thus the libraries_loaded_list ... *)

let register_loaded_library m =
  let libname = m.libsum_name in
  let link m =
    let dirname = Filename.dirname (library_full_filename libname) in
    let prefix = Nativecode.mod_uid_of_dirpath libname ^ "." in
    let f = prefix ^ "cmo" in
    let f = Dynlink.adapt_filename f in
    (* This will not produce errors or warnings if the native compiler was
       not enabled *)
    Nativelib.link_library ~prefix ~dirname ~basename:f
  in
  let rec aux = function
    | [] -> link m; [libname]
    | m'::_ as l when DirPath.equal m' libname -> l
    | m'::l' -> m' :: aux l' in
  libraries_loaded_list := aux !libraries_loaded_list;
  libraries_table := LibraryMap.add libname m !libraries_table

  (* ... while if a library is imported/exported several time, then
     only the last occurrence is really needed - though the imported
     list may differ from the exported list (consider the sequence
     Export A; Export B; Import A which results in A;B for exports but
     in B;A for imports) *)

let rec remember_last_of_each l m =
  match l with
  | [] -> [m]
  | m'::l' when DirPath.equal m' m -> remember_last_of_each l' m
  | m'::l' -> m' :: remember_last_of_each l' m

let register_open_library export m =
  libraries_imports_list := remember_last_of_each !libraries_imports_list m;
  if export then
    libraries_exports_list := remember_last_of_each !libraries_exports_list m

(************************************************************************)
(*s Opening libraries *)

(* [open_library export explicit m] opens library [m] if not already
   opened _or_ if explicitly asked to be (re)opened *)

let open_library export explicit_libs m =
  if
    (* Only libraries indirectly to open are not reopen *)
    (* Libraries explicitly mentionned by the user are always reopen *)
    List.exists (fun m' -> DirPath.equal m m') explicit_libs
    || not (library_is_opened m)
  then begin
    register_open_library export m;
    Declaremods.really_import_module (MPfile m)
  end
  else
    if export then
      libraries_exports_list := remember_last_of_each !libraries_exports_list m

(* open_libraries recursively open a list of libraries but opens only once
   a library that is re-exported many times *)

let open_libraries export modl =
  let to_open_list =
    List.fold_left
      (fun l m ->
         let subimport =
           Array.fold_left
             (fun l m -> remember_last_of_each l m)
             l m.libsum_imports
         in remember_last_of_each subimport m.libsum_name)
      [] modl in
  let explicit = List.map (fun m -> m.libsum_name) modl in
  List.iter (open_library export explicit) to_open_list


(**********************************************************************)
(* import and export of libraries - synchronous operations            *)
(* at the end similar to import and export of modules except that it  *)
(* is optimized: when importing several libraries at the same time    *)
(* which themselves indirectly imports the very same modules, these   *)
(* ones are imported only ones *)

let open_import_library i (_,(modl,export)) =
  if Int.equal i 1 then
    (* even if the library is already imported, we re-import it *)
    (* if not (library_is_opened dir) then *)
      open_libraries export (List.map try_find_library modl)

let cache_import_library obj =
  open_import_library 1 obj

let subst_import_library (_,o) = o

let classify_import_library (_,export as obj) =
  if export then Substitute obj else Dispose

let in_import_library : DirPath.t list * bool -> obj =
  declare_object {(default_object "IMPORT LIBRARY") with
       cache_function = cache_import_library;
       open_function = open_import_library;
       subst_function = subst_import_library;
       classify_function = classify_import_library }


(************************************************************************)
(*s Locate absolute or partially qualified library names in the path *)

exception LibUnmappedDir
exception LibNotFound
type library_location = LibLoaded | LibInPath

let locate_absolute_library dir =
  (* Search in loadpath *)
  let pref, base = split_dirpath dir in
  let loadpath = Loadpath.filter_path (fun dir -> DirPath.equal dir pref) in
  let () = match loadpath with [] -> raise LibUnmappedDir | _ -> () in
  let loadpath = List.map fst loadpath in
  let find ext =
    try
      let name = Id.to_string base ^ ext in
      let _, file = System.where_in_path ~warn:false loadpath name in
      [file]
    with Not_found -> [] in
  match find ".vo" @ find ".vio" with
  | [] -> raise LibNotFound
  | [file] -> dir, file
  | [vo;vi] when Unix.((stat vo).st_mtime < (stat vi).st_mtime) ->
       msg_warning (str"Loading " ++ str vi ++ str " instead of " ++
         str vo ++ str " because it is more recent");
       dir, vi
  | [vo;vi] -> dir, vo
  | _ -> assert false

let locate_qualified_library ?root ?(warn = true) qid =
  (* Search library in loadpath *)
  let dir, base = repr_qualid qid in
  let loadpath = match root with
  | None -> Loadpath.expand_path dir
  | Some root ->
    let filter path =
      if is_dirpath_prefix_of root path then
        let path = drop_dirpath_prefix root path in
        is_dirpath_suffix_of dir path
      else false
    in
    Loadpath.filter_path filter
  in
  let () = match loadpath with [] -> raise LibUnmappedDir | _ -> () in
  let find ext =
    try
      let name = Id.to_string base ^ ext in
      let lpath, file =
        System.where_in_path ~warn (List.map fst loadpath) name in
      [lpath, file]
    with Not_found -> [] in
  let lpath, file =
    match find ".vo" @ find ".vio" with
    | [] -> raise LibNotFound
    | [lpath, file] -> lpath, file
    | [lpath_vo, vo; lpath_vi, vi]
      when Unix.((stat vo).st_mtime < (stat vi).st_mtime) ->
       msg_warning (str"Loading " ++ str vi ++ str " instead of " ++
         str vo ++ str " because it is more recent");
       lpath_vi, vi
    | [lpath_vo, vo; _ ] -> lpath_vo, vo
    | _ -> assert false
  in
  let dir = add_dirpath_suffix (String.List.assoc lpath loadpath) base in
  (* Look if loaded *)
  if library_is_loaded dir then (LibLoaded, dir,library_full_filename dir)
  (* Otherwise, look for it in the file system *)
  else (LibInPath, dir, file)

let error_unmapped_dir qid =
  let prefix, _ = repr_qualid qid in
  errorlabstrm "load_absolute_library_from"
    (str "Cannot load " ++ pr_qualid qid ++ str ":" ++ spc () ++
     str "no physical path bound to" ++ spc () ++ pr_dirpath prefix ++ fnl ())

let error_lib_not_found qid =
  errorlabstrm "load_absolute_library_from"
    (str"Cannot find library " ++ pr_qualid qid ++ str" in loadpath")

let try_locate_absolute_library dir =
  try
    locate_absolute_library dir
  with
    | LibUnmappedDir -> error_unmapped_dir (qualid_of_dirpath dir)
    | LibNotFound -> error_lib_not_found (qualid_of_dirpath dir)

(************************************************************************)
(** {6 Tables of opaque proof terms} *)

(** We now store opaque proof terms apart from the rest of the environment.
    See the [Indirect] contructor in [Lazyconstr.lazy_constr]. This way,
    we can quickly load a first half of a .vo file without these opaque
    terms, and access them only when a specific command (e.g. Print or
    Print Assumptions) needs it. *)

(** Delayed / available tables of opaque terms *)

type 'a table_status =
  | ToFetch of 'a Future.computation array delayed
  | Fetched of 'a Future.computation array

let opaque_tables =
  ref (LibraryMap.empty : (Term.constr table_status) LibraryMap.t)
let univ_tables =
  ref (LibraryMap.empty : (Univ.universe_context_set table_status) LibraryMap.t)

let add_opaque_table dp st =
  opaque_tables := LibraryMap.add dp st !opaque_tables
let add_univ_table dp st =
  univ_tables := LibraryMap.add dp st !univ_tables

let access_table what tables dp i =
  let t = match LibraryMap.find dp !tables with
    | Fetched t -> t
    | ToFetch f ->
      let dir_path = Names.DirPath.to_string dp in
      Flags.if_verbose msg_info (str"Fetching " ++ str what++str" from disk for " ++ str dir_path);
      let t =
        try fetch_delayed f
        with Faulty f ->
          errorlabstrm "Library.access_table"
            (str "The file " ++ str f ++ str " (bound to " ++ str dir_path ++
             str ") is inaccessible or corrupted,\ncannot load some " ++
             str what ++ str " in it.\n")
      in
      tables := LibraryMap.add dp (Fetched t) !tables;
      t
  in
  assert (i < Array.length t); t.(i)

let access_opaque_table dp i =
  let what = "opaque proofs" in
  access_table what opaque_tables dp i

let access_univ_table dp i =
  try
    let what = "universe contexts of opaque proofs" in
    Some (access_table what univ_tables dp i)
  with Not_found -> None

let () =
  Opaqueproof.set_indirect_opaque_accessor access_opaque_table;
  Opaqueproof.set_indirect_univ_accessor access_univ_table

(************************************************************************)
(* Internalise libraries *)

type seg_sum = summary_disk
type seg_lib = library_disk
type seg_univ = (* true = vivo, false = vi *)
  Univ.universe_context_set Future.computation array * Univ.universe_context_set * bool
type seg_discharge = Opaqueproof.cooking_info list array
type seg_proofs = Term.constr Future.computation array

let mk_library sd md digests univs =
  {
    library_name     = sd.md_name;
    library_data     = md;
    library_deps     = sd.md_deps;
    library_imports  = sd.md_imports;
    library_digests  = digests;
    library_extra_univs = univs;
  }

let mk_summary m = {
  libsum_name = m.library_name;
  libsum_imports = m.library_imports;
  libsum_digests = m.library_digests;
}

let intern_from_file f =
  let ch = raw_intern_library f in
  let (lsd : seg_sum), _, digest_lsd = System.marshal_in_segment f ch in
  let (lmd : seg_lib delayed) = in_delayed f ch in
  let (univs : seg_univ option), _, digest_u = System.marshal_in_segment f ch in
  let _ = System.skip_in_segment f ch in
  let _ = System.skip_in_segment f ch in
  let (del_opaque : seg_proofs delayed) = in_delayed f ch in
  close_in ch;
  register_library_filename lsd.md_name f;
  add_opaque_table lsd.md_name (ToFetch del_opaque);
  let open Safe_typing in
  match univs with
  | None -> mk_library lsd lmd (Dvo_or_vi digest_lsd) Univ.ContextSet.empty
  | Some (utab,uall,true) ->
      add_univ_table lsd.md_name (Fetched utab);
      mk_library lsd lmd (Dvivo (digest_lsd,digest_u)) uall
  | Some (utab,_,false) ->
      add_univ_table lsd.md_name (Fetched utab);
      mk_library lsd lmd (Dvo_or_vi digest_lsd) Univ.ContextSet.empty

module DPMap = Map.Make(DirPath)

let rec intern_library (needed, contents) (dir, f) from =
  Pp.feedback(Feedback.FileDependency (from, f));
  (* Look if in the current logical environment *)
  try (find_library dir).libsum_digests, (needed, contents)
  with Not_found ->
  (* Look if already listed and consequently its dependencies too *)
  try (DPMap.find dir contents).library_digests, (needed, contents)
  with Not_found ->
  (* [dir] is an absolute name which matches [f] which must be in loadpath *)
  let m = intern_from_file f in
  if not (DirPath.equal dir m.library_name) then
    errorlabstrm "load_physical_library"
      (str "The file " ++ str f ++ str " contains library" ++ spc () ++
       pr_dirpath m.library_name ++ spc () ++ str "and not library" ++
       spc() ++ pr_dirpath dir);
  Pp.feedback(Feedback.FileLoaded(DirPath.to_string dir, f));
  m.library_digests, intern_library_deps (needed, contents) dir m (Some f)

and intern_library_deps libs dir m from =
  let needed, contents = Array.fold_left (intern_mandatory_library dir from) libs m.library_deps in
  (dir :: needed, DPMap.add dir m contents )

and intern_mandatory_library caller from libs (dir,d) =
  let digest, libs = intern_library libs (try_locate_absolute_library dir) from in
  if not (Safe_typing.digest_match ~actual:digest ~required:d) then
    errorlabstrm "" (str "Compiled library " ++ str (DirPath.to_string caller) ++ str ".vo makes inconsistent assumptions over library " ++ str (DirPath.to_string dir));
  libs

let rec_intern_library libs mref =
  let _, libs = intern_library libs mref None in
  libs

let native_name_from_filename f =
  let ch = raw_intern_library f in
  let (lmd : seg_sum), pos, digest_lmd = System.marshal_in_segment f ch in
  Nativecode.mod_uid_of_dirpath lmd.md_name

(**********************************************************************)
(*s [require_library] loads and possibly opens a library. This is a
    synchronized operation. It is performed as follows:

  preparation phase: (functions require_library* ) the library and its
    dependencies are read from to disk (using intern_* )
    [they are read from disk to ensure that at section/module
     discharging time, the physical library referred to outside the
     section/module is the one that was used at type-checking time in
     the section/module]

  execution phase: (through add_leaf and cache_require)
    the library is loaded in the environment and Nametab, the objects are
    registered etc, using functions from Declaremods (via load_library,
    which recursively loads its dependencies)
*)

let register_library m =
  let l = fetch_delayed m.library_data in
  Declaremods.register_library
    m.library_name
    l.md_compiled
    l.md_objects
    m.library_digests
    m.library_extra_univs;
  register_loaded_library (mk_summary m)

(* Follow the semantics of Anticipate object:
   - called at module or module type closing when a Require occurs in
     the module or module type
   - not called from a library (i.e. a module identified with a file) *)
let load_require _ (_,(needed,modl,_)) =
  List.iter register_library needed

let open_require i (_,(_,modl,export)) =
  Option.iter (fun exp -> open_libraries exp (List.map find_library modl))
    export

  (* [needed] is the ordered list of libraries not already loaded *)
let cache_require o =
  load_require 1 o;
  open_require 1 o

let discharge_require (_,o) = Some o

(* open_function is never called from here because an Anticipate object *)

type require_obj = library_t list * DirPath.t list * bool option

let in_require : require_obj -> obj =
  declare_object {(default_object "REQUIRE") with
       cache_function = cache_require;
       load_function = load_require;
       open_function = (fun _ _ -> assert false);
       discharge_function = discharge_require;
       classify_function = (fun o -> Anticipate o) }

(* Require libraries, import them if [export <> None], mark them for export
   if [export = Some true] *)

let require_library_from_dirpath modrefl export =
  let needed, contents = List.fold_left rec_intern_library ([], DPMap.empty) modrefl in
  let needed = List.rev_map (fun dir -> DPMap.find dir contents) needed in
  let modrefl = List.map fst modrefl in
    if Lib.is_module_or_modtype () then
      begin
	add_anonymous_leaf (in_require (needed,modrefl,None));
	Option.iter (fun exp ->
	  add_anonymous_leaf (in_import_library (modrefl,exp)))
	  export
      end
    else
      add_anonymous_leaf (in_require (needed,modrefl,export));
  add_frozen_state ()

(* the function called by Vernacentries.vernac_import *)

let safe_locate_module (loc,qid) =
  try Nametab.locate_module qid
  with Not_found ->
    user_err_loc
      (loc,"import_library", str (string_of_qualid qid) ++ str " is not a module")

let import_module export modl =
  (* Optimization: libraries in a raw in the list are imported
     "globally".  If there is non-library in the list; it breaks the
     optimization For instance: "Import Arith MyModule Zarith" will
     not be optimized (possibly resulting in redefinitions, but
     "Import MyModule Arith Zarith" and "Import Arith Zarith MyModule"
     will have the submodules imported by both Arith and ZArith
     imported only once *)
  let flush = function
    | [] -> ()
    | modl -> add_anonymous_leaf (in_import_library (List.rev modl, export)) in
  let rec aux acc = function
    | (loc,dir as m) :: l ->
        let m,acc =
          try Nametab.locate_module dir, acc
          with Not_found-> flush acc; safe_locate_module m, [] in
        (match m with
        | MPfile dir -> aux (dir::acc) l
        | mp ->
            flush acc;
            try Declaremods.import_module export mp; aux [] l
            with Not_found ->
              user_err_loc (loc,"import_library",
                str (string_of_qualid dir) ++ str " is not a module"))
    | [] -> flush acc
  in aux [] modl

(************************************************************************)
(*s Initializing the compilation of a library. *)

let check_coq_overwriting p id =
  let l = DirPath.repr p in
  let is_empty = match l with [] -> true | _ -> false in
  if not !Flags.boot && not is_empty && String.equal (Id.to_string (List.last l)) "Coq" then
    errorlabstrm ""
      (str "Cannot build module " ++ str (DirPath.to_string p) ++ str "." ++ pr_id id ++ str "." ++ spc () ++
      str "it starts with prefix \"Coq\" which is reserved for the Coq library.")

(* Verifies that a string starts by a letter and do not contain
   others caracters than letters, digits, or `_` *)

let check_module_name s =
  let msg c =
    strbrk "Invalid module name: " ++ str s ++ strbrk " character " ++
    (if c = '\'' then str "\"'\"" else (str "'" ++ str (String.make 1 c) ++ str "'")) ++
    strbrk " is not allowed in module names\n"
  in
  let err c = errorlabstrm "" (msg c) in
  match String.get s 0 with
    | 'a' .. 'z' | 'A' .. 'Z' ->
        for i = 1 to (String.length s)-1 do
          match String.get s i with
            | 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_'  -> ()
            | c -> err c
        done
    | c -> err c

let start_library f =
  let () = if not (Sys.file_exists f) then
    errorlabstrm "" (hov 0 (str "Can't find file" ++ spc () ++ str f))
  in
  let ldir0 =
    try
      let lp = Loadpath.find_load_path (Filename.dirname f) in
      Loadpath.logical lp
    with Not_found -> Nameops.default_root_prefix
  in
  let file = Filename.chop_extension (Filename.basename f) in
  let id = Id.of_string file in
  check_module_name file;
  check_coq_overwriting ldir0 id;
  let ldir = add_dirpath_suffix ldir0 id in
  Declaremods.start_library ldir;
  ldir

let load_library_todo f =
  let longf = Loadpath.locate_file (f^".v") in
  let f = longf^"io" in
  let ch = raw_intern_library f in
  let (s0 : seg_sum), _, _ = System.marshal_in_segment f ch in
  let (s1 : seg_lib), _, _ = System.marshal_in_segment f ch in
  let (s2 : seg_univ option), _, _ = System.marshal_in_segment f ch in
  let (s3 : seg_discharge option), _, _ = System.marshal_in_segment f ch in
  let tasks, _, _ = System.marshal_in_segment f ch in
  let (s5 : seg_proofs), _, _ = System.marshal_in_segment f ch in
  close_in ch;
  if tasks = None then errorlabstrm "restart" (str"not a .vio file");
  if s2 = None then errorlabstrm "restart" (str"not a .vio file");
  if s3 = None then errorlabstrm "restart" (str"not a .vio file");
  if pi3 (Option.get s2) then errorlabstrm "restart" (str"not a .vio file");
  longf, s0, s1, Option.get s2, Option.get s3, Option.get tasks, s5

(************************************************************************)
(*s [save_library dir] ends library [dir] and save it to the disk. *)

let current_deps () =
  let map name =
    let m = try_find_library name in
    (name, m.libsum_digests)
  in
  List.map map !libraries_loaded_list

let current_reexports () = !libraries_exports_list

let error_recursively_dependent_library dir =
  errorlabstrm ""
    (strbrk "Unable to use logical name " ++ pr_dirpath dir ++
     strbrk " to save current library because" ++
     strbrk " it already depends on a library of this name.")

(* We now use two different digests in a .vo file. The first one
   only covers half of the file, without the opaque table. It is
   used for identifying this version of this library : this digest
   is the one leading to "inconsistent assumptions" messages.
   The other digest comes at the very end, and covers everything
   before it. This one is used for integrity check of the whole
   file when loading the opaque table. *)

(* Security weakness: file might have been changed on disk between
   writing the content and computing the checksum... *)

let save_library_to ?todo dir f otab =
  let f, except = match todo with
    | None ->
        assert(!Flags.compilation_mode = Flags.BuildVo);
        f ^ "o", Future.UUIDSet.empty
    | Some (l,_) ->
        f ^ "io",
        List.fold_left (fun e (r,_) -> Future.UUIDSet.add r.Stateid.uuid e)
          Future.UUIDSet.empty l in
  let cenv, seg, ast = Declaremods.end_library ~except dir in
  let opaque_table, univ_table, disch_table, f2t_map = Opaqueproof.dump otab in
  let tasks, utab, dtab =
    match todo with
    | None -> None, None, None
    | Some (tasks, rcbackup) ->
        let tasks =
          List.map Stateid.(fun (r,b) ->
            try { r with uuid = Future.UUIDMap.find r.uuid f2t_map }, b
            with Not_found -> assert b; { r with uuid = -1 }, b)
          tasks in
        Some (tasks,rcbackup),
        Some (univ_table,Univ.ContextSet.empty,false),
        Some disch_table in
  let except =
    Future.UUIDSet.fold (fun uuid acc ->
      try Int.Set.add (Future.UUIDMap.find uuid f2t_map) acc
      with Not_found -> acc)
      except Int.Set.empty in
  let is_done_or_todo i x = Future.is_val x || Int.Set.mem i except in
  Array.iteri (fun i x ->
    if not(is_done_or_todo i x) then Errors.errorlabstrm "library"
      Pp.(str"Proof object "++int i++str" is not checked nor to be checked"))
    opaque_table;
  let sd = {
    md_name = dir;
    md_deps = Array.of_list (current_deps ());
    md_imports = Array.of_list (current_reexports ());
  } in
  let md = {
    md_compiled = cenv;
    md_objects = seg;
  } in
  if Array.exists (fun (d,_) -> DirPath.equal d dir) sd.md_deps then
    error_recursively_dependent_library dir;
  (* Open the vo file and write the magic number *)
  let f' = f in
  let ch = raw_extern_library f' in
  try
    (* Writing vo payload *)
    System.marshal_out_segment f' ch (sd           : seg_sum);
    System.marshal_out_segment f' ch (md           : seg_lib);
    System.marshal_out_segment f' ch (utab         : seg_univ option);
    System.marshal_out_segment f' ch (dtab         : seg_discharge option);
    System.marshal_out_segment f' ch (tasks        : 'tasks option);
    System.marshal_out_segment f' ch (opaque_table : seg_proofs);
    close_out ch;
    (* Writing native code files *)
    if !Flags.native_compiler then
      let fn = Filename.dirname f'^"/"^Nativecode.mod_uid_of_dirpath dir in
      if not (Nativelib.compile_library dir ast fn) then
	error "Could not compile the library to native code."
   with reraise ->
    let reraise = Errors.push reraise in
    let () = msg_warning (str "Removed file " ++ str f') in
    let () = close_out ch in
    let () = Sys.remove f' in
    iraise reraise

let save_library_raw f sum lib univs proofs =
  let f' = f^"o" in
  let ch = raw_extern_library f' in
  System.marshal_out_segment f' ch (sum        : seg_sum);
  System.marshal_out_segment f' ch (lib        : seg_lib);
  System.marshal_out_segment f' ch (Some univs : seg_univ option);
  System.marshal_out_segment f' ch (None       : seg_discharge option);
  System.marshal_out_segment f' ch (None       : 'tasks option);
  System.marshal_out_segment f' ch (proofs     : seg_proofs);
  close_out ch

(************************************************************************)
(*s Display the memory use of a library. *)

open Printf

let mem s = Pp.mt ()

module StringOrd = struct type t = string let compare = String.compare end
module StringSet = Set.Make(StringOrd)

let get_used_load_paths () =
  StringSet.elements
    (List.fold_left (fun acc m -> StringSet.add
      (Filename.dirname (library_full_filename m)) acc)
       StringSet.empty !libraries_loaded_list)

let _ = Nativelib.get_load_paths := get_used_load_paths