File: iconvconfig.c

package info (click to toggle)
glibc 2.23-4
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 233,552 kB
  • sloc: ansic: 987,702; asm: 260,118; sh: 10,380; makefile: 9,474; python: 3,957; cpp: 3,956; perl: 2,207; awk: 1,907; pascal: 1,527; yacc: 291; sed: 80
file content (1245 lines) | stat: -rw-r--r-- 31,614 bytes parent folder | download | duplicates (5)
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
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
/* Generate fastloading iconv module configuration files.
   Copyright (C) 2000-2016 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2000.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published
   by the Free Software Foundation; version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.  */

#include <argp.h>
#include <assert.h>
#include <error.h>
#include <errno.h>
#include <fcntl.h>
#include <libintl.h>
#include <locale.h>
#include <mcheck.h>
#include <search.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/cdefs.h>
#include <sys/uio.h>

#include "iconvconfig.h"

/* Get libc version number.  */
#include "../version.h"

#define PACKAGE _libc_intl_domainname


/* The hashing function we use.  */
#include "../intl/hash-string.h"


/* Types used.  */
struct module
{
  char *fromname;
  struct Strent *fromname_strent;
  char *filename;
  struct Strent *filename_strent;
  const char *directory;
  struct Strent *directory_strent;
  struct module *next;
  int cost;
  struct Strent *toname_strent;
  char toname[0];
};

struct alias
{
  char *fromname;
  struct Strent *froment;
  struct module *module;
  struct Strent *toent;
  char toname[0];
};

struct name
{
  const char *name;
  struct Strent *strent;
  int module_idx;
  uint32_t hashval;
};

struct name_info
{
  const char *canonical_name;
  struct Strent *canonical_strent;

  struct module *from_internal;
  struct module *to_internal;

  struct other_conv_list
  {
    int dest_idx;
    struct other_conv
    {
      gidx_t module_idx;
      struct module *module;
      struct other_conv *next;
    } other_conv;
    struct other_conv_list *next;
  } *other_conv_list;
};


/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

/* Short description of program.  */
static const char doc[] = N_("\
Create fastloading iconv module configuration file.");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("[DIR...]");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Function to print some extra text in the help message.  */
static char *more_help (int key, const char *text, void *input);

/* Definitions of arguments for argp functions.  */
#define OPT_PREFIX 300
#define OPT_NOSTDLIB 301
static const struct argp_option options[] =
{
  { "prefix", OPT_PREFIX, N_("PATH"), 0,
    N_("Prefix used for all file accesses") },
  { "output", 'o', N_("FILE"), 0, N_("\
Put output in FILE instead of installed location\
 (--prefix does not apply to FILE)") },
  { "nostdlib", OPT_NOSTDLIB, NULL, 0,
    N_("Do not search standard directories, only those on the command line") },
  { NULL, 0, NULL, 0, NULL }
};

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, NULL, more_help
};


/* The function doing the actual work.  */
static int handle_dir (const char *dir);

/* Add all known builtin conversions and aliases.  */
static void add_builtins (void);

/* Create list of all aliases without circular aliases.  */
static void get_aliases (void);

/* Create list of all modules.  */
static void get_modules (void);

/* Get list of all the names and thereby indexing them.  */
static void generate_name_list (void);

/* Collect information about all the names.  */
static void generate_name_info (void);

/* Write the output file.  */
static int write_output (void);


/* Prefix to be used for all file accesses.  */
static const char *prefix = "";
/* Its length.  */
static size_t prefix_len;

/* Directory to place output file in.  */
static const char *output_file;
/* Its length.  */
static size_t output_file_len;

/* If true, omit the GCONV_PATH directories and require some arguments.  */
static bool nostdlib;

/* Search tree of the modules we know.  */
static void *modules;

/* Search tree of the aliases we know.  */
static void *aliases;

/* Search tree for name to index mapping.  */
static void *names;

/* Number of names we know about.  */
static int nnames;

/* List of all aliases.  */
static struct alias **alias_list;
static size_t nalias_list;
static size_t nalias_list_max;

/* List of all modules.  */
static struct module **module_list;
static size_t nmodule_list;
static size_t nmodule_list_max;

/* Names and information about them.  */
static struct name_info *name_info;
static size_t nname_info;

/* Number of translations not from or to INTERNAL.  */
static size_t nextra_modules;


/* Names and aliases for the builtin transformations.  */
static struct
{
  const char *from;
  const char *to;
} builtin_alias[] =
  {
#define BUILTIN_ALIAS(alias, real) \
    { .from = alias, .to = real },
#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
			       MinF, MaxF, MinT, MaxT)
#include <gconv_builtin.h>
  };
#undef BUILTIN_ALIAS
#undef BUILTIN_TRANSFORMATION
#define nbuiltin_alias (sizeof (builtin_alias) / sizeof (builtin_alias[0]))

static struct
{
  const char *from;
  const char *to;
  const char *module;
  int cost;
} builtin_trans[] =
  {
#define BUILTIN_ALIAS(alias, real)
#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
			       MinF, MaxF, MinT, MaxT) \
    { .from = From, .to = To, .module = Name, .cost = Cost },
#include <gconv_builtin.h>
  };
#undef BUILTIN_ALIAS
#undef BUILTIN_TRANSFORMATION
#define nbuiltin_trans (sizeof (builtin_trans) / sizeof (builtin_trans[0]))


/* Filename extension for the modules.  */
#ifndef MODULE_EXT
# define MODULE_EXT ".so"
#endif
static const char gconv_module_ext[] = MODULE_EXT;


#include <programs/xmalloc.h>


/* C string table handling.  */
struct Strtab;
struct Strent;

/* Create new C string table object in memory.  */
extern struct Strtab *strtabinit (void);

/* Free resources allocated for C string table ST.  */
extern void strtabfree (struct Strtab *st);

/* Add string STR (length LEN is != 0) to C string table ST.  */
extern struct Strent *strtabadd (struct Strtab *st, const char *str,
				 size_t len);

/* Finalize string table ST and store size in *SIZE and return a pointer.  */
extern void *strtabfinalize (struct Strtab *st, size_t *size);

/* Get offset in string table for string associated with SE.  */
extern size_t strtaboffset (struct Strent *se);

/* String table we construct.  */
static struct Strtab *strtab;



int
main (int argc, char *argv[])
{
  int remaining;
  int status = 0;

  /* Enable memory use testing.  */
  /* mcheck_pedantic (NULL); */
  mtrace ();

  /* Set locale via LC_ALL.  */
  setlocale (LC_ALL, "");

  /* Set the text message domain.  */
  textdomain (_libc_intl_domainname);

  /* Parse and process arguments.  */
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  if (nostdlib && remaining == argc)
    error (2, 0, _("Directory arguments required when using --nostdlib"));

  /* Initialize the string table.  */
  strtab = strtabinit ();

  /* Handle all directories mentioned.  */
  while (remaining < argc)
    status |= handle_dir (argv[remaining++]);

  if (! nostdlib)
    {
      /* In any case also handle the standard directory.  */
      char *path = strdupa (GCONV_PATH), *tp = strsep (&path, ":");
      while (tp != NULL)
	{
	  status |= handle_dir (tp);

	  tp = strsep (&path, ":");
	}
    }

  /* Add the builtin transformations and aliases without overwriting
     anything.  */
  add_builtins ();

  /* Store aliases in an array.  */
  get_aliases ();

  /* Get list of all modules.  */
  get_modules ();

  /* Generate list of all the names we know to handle in some way.  */
  generate_name_list ();

  /* Now we know all the names we will handle, collect information
     about them.  */
  generate_name_info ();

  /* Write the output file, but only if we haven't seen any error.  */
  if (status == 0)
    status = write_output ();
  else
    error (1, 0, _("no output file produced because warnings were issued"));

  return status;
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case OPT_PREFIX:
      prefix = arg;
      prefix_len = strlen (prefix);
      break;
    case 'o':
      output_file = arg;
      output_file_len = strlen (output_file);
      break;
    case OPT_NOSTDLIB:
      nostdlib = true;
      break;
    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}


static char *
more_help (int key, const char *text, void *input)
{
  char *tp = NULL;
  switch (key)
    {
    case ARGP_KEY_HELP_EXTRA:
      /* We print some extra information.  */
      if (asprintf (&tp, gettext ("\
For bug reporting instructions, please see:\n\
%s.\n"), REPORT_BUGS_TO) < 0)
	return NULL;
      return tp;
    default:
      break;
    }
  return (char *) text;
}


/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "iconvconfig %s%s\n", PKGVERSION, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2016");
  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}


static int
alias_compare (const void *p1, const void *p2)
{
  const struct alias *a1 = (const struct alias *) p1;
  const struct alias *a2 = (const struct alias *) p2;

  return strcmp (a1->fromname, a2->fromname);
}


static void
new_alias (const char *fromname, size_t fromlen, const char *toname,
	   size_t tolen)
{
  struct alias *newp;
  void **inserted;

  newp = (struct alias *) xmalloc (sizeof (struct alias) + fromlen + tolen);

  newp->fromname = mempcpy (newp->toname, toname, tolen);
  memcpy (newp->fromname, fromname, fromlen);
  newp->module = NULL;

  inserted = (void **) tsearch (newp, &aliases, alias_compare);
  if (inserted == NULL)
    error (EXIT_FAILURE, errno, gettext ("while inserting in search tree"));
  if (*inserted != newp)
    /* Something went wrong, free this entry.  */
    free (newp);
  else
    {
      newp->froment = strtabadd (strtab, newp->fromname, fromlen);
      newp->toent = strtabadd (strtab, newp->toname, tolen);
    }
}


/* Add new alias.  */
static void
add_alias (char *rp)
{
  /* We now expect two more string.  The strings are normalized
     (converted to UPPER case) and strored in the alias database.  */
  char *from;
  char *to;
  char *wp;

  while (isspace (*rp))
    ++rp;
  from = wp = rp;
  while (*rp != '\0' && !isspace (*rp))
    *wp++ = toupper (*rp++);
  if (*rp == '\0')
    /* There is no `to' string on the line.  Ignore it.  */
    return;
  *wp++ = '\0';
  to = ++rp;
  while (isspace (*rp))
    ++rp;
  while (*rp != '\0' && !isspace (*rp))
    *wp++ = toupper (*rp++);
  if (to == wp)
    /* No `to' string, ignore the line.  */
    return;
  *wp++ = '\0';

  assert (strlen (from) + 1 == (size_t) (to - from));
  assert (strlen (to) + 1 == (size_t) (wp - to));

  new_alias (from, to - from, to, wp - to);
}


static void
append_alias (const void *nodep, VISIT value, int level)
{
  if (value != leaf && value != postorder)
    return;

  if (nalias_list_max == nalias_list)
    {
      nalias_list_max += 50;
      alias_list = (struct alias **) xrealloc (alias_list,
					       (nalias_list_max
						* sizeof (struct alias *)));
    }

  alias_list[nalias_list++] = *(struct alias **) nodep;
}


static void
get_aliases (void)
{
  twalk (aliases, append_alias);
}


static int
module_compare (const void *p1, const void *p2)
{
  const struct module *m1 = (const struct module *) p1;
  const struct module *m2 = (const struct module *) p2;
  int result;

  result = strcmp (m1->fromname, m2->fromname);
  if (result == 0)
    result = strcmp (m1->toname, m2->toname);

  return result;
}


/* Create new module record.  */
static void
new_module (const char *fromname, size_t fromlen, const char *toname,
	    size_t tolen, const char *directory,
	    const char *filename, size_t filelen, int cost, size_t need_ext)
{
  struct module *new_module;
  size_t dirlen = strlen (directory) + 1;
  char *tmp;
  void **inserted;

  new_module = (struct module *) xmalloc (sizeof (struct module)
					  + fromlen + tolen + filelen
					  + need_ext);

  new_module->fromname = mempcpy (new_module->toname, toname, tolen);

  new_module->filename = mempcpy (new_module->fromname, fromname, fromlen);

  new_module->cost = cost;
  new_module->next = NULL;

  tmp = mempcpy (new_module->filename, filename, filelen);
  if (need_ext)
    {
      memcpy (tmp - 1, gconv_module_ext, need_ext + 1);
      filelen += need_ext;
    }
  new_module->directory = directory;

  /* Now insert the new module data structure in our search tree.  */
  inserted = (void **) tsearch (new_module, &modules, module_compare);
  if (inserted == NULL)
    error (EXIT_FAILURE, errno, "while inserting in search tree");
  if (*inserted != new_module)
    free (new_module);
  else
    {
      new_module->fromname_strent = strtabadd (strtab, new_module->fromname,
					       fromlen);
      new_module->toname_strent = strtabadd (strtab, new_module->toname,
					     tolen);
      new_module->filename_strent = strtabadd (strtab, new_module->filename,
					       filelen);
      new_module->directory_strent = strtabadd (strtab, directory, dirlen);
    }
}


/* Add new module.  */
static void
internal_function
add_module (char *rp, const char *directory)
{
  /* We expect now
     1. `from' name
     2. `to' name
     3. filename of the module
     4. an optional cost value
  */
  char *from;
  char *to;
  char *module;
  char *wp;
  int need_ext;
  int cost;

  while (isspace (*rp))
    ++rp;
  from = rp;
  while (*rp != '\0' && !isspace (*rp))
    {
      *rp = toupper (*rp);
      ++rp;
    }
  if (*rp == '\0')
    return;
  *rp++ = '\0';
  to = wp = rp;
  while (isspace (*rp))
    ++rp;
  while (*rp != '\0' && !isspace (*rp))
    *wp++ = toupper (*rp++);
  if (*rp == '\0')
    return;
  *wp++ = '\0';
  do
    ++rp;
  while (isspace (*rp));
  module = wp;
  while (*rp != '\0' && !isspace (*rp))
    *wp++ = *rp++;
  if (*rp == '\0')
    {
      /* There is no cost, use one by default.  */
      *wp++ = '\0';
      cost = 1;
    }
  else
    {
      /* There might be a cost value.  */
      char *endp;

      *wp++ = '\0';
      cost = strtol (rp, &endp, 10);
      if (rp == endp || cost < 1)
	/* No useful information.  */
	cost = 1;
    }

  if (module[0] == '\0')
    /* No module name given.  */
    return;

  /* See whether we must add the ending.  */
  need_ext = 0;
  if ((size_t) (wp - module) < sizeof (gconv_module_ext)
      || memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext,
		 sizeof (gconv_module_ext)) != 0)
    /* We must add the module extension.  */
    need_ext = sizeof (gconv_module_ext) - 1;

  assert (strlen (from) + 1 == (size_t) (to - from));
  assert (strlen (to) + 1 == (size_t) (module - to));
  assert (strlen (module) + 1 == (size_t) (wp - module));

  new_module (from, to - from, to, module - to, directory, module, wp - module,
	      cost, need_ext);
}


/* Read the config file and add the data for this directory to that.  */
static int
handle_dir (const char *dir)
{
  char *cp;
  FILE *fp;
  char *line = NULL;
  size_t linelen = 0;
  size_t dirlen = strlen (dir);

  if (dir[dirlen - 1] != '/')
    {
      char *newp = (char *) xmalloc (dirlen + 2);
      dir = memcpy (newp, dir, dirlen);
      newp[dirlen++] = '/';
      newp[dirlen] = '\0';
    }

  char infile[prefix_len + dirlen + sizeof "gconv-modules"];
  cp = infile;
  if (dir[0] == '/')
    cp = mempcpy (cp, prefix, prefix_len);
  strcpy (mempcpy (cp, dir, dirlen), "gconv-modules");

  fp = fopen (infile, "r");
  if (fp == NULL)
    {
      error (0, errno, "cannot open `%s'", infile);
      return 1;
    }

  /* No threads present.  */
  __fsetlocking (fp, FSETLOCKING_BYCALLER);

  while (!feof_unlocked (fp))
    {
      char *rp, *endp, *word;
      ssize_t n = __getdelim (&line, &linelen, '\n', fp);

      if (n < 0)
	/* An error occurred.  */
	break;

      rp = line;
      /* Terminate the line (excluding comments or newline) with a NUL
	 byte to simplify the following code.  */
      endp = strchr (rp, '#');
      if (endp != NULL)
	*endp = '\0';
      else
	if (rp[n - 1] == '\n')
	  rp[n - 1] = '\0';

      while (isspace (*rp))
	++rp;

      /* If this is an empty line go on with the next one.  */
      if (rp == endp)
	continue;

      word = rp;
      while (*rp != '\0' && !isspace (*rp))
	++rp;

      if (rp - word == sizeof ("alias") - 1
	  && memcmp (word, "alias", sizeof ("alias") - 1) == 0)
	add_alias (rp);
      else if (rp - word == sizeof ("module") - 1
	       && memcmp (word, "module", sizeof ("module") - 1) == 0)
	add_module (rp, dir);
      /* else */
	/* Otherwise ignore the line.  */
    }

  free (line);

  fclose (fp);

  return 0;
}


static void
append_module (const void *nodep, VISIT value, int level)
{
  struct module *mo;

  if (value != leaf && value != postorder)
    return;

  mo = *(struct module **) nodep;

  if (nmodule_list > 0
      && strcmp (module_list[nmodule_list - 1]->fromname, mo->fromname) == 0)
    {
      /* Same name.  */
      mo->next = module_list[nmodule_list - 1];
      module_list[nmodule_list - 1] = mo;

      return;
    }

  if (nmodule_list_max == nmodule_list)
    {
      nmodule_list_max += 50;
      module_list = (struct module **) xrealloc (module_list,
						 (nmodule_list_max
						  * sizeof (struct module *)));
    }

  module_list[nmodule_list++] = mo;
}


static void
get_modules (void)
{
  twalk (modules, append_module);
}


static void
add_builtins (void)
{
  size_t cnt;

  /* Add all aliases.  */
  for (cnt = 0; cnt < nbuiltin_alias; ++cnt)
    new_alias (builtin_alias[cnt].from,
	       strlen (builtin_alias[cnt].from) + 1,
	       builtin_alias[cnt].to,
	       strlen (builtin_alias[cnt].to) + 1);

  /* add the builtin transformations.  */
  for (cnt = 0; cnt < nbuiltin_trans; ++cnt)
    new_module (builtin_trans[cnt].from,
		strlen (builtin_trans[cnt].from) + 1,
		builtin_trans[cnt].to,
		strlen (builtin_trans[cnt].to) + 1,
		"", builtin_trans[cnt].module,
		strlen (builtin_trans[cnt].module) + 1,
		builtin_trans[cnt].cost, 0);
}


static int
name_compare (const void *p1, const void *p2)
{
  const struct name *n1 = (const struct name *) p1;
  const struct name *n2 = (const struct name *) p2;

  return strcmp (n1->name, n2->name);
}


static struct name *
new_name (const char *str, struct Strent *strent)
{
  struct name *newp = (struct name *) xmalloc (sizeof (struct name));

  newp->name = str;
  newp->strent = strent;
  newp->module_idx = -1;
  newp->hashval = __hash_string (str);

  ++nnames;

  return newp;
}


static void
generate_name_list (void)
{
  size_t i;

  /* A name we always need.  */
  tsearch (new_name ("INTERNAL", strtabadd (strtab, "INTERNAL",
					    sizeof ("INTERNAL"))),
	   &names, name_compare);

  for (i = 0; i < nmodule_list; ++i)
    {
      struct module *runp;

      if (strcmp (module_list[i]->fromname, "INTERNAL") != 0)
	tsearch (new_name (module_list[i]->fromname,
			   module_list[i]->fromname_strent),
		 &names, name_compare);

      for (runp = module_list[i]; runp != NULL; runp = runp->next)
	if (strcmp (runp->toname, "INTERNAL") != 0)
	  tsearch (new_name (runp->toname, runp->toname_strent),
		   &names, name_compare);
    }
}


static int
name_to_module_idx (const char *name, int add)
{
  struct name **res;
  struct name fake_name = { .name = name };
  int idx;

  res = (struct name **) tfind (&fake_name, &names, name_compare);
  if (res == NULL)
    abort ();

  idx = (*res)->module_idx;
  if (idx == -1 && add)
    /* No module index assigned yet.  */
    idx = (*res)->module_idx = nname_info++;

  return idx;
}


static void
generate_name_info (void)
{
  size_t i;
  int idx;

  name_info = (struct name_info *) xcalloc (nmodule_list + 1,
					    sizeof (struct name_info));

  /* First add a special entry for the INTERNAL name.  This must have
     index zero.  */
  idx = name_to_module_idx ("INTERNAL", 1);
  name_info[0].canonical_name = "INTERNAL";
  name_info[0].canonical_strent = strtabadd (strtab, "INTERNAL",
					     sizeof ("INTERNAL"));
  assert (nname_info == 1);

  for (i = 0; i < nmodule_list; ++i)
    {
      struct module *runp;

      for (runp = module_list[i]; runp != NULL; runp = runp->next)
	if (strcmp (runp->fromname, "INTERNAL") == 0)
	  {
	    idx = name_to_module_idx (runp->toname, 1);
	    name_info[idx].from_internal = runp;
	    assert (name_info[idx].canonical_name == NULL
		    || strcmp (name_info[idx].canonical_name,
			       runp->toname) == 0);
	    name_info[idx].canonical_name = runp->toname;
	    name_info[idx].canonical_strent = runp->toname_strent;
	  }
	else if (strcmp (runp->toname, "INTERNAL") == 0)
	  {
	    idx = name_to_module_idx (runp->fromname, 1);
	    name_info[idx].to_internal = runp;
	    assert (name_info[idx].canonical_name == NULL
		    || strcmp (name_info[idx].canonical_name,
			       runp->fromname) == 0);
	    name_info[idx].canonical_name = runp->fromname;
	    name_info[idx].canonical_strent = runp->fromname_strent;
	  }
	else
	  {
	    /* This is a transformation not to or from the INTERNAL
	       encoding.  */
	    int from_idx = name_to_module_idx (runp->fromname, 1);
	    int to_idx = name_to_module_idx (runp->toname, 1);
	    struct other_conv_list *newp;

	    newp = (struct other_conv_list *)
	      xmalloc (sizeof (struct other_conv_list));
	    newp->other_conv.module_idx = to_idx;
	    newp->other_conv.module = runp;
	    newp->other_conv.next = NULL; /* XXX Allow multiple module sequence */
	    newp->dest_idx = to_idx;
	    newp->next = name_info[from_idx].other_conv_list;
	    name_info[from_idx].other_conv_list = newp;
	    assert (name_info[from_idx].canonical_name == NULL
		    || strcmp (name_info[from_idx].canonical_name,
			       runp->fromname) == 0);
	    name_info[from_idx].canonical_name = runp->fromname;
	    name_info[from_idx].canonical_strent = runp->fromname_strent;

	    ++nextra_modules;
	  }
    }

  /* Now add the module index information for all the aliases.  */
  for (i = 0; i < nalias_list; ++i)
    {
      struct name fake_name = { .name = alias_list[i]->toname };
      struct name **tonamep;

      tonamep = (struct name **) tfind (&fake_name, &names, name_compare);
      if (tonamep != NULL)
	{
	  struct name *newp = new_name (alias_list[i]->fromname,
					alias_list[i]->froment);
	  newp->module_idx = (*tonamep)->module_idx;
	  tsearch (newp, &names, name_compare);
	}
    }
}


static int
is_prime (unsigned long int candidate)
{
  /* No even number and none less than 10 will be passed here.  */
  unsigned long int divn = 3;
  unsigned long int sq = divn * divn;

  while (sq < candidate && candidate % divn != 0)
    {
      ++divn;
      sq += 4 * divn;
      ++divn;
    }

  return candidate % divn != 0;
}


static uint32_t
next_prime (uint32_t seed)
{
  /* Make it definitely odd.  */
  seed |= 1;

  while (!is_prime (seed))
    seed += 2;

  return seed;
}


/* Format of the output file.

   Offset   Length       Description
   0000     4            Magic header bytes
   0004     2            Offset of string table (stoff)
   0006     2            Offset of name hashing table (hoff)
   0008     2            Hashing table size (hsize)
   000A     2            Offset of module table (moff)
   000C     2            Offset of other conversion module table (ooff)

   stoff    ???          String table

   hoff     8*hsize      Array of tuples
			    string table offset
			    module index

   moff     ???          Array of tuples
			    canonical name offset
			    from-internal module dir name offset
			    from-internal module name off
			    to-internal module dir name offset
			    to-internal module name offset
			    offset into other conversion table

   ooff     ???          One or more of
			    number of steps/modules
			    one or more of tuple
			      canonical name offset for output
			      module dir name offset
			      module name offset
			 (following last entry with step count 0)
*/

static struct hash_entry *hash_table;
static size_t hash_size;

/* Function to insert the names.  */
static void name_insert (const void *nodep, VISIT value, int level)
{
  struct name *name;
  unsigned int idx;
  unsigned int hval2;

  if (value != leaf && value != postorder)
    return;

  name = *(struct name **) nodep;
  idx = name->hashval % hash_size;
  hval2 = 1 + name->hashval % (hash_size - 2);

  while (hash_table[idx].string_offset != 0)
    if ((idx += hval2) >= hash_size)
      idx -= hash_size;

  hash_table[idx].string_offset = strtaboffset (name->strent);

  assert (name->module_idx != -1);
  hash_table[idx].module_idx = name->module_idx;
}

static int
write_output (void)
{
  int fd;
  char *string_table;
  size_t string_table_size;
  struct gconvcache_header header;
  struct module_entry *module_table;
  char *extra_table;
  char *cur_extra_table;
  size_t n;
  int idx;
  struct iovec iov[6];
  static const gidx_t null_word;
  size_t total;
  char finalname[prefix_len + sizeof GCONV_MODULES_CACHE];
  char tmpfname[(output_file == NULL ? sizeof finalname : output_file_len + 1)
		+ strlen (".XXXXXX")];

  /* Open the output file.  */
  if (output_file == NULL)
    {
      assert (GCONV_MODULES_CACHE[0] == '/');
      strcpy (stpcpy (mempcpy (tmpfname, prefix, prefix_len),
		      GCONV_MODULES_CACHE),
	      ".XXXXXX");
      strcpy (mempcpy (finalname, prefix, prefix_len), GCONV_MODULES_CACHE);
    }
  else
    strcpy (mempcpy (tmpfname, output_file, output_file_len), ".XXXXXX");
  fd = mkstemp (tmpfname);
  if (fd == -1)
    return 1;

  /* Create the string table.  */
  string_table = strtabfinalize (strtab, &string_table_size);

  /* Create the hashing table.  We know how many strings we have.
     Creating a perfect hash table is not reasonable here.  Therefore
     we use open hashing and a table size which is the next prime 40%
     larger than the number of strings.  */
  hash_size = next_prime (nnames * 1.4);
  hash_table = (struct hash_entry *) xcalloc (hash_size,
					      sizeof (struct hash_entry));
  /* Fill the hash table.  */
  twalk (names, name_insert);

  /* Create the section for the module list.  */
  module_table = (struct module_entry *) xcalloc (sizeof (struct module_entry),
						  nname_info);

  /* Allocate memory for the non-INTERNAL conversions.  The allocated
     memory can be more than is actually needed.  */
  extra_table = (char *) xcalloc (sizeof (struct extra_entry)
				  + sizeof (gidx_t)
				  + sizeof (struct extra_entry_module),
				  nextra_modules);
  cur_extra_table = extra_table;

  /* Fill in the module information.  */
  for (n = 0; n < nname_info; ++n)
    {
      module_table[n].canonname_offset =
	strtaboffset (name_info[n].canonical_strent);

      if (name_info[n].from_internal == NULL)
	{
	  module_table[n].fromdir_offset = 0;
	  module_table[n].fromname_offset = 0;
	}
      else
	{
	  module_table[n].fromdir_offset =
	    strtaboffset (name_info[n].from_internal->directory_strent);
	  module_table[n].fromname_offset =
	    strtaboffset (name_info[n].from_internal->filename_strent);
	}

      if (name_info[n].to_internal == NULL)
	{
	  module_table[n].todir_offset = 0;
	  module_table[n].toname_offset = 0;
	}
      else
	{
	  module_table[n].todir_offset =
	    strtaboffset (name_info[n].to_internal->directory_strent);
	  module_table[n].toname_offset =
	    strtaboffset (name_info[n].to_internal->filename_strent);
	}

      if (name_info[n].other_conv_list != NULL)
	{
	  struct other_conv_list *other = name_info[n].other_conv_list;

	  /* Store the reference.  We add 1 to distinguish the entry
	     at offset zero from the case where no extra modules are
	     available.  The file reader has to account for the
	     offset.  */
	  module_table[n].extra_offset = 1 + cur_extra_table - extra_table;

	  do
	    {
	      struct other_conv *runp;
	      struct extra_entry *extra;

	      /* Allocate new entry.  */
	      extra = (struct extra_entry *) cur_extra_table;
	      cur_extra_table += sizeof (struct extra_entry);
	      extra->module_cnt = 0;

	      runp = &other->other_conv;
	      do
		{
		  cur_extra_table += sizeof (struct extra_entry_module);
		  extra->module[extra->module_cnt].outname_offset =
		    runp->next == NULL
		    ? other->dest_idx : runp->next->module_idx;
		  extra->module[extra->module_cnt].dir_offset =
		    strtaboffset (runp->module->directory_strent);
		  extra->module[extra->module_cnt].name_offset =
		    strtaboffset (runp->module->filename_strent);
		  ++extra->module_cnt;

		  runp = runp->next;
		}
	      while (runp != NULL);

	      other = other->next;
	    }
	  while (other != NULL);

	  /* Final module_cnt is zero.  */
	  *((gidx_t *) cur_extra_table) = 0;
	  cur_extra_table += sizeof (gidx_t);
	}
    }

  /* Clear padding.  */
  memset (&header, 0, sizeof (struct gconvcache_header));

  header.magic = GCONVCACHE_MAGIC;

  iov[0].iov_base = &header;
  iov[0].iov_len = sizeof (struct gconvcache_header);
  total = iov[0].iov_len;

  header.string_offset = total;
  iov[1].iov_base = string_table;
  iov[1].iov_len = string_table_size;
  total += iov[1].iov_len;

  idx = 2;
  if ((string_table_size & (sizeof (gidx_t) - 1)) != 0)
    {
      iov[2].iov_base = (void *) &null_word;
      iov[2].iov_len = (sizeof (gidx_t)
			- (string_table_size & (sizeof (gidx_t) - 1)));
      total += iov[2].iov_len;
      ++idx;
    }

  header.hash_offset = total;
  header.hash_size = hash_size;
  iov[idx].iov_base = hash_table;
  iov[idx].iov_len = hash_size * sizeof (struct hash_entry);
  total += iov[idx].iov_len;
  ++idx;

  header.module_offset = total;
  iov[idx].iov_base = module_table;
  iov[idx].iov_len = nname_info * sizeof (struct module_entry);
  total += iov[idx].iov_len;
  ++idx;

  assert ((size_t) (cur_extra_table - extra_table)
	  <= ((sizeof (struct extra_entry) + sizeof (gidx_t)
	       + sizeof (struct extra_entry_module))
	      * nextra_modules));
  header.otherconv_offset = total;
  iov[idx].iov_base = extra_table;
  iov[idx].iov_len = cur_extra_table - extra_table;
  total += iov[idx].iov_len;
  ++idx;

  if ((size_t) TEMP_FAILURE_RETRY (writev (fd, iov, idx)) != total
      /* The file was created with mode 0600.  Make it world-readable.  */
      || fchmod (fd, 0644) != 0
      /* Rename the file, possibly replacing an old one.  */
      || rename (tmpfname, output_file ?: finalname) != 0)
    {
      int save_errno = errno;
      close (fd);
      unlink (tmpfname);
      error (EXIT_FAILURE, save_errno,
	     gettext ("cannot generate output file"));
    }

  close (fd);

  return 0;
}