aboutsummaryrefslogtreecommitdiff
path: root/gdb/charset.c
blob: 6f413a2bca2cdb660fae06ad4fac27a12a51e062 (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
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
/* Character set conversion support for GDB.

   Copyright (C) 2001-2014 Free Software Foundation, Inc.

   This file is part of GDB.

   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; either version 3 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 "defs.h"
#include "charset.h"
#include "gdbcmd.h"
#include "gdb_assert.h"
#include "gdb_obstack.h"
#include "gdb_wait.h"
#include "charset-list.h"
#include "vec.h"
#include "environ.h"
#include "arch-utils.h"
#include "gdb_vecs.h"

#include <stddef.h>
#include <string.h>
#include <ctype.h>

#ifdef USE_WIN32API
#include <windows.h>
#endif

/* How GDB's character set support works

   GDB has three global settings:

   - The `current host character set' is the character set GDB should
     use in talking to the user, and which (hopefully) the user's
     terminal knows how to display properly.  Most users should not
     change this.

   - The `current target character set' is the character set the
     program being debugged uses.

   - The `current target wide character set' is the wide character set
     the program being debugged uses, that is, the encoding used for
     wchar_t.

   There are commands to set each of these, and mechanisms for
   choosing reasonable default values.  GDB has a global list of
   character sets that it can use as its host or target character
   sets.

   The header file `charset.h' declares various functions that
   different pieces of GDB need to perform tasks like:

   - printing target strings and characters to the user's terminal
     (mostly target->host conversions),

   - building target-appropriate representations of strings and
     characters the user enters in expressions (mostly host->target
     conversions),

     and so on.
     
   To avoid excessive code duplication and maintenance efforts,
   GDB simply requires a capable iconv function.  Users on platforms
   without a suitable iconv can use the GNU iconv library.  */


#ifdef PHONY_ICONV

/* Provide a phony iconv that does as little as possible.  Also,
   arrange for there to be a single available character set.  */

#undef GDB_DEFAULT_HOST_CHARSET
#define GDB_DEFAULT_HOST_CHARSET "ISO-8859-1"
#define GDB_DEFAULT_TARGET_CHARSET "ISO-8859-1"
#define GDB_DEFAULT_TARGET_WIDE_CHARSET "ISO-8859-1"
#undef DEFAULT_CHARSET_NAMES
#define DEFAULT_CHARSET_NAMES GDB_DEFAULT_HOST_CHARSET ,

#undef iconv_t
#define iconv_t int
#undef iconv_open
#define iconv_open phony_iconv_open
#undef iconv
#define iconv phony_iconv
#undef iconv_close
#define iconv_close phony_iconv_close

#undef ICONV_CONST
#define ICONV_CONST const

/* Some systems don't have EILSEQ, so we define it here, but not as
   EINVAL, because callers of `iconv' want to distinguish EINVAL and
   EILSEQ.  This is what iconv.h from libiconv does as well.  Note
   that wchar.h may also define EILSEQ, so this needs to be after we
   include wchar.h, which happens in defs.h through gdb_wchar.h.  */
#ifndef EILSEQ
#define EILSEQ ENOENT
#endif

static iconv_t
phony_iconv_open (const char *to, const char *from)
{
  /* We allow conversions from UTF-32BE, wchar_t, and the host charset.
     We allow conversions to wchar_t and the host charset.  */
  if (strcmp (from, "UTF-32BE") && strcmp (from, "wchar_t")
      && strcmp (from, GDB_DEFAULT_HOST_CHARSET))
    return -1;
  if (strcmp (to, "wchar_t") && strcmp (to, GDB_DEFAULT_HOST_CHARSET))
    return -1;

  /* Return 1 if we are converting from UTF-32BE, 0 otherwise.  This is
     used as a flag in calls to iconv.  */
  return !strcmp (from, "UTF-32BE");
}

static int
phony_iconv_close (iconv_t arg)
{
  return 0;
}

static size_t
phony_iconv (iconv_t utf_flag, const char **inbuf, size_t *inbytesleft,
	     char **outbuf, size_t *outbytesleft)
{
  if (utf_flag)
    {
      while (*inbytesleft >= 4)
	{
	  size_t j;
	  unsigned long c = 0;

	  for (j = 0; j < 4; ++j)
	    {
	      c <<= 8;
	      c += (*inbuf)[j] & 0xff;
	    }

	  if (c >= 256)
	    {
	      errno = EILSEQ;
	      return -1;
	    }
	  **outbuf = c & 0xff;
	  ++*outbuf;
	  --*outbytesleft;

	  ++*inbuf;
	  *inbytesleft -= 4;
	}
      if (*inbytesleft < 4)
	{
	  errno = EINVAL;
	  return -1;
	}
    }
  else
    {
      /* In all other cases we simply copy input bytes to the
	 output.  */
      size_t amt = *inbytesleft;

      if (amt > *outbytesleft)
	amt = *outbytesleft;
      memcpy (*outbuf, *inbuf, amt);
      *inbuf += amt;
      *outbuf += amt;
      *inbytesleft -= amt;
      *outbytesleft -= amt;
    }

  if (*inbytesleft)
    {
      errno = E2BIG;
      return -1;
    }

  /* The number of non-reversible conversions -- but they were all
     reversible.  */
  return 0;
}

#endif



/* The global lists of character sets and translations.  */


#ifndef GDB_DEFAULT_TARGET_CHARSET
#define GDB_DEFAULT_TARGET_CHARSET "ISO-8859-1"
#endif

#ifndef GDB_DEFAULT_TARGET_WIDE_CHARSET
#define GDB_DEFAULT_TARGET_WIDE_CHARSET "UTF-32"
#endif

static const char *auto_host_charset_name = GDB_DEFAULT_HOST_CHARSET;
static const char *host_charset_name = "auto";
static void
show_host_charset_name (struct ui_file *file, int from_tty,
			struct cmd_list_element *c,
			const char *value)
{
  if (!strcmp (value, "auto"))
    fprintf_filtered (file,
		      _("The host character set is \"auto; currently %s\".\n"),
		      auto_host_charset_name);
  else
    fprintf_filtered (file, _("The host character set is \"%s\".\n"), value);
}

static const char *target_charset_name = "auto";
static void
show_target_charset_name (struct ui_file *file, int from_tty,
			  struct cmd_list_element *c, const char *value)
{
  if (!strcmp (value, "auto"))
    fprintf_filtered (file,
		      _("The target character set is \"auto; "
		        "currently %s\".\n"),
		      gdbarch_auto_charset (get_current_arch ()));
  else
    fprintf_filtered (file, _("The target character set is \"%s\".\n"),
		      value);
}

static const char *target_wide_charset_name = "auto";
static void
show_target_wide_charset_name (struct ui_file *file, 
			       int from_tty,
			       struct cmd_list_element *c, 
			       const char *value)
{
  if (!strcmp (value, "auto"))
    fprintf_filtered (file,
		      _("The target wide character set is \"auto; "
		        "currently %s\".\n"),
		      gdbarch_auto_wide_charset (get_current_arch ()));
  else
    fprintf_filtered (file, _("The target wide character set is \"%s\".\n"),
		      value);
}

static const char *default_charset_names[] =
{
  DEFAULT_CHARSET_NAMES
  0
};

static const char **charset_enum;


/* If the target wide character set has big- or little-endian
   variants, these are the corresponding names.  */
static const char *target_wide_charset_be_name;
static const char *target_wide_charset_le_name;

/* The architecture for which the BE- and LE-names are valid.  */
static struct gdbarch *be_le_arch;

/* A helper function which sets the target wide big- and little-endian
   character set names, if possible.  */

static void
set_be_le_names (struct gdbarch *gdbarch)
{
  int i, len;
  const char *target_wide;

  if (be_le_arch == gdbarch)
    return;
  be_le_arch = gdbarch;

  target_wide_charset_le_name = NULL;
  target_wide_charset_be_name = NULL;

  target_wide = target_wide_charset_name;
  if (!strcmp (target_wide, "auto"))
    target_wide = gdbarch_auto_wide_charset (gdbarch);

  len = strlen (target_wide);
  for (i = 0; charset_enum[i]; ++i)
    {
      if (strncmp (target_wide, charset_enum[i], len))
	continue;
      if ((charset_enum[i][len] == 'B'
	   || charset_enum[i][len] == 'L')
	  && charset_enum[i][len + 1] == 'E'
	  && charset_enum[i][len + 2] == '\0')
	{
	  if (charset_enum[i][len] == 'B')
	    target_wide_charset_be_name = charset_enum[i];
	  else
	    target_wide_charset_le_name = charset_enum[i];
	}
    }
}

/* 'Set charset', 'set host-charset', 'set target-charset', 'set
   target-wide-charset', 'set charset' sfunc's.  */

static void
validate (struct gdbarch *gdbarch)
{
  iconv_t desc;
  const char *host_cset = host_charset ();
  const char *target_cset = target_charset (gdbarch);
  const char *target_wide_cset = target_wide_charset_name;

  if (!strcmp (target_wide_cset, "auto"))
    target_wide_cset = gdbarch_auto_wide_charset (gdbarch);

  desc = iconv_open (target_wide_cset, host_cset);
  if (desc == (iconv_t) -1)
    error (_("Cannot convert between character sets `%s' and `%s'"),
	   target_wide_cset, host_cset);
  iconv_close (desc);

  desc = iconv_open (target_cset, host_cset);
  if (desc == (iconv_t) -1)
    error (_("Cannot convert between character sets `%s' and `%s'"),
	   target_cset, host_cset);
  iconv_close (desc);

  /* Clear the cache.  */
  be_le_arch = NULL;
}

/* This is the sfunc for the 'set charset' command.  */
static void
set_charset_sfunc (char *charset, int from_tty, 
		   struct cmd_list_element *c)
{
  /* CAREFUL: set the target charset here as well.  */
  target_charset_name = host_charset_name;
  validate (get_current_arch ());
}

/* 'set host-charset' command sfunc.  We need a wrapper here because
   the function needs to have a specific signature.  */
static void
set_host_charset_sfunc (char *charset, int from_tty,
			struct cmd_list_element *c)
{
  validate (get_current_arch ());
}

/* Wrapper for the 'set target-charset' command.  */
static void
set_target_charset_sfunc (char *charset, int from_tty,
			  struct cmd_list_element *c)
{
  validate (get_current_arch ());
}

/* Wrapper for the 'set target-wide-charset' command.  */
static void
set_target_wide_charset_sfunc (char *charset, int from_tty,
			       struct cmd_list_element *c)
{
  validate (get_current_arch ());
}

/* sfunc for the 'show charset' command.  */
static void
show_charset (struct ui_file *file, int from_tty, 
	      struct cmd_list_element *c,
	      const char *name)
{
  show_host_charset_name (file, from_tty, c, host_charset_name);
  show_target_charset_name (file, from_tty, c, target_charset_name);
  show_target_wide_charset_name (file, from_tty, c, 
				 target_wide_charset_name);
}


/* Accessor functions.  */

const char *
host_charset (void)
{
  if (!strcmp (host_charset_name, "auto"))
    return auto_host_charset_name;
  return host_charset_name;
}

const char *
target_charset (struct gdbarch *gdbarch)
{
  if (!strcmp (target_charset_name, "auto"))
    return gdbarch_auto_charset (gdbarch);
  return target_charset_name;
}

const char *
target_wide_charset (struct gdbarch *gdbarch)
{
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);

  set_be_le_names (gdbarch);
  if (byte_order == BFD_ENDIAN_BIG)
    {
      if (target_wide_charset_be_name)
	return target_wide_charset_be_name;
    }
  else
    {
      if (target_wide_charset_le_name)
	return target_wide_charset_le_name;
    }

  if (!strcmp (target_wide_charset_name, "auto"))
    return gdbarch_auto_wide_charset (gdbarch);

  return target_wide_charset_name;
}


/* Host character set management.  For the time being, we assume that
   the host character set is some superset of ASCII.  */

char
host_letter_to_control_character (char c)
{
  if (c == '?')
    return 0177;
  return c & 0237;
}

/* Convert a host character, C, to its hex value.  C must already have
   been validated using isxdigit.  */

int
host_hex_value (char c)
{
  if (isdigit (c))
    return c - '0';
  if (c >= 'a' && c <= 'f')
    return 10 + c - 'a';
  gdb_assert (c >= 'A' && c <= 'F');
  return 10 + c - 'A';
}


/* Public character management functions.  */

/* A cleanup function which is run to close an iconv descriptor.  */

static void
cleanup_iconv (void *p)
{
  iconv_t *descp = p;
  iconv_close (*descp);
}

void
convert_between_encodings (const char *from, const char *to,
			   const gdb_byte *bytes, unsigned int num_bytes,
			   int width, struct obstack *output,
			   enum transliterations translit)
{
  iconv_t desc;
  struct cleanup *cleanups;
  size_t inleft;
  ICONV_CONST char *inp;
  unsigned int space_request;

  /* Often, the host and target charsets will be the same.  */
  if (!strcmp (from, to))
    {
      obstack_grow (output, bytes, num_bytes);
      return;
    }

  desc = iconv_open (to, from);
  if (desc == (iconv_t) -1)
    perror_with_name (_("Converting character sets"));
  cleanups = make_cleanup (cleanup_iconv, &desc);

  inleft = num_bytes;
  inp = (ICONV_CONST char *) bytes;

  space_request = num_bytes;

  while (inleft > 0)
    {
      char *outp;
      size_t outleft, r;
      int old_size;

      old_size = obstack_object_size (output);
      obstack_blank (output, space_request);

      outp = obstack_base (output) + old_size;
      outleft = space_request;

      r = iconv (desc, &inp, &inleft, &outp, &outleft);

      /* Now make sure that the object on the obstack only includes
	 bytes we have converted.  */
      obstack_blank (output, - (int) outleft);

      if (r == (size_t) -1)
	{
	  switch (errno)
	    {
	    case EILSEQ:
	      {
		int i;

		/* Invalid input sequence.  */
		if (translit == translit_none)
		  error (_("Could not convert character "
			   "to `%s' character set"), to);

		/* We emit escape sequence for the bytes, skip them,
		   and try again.  */
		for (i = 0; i < width; ++i)
		  {
		    char octal[5];

		    xsnprintf (octal, sizeof (octal), "\\%.3o", *inp & 0xff);
		    obstack_grow_str (output, octal);

		    ++inp;
		    --inleft;
		  }
	      }
	      break;

	    case E2BIG:
	      /* We ran out of space in the output buffer.  Make it
		 bigger next time around.  */
	      space_request *= 2;
	      break;

	    case EINVAL:
	      /* Incomplete input sequence.  FIXME: ought to report this
		 to the caller somehow.  */
	      inleft = 0;
	      break;

	    default:
	      perror_with_name (_("Internal error while "
				  "converting character sets"));
	    }
	}
    }

  do_cleanups (cleanups);
}



/* An iterator that returns host wchar_t's from a target string.  */
struct wchar_iterator
{
  /* The underlying iconv descriptor.  */
  iconv_t desc;

  /* The input string.  This is updated as convert characters.  */
  const gdb_byte *input;
  /* The number of bytes remaining in the input.  */
  size_t bytes;

  /* The width of an input character.  */
  size_t width;

  /* The output buffer and its size.  */
  gdb_wchar_t *out;
  size_t out_size;
};

/* Create a new iterator.  */
struct wchar_iterator *
make_wchar_iterator (const gdb_byte *input, size_t bytes, 
		     const char *charset, size_t width)
{
  struct wchar_iterator *result;
  iconv_t desc;

  desc = iconv_open (INTERMEDIATE_ENCODING, charset);
  if (desc == (iconv_t) -1)
    perror_with_name (_("Converting character sets"));

  result = XNEW (struct wchar_iterator);
  result->desc = desc;
  result->input = input;
  result->bytes = bytes;
  result->width = width;

  result->out = XNEW (gdb_wchar_t);
  result->out_size = 1;

  return result;
}

static void
do_cleanup_iterator (void *p)
{
  struct wchar_iterator *iter = p;

  iconv_close (iter->desc);
  xfree (iter->out);
  xfree (iter);
}

struct cleanup *
make_cleanup_wchar_iterator (struct wchar_iterator *iter)
{
  return make_cleanup (do_cleanup_iterator, iter);
}

int
wchar_iterate (struct wchar_iterator *iter,
	       enum wchar_iterate_result *out_result,
	       gdb_wchar_t **out_chars,
	       const gdb_byte **ptr,
	       size_t *len)
{
  size_t out_request;

  /* Try to convert some characters.  At first we try to convert just
     a single character.  The reason for this is that iconv does not
     necessarily update its outgoing arguments when it encounters an
     invalid input sequence -- but we want to reliably report this to
     our caller so it can emit an escape sequence.  */
  out_request = 1;
  while (iter->bytes > 0)
    {
      ICONV_CONST char *inptr = (ICONV_CONST char *) iter->input;
      char *outptr = (char *) &iter->out[0];
      const gdb_byte *orig_inptr = iter->input;
      size_t orig_in = iter->bytes;
      size_t out_avail = out_request * sizeof (gdb_wchar_t);
      size_t num;
      size_t r = iconv (iter->desc, &inptr, &iter->bytes, &outptr, &out_avail);

      iter->input = (gdb_byte *) inptr;

      if (r == (size_t) -1)
	{
	  switch (errno)
	    {
	    case EILSEQ:
	      /* Invalid input sequence.  We still might have
		 converted a character; if so, return it.  */
	      if (out_avail < out_request * sizeof (gdb_wchar_t))
		break;
	      
	      /* Otherwise skip the first invalid character, and let
		 the caller know about it.  */
	      *out_result = wchar_iterate_invalid;
	      *ptr = iter->input;
	      *len = iter->width;
	      iter->input += iter->width;
	      iter->bytes -= iter->width;
	      return 0;

	    case E2BIG:
	      /* We ran out of space.  We still might have converted a
		 character; if so, return it.  Otherwise, grow the
		 buffer and try again.  */
	      if (out_avail < out_request * sizeof (gdb_wchar_t))
		break;

	      ++out_request;
	      if (out_request > iter->out_size)
		{
		  iter->out_size = out_request;
		  iter->out = xrealloc (iter->out,
					out_request * sizeof (gdb_wchar_t));
		}
	      continue;

	    case EINVAL:
	      /* Incomplete input sequence.  Let the caller know, and
		 arrange for future calls to see EOF.  */
	      *out_result = wchar_iterate_incomplete;
	      *ptr = iter->input;
	      *len = iter->bytes;
	      iter->bytes = 0;
	      return 0;

	    default:
	      perror_with_name (_("Internal error while "
				  "converting character sets"));
	    }
	}

      /* We converted something.  */
      num = out_request - out_avail / sizeof (gdb_wchar_t);
      *out_result = wchar_iterate_ok;
      *out_chars = iter->out;
      *ptr = orig_inptr;
      *len = orig_in - iter->bytes;
      return num;
    }

  /* Really done.  */
  *out_result = wchar_iterate_eof;
  return -1;
}


/* The charset.c module initialization function.  */

extern initialize_file_ftype _initialize_charset; /* -Wmissing-prototype */

static VEC (char_ptr) *charsets;

#ifdef PHONY_ICONV

static void
find_charset_names (void)
{
  VEC_safe_push (char_ptr, charsets, GDB_DEFAULT_HOST_CHARSET);
  VEC_safe_push (char_ptr, charsets, NULL);
}

#else /* PHONY_ICONV */

/* Sometimes, libiconv redefines iconvlist as libiconvlist -- but
   provides different symbols in the static and dynamic libraries.
   So, configure may see libiconvlist but not iconvlist.  But, calling
   iconvlist is the right thing to do and will work.  Hence we do a
   check here but unconditionally call iconvlist below.  */
#if defined (HAVE_ICONVLIST) || defined (HAVE_LIBICONVLIST)

/* A helper function that adds some character sets to the vector of
   all character sets.  This is a callback function for iconvlist.  */

static int
add_one (unsigned int count, const char *const *names, void *data)
{
  unsigned int i;

  for (i = 0; i < count; ++i)
    VEC_safe_push (char_ptr, charsets, xstrdup (names[i]));

  return 0;
}

static void
find_charset_names (void)
{
  iconvlist (add_one, NULL);
  VEC_safe_push (char_ptr, charsets, NULL);
}

#else

/* Return non-zero if LINE (output from iconv) should be ignored.
   Older iconv programs (e.g. 2.2.2) include the human readable
   introduction even when stdout is not a tty.  Newer versions omit
   the intro if stdout is not a tty.  */

static int
ignore_line_p (const char *line)
{
  /* This table is used to filter the output.  If this text appears
     anywhere in the line, it is ignored (strstr is used).  */
  static const char * const ignore_lines[] =
    {
      "The following",
      "not necessarily",
      "the FROM and TO",
      "listed with several",
      NULL
    };
  int i;

  for (i = 0; ignore_lines[i] != NULL; ++i)
    {
      if (strstr (line, ignore_lines[i]) != NULL)
	return 1;
    }

  return 0;
}

static void
find_charset_names (void)
{
  struct pex_obj *child;
  char *args[3];
  int err, status;
  int fail = 1;
  int flags;
  struct gdb_environ *iconv_env;
  char *iconv_program;

  /* Older iconvs, e.g. 2.2.2, don't omit the intro text if stdout is
     not a tty.  We need to recognize it and ignore it.  This text is
     subject to translation, so force LANGUAGE=C.  */
  iconv_env = make_environ ();
  init_environ (iconv_env);
  set_in_environ (iconv_env, "LANGUAGE", "C");
  set_in_environ (iconv_env, "LC_ALL", "C");

  child = pex_init (PEX_USE_PIPES, "iconv", NULL);

#ifdef ICONV_BIN
  {
    char *iconv_dir = relocate_gdb_directory (ICONV_BIN,
					      ICONV_BIN_RELOCATABLE);
    iconv_program = concat (iconv_dir, SLASH_STRING, "iconv", NULL);
    xfree (iconv_dir);
  }
#else
  iconv_program = xstrdup ("iconv");
#endif
  args[0] = iconv_program;
  args[1] = "-l";
  args[2] = NULL;
  flags = PEX_STDERR_TO_STDOUT;
#ifndef ICONV_BIN
  flags |= PEX_SEARCH;
#endif
  /* Note that we simply ignore errors here.  */
  if (!pex_run_in_environment (child, flags,
			       args[0], args, environ_vector (iconv_env),
			       NULL, NULL, &err))
    {
      FILE *in = pex_read_output (child, 0);

      /* POSIX says that iconv -l uses an unspecified format.  We
	 parse the glibc and libiconv formats; feel free to add others
	 as needed.  */

      while (in != NULL && !feof (in))
	{
	  /* The size of buf is chosen arbitrarily.  */
	  char buf[1024];
	  char *start, *r;
	  int len;

	  r = fgets (buf, sizeof (buf), in);
	  if (!r)
	    break;
	  len = strlen (r);
	  if (len <= 3)
	    continue;
	  if (ignore_line_p (r))
	    continue;

	  /* Strip off the newline.  */
	  --len;
	  /* Strip off one or two '/'s.  glibc will print lines like
	     "8859_7//", but also "10646-1:1993/UCS4/".  */
	  if (buf[len - 1] == '/')
	    --len;
	  if (buf[len - 1] == '/')
	    --len;
	  buf[len] = '\0';

	  /* libiconv will print multiple entries per line, separated
	     by spaces.  Older iconvs will print multiple entries per
	     line, indented by two spaces, and separated by ", "
	     (i.e. the human readable form).  */
	  start = buf;
	  while (1)
	    {
	      int keep_going;
	      char *p;

	      /* Skip leading blanks.  */
	      for (p = start; *p && *p == ' '; ++p)
		;
	      start = p;
	      /* Find the next space, comma, or end-of-line.  */
	      for ( ; *p && *p != ' ' && *p != ','; ++p)
		;
	      /* Ignore an empty result.  */
	      if (p == start)
		break;
	      keep_going = *p;
	      *p = '\0';
	      VEC_safe_push (char_ptr, charsets, xstrdup (start));
	      if (!keep_going)
		break;
	      /* Skip any extra spaces.  */
	      for (start = p + 1; *start && *start == ' '; ++start)
		;
	    }
	}

      if (pex_get_status (child, 1, &status)
	  && WIFEXITED (status) && !WEXITSTATUS (status))
	fail = 0;

    }

  xfree (iconv_program);
  pex_free (child);
  free_environ (iconv_env);

  if (fail)
    {
      /* Some error occurred, so drop the vector.  */
      free_char_ptr_vec (charsets);
      charsets = NULL;
    }
  else
    VEC_safe_push (char_ptr, charsets, NULL);
}

#endif /* HAVE_ICONVLIST || HAVE_LIBICONVLIST */
#endif /* PHONY_ICONV */

/* The "auto" target charset used by default_auto_charset.  */
static const char *auto_target_charset_name = GDB_DEFAULT_TARGET_CHARSET;

const char *
default_auto_charset (void)
{
  return auto_target_charset_name;
}

const char *
default_auto_wide_charset (void)
{
  return GDB_DEFAULT_TARGET_WIDE_CHARSET;
}


#ifdef USE_INTERMEDIATE_ENCODING_FUNCTION
/* Macro used for UTF or UCS endianness suffix.  */
#if WORDS_BIGENDIAN
#define ENDIAN_SUFFIX "BE"
#else
#define ENDIAN_SUFFIX "LE"
#endif

/* The code below serves to generate a compile time error if
   gdb_wchar_t type is not of size 2 nor 4, despite the fact that
   macro __STDC_ISO_10646__ is defined.
   This is better than a gdb_assert call, because GDB cannot handle
   strings correctly if this size is different.  */

extern char your_gdb_wchar_t_is_bogus[(sizeof (gdb_wchar_t) == 2
				       || sizeof (gdb_wchar_t) == 4)
				      ? 1 : -1];

/* intermediate_encoding returns the charset used internally by
   GDB to convert between target and host encodings. As the test above
   compiled, sizeof (gdb_wchar_t) is either 2 or 4 bytes.
   UTF-16/32 is tested first, UCS-2/4 is tested as a second option,
   otherwise an error is generated.  */

const char *
intermediate_encoding (void)
{
  iconv_t desc;
  static const char *stored_result = NULL;
  char *result;

  if (stored_result)
    return stored_result;
  result = xstrprintf ("UTF-%d%s", (int) (sizeof (gdb_wchar_t) * 8),
		       ENDIAN_SUFFIX);
  /* Check that the name is supported by iconv_open.  */
  desc = iconv_open (result, host_charset ());
  if (desc != (iconv_t) -1)
    {
      iconv_close (desc);
      stored_result = result;
      return result;
    }
  /* Not valid, free the allocated memory.  */
  xfree (result);
  /* Second try, with UCS-2 type.  */
  result = xstrprintf ("UCS-%d%s", (int) sizeof (gdb_wchar_t),
		       ENDIAN_SUFFIX);
  /* Check that the name is supported by iconv_open.  */
  desc = iconv_open (result, host_charset ());
  if (desc != (iconv_t) -1)
    {
      iconv_close (desc);
      stored_result = result;
      return result;
    }
  /* Not valid, free the allocated memory.  */
  xfree (result);
  /* No valid charset found, generate error here.  */
  error (_("Unable to find a vaild charset for string conversions"));
}

#endif /* USE_INTERMEDIATE_ENCODING_FUNCTION */

void
_initialize_charset (void)
{
  /* The first element is always "auto".  */
  VEC_safe_push (char_ptr, charsets, xstrdup ("auto"));
  find_charset_names ();

  if (VEC_length (char_ptr, charsets) > 1)
    charset_enum = (const char **) VEC_address (char_ptr, charsets);
  else
    charset_enum = default_charset_names;

#ifndef PHONY_ICONV
#ifdef HAVE_LANGINFO_CODESET
  /* The result of nl_langinfo may be overwritten later.  This may
     leak a little memory, if the user later changes the host charset,
     but that doesn't matter much.  */
  auto_host_charset_name = xstrdup (nl_langinfo (CODESET));
  /* Solaris will return `646' here -- but the Solaris iconv then does
     not accept this.  Darwin (and maybe FreeBSD) may return "" here,
     which GNU libiconv doesn't like (infinite loop).  */
  if (!strcmp (auto_host_charset_name, "646") || !*auto_host_charset_name)
    auto_host_charset_name = "ASCII";
  auto_target_charset_name = auto_host_charset_name;
#elif defined (USE_WIN32API)
  {
    /* "CP" + x<=5 digits + paranoia.  */
    static char w32_host_default_charset[16];

    snprintf (w32_host_default_charset, sizeof w32_host_default_charset,
	      "CP%d", GetACP());
    auto_host_charset_name = w32_host_default_charset;
    auto_target_charset_name = auto_host_charset_name;
  }
#endif
#endif

  add_setshow_enum_cmd ("charset", class_support,
			charset_enum, &host_charset_name, _("\
Set the host and target character sets."), _("\
Show the host and target character sets."), _("\
The `host character set' is the one used by the system GDB is running on.\n\
The `target character set' is the one used by the program being debugged.\n\
You may only use supersets of ASCII for your host character set; GDB does\n\
not support any others.\n\
To see a list of the character sets GDB supports, type `set charset <TAB>'."),
			/* Note that the sfunc below needs to set
			   target_charset_name, because the 'set
			   charset' command sets two variables.  */
			set_charset_sfunc,
			show_charset,
			&setlist, &showlist);

  add_setshow_enum_cmd ("host-charset", class_support,
			charset_enum, &host_charset_name, _("\
Set the host character set."), _("\
Show the host character set."), _("\
The `host character set' is the one used by the system GDB is running on.\n\
You may only use supersets of ASCII for your host character set; GDB does\n\
not support any others.\n\
To see a list of the character sets GDB supports, type `set host-charset <TAB>'."),
			set_host_charset_sfunc,
			show_host_charset_name,
			&setlist, &showlist);

  add_setshow_enum_cmd ("target-charset", class_support,
			charset_enum, &target_charset_name, _("\
Set the target character set."), _("\
Show the target character set."), _("\
The `target character set' is the one used by the program being debugged.\n\
GDB translates characters and strings between the host and target\n\
character sets as needed.\n\
To see a list of the character sets GDB supports, type `set target-charset'<TAB>"),
			set_target_charset_sfunc,
			show_target_charset_name,
			&setlist, &showlist);

  add_setshow_enum_cmd ("target-wide-charset", class_support,
			charset_enum, &target_wide_charset_name,
			_("\
Set the target wide character set."), _("\
Show the target wide character set."), _("\
The `target wide character set' is the one used by the program being debugged.\
\nIn particular it is the encoding used by `wchar_t'.\n\
GDB translates characters and strings between the host and target\n\
character sets as needed.\n\
To see a list of the character sets GDB supports, type\n\
`set target-wide-charset'<TAB>"),
			set_target_wide_charset_sfunc,
			show_target_wide_charset_name,
			&setlist, &showlist);
}