aboutsummaryrefslogtreecommitdiff
path: root/gdb/c-lang.c
blob: 2c075f46f4b262f0a1bffe05b3fb253a7a8c168e (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
1095
1096
1097
/* C language support routines for GDB, the GNU debugger.

   Copyright (C) 1992-2013 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 "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "parser-defs.h"
#include "language.h"
#include "varobj.h"
#include "c-lang.h"
#include "valprint.h"
#include "macroscope.h"
#include "gdb_assert.h"
#include "charset.h"
#include <string.h>
#include "demangle.h"
#include "cp-abi.h"
#include "cp-support.h"
#include "gdb_obstack.h"
#include <ctype.h>
#include "exceptions.h"
#include "gdbcore.h"

extern void _initialize_c_language (void);

/* Given a C string type, STR_TYPE, return the corresponding target
   character set name.  */

static const char *
charset_for_string_type (enum c_string_type str_type,
			 struct gdbarch *gdbarch)
{
  switch (str_type & ~C_CHAR)
    {
    case C_STRING:
      return target_charset (gdbarch);
    case C_WIDE_STRING:
      return target_wide_charset (gdbarch);
    case C_STRING_16:
      /* FIXME: UTF-16 is not always correct.  */
      if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
	return "UTF-16BE";
      else
	return "UTF-16LE";
    case C_STRING_32:
      /* FIXME: UTF-32 is not always correct.  */
      if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
	return "UTF-32BE";
      else
	return "UTF-32LE";
    }
  internal_error (__FILE__, __LINE__, _("unhandled c_string_type"));
}

/* Classify ELTTYPE according to what kind of character it is.  Return
   the enum constant representing the character type.  Also set
   *ENCODING to the name of the character set to use when converting
   characters of this type in target BYTE_ORDER to the host character
   set.  */

static enum c_string_type
classify_type (struct type *elttype, struct gdbarch *gdbarch,
	       const char **encoding)
{
  enum c_string_type result;

  /* We loop because ELTTYPE may be a typedef, and we want to
     successively peel each typedef until we reach a type we
     understand.  We don't use CHECK_TYPEDEF because that will strip
     all typedefs at once -- but in C, wchar_t is itself a typedef, so
     that would do the wrong thing.  */
  while (elttype)
    {
      const char *name = TYPE_NAME (elttype);

      if (TYPE_CODE (elttype) == TYPE_CODE_CHAR || !name)
	{
	  result = C_CHAR;
	  goto done;
	}

      if (!strcmp (name, "wchar_t"))
	{
	  result = C_WIDE_CHAR;
	  goto done;
	}

      if (!strcmp (name, "char16_t"))
	{
	  result = C_CHAR_16;
	  goto done;
	}

      if (!strcmp (name, "char32_t"))
	{
	  result = C_CHAR_32;
	  goto done;
	}

      if (TYPE_CODE (elttype) != TYPE_CODE_TYPEDEF)
	break;

      /* Call for side effects.  */
      check_typedef (elttype);

      if (TYPE_TARGET_TYPE (elttype))
	elttype = TYPE_TARGET_TYPE (elttype);
      else
	{
	  /* Perhaps check_typedef did not update the target type.  In
	     this case, force the lookup again and hope it works out.
	     It never will for C, but it might for C++.  */
	  CHECK_TYPEDEF (elttype);
	}
    }

  /* Punt.  */
  result = C_CHAR;

 done:
  if (encoding)
    *encoding = charset_for_string_type (result, gdbarch);

  return result;
}

/* Print the character C on STREAM as part of the contents of a
   literal string whose delimiter is QUOTER.  Note that that format
   for printing characters and strings is language specific.  */

void
c_emit_char (int c, struct type *type,
	     struct ui_file *stream, int quoter)
{
  const char *encoding;

  classify_type (type, get_type_arch (type), &encoding);
  generic_emit_char (c, type, stream, quoter, encoding);
}

void
c_printchar (int c, struct type *type, struct ui_file *stream)
{
  enum c_string_type str_type;

  str_type = classify_type (type, get_type_arch (type), NULL);
  switch (str_type)
    {
    case C_CHAR:
      break;
    case C_WIDE_CHAR:
      fputc_filtered ('L', stream);
      break;
    case C_CHAR_16:
      fputc_filtered ('u', stream);
      break;
    case C_CHAR_32:
      fputc_filtered ('U', stream);
      break;
    }

  fputc_filtered ('\'', stream);
  LA_EMIT_CHAR (c, type, stream, '\'');
  fputc_filtered ('\'', stream);
}

/* Print the character string STRING, printing at most LENGTH
   characters.  LENGTH is -1 if the string is nul terminated.  Each
   character is WIDTH bytes long.  Printing stops early if the number
   hits print_max; repeat counts are printed as appropriate.  Print
   ellipses at the end if we had to stop before printing LENGTH
   characters, or if FORCE_ELLIPSES.  */

void
c_printstr (struct ui_file *stream, struct type *type, 
	    const gdb_byte *string, unsigned int length, 
	    const char *user_encoding, int force_ellipses,
	    const struct value_print_options *options)
{
  enum c_string_type str_type;
  const char *type_encoding;
  const char *encoding;

  str_type = (classify_type (type, get_type_arch (type), &type_encoding)
	      & ~C_CHAR);
  switch (str_type)
    {
    case C_STRING:
      break;
    case C_WIDE_STRING:
      fputs_filtered ("L", stream);
      break;
    case C_STRING_16:
      fputs_filtered ("u", stream);
      break;
    case C_STRING_32:
      fputs_filtered ("U", stream);
      break;
    }

  encoding = (user_encoding && *user_encoding) ? user_encoding : type_encoding;

  generic_printstr (stream, type, string, length, encoding, force_ellipses,
		    '"', 1, options);
}

/* Obtain a C string from the inferior storing it in a newly allocated
   buffer in BUFFER, which should be freed by the caller.  If the in-
   and out-parameter *LENGTH is specified at -1, the string is read
   until a null character of the appropriate width is found, otherwise
   the string is read to the length of characters specified.  The size
   of a character is determined by the length of the target type of
   the pointer or array.

   If VALUE is an array with a known length, and *LENGTH is -1,
   the function will not read past the end of the array.  However, any
   declared size of the array is ignored if *LENGTH > 0.

   On completion, *LENGTH will be set to the size of the string read in
   characters.  (If a length of -1 is specified, the length returned
   will not include the null character).  CHARSET is always set to the
   target charset.  */

void
c_get_string (struct value *value, gdb_byte **buffer,
	      int *length, struct type **char_type,
	      const char **charset)
{
  int err, width;
  unsigned int fetchlimit;
  struct type *type = check_typedef (value_type (value));
  struct type *element_type = TYPE_TARGET_TYPE (type);
  int req_length = *length;
  enum bfd_endian byte_order
    = gdbarch_byte_order (get_type_arch (type));

  if (element_type == NULL)
    goto error;

  if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
    {
      /* If we know the size of the array, we can use it as a limit on
	 the number of characters to be fetched.  */
      if (TYPE_NFIELDS (type) == 1
	  && TYPE_CODE (TYPE_FIELD_TYPE (type, 0)) == TYPE_CODE_RANGE)
	{
	  LONGEST low_bound, high_bound;

	  get_discrete_bounds (TYPE_FIELD_TYPE (type, 0),
			       &low_bound, &high_bound);
	  fetchlimit = high_bound - low_bound + 1;
	}
      else
	fetchlimit = UINT_MAX;
    }
  else if (TYPE_CODE (type) == TYPE_CODE_PTR)
    fetchlimit = UINT_MAX;
  else
    /* We work only with arrays and pointers.  */
    goto error;

  if (! c_textual_element_type (element_type, 0))
    goto error;
  classify_type (element_type, get_type_arch (element_type), charset);
  width = TYPE_LENGTH (element_type);

  /* If the string lives in GDB's memory instead of the inferior's,
     then we just need to copy it to BUFFER.  Also, since such strings
     are arrays with known size, FETCHLIMIT will hold the size of the
     array.  */
  if ((VALUE_LVAL (value) == not_lval
       || VALUE_LVAL (value) == lval_internalvar)
      && fetchlimit != UINT_MAX)
    {
      int i;
      const gdb_byte *contents = value_contents (value);

      /* If a length is specified, use that.  */
      if (*length >= 0)
	i  = *length;
      else
 	/* Otherwise, look for a null character.  */
 	for (i = 0; i < fetchlimit; i++)
	  if (extract_unsigned_integer (contents + i * width,
					width, byte_order) == 0)
 	    break;
  
      /* I is now either a user-defined length, the number of non-null
 	 characters, or FETCHLIMIT.  */
      *length = i * width;
      *buffer = xmalloc (*length);
      memcpy (*buffer, contents, *length);
      err = 0;
    }
  else
    {
      CORE_ADDR addr = value_as_address (value);

      /* Prior to the fix for PR 16196 read_string would ignore fetchlimit
	 if length > 0.  The old "broken" behaviour is the behaviour we want:
	 The caller may want to fetch 100 bytes from a variable length array
	 implemented using the common idiom of having an array of length 1 at
	 the end of a struct.  In this case we want to ignore the declared
	 size of the array.  However, it's counterintuitive to implement that
	 behaviour in read_string: what does fetchlimit otherwise mean if
	 length > 0.  Therefore we implement the behaviour we want here:
	 If *length > 0, don't specify a fetchlimit.  This preserves the
	 previous behaviour.  We could move this check above where we know
	 whether the array is declared with a fixed size, but we only want
	 to apply this behaviour when calling read_string.  PR 16286.  */
      if (*length > 0)
	fetchlimit = UINT_MAX;

      err = read_string (addr, *length, width, fetchlimit,
			 byte_order, buffer, length);
      if (err)
	{
	  xfree (*buffer);
	  memory_error (err, addr);
	}
    }

  /* If the LENGTH is specified at -1, we want to return the string
     length up to the terminating null character.  If an actual length
     was specified, we want to return the length of exactly what was
     read.  */
  if (req_length == -1)
    /* If the last character is null, subtract it from LENGTH.  */
    if (*length > 0
 	&& extract_unsigned_integer (*buffer + *length - width,
				     width, byte_order) == 0)
      *length -= width;
  
  /* The read_string function will return the number of bytes read.
     If length returned from read_string was > 0, return the number of
     characters read by dividing the number of bytes by width.  */
  if (*length != 0)
     *length = *length / width;

  *char_type = element_type;

  return;

 error:
  {
    char *type_str;

    type_str = type_to_string (type);
    if (type_str)
      {
	make_cleanup (xfree, type_str);
	error (_("Trying to read string with inappropriate type `%s'."),
	       type_str);
      }
    else
      error (_("Trying to read string with inappropriate type."));
  }
}


/* Evaluating C and C++ expressions.  */

/* Convert a UCN.  The digits of the UCN start at P and extend no
   farther than LIMIT.  DEST_CHARSET is the name of the character set
   into which the UCN should be converted.  The results are written to
   OUTPUT.  LENGTH is the maximum length of the UCN, either 4 or 8.
   Returns a pointer to just after the final digit of the UCN.  */

static char *
convert_ucn (char *p, char *limit, const char *dest_charset,
	     struct obstack *output, int length)
{
  unsigned long result = 0;
  gdb_byte data[4];
  int i;

  for (i = 0; i < length && p < limit && isxdigit (*p); ++i, ++p)
    result = (result << 4) + host_hex_value (*p);

  for (i = 3; i >= 0; --i)
    {
      data[i] = result & 0xff;
      result >>= 8;
    }

  convert_between_encodings ("UTF-32BE", dest_charset, data,
			     4, 4, output, translit_none);

  return p;
}

/* Emit a character, VALUE, which was specified numerically, to
   OUTPUT.  TYPE is the target character type.  */

static void
emit_numeric_character (struct type *type, unsigned long value,
			struct obstack *output)
{
  gdb_byte *buffer;

  buffer = alloca (TYPE_LENGTH (type));
  pack_long (buffer, type, value);
  obstack_grow (output, buffer, TYPE_LENGTH (type));
}

/* Convert an octal escape sequence.  TYPE is the target character
   type.  The digits of the escape sequence begin at P and extend no
   farther than LIMIT.  The result is written to OUTPUT.  Returns a
   pointer to just after the final digit of the escape sequence.  */

static char *
convert_octal (struct type *type, char *p, 
	       char *limit, struct obstack *output)
{
  int i;
  unsigned long value = 0;

  for (i = 0;
       i < 3 && p < limit && isdigit (*p) && *p != '8' && *p != '9';
       ++i)
    {
      value = 8 * value + host_hex_value (*p);
      ++p;
    }

  emit_numeric_character (type, value, output);

  return p;
}

/* Convert a hex escape sequence.  TYPE is the target character type.
   The digits of the escape sequence begin at P and extend no farther
   than LIMIT.  The result is written to OUTPUT.  Returns a pointer to
   just after the final digit of the escape sequence.  */

static char *
convert_hex (struct type *type, char *p,
	     char *limit, struct obstack *output)
{
  unsigned long value = 0;

  while (p < limit && isxdigit (*p))
    {
      value = 16 * value + host_hex_value (*p);
      ++p;
    }

  emit_numeric_character (type, value, output);

  return p;
}

#define ADVANCE					\
  do {						\
    ++p;					\
    if (p == limit)				\
      error (_("Malformed escape sequence"));	\
  } while (0)

/* Convert an escape sequence to a target format.  TYPE is the target
   character type to use, and DEST_CHARSET is the name of the target
   character set.  The backslash of the escape sequence is at *P, and
   the escape sequence will not extend past LIMIT.  The results are
   written to OUTPUT.  Returns a pointer to just past the final
   character of the escape sequence.  */

static char *
convert_escape (struct type *type, const char *dest_charset,
		char *p, char *limit, struct obstack *output)
{
  /* Skip the backslash.  */
  ADVANCE;

  switch (*p)
    {
    case '\\':
      obstack_1grow (output, '\\');
      ++p;
      break;

    case 'x':
      ADVANCE;
      if (!isxdigit (*p))
	error (_("\\x used with no following hex digits."));
      p = convert_hex (type, p, limit, output);
      break;

    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
      p = convert_octal (type, p, limit, output);
      break;

    case 'u':
    case 'U':
      {
	int length = *p == 'u' ? 4 : 8;

	ADVANCE;
	if (!isxdigit (*p))
	  error (_("\\u used with no following hex digits"));
	p = convert_ucn (p, limit, dest_charset, output, length);
      }
    }

  return p;
}

/* Given a single string from a (C-specific) OP_STRING list, convert
   it to a target string, handling escape sequences specially.  The
   output is written to OUTPUT.  DATA is the input string, which has
   length LEN.  DEST_CHARSET is the name of the target character set,
   and TYPE is the type of target character to use.  */

static void
parse_one_string (struct obstack *output, char *data, int len,
		  const char *dest_charset, struct type *type)
{
  char *limit;

  limit = data + len;

  while (data < limit)
    {
      char *p = data;

      /* Look for next escape, or the end of the input.  */
      while (p < limit && *p != '\\')
	++p;
      /* If we saw a run of characters, convert them all.  */
      if (p > data)
	convert_between_encodings (host_charset (), dest_charset,
				   (gdb_byte *) data, p - data, 1,
				   output, translit_none);
      /* If we saw an escape, convert it.  */
      if (p < limit)
	p = convert_escape (type, dest_charset, p, limit, output);
      data = p;
    }
}

/* Expression evaluator for the C language family.  Most operations
   are delegated to evaluate_subexp_standard; see that function for a
   description of the arguments.  */

struct value *
evaluate_subexp_c (struct type *expect_type, struct expression *exp,
		   int *pos, enum noside noside)
{
  enum exp_opcode op = exp->elts[*pos].opcode;

  switch (op)
    {
    case OP_STRING:
      {
	int oplen, limit;
	struct type *type;
	struct obstack output;
	struct cleanup *cleanup;
	struct value *result;
	enum c_string_type dest_type;
	const char *dest_charset;
	int satisfy_expected = 0;

	obstack_init (&output);
	cleanup = make_cleanup_obstack_free (&output);

	++*pos;
	oplen = longest_to_int (exp->elts[*pos].longconst);

	++*pos;
	limit = *pos + BYTES_TO_EXP_ELEM (oplen + 1);
	dest_type
	  = (enum c_string_type) longest_to_int (exp->elts[*pos].longconst);
	switch (dest_type & ~C_CHAR)
	  {
	  case C_STRING:
	    type = language_string_char_type (exp->language_defn,
					      exp->gdbarch);
	    break;
	  case C_WIDE_STRING:
	    type = lookup_typename (exp->language_defn, exp->gdbarch,
				    "wchar_t", NULL, 0);
	    break;
	  case C_STRING_16:
	    type = lookup_typename (exp->language_defn, exp->gdbarch,
				    "char16_t", NULL, 0);
	    break;
	  case C_STRING_32:
	    type = lookup_typename (exp->language_defn, exp->gdbarch,
				    "char32_t", NULL, 0);
	    break;
	  default:
	    internal_error (__FILE__, __LINE__, _("unhandled c_string_type"));
	  }

	/* Ensure TYPE_LENGTH is valid for TYPE.  */
	check_typedef (type);

	/* If the caller expects an array of some integral type,
	   satisfy them.  If something odder is expected, rely on the
	   caller to cast.  */
	if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_ARRAY)
	  {
	    struct type *element_type
	      = check_typedef (TYPE_TARGET_TYPE (expect_type));

	    if (TYPE_CODE (element_type) == TYPE_CODE_INT
		|| TYPE_CODE (element_type) == TYPE_CODE_CHAR)
	      {
		type = element_type;
		satisfy_expected = 1;
	      }
	  }

	dest_charset = charset_for_string_type (dest_type, exp->gdbarch);

	++*pos;
	while (*pos < limit)
	  {
	    int len;

	    len = longest_to_int (exp->elts[*pos].longconst);

	    ++*pos;
	    if (noside != EVAL_SKIP)
	      parse_one_string (&output, &exp->elts[*pos].string, len,
				dest_charset, type);
	    *pos += BYTES_TO_EXP_ELEM (len);
	  }

	/* Skip the trailing length and opcode.  */
	*pos += 2;

	if (noside == EVAL_SKIP)
	  {
	    /* Return a dummy value of the appropriate type.  */
	    if (expect_type != NULL)
	      result = allocate_value (expect_type);
	    else if ((dest_type & C_CHAR) != 0)
	      result = allocate_value (type);
	    else
	      result = value_cstring ("", 0, type);
	    do_cleanups (cleanup);
	    return result;
	  }

	if ((dest_type & C_CHAR) != 0)
	  {
	    LONGEST value;

	    if (obstack_object_size (&output) != TYPE_LENGTH (type))
	      error (_("Could not convert character "
		       "constant to target character set"));
	    value = unpack_long (type, (gdb_byte *) obstack_base (&output));
	    result = value_from_longest (type, value);
	  }
	else
	  {
	    int i;

	    /* Write the terminating character.  */
	    for (i = 0; i < TYPE_LENGTH (type); ++i)
	      obstack_1grow (&output, 0);

	    if (satisfy_expected)
	      {
		LONGEST low_bound, high_bound;
		int element_size = TYPE_LENGTH (type);

		if (get_discrete_bounds (TYPE_INDEX_TYPE (expect_type),
					 &low_bound, &high_bound) < 0)
		  {
		    low_bound = 0;
		    high_bound = (TYPE_LENGTH (expect_type) / element_size) - 1;
		  }
		if (obstack_object_size (&output) / element_size
		    > (high_bound - low_bound + 1))
		  error (_("Too many array elements"));

		result = allocate_value (expect_type);
		memcpy (value_contents_raw (result), obstack_base (&output),
			obstack_object_size (&output));
	      }
	    else
	      result = value_cstring (obstack_base (&output),
				      obstack_object_size (&output),
				      type);
	  }
	do_cleanups (cleanup);
	return result;
      }
      break;

    default:
      break;
    }
  return evaluate_subexp_standard (expect_type, exp, pos, noside);
}



/* Table mapping opcodes into strings for printing operators
   and precedences of the operators.  */

const struct op_print c_op_print_tab[] =
{
  {",", BINOP_COMMA, PREC_COMMA, 0},
  {"=", BINOP_ASSIGN, PREC_ASSIGN, 1},
  {"||", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
  {"&&", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
  {"|", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
  {"^", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
  {"&", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
  {"==", BINOP_EQUAL, PREC_EQUAL, 0},
  {"!=", BINOP_NOTEQUAL, PREC_EQUAL, 0},
  {"<=", BINOP_LEQ, PREC_ORDER, 0},
  {">=", BINOP_GEQ, PREC_ORDER, 0},
  {">", BINOP_GTR, PREC_ORDER, 0},
  {"<", BINOP_LESS, PREC_ORDER, 0},
  {">>", BINOP_RSH, PREC_SHIFT, 0},
  {"<<", BINOP_LSH, PREC_SHIFT, 0},
  {"+", BINOP_ADD, PREC_ADD, 0},
  {"-", BINOP_SUB, PREC_ADD, 0},
  {"*", BINOP_MUL, PREC_MUL, 0},
  {"/", BINOP_DIV, PREC_MUL, 0},
  {"%", BINOP_REM, PREC_MUL, 0},
  {"@", BINOP_REPEAT, PREC_REPEAT, 0},
  {"+", UNOP_PLUS, PREC_PREFIX, 0},
  {"-", UNOP_NEG, PREC_PREFIX, 0},
  {"!", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
  {"~", UNOP_COMPLEMENT, PREC_PREFIX, 0},
  {"*", UNOP_IND, PREC_PREFIX, 0},
  {"&", UNOP_ADDR, PREC_PREFIX, 0},
  {"sizeof ", UNOP_SIZEOF, PREC_PREFIX, 0},
  {"++", UNOP_PREINCREMENT, PREC_PREFIX, 0},
  {"--", UNOP_PREDECREMENT, PREC_PREFIX, 0},
  {NULL, 0, 0, 0}
};

enum c_primitive_types {
  c_primitive_type_int,
  c_primitive_type_long,
  c_primitive_type_short,
  c_primitive_type_char,
  c_primitive_type_float,
  c_primitive_type_double,
  c_primitive_type_void,
  c_primitive_type_long_long,
  c_primitive_type_signed_char,
  c_primitive_type_unsigned_char,
  c_primitive_type_unsigned_short,
  c_primitive_type_unsigned_int,
  c_primitive_type_unsigned_long,
  c_primitive_type_unsigned_long_long,
  c_primitive_type_long_double,
  c_primitive_type_complex,
  c_primitive_type_double_complex,
  c_primitive_type_decfloat,
  c_primitive_type_decdouble,
  c_primitive_type_declong,
  nr_c_primitive_types
};

void
c_language_arch_info (struct gdbarch *gdbarch,
		      struct language_arch_info *lai)
{
  const struct builtin_type *builtin = builtin_type (gdbarch);

  lai->string_char_type = builtin->builtin_char;
  lai->primitive_type_vector
    = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_c_primitive_types + 1,
			      struct type *);
  lai->primitive_type_vector [c_primitive_type_int] = builtin->builtin_int;
  lai->primitive_type_vector [c_primitive_type_long] = builtin->builtin_long;
  lai->primitive_type_vector [c_primitive_type_short] = builtin->builtin_short;
  lai->primitive_type_vector [c_primitive_type_char] = builtin->builtin_char;
  lai->primitive_type_vector [c_primitive_type_float] = builtin->builtin_float;
  lai->primitive_type_vector [c_primitive_type_double] = builtin->builtin_double;
  lai->primitive_type_vector [c_primitive_type_void] = builtin->builtin_void;
  lai->primitive_type_vector [c_primitive_type_long_long] = builtin->builtin_long_long;
  lai->primitive_type_vector [c_primitive_type_signed_char] = builtin->builtin_signed_char;
  lai->primitive_type_vector [c_primitive_type_unsigned_char] = builtin->builtin_unsigned_char;
  lai->primitive_type_vector [c_primitive_type_unsigned_short] = builtin->builtin_unsigned_short;
  lai->primitive_type_vector [c_primitive_type_unsigned_int] = builtin->builtin_unsigned_int;
  lai->primitive_type_vector [c_primitive_type_unsigned_long] = builtin->builtin_unsigned_long;
  lai->primitive_type_vector [c_primitive_type_unsigned_long_long] = builtin->builtin_unsigned_long_long;
  lai->primitive_type_vector [c_primitive_type_long_double] = builtin->builtin_long_double;
  lai->primitive_type_vector [c_primitive_type_complex] = builtin->builtin_complex;
  lai->primitive_type_vector [c_primitive_type_double_complex] = builtin->builtin_double_complex;
  lai->primitive_type_vector [c_primitive_type_decfloat] = builtin->builtin_decfloat;
  lai->primitive_type_vector [c_primitive_type_decdouble] = builtin->builtin_decdouble;
  lai->primitive_type_vector [c_primitive_type_declong] = builtin->builtin_declong;

  lai->bool_type_default = builtin->builtin_int;
}

const struct exp_descriptor exp_descriptor_c = 
{
  print_subexp_standard,
  operator_length_standard,
  operator_check_standard,
  op_name_standard,
  dump_subexp_body_standard,
  evaluate_subexp_c
};

const struct language_defn c_language_defn =
{
  "c",				/* Language name */
  "C",
  language_c,
  range_check_off,
  case_sensitive_on,
  array_row_major,
  macro_expansion_c,
  &exp_descriptor_c,
  c_parse,
  c_error,
  null_post_parser,
  c_printchar,			/* Print a character constant */
  c_printstr,			/* Function to print string constant */
  c_emit_char,			/* Print a single char */
  c_print_type,			/* Print a type using appropriate syntax */
  c_print_typedef,		/* Print a typedef using appropriate syntax */
  c_val_print,			/* Print a value using appropriate syntax */
  c_value_print,		/* Print a top-level value */
  default_read_var_value,	/* la_read_var_value */
  NULL,				/* Language specific skip_trampoline */
  NULL,				/* name_of_this */
  basic_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
  basic_lookup_transparent_type,/* lookup_transparent_type */
  NULL,				/* Language specific symbol demangler */
  NULL,				/* Language specific
				   class_name_from_physname */
  c_op_print_tab,		/* expression operators for printing */
  1,				/* c-style arrays */
  0,				/* String lower bound */
  default_word_break_characters,
  default_make_symbol_completion_list,
  c_language_arch_info,
  default_print_array_index,
  default_pass_by_reference,
  c_get_string,
  NULL,				/* la_get_symbol_name_cmp */
  iterate_over_symbols,
  &c_varobj_ops,
  LANG_MAGIC
};

enum cplus_primitive_types {
  cplus_primitive_type_int,
  cplus_primitive_type_long,
  cplus_primitive_type_short,
  cplus_primitive_type_char,
  cplus_primitive_type_float,
  cplus_primitive_type_double,
  cplus_primitive_type_void,
  cplus_primitive_type_long_long,
  cplus_primitive_type_signed_char,
  cplus_primitive_type_unsigned_char,
  cplus_primitive_type_unsigned_short,
  cplus_primitive_type_unsigned_int,
  cplus_primitive_type_unsigned_long,
  cplus_primitive_type_unsigned_long_long,
  cplus_primitive_type_long_double,
  cplus_primitive_type_complex,
  cplus_primitive_type_double_complex,
  cplus_primitive_type_bool,
  cplus_primitive_type_decfloat,
  cplus_primitive_type_decdouble,
  cplus_primitive_type_declong,
  nr_cplus_primitive_types
};

static void
cplus_language_arch_info (struct gdbarch *gdbarch,
			  struct language_arch_info *lai)
{
  const struct builtin_type *builtin = builtin_type (gdbarch);

  lai->string_char_type = builtin->builtin_char;
  lai->primitive_type_vector
    = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_cplus_primitive_types + 1,
			      struct type *);
  lai->primitive_type_vector [cplus_primitive_type_int]
    = builtin->builtin_int;
  lai->primitive_type_vector [cplus_primitive_type_long]
    = builtin->builtin_long;
  lai->primitive_type_vector [cplus_primitive_type_short]
    = builtin->builtin_short;
  lai->primitive_type_vector [cplus_primitive_type_char]
    = builtin->builtin_char;
  lai->primitive_type_vector [cplus_primitive_type_float]
    = builtin->builtin_float;
  lai->primitive_type_vector [cplus_primitive_type_double]
    = builtin->builtin_double;
  lai->primitive_type_vector [cplus_primitive_type_void]
    = builtin->builtin_void;
  lai->primitive_type_vector [cplus_primitive_type_long_long]
    = builtin->builtin_long_long;
  lai->primitive_type_vector [cplus_primitive_type_signed_char]
    = builtin->builtin_signed_char;
  lai->primitive_type_vector [cplus_primitive_type_unsigned_char]
    = builtin->builtin_unsigned_char;
  lai->primitive_type_vector [cplus_primitive_type_unsigned_short]
    = builtin->builtin_unsigned_short;
  lai->primitive_type_vector [cplus_primitive_type_unsigned_int]
    = builtin->builtin_unsigned_int;
  lai->primitive_type_vector [cplus_primitive_type_unsigned_long]
    = builtin->builtin_unsigned_long;
  lai->primitive_type_vector [cplus_primitive_type_unsigned_long_long]
    = builtin->builtin_unsigned_long_long;
  lai->primitive_type_vector [cplus_primitive_type_long_double]
    = builtin->builtin_long_double;
  lai->primitive_type_vector [cplus_primitive_type_complex]
    = builtin->builtin_complex;
  lai->primitive_type_vector [cplus_primitive_type_double_complex]
    = builtin->builtin_double_complex;
  lai->primitive_type_vector [cplus_primitive_type_bool]
    = builtin->builtin_bool;
  lai->primitive_type_vector [cplus_primitive_type_decfloat]
    = builtin->builtin_decfloat;
  lai->primitive_type_vector [cplus_primitive_type_decdouble]
    = builtin->builtin_decdouble;
  lai->primitive_type_vector [cplus_primitive_type_declong]
    = builtin->builtin_declong;

  lai->bool_type_symbol = "bool";
  lai->bool_type_default = builtin->builtin_bool;
}

const struct language_defn cplus_language_defn =
{
  "c++",			/* Language name */
  "C++",
  language_cplus,
  range_check_off,
  case_sensitive_on,
  array_row_major,
  macro_expansion_c,
  &exp_descriptor_c,
  c_parse,
  c_error,
  null_post_parser,
  c_printchar,			/* Print a character constant */
  c_printstr,			/* Function to print string constant */
  c_emit_char,			/* Print a single char */
  c_print_type,			/* Print a type using appropriate syntax */
  c_print_typedef,		/* Print a typedef using appropriate syntax */
  c_val_print,			/* Print a value using appropriate syntax */
  c_value_print,		/* Print a top-level value */
  default_read_var_value,	/* la_read_var_value */
  cplus_skip_trampoline,	/* Language specific skip_trampoline */
  "this",                       /* name_of_this */
  cp_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
  cp_lookup_transparent_type,   /* lookup_transparent_type */
  gdb_demangle,			/* Language specific symbol demangler */
  cp_class_name_from_physname,  /* Language specific
				   class_name_from_physname */
  c_op_print_tab,		/* expression operators for printing */
  1,				/* c-style arrays */
  0,				/* String lower bound */
  default_word_break_characters,
  default_make_symbol_completion_list,
  cplus_language_arch_info,
  default_print_array_index,
  cp_pass_by_reference,
  c_get_string,
  NULL,				/* la_get_symbol_name_cmp */
  iterate_over_symbols,
  &cplus_varobj_ops,
  LANG_MAGIC
};

const struct language_defn asm_language_defn =
{
  "asm",			/* Language name */
  "assembly",
  language_asm,
  range_check_off,
  case_sensitive_on,
  array_row_major,
  macro_expansion_c,
  &exp_descriptor_c,
  c_parse,
  c_error,
  null_post_parser,
  c_printchar,			/* Print a character constant */
  c_printstr,			/* Function to print string constant */
  c_emit_char,			/* Print a single char */
  c_print_type,			/* Print a type using appropriate syntax */
  c_print_typedef,		/* Print a typedef using appropriate syntax */
  c_val_print,			/* Print a value using appropriate syntax */
  c_value_print,		/* Print a top-level value */
  default_read_var_value,	/* la_read_var_value */
  NULL,				/* Language specific skip_trampoline */
  NULL,				/* name_of_this */
  basic_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
  basic_lookup_transparent_type,/* lookup_transparent_type */
  NULL,				/* Language specific symbol demangler */
  NULL,				/* Language specific
				   class_name_from_physname */
  c_op_print_tab,		/* expression operators for printing */
  1,				/* c-style arrays */
  0,				/* String lower bound */
  default_word_break_characters,
  default_make_symbol_completion_list,
  c_language_arch_info, 	/* FIXME: la_language_arch_info.  */
  default_print_array_index,
  default_pass_by_reference,
  c_get_string,
  NULL,				/* la_get_symbol_name_cmp */
  iterate_over_symbols,
  &default_varobj_ops,
  LANG_MAGIC
};

/* The following language_defn does not represent a real language.
   It just provides a minimal support a-la-C that should allow users
   to do some simple operations when debugging applications that use
   a language currently not supported by GDB.  */

const struct language_defn minimal_language_defn =
{
  "minimal",			/* Language name */
  "Minimal",
  language_minimal,
  range_check_off,
  case_sensitive_on,
  array_row_major,
  macro_expansion_c,
  &exp_descriptor_c,
  c_parse,
  c_error,
  null_post_parser,
  c_printchar,			/* Print a character constant */
  c_printstr,			/* Function to print string constant */
  c_emit_char,			/* Print a single char */
  c_print_type,			/* Print a type using appropriate syntax */
  c_print_typedef,		/* Print a typedef using appropriate syntax */
  c_val_print,			/* Print a value using appropriate syntax */
  c_value_print,		/* Print a top-level value */
  default_read_var_value,	/* la_read_var_value */
  NULL,				/* Language specific skip_trampoline */
  NULL,				/* name_of_this */
  basic_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
  basic_lookup_transparent_type,/* lookup_transparent_type */
  NULL,				/* Language specific symbol demangler */
  NULL,				/* Language specific
				   class_name_from_physname */
  c_op_print_tab,		/* expression operators for printing */
  1,				/* c-style arrays */
  0,				/* String lower bound */
  default_word_break_characters,
  default_make_symbol_completion_list,
  c_language_arch_info,
  default_print_array_index,
  default_pass_by_reference,
  c_get_string,
  NULL,				/* la_get_symbol_name_cmp */
  iterate_over_symbols,
  &default_varobj_ops,
  LANG_MAGIC
};

void
_initialize_c_language (void)
{
  add_language (&c_language_defn);
  add_language (&cplus_language_defn);
  add_language (&asm_language_defn);
  add_language (&minimal_language_defn);
}