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[/] [or1k/] [trunk/] [insight/] [gdb/] [values.c] - Blame information for rev 1765

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1 578 markom
/* Low level packing and unpacking of values for GDB, the GNU Debugger.
2
   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
3
   1996, 1997, 1998, 1999, 2000
4
   Free Software Foundation, Inc.
5
 
6
   This file is part of GDB.
7
 
8
   This program is free software; you can redistribute it and/or modify
9
   it under the terms of the GNU General Public License as published by
10
   the Free Software Foundation; either version 2 of the License, or
11
   (at your option) any later version.
12
 
13
   This program is distributed in the hope that it will be useful,
14
   but WITHOUT ANY WARRANTY; without even the implied warranty of
15
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16
   GNU General Public License for more details.
17
 
18
   You should have received a copy of the GNU General Public License
19
   along with this program; if not, write to the Free Software
20
   Foundation, Inc., 59 Temple Place - Suite 330,
21
   Boston, MA 02111-1307, USA.  */
22
 
23
#include "defs.h"
24
#include "gdb_string.h"
25
#include "symtab.h"
26
#include "gdbtypes.h"
27
#include "value.h"
28
#include "gdbcore.h"
29
#include "command.h"
30
#include "gdbcmd.h"
31
#include "target.h"
32
#include "language.h"
33
#include "scm-lang.h"
34
#include "demangle.h"
35
 
36
/* Prototypes for exported functions. */
37
 
38
void _initialize_values (void);
39
 
40
/* Prototypes for local functions. */
41
 
42
static value_ptr value_headof (value_ptr, struct type *, struct type *);
43
 
44
static void show_values (char *, int);
45
 
46
static void show_convenience (char *, int);
47
 
48
 
49
/* The value-history records all the values printed
50
   by print commands during this session.  Each chunk
51
   records 60 consecutive values.  The first chunk on
52
   the chain records the most recent values.
53
   The total number of values is in value_history_count.  */
54
 
55
#define VALUE_HISTORY_CHUNK 60
56
 
57
struct value_history_chunk
58
  {
59
    struct value_history_chunk *next;
60
    value_ptr values[VALUE_HISTORY_CHUNK];
61
  };
62
 
63
/* Chain of chunks now in use.  */
64
 
65
static struct value_history_chunk *value_history_chain;
66
 
67
static int value_history_count; /* Abs number of last entry stored */
68
 
69
/* List of all value objects currently allocated
70
   (except for those released by calls to release_value)
71
   This is so they can be freed after each command.  */
72
 
73
static value_ptr all_values;
74
 
75
/* Allocate a  value  that has the correct length for type TYPE.  */
76
 
77
value_ptr
78
allocate_value (struct type *type)
79
{
80
  register value_ptr val;
81
  struct type *atype = check_typedef (type);
82
 
83
  val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype));
84
  VALUE_NEXT (val) = all_values;
85
  all_values = val;
86
  VALUE_TYPE (val) = type;
87
  VALUE_ENCLOSING_TYPE (val) = type;
88
  VALUE_LVAL (val) = not_lval;
89
  VALUE_ADDRESS (val) = 0;
90
  VALUE_FRAME (val) = 0;
91
  VALUE_OFFSET (val) = 0;
92
  VALUE_BITPOS (val) = 0;
93
  VALUE_BITSIZE (val) = 0;
94
  VALUE_REGNO (val) = -1;
95
  VALUE_LAZY (val) = 0;
96
  VALUE_OPTIMIZED_OUT (val) = 0;
97
  VALUE_BFD_SECTION (val) = NULL;
98
  VALUE_EMBEDDED_OFFSET (val) = 0;
99
  VALUE_POINTED_TO_OFFSET (val) = 0;
100
  val->modifiable = 1;
101
  return val;
102
}
103
 
104
/* Allocate a  value  that has the correct length
105
   for COUNT repetitions type TYPE.  */
106
 
107
value_ptr
108
allocate_repeat_value (struct type *type, int count)
109
{
110
  int low_bound = current_language->string_lower_bound;         /* ??? */
111
  /* FIXME-type-allocation: need a way to free this type when we are
112
     done with it.  */
113
  struct type *range_type
114
  = create_range_type ((struct type *) NULL, builtin_type_int,
115
                       low_bound, count + low_bound - 1);
116
  /* FIXME-type-allocation: need a way to free this type when we are
117
     done with it.  */
118
  return allocate_value (create_array_type ((struct type *) NULL,
119
                                            type, range_type));
120
}
121
 
122
/* Return a mark in the value chain.  All values allocated after the
123
   mark is obtained (except for those released) are subject to being freed
124
   if a subsequent value_free_to_mark is passed the mark.  */
125
value_ptr
126
value_mark (void)
127
{
128
  return all_values;
129
}
130
 
131
/* Free all values allocated since MARK was obtained by value_mark
132
   (except for those released).  */
133
void
134
value_free_to_mark (value_ptr mark)
135
{
136
  value_ptr val, next;
137
 
138
  for (val = all_values; val && val != mark; val = next)
139
    {
140
      next = VALUE_NEXT (val);
141
      value_free (val);
142
    }
143
  all_values = val;
144
}
145
 
146
/* Free all the values that have been allocated (except for those released).
147
   Called after each command, successful or not.  */
148
 
149
void
150
free_all_values (void)
151
{
152
  register value_ptr val, next;
153
 
154
  for (val = all_values; val; val = next)
155
    {
156
      next = VALUE_NEXT (val);
157
      value_free (val);
158
    }
159
 
160
  all_values = 0;
161
}
162
 
163
/* Remove VAL from the chain all_values
164
   so it will not be freed automatically.  */
165
 
166
void
167
release_value (register value_ptr val)
168
{
169
  register value_ptr v;
170
 
171
  if (all_values == val)
172
    {
173
      all_values = val->next;
174
      return;
175
    }
176
 
177
  for (v = all_values; v; v = v->next)
178
    {
179
      if (v->next == val)
180
        {
181
          v->next = val->next;
182
          break;
183
        }
184
    }
185
}
186
 
187
/* Release all values up to mark  */
188
value_ptr
189
value_release_to_mark (value_ptr mark)
190
{
191
  value_ptr val, next;
192
 
193
  for (val = next = all_values; next; next = VALUE_NEXT (next))
194
    if (VALUE_NEXT (next) == mark)
195
      {
196
        all_values = VALUE_NEXT (next);
197
        VALUE_NEXT (next) = 0;
198
        return val;
199
      }
200
  all_values = 0;
201
  return val;
202
}
203
 
204
/* Return a copy of the value ARG.
205
   It contains the same contents, for same memory address,
206
   but it's a different block of storage.  */
207
 
208
value_ptr
209
value_copy (value_ptr arg)
210
{
211
  register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg);
212
  register value_ptr val = allocate_value (encl_type);
213
  VALUE_TYPE (val) = VALUE_TYPE (arg);
214
  VALUE_LVAL (val) = VALUE_LVAL (arg);
215
  VALUE_ADDRESS (val) = VALUE_ADDRESS (arg);
216
  VALUE_OFFSET (val) = VALUE_OFFSET (arg);
217
  VALUE_BITPOS (val) = VALUE_BITPOS (arg);
218
  VALUE_BITSIZE (val) = VALUE_BITSIZE (arg);
219
  VALUE_FRAME (val) = VALUE_FRAME (arg);
220
  VALUE_REGNO (val) = VALUE_REGNO (arg);
221
  VALUE_LAZY (val) = VALUE_LAZY (arg);
222
  VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg);
223
  VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg);
224
  VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg);
225
  VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg);
226
  val->modifiable = arg->modifiable;
227
  if (!VALUE_LAZY (val))
228
    {
229
      memcpy (VALUE_CONTENTS_ALL_RAW (val), VALUE_CONTENTS_ALL_RAW (arg),
230
              TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg)));
231
 
232
    }
233
  return val;
234
}
235
 
236
/* Access to the value history.  */
237
 
238
/* Record a new value in the value history.
239
   Returns the absolute history index of the entry.
240
   Result of -1 indicates the value was not saved; otherwise it is the
241
   value history index of this new item.  */
242
 
243
int
244
record_latest_value (value_ptr val)
245
{
246
  int i;
247
 
248
  /* We don't want this value to have anything to do with the inferior anymore.
249
     In particular, "set $1 = 50" should not affect the variable from which
250
     the value was taken, and fast watchpoints should be able to assume that
251
     a value on the value history never changes.  */
252
  if (VALUE_LAZY (val))
253
    value_fetch_lazy (val);
254
  /* We preserve VALUE_LVAL so that the user can find out where it was fetched
255
     from.  This is a bit dubious, because then *&$1 does not just return $1
256
     but the current contents of that location.  c'est la vie...  */
257
  val->modifiable = 0;
258
  release_value (val);
259
 
260
  /* Here we treat value_history_count as origin-zero
261
     and applying to the value being stored now.  */
262
 
263
  i = value_history_count % VALUE_HISTORY_CHUNK;
264
  if (i == 0)
265
    {
266
      register struct value_history_chunk *new
267
      = (struct value_history_chunk *)
268
      xmalloc (sizeof (struct value_history_chunk));
269
      memset (new->values, 0, sizeof new->values);
270
      new->next = value_history_chain;
271
      value_history_chain = new;
272
    }
273
 
274
  value_history_chain->values[i] = val;
275
 
276
  /* Now we regard value_history_count as origin-one
277
     and applying to the value just stored.  */
278
 
279
  return ++value_history_count;
280
}
281
 
282
/* Return a copy of the value in the history with sequence number NUM.  */
283
 
284
value_ptr
285
access_value_history (int num)
286
{
287
  register struct value_history_chunk *chunk;
288
  register int i;
289
  register int absnum = num;
290
 
291
  if (absnum <= 0)
292
    absnum += value_history_count;
293
 
294
  if (absnum <= 0)
295
    {
296
      if (num == 0)
297
        error ("The history is empty.");
298
      else if (num == 1)
299
        error ("There is only one value in the history.");
300
      else
301
        error ("History does not go back to $$%d.", -num);
302
    }
303
  if (absnum > value_history_count)
304
    error ("History has not yet reached $%d.", absnum);
305
 
306
  absnum--;
307
 
308
  /* Now absnum is always absolute and origin zero.  */
309
 
310
  chunk = value_history_chain;
311
  for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK;
312
       i > 0; i--)
313
    chunk = chunk->next;
314
 
315
  return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
316
}
317
 
318
/* Clear the value history entirely.
319
   Must be done when new symbol tables are loaded,
320
   because the type pointers become invalid.  */
321
 
322
void
323
clear_value_history (void)
324
{
325
  register struct value_history_chunk *next;
326
  register int i;
327
  register value_ptr val;
328
 
329
  while (value_history_chain)
330
    {
331
      for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
332
        if ((val = value_history_chain->values[i]) != NULL)
333
          xfree (val);
334
      next = value_history_chain->next;
335
      xfree (value_history_chain);
336
      value_history_chain = next;
337
    }
338
  value_history_count = 0;
339
}
340
 
341
static void
342
show_values (char *num_exp, int from_tty)
343
{
344
  register int i;
345
  register value_ptr val;
346
  static int num = 1;
347
 
348
  if (num_exp)
349
    {
350
      /* "info history +" should print from the stored position.
351
         "info history <exp>" should print around value number <exp>.  */
352
      if (num_exp[0] != '+' || num_exp[1] != '\0')
353
        num = parse_and_eval_long (num_exp) - 5;
354
    }
355
  else
356
    {
357
      /* "info history" means print the last 10 values.  */
358
      num = value_history_count - 9;
359
    }
360
 
361
  if (num <= 0)
362
    num = 1;
363
 
364
  for (i = num; i < num + 10 && i <= value_history_count; i++)
365
    {
366
      val = access_value_history (i);
367
      printf_filtered ("$%d = ", i);
368
      value_print (val, gdb_stdout, 0, Val_pretty_default);
369
      printf_filtered ("\n");
370
    }
371
 
372
  /* The next "info history +" should start after what we just printed.  */
373
  num += 10;
374
 
375
  /* Hitting just return after this command should do the same thing as
376
     "info history +".  If num_exp is null, this is unnecessary, since
377
     "info history +" is not useful after "info history".  */
378
  if (from_tty && num_exp)
379
    {
380
      num_exp[0] = '+';
381
      num_exp[1] = '\0';
382
    }
383
}
384
 
385
/* Internal variables.  These are variables within the debugger
386
   that hold values assigned by debugger commands.
387
   The user refers to them with a '$' prefix
388
   that does not appear in the variable names stored internally.  */
389
 
390
static struct internalvar *internalvars;
391
 
392
/* Look up an internal variable with name NAME.  NAME should not
393
   normally include a dollar sign.
394
 
395
   If the specified internal variable does not exist,
396
   one is created, with a void value.  */
397
 
398
struct internalvar *
399
lookup_internalvar (char *name)
400
{
401
  register struct internalvar *var;
402
 
403
  for (var = internalvars; var; var = var->next)
404
    if (STREQ (var->name, name))
405
      return var;
406
 
407
  var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
408
  var->name = concat (name, NULL);
409
  var->value = allocate_value (builtin_type_void);
410
  release_value (var->value);
411
  var->next = internalvars;
412
  internalvars = var;
413
  return var;
414
}
415
 
416
value_ptr
417
value_of_internalvar (struct internalvar *var)
418
{
419
  register value_ptr val;
420
 
421
#ifdef IS_TRAPPED_INTERNALVAR
422
  if (IS_TRAPPED_INTERNALVAR (var->name))
423
    return VALUE_OF_TRAPPED_INTERNALVAR (var);
424
#endif
425
 
426
  val = value_copy (var->value);
427
  if (VALUE_LAZY (val))
428
    value_fetch_lazy (val);
429
  VALUE_LVAL (val) = lval_internalvar;
430
  VALUE_INTERNALVAR (val) = var;
431
  return val;
432
}
433
 
434
void
435
set_internalvar_component (struct internalvar *var, int offset, int bitpos,
436
                           int bitsize, value_ptr newval)
437
{
438
  register char *addr = VALUE_CONTENTS (var->value) + offset;
439
 
440
#ifdef IS_TRAPPED_INTERNALVAR
441
  if (IS_TRAPPED_INTERNALVAR (var->name))
442
    SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset);
443
#endif
444
 
445
  if (bitsize)
446
    modify_field (addr, value_as_long (newval),
447
                  bitpos, bitsize);
448
  else
449
    memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval)));
450
}
451
 
452
void
453
set_internalvar (struct internalvar *var, value_ptr val)
454
{
455
  value_ptr newval;
456
 
457
#ifdef IS_TRAPPED_INTERNALVAR
458
  if (IS_TRAPPED_INTERNALVAR (var->name))
459
    SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0);
460
#endif
461
 
462
  newval = value_copy (val);
463
  newval->modifiable = 1;
464
 
465
  /* Force the value to be fetched from the target now, to avoid problems
466
     later when this internalvar is referenced and the target is gone or
467
     has changed.  */
468
  if (VALUE_LAZY (newval))
469
    value_fetch_lazy (newval);
470
 
471
  /* Begin code which must not call error().  If var->value points to
472
     something free'd, an error() obviously leaves a dangling pointer.
473
     But we also get a danling pointer if var->value points to
474
     something in the value chain (i.e., before release_value is
475
     called), because after the error free_all_values will get called before
476
     long.  */
477
  xfree (var->value);
478
  var->value = newval;
479
  release_value (newval);
480
  /* End code which must not call error().  */
481
}
482
 
483
char *
484
internalvar_name (struct internalvar *var)
485
{
486
  return var->name;
487
}
488
 
489
/* Free all internalvars.  Done when new symtabs are loaded,
490
   because that makes the values invalid.  */
491
 
492
void
493
clear_internalvars (void)
494
{
495
  register struct internalvar *var;
496
 
497
  while (internalvars)
498
    {
499
      var = internalvars;
500
      internalvars = var->next;
501
      xfree (var->name);
502
      xfree (var->value);
503
      xfree (var);
504
    }
505
}
506
 
507
static void
508
show_convenience (char *ignore, int from_tty)
509
{
510
  register struct internalvar *var;
511
  int varseen = 0;
512
 
513
  for (var = internalvars; var; var = var->next)
514
    {
515
#ifdef IS_TRAPPED_INTERNALVAR
516
      if (IS_TRAPPED_INTERNALVAR (var->name))
517
        continue;
518
#endif
519
      if (!varseen)
520
        {
521
          varseen = 1;
522
        }
523
      printf_filtered ("$%s = ", var->name);
524
      value_print (var->value, gdb_stdout, 0, Val_pretty_default);
525
      printf_filtered ("\n");
526
    }
527
  if (!varseen)
528
    printf_unfiltered ("No debugger convenience variables now defined.\n\
529
Convenience variables have names starting with \"$\";\n\
530
use \"set\" as in \"set $foo = 5\" to define them.\n");
531
}
532
 
533
/* Extract a value as a C number (either long or double).
534
   Knows how to convert fixed values to double, or
535
   floating values to long.
536
   Does not deallocate the value.  */
537
 
538
LONGEST
539
value_as_long (register value_ptr val)
540
{
541
  /* This coerces arrays and functions, which is necessary (e.g.
542
     in disassemble_command).  It also dereferences references, which
543
     I suspect is the most logical thing to do.  */
544
  COERCE_ARRAY (val);
545
  return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
546
}
547
 
548
DOUBLEST
549
value_as_double (register value_ptr val)
550
{
551
  DOUBLEST foo;
552
  int inv;
553
 
554
  foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv);
555
  if (inv)
556
    error ("Invalid floating value found in program.");
557
  return foo;
558
}
559
/* Extract a value as a C pointer. Does not deallocate the value.
560
   Note that val's type may not actually be a pointer; value_as_long
561
   handles all the cases.  */
562
CORE_ADDR
563
value_as_pointer (value_ptr val)
564
{
565
  /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
566
     whether we want this to be true eventually.  */
567
#if 0
568
  /* ADDR_BITS_REMOVE is wrong if we are being called for a
569
     non-address (e.g. argument to "signal", "info break", etc.), or
570
     for pointers to char, in which the low bits *are* significant.  */
571
  return ADDR_BITS_REMOVE (value_as_long (val));
572
#else
573
  COERCE_ARRAY (val);
574
  /* In converting VAL to an address (CORE_ADDR), any small integers
575
     are first cast to a generic pointer.  The function unpack_long
576
     will then correctly convert that pointer into a canonical address
577
     (using POINTER_TO_ADDRESS).
578
 
579
     Without the cast, the MIPS gets: 0xa0000000 -> (unsigned int)
580
     0xa0000000 -> (LONGEST) 0x00000000a0000000
581
 
582
     With the cast, the MIPS gets: 0xa0000000 -> (unsigned int)
583
     0xa0000000 -> (void*) 0xa0000000 -> (LONGEST) 0xffffffffa0000000.
584
 
585
     If the user specifies an integer that is larger than the target
586
     pointer type, it is assumed that it was intentional and the value
587
     is converted directly into an ADDRESS.  This ensures that no
588
     information is discarded.
589
 
590
     NOTE: The cast operation may eventualy be converted into a TARGET
591
     method (see POINTER_TO_ADDRESS() and ADDRESS_TO_POINTER()) so
592
     that the TARGET ISA/ABI can apply an arbitrary conversion.
593
 
594
     NOTE: In pure harvard architectures function and data pointers
595
     can be different and may require different integer to pointer
596
     conversions. */
597
  if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT
598
      && TYPE_LENGTH (VALUE_TYPE (val)) <= TYPE_LENGTH (builtin_type_ptr))
599
    {
600
      val = value_cast (builtin_type_ptr, val);
601
    }
602
  return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val));
603
#endif
604
}
605
 
606
/* Unpack raw data (copied from debugee, target byte order) at VALADDR
607
   as a long, or as a double, assuming the raw data is described
608
   by type TYPE.  Knows how to convert different sizes of values
609
   and can convert between fixed and floating point.  We don't assume
610
   any alignment for the raw data.  Return value is in host byte order.
611
 
612
   If you want functions and arrays to be coerced to pointers, and
613
   references to be dereferenced, call value_as_long() instead.
614
 
615
   C++: It is assumed that the front-end has taken care of
616
   all matters concerning pointers to members.  A pointer
617
   to member which reaches here is considered to be equivalent
618
   to an INT (or some size).  After all, it is only an offset.  */
619
 
620
LONGEST
621
unpack_long (struct type *type, char *valaddr)
622
{
623
  register enum type_code code = TYPE_CODE (type);
624
  register int len = TYPE_LENGTH (type);
625
  register int nosign = TYPE_UNSIGNED (type);
626
 
627
  if (current_language->la_language == language_scm
628
      && is_scmvalue_type (type))
629
    return scm_unpack (type, valaddr, TYPE_CODE_INT);
630
 
631
  switch (code)
632
    {
633
    case TYPE_CODE_TYPEDEF:
634
      return unpack_long (check_typedef (type), valaddr);
635
    case TYPE_CODE_ENUM:
636
    case TYPE_CODE_BOOL:
637
    case TYPE_CODE_INT:
638
    case TYPE_CODE_CHAR:
639
    case TYPE_CODE_RANGE:
640
      if (nosign)
641
        return extract_unsigned_integer (valaddr, len);
642
      else
643
        return extract_signed_integer (valaddr, len);
644
 
645
    case TYPE_CODE_FLT:
646
      return extract_floating (valaddr, len);
647
 
648
    case TYPE_CODE_PTR:
649
    case TYPE_CODE_REF:
650
      /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
651
         whether we want this to be true eventually.  */
652
      if (GDB_TARGET_IS_D10V
653
          && len == 2)
654
        return D10V_MAKE_DADDR (extract_address (valaddr, len));
655
      return extract_typed_address (valaddr, type);
656
 
657
    case TYPE_CODE_MEMBER:
658
      error ("not implemented: member types in unpack_long");
659
 
660
    default:
661
      error ("Value can't be converted to integer.");
662
    }
663
  return 0;                      /* Placate lint.  */
664
}
665
 
666
/* Return a double value from the specified type and address.
667
   INVP points to an int which is set to 0 for valid value,
668
   1 for invalid value (bad float format).  In either case,
669
   the returned double is OK to use.  Argument is in target
670
   format, result is in host format.  */
671
 
672
DOUBLEST
673
unpack_double (struct type *type, char *valaddr, int *invp)
674
{
675
  enum type_code code;
676
  int len;
677
  int nosign;
678
 
679
  *invp = 0;                     /* Assume valid.   */
680
  CHECK_TYPEDEF (type);
681
  code = TYPE_CODE (type);
682
  len = TYPE_LENGTH (type);
683
  nosign = TYPE_UNSIGNED (type);
684
  if (code == TYPE_CODE_FLT)
685
    {
686
#ifdef INVALID_FLOAT
687
      if (INVALID_FLOAT (valaddr, len))
688
        {
689
          *invp = 1;
690
          return 1.234567891011121314;
691
        }
692
#endif
693
      return extract_floating (valaddr, len);
694
    }
695
  else if (nosign)
696
    {
697
      /* Unsigned -- be sure we compensate for signed LONGEST.  */
698
      return (ULONGEST) unpack_long (type, valaddr);
699
    }
700
  else
701
    {
702
      /* Signed -- we are OK with unpack_long.  */
703
      return unpack_long (type, valaddr);
704
    }
705
}
706
 
707
/* Unpack raw data (copied from debugee, target byte order) at VALADDR
708
   as a CORE_ADDR, assuming the raw data is described by type TYPE.
709
   We don't assume any alignment for the raw data.  Return value is in
710
   host byte order.
711
 
712
   If you want functions and arrays to be coerced to pointers, and
713
   references to be dereferenced, call value_as_pointer() instead.
714
 
715
   C++: It is assumed that the front-end has taken care of
716
   all matters concerning pointers to members.  A pointer
717
   to member which reaches here is considered to be equivalent
718
   to an INT (or some size).  After all, it is only an offset.  */
719
 
720
CORE_ADDR
721
unpack_pointer (struct type *type, char *valaddr)
722
{
723
  /* Assume a CORE_ADDR can fit in a LONGEST (for now).  Not sure
724
     whether we want this to be true eventually.  */
725
  return unpack_long (type, valaddr);
726
}
727
 
728
 
729
/* Get the value of the FIELDN'th field (which must be static) of TYPE. */
730
 
731
value_ptr
732
value_static_field (struct type *type, int fieldno)
733
{
734
  CORE_ADDR addr;
735
  asection *sect;
736
  if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno))
737
    {
738
      addr = TYPE_FIELD_STATIC_PHYSADDR (type, fieldno);
739
      sect = NULL;
740
    }
741
  else
742
    {
743
      char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
744
      struct symbol *sym = lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL);
745
      if (sym == NULL)
746
        {
747
          /* With some compilers, e.g. HP aCC, static data members are reported
748
             as non-debuggable symbols */
749
          struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL);
750
          if (!msym)
751
            return NULL;
752
          else
753
            {
754
              addr = SYMBOL_VALUE_ADDRESS (msym);
755
              sect = SYMBOL_BFD_SECTION (msym);
756
            }
757
        }
758
      else
759
        {
760
          /* Anything static that isn't a constant, has an address */
761
          if (SYMBOL_CLASS (sym) != LOC_CONST)
762
            {
763
              addr = SYMBOL_VALUE_ADDRESS (sym);
764
              sect = SYMBOL_BFD_SECTION (sym);
765
            }
766
          /* However, static const's do not, the value is already known.  */
767
          else
768
            {
769
              return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), SYMBOL_VALUE (sym));
770
            }
771
        }
772
      SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), addr);
773
    }
774
  return value_at (TYPE_FIELD_TYPE (type, fieldno), addr, sect);
775
}
776
 
777
/* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
778
   You have to be careful here, since the size of the data area for the value
779
   is set by the length of the enclosing type.  So if NEW_ENCL_TYPE is bigger
780
   than the old enclosing type, you have to allocate more space for the data.
781
   The return value is a pointer to the new version of this value structure. */
782
 
783
value_ptr
784
value_change_enclosing_type (value_ptr val, struct type *new_encl_type)
785
{
786
  if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val)))
787
    {
788
      VALUE_ENCLOSING_TYPE (val) = new_encl_type;
789
      return val;
790
    }
791
  else
792
    {
793
      value_ptr new_val;
794
      register value_ptr prev;
795
 
796
      new_val = (value_ptr) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type));
797
 
798
      /* We have to make sure this ends up in the same place in the value
799
         chain as the original copy, so it's clean-up behavior is the same.
800
         If the value has been released, this is a waste of time, but there
801
         is no way to tell that in advance, so... */
802
 
803
      if (val != all_values)
804
        {
805
          for (prev = all_values; prev != NULL; prev = prev->next)
806
            {
807
              if (prev->next == val)
808
                {
809
                  prev->next = new_val;
810
                  break;
811
                }
812
            }
813
        }
814
 
815
      return new_val;
816
    }
817
}
818
 
819
/* Given a value ARG1 (offset by OFFSET bytes)
820
   of a struct or union type ARG_TYPE,
821
   extract and return the value of one of its (non-static) fields.
822
   FIELDNO says which field. */
823
 
824
value_ptr
825
value_primitive_field (register value_ptr arg1, int offset,
826
                       register int fieldno, register struct type *arg_type)
827
{
828
  register value_ptr v;
829
  register struct type *type;
830
 
831
  CHECK_TYPEDEF (arg_type);
832
  type = TYPE_FIELD_TYPE (arg_type, fieldno);
833
 
834
  /* Handle packed fields */
835
 
836
  if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
837
    {
838
      v = value_from_longest (type,
839
                              unpack_field_as_long (arg_type,
840
                                                    VALUE_CONTENTS (arg1)
841
                                                    + offset,
842
                                                    fieldno));
843
      VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8;
844
      VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno);
845
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
846
        + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
847
    }
848
  else if (fieldno < TYPE_N_BASECLASSES (arg_type))
849
    {
850
      /* This field is actually a base subobject, so preserve the
851
         entire object's contents for later references to virtual
852
         bases, etc.  */
853
      v = allocate_value (VALUE_ENCLOSING_TYPE (arg1));
854
      VALUE_TYPE (v) = type;
855
      if (VALUE_LAZY (arg1))
856
        VALUE_LAZY (v) = 1;
857
      else
858
        memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1),
859
                TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1)));
860
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1);
861
      VALUE_EMBEDDED_OFFSET (v)
862
        = offset +
863
        VALUE_EMBEDDED_OFFSET (arg1) +
864
        TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
865
    }
866
  else
867
    {
868
      /* Plain old data member */
869
      offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
870
      v = allocate_value (type);
871
      if (VALUE_LAZY (arg1))
872
        VALUE_LAZY (v) = 1;
873
      else
874
        memcpy (VALUE_CONTENTS_RAW (v),
875
                VALUE_CONTENTS_RAW (arg1) + offset,
876
                TYPE_LENGTH (type));
877
      VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset;
878
    }
879
  VALUE_LVAL (v) = VALUE_LVAL (arg1);
880
  if (VALUE_LVAL (arg1) == lval_internalvar)
881
    VALUE_LVAL (v) = lval_internalvar_component;
882
  VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1);
883
  VALUE_REGNO (v) = VALUE_REGNO (arg1);
884
/*  VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
885
   + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */
886
  return v;
887
}
888
 
889
/* Given a value ARG1 of a struct or union type,
890
   extract and return the value of one of its (non-static) fields.
891
   FIELDNO says which field. */
892
 
893
value_ptr
894
value_field (register value_ptr arg1, register int fieldno)
895
{
896
  return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1));
897
}
898
 
899
/* Return a non-virtual function as a value.
900
   F is the list of member functions which contains the desired method.
901
   J is an index into F which provides the desired method. */
902
 
903
value_ptr
904
value_fn_field (value_ptr *arg1p, struct fn_field *f, int j, struct type *type,
905
                int offset)
906
{
907
  register value_ptr v;
908
  register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
909
  struct symbol *sym;
910
 
911
  sym = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
912
                       0, VAR_NAMESPACE, 0, NULL);
913
  if (!sym)
914
    return NULL;
915
/*
916
   error ("Internal error: could not find physical method named %s",
917
   TYPE_FN_FIELD_PHYSNAME (f, j));
918
 */
919
 
920
  v = allocate_value (ftype);
921
  VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
922
  VALUE_TYPE (v) = ftype;
923
 
924
  if (arg1p)
925
    {
926
      if (type != VALUE_TYPE (*arg1p))
927
        *arg1p = value_ind (value_cast (lookup_pointer_type (type),
928
                                        value_addr (*arg1p)));
929
 
930
      /* Move the `this' pointer according to the offset.
931
         VALUE_OFFSET (*arg1p) += offset;
932
       */
933
    }
934
 
935
  return v;
936
}
937
 
938
/* ARG is a pointer to an object we know to be at least
939
   a DTYPE.  BTYPE is the most derived basetype that has
940
   already been searched (and need not be searched again).
941
   After looking at the vtables between BTYPE and DTYPE,
942
   return the most derived type we find.  The caller must
943
   be satisfied when the return value == DTYPE.
944
 
945
   FIXME-tiemann: should work with dossier entries as well.
946
   NOTICE - djb: I see no good reason at all to keep this function now that
947
   we have RTTI support. It's used in literally one place, and it's
948
   hard to keep this function up to date when it's purpose is served
949
   by value_rtti_type efficiently.
950
   Consider it gone for 5.1. */
951
 
952
static value_ptr
953
value_headof (value_ptr in_arg, struct type *btype, struct type *dtype)
954
{
955
  /* First collect the vtables we must look at for this object.  */
956
  value_ptr arg, vtbl;
957
  struct symbol *sym;
958
  char *demangled_name;
959
  struct minimal_symbol *msymbol;
960
 
961
  btype = TYPE_VPTR_BASETYPE (dtype);
962
  CHECK_TYPEDEF (btype);
963
  arg = in_arg;
964
  if (btype != dtype)
965
      arg = value_cast (lookup_pointer_type (btype), arg);
966
  if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF)
967
      {
968
          /*
969
           * Copy the value, but change the type from (T&) to (T*).
970
           * We keep the same location information, which is efficient,
971
           * and allows &(&X) to get the location containing the reference.
972
           */
973
          arg = value_copy (arg);
974
          VALUE_TYPE (arg) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg)));
975
      }
976
  if (VALUE_ADDRESS(value_field (value_ind(arg), TYPE_VPTR_FIELDNO (btype)))==0)
977
      return arg;
978
 
979
  vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype)));
980
  /* Turn vtable into typeinfo function */
981
  VALUE_OFFSET(vtbl)+=4;
982
 
983
  msymbol = lookup_minimal_symbol_by_pc ( value_as_pointer(value_ind(vtbl)) );
984
  if (msymbol == NULL
985
      || (demangled_name = SYMBOL_NAME (msymbol)) == NULL)
986
      {
987
          /* If we expected to find a vtable, but did not, let the user
988
             know that we aren't happy, but don't throw an error.
989
             FIXME: there has to be a better way to do this.  */
990
          struct type *error_type = (struct type *) xmalloc (sizeof (struct type));
991
          memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type));
992
          TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *"));
993
          VALUE_TYPE (in_arg) = error_type;
994
          return in_arg;
995
      }
996
  demangled_name = cplus_demangle(demangled_name,DMGL_ANSI);
997
  *(strchr (demangled_name, ' ')) = '\0';
998
 
999
  sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0);
1000
  if (sym == NULL)
1001
      error ("could not find type declaration for `%s'", demangled_name);
1002
 
1003
  arg = in_arg;
1004
  VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym));
1005
  return arg;
1006
}
1007
 
1008
/* ARG is a pointer object of type TYPE.  If TYPE has virtual
1009
   function tables, probe ARG's tables (including the vtables
1010
   of its baseclasses) to figure out the most derived type that ARG
1011
   could actually be a pointer to.  */
1012
 
1013
value_ptr
1014
value_from_vtable_info (value_ptr arg, struct type *type)
1015
{
1016
  /* Take care of preliminaries.  */
1017
  if (TYPE_VPTR_FIELDNO (type) < 0)
1018
    fill_in_vptr_fieldno (type);
1019
  if (TYPE_VPTR_FIELDNO (type) < 0)
1020
    return 0;
1021
 
1022
  return value_headof (arg, 0, type);
1023
}
1024
 
1025
/* Return true if the INDEXth field of TYPE is a virtual baseclass
1026
   pointer which is for the base class whose type is BASECLASS.  */
1027
 
1028
static int
1029
vb_match (struct type *type, int index, struct type *basetype)
1030
{
1031
  struct type *fieldtype;
1032
  char *name = TYPE_FIELD_NAME (type, index);
1033
  char *field_class_name = NULL;
1034
 
1035
  if (*name != '_')
1036
    return 0;
1037
  /* gcc 2.4 uses _vb$.  */
1038
  if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3]))
1039
    field_class_name = name + 4;
1040
  /* gcc 2.5 will use __vb_.  */
1041
  if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_')
1042
    field_class_name = name + 5;
1043
 
1044
  if (field_class_name == NULL)
1045
    /* This field is not a virtual base class pointer.  */
1046
    return 0;
1047
 
1048
  /* It's a virtual baseclass pointer, now we just need to find out whether
1049
     it is for this baseclass.  */
1050
  fieldtype = TYPE_FIELD_TYPE (type, index);
1051
  if (fieldtype == NULL
1052
      || TYPE_CODE (fieldtype) != TYPE_CODE_PTR)
1053
    /* "Can't happen".  */
1054
    return 0;
1055
 
1056
  /* What we check for is that either the types are equal (needed for
1057
     nameless types) or have the same name.  This is ugly, and a more
1058
     elegant solution should be devised (which would probably just push
1059
     the ugliness into symbol reading unless we change the stabs format).  */
1060
  if (TYPE_TARGET_TYPE (fieldtype) == basetype)
1061
    return 1;
1062
 
1063
  if (TYPE_NAME (basetype) != NULL
1064
      && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL
1065
      && STREQ (TYPE_NAME (basetype),
1066
                TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))))
1067
    return 1;
1068
  return 0;
1069
}
1070
 
1071
/* Compute the offset of the baseclass which is
1072
   the INDEXth baseclass of class TYPE,
1073
   for value at VALADDR (in host) at ADDRESS (in target).
1074
   The result is the offset of the baseclass value relative
1075
   to (the address of)(ARG) + OFFSET.
1076
 
1077
   -1 is returned on error. */
1078
 
1079
int
1080
baseclass_offset (struct type *type, int index, char *valaddr,
1081
                  CORE_ADDR address)
1082
{
1083
  struct type *basetype = TYPE_BASECLASS (type, index);
1084
 
1085
  if (BASETYPE_VIA_VIRTUAL (type, index))
1086
    {
1087
      /* Must hunt for the pointer to this virtual baseclass.  */
1088
      register int i, len = TYPE_NFIELDS (type);
1089
      register int n_baseclasses = TYPE_N_BASECLASSES (type);
1090
 
1091
      /* First look for the virtual baseclass pointer
1092
         in the fields.  */
1093
      for (i = n_baseclasses; i < len; i++)
1094
        {
1095
          if (vb_match (type, i, basetype))
1096
            {
1097
              CORE_ADDR addr
1098
              = unpack_pointer (TYPE_FIELD_TYPE (type, i),
1099
                                valaddr + (TYPE_FIELD_BITPOS (type, i) / 8));
1100
 
1101
              return addr - (LONGEST) address;
1102
            }
1103
        }
1104
      /* Not in the fields, so try looking through the baseclasses.  */
1105
      for (i = index + 1; i < n_baseclasses; i++)
1106
        {
1107
          int boffset =
1108
          baseclass_offset (type, i, valaddr, address);
1109
          if (boffset)
1110
            return boffset;
1111
        }
1112
      /* Not found.  */
1113
      return -1;
1114
    }
1115
 
1116
  /* Baseclass is easily computed.  */
1117
  return TYPE_BASECLASS_BITPOS (type, index) / 8;
1118
}
1119
 
1120
/* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
1121
   VALADDR.
1122
 
1123
   Extracting bits depends on endianness of the machine.  Compute the
1124
   number of least significant bits to discard.  For big endian machines,
1125
   we compute the total number of bits in the anonymous object, subtract
1126
   off the bit count from the MSB of the object to the MSB of the
1127
   bitfield, then the size of the bitfield, which leaves the LSB discard
1128
   count.  For little endian machines, the discard count is simply the
1129
   number of bits from the LSB of the anonymous object to the LSB of the
1130
   bitfield.
1131
 
1132
   If the field is signed, we also do sign extension. */
1133
 
1134
LONGEST
1135
unpack_field_as_long (struct type *type, char *valaddr, int fieldno)
1136
{
1137
  ULONGEST val;
1138
  ULONGEST valmask;
1139
  int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
1140
  int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
1141
  int lsbcount;
1142
  struct type *field_type;
1143
 
1144
  val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val));
1145
  field_type = TYPE_FIELD_TYPE (type, fieldno);
1146
  CHECK_TYPEDEF (field_type);
1147
 
1148
  /* Extract bits.  See comment above. */
1149
 
1150
  if (BITS_BIG_ENDIAN)
1151
    lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize);
1152
  else
1153
    lsbcount = (bitpos % 8);
1154
  val >>= lsbcount;
1155
 
1156
  /* If the field does not entirely fill a LONGEST, then zero the sign bits.
1157
     If the field is signed, and is negative, then sign extend. */
1158
 
1159
  if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
1160
    {
1161
      valmask = (((ULONGEST) 1) << bitsize) - 1;
1162
      val &= valmask;
1163
      if (!TYPE_UNSIGNED (field_type))
1164
        {
1165
          if (val & (valmask ^ (valmask >> 1)))
1166
            {
1167
              val |= ~valmask;
1168
            }
1169
        }
1170
    }
1171
  return (val);
1172
}
1173
 
1174
/* Modify the value of a bitfield.  ADDR points to a block of memory in
1175
   target byte order; the bitfield starts in the byte pointed to.  FIELDVAL
1176
   is the desired value of the field, in host byte order.  BITPOS and BITSIZE
1177
   indicate which bits (in target bit order) comprise the bitfield.  */
1178
 
1179
void
1180
modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize)
1181
{
1182
  LONGEST oword;
1183
 
1184
  /* If a negative fieldval fits in the field in question, chop
1185
     off the sign extension bits.  */
1186
  if (bitsize < (8 * (int) sizeof (fieldval))
1187
      && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0)
1188
    fieldval = fieldval & ((1 << bitsize) - 1);
1189
 
1190
  /* Warn if value is too big to fit in the field in question.  */
1191
  if (bitsize < (8 * (int) sizeof (fieldval))
1192
      && 0 != (fieldval & ~((1 << bitsize) - 1)))
1193
    {
1194
      /* FIXME: would like to include fieldval in the message, but
1195
         we don't have a sprintf_longest.  */
1196
      warning ("Value does not fit in %d bits.", bitsize);
1197
 
1198
      /* Truncate it, otherwise adjoining fields may be corrupted.  */
1199
      fieldval = fieldval & ((1 << bitsize) - 1);
1200
    }
1201
 
1202
  oword = extract_signed_integer (addr, sizeof oword);
1203
 
1204
  /* Shifting for bit field depends on endianness of the target machine.  */
1205
  if (BITS_BIG_ENDIAN)
1206
    bitpos = sizeof (oword) * 8 - bitpos - bitsize;
1207
 
1208
  /* Mask out old value, while avoiding shifts >= size of oword */
1209
  if (bitsize < 8 * (int) sizeof (oword))
1210
    oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos);
1211
  else
1212
    oword &= ~((~(ULONGEST) 0) << bitpos);
1213
  oword |= fieldval << bitpos;
1214
 
1215
  store_signed_integer (addr, sizeof oword, oword);
1216
}
1217
 
1218
/* Convert C numbers into newly allocated values */
1219
 
1220
value_ptr
1221
value_from_longest (struct type *type, register LONGEST num)
1222
{
1223
  register value_ptr val = allocate_value (type);
1224
  register enum type_code code;
1225
  register int len;
1226
retry:
1227
  code = TYPE_CODE (type);
1228
  len = TYPE_LENGTH (type);
1229
 
1230
  switch (code)
1231
    {
1232
    case TYPE_CODE_TYPEDEF:
1233
      type = check_typedef (type);
1234
      goto retry;
1235
    case TYPE_CODE_INT:
1236
    case TYPE_CODE_CHAR:
1237
    case TYPE_CODE_ENUM:
1238
    case TYPE_CODE_BOOL:
1239
    case TYPE_CODE_RANGE:
1240
      store_signed_integer (VALUE_CONTENTS_RAW (val), len, num);
1241
      break;
1242
 
1243
    case TYPE_CODE_REF:
1244
    case TYPE_CODE_PTR:
1245
      store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num);
1246
      break;
1247
 
1248
    default:
1249
      error ("Unexpected type (%d) encountered for integer constant.", code);
1250
    }
1251
  return val;
1252
}
1253
 
1254
 
1255
/* Create a value representing a pointer of type TYPE to the address
1256
   ADDR.  */
1257
value_ptr
1258
value_from_pointer (struct type *type, CORE_ADDR addr)
1259
{
1260
  value_ptr val = allocate_value (type);
1261
  store_typed_address (VALUE_CONTENTS_RAW (val), type, addr);
1262
  return val;
1263
}
1264
 
1265
 
1266
/* Create a value for a string constant to be stored locally
1267
   (not in the inferior's memory space, but in GDB memory).
1268
   This is analogous to value_from_longest, which also does not
1269
   use inferior memory.  String shall NOT contain embedded nulls.  */
1270
 
1271
value_ptr
1272
value_from_string (char *ptr)
1273
{
1274
  value_ptr val;
1275
  int len = strlen (ptr);
1276
  int lowbound = current_language->string_lower_bound;
1277
  struct type *rangetype =
1278
  create_range_type ((struct type *) NULL,
1279
                     builtin_type_int,
1280
                     lowbound, len + lowbound - 1);
1281
  struct type *stringtype =
1282
  create_array_type ((struct type *) NULL,
1283
                     *current_language->string_char_type,
1284
                     rangetype);
1285
 
1286
  val = allocate_value (stringtype);
1287
  memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
1288
  return val;
1289
}
1290
 
1291
value_ptr
1292
value_from_double (struct type *type, DOUBLEST num)
1293
{
1294
  register value_ptr val = allocate_value (type);
1295
  struct type *base_type = check_typedef (type);
1296
  register enum type_code code = TYPE_CODE (base_type);
1297
  register int len = TYPE_LENGTH (base_type);
1298
 
1299
  if (code == TYPE_CODE_FLT)
1300
    {
1301
      store_floating (VALUE_CONTENTS_RAW (val), len, num);
1302
    }
1303
  else
1304
    error ("Unexpected type encountered for floating constant.");
1305
 
1306
  return val;
1307
}
1308
 
1309
/* Deal with the value that is "about to be returned".  */
1310
 
1311
/* Return the value that a function returning now
1312
   would be returning to its caller, assuming its type is VALTYPE.
1313
   RETBUF is where we look for what ought to be the contents
1314
   of the registers (in raw form).  This is because it is often
1315
   desirable to restore old values to those registers
1316
   after saving the contents of interest, and then call
1317
   this function using the saved values.
1318
   struct_return is non-zero when the function in question is
1319
   using the structure return conventions on the machine in question;
1320
 
1321
   means returning pointer to where structure is vs. returning value). */
1322
 
1323
/* ARGSUSED */
1324
value_ptr
1325
value_being_returned (struct type *valtype, char *retbuf, int struct_return)
1326
{
1327
  register value_ptr val;
1328
  CORE_ADDR addr;
1329
 
1330
  /* If this is not defined, just use EXTRACT_RETURN_VALUE instead.  */
1331
  if (EXTRACT_STRUCT_VALUE_ADDRESS_P ())
1332
    if (struct_return)
1333
      {
1334
        addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf);
1335
        if (!addr)
1336
          error ("Function return value unknown");
1337
        return value_at (valtype, addr, NULL);
1338
      }
1339
 
1340
  val = allocate_value (valtype);
1341
  CHECK_TYPEDEF (valtype);
1342
  EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val));
1343
 
1344
  return val;
1345
}
1346
 
1347
/* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
1348
   EXTRACT_RETURN_VALUE?  GCC_P is true if compiled with gcc
1349
   and TYPE is the type (which is known to be struct, union or array).
1350
 
1351
   On most machines, the struct convention is used unless we are
1352
   using gcc and the type is of a special size.  */
1353
/* As of about 31 Mar 93, GCC was changed to be compatible with the
1354
   native compiler.  GCC 2.3.3 was the last release that did it the
1355
   old way.  Since gcc2_compiled was not changed, we have no
1356
   way to correctly win in all cases, so we just do the right thing
1357
   for gcc1 and for gcc2 after this change.  Thus it loses for gcc
1358
   2.0-2.3.3.  This is somewhat unfortunate, but changing gcc2_compiled
1359
   would cause more chaos than dealing with some struct returns being
1360
   handled wrong.  */
1361
 
1362
int
1363
generic_use_struct_convention (int gcc_p, struct type *value_type)
1364
{
1365
  return !((gcc_p == 1)
1366
           && (TYPE_LENGTH (value_type) == 1
1367
               || TYPE_LENGTH (value_type) == 2
1368
               || TYPE_LENGTH (value_type) == 4
1369
               || TYPE_LENGTH (value_type) == 8));
1370
}
1371
 
1372
#ifndef USE_STRUCT_CONVENTION
1373
#define USE_STRUCT_CONVENTION(gcc_p,type) generic_use_struct_convention (gcc_p, type)
1374
#endif
1375
 
1376
 
1377
/* Return true if the function specified is using the structure returning
1378
   convention on this machine to return arguments, or 0 if it is using
1379
   the value returning convention.  FUNCTION is the value representing
1380
   the function, FUNCADDR is the address of the function, and VALUE_TYPE
1381
   is the type returned by the function.  GCC_P is nonzero if compiled
1382
   with GCC.  */
1383
 
1384
/* ARGSUSED */
1385
int
1386
using_struct_return (value_ptr function, CORE_ADDR funcaddr,
1387
                     struct type *value_type, int gcc_p)
1388
{
1389
  register enum type_code code = TYPE_CODE (value_type);
1390
 
1391
  if (code == TYPE_CODE_ERROR)
1392
    error ("Function return type unknown.");
1393
 
1394
  if (code == TYPE_CODE_STRUCT
1395
      || code == TYPE_CODE_UNION
1396
      || code == TYPE_CODE_ARRAY
1397
      || RETURN_VALUE_ON_STACK (value_type))
1398
    return USE_STRUCT_CONVENTION (gcc_p, value_type);
1399
 
1400
  return 0;
1401
}
1402
 
1403
/* Store VAL so it will be returned if a function returns now.
1404
   Does not verify that VAL's type matches what the current
1405
   function wants to return.  */
1406
 
1407
void
1408
set_return_value (value_ptr val)
1409
{
1410
  struct type *type = check_typedef (VALUE_TYPE (val));
1411
  register enum type_code code = TYPE_CODE (type);
1412
 
1413
  if (code == TYPE_CODE_ERROR)
1414
    error ("Function return type unknown.");
1415
 
1416
  if (code == TYPE_CODE_STRUCT
1417
      || code == TYPE_CODE_UNION)       /* FIXME, implement struct return.  */
1418
    error ("GDB does not support specifying a struct or union return value.");
1419
 
1420
  STORE_RETURN_VALUE (type, VALUE_CONTENTS (val));
1421
}
1422
 
1423
void
1424
_initialize_values (void)
1425
{
1426
  add_cmd ("convenience", no_class, show_convenience,
1427
           "Debugger convenience (\"$foo\") variables.\n\
1428
These variables are created when you assign them values;\n\
1429
thus, \"print $foo=1\" gives \"$foo\" the value 1.  Values may be any type.\n\n\
1430
A few convenience variables are given values automatically:\n\
1431
\"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
1432
\"$__\" holds the contents of the last address examined with \"x\".",
1433
           &showlist);
1434
 
1435
  add_cmd ("values", no_class, show_values,
1436
           "Elements of value history around item number IDX (or last ten).",
1437
           &showlist);
1438
}

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