Commit | Line | Data |
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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
1bac305b | 2 | |
f23631e4 | 3 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, |
990a07ab AC |
4 | 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005 Free |
5 | Software Foundation, Inc. | |
c906108c | 6 | |
c5aa993b | 7 | This file is part of GDB. |
c906108c | 8 | |
c5aa993b JM |
9 | This program is free software; you can redistribute it and/or modify |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
c906108c | 13 | |
c5aa993b JM |
14 | This program is distributed in the hope that it will be useful, |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
c906108c | 18 | |
c5aa993b JM |
19 | You should have received a copy of the GNU General Public License |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
23 | |
24 | #include "defs.h" | |
25 | #include "gdb_string.h" | |
26 | #include "symtab.h" | |
27 | #include "gdbtypes.h" | |
28 | #include "value.h" | |
29 | #include "gdbcore.h" | |
c906108c SS |
30 | #include "command.h" |
31 | #include "gdbcmd.h" | |
32 | #include "target.h" | |
33 | #include "language.h" | |
34 | #include "scm-lang.h" | |
35 | #include "demangle.h" | |
d16aafd8 | 36 | #include "doublest.h" |
5ae326fa | 37 | #include "gdb_assert.h" |
36160dc4 | 38 | #include "regcache.h" |
fe898f56 | 39 | #include "block.h" |
c906108c SS |
40 | |
41 | /* Prototypes for exported functions. */ | |
42 | ||
a14ed312 | 43 | void _initialize_values (void); |
c906108c SS |
44 | |
45 | /* Prototypes for local functions. */ | |
46 | ||
a14ed312 | 47 | static void show_values (char *, int); |
c906108c | 48 | |
a14ed312 | 49 | static void show_convenience (char *, int); |
c906108c | 50 | |
c906108c SS |
51 | |
52 | /* The value-history records all the values printed | |
53 | by print commands during this session. Each chunk | |
54 | records 60 consecutive values. The first chunk on | |
55 | the chain records the most recent values. | |
56 | The total number of values is in value_history_count. */ | |
57 | ||
58 | #define VALUE_HISTORY_CHUNK 60 | |
59 | ||
60 | struct value_history_chunk | |
c5aa993b JM |
61 | { |
62 | struct value_history_chunk *next; | |
f23631e4 | 63 | struct value *values[VALUE_HISTORY_CHUNK]; |
c5aa993b | 64 | }; |
c906108c SS |
65 | |
66 | /* Chain of chunks now in use. */ | |
67 | ||
68 | static struct value_history_chunk *value_history_chain; | |
69 | ||
70 | static int value_history_count; /* Abs number of last entry stored */ | |
71 | \f | |
72 | /* List of all value objects currently allocated | |
73 | (except for those released by calls to release_value) | |
74 | This is so they can be freed after each command. */ | |
75 | ||
f23631e4 | 76 | static struct value *all_values; |
c906108c SS |
77 | |
78 | /* Allocate a value that has the correct length for type TYPE. */ | |
79 | ||
f23631e4 | 80 | struct value * |
fba45db2 | 81 | allocate_value (struct type *type) |
c906108c | 82 | { |
f23631e4 | 83 | struct value *val; |
c906108c SS |
84 | struct type *atype = check_typedef (type); |
85 | ||
5b90c7b5 | 86 | val = (struct value *) xzalloc (sizeof (struct value) + TYPE_LENGTH (atype)); |
df407dfe | 87 | val->next = all_values; |
c906108c | 88 | all_values = val; |
df407dfe | 89 | val->type = type; |
4754a64e | 90 | val->enclosing_type = type; |
c906108c SS |
91 | VALUE_LVAL (val) = not_lval; |
92 | VALUE_ADDRESS (val) = 0; | |
1df6926e | 93 | VALUE_FRAME_ID (val) = null_frame_id; |
df407dfe AC |
94 | val->offset = 0; |
95 | val->bitpos = 0; | |
96 | val->bitsize = 0; | |
9ee8fc9d | 97 | VALUE_REGNUM (val) = -1; |
d69fe07e | 98 | val->lazy = 0; |
feb13ab0 | 99 | val->optimized_out = 0; |
13c3b5f5 | 100 | val->embedded_offset = 0; |
c906108c SS |
101 | VALUE_POINTED_TO_OFFSET (val) = 0; |
102 | val->modifiable = 1; | |
103 | return val; | |
104 | } | |
105 | ||
106 | /* Allocate a value that has the correct length | |
107 | for COUNT repetitions type TYPE. */ | |
108 | ||
f23631e4 | 109 | struct value * |
fba45db2 | 110 | allocate_repeat_value (struct type *type, int count) |
c906108c | 111 | { |
c5aa993b | 112 | int low_bound = current_language->string_lower_bound; /* ??? */ |
c906108c SS |
113 | /* FIXME-type-allocation: need a way to free this type when we are |
114 | done with it. */ | |
115 | struct type *range_type | |
c5aa993b JM |
116 | = create_range_type ((struct type *) NULL, builtin_type_int, |
117 | low_bound, count + low_bound - 1); | |
c906108c SS |
118 | /* FIXME-type-allocation: need a way to free this type when we are |
119 | done with it. */ | |
120 | return allocate_value (create_array_type ((struct type *) NULL, | |
121 | type, range_type)); | |
122 | } | |
123 | ||
df407dfe AC |
124 | /* Accessor methods. */ |
125 | ||
126 | struct type * | |
127 | value_type (struct value *value) | |
128 | { | |
129 | return value->type; | |
130 | } | |
131 | ||
132 | int | |
133 | value_offset (struct value *value) | |
134 | { | |
135 | return value->offset; | |
136 | } | |
137 | ||
138 | int | |
139 | value_bitpos (struct value *value) | |
140 | { | |
141 | return value->bitpos; | |
142 | } | |
143 | ||
144 | int | |
145 | value_bitsize (struct value *value) | |
146 | { | |
147 | return value->bitsize; | |
148 | } | |
149 | ||
990a07ab AC |
150 | bfd_byte * |
151 | value_contents_raw (struct value *value) | |
152 | { | |
153 | return value->aligner.contents + value->embedded_offset; | |
154 | } | |
155 | ||
156 | bfd_byte * | |
157 | value_contents_all_raw (struct value *value) | |
158 | { | |
159 | return value->aligner.contents; | |
160 | } | |
161 | ||
4754a64e AC |
162 | struct type * |
163 | value_enclosing_type (struct value *value) | |
164 | { | |
165 | return value->enclosing_type; | |
166 | } | |
167 | ||
46615f07 AC |
168 | const bfd_byte * |
169 | value_contents_all (struct value *value) | |
170 | { | |
171 | if (value->lazy) | |
172 | value_fetch_lazy (value); | |
173 | return value->aligner.contents; | |
174 | } | |
175 | ||
d69fe07e AC |
176 | int |
177 | value_lazy (struct value *value) | |
178 | { | |
179 | return value->lazy; | |
180 | } | |
181 | ||
dfa52d88 AC |
182 | void |
183 | set_value_lazy (struct value *value, int val) | |
184 | { | |
185 | value->lazy = val; | |
186 | } | |
187 | ||
0fd88904 AC |
188 | const bfd_byte * |
189 | value_contents (struct value *value) | |
190 | { | |
191 | return value_contents_writeable (value); | |
192 | } | |
193 | ||
194 | bfd_byte * | |
195 | value_contents_writeable (struct value *value) | |
196 | { | |
197 | if (value->lazy) | |
198 | value_fetch_lazy (value); | |
199 | return value->aligner.contents; | |
200 | } | |
201 | ||
feb13ab0 AC |
202 | int |
203 | value_optimized_out (struct value *value) | |
204 | { | |
205 | return value->optimized_out; | |
206 | } | |
207 | ||
208 | void | |
209 | set_value_optimized_out (struct value *value, int val) | |
210 | { | |
211 | value->optimized_out = val; | |
212 | } | |
13c3b5f5 AC |
213 | |
214 | int | |
215 | value_embedded_offset (struct value *value) | |
216 | { | |
217 | return value->embedded_offset; | |
218 | } | |
219 | ||
220 | void | |
221 | set_value_embedded_offset (struct value *value, int val) | |
222 | { | |
223 | value->embedded_offset = val; | |
224 | } | |
990a07ab | 225 | \f |
c906108c SS |
226 | /* Return a mark in the value chain. All values allocated after the |
227 | mark is obtained (except for those released) are subject to being freed | |
228 | if a subsequent value_free_to_mark is passed the mark. */ | |
f23631e4 | 229 | struct value * |
fba45db2 | 230 | value_mark (void) |
c906108c SS |
231 | { |
232 | return all_values; | |
233 | } | |
234 | ||
235 | /* Free all values allocated since MARK was obtained by value_mark | |
236 | (except for those released). */ | |
237 | void | |
f23631e4 | 238 | value_free_to_mark (struct value *mark) |
c906108c | 239 | { |
f23631e4 AC |
240 | struct value *val; |
241 | struct value *next; | |
c906108c SS |
242 | |
243 | for (val = all_values; val && val != mark; val = next) | |
244 | { | |
df407dfe | 245 | next = val->next; |
c906108c SS |
246 | value_free (val); |
247 | } | |
248 | all_values = val; | |
249 | } | |
250 | ||
251 | /* Free all the values that have been allocated (except for those released). | |
252 | Called after each command, successful or not. */ | |
253 | ||
254 | void | |
fba45db2 | 255 | free_all_values (void) |
c906108c | 256 | { |
f23631e4 AC |
257 | struct value *val; |
258 | struct value *next; | |
c906108c SS |
259 | |
260 | for (val = all_values; val; val = next) | |
261 | { | |
df407dfe | 262 | next = val->next; |
c906108c SS |
263 | value_free (val); |
264 | } | |
265 | ||
266 | all_values = 0; | |
267 | } | |
268 | ||
269 | /* Remove VAL from the chain all_values | |
270 | so it will not be freed automatically. */ | |
271 | ||
272 | void | |
f23631e4 | 273 | release_value (struct value *val) |
c906108c | 274 | { |
f23631e4 | 275 | struct value *v; |
c906108c SS |
276 | |
277 | if (all_values == val) | |
278 | { | |
279 | all_values = val->next; | |
280 | return; | |
281 | } | |
282 | ||
283 | for (v = all_values; v; v = v->next) | |
284 | { | |
285 | if (v->next == val) | |
286 | { | |
287 | v->next = val->next; | |
288 | break; | |
289 | } | |
290 | } | |
291 | } | |
292 | ||
293 | /* Release all values up to mark */ | |
f23631e4 AC |
294 | struct value * |
295 | value_release_to_mark (struct value *mark) | |
c906108c | 296 | { |
f23631e4 AC |
297 | struct value *val; |
298 | struct value *next; | |
c906108c | 299 | |
df407dfe AC |
300 | for (val = next = all_values; next; next = next->next) |
301 | if (next->next == mark) | |
c906108c | 302 | { |
df407dfe AC |
303 | all_values = next->next; |
304 | next->next = NULL; | |
c906108c SS |
305 | return val; |
306 | } | |
307 | all_values = 0; | |
308 | return val; | |
309 | } | |
310 | ||
311 | /* Return a copy of the value ARG. | |
312 | It contains the same contents, for same memory address, | |
313 | but it's a different block of storage. */ | |
314 | ||
f23631e4 AC |
315 | struct value * |
316 | value_copy (struct value *arg) | |
c906108c | 317 | { |
4754a64e | 318 | struct type *encl_type = value_enclosing_type (arg); |
f23631e4 | 319 | struct value *val = allocate_value (encl_type); |
df407dfe | 320 | val->type = arg->type; |
c906108c SS |
321 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
322 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); | |
df407dfe AC |
323 | val->offset = arg->offset; |
324 | val->bitpos = arg->bitpos; | |
325 | val->bitsize = arg->bitsize; | |
1df6926e | 326 | VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
9ee8fc9d | 327 | VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
d69fe07e | 328 | val->lazy = arg->lazy; |
feb13ab0 | 329 | val->optimized_out = arg->optimized_out; |
13c3b5f5 | 330 | val->embedded_offset = value_embedded_offset (arg); |
c906108c | 331 | VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg); |
c906108c | 332 | val->modifiable = arg->modifiable; |
d69fe07e | 333 | if (!value_lazy (val)) |
c906108c | 334 | { |
990a07ab | 335 | memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
4754a64e | 336 | TYPE_LENGTH (value_enclosing_type (arg))); |
c906108c SS |
337 | |
338 | } | |
339 | return val; | |
340 | } | |
341 | \f | |
342 | /* Access to the value history. */ | |
343 | ||
344 | /* Record a new value in the value history. | |
345 | Returns the absolute history index of the entry. | |
346 | Result of -1 indicates the value was not saved; otherwise it is the | |
347 | value history index of this new item. */ | |
348 | ||
349 | int | |
f23631e4 | 350 | record_latest_value (struct value *val) |
c906108c SS |
351 | { |
352 | int i; | |
353 | ||
354 | /* We don't want this value to have anything to do with the inferior anymore. | |
355 | In particular, "set $1 = 50" should not affect the variable from which | |
356 | the value was taken, and fast watchpoints should be able to assume that | |
357 | a value on the value history never changes. */ | |
d69fe07e | 358 | if (value_lazy (val)) |
c906108c SS |
359 | value_fetch_lazy (val); |
360 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
361 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
362 | but the current contents of that location. c'est la vie... */ | |
363 | val->modifiable = 0; | |
364 | release_value (val); | |
365 | ||
366 | /* Here we treat value_history_count as origin-zero | |
367 | and applying to the value being stored now. */ | |
368 | ||
369 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
370 | if (i == 0) | |
371 | { | |
f23631e4 | 372 | struct value_history_chunk *new |
c5aa993b JM |
373 | = (struct value_history_chunk *) |
374 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
375 | memset (new->values, 0, sizeof new->values); |
376 | new->next = value_history_chain; | |
377 | value_history_chain = new; | |
378 | } | |
379 | ||
380 | value_history_chain->values[i] = val; | |
381 | ||
382 | /* Now we regard value_history_count as origin-one | |
383 | and applying to the value just stored. */ | |
384 | ||
385 | return ++value_history_count; | |
386 | } | |
387 | ||
388 | /* Return a copy of the value in the history with sequence number NUM. */ | |
389 | ||
f23631e4 | 390 | struct value * |
fba45db2 | 391 | access_value_history (int num) |
c906108c | 392 | { |
f23631e4 | 393 | struct value_history_chunk *chunk; |
52f0bd74 AC |
394 | int i; |
395 | int absnum = num; | |
c906108c SS |
396 | |
397 | if (absnum <= 0) | |
398 | absnum += value_history_count; | |
399 | ||
400 | if (absnum <= 0) | |
401 | { | |
402 | if (num == 0) | |
403 | error ("The history is empty."); | |
404 | else if (num == 1) | |
405 | error ("There is only one value in the history."); | |
406 | else | |
407 | error ("History does not go back to $$%d.", -num); | |
408 | } | |
409 | if (absnum > value_history_count) | |
410 | error ("History has not yet reached $%d.", absnum); | |
411 | ||
412 | absnum--; | |
413 | ||
414 | /* Now absnum is always absolute and origin zero. */ | |
415 | ||
416 | chunk = value_history_chain; | |
417 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
418 | i > 0; i--) | |
419 | chunk = chunk->next; | |
420 | ||
421 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
422 | } | |
423 | ||
424 | /* Clear the value history entirely. | |
425 | Must be done when new symbol tables are loaded, | |
426 | because the type pointers become invalid. */ | |
427 | ||
428 | void | |
fba45db2 | 429 | clear_value_history (void) |
c906108c | 430 | { |
f23631e4 | 431 | struct value_history_chunk *next; |
52f0bd74 | 432 | int i; |
f23631e4 | 433 | struct value *val; |
c906108c SS |
434 | |
435 | while (value_history_chain) | |
436 | { | |
437 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
438 | if ((val = value_history_chain->values[i]) != NULL) | |
b8c9b27d | 439 | xfree (val); |
c906108c | 440 | next = value_history_chain->next; |
b8c9b27d | 441 | xfree (value_history_chain); |
c906108c SS |
442 | value_history_chain = next; |
443 | } | |
444 | value_history_count = 0; | |
445 | } | |
446 | ||
447 | static void | |
fba45db2 | 448 | show_values (char *num_exp, int from_tty) |
c906108c | 449 | { |
52f0bd74 | 450 | int i; |
f23631e4 | 451 | struct value *val; |
c906108c SS |
452 | static int num = 1; |
453 | ||
454 | if (num_exp) | |
455 | { | |
c5aa993b JM |
456 | /* "info history +" should print from the stored position. |
457 | "info history <exp>" should print around value number <exp>. */ | |
c906108c | 458 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 459 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
460 | } |
461 | else | |
462 | { | |
463 | /* "info history" means print the last 10 values. */ | |
464 | num = value_history_count - 9; | |
465 | } | |
466 | ||
467 | if (num <= 0) | |
468 | num = 1; | |
469 | ||
470 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
471 | { | |
472 | val = access_value_history (i); | |
473 | printf_filtered ("$%d = ", i); | |
474 | value_print (val, gdb_stdout, 0, Val_pretty_default); | |
475 | printf_filtered ("\n"); | |
476 | } | |
477 | ||
478 | /* The next "info history +" should start after what we just printed. */ | |
479 | num += 10; | |
480 | ||
481 | /* Hitting just return after this command should do the same thing as | |
482 | "info history +". If num_exp is null, this is unnecessary, since | |
483 | "info history +" is not useful after "info history". */ | |
484 | if (from_tty && num_exp) | |
485 | { | |
486 | num_exp[0] = '+'; | |
487 | num_exp[1] = '\0'; | |
488 | } | |
489 | } | |
490 | \f | |
491 | /* Internal variables. These are variables within the debugger | |
492 | that hold values assigned by debugger commands. | |
493 | The user refers to them with a '$' prefix | |
494 | that does not appear in the variable names stored internally. */ | |
495 | ||
496 | static struct internalvar *internalvars; | |
497 | ||
498 | /* Look up an internal variable with name NAME. NAME should not | |
499 | normally include a dollar sign. | |
500 | ||
501 | If the specified internal variable does not exist, | |
502 | one is created, with a void value. */ | |
503 | ||
504 | struct internalvar * | |
fba45db2 | 505 | lookup_internalvar (char *name) |
c906108c | 506 | { |
52f0bd74 | 507 | struct internalvar *var; |
c906108c SS |
508 | |
509 | for (var = internalvars; var; var = var->next) | |
5cb316ef | 510 | if (strcmp (var->name, name) == 0) |
c906108c SS |
511 | return var; |
512 | ||
513 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); | |
514 | var->name = concat (name, NULL); | |
515 | var->value = allocate_value (builtin_type_void); | |
516 | release_value (var->value); | |
517 | var->next = internalvars; | |
518 | internalvars = var; | |
519 | return var; | |
520 | } | |
521 | ||
f23631e4 | 522 | struct value * |
fba45db2 | 523 | value_of_internalvar (struct internalvar *var) |
c906108c | 524 | { |
f23631e4 | 525 | struct value *val; |
c906108c | 526 | |
c906108c | 527 | val = value_copy (var->value); |
d69fe07e | 528 | if (value_lazy (val)) |
c906108c SS |
529 | value_fetch_lazy (val); |
530 | VALUE_LVAL (val) = lval_internalvar; | |
531 | VALUE_INTERNALVAR (val) = var; | |
532 | return val; | |
533 | } | |
534 | ||
535 | void | |
fba45db2 | 536 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
f23631e4 | 537 | int bitsize, struct value *newval) |
c906108c | 538 | { |
0fd88904 | 539 | bfd_byte *addr = value_contents_writeable (var->value) + offset; |
c906108c | 540 | |
c906108c SS |
541 | if (bitsize) |
542 | modify_field (addr, value_as_long (newval), | |
543 | bitpos, bitsize); | |
544 | else | |
0fd88904 | 545 | memcpy (addr, value_contents (newval), TYPE_LENGTH (value_type (newval))); |
c906108c SS |
546 | } |
547 | ||
548 | void | |
f23631e4 | 549 | set_internalvar (struct internalvar *var, struct value *val) |
c906108c | 550 | { |
f23631e4 | 551 | struct value *newval; |
c906108c | 552 | |
c906108c SS |
553 | newval = value_copy (val); |
554 | newval->modifiable = 1; | |
555 | ||
556 | /* Force the value to be fetched from the target now, to avoid problems | |
557 | later when this internalvar is referenced and the target is gone or | |
558 | has changed. */ | |
d69fe07e | 559 | if (value_lazy (newval)) |
c906108c SS |
560 | value_fetch_lazy (newval); |
561 | ||
562 | /* Begin code which must not call error(). If var->value points to | |
563 | something free'd, an error() obviously leaves a dangling pointer. | |
564 | But we also get a danling pointer if var->value points to | |
565 | something in the value chain (i.e., before release_value is | |
566 | called), because after the error free_all_values will get called before | |
567 | long. */ | |
b8c9b27d | 568 | xfree (var->value); |
c906108c SS |
569 | var->value = newval; |
570 | release_value (newval); | |
571 | /* End code which must not call error(). */ | |
572 | } | |
573 | ||
574 | char * | |
fba45db2 | 575 | internalvar_name (struct internalvar *var) |
c906108c SS |
576 | { |
577 | return var->name; | |
578 | } | |
579 | ||
580 | /* Free all internalvars. Done when new symtabs are loaded, | |
581 | because that makes the values invalid. */ | |
582 | ||
583 | void | |
fba45db2 | 584 | clear_internalvars (void) |
c906108c | 585 | { |
52f0bd74 | 586 | struct internalvar *var; |
c906108c SS |
587 | |
588 | while (internalvars) | |
589 | { | |
590 | var = internalvars; | |
591 | internalvars = var->next; | |
b8c9b27d KB |
592 | xfree (var->name); |
593 | xfree (var->value); | |
594 | xfree (var); | |
c906108c SS |
595 | } |
596 | } | |
597 | ||
598 | static void | |
fba45db2 | 599 | show_convenience (char *ignore, int from_tty) |
c906108c | 600 | { |
52f0bd74 | 601 | struct internalvar *var; |
c906108c SS |
602 | int varseen = 0; |
603 | ||
604 | for (var = internalvars; var; var = var->next) | |
605 | { | |
c906108c SS |
606 | if (!varseen) |
607 | { | |
608 | varseen = 1; | |
609 | } | |
610 | printf_filtered ("$%s = ", var->name); | |
611 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); | |
612 | printf_filtered ("\n"); | |
613 | } | |
614 | if (!varseen) | |
615 | printf_unfiltered ("No debugger convenience variables now defined.\n\ | |
616 | Convenience variables have names starting with \"$\";\n\ | |
617 | use \"set\" as in \"set $foo = 5\" to define them.\n"); | |
618 | } | |
619 | \f | |
620 | /* Extract a value as a C number (either long or double). | |
621 | Knows how to convert fixed values to double, or | |
622 | floating values to long. | |
623 | Does not deallocate the value. */ | |
624 | ||
625 | LONGEST | |
f23631e4 | 626 | value_as_long (struct value *val) |
c906108c SS |
627 | { |
628 | /* This coerces arrays and functions, which is necessary (e.g. | |
629 | in disassemble_command). It also dereferences references, which | |
630 | I suspect is the most logical thing to do. */ | |
994b9211 | 631 | val = coerce_array (val); |
0fd88904 | 632 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
633 | } |
634 | ||
635 | DOUBLEST | |
f23631e4 | 636 | value_as_double (struct value *val) |
c906108c SS |
637 | { |
638 | DOUBLEST foo; | |
639 | int inv; | |
c5aa993b | 640 | |
0fd88904 | 641 | foo = unpack_double (value_type (val), value_contents (val), &inv); |
c906108c SS |
642 | if (inv) |
643 | error ("Invalid floating value found in program."); | |
644 | return foo; | |
645 | } | |
4478b372 JB |
646 | /* Extract a value as a C pointer. Does not deallocate the value. |
647 | Note that val's type may not actually be a pointer; value_as_long | |
648 | handles all the cases. */ | |
c906108c | 649 | CORE_ADDR |
f23631e4 | 650 | value_as_address (struct value *val) |
c906108c SS |
651 | { |
652 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
653 | whether we want this to be true eventually. */ | |
654 | #if 0 | |
655 | /* ADDR_BITS_REMOVE is wrong if we are being called for a | |
656 | non-address (e.g. argument to "signal", "info break", etc.), or | |
657 | for pointers to char, in which the low bits *are* significant. */ | |
c5aa993b | 658 | return ADDR_BITS_REMOVE (value_as_long (val)); |
c906108c | 659 | #else |
f312f057 JB |
660 | |
661 | /* There are several targets (IA-64, PowerPC, and others) which | |
662 | don't represent pointers to functions as simply the address of | |
663 | the function's entry point. For example, on the IA-64, a | |
664 | function pointer points to a two-word descriptor, generated by | |
665 | the linker, which contains the function's entry point, and the | |
666 | value the IA-64 "global pointer" register should have --- to | |
667 | support position-independent code. The linker generates | |
668 | descriptors only for those functions whose addresses are taken. | |
669 | ||
670 | On such targets, it's difficult for GDB to convert an arbitrary | |
671 | function address into a function pointer; it has to either find | |
672 | an existing descriptor for that function, or call malloc and | |
673 | build its own. On some targets, it is impossible for GDB to | |
674 | build a descriptor at all: the descriptor must contain a jump | |
675 | instruction; data memory cannot be executed; and code memory | |
676 | cannot be modified. | |
677 | ||
678 | Upon entry to this function, if VAL is a value of type `function' | |
679 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
680 | VALUE_ADDRESS (val) is the address of the function. This is what | |
681 | you'll get if you evaluate an expression like `main'. The call | |
682 | to COERCE_ARRAY below actually does all the usual unary | |
683 | conversions, which includes converting values of type `function' | |
684 | to `pointer to function'. This is the challenging conversion | |
685 | discussed above. Then, `unpack_long' will convert that pointer | |
686 | back into an address. | |
687 | ||
688 | So, suppose the user types `disassemble foo' on an architecture | |
689 | with a strange function pointer representation, on which GDB | |
690 | cannot build its own descriptors, and suppose further that `foo' | |
691 | has no linker-built descriptor. The address->pointer conversion | |
692 | will signal an error and prevent the command from running, even | |
693 | though the next step would have been to convert the pointer | |
694 | directly back into the same address. | |
695 | ||
696 | The following shortcut avoids this whole mess. If VAL is a | |
697 | function, just return its address directly. */ | |
df407dfe AC |
698 | if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
699 | || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) | |
f312f057 JB |
700 | return VALUE_ADDRESS (val); |
701 | ||
994b9211 | 702 | val = coerce_array (val); |
fc0c74b1 AC |
703 | |
704 | /* Some architectures (e.g. Harvard), map instruction and data | |
705 | addresses onto a single large unified address space. For | |
706 | instance: An architecture may consider a large integer in the | |
707 | range 0x10000000 .. 0x1000ffff to already represent a data | |
708 | addresses (hence not need a pointer to address conversion) while | |
709 | a small integer would still need to be converted integer to | |
710 | pointer to address. Just assume such architectures handle all | |
711 | integer conversions in a single function. */ | |
712 | ||
713 | /* JimB writes: | |
714 | ||
715 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
716 | must admonish GDB hackers to make sure its behavior matches the | |
717 | compiler's, whenever possible. | |
718 | ||
719 | In general, I think GDB should evaluate expressions the same way | |
720 | the compiler does. When the user copies an expression out of | |
721 | their source code and hands it to a `print' command, they should | |
722 | get the same value the compiler would have computed. Any | |
723 | deviation from this rule can cause major confusion and annoyance, | |
724 | and needs to be justified carefully. In other words, GDB doesn't | |
725 | really have the freedom to do these conversions in clever and | |
726 | useful ways. | |
727 | ||
728 | AndrewC pointed out that users aren't complaining about how GDB | |
729 | casts integers to pointers; they are complaining that they can't | |
730 | take an address from a disassembly listing and give it to `x/i'. | |
731 | This is certainly important. | |
732 | ||
79dd2d24 | 733 | Adding an architecture method like integer_to_address() certainly |
fc0c74b1 AC |
734 | makes it possible for GDB to "get it right" in all circumstances |
735 | --- the target has complete control over how things get done, so | |
736 | people can Do The Right Thing for their target without breaking | |
737 | anyone else. The standard doesn't specify how integers get | |
738 | converted to pointers; usually, the ABI doesn't either, but | |
739 | ABI-specific code is a more reasonable place to handle it. */ | |
740 | ||
df407dfe AC |
741 | if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
742 | && TYPE_CODE (value_type (val)) != TYPE_CODE_REF | |
79dd2d24 AC |
743 | && gdbarch_integer_to_address_p (current_gdbarch)) |
744 | return gdbarch_integer_to_address (current_gdbarch, value_type (val), | |
0fd88904 | 745 | value_contents (val)); |
fc0c74b1 | 746 | |
0fd88904 | 747 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
748 | #endif |
749 | } | |
750 | \f | |
751 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
752 | as a long, or as a double, assuming the raw data is described | |
753 | by type TYPE. Knows how to convert different sizes of values | |
754 | and can convert between fixed and floating point. We don't assume | |
755 | any alignment for the raw data. Return value is in host byte order. | |
756 | ||
757 | If you want functions and arrays to be coerced to pointers, and | |
758 | references to be dereferenced, call value_as_long() instead. | |
759 | ||
760 | C++: It is assumed that the front-end has taken care of | |
761 | all matters concerning pointers to members. A pointer | |
762 | to member which reaches here is considered to be equivalent | |
763 | to an INT (or some size). After all, it is only an offset. */ | |
764 | ||
765 | LONGEST | |
66140c26 | 766 | unpack_long (struct type *type, const char *valaddr) |
c906108c | 767 | { |
52f0bd74 AC |
768 | enum type_code code = TYPE_CODE (type); |
769 | int len = TYPE_LENGTH (type); | |
770 | int nosign = TYPE_UNSIGNED (type); | |
c906108c SS |
771 | |
772 | if (current_language->la_language == language_scm | |
773 | && is_scmvalue_type (type)) | |
774 | return scm_unpack (type, valaddr, TYPE_CODE_INT); | |
775 | ||
776 | switch (code) | |
777 | { | |
778 | case TYPE_CODE_TYPEDEF: | |
779 | return unpack_long (check_typedef (type), valaddr); | |
780 | case TYPE_CODE_ENUM: | |
781 | case TYPE_CODE_BOOL: | |
782 | case TYPE_CODE_INT: | |
783 | case TYPE_CODE_CHAR: | |
784 | case TYPE_CODE_RANGE: | |
785 | if (nosign) | |
786 | return extract_unsigned_integer (valaddr, len); | |
787 | else | |
788 | return extract_signed_integer (valaddr, len); | |
789 | ||
790 | case TYPE_CODE_FLT: | |
96d2f608 | 791 | return extract_typed_floating (valaddr, type); |
c906108c SS |
792 | |
793 | case TYPE_CODE_PTR: | |
794 | case TYPE_CODE_REF: | |
795 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 796 | whether we want this to be true eventually. */ |
4478b372 | 797 | return extract_typed_address (valaddr, type); |
c906108c SS |
798 | |
799 | case TYPE_CODE_MEMBER: | |
800 | error ("not implemented: member types in unpack_long"); | |
801 | ||
802 | default: | |
803 | error ("Value can't be converted to integer."); | |
804 | } | |
c5aa993b | 805 | return 0; /* Placate lint. */ |
c906108c SS |
806 | } |
807 | ||
808 | /* Return a double value from the specified type and address. | |
809 | INVP points to an int which is set to 0 for valid value, | |
810 | 1 for invalid value (bad float format). In either case, | |
811 | the returned double is OK to use. Argument is in target | |
812 | format, result is in host format. */ | |
813 | ||
814 | DOUBLEST | |
66140c26 | 815 | unpack_double (struct type *type, const char *valaddr, int *invp) |
c906108c SS |
816 | { |
817 | enum type_code code; | |
818 | int len; | |
819 | int nosign; | |
820 | ||
821 | *invp = 0; /* Assume valid. */ | |
822 | CHECK_TYPEDEF (type); | |
823 | code = TYPE_CODE (type); | |
824 | len = TYPE_LENGTH (type); | |
825 | nosign = TYPE_UNSIGNED (type); | |
826 | if (code == TYPE_CODE_FLT) | |
827 | { | |
75bc7ddf AC |
828 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
829 | floating-point value was valid (using the macro | |
830 | INVALID_FLOAT). That test/macro have been removed. | |
831 | ||
832 | It turns out that only the VAX defined this macro and then | |
833 | only in a non-portable way. Fixing the portability problem | |
834 | wouldn't help since the VAX floating-point code is also badly | |
835 | bit-rotten. The target needs to add definitions for the | |
836 | methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these | |
837 | exactly describe the target floating-point format. The | |
838 | problem here is that the corresponding floatformat_vax_f and | |
839 | floatformat_vax_d values these methods should be set to are | |
840 | also not defined either. Oops! | |
841 | ||
842 | Hopefully someone will add both the missing floatformat | |
ac79b88b DJ |
843 | definitions and the new cases for floatformat_is_valid (). */ |
844 | ||
845 | if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) | |
846 | { | |
847 | *invp = 1; | |
848 | return 0.0; | |
849 | } | |
850 | ||
96d2f608 | 851 | return extract_typed_floating (valaddr, type); |
c906108c SS |
852 | } |
853 | else if (nosign) | |
854 | { | |
855 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 856 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
857 | } |
858 | else | |
859 | { | |
860 | /* Signed -- we are OK with unpack_long. */ | |
861 | return unpack_long (type, valaddr); | |
862 | } | |
863 | } | |
864 | ||
865 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
866 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
867 | We don't assume any alignment for the raw data. Return value is in | |
868 | host byte order. | |
869 | ||
870 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 871 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
872 | |
873 | C++: It is assumed that the front-end has taken care of | |
874 | all matters concerning pointers to members. A pointer | |
875 | to member which reaches here is considered to be equivalent | |
876 | to an INT (or some size). After all, it is only an offset. */ | |
877 | ||
878 | CORE_ADDR | |
66140c26 | 879 | unpack_pointer (struct type *type, const char *valaddr) |
c906108c SS |
880 | { |
881 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
882 | whether we want this to be true eventually. */ | |
883 | return unpack_long (type, valaddr); | |
884 | } | |
4478b372 | 885 | |
c906108c | 886 | \f |
2c2738a0 DC |
887 | /* Get the value of the FIELDN'th field (which must be static) of |
888 | TYPE. Return NULL if the field doesn't exist or has been | |
889 | optimized out. */ | |
c906108c | 890 | |
f23631e4 | 891 | struct value * |
fba45db2 | 892 | value_static_field (struct type *type, int fieldno) |
c906108c | 893 | { |
948e66d9 DJ |
894 | struct value *retval; |
895 | ||
c906108c SS |
896 | if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) |
897 | { | |
948e66d9 | 898 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 899 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
c906108c SS |
900 | } |
901 | else | |
902 | { | |
903 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
176620f1 | 904 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0, NULL); |
948e66d9 | 905 | if (sym == NULL) |
c906108c SS |
906 | { |
907 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
908 | as non-debuggable symbols */ |
909 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
910 | if (!msym) |
911 | return NULL; | |
912 | else | |
c5aa993b | 913 | { |
948e66d9 | 914 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 915 | SYMBOL_VALUE_ADDRESS (msym)); |
c906108c SS |
916 | } |
917 | } | |
918 | else | |
919 | { | |
948e66d9 DJ |
920 | /* SYM should never have a SYMBOL_CLASS which will require |
921 | read_var_value to use the FRAME parameter. */ | |
922 | if (symbol_read_needs_frame (sym)) | |
923 | warning ("static field's value depends on the current " | |
924 | "frame - bad debug info?"); | |
925 | retval = read_var_value (sym, NULL); | |
2b127877 | 926 | } |
948e66d9 DJ |
927 | if (retval && VALUE_LVAL (retval) == lval_memory) |
928 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), | |
929 | VALUE_ADDRESS (retval)); | |
c906108c | 930 | } |
948e66d9 | 931 | return retval; |
c906108c SS |
932 | } |
933 | ||
2b127877 DB |
934 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
935 | You have to be careful here, since the size of the data area for the value | |
936 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
937 | than the old enclosing type, you have to allocate more space for the data. | |
938 | The return value is a pointer to the new version of this value structure. */ | |
939 | ||
f23631e4 AC |
940 | struct value * |
941 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) | |
2b127877 | 942 | { |
4754a64e | 943 | if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (value_enclosing_type (val))) |
2b127877 | 944 | { |
4754a64e | 945 | val->enclosing_type = new_encl_type; |
2b127877 DB |
946 | return val; |
947 | } | |
948 | else | |
949 | { | |
f23631e4 AC |
950 | struct value *new_val; |
951 | struct value *prev; | |
2b127877 | 952 | |
f23631e4 | 953 | new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); |
cc303028 | 954 | |
4754a64e | 955 | new_val->enclosing_type = new_encl_type; |
cc303028 | 956 | |
2b127877 DB |
957 | /* We have to make sure this ends up in the same place in the value |
958 | chain as the original copy, so it's clean-up behavior is the same. | |
959 | If the value has been released, this is a waste of time, but there | |
960 | is no way to tell that in advance, so... */ | |
961 | ||
962 | if (val != all_values) | |
963 | { | |
964 | for (prev = all_values; prev != NULL; prev = prev->next) | |
965 | { | |
966 | if (prev->next == val) | |
967 | { | |
968 | prev->next = new_val; | |
969 | break; | |
970 | } | |
971 | } | |
972 | } | |
973 | ||
974 | return new_val; | |
975 | } | |
976 | } | |
977 | ||
c906108c SS |
978 | /* Given a value ARG1 (offset by OFFSET bytes) |
979 | of a struct or union type ARG_TYPE, | |
980 | extract and return the value of one of its (non-static) fields. | |
981 | FIELDNO says which field. */ | |
982 | ||
f23631e4 AC |
983 | struct value * |
984 | value_primitive_field (struct value *arg1, int offset, | |
aa1ee363 | 985 | int fieldno, struct type *arg_type) |
c906108c | 986 | { |
f23631e4 | 987 | struct value *v; |
52f0bd74 | 988 | struct type *type; |
c906108c SS |
989 | |
990 | CHECK_TYPEDEF (arg_type); | |
991 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
992 | ||
993 | /* Handle packed fields */ | |
994 | ||
995 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
996 | { | |
997 | v = value_from_longest (type, | |
998 | unpack_field_as_long (arg_type, | |
0fd88904 | 999 | value_contents (arg1) |
c5aa993b | 1000 | + offset, |
c906108c | 1001 | fieldno)); |
df407dfe AC |
1002 | v->bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; |
1003 | v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
1004 | v->offset = value_offset (arg1) + offset | |
2e70b7b9 | 1005 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
c906108c SS |
1006 | } |
1007 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
1008 | { | |
1009 | /* This field is actually a base subobject, so preserve the | |
1010 | entire object's contents for later references to virtual | |
1011 | bases, etc. */ | |
4754a64e | 1012 | v = allocate_value (value_enclosing_type (arg1)); |
df407dfe | 1013 | v->type = type; |
d69fe07e | 1014 | if (value_lazy (arg1)) |
dfa52d88 | 1015 | set_value_lazy (v, 1); |
c906108c | 1016 | else |
990a07ab | 1017 | memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1), |
4754a64e | 1018 | TYPE_LENGTH (value_enclosing_type (arg1))); |
df407dfe | 1019 | v->offset = value_offset (arg1); |
13c3b5f5 AC |
1020 | v->embedded_offset = (offset + value_embedded_offset (arg1) |
1021 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8); | |
c906108c SS |
1022 | } |
1023 | else | |
1024 | { | |
1025 | /* Plain old data member */ | |
1026 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
1027 | v = allocate_value (type); | |
d69fe07e | 1028 | if (value_lazy (arg1)) |
dfa52d88 | 1029 | set_value_lazy (v, 1); |
c906108c | 1030 | else |
990a07ab AC |
1031 | memcpy (value_contents_raw (v), |
1032 | value_contents_raw (arg1) + offset, | |
c906108c | 1033 | TYPE_LENGTH (type)); |
df407dfe | 1034 | v->offset = (value_offset (arg1) + offset |
13c3b5f5 | 1035 | + value_embedded_offset (arg1)); |
c906108c SS |
1036 | } |
1037 | VALUE_LVAL (v) = VALUE_LVAL (arg1); | |
1038 | if (VALUE_LVAL (arg1) == lval_internalvar) | |
1039 | VALUE_LVAL (v) = lval_internalvar_component; | |
1040 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); | |
9ee8fc9d | 1041 | VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
0c16dd26 | 1042 | VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
c906108c | 1043 | /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
c5aa993b | 1044 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ |
c906108c SS |
1045 | return v; |
1046 | } | |
1047 | ||
1048 | /* Given a value ARG1 of a struct or union type, | |
1049 | extract and return the value of one of its (non-static) fields. | |
1050 | FIELDNO says which field. */ | |
1051 | ||
f23631e4 | 1052 | struct value * |
aa1ee363 | 1053 | value_field (struct value *arg1, int fieldno) |
c906108c | 1054 | { |
df407dfe | 1055 | return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
c906108c SS |
1056 | } |
1057 | ||
1058 | /* Return a non-virtual function as a value. | |
1059 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
1060 | J is an index into F which provides the desired method. |
1061 | ||
1062 | We only use the symbol for its address, so be happy with either a | |
1063 | full symbol or a minimal symbol. | |
1064 | */ | |
c906108c | 1065 | |
f23631e4 AC |
1066 | struct value * |
1067 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, | |
fba45db2 | 1068 | int offset) |
c906108c | 1069 | { |
f23631e4 | 1070 | struct value *v; |
52f0bd74 | 1071 | struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
0478d61c | 1072 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 1073 | struct symbol *sym; |
0478d61c | 1074 | struct minimal_symbol *msym; |
c906108c | 1075 | |
176620f1 | 1076 | sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0, NULL); |
5ae326fa | 1077 | if (sym != NULL) |
0478d61c | 1078 | { |
5ae326fa AC |
1079 | msym = NULL; |
1080 | } | |
1081 | else | |
1082 | { | |
1083 | gdb_assert (sym == NULL); | |
0478d61c | 1084 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
1085 | if (msym == NULL) |
1086 | return NULL; | |
0478d61c FF |
1087 | } |
1088 | ||
c906108c | 1089 | v = allocate_value (ftype); |
0478d61c FF |
1090 | if (sym) |
1091 | { | |
1092 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
1093 | } | |
1094 | else | |
1095 | { | |
1096 | VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); | |
1097 | } | |
c906108c SS |
1098 | |
1099 | if (arg1p) | |
c5aa993b | 1100 | { |
df407dfe | 1101 | if (type != value_type (*arg1p)) |
c5aa993b JM |
1102 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
1103 | value_addr (*arg1p))); | |
1104 | ||
070ad9f0 | 1105 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1106 | VALUE_OFFSET (*arg1p) += offset; |
1107 | */ | |
c906108c SS |
1108 | } |
1109 | ||
1110 | return v; | |
1111 | } | |
1112 | ||
c906108c SS |
1113 | \f |
1114 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1115 | VALADDR. | |
1116 | ||
1117 | Extracting bits depends on endianness of the machine. Compute the | |
1118 | number of least significant bits to discard. For big endian machines, | |
1119 | we compute the total number of bits in the anonymous object, subtract | |
1120 | off the bit count from the MSB of the object to the MSB of the | |
1121 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1122 | count. For little endian machines, the discard count is simply the | |
1123 | number of bits from the LSB of the anonymous object to the LSB of the | |
1124 | bitfield. | |
1125 | ||
1126 | If the field is signed, we also do sign extension. */ | |
1127 | ||
1128 | LONGEST | |
66140c26 | 1129 | unpack_field_as_long (struct type *type, const char *valaddr, int fieldno) |
c906108c SS |
1130 | { |
1131 | ULONGEST val; | |
1132 | ULONGEST valmask; | |
1133 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1134 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1135 | int lsbcount; | |
1136 | struct type *field_type; | |
1137 | ||
1138 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1139 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1140 | CHECK_TYPEDEF (field_type); | |
1141 | ||
1142 | /* Extract bits. See comment above. */ | |
1143 | ||
1144 | if (BITS_BIG_ENDIAN) | |
1145 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); | |
1146 | else | |
1147 | lsbcount = (bitpos % 8); | |
1148 | val >>= lsbcount; | |
1149 | ||
1150 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1151 | If the field is signed, and is negative, then sign extend. */ | |
1152 | ||
1153 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1154 | { | |
1155 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1156 | val &= valmask; | |
1157 | if (!TYPE_UNSIGNED (field_type)) | |
1158 | { | |
1159 | if (val & (valmask ^ (valmask >> 1))) | |
1160 | { | |
1161 | val |= ~valmask; | |
1162 | } | |
1163 | } | |
1164 | } | |
1165 | return (val); | |
1166 | } | |
1167 | ||
1168 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1169 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1170 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
f4e88c8e PH |
1171 | indicate which bits (in target bit order) comprise the bitfield. |
1172 | Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and | |
1173 | 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ | |
c906108c SS |
1174 | |
1175 | void | |
fba45db2 | 1176 | modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c | 1177 | { |
f4e88c8e PH |
1178 | ULONGEST oword; |
1179 | ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); | |
c906108c SS |
1180 | |
1181 | /* If a negative fieldval fits in the field in question, chop | |
1182 | off the sign extension bits. */ | |
f4e88c8e PH |
1183 | if ((~fieldval & ~(mask >> 1)) == 0) |
1184 | fieldval &= mask; | |
c906108c SS |
1185 | |
1186 | /* Warn if value is too big to fit in the field in question. */ | |
f4e88c8e | 1187 | if (0 != (fieldval & ~mask)) |
c906108c SS |
1188 | { |
1189 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1190 | we don't have a sprintf_longest. */ |
c906108c SS |
1191 | warning ("Value does not fit in %d bits.", bitsize); |
1192 | ||
1193 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
f4e88c8e | 1194 | fieldval &= mask; |
c906108c SS |
1195 | } |
1196 | ||
f4e88c8e | 1197 | oword = extract_unsigned_integer (addr, sizeof oword); |
c906108c SS |
1198 | |
1199 | /* Shifting for bit field depends on endianness of the target machine. */ | |
1200 | if (BITS_BIG_ENDIAN) | |
1201 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; | |
1202 | ||
f4e88c8e | 1203 | oword &= ~(mask << bitpos); |
c906108c SS |
1204 | oword |= fieldval << bitpos; |
1205 | ||
f4e88c8e | 1206 | store_unsigned_integer (addr, sizeof oword, oword); |
c906108c SS |
1207 | } |
1208 | \f | |
1209 | /* Convert C numbers into newly allocated values */ | |
1210 | ||
f23631e4 | 1211 | struct value * |
aa1ee363 | 1212 | value_from_longest (struct type *type, LONGEST num) |
c906108c | 1213 | { |
f23631e4 | 1214 | struct value *val = allocate_value (type); |
52f0bd74 AC |
1215 | enum type_code code; |
1216 | int len; | |
c5aa993b | 1217 | retry: |
c906108c SS |
1218 | code = TYPE_CODE (type); |
1219 | len = TYPE_LENGTH (type); | |
1220 | ||
1221 | switch (code) | |
1222 | { | |
1223 | case TYPE_CODE_TYPEDEF: | |
1224 | type = check_typedef (type); | |
1225 | goto retry; | |
1226 | case TYPE_CODE_INT: | |
1227 | case TYPE_CODE_CHAR: | |
1228 | case TYPE_CODE_ENUM: | |
1229 | case TYPE_CODE_BOOL: | |
1230 | case TYPE_CODE_RANGE: | |
990a07ab | 1231 | store_signed_integer (value_contents_raw (val), len, num); |
c906108c | 1232 | break; |
c5aa993b | 1233 | |
c906108c SS |
1234 | case TYPE_CODE_REF: |
1235 | case TYPE_CODE_PTR: | |
990a07ab | 1236 | store_typed_address (value_contents_raw (val), type, (CORE_ADDR) num); |
c906108c | 1237 | break; |
c5aa993b | 1238 | |
c906108c SS |
1239 | default: |
1240 | error ("Unexpected type (%d) encountered for integer constant.", code); | |
1241 | } | |
1242 | return val; | |
1243 | } | |
1244 | ||
4478b372 JB |
1245 | |
1246 | /* Create a value representing a pointer of type TYPE to the address | |
1247 | ADDR. */ | |
f23631e4 | 1248 | struct value * |
4478b372 JB |
1249 | value_from_pointer (struct type *type, CORE_ADDR addr) |
1250 | { | |
f23631e4 | 1251 | struct value *val = allocate_value (type); |
990a07ab | 1252 | store_typed_address (value_contents_raw (val), type, addr); |
4478b372 JB |
1253 | return val; |
1254 | } | |
1255 | ||
1256 | ||
0f71a2f6 | 1257 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1258 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1259 | This is analogous to value_from_longest, which also does not |
1260 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1261 | ||
f23631e4 | 1262 | struct value * |
fba45db2 | 1263 | value_from_string (char *ptr) |
0f71a2f6 | 1264 | { |
f23631e4 | 1265 | struct value *val; |
c5aa993b | 1266 | int len = strlen (ptr); |
0f71a2f6 | 1267 | int lowbound = current_language->string_lower_bound; |
f290d38e AC |
1268 | struct type *string_char_type; |
1269 | struct type *rangetype; | |
1270 | struct type *stringtype; | |
1271 | ||
1272 | rangetype = create_range_type ((struct type *) NULL, | |
1273 | builtin_type_int, | |
1274 | lowbound, len + lowbound - 1); | |
1275 | string_char_type = language_string_char_type (current_language, | |
1276 | current_gdbarch); | |
1277 | stringtype = create_array_type ((struct type *) NULL, | |
1278 | string_char_type, | |
1279 | rangetype); | |
0f71a2f6 | 1280 | val = allocate_value (stringtype); |
990a07ab | 1281 | memcpy (value_contents_raw (val), ptr, len); |
0f71a2f6 JM |
1282 | return val; |
1283 | } | |
1284 | ||
f23631e4 | 1285 | struct value * |
fba45db2 | 1286 | value_from_double (struct type *type, DOUBLEST num) |
c906108c | 1287 | { |
f23631e4 | 1288 | struct value *val = allocate_value (type); |
c906108c | 1289 | struct type *base_type = check_typedef (type); |
52f0bd74 AC |
1290 | enum type_code code = TYPE_CODE (base_type); |
1291 | int len = TYPE_LENGTH (base_type); | |
c906108c SS |
1292 | |
1293 | if (code == TYPE_CODE_FLT) | |
1294 | { | |
990a07ab | 1295 | store_typed_floating (value_contents_raw (val), base_type, num); |
c906108c SS |
1296 | } |
1297 | else | |
1298 | error ("Unexpected type encountered for floating constant."); | |
1299 | ||
1300 | return val; | |
1301 | } | |
994b9211 AC |
1302 | |
1303 | struct value * | |
1304 | coerce_ref (struct value *arg) | |
1305 | { | |
df407dfe | 1306 | struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
994b9211 AC |
1307 | if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) |
1308 | arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), | |
df407dfe | 1309 | unpack_pointer (value_type (arg), |
0fd88904 | 1310 | value_contents (arg))); |
994b9211 AC |
1311 | return arg; |
1312 | } | |
1313 | ||
1314 | struct value * | |
1315 | coerce_array (struct value *arg) | |
1316 | { | |
1317 | arg = coerce_ref (arg); | |
1318 | if (current_language->c_style_arrays | |
df407dfe | 1319 | && TYPE_CODE (value_type (arg)) == TYPE_CODE_ARRAY) |
994b9211 | 1320 | arg = value_coerce_array (arg); |
df407dfe | 1321 | if (TYPE_CODE (value_type (arg)) == TYPE_CODE_FUNC) |
994b9211 AC |
1322 | arg = value_coerce_function (arg); |
1323 | return arg; | |
1324 | } | |
1325 | ||
1326 | struct value * | |
1327 | coerce_number (struct value *arg) | |
1328 | { | |
1329 | arg = coerce_array (arg); | |
1330 | arg = coerce_enum (arg); | |
1331 | return arg; | |
1332 | } | |
1333 | ||
1334 | struct value * | |
1335 | coerce_enum (struct value *arg) | |
1336 | { | |
df407dfe | 1337 | if (TYPE_CODE (check_typedef (value_type (arg))) == TYPE_CODE_ENUM) |
994b9211 AC |
1338 | arg = value_cast (builtin_type_unsigned_int, arg); |
1339 | return arg; | |
1340 | } | |
c906108c | 1341 | \f |
c906108c | 1342 | |
74055713 AC |
1343 | /* Should we use DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS instead of |
1344 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc and TYPE | |
1345 | is the type (which is known to be struct, union or array). | |
c906108c SS |
1346 | |
1347 | On most machines, the struct convention is used unless we are | |
1348 | using gcc and the type is of a special size. */ | |
1349 | /* As of about 31 Mar 93, GCC was changed to be compatible with the | |
1350 | native compiler. GCC 2.3.3 was the last release that did it the | |
1351 | old way. Since gcc2_compiled was not changed, we have no | |
1352 | way to correctly win in all cases, so we just do the right thing | |
1353 | for gcc1 and for gcc2 after this change. Thus it loses for gcc | |
1354 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled | |
1355 | would cause more chaos than dealing with some struct returns being | |
1356 | handled wrong. */ | |
bc87dfa0 AC |
1357 | /* NOTE: cagney/2004-06-13: Deleted check for "gcc_p". GCC 1.x is |
1358 | dead. */ | |
c906108c SS |
1359 | |
1360 | int | |
fba45db2 | 1361 | generic_use_struct_convention (int gcc_p, struct type *value_type) |
c5aa993b | 1362 | { |
bc87dfa0 AC |
1363 | return !(TYPE_LENGTH (value_type) == 1 |
1364 | || TYPE_LENGTH (value_type) == 2 | |
1365 | || TYPE_LENGTH (value_type) == 4 | |
1366 | || TYPE_LENGTH (value_type) == 8); | |
c906108c SS |
1367 | } |
1368 | ||
48436ce6 AC |
1369 | /* Return true if the function returning the specified type is using |
1370 | the convention of returning structures in memory (passing in the | |
1371 | address as a hidden first parameter). GCC_P is nonzero if compiled | |
c906108c SS |
1372 | with GCC. */ |
1373 | ||
1374 | int | |
48436ce6 | 1375 | using_struct_return (struct type *value_type, int gcc_p) |
c906108c | 1376 | { |
52f0bd74 | 1377 | enum type_code code = TYPE_CODE (value_type); |
c906108c SS |
1378 | |
1379 | if (code == TYPE_CODE_ERROR) | |
1380 | error ("Function return type unknown."); | |
1381 | ||
667e784f AC |
1382 | if (code == TYPE_CODE_VOID) |
1383 | /* A void return value is never in memory. See also corresponding | |
44e5158b | 1384 | code in "print_return_value". */ |
667e784f AC |
1385 | return 0; |
1386 | ||
92ad9cd9 AC |
1387 | /* Probe the architecture for the return-value convention. */ |
1388 | return (gdbarch_return_value (current_gdbarch, value_type, | |
1389 | NULL, NULL, NULL) | |
31db7b6c | 1390 | != RETURN_VALUE_REGISTER_CONVENTION); |
c906108c SS |
1391 | } |
1392 | ||
c906108c | 1393 | void |
fba45db2 | 1394 | _initialize_values (void) |
c906108c SS |
1395 | { |
1396 | add_cmd ("convenience", no_class, show_convenience, | |
c5aa993b | 1397 | "Debugger convenience (\"$foo\") variables.\n\ |
c906108c SS |
1398 | These variables are created when you assign them values;\n\ |
1399 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ | |
1400 | A few convenience variables are given values automatically:\n\ | |
1401 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1402 | \"$__\" holds the contents of the last address examined with \"x\".", | |
1403 | &showlist); | |
1404 | ||
1405 | add_cmd ("values", no_class, show_values, | |
1406 | "Elements of value history around item number IDX (or last ten).", | |
1407 | &showlist); | |
1408 | } |