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