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