Commit | Line | Data |
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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
f23631e4 AC |
2 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, |
3 | 1995, 1996, 1997, 1998, 1999, 2000, 2002. | |
c906108c SS |
4 | Free Software Foundation, Inc. |
5 | ||
c5aa993b | 6 | This file is part of GDB. |
c906108c | 7 | |
c5aa993b JM |
8 | This program is free software; you can redistribute it and/or modify |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
c906108c | 12 | |
c5aa993b JM |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
c906108c | 17 | |
c5aa993b JM |
18 | You should have received a copy of the GNU General Public License |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
22 | |
23 | #include "defs.h" | |
24 | #include "gdb_string.h" | |
25 | #include "symtab.h" | |
26 | #include "gdbtypes.h" | |
27 | #include "value.h" | |
28 | #include "gdbcore.h" | |
c906108c SS |
29 | #include "command.h" |
30 | #include "gdbcmd.h" | |
31 | #include "target.h" | |
32 | #include "language.h" | |
33 | #include "scm-lang.h" | |
34 | #include "demangle.h" | |
d16aafd8 | 35 | #include "doublest.h" |
5ae326fa | 36 | #include "gdb_assert.h" |
36160dc4 | 37 | #include "regcache.h" |
c906108c SS |
38 | |
39 | /* Prototypes for exported functions. */ | |
40 | ||
a14ed312 | 41 | void _initialize_values (void); |
c906108c SS |
42 | |
43 | /* Prototypes for local functions. */ | |
44 | ||
a14ed312 | 45 | static void show_values (char *, int); |
c906108c | 46 | |
a14ed312 | 47 | static void show_convenience (char *, int); |
c906108c | 48 | |
c906108c SS |
49 | |
50 | /* The value-history records all the values printed | |
51 | by print commands during this session. Each chunk | |
52 | records 60 consecutive values. The first chunk on | |
53 | the chain records the most recent values. | |
54 | The total number of values is in value_history_count. */ | |
55 | ||
56 | #define VALUE_HISTORY_CHUNK 60 | |
57 | ||
58 | struct value_history_chunk | |
c5aa993b JM |
59 | { |
60 | struct value_history_chunk *next; | |
f23631e4 | 61 | struct value *values[VALUE_HISTORY_CHUNK]; |
c5aa993b | 62 | }; |
c906108c SS |
63 | |
64 | /* Chain of chunks now in use. */ | |
65 | ||
66 | static struct value_history_chunk *value_history_chain; | |
67 | ||
68 | static int value_history_count; /* Abs number of last entry stored */ | |
69 | \f | |
70 | /* List of all value objects currently allocated | |
71 | (except for those released by calls to release_value) | |
72 | This is so they can be freed after each command. */ | |
73 | ||
f23631e4 | 74 | static struct value *all_values; |
c906108c SS |
75 | |
76 | /* Allocate a value that has the correct length for type TYPE. */ | |
77 | ||
f23631e4 | 78 | struct value * |
fba45db2 | 79 | allocate_value (struct type *type) |
c906108c | 80 | { |
f23631e4 | 81 | struct value *val; |
c906108c SS |
82 | struct type *atype = check_typedef (type); |
83 | ||
84 | val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype)); | |
85 | VALUE_NEXT (val) = all_values; | |
86 | all_values = val; | |
87 | VALUE_TYPE (val) = type; | |
88 | VALUE_ENCLOSING_TYPE (val) = type; | |
89 | VALUE_LVAL (val) = not_lval; | |
90 | VALUE_ADDRESS (val) = 0; | |
91 | VALUE_FRAME (val) = 0; | |
92 | VALUE_OFFSET (val) = 0; | |
93 | VALUE_BITPOS (val) = 0; | |
94 | VALUE_BITSIZE (val) = 0; | |
95 | VALUE_REGNO (val) = -1; | |
96 | VALUE_LAZY (val) = 0; | |
97 | VALUE_OPTIMIZED_OUT (val) = 0; | |
98 | VALUE_BFD_SECTION (val) = NULL; | |
99 | VALUE_EMBEDDED_OFFSET (val) = 0; | |
100 | VALUE_POINTED_TO_OFFSET (val) = 0; | |
101 | val->modifiable = 1; | |
102 | return val; | |
103 | } | |
104 | ||
105 | /* Allocate a value that has the correct length | |
106 | for COUNT repetitions type TYPE. */ | |
107 | ||
f23631e4 | 108 | struct value * |
fba45db2 | 109 | allocate_repeat_value (struct type *type, int count) |
c906108c | 110 | { |
c5aa993b | 111 | int low_bound = current_language->string_lower_bound; /* ??? */ |
c906108c SS |
112 | /* FIXME-type-allocation: need a way to free this type when we are |
113 | done with it. */ | |
114 | struct type *range_type | |
c5aa993b JM |
115 | = create_range_type ((struct type *) NULL, builtin_type_int, |
116 | low_bound, count + low_bound - 1); | |
c906108c SS |
117 | /* FIXME-type-allocation: need a way to free this type when we are |
118 | done with it. */ | |
119 | return allocate_value (create_array_type ((struct type *) NULL, | |
120 | type, range_type)); | |
121 | } | |
122 | ||
123 | /* Return a mark in the value chain. All values allocated after the | |
124 | mark is obtained (except for those released) are subject to being freed | |
125 | if a subsequent value_free_to_mark is passed the mark. */ | |
f23631e4 | 126 | struct value * |
fba45db2 | 127 | value_mark (void) |
c906108c SS |
128 | { |
129 | return all_values; | |
130 | } | |
131 | ||
132 | /* Free all values allocated since MARK was obtained by value_mark | |
133 | (except for those released). */ | |
134 | void | |
f23631e4 | 135 | value_free_to_mark (struct value *mark) |
c906108c | 136 | { |
f23631e4 AC |
137 | struct value *val; |
138 | struct value *next; | |
c906108c SS |
139 | |
140 | for (val = all_values; val && val != mark; val = next) | |
141 | { | |
142 | next = VALUE_NEXT (val); | |
143 | value_free (val); | |
144 | } | |
145 | all_values = val; | |
146 | } | |
147 | ||
148 | /* Free all the values that have been allocated (except for those released). | |
149 | Called after each command, successful or not. */ | |
150 | ||
151 | void | |
fba45db2 | 152 | free_all_values (void) |
c906108c | 153 | { |
f23631e4 AC |
154 | struct value *val; |
155 | struct value *next; | |
c906108c SS |
156 | |
157 | for (val = all_values; val; val = next) | |
158 | { | |
159 | next = VALUE_NEXT (val); | |
160 | value_free (val); | |
161 | } | |
162 | ||
163 | all_values = 0; | |
164 | } | |
165 | ||
166 | /* Remove VAL from the chain all_values | |
167 | so it will not be freed automatically. */ | |
168 | ||
169 | void | |
f23631e4 | 170 | release_value (struct value *val) |
c906108c | 171 | { |
f23631e4 | 172 | struct value *v; |
c906108c SS |
173 | |
174 | if (all_values == val) | |
175 | { | |
176 | all_values = val->next; | |
177 | return; | |
178 | } | |
179 | ||
180 | for (v = all_values; v; v = v->next) | |
181 | { | |
182 | if (v->next == val) | |
183 | { | |
184 | v->next = val->next; | |
185 | break; | |
186 | } | |
187 | } | |
188 | } | |
189 | ||
190 | /* Release all values up to mark */ | |
f23631e4 AC |
191 | struct value * |
192 | value_release_to_mark (struct value *mark) | |
c906108c | 193 | { |
f23631e4 AC |
194 | struct value *val; |
195 | struct value *next; | |
c906108c SS |
196 | |
197 | for (val = next = all_values; next; next = VALUE_NEXT (next)) | |
198 | if (VALUE_NEXT (next) == mark) | |
199 | { | |
200 | all_values = VALUE_NEXT (next); | |
201 | VALUE_NEXT (next) = 0; | |
202 | return val; | |
203 | } | |
204 | all_values = 0; | |
205 | return val; | |
206 | } | |
207 | ||
208 | /* Return a copy of the value ARG. | |
209 | It contains the same contents, for same memory address, | |
210 | but it's a different block of storage. */ | |
211 | ||
f23631e4 AC |
212 | struct value * |
213 | value_copy (struct value *arg) | |
c906108c SS |
214 | { |
215 | register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg); | |
f23631e4 | 216 | struct value *val = allocate_value (encl_type); |
c906108c SS |
217 | VALUE_TYPE (val) = VALUE_TYPE (arg); |
218 | VALUE_LVAL (val) = VALUE_LVAL (arg); | |
219 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); | |
220 | VALUE_OFFSET (val) = VALUE_OFFSET (arg); | |
221 | VALUE_BITPOS (val) = VALUE_BITPOS (arg); | |
222 | VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); | |
223 | VALUE_FRAME (val) = VALUE_FRAME (arg); | |
224 | VALUE_REGNO (val) = VALUE_REGNO (arg); | |
225 | VALUE_LAZY (val) = VALUE_LAZY (arg); | |
226 | VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg); | |
227 | VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg); | |
228 | VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg); | |
229 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg); | |
230 | val->modifiable = arg->modifiable; | |
231 | if (!VALUE_LAZY (val)) | |
232 | { | |
233 | memcpy (VALUE_CONTENTS_ALL_RAW (val), VALUE_CONTENTS_ALL_RAW (arg), | |
234 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg))); | |
235 | ||
236 | } | |
237 | return val; | |
238 | } | |
239 | \f | |
240 | /* Access to the value history. */ | |
241 | ||
242 | /* Record a new value in the value history. | |
243 | Returns the absolute history index of the entry. | |
244 | Result of -1 indicates the value was not saved; otherwise it is the | |
245 | value history index of this new item. */ | |
246 | ||
247 | int | |
f23631e4 | 248 | record_latest_value (struct value *val) |
c906108c SS |
249 | { |
250 | int i; | |
251 | ||
252 | /* We don't want this value to have anything to do with the inferior anymore. | |
253 | In particular, "set $1 = 50" should not affect the variable from which | |
254 | the value was taken, and fast watchpoints should be able to assume that | |
255 | a value on the value history never changes. */ | |
256 | if (VALUE_LAZY (val)) | |
257 | value_fetch_lazy (val); | |
258 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
259 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
260 | but the current contents of that location. c'est la vie... */ | |
261 | val->modifiable = 0; | |
262 | release_value (val); | |
263 | ||
264 | /* Here we treat value_history_count as origin-zero | |
265 | and applying to the value being stored now. */ | |
266 | ||
267 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
268 | if (i == 0) | |
269 | { | |
f23631e4 | 270 | struct value_history_chunk *new |
c5aa993b JM |
271 | = (struct value_history_chunk *) |
272 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
273 | memset (new->values, 0, sizeof new->values); |
274 | new->next = value_history_chain; | |
275 | value_history_chain = new; | |
276 | } | |
277 | ||
278 | value_history_chain->values[i] = val; | |
279 | ||
280 | /* Now we regard value_history_count as origin-one | |
281 | and applying to the value just stored. */ | |
282 | ||
283 | return ++value_history_count; | |
284 | } | |
285 | ||
286 | /* Return a copy of the value in the history with sequence number NUM. */ | |
287 | ||
f23631e4 | 288 | struct value * |
fba45db2 | 289 | access_value_history (int num) |
c906108c | 290 | { |
f23631e4 | 291 | struct value_history_chunk *chunk; |
c906108c SS |
292 | register int i; |
293 | register int absnum = num; | |
294 | ||
295 | if (absnum <= 0) | |
296 | absnum += value_history_count; | |
297 | ||
298 | if (absnum <= 0) | |
299 | { | |
300 | if (num == 0) | |
301 | error ("The history is empty."); | |
302 | else if (num == 1) | |
303 | error ("There is only one value in the history."); | |
304 | else | |
305 | error ("History does not go back to $$%d.", -num); | |
306 | } | |
307 | if (absnum > value_history_count) | |
308 | error ("History has not yet reached $%d.", absnum); | |
309 | ||
310 | absnum--; | |
311 | ||
312 | /* Now absnum is always absolute and origin zero. */ | |
313 | ||
314 | chunk = value_history_chain; | |
315 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
316 | i > 0; i--) | |
317 | chunk = chunk->next; | |
318 | ||
319 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
320 | } | |
321 | ||
322 | /* Clear the value history entirely. | |
323 | Must be done when new symbol tables are loaded, | |
324 | because the type pointers become invalid. */ | |
325 | ||
326 | void | |
fba45db2 | 327 | clear_value_history (void) |
c906108c | 328 | { |
f23631e4 | 329 | struct value_history_chunk *next; |
c906108c | 330 | register int i; |
f23631e4 | 331 | struct value *val; |
c906108c SS |
332 | |
333 | while (value_history_chain) | |
334 | { | |
335 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
336 | if ((val = value_history_chain->values[i]) != NULL) | |
b8c9b27d | 337 | xfree (val); |
c906108c | 338 | next = value_history_chain->next; |
b8c9b27d | 339 | xfree (value_history_chain); |
c906108c SS |
340 | value_history_chain = next; |
341 | } | |
342 | value_history_count = 0; | |
343 | } | |
344 | ||
345 | static void | |
fba45db2 | 346 | show_values (char *num_exp, int from_tty) |
c906108c SS |
347 | { |
348 | register int i; | |
f23631e4 | 349 | struct value *val; |
c906108c SS |
350 | static int num = 1; |
351 | ||
352 | if (num_exp) | |
353 | { | |
c5aa993b JM |
354 | /* "info history +" should print from the stored position. |
355 | "info history <exp>" should print around value number <exp>. */ | |
c906108c | 356 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 357 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
358 | } |
359 | else | |
360 | { | |
361 | /* "info history" means print the last 10 values. */ | |
362 | num = value_history_count - 9; | |
363 | } | |
364 | ||
365 | if (num <= 0) | |
366 | num = 1; | |
367 | ||
368 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
369 | { | |
370 | val = access_value_history (i); | |
371 | printf_filtered ("$%d = ", i); | |
372 | value_print (val, gdb_stdout, 0, Val_pretty_default); | |
373 | printf_filtered ("\n"); | |
374 | } | |
375 | ||
376 | /* The next "info history +" should start after what we just printed. */ | |
377 | num += 10; | |
378 | ||
379 | /* Hitting just return after this command should do the same thing as | |
380 | "info history +". If num_exp is null, this is unnecessary, since | |
381 | "info history +" is not useful after "info history". */ | |
382 | if (from_tty && num_exp) | |
383 | { | |
384 | num_exp[0] = '+'; | |
385 | num_exp[1] = '\0'; | |
386 | } | |
387 | } | |
388 | \f | |
389 | /* Internal variables. These are variables within the debugger | |
390 | that hold values assigned by debugger commands. | |
391 | The user refers to them with a '$' prefix | |
392 | that does not appear in the variable names stored internally. */ | |
393 | ||
394 | static struct internalvar *internalvars; | |
395 | ||
396 | /* Look up an internal variable with name NAME. NAME should not | |
397 | normally include a dollar sign. | |
398 | ||
399 | If the specified internal variable does not exist, | |
400 | one is created, with a void value. */ | |
401 | ||
402 | struct internalvar * | |
fba45db2 | 403 | lookup_internalvar (char *name) |
c906108c SS |
404 | { |
405 | register struct internalvar *var; | |
406 | ||
407 | for (var = internalvars; var; var = var->next) | |
408 | if (STREQ (var->name, name)) | |
409 | return var; | |
410 | ||
411 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); | |
412 | var->name = concat (name, NULL); | |
413 | var->value = allocate_value (builtin_type_void); | |
414 | release_value (var->value); | |
415 | var->next = internalvars; | |
416 | internalvars = var; | |
417 | return var; | |
418 | } | |
419 | ||
f23631e4 | 420 | struct value * |
fba45db2 | 421 | value_of_internalvar (struct internalvar *var) |
c906108c | 422 | { |
f23631e4 | 423 | struct value *val; |
c906108c SS |
424 | |
425 | #ifdef IS_TRAPPED_INTERNALVAR | |
426 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
427 | return VALUE_OF_TRAPPED_INTERNALVAR (var); | |
c5aa993b | 428 | #endif |
c906108c SS |
429 | |
430 | val = value_copy (var->value); | |
431 | if (VALUE_LAZY (val)) | |
432 | value_fetch_lazy (val); | |
433 | VALUE_LVAL (val) = lval_internalvar; | |
434 | VALUE_INTERNALVAR (val) = var; | |
435 | return val; | |
436 | } | |
437 | ||
438 | void | |
fba45db2 | 439 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
f23631e4 | 440 | int bitsize, struct value *newval) |
c906108c SS |
441 | { |
442 | register char *addr = VALUE_CONTENTS (var->value) + offset; | |
443 | ||
444 | #ifdef IS_TRAPPED_INTERNALVAR | |
445 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
446 | SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); | |
447 | #endif | |
448 | ||
449 | if (bitsize) | |
450 | modify_field (addr, value_as_long (newval), | |
451 | bitpos, bitsize); | |
452 | else | |
453 | memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval))); | |
454 | } | |
455 | ||
456 | void | |
f23631e4 | 457 | set_internalvar (struct internalvar *var, struct value *val) |
c906108c | 458 | { |
f23631e4 | 459 | struct value *newval; |
c906108c SS |
460 | |
461 | #ifdef IS_TRAPPED_INTERNALVAR | |
462 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
463 | SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); | |
464 | #endif | |
465 | ||
466 | newval = value_copy (val); | |
467 | newval->modifiable = 1; | |
468 | ||
469 | /* Force the value to be fetched from the target now, to avoid problems | |
470 | later when this internalvar is referenced and the target is gone or | |
471 | has changed. */ | |
472 | if (VALUE_LAZY (newval)) | |
473 | value_fetch_lazy (newval); | |
474 | ||
475 | /* Begin code which must not call error(). If var->value points to | |
476 | something free'd, an error() obviously leaves a dangling pointer. | |
477 | But we also get a danling pointer if var->value points to | |
478 | something in the value chain (i.e., before release_value is | |
479 | called), because after the error free_all_values will get called before | |
480 | long. */ | |
b8c9b27d | 481 | xfree (var->value); |
c906108c SS |
482 | var->value = newval; |
483 | release_value (newval); | |
484 | /* End code which must not call error(). */ | |
485 | } | |
486 | ||
487 | char * | |
fba45db2 | 488 | internalvar_name (struct internalvar *var) |
c906108c SS |
489 | { |
490 | return var->name; | |
491 | } | |
492 | ||
493 | /* Free all internalvars. Done when new symtabs are loaded, | |
494 | because that makes the values invalid. */ | |
495 | ||
496 | void | |
fba45db2 | 497 | clear_internalvars (void) |
c906108c SS |
498 | { |
499 | register struct internalvar *var; | |
500 | ||
501 | while (internalvars) | |
502 | { | |
503 | var = internalvars; | |
504 | internalvars = var->next; | |
b8c9b27d KB |
505 | xfree (var->name); |
506 | xfree (var->value); | |
507 | xfree (var); | |
c906108c SS |
508 | } |
509 | } | |
510 | ||
511 | static void | |
fba45db2 | 512 | show_convenience (char *ignore, int from_tty) |
c906108c SS |
513 | { |
514 | register struct internalvar *var; | |
515 | int varseen = 0; | |
516 | ||
517 | for (var = internalvars; var; var = var->next) | |
518 | { | |
519 | #ifdef IS_TRAPPED_INTERNALVAR | |
520 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
521 | continue; | |
522 | #endif | |
523 | if (!varseen) | |
524 | { | |
525 | varseen = 1; | |
526 | } | |
527 | printf_filtered ("$%s = ", var->name); | |
528 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); | |
529 | printf_filtered ("\n"); | |
530 | } | |
531 | if (!varseen) | |
532 | printf_unfiltered ("No debugger convenience variables now defined.\n\ | |
533 | Convenience variables have names starting with \"$\";\n\ | |
534 | use \"set\" as in \"set $foo = 5\" to define them.\n"); | |
535 | } | |
536 | \f | |
537 | /* Extract a value as a C number (either long or double). | |
538 | Knows how to convert fixed values to double, or | |
539 | floating values to long. | |
540 | Does not deallocate the value. */ | |
541 | ||
542 | LONGEST | |
f23631e4 | 543 | value_as_long (struct value *val) |
c906108c SS |
544 | { |
545 | /* This coerces arrays and functions, which is necessary (e.g. | |
546 | in disassemble_command). It also dereferences references, which | |
547 | I suspect is the most logical thing to do. */ | |
548 | COERCE_ARRAY (val); | |
549 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
550 | } | |
551 | ||
552 | DOUBLEST | |
f23631e4 | 553 | value_as_double (struct value *val) |
c906108c SS |
554 | { |
555 | DOUBLEST foo; | |
556 | int inv; | |
c5aa993b | 557 | |
c906108c SS |
558 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv); |
559 | if (inv) | |
560 | error ("Invalid floating value found in program."); | |
561 | return foo; | |
562 | } | |
4478b372 JB |
563 | /* Extract a value as a C pointer. Does not deallocate the value. |
564 | Note that val's type may not actually be a pointer; value_as_long | |
565 | handles all the cases. */ | |
c906108c | 566 | CORE_ADDR |
f23631e4 | 567 | value_as_address (struct value *val) |
c906108c SS |
568 | { |
569 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
570 | whether we want this to be true eventually. */ | |
571 | #if 0 | |
572 | /* ADDR_BITS_REMOVE is wrong if we are being called for a | |
573 | non-address (e.g. argument to "signal", "info break", etc.), or | |
574 | for pointers to char, in which the low bits *are* significant. */ | |
c5aa993b | 575 | return ADDR_BITS_REMOVE (value_as_long (val)); |
c906108c | 576 | #else |
f312f057 JB |
577 | |
578 | /* There are several targets (IA-64, PowerPC, and others) which | |
579 | don't represent pointers to functions as simply the address of | |
580 | the function's entry point. For example, on the IA-64, a | |
581 | function pointer points to a two-word descriptor, generated by | |
582 | the linker, which contains the function's entry point, and the | |
583 | value the IA-64 "global pointer" register should have --- to | |
584 | support position-independent code. The linker generates | |
585 | descriptors only for those functions whose addresses are taken. | |
586 | ||
587 | On such targets, it's difficult for GDB to convert an arbitrary | |
588 | function address into a function pointer; it has to either find | |
589 | an existing descriptor for that function, or call malloc and | |
590 | build its own. On some targets, it is impossible for GDB to | |
591 | build a descriptor at all: the descriptor must contain a jump | |
592 | instruction; data memory cannot be executed; and code memory | |
593 | cannot be modified. | |
594 | ||
595 | Upon entry to this function, if VAL is a value of type `function' | |
596 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
597 | VALUE_ADDRESS (val) is the address of the function. This is what | |
598 | you'll get if you evaluate an expression like `main'. The call | |
599 | to COERCE_ARRAY below actually does all the usual unary | |
600 | conversions, which includes converting values of type `function' | |
601 | to `pointer to function'. This is the challenging conversion | |
602 | discussed above. Then, `unpack_long' will convert that pointer | |
603 | back into an address. | |
604 | ||
605 | So, suppose the user types `disassemble foo' on an architecture | |
606 | with a strange function pointer representation, on which GDB | |
607 | cannot build its own descriptors, and suppose further that `foo' | |
608 | has no linker-built descriptor. The address->pointer conversion | |
609 | will signal an error and prevent the command from running, even | |
610 | though the next step would have been to convert the pointer | |
611 | directly back into the same address. | |
612 | ||
613 | The following shortcut avoids this whole mess. If VAL is a | |
614 | function, just return its address directly. */ | |
615 | if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC | |
616 | || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_METHOD) | |
617 | return VALUE_ADDRESS (val); | |
618 | ||
67b2adb2 | 619 | COERCE_ARRAY (val); |
fc0c74b1 AC |
620 | |
621 | /* Some architectures (e.g. Harvard), map instruction and data | |
622 | addresses onto a single large unified address space. For | |
623 | instance: An architecture may consider a large integer in the | |
624 | range 0x10000000 .. 0x1000ffff to already represent a data | |
625 | addresses (hence not need a pointer to address conversion) while | |
626 | a small integer would still need to be converted integer to | |
627 | pointer to address. Just assume such architectures handle all | |
628 | integer conversions in a single function. */ | |
629 | ||
630 | /* JimB writes: | |
631 | ||
632 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
633 | must admonish GDB hackers to make sure its behavior matches the | |
634 | compiler's, whenever possible. | |
635 | ||
636 | In general, I think GDB should evaluate expressions the same way | |
637 | the compiler does. When the user copies an expression out of | |
638 | their source code and hands it to a `print' command, they should | |
639 | get the same value the compiler would have computed. Any | |
640 | deviation from this rule can cause major confusion and annoyance, | |
641 | and needs to be justified carefully. In other words, GDB doesn't | |
642 | really have the freedom to do these conversions in clever and | |
643 | useful ways. | |
644 | ||
645 | AndrewC pointed out that users aren't complaining about how GDB | |
646 | casts integers to pointers; they are complaining that they can't | |
647 | take an address from a disassembly listing and give it to `x/i'. | |
648 | This is certainly important. | |
649 | ||
650 | Adding an architecture method like INTEGER_TO_ADDRESS certainly | |
651 | makes it possible for GDB to "get it right" in all circumstances | |
652 | --- the target has complete control over how things get done, so | |
653 | people can Do The Right Thing for their target without breaking | |
654 | anyone else. The standard doesn't specify how integers get | |
655 | converted to pointers; usually, the ABI doesn't either, but | |
656 | ABI-specific code is a more reasonable place to handle it. */ | |
657 | ||
658 | if (TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_PTR | |
659 | && TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_REF | |
660 | && INTEGER_TO_ADDRESS_P ()) | |
661 | return INTEGER_TO_ADDRESS (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
662 | ||
67b2adb2 | 663 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); |
c906108c SS |
664 | #endif |
665 | } | |
666 | \f | |
667 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
668 | as a long, or as a double, assuming the raw data is described | |
669 | by type TYPE. Knows how to convert different sizes of values | |
670 | and can convert between fixed and floating point. We don't assume | |
671 | any alignment for the raw data. Return value is in host byte order. | |
672 | ||
673 | If you want functions and arrays to be coerced to pointers, and | |
674 | references to be dereferenced, call value_as_long() instead. | |
675 | ||
676 | C++: It is assumed that the front-end has taken care of | |
677 | all matters concerning pointers to members. A pointer | |
678 | to member which reaches here is considered to be equivalent | |
679 | to an INT (or some size). After all, it is only an offset. */ | |
680 | ||
681 | LONGEST | |
fba45db2 | 682 | unpack_long (struct type *type, char *valaddr) |
c906108c SS |
683 | { |
684 | register enum type_code code = TYPE_CODE (type); | |
685 | register int len = TYPE_LENGTH (type); | |
686 | register int nosign = TYPE_UNSIGNED (type); | |
687 | ||
688 | if (current_language->la_language == language_scm | |
689 | && is_scmvalue_type (type)) | |
690 | return scm_unpack (type, valaddr, TYPE_CODE_INT); | |
691 | ||
692 | switch (code) | |
693 | { | |
694 | case TYPE_CODE_TYPEDEF: | |
695 | return unpack_long (check_typedef (type), valaddr); | |
696 | case TYPE_CODE_ENUM: | |
697 | case TYPE_CODE_BOOL: | |
698 | case TYPE_CODE_INT: | |
699 | case TYPE_CODE_CHAR: | |
700 | case TYPE_CODE_RANGE: | |
701 | if (nosign) | |
702 | return extract_unsigned_integer (valaddr, len); | |
703 | else | |
704 | return extract_signed_integer (valaddr, len); | |
705 | ||
706 | case TYPE_CODE_FLT: | |
96d2f608 | 707 | return extract_typed_floating (valaddr, type); |
c906108c SS |
708 | |
709 | case TYPE_CODE_PTR: | |
710 | case TYPE_CODE_REF: | |
711 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 712 | whether we want this to be true eventually. */ |
4478b372 | 713 | return extract_typed_address (valaddr, type); |
c906108c SS |
714 | |
715 | case TYPE_CODE_MEMBER: | |
716 | error ("not implemented: member types in unpack_long"); | |
717 | ||
718 | default: | |
719 | error ("Value can't be converted to integer."); | |
720 | } | |
c5aa993b | 721 | return 0; /* Placate lint. */ |
c906108c SS |
722 | } |
723 | ||
724 | /* Return a double value from the specified type and address. | |
725 | INVP points to an int which is set to 0 for valid value, | |
726 | 1 for invalid value (bad float format). In either case, | |
727 | the returned double is OK to use. Argument is in target | |
728 | format, result is in host format. */ | |
729 | ||
730 | DOUBLEST | |
fba45db2 | 731 | unpack_double (struct type *type, char *valaddr, int *invp) |
c906108c SS |
732 | { |
733 | enum type_code code; | |
734 | int len; | |
735 | int nosign; | |
736 | ||
737 | *invp = 0; /* Assume valid. */ | |
738 | CHECK_TYPEDEF (type); | |
739 | code = TYPE_CODE (type); | |
740 | len = TYPE_LENGTH (type); | |
741 | nosign = TYPE_UNSIGNED (type); | |
742 | if (code == TYPE_CODE_FLT) | |
743 | { | |
75bc7ddf AC |
744 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
745 | floating-point value was valid (using the macro | |
746 | INVALID_FLOAT). That test/macro have been removed. | |
747 | ||
748 | It turns out that only the VAX defined this macro and then | |
749 | only in a non-portable way. Fixing the portability problem | |
750 | wouldn't help since the VAX floating-point code is also badly | |
751 | bit-rotten. The target needs to add definitions for the | |
752 | methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these | |
753 | exactly describe the target floating-point format. The | |
754 | problem here is that the corresponding floatformat_vax_f and | |
755 | floatformat_vax_d values these methods should be set to are | |
756 | also not defined either. Oops! | |
757 | ||
758 | Hopefully someone will add both the missing floatformat | |
759 | definitions and floatformat_is_invalid() function. */ | |
96d2f608 | 760 | return extract_typed_floating (valaddr, type); |
c906108c SS |
761 | } |
762 | else if (nosign) | |
763 | { | |
764 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 765 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
766 | } |
767 | else | |
768 | { | |
769 | /* Signed -- we are OK with unpack_long. */ | |
770 | return unpack_long (type, valaddr); | |
771 | } | |
772 | } | |
773 | ||
774 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
775 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
776 | We don't assume any alignment for the raw data. Return value is in | |
777 | host byte order. | |
778 | ||
779 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 780 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
781 | |
782 | C++: It is assumed that the front-end has taken care of | |
783 | all matters concerning pointers to members. A pointer | |
784 | to member which reaches here is considered to be equivalent | |
785 | to an INT (or some size). After all, it is only an offset. */ | |
786 | ||
787 | CORE_ADDR | |
fba45db2 | 788 | unpack_pointer (struct type *type, char *valaddr) |
c906108c SS |
789 | { |
790 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
791 | whether we want this to be true eventually. */ | |
792 | return unpack_long (type, valaddr); | |
793 | } | |
4478b372 | 794 | |
c906108c SS |
795 | \f |
796 | /* Get the value of the FIELDN'th field (which must be static) of TYPE. */ | |
797 | ||
f23631e4 | 798 | struct value * |
fba45db2 | 799 | value_static_field (struct type *type, int fieldno) |
c906108c SS |
800 | { |
801 | CORE_ADDR addr; | |
802 | asection *sect; | |
803 | if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) | |
804 | { | |
805 | addr = TYPE_FIELD_STATIC_PHYSADDR (type, fieldno); | |
806 | sect = NULL; | |
807 | } | |
808 | else | |
809 | { | |
810 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
811 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL); | |
812 | if (sym == NULL) | |
813 | { | |
814 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
815 | as non-debuggable symbols */ |
816 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
817 | if (!msym) |
818 | return NULL; | |
819 | else | |
c5aa993b | 820 | { |
c906108c SS |
821 | addr = SYMBOL_VALUE_ADDRESS (msym); |
822 | sect = SYMBOL_BFD_SECTION (msym); | |
823 | } | |
824 | } | |
825 | else | |
826 | { | |
2b127877 DB |
827 | /* Anything static that isn't a constant, has an address */ |
828 | if (SYMBOL_CLASS (sym) != LOC_CONST) | |
829 | { | |
830 | addr = SYMBOL_VALUE_ADDRESS (sym); | |
831 | sect = SYMBOL_BFD_SECTION (sym); | |
832 | } | |
833 | /* However, static const's do not, the value is already known. */ | |
834 | else | |
835 | { | |
836 | return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), SYMBOL_VALUE (sym)); | |
837 | } | |
838 | } | |
c906108c SS |
839 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), addr); |
840 | } | |
841 | return value_at (TYPE_FIELD_TYPE (type, fieldno), addr, sect); | |
842 | } | |
843 | ||
2b127877 DB |
844 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
845 | You have to be careful here, since the size of the data area for the value | |
846 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
847 | than the old enclosing type, you have to allocate more space for the data. | |
848 | The return value is a pointer to the new version of this value structure. */ | |
849 | ||
f23631e4 AC |
850 | struct value * |
851 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) | |
2b127877 DB |
852 | { |
853 | if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val))) | |
854 | { | |
855 | VALUE_ENCLOSING_TYPE (val) = new_encl_type; | |
856 | return val; | |
857 | } | |
858 | else | |
859 | { | |
f23631e4 AC |
860 | struct value *new_val; |
861 | struct value *prev; | |
2b127877 | 862 | |
f23631e4 | 863 | new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); |
2b127877 DB |
864 | |
865 | /* We have to make sure this ends up in the same place in the value | |
866 | chain as the original copy, so it's clean-up behavior is the same. | |
867 | If the value has been released, this is a waste of time, but there | |
868 | is no way to tell that in advance, so... */ | |
869 | ||
870 | if (val != all_values) | |
871 | { | |
872 | for (prev = all_values; prev != NULL; prev = prev->next) | |
873 | { | |
874 | if (prev->next == val) | |
875 | { | |
876 | prev->next = new_val; | |
877 | break; | |
878 | } | |
879 | } | |
880 | } | |
881 | ||
882 | return new_val; | |
883 | } | |
884 | } | |
885 | ||
c906108c SS |
886 | /* Given a value ARG1 (offset by OFFSET bytes) |
887 | of a struct or union type ARG_TYPE, | |
888 | extract and return the value of one of its (non-static) fields. | |
889 | FIELDNO says which field. */ | |
890 | ||
f23631e4 AC |
891 | struct value * |
892 | value_primitive_field (struct value *arg1, int offset, | |
fba45db2 | 893 | register int fieldno, register struct type *arg_type) |
c906108c | 894 | { |
f23631e4 | 895 | struct value *v; |
c906108c SS |
896 | register struct type *type; |
897 | ||
898 | CHECK_TYPEDEF (arg_type); | |
899 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
900 | ||
901 | /* Handle packed fields */ | |
902 | ||
903 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
904 | { | |
905 | v = value_from_longest (type, | |
906 | unpack_field_as_long (arg_type, | |
907 | VALUE_CONTENTS (arg1) | |
c5aa993b | 908 | + offset, |
c906108c SS |
909 | fieldno)); |
910 | VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; | |
911 | VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
2e70b7b9 MS |
912 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
913 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
914 | } |
915 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
916 | { | |
917 | /* This field is actually a base subobject, so preserve the | |
918 | entire object's contents for later references to virtual | |
919 | bases, etc. */ | |
920 | v = allocate_value (VALUE_ENCLOSING_TYPE (arg1)); | |
8d65888a | 921 | VALUE_TYPE (v) = type; |
c906108c SS |
922 | if (VALUE_LAZY (arg1)) |
923 | VALUE_LAZY (v) = 1; | |
924 | else | |
925 | memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1), | |
926 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1))); | |
927 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1); | |
928 | VALUE_EMBEDDED_OFFSET (v) | |
c5aa993b JM |
929 | = offset + |
930 | VALUE_EMBEDDED_OFFSET (arg1) + | |
931 | TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
932 | } |
933 | else | |
934 | { | |
935 | /* Plain old data member */ | |
936 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
937 | v = allocate_value (type); | |
938 | if (VALUE_LAZY (arg1)) | |
939 | VALUE_LAZY (v) = 1; | |
940 | else | |
941 | memcpy (VALUE_CONTENTS_RAW (v), | |
942 | VALUE_CONTENTS_RAW (arg1) + offset, | |
943 | TYPE_LENGTH (type)); | |
21cfb3b6 DJ |
944 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
945 | + VALUE_EMBEDDED_OFFSET (arg1); | |
c906108c SS |
946 | } |
947 | VALUE_LVAL (v) = VALUE_LVAL (arg1); | |
948 | if (VALUE_LVAL (arg1) == lval_internalvar) | |
949 | VALUE_LVAL (v) = lval_internalvar_component; | |
950 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); | |
a88c1392 | 951 | VALUE_REGNO (v) = VALUE_REGNO (arg1); |
c906108c | 952 | /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
c5aa993b | 953 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ |
c906108c SS |
954 | return v; |
955 | } | |
956 | ||
957 | /* Given a value ARG1 of a struct or union type, | |
958 | extract and return the value of one of its (non-static) fields. | |
959 | FIELDNO says which field. */ | |
960 | ||
f23631e4 AC |
961 | struct value * |
962 | value_field (struct value *arg1, register int fieldno) | |
c906108c SS |
963 | { |
964 | return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1)); | |
965 | } | |
966 | ||
967 | /* Return a non-virtual function as a value. | |
968 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
969 | J is an index into F which provides the desired method. |
970 | ||
971 | We only use the symbol for its address, so be happy with either a | |
972 | full symbol or a minimal symbol. | |
973 | */ | |
c906108c | 974 | |
f23631e4 AC |
975 | struct value * |
976 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, | |
fba45db2 | 977 | int offset) |
c906108c | 978 | { |
f23631e4 | 979 | struct value *v; |
c906108c | 980 | register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
0478d61c | 981 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 982 | struct symbol *sym; |
0478d61c | 983 | struct minimal_symbol *msym; |
c906108c | 984 | |
0478d61c | 985 | sym = lookup_symbol (physname, 0, VAR_NAMESPACE, 0, NULL); |
5ae326fa | 986 | if (sym != NULL) |
0478d61c | 987 | { |
5ae326fa AC |
988 | msym = NULL; |
989 | } | |
990 | else | |
991 | { | |
992 | gdb_assert (sym == NULL); | |
0478d61c | 993 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
994 | if (msym == NULL) |
995 | return NULL; | |
0478d61c FF |
996 | } |
997 | ||
c906108c | 998 | v = allocate_value (ftype); |
0478d61c FF |
999 | if (sym) |
1000 | { | |
1001 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
1002 | } | |
1003 | else | |
1004 | { | |
1005 | VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); | |
1006 | } | |
c906108c SS |
1007 | |
1008 | if (arg1p) | |
c5aa993b JM |
1009 | { |
1010 | if (type != VALUE_TYPE (*arg1p)) | |
1011 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), | |
1012 | value_addr (*arg1p))); | |
1013 | ||
070ad9f0 | 1014 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1015 | VALUE_OFFSET (*arg1p) += offset; |
1016 | */ | |
c906108c SS |
1017 | } |
1018 | ||
1019 | return v; | |
1020 | } | |
1021 | ||
c906108c SS |
1022 | \f |
1023 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1024 | VALADDR. | |
1025 | ||
1026 | Extracting bits depends on endianness of the machine. Compute the | |
1027 | number of least significant bits to discard. For big endian machines, | |
1028 | we compute the total number of bits in the anonymous object, subtract | |
1029 | off the bit count from the MSB of the object to the MSB of the | |
1030 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1031 | count. For little endian machines, the discard count is simply the | |
1032 | number of bits from the LSB of the anonymous object to the LSB of the | |
1033 | bitfield. | |
1034 | ||
1035 | If the field is signed, we also do sign extension. */ | |
1036 | ||
1037 | LONGEST | |
fba45db2 | 1038 | unpack_field_as_long (struct type *type, char *valaddr, int fieldno) |
c906108c SS |
1039 | { |
1040 | ULONGEST val; | |
1041 | ULONGEST valmask; | |
1042 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1043 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1044 | int lsbcount; | |
1045 | struct type *field_type; | |
1046 | ||
1047 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1048 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1049 | CHECK_TYPEDEF (field_type); | |
1050 | ||
1051 | /* Extract bits. See comment above. */ | |
1052 | ||
1053 | if (BITS_BIG_ENDIAN) | |
1054 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); | |
1055 | else | |
1056 | lsbcount = (bitpos % 8); | |
1057 | val >>= lsbcount; | |
1058 | ||
1059 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1060 | If the field is signed, and is negative, then sign extend. */ | |
1061 | ||
1062 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1063 | { | |
1064 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1065 | val &= valmask; | |
1066 | if (!TYPE_UNSIGNED (field_type)) | |
1067 | { | |
1068 | if (val & (valmask ^ (valmask >> 1))) | |
1069 | { | |
1070 | val |= ~valmask; | |
1071 | } | |
1072 | } | |
1073 | } | |
1074 | return (val); | |
1075 | } | |
1076 | ||
1077 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1078 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1079 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
1080 | indicate which bits (in target bit order) comprise the bitfield. */ | |
1081 | ||
1082 | void | |
fba45db2 | 1083 | modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c SS |
1084 | { |
1085 | LONGEST oword; | |
1086 | ||
1087 | /* If a negative fieldval fits in the field in question, chop | |
1088 | off the sign extension bits. */ | |
1089 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
1090 | && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) | |
1091 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1092 | ||
1093 | /* Warn if value is too big to fit in the field in question. */ | |
1094 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
c5aa993b | 1095 | && 0 != (fieldval & ~((1 << bitsize) - 1))) |
c906108c SS |
1096 | { |
1097 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1098 | we don't have a sprintf_longest. */ |
c906108c SS |
1099 | warning ("Value does not fit in %d bits.", bitsize); |
1100 | ||
1101 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
1102 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1103 | } | |
1104 | ||
1105 | oword = extract_signed_integer (addr, sizeof oword); | |
1106 | ||
1107 | /* Shifting for bit field depends on endianness of the target machine. */ | |
1108 | if (BITS_BIG_ENDIAN) | |
1109 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; | |
1110 | ||
1111 | /* Mask out old value, while avoiding shifts >= size of oword */ | |
1112 | if (bitsize < 8 * (int) sizeof (oword)) | |
c5aa993b | 1113 | oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos); |
c906108c | 1114 | else |
c5aa993b | 1115 | oword &= ~((~(ULONGEST) 0) << bitpos); |
c906108c SS |
1116 | oword |= fieldval << bitpos; |
1117 | ||
1118 | store_signed_integer (addr, sizeof oword, oword); | |
1119 | } | |
1120 | \f | |
1121 | /* Convert C numbers into newly allocated values */ | |
1122 | ||
f23631e4 | 1123 | struct value * |
fba45db2 | 1124 | value_from_longest (struct type *type, register LONGEST num) |
c906108c | 1125 | { |
f23631e4 | 1126 | struct value *val = allocate_value (type); |
c906108c SS |
1127 | register enum type_code code; |
1128 | register int len; | |
c5aa993b | 1129 | retry: |
c906108c SS |
1130 | code = TYPE_CODE (type); |
1131 | len = TYPE_LENGTH (type); | |
1132 | ||
1133 | switch (code) | |
1134 | { | |
1135 | case TYPE_CODE_TYPEDEF: | |
1136 | type = check_typedef (type); | |
1137 | goto retry; | |
1138 | case TYPE_CODE_INT: | |
1139 | case TYPE_CODE_CHAR: | |
1140 | case TYPE_CODE_ENUM: | |
1141 | case TYPE_CODE_BOOL: | |
1142 | case TYPE_CODE_RANGE: | |
1143 | store_signed_integer (VALUE_CONTENTS_RAW (val), len, num); | |
1144 | break; | |
c5aa993b | 1145 | |
c906108c SS |
1146 | case TYPE_CODE_REF: |
1147 | case TYPE_CODE_PTR: | |
4478b372 | 1148 | store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num); |
c906108c | 1149 | break; |
c5aa993b | 1150 | |
c906108c SS |
1151 | default: |
1152 | error ("Unexpected type (%d) encountered for integer constant.", code); | |
1153 | } | |
1154 | return val; | |
1155 | } | |
1156 | ||
4478b372 JB |
1157 | |
1158 | /* Create a value representing a pointer of type TYPE to the address | |
1159 | ADDR. */ | |
f23631e4 | 1160 | struct value * |
4478b372 JB |
1161 | value_from_pointer (struct type *type, CORE_ADDR addr) |
1162 | { | |
f23631e4 | 1163 | struct value *val = allocate_value (type); |
4478b372 JB |
1164 | store_typed_address (VALUE_CONTENTS_RAW (val), type, addr); |
1165 | return val; | |
1166 | } | |
1167 | ||
1168 | ||
0f71a2f6 | 1169 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1170 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1171 | This is analogous to value_from_longest, which also does not |
1172 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1173 | ||
f23631e4 | 1174 | struct value * |
fba45db2 | 1175 | value_from_string (char *ptr) |
0f71a2f6 | 1176 | { |
f23631e4 | 1177 | struct value *val; |
c5aa993b | 1178 | int len = strlen (ptr); |
0f71a2f6 | 1179 | int lowbound = current_language->string_lower_bound; |
c5aa993b JM |
1180 | struct type *rangetype = |
1181 | create_range_type ((struct type *) NULL, | |
1182 | builtin_type_int, | |
1183 | lowbound, len + lowbound - 1); | |
1184 | struct type *stringtype = | |
1185 | create_array_type ((struct type *) NULL, | |
1186 | *current_language->string_char_type, | |
1187 | rangetype); | |
0f71a2f6 JM |
1188 | |
1189 | val = allocate_value (stringtype); | |
1190 | memcpy (VALUE_CONTENTS_RAW (val), ptr, len); | |
1191 | return val; | |
1192 | } | |
1193 | ||
f23631e4 | 1194 | struct value * |
fba45db2 | 1195 | value_from_double (struct type *type, DOUBLEST num) |
c906108c | 1196 | { |
f23631e4 | 1197 | struct value *val = allocate_value (type); |
c906108c SS |
1198 | struct type *base_type = check_typedef (type); |
1199 | register enum type_code code = TYPE_CODE (base_type); | |
1200 | register int len = TYPE_LENGTH (base_type); | |
1201 | ||
1202 | if (code == TYPE_CODE_FLT) | |
1203 | { | |
96d2f608 | 1204 | store_typed_floating (VALUE_CONTENTS_RAW (val), base_type, num); |
c906108c SS |
1205 | } |
1206 | else | |
1207 | error ("Unexpected type encountered for floating constant."); | |
1208 | ||
1209 | return val; | |
1210 | } | |
1211 | \f | |
1212 | /* Deal with the value that is "about to be returned". */ | |
1213 | ||
1214 | /* Return the value that a function returning now | |
1215 | would be returning to its caller, assuming its type is VALTYPE. | |
1216 | RETBUF is where we look for what ought to be the contents | |
1217 | of the registers (in raw form). This is because it is often | |
1218 | desirable to restore old values to those registers | |
1219 | after saving the contents of interest, and then call | |
1220 | this function using the saved values. | |
1221 | struct_return is non-zero when the function in question is | |
1222 | using the structure return conventions on the machine in question; | |
1223 | 0 when it is using the value returning conventions (this often | |
1224 | means returning pointer to where structure is vs. returning value). */ | |
1225 | ||
1669605f | 1226 | /* ARGSUSED */ |
f23631e4 | 1227 | struct value * |
049ee0e4 | 1228 | value_being_returned (struct type *valtype, struct regcache *retbuf, |
36160dc4 | 1229 | int struct_return) |
c906108c | 1230 | { |
f23631e4 | 1231 | struct value *val; |
c906108c SS |
1232 | CORE_ADDR addr; |
1233 | ||
c906108c | 1234 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ |
d6dd581e | 1235 | if (EXTRACT_STRUCT_VALUE_ADDRESS_P ()) |
ac9a91a7 JM |
1236 | if (struct_return) |
1237 | { | |
1238 | addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf); | |
1239 | if (!addr) | |
aead120c | 1240 | error ("Function return value unknown."); |
ac9a91a7 JM |
1241 | return value_at (valtype, addr, NULL); |
1242 | } | |
26e9b323 AC |
1243 | |
1244 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ | |
1245 | if (DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS_P ()) | |
1246 | if (struct_return) | |
1247 | { | |
049ee0e4 AC |
1248 | char *buf = deprecated_grub_regcache_for_registers (retbuf); |
1249 | addr = DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS (buf); | |
26e9b323 AC |
1250 | if (!addr) |
1251 | error ("Function return value unknown."); | |
1252 | return value_at (valtype, addr, NULL); | |
1253 | } | |
c906108c SS |
1254 | |
1255 | val = allocate_value (valtype); | |
1256 | CHECK_TYPEDEF (valtype); | |
1257 | EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val)); | |
1258 | ||
1259 | return val; | |
1260 | } | |
1261 | ||
1262 | /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of | |
1263 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc | |
1264 | and TYPE is the type (which is known to be struct, union or array). | |
1265 | ||
1266 | On most machines, the struct convention is used unless we are | |
1267 | using gcc and the type is of a special size. */ | |
1268 | /* As of about 31 Mar 93, GCC was changed to be compatible with the | |
1269 | native compiler. GCC 2.3.3 was the last release that did it the | |
1270 | old way. Since gcc2_compiled was not changed, we have no | |
1271 | way to correctly win in all cases, so we just do the right thing | |
1272 | for gcc1 and for gcc2 after this change. Thus it loses for gcc | |
1273 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled | |
1274 | would cause more chaos than dealing with some struct returns being | |
1275 | handled wrong. */ | |
1276 | ||
1277 | int | |
fba45db2 | 1278 | generic_use_struct_convention (int gcc_p, struct type *value_type) |
c5aa993b | 1279 | { |
c906108c | 1280 | return !((gcc_p == 1) |
c5aa993b JM |
1281 | && (TYPE_LENGTH (value_type) == 1 |
1282 | || TYPE_LENGTH (value_type) == 2 | |
1283 | || TYPE_LENGTH (value_type) == 4 | |
1284 | || TYPE_LENGTH (value_type) == 8)); | |
c906108c SS |
1285 | } |
1286 | ||
c906108c SS |
1287 | /* Return true if the function specified is using the structure returning |
1288 | convention on this machine to return arguments, or 0 if it is using | |
1289 | the value returning convention. FUNCTION is the value representing | |
1290 | the function, FUNCADDR is the address of the function, and VALUE_TYPE | |
1291 | is the type returned by the function. GCC_P is nonzero if compiled | |
1292 | with GCC. */ | |
1293 | ||
1669605f | 1294 | /* ARGSUSED */ |
c906108c | 1295 | int |
f23631e4 | 1296 | using_struct_return (struct value *function, CORE_ADDR funcaddr, |
1669605f | 1297 | struct type *value_type, int gcc_p) |
c906108c SS |
1298 | { |
1299 | register enum type_code code = TYPE_CODE (value_type); | |
1300 | ||
1301 | if (code == TYPE_CODE_ERROR) | |
1302 | error ("Function return type unknown."); | |
1303 | ||
1304 | if (code == TYPE_CODE_STRUCT | |
1305 | || code == TYPE_CODE_UNION | |
1306 | || code == TYPE_CODE_ARRAY | |
1307 | || RETURN_VALUE_ON_STACK (value_type)) | |
1308 | return USE_STRUCT_CONVENTION (gcc_p, value_type); | |
1309 | ||
1310 | return 0; | |
1311 | } | |
1312 | ||
1313 | /* Store VAL so it will be returned if a function returns now. | |
1314 | Does not verify that VAL's type matches what the current | |
1315 | function wants to return. */ | |
1316 | ||
1317 | void | |
f23631e4 | 1318 | set_return_value (struct value *val) |
c906108c SS |
1319 | { |
1320 | struct type *type = check_typedef (VALUE_TYPE (val)); | |
1321 | register enum type_code code = TYPE_CODE (type); | |
1322 | ||
1323 | if (code == TYPE_CODE_ERROR) | |
1324 | error ("Function return type unknown."); | |
1325 | ||
c5aa993b | 1326 | if (code == TYPE_CODE_STRUCT |
c906108c SS |
1327 | || code == TYPE_CODE_UNION) /* FIXME, implement struct return. */ |
1328 | error ("GDB does not support specifying a struct or union return value."); | |
1329 | ||
1330 | STORE_RETURN_VALUE (type, VALUE_CONTENTS (val)); | |
1331 | } | |
1332 | \f | |
1333 | void | |
fba45db2 | 1334 | _initialize_values (void) |
c906108c SS |
1335 | { |
1336 | add_cmd ("convenience", no_class, show_convenience, | |
c5aa993b | 1337 | "Debugger convenience (\"$foo\") variables.\n\ |
c906108c SS |
1338 | These variables are created when you assign them values;\n\ |
1339 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ | |
1340 | A few convenience variables are given values automatically:\n\ | |
1341 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1342 | \"$__\" holds the contents of the last address examined with \"x\".", | |
1343 | &showlist); | |
1344 | ||
1345 | add_cmd ("values", no_class, show_values, | |
1346 | "Elements of value history around item number IDX (or last ten).", | |
1347 | &showlist); | |
1348 | } |