Commit | Line | Data |
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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
1bac305b | 2 | |
f23631e4 | 3 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, |
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" |
c906108c SS |
39 | |
40 | /* Prototypes for exported functions. */ | |
41 | ||
a14ed312 | 42 | void _initialize_values (void); |
c906108c SS |
43 | |
44 | /* Prototypes for local functions. */ | |
45 | ||
a14ed312 | 46 | static void show_values (char *, int); |
c906108c | 47 | |
a14ed312 | 48 | static void show_convenience (char *, int); |
c906108c | 49 | |
c906108c SS |
50 | |
51 | /* The value-history records all the values printed | |
52 | by print commands during this session. Each chunk | |
53 | records 60 consecutive values. The first chunk on | |
54 | the chain records the most recent values. | |
55 | The total number of values is in value_history_count. */ | |
56 | ||
57 | #define VALUE_HISTORY_CHUNK 60 | |
58 | ||
59 | struct value_history_chunk | |
c5aa993b JM |
60 | { |
61 | struct value_history_chunk *next; | |
f23631e4 | 62 | struct value *values[VALUE_HISTORY_CHUNK]; |
c5aa993b | 63 | }; |
c906108c SS |
64 | |
65 | /* Chain of chunks now in use. */ | |
66 | ||
67 | static struct value_history_chunk *value_history_chain; | |
68 | ||
69 | static int value_history_count; /* Abs number of last entry stored */ | |
70 | \f | |
71 | /* List of all value objects currently allocated | |
72 | (except for those released by calls to release_value) | |
73 | This is so they can be freed after each command. */ | |
74 | ||
f23631e4 | 75 | static struct value *all_values; |
c906108c SS |
76 | |
77 | /* Allocate a value that has the correct length for type TYPE. */ | |
78 | ||
f23631e4 | 79 | struct value * |
fba45db2 | 80 | allocate_value (struct type *type) |
c906108c | 81 | { |
f23631e4 | 82 | struct value *val; |
c906108c SS |
83 | struct type *atype = check_typedef (type); |
84 | ||
85 | val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype)); | |
86 | VALUE_NEXT (val) = all_values; | |
87 | all_values = val; | |
88 | VALUE_TYPE (val) = type; | |
89 | VALUE_ENCLOSING_TYPE (val) = type; | |
90 | VALUE_LVAL (val) = not_lval; | |
91 | VALUE_ADDRESS (val) = 0; | |
92 | VALUE_FRAME (val) = 0; | |
93 | VALUE_OFFSET (val) = 0; | |
94 | VALUE_BITPOS (val) = 0; | |
95 | VALUE_BITSIZE (val) = 0; | |
96 | VALUE_REGNO (val) = -1; | |
97 | VALUE_LAZY (val) = 0; | |
98 | VALUE_OPTIMIZED_OUT (val) = 0; | |
99 | VALUE_BFD_SECTION (val) = NULL; | |
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 | ||
124 | /* Return a mark in the value chain. All values allocated after the | |
125 | mark is obtained (except for those released) are subject to being freed | |
126 | if a subsequent value_free_to_mark is passed the mark. */ | |
f23631e4 | 127 | struct value * |
fba45db2 | 128 | value_mark (void) |
c906108c SS |
129 | { |
130 | return all_values; | |
131 | } | |
132 | ||
133 | /* Free all values allocated since MARK was obtained by value_mark | |
134 | (except for those released). */ | |
135 | void | |
f23631e4 | 136 | value_free_to_mark (struct value *mark) |
c906108c | 137 | { |
f23631e4 AC |
138 | struct value *val; |
139 | struct value *next; | |
c906108c SS |
140 | |
141 | for (val = all_values; val && val != mark; val = next) | |
142 | { | |
143 | next = VALUE_NEXT (val); | |
144 | value_free (val); | |
145 | } | |
146 | all_values = val; | |
147 | } | |
148 | ||
149 | /* Free all the values that have been allocated (except for those released). | |
150 | Called after each command, successful or not. */ | |
151 | ||
152 | void | |
fba45db2 | 153 | free_all_values (void) |
c906108c | 154 | { |
f23631e4 AC |
155 | struct value *val; |
156 | struct value *next; | |
c906108c SS |
157 | |
158 | for (val = all_values; val; val = next) | |
159 | { | |
160 | next = VALUE_NEXT (val); | |
161 | value_free (val); | |
162 | } | |
163 | ||
164 | all_values = 0; | |
165 | } | |
166 | ||
167 | /* Remove VAL from the chain all_values | |
168 | so it will not be freed automatically. */ | |
169 | ||
170 | void | |
f23631e4 | 171 | release_value (struct value *val) |
c906108c | 172 | { |
f23631e4 | 173 | struct value *v; |
c906108c SS |
174 | |
175 | if (all_values == val) | |
176 | { | |
177 | all_values = val->next; | |
178 | return; | |
179 | } | |
180 | ||
181 | for (v = all_values; v; v = v->next) | |
182 | { | |
183 | if (v->next == val) | |
184 | { | |
185 | v->next = val->next; | |
186 | break; | |
187 | } | |
188 | } | |
189 | } | |
190 | ||
191 | /* Release all values up to mark */ | |
f23631e4 AC |
192 | struct value * |
193 | value_release_to_mark (struct value *mark) | |
c906108c | 194 | { |
f23631e4 AC |
195 | struct value *val; |
196 | struct value *next; | |
c906108c SS |
197 | |
198 | for (val = next = all_values; next; next = VALUE_NEXT (next)) | |
199 | if (VALUE_NEXT (next) == mark) | |
200 | { | |
201 | all_values = VALUE_NEXT (next); | |
202 | VALUE_NEXT (next) = 0; | |
203 | return val; | |
204 | } | |
205 | all_values = 0; | |
206 | return val; | |
207 | } | |
208 | ||
209 | /* Return a copy of the value ARG. | |
210 | It contains the same contents, for same memory address, | |
211 | but it's a different block of storage. */ | |
212 | ||
f23631e4 AC |
213 | struct value * |
214 | value_copy (struct value *arg) | |
c906108c SS |
215 | { |
216 | register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg); | |
f23631e4 | 217 | struct value *val = allocate_value (encl_type); |
c906108c SS |
218 | VALUE_TYPE (val) = VALUE_TYPE (arg); |
219 | VALUE_LVAL (val) = VALUE_LVAL (arg); | |
220 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); | |
221 | VALUE_OFFSET (val) = VALUE_OFFSET (arg); | |
222 | VALUE_BITPOS (val) = VALUE_BITPOS (arg); | |
223 | VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); | |
224 | VALUE_FRAME (val) = VALUE_FRAME (arg); | |
225 | VALUE_REGNO (val) = VALUE_REGNO (arg); | |
226 | VALUE_LAZY (val) = VALUE_LAZY (arg); | |
227 | VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg); | |
228 | VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg); | |
229 | VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg); | |
230 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg); | |
231 | val->modifiable = arg->modifiable; | |
232 | if (!VALUE_LAZY (val)) | |
233 | { | |
234 | memcpy (VALUE_CONTENTS_ALL_RAW (val), VALUE_CONTENTS_ALL_RAW (arg), | |
235 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg))); | |
236 | ||
237 | } | |
238 | return val; | |
239 | } | |
240 | \f | |
241 | /* Access to the value history. */ | |
242 | ||
243 | /* Record a new value in the value history. | |
244 | Returns the absolute history index of the entry. | |
245 | Result of -1 indicates the value was not saved; otherwise it is the | |
246 | value history index of this new item. */ | |
247 | ||
248 | int | |
f23631e4 | 249 | record_latest_value (struct value *val) |
c906108c SS |
250 | { |
251 | int i; | |
252 | ||
253 | /* We don't want this value to have anything to do with the inferior anymore. | |
254 | In particular, "set $1 = 50" should not affect the variable from which | |
255 | the value was taken, and fast watchpoints should be able to assume that | |
256 | a value on the value history never changes. */ | |
257 | if (VALUE_LAZY (val)) | |
258 | value_fetch_lazy (val); | |
259 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
260 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
261 | but the current contents of that location. c'est la vie... */ | |
262 | val->modifiable = 0; | |
263 | release_value (val); | |
264 | ||
265 | /* Here we treat value_history_count as origin-zero | |
266 | and applying to the value being stored now. */ | |
267 | ||
268 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
269 | if (i == 0) | |
270 | { | |
f23631e4 | 271 | struct value_history_chunk *new |
c5aa993b JM |
272 | = (struct value_history_chunk *) |
273 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
274 | memset (new->values, 0, sizeof new->values); |
275 | new->next = value_history_chain; | |
276 | value_history_chain = new; | |
277 | } | |
278 | ||
279 | value_history_chain->values[i] = val; | |
280 | ||
281 | /* Now we regard value_history_count as origin-one | |
282 | and applying to the value just stored. */ | |
283 | ||
284 | return ++value_history_count; | |
285 | } | |
286 | ||
287 | /* Return a copy of the value in the history with sequence number NUM. */ | |
288 | ||
f23631e4 | 289 | struct value * |
fba45db2 | 290 | access_value_history (int num) |
c906108c | 291 | { |
f23631e4 | 292 | struct value_history_chunk *chunk; |
c906108c SS |
293 | register int i; |
294 | register int absnum = num; | |
295 | ||
296 | if (absnum <= 0) | |
297 | absnum += value_history_count; | |
298 | ||
299 | if (absnum <= 0) | |
300 | { | |
301 | if (num == 0) | |
302 | error ("The history is empty."); | |
303 | else if (num == 1) | |
304 | error ("There is only one value in the history."); | |
305 | else | |
306 | error ("History does not go back to $$%d.", -num); | |
307 | } | |
308 | if (absnum > value_history_count) | |
309 | error ("History has not yet reached $%d.", absnum); | |
310 | ||
311 | absnum--; | |
312 | ||
313 | /* Now absnum is always absolute and origin zero. */ | |
314 | ||
315 | chunk = value_history_chain; | |
316 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
317 | i > 0; i--) | |
318 | chunk = chunk->next; | |
319 | ||
320 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
321 | } | |
322 | ||
323 | /* Clear the value history entirely. | |
324 | Must be done when new symbol tables are loaded, | |
325 | because the type pointers become invalid. */ | |
326 | ||
327 | void | |
fba45db2 | 328 | clear_value_history (void) |
c906108c | 329 | { |
f23631e4 | 330 | struct value_history_chunk *next; |
c906108c | 331 | register int i; |
f23631e4 | 332 | struct value *val; |
c906108c SS |
333 | |
334 | while (value_history_chain) | |
335 | { | |
336 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
337 | if ((val = value_history_chain->values[i]) != NULL) | |
b8c9b27d | 338 | xfree (val); |
c906108c | 339 | next = value_history_chain->next; |
b8c9b27d | 340 | xfree (value_history_chain); |
c906108c SS |
341 | value_history_chain = next; |
342 | } | |
343 | value_history_count = 0; | |
344 | } | |
345 | ||
346 | static void | |
fba45db2 | 347 | show_values (char *num_exp, int from_tty) |
c906108c SS |
348 | { |
349 | register int i; | |
f23631e4 | 350 | struct value *val; |
c906108c SS |
351 | static int num = 1; |
352 | ||
353 | if (num_exp) | |
354 | { | |
c5aa993b JM |
355 | /* "info history +" should print from the stored position. |
356 | "info history <exp>" should print around value number <exp>. */ | |
c906108c | 357 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 358 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
359 | } |
360 | else | |
361 | { | |
362 | /* "info history" means print the last 10 values. */ | |
363 | num = value_history_count - 9; | |
364 | } | |
365 | ||
366 | if (num <= 0) | |
367 | num = 1; | |
368 | ||
369 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
370 | { | |
371 | val = access_value_history (i); | |
372 | printf_filtered ("$%d = ", i); | |
373 | value_print (val, gdb_stdout, 0, Val_pretty_default); | |
374 | printf_filtered ("\n"); | |
375 | } | |
376 | ||
377 | /* The next "info history +" should start after what we just printed. */ | |
378 | num += 10; | |
379 | ||
380 | /* Hitting just return after this command should do the same thing as | |
381 | "info history +". If num_exp is null, this is unnecessary, since | |
382 | "info history +" is not useful after "info history". */ | |
383 | if (from_tty && num_exp) | |
384 | { | |
385 | num_exp[0] = '+'; | |
386 | num_exp[1] = '\0'; | |
387 | } | |
388 | } | |
389 | \f | |
390 | /* Internal variables. These are variables within the debugger | |
391 | that hold values assigned by debugger commands. | |
392 | The user refers to them with a '$' prefix | |
393 | that does not appear in the variable names stored internally. */ | |
394 | ||
395 | static struct internalvar *internalvars; | |
396 | ||
397 | /* Look up an internal variable with name NAME. NAME should not | |
398 | normally include a dollar sign. | |
399 | ||
400 | If the specified internal variable does not exist, | |
401 | one is created, with a void value. */ | |
402 | ||
403 | struct internalvar * | |
fba45db2 | 404 | lookup_internalvar (char *name) |
c906108c SS |
405 | { |
406 | register struct internalvar *var; | |
407 | ||
408 | for (var = internalvars; var; var = var->next) | |
409 | if (STREQ (var->name, name)) | |
410 | return var; | |
411 | ||
412 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); | |
413 | var->name = concat (name, NULL); | |
414 | var->value = allocate_value (builtin_type_void); | |
415 | release_value (var->value); | |
416 | var->next = internalvars; | |
417 | internalvars = var; | |
418 | return var; | |
419 | } | |
420 | ||
f23631e4 | 421 | struct value * |
fba45db2 | 422 | value_of_internalvar (struct internalvar *var) |
c906108c | 423 | { |
f23631e4 | 424 | struct value *val; |
c906108c SS |
425 | |
426 | #ifdef IS_TRAPPED_INTERNALVAR | |
427 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
428 | return VALUE_OF_TRAPPED_INTERNALVAR (var); | |
c5aa993b | 429 | #endif |
c906108c SS |
430 | |
431 | val = value_copy (var->value); | |
432 | if (VALUE_LAZY (val)) | |
433 | value_fetch_lazy (val); | |
434 | VALUE_LVAL (val) = lval_internalvar; | |
435 | VALUE_INTERNALVAR (val) = var; | |
436 | return val; | |
437 | } | |
438 | ||
439 | void | |
fba45db2 | 440 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
f23631e4 | 441 | int bitsize, struct value *newval) |
c906108c SS |
442 | { |
443 | register char *addr = VALUE_CONTENTS (var->value) + offset; | |
444 | ||
445 | #ifdef IS_TRAPPED_INTERNALVAR | |
446 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
447 | SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); | |
448 | #endif | |
449 | ||
450 | if (bitsize) | |
451 | modify_field (addr, value_as_long (newval), | |
452 | bitpos, bitsize); | |
453 | else | |
454 | memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval))); | |
455 | } | |
456 | ||
457 | void | |
f23631e4 | 458 | set_internalvar (struct internalvar *var, struct value *val) |
c906108c | 459 | { |
f23631e4 | 460 | struct value *newval; |
c906108c SS |
461 | |
462 | #ifdef IS_TRAPPED_INTERNALVAR | |
463 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
464 | SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); | |
465 | #endif | |
466 | ||
467 | newval = value_copy (val); | |
468 | newval->modifiable = 1; | |
469 | ||
470 | /* Force the value to be fetched from the target now, to avoid problems | |
471 | later when this internalvar is referenced and the target is gone or | |
472 | has changed. */ | |
473 | if (VALUE_LAZY (newval)) | |
474 | value_fetch_lazy (newval); | |
475 | ||
476 | /* Begin code which must not call error(). If var->value points to | |
477 | something free'd, an error() obviously leaves a dangling pointer. | |
478 | But we also get a danling pointer if var->value points to | |
479 | something in the value chain (i.e., before release_value is | |
480 | called), because after the error free_all_values will get called before | |
481 | long. */ | |
b8c9b27d | 482 | xfree (var->value); |
c906108c SS |
483 | var->value = newval; |
484 | release_value (newval); | |
485 | /* End code which must not call error(). */ | |
486 | } | |
487 | ||
488 | char * | |
fba45db2 | 489 | internalvar_name (struct internalvar *var) |
c906108c SS |
490 | { |
491 | return var->name; | |
492 | } | |
493 | ||
494 | /* Free all internalvars. Done when new symtabs are loaded, | |
495 | because that makes the values invalid. */ | |
496 | ||
497 | void | |
fba45db2 | 498 | clear_internalvars (void) |
c906108c SS |
499 | { |
500 | register struct internalvar *var; | |
501 | ||
502 | while (internalvars) | |
503 | { | |
504 | var = internalvars; | |
505 | internalvars = var->next; | |
b8c9b27d KB |
506 | xfree (var->name); |
507 | xfree (var->value); | |
508 | xfree (var); | |
c906108c SS |
509 | } |
510 | } | |
511 | ||
512 | static void | |
fba45db2 | 513 | show_convenience (char *ignore, int from_tty) |
c906108c SS |
514 | { |
515 | register struct internalvar *var; | |
516 | int varseen = 0; | |
517 | ||
518 | for (var = internalvars; var; var = var->next) | |
519 | { | |
520 | #ifdef IS_TRAPPED_INTERNALVAR | |
521 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
522 | continue; | |
523 | #endif | |
524 | if (!varseen) | |
525 | { | |
526 | varseen = 1; | |
527 | } | |
528 | printf_filtered ("$%s = ", var->name); | |
529 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); | |
530 | printf_filtered ("\n"); | |
531 | } | |
532 | if (!varseen) | |
533 | printf_unfiltered ("No debugger convenience variables now defined.\n\ | |
534 | Convenience variables have names starting with \"$\";\n\ | |
535 | use \"set\" as in \"set $foo = 5\" to define them.\n"); | |
536 | } | |
537 | \f | |
538 | /* Extract a value as a C number (either long or double). | |
539 | Knows how to convert fixed values to double, or | |
540 | floating values to long. | |
541 | Does not deallocate the value. */ | |
542 | ||
543 | LONGEST | |
f23631e4 | 544 | value_as_long (struct value *val) |
c906108c SS |
545 | { |
546 | /* This coerces arrays and functions, which is necessary (e.g. | |
547 | in disassemble_command). It also dereferences references, which | |
548 | I suspect is the most logical thing to do. */ | |
549 | COERCE_ARRAY (val); | |
550 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
551 | } | |
552 | ||
553 | DOUBLEST | |
f23631e4 | 554 | value_as_double (struct value *val) |
c906108c SS |
555 | { |
556 | DOUBLEST foo; | |
557 | int inv; | |
c5aa993b | 558 | |
c906108c SS |
559 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv); |
560 | if (inv) | |
561 | error ("Invalid floating value found in program."); | |
562 | return foo; | |
563 | } | |
4478b372 JB |
564 | /* Extract a value as a C pointer. Does not deallocate the value. |
565 | Note that val's type may not actually be a pointer; value_as_long | |
566 | handles all the cases. */ | |
c906108c | 567 | CORE_ADDR |
f23631e4 | 568 | value_as_address (struct value *val) |
c906108c SS |
569 | { |
570 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
571 | whether we want this to be true eventually. */ | |
572 | #if 0 | |
573 | /* ADDR_BITS_REMOVE is wrong if we are being called for a | |
574 | non-address (e.g. argument to "signal", "info break", etc.), or | |
575 | for pointers to char, in which the low bits *are* significant. */ | |
c5aa993b | 576 | return ADDR_BITS_REMOVE (value_as_long (val)); |
c906108c | 577 | #else |
f312f057 JB |
578 | |
579 | /* There are several targets (IA-64, PowerPC, and others) which | |
580 | don't represent pointers to functions as simply the address of | |
581 | the function's entry point. For example, on the IA-64, a | |
582 | function pointer points to a two-word descriptor, generated by | |
583 | the linker, which contains the function's entry point, and the | |
584 | value the IA-64 "global pointer" register should have --- to | |
585 | support position-independent code. The linker generates | |
586 | descriptors only for those functions whose addresses are taken. | |
587 | ||
588 | On such targets, it's difficult for GDB to convert an arbitrary | |
589 | function address into a function pointer; it has to either find | |
590 | an existing descriptor for that function, or call malloc and | |
591 | build its own. On some targets, it is impossible for GDB to | |
592 | build a descriptor at all: the descriptor must contain a jump | |
593 | instruction; data memory cannot be executed; and code memory | |
594 | cannot be modified. | |
595 | ||
596 | Upon entry to this function, if VAL is a value of type `function' | |
597 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
598 | VALUE_ADDRESS (val) is the address of the function. This is what | |
599 | you'll get if you evaluate an expression like `main'. The call | |
600 | to COERCE_ARRAY below actually does all the usual unary | |
601 | conversions, which includes converting values of type `function' | |
602 | to `pointer to function'. This is the challenging conversion | |
603 | discussed above. Then, `unpack_long' will convert that pointer | |
604 | back into an address. | |
605 | ||
606 | So, suppose the user types `disassemble foo' on an architecture | |
607 | with a strange function pointer representation, on which GDB | |
608 | cannot build its own descriptors, and suppose further that `foo' | |
609 | has no linker-built descriptor. The address->pointer conversion | |
610 | will signal an error and prevent the command from running, even | |
611 | though the next step would have been to convert the pointer | |
612 | directly back into the same address. | |
613 | ||
614 | The following shortcut avoids this whole mess. If VAL is a | |
615 | function, just return its address directly. */ | |
616 | if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC | |
617 | || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_METHOD) | |
618 | return VALUE_ADDRESS (val); | |
619 | ||
67b2adb2 | 620 | COERCE_ARRAY (val); |
fc0c74b1 AC |
621 | |
622 | /* Some architectures (e.g. Harvard), map instruction and data | |
623 | addresses onto a single large unified address space. For | |
624 | instance: An architecture may consider a large integer in the | |
625 | range 0x10000000 .. 0x1000ffff to already represent a data | |
626 | addresses (hence not need a pointer to address conversion) while | |
627 | a small integer would still need to be converted integer to | |
628 | pointer to address. Just assume such architectures handle all | |
629 | integer conversions in a single function. */ | |
630 | ||
631 | /* JimB writes: | |
632 | ||
633 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
634 | must admonish GDB hackers to make sure its behavior matches the | |
635 | compiler's, whenever possible. | |
636 | ||
637 | In general, I think GDB should evaluate expressions the same way | |
638 | the compiler does. When the user copies an expression out of | |
639 | their source code and hands it to a `print' command, they should | |
640 | get the same value the compiler would have computed. Any | |
641 | deviation from this rule can cause major confusion and annoyance, | |
642 | and needs to be justified carefully. In other words, GDB doesn't | |
643 | really have the freedom to do these conversions in clever and | |
644 | useful ways. | |
645 | ||
646 | AndrewC pointed out that users aren't complaining about how GDB | |
647 | casts integers to pointers; they are complaining that they can't | |
648 | take an address from a disassembly listing and give it to `x/i'. | |
649 | This is certainly important. | |
650 | ||
651 | Adding an architecture method like INTEGER_TO_ADDRESS certainly | |
652 | makes it possible for GDB to "get it right" in all circumstances | |
653 | --- the target has complete control over how things get done, so | |
654 | people can Do The Right Thing for their target without breaking | |
655 | anyone else. The standard doesn't specify how integers get | |
656 | converted to pointers; usually, the ABI doesn't either, but | |
657 | ABI-specific code is a more reasonable place to handle it. */ | |
658 | ||
659 | if (TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_PTR | |
660 | && TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_REF | |
661 | && INTEGER_TO_ADDRESS_P ()) | |
662 | return INTEGER_TO_ADDRESS (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
663 | ||
67b2adb2 | 664 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); |
c906108c SS |
665 | #endif |
666 | } | |
667 | \f | |
668 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
669 | as a long, or as a double, assuming the raw data is described | |
670 | by type TYPE. Knows how to convert different sizes of values | |
671 | and can convert between fixed and floating point. We don't assume | |
672 | any alignment for the raw data. Return value is in host byte order. | |
673 | ||
674 | If you want functions and arrays to be coerced to pointers, and | |
675 | references to be dereferenced, call value_as_long() instead. | |
676 | ||
677 | C++: It is assumed that the front-end has taken care of | |
678 | all matters concerning pointers to members. A pointer | |
679 | to member which reaches here is considered to be equivalent | |
680 | to an INT (or some size). After all, it is only an offset. */ | |
681 | ||
682 | LONGEST | |
66140c26 | 683 | unpack_long (struct type *type, const char *valaddr) |
c906108c SS |
684 | { |
685 | register enum type_code code = TYPE_CODE (type); | |
686 | register int len = TYPE_LENGTH (type); | |
687 | register int nosign = TYPE_UNSIGNED (type); | |
688 | ||
689 | if (current_language->la_language == language_scm | |
690 | && is_scmvalue_type (type)) | |
691 | return scm_unpack (type, valaddr, TYPE_CODE_INT); | |
692 | ||
693 | switch (code) | |
694 | { | |
695 | case TYPE_CODE_TYPEDEF: | |
696 | return unpack_long (check_typedef (type), valaddr); | |
697 | case TYPE_CODE_ENUM: | |
698 | case TYPE_CODE_BOOL: | |
699 | case TYPE_CODE_INT: | |
700 | case TYPE_CODE_CHAR: | |
701 | case TYPE_CODE_RANGE: | |
702 | if (nosign) | |
703 | return extract_unsigned_integer (valaddr, len); | |
704 | else | |
705 | return extract_signed_integer (valaddr, len); | |
706 | ||
707 | case TYPE_CODE_FLT: | |
96d2f608 | 708 | return extract_typed_floating (valaddr, type); |
c906108c SS |
709 | |
710 | case TYPE_CODE_PTR: | |
711 | case TYPE_CODE_REF: | |
712 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 713 | whether we want this to be true eventually. */ |
4478b372 | 714 | return extract_typed_address (valaddr, type); |
c906108c SS |
715 | |
716 | case TYPE_CODE_MEMBER: | |
717 | error ("not implemented: member types in unpack_long"); | |
718 | ||
719 | default: | |
720 | error ("Value can't be converted to integer."); | |
721 | } | |
c5aa993b | 722 | return 0; /* Placate lint. */ |
c906108c SS |
723 | } |
724 | ||
725 | /* Return a double value from the specified type and address. | |
726 | INVP points to an int which is set to 0 for valid value, | |
727 | 1 for invalid value (bad float format). In either case, | |
728 | the returned double is OK to use. Argument is in target | |
729 | format, result is in host format. */ | |
730 | ||
731 | DOUBLEST | |
66140c26 | 732 | unpack_double (struct type *type, const char *valaddr, int *invp) |
c906108c SS |
733 | { |
734 | enum type_code code; | |
735 | int len; | |
736 | int nosign; | |
737 | ||
738 | *invp = 0; /* Assume valid. */ | |
739 | CHECK_TYPEDEF (type); | |
740 | code = TYPE_CODE (type); | |
741 | len = TYPE_LENGTH (type); | |
742 | nosign = TYPE_UNSIGNED (type); | |
743 | if (code == TYPE_CODE_FLT) | |
744 | { | |
75bc7ddf AC |
745 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
746 | floating-point value was valid (using the macro | |
747 | INVALID_FLOAT). That test/macro have been removed. | |
748 | ||
749 | It turns out that only the VAX defined this macro and then | |
750 | only in a non-portable way. Fixing the portability problem | |
751 | wouldn't help since the VAX floating-point code is also badly | |
752 | bit-rotten. The target needs to add definitions for the | |
753 | methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these | |
754 | exactly describe the target floating-point format. The | |
755 | problem here is that the corresponding floatformat_vax_f and | |
756 | floatformat_vax_d values these methods should be set to are | |
757 | also not defined either. Oops! | |
758 | ||
759 | Hopefully someone will add both the missing floatformat | |
760 | definitions and floatformat_is_invalid() function. */ | |
96d2f608 | 761 | return extract_typed_floating (valaddr, type); |
c906108c SS |
762 | } |
763 | else if (nosign) | |
764 | { | |
765 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 766 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
767 | } |
768 | else | |
769 | { | |
770 | /* Signed -- we are OK with unpack_long. */ | |
771 | return unpack_long (type, valaddr); | |
772 | } | |
773 | } | |
774 | ||
775 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
776 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
777 | We don't assume any alignment for the raw data. Return value is in | |
778 | host byte order. | |
779 | ||
780 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 781 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
782 | |
783 | C++: It is assumed that the front-end has taken care of | |
784 | all matters concerning pointers to members. A pointer | |
785 | to member which reaches here is considered to be equivalent | |
786 | to an INT (or some size). After all, it is only an offset. */ | |
787 | ||
788 | CORE_ADDR | |
66140c26 | 789 | unpack_pointer (struct type *type, const char *valaddr) |
c906108c SS |
790 | { |
791 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
792 | whether we want this to be true eventually. */ | |
793 | return unpack_long (type, valaddr); | |
794 | } | |
4478b372 | 795 | |
c906108c | 796 | \f |
2c2738a0 DC |
797 | /* Get the value of the FIELDN'th field (which must be static) of |
798 | TYPE. Return NULL if the field doesn't exist or has been | |
799 | optimized out. */ | |
c906108c | 800 | |
f23631e4 | 801 | struct value * |
fba45db2 | 802 | value_static_field (struct type *type, int fieldno) |
c906108c | 803 | { |
948e66d9 DJ |
804 | struct value *retval; |
805 | ||
c906108c SS |
806 | if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) |
807 | { | |
948e66d9 DJ |
808 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
809 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno), | |
810 | NULL); | |
c906108c SS |
811 | } |
812 | else | |
813 | { | |
814 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
815 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL); | |
948e66d9 | 816 | if (sym == NULL) |
c906108c SS |
817 | { |
818 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
819 | as non-debuggable symbols */ |
820 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
821 | if (!msym) |
822 | return NULL; | |
823 | else | |
c5aa993b | 824 | { |
948e66d9 DJ |
825 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
826 | SYMBOL_VALUE_ADDRESS (msym), | |
827 | SYMBOL_BFD_SECTION (msym)); | |
c906108c SS |
828 | } |
829 | } | |
830 | else | |
831 | { | |
948e66d9 DJ |
832 | /* SYM should never have a SYMBOL_CLASS which will require |
833 | read_var_value to use the FRAME parameter. */ | |
834 | if (symbol_read_needs_frame (sym)) | |
835 | warning ("static field's value depends on the current " | |
836 | "frame - bad debug info?"); | |
837 | retval = read_var_value (sym, NULL); | |
2b127877 | 838 | } |
948e66d9 DJ |
839 | if (retval && VALUE_LVAL (retval) == lval_memory) |
840 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), | |
841 | VALUE_ADDRESS (retval)); | |
c906108c | 842 | } |
948e66d9 | 843 | return retval; |
c906108c SS |
844 | } |
845 | ||
2b127877 DB |
846 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
847 | You have to be careful here, since the size of the data area for the value | |
848 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
849 | than the old enclosing type, you have to allocate more space for the data. | |
850 | The return value is a pointer to the new version of this value structure. */ | |
851 | ||
f23631e4 AC |
852 | struct value * |
853 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) | |
2b127877 DB |
854 | { |
855 | if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val))) | |
856 | { | |
857 | VALUE_ENCLOSING_TYPE (val) = new_encl_type; | |
858 | return val; | |
859 | } | |
860 | else | |
861 | { | |
f23631e4 AC |
862 | struct value *new_val; |
863 | struct value *prev; | |
2b127877 | 864 | |
f23631e4 | 865 | new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); |
cc303028 PM |
866 | |
867 | VALUE_ENCLOSING_TYPE (new_val) = new_encl_type; | |
868 | ||
2b127877 DB |
869 | /* We have to make sure this ends up in the same place in the value |
870 | chain as the original copy, so it's clean-up behavior is the same. | |
871 | If the value has been released, this is a waste of time, but there | |
872 | is no way to tell that in advance, so... */ | |
873 | ||
874 | if (val != all_values) | |
875 | { | |
876 | for (prev = all_values; prev != NULL; prev = prev->next) | |
877 | { | |
878 | if (prev->next == val) | |
879 | { | |
880 | prev->next = new_val; | |
881 | break; | |
882 | } | |
883 | } | |
884 | } | |
885 | ||
886 | return new_val; | |
887 | } | |
888 | } | |
889 | ||
c906108c SS |
890 | /* Given a value ARG1 (offset by OFFSET bytes) |
891 | of a struct or union type ARG_TYPE, | |
892 | extract and return the value of one of its (non-static) fields. | |
893 | FIELDNO says which field. */ | |
894 | ||
f23631e4 AC |
895 | struct value * |
896 | value_primitive_field (struct value *arg1, int offset, | |
fba45db2 | 897 | register int fieldno, register struct type *arg_type) |
c906108c | 898 | { |
f23631e4 | 899 | struct value *v; |
c906108c SS |
900 | register struct type *type; |
901 | ||
902 | CHECK_TYPEDEF (arg_type); | |
903 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
904 | ||
905 | /* Handle packed fields */ | |
906 | ||
907 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
908 | { | |
909 | v = value_from_longest (type, | |
910 | unpack_field_as_long (arg_type, | |
911 | VALUE_CONTENTS (arg1) | |
c5aa993b | 912 | + offset, |
c906108c SS |
913 | fieldno)); |
914 | VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; | |
915 | VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
2e70b7b9 MS |
916 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
917 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
918 | } |
919 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
920 | { | |
921 | /* This field is actually a base subobject, so preserve the | |
922 | entire object's contents for later references to virtual | |
923 | bases, etc. */ | |
924 | v = allocate_value (VALUE_ENCLOSING_TYPE (arg1)); | |
8d65888a | 925 | VALUE_TYPE (v) = type; |
c906108c SS |
926 | if (VALUE_LAZY (arg1)) |
927 | VALUE_LAZY (v) = 1; | |
928 | else | |
929 | memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1), | |
930 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1))); | |
931 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1); | |
932 | VALUE_EMBEDDED_OFFSET (v) | |
c5aa993b JM |
933 | = offset + |
934 | VALUE_EMBEDDED_OFFSET (arg1) + | |
935 | TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
936 | } |
937 | else | |
938 | { | |
939 | /* Plain old data member */ | |
940 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
941 | v = allocate_value (type); | |
942 | if (VALUE_LAZY (arg1)) | |
943 | VALUE_LAZY (v) = 1; | |
944 | else | |
945 | memcpy (VALUE_CONTENTS_RAW (v), | |
946 | VALUE_CONTENTS_RAW (arg1) + offset, | |
947 | TYPE_LENGTH (type)); | |
21cfb3b6 DJ |
948 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
949 | + VALUE_EMBEDDED_OFFSET (arg1); | |
c906108c SS |
950 | } |
951 | VALUE_LVAL (v) = VALUE_LVAL (arg1); | |
952 | if (VALUE_LVAL (arg1) == lval_internalvar) | |
953 | VALUE_LVAL (v) = lval_internalvar_component; | |
954 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); | |
a88c1392 | 955 | VALUE_REGNO (v) = VALUE_REGNO (arg1); |
c906108c | 956 | /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
c5aa993b | 957 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ |
c906108c SS |
958 | return v; |
959 | } | |
960 | ||
961 | /* Given a value ARG1 of a struct or union type, | |
962 | extract and return the value of one of its (non-static) fields. | |
963 | FIELDNO says which field. */ | |
964 | ||
f23631e4 AC |
965 | struct value * |
966 | value_field (struct value *arg1, register int fieldno) | |
c906108c SS |
967 | { |
968 | return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1)); | |
969 | } | |
970 | ||
971 | /* Return a non-virtual function as a value. | |
972 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
973 | J is an index into F which provides the desired method. |
974 | ||
975 | We only use the symbol for its address, so be happy with either a | |
976 | full symbol or a minimal symbol. | |
977 | */ | |
c906108c | 978 | |
f23631e4 AC |
979 | struct value * |
980 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, | |
fba45db2 | 981 | int offset) |
c906108c | 982 | { |
f23631e4 | 983 | struct value *v; |
c906108c | 984 | register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
0478d61c | 985 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 986 | struct symbol *sym; |
0478d61c | 987 | struct minimal_symbol *msym; |
c906108c | 988 | |
0478d61c | 989 | sym = lookup_symbol (physname, 0, VAR_NAMESPACE, 0, NULL); |
5ae326fa | 990 | if (sym != NULL) |
0478d61c | 991 | { |
5ae326fa AC |
992 | msym = NULL; |
993 | } | |
994 | else | |
995 | { | |
996 | gdb_assert (sym == NULL); | |
0478d61c | 997 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
998 | if (msym == NULL) |
999 | return NULL; | |
0478d61c FF |
1000 | } |
1001 | ||
c906108c | 1002 | v = allocate_value (ftype); |
0478d61c FF |
1003 | if (sym) |
1004 | { | |
1005 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
1006 | } | |
1007 | else | |
1008 | { | |
1009 | VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); | |
1010 | } | |
c906108c SS |
1011 | |
1012 | if (arg1p) | |
c5aa993b JM |
1013 | { |
1014 | if (type != VALUE_TYPE (*arg1p)) | |
1015 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), | |
1016 | value_addr (*arg1p))); | |
1017 | ||
070ad9f0 | 1018 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1019 | VALUE_OFFSET (*arg1p) += offset; |
1020 | */ | |
c906108c SS |
1021 | } |
1022 | ||
1023 | return v; | |
1024 | } | |
1025 | ||
c906108c SS |
1026 | \f |
1027 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1028 | VALADDR. | |
1029 | ||
1030 | Extracting bits depends on endianness of the machine. Compute the | |
1031 | number of least significant bits to discard. For big endian machines, | |
1032 | we compute the total number of bits in the anonymous object, subtract | |
1033 | off the bit count from the MSB of the object to the MSB of the | |
1034 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1035 | count. For little endian machines, the discard count is simply the | |
1036 | number of bits from the LSB of the anonymous object to the LSB of the | |
1037 | bitfield. | |
1038 | ||
1039 | If the field is signed, we also do sign extension. */ | |
1040 | ||
1041 | LONGEST | |
66140c26 | 1042 | unpack_field_as_long (struct type *type, const char *valaddr, int fieldno) |
c906108c SS |
1043 | { |
1044 | ULONGEST val; | |
1045 | ULONGEST valmask; | |
1046 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1047 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1048 | int lsbcount; | |
1049 | struct type *field_type; | |
1050 | ||
1051 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1052 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1053 | CHECK_TYPEDEF (field_type); | |
1054 | ||
1055 | /* Extract bits. See comment above. */ | |
1056 | ||
1057 | if (BITS_BIG_ENDIAN) | |
1058 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); | |
1059 | else | |
1060 | lsbcount = (bitpos % 8); | |
1061 | val >>= lsbcount; | |
1062 | ||
1063 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1064 | If the field is signed, and is negative, then sign extend. */ | |
1065 | ||
1066 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1067 | { | |
1068 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1069 | val &= valmask; | |
1070 | if (!TYPE_UNSIGNED (field_type)) | |
1071 | { | |
1072 | if (val & (valmask ^ (valmask >> 1))) | |
1073 | { | |
1074 | val |= ~valmask; | |
1075 | } | |
1076 | } | |
1077 | } | |
1078 | return (val); | |
1079 | } | |
1080 | ||
1081 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1082 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1083 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
1084 | indicate which bits (in target bit order) comprise the bitfield. */ | |
1085 | ||
1086 | void | |
fba45db2 | 1087 | modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c SS |
1088 | { |
1089 | LONGEST oword; | |
1090 | ||
1091 | /* If a negative fieldval fits in the field in question, chop | |
1092 | off the sign extension bits. */ | |
1093 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
1094 | && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) | |
1095 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1096 | ||
1097 | /* Warn if value is too big to fit in the field in question. */ | |
1098 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
c5aa993b | 1099 | && 0 != (fieldval & ~((1 << bitsize) - 1))) |
c906108c SS |
1100 | { |
1101 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1102 | we don't have a sprintf_longest. */ |
c906108c SS |
1103 | warning ("Value does not fit in %d bits.", bitsize); |
1104 | ||
1105 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
1106 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1107 | } | |
1108 | ||
1109 | oword = extract_signed_integer (addr, sizeof oword); | |
1110 | ||
1111 | /* Shifting for bit field depends on endianness of the target machine. */ | |
1112 | if (BITS_BIG_ENDIAN) | |
1113 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; | |
1114 | ||
1115 | /* Mask out old value, while avoiding shifts >= size of oword */ | |
1116 | if (bitsize < 8 * (int) sizeof (oword)) | |
c5aa993b | 1117 | oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos); |
c906108c | 1118 | else |
c5aa993b | 1119 | oword &= ~((~(ULONGEST) 0) << bitpos); |
c906108c SS |
1120 | oword |= fieldval << bitpos; |
1121 | ||
1122 | store_signed_integer (addr, sizeof oword, oword); | |
1123 | } | |
1124 | \f | |
1125 | /* Convert C numbers into newly allocated values */ | |
1126 | ||
f23631e4 | 1127 | struct value * |
fba45db2 | 1128 | value_from_longest (struct type *type, register LONGEST num) |
c906108c | 1129 | { |
f23631e4 | 1130 | struct value *val = allocate_value (type); |
c906108c SS |
1131 | register enum type_code code; |
1132 | register int len; | |
c5aa993b | 1133 | retry: |
c906108c SS |
1134 | code = TYPE_CODE (type); |
1135 | len = TYPE_LENGTH (type); | |
1136 | ||
1137 | switch (code) | |
1138 | { | |
1139 | case TYPE_CODE_TYPEDEF: | |
1140 | type = check_typedef (type); | |
1141 | goto retry; | |
1142 | case TYPE_CODE_INT: | |
1143 | case TYPE_CODE_CHAR: | |
1144 | case TYPE_CODE_ENUM: | |
1145 | case TYPE_CODE_BOOL: | |
1146 | case TYPE_CODE_RANGE: | |
1147 | store_signed_integer (VALUE_CONTENTS_RAW (val), len, num); | |
1148 | break; | |
c5aa993b | 1149 | |
c906108c SS |
1150 | case TYPE_CODE_REF: |
1151 | case TYPE_CODE_PTR: | |
4478b372 | 1152 | store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num); |
c906108c | 1153 | break; |
c5aa993b | 1154 | |
c906108c SS |
1155 | default: |
1156 | error ("Unexpected type (%d) encountered for integer constant.", code); | |
1157 | } | |
1158 | return val; | |
1159 | } | |
1160 | ||
4478b372 JB |
1161 | |
1162 | /* Create a value representing a pointer of type TYPE to the address | |
1163 | ADDR. */ | |
f23631e4 | 1164 | struct value * |
4478b372 JB |
1165 | value_from_pointer (struct type *type, CORE_ADDR addr) |
1166 | { | |
f23631e4 | 1167 | struct value *val = allocate_value (type); |
4478b372 JB |
1168 | store_typed_address (VALUE_CONTENTS_RAW (val), type, addr); |
1169 | return val; | |
1170 | } | |
1171 | ||
1172 | ||
0f71a2f6 | 1173 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1174 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1175 | This is analogous to value_from_longest, which also does not |
1176 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1177 | ||
f23631e4 | 1178 | struct value * |
fba45db2 | 1179 | value_from_string (char *ptr) |
0f71a2f6 | 1180 | { |
f23631e4 | 1181 | struct value *val; |
c5aa993b | 1182 | int len = strlen (ptr); |
0f71a2f6 | 1183 | int lowbound = current_language->string_lower_bound; |
c5aa993b JM |
1184 | struct type *rangetype = |
1185 | create_range_type ((struct type *) NULL, | |
1186 | builtin_type_int, | |
1187 | lowbound, len + lowbound - 1); | |
1188 | struct type *stringtype = | |
1189 | create_array_type ((struct type *) NULL, | |
1190 | *current_language->string_char_type, | |
1191 | rangetype); | |
0f71a2f6 JM |
1192 | |
1193 | val = allocate_value (stringtype); | |
1194 | memcpy (VALUE_CONTENTS_RAW (val), ptr, len); | |
1195 | return val; | |
1196 | } | |
1197 | ||
f23631e4 | 1198 | struct value * |
fba45db2 | 1199 | value_from_double (struct type *type, DOUBLEST num) |
c906108c | 1200 | { |
f23631e4 | 1201 | struct value *val = allocate_value (type); |
c906108c SS |
1202 | struct type *base_type = check_typedef (type); |
1203 | register enum type_code code = TYPE_CODE (base_type); | |
1204 | register int len = TYPE_LENGTH (base_type); | |
1205 | ||
1206 | if (code == TYPE_CODE_FLT) | |
1207 | { | |
96d2f608 | 1208 | store_typed_floating (VALUE_CONTENTS_RAW (val), base_type, num); |
c906108c SS |
1209 | } |
1210 | else | |
1211 | error ("Unexpected type encountered for floating constant."); | |
1212 | ||
1213 | return val; | |
1214 | } | |
1215 | \f | |
1216 | /* Deal with the value that is "about to be returned". */ | |
1217 | ||
1218 | /* Return the value that a function returning now | |
1219 | would be returning to its caller, assuming its type is VALTYPE. | |
1220 | RETBUF is where we look for what ought to be the contents | |
1221 | of the registers (in raw form). This is because it is often | |
1222 | desirable to restore old values to those registers | |
1223 | after saving the contents of interest, and then call | |
1224 | this function using the saved values. | |
1225 | struct_return is non-zero when the function in question is | |
1226 | using the structure return conventions on the machine in question; | |
1227 | 0 when it is using the value returning conventions (this often | |
1228 | means returning pointer to where structure is vs. returning value). */ | |
1229 | ||
1669605f | 1230 | /* ARGSUSED */ |
f23631e4 | 1231 | struct value * |
049ee0e4 | 1232 | value_being_returned (struct type *valtype, struct regcache *retbuf, |
36160dc4 | 1233 | int struct_return) |
c906108c | 1234 | { |
f23631e4 | 1235 | struct value *val; |
c906108c SS |
1236 | CORE_ADDR addr; |
1237 | ||
c906108c | 1238 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ |
d6dd581e | 1239 | if (EXTRACT_STRUCT_VALUE_ADDRESS_P ()) |
ac9a91a7 JM |
1240 | if (struct_return) |
1241 | { | |
1242 | addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf); | |
1243 | if (!addr) | |
aead120c | 1244 | error ("Function return value unknown."); |
ac9a91a7 JM |
1245 | return value_at (valtype, addr, NULL); |
1246 | } | |
26e9b323 AC |
1247 | |
1248 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ | |
1249 | if (DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS_P ()) | |
1250 | if (struct_return) | |
1251 | { | |
049ee0e4 AC |
1252 | char *buf = deprecated_grub_regcache_for_registers (retbuf); |
1253 | addr = DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS (buf); | |
26e9b323 AC |
1254 | if (!addr) |
1255 | error ("Function return value unknown."); | |
1256 | return value_at (valtype, addr, NULL); | |
1257 | } | |
c906108c SS |
1258 | |
1259 | val = allocate_value (valtype); | |
1260 | CHECK_TYPEDEF (valtype); | |
1261 | EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val)); | |
1262 | ||
1263 | return val; | |
1264 | } | |
1265 | ||
1266 | /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of | |
1267 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc | |
1268 | and TYPE is the type (which is known to be struct, union or array). | |
1269 | ||
1270 | On most machines, the struct convention is used unless we are | |
1271 | using gcc and the type is of a special size. */ | |
1272 | /* As of about 31 Mar 93, GCC was changed to be compatible with the | |
1273 | native compiler. GCC 2.3.3 was the last release that did it the | |
1274 | old way. Since gcc2_compiled was not changed, we have no | |
1275 | way to correctly win in all cases, so we just do the right thing | |
1276 | for gcc1 and for gcc2 after this change. Thus it loses for gcc | |
1277 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled | |
1278 | would cause more chaos than dealing with some struct returns being | |
1279 | handled wrong. */ | |
1280 | ||
1281 | int | |
fba45db2 | 1282 | generic_use_struct_convention (int gcc_p, struct type *value_type) |
c5aa993b | 1283 | { |
c906108c | 1284 | return !((gcc_p == 1) |
c5aa993b JM |
1285 | && (TYPE_LENGTH (value_type) == 1 |
1286 | || TYPE_LENGTH (value_type) == 2 | |
1287 | || TYPE_LENGTH (value_type) == 4 | |
1288 | || TYPE_LENGTH (value_type) == 8)); | |
c906108c SS |
1289 | } |
1290 | ||
c906108c SS |
1291 | /* Return true if the function specified is using the structure returning |
1292 | convention on this machine to return arguments, or 0 if it is using | |
1293 | the value returning convention. FUNCTION is the value representing | |
1294 | the function, FUNCADDR is the address of the function, and VALUE_TYPE | |
1295 | is the type returned by the function. GCC_P is nonzero if compiled | |
1296 | with GCC. */ | |
1297 | ||
1669605f | 1298 | /* ARGSUSED */ |
c906108c | 1299 | int |
f23631e4 | 1300 | using_struct_return (struct value *function, CORE_ADDR funcaddr, |
1669605f | 1301 | struct type *value_type, int gcc_p) |
c906108c SS |
1302 | { |
1303 | register enum type_code code = TYPE_CODE (value_type); | |
1304 | ||
1305 | if (code == TYPE_CODE_ERROR) | |
1306 | error ("Function return type unknown."); | |
1307 | ||
1308 | if (code == TYPE_CODE_STRUCT | |
1309 | || code == TYPE_CODE_UNION | |
1310 | || code == TYPE_CODE_ARRAY | |
1311 | || RETURN_VALUE_ON_STACK (value_type)) | |
1312 | return USE_STRUCT_CONVENTION (gcc_p, value_type); | |
1313 | ||
1314 | return 0; | |
1315 | } | |
1316 | ||
1317 | /* Store VAL so it will be returned if a function returns now. | |
1318 | Does not verify that VAL's type matches what the current | |
1319 | function wants to return. */ | |
1320 | ||
1321 | void | |
f23631e4 | 1322 | set_return_value (struct value *val) |
c906108c SS |
1323 | { |
1324 | struct type *type = check_typedef (VALUE_TYPE (val)); | |
1325 | register enum type_code code = TYPE_CODE (type); | |
1326 | ||
1327 | if (code == TYPE_CODE_ERROR) | |
1328 | error ("Function return type unknown."); | |
1329 | ||
c5aa993b | 1330 | if (code == TYPE_CODE_STRUCT |
c906108c SS |
1331 | || code == TYPE_CODE_UNION) /* FIXME, implement struct return. */ |
1332 | error ("GDB does not support specifying a struct or union return value."); | |
1333 | ||
ebba8386 | 1334 | STORE_RETURN_VALUE (type, current_regcache, VALUE_CONTENTS (val)); |
c906108c SS |
1335 | } |
1336 | \f | |
1337 | void | |
fba45db2 | 1338 | _initialize_values (void) |
c906108c SS |
1339 | { |
1340 | add_cmd ("convenience", no_class, show_convenience, | |
c5aa993b | 1341 | "Debugger convenience (\"$foo\") variables.\n\ |
c906108c SS |
1342 | These variables are created when you assign them values;\n\ |
1343 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ | |
1344 | A few convenience variables are given values automatically:\n\ | |
1345 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1346 | \"$__\" holds the contents of the last address examined with \"x\".", | |
1347 | &showlist); | |
1348 | ||
1349 | add_cmd ("values", no_class, show_values, | |
1350 | "Elements of value history around item number IDX (or last ten).", | |
1351 | &showlist); | |
1352 | } |