Commit | Line | Data |
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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
b6ba6518 KB |
2 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
3 | 1996, 1997, 1998, 1999, 2000 | |
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" |
c906108c SS |
37 | |
38 | /* Prototypes for exported functions. */ | |
39 | ||
a14ed312 | 40 | void _initialize_values (void); |
c906108c SS |
41 | |
42 | /* Prototypes for local functions. */ | |
43 | ||
a14ed312 | 44 | static value_ptr value_headof (value_ptr, struct type *, struct type *); |
c906108c | 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; | |
62 | value_ptr values[VALUE_HISTORY_CHUNK]; | |
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 | ||
75 | static value_ptr all_values; | |
76 | ||
77 | /* Allocate a value that has the correct length for type TYPE. */ | |
78 | ||
79 | value_ptr | |
fba45db2 | 80 | allocate_value (struct type *type) |
c906108c SS |
81 | { |
82 | register value_ptr val; | |
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 | ||
109 | value_ptr | |
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. */ | |
127 | value_ptr | |
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 | |
fba45db2 | 136 | value_free_to_mark (value_ptr mark) |
c906108c SS |
137 | { |
138 | value_ptr val, next; | |
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 SS |
153 | { |
154 | register value_ptr val, next; | |
155 | ||
156 | for (val = all_values; val; val = next) | |
157 | { | |
158 | next = VALUE_NEXT (val); | |
159 | value_free (val); | |
160 | } | |
161 | ||
162 | all_values = 0; | |
163 | } | |
164 | ||
165 | /* Remove VAL from the chain all_values | |
166 | so it will not be freed automatically. */ | |
167 | ||
168 | void | |
fba45db2 | 169 | release_value (register value_ptr val) |
c906108c SS |
170 | { |
171 | register value_ptr v; | |
172 | ||
173 | if (all_values == val) | |
174 | { | |
175 | all_values = val->next; | |
176 | return; | |
177 | } | |
178 | ||
179 | for (v = all_values; v; v = v->next) | |
180 | { | |
181 | if (v->next == val) | |
182 | { | |
183 | v->next = val->next; | |
184 | break; | |
185 | } | |
186 | } | |
187 | } | |
188 | ||
189 | /* Release all values up to mark */ | |
190 | value_ptr | |
fba45db2 | 191 | value_release_to_mark (value_ptr mark) |
c906108c SS |
192 | { |
193 | value_ptr val, next; | |
194 | ||
195 | for (val = next = all_values; next; next = VALUE_NEXT (next)) | |
196 | if (VALUE_NEXT (next) == mark) | |
197 | { | |
198 | all_values = VALUE_NEXT (next); | |
199 | VALUE_NEXT (next) = 0; | |
200 | return val; | |
201 | } | |
202 | all_values = 0; | |
203 | return val; | |
204 | } | |
205 | ||
206 | /* Return a copy of the value ARG. | |
207 | It contains the same contents, for same memory address, | |
208 | but it's a different block of storage. */ | |
209 | ||
210 | value_ptr | |
fba45db2 | 211 | value_copy (value_ptr arg) |
c906108c SS |
212 | { |
213 | register struct type *encl_type = VALUE_ENCLOSING_TYPE (arg); | |
214 | register value_ptr val = allocate_value (encl_type); | |
215 | VALUE_TYPE (val) = VALUE_TYPE (arg); | |
216 | VALUE_LVAL (val) = VALUE_LVAL (arg); | |
217 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); | |
218 | VALUE_OFFSET (val) = VALUE_OFFSET (arg); | |
219 | VALUE_BITPOS (val) = VALUE_BITPOS (arg); | |
220 | VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); | |
221 | VALUE_FRAME (val) = VALUE_FRAME (arg); | |
222 | VALUE_REGNO (val) = VALUE_REGNO (arg); | |
223 | VALUE_LAZY (val) = VALUE_LAZY (arg); | |
224 | VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg); | |
225 | VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (arg); | |
226 | VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (arg); | |
227 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (arg); | |
228 | val->modifiable = arg->modifiable; | |
229 | if (!VALUE_LAZY (val)) | |
230 | { | |
231 | memcpy (VALUE_CONTENTS_ALL_RAW (val), VALUE_CONTENTS_ALL_RAW (arg), | |
232 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg))); | |
233 | ||
234 | } | |
235 | return val; | |
236 | } | |
237 | \f | |
238 | /* Access to the value history. */ | |
239 | ||
240 | /* Record a new value in the value history. | |
241 | Returns the absolute history index of the entry. | |
242 | Result of -1 indicates the value was not saved; otherwise it is the | |
243 | value history index of this new item. */ | |
244 | ||
245 | int | |
fba45db2 | 246 | record_latest_value (value_ptr val) |
c906108c SS |
247 | { |
248 | int i; | |
249 | ||
250 | /* We don't want this value to have anything to do with the inferior anymore. | |
251 | In particular, "set $1 = 50" should not affect the variable from which | |
252 | the value was taken, and fast watchpoints should be able to assume that | |
253 | a value on the value history never changes. */ | |
254 | if (VALUE_LAZY (val)) | |
255 | value_fetch_lazy (val); | |
256 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
257 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
258 | but the current contents of that location. c'est la vie... */ | |
259 | val->modifiable = 0; | |
260 | release_value (val); | |
261 | ||
262 | /* Here we treat value_history_count as origin-zero | |
263 | and applying to the value being stored now. */ | |
264 | ||
265 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
266 | if (i == 0) | |
267 | { | |
268 | register struct value_history_chunk *new | |
c5aa993b JM |
269 | = (struct value_history_chunk *) |
270 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
271 | memset (new->values, 0, sizeof new->values); |
272 | new->next = value_history_chain; | |
273 | value_history_chain = new; | |
274 | } | |
275 | ||
276 | value_history_chain->values[i] = val; | |
277 | ||
278 | /* Now we regard value_history_count as origin-one | |
279 | and applying to the value just stored. */ | |
280 | ||
281 | return ++value_history_count; | |
282 | } | |
283 | ||
284 | /* Return a copy of the value in the history with sequence number NUM. */ | |
285 | ||
286 | value_ptr | |
fba45db2 | 287 | access_value_history (int num) |
c906108c SS |
288 | { |
289 | register struct value_history_chunk *chunk; | |
290 | register int i; | |
291 | register int absnum = num; | |
292 | ||
293 | if (absnum <= 0) | |
294 | absnum += value_history_count; | |
295 | ||
296 | if (absnum <= 0) | |
297 | { | |
298 | if (num == 0) | |
299 | error ("The history is empty."); | |
300 | else if (num == 1) | |
301 | error ("There is only one value in the history."); | |
302 | else | |
303 | error ("History does not go back to $$%d.", -num); | |
304 | } | |
305 | if (absnum > value_history_count) | |
306 | error ("History has not yet reached $%d.", absnum); | |
307 | ||
308 | absnum--; | |
309 | ||
310 | /* Now absnum is always absolute and origin zero. */ | |
311 | ||
312 | chunk = value_history_chain; | |
313 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
314 | i > 0; i--) | |
315 | chunk = chunk->next; | |
316 | ||
317 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
318 | } | |
319 | ||
320 | /* Clear the value history entirely. | |
321 | Must be done when new symbol tables are loaded, | |
322 | because the type pointers become invalid. */ | |
323 | ||
324 | void | |
fba45db2 | 325 | clear_value_history (void) |
c906108c SS |
326 | { |
327 | register struct value_history_chunk *next; | |
328 | register int i; | |
329 | register value_ptr val; | |
330 | ||
331 | while (value_history_chain) | |
332 | { | |
333 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
334 | if ((val = value_history_chain->values[i]) != NULL) | |
b8c9b27d | 335 | xfree (val); |
c906108c | 336 | next = value_history_chain->next; |
b8c9b27d | 337 | xfree (value_history_chain); |
c906108c SS |
338 | value_history_chain = next; |
339 | } | |
340 | value_history_count = 0; | |
341 | } | |
342 | ||
343 | static void | |
fba45db2 | 344 | show_values (char *num_exp, int from_tty) |
c906108c SS |
345 | { |
346 | register int i; | |
347 | register value_ptr val; | |
348 | static int num = 1; | |
349 | ||
350 | if (num_exp) | |
351 | { | |
c5aa993b JM |
352 | /* "info history +" should print from the stored position. |
353 | "info history <exp>" should print around value number <exp>. */ | |
c906108c | 354 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 355 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
356 | } |
357 | else | |
358 | { | |
359 | /* "info history" means print the last 10 values. */ | |
360 | num = value_history_count - 9; | |
361 | } | |
362 | ||
363 | if (num <= 0) | |
364 | num = 1; | |
365 | ||
366 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
367 | { | |
368 | val = access_value_history (i); | |
369 | printf_filtered ("$%d = ", i); | |
370 | value_print (val, gdb_stdout, 0, Val_pretty_default); | |
371 | printf_filtered ("\n"); | |
372 | } | |
373 | ||
374 | /* The next "info history +" should start after what we just printed. */ | |
375 | num += 10; | |
376 | ||
377 | /* Hitting just return after this command should do the same thing as | |
378 | "info history +". If num_exp is null, this is unnecessary, since | |
379 | "info history +" is not useful after "info history". */ | |
380 | if (from_tty && num_exp) | |
381 | { | |
382 | num_exp[0] = '+'; | |
383 | num_exp[1] = '\0'; | |
384 | } | |
385 | } | |
386 | \f | |
387 | /* Internal variables. These are variables within the debugger | |
388 | that hold values assigned by debugger commands. | |
389 | The user refers to them with a '$' prefix | |
390 | that does not appear in the variable names stored internally. */ | |
391 | ||
392 | static struct internalvar *internalvars; | |
393 | ||
394 | /* Look up an internal variable with name NAME. NAME should not | |
395 | normally include a dollar sign. | |
396 | ||
397 | If the specified internal variable does not exist, | |
398 | one is created, with a void value. */ | |
399 | ||
400 | struct internalvar * | |
fba45db2 | 401 | lookup_internalvar (char *name) |
c906108c SS |
402 | { |
403 | register struct internalvar *var; | |
404 | ||
405 | for (var = internalvars; var; var = var->next) | |
406 | if (STREQ (var->name, name)) | |
407 | return var; | |
408 | ||
409 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); | |
410 | var->name = concat (name, NULL); | |
411 | var->value = allocate_value (builtin_type_void); | |
412 | release_value (var->value); | |
413 | var->next = internalvars; | |
414 | internalvars = var; | |
415 | return var; | |
416 | } | |
417 | ||
418 | value_ptr | |
fba45db2 | 419 | value_of_internalvar (struct internalvar *var) |
c906108c SS |
420 | { |
421 | register value_ptr val; | |
422 | ||
423 | #ifdef IS_TRAPPED_INTERNALVAR | |
424 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
425 | return VALUE_OF_TRAPPED_INTERNALVAR (var); | |
c5aa993b | 426 | #endif |
c906108c SS |
427 | |
428 | val = value_copy (var->value); | |
429 | if (VALUE_LAZY (val)) | |
430 | value_fetch_lazy (val); | |
431 | VALUE_LVAL (val) = lval_internalvar; | |
432 | VALUE_INTERNALVAR (val) = var; | |
433 | return val; | |
434 | } | |
435 | ||
436 | void | |
fba45db2 KB |
437 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
438 | int bitsize, value_ptr newval) | |
c906108c SS |
439 | { |
440 | register char *addr = VALUE_CONTENTS (var->value) + offset; | |
441 | ||
442 | #ifdef IS_TRAPPED_INTERNALVAR | |
443 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
444 | SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); | |
445 | #endif | |
446 | ||
447 | if (bitsize) | |
448 | modify_field (addr, value_as_long (newval), | |
449 | bitpos, bitsize); | |
450 | else | |
451 | memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval))); | |
452 | } | |
453 | ||
454 | void | |
fba45db2 | 455 | set_internalvar (struct internalvar *var, value_ptr val) |
c906108c SS |
456 | { |
457 | value_ptr newval; | |
458 | ||
459 | #ifdef IS_TRAPPED_INTERNALVAR | |
460 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
461 | SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); | |
462 | #endif | |
463 | ||
464 | newval = value_copy (val); | |
465 | newval->modifiable = 1; | |
466 | ||
467 | /* Force the value to be fetched from the target now, to avoid problems | |
468 | later when this internalvar is referenced and the target is gone or | |
469 | has changed. */ | |
470 | if (VALUE_LAZY (newval)) | |
471 | value_fetch_lazy (newval); | |
472 | ||
473 | /* Begin code which must not call error(). If var->value points to | |
474 | something free'd, an error() obviously leaves a dangling pointer. | |
475 | But we also get a danling pointer if var->value points to | |
476 | something in the value chain (i.e., before release_value is | |
477 | called), because after the error free_all_values will get called before | |
478 | long. */ | |
b8c9b27d | 479 | xfree (var->value); |
c906108c SS |
480 | var->value = newval; |
481 | release_value (newval); | |
482 | /* End code which must not call error(). */ | |
483 | } | |
484 | ||
485 | char * | |
fba45db2 | 486 | internalvar_name (struct internalvar *var) |
c906108c SS |
487 | { |
488 | return var->name; | |
489 | } | |
490 | ||
491 | /* Free all internalvars. Done when new symtabs are loaded, | |
492 | because that makes the values invalid. */ | |
493 | ||
494 | void | |
fba45db2 | 495 | clear_internalvars (void) |
c906108c SS |
496 | { |
497 | register struct internalvar *var; | |
498 | ||
499 | while (internalvars) | |
500 | { | |
501 | var = internalvars; | |
502 | internalvars = var->next; | |
b8c9b27d KB |
503 | xfree (var->name); |
504 | xfree (var->value); | |
505 | xfree (var); | |
c906108c SS |
506 | } |
507 | } | |
508 | ||
509 | static void | |
fba45db2 | 510 | show_convenience (char *ignore, int from_tty) |
c906108c SS |
511 | { |
512 | register struct internalvar *var; | |
513 | int varseen = 0; | |
514 | ||
515 | for (var = internalvars; var; var = var->next) | |
516 | { | |
517 | #ifdef IS_TRAPPED_INTERNALVAR | |
518 | if (IS_TRAPPED_INTERNALVAR (var->name)) | |
519 | continue; | |
520 | #endif | |
521 | if (!varseen) | |
522 | { | |
523 | varseen = 1; | |
524 | } | |
525 | printf_filtered ("$%s = ", var->name); | |
526 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); | |
527 | printf_filtered ("\n"); | |
528 | } | |
529 | if (!varseen) | |
530 | printf_unfiltered ("No debugger convenience variables now defined.\n\ | |
531 | Convenience variables have names starting with \"$\";\n\ | |
532 | use \"set\" as in \"set $foo = 5\" to define them.\n"); | |
533 | } | |
534 | \f | |
535 | /* Extract a value as a C number (either long or double). | |
536 | Knows how to convert fixed values to double, or | |
537 | floating values to long. | |
538 | Does not deallocate the value. */ | |
539 | ||
540 | LONGEST | |
fba45db2 | 541 | value_as_long (register value_ptr val) |
c906108c SS |
542 | { |
543 | /* This coerces arrays and functions, which is necessary (e.g. | |
544 | in disassemble_command). It also dereferences references, which | |
545 | I suspect is the most logical thing to do. */ | |
546 | COERCE_ARRAY (val); | |
547 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
548 | } | |
549 | ||
550 | DOUBLEST | |
fba45db2 | 551 | value_as_double (register value_ptr val) |
c906108c SS |
552 | { |
553 | DOUBLEST foo; | |
554 | int inv; | |
c5aa993b | 555 | |
c906108c SS |
556 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv); |
557 | if (inv) | |
558 | error ("Invalid floating value found in program."); | |
559 | return foo; | |
560 | } | |
4478b372 JB |
561 | /* Extract a value as a C pointer. Does not deallocate the value. |
562 | Note that val's type may not actually be a pointer; value_as_long | |
563 | handles all the cases. */ | |
c906108c | 564 | CORE_ADDR |
1aa20aa8 | 565 | value_as_address (value_ptr val) |
c906108c SS |
566 | { |
567 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
568 | whether we want this to be true eventually. */ | |
569 | #if 0 | |
570 | /* ADDR_BITS_REMOVE is wrong if we are being called for a | |
571 | non-address (e.g. argument to "signal", "info break", etc.), or | |
572 | for pointers to char, in which the low bits *are* significant. */ | |
c5aa993b | 573 | return ADDR_BITS_REMOVE (value_as_long (val)); |
c906108c | 574 | #else |
f312f057 JB |
575 | |
576 | /* There are several targets (IA-64, PowerPC, and others) which | |
577 | don't represent pointers to functions as simply the address of | |
578 | the function's entry point. For example, on the IA-64, a | |
579 | function pointer points to a two-word descriptor, generated by | |
580 | the linker, which contains the function's entry point, and the | |
581 | value the IA-64 "global pointer" register should have --- to | |
582 | support position-independent code. The linker generates | |
583 | descriptors only for those functions whose addresses are taken. | |
584 | ||
585 | On such targets, it's difficult for GDB to convert an arbitrary | |
586 | function address into a function pointer; it has to either find | |
587 | an existing descriptor for that function, or call malloc and | |
588 | build its own. On some targets, it is impossible for GDB to | |
589 | build a descriptor at all: the descriptor must contain a jump | |
590 | instruction; data memory cannot be executed; and code memory | |
591 | cannot be modified. | |
592 | ||
593 | Upon entry to this function, if VAL is a value of type `function' | |
594 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
595 | VALUE_ADDRESS (val) is the address of the function. This is what | |
596 | you'll get if you evaluate an expression like `main'. The call | |
597 | to COERCE_ARRAY below actually does all the usual unary | |
598 | conversions, which includes converting values of type `function' | |
599 | to `pointer to function'. This is the challenging conversion | |
600 | discussed above. Then, `unpack_long' will convert that pointer | |
601 | back into an address. | |
602 | ||
603 | So, suppose the user types `disassemble foo' on an architecture | |
604 | with a strange function pointer representation, on which GDB | |
605 | cannot build its own descriptors, and suppose further that `foo' | |
606 | has no linker-built descriptor. The address->pointer conversion | |
607 | will signal an error and prevent the command from running, even | |
608 | though the next step would have been to convert the pointer | |
609 | directly back into the same address. | |
610 | ||
611 | The following shortcut avoids this whole mess. If VAL is a | |
612 | function, just return its address directly. */ | |
613 | if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC | |
614 | || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_METHOD) | |
615 | return VALUE_ADDRESS (val); | |
616 | ||
67b2adb2 | 617 | COERCE_ARRAY (val); |
fc0c74b1 AC |
618 | |
619 | /* Some architectures (e.g. Harvard), map instruction and data | |
620 | addresses onto a single large unified address space. For | |
621 | instance: An architecture may consider a large integer in the | |
622 | range 0x10000000 .. 0x1000ffff to already represent a data | |
623 | addresses (hence not need a pointer to address conversion) while | |
624 | a small integer would still need to be converted integer to | |
625 | pointer to address. Just assume such architectures handle all | |
626 | integer conversions in a single function. */ | |
627 | ||
628 | /* JimB writes: | |
629 | ||
630 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
631 | must admonish GDB hackers to make sure its behavior matches the | |
632 | compiler's, whenever possible. | |
633 | ||
634 | In general, I think GDB should evaluate expressions the same way | |
635 | the compiler does. When the user copies an expression out of | |
636 | their source code and hands it to a `print' command, they should | |
637 | get the same value the compiler would have computed. Any | |
638 | deviation from this rule can cause major confusion and annoyance, | |
639 | and needs to be justified carefully. In other words, GDB doesn't | |
640 | really have the freedom to do these conversions in clever and | |
641 | useful ways. | |
642 | ||
643 | AndrewC pointed out that users aren't complaining about how GDB | |
644 | casts integers to pointers; they are complaining that they can't | |
645 | take an address from a disassembly listing and give it to `x/i'. | |
646 | This is certainly important. | |
647 | ||
648 | Adding an architecture method like INTEGER_TO_ADDRESS certainly | |
649 | makes it possible for GDB to "get it right" in all circumstances | |
650 | --- the target has complete control over how things get done, so | |
651 | people can Do The Right Thing for their target without breaking | |
652 | anyone else. The standard doesn't specify how integers get | |
653 | converted to pointers; usually, the ABI doesn't either, but | |
654 | ABI-specific code is a more reasonable place to handle it. */ | |
655 | ||
656 | if (TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_PTR | |
657 | && TYPE_CODE (VALUE_TYPE (val)) != TYPE_CODE_REF | |
658 | && INTEGER_TO_ADDRESS_P ()) | |
659 | return INTEGER_TO_ADDRESS (VALUE_TYPE (val), VALUE_CONTENTS (val)); | |
660 | ||
67b2adb2 | 661 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); |
c906108c SS |
662 | #endif |
663 | } | |
664 | \f | |
665 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
666 | as a long, or as a double, assuming the raw data is described | |
667 | by type TYPE. Knows how to convert different sizes of values | |
668 | and can convert between fixed and floating point. We don't assume | |
669 | any alignment for the raw data. Return value is in host byte order. | |
670 | ||
671 | If you want functions and arrays to be coerced to pointers, and | |
672 | references to be dereferenced, call value_as_long() instead. | |
673 | ||
674 | C++: It is assumed that the front-end has taken care of | |
675 | all matters concerning pointers to members. A pointer | |
676 | to member which reaches here is considered to be equivalent | |
677 | to an INT (or some size). After all, it is only an offset. */ | |
678 | ||
679 | LONGEST | |
fba45db2 | 680 | unpack_long (struct type *type, char *valaddr) |
c906108c SS |
681 | { |
682 | register enum type_code code = TYPE_CODE (type); | |
683 | register int len = TYPE_LENGTH (type); | |
684 | register int nosign = TYPE_UNSIGNED (type); | |
685 | ||
686 | if (current_language->la_language == language_scm | |
687 | && is_scmvalue_type (type)) | |
688 | return scm_unpack (type, valaddr, TYPE_CODE_INT); | |
689 | ||
690 | switch (code) | |
691 | { | |
692 | case TYPE_CODE_TYPEDEF: | |
693 | return unpack_long (check_typedef (type), valaddr); | |
694 | case TYPE_CODE_ENUM: | |
695 | case TYPE_CODE_BOOL: | |
696 | case TYPE_CODE_INT: | |
697 | case TYPE_CODE_CHAR: | |
698 | case TYPE_CODE_RANGE: | |
699 | if (nosign) | |
700 | return extract_unsigned_integer (valaddr, len); | |
701 | else | |
702 | return extract_signed_integer (valaddr, len); | |
703 | ||
704 | case TYPE_CODE_FLT: | |
96d2f608 | 705 | return extract_typed_floating (valaddr, type); |
c906108c SS |
706 | |
707 | case TYPE_CODE_PTR: | |
708 | case TYPE_CODE_REF: | |
709 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 710 | whether we want this to be true eventually. */ |
4478b372 | 711 | return extract_typed_address (valaddr, type); |
c906108c SS |
712 | |
713 | case TYPE_CODE_MEMBER: | |
714 | error ("not implemented: member types in unpack_long"); | |
715 | ||
716 | default: | |
717 | error ("Value can't be converted to integer."); | |
718 | } | |
c5aa993b | 719 | return 0; /* Placate lint. */ |
c906108c SS |
720 | } |
721 | ||
722 | /* Return a double value from the specified type and address. | |
723 | INVP points to an int which is set to 0 for valid value, | |
724 | 1 for invalid value (bad float format). In either case, | |
725 | the returned double is OK to use. Argument is in target | |
726 | format, result is in host format. */ | |
727 | ||
728 | DOUBLEST | |
fba45db2 | 729 | unpack_double (struct type *type, char *valaddr, int *invp) |
c906108c SS |
730 | { |
731 | enum type_code code; | |
732 | int len; | |
733 | int nosign; | |
734 | ||
735 | *invp = 0; /* Assume valid. */ | |
736 | CHECK_TYPEDEF (type); | |
737 | code = TYPE_CODE (type); | |
738 | len = TYPE_LENGTH (type); | |
739 | nosign = TYPE_UNSIGNED (type); | |
740 | if (code == TYPE_CODE_FLT) | |
741 | { | |
742 | #ifdef INVALID_FLOAT | |
743 | if (INVALID_FLOAT (valaddr, len)) | |
744 | { | |
745 | *invp = 1; | |
746 | return 1.234567891011121314; | |
747 | } | |
748 | #endif | |
96d2f608 | 749 | return extract_typed_floating (valaddr, type); |
c906108c SS |
750 | } |
751 | else if (nosign) | |
752 | { | |
753 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 754 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
755 | } |
756 | else | |
757 | { | |
758 | /* Signed -- we are OK with unpack_long. */ | |
759 | return unpack_long (type, valaddr); | |
760 | } | |
761 | } | |
762 | ||
763 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
764 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
765 | We don't assume any alignment for the raw data. Return value is in | |
766 | host byte order. | |
767 | ||
768 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 769 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
770 | |
771 | C++: It is assumed that the front-end has taken care of | |
772 | all matters concerning pointers to members. A pointer | |
773 | to member which reaches here is considered to be equivalent | |
774 | to an INT (or some size). After all, it is only an offset. */ | |
775 | ||
776 | CORE_ADDR | |
fba45db2 | 777 | unpack_pointer (struct type *type, char *valaddr) |
c906108c SS |
778 | { |
779 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
780 | whether we want this to be true eventually. */ | |
781 | return unpack_long (type, valaddr); | |
782 | } | |
4478b372 | 783 | |
c906108c SS |
784 | \f |
785 | /* Get the value of the FIELDN'th field (which must be static) of TYPE. */ | |
786 | ||
787 | value_ptr | |
fba45db2 | 788 | value_static_field (struct type *type, int fieldno) |
c906108c SS |
789 | { |
790 | CORE_ADDR addr; | |
791 | asection *sect; | |
792 | if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) | |
793 | { | |
794 | addr = TYPE_FIELD_STATIC_PHYSADDR (type, fieldno); | |
795 | sect = NULL; | |
796 | } | |
797 | else | |
798 | { | |
799 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
800 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL); | |
801 | if (sym == NULL) | |
802 | { | |
803 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
804 | as non-debuggable symbols */ |
805 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
806 | if (!msym) |
807 | return NULL; | |
808 | else | |
c5aa993b | 809 | { |
c906108c SS |
810 | addr = SYMBOL_VALUE_ADDRESS (msym); |
811 | sect = SYMBOL_BFD_SECTION (msym); | |
812 | } | |
813 | } | |
814 | else | |
815 | { | |
2b127877 DB |
816 | /* Anything static that isn't a constant, has an address */ |
817 | if (SYMBOL_CLASS (sym) != LOC_CONST) | |
818 | { | |
819 | addr = SYMBOL_VALUE_ADDRESS (sym); | |
820 | sect = SYMBOL_BFD_SECTION (sym); | |
821 | } | |
822 | /* However, static const's do not, the value is already known. */ | |
823 | else | |
824 | { | |
825 | return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), SYMBOL_VALUE (sym)); | |
826 | } | |
827 | } | |
c906108c SS |
828 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), addr); |
829 | } | |
830 | return value_at (TYPE_FIELD_TYPE (type, fieldno), addr, sect); | |
831 | } | |
832 | ||
2b127877 DB |
833 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
834 | You have to be careful here, since the size of the data area for the value | |
835 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
836 | than the old enclosing type, you have to allocate more space for the data. | |
837 | The return value is a pointer to the new version of this value structure. */ | |
838 | ||
839 | value_ptr | |
840 | value_change_enclosing_type (value_ptr val, struct type *new_encl_type) | |
841 | { | |
842 | if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val))) | |
843 | { | |
844 | VALUE_ENCLOSING_TYPE (val) = new_encl_type; | |
845 | return val; | |
846 | } | |
847 | else | |
848 | { | |
849 | value_ptr new_val; | |
850 | register value_ptr prev; | |
851 | ||
852 | new_val = (value_ptr) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); | |
853 | ||
854 | /* We have to make sure this ends up in the same place in the value | |
855 | chain as the original copy, so it's clean-up behavior is the same. | |
856 | If the value has been released, this is a waste of time, but there | |
857 | is no way to tell that in advance, so... */ | |
858 | ||
859 | if (val != all_values) | |
860 | { | |
861 | for (prev = all_values; prev != NULL; prev = prev->next) | |
862 | { | |
863 | if (prev->next == val) | |
864 | { | |
865 | prev->next = new_val; | |
866 | break; | |
867 | } | |
868 | } | |
869 | } | |
870 | ||
871 | return new_val; | |
872 | } | |
873 | } | |
874 | ||
c906108c SS |
875 | /* Given a value ARG1 (offset by OFFSET bytes) |
876 | of a struct or union type ARG_TYPE, | |
877 | extract and return the value of one of its (non-static) fields. | |
878 | FIELDNO says which field. */ | |
879 | ||
880 | value_ptr | |
fba45db2 KB |
881 | value_primitive_field (register value_ptr arg1, int offset, |
882 | register int fieldno, register struct type *arg_type) | |
c906108c SS |
883 | { |
884 | register value_ptr v; | |
885 | register struct type *type; | |
886 | ||
887 | CHECK_TYPEDEF (arg_type); | |
888 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
889 | ||
890 | /* Handle packed fields */ | |
891 | ||
892 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
893 | { | |
894 | v = value_from_longest (type, | |
895 | unpack_field_as_long (arg_type, | |
896 | VALUE_CONTENTS (arg1) | |
c5aa993b | 897 | + offset, |
c906108c SS |
898 | fieldno)); |
899 | VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; | |
900 | VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
2e70b7b9 MS |
901 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
902 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
903 | } |
904 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
905 | { | |
906 | /* This field is actually a base subobject, so preserve the | |
907 | entire object's contents for later references to virtual | |
908 | bases, etc. */ | |
909 | v = allocate_value (VALUE_ENCLOSING_TYPE (arg1)); | |
8d65888a | 910 | VALUE_TYPE (v) = type; |
c906108c SS |
911 | if (VALUE_LAZY (arg1)) |
912 | VALUE_LAZY (v) = 1; | |
913 | else | |
914 | memcpy (VALUE_CONTENTS_ALL_RAW (v), VALUE_CONTENTS_ALL_RAW (arg1), | |
915 | TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1))); | |
916 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1); | |
917 | VALUE_EMBEDDED_OFFSET (v) | |
c5aa993b JM |
918 | = offset + |
919 | VALUE_EMBEDDED_OFFSET (arg1) + | |
920 | TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
c906108c SS |
921 | } |
922 | else | |
923 | { | |
924 | /* Plain old data member */ | |
925 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
926 | v = allocate_value (type); | |
927 | if (VALUE_LAZY (arg1)) | |
928 | VALUE_LAZY (v) = 1; | |
929 | else | |
930 | memcpy (VALUE_CONTENTS_RAW (v), | |
931 | VALUE_CONTENTS_RAW (arg1) + offset, | |
932 | TYPE_LENGTH (type)); | |
21cfb3b6 DJ |
933 | VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
934 | + VALUE_EMBEDDED_OFFSET (arg1); | |
c906108c SS |
935 | } |
936 | VALUE_LVAL (v) = VALUE_LVAL (arg1); | |
937 | if (VALUE_LVAL (arg1) == lval_internalvar) | |
938 | VALUE_LVAL (v) = lval_internalvar_component; | |
939 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); | |
a88c1392 | 940 | VALUE_REGNO (v) = VALUE_REGNO (arg1); |
c906108c | 941 | /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
c5aa993b | 942 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ |
c906108c SS |
943 | return v; |
944 | } | |
945 | ||
946 | /* Given a value ARG1 of a struct or union type, | |
947 | extract and return the value of one of its (non-static) fields. | |
948 | FIELDNO says which field. */ | |
949 | ||
950 | value_ptr | |
fba45db2 | 951 | value_field (register value_ptr arg1, register int fieldno) |
c906108c SS |
952 | { |
953 | return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1)); | |
954 | } | |
955 | ||
956 | /* Return a non-virtual function as a value. | |
957 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
958 | J is an index into F which provides the desired method. |
959 | ||
960 | We only use the symbol for its address, so be happy with either a | |
961 | full symbol or a minimal symbol. | |
962 | */ | |
c906108c SS |
963 | |
964 | value_ptr | |
fba45db2 KB |
965 | value_fn_field (value_ptr *arg1p, struct fn_field *f, int j, struct type *type, |
966 | int offset) | |
c906108c SS |
967 | { |
968 | register value_ptr v; | |
969 | register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); | |
0478d61c | 970 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 971 | struct symbol *sym; |
0478d61c | 972 | struct minimal_symbol *msym; |
c906108c | 973 | |
0478d61c | 974 | sym = lookup_symbol (physname, 0, VAR_NAMESPACE, 0, NULL); |
5ae326fa | 975 | if (sym != NULL) |
0478d61c | 976 | { |
5ae326fa AC |
977 | msym = NULL; |
978 | } | |
979 | else | |
980 | { | |
981 | gdb_assert (sym == NULL); | |
0478d61c | 982 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
983 | if (msym == NULL) |
984 | return NULL; | |
0478d61c FF |
985 | } |
986 | ||
c906108c | 987 | v = allocate_value (ftype); |
0478d61c FF |
988 | if (sym) |
989 | { | |
990 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
991 | } | |
992 | else | |
993 | { | |
994 | VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); | |
995 | } | |
c906108c SS |
996 | |
997 | if (arg1p) | |
c5aa993b JM |
998 | { |
999 | if (type != VALUE_TYPE (*arg1p)) | |
1000 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), | |
1001 | value_addr (*arg1p))); | |
1002 | ||
070ad9f0 | 1003 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1004 | VALUE_OFFSET (*arg1p) += offset; |
1005 | */ | |
c906108c SS |
1006 | } |
1007 | ||
1008 | return v; | |
1009 | } | |
1010 | ||
c906108c SS |
1011 | /* ARG is a pointer to an object we know to be at least |
1012 | a DTYPE. BTYPE is the most derived basetype that has | |
1013 | already been searched (and need not be searched again). | |
1014 | After looking at the vtables between BTYPE and DTYPE, | |
1015 | return the most derived type we find. The caller must | |
1016 | be satisfied when the return value == DTYPE. | |
1017 | ||
070ad9f0 DB |
1018 | FIXME-tiemann: should work with dossier entries as well. |
1019 | NOTICE - djb: I see no good reason at all to keep this function now that | |
1020 | we have RTTI support. It's used in literally one place, and it's | |
1021 | hard to keep this function up to date when it's purpose is served | |
1022 | by value_rtti_type efficiently. | |
1023 | Consider it gone for 5.1. */ | |
c906108c SS |
1024 | |
1025 | static value_ptr | |
fba45db2 | 1026 | value_headof (value_ptr in_arg, struct type *btype, struct type *dtype) |
c906108c SS |
1027 | { |
1028 | /* First collect the vtables we must look at for this object. */ | |
070ad9f0 | 1029 | value_ptr arg, vtbl; |
c906108c | 1030 | struct symbol *sym; |
c906108c SS |
1031 | char *demangled_name; |
1032 | struct minimal_symbol *msymbol; | |
1033 | ||
1034 | btype = TYPE_VPTR_BASETYPE (dtype); | |
1035 | CHECK_TYPEDEF (btype); | |
1036 | arg = in_arg; | |
1037 | if (btype != dtype) | |
070ad9f0 DB |
1038 | arg = value_cast (lookup_pointer_type (btype), arg); |
1039 | if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF) | |
1040 | { | |
1041 | /* | |
1042 | * Copy the value, but change the type from (T&) to (T*). | |
1043 | * We keep the same location information, which is efficient, | |
1044 | * and allows &(&X) to get the location containing the reference. | |
1045 | */ | |
1046 | arg = value_copy (arg); | |
1047 | VALUE_TYPE (arg) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg))); | |
1048 | } | |
1049 | if (VALUE_ADDRESS(value_field (value_ind(arg), TYPE_VPTR_FIELDNO (btype)))==0) | |
1050 | return arg; | |
1051 | ||
c906108c | 1052 | vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype))); |
070ad9f0 DB |
1053 | /* Turn vtable into typeinfo function */ |
1054 | VALUE_OFFSET(vtbl)+=4; | |
c906108c | 1055 | |
1aa20aa8 | 1056 | msymbol = lookup_minimal_symbol_by_pc ( value_as_address(value_ind(vtbl)) ); |
c906108c | 1057 | if (msymbol == NULL |
070ad9f0 DB |
1058 | || (demangled_name = SYMBOL_NAME (msymbol)) == NULL) |
1059 | { | |
1060 | /* If we expected to find a vtable, but did not, let the user | |
1061 | know that we aren't happy, but don't throw an error. | |
1062 | FIXME: there has to be a better way to do this. */ | |
1063 | struct type *error_type = (struct type *) xmalloc (sizeof (struct type)); | |
1064 | memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type)); | |
1065 | TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *")); | |
1066 | VALUE_TYPE (in_arg) = error_type; | |
1067 | return in_arg; | |
1068 | } | |
1069 | demangled_name = cplus_demangle(demangled_name,DMGL_ANSI); | |
1070 | *(strchr (demangled_name, ' ')) = '\0'; | |
c906108c | 1071 | |
c906108c SS |
1072 | sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0); |
1073 | if (sym == NULL) | |
070ad9f0 DB |
1074 | error ("could not find type declaration for `%s'", demangled_name); |
1075 | ||
1076 | arg = in_arg; | |
c906108c SS |
1077 | VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym)); |
1078 | return arg; | |
1079 | } | |
1080 | ||
1081 | /* ARG is a pointer object of type TYPE. If TYPE has virtual | |
1082 | function tables, probe ARG's tables (including the vtables | |
1083 | of its baseclasses) to figure out the most derived type that ARG | |
1084 | could actually be a pointer to. */ | |
1085 | ||
1086 | value_ptr | |
fba45db2 | 1087 | value_from_vtable_info (value_ptr arg, struct type *type) |
c906108c SS |
1088 | { |
1089 | /* Take care of preliminaries. */ | |
1090 | if (TYPE_VPTR_FIELDNO (type) < 0) | |
1091 | fill_in_vptr_fieldno (type); | |
1092 | if (TYPE_VPTR_FIELDNO (type) < 0) | |
1093 | return 0; | |
1094 | ||
1095 | return value_headof (arg, 0, type); | |
1096 | } | |
1097 | ||
1098 | /* Return true if the INDEXth field of TYPE is a virtual baseclass | |
1099 | pointer which is for the base class whose type is BASECLASS. */ | |
1100 | ||
1101 | static int | |
fba45db2 | 1102 | vb_match (struct type *type, int index, struct type *basetype) |
c906108c SS |
1103 | { |
1104 | struct type *fieldtype; | |
1105 | char *name = TYPE_FIELD_NAME (type, index); | |
1106 | char *field_class_name = NULL; | |
1107 | ||
1108 | if (*name != '_') | |
1109 | return 0; | |
1110 | /* gcc 2.4 uses _vb$. */ | |
1111 | if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3])) | |
1112 | field_class_name = name + 4; | |
1113 | /* gcc 2.5 will use __vb_. */ | |
1114 | if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_') | |
1115 | field_class_name = name + 5; | |
1116 | ||
1117 | if (field_class_name == NULL) | |
1118 | /* This field is not a virtual base class pointer. */ | |
1119 | return 0; | |
1120 | ||
1121 | /* It's a virtual baseclass pointer, now we just need to find out whether | |
1122 | it is for this baseclass. */ | |
1123 | fieldtype = TYPE_FIELD_TYPE (type, index); | |
1124 | if (fieldtype == NULL | |
1125 | || TYPE_CODE (fieldtype) != TYPE_CODE_PTR) | |
1126 | /* "Can't happen". */ | |
1127 | return 0; | |
1128 | ||
1129 | /* What we check for is that either the types are equal (needed for | |
1130 | nameless types) or have the same name. This is ugly, and a more | |
1131 | elegant solution should be devised (which would probably just push | |
1132 | the ugliness into symbol reading unless we change the stabs format). */ | |
1133 | if (TYPE_TARGET_TYPE (fieldtype) == basetype) | |
1134 | return 1; | |
1135 | ||
1136 | if (TYPE_NAME (basetype) != NULL | |
1137 | && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL | |
1138 | && STREQ (TYPE_NAME (basetype), | |
1139 | TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)))) | |
1140 | return 1; | |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | /* Compute the offset of the baseclass which is | |
1145 | the INDEXth baseclass of class TYPE, | |
1146 | for value at VALADDR (in host) at ADDRESS (in target). | |
1147 | The result is the offset of the baseclass value relative | |
1148 | to (the address of)(ARG) + OFFSET. | |
1149 | ||
1150 | -1 is returned on error. */ | |
1151 | ||
1152 | int | |
fba45db2 KB |
1153 | baseclass_offset (struct type *type, int index, char *valaddr, |
1154 | CORE_ADDR address) | |
c906108c SS |
1155 | { |
1156 | struct type *basetype = TYPE_BASECLASS (type, index); | |
1157 | ||
1158 | if (BASETYPE_VIA_VIRTUAL (type, index)) | |
1159 | { | |
1160 | /* Must hunt for the pointer to this virtual baseclass. */ | |
1161 | register int i, len = TYPE_NFIELDS (type); | |
1162 | register int n_baseclasses = TYPE_N_BASECLASSES (type); | |
1163 | ||
1164 | /* First look for the virtual baseclass pointer | |
c5aa993b | 1165 | in the fields. */ |
c906108c SS |
1166 | for (i = n_baseclasses; i < len; i++) |
1167 | { | |
1168 | if (vb_match (type, i, basetype)) | |
1169 | { | |
1170 | CORE_ADDR addr | |
c5aa993b JM |
1171 | = unpack_pointer (TYPE_FIELD_TYPE (type, i), |
1172 | valaddr + (TYPE_FIELD_BITPOS (type, i) / 8)); | |
c906108c SS |
1173 | |
1174 | return addr - (LONGEST) address; | |
1175 | } | |
1176 | } | |
1177 | /* Not in the fields, so try looking through the baseclasses. */ | |
c5aa993b | 1178 | for (i = index + 1; i < n_baseclasses; i++) |
c906108c SS |
1179 | { |
1180 | int boffset = | |
c5aa993b | 1181 | baseclass_offset (type, i, valaddr, address); |
c906108c SS |
1182 | if (boffset) |
1183 | return boffset; | |
1184 | } | |
1185 | /* Not found. */ | |
1186 | return -1; | |
1187 | } | |
1188 | ||
1189 | /* Baseclass is easily computed. */ | |
1190 | return TYPE_BASECLASS_BITPOS (type, index) / 8; | |
1191 | } | |
1192 | \f | |
1193 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1194 | VALADDR. | |
1195 | ||
1196 | Extracting bits depends on endianness of the machine. Compute the | |
1197 | number of least significant bits to discard. For big endian machines, | |
1198 | we compute the total number of bits in the anonymous object, subtract | |
1199 | off the bit count from the MSB of the object to the MSB of the | |
1200 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1201 | count. For little endian machines, the discard count is simply the | |
1202 | number of bits from the LSB of the anonymous object to the LSB of the | |
1203 | bitfield. | |
1204 | ||
1205 | If the field is signed, we also do sign extension. */ | |
1206 | ||
1207 | LONGEST | |
fba45db2 | 1208 | unpack_field_as_long (struct type *type, char *valaddr, int fieldno) |
c906108c SS |
1209 | { |
1210 | ULONGEST val; | |
1211 | ULONGEST valmask; | |
1212 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1213 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1214 | int lsbcount; | |
1215 | struct type *field_type; | |
1216 | ||
1217 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1218 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1219 | CHECK_TYPEDEF (field_type); | |
1220 | ||
1221 | /* Extract bits. See comment above. */ | |
1222 | ||
1223 | if (BITS_BIG_ENDIAN) | |
1224 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); | |
1225 | else | |
1226 | lsbcount = (bitpos % 8); | |
1227 | val >>= lsbcount; | |
1228 | ||
1229 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1230 | If the field is signed, and is negative, then sign extend. */ | |
1231 | ||
1232 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1233 | { | |
1234 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1235 | val &= valmask; | |
1236 | if (!TYPE_UNSIGNED (field_type)) | |
1237 | { | |
1238 | if (val & (valmask ^ (valmask >> 1))) | |
1239 | { | |
1240 | val |= ~valmask; | |
1241 | } | |
1242 | } | |
1243 | } | |
1244 | return (val); | |
1245 | } | |
1246 | ||
1247 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1248 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1249 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
1250 | indicate which bits (in target bit order) comprise the bitfield. */ | |
1251 | ||
1252 | void | |
fba45db2 | 1253 | modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c SS |
1254 | { |
1255 | LONGEST oword; | |
1256 | ||
1257 | /* If a negative fieldval fits in the field in question, chop | |
1258 | off the sign extension bits. */ | |
1259 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
1260 | && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) | |
1261 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1262 | ||
1263 | /* Warn if value is too big to fit in the field in question. */ | |
1264 | if (bitsize < (8 * (int) sizeof (fieldval)) | |
c5aa993b | 1265 | && 0 != (fieldval & ~((1 << bitsize) - 1))) |
c906108c SS |
1266 | { |
1267 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1268 | we don't have a sprintf_longest. */ |
c906108c SS |
1269 | warning ("Value does not fit in %d bits.", bitsize); |
1270 | ||
1271 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
1272 | fieldval = fieldval & ((1 << bitsize) - 1); | |
1273 | } | |
1274 | ||
1275 | oword = extract_signed_integer (addr, sizeof oword); | |
1276 | ||
1277 | /* Shifting for bit field depends on endianness of the target machine. */ | |
1278 | if (BITS_BIG_ENDIAN) | |
1279 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; | |
1280 | ||
1281 | /* Mask out old value, while avoiding shifts >= size of oword */ | |
1282 | if (bitsize < 8 * (int) sizeof (oword)) | |
c5aa993b | 1283 | oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos); |
c906108c | 1284 | else |
c5aa993b | 1285 | oword &= ~((~(ULONGEST) 0) << bitpos); |
c906108c SS |
1286 | oword |= fieldval << bitpos; |
1287 | ||
1288 | store_signed_integer (addr, sizeof oword, oword); | |
1289 | } | |
1290 | \f | |
1291 | /* Convert C numbers into newly allocated values */ | |
1292 | ||
1293 | value_ptr | |
fba45db2 | 1294 | value_from_longest (struct type *type, register LONGEST num) |
c906108c SS |
1295 | { |
1296 | register value_ptr val = allocate_value (type); | |
1297 | register enum type_code code; | |
1298 | register int len; | |
c5aa993b | 1299 | retry: |
c906108c SS |
1300 | code = TYPE_CODE (type); |
1301 | len = TYPE_LENGTH (type); | |
1302 | ||
1303 | switch (code) | |
1304 | { | |
1305 | case TYPE_CODE_TYPEDEF: | |
1306 | type = check_typedef (type); | |
1307 | goto retry; | |
1308 | case TYPE_CODE_INT: | |
1309 | case TYPE_CODE_CHAR: | |
1310 | case TYPE_CODE_ENUM: | |
1311 | case TYPE_CODE_BOOL: | |
1312 | case TYPE_CODE_RANGE: | |
1313 | store_signed_integer (VALUE_CONTENTS_RAW (val), len, num); | |
1314 | break; | |
c5aa993b | 1315 | |
c906108c SS |
1316 | case TYPE_CODE_REF: |
1317 | case TYPE_CODE_PTR: | |
4478b372 | 1318 | store_typed_address (VALUE_CONTENTS_RAW (val), type, (CORE_ADDR) num); |
c906108c | 1319 | break; |
c5aa993b | 1320 | |
c906108c SS |
1321 | default: |
1322 | error ("Unexpected type (%d) encountered for integer constant.", code); | |
1323 | } | |
1324 | return val; | |
1325 | } | |
1326 | ||
4478b372 JB |
1327 | |
1328 | /* Create a value representing a pointer of type TYPE to the address | |
1329 | ADDR. */ | |
1330 | value_ptr | |
1331 | value_from_pointer (struct type *type, CORE_ADDR addr) | |
1332 | { | |
1333 | value_ptr val = allocate_value (type); | |
1334 | store_typed_address (VALUE_CONTENTS_RAW (val), type, addr); | |
1335 | return val; | |
1336 | } | |
1337 | ||
1338 | ||
0f71a2f6 | 1339 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1340 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1341 | This is analogous to value_from_longest, which also does not |
1342 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1343 | ||
1344 | value_ptr | |
fba45db2 | 1345 | value_from_string (char *ptr) |
0f71a2f6 JM |
1346 | { |
1347 | value_ptr val; | |
c5aa993b | 1348 | int len = strlen (ptr); |
0f71a2f6 | 1349 | int lowbound = current_language->string_lower_bound; |
c5aa993b JM |
1350 | struct type *rangetype = |
1351 | create_range_type ((struct type *) NULL, | |
1352 | builtin_type_int, | |
1353 | lowbound, len + lowbound - 1); | |
1354 | struct type *stringtype = | |
1355 | create_array_type ((struct type *) NULL, | |
1356 | *current_language->string_char_type, | |
1357 | rangetype); | |
0f71a2f6 JM |
1358 | |
1359 | val = allocate_value (stringtype); | |
1360 | memcpy (VALUE_CONTENTS_RAW (val), ptr, len); | |
1361 | return val; | |
1362 | } | |
1363 | ||
c906108c | 1364 | value_ptr |
fba45db2 | 1365 | value_from_double (struct type *type, DOUBLEST num) |
c906108c SS |
1366 | { |
1367 | register value_ptr val = allocate_value (type); | |
1368 | struct type *base_type = check_typedef (type); | |
1369 | register enum type_code code = TYPE_CODE (base_type); | |
1370 | register int len = TYPE_LENGTH (base_type); | |
1371 | ||
1372 | if (code == TYPE_CODE_FLT) | |
1373 | { | |
96d2f608 | 1374 | store_typed_floating (VALUE_CONTENTS_RAW (val), base_type, num); |
c906108c SS |
1375 | } |
1376 | else | |
1377 | error ("Unexpected type encountered for floating constant."); | |
1378 | ||
1379 | return val; | |
1380 | } | |
1381 | \f | |
1382 | /* Deal with the value that is "about to be returned". */ | |
1383 | ||
1384 | /* Return the value that a function returning now | |
1385 | would be returning to its caller, assuming its type is VALTYPE. | |
1386 | RETBUF is where we look for what ought to be the contents | |
1387 | of the registers (in raw form). This is because it is often | |
1388 | desirable to restore old values to those registers | |
1389 | after saving the contents of interest, and then call | |
1390 | this function using the saved values. | |
1391 | struct_return is non-zero when the function in question is | |
1392 | using the structure return conventions on the machine in question; | |
1393 | 0 when it is using the value returning conventions (this often | |
1394 | means returning pointer to where structure is vs. returning value). */ | |
1395 | ||
1669605f | 1396 | /* ARGSUSED */ |
c906108c | 1397 | value_ptr |
1669605f | 1398 | value_being_returned (struct type *valtype, char *retbuf, int struct_return) |
c906108c SS |
1399 | { |
1400 | register value_ptr val; | |
1401 | CORE_ADDR addr; | |
1402 | ||
c906108c | 1403 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ |
d6dd581e | 1404 | if (EXTRACT_STRUCT_VALUE_ADDRESS_P ()) |
ac9a91a7 JM |
1405 | if (struct_return) |
1406 | { | |
1407 | addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf); | |
1408 | if (!addr) | |
aead120c | 1409 | error ("Function return value unknown."); |
ac9a91a7 JM |
1410 | return value_at (valtype, addr, NULL); |
1411 | } | |
c906108c SS |
1412 | |
1413 | val = allocate_value (valtype); | |
1414 | CHECK_TYPEDEF (valtype); | |
1415 | EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val)); | |
1416 | ||
1417 | return val; | |
1418 | } | |
1419 | ||
1420 | /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of | |
1421 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc | |
1422 | and TYPE is the type (which is known to be struct, union or array). | |
1423 | ||
1424 | On most machines, the struct convention is used unless we are | |
1425 | using gcc and the type is of a special size. */ | |
1426 | /* As of about 31 Mar 93, GCC was changed to be compatible with the | |
1427 | native compiler. GCC 2.3.3 was the last release that did it the | |
1428 | old way. Since gcc2_compiled was not changed, we have no | |
1429 | way to correctly win in all cases, so we just do the right thing | |
1430 | for gcc1 and for gcc2 after this change. Thus it loses for gcc | |
1431 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled | |
1432 | would cause more chaos than dealing with some struct returns being | |
1433 | handled wrong. */ | |
1434 | ||
1435 | int | |
fba45db2 | 1436 | generic_use_struct_convention (int gcc_p, struct type *value_type) |
c5aa993b | 1437 | { |
c906108c | 1438 | return !((gcc_p == 1) |
c5aa993b JM |
1439 | && (TYPE_LENGTH (value_type) == 1 |
1440 | || TYPE_LENGTH (value_type) == 2 | |
1441 | || TYPE_LENGTH (value_type) == 4 | |
1442 | || TYPE_LENGTH (value_type) == 8)); | |
c906108c SS |
1443 | } |
1444 | ||
c906108c SS |
1445 | /* Return true if the function specified is using the structure returning |
1446 | convention on this machine to return arguments, or 0 if it is using | |
1447 | the value returning convention. FUNCTION is the value representing | |
1448 | the function, FUNCADDR is the address of the function, and VALUE_TYPE | |
1449 | is the type returned by the function. GCC_P is nonzero if compiled | |
1450 | with GCC. */ | |
1451 | ||
1669605f | 1452 | /* ARGSUSED */ |
c906108c | 1453 | int |
1669605f KB |
1454 | using_struct_return (value_ptr function, CORE_ADDR funcaddr, |
1455 | struct type *value_type, int gcc_p) | |
c906108c SS |
1456 | { |
1457 | register enum type_code code = TYPE_CODE (value_type); | |
1458 | ||
1459 | if (code == TYPE_CODE_ERROR) | |
1460 | error ("Function return type unknown."); | |
1461 | ||
1462 | if (code == TYPE_CODE_STRUCT | |
1463 | || code == TYPE_CODE_UNION | |
1464 | || code == TYPE_CODE_ARRAY | |
1465 | || RETURN_VALUE_ON_STACK (value_type)) | |
1466 | return USE_STRUCT_CONVENTION (gcc_p, value_type); | |
1467 | ||
1468 | return 0; | |
1469 | } | |
1470 | ||
1471 | /* Store VAL so it will be returned if a function returns now. | |
1472 | Does not verify that VAL's type matches what the current | |
1473 | function wants to return. */ | |
1474 | ||
1475 | void | |
fba45db2 | 1476 | set_return_value (value_ptr val) |
c906108c SS |
1477 | { |
1478 | struct type *type = check_typedef (VALUE_TYPE (val)); | |
1479 | register enum type_code code = TYPE_CODE (type); | |
1480 | ||
1481 | if (code == TYPE_CODE_ERROR) | |
1482 | error ("Function return type unknown."); | |
1483 | ||
c5aa993b | 1484 | if (code == TYPE_CODE_STRUCT |
c906108c SS |
1485 | || code == TYPE_CODE_UNION) /* FIXME, implement struct return. */ |
1486 | error ("GDB does not support specifying a struct or union return value."); | |
1487 | ||
1488 | STORE_RETURN_VALUE (type, VALUE_CONTENTS (val)); | |
1489 | } | |
1490 | \f | |
1491 | void | |
fba45db2 | 1492 | _initialize_values (void) |
c906108c SS |
1493 | { |
1494 | add_cmd ("convenience", no_class, show_convenience, | |
c5aa993b | 1495 | "Debugger convenience (\"$foo\") variables.\n\ |
c906108c SS |
1496 | These variables are created when you assign them values;\n\ |
1497 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ | |
1498 | A few convenience variables are given values automatically:\n\ | |
1499 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1500 | \"$__\" holds the contents of the last address examined with \"x\".", | |
1501 | &showlist); | |
1502 | ||
1503 | add_cmd ("values", no_class, show_values, | |
1504 | "Elements of value history around item number IDX (or last ten).", | |
1505 | &showlist); | |
1506 | } |