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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
1bac305b | 2 | |
6aba47ca | 3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
0fb0cc75 JB |
4 | 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, |
5 | 2009 Free Software Foundation, Inc. | |
c906108c | 6 | |
c5aa993b | 7 | This file is part of GDB. |
c906108c | 8 | |
c5aa993b JM |
9 | This program is free software; you can redistribute it and/or modify |
10 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 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 | 19 | You should have received a copy of the GNU General Public License |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c SS |
21 | |
22 | #include "defs.h" | |
23 | #include "gdb_string.h" | |
24 | #include "symtab.h" | |
25 | #include "gdbtypes.h" | |
26 | #include "value.h" | |
27 | #include "gdbcore.h" | |
c906108c SS |
28 | #include "command.h" |
29 | #include "gdbcmd.h" | |
30 | #include "target.h" | |
31 | #include "language.h" | |
c906108c | 32 | #include "demangle.h" |
d16aafd8 | 33 | #include "doublest.h" |
5ae326fa | 34 | #include "gdb_assert.h" |
36160dc4 | 35 | #include "regcache.h" |
fe898f56 | 36 | #include "block.h" |
27bc4d80 | 37 | #include "dfp.h" |
bccdca4a | 38 | #include "objfiles.h" |
79a45b7d | 39 | #include "valprint.h" |
c906108c | 40 | |
a08702d6 TJB |
41 | #include "python/python.h" |
42 | ||
c906108c SS |
43 | /* Prototypes for exported functions. */ |
44 | ||
a14ed312 | 45 | void _initialize_values (void); |
c906108c | 46 | |
91294c83 AC |
47 | struct value |
48 | { | |
49 | /* Type of value; either not an lval, or one of the various | |
50 | different possible kinds of lval. */ | |
51 | enum lval_type lval; | |
52 | ||
53 | /* Is it modifiable? Only relevant if lval != not_lval. */ | |
54 | int modifiable; | |
55 | ||
56 | /* Location of value (if lval). */ | |
57 | union | |
58 | { | |
59 | /* If lval == lval_memory, this is the address in the inferior. | |
60 | If lval == lval_register, this is the byte offset into the | |
61 | registers structure. */ | |
62 | CORE_ADDR address; | |
63 | ||
64 | /* Pointer to internal variable. */ | |
65 | struct internalvar *internalvar; | |
5f5233d4 PA |
66 | |
67 | /* If lval == lval_computed, this is a set of function pointers | |
68 | to use to access and describe the value, and a closure pointer | |
69 | for them to use. */ | |
70 | struct | |
71 | { | |
72 | struct lval_funcs *funcs; /* Functions to call. */ | |
73 | void *closure; /* Closure for those functions to use. */ | |
74 | } computed; | |
91294c83 AC |
75 | } location; |
76 | ||
77 | /* Describes offset of a value within lval of a structure in bytes. | |
78 | If lval == lval_memory, this is an offset to the address. If | |
79 | lval == lval_register, this is a further offset from | |
80 | location.address within the registers structure. Note also the | |
81 | member embedded_offset below. */ | |
82 | int offset; | |
83 | ||
84 | /* Only used for bitfields; number of bits contained in them. */ | |
85 | int bitsize; | |
86 | ||
87 | /* Only used for bitfields; position of start of field. For | |
32c9a795 MD |
88 | gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For |
89 | gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */ | |
91294c83 AC |
90 | int bitpos; |
91 | ||
92 | /* Frame register value is relative to. This will be described in | |
93 | the lval enum above as "lval_register". */ | |
94 | struct frame_id frame_id; | |
95 | ||
96 | /* Type of the value. */ | |
97 | struct type *type; | |
98 | ||
99 | /* If a value represents a C++ object, then the `type' field gives | |
100 | the object's compile-time type. If the object actually belongs | |
101 | to some class derived from `type', perhaps with other base | |
102 | classes and additional members, then `type' is just a subobject | |
103 | of the real thing, and the full object is probably larger than | |
104 | `type' would suggest. | |
105 | ||
106 | If `type' is a dynamic class (i.e. one with a vtable), then GDB | |
107 | can actually determine the object's run-time type by looking at | |
108 | the run-time type information in the vtable. When this | |
109 | information is available, we may elect to read in the entire | |
110 | object, for several reasons: | |
111 | ||
112 | - When printing the value, the user would probably rather see the | |
113 | full object, not just the limited portion apparent from the | |
114 | compile-time type. | |
115 | ||
116 | - If `type' has virtual base classes, then even printing `type' | |
117 | alone may require reaching outside the `type' portion of the | |
118 | object to wherever the virtual base class has been stored. | |
119 | ||
120 | When we store the entire object, `enclosing_type' is the run-time | |
121 | type -- the complete object -- and `embedded_offset' is the | |
122 | offset of `type' within that larger type, in bytes. The | |
123 | value_contents() macro takes `embedded_offset' into account, so | |
124 | most GDB code continues to see the `type' portion of the value, | |
125 | just as the inferior would. | |
126 | ||
127 | If `type' is a pointer to an object, then `enclosing_type' is a | |
128 | pointer to the object's run-time type, and `pointed_to_offset' is | |
129 | the offset in bytes from the full object to the pointed-to object | |
130 | -- that is, the value `embedded_offset' would have if we followed | |
131 | the pointer and fetched the complete object. (I don't really see | |
132 | the point. Why not just determine the run-time type when you | |
133 | indirect, and avoid the special case? The contents don't matter | |
134 | until you indirect anyway.) | |
135 | ||
136 | If we're not doing anything fancy, `enclosing_type' is equal to | |
137 | `type', and `embedded_offset' is zero, so everything works | |
138 | normally. */ | |
139 | struct type *enclosing_type; | |
140 | int embedded_offset; | |
141 | int pointed_to_offset; | |
142 | ||
143 | /* Values are stored in a chain, so that they can be deleted easily | |
144 | over calls to the inferior. Values assigned to internal | |
a08702d6 TJB |
145 | variables, put into the value history or exposed to Python are |
146 | taken off this list. */ | |
91294c83 AC |
147 | struct value *next; |
148 | ||
149 | /* Register number if the value is from a register. */ | |
150 | short regnum; | |
151 | ||
152 | /* If zero, contents of this value are in the contents field. If | |
9214ee5f DJ |
153 | nonzero, contents are in inferior. If the lval field is lval_memory, |
154 | the contents are in inferior memory at location.address plus offset. | |
155 | The lval field may also be lval_register. | |
91294c83 AC |
156 | |
157 | WARNING: This field is used by the code which handles watchpoints | |
158 | (see breakpoint.c) to decide whether a particular value can be | |
159 | watched by hardware watchpoints. If the lazy flag is set for | |
160 | some member of a value chain, it is assumed that this member of | |
161 | the chain doesn't need to be watched as part of watching the | |
162 | value itself. This is how GDB avoids watching the entire struct | |
163 | or array when the user wants to watch a single struct member or | |
164 | array element. If you ever change the way lazy flag is set and | |
165 | reset, be sure to consider this use as well! */ | |
166 | char lazy; | |
167 | ||
168 | /* If nonzero, this is the value of a variable which does not | |
169 | actually exist in the program. */ | |
170 | char optimized_out; | |
171 | ||
42be36b3 CT |
172 | /* If value is a variable, is it initialized or not. */ |
173 | int initialized; | |
174 | ||
3e3d7139 JG |
175 | /* Actual contents of the value. Target byte-order. NULL or not |
176 | valid if lazy is nonzero. */ | |
177 | gdb_byte *contents; | |
91294c83 AC |
178 | }; |
179 | ||
c906108c SS |
180 | /* Prototypes for local functions. */ |
181 | ||
a14ed312 | 182 | static void show_values (char *, int); |
c906108c | 183 | |
a14ed312 | 184 | static void show_convenience (char *, int); |
c906108c | 185 | |
c906108c SS |
186 | |
187 | /* The value-history records all the values printed | |
188 | by print commands during this session. Each chunk | |
189 | records 60 consecutive values. The first chunk on | |
190 | the chain records the most recent values. | |
191 | The total number of values is in value_history_count. */ | |
192 | ||
193 | #define VALUE_HISTORY_CHUNK 60 | |
194 | ||
195 | struct value_history_chunk | |
c5aa993b JM |
196 | { |
197 | struct value_history_chunk *next; | |
f23631e4 | 198 | struct value *values[VALUE_HISTORY_CHUNK]; |
c5aa993b | 199 | }; |
c906108c SS |
200 | |
201 | /* Chain of chunks now in use. */ | |
202 | ||
203 | static struct value_history_chunk *value_history_chain; | |
204 | ||
205 | static int value_history_count; /* Abs number of last entry stored */ | |
206 | \f | |
207 | /* List of all value objects currently allocated | |
208 | (except for those released by calls to release_value) | |
209 | This is so they can be freed after each command. */ | |
210 | ||
f23631e4 | 211 | static struct value *all_values; |
c906108c | 212 | |
3e3d7139 JG |
213 | /* Allocate a lazy value for type TYPE. Its actual content is |
214 | "lazily" allocated too: the content field of the return value is | |
215 | NULL; it will be allocated when it is fetched from the target. */ | |
c906108c | 216 | |
f23631e4 | 217 | struct value * |
3e3d7139 | 218 | allocate_value_lazy (struct type *type) |
c906108c | 219 | { |
f23631e4 | 220 | struct value *val; |
c906108c SS |
221 | struct type *atype = check_typedef (type); |
222 | ||
3e3d7139 JG |
223 | val = (struct value *) xzalloc (sizeof (struct value)); |
224 | val->contents = NULL; | |
df407dfe | 225 | val->next = all_values; |
c906108c | 226 | all_values = val; |
df407dfe | 227 | val->type = type; |
4754a64e | 228 | val->enclosing_type = type; |
c906108c SS |
229 | VALUE_LVAL (val) = not_lval; |
230 | VALUE_ADDRESS (val) = 0; | |
1df6926e | 231 | VALUE_FRAME_ID (val) = null_frame_id; |
df407dfe AC |
232 | val->offset = 0; |
233 | val->bitpos = 0; | |
234 | val->bitsize = 0; | |
9ee8fc9d | 235 | VALUE_REGNUM (val) = -1; |
3e3d7139 | 236 | val->lazy = 1; |
feb13ab0 | 237 | val->optimized_out = 0; |
13c3b5f5 | 238 | val->embedded_offset = 0; |
b44d461b | 239 | val->pointed_to_offset = 0; |
c906108c | 240 | val->modifiable = 1; |
42be36b3 | 241 | val->initialized = 1; /* Default to initialized. */ |
c906108c SS |
242 | return val; |
243 | } | |
244 | ||
3e3d7139 JG |
245 | /* Allocate the contents of VAL if it has not been allocated yet. */ |
246 | ||
247 | void | |
248 | allocate_value_contents (struct value *val) | |
249 | { | |
250 | if (!val->contents) | |
251 | val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type)); | |
252 | } | |
253 | ||
254 | /* Allocate a value and its contents for type TYPE. */ | |
255 | ||
256 | struct value * | |
257 | allocate_value (struct type *type) | |
258 | { | |
259 | struct value *val = allocate_value_lazy (type); | |
260 | allocate_value_contents (val); | |
261 | val->lazy = 0; | |
262 | return val; | |
263 | } | |
264 | ||
c906108c | 265 | /* Allocate a value that has the correct length |
938f5214 | 266 | for COUNT repetitions of type TYPE. */ |
c906108c | 267 | |
f23631e4 | 268 | struct value * |
fba45db2 | 269 | allocate_repeat_value (struct type *type, int count) |
c906108c | 270 | { |
c5aa993b | 271 | int low_bound = current_language->string_lower_bound; /* ??? */ |
c906108c SS |
272 | /* FIXME-type-allocation: need a way to free this type when we are |
273 | done with it. */ | |
274 | struct type *range_type | |
6d84d3d8 | 275 | = create_range_type ((struct type *) NULL, builtin_type_int32, |
c5aa993b | 276 | low_bound, count + low_bound - 1); |
c906108c SS |
277 | /* FIXME-type-allocation: need a way to free this type when we are |
278 | done with it. */ | |
279 | return allocate_value (create_array_type ((struct type *) NULL, | |
280 | type, range_type)); | |
281 | } | |
282 | ||
a08702d6 TJB |
283 | /* Needed if another module needs to maintain its on list of values. */ |
284 | void | |
285 | value_prepend_to_list (struct value **head, struct value *val) | |
286 | { | |
287 | val->next = *head; | |
288 | *head = val; | |
289 | } | |
290 | ||
291 | /* Needed if another module needs to maintain its on list of values. */ | |
292 | void | |
293 | value_remove_from_list (struct value **head, struct value *val) | |
294 | { | |
295 | struct value *prev; | |
296 | ||
297 | if (*head == val) | |
298 | *head = (*head)->next; | |
299 | else | |
300 | for (prev = *head; prev->next; prev = prev->next) | |
301 | if (prev->next == val) | |
302 | { | |
303 | prev->next = val->next; | |
304 | break; | |
305 | } | |
306 | } | |
307 | ||
5f5233d4 PA |
308 | struct value * |
309 | allocate_computed_value (struct type *type, | |
310 | struct lval_funcs *funcs, | |
311 | void *closure) | |
312 | { | |
313 | struct value *v = allocate_value (type); | |
314 | VALUE_LVAL (v) = lval_computed; | |
315 | v->location.computed.funcs = funcs; | |
316 | v->location.computed.closure = closure; | |
317 | set_value_lazy (v, 1); | |
318 | ||
319 | return v; | |
320 | } | |
321 | ||
df407dfe AC |
322 | /* Accessor methods. */ |
323 | ||
17cf0ecd AC |
324 | struct value * |
325 | value_next (struct value *value) | |
326 | { | |
327 | return value->next; | |
328 | } | |
329 | ||
df407dfe AC |
330 | struct type * |
331 | value_type (struct value *value) | |
332 | { | |
333 | return value->type; | |
334 | } | |
04624583 AC |
335 | void |
336 | deprecated_set_value_type (struct value *value, struct type *type) | |
337 | { | |
338 | value->type = type; | |
339 | } | |
df407dfe AC |
340 | |
341 | int | |
342 | value_offset (struct value *value) | |
343 | { | |
344 | return value->offset; | |
345 | } | |
f5cf64a7 AC |
346 | void |
347 | set_value_offset (struct value *value, int offset) | |
348 | { | |
349 | value->offset = offset; | |
350 | } | |
df407dfe AC |
351 | |
352 | int | |
353 | value_bitpos (struct value *value) | |
354 | { | |
355 | return value->bitpos; | |
356 | } | |
9bbda503 AC |
357 | void |
358 | set_value_bitpos (struct value *value, int bit) | |
359 | { | |
360 | value->bitpos = bit; | |
361 | } | |
df407dfe AC |
362 | |
363 | int | |
364 | value_bitsize (struct value *value) | |
365 | { | |
366 | return value->bitsize; | |
367 | } | |
9bbda503 AC |
368 | void |
369 | set_value_bitsize (struct value *value, int bit) | |
370 | { | |
371 | value->bitsize = bit; | |
372 | } | |
df407dfe | 373 | |
fc1a4b47 | 374 | gdb_byte * |
990a07ab AC |
375 | value_contents_raw (struct value *value) |
376 | { | |
3e3d7139 JG |
377 | allocate_value_contents (value); |
378 | return value->contents + value->embedded_offset; | |
990a07ab AC |
379 | } |
380 | ||
fc1a4b47 | 381 | gdb_byte * |
990a07ab AC |
382 | value_contents_all_raw (struct value *value) |
383 | { | |
3e3d7139 JG |
384 | allocate_value_contents (value); |
385 | return value->contents; | |
990a07ab AC |
386 | } |
387 | ||
4754a64e AC |
388 | struct type * |
389 | value_enclosing_type (struct value *value) | |
390 | { | |
391 | return value->enclosing_type; | |
392 | } | |
393 | ||
fc1a4b47 | 394 | const gdb_byte * |
46615f07 AC |
395 | value_contents_all (struct value *value) |
396 | { | |
397 | if (value->lazy) | |
398 | value_fetch_lazy (value); | |
3e3d7139 | 399 | return value->contents; |
46615f07 AC |
400 | } |
401 | ||
d69fe07e AC |
402 | int |
403 | value_lazy (struct value *value) | |
404 | { | |
405 | return value->lazy; | |
406 | } | |
407 | ||
dfa52d88 AC |
408 | void |
409 | set_value_lazy (struct value *value, int val) | |
410 | { | |
411 | value->lazy = val; | |
412 | } | |
413 | ||
fc1a4b47 | 414 | const gdb_byte * |
0fd88904 AC |
415 | value_contents (struct value *value) |
416 | { | |
417 | return value_contents_writeable (value); | |
418 | } | |
419 | ||
fc1a4b47 | 420 | gdb_byte * |
0fd88904 AC |
421 | value_contents_writeable (struct value *value) |
422 | { | |
423 | if (value->lazy) | |
424 | value_fetch_lazy (value); | |
fc0c53a0 | 425 | return value_contents_raw (value); |
0fd88904 AC |
426 | } |
427 | ||
a6c442d8 MK |
428 | /* Return non-zero if VAL1 and VAL2 have the same contents. Note that |
429 | this function is different from value_equal; in C the operator == | |
430 | can return 0 even if the two values being compared are equal. */ | |
431 | ||
432 | int | |
433 | value_contents_equal (struct value *val1, struct value *val2) | |
434 | { | |
435 | struct type *type1; | |
436 | struct type *type2; | |
437 | int len; | |
438 | ||
439 | type1 = check_typedef (value_type (val1)); | |
440 | type2 = check_typedef (value_type (val2)); | |
441 | len = TYPE_LENGTH (type1); | |
442 | if (len != TYPE_LENGTH (type2)) | |
443 | return 0; | |
444 | ||
445 | return (memcmp (value_contents (val1), value_contents (val2), len) == 0); | |
446 | } | |
447 | ||
feb13ab0 AC |
448 | int |
449 | value_optimized_out (struct value *value) | |
450 | { | |
451 | return value->optimized_out; | |
452 | } | |
453 | ||
454 | void | |
455 | set_value_optimized_out (struct value *value, int val) | |
456 | { | |
457 | value->optimized_out = val; | |
458 | } | |
13c3b5f5 AC |
459 | |
460 | int | |
461 | value_embedded_offset (struct value *value) | |
462 | { | |
463 | return value->embedded_offset; | |
464 | } | |
465 | ||
466 | void | |
467 | set_value_embedded_offset (struct value *value, int val) | |
468 | { | |
469 | value->embedded_offset = val; | |
470 | } | |
b44d461b AC |
471 | |
472 | int | |
473 | value_pointed_to_offset (struct value *value) | |
474 | { | |
475 | return value->pointed_to_offset; | |
476 | } | |
477 | ||
478 | void | |
479 | set_value_pointed_to_offset (struct value *value, int val) | |
480 | { | |
481 | value->pointed_to_offset = val; | |
482 | } | |
13bb5560 | 483 | |
5f5233d4 PA |
484 | struct lval_funcs * |
485 | value_computed_funcs (struct value *v) | |
486 | { | |
487 | gdb_assert (VALUE_LVAL (v) == lval_computed); | |
488 | ||
489 | return v->location.computed.funcs; | |
490 | } | |
491 | ||
492 | void * | |
493 | value_computed_closure (struct value *v) | |
494 | { | |
495 | gdb_assert (VALUE_LVAL (v) == lval_computed); | |
496 | ||
497 | return v->location.computed.closure; | |
498 | } | |
499 | ||
13bb5560 AC |
500 | enum lval_type * |
501 | deprecated_value_lval_hack (struct value *value) | |
502 | { | |
503 | return &value->lval; | |
504 | } | |
505 | ||
506 | CORE_ADDR * | |
507 | deprecated_value_address_hack (struct value *value) | |
508 | { | |
509 | return &value->location.address; | |
510 | } | |
511 | ||
512 | struct internalvar ** | |
513 | deprecated_value_internalvar_hack (struct value *value) | |
514 | { | |
515 | return &value->location.internalvar; | |
516 | } | |
517 | ||
518 | struct frame_id * | |
519 | deprecated_value_frame_id_hack (struct value *value) | |
520 | { | |
521 | return &value->frame_id; | |
522 | } | |
523 | ||
524 | short * | |
525 | deprecated_value_regnum_hack (struct value *value) | |
526 | { | |
527 | return &value->regnum; | |
528 | } | |
88e3b34b AC |
529 | |
530 | int | |
531 | deprecated_value_modifiable (struct value *value) | |
532 | { | |
533 | return value->modifiable; | |
534 | } | |
535 | void | |
536 | deprecated_set_value_modifiable (struct value *value, int modifiable) | |
537 | { | |
538 | value->modifiable = modifiable; | |
539 | } | |
990a07ab | 540 | \f |
c906108c SS |
541 | /* Return a mark in the value chain. All values allocated after the |
542 | mark is obtained (except for those released) are subject to being freed | |
543 | if a subsequent value_free_to_mark is passed the mark. */ | |
f23631e4 | 544 | struct value * |
fba45db2 | 545 | value_mark (void) |
c906108c SS |
546 | { |
547 | return all_values; | |
548 | } | |
549 | ||
3e3d7139 JG |
550 | void |
551 | value_free (struct value *val) | |
552 | { | |
553 | if (val) | |
5f5233d4 PA |
554 | { |
555 | if (VALUE_LVAL (val) == lval_computed) | |
556 | { | |
557 | struct lval_funcs *funcs = val->location.computed.funcs; | |
558 | ||
559 | if (funcs->free_closure) | |
560 | funcs->free_closure (val); | |
561 | } | |
562 | ||
563 | xfree (val->contents); | |
564 | } | |
3e3d7139 JG |
565 | xfree (val); |
566 | } | |
567 | ||
c906108c SS |
568 | /* Free all values allocated since MARK was obtained by value_mark |
569 | (except for those released). */ | |
570 | void | |
f23631e4 | 571 | value_free_to_mark (struct value *mark) |
c906108c | 572 | { |
f23631e4 AC |
573 | struct value *val; |
574 | struct value *next; | |
c906108c SS |
575 | |
576 | for (val = all_values; val && val != mark; val = next) | |
577 | { | |
df407dfe | 578 | next = val->next; |
c906108c SS |
579 | value_free (val); |
580 | } | |
581 | all_values = val; | |
582 | } | |
583 | ||
584 | /* Free all the values that have been allocated (except for those released). | |
585 | Called after each command, successful or not. */ | |
586 | ||
587 | void | |
fba45db2 | 588 | free_all_values (void) |
c906108c | 589 | { |
f23631e4 AC |
590 | struct value *val; |
591 | struct value *next; | |
c906108c SS |
592 | |
593 | for (val = all_values; val; val = next) | |
594 | { | |
df407dfe | 595 | next = val->next; |
c906108c SS |
596 | value_free (val); |
597 | } | |
598 | ||
599 | all_values = 0; | |
600 | } | |
601 | ||
602 | /* Remove VAL from the chain all_values | |
603 | so it will not be freed automatically. */ | |
604 | ||
605 | void | |
f23631e4 | 606 | release_value (struct value *val) |
c906108c | 607 | { |
f23631e4 | 608 | struct value *v; |
c906108c SS |
609 | |
610 | if (all_values == val) | |
611 | { | |
612 | all_values = val->next; | |
613 | return; | |
614 | } | |
615 | ||
616 | for (v = all_values; v; v = v->next) | |
617 | { | |
618 | if (v->next == val) | |
619 | { | |
620 | v->next = val->next; | |
621 | break; | |
622 | } | |
623 | } | |
624 | } | |
625 | ||
626 | /* Release all values up to mark */ | |
f23631e4 AC |
627 | struct value * |
628 | value_release_to_mark (struct value *mark) | |
c906108c | 629 | { |
f23631e4 AC |
630 | struct value *val; |
631 | struct value *next; | |
c906108c | 632 | |
df407dfe AC |
633 | for (val = next = all_values; next; next = next->next) |
634 | if (next->next == mark) | |
c906108c | 635 | { |
df407dfe AC |
636 | all_values = next->next; |
637 | next->next = NULL; | |
c906108c SS |
638 | return val; |
639 | } | |
640 | all_values = 0; | |
641 | return val; | |
642 | } | |
643 | ||
644 | /* Return a copy of the value ARG. | |
645 | It contains the same contents, for same memory address, | |
646 | but it's a different block of storage. */ | |
647 | ||
f23631e4 AC |
648 | struct value * |
649 | value_copy (struct value *arg) | |
c906108c | 650 | { |
4754a64e | 651 | struct type *encl_type = value_enclosing_type (arg); |
3e3d7139 JG |
652 | struct value *val; |
653 | ||
654 | if (value_lazy (arg)) | |
655 | val = allocate_value_lazy (encl_type); | |
656 | else | |
657 | val = allocate_value (encl_type); | |
df407dfe | 658 | val->type = arg->type; |
c906108c | 659 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
6f7c8fc2 | 660 | val->location = arg->location; |
df407dfe AC |
661 | val->offset = arg->offset; |
662 | val->bitpos = arg->bitpos; | |
663 | val->bitsize = arg->bitsize; | |
1df6926e | 664 | VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
9ee8fc9d | 665 | VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
d69fe07e | 666 | val->lazy = arg->lazy; |
feb13ab0 | 667 | val->optimized_out = arg->optimized_out; |
13c3b5f5 | 668 | val->embedded_offset = value_embedded_offset (arg); |
b44d461b | 669 | val->pointed_to_offset = arg->pointed_to_offset; |
c906108c | 670 | val->modifiable = arg->modifiable; |
d69fe07e | 671 | if (!value_lazy (val)) |
c906108c | 672 | { |
990a07ab | 673 | memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
4754a64e | 674 | TYPE_LENGTH (value_enclosing_type (arg))); |
c906108c SS |
675 | |
676 | } | |
5f5233d4 PA |
677 | if (VALUE_LVAL (val) == lval_computed) |
678 | { | |
679 | struct lval_funcs *funcs = val->location.computed.funcs; | |
680 | ||
681 | if (funcs->copy_closure) | |
682 | val->location.computed.closure = funcs->copy_closure (val); | |
683 | } | |
c906108c SS |
684 | return val; |
685 | } | |
74bcbdf3 PA |
686 | |
687 | void | |
688 | set_value_component_location (struct value *component, struct value *whole) | |
689 | { | |
690 | if (VALUE_LVAL (whole) == lval_internalvar) | |
691 | VALUE_LVAL (component) = lval_internalvar_component; | |
692 | else | |
693 | VALUE_LVAL (component) = VALUE_LVAL (whole); | |
5f5233d4 | 694 | |
74bcbdf3 | 695 | component->location = whole->location; |
5f5233d4 PA |
696 | if (VALUE_LVAL (whole) == lval_computed) |
697 | { | |
698 | struct lval_funcs *funcs = whole->location.computed.funcs; | |
699 | ||
700 | if (funcs->copy_closure) | |
701 | component->location.computed.closure = funcs->copy_closure (whole); | |
702 | } | |
74bcbdf3 PA |
703 | } |
704 | ||
c906108c SS |
705 | \f |
706 | /* Access to the value history. */ | |
707 | ||
708 | /* Record a new value in the value history. | |
709 | Returns the absolute history index of the entry. | |
710 | Result of -1 indicates the value was not saved; otherwise it is the | |
711 | value history index of this new item. */ | |
712 | ||
713 | int | |
f23631e4 | 714 | record_latest_value (struct value *val) |
c906108c SS |
715 | { |
716 | int i; | |
717 | ||
718 | /* We don't want this value to have anything to do with the inferior anymore. | |
719 | In particular, "set $1 = 50" should not affect the variable from which | |
720 | the value was taken, and fast watchpoints should be able to assume that | |
721 | a value on the value history never changes. */ | |
d69fe07e | 722 | if (value_lazy (val)) |
c906108c SS |
723 | value_fetch_lazy (val); |
724 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
725 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
726 | but the current contents of that location. c'est la vie... */ | |
727 | val->modifiable = 0; | |
728 | release_value (val); | |
729 | ||
730 | /* Here we treat value_history_count as origin-zero | |
731 | and applying to the value being stored now. */ | |
732 | ||
733 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
734 | if (i == 0) | |
735 | { | |
f23631e4 | 736 | struct value_history_chunk *new |
c5aa993b JM |
737 | = (struct value_history_chunk *) |
738 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
739 | memset (new->values, 0, sizeof new->values); |
740 | new->next = value_history_chain; | |
741 | value_history_chain = new; | |
742 | } | |
743 | ||
744 | value_history_chain->values[i] = val; | |
745 | ||
746 | /* Now we regard value_history_count as origin-one | |
747 | and applying to the value just stored. */ | |
748 | ||
749 | return ++value_history_count; | |
750 | } | |
751 | ||
752 | /* Return a copy of the value in the history with sequence number NUM. */ | |
753 | ||
f23631e4 | 754 | struct value * |
fba45db2 | 755 | access_value_history (int num) |
c906108c | 756 | { |
f23631e4 | 757 | struct value_history_chunk *chunk; |
52f0bd74 AC |
758 | int i; |
759 | int absnum = num; | |
c906108c SS |
760 | |
761 | if (absnum <= 0) | |
762 | absnum += value_history_count; | |
763 | ||
764 | if (absnum <= 0) | |
765 | { | |
766 | if (num == 0) | |
8a3fe4f8 | 767 | error (_("The history is empty.")); |
c906108c | 768 | else if (num == 1) |
8a3fe4f8 | 769 | error (_("There is only one value in the history.")); |
c906108c | 770 | else |
8a3fe4f8 | 771 | error (_("History does not go back to $$%d."), -num); |
c906108c SS |
772 | } |
773 | if (absnum > value_history_count) | |
8a3fe4f8 | 774 | error (_("History has not yet reached $%d."), absnum); |
c906108c SS |
775 | |
776 | absnum--; | |
777 | ||
778 | /* Now absnum is always absolute and origin zero. */ | |
779 | ||
780 | chunk = value_history_chain; | |
781 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
782 | i > 0; i--) | |
783 | chunk = chunk->next; | |
784 | ||
785 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
786 | } | |
787 | ||
c906108c | 788 | static void |
fba45db2 | 789 | show_values (char *num_exp, int from_tty) |
c906108c | 790 | { |
52f0bd74 | 791 | int i; |
f23631e4 | 792 | struct value *val; |
c906108c SS |
793 | static int num = 1; |
794 | ||
795 | if (num_exp) | |
796 | { | |
f132ba9d TJB |
797 | /* "show values +" should print from the stored position. |
798 | "show values <exp>" should print around value number <exp>. */ | |
c906108c | 799 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 800 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
801 | } |
802 | else | |
803 | { | |
f132ba9d | 804 | /* "show values" means print the last 10 values. */ |
c906108c SS |
805 | num = value_history_count - 9; |
806 | } | |
807 | ||
808 | if (num <= 0) | |
809 | num = 1; | |
810 | ||
811 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
812 | { | |
79a45b7d | 813 | struct value_print_options opts; |
c906108c | 814 | val = access_value_history (i); |
a3f17187 | 815 | printf_filtered (("$%d = "), i); |
79a45b7d TT |
816 | get_user_print_options (&opts); |
817 | value_print (val, gdb_stdout, &opts); | |
a3f17187 | 818 | printf_filtered (("\n")); |
c906108c SS |
819 | } |
820 | ||
f132ba9d | 821 | /* The next "show values +" should start after what we just printed. */ |
c906108c SS |
822 | num += 10; |
823 | ||
824 | /* Hitting just return after this command should do the same thing as | |
f132ba9d TJB |
825 | "show values +". If num_exp is null, this is unnecessary, since |
826 | "show values +" is not useful after "show values". */ | |
c906108c SS |
827 | if (from_tty && num_exp) |
828 | { | |
829 | num_exp[0] = '+'; | |
830 | num_exp[1] = '\0'; | |
831 | } | |
832 | } | |
833 | \f | |
834 | /* Internal variables. These are variables within the debugger | |
835 | that hold values assigned by debugger commands. | |
836 | The user refers to them with a '$' prefix | |
837 | that does not appear in the variable names stored internally. */ | |
838 | ||
839 | static struct internalvar *internalvars; | |
840 | ||
53e5f3cf AS |
841 | /* If the variable does not already exist create it and give it the value given. |
842 | If no value is given then the default is zero. */ | |
843 | static void | |
844 | init_if_undefined_command (char* args, int from_tty) | |
845 | { | |
846 | struct internalvar* intvar; | |
847 | ||
848 | /* Parse the expression - this is taken from set_command(). */ | |
849 | struct expression *expr = parse_expression (args); | |
850 | register struct cleanup *old_chain = | |
851 | make_cleanup (free_current_contents, &expr); | |
852 | ||
853 | /* Validate the expression. | |
854 | Was the expression an assignment? | |
855 | Or even an expression at all? */ | |
856 | if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN) | |
857 | error (_("Init-if-undefined requires an assignment expression.")); | |
858 | ||
859 | /* Extract the variable from the parsed expression. | |
860 | In the case of an assign the lvalue will be in elts[1] and elts[2]. */ | |
861 | if (expr->elts[1].opcode != OP_INTERNALVAR) | |
862 | error (_("The first parameter to init-if-undefined should be a GDB variable.")); | |
863 | intvar = expr->elts[2].internalvar; | |
864 | ||
865 | /* Only evaluate the expression if the lvalue is void. | |
866 | This may still fail if the expresssion is invalid. */ | |
867 | if (TYPE_CODE (value_type (intvar->value)) == TYPE_CODE_VOID) | |
868 | evaluate_expression (expr); | |
869 | ||
870 | do_cleanups (old_chain); | |
871 | } | |
872 | ||
873 | ||
c906108c SS |
874 | /* Look up an internal variable with name NAME. NAME should not |
875 | normally include a dollar sign. | |
876 | ||
877 | If the specified internal variable does not exist, | |
c4a3d09a | 878 | the return value is NULL. */ |
c906108c SS |
879 | |
880 | struct internalvar * | |
c4a3d09a | 881 | lookup_only_internalvar (char *name) |
c906108c | 882 | { |
52f0bd74 | 883 | struct internalvar *var; |
c906108c SS |
884 | |
885 | for (var = internalvars; var; var = var->next) | |
5cb316ef | 886 | if (strcmp (var->name, name) == 0) |
c906108c SS |
887 | return var; |
888 | ||
c4a3d09a MF |
889 | return NULL; |
890 | } | |
891 | ||
892 | ||
893 | /* Create an internal variable with name NAME and with a void value. | |
894 | NAME should not normally include a dollar sign. */ | |
895 | ||
896 | struct internalvar * | |
897 | create_internalvar (char *name) | |
898 | { | |
899 | struct internalvar *var; | |
c906108c | 900 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
1754f103 | 901 | var->name = concat (name, (char *)NULL); |
c906108c | 902 | var->value = allocate_value (builtin_type_void); |
0d20ae72 | 903 | var->endian = gdbarch_byte_order (current_gdbarch); |
c906108c SS |
904 | release_value (var->value); |
905 | var->next = internalvars; | |
906 | internalvars = var; | |
907 | return var; | |
908 | } | |
909 | ||
c4a3d09a MF |
910 | |
911 | /* Look up an internal variable with name NAME. NAME should not | |
912 | normally include a dollar sign. | |
913 | ||
914 | If the specified internal variable does not exist, | |
915 | one is created, with a void value. */ | |
916 | ||
917 | struct internalvar * | |
918 | lookup_internalvar (char *name) | |
919 | { | |
920 | struct internalvar *var; | |
921 | ||
922 | var = lookup_only_internalvar (name); | |
923 | if (var) | |
924 | return var; | |
925 | ||
926 | return create_internalvar (name); | |
927 | } | |
928 | ||
f23631e4 | 929 | struct value * |
fba45db2 | 930 | value_of_internalvar (struct internalvar *var) |
c906108c | 931 | { |
f23631e4 | 932 | struct value *val; |
d3c139e9 AS |
933 | int i, j; |
934 | gdb_byte temp; | |
c906108c | 935 | |
c906108c | 936 | val = value_copy (var->value); |
d69fe07e | 937 | if (value_lazy (val)) |
c906108c | 938 | value_fetch_lazy (val); |
5f5233d4 PA |
939 | |
940 | /* If the variable's value is a computed lvalue, we want references | |
941 | to it to produce another computed lvalue, where referencces and | |
942 | assignments actually operate through the computed value's | |
943 | functions. | |
944 | ||
945 | This means that internal variables with computed values behave a | |
946 | little differently from other internal variables: assignments to | |
947 | them don't just replace the previous value altogether. At the | |
948 | moment, this seems like the behavior we want. */ | |
949 | if (var->value->lval == lval_computed) | |
950 | VALUE_LVAL (val) = lval_computed; | |
951 | else | |
952 | { | |
953 | VALUE_LVAL (val) = lval_internalvar; | |
954 | VALUE_INTERNALVAR (val) = var; | |
955 | } | |
d3c139e9 AS |
956 | |
957 | /* Values are always stored in the target's byte order. When connected to a | |
958 | target this will most likely always be correct, so there's normally no | |
959 | need to worry about it. | |
960 | ||
961 | However, internal variables can be set up before the target endian is | |
962 | known and so may become out of date. Fix it up before anybody sees. | |
963 | ||
964 | Internal variables usually hold simple scalar values, and we can | |
965 | correct those. More complex values (e.g. structures and floating | |
966 | point types) are left alone, because they would be too complicated | |
967 | to correct. */ | |
968 | ||
0d20ae72 | 969 | if (var->endian != gdbarch_byte_order (current_gdbarch)) |
d3c139e9 AS |
970 | { |
971 | gdb_byte *array = value_contents_raw (val); | |
972 | struct type *type = check_typedef (value_enclosing_type (val)); | |
973 | switch (TYPE_CODE (type)) | |
974 | { | |
975 | case TYPE_CODE_INT: | |
976 | case TYPE_CODE_PTR: | |
977 | /* Reverse the bytes. */ | |
978 | for (i = 0, j = TYPE_LENGTH (type) - 1; i < j; i++, j--) | |
979 | { | |
980 | temp = array[j]; | |
981 | array[j] = array[i]; | |
982 | array[i] = temp; | |
983 | } | |
984 | break; | |
985 | } | |
986 | } | |
987 | ||
c906108c SS |
988 | return val; |
989 | } | |
990 | ||
991 | void | |
fba45db2 | 992 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
f23631e4 | 993 | int bitsize, struct value *newval) |
c906108c | 994 | { |
fc1a4b47 | 995 | gdb_byte *addr = value_contents_writeable (var->value) + offset; |
c906108c | 996 | |
c906108c SS |
997 | if (bitsize) |
998 | modify_field (addr, value_as_long (newval), | |
999 | bitpos, bitsize); | |
1000 | else | |
0fd88904 | 1001 | memcpy (addr, value_contents (newval), TYPE_LENGTH (value_type (newval))); |
c906108c SS |
1002 | } |
1003 | ||
1004 | void | |
f23631e4 | 1005 | set_internalvar (struct internalvar *var, struct value *val) |
c906108c | 1006 | { |
f23631e4 | 1007 | struct value *newval; |
c906108c | 1008 | |
c906108c SS |
1009 | newval = value_copy (val); |
1010 | newval->modifiable = 1; | |
1011 | ||
1012 | /* Force the value to be fetched from the target now, to avoid problems | |
1013 | later when this internalvar is referenced and the target is gone or | |
1014 | has changed. */ | |
d69fe07e | 1015 | if (value_lazy (newval)) |
c906108c SS |
1016 | value_fetch_lazy (newval); |
1017 | ||
1018 | /* Begin code which must not call error(). If var->value points to | |
1019 | something free'd, an error() obviously leaves a dangling pointer. | |
1020 | But we also get a danling pointer if var->value points to | |
1021 | something in the value chain (i.e., before release_value is | |
1022 | called), because after the error free_all_values will get called before | |
1023 | long. */ | |
170ce852 | 1024 | value_free (var->value); |
c906108c | 1025 | var->value = newval; |
0d20ae72 | 1026 | var->endian = gdbarch_byte_order (current_gdbarch); |
c906108c SS |
1027 | release_value (newval); |
1028 | /* End code which must not call error(). */ | |
1029 | } | |
1030 | ||
1031 | char * | |
fba45db2 | 1032 | internalvar_name (struct internalvar *var) |
c906108c SS |
1033 | { |
1034 | return var->name; | |
1035 | } | |
1036 | ||
ae5a43e0 DJ |
1037 | /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to |
1038 | prevent cycles / duplicates. */ | |
1039 | ||
1040 | static void | |
1041 | preserve_one_value (struct value *value, struct objfile *objfile, | |
1042 | htab_t copied_types) | |
1043 | { | |
1044 | if (TYPE_OBJFILE (value->type) == objfile) | |
1045 | value->type = copy_type_recursive (objfile, value->type, copied_types); | |
1046 | ||
1047 | if (TYPE_OBJFILE (value->enclosing_type) == objfile) | |
1048 | value->enclosing_type = copy_type_recursive (objfile, | |
1049 | value->enclosing_type, | |
1050 | copied_types); | |
1051 | } | |
1052 | ||
1053 | /* Update the internal variables and value history when OBJFILE is | |
1054 | discarded; we must copy the types out of the objfile. New global types | |
1055 | will be created for every convenience variable which currently points to | |
1056 | this objfile's types, and the convenience variables will be adjusted to | |
1057 | use the new global types. */ | |
c906108c SS |
1058 | |
1059 | void | |
ae5a43e0 | 1060 | preserve_values (struct objfile *objfile) |
c906108c | 1061 | { |
ae5a43e0 DJ |
1062 | htab_t copied_types; |
1063 | struct value_history_chunk *cur; | |
52f0bd74 | 1064 | struct internalvar *var; |
a08702d6 | 1065 | struct value *val; |
ae5a43e0 | 1066 | int i; |
c906108c | 1067 | |
ae5a43e0 DJ |
1068 | /* Create the hash table. We allocate on the objfile's obstack, since |
1069 | it is soon to be deleted. */ | |
1070 | copied_types = create_copied_types_hash (objfile); | |
1071 | ||
1072 | for (cur = value_history_chain; cur; cur = cur->next) | |
1073 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
1074 | if (cur->values[i]) | |
1075 | preserve_one_value (cur->values[i], objfile, copied_types); | |
1076 | ||
1077 | for (var = internalvars; var; var = var->next) | |
1078 | preserve_one_value (var->value, objfile, copied_types); | |
1079 | ||
a08702d6 TJB |
1080 | for (val = values_in_python; val; val = val->next) |
1081 | preserve_one_value (val, objfile, copied_types); | |
1082 | ||
ae5a43e0 | 1083 | htab_delete (copied_types); |
c906108c SS |
1084 | } |
1085 | ||
1086 | static void | |
fba45db2 | 1087 | show_convenience (char *ignore, int from_tty) |
c906108c | 1088 | { |
52f0bd74 | 1089 | struct internalvar *var; |
c906108c | 1090 | int varseen = 0; |
79a45b7d | 1091 | struct value_print_options opts; |
c906108c | 1092 | |
79a45b7d | 1093 | get_user_print_options (&opts); |
c906108c SS |
1094 | for (var = internalvars; var; var = var->next) |
1095 | { | |
c906108c SS |
1096 | if (!varseen) |
1097 | { | |
1098 | varseen = 1; | |
1099 | } | |
a3f17187 | 1100 | printf_filtered (("$%s = "), var->name); |
d3c139e9 | 1101 | value_print (value_of_internalvar (var), gdb_stdout, |
79a45b7d | 1102 | &opts); |
a3f17187 | 1103 | printf_filtered (("\n")); |
c906108c SS |
1104 | } |
1105 | if (!varseen) | |
a3f17187 AC |
1106 | printf_unfiltered (_("\ |
1107 | No debugger convenience variables now defined.\n\ | |
c906108c | 1108 | Convenience variables have names starting with \"$\";\n\ |
a3f17187 | 1109 | use \"set\" as in \"set $foo = 5\" to define them.\n")); |
c906108c SS |
1110 | } |
1111 | \f | |
1112 | /* Extract a value as a C number (either long or double). | |
1113 | Knows how to convert fixed values to double, or | |
1114 | floating values to long. | |
1115 | Does not deallocate the value. */ | |
1116 | ||
1117 | LONGEST | |
f23631e4 | 1118 | value_as_long (struct value *val) |
c906108c SS |
1119 | { |
1120 | /* This coerces arrays and functions, which is necessary (e.g. | |
1121 | in disassemble_command). It also dereferences references, which | |
1122 | I suspect is the most logical thing to do. */ | |
994b9211 | 1123 | val = coerce_array (val); |
0fd88904 | 1124 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
1125 | } |
1126 | ||
1127 | DOUBLEST | |
f23631e4 | 1128 | value_as_double (struct value *val) |
c906108c SS |
1129 | { |
1130 | DOUBLEST foo; | |
1131 | int inv; | |
c5aa993b | 1132 | |
0fd88904 | 1133 | foo = unpack_double (value_type (val), value_contents (val), &inv); |
c906108c | 1134 | if (inv) |
8a3fe4f8 | 1135 | error (_("Invalid floating value found in program.")); |
c906108c SS |
1136 | return foo; |
1137 | } | |
4ef30785 | 1138 | |
4478b372 JB |
1139 | /* Extract a value as a C pointer. Does not deallocate the value. |
1140 | Note that val's type may not actually be a pointer; value_as_long | |
1141 | handles all the cases. */ | |
c906108c | 1142 | CORE_ADDR |
f23631e4 | 1143 | value_as_address (struct value *val) |
c906108c SS |
1144 | { |
1145 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
1146 | whether we want this to be true eventually. */ | |
1147 | #if 0 | |
bf6ae464 | 1148 | /* gdbarch_addr_bits_remove is wrong if we are being called for a |
c906108c SS |
1149 | non-address (e.g. argument to "signal", "info break", etc.), or |
1150 | for pointers to char, in which the low bits *are* significant. */ | |
bf6ae464 | 1151 | return gdbarch_addr_bits_remove (current_gdbarch, value_as_long (val)); |
c906108c | 1152 | #else |
f312f057 JB |
1153 | |
1154 | /* There are several targets (IA-64, PowerPC, and others) which | |
1155 | don't represent pointers to functions as simply the address of | |
1156 | the function's entry point. For example, on the IA-64, a | |
1157 | function pointer points to a two-word descriptor, generated by | |
1158 | the linker, which contains the function's entry point, and the | |
1159 | value the IA-64 "global pointer" register should have --- to | |
1160 | support position-independent code. The linker generates | |
1161 | descriptors only for those functions whose addresses are taken. | |
1162 | ||
1163 | On such targets, it's difficult for GDB to convert an arbitrary | |
1164 | function address into a function pointer; it has to either find | |
1165 | an existing descriptor for that function, or call malloc and | |
1166 | build its own. On some targets, it is impossible for GDB to | |
1167 | build a descriptor at all: the descriptor must contain a jump | |
1168 | instruction; data memory cannot be executed; and code memory | |
1169 | cannot be modified. | |
1170 | ||
1171 | Upon entry to this function, if VAL is a value of type `function' | |
1172 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
1173 | VALUE_ADDRESS (val) is the address of the function. This is what | |
1174 | you'll get if you evaluate an expression like `main'. The call | |
1175 | to COERCE_ARRAY below actually does all the usual unary | |
1176 | conversions, which includes converting values of type `function' | |
1177 | to `pointer to function'. This is the challenging conversion | |
1178 | discussed above. Then, `unpack_long' will convert that pointer | |
1179 | back into an address. | |
1180 | ||
1181 | So, suppose the user types `disassemble foo' on an architecture | |
1182 | with a strange function pointer representation, on which GDB | |
1183 | cannot build its own descriptors, and suppose further that `foo' | |
1184 | has no linker-built descriptor. The address->pointer conversion | |
1185 | will signal an error and prevent the command from running, even | |
1186 | though the next step would have been to convert the pointer | |
1187 | directly back into the same address. | |
1188 | ||
1189 | The following shortcut avoids this whole mess. If VAL is a | |
1190 | function, just return its address directly. */ | |
df407dfe AC |
1191 | if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
1192 | || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) | |
f312f057 JB |
1193 | return VALUE_ADDRESS (val); |
1194 | ||
994b9211 | 1195 | val = coerce_array (val); |
fc0c74b1 AC |
1196 | |
1197 | /* Some architectures (e.g. Harvard), map instruction and data | |
1198 | addresses onto a single large unified address space. For | |
1199 | instance: An architecture may consider a large integer in the | |
1200 | range 0x10000000 .. 0x1000ffff to already represent a data | |
1201 | addresses (hence not need a pointer to address conversion) while | |
1202 | a small integer would still need to be converted integer to | |
1203 | pointer to address. Just assume such architectures handle all | |
1204 | integer conversions in a single function. */ | |
1205 | ||
1206 | /* JimB writes: | |
1207 | ||
1208 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
1209 | must admonish GDB hackers to make sure its behavior matches the | |
1210 | compiler's, whenever possible. | |
1211 | ||
1212 | In general, I think GDB should evaluate expressions the same way | |
1213 | the compiler does. When the user copies an expression out of | |
1214 | their source code and hands it to a `print' command, they should | |
1215 | get the same value the compiler would have computed. Any | |
1216 | deviation from this rule can cause major confusion and annoyance, | |
1217 | and needs to be justified carefully. In other words, GDB doesn't | |
1218 | really have the freedom to do these conversions in clever and | |
1219 | useful ways. | |
1220 | ||
1221 | AndrewC pointed out that users aren't complaining about how GDB | |
1222 | casts integers to pointers; they are complaining that they can't | |
1223 | take an address from a disassembly listing and give it to `x/i'. | |
1224 | This is certainly important. | |
1225 | ||
79dd2d24 | 1226 | Adding an architecture method like integer_to_address() certainly |
fc0c74b1 AC |
1227 | makes it possible for GDB to "get it right" in all circumstances |
1228 | --- the target has complete control over how things get done, so | |
1229 | people can Do The Right Thing for their target without breaking | |
1230 | anyone else. The standard doesn't specify how integers get | |
1231 | converted to pointers; usually, the ABI doesn't either, but | |
1232 | ABI-specific code is a more reasonable place to handle it. */ | |
1233 | ||
df407dfe AC |
1234 | if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
1235 | && TYPE_CODE (value_type (val)) != TYPE_CODE_REF | |
79dd2d24 AC |
1236 | && gdbarch_integer_to_address_p (current_gdbarch)) |
1237 | return gdbarch_integer_to_address (current_gdbarch, value_type (val), | |
0fd88904 | 1238 | value_contents (val)); |
fc0c74b1 | 1239 | |
0fd88904 | 1240 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
1241 | #endif |
1242 | } | |
1243 | \f | |
1244 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
1245 | as a long, or as a double, assuming the raw data is described | |
1246 | by type TYPE. Knows how to convert different sizes of values | |
1247 | and can convert between fixed and floating point. We don't assume | |
1248 | any alignment for the raw data. Return value is in host byte order. | |
1249 | ||
1250 | If you want functions and arrays to be coerced to pointers, and | |
1251 | references to be dereferenced, call value_as_long() instead. | |
1252 | ||
1253 | C++: It is assumed that the front-end has taken care of | |
1254 | all matters concerning pointers to members. A pointer | |
1255 | to member which reaches here is considered to be equivalent | |
1256 | to an INT (or some size). After all, it is only an offset. */ | |
1257 | ||
1258 | LONGEST | |
fc1a4b47 | 1259 | unpack_long (struct type *type, const gdb_byte *valaddr) |
c906108c | 1260 | { |
52f0bd74 AC |
1261 | enum type_code code = TYPE_CODE (type); |
1262 | int len = TYPE_LENGTH (type); | |
1263 | int nosign = TYPE_UNSIGNED (type); | |
c906108c | 1264 | |
c906108c SS |
1265 | switch (code) |
1266 | { | |
1267 | case TYPE_CODE_TYPEDEF: | |
1268 | return unpack_long (check_typedef (type), valaddr); | |
1269 | case TYPE_CODE_ENUM: | |
4f2aea11 | 1270 | case TYPE_CODE_FLAGS: |
c906108c SS |
1271 | case TYPE_CODE_BOOL: |
1272 | case TYPE_CODE_INT: | |
1273 | case TYPE_CODE_CHAR: | |
1274 | case TYPE_CODE_RANGE: | |
0d5de010 | 1275 | case TYPE_CODE_MEMBERPTR: |
c906108c SS |
1276 | if (nosign) |
1277 | return extract_unsigned_integer (valaddr, len); | |
1278 | else | |
1279 | return extract_signed_integer (valaddr, len); | |
1280 | ||
1281 | case TYPE_CODE_FLT: | |
96d2f608 | 1282 | return extract_typed_floating (valaddr, type); |
c906108c | 1283 | |
4ef30785 TJB |
1284 | case TYPE_CODE_DECFLOAT: |
1285 | /* libdecnumber has a function to convert from decimal to integer, but | |
1286 | it doesn't work when the decimal number has a fractional part. */ | |
ba759613 | 1287 | return decimal_to_doublest (valaddr, len); |
4ef30785 | 1288 | |
c906108c SS |
1289 | case TYPE_CODE_PTR: |
1290 | case TYPE_CODE_REF: | |
1291 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 1292 | whether we want this to be true eventually. */ |
4478b372 | 1293 | return extract_typed_address (valaddr, type); |
c906108c | 1294 | |
c906108c | 1295 | default: |
8a3fe4f8 | 1296 | error (_("Value can't be converted to integer.")); |
c906108c | 1297 | } |
c5aa993b | 1298 | return 0; /* Placate lint. */ |
c906108c SS |
1299 | } |
1300 | ||
1301 | /* Return a double value from the specified type and address. | |
1302 | INVP points to an int which is set to 0 for valid value, | |
1303 | 1 for invalid value (bad float format). In either case, | |
1304 | the returned double is OK to use. Argument is in target | |
1305 | format, result is in host format. */ | |
1306 | ||
1307 | DOUBLEST | |
fc1a4b47 | 1308 | unpack_double (struct type *type, const gdb_byte *valaddr, int *invp) |
c906108c SS |
1309 | { |
1310 | enum type_code code; | |
1311 | int len; | |
1312 | int nosign; | |
1313 | ||
1314 | *invp = 0; /* Assume valid. */ | |
1315 | CHECK_TYPEDEF (type); | |
1316 | code = TYPE_CODE (type); | |
1317 | len = TYPE_LENGTH (type); | |
1318 | nosign = TYPE_UNSIGNED (type); | |
1319 | if (code == TYPE_CODE_FLT) | |
1320 | { | |
75bc7ddf AC |
1321 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
1322 | floating-point value was valid (using the macro | |
1323 | INVALID_FLOAT). That test/macro have been removed. | |
1324 | ||
1325 | It turns out that only the VAX defined this macro and then | |
1326 | only in a non-portable way. Fixing the portability problem | |
1327 | wouldn't help since the VAX floating-point code is also badly | |
1328 | bit-rotten. The target needs to add definitions for the | |
ea06eb3d | 1329 | methods gdbarch_float_format and gdbarch_double_format - these |
75bc7ddf AC |
1330 | exactly describe the target floating-point format. The |
1331 | problem here is that the corresponding floatformat_vax_f and | |
1332 | floatformat_vax_d values these methods should be set to are | |
1333 | also not defined either. Oops! | |
1334 | ||
1335 | Hopefully someone will add both the missing floatformat | |
ac79b88b DJ |
1336 | definitions and the new cases for floatformat_is_valid (). */ |
1337 | ||
1338 | if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) | |
1339 | { | |
1340 | *invp = 1; | |
1341 | return 0.0; | |
1342 | } | |
1343 | ||
96d2f608 | 1344 | return extract_typed_floating (valaddr, type); |
c906108c | 1345 | } |
4ef30785 | 1346 | else if (code == TYPE_CODE_DECFLOAT) |
ba759613 | 1347 | return decimal_to_doublest (valaddr, len); |
c906108c SS |
1348 | else if (nosign) |
1349 | { | |
1350 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 1351 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
1352 | } |
1353 | else | |
1354 | { | |
1355 | /* Signed -- we are OK with unpack_long. */ | |
1356 | return unpack_long (type, valaddr); | |
1357 | } | |
1358 | } | |
1359 | ||
1360 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
1361 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
1362 | We don't assume any alignment for the raw data. Return value is in | |
1363 | host byte order. | |
1364 | ||
1365 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 1366 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
1367 | |
1368 | C++: It is assumed that the front-end has taken care of | |
1369 | all matters concerning pointers to members. A pointer | |
1370 | to member which reaches here is considered to be equivalent | |
1371 | to an INT (or some size). After all, it is only an offset. */ | |
1372 | ||
1373 | CORE_ADDR | |
fc1a4b47 | 1374 | unpack_pointer (struct type *type, const gdb_byte *valaddr) |
c906108c SS |
1375 | { |
1376 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
1377 | whether we want this to be true eventually. */ | |
1378 | return unpack_long (type, valaddr); | |
1379 | } | |
4478b372 | 1380 | |
c906108c | 1381 | \f |
2c2738a0 DC |
1382 | /* Get the value of the FIELDN'th field (which must be static) of |
1383 | TYPE. Return NULL if the field doesn't exist or has been | |
1384 | optimized out. */ | |
c906108c | 1385 | |
f23631e4 | 1386 | struct value * |
fba45db2 | 1387 | value_static_field (struct type *type, int fieldno) |
c906108c | 1388 | { |
948e66d9 DJ |
1389 | struct value *retval; |
1390 | ||
d6a843b5 | 1391 | if (TYPE_FIELD_LOC_KIND (type, fieldno) == FIELD_LOC_KIND_PHYSADDR) |
c906108c | 1392 | { |
948e66d9 | 1393 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 1394 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
c906108c SS |
1395 | } |
1396 | else | |
1397 | { | |
1398 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
2570f2b7 | 1399 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); |
948e66d9 | 1400 | if (sym == NULL) |
c906108c SS |
1401 | { |
1402 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
1403 | as non-debuggable symbols */ |
1404 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
1405 | if (!msym) |
1406 | return NULL; | |
1407 | else | |
c5aa993b | 1408 | { |
948e66d9 | 1409 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 1410 | SYMBOL_VALUE_ADDRESS (msym)); |
c906108c SS |
1411 | } |
1412 | } | |
1413 | else | |
1414 | { | |
948e66d9 DJ |
1415 | /* SYM should never have a SYMBOL_CLASS which will require |
1416 | read_var_value to use the FRAME parameter. */ | |
1417 | if (symbol_read_needs_frame (sym)) | |
8a3fe4f8 AC |
1418 | warning (_("static field's value depends on the current " |
1419 | "frame - bad debug info?")); | |
948e66d9 | 1420 | retval = read_var_value (sym, NULL); |
2b127877 | 1421 | } |
948e66d9 DJ |
1422 | if (retval && VALUE_LVAL (retval) == lval_memory) |
1423 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), | |
1424 | VALUE_ADDRESS (retval)); | |
c906108c | 1425 | } |
948e66d9 | 1426 | return retval; |
c906108c SS |
1427 | } |
1428 | ||
2b127877 DB |
1429 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
1430 | You have to be careful here, since the size of the data area for the value | |
1431 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
1432 | than the old enclosing type, you have to allocate more space for the data. | |
1433 | The return value is a pointer to the new version of this value structure. */ | |
1434 | ||
f23631e4 AC |
1435 | struct value * |
1436 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) | |
2b127877 | 1437 | { |
3e3d7139 JG |
1438 | if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val))) |
1439 | val->contents = | |
1440 | (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type)); | |
1441 | ||
1442 | val->enclosing_type = new_encl_type; | |
1443 | return val; | |
2b127877 DB |
1444 | } |
1445 | ||
c906108c SS |
1446 | /* Given a value ARG1 (offset by OFFSET bytes) |
1447 | of a struct or union type ARG_TYPE, | |
1448 | extract and return the value of one of its (non-static) fields. | |
1449 | FIELDNO says which field. */ | |
1450 | ||
f23631e4 AC |
1451 | struct value * |
1452 | value_primitive_field (struct value *arg1, int offset, | |
aa1ee363 | 1453 | int fieldno, struct type *arg_type) |
c906108c | 1454 | { |
f23631e4 | 1455 | struct value *v; |
52f0bd74 | 1456 | struct type *type; |
c906108c SS |
1457 | |
1458 | CHECK_TYPEDEF (arg_type); | |
1459 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
1460 | ||
1461 | /* Handle packed fields */ | |
1462 | ||
1463 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
1464 | { | |
1465 | v = value_from_longest (type, | |
1466 | unpack_field_as_long (arg_type, | |
0fd88904 | 1467 | value_contents (arg1) |
c5aa993b | 1468 | + offset, |
c906108c | 1469 | fieldno)); |
df407dfe AC |
1470 | v->bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; |
1471 | v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
1472 | v->offset = value_offset (arg1) + offset | |
2e70b7b9 | 1473 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
c906108c SS |
1474 | } |
1475 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
1476 | { | |
1477 | /* This field is actually a base subobject, so preserve the | |
1478 | entire object's contents for later references to virtual | |
1479 | bases, etc. */ | |
a4e2ee12 DJ |
1480 | |
1481 | /* Lazy register values with offsets are not supported. */ | |
1482 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) | |
1483 | value_fetch_lazy (arg1); | |
1484 | ||
1485 | if (value_lazy (arg1)) | |
3e3d7139 | 1486 | v = allocate_value_lazy (value_enclosing_type (arg1)); |
c906108c | 1487 | else |
3e3d7139 JG |
1488 | { |
1489 | v = allocate_value (value_enclosing_type (arg1)); | |
1490 | memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1), | |
1491 | TYPE_LENGTH (value_enclosing_type (arg1))); | |
1492 | } | |
1493 | v->type = type; | |
df407dfe | 1494 | v->offset = value_offset (arg1); |
13c3b5f5 AC |
1495 | v->embedded_offset = (offset + value_embedded_offset (arg1) |
1496 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8); | |
c906108c SS |
1497 | } |
1498 | else | |
1499 | { | |
1500 | /* Plain old data member */ | |
1501 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
a4e2ee12 DJ |
1502 | |
1503 | /* Lazy register values with offsets are not supported. */ | |
1504 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) | |
1505 | value_fetch_lazy (arg1); | |
1506 | ||
1507 | if (value_lazy (arg1)) | |
3e3d7139 | 1508 | v = allocate_value_lazy (type); |
c906108c | 1509 | else |
3e3d7139 JG |
1510 | { |
1511 | v = allocate_value (type); | |
1512 | memcpy (value_contents_raw (v), | |
1513 | value_contents_raw (arg1) + offset, | |
1514 | TYPE_LENGTH (type)); | |
1515 | } | |
df407dfe | 1516 | v->offset = (value_offset (arg1) + offset |
13c3b5f5 | 1517 | + value_embedded_offset (arg1)); |
c906108c | 1518 | } |
74bcbdf3 | 1519 | set_value_component_location (v, arg1); |
9ee8fc9d | 1520 | VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
0c16dd26 | 1521 | VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
c906108c SS |
1522 | return v; |
1523 | } | |
1524 | ||
1525 | /* Given a value ARG1 of a struct or union type, | |
1526 | extract and return the value of one of its (non-static) fields. | |
1527 | FIELDNO says which field. */ | |
1528 | ||
f23631e4 | 1529 | struct value * |
aa1ee363 | 1530 | value_field (struct value *arg1, int fieldno) |
c906108c | 1531 | { |
df407dfe | 1532 | return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
c906108c SS |
1533 | } |
1534 | ||
1535 | /* Return a non-virtual function as a value. | |
1536 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
1537 | J is an index into F which provides the desired method. |
1538 | ||
1539 | We only use the symbol for its address, so be happy with either a | |
1540 | full symbol or a minimal symbol. | |
1541 | */ | |
c906108c | 1542 | |
f23631e4 AC |
1543 | struct value * |
1544 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, | |
fba45db2 | 1545 | int offset) |
c906108c | 1546 | { |
f23631e4 | 1547 | struct value *v; |
52f0bd74 | 1548 | struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
0478d61c | 1549 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 1550 | struct symbol *sym; |
0478d61c | 1551 | struct minimal_symbol *msym; |
c906108c | 1552 | |
2570f2b7 | 1553 | sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0); |
5ae326fa | 1554 | if (sym != NULL) |
0478d61c | 1555 | { |
5ae326fa AC |
1556 | msym = NULL; |
1557 | } | |
1558 | else | |
1559 | { | |
1560 | gdb_assert (sym == NULL); | |
0478d61c | 1561 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
1562 | if (msym == NULL) |
1563 | return NULL; | |
0478d61c FF |
1564 | } |
1565 | ||
c906108c | 1566 | v = allocate_value (ftype); |
0478d61c FF |
1567 | if (sym) |
1568 | { | |
1569 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
1570 | } | |
1571 | else | |
1572 | { | |
bccdca4a UW |
1573 | /* The minimal symbol might point to a function descriptor; |
1574 | resolve it to the actual code address instead. */ | |
1575 | struct objfile *objfile = msymbol_objfile (msym); | |
1576 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
1577 | ||
1578 | VALUE_ADDRESS (v) | |
1579 | = gdbarch_convert_from_func_ptr_addr | |
1580 | (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target); | |
0478d61c | 1581 | } |
c906108c SS |
1582 | |
1583 | if (arg1p) | |
c5aa993b | 1584 | { |
df407dfe | 1585 | if (type != value_type (*arg1p)) |
c5aa993b JM |
1586 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
1587 | value_addr (*arg1p))); | |
1588 | ||
070ad9f0 | 1589 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1590 | VALUE_OFFSET (*arg1p) += offset; |
1591 | */ | |
c906108c SS |
1592 | } |
1593 | ||
1594 | return v; | |
1595 | } | |
1596 | ||
c906108c SS |
1597 | \f |
1598 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1599 | VALADDR. | |
1600 | ||
1601 | Extracting bits depends on endianness of the machine. Compute the | |
1602 | number of least significant bits to discard. For big endian machines, | |
1603 | we compute the total number of bits in the anonymous object, subtract | |
1604 | off the bit count from the MSB of the object to the MSB of the | |
1605 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1606 | count. For little endian machines, the discard count is simply the | |
1607 | number of bits from the LSB of the anonymous object to the LSB of the | |
1608 | bitfield. | |
1609 | ||
1610 | If the field is signed, we also do sign extension. */ | |
1611 | ||
1612 | LONGEST | |
fc1a4b47 | 1613 | unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno) |
c906108c SS |
1614 | { |
1615 | ULONGEST val; | |
1616 | ULONGEST valmask; | |
1617 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1618 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1619 | int lsbcount; | |
1620 | struct type *field_type; | |
1621 | ||
1622 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1623 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1624 | CHECK_TYPEDEF (field_type); | |
1625 | ||
1626 | /* Extract bits. See comment above. */ | |
1627 | ||
32c9a795 | 1628 | if (gdbarch_bits_big_endian (current_gdbarch)) |
c906108c SS |
1629 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); |
1630 | else | |
1631 | lsbcount = (bitpos % 8); | |
1632 | val >>= lsbcount; | |
1633 | ||
1634 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1635 | If the field is signed, and is negative, then sign extend. */ | |
1636 | ||
1637 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1638 | { | |
1639 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1640 | val &= valmask; | |
1641 | if (!TYPE_UNSIGNED (field_type)) | |
1642 | { | |
1643 | if (val & (valmask ^ (valmask >> 1))) | |
1644 | { | |
1645 | val |= ~valmask; | |
1646 | } | |
1647 | } | |
1648 | } | |
1649 | return (val); | |
1650 | } | |
1651 | ||
1652 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1653 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1654 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
f4e88c8e PH |
1655 | indicate which bits (in target bit order) comprise the bitfield. |
1656 | Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and | |
1657 | 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ | |
c906108c SS |
1658 | |
1659 | void | |
fc1a4b47 | 1660 | modify_field (gdb_byte *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c | 1661 | { |
f4e88c8e PH |
1662 | ULONGEST oword; |
1663 | ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); | |
c906108c SS |
1664 | |
1665 | /* If a negative fieldval fits in the field in question, chop | |
1666 | off the sign extension bits. */ | |
f4e88c8e PH |
1667 | if ((~fieldval & ~(mask >> 1)) == 0) |
1668 | fieldval &= mask; | |
c906108c SS |
1669 | |
1670 | /* Warn if value is too big to fit in the field in question. */ | |
f4e88c8e | 1671 | if (0 != (fieldval & ~mask)) |
c906108c SS |
1672 | { |
1673 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1674 | we don't have a sprintf_longest. */ |
8a3fe4f8 | 1675 | warning (_("Value does not fit in %d bits."), bitsize); |
c906108c SS |
1676 | |
1677 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
f4e88c8e | 1678 | fieldval &= mask; |
c906108c SS |
1679 | } |
1680 | ||
f4e88c8e | 1681 | oword = extract_unsigned_integer (addr, sizeof oword); |
c906108c SS |
1682 | |
1683 | /* Shifting for bit field depends on endianness of the target machine. */ | |
32c9a795 | 1684 | if (gdbarch_bits_big_endian (current_gdbarch)) |
c906108c SS |
1685 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; |
1686 | ||
f4e88c8e | 1687 | oword &= ~(mask << bitpos); |
c906108c SS |
1688 | oword |= fieldval << bitpos; |
1689 | ||
f4e88c8e | 1690 | store_unsigned_integer (addr, sizeof oword, oword); |
c906108c SS |
1691 | } |
1692 | \f | |
14d06750 | 1693 | /* Pack NUM into BUF using a target format of TYPE. */ |
c906108c | 1694 | |
14d06750 DJ |
1695 | void |
1696 | pack_long (gdb_byte *buf, struct type *type, LONGEST num) | |
c906108c | 1697 | { |
52f0bd74 | 1698 | int len; |
14d06750 DJ |
1699 | |
1700 | type = check_typedef (type); | |
c906108c SS |
1701 | len = TYPE_LENGTH (type); |
1702 | ||
14d06750 | 1703 | switch (TYPE_CODE (type)) |
c906108c | 1704 | { |
c906108c SS |
1705 | case TYPE_CODE_INT: |
1706 | case TYPE_CODE_CHAR: | |
1707 | case TYPE_CODE_ENUM: | |
4f2aea11 | 1708 | case TYPE_CODE_FLAGS: |
c906108c SS |
1709 | case TYPE_CODE_BOOL: |
1710 | case TYPE_CODE_RANGE: | |
0d5de010 | 1711 | case TYPE_CODE_MEMBERPTR: |
14d06750 | 1712 | store_signed_integer (buf, len, num); |
c906108c | 1713 | break; |
c5aa993b | 1714 | |
c906108c SS |
1715 | case TYPE_CODE_REF: |
1716 | case TYPE_CODE_PTR: | |
14d06750 | 1717 | store_typed_address (buf, type, (CORE_ADDR) num); |
c906108c | 1718 | break; |
c5aa993b | 1719 | |
c906108c | 1720 | default: |
14d06750 DJ |
1721 | error (_("Unexpected type (%d) encountered for integer constant."), |
1722 | TYPE_CODE (type)); | |
c906108c | 1723 | } |
14d06750 DJ |
1724 | } |
1725 | ||
1726 | ||
1727 | /* Convert C numbers into newly allocated values. */ | |
1728 | ||
1729 | struct value * | |
1730 | value_from_longest (struct type *type, LONGEST num) | |
1731 | { | |
1732 | struct value *val = allocate_value (type); | |
1733 | ||
1734 | pack_long (value_contents_raw (val), type, num); | |
1735 | ||
c906108c SS |
1736 | return val; |
1737 | } | |
1738 | ||
4478b372 JB |
1739 | |
1740 | /* Create a value representing a pointer of type TYPE to the address | |
1741 | ADDR. */ | |
f23631e4 | 1742 | struct value * |
4478b372 JB |
1743 | value_from_pointer (struct type *type, CORE_ADDR addr) |
1744 | { | |
f23631e4 | 1745 | struct value *val = allocate_value (type); |
990a07ab | 1746 | store_typed_address (value_contents_raw (val), type, addr); |
4478b372 JB |
1747 | return val; |
1748 | } | |
1749 | ||
1750 | ||
0f71a2f6 | 1751 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1752 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1753 | This is analogous to value_from_longest, which also does not |
1754 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1755 | ||
f23631e4 | 1756 | struct value * |
fba45db2 | 1757 | value_from_string (char *ptr) |
0f71a2f6 | 1758 | { |
f23631e4 | 1759 | struct value *val; |
c5aa993b | 1760 | int len = strlen (ptr); |
0f71a2f6 | 1761 | int lowbound = current_language->string_lower_bound; |
f290d38e AC |
1762 | struct type *string_char_type; |
1763 | struct type *rangetype; | |
1764 | struct type *stringtype; | |
1765 | ||
1766 | rangetype = create_range_type ((struct type *) NULL, | |
6d84d3d8 | 1767 | builtin_type_int32, |
f290d38e AC |
1768 | lowbound, len + lowbound - 1); |
1769 | string_char_type = language_string_char_type (current_language, | |
1770 | current_gdbarch); | |
1771 | stringtype = create_array_type ((struct type *) NULL, | |
1772 | string_char_type, | |
1773 | rangetype); | |
0f71a2f6 | 1774 | val = allocate_value (stringtype); |
990a07ab | 1775 | memcpy (value_contents_raw (val), ptr, len); |
0f71a2f6 JM |
1776 | return val; |
1777 | } | |
1778 | ||
8acb6b92 TT |
1779 | /* Create a value of type TYPE whose contents come from VALADDR, if it |
1780 | is non-null, and whose memory address (in the inferior) is | |
1781 | ADDRESS. */ | |
1782 | ||
1783 | struct value * | |
1784 | value_from_contents_and_address (struct type *type, | |
1785 | const gdb_byte *valaddr, | |
1786 | CORE_ADDR address) | |
1787 | { | |
1788 | struct value *v = allocate_value (type); | |
1789 | if (valaddr == NULL) | |
1790 | set_value_lazy (v, 1); | |
1791 | else | |
1792 | memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type)); | |
1793 | VALUE_ADDRESS (v) = address; | |
33d502b4 | 1794 | VALUE_LVAL (v) = lval_memory; |
8acb6b92 TT |
1795 | return v; |
1796 | } | |
1797 | ||
f23631e4 | 1798 | struct value * |
fba45db2 | 1799 | value_from_double (struct type *type, DOUBLEST num) |
c906108c | 1800 | { |
f23631e4 | 1801 | struct value *val = allocate_value (type); |
c906108c | 1802 | struct type *base_type = check_typedef (type); |
52f0bd74 AC |
1803 | enum type_code code = TYPE_CODE (base_type); |
1804 | int len = TYPE_LENGTH (base_type); | |
c906108c SS |
1805 | |
1806 | if (code == TYPE_CODE_FLT) | |
1807 | { | |
990a07ab | 1808 | store_typed_floating (value_contents_raw (val), base_type, num); |
c906108c SS |
1809 | } |
1810 | else | |
8a3fe4f8 | 1811 | error (_("Unexpected type encountered for floating constant.")); |
c906108c SS |
1812 | |
1813 | return val; | |
1814 | } | |
994b9211 | 1815 | |
27bc4d80 | 1816 | struct value * |
4ef30785 | 1817 | value_from_decfloat (struct type *type, const gdb_byte *dec) |
27bc4d80 TJB |
1818 | { |
1819 | struct value *val = allocate_value (type); | |
27bc4d80 | 1820 | |
4ef30785 | 1821 | memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type)); |
27bc4d80 | 1822 | |
27bc4d80 TJB |
1823 | return val; |
1824 | } | |
1825 | ||
994b9211 AC |
1826 | struct value * |
1827 | coerce_ref (struct value *arg) | |
1828 | { | |
df407dfe | 1829 | struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
994b9211 AC |
1830 | if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) |
1831 | arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), | |
df407dfe | 1832 | unpack_pointer (value_type (arg), |
0fd88904 | 1833 | value_contents (arg))); |
994b9211 AC |
1834 | return arg; |
1835 | } | |
1836 | ||
1837 | struct value * | |
1838 | coerce_array (struct value *arg) | |
1839 | { | |
f3134b88 TT |
1840 | struct type *type; |
1841 | ||
994b9211 | 1842 | arg = coerce_ref (arg); |
f3134b88 TT |
1843 | type = check_typedef (value_type (arg)); |
1844 | ||
1845 | switch (TYPE_CODE (type)) | |
1846 | { | |
1847 | case TYPE_CODE_ARRAY: | |
1848 | if (current_language->c_style_arrays) | |
1849 | arg = value_coerce_array (arg); | |
1850 | break; | |
1851 | case TYPE_CODE_FUNC: | |
1852 | arg = value_coerce_function (arg); | |
1853 | break; | |
1854 | } | |
994b9211 AC |
1855 | return arg; |
1856 | } | |
c906108c | 1857 | \f |
c906108c | 1858 | |
48436ce6 AC |
1859 | /* Return true if the function returning the specified type is using |
1860 | the convention of returning structures in memory (passing in the | |
82585c72 | 1861 | address as a hidden first parameter). */ |
c906108c SS |
1862 | |
1863 | int | |
c055b101 | 1864 | using_struct_return (struct type *func_type, struct type *value_type) |
c906108c | 1865 | { |
52f0bd74 | 1866 | enum type_code code = TYPE_CODE (value_type); |
c906108c SS |
1867 | |
1868 | if (code == TYPE_CODE_ERROR) | |
8a3fe4f8 | 1869 | error (_("Function return type unknown.")); |
c906108c | 1870 | |
667e784f AC |
1871 | if (code == TYPE_CODE_VOID) |
1872 | /* A void return value is never in memory. See also corresponding | |
44e5158b | 1873 | code in "print_return_value". */ |
667e784f AC |
1874 | return 0; |
1875 | ||
92ad9cd9 | 1876 | /* Probe the architecture for the return-value convention. */ |
c055b101 | 1877 | return (gdbarch_return_value (current_gdbarch, func_type, value_type, |
92ad9cd9 | 1878 | NULL, NULL, NULL) |
31db7b6c | 1879 | != RETURN_VALUE_REGISTER_CONVENTION); |
c906108c SS |
1880 | } |
1881 | ||
42be36b3 CT |
1882 | /* Set the initialized field in a value struct. */ |
1883 | ||
1884 | void | |
1885 | set_value_initialized (struct value *val, int status) | |
1886 | { | |
1887 | val->initialized = status; | |
1888 | } | |
1889 | ||
1890 | /* Return the initialized field in a value struct. */ | |
1891 | ||
1892 | int | |
1893 | value_initialized (struct value *val) | |
1894 | { | |
1895 | return val->initialized; | |
1896 | } | |
1897 | ||
c906108c | 1898 | void |
fba45db2 | 1899 | _initialize_values (void) |
c906108c | 1900 | { |
1a966eab AC |
1901 | add_cmd ("convenience", no_class, show_convenience, _("\ |
1902 | Debugger convenience (\"$foo\") variables.\n\ | |
c906108c | 1903 | These variables are created when you assign them values;\n\ |
1a966eab AC |
1904 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\ |
1905 | \n\ | |
c906108c SS |
1906 | A few convenience variables are given values automatically:\n\ |
1907 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1a966eab | 1908 | \"$__\" holds the contents of the last address examined with \"x\"."), |
c906108c SS |
1909 | &showlist); |
1910 | ||
1911 | add_cmd ("values", no_class, show_values, | |
1a966eab | 1912 | _("Elements of value history around item number IDX (or last ten)."), |
c906108c | 1913 | &showlist); |
53e5f3cf AS |
1914 | |
1915 | add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\ | |
1916 | Initialize a convenience variable if necessary.\n\ | |
1917 | init-if-undefined VARIABLE = EXPRESSION\n\ | |
1918 | Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\ | |
1919 | exist or does not contain a value. The EXPRESSION is not evaluated if the\n\ | |
1920 | VARIABLE is already initialized.")); | |
c906108c | 1921 | } |