Commit | Line | Data |
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c906108c | 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
1bac305b | 2 | |
f23631e4 | 3 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, |
990a07ab AC |
4 | 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005 Free |
5 | 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 | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
c906108c | 13 | |
c5aa993b JM |
14 | This program is distributed in the hope that it will be useful, |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
c906108c | 18 | |
c5aa993b JM |
19 | You should have received a copy of the GNU General Public License |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
23 | |
24 | #include "defs.h" | |
25 | #include "gdb_string.h" | |
26 | #include "symtab.h" | |
27 | #include "gdbtypes.h" | |
28 | #include "value.h" | |
29 | #include "gdbcore.h" | |
c906108c SS |
30 | #include "command.h" |
31 | #include "gdbcmd.h" | |
32 | #include "target.h" | |
33 | #include "language.h" | |
34 | #include "scm-lang.h" | |
35 | #include "demangle.h" | |
d16aafd8 | 36 | #include "doublest.h" |
5ae326fa | 37 | #include "gdb_assert.h" |
36160dc4 | 38 | #include "regcache.h" |
fe898f56 | 39 | #include "block.h" |
c906108c SS |
40 | |
41 | /* Prototypes for exported functions. */ | |
42 | ||
a14ed312 | 43 | void _initialize_values (void); |
c906108c | 44 | |
91294c83 AC |
45 | struct value |
46 | { | |
47 | /* Type of value; either not an lval, or one of the various | |
48 | different possible kinds of lval. */ | |
49 | enum lval_type lval; | |
50 | ||
51 | /* Is it modifiable? Only relevant if lval != not_lval. */ | |
52 | int modifiable; | |
53 | ||
54 | /* Location of value (if lval). */ | |
55 | union | |
56 | { | |
57 | /* If lval == lval_memory, this is the address in the inferior. | |
58 | If lval == lval_register, this is the byte offset into the | |
59 | registers structure. */ | |
60 | CORE_ADDR address; | |
61 | ||
62 | /* Pointer to internal variable. */ | |
63 | struct internalvar *internalvar; | |
64 | } location; | |
65 | ||
66 | /* Describes offset of a value within lval of a structure in bytes. | |
67 | If lval == lval_memory, this is an offset to the address. If | |
68 | lval == lval_register, this is a further offset from | |
69 | location.address within the registers structure. Note also the | |
70 | member embedded_offset below. */ | |
71 | int offset; | |
72 | ||
73 | /* Only used for bitfields; number of bits contained in them. */ | |
74 | int bitsize; | |
75 | ||
76 | /* Only used for bitfields; position of start of field. For | |
77 | BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. For | |
78 | BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */ | |
79 | int bitpos; | |
80 | ||
81 | /* Frame register value is relative to. This will be described in | |
82 | the lval enum above as "lval_register". */ | |
83 | struct frame_id frame_id; | |
84 | ||
85 | /* Type of the value. */ | |
86 | struct type *type; | |
87 | ||
88 | /* If a value represents a C++ object, then the `type' field gives | |
89 | the object's compile-time type. If the object actually belongs | |
90 | to some class derived from `type', perhaps with other base | |
91 | classes and additional members, then `type' is just a subobject | |
92 | of the real thing, and the full object is probably larger than | |
93 | `type' would suggest. | |
94 | ||
95 | If `type' is a dynamic class (i.e. one with a vtable), then GDB | |
96 | can actually determine the object's run-time type by looking at | |
97 | the run-time type information in the vtable. When this | |
98 | information is available, we may elect to read in the entire | |
99 | object, for several reasons: | |
100 | ||
101 | - When printing the value, the user would probably rather see the | |
102 | full object, not just the limited portion apparent from the | |
103 | compile-time type. | |
104 | ||
105 | - If `type' has virtual base classes, then even printing `type' | |
106 | alone may require reaching outside the `type' portion of the | |
107 | object to wherever the virtual base class has been stored. | |
108 | ||
109 | When we store the entire object, `enclosing_type' is the run-time | |
110 | type -- the complete object -- and `embedded_offset' is the | |
111 | offset of `type' within that larger type, in bytes. The | |
112 | value_contents() macro takes `embedded_offset' into account, so | |
113 | most GDB code continues to see the `type' portion of the value, | |
114 | just as the inferior would. | |
115 | ||
116 | If `type' is a pointer to an object, then `enclosing_type' is a | |
117 | pointer to the object's run-time type, and `pointed_to_offset' is | |
118 | the offset in bytes from the full object to the pointed-to object | |
119 | -- that is, the value `embedded_offset' would have if we followed | |
120 | the pointer and fetched the complete object. (I don't really see | |
121 | the point. Why not just determine the run-time type when you | |
122 | indirect, and avoid the special case? The contents don't matter | |
123 | until you indirect anyway.) | |
124 | ||
125 | If we're not doing anything fancy, `enclosing_type' is equal to | |
126 | `type', and `embedded_offset' is zero, so everything works | |
127 | normally. */ | |
128 | struct type *enclosing_type; | |
129 | int embedded_offset; | |
130 | int pointed_to_offset; | |
131 | ||
132 | /* Values are stored in a chain, so that they can be deleted easily | |
133 | over calls to the inferior. Values assigned to internal | |
134 | variables or put into the value history are taken off this | |
135 | list. */ | |
136 | struct value *next; | |
137 | ||
138 | /* Register number if the value is from a register. */ | |
139 | short regnum; | |
140 | ||
141 | /* If zero, contents of this value are in the contents field. If | |
142 | nonzero, contents are in inferior memory at address in the | |
143 | location.address field plus the offset field (and the lval field | |
144 | should be lval_memory). | |
145 | ||
146 | WARNING: This field is used by the code which handles watchpoints | |
147 | (see breakpoint.c) to decide whether a particular value can be | |
148 | watched by hardware watchpoints. If the lazy flag is set for | |
149 | some member of a value chain, it is assumed that this member of | |
150 | the chain doesn't need to be watched as part of watching the | |
151 | value itself. This is how GDB avoids watching the entire struct | |
152 | or array when the user wants to watch a single struct member or | |
153 | array element. If you ever change the way lazy flag is set and | |
154 | reset, be sure to consider this use as well! */ | |
155 | char lazy; | |
156 | ||
157 | /* If nonzero, this is the value of a variable which does not | |
158 | actually exist in the program. */ | |
159 | char optimized_out; | |
160 | ||
161 | /* Actual contents of the value. For use of this value; setting it | |
162 | uses the stuff above. Not valid if lazy is nonzero. Target | |
163 | byte-order. We force it to be aligned properly for any possible | |
164 | value. Note that a value therefore extends beyond what is | |
165 | declared here. */ | |
166 | union | |
167 | { | |
168 | bfd_byte contents[1]; | |
169 | DOUBLEST force_doublest_align; | |
170 | LONGEST force_longest_align; | |
171 | CORE_ADDR force_core_addr_align; | |
172 | void *force_pointer_align; | |
173 | } aligner; | |
174 | /* Do not add any new members here -- contents above will trash | |
175 | them. */ | |
176 | }; | |
177 | ||
c906108c SS |
178 | /* Prototypes for local functions. */ |
179 | ||
a14ed312 | 180 | static void show_values (char *, int); |
c906108c | 181 | |
a14ed312 | 182 | static void show_convenience (char *, int); |
c906108c | 183 | |
c906108c SS |
184 | |
185 | /* The value-history records all the values printed | |
186 | by print commands during this session. Each chunk | |
187 | records 60 consecutive values. The first chunk on | |
188 | the chain records the most recent values. | |
189 | The total number of values is in value_history_count. */ | |
190 | ||
191 | #define VALUE_HISTORY_CHUNK 60 | |
192 | ||
193 | struct value_history_chunk | |
c5aa993b JM |
194 | { |
195 | struct value_history_chunk *next; | |
f23631e4 | 196 | struct value *values[VALUE_HISTORY_CHUNK]; |
c5aa993b | 197 | }; |
c906108c SS |
198 | |
199 | /* Chain of chunks now in use. */ | |
200 | ||
201 | static struct value_history_chunk *value_history_chain; | |
202 | ||
203 | static int value_history_count; /* Abs number of last entry stored */ | |
204 | \f | |
205 | /* List of all value objects currently allocated | |
206 | (except for those released by calls to release_value) | |
207 | This is so they can be freed after each command. */ | |
208 | ||
f23631e4 | 209 | static struct value *all_values; |
c906108c SS |
210 | |
211 | /* Allocate a value that has the correct length for type TYPE. */ | |
212 | ||
f23631e4 | 213 | struct value * |
fba45db2 | 214 | allocate_value (struct type *type) |
c906108c | 215 | { |
f23631e4 | 216 | struct value *val; |
c906108c SS |
217 | struct type *atype = check_typedef (type); |
218 | ||
5b90c7b5 | 219 | val = (struct value *) xzalloc (sizeof (struct value) + TYPE_LENGTH (atype)); |
df407dfe | 220 | val->next = all_values; |
c906108c | 221 | all_values = val; |
df407dfe | 222 | val->type = type; |
4754a64e | 223 | val->enclosing_type = type; |
c906108c SS |
224 | VALUE_LVAL (val) = not_lval; |
225 | VALUE_ADDRESS (val) = 0; | |
1df6926e | 226 | VALUE_FRAME_ID (val) = null_frame_id; |
df407dfe AC |
227 | val->offset = 0; |
228 | val->bitpos = 0; | |
229 | val->bitsize = 0; | |
9ee8fc9d | 230 | VALUE_REGNUM (val) = -1; |
d69fe07e | 231 | val->lazy = 0; |
feb13ab0 | 232 | val->optimized_out = 0; |
13c3b5f5 | 233 | val->embedded_offset = 0; |
b44d461b | 234 | val->pointed_to_offset = 0; |
c906108c SS |
235 | val->modifiable = 1; |
236 | return val; | |
237 | } | |
238 | ||
239 | /* Allocate a value that has the correct length | |
240 | for COUNT repetitions type TYPE. */ | |
241 | ||
f23631e4 | 242 | struct value * |
fba45db2 | 243 | allocate_repeat_value (struct type *type, int count) |
c906108c | 244 | { |
c5aa993b | 245 | int low_bound = current_language->string_lower_bound; /* ??? */ |
c906108c SS |
246 | /* FIXME-type-allocation: need a way to free this type when we are |
247 | done with it. */ | |
248 | struct type *range_type | |
c5aa993b JM |
249 | = create_range_type ((struct type *) NULL, builtin_type_int, |
250 | low_bound, count + low_bound - 1); | |
c906108c SS |
251 | /* FIXME-type-allocation: need a way to free this type when we are |
252 | done with it. */ | |
253 | return allocate_value (create_array_type ((struct type *) NULL, | |
254 | type, range_type)); | |
255 | } | |
256 | ||
df407dfe AC |
257 | /* Accessor methods. */ |
258 | ||
17cf0ecd AC |
259 | struct value * |
260 | value_next (struct value *value) | |
261 | { | |
262 | return value->next; | |
263 | } | |
264 | ||
df407dfe AC |
265 | struct type * |
266 | value_type (struct value *value) | |
267 | { | |
268 | return value->type; | |
269 | } | |
04624583 AC |
270 | void |
271 | deprecated_set_value_type (struct value *value, struct type *type) | |
272 | { | |
273 | value->type = type; | |
274 | } | |
df407dfe AC |
275 | |
276 | int | |
277 | value_offset (struct value *value) | |
278 | { | |
279 | return value->offset; | |
280 | } | |
f5cf64a7 AC |
281 | void |
282 | set_value_offset (struct value *value, int offset) | |
283 | { | |
284 | value->offset = offset; | |
285 | } | |
df407dfe AC |
286 | |
287 | int | |
288 | value_bitpos (struct value *value) | |
289 | { | |
290 | return value->bitpos; | |
291 | } | |
9bbda503 AC |
292 | void |
293 | set_value_bitpos (struct value *value, int bit) | |
294 | { | |
295 | value->bitpos = bit; | |
296 | } | |
df407dfe AC |
297 | |
298 | int | |
299 | value_bitsize (struct value *value) | |
300 | { | |
301 | return value->bitsize; | |
302 | } | |
9bbda503 AC |
303 | void |
304 | set_value_bitsize (struct value *value, int bit) | |
305 | { | |
306 | value->bitsize = bit; | |
307 | } | |
df407dfe | 308 | |
990a07ab AC |
309 | bfd_byte * |
310 | value_contents_raw (struct value *value) | |
311 | { | |
312 | return value->aligner.contents + value->embedded_offset; | |
313 | } | |
314 | ||
315 | bfd_byte * | |
316 | value_contents_all_raw (struct value *value) | |
317 | { | |
318 | return value->aligner.contents; | |
319 | } | |
320 | ||
4754a64e AC |
321 | struct type * |
322 | value_enclosing_type (struct value *value) | |
323 | { | |
324 | return value->enclosing_type; | |
325 | } | |
326 | ||
46615f07 AC |
327 | const bfd_byte * |
328 | value_contents_all (struct value *value) | |
329 | { | |
330 | if (value->lazy) | |
331 | value_fetch_lazy (value); | |
332 | return value->aligner.contents; | |
333 | } | |
334 | ||
d69fe07e AC |
335 | int |
336 | value_lazy (struct value *value) | |
337 | { | |
338 | return value->lazy; | |
339 | } | |
340 | ||
dfa52d88 AC |
341 | void |
342 | set_value_lazy (struct value *value, int val) | |
343 | { | |
344 | value->lazy = val; | |
345 | } | |
346 | ||
0fd88904 AC |
347 | const bfd_byte * |
348 | value_contents (struct value *value) | |
349 | { | |
350 | return value_contents_writeable (value); | |
351 | } | |
352 | ||
353 | bfd_byte * | |
354 | value_contents_writeable (struct value *value) | |
355 | { | |
356 | if (value->lazy) | |
357 | value_fetch_lazy (value); | |
358 | return value->aligner.contents; | |
359 | } | |
360 | ||
feb13ab0 AC |
361 | int |
362 | value_optimized_out (struct value *value) | |
363 | { | |
364 | return value->optimized_out; | |
365 | } | |
366 | ||
367 | void | |
368 | set_value_optimized_out (struct value *value, int val) | |
369 | { | |
370 | value->optimized_out = val; | |
371 | } | |
13c3b5f5 AC |
372 | |
373 | int | |
374 | value_embedded_offset (struct value *value) | |
375 | { | |
376 | return value->embedded_offset; | |
377 | } | |
378 | ||
379 | void | |
380 | set_value_embedded_offset (struct value *value, int val) | |
381 | { | |
382 | value->embedded_offset = val; | |
383 | } | |
b44d461b AC |
384 | |
385 | int | |
386 | value_pointed_to_offset (struct value *value) | |
387 | { | |
388 | return value->pointed_to_offset; | |
389 | } | |
390 | ||
391 | void | |
392 | set_value_pointed_to_offset (struct value *value, int val) | |
393 | { | |
394 | value->pointed_to_offset = val; | |
395 | } | |
13bb5560 AC |
396 | |
397 | enum lval_type * | |
398 | deprecated_value_lval_hack (struct value *value) | |
399 | { | |
400 | return &value->lval; | |
401 | } | |
402 | ||
403 | CORE_ADDR * | |
404 | deprecated_value_address_hack (struct value *value) | |
405 | { | |
406 | return &value->location.address; | |
407 | } | |
408 | ||
409 | struct internalvar ** | |
410 | deprecated_value_internalvar_hack (struct value *value) | |
411 | { | |
412 | return &value->location.internalvar; | |
413 | } | |
414 | ||
415 | struct frame_id * | |
416 | deprecated_value_frame_id_hack (struct value *value) | |
417 | { | |
418 | return &value->frame_id; | |
419 | } | |
420 | ||
421 | short * | |
422 | deprecated_value_regnum_hack (struct value *value) | |
423 | { | |
424 | return &value->regnum; | |
425 | } | |
88e3b34b AC |
426 | |
427 | int | |
428 | deprecated_value_modifiable (struct value *value) | |
429 | { | |
430 | return value->modifiable; | |
431 | } | |
432 | void | |
433 | deprecated_set_value_modifiable (struct value *value, int modifiable) | |
434 | { | |
435 | value->modifiable = modifiable; | |
436 | } | |
990a07ab | 437 | \f |
c906108c SS |
438 | /* Return a mark in the value chain. All values allocated after the |
439 | mark is obtained (except for those released) are subject to being freed | |
440 | if a subsequent value_free_to_mark is passed the mark. */ | |
f23631e4 | 441 | struct value * |
fba45db2 | 442 | value_mark (void) |
c906108c SS |
443 | { |
444 | return all_values; | |
445 | } | |
446 | ||
447 | /* Free all values allocated since MARK was obtained by value_mark | |
448 | (except for those released). */ | |
449 | void | |
f23631e4 | 450 | value_free_to_mark (struct value *mark) |
c906108c | 451 | { |
f23631e4 AC |
452 | struct value *val; |
453 | struct value *next; | |
c906108c SS |
454 | |
455 | for (val = all_values; val && val != mark; val = next) | |
456 | { | |
df407dfe | 457 | next = val->next; |
c906108c SS |
458 | value_free (val); |
459 | } | |
460 | all_values = val; | |
461 | } | |
462 | ||
463 | /* Free all the values that have been allocated (except for those released). | |
464 | Called after each command, successful or not. */ | |
465 | ||
466 | void | |
fba45db2 | 467 | free_all_values (void) |
c906108c | 468 | { |
f23631e4 AC |
469 | struct value *val; |
470 | struct value *next; | |
c906108c SS |
471 | |
472 | for (val = all_values; val; val = next) | |
473 | { | |
df407dfe | 474 | next = val->next; |
c906108c SS |
475 | value_free (val); |
476 | } | |
477 | ||
478 | all_values = 0; | |
479 | } | |
480 | ||
481 | /* Remove VAL from the chain all_values | |
482 | so it will not be freed automatically. */ | |
483 | ||
484 | void | |
f23631e4 | 485 | release_value (struct value *val) |
c906108c | 486 | { |
f23631e4 | 487 | struct value *v; |
c906108c SS |
488 | |
489 | if (all_values == val) | |
490 | { | |
491 | all_values = val->next; | |
492 | return; | |
493 | } | |
494 | ||
495 | for (v = all_values; v; v = v->next) | |
496 | { | |
497 | if (v->next == val) | |
498 | { | |
499 | v->next = val->next; | |
500 | break; | |
501 | } | |
502 | } | |
503 | } | |
504 | ||
505 | /* Release all values up to mark */ | |
f23631e4 AC |
506 | struct value * |
507 | value_release_to_mark (struct value *mark) | |
c906108c | 508 | { |
f23631e4 AC |
509 | struct value *val; |
510 | struct value *next; | |
c906108c | 511 | |
df407dfe AC |
512 | for (val = next = all_values; next; next = next->next) |
513 | if (next->next == mark) | |
c906108c | 514 | { |
df407dfe AC |
515 | all_values = next->next; |
516 | next->next = NULL; | |
c906108c SS |
517 | return val; |
518 | } | |
519 | all_values = 0; | |
520 | return val; | |
521 | } | |
522 | ||
523 | /* Return a copy of the value ARG. | |
524 | It contains the same contents, for same memory address, | |
525 | but it's a different block of storage. */ | |
526 | ||
f23631e4 AC |
527 | struct value * |
528 | value_copy (struct value *arg) | |
c906108c | 529 | { |
4754a64e | 530 | struct type *encl_type = value_enclosing_type (arg); |
f23631e4 | 531 | struct value *val = allocate_value (encl_type); |
df407dfe | 532 | val->type = arg->type; |
c906108c SS |
533 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
534 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); | |
df407dfe AC |
535 | val->offset = arg->offset; |
536 | val->bitpos = arg->bitpos; | |
537 | val->bitsize = arg->bitsize; | |
1df6926e | 538 | VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
9ee8fc9d | 539 | VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
d69fe07e | 540 | val->lazy = arg->lazy; |
feb13ab0 | 541 | val->optimized_out = arg->optimized_out; |
13c3b5f5 | 542 | val->embedded_offset = value_embedded_offset (arg); |
b44d461b | 543 | val->pointed_to_offset = arg->pointed_to_offset; |
c906108c | 544 | val->modifiable = arg->modifiable; |
d69fe07e | 545 | if (!value_lazy (val)) |
c906108c | 546 | { |
990a07ab | 547 | memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
4754a64e | 548 | TYPE_LENGTH (value_enclosing_type (arg))); |
c906108c SS |
549 | |
550 | } | |
551 | return val; | |
552 | } | |
553 | \f | |
554 | /* Access to the value history. */ | |
555 | ||
556 | /* Record a new value in the value history. | |
557 | Returns the absolute history index of the entry. | |
558 | Result of -1 indicates the value was not saved; otherwise it is the | |
559 | value history index of this new item. */ | |
560 | ||
561 | int | |
f23631e4 | 562 | record_latest_value (struct value *val) |
c906108c SS |
563 | { |
564 | int i; | |
565 | ||
566 | /* We don't want this value to have anything to do with the inferior anymore. | |
567 | In particular, "set $1 = 50" should not affect the variable from which | |
568 | the value was taken, and fast watchpoints should be able to assume that | |
569 | a value on the value history never changes. */ | |
d69fe07e | 570 | if (value_lazy (val)) |
c906108c SS |
571 | value_fetch_lazy (val); |
572 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched | |
573 | from. This is a bit dubious, because then *&$1 does not just return $1 | |
574 | but the current contents of that location. c'est la vie... */ | |
575 | val->modifiable = 0; | |
576 | release_value (val); | |
577 | ||
578 | /* Here we treat value_history_count as origin-zero | |
579 | and applying to the value being stored now. */ | |
580 | ||
581 | i = value_history_count % VALUE_HISTORY_CHUNK; | |
582 | if (i == 0) | |
583 | { | |
f23631e4 | 584 | struct value_history_chunk *new |
c5aa993b JM |
585 | = (struct value_history_chunk *) |
586 | xmalloc (sizeof (struct value_history_chunk)); | |
c906108c SS |
587 | memset (new->values, 0, sizeof new->values); |
588 | new->next = value_history_chain; | |
589 | value_history_chain = new; | |
590 | } | |
591 | ||
592 | value_history_chain->values[i] = val; | |
593 | ||
594 | /* Now we regard value_history_count as origin-one | |
595 | and applying to the value just stored. */ | |
596 | ||
597 | return ++value_history_count; | |
598 | } | |
599 | ||
600 | /* Return a copy of the value in the history with sequence number NUM. */ | |
601 | ||
f23631e4 | 602 | struct value * |
fba45db2 | 603 | access_value_history (int num) |
c906108c | 604 | { |
f23631e4 | 605 | struct value_history_chunk *chunk; |
52f0bd74 AC |
606 | int i; |
607 | int absnum = num; | |
c906108c SS |
608 | |
609 | if (absnum <= 0) | |
610 | absnum += value_history_count; | |
611 | ||
612 | if (absnum <= 0) | |
613 | { | |
614 | if (num == 0) | |
8a3fe4f8 | 615 | error (_("The history is empty.")); |
c906108c | 616 | else if (num == 1) |
8a3fe4f8 | 617 | error (_("There is only one value in the history.")); |
c906108c | 618 | else |
8a3fe4f8 | 619 | error (_("History does not go back to $$%d."), -num); |
c906108c SS |
620 | } |
621 | if (absnum > value_history_count) | |
8a3fe4f8 | 622 | error (_("History has not yet reached $%d."), absnum); |
c906108c SS |
623 | |
624 | absnum--; | |
625 | ||
626 | /* Now absnum is always absolute and origin zero. */ | |
627 | ||
628 | chunk = value_history_chain; | |
629 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; | |
630 | i > 0; i--) | |
631 | chunk = chunk->next; | |
632 | ||
633 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); | |
634 | } | |
635 | ||
636 | /* Clear the value history entirely. | |
637 | Must be done when new symbol tables are loaded, | |
638 | because the type pointers become invalid. */ | |
639 | ||
640 | void | |
fba45db2 | 641 | clear_value_history (void) |
c906108c | 642 | { |
f23631e4 | 643 | struct value_history_chunk *next; |
52f0bd74 | 644 | int i; |
f23631e4 | 645 | struct value *val; |
c906108c SS |
646 | |
647 | while (value_history_chain) | |
648 | { | |
649 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) | |
650 | if ((val = value_history_chain->values[i]) != NULL) | |
b8c9b27d | 651 | xfree (val); |
c906108c | 652 | next = value_history_chain->next; |
b8c9b27d | 653 | xfree (value_history_chain); |
c906108c SS |
654 | value_history_chain = next; |
655 | } | |
656 | value_history_count = 0; | |
657 | } | |
658 | ||
659 | static void | |
fba45db2 | 660 | show_values (char *num_exp, int from_tty) |
c906108c | 661 | { |
52f0bd74 | 662 | int i; |
f23631e4 | 663 | struct value *val; |
c906108c SS |
664 | static int num = 1; |
665 | ||
666 | if (num_exp) | |
667 | { | |
c5aa993b JM |
668 | /* "info history +" should print from the stored position. |
669 | "info history <exp>" should print around value number <exp>. */ | |
c906108c | 670 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
bb518678 | 671 | num = parse_and_eval_long (num_exp) - 5; |
c906108c SS |
672 | } |
673 | else | |
674 | { | |
675 | /* "info history" means print the last 10 values. */ | |
676 | num = value_history_count - 9; | |
677 | } | |
678 | ||
679 | if (num <= 0) | |
680 | num = 1; | |
681 | ||
682 | for (i = num; i < num + 10 && i <= value_history_count; i++) | |
683 | { | |
684 | val = access_value_history (i); | |
a3f17187 | 685 | printf_filtered (("$%d = "), i); |
c906108c | 686 | value_print (val, gdb_stdout, 0, Val_pretty_default); |
a3f17187 | 687 | printf_filtered (("\n")); |
c906108c SS |
688 | } |
689 | ||
690 | /* The next "info history +" should start after what we just printed. */ | |
691 | num += 10; | |
692 | ||
693 | /* Hitting just return after this command should do the same thing as | |
694 | "info history +". If num_exp is null, this is unnecessary, since | |
695 | "info history +" is not useful after "info history". */ | |
696 | if (from_tty && num_exp) | |
697 | { | |
698 | num_exp[0] = '+'; | |
699 | num_exp[1] = '\0'; | |
700 | } | |
701 | } | |
702 | \f | |
703 | /* Internal variables. These are variables within the debugger | |
704 | that hold values assigned by debugger commands. | |
705 | The user refers to them with a '$' prefix | |
706 | that does not appear in the variable names stored internally. */ | |
707 | ||
708 | static struct internalvar *internalvars; | |
709 | ||
710 | /* Look up an internal variable with name NAME. NAME should not | |
711 | normally include a dollar sign. | |
712 | ||
713 | If the specified internal variable does not exist, | |
714 | one is created, with a void value. */ | |
715 | ||
716 | struct internalvar * | |
fba45db2 | 717 | lookup_internalvar (char *name) |
c906108c | 718 | { |
52f0bd74 | 719 | struct internalvar *var; |
c906108c SS |
720 | |
721 | for (var = internalvars; var; var = var->next) | |
5cb316ef | 722 | if (strcmp (var->name, name) == 0) |
c906108c SS |
723 | return var; |
724 | ||
725 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); | |
726 | var->name = concat (name, NULL); | |
727 | var->value = allocate_value (builtin_type_void); | |
728 | release_value (var->value); | |
729 | var->next = internalvars; | |
730 | internalvars = var; | |
731 | return var; | |
732 | } | |
733 | ||
f23631e4 | 734 | struct value * |
fba45db2 | 735 | value_of_internalvar (struct internalvar *var) |
c906108c | 736 | { |
f23631e4 | 737 | struct value *val; |
c906108c | 738 | |
c906108c | 739 | val = value_copy (var->value); |
d69fe07e | 740 | if (value_lazy (val)) |
c906108c SS |
741 | value_fetch_lazy (val); |
742 | VALUE_LVAL (val) = lval_internalvar; | |
743 | VALUE_INTERNALVAR (val) = var; | |
744 | return val; | |
745 | } | |
746 | ||
747 | void | |
fba45db2 | 748 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
f23631e4 | 749 | int bitsize, struct value *newval) |
c906108c | 750 | { |
0fd88904 | 751 | bfd_byte *addr = value_contents_writeable (var->value) + offset; |
c906108c | 752 | |
c906108c SS |
753 | if (bitsize) |
754 | modify_field (addr, value_as_long (newval), | |
755 | bitpos, bitsize); | |
756 | else | |
0fd88904 | 757 | memcpy (addr, value_contents (newval), TYPE_LENGTH (value_type (newval))); |
c906108c SS |
758 | } |
759 | ||
760 | void | |
f23631e4 | 761 | set_internalvar (struct internalvar *var, struct value *val) |
c906108c | 762 | { |
f23631e4 | 763 | struct value *newval; |
c906108c | 764 | |
c906108c SS |
765 | newval = value_copy (val); |
766 | newval->modifiable = 1; | |
767 | ||
768 | /* Force the value to be fetched from the target now, to avoid problems | |
769 | later when this internalvar is referenced and the target is gone or | |
770 | has changed. */ | |
d69fe07e | 771 | if (value_lazy (newval)) |
c906108c SS |
772 | value_fetch_lazy (newval); |
773 | ||
774 | /* Begin code which must not call error(). If var->value points to | |
775 | something free'd, an error() obviously leaves a dangling pointer. | |
776 | But we also get a danling pointer if var->value points to | |
777 | something in the value chain (i.e., before release_value is | |
778 | called), because after the error free_all_values will get called before | |
779 | long. */ | |
b8c9b27d | 780 | xfree (var->value); |
c906108c SS |
781 | var->value = newval; |
782 | release_value (newval); | |
783 | /* End code which must not call error(). */ | |
784 | } | |
785 | ||
786 | char * | |
fba45db2 | 787 | internalvar_name (struct internalvar *var) |
c906108c SS |
788 | { |
789 | return var->name; | |
790 | } | |
791 | ||
792 | /* Free all internalvars. Done when new symtabs are loaded, | |
793 | because that makes the values invalid. */ | |
794 | ||
795 | void | |
fba45db2 | 796 | clear_internalvars (void) |
c906108c | 797 | { |
52f0bd74 | 798 | struct internalvar *var; |
c906108c SS |
799 | |
800 | while (internalvars) | |
801 | { | |
802 | var = internalvars; | |
803 | internalvars = var->next; | |
b8c9b27d KB |
804 | xfree (var->name); |
805 | xfree (var->value); | |
806 | xfree (var); | |
c906108c SS |
807 | } |
808 | } | |
809 | ||
810 | static void | |
fba45db2 | 811 | show_convenience (char *ignore, int from_tty) |
c906108c | 812 | { |
52f0bd74 | 813 | struct internalvar *var; |
c906108c SS |
814 | int varseen = 0; |
815 | ||
816 | for (var = internalvars; var; var = var->next) | |
817 | { | |
c906108c SS |
818 | if (!varseen) |
819 | { | |
820 | varseen = 1; | |
821 | } | |
a3f17187 | 822 | printf_filtered (("$%s = "), var->name); |
c906108c | 823 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); |
a3f17187 | 824 | printf_filtered (("\n")); |
c906108c SS |
825 | } |
826 | if (!varseen) | |
a3f17187 AC |
827 | printf_unfiltered (_("\ |
828 | No debugger convenience variables now defined.\n\ | |
c906108c | 829 | Convenience variables have names starting with \"$\";\n\ |
a3f17187 | 830 | use \"set\" as in \"set $foo = 5\" to define them.\n")); |
c906108c SS |
831 | } |
832 | \f | |
833 | /* Extract a value as a C number (either long or double). | |
834 | Knows how to convert fixed values to double, or | |
835 | floating values to long. | |
836 | Does not deallocate the value. */ | |
837 | ||
838 | LONGEST | |
f23631e4 | 839 | value_as_long (struct value *val) |
c906108c SS |
840 | { |
841 | /* This coerces arrays and functions, which is necessary (e.g. | |
842 | in disassemble_command). It also dereferences references, which | |
843 | I suspect is the most logical thing to do. */ | |
994b9211 | 844 | val = coerce_array (val); |
0fd88904 | 845 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
846 | } |
847 | ||
848 | DOUBLEST | |
f23631e4 | 849 | value_as_double (struct value *val) |
c906108c SS |
850 | { |
851 | DOUBLEST foo; | |
852 | int inv; | |
c5aa993b | 853 | |
0fd88904 | 854 | foo = unpack_double (value_type (val), value_contents (val), &inv); |
c906108c | 855 | if (inv) |
8a3fe4f8 | 856 | error (_("Invalid floating value found in program.")); |
c906108c SS |
857 | return foo; |
858 | } | |
4478b372 JB |
859 | /* Extract a value as a C pointer. Does not deallocate the value. |
860 | Note that val's type may not actually be a pointer; value_as_long | |
861 | handles all the cases. */ | |
c906108c | 862 | CORE_ADDR |
f23631e4 | 863 | value_as_address (struct value *val) |
c906108c SS |
864 | { |
865 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
866 | whether we want this to be true eventually. */ | |
867 | #if 0 | |
868 | /* ADDR_BITS_REMOVE is wrong if we are being called for a | |
869 | non-address (e.g. argument to "signal", "info break", etc.), or | |
870 | for pointers to char, in which the low bits *are* significant. */ | |
c5aa993b | 871 | return ADDR_BITS_REMOVE (value_as_long (val)); |
c906108c | 872 | #else |
f312f057 JB |
873 | |
874 | /* There are several targets (IA-64, PowerPC, and others) which | |
875 | don't represent pointers to functions as simply the address of | |
876 | the function's entry point. For example, on the IA-64, a | |
877 | function pointer points to a two-word descriptor, generated by | |
878 | the linker, which contains the function's entry point, and the | |
879 | value the IA-64 "global pointer" register should have --- to | |
880 | support position-independent code. The linker generates | |
881 | descriptors only for those functions whose addresses are taken. | |
882 | ||
883 | On such targets, it's difficult for GDB to convert an arbitrary | |
884 | function address into a function pointer; it has to either find | |
885 | an existing descriptor for that function, or call malloc and | |
886 | build its own. On some targets, it is impossible for GDB to | |
887 | build a descriptor at all: the descriptor must contain a jump | |
888 | instruction; data memory cannot be executed; and code memory | |
889 | cannot be modified. | |
890 | ||
891 | Upon entry to this function, if VAL is a value of type `function' | |
892 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then | |
893 | VALUE_ADDRESS (val) is the address of the function. This is what | |
894 | you'll get if you evaluate an expression like `main'. The call | |
895 | to COERCE_ARRAY below actually does all the usual unary | |
896 | conversions, which includes converting values of type `function' | |
897 | to `pointer to function'. This is the challenging conversion | |
898 | discussed above. Then, `unpack_long' will convert that pointer | |
899 | back into an address. | |
900 | ||
901 | So, suppose the user types `disassemble foo' on an architecture | |
902 | with a strange function pointer representation, on which GDB | |
903 | cannot build its own descriptors, and suppose further that `foo' | |
904 | has no linker-built descriptor. The address->pointer conversion | |
905 | will signal an error and prevent the command from running, even | |
906 | though the next step would have been to convert the pointer | |
907 | directly back into the same address. | |
908 | ||
909 | The following shortcut avoids this whole mess. If VAL is a | |
910 | function, just return its address directly. */ | |
df407dfe AC |
911 | if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
912 | || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) | |
f312f057 JB |
913 | return VALUE_ADDRESS (val); |
914 | ||
994b9211 | 915 | val = coerce_array (val); |
fc0c74b1 AC |
916 | |
917 | /* Some architectures (e.g. Harvard), map instruction and data | |
918 | addresses onto a single large unified address space. For | |
919 | instance: An architecture may consider a large integer in the | |
920 | range 0x10000000 .. 0x1000ffff to already represent a data | |
921 | addresses (hence not need a pointer to address conversion) while | |
922 | a small integer would still need to be converted integer to | |
923 | pointer to address. Just assume such architectures handle all | |
924 | integer conversions in a single function. */ | |
925 | ||
926 | /* JimB writes: | |
927 | ||
928 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we | |
929 | must admonish GDB hackers to make sure its behavior matches the | |
930 | compiler's, whenever possible. | |
931 | ||
932 | In general, I think GDB should evaluate expressions the same way | |
933 | the compiler does. When the user copies an expression out of | |
934 | their source code and hands it to a `print' command, they should | |
935 | get the same value the compiler would have computed. Any | |
936 | deviation from this rule can cause major confusion and annoyance, | |
937 | and needs to be justified carefully. In other words, GDB doesn't | |
938 | really have the freedom to do these conversions in clever and | |
939 | useful ways. | |
940 | ||
941 | AndrewC pointed out that users aren't complaining about how GDB | |
942 | casts integers to pointers; they are complaining that they can't | |
943 | take an address from a disassembly listing and give it to `x/i'. | |
944 | This is certainly important. | |
945 | ||
79dd2d24 | 946 | Adding an architecture method like integer_to_address() certainly |
fc0c74b1 AC |
947 | makes it possible for GDB to "get it right" in all circumstances |
948 | --- the target has complete control over how things get done, so | |
949 | people can Do The Right Thing for their target without breaking | |
950 | anyone else. The standard doesn't specify how integers get | |
951 | converted to pointers; usually, the ABI doesn't either, but | |
952 | ABI-specific code is a more reasonable place to handle it. */ | |
953 | ||
df407dfe AC |
954 | if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
955 | && TYPE_CODE (value_type (val)) != TYPE_CODE_REF | |
79dd2d24 AC |
956 | && gdbarch_integer_to_address_p (current_gdbarch)) |
957 | return gdbarch_integer_to_address (current_gdbarch, value_type (val), | |
0fd88904 | 958 | value_contents (val)); |
fc0c74b1 | 959 | |
0fd88904 | 960 | return unpack_long (value_type (val), value_contents (val)); |
c906108c SS |
961 | #endif |
962 | } | |
963 | \f | |
964 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
965 | as a long, or as a double, assuming the raw data is described | |
966 | by type TYPE. Knows how to convert different sizes of values | |
967 | and can convert between fixed and floating point. We don't assume | |
968 | any alignment for the raw data. Return value is in host byte order. | |
969 | ||
970 | If you want functions and arrays to be coerced to pointers, and | |
971 | references to be dereferenced, call value_as_long() instead. | |
972 | ||
973 | C++: It is assumed that the front-end has taken care of | |
974 | all matters concerning pointers to members. A pointer | |
975 | to member which reaches here is considered to be equivalent | |
976 | to an INT (or some size). After all, it is only an offset. */ | |
977 | ||
978 | LONGEST | |
66140c26 | 979 | unpack_long (struct type *type, const char *valaddr) |
c906108c | 980 | { |
52f0bd74 AC |
981 | enum type_code code = TYPE_CODE (type); |
982 | int len = TYPE_LENGTH (type); | |
983 | int nosign = TYPE_UNSIGNED (type); | |
c906108c SS |
984 | |
985 | if (current_language->la_language == language_scm | |
986 | && is_scmvalue_type (type)) | |
987 | return scm_unpack (type, valaddr, TYPE_CODE_INT); | |
988 | ||
989 | switch (code) | |
990 | { | |
991 | case TYPE_CODE_TYPEDEF: | |
992 | return unpack_long (check_typedef (type), valaddr); | |
993 | case TYPE_CODE_ENUM: | |
994 | case TYPE_CODE_BOOL: | |
995 | case TYPE_CODE_INT: | |
996 | case TYPE_CODE_CHAR: | |
997 | case TYPE_CODE_RANGE: | |
998 | if (nosign) | |
999 | return extract_unsigned_integer (valaddr, len); | |
1000 | else | |
1001 | return extract_signed_integer (valaddr, len); | |
1002 | ||
1003 | case TYPE_CODE_FLT: | |
96d2f608 | 1004 | return extract_typed_floating (valaddr, type); |
c906108c SS |
1005 | |
1006 | case TYPE_CODE_PTR: | |
1007 | case TYPE_CODE_REF: | |
1008 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
c5aa993b | 1009 | whether we want this to be true eventually. */ |
4478b372 | 1010 | return extract_typed_address (valaddr, type); |
c906108c SS |
1011 | |
1012 | case TYPE_CODE_MEMBER: | |
8a3fe4f8 | 1013 | error (_("not implemented: member types in unpack_long")); |
c906108c SS |
1014 | |
1015 | default: | |
8a3fe4f8 | 1016 | error (_("Value can't be converted to integer.")); |
c906108c | 1017 | } |
c5aa993b | 1018 | return 0; /* Placate lint. */ |
c906108c SS |
1019 | } |
1020 | ||
1021 | /* Return a double value from the specified type and address. | |
1022 | INVP points to an int which is set to 0 for valid value, | |
1023 | 1 for invalid value (bad float format). In either case, | |
1024 | the returned double is OK to use. Argument is in target | |
1025 | format, result is in host format. */ | |
1026 | ||
1027 | DOUBLEST | |
66140c26 | 1028 | unpack_double (struct type *type, const char *valaddr, int *invp) |
c906108c SS |
1029 | { |
1030 | enum type_code code; | |
1031 | int len; | |
1032 | int nosign; | |
1033 | ||
1034 | *invp = 0; /* Assume valid. */ | |
1035 | CHECK_TYPEDEF (type); | |
1036 | code = TYPE_CODE (type); | |
1037 | len = TYPE_LENGTH (type); | |
1038 | nosign = TYPE_UNSIGNED (type); | |
1039 | if (code == TYPE_CODE_FLT) | |
1040 | { | |
75bc7ddf AC |
1041 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
1042 | floating-point value was valid (using the macro | |
1043 | INVALID_FLOAT). That test/macro have been removed. | |
1044 | ||
1045 | It turns out that only the VAX defined this macro and then | |
1046 | only in a non-portable way. Fixing the portability problem | |
1047 | wouldn't help since the VAX floating-point code is also badly | |
1048 | bit-rotten. The target needs to add definitions for the | |
1049 | methods TARGET_FLOAT_FORMAT and TARGET_DOUBLE_FORMAT - these | |
1050 | exactly describe the target floating-point format. The | |
1051 | problem here is that the corresponding floatformat_vax_f and | |
1052 | floatformat_vax_d values these methods should be set to are | |
1053 | also not defined either. Oops! | |
1054 | ||
1055 | Hopefully someone will add both the missing floatformat | |
ac79b88b DJ |
1056 | definitions and the new cases for floatformat_is_valid (). */ |
1057 | ||
1058 | if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) | |
1059 | { | |
1060 | *invp = 1; | |
1061 | return 0.0; | |
1062 | } | |
1063 | ||
96d2f608 | 1064 | return extract_typed_floating (valaddr, type); |
c906108c SS |
1065 | } |
1066 | else if (nosign) | |
1067 | { | |
1068 | /* Unsigned -- be sure we compensate for signed LONGEST. */ | |
c906108c | 1069 | return (ULONGEST) unpack_long (type, valaddr); |
c906108c SS |
1070 | } |
1071 | else | |
1072 | { | |
1073 | /* Signed -- we are OK with unpack_long. */ | |
1074 | return unpack_long (type, valaddr); | |
1075 | } | |
1076 | } | |
1077 | ||
1078 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR | |
1079 | as a CORE_ADDR, assuming the raw data is described by type TYPE. | |
1080 | We don't assume any alignment for the raw data. Return value is in | |
1081 | host byte order. | |
1082 | ||
1083 | If you want functions and arrays to be coerced to pointers, and | |
1aa20aa8 | 1084 | references to be dereferenced, call value_as_address() instead. |
c906108c SS |
1085 | |
1086 | C++: It is assumed that the front-end has taken care of | |
1087 | all matters concerning pointers to members. A pointer | |
1088 | to member which reaches here is considered to be equivalent | |
1089 | to an INT (or some size). After all, it is only an offset. */ | |
1090 | ||
1091 | CORE_ADDR | |
66140c26 | 1092 | unpack_pointer (struct type *type, const char *valaddr) |
c906108c SS |
1093 | { |
1094 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
1095 | whether we want this to be true eventually. */ | |
1096 | return unpack_long (type, valaddr); | |
1097 | } | |
4478b372 | 1098 | |
c906108c | 1099 | \f |
2c2738a0 DC |
1100 | /* Get the value of the FIELDN'th field (which must be static) of |
1101 | TYPE. Return NULL if the field doesn't exist or has been | |
1102 | optimized out. */ | |
c906108c | 1103 | |
f23631e4 | 1104 | struct value * |
fba45db2 | 1105 | value_static_field (struct type *type, int fieldno) |
c906108c | 1106 | { |
948e66d9 DJ |
1107 | struct value *retval; |
1108 | ||
c906108c SS |
1109 | if (TYPE_FIELD_STATIC_HAS_ADDR (type, fieldno)) |
1110 | { | |
948e66d9 | 1111 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 1112 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
c906108c SS |
1113 | } |
1114 | else | |
1115 | { | |
1116 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); | |
176620f1 | 1117 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0, NULL); |
948e66d9 | 1118 | if (sym == NULL) |
c906108c SS |
1119 | { |
1120 | /* With some compilers, e.g. HP aCC, static data members are reported | |
c5aa993b JM |
1121 | as non-debuggable symbols */ |
1122 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); | |
c906108c SS |
1123 | if (!msym) |
1124 | return NULL; | |
1125 | else | |
c5aa993b | 1126 | { |
948e66d9 | 1127 | retval = value_at (TYPE_FIELD_TYPE (type, fieldno), |
00a4c844 | 1128 | SYMBOL_VALUE_ADDRESS (msym)); |
c906108c SS |
1129 | } |
1130 | } | |
1131 | else | |
1132 | { | |
948e66d9 DJ |
1133 | /* SYM should never have a SYMBOL_CLASS which will require |
1134 | read_var_value to use the FRAME parameter. */ | |
1135 | if (symbol_read_needs_frame (sym)) | |
8a3fe4f8 AC |
1136 | warning (_("static field's value depends on the current " |
1137 | "frame - bad debug info?")); | |
948e66d9 | 1138 | retval = read_var_value (sym, NULL); |
2b127877 | 1139 | } |
948e66d9 DJ |
1140 | if (retval && VALUE_LVAL (retval) == lval_memory) |
1141 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), | |
1142 | VALUE_ADDRESS (retval)); | |
c906108c | 1143 | } |
948e66d9 | 1144 | return retval; |
c906108c SS |
1145 | } |
1146 | ||
2b127877 DB |
1147 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
1148 | You have to be careful here, since the size of the data area for the value | |
1149 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger | |
1150 | than the old enclosing type, you have to allocate more space for the data. | |
1151 | The return value is a pointer to the new version of this value structure. */ | |
1152 | ||
f23631e4 AC |
1153 | struct value * |
1154 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) | |
2b127877 | 1155 | { |
4754a64e | 1156 | if (TYPE_LENGTH (new_encl_type) <= TYPE_LENGTH (value_enclosing_type (val))) |
2b127877 | 1157 | { |
4754a64e | 1158 | val->enclosing_type = new_encl_type; |
2b127877 DB |
1159 | return val; |
1160 | } | |
1161 | else | |
1162 | { | |
f23631e4 AC |
1163 | struct value *new_val; |
1164 | struct value *prev; | |
2b127877 | 1165 | |
f23631e4 | 1166 | new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type)); |
cc303028 | 1167 | |
4754a64e | 1168 | new_val->enclosing_type = new_encl_type; |
cc303028 | 1169 | |
2b127877 DB |
1170 | /* We have to make sure this ends up in the same place in the value |
1171 | chain as the original copy, so it's clean-up behavior is the same. | |
1172 | If the value has been released, this is a waste of time, but there | |
1173 | is no way to tell that in advance, so... */ | |
1174 | ||
1175 | if (val != all_values) | |
1176 | { | |
1177 | for (prev = all_values; prev != NULL; prev = prev->next) | |
1178 | { | |
1179 | if (prev->next == val) | |
1180 | { | |
1181 | prev->next = new_val; | |
1182 | break; | |
1183 | } | |
1184 | } | |
1185 | } | |
1186 | ||
1187 | return new_val; | |
1188 | } | |
1189 | } | |
1190 | ||
c906108c SS |
1191 | /* Given a value ARG1 (offset by OFFSET bytes) |
1192 | of a struct or union type ARG_TYPE, | |
1193 | extract and return the value of one of its (non-static) fields. | |
1194 | FIELDNO says which field. */ | |
1195 | ||
f23631e4 AC |
1196 | struct value * |
1197 | value_primitive_field (struct value *arg1, int offset, | |
aa1ee363 | 1198 | int fieldno, struct type *arg_type) |
c906108c | 1199 | { |
f23631e4 | 1200 | struct value *v; |
52f0bd74 | 1201 | struct type *type; |
c906108c SS |
1202 | |
1203 | CHECK_TYPEDEF (arg_type); | |
1204 | type = TYPE_FIELD_TYPE (arg_type, fieldno); | |
1205 | ||
1206 | /* Handle packed fields */ | |
1207 | ||
1208 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) | |
1209 | { | |
1210 | v = value_from_longest (type, | |
1211 | unpack_field_as_long (arg_type, | |
0fd88904 | 1212 | value_contents (arg1) |
c5aa993b | 1213 | + offset, |
c906108c | 1214 | fieldno)); |
df407dfe AC |
1215 | v->bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; |
1216 | v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); | |
1217 | v->offset = value_offset (arg1) + offset | |
2e70b7b9 | 1218 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
c906108c SS |
1219 | } |
1220 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) | |
1221 | { | |
1222 | /* This field is actually a base subobject, so preserve the | |
1223 | entire object's contents for later references to virtual | |
1224 | bases, etc. */ | |
4754a64e | 1225 | v = allocate_value (value_enclosing_type (arg1)); |
df407dfe | 1226 | v->type = type; |
d69fe07e | 1227 | if (value_lazy (arg1)) |
dfa52d88 | 1228 | set_value_lazy (v, 1); |
c906108c | 1229 | else |
990a07ab | 1230 | memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1), |
4754a64e | 1231 | TYPE_LENGTH (value_enclosing_type (arg1))); |
df407dfe | 1232 | v->offset = value_offset (arg1); |
13c3b5f5 AC |
1233 | v->embedded_offset = (offset + value_embedded_offset (arg1) |
1234 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8); | |
c906108c SS |
1235 | } |
1236 | else | |
1237 | { | |
1238 | /* Plain old data member */ | |
1239 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; | |
1240 | v = allocate_value (type); | |
d69fe07e | 1241 | if (value_lazy (arg1)) |
dfa52d88 | 1242 | set_value_lazy (v, 1); |
c906108c | 1243 | else |
990a07ab AC |
1244 | memcpy (value_contents_raw (v), |
1245 | value_contents_raw (arg1) + offset, | |
c906108c | 1246 | TYPE_LENGTH (type)); |
df407dfe | 1247 | v->offset = (value_offset (arg1) + offset |
13c3b5f5 | 1248 | + value_embedded_offset (arg1)); |
c906108c SS |
1249 | } |
1250 | VALUE_LVAL (v) = VALUE_LVAL (arg1); | |
1251 | if (VALUE_LVAL (arg1) == lval_internalvar) | |
1252 | VALUE_LVAL (v) = lval_internalvar_component; | |
1253 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); | |
9ee8fc9d | 1254 | VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
0c16dd26 | 1255 | VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
c906108c | 1256 | /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset |
c5aa993b | 1257 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */ |
c906108c SS |
1258 | return v; |
1259 | } | |
1260 | ||
1261 | /* Given a value ARG1 of a struct or union type, | |
1262 | extract and return the value of one of its (non-static) fields. | |
1263 | FIELDNO says which field. */ | |
1264 | ||
f23631e4 | 1265 | struct value * |
aa1ee363 | 1266 | value_field (struct value *arg1, int fieldno) |
c906108c | 1267 | { |
df407dfe | 1268 | return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
c906108c SS |
1269 | } |
1270 | ||
1271 | /* Return a non-virtual function as a value. | |
1272 | F is the list of member functions which contains the desired method. | |
0478d61c FF |
1273 | J is an index into F which provides the desired method. |
1274 | ||
1275 | We only use the symbol for its address, so be happy with either a | |
1276 | full symbol or a minimal symbol. | |
1277 | */ | |
c906108c | 1278 | |
f23631e4 AC |
1279 | struct value * |
1280 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, | |
fba45db2 | 1281 | int offset) |
c906108c | 1282 | { |
f23631e4 | 1283 | struct value *v; |
52f0bd74 | 1284 | struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
0478d61c | 1285 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
c906108c | 1286 | struct symbol *sym; |
0478d61c | 1287 | struct minimal_symbol *msym; |
c906108c | 1288 | |
176620f1 | 1289 | sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0, NULL); |
5ae326fa | 1290 | if (sym != NULL) |
0478d61c | 1291 | { |
5ae326fa AC |
1292 | msym = NULL; |
1293 | } | |
1294 | else | |
1295 | { | |
1296 | gdb_assert (sym == NULL); | |
0478d61c | 1297 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
5ae326fa AC |
1298 | if (msym == NULL) |
1299 | return NULL; | |
0478d61c FF |
1300 | } |
1301 | ||
c906108c | 1302 | v = allocate_value (ftype); |
0478d61c FF |
1303 | if (sym) |
1304 | { | |
1305 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | |
1306 | } | |
1307 | else | |
1308 | { | |
1309 | VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym); | |
1310 | } | |
c906108c SS |
1311 | |
1312 | if (arg1p) | |
c5aa993b | 1313 | { |
df407dfe | 1314 | if (type != value_type (*arg1p)) |
c5aa993b JM |
1315 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
1316 | value_addr (*arg1p))); | |
1317 | ||
070ad9f0 | 1318 | /* Move the `this' pointer according to the offset. |
c5aa993b JM |
1319 | VALUE_OFFSET (*arg1p) += offset; |
1320 | */ | |
c906108c SS |
1321 | } |
1322 | ||
1323 | return v; | |
1324 | } | |
1325 | ||
c906108c SS |
1326 | \f |
1327 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at | |
1328 | VALADDR. | |
1329 | ||
1330 | Extracting bits depends on endianness of the machine. Compute the | |
1331 | number of least significant bits to discard. For big endian machines, | |
1332 | we compute the total number of bits in the anonymous object, subtract | |
1333 | off the bit count from the MSB of the object to the MSB of the | |
1334 | bitfield, then the size of the bitfield, which leaves the LSB discard | |
1335 | count. For little endian machines, the discard count is simply the | |
1336 | number of bits from the LSB of the anonymous object to the LSB of the | |
1337 | bitfield. | |
1338 | ||
1339 | If the field is signed, we also do sign extension. */ | |
1340 | ||
1341 | LONGEST | |
66140c26 | 1342 | unpack_field_as_long (struct type *type, const char *valaddr, int fieldno) |
c906108c SS |
1343 | { |
1344 | ULONGEST val; | |
1345 | ULONGEST valmask; | |
1346 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); | |
1347 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); | |
1348 | int lsbcount; | |
1349 | struct type *field_type; | |
1350 | ||
1351 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); | |
1352 | field_type = TYPE_FIELD_TYPE (type, fieldno); | |
1353 | CHECK_TYPEDEF (field_type); | |
1354 | ||
1355 | /* Extract bits. See comment above. */ | |
1356 | ||
1357 | if (BITS_BIG_ENDIAN) | |
1358 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); | |
1359 | else | |
1360 | lsbcount = (bitpos % 8); | |
1361 | val >>= lsbcount; | |
1362 | ||
1363 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. | |
1364 | If the field is signed, and is negative, then sign extend. */ | |
1365 | ||
1366 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) | |
1367 | { | |
1368 | valmask = (((ULONGEST) 1) << bitsize) - 1; | |
1369 | val &= valmask; | |
1370 | if (!TYPE_UNSIGNED (field_type)) | |
1371 | { | |
1372 | if (val & (valmask ^ (valmask >> 1))) | |
1373 | { | |
1374 | val |= ~valmask; | |
1375 | } | |
1376 | } | |
1377 | } | |
1378 | return (val); | |
1379 | } | |
1380 | ||
1381 | /* Modify the value of a bitfield. ADDR points to a block of memory in | |
1382 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL | |
1383 | is the desired value of the field, in host byte order. BITPOS and BITSIZE | |
f4e88c8e PH |
1384 | indicate which bits (in target bit order) comprise the bitfield. |
1385 | Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and | |
1386 | 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ | |
c906108c SS |
1387 | |
1388 | void | |
fba45db2 | 1389 | modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) |
c906108c | 1390 | { |
f4e88c8e PH |
1391 | ULONGEST oword; |
1392 | ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); | |
c906108c SS |
1393 | |
1394 | /* If a negative fieldval fits in the field in question, chop | |
1395 | off the sign extension bits. */ | |
f4e88c8e PH |
1396 | if ((~fieldval & ~(mask >> 1)) == 0) |
1397 | fieldval &= mask; | |
c906108c SS |
1398 | |
1399 | /* Warn if value is too big to fit in the field in question. */ | |
f4e88c8e | 1400 | if (0 != (fieldval & ~mask)) |
c906108c SS |
1401 | { |
1402 | /* FIXME: would like to include fieldval in the message, but | |
c5aa993b | 1403 | we don't have a sprintf_longest. */ |
8a3fe4f8 | 1404 | warning (_("Value does not fit in %d bits."), bitsize); |
c906108c SS |
1405 | |
1406 | /* Truncate it, otherwise adjoining fields may be corrupted. */ | |
f4e88c8e | 1407 | fieldval &= mask; |
c906108c SS |
1408 | } |
1409 | ||
f4e88c8e | 1410 | oword = extract_unsigned_integer (addr, sizeof oword); |
c906108c SS |
1411 | |
1412 | /* Shifting for bit field depends on endianness of the target machine. */ | |
1413 | if (BITS_BIG_ENDIAN) | |
1414 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; | |
1415 | ||
f4e88c8e | 1416 | oword &= ~(mask << bitpos); |
c906108c SS |
1417 | oword |= fieldval << bitpos; |
1418 | ||
f4e88c8e | 1419 | store_unsigned_integer (addr, sizeof oword, oword); |
c906108c SS |
1420 | } |
1421 | \f | |
1422 | /* Convert C numbers into newly allocated values */ | |
1423 | ||
f23631e4 | 1424 | struct value * |
aa1ee363 | 1425 | value_from_longest (struct type *type, LONGEST num) |
c906108c | 1426 | { |
f23631e4 | 1427 | struct value *val = allocate_value (type); |
52f0bd74 AC |
1428 | enum type_code code; |
1429 | int len; | |
c5aa993b | 1430 | retry: |
c906108c SS |
1431 | code = TYPE_CODE (type); |
1432 | len = TYPE_LENGTH (type); | |
1433 | ||
1434 | switch (code) | |
1435 | { | |
1436 | case TYPE_CODE_TYPEDEF: | |
1437 | type = check_typedef (type); | |
1438 | goto retry; | |
1439 | case TYPE_CODE_INT: | |
1440 | case TYPE_CODE_CHAR: | |
1441 | case TYPE_CODE_ENUM: | |
1442 | case TYPE_CODE_BOOL: | |
1443 | case TYPE_CODE_RANGE: | |
990a07ab | 1444 | store_signed_integer (value_contents_raw (val), len, num); |
c906108c | 1445 | break; |
c5aa993b | 1446 | |
c906108c SS |
1447 | case TYPE_CODE_REF: |
1448 | case TYPE_CODE_PTR: | |
990a07ab | 1449 | store_typed_address (value_contents_raw (val), type, (CORE_ADDR) num); |
c906108c | 1450 | break; |
c5aa993b | 1451 | |
c906108c | 1452 | default: |
8a3fe4f8 | 1453 | error (_("Unexpected type (%d) encountered for integer constant."), code); |
c906108c SS |
1454 | } |
1455 | return val; | |
1456 | } | |
1457 | ||
4478b372 JB |
1458 | |
1459 | /* Create a value representing a pointer of type TYPE to the address | |
1460 | ADDR. */ | |
f23631e4 | 1461 | struct value * |
4478b372 JB |
1462 | value_from_pointer (struct type *type, CORE_ADDR addr) |
1463 | { | |
f23631e4 | 1464 | struct value *val = allocate_value (type); |
990a07ab | 1465 | store_typed_address (value_contents_raw (val), type, addr); |
4478b372 JB |
1466 | return val; |
1467 | } | |
1468 | ||
1469 | ||
0f71a2f6 | 1470 | /* Create a value for a string constant to be stored locally |
070ad9f0 | 1471 | (not in the inferior's memory space, but in GDB memory). |
0f71a2f6 JM |
1472 | This is analogous to value_from_longest, which also does not |
1473 | use inferior memory. String shall NOT contain embedded nulls. */ | |
1474 | ||
f23631e4 | 1475 | struct value * |
fba45db2 | 1476 | value_from_string (char *ptr) |
0f71a2f6 | 1477 | { |
f23631e4 | 1478 | struct value *val; |
c5aa993b | 1479 | int len = strlen (ptr); |
0f71a2f6 | 1480 | int lowbound = current_language->string_lower_bound; |
f290d38e AC |
1481 | struct type *string_char_type; |
1482 | struct type *rangetype; | |
1483 | struct type *stringtype; | |
1484 | ||
1485 | rangetype = create_range_type ((struct type *) NULL, | |
1486 | builtin_type_int, | |
1487 | lowbound, len + lowbound - 1); | |
1488 | string_char_type = language_string_char_type (current_language, | |
1489 | current_gdbarch); | |
1490 | stringtype = create_array_type ((struct type *) NULL, | |
1491 | string_char_type, | |
1492 | rangetype); | |
0f71a2f6 | 1493 | val = allocate_value (stringtype); |
990a07ab | 1494 | memcpy (value_contents_raw (val), ptr, len); |
0f71a2f6 JM |
1495 | return val; |
1496 | } | |
1497 | ||
f23631e4 | 1498 | struct value * |
fba45db2 | 1499 | value_from_double (struct type *type, DOUBLEST num) |
c906108c | 1500 | { |
f23631e4 | 1501 | struct value *val = allocate_value (type); |
c906108c | 1502 | struct type *base_type = check_typedef (type); |
52f0bd74 AC |
1503 | enum type_code code = TYPE_CODE (base_type); |
1504 | int len = TYPE_LENGTH (base_type); | |
c906108c SS |
1505 | |
1506 | if (code == TYPE_CODE_FLT) | |
1507 | { | |
990a07ab | 1508 | store_typed_floating (value_contents_raw (val), base_type, num); |
c906108c SS |
1509 | } |
1510 | else | |
8a3fe4f8 | 1511 | error (_("Unexpected type encountered for floating constant.")); |
c906108c SS |
1512 | |
1513 | return val; | |
1514 | } | |
994b9211 AC |
1515 | |
1516 | struct value * | |
1517 | coerce_ref (struct value *arg) | |
1518 | { | |
df407dfe | 1519 | struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
994b9211 AC |
1520 | if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) |
1521 | arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), | |
df407dfe | 1522 | unpack_pointer (value_type (arg), |
0fd88904 | 1523 | value_contents (arg))); |
994b9211 AC |
1524 | return arg; |
1525 | } | |
1526 | ||
1527 | struct value * | |
1528 | coerce_array (struct value *arg) | |
1529 | { | |
1530 | arg = coerce_ref (arg); | |
1531 | if (current_language->c_style_arrays | |
df407dfe | 1532 | && TYPE_CODE (value_type (arg)) == TYPE_CODE_ARRAY) |
994b9211 | 1533 | arg = value_coerce_array (arg); |
df407dfe | 1534 | if (TYPE_CODE (value_type (arg)) == TYPE_CODE_FUNC) |
994b9211 AC |
1535 | arg = value_coerce_function (arg); |
1536 | return arg; | |
1537 | } | |
1538 | ||
1539 | struct value * | |
1540 | coerce_number (struct value *arg) | |
1541 | { | |
1542 | arg = coerce_array (arg); | |
1543 | arg = coerce_enum (arg); | |
1544 | return arg; | |
1545 | } | |
1546 | ||
1547 | struct value * | |
1548 | coerce_enum (struct value *arg) | |
1549 | { | |
df407dfe | 1550 | if (TYPE_CODE (check_typedef (value_type (arg))) == TYPE_CODE_ENUM) |
994b9211 AC |
1551 | arg = value_cast (builtin_type_unsigned_int, arg); |
1552 | return arg; | |
1553 | } | |
c906108c | 1554 | \f |
c906108c | 1555 | |
74055713 AC |
1556 | /* Should we use DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS instead of |
1557 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc and TYPE | |
1558 | is the type (which is known to be struct, union or array). | |
c906108c SS |
1559 | |
1560 | On most machines, the struct convention is used unless we are | |
1561 | using gcc and the type is of a special size. */ | |
1562 | /* As of about 31 Mar 93, GCC was changed to be compatible with the | |
1563 | native compiler. GCC 2.3.3 was the last release that did it the | |
1564 | old way. Since gcc2_compiled was not changed, we have no | |
1565 | way to correctly win in all cases, so we just do the right thing | |
1566 | for gcc1 and for gcc2 after this change. Thus it loses for gcc | |
1567 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled | |
1568 | would cause more chaos than dealing with some struct returns being | |
1569 | handled wrong. */ | |
bc87dfa0 AC |
1570 | /* NOTE: cagney/2004-06-13: Deleted check for "gcc_p". GCC 1.x is |
1571 | dead. */ | |
c906108c SS |
1572 | |
1573 | int | |
fba45db2 | 1574 | generic_use_struct_convention (int gcc_p, struct type *value_type) |
c5aa993b | 1575 | { |
bc87dfa0 AC |
1576 | return !(TYPE_LENGTH (value_type) == 1 |
1577 | || TYPE_LENGTH (value_type) == 2 | |
1578 | || TYPE_LENGTH (value_type) == 4 | |
1579 | || TYPE_LENGTH (value_type) == 8); | |
c906108c SS |
1580 | } |
1581 | ||
48436ce6 AC |
1582 | /* Return true if the function returning the specified type is using |
1583 | the convention of returning structures in memory (passing in the | |
1584 | address as a hidden first parameter). GCC_P is nonzero if compiled | |
c906108c SS |
1585 | with GCC. */ |
1586 | ||
1587 | int | |
48436ce6 | 1588 | using_struct_return (struct type *value_type, int gcc_p) |
c906108c | 1589 | { |
52f0bd74 | 1590 | enum type_code code = TYPE_CODE (value_type); |
c906108c SS |
1591 | |
1592 | if (code == TYPE_CODE_ERROR) | |
8a3fe4f8 | 1593 | error (_("Function return type unknown.")); |
c906108c | 1594 | |
667e784f AC |
1595 | if (code == TYPE_CODE_VOID) |
1596 | /* A void return value is never in memory. See also corresponding | |
44e5158b | 1597 | code in "print_return_value". */ |
667e784f AC |
1598 | return 0; |
1599 | ||
92ad9cd9 AC |
1600 | /* Probe the architecture for the return-value convention. */ |
1601 | return (gdbarch_return_value (current_gdbarch, value_type, | |
1602 | NULL, NULL, NULL) | |
31db7b6c | 1603 | != RETURN_VALUE_REGISTER_CONVENTION); |
c906108c SS |
1604 | } |
1605 | ||
c906108c | 1606 | void |
fba45db2 | 1607 | _initialize_values (void) |
c906108c SS |
1608 | { |
1609 | add_cmd ("convenience", no_class, show_convenience, | |
c5aa993b | 1610 | "Debugger convenience (\"$foo\") variables.\n\ |
c906108c SS |
1611 | These variables are created when you assign them values;\n\ |
1612 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ | |
1613 | A few convenience variables are given values automatically:\n\ | |
1614 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ | |
1615 | \"$__\" holds the contents of the last address examined with \"x\".", | |
1616 | &showlist); | |
1617 | ||
1618 | add_cmd ("values", no_class, show_values, | |
1619 | "Elements of value history around item number IDX (or last ten).", | |
1620 | &showlist); | |
1621 | } |