| 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
| 2 | |
| 3 | Copyright (C) 1986-2000, 2002-2012 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "arch-utils.h" |
| 22 | #include "gdb_string.h" |
| 23 | #include "symtab.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "value.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "command.h" |
| 28 | #include "gdbcmd.h" |
| 29 | #include "target.h" |
| 30 | #include "language.h" |
| 31 | #include "demangle.h" |
| 32 | #include "doublest.h" |
| 33 | #include "gdb_assert.h" |
| 34 | #include "regcache.h" |
| 35 | #include "block.h" |
| 36 | #include "dfp.h" |
| 37 | #include "objfiles.h" |
| 38 | #include "valprint.h" |
| 39 | #include "cli/cli-decode.h" |
| 40 | #include "exceptions.h" |
| 41 | #include "python/python.h" |
| 42 | #include <ctype.h> |
| 43 | #include "tracepoint.h" |
| 44 | #include "cp-abi.h" |
| 45 | |
| 46 | /* Prototypes for exported functions. */ |
| 47 | |
| 48 | void _initialize_values (void); |
| 49 | |
| 50 | /* Definition of a user function. */ |
| 51 | struct internal_function |
| 52 | { |
| 53 | /* The name of the function. It is a bit odd to have this in the |
| 54 | function itself -- the user might use a differently-named |
| 55 | convenience variable to hold the function. */ |
| 56 | char *name; |
| 57 | |
| 58 | /* The handler. */ |
| 59 | internal_function_fn handler; |
| 60 | |
| 61 | /* User data for the handler. */ |
| 62 | void *cookie; |
| 63 | }; |
| 64 | |
| 65 | /* Defines an [OFFSET, OFFSET + LENGTH) range. */ |
| 66 | |
| 67 | struct range |
| 68 | { |
| 69 | /* Lowest offset in the range. */ |
| 70 | int offset; |
| 71 | |
| 72 | /* Length of the range. */ |
| 73 | int length; |
| 74 | }; |
| 75 | |
| 76 | typedef struct range range_s; |
| 77 | |
| 78 | DEF_VEC_O(range_s); |
| 79 | |
| 80 | /* Returns true if the ranges defined by [offset1, offset1+len1) and |
| 81 | [offset2, offset2+len2) overlap. */ |
| 82 | |
| 83 | static int |
| 84 | ranges_overlap (int offset1, int len1, |
| 85 | int offset2, int len2) |
| 86 | { |
| 87 | ULONGEST h, l; |
| 88 | |
| 89 | l = max (offset1, offset2); |
| 90 | h = min (offset1 + len1, offset2 + len2); |
| 91 | return (l < h); |
| 92 | } |
| 93 | |
| 94 | /* Returns true if the first argument is strictly less than the |
| 95 | second, useful for VEC_lower_bound. We keep ranges sorted by |
| 96 | offset and coalesce overlapping and contiguous ranges, so this just |
| 97 | compares the starting offset. */ |
| 98 | |
| 99 | static int |
| 100 | range_lessthan (const range_s *r1, const range_s *r2) |
| 101 | { |
| 102 | return r1->offset < r2->offset; |
| 103 | } |
| 104 | |
| 105 | /* Returns true if RANGES contains any range that overlaps [OFFSET, |
| 106 | OFFSET+LENGTH). */ |
| 107 | |
| 108 | static int |
| 109 | ranges_contain (VEC(range_s) *ranges, int offset, int length) |
| 110 | { |
| 111 | range_s what; |
| 112 | int i; |
| 113 | |
| 114 | what.offset = offset; |
| 115 | what.length = length; |
| 116 | |
| 117 | /* We keep ranges sorted by offset and coalesce overlapping and |
| 118 | contiguous ranges, so to check if a range list contains a given |
| 119 | range, we can do a binary search for the position the given range |
| 120 | would be inserted if we only considered the starting OFFSET of |
| 121 | ranges. We call that position I. Since we also have LENGTH to |
| 122 | care for (this is a range afterall), we need to check if the |
| 123 | _previous_ range overlaps the I range. E.g., |
| 124 | |
| 125 | R |
| 126 | |---| |
| 127 | |---| |---| |------| ... |--| |
| 128 | 0 1 2 N |
| 129 | |
| 130 | I=1 |
| 131 | |
| 132 | In the case above, the binary search would return `I=1', meaning, |
| 133 | this OFFSET should be inserted at position 1, and the current |
| 134 | position 1 should be pushed further (and before 2). But, `0' |
| 135 | overlaps with R. |
| 136 | |
| 137 | Then we need to check if the I range overlaps the I range itself. |
| 138 | E.g., |
| 139 | |
| 140 | R |
| 141 | |---| |
| 142 | |---| |---| |-------| ... |--| |
| 143 | 0 1 2 N |
| 144 | |
| 145 | I=1 |
| 146 | */ |
| 147 | |
| 148 | i = VEC_lower_bound (range_s, ranges, &what, range_lessthan); |
| 149 | |
| 150 | if (i > 0) |
| 151 | { |
| 152 | struct range *bef = VEC_index (range_s, ranges, i - 1); |
| 153 | |
| 154 | if (ranges_overlap (bef->offset, bef->length, offset, length)) |
| 155 | return 1; |
| 156 | } |
| 157 | |
| 158 | if (i < VEC_length (range_s, ranges)) |
| 159 | { |
| 160 | struct range *r = VEC_index (range_s, ranges, i); |
| 161 | |
| 162 | if (ranges_overlap (r->offset, r->length, offset, length)) |
| 163 | return 1; |
| 164 | } |
| 165 | |
| 166 | return 0; |
| 167 | } |
| 168 | |
| 169 | static struct cmd_list_element *functionlist; |
| 170 | |
| 171 | /* Note that the fields in this structure are arranged to save a bit |
| 172 | of memory. */ |
| 173 | |
| 174 | struct value |
| 175 | { |
| 176 | /* Type of value; either not an lval, or one of the various |
| 177 | different possible kinds of lval. */ |
| 178 | enum lval_type lval; |
| 179 | |
| 180 | /* Is it modifiable? Only relevant if lval != not_lval. */ |
| 181 | unsigned int modifiable : 1; |
| 182 | |
| 183 | /* If zero, contents of this value are in the contents field. If |
| 184 | nonzero, contents are in inferior. If the lval field is lval_memory, |
| 185 | the contents are in inferior memory at location.address plus offset. |
| 186 | The lval field may also be lval_register. |
| 187 | |
| 188 | WARNING: This field is used by the code which handles watchpoints |
| 189 | (see breakpoint.c) to decide whether a particular value can be |
| 190 | watched by hardware watchpoints. If the lazy flag is set for |
| 191 | some member of a value chain, it is assumed that this member of |
| 192 | the chain doesn't need to be watched as part of watching the |
| 193 | value itself. This is how GDB avoids watching the entire struct |
| 194 | or array when the user wants to watch a single struct member or |
| 195 | array element. If you ever change the way lazy flag is set and |
| 196 | reset, be sure to consider this use as well! */ |
| 197 | unsigned int lazy : 1; |
| 198 | |
| 199 | /* If nonzero, this is the value of a variable which does not |
| 200 | actually exist in the program. */ |
| 201 | unsigned int optimized_out : 1; |
| 202 | |
| 203 | /* If value is a variable, is it initialized or not. */ |
| 204 | unsigned int initialized : 1; |
| 205 | |
| 206 | /* If value is from the stack. If this is set, read_stack will be |
| 207 | used instead of read_memory to enable extra caching. */ |
| 208 | unsigned int stack : 1; |
| 209 | |
| 210 | /* If the value has been released. */ |
| 211 | unsigned int released : 1; |
| 212 | |
| 213 | /* Location of value (if lval). */ |
| 214 | union |
| 215 | { |
| 216 | /* If lval == lval_memory, this is the address in the inferior. |
| 217 | If lval == lval_register, this is the byte offset into the |
| 218 | registers structure. */ |
| 219 | CORE_ADDR address; |
| 220 | |
| 221 | /* Pointer to internal variable. */ |
| 222 | struct internalvar *internalvar; |
| 223 | |
| 224 | /* If lval == lval_computed, this is a set of function pointers |
| 225 | to use to access and describe the value, and a closure pointer |
| 226 | for them to use. */ |
| 227 | struct |
| 228 | { |
| 229 | /* Functions to call. */ |
| 230 | const struct lval_funcs *funcs; |
| 231 | |
| 232 | /* Closure for those functions to use. */ |
| 233 | void *closure; |
| 234 | } computed; |
| 235 | } location; |
| 236 | |
| 237 | /* Describes offset of a value within lval of a structure in bytes. |
| 238 | If lval == lval_memory, this is an offset to the address. If |
| 239 | lval == lval_register, this is a further offset from |
| 240 | location.address within the registers structure. Note also the |
| 241 | member embedded_offset below. */ |
| 242 | int offset; |
| 243 | |
| 244 | /* Only used for bitfields; number of bits contained in them. */ |
| 245 | int bitsize; |
| 246 | |
| 247 | /* Only used for bitfields; position of start of field. For |
| 248 | gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For |
| 249 | gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */ |
| 250 | int bitpos; |
| 251 | |
| 252 | /* The number of references to this value. When a value is created, |
| 253 | the value chain holds a reference, so REFERENCE_COUNT is 1. If |
| 254 | release_value is called, this value is removed from the chain but |
| 255 | the caller of release_value now has a reference to this value. |
| 256 | The caller must arrange for a call to value_free later. */ |
| 257 | int reference_count; |
| 258 | |
| 259 | /* Only used for bitfields; the containing value. This allows a |
| 260 | single read from the target when displaying multiple |
| 261 | bitfields. */ |
| 262 | struct value *parent; |
| 263 | |
| 264 | /* Frame register value is relative to. This will be described in |
| 265 | the lval enum above as "lval_register". */ |
| 266 | struct frame_id frame_id; |
| 267 | |
| 268 | /* Type of the value. */ |
| 269 | struct type *type; |
| 270 | |
| 271 | /* If a value represents a C++ object, then the `type' field gives |
| 272 | the object's compile-time type. If the object actually belongs |
| 273 | to some class derived from `type', perhaps with other base |
| 274 | classes and additional members, then `type' is just a subobject |
| 275 | of the real thing, and the full object is probably larger than |
| 276 | `type' would suggest. |
| 277 | |
| 278 | If `type' is a dynamic class (i.e. one with a vtable), then GDB |
| 279 | can actually determine the object's run-time type by looking at |
| 280 | the run-time type information in the vtable. When this |
| 281 | information is available, we may elect to read in the entire |
| 282 | object, for several reasons: |
| 283 | |
| 284 | - When printing the value, the user would probably rather see the |
| 285 | full object, not just the limited portion apparent from the |
| 286 | compile-time type. |
| 287 | |
| 288 | - If `type' has virtual base classes, then even printing `type' |
| 289 | alone may require reaching outside the `type' portion of the |
| 290 | object to wherever the virtual base class has been stored. |
| 291 | |
| 292 | When we store the entire object, `enclosing_type' is the run-time |
| 293 | type -- the complete object -- and `embedded_offset' is the |
| 294 | offset of `type' within that larger type, in bytes. The |
| 295 | value_contents() macro takes `embedded_offset' into account, so |
| 296 | most GDB code continues to see the `type' portion of the value, |
| 297 | just as the inferior would. |
| 298 | |
| 299 | If `type' is a pointer to an object, then `enclosing_type' is a |
| 300 | pointer to the object's run-time type, and `pointed_to_offset' is |
| 301 | the offset in bytes from the full object to the pointed-to object |
| 302 | -- that is, the value `embedded_offset' would have if we followed |
| 303 | the pointer and fetched the complete object. (I don't really see |
| 304 | the point. Why not just determine the run-time type when you |
| 305 | indirect, and avoid the special case? The contents don't matter |
| 306 | until you indirect anyway.) |
| 307 | |
| 308 | If we're not doing anything fancy, `enclosing_type' is equal to |
| 309 | `type', and `embedded_offset' is zero, so everything works |
| 310 | normally. */ |
| 311 | struct type *enclosing_type; |
| 312 | int embedded_offset; |
| 313 | int pointed_to_offset; |
| 314 | |
| 315 | /* Values are stored in a chain, so that they can be deleted easily |
| 316 | over calls to the inferior. Values assigned to internal |
| 317 | variables, put into the value history or exposed to Python are |
| 318 | taken off this list. */ |
| 319 | struct value *next; |
| 320 | |
| 321 | /* Register number if the value is from a register. */ |
| 322 | short regnum; |
| 323 | |
| 324 | /* Actual contents of the value. Target byte-order. NULL or not |
| 325 | valid if lazy is nonzero. */ |
| 326 | gdb_byte *contents; |
| 327 | |
| 328 | /* Unavailable ranges in CONTENTS. We mark unavailable ranges, |
| 329 | rather than available, since the common and default case is for a |
| 330 | value to be available. This is filled in at value read time. */ |
| 331 | VEC(range_s) *unavailable; |
| 332 | }; |
| 333 | |
| 334 | int |
| 335 | value_bytes_available (const struct value *value, int offset, int length) |
| 336 | { |
| 337 | gdb_assert (!value->lazy); |
| 338 | |
| 339 | return !ranges_contain (value->unavailable, offset, length); |
| 340 | } |
| 341 | |
| 342 | int |
| 343 | value_entirely_available (struct value *value) |
| 344 | { |
| 345 | /* We can only tell whether the whole value is available when we try |
| 346 | to read it. */ |
| 347 | if (value->lazy) |
| 348 | value_fetch_lazy (value); |
| 349 | |
| 350 | if (VEC_empty (range_s, value->unavailable)) |
| 351 | return 1; |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | void |
| 356 | mark_value_bytes_unavailable (struct value *value, int offset, int length) |
| 357 | { |
| 358 | range_s newr; |
| 359 | int i; |
| 360 | |
| 361 | /* Insert the range sorted. If there's overlap or the new range |
| 362 | would be contiguous with an existing range, merge. */ |
| 363 | |
| 364 | newr.offset = offset; |
| 365 | newr.length = length; |
| 366 | |
| 367 | /* Do a binary search for the position the given range would be |
| 368 | inserted if we only considered the starting OFFSET of ranges. |
| 369 | Call that position I. Since we also have LENGTH to care for |
| 370 | (this is a range afterall), we need to check if the _previous_ |
| 371 | range overlaps the I range. E.g., calling R the new range: |
| 372 | |
| 373 | #1 - overlaps with previous |
| 374 | |
| 375 | R |
| 376 | |-...-| |
| 377 | |---| |---| |------| ... |--| |
| 378 | 0 1 2 N |
| 379 | |
| 380 | I=1 |
| 381 | |
| 382 | In the case #1 above, the binary search would return `I=1', |
| 383 | meaning, this OFFSET should be inserted at position 1, and the |
| 384 | current position 1 should be pushed further (and become 2). But, |
| 385 | note that `0' overlaps with R, so we want to merge them. |
| 386 | |
| 387 | A similar consideration needs to be taken if the new range would |
| 388 | be contiguous with the previous range: |
| 389 | |
| 390 | #2 - contiguous with previous |
| 391 | |
| 392 | R |
| 393 | |-...-| |
| 394 | |--| |---| |------| ... |--| |
| 395 | 0 1 2 N |
| 396 | |
| 397 | I=1 |
| 398 | |
| 399 | If there's no overlap with the previous range, as in: |
| 400 | |
| 401 | #3 - not overlapping and not contiguous |
| 402 | |
| 403 | R |
| 404 | |-...-| |
| 405 | |--| |---| |------| ... |--| |
| 406 | 0 1 2 N |
| 407 | |
| 408 | I=1 |
| 409 | |
| 410 | or if I is 0: |
| 411 | |
| 412 | #4 - R is the range with lowest offset |
| 413 | |
| 414 | R |
| 415 | |-...-| |
| 416 | |--| |---| |------| ... |--| |
| 417 | 0 1 2 N |
| 418 | |
| 419 | I=0 |
| 420 | |
| 421 | ... we just push the new range to I. |
| 422 | |
| 423 | All the 4 cases above need to consider that the new range may |
| 424 | also overlap several of the ranges that follow, or that R may be |
| 425 | contiguous with the following range, and merge. E.g., |
| 426 | |
| 427 | #5 - overlapping following ranges |
| 428 | |
| 429 | R |
| 430 | |------------------------| |
| 431 | |--| |---| |------| ... |--| |
| 432 | 0 1 2 N |
| 433 | |
| 434 | I=0 |
| 435 | |
| 436 | or: |
| 437 | |
| 438 | R |
| 439 | |-------| |
| 440 | |--| |---| |------| ... |--| |
| 441 | 0 1 2 N |
| 442 | |
| 443 | I=1 |
| 444 | |
| 445 | */ |
| 446 | |
| 447 | i = VEC_lower_bound (range_s, value->unavailable, &newr, range_lessthan); |
| 448 | if (i > 0) |
| 449 | { |
| 450 | struct range *bef = VEC_index (range_s, value->unavailable, i - 1); |
| 451 | |
| 452 | if (ranges_overlap (bef->offset, bef->length, offset, length)) |
| 453 | { |
| 454 | /* #1 */ |
| 455 | ULONGEST l = min (bef->offset, offset); |
| 456 | ULONGEST h = max (bef->offset + bef->length, offset + length); |
| 457 | |
| 458 | bef->offset = l; |
| 459 | bef->length = h - l; |
| 460 | i--; |
| 461 | } |
| 462 | else if (offset == bef->offset + bef->length) |
| 463 | { |
| 464 | /* #2 */ |
| 465 | bef->length += length; |
| 466 | i--; |
| 467 | } |
| 468 | else |
| 469 | { |
| 470 | /* #3 */ |
| 471 | VEC_safe_insert (range_s, value->unavailable, i, &newr); |
| 472 | } |
| 473 | } |
| 474 | else |
| 475 | { |
| 476 | /* #4 */ |
| 477 | VEC_safe_insert (range_s, value->unavailable, i, &newr); |
| 478 | } |
| 479 | |
| 480 | /* Check whether the ranges following the one we've just added or |
| 481 | touched can be folded in (#5 above). */ |
| 482 | if (i + 1 < VEC_length (range_s, value->unavailable)) |
| 483 | { |
| 484 | struct range *t; |
| 485 | struct range *r; |
| 486 | int removed = 0; |
| 487 | int next = i + 1; |
| 488 | |
| 489 | /* Get the range we just touched. */ |
| 490 | t = VEC_index (range_s, value->unavailable, i); |
| 491 | removed = 0; |
| 492 | |
| 493 | i = next; |
| 494 | for (; VEC_iterate (range_s, value->unavailable, i, r); i++) |
| 495 | if (r->offset <= t->offset + t->length) |
| 496 | { |
| 497 | ULONGEST l, h; |
| 498 | |
| 499 | l = min (t->offset, r->offset); |
| 500 | h = max (t->offset + t->length, r->offset + r->length); |
| 501 | |
| 502 | t->offset = l; |
| 503 | t->length = h - l; |
| 504 | |
| 505 | removed++; |
| 506 | } |
| 507 | else |
| 508 | { |
| 509 | /* If we couldn't merge this one, we won't be able to |
| 510 | merge following ones either, since the ranges are |
| 511 | always sorted by OFFSET. */ |
| 512 | break; |
| 513 | } |
| 514 | |
| 515 | if (removed != 0) |
| 516 | VEC_block_remove (range_s, value->unavailable, next, removed); |
| 517 | } |
| 518 | } |
| 519 | |
| 520 | /* Find the first range in RANGES that overlaps the range defined by |
| 521 | OFFSET and LENGTH, starting at element POS in the RANGES vector, |
| 522 | Returns the index into RANGES where such overlapping range was |
| 523 | found, or -1 if none was found. */ |
| 524 | |
| 525 | static int |
| 526 | find_first_range_overlap (VEC(range_s) *ranges, int pos, |
| 527 | int offset, int length) |
| 528 | { |
| 529 | range_s *r; |
| 530 | int i; |
| 531 | |
| 532 | for (i = pos; VEC_iterate (range_s, ranges, i, r); i++) |
| 533 | if (ranges_overlap (r->offset, r->length, offset, length)) |
| 534 | return i; |
| 535 | |
| 536 | return -1; |
| 537 | } |
| 538 | |
| 539 | int |
| 540 | value_available_contents_eq (const struct value *val1, int offset1, |
| 541 | const struct value *val2, int offset2, |
| 542 | int length) |
| 543 | { |
| 544 | int idx1 = 0, idx2 = 0; |
| 545 | |
| 546 | /* This routine is used by printing routines, where we should |
| 547 | already have read the value. Note that we only know whether a |
| 548 | value chunk is available if we've tried to read it. */ |
| 549 | gdb_assert (!val1->lazy && !val2->lazy); |
| 550 | |
| 551 | while (length > 0) |
| 552 | { |
| 553 | range_s *r1, *r2; |
| 554 | ULONGEST l1, h1; |
| 555 | ULONGEST l2, h2; |
| 556 | |
| 557 | idx1 = find_first_range_overlap (val1->unavailable, idx1, |
| 558 | offset1, length); |
| 559 | idx2 = find_first_range_overlap (val2->unavailable, idx2, |
| 560 | offset2, length); |
| 561 | |
| 562 | /* The usual case is for both values to be completely available. */ |
| 563 | if (idx1 == -1 && idx2 == -1) |
| 564 | return (memcmp (val1->contents + offset1, |
| 565 | val2->contents + offset2, |
| 566 | length) == 0); |
| 567 | /* The contents only match equal if the available set matches as |
| 568 | well. */ |
| 569 | else if (idx1 == -1 || idx2 == -1) |
| 570 | return 0; |
| 571 | |
| 572 | gdb_assert (idx1 != -1 && idx2 != -1); |
| 573 | |
| 574 | r1 = VEC_index (range_s, val1->unavailable, idx1); |
| 575 | r2 = VEC_index (range_s, val2->unavailable, idx2); |
| 576 | |
| 577 | /* Get the unavailable windows intersected by the incoming |
| 578 | ranges. The first and last ranges that overlap the argument |
| 579 | range may be wider than said incoming arguments ranges. */ |
| 580 | l1 = max (offset1, r1->offset); |
| 581 | h1 = min (offset1 + length, r1->offset + r1->length); |
| 582 | |
| 583 | l2 = max (offset2, r2->offset); |
| 584 | h2 = min (offset2 + length, r2->offset + r2->length); |
| 585 | |
| 586 | /* Make them relative to the respective start offsets, so we can |
| 587 | compare them for equality. */ |
| 588 | l1 -= offset1; |
| 589 | h1 -= offset1; |
| 590 | |
| 591 | l2 -= offset2; |
| 592 | h2 -= offset2; |
| 593 | |
| 594 | /* Different availability, no match. */ |
| 595 | if (l1 != l2 || h1 != h2) |
| 596 | return 0; |
| 597 | |
| 598 | /* Compare the _available_ contents. */ |
| 599 | if (memcmp (val1->contents + offset1, |
| 600 | val2->contents + offset2, |
| 601 | l1) != 0) |
| 602 | return 0; |
| 603 | |
| 604 | length -= h1; |
| 605 | offset1 += h1; |
| 606 | offset2 += h1; |
| 607 | } |
| 608 | |
| 609 | return 1; |
| 610 | } |
| 611 | |
| 612 | /* Prototypes for local functions. */ |
| 613 | |
| 614 | static void show_values (char *, int); |
| 615 | |
| 616 | static void show_convenience (char *, int); |
| 617 | |
| 618 | |
| 619 | /* The value-history records all the values printed |
| 620 | by print commands during this session. Each chunk |
| 621 | records 60 consecutive values. The first chunk on |
| 622 | the chain records the most recent values. |
| 623 | The total number of values is in value_history_count. */ |
| 624 | |
| 625 | #define VALUE_HISTORY_CHUNK 60 |
| 626 | |
| 627 | struct value_history_chunk |
| 628 | { |
| 629 | struct value_history_chunk *next; |
| 630 | struct value *values[VALUE_HISTORY_CHUNK]; |
| 631 | }; |
| 632 | |
| 633 | /* Chain of chunks now in use. */ |
| 634 | |
| 635 | static struct value_history_chunk *value_history_chain; |
| 636 | |
| 637 | static int value_history_count; /* Abs number of last entry stored. */ |
| 638 | |
| 639 | \f |
| 640 | /* List of all value objects currently allocated |
| 641 | (except for those released by calls to release_value) |
| 642 | This is so they can be freed after each command. */ |
| 643 | |
| 644 | static struct value *all_values; |
| 645 | |
| 646 | /* Allocate a lazy value for type TYPE. Its actual content is |
| 647 | "lazily" allocated too: the content field of the return value is |
| 648 | NULL; it will be allocated when it is fetched from the target. */ |
| 649 | |
| 650 | struct value * |
| 651 | allocate_value_lazy (struct type *type) |
| 652 | { |
| 653 | struct value *val; |
| 654 | |
| 655 | /* Call check_typedef on our type to make sure that, if TYPE |
| 656 | is a TYPE_CODE_TYPEDEF, its length is set to the length |
| 657 | of the target type instead of zero. However, we do not |
| 658 | replace the typedef type by the target type, because we want |
| 659 | to keep the typedef in order to be able to set the VAL's type |
| 660 | description correctly. */ |
| 661 | check_typedef (type); |
| 662 | |
| 663 | val = (struct value *) xzalloc (sizeof (struct value)); |
| 664 | val->contents = NULL; |
| 665 | val->next = all_values; |
| 666 | all_values = val; |
| 667 | val->type = type; |
| 668 | val->enclosing_type = type; |
| 669 | VALUE_LVAL (val) = not_lval; |
| 670 | val->location.address = 0; |
| 671 | VALUE_FRAME_ID (val) = null_frame_id; |
| 672 | val->offset = 0; |
| 673 | val->bitpos = 0; |
| 674 | val->bitsize = 0; |
| 675 | VALUE_REGNUM (val) = -1; |
| 676 | val->lazy = 1; |
| 677 | val->optimized_out = 0; |
| 678 | val->embedded_offset = 0; |
| 679 | val->pointed_to_offset = 0; |
| 680 | val->modifiable = 1; |
| 681 | val->initialized = 1; /* Default to initialized. */ |
| 682 | |
| 683 | /* Values start out on the all_values chain. */ |
| 684 | val->reference_count = 1; |
| 685 | |
| 686 | return val; |
| 687 | } |
| 688 | |
| 689 | /* Allocate the contents of VAL if it has not been allocated yet. */ |
| 690 | |
| 691 | void |
| 692 | allocate_value_contents (struct value *val) |
| 693 | { |
| 694 | if (!val->contents) |
| 695 | val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type)); |
| 696 | } |
| 697 | |
| 698 | /* Allocate a value and its contents for type TYPE. */ |
| 699 | |
| 700 | struct value * |
| 701 | allocate_value (struct type *type) |
| 702 | { |
| 703 | struct value *val = allocate_value_lazy (type); |
| 704 | |
| 705 | allocate_value_contents (val); |
| 706 | val->lazy = 0; |
| 707 | return val; |
| 708 | } |
| 709 | |
| 710 | /* Allocate a value that has the correct length |
| 711 | for COUNT repetitions of type TYPE. */ |
| 712 | |
| 713 | struct value * |
| 714 | allocate_repeat_value (struct type *type, int count) |
| 715 | { |
| 716 | int low_bound = current_language->string_lower_bound; /* ??? */ |
| 717 | /* FIXME-type-allocation: need a way to free this type when we are |
| 718 | done with it. */ |
| 719 | struct type *array_type |
| 720 | = lookup_array_range_type (type, low_bound, count + low_bound - 1); |
| 721 | |
| 722 | return allocate_value (array_type); |
| 723 | } |
| 724 | |
| 725 | struct value * |
| 726 | allocate_computed_value (struct type *type, |
| 727 | const struct lval_funcs *funcs, |
| 728 | void *closure) |
| 729 | { |
| 730 | struct value *v = allocate_value_lazy (type); |
| 731 | |
| 732 | VALUE_LVAL (v) = lval_computed; |
| 733 | v->location.computed.funcs = funcs; |
| 734 | v->location.computed.closure = closure; |
| 735 | |
| 736 | return v; |
| 737 | } |
| 738 | |
| 739 | /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */ |
| 740 | |
| 741 | struct value * |
| 742 | allocate_optimized_out_value (struct type *type) |
| 743 | { |
| 744 | struct value *retval = allocate_value_lazy (type); |
| 745 | |
| 746 | set_value_optimized_out (retval, 1); |
| 747 | |
| 748 | return retval; |
| 749 | } |
| 750 | |
| 751 | /* Accessor methods. */ |
| 752 | |
| 753 | struct value * |
| 754 | value_next (struct value *value) |
| 755 | { |
| 756 | return value->next; |
| 757 | } |
| 758 | |
| 759 | struct type * |
| 760 | value_type (const struct value *value) |
| 761 | { |
| 762 | return value->type; |
| 763 | } |
| 764 | void |
| 765 | deprecated_set_value_type (struct value *value, struct type *type) |
| 766 | { |
| 767 | value->type = type; |
| 768 | } |
| 769 | |
| 770 | int |
| 771 | value_offset (const struct value *value) |
| 772 | { |
| 773 | return value->offset; |
| 774 | } |
| 775 | void |
| 776 | set_value_offset (struct value *value, int offset) |
| 777 | { |
| 778 | value->offset = offset; |
| 779 | } |
| 780 | |
| 781 | int |
| 782 | value_bitpos (const struct value *value) |
| 783 | { |
| 784 | return value->bitpos; |
| 785 | } |
| 786 | void |
| 787 | set_value_bitpos (struct value *value, int bit) |
| 788 | { |
| 789 | value->bitpos = bit; |
| 790 | } |
| 791 | |
| 792 | int |
| 793 | value_bitsize (const struct value *value) |
| 794 | { |
| 795 | return value->bitsize; |
| 796 | } |
| 797 | void |
| 798 | set_value_bitsize (struct value *value, int bit) |
| 799 | { |
| 800 | value->bitsize = bit; |
| 801 | } |
| 802 | |
| 803 | struct value * |
| 804 | value_parent (struct value *value) |
| 805 | { |
| 806 | return value->parent; |
| 807 | } |
| 808 | |
| 809 | /* See value.h. */ |
| 810 | |
| 811 | void |
| 812 | set_value_parent (struct value *value, struct value *parent) |
| 813 | { |
| 814 | value->parent = parent; |
| 815 | } |
| 816 | |
| 817 | gdb_byte * |
| 818 | value_contents_raw (struct value *value) |
| 819 | { |
| 820 | allocate_value_contents (value); |
| 821 | return value->contents + value->embedded_offset; |
| 822 | } |
| 823 | |
| 824 | gdb_byte * |
| 825 | value_contents_all_raw (struct value *value) |
| 826 | { |
| 827 | allocate_value_contents (value); |
| 828 | return value->contents; |
| 829 | } |
| 830 | |
| 831 | struct type * |
| 832 | value_enclosing_type (struct value *value) |
| 833 | { |
| 834 | return value->enclosing_type; |
| 835 | } |
| 836 | |
| 837 | /* Look at value.h for description. */ |
| 838 | |
| 839 | struct type * |
| 840 | value_actual_type (struct value *value, int resolve_simple_types, |
| 841 | int *real_type_found) |
| 842 | { |
| 843 | struct value_print_options opts; |
| 844 | struct type *result; |
| 845 | |
| 846 | get_user_print_options (&opts); |
| 847 | |
| 848 | if (real_type_found) |
| 849 | *real_type_found = 0; |
| 850 | result = value_type (value); |
| 851 | if (opts.objectprint) |
| 852 | { |
| 853 | if (TYPE_CODE (result) == TYPE_CODE_PTR |
| 854 | || TYPE_CODE (result) == TYPE_CODE_REF) |
| 855 | { |
| 856 | struct type *real_type; |
| 857 | |
| 858 | real_type = value_rtti_indirect_type (value, NULL, NULL, NULL); |
| 859 | if (real_type) |
| 860 | { |
| 861 | if (real_type_found) |
| 862 | *real_type_found = 1; |
| 863 | result = real_type; |
| 864 | } |
| 865 | } |
| 866 | else if (resolve_simple_types) |
| 867 | { |
| 868 | if (real_type_found) |
| 869 | *real_type_found = 1; |
| 870 | result = value_enclosing_type (value); |
| 871 | } |
| 872 | } |
| 873 | |
| 874 | return result; |
| 875 | } |
| 876 | |
| 877 | static void |
| 878 | require_not_optimized_out (const struct value *value) |
| 879 | { |
| 880 | if (value->optimized_out) |
| 881 | error (_("value has been optimized out")); |
| 882 | } |
| 883 | |
| 884 | static void |
| 885 | require_available (const struct value *value) |
| 886 | { |
| 887 | if (!VEC_empty (range_s, value->unavailable)) |
| 888 | throw_error (NOT_AVAILABLE_ERROR, _("value is not available")); |
| 889 | } |
| 890 | |
| 891 | const gdb_byte * |
| 892 | value_contents_for_printing (struct value *value) |
| 893 | { |
| 894 | if (value->lazy) |
| 895 | value_fetch_lazy (value); |
| 896 | return value->contents; |
| 897 | } |
| 898 | |
| 899 | const gdb_byte * |
| 900 | value_contents_for_printing_const (const struct value *value) |
| 901 | { |
| 902 | gdb_assert (!value->lazy); |
| 903 | return value->contents; |
| 904 | } |
| 905 | |
| 906 | const gdb_byte * |
| 907 | value_contents_all (struct value *value) |
| 908 | { |
| 909 | const gdb_byte *result = value_contents_for_printing (value); |
| 910 | require_not_optimized_out (value); |
| 911 | require_available (value); |
| 912 | return result; |
| 913 | } |
| 914 | |
| 915 | /* Copy LENGTH bytes of SRC value's (all) contents |
| 916 | (value_contents_all) starting at SRC_OFFSET, into DST value's (all) |
| 917 | contents, starting at DST_OFFSET. If unavailable contents are |
| 918 | being copied from SRC, the corresponding DST contents are marked |
| 919 | unavailable accordingly. Neither DST nor SRC may be lazy |
| 920 | values. |
| 921 | |
| 922 | It is assumed the contents of DST in the [DST_OFFSET, |
| 923 | DST_OFFSET+LENGTH) range are wholly available. */ |
| 924 | |
| 925 | void |
| 926 | value_contents_copy_raw (struct value *dst, int dst_offset, |
| 927 | struct value *src, int src_offset, int length) |
| 928 | { |
| 929 | range_s *r; |
| 930 | int i; |
| 931 | |
| 932 | /* A lazy DST would make that this copy operation useless, since as |
| 933 | soon as DST's contents were un-lazied (by a later value_contents |
| 934 | call, say), the contents would be overwritten. A lazy SRC would |
| 935 | mean we'd be copying garbage. */ |
| 936 | gdb_assert (!dst->lazy && !src->lazy); |
| 937 | |
| 938 | /* The overwritten DST range gets unavailability ORed in, not |
| 939 | replaced. Make sure to remember to implement replacing if it |
| 940 | turns out actually necessary. */ |
| 941 | gdb_assert (value_bytes_available (dst, dst_offset, length)); |
| 942 | |
| 943 | /* Copy the data. */ |
| 944 | memcpy (value_contents_all_raw (dst) + dst_offset, |
| 945 | value_contents_all_raw (src) + src_offset, |
| 946 | length); |
| 947 | |
| 948 | /* Copy the meta-data, adjusted. */ |
| 949 | for (i = 0; VEC_iterate (range_s, src->unavailable, i, r); i++) |
| 950 | { |
| 951 | ULONGEST h, l; |
| 952 | |
| 953 | l = max (r->offset, src_offset); |
| 954 | h = min (r->offset + r->length, src_offset + length); |
| 955 | |
| 956 | if (l < h) |
| 957 | mark_value_bytes_unavailable (dst, |
| 958 | dst_offset + (l - src_offset), |
| 959 | h - l); |
| 960 | } |
| 961 | } |
| 962 | |
| 963 | /* Copy LENGTH bytes of SRC value's (all) contents |
| 964 | (value_contents_all) starting at SRC_OFFSET byte, into DST value's |
| 965 | (all) contents, starting at DST_OFFSET. If unavailable contents |
| 966 | are being copied from SRC, the corresponding DST contents are |
| 967 | marked unavailable accordingly. DST must not be lazy. If SRC is |
| 968 | lazy, it will be fetched now. If SRC is not valid (is optimized |
| 969 | out), an error is thrown. |
| 970 | |
| 971 | It is assumed the contents of DST in the [DST_OFFSET, |
| 972 | DST_OFFSET+LENGTH) range are wholly available. */ |
| 973 | |
| 974 | void |
| 975 | value_contents_copy (struct value *dst, int dst_offset, |
| 976 | struct value *src, int src_offset, int length) |
| 977 | { |
| 978 | require_not_optimized_out (src); |
| 979 | |
| 980 | if (src->lazy) |
| 981 | value_fetch_lazy (src); |
| 982 | |
| 983 | value_contents_copy_raw (dst, dst_offset, src, src_offset, length); |
| 984 | } |
| 985 | |
| 986 | int |
| 987 | value_lazy (struct value *value) |
| 988 | { |
| 989 | return value->lazy; |
| 990 | } |
| 991 | |
| 992 | void |
| 993 | set_value_lazy (struct value *value, int val) |
| 994 | { |
| 995 | value->lazy = val; |
| 996 | } |
| 997 | |
| 998 | int |
| 999 | value_stack (struct value *value) |
| 1000 | { |
| 1001 | return value->stack; |
| 1002 | } |
| 1003 | |
| 1004 | void |
| 1005 | set_value_stack (struct value *value, int val) |
| 1006 | { |
| 1007 | value->stack = val; |
| 1008 | } |
| 1009 | |
| 1010 | const gdb_byte * |
| 1011 | value_contents (struct value *value) |
| 1012 | { |
| 1013 | const gdb_byte *result = value_contents_writeable (value); |
| 1014 | require_not_optimized_out (value); |
| 1015 | require_available (value); |
| 1016 | return result; |
| 1017 | } |
| 1018 | |
| 1019 | gdb_byte * |
| 1020 | value_contents_writeable (struct value *value) |
| 1021 | { |
| 1022 | if (value->lazy) |
| 1023 | value_fetch_lazy (value); |
| 1024 | return value_contents_raw (value); |
| 1025 | } |
| 1026 | |
| 1027 | /* Return non-zero if VAL1 and VAL2 have the same contents. Note that |
| 1028 | this function is different from value_equal; in C the operator == |
| 1029 | can return 0 even if the two values being compared are equal. */ |
| 1030 | |
| 1031 | int |
| 1032 | value_contents_equal (struct value *val1, struct value *val2) |
| 1033 | { |
| 1034 | struct type *type1; |
| 1035 | struct type *type2; |
| 1036 | int len; |
| 1037 | |
| 1038 | type1 = check_typedef (value_type (val1)); |
| 1039 | type2 = check_typedef (value_type (val2)); |
| 1040 | len = TYPE_LENGTH (type1); |
| 1041 | if (len != TYPE_LENGTH (type2)) |
| 1042 | return 0; |
| 1043 | |
| 1044 | return (memcmp (value_contents (val1), value_contents (val2), len) == 0); |
| 1045 | } |
| 1046 | |
| 1047 | int |
| 1048 | value_optimized_out (struct value *value) |
| 1049 | { |
| 1050 | return value->optimized_out; |
| 1051 | } |
| 1052 | |
| 1053 | void |
| 1054 | set_value_optimized_out (struct value *value, int val) |
| 1055 | { |
| 1056 | value->optimized_out = val; |
| 1057 | } |
| 1058 | |
| 1059 | int |
| 1060 | value_entirely_optimized_out (const struct value *value) |
| 1061 | { |
| 1062 | if (!value->optimized_out) |
| 1063 | return 0; |
| 1064 | if (value->lval != lval_computed |
| 1065 | || !value->location.computed.funcs->check_any_valid) |
| 1066 | return 1; |
| 1067 | return !value->location.computed.funcs->check_any_valid (value); |
| 1068 | } |
| 1069 | |
| 1070 | int |
| 1071 | value_bits_valid (const struct value *value, int offset, int length) |
| 1072 | { |
| 1073 | if (!value->optimized_out) |
| 1074 | return 1; |
| 1075 | if (value->lval != lval_computed |
| 1076 | || !value->location.computed.funcs->check_validity) |
| 1077 | return 0; |
| 1078 | return value->location.computed.funcs->check_validity (value, offset, |
| 1079 | length); |
| 1080 | } |
| 1081 | |
| 1082 | int |
| 1083 | value_bits_synthetic_pointer (const struct value *value, |
| 1084 | int offset, int length) |
| 1085 | { |
| 1086 | if (value->lval != lval_computed |
| 1087 | || !value->location.computed.funcs->check_synthetic_pointer) |
| 1088 | return 0; |
| 1089 | return value->location.computed.funcs->check_synthetic_pointer (value, |
| 1090 | offset, |
| 1091 | length); |
| 1092 | } |
| 1093 | |
| 1094 | int |
| 1095 | value_embedded_offset (struct value *value) |
| 1096 | { |
| 1097 | return value->embedded_offset; |
| 1098 | } |
| 1099 | |
| 1100 | void |
| 1101 | set_value_embedded_offset (struct value *value, int val) |
| 1102 | { |
| 1103 | value->embedded_offset = val; |
| 1104 | } |
| 1105 | |
| 1106 | int |
| 1107 | value_pointed_to_offset (struct value *value) |
| 1108 | { |
| 1109 | return value->pointed_to_offset; |
| 1110 | } |
| 1111 | |
| 1112 | void |
| 1113 | set_value_pointed_to_offset (struct value *value, int val) |
| 1114 | { |
| 1115 | value->pointed_to_offset = val; |
| 1116 | } |
| 1117 | |
| 1118 | const struct lval_funcs * |
| 1119 | value_computed_funcs (const struct value *v) |
| 1120 | { |
| 1121 | gdb_assert (value_lval_const (v) == lval_computed); |
| 1122 | |
| 1123 | return v->location.computed.funcs; |
| 1124 | } |
| 1125 | |
| 1126 | void * |
| 1127 | value_computed_closure (const struct value *v) |
| 1128 | { |
| 1129 | gdb_assert (v->lval == lval_computed); |
| 1130 | |
| 1131 | return v->location.computed.closure; |
| 1132 | } |
| 1133 | |
| 1134 | enum lval_type * |
| 1135 | deprecated_value_lval_hack (struct value *value) |
| 1136 | { |
| 1137 | return &value->lval; |
| 1138 | } |
| 1139 | |
| 1140 | enum lval_type |
| 1141 | value_lval_const (const struct value *value) |
| 1142 | { |
| 1143 | return value->lval; |
| 1144 | } |
| 1145 | |
| 1146 | CORE_ADDR |
| 1147 | value_address (const struct value *value) |
| 1148 | { |
| 1149 | if (value->lval == lval_internalvar |
| 1150 | || value->lval == lval_internalvar_component) |
| 1151 | return 0; |
| 1152 | if (value->parent != NULL) |
| 1153 | return value_address (value->parent) + value->offset; |
| 1154 | else |
| 1155 | return value->location.address + value->offset; |
| 1156 | } |
| 1157 | |
| 1158 | CORE_ADDR |
| 1159 | value_raw_address (struct value *value) |
| 1160 | { |
| 1161 | if (value->lval == lval_internalvar |
| 1162 | || value->lval == lval_internalvar_component) |
| 1163 | return 0; |
| 1164 | return value->location.address; |
| 1165 | } |
| 1166 | |
| 1167 | void |
| 1168 | set_value_address (struct value *value, CORE_ADDR addr) |
| 1169 | { |
| 1170 | gdb_assert (value->lval != lval_internalvar |
| 1171 | && value->lval != lval_internalvar_component); |
| 1172 | value->location.address = addr; |
| 1173 | } |
| 1174 | |
| 1175 | struct internalvar ** |
| 1176 | deprecated_value_internalvar_hack (struct value *value) |
| 1177 | { |
| 1178 | return &value->location.internalvar; |
| 1179 | } |
| 1180 | |
| 1181 | struct frame_id * |
| 1182 | deprecated_value_frame_id_hack (struct value *value) |
| 1183 | { |
| 1184 | return &value->frame_id; |
| 1185 | } |
| 1186 | |
| 1187 | short * |
| 1188 | deprecated_value_regnum_hack (struct value *value) |
| 1189 | { |
| 1190 | return &value->regnum; |
| 1191 | } |
| 1192 | |
| 1193 | int |
| 1194 | deprecated_value_modifiable (struct value *value) |
| 1195 | { |
| 1196 | return value->modifiable; |
| 1197 | } |
| 1198 | void |
| 1199 | deprecated_set_value_modifiable (struct value *value, int modifiable) |
| 1200 | { |
| 1201 | value->modifiable = modifiable; |
| 1202 | } |
| 1203 | \f |
| 1204 | /* Return a mark in the value chain. All values allocated after the |
| 1205 | mark is obtained (except for those released) are subject to being freed |
| 1206 | if a subsequent value_free_to_mark is passed the mark. */ |
| 1207 | struct value * |
| 1208 | value_mark (void) |
| 1209 | { |
| 1210 | return all_values; |
| 1211 | } |
| 1212 | |
| 1213 | /* Take a reference to VAL. VAL will not be deallocated until all |
| 1214 | references are released. */ |
| 1215 | |
| 1216 | void |
| 1217 | value_incref (struct value *val) |
| 1218 | { |
| 1219 | val->reference_count++; |
| 1220 | } |
| 1221 | |
| 1222 | /* Release a reference to VAL, which was acquired with value_incref. |
| 1223 | This function is also called to deallocate values from the value |
| 1224 | chain. */ |
| 1225 | |
| 1226 | void |
| 1227 | value_free (struct value *val) |
| 1228 | { |
| 1229 | if (val) |
| 1230 | { |
| 1231 | gdb_assert (val->reference_count > 0); |
| 1232 | val->reference_count--; |
| 1233 | if (val->reference_count > 0) |
| 1234 | return; |
| 1235 | |
| 1236 | /* If there's an associated parent value, drop our reference to |
| 1237 | it. */ |
| 1238 | if (val->parent != NULL) |
| 1239 | value_free (val->parent); |
| 1240 | |
| 1241 | if (VALUE_LVAL (val) == lval_computed) |
| 1242 | { |
| 1243 | const struct lval_funcs *funcs = val->location.computed.funcs; |
| 1244 | |
| 1245 | if (funcs->free_closure) |
| 1246 | funcs->free_closure (val); |
| 1247 | } |
| 1248 | |
| 1249 | xfree (val->contents); |
| 1250 | VEC_free (range_s, val->unavailable); |
| 1251 | } |
| 1252 | xfree (val); |
| 1253 | } |
| 1254 | |
| 1255 | /* Free all values allocated since MARK was obtained by value_mark |
| 1256 | (except for those released). */ |
| 1257 | void |
| 1258 | value_free_to_mark (struct value *mark) |
| 1259 | { |
| 1260 | struct value *val; |
| 1261 | struct value *next; |
| 1262 | |
| 1263 | for (val = all_values; val && val != mark; val = next) |
| 1264 | { |
| 1265 | next = val->next; |
| 1266 | val->released = 1; |
| 1267 | value_free (val); |
| 1268 | } |
| 1269 | all_values = val; |
| 1270 | } |
| 1271 | |
| 1272 | /* Free all the values that have been allocated (except for those released). |
| 1273 | Call after each command, successful or not. |
| 1274 | In practice this is called before each command, which is sufficient. */ |
| 1275 | |
| 1276 | void |
| 1277 | free_all_values (void) |
| 1278 | { |
| 1279 | struct value *val; |
| 1280 | struct value *next; |
| 1281 | |
| 1282 | for (val = all_values; val; val = next) |
| 1283 | { |
| 1284 | next = val->next; |
| 1285 | val->released = 1; |
| 1286 | value_free (val); |
| 1287 | } |
| 1288 | |
| 1289 | all_values = 0; |
| 1290 | } |
| 1291 | |
| 1292 | /* Frees all the elements in a chain of values. */ |
| 1293 | |
| 1294 | void |
| 1295 | free_value_chain (struct value *v) |
| 1296 | { |
| 1297 | struct value *next; |
| 1298 | |
| 1299 | for (; v; v = next) |
| 1300 | { |
| 1301 | next = value_next (v); |
| 1302 | value_free (v); |
| 1303 | } |
| 1304 | } |
| 1305 | |
| 1306 | /* Remove VAL from the chain all_values |
| 1307 | so it will not be freed automatically. */ |
| 1308 | |
| 1309 | void |
| 1310 | release_value (struct value *val) |
| 1311 | { |
| 1312 | struct value *v; |
| 1313 | |
| 1314 | if (all_values == val) |
| 1315 | { |
| 1316 | all_values = val->next; |
| 1317 | val->next = NULL; |
| 1318 | val->released = 1; |
| 1319 | return; |
| 1320 | } |
| 1321 | |
| 1322 | for (v = all_values; v; v = v->next) |
| 1323 | { |
| 1324 | if (v->next == val) |
| 1325 | { |
| 1326 | v->next = val->next; |
| 1327 | val->next = NULL; |
| 1328 | val->released = 1; |
| 1329 | break; |
| 1330 | } |
| 1331 | } |
| 1332 | } |
| 1333 | |
| 1334 | /* If the value is not already released, release it. |
| 1335 | If the value is already released, increment its reference count. |
| 1336 | That is, this function ensures that the value is released from the |
| 1337 | value chain and that the caller owns a reference to it. */ |
| 1338 | |
| 1339 | void |
| 1340 | release_value_or_incref (struct value *val) |
| 1341 | { |
| 1342 | if (val->released) |
| 1343 | value_incref (val); |
| 1344 | else |
| 1345 | release_value (val); |
| 1346 | } |
| 1347 | |
| 1348 | /* Release all values up to mark */ |
| 1349 | struct value * |
| 1350 | value_release_to_mark (struct value *mark) |
| 1351 | { |
| 1352 | struct value *val; |
| 1353 | struct value *next; |
| 1354 | |
| 1355 | for (val = next = all_values; next; next = next->next) |
| 1356 | { |
| 1357 | if (next->next == mark) |
| 1358 | { |
| 1359 | all_values = next->next; |
| 1360 | next->next = NULL; |
| 1361 | return val; |
| 1362 | } |
| 1363 | next->released = 1; |
| 1364 | } |
| 1365 | all_values = 0; |
| 1366 | return val; |
| 1367 | } |
| 1368 | |
| 1369 | /* Return a copy of the value ARG. |
| 1370 | It contains the same contents, for same memory address, |
| 1371 | but it's a different block of storage. */ |
| 1372 | |
| 1373 | struct value * |
| 1374 | value_copy (struct value *arg) |
| 1375 | { |
| 1376 | struct type *encl_type = value_enclosing_type (arg); |
| 1377 | struct value *val; |
| 1378 | |
| 1379 | if (value_lazy (arg)) |
| 1380 | val = allocate_value_lazy (encl_type); |
| 1381 | else |
| 1382 | val = allocate_value (encl_type); |
| 1383 | val->type = arg->type; |
| 1384 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
| 1385 | val->location = arg->location; |
| 1386 | val->offset = arg->offset; |
| 1387 | val->bitpos = arg->bitpos; |
| 1388 | val->bitsize = arg->bitsize; |
| 1389 | VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
| 1390 | VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
| 1391 | val->lazy = arg->lazy; |
| 1392 | val->optimized_out = arg->optimized_out; |
| 1393 | val->embedded_offset = value_embedded_offset (arg); |
| 1394 | val->pointed_to_offset = arg->pointed_to_offset; |
| 1395 | val->modifiable = arg->modifiable; |
| 1396 | if (!value_lazy (val)) |
| 1397 | { |
| 1398 | memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
| 1399 | TYPE_LENGTH (value_enclosing_type (arg))); |
| 1400 | |
| 1401 | } |
| 1402 | val->unavailable = VEC_copy (range_s, arg->unavailable); |
| 1403 | val->parent = arg->parent; |
| 1404 | if (val->parent) |
| 1405 | value_incref (val->parent); |
| 1406 | if (VALUE_LVAL (val) == lval_computed) |
| 1407 | { |
| 1408 | const struct lval_funcs *funcs = val->location.computed.funcs; |
| 1409 | |
| 1410 | if (funcs->copy_closure) |
| 1411 | val->location.computed.closure = funcs->copy_closure (val); |
| 1412 | } |
| 1413 | return val; |
| 1414 | } |
| 1415 | |
| 1416 | /* Return a version of ARG that is non-lvalue. */ |
| 1417 | |
| 1418 | struct value * |
| 1419 | value_non_lval (struct value *arg) |
| 1420 | { |
| 1421 | if (VALUE_LVAL (arg) != not_lval) |
| 1422 | { |
| 1423 | struct type *enc_type = value_enclosing_type (arg); |
| 1424 | struct value *val = allocate_value (enc_type); |
| 1425 | |
| 1426 | memcpy (value_contents_all_raw (val), value_contents_all (arg), |
| 1427 | TYPE_LENGTH (enc_type)); |
| 1428 | val->type = arg->type; |
| 1429 | set_value_embedded_offset (val, value_embedded_offset (arg)); |
| 1430 | set_value_pointed_to_offset (val, value_pointed_to_offset (arg)); |
| 1431 | return val; |
| 1432 | } |
| 1433 | return arg; |
| 1434 | } |
| 1435 | |
| 1436 | void |
| 1437 | set_value_component_location (struct value *component, |
| 1438 | const struct value *whole) |
| 1439 | { |
| 1440 | if (whole->lval == lval_internalvar) |
| 1441 | VALUE_LVAL (component) = lval_internalvar_component; |
| 1442 | else |
| 1443 | VALUE_LVAL (component) = whole->lval; |
| 1444 | |
| 1445 | component->location = whole->location; |
| 1446 | if (whole->lval == lval_computed) |
| 1447 | { |
| 1448 | const struct lval_funcs *funcs = whole->location.computed.funcs; |
| 1449 | |
| 1450 | if (funcs->copy_closure) |
| 1451 | component->location.computed.closure = funcs->copy_closure (whole); |
| 1452 | } |
| 1453 | } |
| 1454 | |
| 1455 | \f |
| 1456 | /* Access to the value history. */ |
| 1457 | |
| 1458 | /* Record a new value in the value history. |
| 1459 | Returns the absolute history index of the entry. |
| 1460 | Result of -1 indicates the value was not saved; otherwise it is the |
| 1461 | value history index of this new item. */ |
| 1462 | |
| 1463 | int |
| 1464 | record_latest_value (struct value *val) |
| 1465 | { |
| 1466 | int i; |
| 1467 | |
| 1468 | /* We don't want this value to have anything to do with the inferior anymore. |
| 1469 | In particular, "set $1 = 50" should not affect the variable from which |
| 1470 | the value was taken, and fast watchpoints should be able to assume that |
| 1471 | a value on the value history never changes. */ |
| 1472 | if (value_lazy (val)) |
| 1473 | value_fetch_lazy (val); |
| 1474 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched |
| 1475 | from. This is a bit dubious, because then *&$1 does not just return $1 |
| 1476 | but the current contents of that location. c'est la vie... */ |
| 1477 | val->modifiable = 0; |
| 1478 | release_value (val); |
| 1479 | |
| 1480 | /* Here we treat value_history_count as origin-zero |
| 1481 | and applying to the value being stored now. */ |
| 1482 | |
| 1483 | i = value_history_count % VALUE_HISTORY_CHUNK; |
| 1484 | if (i == 0) |
| 1485 | { |
| 1486 | struct value_history_chunk *new |
| 1487 | = (struct value_history_chunk *) |
| 1488 | |
| 1489 | xmalloc (sizeof (struct value_history_chunk)); |
| 1490 | memset (new->values, 0, sizeof new->values); |
| 1491 | new->next = value_history_chain; |
| 1492 | value_history_chain = new; |
| 1493 | } |
| 1494 | |
| 1495 | value_history_chain->values[i] = val; |
| 1496 | |
| 1497 | /* Now we regard value_history_count as origin-one |
| 1498 | and applying to the value just stored. */ |
| 1499 | |
| 1500 | return ++value_history_count; |
| 1501 | } |
| 1502 | |
| 1503 | /* Return a copy of the value in the history with sequence number NUM. */ |
| 1504 | |
| 1505 | struct value * |
| 1506 | access_value_history (int num) |
| 1507 | { |
| 1508 | struct value_history_chunk *chunk; |
| 1509 | int i; |
| 1510 | int absnum = num; |
| 1511 | |
| 1512 | if (absnum <= 0) |
| 1513 | absnum += value_history_count; |
| 1514 | |
| 1515 | if (absnum <= 0) |
| 1516 | { |
| 1517 | if (num == 0) |
| 1518 | error (_("The history is empty.")); |
| 1519 | else if (num == 1) |
| 1520 | error (_("There is only one value in the history.")); |
| 1521 | else |
| 1522 | error (_("History does not go back to $$%d."), -num); |
| 1523 | } |
| 1524 | if (absnum > value_history_count) |
| 1525 | error (_("History has not yet reached $%d."), absnum); |
| 1526 | |
| 1527 | absnum--; |
| 1528 | |
| 1529 | /* Now absnum is always absolute and origin zero. */ |
| 1530 | |
| 1531 | chunk = value_history_chain; |
| 1532 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK |
| 1533 | - absnum / VALUE_HISTORY_CHUNK; |
| 1534 | i > 0; i--) |
| 1535 | chunk = chunk->next; |
| 1536 | |
| 1537 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); |
| 1538 | } |
| 1539 | |
| 1540 | static void |
| 1541 | show_values (char *num_exp, int from_tty) |
| 1542 | { |
| 1543 | int i; |
| 1544 | struct value *val; |
| 1545 | static int num = 1; |
| 1546 | |
| 1547 | if (num_exp) |
| 1548 | { |
| 1549 | /* "show values +" should print from the stored position. |
| 1550 | "show values <exp>" should print around value number <exp>. */ |
| 1551 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
| 1552 | num = parse_and_eval_long (num_exp) - 5; |
| 1553 | } |
| 1554 | else |
| 1555 | { |
| 1556 | /* "show values" means print the last 10 values. */ |
| 1557 | num = value_history_count - 9; |
| 1558 | } |
| 1559 | |
| 1560 | if (num <= 0) |
| 1561 | num = 1; |
| 1562 | |
| 1563 | for (i = num; i < num + 10 && i <= value_history_count; i++) |
| 1564 | { |
| 1565 | struct value_print_options opts; |
| 1566 | |
| 1567 | val = access_value_history (i); |
| 1568 | printf_filtered (("$%d = "), i); |
| 1569 | get_user_print_options (&opts); |
| 1570 | value_print (val, gdb_stdout, &opts); |
| 1571 | printf_filtered (("\n")); |
| 1572 | } |
| 1573 | |
| 1574 | /* The next "show values +" should start after what we just printed. */ |
| 1575 | num += 10; |
| 1576 | |
| 1577 | /* Hitting just return after this command should do the same thing as |
| 1578 | "show values +". If num_exp is null, this is unnecessary, since |
| 1579 | "show values +" is not useful after "show values". */ |
| 1580 | if (from_tty && num_exp) |
| 1581 | { |
| 1582 | num_exp[0] = '+'; |
| 1583 | num_exp[1] = '\0'; |
| 1584 | } |
| 1585 | } |
| 1586 | \f |
| 1587 | /* Internal variables. These are variables within the debugger |
| 1588 | that hold values assigned by debugger commands. |
| 1589 | The user refers to them with a '$' prefix |
| 1590 | that does not appear in the variable names stored internally. */ |
| 1591 | |
| 1592 | struct internalvar |
| 1593 | { |
| 1594 | struct internalvar *next; |
| 1595 | char *name; |
| 1596 | |
| 1597 | /* We support various different kinds of content of an internal variable. |
| 1598 | enum internalvar_kind specifies the kind, and union internalvar_data |
| 1599 | provides the data associated with this particular kind. */ |
| 1600 | |
| 1601 | enum internalvar_kind |
| 1602 | { |
| 1603 | /* The internal variable is empty. */ |
| 1604 | INTERNALVAR_VOID, |
| 1605 | |
| 1606 | /* The value of the internal variable is provided directly as |
| 1607 | a GDB value object. */ |
| 1608 | INTERNALVAR_VALUE, |
| 1609 | |
| 1610 | /* A fresh value is computed via a call-back routine on every |
| 1611 | access to the internal variable. */ |
| 1612 | INTERNALVAR_MAKE_VALUE, |
| 1613 | |
| 1614 | /* The internal variable holds a GDB internal convenience function. */ |
| 1615 | INTERNALVAR_FUNCTION, |
| 1616 | |
| 1617 | /* The variable holds an integer value. */ |
| 1618 | INTERNALVAR_INTEGER, |
| 1619 | |
| 1620 | /* The variable holds a GDB-provided string. */ |
| 1621 | INTERNALVAR_STRING, |
| 1622 | |
| 1623 | } kind; |
| 1624 | |
| 1625 | union internalvar_data |
| 1626 | { |
| 1627 | /* A value object used with INTERNALVAR_VALUE. */ |
| 1628 | struct value *value; |
| 1629 | |
| 1630 | /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */ |
| 1631 | struct |
| 1632 | { |
| 1633 | /* The functions to call. */ |
| 1634 | const struct internalvar_funcs *functions; |
| 1635 | |
| 1636 | /* The function's user-data. */ |
| 1637 | void *data; |
| 1638 | } make_value; |
| 1639 | |
| 1640 | /* The internal function used with INTERNALVAR_FUNCTION. */ |
| 1641 | struct |
| 1642 | { |
| 1643 | struct internal_function *function; |
| 1644 | /* True if this is the canonical name for the function. */ |
| 1645 | int canonical; |
| 1646 | } fn; |
| 1647 | |
| 1648 | /* An integer value used with INTERNALVAR_INTEGER. */ |
| 1649 | struct |
| 1650 | { |
| 1651 | /* If type is non-NULL, it will be used as the type to generate |
| 1652 | a value for this internal variable. If type is NULL, a default |
| 1653 | integer type for the architecture is used. */ |
| 1654 | struct type *type; |
| 1655 | LONGEST val; |
| 1656 | } integer; |
| 1657 | |
| 1658 | /* A string value used with INTERNALVAR_STRING. */ |
| 1659 | char *string; |
| 1660 | } u; |
| 1661 | }; |
| 1662 | |
| 1663 | static struct internalvar *internalvars; |
| 1664 | |
| 1665 | /* If the variable does not already exist create it and give it the |
| 1666 | value given. If no value is given then the default is zero. */ |
| 1667 | static void |
| 1668 | init_if_undefined_command (char* args, int from_tty) |
| 1669 | { |
| 1670 | struct internalvar* intvar; |
| 1671 | |
| 1672 | /* Parse the expression - this is taken from set_command(). */ |
| 1673 | struct expression *expr = parse_expression (args); |
| 1674 | register struct cleanup *old_chain = |
| 1675 | make_cleanup (free_current_contents, &expr); |
| 1676 | |
| 1677 | /* Validate the expression. |
| 1678 | Was the expression an assignment? |
| 1679 | Or even an expression at all? */ |
| 1680 | if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN) |
| 1681 | error (_("Init-if-undefined requires an assignment expression.")); |
| 1682 | |
| 1683 | /* Extract the variable from the parsed expression. |
| 1684 | In the case of an assign the lvalue will be in elts[1] and elts[2]. */ |
| 1685 | if (expr->elts[1].opcode != OP_INTERNALVAR) |
| 1686 | error (_("The first parameter to init-if-undefined " |
| 1687 | "should be a GDB variable.")); |
| 1688 | intvar = expr->elts[2].internalvar; |
| 1689 | |
| 1690 | /* Only evaluate the expression if the lvalue is void. |
| 1691 | This may still fail if the expresssion is invalid. */ |
| 1692 | if (intvar->kind == INTERNALVAR_VOID) |
| 1693 | evaluate_expression (expr); |
| 1694 | |
| 1695 | do_cleanups (old_chain); |
| 1696 | } |
| 1697 | |
| 1698 | |
| 1699 | /* Look up an internal variable with name NAME. NAME should not |
| 1700 | normally include a dollar sign. |
| 1701 | |
| 1702 | If the specified internal variable does not exist, |
| 1703 | the return value is NULL. */ |
| 1704 | |
| 1705 | struct internalvar * |
| 1706 | lookup_only_internalvar (const char *name) |
| 1707 | { |
| 1708 | struct internalvar *var; |
| 1709 | |
| 1710 | for (var = internalvars; var; var = var->next) |
| 1711 | if (strcmp (var->name, name) == 0) |
| 1712 | return var; |
| 1713 | |
| 1714 | return NULL; |
| 1715 | } |
| 1716 | |
| 1717 | /* Complete NAME by comparing it to the names of internal variables. |
| 1718 | Returns a vector of newly allocated strings, or NULL if no matches |
| 1719 | were found. */ |
| 1720 | |
| 1721 | VEC (char_ptr) * |
| 1722 | complete_internalvar (const char *name) |
| 1723 | { |
| 1724 | VEC (char_ptr) *result = NULL; |
| 1725 | struct internalvar *var; |
| 1726 | int len; |
| 1727 | |
| 1728 | len = strlen (name); |
| 1729 | |
| 1730 | for (var = internalvars; var; var = var->next) |
| 1731 | if (strncmp (var->name, name, len) == 0) |
| 1732 | { |
| 1733 | char *r = xstrdup (var->name); |
| 1734 | |
| 1735 | VEC_safe_push (char_ptr, result, r); |
| 1736 | } |
| 1737 | |
| 1738 | return result; |
| 1739 | } |
| 1740 | |
| 1741 | /* Create an internal variable with name NAME and with a void value. |
| 1742 | NAME should not normally include a dollar sign. */ |
| 1743 | |
| 1744 | struct internalvar * |
| 1745 | create_internalvar (const char *name) |
| 1746 | { |
| 1747 | struct internalvar *var; |
| 1748 | |
| 1749 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
| 1750 | var->name = concat (name, (char *)NULL); |
| 1751 | var->kind = INTERNALVAR_VOID; |
| 1752 | var->next = internalvars; |
| 1753 | internalvars = var; |
| 1754 | return var; |
| 1755 | } |
| 1756 | |
| 1757 | /* Create an internal variable with name NAME and register FUN as the |
| 1758 | function that value_of_internalvar uses to create a value whenever |
| 1759 | this variable is referenced. NAME should not normally include a |
| 1760 | dollar sign. DATA is passed uninterpreted to FUN when it is |
| 1761 | called. CLEANUP, if not NULL, is called when the internal variable |
| 1762 | is destroyed. It is passed DATA as its only argument. */ |
| 1763 | |
| 1764 | struct internalvar * |
| 1765 | create_internalvar_type_lazy (const char *name, |
| 1766 | const struct internalvar_funcs *funcs, |
| 1767 | void *data) |
| 1768 | { |
| 1769 | struct internalvar *var = create_internalvar (name); |
| 1770 | |
| 1771 | var->kind = INTERNALVAR_MAKE_VALUE; |
| 1772 | var->u.make_value.functions = funcs; |
| 1773 | var->u.make_value.data = data; |
| 1774 | return var; |
| 1775 | } |
| 1776 | |
| 1777 | /* See documentation in value.h. */ |
| 1778 | |
| 1779 | int |
| 1780 | compile_internalvar_to_ax (struct internalvar *var, |
| 1781 | struct agent_expr *expr, |
| 1782 | struct axs_value *value) |
| 1783 | { |
| 1784 | if (var->kind != INTERNALVAR_MAKE_VALUE |
| 1785 | || var->u.make_value.functions->compile_to_ax == NULL) |
| 1786 | return 0; |
| 1787 | |
| 1788 | var->u.make_value.functions->compile_to_ax (var, expr, value, |
| 1789 | var->u.make_value.data); |
| 1790 | return 1; |
| 1791 | } |
| 1792 | |
| 1793 | /* Look up an internal variable with name NAME. NAME should not |
| 1794 | normally include a dollar sign. |
| 1795 | |
| 1796 | If the specified internal variable does not exist, |
| 1797 | one is created, with a void value. */ |
| 1798 | |
| 1799 | struct internalvar * |
| 1800 | lookup_internalvar (const char *name) |
| 1801 | { |
| 1802 | struct internalvar *var; |
| 1803 | |
| 1804 | var = lookup_only_internalvar (name); |
| 1805 | if (var) |
| 1806 | return var; |
| 1807 | |
| 1808 | return create_internalvar (name); |
| 1809 | } |
| 1810 | |
| 1811 | /* Return current value of internal variable VAR. For variables that |
| 1812 | are not inherently typed, use a value type appropriate for GDBARCH. */ |
| 1813 | |
| 1814 | struct value * |
| 1815 | value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var) |
| 1816 | { |
| 1817 | struct value *val; |
| 1818 | struct trace_state_variable *tsv; |
| 1819 | |
| 1820 | /* If there is a trace state variable of the same name, assume that |
| 1821 | is what we really want to see. */ |
| 1822 | tsv = find_trace_state_variable (var->name); |
| 1823 | if (tsv) |
| 1824 | { |
| 1825 | tsv->value_known = target_get_trace_state_variable_value (tsv->number, |
| 1826 | &(tsv->value)); |
| 1827 | if (tsv->value_known) |
| 1828 | val = value_from_longest (builtin_type (gdbarch)->builtin_int64, |
| 1829 | tsv->value); |
| 1830 | else |
| 1831 | val = allocate_value (builtin_type (gdbarch)->builtin_void); |
| 1832 | return val; |
| 1833 | } |
| 1834 | |
| 1835 | switch (var->kind) |
| 1836 | { |
| 1837 | case INTERNALVAR_VOID: |
| 1838 | val = allocate_value (builtin_type (gdbarch)->builtin_void); |
| 1839 | break; |
| 1840 | |
| 1841 | case INTERNALVAR_FUNCTION: |
| 1842 | val = allocate_value (builtin_type (gdbarch)->internal_fn); |
| 1843 | break; |
| 1844 | |
| 1845 | case INTERNALVAR_INTEGER: |
| 1846 | if (!var->u.integer.type) |
| 1847 | val = value_from_longest (builtin_type (gdbarch)->builtin_int, |
| 1848 | var->u.integer.val); |
| 1849 | else |
| 1850 | val = value_from_longest (var->u.integer.type, var->u.integer.val); |
| 1851 | break; |
| 1852 | |
| 1853 | case INTERNALVAR_STRING: |
| 1854 | val = value_cstring (var->u.string, strlen (var->u.string), |
| 1855 | builtin_type (gdbarch)->builtin_char); |
| 1856 | break; |
| 1857 | |
| 1858 | case INTERNALVAR_VALUE: |
| 1859 | val = value_copy (var->u.value); |
| 1860 | if (value_lazy (val)) |
| 1861 | value_fetch_lazy (val); |
| 1862 | break; |
| 1863 | |
| 1864 | case INTERNALVAR_MAKE_VALUE: |
| 1865 | val = (*var->u.make_value.functions->make_value) (gdbarch, var, |
| 1866 | var->u.make_value.data); |
| 1867 | break; |
| 1868 | |
| 1869 | default: |
| 1870 | internal_error (__FILE__, __LINE__, _("bad kind")); |
| 1871 | } |
| 1872 | |
| 1873 | /* Change the VALUE_LVAL to lval_internalvar so that future operations |
| 1874 | on this value go back to affect the original internal variable. |
| 1875 | |
| 1876 | Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have |
| 1877 | no underlying modifyable state in the internal variable. |
| 1878 | |
| 1879 | Likewise, if the variable's value is a computed lvalue, we want |
| 1880 | references to it to produce another computed lvalue, where |
| 1881 | references and assignments actually operate through the |
| 1882 | computed value's functions. |
| 1883 | |
| 1884 | This means that internal variables with computed values |
| 1885 | behave a little differently from other internal variables: |
| 1886 | assignments to them don't just replace the previous value |
| 1887 | altogether. At the moment, this seems like the behavior we |
| 1888 | want. */ |
| 1889 | |
| 1890 | if (var->kind != INTERNALVAR_MAKE_VALUE |
| 1891 | && val->lval != lval_computed) |
| 1892 | { |
| 1893 | VALUE_LVAL (val) = lval_internalvar; |
| 1894 | VALUE_INTERNALVAR (val) = var; |
| 1895 | } |
| 1896 | |
| 1897 | return val; |
| 1898 | } |
| 1899 | |
| 1900 | int |
| 1901 | get_internalvar_integer (struct internalvar *var, LONGEST *result) |
| 1902 | { |
| 1903 | if (var->kind == INTERNALVAR_INTEGER) |
| 1904 | { |
| 1905 | *result = var->u.integer.val; |
| 1906 | return 1; |
| 1907 | } |
| 1908 | |
| 1909 | if (var->kind == INTERNALVAR_VALUE) |
| 1910 | { |
| 1911 | struct type *type = check_typedef (value_type (var->u.value)); |
| 1912 | |
| 1913 | if (TYPE_CODE (type) == TYPE_CODE_INT) |
| 1914 | { |
| 1915 | *result = value_as_long (var->u.value); |
| 1916 | return 1; |
| 1917 | } |
| 1918 | } |
| 1919 | |
| 1920 | return 0; |
| 1921 | } |
| 1922 | |
| 1923 | static int |
| 1924 | get_internalvar_function (struct internalvar *var, |
| 1925 | struct internal_function **result) |
| 1926 | { |
| 1927 | switch (var->kind) |
| 1928 | { |
| 1929 | case INTERNALVAR_FUNCTION: |
| 1930 | *result = var->u.fn.function; |
| 1931 | return 1; |
| 1932 | |
| 1933 | default: |
| 1934 | return 0; |
| 1935 | } |
| 1936 | } |
| 1937 | |
| 1938 | void |
| 1939 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
| 1940 | int bitsize, struct value *newval) |
| 1941 | { |
| 1942 | gdb_byte *addr; |
| 1943 | |
| 1944 | switch (var->kind) |
| 1945 | { |
| 1946 | case INTERNALVAR_VALUE: |
| 1947 | addr = value_contents_writeable (var->u.value); |
| 1948 | |
| 1949 | if (bitsize) |
| 1950 | modify_field (value_type (var->u.value), addr + offset, |
| 1951 | value_as_long (newval), bitpos, bitsize); |
| 1952 | else |
| 1953 | memcpy (addr + offset, value_contents (newval), |
| 1954 | TYPE_LENGTH (value_type (newval))); |
| 1955 | break; |
| 1956 | |
| 1957 | default: |
| 1958 | /* We can never get a component of any other kind. */ |
| 1959 | internal_error (__FILE__, __LINE__, _("set_internalvar_component")); |
| 1960 | } |
| 1961 | } |
| 1962 | |
| 1963 | void |
| 1964 | set_internalvar (struct internalvar *var, struct value *val) |
| 1965 | { |
| 1966 | enum internalvar_kind new_kind; |
| 1967 | union internalvar_data new_data = { 0 }; |
| 1968 | |
| 1969 | if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical) |
| 1970 | error (_("Cannot overwrite convenience function %s"), var->name); |
| 1971 | |
| 1972 | /* Prepare new contents. */ |
| 1973 | switch (TYPE_CODE (check_typedef (value_type (val)))) |
| 1974 | { |
| 1975 | case TYPE_CODE_VOID: |
| 1976 | new_kind = INTERNALVAR_VOID; |
| 1977 | break; |
| 1978 | |
| 1979 | case TYPE_CODE_INTERNAL_FUNCTION: |
| 1980 | gdb_assert (VALUE_LVAL (val) == lval_internalvar); |
| 1981 | new_kind = INTERNALVAR_FUNCTION; |
| 1982 | get_internalvar_function (VALUE_INTERNALVAR (val), |
| 1983 | &new_data.fn.function); |
| 1984 | /* Copies created here are never canonical. */ |
| 1985 | break; |
| 1986 | |
| 1987 | default: |
| 1988 | new_kind = INTERNALVAR_VALUE; |
| 1989 | new_data.value = value_copy (val); |
| 1990 | new_data.value->modifiable = 1; |
| 1991 | |
| 1992 | /* Force the value to be fetched from the target now, to avoid problems |
| 1993 | later when this internalvar is referenced and the target is gone or |
| 1994 | has changed. */ |
| 1995 | if (value_lazy (new_data.value)) |
| 1996 | value_fetch_lazy (new_data.value); |
| 1997 | |
| 1998 | /* Release the value from the value chain to prevent it from being |
| 1999 | deleted by free_all_values. From here on this function should not |
| 2000 | call error () until new_data is installed into the var->u to avoid |
| 2001 | leaking memory. */ |
| 2002 | release_value (new_data.value); |
| 2003 | break; |
| 2004 | } |
| 2005 | |
| 2006 | /* Clean up old contents. */ |
| 2007 | clear_internalvar (var); |
| 2008 | |
| 2009 | /* Switch over. */ |
| 2010 | var->kind = new_kind; |
| 2011 | var->u = new_data; |
| 2012 | /* End code which must not call error(). */ |
| 2013 | } |
| 2014 | |
| 2015 | void |
| 2016 | set_internalvar_integer (struct internalvar *var, LONGEST l) |
| 2017 | { |
| 2018 | /* Clean up old contents. */ |
| 2019 | clear_internalvar (var); |
| 2020 | |
| 2021 | var->kind = INTERNALVAR_INTEGER; |
| 2022 | var->u.integer.type = NULL; |
| 2023 | var->u.integer.val = l; |
| 2024 | } |
| 2025 | |
| 2026 | void |
| 2027 | set_internalvar_string (struct internalvar *var, const char *string) |
| 2028 | { |
| 2029 | /* Clean up old contents. */ |
| 2030 | clear_internalvar (var); |
| 2031 | |
| 2032 | var->kind = INTERNALVAR_STRING; |
| 2033 | var->u.string = xstrdup (string); |
| 2034 | } |
| 2035 | |
| 2036 | static void |
| 2037 | set_internalvar_function (struct internalvar *var, struct internal_function *f) |
| 2038 | { |
| 2039 | /* Clean up old contents. */ |
| 2040 | clear_internalvar (var); |
| 2041 | |
| 2042 | var->kind = INTERNALVAR_FUNCTION; |
| 2043 | var->u.fn.function = f; |
| 2044 | var->u.fn.canonical = 1; |
| 2045 | /* Variables installed here are always the canonical version. */ |
| 2046 | } |
| 2047 | |
| 2048 | void |
| 2049 | clear_internalvar (struct internalvar *var) |
| 2050 | { |
| 2051 | /* Clean up old contents. */ |
| 2052 | switch (var->kind) |
| 2053 | { |
| 2054 | case INTERNALVAR_VALUE: |
| 2055 | value_free (var->u.value); |
| 2056 | break; |
| 2057 | |
| 2058 | case INTERNALVAR_STRING: |
| 2059 | xfree (var->u.string); |
| 2060 | break; |
| 2061 | |
| 2062 | case INTERNALVAR_MAKE_VALUE: |
| 2063 | if (var->u.make_value.functions->destroy != NULL) |
| 2064 | var->u.make_value.functions->destroy (var->u.make_value.data); |
| 2065 | break; |
| 2066 | |
| 2067 | default: |
| 2068 | break; |
| 2069 | } |
| 2070 | |
| 2071 | /* Reset to void kind. */ |
| 2072 | var->kind = INTERNALVAR_VOID; |
| 2073 | } |
| 2074 | |
| 2075 | char * |
| 2076 | internalvar_name (struct internalvar *var) |
| 2077 | { |
| 2078 | return var->name; |
| 2079 | } |
| 2080 | |
| 2081 | static struct internal_function * |
| 2082 | create_internal_function (const char *name, |
| 2083 | internal_function_fn handler, void *cookie) |
| 2084 | { |
| 2085 | struct internal_function *ifn = XNEW (struct internal_function); |
| 2086 | |
| 2087 | ifn->name = xstrdup (name); |
| 2088 | ifn->handler = handler; |
| 2089 | ifn->cookie = cookie; |
| 2090 | return ifn; |
| 2091 | } |
| 2092 | |
| 2093 | char * |
| 2094 | value_internal_function_name (struct value *val) |
| 2095 | { |
| 2096 | struct internal_function *ifn; |
| 2097 | int result; |
| 2098 | |
| 2099 | gdb_assert (VALUE_LVAL (val) == lval_internalvar); |
| 2100 | result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn); |
| 2101 | gdb_assert (result); |
| 2102 | |
| 2103 | return ifn->name; |
| 2104 | } |
| 2105 | |
| 2106 | struct value * |
| 2107 | call_internal_function (struct gdbarch *gdbarch, |
| 2108 | const struct language_defn *language, |
| 2109 | struct value *func, int argc, struct value **argv) |
| 2110 | { |
| 2111 | struct internal_function *ifn; |
| 2112 | int result; |
| 2113 | |
| 2114 | gdb_assert (VALUE_LVAL (func) == lval_internalvar); |
| 2115 | result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn); |
| 2116 | gdb_assert (result); |
| 2117 | |
| 2118 | return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv); |
| 2119 | } |
| 2120 | |
| 2121 | /* The 'function' command. This does nothing -- it is just a |
| 2122 | placeholder to let "help function NAME" work. This is also used as |
| 2123 | the implementation of the sub-command that is created when |
| 2124 | registering an internal function. */ |
| 2125 | static void |
| 2126 | function_command (char *command, int from_tty) |
| 2127 | { |
| 2128 | /* Do nothing. */ |
| 2129 | } |
| 2130 | |
| 2131 | /* Clean up if an internal function's command is destroyed. */ |
| 2132 | static void |
| 2133 | function_destroyer (struct cmd_list_element *self, void *ignore) |
| 2134 | { |
| 2135 | xfree (self->name); |
| 2136 | xfree (self->doc); |
| 2137 | } |
| 2138 | |
| 2139 | /* Add a new internal function. NAME is the name of the function; DOC |
| 2140 | is a documentation string describing the function. HANDLER is |
| 2141 | called when the function is invoked. COOKIE is an arbitrary |
| 2142 | pointer which is passed to HANDLER and is intended for "user |
| 2143 | data". */ |
| 2144 | void |
| 2145 | add_internal_function (const char *name, const char *doc, |
| 2146 | internal_function_fn handler, void *cookie) |
| 2147 | { |
| 2148 | struct cmd_list_element *cmd; |
| 2149 | struct internal_function *ifn; |
| 2150 | struct internalvar *var = lookup_internalvar (name); |
| 2151 | |
| 2152 | ifn = create_internal_function (name, handler, cookie); |
| 2153 | set_internalvar_function (var, ifn); |
| 2154 | |
| 2155 | cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc, |
| 2156 | &functionlist); |
| 2157 | cmd->destroyer = function_destroyer; |
| 2158 | } |
| 2159 | |
| 2160 | /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to |
| 2161 | prevent cycles / duplicates. */ |
| 2162 | |
| 2163 | void |
| 2164 | preserve_one_value (struct value *value, struct objfile *objfile, |
| 2165 | htab_t copied_types) |
| 2166 | { |
| 2167 | if (TYPE_OBJFILE (value->type) == objfile) |
| 2168 | value->type = copy_type_recursive (objfile, value->type, copied_types); |
| 2169 | |
| 2170 | if (TYPE_OBJFILE (value->enclosing_type) == objfile) |
| 2171 | value->enclosing_type = copy_type_recursive (objfile, |
| 2172 | value->enclosing_type, |
| 2173 | copied_types); |
| 2174 | } |
| 2175 | |
| 2176 | /* Likewise for internal variable VAR. */ |
| 2177 | |
| 2178 | static void |
| 2179 | preserve_one_internalvar (struct internalvar *var, struct objfile *objfile, |
| 2180 | htab_t copied_types) |
| 2181 | { |
| 2182 | switch (var->kind) |
| 2183 | { |
| 2184 | case INTERNALVAR_INTEGER: |
| 2185 | if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile) |
| 2186 | var->u.integer.type |
| 2187 | = copy_type_recursive (objfile, var->u.integer.type, copied_types); |
| 2188 | break; |
| 2189 | |
| 2190 | case INTERNALVAR_VALUE: |
| 2191 | preserve_one_value (var->u.value, objfile, copied_types); |
| 2192 | break; |
| 2193 | } |
| 2194 | } |
| 2195 | |
| 2196 | /* Update the internal variables and value history when OBJFILE is |
| 2197 | discarded; we must copy the types out of the objfile. New global types |
| 2198 | will be created for every convenience variable which currently points to |
| 2199 | this objfile's types, and the convenience variables will be adjusted to |
| 2200 | use the new global types. */ |
| 2201 | |
| 2202 | void |
| 2203 | preserve_values (struct objfile *objfile) |
| 2204 | { |
| 2205 | htab_t copied_types; |
| 2206 | struct value_history_chunk *cur; |
| 2207 | struct internalvar *var; |
| 2208 | int i; |
| 2209 | |
| 2210 | /* Create the hash table. We allocate on the objfile's obstack, since |
| 2211 | it is soon to be deleted. */ |
| 2212 | copied_types = create_copied_types_hash (objfile); |
| 2213 | |
| 2214 | for (cur = value_history_chain; cur; cur = cur->next) |
| 2215 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) |
| 2216 | if (cur->values[i]) |
| 2217 | preserve_one_value (cur->values[i], objfile, copied_types); |
| 2218 | |
| 2219 | for (var = internalvars; var; var = var->next) |
| 2220 | preserve_one_internalvar (var, objfile, copied_types); |
| 2221 | |
| 2222 | preserve_python_values (objfile, copied_types); |
| 2223 | |
| 2224 | htab_delete (copied_types); |
| 2225 | } |
| 2226 | |
| 2227 | static void |
| 2228 | show_convenience (char *ignore, int from_tty) |
| 2229 | { |
| 2230 | struct gdbarch *gdbarch = get_current_arch (); |
| 2231 | struct internalvar *var; |
| 2232 | int varseen = 0; |
| 2233 | struct value_print_options opts; |
| 2234 | |
| 2235 | get_user_print_options (&opts); |
| 2236 | for (var = internalvars; var; var = var->next) |
| 2237 | { |
| 2238 | volatile struct gdb_exception ex; |
| 2239 | |
| 2240 | if (!varseen) |
| 2241 | { |
| 2242 | varseen = 1; |
| 2243 | } |
| 2244 | printf_filtered (("$%s = "), var->name); |
| 2245 | |
| 2246 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
| 2247 | { |
| 2248 | struct value *val; |
| 2249 | |
| 2250 | val = value_of_internalvar (gdbarch, var); |
| 2251 | value_print (val, gdb_stdout, &opts); |
| 2252 | } |
| 2253 | if (ex.reason < 0) |
| 2254 | fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message); |
| 2255 | printf_filtered (("\n")); |
| 2256 | } |
| 2257 | if (!varseen) |
| 2258 | printf_unfiltered (_("No debugger convenience variables now defined.\n" |
| 2259 | "Convenience variables have " |
| 2260 | "names starting with \"$\";\n" |
| 2261 | "use \"set\" as in \"set " |
| 2262 | "$foo = 5\" to define them.\n")); |
| 2263 | } |
| 2264 | \f |
| 2265 | /* Extract a value as a C number (either long or double). |
| 2266 | Knows how to convert fixed values to double, or |
| 2267 | floating values to long. |
| 2268 | Does not deallocate the value. */ |
| 2269 | |
| 2270 | LONGEST |
| 2271 | value_as_long (struct value *val) |
| 2272 | { |
| 2273 | /* This coerces arrays and functions, which is necessary (e.g. |
| 2274 | in disassemble_command). It also dereferences references, which |
| 2275 | I suspect is the most logical thing to do. */ |
| 2276 | val = coerce_array (val); |
| 2277 | return unpack_long (value_type (val), value_contents (val)); |
| 2278 | } |
| 2279 | |
| 2280 | DOUBLEST |
| 2281 | value_as_double (struct value *val) |
| 2282 | { |
| 2283 | DOUBLEST foo; |
| 2284 | int inv; |
| 2285 | |
| 2286 | foo = unpack_double (value_type (val), value_contents (val), &inv); |
| 2287 | if (inv) |
| 2288 | error (_("Invalid floating value found in program.")); |
| 2289 | return foo; |
| 2290 | } |
| 2291 | |
| 2292 | /* Extract a value as a C pointer. Does not deallocate the value. |
| 2293 | Note that val's type may not actually be a pointer; value_as_long |
| 2294 | handles all the cases. */ |
| 2295 | CORE_ADDR |
| 2296 | value_as_address (struct value *val) |
| 2297 | { |
| 2298 | struct gdbarch *gdbarch = get_type_arch (value_type (val)); |
| 2299 | |
| 2300 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 2301 | whether we want this to be true eventually. */ |
| 2302 | #if 0 |
| 2303 | /* gdbarch_addr_bits_remove is wrong if we are being called for a |
| 2304 | non-address (e.g. argument to "signal", "info break", etc.), or |
| 2305 | for pointers to char, in which the low bits *are* significant. */ |
| 2306 | return gdbarch_addr_bits_remove (gdbarch, value_as_long (val)); |
| 2307 | #else |
| 2308 | |
| 2309 | /* There are several targets (IA-64, PowerPC, and others) which |
| 2310 | don't represent pointers to functions as simply the address of |
| 2311 | the function's entry point. For example, on the IA-64, a |
| 2312 | function pointer points to a two-word descriptor, generated by |
| 2313 | the linker, which contains the function's entry point, and the |
| 2314 | value the IA-64 "global pointer" register should have --- to |
| 2315 | support position-independent code. The linker generates |
| 2316 | descriptors only for those functions whose addresses are taken. |
| 2317 | |
| 2318 | On such targets, it's difficult for GDB to convert an arbitrary |
| 2319 | function address into a function pointer; it has to either find |
| 2320 | an existing descriptor for that function, or call malloc and |
| 2321 | build its own. On some targets, it is impossible for GDB to |
| 2322 | build a descriptor at all: the descriptor must contain a jump |
| 2323 | instruction; data memory cannot be executed; and code memory |
| 2324 | cannot be modified. |
| 2325 | |
| 2326 | Upon entry to this function, if VAL is a value of type `function' |
| 2327 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then |
| 2328 | value_address (val) is the address of the function. This is what |
| 2329 | you'll get if you evaluate an expression like `main'. The call |
| 2330 | to COERCE_ARRAY below actually does all the usual unary |
| 2331 | conversions, which includes converting values of type `function' |
| 2332 | to `pointer to function'. This is the challenging conversion |
| 2333 | discussed above. Then, `unpack_long' will convert that pointer |
| 2334 | back into an address. |
| 2335 | |
| 2336 | So, suppose the user types `disassemble foo' on an architecture |
| 2337 | with a strange function pointer representation, on which GDB |
| 2338 | cannot build its own descriptors, and suppose further that `foo' |
| 2339 | has no linker-built descriptor. The address->pointer conversion |
| 2340 | will signal an error and prevent the command from running, even |
| 2341 | though the next step would have been to convert the pointer |
| 2342 | directly back into the same address. |
| 2343 | |
| 2344 | The following shortcut avoids this whole mess. If VAL is a |
| 2345 | function, just return its address directly. */ |
| 2346 | if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
| 2347 | || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) |
| 2348 | return value_address (val); |
| 2349 | |
| 2350 | val = coerce_array (val); |
| 2351 | |
| 2352 | /* Some architectures (e.g. Harvard), map instruction and data |
| 2353 | addresses onto a single large unified address space. For |
| 2354 | instance: An architecture may consider a large integer in the |
| 2355 | range 0x10000000 .. 0x1000ffff to already represent a data |
| 2356 | addresses (hence not need a pointer to address conversion) while |
| 2357 | a small integer would still need to be converted integer to |
| 2358 | pointer to address. Just assume such architectures handle all |
| 2359 | integer conversions in a single function. */ |
| 2360 | |
| 2361 | /* JimB writes: |
| 2362 | |
| 2363 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we |
| 2364 | must admonish GDB hackers to make sure its behavior matches the |
| 2365 | compiler's, whenever possible. |
| 2366 | |
| 2367 | In general, I think GDB should evaluate expressions the same way |
| 2368 | the compiler does. When the user copies an expression out of |
| 2369 | their source code and hands it to a `print' command, they should |
| 2370 | get the same value the compiler would have computed. Any |
| 2371 | deviation from this rule can cause major confusion and annoyance, |
| 2372 | and needs to be justified carefully. In other words, GDB doesn't |
| 2373 | really have the freedom to do these conversions in clever and |
| 2374 | useful ways. |
| 2375 | |
| 2376 | AndrewC pointed out that users aren't complaining about how GDB |
| 2377 | casts integers to pointers; they are complaining that they can't |
| 2378 | take an address from a disassembly listing and give it to `x/i'. |
| 2379 | This is certainly important. |
| 2380 | |
| 2381 | Adding an architecture method like integer_to_address() certainly |
| 2382 | makes it possible for GDB to "get it right" in all circumstances |
| 2383 | --- the target has complete control over how things get done, so |
| 2384 | people can Do The Right Thing for their target without breaking |
| 2385 | anyone else. The standard doesn't specify how integers get |
| 2386 | converted to pointers; usually, the ABI doesn't either, but |
| 2387 | ABI-specific code is a more reasonable place to handle it. */ |
| 2388 | |
| 2389 | if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
| 2390 | && TYPE_CODE (value_type (val)) != TYPE_CODE_REF |
| 2391 | && gdbarch_integer_to_address_p (gdbarch)) |
| 2392 | return gdbarch_integer_to_address (gdbarch, value_type (val), |
| 2393 | value_contents (val)); |
| 2394 | |
| 2395 | return unpack_long (value_type (val), value_contents (val)); |
| 2396 | #endif |
| 2397 | } |
| 2398 | \f |
| 2399 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 2400 | as a long, or as a double, assuming the raw data is described |
| 2401 | by type TYPE. Knows how to convert different sizes of values |
| 2402 | and can convert between fixed and floating point. We don't assume |
| 2403 | any alignment for the raw data. Return value is in host byte order. |
| 2404 | |
| 2405 | If you want functions and arrays to be coerced to pointers, and |
| 2406 | references to be dereferenced, call value_as_long() instead. |
| 2407 | |
| 2408 | C++: It is assumed that the front-end has taken care of |
| 2409 | all matters concerning pointers to members. A pointer |
| 2410 | to member which reaches here is considered to be equivalent |
| 2411 | to an INT (or some size). After all, it is only an offset. */ |
| 2412 | |
| 2413 | LONGEST |
| 2414 | unpack_long (struct type *type, const gdb_byte *valaddr) |
| 2415 | { |
| 2416 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 2417 | enum type_code code = TYPE_CODE (type); |
| 2418 | int len = TYPE_LENGTH (type); |
| 2419 | int nosign = TYPE_UNSIGNED (type); |
| 2420 | |
| 2421 | switch (code) |
| 2422 | { |
| 2423 | case TYPE_CODE_TYPEDEF: |
| 2424 | return unpack_long (check_typedef (type), valaddr); |
| 2425 | case TYPE_CODE_ENUM: |
| 2426 | case TYPE_CODE_FLAGS: |
| 2427 | case TYPE_CODE_BOOL: |
| 2428 | case TYPE_CODE_INT: |
| 2429 | case TYPE_CODE_CHAR: |
| 2430 | case TYPE_CODE_RANGE: |
| 2431 | case TYPE_CODE_MEMBERPTR: |
| 2432 | if (nosign) |
| 2433 | return extract_unsigned_integer (valaddr, len, byte_order); |
| 2434 | else |
| 2435 | return extract_signed_integer (valaddr, len, byte_order); |
| 2436 | |
| 2437 | case TYPE_CODE_FLT: |
| 2438 | return extract_typed_floating (valaddr, type); |
| 2439 | |
| 2440 | case TYPE_CODE_DECFLOAT: |
| 2441 | /* libdecnumber has a function to convert from decimal to integer, but |
| 2442 | it doesn't work when the decimal number has a fractional part. */ |
| 2443 | return decimal_to_doublest (valaddr, len, byte_order); |
| 2444 | |
| 2445 | case TYPE_CODE_PTR: |
| 2446 | case TYPE_CODE_REF: |
| 2447 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 2448 | whether we want this to be true eventually. */ |
| 2449 | return extract_typed_address (valaddr, type); |
| 2450 | |
| 2451 | default: |
| 2452 | error (_("Value can't be converted to integer.")); |
| 2453 | } |
| 2454 | return 0; /* Placate lint. */ |
| 2455 | } |
| 2456 | |
| 2457 | /* Return a double value from the specified type and address. |
| 2458 | INVP points to an int which is set to 0 for valid value, |
| 2459 | 1 for invalid value (bad float format). In either case, |
| 2460 | the returned double is OK to use. Argument is in target |
| 2461 | format, result is in host format. */ |
| 2462 | |
| 2463 | DOUBLEST |
| 2464 | unpack_double (struct type *type, const gdb_byte *valaddr, int *invp) |
| 2465 | { |
| 2466 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 2467 | enum type_code code; |
| 2468 | int len; |
| 2469 | int nosign; |
| 2470 | |
| 2471 | *invp = 0; /* Assume valid. */ |
| 2472 | CHECK_TYPEDEF (type); |
| 2473 | code = TYPE_CODE (type); |
| 2474 | len = TYPE_LENGTH (type); |
| 2475 | nosign = TYPE_UNSIGNED (type); |
| 2476 | if (code == TYPE_CODE_FLT) |
| 2477 | { |
| 2478 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
| 2479 | floating-point value was valid (using the macro |
| 2480 | INVALID_FLOAT). That test/macro have been removed. |
| 2481 | |
| 2482 | It turns out that only the VAX defined this macro and then |
| 2483 | only in a non-portable way. Fixing the portability problem |
| 2484 | wouldn't help since the VAX floating-point code is also badly |
| 2485 | bit-rotten. The target needs to add definitions for the |
| 2486 | methods gdbarch_float_format and gdbarch_double_format - these |
| 2487 | exactly describe the target floating-point format. The |
| 2488 | problem here is that the corresponding floatformat_vax_f and |
| 2489 | floatformat_vax_d values these methods should be set to are |
| 2490 | also not defined either. Oops! |
| 2491 | |
| 2492 | Hopefully someone will add both the missing floatformat |
| 2493 | definitions and the new cases for floatformat_is_valid (). */ |
| 2494 | |
| 2495 | if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) |
| 2496 | { |
| 2497 | *invp = 1; |
| 2498 | return 0.0; |
| 2499 | } |
| 2500 | |
| 2501 | return extract_typed_floating (valaddr, type); |
| 2502 | } |
| 2503 | else if (code == TYPE_CODE_DECFLOAT) |
| 2504 | return decimal_to_doublest (valaddr, len, byte_order); |
| 2505 | else if (nosign) |
| 2506 | { |
| 2507 | /* Unsigned -- be sure we compensate for signed LONGEST. */ |
| 2508 | return (ULONGEST) unpack_long (type, valaddr); |
| 2509 | } |
| 2510 | else |
| 2511 | { |
| 2512 | /* Signed -- we are OK with unpack_long. */ |
| 2513 | return unpack_long (type, valaddr); |
| 2514 | } |
| 2515 | } |
| 2516 | |
| 2517 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 2518 | as a CORE_ADDR, assuming the raw data is described by type TYPE. |
| 2519 | We don't assume any alignment for the raw data. Return value is in |
| 2520 | host byte order. |
| 2521 | |
| 2522 | If you want functions and arrays to be coerced to pointers, and |
| 2523 | references to be dereferenced, call value_as_address() instead. |
| 2524 | |
| 2525 | C++: It is assumed that the front-end has taken care of |
| 2526 | all matters concerning pointers to members. A pointer |
| 2527 | to member which reaches here is considered to be equivalent |
| 2528 | to an INT (or some size). After all, it is only an offset. */ |
| 2529 | |
| 2530 | CORE_ADDR |
| 2531 | unpack_pointer (struct type *type, const gdb_byte *valaddr) |
| 2532 | { |
| 2533 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 2534 | whether we want this to be true eventually. */ |
| 2535 | return unpack_long (type, valaddr); |
| 2536 | } |
| 2537 | |
| 2538 | \f |
| 2539 | /* Get the value of the FIELDNO'th field (which must be static) of |
| 2540 | TYPE. Return NULL if the field doesn't exist or has been |
| 2541 | optimized out. */ |
| 2542 | |
| 2543 | struct value * |
| 2544 | value_static_field (struct type *type, int fieldno) |
| 2545 | { |
| 2546 | struct value *retval; |
| 2547 | |
| 2548 | switch (TYPE_FIELD_LOC_KIND (type, fieldno)) |
| 2549 | { |
| 2550 | case FIELD_LOC_KIND_PHYSADDR: |
| 2551 | retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno), |
| 2552 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
| 2553 | break; |
| 2554 | case FIELD_LOC_KIND_PHYSNAME: |
| 2555 | { |
| 2556 | const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); |
| 2557 | /* TYPE_FIELD_NAME (type, fieldno); */ |
| 2558 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); |
| 2559 | |
| 2560 | if (sym == NULL) |
| 2561 | { |
| 2562 | /* With some compilers, e.g. HP aCC, static data members are |
| 2563 | reported as non-debuggable symbols. */ |
| 2564 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, |
| 2565 | NULL, NULL); |
| 2566 | |
| 2567 | if (!msym) |
| 2568 | return NULL; |
| 2569 | else |
| 2570 | { |
| 2571 | retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno), |
| 2572 | SYMBOL_VALUE_ADDRESS (msym)); |
| 2573 | } |
| 2574 | } |
| 2575 | else |
| 2576 | retval = value_of_variable (sym, NULL); |
| 2577 | break; |
| 2578 | } |
| 2579 | default: |
| 2580 | gdb_assert_not_reached ("unexpected field location kind"); |
| 2581 | } |
| 2582 | |
| 2583 | return retval; |
| 2584 | } |
| 2585 | |
| 2586 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
| 2587 | You have to be careful here, since the size of the data area for the value |
| 2588 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger |
| 2589 | than the old enclosing type, you have to allocate more space for the |
| 2590 | data. */ |
| 2591 | |
| 2592 | void |
| 2593 | set_value_enclosing_type (struct value *val, struct type *new_encl_type) |
| 2594 | { |
| 2595 | if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val))) |
| 2596 | val->contents = |
| 2597 | (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type)); |
| 2598 | |
| 2599 | val->enclosing_type = new_encl_type; |
| 2600 | } |
| 2601 | |
| 2602 | /* Given a value ARG1 (offset by OFFSET bytes) |
| 2603 | of a struct or union type ARG_TYPE, |
| 2604 | extract and return the value of one of its (non-static) fields. |
| 2605 | FIELDNO says which field. */ |
| 2606 | |
| 2607 | struct value * |
| 2608 | value_primitive_field (struct value *arg1, int offset, |
| 2609 | int fieldno, struct type *arg_type) |
| 2610 | { |
| 2611 | struct value *v; |
| 2612 | struct type *type; |
| 2613 | |
| 2614 | CHECK_TYPEDEF (arg_type); |
| 2615 | type = TYPE_FIELD_TYPE (arg_type, fieldno); |
| 2616 | |
| 2617 | /* Call check_typedef on our type to make sure that, if TYPE |
| 2618 | is a TYPE_CODE_TYPEDEF, its length is set to the length |
| 2619 | of the target type instead of zero. However, we do not |
| 2620 | replace the typedef type by the target type, because we want |
| 2621 | to keep the typedef in order to be able to print the type |
| 2622 | description correctly. */ |
| 2623 | check_typedef (type); |
| 2624 | |
| 2625 | if (value_optimized_out (arg1)) |
| 2626 | v = allocate_optimized_out_value (type); |
| 2627 | else if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) |
| 2628 | { |
| 2629 | /* Handle packed fields. |
| 2630 | |
| 2631 | Create a new value for the bitfield, with bitpos and bitsize |
| 2632 | set. If possible, arrange offset and bitpos so that we can |
| 2633 | do a single aligned read of the size of the containing type. |
| 2634 | Otherwise, adjust offset to the byte containing the first |
| 2635 | bit. Assume that the address, offset, and embedded offset |
| 2636 | are sufficiently aligned. */ |
| 2637 | |
| 2638 | int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno); |
| 2639 | int container_bitsize = TYPE_LENGTH (type) * 8; |
| 2640 | |
| 2641 | v = allocate_value_lazy (type); |
| 2642 | v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); |
| 2643 | if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize |
| 2644 | && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)) |
| 2645 | v->bitpos = bitpos % container_bitsize; |
| 2646 | else |
| 2647 | v->bitpos = bitpos % 8; |
| 2648 | v->offset = (value_embedded_offset (arg1) |
| 2649 | + offset |
| 2650 | + (bitpos - v->bitpos) / 8); |
| 2651 | v->parent = arg1; |
| 2652 | value_incref (v->parent); |
| 2653 | if (!value_lazy (arg1)) |
| 2654 | value_fetch_lazy (v); |
| 2655 | } |
| 2656 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) |
| 2657 | { |
| 2658 | /* This field is actually a base subobject, so preserve the |
| 2659 | entire object's contents for later references to virtual |
| 2660 | bases, etc. */ |
| 2661 | int boffset; |
| 2662 | |
| 2663 | /* Lazy register values with offsets are not supported. */ |
| 2664 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) |
| 2665 | value_fetch_lazy (arg1); |
| 2666 | |
| 2667 | /* We special case virtual inheritance here because this |
| 2668 | requires access to the contents, which we would rather avoid |
| 2669 | for references to ordinary fields of unavailable values. */ |
| 2670 | if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno)) |
| 2671 | boffset = baseclass_offset (arg_type, fieldno, |
| 2672 | value_contents (arg1), |
| 2673 | value_embedded_offset (arg1), |
| 2674 | value_address (arg1), |
| 2675 | arg1); |
| 2676 | else |
| 2677 | boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| 2678 | |
| 2679 | if (value_lazy (arg1)) |
| 2680 | v = allocate_value_lazy (value_enclosing_type (arg1)); |
| 2681 | else |
| 2682 | { |
| 2683 | v = allocate_value (value_enclosing_type (arg1)); |
| 2684 | value_contents_copy_raw (v, 0, arg1, 0, |
| 2685 | TYPE_LENGTH (value_enclosing_type (arg1))); |
| 2686 | } |
| 2687 | v->type = type; |
| 2688 | v->offset = value_offset (arg1); |
| 2689 | v->embedded_offset = offset + value_embedded_offset (arg1) + boffset; |
| 2690 | } |
| 2691 | else |
| 2692 | { |
| 2693 | /* Plain old data member */ |
| 2694 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| 2695 | |
| 2696 | /* Lazy register values with offsets are not supported. */ |
| 2697 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) |
| 2698 | value_fetch_lazy (arg1); |
| 2699 | |
| 2700 | if (value_lazy (arg1)) |
| 2701 | v = allocate_value_lazy (type); |
| 2702 | else |
| 2703 | { |
| 2704 | v = allocate_value (type); |
| 2705 | value_contents_copy_raw (v, value_embedded_offset (v), |
| 2706 | arg1, value_embedded_offset (arg1) + offset, |
| 2707 | TYPE_LENGTH (type)); |
| 2708 | } |
| 2709 | v->offset = (value_offset (arg1) + offset |
| 2710 | + value_embedded_offset (arg1)); |
| 2711 | } |
| 2712 | set_value_component_location (v, arg1); |
| 2713 | VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
| 2714 | VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
| 2715 | return v; |
| 2716 | } |
| 2717 | |
| 2718 | /* Given a value ARG1 of a struct or union type, |
| 2719 | extract and return the value of one of its (non-static) fields. |
| 2720 | FIELDNO says which field. */ |
| 2721 | |
| 2722 | struct value * |
| 2723 | value_field (struct value *arg1, int fieldno) |
| 2724 | { |
| 2725 | return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
| 2726 | } |
| 2727 | |
| 2728 | /* Return a non-virtual function as a value. |
| 2729 | F is the list of member functions which contains the desired method. |
| 2730 | J is an index into F which provides the desired method. |
| 2731 | |
| 2732 | We only use the symbol for its address, so be happy with either a |
| 2733 | full symbol or a minimal symbol. */ |
| 2734 | |
| 2735 | struct value * |
| 2736 | value_fn_field (struct value **arg1p, struct fn_field *f, |
| 2737 | int j, struct type *type, |
| 2738 | int offset) |
| 2739 | { |
| 2740 | struct value *v; |
| 2741 | struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
| 2742 | const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
| 2743 | struct symbol *sym; |
| 2744 | struct minimal_symbol *msym; |
| 2745 | |
| 2746 | sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0); |
| 2747 | if (sym != NULL) |
| 2748 | { |
| 2749 | msym = NULL; |
| 2750 | } |
| 2751 | else |
| 2752 | { |
| 2753 | gdb_assert (sym == NULL); |
| 2754 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
| 2755 | if (msym == NULL) |
| 2756 | return NULL; |
| 2757 | } |
| 2758 | |
| 2759 | v = allocate_value (ftype); |
| 2760 | if (sym) |
| 2761 | { |
| 2762 | set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym))); |
| 2763 | } |
| 2764 | else |
| 2765 | { |
| 2766 | /* The minimal symbol might point to a function descriptor; |
| 2767 | resolve it to the actual code address instead. */ |
| 2768 | struct objfile *objfile = msymbol_objfile (msym); |
| 2769 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 2770 | |
| 2771 | set_value_address (v, |
| 2772 | gdbarch_convert_from_func_ptr_addr |
| 2773 | (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target)); |
| 2774 | } |
| 2775 | |
| 2776 | if (arg1p) |
| 2777 | { |
| 2778 | if (type != value_type (*arg1p)) |
| 2779 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
| 2780 | value_addr (*arg1p))); |
| 2781 | |
| 2782 | /* Move the `this' pointer according to the offset. |
| 2783 | VALUE_OFFSET (*arg1p) += offset; */ |
| 2784 | } |
| 2785 | |
| 2786 | return v; |
| 2787 | } |
| 2788 | |
| 2789 | \f |
| 2790 | |
| 2791 | /* Helper function for both unpack_value_bits_as_long and |
| 2792 | unpack_bits_as_long. See those functions for more details on the |
| 2793 | interface; the only difference is that this function accepts either |
| 2794 | a NULL or a non-NULL ORIGINAL_VALUE. */ |
| 2795 | |
| 2796 | static int |
| 2797 | unpack_value_bits_as_long_1 (struct type *field_type, const gdb_byte *valaddr, |
| 2798 | int embedded_offset, int bitpos, int bitsize, |
| 2799 | const struct value *original_value, |
| 2800 | LONGEST *result) |
| 2801 | { |
| 2802 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type)); |
| 2803 | ULONGEST val; |
| 2804 | ULONGEST valmask; |
| 2805 | int lsbcount; |
| 2806 | int bytes_read; |
| 2807 | int read_offset; |
| 2808 | |
| 2809 | /* Read the minimum number of bytes required; there may not be |
| 2810 | enough bytes to read an entire ULONGEST. */ |
| 2811 | CHECK_TYPEDEF (field_type); |
| 2812 | if (bitsize) |
| 2813 | bytes_read = ((bitpos % 8) + bitsize + 7) / 8; |
| 2814 | else |
| 2815 | bytes_read = TYPE_LENGTH (field_type); |
| 2816 | |
| 2817 | read_offset = bitpos / 8; |
| 2818 | |
| 2819 | if (original_value != NULL |
| 2820 | && !value_bytes_available (original_value, embedded_offset + read_offset, |
| 2821 | bytes_read)) |
| 2822 | return 0; |
| 2823 | |
| 2824 | val = extract_unsigned_integer (valaddr + embedded_offset + read_offset, |
| 2825 | bytes_read, byte_order); |
| 2826 | |
| 2827 | /* Extract bits. See comment above. */ |
| 2828 | |
| 2829 | if (gdbarch_bits_big_endian (get_type_arch (field_type))) |
| 2830 | lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize); |
| 2831 | else |
| 2832 | lsbcount = (bitpos % 8); |
| 2833 | val >>= lsbcount; |
| 2834 | |
| 2835 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. |
| 2836 | If the field is signed, and is negative, then sign extend. */ |
| 2837 | |
| 2838 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) |
| 2839 | { |
| 2840 | valmask = (((ULONGEST) 1) << bitsize) - 1; |
| 2841 | val &= valmask; |
| 2842 | if (!TYPE_UNSIGNED (field_type)) |
| 2843 | { |
| 2844 | if (val & (valmask ^ (valmask >> 1))) |
| 2845 | { |
| 2846 | val |= ~valmask; |
| 2847 | } |
| 2848 | } |
| 2849 | } |
| 2850 | |
| 2851 | *result = val; |
| 2852 | return 1; |
| 2853 | } |
| 2854 | |
| 2855 | /* Unpack a bitfield of the specified FIELD_TYPE, from the object at |
| 2856 | VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT. |
| 2857 | VALADDR points to the contents of ORIGINAL_VALUE, which must not be |
| 2858 | NULL. The bitfield starts at BITPOS bits and contains BITSIZE |
| 2859 | bits. |
| 2860 | |
| 2861 | Returns false if the value contents are unavailable, otherwise |
| 2862 | returns true, indicating a valid value has been stored in *RESULT. |
| 2863 | |
| 2864 | Extracting bits depends on endianness of the machine. Compute the |
| 2865 | number of least significant bits to discard. For big endian machines, |
| 2866 | we compute the total number of bits in the anonymous object, subtract |
| 2867 | off the bit count from the MSB of the object to the MSB of the |
| 2868 | bitfield, then the size of the bitfield, which leaves the LSB discard |
| 2869 | count. For little endian machines, the discard count is simply the |
| 2870 | number of bits from the LSB of the anonymous object to the LSB of the |
| 2871 | bitfield. |
| 2872 | |
| 2873 | If the field is signed, we also do sign extension. */ |
| 2874 | |
| 2875 | int |
| 2876 | unpack_value_bits_as_long (struct type *field_type, const gdb_byte *valaddr, |
| 2877 | int embedded_offset, int bitpos, int bitsize, |
| 2878 | const struct value *original_value, |
| 2879 | LONGEST *result) |
| 2880 | { |
| 2881 | gdb_assert (original_value != NULL); |
| 2882 | |
| 2883 | return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset, |
| 2884 | bitpos, bitsize, original_value, result); |
| 2885 | |
| 2886 | } |
| 2887 | |
| 2888 | /* Unpack a field FIELDNO of the specified TYPE, from the object at |
| 2889 | VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of |
| 2890 | ORIGINAL_VALUE. See unpack_value_bits_as_long for more |
| 2891 | details. */ |
| 2892 | |
| 2893 | static int |
| 2894 | unpack_value_field_as_long_1 (struct type *type, const gdb_byte *valaddr, |
| 2895 | int embedded_offset, int fieldno, |
| 2896 | const struct value *val, LONGEST *result) |
| 2897 | { |
| 2898 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); |
| 2899 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); |
| 2900 | struct type *field_type = TYPE_FIELD_TYPE (type, fieldno); |
| 2901 | |
| 2902 | return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset, |
| 2903 | bitpos, bitsize, val, |
| 2904 | result); |
| 2905 | } |
| 2906 | |
| 2907 | /* Unpack a field FIELDNO of the specified TYPE, from the object at |
| 2908 | VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of |
| 2909 | ORIGINAL_VALUE, which must not be NULL. See |
| 2910 | unpack_value_bits_as_long for more details. */ |
| 2911 | |
| 2912 | int |
| 2913 | unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr, |
| 2914 | int embedded_offset, int fieldno, |
| 2915 | const struct value *val, LONGEST *result) |
| 2916 | { |
| 2917 | gdb_assert (val != NULL); |
| 2918 | |
| 2919 | return unpack_value_field_as_long_1 (type, valaddr, embedded_offset, |
| 2920 | fieldno, val, result); |
| 2921 | } |
| 2922 | |
| 2923 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous |
| 2924 | object at VALADDR. See unpack_value_bits_as_long for more details. |
| 2925 | This function differs from unpack_value_field_as_long in that it |
| 2926 | operates without a struct value object. */ |
| 2927 | |
| 2928 | LONGEST |
| 2929 | unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno) |
| 2930 | { |
| 2931 | LONGEST result; |
| 2932 | |
| 2933 | unpack_value_field_as_long_1 (type, valaddr, 0, fieldno, NULL, &result); |
| 2934 | return result; |
| 2935 | } |
| 2936 | |
| 2937 | /* Return a new value with type TYPE, which is FIELDNO field of the |
| 2938 | object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents |
| 2939 | of VAL. If the VAL's contents required to extract the bitfield |
| 2940 | from are unavailable, the new value is correspondingly marked as |
| 2941 | unavailable. */ |
| 2942 | |
| 2943 | struct value * |
| 2944 | value_field_bitfield (struct type *type, int fieldno, |
| 2945 | const gdb_byte *valaddr, |
| 2946 | int embedded_offset, const struct value *val) |
| 2947 | { |
| 2948 | LONGEST l; |
| 2949 | |
| 2950 | if (!unpack_value_field_as_long (type, valaddr, embedded_offset, fieldno, |
| 2951 | val, &l)) |
| 2952 | { |
| 2953 | struct type *field_type = TYPE_FIELD_TYPE (type, fieldno); |
| 2954 | struct value *retval = allocate_value (field_type); |
| 2955 | mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (field_type)); |
| 2956 | return retval; |
| 2957 | } |
| 2958 | else |
| 2959 | { |
| 2960 | return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), l); |
| 2961 | } |
| 2962 | } |
| 2963 | |
| 2964 | /* Modify the value of a bitfield. ADDR points to a block of memory in |
| 2965 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL |
| 2966 | is the desired value of the field, in host byte order. BITPOS and BITSIZE |
| 2967 | indicate which bits (in target bit order) comprise the bitfield. |
| 2968 | Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and |
| 2969 | 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ |
| 2970 | |
| 2971 | void |
| 2972 | modify_field (struct type *type, gdb_byte *addr, |
| 2973 | LONGEST fieldval, int bitpos, int bitsize) |
| 2974 | { |
| 2975 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 2976 | ULONGEST oword; |
| 2977 | ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); |
| 2978 | int bytesize; |
| 2979 | |
| 2980 | /* Normalize BITPOS. */ |
| 2981 | addr += bitpos / 8; |
| 2982 | bitpos %= 8; |
| 2983 | |
| 2984 | /* If a negative fieldval fits in the field in question, chop |
| 2985 | off the sign extension bits. */ |
| 2986 | if ((~fieldval & ~(mask >> 1)) == 0) |
| 2987 | fieldval &= mask; |
| 2988 | |
| 2989 | /* Warn if value is too big to fit in the field in question. */ |
| 2990 | if (0 != (fieldval & ~mask)) |
| 2991 | { |
| 2992 | /* FIXME: would like to include fieldval in the message, but |
| 2993 | we don't have a sprintf_longest. */ |
| 2994 | warning (_("Value does not fit in %d bits."), bitsize); |
| 2995 | |
| 2996 | /* Truncate it, otherwise adjoining fields may be corrupted. */ |
| 2997 | fieldval &= mask; |
| 2998 | } |
| 2999 | |
| 3000 | /* Ensure no bytes outside of the modified ones get accessed as it may cause |
| 3001 | false valgrind reports. */ |
| 3002 | |
| 3003 | bytesize = (bitpos + bitsize + 7) / 8; |
| 3004 | oword = extract_unsigned_integer (addr, bytesize, byte_order); |
| 3005 | |
| 3006 | /* Shifting for bit field depends on endianness of the target machine. */ |
| 3007 | if (gdbarch_bits_big_endian (get_type_arch (type))) |
| 3008 | bitpos = bytesize * 8 - bitpos - bitsize; |
| 3009 | |
| 3010 | oword &= ~(mask << bitpos); |
| 3011 | oword |= fieldval << bitpos; |
| 3012 | |
| 3013 | store_unsigned_integer (addr, bytesize, byte_order, oword); |
| 3014 | } |
| 3015 | \f |
| 3016 | /* Pack NUM into BUF using a target format of TYPE. */ |
| 3017 | |
| 3018 | void |
| 3019 | pack_long (gdb_byte *buf, struct type *type, LONGEST num) |
| 3020 | { |
| 3021 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 3022 | int len; |
| 3023 | |
| 3024 | type = check_typedef (type); |
| 3025 | len = TYPE_LENGTH (type); |
| 3026 | |
| 3027 | switch (TYPE_CODE (type)) |
| 3028 | { |
| 3029 | case TYPE_CODE_INT: |
| 3030 | case TYPE_CODE_CHAR: |
| 3031 | case TYPE_CODE_ENUM: |
| 3032 | case TYPE_CODE_FLAGS: |
| 3033 | case TYPE_CODE_BOOL: |
| 3034 | case TYPE_CODE_RANGE: |
| 3035 | case TYPE_CODE_MEMBERPTR: |
| 3036 | store_signed_integer (buf, len, byte_order, num); |
| 3037 | break; |
| 3038 | |
| 3039 | case TYPE_CODE_REF: |
| 3040 | case TYPE_CODE_PTR: |
| 3041 | store_typed_address (buf, type, (CORE_ADDR) num); |
| 3042 | break; |
| 3043 | |
| 3044 | default: |
| 3045 | error (_("Unexpected type (%d) encountered for integer constant."), |
| 3046 | TYPE_CODE (type)); |
| 3047 | } |
| 3048 | } |
| 3049 | |
| 3050 | |
| 3051 | /* Pack NUM into BUF using a target format of TYPE. */ |
| 3052 | |
| 3053 | static void |
| 3054 | pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num) |
| 3055 | { |
| 3056 | int len; |
| 3057 | enum bfd_endian byte_order; |
| 3058 | |
| 3059 | type = check_typedef (type); |
| 3060 | len = TYPE_LENGTH (type); |
| 3061 | byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 3062 | |
| 3063 | switch (TYPE_CODE (type)) |
| 3064 | { |
| 3065 | case TYPE_CODE_INT: |
| 3066 | case TYPE_CODE_CHAR: |
| 3067 | case TYPE_CODE_ENUM: |
| 3068 | case TYPE_CODE_FLAGS: |
| 3069 | case TYPE_CODE_BOOL: |
| 3070 | case TYPE_CODE_RANGE: |
| 3071 | case TYPE_CODE_MEMBERPTR: |
| 3072 | store_unsigned_integer (buf, len, byte_order, num); |
| 3073 | break; |
| 3074 | |
| 3075 | case TYPE_CODE_REF: |
| 3076 | case TYPE_CODE_PTR: |
| 3077 | store_typed_address (buf, type, (CORE_ADDR) num); |
| 3078 | break; |
| 3079 | |
| 3080 | default: |
| 3081 | error (_("Unexpected type (%d) encountered " |
| 3082 | "for unsigned integer constant."), |
| 3083 | TYPE_CODE (type)); |
| 3084 | } |
| 3085 | } |
| 3086 | |
| 3087 | |
| 3088 | /* Convert C numbers into newly allocated values. */ |
| 3089 | |
| 3090 | struct value * |
| 3091 | value_from_longest (struct type *type, LONGEST num) |
| 3092 | { |
| 3093 | struct value *val = allocate_value (type); |
| 3094 | |
| 3095 | pack_long (value_contents_raw (val), type, num); |
| 3096 | return val; |
| 3097 | } |
| 3098 | |
| 3099 | |
| 3100 | /* Convert C unsigned numbers into newly allocated values. */ |
| 3101 | |
| 3102 | struct value * |
| 3103 | value_from_ulongest (struct type *type, ULONGEST num) |
| 3104 | { |
| 3105 | struct value *val = allocate_value (type); |
| 3106 | |
| 3107 | pack_unsigned_long (value_contents_raw (val), type, num); |
| 3108 | |
| 3109 | return val; |
| 3110 | } |
| 3111 | |
| 3112 | |
| 3113 | /* Create a value representing a pointer of type TYPE to the address |
| 3114 | ADDR. */ |
| 3115 | struct value * |
| 3116 | value_from_pointer (struct type *type, CORE_ADDR addr) |
| 3117 | { |
| 3118 | struct value *val = allocate_value (type); |
| 3119 | |
| 3120 | store_typed_address (value_contents_raw (val), check_typedef (type), addr); |
| 3121 | return val; |
| 3122 | } |
| 3123 | |
| 3124 | |
| 3125 | /* Create a value of type TYPE whose contents come from VALADDR, if it |
| 3126 | is non-null, and whose memory address (in the inferior) is |
| 3127 | ADDRESS. */ |
| 3128 | |
| 3129 | struct value * |
| 3130 | value_from_contents_and_address (struct type *type, |
| 3131 | const gdb_byte *valaddr, |
| 3132 | CORE_ADDR address) |
| 3133 | { |
| 3134 | struct value *v; |
| 3135 | |
| 3136 | if (valaddr == NULL) |
| 3137 | v = allocate_value_lazy (type); |
| 3138 | else |
| 3139 | { |
| 3140 | v = allocate_value (type); |
| 3141 | memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type)); |
| 3142 | } |
| 3143 | set_value_address (v, address); |
| 3144 | VALUE_LVAL (v) = lval_memory; |
| 3145 | return v; |
| 3146 | } |
| 3147 | |
| 3148 | /* Create a value of type TYPE holding the contents CONTENTS. |
| 3149 | The new value is `not_lval'. */ |
| 3150 | |
| 3151 | struct value * |
| 3152 | value_from_contents (struct type *type, const gdb_byte *contents) |
| 3153 | { |
| 3154 | struct value *result; |
| 3155 | |
| 3156 | result = allocate_value (type); |
| 3157 | memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type)); |
| 3158 | return result; |
| 3159 | } |
| 3160 | |
| 3161 | struct value * |
| 3162 | value_from_double (struct type *type, DOUBLEST num) |
| 3163 | { |
| 3164 | struct value *val = allocate_value (type); |
| 3165 | struct type *base_type = check_typedef (type); |
| 3166 | enum type_code code = TYPE_CODE (base_type); |
| 3167 | |
| 3168 | if (code == TYPE_CODE_FLT) |
| 3169 | { |
| 3170 | store_typed_floating (value_contents_raw (val), base_type, num); |
| 3171 | } |
| 3172 | else |
| 3173 | error (_("Unexpected type encountered for floating constant.")); |
| 3174 | |
| 3175 | return val; |
| 3176 | } |
| 3177 | |
| 3178 | struct value * |
| 3179 | value_from_decfloat (struct type *type, const gdb_byte *dec) |
| 3180 | { |
| 3181 | struct value *val = allocate_value (type); |
| 3182 | |
| 3183 | memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type)); |
| 3184 | return val; |
| 3185 | } |
| 3186 | |
| 3187 | /* Extract a value from the history file. Input will be of the form |
| 3188 | $digits or $$digits. See block comment above 'write_dollar_variable' |
| 3189 | for details. */ |
| 3190 | |
| 3191 | struct value * |
| 3192 | value_from_history_ref (char *h, char **endp) |
| 3193 | { |
| 3194 | int index, len; |
| 3195 | |
| 3196 | if (h[0] == '$') |
| 3197 | len = 1; |
| 3198 | else |
| 3199 | return NULL; |
| 3200 | |
| 3201 | if (h[1] == '$') |
| 3202 | len = 2; |
| 3203 | |
| 3204 | /* Find length of numeral string. */ |
| 3205 | for (; isdigit (h[len]); len++) |
| 3206 | ; |
| 3207 | |
| 3208 | /* Make sure numeral string is not part of an identifier. */ |
| 3209 | if (h[len] == '_' || isalpha (h[len])) |
| 3210 | return NULL; |
| 3211 | |
| 3212 | /* Now collect the index value. */ |
| 3213 | if (h[1] == '$') |
| 3214 | { |
| 3215 | if (len == 2) |
| 3216 | { |
| 3217 | /* For some bizarre reason, "$$" is equivalent to "$$1", |
| 3218 | rather than to "$$0" as it ought to be! */ |
| 3219 | index = -1; |
| 3220 | *endp += len; |
| 3221 | } |
| 3222 | else |
| 3223 | index = -strtol (&h[2], endp, 10); |
| 3224 | } |
| 3225 | else |
| 3226 | { |
| 3227 | if (len == 1) |
| 3228 | { |
| 3229 | /* "$" is equivalent to "$0". */ |
| 3230 | index = 0; |
| 3231 | *endp += len; |
| 3232 | } |
| 3233 | else |
| 3234 | index = strtol (&h[1], endp, 10); |
| 3235 | } |
| 3236 | |
| 3237 | return access_value_history (index); |
| 3238 | } |
| 3239 | |
| 3240 | struct value * |
| 3241 | coerce_ref_if_computed (const struct value *arg) |
| 3242 | { |
| 3243 | const struct lval_funcs *funcs; |
| 3244 | |
| 3245 | if (TYPE_CODE (check_typedef (value_type (arg))) != TYPE_CODE_REF) |
| 3246 | return NULL; |
| 3247 | |
| 3248 | if (value_lval_const (arg) != lval_computed) |
| 3249 | return NULL; |
| 3250 | |
| 3251 | funcs = value_computed_funcs (arg); |
| 3252 | if (funcs->coerce_ref == NULL) |
| 3253 | return NULL; |
| 3254 | |
| 3255 | return funcs->coerce_ref (arg); |
| 3256 | } |
| 3257 | |
| 3258 | /* Look at value.h for description. */ |
| 3259 | |
| 3260 | struct value * |
| 3261 | readjust_indirect_value_type (struct value *value, struct type *enc_type, |
| 3262 | struct type *original_type, |
| 3263 | struct value *original_value) |
| 3264 | { |
| 3265 | /* Re-adjust type. */ |
| 3266 | deprecated_set_value_type (value, TYPE_TARGET_TYPE (original_type)); |
| 3267 | |
| 3268 | /* Add embedding info. */ |
| 3269 | set_value_enclosing_type (value, enc_type); |
| 3270 | set_value_embedded_offset (value, value_pointed_to_offset (original_value)); |
| 3271 | |
| 3272 | /* We may be pointing to an object of some derived type. */ |
| 3273 | return value_full_object (value, NULL, 0, 0, 0); |
| 3274 | } |
| 3275 | |
| 3276 | struct value * |
| 3277 | coerce_ref (struct value *arg) |
| 3278 | { |
| 3279 | struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
| 3280 | struct value *retval; |
| 3281 | struct type *enc_type; |
| 3282 | |
| 3283 | retval = coerce_ref_if_computed (arg); |
| 3284 | if (retval) |
| 3285 | return retval; |
| 3286 | |
| 3287 | if (TYPE_CODE (value_type_arg_tmp) != TYPE_CODE_REF) |
| 3288 | return arg; |
| 3289 | |
| 3290 | enc_type = check_typedef (value_enclosing_type (arg)); |
| 3291 | enc_type = TYPE_TARGET_TYPE (enc_type); |
| 3292 | |
| 3293 | retval = value_at_lazy (enc_type, |
| 3294 | unpack_pointer (value_type (arg), |
| 3295 | value_contents (arg))); |
| 3296 | return readjust_indirect_value_type (retval, enc_type, |
| 3297 | value_type_arg_tmp, arg); |
| 3298 | } |
| 3299 | |
| 3300 | struct value * |
| 3301 | coerce_array (struct value *arg) |
| 3302 | { |
| 3303 | struct type *type; |
| 3304 | |
| 3305 | arg = coerce_ref (arg); |
| 3306 | type = check_typedef (value_type (arg)); |
| 3307 | |
| 3308 | switch (TYPE_CODE (type)) |
| 3309 | { |
| 3310 | case TYPE_CODE_ARRAY: |
| 3311 | if (!TYPE_VECTOR (type) && current_language->c_style_arrays) |
| 3312 | arg = value_coerce_array (arg); |
| 3313 | break; |
| 3314 | case TYPE_CODE_FUNC: |
| 3315 | arg = value_coerce_function (arg); |
| 3316 | break; |
| 3317 | } |
| 3318 | return arg; |
| 3319 | } |
| 3320 | \f |
| 3321 | |
| 3322 | /* Return true if the function returning the specified type is using |
| 3323 | the convention of returning structures in memory (passing in the |
| 3324 | address as a hidden first parameter). */ |
| 3325 | |
| 3326 | int |
| 3327 | using_struct_return (struct gdbarch *gdbarch, |
| 3328 | struct value *function, struct type *value_type) |
| 3329 | { |
| 3330 | enum type_code code = TYPE_CODE (value_type); |
| 3331 | |
| 3332 | if (code == TYPE_CODE_ERROR) |
| 3333 | error (_("Function return type unknown.")); |
| 3334 | |
| 3335 | if (code == TYPE_CODE_VOID) |
| 3336 | /* A void return value is never in memory. See also corresponding |
| 3337 | code in "print_return_value". */ |
| 3338 | return 0; |
| 3339 | |
| 3340 | /* Probe the architecture for the return-value convention. */ |
| 3341 | return (gdbarch_return_value (gdbarch, function, value_type, |
| 3342 | NULL, NULL, NULL) |
| 3343 | != RETURN_VALUE_REGISTER_CONVENTION); |
| 3344 | } |
| 3345 | |
| 3346 | /* Set the initialized field in a value struct. */ |
| 3347 | |
| 3348 | void |
| 3349 | set_value_initialized (struct value *val, int status) |
| 3350 | { |
| 3351 | val->initialized = status; |
| 3352 | } |
| 3353 | |
| 3354 | /* Return the initialized field in a value struct. */ |
| 3355 | |
| 3356 | int |
| 3357 | value_initialized (struct value *val) |
| 3358 | { |
| 3359 | return val->initialized; |
| 3360 | } |
| 3361 | |
| 3362 | void |
| 3363 | _initialize_values (void) |
| 3364 | { |
| 3365 | add_cmd ("convenience", no_class, show_convenience, _("\ |
| 3366 | Debugger convenience (\"$foo\") variables.\n\ |
| 3367 | These variables are created when you assign them values;\n\ |
| 3368 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\ |
| 3369 | \n\ |
| 3370 | A few convenience variables are given values automatically:\n\ |
| 3371 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ |
| 3372 | \"$__\" holds the contents of the last address examined with \"x\"."), |
| 3373 | &showlist); |
| 3374 | |
| 3375 | add_cmd ("values", no_set_class, show_values, _("\ |
| 3376 | Elements of value history around item number IDX (or last ten)."), |
| 3377 | &showlist); |
| 3378 | |
| 3379 | add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\ |
| 3380 | Initialize a convenience variable if necessary.\n\ |
| 3381 | init-if-undefined VARIABLE = EXPRESSION\n\ |
| 3382 | Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\ |
| 3383 | exist or does not contain a value. The EXPRESSION is not evaluated if the\n\ |
| 3384 | VARIABLE is already initialized.")); |
| 3385 | |
| 3386 | add_prefix_cmd ("function", no_class, function_command, _("\ |
| 3387 | Placeholder command for showing help on convenience functions."), |
| 3388 | &functionlist, "function ", 0, &cmdlist); |
| 3389 | } |