| 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
| 2 | |
| 3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
| 4 | 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008, |
| 5 | 2009, 2010 Free Software Foundation, Inc. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "arch-utils.h" |
| 24 | #include "gdb_string.h" |
| 25 | #include "symtab.h" |
| 26 | #include "gdbtypes.h" |
| 27 | #include "value.h" |
| 28 | #include "gdbcore.h" |
| 29 | #include "command.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "target.h" |
| 32 | #include "language.h" |
| 33 | #include "demangle.h" |
| 34 | #include "doublest.h" |
| 35 | #include "gdb_assert.h" |
| 36 | #include "regcache.h" |
| 37 | #include "block.h" |
| 38 | #include "dfp.h" |
| 39 | #include "objfiles.h" |
| 40 | #include "valprint.h" |
| 41 | #include "cli/cli-decode.h" |
| 42 | |
| 43 | #include "python/python.h" |
| 44 | |
| 45 | /* Prototypes for exported functions. */ |
| 46 | |
| 47 | void _initialize_values (void); |
| 48 | |
| 49 | /* Definition of a user function. */ |
| 50 | struct internal_function |
| 51 | { |
| 52 | /* The name of the function. It is a bit odd to have this in the |
| 53 | function itself -- the user might use a differently-named |
| 54 | convenience variable to hold the function. */ |
| 55 | char *name; |
| 56 | |
| 57 | /* The handler. */ |
| 58 | internal_function_fn handler; |
| 59 | |
| 60 | /* User data for the handler. */ |
| 61 | void *cookie; |
| 62 | }; |
| 63 | |
| 64 | static struct cmd_list_element *functionlist; |
| 65 | |
| 66 | struct value |
| 67 | { |
| 68 | /* Type of value; either not an lval, or one of the various |
| 69 | different possible kinds of lval. */ |
| 70 | enum lval_type lval; |
| 71 | |
| 72 | /* Is it modifiable? Only relevant if lval != not_lval. */ |
| 73 | int modifiable; |
| 74 | |
| 75 | /* Location of value (if lval). */ |
| 76 | union |
| 77 | { |
| 78 | /* If lval == lval_memory, this is the address in the inferior. |
| 79 | If lval == lval_register, this is the byte offset into the |
| 80 | registers structure. */ |
| 81 | CORE_ADDR address; |
| 82 | |
| 83 | /* Pointer to internal variable. */ |
| 84 | struct internalvar *internalvar; |
| 85 | |
| 86 | /* If lval == lval_computed, this is a set of function pointers |
| 87 | to use to access and describe the value, and a closure pointer |
| 88 | for them to use. */ |
| 89 | struct |
| 90 | { |
| 91 | struct lval_funcs *funcs; /* Functions to call. */ |
| 92 | void *closure; /* Closure for those functions to use. */ |
| 93 | } computed; |
| 94 | } location; |
| 95 | |
| 96 | /* Describes offset of a value within lval of a structure in bytes. |
| 97 | If lval == lval_memory, this is an offset to the address. If |
| 98 | lval == lval_register, this is a further offset from |
| 99 | location.address within the registers structure. Note also the |
| 100 | member embedded_offset below. */ |
| 101 | int offset; |
| 102 | |
| 103 | /* Only used for bitfields; number of bits contained in them. */ |
| 104 | int bitsize; |
| 105 | |
| 106 | /* Only used for bitfields; position of start of field. For |
| 107 | gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For |
| 108 | gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */ |
| 109 | int bitpos; |
| 110 | |
| 111 | /* Only used for bitfields; the containing value. This allows a |
| 112 | single read from the target when displaying multiple |
| 113 | bitfields. */ |
| 114 | struct value *parent; |
| 115 | |
| 116 | /* Frame register value is relative to. This will be described in |
| 117 | the lval enum above as "lval_register". */ |
| 118 | struct frame_id frame_id; |
| 119 | |
| 120 | /* Type of the value. */ |
| 121 | struct type *type; |
| 122 | |
| 123 | /* If a value represents a C++ object, then the `type' field gives |
| 124 | the object's compile-time type. If the object actually belongs |
| 125 | to some class derived from `type', perhaps with other base |
| 126 | classes and additional members, then `type' is just a subobject |
| 127 | of the real thing, and the full object is probably larger than |
| 128 | `type' would suggest. |
| 129 | |
| 130 | If `type' is a dynamic class (i.e. one with a vtable), then GDB |
| 131 | can actually determine the object's run-time type by looking at |
| 132 | the run-time type information in the vtable. When this |
| 133 | information is available, we may elect to read in the entire |
| 134 | object, for several reasons: |
| 135 | |
| 136 | - When printing the value, the user would probably rather see the |
| 137 | full object, not just the limited portion apparent from the |
| 138 | compile-time type. |
| 139 | |
| 140 | - If `type' has virtual base classes, then even printing `type' |
| 141 | alone may require reaching outside the `type' portion of the |
| 142 | object to wherever the virtual base class has been stored. |
| 143 | |
| 144 | When we store the entire object, `enclosing_type' is the run-time |
| 145 | type -- the complete object -- and `embedded_offset' is the |
| 146 | offset of `type' within that larger type, in bytes. The |
| 147 | value_contents() macro takes `embedded_offset' into account, so |
| 148 | most GDB code continues to see the `type' portion of the value, |
| 149 | just as the inferior would. |
| 150 | |
| 151 | If `type' is a pointer to an object, then `enclosing_type' is a |
| 152 | pointer to the object's run-time type, and `pointed_to_offset' is |
| 153 | the offset in bytes from the full object to the pointed-to object |
| 154 | -- that is, the value `embedded_offset' would have if we followed |
| 155 | the pointer and fetched the complete object. (I don't really see |
| 156 | the point. Why not just determine the run-time type when you |
| 157 | indirect, and avoid the special case? The contents don't matter |
| 158 | until you indirect anyway.) |
| 159 | |
| 160 | If we're not doing anything fancy, `enclosing_type' is equal to |
| 161 | `type', and `embedded_offset' is zero, so everything works |
| 162 | normally. */ |
| 163 | struct type *enclosing_type; |
| 164 | int embedded_offset; |
| 165 | int pointed_to_offset; |
| 166 | |
| 167 | /* Values are stored in a chain, so that they can be deleted easily |
| 168 | over calls to the inferior. Values assigned to internal |
| 169 | variables, put into the value history or exposed to Python are |
| 170 | taken off this list. */ |
| 171 | struct value *next; |
| 172 | |
| 173 | /* Register number if the value is from a register. */ |
| 174 | short regnum; |
| 175 | |
| 176 | /* If zero, contents of this value are in the contents field. If |
| 177 | nonzero, contents are in inferior. If the lval field is lval_memory, |
| 178 | the contents are in inferior memory at location.address plus offset. |
| 179 | The lval field may also be lval_register. |
| 180 | |
| 181 | WARNING: This field is used by the code which handles watchpoints |
| 182 | (see breakpoint.c) to decide whether a particular value can be |
| 183 | watched by hardware watchpoints. If the lazy flag is set for |
| 184 | some member of a value chain, it is assumed that this member of |
| 185 | the chain doesn't need to be watched as part of watching the |
| 186 | value itself. This is how GDB avoids watching the entire struct |
| 187 | or array when the user wants to watch a single struct member or |
| 188 | array element. If you ever change the way lazy flag is set and |
| 189 | reset, be sure to consider this use as well! */ |
| 190 | char lazy; |
| 191 | |
| 192 | /* If nonzero, this is the value of a variable which does not |
| 193 | actually exist in the program. */ |
| 194 | char optimized_out; |
| 195 | |
| 196 | /* If value is a variable, is it initialized or not. */ |
| 197 | int initialized; |
| 198 | |
| 199 | /* If value is from the stack. If this is set, read_stack will be |
| 200 | used instead of read_memory to enable extra caching. */ |
| 201 | int stack; |
| 202 | |
| 203 | /* Actual contents of the value. Target byte-order. NULL or not |
| 204 | valid if lazy is nonzero. */ |
| 205 | gdb_byte *contents; |
| 206 | |
| 207 | /* The number of references to this value. When a value is created, |
| 208 | the value chain holds a reference, so REFERENCE_COUNT is 1. If |
| 209 | release_value is called, this value is removed from the chain but |
| 210 | the caller of release_value now has a reference to this value. |
| 211 | The caller must arrange for a call to value_free later. */ |
| 212 | int reference_count; |
| 213 | }; |
| 214 | |
| 215 | /* Prototypes for local functions. */ |
| 216 | |
| 217 | static void show_values (char *, int); |
| 218 | |
| 219 | static void show_convenience (char *, int); |
| 220 | |
| 221 | |
| 222 | /* The value-history records all the values printed |
| 223 | by print commands during this session. Each chunk |
| 224 | records 60 consecutive values. The first chunk on |
| 225 | the chain records the most recent values. |
| 226 | The total number of values is in value_history_count. */ |
| 227 | |
| 228 | #define VALUE_HISTORY_CHUNK 60 |
| 229 | |
| 230 | struct value_history_chunk |
| 231 | { |
| 232 | struct value_history_chunk *next; |
| 233 | struct value *values[VALUE_HISTORY_CHUNK]; |
| 234 | }; |
| 235 | |
| 236 | /* Chain of chunks now in use. */ |
| 237 | |
| 238 | static struct value_history_chunk *value_history_chain; |
| 239 | |
| 240 | static int value_history_count; /* Abs number of last entry stored */ |
| 241 | |
| 242 | \f |
| 243 | /* List of all value objects currently allocated |
| 244 | (except for those released by calls to release_value) |
| 245 | This is so they can be freed after each command. */ |
| 246 | |
| 247 | static struct value *all_values; |
| 248 | |
| 249 | /* Allocate a lazy value for type TYPE. Its actual content is |
| 250 | "lazily" allocated too: the content field of the return value is |
| 251 | NULL; it will be allocated when it is fetched from the target. */ |
| 252 | |
| 253 | struct value * |
| 254 | allocate_value_lazy (struct type *type) |
| 255 | { |
| 256 | struct value *val; |
| 257 | |
| 258 | /* Call check_typedef on our type to make sure that, if TYPE |
| 259 | is a TYPE_CODE_TYPEDEF, its length is set to the length |
| 260 | of the target type instead of zero. However, we do not |
| 261 | replace the typedef type by the target type, because we want |
| 262 | to keep the typedef in order to be able to set the VAL's type |
| 263 | description correctly. */ |
| 264 | check_typedef (type); |
| 265 | |
| 266 | val = (struct value *) xzalloc (sizeof (struct value)); |
| 267 | val->contents = NULL; |
| 268 | val->next = all_values; |
| 269 | all_values = val; |
| 270 | val->type = type; |
| 271 | val->enclosing_type = type; |
| 272 | VALUE_LVAL (val) = not_lval; |
| 273 | val->location.address = 0; |
| 274 | VALUE_FRAME_ID (val) = null_frame_id; |
| 275 | val->offset = 0; |
| 276 | val->bitpos = 0; |
| 277 | val->bitsize = 0; |
| 278 | VALUE_REGNUM (val) = -1; |
| 279 | val->lazy = 1; |
| 280 | val->optimized_out = 0; |
| 281 | val->embedded_offset = 0; |
| 282 | val->pointed_to_offset = 0; |
| 283 | val->modifiable = 1; |
| 284 | val->initialized = 1; /* Default to initialized. */ |
| 285 | |
| 286 | /* Values start out on the all_values chain. */ |
| 287 | val->reference_count = 1; |
| 288 | |
| 289 | return val; |
| 290 | } |
| 291 | |
| 292 | /* Allocate the contents of VAL if it has not been allocated yet. */ |
| 293 | |
| 294 | void |
| 295 | allocate_value_contents (struct value *val) |
| 296 | { |
| 297 | if (!val->contents) |
| 298 | val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type)); |
| 299 | } |
| 300 | |
| 301 | /* Allocate a value and its contents for type TYPE. */ |
| 302 | |
| 303 | struct value * |
| 304 | allocate_value (struct type *type) |
| 305 | { |
| 306 | struct value *val = allocate_value_lazy (type); |
| 307 | allocate_value_contents (val); |
| 308 | val->lazy = 0; |
| 309 | return val; |
| 310 | } |
| 311 | |
| 312 | /* Allocate a value that has the correct length |
| 313 | for COUNT repetitions of type TYPE. */ |
| 314 | |
| 315 | struct value * |
| 316 | allocate_repeat_value (struct type *type, int count) |
| 317 | { |
| 318 | int low_bound = current_language->string_lower_bound; /* ??? */ |
| 319 | /* FIXME-type-allocation: need a way to free this type when we are |
| 320 | done with it. */ |
| 321 | struct type *array_type |
| 322 | = lookup_array_range_type (type, low_bound, count + low_bound - 1); |
| 323 | return allocate_value (array_type); |
| 324 | } |
| 325 | |
| 326 | struct value * |
| 327 | allocate_computed_value (struct type *type, |
| 328 | struct lval_funcs *funcs, |
| 329 | void *closure) |
| 330 | { |
| 331 | struct value *v = allocate_value (type); |
| 332 | VALUE_LVAL (v) = lval_computed; |
| 333 | v->location.computed.funcs = funcs; |
| 334 | v->location.computed.closure = closure; |
| 335 | set_value_lazy (v, 1); |
| 336 | |
| 337 | return v; |
| 338 | } |
| 339 | |
| 340 | /* Accessor methods. */ |
| 341 | |
| 342 | struct value * |
| 343 | value_next (struct value *value) |
| 344 | { |
| 345 | return value->next; |
| 346 | } |
| 347 | |
| 348 | struct type * |
| 349 | value_type (struct value *value) |
| 350 | { |
| 351 | return value->type; |
| 352 | } |
| 353 | void |
| 354 | deprecated_set_value_type (struct value *value, struct type *type) |
| 355 | { |
| 356 | value->type = type; |
| 357 | } |
| 358 | |
| 359 | int |
| 360 | value_offset (struct value *value) |
| 361 | { |
| 362 | return value->offset; |
| 363 | } |
| 364 | void |
| 365 | set_value_offset (struct value *value, int offset) |
| 366 | { |
| 367 | value->offset = offset; |
| 368 | } |
| 369 | |
| 370 | int |
| 371 | value_bitpos (struct value *value) |
| 372 | { |
| 373 | return value->bitpos; |
| 374 | } |
| 375 | void |
| 376 | set_value_bitpos (struct value *value, int bit) |
| 377 | { |
| 378 | value->bitpos = bit; |
| 379 | } |
| 380 | |
| 381 | int |
| 382 | value_bitsize (struct value *value) |
| 383 | { |
| 384 | return value->bitsize; |
| 385 | } |
| 386 | void |
| 387 | set_value_bitsize (struct value *value, int bit) |
| 388 | { |
| 389 | value->bitsize = bit; |
| 390 | } |
| 391 | |
| 392 | struct value * |
| 393 | value_parent (struct value *value) |
| 394 | { |
| 395 | return value->parent; |
| 396 | } |
| 397 | |
| 398 | gdb_byte * |
| 399 | value_contents_raw (struct value *value) |
| 400 | { |
| 401 | allocate_value_contents (value); |
| 402 | return value->contents + value->embedded_offset; |
| 403 | } |
| 404 | |
| 405 | gdb_byte * |
| 406 | value_contents_all_raw (struct value *value) |
| 407 | { |
| 408 | allocate_value_contents (value); |
| 409 | return value->contents; |
| 410 | } |
| 411 | |
| 412 | struct type * |
| 413 | value_enclosing_type (struct value *value) |
| 414 | { |
| 415 | return value->enclosing_type; |
| 416 | } |
| 417 | |
| 418 | const gdb_byte * |
| 419 | value_contents_all (struct value *value) |
| 420 | { |
| 421 | if (value->lazy) |
| 422 | value_fetch_lazy (value); |
| 423 | return value->contents; |
| 424 | } |
| 425 | |
| 426 | int |
| 427 | value_lazy (struct value *value) |
| 428 | { |
| 429 | return value->lazy; |
| 430 | } |
| 431 | |
| 432 | void |
| 433 | set_value_lazy (struct value *value, int val) |
| 434 | { |
| 435 | value->lazy = val; |
| 436 | } |
| 437 | |
| 438 | int |
| 439 | value_stack (struct value *value) |
| 440 | { |
| 441 | return value->stack; |
| 442 | } |
| 443 | |
| 444 | void |
| 445 | set_value_stack (struct value *value, int val) |
| 446 | { |
| 447 | value->stack = val; |
| 448 | } |
| 449 | |
| 450 | const gdb_byte * |
| 451 | value_contents (struct value *value) |
| 452 | { |
| 453 | return value_contents_writeable (value); |
| 454 | } |
| 455 | |
| 456 | gdb_byte * |
| 457 | value_contents_writeable (struct value *value) |
| 458 | { |
| 459 | if (value->lazy) |
| 460 | value_fetch_lazy (value); |
| 461 | return value_contents_raw (value); |
| 462 | } |
| 463 | |
| 464 | /* Return non-zero if VAL1 and VAL2 have the same contents. Note that |
| 465 | this function is different from value_equal; in C the operator == |
| 466 | can return 0 even if the two values being compared are equal. */ |
| 467 | |
| 468 | int |
| 469 | value_contents_equal (struct value *val1, struct value *val2) |
| 470 | { |
| 471 | struct type *type1; |
| 472 | struct type *type2; |
| 473 | int len; |
| 474 | |
| 475 | type1 = check_typedef (value_type (val1)); |
| 476 | type2 = check_typedef (value_type (val2)); |
| 477 | len = TYPE_LENGTH (type1); |
| 478 | if (len != TYPE_LENGTH (type2)) |
| 479 | return 0; |
| 480 | |
| 481 | return (memcmp (value_contents (val1), value_contents (val2), len) == 0); |
| 482 | } |
| 483 | |
| 484 | int |
| 485 | value_optimized_out (struct value *value) |
| 486 | { |
| 487 | return value->optimized_out; |
| 488 | } |
| 489 | |
| 490 | void |
| 491 | set_value_optimized_out (struct value *value, int val) |
| 492 | { |
| 493 | value->optimized_out = val; |
| 494 | } |
| 495 | |
| 496 | int |
| 497 | value_embedded_offset (struct value *value) |
| 498 | { |
| 499 | return value->embedded_offset; |
| 500 | } |
| 501 | |
| 502 | void |
| 503 | set_value_embedded_offset (struct value *value, int val) |
| 504 | { |
| 505 | value->embedded_offset = val; |
| 506 | } |
| 507 | |
| 508 | int |
| 509 | value_pointed_to_offset (struct value *value) |
| 510 | { |
| 511 | return value->pointed_to_offset; |
| 512 | } |
| 513 | |
| 514 | void |
| 515 | set_value_pointed_to_offset (struct value *value, int val) |
| 516 | { |
| 517 | value->pointed_to_offset = val; |
| 518 | } |
| 519 | |
| 520 | struct lval_funcs * |
| 521 | value_computed_funcs (struct value *v) |
| 522 | { |
| 523 | gdb_assert (VALUE_LVAL (v) == lval_computed); |
| 524 | |
| 525 | return v->location.computed.funcs; |
| 526 | } |
| 527 | |
| 528 | void * |
| 529 | value_computed_closure (struct value *v) |
| 530 | { |
| 531 | gdb_assert (VALUE_LVAL (v) == lval_computed); |
| 532 | |
| 533 | return v->location.computed.closure; |
| 534 | } |
| 535 | |
| 536 | enum lval_type * |
| 537 | deprecated_value_lval_hack (struct value *value) |
| 538 | { |
| 539 | return &value->lval; |
| 540 | } |
| 541 | |
| 542 | CORE_ADDR |
| 543 | value_address (struct value *value) |
| 544 | { |
| 545 | if (value->lval == lval_internalvar |
| 546 | || value->lval == lval_internalvar_component) |
| 547 | return 0; |
| 548 | return value->location.address + value->offset; |
| 549 | } |
| 550 | |
| 551 | CORE_ADDR |
| 552 | value_raw_address (struct value *value) |
| 553 | { |
| 554 | if (value->lval == lval_internalvar |
| 555 | || value->lval == lval_internalvar_component) |
| 556 | return 0; |
| 557 | return value->location.address; |
| 558 | } |
| 559 | |
| 560 | void |
| 561 | set_value_address (struct value *value, CORE_ADDR addr) |
| 562 | { |
| 563 | gdb_assert (value->lval != lval_internalvar |
| 564 | && value->lval != lval_internalvar_component); |
| 565 | value->location.address = addr; |
| 566 | } |
| 567 | |
| 568 | struct internalvar ** |
| 569 | deprecated_value_internalvar_hack (struct value *value) |
| 570 | { |
| 571 | return &value->location.internalvar; |
| 572 | } |
| 573 | |
| 574 | struct frame_id * |
| 575 | deprecated_value_frame_id_hack (struct value *value) |
| 576 | { |
| 577 | return &value->frame_id; |
| 578 | } |
| 579 | |
| 580 | short * |
| 581 | deprecated_value_regnum_hack (struct value *value) |
| 582 | { |
| 583 | return &value->regnum; |
| 584 | } |
| 585 | |
| 586 | int |
| 587 | deprecated_value_modifiable (struct value *value) |
| 588 | { |
| 589 | return value->modifiable; |
| 590 | } |
| 591 | void |
| 592 | deprecated_set_value_modifiable (struct value *value, int modifiable) |
| 593 | { |
| 594 | value->modifiable = modifiable; |
| 595 | } |
| 596 | \f |
| 597 | /* Return a mark in the value chain. All values allocated after the |
| 598 | mark is obtained (except for those released) are subject to being freed |
| 599 | if a subsequent value_free_to_mark is passed the mark. */ |
| 600 | struct value * |
| 601 | value_mark (void) |
| 602 | { |
| 603 | return all_values; |
| 604 | } |
| 605 | |
| 606 | /* Take a reference to VAL. VAL will not be deallocated until all |
| 607 | references are released. */ |
| 608 | |
| 609 | void |
| 610 | value_incref (struct value *val) |
| 611 | { |
| 612 | val->reference_count++; |
| 613 | } |
| 614 | |
| 615 | /* Release a reference to VAL, which was acquired with value_incref. |
| 616 | This function is also called to deallocate values from the value |
| 617 | chain. */ |
| 618 | |
| 619 | void |
| 620 | value_free (struct value *val) |
| 621 | { |
| 622 | if (val) |
| 623 | { |
| 624 | gdb_assert (val->reference_count > 0); |
| 625 | val->reference_count--; |
| 626 | if (val->reference_count > 0) |
| 627 | return; |
| 628 | |
| 629 | /* If there's an associated parent value, drop our reference to |
| 630 | it. */ |
| 631 | if (val->parent != NULL) |
| 632 | value_free (val->parent); |
| 633 | |
| 634 | if (VALUE_LVAL (val) == lval_computed) |
| 635 | { |
| 636 | struct lval_funcs *funcs = val->location.computed.funcs; |
| 637 | |
| 638 | if (funcs->free_closure) |
| 639 | funcs->free_closure (val); |
| 640 | } |
| 641 | |
| 642 | xfree (val->contents); |
| 643 | } |
| 644 | xfree (val); |
| 645 | } |
| 646 | |
| 647 | /* Free all values allocated since MARK was obtained by value_mark |
| 648 | (except for those released). */ |
| 649 | void |
| 650 | value_free_to_mark (struct value *mark) |
| 651 | { |
| 652 | struct value *val; |
| 653 | struct value *next; |
| 654 | |
| 655 | for (val = all_values; val && val != mark; val = next) |
| 656 | { |
| 657 | next = val->next; |
| 658 | value_free (val); |
| 659 | } |
| 660 | all_values = val; |
| 661 | } |
| 662 | |
| 663 | /* Free all the values that have been allocated (except for those released). |
| 664 | Call after each command, successful or not. |
| 665 | In practice this is called before each command, which is sufficient. */ |
| 666 | |
| 667 | void |
| 668 | free_all_values (void) |
| 669 | { |
| 670 | struct value *val; |
| 671 | struct value *next; |
| 672 | |
| 673 | for (val = all_values; val; val = next) |
| 674 | { |
| 675 | next = val->next; |
| 676 | value_free (val); |
| 677 | } |
| 678 | |
| 679 | all_values = 0; |
| 680 | } |
| 681 | |
| 682 | /* Remove VAL from the chain all_values |
| 683 | so it will not be freed automatically. */ |
| 684 | |
| 685 | void |
| 686 | release_value (struct value *val) |
| 687 | { |
| 688 | struct value *v; |
| 689 | |
| 690 | if (all_values == val) |
| 691 | { |
| 692 | all_values = val->next; |
| 693 | return; |
| 694 | } |
| 695 | |
| 696 | for (v = all_values; v; v = v->next) |
| 697 | { |
| 698 | if (v->next == val) |
| 699 | { |
| 700 | v->next = val->next; |
| 701 | break; |
| 702 | } |
| 703 | } |
| 704 | } |
| 705 | |
| 706 | /* Release all values up to mark */ |
| 707 | struct value * |
| 708 | value_release_to_mark (struct value *mark) |
| 709 | { |
| 710 | struct value *val; |
| 711 | struct value *next; |
| 712 | |
| 713 | for (val = next = all_values; next; next = next->next) |
| 714 | if (next->next == mark) |
| 715 | { |
| 716 | all_values = next->next; |
| 717 | next->next = NULL; |
| 718 | return val; |
| 719 | } |
| 720 | all_values = 0; |
| 721 | return val; |
| 722 | } |
| 723 | |
| 724 | /* Return a copy of the value ARG. |
| 725 | It contains the same contents, for same memory address, |
| 726 | but it's a different block of storage. */ |
| 727 | |
| 728 | struct value * |
| 729 | value_copy (struct value *arg) |
| 730 | { |
| 731 | struct type *encl_type = value_enclosing_type (arg); |
| 732 | struct value *val; |
| 733 | |
| 734 | if (value_lazy (arg)) |
| 735 | val = allocate_value_lazy (encl_type); |
| 736 | else |
| 737 | val = allocate_value (encl_type); |
| 738 | val->type = arg->type; |
| 739 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
| 740 | val->location = arg->location; |
| 741 | val->offset = arg->offset; |
| 742 | val->bitpos = arg->bitpos; |
| 743 | val->bitsize = arg->bitsize; |
| 744 | VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg); |
| 745 | VALUE_REGNUM (val) = VALUE_REGNUM (arg); |
| 746 | val->lazy = arg->lazy; |
| 747 | val->optimized_out = arg->optimized_out; |
| 748 | val->embedded_offset = value_embedded_offset (arg); |
| 749 | val->pointed_to_offset = arg->pointed_to_offset; |
| 750 | val->modifiable = arg->modifiable; |
| 751 | if (!value_lazy (val)) |
| 752 | { |
| 753 | memcpy (value_contents_all_raw (val), value_contents_all_raw (arg), |
| 754 | TYPE_LENGTH (value_enclosing_type (arg))); |
| 755 | |
| 756 | } |
| 757 | val->parent = arg->parent; |
| 758 | if (val->parent) |
| 759 | value_incref (val->parent); |
| 760 | if (VALUE_LVAL (val) == lval_computed) |
| 761 | { |
| 762 | struct lval_funcs *funcs = val->location.computed.funcs; |
| 763 | |
| 764 | if (funcs->copy_closure) |
| 765 | val->location.computed.closure = funcs->copy_closure (val); |
| 766 | } |
| 767 | return val; |
| 768 | } |
| 769 | |
| 770 | void |
| 771 | set_value_component_location (struct value *component, struct value *whole) |
| 772 | { |
| 773 | if (VALUE_LVAL (whole) == lval_internalvar) |
| 774 | VALUE_LVAL (component) = lval_internalvar_component; |
| 775 | else |
| 776 | VALUE_LVAL (component) = VALUE_LVAL (whole); |
| 777 | |
| 778 | component->location = whole->location; |
| 779 | if (VALUE_LVAL (whole) == lval_computed) |
| 780 | { |
| 781 | struct lval_funcs *funcs = whole->location.computed.funcs; |
| 782 | |
| 783 | if (funcs->copy_closure) |
| 784 | component->location.computed.closure = funcs->copy_closure (whole); |
| 785 | } |
| 786 | } |
| 787 | |
| 788 | \f |
| 789 | /* Access to the value history. */ |
| 790 | |
| 791 | /* Record a new value in the value history. |
| 792 | Returns the absolute history index of the entry. |
| 793 | Result of -1 indicates the value was not saved; otherwise it is the |
| 794 | value history index of this new item. */ |
| 795 | |
| 796 | int |
| 797 | record_latest_value (struct value *val) |
| 798 | { |
| 799 | int i; |
| 800 | |
| 801 | /* We don't want this value to have anything to do with the inferior anymore. |
| 802 | In particular, "set $1 = 50" should not affect the variable from which |
| 803 | the value was taken, and fast watchpoints should be able to assume that |
| 804 | a value on the value history never changes. */ |
| 805 | if (value_lazy (val)) |
| 806 | value_fetch_lazy (val); |
| 807 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched |
| 808 | from. This is a bit dubious, because then *&$1 does not just return $1 |
| 809 | but the current contents of that location. c'est la vie... */ |
| 810 | val->modifiable = 0; |
| 811 | release_value (val); |
| 812 | |
| 813 | /* Here we treat value_history_count as origin-zero |
| 814 | and applying to the value being stored now. */ |
| 815 | |
| 816 | i = value_history_count % VALUE_HISTORY_CHUNK; |
| 817 | if (i == 0) |
| 818 | { |
| 819 | struct value_history_chunk *new |
| 820 | = (struct value_history_chunk *) |
| 821 | xmalloc (sizeof (struct value_history_chunk)); |
| 822 | memset (new->values, 0, sizeof new->values); |
| 823 | new->next = value_history_chain; |
| 824 | value_history_chain = new; |
| 825 | } |
| 826 | |
| 827 | value_history_chain->values[i] = val; |
| 828 | |
| 829 | /* Now we regard value_history_count as origin-one |
| 830 | and applying to the value just stored. */ |
| 831 | |
| 832 | return ++value_history_count; |
| 833 | } |
| 834 | |
| 835 | /* Return a copy of the value in the history with sequence number NUM. */ |
| 836 | |
| 837 | struct value * |
| 838 | access_value_history (int num) |
| 839 | { |
| 840 | struct value_history_chunk *chunk; |
| 841 | int i; |
| 842 | int absnum = num; |
| 843 | |
| 844 | if (absnum <= 0) |
| 845 | absnum += value_history_count; |
| 846 | |
| 847 | if (absnum <= 0) |
| 848 | { |
| 849 | if (num == 0) |
| 850 | error (_("The history is empty.")); |
| 851 | else if (num == 1) |
| 852 | error (_("There is only one value in the history.")); |
| 853 | else |
| 854 | error (_("History does not go back to $$%d."), -num); |
| 855 | } |
| 856 | if (absnum > value_history_count) |
| 857 | error (_("History has not yet reached $%d."), absnum); |
| 858 | |
| 859 | absnum--; |
| 860 | |
| 861 | /* Now absnum is always absolute and origin zero. */ |
| 862 | |
| 863 | chunk = value_history_chain; |
| 864 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; |
| 865 | i > 0; i--) |
| 866 | chunk = chunk->next; |
| 867 | |
| 868 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); |
| 869 | } |
| 870 | |
| 871 | static void |
| 872 | show_values (char *num_exp, int from_tty) |
| 873 | { |
| 874 | int i; |
| 875 | struct value *val; |
| 876 | static int num = 1; |
| 877 | |
| 878 | if (num_exp) |
| 879 | { |
| 880 | /* "show values +" should print from the stored position. |
| 881 | "show values <exp>" should print around value number <exp>. */ |
| 882 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
| 883 | num = parse_and_eval_long (num_exp) - 5; |
| 884 | } |
| 885 | else |
| 886 | { |
| 887 | /* "show values" means print the last 10 values. */ |
| 888 | num = value_history_count - 9; |
| 889 | } |
| 890 | |
| 891 | if (num <= 0) |
| 892 | num = 1; |
| 893 | |
| 894 | for (i = num; i < num + 10 && i <= value_history_count; i++) |
| 895 | { |
| 896 | struct value_print_options opts; |
| 897 | val = access_value_history (i); |
| 898 | printf_filtered (("$%d = "), i); |
| 899 | get_user_print_options (&opts); |
| 900 | value_print (val, gdb_stdout, &opts); |
| 901 | printf_filtered (("\n")); |
| 902 | } |
| 903 | |
| 904 | /* The next "show values +" should start after what we just printed. */ |
| 905 | num += 10; |
| 906 | |
| 907 | /* Hitting just return after this command should do the same thing as |
| 908 | "show values +". If num_exp is null, this is unnecessary, since |
| 909 | "show values +" is not useful after "show values". */ |
| 910 | if (from_tty && num_exp) |
| 911 | { |
| 912 | num_exp[0] = '+'; |
| 913 | num_exp[1] = '\0'; |
| 914 | } |
| 915 | } |
| 916 | \f |
| 917 | /* Internal variables. These are variables within the debugger |
| 918 | that hold values assigned by debugger commands. |
| 919 | The user refers to them with a '$' prefix |
| 920 | that does not appear in the variable names stored internally. */ |
| 921 | |
| 922 | struct internalvar |
| 923 | { |
| 924 | struct internalvar *next; |
| 925 | char *name; |
| 926 | |
| 927 | /* We support various different kinds of content of an internal variable. |
| 928 | enum internalvar_kind specifies the kind, and union internalvar_data |
| 929 | provides the data associated with this particular kind. */ |
| 930 | |
| 931 | enum internalvar_kind |
| 932 | { |
| 933 | /* The internal variable is empty. */ |
| 934 | INTERNALVAR_VOID, |
| 935 | |
| 936 | /* The value of the internal variable is provided directly as |
| 937 | a GDB value object. */ |
| 938 | INTERNALVAR_VALUE, |
| 939 | |
| 940 | /* A fresh value is computed via a call-back routine on every |
| 941 | access to the internal variable. */ |
| 942 | INTERNALVAR_MAKE_VALUE, |
| 943 | |
| 944 | /* The internal variable holds a GDB internal convenience function. */ |
| 945 | INTERNALVAR_FUNCTION, |
| 946 | |
| 947 | /* The variable holds an integer value. */ |
| 948 | INTERNALVAR_INTEGER, |
| 949 | |
| 950 | /* The variable holds a pointer value. */ |
| 951 | INTERNALVAR_POINTER, |
| 952 | |
| 953 | /* The variable holds a GDB-provided string. */ |
| 954 | INTERNALVAR_STRING, |
| 955 | |
| 956 | } kind; |
| 957 | |
| 958 | union internalvar_data |
| 959 | { |
| 960 | /* A value object used with INTERNALVAR_VALUE. */ |
| 961 | struct value *value; |
| 962 | |
| 963 | /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */ |
| 964 | internalvar_make_value make_value; |
| 965 | |
| 966 | /* The internal function used with INTERNALVAR_FUNCTION. */ |
| 967 | struct |
| 968 | { |
| 969 | struct internal_function *function; |
| 970 | /* True if this is the canonical name for the function. */ |
| 971 | int canonical; |
| 972 | } fn; |
| 973 | |
| 974 | /* An integer value used with INTERNALVAR_INTEGER. */ |
| 975 | struct |
| 976 | { |
| 977 | /* If type is non-NULL, it will be used as the type to generate |
| 978 | a value for this internal variable. If type is NULL, a default |
| 979 | integer type for the architecture is used. */ |
| 980 | struct type *type; |
| 981 | LONGEST val; |
| 982 | } integer; |
| 983 | |
| 984 | /* A pointer value used with INTERNALVAR_POINTER. */ |
| 985 | struct |
| 986 | { |
| 987 | struct type *type; |
| 988 | CORE_ADDR val; |
| 989 | } pointer; |
| 990 | |
| 991 | /* A string value used with INTERNALVAR_STRING. */ |
| 992 | char *string; |
| 993 | } u; |
| 994 | }; |
| 995 | |
| 996 | static struct internalvar *internalvars; |
| 997 | |
| 998 | /* If the variable does not already exist create it and give it the value given. |
| 999 | If no value is given then the default is zero. */ |
| 1000 | static void |
| 1001 | init_if_undefined_command (char* args, int from_tty) |
| 1002 | { |
| 1003 | struct internalvar* intvar; |
| 1004 | |
| 1005 | /* Parse the expression - this is taken from set_command(). */ |
| 1006 | struct expression *expr = parse_expression (args); |
| 1007 | register struct cleanup *old_chain = |
| 1008 | make_cleanup (free_current_contents, &expr); |
| 1009 | |
| 1010 | /* Validate the expression. |
| 1011 | Was the expression an assignment? |
| 1012 | Or even an expression at all? */ |
| 1013 | if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN) |
| 1014 | error (_("Init-if-undefined requires an assignment expression.")); |
| 1015 | |
| 1016 | /* Extract the variable from the parsed expression. |
| 1017 | In the case of an assign the lvalue will be in elts[1] and elts[2]. */ |
| 1018 | if (expr->elts[1].opcode != OP_INTERNALVAR) |
| 1019 | error (_("The first parameter to init-if-undefined should be a GDB variable.")); |
| 1020 | intvar = expr->elts[2].internalvar; |
| 1021 | |
| 1022 | /* Only evaluate the expression if the lvalue is void. |
| 1023 | This may still fail if the expresssion is invalid. */ |
| 1024 | if (intvar->kind == INTERNALVAR_VOID) |
| 1025 | evaluate_expression (expr); |
| 1026 | |
| 1027 | do_cleanups (old_chain); |
| 1028 | } |
| 1029 | |
| 1030 | |
| 1031 | /* Look up an internal variable with name NAME. NAME should not |
| 1032 | normally include a dollar sign. |
| 1033 | |
| 1034 | If the specified internal variable does not exist, |
| 1035 | the return value is NULL. */ |
| 1036 | |
| 1037 | struct internalvar * |
| 1038 | lookup_only_internalvar (const char *name) |
| 1039 | { |
| 1040 | struct internalvar *var; |
| 1041 | |
| 1042 | for (var = internalvars; var; var = var->next) |
| 1043 | if (strcmp (var->name, name) == 0) |
| 1044 | return var; |
| 1045 | |
| 1046 | return NULL; |
| 1047 | } |
| 1048 | |
| 1049 | |
| 1050 | /* Create an internal variable with name NAME and with a void value. |
| 1051 | NAME should not normally include a dollar sign. */ |
| 1052 | |
| 1053 | struct internalvar * |
| 1054 | create_internalvar (const char *name) |
| 1055 | { |
| 1056 | struct internalvar *var; |
| 1057 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
| 1058 | var->name = concat (name, (char *)NULL); |
| 1059 | var->kind = INTERNALVAR_VOID; |
| 1060 | var->next = internalvars; |
| 1061 | internalvars = var; |
| 1062 | return var; |
| 1063 | } |
| 1064 | |
| 1065 | /* Create an internal variable with name NAME and register FUN as the |
| 1066 | function that value_of_internalvar uses to create a value whenever |
| 1067 | this variable is referenced. NAME should not normally include a |
| 1068 | dollar sign. */ |
| 1069 | |
| 1070 | struct internalvar * |
| 1071 | create_internalvar_type_lazy (char *name, internalvar_make_value fun) |
| 1072 | { |
| 1073 | struct internalvar *var = create_internalvar (name); |
| 1074 | var->kind = INTERNALVAR_MAKE_VALUE; |
| 1075 | var->u.make_value = fun; |
| 1076 | return var; |
| 1077 | } |
| 1078 | |
| 1079 | /* Look up an internal variable with name NAME. NAME should not |
| 1080 | normally include a dollar sign. |
| 1081 | |
| 1082 | If the specified internal variable does not exist, |
| 1083 | one is created, with a void value. */ |
| 1084 | |
| 1085 | struct internalvar * |
| 1086 | lookup_internalvar (const char *name) |
| 1087 | { |
| 1088 | struct internalvar *var; |
| 1089 | |
| 1090 | var = lookup_only_internalvar (name); |
| 1091 | if (var) |
| 1092 | return var; |
| 1093 | |
| 1094 | return create_internalvar (name); |
| 1095 | } |
| 1096 | |
| 1097 | /* Return current value of internal variable VAR. For variables that |
| 1098 | are not inherently typed, use a value type appropriate for GDBARCH. */ |
| 1099 | |
| 1100 | struct value * |
| 1101 | value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var) |
| 1102 | { |
| 1103 | struct value *val; |
| 1104 | |
| 1105 | switch (var->kind) |
| 1106 | { |
| 1107 | case INTERNALVAR_VOID: |
| 1108 | val = allocate_value (builtin_type (gdbarch)->builtin_void); |
| 1109 | break; |
| 1110 | |
| 1111 | case INTERNALVAR_FUNCTION: |
| 1112 | val = allocate_value (builtin_type (gdbarch)->internal_fn); |
| 1113 | break; |
| 1114 | |
| 1115 | case INTERNALVAR_INTEGER: |
| 1116 | if (!var->u.integer.type) |
| 1117 | val = value_from_longest (builtin_type (gdbarch)->builtin_int, |
| 1118 | var->u.integer.val); |
| 1119 | else |
| 1120 | val = value_from_longest (var->u.integer.type, var->u.integer.val); |
| 1121 | break; |
| 1122 | |
| 1123 | case INTERNALVAR_POINTER: |
| 1124 | val = value_from_pointer (var->u.pointer.type, var->u.pointer.val); |
| 1125 | break; |
| 1126 | |
| 1127 | case INTERNALVAR_STRING: |
| 1128 | val = value_cstring (var->u.string, strlen (var->u.string), |
| 1129 | builtin_type (gdbarch)->builtin_char); |
| 1130 | break; |
| 1131 | |
| 1132 | case INTERNALVAR_VALUE: |
| 1133 | val = value_copy (var->u.value); |
| 1134 | if (value_lazy (val)) |
| 1135 | value_fetch_lazy (val); |
| 1136 | break; |
| 1137 | |
| 1138 | case INTERNALVAR_MAKE_VALUE: |
| 1139 | val = (*var->u.make_value) (gdbarch, var); |
| 1140 | break; |
| 1141 | |
| 1142 | default: |
| 1143 | internal_error (__FILE__, __LINE__, "bad kind"); |
| 1144 | } |
| 1145 | |
| 1146 | /* Change the VALUE_LVAL to lval_internalvar so that future operations |
| 1147 | on this value go back to affect the original internal variable. |
| 1148 | |
| 1149 | Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have |
| 1150 | no underlying modifyable state in the internal variable. |
| 1151 | |
| 1152 | Likewise, if the variable's value is a computed lvalue, we want |
| 1153 | references to it to produce another computed lvalue, where |
| 1154 | references and assignments actually operate through the |
| 1155 | computed value's functions. |
| 1156 | |
| 1157 | This means that internal variables with computed values |
| 1158 | behave a little differently from other internal variables: |
| 1159 | assignments to them don't just replace the previous value |
| 1160 | altogether. At the moment, this seems like the behavior we |
| 1161 | want. */ |
| 1162 | |
| 1163 | if (var->kind != INTERNALVAR_MAKE_VALUE |
| 1164 | && val->lval != lval_computed) |
| 1165 | { |
| 1166 | VALUE_LVAL (val) = lval_internalvar; |
| 1167 | VALUE_INTERNALVAR (val) = var; |
| 1168 | } |
| 1169 | |
| 1170 | return val; |
| 1171 | } |
| 1172 | |
| 1173 | int |
| 1174 | get_internalvar_integer (struct internalvar *var, LONGEST *result) |
| 1175 | { |
| 1176 | switch (var->kind) |
| 1177 | { |
| 1178 | case INTERNALVAR_INTEGER: |
| 1179 | *result = var->u.integer.val; |
| 1180 | return 1; |
| 1181 | |
| 1182 | default: |
| 1183 | return 0; |
| 1184 | } |
| 1185 | } |
| 1186 | |
| 1187 | static int |
| 1188 | get_internalvar_function (struct internalvar *var, |
| 1189 | struct internal_function **result) |
| 1190 | { |
| 1191 | switch (var->kind) |
| 1192 | { |
| 1193 | case INTERNALVAR_FUNCTION: |
| 1194 | *result = var->u.fn.function; |
| 1195 | return 1; |
| 1196 | |
| 1197 | default: |
| 1198 | return 0; |
| 1199 | } |
| 1200 | } |
| 1201 | |
| 1202 | void |
| 1203 | set_internalvar_component (struct internalvar *var, int offset, int bitpos, |
| 1204 | int bitsize, struct value *newval) |
| 1205 | { |
| 1206 | gdb_byte *addr; |
| 1207 | |
| 1208 | switch (var->kind) |
| 1209 | { |
| 1210 | case INTERNALVAR_VALUE: |
| 1211 | addr = value_contents_writeable (var->u.value); |
| 1212 | |
| 1213 | if (bitsize) |
| 1214 | modify_field (value_type (var->u.value), addr + offset, |
| 1215 | value_as_long (newval), bitpos, bitsize); |
| 1216 | else |
| 1217 | memcpy (addr + offset, value_contents (newval), |
| 1218 | TYPE_LENGTH (value_type (newval))); |
| 1219 | break; |
| 1220 | |
| 1221 | default: |
| 1222 | /* We can never get a component of any other kind. */ |
| 1223 | internal_error (__FILE__, __LINE__, "set_internalvar_component"); |
| 1224 | } |
| 1225 | } |
| 1226 | |
| 1227 | void |
| 1228 | set_internalvar (struct internalvar *var, struct value *val) |
| 1229 | { |
| 1230 | enum internalvar_kind new_kind; |
| 1231 | union internalvar_data new_data = { 0 }; |
| 1232 | |
| 1233 | if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical) |
| 1234 | error (_("Cannot overwrite convenience function %s"), var->name); |
| 1235 | |
| 1236 | /* Prepare new contents. */ |
| 1237 | switch (TYPE_CODE (check_typedef (value_type (val)))) |
| 1238 | { |
| 1239 | case TYPE_CODE_VOID: |
| 1240 | new_kind = INTERNALVAR_VOID; |
| 1241 | break; |
| 1242 | |
| 1243 | case TYPE_CODE_INTERNAL_FUNCTION: |
| 1244 | gdb_assert (VALUE_LVAL (val) == lval_internalvar); |
| 1245 | new_kind = INTERNALVAR_FUNCTION; |
| 1246 | get_internalvar_function (VALUE_INTERNALVAR (val), |
| 1247 | &new_data.fn.function); |
| 1248 | /* Copies created here are never canonical. */ |
| 1249 | break; |
| 1250 | |
| 1251 | case TYPE_CODE_INT: |
| 1252 | new_kind = INTERNALVAR_INTEGER; |
| 1253 | new_data.integer.type = value_type (val); |
| 1254 | new_data.integer.val = value_as_long (val); |
| 1255 | break; |
| 1256 | |
| 1257 | case TYPE_CODE_PTR: |
| 1258 | new_kind = INTERNALVAR_POINTER; |
| 1259 | new_data.pointer.type = value_type (val); |
| 1260 | new_data.pointer.val = value_as_address (val); |
| 1261 | break; |
| 1262 | |
| 1263 | default: |
| 1264 | new_kind = INTERNALVAR_VALUE; |
| 1265 | new_data.value = value_copy (val); |
| 1266 | new_data.value->modifiable = 1; |
| 1267 | |
| 1268 | /* Force the value to be fetched from the target now, to avoid problems |
| 1269 | later when this internalvar is referenced and the target is gone or |
| 1270 | has changed. */ |
| 1271 | if (value_lazy (new_data.value)) |
| 1272 | value_fetch_lazy (new_data.value); |
| 1273 | |
| 1274 | /* Release the value from the value chain to prevent it from being |
| 1275 | deleted by free_all_values. From here on this function should not |
| 1276 | call error () until new_data is installed into the var->u to avoid |
| 1277 | leaking memory. */ |
| 1278 | release_value (new_data.value); |
| 1279 | break; |
| 1280 | } |
| 1281 | |
| 1282 | /* Clean up old contents. */ |
| 1283 | clear_internalvar (var); |
| 1284 | |
| 1285 | /* Switch over. */ |
| 1286 | var->kind = new_kind; |
| 1287 | var->u = new_data; |
| 1288 | /* End code which must not call error(). */ |
| 1289 | } |
| 1290 | |
| 1291 | void |
| 1292 | set_internalvar_integer (struct internalvar *var, LONGEST l) |
| 1293 | { |
| 1294 | /* Clean up old contents. */ |
| 1295 | clear_internalvar (var); |
| 1296 | |
| 1297 | var->kind = INTERNALVAR_INTEGER; |
| 1298 | var->u.integer.type = NULL; |
| 1299 | var->u.integer.val = l; |
| 1300 | } |
| 1301 | |
| 1302 | void |
| 1303 | set_internalvar_string (struct internalvar *var, const char *string) |
| 1304 | { |
| 1305 | /* Clean up old contents. */ |
| 1306 | clear_internalvar (var); |
| 1307 | |
| 1308 | var->kind = INTERNALVAR_STRING; |
| 1309 | var->u.string = xstrdup (string); |
| 1310 | } |
| 1311 | |
| 1312 | static void |
| 1313 | set_internalvar_function (struct internalvar *var, struct internal_function *f) |
| 1314 | { |
| 1315 | /* Clean up old contents. */ |
| 1316 | clear_internalvar (var); |
| 1317 | |
| 1318 | var->kind = INTERNALVAR_FUNCTION; |
| 1319 | var->u.fn.function = f; |
| 1320 | var->u.fn.canonical = 1; |
| 1321 | /* Variables installed here are always the canonical version. */ |
| 1322 | } |
| 1323 | |
| 1324 | void |
| 1325 | clear_internalvar (struct internalvar *var) |
| 1326 | { |
| 1327 | /* Clean up old contents. */ |
| 1328 | switch (var->kind) |
| 1329 | { |
| 1330 | case INTERNALVAR_VALUE: |
| 1331 | value_free (var->u.value); |
| 1332 | break; |
| 1333 | |
| 1334 | case INTERNALVAR_STRING: |
| 1335 | xfree (var->u.string); |
| 1336 | break; |
| 1337 | |
| 1338 | default: |
| 1339 | break; |
| 1340 | } |
| 1341 | |
| 1342 | /* Reset to void kind. */ |
| 1343 | var->kind = INTERNALVAR_VOID; |
| 1344 | } |
| 1345 | |
| 1346 | char * |
| 1347 | internalvar_name (struct internalvar *var) |
| 1348 | { |
| 1349 | return var->name; |
| 1350 | } |
| 1351 | |
| 1352 | static struct internal_function * |
| 1353 | create_internal_function (const char *name, |
| 1354 | internal_function_fn handler, void *cookie) |
| 1355 | { |
| 1356 | struct internal_function *ifn = XNEW (struct internal_function); |
| 1357 | ifn->name = xstrdup (name); |
| 1358 | ifn->handler = handler; |
| 1359 | ifn->cookie = cookie; |
| 1360 | return ifn; |
| 1361 | } |
| 1362 | |
| 1363 | char * |
| 1364 | value_internal_function_name (struct value *val) |
| 1365 | { |
| 1366 | struct internal_function *ifn; |
| 1367 | int result; |
| 1368 | |
| 1369 | gdb_assert (VALUE_LVAL (val) == lval_internalvar); |
| 1370 | result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn); |
| 1371 | gdb_assert (result); |
| 1372 | |
| 1373 | return ifn->name; |
| 1374 | } |
| 1375 | |
| 1376 | struct value * |
| 1377 | call_internal_function (struct gdbarch *gdbarch, |
| 1378 | const struct language_defn *language, |
| 1379 | struct value *func, int argc, struct value **argv) |
| 1380 | { |
| 1381 | struct internal_function *ifn; |
| 1382 | int result; |
| 1383 | |
| 1384 | gdb_assert (VALUE_LVAL (func) == lval_internalvar); |
| 1385 | result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn); |
| 1386 | gdb_assert (result); |
| 1387 | |
| 1388 | return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv); |
| 1389 | } |
| 1390 | |
| 1391 | /* The 'function' command. This does nothing -- it is just a |
| 1392 | placeholder to let "help function NAME" work. This is also used as |
| 1393 | the implementation of the sub-command that is created when |
| 1394 | registering an internal function. */ |
| 1395 | static void |
| 1396 | function_command (char *command, int from_tty) |
| 1397 | { |
| 1398 | /* Do nothing. */ |
| 1399 | } |
| 1400 | |
| 1401 | /* Clean up if an internal function's command is destroyed. */ |
| 1402 | static void |
| 1403 | function_destroyer (struct cmd_list_element *self, void *ignore) |
| 1404 | { |
| 1405 | xfree (self->name); |
| 1406 | xfree (self->doc); |
| 1407 | } |
| 1408 | |
| 1409 | /* Add a new internal function. NAME is the name of the function; DOC |
| 1410 | is a documentation string describing the function. HANDLER is |
| 1411 | called when the function is invoked. COOKIE is an arbitrary |
| 1412 | pointer which is passed to HANDLER and is intended for "user |
| 1413 | data". */ |
| 1414 | void |
| 1415 | add_internal_function (const char *name, const char *doc, |
| 1416 | internal_function_fn handler, void *cookie) |
| 1417 | { |
| 1418 | struct cmd_list_element *cmd; |
| 1419 | struct internal_function *ifn; |
| 1420 | struct internalvar *var = lookup_internalvar (name); |
| 1421 | |
| 1422 | ifn = create_internal_function (name, handler, cookie); |
| 1423 | set_internalvar_function (var, ifn); |
| 1424 | |
| 1425 | cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc, |
| 1426 | &functionlist); |
| 1427 | cmd->destroyer = function_destroyer; |
| 1428 | } |
| 1429 | |
| 1430 | /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to |
| 1431 | prevent cycles / duplicates. */ |
| 1432 | |
| 1433 | void |
| 1434 | preserve_one_value (struct value *value, struct objfile *objfile, |
| 1435 | htab_t copied_types) |
| 1436 | { |
| 1437 | if (TYPE_OBJFILE (value->type) == objfile) |
| 1438 | value->type = copy_type_recursive (objfile, value->type, copied_types); |
| 1439 | |
| 1440 | if (TYPE_OBJFILE (value->enclosing_type) == objfile) |
| 1441 | value->enclosing_type = copy_type_recursive (objfile, |
| 1442 | value->enclosing_type, |
| 1443 | copied_types); |
| 1444 | } |
| 1445 | |
| 1446 | /* Likewise for internal variable VAR. */ |
| 1447 | |
| 1448 | static void |
| 1449 | preserve_one_internalvar (struct internalvar *var, struct objfile *objfile, |
| 1450 | htab_t copied_types) |
| 1451 | { |
| 1452 | switch (var->kind) |
| 1453 | { |
| 1454 | case INTERNALVAR_INTEGER: |
| 1455 | if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile) |
| 1456 | var->u.integer.type |
| 1457 | = copy_type_recursive (objfile, var->u.integer.type, copied_types); |
| 1458 | break; |
| 1459 | |
| 1460 | case INTERNALVAR_POINTER: |
| 1461 | if (TYPE_OBJFILE (var->u.pointer.type) == objfile) |
| 1462 | var->u.pointer.type |
| 1463 | = copy_type_recursive (objfile, var->u.pointer.type, copied_types); |
| 1464 | break; |
| 1465 | |
| 1466 | case INTERNALVAR_VALUE: |
| 1467 | preserve_one_value (var->u.value, objfile, copied_types); |
| 1468 | break; |
| 1469 | } |
| 1470 | } |
| 1471 | |
| 1472 | /* Update the internal variables and value history when OBJFILE is |
| 1473 | discarded; we must copy the types out of the objfile. New global types |
| 1474 | will be created for every convenience variable which currently points to |
| 1475 | this objfile's types, and the convenience variables will be adjusted to |
| 1476 | use the new global types. */ |
| 1477 | |
| 1478 | void |
| 1479 | preserve_values (struct objfile *objfile) |
| 1480 | { |
| 1481 | htab_t copied_types; |
| 1482 | struct value_history_chunk *cur; |
| 1483 | struct internalvar *var; |
| 1484 | struct value *val; |
| 1485 | int i; |
| 1486 | |
| 1487 | /* Create the hash table. We allocate on the objfile's obstack, since |
| 1488 | it is soon to be deleted. */ |
| 1489 | copied_types = create_copied_types_hash (objfile); |
| 1490 | |
| 1491 | for (cur = value_history_chain; cur; cur = cur->next) |
| 1492 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) |
| 1493 | if (cur->values[i]) |
| 1494 | preserve_one_value (cur->values[i], objfile, copied_types); |
| 1495 | |
| 1496 | for (var = internalvars; var; var = var->next) |
| 1497 | preserve_one_internalvar (var, objfile, copied_types); |
| 1498 | |
| 1499 | preserve_python_values (objfile, copied_types); |
| 1500 | |
| 1501 | htab_delete (copied_types); |
| 1502 | } |
| 1503 | |
| 1504 | static void |
| 1505 | show_convenience (char *ignore, int from_tty) |
| 1506 | { |
| 1507 | struct gdbarch *gdbarch = get_current_arch (); |
| 1508 | struct internalvar *var; |
| 1509 | int varseen = 0; |
| 1510 | struct value_print_options opts; |
| 1511 | |
| 1512 | get_user_print_options (&opts); |
| 1513 | for (var = internalvars; var; var = var->next) |
| 1514 | { |
| 1515 | if (!varseen) |
| 1516 | { |
| 1517 | varseen = 1; |
| 1518 | } |
| 1519 | printf_filtered (("$%s = "), var->name); |
| 1520 | value_print (value_of_internalvar (gdbarch, var), gdb_stdout, |
| 1521 | &opts); |
| 1522 | printf_filtered (("\n")); |
| 1523 | } |
| 1524 | if (!varseen) |
| 1525 | printf_unfiltered (_("\ |
| 1526 | No debugger convenience variables now defined.\n\ |
| 1527 | Convenience variables have names starting with \"$\";\n\ |
| 1528 | use \"set\" as in \"set $foo = 5\" to define them.\n")); |
| 1529 | } |
| 1530 | \f |
| 1531 | /* Extract a value as a C number (either long or double). |
| 1532 | Knows how to convert fixed values to double, or |
| 1533 | floating values to long. |
| 1534 | Does not deallocate the value. */ |
| 1535 | |
| 1536 | LONGEST |
| 1537 | value_as_long (struct value *val) |
| 1538 | { |
| 1539 | /* This coerces arrays and functions, which is necessary (e.g. |
| 1540 | in disassemble_command). It also dereferences references, which |
| 1541 | I suspect is the most logical thing to do. */ |
| 1542 | val = coerce_array (val); |
| 1543 | return unpack_long (value_type (val), value_contents (val)); |
| 1544 | } |
| 1545 | |
| 1546 | DOUBLEST |
| 1547 | value_as_double (struct value *val) |
| 1548 | { |
| 1549 | DOUBLEST foo; |
| 1550 | int inv; |
| 1551 | |
| 1552 | foo = unpack_double (value_type (val), value_contents (val), &inv); |
| 1553 | if (inv) |
| 1554 | error (_("Invalid floating value found in program.")); |
| 1555 | return foo; |
| 1556 | } |
| 1557 | |
| 1558 | /* Extract a value as a C pointer. Does not deallocate the value. |
| 1559 | Note that val's type may not actually be a pointer; value_as_long |
| 1560 | handles all the cases. */ |
| 1561 | CORE_ADDR |
| 1562 | value_as_address (struct value *val) |
| 1563 | { |
| 1564 | struct gdbarch *gdbarch = get_type_arch (value_type (val)); |
| 1565 | |
| 1566 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 1567 | whether we want this to be true eventually. */ |
| 1568 | #if 0 |
| 1569 | /* gdbarch_addr_bits_remove is wrong if we are being called for a |
| 1570 | non-address (e.g. argument to "signal", "info break", etc.), or |
| 1571 | for pointers to char, in which the low bits *are* significant. */ |
| 1572 | return gdbarch_addr_bits_remove (gdbarch, value_as_long (val)); |
| 1573 | #else |
| 1574 | |
| 1575 | /* There are several targets (IA-64, PowerPC, and others) which |
| 1576 | don't represent pointers to functions as simply the address of |
| 1577 | the function's entry point. For example, on the IA-64, a |
| 1578 | function pointer points to a two-word descriptor, generated by |
| 1579 | the linker, which contains the function's entry point, and the |
| 1580 | value the IA-64 "global pointer" register should have --- to |
| 1581 | support position-independent code. The linker generates |
| 1582 | descriptors only for those functions whose addresses are taken. |
| 1583 | |
| 1584 | On such targets, it's difficult for GDB to convert an arbitrary |
| 1585 | function address into a function pointer; it has to either find |
| 1586 | an existing descriptor for that function, or call malloc and |
| 1587 | build its own. On some targets, it is impossible for GDB to |
| 1588 | build a descriptor at all: the descriptor must contain a jump |
| 1589 | instruction; data memory cannot be executed; and code memory |
| 1590 | cannot be modified. |
| 1591 | |
| 1592 | Upon entry to this function, if VAL is a value of type `function' |
| 1593 | (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then |
| 1594 | value_address (val) is the address of the function. This is what |
| 1595 | you'll get if you evaluate an expression like `main'. The call |
| 1596 | to COERCE_ARRAY below actually does all the usual unary |
| 1597 | conversions, which includes converting values of type `function' |
| 1598 | to `pointer to function'. This is the challenging conversion |
| 1599 | discussed above. Then, `unpack_long' will convert that pointer |
| 1600 | back into an address. |
| 1601 | |
| 1602 | So, suppose the user types `disassemble foo' on an architecture |
| 1603 | with a strange function pointer representation, on which GDB |
| 1604 | cannot build its own descriptors, and suppose further that `foo' |
| 1605 | has no linker-built descriptor. The address->pointer conversion |
| 1606 | will signal an error and prevent the command from running, even |
| 1607 | though the next step would have been to convert the pointer |
| 1608 | directly back into the same address. |
| 1609 | |
| 1610 | The following shortcut avoids this whole mess. If VAL is a |
| 1611 | function, just return its address directly. */ |
| 1612 | if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC |
| 1613 | || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD) |
| 1614 | return value_address (val); |
| 1615 | |
| 1616 | val = coerce_array (val); |
| 1617 | |
| 1618 | /* Some architectures (e.g. Harvard), map instruction and data |
| 1619 | addresses onto a single large unified address space. For |
| 1620 | instance: An architecture may consider a large integer in the |
| 1621 | range 0x10000000 .. 0x1000ffff to already represent a data |
| 1622 | addresses (hence not need a pointer to address conversion) while |
| 1623 | a small integer would still need to be converted integer to |
| 1624 | pointer to address. Just assume such architectures handle all |
| 1625 | integer conversions in a single function. */ |
| 1626 | |
| 1627 | /* JimB writes: |
| 1628 | |
| 1629 | I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we |
| 1630 | must admonish GDB hackers to make sure its behavior matches the |
| 1631 | compiler's, whenever possible. |
| 1632 | |
| 1633 | In general, I think GDB should evaluate expressions the same way |
| 1634 | the compiler does. When the user copies an expression out of |
| 1635 | their source code and hands it to a `print' command, they should |
| 1636 | get the same value the compiler would have computed. Any |
| 1637 | deviation from this rule can cause major confusion and annoyance, |
| 1638 | and needs to be justified carefully. In other words, GDB doesn't |
| 1639 | really have the freedom to do these conversions in clever and |
| 1640 | useful ways. |
| 1641 | |
| 1642 | AndrewC pointed out that users aren't complaining about how GDB |
| 1643 | casts integers to pointers; they are complaining that they can't |
| 1644 | take an address from a disassembly listing and give it to `x/i'. |
| 1645 | This is certainly important. |
| 1646 | |
| 1647 | Adding an architecture method like integer_to_address() certainly |
| 1648 | makes it possible for GDB to "get it right" in all circumstances |
| 1649 | --- the target has complete control over how things get done, so |
| 1650 | people can Do The Right Thing for their target without breaking |
| 1651 | anyone else. The standard doesn't specify how integers get |
| 1652 | converted to pointers; usually, the ABI doesn't either, but |
| 1653 | ABI-specific code is a more reasonable place to handle it. */ |
| 1654 | |
| 1655 | if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR |
| 1656 | && TYPE_CODE (value_type (val)) != TYPE_CODE_REF |
| 1657 | && gdbarch_integer_to_address_p (gdbarch)) |
| 1658 | return gdbarch_integer_to_address (gdbarch, value_type (val), |
| 1659 | value_contents (val)); |
| 1660 | |
| 1661 | return unpack_long (value_type (val), value_contents (val)); |
| 1662 | #endif |
| 1663 | } |
| 1664 | \f |
| 1665 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 1666 | as a long, or as a double, assuming the raw data is described |
| 1667 | by type TYPE. Knows how to convert different sizes of values |
| 1668 | and can convert between fixed and floating point. We don't assume |
| 1669 | any alignment for the raw data. Return value is in host byte order. |
| 1670 | |
| 1671 | If you want functions and arrays to be coerced to pointers, and |
| 1672 | references to be dereferenced, call value_as_long() instead. |
| 1673 | |
| 1674 | C++: It is assumed that the front-end has taken care of |
| 1675 | all matters concerning pointers to members. A pointer |
| 1676 | to member which reaches here is considered to be equivalent |
| 1677 | to an INT (or some size). After all, it is only an offset. */ |
| 1678 | |
| 1679 | LONGEST |
| 1680 | unpack_long (struct type *type, const gdb_byte *valaddr) |
| 1681 | { |
| 1682 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 1683 | enum type_code code = TYPE_CODE (type); |
| 1684 | int len = TYPE_LENGTH (type); |
| 1685 | int nosign = TYPE_UNSIGNED (type); |
| 1686 | |
| 1687 | switch (code) |
| 1688 | { |
| 1689 | case TYPE_CODE_TYPEDEF: |
| 1690 | return unpack_long (check_typedef (type), valaddr); |
| 1691 | case TYPE_CODE_ENUM: |
| 1692 | case TYPE_CODE_FLAGS: |
| 1693 | case TYPE_CODE_BOOL: |
| 1694 | case TYPE_CODE_INT: |
| 1695 | case TYPE_CODE_CHAR: |
| 1696 | case TYPE_CODE_RANGE: |
| 1697 | case TYPE_CODE_MEMBERPTR: |
| 1698 | if (nosign) |
| 1699 | return extract_unsigned_integer (valaddr, len, byte_order); |
| 1700 | else |
| 1701 | return extract_signed_integer (valaddr, len, byte_order); |
| 1702 | |
| 1703 | case TYPE_CODE_FLT: |
| 1704 | return extract_typed_floating (valaddr, type); |
| 1705 | |
| 1706 | case TYPE_CODE_DECFLOAT: |
| 1707 | /* libdecnumber has a function to convert from decimal to integer, but |
| 1708 | it doesn't work when the decimal number has a fractional part. */ |
| 1709 | return decimal_to_doublest (valaddr, len, byte_order); |
| 1710 | |
| 1711 | case TYPE_CODE_PTR: |
| 1712 | case TYPE_CODE_REF: |
| 1713 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 1714 | whether we want this to be true eventually. */ |
| 1715 | return extract_typed_address (valaddr, type); |
| 1716 | |
| 1717 | default: |
| 1718 | error (_("Value can't be converted to integer.")); |
| 1719 | } |
| 1720 | return 0; /* Placate lint. */ |
| 1721 | } |
| 1722 | |
| 1723 | /* Return a double value from the specified type and address. |
| 1724 | INVP points to an int which is set to 0 for valid value, |
| 1725 | 1 for invalid value (bad float format). In either case, |
| 1726 | the returned double is OK to use. Argument is in target |
| 1727 | format, result is in host format. */ |
| 1728 | |
| 1729 | DOUBLEST |
| 1730 | unpack_double (struct type *type, const gdb_byte *valaddr, int *invp) |
| 1731 | { |
| 1732 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 1733 | enum type_code code; |
| 1734 | int len; |
| 1735 | int nosign; |
| 1736 | |
| 1737 | *invp = 0; /* Assume valid. */ |
| 1738 | CHECK_TYPEDEF (type); |
| 1739 | code = TYPE_CODE (type); |
| 1740 | len = TYPE_LENGTH (type); |
| 1741 | nosign = TYPE_UNSIGNED (type); |
| 1742 | if (code == TYPE_CODE_FLT) |
| 1743 | { |
| 1744 | /* NOTE: cagney/2002-02-19: There was a test here to see if the |
| 1745 | floating-point value was valid (using the macro |
| 1746 | INVALID_FLOAT). That test/macro have been removed. |
| 1747 | |
| 1748 | It turns out that only the VAX defined this macro and then |
| 1749 | only in a non-portable way. Fixing the portability problem |
| 1750 | wouldn't help since the VAX floating-point code is also badly |
| 1751 | bit-rotten. The target needs to add definitions for the |
| 1752 | methods gdbarch_float_format and gdbarch_double_format - these |
| 1753 | exactly describe the target floating-point format. The |
| 1754 | problem here is that the corresponding floatformat_vax_f and |
| 1755 | floatformat_vax_d values these methods should be set to are |
| 1756 | also not defined either. Oops! |
| 1757 | |
| 1758 | Hopefully someone will add both the missing floatformat |
| 1759 | definitions and the new cases for floatformat_is_valid (). */ |
| 1760 | |
| 1761 | if (!floatformat_is_valid (floatformat_from_type (type), valaddr)) |
| 1762 | { |
| 1763 | *invp = 1; |
| 1764 | return 0.0; |
| 1765 | } |
| 1766 | |
| 1767 | return extract_typed_floating (valaddr, type); |
| 1768 | } |
| 1769 | else if (code == TYPE_CODE_DECFLOAT) |
| 1770 | return decimal_to_doublest (valaddr, len, byte_order); |
| 1771 | else if (nosign) |
| 1772 | { |
| 1773 | /* Unsigned -- be sure we compensate for signed LONGEST. */ |
| 1774 | return (ULONGEST) unpack_long (type, valaddr); |
| 1775 | } |
| 1776 | else |
| 1777 | { |
| 1778 | /* Signed -- we are OK with unpack_long. */ |
| 1779 | return unpack_long (type, valaddr); |
| 1780 | } |
| 1781 | } |
| 1782 | |
| 1783 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 1784 | as a CORE_ADDR, assuming the raw data is described by type TYPE. |
| 1785 | We don't assume any alignment for the raw data. Return value is in |
| 1786 | host byte order. |
| 1787 | |
| 1788 | If you want functions and arrays to be coerced to pointers, and |
| 1789 | references to be dereferenced, call value_as_address() instead. |
| 1790 | |
| 1791 | C++: It is assumed that the front-end has taken care of |
| 1792 | all matters concerning pointers to members. A pointer |
| 1793 | to member which reaches here is considered to be equivalent |
| 1794 | to an INT (or some size). After all, it is only an offset. */ |
| 1795 | |
| 1796 | CORE_ADDR |
| 1797 | unpack_pointer (struct type *type, const gdb_byte *valaddr) |
| 1798 | { |
| 1799 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 1800 | whether we want this to be true eventually. */ |
| 1801 | return unpack_long (type, valaddr); |
| 1802 | } |
| 1803 | |
| 1804 | \f |
| 1805 | /* Get the value of the FIELDN'th field (which must be static) of |
| 1806 | TYPE. Return NULL if the field doesn't exist or has been |
| 1807 | optimized out. */ |
| 1808 | |
| 1809 | struct value * |
| 1810 | value_static_field (struct type *type, int fieldno) |
| 1811 | { |
| 1812 | struct value *retval; |
| 1813 | |
| 1814 | if (TYPE_FIELD_LOC_KIND (type, fieldno) == FIELD_LOC_KIND_PHYSADDR) |
| 1815 | { |
| 1816 | retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno), |
| 1817 | TYPE_FIELD_STATIC_PHYSADDR (type, fieldno)); |
| 1818 | } |
| 1819 | else |
| 1820 | { |
| 1821 | char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno); |
| 1822 | /*TYPE_FIELD_NAME (type, fieldno);*/ |
| 1823 | struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0); |
| 1824 | |
| 1825 | if (sym == NULL) |
| 1826 | { |
| 1827 | /* With some compilers, e.g. HP aCC, static data members are reported |
| 1828 | as non-debuggable symbols */ |
| 1829 | struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL); |
| 1830 | if (!msym) |
| 1831 | return NULL; |
| 1832 | else |
| 1833 | { |
| 1834 | retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno), |
| 1835 | SYMBOL_VALUE_ADDRESS (msym)); |
| 1836 | } |
| 1837 | } |
| 1838 | else |
| 1839 | { |
| 1840 | /* SYM should never have a SYMBOL_CLASS which will require |
| 1841 | read_var_value to use the FRAME parameter. */ |
| 1842 | if (symbol_read_needs_frame (sym)) |
| 1843 | warning (_("static field's value depends on the current " |
| 1844 | "frame - bad debug info?")); |
| 1845 | retval = read_var_value (sym, NULL); |
| 1846 | } |
| 1847 | if (retval && VALUE_LVAL (retval) == lval_memory) |
| 1848 | SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno), |
| 1849 | value_address (retval)); |
| 1850 | } |
| 1851 | return retval; |
| 1852 | } |
| 1853 | |
| 1854 | /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE. |
| 1855 | You have to be careful here, since the size of the data area for the value |
| 1856 | is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger |
| 1857 | than the old enclosing type, you have to allocate more space for the data. |
| 1858 | The return value is a pointer to the new version of this value structure. */ |
| 1859 | |
| 1860 | struct value * |
| 1861 | value_change_enclosing_type (struct value *val, struct type *new_encl_type) |
| 1862 | { |
| 1863 | if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val))) |
| 1864 | val->contents = |
| 1865 | (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type)); |
| 1866 | |
| 1867 | val->enclosing_type = new_encl_type; |
| 1868 | return val; |
| 1869 | } |
| 1870 | |
| 1871 | /* Given a value ARG1 (offset by OFFSET bytes) |
| 1872 | of a struct or union type ARG_TYPE, |
| 1873 | extract and return the value of one of its (non-static) fields. |
| 1874 | FIELDNO says which field. */ |
| 1875 | |
| 1876 | struct value * |
| 1877 | value_primitive_field (struct value *arg1, int offset, |
| 1878 | int fieldno, struct type *arg_type) |
| 1879 | { |
| 1880 | struct value *v; |
| 1881 | struct type *type; |
| 1882 | |
| 1883 | CHECK_TYPEDEF (arg_type); |
| 1884 | type = TYPE_FIELD_TYPE (arg_type, fieldno); |
| 1885 | |
| 1886 | /* Call check_typedef on our type to make sure that, if TYPE |
| 1887 | is a TYPE_CODE_TYPEDEF, its length is set to the length |
| 1888 | of the target type instead of zero. However, we do not |
| 1889 | replace the typedef type by the target type, because we want |
| 1890 | to keep the typedef in order to be able to print the type |
| 1891 | description correctly. */ |
| 1892 | check_typedef (type); |
| 1893 | |
| 1894 | /* Handle packed fields */ |
| 1895 | |
| 1896 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) |
| 1897 | { |
| 1898 | /* Create a new value for the bitfield, with bitpos and bitsize |
| 1899 | set. If possible, arrange offset and bitpos so that we can |
| 1900 | do a single aligned read of the size of the containing type. |
| 1901 | Otherwise, adjust offset to the byte containing the first |
| 1902 | bit. Assume that the address, offset, and embedded offset |
| 1903 | are sufficiently aligned. */ |
| 1904 | int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno); |
| 1905 | int container_bitsize = TYPE_LENGTH (type) * 8; |
| 1906 | |
| 1907 | v = allocate_value_lazy (type); |
| 1908 | v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno); |
| 1909 | if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize |
| 1910 | && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)) |
| 1911 | v->bitpos = bitpos % container_bitsize; |
| 1912 | else |
| 1913 | v->bitpos = bitpos % 8; |
| 1914 | v->offset = value_embedded_offset (arg1) |
| 1915 | + (bitpos - v->bitpos) / 8; |
| 1916 | v->parent = arg1; |
| 1917 | value_incref (v->parent); |
| 1918 | if (!value_lazy (arg1)) |
| 1919 | value_fetch_lazy (v); |
| 1920 | } |
| 1921 | else if (fieldno < TYPE_N_BASECLASSES (arg_type)) |
| 1922 | { |
| 1923 | /* This field is actually a base subobject, so preserve the |
| 1924 | entire object's contents for later references to virtual |
| 1925 | bases, etc. */ |
| 1926 | |
| 1927 | /* Lazy register values with offsets are not supported. */ |
| 1928 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) |
| 1929 | value_fetch_lazy (arg1); |
| 1930 | |
| 1931 | if (value_lazy (arg1)) |
| 1932 | v = allocate_value_lazy (value_enclosing_type (arg1)); |
| 1933 | else |
| 1934 | { |
| 1935 | v = allocate_value (value_enclosing_type (arg1)); |
| 1936 | memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1), |
| 1937 | TYPE_LENGTH (value_enclosing_type (arg1))); |
| 1938 | } |
| 1939 | v->type = type; |
| 1940 | v->offset = value_offset (arg1); |
| 1941 | v->embedded_offset = (offset + value_embedded_offset (arg1) |
| 1942 | + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8); |
| 1943 | } |
| 1944 | else |
| 1945 | { |
| 1946 | /* Plain old data member */ |
| 1947 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| 1948 | |
| 1949 | /* Lazy register values with offsets are not supported. */ |
| 1950 | if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1)) |
| 1951 | value_fetch_lazy (arg1); |
| 1952 | |
| 1953 | if (value_lazy (arg1)) |
| 1954 | v = allocate_value_lazy (type); |
| 1955 | else |
| 1956 | { |
| 1957 | v = allocate_value (type); |
| 1958 | memcpy (value_contents_raw (v), |
| 1959 | value_contents_raw (arg1) + offset, |
| 1960 | TYPE_LENGTH (type)); |
| 1961 | } |
| 1962 | v->offset = (value_offset (arg1) + offset |
| 1963 | + value_embedded_offset (arg1)); |
| 1964 | } |
| 1965 | set_value_component_location (v, arg1); |
| 1966 | VALUE_REGNUM (v) = VALUE_REGNUM (arg1); |
| 1967 | VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1); |
| 1968 | return v; |
| 1969 | } |
| 1970 | |
| 1971 | /* Given a value ARG1 of a struct or union type, |
| 1972 | extract and return the value of one of its (non-static) fields. |
| 1973 | FIELDNO says which field. */ |
| 1974 | |
| 1975 | struct value * |
| 1976 | value_field (struct value *arg1, int fieldno) |
| 1977 | { |
| 1978 | return value_primitive_field (arg1, 0, fieldno, value_type (arg1)); |
| 1979 | } |
| 1980 | |
| 1981 | /* Return a non-virtual function as a value. |
| 1982 | F is the list of member functions which contains the desired method. |
| 1983 | J is an index into F which provides the desired method. |
| 1984 | |
| 1985 | We only use the symbol for its address, so be happy with either a |
| 1986 | full symbol or a minimal symbol. |
| 1987 | */ |
| 1988 | |
| 1989 | struct value * |
| 1990 | value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type, |
| 1991 | int offset) |
| 1992 | { |
| 1993 | struct value *v; |
| 1994 | struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
| 1995 | char *physname = TYPE_FN_FIELD_PHYSNAME (f, j); |
| 1996 | struct symbol *sym; |
| 1997 | struct minimal_symbol *msym; |
| 1998 | |
| 1999 | sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0); |
| 2000 | if (sym != NULL) |
| 2001 | { |
| 2002 | msym = NULL; |
| 2003 | } |
| 2004 | else |
| 2005 | { |
| 2006 | gdb_assert (sym == NULL); |
| 2007 | msym = lookup_minimal_symbol (physname, NULL, NULL); |
| 2008 | if (msym == NULL) |
| 2009 | return NULL; |
| 2010 | } |
| 2011 | |
| 2012 | v = allocate_value (ftype); |
| 2013 | if (sym) |
| 2014 | { |
| 2015 | set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym))); |
| 2016 | } |
| 2017 | else |
| 2018 | { |
| 2019 | /* The minimal symbol might point to a function descriptor; |
| 2020 | resolve it to the actual code address instead. */ |
| 2021 | struct objfile *objfile = msymbol_objfile (msym); |
| 2022 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 2023 | |
| 2024 | set_value_address (v, |
| 2025 | gdbarch_convert_from_func_ptr_addr |
| 2026 | (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target)); |
| 2027 | } |
| 2028 | |
| 2029 | if (arg1p) |
| 2030 | { |
| 2031 | if (type != value_type (*arg1p)) |
| 2032 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
| 2033 | value_addr (*arg1p))); |
| 2034 | |
| 2035 | /* Move the `this' pointer according to the offset. |
| 2036 | VALUE_OFFSET (*arg1p) += offset; |
| 2037 | */ |
| 2038 | } |
| 2039 | |
| 2040 | return v; |
| 2041 | } |
| 2042 | |
| 2043 | \f |
| 2044 | /* Unpack a bitfield of the specified FIELD_TYPE, from the anonymous |
| 2045 | object at VALADDR. The bitfield starts at BITPOS bits and contains |
| 2046 | BITSIZE bits. |
| 2047 | |
| 2048 | Extracting bits depends on endianness of the machine. Compute the |
| 2049 | number of least significant bits to discard. For big endian machines, |
| 2050 | we compute the total number of bits in the anonymous object, subtract |
| 2051 | off the bit count from the MSB of the object to the MSB of the |
| 2052 | bitfield, then the size of the bitfield, which leaves the LSB discard |
| 2053 | count. For little endian machines, the discard count is simply the |
| 2054 | number of bits from the LSB of the anonymous object to the LSB of the |
| 2055 | bitfield. |
| 2056 | |
| 2057 | If the field is signed, we also do sign extension. */ |
| 2058 | |
| 2059 | LONGEST |
| 2060 | unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr, |
| 2061 | int bitpos, int bitsize) |
| 2062 | { |
| 2063 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type)); |
| 2064 | ULONGEST val; |
| 2065 | ULONGEST valmask; |
| 2066 | int lsbcount; |
| 2067 | int bytes_read; |
| 2068 | |
| 2069 | /* Read the minimum number of bytes required; there may not be |
| 2070 | enough bytes to read an entire ULONGEST. */ |
| 2071 | CHECK_TYPEDEF (field_type); |
| 2072 | if (bitsize) |
| 2073 | bytes_read = ((bitpos % 8) + bitsize + 7) / 8; |
| 2074 | else |
| 2075 | bytes_read = TYPE_LENGTH (field_type); |
| 2076 | |
| 2077 | val = extract_unsigned_integer (valaddr + bitpos / 8, |
| 2078 | bytes_read, byte_order); |
| 2079 | |
| 2080 | /* Extract bits. See comment above. */ |
| 2081 | |
| 2082 | if (gdbarch_bits_big_endian (get_type_arch (field_type))) |
| 2083 | lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize); |
| 2084 | else |
| 2085 | lsbcount = (bitpos % 8); |
| 2086 | val >>= lsbcount; |
| 2087 | |
| 2088 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. |
| 2089 | If the field is signed, and is negative, then sign extend. */ |
| 2090 | |
| 2091 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) |
| 2092 | { |
| 2093 | valmask = (((ULONGEST) 1) << bitsize) - 1; |
| 2094 | val &= valmask; |
| 2095 | if (!TYPE_UNSIGNED (field_type)) |
| 2096 | { |
| 2097 | if (val & (valmask ^ (valmask >> 1))) |
| 2098 | { |
| 2099 | val |= ~valmask; |
| 2100 | } |
| 2101 | } |
| 2102 | } |
| 2103 | return (val); |
| 2104 | } |
| 2105 | |
| 2106 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at |
| 2107 | VALADDR. See unpack_bits_as_long for more details. */ |
| 2108 | |
| 2109 | LONGEST |
| 2110 | unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno) |
| 2111 | { |
| 2112 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); |
| 2113 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); |
| 2114 | struct type *field_type = TYPE_FIELD_TYPE (type, fieldno); |
| 2115 | |
| 2116 | return unpack_bits_as_long (field_type, valaddr, bitpos, bitsize); |
| 2117 | } |
| 2118 | |
| 2119 | /* Modify the value of a bitfield. ADDR points to a block of memory in |
| 2120 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL |
| 2121 | is the desired value of the field, in host byte order. BITPOS and BITSIZE |
| 2122 | indicate which bits (in target bit order) comprise the bitfield. |
| 2123 | Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and |
| 2124 | 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ |
| 2125 | |
| 2126 | void |
| 2127 | modify_field (struct type *type, gdb_byte *addr, |
| 2128 | LONGEST fieldval, int bitpos, int bitsize) |
| 2129 | { |
| 2130 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 2131 | ULONGEST oword; |
| 2132 | ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); |
| 2133 | |
| 2134 | /* If a negative fieldval fits in the field in question, chop |
| 2135 | off the sign extension bits. */ |
| 2136 | if ((~fieldval & ~(mask >> 1)) == 0) |
| 2137 | fieldval &= mask; |
| 2138 | |
| 2139 | /* Warn if value is too big to fit in the field in question. */ |
| 2140 | if (0 != (fieldval & ~mask)) |
| 2141 | { |
| 2142 | /* FIXME: would like to include fieldval in the message, but |
| 2143 | we don't have a sprintf_longest. */ |
| 2144 | warning (_("Value does not fit in %d bits."), bitsize); |
| 2145 | |
| 2146 | /* Truncate it, otherwise adjoining fields may be corrupted. */ |
| 2147 | fieldval &= mask; |
| 2148 | } |
| 2149 | |
| 2150 | oword = extract_unsigned_integer (addr, sizeof oword, byte_order); |
| 2151 | |
| 2152 | /* Shifting for bit field depends on endianness of the target machine. */ |
| 2153 | if (gdbarch_bits_big_endian (get_type_arch (type))) |
| 2154 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; |
| 2155 | |
| 2156 | oword &= ~(mask << bitpos); |
| 2157 | oword |= fieldval << bitpos; |
| 2158 | |
| 2159 | store_unsigned_integer (addr, sizeof oword, byte_order, oword); |
| 2160 | } |
| 2161 | \f |
| 2162 | /* Pack NUM into BUF using a target format of TYPE. */ |
| 2163 | |
| 2164 | void |
| 2165 | pack_long (gdb_byte *buf, struct type *type, LONGEST num) |
| 2166 | { |
| 2167 | enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); |
| 2168 | int len; |
| 2169 | |
| 2170 | type = check_typedef (type); |
| 2171 | len = TYPE_LENGTH (type); |
| 2172 | |
| 2173 | switch (TYPE_CODE (type)) |
| 2174 | { |
| 2175 | case TYPE_CODE_INT: |
| 2176 | case TYPE_CODE_CHAR: |
| 2177 | case TYPE_CODE_ENUM: |
| 2178 | case TYPE_CODE_FLAGS: |
| 2179 | case TYPE_CODE_BOOL: |
| 2180 | case TYPE_CODE_RANGE: |
| 2181 | case TYPE_CODE_MEMBERPTR: |
| 2182 | store_signed_integer (buf, len, byte_order, num); |
| 2183 | break; |
| 2184 | |
| 2185 | case TYPE_CODE_REF: |
| 2186 | case TYPE_CODE_PTR: |
| 2187 | store_typed_address (buf, type, (CORE_ADDR) num); |
| 2188 | break; |
| 2189 | |
| 2190 | default: |
| 2191 | error (_("Unexpected type (%d) encountered for integer constant."), |
| 2192 | TYPE_CODE (type)); |
| 2193 | } |
| 2194 | } |
| 2195 | |
| 2196 | |
| 2197 | /* Convert C numbers into newly allocated values. */ |
| 2198 | |
| 2199 | struct value * |
| 2200 | value_from_longest (struct type *type, LONGEST num) |
| 2201 | { |
| 2202 | struct value *val = allocate_value (type); |
| 2203 | |
| 2204 | pack_long (value_contents_raw (val), type, num); |
| 2205 | |
| 2206 | return val; |
| 2207 | } |
| 2208 | |
| 2209 | |
| 2210 | /* Create a value representing a pointer of type TYPE to the address |
| 2211 | ADDR. */ |
| 2212 | struct value * |
| 2213 | value_from_pointer (struct type *type, CORE_ADDR addr) |
| 2214 | { |
| 2215 | struct value *val = allocate_value (type); |
| 2216 | store_typed_address (value_contents_raw (val), check_typedef (type), addr); |
| 2217 | return val; |
| 2218 | } |
| 2219 | |
| 2220 | |
| 2221 | /* Create a value of type TYPE whose contents come from VALADDR, if it |
| 2222 | is non-null, and whose memory address (in the inferior) is |
| 2223 | ADDRESS. */ |
| 2224 | |
| 2225 | struct value * |
| 2226 | value_from_contents_and_address (struct type *type, |
| 2227 | const gdb_byte *valaddr, |
| 2228 | CORE_ADDR address) |
| 2229 | { |
| 2230 | struct value *v = allocate_value (type); |
| 2231 | if (valaddr == NULL) |
| 2232 | set_value_lazy (v, 1); |
| 2233 | else |
| 2234 | memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type)); |
| 2235 | set_value_address (v, address); |
| 2236 | VALUE_LVAL (v) = lval_memory; |
| 2237 | return v; |
| 2238 | } |
| 2239 | |
| 2240 | struct value * |
| 2241 | value_from_double (struct type *type, DOUBLEST num) |
| 2242 | { |
| 2243 | struct value *val = allocate_value (type); |
| 2244 | struct type *base_type = check_typedef (type); |
| 2245 | enum type_code code = TYPE_CODE (base_type); |
| 2246 | int len = TYPE_LENGTH (base_type); |
| 2247 | |
| 2248 | if (code == TYPE_CODE_FLT) |
| 2249 | { |
| 2250 | store_typed_floating (value_contents_raw (val), base_type, num); |
| 2251 | } |
| 2252 | else |
| 2253 | error (_("Unexpected type encountered for floating constant.")); |
| 2254 | |
| 2255 | return val; |
| 2256 | } |
| 2257 | |
| 2258 | struct value * |
| 2259 | value_from_decfloat (struct type *type, const gdb_byte *dec) |
| 2260 | { |
| 2261 | struct value *val = allocate_value (type); |
| 2262 | |
| 2263 | memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type)); |
| 2264 | |
| 2265 | return val; |
| 2266 | } |
| 2267 | |
| 2268 | struct value * |
| 2269 | coerce_ref (struct value *arg) |
| 2270 | { |
| 2271 | struct type *value_type_arg_tmp = check_typedef (value_type (arg)); |
| 2272 | if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) |
| 2273 | arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), |
| 2274 | unpack_pointer (value_type (arg), |
| 2275 | value_contents (arg))); |
| 2276 | return arg; |
| 2277 | } |
| 2278 | |
| 2279 | struct value * |
| 2280 | coerce_array (struct value *arg) |
| 2281 | { |
| 2282 | struct type *type; |
| 2283 | |
| 2284 | arg = coerce_ref (arg); |
| 2285 | type = check_typedef (value_type (arg)); |
| 2286 | |
| 2287 | switch (TYPE_CODE (type)) |
| 2288 | { |
| 2289 | case TYPE_CODE_ARRAY: |
| 2290 | if (current_language->c_style_arrays) |
| 2291 | arg = value_coerce_array (arg); |
| 2292 | break; |
| 2293 | case TYPE_CODE_FUNC: |
| 2294 | arg = value_coerce_function (arg); |
| 2295 | break; |
| 2296 | } |
| 2297 | return arg; |
| 2298 | } |
| 2299 | \f |
| 2300 | |
| 2301 | /* Return true if the function returning the specified type is using |
| 2302 | the convention of returning structures in memory (passing in the |
| 2303 | address as a hidden first parameter). */ |
| 2304 | |
| 2305 | int |
| 2306 | using_struct_return (struct gdbarch *gdbarch, |
| 2307 | struct type *func_type, struct type *value_type) |
| 2308 | { |
| 2309 | enum type_code code = TYPE_CODE (value_type); |
| 2310 | |
| 2311 | if (code == TYPE_CODE_ERROR) |
| 2312 | error (_("Function return type unknown.")); |
| 2313 | |
| 2314 | if (code == TYPE_CODE_VOID) |
| 2315 | /* A void return value is never in memory. See also corresponding |
| 2316 | code in "print_return_value". */ |
| 2317 | return 0; |
| 2318 | |
| 2319 | /* Probe the architecture for the return-value convention. */ |
| 2320 | return (gdbarch_return_value (gdbarch, func_type, value_type, |
| 2321 | NULL, NULL, NULL) |
| 2322 | != RETURN_VALUE_REGISTER_CONVENTION); |
| 2323 | } |
| 2324 | |
| 2325 | /* Set the initialized field in a value struct. */ |
| 2326 | |
| 2327 | void |
| 2328 | set_value_initialized (struct value *val, int status) |
| 2329 | { |
| 2330 | val->initialized = status; |
| 2331 | } |
| 2332 | |
| 2333 | /* Return the initialized field in a value struct. */ |
| 2334 | |
| 2335 | int |
| 2336 | value_initialized (struct value *val) |
| 2337 | { |
| 2338 | return val->initialized; |
| 2339 | } |
| 2340 | |
| 2341 | void |
| 2342 | _initialize_values (void) |
| 2343 | { |
| 2344 | add_cmd ("convenience", no_class, show_convenience, _("\ |
| 2345 | Debugger convenience (\"$foo\") variables.\n\ |
| 2346 | These variables are created when you assign them values;\n\ |
| 2347 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\ |
| 2348 | \n\ |
| 2349 | A few convenience variables are given values automatically:\n\ |
| 2350 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ |
| 2351 | \"$__\" holds the contents of the last address examined with \"x\"."), |
| 2352 | &showlist); |
| 2353 | |
| 2354 | add_cmd ("values", no_class, show_values, |
| 2355 | _("Elements of value history around item number IDX (or last ten)."), |
| 2356 | &showlist); |
| 2357 | |
| 2358 | add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\ |
| 2359 | Initialize a convenience variable if necessary.\n\ |
| 2360 | init-if-undefined VARIABLE = EXPRESSION\n\ |
| 2361 | Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\ |
| 2362 | exist or does not contain a value. The EXPRESSION is not evaluated if the\n\ |
| 2363 | VARIABLE is already initialized.")); |
| 2364 | |
| 2365 | add_prefix_cmd ("function", no_class, function_command, _("\ |
| 2366 | Placeholder command for showing help on convenience functions."), |
| 2367 | &functionlist, "function ", 0, &cmdlist); |
| 2368 | } |