| 1 | /* Low level packing and unpacking of values for GDB, the GNU Debugger. |
| 2 | Copyright 1986, 1987, 1989, 1991, 1993, 1994, 1995, 1996 |
| 3 | 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 2 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, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdb_string.h" |
| 23 | #include "symtab.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "value.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "frame.h" |
| 28 | #include "command.h" |
| 29 | #include "gdbcmd.h" |
| 30 | #include "target.h" |
| 31 | #include "language.h" |
| 32 | #include "scm-lang.h" |
| 33 | #include "demangle.h" |
| 34 | |
| 35 | /* Local function prototypes. */ |
| 36 | |
| 37 | static value_ptr value_headof PARAMS ((value_ptr, struct type *, |
| 38 | struct type *)); |
| 39 | |
| 40 | static void show_values PARAMS ((char *, int)); |
| 41 | |
| 42 | static void show_convenience PARAMS ((char *, int)); |
| 43 | |
| 44 | static int vb_match PARAMS ((struct type *, int, struct type *)); |
| 45 | |
| 46 | /* The value-history records all the values printed |
| 47 | by print commands during this session. Each chunk |
| 48 | records 60 consecutive values. The first chunk on |
| 49 | the chain records the most recent values. |
| 50 | The total number of values is in value_history_count. */ |
| 51 | |
| 52 | #define VALUE_HISTORY_CHUNK 60 |
| 53 | |
| 54 | struct value_history_chunk |
| 55 | { |
| 56 | struct value_history_chunk *next; |
| 57 | value_ptr values[VALUE_HISTORY_CHUNK]; |
| 58 | }; |
| 59 | |
| 60 | /* Chain of chunks now in use. */ |
| 61 | |
| 62 | static struct value_history_chunk *value_history_chain; |
| 63 | |
| 64 | static int value_history_count; /* Abs number of last entry stored */ |
| 65 | \f |
| 66 | /* List of all value objects currently allocated |
| 67 | (except for those released by calls to release_value) |
| 68 | This is so they can be freed after each command. */ |
| 69 | |
| 70 | static value_ptr all_values; |
| 71 | |
| 72 | /* Allocate a value that has the correct length for type TYPE. */ |
| 73 | |
| 74 | value_ptr |
| 75 | allocate_value (type) |
| 76 | struct type *type; |
| 77 | { |
| 78 | register value_ptr val; |
| 79 | struct type *atype = check_typedef (type); |
| 80 | |
| 81 | val = (struct value *) xmalloc (sizeof (struct value) + TYPE_LENGTH (atype)); |
| 82 | VALUE_NEXT (val) = all_values; |
| 83 | all_values = val; |
| 84 | VALUE_TYPE (val) = type; |
| 85 | VALUE_LVAL (val) = not_lval; |
| 86 | VALUE_ADDRESS (val) = 0; |
| 87 | VALUE_FRAME (val) = 0; |
| 88 | VALUE_OFFSET (val) = 0; |
| 89 | VALUE_BITPOS (val) = 0; |
| 90 | VALUE_BITSIZE (val) = 0; |
| 91 | VALUE_REGNO (val) = -1; |
| 92 | VALUE_LAZY (val) = 0; |
| 93 | VALUE_OPTIMIZED_OUT (val) = 0; |
| 94 | val->modifiable = 1; |
| 95 | return val; |
| 96 | } |
| 97 | |
| 98 | /* Allocate a value that has the correct length |
| 99 | for COUNT repetitions type TYPE. */ |
| 100 | |
| 101 | value_ptr |
| 102 | allocate_repeat_value (type, count) |
| 103 | struct type *type; |
| 104 | int count; |
| 105 | { |
| 106 | int low_bound = current_language->string_lower_bound; /* ??? */ |
| 107 | /* FIXME-type-allocation: need a way to free this type when we are |
| 108 | done with it. */ |
| 109 | struct type *range_type |
| 110 | = create_range_type ((struct type *) NULL, builtin_type_int, |
| 111 | low_bound, count + low_bound - 1); |
| 112 | /* FIXME-type-allocation: need a way to free this type when we are |
| 113 | done with it. */ |
| 114 | return allocate_value (create_array_type ((struct type *) NULL, |
| 115 | type, range_type)); |
| 116 | } |
| 117 | |
| 118 | /* Return a mark in the value chain. All values allocated after the |
| 119 | mark is obtained (except for those released) are subject to being freed |
| 120 | if a subsequent value_free_to_mark is passed the mark. */ |
| 121 | value_ptr |
| 122 | value_mark () |
| 123 | { |
| 124 | return all_values; |
| 125 | } |
| 126 | |
| 127 | /* Free all values allocated since MARK was obtained by value_mark |
| 128 | (except for those released). */ |
| 129 | void |
| 130 | value_free_to_mark (mark) |
| 131 | value_ptr mark; |
| 132 | { |
| 133 | value_ptr val, next; |
| 134 | |
| 135 | for (val = all_values; val && val != mark; val = next) |
| 136 | { |
| 137 | next = VALUE_NEXT (val); |
| 138 | value_free (val); |
| 139 | } |
| 140 | all_values = val; |
| 141 | } |
| 142 | |
| 143 | /* Free all the values that have been allocated (except for those released). |
| 144 | Called after each command, successful or not. */ |
| 145 | |
| 146 | void |
| 147 | free_all_values () |
| 148 | { |
| 149 | register value_ptr val, next; |
| 150 | |
| 151 | for (val = all_values; val; val = next) |
| 152 | { |
| 153 | next = VALUE_NEXT (val); |
| 154 | value_free (val); |
| 155 | } |
| 156 | |
| 157 | all_values = 0; |
| 158 | } |
| 159 | |
| 160 | /* Remove VAL from the chain all_values |
| 161 | so it will not be freed automatically. */ |
| 162 | |
| 163 | void |
| 164 | release_value (val) |
| 165 | register value_ptr val; |
| 166 | { |
| 167 | register value_ptr v; |
| 168 | |
| 169 | if (all_values == val) |
| 170 | { |
| 171 | all_values = val->next; |
| 172 | return; |
| 173 | } |
| 174 | |
| 175 | for (v = all_values; v; v = v->next) |
| 176 | { |
| 177 | if (v->next == val) |
| 178 | { |
| 179 | v->next = val->next; |
| 180 | break; |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* Release all values up to mark */ |
| 186 | value_ptr |
| 187 | value_release_to_mark (mark) |
| 188 | value_ptr mark; |
| 189 | { |
| 190 | value_ptr val, next; |
| 191 | |
| 192 | for (val = next = all_values; next; next = VALUE_NEXT (next)) |
| 193 | if (VALUE_NEXT (next) == mark) |
| 194 | { |
| 195 | all_values = VALUE_NEXT (next); |
| 196 | VALUE_NEXT (next) = 0; |
| 197 | return val; |
| 198 | } |
| 199 | all_values = 0; |
| 200 | return val; |
| 201 | } |
| 202 | |
| 203 | /* Return a copy of the value ARG. |
| 204 | It contains the same contents, for same memory address, |
| 205 | but it's a different block of storage. */ |
| 206 | |
| 207 | value_ptr |
| 208 | value_copy (arg) |
| 209 | value_ptr arg; |
| 210 | { |
| 211 | register struct type *type = VALUE_TYPE (arg); |
| 212 | register value_ptr val = allocate_value (type); |
| 213 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
| 214 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); |
| 215 | VALUE_OFFSET (val) = VALUE_OFFSET (arg); |
| 216 | VALUE_BITPOS (val) = VALUE_BITPOS (arg); |
| 217 | VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); |
| 218 | VALUE_FRAME (val) = VALUE_FRAME (arg); |
| 219 | VALUE_REGNO (val) = VALUE_REGNO (arg); |
| 220 | VALUE_LAZY (val) = VALUE_LAZY (arg); |
| 221 | VALUE_OPTIMIZED_OUT (val) = VALUE_OPTIMIZED_OUT (arg); |
| 222 | val->modifiable = arg->modifiable; |
| 223 | if (!VALUE_LAZY (val)) |
| 224 | { |
| 225 | memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS_RAW (arg), |
| 226 | TYPE_LENGTH (VALUE_TYPE (arg))); |
| 227 | } |
| 228 | return val; |
| 229 | } |
| 230 | \f |
| 231 | /* Access to the value history. */ |
| 232 | |
| 233 | /* Record a new value in the value history. |
| 234 | Returns the absolute history index of the entry. |
| 235 | Result of -1 indicates the value was not saved; otherwise it is the |
| 236 | value history index of this new item. */ |
| 237 | |
| 238 | int |
| 239 | record_latest_value (val) |
| 240 | value_ptr val; |
| 241 | { |
| 242 | int i; |
| 243 | |
| 244 | /* We don't want this value to have anything to do with the inferior anymore. |
| 245 | In particular, "set $1 = 50" should not affect the variable from which |
| 246 | the value was taken, and fast watchpoints should be able to assume that |
| 247 | a value on the value history never changes. */ |
| 248 | if (VALUE_LAZY (val)) |
| 249 | value_fetch_lazy (val); |
| 250 | /* We preserve VALUE_LVAL so that the user can find out where it was fetched |
| 251 | from. This is a bit dubious, because then *&$1 does not just return $1 |
| 252 | but the current contents of that location. c'est la vie... */ |
| 253 | val->modifiable = 0; |
| 254 | release_value (val); |
| 255 | |
| 256 | /* Here we treat value_history_count as origin-zero |
| 257 | and applying to the value being stored now. */ |
| 258 | |
| 259 | i = value_history_count % VALUE_HISTORY_CHUNK; |
| 260 | if (i == 0) |
| 261 | { |
| 262 | register struct value_history_chunk *new |
| 263 | = (struct value_history_chunk *) |
| 264 | xmalloc (sizeof (struct value_history_chunk)); |
| 265 | memset (new->values, 0, sizeof new->values); |
| 266 | new->next = value_history_chain; |
| 267 | value_history_chain = new; |
| 268 | } |
| 269 | |
| 270 | value_history_chain->values[i] = val; |
| 271 | |
| 272 | /* Now we regard value_history_count as origin-one |
| 273 | and applying to the value just stored. */ |
| 274 | |
| 275 | return ++value_history_count; |
| 276 | } |
| 277 | |
| 278 | /* Return a copy of the value in the history with sequence number NUM. */ |
| 279 | |
| 280 | value_ptr |
| 281 | access_value_history (num) |
| 282 | int num; |
| 283 | { |
| 284 | register struct value_history_chunk *chunk; |
| 285 | register int i; |
| 286 | register int absnum = num; |
| 287 | |
| 288 | if (absnum <= 0) |
| 289 | absnum += value_history_count; |
| 290 | |
| 291 | if (absnum <= 0) |
| 292 | { |
| 293 | if (num == 0) |
| 294 | error ("The history is empty."); |
| 295 | else if (num == 1) |
| 296 | error ("There is only one value in the history."); |
| 297 | else |
| 298 | error ("History does not go back to $$%d.", -num); |
| 299 | } |
| 300 | if (absnum > value_history_count) |
| 301 | error ("History has not yet reached $%d.", absnum); |
| 302 | |
| 303 | absnum--; |
| 304 | |
| 305 | /* Now absnum is always absolute and origin zero. */ |
| 306 | |
| 307 | chunk = value_history_chain; |
| 308 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; |
| 309 | i > 0; i--) |
| 310 | chunk = chunk->next; |
| 311 | |
| 312 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); |
| 313 | } |
| 314 | |
| 315 | /* Clear the value history entirely. |
| 316 | Must be done when new symbol tables are loaded, |
| 317 | because the type pointers become invalid. */ |
| 318 | |
| 319 | void |
| 320 | clear_value_history () |
| 321 | { |
| 322 | register struct value_history_chunk *next; |
| 323 | register int i; |
| 324 | register value_ptr val; |
| 325 | |
| 326 | while (value_history_chain) |
| 327 | { |
| 328 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) |
| 329 | if ((val = value_history_chain->values[i]) != NULL) |
| 330 | free ((PTR)val); |
| 331 | next = value_history_chain->next; |
| 332 | free ((PTR)value_history_chain); |
| 333 | value_history_chain = next; |
| 334 | } |
| 335 | value_history_count = 0; |
| 336 | } |
| 337 | |
| 338 | static void |
| 339 | show_values (num_exp, from_tty) |
| 340 | char *num_exp; |
| 341 | int from_tty; |
| 342 | { |
| 343 | register int i; |
| 344 | register value_ptr val; |
| 345 | static int num = 1; |
| 346 | |
| 347 | if (num_exp) |
| 348 | { |
| 349 | /* "info history +" should print from the stored position. |
| 350 | "info history <exp>" should print around value number <exp>. */ |
| 351 | if (num_exp[0] != '+' || num_exp[1] != '\0') |
| 352 | num = parse_and_eval_address (num_exp) - 5; |
| 353 | } |
| 354 | else |
| 355 | { |
| 356 | /* "info history" means print the last 10 values. */ |
| 357 | num = value_history_count - 9; |
| 358 | } |
| 359 | |
| 360 | if (num <= 0) |
| 361 | num = 1; |
| 362 | |
| 363 | for (i = num; i < num + 10 && i <= value_history_count; i++) |
| 364 | { |
| 365 | val = access_value_history (i); |
| 366 | printf_filtered ("$%d = ", i); |
| 367 | value_print (val, gdb_stdout, 0, Val_pretty_default); |
| 368 | printf_filtered ("\n"); |
| 369 | } |
| 370 | |
| 371 | /* The next "info history +" should start after what we just printed. */ |
| 372 | num += 10; |
| 373 | |
| 374 | /* Hitting just return after this command should do the same thing as |
| 375 | "info history +". If num_exp is null, this is unnecessary, since |
| 376 | "info history +" is not useful after "info history". */ |
| 377 | if (from_tty && num_exp) |
| 378 | { |
| 379 | num_exp[0] = '+'; |
| 380 | num_exp[1] = '\0'; |
| 381 | } |
| 382 | } |
| 383 | \f |
| 384 | /* Internal variables. These are variables within the debugger |
| 385 | that hold values assigned by debugger commands. |
| 386 | The user refers to them with a '$' prefix |
| 387 | that does not appear in the variable names stored internally. */ |
| 388 | |
| 389 | static struct internalvar *internalvars; |
| 390 | |
| 391 | /* Look up an internal variable with name NAME. NAME should not |
| 392 | normally include a dollar sign. |
| 393 | |
| 394 | If the specified internal variable does not exist, |
| 395 | one is created, with a void value. */ |
| 396 | |
| 397 | struct internalvar * |
| 398 | lookup_internalvar (name) |
| 399 | char *name; |
| 400 | { |
| 401 | register struct internalvar *var; |
| 402 | |
| 403 | for (var = internalvars; var; var = var->next) |
| 404 | if (STREQ (var->name, name)) |
| 405 | return var; |
| 406 | |
| 407 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
| 408 | var->name = concat (name, NULL); |
| 409 | var->value = allocate_value (builtin_type_void); |
| 410 | release_value (var->value); |
| 411 | var->next = internalvars; |
| 412 | internalvars = var; |
| 413 | return var; |
| 414 | } |
| 415 | |
| 416 | value_ptr |
| 417 | value_of_internalvar (var) |
| 418 | struct internalvar *var; |
| 419 | { |
| 420 | register value_ptr val; |
| 421 | |
| 422 | #ifdef IS_TRAPPED_INTERNALVAR |
| 423 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 424 | return VALUE_OF_TRAPPED_INTERNALVAR (var); |
| 425 | #endif |
| 426 | |
| 427 | val = value_copy (var->value); |
| 428 | if (VALUE_LAZY (val)) |
| 429 | value_fetch_lazy (val); |
| 430 | VALUE_LVAL (val) = lval_internalvar; |
| 431 | VALUE_INTERNALVAR (val) = var; |
| 432 | return val; |
| 433 | } |
| 434 | |
| 435 | void |
| 436 | set_internalvar_component (var, offset, bitpos, bitsize, newval) |
| 437 | struct internalvar *var; |
| 438 | int offset, bitpos, bitsize; |
| 439 | value_ptr newval; |
| 440 | { |
| 441 | register char *addr = VALUE_CONTENTS (var->value) + offset; |
| 442 | |
| 443 | #ifdef IS_TRAPPED_INTERNALVAR |
| 444 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 445 | SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); |
| 446 | #endif |
| 447 | |
| 448 | if (bitsize) |
| 449 | modify_field (addr, value_as_long (newval), |
| 450 | bitpos, bitsize); |
| 451 | else |
| 452 | memcpy (addr, VALUE_CONTENTS (newval), TYPE_LENGTH (VALUE_TYPE (newval))); |
| 453 | } |
| 454 | |
| 455 | void |
| 456 | set_internalvar (var, val) |
| 457 | struct internalvar *var; |
| 458 | value_ptr val; |
| 459 | { |
| 460 | value_ptr newval; |
| 461 | |
| 462 | #ifdef IS_TRAPPED_INTERNALVAR |
| 463 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 464 | SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); |
| 465 | #endif |
| 466 | |
| 467 | newval = value_copy (val); |
| 468 | newval->modifiable = 1; |
| 469 | |
| 470 | /* Force the value to be fetched from the target now, to avoid problems |
| 471 | later when this internalvar is referenced and the target is gone or |
| 472 | has changed. */ |
| 473 | if (VALUE_LAZY (newval)) |
| 474 | value_fetch_lazy (newval); |
| 475 | |
| 476 | /* Begin code which must not call error(). If var->value points to |
| 477 | something free'd, an error() obviously leaves a dangling pointer. |
| 478 | But we also get a danling pointer if var->value points to |
| 479 | something in the value chain (i.e., before release_value is |
| 480 | called), because after the error free_all_values will get called before |
| 481 | long. */ |
| 482 | free ((PTR)var->value); |
| 483 | var->value = newval; |
| 484 | release_value (newval); |
| 485 | /* End code which must not call error(). */ |
| 486 | } |
| 487 | |
| 488 | char * |
| 489 | internalvar_name (var) |
| 490 | struct internalvar *var; |
| 491 | { |
| 492 | return var->name; |
| 493 | } |
| 494 | |
| 495 | /* Free all internalvars. Done when new symtabs are loaded, |
| 496 | because that makes the values invalid. */ |
| 497 | |
| 498 | void |
| 499 | clear_internalvars () |
| 500 | { |
| 501 | register struct internalvar *var; |
| 502 | |
| 503 | while (internalvars) |
| 504 | { |
| 505 | var = internalvars; |
| 506 | internalvars = var->next; |
| 507 | free ((PTR)var->name); |
| 508 | free ((PTR)var->value); |
| 509 | free ((PTR)var); |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | static void |
| 514 | show_convenience (ignore, from_tty) |
| 515 | char *ignore; |
| 516 | int from_tty; |
| 517 | { |
| 518 | register struct internalvar *var; |
| 519 | int varseen = 0; |
| 520 | |
| 521 | for (var = internalvars; var; var = var->next) |
| 522 | { |
| 523 | #ifdef IS_TRAPPED_INTERNALVAR |
| 524 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 525 | continue; |
| 526 | #endif |
| 527 | if (!varseen) |
| 528 | { |
| 529 | varseen = 1; |
| 530 | } |
| 531 | printf_filtered ("$%s = ", var->name); |
| 532 | value_print (var->value, gdb_stdout, 0, Val_pretty_default); |
| 533 | printf_filtered ("\n"); |
| 534 | } |
| 535 | if (!varseen) |
| 536 | printf_unfiltered ("No debugger convenience variables now defined.\n\ |
| 537 | Convenience variables have names starting with \"$\";\n\ |
| 538 | use \"set\" as in \"set $foo = 5\" to define them.\n"); |
| 539 | } |
| 540 | \f |
| 541 | /* Extract a value as a C number (either long or double). |
| 542 | Knows how to convert fixed values to double, or |
| 543 | floating values to long. |
| 544 | Does not deallocate the value. */ |
| 545 | |
| 546 | LONGEST |
| 547 | value_as_long (val) |
| 548 | register value_ptr val; |
| 549 | { |
| 550 | /* This coerces arrays and functions, which is necessary (e.g. |
| 551 | in disassemble_command). It also dereferences references, which |
| 552 | I suspect is the most logical thing to do. */ |
| 553 | COERCE_ARRAY (val); |
| 554 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); |
| 555 | } |
| 556 | |
| 557 | DOUBLEST |
| 558 | value_as_double (val) |
| 559 | register value_ptr val; |
| 560 | { |
| 561 | DOUBLEST foo; |
| 562 | int inv; |
| 563 | |
| 564 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv); |
| 565 | if (inv) |
| 566 | error ("Invalid floating value found in program."); |
| 567 | return foo; |
| 568 | } |
| 569 | /* Extract a value as a C pointer. |
| 570 | Does not deallocate the value. */ |
| 571 | CORE_ADDR |
| 572 | value_as_pointer (val) |
| 573 | value_ptr val; |
| 574 | { |
| 575 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 576 | whether we want this to be true eventually. */ |
| 577 | #if 0 |
| 578 | /* ADDR_BITS_REMOVE is wrong if we are being called for a |
| 579 | non-address (e.g. argument to "signal", "info break", etc.), or |
| 580 | for pointers to char, in which the low bits *are* significant. */ |
| 581 | return ADDR_BITS_REMOVE(value_as_long (val)); |
| 582 | #else |
| 583 | return value_as_long (val); |
| 584 | #endif |
| 585 | } |
| 586 | \f |
| 587 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 588 | as a long, or as a double, assuming the raw data is described |
| 589 | by type TYPE. Knows how to convert different sizes of values |
| 590 | and can convert between fixed and floating point. We don't assume |
| 591 | any alignment for the raw data. Return value is in host byte order. |
| 592 | |
| 593 | If you want functions and arrays to be coerced to pointers, and |
| 594 | references to be dereferenced, call value_as_long() instead. |
| 595 | |
| 596 | C++: It is assumed that the front-end has taken care of |
| 597 | all matters concerning pointers to members. A pointer |
| 598 | to member which reaches here is considered to be equivalent |
| 599 | to an INT (or some size). After all, it is only an offset. */ |
| 600 | |
| 601 | LONGEST |
| 602 | unpack_long (type, valaddr) |
| 603 | struct type *type; |
| 604 | char *valaddr; |
| 605 | { |
| 606 | register enum type_code code = TYPE_CODE (type); |
| 607 | register int len = TYPE_LENGTH (type); |
| 608 | register int nosign = TYPE_UNSIGNED (type); |
| 609 | |
| 610 | if (current_language->la_language == language_scm |
| 611 | && is_scmvalue_type (type)) |
| 612 | return scm_unpack (type, valaddr, TYPE_CODE_INT); |
| 613 | |
| 614 | switch (code) |
| 615 | { |
| 616 | case TYPE_CODE_TYPEDEF: |
| 617 | return unpack_long (check_typedef (type), valaddr); |
| 618 | case TYPE_CODE_ENUM: |
| 619 | case TYPE_CODE_BOOL: |
| 620 | case TYPE_CODE_INT: |
| 621 | case TYPE_CODE_CHAR: |
| 622 | case TYPE_CODE_RANGE: |
| 623 | if (nosign) |
| 624 | return extract_unsigned_integer (valaddr, len); |
| 625 | else |
| 626 | return extract_signed_integer (valaddr, len); |
| 627 | |
| 628 | case TYPE_CODE_FLT: |
| 629 | return extract_floating (valaddr, len); |
| 630 | |
| 631 | case TYPE_CODE_PTR: |
| 632 | case TYPE_CODE_REF: |
| 633 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 634 | whether we want this to be true eventually. */ |
| 635 | return extract_address (valaddr, len); |
| 636 | |
| 637 | case TYPE_CODE_MEMBER: |
| 638 | error ("not implemented: member types in unpack_long"); |
| 639 | |
| 640 | default: |
| 641 | error ("Value can't be converted to integer."); |
| 642 | } |
| 643 | return 0; /* Placate lint. */ |
| 644 | } |
| 645 | |
| 646 | /* Return a double value from the specified type and address. |
| 647 | INVP points to an int which is set to 0 for valid value, |
| 648 | 1 for invalid value (bad float format). In either case, |
| 649 | the returned double is OK to use. Argument is in target |
| 650 | format, result is in host format. */ |
| 651 | |
| 652 | DOUBLEST |
| 653 | unpack_double (type, valaddr, invp) |
| 654 | struct type *type; |
| 655 | char *valaddr; |
| 656 | int *invp; |
| 657 | { |
| 658 | register enum type_code code = TYPE_CODE (type); |
| 659 | register int len = TYPE_LENGTH (type); |
| 660 | register int nosign = TYPE_UNSIGNED (type); |
| 661 | |
| 662 | *invp = 0; /* Assume valid. */ |
| 663 | CHECK_TYPEDEF (type); |
| 664 | if (code == TYPE_CODE_FLT) |
| 665 | { |
| 666 | #ifdef INVALID_FLOAT |
| 667 | if (INVALID_FLOAT (valaddr, len)) |
| 668 | { |
| 669 | *invp = 1; |
| 670 | return 1.234567891011121314; |
| 671 | } |
| 672 | #endif |
| 673 | return extract_floating (valaddr, len); |
| 674 | } |
| 675 | else if (nosign) |
| 676 | { |
| 677 | /* Unsigned -- be sure we compensate for signed LONGEST. */ |
| 678 | return (unsigned LONGEST) unpack_long (type, valaddr); |
| 679 | } |
| 680 | else |
| 681 | { |
| 682 | /* Signed -- we are OK with unpack_long. */ |
| 683 | return unpack_long (type, valaddr); |
| 684 | } |
| 685 | } |
| 686 | |
| 687 | /* Unpack raw data (copied from debugee, target byte order) at VALADDR |
| 688 | as a CORE_ADDR, assuming the raw data is described by type TYPE. |
| 689 | We don't assume any alignment for the raw data. Return value is in |
| 690 | host byte order. |
| 691 | |
| 692 | If you want functions and arrays to be coerced to pointers, and |
| 693 | references to be dereferenced, call value_as_pointer() instead. |
| 694 | |
| 695 | C++: It is assumed that the front-end has taken care of |
| 696 | all matters concerning pointers to members. A pointer |
| 697 | to member which reaches here is considered to be equivalent |
| 698 | to an INT (or some size). After all, it is only an offset. */ |
| 699 | |
| 700 | CORE_ADDR |
| 701 | unpack_pointer (type, valaddr) |
| 702 | struct type *type; |
| 703 | char *valaddr; |
| 704 | { |
| 705 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 706 | whether we want this to be true eventually. */ |
| 707 | return unpack_long (type, valaddr); |
| 708 | } |
| 709 | \f |
| 710 | /* Given a value ARG1 (offset by OFFSET bytes) |
| 711 | of a struct or union type ARG_TYPE, |
| 712 | extract and return the value of one of its fields. |
| 713 | FIELDNO says which field. |
| 714 | |
| 715 | For C++, must also be able to return values from static fields */ |
| 716 | |
| 717 | value_ptr |
| 718 | value_primitive_field (arg1, offset, fieldno, arg_type) |
| 719 | register value_ptr arg1; |
| 720 | int offset; |
| 721 | register int fieldno; |
| 722 | register struct type *arg_type; |
| 723 | { |
| 724 | register value_ptr v; |
| 725 | register struct type *type; |
| 726 | |
| 727 | CHECK_TYPEDEF (arg_type); |
| 728 | type = TYPE_FIELD_TYPE (arg_type, fieldno); |
| 729 | |
| 730 | /* Handle packed fields */ |
| 731 | |
| 732 | offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; |
| 733 | if (TYPE_FIELD_BITSIZE (arg_type, fieldno)) |
| 734 | { |
| 735 | v = value_from_longest (type, |
| 736 | unpack_field_as_long (arg_type, |
| 737 | VALUE_CONTENTS (arg1), |
| 738 | fieldno)); |
| 739 | VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8; |
| 740 | VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (arg_type, fieldno); |
| 741 | } |
| 742 | else |
| 743 | { |
| 744 | v = allocate_value (type); |
| 745 | if (VALUE_LAZY (arg1)) |
| 746 | VALUE_LAZY (v) = 1; |
| 747 | else |
| 748 | memcpy (VALUE_CONTENTS_RAW (v), VALUE_CONTENTS_RAW (arg1) + offset, |
| 749 | TYPE_LENGTH (type)); |
| 750 | } |
| 751 | VALUE_LVAL (v) = VALUE_LVAL (arg1); |
| 752 | if (VALUE_LVAL (arg1) == lval_internalvar) |
| 753 | VALUE_LVAL (v) = lval_internalvar_component; |
| 754 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); |
| 755 | VALUE_OFFSET (v) = offset + VALUE_OFFSET (arg1); |
| 756 | return v; |
| 757 | } |
| 758 | |
| 759 | /* Given a value ARG1 of a struct or union type, |
| 760 | extract and return the value of one of its fields. |
| 761 | FIELDNO says which field. |
| 762 | |
| 763 | For C++, must also be able to return values from static fields */ |
| 764 | |
| 765 | value_ptr |
| 766 | value_field (arg1, fieldno) |
| 767 | register value_ptr arg1; |
| 768 | register int fieldno; |
| 769 | { |
| 770 | return value_primitive_field (arg1, 0, fieldno, VALUE_TYPE (arg1)); |
| 771 | } |
| 772 | |
| 773 | /* Return a non-virtual function as a value. |
| 774 | F is the list of member functions which contains the desired method. |
| 775 | J is an index into F which provides the desired method. */ |
| 776 | |
| 777 | value_ptr |
| 778 | value_fn_field (arg1p, f, j, type, offset) |
| 779 | value_ptr *arg1p; |
| 780 | struct fn_field *f; |
| 781 | int j; |
| 782 | struct type *type; |
| 783 | int offset; |
| 784 | { |
| 785 | register value_ptr v; |
| 786 | register struct type *ftype = TYPE_FN_FIELD_TYPE (f, j); |
| 787 | struct symbol *sym; |
| 788 | |
| 789 | sym = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j), |
| 790 | 0, VAR_NAMESPACE, 0, NULL); |
| 791 | if (! sym) |
| 792 | return NULL; |
| 793 | /* |
| 794 | error ("Internal error: could not find physical method named %s", |
| 795 | TYPE_FN_FIELD_PHYSNAME (f, j)); |
| 796 | */ |
| 797 | |
| 798 | v = allocate_value (ftype); |
| 799 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); |
| 800 | VALUE_TYPE (v) = ftype; |
| 801 | |
| 802 | if (arg1p) |
| 803 | { |
| 804 | if (type != VALUE_TYPE (*arg1p)) |
| 805 | *arg1p = value_ind (value_cast (lookup_pointer_type (type), |
| 806 | value_addr (*arg1p))); |
| 807 | |
| 808 | /* Move the `this' pointer according to the offset. |
| 809 | VALUE_OFFSET (*arg1p) += offset; |
| 810 | */ |
| 811 | } |
| 812 | |
| 813 | return v; |
| 814 | } |
| 815 | |
| 816 | /* Return a virtual function as a value. |
| 817 | ARG1 is the object which provides the virtual function |
| 818 | table pointer. *ARG1P is side-effected in calling this function. |
| 819 | F is the list of member functions which contains the desired virtual |
| 820 | function. |
| 821 | J is an index into F which provides the desired virtual function. |
| 822 | |
| 823 | TYPE is the type in which F is located. */ |
| 824 | value_ptr |
| 825 | value_virtual_fn_field (arg1p, f, j, type, offset) |
| 826 | value_ptr *arg1p; |
| 827 | struct fn_field *f; |
| 828 | int j; |
| 829 | struct type *type; |
| 830 | int offset; |
| 831 | { |
| 832 | value_ptr arg1 = *arg1p; |
| 833 | struct type *type1 = check_typedef (VALUE_TYPE (arg1)); |
| 834 | struct type *entry_type; |
| 835 | /* First, get the virtual function table pointer. That comes |
| 836 | with a strange type, so cast it to type `pointer to long' (which |
| 837 | should serve just fine as a function type). Then, index into |
| 838 | the table, and convert final value to appropriate function type. */ |
| 839 | value_ptr entry, vfn, vtbl; |
| 840 | value_ptr vi = value_from_longest (builtin_type_int, |
| 841 | (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j)); |
| 842 | struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j); |
| 843 | struct type *context; |
| 844 | if (fcontext == NULL) |
| 845 | /* We don't have an fcontext (e.g. the program was compiled with |
| 846 | g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE. |
| 847 | This won't work right for multiple inheritance, but at least we |
| 848 | should do as well as GDB 3.x did. */ |
| 849 | fcontext = TYPE_VPTR_BASETYPE (type); |
| 850 | context = lookup_pointer_type (fcontext); |
| 851 | /* Now context is a pointer to the basetype containing the vtbl. */ |
| 852 | if (TYPE_TARGET_TYPE (context) != type1) |
| 853 | { |
| 854 | arg1 = value_ind (value_cast (context, value_addr (arg1))); |
| 855 | type1 = check_typedef (VALUE_TYPE (arg1)); |
| 856 | } |
| 857 | |
| 858 | context = type1; |
| 859 | /* Now context is the basetype containing the vtbl. */ |
| 860 | |
| 861 | /* This type may have been defined before its virtual function table |
| 862 | was. If so, fill in the virtual function table entry for the |
| 863 | type now. */ |
| 864 | if (TYPE_VPTR_FIELDNO (context) < 0) |
| 865 | fill_in_vptr_fieldno (context); |
| 866 | |
| 867 | /* The virtual function table is now an array of structures |
| 868 | which have the form { int16 offset, delta; void *pfn; }. */ |
| 869 | vtbl = value_ind (value_primitive_field (arg1, 0, |
| 870 | TYPE_VPTR_FIELDNO (context), |
| 871 | TYPE_VPTR_BASETYPE (context))); |
| 872 | |
| 873 | /* Index into the virtual function table. This is hard-coded because |
| 874 | looking up a field is not cheap, and it may be important to save |
| 875 | time, e.g. if the user has set a conditional breakpoint calling |
| 876 | a virtual function. */ |
| 877 | entry = value_subscript (vtbl, vi); |
| 878 | entry_type = check_typedef (VALUE_TYPE (entry)); |
| 879 | |
| 880 | if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT) |
| 881 | { |
| 882 | /* Move the `this' pointer according to the virtual function table. */ |
| 883 | VALUE_OFFSET (arg1) += value_as_long (value_field (entry, 0)); |
| 884 | |
| 885 | if (! VALUE_LAZY (arg1)) |
| 886 | { |
| 887 | VALUE_LAZY (arg1) = 1; |
| 888 | value_fetch_lazy (arg1); |
| 889 | } |
| 890 | |
| 891 | vfn = value_field (entry, 2); |
| 892 | } |
| 893 | else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR) |
| 894 | vfn = entry; |
| 895 | else |
| 896 | error ("I'm confused: virtual function table has bad type"); |
| 897 | /* Reinstantiate the function pointer with the correct type. */ |
| 898 | VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)); |
| 899 | |
| 900 | *arg1p = arg1; |
| 901 | return vfn; |
| 902 | } |
| 903 | |
| 904 | /* ARG is a pointer to an object we know to be at least |
| 905 | a DTYPE. BTYPE is the most derived basetype that has |
| 906 | already been searched (and need not be searched again). |
| 907 | After looking at the vtables between BTYPE and DTYPE, |
| 908 | return the most derived type we find. The caller must |
| 909 | be satisfied when the return value == DTYPE. |
| 910 | |
| 911 | FIXME-tiemann: should work with dossier entries as well. */ |
| 912 | |
| 913 | static value_ptr |
| 914 | value_headof (in_arg, btype, dtype) |
| 915 | value_ptr in_arg; |
| 916 | struct type *btype, *dtype; |
| 917 | { |
| 918 | /* First collect the vtables we must look at for this object. */ |
| 919 | /* FIXME-tiemann: right now, just look at top-most vtable. */ |
| 920 | value_ptr arg, vtbl, entry, best_entry = 0; |
| 921 | int i, nelems; |
| 922 | int offset, best_offset = 0; |
| 923 | struct symbol *sym; |
| 924 | CORE_ADDR pc_for_sym; |
| 925 | char *demangled_name; |
| 926 | struct minimal_symbol *msymbol; |
| 927 | |
| 928 | btype = TYPE_VPTR_BASETYPE (dtype); |
| 929 | CHECK_TYPEDEF (btype); |
| 930 | arg = in_arg; |
| 931 | if (btype != dtype) |
| 932 | arg = value_cast (lookup_pointer_type (btype), arg); |
| 933 | vtbl = value_ind (value_field (value_ind (arg), TYPE_VPTR_FIELDNO (btype))); |
| 934 | |
| 935 | /* Check that VTBL looks like it points to a virtual function table. */ |
| 936 | msymbol = lookup_minimal_symbol_by_pc (VALUE_ADDRESS (vtbl)); |
| 937 | if (msymbol == NULL |
| 938 | || (demangled_name = SYMBOL_NAME (msymbol)) == NULL |
| 939 | || !VTBL_PREFIX_P (demangled_name)) |
| 940 | { |
| 941 | /* If we expected to find a vtable, but did not, let the user |
| 942 | know that we aren't happy, but don't throw an error. |
| 943 | FIXME: there has to be a better way to do this. */ |
| 944 | struct type *error_type = (struct type *)xmalloc (sizeof (struct type)); |
| 945 | memcpy (error_type, VALUE_TYPE (in_arg), sizeof (struct type)); |
| 946 | TYPE_NAME (error_type) = savestring ("suspicious *", sizeof ("suspicious *")); |
| 947 | VALUE_TYPE (in_arg) = error_type; |
| 948 | return in_arg; |
| 949 | } |
| 950 | |
| 951 | /* Now search through the virtual function table. */ |
| 952 | entry = value_ind (vtbl); |
| 953 | nelems = longest_to_int (value_as_long (value_field (entry, 2))); |
| 954 | for (i = 1; i <= nelems; i++) |
| 955 | { |
| 956 | entry = value_subscript (vtbl, value_from_longest (builtin_type_int, |
| 957 | (LONGEST) i)); |
| 958 | /* This won't work if we're using thunks. */ |
| 959 | if (TYPE_CODE (check_typedef (VALUE_TYPE (entry))) != TYPE_CODE_STRUCT) |
| 960 | break; |
| 961 | offset = longest_to_int (value_as_long (value_field (entry, 0))); |
| 962 | /* If we use '<=' we can handle single inheritance |
| 963 | * where all offsets are zero - just use the first entry found. */ |
| 964 | if (offset <= best_offset) |
| 965 | { |
| 966 | best_offset = offset; |
| 967 | best_entry = entry; |
| 968 | } |
| 969 | } |
| 970 | /* Move the pointer according to BEST_ENTRY's offset, and figure |
| 971 | out what type we should return as the new pointer. */ |
| 972 | if (best_entry == 0) |
| 973 | { |
| 974 | /* An alternative method (which should no longer be necessary). |
| 975 | * But we leave it in for future use, when we will hopefully |
| 976 | * have optimizes the vtable to use thunks instead of offsets. */ |
| 977 | /* Use the name of vtable itself to extract a base type. */ |
| 978 | demangled_name += 4; /* Skip _vt$ prefix. */ |
| 979 | } |
| 980 | else |
| 981 | { |
| 982 | pc_for_sym = value_as_pointer (value_field (best_entry, 2)); |
| 983 | sym = find_pc_function (pc_for_sym); |
| 984 | demangled_name = cplus_demangle (SYMBOL_NAME (sym), DMGL_ANSI); |
| 985 | *(strchr (demangled_name, ':')) = '\0'; |
| 986 | } |
| 987 | sym = lookup_symbol (demangled_name, 0, VAR_NAMESPACE, 0, 0); |
| 988 | if (sym == NULL) |
| 989 | error ("could not find type declaration for `%s'", demangled_name); |
| 990 | if (best_entry) |
| 991 | { |
| 992 | free (demangled_name); |
| 993 | arg = value_add (value_cast (builtin_type_int, arg), |
| 994 | value_field (best_entry, 0)); |
| 995 | } |
| 996 | else arg = in_arg; |
| 997 | VALUE_TYPE (arg) = lookup_pointer_type (SYMBOL_TYPE (sym)); |
| 998 | return arg; |
| 999 | } |
| 1000 | |
| 1001 | /* ARG is a pointer object of type TYPE. If TYPE has virtual |
| 1002 | function tables, probe ARG's tables (including the vtables |
| 1003 | of its baseclasses) to figure out the most derived type that ARG |
| 1004 | could actually be a pointer to. */ |
| 1005 | |
| 1006 | value_ptr |
| 1007 | value_from_vtable_info (arg, type) |
| 1008 | value_ptr arg; |
| 1009 | struct type *type; |
| 1010 | { |
| 1011 | /* Take care of preliminaries. */ |
| 1012 | if (TYPE_VPTR_FIELDNO (type) < 0) |
| 1013 | fill_in_vptr_fieldno (type); |
| 1014 | if (TYPE_VPTR_FIELDNO (type) < 0) |
| 1015 | return 0; |
| 1016 | |
| 1017 | return value_headof (arg, 0, type); |
| 1018 | } |
| 1019 | |
| 1020 | /* Return true if the INDEXth field of TYPE is a virtual baseclass |
| 1021 | pointer which is for the base class whose type is BASECLASS. */ |
| 1022 | |
| 1023 | static int |
| 1024 | vb_match (type, index, basetype) |
| 1025 | struct type *type; |
| 1026 | int index; |
| 1027 | struct type *basetype; |
| 1028 | { |
| 1029 | struct type *fieldtype; |
| 1030 | char *name = TYPE_FIELD_NAME (type, index); |
| 1031 | char *field_class_name = NULL; |
| 1032 | |
| 1033 | if (*name != '_') |
| 1034 | return 0; |
| 1035 | /* gcc 2.4 uses _vb$. */ |
| 1036 | if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3])) |
| 1037 | field_class_name = name + 4; |
| 1038 | /* gcc 2.5 will use __vb_. */ |
| 1039 | if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_') |
| 1040 | field_class_name = name + 5; |
| 1041 | |
| 1042 | if (field_class_name == NULL) |
| 1043 | /* This field is not a virtual base class pointer. */ |
| 1044 | return 0; |
| 1045 | |
| 1046 | /* It's a virtual baseclass pointer, now we just need to find out whether |
| 1047 | it is for this baseclass. */ |
| 1048 | fieldtype = TYPE_FIELD_TYPE (type, index); |
| 1049 | if (fieldtype == NULL |
| 1050 | || TYPE_CODE (fieldtype) != TYPE_CODE_PTR) |
| 1051 | /* "Can't happen". */ |
| 1052 | return 0; |
| 1053 | |
| 1054 | /* What we check for is that either the types are equal (needed for |
| 1055 | nameless types) or have the same name. This is ugly, and a more |
| 1056 | elegant solution should be devised (which would probably just push |
| 1057 | the ugliness into symbol reading unless we change the stabs format). */ |
| 1058 | if (TYPE_TARGET_TYPE (fieldtype) == basetype) |
| 1059 | return 1; |
| 1060 | |
| 1061 | if (TYPE_NAME (basetype) != NULL |
| 1062 | && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL |
| 1063 | && STREQ (TYPE_NAME (basetype), |
| 1064 | TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)))) |
| 1065 | return 1; |
| 1066 | return 0; |
| 1067 | } |
| 1068 | |
| 1069 | /* Compute the offset of the baseclass which is |
| 1070 | the INDEXth baseclass of class TYPE, |
| 1071 | for value at VALADDR (in host) at ADDRESS (in target). |
| 1072 | The result is the offset of the baseclass value relative |
| 1073 | to (the address of)(ARG) + OFFSET. |
| 1074 | |
| 1075 | -1 is returned on error. */ |
| 1076 | |
| 1077 | int |
| 1078 | baseclass_offset (type, index, valaddr, address) |
| 1079 | struct type *type; |
| 1080 | int index; |
| 1081 | char *valaddr; |
| 1082 | CORE_ADDR address; |
| 1083 | { |
| 1084 | struct type *basetype = TYPE_BASECLASS (type, index); |
| 1085 | |
| 1086 | if (BASETYPE_VIA_VIRTUAL (type, index)) |
| 1087 | { |
| 1088 | /* Must hunt for the pointer to this virtual baseclass. */ |
| 1089 | register int i, len = TYPE_NFIELDS (type); |
| 1090 | register int n_baseclasses = TYPE_N_BASECLASSES (type); |
| 1091 | |
| 1092 | /* First look for the virtual baseclass pointer |
| 1093 | in the fields. */ |
| 1094 | for (i = n_baseclasses; i < len; i++) |
| 1095 | { |
| 1096 | if (vb_match (type, i, basetype)) |
| 1097 | { |
| 1098 | CORE_ADDR addr |
| 1099 | = unpack_pointer (TYPE_FIELD_TYPE (type, i), |
| 1100 | valaddr + (TYPE_FIELD_BITPOS (type, i) / 8)); |
| 1101 | |
| 1102 | return addr - (LONGEST) address; |
| 1103 | } |
| 1104 | } |
| 1105 | /* Not in the fields, so try looking through the baseclasses. */ |
| 1106 | for (i = index+1; i < n_baseclasses; i++) |
| 1107 | { |
| 1108 | int boffset = |
| 1109 | baseclass_offset (type, i, valaddr, address); |
| 1110 | if (boffset) |
| 1111 | return boffset; |
| 1112 | } |
| 1113 | /* Not found. */ |
| 1114 | return -1; |
| 1115 | } |
| 1116 | |
| 1117 | /* Baseclass is easily computed. */ |
| 1118 | return TYPE_BASECLASS_BITPOS (type, index) / 8; |
| 1119 | } |
| 1120 | \f |
| 1121 | /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at |
| 1122 | VALADDR. |
| 1123 | |
| 1124 | Extracting bits depends on endianness of the machine. Compute the |
| 1125 | number of least significant bits to discard. For big endian machines, |
| 1126 | we compute the total number of bits in the anonymous object, subtract |
| 1127 | off the bit count from the MSB of the object to the MSB of the |
| 1128 | bitfield, then the size of the bitfield, which leaves the LSB discard |
| 1129 | count. For little endian machines, the discard count is simply the |
| 1130 | number of bits from the LSB of the anonymous object to the LSB of the |
| 1131 | bitfield. |
| 1132 | |
| 1133 | If the field is signed, we also do sign extension. */ |
| 1134 | |
| 1135 | LONGEST |
| 1136 | unpack_field_as_long (type, valaddr, fieldno) |
| 1137 | struct type *type; |
| 1138 | char *valaddr; |
| 1139 | int fieldno; |
| 1140 | { |
| 1141 | unsigned LONGEST val; |
| 1142 | unsigned LONGEST valmask; |
| 1143 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); |
| 1144 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); |
| 1145 | int lsbcount; |
| 1146 | |
| 1147 | val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val)); |
| 1148 | |
| 1149 | /* Extract bits. See comment above. */ |
| 1150 | |
| 1151 | if (BITS_BIG_ENDIAN) |
| 1152 | lsbcount = (sizeof val * 8 - bitpos % 8 - bitsize); |
| 1153 | else |
| 1154 | lsbcount = (bitpos % 8); |
| 1155 | val >>= lsbcount; |
| 1156 | |
| 1157 | /* If the field does not entirely fill a LONGEST, then zero the sign bits. |
| 1158 | If the field is signed, and is negative, then sign extend. */ |
| 1159 | |
| 1160 | if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val))) |
| 1161 | { |
| 1162 | valmask = (((unsigned LONGEST) 1) << bitsize) - 1; |
| 1163 | val &= valmask; |
| 1164 | if (!TYPE_UNSIGNED (TYPE_FIELD_TYPE (type, fieldno))) |
| 1165 | { |
| 1166 | if (val & (valmask ^ (valmask >> 1))) |
| 1167 | { |
| 1168 | val |= ~valmask; |
| 1169 | } |
| 1170 | } |
| 1171 | } |
| 1172 | return (val); |
| 1173 | } |
| 1174 | |
| 1175 | /* Modify the value of a bitfield. ADDR points to a block of memory in |
| 1176 | target byte order; the bitfield starts in the byte pointed to. FIELDVAL |
| 1177 | is the desired value of the field, in host byte order. BITPOS and BITSIZE |
| 1178 | indicate which bits (in target bit order) comprise the bitfield. */ |
| 1179 | |
| 1180 | void |
| 1181 | modify_field (addr, fieldval, bitpos, bitsize) |
| 1182 | char *addr; |
| 1183 | LONGEST fieldval; |
| 1184 | int bitpos, bitsize; |
| 1185 | { |
| 1186 | LONGEST oword; |
| 1187 | |
| 1188 | /* If a negative fieldval fits in the field in question, chop |
| 1189 | off the sign extension bits. */ |
| 1190 | if (bitsize < (8 * (int) sizeof (fieldval)) |
| 1191 | && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) |
| 1192 | fieldval = fieldval & ((1 << bitsize) - 1); |
| 1193 | |
| 1194 | /* Warn if value is too big to fit in the field in question. */ |
| 1195 | if (bitsize < (8 * (int) sizeof (fieldval)) |
| 1196 | && 0 != (fieldval & ~((1<<bitsize)-1))) |
| 1197 | { |
| 1198 | /* FIXME: would like to include fieldval in the message, but |
| 1199 | we don't have a sprintf_longest. */ |
| 1200 | warning ("Value does not fit in %d bits.", bitsize); |
| 1201 | |
| 1202 | /* Truncate it, otherwise adjoining fields may be corrupted. */ |
| 1203 | fieldval = fieldval & ((1 << bitsize) - 1); |
| 1204 | } |
| 1205 | |
| 1206 | oword = extract_signed_integer (addr, sizeof oword); |
| 1207 | |
| 1208 | /* Shifting for bit field depends on endianness of the target machine. */ |
| 1209 | if (BITS_BIG_ENDIAN) |
| 1210 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; |
| 1211 | |
| 1212 | /* Mask out old value, while avoiding shifts >= size of oword */ |
| 1213 | if (bitsize < 8 * (int) sizeof (oword)) |
| 1214 | oword &= ~(((((unsigned LONGEST)1) << bitsize) - 1) << bitpos); |
| 1215 | else |
| 1216 | oword &= ~((~(unsigned LONGEST)0) << bitpos); |
| 1217 | oword |= fieldval << bitpos; |
| 1218 | |
| 1219 | store_signed_integer (addr, sizeof oword, oword); |
| 1220 | } |
| 1221 | \f |
| 1222 | /* Convert C numbers into newly allocated values */ |
| 1223 | |
| 1224 | value_ptr |
| 1225 | value_from_longest (type, num) |
| 1226 | struct type *type; |
| 1227 | register LONGEST num; |
| 1228 | { |
| 1229 | register value_ptr val = allocate_value (type); |
| 1230 | register enum type_code code; |
| 1231 | register int len; |
| 1232 | retry: |
| 1233 | code = TYPE_CODE (type); |
| 1234 | len = TYPE_LENGTH (type); |
| 1235 | |
| 1236 | switch (code) |
| 1237 | { |
| 1238 | case TYPE_CODE_TYPEDEF: |
| 1239 | type = check_typedef (type); |
| 1240 | goto retry; |
| 1241 | case TYPE_CODE_INT: |
| 1242 | case TYPE_CODE_CHAR: |
| 1243 | case TYPE_CODE_ENUM: |
| 1244 | case TYPE_CODE_BOOL: |
| 1245 | case TYPE_CODE_RANGE: |
| 1246 | store_signed_integer (VALUE_CONTENTS_RAW (val), len, num); |
| 1247 | break; |
| 1248 | |
| 1249 | case TYPE_CODE_REF: |
| 1250 | case TYPE_CODE_PTR: |
| 1251 | /* This assumes that all pointers of a given length |
| 1252 | have the same form. */ |
| 1253 | store_address (VALUE_CONTENTS_RAW (val), len, (CORE_ADDR) num); |
| 1254 | break; |
| 1255 | |
| 1256 | default: |
| 1257 | error ("Unexpected type encountered for integer constant."); |
| 1258 | } |
| 1259 | return val; |
| 1260 | } |
| 1261 | |
| 1262 | value_ptr |
| 1263 | value_from_double (type, num) |
| 1264 | struct type *type; |
| 1265 | DOUBLEST num; |
| 1266 | { |
| 1267 | register value_ptr val = allocate_value (type); |
| 1268 | struct type *base_type = check_typedef (type); |
| 1269 | register enum type_code code = TYPE_CODE (base_type); |
| 1270 | register int len = TYPE_LENGTH (base_type); |
| 1271 | |
| 1272 | if (code == TYPE_CODE_FLT) |
| 1273 | { |
| 1274 | store_floating (VALUE_CONTENTS_RAW (val), len, num); |
| 1275 | } |
| 1276 | else |
| 1277 | error ("Unexpected type encountered for floating constant."); |
| 1278 | |
| 1279 | return val; |
| 1280 | } |
| 1281 | \f |
| 1282 | /* Deal with the value that is "about to be returned". */ |
| 1283 | |
| 1284 | /* Return the value that a function returning now |
| 1285 | would be returning to its caller, assuming its type is VALTYPE. |
| 1286 | RETBUF is where we look for what ought to be the contents |
| 1287 | of the registers (in raw form). This is because it is often |
| 1288 | desirable to restore old values to those registers |
| 1289 | after saving the contents of interest, and then call |
| 1290 | this function using the saved values. |
| 1291 | struct_return is non-zero when the function in question is |
| 1292 | using the structure return conventions on the machine in question; |
| 1293 | 0 when it is using the value returning conventions (this often |
| 1294 | means returning pointer to where structure is vs. returning value). */ |
| 1295 | |
| 1296 | value_ptr |
| 1297 | value_being_returned (valtype, retbuf, struct_return) |
| 1298 | register struct type *valtype; |
| 1299 | char retbuf[REGISTER_BYTES]; |
| 1300 | int struct_return; |
| 1301 | /*ARGSUSED*/ |
| 1302 | { |
| 1303 | register value_ptr val; |
| 1304 | CORE_ADDR addr; |
| 1305 | |
| 1306 | #if defined (EXTRACT_STRUCT_VALUE_ADDRESS) |
| 1307 | /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */ |
| 1308 | if (struct_return) { |
| 1309 | addr = EXTRACT_STRUCT_VALUE_ADDRESS (retbuf); |
| 1310 | if (!addr) |
| 1311 | error ("Function return value unknown"); |
| 1312 | return value_at (valtype, addr); |
| 1313 | } |
| 1314 | #endif |
| 1315 | |
| 1316 | val = allocate_value (valtype); |
| 1317 | CHECK_TYPEDEF (valtype); |
| 1318 | EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS_RAW (val)); |
| 1319 | |
| 1320 | return val; |
| 1321 | } |
| 1322 | |
| 1323 | /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of |
| 1324 | EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc |
| 1325 | and TYPE is the type (which is known to be struct, union or array). |
| 1326 | |
| 1327 | On most machines, the struct convention is used unless we are |
| 1328 | using gcc and the type is of a special size. */ |
| 1329 | /* As of about 31 Mar 93, GCC was changed to be compatible with the |
| 1330 | native compiler. GCC 2.3.3 was the last release that did it the |
| 1331 | old way. Since gcc2_compiled was not changed, we have no |
| 1332 | way to correctly win in all cases, so we just do the right thing |
| 1333 | for gcc1 and for gcc2 after this change. Thus it loses for gcc |
| 1334 | 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled |
| 1335 | would cause more chaos than dealing with some struct returns being |
| 1336 | handled wrong. */ |
| 1337 | #if !defined (USE_STRUCT_CONVENTION) |
| 1338 | #define USE_STRUCT_CONVENTION(gcc_p, type)\ |
| 1339 | (!((gcc_p == 1) && (TYPE_LENGTH (value_type) == 1 \ |
| 1340 | || TYPE_LENGTH (value_type) == 2 \ |
| 1341 | || TYPE_LENGTH (value_type) == 4 \ |
| 1342 | || TYPE_LENGTH (value_type) == 8 \ |
| 1343 | ) \ |
| 1344 | )) |
| 1345 | #endif |
| 1346 | |
| 1347 | /* Some fundamental types (such as long double) are returned on the stack for |
| 1348 | certain architectures. This macro should return true for any type besides |
| 1349 | struct, union or array that gets returned on the stack. */ |
| 1350 | |
| 1351 | #ifndef RETURN_VALUE_ON_STACK |
| 1352 | #define RETURN_VALUE_ON_STACK(TYPE) 0 |
| 1353 | #endif |
| 1354 | |
| 1355 | /* Return true if the function specified is using the structure returning |
| 1356 | convention on this machine to return arguments, or 0 if it is using |
| 1357 | the value returning convention. FUNCTION is the value representing |
| 1358 | the function, FUNCADDR is the address of the function, and VALUE_TYPE |
| 1359 | is the type returned by the function. GCC_P is nonzero if compiled |
| 1360 | with GCC. */ |
| 1361 | |
| 1362 | int |
| 1363 | using_struct_return (function, funcaddr, value_type, gcc_p) |
| 1364 | value_ptr function; |
| 1365 | CORE_ADDR funcaddr; |
| 1366 | struct type *value_type; |
| 1367 | int gcc_p; |
| 1368 | /*ARGSUSED*/ |
| 1369 | { |
| 1370 | register enum type_code code = TYPE_CODE (value_type); |
| 1371 | |
| 1372 | if (code == TYPE_CODE_ERROR) |
| 1373 | error ("Function return type unknown."); |
| 1374 | |
| 1375 | if (code == TYPE_CODE_STRUCT |
| 1376 | || code == TYPE_CODE_UNION |
| 1377 | || code == TYPE_CODE_ARRAY |
| 1378 | || RETURN_VALUE_ON_STACK (value_type)) |
| 1379 | return USE_STRUCT_CONVENTION (gcc_p, value_type); |
| 1380 | |
| 1381 | return 0; |
| 1382 | } |
| 1383 | |
| 1384 | /* Store VAL so it will be returned if a function returns now. |
| 1385 | Does not verify that VAL's type matches what the current |
| 1386 | function wants to return. */ |
| 1387 | |
| 1388 | void |
| 1389 | set_return_value (val) |
| 1390 | value_ptr val; |
| 1391 | { |
| 1392 | struct type *type = check_typedef (VALUE_TYPE (val)); |
| 1393 | register enum type_code code = TYPE_CODE (type); |
| 1394 | |
| 1395 | if (code == TYPE_CODE_ERROR) |
| 1396 | error ("Function return type unknown."); |
| 1397 | |
| 1398 | if ( code == TYPE_CODE_STRUCT |
| 1399 | || code == TYPE_CODE_UNION) /* FIXME, implement struct return. */ |
| 1400 | error ("GDB does not support specifying a struct or union return value."); |
| 1401 | |
| 1402 | STORE_RETURN_VALUE (type, VALUE_CONTENTS (val)); |
| 1403 | } |
| 1404 | \f |
| 1405 | void |
| 1406 | _initialize_values () |
| 1407 | { |
| 1408 | add_cmd ("convenience", no_class, show_convenience, |
| 1409 | "Debugger convenience (\"$foo\") variables.\n\ |
| 1410 | These variables are created when you assign them values;\n\ |
| 1411 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ |
| 1412 | A few convenience variables are given values automatically:\n\ |
| 1413 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ |
| 1414 | \"$__\" holds the contents of the last address examined with \"x\".", |
| 1415 | &showlist); |
| 1416 | |
| 1417 | add_cmd ("values", no_class, show_values, |
| 1418 | "Elements of value history around item number IDX (or last ten).", |
| 1419 | &showlist); |
| 1420 | } |