| 1 | /*- |
| 2 | * This code is derived from software copyrighted by the Free Software |
| 3 | * Foundation. |
| 4 | * |
| 5 | * Modified 1991 by Donn Seeley at UUNET Technologies, Inc. |
| 6 | * Modified 1990 by Van Jacobson at Lawrence Berkeley Laboratory. |
| 7 | */ |
| 8 | |
| 9 | #ifndef lint |
| 10 | static char sccsid[] = "@(#)values.c 6.3 (Berkeley) 5/8/91"; |
| 11 | #endif /* not lint */ |
| 12 | |
| 13 | /* Low level packing and unpacking of values for GDB. |
| 14 | Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc. |
| 15 | |
| 16 | This file is part of GDB. |
| 17 | |
| 18 | GDB is free software; you can redistribute it and/or modify |
| 19 | it under the terms of the GNU General Public License as published by |
| 20 | the Free Software Foundation; either version 1, or (at your option) |
| 21 | any later version. |
| 22 | |
| 23 | GDB is distributed in the hope that it will be useful, |
| 24 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 25 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 26 | GNU General Public License for more details. |
| 27 | |
| 28 | You should have received a copy of the GNU General Public License |
| 29 | along with GDB; see the file COPYING. If not, write to |
| 30 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 31 | |
| 32 | #include <stdio.h> |
| 33 | #include "defs.h" |
| 34 | #include "param.h" |
| 35 | #include "symtab.h" |
| 36 | #include "value.h" |
| 37 | |
| 38 | /* The value-history records all the values printed |
| 39 | by print commands during this session. Each chunk |
| 40 | records 60 consecutive values. The first chunk on |
| 41 | the chain records the most recent values. |
| 42 | The total number of values is in value_history_count. */ |
| 43 | |
| 44 | #define VALUE_HISTORY_CHUNK 60 |
| 45 | |
| 46 | struct value_history_chunk |
| 47 | { |
| 48 | struct value_history_chunk *next; |
| 49 | value values[VALUE_HISTORY_CHUNK]; |
| 50 | }; |
| 51 | |
| 52 | /* Chain of chunks now in use. */ |
| 53 | |
| 54 | static struct value_history_chunk *value_history_chain; |
| 55 | |
| 56 | static int value_history_count; /* Abs number of last entry stored */ |
| 57 | |
| 58 | \f |
| 59 | /* List of all value objects currently allocated |
| 60 | (except for those released by calls to release_value) |
| 61 | This is so they can be freed after each command. */ |
| 62 | |
| 63 | static value all_values; |
| 64 | |
| 65 | /* Allocate a value that has the correct length for type TYPE. */ |
| 66 | |
| 67 | value |
| 68 | allocate_value (type) |
| 69 | struct type *type; |
| 70 | { |
| 71 | register value val; |
| 72 | |
| 73 | /* If the type we want had no definition in the file it first |
| 74 | * appeared in, it will be marked a `stub'. The real definition |
| 75 | * probably appeared later so try to find it. */ |
| 76 | if (TYPE_FLAGS(type) & TYPE_FLAG_STUB) |
| 77 | { |
| 78 | register char *cp; |
| 79 | register struct symbol *sym; |
| 80 | extern char *index(); |
| 81 | |
| 82 | if (cp = index(TYPE_NAME(type), ' ')) |
| 83 | ++cp; |
| 84 | else |
| 85 | cp = TYPE_NAME(type); |
| 86 | |
| 87 | sym = lookup_symbol(cp, 0, STRUCT_NAMESPACE, 0); |
| 88 | |
| 89 | if (sym && TYPE_CODE(SYMBOL_TYPE(sym)) == TYPE_CODE(type)) |
| 90 | bcopy (SYMBOL_TYPE (sym), type, sizeof (*type)); |
| 91 | } |
| 92 | val = (value) xmalloc (sizeof (struct value) + TYPE_LENGTH (type)); |
| 93 | VALUE_NEXT (val) = all_values; |
| 94 | all_values = val; |
| 95 | VALUE_TYPE (val) = type; |
| 96 | VALUE_LVAL (val) = not_lval; |
| 97 | VALUE_ADDRESS (val) = 0; |
| 98 | VALUE_FRAME (val) = 0; |
| 99 | VALUE_OFFSET (val) = 0; |
| 100 | VALUE_BITPOS (val) = 0; |
| 101 | VALUE_BITSIZE (val) = 0; |
| 102 | VALUE_REPEATED (val) = 0; |
| 103 | VALUE_REPETITIONS (val) = 0; |
| 104 | VALUE_REGNO (val) = -1; |
| 105 | return val; |
| 106 | } |
| 107 | |
| 108 | /* Allocate a value that has the correct length |
| 109 | for COUNT repetitions type TYPE. */ |
| 110 | |
| 111 | value |
| 112 | allocate_repeat_value (type, count) |
| 113 | struct type *type; |
| 114 | int count; |
| 115 | { |
| 116 | register value val; |
| 117 | |
| 118 | val = (value) xmalloc (sizeof (struct value) + TYPE_LENGTH (type) * count); |
| 119 | VALUE_NEXT (val) = all_values; |
| 120 | all_values = val; |
| 121 | VALUE_TYPE (val) = type; |
| 122 | VALUE_LVAL (val) = not_lval; |
| 123 | VALUE_ADDRESS (val) = 0; |
| 124 | VALUE_FRAME (val) = 0; |
| 125 | VALUE_OFFSET (val) = 0; |
| 126 | VALUE_BITPOS (val) = 0; |
| 127 | VALUE_BITSIZE (val) = 0; |
| 128 | VALUE_REPEATED (val) = 1; |
| 129 | VALUE_REPETITIONS (val) = count; |
| 130 | VALUE_REGNO (val) = -1; |
| 131 | return val; |
| 132 | } |
| 133 | |
| 134 | /* Free all the values that have been allocated (except for those released). |
| 135 | Called after each command, successful or not. */ |
| 136 | |
| 137 | void |
| 138 | free_all_values () |
| 139 | { |
| 140 | register value val, next; |
| 141 | |
| 142 | for (val = all_values; val; val = next) |
| 143 | { |
| 144 | next = VALUE_NEXT (val); |
| 145 | free (val); |
| 146 | } |
| 147 | |
| 148 | all_values = 0; |
| 149 | } |
| 150 | |
| 151 | /* Remove VAL from the chain all_values |
| 152 | so it will not be freed automatically. */ |
| 153 | |
| 154 | void |
| 155 | release_value (val) |
| 156 | register value val; |
| 157 | { |
| 158 | register value v; |
| 159 | |
| 160 | if (all_values == val) |
| 161 | { |
| 162 | all_values = val->next; |
| 163 | return; |
| 164 | } |
| 165 | |
| 166 | for (v = all_values; v; v = v->next) |
| 167 | { |
| 168 | if (v->next == val) |
| 169 | { |
| 170 | v->next = val->next; |
| 171 | break; |
| 172 | } |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | /* Return a copy of the value ARG. |
| 177 | It contains the same contents, for same memory address, |
| 178 | but it's a different block of storage. */ |
| 179 | |
| 180 | static value |
| 181 | value_copy (arg) |
| 182 | value arg; |
| 183 | { |
| 184 | register value val; |
| 185 | register struct type *type = VALUE_TYPE (arg); |
| 186 | if (VALUE_REPEATED (arg)) |
| 187 | val = allocate_repeat_value (type, VALUE_REPETITIONS (arg)); |
| 188 | else |
| 189 | val = allocate_value (type); |
| 190 | VALUE_LVAL (val) = VALUE_LVAL (arg); |
| 191 | VALUE_ADDRESS (val) = VALUE_ADDRESS (arg); |
| 192 | VALUE_OFFSET (val) = VALUE_OFFSET (arg); |
| 193 | VALUE_BITPOS (val) = VALUE_BITPOS (arg); |
| 194 | VALUE_BITSIZE (val) = VALUE_BITSIZE (arg); |
| 195 | VALUE_REGNO (val) = VALUE_REGNO (arg); |
| 196 | bcopy (VALUE_CONTENTS (arg), VALUE_CONTENTS (val), |
| 197 | TYPE_LENGTH (VALUE_TYPE (arg)) |
| 198 | * (VALUE_REPEATED (arg) ? VALUE_REPETITIONS (arg) : 1)); |
| 199 | return val; |
| 200 | } |
| 201 | \f |
| 202 | /* Access to the value history. */ |
| 203 | |
| 204 | /* Record a new value in the value history. |
| 205 | Returns the absolute history index of the entry. */ |
| 206 | |
| 207 | int |
| 208 | record_latest_value (val) |
| 209 | value val; |
| 210 | { |
| 211 | int i; |
| 212 | double foo; |
| 213 | |
| 214 | /* Check error now if about to store an invalid float. We return -1 |
| 215 | to the caller, but allow them to continue, e.g. to print it as "Nan". */ |
| 216 | if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FLT) { |
| 217 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &i); |
| 218 | if (i) return -1; /* Indicate value not saved in history */ |
| 219 | } |
| 220 | |
| 221 | /* Here we treat value_history_count as origin-zero |
| 222 | and applying to the value being stored now. */ |
| 223 | |
| 224 | i = value_history_count % VALUE_HISTORY_CHUNK; |
| 225 | if (i == 0) |
| 226 | { |
| 227 | register struct value_history_chunk *new |
| 228 | = (struct value_history_chunk *) |
| 229 | xmalloc (sizeof (struct value_history_chunk)); |
| 230 | bzero (new->values, sizeof new->values); |
| 231 | new->next = value_history_chain; |
| 232 | value_history_chain = new; |
| 233 | } |
| 234 | |
| 235 | value_history_chain->values[i] = val; |
| 236 | release_value (val); |
| 237 | |
| 238 | /* Now we regard value_history_count as origin-one |
| 239 | and applying to the value just stored. */ |
| 240 | |
| 241 | return ++value_history_count; |
| 242 | } |
| 243 | |
| 244 | /* Return a copy of the value in the history with sequence number NUM. */ |
| 245 | |
| 246 | value |
| 247 | access_value_history (num) |
| 248 | int num; |
| 249 | { |
| 250 | register struct value_history_chunk *chunk; |
| 251 | register int i; |
| 252 | register int absnum = num; |
| 253 | |
| 254 | if (absnum <= 0) |
| 255 | absnum += value_history_count; |
| 256 | |
| 257 | if (absnum <= 0) |
| 258 | { |
| 259 | if (num == 0) |
| 260 | error ("The history is empty."); |
| 261 | else if (num == 1) |
| 262 | error ("There is only one value in the history."); |
| 263 | else |
| 264 | error ("History does not go back to $$%d.", -num); |
| 265 | } |
| 266 | if (absnum > value_history_count) |
| 267 | error ("History has not yet reached $%d.", absnum); |
| 268 | |
| 269 | absnum--; |
| 270 | |
| 271 | /* Now absnum is always absolute and origin zero. */ |
| 272 | |
| 273 | chunk = value_history_chain; |
| 274 | for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK; |
| 275 | i > 0; i--) |
| 276 | chunk = chunk->next; |
| 277 | |
| 278 | return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]); |
| 279 | } |
| 280 | |
| 281 | /* Clear the value history entirely. |
| 282 | Must be done when new symbol tables are loaded, |
| 283 | because the type pointers become invalid. */ |
| 284 | |
| 285 | void |
| 286 | clear_value_history () |
| 287 | { |
| 288 | register struct value_history_chunk *next; |
| 289 | register int i; |
| 290 | register value val; |
| 291 | |
| 292 | while (value_history_chain) |
| 293 | { |
| 294 | for (i = 0; i < VALUE_HISTORY_CHUNK; i++) |
| 295 | if (val = value_history_chain->values[i]) |
| 296 | free (val); |
| 297 | next = value_history_chain->next; |
| 298 | free (value_history_chain); |
| 299 | value_history_chain = next; |
| 300 | } |
| 301 | value_history_count = 0; |
| 302 | } |
| 303 | |
| 304 | static void |
| 305 | value_history_info (num_exp, from_tty) |
| 306 | char *num_exp; |
| 307 | int from_tty; |
| 308 | { |
| 309 | register int i; |
| 310 | register value val; |
| 311 | static int num = 1; |
| 312 | |
| 313 | if (num_exp) |
| 314 | { |
| 315 | if (num_exp[0] == '+' && num_exp[1] == '\0') |
| 316 | /* "info history +" should print from the stored position. */ |
| 317 | ; |
| 318 | else |
| 319 | /* "info history <exp>" should print around value number <exp>. */ |
| 320 | num = parse_and_eval_address (num_exp) - 5; |
| 321 | } |
| 322 | else |
| 323 | { |
| 324 | /* "info history" means print the last 10 values. */ |
| 325 | num = value_history_count - 9; |
| 326 | } |
| 327 | |
| 328 | if (num <= 0) |
| 329 | num = 1; |
| 330 | |
| 331 | for (i = num; i < num + 10 && i <= value_history_count; i++) |
| 332 | { |
| 333 | val = access_value_history (i); |
| 334 | printf_filtered ("$%d = ", i); |
| 335 | value_print (val, stdout, 0, Val_pretty_default); |
| 336 | printf_filtered ("\n"); |
| 337 | } |
| 338 | |
| 339 | /* The next "info history +" should start after what we just printed. */ |
| 340 | num += 10; |
| 341 | |
| 342 | /* Hitting just return after this command should do the same thing as |
| 343 | "info history +". If num_exp is null, this is unnecessary, since |
| 344 | "info history +" is not useful after "info history". */ |
| 345 | if (from_tty && num_exp) |
| 346 | { |
| 347 | num_exp[0] = '+'; |
| 348 | num_exp[1] = '\0'; |
| 349 | } |
| 350 | } |
| 351 | \f |
| 352 | /* Internal variables. These are variables within the debugger |
| 353 | that hold values assigned by debugger commands. |
| 354 | The user refers to them with a '$' prefix |
| 355 | that does not appear in the variable names stored internally. */ |
| 356 | |
| 357 | static struct internalvar *internalvars; |
| 358 | |
| 359 | /* Look up an internal variable with name NAME. NAME should not |
| 360 | normally include a dollar sign. |
| 361 | |
| 362 | If the specified internal variable does not exist, |
| 363 | one is created, with a void value. */ |
| 364 | |
| 365 | struct internalvar * |
| 366 | lookup_internalvar (name) |
| 367 | char *name; |
| 368 | { |
| 369 | register struct internalvar *var; |
| 370 | |
| 371 | for (var = internalvars; var; var = var->next) |
| 372 | if (!strcmp (var->name, name)) |
| 373 | return var; |
| 374 | |
| 375 | var = (struct internalvar *) xmalloc (sizeof (struct internalvar)); |
| 376 | var->name = concat (name, "", ""); |
| 377 | var->value = allocate_value (builtin_type_void); |
| 378 | release_value (var->value); |
| 379 | var->next = internalvars; |
| 380 | internalvars = var; |
| 381 | return var; |
| 382 | } |
| 383 | |
| 384 | value |
| 385 | value_of_internalvar (var) |
| 386 | struct internalvar *var; |
| 387 | { |
| 388 | register value val; |
| 389 | |
| 390 | #ifdef IS_TRAPPED_INTERNALVAR |
| 391 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 392 | return VALUE_OF_TRAPPED_INTERNALVAR (var); |
| 393 | #endif |
| 394 | |
| 395 | val = value_copy (var->value); |
| 396 | VALUE_LVAL (val) = lval_internalvar; |
| 397 | VALUE_INTERNALVAR (val) = var; |
| 398 | return val; |
| 399 | } |
| 400 | |
| 401 | void |
| 402 | set_internalvar_component (var, offset, bitpos, bitsize, newval) |
| 403 | struct internalvar *var; |
| 404 | int offset, bitpos, bitsize; |
| 405 | value newval; |
| 406 | { |
| 407 | register char *addr = VALUE_CONTENTS (var->value) + offset; |
| 408 | |
| 409 | #ifdef IS_TRAPPED_INTERNALVAR |
| 410 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 411 | SET_TRAPPED_INTERNALVAR (var, newval, bitpos, bitsize, offset); |
| 412 | #endif |
| 413 | |
| 414 | if (bitsize) |
| 415 | modify_field (addr, (int) value_as_long (newval), |
| 416 | bitpos, bitsize); |
| 417 | else |
| 418 | bcopy (VALUE_CONTENTS (newval), addr, |
| 419 | TYPE_LENGTH (VALUE_TYPE (newval))); |
| 420 | } |
| 421 | |
| 422 | void |
| 423 | set_internalvar (var, val) |
| 424 | struct internalvar *var; |
| 425 | value val; |
| 426 | { |
| 427 | #ifdef IS_TRAPPED_INTERNALVAR |
| 428 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 429 | SET_TRAPPED_INTERNALVAR (var, val, 0, 0, 0); |
| 430 | #endif |
| 431 | |
| 432 | free (var->value); |
| 433 | var->value = value_copy (val); |
| 434 | release_value (var->value); |
| 435 | } |
| 436 | |
| 437 | char * |
| 438 | internalvar_name (var) |
| 439 | struct internalvar *var; |
| 440 | { |
| 441 | return var->name; |
| 442 | } |
| 443 | |
| 444 | /* Free all internalvars. Done when new symtabs are loaded, |
| 445 | because that makes the values invalid. */ |
| 446 | |
| 447 | void |
| 448 | clear_internalvars () |
| 449 | { |
| 450 | register struct internalvar *var; |
| 451 | |
| 452 | while (internalvars) |
| 453 | { |
| 454 | var = internalvars; |
| 455 | internalvars = var->next; |
| 456 | free (var->name); |
| 457 | free (var->value); |
| 458 | free (var); |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | static void |
| 463 | convenience_info () |
| 464 | { |
| 465 | register struct internalvar *var; |
| 466 | int varseen = 0; |
| 467 | |
| 468 | for (var = internalvars; var; var = var->next) |
| 469 | { |
| 470 | #ifdef IS_TRAPPED_INTERNALVAR |
| 471 | if (IS_TRAPPED_INTERNALVAR (var->name)) |
| 472 | continue; |
| 473 | #endif |
| 474 | if (!varseen) |
| 475 | { |
| 476 | printf ("Debugger convenience variables:\n\n"); |
| 477 | varseen = 1; |
| 478 | } |
| 479 | printf ("$%s: ", var->name); |
| 480 | value_print (var->value, stdout, 0, Val_pretty_default); |
| 481 | printf ("\n"); |
| 482 | } |
| 483 | if (!varseen) |
| 484 | printf ("No debugger convenience variables now defined.\n\ |
| 485 | Convenience variables have names starting with \"$\";\n\ |
| 486 | use \"set\" as in \"set $foo = 5\" to define them.\n"); |
| 487 | } |
| 488 | \f |
| 489 | /* Extract a value as a C number (either long or double). |
| 490 | Knows how to convert fixed values to double, or |
| 491 | floating values to long. |
| 492 | Does not deallocate the value. */ |
| 493 | |
| 494 | LONGEST |
| 495 | value_as_long (val) |
| 496 | register value val; |
| 497 | { |
| 498 | return unpack_long (VALUE_TYPE (val), VALUE_CONTENTS (val)); |
| 499 | } |
| 500 | |
| 501 | double |
| 502 | value_as_double (val) |
| 503 | register value val; |
| 504 | { |
| 505 | double foo; |
| 506 | int inv; |
| 507 | |
| 508 | foo = unpack_double (VALUE_TYPE (val), VALUE_CONTENTS (val), &inv); |
| 509 | if (inv) |
| 510 | error ("Invalid floating value found in program."); |
| 511 | return foo; |
| 512 | } |
| 513 | \f |
| 514 | /* Unpack raw data (copied from debugee) at VALADDR |
| 515 | as a long, or as a double, assuming the raw data is described |
| 516 | by type TYPE. Knows how to convert different sizes of values |
| 517 | and can convert between fixed and floating point. |
| 518 | |
| 519 | C++: It is assumed that the front-end has taken care of |
| 520 | all matters concerning pointers to members. A pointer |
| 521 | to member which reaches here is considered to be equivalent |
| 522 | to an INT (or some size). After all, it is only an offset. */ |
| 523 | |
| 524 | LONGEST |
| 525 | unpack_long (type, valaddr) |
| 526 | struct type *type; |
| 527 | char *valaddr; |
| 528 | { |
| 529 | register enum type_code code = TYPE_CODE (type); |
| 530 | register int len = TYPE_LENGTH (type); |
| 531 | register int nosign = TYPE_UNSIGNED (type); |
| 532 | |
| 533 | if (code == TYPE_CODE_ENUM) |
| 534 | code = TYPE_CODE_INT; |
| 535 | if (code == TYPE_CODE_FLT) |
| 536 | { |
| 537 | if (len == sizeof (float)) |
| 538 | return * (float *) valaddr; |
| 539 | |
| 540 | if (len == sizeof (double)) |
| 541 | return * (double *) valaddr; |
| 542 | } |
| 543 | else if (code == TYPE_CODE_INT && nosign) |
| 544 | { |
| 545 | if (len == sizeof (char)) |
| 546 | return * (unsigned char *) valaddr; |
| 547 | |
| 548 | if (len == sizeof (short)) |
| 549 | return * (unsigned short *) valaddr; |
| 550 | |
| 551 | if (len == sizeof (int)) |
| 552 | return * (unsigned int *) valaddr; |
| 553 | |
| 554 | if (len == sizeof (long)) |
| 555 | return * (unsigned long *) valaddr; |
| 556 | #ifdef LONG_LONG |
| 557 | if (len == sizeof (long long)) |
| 558 | return * (unsigned long long *) valaddr; |
| 559 | #endif |
| 560 | } |
| 561 | else if (code == TYPE_CODE_INT) |
| 562 | { |
| 563 | if (len == sizeof (char)) |
| 564 | return * (char *) valaddr; |
| 565 | |
| 566 | if (len == sizeof (short)) |
| 567 | return * (short *) valaddr; |
| 568 | |
| 569 | if (len == sizeof (int)) |
| 570 | return * (int *) valaddr; |
| 571 | |
| 572 | if (len == sizeof (long)) |
| 573 | return * (long *) valaddr; |
| 574 | |
| 575 | #ifdef LONG_LONG |
| 576 | if (len == sizeof (long long)) |
| 577 | return * (long long *) valaddr; |
| 578 | #endif |
| 579 | } |
| 580 | else if (code == TYPE_CODE_PTR |
| 581 | || code == TYPE_CODE_REF) |
| 582 | { |
| 583 | if (len == sizeof (char *)) |
| 584 | return (CORE_ADDR) * (char **) valaddr; |
| 585 | } |
| 586 | else if (code == TYPE_CODE_MEMBER) |
| 587 | error ("not implemented: member types in unpack_long"); |
| 588 | |
| 589 | error ("Value not integer or pointer."); |
| 590 | } |
| 591 | |
| 592 | /* Return a double value from the specified type and address. |
| 593 | INVP points to an int which is set to 0 for valid value, |
| 594 | 1 for invalid value (bad float format). In either case, |
| 595 | the returned double is OK to use. */ |
| 596 | |
| 597 | double |
| 598 | unpack_double (type, valaddr, invp) |
| 599 | struct type *type; |
| 600 | char *valaddr; |
| 601 | int *invp; |
| 602 | { |
| 603 | register enum type_code code = TYPE_CODE (type); |
| 604 | register int len = TYPE_LENGTH (type); |
| 605 | register int nosign = TYPE_UNSIGNED (type); |
| 606 | |
| 607 | *invp = 0; /* Assume valid. */ |
| 608 | if (code == TYPE_CODE_FLT) |
| 609 | { |
| 610 | if (INVALID_FLOAT (valaddr, len)) |
| 611 | { |
| 612 | *invp = 1; |
| 613 | return 1.234567891011121314; |
| 614 | } |
| 615 | |
| 616 | if (len == sizeof (float)) |
| 617 | return * (float *) valaddr; |
| 618 | |
| 619 | if (len == sizeof (double)) |
| 620 | { |
| 621 | /* Some machines require doubleword alignment for doubles. |
| 622 | This code works on them, and on other machines. */ |
| 623 | double temp; |
| 624 | bcopy ((char *) valaddr, (char *) &temp, sizeof (double)); |
| 625 | return temp; |
| 626 | } |
| 627 | } |
| 628 | else if (code == TYPE_CODE_INT && nosign) |
| 629 | { |
| 630 | if (len == sizeof (char)) |
| 631 | return * (unsigned char *) valaddr; |
| 632 | |
| 633 | if (len == sizeof (short)) |
| 634 | return * (unsigned short *) valaddr; |
| 635 | |
| 636 | if (len == sizeof (int)) |
| 637 | return * (unsigned int *) valaddr; |
| 638 | |
| 639 | if (len == sizeof (long)) |
| 640 | return * (unsigned long *) valaddr; |
| 641 | |
| 642 | #ifdef LONG_LONG |
| 643 | if (len == sizeof (long long)) |
| 644 | return * (unsigned long long *) valaddr; |
| 645 | #endif |
| 646 | } |
| 647 | else if (code == TYPE_CODE_INT) |
| 648 | { |
| 649 | if (len == sizeof (char)) |
| 650 | return * (char *) valaddr; |
| 651 | |
| 652 | if (len == sizeof (short)) |
| 653 | return * (short *) valaddr; |
| 654 | |
| 655 | if (len == sizeof (int)) |
| 656 | return * (int *) valaddr; |
| 657 | |
| 658 | if (len == sizeof (long)) |
| 659 | return * (long *) valaddr; |
| 660 | |
| 661 | #ifdef LONG_LONG |
| 662 | if (len == sizeof (long long)) |
| 663 | return * (long long *) valaddr; |
| 664 | #endif |
| 665 | } |
| 666 | |
| 667 | error ("Value not floating number."); |
| 668 | /* NOTREACHED */ |
| 669 | return (double) 0; /* To silence compiler warning. */ |
| 670 | } |
| 671 | \f |
| 672 | /* Given a value ARG1 of a struct or union type, |
| 673 | extract and return the value of one of its fields. |
| 674 | FIELDNO says which field. |
| 675 | |
| 676 | For C++, must also be able to return values from static fields */ |
| 677 | |
| 678 | value |
| 679 | value_field (arg1, fieldno) |
| 680 | register value arg1; |
| 681 | register int fieldno; |
| 682 | { |
| 683 | register value v; |
| 684 | register struct type *type = TYPE_FIELD_TYPE (VALUE_TYPE (arg1), fieldno); |
| 685 | register int offset; |
| 686 | |
| 687 | /* Handle packed fields */ |
| 688 | |
| 689 | offset = TYPE_FIELD_BITPOS (VALUE_TYPE (arg1), fieldno) / 8; |
| 690 | if (TYPE_FIELD_BITSIZE (VALUE_TYPE (arg1), fieldno)) |
| 691 | { |
| 692 | v = value_from_long (type, |
| 693 | unpack_field_as_long (VALUE_TYPE (arg1), |
| 694 | VALUE_CONTENTS (arg1), |
| 695 | fieldno)); |
| 696 | VALUE_BITPOS (v) = TYPE_FIELD_BITPOS (VALUE_TYPE (arg1), fieldno) % 8; |
| 697 | VALUE_BITSIZE (v) = TYPE_FIELD_BITSIZE (VALUE_TYPE (arg1), fieldno); |
| 698 | } |
| 699 | else |
| 700 | { |
| 701 | v = allocate_value (type); |
| 702 | bcopy (VALUE_CONTENTS (arg1) + offset, |
| 703 | VALUE_CONTENTS (v), |
| 704 | TYPE_LENGTH (type)); |
| 705 | } |
| 706 | VALUE_LVAL (v) = VALUE_LVAL (arg1); |
| 707 | if (VALUE_LVAL (arg1) == lval_internalvar) |
| 708 | VALUE_LVAL (v) = lval_internalvar_component; |
| 709 | VALUE_ADDRESS (v) = VALUE_ADDRESS (arg1); |
| 710 | VALUE_OFFSET (v) = offset + VALUE_OFFSET (arg1); |
| 711 | return v; |
| 712 | } |
| 713 | |
| 714 | value |
| 715 | value_fn_field (arg1, fieldno, subfieldno) |
| 716 | register value arg1; |
| 717 | register int fieldno; |
| 718 | { |
| 719 | register value v; |
| 720 | struct fn_field *f = TYPE_FN_FIELDLIST1 (VALUE_TYPE (arg1), fieldno); |
| 721 | register struct type *type = TYPE_FN_FIELD_TYPE (f, subfieldno); |
| 722 | struct symbol *sym; |
| 723 | |
| 724 | sym = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, subfieldno), |
| 725 | 0, VAR_NAMESPACE, 0); |
| 726 | if (! sym) error ("Internal error: could not find physical method named %s", |
| 727 | TYPE_FN_FIELD_PHYSNAME (f, subfieldno)); |
| 728 | |
| 729 | v = allocate_value (type); |
| 730 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); |
| 731 | VALUE_TYPE (v) = type; |
| 732 | return v; |
| 733 | } |
| 734 | |
| 735 | /* Return a virtual function as a value. |
| 736 | ARG1 is the object which provides the virtual function |
| 737 | table pointer. |
| 738 | F is the list of member functions which contains the desired virtual |
| 739 | function. |
| 740 | J is an index into F which provides the desired virtual function. |
| 741 | TYPE is the basetype which first provides the virtual function table. */ |
| 742 | value |
| 743 | value_virtual_fn_field (arg1, f, j, type) |
| 744 | value arg1; |
| 745 | struct fn_field *f; |
| 746 | int j; |
| 747 | struct type *type; |
| 748 | { |
| 749 | /* First, get the virtual function table pointer. That comes |
| 750 | with a strange type, so cast it to type `pointer to long' (which |
| 751 | should serve just fine as a function type). Then, index into |
| 752 | the table, and convert final value to appropriate function type. */ |
| 753 | value vfn, vtbl; |
| 754 | value vi = value_from_long (builtin_type_int, |
| 755 | (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j)); |
| 756 | VALUE_TYPE (arg1) = TYPE_VPTR_BASETYPE (type); |
| 757 | |
| 758 | /* This type may have been defined before its virtual function table |
| 759 | was. If so, fill in the virtual function table entry for the |
| 760 | type now. */ |
| 761 | if (TYPE_VPTR_FIELDNO (type) < 0) |
| 762 | TYPE_VPTR_FIELDNO (type) |
| 763 | = fill_in_vptr_fieldno (type); |
| 764 | |
| 765 | /* The virtual function table is now an array of structures |
| 766 | which have the form { int16 offset, delta; void *pfn; }. */ |
| 767 | vtbl = value_ind (value_field (arg1, TYPE_VPTR_FIELDNO (type))); |
| 768 | |
| 769 | /* Index into the virtual function table. This is hard-coded because |
| 770 | looking up a field is not cheap, and it may be important to save |
| 771 | time, e.g. if the user has set a conditional breakpoint calling |
| 772 | a virtual function. */ |
| 773 | vfn = value_field (value_subscript (vtbl, vi), 2); |
| 774 | |
| 775 | /* Reinstantiate the function pointer with the correct type. */ |
| 776 | VALUE_TYPE (vfn) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)); |
| 777 | return vfn; |
| 778 | } |
| 779 | |
| 780 | /* The value of a static class member does not depend |
| 781 | on its instance, only on its type. If FIELDNO >= 0, |
| 782 | then fieldno is a valid field number and is used directly. |
| 783 | Otherwise, FIELDNAME is the name of the field we are |
| 784 | searching for. If it is not a static field name, an |
| 785 | error is signaled. TYPE is the type in which we look for the |
| 786 | static field member. */ |
| 787 | value |
| 788 | value_static_field (type, fieldname, fieldno) |
| 789 | register struct type *type; |
| 790 | char *fieldname; |
| 791 | register int fieldno; |
| 792 | { |
| 793 | register value v; |
| 794 | struct symbol *sym; |
| 795 | |
| 796 | if (fieldno < 0) |
| 797 | { |
| 798 | register struct type *t = type; |
| 799 | /* Look for static field. */ |
| 800 | while (t) |
| 801 | { |
| 802 | int i; |
| 803 | for (i = TYPE_NFIELDS (t) - 1; i >= 0; i--) |
| 804 | if (! strcmp (TYPE_FIELD_NAME (t, i), fieldname)) |
| 805 | { |
| 806 | if (TYPE_FIELD_STATIC (t, i)) |
| 807 | { |
| 808 | fieldno = i; |
| 809 | goto found; |
| 810 | } |
| 811 | else |
| 812 | error ("field `%s' is not static"); |
| 813 | } |
| 814 | t = TYPE_BASECLASSES (t) ? TYPE_BASECLASS (t, 1) : 0; |
| 815 | } |
| 816 | |
| 817 | t = type; |
| 818 | |
| 819 | if (destructor_name_p (fieldname, t)) |
| 820 | error ("use `info method' command to print out value of destructor"); |
| 821 | |
| 822 | while (t) |
| 823 | { |
| 824 | int i, j; |
| 825 | |
| 826 | for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; i--) |
| 827 | { |
| 828 | if (! strcmp (TYPE_FN_FIELDLIST_NAME (t, i), fieldname)) |
| 829 | { |
| 830 | error ("use `info method' command to print value of method \"%s\"", fieldname); |
| 831 | } |
| 832 | } |
| 833 | t = TYPE_BASECLASSES (t) ? TYPE_BASECLASS (t, 1) : 0; |
| 834 | } |
| 835 | error("there is no field named %s", fieldname); |
| 836 | } |
| 837 | |
| 838 | found: |
| 839 | |
| 840 | sym = lookup_symbol (TYPE_FIELD_STATIC_PHYSNAME (type, fieldno), |
| 841 | 0, VAR_NAMESPACE, 0); |
| 842 | if (! sym) error ("Internal error: could not find physical static variable named %s", TYPE_FIELD_BITSIZE (type, fieldno)); |
| 843 | |
| 844 | type = TYPE_FIELD_TYPE (type, fieldno); |
| 845 | v = value_at (type, (CORE_ADDR)SYMBOL_BLOCK_VALUE (sym)); |
| 846 | return v; |
| 847 | } |
| 848 | |
| 849 | long |
| 850 | unpack_field_as_long (type, valaddr, fieldno) |
| 851 | struct type *type; |
| 852 | char *valaddr; |
| 853 | int fieldno; |
| 854 | { |
| 855 | long val; |
| 856 | int bitpos = TYPE_FIELD_BITPOS (type, fieldno); |
| 857 | int bitsize = TYPE_FIELD_BITSIZE (type, fieldno); |
| 858 | |
| 859 | bcopy (valaddr + bitpos / 8, &val, sizeof val); |
| 860 | |
| 861 | /* Extracting bits depends on endianness of the machine. */ |
| 862 | #ifdef BITS_BIG_ENDIAN |
| 863 | val = val >> (sizeof val * 8 - bitpos % 8 - bitsize); |
| 864 | #else |
| 865 | val = val >> (bitpos % 8); |
| 866 | #endif |
| 867 | |
| 868 | val &= (1 << bitsize) - 1; |
| 869 | return val; |
| 870 | } |
| 871 | |
| 872 | void |
| 873 | modify_field (addr, fieldval, bitpos, bitsize) |
| 874 | char *addr; |
| 875 | int fieldval; |
| 876 | int bitpos, bitsize; |
| 877 | { |
| 878 | long oword; |
| 879 | |
| 880 | /* Reject values too big to fit in the field in question. |
| 881 | Otherwise adjoining fields may be corrupted. */ |
| 882 | if (fieldval & ~((1<<bitsize)-1)) |
| 883 | error ("Value %d does not fit in %d bits.", fieldval, bitsize); |
| 884 | |
| 885 | bcopy (addr, &oword, sizeof oword); |
| 886 | |
| 887 | /* Shifting for bit field depends on endianness of the machine. */ |
| 888 | #ifdef BITS_BIG_ENDIAN |
| 889 | bitpos = sizeof (oword) * 8 - bitpos - bitsize; |
| 890 | #endif |
| 891 | |
| 892 | oword &= ~(((1 << bitsize) - 1) << bitpos); |
| 893 | oword |= fieldval << bitpos; |
| 894 | bcopy (&oword, addr, sizeof oword); |
| 895 | } |
| 896 | \f |
| 897 | /* Convert C numbers into newly allocated values */ |
| 898 | |
| 899 | value |
| 900 | value_from_long (type, num) |
| 901 | struct type *type; |
| 902 | register LONGEST num; |
| 903 | { |
| 904 | register value val = allocate_value (type); |
| 905 | register enum type_code code = TYPE_CODE (type); |
| 906 | register int len = TYPE_LENGTH (type); |
| 907 | |
| 908 | if (code == TYPE_CODE_INT || code == TYPE_CODE_ENUM) |
| 909 | { |
| 910 | if (len == sizeof (char)) |
| 911 | * (char *) VALUE_CONTENTS (val) = num; |
| 912 | else if (len == sizeof (short)) |
| 913 | * (short *) VALUE_CONTENTS (val) = num; |
| 914 | else if (len == sizeof (int)) |
| 915 | * (int *) VALUE_CONTENTS (val) = num; |
| 916 | else if (len == sizeof (long)) |
| 917 | * (long *) VALUE_CONTENTS (val) = num; |
| 918 | #ifdef LONG_LONG |
| 919 | else if (len == sizeof (long long)) |
| 920 | * (long long *) VALUE_CONTENTS (val) = num; |
| 921 | #endif |
| 922 | else |
| 923 | error ("Integer type encountered with unexpected data length."); |
| 924 | } |
| 925 | else |
| 926 | error ("Unexpected type encountered for integer constant."); |
| 927 | |
| 928 | return val; |
| 929 | } |
| 930 | |
| 931 | value |
| 932 | value_from_double (type, num) |
| 933 | struct type *type; |
| 934 | double num; |
| 935 | { |
| 936 | register value val = allocate_value (type); |
| 937 | register enum type_code code = TYPE_CODE (type); |
| 938 | register int len = TYPE_LENGTH (type); |
| 939 | |
| 940 | if (code == TYPE_CODE_FLT) |
| 941 | { |
| 942 | if (len == sizeof (float)) |
| 943 | * (float *) VALUE_CONTENTS (val) = num; |
| 944 | else if (len == sizeof (double)) |
| 945 | * (double *) VALUE_CONTENTS (val) = num; |
| 946 | else |
| 947 | error ("Floating type encountered with unexpected data length."); |
| 948 | } |
| 949 | else |
| 950 | error ("Unexpected type encountered for floating constant."); |
| 951 | |
| 952 | return val; |
| 953 | } |
| 954 | \f |
| 955 | /* Deal with the value that is "about to be returned". */ |
| 956 | |
| 957 | /* Return the value that a function returning now |
| 958 | would be returning to its caller, assuming its type is VALTYPE. |
| 959 | RETBUF is where we look for what ought to be the contents |
| 960 | of the registers (in raw form). This is because it is often |
| 961 | desirable to restore old values to those registers |
| 962 | after saving the contents of interest, and then call |
| 963 | this function using the saved values. |
| 964 | struct_return is non-zero when the function in question is |
| 965 | using the structure return conventions on the machine in question; |
| 966 | 0 when it is using the value returning conventions (this often |
| 967 | means returning pointer to where structure is vs. returning value). */ |
| 968 | |
| 969 | value |
| 970 | value_being_returned (valtype, retbuf, struct_return) |
| 971 | register struct type *valtype; |
| 972 | char retbuf[REGISTER_BYTES]; |
| 973 | int struct_return; |
| 974 | { |
| 975 | register value val; |
| 976 | |
| 977 | if (struct_return) |
| 978 | return value_at (valtype, EXTRACT_STRUCT_VALUE_ADDRESS (retbuf)); |
| 979 | |
| 980 | val = allocate_value (valtype); |
| 981 | EXTRACT_RETURN_VALUE (valtype, retbuf, VALUE_CONTENTS (val)); |
| 982 | |
| 983 | return val; |
| 984 | } |
| 985 | |
| 986 | /* Return true if the function specified is using the structure returning |
| 987 | convention on this machine to return arguments, or 0 if it is using |
| 988 | the value returning convention. FUNCTION is the value representing |
| 989 | the function, FUNCADDR is the address of the function, and VALUE_TYPE |
| 990 | is the type returned by the function */ |
| 991 | |
| 992 | struct block *block_for_pc (); |
| 993 | |
| 994 | int |
| 995 | using_struct_return (function, funcaddr, value_type) |
| 996 | value function; |
| 997 | CORE_ADDR funcaddr; |
| 998 | struct type *value_type; |
| 999 | { |
| 1000 | register enum type_code code = TYPE_CODE (value_type); |
| 1001 | |
| 1002 | if (code == TYPE_CODE_STRUCT || |
| 1003 | code == TYPE_CODE_UNION || |
| 1004 | code == TYPE_CODE_ARRAY) |
| 1005 | { |
| 1006 | struct block *b = block_for_pc (funcaddr); |
| 1007 | |
| 1008 | if (!(BLOCK_GCC_COMPILED (b) && TYPE_LENGTH (value_type) < 8)) |
| 1009 | return 1; |
| 1010 | } |
| 1011 | |
| 1012 | return 0; |
| 1013 | } |
| 1014 | |
| 1015 | /* Store VAL so it will be returned if a function returns now. |
| 1016 | Does not verify that VAL's type matches what the current |
| 1017 | function wants to return. */ |
| 1018 | |
| 1019 | void |
| 1020 | set_return_value (val) |
| 1021 | value val; |
| 1022 | { |
| 1023 | register enum type_code code = TYPE_CODE (VALUE_TYPE (val)); |
| 1024 | char regbuf[REGISTER_BYTES]; |
| 1025 | double dbuf; |
| 1026 | LONGEST lbuf; |
| 1027 | |
| 1028 | if (code == TYPE_CODE_STRUCT |
| 1029 | || code == TYPE_CODE_UNION) |
| 1030 | error ("Specifying a struct or union return value is not supported."); |
| 1031 | |
| 1032 | if (code == TYPE_CODE_FLT) |
| 1033 | { |
| 1034 | dbuf = value_as_double (val); |
| 1035 | |
| 1036 | STORE_RETURN_VALUE (VALUE_TYPE (val), &dbuf); |
| 1037 | } |
| 1038 | else |
| 1039 | { |
| 1040 | lbuf = value_as_long (val); |
| 1041 | STORE_RETURN_VALUE (VALUE_TYPE (val), &lbuf); |
| 1042 | } |
| 1043 | } |
| 1044 | \f |
| 1045 | void |
| 1046 | _initialize_values () |
| 1047 | { |
| 1048 | add_info ("convenience", convenience_info, |
| 1049 | "Debugger convenience (\"$foo\") variables.\n\ |
| 1050 | These variables are created when you assign them values;\n\ |
| 1051 | thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\ |
| 1052 | A few convenience variables are given values automatically GDB:\n\ |
| 1053 | \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\ |
| 1054 | \"$__\" holds the contents of the last address examined with \"x\"."); |
| 1055 | |
| 1056 | add_info ("values", value_history_info, |
| 1057 | "Elements of value history (around item number IDX, or last ten)."); |
| 1058 | add_info_alias ("history", value_history_info, 0); |
| 1059 | } |