| 1 | /* Find a variable's value in memory, for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
| 3 | 1996, 1997, 1998, 1999, 2000, 2001 |
| 4 | Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "symtab.h" |
| 25 | #include "gdbtypes.h" |
| 26 | #include "frame.h" |
| 27 | #include "value.h" |
| 28 | #include "gdbcore.h" |
| 29 | #include "inferior.h" |
| 30 | #include "target.h" |
| 31 | #include "gdb_string.h" |
| 32 | #include "gdb_assert.h" |
| 33 | #include "floatformat.h" |
| 34 | #include "symfile.h" /* for overlay functions */ |
| 35 | #include "regcache.h" |
| 36 | |
| 37 | /* Basic byte-swapping routines. GDB has needed these for a long time... |
| 38 | All extract a target-format integer at ADDR which is LEN bytes long. */ |
| 39 | |
| 40 | #if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8 |
| 41 | /* 8 bit characters are a pretty safe assumption these days, so we |
| 42 | assume it throughout all these swapping routines. If we had to deal with |
| 43 | 9 bit characters, we would need to make len be in bits and would have |
| 44 | to re-write these routines... */ |
| 45 | you lose |
| 46 | #endif |
| 47 | |
| 48 | LONGEST |
| 49 | extract_signed_integer (void *addr, int len) |
| 50 | { |
| 51 | LONGEST retval; |
| 52 | unsigned char *p; |
| 53 | unsigned char *startaddr = (unsigned char *) addr; |
| 54 | unsigned char *endaddr = startaddr + len; |
| 55 | |
| 56 | if (len > (int) sizeof (LONGEST)) |
| 57 | error ("\ |
| 58 | That operation is not available on integers of more than %d bytes.", |
| 59 | sizeof (LONGEST)); |
| 60 | |
| 61 | /* Start at the most significant end of the integer, and work towards |
| 62 | the least significant. */ |
| 63 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| 64 | { |
| 65 | p = startaddr; |
| 66 | /* Do the sign extension once at the start. */ |
| 67 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
| 68 | for (++p; p < endaddr; ++p) |
| 69 | retval = (retval << 8) | *p; |
| 70 | } |
| 71 | else |
| 72 | { |
| 73 | p = endaddr - 1; |
| 74 | /* Do the sign extension once at the start. */ |
| 75 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
| 76 | for (--p; p >= startaddr; --p) |
| 77 | retval = (retval << 8) | *p; |
| 78 | } |
| 79 | return retval; |
| 80 | } |
| 81 | |
| 82 | ULONGEST |
| 83 | extract_unsigned_integer (void *addr, int len) |
| 84 | { |
| 85 | ULONGEST retval; |
| 86 | unsigned char *p; |
| 87 | unsigned char *startaddr = (unsigned char *) addr; |
| 88 | unsigned char *endaddr = startaddr + len; |
| 89 | |
| 90 | if (len > (int) sizeof (ULONGEST)) |
| 91 | error ("\ |
| 92 | That operation is not available on integers of more than %d bytes.", |
| 93 | sizeof (ULONGEST)); |
| 94 | |
| 95 | /* Start at the most significant end of the integer, and work towards |
| 96 | the least significant. */ |
| 97 | retval = 0; |
| 98 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| 99 | { |
| 100 | for (p = startaddr; p < endaddr; ++p) |
| 101 | retval = (retval << 8) | *p; |
| 102 | } |
| 103 | else |
| 104 | { |
| 105 | for (p = endaddr - 1; p >= startaddr; --p) |
| 106 | retval = (retval << 8) | *p; |
| 107 | } |
| 108 | return retval; |
| 109 | } |
| 110 | |
| 111 | /* Sometimes a long long unsigned integer can be extracted as a |
| 112 | LONGEST value. This is done so that we can print these values |
| 113 | better. If this integer can be converted to a LONGEST, this |
| 114 | function returns 1 and sets *PVAL. Otherwise it returns 0. */ |
| 115 | |
| 116 | int |
| 117 | extract_long_unsigned_integer (void *addr, int orig_len, LONGEST *pval) |
| 118 | { |
| 119 | char *p, *first_addr; |
| 120 | int len; |
| 121 | |
| 122 | len = orig_len; |
| 123 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| 124 | { |
| 125 | for (p = (char *) addr; |
| 126 | len > (int) sizeof (LONGEST) && p < (char *) addr + orig_len; |
| 127 | p++) |
| 128 | { |
| 129 | if (*p == 0) |
| 130 | len--; |
| 131 | else |
| 132 | break; |
| 133 | } |
| 134 | first_addr = p; |
| 135 | } |
| 136 | else |
| 137 | { |
| 138 | first_addr = (char *) addr; |
| 139 | for (p = (char *) addr + orig_len - 1; |
| 140 | len > (int) sizeof (LONGEST) && p >= (char *) addr; |
| 141 | p--) |
| 142 | { |
| 143 | if (*p == 0) |
| 144 | len--; |
| 145 | else |
| 146 | break; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | if (len <= (int) sizeof (LONGEST)) |
| 151 | { |
| 152 | *pval = (LONGEST) extract_unsigned_integer (first_addr, |
| 153 | sizeof (LONGEST)); |
| 154 | return 1; |
| 155 | } |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | /* Treat the LEN bytes at ADDR as a target-format address, and return |
| 162 | that address. ADDR is a buffer in the GDB process, not in the |
| 163 | inferior. |
| 164 | |
| 165 | This function should only be used by target-specific code. It |
| 166 | assumes that a pointer has the same representation as that thing's |
| 167 | address represented as an integer. Some machines use word |
| 168 | addresses, or similarly munged things, for certain types of |
| 169 | pointers, so that assumption doesn't hold everywhere. |
| 170 | |
| 171 | Common code should use extract_typed_address instead, or something |
| 172 | else based on POINTER_TO_ADDRESS. */ |
| 173 | |
| 174 | CORE_ADDR |
| 175 | extract_address (void *addr, int len) |
| 176 | { |
| 177 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 178 | whether we want this to be true eventually. */ |
| 179 | return (CORE_ADDR) extract_unsigned_integer (addr, len); |
| 180 | } |
| 181 | |
| 182 | |
| 183 | /* Treat the bytes at BUF as a pointer of type TYPE, and return the |
| 184 | address it represents. */ |
| 185 | CORE_ADDR |
| 186 | extract_typed_address (void *buf, struct type *type) |
| 187 | { |
| 188 | if (TYPE_CODE (type) != TYPE_CODE_PTR |
| 189 | && TYPE_CODE (type) != TYPE_CODE_REF) |
| 190 | internal_error (__FILE__, __LINE__, |
| 191 | "extract_typed_address: " |
| 192 | "type is not a pointer or reference"); |
| 193 | |
| 194 | return POINTER_TO_ADDRESS (type, buf); |
| 195 | } |
| 196 | |
| 197 | |
| 198 | void |
| 199 | store_signed_integer (void *addr, int len, LONGEST val) |
| 200 | { |
| 201 | unsigned char *p; |
| 202 | unsigned char *startaddr = (unsigned char *) addr; |
| 203 | unsigned char *endaddr = startaddr + len; |
| 204 | |
| 205 | /* Start at the least significant end of the integer, and work towards |
| 206 | the most significant. */ |
| 207 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| 208 | { |
| 209 | for (p = endaddr - 1; p >= startaddr; --p) |
| 210 | { |
| 211 | *p = val & 0xff; |
| 212 | val >>= 8; |
| 213 | } |
| 214 | } |
| 215 | else |
| 216 | { |
| 217 | for (p = startaddr; p < endaddr; ++p) |
| 218 | { |
| 219 | *p = val & 0xff; |
| 220 | val >>= 8; |
| 221 | } |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | void |
| 226 | store_unsigned_integer (void *addr, int len, ULONGEST val) |
| 227 | { |
| 228 | unsigned char *p; |
| 229 | unsigned char *startaddr = (unsigned char *) addr; |
| 230 | unsigned char *endaddr = startaddr + len; |
| 231 | |
| 232 | /* Start at the least significant end of the integer, and work towards |
| 233 | the most significant. */ |
| 234 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| 235 | { |
| 236 | for (p = endaddr - 1; p >= startaddr; --p) |
| 237 | { |
| 238 | *p = val & 0xff; |
| 239 | val >>= 8; |
| 240 | } |
| 241 | } |
| 242 | else |
| 243 | { |
| 244 | for (p = startaddr; p < endaddr; ++p) |
| 245 | { |
| 246 | *p = val & 0xff; |
| 247 | val >>= 8; |
| 248 | } |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | /* Store the address VAL as a LEN-byte value in target byte order at |
| 253 | ADDR. ADDR is a buffer in the GDB process, not in the inferior. |
| 254 | |
| 255 | This function should only be used by target-specific code. It |
| 256 | assumes that a pointer has the same representation as that thing's |
| 257 | address represented as an integer. Some machines use word |
| 258 | addresses, or similarly munged things, for certain types of |
| 259 | pointers, so that assumption doesn't hold everywhere. |
| 260 | |
| 261 | Common code should use store_typed_address instead, or something else |
| 262 | based on ADDRESS_TO_POINTER. */ |
| 263 | void |
| 264 | store_address (void *addr, int len, LONGEST val) |
| 265 | { |
| 266 | store_unsigned_integer (addr, len, val); |
| 267 | } |
| 268 | |
| 269 | |
| 270 | /* Store the address ADDR as a pointer of type TYPE at BUF, in target |
| 271 | form. */ |
| 272 | void |
| 273 | store_typed_address (void *buf, struct type *type, CORE_ADDR addr) |
| 274 | { |
| 275 | if (TYPE_CODE (type) != TYPE_CODE_PTR |
| 276 | && TYPE_CODE (type) != TYPE_CODE_REF) |
| 277 | internal_error (__FILE__, __LINE__, |
| 278 | "store_typed_address: " |
| 279 | "type is not a pointer or reference"); |
| 280 | |
| 281 | ADDRESS_TO_POINTER (type, buf, addr); |
| 282 | } |
| 283 | |
| 284 | |
| 285 | |
| 286 | /* Return a `value' with the contents of (virtual or cooked) register |
| 287 | REGNUM as found in the specified FRAME. The register's type is |
| 288 | determined by REGISTER_VIRTUAL_TYPE. |
| 289 | |
| 290 | NOTE: returns NULL if register value is not available. Caller will |
| 291 | check return value or die! */ |
| 292 | |
| 293 | struct value * |
| 294 | value_of_register (int regnum, struct frame_info *frame) |
| 295 | { |
| 296 | CORE_ADDR addr; |
| 297 | int optim; |
| 298 | struct value *reg_val; |
| 299 | char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE); |
| 300 | enum lval_type lval; |
| 301 | |
| 302 | get_saved_register (raw_buffer, &optim, &addr, |
| 303 | frame, regnum, &lval); |
| 304 | |
| 305 | if (register_cached (regnum) < 0) |
| 306 | return NULL; /* register value not available */ |
| 307 | |
| 308 | reg_val = allocate_value (REGISTER_VIRTUAL_TYPE (regnum)); |
| 309 | |
| 310 | /* Convert raw data to virtual format if necessary. */ |
| 311 | |
| 312 | if (REGISTER_CONVERTIBLE (regnum)) |
| 313 | { |
| 314 | REGISTER_CONVERT_TO_VIRTUAL (regnum, REGISTER_VIRTUAL_TYPE (regnum), |
| 315 | raw_buffer, VALUE_CONTENTS_RAW (reg_val)); |
| 316 | } |
| 317 | else if (REGISTER_RAW_SIZE (regnum) == REGISTER_VIRTUAL_SIZE (regnum)) |
| 318 | memcpy (VALUE_CONTENTS_RAW (reg_val), raw_buffer, |
| 319 | REGISTER_RAW_SIZE (regnum)); |
| 320 | else |
| 321 | internal_error (__FILE__, __LINE__, |
| 322 | "Register \"%s\" (%d) has conflicting raw (%d) and virtual (%d) size", |
| 323 | REGISTER_NAME (regnum), |
| 324 | regnum, |
| 325 | REGISTER_RAW_SIZE (regnum), |
| 326 | REGISTER_VIRTUAL_SIZE (regnum)); |
| 327 | VALUE_LVAL (reg_val) = lval; |
| 328 | VALUE_ADDRESS (reg_val) = addr; |
| 329 | VALUE_REGNO (reg_val) = regnum; |
| 330 | VALUE_OPTIMIZED_OUT (reg_val) = optim; |
| 331 | return reg_val; |
| 332 | } |
| 333 | |
| 334 | /* Given a pointer of type TYPE in target form in BUF, return the |
| 335 | address it represents. */ |
| 336 | CORE_ADDR |
| 337 | unsigned_pointer_to_address (struct type *type, void *buf) |
| 338 | { |
| 339 | return extract_address (buf, TYPE_LENGTH (type)); |
| 340 | } |
| 341 | |
| 342 | CORE_ADDR |
| 343 | signed_pointer_to_address (struct type *type, void *buf) |
| 344 | { |
| 345 | return extract_signed_integer (buf, TYPE_LENGTH (type)); |
| 346 | } |
| 347 | |
| 348 | /* Given an address, store it as a pointer of type TYPE in target |
| 349 | format in BUF. */ |
| 350 | void |
| 351 | unsigned_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr) |
| 352 | { |
| 353 | store_address (buf, TYPE_LENGTH (type), addr); |
| 354 | } |
| 355 | |
| 356 | void |
| 357 | address_to_signed_pointer (struct type *type, void *buf, CORE_ADDR addr) |
| 358 | { |
| 359 | store_signed_integer (buf, TYPE_LENGTH (type), addr); |
| 360 | } |
| 361 | \f |
| 362 | /* Will calling read_var_value or locate_var_value on SYM end |
| 363 | up caring what frame it is being evaluated relative to? SYM must |
| 364 | be non-NULL. */ |
| 365 | int |
| 366 | symbol_read_needs_frame (struct symbol *sym) |
| 367 | { |
| 368 | switch (SYMBOL_CLASS (sym)) |
| 369 | { |
| 370 | /* All cases listed explicitly so that gcc -Wall will detect it if |
| 371 | we failed to consider one. */ |
| 372 | case LOC_REGISTER: |
| 373 | case LOC_ARG: |
| 374 | case LOC_REF_ARG: |
| 375 | case LOC_REGPARM: |
| 376 | case LOC_REGPARM_ADDR: |
| 377 | case LOC_LOCAL: |
| 378 | case LOC_LOCAL_ARG: |
| 379 | case LOC_BASEREG: |
| 380 | case LOC_BASEREG_ARG: |
| 381 | case LOC_THREAD_LOCAL_STATIC: |
| 382 | return 1; |
| 383 | |
| 384 | case LOC_UNDEF: |
| 385 | case LOC_CONST: |
| 386 | case LOC_STATIC: |
| 387 | case LOC_INDIRECT: |
| 388 | case LOC_TYPEDEF: |
| 389 | |
| 390 | case LOC_LABEL: |
| 391 | /* Getting the address of a label can be done independently of the block, |
| 392 | even if some *uses* of that address wouldn't work so well without |
| 393 | the right frame. */ |
| 394 | |
| 395 | case LOC_BLOCK: |
| 396 | case LOC_CONST_BYTES: |
| 397 | case LOC_UNRESOLVED: |
| 398 | case LOC_OPTIMIZED_OUT: |
| 399 | return 0; |
| 400 | } |
| 401 | return 1; |
| 402 | } |
| 403 | |
| 404 | /* Given a struct symbol for a variable, |
| 405 | and a stack frame id, read the value of the variable |
| 406 | and return a (pointer to a) struct value containing the value. |
| 407 | If the variable cannot be found, return a zero pointer. |
| 408 | If FRAME is NULL, use the selected_frame. */ |
| 409 | |
| 410 | struct value * |
| 411 | read_var_value (register struct symbol *var, struct frame_info *frame) |
| 412 | { |
| 413 | register struct value *v; |
| 414 | struct type *type = SYMBOL_TYPE (var); |
| 415 | CORE_ADDR addr; |
| 416 | register int len; |
| 417 | |
| 418 | v = allocate_value (type); |
| 419 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ |
| 420 | VALUE_BFD_SECTION (v) = SYMBOL_BFD_SECTION (var); |
| 421 | |
| 422 | len = TYPE_LENGTH (type); |
| 423 | |
| 424 | if (frame == NULL) |
| 425 | frame = selected_frame; |
| 426 | |
| 427 | switch (SYMBOL_CLASS (var)) |
| 428 | { |
| 429 | case LOC_CONST: |
| 430 | /* Put the constant back in target format. */ |
| 431 | store_signed_integer (VALUE_CONTENTS_RAW (v), len, |
| 432 | (LONGEST) SYMBOL_VALUE (var)); |
| 433 | VALUE_LVAL (v) = not_lval; |
| 434 | return v; |
| 435 | |
| 436 | case LOC_LABEL: |
| 437 | /* Put the constant back in target format. */ |
| 438 | if (overlay_debugging) |
| 439 | { |
| 440 | CORE_ADDR addr |
| 441 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), |
| 442 | SYMBOL_BFD_SECTION (var)); |
| 443 | store_typed_address (VALUE_CONTENTS_RAW (v), type, addr); |
| 444 | } |
| 445 | else |
| 446 | store_typed_address (VALUE_CONTENTS_RAW (v), type, |
| 447 | SYMBOL_VALUE_ADDRESS (var)); |
| 448 | VALUE_LVAL (v) = not_lval; |
| 449 | return v; |
| 450 | |
| 451 | case LOC_CONST_BYTES: |
| 452 | { |
| 453 | char *bytes_addr; |
| 454 | bytes_addr = SYMBOL_VALUE_BYTES (var); |
| 455 | memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len); |
| 456 | VALUE_LVAL (v) = not_lval; |
| 457 | return v; |
| 458 | } |
| 459 | |
| 460 | case LOC_STATIC: |
| 461 | if (overlay_debugging) |
| 462 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), |
| 463 | SYMBOL_BFD_SECTION (var)); |
| 464 | else |
| 465 | addr = SYMBOL_VALUE_ADDRESS (var); |
| 466 | break; |
| 467 | |
| 468 | case LOC_INDIRECT: |
| 469 | { |
| 470 | /* The import slot does not have a real address in it from the |
| 471 | dynamic loader (dld.sl on HP-UX), if the target hasn't |
| 472 | begun execution yet, so check for that. */ |
| 473 | CORE_ADDR locaddr; |
| 474 | struct value *loc; |
| 475 | if (!target_has_execution) |
| 476 | error ("\ |
| 477 | Attempt to access variable defined in different shared object or load module when\n\ |
| 478 | addresses have not been bound by the dynamic loader. Try again when executable is running."); |
| 479 | |
| 480 | locaddr = SYMBOL_VALUE_ADDRESS (var); |
| 481 | loc = value_at (lookup_pointer_type (type), locaddr, NULL); |
| 482 | addr = value_as_address (loc); |
| 483 | } |
| 484 | |
| 485 | case LOC_ARG: |
| 486 | if (frame == NULL) |
| 487 | return 0; |
| 488 | addr = FRAME_ARGS_ADDRESS (frame); |
| 489 | if (!addr) |
| 490 | return 0; |
| 491 | addr += SYMBOL_VALUE (var); |
| 492 | break; |
| 493 | |
| 494 | case LOC_REF_ARG: |
| 495 | { |
| 496 | struct value *ref; |
| 497 | CORE_ADDR argref; |
| 498 | if (frame == NULL) |
| 499 | return 0; |
| 500 | argref = FRAME_ARGS_ADDRESS (frame); |
| 501 | if (!argref) |
| 502 | return 0; |
| 503 | argref += SYMBOL_VALUE (var); |
| 504 | ref = value_at (lookup_pointer_type (type), argref, NULL); |
| 505 | addr = value_as_address (ref); |
| 506 | break; |
| 507 | } |
| 508 | |
| 509 | case LOC_LOCAL: |
| 510 | case LOC_LOCAL_ARG: |
| 511 | if (frame == NULL) |
| 512 | return 0; |
| 513 | addr = FRAME_LOCALS_ADDRESS (frame); |
| 514 | addr += SYMBOL_VALUE (var); |
| 515 | break; |
| 516 | |
| 517 | case LOC_BASEREG: |
| 518 | case LOC_BASEREG_ARG: |
| 519 | case LOC_THREAD_LOCAL_STATIC: |
| 520 | { |
| 521 | struct value *regval; |
| 522 | |
| 523 | regval = value_from_register (lookup_pointer_type (type), |
| 524 | SYMBOL_BASEREG (var), frame); |
| 525 | if (regval == NULL) |
| 526 | error ("Value of base register not available."); |
| 527 | addr = value_as_address (regval); |
| 528 | addr += SYMBOL_VALUE (var); |
| 529 | break; |
| 530 | } |
| 531 | |
| 532 | case LOC_TYPEDEF: |
| 533 | error ("Cannot look up value of a typedef"); |
| 534 | break; |
| 535 | |
| 536 | case LOC_BLOCK: |
| 537 | if (overlay_debugging) |
| 538 | VALUE_ADDRESS (v) = symbol_overlayed_address |
| 539 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var)); |
| 540 | else |
| 541 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); |
| 542 | return v; |
| 543 | |
| 544 | case LOC_REGISTER: |
| 545 | case LOC_REGPARM: |
| 546 | case LOC_REGPARM_ADDR: |
| 547 | { |
| 548 | struct block *b; |
| 549 | int regno = SYMBOL_VALUE (var); |
| 550 | struct value *regval; |
| 551 | |
| 552 | if (frame == NULL) |
| 553 | return 0; |
| 554 | b = get_frame_block (frame); |
| 555 | |
| 556 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) |
| 557 | { |
| 558 | regval = value_from_register (lookup_pointer_type (type), |
| 559 | regno, |
| 560 | frame); |
| 561 | |
| 562 | if (regval == NULL) |
| 563 | error ("Value of register variable not available."); |
| 564 | |
| 565 | addr = value_as_address (regval); |
| 566 | VALUE_LVAL (v) = lval_memory; |
| 567 | } |
| 568 | else |
| 569 | { |
| 570 | regval = value_from_register (type, regno, frame); |
| 571 | |
| 572 | if (regval == NULL) |
| 573 | error ("Value of register variable not available."); |
| 574 | return regval; |
| 575 | } |
| 576 | } |
| 577 | break; |
| 578 | |
| 579 | case LOC_UNRESOLVED: |
| 580 | { |
| 581 | struct minimal_symbol *msym; |
| 582 | |
| 583 | msym = lookup_minimal_symbol (SYMBOL_NAME (var), NULL, NULL); |
| 584 | if (msym == NULL) |
| 585 | return 0; |
| 586 | if (overlay_debugging) |
| 587 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), |
| 588 | SYMBOL_BFD_SECTION (msym)); |
| 589 | else |
| 590 | addr = SYMBOL_VALUE_ADDRESS (msym); |
| 591 | } |
| 592 | break; |
| 593 | |
| 594 | case LOC_OPTIMIZED_OUT: |
| 595 | VALUE_LVAL (v) = not_lval; |
| 596 | VALUE_OPTIMIZED_OUT (v) = 1; |
| 597 | return v; |
| 598 | |
| 599 | default: |
| 600 | error ("Cannot look up value of a botched symbol."); |
| 601 | break; |
| 602 | } |
| 603 | |
| 604 | VALUE_ADDRESS (v) = addr; |
| 605 | VALUE_LAZY (v) = 1; |
| 606 | return v; |
| 607 | } |
| 608 | |
| 609 | /* Return a value of type TYPE, stored in register REGNUM, in frame |
| 610 | FRAME. |
| 611 | |
| 612 | NOTE: returns NULL if register value is not available. |
| 613 | Caller will check return value or die! */ |
| 614 | |
| 615 | struct value * |
| 616 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
| 617 | { |
| 618 | char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE); |
| 619 | CORE_ADDR addr; |
| 620 | int optim; |
| 621 | struct value *v = allocate_value (type); |
| 622 | char *value_bytes = 0; |
| 623 | int value_bytes_copied = 0; |
| 624 | int num_storage_locs; |
| 625 | enum lval_type lval; |
| 626 | int len; |
| 627 | |
| 628 | CHECK_TYPEDEF (type); |
| 629 | len = TYPE_LENGTH (type); |
| 630 | |
| 631 | VALUE_REGNO (v) = regnum; |
| 632 | |
| 633 | num_storage_locs = (len > REGISTER_VIRTUAL_SIZE (regnum) ? |
| 634 | ((len - 1) / REGISTER_RAW_SIZE (regnum)) + 1 : |
| 635 | 1); |
| 636 | |
| 637 | if (num_storage_locs > 1 |
| 638 | #ifdef GDB_TARGET_IS_H8500 |
| 639 | || TYPE_CODE (type) == TYPE_CODE_PTR |
| 640 | #endif |
| 641 | ) |
| 642 | { |
| 643 | /* Value spread across multiple storage locations. */ |
| 644 | |
| 645 | int local_regnum; |
| 646 | int mem_stor = 0, reg_stor = 0; |
| 647 | int mem_tracking = 1; |
| 648 | CORE_ADDR last_addr = 0; |
| 649 | CORE_ADDR first_addr = 0; |
| 650 | |
| 651 | value_bytes = (char *) alloca (len + MAX_REGISTER_RAW_SIZE); |
| 652 | |
| 653 | /* Copy all of the data out, whereever it may be. */ |
| 654 | |
| 655 | #ifdef GDB_TARGET_IS_H8500 |
| 656 | /* This piece of hideosity is required because the H8500 treats registers |
| 657 | differently depending upon whether they are used as pointers or not. As a |
| 658 | pointer, a register needs to have a page register tacked onto the front. |
| 659 | An alternate way to do this would be to have gcc output different register |
| 660 | numbers for the pointer & non-pointer form of the register. But, it |
| 661 | doesn't, so we're stuck with this. */ |
| 662 | |
| 663 | if (TYPE_CODE (type) == TYPE_CODE_PTR |
| 664 | && len > 2) |
| 665 | { |
| 666 | int page_regnum; |
| 667 | |
| 668 | switch (regnum) |
| 669 | { |
| 670 | case R0_REGNUM: |
| 671 | case R1_REGNUM: |
| 672 | case R2_REGNUM: |
| 673 | case R3_REGNUM: |
| 674 | page_regnum = SEG_D_REGNUM; |
| 675 | break; |
| 676 | case R4_REGNUM: |
| 677 | case R5_REGNUM: |
| 678 | page_regnum = SEG_E_REGNUM; |
| 679 | break; |
| 680 | case R6_REGNUM: |
| 681 | case R7_REGNUM: |
| 682 | page_regnum = SEG_T_REGNUM; |
| 683 | break; |
| 684 | } |
| 685 | |
| 686 | value_bytes[0] = 0; |
| 687 | get_saved_register (value_bytes + 1, |
| 688 | &optim, |
| 689 | &addr, |
| 690 | frame, |
| 691 | page_regnum, |
| 692 | &lval); |
| 693 | |
| 694 | if (register_cached (page_regnum) == -1) |
| 695 | return NULL; /* register value not available */ |
| 696 | |
| 697 | if (lval == lval_register) |
| 698 | reg_stor++; |
| 699 | else |
| 700 | mem_stor++; |
| 701 | first_addr = addr; |
| 702 | last_addr = addr; |
| 703 | |
| 704 | get_saved_register (value_bytes + 2, |
| 705 | &optim, |
| 706 | &addr, |
| 707 | frame, |
| 708 | regnum, |
| 709 | &lval); |
| 710 | |
| 711 | if (register_cached (regnum) == -1) |
| 712 | return NULL; /* register value not available */ |
| 713 | |
| 714 | if (lval == lval_register) |
| 715 | reg_stor++; |
| 716 | else |
| 717 | { |
| 718 | mem_stor++; |
| 719 | mem_tracking = mem_tracking && (addr == last_addr); |
| 720 | } |
| 721 | last_addr = addr; |
| 722 | } |
| 723 | else |
| 724 | #endif /* GDB_TARGET_IS_H8500 */ |
| 725 | for (local_regnum = regnum; |
| 726 | value_bytes_copied < len; |
| 727 | (value_bytes_copied += REGISTER_RAW_SIZE (local_regnum), |
| 728 | ++local_regnum)) |
| 729 | { |
| 730 | get_saved_register (value_bytes + value_bytes_copied, |
| 731 | &optim, |
| 732 | &addr, |
| 733 | frame, |
| 734 | local_regnum, |
| 735 | &lval); |
| 736 | |
| 737 | if (register_cached (local_regnum) == -1) |
| 738 | return NULL; /* register value not available */ |
| 739 | |
| 740 | if (regnum == local_regnum) |
| 741 | first_addr = addr; |
| 742 | if (lval == lval_register) |
| 743 | reg_stor++; |
| 744 | else |
| 745 | { |
| 746 | mem_stor++; |
| 747 | |
| 748 | mem_tracking = |
| 749 | (mem_tracking |
| 750 | && (regnum == local_regnum |
| 751 | || addr == last_addr)); |
| 752 | } |
| 753 | last_addr = addr; |
| 754 | } |
| 755 | |
| 756 | if ((reg_stor && mem_stor) |
| 757 | || (mem_stor && !mem_tracking)) |
| 758 | /* Mixed storage; all of the hassle we just went through was |
| 759 | for some good purpose. */ |
| 760 | { |
| 761 | VALUE_LVAL (v) = lval_reg_frame_relative; |
| 762 | VALUE_FRAME (v) = FRAME_FP (frame); |
| 763 | VALUE_FRAME_REGNUM (v) = regnum; |
| 764 | } |
| 765 | else if (mem_stor) |
| 766 | { |
| 767 | VALUE_LVAL (v) = lval_memory; |
| 768 | VALUE_ADDRESS (v) = first_addr; |
| 769 | } |
| 770 | else if (reg_stor) |
| 771 | { |
| 772 | VALUE_LVAL (v) = lval_register; |
| 773 | VALUE_ADDRESS (v) = first_addr; |
| 774 | } |
| 775 | else |
| 776 | internal_error (__FILE__, __LINE__, |
| 777 | "value_from_register: Value not stored anywhere!"); |
| 778 | |
| 779 | VALUE_OPTIMIZED_OUT (v) = optim; |
| 780 | |
| 781 | /* Any structure stored in more than one register will always be |
| 782 | an integral number of registers. Otherwise, you'd need to do |
| 783 | some fiddling with the last register copied here for little |
| 784 | endian machines. */ |
| 785 | |
| 786 | /* Copy into the contents section of the value. */ |
| 787 | memcpy (VALUE_CONTENTS_RAW (v), value_bytes, len); |
| 788 | |
| 789 | /* Finally do any conversion necessary when extracting this |
| 790 | type from more than one register. */ |
| 791 | #ifdef REGISTER_CONVERT_TO_TYPE |
| 792 | REGISTER_CONVERT_TO_TYPE (regnum, type, VALUE_CONTENTS_RAW (v)); |
| 793 | #endif |
| 794 | return v; |
| 795 | } |
| 796 | |
| 797 | /* Data is completely contained within a single register. Locate the |
| 798 | register's contents in a real register or in core; |
| 799 | read the data in raw format. */ |
| 800 | |
| 801 | get_saved_register (raw_buffer, &optim, &addr, frame, regnum, &lval); |
| 802 | |
| 803 | if (register_cached (regnum) == -1) |
| 804 | return NULL; /* register value not available */ |
| 805 | |
| 806 | VALUE_OPTIMIZED_OUT (v) = optim; |
| 807 | VALUE_LVAL (v) = lval; |
| 808 | VALUE_ADDRESS (v) = addr; |
| 809 | |
| 810 | /* Convert raw data to virtual format if necessary. */ |
| 811 | |
| 812 | if (REGISTER_CONVERTIBLE (regnum)) |
| 813 | { |
| 814 | REGISTER_CONVERT_TO_VIRTUAL (regnum, type, |
| 815 | raw_buffer, VALUE_CONTENTS_RAW (v)); |
| 816 | } |
| 817 | else |
| 818 | { |
| 819 | /* Raw and virtual formats are the same for this register. */ |
| 820 | |
| 821 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG && len < REGISTER_RAW_SIZE (regnum)) |
| 822 | { |
| 823 | /* Big-endian, and we want less than full size. */ |
| 824 | VALUE_OFFSET (v) = REGISTER_RAW_SIZE (regnum) - len; |
| 825 | } |
| 826 | |
| 827 | memcpy (VALUE_CONTENTS_RAW (v), raw_buffer + VALUE_OFFSET (v), len); |
| 828 | } |
| 829 | |
| 830 | return v; |
| 831 | } |
| 832 | \f |
| 833 | /* Given a struct symbol for a variable or function, |
| 834 | and a stack frame id, |
| 835 | return a (pointer to a) struct value containing the properly typed |
| 836 | address. */ |
| 837 | |
| 838 | struct value * |
| 839 | locate_var_value (register struct symbol *var, struct frame_info *frame) |
| 840 | { |
| 841 | CORE_ADDR addr = 0; |
| 842 | struct type *type = SYMBOL_TYPE (var); |
| 843 | struct value *lazy_value; |
| 844 | |
| 845 | /* Evaluate it first; if the result is a memory address, we're fine. |
| 846 | Lazy evaluation pays off here. */ |
| 847 | |
| 848 | lazy_value = read_var_value (var, frame); |
| 849 | if (lazy_value == 0) |
| 850 | error ("Address of \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var)); |
| 851 | |
| 852 | if (VALUE_LAZY (lazy_value) |
| 853 | || TYPE_CODE (type) == TYPE_CODE_FUNC) |
| 854 | { |
| 855 | struct value *val; |
| 856 | |
| 857 | addr = VALUE_ADDRESS (lazy_value); |
| 858 | val = value_from_pointer (lookup_pointer_type (type), addr); |
| 859 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (lazy_value); |
| 860 | return val; |
| 861 | } |
| 862 | |
| 863 | /* Not a memory address; check what the problem was. */ |
| 864 | switch (VALUE_LVAL (lazy_value)) |
| 865 | { |
| 866 | case lval_register: |
| 867 | gdb_assert (REGISTER_NAME (VALUE_REGNO (lazy_value)) != NULL |
| 868 | && *REGISTER_NAME (VALUE_REGNO (lazy_value)) != '\0'); |
| 869 | error("Address requested for identifier " |
| 870 | "\"%s\" which is in register $%s", |
| 871 | SYMBOL_SOURCE_NAME (var), |
| 872 | REGISTER_NAME (VALUE_REGNO (lazy_value))); |
| 873 | break; |
| 874 | |
| 875 | case lval_reg_frame_relative: |
| 876 | gdb_assert (REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != NULL |
| 877 | && *REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != '\0'); |
| 878 | error("Address requested for identifier " |
| 879 | "\"%s\" which is in frame register $%s", |
| 880 | SYMBOL_SOURCE_NAME (var), |
| 881 | REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value))); |
| 882 | break; |
| 883 | |
| 884 | default: |
| 885 | error ("Can't take address of \"%s\" which isn't an lvalue.", |
| 886 | SYMBOL_SOURCE_NAME (var)); |
| 887 | break; |
| 888 | } |
| 889 | return 0; /* For lint -- never reached */ |
| 890 | } |