| 1 | /* Find a variable's value in memory, for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1987, 1989, 1991 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "symtab.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "frame.h" |
| 24 | #include "value.h" |
| 25 | #include "gdbcore.h" |
| 26 | #include "inferior.h" |
| 27 | #include "target.h" |
| 28 | |
| 29 | /* Basic byte-swapping routines. GDB has needed these for a long time... |
| 30 | All extract a target-format integer at ADDR which is LEN bytes long. */ |
| 31 | |
| 32 | #if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8 |
| 33 | /* 8 bit characters are a pretty safe assumption these days, so we |
| 34 | assume it throughout all these swapping routines. If we had to deal with |
| 35 | 9 bit characters, we would need to make len be in bits and would have |
| 36 | to re-write these routines... */ |
| 37 | you lose |
| 38 | #endif |
| 39 | |
| 40 | LONGEST |
| 41 | extract_signed_integer (addr, len) |
| 42 | PTR addr; |
| 43 | int len; |
| 44 | { |
| 45 | LONGEST retval; |
| 46 | unsigned char *p; |
| 47 | unsigned char *startaddr = (unsigned char *)addr; |
| 48 | unsigned char *endaddr = startaddr + len; |
| 49 | |
| 50 | if (len > sizeof (LONGEST)) |
| 51 | error ("\ |
| 52 | That operation is not available on integers of more than %d bytes.", |
| 53 | sizeof (LONGEST)); |
| 54 | |
| 55 | /* Start at the most significant end of the integer, and work towards |
| 56 | the least significant. */ |
| 57 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 58 | p = startaddr; |
| 59 | #else |
| 60 | p = endaddr - 1; |
| 61 | #endif |
| 62 | /* Do the sign extension once at the start. */ |
| 63 | retval = ((LONGEST)*p ^ 0x80) - 0x80; |
| 64 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 65 | for (++p; p < endaddr; ++p) |
| 66 | #else |
| 67 | for (--p; p >= startaddr; --p) |
| 68 | #endif |
| 69 | { |
| 70 | retval = (retval << 8) | *p; |
| 71 | } |
| 72 | return retval; |
| 73 | } |
| 74 | |
| 75 | unsigned LONGEST |
| 76 | extract_unsigned_integer (addr, len) |
| 77 | PTR addr; |
| 78 | int len; |
| 79 | { |
| 80 | unsigned LONGEST retval; |
| 81 | unsigned char *p; |
| 82 | unsigned char *startaddr = (unsigned char *)addr; |
| 83 | unsigned char *endaddr = startaddr + len; |
| 84 | |
| 85 | if (len > sizeof (unsigned LONGEST)) |
| 86 | error ("\ |
| 87 | That operation is not available on integers of more than %d bytes.", |
| 88 | sizeof (unsigned LONGEST)); |
| 89 | |
| 90 | /* Start at the most significant end of the integer, and work towards |
| 91 | the least significant. */ |
| 92 | retval = 0; |
| 93 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 94 | for (p = startaddr; p < endaddr; ++p) |
| 95 | #else |
| 96 | for (p = endaddr - 1; p >= startaddr; --p) |
| 97 | #endif |
| 98 | { |
| 99 | retval = (retval << 8) | *p; |
| 100 | } |
| 101 | return retval; |
| 102 | } |
| 103 | |
| 104 | CORE_ADDR |
| 105 | extract_address (addr, len) |
| 106 | PTR addr; |
| 107 | int len; |
| 108 | { |
| 109 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 110 | whether we want this to be true eventually. */ |
| 111 | return extract_unsigned_integer (addr, len); |
| 112 | } |
| 113 | |
| 114 | void |
| 115 | store_signed_integer (addr, len, val) |
| 116 | PTR addr; |
| 117 | int len; |
| 118 | LONGEST val; |
| 119 | { |
| 120 | unsigned char *p; |
| 121 | unsigned char *startaddr = (unsigned char *)addr; |
| 122 | unsigned char *endaddr = startaddr + len; |
| 123 | |
| 124 | /* Start at the least significant end of the integer, and work towards |
| 125 | the most significant. */ |
| 126 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 127 | for (p = endaddr - 1; p >= startaddr; --p) |
| 128 | #else |
| 129 | for (p = startaddr; p < endaddr; ++p) |
| 130 | #endif |
| 131 | { |
| 132 | *p = val & 0xff; |
| 133 | val >>= 8; |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | void |
| 138 | store_unsigned_integer (addr, len, val) |
| 139 | PTR addr; |
| 140 | int len; |
| 141 | unsigned LONGEST val; |
| 142 | { |
| 143 | unsigned char *p; |
| 144 | unsigned char *startaddr = (unsigned char *)addr; |
| 145 | unsigned char *endaddr = startaddr + len; |
| 146 | |
| 147 | /* Start at the least significant end of the integer, and work towards |
| 148 | the most significant. */ |
| 149 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 150 | for (p = endaddr - 1; p >= startaddr; --p) |
| 151 | #else |
| 152 | for (p = startaddr; p < endaddr; ++p) |
| 153 | #endif |
| 154 | { |
| 155 | *p = val & 0xff; |
| 156 | val >>= 8; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | void |
| 161 | store_address (addr, len, val) |
| 162 | PTR addr; |
| 163 | int len; |
| 164 | CORE_ADDR val; |
| 165 | { |
| 166 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure |
| 167 | whether we want this to be true eventually. */ |
| 168 | store_unsigned_integer (addr, len, (LONGEST)val); |
| 169 | } |
| 170 | \f |
| 171 | #if !defined (GET_SAVED_REGISTER) |
| 172 | |
| 173 | /* Return the address in which frame FRAME's value of register REGNUM |
| 174 | has been saved in memory. Or return zero if it has not been saved. |
| 175 | If REGNUM specifies the SP, the value we return is actually |
| 176 | the SP value, not an address where it was saved. */ |
| 177 | |
| 178 | CORE_ADDR |
| 179 | find_saved_register (frame, regnum) |
| 180 | FRAME frame; |
| 181 | int regnum; |
| 182 | { |
| 183 | struct frame_info *fi; |
| 184 | struct frame_saved_regs saved_regs; |
| 185 | |
| 186 | register FRAME frame1 = 0; |
| 187 | register CORE_ADDR addr = 0; |
| 188 | |
| 189 | if (frame == 0) /* No regs saved if want current frame */ |
| 190 | return 0; |
| 191 | |
| 192 | #ifdef HAVE_REGISTER_WINDOWS |
| 193 | /* We assume that a register in a register window will only be saved |
| 194 | in one place (since the name changes and/or disappears as you go |
| 195 | towards inner frames), so we only call get_frame_saved_regs on |
| 196 | the current frame. This is directly in contradiction to the |
| 197 | usage below, which assumes that registers used in a frame must be |
| 198 | saved in a lower (more interior) frame. This change is a result |
| 199 | of working on a register window machine; get_frame_saved_regs |
| 200 | always returns the registers saved within a frame, within the |
| 201 | context (register namespace) of that frame. */ |
| 202 | |
| 203 | /* However, note that we don't want this to return anything if |
| 204 | nothing is saved (if there's a frame inside of this one). Also, |
| 205 | callers to this routine asking for the stack pointer want the |
| 206 | stack pointer saved for *this* frame; this is returned from the |
| 207 | next frame. */ |
| 208 | |
| 209 | |
| 210 | if (REGISTER_IN_WINDOW_P(regnum)) |
| 211 | { |
| 212 | frame1 = get_next_frame (frame); |
| 213 | if (!frame1) return 0; /* Registers of this frame are |
| 214 | active. */ |
| 215 | |
| 216 | /* Get the SP from the next frame in; it will be this |
| 217 | current frame. */ |
| 218 | if (regnum != SP_REGNUM) |
| 219 | frame1 = frame; |
| 220 | |
| 221 | fi = get_frame_info (frame1); |
| 222 | get_frame_saved_regs (fi, &saved_regs); |
| 223 | return saved_regs.regs[regnum]; /* ... which might be zero */ |
| 224 | } |
| 225 | #endif /* HAVE_REGISTER_WINDOWS */ |
| 226 | |
| 227 | /* Note that this next routine assumes that registers used in |
| 228 | frame x will be saved only in the frame that x calls and |
| 229 | frames interior to it. This is not true on the sparc, but the |
| 230 | above macro takes care of it, so we should be all right. */ |
| 231 | while (1) |
| 232 | { |
| 233 | QUIT; |
| 234 | frame1 = get_prev_frame (frame1); |
| 235 | if (frame1 == 0 || frame1 == frame) |
| 236 | break; |
| 237 | fi = get_frame_info (frame1); |
| 238 | get_frame_saved_regs (fi, &saved_regs); |
| 239 | if (saved_regs.regs[regnum]) |
| 240 | addr = saved_regs.regs[regnum]; |
| 241 | } |
| 242 | |
| 243 | return addr; |
| 244 | } |
| 245 | |
| 246 | /* Find register number REGNUM relative to FRAME and put its (raw, |
| 247 | target format) contents in *RAW_BUFFER. Set *OPTIMIZED if the |
| 248 | variable was optimized out (and thus can't be fetched). Set *LVAL |
| 249 | to lval_memory, lval_register, or not_lval, depending on whether |
| 250 | the value was fetched from memory, from a register, or in a strange |
| 251 | and non-modifiable way (e.g. a frame pointer which was calculated |
| 252 | rather than fetched). Set *ADDRP to the address, either in memory |
| 253 | on as a REGISTER_BYTE offset into the registers array. |
| 254 | |
| 255 | Note that this implementation never sets *LVAL to not_lval. But |
| 256 | it can be replaced by defining GET_SAVED_REGISTER and supplying |
| 257 | your own. |
| 258 | |
| 259 | The argument RAW_BUFFER must point to aligned memory. */ |
| 260 | |
| 261 | void |
| 262 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) |
| 263 | char *raw_buffer; |
| 264 | int *optimized; |
| 265 | CORE_ADDR *addrp; |
| 266 | FRAME frame; |
| 267 | int regnum; |
| 268 | enum lval_type *lval; |
| 269 | { |
| 270 | CORE_ADDR addr; |
| 271 | /* Normal systems don't optimize out things with register numbers. */ |
| 272 | if (optimized != NULL) |
| 273 | *optimized = 0; |
| 274 | addr = find_saved_register (frame, regnum); |
| 275 | if (addr != 0) |
| 276 | { |
| 277 | if (lval != NULL) |
| 278 | *lval = lval_memory; |
| 279 | if (regnum == SP_REGNUM) |
| 280 | { |
| 281 | if (raw_buffer != NULL) |
| 282 | { |
| 283 | /* Put it back in target format. */ |
| 284 | store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), addr); |
| 285 | } |
| 286 | if (addrp != NULL) |
| 287 | *addrp = 0; |
| 288 | return; |
| 289 | } |
| 290 | if (raw_buffer != NULL) |
| 291 | read_memory (addr, raw_buffer, REGISTER_RAW_SIZE (regnum)); |
| 292 | } |
| 293 | else |
| 294 | { |
| 295 | if (lval != NULL) |
| 296 | *lval = lval_register; |
| 297 | addr = REGISTER_BYTE (regnum); |
| 298 | if (raw_buffer != NULL) |
| 299 | read_register_gen (regnum, raw_buffer); |
| 300 | } |
| 301 | if (addrp != NULL) |
| 302 | *addrp = addr; |
| 303 | } |
| 304 | #endif /* GET_SAVED_REGISTER. */ |
| 305 | |
| 306 | /* Copy the bytes of register REGNUM, relative to the current stack frame, |
| 307 | into our memory at MYADDR, in target byte order. |
| 308 | The number of bytes copied is REGISTER_RAW_SIZE (REGNUM). |
| 309 | |
| 310 | Returns 1 if could not be read, 0 if could. */ |
| 311 | |
| 312 | int |
| 313 | read_relative_register_raw_bytes (regnum, myaddr) |
| 314 | int regnum; |
| 315 | char *myaddr; |
| 316 | { |
| 317 | int optim; |
| 318 | if (regnum == FP_REGNUM && selected_frame) |
| 319 | { |
| 320 | /* Put it back in target format. */ |
| 321 | store_address (myaddr, REGISTER_RAW_SIZE(FP_REGNUM), |
| 322 | FRAME_FP(selected_frame)); |
| 323 | return 0; |
| 324 | } |
| 325 | |
| 326 | get_saved_register (myaddr, &optim, (CORE_ADDR *) NULL, selected_frame, |
| 327 | regnum, (enum lval_type *)NULL); |
| 328 | return optim; |
| 329 | } |
| 330 | |
| 331 | /* Return a `value' with the contents of register REGNUM |
| 332 | in its virtual format, with the type specified by |
| 333 | REGISTER_VIRTUAL_TYPE. */ |
| 334 | |
| 335 | value |
| 336 | value_of_register (regnum) |
| 337 | int regnum; |
| 338 | { |
| 339 | CORE_ADDR addr; |
| 340 | int optim; |
| 341 | register value val; |
| 342 | char raw_buffer[MAX_REGISTER_RAW_SIZE]; |
| 343 | char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE]; |
| 344 | enum lval_type lval; |
| 345 | |
| 346 | get_saved_register (raw_buffer, &optim, &addr, |
| 347 | selected_frame, regnum, &lval); |
| 348 | |
| 349 | REGISTER_CONVERT_TO_VIRTUAL (regnum, raw_buffer, virtual_buffer); |
| 350 | val = allocate_value (REGISTER_VIRTUAL_TYPE (regnum)); |
| 351 | memcpy (VALUE_CONTENTS_RAW (val), virtual_buffer, |
| 352 | REGISTER_VIRTUAL_SIZE (regnum)); |
| 353 | VALUE_LVAL (val) = lval; |
| 354 | VALUE_ADDRESS (val) = addr; |
| 355 | VALUE_REGNO (val) = regnum; |
| 356 | VALUE_OPTIMIZED_OUT (val) = optim; |
| 357 | return val; |
| 358 | } |
| 359 | \f |
| 360 | /* Low level examining and depositing of registers. |
| 361 | |
| 362 | The caller is responsible for making |
| 363 | sure that the inferior is stopped before calling the fetching routines, |
| 364 | or it will get garbage. (a change from GDB version 3, in which |
| 365 | the caller got the value from the last stop). */ |
| 366 | |
| 367 | /* Contents of the registers in target byte order. |
| 368 | We allocate some extra slop since we do a lot of memcpy's around `registers', |
| 369 | and failing-soft is better than failing hard. */ |
| 370 | char registers[REGISTER_BYTES + /* SLOP */ 256]; |
| 371 | |
| 372 | /* Nonzero if that register has been fetched. */ |
| 373 | char register_valid[NUM_REGS]; |
| 374 | |
| 375 | /* Indicate that registers may have changed, so invalidate the cache. */ |
| 376 | void |
| 377 | registers_changed () |
| 378 | { |
| 379 | int i; |
| 380 | for (i = 0; i < NUM_REGS; i++) |
| 381 | register_valid[i] = 0; |
| 382 | } |
| 383 | |
| 384 | /* Indicate that all registers have been fetched, so mark them all valid. */ |
| 385 | void |
| 386 | registers_fetched () |
| 387 | { |
| 388 | int i; |
| 389 | for (i = 0; i < NUM_REGS; i++) |
| 390 | register_valid[i] = 1; |
| 391 | } |
| 392 | |
| 393 | /* Copy LEN bytes of consecutive data from registers |
| 394 | starting with the REGBYTE'th byte of register data |
| 395 | into memory at MYADDR. */ |
| 396 | |
| 397 | void |
| 398 | read_register_bytes (regbyte, myaddr, len) |
| 399 | int regbyte; |
| 400 | char *myaddr; |
| 401 | int len; |
| 402 | { |
| 403 | /* Fetch all registers. */ |
| 404 | int i; |
| 405 | for (i = 0; i < NUM_REGS; i++) |
| 406 | if (!register_valid[i]) |
| 407 | { |
| 408 | target_fetch_registers (-1); |
| 409 | break; |
| 410 | } |
| 411 | if (myaddr != NULL) |
| 412 | memcpy (myaddr, ®isters[regbyte], len); |
| 413 | } |
| 414 | |
| 415 | /* Read register REGNO into memory at MYADDR, which must be large enough |
| 416 | for REGISTER_RAW_BYTES (REGNO). Target byte-order. |
| 417 | If the register is known to be the size of a CORE_ADDR or smaller, |
| 418 | read_register can be used instead. */ |
| 419 | void |
| 420 | read_register_gen (regno, myaddr) |
| 421 | int regno; |
| 422 | char *myaddr; |
| 423 | { |
| 424 | if (!register_valid[regno]) |
| 425 | target_fetch_registers (regno); |
| 426 | memcpy (myaddr, ®isters[REGISTER_BYTE (regno)], |
| 427 | REGISTER_RAW_SIZE (regno)); |
| 428 | } |
| 429 | |
| 430 | /* Copy LEN bytes of consecutive data from memory at MYADDR |
| 431 | into registers starting with the REGBYTE'th byte of register data. */ |
| 432 | |
| 433 | void |
| 434 | write_register_bytes (regbyte, myaddr, len) |
| 435 | int regbyte; |
| 436 | char *myaddr; |
| 437 | int len; |
| 438 | { |
| 439 | /* Make sure the entire registers array is valid. */ |
| 440 | read_register_bytes (0, (char *)NULL, REGISTER_BYTES); |
| 441 | memcpy (®isters[regbyte], myaddr, len); |
| 442 | target_store_registers (-1); |
| 443 | } |
| 444 | |
| 445 | /* Return the raw contents of register REGNO, regarding it as an integer. */ |
| 446 | /* This probably should be returning LONGEST rather than CORE_ADDR. */ |
| 447 | |
| 448 | CORE_ADDR |
| 449 | read_register (regno) |
| 450 | int regno; |
| 451 | { |
| 452 | if (!register_valid[regno]) |
| 453 | target_fetch_registers (regno); |
| 454 | |
| 455 | return extract_address (®isters[REGISTER_BYTE (regno)], |
| 456 | REGISTER_RAW_SIZE(regno)); |
| 457 | } |
| 458 | |
| 459 | /* Registers we shouldn't try to store. */ |
| 460 | #if !defined (CANNOT_STORE_REGISTER) |
| 461 | #define CANNOT_STORE_REGISTER(regno) 0 |
| 462 | #endif |
| 463 | |
| 464 | /* Store VALUE, into the raw contents of register number REGNO. */ |
| 465 | /* FIXME: The val arg should probably be a LONGEST. */ |
| 466 | |
| 467 | void |
| 468 | write_register (regno, val) |
| 469 | int regno; |
| 470 | long val; |
| 471 | { |
| 472 | PTR buf; |
| 473 | int size; |
| 474 | |
| 475 | /* On the sparc, writing %g0 is a no-op, so we don't even want to change |
| 476 | the registers array if something writes to this register. */ |
| 477 | if (CANNOT_STORE_REGISTER (regno)) |
| 478 | return; |
| 479 | |
| 480 | size = REGISTER_RAW_SIZE(regno); |
| 481 | buf = alloca (size); |
| 482 | store_signed_integer (buf, size, (LONGEST) val); |
| 483 | |
| 484 | /* If we have a valid copy of the register, and new value == old value, |
| 485 | then don't bother doing the actual store. */ |
| 486 | |
| 487 | if (register_valid [regno]) |
| 488 | { |
| 489 | if (memcmp (®isters[REGISTER_BYTE (regno)], buf, size) == 0) |
| 490 | return; |
| 491 | } |
| 492 | |
| 493 | target_prepare_to_store (); |
| 494 | |
| 495 | memcpy (®isters[REGISTER_BYTE (regno)], buf, size); |
| 496 | |
| 497 | register_valid [regno] = 1; |
| 498 | |
| 499 | target_store_registers (regno); |
| 500 | } |
| 501 | |
| 502 | /* Record that register REGNO contains VAL. |
| 503 | This is used when the value is obtained from the inferior or core dump, |
| 504 | so there is no need to store the value there. */ |
| 505 | |
| 506 | void |
| 507 | supply_register (regno, val) |
| 508 | int regno; |
| 509 | char *val; |
| 510 | { |
| 511 | register_valid[regno] = 1; |
| 512 | memcpy (®isters[REGISTER_BYTE (regno)], val, REGISTER_RAW_SIZE (regno)); |
| 513 | |
| 514 | /* On some architectures, e.g. HPPA, there are a few stray bits in some |
| 515 | registers, that the rest of the code would like to ignore. */ |
| 516 | #ifdef CLEAN_UP_REGISTER_VALUE |
| 517 | CLEAN_UP_REGISTER_VALUE(regno, ®isters[REGISTER_BYTE(regno)]); |
| 518 | #endif |
| 519 | } |
| 520 | \f |
| 521 | /* Given a struct symbol for a variable, |
| 522 | and a stack frame id, read the value of the variable |
| 523 | and return a (pointer to a) struct value containing the value. |
| 524 | If the variable cannot be found, return a zero pointer. |
| 525 | If FRAME is NULL, use the selected_frame. */ |
| 526 | |
| 527 | value |
| 528 | read_var_value (var, frame) |
| 529 | register struct symbol *var; |
| 530 | FRAME frame; |
| 531 | { |
| 532 | register value v; |
| 533 | struct frame_info *fi; |
| 534 | struct type *type = SYMBOL_TYPE (var); |
| 535 | CORE_ADDR addr; |
| 536 | register int len; |
| 537 | |
| 538 | v = allocate_value (type); |
| 539 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ |
| 540 | len = TYPE_LENGTH (type); |
| 541 | |
| 542 | if (frame == 0) frame = selected_frame; |
| 543 | |
| 544 | switch (SYMBOL_CLASS (var)) |
| 545 | { |
| 546 | case LOC_CONST: |
| 547 | /* Put the constant back in target format. */ |
| 548 | store_signed_integer (VALUE_CONTENTS_RAW (v), len, |
| 549 | (LONGEST) SYMBOL_VALUE (var)); |
| 550 | VALUE_LVAL (v) = not_lval; |
| 551 | return v; |
| 552 | |
| 553 | case LOC_LABEL: |
| 554 | /* Put the constant back in target format. */ |
| 555 | store_address (VALUE_CONTENTS_RAW (v), len, SYMBOL_VALUE_ADDRESS (var)); |
| 556 | VALUE_LVAL (v) = not_lval; |
| 557 | return v; |
| 558 | |
| 559 | case LOC_CONST_BYTES: |
| 560 | { |
| 561 | char *bytes_addr; |
| 562 | bytes_addr = SYMBOL_VALUE_BYTES (var); |
| 563 | memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len); |
| 564 | VALUE_LVAL (v) = not_lval; |
| 565 | return v; |
| 566 | } |
| 567 | |
| 568 | case LOC_STATIC: |
| 569 | addr = SYMBOL_VALUE_ADDRESS (var); |
| 570 | break; |
| 571 | |
| 572 | case LOC_ARG: |
| 573 | fi = get_frame_info (frame); |
| 574 | if (fi == NULL) |
| 575 | return 0; |
| 576 | addr = FRAME_ARGS_ADDRESS (fi); |
| 577 | if (!addr) |
| 578 | { |
| 579 | return 0; |
| 580 | } |
| 581 | addr += SYMBOL_VALUE (var); |
| 582 | break; |
| 583 | |
| 584 | case LOC_REF_ARG: |
| 585 | fi = get_frame_info (frame); |
| 586 | if (fi == NULL) |
| 587 | return 0; |
| 588 | addr = FRAME_ARGS_ADDRESS (fi); |
| 589 | if (!addr) |
| 590 | { |
| 591 | return 0; |
| 592 | } |
| 593 | addr += SYMBOL_VALUE (var); |
| 594 | addr = read_memory_unsigned_integer |
| 595 | (addr, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 596 | break; |
| 597 | |
| 598 | case LOC_LOCAL: |
| 599 | case LOC_LOCAL_ARG: |
| 600 | fi = get_frame_info (frame); |
| 601 | if (fi == NULL) |
| 602 | return 0; |
| 603 | addr = FRAME_LOCALS_ADDRESS (fi); |
| 604 | addr += SYMBOL_VALUE (var); |
| 605 | break; |
| 606 | |
| 607 | case LOC_BASEREG: |
| 608 | case LOC_BASEREG_ARG: |
| 609 | { |
| 610 | char buf[MAX_REGISTER_RAW_SIZE]; |
| 611 | get_saved_register (buf, NULL, NULL, frame, SYMBOL_BASEREG (var), |
| 612 | NULL); |
| 613 | addr = extract_address (buf, REGISTER_RAW_SIZE (SYMBOL_BASEREG (var))); |
| 614 | addr += SYMBOL_VALUE (var); |
| 615 | break; |
| 616 | } |
| 617 | |
| 618 | case LOC_TYPEDEF: |
| 619 | error ("Cannot look up value of a typedef"); |
| 620 | break; |
| 621 | |
| 622 | case LOC_BLOCK: |
| 623 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); |
| 624 | return v; |
| 625 | |
| 626 | case LOC_REGISTER: |
| 627 | case LOC_REGPARM: |
| 628 | case LOC_REGPARM_ADDR: |
| 629 | { |
| 630 | struct block *b; |
| 631 | |
| 632 | if (frame == NULL) |
| 633 | return 0; |
| 634 | b = get_frame_block (frame); |
| 635 | |
| 636 | v = value_from_register (type, SYMBOL_VALUE (var), frame); |
| 637 | |
| 638 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) |
| 639 | { |
| 640 | addr = *(CORE_ADDR *)VALUE_CONTENTS (v); |
| 641 | VALUE_LVAL (v) = lval_memory; |
| 642 | } |
| 643 | else |
| 644 | return v; |
| 645 | } |
| 646 | break; |
| 647 | |
| 648 | case LOC_OPTIMIZED_OUT: |
| 649 | VALUE_LVAL (v) = not_lval; |
| 650 | VALUE_OPTIMIZED_OUT (v) = 1; |
| 651 | return v; |
| 652 | |
| 653 | default: |
| 654 | error ("Cannot look up value of a botched symbol."); |
| 655 | break; |
| 656 | } |
| 657 | |
| 658 | VALUE_ADDRESS (v) = addr; |
| 659 | VALUE_LAZY (v) = 1; |
| 660 | return v; |
| 661 | } |
| 662 | |
| 663 | /* Return a value of type TYPE, stored in register REGNUM, in frame |
| 664 | FRAME. */ |
| 665 | |
| 666 | value |
| 667 | value_from_register (type, regnum, frame) |
| 668 | struct type *type; |
| 669 | int regnum; |
| 670 | FRAME frame; |
| 671 | { |
| 672 | char raw_buffer [MAX_REGISTER_RAW_SIZE]; |
| 673 | char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE]; |
| 674 | CORE_ADDR addr; |
| 675 | int optim; |
| 676 | value v = allocate_value (type); |
| 677 | int len = TYPE_LENGTH (type); |
| 678 | char *value_bytes = 0; |
| 679 | int value_bytes_copied = 0; |
| 680 | int num_storage_locs; |
| 681 | enum lval_type lval; |
| 682 | |
| 683 | VALUE_REGNO (v) = regnum; |
| 684 | |
| 685 | num_storage_locs = (len > REGISTER_VIRTUAL_SIZE (regnum) ? |
| 686 | ((len - 1) / REGISTER_RAW_SIZE (regnum)) + 1 : |
| 687 | 1); |
| 688 | |
| 689 | if (num_storage_locs > 1 |
| 690 | #ifdef GDB_TARGET_IS_H8500 |
| 691 | || TYPE_CODE (type) == TYPE_CODE_PTR |
| 692 | #endif |
| 693 | ) |
| 694 | { |
| 695 | /* Value spread across multiple storage locations. */ |
| 696 | |
| 697 | int local_regnum; |
| 698 | int mem_stor = 0, reg_stor = 0; |
| 699 | int mem_tracking = 1; |
| 700 | CORE_ADDR last_addr = 0; |
| 701 | CORE_ADDR first_addr = 0; |
| 702 | |
| 703 | value_bytes = (char *) alloca (len + MAX_REGISTER_RAW_SIZE); |
| 704 | |
| 705 | /* Copy all of the data out, whereever it may be. */ |
| 706 | |
| 707 | #ifdef GDB_TARGET_IS_H8500 |
| 708 | /* This piece of hideosity is required because the H8500 treats registers |
| 709 | differently depending upon whether they are used as pointers or not. As a |
| 710 | pointer, a register needs to have a page register tacked onto the front. |
| 711 | An alternate way to do this would be to have gcc output different register |
| 712 | numbers for the pointer & non-pointer form of the register. But, it |
| 713 | doesn't, so we're stuck with this. */ |
| 714 | |
| 715 | if (TYPE_CODE (type) == TYPE_CODE_PTR |
| 716 | && len > 2) |
| 717 | { |
| 718 | int page_regnum; |
| 719 | |
| 720 | switch (regnum) |
| 721 | { |
| 722 | case R0_REGNUM: case R1_REGNUM: case R2_REGNUM: case R3_REGNUM: |
| 723 | page_regnum = SEG_D_REGNUM; |
| 724 | break; |
| 725 | case R4_REGNUM: case R5_REGNUM: |
| 726 | page_regnum = SEG_E_REGNUM; |
| 727 | break; |
| 728 | case R6_REGNUM: case R7_REGNUM: |
| 729 | page_regnum = SEG_T_REGNUM; |
| 730 | break; |
| 731 | } |
| 732 | |
| 733 | value_bytes[0] = 0; |
| 734 | get_saved_register (value_bytes + 1, |
| 735 | &optim, |
| 736 | &addr, |
| 737 | frame, |
| 738 | page_regnum, |
| 739 | &lval); |
| 740 | |
| 741 | if (lval == lval_register) |
| 742 | reg_stor++; |
| 743 | else |
| 744 | mem_stor++; |
| 745 | first_addr = addr; |
| 746 | last_addr = addr; |
| 747 | |
| 748 | get_saved_register (value_bytes + 2, |
| 749 | &optim, |
| 750 | &addr, |
| 751 | frame, |
| 752 | regnum, |
| 753 | &lval); |
| 754 | |
| 755 | if (lval == lval_register) |
| 756 | reg_stor++; |
| 757 | else |
| 758 | { |
| 759 | mem_stor++; |
| 760 | mem_tracking = mem_tracking && (addr == last_addr); |
| 761 | } |
| 762 | last_addr = addr; |
| 763 | } |
| 764 | else |
| 765 | #endif /* GDB_TARGET_IS_H8500 */ |
| 766 | for (local_regnum = regnum; |
| 767 | value_bytes_copied < len; |
| 768 | (value_bytes_copied += REGISTER_RAW_SIZE (local_regnum), |
| 769 | ++local_regnum)) |
| 770 | { |
| 771 | get_saved_register (value_bytes + value_bytes_copied, |
| 772 | &optim, |
| 773 | &addr, |
| 774 | frame, |
| 775 | local_regnum, |
| 776 | &lval); |
| 777 | |
| 778 | if (regnum == local_regnum) |
| 779 | first_addr = addr; |
| 780 | if (lval == lval_register) |
| 781 | reg_stor++; |
| 782 | else |
| 783 | { |
| 784 | mem_stor++; |
| 785 | |
| 786 | mem_tracking = |
| 787 | (mem_tracking |
| 788 | && (regnum == local_regnum |
| 789 | || addr == last_addr)); |
| 790 | } |
| 791 | last_addr = addr; |
| 792 | } |
| 793 | |
| 794 | if ((reg_stor && mem_stor) |
| 795 | || (mem_stor && !mem_tracking)) |
| 796 | /* Mixed storage; all of the hassle we just went through was |
| 797 | for some good purpose. */ |
| 798 | { |
| 799 | VALUE_LVAL (v) = lval_reg_frame_relative; |
| 800 | VALUE_FRAME (v) = FRAME_FP (frame); |
| 801 | VALUE_FRAME_REGNUM (v) = regnum; |
| 802 | } |
| 803 | else if (mem_stor) |
| 804 | { |
| 805 | VALUE_LVAL (v) = lval_memory; |
| 806 | VALUE_ADDRESS (v) = first_addr; |
| 807 | } |
| 808 | else if (reg_stor) |
| 809 | { |
| 810 | VALUE_LVAL (v) = lval_register; |
| 811 | VALUE_ADDRESS (v) = first_addr; |
| 812 | } |
| 813 | else |
| 814 | fatal ("value_from_register: Value not stored anywhere!"); |
| 815 | |
| 816 | VALUE_OPTIMIZED_OUT (v) = optim; |
| 817 | |
| 818 | /* Any structure stored in more than one register will always be |
| 819 | an integral number of registers. Otherwise, you'd need to do |
| 820 | some fiddling with the last register copied here for little |
| 821 | endian machines. */ |
| 822 | |
| 823 | /* Copy into the contents section of the value. */ |
| 824 | memcpy (VALUE_CONTENTS_RAW (v), value_bytes, len); |
| 825 | |
| 826 | /* Finally do any conversion necessary when extracting this |
| 827 | type from more than one register. */ |
| 828 | #ifdef REGISTER_CONVERT_TO_TYPE |
| 829 | REGISTER_CONVERT_TO_TYPE(regnum, type, VALUE_CONTENTS_RAW(v)); |
| 830 | #endif |
| 831 | return v; |
| 832 | } |
| 833 | |
| 834 | /* Data is completely contained within a single register. Locate the |
| 835 | register's contents in a real register or in core; |
| 836 | read the data in raw format. */ |
| 837 | |
| 838 | get_saved_register (raw_buffer, &optim, &addr, frame, regnum, &lval); |
| 839 | VALUE_OPTIMIZED_OUT (v) = optim; |
| 840 | VALUE_LVAL (v) = lval; |
| 841 | VALUE_ADDRESS (v) = addr; |
| 842 | |
| 843 | /* Convert the raw contents to virtual contents. |
| 844 | (Just copy them if the formats are the same.) */ |
| 845 | |
| 846 | REGISTER_CONVERT_TO_VIRTUAL (regnum, raw_buffer, virtual_buffer); |
| 847 | |
| 848 | if (REGISTER_CONVERTIBLE (regnum)) |
| 849 | { |
| 850 | /* When the raw and virtual formats differ, the virtual format |
| 851 | corresponds to a specific data type. If we want that type, |
| 852 | copy the data into the value. |
| 853 | Otherwise, do a type-conversion. */ |
| 854 | |
| 855 | if (type != REGISTER_VIRTUAL_TYPE (regnum)) |
| 856 | { |
| 857 | /* eg a variable of type `float' in a 68881 register |
| 858 | with raw type `extended' and virtual type `double'. |
| 859 | Fetch it as a `double' and then convert to `float'. */ |
| 860 | v = allocate_value (REGISTER_VIRTUAL_TYPE (regnum)); |
| 861 | memcpy (VALUE_CONTENTS_RAW (v), virtual_buffer, len); |
| 862 | v = value_cast (type, v); |
| 863 | } |
| 864 | else |
| 865 | memcpy (VALUE_CONTENTS_RAW (v), virtual_buffer, len); |
| 866 | } |
| 867 | else |
| 868 | { |
| 869 | /* Raw and virtual formats are the same for this register. */ |
| 870 | |
| 871 | #if TARGET_BYTE_ORDER == BIG_ENDIAN |
| 872 | if (len < REGISTER_RAW_SIZE (regnum)) |
| 873 | { |
| 874 | /* Big-endian, and we want less than full size. */ |
| 875 | VALUE_OFFSET (v) = REGISTER_RAW_SIZE (regnum) - len; |
| 876 | } |
| 877 | #endif |
| 878 | |
| 879 | memcpy (VALUE_CONTENTS_RAW (v), virtual_buffer + VALUE_OFFSET (v), len); |
| 880 | } |
| 881 | |
| 882 | return v; |
| 883 | } |
| 884 | \f |
| 885 | /* Given a struct symbol for a variable or function, |
| 886 | and a stack frame id, |
| 887 | return a (pointer to a) struct value containing the properly typed |
| 888 | address. */ |
| 889 | |
| 890 | value |
| 891 | locate_var_value (var, frame) |
| 892 | register struct symbol *var; |
| 893 | FRAME frame; |
| 894 | { |
| 895 | CORE_ADDR addr = 0; |
| 896 | struct type *type = SYMBOL_TYPE (var); |
| 897 | value lazy_value; |
| 898 | |
| 899 | /* Evaluate it first; if the result is a memory address, we're fine. |
| 900 | Lazy evaluation pays off here. */ |
| 901 | |
| 902 | lazy_value = read_var_value (var, frame); |
| 903 | if (lazy_value == 0) |
| 904 | error ("Address of \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var)); |
| 905 | |
| 906 | if (VALUE_LAZY (lazy_value) |
| 907 | || TYPE_CODE (type) == TYPE_CODE_FUNC) |
| 908 | { |
| 909 | addr = VALUE_ADDRESS (lazy_value); |
| 910 | return value_from_longest (lookup_pointer_type (type), (LONGEST) addr); |
| 911 | } |
| 912 | |
| 913 | /* Not a memory address; check what the problem was. */ |
| 914 | switch (VALUE_LVAL (lazy_value)) |
| 915 | { |
| 916 | case lval_register: |
| 917 | case lval_reg_frame_relative: |
| 918 | error ("Address requested for identifier \"%s\" which is in a register.", |
| 919 | SYMBOL_SOURCE_NAME (var)); |
| 920 | break; |
| 921 | |
| 922 | default: |
| 923 | error ("Can't take address of \"%s\" which isn't an lvalue.", |
| 924 | SYMBOL_SOURCE_NAME (var)); |
| 925 | break; |
| 926 | } |
| 927 | return 0; /* For lint -- never reached */ |
| 928 | } |