| 1 | /* Agent expression code for remote server. |
| 2 | Copyright (C) 2009-2012 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "server.h" |
| 20 | #include "ax.h" |
| 21 | |
| 22 | static void ax_vdebug (const char *, ...) ATTR_FORMAT (printf, 1, 2); |
| 23 | |
| 24 | #ifdef IN_PROCESS_AGENT |
| 25 | int debug_agent = 0; |
| 26 | #endif |
| 27 | |
| 28 | static void |
| 29 | ax_vdebug (const char *fmt, ...) |
| 30 | { |
| 31 | char buf[1024]; |
| 32 | va_list ap; |
| 33 | |
| 34 | va_start (ap, fmt); |
| 35 | vsprintf (buf, fmt, ap); |
| 36 | fprintf (stderr, PROG "/ax: %s\n", buf); |
| 37 | va_end (ap); |
| 38 | } |
| 39 | |
| 40 | #define ax_debug_1(level, fmt, args...) \ |
| 41 | do { \ |
| 42 | if (level <= debug_threads) \ |
| 43 | ax_vdebug ((fmt), ##args); \ |
| 44 | } while (0) |
| 45 | |
| 46 | #define ax_debug(FMT, args...) \ |
| 47 | ax_debug_1 (1, FMT, ##args) |
| 48 | |
| 49 | /* This enum must exactly match what is documented in |
| 50 | gdb/doc/agentexpr.texi, including all the numerical values. */ |
| 51 | |
| 52 | enum gdb_agent_op |
| 53 | { |
| 54 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \ |
| 55 | gdb_agent_op_ ## NAME = VALUE, |
| 56 | #include "ax.def" |
| 57 | #undef DEFOP |
| 58 | gdb_agent_op_last |
| 59 | }; |
| 60 | |
| 61 | static const char *gdb_agent_op_names [gdb_agent_op_last] = |
| 62 | { |
| 63 | "?undef?" |
| 64 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) , # NAME |
| 65 | #include "ax.def" |
| 66 | #undef DEFOP |
| 67 | }; |
| 68 | |
| 69 | static const unsigned char gdb_agent_op_sizes [gdb_agent_op_last] = |
| 70 | { |
| 71 | 0 |
| 72 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) , SIZE |
| 73 | #include "ax.def" |
| 74 | #undef DEFOP |
| 75 | }; |
| 76 | |
| 77 | /* A wrapper for gdb_agent_op_names that does some bounds-checking. */ |
| 78 | |
| 79 | static const char * |
| 80 | gdb_agent_op_name (int op) |
| 81 | { |
| 82 | if (op < 0 || op >= gdb_agent_op_last || gdb_agent_op_names[op] == NULL) |
| 83 | return "?undef?"; |
| 84 | return gdb_agent_op_names[op]; |
| 85 | } |
| 86 | |
| 87 | #ifndef IN_PROCESS_AGENT |
| 88 | |
| 89 | /* The packet form of an agent expression consists of an 'X', number |
| 90 | of bytes in expression, a comma, and then the bytes. */ |
| 91 | |
| 92 | struct agent_expr * |
| 93 | gdb_parse_agent_expr (char **actparm) |
| 94 | { |
| 95 | char *act = *actparm; |
| 96 | ULONGEST xlen; |
| 97 | struct agent_expr *aexpr; |
| 98 | |
| 99 | ++act; /* skip the X */ |
| 100 | act = unpack_varlen_hex (act, &xlen); |
| 101 | ++act; /* skip a comma */ |
| 102 | aexpr = xmalloc (sizeof (struct agent_expr)); |
| 103 | aexpr->length = xlen; |
| 104 | aexpr->bytes = xmalloc (xlen); |
| 105 | convert_ascii_to_int (act, aexpr->bytes, xlen); |
| 106 | *actparm = act + (xlen * 2); |
| 107 | return aexpr; |
| 108 | } |
| 109 | |
| 110 | /* Convert the bytes of an agent expression back into hex digits, so |
| 111 | they can be printed or uploaded. This allocates the buffer, |
| 112 | callers should free when they are done with it. */ |
| 113 | |
| 114 | char * |
| 115 | gdb_unparse_agent_expr (struct agent_expr *aexpr) |
| 116 | { |
| 117 | char *rslt; |
| 118 | |
| 119 | rslt = xmalloc (2 * aexpr->length + 1); |
| 120 | convert_int_to_ascii (aexpr->bytes, rslt, aexpr->length); |
| 121 | return rslt; |
| 122 | } |
| 123 | |
| 124 | /* Bytecode compilation. */ |
| 125 | |
| 126 | CORE_ADDR current_insn_ptr; |
| 127 | |
| 128 | int emit_error; |
| 129 | |
| 130 | struct bytecode_address |
| 131 | { |
| 132 | int pc; |
| 133 | CORE_ADDR address; |
| 134 | int goto_pc; |
| 135 | /* Offset and size of field to be modified in the goto block. */ |
| 136 | int from_offset, from_size; |
| 137 | struct bytecode_address *next; |
| 138 | } *bytecode_address_table; |
| 139 | |
| 140 | void |
| 141 | emit_prologue (void) |
| 142 | { |
| 143 | target_emit_ops ()->emit_prologue (); |
| 144 | } |
| 145 | |
| 146 | void |
| 147 | emit_epilogue (void) |
| 148 | { |
| 149 | target_emit_ops ()->emit_epilogue (); |
| 150 | } |
| 151 | |
| 152 | static void |
| 153 | emit_add (void) |
| 154 | { |
| 155 | target_emit_ops ()->emit_add (); |
| 156 | } |
| 157 | |
| 158 | static void |
| 159 | emit_sub (void) |
| 160 | { |
| 161 | target_emit_ops ()->emit_sub (); |
| 162 | } |
| 163 | |
| 164 | static void |
| 165 | emit_mul (void) |
| 166 | { |
| 167 | target_emit_ops ()->emit_mul (); |
| 168 | } |
| 169 | |
| 170 | static void |
| 171 | emit_lsh (void) |
| 172 | { |
| 173 | target_emit_ops ()->emit_lsh (); |
| 174 | } |
| 175 | |
| 176 | static void |
| 177 | emit_rsh_signed (void) |
| 178 | { |
| 179 | target_emit_ops ()->emit_rsh_signed (); |
| 180 | } |
| 181 | |
| 182 | static void |
| 183 | emit_rsh_unsigned (void) |
| 184 | { |
| 185 | target_emit_ops ()->emit_rsh_unsigned (); |
| 186 | } |
| 187 | |
| 188 | static void |
| 189 | emit_ext (int arg) |
| 190 | { |
| 191 | target_emit_ops ()->emit_ext (arg); |
| 192 | } |
| 193 | |
| 194 | static void |
| 195 | emit_log_not (void) |
| 196 | { |
| 197 | target_emit_ops ()->emit_log_not (); |
| 198 | } |
| 199 | |
| 200 | static void |
| 201 | emit_bit_and (void) |
| 202 | { |
| 203 | target_emit_ops ()->emit_bit_and (); |
| 204 | } |
| 205 | |
| 206 | static void |
| 207 | emit_bit_or (void) |
| 208 | { |
| 209 | target_emit_ops ()->emit_bit_or (); |
| 210 | } |
| 211 | |
| 212 | static void |
| 213 | emit_bit_xor (void) |
| 214 | { |
| 215 | target_emit_ops ()->emit_bit_xor (); |
| 216 | } |
| 217 | |
| 218 | static void |
| 219 | emit_bit_not (void) |
| 220 | { |
| 221 | target_emit_ops ()->emit_bit_not (); |
| 222 | } |
| 223 | |
| 224 | static void |
| 225 | emit_equal (void) |
| 226 | { |
| 227 | target_emit_ops ()->emit_equal (); |
| 228 | } |
| 229 | |
| 230 | static void |
| 231 | emit_less_signed (void) |
| 232 | { |
| 233 | target_emit_ops ()->emit_less_signed (); |
| 234 | } |
| 235 | |
| 236 | static void |
| 237 | emit_less_unsigned (void) |
| 238 | { |
| 239 | target_emit_ops ()->emit_less_unsigned (); |
| 240 | } |
| 241 | |
| 242 | static void |
| 243 | emit_ref (int size) |
| 244 | { |
| 245 | target_emit_ops ()->emit_ref (size); |
| 246 | } |
| 247 | |
| 248 | static void |
| 249 | emit_if_goto (int *offset_p, int *size_p) |
| 250 | { |
| 251 | target_emit_ops ()->emit_if_goto (offset_p, size_p); |
| 252 | } |
| 253 | |
| 254 | static void |
| 255 | emit_goto (int *offset_p, int *size_p) |
| 256 | { |
| 257 | target_emit_ops ()->emit_goto (offset_p, size_p); |
| 258 | } |
| 259 | |
| 260 | static void |
| 261 | write_goto_address (CORE_ADDR from, CORE_ADDR to, int size) |
| 262 | { |
| 263 | target_emit_ops ()->write_goto_address (from, to, size); |
| 264 | } |
| 265 | |
| 266 | static void |
| 267 | emit_const (LONGEST num) |
| 268 | { |
| 269 | target_emit_ops ()->emit_const (num); |
| 270 | } |
| 271 | |
| 272 | static void |
| 273 | emit_reg (int reg) |
| 274 | { |
| 275 | target_emit_ops ()->emit_reg (reg); |
| 276 | } |
| 277 | |
| 278 | static void |
| 279 | emit_pop (void) |
| 280 | { |
| 281 | target_emit_ops ()->emit_pop (); |
| 282 | } |
| 283 | |
| 284 | static void |
| 285 | emit_stack_flush (void) |
| 286 | { |
| 287 | target_emit_ops ()->emit_stack_flush (); |
| 288 | } |
| 289 | |
| 290 | static void |
| 291 | emit_zero_ext (int arg) |
| 292 | { |
| 293 | target_emit_ops ()->emit_zero_ext (arg); |
| 294 | } |
| 295 | |
| 296 | static void |
| 297 | emit_swap (void) |
| 298 | { |
| 299 | target_emit_ops ()->emit_swap (); |
| 300 | } |
| 301 | |
| 302 | static void |
| 303 | emit_stack_adjust (int n) |
| 304 | { |
| 305 | target_emit_ops ()->emit_stack_adjust (n); |
| 306 | } |
| 307 | |
| 308 | /* FN's prototype is `LONGEST(*fn)(int)'. */ |
| 309 | |
| 310 | static void |
| 311 | emit_int_call_1 (CORE_ADDR fn, int arg1) |
| 312 | { |
| 313 | target_emit_ops ()->emit_int_call_1 (fn, arg1); |
| 314 | } |
| 315 | |
| 316 | /* FN's prototype is `void(*fn)(int,LONGEST)'. */ |
| 317 | |
| 318 | static void |
| 319 | emit_void_call_2 (CORE_ADDR fn, int arg1) |
| 320 | { |
| 321 | target_emit_ops ()->emit_void_call_2 (fn, arg1); |
| 322 | } |
| 323 | |
| 324 | static void |
| 325 | emit_eq_goto (int *offset_p, int *size_p) |
| 326 | { |
| 327 | target_emit_ops ()->emit_eq_goto (offset_p, size_p); |
| 328 | } |
| 329 | |
| 330 | static void |
| 331 | emit_ne_goto (int *offset_p, int *size_p) |
| 332 | { |
| 333 | target_emit_ops ()->emit_ne_goto (offset_p, size_p); |
| 334 | } |
| 335 | |
| 336 | static void |
| 337 | emit_lt_goto (int *offset_p, int *size_p) |
| 338 | { |
| 339 | target_emit_ops ()->emit_lt_goto (offset_p, size_p); |
| 340 | } |
| 341 | |
| 342 | static void |
| 343 | emit_ge_goto (int *offset_p, int *size_p) |
| 344 | { |
| 345 | target_emit_ops ()->emit_ge_goto (offset_p, size_p); |
| 346 | } |
| 347 | |
| 348 | static void |
| 349 | emit_gt_goto (int *offset_p, int *size_p) |
| 350 | { |
| 351 | target_emit_ops ()->emit_gt_goto (offset_p, size_p); |
| 352 | } |
| 353 | |
| 354 | static void |
| 355 | emit_le_goto (int *offset_p, int *size_p) |
| 356 | { |
| 357 | target_emit_ops ()->emit_le_goto (offset_p, size_p); |
| 358 | } |
| 359 | |
| 360 | /* Scan an agent expression for any evidence that the given PC is the |
| 361 | target of a jump bytecode in the expression. */ |
| 362 | |
| 363 | int |
| 364 | is_goto_target (struct agent_expr *aexpr, int pc) |
| 365 | { |
| 366 | int i; |
| 367 | unsigned char op; |
| 368 | |
| 369 | for (i = 0; i < aexpr->length; i += 1 + gdb_agent_op_sizes[op]) |
| 370 | { |
| 371 | op = aexpr->bytes[i]; |
| 372 | |
| 373 | if (op == gdb_agent_op_goto || op == gdb_agent_op_if_goto) |
| 374 | { |
| 375 | int target = (aexpr->bytes[i + 1] << 8) + aexpr->bytes[i + 2]; |
| 376 | if (target == pc) |
| 377 | return 1; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | return 0; |
| 382 | } |
| 383 | |
| 384 | /* Given an agent expression, turn it into native code. */ |
| 385 | |
| 386 | enum eval_result_type |
| 387 | compile_bytecodes (struct agent_expr *aexpr) |
| 388 | { |
| 389 | int pc = 0; |
| 390 | int done = 0; |
| 391 | unsigned char op, next_op; |
| 392 | int arg; |
| 393 | /* This is only used to build 64-bit value for constants. */ |
| 394 | ULONGEST top; |
| 395 | struct bytecode_address *aentry, *aentry2; |
| 396 | |
| 397 | #define UNHANDLED \ |
| 398 | do \ |
| 399 | { \ |
| 400 | ax_debug ("Cannot compile op 0x%x\n", op); \ |
| 401 | return expr_eval_unhandled_opcode; \ |
| 402 | } while (0) |
| 403 | |
| 404 | if (aexpr->length == 0) |
| 405 | { |
| 406 | ax_debug ("empty agent expression\n"); |
| 407 | return expr_eval_empty_expression; |
| 408 | } |
| 409 | |
| 410 | bytecode_address_table = NULL; |
| 411 | |
| 412 | while (!done) |
| 413 | { |
| 414 | op = aexpr->bytes[pc]; |
| 415 | |
| 416 | ax_debug ("About to compile op 0x%x, pc=%d\n", op, pc); |
| 417 | |
| 418 | /* Record the compiled-code address of the bytecode, for use by |
| 419 | jump instructions. */ |
| 420 | aentry = xmalloc (sizeof (struct bytecode_address)); |
| 421 | aentry->pc = pc; |
| 422 | aentry->address = current_insn_ptr; |
| 423 | aentry->goto_pc = -1; |
| 424 | aentry->from_offset = aentry->from_size = 0; |
| 425 | aentry->next = bytecode_address_table; |
| 426 | bytecode_address_table = aentry; |
| 427 | |
| 428 | ++pc; |
| 429 | |
| 430 | emit_error = 0; |
| 431 | |
| 432 | switch (op) |
| 433 | { |
| 434 | case gdb_agent_op_add: |
| 435 | emit_add (); |
| 436 | break; |
| 437 | |
| 438 | case gdb_agent_op_sub: |
| 439 | emit_sub (); |
| 440 | break; |
| 441 | |
| 442 | case gdb_agent_op_mul: |
| 443 | emit_mul (); |
| 444 | break; |
| 445 | |
| 446 | case gdb_agent_op_div_signed: |
| 447 | UNHANDLED; |
| 448 | break; |
| 449 | |
| 450 | case gdb_agent_op_div_unsigned: |
| 451 | UNHANDLED; |
| 452 | break; |
| 453 | |
| 454 | case gdb_agent_op_rem_signed: |
| 455 | UNHANDLED; |
| 456 | break; |
| 457 | |
| 458 | case gdb_agent_op_rem_unsigned: |
| 459 | UNHANDLED; |
| 460 | break; |
| 461 | |
| 462 | case gdb_agent_op_lsh: |
| 463 | emit_lsh (); |
| 464 | break; |
| 465 | |
| 466 | case gdb_agent_op_rsh_signed: |
| 467 | emit_rsh_signed (); |
| 468 | break; |
| 469 | |
| 470 | case gdb_agent_op_rsh_unsigned: |
| 471 | emit_rsh_unsigned (); |
| 472 | break; |
| 473 | |
| 474 | case gdb_agent_op_trace: |
| 475 | UNHANDLED; |
| 476 | break; |
| 477 | |
| 478 | case gdb_agent_op_trace_quick: |
| 479 | UNHANDLED; |
| 480 | break; |
| 481 | |
| 482 | case gdb_agent_op_log_not: |
| 483 | emit_log_not (); |
| 484 | break; |
| 485 | |
| 486 | case gdb_agent_op_bit_and: |
| 487 | emit_bit_and (); |
| 488 | break; |
| 489 | |
| 490 | case gdb_agent_op_bit_or: |
| 491 | emit_bit_or (); |
| 492 | break; |
| 493 | |
| 494 | case gdb_agent_op_bit_xor: |
| 495 | emit_bit_xor (); |
| 496 | break; |
| 497 | |
| 498 | case gdb_agent_op_bit_not: |
| 499 | emit_bit_not (); |
| 500 | break; |
| 501 | |
| 502 | case gdb_agent_op_equal: |
| 503 | next_op = aexpr->bytes[pc]; |
| 504 | if (next_op == gdb_agent_op_if_goto |
| 505 | && !is_goto_target (aexpr, pc) |
| 506 | && target_emit_ops ()->emit_eq_goto) |
| 507 | { |
| 508 | ax_debug ("Combining equal & if_goto"); |
| 509 | pc += 1; |
| 510 | aentry->pc = pc; |
| 511 | arg = aexpr->bytes[pc++]; |
| 512 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 513 | aentry->goto_pc = arg; |
| 514 | emit_eq_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 515 | } |
| 516 | else if (next_op == gdb_agent_op_log_not |
| 517 | && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto) |
| 518 | && !is_goto_target (aexpr, pc + 1) |
| 519 | && target_emit_ops ()->emit_ne_goto) |
| 520 | { |
| 521 | ax_debug ("Combining equal & log_not & if_goto"); |
| 522 | pc += 2; |
| 523 | aentry->pc = pc; |
| 524 | arg = aexpr->bytes[pc++]; |
| 525 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 526 | aentry->goto_pc = arg; |
| 527 | emit_ne_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 528 | } |
| 529 | else |
| 530 | emit_equal (); |
| 531 | break; |
| 532 | |
| 533 | case gdb_agent_op_less_signed: |
| 534 | next_op = aexpr->bytes[pc]; |
| 535 | if (next_op == gdb_agent_op_if_goto |
| 536 | && !is_goto_target (aexpr, pc)) |
| 537 | { |
| 538 | ax_debug ("Combining less_signed & if_goto"); |
| 539 | pc += 1; |
| 540 | aentry->pc = pc; |
| 541 | arg = aexpr->bytes[pc++]; |
| 542 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 543 | aentry->goto_pc = arg; |
| 544 | emit_lt_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 545 | } |
| 546 | else if (next_op == gdb_agent_op_log_not |
| 547 | && !is_goto_target (aexpr, pc) |
| 548 | && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto) |
| 549 | && !is_goto_target (aexpr, pc + 1)) |
| 550 | { |
| 551 | ax_debug ("Combining less_signed & log_not & if_goto"); |
| 552 | pc += 2; |
| 553 | aentry->pc = pc; |
| 554 | arg = aexpr->bytes[pc++]; |
| 555 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 556 | aentry->goto_pc = arg; |
| 557 | emit_ge_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 558 | } |
| 559 | else |
| 560 | emit_less_signed (); |
| 561 | break; |
| 562 | |
| 563 | case gdb_agent_op_less_unsigned: |
| 564 | emit_less_unsigned (); |
| 565 | break; |
| 566 | |
| 567 | case gdb_agent_op_ext: |
| 568 | arg = aexpr->bytes[pc++]; |
| 569 | if (arg < (sizeof (LONGEST) * 8)) |
| 570 | emit_ext (arg); |
| 571 | break; |
| 572 | |
| 573 | case gdb_agent_op_ref8: |
| 574 | emit_ref (1); |
| 575 | break; |
| 576 | |
| 577 | case gdb_agent_op_ref16: |
| 578 | emit_ref (2); |
| 579 | break; |
| 580 | |
| 581 | case gdb_agent_op_ref32: |
| 582 | emit_ref (4); |
| 583 | break; |
| 584 | |
| 585 | case gdb_agent_op_ref64: |
| 586 | emit_ref (8); |
| 587 | break; |
| 588 | |
| 589 | case gdb_agent_op_if_goto: |
| 590 | arg = aexpr->bytes[pc++]; |
| 591 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 592 | aentry->goto_pc = arg; |
| 593 | emit_if_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 594 | break; |
| 595 | |
| 596 | case gdb_agent_op_goto: |
| 597 | arg = aexpr->bytes[pc++]; |
| 598 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 599 | aentry->goto_pc = arg; |
| 600 | emit_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 601 | break; |
| 602 | |
| 603 | case gdb_agent_op_const8: |
| 604 | emit_stack_flush (); |
| 605 | top = aexpr->bytes[pc++]; |
| 606 | emit_const (top); |
| 607 | break; |
| 608 | |
| 609 | case gdb_agent_op_const16: |
| 610 | emit_stack_flush (); |
| 611 | top = aexpr->bytes[pc++]; |
| 612 | top = (top << 8) + aexpr->bytes[pc++]; |
| 613 | emit_const (top); |
| 614 | break; |
| 615 | |
| 616 | case gdb_agent_op_const32: |
| 617 | emit_stack_flush (); |
| 618 | top = aexpr->bytes[pc++]; |
| 619 | top = (top << 8) + aexpr->bytes[pc++]; |
| 620 | top = (top << 8) + aexpr->bytes[pc++]; |
| 621 | top = (top << 8) + aexpr->bytes[pc++]; |
| 622 | emit_const (top); |
| 623 | break; |
| 624 | |
| 625 | case gdb_agent_op_const64: |
| 626 | emit_stack_flush (); |
| 627 | top = aexpr->bytes[pc++]; |
| 628 | top = (top << 8) + aexpr->bytes[pc++]; |
| 629 | top = (top << 8) + aexpr->bytes[pc++]; |
| 630 | top = (top << 8) + aexpr->bytes[pc++]; |
| 631 | top = (top << 8) + aexpr->bytes[pc++]; |
| 632 | top = (top << 8) + aexpr->bytes[pc++]; |
| 633 | top = (top << 8) + aexpr->bytes[pc++]; |
| 634 | top = (top << 8) + aexpr->bytes[pc++]; |
| 635 | emit_const (top); |
| 636 | break; |
| 637 | |
| 638 | case gdb_agent_op_reg: |
| 639 | emit_stack_flush (); |
| 640 | arg = aexpr->bytes[pc++]; |
| 641 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 642 | emit_reg (arg); |
| 643 | break; |
| 644 | |
| 645 | case gdb_agent_op_end: |
| 646 | ax_debug ("At end of expression\n"); |
| 647 | |
| 648 | /* Assume there is one stack element left, and that it is |
| 649 | cached in "top" where emit_epilogue can get to it. */ |
| 650 | emit_stack_adjust (1); |
| 651 | |
| 652 | done = 1; |
| 653 | break; |
| 654 | |
| 655 | case gdb_agent_op_dup: |
| 656 | /* In our design, dup is equivalent to stack flushing. */ |
| 657 | emit_stack_flush (); |
| 658 | break; |
| 659 | |
| 660 | case gdb_agent_op_pop: |
| 661 | emit_pop (); |
| 662 | break; |
| 663 | |
| 664 | case gdb_agent_op_zero_ext: |
| 665 | arg = aexpr->bytes[pc++]; |
| 666 | if (arg < (sizeof (LONGEST) * 8)) |
| 667 | emit_zero_ext (arg); |
| 668 | break; |
| 669 | |
| 670 | case gdb_agent_op_swap: |
| 671 | next_op = aexpr->bytes[pc]; |
| 672 | /* Detect greater-than comparison sequences. */ |
| 673 | if (next_op == gdb_agent_op_less_signed |
| 674 | && !is_goto_target (aexpr, pc) |
| 675 | && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto) |
| 676 | && !is_goto_target (aexpr, pc + 1)) |
| 677 | { |
| 678 | ax_debug ("Combining swap & less_signed & if_goto"); |
| 679 | pc += 2; |
| 680 | aentry->pc = pc; |
| 681 | arg = aexpr->bytes[pc++]; |
| 682 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 683 | aentry->goto_pc = arg; |
| 684 | emit_gt_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 685 | } |
| 686 | else if (next_op == gdb_agent_op_less_signed |
| 687 | && !is_goto_target (aexpr, pc) |
| 688 | && (aexpr->bytes[pc + 1] == gdb_agent_op_log_not) |
| 689 | && !is_goto_target (aexpr, pc + 1) |
| 690 | && (aexpr->bytes[pc + 2] == gdb_agent_op_if_goto) |
| 691 | && !is_goto_target (aexpr, pc + 2)) |
| 692 | { |
| 693 | ax_debug ("Combining swap & less_signed & log_not & if_goto"); |
| 694 | pc += 3; |
| 695 | aentry->pc = pc; |
| 696 | arg = aexpr->bytes[pc++]; |
| 697 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 698 | aentry->goto_pc = arg; |
| 699 | emit_le_goto (&(aentry->from_offset), &(aentry->from_size)); |
| 700 | } |
| 701 | else |
| 702 | emit_swap (); |
| 703 | break; |
| 704 | |
| 705 | case gdb_agent_op_getv: |
| 706 | emit_stack_flush (); |
| 707 | arg = aexpr->bytes[pc++]; |
| 708 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 709 | emit_int_call_1 (get_get_tsv_func_addr (), |
| 710 | arg); |
| 711 | break; |
| 712 | |
| 713 | case gdb_agent_op_setv: |
| 714 | arg = aexpr->bytes[pc++]; |
| 715 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 716 | emit_void_call_2 (get_set_tsv_func_addr (), |
| 717 | arg); |
| 718 | break; |
| 719 | |
| 720 | case gdb_agent_op_tracev: |
| 721 | UNHANDLED; |
| 722 | break; |
| 723 | |
| 724 | /* GDB never (currently) generates any of these ops. */ |
| 725 | case gdb_agent_op_float: |
| 726 | case gdb_agent_op_ref_float: |
| 727 | case gdb_agent_op_ref_double: |
| 728 | case gdb_agent_op_ref_long_double: |
| 729 | case gdb_agent_op_l_to_d: |
| 730 | case gdb_agent_op_d_to_l: |
| 731 | case gdb_agent_op_trace16: |
| 732 | UNHANDLED; |
| 733 | break; |
| 734 | |
| 735 | default: |
| 736 | ax_debug ("Agent expression op 0x%x not recognized\n", op); |
| 737 | /* Don't struggle on, things will just get worse. */ |
| 738 | return expr_eval_unrecognized_opcode; |
| 739 | } |
| 740 | |
| 741 | /* This catches errors that occur in target-specific code |
| 742 | emission. */ |
| 743 | if (emit_error) |
| 744 | { |
| 745 | ax_debug ("Error %d while emitting code for %s\n", |
| 746 | emit_error, gdb_agent_op_name (op)); |
| 747 | return expr_eval_unhandled_opcode; |
| 748 | } |
| 749 | |
| 750 | ax_debug ("Op %s compiled\n", gdb_agent_op_name (op)); |
| 751 | } |
| 752 | |
| 753 | /* Now fill in real addresses as goto destinations. */ |
| 754 | for (aentry = bytecode_address_table; aentry; aentry = aentry->next) |
| 755 | { |
| 756 | int written = 0; |
| 757 | |
| 758 | if (aentry->goto_pc < 0) |
| 759 | continue; |
| 760 | |
| 761 | /* Find the location that we are going to, and call back into |
| 762 | target-specific code to write the actual address or |
| 763 | displacement. */ |
| 764 | for (aentry2 = bytecode_address_table; aentry2; aentry2 = aentry2->next) |
| 765 | { |
| 766 | if (aentry2->pc == aentry->goto_pc) |
| 767 | { |
| 768 | ax_debug ("Want to jump from %s to %s\n", |
| 769 | paddress (aentry->address), |
| 770 | paddress (aentry2->address)); |
| 771 | write_goto_address (aentry->address + aentry->from_offset, |
| 772 | aentry2->address, aentry->from_size); |
| 773 | written = 1; |
| 774 | break; |
| 775 | } |
| 776 | } |
| 777 | |
| 778 | /* Error out if we didn't find a destination. */ |
| 779 | if (!written) |
| 780 | { |
| 781 | ax_debug ("Destination of goto %d not found\n", |
| 782 | aentry->goto_pc); |
| 783 | return expr_eval_invalid_goto; |
| 784 | } |
| 785 | } |
| 786 | |
| 787 | return expr_eval_no_error; |
| 788 | } |
| 789 | |
| 790 | #endif |
| 791 | |
| 792 | /* The agent expression evaluator, as specified by the GDB docs. It |
| 793 | returns 0 if everything went OK, and a nonzero error code |
| 794 | otherwise. */ |
| 795 | |
| 796 | enum eval_result_type |
| 797 | gdb_eval_agent_expr (struct regcache *regcache, |
| 798 | struct traceframe *tframe, |
| 799 | struct agent_expr *aexpr, |
| 800 | ULONGEST *rslt) |
| 801 | { |
| 802 | int pc = 0; |
| 803 | #define STACK_MAX 100 |
| 804 | ULONGEST stack[STACK_MAX], top; |
| 805 | int sp = 0; |
| 806 | unsigned char op; |
| 807 | int arg; |
| 808 | |
| 809 | /* This union is a convenient way to convert representations. For |
| 810 | now, assume a standard architecture where the hardware integer |
| 811 | types have 8, 16, 32, 64 bit types. A more robust solution would |
| 812 | be to import stdint.h from gnulib. */ |
| 813 | union |
| 814 | { |
| 815 | union |
| 816 | { |
| 817 | unsigned char bytes[1]; |
| 818 | unsigned char val; |
| 819 | } u8; |
| 820 | union |
| 821 | { |
| 822 | unsigned char bytes[2]; |
| 823 | unsigned short val; |
| 824 | } u16; |
| 825 | union |
| 826 | { |
| 827 | unsigned char bytes[4]; |
| 828 | unsigned int val; |
| 829 | } u32; |
| 830 | union |
| 831 | { |
| 832 | unsigned char bytes[8]; |
| 833 | ULONGEST val; |
| 834 | } u64; |
| 835 | } cnv; |
| 836 | |
| 837 | if (aexpr->length == 0) |
| 838 | { |
| 839 | ax_debug ("empty agent expression"); |
| 840 | return expr_eval_empty_expression; |
| 841 | } |
| 842 | |
| 843 | /* Cache the stack top in its own variable. Much of the time we can |
| 844 | operate on this variable, rather than dinking with the stack. It |
| 845 | needs to be copied to the stack when sp changes. */ |
| 846 | top = 0; |
| 847 | |
| 848 | while (1) |
| 849 | { |
| 850 | op = aexpr->bytes[pc++]; |
| 851 | |
| 852 | ax_debug ("About to interpret byte 0x%x", op); |
| 853 | |
| 854 | switch (op) |
| 855 | { |
| 856 | case gdb_agent_op_add: |
| 857 | top += stack[--sp]; |
| 858 | break; |
| 859 | |
| 860 | case gdb_agent_op_sub: |
| 861 | top = stack[--sp] - top; |
| 862 | break; |
| 863 | |
| 864 | case gdb_agent_op_mul: |
| 865 | top *= stack[--sp]; |
| 866 | break; |
| 867 | |
| 868 | case gdb_agent_op_div_signed: |
| 869 | if (top == 0) |
| 870 | { |
| 871 | ax_debug ("Attempted to divide by zero"); |
| 872 | return expr_eval_divide_by_zero; |
| 873 | } |
| 874 | top = ((LONGEST) stack[--sp]) / ((LONGEST) top); |
| 875 | break; |
| 876 | |
| 877 | case gdb_agent_op_div_unsigned: |
| 878 | if (top == 0) |
| 879 | { |
| 880 | ax_debug ("Attempted to divide by zero"); |
| 881 | return expr_eval_divide_by_zero; |
| 882 | } |
| 883 | top = stack[--sp] / top; |
| 884 | break; |
| 885 | |
| 886 | case gdb_agent_op_rem_signed: |
| 887 | if (top == 0) |
| 888 | { |
| 889 | ax_debug ("Attempted to divide by zero"); |
| 890 | return expr_eval_divide_by_zero; |
| 891 | } |
| 892 | top = ((LONGEST) stack[--sp]) % ((LONGEST) top); |
| 893 | break; |
| 894 | |
| 895 | case gdb_agent_op_rem_unsigned: |
| 896 | if (top == 0) |
| 897 | { |
| 898 | ax_debug ("Attempted to divide by zero"); |
| 899 | return expr_eval_divide_by_zero; |
| 900 | } |
| 901 | top = stack[--sp] % top; |
| 902 | break; |
| 903 | |
| 904 | case gdb_agent_op_lsh: |
| 905 | top = stack[--sp] << top; |
| 906 | break; |
| 907 | |
| 908 | case gdb_agent_op_rsh_signed: |
| 909 | top = ((LONGEST) stack[--sp]) >> top; |
| 910 | break; |
| 911 | |
| 912 | case gdb_agent_op_rsh_unsigned: |
| 913 | top = stack[--sp] >> top; |
| 914 | break; |
| 915 | |
| 916 | case gdb_agent_op_trace: |
| 917 | agent_mem_read (tframe, |
| 918 | NULL, (CORE_ADDR) stack[--sp], (ULONGEST) top); |
| 919 | if (--sp >= 0) |
| 920 | top = stack[sp]; |
| 921 | break; |
| 922 | |
| 923 | case gdb_agent_op_trace_quick: |
| 924 | arg = aexpr->bytes[pc++]; |
| 925 | agent_mem_read (tframe, NULL, (CORE_ADDR) top, (ULONGEST) arg); |
| 926 | break; |
| 927 | |
| 928 | case gdb_agent_op_log_not: |
| 929 | top = !top; |
| 930 | break; |
| 931 | |
| 932 | case gdb_agent_op_bit_and: |
| 933 | top &= stack[--sp]; |
| 934 | break; |
| 935 | |
| 936 | case gdb_agent_op_bit_or: |
| 937 | top |= stack[--sp]; |
| 938 | break; |
| 939 | |
| 940 | case gdb_agent_op_bit_xor: |
| 941 | top ^= stack[--sp]; |
| 942 | break; |
| 943 | |
| 944 | case gdb_agent_op_bit_not: |
| 945 | top = ~top; |
| 946 | break; |
| 947 | |
| 948 | case gdb_agent_op_equal: |
| 949 | top = (stack[--sp] == top); |
| 950 | break; |
| 951 | |
| 952 | case gdb_agent_op_less_signed: |
| 953 | top = (((LONGEST) stack[--sp]) < ((LONGEST) top)); |
| 954 | break; |
| 955 | |
| 956 | case gdb_agent_op_less_unsigned: |
| 957 | top = (stack[--sp] < top); |
| 958 | break; |
| 959 | |
| 960 | case gdb_agent_op_ext: |
| 961 | arg = aexpr->bytes[pc++]; |
| 962 | if (arg < (sizeof (LONGEST) * 8)) |
| 963 | { |
| 964 | LONGEST mask = 1 << (arg - 1); |
| 965 | top &= ((LONGEST) 1 << arg) - 1; |
| 966 | top = (top ^ mask) - mask; |
| 967 | } |
| 968 | break; |
| 969 | |
| 970 | case gdb_agent_op_ref8: |
| 971 | agent_mem_read (tframe, cnv.u8.bytes, (CORE_ADDR) top, 1); |
| 972 | top = cnv.u8.val; |
| 973 | break; |
| 974 | |
| 975 | case gdb_agent_op_ref16: |
| 976 | agent_mem_read (tframe, cnv.u16.bytes, (CORE_ADDR) top, 2); |
| 977 | top = cnv.u16.val; |
| 978 | break; |
| 979 | |
| 980 | case gdb_agent_op_ref32: |
| 981 | agent_mem_read (tframe, cnv.u32.bytes, (CORE_ADDR) top, 4); |
| 982 | top = cnv.u32.val; |
| 983 | break; |
| 984 | |
| 985 | case gdb_agent_op_ref64: |
| 986 | agent_mem_read (tframe, cnv.u64.bytes, (CORE_ADDR) top, 8); |
| 987 | top = cnv.u64.val; |
| 988 | break; |
| 989 | |
| 990 | case gdb_agent_op_if_goto: |
| 991 | if (top) |
| 992 | pc = (aexpr->bytes[pc] << 8) + (aexpr->bytes[pc + 1]); |
| 993 | else |
| 994 | pc += 2; |
| 995 | if (--sp >= 0) |
| 996 | top = stack[sp]; |
| 997 | break; |
| 998 | |
| 999 | case gdb_agent_op_goto: |
| 1000 | pc = (aexpr->bytes[pc] << 8) + (aexpr->bytes[pc + 1]); |
| 1001 | break; |
| 1002 | |
| 1003 | case gdb_agent_op_const8: |
| 1004 | /* Flush the cached stack top. */ |
| 1005 | stack[sp++] = top; |
| 1006 | top = aexpr->bytes[pc++]; |
| 1007 | break; |
| 1008 | |
| 1009 | case gdb_agent_op_const16: |
| 1010 | /* Flush the cached stack top. */ |
| 1011 | stack[sp++] = top; |
| 1012 | top = aexpr->bytes[pc++]; |
| 1013 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1014 | break; |
| 1015 | |
| 1016 | case gdb_agent_op_const32: |
| 1017 | /* Flush the cached stack top. */ |
| 1018 | stack[sp++] = top; |
| 1019 | top = aexpr->bytes[pc++]; |
| 1020 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1021 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1022 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1023 | break; |
| 1024 | |
| 1025 | case gdb_agent_op_const64: |
| 1026 | /* Flush the cached stack top. */ |
| 1027 | stack[sp++] = top; |
| 1028 | top = aexpr->bytes[pc++]; |
| 1029 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1030 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1031 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1032 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1033 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1034 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1035 | top = (top << 8) + aexpr->bytes[pc++]; |
| 1036 | break; |
| 1037 | |
| 1038 | case gdb_agent_op_reg: |
| 1039 | /* Flush the cached stack top. */ |
| 1040 | stack[sp++] = top; |
| 1041 | arg = aexpr->bytes[pc++]; |
| 1042 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 1043 | { |
| 1044 | int regnum = arg; |
| 1045 | |
| 1046 | switch (register_size (regnum)) |
| 1047 | { |
| 1048 | case 8: |
| 1049 | collect_register (regcache, regnum, cnv.u64.bytes); |
| 1050 | top = cnv.u64.val; |
| 1051 | break; |
| 1052 | case 4: |
| 1053 | collect_register (regcache, regnum, cnv.u32.bytes); |
| 1054 | top = cnv.u32.val; |
| 1055 | break; |
| 1056 | case 2: |
| 1057 | collect_register (regcache, regnum, cnv.u16.bytes); |
| 1058 | top = cnv.u16.val; |
| 1059 | break; |
| 1060 | case 1: |
| 1061 | collect_register (regcache, regnum, cnv.u8.bytes); |
| 1062 | top = cnv.u8.val; |
| 1063 | break; |
| 1064 | default: |
| 1065 | internal_error (__FILE__, __LINE__, |
| 1066 | "unhandled register size"); |
| 1067 | } |
| 1068 | } |
| 1069 | break; |
| 1070 | |
| 1071 | case gdb_agent_op_end: |
| 1072 | ax_debug ("At end of expression, sp=%d, stack top cache=0x%s", |
| 1073 | sp, pulongest (top)); |
| 1074 | if (rslt) |
| 1075 | { |
| 1076 | if (sp <= 0) |
| 1077 | { |
| 1078 | /* This should be an error */ |
| 1079 | ax_debug ("Stack is empty, nothing to return"); |
| 1080 | return expr_eval_empty_stack; |
| 1081 | } |
| 1082 | *rslt = top; |
| 1083 | } |
| 1084 | return expr_eval_no_error; |
| 1085 | |
| 1086 | case gdb_agent_op_dup: |
| 1087 | stack[sp++] = top; |
| 1088 | break; |
| 1089 | |
| 1090 | case gdb_agent_op_pop: |
| 1091 | if (--sp >= 0) |
| 1092 | top = stack[sp]; |
| 1093 | break; |
| 1094 | |
| 1095 | case gdb_agent_op_pick: |
| 1096 | arg = aexpr->bytes[pc++]; |
| 1097 | stack[sp] = top; |
| 1098 | top = stack[sp - arg]; |
| 1099 | ++sp; |
| 1100 | break; |
| 1101 | |
| 1102 | case gdb_agent_op_rot: |
| 1103 | { |
| 1104 | ULONGEST tem = stack[sp - 1]; |
| 1105 | |
| 1106 | stack[sp - 1] = stack[sp - 2]; |
| 1107 | stack[sp - 2] = top; |
| 1108 | top = tem; |
| 1109 | } |
| 1110 | break; |
| 1111 | |
| 1112 | case gdb_agent_op_zero_ext: |
| 1113 | arg = aexpr->bytes[pc++]; |
| 1114 | if (arg < (sizeof (LONGEST) * 8)) |
| 1115 | top &= ((LONGEST) 1 << arg) - 1; |
| 1116 | break; |
| 1117 | |
| 1118 | case gdb_agent_op_swap: |
| 1119 | /* Interchange top two stack elements, making sure top gets |
| 1120 | copied back onto stack. */ |
| 1121 | stack[sp] = top; |
| 1122 | top = stack[sp - 1]; |
| 1123 | stack[sp - 1] = stack[sp]; |
| 1124 | break; |
| 1125 | |
| 1126 | case gdb_agent_op_getv: |
| 1127 | /* Flush the cached stack top. */ |
| 1128 | stack[sp++] = top; |
| 1129 | arg = aexpr->bytes[pc++]; |
| 1130 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 1131 | top = agent_get_trace_state_variable_value (arg); |
| 1132 | break; |
| 1133 | |
| 1134 | case gdb_agent_op_setv: |
| 1135 | arg = aexpr->bytes[pc++]; |
| 1136 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 1137 | agent_set_trace_state_variable_value (arg, top); |
| 1138 | /* Note that we leave the value on the stack, for the |
| 1139 | benefit of later/enclosing expressions. */ |
| 1140 | break; |
| 1141 | |
| 1142 | case gdb_agent_op_tracev: |
| 1143 | arg = aexpr->bytes[pc++]; |
| 1144 | arg = (arg << 8) + aexpr->bytes[pc++]; |
| 1145 | agent_tsv_read (tframe, arg); |
| 1146 | break; |
| 1147 | |
| 1148 | case gdb_agent_op_tracenz: |
| 1149 | agent_mem_read_string (tframe, NULL, (CORE_ADDR) stack[--sp], |
| 1150 | (ULONGEST) top); |
| 1151 | if (--sp >= 0) |
| 1152 | top = stack[sp]; |
| 1153 | break; |
| 1154 | |
| 1155 | /* GDB never (currently) generates any of these ops. */ |
| 1156 | case gdb_agent_op_float: |
| 1157 | case gdb_agent_op_ref_float: |
| 1158 | case gdb_agent_op_ref_double: |
| 1159 | case gdb_agent_op_ref_long_double: |
| 1160 | case gdb_agent_op_l_to_d: |
| 1161 | case gdb_agent_op_d_to_l: |
| 1162 | case gdb_agent_op_trace16: |
| 1163 | ax_debug ("Agent expression op 0x%x valid, but not handled", |
| 1164 | op); |
| 1165 | /* If ever GDB generates any of these, we don't have the |
| 1166 | option of ignoring. */ |
| 1167 | return 1; |
| 1168 | |
| 1169 | default: |
| 1170 | ax_debug ("Agent expression op 0x%x not recognized", op); |
| 1171 | /* Don't struggle on, things will just get worse. */ |
| 1172 | return expr_eval_unrecognized_opcode; |
| 1173 | } |
| 1174 | |
| 1175 | /* Check for stack badness. */ |
| 1176 | if (sp >= (STACK_MAX - 1)) |
| 1177 | { |
| 1178 | ax_debug ("Expression stack overflow"); |
| 1179 | return expr_eval_stack_overflow; |
| 1180 | } |
| 1181 | |
| 1182 | if (sp < 0) |
| 1183 | { |
| 1184 | ax_debug ("Expression stack underflow"); |
| 1185 | return expr_eval_stack_underflow; |
| 1186 | } |
| 1187 | |
| 1188 | ax_debug ("Op %s -> sp=%d, top=0x%s", |
| 1189 | gdb_agent_op_name (op), sp, pulongest (top)); |
| 1190 | } |
| 1191 | } |