| 1 | /* Functions for manipulating expressions designed to be executed on the agent |
| 2 | Copyright (C) 1998-2000, 2007-2012 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 | /* Despite what the above comment says about this file being part of |
| 20 | GDB, we would like to keep these functions free of GDB |
| 21 | dependencies, since we want to be able to use them in contexts |
| 22 | outside of GDB (test suites, the stub, etc.) */ |
| 23 | |
| 24 | #include "defs.h" |
| 25 | #include "ax.h" |
| 26 | |
| 27 | #include "value.h" |
| 28 | #include "gdb_string.h" |
| 29 | |
| 30 | #include "user-regs.h" |
| 31 | |
| 32 | static void grow_expr (struct agent_expr *x, int n); |
| 33 | |
| 34 | static void append_const (struct agent_expr *x, LONGEST val, int n); |
| 35 | |
| 36 | static LONGEST read_const (struct agent_expr *x, int o, int n); |
| 37 | |
| 38 | static void generic_ext (struct agent_expr *x, enum agent_op op, int n); |
| 39 | \f |
| 40 | /* Functions for building expressions. */ |
| 41 | |
| 42 | /* Allocate a new, empty agent expression. */ |
| 43 | struct agent_expr * |
| 44 | new_agent_expr (struct gdbarch *gdbarch, CORE_ADDR scope) |
| 45 | { |
| 46 | struct agent_expr *x = xmalloc (sizeof (*x)); |
| 47 | |
| 48 | x->len = 0; |
| 49 | x->size = 1; /* Change this to a larger value once |
| 50 | reallocation code is tested. */ |
| 51 | x->buf = xmalloc (x->size); |
| 52 | |
| 53 | x->gdbarch = gdbarch; |
| 54 | x->scope = scope; |
| 55 | |
| 56 | /* Bit vector for registers used. */ |
| 57 | x->reg_mask_len = 1; |
| 58 | x->reg_mask = xmalloc (x->reg_mask_len * sizeof (x->reg_mask[0])); |
| 59 | memset (x->reg_mask, 0, x->reg_mask_len * sizeof (x->reg_mask[0])); |
| 60 | |
| 61 | return x; |
| 62 | } |
| 63 | |
| 64 | /* Free a agent expression. */ |
| 65 | void |
| 66 | free_agent_expr (struct agent_expr *x) |
| 67 | { |
| 68 | xfree (x->buf); |
| 69 | xfree (x->reg_mask); |
| 70 | xfree (x); |
| 71 | } |
| 72 | |
| 73 | static void |
| 74 | do_free_agent_expr_cleanup (void *x) |
| 75 | { |
| 76 | free_agent_expr (x); |
| 77 | } |
| 78 | |
| 79 | struct cleanup * |
| 80 | make_cleanup_free_agent_expr (struct agent_expr *x) |
| 81 | { |
| 82 | return make_cleanup (do_free_agent_expr_cleanup, x); |
| 83 | } |
| 84 | |
| 85 | |
| 86 | /* Make sure that X has room for at least N more bytes. This doesn't |
| 87 | affect the length, just the allocated size. */ |
| 88 | static void |
| 89 | grow_expr (struct agent_expr *x, int n) |
| 90 | { |
| 91 | if (x->len + n > x->size) |
| 92 | { |
| 93 | x->size *= 2; |
| 94 | if (x->size < x->len + n) |
| 95 | x->size = x->len + n + 10; |
| 96 | x->buf = xrealloc (x->buf, x->size); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | |
| 101 | /* Append the low N bytes of VAL as an N-byte integer to the |
| 102 | expression X, in big-endian order. */ |
| 103 | static void |
| 104 | append_const (struct agent_expr *x, LONGEST val, int n) |
| 105 | { |
| 106 | int i; |
| 107 | |
| 108 | grow_expr (x, n); |
| 109 | for (i = n - 1; i >= 0; i--) |
| 110 | { |
| 111 | x->buf[x->len + i] = val & 0xff; |
| 112 | val >>= 8; |
| 113 | } |
| 114 | x->len += n; |
| 115 | } |
| 116 | |
| 117 | |
| 118 | /* Extract an N-byte big-endian unsigned integer from expression X at |
| 119 | offset O. */ |
| 120 | static LONGEST |
| 121 | read_const (struct agent_expr *x, int o, int n) |
| 122 | { |
| 123 | int i; |
| 124 | LONGEST accum = 0; |
| 125 | |
| 126 | /* Make sure we're not reading off the end of the expression. */ |
| 127 | if (o + n > x->len) |
| 128 | error (_("GDB bug: ax-general.c (read_const): incomplete constant")); |
| 129 | |
| 130 | for (i = 0; i < n; i++) |
| 131 | accum = (accum << 8) | x->buf[o + i]; |
| 132 | |
| 133 | return accum; |
| 134 | } |
| 135 | |
| 136 | |
| 137 | /* Append a simple operator OP to EXPR. */ |
| 138 | void |
| 139 | ax_simple (struct agent_expr *x, enum agent_op op) |
| 140 | { |
| 141 | grow_expr (x, 1); |
| 142 | x->buf[x->len++] = op; |
| 143 | } |
| 144 | |
| 145 | /* Append a pick operator to EXPR. DEPTH is the stack item to pick, |
| 146 | with 0 being top of stack. */ |
| 147 | |
| 148 | void |
| 149 | ax_pick (struct agent_expr *x, int depth) |
| 150 | { |
| 151 | if (depth < 0 || depth > 255) |
| 152 | error (_("GDB bug: ax-general.c (ax_pick): stack depth out of range")); |
| 153 | ax_simple (x, aop_pick); |
| 154 | append_const (x, 1, depth); |
| 155 | } |
| 156 | |
| 157 | |
| 158 | /* Append a sign-extension or zero-extension instruction to EXPR, to |
| 159 | extend an N-bit value. */ |
| 160 | static void |
| 161 | generic_ext (struct agent_expr *x, enum agent_op op, int n) |
| 162 | { |
| 163 | /* N must fit in a byte. */ |
| 164 | if (n < 0 || n > 255) |
| 165 | error (_("GDB bug: ax-general.c (generic_ext): bit count out of range")); |
| 166 | /* That had better be enough range. */ |
| 167 | if (sizeof (LONGEST) * 8 > 255) |
| 168 | error (_("GDB bug: ax-general.c (generic_ext): " |
| 169 | "opcode has inadequate range")); |
| 170 | |
| 171 | grow_expr (x, 2); |
| 172 | x->buf[x->len++] = op; |
| 173 | x->buf[x->len++] = n; |
| 174 | } |
| 175 | |
| 176 | |
| 177 | /* Append a sign-extension instruction to EXPR, to extend an N-bit value. */ |
| 178 | void |
| 179 | ax_ext (struct agent_expr *x, int n) |
| 180 | { |
| 181 | generic_ext (x, aop_ext, n); |
| 182 | } |
| 183 | |
| 184 | |
| 185 | /* Append a zero-extension instruction to EXPR, to extend an N-bit value. */ |
| 186 | void |
| 187 | ax_zero_ext (struct agent_expr *x, int n) |
| 188 | { |
| 189 | generic_ext (x, aop_zero_ext, n); |
| 190 | } |
| 191 | |
| 192 | |
| 193 | /* Append a trace_quick instruction to EXPR, to record N bytes. */ |
| 194 | void |
| 195 | ax_trace_quick (struct agent_expr *x, int n) |
| 196 | { |
| 197 | /* N must fit in a byte. */ |
| 198 | if (n < 0 || n > 255) |
| 199 | error (_("GDB bug: ax-general.c (ax_trace_quick): " |
| 200 | "size out of range for trace_quick")); |
| 201 | |
| 202 | grow_expr (x, 2); |
| 203 | x->buf[x->len++] = aop_trace_quick; |
| 204 | x->buf[x->len++] = n; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | /* Append a goto op to EXPR. OP is the actual op (must be aop_goto or |
| 209 | aop_if_goto). We assume we don't know the target offset yet, |
| 210 | because it's probably a forward branch, so we leave space in EXPR |
| 211 | for the target, and return the offset in EXPR of that space, so we |
| 212 | can backpatch it once we do know the target offset. Use ax_label |
| 213 | to do the backpatching. */ |
| 214 | int |
| 215 | ax_goto (struct agent_expr *x, enum agent_op op) |
| 216 | { |
| 217 | grow_expr (x, 3); |
| 218 | x->buf[x->len + 0] = op; |
| 219 | x->buf[x->len + 1] = 0xff; |
| 220 | x->buf[x->len + 2] = 0xff; |
| 221 | x->len += 3; |
| 222 | return x->len - 2; |
| 223 | } |
| 224 | |
| 225 | /* Suppose a given call to ax_goto returns some value PATCH. When you |
| 226 | know the offset TARGET that goto should jump to, call |
| 227 | ax_label (EXPR, PATCH, TARGET) |
| 228 | to patch TARGET into the ax_goto instruction. */ |
| 229 | void |
| 230 | ax_label (struct agent_expr *x, int patch, int target) |
| 231 | { |
| 232 | /* Make sure the value is in range. Don't accept 0xffff as an |
| 233 | offset; that's our magic sentinel value for unpatched branches. */ |
| 234 | if (target < 0 || target >= 0xffff) |
| 235 | error (_("GDB bug: ax-general.c (ax_label): label target out of range")); |
| 236 | |
| 237 | x->buf[patch] = (target >> 8) & 0xff; |
| 238 | x->buf[patch + 1] = target & 0xff; |
| 239 | } |
| 240 | |
| 241 | |
| 242 | /* Assemble code to push a constant on the stack. */ |
| 243 | void |
| 244 | ax_const_l (struct agent_expr *x, LONGEST l) |
| 245 | { |
| 246 | static enum agent_op ops[] |
| 247 | = |
| 248 | {aop_const8, aop_const16, aop_const32, aop_const64}; |
| 249 | int size; |
| 250 | int op; |
| 251 | |
| 252 | /* How big is the number? 'op' keeps track of which opcode to use. |
| 253 | Notice that we don't really care whether the original number was |
| 254 | signed or unsigned; we always reproduce the value exactly, and |
| 255 | use the shortest representation. */ |
| 256 | for (op = 0, size = 8; size < 64; size *= 2, op++) |
| 257 | { |
| 258 | LONGEST lim = ((LONGEST) 1) << (size - 1); |
| 259 | |
| 260 | if (-lim <= l && l <= lim - 1) |
| 261 | break; |
| 262 | } |
| 263 | |
| 264 | /* Emit the right opcode... */ |
| 265 | ax_simple (x, ops[op]); |
| 266 | |
| 267 | /* Emit the low SIZE bytes as an unsigned number. We know that |
| 268 | sign-extending this will yield l. */ |
| 269 | append_const (x, l, size / 8); |
| 270 | |
| 271 | /* Now, if it was negative, and not full-sized, sign-extend it. */ |
| 272 | if (l < 0 && size < 64) |
| 273 | ax_ext (x, size); |
| 274 | } |
| 275 | |
| 276 | |
| 277 | void |
| 278 | ax_const_d (struct agent_expr *x, LONGEST d) |
| 279 | { |
| 280 | /* FIXME: floating-point support not present yet. */ |
| 281 | error (_("GDB bug: ax-general.c (ax_const_d): " |
| 282 | "floating point not supported yet")); |
| 283 | } |
| 284 | |
| 285 | |
| 286 | /* Assemble code to push the value of register number REG on the |
| 287 | stack. */ |
| 288 | void |
| 289 | ax_reg (struct agent_expr *x, int reg) |
| 290 | { |
| 291 | if (reg >= gdbarch_num_regs (x->gdbarch)) |
| 292 | { |
| 293 | /* This is a pseudo-register. */ |
| 294 | if (!gdbarch_ax_pseudo_register_push_stack_p (x->gdbarch)) |
| 295 | error (_("'%s' is a pseudo-register; " |
| 296 | "GDB cannot yet trace its contents."), |
| 297 | user_reg_map_regnum_to_name (x->gdbarch, reg)); |
| 298 | if (gdbarch_ax_pseudo_register_push_stack (x->gdbarch, x, reg)) |
| 299 | error (_("Trace '%s' failed."), |
| 300 | user_reg_map_regnum_to_name (x->gdbarch, reg)); |
| 301 | } |
| 302 | else |
| 303 | { |
| 304 | /* Make sure the register number is in range. */ |
| 305 | if (reg < 0 || reg > 0xffff) |
| 306 | error (_("GDB bug: ax-general.c (ax_reg): " |
| 307 | "register number out of range")); |
| 308 | grow_expr (x, 3); |
| 309 | x->buf[x->len] = aop_reg; |
| 310 | x->buf[x->len + 1] = (reg >> 8) & 0xff; |
| 311 | x->buf[x->len + 2] = (reg) & 0xff; |
| 312 | x->len += 3; |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | /* Assemble code to operate on a trace state variable. */ |
| 317 | |
| 318 | void |
| 319 | ax_tsv (struct agent_expr *x, enum agent_op op, int num) |
| 320 | { |
| 321 | /* Make sure the tsv number is in range. */ |
| 322 | if (num < 0 || num > 0xffff) |
| 323 | internal_error (__FILE__, __LINE__, |
| 324 | _("ax-general.c (ax_tsv): variable " |
| 325 | "number is %d, out of range"), num); |
| 326 | |
| 327 | grow_expr (x, 3); |
| 328 | x->buf[x->len] = op; |
| 329 | x->buf[x->len + 1] = (num >> 8) & 0xff; |
| 330 | x->buf[x->len + 2] = (num) & 0xff; |
| 331 | x->len += 3; |
| 332 | } |
| 333 | |
| 334 | /* Append a string to the expression. Note that the string is going |
| 335 | into the bytecodes directly, not on the stack. As a precaution, |
| 336 | include both length as prefix, and terminate with a NUL. (The NUL |
| 337 | is counted in the length.) */ |
| 338 | |
| 339 | void |
| 340 | ax_string (struct agent_expr *x, char *str, int slen) |
| 341 | { |
| 342 | int i; |
| 343 | |
| 344 | /* Make sure the string length is reasonable. */ |
| 345 | if (slen < 0 || slen > 0xffff) |
| 346 | internal_error (__FILE__, __LINE__, |
| 347 | _("ax-general.c (ax_string): string " |
| 348 | "length is %d, out of allowed range"), slen); |
| 349 | |
| 350 | grow_expr (x, 2 + slen + 1); |
| 351 | x->buf[x->len++] = ((slen + 1) >> 8) & 0xff; |
| 352 | x->buf[x->len++] = (slen + 1) & 0xff; |
| 353 | for (i = 0; i < slen; ++i) |
| 354 | x->buf[x->len++] = str[i]; |
| 355 | x->buf[x->len++] = '\0'; |
| 356 | } |
| 357 | \f |
| 358 | |
| 359 | |
| 360 | /* Functions for disassembling agent expressions, and otherwise |
| 361 | debugging the expression compiler. */ |
| 362 | |
| 363 | struct aop_map aop_map[] = |
| 364 | { |
| 365 | {0, 0, 0, 0, 0} |
| 366 | #define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE) \ |
| 367 | , { # NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED } |
| 368 | #include "ax.def" |
| 369 | #undef DEFOP |
| 370 | }; |
| 371 | |
| 372 | |
| 373 | /* Disassemble the expression EXPR, writing to F. */ |
| 374 | void |
| 375 | ax_print (struct ui_file *f, struct agent_expr *x) |
| 376 | { |
| 377 | int i; |
| 378 | int is_float = 0; |
| 379 | |
| 380 | fprintf_filtered (f, _("Scope: %s\n"), paddress (x->gdbarch, x->scope)); |
| 381 | fprintf_filtered (f, _("Reg mask:")); |
| 382 | for (i = 0; i < x->reg_mask_len; ++i) |
| 383 | fprintf_filtered (f, _(" %02x"), x->reg_mask[i]); |
| 384 | fprintf_filtered (f, _("\n")); |
| 385 | |
| 386 | /* Check the size of the name array against the number of entries in |
| 387 | the enum, to catch additions that people didn't sync. */ |
| 388 | if ((sizeof (aop_map) / sizeof (aop_map[0])) |
| 389 | != aop_last) |
| 390 | error (_("GDB bug: ax-general.c (ax_print): opcode map out of sync")); |
| 391 | |
| 392 | for (i = 0; i < x->len;) |
| 393 | { |
| 394 | enum agent_op op = x->buf[i]; |
| 395 | |
| 396 | if (op >= (sizeof (aop_map) / sizeof (aop_map[0])) |
| 397 | || !aop_map[op].name) |
| 398 | { |
| 399 | fprintf_filtered (f, _("%3d <bad opcode %02x>\n"), i, op); |
| 400 | i++; |
| 401 | continue; |
| 402 | } |
| 403 | if (i + 1 + aop_map[op].op_size > x->len) |
| 404 | { |
| 405 | fprintf_filtered (f, _("%3d <incomplete opcode %s>\n"), |
| 406 | i, aop_map[op].name); |
| 407 | break; |
| 408 | } |
| 409 | |
| 410 | fprintf_filtered (f, "%3d %s", i, aop_map[op].name); |
| 411 | if (aop_map[op].op_size > 0) |
| 412 | { |
| 413 | fputs_filtered (" ", f); |
| 414 | |
| 415 | print_longest (f, 'd', 0, |
| 416 | read_const (x, i + 1, aop_map[op].op_size)); |
| 417 | } |
| 418 | /* Handle the complicated printf arguments specially. */ |
| 419 | else if (op == aop_printf) |
| 420 | { |
| 421 | int slen, nargs; |
| 422 | |
| 423 | i++; |
| 424 | nargs = x->buf[i++]; |
| 425 | slen = x->buf[i++]; |
| 426 | slen = slen * 256 + x->buf[i++]; |
| 427 | fprintf_filtered (f, _(" \"%s\", %d args"), |
| 428 | &(x->buf[i]), nargs); |
| 429 | i += slen - 1; |
| 430 | } |
| 431 | fprintf_filtered (f, "\n"); |
| 432 | i += 1 + aop_map[op].op_size; |
| 433 | |
| 434 | is_float = (op == aop_float); |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | /* Add register REG to the register mask for expression AX. */ |
| 439 | void |
| 440 | ax_reg_mask (struct agent_expr *ax, int reg) |
| 441 | { |
| 442 | if (reg >= gdbarch_num_regs (ax->gdbarch)) |
| 443 | { |
| 444 | /* This is a pseudo-register. */ |
| 445 | if (!gdbarch_ax_pseudo_register_collect_p (ax->gdbarch)) |
| 446 | error (_("'%s' is a pseudo-register; " |
| 447 | "GDB cannot yet trace its contents."), |
| 448 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); |
| 449 | if (gdbarch_ax_pseudo_register_collect (ax->gdbarch, ax, reg)) |
| 450 | error (_("Trace '%s' failed."), |
| 451 | user_reg_map_regnum_to_name (ax->gdbarch, reg)); |
| 452 | } |
| 453 | else |
| 454 | { |
| 455 | int byte = reg / 8; |
| 456 | |
| 457 | /* Grow the bit mask if necessary. */ |
| 458 | if (byte >= ax->reg_mask_len) |
| 459 | { |
| 460 | /* It's not appropriate to double here. This isn't a |
| 461 | string buffer. */ |
| 462 | int new_len = byte + 1; |
| 463 | unsigned char *new_reg_mask = xrealloc (ax->reg_mask, |
| 464 | new_len |
| 465 | * sizeof (ax->reg_mask[0])); |
| 466 | memset (new_reg_mask + ax->reg_mask_len, 0, |
| 467 | (new_len - ax->reg_mask_len) * sizeof (ax->reg_mask[0])); |
| 468 | ax->reg_mask_len = new_len; |
| 469 | ax->reg_mask = new_reg_mask; |
| 470 | } |
| 471 | |
| 472 | ax->reg_mask[byte] |= 1 << (reg % 8); |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | /* Given an agent expression AX, fill in requirements and other descriptive |
| 477 | bits. */ |
| 478 | void |
| 479 | ax_reqs (struct agent_expr *ax) |
| 480 | { |
| 481 | int i; |
| 482 | int height; |
| 483 | |
| 484 | /* Jump target table. targets[i] is non-zero iff we have found a |
| 485 | jump to offset i. */ |
| 486 | char *targets = (char *) alloca (ax->len * sizeof (targets[0])); |
| 487 | |
| 488 | /* Instruction boundary table. boundary[i] is non-zero iff our scan |
| 489 | has reached an instruction starting at offset i. */ |
| 490 | char *boundary = (char *) alloca (ax->len * sizeof (boundary[0])); |
| 491 | |
| 492 | /* Stack height record. If either targets[i] or boundary[i] is |
| 493 | non-zero, heights[i] is the height the stack should have before |
| 494 | executing the bytecode at that point. */ |
| 495 | int *heights = (int *) alloca (ax->len * sizeof (heights[0])); |
| 496 | |
| 497 | /* Pointer to a description of the present op. */ |
| 498 | struct aop_map *op; |
| 499 | |
| 500 | memset (targets, 0, ax->len * sizeof (targets[0])); |
| 501 | memset (boundary, 0, ax->len * sizeof (boundary[0])); |
| 502 | |
| 503 | ax->max_height = ax->min_height = height = 0; |
| 504 | ax->flaw = agent_flaw_none; |
| 505 | ax->max_data_size = 0; |
| 506 | |
| 507 | for (i = 0; i < ax->len; i += 1 + op->op_size) |
| 508 | { |
| 509 | if (ax->buf[i] > (sizeof (aop_map) / sizeof (aop_map[0]))) |
| 510 | { |
| 511 | ax->flaw = agent_flaw_bad_instruction; |
| 512 | return; |
| 513 | } |
| 514 | |
| 515 | op = &aop_map[ax->buf[i]]; |
| 516 | |
| 517 | if (!op->name) |
| 518 | { |
| 519 | ax->flaw = agent_flaw_bad_instruction; |
| 520 | return; |
| 521 | } |
| 522 | |
| 523 | if (i + 1 + op->op_size > ax->len) |
| 524 | { |
| 525 | ax->flaw = agent_flaw_incomplete_instruction; |
| 526 | return; |
| 527 | } |
| 528 | |
| 529 | /* If this instruction is a forward jump target, does the |
| 530 | current stack height match the stack height at the jump |
| 531 | source? */ |
| 532 | if (targets[i] && (heights[i] != height)) |
| 533 | { |
| 534 | ax->flaw = agent_flaw_height_mismatch; |
| 535 | return; |
| 536 | } |
| 537 | |
| 538 | boundary[i] = 1; |
| 539 | heights[i] = height; |
| 540 | |
| 541 | height -= op->consumed; |
| 542 | if (height < ax->min_height) |
| 543 | ax->min_height = height; |
| 544 | height += op->produced; |
| 545 | if (height > ax->max_height) |
| 546 | ax->max_height = height; |
| 547 | |
| 548 | if (op->data_size > ax->max_data_size) |
| 549 | ax->max_data_size = op->data_size; |
| 550 | |
| 551 | /* For jump instructions, check that the target is a valid |
| 552 | offset. If it is, record the fact that that location is a |
| 553 | jump target, and record the height we expect there. */ |
| 554 | if (aop_goto == op - aop_map |
| 555 | || aop_if_goto == op - aop_map) |
| 556 | { |
| 557 | int target = read_const (ax, i + 1, 2); |
| 558 | if (target < 0 || target >= ax->len) |
| 559 | { |
| 560 | ax->flaw = agent_flaw_bad_jump; |
| 561 | return; |
| 562 | } |
| 563 | |
| 564 | /* Do we have any information about what the stack height |
| 565 | should be at the target? */ |
| 566 | if (targets[target] || boundary[target]) |
| 567 | { |
| 568 | if (heights[target] != height) |
| 569 | { |
| 570 | ax->flaw = agent_flaw_height_mismatch; |
| 571 | return; |
| 572 | } |
| 573 | } |
| 574 | |
| 575 | /* Record the target, along with the stack height we expect. */ |
| 576 | targets[target] = 1; |
| 577 | heights[target] = height; |
| 578 | } |
| 579 | |
| 580 | /* For unconditional jumps with a successor, check that the |
| 581 | successor is a target, and pick up its stack height. */ |
| 582 | if (aop_goto == op - aop_map |
| 583 | && i + 3 < ax->len) |
| 584 | { |
| 585 | if (!targets[i + 3]) |
| 586 | { |
| 587 | ax->flaw = agent_flaw_hole; |
| 588 | return; |
| 589 | } |
| 590 | |
| 591 | height = heights[i + 3]; |
| 592 | } |
| 593 | |
| 594 | /* For reg instructions, record the register in the bit mask. */ |
| 595 | if (aop_reg == op - aop_map) |
| 596 | { |
| 597 | int reg = read_const (ax, i + 1, 2); |
| 598 | |
| 599 | ax_reg_mask (ax, reg); |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | /* Check that all the targets are on boundaries. */ |
| 604 | for (i = 0; i < ax->len; i++) |
| 605 | if (targets[i] && !boundary[i]) |
| 606 | { |
| 607 | ax->flaw = agent_flaw_bad_jump; |
| 608 | return; |
| 609 | } |
| 610 | |
| 611 | ax->final_height = height; |
| 612 | } |