| 1 | /* DWARF 2 Expression Evaluator. |
| 2 | |
| 3 | Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008 |
| 4 | Free Software Foundation, Inc. |
| 5 | |
| 6 | Contributed by Daniel Berlin (dan@dberlin.org) |
| 7 | |
| 8 | This file is part of GDB. |
| 9 | |
| 10 | This program is free software; you can redistribute it and/or modify |
| 11 | it under the terms of the GNU General Public License as published by |
| 12 | the Free Software Foundation; either version 3 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU General Public License |
| 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "symtab.h" |
| 25 | #include "gdbtypes.h" |
| 26 | #include "value.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "elf/dwarf2.h" |
| 29 | #include "dwarf2expr.h" |
| 30 | |
| 31 | /* Local prototypes. */ |
| 32 | |
| 33 | static void execute_stack_op (struct dwarf_expr_context *, |
| 34 | gdb_byte *, gdb_byte *); |
| 35 | static struct type *unsigned_address_type (int); |
| 36 | |
| 37 | /* Create a new context for the expression evaluator. */ |
| 38 | |
| 39 | struct dwarf_expr_context * |
| 40 | new_dwarf_expr_context (void) |
| 41 | { |
| 42 | struct dwarf_expr_context *retval; |
| 43 | retval = xcalloc (1, sizeof (struct dwarf_expr_context)); |
| 44 | retval->stack_len = 0; |
| 45 | retval->stack_allocated = 10; |
| 46 | retval->stack = xmalloc (retval->stack_allocated * sizeof (CORE_ADDR)); |
| 47 | retval->num_pieces = 0; |
| 48 | retval->pieces = 0; |
| 49 | return retval; |
| 50 | } |
| 51 | |
| 52 | /* Release the memory allocated to CTX. */ |
| 53 | |
| 54 | void |
| 55 | free_dwarf_expr_context (struct dwarf_expr_context *ctx) |
| 56 | { |
| 57 | xfree (ctx->stack); |
| 58 | xfree (ctx->pieces); |
| 59 | xfree (ctx); |
| 60 | } |
| 61 | |
| 62 | /* Expand the memory allocated to CTX's stack to contain at least |
| 63 | NEED more elements than are currently used. */ |
| 64 | |
| 65 | static void |
| 66 | dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need) |
| 67 | { |
| 68 | if (ctx->stack_len + need > ctx->stack_allocated) |
| 69 | { |
| 70 | size_t newlen = ctx->stack_len + need + 10; |
| 71 | ctx->stack = xrealloc (ctx->stack, |
| 72 | newlen * sizeof (CORE_ADDR)); |
| 73 | ctx->stack_allocated = newlen; |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | /* Push VALUE onto CTX's stack. */ |
| 78 | |
| 79 | void |
| 80 | dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value) |
| 81 | { |
| 82 | dwarf_expr_grow_stack (ctx, 1); |
| 83 | ctx->stack[ctx->stack_len++] = value; |
| 84 | } |
| 85 | |
| 86 | /* Pop the top item off of CTX's stack. */ |
| 87 | |
| 88 | void |
| 89 | dwarf_expr_pop (struct dwarf_expr_context *ctx) |
| 90 | { |
| 91 | if (ctx->stack_len <= 0) |
| 92 | error (_("dwarf expression stack underflow")); |
| 93 | ctx->stack_len--; |
| 94 | } |
| 95 | |
| 96 | /* Retrieve the N'th item on CTX's stack. */ |
| 97 | |
| 98 | CORE_ADDR |
| 99 | dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n) |
| 100 | { |
| 101 | if (ctx->stack_len <= n) |
| 102 | error (_("Asked for position %d of stack, stack only has %d elements on it."), |
| 103 | n, ctx->stack_len); |
| 104 | return ctx->stack[ctx->stack_len - (1 + n)]; |
| 105 | |
| 106 | } |
| 107 | |
| 108 | /* Add a new piece to CTX's piece list. */ |
| 109 | static void |
| 110 | add_piece (struct dwarf_expr_context *ctx, |
| 111 | int in_reg, CORE_ADDR value, ULONGEST size) |
| 112 | { |
| 113 | struct dwarf_expr_piece *p; |
| 114 | |
| 115 | ctx->num_pieces++; |
| 116 | |
| 117 | if (ctx->pieces) |
| 118 | ctx->pieces = xrealloc (ctx->pieces, |
| 119 | (ctx->num_pieces |
| 120 | * sizeof (struct dwarf_expr_piece))); |
| 121 | else |
| 122 | ctx->pieces = xmalloc (ctx->num_pieces |
| 123 | * sizeof (struct dwarf_expr_piece)); |
| 124 | |
| 125 | p = &ctx->pieces[ctx->num_pieces - 1]; |
| 126 | p->in_reg = in_reg; |
| 127 | p->value = value; |
| 128 | p->size = size; |
| 129 | } |
| 130 | |
| 131 | /* Evaluate the expression at ADDR (LEN bytes long) using the context |
| 132 | CTX. */ |
| 133 | |
| 134 | void |
| 135 | dwarf_expr_eval (struct dwarf_expr_context *ctx, gdb_byte *addr, size_t len) |
| 136 | { |
| 137 | execute_stack_op (ctx, addr, addr + len); |
| 138 | } |
| 139 | |
| 140 | /* Decode the unsigned LEB128 constant at BUF into the variable pointed to |
| 141 | by R, and return the new value of BUF. Verify that it doesn't extend |
| 142 | past BUF_END. */ |
| 143 | |
| 144 | gdb_byte * |
| 145 | read_uleb128 (gdb_byte *buf, gdb_byte *buf_end, ULONGEST * r) |
| 146 | { |
| 147 | unsigned shift = 0; |
| 148 | ULONGEST result = 0; |
| 149 | gdb_byte byte; |
| 150 | |
| 151 | while (1) |
| 152 | { |
| 153 | if (buf >= buf_end) |
| 154 | error (_("read_uleb128: Corrupted DWARF expression.")); |
| 155 | |
| 156 | byte = *buf++; |
| 157 | result |= (byte & 0x7f) << shift; |
| 158 | if ((byte & 0x80) == 0) |
| 159 | break; |
| 160 | shift += 7; |
| 161 | } |
| 162 | *r = result; |
| 163 | return buf; |
| 164 | } |
| 165 | |
| 166 | /* Decode the signed LEB128 constant at BUF into the variable pointed to |
| 167 | by R, and return the new value of BUF. Verify that it doesn't extend |
| 168 | past BUF_END. */ |
| 169 | |
| 170 | gdb_byte * |
| 171 | read_sleb128 (gdb_byte *buf, gdb_byte *buf_end, LONGEST * r) |
| 172 | { |
| 173 | unsigned shift = 0; |
| 174 | LONGEST result = 0; |
| 175 | gdb_byte byte; |
| 176 | |
| 177 | while (1) |
| 178 | { |
| 179 | if (buf >= buf_end) |
| 180 | error (_("read_sleb128: Corrupted DWARF expression.")); |
| 181 | |
| 182 | byte = *buf++; |
| 183 | result |= (byte & 0x7f) << shift; |
| 184 | shift += 7; |
| 185 | if ((byte & 0x80) == 0) |
| 186 | break; |
| 187 | } |
| 188 | if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0) |
| 189 | result |= -(1 << shift); |
| 190 | |
| 191 | *r = result; |
| 192 | return buf; |
| 193 | } |
| 194 | |
| 195 | /* Read an address of size ADDR_SIZE from BUF, and verify that it |
| 196 | doesn't extend past BUF_END. */ |
| 197 | |
| 198 | CORE_ADDR |
| 199 | dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, int addr_size) |
| 200 | { |
| 201 | CORE_ADDR result; |
| 202 | |
| 203 | if (buf_end - buf < addr_size) |
| 204 | error (_("dwarf2_read_address: Corrupted DWARF expression.")); |
| 205 | |
| 206 | /* For most architectures, calling extract_unsigned_integer() alone |
| 207 | is sufficient for extracting an address. However, some |
| 208 | architectures (e.g. MIPS) use signed addresses and using |
| 209 | extract_unsigned_integer() will not produce a correct |
| 210 | result. Turning the unsigned integer into a value and then |
| 211 | decomposing that value as an address will cause |
| 212 | gdbarch_integer_to_address() to be invoked for those |
| 213 | architectures which require it. Thus, using value_as_address() |
| 214 | will produce the correct result for both types of architectures. |
| 215 | |
| 216 | One concern regarding the use of values for this purpose is |
| 217 | efficiency. Obviously, these extra calls will take more time to |
| 218 | execute and creating a value takes more space, space which will |
| 219 | have to be garbage collected at a later time. If constructing |
| 220 | and then decomposing a value for this purpose proves to be too |
| 221 | inefficient, then gdbarch_integer_to_address() can be called |
| 222 | directly. |
| 223 | |
| 224 | The use of `unsigned_address_type' in the code below refers to |
| 225 | the type of buf and has no bearing on the signedness of the |
| 226 | address being returned. */ |
| 227 | |
| 228 | result = value_as_address (value_from_longest |
| 229 | (unsigned_address_type (addr_size), |
| 230 | extract_unsigned_integer (buf, addr_size))); |
| 231 | return result; |
| 232 | } |
| 233 | |
| 234 | /* Return the type of an address of size ADDR_SIZE, |
| 235 | for unsigned arithmetic. */ |
| 236 | |
| 237 | static struct type * |
| 238 | unsigned_address_type (int addr_size) |
| 239 | { |
| 240 | switch (addr_size) |
| 241 | { |
| 242 | case 2: |
| 243 | return builtin_type_uint16; |
| 244 | case 4: |
| 245 | return builtin_type_uint32; |
| 246 | case 8: |
| 247 | return builtin_type_uint64; |
| 248 | default: |
| 249 | internal_error (__FILE__, __LINE__, |
| 250 | _("Unsupported address size.\n")); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /* Return the type of an address of size ADDR_SIZE, |
| 255 | for signed arithmetic. */ |
| 256 | |
| 257 | static struct type * |
| 258 | signed_address_type (int addr_size) |
| 259 | { |
| 260 | switch (addr_size) |
| 261 | { |
| 262 | case 2: |
| 263 | return builtin_type_int16; |
| 264 | case 4: |
| 265 | return builtin_type_int32; |
| 266 | case 8: |
| 267 | return builtin_type_int64; |
| 268 | default: |
| 269 | internal_error (__FILE__, __LINE__, |
| 270 | _("Unsupported address size.\n")); |
| 271 | } |
| 272 | } |
| 273 | \f |
| 274 | /* The engine for the expression evaluator. Using the context in CTX, |
| 275 | evaluate the expression between OP_PTR and OP_END. */ |
| 276 | |
| 277 | static void |
| 278 | execute_stack_op (struct dwarf_expr_context *ctx, |
| 279 | gdb_byte *op_ptr, gdb_byte *op_end) |
| 280 | { |
| 281 | ctx->in_reg = 0; |
| 282 | ctx->initialized = 1; /* Default is initialized. */ |
| 283 | |
| 284 | while (op_ptr < op_end) |
| 285 | { |
| 286 | enum dwarf_location_atom op = *op_ptr++; |
| 287 | CORE_ADDR result; |
| 288 | ULONGEST uoffset, reg; |
| 289 | LONGEST offset; |
| 290 | |
| 291 | switch (op) |
| 292 | { |
| 293 | case DW_OP_lit0: |
| 294 | case DW_OP_lit1: |
| 295 | case DW_OP_lit2: |
| 296 | case DW_OP_lit3: |
| 297 | case DW_OP_lit4: |
| 298 | case DW_OP_lit5: |
| 299 | case DW_OP_lit6: |
| 300 | case DW_OP_lit7: |
| 301 | case DW_OP_lit8: |
| 302 | case DW_OP_lit9: |
| 303 | case DW_OP_lit10: |
| 304 | case DW_OP_lit11: |
| 305 | case DW_OP_lit12: |
| 306 | case DW_OP_lit13: |
| 307 | case DW_OP_lit14: |
| 308 | case DW_OP_lit15: |
| 309 | case DW_OP_lit16: |
| 310 | case DW_OP_lit17: |
| 311 | case DW_OP_lit18: |
| 312 | case DW_OP_lit19: |
| 313 | case DW_OP_lit20: |
| 314 | case DW_OP_lit21: |
| 315 | case DW_OP_lit22: |
| 316 | case DW_OP_lit23: |
| 317 | case DW_OP_lit24: |
| 318 | case DW_OP_lit25: |
| 319 | case DW_OP_lit26: |
| 320 | case DW_OP_lit27: |
| 321 | case DW_OP_lit28: |
| 322 | case DW_OP_lit29: |
| 323 | case DW_OP_lit30: |
| 324 | case DW_OP_lit31: |
| 325 | result = op - DW_OP_lit0; |
| 326 | break; |
| 327 | |
| 328 | case DW_OP_addr: |
| 329 | result = dwarf2_read_address (op_ptr, op_end, ctx->addr_size); |
| 330 | op_ptr += ctx->addr_size; |
| 331 | break; |
| 332 | |
| 333 | case DW_OP_const1u: |
| 334 | result = extract_unsigned_integer (op_ptr, 1); |
| 335 | op_ptr += 1; |
| 336 | break; |
| 337 | case DW_OP_const1s: |
| 338 | result = extract_signed_integer (op_ptr, 1); |
| 339 | op_ptr += 1; |
| 340 | break; |
| 341 | case DW_OP_const2u: |
| 342 | result = extract_unsigned_integer (op_ptr, 2); |
| 343 | op_ptr += 2; |
| 344 | break; |
| 345 | case DW_OP_const2s: |
| 346 | result = extract_signed_integer (op_ptr, 2); |
| 347 | op_ptr += 2; |
| 348 | break; |
| 349 | case DW_OP_const4u: |
| 350 | result = extract_unsigned_integer (op_ptr, 4); |
| 351 | op_ptr += 4; |
| 352 | break; |
| 353 | case DW_OP_const4s: |
| 354 | result = extract_signed_integer (op_ptr, 4); |
| 355 | op_ptr += 4; |
| 356 | break; |
| 357 | case DW_OP_const8u: |
| 358 | result = extract_unsigned_integer (op_ptr, 8); |
| 359 | op_ptr += 8; |
| 360 | break; |
| 361 | case DW_OP_const8s: |
| 362 | result = extract_signed_integer (op_ptr, 8); |
| 363 | op_ptr += 8; |
| 364 | break; |
| 365 | case DW_OP_constu: |
| 366 | op_ptr = read_uleb128 (op_ptr, op_end, &uoffset); |
| 367 | result = uoffset; |
| 368 | break; |
| 369 | case DW_OP_consts: |
| 370 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 371 | result = offset; |
| 372 | break; |
| 373 | |
| 374 | /* The DW_OP_reg operations are required to occur alone in |
| 375 | location expressions. */ |
| 376 | case DW_OP_reg0: |
| 377 | case DW_OP_reg1: |
| 378 | case DW_OP_reg2: |
| 379 | case DW_OP_reg3: |
| 380 | case DW_OP_reg4: |
| 381 | case DW_OP_reg5: |
| 382 | case DW_OP_reg6: |
| 383 | case DW_OP_reg7: |
| 384 | case DW_OP_reg8: |
| 385 | case DW_OP_reg9: |
| 386 | case DW_OP_reg10: |
| 387 | case DW_OP_reg11: |
| 388 | case DW_OP_reg12: |
| 389 | case DW_OP_reg13: |
| 390 | case DW_OP_reg14: |
| 391 | case DW_OP_reg15: |
| 392 | case DW_OP_reg16: |
| 393 | case DW_OP_reg17: |
| 394 | case DW_OP_reg18: |
| 395 | case DW_OP_reg19: |
| 396 | case DW_OP_reg20: |
| 397 | case DW_OP_reg21: |
| 398 | case DW_OP_reg22: |
| 399 | case DW_OP_reg23: |
| 400 | case DW_OP_reg24: |
| 401 | case DW_OP_reg25: |
| 402 | case DW_OP_reg26: |
| 403 | case DW_OP_reg27: |
| 404 | case DW_OP_reg28: |
| 405 | case DW_OP_reg29: |
| 406 | case DW_OP_reg30: |
| 407 | case DW_OP_reg31: |
| 408 | if (op_ptr != op_end |
| 409 | && *op_ptr != DW_OP_piece |
| 410 | && *op_ptr != DW_OP_GNU_uninit) |
| 411 | error (_("DWARF-2 expression error: DW_OP_reg operations must be " |
| 412 | "used either alone or in conjuction with DW_OP_piece.")); |
| 413 | |
| 414 | result = op - DW_OP_reg0; |
| 415 | ctx->in_reg = 1; |
| 416 | |
| 417 | break; |
| 418 | |
| 419 | case DW_OP_regx: |
| 420 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 421 | if (op_ptr != op_end && *op_ptr != DW_OP_piece) |
| 422 | error (_("DWARF-2 expression error: DW_OP_reg operations must be " |
| 423 | "used either alone or in conjuction with DW_OP_piece.")); |
| 424 | |
| 425 | result = reg; |
| 426 | ctx->in_reg = 1; |
| 427 | break; |
| 428 | |
| 429 | case DW_OP_breg0: |
| 430 | case DW_OP_breg1: |
| 431 | case DW_OP_breg2: |
| 432 | case DW_OP_breg3: |
| 433 | case DW_OP_breg4: |
| 434 | case DW_OP_breg5: |
| 435 | case DW_OP_breg6: |
| 436 | case DW_OP_breg7: |
| 437 | case DW_OP_breg8: |
| 438 | case DW_OP_breg9: |
| 439 | case DW_OP_breg10: |
| 440 | case DW_OP_breg11: |
| 441 | case DW_OP_breg12: |
| 442 | case DW_OP_breg13: |
| 443 | case DW_OP_breg14: |
| 444 | case DW_OP_breg15: |
| 445 | case DW_OP_breg16: |
| 446 | case DW_OP_breg17: |
| 447 | case DW_OP_breg18: |
| 448 | case DW_OP_breg19: |
| 449 | case DW_OP_breg20: |
| 450 | case DW_OP_breg21: |
| 451 | case DW_OP_breg22: |
| 452 | case DW_OP_breg23: |
| 453 | case DW_OP_breg24: |
| 454 | case DW_OP_breg25: |
| 455 | case DW_OP_breg26: |
| 456 | case DW_OP_breg27: |
| 457 | case DW_OP_breg28: |
| 458 | case DW_OP_breg29: |
| 459 | case DW_OP_breg30: |
| 460 | case DW_OP_breg31: |
| 461 | { |
| 462 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 463 | result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0); |
| 464 | result += offset; |
| 465 | } |
| 466 | break; |
| 467 | case DW_OP_bregx: |
| 468 | { |
| 469 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 470 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 471 | result = (ctx->read_reg) (ctx->baton, reg); |
| 472 | result += offset; |
| 473 | } |
| 474 | break; |
| 475 | case DW_OP_fbreg: |
| 476 | { |
| 477 | gdb_byte *datastart; |
| 478 | size_t datalen; |
| 479 | unsigned int before_stack_len; |
| 480 | |
| 481 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); |
| 482 | /* Rather than create a whole new context, we simply |
| 483 | record the stack length before execution, then reset it |
| 484 | afterwards, effectively erasing whatever the recursive |
| 485 | call put there. */ |
| 486 | before_stack_len = ctx->stack_len; |
| 487 | /* FIXME: cagney/2003-03-26: This code should be using |
| 488 | get_frame_base_address(), and then implement a dwarf2 |
| 489 | specific this_base method. */ |
| 490 | (ctx->get_frame_base) (ctx->baton, &datastart, &datalen); |
| 491 | dwarf_expr_eval (ctx, datastart, datalen); |
| 492 | result = dwarf_expr_fetch (ctx, 0); |
| 493 | if (ctx->in_reg) |
| 494 | result = (ctx->read_reg) (ctx->baton, result); |
| 495 | result = result + offset; |
| 496 | ctx->stack_len = before_stack_len; |
| 497 | ctx->in_reg = 0; |
| 498 | } |
| 499 | break; |
| 500 | case DW_OP_dup: |
| 501 | result = dwarf_expr_fetch (ctx, 0); |
| 502 | break; |
| 503 | |
| 504 | case DW_OP_drop: |
| 505 | dwarf_expr_pop (ctx); |
| 506 | goto no_push; |
| 507 | |
| 508 | case DW_OP_pick: |
| 509 | offset = *op_ptr++; |
| 510 | result = dwarf_expr_fetch (ctx, offset); |
| 511 | break; |
| 512 | |
| 513 | case DW_OP_over: |
| 514 | result = dwarf_expr_fetch (ctx, 1); |
| 515 | break; |
| 516 | |
| 517 | case DW_OP_rot: |
| 518 | { |
| 519 | CORE_ADDR t1, t2, t3; |
| 520 | |
| 521 | if (ctx->stack_len < 3) |
| 522 | error (_("Not enough elements for DW_OP_rot. Need 3, have %d."), |
| 523 | ctx->stack_len); |
| 524 | t1 = ctx->stack[ctx->stack_len - 1]; |
| 525 | t2 = ctx->stack[ctx->stack_len - 2]; |
| 526 | t3 = ctx->stack[ctx->stack_len - 3]; |
| 527 | ctx->stack[ctx->stack_len - 1] = t2; |
| 528 | ctx->stack[ctx->stack_len - 2] = t3; |
| 529 | ctx->stack[ctx->stack_len - 3] = t1; |
| 530 | goto no_push; |
| 531 | } |
| 532 | |
| 533 | case DW_OP_deref: |
| 534 | case DW_OP_deref_size: |
| 535 | case DW_OP_abs: |
| 536 | case DW_OP_neg: |
| 537 | case DW_OP_not: |
| 538 | case DW_OP_plus_uconst: |
| 539 | /* Unary operations. */ |
| 540 | result = dwarf_expr_fetch (ctx, 0); |
| 541 | dwarf_expr_pop (ctx); |
| 542 | |
| 543 | switch (op) |
| 544 | { |
| 545 | case DW_OP_deref: |
| 546 | { |
| 547 | gdb_byte *buf = alloca (ctx->addr_size); |
| 548 | (ctx->read_mem) (ctx->baton, buf, result, ctx->addr_size); |
| 549 | result = dwarf2_read_address (buf, buf + ctx->addr_size, |
| 550 | ctx->addr_size); |
| 551 | } |
| 552 | break; |
| 553 | |
| 554 | case DW_OP_deref_size: |
| 555 | { |
| 556 | int addr_size = *op_ptr++; |
| 557 | gdb_byte *buf = alloca (addr_size); |
| 558 | (ctx->read_mem) (ctx->baton, buf, result, addr_size); |
| 559 | result = dwarf2_read_address (buf, buf + addr_size, |
| 560 | addr_size); |
| 561 | } |
| 562 | break; |
| 563 | |
| 564 | case DW_OP_abs: |
| 565 | if ((signed int) result < 0) |
| 566 | result = -result; |
| 567 | break; |
| 568 | case DW_OP_neg: |
| 569 | result = -result; |
| 570 | break; |
| 571 | case DW_OP_not: |
| 572 | result = ~result; |
| 573 | break; |
| 574 | case DW_OP_plus_uconst: |
| 575 | op_ptr = read_uleb128 (op_ptr, op_end, ®); |
| 576 | result += reg; |
| 577 | break; |
| 578 | } |
| 579 | break; |
| 580 | |
| 581 | case DW_OP_and: |
| 582 | case DW_OP_div: |
| 583 | case DW_OP_minus: |
| 584 | case DW_OP_mod: |
| 585 | case DW_OP_mul: |
| 586 | case DW_OP_or: |
| 587 | case DW_OP_plus: |
| 588 | case DW_OP_shl: |
| 589 | case DW_OP_shr: |
| 590 | case DW_OP_shra: |
| 591 | case DW_OP_xor: |
| 592 | case DW_OP_le: |
| 593 | case DW_OP_ge: |
| 594 | case DW_OP_eq: |
| 595 | case DW_OP_lt: |
| 596 | case DW_OP_gt: |
| 597 | case DW_OP_ne: |
| 598 | { |
| 599 | /* Binary operations. Use the value engine to do computations in |
| 600 | the right width. */ |
| 601 | CORE_ADDR first, second; |
| 602 | enum exp_opcode binop; |
| 603 | struct value *val1, *val2; |
| 604 | |
| 605 | second = dwarf_expr_fetch (ctx, 0); |
| 606 | dwarf_expr_pop (ctx); |
| 607 | |
| 608 | first = dwarf_expr_fetch (ctx, 0); |
| 609 | dwarf_expr_pop (ctx); |
| 610 | |
| 611 | val1 = value_from_longest |
| 612 | (unsigned_address_type (ctx->addr_size), first); |
| 613 | val2 = value_from_longest |
| 614 | (unsigned_address_type (ctx->addr_size), second); |
| 615 | |
| 616 | switch (op) |
| 617 | { |
| 618 | case DW_OP_and: |
| 619 | binop = BINOP_BITWISE_AND; |
| 620 | break; |
| 621 | case DW_OP_div: |
| 622 | binop = BINOP_DIV; |
| 623 | break; |
| 624 | case DW_OP_minus: |
| 625 | binop = BINOP_SUB; |
| 626 | break; |
| 627 | case DW_OP_mod: |
| 628 | binop = BINOP_MOD; |
| 629 | break; |
| 630 | case DW_OP_mul: |
| 631 | binop = BINOP_MUL; |
| 632 | break; |
| 633 | case DW_OP_or: |
| 634 | binop = BINOP_BITWISE_IOR; |
| 635 | break; |
| 636 | case DW_OP_plus: |
| 637 | binop = BINOP_ADD; |
| 638 | break; |
| 639 | case DW_OP_shl: |
| 640 | binop = BINOP_LSH; |
| 641 | break; |
| 642 | case DW_OP_shr: |
| 643 | binop = BINOP_RSH; |
| 644 | break; |
| 645 | case DW_OP_shra: |
| 646 | binop = BINOP_RSH; |
| 647 | val1 = value_from_longest |
| 648 | (signed_address_type (ctx->addr_size), first); |
| 649 | break; |
| 650 | case DW_OP_xor: |
| 651 | binop = BINOP_BITWISE_XOR; |
| 652 | break; |
| 653 | case DW_OP_le: |
| 654 | binop = BINOP_LEQ; |
| 655 | break; |
| 656 | case DW_OP_ge: |
| 657 | binop = BINOP_GEQ; |
| 658 | break; |
| 659 | case DW_OP_eq: |
| 660 | binop = BINOP_EQUAL; |
| 661 | break; |
| 662 | case DW_OP_lt: |
| 663 | binop = BINOP_LESS; |
| 664 | break; |
| 665 | case DW_OP_gt: |
| 666 | binop = BINOP_GTR; |
| 667 | break; |
| 668 | case DW_OP_ne: |
| 669 | binop = BINOP_NOTEQUAL; |
| 670 | break; |
| 671 | default: |
| 672 | internal_error (__FILE__, __LINE__, |
| 673 | _("Can't be reached.")); |
| 674 | } |
| 675 | result = value_as_long (value_binop (val1, val2, binop)); |
| 676 | } |
| 677 | break; |
| 678 | |
| 679 | case DW_OP_GNU_push_tls_address: |
| 680 | /* Variable is at a constant offset in the thread-local |
| 681 | storage block into the objfile for the current thread and |
| 682 | the dynamic linker module containing this expression. Here |
| 683 | we return returns the offset from that base. The top of the |
| 684 | stack has the offset from the beginning of the thread |
| 685 | control block at which the variable is located. Nothing |
| 686 | should follow this operator, so the top of stack would be |
| 687 | returned. */ |
| 688 | result = dwarf_expr_fetch (ctx, 0); |
| 689 | dwarf_expr_pop (ctx); |
| 690 | result = (ctx->get_tls_address) (ctx->baton, result); |
| 691 | break; |
| 692 | |
| 693 | case DW_OP_skip: |
| 694 | offset = extract_signed_integer (op_ptr, 2); |
| 695 | op_ptr += 2; |
| 696 | op_ptr += offset; |
| 697 | goto no_push; |
| 698 | |
| 699 | case DW_OP_bra: |
| 700 | offset = extract_signed_integer (op_ptr, 2); |
| 701 | op_ptr += 2; |
| 702 | if (dwarf_expr_fetch (ctx, 0) != 0) |
| 703 | op_ptr += offset; |
| 704 | dwarf_expr_pop (ctx); |
| 705 | goto no_push; |
| 706 | |
| 707 | case DW_OP_nop: |
| 708 | goto no_push; |
| 709 | |
| 710 | case DW_OP_piece: |
| 711 | { |
| 712 | ULONGEST size; |
| 713 | CORE_ADDR addr_or_regnum; |
| 714 | |
| 715 | /* Record the piece. */ |
| 716 | op_ptr = read_uleb128 (op_ptr, op_end, &size); |
| 717 | addr_or_regnum = dwarf_expr_fetch (ctx, 0); |
| 718 | add_piece (ctx, ctx->in_reg, addr_or_regnum, size); |
| 719 | |
| 720 | /* Pop off the address/regnum, and clear the in_reg flag. */ |
| 721 | dwarf_expr_pop (ctx); |
| 722 | ctx->in_reg = 0; |
| 723 | } |
| 724 | goto no_push; |
| 725 | |
| 726 | case DW_OP_GNU_uninit: |
| 727 | if (op_ptr != op_end) |
| 728 | error (_("DWARF-2 expression error: DW_OP_GNU_unint must always " |
| 729 | "be the very last op.")); |
| 730 | |
| 731 | ctx->initialized = 0; |
| 732 | goto no_push; |
| 733 | |
| 734 | default: |
| 735 | error (_("Unhandled dwarf expression opcode 0x%x"), op); |
| 736 | } |
| 737 | |
| 738 | /* Most things push a result value. */ |
| 739 | dwarf_expr_push (ctx, result); |
| 740 | no_push:; |
| 741 | } |
| 742 | } |