| 1 | /* DWARF 2 Expression Evaluator. |
| 2 | |
| 3 | Copyright (C) 2001-2016 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by Daniel Berlin (dan@dberlin.org) |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "symtab.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "value.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "dwarf2.h" |
| 28 | #include "dwarf2expr.h" |
| 29 | #include "dwarf2loc.h" |
| 30 | |
| 31 | /* Cookie for gdbarch data. */ |
| 32 | |
| 33 | static struct gdbarch_data *dwarf_arch_cookie; |
| 34 | |
| 35 | /* This holds gdbarch-specific types used by the DWARF expression |
| 36 | evaluator. See comments in execute_stack_op. */ |
| 37 | |
| 38 | struct dwarf_gdbarch_types |
| 39 | { |
| 40 | struct type *dw_types[3]; |
| 41 | }; |
| 42 | |
| 43 | /* Allocate and fill in dwarf_gdbarch_types for an arch. */ |
| 44 | |
| 45 | static void * |
| 46 | dwarf_gdbarch_types_init (struct gdbarch *gdbarch) |
| 47 | { |
| 48 | struct dwarf_gdbarch_types *types |
| 49 | = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct dwarf_gdbarch_types); |
| 50 | |
| 51 | /* The types themselves are lazily initialized. */ |
| 52 | |
| 53 | return types; |
| 54 | } |
| 55 | |
| 56 | /* Return the type used for DWARF operations where the type is |
| 57 | unspecified in the DWARF spec. Only certain sizes are |
| 58 | supported. */ |
| 59 | |
| 60 | struct type * |
| 61 | dwarf_expr_context::address_type () const |
| 62 | { |
| 63 | struct dwarf_gdbarch_types *types |
| 64 | = (struct dwarf_gdbarch_types *) gdbarch_data (this->gdbarch, |
| 65 | dwarf_arch_cookie); |
| 66 | int ndx; |
| 67 | |
| 68 | if (this->addr_size == 2) |
| 69 | ndx = 0; |
| 70 | else if (this->addr_size == 4) |
| 71 | ndx = 1; |
| 72 | else if (this->addr_size == 8) |
| 73 | ndx = 2; |
| 74 | else |
| 75 | error (_("Unsupported address size in DWARF expressions: %d bits"), |
| 76 | 8 * this->addr_size); |
| 77 | |
| 78 | if (types->dw_types[ndx] == NULL) |
| 79 | types->dw_types[ndx] |
| 80 | = arch_integer_type (this->gdbarch, |
| 81 | 8 * this->addr_size, |
| 82 | 0, "<signed DWARF address type>"); |
| 83 | |
| 84 | return types->dw_types[ndx]; |
| 85 | } |
| 86 | |
| 87 | /* Create a new context for the expression evaluator. */ |
| 88 | |
| 89 | dwarf_expr_context::dwarf_expr_context () |
| 90 | : stack (NULL), |
| 91 | stack_len (0), |
| 92 | stack_allocated (10), |
| 93 | gdbarch (NULL), |
| 94 | addr_size (0), |
| 95 | ref_addr_size (0), |
| 96 | offset (0), |
| 97 | recursion_depth (0), |
| 98 | max_recursion_depth (0x100), |
| 99 | location (DWARF_VALUE_MEMORY), |
| 100 | len (0), |
| 101 | data (NULL), |
| 102 | initialized (0), |
| 103 | num_pieces (0), |
| 104 | pieces (NULL) |
| 105 | { |
| 106 | this->stack = XNEWVEC (struct dwarf_stack_value, this->stack_allocated); |
| 107 | } |
| 108 | |
| 109 | /* Clean up a dwarf_expr_context. */ |
| 110 | |
| 111 | dwarf_expr_context::~dwarf_expr_context () |
| 112 | { |
| 113 | xfree (this->stack); |
| 114 | xfree (this->pieces); |
| 115 | } |
| 116 | |
| 117 | /* Expand the memory allocated stack to contain at least |
| 118 | NEED more elements than are currently used. */ |
| 119 | |
| 120 | void |
| 121 | dwarf_expr_context::grow_stack (size_t need) |
| 122 | { |
| 123 | if (this->stack_len + need > this->stack_allocated) |
| 124 | { |
| 125 | size_t newlen = this->stack_len + need + 10; |
| 126 | |
| 127 | this->stack = XRESIZEVEC (struct dwarf_stack_value, this->stack, newlen); |
| 128 | this->stack_allocated = newlen; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | /* Push VALUE onto the stack. */ |
| 133 | |
| 134 | void |
| 135 | dwarf_expr_context::push (struct value *value, int in_stack_memory) |
| 136 | { |
| 137 | struct dwarf_stack_value *v; |
| 138 | |
| 139 | grow_stack (1); |
| 140 | v = &this->stack[this->stack_len++]; |
| 141 | v->value = value; |
| 142 | v->in_stack_memory = in_stack_memory; |
| 143 | } |
| 144 | |
| 145 | /* Push VALUE onto the stack. */ |
| 146 | |
| 147 | void |
| 148 | dwarf_expr_context::push_address (CORE_ADDR value, int in_stack_memory) |
| 149 | { |
| 150 | push (value_from_ulongest (address_type (), value), in_stack_memory); |
| 151 | } |
| 152 | |
| 153 | /* Pop the top item off of the stack. */ |
| 154 | |
| 155 | void |
| 156 | dwarf_expr_context::pop () |
| 157 | { |
| 158 | if (this->stack_len <= 0) |
| 159 | error (_("dwarf expression stack underflow")); |
| 160 | this->stack_len--; |
| 161 | } |
| 162 | |
| 163 | /* Retrieve the N'th item on the stack. */ |
| 164 | |
| 165 | struct value * |
| 166 | dwarf_expr_context::fetch (int n) |
| 167 | { |
| 168 | if (this->stack_len <= n) |
| 169 | error (_("Asked for position %d of stack, " |
| 170 | "stack only has %d elements on it."), |
| 171 | n, this->stack_len); |
| 172 | return this->stack[this->stack_len - (1 + n)].value; |
| 173 | } |
| 174 | |
| 175 | /* Require that TYPE be an integral type; throw an exception if not. */ |
| 176 | |
| 177 | static void |
| 178 | dwarf_require_integral (struct type *type) |
| 179 | { |
| 180 | if (TYPE_CODE (type) != TYPE_CODE_INT |
| 181 | && TYPE_CODE (type) != TYPE_CODE_CHAR |
| 182 | && TYPE_CODE (type) != TYPE_CODE_BOOL) |
| 183 | error (_("integral type expected in DWARF expression")); |
| 184 | } |
| 185 | |
| 186 | /* Return the unsigned form of TYPE. TYPE is necessarily an integral |
| 187 | type. */ |
| 188 | |
| 189 | static struct type * |
| 190 | get_unsigned_type (struct gdbarch *gdbarch, struct type *type) |
| 191 | { |
| 192 | switch (TYPE_LENGTH (type)) |
| 193 | { |
| 194 | case 1: |
| 195 | return builtin_type (gdbarch)->builtin_uint8; |
| 196 | case 2: |
| 197 | return builtin_type (gdbarch)->builtin_uint16; |
| 198 | case 4: |
| 199 | return builtin_type (gdbarch)->builtin_uint32; |
| 200 | case 8: |
| 201 | return builtin_type (gdbarch)->builtin_uint64; |
| 202 | default: |
| 203 | error (_("no unsigned variant found for type, while evaluating " |
| 204 | "DWARF expression")); |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /* Return the signed form of TYPE. TYPE is necessarily an integral |
| 209 | type. */ |
| 210 | |
| 211 | static struct type * |
| 212 | get_signed_type (struct gdbarch *gdbarch, struct type *type) |
| 213 | { |
| 214 | switch (TYPE_LENGTH (type)) |
| 215 | { |
| 216 | case 1: |
| 217 | return builtin_type (gdbarch)->builtin_int8; |
| 218 | case 2: |
| 219 | return builtin_type (gdbarch)->builtin_int16; |
| 220 | case 4: |
| 221 | return builtin_type (gdbarch)->builtin_int32; |
| 222 | case 8: |
| 223 | return builtin_type (gdbarch)->builtin_int64; |
| 224 | default: |
| 225 | error (_("no signed variant found for type, while evaluating " |
| 226 | "DWARF expression")); |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | /* Retrieve the N'th item on the stack, converted to an address. */ |
| 231 | |
| 232 | CORE_ADDR |
| 233 | dwarf_expr_context::fetch_address (int n) |
| 234 | { |
| 235 | struct value *result_val = fetch (n); |
| 236 | enum bfd_endian byte_order = gdbarch_byte_order (this->gdbarch); |
| 237 | ULONGEST result; |
| 238 | |
| 239 | dwarf_require_integral (value_type (result_val)); |
| 240 | result = extract_unsigned_integer (value_contents (result_val), |
| 241 | TYPE_LENGTH (value_type (result_val)), |
| 242 | byte_order); |
| 243 | |
| 244 | /* For most architectures, calling extract_unsigned_integer() alone |
| 245 | is sufficient for extracting an address. However, some |
| 246 | architectures (e.g. MIPS) use signed addresses and using |
| 247 | extract_unsigned_integer() will not produce a correct |
| 248 | result. Make sure we invoke gdbarch_integer_to_address() |
| 249 | for those architectures which require it. */ |
| 250 | if (gdbarch_integer_to_address_p (this->gdbarch)) |
| 251 | { |
| 252 | gdb_byte *buf = (gdb_byte *) alloca (this->addr_size); |
| 253 | struct type *int_type = get_unsigned_type (this->gdbarch, |
| 254 | value_type (result_val)); |
| 255 | |
| 256 | store_unsigned_integer (buf, this->addr_size, byte_order, result); |
| 257 | return gdbarch_integer_to_address (this->gdbarch, int_type, buf); |
| 258 | } |
| 259 | |
| 260 | return (CORE_ADDR) result; |
| 261 | } |
| 262 | |
| 263 | /* Retrieve the in_stack_memory flag of the N'th item on the stack. */ |
| 264 | |
| 265 | int |
| 266 | dwarf_expr_context::fetch_in_stack_memory (int n) |
| 267 | { |
| 268 | if (this->stack_len <= n) |
| 269 | error (_("Asked for position %d of stack, " |
| 270 | "stack only has %d elements on it."), |
| 271 | n, this->stack_len); |
| 272 | return this->stack[this->stack_len - (1 + n)].in_stack_memory; |
| 273 | } |
| 274 | |
| 275 | /* Return true if the expression stack is empty. */ |
| 276 | |
| 277 | int |
| 278 | dwarf_expr_context::stack_empty_p () const |
| 279 | { |
| 280 | return this->stack_len == 0; |
| 281 | } |
| 282 | |
| 283 | /* Add a new piece to the dwarf_expr_context's piece list. */ |
| 284 | void |
| 285 | dwarf_expr_context::add_piece (ULONGEST size, ULONGEST offset) |
| 286 | { |
| 287 | struct dwarf_expr_piece *p; |
| 288 | |
| 289 | this->num_pieces++; |
| 290 | |
| 291 | this->pieces |
| 292 | = XRESIZEVEC (struct dwarf_expr_piece, this->pieces, this->num_pieces); |
| 293 | |
| 294 | p = &this->pieces[this->num_pieces - 1]; |
| 295 | p->location = this->location; |
| 296 | p->size = size; |
| 297 | p->offset = offset; |
| 298 | |
| 299 | if (p->location == DWARF_VALUE_LITERAL) |
| 300 | { |
| 301 | p->v.literal.data = this->data; |
| 302 | p->v.literal.length = this->len; |
| 303 | } |
| 304 | else if (stack_empty_p ()) |
| 305 | { |
| 306 | p->location = DWARF_VALUE_OPTIMIZED_OUT; |
| 307 | /* Also reset the context's location, for our callers. This is |
| 308 | a somewhat strange approach, but this lets us avoid setting |
| 309 | the location to DWARF_VALUE_MEMORY in all the individual |
| 310 | cases in the evaluator. */ |
| 311 | this->location = DWARF_VALUE_OPTIMIZED_OUT; |
| 312 | } |
| 313 | else if (p->location == DWARF_VALUE_MEMORY) |
| 314 | { |
| 315 | p->v.mem.addr = fetch_address (0); |
| 316 | p->v.mem.in_stack_memory = fetch_in_stack_memory (0); |
| 317 | } |
| 318 | else if (p->location == DWARF_VALUE_IMPLICIT_POINTER) |
| 319 | { |
| 320 | p->v.ptr.die.sect_off = this->len; |
| 321 | p->v.ptr.offset = value_as_long (fetch (0)); |
| 322 | } |
| 323 | else if (p->location == DWARF_VALUE_REGISTER) |
| 324 | p->v.regno = value_as_long (fetch (0)); |
| 325 | else |
| 326 | { |
| 327 | p->v.value = fetch (0); |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | /* Evaluate the expression at ADDR (LEN bytes long). */ |
| 332 | |
| 333 | void |
| 334 | dwarf_expr_context::eval (const gdb_byte *addr, size_t len) |
| 335 | { |
| 336 | int old_recursion_depth = this->recursion_depth; |
| 337 | |
| 338 | execute_stack_op (addr, addr + len); |
| 339 | |
| 340 | /* RECURSION_DEPTH becomes invalid if an exception was thrown here. */ |
| 341 | |
| 342 | gdb_assert (this->recursion_depth == old_recursion_depth); |
| 343 | } |
| 344 | |
| 345 | /* Helper to read a uleb128 value or throw an error. */ |
| 346 | |
| 347 | const gdb_byte * |
| 348 | safe_read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end, |
| 349 | uint64_t *r) |
| 350 | { |
| 351 | buf = gdb_read_uleb128 (buf, buf_end, r); |
| 352 | if (buf == NULL) |
| 353 | error (_("DWARF expression error: ran off end of buffer reading uleb128 value")); |
| 354 | return buf; |
| 355 | } |
| 356 | |
| 357 | /* Helper to read a sleb128 value or throw an error. */ |
| 358 | |
| 359 | const gdb_byte * |
| 360 | safe_read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end, |
| 361 | int64_t *r) |
| 362 | { |
| 363 | buf = gdb_read_sleb128 (buf, buf_end, r); |
| 364 | if (buf == NULL) |
| 365 | error (_("DWARF expression error: ran off end of buffer reading sleb128 value")); |
| 366 | return buf; |
| 367 | } |
| 368 | |
| 369 | const gdb_byte * |
| 370 | safe_skip_leb128 (const gdb_byte *buf, const gdb_byte *buf_end) |
| 371 | { |
| 372 | buf = gdb_skip_leb128 (buf, buf_end); |
| 373 | if (buf == NULL) |
| 374 | error (_("DWARF expression error: ran off end of buffer reading leb128 value")); |
| 375 | return buf; |
| 376 | } |
| 377 | \f |
| 378 | |
| 379 | /* Check that the current operator is either at the end of an |
| 380 | expression, or that it is followed by a composition operator or by |
| 381 | DW_OP_GNU_uninit (which should terminate the expression). */ |
| 382 | |
| 383 | void |
| 384 | dwarf_expr_require_composition (const gdb_byte *op_ptr, const gdb_byte *op_end, |
| 385 | const char *op_name) |
| 386 | { |
| 387 | if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece |
| 388 | && *op_ptr != DW_OP_GNU_uninit) |
| 389 | error (_("DWARF-2 expression error: `%s' operations must be " |
| 390 | "used either alone or in conjunction with DW_OP_piece " |
| 391 | "or DW_OP_bit_piece."), |
| 392 | op_name); |
| 393 | } |
| 394 | |
| 395 | /* Return true iff the types T1 and T2 are "the same". This only does |
| 396 | checks that might reasonably be needed to compare DWARF base |
| 397 | types. */ |
| 398 | |
| 399 | static int |
| 400 | base_types_equal_p (struct type *t1, struct type *t2) |
| 401 | { |
| 402 | if (TYPE_CODE (t1) != TYPE_CODE (t2)) |
| 403 | return 0; |
| 404 | if (TYPE_UNSIGNED (t1) != TYPE_UNSIGNED (t2)) |
| 405 | return 0; |
| 406 | return TYPE_LENGTH (t1) == TYPE_LENGTH (t2); |
| 407 | } |
| 408 | |
| 409 | /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_reg* return the |
| 410 | DWARF register number. Otherwise return -1. */ |
| 411 | |
| 412 | int |
| 413 | dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end) |
| 414 | { |
| 415 | uint64_t dwarf_reg; |
| 416 | |
| 417 | if (buf_end <= buf) |
| 418 | return -1; |
| 419 | if (*buf >= DW_OP_reg0 && *buf <= DW_OP_reg31) |
| 420 | { |
| 421 | if (buf_end - buf != 1) |
| 422 | return -1; |
| 423 | return *buf - DW_OP_reg0; |
| 424 | } |
| 425 | |
| 426 | if (*buf == DW_OP_GNU_regval_type) |
| 427 | { |
| 428 | buf++; |
| 429 | buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg); |
| 430 | if (buf == NULL) |
| 431 | return -1; |
| 432 | buf = gdb_skip_leb128 (buf, buf_end); |
| 433 | if (buf == NULL) |
| 434 | return -1; |
| 435 | } |
| 436 | else if (*buf == DW_OP_regx) |
| 437 | { |
| 438 | buf++; |
| 439 | buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg); |
| 440 | if (buf == NULL) |
| 441 | return -1; |
| 442 | } |
| 443 | else |
| 444 | return -1; |
| 445 | if (buf != buf_end || (int) dwarf_reg != dwarf_reg) |
| 446 | return -1; |
| 447 | return dwarf_reg; |
| 448 | } |
| 449 | |
| 450 | /* If <BUF..BUF_END] contains DW_FORM_block* with just DW_OP_breg*(0) and |
| 451 | DW_OP_deref* return the DWARF register number. Otherwise return -1. |
| 452 | DEREF_SIZE_RETURN contains -1 for DW_OP_deref; otherwise it contains the |
| 453 | size from DW_OP_deref_size. */ |
| 454 | |
| 455 | int |
| 456 | dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf, const gdb_byte *buf_end, |
| 457 | CORE_ADDR *deref_size_return) |
| 458 | { |
| 459 | uint64_t dwarf_reg; |
| 460 | int64_t offset; |
| 461 | |
| 462 | if (buf_end <= buf) |
| 463 | return -1; |
| 464 | |
| 465 | if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31) |
| 466 | { |
| 467 | dwarf_reg = *buf - DW_OP_breg0; |
| 468 | buf++; |
| 469 | if (buf >= buf_end) |
| 470 | return -1; |
| 471 | } |
| 472 | else if (*buf == DW_OP_bregx) |
| 473 | { |
| 474 | buf++; |
| 475 | buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg); |
| 476 | if (buf == NULL) |
| 477 | return -1; |
| 478 | if ((int) dwarf_reg != dwarf_reg) |
| 479 | return -1; |
| 480 | } |
| 481 | else |
| 482 | return -1; |
| 483 | |
| 484 | buf = gdb_read_sleb128 (buf, buf_end, &offset); |
| 485 | if (buf == NULL) |
| 486 | return -1; |
| 487 | if (offset != 0) |
| 488 | return -1; |
| 489 | |
| 490 | if (*buf == DW_OP_deref) |
| 491 | { |
| 492 | buf++; |
| 493 | *deref_size_return = -1; |
| 494 | } |
| 495 | else if (*buf == DW_OP_deref_size) |
| 496 | { |
| 497 | buf++; |
| 498 | if (buf >= buf_end) |
| 499 | return -1; |
| 500 | *deref_size_return = *buf++; |
| 501 | } |
| 502 | else |
| 503 | return -1; |
| 504 | |
| 505 | if (buf != buf_end) |
| 506 | return -1; |
| 507 | |
| 508 | return dwarf_reg; |
| 509 | } |
| 510 | |
| 511 | /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_fbreg(X) fill |
| 512 | in FB_OFFSET_RETURN with the X offset and return 1. Otherwise return 0. */ |
| 513 | |
| 514 | int |
| 515 | dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end, |
| 516 | CORE_ADDR *fb_offset_return) |
| 517 | { |
| 518 | int64_t fb_offset; |
| 519 | |
| 520 | if (buf_end <= buf) |
| 521 | return 0; |
| 522 | |
| 523 | if (*buf != DW_OP_fbreg) |
| 524 | return 0; |
| 525 | buf++; |
| 526 | |
| 527 | buf = gdb_read_sleb128 (buf, buf_end, &fb_offset); |
| 528 | if (buf == NULL) |
| 529 | return 0; |
| 530 | *fb_offset_return = fb_offset; |
| 531 | if (buf != buf_end || fb_offset != (LONGEST) *fb_offset_return) |
| 532 | return 0; |
| 533 | |
| 534 | return 1; |
| 535 | } |
| 536 | |
| 537 | /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_bregSP(X) fill |
| 538 | in SP_OFFSET_RETURN with the X offset and return 1. Otherwise return 0. |
| 539 | The matched SP register number depends on GDBARCH. */ |
| 540 | |
| 541 | int |
| 542 | dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf, |
| 543 | const gdb_byte *buf_end, CORE_ADDR *sp_offset_return) |
| 544 | { |
| 545 | uint64_t dwarf_reg; |
| 546 | int64_t sp_offset; |
| 547 | |
| 548 | if (buf_end <= buf) |
| 549 | return 0; |
| 550 | if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31) |
| 551 | { |
| 552 | dwarf_reg = *buf - DW_OP_breg0; |
| 553 | buf++; |
| 554 | } |
| 555 | else |
| 556 | { |
| 557 | if (*buf != DW_OP_bregx) |
| 558 | return 0; |
| 559 | buf++; |
| 560 | buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg); |
| 561 | if (buf == NULL) |
| 562 | return 0; |
| 563 | } |
| 564 | |
| 565 | if (dwarf_reg_to_regnum (gdbarch, dwarf_reg) |
| 566 | != gdbarch_sp_regnum (gdbarch)) |
| 567 | return 0; |
| 568 | |
| 569 | buf = gdb_read_sleb128 (buf, buf_end, &sp_offset); |
| 570 | if (buf == NULL) |
| 571 | return 0; |
| 572 | *sp_offset_return = sp_offset; |
| 573 | if (buf != buf_end || sp_offset != (LONGEST) *sp_offset_return) |
| 574 | return 0; |
| 575 | |
| 576 | return 1; |
| 577 | } |
| 578 | |
| 579 | /* The engine for the expression evaluator. Using the context in this |
| 580 | object, evaluate the expression between OP_PTR and OP_END. */ |
| 581 | |
| 582 | void |
| 583 | dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr, |
| 584 | const gdb_byte *op_end) |
| 585 | { |
| 586 | enum bfd_endian byte_order = gdbarch_byte_order (this->gdbarch); |
| 587 | /* Old-style "untyped" DWARF values need special treatment in a |
| 588 | couple of places, specifically DW_OP_mod and DW_OP_shr. We need |
| 589 | a special type for these values so we can distinguish them from |
| 590 | values that have an explicit type, because explicitly-typed |
| 591 | values do not need special treatment. This special type must be |
| 592 | different (in the `==' sense) from any base type coming from the |
| 593 | CU. */ |
| 594 | struct type *address_type = this->address_type (); |
| 595 | |
| 596 | this->location = DWARF_VALUE_MEMORY; |
| 597 | this->initialized = 1; /* Default is initialized. */ |
| 598 | |
| 599 | if (this->recursion_depth > this->max_recursion_depth) |
| 600 | error (_("DWARF-2 expression error: Loop detected (%d)."), |
| 601 | this->recursion_depth); |
| 602 | this->recursion_depth++; |
| 603 | |
| 604 | while (op_ptr < op_end) |
| 605 | { |
| 606 | enum dwarf_location_atom op = (enum dwarf_location_atom) *op_ptr++; |
| 607 | ULONGEST result; |
| 608 | /* Assume the value is not in stack memory. |
| 609 | Code that knows otherwise sets this to 1. |
| 610 | Some arithmetic on stack addresses can probably be assumed to still |
| 611 | be a stack address, but we skip this complication for now. |
| 612 | This is just an optimization, so it's always ok to punt |
| 613 | and leave this as 0. */ |
| 614 | int in_stack_memory = 0; |
| 615 | uint64_t uoffset, reg; |
| 616 | int64_t offset; |
| 617 | struct value *result_val = NULL; |
| 618 | |
| 619 | /* The DWARF expression might have a bug causing an infinite |
| 620 | loop. In that case, quitting is the only way out. */ |
| 621 | QUIT; |
| 622 | |
| 623 | switch (op) |
| 624 | { |
| 625 | case DW_OP_lit0: |
| 626 | case DW_OP_lit1: |
| 627 | case DW_OP_lit2: |
| 628 | case DW_OP_lit3: |
| 629 | case DW_OP_lit4: |
| 630 | case DW_OP_lit5: |
| 631 | case DW_OP_lit6: |
| 632 | case DW_OP_lit7: |
| 633 | case DW_OP_lit8: |
| 634 | case DW_OP_lit9: |
| 635 | case DW_OP_lit10: |
| 636 | case DW_OP_lit11: |
| 637 | case DW_OP_lit12: |
| 638 | case DW_OP_lit13: |
| 639 | case DW_OP_lit14: |
| 640 | case DW_OP_lit15: |
| 641 | case DW_OP_lit16: |
| 642 | case DW_OP_lit17: |
| 643 | case DW_OP_lit18: |
| 644 | case DW_OP_lit19: |
| 645 | case DW_OP_lit20: |
| 646 | case DW_OP_lit21: |
| 647 | case DW_OP_lit22: |
| 648 | case DW_OP_lit23: |
| 649 | case DW_OP_lit24: |
| 650 | case DW_OP_lit25: |
| 651 | case DW_OP_lit26: |
| 652 | case DW_OP_lit27: |
| 653 | case DW_OP_lit28: |
| 654 | case DW_OP_lit29: |
| 655 | case DW_OP_lit30: |
| 656 | case DW_OP_lit31: |
| 657 | result = op - DW_OP_lit0; |
| 658 | result_val = value_from_ulongest (address_type, result); |
| 659 | break; |
| 660 | |
| 661 | case DW_OP_addr: |
| 662 | result = extract_unsigned_integer (op_ptr, |
| 663 | this->addr_size, byte_order); |
| 664 | op_ptr += this->addr_size; |
| 665 | /* Some versions of GCC emit DW_OP_addr before |
| 666 | DW_OP_GNU_push_tls_address. In this case the value is an |
| 667 | index, not an address. We don't support things like |
| 668 | branching between the address and the TLS op. */ |
| 669 | if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address) |
| 670 | result += this->offset; |
| 671 | result_val = value_from_ulongest (address_type, result); |
| 672 | break; |
| 673 | |
| 674 | case DW_OP_GNU_addr_index: |
| 675 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 676 | result = this->get_addr_index (uoffset); |
| 677 | result += this->offset; |
| 678 | result_val = value_from_ulongest (address_type, result); |
| 679 | break; |
| 680 | case DW_OP_GNU_const_index: |
| 681 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 682 | result = this->get_addr_index (uoffset); |
| 683 | result_val = value_from_ulongest (address_type, result); |
| 684 | break; |
| 685 | |
| 686 | case DW_OP_const1u: |
| 687 | result = extract_unsigned_integer (op_ptr, 1, byte_order); |
| 688 | result_val = value_from_ulongest (address_type, result); |
| 689 | op_ptr += 1; |
| 690 | break; |
| 691 | case DW_OP_const1s: |
| 692 | result = extract_signed_integer (op_ptr, 1, byte_order); |
| 693 | result_val = value_from_ulongest (address_type, result); |
| 694 | op_ptr += 1; |
| 695 | break; |
| 696 | case DW_OP_const2u: |
| 697 | result = extract_unsigned_integer (op_ptr, 2, byte_order); |
| 698 | result_val = value_from_ulongest (address_type, result); |
| 699 | op_ptr += 2; |
| 700 | break; |
| 701 | case DW_OP_const2s: |
| 702 | result = extract_signed_integer (op_ptr, 2, byte_order); |
| 703 | result_val = value_from_ulongest (address_type, result); |
| 704 | op_ptr += 2; |
| 705 | break; |
| 706 | case DW_OP_const4u: |
| 707 | result = extract_unsigned_integer (op_ptr, 4, byte_order); |
| 708 | result_val = value_from_ulongest (address_type, result); |
| 709 | op_ptr += 4; |
| 710 | break; |
| 711 | case DW_OP_const4s: |
| 712 | result = extract_signed_integer (op_ptr, 4, byte_order); |
| 713 | result_val = value_from_ulongest (address_type, result); |
| 714 | op_ptr += 4; |
| 715 | break; |
| 716 | case DW_OP_const8u: |
| 717 | result = extract_unsigned_integer (op_ptr, 8, byte_order); |
| 718 | result_val = value_from_ulongest (address_type, result); |
| 719 | op_ptr += 8; |
| 720 | break; |
| 721 | case DW_OP_const8s: |
| 722 | result = extract_signed_integer (op_ptr, 8, byte_order); |
| 723 | result_val = value_from_ulongest (address_type, result); |
| 724 | op_ptr += 8; |
| 725 | break; |
| 726 | case DW_OP_constu: |
| 727 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 728 | result = uoffset; |
| 729 | result_val = value_from_ulongest (address_type, result); |
| 730 | break; |
| 731 | case DW_OP_consts: |
| 732 | op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| 733 | result = offset; |
| 734 | result_val = value_from_ulongest (address_type, result); |
| 735 | break; |
| 736 | |
| 737 | /* The DW_OP_reg operations are required to occur alone in |
| 738 | location expressions. */ |
| 739 | case DW_OP_reg0: |
| 740 | case DW_OP_reg1: |
| 741 | case DW_OP_reg2: |
| 742 | case DW_OP_reg3: |
| 743 | case DW_OP_reg4: |
| 744 | case DW_OP_reg5: |
| 745 | case DW_OP_reg6: |
| 746 | case DW_OP_reg7: |
| 747 | case DW_OP_reg8: |
| 748 | case DW_OP_reg9: |
| 749 | case DW_OP_reg10: |
| 750 | case DW_OP_reg11: |
| 751 | case DW_OP_reg12: |
| 752 | case DW_OP_reg13: |
| 753 | case DW_OP_reg14: |
| 754 | case DW_OP_reg15: |
| 755 | case DW_OP_reg16: |
| 756 | case DW_OP_reg17: |
| 757 | case DW_OP_reg18: |
| 758 | case DW_OP_reg19: |
| 759 | case DW_OP_reg20: |
| 760 | case DW_OP_reg21: |
| 761 | case DW_OP_reg22: |
| 762 | case DW_OP_reg23: |
| 763 | case DW_OP_reg24: |
| 764 | case DW_OP_reg25: |
| 765 | case DW_OP_reg26: |
| 766 | case DW_OP_reg27: |
| 767 | case DW_OP_reg28: |
| 768 | case DW_OP_reg29: |
| 769 | case DW_OP_reg30: |
| 770 | case DW_OP_reg31: |
| 771 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_reg"); |
| 772 | |
| 773 | result = op - DW_OP_reg0; |
| 774 | result_val = value_from_ulongest (address_type, result); |
| 775 | this->location = DWARF_VALUE_REGISTER; |
| 776 | break; |
| 777 | |
| 778 | case DW_OP_regx: |
| 779 | op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| 780 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); |
| 781 | |
| 782 | result = reg; |
| 783 | result_val = value_from_ulongest (address_type, result); |
| 784 | this->location = DWARF_VALUE_REGISTER; |
| 785 | break; |
| 786 | |
| 787 | case DW_OP_implicit_value: |
| 788 | { |
| 789 | uint64_t len; |
| 790 | |
| 791 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &len); |
| 792 | if (op_ptr + len > op_end) |
| 793 | error (_("DW_OP_implicit_value: too few bytes available.")); |
| 794 | this->len = len; |
| 795 | this->data = op_ptr; |
| 796 | this->location = DWARF_VALUE_LITERAL; |
| 797 | op_ptr += len; |
| 798 | dwarf_expr_require_composition (op_ptr, op_end, |
| 799 | "DW_OP_implicit_value"); |
| 800 | } |
| 801 | goto no_push; |
| 802 | |
| 803 | case DW_OP_stack_value: |
| 804 | this->location = DWARF_VALUE_STACK; |
| 805 | dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value"); |
| 806 | goto no_push; |
| 807 | |
| 808 | case DW_OP_GNU_implicit_pointer: |
| 809 | { |
| 810 | int64_t len; |
| 811 | |
| 812 | if (this->ref_addr_size == -1) |
| 813 | error (_("DWARF-2 expression error: DW_OP_GNU_implicit_pointer " |
| 814 | "is not allowed in frame context")); |
| 815 | |
| 816 | /* The referred-to DIE of sect_offset kind. */ |
| 817 | this->len = extract_unsigned_integer (op_ptr, this->ref_addr_size, |
| 818 | byte_order); |
| 819 | op_ptr += this->ref_addr_size; |
| 820 | |
| 821 | /* The byte offset into the data. */ |
| 822 | op_ptr = safe_read_sleb128 (op_ptr, op_end, &len); |
| 823 | result = (ULONGEST) len; |
| 824 | result_val = value_from_ulongest (address_type, result); |
| 825 | |
| 826 | this->location = DWARF_VALUE_IMPLICIT_POINTER; |
| 827 | dwarf_expr_require_composition (op_ptr, op_end, |
| 828 | "DW_OP_GNU_implicit_pointer"); |
| 829 | } |
| 830 | break; |
| 831 | |
| 832 | case DW_OP_breg0: |
| 833 | case DW_OP_breg1: |
| 834 | case DW_OP_breg2: |
| 835 | case DW_OP_breg3: |
| 836 | case DW_OP_breg4: |
| 837 | case DW_OP_breg5: |
| 838 | case DW_OP_breg6: |
| 839 | case DW_OP_breg7: |
| 840 | case DW_OP_breg8: |
| 841 | case DW_OP_breg9: |
| 842 | case DW_OP_breg10: |
| 843 | case DW_OP_breg11: |
| 844 | case DW_OP_breg12: |
| 845 | case DW_OP_breg13: |
| 846 | case DW_OP_breg14: |
| 847 | case DW_OP_breg15: |
| 848 | case DW_OP_breg16: |
| 849 | case DW_OP_breg17: |
| 850 | case DW_OP_breg18: |
| 851 | case DW_OP_breg19: |
| 852 | case DW_OP_breg20: |
| 853 | case DW_OP_breg21: |
| 854 | case DW_OP_breg22: |
| 855 | case DW_OP_breg23: |
| 856 | case DW_OP_breg24: |
| 857 | case DW_OP_breg25: |
| 858 | case DW_OP_breg26: |
| 859 | case DW_OP_breg27: |
| 860 | case DW_OP_breg28: |
| 861 | case DW_OP_breg29: |
| 862 | case DW_OP_breg30: |
| 863 | case DW_OP_breg31: |
| 864 | { |
| 865 | op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| 866 | result = this->read_addr_from_reg (op - DW_OP_breg0); |
| 867 | result += offset; |
| 868 | result_val = value_from_ulongest (address_type, result); |
| 869 | } |
| 870 | break; |
| 871 | case DW_OP_bregx: |
| 872 | { |
| 873 | op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| 874 | op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| 875 | result = this->read_addr_from_reg (reg); |
| 876 | result += offset; |
| 877 | result_val = value_from_ulongest (address_type, result); |
| 878 | } |
| 879 | break; |
| 880 | case DW_OP_fbreg: |
| 881 | { |
| 882 | const gdb_byte *datastart; |
| 883 | size_t datalen; |
| 884 | unsigned int before_stack_len; |
| 885 | |
| 886 | op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); |
| 887 | /* Rather than create a whole new context, we simply |
| 888 | record the stack length before execution, then reset it |
| 889 | afterwards, effectively erasing whatever the recursive |
| 890 | call put there. */ |
| 891 | before_stack_len = this->stack_len; |
| 892 | /* FIXME: cagney/2003-03-26: This code should be using |
| 893 | get_frame_base_address(), and then implement a dwarf2 |
| 894 | specific this_base method. */ |
| 895 | this->get_frame_base (&datastart, &datalen); |
| 896 | eval (datastart, datalen); |
| 897 | if (this->location == DWARF_VALUE_MEMORY) |
| 898 | result = fetch_address (0); |
| 899 | else if (this->location == DWARF_VALUE_REGISTER) |
| 900 | result = this->read_addr_from_reg (value_as_long (fetch (0))); |
| 901 | else |
| 902 | error (_("Not implemented: computing frame " |
| 903 | "base using explicit value operator")); |
| 904 | result = result + offset; |
| 905 | result_val = value_from_ulongest (address_type, result); |
| 906 | in_stack_memory = 1; |
| 907 | this->stack_len = before_stack_len; |
| 908 | this->location = DWARF_VALUE_MEMORY; |
| 909 | } |
| 910 | break; |
| 911 | |
| 912 | case DW_OP_dup: |
| 913 | result_val = fetch (0); |
| 914 | in_stack_memory = fetch_in_stack_memory (0); |
| 915 | break; |
| 916 | |
| 917 | case DW_OP_drop: |
| 918 | pop (); |
| 919 | goto no_push; |
| 920 | |
| 921 | case DW_OP_pick: |
| 922 | offset = *op_ptr++; |
| 923 | result_val = fetch (offset); |
| 924 | in_stack_memory = fetch_in_stack_memory (offset); |
| 925 | break; |
| 926 | |
| 927 | case DW_OP_swap: |
| 928 | { |
| 929 | struct dwarf_stack_value t1, t2; |
| 930 | |
| 931 | if (this->stack_len < 2) |
| 932 | error (_("Not enough elements for " |
| 933 | "DW_OP_swap. Need 2, have %d."), |
| 934 | this->stack_len); |
| 935 | t1 = this->stack[this->stack_len - 1]; |
| 936 | t2 = this->stack[this->stack_len - 2]; |
| 937 | this->stack[this->stack_len - 1] = t2; |
| 938 | this->stack[this->stack_len - 2] = t1; |
| 939 | goto no_push; |
| 940 | } |
| 941 | |
| 942 | case DW_OP_over: |
| 943 | result_val = fetch (1); |
| 944 | in_stack_memory = fetch_in_stack_memory (1); |
| 945 | break; |
| 946 | |
| 947 | case DW_OP_rot: |
| 948 | { |
| 949 | struct dwarf_stack_value t1, t2, t3; |
| 950 | |
| 951 | if (this->stack_len < 3) |
| 952 | error (_("Not enough elements for " |
| 953 | "DW_OP_rot. Need 3, have %d."), |
| 954 | this->stack_len); |
| 955 | t1 = this->stack[this->stack_len - 1]; |
| 956 | t2 = this->stack[this->stack_len - 2]; |
| 957 | t3 = this->stack[this->stack_len - 3]; |
| 958 | this->stack[this->stack_len - 1] = t2; |
| 959 | this->stack[this->stack_len - 2] = t3; |
| 960 | this->stack[this->stack_len - 3] = t1; |
| 961 | goto no_push; |
| 962 | } |
| 963 | |
| 964 | case DW_OP_deref: |
| 965 | case DW_OP_deref_size: |
| 966 | case DW_OP_GNU_deref_type: |
| 967 | { |
| 968 | int addr_size = (op == DW_OP_deref ? this->addr_size : *op_ptr++); |
| 969 | gdb_byte *buf = (gdb_byte *) alloca (addr_size); |
| 970 | CORE_ADDR addr = fetch_address (0); |
| 971 | struct type *type; |
| 972 | |
| 973 | pop (); |
| 974 | |
| 975 | if (op == DW_OP_GNU_deref_type) |
| 976 | { |
| 977 | cu_offset type_die; |
| 978 | |
| 979 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 980 | type_die.cu_off = uoffset; |
| 981 | type = get_base_type (type_die, 0); |
| 982 | } |
| 983 | else |
| 984 | type = address_type; |
| 985 | |
| 986 | this->read_mem (buf, addr, addr_size); |
| 987 | |
| 988 | /* If the size of the object read from memory is different |
| 989 | from the type length, we need to zero-extend it. */ |
| 990 | if (TYPE_LENGTH (type) != addr_size) |
| 991 | { |
| 992 | ULONGEST result = |
| 993 | extract_unsigned_integer (buf, addr_size, byte_order); |
| 994 | |
| 995 | buf = (gdb_byte *) alloca (TYPE_LENGTH (type)); |
| 996 | store_unsigned_integer (buf, TYPE_LENGTH (type), |
| 997 | byte_order, result); |
| 998 | } |
| 999 | |
| 1000 | result_val = value_from_contents_and_address (type, buf, addr); |
| 1001 | break; |
| 1002 | } |
| 1003 | |
| 1004 | case DW_OP_abs: |
| 1005 | case DW_OP_neg: |
| 1006 | case DW_OP_not: |
| 1007 | case DW_OP_plus_uconst: |
| 1008 | { |
| 1009 | /* Unary operations. */ |
| 1010 | result_val = fetch (0); |
| 1011 | pop (); |
| 1012 | |
| 1013 | switch (op) |
| 1014 | { |
| 1015 | case DW_OP_abs: |
| 1016 | if (value_less (result_val, |
| 1017 | value_zero (value_type (result_val), not_lval))) |
| 1018 | result_val = value_neg (result_val); |
| 1019 | break; |
| 1020 | case DW_OP_neg: |
| 1021 | result_val = value_neg (result_val); |
| 1022 | break; |
| 1023 | case DW_OP_not: |
| 1024 | dwarf_require_integral (value_type (result_val)); |
| 1025 | result_val = value_complement (result_val); |
| 1026 | break; |
| 1027 | case DW_OP_plus_uconst: |
| 1028 | dwarf_require_integral (value_type (result_val)); |
| 1029 | result = value_as_long (result_val); |
| 1030 | op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| 1031 | result += reg; |
| 1032 | result_val = value_from_ulongest (address_type, result); |
| 1033 | break; |
| 1034 | } |
| 1035 | } |
| 1036 | break; |
| 1037 | |
| 1038 | case DW_OP_and: |
| 1039 | case DW_OP_div: |
| 1040 | case DW_OP_minus: |
| 1041 | case DW_OP_mod: |
| 1042 | case DW_OP_mul: |
| 1043 | case DW_OP_or: |
| 1044 | case DW_OP_plus: |
| 1045 | case DW_OP_shl: |
| 1046 | case DW_OP_shr: |
| 1047 | case DW_OP_shra: |
| 1048 | case DW_OP_xor: |
| 1049 | case DW_OP_le: |
| 1050 | case DW_OP_ge: |
| 1051 | case DW_OP_eq: |
| 1052 | case DW_OP_lt: |
| 1053 | case DW_OP_gt: |
| 1054 | case DW_OP_ne: |
| 1055 | { |
| 1056 | /* Binary operations. */ |
| 1057 | struct value *first, *second; |
| 1058 | |
| 1059 | second = fetch (0); |
| 1060 | pop (); |
| 1061 | |
| 1062 | first = fetch (0); |
| 1063 | pop (); |
| 1064 | |
| 1065 | if (! base_types_equal_p (value_type (first), value_type (second))) |
| 1066 | error (_("Incompatible types on DWARF stack")); |
| 1067 | |
| 1068 | switch (op) |
| 1069 | { |
| 1070 | case DW_OP_and: |
| 1071 | dwarf_require_integral (value_type (first)); |
| 1072 | dwarf_require_integral (value_type (second)); |
| 1073 | result_val = value_binop (first, second, BINOP_BITWISE_AND); |
| 1074 | break; |
| 1075 | case DW_OP_div: |
| 1076 | result_val = value_binop (first, second, BINOP_DIV); |
| 1077 | break; |
| 1078 | case DW_OP_minus: |
| 1079 | result_val = value_binop (first, second, BINOP_SUB); |
| 1080 | break; |
| 1081 | case DW_OP_mod: |
| 1082 | { |
| 1083 | int cast_back = 0; |
| 1084 | struct type *orig_type = value_type (first); |
| 1085 | |
| 1086 | /* We have to special-case "old-style" untyped values |
| 1087 | -- these must have mod computed using unsigned |
| 1088 | math. */ |
| 1089 | if (orig_type == address_type) |
| 1090 | { |
| 1091 | struct type *utype |
| 1092 | = get_unsigned_type (this->gdbarch, orig_type); |
| 1093 | |
| 1094 | cast_back = 1; |
| 1095 | first = value_cast (utype, first); |
| 1096 | second = value_cast (utype, second); |
| 1097 | } |
| 1098 | /* Note that value_binop doesn't handle float or |
| 1099 | decimal float here. This seems unimportant. */ |
| 1100 | result_val = value_binop (first, second, BINOP_MOD); |
| 1101 | if (cast_back) |
| 1102 | result_val = value_cast (orig_type, result_val); |
| 1103 | } |
| 1104 | break; |
| 1105 | case DW_OP_mul: |
| 1106 | result_val = value_binop (first, second, BINOP_MUL); |
| 1107 | break; |
| 1108 | case DW_OP_or: |
| 1109 | dwarf_require_integral (value_type (first)); |
| 1110 | dwarf_require_integral (value_type (second)); |
| 1111 | result_val = value_binop (first, second, BINOP_BITWISE_IOR); |
| 1112 | break; |
| 1113 | case DW_OP_plus: |
| 1114 | result_val = value_binop (first, second, BINOP_ADD); |
| 1115 | break; |
| 1116 | case DW_OP_shl: |
| 1117 | dwarf_require_integral (value_type (first)); |
| 1118 | dwarf_require_integral (value_type (second)); |
| 1119 | result_val = value_binop (first, second, BINOP_LSH); |
| 1120 | break; |
| 1121 | case DW_OP_shr: |
| 1122 | dwarf_require_integral (value_type (first)); |
| 1123 | dwarf_require_integral (value_type (second)); |
| 1124 | if (!TYPE_UNSIGNED (value_type (first))) |
| 1125 | { |
| 1126 | struct type *utype |
| 1127 | = get_unsigned_type (this->gdbarch, value_type (first)); |
| 1128 | |
| 1129 | first = value_cast (utype, first); |
| 1130 | } |
| 1131 | |
| 1132 | result_val = value_binop (first, second, BINOP_RSH); |
| 1133 | /* Make sure we wind up with the same type we started |
| 1134 | with. */ |
| 1135 | if (value_type (result_val) != value_type (second)) |
| 1136 | result_val = value_cast (value_type (second), result_val); |
| 1137 | break; |
| 1138 | case DW_OP_shra: |
| 1139 | dwarf_require_integral (value_type (first)); |
| 1140 | dwarf_require_integral (value_type (second)); |
| 1141 | if (TYPE_UNSIGNED (value_type (first))) |
| 1142 | { |
| 1143 | struct type *stype |
| 1144 | = get_signed_type (this->gdbarch, value_type (first)); |
| 1145 | |
| 1146 | first = value_cast (stype, first); |
| 1147 | } |
| 1148 | |
| 1149 | result_val = value_binop (first, second, BINOP_RSH); |
| 1150 | /* Make sure we wind up with the same type we started |
| 1151 | with. */ |
| 1152 | if (value_type (result_val) != value_type (second)) |
| 1153 | result_val = value_cast (value_type (second), result_val); |
| 1154 | break; |
| 1155 | case DW_OP_xor: |
| 1156 | dwarf_require_integral (value_type (first)); |
| 1157 | dwarf_require_integral (value_type (second)); |
| 1158 | result_val = value_binop (first, second, BINOP_BITWISE_XOR); |
| 1159 | break; |
| 1160 | case DW_OP_le: |
| 1161 | /* A <= B is !(B < A). */ |
| 1162 | result = ! value_less (second, first); |
| 1163 | result_val = value_from_ulongest (address_type, result); |
| 1164 | break; |
| 1165 | case DW_OP_ge: |
| 1166 | /* A >= B is !(A < B). */ |
| 1167 | result = ! value_less (first, second); |
| 1168 | result_val = value_from_ulongest (address_type, result); |
| 1169 | break; |
| 1170 | case DW_OP_eq: |
| 1171 | result = value_equal (first, second); |
| 1172 | result_val = value_from_ulongest (address_type, result); |
| 1173 | break; |
| 1174 | case DW_OP_lt: |
| 1175 | result = value_less (first, second); |
| 1176 | result_val = value_from_ulongest (address_type, result); |
| 1177 | break; |
| 1178 | case DW_OP_gt: |
| 1179 | /* A > B is B < A. */ |
| 1180 | result = value_less (second, first); |
| 1181 | result_val = value_from_ulongest (address_type, result); |
| 1182 | break; |
| 1183 | case DW_OP_ne: |
| 1184 | result = ! value_equal (first, second); |
| 1185 | result_val = value_from_ulongest (address_type, result); |
| 1186 | break; |
| 1187 | default: |
| 1188 | internal_error (__FILE__, __LINE__, |
| 1189 | _("Can't be reached.")); |
| 1190 | } |
| 1191 | } |
| 1192 | break; |
| 1193 | |
| 1194 | case DW_OP_call_frame_cfa: |
| 1195 | result = this->get_frame_cfa (); |
| 1196 | result_val = value_from_ulongest (address_type, result); |
| 1197 | in_stack_memory = 1; |
| 1198 | break; |
| 1199 | |
| 1200 | case DW_OP_GNU_push_tls_address: |
| 1201 | case DW_OP_form_tls_address: |
| 1202 | /* Variable is at a constant offset in the thread-local |
| 1203 | storage block into the objfile for the current thread and |
| 1204 | the dynamic linker module containing this expression. Here |
| 1205 | we return returns the offset from that base. The top of the |
| 1206 | stack has the offset from the beginning of the thread |
| 1207 | control block at which the variable is located. Nothing |
| 1208 | should follow this operator, so the top of stack would be |
| 1209 | returned. */ |
| 1210 | result = value_as_long (fetch (0)); |
| 1211 | pop (); |
| 1212 | result = this->get_tls_address (result); |
| 1213 | result_val = value_from_ulongest (address_type, result); |
| 1214 | break; |
| 1215 | |
| 1216 | case DW_OP_skip: |
| 1217 | offset = extract_signed_integer (op_ptr, 2, byte_order); |
| 1218 | op_ptr += 2; |
| 1219 | op_ptr += offset; |
| 1220 | goto no_push; |
| 1221 | |
| 1222 | case DW_OP_bra: |
| 1223 | { |
| 1224 | struct value *val; |
| 1225 | |
| 1226 | offset = extract_signed_integer (op_ptr, 2, byte_order); |
| 1227 | op_ptr += 2; |
| 1228 | val = fetch (0); |
| 1229 | dwarf_require_integral (value_type (val)); |
| 1230 | if (value_as_long (val) != 0) |
| 1231 | op_ptr += offset; |
| 1232 | pop (); |
| 1233 | } |
| 1234 | goto no_push; |
| 1235 | |
| 1236 | case DW_OP_nop: |
| 1237 | goto no_push; |
| 1238 | |
| 1239 | case DW_OP_piece: |
| 1240 | { |
| 1241 | uint64_t size; |
| 1242 | |
| 1243 | /* Record the piece. */ |
| 1244 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &size); |
| 1245 | add_piece (8 * size, 0); |
| 1246 | |
| 1247 | /* Pop off the address/regnum, and reset the location |
| 1248 | type. */ |
| 1249 | if (this->location != DWARF_VALUE_LITERAL |
| 1250 | && this->location != DWARF_VALUE_OPTIMIZED_OUT) |
| 1251 | pop (); |
| 1252 | this->location = DWARF_VALUE_MEMORY; |
| 1253 | } |
| 1254 | goto no_push; |
| 1255 | |
| 1256 | case DW_OP_bit_piece: |
| 1257 | { |
| 1258 | uint64_t size, offset; |
| 1259 | |
| 1260 | /* Record the piece. */ |
| 1261 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &size); |
| 1262 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset); |
| 1263 | add_piece (size, offset); |
| 1264 | |
| 1265 | /* Pop off the address/regnum, and reset the location |
| 1266 | type. */ |
| 1267 | if (this->location != DWARF_VALUE_LITERAL |
| 1268 | && this->location != DWARF_VALUE_OPTIMIZED_OUT) |
| 1269 | pop (); |
| 1270 | this->location = DWARF_VALUE_MEMORY; |
| 1271 | } |
| 1272 | goto no_push; |
| 1273 | |
| 1274 | case DW_OP_GNU_uninit: |
| 1275 | if (op_ptr != op_end) |
| 1276 | error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always " |
| 1277 | "be the very last op.")); |
| 1278 | |
| 1279 | this->initialized = 0; |
| 1280 | goto no_push; |
| 1281 | |
| 1282 | case DW_OP_call2: |
| 1283 | { |
| 1284 | cu_offset offset; |
| 1285 | |
| 1286 | offset.cu_off = extract_unsigned_integer (op_ptr, 2, byte_order); |
| 1287 | op_ptr += 2; |
| 1288 | this->dwarf_call (offset); |
| 1289 | } |
| 1290 | goto no_push; |
| 1291 | |
| 1292 | case DW_OP_call4: |
| 1293 | { |
| 1294 | cu_offset offset; |
| 1295 | |
| 1296 | offset.cu_off = extract_unsigned_integer (op_ptr, 4, byte_order); |
| 1297 | op_ptr += 4; |
| 1298 | this->dwarf_call (offset); |
| 1299 | } |
| 1300 | goto no_push; |
| 1301 | |
| 1302 | case DW_OP_GNU_entry_value: |
| 1303 | { |
| 1304 | uint64_t len; |
| 1305 | CORE_ADDR deref_size; |
| 1306 | union call_site_parameter_u kind_u; |
| 1307 | |
| 1308 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &len); |
| 1309 | if (op_ptr + len > op_end) |
| 1310 | error (_("DW_OP_GNU_entry_value: too few bytes available.")); |
| 1311 | |
| 1312 | kind_u.dwarf_reg = dwarf_block_to_dwarf_reg (op_ptr, op_ptr + len); |
| 1313 | if (kind_u.dwarf_reg != -1) |
| 1314 | { |
| 1315 | op_ptr += len; |
| 1316 | this->push_dwarf_reg_entry_value (CALL_SITE_PARAMETER_DWARF_REG, |
| 1317 | kind_u, |
| 1318 | -1 /* deref_size */); |
| 1319 | goto no_push; |
| 1320 | } |
| 1321 | |
| 1322 | kind_u.dwarf_reg = dwarf_block_to_dwarf_reg_deref (op_ptr, |
| 1323 | op_ptr + len, |
| 1324 | &deref_size); |
| 1325 | if (kind_u.dwarf_reg != -1) |
| 1326 | { |
| 1327 | if (deref_size == -1) |
| 1328 | deref_size = this->addr_size; |
| 1329 | op_ptr += len; |
| 1330 | this->push_dwarf_reg_entry_value (CALL_SITE_PARAMETER_DWARF_REG, |
| 1331 | kind_u, deref_size); |
| 1332 | goto no_push; |
| 1333 | } |
| 1334 | |
| 1335 | error (_("DWARF-2 expression error: DW_OP_GNU_entry_value is " |
| 1336 | "supported only for single DW_OP_reg* " |
| 1337 | "or for DW_OP_breg*(0)+DW_OP_deref*")); |
| 1338 | } |
| 1339 | |
| 1340 | case DW_OP_GNU_parameter_ref: |
| 1341 | { |
| 1342 | union call_site_parameter_u kind_u; |
| 1343 | |
| 1344 | kind_u.param_offset.cu_off = extract_unsigned_integer (op_ptr, 4, |
| 1345 | byte_order); |
| 1346 | op_ptr += 4; |
| 1347 | this->push_dwarf_reg_entry_value (CALL_SITE_PARAMETER_PARAM_OFFSET, |
| 1348 | kind_u, |
| 1349 | -1 /* deref_size */); |
| 1350 | } |
| 1351 | goto no_push; |
| 1352 | |
| 1353 | case DW_OP_GNU_const_type: |
| 1354 | { |
| 1355 | cu_offset type_die; |
| 1356 | int n; |
| 1357 | const gdb_byte *data; |
| 1358 | struct type *type; |
| 1359 | |
| 1360 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 1361 | type_die.cu_off = uoffset; |
| 1362 | n = *op_ptr++; |
| 1363 | data = op_ptr; |
| 1364 | op_ptr += n; |
| 1365 | |
| 1366 | type = get_base_type (type_die, n); |
| 1367 | result_val = value_from_contents (type, data); |
| 1368 | } |
| 1369 | break; |
| 1370 | |
| 1371 | case DW_OP_GNU_regval_type: |
| 1372 | { |
| 1373 | cu_offset type_die; |
| 1374 | struct type *type; |
| 1375 | |
| 1376 | op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); |
| 1377 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 1378 | type_die.cu_off = uoffset; |
| 1379 | |
| 1380 | type = get_base_type (type_die, 0); |
| 1381 | result_val = this->get_reg_value (type, reg); |
| 1382 | } |
| 1383 | break; |
| 1384 | |
| 1385 | case DW_OP_GNU_convert: |
| 1386 | case DW_OP_GNU_reinterpret: |
| 1387 | { |
| 1388 | cu_offset type_die; |
| 1389 | struct type *type; |
| 1390 | |
| 1391 | op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); |
| 1392 | type_die.cu_off = uoffset; |
| 1393 | |
| 1394 | if (type_die.cu_off == 0) |
| 1395 | type = address_type; |
| 1396 | else |
| 1397 | type = get_base_type (type_die, 0); |
| 1398 | |
| 1399 | result_val = fetch (0); |
| 1400 | pop (); |
| 1401 | |
| 1402 | if (op == DW_OP_GNU_convert) |
| 1403 | result_val = value_cast (type, result_val); |
| 1404 | else if (type == value_type (result_val)) |
| 1405 | { |
| 1406 | /* Nothing. */ |
| 1407 | } |
| 1408 | else if (TYPE_LENGTH (type) |
| 1409 | != TYPE_LENGTH (value_type (result_val))) |
| 1410 | error (_("DW_OP_GNU_reinterpret has wrong size")); |
| 1411 | else |
| 1412 | result_val |
| 1413 | = value_from_contents (type, |
| 1414 | value_contents_all (result_val)); |
| 1415 | } |
| 1416 | break; |
| 1417 | |
| 1418 | case DW_OP_push_object_address: |
| 1419 | /* Return the address of the object we are currently observing. */ |
| 1420 | result = this->get_object_address (); |
| 1421 | result_val = value_from_ulongest (address_type, result); |
| 1422 | break; |
| 1423 | |
| 1424 | default: |
| 1425 | error (_("Unhandled dwarf expression opcode 0x%x"), op); |
| 1426 | } |
| 1427 | |
| 1428 | /* Most things push a result value. */ |
| 1429 | gdb_assert (result_val != NULL); |
| 1430 | push (result_val, in_stack_memory); |
| 1431 | no_push: |
| 1432 | ; |
| 1433 | } |
| 1434 | |
| 1435 | /* To simplify our main caller, if the result is an implicit |
| 1436 | pointer, then make a pieced value. This is ok because we can't |
| 1437 | have implicit pointers in contexts where pieces are invalid. */ |
| 1438 | if (this->location == DWARF_VALUE_IMPLICIT_POINTER) |
| 1439 | add_piece (8 * this->addr_size, 0); |
| 1440 | |
| 1441 | abort_expression: |
| 1442 | this->recursion_depth--; |
| 1443 | gdb_assert (this->recursion_depth >= 0); |
| 1444 | } |
| 1445 | |
| 1446 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 1447 | extern initialize_file_ftype _initialize_dwarf2expr; |
| 1448 | |
| 1449 | void |
| 1450 | _initialize_dwarf2expr (void) |
| 1451 | { |
| 1452 | dwarf_arch_cookie |
| 1453 | = gdbarch_data_register_post_init (dwarf_gdbarch_types_init); |
| 1454 | } |