1 /* Perform non-arithmetic operations on values, for GDB. 2 3 Copyright (C) 1986-2020 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "symtab.h" 22 #include "gdbtypes.h" 23 #include "value.h" 24 #include "frame.h" 25 #include "inferior.h" 26 #include "gdbcore.h" 27 #include "target.h" 28 #include "demangle.h" 29 #include "language.h" 30 #include "gdbcmd.h" 31 #include "regcache.h" 32 #include "cp-abi.h" 33 #include "block.h" 34 #include "infcall.h" 35 #include "dictionary.h" 36 #include "cp-support.h" 37 #include "target-float.h" 38 #include "tracepoint.h" 39 #include "observable.h" 40 #include "objfiles.h" 41 #include "extension.h" 42 #include "gdbtypes.h" 43 #include "gdbsupport/byte-vector.h" 44 45 /* Local functions. */ 46 47 static int typecmp (int staticp, int varargs, int nargs, 48 struct field t1[], struct value *t2[]); 49 50 static struct value *search_struct_field (const char *, struct value *, 51 struct type *, int); 52 53 static struct value *search_struct_method (const char *, struct value **, 54 struct value **, 55 LONGEST, int *, struct type *); 56 57 static int find_oload_champ_namespace (gdb::array_view<value *> args, 58 const char *, const char *, 59 std::vector<symbol *> *oload_syms, 60 badness_vector *, 61 const int no_adl); 62 63 static int find_oload_champ_namespace_loop (gdb::array_view<value *> args, 64 const char *, const char *, 65 int, std::vector<symbol *> *oload_syms, 66 badness_vector *, int *, 67 const int no_adl); 68 69 static int find_oload_champ (gdb::array_view<value *> args, 70 size_t num_fns, 71 fn_field *methods, 72 xmethod_worker_up *xmethods, 73 symbol **functions, 74 badness_vector *oload_champ_bv); 75 76 static int oload_method_static_p (struct fn_field *, int); 77 78 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE }; 79 80 static enum oload_classification classify_oload_match 81 (const badness_vector &, int, int); 82 83 static struct value *value_struct_elt_for_reference (struct type *, 84 int, struct type *, 85 const char *, 86 struct type *, 87 int, enum noside); 88 89 static struct value *value_namespace_elt (const struct type *, 90 const char *, int , enum noside); 91 92 static struct value *value_maybe_namespace_elt (const struct type *, 93 const char *, int, 94 enum noside); 95 96 static CORE_ADDR allocate_space_in_inferior (int); 97 98 static struct value *cast_into_complex (struct type *, struct value *); 99 100 bool overload_resolution = false; 101 static void 102 show_overload_resolution (struct ui_file *file, int from_tty, 103 struct cmd_list_element *c, 104 const char *value) 105 { 106 fprintf_filtered (file, _("Overload resolution in evaluating " 107 "C++ functions is %s.\n"), 108 value); 109 } 110 111 /* Find the address of function name NAME in the inferior. If OBJF_P 112 is non-NULL, *OBJF_P will be set to the OBJFILE where the function 113 is defined. */ 114 115 struct value * 116 find_function_in_inferior (const char *name, struct objfile **objf_p) 117 { 118 struct block_symbol sym; 119 120 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0); 121 if (sym.symbol != NULL) 122 { 123 if (SYMBOL_CLASS (sym.symbol) != LOC_BLOCK) 124 { 125 error (_("\"%s\" exists in this program but is not a function."), 126 name); 127 } 128 129 if (objf_p) 130 *objf_p = symbol_objfile (sym.symbol); 131 132 return value_of_variable (sym.symbol, sym.block); 133 } 134 else 135 { 136 struct bound_minimal_symbol msymbol = 137 lookup_bound_minimal_symbol (name); 138 139 if (msymbol.minsym != NULL) 140 { 141 struct objfile *objfile = msymbol.objfile; 142 struct gdbarch *gdbarch = objfile->arch (); 143 144 struct type *type; 145 CORE_ADDR maddr; 146 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char); 147 type = lookup_function_type (type); 148 type = lookup_pointer_type (type); 149 maddr = BMSYMBOL_VALUE_ADDRESS (msymbol); 150 151 if (objf_p) 152 *objf_p = objfile; 153 154 return value_from_pointer (type, maddr); 155 } 156 else 157 { 158 if (!target_has_execution) 159 error (_("evaluation of this expression " 160 "requires the target program to be active")); 161 else 162 error (_("evaluation of this expression requires the " 163 "program to have a function \"%s\"."), 164 name); 165 } 166 } 167 } 168 169 /* Allocate NBYTES of space in the inferior using the inferior's 170 malloc and return a value that is a pointer to the allocated 171 space. */ 172 173 struct value * 174 value_allocate_space_in_inferior (int len) 175 { 176 struct objfile *objf; 177 struct value *val = find_function_in_inferior ("malloc", &objf); 178 struct gdbarch *gdbarch = objf->arch (); 179 struct value *blocklen; 180 181 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len); 182 val = call_function_by_hand (val, NULL, blocklen); 183 if (value_logical_not (val)) 184 { 185 if (!target_has_execution) 186 error (_("No memory available to program now: " 187 "you need to start the target first")); 188 else 189 error (_("No memory available to program: call to malloc failed")); 190 } 191 return val; 192 } 193 194 static CORE_ADDR 195 allocate_space_in_inferior (int len) 196 { 197 return value_as_long (value_allocate_space_in_inferior (len)); 198 } 199 200 /* Cast struct value VAL to type TYPE and return as a value. 201 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION 202 for this to work. Typedef to one of the codes is permitted. 203 Returns NULL if the cast is neither an upcast nor a downcast. */ 204 205 static struct value * 206 value_cast_structs (struct type *type, struct value *v2) 207 { 208 struct type *t1; 209 struct type *t2; 210 struct value *v; 211 212 gdb_assert (type != NULL && v2 != NULL); 213 214 t1 = check_typedef (type); 215 t2 = check_typedef (value_type (v2)); 216 217 /* Check preconditions. */ 218 gdb_assert ((t1->code () == TYPE_CODE_STRUCT 219 || t1->code () == TYPE_CODE_UNION) 220 && !!"Precondition is that type is of STRUCT or UNION kind."); 221 gdb_assert ((t2->code () == TYPE_CODE_STRUCT 222 || t2->code () == TYPE_CODE_UNION) 223 && !!"Precondition is that value is of STRUCT or UNION kind"); 224 225 if (t1->name () != NULL 226 && t2->name () != NULL 227 && !strcmp (t1->name (), t2->name ())) 228 return NULL; 229 230 /* Upcasting: look in the type of the source to see if it contains the 231 type of the target as a superclass. If so, we'll need to 232 offset the pointer rather than just change its type. */ 233 if (t1->name () != NULL) 234 { 235 v = search_struct_field (t1->name (), 236 v2, t2, 1); 237 if (v) 238 return v; 239 } 240 241 /* Downcasting: look in the type of the target to see if it contains the 242 type of the source as a superclass. If so, we'll need to 243 offset the pointer rather than just change its type. */ 244 if (t2->name () != NULL) 245 { 246 /* Try downcasting using the run-time type of the value. */ 247 int full, using_enc; 248 LONGEST top; 249 struct type *real_type; 250 251 real_type = value_rtti_type (v2, &full, &top, &using_enc); 252 if (real_type) 253 { 254 v = value_full_object (v2, real_type, full, top, using_enc); 255 v = value_at_lazy (real_type, value_address (v)); 256 real_type = value_type (v); 257 258 /* We might be trying to cast to the outermost enclosing 259 type, in which case search_struct_field won't work. */ 260 if (real_type->name () != NULL 261 && !strcmp (real_type->name (), t1->name ())) 262 return v; 263 264 v = search_struct_field (t2->name (), v, real_type, 1); 265 if (v) 266 return v; 267 } 268 269 /* Try downcasting using information from the destination type 270 T2. This wouldn't work properly for classes with virtual 271 bases, but those were handled above. */ 272 v = search_struct_field (t2->name (), 273 value_zero (t1, not_lval), t1, 1); 274 if (v) 275 { 276 /* Downcasting is possible (t1 is superclass of v2). */ 277 CORE_ADDR addr2 = value_address (v2); 278 279 addr2 -= value_address (v) + value_embedded_offset (v); 280 return value_at (type, addr2); 281 } 282 } 283 284 return NULL; 285 } 286 287 /* Cast one pointer or reference type to another. Both TYPE and 288 the type of ARG2 should be pointer types, or else both should be 289 reference types. If SUBCLASS_CHECK is non-zero, this will force a 290 check to see whether TYPE is a superclass of ARG2's type. If 291 SUBCLASS_CHECK is zero, then the subclass check is done only when 292 ARG2 is itself non-zero. Returns the new pointer or reference. */ 293 294 struct value * 295 value_cast_pointers (struct type *type, struct value *arg2, 296 int subclass_check) 297 { 298 struct type *type1 = check_typedef (type); 299 struct type *type2 = check_typedef (value_type (arg2)); 300 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1)); 301 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2)); 302 303 if (t1->code () == TYPE_CODE_STRUCT 304 && t2->code () == TYPE_CODE_STRUCT 305 && (subclass_check || !value_logical_not (arg2))) 306 { 307 struct value *v2; 308 309 if (TYPE_IS_REFERENCE (type2)) 310 v2 = coerce_ref (arg2); 311 else 312 v2 = value_ind (arg2); 313 gdb_assert (check_typedef (value_type (v2))->code () 314 == TYPE_CODE_STRUCT && !!"Why did coercion fail?"); 315 v2 = value_cast_structs (t1, v2); 316 /* At this point we have what we can have, un-dereference if needed. */ 317 if (v2) 318 { 319 struct value *v = value_addr (v2); 320 321 deprecated_set_value_type (v, type); 322 return v; 323 } 324 } 325 326 /* No superclass found, just change the pointer type. */ 327 arg2 = value_copy (arg2); 328 deprecated_set_value_type (arg2, type); 329 set_value_enclosing_type (arg2, type); 330 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */ 331 return arg2; 332 } 333 334 /* Cast value ARG2 to type TYPE and return as a value. 335 More general than a C cast: accepts any two types of the same length, 336 and if ARG2 is an lvalue it can be cast into anything at all. */ 337 /* In C++, casts may change pointer or object representations. */ 338 339 struct value * 340 value_cast (struct type *type, struct value *arg2) 341 { 342 enum type_code code1; 343 enum type_code code2; 344 int scalar; 345 struct type *type2; 346 347 int convert_to_boolean = 0; 348 349 if (value_type (arg2) == type) 350 return arg2; 351 352 /* Check if we are casting struct reference to struct reference. */ 353 if (TYPE_IS_REFERENCE (check_typedef (type))) 354 { 355 /* We dereference type; then we recurse and finally 356 we generate value of the given reference. Nothing wrong with 357 that. */ 358 struct type *t1 = check_typedef (type); 359 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1)); 360 struct value *val = value_cast (dereftype, arg2); 361 362 return value_ref (val, t1->code ()); 363 } 364 365 if (TYPE_IS_REFERENCE (check_typedef (value_type (arg2)))) 366 /* We deref the value and then do the cast. */ 367 return value_cast (type, coerce_ref (arg2)); 368 369 /* Strip typedefs / resolve stubs in order to get at the type's 370 code/length, but remember the original type, to use as the 371 resulting type of the cast, in case it was a typedef. */ 372 struct type *to_type = type; 373 374 type = check_typedef (type); 375 code1 = type->code (); 376 arg2 = coerce_ref (arg2); 377 type2 = check_typedef (value_type (arg2)); 378 379 /* You can't cast to a reference type. See value_cast_pointers 380 instead. */ 381 gdb_assert (!TYPE_IS_REFERENCE (type)); 382 383 /* A cast to an undetermined-length array_type, such as 384 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT, 385 where N is sizeof(OBJECT)/sizeof(TYPE). */ 386 if (code1 == TYPE_CODE_ARRAY) 387 { 388 struct type *element_type = TYPE_TARGET_TYPE (type); 389 unsigned element_length = TYPE_LENGTH (check_typedef (element_type)); 390 391 if (element_length > 0 && type->bounds ()->high.kind () == PROP_UNDEFINED) 392 { 393 struct type *range_type = type->index_type (); 394 int val_length = TYPE_LENGTH (type2); 395 LONGEST low_bound, high_bound, new_length; 396 397 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0) 398 low_bound = 0, high_bound = 0; 399 new_length = val_length / element_length; 400 if (val_length % element_length != 0) 401 warning (_("array element type size does not " 402 "divide object size in cast")); 403 /* FIXME-type-allocation: need a way to free this type when 404 we are done with it. */ 405 range_type = create_static_range_type (NULL, 406 TYPE_TARGET_TYPE (range_type), 407 low_bound, 408 new_length + low_bound - 1); 409 deprecated_set_value_type (arg2, 410 create_array_type (NULL, 411 element_type, 412 range_type)); 413 return arg2; 414 } 415 } 416 417 if (current_language->c_style_arrays 418 && type2->code () == TYPE_CODE_ARRAY 419 && !TYPE_VECTOR (type2)) 420 arg2 = value_coerce_array (arg2); 421 422 if (type2->code () == TYPE_CODE_FUNC) 423 arg2 = value_coerce_function (arg2); 424 425 type2 = check_typedef (value_type (arg2)); 426 code2 = type2->code (); 427 428 if (code1 == TYPE_CODE_COMPLEX) 429 return cast_into_complex (to_type, arg2); 430 if (code1 == TYPE_CODE_BOOL) 431 { 432 code1 = TYPE_CODE_INT; 433 convert_to_boolean = 1; 434 } 435 if (code1 == TYPE_CODE_CHAR) 436 code1 = TYPE_CODE_INT; 437 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR) 438 code2 = TYPE_CODE_INT; 439 440 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT 441 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM 442 || code2 == TYPE_CODE_RANGE); 443 444 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION) 445 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION) 446 && type->name () != 0) 447 { 448 struct value *v = value_cast_structs (to_type, arg2); 449 450 if (v) 451 return v; 452 } 453 454 if (is_floating_type (type) && scalar) 455 { 456 if (is_floating_value (arg2)) 457 { 458 struct value *v = allocate_value (to_type); 459 target_float_convert (value_contents (arg2), type2, 460 value_contents_raw (v), type); 461 return v; 462 } 463 464 /* The only option left is an integral type. */ 465 if (TYPE_UNSIGNED (type2)) 466 return value_from_ulongest (to_type, value_as_long (arg2)); 467 else 468 return value_from_longest (to_type, value_as_long (arg2)); 469 } 470 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM 471 || code1 == TYPE_CODE_RANGE) 472 && (scalar || code2 == TYPE_CODE_PTR 473 || code2 == TYPE_CODE_MEMBERPTR)) 474 { 475 LONGEST longest; 476 477 /* When we cast pointers to integers, we mustn't use 478 gdbarch_pointer_to_address to find the address the pointer 479 represents, as value_as_long would. GDB should evaluate 480 expressions just as the compiler would --- and the compiler 481 sees a cast as a simple reinterpretation of the pointer's 482 bits. */ 483 if (code2 == TYPE_CODE_PTR) 484 longest = extract_unsigned_integer 485 (value_contents (arg2), TYPE_LENGTH (type2), 486 type_byte_order (type2)); 487 else 488 longest = value_as_long (arg2); 489 return value_from_longest (to_type, convert_to_boolean ? 490 (LONGEST) (longest ? 1 : 0) : longest); 491 } 492 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT 493 || code2 == TYPE_CODE_ENUM 494 || code2 == TYPE_CODE_RANGE)) 495 { 496 /* TYPE_LENGTH (type) is the length of a pointer, but we really 497 want the length of an address! -- we are really dealing with 498 addresses (i.e., gdb representations) not pointers (i.e., 499 target representations) here. 500 501 This allows things like "print *(int *)0x01000234" to work 502 without printing a misleading message -- which would 503 otherwise occur when dealing with a target having two byte 504 pointers and four byte addresses. */ 505 506 int addr_bit = gdbarch_addr_bit (get_type_arch (type2)); 507 LONGEST longest = value_as_long (arg2); 508 509 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT) 510 { 511 if (longest >= ((LONGEST) 1 << addr_bit) 512 || longest <= -((LONGEST) 1 << addr_bit)) 513 warning (_("value truncated")); 514 } 515 return value_from_longest (to_type, longest); 516 } 517 else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT 518 && value_as_long (arg2) == 0) 519 { 520 struct value *result = allocate_value (to_type); 521 522 cplus_make_method_ptr (to_type, value_contents_writeable (result), 0, 0); 523 return result; 524 } 525 else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT 526 && value_as_long (arg2) == 0) 527 { 528 /* The Itanium C++ ABI represents NULL pointers to members as 529 minus one, instead of biasing the normal case. */ 530 return value_from_longest (to_type, -1); 531 } 532 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) 533 && code2 == TYPE_CODE_ARRAY && TYPE_VECTOR (type2) 534 && TYPE_LENGTH (type) != TYPE_LENGTH (type2)) 535 error (_("Cannot convert between vector values of different sizes")); 536 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar 537 && TYPE_LENGTH (type) != TYPE_LENGTH (type2)) 538 error (_("can only cast scalar to vector of same size")); 539 else if (code1 == TYPE_CODE_VOID) 540 { 541 return value_zero (to_type, not_lval); 542 } 543 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2)) 544 { 545 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR) 546 return value_cast_pointers (to_type, arg2, 0); 547 548 arg2 = value_copy (arg2); 549 deprecated_set_value_type (arg2, to_type); 550 set_value_enclosing_type (arg2, to_type); 551 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */ 552 return arg2; 553 } 554 else if (VALUE_LVAL (arg2) == lval_memory) 555 return value_at_lazy (to_type, value_address (arg2)); 556 else 557 { 558 if (current_language->la_language == language_ada) 559 error (_("Invalid type conversion.")); 560 error (_("Invalid cast.")); 561 } 562 } 563 564 /* The C++ reinterpret_cast operator. */ 565 566 struct value * 567 value_reinterpret_cast (struct type *type, struct value *arg) 568 { 569 struct value *result; 570 struct type *real_type = check_typedef (type); 571 struct type *arg_type, *dest_type; 572 int is_ref = 0; 573 enum type_code dest_code, arg_code; 574 575 /* Do reference, function, and array conversion. */ 576 arg = coerce_array (arg); 577 578 /* Attempt to preserve the type the user asked for. */ 579 dest_type = type; 580 581 /* If we are casting to a reference type, transform 582 reinterpret_cast<T&[&]>(V) to *reinterpret_cast<T*>(&V). */ 583 if (TYPE_IS_REFERENCE (real_type)) 584 { 585 is_ref = 1; 586 arg = value_addr (arg); 587 dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type)); 588 real_type = lookup_pointer_type (real_type); 589 } 590 591 arg_type = value_type (arg); 592 593 dest_code = real_type->code (); 594 arg_code = arg_type->code (); 595 596 /* We can convert pointer types, or any pointer type to int, or int 597 type to pointer. */ 598 if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT) 599 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR) 600 || (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT) 601 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR) 602 || (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT) 603 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR) 604 || (dest_code == arg_code 605 && (dest_code == TYPE_CODE_PTR 606 || dest_code == TYPE_CODE_METHODPTR 607 || dest_code == TYPE_CODE_MEMBERPTR))) 608 result = value_cast (dest_type, arg); 609 else 610 error (_("Invalid reinterpret_cast")); 611 612 if (is_ref) 613 result = value_cast (type, value_ref (value_ind (result), 614 type->code ())); 615 616 return result; 617 } 618 619 /* A helper for value_dynamic_cast. This implements the first of two 620 runtime checks: we iterate over all the base classes of the value's 621 class which are equal to the desired class; if only one of these 622 holds the value, then it is the answer. */ 623 624 static int 625 dynamic_cast_check_1 (struct type *desired_type, 626 const gdb_byte *valaddr, 627 LONGEST embedded_offset, 628 CORE_ADDR address, 629 struct value *val, 630 struct type *search_type, 631 CORE_ADDR arg_addr, 632 struct type *arg_type, 633 struct value **result) 634 { 635 int i, result_count = 0; 636 637 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i) 638 { 639 LONGEST offset = baseclass_offset (search_type, i, valaddr, 640 embedded_offset, 641 address, val); 642 643 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i))) 644 { 645 if (address + embedded_offset + offset >= arg_addr 646 && address + embedded_offset + offset < arg_addr + TYPE_LENGTH (arg_type)) 647 { 648 ++result_count; 649 if (!*result) 650 *result = value_at_lazy (TYPE_BASECLASS (search_type, i), 651 address + embedded_offset + offset); 652 } 653 } 654 else 655 result_count += dynamic_cast_check_1 (desired_type, 656 valaddr, 657 embedded_offset + offset, 658 address, val, 659 TYPE_BASECLASS (search_type, i), 660 arg_addr, 661 arg_type, 662 result); 663 } 664 665 return result_count; 666 } 667 668 /* A helper for value_dynamic_cast. This implements the second of two 669 runtime checks: we look for a unique public sibling class of the 670 argument's declared class. */ 671 672 static int 673 dynamic_cast_check_2 (struct type *desired_type, 674 const gdb_byte *valaddr, 675 LONGEST embedded_offset, 676 CORE_ADDR address, 677 struct value *val, 678 struct type *search_type, 679 struct value **result) 680 { 681 int i, result_count = 0; 682 683 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i) 684 { 685 LONGEST offset; 686 687 if (! BASETYPE_VIA_PUBLIC (search_type, i)) 688 continue; 689 690 offset = baseclass_offset (search_type, i, valaddr, embedded_offset, 691 address, val); 692 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i))) 693 { 694 ++result_count; 695 if (*result == NULL) 696 *result = value_at_lazy (TYPE_BASECLASS (search_type, i), 697 address + embedded_offset + offset); 698 } 699 else 700 result_count += dynamic_cast_check_2 (desired_type, 701 valaddr, 702 embedded_offset + offset, 703 address, val, 704 TYPE_BASECLASS (search_type, i), 705 result); 706 } 707 708 return result_count; 709 } 710 711 /* The C++ dynamic_cast operator. */ 712 713 struct value * 714 value_dynamic_cast (struct type *type, struct value *arg) 715 { 716 int full, using_enc; 717 LONGEST top; 718 struct type *resolved_type = check_typedef (type); 719 struct type *arg_type = check_typedef (value_type (arg)); 720 struct type *class_type, *rtti_type; 721 struct value *result, *tem, *original_arg = arg; 722 CORE_ADDR addr; 723 int is_ref = TYPE_IS_REFERENCE (resolved_type); 724 725 if (resolved_type->code () != TYPE_CODE_PTR 726 && !TYPE_IS_REFERENCE (resolved_type)) 727 error (_("Argument to dynamic_cast must be a pointer or reference type")); 728 if (TYPE_TARGET_TYPE (resolved_type)->code () != TYPE_CODE_VOID 729 && TYPE_TARGET_TYPE (resolved_type)->code () != TYPE_CODE_STRUCT) 730 error (_("Argument to dynamic_cast must be pointer to class or `void *'")); 731 732 class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type)); 733 if (resolved_type->code () == TYPE_CODE_PTR) 734 { 735 if (arg_type->code () != TYPE_CODE_PTR 736 && ! (arg_type->code () == TYPE_CODE_INT 737 && value_as_long (arg) == 0)) 738 error (_("Argument to dynamic_cast does not have pointer type")); 739 if (arg_type->code () == TYPE_CODE_PTR) 740 { 741 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type)); 742 if (arg_type->code () != TYPE_CODE_STRUCT) 743 error (_("Argument to dynamic_cast does " 744 "not have pointer to class type")); 745 } 746 747 /* Handle NULL pointers. */ 748 if (value_as_long (arg) == 0) 749 return value_zero (type, not_lval); 750 751 arg = value_ind (arg); 752 } 753 else 754 { 755 if (arg_type->code () != TYPE_CODE_STRUCT) 756 error (_("Argument to dynamic_cast does not have class type")); 757 } 758 759 /* If the classes are the same, just return the argument. */ 760 if (class_types_same_p (class_type, arg_type)) 761 return value_cast (type, arg); 762 763 /* If the target type is a unique base class of the argument's 764 declared type, just cast it. */ 765 if (is_ancestor (class_type, arg_type)) 766 { 767 if (is_unique_ancestor (class_type, arg)) 768 return value_cast (type, original_arg); 769 error (_("Ambiguous dynamic_cast")); 770 } 771 772 rtti_type = value_rtti_type (arg, &full, &top, &using_enc); 773 if (! rtti_type) 774 error (_("Couldn't determine value's most derived type for dynamic_cast")); 775 776 /* Compute the most derived object's address. */ 777 addr = value_address (arg); 778 if (full) 779 { 780 /* Done. */ 781 } 782 else if (using_enc) 783 addr += top; 784 else 785 addr += top + value_embedded_offset (arg); 786 787 /* dynamic_cast<void *> means to return a pointer to the 788 most-derived object. */ 789 if (resolved_type->code () == TYPE_CODE_PTR 790 && TYPE_TARGET_TYPE (resolved_type)->code () == TYPE_CODE_VOID) 791 return value_at_lazy (type, addr); 792 793 tem = value_at (type, addr); 794 type = value_type (tem); 795 796 /* The first dynamic check specified in 5.2.7. */ 797 if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type))) 798 { 799 if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type))) 800 return tem; 801 result = NULL; 802 if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type), 803 value_contents_for_printing (tem), 804 value_embedded_offset (tem), 805 value_address (tem), tem, 806 rtti_type, addr, 807 arg_type, 808 &result) == 1) 809 return value_cast (type, 810 is_ref 811 ? value_ref (result, resolved_type->code ()) 812 : value_addr (result)); 813 } 814 815 /* The second dynamic check specified in 5.2.7. */ 816 result = NULL; 817 if (is_public_ancestor (arg_type, rtti_type) 818 && dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type), 819 value_contents_for_printing (tem), 820 value_embedded_offset (tem), 821 value_address (tem), tem, 822 rtti_type, &result) == 1) 823 return value_cast (type, 824 is_ref 825 ? value_ref (result, resolved_type->code ()) 826 : value_addr (result)); 827 828 if (resolved_type->code () == TYPE_CODE_PTR) 829 return value_zero (type, not_lval); 830 831 error (_("dynamic_cast failed")); 832 } 833 834 /* Create a value of type TYPE that is zero, and return it. */ 835 836 struct value * 837 value_zero (struct type *type, enum lval_type lv) 838 { 839 struct value *val = allocate_value (type); 840 841 VALUE_LVAL (val) = (lv == lval_computed ? not_lval : lv); 842 return val; 843 } 844 845 /* Create a not_lval value of numeric type TYPE that is one, and return it. */ 846 847 struct value * 848 value_one (struct type *type) 849 { 850 struct type *type1 = check_typedef (type); 851 struct value *val; 852 853 if (is_integral_type (type1) || is_floating_type (type1)) 854 { 855 val = value_from_longest (type, (LONGEST) 1); 856 } 857 else if (type1->code () == TYPE_CODE_ARRAY && TYPE_VECTOR (type1)) 858 { 859 struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1)); 860 int i; 861 LONGEST low_bound, high_bound; 862 struct value *tmp; 863 864 if (!get_array_bounds (type1, &low_bound, &high_bound)) 865 error (_("Could not determine the vector bounds")); 866 867 val = allocate_value (type); 868 for (i = 0; i < high_bound - low_bound + 1; i++) 869 { 870 tmp = value_one (eltype); 871 memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype), 872 value_contents_all (tmp), TYPE_LENGTH (eltype)); 873 } 874 } 875 else 876 { 877 error (_("Not a numeric type.")); 878 } 879 880 /* value_one result is never used for assignments to. */ 881 gdb_assert (VALUE_LVAL (val) == not_lval); 882 883 return val; 884 } 885 886 /* Helper function for value_at, value_at_lazy, and value_at_lazy_stack. 887 The type of the created value may differ from the passed type TYPE. 888 Make sure to retrieve the returned values's new type after this call 889 e.g. in case the type is a variable length array. */ 890 891 static struct value * 892 get_value_at (struct type *type, CORE_ADDR addr, int lazy) 893 { 894 struct value *val; 895 896 if (check_typedef (type)->code () == TYPE_CODE_VOID) 897 error (_("Attempt to dereference a generic pointer.")); 898 899 val = value_from_contents_and_address (type, NULL, addr); 900 901 if (!lazy) 902 value_fetch_lazy (val); 903 904 return val; 905 } 906 907 /* Return a value with type TYPE located at ADDR. 908 909 Call value_at only if the data needs to be fetched immediately; 910 if we can be 'lazy' and defer the fetch, perhaps indefinitely, call 911 value_at_lazy instead. value_at_lazy simply records the address of 912 the data and sets the lazy-evaluation-required flag. The lazy flag 913 is tested in the value_contents macro, which is used if and when 914 the contents are actually required. The type of the created value 915 may differ from the passed type TYPE. Make sure to retrieve the 916 returned values's new type after this call e.g. in case the type 917 is a variable length array. 918 919 Note: value_at does *NOT* handle embedded offsets; perform such 920 adjustments before or after calling it. */ 921 922 struct value * 923 value_at (struct type *type, CORE_ADDR addr) 924 { 925 return get_value_at (type, addr, 0); 926 } 927 928 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). 929 The type of the created value may differ from the passed type TYPE. 930 Make sure to retrieve the returned values's new type after this call 931 e.g. in case the type is a variable length array. */ 932 933 struct value * 934 value_at_lazy (struct type *type, CORE_ADDR addr) 935 { 936 return get_value_at (type, addr, 1); 937 } 938 939 void 940 read_value_memory (struct value *val, LONGEST bit_offset, 941 int stack, CORE_ADDR memaddr, 942 gdb_byte *buffer, size_t length) 943 { 944 ULONGEST xfered_total = 0; 945 struct gdbarch *arch = get_value_arch (val); 946 int unit_size = gdbarch_addressable_memory_unit_size (arch); 947 enum target_object object; 948 949 object = stack ? TARGET_OBJECT_STACK_MEMORY : TARGET_OBJECT_MEMORY; 950 951 while (xfered_total < length) 952 { 953 enum target_xfer_status status; 954 ULONGEST xfered_partial; 955 956 status = target_xfer_partial (current_top_target (), 957 object, NULL, 958 buffer + xfered_total * unit_size, NULL, 959 memaddr + xfered_total, 960 length - xfered_total, 961 &xfered_partial); 962 963 if (status == TARGET_XFER_OK) 964 /* nothing */; 965 else if (status == TARGET_XFER_UNAVAILABLE) 966 mark_value_bits_unavailable (val, (xfered_total * HOST_CHAR_BIT 967 + bit_offset), 968 xfered_partial * HOST_CHAR_BIT); 969 else if (status == TARGET_XFER_EOF) 970 memory_error (TARGET_XFER_E_IO, memaddr + xfered_total); 971 else 972 memory_error (status, memaddr + xfered_total); 973 974 xfered_total += xfered_partial; 975 QUIT; 976 } 977 } 978 979 /* Store the contents of FROMVAL into the location of TOVAL. 980 Return a new value with the location of TOVAL and contents of FROMVAL. */ 981 982 struct value * 983 value_assign (struct value *toval, struct value *fromval) 984 { 985 struct type *type; 986 struct value *val; 987 struct frame_id old_frame; 988 989 if (!deprecated_value_modifiable (toval)) 990 error (_("Left operand of assignment is not a modifiable lvalue.")); 991 992 toval = coerce_ref (toval); 993 994 type = value_type (toval); 995 if (VALUE_LVAL (toval) != lval_internalvar) 996 fromval = value_cast (type, fromval); 997 else 998 { 999 /* Coerce arrays and functions to pointers, except for arrays 1000 which only live in GDB's storage. */ 1001 if (!value_must_coerce_to_target (fromval)) 1002 fromval = coerce_array (fromval); 1003 } 1004 1005 type = check_typedef (type); 1006 1007 /* Since modifying a register can trash the frame chain, and 1008 modifying memory can trash the frame cache, we save the old frame 1009 and then restore the new frame afterwards. */ 1010 old_frame = get_frame_id (deprecated_safe_get_selected_frame ()); 1011 1012 switch (VALUE_LVAL (toval)) 1013 { 1014 case lval_internalvar: 1015 set_internalvar (VALUE_INTERNALVAR (toval), fromval); 1016 return value_of_internalvar (get_type_arch (type), 1017 VALUE_INTERNALVAR (toval)); 1018 1019 case lval_internalvar_component: 1020 { 1021 LONGEST offset = value_offset (toval); 1022 1023 /* Are we dealing with a bitfield? 1024 1025 It is important to mention that `value_parent (toval)' is 1026 non-NULL iff `value_bitsize (toval)' is non-zero. */ 1027 if (value_bitsize (toval)) 1028 { 1029 /* VALUE_INTERNALVAR below refers to the parent value, while 1030 the offset is relative to this parent value. */ 1031 gdb_assert (value_parent (value_parent (toval)) == NULL); 1032 offset += value_offset (value_parent (toval)); 1033 } 1034 1035 set_internalvar_component (VALUE_INTERNALVAR (toval), 1036 offset, 1037 value_bitpos (toval), 1038 value_bitsize (toval), 1039 fromval); 1040 } 1041 break; 1042 1043 case lval_memory: 1044 { 1045 const gdb_byte *dest_buffer; 1046 CORE_ADDR changed_addr; 1047 int changed_len; 1048 gdb_byte buffer[sizeof (LONGEST)]; 1049 1050 if (value_bitsize (toval)) 1051 { 1052 struct value *parent = value_parent (toval); 1053 1054 changed_addr = value_address (parent) + value_offset (toval); 1055 changed_len = (value_bitpos (toval) 1056 + value_bitsize (toval) 1057 + HOST_CHAR_BIT - 1) 1058 / HOST_CHAR_BIT; 1059 1060 /* If we can read-modify-write exactly the size of the 1061 containing type (e.g. short or int) then do so. This 1062 is safer for volatile bitfields mapped to hardware 1063 registers. */ 1064 if (changed_len < TYPE_LENGTH (type) 1065 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST) 1066 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0) 1067 changed_len = TYPE_LENGTH (type); 1068 1069 if (changed_len > (int) sizeof (LONGEST)) 1070 error (_("Can't handle bitfields which " 1071 "don't fit in a %d bit word."), 1072 (int) sizeof (LONGEST) * HOST_CHAR_BIT); 1073 1074 read_memory (changed_addr, buffer, changed_len); 1075 modify_field (type, buffer, value_as_long (fromval), 1076 value_bitpos (toval), value_bitsize (toval)); 1077 dest_buffer = buffer; 1078 } 1079 else 1080 { 1081 changed_addr = value_address (toval); 1082 changed_len = type_length_units (type); 1083 dest_buffer = value_contents (fromval); 1084 } 1085 1086 write_memory_with_notification (changed_addr, dest_buffer, changed_len); 1087 } 1088 break; 1089 1090 case lval_register: 1091 { 1092 struct frame_info *frame; 1093 struct gdbarch *gdbarch; 1094 int value_reg; 1095 1096 /* Figure out which frame this is in currently. 1097 1098 We use VALUE_FRAME_ID for obtaining the value's frame id instead of 1099 VALUE_NEXT_FRAME_ID due to requiring a frame which may be passed to 1100 put_frame_register_bytes() below. That function will (eventually) 1101 perform the necessary unwind operation by first obtaining the next 1102 frame. */ 1103 frame = frame_find_by_id (VALUE_FRAME_ID (toval)); 1104 1105 value_reg = VALUE_REGNUM (toval); 1106 1107 if (!frame) 1108 error (_("Value being assigned to is no longer active.")); 1109 1110 gdbarch = get_frame_arch (frame); 1111 1112 if (value_bitsize (toval)) 1113 { 1114 struct value *parent = value_parent (toval); 1115 LONGEST offset = value_offset (parent) + value_offset (toval); 1116 int changed_len; 1117 gdb_byte buffer[sizeof (LONGEST)]; 1118 int optim, unavail; 1119 1120 changed_len = (value_bitpos (toval) 1121 + value_bitsize (toval) 1122 + HOST_CHAR_BIT - 1) 1123 / HOST_CHAR_BIT; 1124 1125 if (changed_len > (int) sizeof (LONGEST)) 1126 error (_("Can't handle bitfields which " 1127 "don't fit in a %d bit word."), 1128 (int) sizeof (LONGEST) * HOST_CHAR_BIT); 1129 1130 if (!get_frame_register_bytes (frame, value_reg, offset, 1131 changed_len, buffer, 1132 &optim, &unavail)) 1133 { 1134 if (optim) 1135 throw_error (OPTIMIZED_OUT_ERROR, 1136 _("value has been optimized out")); 1137 if (unavail) 1138 throw_error (NOT_AVAILABLE_ERROR, 1139 _("value is not available")); 1140 } 1141 1142 modify_field (type, buffer, value_as_long (fromval), 1143 value_bitpos (toval), value_bitsize (toval)); 1144 1145 put_frame_register_bytes (frame, value_reg, offset, 1146 changed_len, buffer); 1147 } 1148 else 1149 { 1150 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval), 1151 type)) 1152 { 1153 /* If TOVAL is a special machine register requiring 1154 conversion of program values to a special raw 1155 format. */ 1156 gdbarch_value_to_register (gdbarch, frame, 1157 VALUE_REGNUM (toval), type, 1158 value_contents (fromval)); 1159 } 1160 else 1161 { 1162 put_frame_register_bytes (frame, value_reg, 1163 value_offset (toval), 1164 TYPE_LENGTH (type), 1165 value_contents (fromval)); 1166 } 1167 } 1168 1169 gdb::observers::register_changed.notify (frame, value_reg); 1170 break; 1171 } 1172 1173 case lval_computed: 1174 { 1175 const struct lval_funcs *funcs = value_computed_funcs (toval); 1176 1177 if (funcs->write != NULL) 1178 { 1179 funcs->write (toval, fromval); 1180 break; 1181 } 1182 } 1183 /* Fall through. */ 1184 1185 default: 1186 error (_("Left operand of assignment is not an lvalue.")); 1187 } 1188 1189 /* Assigning to the stack pointer, frame pointer, and other 1190 (architecture and calling convention specific) registers may 1191 cause the frame cache and regcache to be out of date. Assigning to memory 1192 also can. We just do this on all assignments to registers or 1193 memory, for simplicity's sake; I doubt the slowdown matters. */ 1194 switch (VALUE_LVAL (toval)) 1195 { 1196 case lval_memory: 1197 case lval_register: 1198 case lval_computed: 1199 1200 gdb::observers::target_changed.notify (current_top_target ()); 1201 1202 /* Having destroyed the frame cache, restore the selected 1203 frame. */ 1204 1205 /* FIXME: cagney/2002-11-02: There has to be a better way of 1206 doing this. Instead of constantly saving/restoring the 1207 frame. Why not create a get_selected_frame() function that, 1208 having saved the selected frame's ID can automatically 1209 re-find the previously selected frame automatically. */ 1210 1211 { 1212 struct frame_info *fi = frame_find_by_id (old_frame); 1213 1214 if (fi != NULL) 1215 select_frame (fi); 1216 } 1217 1218 break; 1219 default: 1220 break; 1221 } 1222 1223 /* If the field does not entirely fill a LONGEST, then zero the sign 1224 bits. If the field is signed, and is negative, then sign 1225 extend. */ 1226 if ((value_bitsize (toval) > 0) 1227 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST))) 1228 { 1229 LONGEST fieldval = value_as_long (fromval); 1230 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1; 1231 1232 fieldval &= valmask; 1233 if (!TYPE_UNSIGNED (type) 1234 && (fieldval & (valmask ^ (valmask >> 1)))) 1235 fieldval |= ~valmask; 1236 1237 fromval = value_from_longest (type, fieldval); 1238 } 1239 1240 /* The return value is a copy of TOVAL so it shares its location 1241 information, but its contents are updated from FROMVAL. This 1242 implies the returned value is not lazy, even if TOVAL was. */ 1243 val = value_copy (toval); 1244 set_value_lazy (val, 0); 1245 memcpy (value_contents_raw (val), value_contents (fromval), 1246 TYPE_LENGTH (type)); 1247 1248 /* We copy over the enclosing type and pointed-to offset from FROMVAL 1249 in the case of pointer types. For object types, the enclosing type 1250 and embedded offset must *not* be copied: the target object refered 1251 to by TOVAL retains its original dynamic type after assignment. */ 1252 if (type->code () == TYPE_CODE_PTR) 1253 { 1254 set_value_enclosing_type (val, value_enclosing_type (fromval)); 1255 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval)); 1256 } 1257 1258 return val; 1259 } 1260 1261 /* Extend a value VAL to COUNT repetitions of its type. */ 1262 1263 struct value * 1264 value_repeat (struct value *arg1, int count) 1265 { 1266 struct value *val; 1267 1268 if (VALUE_LVAL (arg1) != lval_memory) 1269 error (_("Only values in memory can be extended with '@'.")); 1270 if (count < 1) 1271 error (_("Invalid number %d of repetitions."), count); 1272 1273 val = allocate_repeat_value (value_enclosing_type (arg1), count); 1274 1275 VALUE_LVAL (val) = lval_memory; 1276 set_value_address (val, value_address (arg1)); 1277 1278 read_value_memory (val, 0, value_stack (val), value_address (val), 1279 value_contents_all_raw (val), 1280 type_length_units (value_enclosing_type (val))); 1281 1282 return val; 1283 } 1284 1285 struct value * 1286 value_of_variable (struct symbol *var, const struct block *b) 1287 { 1288 struct frame_info *frame = NULL; 1289 1290 if (symbol_read_needs_frame (var)) 1291 frame = get_selected_frame (_("No frame selected.")); 1292 1293 return read_var_value (var, b, frame); 1294 } 1295 1296 struct value * 1297 address_of_variable (struct symbol *var, const struct block *b) 1298 { 1299 struct type *type = SYMBOL_TYPE (var); 1300 struct value *val; 1301 1302 /* Evaluate it first; if the result is a memory address, we're fine. 1303 Lazy evaluation pays off here. */ 1304 1305 val = value_of_variable (var, b); 1306 type = value_type (val); 1307 1308 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val)) 1309 || type->code () == TYPE_CODE_FUNC) 1310 { 1311 CORE_ADDR addr = value_address (val); 1312 1313 return value_from_pointer (lookup_pointer_type (type), addr); 1314 } 1315 1316 /* Not a memory address; check what the problem was. */ 1317 switch (VALUE_LVAL (val)) 1318 { 1319 case lval_register: 1320 { 1321 struct frame_info *frame; 1322 const char *regname; 1323 1324 frame = frame_find_by_id (VALUE_NEXT_FRAME_ID (val)); 1325 gdb_assert (frame); 1326 1327 regname = gdbarch_register_name (get_frame_arch (frame), 1328 VALUE_REGNUM (val)); 1329 gdb_assert (regname && *regname); 1330 1331 error (_("Address requested for identifier " 1332 "\"%s\" which is in register $%s"), 1333 var->print_name (), regname); 1334 break; 1335 } 1336 1337 default: 1338 error (_("Can't take address of \"%s\" which isn't an lvalue."), 1339 var->print_name ()); 1340 break; 1341 } 1342 1343 return val; 1344 } 1345 1346 /* See value.h. */ 1347 1348 bool 1349 value_must_coerce_to_target (struct value *val) 1350 { 1351 struct type *valtype; 1352 1353 /* The only lval kinds which do not live in target memory. */ 1354 if (VALUE_LVAL (val) != not_lval 1355 && VALUE_LVAL (val) != lval_internalvar 1356 && VALUE_LVAL (val) != lval_xcallable) 1357 return false; 1358 1359 valtype = check_typedef (value_type (val)); 1360 1361 switch (valtype->code ()) 1362 { 1363 case TYPE_CODE_ARRAY: 1364 return TYPE_VECTOR (valtype) ? 0 : 1; 1365 case TYPE_CODE_STRING: 1366 return true; 1367 default: 1368 return false; 1369 } 1370 } 1371 1372 /* Make sure that VAL lives in target memory if it's supposed to. For 1373 instance, strings are constructed as character arrays in GDB's 1374 storage, and this function copies them to the target. */ 1375 1376 struct value * 1377 value_coerce_to_target (struct value *val) 1378 { 1379 LONGEST length; 1380 CORE_ADDR addr; 1381 1382 if (!value_must_coerce_to_target (val)) 1383 return val; 1384 1385 length = TYPE_LENGTH (check_typedef (value_type (val))); 1386 addr = allocate_space_in_inferior (length); 1387 write_memory (addr, value_contents (val), length); 1388 return value_at_lazy (value_type (val), addr); 1389 } 1390 1391 /* Given a value which is an array, return a value which is a pointer 1392 to its first element, regardless of whether or not the array has a 1393 nonzero lower bound. 1394 1395 FIXME: A previous comment here indicated that this routine should 1396 be substracting the array's lower bound. It's not clear to me that 1397 this is correct. Given an array subscripting operation, it would 1398 certainly work to do the adjustment here, essentially computing: 1399 1400 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0]) 1401 1402 However I believe a more appropriate and logical place to account 1403 for the lower bound is to do so in value_subscript, essentially 1404 computing: 1405 1406 (&array[0] + ((index - lowerbound) * sizeof array[0])) 1407 1408 As further evidence consider what would happen with operations 1409 other than array subscripting, where the caller would get back a 1410 value that had an address somewhere before the actual first element 1411 of the array, and the information about the lower bound would be 1412 lost because of the coercion to pointer type. */ 1413 1414 struct value * 1415 value_coerce_array (struct value *arg1) 1416 { 1417 struct type *type = check_typedef (value_type (arg1)); 1418 1419 /* If the user tries to do something requiring a pointer with an 1420 array that has not yet been pushed to the target, then this would 1421 be a good time to do so. */ 1422 arg1 = value_coerce_to_target (arg1); 1423 1424 if (VALUE_LVAL (arg1) != lval_memory) 1425 error (_("Attempt to take address of value not located in memory.")); 1426 1427 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)), 1428 value_address (arg1)); 1429 } 1430 1431 /* Given a value which is a function, return a value which is a pointer 1432 to it. */ 1433 1434 struct value * 1435 value_coerce_function (struct value *arg1) 1436 { 1437 struct value *retval; 1438 1439 if (VALUE_LVAL (arg1) != lval_memory) 1440 error (_("Attempt to take address of value not located in memory.")); 1441 1442 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)), 1443 value_address (arg1)); 1444 return retval; 1445 } 1446 1447 /* Return a pointer value for the object for which ARG1 is the 1448 contents. */ 1449 1450 struct value * 1451 value_addr (struct value *arg1) 1452 { 1453 struct value *arg2; 1454 struct type *type = check_typedef (value_type (arg1)); 1455 1456 if (TYPE_IS_REFERENCE (type)) 1457 { 1458 if (value_bits_synthetic_pointer (arg1, value_embedded_offset (arg1), 1459 TARGET_CHAR_BIT * TYPE_LENGTH (type))) 1460 arg1 = coerce_ref (arg1); 1461 else 1462 { 1463 /* Copy the value, but change the type from (T&) to (T*). We 1464 keep the same location information, which is efficient, and 1465 allows &(&X) to get the location containing the reference. 1466 Do the same to its enclosing type for consistency. */ 1467 struct type *type_ptr 1468 = lookup_pointer_type (TYPE_TARGET_TYPE (type)); 1469 struct type *enclosing_type 1470 = check_typedef (value_enclosing_type (arg1)); 1471 struct type *enclosing_type_ptr 1472 = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type)); 1473 1474 arg2 = value_copy (arg1); 1475 deprecated_set_value_type (arg2, type_ptr); 1476 set_value_enclosing_type (arg2, enclosing_type_ptr); 1477 1478 return arg2; 1479 } 1480 } 1481 if (type->code () == TYPE_CODE_FUNC) 1482 return value_coerce_function (arg1); 1483 1484 /* If this is an array that has not yet been pushed to the target, 1485 then this would be a good time to force it to memory. */ 1486 arg1 = value_coerce_to_target (arg1); 1487 1488 if (VALUE_LVAL (arg1) != lval_memory) 1489 error (_("Attempt to take address of value not located in memory.")); 1490 1491 /* Get target memory address. */ 1492 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)), 1493 (value_address (arg1) 1494 + value_embedded_offset (arg1))); 1495 1496 /* This may be a pointer to a base subobject; so remember the 1497 full derived object's type ... */ 1498 set_value_enclosing_type (arg2, 1499 lookup_pointer_type (value_enclosing_type (arg1))); 1500 /* ... and also the relative position of the subobject in the full 1501 object. */ 1502 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1)); 1503 return arg2; 1504 } 1505 1506 /* Return a reference value for the object for which ARG1 is the 1507 contents. */ 1508 1509 struct value * 1510 value_ref (struct value *arg1, enum type_code refcode) 1511 { 1512 struct value *arg2; 1513 struct type *type = check_typedef (value_type (arg1)); 1514 1515 gdb_assert (refcode == TYPE_CODE_REF || refcode == TYPE_CODE_RVALUE_REF); 1516 1517 if ((type->code () == TYPE_CODE_REF 1518 || type->code () == TYPE_CODE_RVALUE_REF) 1519 && type->code () == refcode) 1520 return arg1; 1521 1522 arg2 = value_addr (arg1); 1523 deprecated_set_value_type (arg2, lookup_reference_type (type, refcode)); 1524 return arg2; 1525 } 1526 1527 /* Given a value of a pointer type, apply the C unary * operator to 1528 it. */ 1529 1530 struct value * 1531 value_ind (struct value *arg1) 1532 { 1533 struct type *base_type; 1534 struct value *arg2; 1535 1536 arg1 = coerce_array (arg1); 1537 1538 base_type = check_typedef (value_type (arg1)); 1539 1540 if (VALUE_LVAL (arg1) == lval_computed) 1541 { 1542 const struct lval_funcs *funcs = value_computed_funcs (arg1); 1543 1544 if (funcs->indirect) 1545 { 1546 struct value *result = funcs->indirect (arg1); 1547 1548 if (result) 1549 return result; 1550 } 1551 } 1552 1553 if (base_type->code () == TYPE_CODE_PTR) 1554 { 1555 struct type *enc_type; 1556 1557 /* We may be pointing to something embedded in a larger object. 1558 Get the real type of the enclosing object. */ 1559 enc_type = check_typedef (value_enclosing_type (arg1)); 1560 enc_type = TYPE_TARGET_TYPE (enc_type); 1561 1562 CORE_ADDR base_addr; 1563 if (check_typedef (enc_type)->code () == TYPE_CODE_FUNC 1564 || check_typedef (enc_type)->code () == TYPE_CODE_METHOD) 1565 { 1566 /* For functions, go through find_function_addr, which knows 1567 how to handle function descriptors. */ 1568 base_addr = find_function_addr (arg1, NULL); 1569 } 1570 else 1571 { 1572 /* Retrieve the enclosing object pointed to. */ 1573 base_addr = (value_as_address (arg1) 1574 - value_pointed_to_offset (arg1)); 1575 } 1576 arg2 = value_at_lazy (enc_type, base_addr); 1577 enc_type = value_type (arg2); 1578 return readjust_indirect_value_type (arg2, enc_type, base_type, 1579 arg1, base_addr); 1580 } 1581 1582 error (_("Attempt to take contents of a non-pointer value.")); 1583 } 1584 1585 /* Create a value for an array by allocating space in GDB, copying the 1586 data into that space, and then setting up an array value. 1587 1588 The array bounds are set from LOWBOUND and HIGHBOUND, and the array 1589 is populated from the values passed in ELEMVEC. 1590 1591 The element type of the array is inherited from the type of the 1592 first element, and all elements must have the same size (though we 1593 don't currently enforce any restriction on their types). */ 1594 1595 struct value * 1596 value_array (int lowbound, int highbound, struct value **elemvec) 1597 { 1598 int nelem; 1599 int idx; 1600 ULONGEST typelength; 1601 struct value *val; 1602 struct type *arraytype; 1603 1604 /* Validate that the bounds are reasonable and that each of the 1605 elements have the same size. */ 1606 1607 nelem = highbound - lowbound + 1; 1608 if (nelem <= 0) 1609 { 1610 error (_("bad array bounds (%d, %d)"), lowbound, highbound); 1611 } 1612 typelength = type_length_units (value_enclosing_type (elemvec[0])); 1613 for (idx = 1; idx < nelem; idx++) 1614 { 1615 if (type_length_units (value_enclosing_type (elemvec[idx])) 1616 != typelength) 1617 { 1618 error (_("array elements must all be the same size")); 1619 } 1620 } 1621 1622 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]), 1623 lowbound, highbound); 1624 1625 if (!current_language->c_style_arrays) 1626 { 1627 val = allocate_value (arraytype); 1628 for (idx = 0; idx < nelem; idx++) 1629 value_contents_copy (val, idx * typelength, elemvec[idx], 0, 1630 typelength); 1631 return val; 1632 } 1633 1634 /* Allocate space to store the array, and then initialize it by 1635 copying in each element. */ 1636 1637 val = allocate_value (arraytype); 1638 for (idx = 0; idx < nelem; idx++) 1639 value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength); 1640 return val; 1641 } 1642 1643 struct value * 1644 value_cstring (const char *ptr, ssize_t len, struct type *char_type) 1645 { 1646 struct value *val; 1647 int lowbound = current_language->string_lower_bound; 1648 ssize_t highbound = len / TYPE_LENGTH (char_type); 1649 struct type *stringtype 1650 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1); 1651 1652 val = allocate_value (stringtype); 1653 memcpy (value_contents_raw (val), ptr, len); 1654 return val; 1655 } 1656 1657 /* Create a value for a string constant by allocating space in the 1658 inferior, copying the data into that space, and returning the 1659 address with type TYPE_CODE_STRING. PTR points to the string 1660 constant data; LEN is number of characters. 1661 1662 Note that string types are like array of char types with a lower 1663 bound of zero and an upper bound of LEN - 1. Also note that the 1664 string may contain embedded null bytes. */ 1665 1666 struct value * 1667 value_string (const char *ptr, ssize_t len, struct type *char_type) 1668 { 1669 struct value *val; 1670 int lowbound = current_language->string_lower_bound; 1671 ssize_t highbound = len / TYPE_LENGTH (char_type); 1672 struct type *stringtype 1673 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1); 1674 1675 val = allocate_value (stringtype); 1676 memcpy (value_contents_raw (val), ptr, len); 1677 return val; 1678 } 1679 1680 1681 /* See if we can pass arguments in T2 to a function which takes 1682 arguments of types T1. T1 is a list of NARGS arguments, and T2 is 1683 a NULL-terminated vector. If some arguments need coercion of some 1684 sort, then the coerced values are written into T2. Return value is 1685 0 if the arguments could be matched, or the position at which they 1686 differ if not. 1687 1688 STATICP is nonzero if the T1 argument list came from a static 1689 member function. T2 will still include the ``this'' pointer, but 1690 it will be skipped. 1691 1692 For non-static member functions, we ignore the first argument, 1693 which is the type of the instance variable. This is because we 1694 want to handle calls with objects from derived classes. This is 1695 not entirely correct: we should actually check to make sure that a 1696 requested operation is type secure, shouldn't we? FIXME. */ 1697 1698 static int 1699 typecmp (int staticp, int varargs, int nargs, 1700 struct field t1[], struct value *t2[]) 1701 { 1702 int i; 1703 1704 if (t2 == 0) 1705 internal_error (__FILE__, __LINE__, 1706 _("typecmp: no argument list")); 1707 1708 /* Skip ``this'' argument if applicable. T2 will always include 1709 THIS. */ 1710 if (staticp) 1711 t2 ++; 1712 1713 for (i = 0; 1714 (i < nargs) && t1[i].type ()->code () != TYPE_CODE_VOID; 1715 i++) 1716 { 1717 struct type *tt1, *tt2; 1718 1719 if (!t2[i]) 1720 return i + 1; 1721 1722 tt1 = check_typedef (t1[i].type ()); 1723 tt2 = check_typedef (value_type (t2[i])); 1724 1725 if (TYPE_IS_REFERENCE (tt1) 1726 /* We should be doing hairy argument matching, as below. */ 1727 && (check_typedef (TYPE_TARGET_TYPE (tt1))->code () 1728 == tt2->code ())) 1729 { 1730 if (tt2->code () == TYPE_CODE_ARRAY) 1731 t2[i] = value_coerce_array (t2[i]); 1732 else 1733 t2[i] = value_ref (t2[i], tt1->code ()); 1734 continue; 1735 } 1736 1737 /* djb - 20000715 - Until the new type structure is in the 1738 place, and we can attempt things like implicit conversions, 1739 we need to do this so you can take something like a map<const 1740 char *>, and properly access map["hello"], because the 1741 argument to [] will be a reference to a pointer to a char, 1742 and the argument will be a pointer to a char. */ 1743 while (TYPE_IS_REFERENCE (tt1) || tt1->code () == TYPE_CODE_PTR) 1744 { 1745 tt1 = check_typedef ( TYPE_TARGET_TYPE (tt1) ); 1746 } 1747 while (tt2->code () == TYPE_CODE_ARRAY 1748 || tt2->code () == TYPE_CODE_PTR 1749 || TYPE_IS_REFERENCE (tt2)) 1750 { 1751 tt2 = check_typedef (TYPE_TARGET_TYPE (tt2)); 1752 } 1753 if (tt1->code () == tt2->code ()) 1754 continue; 1755 /* Array to pointer is a `trivial conversion' according to the 1756 ARM. */ 1757 1758 /* We should be doing much hairier argument matching (see 1759 section 13.2 of the ARM), but as a quick kludge, just check 1760 for the same type code. */ 1761 if (t1[i].type ()->code () != value_type (t2[i])->code ()) 1762 return i + 1; 1763 } 1764 if (varargs || t2[i] == NULL) 1765 return 0; 1766 return i + 1; 1767 } 1768 1769 /* Helper class for do_search_struct_field that updates *RESULT_PTR 1770 and *LAST_BOFFSET, and possibly throws an exception if the field 1771 search has yielded ambiguous results. */ 1772 1773 static void 1774 update_search_result (struct value **result_ptr, struct value *v, 1775 LONGEST *last_boffset, LONGEST boffset, 1776 const char *name, struct type *type) 1777 { 1778 if (v != NULL) 1779 { 1780 if (*result_ptr != NULL 1781 /* The result is not ambiguous if all the classes that are 1782 found occupy the same space. */ 1783 && *last_boffset != boffset) 1784 error (_("base class '%s' is ambiguous in type '%s'"), 1785 name, TYPE_SAFE_NAME (type)); 1786 *result_ptr = v; 1787 *last_boffset = boffset; 1788 } 1789 } 1790 1791 /* A helper for search_struct_field. This does all the work; most 1792 arguments are as passed to search_struct_field. The result is 1793 stored in *RESULT_PTR, which must be initialized to NULL. 1794 OUTERMOST_TYPE is the type of the initial type passed to 1795 search_struct_field; this is used for error reporting when the 1796 lookup is ambiguous. */ 1797 1798 static void 1799 do_search_struct_field (const char *name, struct value *arg1, LONGEST offset, 1800 struct type *type, int looking_for_baseclass, 1801 struct value **result_ptr, 1802 LONGEST *last_boffset, 1803 struct type *outermost_type) 1804 { 1805 int i; 1806 int nbases; 1807 1808 type = check_typedef (type); 1809 nbases = TYPE_N_BASECLASSES (type); 1810 1811 if (!looking_for_baseclass) 1812 for (i = type->num_fields () - 1; i >= nbases; i--) 1813 { 1814 const char *t_field_name = TYPE_FIELD_NAME (type, i); 1815 1816 if (t_field_name && (strcmp_iw (t_field_name, name) == 0)) 1817 { 1818 struct value *v; 1819 1820 if (field_is_static (&type->field (i))) 1821 v = value_static_field (type, i); 1822 else 1823 v = value_primitive_field (arg1, offset, i, type); 1824 *result_ptr = v; 1825 return; 1826 } 1827 1828 if (t_field_name 1829 && t_field_name[0] == '\0') 1830 { 1831 struct type *field_type = type->field (i).type (); 1832 1833 if (field_type->code () == TYPE_CODE_UNION 1834 || field_type->code () == TYPE_CODE_STRUCT) 1835 { 1836 /* Look for a match through the fields of an anonymous 1837 union, or anonymous struct. C++ provides anonymous 1838 unions. 1839 1840 In the GNU Chill (now deleted from GDB) 1841 implementation of variant record types, each 1842 <alternative field> has an (anonymous) union type, 1843 each member of the union represents a <variant 1844 alternative>. Each <variant alternative> is 1845 represented as a struct, with a member for each 1846 <variant field>. */ 1847 1848 struct value *v = NULL; 1849 LONGEST new_offset = offset; 1850 1851 /* This is pretty gross. In G++, the offset in an 1852 anonymous union is relative to the beginning of the 1853 enclosing struct. In the GNU Chill (now deleted 1854 from GDB) implementation of variant records, the 1855 bitpos is zero in an anonymous union field, so we 1856 have to add the offset of the union here. */ 1857 if (field_type->code () == TYPE_CODE_STRUCT 1858 || (field_type->num_fields () > 0 1859 && TYPE_FIELD_BITPOS (field_type, 0) == 0)) 1860 new_offset += TYPE_FIELD_BITPOS (type, i) / 8; 1861 1862 do_search_struct_field (name, arg1, new_offset, 1863 field_type, 1864 looking_for_baseclass, &v, 1865 last_boffset, 1866 outermost_type); 1867 if (v) 1868 { 1869 *result_ptr = v; 1870 return; 1871 } 1872 } 1873 } 1874 } 1875 1876 for (i = 0; i < nbases; i++) 1877 { 1878 struct value *v = NULL; 1879 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i)); 1880 /* If we are looking for baseclasses, this is what we get when 1881 we hit them. But it could happen that the base part's member 1882 name is not yet filled in. */ 1883 int found_baseclass = (looking_for_baseclass 1884 && TYPE_BASECLASS_NAME (type, i) != NULL 1885 && (strcmp_iw (name, 1886 TYPE_BASECLASS_NAME (type, 1887 i)) == 0)); 1888 LONGEST boffset = value_embedded_offset (arg1) + offset; 1889 1890 if (BASETYPE_VIA_VIRTUAL (type, i)) 1891 { 1892 struct value *v2; 1893 1894 boffset = baseclass_offset (type, i, 1895 value_contents_for_printing (arg1), 1896 value_embedded_offset (arg1) + offset, 1897 value_address (arg1), 1898 arg1); 1899 1900 /* The virtual base class pointer might have been clobbered 1901 by the user program. Make sure that it still points to a 1902 valid memory location. */ 1903 1904 boffset += value_embedded_offset (arg1) + offset; 1905 if (boffset < 0 1906 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1))) 1907 { 1908 CORE_ADDR base_addr; 1909 1910 base_addr = value_address (arg1) + boffset; 1911 v2 = value_at_lazy (basetype, base_addr); 1912 if (target_read_memory (base_addr, 1913 value_contents_raw (v2), 1914 TYPE_LENGTH (value_type (v2))) != 0) 1915 error (_("virtual baseclass botch")); 1916 } 1917 else 1918 { 1919 v2 = value_copy (arg1); 1920 deprecated_set_value_type (v2, basetype); 1921 set_value_embedded_offset (v2, boffset); 1922 } 1923 1924 if (found_baseclass) 1925 v = v2; 1926 else 1927 { 1928 do_search_struct_field (name, v2, 0, 1929 TYPE_BASECLASS (type, i), 1930 looking_for_baseclass, 1931 result_ptr, last_boffset, 1932 outermost_type); 1933 } 1934 } 1935 else if (found_baseclass) 1936 v = value_primitive_field (arg1, offset, i, type); 1937 else 1938 { 1939 do_search_struct_field (name, arg1, 1940 offset + TYPE_BASECLASS_BITPOS (type, 1941 i) / 8, 1942 basetype, looking_for_baseclass, 1943 result_ptr, last_boffset, 1944 outermost_type); 1945 } 1946 1947 update_search_result (result_ptr, v, last_boffset, 1948 boffset, name, outermost_type); 1949 } 1950 } 1951 1952 /* Helper function used by value_struct_elt to recurse through 1953 baseclasses. Look for a field NAME in ARG1. Search in it assuming 1954 it has (class) type TYPE. If found, return value, else return NULL. 1955 1956 If LOOKING_FOR_BASECLASS, then instead of looking for struct 1957 fields, look for a baseclass named NAME. */ 1958 1959 static struct value * 1960 search_struct_field (const char *name, struct value *arg1, 1961 struct type *type, int looking_for_baseclass) 1962 { 1963 struct value *result = NULL; 1964 LONGEST boffset = 0; 1965 1966 do_search_struct_field (name, arg1, 0, type, looking_for_baseclass, 1967 &result, &boffset, type); 1968 return result; 1969 } 1970 1971 /* Helper function used by value_struct_elt to recurse through 1972 baseclasses. Look for a field NAME in ARG1. Adjust the address of 1973 ARG1 by OFFSET bytes, and search in it assuming it has (class) type 1974 TYPE. 1975 1976 If found, return value, else if name matched and args not return 1977 (value) -1, else return NULL. */ 1978 1979 static struct value * 1980 search_struct_method (const char *name, struct value **arg1p, 1981 struct value **args, LONGEST offset, 1982 int *static_memfuncp, struct type *type) 1983 { 1984 int i; 1985 struct value *v; 1986 int name_matched = 0; 1987 1988 type = check_typedef (type); 1989 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--) 1990 { 1991 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i); 1992 1993 if (t_field_name && (strcmp_iw (t_field_name, name) == 0)) 1994 { 1995 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1; 1996 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i); 1997 1998 name_matched = 1; 1999 check_stub_method_group (type, i); 2000 if (j > 0 && args == 0) 2001 error (_("cannot resolve overloaded method " 2002 "`%s': no arguments supplied"), name); 2003 else if (j == 0 && args == 0) 2004 { 2005 v = value_fn_field (arg1p, f, j, type, offset); 2006 if (v != NULL) 2007 return v; 2008 } 2009 else 2010 while (j >= 0) 2011 { 2012 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j), 2013 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)), 2014 TYPE_FN_FIELD_TYPE (f, j)->num_fields (), 2015 TYPE_FN_FIELD_ARGS (f, j), args)) 2016 { 2017 if (TYPE_FN_FIELD_VIRTUAL_P (f, j)) 2018 return value_virtual_fn_field (arg1p, f, j, 2019 type, offset); 2020 if (TYPE_FN_FIELD_STATIC_P (f, j) 2021 && static_memfuncp) 2022 *static_memfuncp = 1; 2023 v = value_fn_field (arg1p, f, j, type, offset); 2024 if (v != NULL) 2025 return v; 2026 } 2027 j--; 2028 } 2029 } 2030 } 2031 2032 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--) 2033 { 2034 LONGEST base_offset; 2035 LONGEST this_offset; 2036 2037 if (BASETYPE_VIA_VIRTUAL (type, i)) 2038 { 2039 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i)); 2040 struct value *base_val; 2041 const gdb_byte *base_valaddr; 2042 2043 /* The virtual base class pointer might have been 2044 clobbered by the user program. Make sure that it 2045 still points to a valid memory location. */ 2046 2047 if (offset < 0 || offset >= TYPE_LENGTH (type)) 2048 { 2049 CORE_ADDR address; 2050 2051 gdb::byte_vector tmp (TYPE_LENGTH (baseclass)); 2052 address = value_address (*arg1p); 2053 2054 if (target_read_memory (address + offset, 2055 tmp.data (), TYPE_LENGTH (baseclass)) != 0) 2056 error (_("virtual baseclass botch")); 2057 2058 base_val = value_from_contents_and_address (baseclass, 2059 tmp.data (), 2060 address + offset); 2061 base_valaddr = value_contents_for_printing (base_val); 2062 this_offset = 0; 2063 } 2064 else 2065 { 2066 base_val = *arg1p; 2067 base_valaddr = value_contents_for_printing (*arg1p); 2068 this_offset = offset; 2069 } 2070 2071 base_offset = baseclass_offset (type, i, base_valaddr, 2072 this_offset, value_address (base_val), 2073 base_val); 2074 } 2075 else 2076 { 2077 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8; 2078 } 2079 v = search_struct_method (name, arg1p, args, base_offset + offset, 2080 static_memfuncp, TYPE_BASECLASS (type, i)); 2081 if (v == (struct value *) - 1) 2082 { 2083 name_matched = 1; 2084 } 2085 else if (v) 2086 { 2087 /* FIXME-bothner: Why is this commented out? Why is it here? */ 2088 /* *arg1p = arg1_tmp; */ 2089 return v; 2090 } 2091 } 2092 if (name_matched) 2093 return (struct value *) - 1; 2094 else 2095 return NULL; 2096 } 2097 2098 /* Given *ARGP, a value of type (pointer to a)* structure/union, 2099 extract the component named NAME from the ultimate target 2100 structure/union and return it as a value with its appropriate type. 2101 ERR is used in the error message if *ARGP's type is wrong. 2102 2103 C++: ARGS is a list of argument types to aid in the selection of 2104 an appropriate method. Also, handle derived types. 2105 2106 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location 2107 where the truthvalue of whether the function that was resolved was 2108 a static member function or not is stored. 2109 2110 ERR is an error message to be printed in case the field is not 2111 found. */ 2112 2113 struct value * 2114 value_struct_elt (struct value **argp, struct value **args, 2115 const char *name, int *static_memfuncp, const char *err) 2116 { 2117 struct type *t; 2118 struct value *v; 2119 2120 *argp = coerce_array (*argp); 2121 2122 t = check_typedef (value_type (*argp)); 2123 2124 /* Follow pointers until we get to a non-pointer. */ 2125 2126 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t)) 2127 { 2128 *argp = value_ind (*argp); 2129 /* Don't coerce fn pointer to fn and then back again! */ 2130 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC) 2131 *argp = coerce_array (*argp); 2132 t = check_typedef (value_type (*argp)); 2133 } 2134 2135 if (t->code () != TYPE_CODE_STRUCT 2136 && t->code () != TYPE_CODE_UNION) 2137 error (_("Attempt to extract a component of a value that is not a %s."), 2138 err); 2139 2140 /* Assume it's not, unless we see that it is. */ 2141 if (static_memfuncp) 2142 *static_memfuncp = 0; 2143 2144 if (!args) 2145 { 2146 /* if there are no arguments ...do this... */ 2147 2148 /* Try as a field first, because if we succeed, there is less 2149 work to be done. */ 2150 v = search_struct_field (name, *argp, t, 0); 2151 if (v) 2152 return v; 2153 2154 /* C++: If it was not found as a data field, then try to 2155 return it as a pointer to a method. */ 2156 v = search_struct_method (name, argp, args, 0, 2157 static_memfuncp, t); 2158 2159 if (v == (struct value *) - 1) 2160 error (_("Cannot take address of method %s."), name); 2161 else if (v == 0) 2162 { 2163 if (TYPE_NFN_FIELDS (t)) 2164 error (_("There is no member or method named %s."), name); 2165 else 2166 error (_("There is no member named %s."), name); 2167 } 2168 return v; 2169 } 2170 2171 v = search_struct_method (name, argp, args, 0, 2172 static_memfuncp, t); 2173 2174 if (v == (struct value *) - 1) 2175 { 2176 error (_("One of the arguments you tried to pass to %s could not " 2177 "be converted to what the function wants."), name); 2178 } 2179 else if (v == 0) 2180 { 2181 /* See if user tried to invoke data as function. If so, hand it 2182 back. If it's not callable (i.e., a pointer to function), 2183 gdb should give an error. */ 2184 v = search_struct_field (name, *argp, t, 0); 2185 /* If we found an ordinary field, then it is not a method call. 2186 So, treat it as if it were a static member function. */ 2187 if (v && static_memfuncp) 2188 *static_memfuncp = 1; 2189 } 2190 2191 if (!v) 2192 throw_error (NOT_FOUND_ERROR, 2193 _("Structure has no component named %s."), name); 2194 return v; 2195 } 2196 2197 /* Given *ARGP, a value of type structure or union, or a pointer/reference 2198 to a structure or union, extract and return its component (field) of 2199 type FTYPE at the specified BITPOS. 2200 Throw an exception on error. */ 2201 2202 struct value * 2203 value_struct_elt_bitpos (struct value **argp, int bitpos, struct type *ftype, 2204 const char *err) 2205 { 2206 struct type *t; 2207 int i; 2208 2209 *argp = coerce_array (*argp); 2210 2211 t = check_typedef (value_type (*argp)); 2212 2213 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t)) 2214 { 2215 *argp = value_ind (*argp); 2216 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC) 2217 *argp = coerce_array (*argp); 2218 t = check_typedef (value_type (*argp)); 2219 } 2220 2221 if (t->code () != TYPE_CODE_STRUCT 2222 && t->code () != TYPE_CODE_UNION) 2223 error (_("Attempt to extract a component of a value that is not a %s."), 2224 err); 2225 2226 for (i = TYPE_N_BASECLASSES (t); i < t->num_fields (); i++) 2227 { 2228 if (!field_is_static (&t->field (i)) 2229 && bitpos == TYPE_FIELD_BITPOS (t, i) 2230 && types_equal (ftype, t->field (i).type ())) 2231 return value_primitive_field (*argp, 0, i, t); 2232 } 2233 2234 error (_("No field with matching bitpos and type.")); 2235 2236 /* Never hit. */ 2237 return NULL; 2238 } 2239 2240 /* Search through the methods of an object (and its bases) to find a 2241 specified method. Return a reference to the fn_field list METHODS of 2242 overloaded instances defined in the source language. If available 2243 and matching, a vector of matching xmethods defined in extension 2244 languages are also returned in XMETHODS. 2245 2246 Helper function for value_find_oload_list. 2247 ARGP is a pointer to a pointer to a value (the object). 2248 METHOD is a string containing the method name. 2249 OFFSET is the offset within the value. 2250 TYPE is the assumed type of the object. 2251 METHODS is a pointer to the matching overloaded instances defined 2252 in the source language. Since this is a recursive function, 2253 *METHODS should be set to NULL when calling this function. 2254 NUM_FNS is the number of overloaded instances. *NUM_FNS should be set to 2255 0 when calling this function. 2256 XMETHODS is the vector of matching xmethod workers. *XMETHODS 2257 should also be set to NULL when calling this function. 2258 BASETYPE is set to the actual type of the subobject where the 2259 method is found. 2260 BOFFSET is the offset of the base subobject where the method is found. */ 2261 2262 static void 2263 find_method_list (struct value **argp, const char *method, 2264 LONGEST offset, struct type *type, 2265 gdb::array_view<fn_field> *methods, 2266 std::vector<xmethod_worker_up> *xmethods, 2267 struct type **basetype, LONGEST *boffset) 2268 { 2269 int i; 2270 struct fn_field *f = NULL; 2271 2272 gdb_assert (methods != NULL && xmethods != NULL); 2273 type = check_typedef (type); 2274 2275 /* First check in object itself. 2276 This function is called recursively to search through base classes. 2277 If there is a source method match found at some stage, then we need not 2278 look for source methods in consequent recursive calls. */ 2279 if (methods->empty ()) 2280 { 2281 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--) 2282 { 2283 /* pai: FIXME What about operators and type conversions? */ 2284 const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i); 2285 2286 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0)) 2287 { 2288 int len = TYPE_FN_FIELDLIST_LENGTH (type, i); 2289 f = TYPE_FN_FIELDLIST1 (type, i); 2290 *methods = gdb::make_array_view (f, len); 2291 2292 *basetype = type; 2293 *boffset = offset; 2294 2295 /* Resolve any stub methods. */ 2296 check_stub_method_group (type, i); 2297 2298 break; 2299 } 2300 } 2301 } 2302 2303 /* Unlike source methods, xmethods can be accumulated over successive 2304 recursive calls. In other words, an xmethod named 'm' in a class 2305 will not hide an xmethod named 'm' in its base class(es). We want 2306 it to be this way because xmethods are after all convenience functions 2307 and hence there is no point restricting them with something like method 2308 hiding. Moreover, if hiding is done for xmethods as well, then we will 2309 have to provide a mechanism to un-hide (like the 'using' construct). */ 2310 get_matching_xmethod_workers (type, method, xmethods); 2311 2312 /* If source methods are not found in current class, look for them in the 2313 base classes. We also have to go through the base classes to gather 2314 extension methods. */ 2315 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--) 2316 { 2317 LONGEST base_offset; 2318 2319 if (BASETYPE_VIA_VIRTUAL (type, i)) 2320 { 2321 base_offset = baseclass_offset (type, i, 2322 value_contents_for_printing (*argp), 2323 value_offset (*argp) + offset, 2324 value_address (*argp), *argp); 2325 } 2326 else /* Non-virtual base, simply use bit position from debug 2327 info. */ 2328 { 2329 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8; 2330 } 2331 2332 find_method_list (argp, method, base_offset + offset, 2333 TYPE_BASECLASS (type, i), methods, 2334 xmethods, basetype, boffset); 2335 } 2336 } 2337 2338 /* Return the list of overloaded methods of a specified name. The methods 2339 could be those GDB finds in the binary, or xmethod. Methods found in 2340 the binary are returned in METHODS, and xmethods are returned in 2341 XMETHODS. 2342 2343 ARGP is a pointer to a pointer to a value (the object). 2344 METHOD is the method name. 2345 OFFSET is the offset within the value contents. 2346 METHODS is the list of matching overloaded instances defined in 2347 the source language. 2348 XMETHODS is the vector of matching xmethod workers defined in 2349 extension languages. 2350 BASETYPE is set to the type of the base subobject that defines the 2351 method. 2352 BOFFSET is the offset of the base subobject which defines the method. */ 2353 2354 static void 2355 value_find_oload_method_list (struct value **argp, const char *method, 2356 LONGEST offset, 2357 gdb::array_view<fn_field> *methods, 2358 std::vector<xmethod_worker_up> *xmethods, 2359 struct type **basetype, LONGEST *boffset) 2360 { 2361 struct type *t; 2362 2363 t = check_typedef (value_type (*argp)); 2364 2365 /* Code snarfed from value_struct_elt. */ 2366 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t)) 2367 { 2368 *argp = value_ind (*argp); 2369 /* Don't coerce fn pointer to fn and then back again! */ 2370 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC) 2371 *argp = coerce_array (*argp); 2372 t = check_typedef (value_type (*argp)); 2373 } 2374 2375 if (t->code () != TYPE_CODE_STRUCT 2376 && t->code () != TYPE_CODE_UNION) 2377 error (_("Attempt to extract a component of a " 2378 "value that is not a struct or union")); 2379 2380 gdb_assert (methods != NULL && xmethods != NULL); 2381 2382 /* Clear the lists. */ 2383 *methods = {}; 2384 xmethods->clear (); 2385 2386 find_method_list (argp, method, 0, t, methods, xmethods, 2387 basetype, boffset); 2388 } 2389 2390 /* Given an array of arguments (ARGS) (which includes an entry for 2391 "this" in the case of C++ methods), the NAME of a function, and 2392 whether it's a method or not (METHOD), find the best function that 2393 matches on the argument types according to the overload resolution 2394 rules. 2395 2396 METHOD can be one of three values: 2397 NON_METHOD for non-member functions. 2398 METHOD: for member functions. 2399 BOTH: used for overload resolution of operators where the 2400 candidates are expected to be either member or non member 2401 functions. In this case the first argument ARGTYPES 2402 (representing 'this') is expected to be a reference to the 2403 target object, and will be dereferenced when attempting the 2404 non-member search. 2405 2406 In the case of class methods, the parameter OBJ is an object value 2407 in which to search for overloaded methods. 2408 2409 In the case of non-method functions, the parameter FSYM is a symbol 2410 corresponding to one of the overloaded functions. 2411 2412 Return value is an integer: 0 -> good match, 10 -> debugger applied 2413 non-standard coercions, 100 -> incompatible. 2414 2415 If a method is being searched for, VALP will hold the value. 2416 If a non-method is being searched for, SYMP will hold the symbol 2417 for it. 2418 2419 If a method is being searched for, and it is a static method, 2420 then STATICP will point to a non-zero value. 2421 2422 If NO_ADL argument dependent lookup is disabled. This is used to prevent 2423 ADL overload candidates when performing overload resolution for a fully 2424 qualified name. 2425 2426 If NOSIDE is EVAL_AVOID_SIDE_EFFECTS, then OBJP's memory cannot be 2427 read while picking the best overload match (it may be all zeroes and thus 2428 not have a vtable pointer), in which case skip virtual function lookup. 2429 This is ok as typically EVAL_AVOID_SIDE_EFFECTS is only used to determine 2430 the result type. 2431 2432 Note: This function does *not* check the value of 2433 overload_resolution. Caller must check it to see whether overload 2434 resolution is permitted. */ 2435 2436 int 2437 find_overload_match (gdb::array_view<value *> args, 2438 const char *name, enum oload_search_type method, 2439 struct value **objp, struct symbol *fsym, 2440 struct value **valp, struct symbol **symp, 2441 int *staticp, const int no_adl, 2442 const enum noside noside) 2443 { 2444 struct value *obj = (objp ? *objp : NULL); 2445 struct type *obj_type = obj ? value_type (obj) : NULL; 2446 /* Index of best overloaded function. */ 2447 int func_oload_champ = -1; 2448 int method_oload_champ = -1; 2449 int src_method_oload_champ = -1; 2450 int ext_method_oload_champ = -1; 2451 2452 /* The measure for the current best match. */ 2453 badness_vector method_badness; 2454 badness_vector func_badness; 2455 badness_vector ext_method_badness; 2456 badness_vector src_method_badness; 2457 2458 struct value *temp = obj; 2459 /* For methods, the list of overloaded methods. */ 2460 gdb::array_view<fn_field> methods; 2461 /* For non-methods, the list of overloaded function symbols. */ 2462 std::vector<symbol *> functions; 2463 /* For xmethods, the vector of xmethod workers. */ 2464 std::vector<xmethod_worker_up> xmethods; 2465 struct type *basetype = NULL; 2466 LONGEST boffset; 2467 2468 const char *obj_type_name = NULL; 2469 const char *func_name = NULL; 2470 gdb::unique_xmalloc_ptr<char> temp_func; 2471 enum oload_classification match_quality; 2472 enum oload_classification method_match_quality = INCOMPATIBLE; 2473 enum oload_classification src_method_match_quality = INCOMPATIBLE; 2474 enum oload_classification ext_method_match_quality = INCOMPATIBLE; 2475 enum oload_classification func_match_quality = INCOMPATIBLE; 2476 2477 /* Get the list of overloaded methods or functions. */ 2478 if (method == METHOD || method == BOTH) 2479 { 2480 gdb_assert (obj); 2481 2482 /* OBJ may be a pointer value rather than the object itself. */ 2483 obj = coerce_ref (obj); 2484 while (check_typedef (value_type (obj))->code () == TYPE_CODE_PTR) 2485 obj = coerce_ref (value_ind (obj)); 2486 obj_type_name = value_type (obj)->name (); 2487 2488 /* First check whether this is a data member, e.g. a pointer to 2489 a function. */ 2490 if (check_typedef (value_type (obj))->code () == TYPE_CODE_STRUCT) 2491 { 2492 *valp = search_struct_field (name, obj, 2493 check_typedef (value_type (obj)), 0); 2494 if (*valp) 2495 { 2496 *staticp = 1; 2497 return 0; 2498 } 2499 } 2500 2501 /* Retrieve the list of methods with the name NAME. */ 2502 value_find_oload_method_list (&temp, name, 0, &methods, 2503 &xmethods, &basetype, &boffset); 2504 /* If this is a method only search, and no methods were found 2505 the search has failed. */ 2506 if (method == METHOD && methods.empty () && xmethods.empty ()) 2507 error (_("Couldn't find method %s%s%s"), 2508 obj_type_name, 2509 (obj_type_name && *obj_type_name) ? "::" : "", 2510 name); 2511 /* If we are dealing with stub method types, they should have 2512 been resolved by find_method_list via 2513 value_find_oload_method_list above. */ 2514 if (!methods.empty ()) 2515 { 2516 gdb_assert (TYPE_SELF_TYPE (methods[0].type) != NULL); 2517 2518 src_method_oload_champ 2519 = find_oload_champ (args, 2520 methods.size (), 2521 methods.data (), NULL, NULL, 2522 &src_method_badness); 2523 2524 src_method_match_quality = classify_oload_match 2525 (src_method_badness, args.size (), 2526 oload_method_static_p (methods.data (), src_method_oload_champ)); 2527 } 2528 2529 if (!xmethods.empty ()) 2530 { 2531 ext_method_oload_champ 2532 = find_oload_champ (args, 2533 xmethods.size (), 2534 NULL, xmethods.data (), NULL, 2535 &ext_method_badness); 2536 ext_method_match_quality = classify_oload_match (ext_method_badness, 2537 args.size (), 0); 2538 } 2539 2540 if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0) 2541 { 2542 switch (compare_badness (ext_method_badness, src_method_badness)) 2543 { 2544 case 0: /* Src method and xmethod are equally good. */ 2545 /* If src method and xmethod are equally good, then 2546 xmethod should be the winner. Hence, fall through to the 2547 case where a xmethod is better than the source 2548 method, except when the xmethod match quality is 2549 non-standard. */ 2550 /* FALLTHROUGH */ 2551 case 1: /* Src method and ext method are incompatible. */ 2552 /* If ext method match is not standard, then let source method 2553 win. Otherwise, fallthrough to let xmethod win. */ 2554 if (ext_method_match_quality != STANDARD) 2555 { 2556 method_oload_champ = src_method_oload_champ; 2557 method_badness = src_method_badness; 2558 ext_method_oload_champ = -1; 2559 method_match_quality = src_method_match_quality; 2560 break; 2561 } 2562 /* FALLTHROUGH */ 2563 case 2: /* Ext method is champion. */ 2564 method_oload_champ = ext_method_oload_champ; 2565 method_badness = ext_method_badness; 2566 src_method_oload_champ = -1; 2567 method_match_quality = ext_method_match_quality; 2568 break; 2569 case 3: /* Src method is champion. */ 2570 method_oload_champ = src_method_oload_champ; 2571 method_badness = src_method_badness; 2572 ext_method_oload_champ = -1; 2573 method_match_quality = src_method_match_quality; 2574 break; 2575 default: 2576 gdb_assert_not_reached ("Unexpected overload comparison " 2577 "result"); 2578 break; 2579 } 2580 } 2581 else if (src_method_oload_champ >= 0) 2582 { 2583 method_oload_champ = src_method_oload_champ; 2584 method_badness = src_method_badness; 2585 method_match_quality = src_method_match_quality; 2586 } 2587 else if (ext_method_oload_champ >= 0) 2588 { 2589 method_oload_champ = ext_method_oload_champ; 2590 method_badness = ext_method_badness; 2591 method_match_quality = ext_method_match_quality; 2592 } 2593 } 2594 2595 if (method == NON_METHOD || method == BOTH) 2596 { 2597 const char *qualified_name = NULL; 2598 2599 /* If the overload match is being search for both as a method 2600 and non member function, the first argument must now be 2601 dereferenced. */ 2602 if (method == BOTH) 2603 args[0] = value_ind (args[0]); 2604 2605 if (fsym) 2606 { 2607 qualified_name = fsym->natural_name (); 2608 2609 /* If we have a function with a C++ name, try to extract just 2610 the function part. Do not try this for non-functions (e.g. 2611 function pointers). */ 2612 if (qualified_name 2613 && (check_typedef (SYMBOL_TYPE (fsym))->code () 2614 == TYPE_CODE_FUNC)) 2615 { 2616 temp_func = cp_func_name (qualified_name); 2617 2618 /* If cp_func_name did not remove anything, the name of the 2619 symbol did not include scope or argument types - it was 2620 probably a C-style function. */ 2621 if (temp_func != nullptr) 2622 { 2623 if (strcmp (temp_func.get (), qualified_name) == 0) 2624 func_name = NULL; 2625 else 2626 func_name = temp_func.get (); 2627 } 2628 } 2629 } 2630 else 2631 { 2632 func_name = name; 2633 qualified_name = name; 2634 } 2635 2636 /* If there was no C++ name, this must be a C-style function or 2637 not a function at all. Just return the same symbol. Do the 2638 same if cp_func_name fails for some reason. */ 2639 if (func_name == NULL) 2640 { 2641 *symp = fsym; 2642 return 0; 2643 } 2644 2645 func_oload_champ = find_oload_champ_namespace (args, 2646 func_name, 2647 qualified_name, 2648 &functions, 2649 &func_badness, 2650 no_adl); 2651 2652 if (func_oload_champ >= 0) 2653 func_match_quality = classify_oload_match (func_badness, 2654 args.size (), 0); 2655 } 2656 2657 /* Did we find a match ? */ 2658 if (method_oload_champ == -1 && func_oload_champ == -1) 2659 throw_error (NOT_FOUND_ERROR, 2660 _("No symbol \"%s\" in current context."), 2661 name); 2662 2663 /* If we have found both a method match and a function 2664 match, find out which one is better, and calculate match 2665 quality. */ 2666 if (method_oload_champ >= 0 && func_oload_champ >= 0) 2667 { 2668 switch (compare_badness (func_badness, method_badness)) 2669 { 2670 case 0: /* Top two contenders are equally good. */ 2671 /* FIXME: GDB does not support the general ambiguous case. 2672 All candidates should be collected and presented the 2673 user. */ 2674 error (_("Ambiguous overload resolution")); 2675 break; 2676 case 1: /* Incomparable top contenders. */ 2677 /* This is an error incompatible candidates 2678 should not have been proposed. */ 2679 error (_("Internal error: incompatible " 2680 "overload candidates proposed")); 2681 break; 2682 case 2: /* Function champion. */ 2683 method_oload_champ = -1; 2684 match_quality = func_match_quality; 2685 break; 2686 case 3: /* Method champion. */ 2687 func_oload_champ = -1; 2688 match_quality = method_match_quality; 2689 break; 2690 default: 2691 error (_("Internal error: unexpected overload comparison result")); 2692 break; 2693 } 2694 } 2695 else 2696 { 2697 /* We have either a method match or a function match. */ 2698 if (method_oload_champ >= 0) 2699 match_quality = method_match_quality; 2700 else 2701 match_quality = func_match_quality; 2702 } 2703 2704 if (match_quality == INCOMPATIBLE) 2705 { 2706 if (method == METHOD) 2707 error (_("Cannot resolve method %s%s%s to any overloaded instance"), 2708 obj_type_name, 2709 (obj_type_name && *obj_type_name) ? "::" : "", 2710 name); 2711 else 2712 error (_("Cannot resolve function %s to any overloaded instance"), 2713 func_name); 2714 } 2715 else if (match_quality == NON_STANDARD) 2716 { 2717 if (method == METHOD) 2718 warning (_("Using non-standard conversion to match " 2719 "method %s%s%s to supplied arguments"), 2720 obj_type_name, 2721 (obj_type_name && *obj_type_name) ? "::" : "", 2722 name); 2723 else 2724 warning (_("Using non-standard conversion to match " 2725 "function %s to supplied arguments"), 2726 func_name); 2727 } 2728 2729 if (staticp != NULL) 2730 *staticp = oload_method_static_p (methods.data (), method_oload_champ); 2731 2732 if (method_oload_champ >= 0) 2733 { 2734 if (src_method_oload_champ >= 0) 2735 { 2736 if (TYPE_FN_FIELD_VIRTUAL_P (methods, method_oload_champ) 2737 && noside != EVAL_AVOID_SIDE_EFFECTS) 2738 { 2739 *valp = value_virtual_fn_field (&temp, methods.data (), 2740 method_oload_champ, basetype, 2741 boffset); 2742 } 2743 else 2744 *valp = value_fn_field (&temp, methods.data (), 2745 method_oload_champ, basetype, boffset); 2746 } 2747 else 2748 *valp = value_from_xmethod 2749 (std::move (xmethods[ext_method_oload_champ])); 2750 } 2751 else 2752 *symp = functions[func_oload_champ]; 2753 2754 if (objp) 2755 { 2756 struct type *temp_type = check_typedef (value_type (temp)); 2757 struct type *objtype = check_typedef (obj_type); 2758 2759 if (temp_type->code () != TYPE_CODE_PTR 2760 && (objtype->code () == TYPE_CODE_PTR 2761 || TYPE_IS_REFERENCE (objtype))) 2762 { 2763 temp = value_addr (temp); 2764 } 2765 *objp = temp; 2766 } 2767 2768 switch (match_quality) 2769 { 2770 case INCOMPATIBLE: 2771 return 100; 2772 case NON_STANDARD: 2773 return 10; 2774 default: /* STANDARD */ 2775 return 0; 2776 } 2777 } 2778 2779 /* Find the best overload match, searching for FUNC_NAME in namespaces 2780 contained in QUALIFIED_NAME until it either finds a good match or 2781 runs out of namespaces. It stores the overloaded functions in 2782 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. If NO_ADL, 2783 argument dependent lookup is not performed. */ 2784 2785 static int 2786 find_oload_champ_namespace (gdb::array_view<value *> args, 2787 const char *func_name, 2788 const char *qualified_name, 2789 std::vector<symbol *> *oload_syms, 2790 badness_vector *oload_champ_bv, 2791 const int no_adl) 2792 { 2793 int oload_champ; 2794 2795 find_oload_champ_namespace_loop (args, 2796 func_name, 2797 qualified_name, 0, 2798 oload_syms, oload_champ_bv, 2799 &oload_champ, 2800 no_adl); 2801 2802 return oload_champ; 2803 } 2804 2805 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is 2806 how deep we've looked for namespaces, and the champ is stored in 2807 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0 2808 if it isn't. Other arguments are the same as in 2809 find_oload_champ_namespace. */ 2810 2811 static int 2812 find_oload_champ_namespace_loop (gdb::array_view<value *> args, 2813 const char *func_name, 2814 const char *qualified_name, 2815 int namespace_len, 2816 std::vector<symbol *> *oload_syms, 2817 badness_vector *oload_champ_bv, 2818 int *oload_champ, 2819 const int no_adl) 2820 { 2821 int next_namespace_len = namespace_len; 2822 int searched_deeper = 0; 2823 int new_oload_champ; 2824 char *new_namespace; 2825 2826 if (next_namespace_len != 0) 2827 { 2828 gdb_assert (qualified_name[next_namespace_len] == ':'); 2829 next_namespace_len += 2; 2830 } 2831 next_namespace_len += 2832 cp_find_first_component (qualified_name + next_namespace_len); 2833 2834 /* First, see if we have a deeper namespace we can search in. 2835 If we get a good match there, use it. */ 2836 2837 if (qualified_name[next_namespace_len] == ':') 2838 { 2839 searched_deeper = 1; 2840 2841 if (find_oload_champ_namespace_loop (args, 2842 func_name, qualified_name, 2843 next_namespace_len, 2844 oload_syms, oload_champ_bv, 2845 oload_champ, no_adl)) 2846 { 2847 return 1; 2848 } 2849 }; 2850 2851 /* If we reach here, either we're in the deepest namespace or we 2852 didn't find a good match in a deeper namespace. But, in the 2853 latter case, we still have a bad match in a deeper namespace; 2854 note that we might not find any match at all in the current 2855 namespace. (There's always a match in the deepest namespace, 2856 because this overload mechanism only gets called if there's a 2857 function symbol to start off with.) */ 2858 2859 new_namespace = (char *) alloca (namespace_len + 1); 2860 strncpy (new_namespace, qualified_name, namespace_len); 2861 new_namespace[namespace_len] = '\0'; 2862 2863 std::vector<symbol *> new_oload_syms 2864 = make_symbol_overload_list (func_name, new_namespace); 2865 2866 /* If we have reached the deepest level perform argument 2867 determined lookup. */ 2868 if (!searched_deeper && !no_adl) 2869 { 2870 int ix; 2871 struct type **arg_types; 2872 2873 /* Prepare list of argument types for overload resolution. */ 2874 arg_types = (struct type **) 2875 alloca (args.size () * (sizeof (struct type *))); 2876 for (ix = 0; ix < args.size (); ix++) 2877 arg_types[ix] = value_type (args[ix]); 2878 add_symbol_overload_list_adl ({arg_types, args.size ()}, func_name, 2879 &new_oload_syms); 2880 } 2881 2882 badness_vector new_oload_champ_bv; 2883 new_oload_champ = find_oload_champ (args, 2884 new_oload_syms.size (), 2885 NULL, NULL, new_oload_syms.data (), 2886 &new_oload_champ_bv); 2887 2888 /* Case 1: We found a good match. Free earlier matches (if any), 2889 and return it. Case 2: We didn't find a good match, but we're 2890 not the deepest function. Then go with the bad match that the 2891 deeper function found. Case 3: We found a bad match, and we're 2892 the deepest function. Then return what we found, even though 2893 it's a bad match. */ 2894 2895 if (new_oload_champ != -1 2896 && classify_oload_match (new_oload_champ_bv, args.size (), 0) == STANDARD) 2897 { 2898 *oload_syms = std::move (new_oload_syms); 2899 *oload_champ = new_oload_champ; 2900 *oload_champ_bv = std::move (new_oload_champ_bv); 2901 return 1; 2902 } 2903 else if (searched_deeper) 2904 { 2905 return 0; 2906 } 2907 else 2908 { 2909 *oload_syms = std::move (new_oload_syms); 2910 *oload_champ = new_oload_champ; 2911 *oload_champ_bv = std::move (new_oload_champ_bv); 2912 return 0; 2913 } 2914 } 2915 2916 /* Look for a function to take ARGS. Find the best match from among 2917 the overloaded methods or functions given by METHODS or FUNCTIONS 2918 or XMETHODS, respectively. One, and only one of METHODS, FUNCTIONS 2919 and XMETHODS can be non-NULL. 2920 2921 NUM_FNS is the length of the array pointed at by METHODS, FUNCTIONS 2922 or XMETHODS, whichever is non-NULL. 2923 2924 Return the index of the best match; store an indication of the 2925 quality of the match in OLOAD_CHAMP_BV. */ 2926 2927 static int 2928 find_oload_champ (gdb::array_view<value *> args, 2929 size_t num_fns, 2930 fn_field *methods, 2931 xmethod_worker_up *xmethods, 2932 symbol **functions, 2933 badness_vector *oload_champ_bv) 2934 { 2935 /* A measure of how good an overloaded instance is. */ 2936 badness_vector bv; 2937 /* Index of best overloaded function. */ 2938 int oload_champ = -1; 2939 /* Current ambiguity state for overload resolution. */ 2940 int oload_ambiguous = 0; 2941 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */ 2942 2943 /* A champion can be found among methods alone, or among functions 2944 alone, or in xmethods alone, but not in more than one of these 2945 groups. */ 2946 gdb_assert ((methods != NULL) + (functions != NULL) + (xmethods != NULL) 2947 == 1); 2948 2949 /* Consider each candidate in turn. */ 2950 for (size_t ix = 0; ix < num_fns; ix++) 2951 { 2952 int jj; 2953 int static_offset = 0; 2954 std::vector<type *> parm_types; 2955 2956 if (xmethods != NULL) 2957 parm_types = xmethods[ix]->get_arg_types (); 2958 else 2959 { 2960 size_t nparms; 2961 2962 if (methods != NULL) 2963 { 2964 nparms = TYPE_FN_FIELD_TYPE (methods, ix)->num_fields (); 2965 static_offset = oload_method_static_p (methods, ix); 2966 } 2967 else 2968 nparms = SYMBOL_TYPE (functions[ix])->num_fields (); 2969 2970 parm_types.reserve (nparms); 2971 for (jj = 0; jj < nparms; jj++) 2972 { 2973 type *t = (methods != NULL 2974 ? (TYPE_FN_FIELD_ARGS (methods, ix)[jj].type ()) 2975 : SYMBOL_TYPE (functions[ix])->field (jj).type ()); 2976 parm_types.push_back (t); 2977 } 2978 } 2979 2980 /* Compare parameter types to supplied argument types. Skip 2981 THIS for static methods. */ 2982 bv = rank_function (parm_types, 2983 args.slice (static_offset)); 2984 2985 if (overload_debug) 2986 { 2987 if (methods != NULL) 2988 fprintf_filtered (gdb_stderr, 2989 "Overloaded method instance %s, # of parms %d\n", 2990 methods[ix].physname, (int) parm_types.size ()); 2991 else if (xmethods != NULL) 2992 fprintf_filtered (gdb_stderr, 2993 "Xmethod worker, # of parms %d\n", 2994 (int) parm_types.size ()); 2995 else 2996 fprintf_filtered (gdb_stderr, 2997 "Overloaded function instance " 2998 "%s # of parms %d\n", 2999 functions[ix]->demangled_name (), 3000 (int) parm_types.size ()); 3001 3002 fprintf_filtered (gdb_stderr, 3003 "...Badness of length : {%d, %d}\n", 3004 bv[0].rank, bv[0].subrank); 3005 3006 for (jj = 1; jj < bv.size (); jj++) 3007 fprintf_filtered (gdb_stderr, 3008 "...Badness of arg %d : {%d, %d}\n", 3009 jj, bv[jj].rank, bv[jj].subrank); 3010 } 3011 3012 if (oload_champ_bv->empty ()) 3013 { 3014 *oload_champ_bv = std::move (bv); 3015 oload_champ = 0; 3016 } 3017 else /* See whether current candidate is better or worse than 3018 previous best. */ 3019 switch (compare_badness (bv, *oload_champ_bv)) 3020 { 3021 case 0: /* Top two contenders are equally good. */ 3022 oload_ambiguous = 1; 3023 break; 3024 case 1: /* Incomparable top contenders. */ 3025 oload_ambiguous = 2; 3026 break; 3027 case 2: /* New champion, record details. */ 3028 *oload_champ_bv = std::move (bv); 3029 oload_ambiguous = 0; 3030 oload_champ = ix; 3031 break; 3032 case 3: 3033 default: 3034 break; 3035 } 3036 if (overload_debug) 3037 fprintf_filtered (gdb_stderr, "Overload resolution " 3038 "champion is %d, ambiguous? %d\n", 3039 oload_champ, oload_ambiguous); 3040 } 3041 3042 return oload_champ; 3043 } 3044 3045 /* Return 1 if we're looking at a static method, 0 if we're looking at 3046 a non-static method or a function that isn't a method. */ 3047 3048 static int 3049 oload_method_static_p (struct fn_field *fns_ptr, int index) 3050 { 3051 if (fns_ptr && index >= 0 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index)) 3052 return 1; 3053 else 3054 return 0; 3055 } 3056 3057 /* Check how good an overload match OLOAD_CHAMP_BV represents. */ 3058 3059 static enum oload_classification 3060 classify_oload_match (const badness_vector &oload_champ_bv, 3061 int nargs, 3062 int static_offset) 3063 { 3064 int ix; 3065 enum oload_classification worst = STANDARD; 3066 3067 for (ix = 1; ix <= nargs - static_offset; ix++) 3068 { 3069 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS 3070 or worse return INCOMPATIBLE. */ 3071 if (compare_ranks (oload_champ_bv[ix], 3072 INCOMPATIBLE_TYPE_BADNESS) <= 0) 3073 return INCOMPATIBLE; /* Truly mismatched types. */ 3074 /* Otherwise If this conversion is as bad as 3075 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */ 3076 else if (compare_ranks (oload_champ_bv[ix], 3077 NS_POINTER_CONVERSION_BADNESS) <= 0) 3078 worst = NON_STANDARD; /* Non-standard type conversions 3079 needed. */ 3080 } 3081 3082 /* If no INCOMPATIBLE classification was found, return the worst one 3083 that was found (if any). */ 3084 return worst; 3085 } 3086 3087 /* C++: return 1 is NAME is a legitimate name for the destructor of 3088 type TYPE. If TYPE does not have a destructor, or if NAME is 3089 inappropriate for TYPE, an error is signaled. Parameter TYPE should not yet 3090 have CHECK_TYPEDEF applied, this function will apply it itself. */ 3091 3092 int 3093 destructor_name_p (const char *name, struct type *type) 3094 { 3095 if (name[0] == '~') 3096 { 3097 const char *dname = type_name_or_error (type); 3098 const char *cp = strchr (dname, '<'); 3099 unsigned int len; 3100 3101 /* Do not compare the template part for template classes. */ 3102 if (cp == NULL) 3103 len = strlen (dname); 3104 else 3105 len = cp - dname; 3106 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0) 3107 error (_("name of destructor must equal name of class")); 3108 else 3109 return 1; 3110 } 3111 return 0; 3112 } 3113 3114 /* Find an enum constant named NAME in TYPE. TYPE must be an "enum 3115 class". If the name is found, return a value representing it; 3116 otherwise throw an exception. */ 3117 3118 static struct value * 3119 enum_constant_from_type (struct type *type, const char *name) 3120 { 3121 int i; 3122 int name_len = strlen (name); 3123 3124 gdb_assert (type->code () == TYPE_CODE_ENUM 3125 && TYPE_DECLARED_CLASS (type)); 3126 3127 for (i = TYPE_N_BASECLASSES (type); i < type->num_fields (); ++i) 3128 { 3129 const char *fname = TYPE_FIELD_NAME (type, i); 3130 int len; 3131 3132 if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL 3133 || fname == NULL) 3134 continue; 3135 3136 /* Look for the trailing "::NAME", since enum class constant 3137 names are qualified here. */ 3138 len = strlen (fname); 3139 if (len + 2 >= name_len 3140 && fname[len - name_len - 2] == ':' 3141 && fname[len - name_len - 1] == ':' 3142 && strcmp (&fname[len - name_len], name) == 0) 3143 return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i)); 3144 } 3145 3146 error (_("no constant named \"%s\" in enum \"%s\""), 3147 name, type->name ()); 3148 } 3149 3150 /* C++: Given an aggregate type CURTYPE, and a member name NAME, 3151 return the appropriate member (or the address of the member, if 3152 WANT_ADDRESS). This function is used to resolve user expressions 3153 of the form "DOMAIN::NAME". For more details on what happens, see 3154 the comment before value_struct_elt_for_reference. */ 3155 3156 struct value * 3157 value_aggregate_elt (struct type *curtype, const char *name, 3158 struct type *expect_type, int want_address, 3159 enum noside noside) 3160 { 3161 switch (curtype->code ()) 3162 { 3163 case TYPE_CODE_STRUCT: 3164 case TYPE_CODE_UNION: 3165 return value_struct_elt_for_reference (curtype, 0, curtype, 3166 name, expect_type, 3167 want_address, noside); 3168 case TYPE_CODE_NAMESPACE: 3169 return value_namespace_elt (curtype, name, 3170 want_address, noside); 3171 3172 case TYPE_CODE_ENUM: 3173 return enum_constant_from_type (curtype, name); 3174 3175 default: 3176 internal_error (__FILE__, __LINE__, 3177 _("non-aggregate type in value_aggregate_elt")); 3178 } 3179 } 3180 3181 /* Compares the two method/function types T1 and T2 for "equality" 3182 with respect to the methods' parameters. If the types of the 3183 two parameter lists are the same, returns 1; 0 otherwise. This 3184 comparison may ignore any artificial parameters in T1 if 3185 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip 3186 the first artificial parameter in T1, assumed to be a 'this' pointer. 3187 3188 The type T2 is expected to have come from make_params (in eval.c). */ 3189 3190 static int 3191 compare_parameters (struct type *t1, struct type *t2, int skip_artificial) 3192 { 3193 int start = 0; 3194 3195 if (t1->num_fields () > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0)) 3196 ++start; 3197 3198 /* If skipping artificial fields, find the first real field 3199 in T1. */ 3200 if (skip_artificial) 3201 { 3202 while (start < t1->num_fields () 3203 && TYPE_FIELD_ARTIFICIAL (t1, start)) 3204 ++start; 3205 } 3206 3207 /* Now compare parameters. */ 3208 3209 /* Special case: a method taking void. T1 will contain no 3210 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */ 3211 if ((t1->num_fields () - start) == 0 && t2->num_fields () == 1 3212 && t2->field (0).type ()->code () == TYPE_CODE_VOID) 3213 return 1; 3214 3215 if ((t1->num_fields () - start) == t2->num_fields ()) 3216 { 3217 int i; 3218 3219 for (i = 0; i < t2->num_fields (); ++i) 3220 { 3221 if (compare_ranks (rank_one_type (t1->field (start + i).type (), 3222 t2->field (i).type (), NULL), 3223 EXACT_MATCH_BADNESS) != 0) 3224 return 0; 3225 } 3226 3227 return 1; 3228 } 3229 3230 return 0; 3231 } 3232 3233 /* C++: Given an aggregate type VT, and a class type CLS, search 3234 recursively for CLS using value V; If found, store the offset 3235 which is either fetched from the virtual base pointer if CLS 3236 is virtual or accumulated offset of its parent classes if 3237 CLS is non-virtual in *BOFFS, set ISVIRT to indicate if CLS 3238 is virtual, and return true. If not found, return false. */ 3239 3240 static bool 3241 get_baseclass_offset (struct type *vt, struct type *cls, 3242 struct value *v, int *boffs, bool *isvirt) 3243 { 3244 for (int i = 0; i < TYPE_N_BASECLASSES (vt); i++) 3245 { 3246 struct type *t = vt->field (i).type (); 3247 if (types_equal (t, cls)) 3248 { 3249 if (BASETYPE_VIA_VIRTUAL (vt, i)) 3250 { 3251 const gdb_byte *adr = value_contents_for_printing (v); 3252 *boffs = baseclass_offset (vt, i, adr, value_offset (v), 3253 value_as_long (v), v); 3254 *isvirt = true; 3255 } 3256 else 3257 *isvirt = false; 3258 return true; 3259 } 3260 3261 if (get_baseclass_offset (check_typedef (t), cls, v, boffs, isvirt)) 3262 { 3263 if (*isvirt == false) /* Add non-virtual base offset. */ 3264 { 3265 const gdb_byte *adr = value_contents_for_printing (v); 3266 *boffs += baseclass_offset (vt, i, adr, value_offset (v), 3267 value_as_long (v), v); 3268 } 3269 return true; 3270 } 3271 } 3272 3273 return false; 3274 } 3275 3276 /* C++: Given an aggregate type CURTYPE, and a member name NAME, 3277 return the address of this member as a "pointer to member" type. 3278 If INTYPE is non-null, then it will be the type of the member we 3279 are looking for. This will help us resolve "pointers to member 3280 functions". This function is used to resolve user expressions of 3281 the form "DOMAIN::NAME". */ 3282 3283 static struct value * 3284 value_struct_elt_for_reference (struct type *domain, int offset, 3285 struct type *curtype, const char *name, 3286 struct type *intype, 3287 int want_address, 3288 enum noside noside) 3289 { 3290 struct type *t = check_typedef (curtype); 3291 int i; 3292 struct value *result; 3293 3294 if (t->code () != TYPE_CODE_STRUCT 3295 && t->code () != TYPE_CODE_UNION) 3296 error (_("Internal error: non-aggregate type " 3297 "to value_struct_elt_for_reference")); 3298 3299 for (i = t->num_fields () - 1; i >= TYPE_N_BASECLASSES (t); i--) 3300 { 3301 const char *t_field_name = TYPE_FIELD_NAME (t, i); 3302 3303 if (t_field_name && strcmp (t_field_name, name) == 0) 3304 { 3305 if (field_is_static (&t->field (i))) 3306 { 3307 struct value *v = value_static_field (t, i); 3308 if (want_address) 3309 v = value_addr (v); 3310 return v; 3311 } 3312 if (TYPE_FIELD_PACKED (t, i)) 3313 error (_("pointers to bitfield members not allowed")); 3314 3315 if (want_address) 3316 return value_from_longest 3317 (lookup_memberptr_type (t->field (i).type (), domain), 3318 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3)); 3319 else if (noside != EVAL_NORMAL) 3320 return allocate_value (t->field (i).type ()); 3321 else 3322 { 3323 /* Try to evaluate NAME as a qualified name with implicit 3324 this pointer. In this case, attempt to return the 3325 equivalent to `this->*(&TYPE::NAME)'. */ 3326 struct value *v = value_of_this_silent (current_language); 3327 if (v != NULL) 3328 { 3329 struct value *ptr, *this_v = v; 3330 long mem_offset; 3331 struct type *type, *tmp; 3332 3333 ptr = value_aggregate_elt (domain, name, NULL, 1, noside); 3334 type = check_typedef (value_type (ptr)); 3335 gdb_assert (type != NULL 3336 && type->code () == TYPE_CODE_MEMBERPTR); 3337 tmp = lookup_pointer_type (TYPE_SELF_TYPE (type)); 3338 v = value_cast_pointers (tmp, v, 1); 3339 mem_offset = value_as_long (ptr); 3340 if (domain != curtype) 3341 { 3342 /* Find class offset of type CURTYPE from either its 3343 parent type DOMAIN or the type of implied this. */ 3344 int boff = 0; 3345 bool isvirt = false; 3346 if (get_baseclass_offset (domain, curtype, v, &boff, 3347 &isvirt)) 3348 mem_offset += boff; 3349 else 3350 { 3351 struct type *p = check_typedef (value_type (this_v)); 3352 p = check_typedef (TYPE_TARGET_TYPE (p)); 3353 if (get_baseclass_offset (p, curtype, this_v, 3354 &boff, &isvirt)) 3355 mem_offset += boff; 3356 } 3357 } 3358 tmp = lookup_pointer_type (TYPE_TARGET_TYPE (type)); 3359 result = value_from_pointer (tmp, 3360 value_as_long (v) + mem_offset); 3361 return value_ind (result); 3362 } 3363 3364 error (_("Cannot reference non-static field \"%s\""), name); 3365 } 3366 } 3367 } 3368 3369 /* C++: If it was not found as a data field, then try to return it 3370 as a pointer to a method. */ 3371 3372 /* Perform all necessary dereferencing. */ 3373 while (intype && intype->code () == TYPE_CODE_PTR) 3374 intype = TYPE_TARGET_TYPE (intype); 3375 3376 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i) 3377 { 3378 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i); 3379 3380 if (t_field_name && strcmp (t_field_name, name) == 0) 3381 { 3382 int j; 3383 int len = TYPE_FN_FIELDLIST_LENGTH (t, i); 3384 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i); 3385 3386 check_stub_method_group (t, i); 3387 3388 if (intype) 3389 { 3390 for (j = 0; j < len; ++j) 3391 { 3392 if (TYPE_CONST (intype) != TYPE_FN_FIELD_CONST (f, j)) 3393 continue; 3394 if (TYPE_VOLATILE (intype) != TYPE_FN_FIELD_VOLATILE (f, j)) 3395 continue; 3396 3397 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0) 3398 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j), 3399 intype, 1)) 3400 break; 3401 } 3402 3403 if (j == len) 3404 error (_("no member function matches " 3405 "that type instantiation")); 3406 } 3407 else 3408 { 3409 int ii; 3410 3411 j = -1; 3412 for (ii = 0; ii < len; ++ii) 3413 { 3414 /* Skip artificial methods. This is necessary if, 3415 for example, the user wants to "print 3416 subclass::subclass" with only one user-defined 3417 constructor. There is no ambiguity in this case. 3418 We are careful here to allow artificial methods 3419 if they are the unique result. */ 3420 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii)) 3421 { 3422 if (j == -1) 3423 j = ii; 3424 continue; 3425 } 3426 3427 /* Desired method is ambiguous if more than one 3428 method is defined. */ 3429 if (j != -1 && !TYPE_FN_FIELD_ARTIFICIAL (f, j)) 3430 error (_("non-unique member `%s' requires " 3431 "type instantiation"), name); 3432 3433 j = ii; 3434 } 3435 3436 if (j == -1) 3437 error (_("no matching member function")); 3438 } 3439 3440 if (TYPE_FN_FIELD_STATIC_P (f, j)) 3441 { 3442 struct symbol *s = 3443 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j), 3444 0, VAR_DOMAIN, 0).symbol; 3445 3446 if (s == NULL) 3447 return NULL; 3448 3449 if (want_address) 3450 return value_addr (read_var_value (s, 0, 0)); 3451 else 3452 return read_var_value (s, 0, 0); 3453 } 3454 3455 if (TYPE_FN_FIELD_VIRTUAL_P (f, j)) 3456 { 3457 if (want_address) 3458 { 3459 result = allocate_value 3460 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j))); 3461 cplus_make_method_ptr (value_type (result), 3462 value_contents_writeable (result), 3463 TYPE_FN_FIELD_VOFFSET (f, j), 1); 3464 } 3465 else if (noside == EVAL_AVOID_SIDE_EFFECTS) 3466 return allocate_value (TYPE_FN_FIELD_TYPE (f, j)); 3467 else 3468 error (_("Cannot reference virtual member function \"%s\""), 3469 name); 3470 } 3471 else 3472 { 3473 struct symbol *s = 3474 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j), 3475 0, VAR_DOMAIN, 0).symbol; 3476 3477 if (s == NULL) 3478 return NULL; 3479 3480 struct value *v = read_var_value (s, 0, 0); 3481 if (!want_address) 3482 result = v; 3483 else 3484 { 3485 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j))); 3486 cplus_make_method_ptr (value_type (result), 3487 value_contents_writeable (result), 3488 value_address (v), 0); 3489 } 3490 } 3491 return result; 3492 } 3493 } 3494 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--) 3495 { 3496 struct value *v; 3497 int base_offset; 3498 3499 if (BASETYPE_VIA_VIRTUAL (t, i)) 3500 base_offset = 0; 3501 else 3502 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8; 3503 v = value_struct_elt_for_reference (domain, 3504 offset + base_offset, 3505 TYPE_BASECLASS (t, i), 3506 name, intype, 3507 want_address, noside); 3508 if (v) 3509 return v; 3510 } 3511 3512 /* As a last chance, pretend that CURTYPE is a namespace, and look 3513 it up that way; this (frequently) works for types nested inside 3514 classes. */ 3515 3516 return value_maybe_namespace_elt (curtype, name, 3517 want_address, noside); 3518 } 3519 3520 /* C++: Return the member NAME of the namespace given by the type 3521 CURTYPE. */ 3522 3523 static struct value * 3524 value_namespace_elt (const struct type *curtype, 3525 const char *name, int want_address, 3526 enum noside noside) 3527 { 3528 struct value *retval = value_maybe_namespace_elt (curtype, name, 3529 want_address, 3530 noside); 3531 3532 if (retval == NULL) 3533 error (_("No symbol \"%s\" in namespace \"%s\"."), 3534 name, curtype->name ()); 3535 3536 return retval; 3537 } 3538 3539 /* A helper function used by value_namespace_elt and 3540 value_struct_elt_for_reference. It looks up NAME inside the 3541 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE 3542 is a class and NAME refers to a type in CURTYPE itself (as opposed 3543 to, say, some base class of CURTYPE). */ 3544 3545 static struct value * 3546 value_maybe_namespace_elt (const struct type *curtype, 3547 const char *name, int want_address, 3548 enum noside noside) 3549 { 3550 const char *namespace_name = curtype->name (); 3551 struct block_symbol sym; 3552 struct value *result; 3553 3554 sym = cp_lookup_symbol_namespace (namespace_name, name, 3555 get_selected_block (0), VAR_DOMAIN); 3556 3557 if (sym.symbol == NULL) 3558 return NULL; 3559 else if ((noside == EVAL_AVOID_SIDE_EFFECTS) 3560 && (SYMBOL_CLASS (sym.symbol) == LOC_TYPEDEF)) 3561 result = allocate_value (SYMBOL_TYPE (sym.symbol)); 3562 else 3563 result = value_of_variable (sym.symbol, sym.block); 3564 3565 if (want_address) 3566 result = value_addr (result); 3567 3568 return result; 3569 } 3570 3571 /* Given a pointer or a reference value V, find its real (RTTI) type. 3572 3573 Other parameters FULL, TOP, USING_ENC as with value_rtti_type() 3574 and refer to the values computed for the object pointed to. */ 3575 3576 struct type * 3577 value_rtti_indirect_type (struct value *v, int *full, 3578 LONGEST *top, int *using_enc) 3579 { 3580 struct value *target = NULL; 3581 struct type *type, *real_type, *target_type; 3582 3583 type = value_type (v); 3584 type = check_typedef (type); 3585 if (TYPE_IS_REFERENCE (type)) 3586 target = coerce_ref (v); 3587 else if (type->code () == TYPE_CODE_PTR) 3588 { 3589 3590 try 3591 { 3592 target = value_ind (v); 3593 } 3594 catch (const gdb_exception_error &except) 3595 { 3596 if (except.error == MEMORY_ERROR) 3597 { 3598 /* value_ind threw a memory error. The pointer is NULL or 3599 contains an uninitialized value: we can't determine any 3600 type. */ 3601 return NULL; 3602 } 3603 throw; 3604 } 3605 } 3606 else 3607 return NULL; 3608 3609 real_type = value_rtti_type (target, full, top, using_enc); 3610 3611 if (real_type) 3612 { 3613 /* Copy qualifiers to the referenced object. */ 3614 target_type = value_type (target); 3615 real_type = make_cv_type (TYPE_CONST (target_type), 3616 TYPE_VOLATILE (target_type), real_type, NULL); 3617 if (TYPE_IS_REFERENCE (type)) 3618 real_type = lookup_reference_type (real_type, type->code ()); 3619 else if (type->code () == TYPE_CODE_PTR) 3620 real_type = lookup_pointer_type (real_type); 3621 else 3622 internal_error (__FILE__, __LINE__, _("Unexpected value type.")); 3623 3624 /* Copy qualifiers to the pointer/reference. */ 3625 real_type = make_cv_type (TYPE_CONST (type), TYPE_VOLATILE (type), 3626 real_type, NULL); 3627 } 3628 3629 return real_type; 3630 } 3631 3632 /* Given a value pointed to by ARGP, check its real run-time type, and 3633 if that is different from the enclosing type, create a new value 3634 using the real run-time type as the enclosing type (and of the same 3635 type as ARGP) and return it, with the embedded offset adjusted to 3636 be the correct offset to the enclosed object. RTYPE is the type, 3637 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed 3638 by value_rtti_type(). If these are available, they can be supplied 3639 and a second call to value_rtti_type() is avoided. (Pass RTYPE == 3640 NULL if they're not available. */ 3641 3642 struct value * 3643 value_full_object (struct value *argp, 3644 struct type *rtype, 3645 int xfull, int xtop, 3646 int xusing_enc) 3647 { 3648 struct type *real_type; 3649 int full = 0; 3650 LONGEST top = -1; 3651 int using_enc = 0; 3652 struct value *new_val; 3653 3654 if (rtype) 3655 { 3656 real_type = rtype; 3657 full = xfull; 3658 top = xtop; 3659 using_enc = xusing_enc; 3660 } 3661 else 3662 real_type = value_rtti_type (argp, &full, &top, &using_enc); 3663 3664 /* If no RTTI data, or if object is already complete, do nothing. */ 3665 if (!real_type || real_type == value_enclosing_type (argp)) 3666 return argp; 3667 3668 /* In a destructor we might see a real type that is a superclass of 3669 the object's type. In this case it is better to leave the object 3670 as-is. */ 3671 if (full 3672 && TYPE_LENGTH (real_type) < TYPE_LENGTH (value_enclosing_type (argp))) 3673 return argp; 3674 3675 /* If we have the full object, but for some reason the enclosing 3676 type is wrong, set it. */ 3677 /* pai: FIXME -- sounds iffy */ 3678 if (full) 3679 { 3680 argp = value_copy (argp); 3681 set_value_enclosing_type (argp, real_type); 3682 return argp; 3683 } 3684 3685 /* Check if object is in memory. */ 3686 if (VALUE_LVAL (argp) != lval_memory) 3687 { 3688 warning (_("Couldn't retrieve complete object of RTTI " 3689 "type %s; object may be in register(s)."), 3690 real_type->name ()); 3691 3692 return argp; 3693 } 3694 3695 /* All other cases -- retrieve the complete object. */ 3696 /* Go back by the computed top_offset from the beginning of the 3697 object, adjusting for the embedded offset of argp if that's what 3698 value_rtti_type used for its computation. */ 3699 new_val = value_at_lazy (real_type, value_address (argp) - top + 3700 (using_enc ? 0 : value_embedded_offset (argp))); 3701 deprecated_set_value_type (new_val, value_type (argp)); 3702 set_value_embedded_offset (new_val, (using_enc 3703 ? top + value_embedded_offset (argp) 3704 : top)); 3705 return new_val; 3706 } 3707 3708 3709 /* Return the value of the local variable, if one exists. Throw error 3710 otherwise, such as if the request is made in an inappropriate context. */ 3711 3712 struct value * 3713 value_of_this (const struct language_defn *lang) 3714 { 3715 struct block_symbol sym; 3716 const struct block *b; 3717 struct frame_info *frame; 3718 3719 if (!lang->la_name_of_this) 3720 error (_("no `this' in current language")); 3721 3722 frame = get_selected_frame (_("no frame selected")); 3723 3724 b = get_frame_block (frame, NULL); 3725 3726 sym = lookup_language_this (lang, b); 3727 if (sym.symbol == NULL) 3728 error (_("current stack frame does not contain a variable named `%s'"), 3729 lang->la_name_of_this); 3730 3731 return read_var_value (sym.symbol, sym.block, frame); 3732 } 3733 3734 /* Return the value of the local variable, if one exists. Return NULL 3735 otherwise. Never throw error. */ 3736 3737 struct value * 3738 value_of_this_silent (const struct language_defn *lang) 3739 { 3740 struct value *ret = NULL; 3741 3742 try 3743 { 3744 ret = value_of_this (lang); 3745 } 3746 catch (const gdb_exception_error &except) 3747 { 3748 } 3749 3750 return ret; 3751 } 3752 3753 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH 3754 elements long, starting at LOWBOUND. The result has the same lower 3755 bound as the original ARRAY. */ 3756 3757 struct value * 3758 value_slice (struct value *array, int lowbound, int length) 3759 { 3760 struct type *slice_range_type, *slice_type, *range_type; 3761 LONGEST lowerbound, upperbound; 3762 struct value *slice; 3763 struct type *array_type; 3764 3765 array_type = check_typedef (value_type (array)); 3766 if (array_type->code () != TYPE_CODE_ARRAY 3767 && array_type->code () != TYPE_CODE_STRING) 3768 error (_("cannot take slice of non-array")); 3769 3770 if (type_not_allocated (array_type)) 3771 error (_("array not allocated")); 3772 if (type_not_associated (array_type)) 3773 error (_("array not associated")); 3774 3775 range_type = array_type->index_type (); 3776 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0) 3777 error (_("slice from bad array or bitstring")); 3778 3779 if (lowbound < lowerbound || length < 0 3780 || lowbound + length - 1 > upperbound) 3781 error (_("slice out of range")); 3782 3783 /* FIXME-type-allocation: need a way to free this type when we are 3784 done with it. */ 3785 slice_range_type = create_static_range_type (NULL, 3786 TYPE_TARGET_TYPE (range_type), 3787 lowbound, 3788 lowbound + length - 1); 3789 3790 { 3791 struct type *element_type = TYPE_TARGET_TYPE (array_type); 3792 LONGEST offset 3793 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type)); 3794 3795 slice_type = create_array_type (NULL, 3796 element_type, 3797 slice_range_type); 3798 slice_type->set_code (array_type->code ()); 3799 3800 if (VALUE_LVAL (array) == lval_memory && value_lazy (array)) 3801 slice = allocate_value_lazy (slice_type); 3802 else 3803 { 3804 slice = allocate_value (slice_type); 3805 value_contents_copy (slice, 0, array, offset, 3806 type_length_units (slice_type)); 3807 } 3808 3809 set_value_component_location (slice, array); 3810 set_value_offset (slice, value_offset (array) + offset); 3811 } 3812 3813 return slice; 3814 } 3815 3816 /* See value.h. */ 3817 3818 struct value * 3819 value_literal_complex (struct value *arg1, 3820 struct value *arg2, 3821 struct type *type) 3822 { 3823 struct value *val; 3824 struct type *real_type = TYPE_TARGET_TYPE (type); 3825 3826 val = allocate_value (type); 3827 arg1 = value_cast (real_type, arg1); 3828 arg2 = value_cast (real_type, arg2); 3829 3830 memcpy (value_contents_raw (val), 3831 value_contents (arg1), TYPE_LENGTH (real_type)); 3832 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type), 3833 value_contents (arg2), TYPE_LENGTH (real_type)); 3834 return val; 3835 } 3836 3837 /* See value.h. */ 3838 3839 struct value * 3840 value_real_part (struct value *value) 3841 { 3842 struct type *type = check_typedef (value_type (value)); 3843 struct type *ttype = TYPE_TARGET_TYPE (type); 3844 3845 gdb_assert (type->code () == TYPE_CODE_COMPLEX); 3846 return value_from_component (value, ttype, 0); 3847 } 3848 3849 /* See value.h. */ 3850 3851 struct value * 3852 value_imaginary_part (struct value *value) 3853 { 3854 struct type *type = check_typedef (value_type (value)); 3855 struct type *ttype = TYPE_TARGET_TYPE (type); 3856 3857 gdb_assert (type->code () == TYPE_CODE_COMPLEX); 3858 return value_from_component (value, ttype, 3859 TYPE_LENGTH (check_typedef (ttype))); 3860 } 3861 3862 /* Cast a value into the appropriate complex data type. */ 3863 3864 static struct value * 3865 cast_into_complex (struct type *type, struct value *val) 3866 { 3867 struct type *real_type = TYPE_TARGET_TYPE (type); 3868 3869 if (value_type (val)->code () == TYPE_CODE_COMPLEX) 3870 { 3871 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val)); 3872 struct value *re_val = allocate_value (val_real_type); 3873 struct value *im_val = allocate_value (val_real_type); 3874 3875 memcpy (value_contents_raw (re_val), 3876 value_contents (val), TYPE_LENGTH (val_real_type)); 3877 memcpy (value_contents_raw (im_val), 3878 value_contents (val) + TYPE_LENGTH (val_real_type), 3879 TYPE_LENGTH (val_real_type)); 3880 3881 return value_literal_complex (re_val, im_val, type); 3882 } 3883 else if (value_type (val)->code () == TYPE_CODE_FLT 3884 || value_type (val)->code () == TYPE_CODE_INT) 3885 return value_literal_complex (val, 3886 value_zero (real_type, not_lval), 3887 type); 3888 else 3889 error (_("cannot cast non-number to complex")); 3890 } 3891 3892 void _initialize_valops (); 3893 void 3894 _initialize_valops () 3895 { 3896 add_setshow_boolean_cmd ("overload-resolution", class_support, 3897 &overload_resolution, _("\ 3898 Set overload resolution in evaluating C++ functions."), _("\ 3899 Show overload resolution in evaluating C++ functions."), 3900 NULL, NULL, 3901 show_overload_resolution, 3902 &setlist, &showlist); 3903 overload_resolution = 1; 3904 } 3905