1 /* Support for printing C++ values for GDB, the GNU debugger. 2 3 Copyright (C) 1986-2013 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 "gdb_obstack.h" 22 #include "symtab.h" 23 #include "gdbtypes.h" 24 #include "expression.h" 25 #include "value.h" 26 #include "command.h" 27 #include "gdbcmd.h" 28 #include "demangle.h" 29 #include "annotate.h" 30 #include "gdb_string.h" 31 #include "c-lang.h" 32 #include "target.h" 33 #include "cp-abi.h" 34 #include "valprint.h" 35 #include "cp-support.h" 36 #include "language.h" 37 #include "python/python.h" 38 #include "exceptions.h" 39 #include "typeprint.h" 40 41 /* Controls printing of vtbl's. */ 42 static void 43 show_vtblprint (struct ui_file *file, int from_tty, 44 struct cmd_list_element *c, const char *value) 45 { 46 fprintf_filtered (file, _("\ 47 Printing of C++ virtual function tables is %s.\n"), 48 value); 49 } 50 51 /* Controls looking up an object's derived type using what we find in 52 its vtables. */ 53 static void 54 show_objectprint (struct ui_file *file, int from_tty, 55 struct cmd_list_element *c, 56 const char *value) 57 { 58 fprintf_filtered (file, _("\ 59 Printing of object's derived type based on vtable info is %s.\n"), 60 value); 61 } 62 63 static void 64 show_static_field_print (struct ui_file *file, int from_tty, 65 struct cmd_list_element *c, 66 const char *value) 67 { 68 fprintf_filtered (file, 69 _("Printing of C++ static members is %s.\n"), 70 value); 71 } 72 73 74 static struct obstack dont_print_vb_obstack; 75 static struct obstack dont_print_statmem_obstack; 76 static struct obstack dont_print_stat_array_obstack; 77 78 extern void _initialize_cp_valprint (void); 79 80 static void cp_print_static_field (struct type *, struct value *, 81 struct ui_file *, int, 82 const struct value_print_options *); 83 84 static void cp_print_value (struct type *, struct type *, 85 const gdb_byte *, int, 86 CORE_ADDR, struct ui_file *, 87 int, const struct value *, 88 const struct value_print_options *, 89 struct type **); 90 91 92 /* GCC versions after 2.4.5 use this. */ 93 const char vtbl_ptr_name[] = "__vtbl_ptr_type"; 94 95 /* Return truth value for assertion that TYPE is of the type 96 "pointer to virtual function". */ 97 98 int 99 cp_is_vtbl_ptr_type (struct type *type) 100 { 101 const char *typename = type_name_no_tag (type); 102 103 return (typename != NULL && !strcmp (typename, vtbl_ptr_name)); 104 } 105 106 /* Return truth value for the assertion that TYPE is of the type 107 "pointer to virtual function table". */ 108 109 int 110 cp_is_vtbl_member (struct type *type) 111 { 112 /* With older versions of g++, the vtbl field pointed to an array of 113 structures. Nowadays it points directly to the structure. */ 114 if (TYPE_CODE (type) == TYPE_CODE_PTR) 115 { 116 type = TYPE_TARGET_TYPE (type); 117 if (TYPE_CODE (type) == TYPE_CODE_ARRAY) 118 { 119 type = TYPE_TARGET_TYPE (type); 120 if (TYPE_CODE (type) == TYPE_CODE_STRUCT /* if not using thunks */ 121 || TYPE_CODE (type) == TYPE_CODE_PTR) /* if using thunks */ 122 { 123 /* Virtual functions tables are full of pointers 124 to virtual functions. */ 125 return cp_is_vtbl_ptr_type (type); 126 } 127 } 128 else if (TYPE_CODE (type) == TYPE_CODE_STRUCT) /* if not using thunks */ 129 { 130 return cp_is_vtbl_ptr_type (type); 131 } 132 else if (TYPE_CODE (type) == TYPE_CODE_PTR) /* if using thunks */ 133 { 134 /* The type name of the thunk pointer is NULL when using 135 dwarf2. We could test for a pointer to a function, but 136 there is no type info for the virtual table either, so it 137 wont help. */ 138 return cp_is_vtbl_ptr_type (type); 139 } 140 } 141 return 0; 142 } 143 144 /* Mutually recursive subroutines of cp_print_value and c_val_print to 145 print out a structure's fields: cp_print_value_fields and 146 cp_print_value. 147 148 TYPE, VALADDR, ADDRESS, STREAM, RECURSE, and OPTIONS have the same 149 meanings as in cp_print_value and c_val_print. 150 151 2nd argument REAL_TYPE is used to carry over the type of the 152 derived class across the recursion to base classes. 153 154 DONT_PRINT is an array of baseclass types that we should not print, 155 or zero if called from top level. */ 156 157 void 158 cp_print_value_fields (struct type *type, struct type *real_type, 159 const gdb_byte *valaddr, int offset, 160 CORE_ADDR address, struct ui_file *stream, 161 int recurse, const struct value *val, 162 const struct value_print_options *options, 163 struct type **dont_print_vb, 164 int dont_print_statmem) 165 { 166 int i, len, n_baseclasses; 167 int fields_seen = 0; 168 static int last_set_recurse = -1; 169 170 CHECK_TYPEDEF (type); 171 172 if (recurse == 0) 173 { 174 /* Any object can be left on obstacks only during an unexpected 175 error. */ 176 177 if (obstack_object_size (&dont_print_statmem_obstack) > 0) 178 { 179 obstack_free (&dont_print_statmem_obstack, NULL); 180 obstack_begin (&dont_print_statmem_obstack, 181 32 * sizeof (CORE_ADDR)); 182 } 183 if (obstack_object_size (&dont_print_stat_array_obstack) > 0) 184 { 185 obstack_free (&dont_print_stat_array_obstack, NULL); 186 obstack_begin (&dont_print_stat_array_obstack, 187 32 * sizeof (struct type *)); 188 } 189 } 190 191 fprintf_filtered (stream, "{"); 192 len = TYPE_NFIELDS (type); 193 n_baseclasses = TYPE_N_BASECLASSES (type); 194 195 /* First, print out baseclasses such that we don't print 196 duplicates of virtual baseclasses. */ 197 198 if (n_baseclasses > 0) 199 cp_print_value (type, real_type, valaddr, 200 offset, address, stream, 201 recurse + 1, val, options, 202 dont_print_vb); 203 204 /* Second, print out data fields */ 205 206 /* If there are no data fields, skip this part */ 207 if (len == n_baseclasses || !len) 208 fprintf_filtered (stream, "<No data fields>"); 209 else 210 { 211 int statmem_obstack_initial_size = 0; 212 int stat_array_obstack_initial_size = 0; 213 struct type *vptr_basetype = NULL; 214 int vptr_fieldno; 215 216 if (dont_print_statmem == 0) 217 { 218 statmem_obstack_initial_size = 219 obstack_object_size (&dont_print_statmem_obstack); 220 221 if (last_set_recurse != recurse) 222 { 223 stat_array_obstack_initial_size = 224 obstack_object_size (&dont_print_stat_array_obstack); 225 226 last_set_recurse = recurse; 227 } 228 } 229 230 vptr_fieldno = get_vptr_fieldno (type, &vptr_basetype); 231 for (i = n_baseclasses; i < len; i++) 232 { 233 /* If requested, skip printing of static fields. */ 234 if (!options->static_field_print 235 && field_is_static (&TYPE_FIELD (type, i))) 236 continue; 237 238 if (fields_seen) 239 fprintf_filtered (stream, ", "); 240 else if (n_baseclasses > 0) 241 { 242 if (options->pretty) 243 { 244 fprintf_filtered (stream, "\n"); 245 print_spaces_filtered (2 + 2 * recurse, stream); 246 fputs_filtered ("members of ", stream); 247 fputs_filtered (type_name_no_tag (type), stream); 248 fputs_filtered (": ", stream); 249 } 250 } 251 fields_seen = 1; 252 253 if (options->pretty) 254 { 255 fprintf_filtered (stream, "\n"); 256 print_spaces_filtered (2 + 2 * recurse, stream); 257 } 258 else 259 { 260 wrap_here (n_spaces (2 + 2 * recurse)); 261 } 262 263 annotate_field_begin (TYPE_FIELD_TYPE (type, i)); 264 265 if (field_is_static (&TYPE_FIELD (type, i))) 266 fputs_filtered ("static ", stream); 267 fprintf_symbol_filtered (stream, 268 TYPE_FIELD_NAME (type, i), 269 current_language->la_language, 270 DMGL_PARAMS | DMGL_ANSI); 271 annotate_field_name_end (); 272 /* Do not print leading '=' in case of anonymous 273 unions. */ 274 if (strcmp (TYPE_FIELD_NAME (type, i), "")) 275 fputs_filtered (" = ", stream); 276 annotate_field_value (); 277 278 if (!field_is_static (&TYPE_FIELD (type, i)) 279 && TYPE_FIELD_PACKED (type, i)) 280 { 281 struct value *v; 282 283 /* Bitfields require special handling, especially due to 284 byte order problems. */ 285 if (TYPE_FIELD_IGNORE (type, i)) 286 { 287 fputs_filtered ("<optimized out or zero length>", stream); 288 } 289 else if (value_bits_synthetic_pointer (val, 290 TYPE_FIELD_BITPOS (type, 291 i), 292 TYPE_FIELD_BITSIZE (type, 293 i))) 294 { 295 fputs_filtered (_("<synthetic pointer>"), stream); 296 } 297 else if (!value_bits_valid (val, 298 TYPE_FIELD_BITPOS (type, i), 299 TYPE_FIELD_BITSIZE (type, i))) 300 { 301 val_print_optimized_out (stream); 302 } 303 else 304 { 305 struct value_print_options opts = *options; 306 307 opts.deref_ref = 0; 308 309 v = value_field_bitfield (type, i, valaddr, offset, val); 310 311 common_val_print (v, stream, recurse + 1, &opts, 312 current_language); 313 } 314 } 315 else 316 { 317 if (TYPE_FIELD_IGNORE (type, i)) 318 { 319 fputs_filtered ("<optimized out or zero length>", 320 stream); 321 } 322 else if (field_is_static (&TYPE_FIELD (type, i))) 323 { 324 volatile struct gdb_exception ex; 325 struct value *v = NULL; 326 327 TRY_CATCH (ex, RETURN_MASK_ERROR) 328 { 329 v = value_static_field (type, i); 330 } 331 332 if (ex.reason < 0) 333 fprintf_filtered (stream, 334 _("<error reading variable: %s>"), 335 ex.message); 336 else if (v == NULL) 337 val_print_optimized_out (stream); 338 else 339 cp_print_static_field (TYPE_FIELD_TYPE (type, i), 340 v, stream, recurse + 1, 341 options); 342 } 343 else if (i == vptr_fieldno && type == vptr_basetype) 344 { 345 int i_offset = offset + TYPE_FIELD_BITPOS (type, i) / 8; 346 struct type *i_type = TYPE_FIELD_TYPE (type, i); 347 348 if (valprint_check_validity (stream, i_type, i_offset, val)) 349 { 350 CORE_ADDR addr; 351 352 addr = extract_typed_address (valaddr + i_offset, i_type); 353 print_function_pointer_address (options, 354 get_type_arch (type), 355 addr, stream); 356 } 357 } 358 else 359 { 360 struct value_print_options opts = *options; 361 362 opts.deref_ref = 0; 363 val_print (TYPE_FIELD_TYPE (type, i), 364 valaddr, 365 offset + TYPE_FIELD_BITPOS (type, i) / 8, 366 address, 367 stream, recurse + 1, val, &opts, 368 current_language); 369 } 370 } 371 annotate_field_end (); 372 } 373 374 if (dont_print_statmem == 0) 375 { 376 int obstack_final_size = 377 obstack_object_size (&dont_print_statmem_obstack); 378 379 if (obstack_final_size > statmem_obstack_initial_size) 380 { 381 /* In effect, a pop of the printed-statics stack. */ 382 383 void *free_to_ptr = 384 obstack_next_free (&dont_print_statmem_obstack) - 385 (obstack_final_size - statmem_obstack_initial_size); 386 387 obstack_free (&dont_print_statmem_obstack, 388 free_to_ptr); 389 } 390 391 if (last_set_recurse != recurse) 392 { 393 int obstack_final_size = 394 obstack_object_size (&dont_print_stat_array_obstack); 395 396 if (obstack_final_size > stat_array_obstack_initial_size) 397 { 398 void *free_to_ptr = 399 obstack_next_free (&dont_print_stat_array_obstack) 400 - (obstack_final_size 401 - stat_array_obstack_initial_size); 402 403 obstack_free (&dont_print_stat_array_obstack, 404 free_to_ptr); 405 } 406 last_set_recurse = -1; 407 } 408 } 409 410 if (options->pretty) 411 { 412 fprintf_filtered (stream, "\n"); 413 print_spaces_filtered (2 * recurse, stream); 414 } 415 } /* if there are data fields */ 416 417 fprintf_filtered (stream, "}"); 418 } 419 420 /* Like cp_print_value_fields, but find the runtime type of the object 421 and pass it as the `real_type' argument to cp_print_value_fields. 422 This function is a hack to work around the fact that 423 common_val_print passes the embedded offset to val_print, but not 424 the enclosing type. */ 425 426 void 427 cp_print_value_fields_rtti (struct type *type, 428 const gdb_byte *valaddr, int offset, 429 CORE_ADDR address, 430 struct ui_file *stream, int recurse, 431 const struct value *val, 432 const struct value_print_options *options, 433 struct type **dont_print_vb, 434 int dont_print_statmem) 435 { 436 struct type *real_type = NULL; 437 438 /* We require all bits to be valid in order to attempt a 439 conversion. */ 440 if (value_bits_valid (val, TARGET_CHAR_BIT * offset, 441 TARGET_CHAR_BIT * TYPE_LENGTH (type))) 442 { 443 struct value *value; 444 int full, top, using_enc; 445 446 /* Ugh, we have to convert back to a value here. */ 447 value = value_from_contents_and_address (type, valaddr + offset, 448 address + offset); 449 /* We don't actually care about most of the result here -- just 450 the type. We already have the correct offset, due to how 451 val_print was initially called. */ 452 real_type = value_rtti_type (value, &full, &top, &using_enc); 453 } 454 455 if (!real_type) 456 real_type = type; 457 458 cp_print_value_fields (type, real_type, valaddr, offset, 459 address, stream, recurse, val, options, 460 dont_print_vb, dont_print_statmem); 461 } 462 463 /* Special val_print routine to avoid printing multiple copies of 464 virtual baseclasses. */ 465 466 static void 467 cp_print_value (struct type *type, struct type *real_type, 468 const gdb_byte *valaddr, int offset, 469 CORE_ADDR address, struct ui_file *stream, 470 int recurse, const struct value *val, 471 const struct value_print_options *options, 472 struct type **dont_print_vb) 473 { 474 struct type **last_dont_print 475 = (struct type **) obstack_next_free (&dont_print_vb_obstack); 476 struct obstack tmp_obstack = dont_print_vb_obstack; 477 int i, n_baseclasses = TYPE_N_BASECLASSES (type); 478 int thisoffset; 479 struct type *thistype; 480 481 if (dont_print_vb == 0) 482 { 483 /* If we're at top level, carve out a completely fresh chunk of 484 the obstack and use that until this particular invocation 485 returns. */ 486 /* Bump up the high-water mark. Now alpha is omega. */ 487 obstack_finish (&dont_print_vb_obstack); 488 } 489 490 for (i = 0; i < n_baseclasses; i++) 491 { 492 int boffset = 0; 493 int skip; 494 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i)); 495 const char *basename = TYPE_NAME (baseclass); 496 const gdb_byte *base_valaddr = NULL; 497 const struct value *base_val = NULL; 498 volatile struct gdb_exception ex; 499 500 if (BASETYPE_VIA_VIRTUAL (type, i)) 501 { 502 struct type **first_dont_print 503 = (struct type **) obstack_base (&dont_print_vb_obstack); 504 505 int j = (struct type **) 506 obstack_next_free (&dont_print_vb_obstack) - first_dont_print; 507 508 while (--j >= 0) 509 if (baseclass == first_dont_print[j]) 510 goto flush_it; 511 512 obstack_ptr_grow (&dont_print_vb_obstack, baseclass); 513 } 514 515 thisoffset = offset; 516 thistype = real_type; 517 518 TRY_CATCH (ex, RETURN_MASK_ERROR) 519 { 520 boffset = baseclass_offset (type, i, valaddr, offset, address, val); 521 } 522 if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR) 523 skip = -1; 524 else if (ex.reason < 0) 525 skip = 1; 526 else 527 { 528 skip = 0; 529 530 if (BASETYPE_VIA_VIRTUAL (type, i)) 531 { 532 /* The virtual base class pointer might have been 533 clobbered by the user program. Make sure that it 534 still points to a valid memory location. */ 535 536 if ((boffset + offset) < 0 537 || (boffset + offset) >= TYPE_LENGTH (real_type)) 538 { 539 gdb_byte *buf; 540 struct cleanup *back_to; 541 542 buf = xmalloc (TYPE_LENGTH (baseclass)); 543 back_to = make_cleanup (xfree, buf); 544 545 if (target_read_memory (address + boffset, buf, 546 TYPE_LENGTH (baseclass)) != 0) 547 skip = 1; 548 base_val = value_from_contents_and_address (baseclass, 549 buf, 550 address + boffset); 551 thisoffset = 0; 552 boffset = 0; 553 thistype = baseclass; 554 base_valaddr = value_contents_for_printing_const (base_val); 555 do_cleanups (back_to); 556 } 557 else 558 { 559 base_valaddr = valaddr; 560 base_val = val; 561 } 562 } 563 else 564 { 565 base_valaddr = valaddr; 566 base_val = val; 567 } 568 } 569 570 /* Now do the printing. */ 571 if (options->pretty) 572 { 573 fprintf_filtered (stream, "\n"); 574 print_spaces_filtered (2 * recurse, stream); 575 } 576 fputs_filtered ("<", stream); 577 /* Not sure what the best notation is in the case where there is 578 no baseclass name. */ 579 fputs_filtered (basename ? basename : "", stream); 580 fputs_filtered ("> = ", stream); 581 582 if (skip < 0) 583 val_print_unavailable (stream); 584 else if (skip > 0) 585 val_print_invalid_address (stream); 586 else 587 { 588 int result = 0; 589 590 /* Attempt to run the Python pretty-printers on the 591 baseclass if possible. */ 592 if (!options->raw) 593 result = apply_val_pretty_printer (baseclass, base_valaddr, 594 thisoffset + boffset, 595 value_address (base_val), 596 stream, recurse, base_val, 597 options, current_language); 598 599 600 601 if (!result) 602 cp_print_value_fields (baseclass, thistype, base_valaddr, 603 thisoffset + boffset, 604 value_address (base_val), 605 stream, recurse, base_val, options, 606 ((struct type **) 607 obstack_base (&dont_print_vb_obstack)), 608 0); 609 } 610 fputs_filtered (", ", stream); 611 612 flush_it: 613 ; 614 } 615 616 if (dont_print_vb == 0) 617 { 618 /* Free the space used to deal with the printing 619 of this type from top level. */ 620 obstack_free (&dont_print_vb_obstack, last_dont_print); 621 /* Reset watermark so that we can continue protecting 622 ourselves from whatever we were protecting ourselves. */ 623 dont_print_vb_obstack = tmp_obstack; 624 } 625 } 626 627 /* Print value of a static member. To avoid infinite recursion when 628 printing a class that contains a static instance of the class, we 629 keep the addresses of all printed static member classes in an 630 obstack and refuse to print them more than once. 631 632 VAL contains the value to print, TYPE, STREAM, RECURSE, and OPTIONS 633 have the same meanings as in c_val_print. */ 634 635 static void 636 cp_print_static_field (struct type *type, 637 struct value *val, 638 struct ui_file *stream, 639 int recurse, 640 const struct value_print_options *options) 641 { 642 struct value_print_options opts; 643 644 if (TYPE_CODE (type) == TYPE_CODE_STRUCT) 645 { 646 CORE_ADDR *first_dont_print; 647 CORE_ADDR addr; 648 int i; 649 650 first_dont_print 651 = (CORE_ADDR *) obstack_base (&dont_print_statmem_obstack); 652 i = obstack_object_size (&dont_print_statmem_obstack) 653 / sizeof (CORE_ADDR); 654 655 while (--i >= 0) 656 { 657 if (value_address (val) == first_dont_print[i]) 658 { 659 fputs_filtered ("<same as static member of an already" 660 " seen type>", 661 stream); 662 return; 663 } 664 } 665 666 addr = value_address (val); 667 obstack_grow (&dont_print_statmem_obstack, (char *) &addr, 668 sizeof (CORE_ADDR)); 669 CHECK_TYPEDEF (type); 670 cp_print_value_fields (type, value_enclosing_type (val), 671 value_contents_for_printing (val), 672 value_embedded_offset (val), addr, 673 stream, recurse, val, 674 options, NULL, 1); 675 return; 676 } 677 678 if (TYPE_CODE (type) == TYPE_CODE_ARRAY) 679 { 680 struct type **first_dont_print; 681 int i; 682 struct type *target_type = TYPE_TARGET_TYPE (type); 683 684 first_dont_print 685 = (struct type **) obstack_base (&dont_print_stat_array_obstack); 686 i = obstack_object_size (&dont_print_stat_array_obstack) 687 / sizeof (struct type *); 688 689 while (--i >= 0) 690 { 691 if (target_type == first_dont_print[i]) 692 { 693 fputs_filtered ("<same as static member of an already" 694 " seen type>", 695 stream); 696 return; 697 } 698 } 699 700 obstack_grow (&dont_print_stat_array_obstack, 701 (char *) &target_type, 702 sizeof (struct type *)); 703 } 704 705 opts = *options; 706 opts.deref_ref = 0; 707 val_print (type, value_contents_for_printing (val), 708 value_embedded_offset (val), 709 value_address (val), 710 stream, recurse, val, 711 &opts, current_language); 712 } 713 714 715 /* Find the field in *DOMAIN, or its non-virtual base classes, with 716 bit offset OFFSET. Set *DOMAIN to the containing type and *FIELDNO 717 to the containing field number. If OFFSET is not exactly at the 718 start of some field, set *DOMAIN to NULL. */ 719 720 static void 721 cp_find_class_member (struct type **domain_p, int *fieldno, 722 LONGEST offset) 723 { 724 struct type *domain; 725 unsigned int i; 726 unsigned len; 727 728 *domain_p = check_typedef (*domain_p); 729 domain = *domain_p; 730 len = TYPE_NFIELDS (domain); 731 732 for (i = TYPE_N_BASECLASSES (domain); i < len; i++) 733 { 734 LONGEST bitpos = TYPE_FIELD_BITPOS (domain, i); 735 736 QUIT; 737 if (offset == bitpos) 738 { 739 *fieldno = i; 740 return; 741 } 742 } 743 744 for (i = 0; i < TYPE_N_BASECLASSES (domain); i++) 745 { 746 LONGEST bitpos = TYPE_FIELD_BITPOS (domain, i); 747 LONGEST bitsize = 8 * TYPE_LENGTH (TYPE_FIELD_TYPE (domain, i)); 748 749 if (offset >= bitpos && offset < bitpos + bitsize) 750 { 751 *domain_p = TYPE_FIELD_TYPE (domain, i); 752 cp_find_class_member (domain_p, fieldno, offset - bitpos); 753 return; 754 } 755 } 756 757 *domain_p = NULL; 758 } 759 760 void 761 cp_print_class_member (const gdb_byte *valaddr, struct type *type, 762 struct ui_file *stream, char *prefix) 763 { 764 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type)); 765 766 /* VAL is a byte offset into the structure type DOMAIN. 767 Find the name of the field for that offset and 768 print it. */ 769 struct type *domain = TYPE_DOMAIN_TYPE (type); 770 LONGEST val; 771 unsigned int fieldno; 772 773 val = extract_signed_integer (valaddr, 774 TYPE_LENGTH (type), 775 byte_order); 776 777 /* Pointers to data members are usually byte offsets into an object. 778 Because a data member can have offset zero, and a NULL pointer to 779 member must be distinct from any valid non-NULL pointer to 780 member, either the value is biased or the NULL value has a 781 special representation; both are permitted by ISO C++. HP aCC 782 used a bias of 0x20000000; HP cfront used a bias of 1; g++ 3.x 783 and other compilers which use the Itanium ABI use -1 as the NULL 784 value. GDB only supports that last form; to add support for 785 another form, make this into a cp-abi hook. */ 786 787 if (val == -1) 788 { 789 fprintf_filtered (stream, "NULL"); 790 return; 791 } 792 793 cp_find_class_member (&domain, &fieldno, val << 3); 794 795 if (domain != NULL) 796 { 797 const char *name; 798 799 fputs_filtered (prefix, stream); 800 name = type_name_no_tag (domain); 801 if (name) 802 fputs_filtered (name, stream); 803 else 804 c_type_print_base (domain, stream, 0, 0, &type_print_raw_options); 805 fprintf_filtered (stream, "::"); 806 fputs_filtered (TYPE_FIELD_NAME (domain, fieldno), stream); 807 } 808 else 809 fprintf_filtered (stream, "%ld", (long) val); 810 } 811 812 813 void 814 _initialize_cp_valprint (void) 815 { 816 add_setshow_boolean_cmd ("static-members", class_support, 817 &user_print_options.static_field_print, _("\ 818 Set printing of C++ static members."), _("\ 819 Show printing of C++ static members."), NULL, 820 NULL, 821 show_static_field_print, 822 &setprintlist, &showprintlist); 823 824 add_setshow_boolean_cmd ("vtbl", class_support, 825 &user_print_options.vtblprint, _("\ 826 Set printing of C++ virtual function tables."), _("\ 827 Show printing of C++ virtual function tables."), NULL, 828 NULL, 829 show_vtblprint, 830 &setprintlist, &showprintlist); 831 832 add_setshow_boolean_cmd ("object", class_support, 833 &user_print_options.objectprint, _("\ 834 Set printing of object's derived type based on vtable info."), _("\ 835 Show printing of object's derived type based on vtable info."), NULL, 836 NULL, 837 show_objectprint, 838 &setprintlist, &showprintlist); 839 840 obstack_begin (&dont_print_stat_array_obstack, 841 32 * sizeof (struct type *)); 842 obstack_begin (&dont_print_statmem_obstack, 843 32 * sizeof (CORE_ADDR)); 844 obstack_begin (&dont_print_vb_obstack, 845 32 * sizeof (struct type *)); 846 } 847