1 /* Support for printing C++ values for GDB, the GNU debugger. 2 3 Copyright (C) 1986, 1988-1989, 1991-1997, 2000-2003, 2005-2012 Free 4 Software Foundation, Inc. 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21 #include "defs.h" 22 #include "gdb_obstack.h" 23 #include "symtab.h" 24 #include "gdbtypes.h" 25 #include "expression.h" 26 #include "value.h" 27 #include "command.h" 28 #include "gdbcmd.h" 29 #include "demangle.h" 30 #include "annotate.h" 31 #include "gdb_string.h" 32 #include "c-lang.h" 33 #include "target.h" 34 #include "cp-abi.h" 35 #include "valprint.h" 36 #include "cp-support.h" 37 #include "language.h" 38 #include "python/python.h" 39 #include "exceptions.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 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; 213 214 if (dont_print_statmem == 0) 215 { 216 statmem_obstack_initial_size = 217 obstack_object_size (&dont_print_statmem_obstack); 218 219 if (last_set_recurse != recurse) 220 { 221 stat_array_obstack_initial_size = 222 obstack_object_size (&dont_print_stat_array_obstack); 223 224 last_set_recurse = recurse; 225 } 226 } 227 228 for (i = n_baseclasses; i < len; i++) 229 { 230 /* If requested, skip printing of static fields. */ 231 if (!options->static_field_print 232 && field_is_static (&TYPE_FIELD (type, i))) 233 continue; 234 235 if (fields_seen) 236 fprintf_filtered (stream, ", "); 237 else if (n_baseclasses > 0) 238 { 239 if (options->pretty) 240 { 241 fprintf_filtered (stream, "\n"); 242 print_spaces_filtered (2 + 2 * recurse, stream); 243 fputs_filtered ("members of ", stream); 244 fputs_filtered (type_name_no_tag (type), stream); 245 fputs_filtered (": ", stream); 246 } 247 } 248 fields_seen = 1; 249 250 if (options->pretty) 251 { 252 fprintf_filtered (stream, "\n"); 253 print_spaces_filtered (2 + 2 * recurse, stream); 254 } 255 else 256 { 257 wrap_here (n_spaces (2 + 2 * recurse)); 258 } 259 if (options->inspect_it) 260 { 261 if (TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_PTR) 262 fputs_filtered ("\"( ptr \"", stream); 263 else 264 fputs_filtered ("\"( nodef \"", stream); 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 fputs_filtered ("\" \"", stream); 272 fprintf_symbol_filtered (stream, 273 TYPE_FIELD_NAME (type, i), 274 current_language->la_language, 275 DMGL_PARAMS | DMGL_ANSI); 276 fputs_filtered ("\") \"", stream); 277 } 278 else 279 { 280 annotate_field_begin (TYPE_FIELD_TYPE (type, i)); 281 282 if (field_is_static (&TYPE_FIELD (type, i))) 283 fputs_filtered ("static ", stream); 284 fprintf_symbol_filtered (stream, 285 TYPE_FIELD_NAME (type, i), 286 current_language->la_language, 287 DMGL_PARAMS | DMGL_ANSI); 288 annotate_field_name_end (); 289 /* Do not print leading '=' in case of anonymous 290 unions. */ 291 if (strcmp (TYPE_FIELD_NAME (type, i), "")) 292 fputs_filtered (" = ", stream); 293 annotate_field_value (); 294 } 295 296 if (!field_is_static (&TYPE_FIELD (type, i)) 297 && TYPE_FIELD_PACKED (type, i)) 298 { 299 struct value *v; 300 301 /* Bitfields require special handling, especially due to 302 byte order problems. */ 303 if (TYPE_FIELD_IGNORE (type, i)) 304 { 305 fputs_filtered ("<optimized out or zero length>", stream); 306 } 307 else if (value_bits_synthetic_pointer (val, 308 TYPE_FIELD_BITPOS (type, 309 i), 310 TYPE_FIELD_BITSIZE (type, 311 i))) 312 { 313 fputs_filtered (_("<synthetic pointer>"), stream); 314 } 315 else if (!value_bits_valid (val, 316 TYPE_FIELD_BITPOS (type, i), 317 TYPE_FIELD_BITSIZE (type, i))) 318 { 319 val_print_optimized_out (stream); 320 } 321 else 322 { 323 struct value_print_options opts = *options; 324 325 opts.deref_ref = 0; 326 327 v = value_field_bitfield (type, i, valaddr, offset, val); 328 329 common_val_print (v, stream, recurse + 1, &opts, 330 current_language); 331 } 332 } 333 else 334 { 335 if (TYPE_FIELD_IGNORE (type, i)) 336 { 337 fputs_filtered ("<optimized out or zero length>", 338 stream); 339 } 340 else if (field_is_static (&TYPE_FIELD (type, i))) 341 { 342 volatile struct gdb_exception ex; 343 struct value *v = NULL; 344 345 TRY_CATCH (ex, RETURN_MASK_ERROR) 346 { 347 v = value_static_field (type, i); 348 } 349 350 if (ex.reason < 0) 351 fprintf_filtered (stream, 352 _("<error reading variable: %s>"), 353 ex.message); 354 else if (v == NULL) 355 val_print_optimized_out (stream); 356 else 357 cp_print_static_field (TYPE_FIELD_TYPE (type, i), 358 v, stream, recurse + 1, 359 options); 360 } 361 else 362 { 363 struct value_print_options opts = *options; 364 365 opts.deref_ref = 0; 366 val_print (TYPE_FIELD_TYPE (type, i), 367 valaddr, 368 offset + TYPE_FIELD_BITPOS (type, i) / 8, 369 address, 370 stream, recurse + 1, val, &opts, 371 current_language); 372 } 373 } 374 annotate_field_end (); 375 } 376 377 if (dont_print_statmem == 0) 378 { 379 int obstack_final_size = 380 obstack_object_size (&dont_print_statmem_obstack); 381 382 if (obstack_final_size > statmem_obstack_initial_size) 383 { 384 /* In effect, a pop of the printed-statics stack. */ 385 386 void *free_to_ptr = 387 obstack_next_free (&dont_print_statmem_obstack) - 388 (obstack_final_size - statmem_obstack_initial_size); 389 390 obstack_free (&dont_print_statmem_obstack, 391 free_to_ptr); 392 } 393 394 if (last_set_recurse != recurse) 395 { 396 int obstack_final_size = 397 obstack_object_size (&dont_print_stat_array_obstack); 398 399 if (obstack_final_size > stat_array_obstack_initial_size) 400 { 401 void *free_to_ptr = 402 obstack_next_free (&dont_print_stat_array_obstack) 403 - (obstack_final_size 404 - stat_array_obstack_initial_size); 405 406 obstack_free (&dont_print_stat_array_obstack, 407 free_to_ptr); 408 } 409 last_set_recurse = -1; 410 } 411 } 412 413 if (options->pretty) 414 { 415 fprintf_filtered (stream, "\n"); 416 print_spaces_filtered (2 * recurse, stream); 417 } 418 } /* if there are data fields */ 419 420 fprintf_filtered (stream, "}"); 421 } 422 423 /* Like cp_print_value_fields, but find the runtime type of the object 424 and pass it as the `real_type' argument to cp_print_value_fields. 425 This function is a hack to work around the fact that 426 common_val_print passes the embedded offset to val_print, but not 427 the enclosing type. */ 428 429 void 430 cp_print_value_fields_rtti (struct type *type, 431 const gdb_byte *valaddr, int offset, 432 CORE_ADDR address, 433 struct ui_file *stream, int recurse, 434 const struct value *val, 435 const struct value_print_options *options, 436 struct type **dont_print_vb, 437 int dont_print_statmem) 438 { 439 struct type *real_type = NULL; 440 441 /* We require all bits to be valid in order to attempt a 442 conversion. */ 443 if (value_bits_valid (val, TARGET_CHAR_BIT * offset, 444 TARGET_CHAR_BIT * TYPE_LENGTH (type))) 445 { 446 struct value *value; 447 int full, top, using_enc; 448 449 /* Ugh, we have to convert back to a value here. */ 450 value = value_from_contents_and_address (type, valaddr + offset, 451 address + offset); 452 /* We don't actually care about most of the result here -- just 453 the type. We already have the correct offset, due to how 454 val_print was initially called. */ 455 real_type = value_rtti_type (value, &full, &top, &using_enc); 456 } 457 458 if (!real_type) 459 real_type = type; 460 461 cp_print_value_fields (type, real_type, valaddr, offset, 462 address, stream, recurse, val, options, 463 dont_print_vb, dont_print_statmem); 464 } 465 466 /* Special val_print routine to avoid printing multiple copies of 467 virtual baseclasses. */ 468 469 static void 470 cp_print_value (struct type *type, struct type *real_type, 471 const gdb_byte *valaddr, int offset, 472 CORE_ADDR address, struct ui_file *stream, 473 int recurse, const struct value *val, 474 const struct value_print_options *options, 475 struct type **dont_print_vb) 476 { 477 struct type **last_dont_print 478 = (struct type **) obstack_next_free (&dont_print_vb_obstack); 479 struct obstack tmp_obstack = dont_print_vb_obstack; 480 int i, n_baseclasses = TYPE_N_BASECLASSES (type); 481 int thisoffset; 482 struct type *thistype; 483 484 if (dont_print_vb == 0) 485 { 486 /* If we're at top level, carve out a completely fresh chunk of 487 the obstack and use that until this particular invocation 488 returns. */ 489 /* Bump up the high-water mark. Now alpha is omega. */ 490 obstack_finish (&dont_print_vb_obstack); 491 } 492 493 for (i = 0; i < n_baseclasses; i++) 494 { 495 int boffset = 0; 496 int skip; 497 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i)); 498 char *basename = TYPE_NAME (baseclass); 499 const gdb_byte *base_valaddr = NULL; 500 const struct value *base_val = NULL; 501 volatile struct gdb_exception ex; 502 503 if (BASETYPE_VIA_VIRTUAL (type, i)) 504 { 505 struct type **first_dont_print 506 = (struct type **) obstack_base (&dont_print_vb_obstack); 507 508 int j = (struct type **) 509 obstack_next_free (&dont_print_vb_obstack) - first_dont_print; 510 511 while (--j >= 0) 512 if (baseclass == first_dont_print[j]) 513 goto flush_it; 514 515 obstack_ptr_grow (&dont_print_vb_obstack, baseclass); 516 } 517 518 thisoffset = offset; 519 thistype = real_type; 520 521 TRY_CATCH (ex, RETURN_MASK_ERROR) 522 { 523 boffset = baseclass_offset (type, i, valaddr, offset, address, val); 524 } 525 if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR) 526 skip = -1; 527 else if (ex.reason < 0) 528 skip = 1; 529 else 530 { 531 skip = 0; 532 533 if (BASETYPE_VIA_VIRTUAL (type, i)) 534 { 535 /* The virtual base class pointer might have been 536 clobbered by the user program. Make sure that it 537 still points to a valid memory location. */ 538 539 if ((boffset + offset) < 0 540 || (boffset + offset) >= TYPE_LENGTH (real_type)) 541 { 542 /* FIXME (alloca): unsafe if baseclass is really 543 really large. */ 544 gdb_byte *buf = alloca (TYPE_LENGTH (baseclass)); 545 546 if (target_read_memory (address + boffset, buf, 547 TYPE_LENGTH (baseclass)) != 0) 548 skip = 1; 549 base_val = value_from_contents_and_address (baseclass, 550 buf, 551 address + boffset); 552 thisoffset = 0; 553 boffset = 0; 554 thistype = baseclass; 555 base_valaddr = value_contents_for_printing_const (base_val); 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 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); 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