| 1 | /* Abstraction of GNU v3 abi. |
| 2 | Contributed by Jim Blandy <jimb@redhat.com> |
| 3 | |
| 4 | Copyright (C) 2001-2019 Free 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 "value.h" |
| 23 | #include "cp-abi.h" |
| 24 | #include "cp-support.h" |
| 25 | #include "demangle.h" |
| 26 | #include "objfiles.h" |
| 27 | #include "valprint.h" |
| 28 | #include "c-lang.h" |
| 29 | #include "typeprint.h" |
| 30 | #include <algorithm> |
| 31 | |
| 32 | static struct cp_abi_ops gnu_v3_abi_ops; |
| 33 | |
| 34 | /* A gdbarch key for std::type_info, in the event that it can't be |
| 35 | found in the debug info. */ |
| 36 | |
| 37 | static struct gdbarch_data *std_type_info_gdbarch_data; |
| 38 | |
| 39 | |
| 40 | static int |
| 41 | gnuv3_is_vtable_name (const char *name) |
| 42 | { |
| 43 | return startswith (name, "_ZTV"); |
| 44 | } |
| 45 | |
| 46 | static int |
| 47 | gnuv3_is_operator_name (const char *name) |
| 48 | { |
| 49 | return startswith (name, CP_OPERATOR_STR); |
| 50 | } |
| 51 | |
| 52 | |
| 53 | /* To help us find the components of a vtable, we build ourselves a |
| 54 | GDB type object representing the vtable structure. Following the |
| 55 | V3 ABI, it goes something like this: |
| 56 | |
| 57 | struct gdb_gnu_v3_abi_vtable { |
| 58 | |
| 59 | / * An array of virtual call and virtual base offsets. The real |
| 60 | length of this array depends on the class hierarchy; we use |
| 61 | negative subscripts to access the elements. Yucky, but |
| 62 | better than the alternatives. * / |
| 63 | ptrdiff_t vcall_and_vbase_offsets[0]; |
| 64 | |
| 65 | / * The offset from a virtual pointer referring to this table |
| 66 | to the top of the complete object. * / |
| 67 | ptrdiff_t offset_to_top; |
| 68 | |
| 69 | / * The type_info pointer for this class. This is really a |
| 70 | std::type_info *, but GDB doesn't really look at the |
| 71 | type_info object itself, so we don't bother to get the type |
| 72 | exactly right. * / |
| 73 | void *type_info; |
| 74 | |
| 75 | / * Virtual table pointers in objects point here. * / |
| 76 | |
| 77 | / * Virtual function pointers. Like the vcall/vbase array, the |
| 78 | real length of this table depends on the class hierarchy. * / |
| 79 | void (*virtual_functions[0]) (); |
| 80 | |
| 81 | }; |
| 82 | |
| 83 | The catch, of course, is that the exact layout of this table |
| 84 | depends on the ABI --- word size, endianness, alignment, etc. So |
| 85 | the GDB type object is actually a per-architecture kind of thing. |
| 86 | |
| 87 | vtable_type_gdbarch_data is a gdbarch per-architecture data pointer |
| 88 | which refers to the struct type * for this structure, laid out |
| 89 | appropriately for the architecture. */ |
| 90 | static struct gdbarch_data *vtable_type_gdbarch_data; |
| 91 | |
| 92 | |
| 93 | /* Human-readable names for the numbers of the fields above. */ |
| 94 | enum { |
| 95 | vtable_field_vcall_and_vbase_offsets, |
| 96 | vtable_field_offset_to_top, |
| 97 | vtable_field_type_info, |
| 98 | vtable_field_virtual_functions |
| 99 | }; |
| 100 | |
| 101 | |
| 102 | /* Return a GDB type representing `struct gdb_gnu_v3_abi_vtable', |
| 103 | described above, laid out appropriately for ARCH. |
| 104 | |
| 105 | We use this function as the gdbarch per-architecture data |
| 106 | initialization function. */ |
| 107 | static void * |
| 108 | build_gdb_vtable_type (struct gdbarch *arch) |
| 109 | { |
| 110 | struct type *t; |
| 111 | struct field *field_list, *field; |
| 112 | int offset; |
| 113 | |
| 114 | struct type *void_ptr_type |
| 115 | = builtin_type (arch)->builtin_data_ptr; |
| 116 | struct type *ptr_to_void_fn_type |
| 117 | = builtin_type (arch)->builtin_func_ptr; |
| 118 | |
| 119 | /* ARCH can't give us the true ptrdiff_t type, so we guess. */ |
| 120 | struct type *ptrdiff_type |
| 121 | = arch_integer_type (arch, gdbarch_ptr_bit (arch), 0, "ptrdiff_t"); |
| 122 | |
| 123 | /* We assume no padding is necessary, since GDB doesn't know |
| 124 | anything about alignment at the moment. If this assumption bites |
| 125 | us, we should add a gdbarch method which, given a type, returns |
| 126 | the alignment that type requires, and then use that here. */ |
| 127 | |
| 128 | /* Build the field list. */ |
| 129 | field_list = XCNEWVEC (struct field, 4); |
| 130 | field = &field_list[0]; |
| 131 | offset = 0; |
| 132 | |
| 133 | /* ptrdiff_t vcall_and_vbase_offsets[0]; */ |
| 134 | FIELD_NAME (*field) = "vcall_and_vbase_offsets"; |
| 135 | FIELD_TYPE (*field) = lookup_array_range_type (ptrdiff_type, 0, -1); |
| 136 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 137 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 138 | field++; |
| 139 | |
| 140 | /* ptrdiff_t offset_to_top; */ |
| 141 | FIELD_NAME (*field) = "offset_to_top"; |
| 142 | FIELD_TYPE (*field) = ptrdiff_type; |
| 143 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 144 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 145 | field++; |
| 146 | |
| 147 | /* void *type_info; */ |
| 148 | FIELD_NAME (*field) = "type_info"; |
| 149 | FIELD_TYPE (*field) = void_ptr_type; |
| 150 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 151 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 152 | field++; |
| 153 | |
| 154 | /* void (*virtual_functions[0]) (); */ |
| 155 | FIELD_NAME (*field) = "virtual_functions"; |
| 156 | FIELD_TYPE (*field) = lookup_array_range_type (ptr_to_void_fn_type, 0, -1); |
| 157 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 158 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 159 | field++; |
| 160 | |
| 161 | /* We assumed in the allocation above that there were four fields. */ |
| 162 | gdb_assert (field == (field_list + 4)); |
| 163 | |
| 164 | t = arch_type (arch, TYPE_CODE_STRUCT, offset * TARGET_CHAR_BIT, NULL); |
| 165 | TYPE_NFIELDS (t) = field - field_list; |
| 166 | TYPE_FIELDS (t) = field_list; |
| 167 | TYPE_NAME (t) = "gdb_gnu_v3_abi_vtable"; |
| 168 | INIT_CPLUS_SPECIFIC (t); |
| 169 | |
| 170 | return make_type_with_address_space (t, TYPE_INSTANCE_FLAG_CODE_SPACE); |
| 171 | } |
| 172 | |
| 173 | |
| 174 | /* Return the ptrdiff_t type used in the vtable type. */ |
| 175 | static struct type * |
| 176 | vtable_ptrdiff_type (struct gdbarch *gdbarch) |
| 177 | { |
| 178 | struct type *vtable_type |
| 179 | = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| 180 | |
| 181 | /* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */ |
| 182 | return TYPE_FIELD_TYPE (vtable_type, vtable_field_offset_to_top); |
| 183 | } |
| 184 | |
| 185 | /* Return the offset from the start of the imaginary `struct |
| 186 | gdb_gnu_v3_abi_vtable' object to the vtable's "address point" |
| 187 | (i.e., where objects' virtual table pointers point). */ |
| 188 | static int |
| 189 | vtable_address_point_offset (struct gdbarch *gdbarch) |
| 190 | { |
| 191 | struct type *vtable_type |
| 192 | = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| 193 | |
| 194 | return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions) |
| 195 | / TARGET_CHAR_BIT); |
| 196 | } |
| 197 | |
| 198 | |
| 199 | /* Determine whether structure TYPE is a dynamic class. Cache the |
| 200 | result. */ |
| 201 | |
| 202 | static int |
| 203 | gnuv3_dynamic_class (struct type *type) |
| 204 | { |
| 205 | int fieldnum, fieldelem; |
| 206 | |
| 207 | type = check_typedef (type); |
| 208 | gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 209 | || TYPE_CODE (type) == TYPE_CODE_UNION); |
| 210 | |
| 211 | if (TYPE_CODE (type) == TYPE_CODE_UNION) |
| 212 | return 0; |
| 213 | |
| 214 | if (TYPE_CPLUS_DYNAMIC (type)) |
| 215 | return TYPE_CPLUS_DYNAMIC (type) == 1; |
| 216 | |
| 217 | ALLOCATE_CPLUS_STRUCT_TYPE (type); |
| 218 | |
| 219 | for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++) |
| 220 | if (BASETYPE_VIA_VIRTUAL (type, fieldnum) |
| 221 | || gnuv3_dynamic_class (TYPE_FIELD_TYPE (type, fieldnum))) |
| 222 | { |
| 223 | TYPE_CPLUS_DYNAMIC (type) = 1; |
| 224 | return 1; |
| 225 | } |
| 226 | |
| 227 | for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++) |
| 228 | for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum); |
| 229 | fieldelem++) |
| 230 | { |
| 231 | struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum); |
| 232 | |
| 233 | if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem)) |
| 234 | { |
| 235 | TYPE_CPLUS_DYNAMIC (type) = 1; |
| 236 | return 1; |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | TYPE_CPLUS_DYNAMIC (type) = -1; |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | /* Find the vtable for a value of CONTAINER_TYPE located at |
| 245 | CONTAINER_ADDR. Return a value of the correct vtable type for this |
| 246 | architecture, or NULL if CONTAINER does not have a vtable. */ |
| 247 | |
| 248 | static struct value * |
| 249 | gnuv3_get_vtable (struct gdbarch *gdbarch, |
| 250 | struct type *container_type, CORE_ADDR container_addr) |
| 251 | { |
| 252 | struct type *vtable_type |
| 253 | = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data); |
| 254 | struct type *vtable_pointer_type; |
| 255 | struct value *vtable_pointer; |
| 256 | CORE_ADDR vtable_address; |
| 257 | |
| 258 | container_type = check_typedef (container_type); |
| 259 | gdb_assert (TYPE_CODE (container_type) == TYPE_CODE_STRUCT); |
| 260 | |
| 261 | /* If this type does not have a virtual table, don't read the first |
| 262 | field. */ |
| 263 | if (!gnuv3_dynamic_class (container_type)) |
| 264 | return NULL; |
| 265 | |
| 266 | /* We do not consult the debug information to find the virtual table. |
| 267 | The ABI specifies that it is always at offset zero in any class, |
| 268 | and debug information may not represent it. |
| 269 | |
| 270 | We avoid using value_contents on principle, because the object might |
| 271 | be large. */ |
| 272 | |
| 273 | /* Find the type "pointer to virtual table". */ |
| 274 | vtable_pointer_type = lookup_pointer_type (vtable_type); |
| 275 | |
| 276 | /* Load it from the start of the class. */ |
| 277 | vtable_pointer = value_at (vtable_pointer_type, container_addr); |
| 278 | vtable_address = value_as_address (vtable_pointer); |
| 279 | |
| 280 | /* Correct it to point at the start of the virtual table, rather |
| 281 | than the address point. */ |
| 282 | return value_at_lazy (vtable_type, |
| 283 | vtable_address |
| 284 | - vtable_address_point_offset (gdbarch)); |
| 285 | } |
| 286 | |
| 287 | |
| 288 | static struct type * |
| 289 | gnuv3_rtti_type (struct value *value, |
| 290 | int *full_p, LONGEST *top_p, int *using_enc_p) |
| 291 | { |
| 292 | struct gdbarch *gdbarch; |
| 293 | struct type *values_type = check_typedef (value_type (value)); |
| 294 | struct value *vtable; |
| 295 | struct minimal_symbol *vtable_symbol; |
| 296 | const char *vtable_symbol_name; |
| 297 | const char *class_name; |
| 298 | struct type *run_time_type; |
| 299 | LONGEST offset_to_top; |
| 300 | const char *atsign; |
| 301 | |
| 302 | /* We only have RTTI for dynamic class objects. */ |
| 303 | if (TYPE_CODE (values_type) != TYPE_CODE_STRUCT |
| 304 | || !gnuv3_dynamic_class (values_type)) |
| 305 | return NULL; |
| 306 | |
| 307 | /* Determine architecture. */ |
| 308 | gdbarch = get_type_arch (values_type); |
| 309 | |
| 310 | if (using_enc_p) |
| 311 | *using_enc_p = 0; |
| 312 | |
| 313 | vtable = gnuv3_get_vtable (gdbarch, values_type, |
| 314 | value_as_address (value_addr (value))); |
| 315 | if (vtable == NULL) |
| 316 | return NULL; |
| 317 | |
| 318 | /* Find the linker symbol for this vtable. */ |
| 319 | vtable_symbol |
| 320 | = lookup_minimal_symbol_by_pc (value_address (vtable) |
| 321 | + value_embedded_offset (vtable)).minsym; |
| 322 | if (! vtable_symbol) |
| 323 | return NULL; |
| 324 | |
| 325 | /* The symbol's demangled name should be something like "vtable for |
| 326 | CLASS", where CLASS is the name of the run-time type of VALUE. |
| 327 | If we didn't like this approach, we could instead look in the |
| 328 | type_info object itself to get the class name. But this way |
| 329 | should work just as well, and doesn't read target memory. */ |
| 330 | vtable_symbol_name = MSYMBOL_DEMANGLED_NAME (vtable_symbol); |
| 331 | if (vtable_symbol_name == NULL |
| 332 | || !startswith (vtable_symbol_name, "vtable for ")) |
| 333 | { |
| 334 | warning (_("can't find linker symbol for virtual table for `%s' value"), |
| 335 | TYPE_SAFE_NAME (values_type)); |
| 336 | if (vtable_symbol_name) |
| 337 | warning (_(" found `%s' instead"), vtable_symbol_name); |
| 338 | return NULL; |
| 339 | } |
| 340 | class_name = vtable_symbol_name + 11; |
| 341 | |
| 342 | /* Strip off @plt and version suffixes. */ |
| 343 | atsign = strchr (class_name, '@'); |
| 344 | if (atsign != NULL) |
| 345 | { |
| 346 | char *copy; |
| 347 | |
| 348 | copy = (char *) alloca (atsign - class_name + 1); |
| 349 | memcpy (copy, class_name, atsign - class_name); |
| 350 | copy[atsign - class_name] = '\0'; |
| 351 | class_name = copy; |
| 352 | } |
| 353 | |
| 354 | /* Try to look up the class name as a type name. */ |
| 355 | /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */ |
| 356 | run_time_type = cp_lookup_rtti_type (class_name, NULL); |
| 357 | if (run_time_type == NULL) |
| 358 | return NULL; |
| 359 | |
| 360 | /* Get the offset from VALUE to the top of the complete object. |
| 361 | NOTE: this is the reverse of the meaning of *TOP_P. */ |
| 362 | offset_to_top |
| 363 | = value_as_long (value_field (vtable, vtable_field_offset_to_top)); |
| 364 | |
| 365 | if (full_p) |
| 366 | *full_p = (- offset_to_top == value_embedded_offset (value) |
| 367 | && (TYPE_LENGTH (value_enclosing_type (value)) |
| 368 | >= TYPE_LENGTH (run_time_type))); |
| 369 | if (top_p) |
| 370 | *top_p = - offset_to_top; |
| 371 | return run_time_type; |
| 372 | } |
| 373 | |
| 374 | /* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual |
| 375 | function, of type FNTYPE. */ |
| 376 | |
| 377 | static struct value * |
| 378 | gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container, |
| 379 | struct type *fntype, int vtable_index) |
| 380 | { |
| 381 | struct value *vtable, *vfn; |
| 382 | |
| 383 | /* Every class with virtual functions must have a vtable. */ |
| 384 | vtable = gnuv3_get_vtable (gdbarch, value_type (container), |
| 385 | value_as_address (value_addr (container))); |
| 386 | gdb_assert (vtable != NULL); |
| 387 | |
| 388 | /* Fetch the appropriate function pointer from the vtable. */ |
| 389 | vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions), |
| 390 | vtable_index); |
| 391 | |
| 392 | /* If this architecture uses function descriptors directly in the vtable, |
| 393 | then the address of the vtable entry is actually a "function pointer" |
| 394 | (i.e. points to the descriptor). We don't need to scale the index |
| 395 | by the size of a function descriptor; GCC does that before outputing |
| 396 | debug information. */ |
| 397 | if (gdbarch_vtable_function_descriptors (gdbarch)) |
| 398 | vfn = value_addr (vfn); |
| 399 | |
| 400 | /* Cast the function pointer to the appropriate type. */ |
| 401 | vfn = value_cast (lookup_pointer_type (fntype), vfn); |
| 402 | |
| 403 | return vfn; |
| 404 | } |
| 405 | |
| 406 | /* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h |
| 407 | for a description of the arguments. */ |
| 408 | |
| 409 | static struct value * |
| 410 | gnuv3_virtual_fn_field (struct value **value_p, |
| 411 | struct fn_field *f, int j, |
| 412 | struct type *vfn_base, int offset) |
| 413 | { |
| 414 | struct type *values_type = check_typedef (value_type (*value_p)); |
| 415 | struct gdbarch *gdbarch; |
| 416 | |
| 417 | /* Some simple sanity checks. */ |
| 418 | if (TYPE_CODE (values_type) != TYPE_CODE_STRUCT) |
| 419 | error (_("Only classes can have virtual functions.")); |
| 420 | |
| 421 | /* Determine architecture. */ |
| 422 | gdbarch = get_type_arch (values_type); |
| 423 | |
| 424 | /* Cast our value to the base class which defines this virtual |
| 425 | function. This takes care of any necessary `this' |
| 426 | adjustments. */ |
| 427 | if (vfn_base != values_type) |
| 428 | *value_p = value_cast (vfn_base, *value_p); |
| 429 | |
| 430 | return gnuv3_get_virtual_fn (gdbarch, *value_p, TYPE_FN_FIELD_TYPE (f, j), |
| 431 | TYPE_FN_FIELD_VOFFSET (f, j)); |
| 432 | } |
| 433 | |
| 434 | /* Compute the offset of the baseclass which is |
| 435 | the INDEXth baseclass of class TYPE, |
| 436 | for value at VALADDR (in host) at ADDRESS (in target). |
| 437 | The result is the offset of the baseclass value relative |
| 438 | to (the address of)(ARG) + OFFSET. |
| 439 | |
| 440 | -1 is returned on error. */ |
| 441 | |
| 442 | static int |
| 443 | gnuv3_baseclass_offset (struct type *type, int index, |
| 444 | const bfd_byte *valaddr, LONGEST embedded_offset, |
| 445 | CORE_ADDR address, const struct value *val) |
| 446 | { |
| 447 | struct gdbarch *gdbarch; |
| 448 | struct type *ptr_type; |
| 449 | struct value *vtable; |
| 450 | struct value *vbase_array; |
| 451 | long int cur_base_offset, base_offset; |
| 452 | |
| 453 | /* Determine architecture. */ |
| 454 | gdbarch = get_type_arch (type); |
| 455 | ptr_type = builtin_type (gdbarch)->builtin_data_ptr; |
| 456 | |
| 457 | /* If it isn't a virtual base, this is easy. The offset is in the |
| 458 | type definition. */ |
| 459 | if (!BASETYPE_VIA_VIRTUAL (type, index)) |
| 460 | return TYPE_BASECLASS_BITPOS (type, index) / 8; |
| 461 | |
| 462 | /* To access a virtual base, we need to use the vbase offset stored in |
| 463 | our vtable. Recent GCC versions provide this information. If it isn't |
| 464 | available, we could get what we needed from RTTI, or from drawing the |
| 465 | complete inheritance graph based on the debug info. Neither is |
| 466 | worthwhile. */ |
| 467 | cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8; |
| 468 | if (cur_base_offset >= - vtable_address_point_offset (gdbarch)) |
| 469 | error (_("Expected a negative vbase offset (old compiler?)")); |
| 470 | |
| 471 | cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch); |
| 472 | if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0) |
| 473 | error (_("Misaligned vbase offset.")); |
| 474 | cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type)); |
| 475 | |
| 476 | vtable = gnuv3_get_vtable (gdbarch, type, address + embedded_offset); |
| 477 | gdb_assert (vtable != NULL); |
| 478 | vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets); |
| 479 | base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset)); |
| 480 | return base_offset; |
| 481 | } |
| 482 | |
| 483 | /* Locate a virtual method in DOMAIN or its non-virtual base classes |
| 484 | which has virtual table index VOFFSET. The method has an associated |
| 485 | "this" adjustment of ADJUSTMENT bytes. */ |
| 486 | |
| 487 | static const char * |
| 488 | gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset, |
| 489 | LONGEST adjustment) |
| 490 | { |
| 491 | int i; |
| 492 | |
| 493 | /* Search this class first. */ |
| 494 | if (adjustment == 0) |
| 495 | { |
| 496 | int len; |
| 497 | |
| 498 | len = TYPE_NFN_FIELDS (domain); |
| 499 | for (i = 0; i < len; i++) |
| 500 | { |
| 501 | int len2, j; |
| 502 | struct fn_field *f; |
| 503 | |
| 504 | f = TYPE_FN_FIELDLIST1 (domain, i); |
| 505 | len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i); |
| 506 | |
| 507 | check_stub_method_group (domain, i); |
| 508 | for (j = 0; j < len2; j++) |
| 509 | if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset) |
| 510 | return TYPE_FN_FIELD_PHYSNAME (f, j); |
| 511 | } |
| 512 | } |
| 513 | |
| 514 | /* Next search non-virtual bases. If it's in a virtual base, |
| 515 | we're out of luck. */ |
| 516 | for (i = 0; i < TYPE_N_BASECLASSES (domain); i++) |
| 517 | { |
| 518 | int pos; |
| 519 | struct type *basetype; |
| 520 | |
| 521 | if (BASETYPE_VIA_VIRTUAL (domain, i)) |
| 522 | continue; |
| 523 | |
| 524 | pos = TYPE_BASECLASS_BITPOS (domain, i) / 8; |
| 525 | basetype = TYPE_FIELD_TYPE (domain, i); |
| 526 | /* Recurse with a modified adjustment. We don't need to adjust |
| 527 | voffset. */ |
| 528 | if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype)) |
| 529 | return gnuv3_find_method_in (basetype, voffset, adjustment - pos); |
| 530 | } |
| 531 | |
| 532 | return NULL; |
| 533 | } |
| 534 | |
| 535 | /* Decode GNU v3 method pointer. */ |
| 536 | |
| 537 | static int |
| 538 | gnuv3_decode_method_ptr (struct gdbarch *gdbarch, |
| 539 | const gdb_byte *contents, |
| 540 | CORE_ADDR *value_p, |
| 541 | LONGEST *adjustment_p) |
| 542 | { |
| 543 | struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr; |
| 544 | struct type *offset_type = vtable_ptrdiff_type (gdbarch); |
| 545 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 546 | CORE_ADDR ptr_value; |
| 547 | LONGEST voffset, adjustment; |
| 548 | int vbit; |
| 549 | |
| 550 | /* Extract the pointer to member. The first element is either a pointer |
| 551 | or a vtable offset. For pointers, we need to use extract_typed_address |
| 552 | to allow the back-end to convert the pointer to a GDB address -- but |
| 553 | vtable offsets we must handle as integers. At this point, we do not |
| 554 | yet know which case we have, so we extract the value under both |
| 555 | interpretations and choose the right one later on. */ |
| 556 | ptr_value = extract_typed_address (contents, funcptr_type); |
| 557 | voffset = extract_signed_integer (contents, |
| 558 | TYPE_LENGTH (funcptr_type), byte_order); |
| 559 | contents += TYPE_LENGTH (funcptr_type); |
| 560 | adjustment = extract_signed_integer (contents, |
| 561 | TYPE_LENGTH (offset_type), byte_order); |
| 562 | |
| 563 | if (!gdbarch_vbit_in_delta (gdbarch)) |
| 564 | { |
| 565 | vbit = voffset & 1; |
| 566 | voffset = voffset ^ vbit; |
| 567 | } |
| 568 | else |
| 569 | { |
| 570 | vbit = adjustment & 1; |
| 571 | adjustment = adjustment >> 1; |
| 572 | } |
| 573 | |
| 574 | *value_p = vbit? voffset : ptr_value; |
| 575 | *adjustment_p = adjustment; |
| 576 | return vbit; |
| 577 | } |
| 578 | |
| 579 | /* GNU v3 implementation of cplus_print_method_ptr. */ |
| 580 | |
| 581 | static void |
| 582 | gnuv3_print_method_ptr (const gdb_byte *contents, |
| 583 | struct type *type, |
| 584 | struct ui_file *stream) |
| 585 | { |
| 586 | struct type *self_type = TYPE_SELF_TYPE (type); |
| 587 | struct gdbarch *gdbarch = get_type_arch (self_type); |
| 588 | CORE_ADDR ptr_value; |
| 589 | LONGEST adjustment; |
| 590 | int vbit; |
| 591 | |
| 592 | /* Extract the pointer to member. */ |
| 593 | vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment); |
| 594 | |
| 595 | /* Check for NULL. */ |
| 596 | if (ptr_value == 0 && vbit == 0) |
| 597 | { |
| 598 | fprintf_filtered (stream, "NULL"); |
| 599 | return; |
| 600 | } |
| 601 | |
| 602 | /* Search for a virtual method. */ |
| 603 | if (vbit) |
| 604 | { |
| 605 | CORE_ADDR voffset; |
| 606 | const char *physname; |
| 607 | |
| 608 | /* It's a virtual table offset, maybe in this class. Search |
| 609 | for a field with the correct vtable offset. First convert it |
| 610 | to an index, as used in TYPE_FN_FIELD_VOFFSET. */ |
| 611 | voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch)); |
| 612 | |
| 613 | physname = gnuv3_find_method_in (self_type, voffset, adjustment); |
| 614 | |
| 615 | /* If we found a method, print that. We don't bother to disambiguate |
| 616 | possible paths to the method based on the adjustment. */ |
| 617 | if (physname) |
| 618 | { |
| 619 | char *demangled_name = gdb_demangle (physname, |
| 620 | DMGL_ANSI | DMGL_PARAMS); |
| 621 | |
| 622 | fprintf_filtered (stream, "&virtual "); |
| 623 | if (demangled_name == NULL) |
| 624 | fputs_filtered (physname, stream); |
| 625 | else |
| 626 | { |
| 627 | fputs_filtered (demangled_name, stream); |
| 628 | xfree (demangled_name); |
| 629 | } |
| 630 | return; |
| 631 | } |
| 632 | } |
| 633 | else if (ptr_value != 0) |
| 634 | { |
| 635 | /* Found a non-virtual function: print out the type. */ |
| 636 | fputs_filtered ("(", stream); |
| 637 | c_print_type (type, "", stream, -1, 0, &type_print_raw_options); |
| 638 | fputs_filtered (") ", stream); |
| 639 | } |
| 640 | |
| 641 | /* We didn't find it; print the raw data. */ |
| 642 | if (vbit) |
| 643 | { |
| 644 | fprintf_filtered (stream, "&virtual table offset "); |
| 645 | print_longest (stream, 'd', 1, ptr_value); |
| 646 | } |
| 647 | else |
| 648 | { |
| 649 | struct value_print_options opts; |
| 650 | |
| 651 | get_user_print_options (&opts); |
| 652 | print_address_demangle (&opts, gdbarch, ptr_value, stream, demangle); |
| 653 | } |
| 654 | |
| 655 | if (adjustment) |
| 656 | { |
| 657 | fprintf_filtered (stream, ", this adjustment "); |
| 658 | print_longest (stream, 'd', 1, adjustment); |
| 659 | } |
| 660 | } |
| 661 | |
| 662 | /* GNU v3 implementation of cplus_method_ptr_size. */ |
| 663 | |
| 664 | static int |
| 665 | gnuv3_method_ptr_size (struct type *type) |
| 666 | { |
| 667 | struct gdbarch *gdbarch = get_type_arch (type); |
| 668 | |
| 669 | return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr); |
| 670 | } |
| 671 | |
| 672 | /* GNU v3 implementation of cplus_make_method_ptr. */ |
| 673 | |
| 674 | static void |
| 675 | gnuv3_make_method_ptr (struct type *type, gdb_byte *contents, |
| 676 | CORE_ADDR value, int is_virtual) |
| 677 | { |
| 678 | struct gdbarch *gdbarch = get_type_arch (type); |
| 679 | int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr); |
| 680 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 681 | |
| 682 | /* FIXME drow/2006-12-24: The adjustment of "this" is currently |
| 683 | always zero, since the method pointer is of the correct type. |
| 684 | But if the method pointer came from a base class, this is |
| 685 | incorrect - it should be the offset to the base. The best |
| 686 | fix might be to create the pointer to member pointing at the |
| 687 | base class and cast it to the derived class, but that requires |
| 688 | support for adjusting pointers to members when casting them - |
| 689 | not currently supported by GDB. */ |
| 690 | |
| 691 | if (!gdbarch_vbit_in_delta (gdbarch)) |
| 692 | { |
| 693 | store_unsigned_integer (contents, size, byte_order, value | is_virtual); |
| 694 | store_unsigned_integer (contents + size, size, byte_order, 0); |
| 695 | } |
| 696 | else |
| 697 | { |
| 698 | store_unsigned_integer (contents, size, byte_order, value); |
| 699 | store_unsigned_integer (contents + size, size, byte_order, is_virtual); |
| 700 | } |
| 701 | } |
| 702 | |
| 703 | /* GNU v3 implementation of cplus_method_ptr_to_value. */ |
| 704 | |
| 705 | static struct value * |
| 706 | gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr) |
| 707 | { |
| 708 | struct gdbarch *gdbarch; |
| 709 | const gdb_byte *contents = value_contents (method_ptr); |
| 710 | CORE_ADDR ptr_value; |
| 711 | struct type *self_type, *final_type, *method_type; |
| 712 | LONGEST adjustment; |
| 713 | int vbit; |
| 714 | |
| 715 | self_type = TYPE_SELF_TYPE (check_typedef (value_type (method_ptr))); |
| 716 | final_type = lookup_pointer_type (self_type); |
| 717 | |
| 718 | method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr))); |
| 719 | |
| 720 | /* Extract the pointer to member. */ |
| 721 | gdbarch = get_type_arch (self_type); |
| 722 | vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment); |
| 723 | |
| 724 | /* First convert THIS to match the containing type of the pointer to |
| 725 | member. This cast may adjust the value of THIS. */ |
| 726 | *this_p = value_cast (final_type, *this_p); |
| 727 | |
| 728 | /* Then apply whatever adjustment is necessary. This creates a somewhat |
| 729 | strange pointer: it claims to have type FINAL_TYPE, but in fact it |
| 730 | might not be a valid FINAL_TYPE. For instance, it might be a |
| 731 | base class of FINAL_TYPE. And if it's not the primary base class, |
| 732 | then printing it out as a FINAL_TYPE object would produce some pretty |
| 733 | garbage. |
| 734 | |
| 735 | But we don't really know the type of the first argument in |
| 736 | METHOD_TYPE either, which is why this happens. We can't |
| 737 | dereference this later as a FINAL_TYPE, but once we arrive in the |
| 738 | called method we'll have debugging information for the type of |
| 739 | "this" - and that'll match the value we produce here. |
| 740 | |
| 741 | You can provoke this case by casting a Base::* to a Derived::*, for |
| 742 | instance. */ |
| 743 | *this_p = value_cast (builtin_type (gdbarch)->builtin_data_ptr, *this_p); |
| 744 | *this_p = value_ptradd (*this_p, adjustment); |
| 745 | *this_p = value_cast (final_type, *this_p); |
| 746 | |
| 747 | if (vbit) |
| 748 | { |
| 749 | LONGEST voffset; |
| 750 | |
| 751 | voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch)); |
| 752 | return gnuv3_get_virtual_fn (gdbarch, value_ind (*this_p), |
| 753 | method_type, voffset); |
| 754 | } |
| 755 | else |
| 756 | return value_from_pointer (lookup_pointer_type (method_type), ptr_value); |
| 757 | } |
| 758 | |
| 759 | /* Objects of this type are stored in a hash table and a vector when |
| 760 | printing the vtables for a class. */ |
| 761 | |
| 762 | struct value_and_voffset |
| 763 | { |
| 764 | /* The value representing the object. */ |
| 765 | struct value *value; |
| 766 | |
| 767 | /* The maximum vtable offset we've found for any object at this |
| 768 | offset in the outermost object. */ |
| 769 | int max_voffset; |
| 770 | }; |
| 771 | |
| 772 | /* Hash function for value_and_voffset. */ |
| 773 | |
| 774 | static hashval_t |
| 775 | hash_value_and_voffset (const void *p) |
| 776 | { |
| 777 | const struct value_and_voffset *o = (const struct value_and_voffset *) p; |
| 778 | |
| 779 | return value_address (o->value) + value_embedded_offset (o->value); |
| 780 | } |
| 781 | |
| 782 | /* Equality function for value_and_voffset. */ |
| 783 | |
| 784 | static int |
| 785 | eq_value_and_voffset (const void *a, const void *b) |
| 786 | { |
| 787 | const struct value_and_voffset *ova = (const struct value_and_voffset *) a; |
| 788 | const struct value_and_voffset *ovb = (const struct value_and_voffset *) b; |
| 789 | |
| 790 | return (value_address (ova->value) + value_embedded_offset (ova->value) |
| 791 | == value_address (ovb->value) + value_embedded_offset (ovb->value)); |
| 792 | } |
| 793 | |
| 794 | /* Comparison function for value_and_voffset. */ |
| 795 | |
| 796 | static bool |
| 797 | compare_value_and_voffset (const struct value_and_voffset *va, |
| 798 | const struct value_and_voffset *vb) |
| 799 | { |
| 800 | CORE_ADDR addra = (value_address (va->value) |
| 801 | + value_embedded_offset (va->value)); |
| 802 | CORE_ADDR addrb = (value_address (vb->value) |
| 803 | + value_embedded_offset (vb->value)); |
| 804 | |
| 805 | return addra < addrb; |
| 806 | } |
| 807 | |
| 808 | /* A helper function used when printing vtables. This determines the |
| 809 | key (most derived) sub-object at each address and also computes the |
| 810 | maximum vtable offset seen for the corresponding vtable. Updates |
| 811 | OFFSET_HASH and OFFSET_VEC with a new value_and_voffset object, if |
| 812 | needed. VALUE is the object to examine. */ |
| 813 | |
| 814 | static void |
| 815 | compute_vtable_size (htab_t offset_hash, |
| 816 | std::vector<value_and_voffset *> *offset_vec, |
| 817 | struct value *value) |
| 818 | { |
| 819 | int i; |
| 820 | struct type *type = check_typedef (value_type (value)); |
| 821 | void **slot; |
| 822 | struct value_and_voffset search_vo, *current_vo; |
| 823 | |
| 824 | gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT); |
| 825 | |
| 826 | /* If the object is not dynamic, then we are done; as it cannot have |
| 827 | dynamic base types either. */ |
| 828 | if (!gnuv3_dynamic_class (type)) |
| 829 | return; |
| 830 | |
| 831 | /* Update the hash and the vec, if needed. */ |
| 832 | search_vo.value = value; |
| 833 | slot = htab_find_slot (offset_hash, &search_vo, INSERT); |
| 834 | if (*slot) |
| 835 | current_vo = (struct value_and_voffset *) *slot; |
| 836 | else |
| 837 | { |
| 838 | current_vo = XNEW (struct value_and_voffset); |
| 839 | current_vo->value = value; |
| 840 | current_vo->max_voffset = -1; |
| 841 | *slot = current_vo; |
| 842 | offset_vec->push_back (current_vo); |
| 843 | } |
| 844 | |
| 845 | /* Update the value_and_voffset object with the highest vtable |
| 846 | offset from this class. */ |
| 847 | for (i = 0; i < TYPE_NFN_FIELDS (type); ++i) |
| 848 | { |
| 849 | int j; |
| 850 | struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, i); |
| 851 | |
| 852 | for (j = 0; j < TYPE_FN_FIELDLIST_LENGTH (type, i); ++j) |
| 853 | { |
| 854 | if (TYPE_FN_FIELD_VIRTUAL_P (fn, j)) |
| 855 | { |
| 856 | int voffset = TYPE_FN_FIELD_VOFFSET (fn, j); |
| 857 | |
| 858 | if (voffset > current_vo->max_voffset) |
| 859 | current_vo->max_voffset = voffset; |
| 860 | } |
| 861 | } |
| 862 | } |
| 863 | |
| 864 | /* Recurse into base classes. */ |
| 865 | for (i = 0; i < TYPE_N_BASECLASSES (type); ++i) |
| 866 | compute_vtable_size (offset_hash, offset_vec, value_field (value, i)); |
| 867 | } |
| 868 | |
| 869 | /* Helper for gnuv3_print_vtable that prints a single vtable. */ |
| 870 | |
| 871 | static void |
| 872 | print_one_vtable (struct gdbarch *gdbarch, struct value *value, |
| 873 | int max_voffset, |
| 874 | struct value_print_options *opts) |
| 875 | { |
| 876 | int i; |
| 877 | struct type *type = check_typedef (value_type (value)); |
| 878 | struct value *vtable; |
| 879 | CORE_ADDR vt_addr; |
| 880 | |
| 881 | vtable = gnuv3_get_vtable (gdbarch, type, |
| 882 | value_address (value) |
| 883 | + value_embedded_offset (value)); |
| 884 | vt_addr = value_address (value_field (vtable, |
| 885 | vtable_field_virtual_functions)); |
| 886 | |
| 887 | printf_filtered (_("vtable for '%s' @ %s (subobject @ %s):\n"), |
| 888 | TYPE_SAFE_NAME (type), |
| 889 | paddress (gdbarch, vt_addr), |
| 890 | paddress (gdbarch, (value_address (value) |
| 891 | + value_embedded_offset (value)))); |
| 892 | |
| 893 | for (i = 0; i <= max_voffset; ++i) |
| 894 | { |
| 895 | /* Initialize it just to avoid a GCC false warning. */ |
| 896 | CORE_ADDR addr = 0; |
| 897 | int got_error = 0; |
| 898 | struct value *vfn; |
| 899 | |
| 900 | printf_filtered ("[%d]: ", i); |
| 901 | |
| 902 | vfn = value_subscript (value_field (vtable, |
| 903 | vtable_field_virtual_functions), |
| 904 | i); |
| 905 | |
| 906 | if (gdbarch_vtable_function_descriptors (gdbarch)) |
| 907 | vfn = value_addr (vfn); |
| 908 | |
| 909 | TRY |
| 910 | { |
| 911 | addr = value_as_address (vfn); |
| 912 | } |
| 913 | CATCH (ex, RETURN_MASK_ERROR) |
| 914 | { |
| 915 | printf_filtered (_("<error: %s>"), ex.message); |
| 916 | got_error = 1; |
| 917 | } |
| 918 | END_CATCH |
| 919 | |
| 920 | if (!got_error) |
| 921 | print_function_pointer_address (opts, gdbarch, addr, gdb_stdout); |
| 922 | printf_filtered ("\n"); |
| 923 | } |
| 924 | } |
| 925 | |
| 926 | /* Implementation of the print_vtable method. */ |
| 927 | |
| 928 | static void |
| 929 | gnuv3_print_vtable (struct value *value) |
| 930 | { |
| 931 | struct gdbarch *gdbarch; |
| 932 | struct type *type; |
| 933 | struct value *vtable; |
| 934 | struct value_print_options opts; |
| 935 | int count; |
| 936 | |
| 937 | value = coerce_ref (value); |
| 938 | type = check_typedef (value_type (value)); |
| 939 | if (TYPE_CODE (type) == TYPE_CODE_PTR) |
| 940 | { |
| 941 | value = value_ind (value); |
| 942 | type = check_typedef (value_type (value)); |
| 943 | } |
| 944 | |
| 945 | get_user_print_options (&opts); |
| 946 | |
| 947 | /* Respect 'set print object'. */ |
| 948 | if (opts.objectprint) |
| 949 | { |
| 950 | value = value_full_object (value, NULL, 0, 0, 0); |
| 951 | type = check_typedef (value_type (value)); |
| 952 | } |
| 953 | |
| 954 | gdbarch = get_type_arch (type); |
| 955 | |
| 956 | vtable = NULL; |
| 957 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT) |
| 958 | vtable = gnuv3_get_vtable (gdbarch, type, |
| 959 | value_as_address (value_addr (value))); |
| 960 | |
| 961 | if (!vtable) |
| 962 | { |
| 963 | printf_filtered (_("This object does not have a virtual function table\n")); |
| 964 | return; |
| 965 | } |
| 966 | |
| 967 | htab_up offset_hash (htab_create_alloc (1, hash_value_and_voffset, |
| 968 | eq_value_and_voffset, |
| 969 | xfree, xcalloc, xfree)); |
| 970 | std::vector<value_and_voffset *> result_vec; |
| 971 | |
| 972 | compute_vtable_size (offset_hash.get (), &result_vec, value); |
| 973 | std::sort (result_vec.begin (), result_vec.end (), |
| 974 | compare_value_and_voffset); |
| 975 | |
| 976 | count = 0; |
| 977 | for (value_and_voffset *iter : result_vec) |
| 978 | { |
| 979 | if (iter->max_voffset >= 0) |
| 980 | { |
| 981 | if (count > 0) |
| 982 | printf_filtered ("\n"); |
| 983 | print_one_vtable (gdbarch, iter->value, iter->max_voffset, &opts); |
| 984 | ++count; |
| 985 | } |
| 986 | } |
| 987 | } |
| 988 | |
| 989 | /* Return a GDB type representing `struct std::type_info', laid out |
| 990 | appropriately for ARCH. |
| 991 | |
| 992 | We use this function as the gdbarch per-architecture data |
| 993 | initialization function. */ |
| 994 | |
| 995 | static void * |
| 996 | build_std_type_info_type (struct gdbarch *arch) |
| 997 | { |
| 998 | struct type *t; |
| 999 | struct field *field_list, *field; |
| 1000 | int offset; |
| 1001 | struct type *void_ptr_type |
| 1002 | = builtin_type (arch)->builtin_data_ptr; |
| 1003 | struct type *char_type |
| 1004 | = builtin_type (arch)->builtin_char; |
| 1005 | struct type *char_ptr_type |
| 1006 | = make_pointer_type (make_cv_type (1, 0, char_type, NULL), NULL); |
| 1007 | |
| 1008 | field_list = XCNEWVEC (struct field, 2); |
| 1009 | field = &field_list[0]; |
| 1010 | offset = 0; |
| 1011 | |
| 1012 | /* The vtable. */ |
| 1013 | FIELD_NAME (*field) = "_vptr.type_info"; |
| 1014 | FIELD_TYPE (*field) = void_ptr_type; |
| 1015 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 1016 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 1017 | field++; |
| 1018 | |
| 1019 | /* The name. */ |
| 1020 | FIELD_NAME (*field) = "__name"; |
| 1021 | FIELD_TYPE (*field) = char_ptr_type; |
| 1022 | SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT); |
| 1023 | offset += TYPE_LENGTH (FIELD_TYPE (*field)); |
| 1024 | field++; |
| 1025 | |
| 1026 | gdb_assert (field == (field_list + 2)); |
| 1027 | |
| 1028 | t = arch_type (arch, TYPE_CODE_STRUCT, offset * TARGET_CHAR_BIT, NULL); |
| 1029 | TYPE_NFIELDS (t) = field - field_list; |
| 1030 | TYPE_FIELDS (t) = field_list; |
| 1031 | TYPE_NAME (t) = "gdb_gnu_v3_type_info"; |
| 1032 | INIT_CPLUS_SPECIFIC (t); |
| 1033 | |
| 1034 | return t; |
| 1035 | } |
| 1036 | |
| 1037 | /* Implement the 'get_typeid_type' method. */ |
| 1038 | |
| 1039 | static struct type * |
| 1040 | gnuv3_get_typeid_type (struct gdbarch *gdbarch) |
| 1041 | { |
| 1042 | struct symbol *typeinfo; |
| 1043 | struct type *typeinfo_type; |
| 1044 | |
| 1045 | typeinfo = lookup_symbol ("std::type_info", NULL, STRUCT_DOMAIN, |
| 1046 | NULL).symbol; |
| 1047 | if (typeinfo == NULL) |
| 1048 | typeinfo_type |
| 1049 | = (struct type *) gdbarch_data (gdbarch, std_type_info_gdbarch_data); |
| 1050 | else |
| 1051 | typeinfo_type = SYMBOL_TYPE (typeinfo); |
| 1052 | |
| 1053 | return typeinfo_type; |
| 1054 | } |
| 1055 | |
| 1056 | /* Implement the 'get_typeid' method. */ |
| 1057 | |
| 1058 | static struct value * |
| 1059 | gnuv3_get_typeid (struct value *value) |
| 1060 | { |
| 1061 | struct type *typeinfo_type; |
| 1062 | struct type *type; |
| 1063 | struct gdbarch *gdbarch; |
| 1064 | struct value *result; |
| 1065 | std::string type_name, canonical; |
| 1066 | |
| 1067 | /* We have to handle values a bit trickily here, to allow this code |
| 1068 | to work properly with non_lvalue values that are really just |
| 1069 | disguised types. */ |
| 1070 | if (value_lval_const (value) == lval_memory) |
| 1071 | value = coerce_ref (value); |
| 1072 | |
| 1073 | type = check_typedef (value_type (value)); |
| 1074 | |
| 1075 | /* In the non_lvalue case, a reference might have slipped through |
| 1076 | here. */ |
| 1077 | if (TYPE_CODE (type) == TYPE_CODE_REF) |
| 1078 | type = check_typedef (TYPE_TARGET_TYPE (type)); |
| 1079 | |
| 1080 | /* Ignore top-level cv-qualifiers. */ |
| 1081 | type = make_cv_type (0, 0, type, NULL); |
| 1082 | gdbarch = get_type_arch (type); |
| 1083 | |
| 1084 | type_name = type_to_string (type); |
| 1085 | if (type_name.empty ()) |
| 1086 | error (_("cannot find typeinfo for unnamed type")); |
| 1087 | |
| 1088 | /* We need to canonicalize the type name here, because we do lookups |
| 1089 | using the demangled name, and so we must match the format it |
| 1090 | uses. E.g., GDB tends to use "const char *" as a type name, but |
| 1091 | the demangler uses "char const *". */ |
| 1092 | canonical = cp_canonicalize_string (type_name.c_str ()); |
| 1093 | if (!canonical.empty ()) |
| 1094 | type_name = canonical; |
| 1095 | |
| 1096 | typeinfo_type = gnuv3_get_typeid_type (gdbarch); |
| 1097 | |
| 1098 | /* We check for lval_memory because in the "typeid (type-id)" case, |
| 1099 | the type is passed via a not_lval value object. */ |
| 1100 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 1101 | && value_lval_const (value) == lval_memory |
| 1102 | && gnuv3_dynamic_class (type)) |
| 1103 | { |
| 1104 | struct value *vtable, *typeinfo_value; |
| 1105 | CORE_ADDR address = value_address (value) + value_embedded_offset (value); |
| 1106 | |
| 1107 | vtable = gnuv3_get_vtable (gdbarch, type, address); |
| 1108 | if (vtable == NULL) |
| 1109 | error (_("cannot find typeinfo for object of type '%s'"), |
| 1110 | type_name.c_str ()); |
| 1111 | typeinfo_value = value_field (vtable, vtable_field_type_info); |
| 1112 | result = value_ind (value_cast (make_pointer_type (typeinfo_type, NULL), |
| 1113 | typeinfo_value)); |
| 1114 | } |
| 1115 | else |
| 1116 | { |
| 1117 | std::string sym_name = std::string ("typeinfo for ") + type_name; |
| 1118 | bound_minimal_symbol minsym |
| 1119 | = lookup_minimal_symbol (sym_name.c_str (), NULL, NULL); |
| 1120 | |
| 1121 | if (minsym.minsym == NULL) |
| 1122 | error (_("could not find typeinfo symbol for '%s'"), type_name.c_str ()); |
| 1123 | |
| 1124 | result = value_at_lazy (typeinfo_type, BMSYMBOL_VALUE_ADDRESS (minsym)); |
| 1125 | } |
| 1126 | |
| 1127 | return result; |
| 1128 | } |
| 1129 | |
| 1130 | /* Implement the 'get_typename_from_type_info' method. */ |
| 1131 | |
| 1132 | static std::string |
| 1133 | gnuv3_get_typename_from_type_info (struct value *type_info_ptr) |
| 1134 | { |
| 1135 | struct gdbarch *gdbarch = get_type_arch (value_type (type_info_ptr)); |
| 1136 | struct bound_minimal_symbol typeinfo_sym; |
| 1137 | CORE_ADDR addr; |
| 1138 | const char *symname; |
| 1139 | const char *class_name; |
| 1140 | const char *atsign; |
| 1141 | |
| 1142 | addr = value_as_address (type_info_ptr); |
| 1143 | typeinfo_sym = lookup_minimal_symbol_by_pc (addr); |
| 1144 | if (typeinfo_sym.minsym == NULL) |
| 1145 | error (_("could not find minimal symbol for typeinfo address %s"), |
| 1146 | paddress (gdbarch, addr)); |
| 1147 | |
| 1148 | #define TYPEINFO_PREFIX "typeinfo for " |
| 1149 | #define TYPEINFO_PREFIX_LEN (sizeof (TYPEINFO_PREFIX) - 1) |
| 1150 | symname = MSYMBOL_DEMANGLED_NAME (typeinfo_sym.minsym); |
| 1151 | if (symname == NULL || strncmp (symname, TYPEINFO_PREFIX, |
| 1152 | TYPEINFO_PREFIX_LEN)) |
| 1153 | error (_("typeinfo symbol '%s' has unexpected name"), |
| 1154 | MSYMBOL_LINKAGE_NAME (typeinfo_sym.minsym)); |
| 1155 | class_name = symname + TYPEINFO_PREFIX_LEN; |
| 1156 | |
| 1157 | /* Strip off @plt and version suffixes. */ |
| 1158 | atsign = strchr (class_name, '@'); |
| 1159 | if (atsign != NULL) |
| 1160 | return std::string (class_name, atsign - class_name); |
| 1161 | return class_name; |
| 1162 | } |
| 1163 | |
| 1164 | /* Implement the 'get_type_from_type_info' method. */ |
| 1165 | |
| 1166 | static struct type * |
| 1167 | gnuv3_get_type_from_type_info (struct value *type_info_ptr) |
| 1168 | { |
| 1169 | /* We have to parse the type name, since in general there is not a |
| 1170 | symbol for a type. This is somewhat bogus since there may be a |
| 1171 | mis-parse. Another approach might be to re-use the demangler's |
| 1172 | internal form to reconstruct the type somehow. */ |
| 1173 | std::string type_name = gnuv3_get_typename_from_type_info (type_info_ptr); |
| 1174 | expression_up expr (parse_expression (type_name.c_str ())); |
| 1175 | struct value *type_val = evaluate_type (expr.get ()); |
| 1176 | return value_type (type_val); |
| 1177 | } |
| 1178 | |
| 1179 | /* Determine if we are currently in a C++ thunk. If so, get the address |
| 1180 | of the routine we are thunking to and continue to there instead. */ |
| 1181 | |
| 1182 | static CORE_ADDR |
| 1183 | gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc) |
| 1184 | { |
| 1185 | CORE_ADDR real_stop_pc, method_stop_pc, func_addr; |
| 1186 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1187 | struct bound_minimal_symbol thunk_sym, fn_sym; |
| 1188 | struct obj_section *section; |
| 1189 | const char *thunk_name, *fn_name; |
| 1190 | |
| 1191 | real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); |
| 1192 | if (real_stop_pc == 0) |
| 1193 | real_stop_pc = stop_pc; |
| 1194 | |
| 1195 | /* Find the linker symbol for this potential thunk. */ |
| 1196 | thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc); |
| 1197 | section = find_pc_section (real_stop_pc); |
| 1198 | if (thunk_sym.minsym == NULL || section == NULL) |
| 1199 | return 0; |
| 1200 | |
| 1201 | /* The symbol's demangled name should be something like "virtual |
| 1202 | thunk to FUNCTION", where FUNCTION is the name of the function |
| 1203 | being thunked to. */ |
| 1204 | thunk_name = MSYMBOL_DEMANGLED_NAME (thunk_sym.minsym); |
| 1205 | if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL) |
| 1206 | return 0; |
| 1207 | |
| 1208 | fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to "); |
| 1209 | fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile); |
| 1210 | if (fn_sym.minsym == NULL) |
| 1211 | return 0; |
| 1212 | |
| 1213 | method_stop_pc = BMSYMBOL_VALUE_ADDRESS (fn_sym); |
| 1214 | |
| 1215 | /* Some targets have minimal symbols pointing to function descriptors |
| 1216 | (powerpc 64 for example). Make sure to retrieve the address |
| 1217 | of the real function from the function descriptor before passing on |
| 1218 | the address to other layers of GDB. */ |
| 1219 | func_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, method_stop_pc, |
| 1220 | current_top_target ()); |
| 1221 | if (func_addr != 0) |
| 1222 | method_stop_pc = func_addr; |
| 1223 | |
| 1224 | real_stop_pc = gdbarch_skip_trampoline_code |
| 1225 | (gdbarch, frame, method_stop_pc); |
| 1226 | if (real_stop_pc == 0) |
| 1227 | real_stop_pc = method_stop_pc; |
| 1228 | |
| 1229 | return real_stop_pc; |
| 1230 | } |
| 1231 | |
| 1232 | /* Return nonzero if a type should be passed by reference. |
| 1233 | |
| 1234 | The rule in the v3 ABI document comes from section 3.1.1. If the |
| 1235 | type has a non-trivial copy constructor or destructor, then the |
| 1236 | caller must make a copy (by calling the copy constructor if there |
| 1237 | is one or perform the copy itself otherwise), pass the address of |
| 1238 | the copy, and then destroy the temporary (if necessary). |
| 1239 | |
| 1240 | For return values with non-trivial copy constructors or |
| 1241 | destructors, space will be allocated in the caller, and a pointer |
| 1242 | will be passed as the first argument (preceding "this"). |
| 1243 | |
| 1244 | We don't have a bulletproof mechanism for determining whether a |
| 1245 | constructor or destructor is trivial. For GCC and DWARF2 debug |
| 1246 | information, we can check the artificial flag. |
| 1247 | |
| 1248 | We don't do anything with the constructors or destructors, |
| 1249 | but we have to get the argument passing right anyway. */ |
| 1250 | static int |
| 1251 | gnuv3_pass_by_reference (struct type *type) |
| 1252 | { |
| 1253 | int fieldnum, fieldelem; |
| 1254 | |
| 1255 | type = check_typedef (type); |
| 1256 | |
| 1257 | /* We're only interested in things that can have methods. */ |
| 1258 | if (TYPE_CODE (type) != TYPE_CODE_STRUCT |
| 1259 | && TYPE_CODE (type) != TYPE_CODE_UNION) |
| 1260 | return 0; |
| 1261 | |
| 1262 | /* A dynamic class has a non-trivial copy constructor. |
| 1263 | See c++98 section 12.8 Copying class objects [class.copy]. */ |
| 1264 | if (gnuv3_dynamic_class (type)) |
| 1265 | return 1; |
| 1266 | |
| 1267 | for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++) |
| 1268 | for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum); |
| 1269 | fieldelem++) |
| 1270 | { |
| 1271 | struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum); |
| 1272 | const char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum); |
| 1273 | struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem); |
| 1274 | |
| 1275 | /* If this function is marked as artificial, it is compiler-generated, |
| 1276 | and we assume it is trivial. */ |
| 1277 | if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem)) |
| 1278 | continue; |
| 1279 | |
| 1280 | /* If we've found a destructor, we must pass this by reference. */ |
| 1281 | if (name[0] == '~') |
| 1282 | return 1; |
| 1283 | |
| 1284 | /* If the mangled name of this method doesn't indicate that it |
| 1285 | is a constructor, we're not interested. |
| 1286 | |
| 1287 | FIXME drow/2007-09-23: We could do this using the name of |
| 1288 | the method and the name of the class instead of dealing |
| 1289 | with the mangled name. We don't have a convenient function |
| 1290 | to strip off both leading scope qualifiers and trailing |
| 1291 | template arguments yet. */ |
| 1292 | if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem)) |
| 1293 | && !TYPE_FN_FIELD_CONSTRUCTOR (fn, fieldelem)) |
| 1294 | continue; |
| 1295 | |
| 1296 | /* If this method takes two arguments, and the second argument is |
| 1297 | a reference to this class, then it is a copy constructor. */ |
| 1298 | if (TYPE_NFIELDS (fieldtype) == 2) |
| 1299 | { |
| 1300 | struct type *arg_type = TYPE_FIELD_TYPE (fieldtype, 1); |
| 1301 | |
| 1302 | if (TYPE_CODE (arg_type) == TYPE_CODE_REF) |
| 1303 | { |
| 1304 | struct type *arg_target_type; |
| 1305 | |
| 1306 | arg_target_type = check_typedef (TYPE_TARGET_TYPE (arg_type)); |
| 1307 | if (class_types_same_p (arg_target_type, type)) |
| 1308 | return 1; |
| 1309 | } |
| 1310 | } |
| 1311 | } |
| 1312 | |
| 1313 | /* Even if all the constructors and destructors were artificial, one |
| 1314 | of them may have invoked a non-artificial constructor or |
| 1315 | destructor in a base class. If any base class needs to be passed |
| 1316 | by reference, so does this class. Similarly for members, which |
| 1317 | are constructed whenever this class is. We do not need to worry |
| 1318 | about recursive loops here, since we are only looking at members |
| 1319 | of complete class type. Also ignore any static members. */ |
| 1320 | for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++) |
| 1321 | if (! field_is_static (&TYPE_FIELD (type, fieldnum)) |
| 1322 | && gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum))) |
| 1323 | return 1; |
| 1324 | |
| 1325 | return 0; |
| 1326 | } |
| 1327 | |
| 1328 | static void |
| 1329 | init_gnuv3_ops (void) |
| 1330 | { |
| 1331 | vtable_type_gdbarch_data |
| 1332 | = gdbarch_data_register_post_init (build_gdb_vtable_type); |
| 1333 | std_type_info_gdbarch_data |
| 1334 | = gdbarch_data_register_post_init (build_std_type_info_type); |
| 1335 | |
| 1336 | gnu_v3_abi_ops.shortname = "gnu-v3"; |
| 1337 | gnu_v3_abi_ops.longname = "GNU G++ Version 3 ABI"; |
| 1338 | gnu_v3_abi_ops.doc = "G++ Version 3 ABI"; |
| 1339 | gnu_v3_abi_ops.is_destructor_name = |
| 1340 | (enum dtor_kinds (*) (const char *))is_gnu_v3_mangled_dtor; |
| 1341 | gnu_v3_abi_ops.is_constructor_name = |
| 1342 | (enum ctor_kinds (*) (const char *))is_gnu_v3_mangled_ctor; |
| 1343 | gnu_v3_abi_ops.is_vtable_name = gnuv3_is_vtable_name; |
| 1344 | gnu_v3_abi_ops.is_operator_name = gnuv3_is_operator_name; |
| 1345 | gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type; |
| 1346 | gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field; |
| 1347 | gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset; |
| 1348 | gnu_v3_abi_ops.print_method_ptr = gnuv3_print_method_ptr; |
| 1349 | gnu_v3_abi_ops.method_ptr_size = gnuv3_method_ptr_size; |
| 1350 | gnu_v3_abi_ops.make_method_ptr = gnuv3_make_method_ptr; |
| 1351 | gnu_v3_abi_ops.method_ptr_to_value = gnuv3_method_ptr_to_value; |
| 1352 | gnu_v3_abi_ops.print_vtable = gnuv3_print_vtable; |
| 1353 | gnu_v3_abi_ops.get_typeid = gnuv3_get_typeid; |
| 1354 | gnu_v3_abi_ops.get_typeid_type = gnuv3_get_typeid_type; |
| 1355 | gnu_v3_abi_ops.get_type_from_type_info = gnuv3_get_type_from_type_info; |
| 1356 | gnu_v3_abi_ops.get_typename_from_type_info |
| 1357 | = gnuv3_get_typename_from_type_info; |
| 1358 | gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline; |
| 1359 | gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference; |
| 1360 | } |
| 1361 | |
| 1362 | void |
| 1363 | _initialize_gnu_v3_abi (void) |
| 1364 | { |
| 1365 | init_gnuv3_ops (); |
| 1366 | |
| 1367 | register_cp_abi (&gnu_v3_abi_ops); |
| 1368 | set_cp_abi_as_auto_default (gnu_v3_abi_ops.shortname); |
| 1369 | } |