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1 /* Abstraction of GNU v3 abi.
2 Contributed by Jim Blandy <jimb@redhat.com>
3
4 Copyright (C) 2001-2017 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
31 static struct cp_abi_ops gnu_v3_abi_ops;
32
33 /* A gdbarch key for std::type_info, in the event that it can't be
34 found in the debug info. */
35
36 static struct gdbarch_data *std_type_info_gdbarch_data;
37
38
39 static int
40 gnuv3_is_vtable_name (const char *name)
41 {
42 return startswith (name, "_ZTV");
43 }
44
45 static int
46 gnuv3_is_operator_name (const char *name)
47 {
48 return startswith (name, "operator");
49 }
50
51
52 /* To help us find the components of a vtable, we build ourselves a
53 GDB type object representing the vtable structure. Following the
54 V3 ABI, it goes something like this:
55
56 struct gdb_gnu_v3_abi_vtable {
57
58 / * An array of virtual call and virtual base offsets. The real
59 length of this array depends on the class hierarchy; we use
60 negative subscripts to access the elements. Yucky, but
61 better than the alternatives. * /
62 ptrdiff_t vcall_and_vbase_offsets[0];
63
64 / * The offset from a virtual pointer referring to this table
65 to the top of the complete object. * /
66 ptrdiff_t offset_to_top;
67
68 / * The type_info pointer for this class. This is really a
69 std::type_info *, but GDB doesn't really look at the
70 type_info object itself, so we don't bother to get the type
71 exactly right. * /
72 void *type_info;
73
74 / * Virtual table pointers in objects point here. * /
75
76 / * Virtual function pointers. Like the vcall/vbase array, the
77 real length of this table depends on the class hierarchy. * /
78 void (*virtual_functions[0]) ();
79
80 };
81
82 The catch, of course, is that the exact layout of this table
83 depends on the ABI --- word size, endianness, alignment, etc. So
84 the GDB type object is actually a per-architecture kind of thing.
85
86 vtable_type_gdbarch_data is a gdbarch per-architecture data pointer
87 which refers to the struct type * for this structure, laid out
88 appropriately for the architecture. */
89 static struct gdbarch_data *vtable_type_gdbarch_data;
90
91
92 /* Human-readable names for the numbers of the fields above. */
93 enum {
94 vtable_field_vcall_and_vbase_offsets,
95 vtable_field_offset_to_top,
96 vtable_field_type_info,
97 vtable_field_virtual_functions
98 };
99
100
101 /* Return a GDB type representing `struct gdb_gnu_v3_abi_vtable',
102 described above, laid out appropriately for ARCH.
103
104 We use this function as the gdbarch per-architecture data
105 initialization function. */
106 static void *
107 build_gdb_vtable_type (struct gdbarch *arch)
108 {
109 struct type *t;
110 struct field *field_list, *field;
111 int offset;
112
113 struct type *void_ptr_type
114 = builtin_type (arch)->builtin_data_ptr;
115 struct type *ptr_to_void_fn_type
116 = builtin_type (arch)->builtin_func_ptr;
117
118 /* ARCH can't give us the true ptrdiff_t type, so we guess. */
119 struct type *ptrdiff_type
120 = arch_integer_type (arch, gdbarch_ptr_bit (arch), 0, "ptrdiff_t");
121
122 /* We assume no padding is necessary, since GDB doesn't know
123 anything about alignment at the moment. If this assumption bites
124 us, we should add a gdbarch method which, given a type, returns
125 the alignment that type requires, and then use that here. */
126
127 /* Build the field list. */
128 field_list = XCNEWVEC (struct field, 4);
129 field = &field_list[0];
130 offset = 0;
131
132 /* ptrdiff_t vcall_and_vbase_offsets[0]; */
133 FIELD_NAME (*field) = "vcall_and_vbase_offsets";
134 FIELD_TYPE (*field) = lookup_array_range_type (ptrdiff_type, 0, -1);
135 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
136 offset += TYPE_LENGTH (FIELD_TYPE (*field));
137 field++;
138
139 /* ptrdiff_t offset_to_top; */
140 FIELD_NAME (*field) = "offset_to_top";
141 FIELD_TYPE (*field) = ptrdiff_type;
142 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
143 offset += TYPE_LENGTH (FIELD_TYPE (*field));
144 field++;
145
146 /* void *type_info; */
147 FIELD_NAME (*field) = "type_info";
148 FIELD_TYPE (*field) = void_ptr_type;
149 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
150 offset += TYPE_LENGTH (FIELD_TYPE (*field));
151 field++;
152
153 /* void (*virtual_functions[0]) (); */
154 FIELD_NAME (*field) = "virtual_functions";
155 FIELD_TYPE (*field) = lookup_array_range_type (ptr_to_void_fn_type, 0, -1);
156 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
157 offset += TYPE_LENGTH (FIELD_TYPE (*field));
158 field++;
159
160 /* We assumed in the allocation above that there were four fields. */
161 gdb_assert (field == (field_list + 4));
162
163 t = arch_type (arch, TYPE_CODE_STRUCT, offset, NULL);
164 TYPE_NFIELDS (t) = field - field_list;
165 TYPE_FIELDS (t) = field_list;
166 TYPE_TAG_NAME (t) = "gdb_gnu_v3_abi_vtable";
167 INIT_CPLUS_SPECIFIC (t);
168
169 return make_type_with_address_space (t, TYPE_INSTANCE_FLAG_CODE_SPACE);
170 }
171
172
173 /* Return the ptrdiff_t type used in the vtable type. */
174 static struct type *
175 vtable_ptrdiff_type (struct gdbarch *gdbarch)
176 {
177 struct type *vtable_type
178 = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data);
179
180 /* The "offset_to_top" field has the appropriate (ptrdiff_t) type. */
181 return TYPE_FIELD_TYPE (vtable_type, vtable_field_offset_to_top);
182 }
183
184 /* Return the offset from the start of the imaginary `struct
185 gdb_gnu_v3_abi_vtable' object to the vtable's "address point"
186 (i.e., where objects' virtual table pointers point). */
187 static int
188 vtable_address_point_offset (struct gdbarch *gdbarch)
189 {
190 struct type *vtable_type
191 = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data);
192
193 return (TYPE_FIELD_BITPOS (vtable_type, vtable_field_virtual_functions)
194 / TARGET_CHAR_BIT);
195 }
196
197
198 /* Determine whether structure TYPE is a dynamic class. Cache the
199 result. */
200
201 static int
202 gnuv3_dynamic_class (struct type *type)
203 {
204 int fieldnum, fieldelem;
205
206 type = check_typedef (type);
207 gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT
208 || TYPE_CODE (type) == TYPE_CODE_UNION);
209
210 if (TYPE_CODE (type) == TYPE_CODE_UNION)
211 return 0;
212
213 if (TYPE_CPLUS_DYNAMIC (type))
214 return TYPE_CPLUS_DYNAMIC (type) == 1;
215
216 ALLOCATE_CPLUS_STRUCT_TYPE (type);
217
218 for (fieldnum = 0; fieldnum < TYPE_N_BASECLASSES (type); fieldnum++)
219 if (BASETYPE_VIA_VIRTUAL (type, fieldnum)
220 || gnuv3_dynamic_class (TYPE_FIELD_TYPE (type, fieldnum)))
221 {
222 TYPE_CPLUS_DYNAMIC (type) = 1;
223 return 1;
224 }
225
226 for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
227 for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
228 fieldelem++)
229 {
230 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, fieldnum);
231
232 if (TYPE_FN_FIELD_VIRTUAL_P (f, fieldelem))
233 {
234 TYPE_CPLUS_DYNAMIC (type) = 1;
235 return 1;
236 }
237 }
238
239 TYPE_CPLUS_DYNAMIC (type) = -1;
240 return 0;
241 }
242
243 /* Find the vtable for a value of CONTAINER_TYPE located at
244 CONTAINER_ADDR. Return a value of the correct vtable type for this
245 architecture, or NULL if CONTAINER does not have a vtable. */
246
247 static struct value *
248 gnuv3_get_vtable (struct gdbarch *gdbarch,
249 struct type *container_type, CORE_ADDR container_addr)
250 {
251 struct type *vtable_type
252 = (struct type *) gdbarch_data (gdbarch, vtable_type_gdbarch_data);
253 struct type *vtable_pointer_type;
254 struct value *vtable_pointer;
255 CORE_ADDR vtable_address;
256
257 container_type = check_typedef (container_type);
258 gdb_assert (TYPE_CODE (container_type) == TYPE_CODE_STRUCT);
259
260 /* If this type does not have a virtual table, don't read the first
261 field. */
262 if (!gnuv3_dynamic_class (container_type))
263 return NULL;
264
265 /* We do not consult the debug information to find the virtual table.
266 The ABI specifies that it is always at offset zero in any class,
267 and debug information may not represent it.
268
269 We avoid using value_contents on principle, because the object might
270 be large. */
271
272 /* Find the type "pointer to virtual table". */
273 vtable_pointer_type = lookup_pointer_type (vtable_type);
274
275 /* Load it from the start of the class. */
276 vtable_pointer = value_at (vtable_pointer_type, container_addr);
277 vtable_address = value_as_address (vtable_pointer);
278
279 /* Correct it to point at the start of the virtual table, rather
280 than the address point. */
281 return value_at_lazy (vtable_type,
282 vtable_address
283 - vtable_address_point_offset (gdbarch));
284 }
285
286
287 static struct type *
288 gnuv3_rtti_type (struct value *value,
289 int *full_p, LONGEST *top_p, int *using_enc_p)
290 {
291 struct gdbarch *gdbarch;
292 struct type *values_type = check_typedef (value_type (value));
293 struct value *vtable;
294 struct minimal_symbol *vtable_symbol;
295 const char *vtable_symbol_name;
296 const char *class_name;
297 struct type *run_time_type;
298 LONGEST offset_to_top;
299 const char *atsign;
300
301 /* We only have RTTI for class objects. */
302 if (TYPE_CODE (values_type) != TYPE_CODE_STRUCT)
303 return NULL;
304
305 /* Determine architecture. */
306 gdbarch = get_type_arch (values_type);
307
308 if (using_enc_p)
309 *using_enc_p = 0;
310
311 vtable = gnuv3_get_vtable (gdbarch, values_type,
312 value_as_address (value_addr (value)));
313 if (vtable == NULL)
314 return NULL;
315
316 /* Find the linker symbol for this vtable. */
317 vtable_symbol
318 = lookup_minimal_symbol_by_pc (value_address (vtable)
319 + value_embedded_offset (vtable)).minsym;
320 if (! vtable_symbol)
321 return NULL;
322
323 /* The symbol's demangled name should be something like "vtable for
324 CLASS", where CLASS is the name of the run-time type of VALUE.
325 If we didn't like this approach, we could instead look in the
326 type_info object itself to get the class name. But this way
327 should work just as well, and doesn't read target memory. */
328 vtable_symbol_name = MSYMBOL_DEMANGLED_NAME (vtable_symbol);
329 if (vtable_symbol_name == NULL
330 || !startswith (vtable_symbol_name, "vtable for "))
331 {
332 warning (_("can't find linker symbol for virtual table for `%s' value"),
333 TYPE_SAFE_NAME (values_type));
334 if (vtable_symbol_name)
335 warning (_(" found `%s' instead"), vtable_symbol_name);
336 return NULL;
337 }
338 class_name = vtable_symbol_name + 11;
339
340 /* Strip off @plt and version suffixes. */
341 atsign = strchr (class_name, '@');
342 if (atsign != NULL)
343 {
344 char *copy;
345
346 copy = (char *) alloca (atsign - class_name + 1);
347 memcpy (copy, class_name, atsign - class_name);
348 copy[atsign - class_name] = '\0';
349 class_name = copy;
350 }
351
352 /* Try to look up the class name as a type name. */
353 /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */
354 run_time_type = cp_lookup_rtti_type (class_name, NULL);
355 if (run_time_type == NULL)
356 return NULL;
357
358 /* Get the offset from VALUE to the top of the complete object.
359 NOTE: this is the reverse of the meaning of *TOP_P. */
360 offset_to_top
361 = value_as_long (value_field (vtable, vtable_field_offset_to_top));
362
363 if (full_p)
364 *full_p = (- offset_to_top == value_embedded_offset (value)
365 && (TYPE_LENGTH (value_enclosing_type (value))
366 >= TYPE_LENGTH (run_time_type)));
367 if (top_p)
368 *top_p = - offset_to_top;
369 return run_time_type;
370 }
371
372 /* Return a function pointer for CONTAINER's VTABLE_INDEX'th virtual
373 function, of type FNTYPE. */
374
375 static struct value *
376 gnuv3_get_virtual_fn (struct gdbarch *gdbarch, struct value *container,
377 struct type *fntype, int vtable_index)
378 {
379 struct value *vtable, *vfn;
380
381 /* Every class with virtual functions must have a vtable. */
382 vtable = gnuv3_get_vtable (gdbarch, value_type (container),
383 value_as_address (value_addr (container)));
384 gdb_assert (vtable != NULL);
385
386 /* Fetch the appropriate function pointer from the vtable. */
387 vfn = value_subscript (value_field (vtable, vtable_field_virtual_functions),
388 vtable_index);
389
390 /* If this architecture uses function descriptors directly in the vtable,
391 then the address of the vtable entry is actually a "function pointer"
392 (i.e. points to the descriptor). We don't need to scale the index
393 by the size of a function descriptor; GCC does that before outputing
394 debug information. */
395 if (gdbarch_vtable_function_descriptors (gdbarch))
396 vfn = value_addr (vfn);
397
398 /* Cast the function pointer to the appropriate type. */
399 vfn = value_cast (lookup_pointer_type (fntype), vfn);
400
401 return vfn;
402 }
403
404 /* GNU v3 implementation of value_virtual_fn_field. See cp-abi.h
405 for a description of the arguments. */
406
407 static struct value *
408 gnuv3_virtual_fn_field (struct value **value_p,
409 struct fn_field *f, int j,
410 struct type *vfn_base, int offset)
411 {
412 struct type *values_type = check_typedef (value_type (*value_p));
413 struct gdbarch *gdbarch;
414
415 /* Some simple sanity checks. */
416 if (TYPE_CODE (values_type) != TYPE_CODE_STRUCT)
417 error (_("Only classes can have virtual functions."));
418
419 /* Determine architecture. */
420 gdbarch = get_type_arch (values_type);
421
422 /* Cast our value to the base class which defines this virtual
423 function. This takes care of any necessary `this'
424 adjustments. */
425 if (vfn_base != values_type)
426 *value_p = value_cast (vfn_base, *value_p);
427
428 return gnuv3_get_virtual_fn (gdbarch, *value_p, TYPE_FN_FIELD_TYPE (f, j),
429 TYPE_FN_FIELD_VOFFSET (f, j));
430 }
431
432 /* Compute the offset of the baseclass which is
433 the INDEXth baseclass of class TYPE,
434 for value at VALADDR (in host) at ADDRESS (in target).
435 The result is the offset of the baseclass value relative
436 to (the address of)(ARG) + OFFSET.
437
438 -1 is returned on error. */
439
440 static int
441 gnuv3_baseclass_offset (struct type *type, int index,
442 const bfd_byte *valaddr, LONGEST embedded_offset,
443 CORE_ADDR address, const struct value *val)
444 {
445 struct gdbarch *gdbarch;
446 struct type *ptr_type;
447 struct value *vtable;
448 struct value *vbase_array;
449 long int cur_base_offset, base_offset;
450
451 /* Determine architecture. */
452 gdbarch = get_type_arch (type);
453 ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
454
455 /* If it isn't a virtual base, this is easy. The offset is in the
456 type definition. */
457 if (!BASETYPE_VIA_VIRTUAL (type, index))
458 return TYPE_BASECLASS_BITPOS (type, index) / 8;
459
460 /* To access a virtual base, we need to use the vbase offset stored in
461 our vtable. Recent GCC versions provide this information. If it isn't
462 available, we could get what we needed from RTTI, or from drawing the
463 complete inheritance graph based on the debug info. Neither is
464 worthwhile. */
465 cur_base_offset = TYPE_BASECLASS_BITPOS (type, index) / 8;
466 if (cur_base_offset >= - vtable_address_point_offset (gdbarch))
467 error (_("Expected a negative vbase offset (old compiler?)"));
468
469 cur_base_offset = cur_base_offset + vtable_address_point_offset (gdbarch);
470 if ((- cur_base_offset) % TYPE_LENGTH (ptr_type) != 0)
471 error (_("Misaligned vbase offset."));
472 cur_base_offset = cur_base_offset / ((int) TYPE_LENGTH (ptr_type));
473
474 vtable = gnuv3_get_vtable (gdbarch, type, address + embedded_offset);
475 gdb_assert (vtable != NULL);
476 vbase_array = value_field (vtable, vtable_field_vcall_and_vbase_offsets);
477 base_offset = value_as_long (value_subscript (vbase_array, cur_base_offset));
478 return base_offset;
479 }
480
481 /* Locate a virtual method in DOMAIN or its non-virtual base classes
482 which has virtual table index VOFFSET. The method has an associated
483 "this" adjustment of ADJUSTMENT bytes. */
484
485 static const char *
486 gnuv3_find_method_in (struct type *domain, CORE_ADDR voffset,
487 LONGEST adjustment)
488 {
489 int i;
490
491 /* Search this class first. */
492 if (adjustment == 0)
493 {
494 int len;
495
496 len = TYPE_NFN_FIELDS (domain);
497 for (i = 0; i < len; i++)
498 {
499 int len2, j;
500 struct fn_field *f;
501
502 f = TYPE_FN_FIELDLIST1 (domain, i);
503 len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);
504
505 check_stub_method_group (domain, i);
506 for (j = 0; j < len2; j++)
507 if (TYPE_FN_FIELD_VOFFSET (f, j) == voffset)
508 return TYPE_FN_FIELD_PHYSNAME (f, j);
509 }
510 }
511
512 /* Next search non-virtual bases. If it's in a virtual base,
513 we're out of luck. */
514 for (i = 0; i < TYPE_N_BASECLASSES (domain); i++)
515 {
516 int pos;
517 struct type *basetype;
518
519 if (BASETYPE_VIA_VIRTUAL (domain, i))
520 continue;
521
522 pos = TYPE_BASECLASS_BITPOS (domain, i) / 8;
523 basetype = TYPE_FIELD_TYPE (domain, i);
524 /* Recurse with a modified adjustment. We don't need to adjust
525 voffset. */
526 if (adjustment >= pos && adjustment < pos + TYPE_LENGTH (basetype))
527 return gnuv3_find_method_in (basetype, voffset, adjustment - pos);
528 }
529
530 return NULL;
531 }
532
533 /* Decode GNU v3 method pointer. */
534
535 static int
536 gnuv3_decode_method_ptr (struct gdbarch *gdbarch,
537 const gdb_byte *contents,
538 CORE_ADDR *value_p,
539 LONGEST *adjustment_p)
540 {
541 struct type *funcptr_type = builtin_type (gdbarch)->builtin_func_ptr;
542 struct type *offset_type = vtable_ptrdiff_type (gdbarch);
543 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
544 CORE_ADDR ptr_value;
545 LONGEST voffset, adjustment;
546 int vbit;
547
548 /* Extract the pointer to member. The first element is either a pointer
549 or a vtable offset. For pointers, we need to use extract_typed_address
550 to allow the back-end to convert the pointer to a GDB address -- but
551 vtable offsets we must handle as integers. At this point, we do not
552 yet know which case we have, so we extract the value under both
553 interpretations and choose the right one later on. */
554 ptr_value = extract_typed_address (contents, funcptr_type);
555 voffset = extract_signed_integer (contents,
556 TYPE_LENGTH (funcptr_type), byte_order);
557 contents += TYPE_LENGTH (funcptr_type);
558 adjustment = extract_signed_integer (contents,
559 TYPE_LENGTH (offset_type), byte_order);
560
561 if (!gdbarch_vbit_in_delta (gdbarch))
562 {
563 vbit = voffset & 1;
564 voffset = voffset ^ vbit;
565 }
566 else
567 {
568 vbit = adjustment & 1;
569 adjustment = adjustment >> 1;
570 }
571
572 *value_p = vbit? voffset : ptr_value;
573 *adjustment_p = adjustment;
574 return vbit;
575 }
576
577 /* GNU v3 implementation of cplus_print_method_ptr. */
578
579 static void
580 gnuv3_print_method_ptr (const gdb_byte *contents,
581 struct type *type,
582 struct ui_file *stream)
583 {
584 struct type *self_type = TYPE_SELF_TYPE (type);
585 struct gdbarch *gdbarch = get_type_arch (self_type);
586 CORE_ADDR ptr_value;
587 LONGEST adjustment;
588 int vbit;
589
590 /* Extract the pointer to member. */
591 vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
592
593 /* Check for NULL. */
594 if (ptr_value == 0 && vbit == 0)
595 {
596 fprintf_filtered (stream, "NULL");
597 return;
598 }
599
600 /* Search for a virtual method. */
601 if (vbit)
602 {
603 CORE_ADDR voffset;
604 const char *physname;
605
606 /* It's a virtual table offset, maybe in this class. Search
607 for a field with the correct vtable offset. First convert it
608 to an index, as used in TYPE_FN_FIELD_VOFFSET. */
609 voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
610
611 physname = gnuv3_find_method_in (self_type, voffset, adjustment);
612
613 /* If we found a method, print that. We don't bother to disambiguate
614 possible paths to the method based on the adjustment. */
615 if (physname)
616 {
617 char *demangled_name = gdb_demangle (physname,
618 DMGL_ANSI | DMGL_PARAMS);
619
620 fprintf_filtered (stream, "&virtual ");
621 if (demangled_name == NULL)
622 fputs_filtered (physname, stream);
623 else
624 {
625 fputs_filtered (demangled_name, stream);
626 xfree (demangled_name);
627 }
628 return;
629 }
630 }
631 else if (ptr_value != 0)
632 {
633 /* Found a non-virtual function: print out the type. */
634 fputs_filtered ("(", stream);
635 c_print_type (type, "", stream, -1, 0, &type_print_raw_options);
636 fputs_filtered (") ", stream);
637 }
638
639 /* We didn't find it; print the raw data. */
640 if (vbit)
641 {
642 fprintf_filtered (stream, "&virtual table offset ");
643 print_longest (stream, 'd', 1, ptr_value);
644 }
645 else
646 {
647 struct value_print_options opts;
648
649 get_user_print_options (&opts);
650 print_address_demangle (&opts, gdbarch, ptr_value, stream, demangle);
651 }
652
653 if (adjustment)
654 {
655 fprintf_filtered (stream, ", this adjustment ");
656 print_longest (stream, 'd', 1, adjustment);
657 }
658 }
659
660 /* GNU v3 implementation of cplus_method_ptr_size. */
661
662 static int
663 gnuv3_method_ptr_size (struct type *type)
664 {
665 struct gdbarch *gdbarch = get_type_arch (type);
666
667 return 2 * TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
668 }
669
670 /* GNU v3 implementation of cplus_make_method_ptr. */
671
672 static void
673 gnuv3_make_method_ptr (struct type *type, gdb_byte *contents,
674 CORE_ADDR value, int is_virtual)
675 {
676 struct gdbarch *gdbarch = get_type_arch (type);
677 int size = TYPE_LENGTH (builtin_type (gdbarch)->builtin_data_ptr);
678 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
679
680 /* FIXME drow/2006-12-24: The adjustment of "this" is currently
681 always zero, since the method pointer is of the correct type.
682 But if the method pointer came from a base class, this is
683 incorrect - it should be the offset to the base. The best
684 fix might be to create the pointer to member pointing at the
685 base class and cast it to the derived class, but that requires
686 support for adjusting pointers to members when casting them -
687 not currently supported by GDB. */
688
689 if (!gdbarch_vbit_in_delta (gdbarch))
690 {
691 store_unsigned_integer (contents, size, byte_order, value | is_virtual);
692 store_unsigned_integer (contents + size, size, byte_order, 0);
693 }
694 else
695 {
696 store_unsigned_integer (contents, size, byte_order, value);
697 store_unsigned_integer (contents + size, size, byte_order, is_virtual);
698 }
699 }
700
701 /* GNU v3 implementation of cplus_method_ptr_to_value. */
702
703 static struct value *
704 gnuv3_method_ptr_to_value (struct value **this_p, struct value *method_ptr)
705 {
706 struct gdbarch *gdbarch;
707 const gdb_byte *contents = value_contents (method_ptr);
708 CORE_ADDR ptr_value;
709 struct type *self_type, *final_type, *method_type;
710 LONGEST adjustment;
711 int vbit;
712
713 self_type = TYPE_SELF_TYPE (check_typedef (value_type (method_ptr)));
714 final_type = lookup_pointer_type (self_type);
715
716 method_type = TYPE_TARGET_TYPE (check_typedef (value_type (method_ptr)));
717
718 /* Extract the pointer to member. */
719 gdbarch = get_type_arch (self_type);
720 vbit = gnuv3_decode_method_ptr (gdbarch, contents, &ptr_value, &adjustment);
721
722 /* First convert THIS to match the containing type of the pointer to
723 member. This cast may adjust the value of THIS. */
724 *this_p = value_cast (final_type, *this_p);
725
726 /* Then apply whatever adjustment is necessary. This creates a somewhat
727 strange pointer: it claims to have type FINAL_TYPE, but in fact it
728 might not be a valid FINAL_TYPE. For instance, it might be a
729 base class of FINAL_TYPE. And if it's not the primary base class,
730 then printing it out as a FINAL_TYPE object would produce some pretty
731 garbage.
732
733 But we don't really know the type of the first argument in
734 METHOD_TYPE either, which is why this happens. We can't
735 dereference this later as a FINAL_TYPE, but once we arrive in the
736 called method we'll have debugging information for the type of
737 "this" - and that'll match the value we produce here.
738
739 You can provoke this case by casting a Base::* to a Derived::*, for
740 instance. */
741 *this_p = value_cast (builtin_type (gdbarch)->builtin_data_ptr, *this_p);
742 *this_p = value_ptradd (*this_p, adjustment);
743 *this_p = value_cast (final_type, *this_p);
744
745 if (vbit)
746 {
747 LONGEST voffset;
748
749 voffset = ptr_value / TYPE_LENGTH (vtable_ptrdiff_type (gdbarch));
750 return gnuv3_get_virtual_fn (gdbarch, value_ind (*this_p),
751 method_type, voffset);
752 }
753 else
754 return value_from_pointer (lookup_pointer_type (method_type), ptr_value);
755 }
756
757 /* Objects of this type are stored in a hash table and a vector when
758 printing the vtables for a class. */
759
760 struct value_and_voffset
761 {
762 /* The value representing the object. */
763 struct value *value;
764
765 /* The maximum vtable offset we've found for any object at this
766 offset in the outermost object. */
767 int max_voffset;
768 };
769
770 typedef struct value_and_voffset *value_and_voffset_p;
771 DEF_VEC_P (value_and_voffset_p);
772
773 /* Hash function for value_and_voffset. */
774
775 static hashval_t
776 hash_value_and_voffset (const void *p)
777 {
778 const struct value_and_voffset *o = (const struct value_and_voffset *) p;
779
780 return value_address (o->value) + value_embedded_offset (o->value);
781 }
782
783 /* Equality function for value_and_voffset. */
784
785 static int
786 eq_value_and_voffset (const void *a, const void *b)
787 {
788 const struct value_and_voffset *ova = (const struct value_and_voffset *) a;
789 const struct value_and_voffset *ovb = (const struct value_and_voffset *) b;
790
791 return (value_address (ova->value) + value_embedded_offset (ova->value)
792 == value_address (ovb->value) + value_embedded_offset (ovb->value));
793 }
794
795 /* qsort comparison function for value_and_voffset. */
796
797 static int
798 compare_value_and_voffset (const void *a, const void *b)
799 {
800 const struct value_and_voffset * const *ova
801 = (const struct value_and_voffset * const *) a;
802 CORE_ADDR addra = (value_address ((*ova)->value)
803 + value_embedded_offset ((*ova)->value));
804 const struct value_and_voffset * const *ovb
805 = (const struct value_and_voffset * const *) b;
806 CORE_ADDR addrb = (value_address ((*ovb)->value)
807 + value_embedded_offset ((*ovb)->value));
808
809 if (addra < addrb)
810 return -1;
811 if (addra > addrb)
812 return 1;
813 return 0;
814 }
815
816 /* A helper function used when printing vtables. This determines the
817 key (most derived) sub-object at each address and also computes the
818 maximum vtable offset seen for the corresponding vtable. Updates
819 OFFSET_HASH and OFFSET_VEC with a new value_and_voffset object, if
820 needed. VALUE is the object to examine. */
821
822 static void
823 compute_vtable_size (htab_t offset_hash,
824 VEC (value_and_voffset_p) **offset_vec,
825 struct value *value)
826 {
827 int i;
828 struct type *type = check_typedef (value_type (value));
829 void **slot;
830 struct value_and_voffset search_vo, *current_vo;
831
832 gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT);
833
834 /* If the object is not dynamic, then we are done; as it cannot have
835 dynamic base types either. */
836 if (!gnuv3_dynamic_class (type))
837 return;
838
839 /* Update the hash and the vec, if needed. */
840 search_vo.value = value;
841 slot = htab_find_slot (offset_hash, &search_vo, INSERT);
842 if (*slot)
843 current_vo = (struct value_and_voffset *) *slot;
844 else
845 {
846 current_vo = XNEW (struct value_and_voffset);
847 current_vo->value = value;
848 current_vo->max_voffset = -1;
849 *slot = current_vo;
850 VEC_safe_push (value_and_voffset_p, *offset_vec, current_vo);
851 }
852
853 /* Update the value_and_voffset object with the highest vtable
854 offset from this class. */
855 for (i = 0; i < TYPE_NFN_FIELDS (type); ++i)
856 {
857 int j;
858 struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, i);
859
860 for (j = 0; j < TYPE_FN_FIELDLIST_LENGTH (type, i); ++j)
861 {
862 if (TYPE_FN_FIELD_VIRTUAL_P (fn, j))
863 {
864 int voffset = TYPE_FN_FIELD_VOFFSET (fn, j);
865
866 if (voffset > current_vo->max_voffset)
867 current_vo->max_voffset = voffset;
868 }
869 }
870 }
871
872 /* Recurse into base classes. */
873 for (i = 0; i < TYPE_N_BASECLASSES (type); ++i)
874 compute_vtable_size (offset_hash, offset_vec, value_field (value, i));
875 }
876
877 /* Helper for gnuv3_print_vtable that prints a single vtable. */
878
879 static void
880 print_one_vtable (struct gdbarch *gdbarch, struct value *value,
881 int max_voffset,
882 struct value_print_options *opts)
883 {
884 int i;
885 struct type *type = check_typedef (value_type (value));
886 struct value *vtable;
887 CORE_ADDR vt_addr;
888
889 vtable = gnuv3_get_vtable (gdbarch, type,
890 value_address (value)
891 + value_embedded_offset (value));
892 vt_addr = value_address (value_field (vtable,
893 vtable_field_virtual_functions));
894
895 printf_filtered (_("vtable for '%s' @ %s (subobject @ %s):\n"),
896 TYPE_SAFE_NAME (type),
897 paddress (gdbarch, vt_addr),
898 paddress (gdbarch, (value_address (value)
899 + value_embedded_offset (value))));
900
901 for (i = 0; i <= max_voffset; ++i)
902 {
903 /* Initialize it just to avoid a GCC false warning. */
904 CORE_ADDR addr = 0;
905 int got_error = 0;
906 struct value *vfn;
907
908 printf_filtered ("[%d]: ", i);
909
910 vfn = value_subscript (value_field (vtable,
911 vtable_field_virtual_functions),
912 i);
913
914 if (gdbarch_vtable_function_descriptors (gdbarch))
915 vfn = value_addr (vfn);
916
917 TRY
918 {
919 addr = value_as_address (vfn);
920 }
921 CATCH (ex, RETURN_MASK_ERROR)
922 {
923 printf_filtered (_("<error: %s>"), ex.message);
924 got_error = 1;
925 }
926 END_CATCH
927
928 if (!got_error)
929 print_function_pointer_address (opts, gdbarch, addr, gdb_stdout);
930 printf_filtered ("\n");
931 }
932 }
933
934 /* Implementation of the print_vtable method. */
935
936 static void
937 gnuv3_print_vtable (struct value *value)
938 {
939 struct gdbarch *gdbarch;
940 struct type *type;
941 struct value *vtable;
942 struct value_print_options opts;
943 htab_t offset_hash;
944 struct cleanup *cleanup;
945 VEC (value_and_voffset_p) *result_vec = NULL;
946 struct value_and_voffset *iter;
947 int i, count;
948
949 value = coerce_ref (value);
950 type = check_typedef (value_type (value));
951 if (TYPE_CODE (type) == TYPE_CODE_PTR)
952 {
953 value = value_ind (value);
954 type = check_typedef (value_type (value));
955 }
956
957 get_user_print_options (&opts);
958
959 /* Respect 'set print object'. */
960 if (opts.objectprint)
961 {
962 value = value_full_object (value, NULL, 0, 0, 0);
963 type = check_typedef (value_type (value));
964 }
965
966 gdbarch = get_type_arch (type);
967
968 vtable = NULL;
969 if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
970 vtable = gnuv3_get_vtable (gdbarch, type,
971 value_as_address (value_addr (value)));
972
973 if (!vtable)
974 {
975 printf_filtered (_("This object does not have a virtual function table\n"));
976 return;
977 }
978
979 offset_hash = htab_create_alloc (1, hash_value_and_voffset,
980 eq_value_and_voffset,
981 xfree, xcalloc, xfree);
982 cleanup = make_cleanup_htab_delete (offset_hash);
983 make_cleanup (VEC_cleanup (value_and_voffset_p), &result_vec);
984
985 compute_vtable_size (offset_hash, &result_vec, value);
986
987 qsort (VEC_address (value_and_voffset_p, result_vec),
988 VEC_length (value_and_voffset_p, result_vec),
989 sizeof (value_and_voffset_p),
990 compare_value_and_voffset);
991
992 count = 0;
993 for (i = 0; VEC_iterate (value_and_voffset_p, result_vec, i, iter); ++i)
994 {
995 if (iter->max_voffset >= 0)
996 {
997 if (count > 0)
998 printf_filtered ("\n");
999 print_one_vtable (gdbarch, iter->value, iter->max_voffset, &opts);
1000 ++count;
1001 }
1002 }
1003
1004 do_cleanups (cleanup);
1005 }
1006
1007 /* Return a GDB type representing `struct std::type_info', laid out
1008 appropriately for ARCH.
1009
1010 We use this function as the gdbarch per-architecture data
1011 initialization function. */
1012
1013 static void *
1014 build_std_type_info_type (struct gdbarch *arch)
1015 {
1016 struct type *t;
1017 struct field *field_list, *field;
1018 int offset;
1019 struct type *void_ptr_type
1020 = builtin_type (arch)->builtin_data_ptr;
1021 struct type *char_type
1022 = builtin_type (arch)->builtin_char;
1023 struct type *char_ptr_type
1024 = make_pointer_type (make_cv_type (1, 0, char_type, NULL), NULL);
1025
1026 field_list = XCNEWVEC (struct field, 2);
1027 field = &field_list[0];
1028 offset = 0;
1029
1030 /* The vtable. */
1031 FIELD_NAME (*field) = "_vptr.type_info";
1032 FIELD_TYPE (*field) = void_ptr_type;
1033 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
1034 offset += TYPE_LENGTH (FIELD_TYPE (*field));
1035 field++;
1036
1037 /* The name. */
1038 FIELD_NAME (*field) = "__name";
1039 FIELD_TYPE (*field) = char_ptr_type;
1040 SET_FIELD_BITPOS (*field, offset * TARGET_CHAR_BIT);
1041 offset += TYPE_LENGTH (FIELD_TYPE (*field));
1042 field++;
1043
1044 gdb_assert (field == (field_list + 2));
1045
1046 t = arch_type (arch, TYPE_CODE_STRUCT, offset, NULL);
1047 TYPE_NFIELDS (t) = field - field_list;
1048 TYPE_FIELDS (t) = field_list;
1049 TYPE_TAG_NAME (t) = "gdb_gnu_v3_type_info";
1050 INIT_CPLUS_SPECIFIC (t);
1051
1052 return t;
1053 }
1054
1055 /* Implement the 'get_typeid_type' method. */
1056
1057 static struct type *
1058 gnuv3_get_typeid_type (struct gdbarch *gdbarch)
1059 {
1060 struct symbol *typeinfo;
1061 struct type *typeinfo_type;
1062
1063 typeinfo = lookup_symbol ("std::type_info", NULL, STRUCT_DOMAIN,
1064 NULL).symbol;
1065 if (typeinfo == NULL)
1066 typeinfo_type
1067 = (struct type *) gdbarch_data (gdbarch, std_type_info_gdbarch_data);
1068 else
1069 typeinfo_type = SYMBOL_TYPE (typeinfo);
1070
1071 return typeinfo_type;
1072 }
1073
1074 /* Implement the 'get_typeid' method. */
1075
1076 static struct value *
1077 gnuv3_get_typeid (struct value *value)
1078 {
1079 struct type *typeinfo_type;
1080 struct type *type;
1081 struct gdbarch *gdbarch;
1082 struct cleanup *cleanup;
1083 struct value *result;
1084 std::string type_name, canonical;
1085
1086 /* We have to handle values a bit trickily here, to allow this code
1087 to work properly with non_lvalue values that are really just
1088 disguised types. */
1089 if (value_lval_const (value) == lval_memory)
1090 value = coerce_ref (value);
1091
1092 type = check_typedef (value_type (value));
1093
1094 /* In the non_lvalue case, a reference might have slipped through
1095 here. */
1096 if (TYPE_CODE (type) == TYPE_CODE_REF)
1097 type = check_typedef (TYPE_TARGET_TYPE (type));
1098
1099 /* Ignore top-level cv-qualifiers. */
1100 type = make_cv_type (0, 0, type, NULL);
1101 gdbarch = get_type_arch (type);
1102
1103 type_name = type_to_string (type);
1104 if (type_name.empty ())
1105 error (_("cannot find typeinfo for unnamed type"));
1106
1107 /* We need to canonicalize the type name here, because we do lookups
1108 using the demangled name, and so we must match the format it
1109 uses. E.g., GDB tends to use "const char *" as a type name, but
1110 the demangler uses "char const *". */
1111 canonical = cp_canonicalize_string (type_name.c_str ());
1112 if (!canonical.empty ())
1113 type_name = canonical;
1114
1115 typeinfo_type = gnuv3_get_typeid_type (gdbarch);
1116
1117 /* We check for lval_memory because in the "typeid (type-id)" case,
1118 the type is passed via a not_lval value object. */
1119 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
1120 && value_lval_const (value) == lval_memory
1121 && gnuv3_dynamic_class (type))
1122 {
1123 struct value *vtable, *typeinfo_value;
1124 CORE_ADDR address = value_address (value) + value_embedded_offset (value);
1125
1126 vtable = gnuv3_get_vtable (gdbarch, type, address);
1127 if (vtable == NULL)
1128 error (_("cannot find typeinfo for object of type '%s'"),
1129 type_name.c_str ());
1130 typeinfo_value = value_field (vtable, vtable_field_type_info);
1131 result = value_ind (value_cast (make_pointer_type (typeinfo_type, NULL),
1132 typeinfo_value));
1133 }
1134 else
1135 {
1136 std::string sym_name = std::string ("typeinfo for ") + type_name;
1137 bound_minimal_symbol minsym
1138 = lookup_minimal_symbol (sym_name.c_str (), NULL, NULL);
1139
1140 if (minsym.minsym == NULL)
1141 error (_("could not find typeinfo symbol for '%s'"), type_name.c_str ());
1142
1143 result = value_at_lazy (typeinfo_type, BMSYMBOL_VALUE_ADDRESS (minsym));
1144 }
1145
1146 return result;
1147 }
1148
1149 /* Implement the 'get_typename_from_type_info' method. */
1150
1151 static std::string
1152 gnuv3_get_typename_from_type_info (struct value *type_info_ptr)
1153 {
1154 struct gdbarch *gdbarch = get_type_arch (value_type (type_info_ptr));
1155 struct bound_minimal_symbol typeinfo_sym;
1156 CORE_ADDR addr;
1157 const char *symname;
1158 const char *class_name;
1159 const char *atsign;
1160
1161 addr = value_as_address (type_info_ptr);
1162 typeinfo_sym = lookup_minimal_symbol_by_pc (addr);
1163 if (typeinfo_sym.minsym == NULL)
1164 error (_("could not find minimal symbol for typeinfo address %s"),
1165 paddress (gdbarch, addr));
1166
1167 #define TYPEINFO_PREFIX "typeinfo for "
1168 #define TYPEINFO_PREFIX_LEN (sizeof (TYPEINFO_PREFIX) - 1)
1169 symname = MSYMBOL_DEMANGLED_NAME (typeinfo_sym.minsym);
1170 if (symname == NULL || strncmp (symname, TYPEINFO_PREFIX,
1171 TYPEINFO_PREFIX_LEN))
1172 error (_("typeinfo symbol '%s' has unexpected name"),
1173 MSYMBOL_LINKAGE_NAME (typeinfo_sym.minsym));
1174 class_name = symname + TYPEINFO_PREFIX_LEN;
1175
1176 /* Strip off @plt and version suffixes. */
1177 atsign = strchr (class_name, '@');
1178 if (atsign != NULL)
1179 return std::string (class_name, atsign - class_name);
1180 return class_name;
1181 }
1182
1183 /* Implement the 'get_type_from_type_info' method. */
1184
1185 static struct type *
1186 gnuv3_get_type_from_type_info (struct value *type_info_ptr)
1187 {
1188 /* We have to parse the type name, since in general there is not a
1189 symbol for a type. This is somewhat bogus since there may be a
1190 mis-parse. Another approach might be to re-use the demangler's
1191 internal form to reconstruct the type somehow. */
1192 std::string type_name = gnuv3_get_typename_from_type_info (type_info_ptr);
1193 expression_up expr (parse_expression (type_name.c_str ()));
1194 struct value *type_val = evaluate_type (expr.get ());
1195 return value_type (type_val);
1196 }
1197
1198 /* Determine if we are currently in a C++ thunk. If so, get the address
1199 of the routine we are thunking to and continue to there instead. */
1200
1201 static CORE_ADDR
1202 gnuv3_skip_trampoline (struct frame_info *frame, CORE_ADDR stop_pc)
1203 {
1204 CORE_ADDR real_stop_pc, method_stop_pc, func_addr;
1205 struct gdbarch *gdbarch = get_frame_arch (frame);
1206 struct bound_minimal_symbol thunk_sym, fn_sym;
1207 struct obj_section *section;
1208 const char *thunk_name, *fn_name;
1209
1210 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
1211 if (real_stop_pc == 0)
1212 real_stop_pc = stop_pc;
1213
1214 /* Find the linker symbol for this potential thunk. */
1215 thunk_sym = lookup_minimal_symbol_by_pc (real_stop_pc);
1216 section = find_pc_section (real_stop_pc);
1217 if (thunk_sym.minsym == NULL || section == NULL)
1218 return 0;
1219
1220 /* The symbol's demangled name should be something like "virtual
1221 thunk to FUNCTION", where FUNCTION is the name of the function
1222 being thunked to. */
1223 thunk_name = MSYMBOL_DEMANGLED_NAME (thunk_sym.minsym);
1224 if (thunk_name == NULL || strstr (thunk_name, " thunk to ") == NULL)
1225 return 0;
1226
1227 fn_name = strstr (thunk_name, " thunk to ") + strlen (" thunk to ");
1228 fn_sym = lookup_minimal_symbol (fn_name, NULL, section->objfile);
1229 if (fn_sym.minsym == NULL)
1230 return 0;
1231
1232 method_stop_pc = BMSYMBOL_VALUE_ADDRESS (fn_sym);
1233
1234 /* Some targets have minimal symbols pointing to function descriptors
1235 (powerpc 64 for example). Make sure to retrieve the address
1236 of the real function from the function descriptor before passing on
1237 the address to other layers of GDB. */
1238 func_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, method_stop_pc,
1239 &current_target);
1240 if (func_addr != 0)
1241 method_stop_pc = func_addr;
1242
1243 real_stop_pc = gdbarch_skip_trampoline_code
1244 (gdbarch, frame, method_stop_pc);
1245 if (real_stop_pc == 0)
1246 real_stop_pc = method_stop_pc;
1247
1248 return real_stop_pc;
1249 }
1250
1251 /* Return nonzero if a type should be passed by reference.
1252
1253 The rule in the v3 ABI document comes from section 3.1.1. If the
1254 type has a non-trivial copy constructor or destructor, then the
1255 caller must make a copy (by calling the copy constructor if there
1256 is one or perform the copy itself otherwise), pass the address of
1257 the copy, and then destroy the temporary (if necessary).
1258
1259 For return values with non-trivial copy constructors or
1260 destructors, space will be allocated in the caller, and a pointer
1261 will be passed as the first argument (preceding "this").
1262
1263 We don't have a bulletproof mechanism for determining whether a
1264 constructor or destructor is trivial. For GCC and DWARF2 debug
1265 information, we can check the artificial flag.
1266
1267 We don't do anything with the constructors or destructors,
1268 but we have to get the argument passing right anyway. */
1269 static int
1270 gnuv3_pass_by_reference (struct type *type)
1271 {
1272 int fieldnum, fieldelem;
1273
1274 type = check_typedef (type);
1275
1276 /* We're only interested in things that can have methods. */
1277 if (TYPE_CODE (type) != TYPE_CODE_STRUCT
1278 && TYPE_CODE (type) != TYPE_CODE_UNION)
1279 return 0;
1280
1281 /* A dynamic class has a non-trivial copy constructor.
1282 See c++98 section 12.8 Copying class objects [class.copy]. */
1283 if (gnuv3_dynamic_class (type))
1284 return 1;
1285
1286 for (fieldnum = 0; fieldnum < TYPE_NFN_FIELDS (type); fieldnum++)
1287 for (fieldelem = 0; fieldelem < TYPE_FN_FIELDLIST_LENGTH (type, fieldnum);
1288 fieldelem++)
1289 {
1290 struct fn_field *fn = TYPE_FN_FIELDLIST1 (type, fieldnum);
1291 const char *name = TYPE_FN_FIELDLIST_NAME (type, fieldnum);
1292 struct type *fieldtype = TYPE_FN_FIELD_TYPE (fn, fieldelem);
1293
1294 /* If this function is marked as artificial, it is compiler-generated,
1295 and we assume it is trivial. */
1296 if (TYPE_FN_FIELD_ARTIFICIAL (fn, fieldelem))
1297 continue;
1298
1299 /* If we've found a destructor, we must pass this by reference. */
1300 if (name[0] == '~')
1301 return 1;
1302
1303 /* If the mangled name of this method doesn't indicate that it
1304 is a constructor, we're not interested.
1305
1306 FIXME drow/2007-09-23: We could do this using the name of
1307 the method and the name of the class instead of dealing
1308 with the mangled name. We don't have a convenient function
1309 to strip off both leading scope qualifiers and trailing
1310 template arguments yet. */
1311 if (!is_constructor_name (TYPE_FN_FIELD_PHYSNAME (fn, fieldelem))
1312 && !TYPE_FN_FIELD_CONSTRUCTOR (fn, fieldelem))
1313 continue;
1314
1315 /* If this method takes two arguments, and the second argument is
1316 a reference to this class, then it is a copy constructor. */
1317 if (TYPE_NFIELDS (fieldtype) == 2)
1318 {
1319 struct type *arg_type = TYPE_FIELD_TYPE (fieldtype, 1);
1320
1321 if (TYPE_CODE (arg_type) == TYPE_CODE_REF)
1322 {
1323 struct type *arg_target_type;
1324
1325 arg_target_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
1326 if (class_types_same_p (arg_target_type, type))
1327 return 1;
1328 }
1329 }
1330 }
1331
1332 /* Even if all the constructors and destructors were artificial, one
1333 of them may have invoked a non-artificial constructor or
1334 destructor in a base class. If any base class needs to be passed
1335 by reference, so does this class. Similarly for members, which
1336 are constructed whenever this class is. We do not need to worry
1337 about recursive loops here, since we are only looking at members
1338 of complete class type. Also ignore any static members. */
1339 for (fieldnum = 0; fieldnum < TYPE_NFIELDS (type); fieldnum++)
1340 if (! field_is_static (&TYPE_FIELD (type, fieldnum))
1341 && gnuv3_pass_by_reference (TYPE_FIELD_TYPE (type, fieldnum)))
1342 return 1;
1343
1344 return 0;
1345 }
1346
1347 static void
1348 init_gnuv3_ops (void)
1349 {
1350 vtable_type_gdbarch_data
1351 = gdbarch_data_register_post_init (build_gdb_vtable_type);
1352 std_type_info_gdbarch_data
1353 = gdbarch_data_register_post_init (build_std_type_info_type);
1354
1355 gnu_v3_abi_ops.shortname = "gnu-v3";
1356 gnu_v3_abi_ops.longname = "GNU G++ Version 3 ABI";
1357 gnu_v3_abi_ops.doc = "G++ Version 3 ABI";
1358 gnu_v3_abi_ops.is_destructor_name =
1359 (enum dtor_kinds (*) (const char *))is_gnu_v3_mangled_dtor;
1360 gnu_v3_abi_ops.is_constructor_name =
1361 (enum ctor_kinds (*) (const char *))is_gnu_v3_mangled_ctor;
1362 gnu_v3_abi_ops.is_vtable_name = gnuv3_is_vtable_name;
1363 gnu_v3_abi_ops.is_operator_name = gnuv3_is_operator_name;
1364 gnu_v3_abi_ops.rtti_type = gnuv3_rtti_type;
1365 gnu_v3_abi_ops.virtual_fn_field = gnuv3_virtual_fn_field;
1366 gnu_v3_abi_ops.baseclass_offset = gnuv3_baseclass_offset;
1367 gnu_v3_abi_ops.print_method_ptr = gnuv3_print_method_ptr;
1368 gnu_v3_abi_ops.method_ptr_size = gnuv3_method_ptr_size;
1369 gnu_v3_abi_ops.make_method_ptr = gnuv3_make_method_ptr;
1370 gnu_v3_abi_ops.method_ptr_to_value = gnuv3_method_ptr_to_value;
1371 gnu_v3_abi_ops.print_vtable = gnuv3_print_vtable;
1372 gnu_v3_abi_ops.get_typeid = gnuv3_get_typeid;
1373 gnu_v3_abi_ops.get_typeid_type = gnuv3_get_typeid_type;
1374 gnu_v3_abi_ops.get_type_from_type_info = gnuv3_get_type_from_type_info;
1375 gnu_v3_abi_ops.get_typename_from_type_info
1376 = gnuv3_get_typename_from_type_info;
1377 gnu_v3_abi_ops.skip_trampoline = gnuv3_skip_trampoline;
1378 gnu_v3_abi_ops.pass_by_reference = gnuv3_pass_by_reference;
1379 }
1380
1381 extern initialize_file_ftype _initialize_gnu_v3_abi; /* -Wmissing-prototypes */
1382
1383 void
1384 _initialize_gnu_v3_abi (void)
1385 {
1386 init_gnuv3_ops ();
1387
1388 register_cp_abi (&gnu_v3_abi_ops);
1389 set_cp_abi_as_auto_default (gnu_v3_abi_ops.shortname);
1390 }