1 /* Support for printing C++ values for GDB, the GNU debugger.
3 Copyright (C) 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
4 2000, 2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_obstack.h"
26 #include "expression.h"
32 #include "gdb_string.h"
37 #include "cp-support.h"
39 #include "python/python.h"
41 /* Controls printing of vtbl's. */
43 show_vtblprint (struct ui_file
*file
, int from_tty
,
44 struct cmd_list_element
*c
, const char *value
)
46 fprintf_filtered (file
, _("\
47 Printing of C++ virtual function tables is %s.\n"),
51 /* Controls looking up an object's derived type using what we find in
54 show_objectprint (struct ui_file
*file
, int from_tty
,
55 struct cmd_list_element
*c
,
58 fprintf_filtered (file
, _("\
59 Printing of object's derived type based on vtable info is %s.\n"),
64 show_static_field_print (struct ui_file
*file
, int from_tty
,
65 struct cmd_list_element
*c
,
68 fprintf_filtered (file
,
69 _("Printing of C++ static members is %s.\n"),
74 static struct obstack dont_print_vb_obstack
;
75 static struct obstack dont_print_statmem_obstack
;
76 static struct obstack dont_print_stat_array_obstack
;
78 extern void _initialize_cp_valprint (void);
80 static void cp_print_static_field (struct type
*, struct value
*,
81 struct ui_file
*, int,
82 const struct value_print_options
*);
84 static void cp_print_value (struct type
*, struct type
*,
85 const gdb_byte
*, int,
86 CORE_ADDR
, struct ui_file
*,
87 int, const struct value
*,
88 const struct value_print_options
*,
92 /* GCC versions after 2.4.5 use this. */
93 const char vtbl_ptr_name
[] = "__vtbl_ptr_type";
95 /* Return truth value for assertion that TYPE is of the type
96 "pointer to virtual function". */
99 cp_is_vtbl_ptr_type (struct type
*type
)
101 char *typename
= type_name_no_tag (type
);
103 return (typename
!= NULL
&& !strcmp (typename
, vtbl_ptr_name
));
106 /* Return truth value for the assertion that TYPE is of the type
107 "pointer to virtual function table". */
110 cp_is_vtbl_member (struct type
*type
)
112 /* With older versions of g++, the vtbl field pointed to an array of
113 structures. Nowadays it points directly to the structure. */
114 if (TYPE_CODE (type
) == TYPE_CODE_PTR
)
116 type
= TYPE_TARGET_TYPE (type
);
117 if (TYPE_CODE (type
) == TYPE_CODE_ARRAY
)
119 type
= TYPE_TARGET_TYPE (type
);
120 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
/* if not using thunks */
121 || TYPE_CODE (type
) == TYPE_CODE_PTR
) /* if using thunks */
123 /* Virtual functions tables are full of pointers
124 to virtual functions. */
125 return cp_is_vtbl_ptr_type (type
);
128 else if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
) /* if not using thunks */
130 return cp_is_vtbl_ptr_type (type
);
132 else if (TYPE_CODE (type
) == TYPE_CODE_PTR
) /* if using thunks */
134 /* The type name of the thunk pointer is NULL when using
135 dwarf2. We could test for a pointer to a function, but
136 there is no type info for the virtual table either, so it
138 return cp_is_vtbl_ptr_type (type
);
144 /* Mutually recursive subroutines of cp_print_value and c_val_print to
145 print out a structure's fields: cp_print_value_fields and
148 TYPE, VALADDR, ADDRESS, STREAM, RECURSE, and OPTIONS have the same
149 meanings as in cp_print_value and c_val_print.
151 2nd argument REAL_TYPE is used to carry over the type of the
152 derived class across the recursion to base classes.
154 DONT_PRINT is an array of baseclass types that we should not print,
155 or zero if called from top level. */
158 cp_print_value_fields (struct type
*type
, struct type
*real_type
,
159 const gdb_byte
*valaddr
, int offset
,
160 CORE_ADDR address
, struct ui_file
*stream
,
161 int recurse
, const struct value
*val
,
162 const struct value_print_options
*options
,
163 struct type
**dont_print_vb
,
164 int dont_print_statmem
)
166 int i
, len
, n_baseclasses
;
168 static int last_set_recurse
= -1;
170 CHECK_TYPEDEF (type
);
174 /* Any object can be left on obstacks only during an unexpected
177 if (obstack_object_size (&dont_print_statmem_obstack
) > 0)
179 obstack_free (&dont_print_statmem_obstack
, NULL
);
180 obstack_begin (&dont_print_statmem_obstack
,
181 32 * sizeof (CORE_ADDR
));
183 if (obstack_object_size (&dont_print_stat_array_obstack
) > 0)
185 obstack_free (&dont_print_stat_array_obstack
, NULL
);
186 obstack_begin (&dont_print_stat_array_obstack
,
187 32 * sizeof (struct type
*));
191 fprintf_filtered (stream
, "{");
192 len
= TYPE_NFIELDS (type
);
193 n_baseclasses
= TYPE_N_BASECLASSES (type
);
195 /* First, print out baseclasses such that we don't print
196 duplicates of virtual baseclasses. */
198 if (n_baseclasses
> 0)
199 cp_print_value (type
, real_type
, valaddr
,
200 offset
, address
, stream
,
201 recurse
+ 1, val
, options
,
204 /* Second, print out data fields */
206 /* If there are no data fields, skip this part */
207 if (len
== n_baseclasses
|| !len
)
208 fprintf_filtered (stream
, "<No data fields>");
211 int statmem_obstack_initial_size
= 0;
212 int stat_array_obstack_initial_size
= 0;
214 if (dont_print_statmem
== 0)
216 statmem_obstack_initial_size
=
217 obstack_object_size (&dont_print_statmem_obstack
);
219 if (last_set_recurse
!= recurse
)
221 stat_array_obstack_initial_size
=
222 obstack_object_size (&dont_print_stat_array_obstack
);
224 last_set_recurse
= recurse
;
228 for (i
= n_baseclasses
; i
< len
; i
++)
230 /* If requested, skip printing of static fields. */
231 if (!options
->static_field_print
232 && field_is_static (&TYPE_FIELD (type
, i
)))
236 fprintf_filtered (stream
, ", ");
237 else if (n_baseclasses
> 0)
241 fprintf_filtered (stream
, "\n");
242 print_spaces_filtered (2 + 2 * recurse
, stream
);
243 fputs_filtered ("members of ", stream
);
244 fputs_filtered (type_name_no_tag (type
), stream
);
245 fputs_filtered (": ", stream
);
252 fprintf_filtered (stream
, "\n");
253 print_spaces_filtered (2 + 2 * recurse
, stream
);
257 wrap_here (n_spaces (2 + 2 * recurse
));
259 if (options
->inspect_it
)
261 if (TYPE_CODE (TYPE_FIELD_TYPE (type
, i
)) == TYPE_CODE_PTR
)
262 fputs_filtered ("\"( ptr \"", stream
);
264 fputs_filtered ("\"( nodef \"", stream
);
265 if (field_is_static (&TYPE_FIELD (type
, i
)))
266 fputs_filtered ("static ", stream
);
267 fprintf_symbol_filtered (stream
,
268 TYPE_FIELD_NAME (type
, i
),
269 current_language
->la_language
,
270 DMGL_PARAMS
| DMGL_ANSI
);
271 fputs_filtered ("\" \"", stream
);
272 fprintf_symbol_filtered (stream
,
273 TYPE_FIELD_NAME (type
, i
),
274 current_language
->la_language
,
275 DMGL_PARAMS
| DMGL_ANSI
);
276 fputs_filtered ("\") \"", stream
);
280 annotate_field_begin (TYPE_FIELD_TYPE (type
, i
));
282 if (field_is_static (&TYPE_FIELD (type
, i
)))
283 fputs_filtered ("static ", stream
);
284 fprintf_symbol_filtered (stream
,
285 TYPE_FIELD_NAME (type
, i
),
286 current_language
->la_language
,
287 DMGL_PARAMS
| DMGL_ANSI
);
288 annotate_field_name_end ();
289 /* Do not print leading '=' in case of anonymous
291 if (strcmp (TYPE_FIELD_NAME (type
, i
), ""))
292 fputs_filtered (" = ", stream
);
293 annotate_field_value ();
296 if (!field_is_static (&TYPE_FIELD (type
, i
))
297 && TYPE_FIELD_PACKED (type
, i
))
301 /* Bitfields require special handling, especially due to
302 byte order problems. */
303 if (TYPE_FIELD_IGNORE (type
, i
))
305 fputs_filtered ("<optimized out or zero length>", stream
);
307 else if (value_bits_synthetic_pointer (val
,
308 TYPE_FIELD_BITPOS (type
,
310 TYPE_FIELD_BITSIZE (type
,
313 fputs_filtered (_("<synthetic pointer>"), stream
);
315 else if (!value_bits_valid (val
,
316 TYPE_FIELD_BITPOS (type
, i
),
317 TYPE_FIELD_BITSIZE (type
, i
)))
319 fputs_filtered (_("<value optimized out>"), stream
);
323 struct value_print_options opts
= *options
;
326 v
= value_from_longest
327 (TYPE_FIELD_TYPE (type
, i
),
328 unpack_field_as_long (type
, valaddr
+ offset
, i
));
330 common_val_print (v
, stream
, recurse
+ 1, &opts
,
336 if (TYPE_FIELD_IGNORE (type
, i
))
338 fputs_filtered ("<optimized out or zero length>",
341 else if (field_is_static (&TYPE_FIELD (type
, i
)))
343 struct value
*v
= value_static_field (type
, i
);
346 fputs_filtered ("<optimized out>", stream
);
348 cp_print_static_field (TYPE_FIELD_TYPE (type
, i
),
349 v
, stream
, recurse
+ 1,
354 struct value_print_options opts
= *options
;
357 val_print (TYPE_FIELD_TYPE (type
, i
),
359 offset
+ TYPE_FIELD_BITPOS (type
, i
) / 8,
361 stream
, recurse
+ 1, val
, &opts
,
365 annotate_field_end ();
368 if (dont_print_statmem
== 0)
370 int obstack_final_size
=
371 obstack_object_size (&dont_print_statmem_obstack
);
373 if (obstack_final_size
> statmem_obstack_initial_size
)
375 /* In effect, a pop of the printed-statics stack. */
378 obstack_next_free (&dont_print_statmem_obstack
) -
379 (obstack_final_size
- statmem_obstack_initial_size
);
381 obstack_free (&dont_print_statmem_obstack
,
385 if (last_set_recurse
!= recurse
)
387 int obstack_final_size
=
388 obstack_object_size (&dont_print_stat_array_obstack
);
390 if (obstack_final_size
> stat_array_obstack_initial_size
)
393 obstack_next_free (&dont_print_stat_array_obstack
)
394 - (obstack_final_size
395 - stat_array_obstack_initial_size
);
397 obstack_free (&dont_print_stat_array_obstack
,
400 last_set_recurse
= -1;
406 fprintf_filtered (stream
, "\n");
407 print_spaces_filtered (2 * recurse
, stream
);
409 } /* if there are data fields */
411 fprintf_filtered (stream
, "}");
414 /* Like cp_print_value_fields, but find the runtime type of the object
415 and pass it as the `real_type' argument to cp_print_value_fields.
416 This function is a hack to work around the fact that
417 common_val_print passes the embedded offset to val_print, but not
418 the enclosing type. */
421 cp_print_value_fields_rtti (struct type
*type
,
422 const gdb_byte
*valaddr
, int offset
,
424 struct ui_file
*stream
, int recurse
,
425 const struct value
*val
,
426 const struct value_print_options
*options
,
427 struct type
**dont_print_vb
,
428 int dont_print_statmem
)
430 struct type
*real_type
= NULL
;
432 /* We require all bits to be valid in order to attempt a
434 if (value_bits_valid (val
, TARGET_CHAR_BIT
* offset
,
435 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
438 int full
, top
, using_enc
;
440 /* Ugh, we have to convert back to a value here. */
441 value
= value_from_contents_and_address (type
, valaddr
+ offset
,
443 /* We don't actually care about most of the result here -- just
444 the type. We already have the correct offset, due to how
445 val_print was initially called. */
446 real_type
= value_rtti_type (value
, &full
, &top
, &using_enc
);
452 cp_print_value_fields (type
, real_type
, valaddr
, offset
,
453 address
, stream
, recurse
, val
, options
,
454 dont_print_vb
, dont_print_statmem
);
457 /* Special val_print routine to avoid printing multiple copies of
458 virtual baseclasses. */
461 cp_print_value (struct type
*type
, struct type
*real_type
,
462 const gdb_byte
*valaddr
, int offset
,
463 CORE_ADDR address
, struct ui_file
*stream
,
464 int recurse
, const struct value
*val
,
465 const struct value_print_options
*options
,
466 struct type
**dont_print_vb
)
468 struct type
**last_dont_print
469 = (struct type
**) obstack_next_free (&dont_print_vb_obstack
);
470 struct obstack tmp_obstack
= dont_print_vb_obstack
;
471 int i
, n_baseclasses
= TYPE_N_BASECLASSES (type
);
473 struct type
*thistype
;
475 if (dont_print_vb
== 0)
477 /* If we're at top level, carve out a completely fresh chunk of
478 the obstack and use that until this particular invocation
480 /* Bump up the high-water mark. Now alpha is omega. */
481 obstack_finish (&dont_print_vb_obstack
);
484 for (i
= 0; i
< n_baseclasses
; i
++)
488 struct type
*baseclass
= check_typedef (TYPE_BASECLASS (type
, i
));
489 char *basename
= TYPE_NAME (baseclass
);
490 const gdb_byte
*base_valaddr
;
492 if (BASETYPE_VIA_VIRTUAL (type
, i
))
494 struct type
**first_dont_print
495 = (struct type
**) obstack_base (&dont_print_vb_obstack
);
497 int j
= (struct type
**)
498 obstack_next_free (&dont_print_vb_obstack
) - first_dont_print
;
501 if (baseclass
== first_dont_print
[j
])
504 obstack_ptr_grow (&dont_print_vb_obstack
, baseclass
);
508 thistype
= real_type
;
510 boffset
= baseclass_offset (type
, i
, valaddr
+ offset
,
512 skip
= ((boffset
== -1) || (boffset
+ offset
) < 0) ? 1 : -1;
514 if (BASETYPE_VIA_VIRTUAL (type
, i
))
516 /* The virtual base class pointer might have been clobbered
517 by the user program. Make sure that it still points to a
518 valid memory location. */
521 && ((boffset
+ offset
) < 0
522 || (boffset
+ offset
) >= TYPE_LENGTH (real_type
)))
524 /* FIXME (alloca): unsafe if baseclass is really really
526 gdb_byte
*buf
= alloca (TYPE_LENGTH (baseclass
));
529 if (target_read_memory (address
+ boffset
, buf
,
530 TYPE_LENGTH (baseclass
)) != 0)
532 address
= address
+ boffset
;
535 thistype
= baseclass
;
538 base_valaddr
= valaddr
;
541 base_valaddr
= valaddr
;
543 /* Now do the printing. */
546 fprintf_filtered (stream
, "\n");
547 print_spaces_filtered (2 * recurse
, stream
);
549 fputs_filtered ("<", stream
);
550 /* Not sure what the best notation is in the case where there is
551 no baseclass name. */
552 fputs_filtered (basename
? basename
: "", stream
);
553 fputs_filtered ("> = ", stream
);
557 fprintf_filtered (stream
, "<invalid address>");
562 /* Attempt to run the Python pretty-printers on the
563 baseclass if possible. */
565 result
= apply_val_pretty_printer (baseclass
, base_valaddr
,
566 thisoffset
+ boffset
,
573 cp_print_value_fields (baseclass
, thistype
, base_valaddr
,
574 thisoffset
+ boffset
, address
,
575 stream
, recurse
, val
, options
,
577 obstack_base (&dont_print_vb_obstack
)),
580 fputs_filtered (", ", stream
);
586 if (dont_print_vb
== 0)
588 /* Free the space used to deal with the printing
589 of this type from top level. */
590 obstack_free (&dont_print_vb_obstack
, last_dont_print
);
591 /* Reset watermark so that we can continue protecting
592 ourselves from whatever we were protecting ourselves. */
593 dont_print_vb_obstack
= tmp_obstack
;
597 /* Print value of a static member. To avoid infinite recursion when
598 printing a class that contains a static instance of the class, we
599 keep the addresses of all printed static member classes in an
600 obstack and refuse to print them more than once.
602 VAL contains the value to print, TYPE, STREAM, RECURSE, and OPTIONS
603 have the same meanings as in c_val_print. */
606 cp_print_static_field (struct type
*type
,
608 struct ui_file
*stream
,
610 const struct value_print_options
*options
)
612 struct value_print_options opts
;
614 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
)
616 CORE_ADDR
*first_dont_print
;
621 = (CORE_ADDR
*) obstack_base (&dont_print_statmem_obstack
);
622 i
= obstack_object_size (&dont_print_statmem_obstack
)
623 / sizeof (CORE_ADDR
);
627 if (value_address (val
) == first_dont_print
[i
])
629 fputs_filtered ("<same as static member of an already"
636 addr
= value_address (val
);
637 obstack_grow (&dont_print_statmem_obstack
, (char *) &addr
,
639 CHECK_TYPEDEF (type
);
640 cp_print_value_fields (type
, value_enclosing_type (val
),
641 value_contents_for_printing (val
),
642 value_embedded_offset (val
), addr
,
643 stream
, recurse
, val
,
648 if (TYPE_CODE (type
) == TYPE_CODE_ARRAY
)
650 struct type
**first_dont_print
;
652 struct type
*target_type
= TYPE_TARGET_TYPE (type
);
655 = (struct type
**) obstack_base (&dont_print_stat_array_obstack
);
656 i
= obstack_object_size (&dont_print_stat_array_obstack
)
657 / sizeof (struct type
*);
661 if (target_type
== first_dont_print
[i
])
663 fputs_filtered ("<same as static member of an already"
670 obstack_grow (&dont_print_stat_array_obstack
,
671 (char *) &target_type
,
672 sizeof (struct type
*));
677 val_print (type
, value_contents_for_printing (val
),
678 value_embedded_offset (val
),
680 stream
, recurse
, val
,
681 &opts
, current_language
);
685 /* Find the field in *DOMAIN, or its non-virtual base classes, with
686 bit offset OFFSET. Set *DOMAIN to the containing type and *FIELDNO
687 to the containing field number. If OFFSET is not exactly at the
688 start of some field, set *DOMAIN to NULL. */
691 cp_find_class_member (struct type
**domain_p
, int *fieldno
,
698 *domain_p
= check_typedef (*domain_p
);
700 len
= TYPE_NFIELDS (domain
);
702 for (i
= TYPE_N_BASECLASSES (domain
); i
< len
; i
++)
704 LONGEST bitpos
= TYPE_FIELD_BITPOS (domain
, i
);
707 if (offset
== bitpos
)
714 for (i
= 0; i
< TYPE_N_BASECLASSES (domain
); i
++)
716 LONGEST bitpos
= TYPE_FIELD_BITPOS (domain
, i
);
717 LONGEST bitsize
= 8 * TYPE_LENGTH (TYPE_FIELD_TYPE (domain
, i
));
719 if (offset
>= bitpos
&& offset
< bitpos
+ bitsize
)
721 *domain_p
= TYPE_FIELD_TYPE (domain
, i
);
722 cp_find_class_member (domain_p
, fieldno
, offset
- bitpos
);
731 cp_print_class_member (const gdb_byte
*valaddr
, struct type
*type
,
732 struct ui_file
*stream
, char *prefix
)
734 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
736 /* VAL is a byte offset into the structure type DOMAIN.
737 Find the name of the field for that offset and
739 struct type
*domain
= TYPE_DOMAIN_TYPE (type
);
741 unsigned int fieldno
;
743 val
= extract_signed_integer (valaddr
,
747 /* Pointers to data members are usually byte offsets into an object.
748 Because a data member can have offset zero, and a NULL pointer to
749 member must be distinct from any valid non-NULL pointer to
750 member, either the value is biased or the NULL value has a
751 special representation; both are permitted by ISO C++. HP aCC
752 used a bias of 0x20000000; HP cfront used a bias of 1; g++ 3.x
753 and other compilers which use the Itanium ABI use -1 as the NULL
754 value. GDB only supports that last form; to add support for
755 another form, make this into a cp-abi hook. */
759 fprintf_filtered (stream
, "NULL");
763 cp_find_class_member (&domain
, &fieldno
, val
<< 3);
769 fputs_filtered (prefix
, stream
);
770 name
= type_name_no_tag (domain
);
772 fputs_filtered (name
, stream
);
774 c_type_print_base (domain
, stream
, 0, 0);
775 fprintf_filtered (stream
, "::");
776 fputs_filtered (TYPE_FIELD_NAME (domain
, fieldno
), stream
);
779 fprintf_filtered (stream
, "%ld", (long) val
);
784 _initialize_cp_valprint (void)
786 add_setshow_boolean_cmd ("static-members", class_support
,
787 &user_print_options
.static_field_print
, _("\
788 Set printing of C++ static members."), _("\
789 Show printing of C++ static members."), NULL
,
791 show_static_field_print
,
792 &setprintlist
, &showprintlist
);
794 add_setshow_boolean_cmd ("vtbl", class_support
,
795 &user_print_options
.vtblprint
, _("\
796 Set printing of C++ virtual function tables."), _("\
797 Show printing of C++ virtual function tables."), NULL
,
800 &setprintlist
, &showprintlist
);
802 add_setshow_boolean_cmd ("object", class_support
,
803 &user_print_options
.objectprint
, _("\
804 Set printing of object's derived type based on vtable info."), _("\
805 Show printing of object's derived type based on vtable info."), NULL
,
808 &setprintlist
, &showprintlist
);
810 obstack_begin (&dont_print_stat_array_obstack
,
811 32 * sizeof (struct type
*));
812 obstack_begin (&dont_print_statmem_obstack
,
813 32 * sizeof (CORE_ADDR
));
814 obstack_begin (&dont_print_vb_obstack
,
815 32 * sizeof (struct type
*));