1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
2 Copyright 1986, 87, 89, 91, 93, 94, 95, 96, 97, 1998
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 #include "gdb_string.h"
36 /* Prototypes for exported functions. */
38 void _initialize_values
PARAMS ((void));
40 /* Prototypes for local functions. */
42 static value_ptr value_headof
PARAMS ((value_ptr
, struct type
*,
45 static void show_values
PARAMS ((char *, int));
47 static void show_convenience
PARAMS ((char *, int));
49 static int vb_match
PARAMS ((struct type
*, int, struct type
*));
51 /* The value-history records all the values printed
52 by print commands during this session. Each chunk
53 records 60 consecutive values. The first chunk on
54 the chain records the most recent values.
55 The total number of values is in value_history_count. */
57 #define VALUE_HISTORY_CHUNK 60
59 struct value_history_chunk
61 struct value_history_chunk
*next
;
62 value_ptr values
[VALUE_HISTORY_CHUNK
];
65 /* Chain of chunks now in use. */
67 static struct value_history_chunk
*value_history_chain
;
69 static int value_history_count
; /* Abs number of last entry stored */
71 /* List of all value objects currently allocated
72 (except for those released by calls to release_value)
73 This is so they can be freed after each command. */
75 static value_ptr all_values
;
77 /* Allocate a value that has the correct length for type TYPE. */
83 register value_ptr val
;
84 struct type
*atype
= check_typedef (type
);
86 val
= (struct value
*) xmalloc (sizeof (struct value
) + TYPE_LENGTH (atype
));
87 VALUE_NEXT (val
) = all_values
;
89 VALUE_TYPE (val
) = type
;
90 VALUE_ENCLOSING_TYPE (val
) = type
;
91 VALUE_LVAL (val
) = not_lval
;
92 VALUE_ADDRESS (val
) = 0;
93 VALUE_FRAME (val
) = 0;
94 VALUE_OFFSET (val
) = 0;
95 VALUE_BITPOS (val
) = 0;
96 VALUE_BITSIZE (val
) = 0;
97 VALUE_REGNO (val
) = -1;
99 VALUE_OPTIMIZED_OUT (val
) = 0;
100 VALUE_BFD_SECTION (val
) = NULL
;
101 VALUE_EMBEDDED_OFFSET (val
) = 0;
102 VALUE_POINTED_TO_OFFSET (val
) = 0;
107 /* Allocate a value that has the correct length
108 for COUNT repetitions type TYPE. */
111 allocate_repeat_value (type
, count
)
115 int low_bound
= current_language
->string_lower_bound
; /* ??? */
116 /* FIXME-type-allocation: need a way to free this type when we are
118 struct type
*range_type
119 = create_range_type ((struct type
*) NULL
, builtin_type_int
,
120 low_bound
, count
+ low_bound
- 1);
121 /* FIXME-type-allocation: need a way to free this type when we are
123 return allocate_value (create_array_type ((struct type
*) NULL
,
127 /* Return a mark in the value chain. All values allocated after the
128 mark is obtained (except for those released) are subject to being freed
129 if a subsequent value_free_to_mark is passed the mark. */
136 /* Free all values allocated since MARK was obtained by value_mark
137 (except for those released). */
139 value_free_to_mark (mark
)
144 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
146 next
= VALUE_NEXT (val
);
152 /* Free all the values that have been allocated (except for those released).
153 Called after each command, successful or not. */
158 register value_ptr val
, next
;
160 for (val
= all_values
; val
; val
= next
)
162 next
= VALUE_NEXT (val
);
169 /* Remove VAL from the chain all_values
170 so it will not be freed automatically. */
174 register value_ptr val
;
176 register value_ptr v
;
178 if (all_values
== val
)
180 all_values
= val
->next
;
184 for (v
= all_values
; v
; v
= v
->next
)
194 /* Release all values up to mark */
196 value_release_to_mark (mark
)
201 for (val
= next
= all_values
; next
; next
= VALUE_NEXT (next
))
202 if (VALUE_NEXT (next
) == mark
)
204 all_values
= VALUE_NEXT (next
);
205 VALUE_NEXT (next
) = 0;
212 /* Return a copy of the value ARG.
213 It contains the same contents, for same memory address,
214 but it's a different block of storage. */
220 register struct type
*encl_type
= VALUE_ENCLOSING_TYPE (arg
);
221 register value_ptr val
= allocate_value (encl_type
);
222 VALUE_TYPE (val
) = VALUE_TYPE (arg
);
223 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
224 VALUE_ADDRESS (val
) = VALUE_ADDRESS (arg
);
225 VALUE_OFFSET (val
) = VALUE_OFFSET (arg
);
226 VALUE_BITPOS (val
) = VALUE_BITPOS (arg
);
227 VALUE_BITSIZE (val
) = VALUE_BITSIZE (arg
);
228 VALUE_FRAME (val
) = VALUE_FRAME (arg
);
229 VALUE_REGNO (val
) = VALUE_REGNO (arg
);
230 VALUE_LAZY (val
) = VALUE_LAZY (arg
);
231 VALUE_OPTIMIZED_OUT (val
) = VALUE_OPTIMIZED_OUT (arg
);
232 VALUE_EMBEDDED_OFFSET (val
) = VALUE_EMBEDDED_OFFSET (arg
);
233 VALUE_POINTED_TO_OFFSET (val
) = VALUE_POINTED_TO_OFFSET (arg
);
234 VALUE_BFD_SECTION (val
) = VALUE_BFD_SECTION (arg
);
235 val
->modifiable
= arg
->modifiable
;
236 if (!VALUE_LAZY (val
))
238 memcpy (VALUE_CONTENTS_ALL_RAW (val
), VALUE_CONTENTS_ALL_RAW (arg
),
239 TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg
)));
245 /* Access to the value history. */
247 /* Record a new value in the value history.
248 Returns the absolute history index of the entry.
249 Result of -1 indicates the value was not saved; otherwise it is the
250 value history index of this new item. */
253 record_latest_value (val
)
258 /* We don't want this value to have anything to do with the inferior anymore.
259 In particular, "set $1 = 50" should not affect the variable from which
260 the value was taken, and fast watchpoints should be able to assume that
261 a value on the value history never changes. */
262 if (VALUE_LAZY (val
))
263 value_fetch_lazy (val
);
264 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
265 from. This is a bit dubious, because then *&$1 does not just return $1
266 but the current contents of that location. c'est la vie... */
270 /* Here we treat value_history_count as origin-zero
271 and applying to the value being stored now. */
273 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
276 register struct value_history_chunk
*new
277 = (struct value_history_chunk
*)
278 xmalloc (sizeof (struct value_history_chunk
));
279 memset (new->values
, 0, sizeof new->values
);
280 new->next
= value_history_chain
;
281 value_history_chain
= new;
284 value_history_chain
->values
[i
] = val
;
286 /* Now we regard value_history_count as origin-one
287 and applying to the value just stored. */
289 return ++value_history_count
;
292 /* Return a copy of the value in the history with sequence number NUM. */
295 access_value_history (num
)
298 register struct value_history_chunk
*chunk
;
300 register int absnum
= num
;
303 absnum
+= value_history_count
;
308 error ("The history is empty.");
310 error ("There is only one value in the history.");
312 error ("History does not go back to $$%d.", -num
);
314 if (absnum
> value_history_count
)
315 error ("History has not yet reached $%d.", absnum
);
319 /* Now absnum is always absolute and origin zero. */
321 chunk
= value_history_chain
;
322 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
- absnum
/ VALUE_HISTORY_CHUNK
;
326 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
329 /* Clear the value history entirely.
330 Must be done when new symbol tables are loaded,
331 because the type pointers become invalid. */
334 clear_value_history ()
336 register struct value_history_chunk
*next
;
338 register value_ptr val
;
340 while (value_history_chain
)
342 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
343 if ((val
= value_history_chain
->values
[i
]) != NULL
)
345 next
= value_history_chain
->next
;
346 free ((PTR
) value_history_chain
);
347 value_history_chain
= next
;
349 value_history_count
= 0;
353 show_values (num_exp
, from_tty
)
358 register value_ptr val
;
363 /* "info history +" should print from the stored position.
364 "info history <exp>" should print around value number <exp>. */
365 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
366 num
= parse_and_eval_address (num_exp
) - 5;
370 /* "info history" means print the last 10 values. */
371 num
= value_history_count
- 9;
377 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
379 val
= access_value_history (i
);
380 printf_filtered ("$%d = ", i
);
381 value_print (val
, gdb_stdout
, 0, Val_pretty_default
);
382 printf_filtered ("\n");
385 /* The next "info history +" should start after what we just printed. */
388 /* Hitting just return after this command should do the same thing as
389 "info history +". If num_exp is null, this is unnecessary, since
390 "info history +" is not useful after "info history". */
391 if (from_tty
&& num_exp
)
398 /* Internal variables. These are variables within the debugger
399 that hold values assigned by debugger commands.
400 The user refers to them with a '$' prefix
401 that does not appear in the variable names stored internally. */
403 static struct internalvar
*internalvars
;
405 /* Look up an internal variable with name NAME. NAME should not
406 normally include a dollar sign.
408 If the specified internal variable does not exist,
409 one is created, with a void value. */
412 lookup_internalvar (name
)
415 register struct internalvar
*var
;
417 for (var
= internalvars
; var
; var
= var
->next
)
418 if (STREQ (var
->name
, name
))
421 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
422 var
->name
= concat (name
, NULL
);
423 var
->value
= allocate_value (builtin_type_void
);
424 release_value (var
->value
);
425 var
->next
= internalvars
;
431 value_of_internalvar (var
)
432 struct internalvar
*var
;
434 register value_ptr val
;
436 #ifdef IS_TRAPPED_INTERNALVAR
437 if (IS_TRAPPED_INTERNALVAR (var
->name
))
438 return VALUE_OF_TRAPPED_INTERNALVAR (var
);
441 val
= value_copy (var
->value
);
442 if (VALUE_LAZY (val
))
443 value_fetch_lazy (val
);
444 VALUE_LVAL (val
) = lval_internalvar
;
445 VALUE_INTERNALVAR (val
) = var
;
450 set_internalvar_component (var
, offset
, bitpos
, bitsize
, newval
)
451 struct internalvar
*var
;
452 int offset
, bitpos
, bitsize
;
455 register char *addr
= VALUE_CONTENTS (var
->value
) + offset
;
457 #ifdef IS_TRAPPED_INTERNALVAR
458 if (IS_TRAPPED_INTERNALVAR (var
->name
))
459 SET_TRAPPED_INTERNALVAR (var
, newval
, bitpos
, bitsize
, offset
);
463 modify_field (addr
, value_as_long (newval
),
466 memcpy (addr
, VALUE_CONTENTS (newval
), TYPE_LENGTH (VALUE_TYPE (newval
)));
470 set_internalvar (var
, val
)
471 struct internalvar
*var
;
476 #ifdef IS_TRAPPED_INTERNALVAR
477 if (IS_TRAPPED_INTERNALVAR (var
->name
))
478 SET_TRAPPED_INTERNALVAR (var
, val
, 0, 0, 0);
481 newval
= value_copy (val
);
482 newval
->modifiable
= 1;
484 /* Force the value to be fetched from the target now, to avoid problems
485 later when this internalvar is referenced and the target is gone or
487 if (VALUE_LAZY (newval
))
488 value_fetch_lazy (newval
);
490 /* Begin code which must not call error(). If var->value points to
491 something free'd, an error() obviously leaves a dangling pointer.
492 But we also get a danling pointer if var->value points to
493 something in the value chain (i.e., before release_value is
494 called), because after the error free_all_values will get called before
496 free ((PTR
) var
->value
);
498 release_value (newval
);
499 /* End code which must not call error(). */
503 internalvar_name (var
)
504 struct internalvar
*var
;
509 /* Free all internalvars. Done when new symtabs are loaded,
510 because that makes the values invalid. */
513 clear_internalvars ()
515 register struct internalvar
*var
;
520 internalvars
= var
->next
;
521 free ((PTR
) var
->name
);
522 free ((PTR
) var
->value
);
528 show_convenience (ignore
, from_tty
)
532 register struct internalvar
*var
;
535 for (var
= internalvars
; var
; var
= var
->next
)
537 #ifdef IS_TRAPPED_INTERNALVAR
538 if (IS_TRAPPED_INTERNALVAR (var
->name
))
545 printf_filtered ("$%s = ", var
->name
);
546 value_print (var
->value
, gdb_stdout
, 0, Val_pretty_default
);
547 printf_filtered ("\n");
550 printf_unfiltered ("No debugger convenience variables now defined.\n\
551 Convenience variables have names starting with \"$\";\n\
552 use \"set\" as in \"set $foo = 5\" to define them.\n");
555 /* Extract a value as a C number (either long or double).
556 Knows how to convert fixed values to double, or
557 floating values to long.
558 Does not deallocate the value. */
562 register value_ptr val
;
564 /* This coerces arrays and functions, which is necessary (e.g.
565 in disassemble_command). It also dereferences references, which
566 I suspect is the most logical thing to do. */
568 return unpack_long (VALUE_TYPE (val
), VALUE_CONTENTS (val
));
572 value_as_double (val
)
573 register value_ptr val
;
578 foo
= unpack_double (VALUE_TYPE (val
), VALUE_CONTENTS (val
), &inv
);
580 error ("Invalid floating value found in program.");
583 /* Extract a value as a C pointer. Does not deallocate the value.
584 Note that val's type may not actually be a pointer; value_as_long
585 handles all the cases. */
587 value_as_pointer (val
)
590 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
591 whether we want this to be true eventually. */
593 /* ADDR_BITS_REMOVE is wrong if we are being called for a
594 non-address (e.g. argument to "signal", "info break", etc.), or
595 for pointers to char, in which the low bits *are* significant. */
596 return ADDR_BITS_REMOVE (value_as_long (val
));
598 return value_as_long (val
);
602 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
603 as a long, or as a double, assuming the raw data is described
604 by type TYPE. Knows how to convert different sizes of values
605 and can convert between fixed and floating point. We don't assume
606 any alignment for the raw data. Return value is in host byte order.
608 If you want functions and arrays to be coerced to pointers, and
609 references to be dereferenced, call value_as_long() instead.
611 C++: It is assumed that the front-end has taken care of
612 all matters concerning pointers to members. A pointer
613 to member which reaches here is considered to be equivalent
614 to an INT (or some size). After all, it is only an offset. */
617 unpack_long (type
, valaddr
)
621 register enum type_code code
= TYPE_CODE (type
);
622 register int len
= TYPE_LENGTH (type
);
623 register int nosign
= TYPE_UNSIGNED (type
);
625 if (current_language
->la_language
== language_scm
626 && is_scmvalue_type (type
))
627 return scm_unpack (type
, valaddr
, TYPE_CODE_INT
);
631 case TYPE_CODE_TYPEDEF
:
632 return unpack_long (check_typedef (type
), valaddr
);
637 case TYPE_CODE_RANGE
:
639 return extract_unsigned_integer (valaddr
, len
);
641 return extract_signed_integer (valaddr
, len
);
644 return extract_floating (valaddr
, len
);
648 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
649 whether we want this to be true eventually. */
650 if (GDB_TARGET_IS_D10V
652 return D10V_MAKE_DADDR (extract_address (valaddr
, len
));
653 return extract_typed_address (valaddr
, type
);
655 case TYPE_CODE_MEMBER
:
656 error ("not implemented: member types in unpack_long");
659 error ("Value can't be converted to integer.");
661 return 0; /* Placate lint. */
664 /* Return a double value from the specified type and address.
665 INVP points to an int which is set to 0 for valid value,
666 1 for invalid value (bad float format). In either case,
667 the returned double is OK to use. Argument is in target
668 format, result is in host format. */
671 unpack_double (type
, valaddr
, invp
)
680 *invp
= 0; /* Assume valid. */
681 CHECK_TYPEDEF (type
);
682 code
= TYPE_CODE (type
);
683 len
= TYPE_LENGTH (type
);
684 nosign
= TYPE_UNSIGNED (type
);
685 if (code
== TYPE_CODE_FLT
)
688 if (INVALID_FLOAT (valaddr
, len
))
691 return 1.234567891011121314;
694 return extract_floating (valaddr
, len
);
698 /* Unsigned -- be sure we compensate for signed LONGEST. */
699 #if !defined (_MSC_VER) || (_MSC_VER > 900)
700 return (ULONGEST
) unpack_long (type
, valaddr
);
702 /* FIXME!!! msvc22 doesn't support unsigned __int64 -> double */
703 return (LONGEST
) unpack_long (type
, valaddr
);
704 #endif /* _MSC_VER */
708 /* Signed -- we are OK with unpack_long. */
709 return unpack_long (type
, valaddr
);
713 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
714 as a CORE_ADDR, assuming the raw data is described by type TYPE.
715 We don't assume any alignment for the raw data. Return value is in
718 If you want functions and arrays to be coerced to pointers, and
719 references to be dereferenced, call value_as_pointer() instead.
721 C++: It is assumed that the front-end has taken care of
722 all matters concerning pointers to members. A pointer
723 to member which reaches here is considered to be equivalent
724 to an INT (or some size). After all, it is only an offset. */
727 unpack_pointer (type
, valaddr
)
731 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
732 whether we want this to be true eventually. */
733 return unpack_long (type
, valaddr
);
737 /* Get the value of the FIELDN'th field (which must be static) of TYPE. */
740 value_static_field (type
, fieldno
)
746 if (TYPE_FIELD_STATIC_HAS_ADDR (type
, fieldno
))
748 addr
= TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
);
753 char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
754 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_NAMESPACE
, 0, NULL
);
757 /* With some compilers, e.g. HP aCC, static data members are reported
758 as non-debuggable symbols */
759 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
, NULL
, NULL
);
764 addr
= SYMBOL_VALUE_ADDRESS (msym
);
765 sect
= SYMBOL_BFD_SECTION (msym
);
770 addr
= SYMBOL_VALUE_ADDRESS (sym
);
771 sect
= SYMBOL_BFD_SECTION (sym
);
773 SET_FIELD_PHYSADDR (TYPE_FIELD (type
, fieldno
), addr
);
775 return value_at (TYPE_FIELD_TYPE (type
, fieldno
), addr
, sect
);
778 /* Given a value ARG1 (offset by OFFSET bytes)
779 of a struct or union type ARG_TYPE,
780 extract and return the value of one of its (non-static) fields.
781 FIELDNO says which field. */
784 value_primitive_field (arg1
, offset
, fieldno
, arg_type
)
785 register value_ptr arg1
;
787 register int fieldno
;
788 register struct type
*arg_type
;
790 register value_ptr v
;
791 register struct type
*type
;
793 CHECK_TYPEDEF (arg_type
);
794 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
796 /* Handle packed fields */
798 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
800 v
= value_from_longest (type
,
801 unpack_field_as_long (arg_type
,
802 VALUE_CONTENTS (arg1
)
805 VALUE_BITPOS (v
) = TYPE_FIELD_BITPOS (arg_type
, fieldno
) % 8;
806 VALUE_BITSIZE (v
) = TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
807 VALUE_OFFSET (v
) = VALUE_OFFSET (arg1
) + offset
808 + TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
810 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
812 /* This field is actually a base subobject, so preserve the
813 entire object's contents for later references to virtual
815 v
= allocate_value (VALUE_ENCLOSING_TYPE (arg1
));
816 VALUE_TYPE (v
) = arg_type
;
817 if (VALUE_LAZY (arg1
))
820 memcpy (VALUE_CONTENTS_ALL_RAW (v
), VALUE_CONTENTS_ALL_RAW (arg1
),
821 TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg1
)));
822 VALUE_OFFSET (v
) = VALUE_OFFSET (arg1
);
823 VALUE_EMBEDDED_OFFSET (v
)
825 VALUE_EMBEDDED_OFFSET (arg1
) +
826 TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
830 /* Plain old data member */
831 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
832 v
= allocate_value (type
);
833 if (VALUE_LAZY (arg1
))
836 memcpy (VALUE_CONTENTS_RAW (v
),
837 VALUE_CONTENTS_RAW (arg1
) + offset
,
839 VALUE_OFFSET (v
) = VALUE_OFFSET (arg1
) + offset
;
841 VALUE_LVAL (v
) = VALUE_LVAL (arg1
);
842 if (VALUE_LVAL (arg1
) == lval_internalvar
)
843 VALUE_LVAL (v
) = lval_internalvar_component
;
844 VALUE_ADDRESS (v
) = VALUE_ADDRESS (arg1
);
845 /* VALUE_OFFSET (v) = VALUE_OFFSET (arg1) + offset
846 + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8; */
850 /* Given a value ARG1 of a struct or union type,
851 extract and return the value of one of its (non-static) fields.
852 FIELDNO says which field. */
855 value_field (arg1
, fieldno
)
856 register value_ptr arg1
;
857 register int fieldno
;
859 return value_primitive_field (arg1
, 0, fieldno
, VALUE_TYPE (arg1
));
862 /* Return a non-virtual function as a value.
863 F is the list of member functions which contains the desired method.
864 J is an index into F which provides the desired method. */
867 value_fn_field (arg1p
, f
, j
, type
, offset
)
874 register value_ptr v
;
875 register struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
878 sym
= lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f
, j
),
879 0, VAR_NAMESPACE
, 0, NULL
);
883 error ("Internal error: could not find physical method named %s",
884 TYPE_FN_FIELD_PHYSNAME (f, j));
887 v
= allocate_value (ftype
);
888 VALUE_ADDRESS (v
) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym
));
889 VALUE_TYPE (v
) = ftype
;
893 if (type
!= VALUE_TYPE (*arg1p
))
894 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
895 value_addr (*arg1p
)));
897 /* Move the `this' pointer according to the offset.
898 VALUE_OFFSET (*arg1p) += offset;
905 /* Return a virtual function as a value.
906 ARG1 is the object which provides the virtual function
907 table pointer. *ARG1P is side-effected in calling this function.
908 F is the list of member functions which contains the desired virtual
910 J is an index into F which provides the desired virtual function.
912 TYPE is the type in which F is located. */
914 value_virtual_fn_field (arg1p
, f
, j
, type
, offset
)
921 value_ptr arg1
= *arg1p
;
922 struct type
*type1
= check_typedef (VALUE_TYPE (arg1
));
924 if (TYPE_HAS_VTABLE (type
))
926 /* Deal with HP/Taligent runtime model for virtual functions */
928 value_ptr argp
; /* arg1 cast to base */
929 CORE_ADDR coreptr
; /* pointer to target address */
930 int class_index
; /* which class segment pointer to use */
931 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
); /* method type */
933 argp
= value_cast (type
, *arg1p
);
935 if (VALUE_ADDRESS (argp
) == 0)
936 error ("Address of object is null; object may not have been created.");
938 /* pai: FIXME -- 32x64 possible problem? */
939 /* First word (4 bytes) in object layout is the vtable pointer */
940 coreptr
= *(CORE_ADDR
*) (VALUE_CONTENTS (argp
)); /* pai: (temp) */
941 /* + offset + VALUE_EMBEDDED_OFFSET (argp)); */
944 error ("Virtual table pointer is null for object; object may not have been created.");
947 * FIXME: The code here currently handles only
948 * the non-RRBC case of the Taligent/HP runtime spec; when RRBC
949 * is introduced, the condition for the "if" below will have to
950 * be changed to be a test for the RRBC case. */
954 /* Non-RRBC case; the virtual function pointers are stored at fixed
955 * offsets in the virtual table. */
957 /* Retrieve the offset in the virtual table from the debug
958 * info. The offset of the vfunc's entry is in words from
959 * the beginning of the vtable; but first we have to adjust
960 * by HP_ACC_VFUNC_START to account for other entries */
962 /* pai: FIXME: 32x64 problem here, a word may be 8 bytes in
963 * which case the multiplier should be 8 and values should be long */
964 vp
= value_at (builtin_type_int
,
965 coreptr
+ 4 * (TYPE_FN_FIELD_VOFFSET (f
, j
) + HP_ACC_VFUNC_START
), NULL
);
967 coreptr
= *(CORE_ADDR
*) (VALUE_CONTENTS (vp
));
968 /* coreptr now contains the address of the virtual function */
969 /* (Actually, it contains the pointer to the plabel for the function. */
973 /* RRBC case; the virtual function pointers are found by double
974 * indirection through the class segment tables. */
976 /* Choose class segment depending on type we were passed */
977 class_index
= class_index_in_primary_list (type
);
979 /* Find class segment pointer. These are in the vtable slots after
980 * some other entries, so adjust by HP_ACC_VFUNC_START for that. */
981 /* pai: FIXME 32x64 problem here, if words are 8 bytes long
982 * the multiplier below has to be 8 and value should be long. */
983 vp
= value_at (builtin_type_int
,
984 coreptr
+ 4 * (HP_ACC_VFUNC_START
+ class_index
), NULL
);
985 /* Indirect once more, offset by function index */
986 /* pai: FIXME 32x64 problem here, again multiplier could be 8 and value long */
987 coreptr
= *(CORE_ADDR
*) (VALUE_CONTENTS (vp
) + 4 * TYPE_FN_FIELD_VOFFSET (f
, j
));
988 vp
= value_at (builtin_type_int
, coreptr
, NULL
);
989 coreptr
= *(CORE_ADDR
*) (VALUE_CONTENTS (vp
));
991 /* coreptr now contains the address of the virtual function */
992 /* (Actually, it contains the pointer to the plabel for the function.) */
997 error ("Address of virtual function is null; error in virtual table?");
999 /* Wrap this addr in a value and return pointer */
1000 vp
= allocate_value (ftype
);
1001 VALUE_TYPE (vp
) = ftype
;
1002 VALUE_ADDRESS (vp
) = coreptr
;
1004 /* pai: (temp) do we need the value_ind stuff in value_fn_field? */
1008 { /* Not using HP/Taligent runtime conventions; so try to
1009 * use g++ conventions for virtual table */
1011 struct type
*entry_type
;
1012 /* First, get the virtual function table pointer. That comes
1013 with a strange type, so cast it to type `pointer to long' (which
1014 should serve just fine as a function type). Then, index into
1015 the table, and convert final value to appropriate function type. */
1016 value_ptr entry
, vfn
, vtbl
;
1017 value_ptr vi
= value_from_longest (builtin_type_int
,
1018 (LONGEST
) TYPE_FN_FIELD_VOFFSET (f
, j
));
1019 struct type
*fcontext
= TYPE_FN_FIELD_FCONTEXT (f
, j
);
1020 struct type
*context
;
1021 if (fcontext
== NULL
)
1022 /* We don't have an fcontext (e.g. the program was compiled with
1023 g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE.
1024 This won't work right for multiple inheritance, but at least we
1025 should do as well as GDB 3.x did. */
1026 fcontext
= TYPE_VPTR_BASETYPE (type
);
1027 context
= lookup_pointer_type (fcontext
);
1028 /* Now context is a pointer to the basetype containing the vtbl. */
1029 if (TYPE_TARGET_TYPE (context
) != type1
)
1031 value_ptr tmp
= value_cast (context
, value_addr (arg1
));
1032 VALUE_POINTED_TO_OFFSET (tmp
) = 0;
1033 arg1
= value_ind (tmp
);
1034 type1
= check_typedef (VALUE_TYPE (arg1
));
1038 /* Now context is the basetype containing the vtbl. */
1040 /* This type may have been defined before its virtual function table
1041 was. If so, fill in the virtual function table entry for the
1043 if (TYPE_VPTR_FIELDNO (context
) < 0)
1044 fill_in_vptr_fieldno (context
);
1046 /* The virtual function table is now an array of structures
1047 which have the form { int16 offset, delta; void *pfn; }. */
1048 vtbl
= value_primitive_field (arg1
, 0, TYPE_VPTR_FIELDNO (context
),
1049 TYPE_VPTR_BASETYPE (context
));
1051 /* With older versions of g++, the vtbl field pointed to an array
1052 of structures. Nowadays it points directly to the structure. */
1053 if (TYPE_CODE (VALUE_TYPE (vtbl
)) == TYPE_CODE_PTR
1054 && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl
))) == TYPE_CODE_ARRAY
)
1056 /* Handle the case where the vtbl field points to an
1057 array of structures. */
1058 vtbl
= value_ind (vtbl
);
1060 /* Index into the virtual function table. This is hard-coded because
1061 looking up a field is not cheap, and it may be important to save
1062 time, e.g. if the user has set a conditional breakpoint calling
1063 a virtual function. */
1064 entry
= value_subscript (vtbl
, vi
);
1068 /* Handle the case where the vtbl field points directly to a structure. */
1069 vtbl
= value_add (vtbl
, vi
);
1070 entry
= value_ind (vtbl
);
1073 entry_type
= check_typedef (VALUE_TYPE (entry
));
1075 if (TYPE_CODE (entry_type
) == TYPE_CODE_STRUCT
)
1077 /* Move the `this' pointer according to the virtual function table. */
1078 VALUE_OFFSET (arg1
) += value_as_long (value_field (entry
, 0));
1080 if (!VALUE_LAZY (arg1
))
1082 VALUE_LAZY (arg1
) = 1;
1083 value_fetch_lazy (arg1
);
1086 vfn
= value_field (entry
, 2);
1088 else if (TYPE_CODE (entry_type
) == TYPE_CODE_PTR
)
1091 error ("I'm confused: virtual function table has bad type");
1092 /* Reinstantiate the function pointer with the correct type. */
1093 VALUE_TYPE (vfn
) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f
, j
));
1100 /* ARG is a pointer to an object we know to be at least
1101 a DTYPE. BTYPE is the most derived basetype that has
1102 already been searched (and need not be searched again).
1103 After looking at the vtables between BTYPE and DTYPE,
1104 return the most derived type we find. The caller must
1105 be satisfied when the return value == DTYPE.
1107 FIXME-tiemann: should work with dossier entries as well.
1108 NOTICE - djb: I see no good reason at all to keep this function now that
1109 we have RTTI support. It's used in literally one place, and it's
1110 hard to keep this function up to date when it's purpose is served
1111 by value_rtti_type efficiently.
1112 Consider it gone for 5.1. */
1115 value_headof (in_arg
, btype
, dtype
)
1117 struct type
*btype
, *dtype
;
1119 /* First collect the vtables we must look at for this object. */
1120 value_ptr arg
, vtbl
;
1122 char *demangled_name
;
1123 struct minimal_symbol
*msymbol
;
1125 btype
= TYPE_VPTR_BASETYPE (dtype
);
1126 CHECK_TYPEDEF (btype
);
1129 arg
= value_cast (lookup_pointer_type (btype
), arg
);
1130 if (TYPE_CODE (VALUE_TYPE (arg
)) == TYPE_CODE_REF
)
1133 * Copy the value, but change the type from (T&) to (T*).
1134 * We keep the same location information, which is efficient,
1135 * and allows &(&X) to get the location containing the reference.
1137 arg
= value_copy (arg
);
1138 VALUE_TYPE (arg
) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg
)));
1140 if (VALUE_ADDRESS(value_field (value_ind(arg
), TYPE_VPTR_FIELDNO (btype
)))==0)
1143 vtbl
= value_ind (value_field (value_ind (arg
), TYPE_VPTR_FIELDNO (btype
)));
1144 /* Turn vtable into typeinfo function */
1145 VALUE_OFFSET(vtbl
)+=4;
1147 msymbol
= lookup_minimal_symbol_by_pc ( value_as_pointer(value_ind(vtbl
)) );
1149 || (demangled_name
= SYMBOL_NAME (msymbol
)) == NULL
)
1151 /* If we expected to find a vtable, but did not, let the user
1152 know that we aren't happy, but don't throw an error.
1153 FIXME: there has to be a better way to do this. */
1154 struct type
*error_type
= (struct type
*) xmalloc (sizeof (struct type
));
1155 memcpy (error_type
, VALUE_TYPE (in_arg
), sizeof (struct type
));
1156 TYPE_NAME (error_type
) = savestring ("suspicious *", sizeof ("suspicious *"));
1157 VALUE_TYPE (in_arg
) = error_type
;
1160 demangled_name
= cplus_demangle(demangled_name
,DMGL_ANSI
);
1161 *(strchr (demangled_name
, ' ')) = '\0';
1163 sym
= lookup_symbol (demangled_name
, 0, VAR_NAMESPACE
, 0, 0);
1165 error ("could not find type declaration for `%s'", demangled_name
);
1168 VALUE_TYPE (arg
) = lookup_pointer_type (SYMBOL_TYPE (sym
));
1172 /* ARG is a pointer object of type TYPE. If TYPE has virtual
1173 function tables, probe ARG's tables (including the vtables
1174 of its baseclasses) to figure out the most derived type that ARG
1175 could actually be a pointer to. */
1178 value_from_vtable_info (arg
, type
)
1182 /* Take care of preliminaries. */
1183 if (TYPE_VPTR_FIELDNO (type
) < 0)
1184 fill_in_vptr_fieldno (type
);
1185 if (TYPE_VPTR_FIELDNO (type
) < 0)
1188 return value_headof (arg
, 0, type
);
1191 /* Return true if the INDEXth field of TYPE is a virtual baseclass
1192 pointer which is for the base class whose type is BASECLASS. */
1195 vb_match (type
, index
, basetype
)
1198 struct type
*basetype
;
1200 struct type
*fieldtype
;
1201 char *name
= TYPE_FIELD_NAME (type
, index
);
1202 char *field_class_name
= NULL
;
1206 /* gcc 2.4 uses _vb$. */
1207 if (name
[1] == 'v' && name
[2] == 'b' && is_cplus_marker (name
[3]))
1208 field_class_name
= name
+ 4;
1209 /* gcc 2.5 will use __vb_. */
1210 if (name
[1] == '_' && name
[2] == 'v' && name
[3] == 'b' && name
[4] == '_')
1211 field_class_name
= name
+ 5;
1213 if (field_class_name
== NULL
)
1214 /* This field is not a virtual base class pointer. */
1217 /* It's a virtual baseclass pointer, now we just need to find out whether
1218 it is for this baseclass. */
1219 fieldtype
= TYPE_FIELD_TYPE (type
, index
);
1220 if (fieldtype
== NULL
1221 || TYPE_CODE (fieldtype
) != TYPE_CODE_PTR
)
1222 /* "Can't happen". */
1225 /* What we check for is that either the types are equal (needed for
1226 nameless types) or have the same name. This is ugly, and a more
1227 elegant solution should be devised (which would probably just push
1228 the ugliness into symbol reading unless we change the stabs format). */
1229 if (TYPE_TARGET_TYPE (fieldtype
) == basetype
)
1232 if (TYPE_NAME (basetype
) != NULL
1233 && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype
)) != NULL
1234 && STREQ (TYPE_NAME (basetype
),
1235 TYPE_NAME (TYPE_TARGET_TYPE (fieldtype
))))
1240 /* Compute the offset of the baseclass which is
1241 the INDEXth baseclass of class TYPE,
1242 for value at VALADDR (in host) at ADDRESS (in target).
1243 The result is the offset of the baseclass value relative
1244 to (the address of)(ARG) + OFFSET.
1246 -1 is returned on error. */
1249 baseclass_offset (type
, index
, valaddr
, address
)
1255 struct type
*basetype
= TYPE_BASECLASS (type
, index
);
1257 if (BASETYPE_VIA_VIRTUAL (type
, index
))
1259 /* Must hunt for the pointer to this virtual baseclass. */
1260 register int i
, len
= TYPE_NFIELDS (type
);
1261 register int n_baseclasses
= TYPE_N_BASECLASSES (type
);
1263 /* First look for the virtual baseclass pointer
1265 for (i
= n_baseclasses
; i
< len
; i
++)
1267 if (vb_match (type
, i
, basetype
))
1270 = unpack_pointer (TYPE_FIELD_TYPE (type
, i
),
1271 valaddr
+ (TYPE_FIELD_BITPOS (type
, i
) / 8));
1273 return addr
- (LONGEST
) address
;
1276 /* Not in the fields, so try looking through the baseclasses. */
1277 for (i
= index
+ 1; i
< n_baseclasses
; i
++)
1280 baseclass_offset (type
, i
, valaddr
, address
);
1288 /* Baseclass is easily computed. */
1289 return TYPE_BASECLASS_BITPOS (type
, index
) / 8;
1292 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
1295 Extracting bits depends on endianness of the machine. Compute the
1296 number of least significant bits to discard. For big endian machines,
1297 we compute the total number of bits in the anonymous object, subtract
1298 off the bit count from the MSB of the object to the MSB of the
1299 bitfield, then the size of the bitfield, which leaves the LSB discard
1300 count. For little endian machines, the discard count is simply the
1301 number of bits from the LSB of the anonymous object to the LSB of the
1304 If the field is signed, we also do sign extension. */
1307 unpack_field_as_long (type
, valaddr
, fieldno
)
1314 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
1315 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
1317 struct type
*field_type
;
1319 val
= extract_unsigned_integer (valaddr
+ bitpos
/ 8, sizeof (val
));
1320 field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
1321 CHECK_TYPEDEF (field_type
);
1323 /* Extract bits. See comment above. */
1325 if (BITS_BIG_ENDIAN
)
1326 lsbcount
= (sizeof val
* 8 - bitpos
% 8 - bitsize
);
1328 lsbcount
= (bitpos
% 8);
1331 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
1332 If the field is signed, and is negative, then sign extend. */
1334 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
1336 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
1338 if (!TYPE_UNSIGNED (field_type
))
1340 if (val
& (valmask
^ (valmask
>> 1)))
1349 /* Modify the value of a bitfield. ADDR points to a block of memory in
1350 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
1351 is the desired value of the field, in host byte order. BITPOS and BITSIZE
1352 indicate which bits (in target bit order) comprise the bitfield. */
1355 modify_field (addr
, fieldval
, bitpos
, bitsize
)
1358 int bitpos
, bitsize
;
1362 /* If a negative fieldval fits in the field in question, chop
1363 off the sign extension bits. */
1364 if (bitsize
< (8 * (int) sizeof (fieldval
))
1365 && (~fieldval
& ~((1 << (bitsize
- 1)) - 1)) == 0)
1366 fieldval
= fieldval
& ((1 << bitsize
) - 1);
1368 /* Warn if value is too big to fit in the field in question. */
1369 if (bitsize
< (8 * (int) sizeof (fieldval
))
1370 && 0 != (fieldval
& ~((1 << bitsize
) - 1)))
1372 /* FIXME: would like to include fieldval in the message, but
1373 we don't have a sprintf_longest. */
1374 warning ("Value does not fit in %d bits.", bitsize
);
1376 /* Truncate it, otherwise adjoining fields may be corrupted. */
1377 fieldval
= fieldval
& ((1 << bitsize
) - 1);
1380 oword
= extract_signed_integer (addr
, sizeof oword
);
1382 /* Shifting for bit field depends on endianness of the target machine. */
1383 if (BITS_BIG_ENDIAN
)
1384 bitpos
= sizeof (oword
) * 8 - bitpos
- bitsize
;
1386 /* Mask out old value, while avoiding shifts >= size of oword */
1387 if (bitsize
< 8 * (int) sizeof (oword
))
1388 oword
&= ~(((((ULONGEST
) 1) << bitsize
) - 1) << bitpos
);
1390 oword
&= ~((~(ULONGEST
) 0) << bitpos
);
1391 oword
|= fieldval
<< bitpos
;
1393 store_signed_integer (addr
, sizeof oword
, oword
);
1396 /* Convert C numbers into newly allocated values */
1399 value_from_longest (type
, num
)
1401 register LONGEST num
;
1403 register value_ptr val
= allocate_value (type
);
1404 register enum type_code code
;
1407 code
= TYPE_CODE (type
);
1408 len
= TYPE_LENGTH (type
);
1412 case TYPE_CODE_TYPEDEF
:
1413 type
= check_typedef (type
);
1416 case TYPE_CODE_CHAR
:
1417 case TYPE_CODE_ENUM
:
1418 case TYPE_CODE_BOOL
:
1419 case TYPE_CODE_RANGE
:
1420 store_signed_integer (VALUE_CONTENTS_RAW (val
), len
, num
);
1425 store_typed_address (VALUE_CONTENTS_RAW (val
), type
, (CORE_ADDR
) num
);
1429 error ("Unexpected type (%d) encountered for integer constant.", code
);
1435 /* Create a value representing a pointer of type TYPE to the address
1438 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
1440 value_ptr val
= allocate_value (type
);
1441 store_typed_address (VALUE_CONTENTS_RAW (val
), type
, addr
);
1446 /* Create a value for a string constant to be stored locally
1447 (not in the inferior's memory space, but in GDB memory).
1448 This is analogous to value_from_longest, which also does not
1449 use inferior memory. String shall NOT contain embedded nulls. */
1452 value_from_string (ptr
)
1456 int len
= strlen (ptr
);
1457 int lowbound
= current_language
->string_lower_bound
;
1458 struct type
*rangetype
=
1459 create_range_type ((struct type
*) NULL
,
1461 lowbound
, len
+ lowbound
- 1);
1462 struct type
*stringtype
=
1463 create_array_type ((struct type
*) NULL
,
1464 *current_language
->string_char_type
,
1467 val
= allocate_value (stringtype
);
1468 memcpy (VALUE_CONTENTS_RAW (val
), ptr
, len
);
1473 value_from_double (type
, num
)
1477 register value_ptr val
= allocate_value (type
);
1478 struct type
*base_type
= check_typedef (type
);
1479 register enum type_code code
= TYPE_CODE (base_type
);
1480 register int len
= TYPE_LENGTH (base_type
);
1482 if (code
== TYPE_CODE_FLT
)
1484 store_floating (VALUE_CONTENTS_RAW (val
), len
, num
);
1487 error ("Unexpected type encountered for floating constant.");
1492 /* Deal with the value that is "about to be returned". */
1494 /* Return the value that a function returning now
1495 would be returning to its caller, assuming its type is VALTYPE.
1496 RETBUF is where we look for what ought to be the contents
1497 of the registers (in raw form). This is because it is often
1498 desirable to restore old values to those registers
1499 after saving the contents of interest, and then call
1500 this function using the saved values.
1501 struct_return is non-zero when the function in question is
1502 using the structure return conventions on the machine in question;
1503 0 when it is using the value returning conventions (this often
1504 means returning pointer to where structure is vs. returning value). */
1507 value_being_returned (valtype
, retbuf
, struct_return
)
1508 register struct type
*valtype
;
1513 register value_ptr val
;
1516 /* If this is not defined, just use EXTRACT_RETURN_VALUE instead. */
1517 if (EXTRACT_STRUCT_VALUE_ADDRESS_P
)
1520 addr
= EXTRACT_STRUCT_VALUE_ADDRESS (retbuf
);
1522 error ("Function return value unknown");
1523 return value_at (valtype
, addr
, NULL
);
1526 val
= allocate_value (valtype
);
1527 CHECK_TYPEDEF (valtype
);
1528 EXTRACT_RETURN_VALUE (valtype
, retbuf
, VALUE_CONTENTS_RAW (val
));
1533 /* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
1534 EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc
1535 and TYPE is the type (which is known to be struct, union or array).
1537 On most machines, the struct convention is used unless we are
1538 using gcc and the type is of a special size. */
1539 /* As of about 31 Mar 93, GCC was changed to be compatible with the
1540 native compiler. GCC 2.3.3 was the last release that did it the
1541 old way. Since gcc2_compiled was not changed, we have no
1542 way to correctly win in all cases, so we just do the right thing
1543 for gcc1 and for gcc2 after this change. Thus it loses for gcc
1544 2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled
1545 would cause more chaos than dealing with some struct returns being
1549 generic_use_struct_convention (gcc_p
, value_type
)
1551 struct type
*value_type
;
1553 return !((gcc_p
== 1)
1554 && (TYPE_LENGTH (value_type
) == 1
1555 || TYPE_LENGTH (value_type
) == 2
1556 || TYPE_LENGTH (value_type
) == 4
1557 || TYPE_LENGTH (value_type
) == 8));
1560 #ifndef USE_STRUCT_CONVENTION
1561 #define USE_STRUCT_CONVENTION(gcc_p,type) generic_use_struct_convention (gcc_p, type)
1565 /* Return true if the function specified is using the structure returning
1566 convention on this machine to return arguments, or 0 if it is using
1567 the value returning convention. FUNCTION is the value representing
1568 the function, FUNCADDR is the address of the function, and VALUE_TYPE
1569 is the type returned by the function. GCC_P is nonzero if compiled
1573 using_struct_return (function
, funcaddr
, value_type
, gcc_p
)
1576 struct type
*value_type
;
1580 register enum type_code code
= TYPE_CODE (value_type
);
1582 if (code
== TYPE_CODE_ERROR
)
1583 error ("Function return type unknown.");
1585 if (code
== TYPE_CODE_STRUCT
1586 || code
== TYPE_CODE_UNION
1587 || code
== TYPE_CODE_ARRAY
1588 || RETURN_VALUE_ON_STACK (value_type
))
1589 return USE_STRUCT_CONVENTION (gcc_p
, value_type
);
1594 /* Store VAL so it will be returned if a function returns now.
1595 Does not verify that VAL's type matches what the current
1596 function wants to return. */
1599 set_return_value (val
)
1602 struct type
*type
= check_typedef (VALUE_TYPE (val
));
1603 register enum type_code code
= TYPE_CODE (type
);
1605 if (code
== TYPE_CODE_ERROR
)
1606 error ("Function return type unknown.");
1608 if (code
== TYPE_CODE_STRUCT
1609 || code
== TYPE_CODE_UNION
) /* FIXME, implement struct return. */
1610 error ("GDB does not support specifying a struct or union return value.");
1612 STORE_RETURN_VALUE (type
, VALUE_CONTENTS (val
));
1616 _initialize_values ()
1618 add_cmd ("convenience", no_class
, show_convenience
,
1619 "Debugger convenience (\"$foo\") variables.\n\
1620 These variables are created when you assign them values;\n\
1621 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\n\
1622 A few convenience variables are given values automatically:\n\
1623 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
1624 \"$__\" holds the contents of the last address examined with \"x\".",
1627 add_cmd ("values", no_class
, show_values
,
1628 "Elements of value history around item number IDX (or last ten).",