1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5 2009, 2010, 2011 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 "arch-utils.h"
24 #include "gdb_string.h"
35 #include "gdb_assert.h"
41 #include "cli/cli-decode.h"
42 #include "exceptions.h"
43 #include "python/python.h"
45 #include "tracepoint.h"
47 /* Prototypes for exported functions. */
49 void _initialize_values (void);
51 /* Definition of a user function. */
52 struct internal_function
54 /* The name of the function. It is a bit odd to have this in the
55 function itself -- the user might use a differently-named
56 convenience variable to hold the function. */
60 internal_function_fn handler
;
62 /* User data for the handler. */
66 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
70 /* Lowest offset in the range. */
73 /* Length of the range. */
77 typedef struct range range_s
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (int offset1
, int len1
,
86 int offset2
, int len2
)
90 l
= max (offset1
, offset2
);
91 h
= min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if the first argument is strictly less than the
96 second, useful for VEC_lower_bound. We keep ranges sorted by
97 offset and coalesce overlapping and contiguous ranges, so this just
98 compares the starting offset. */
101 range_lessthan (const range_s
*r1
, const range_s
*r2
)
103 return r1
->offset
< r2
->offset
;
106 /* Returns true if RANGES contains any range that overlaps [OFFSET,
110 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
115 what
.offset
= offset
;
116 what
.length
= length
;
118 /* We keep ranges sorted by offset and coalesce overlapping and
119 contiguous ranges, so to check if a range list contains a given
120 range, we can do a binary search for the position the given range
121 would be inserted if we only considered the starting OFFSET of
122 ranges. We call that position I. Since we also have LENGTH to
123 care for (this is a range afterall), we need to check if the
124 _previous_ range overlaps the I range. E.g.,
128 |---| |---| |------| ... |--|
133 In the case above, the binary search would return `I=1', meaning,
134 this OFFSET should be inserted at position 1, and the current
135 position 1 should be pushed further (and before 2). But, `0'
138 Then we need to check if the I range overlaps the I range itself.
143 |---| |---| |-------| ... |--|
149 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
153 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
155 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
159 if (i
< VEC_length (range_s
, ranges
))
161 struct range
*r
= VEC_index (range_s
, ranges
, i
);
163 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
170 static struct cmd_list_element
*functionlist
;
174 /* Type of value; either not an lval, or one of the various
175 different possible kinds of lval. */
178 /* Is it modifiable? Only relevant if lval != not_lval. */
181 /* Location of value (if lval). */
184 /* If lval == lval_memory, this is the address in the inferior.
185 If lval == lval_register, this is the byte offset into the
186 registers structure. */
189 /* Pointer to internal variable. */
190 struct internalvar
*internalvar
;
192 /* If lval == lval_computed, this is a set of function pointers
193 to use to access and describe the value, and a closure pointer
197 struct lval_funcs
*funcs
; /* Functions to call. */
198 void *closure
; /* Closure for those functions to use. */
202 /* Describes offset of a value within lval of a structure in bytes.
203 If lval == lval_memory, this is an offset to the address. If
204 lval == lval_register, this is a further offset from
205 location.address within the registers structure. Note also the
206 member embedded_offset below. */
209 /* Only used for bitfields; number of bits contained in them. */
212 /* Only used for bitfields; position of start of field. For
213 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
214 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
217 /* Only used for bitfields; the containing value. This allows a
218 single read from the target when displaying multiple
220 struct value
*parent
;
222 /* Frame register value is relative to. This will be described in
223 the lval enum above as "lval_register". */
224 struct frame_id frame_id
;
226 /* Type of the value. */
229 /* If a value represents a C++ object, then the `type' field gives
230 the object's compile-time type. If the object actually belongs
231 to some class derived from `type', perhaps with other base
232 classes and additional members, then `type' is just a subobject
233 of the real thing, and the full object is probably larger than
234 `type' would suggest.
236 If `type' is a dynamic class (i.e. one with a vtable), then GDB
237 can actually determine the object's run-time type by looking at
238 the run-time type information in the vtable. When this
239 information is available, we may elect to read in the entire
240 object, for several reasons:
242 - When printing the value, the user would probably rather see the
243 full object, not just the limited portion apparent from the
246 - If `type' has virtual base classes, then even printing `type'
247 alone may require reaching outside the `type' portion of the
248 object to wherever the virtual base class has been stored.
250 When we store the entire object, `enclosing_type' is the run-time
251 type -- the complete object -- and `embedded_offset' is the
252 offset of `type' within that larger type, in bytes. The
253 value_contents() macro takes `embedded_offset' into account, so
254 most GDB code continues to see the `type' portion of the value,
255 just as the inferior would.
257 If `type' is a pointer to an object, then `enclosing_type' is a
258 pointer to the object's run-time type, and `pointed_to_offset' is
259 the offset in bytes from the full object to the pointed-to object
260 -- that is, the value `embedded_offset' would have if we followed
261 the pointer and fetched the complete object. (I don't really see
262 the point. Why not just determine the run-time type when you
263 indirect, and avoid the special case? The contents don't matter
264 until you indirect anyway.)
266 If we're not doing anything fancy, `enclosing_type' is equal to
267 `type', and `embedded_offset' is zero, so everything works
269 struct type
*enclosing_type
;
271 int pointed_to_offset
;
273 /* Values are stored in a chain, so that they can be deleted easily
274 over calls to the inferior. Values assigned to internal
275 variables, put into the value history or exposed to Python are
276 taken off this list. */
279 /* Register number if the value is from a register. */
282 /* If zero, contents of this value are in the contents field. If
283 nonzero, contents are in inferior. If the lval field is lval_memory,
284 the contents are in inferior memory at location.address plus offset.
285 The lval field may also be lval_register.
287 WARNING: This field is used by the code which handles watchpoints
288 (see breakpoint.c) to decide whether a particular value can be
289 watched by hardware watchpoints. If the lazy flag is set for
290 some member of a value chain, it is assumed that this member of
291 the chain doesn't need to be watched as part of watching the
292 value itself. This is how GDB avoids watching the entire struct
293 or array when the user wants to watch a single struct member or
294 array element. If you ever change the way lazy flag is set and
295 reset, be sure to consider this use as well! */
298 /* If nonzero, this is the value of a variable which does not
299 actually exist in the program. */
302 /* If value is a variable, is it initialized or not. */
305 /* If value is from the stack. If this is set, read_stack will be
306 used instead of read_memory to enable extra caching. */
309 /* Actual contents of the value. Target byte-order. NULL or not
310 valid if lazy is nonzero. */
313 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
314 rather than available, since the common and default case is for a
315 value to be available. This is filled in at value read time. */
316 VEC(range_s
) *unavailable
;
318 /* The number of references to this value. When a value is created,
319 the value chain holds a reference, so REFERENCE_COUNT is 1. If
320 release_value is called, this value is removed from the chain but
321 the caller of release_value now has a reference to this value.
322 The caller must arrange for a call to value_free later. */
327 value_bytes_available (const struct value
*value
, int offset
, int length
)
329 gdb_assert (!value
->lazy
);
331 return !ranges_contain (value
->unavailable
, offset
, length
);
335 value_entirely_available (struct value
*value
)
337 /* We can only tell whether the whole value is available when we try
340 value_fetch_lazy (value
);
342 if (VEC_empty (range_s
, value
->unavailable
))
348 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
353 /* Insert the range sorted. If there's overlap or the new range
354 would be contiguous with an existing range, merge. */
356 newr
.offset
= offset
;
357 newr
.length
= length
;
359 /* Do a binary search for the position the given range would be
360 inserted if we only considered the starting OFFSET of ranges.
361 Call that position I. Since we also have LENGTH to care for
362 (this is a range afterall), we need to check if the _previous_
363 range overlaps the I range. E.g., calling R the new range:
365 #1 - overlaps with previous
369 |---| |---| |------| ... |--|
374 In the case #1 above, the binary search would return `I=1',
375 meaning, this OFFSET should be inserted at position 1, and the
376 current position 1 should be pushed further (and become 2). But,
377 note that `0' overlaps with R, so we want to merge them.
379 A similar consideration needs to be taken if the new range would
380 be contiguous with the previous range:
382 #2 - contiguous with previous
386 |--| |---| |------| ... |--|
391 If there's no overlap with the previous range, as in:
393 #3 - not overlapping and not contiguous
397 |--| |---| |------| ... |--|
404 #4 - R is the range with lowest offset
408 |--| |---| |------| ... |--|
413 ... we just push the new range to I.
415 All the 4 cases above need to consider that the new range may
416 also overlap several of the ranges that follow, or that R may be
417 contiguous with the following range, and merge. E.g.,
419 #5 - overlapping following ranges
422 |------------------------|
423 |--| |---| |------| ... |--|
432 |--| |---| |------| ... |--|
439 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
442 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
444 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
447 ULONGEST l
= min (bef
->offset
, offset
);
448 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
454 else if (offset
== bef
->offset
+ bef
->length
)
457 bef
->length
+= length
;
463 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
469 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
472 /* Check whether the ranges following the one we've just added or
473 touched can be folded in (#5 above). */
474 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
481 /* Get the range we just touched. */
482 t
= VEC_index (range_s
, value
->unavailable
, i
);
486 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
487 if (r
->offset
<= t
->offset
+ t
->length
)
491 l
= min (t
->offset
, r
->offset
);
492 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
501 /* If we couldn't merge this one, we won't be able to
502 merge following ones either, since the ranges are
503 always sorted by OFFSET. */
508 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
512 /* Find the first range in RANGES that overlaps the range defined by
513 OFFSET and LENGTH, starting at element POS in the RANGES vector,
514 Returns the index into RANGES where such overlapping range was
515 found, or -1 if none was found. */
518 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
519 int offset
, int length
)
524 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
525 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
532 value_available_contents_eq (const struct value
*val1
, int offset1
,
533 const struct value
*val2
, int offset2
,
536 int idx1
= 0, idx2
= 0;
538 /* This routine is used by printing routines, where we should
539 already have read the value. Note that we only know whether a
540 value chunk is available if we've tried to read it. */
541 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
549 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
551 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
554 /* The usual case is for both values to be completely available. */
555 if (idx1
== -1 && idx2
== -1)
556 return (memcmp (val1
->contents
+ offset1
,
557 val2
->contents
+ offset2
,
559 /* The contents only match equal if the available set matches as
561 else if (idx1
== -1 || idx2
== -1)
564 gdb_assert (idx1
!= -1 && idx2
!= -1);
566 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
567 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
569 /* Get the unavailable windows intersected by the incoming
570 ranges. The first and last ranges that overlap the argument
571 range may be wider than said incoming arguments ranges. */
572 l1
= max (offset1
, r1
->offset
);
573 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
575 l2
= max (offset2
, r2
->offset
);
576 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
578 /* Make them relative to the respective start offsets, so we can
579 compare them for equality. */
586 /* Different availability, no match. */
587 if (l1
!= l2
|| h1
!= h2
)
590 /* Compare the _available_ contents. */
591 if (memcmp (val1
->contents
+ offset1
,
592 val2
->contents
+ offset2
,
604 /* Prototypes for local functions. */
606 static void show_values (char *, int);
608 static void show_convenience (char *, int);
611 /* The value-history records all the values printed
612 by print commands during this session. Each chunk
613 records 60 consecutive values. The first chunk on
614 the chain records the most recent values.
615 The total number of values is in value_history_count. */
617 #define VALUE_HISTORY_CHUNK 60
619 struct value_history_chunk
621 struct value_history_chunk
*next
;
622 struct value
*values
[VALUE_HISTORY_CHUNK
];
625 /* Chain of chunks now in use. */
627 static struct value_history_chunk
*value_history_chain
;
629 static int value_history_count
; /* Abs number of last entry stored. */
632 /* List of all value objects currently allocated
633 (except for those released by calls to release_value)
634 This is so they can be freed after each command. */
636 static struct value
*all_values
;
638 /* Allocate a lazy value for type TYPE. Its actual content is
639 "lazily" allocated too: the content field of the return value is
640 NULL; it will be allocated when it is fetched from the target. */
643 allocate_value_lazy (struct type
*type
)
647 /* Call check_typedef on our type to make sure that, if TYPE
648 is a TYPE_CODE_TYPEDEF, its length is set to the length
649 of the target type instead of zero. However, we do not
650 replace the typedef type by the target type, because we want
651 to keep the typedef in order to be able to set the VAL's type
652 description correctly. */
653 check_typedef (type
);
655 val
= (struct value
*) xzalloc (sizeof (struct value
));
656 val
->contents
= NULL
;
657 val
->next
= all_values
;
660 val
->enclosing_type
= type
;
661 VALUE_LVAL (val
) = not_lval
;
662 val
->location
.address
= 0;
663 VALUE_FRAME_ID (val
) = null_frame_id
;
667 VALUE_REGNUM (val
) = -1;
669 val
->optimized_out
= 0;
670 val
->embedded_offset
= 0;
671 val
->pointed_to_offset
= 0;
673 val
->initialized
= 1; /* Default to initialized. */
675 /* Values start out on the all_values chain. */
676 val
->reference_count
= 1;
681 /* Allocate the contents of VAL if it has not been allocated yet. */
684 allocate_value_contents (struct value
*val
)
687 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
690 /* Allocate a value and its contents for type TYPE. */
693 allocate_value (struct type
*type
)
695 struct value
*val
= allocate_value_lazy (type
);
697 allocate_value_contents (val
);
702 /* Allocate a value that has the correct length
703 for COUNT repetitions of type TYPE. */
706 allocate_repeat_value (struct type
*type
, int count
)
708 int low_bound
= current_language
->string_lower_bound
; /* ??? */
709 /* FIXME-type-allocation: need a way to free this type when we are
711 struct type
*array_type
712 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
714 return allocate_value (array_type
);
718 allocate_computed_value (struct type
*type
,
719 struct lval_funcs
*funcs
,
722 struct value
*v
= allocate_value_lazy (type
);
724 VALUE_LVAL (v
) = lval_computed
;
725 v
->location
.computed
.funcs
= funcs
;
726 v
->location
.computed
.closure
= closure
;
731 /* Accessor methods. */
734 value_next (struct value
*value
)
740 value_type (const struct value
*value
)
745 deprecated_set_value_type (struct value
*value
, struct type
*type
)
751 value_offset (const struct value
*value
)
753 return value
->offset
;
756 set_value_offset (struct value
*value
, int offset
)
758 value
->offset
= offset
;
762 value_bitpos (const struct value
*value
)
764 return value
->bitpos
;
767 set_value_bitpos (struct value
*value
, int bit
)
773 value_bitsize (const struct value
*value
)
775 return value
->bitsize
;
778 set_value_bitsize (struct value
*value
, int bit
)
780 value
->bitsize
= bit
;
784 value_parent (struct value
*value
)
786 return value
->parent
;
790 value_contents_raw (struct value
*value
)
792 allocate_value_contents (value
);
793 return value
->contents
+ value
->embedded_offset
;
797 value_contents_all_raw (struct value
*value
)
799 allocate_value_contents (value
);
800 return value
->contents
;
804 value_enclosing_type (struct value
*value
)
806 return value
->enclosing_type
;
810 require_not_optimized_out (const struct value
*value
)
812 if (value
->optimized_out
)
813 error (_("value has been optimized out"));
817 require_available (const struct value
*value
)
819 if (!VEC_empty (range_s
, value
->unavailable
))
820 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
824 value_contents_for_printing (struct value
*value
)
827 value_fetch_lazy (value
);
828 return value
->contents
;
832 value_contents_for_printing_const (const struct value
*value
)
834 gdb_assert (!value
->lazy
);
835 return value
->contents
;
839 value_contents_all (struct value
*value
)
841 const gdb_byte
*result
= value_contents_for_printing (value
);
842 require_not_optimized_out (value
);
843 require_available (value
);
847 /* Copy LENGTH bytes of SRC value's (all) contents
848 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
849 contents, starting at DST_OFFSET. If unavailable contents are
850 being copied from SRC, the corresponding DST contents are marked
851 unavailable accordingly. Neither DST nor SRC may be lazy
854 It is assumed the contents of DST in the [DST_OFFSET,
855 DST_OFFSET+LENGTH) range are wholly available. */
858 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
859 struct value
*src
, int src_offset
, int length
)
864 /* A lazy DST would make that this copy operation useless, since as
865 soon as DST's contents were un-lazied (by a later value_contents
866 call, say), the contents would be overwritten. A lazy SRC would
867 mean we'd be copying garbage. */
868 gdb_assert (!dst
->lazy
&& !src
->lazy
);
870 /* The overwritten DST range gets unavailability ORed in, not
871 replaced. Make sure to remember to implement replacing if it
872 turns out actually necessary. */
873 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
876 memcpy (value_contents_all_raw (dst
) + dst_offset
,
877 value_contents_all_raw (src
) + src_offset
,
880 /* Copy the meta-data, adjusted. */
881 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
885 l
= max (r
->offset
, src_offset
);
886 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
889 mark_value_bytes_unavailable (dst
,
890 dst_offset
+ (l
- src_offset
),
895 /* Copy LENGTH bytes of SRC value's (all) contents
896 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
897 (all) contents, starting at DST_OFFSET. If unavailable contents
898 are being copied from SRC, the corresponding DST contents are
899 marked unavailable accordingly. DST must not be lazy. If SRC is
900 lazy, it will be fetched now. If SRC is not valid (is optimized
901 out), an error is thrown.
903 It is assumed the contents of DST in the [DST_OFFSET,
904 DST_OFFSET+LENGTH) range are wholly available. */
907 value_contents_copy (struct value
*dst
, int dst_offset
,
908 struct value
*src
, int src_offset
, int length
)
910 require_not_optimized_out (src
);
913 value_fetch_lazy (src
);
915 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
919 value_lazy (struct value
*value
)
925 set_value_lazy (struct value
*value
, int val
)
931 value_stack (struct value
*value
)
937 set_value_stack (struct value
*value
, int val
)
943 value_contents (struct value
*value
)
945 const gdb_byte
*result
= value_contents_writeable (value
);
946 require_not_optimized_out (value
);
947 require_available (value
);
952 value_contents_writeable (struct value
*value
)
955 value_fetch_lazy (value
);
956 return value_contents_raw (value
);
959 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
960 this function is different from value_equal; in C the operator ==
961 can return 0 even if the two values being compared are equal. */
964 value_contents_equal (struct value
*val1
, struct value
*val2
)
970 type1
= check_typedef (value_type (val1
));
971 type2
= check_typedef (value_type (val2
));
972 len
= TYPE_LENGTH (type1
);
973 if (len
!= TYPE_LENGTH (type2
))
976 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
980 value_optimized_out (struct value
*value
)
982 return value
->optimized_out
;
986 set_value_optimized_out (struct value
*value
, int val
)
988 value
->optimized_out
= val
;
992 value_entirely_optimized_out (const struct value
*value
)
994 if (!value
->optimized_out
)
996 if (value
->lval
!= lval_computed
997 || !value
->location
.computed
.funcs
->check_any_valid
)
999 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1003 value_bits_valid (const struct value
*value
, int offset
, int length
)
1005 if (!value
->optimized_out
)
1007 if (value
->lval
!= lval_computed
1008 || !value
->location
.computed
.funcs
->check_validity
)
1010 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1015 value_bits_synthetic_pointer (const struct value
*value
,
1016 int offset
, int length
)
1018 if (value
->lval
!= lval_computed
1019 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1021 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1027 value_embedded_offset (struct value
*value
)
1029 return value
->embedded_offset
;
1033 set_value_embedded_offset (struct value
*value
, int val
)
1035 value
->embedded_offset
= val
;
1039 value_pointed_to_offset (struct value
*value
)
1041 return value
->pointed_to_offset
;
1045 set_value_pointed_to_offset (struct value
*value
, int val
)
1047 value
->pointed_to_offset
= val
;
1051 value_computed_funcs (struct value
*v
)
1053 gdb_assert (VALUE_LVAL (v
) == lval_computed
);
1055 return v
->location
.computed
.funcs
;
1059 value_computed_closure (const struct value
*v
)
1061 gdb_assert (v
->lval
== lval_computed
);
1063 return v
->location
.computed
.closure
;
1067 deprecated_value_lval_hack (struct value
*value
)
1069 return &value
->lval
;
1073 value_address (const struct value
*value
)
1075 if (value
->lval
== lval_internalvar
1076 || value
->lval
== lval_internalvar_component
)
1078 return value
->location
.address
+ value
->offset
;
1082 value_raw_address (struct value
*value
)
1084 if (value
->lval
== lval_internalvar
1085 || value
->lval
== lval_internalvar_component
)
1087 return value
->location
.address
;
1091 set_value_address (struct value
*value
, CORE_ADDR addr
)
1093 gdb_assert (value
->lval
!= lval_internalvar
1094 && value
->lval
!= lval_internalvar_component
);
1095 value
->location
.address
= addr
;
1098 struct internalvar
**
1099 deprecated_value_internalvar_hack (struct value
*value
)
1101 return &value
->location
.internalvar
;
1105 deprecated_value_frame_id_hack (struct value
*value
)
1107 return &value
->frame_id
;
1111 deprecated_value_regnum_hack (struct value
*value
)
1113 return &value
->regnum
;
1117 deprecated_value_modifiable (struct value
*value
)
1119 return value
->modifiable
;
1122 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1124 value
->modifiable
= modifiable
;
1127 /* Return a mark in the value chain. All values allocated after the
1128 mark is obtained (except for those released) are subject to being freed
1129 if a subsequent value_free_to_mark is passed the mark. */
1136 /* Take a reference to VAL. VAL will not be deallocated until all
1137 references are released. */
1140 value_incref (struct value
*val
)
1142 val
->reference_count
++;
1145 /* Release a reference to VAL, which was acquired with value_incref.
1146 This function is also called to deallocate values from the value
1150 value_free (struct value
*val
)
1154 gdb_assert (val
->reference_count
> 0);
1155 val
->reference_count
--;
1156 if (val
->reference_count
> 0)
1159 /* If there's an associated parent value, drop our reference to
1161 if (val
->parent
!= NULL
)
1162 value_free (val
->parent
);
1164 if (VALUE_LVAL (val
) == lval_computed
)
1166 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1168 if (funcs
->free_closure
)
1169 funcs
->free_closure (val
);
1172 xfree (val
->contents
);
1173 VEC_free (range_s
, val
->unavailable
);
1178 /* Free all values allocated since MARK was obtained by value_mark
1179 (except for those released). */
1181 value_free_to_mark (struct value
*mark
)
1186 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1194 /* Free all the values that have been allocated (except for those released).
1195 Call after each command, successful or not.
1196 In practice this is called before each command, which is sufficient. */
1199 free_all_values (void)
1204 for (val
= all_values
; val
; val
= next
)
1213 /* Frees all the elements in a chain of values. */
1216 free_value_chain (struct value
*v
)
1222 next
= value_next (v
);
1227 /* Remove VAL from the chain all_values
1228 so it will not be freed automatically. */
1231 release_value (struct value
*val
)
1235 if (all_values
== val
)
1237 all_values
= val
->next
;
1242 for (v
= all_values
; v
; v
= v
->next
)
1246 v
->next
= val
->next
;
1253 /* Release all values up to mark */
1255 value_release_to_mark (struct value
*mark
)
1260 for (val
= next
= all_values
; next
; next
= next
->next
)
1261 if (next
->next
== mark
)
1263 all_values
= next
->next
;
1271 /* Return a copy of the value ARG.
1272 It contains the same contents, for same memory address,
1273 but it's a different block of storage. */
1276 value_copy (struct value
*arg
)
1278 struct type
*encl_type
= value_enclosing_type (arg
);
1281 if (value_lazy (arg
))
1282 val
= allocate_value_lazy (encl_type
);
1284 val
= allocate_value (encl_type
);
1285 val
->type
= arg
->type
;
1286 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1287 val
->location
= arg
->location
;
1288 val
->offset
= arg
->offset
;
1289 val
->bitpos
= arg
->bitpos
;
1290 val
->bitsize
= arg
->bitsize
;
1291 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1292 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1293 val
->lazy
= arg
->lazy
;
1294 val
->optimized_out
= arg
->optimized_out
;
1295 val
->embedded_offset
= value_embedded_offset (arg
);
1296 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1297 val
->modifiable
= arg
->modifiable
;
1298 if (!value_lazy (val
))
1300 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1301 TYPE_LENGTH (value_enclosing_type (arg
)));
1304 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1305 val
->parent
= arg
->parent
;
1307 value_incref (val
->parent
);
1308 if (VALUE_LVAL (val
) == lval_computed
)
1310 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1312 if (funcs
->copy_closure
)
1313 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1318 /* Return a version of ARG that is non-lvalue. */
1321 value_non_lval (struct value
*arg
)
1323 if (VALUE_LVAL (arg
) != not_lval
)
1325 struct type
*enc_type
= value_enclosing_type (arg
);
1326 struct value
*val
= allocate_value (enc_type
);
1328 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1329 TYPE_LENGTH (enc_type
));
1330 val
->type
= arg
->type
;
1331 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1332 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1339 set_value_component_location (struct value
*component
,
1340 const struct value
*whole
)
1342 if (whole
->lval
== lval_internalvar
)
1343 VALUE_LVAL (component
) = lval_internalvar_component
;
1345 VALUE_LVAL (component
) = whole
->lval
;
1347 component
->location
= whole
->location
;
1348 if (whole
->lval
== lval_computed
)
1350 struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1352 if (funcs
->copy_closure
)
1353 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1358 /* Access to the value history. */
1360 /* Record a new value in the value history.
1361 Returns the absolute history index of the entry.
1362 Result of -1 indicates the value was not saved; otherwise it is the
1363 value history index of this new item. */
1366 record_latest_value (struct value
*val
)
1370 /* We don't want this value to have anything to do with the inferior anymore.
1371 In particular, "set $1 = 50" should not affect the variable from which
1372 the value was taken, and fast watchpoints should be able to assume that
1373 a value on the value history never changes. */
1374 if (value_lazy (val
))
1375 value_fetch_lazy (val
);
1376 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1377 from. This is a bit dubious, because then *&$1 does not just return $1
1378 but the current contents of that location. c'est la vie... */
1379 val
->modifiable
= 0;
1380 release_value (val
);
1382 /* Here we treat value_history_count as origin-zero
1383 and applying to the value being stored now. */
1385 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1388 struct value_history_chunk
*new
1389 = (struct value_history_chunk
*)
1391 xmalloc (sizeof (struct value_history_chunk
));
1392 memset (new->values
, 0, sizeof new->values
);
1393 new->next
= value_history_chain
;
1394 value_history_chain
= new;
1397 value_history_chain
->values
[i
] = val
;
1399 /* Now we regard value_history_count as origin-one
1400 and applying to the value just stored. */
1402 return ++value_history_count
;
1405 /* Return a copy of the value in the history with sequence number NUM. */
1408 access_value_history (int num
)
1410 struct value_history_chunk
*chunk
;
1415 absnum
+= value_history_count
;
1420 error (_("The history is empty."));
1422 error (_("There is only one value in the history."));
1424 error (_("History does not go back to $$%d."), -num
);
1426 if (absnum
> value_history_count
)
1427 error (_("History has not yet reached $%d."), absnum
);
1431 /* Now absnum is always absolute and origin zero. */
1433 chunk
= value_history_chain
;
1434 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1435 - absnum
/ VALUE_HISTORY_CHUNK
;
1437 chunk
= chunk
->next
;
1439 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1443 show_values (char *num_exp
, int from_tty
)
1451 /* "show values +" should print from the stored position.
1452 "show values <exp>" should print around value number <exp>. */
1453 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1454 num
= parse_and_eval_long (num_exp
) - 5;
1458 /* "show values" means print the last 10 values. */
1459 num
= value_history_count
- 9;
1465 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1467 struct value_print_options opts
;
1469 val
= access_value_history (i
);
1470 printf_filtered (("$%d = "), i
);
1471 get_user_print_options (&opts
);
1472 value_print (val
, gdb_stdout
, &opts
);
1473 printf_filtered (("\n"));
1476 /* The next "show values +" should start after what we just printed. */
1479 /* Hitting just return after this command should do the same thing as
1480 "show values +". If num_exp is null, this is unnecessary, since
1481 "show values +" is not useful after "show values". */
1482 if (from_tty
&& num_exp
)
1489 /* Internal variables. These are variables within the debugger
1490 that hold values assigned by debugger commands.
1491 The user refers to them with a '$' prefix
1492 that does not appear in the variable names stored internally. */
1496 struct internalvar
*next
;
1499 /* We support various different kinds of content of an internal variable.
1500 enum internalvar_kind specifies the kind, and union internalvar_data
1501 provides the data associated with this particular kind. */
1503 enum internalvar_kind
1505 /* The internal variable is empty. */
1508 /* The value of the internal variable is provided directly as
1509 a GDB value object. */
1512 /* A fresh value is computed via a call-back routine on every
1513 access to the internal variable. */
1514 INTERNALVAR_MAKE_VALUE
,
1516 /* The internal variable holds a GDB internal convenience function. */
1517 INTERNALVAR_FUNCTION
,
1519 /* The variable holds an integer value. */
1520 INTERNALVAR_INTEGER
,
1522 /* The variable holds a GDB-provided string. */
1527 union internalvar_data
1529 /* A value object used with INTERNALVAR_VALUE. */
1530 struct value
*value
;
1532 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1533 internalvar_make_value make_value
;
1535 /* The internal function used with INTERNALVAR_FUNCTION. */
1538 struct internal_function
*function
;
1539 /* True if this is the canonical name for the function. */
1543 /* An integer value used with INTERNALVAR_INTEGER. */
1546 /* If type is non-NULL, it will be used as the type to generate
1547 a value for this internal variable. If type is NULL, a default
1548 integer type for the architecture is used. */
1553 /* A string value used with INTERNALVAR_STRING. */
1558 static struct internalvar
*internalvars
;
1560 /* If the variable does not already exist create it and give it the
1561 value given. If no value is given then the default is zero. */
1563 init_if_undefined_command (char* args
, int from_tty
)
1565 struct internalvar
* intvar
;
1567 /* Parse the expression - this is taken from set_command(). */
1568 struct expression
*expr
= parse_expression (args
);
1569 register struct cleanup
*old_chain
=
1570 make_cleanup (free_current_contents
, &expr
);
1572 /* Validate the expression.
1573 Was the expression an assignment?
1574 Or even an expression at all? */
1575 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1576 error (_("Init-if-undefined requires an assignment expression."));
1578 /* Extract the variable from the parsed expression.
1579 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1580 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1581 error (_("The first parameter to init-if-undefined "
1582 "should be a GDB variable."));
1583 intvar
= expr
->elts
[2].internalvar
;
1585 /* Only evaluate the expression if the lvalue is void.
1586 This may still fail if the expresssion is invalid. */
1587 if (intvar
->kind
== INTERNALVAR_VOID
)
1588 evaluate_expression (expr
);
1590 do_cleanups (old_chain
);
1594 /* Look up an internal variable with name NAME. NAME should not
1595 normally include a dollar sign.
1597 If the specified internal variable does not exist,
1598 the return value is NULL. */
1600 struct internalvar
*
1601 lookup_only_internalvar (const char *name
)
1603 struct internalvar
*var
;
1605 for (var
= internalvars
; var
; var
= var
->next
)
1606 if (strcmp (var
->name
, name
) == 0)
1613 /* Create an internal variable with name NAME and with a void value.
1614 NAME should not normally include a dollar sign. */
1616 struct internalvar
*
1617 create_internalvar (const char *name
)
1619 struct internalvar
*var
;
1621 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1622 var
->name
= concat (name
, (char *)NULL
);
1623 var
->kind
= INTERNALVAR_VOID
;
1624 var
->next
= internalvars
;
1629 /* Create an internal variable with name NAME and register FUN as the
1630 function that value_of_internalvar uses to create a value whenever
1631 this variable is referenced. NAME should not normally include a
1634 struct internalvar
*
1635 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1637 struct internalvar
*var
= create_internalvar (name
);
1639 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1640 var
->u
.make_value
= fun
;
1644 /* Look up an internal variable with name NAME. NAME should not
1645 normally include a dollar sign.
1647 If the specified internal variable does not exist,
1648 one is created, with a void value. */
1650 struct internalvar
*
1651 lookup_internalvar (const char *name
)
1653 struct internalvar
*var
;
1655 var
= lookup_only_internalvar (name
);
1659 return create_internalvar (name
);
1662 /* Return current value of internal variable VAR. For variables that
1663 are not inherently typed, use a value type appropriate for GDBARCH. */
1666 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1669 struct trace_state_variable
*tsv
;
1671 /* If there is a trace state variable of the same name, assume that
1672 is what we really want to see. */
1673 tsv
= find_trace_state_variable (var
->name
);
1676 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1678 if (tsv
->value_known
)
1679 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1682 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1688 case INTERNALVAR_VOID
:
1689 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1692 case INTERNALVAR_FUNCTION
:
1693 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1696 case INTERNALVAR_INTEGER
:
1697 if (!var
->u
.integer
.type
)
1698 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1699 var
->u
.integer
.val
);
1701 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1704 case INTERNALVAR_STRING
:
1705 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1706 builtin_type (gdbarch
)->builtin_char
);
1709 case INTERNALVAR_VALUE
:
1710 val
= value_copy (var
->u
.value
);
1711 if (value_lazy (val
))
1712 value_fetch_lazy (val
);
1715 case INTERNALVAR_MAKE_VALUE
:
1716 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1720 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1723 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1724 on this value go back to affect the original internal variable.
1726 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1727 no underlying modifyable state in the internal variable.
1729 Likewise, if the variable's value is a computed lvalue, we want
1730 references to it to produce another computed lvalue, where
1731 references and assignments actually operate through the
1732 computed value's functions.
1734 This means that internal variables with computed values
1735 behave a little differently from other internal variables:
1736 assignments to them don't just replace the previous value
1737 altogether. At the moment, this seems like the behavior we
1740 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1741 && val
->lval
!= lval_computed
)
1743 VALUE_LVAL (val
) = lval_internalvar
;
1744 VALUE_INTERNALVAR (val
) = var
;
1751 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1753 if (var
->kind
== INTERNALVAR_INTEGER
)
1755 *result
= var
->u
.integer
.val
;
1759 if (var
->kind
== INTERNALVAR_VALUE
)
1761 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1763 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1765 *result
= value_as_long (var
->u
.value
);
1774 get_internalvar_function (struct internalvar
*var
,
1775 struct internal_function
**result
)
1779 case INTERNALVAR_FUNCTION
:
1780 *result
= var
->u
.fn
.function
;
1789 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1790 int bitsize
, struct value
*newval
)
1796 case INTERNALVAR_VALUE
:
1797 addr
= value_contents_writeable (var
->u
.value
);
1800 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1801 value_as_long (newval
), bitpos
, bitsize
);
1803 memcpy (addr
+ offset
, value_contents (newval
),
1804 TYPE_LENGTH (value_type (newval
)));
1808 /* We can never get a component of any other kind. */
1809 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1814 set_internalvar (struct internalvar
*var
, struct value
*val
)
1816 enum internalvar_kind new_kind
;
1817 union internalvar_data new_data
= { 0 };
1819 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1820 error (_("Cannot overwrite convenience function %s"), var
->name
);
1822 /* Prepare new contents. */
1823 switch (TYPE_CODE (check_typedef (value_type (val
))))
1825 case TYPE_CODE_VOID
:
1826 new_kind
= INTERNALVAR_VOID
;
1829 case TYPE_CODE_INTERNAL_FUNCTION
:
1830 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1831 new_kind
= INTERNALVAR_FUNCTION
;
1832 get_internalvar_function (VALUE_INTERNALVAR (val
),
1833 &new_data
.fn
.function
);
1834 /* Copies created here are never canonical. */
1838 new_kind
= INTERNALVAR_VALUE
;
1839 new_data
.value
= value_copy (val
);
1840 new_data
.value
->modifiable
= 1;
1842 /* Force the value to be fetched from the target now, to avoid problems
1843 later when this internalvar is referenced and the target is gone or
1845 if (value_lazy (new_data
.value
))
1846 value_fetch_lazy (new_data
.value
);
1848 /* Release the value from the value chain to prevent it from being
1849 deleted by free_all_values. From here on this function should not
1850 call error () until new_data is installed into the var->u to avoid
1852 release_value (new_data
.value
);
1856 /* Clean up old contents. */
1857 clear_internalvar (var
);
1860 var
->kind
= new_kind
;
1862 /* End code which must not call error(). */
1866 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1868 /* Clean up old contents. */
1869 clear_internalvar (var
);
1871 var
->kind
= INTERNALVAR_INTEGER
;
1872 var
->u
.integer
.type
= NULL
;
1873 var
->u
.integer
.val
= l
;
1877 set_internalvar_string (struct internalvar
*var
, const char *string
)
1879 /* Clean up old contents. */
1880 clear_internalvar (var
);
1882 var
->kind
= INTERNALVAR_STRING
;
1883 var
->u
.string
= xstrdup (string
);
1887 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1889 /* Clean up old contents. */
1890 clear_internalvar (var
);
1892 var
->kind
= INTERNALVAR_FUNCTION
;
1893 var
->u
.fn
.function
= f
;
1894 var
->u
.fn
.canonical
= 1;
1895 /* Variables installed here are always the canonical version. */
1899 clear_internalvar (struct internalvar
*var
)
1901 /* Clean up old contents. */
1904 case INTERNALVAR_VALUE
:
1905 value_free (var
->u
.value
);
1908 case INTERNALVAR_STRING
:
1909 xfree (var
->u
.string
);
1916 /* Reset to void kind. */
1917 var
->kind
= INTERNALVAR_VOID
;
1921 internalvar_name (struct internalvar
*var
)
1926 static struct internal_function
*
1927 create_internal_function (const char *name
,
1928 internal_function_fn handler
, void *cookie
)
1930 struct internal_function
*ifn
= XNEW (struct internal_function
);
1932 ifn
->name
= xstrdup (name
);
1933 ifn
->handler
= handler
;
1934 ifn
->cookie
= cookie
;
1939 value_internal_function_name (struct value
*val
)
1941 struct internal_function
*ifn
;
1944 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1945 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
1946 gdb_assert (result
);
1952 call_internal_function (struct gdbarch
*gdbarch
,
1953 const struct language_defn
*language
,
1954 struct value
*func
, int argc
, struct value
**argv
)
1956 struct internal_function
*ifn
;
1959 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
1960 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
1961 gdb_assert (result
);
1963 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
1966 /* The 'function' command. This does nothing -- it is just a
1967 placeholder to let "help function NAME" work. This is also used as
1968 the implementation of the sub-command that is created when
1969 registering an internal function. */
1971 function_command (char *command
, int from_tty
)
1976 /* Clean up if an internal function's command is destroyed. */
1978 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
1984 /* Add a new internal function. NAME is the name of the function; DOC
1985 is a documentation string describing the function. HANDLER is
1986 called when the function is invoked. COOKIE is an arbitrary
1987 pointer which is passed to HANDLER and is intended for "user
1990 add_internal_function (const char *name
, const char *doc
,
1991 internal_function_fn handler
, void *cookie
)
1993 struct cmd_list_element
*cmd
;
1994 struct internal_function
*ifn
;
1995 struct internalvar
*var
= lookup_internalvar (name
);
1997 ifn
= create_internal_function (name
, handler
, cookie
);
1998 set_internalvar_function (var
, ifn
);
2000 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2002 cmd
->destroyer
= function_destroyer
;
2005 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2006 prevent cycles / duplicates. */
2009 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2010 htab_t copied_types
)
2012 if (TYPE_OBJFILE (value
->type
) == objfile
)
2013 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2015 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2016 value
->enclosing_type
= copy_type_recursive (objfile
,
2017 value
->enclosing_type
,
2021 /* Likewise for internal variable VAR. */
2024 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2025 htab_t copied_types
)
2029 case INTERNALVAR_INTEGER
:
2030 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2032 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2035 case INTERNALVAR_VALUE
:
2036 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2041 /* Update the internal variables and value history when OBJFILE is
2042 discarded; we must copy the types out of the objfile. New global types
2043 will be created for every convenience variable which currently points to
2044 this objfile's types, and the convenience variables will be adjusted to
2045 use the new global types. */
2048 preserve_values (struct objfile
*objfile
)
2050 htab_t copied_types
;
2051 struct value_history_chunk
*cur
;
2052 struct internalvar
*var
;
2055 /* Create the hash table. We allocate on the objfile's obstack, since
2056 it is soon to be deleted. */
2057 copied_types
= create_copied_types_hash (objfile
);
2059 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2060 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2062 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2064 for (var
= internalvars
; var
; var
= var
->next
)
2065 preserve_one_internalvar (var
, objfile
, copied_types
);
2067 preserve_python_values (objfile
, copied_types
);
2069 htab_delete (copied_types
);
2073 show_convenience (char *ignore
, int from_tty
)
2075 struct gdbarch
*gdbarch
= get_current_arch ();
2076 struct internalvar
*var
;
2078 struct value_print_options opts
;
2080 get_user_print_options (&opts
);
2081 for (var
= internalvars
; var
; var
= var
->next
)
2087 printf_filtered (("$%s = "), var
->name
);
2088 value_print (value_of_internalvar (gdbarch
, var
), gdb_stdout
,
2090 printf_filtered (("\n"));
2093 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2094 "Convenience variables have "
2095 "names starting with \"$\";\n"
2096 "use \"set\" as in \"set "
2097 "$foo = 5\" to define them.\n"));
2100 /* Extract a value as a C number (either long or double).
2101 Knows how to convert fixed values to double, or
2102 floating values to long.
2103 Does not deallocate the value. */
2106 value_as_long (struct value
*val
)
2108 /* This coerces arrays and functions, which is necessary (e.g.
2109 in disassemble_command). It also dereferences references, which
2110 I suspect is the most logical thing to do. */
2111 val
= coerce_array (val
);
2112 return unpack_long (value_type (val
), value_contents (val
));
2116 value_as_double (struct value
*val
)
2121 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2123 error (_("Invalid floating value found in program."));
2127 /* Extract a value as a C pointer. Does not deallocate the value.
2128 Note that val's type may not actually be a pointer; value_as_long
2129 handles all the cases. */
2131 value_as_address (struct value
*val
)
2133 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2135 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2136 whether we want this to be true eventually. */
2138 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2139 non-address (e.g. argument to "signal", "info break", etc.), or
2140 for pointers to char, in which the low bits *are* significant. */
2141 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2144 /* There are several targets (IA-64, PowerPC, and others) which
2145 don't represent pointers to functions as simply the address of
2146 the function's entry point. For example, on the IA-64, a
2147 function pointer points to a two-word descriptor, generated by
2148 the linker, which contains the function's entry point, and the
2149 value the IA-64 "global pointer" register should have --- to
2150 support position-independent code. The linker generates
2151 descriptors only for those functions whose addresses are taken.
2153 On such targets, it's difficult for GDB to convert an arbitrary
2154 function address into a function pointer; it has to either find
2155 an existing descriptor for that function, or call malloc and
2156 build its own. On some targets, it is impossible for GDB to
2157 build a descriptor at all: the descriptor must contain a jump
2158 instruction; data memory cannot be executed; and code memory
2161 Upon entry to this function, if VAL is a value of type `function'
2162 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2163 value_address (val) is the address of the function. This is what
2164 you'll get if you evaluate an expression like `main'. The call
2165 to COERCE_ARRAY below actually does all the usual unary
2166 conversions, which includes converting values of type `function'
2167 to `pointer to function'. This is the challenging conversion
2168 discussed above. Then, `unpack_long' will convert that pointer
2169 back into an address.
2171 So, suppose the user types `disassemble foo' on an architecture
2172 with a strange function pointer representation, on which GDB
2173 cannot build its own descriptors, and suppose further that `foo'
2174 has no linker-built descriptor. The address->pointer conversion
2175 will signal an error and prevent the command from running, even
2176 though the next step would have been to convert the pointer
2177 directly back into the same address.
2179 The following shortcut avoids this whole mess. If VAL is a
2180 function, just return its address directly. */
2181 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2182 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2183 return value_address (val
);
2185 val
= coerce_array (val
);
2187 /* Some architectures (e.g. Harvard), map instruction and data
2188 addresses onto a single large unified address space. For
2189 instance: An architecture may consider a large integer in the
2190 range 0x10000000 .. 0x1000ffff to already represent a data
2191 addresses (hence not need a pointer to address conversion) while
2192 a small integer would still need to be converted integer to
2193 pointer to address. Just assume such architectures handle all
2194 integer conversions in a single function. */
2198 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2199 must admonish GDB hackers to make sure its behavior matches the
2200 compiler's, whenever possible.
2202 In general, I think GDB should evaluate expressions the same way
2203 the compiler does. When the user copies an expression out of
2204 their source code and hands it to a `print' command, they should
2205 get the same value the compiler would have computed. Any
2206 deviation from this rule can cause major confusion and annoyance,
2207 and needs to be justified carefully. In other words, GDB doesn't
2208 really have the freedom to do these conversions in clever and
2211 AndrewC pointed out that users aren't complaining about how GDB
2212 casts integers to pointers; they are complaining that they can't
2213 take an address from a disassembly listing and give it to `x/i'.
2214 This is certainly important.
2216 Adding an architecture method like integer_to_address() certainly
2217 makes it possible for GDB to "get it right" in all circumstances
2218 --- the target has complete control over how things get done, so
2219 people can Do The Right Thing for their target without breaking
2220 anyone else. The standard doesn't specify how integers get
2221 converted to pointers; usually, the ABI doesn't either, but
2222 ABI-specific code is a more reasonable place to handle it. */
2224 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2225 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2226 && gdbarch_integer_to_address_p (gdbarch
))
2227 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2228 value_contents (val
));
2230 return unpack_long (value_type (val
), value_contents (val
));
2234 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2235 as a long, or as a double, assuming the raw data is described
2236 by type TYPE. Knows how to convert different sizes of values
2237 and can convert between fixed and floating point. We don't assume
2238 any alignment for the raw data. Return value is in host byte order.
2240 If you want functions and arrays to be coerced to pointers, and
2241 references to be dereferenced, call value_as_long() instead.
2243 C++: It is assumed that the front-end has taken care of
2244 all matters concerning pointers to members. A pointer
2245 to member which reaches here is considered to be equivalent
2246 to an INT (or some size). After all, it is only an offset. */
2249 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2251 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2252 enum type_code code
= TYPE_CODE (type
);
2253 int len
= TYPE_LENGTH (type
);
2254 int nosign
= TYPE_UNSIGNED (type
);
2258 case TYPE_CODE_TYPEDEF
:
2259 return unpack_long (check_typedef (type
), valaddr
);
2260 case TYPE_CODE_ENUM
:
2261 case TYPE_CODE_FLAGS
:
2262 case TYPE_CODE_BOOL
:
2264 case TYPE_CODE_CHAR
:
2265 case TYPE_CODE_RANGE
:
2266 case TYPE_CODE_MEMBERPTR
:
2268 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2270 return extract_signed_integer (valaddr
, len
, byte_order
);
2273 return extract_typed_floating (valaddr
, type
);
2275 case TYPE_CODE_DECFLOAT
:
2276 /* libdecnumber has a function to convert from decimal to integer, but
2277 it doesn't work when the decimal number has a fractional part. */
2278 return decimal_to_doublest (valaddr
, len
, byte_order
);
2282 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2283 whether we want this to be true eventually. */
2284 return extract_typed_address (valaddr
, type
);
2287 error (_("Value can't be converted to integer."));
2289 return 0; /* Placate lint. */
2292 /* Return a double value from the specified type and address.
2293 INVP points to an int which is set to 0 for valid value,
2294 1 for invalid value (bad float format). In either case,
2295 the returned double is OK to use. Argument is in target
2296 format, result is in host format. */
2299 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2301 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2302 enum type_code code
;
2306 *invp
= 0; /* Assume valid. */
2307 CHECK_TYPEDEF (type
);
2308 code
= TYPE_CODE (type
);
2309 len
= TYPE_LENGTH (type
);
2310 nosign
= TYPE_UNSIGNED (type
);
2311 if (code
== TYPE_CODE_FLT
)
2313 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2314 floating-point value was valid (using the macro
2315 INVALID_FLOAT). That test/macro have been removed.
2317 It turns out that only the VAX defined this macro and then
2318 only in a non-portable way. Fixing the portability problem
2319 wouldn't help since the VAX floating-point code is also badly
2320 bit-rotten. The target needs to add definitions for the
2321 methods gdbarch_float_format and gdbarch_double_format - these
2322 exactly describe the target floating-point format. The
2323 problem here is that the corresponding floatformat_vax_f and
2324 floatformat_vax_d values these methods should be set to are
2325 also not defined either. Oops!
2327 Hopefully someone will add both the missing floatformat
2328 definitions and the new cases for floatformat_is_valid (). */
2330 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2336 return extract_typed_floating (valaddr
, type
);
2338 else if (code
== TYPE_CODE_DECFLOAT
)
2339 return decimal_to_doublest (valaddr
, len
, byte_order
);
2342 /* Unsigned -- be sure we compensate for signed LONGEST. */
2343 return (ULONGEST
) unpack_long (type
, valaddr
);
2347 /* Signed -- we are OK with unpack_long. */
2348 return unpack_long (type
, valaddr
);
2352 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2353 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2354 We don't assume any alignment for the raw data. Return value is in
2357 If you want functions and arrays to be coerced to pointers, and
2358 references to be dereferenced, call value_as_address() instead.
2360 C++: It is assumed that the front-end has taken care of
2361 all matters concerning pointers to members. A pointer
2362 to member which reaches here is considered to be equivalent
2363 to an INT (or some size). After all, it is only an offset. */
2366 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2368 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2369 whether we want this to be true eventually. */
2370 return unpack_long (type
, valaddr
);
2374 /* Get the value of the FIELDNO'th field (which must be static) of
2375 TYPE. Return NULL if the field doesn't exist or has been
2379 value_static_field (struct type
*type
, int fieldno
)
2381 struct value
*retval
;
2383 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2385 case FIELD_LOC_KIND_PHYSADDR
:
2386 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2387 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2389 case FIELD_LOC_KIND_PHYSNAME
:
2391 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2392 /* TYPE_FIELD_NAME (type, fieldno); */
2393 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2397 /* With some compilers, e.g. HP aCC, static data members are
2398 reported as non-debuggable symbols. */
2399 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2406 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2407 SYMBOL_VALUE_ADDRESS (msym
));
2411 retval
= value_of_variable (sym
, NULL
);
2415 gdb_assert_not_reached ("unexpected field location kind");
2421 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2422 You have to be careful here, since the size of the data area for the value
2423 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2424 than the old enclosing type, you have to allocate more space for the
2428 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2430 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2432 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2434 val
->enclosing_type
= new_encl_type
;
2437 /* Given a value ARG1 (offset by OFFSET bytes)
2438 of a struct or union type ARG_TYPE,
2439 extract and return the value of one of its (non-static) fields.
2440 FIELDNO says which field. */
2443 value_primitive_field (struct value
*arg1
, int offset
,
2444 int fieldno
, struct type
*arg_type
)
2449 CHECK_TYPEDEF (arg_type
);
2450 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2452 /* Call check_typedef on our type to make sure that, if TYPE
2453 is a TYPE_CODE_TYPEDEF, its length is set to the length
2454 of the target type instead of zero. However, we do not
2455 replace the typedef type by the target type, because we want
2456 to keep the typedef in order to be able to print the type
2457 description correctly. */
2458 check_typedef (type
);
2460 /* Handle packed fields */
2462 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2464 /* Create a new value for the bitfield, with bitpos and bitsize
2465 set. If possible, arrange offset and bitpos so that we can
2466 do a single aligned read of the size of the containing type.
2467 Otherwise, adjust offset to the byte containing the first
2468 bit. Assume that the address, offset, and embedded offset
2469 are sufficiently aligned. */
2470 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2471 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2473 v
= allocate_value_lazy (type
);
2474 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2475 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2476 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2477 v
->bitpos
= bitpos
% container_bitsize
;
2479 v
->bitpos
= bitpos
% 8;
2480 v
->offset
= (value_embedded_offset (arg1
)
2482 + (bitpos
- v
->bitpos
) / 8);
2484 value_incref (v
->parent
);
2485 if (!value_lazy (arg1
))
2486 value_fetch_lazy (v
);
2488 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2490 /* This field is actually a base subobject, so preserve the
2491 entire object's contents for later references to virtual
2494 /* Lazy register values with offsets are not supported. */
2495 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2496 value_fetch_lazy (arg1
);
2498 if (value_lazy (arg1
))
2499 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2502 v
= allocate_value (value_enclosing_type (arg1
));
2503 value_contents_copy_raw (v
, 0, arg1
, 0,
2504 TYPE_LENGTH (value_enclosing_type (arg1
)));
2507 v
->offset
= value_offset (arg1
);
2508 v
->embedded_offset
= (offset
+ value_embedded_offset (arg1
)
2509 + TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8);
2513 /* Plain old data member */
2514 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2516 /* Lazy register values with offsets are not supported. */
2517 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2518 value_fetch_lazy (arg1
);
2520 if (value_lazy (arg1
))
2521 v
= allocate_value_lazy (type
);
2524 v
= allocate_value (type
);
2525 value_contents_copy_raw (v
, value_embedded_offset (v
),
2526 arg1
, value_embedded_offset (arg1
) + offset
,
2527 TYPE_LENGTH (type
));
2529 v
->offset
= (value_offset (arg1
) + offset
2530 + value_embedded_offset (arg1
));
2532 set_value_component_location (v
, arg1
);
2533 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2534 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2538 /* Given a value ARG1 of a struct or union type,
2539 extract and return the value of one of its (non-static) fields.
2540 FIELDNO says which field. */
2543 value_field (struct value
*arg1
, int fieldno
)
2545 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2548 /* Return a non-virtual function as a value.
2549 F is the list of member functions which contains the desired method.
2550 J is an index into F which provides the desired method.
2552 We only use the symbol for its address, so be happy with either a
2553 full symbol or a minimal symbol. */
2556 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2557 int j
, struct type
*type
,
2561 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2562 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2564 struct minimal_symbol
*msym
;
2566 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2573 gdb_assert (sym
== NULL
);
2574 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2579 v
= allocate_value (ftype
);
2582 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2586 /* The minimal symbol might point to a function descriptor;
2587 resolve it to the actual code address instead. */
2588 struct objfile
*objfile
= msymbol_objfile (msym
);
2589 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2591 set_value_address (v
,
2592 gdbarch_convert_from_func_ptr_addr
2593 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2598 if (type
!= value_type (*arg1p
))
2599 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2600 value_addr (*arg1p
)));
2602 /* Move the `this' pointer according to the offset.
2603 VALUE_OFFSET (*arg1p) += offset; */
2611 /* Helper function for both unpack_value_bits_as_long and
2612 unpack_bits_as_long. See those functions for more details on the
2613 interface; the only difference is that this function accepts either
2614 a NULL or a non-NULL ORIGINAL_VALUE. */
2617 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2618 int embedded_offset
, int bitpos
, int bitsize
,
2619 const struct value
*original_value
,
2622 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2629 /* Read the minimum number of bytes required; there may not be
2630 enough bytes to read an entire ULONGEST. */
2631 CHECK_TYPEDEF (field_type
);
2633 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2635 bytes_read
= TYPE_LENGTH (field_type
);
2637 read_offset
= bitpos
/ 8;
2639 if (original_value
!= NULL
2640 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2644 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2645 bytes_read
, byte_order
);
2647 /* Extract bits. See comment above. */
2649 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2650 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2652 lsbcount
= (bitpos
% 8);
2655 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2656 If the field is signed, and is negative, then sign extend. */
2658 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2660 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2662 if (!TYPE_UNSIGNED (field_type
))
2664 if (val
& (valmask
^ (valmask
>> 1)))
2675 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2676 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2677 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2678 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2681 Returns false if the value contents are unavailable, otherwise
2682 returns true, indicating a valid value has been stored in *RESULT.
2684 Extracting bits depends on endianness of the machine. Compute the
2685 number of least significant bits to discard. For big endian machines,
2686 we compute the total number of bits in the anonymous object, subtract
2687 off the bit count from the MSB of the object to the MSB of the
2688 bitfield, then the size of the bitfield, which leaves the LSB discard
2689 count. For little endian machines, the discard count is simply the
2690 number of bits from the LSB of the anonymous object to the LSB of the
2693 If the field is signed, we also do sign extension. */
2696 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2697 int embedded_offset
, int bitpos
, int bitsize
,
2698 const struct value
*original_value
,
2701 gdb_assert (original_value
!= NULL
);
2703 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2704 bitpos
, bitsize
, original_value
, result
);
2708 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2709 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2710 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2714 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2715 int embedded_offset
, int fieldno
,
2716 const struct value
*val
, LONGEST
*result
)
2718 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2719 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2720 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2722 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2723 bitpos
, bitsize
, val
,
2727 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2728 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2729 ORIGINAL_VALUE, which must not be NULL. See
2730 unpack_value_bits_as_long for more details. */
2733 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2734 int embedded_offset
, int fieldno
,
2735 const struct value
*val
, LONGEST
*result
)
2737 gdb_assert (val
!= NULL
);
2739 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2740 fieldno
, val
, result
);
2743 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2744 object at VALADDR. See unpack_value_bits_as_long for more details.
2745 This function differs from unpack_value_field_as_long in that it
2746 operates without a struct value object. */
2749 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2753 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2757 /* Return a new value with type TYPE, which is FIELDNO field of the
2758 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2759 of VAL. If the VAL's contents required to extract the bitfield
2760 from are unavailable, the new value is correspondingly marked as
2764 value_field_bitfield (struct type
*type
, int fieldno
,
2765 const gdb_byte
*valaddr
,
2766 int embedded_offset
, const struct value
*val
)
2770 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2773 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2774 struct value
*retval
= allocate_value (field_type
);
2775 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2780 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2784 /* Modify the value of a bitfield. ADDR points to a block of memory in
2785 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2786 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2787 indicate which bits (in target bit order) comprise the bitfield.
2788 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2789 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2792 modify_field (struct type
*type
, gdb_byte
*addr
,
2793 LONGEST fieldval
, int bitpos
, int bitsize
)
2795 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2797 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2800 /* Normalize BITPOS. */
2804 /* If a negative fieldval fits in the field in question, chop
2805 off the sign extension bits. */
2806 if ((~fieldval
& ~(mask
>> 1)) == 0)
2809 /* Warn if value is too big to fit in the field in question. */
2810 if (0 != (fieldval
& ~mask
))
2812 /* FIXME: would like to include fieldval in the message, but
2813 we don't have a sprintf_longest. */
2814 warning (_("Value does not fit in %d bits."), bitsize
);
2816 /* Truncate it, otherwise adjoining fields may be corrupted. */
2820 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2821 false valgrind reports. */
2823 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2824 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2826 /* Shifting for bit field depends on endianness of the target machine. */
2827 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2828 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2830 oword
&= ~(mask
<< bitpos
);
2831 oword
|= fieldval
<< bitpos
;
2833 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2836 /* Pack NUM into BUF using a target format of TYPE. */
2839 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2841 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2844 type
= check_typedef (type
);
2845 len
= TYPE_LENGTH (type
);
2847 switch (TYPE_CODE (type
))
2850 case TYPE_CODE_CHAR
:
2851 case TYPE_CODE_ENUM
:
2852 case TYPE_CODE_FLAGS
:
2853 case TYPE_CODE_BOOL
:
2854 case TYPE_CODE_RANGE
:
2855 case TYPE_CODE_MEMBERPTR
:
2856 store_signed_integer (buf
, len
, byte_order
, num
);
2861 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2865 error (_("Unexpected type (%d) encountered for integer constant."),
2871 /* Pack NUM into BUF using a target format of TYPE. */
2874 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2877 enum bfd_endian byte_order
;
2879 type
= check_typedef (type
);
2880 len
= TYPE_LENGTH (type
);
2881 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2883 switch (TYPE_CODE (type
))
2886 case TYPE_CODE_CHAR
:
2887 case TYPE_CODE_ENUM
:
2888 case TYPE_CODE_FLAGS
:
2889 case TYPE_CODE_BOOL
:
2890 case TYPE_CODE_RANGE
:
2891 case TYPE_CODE_MEMBERPTR
:
2892 store_unsigned_integer (buf
, len
, byte_order
, num
);
2897 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2901 error (_("Unexpected type (%d) encountered "
2902 "for unsigned integer constant."),
2908 /* Convert C numbers into newly allocated values. */
2911 value_from_longest (struct type
*type
, LONGEST num
)
2913 struct value
*val
= allocate_value (type
);
2915 pack_long (value_contents_raw (val
), type
, num
);
2920 /* Convert C unsigned numbers into newly allocated values. */
2923 value_from_ulongest (struct type
*type
, ULONGEST num
)
2925 struct value
*val
= allocate_value (type
);
2927 pack_unsigned_long (value_contents_raw (val
), type
, num
);
2933 /* Create a value representing a pointer of type TYPE to the address
2936 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
2938 struct value
*val
= allocate_value (type
);
2940 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
2945 /* Create a value of type TYPE whose contents come from VALADDR, if it
2946 is non-null, and whose memory address (in the inferior) is
2950 value_from_contents_and_address (struct type
*type
,
2951 const gdb_byte
*valaddr
,
2956 if (valaddr
== NULL
)
2957 v
= allocate_value_lazy (type
);
2960 v
= allocate_value (type
);
2961 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
2963 set_value_address (v
, address
);
2964 VALUE_LVAL (v
) = lval_memory
;
2968 /* Create a value of type TYPE holding the contents CONTENTS.
2969 The new value is `not_lval'. */
2972 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
2974 struct value
*result
;
2976 result
= allocate_value (type
);
2977 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
2982 value_from_double (struct type
*type
, DOUBLEST num
)
2984 struct value
*val
= allocate_value (type
);
2985 struct type
*base_type
= check_typedef (type
);
2986 enum type_code code
= TYPE_CODE (base_type
);
2988 if (code
== TYPE_CODE_FLT
)
2990 store_typed_floating (value_contents_raw (val
), base_type
, num
);
2993 error (_("Unexpected type encountered for floating constant."));
2999 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3001 struct value
*val
= allocate_value (type
);
3003 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3007 /* Extract a value from the history file. Input will be of the form
3008 $digits or $$digits. See block comment above 'write_dollar_variable'
3012 value_from_history_ref (char *h
, char **endp
)
3024 /* Find length of numeral string. */
3025 for (; isdigit (h
[len
]); len
++)
3028 /* Make sure numeral string is not part of an identifier. */
3029 if (h
[len
] == '_' || isalpha (h
[len
]))
3032 /* Now collect the index value. */
3037 /* For some bizarre reason, "$$" is equivalent to "$$1",
3038 rather than to "$$0" as it ought to be! */
3043 index
= -strtol (&h
[2], endp
, 10);
3049 /* "$" is equivalent to "$0". */
3054 index
= strtol (&h
[1], endp
, 10);
3057 return access_value_history (index
);
3061 coerce_ref (struct value
*arg
)
3063 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3065 if (TYPE_CODE (value_type_arg_tmp
) == TYPE_CODE_REF
)
3066 arg
= value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp
),
3067 unpack_pointer (value_type (arg
),
3068 value_contents (arg
)));
3073 coerce_array (struct value
*arg
)
3077 arg
= coerce_ref (arg
);
3078 type
= check_typedef (value_type (arg
));
3080 switch (TYPE_CODE (type
))
3082 case TYPE_CODE_ARRAY
:
3083 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3084 arg
= value_coerce_array (arg
);
3086 case TYPE_CODE_FUNC
:
3087 arg
= value_coerce_function (arg
);
3094 /* Return true if the function returning the specified type is using
3095 the convention of returning structures in memory (passing in the
3096 address as a hidden first parameter). */
3099 using_struct_return (struct gdbarch
*gdbarch
,
3100 struct type
*func_type
, struct type
*value_type
)
3102 enum type_code code
= TYPE_CODE (value_type
);
3104 if (code
== TYPE_CODE_ERROR
)
3105 error (_("Function return type unknown."));
3107 if (code
== TYPE_CODE_VOID
)
3108 /* A void return value is never in memory. See also corresponding
3109 code in "print_return_value". */
3112 /* Probe the architecture for the return-value convention. */
3113 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3115 != RETURN_VALUE_REGISTER_CONVENTION
);
3118 /* Set the initialized field in a value struct. */
3121 set_value_initialized (struct value
*val
, int status
)
3123 val
->initialized
= status
;
3126 /* Return the initialized field in a value struct. */
3129 value_initialized (struct value
*val
)
3131 return val
->initialized
;
3135 _initialize_values (void)
3137 add_cmd ("convenience", no_class
, show_convenience
, _("\
3138 Debugger convenience (\"$foo\") variables.\n\
3139 These variables are created when you assign them values;\n\
3140 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3142 A few convenience variables are given values automatically:\n\
3143 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3144 \"$__\" holds the contents of the last address examined with \"x\"."),
3147 add_cmd ("values", no_set_class
, show_values
, _("\
3148 Elements of value history around item number IDX (or last ten)."),
3151 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3152 Initialize a convenience variable if necessary.\n\
3153 init-if-undefined VARIABLE = EXPRESSION\n\
3154 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3155 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3156 VARIABLE is already initialized."));
3158 add_prefix_cmd ("function", no_class
, function_command
, _("\
3159 Placeholder command for showing help on convenience functions."),
3160 &functionlist
, "function ", 0, &cmdlist
);