1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2013 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 3 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, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
22 #include "gdb_string.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
45 #include "user-regs.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
;
172 /* Note that the fields in this structure are arranged to save a bit
177 /* Type of value; either not an lval, or one of the various
178 different possible kinds of lval. */
181 /* Is it modifiable? Only relevant if lval != not_lval. */
182 unsigned int modifiable
: 1;
184 /* If zero, contents of this value are in the contents field. If
185 nonzero, contents are in inferior. If the lval field is lval_memory,
186 the contents are in inferior memory at location.address plus offset.
187 The lval field may also be lval_register.
189 WARNING: This field is used by the code which handles watchpoints
190 (see breakpoint.c) to decide whether a particular value can be
191 watched by hardware watchpoints. If the lazy flag is set for
192 some member of a value chain, it is assumed that this member of
193 the chain doesn't need to be watched as part of watching the
194 value itself. This is how GDB avoids watching the entire struct
195 or array when the user wants to watch a single struct member or
196 array element. If you ever change the way lazy flag is set and
197 reset, be sure to consider this use as well! */
198 unsigned int lazy
: 1;
200 /* If nonzero, this is the value of a variable which does not
201 actually exist in the program. */
202 unsigned int optimized_out
: 1;
204 /* If value is a variable, is it initialized or not. */
205 unsigned int initialized
: 1;
207 /* If value is from the stack. If this is set, read_stack will be
208 used instead of read_memory to enable extra caching. */
209 unsigned int stack
: 1;
211 /* If the value has been released. */
212 unsigned int released
: 1;
214 /* Location of value (if lval). */
217 /* If lval == lval_memory, this is the address in the inferior.
218 If lval == lval_register, this is the byte offset into the
219 registers structure. */
222 /* Pointer to internal variable. */
223 struct internalvar
*internalvar
;
225 /* If lval == lval_computed, this is a set of function pointers
226 to use to access and describe the value, and a closure pointer
230 /* Functions to call. */
231 const struct lval_funcs
*funcs
;
233 /* Closure for those functions to use. */
238 /* Describes offset of a value within lval of a structure in bytes.
239 If lval == lval_memory, this is an offset to the address. If
240 lval == lval_register, this is a further offset from
241 location.address within the registers structure. Note also the
242 member embedded_offset below. */
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value
*parent
;
265 /* Frame register value is relative to. This will be described in
266 the lval enum above as "lval_register". */
267 struct frame_id frame_id
;
269 /* Type of the value. */
272 /* If a value represents a C++ object, then the `type' field gives
273 the object's compile-time type. If the object actually belongs
274 to some class derived from `type', perhaps with other base
275 classes and additional members, then `type' is just a subobject
276 of the real thing, and the full object is probably larger than
277 `type' would suggest.
279 If `type' is a dynamic class (i.e. one with a vtable), then GDB
280 can actually determine the object's run-time type by looking at
281 the run-time type information in the vtable. When this
282 information is available, we may elect to read in the entire
283 object, for several reasons:
285 - When printing the value, the user would probably rather see the
286 full object, not just the limited portion apparent from the
289 - If `type' has virtual base classes, then even printing `type'
290 alone may require reaching outside the `type' portion of the
291 object to wherever the virtual base class has been stored.
293 When we store the entire object, `enclosing_type' is the run-time
294 type -- the complete object -- and `embedded_offset' is the
295 offset of `type' within that larger type, in bytes. The
296 value_contents() macro takes `embedded_offset' into account, so
297 most GDB code continues to see the `type' portion of the value,
298 just as the inferior would.
300 If `type' is a pointer to an object, then `enclosing_type' is a
301 pointer to the object's run-time type, and `pointed_to_offset' is
302 the offset in bytes from the full object to the pointed-to object
303 -- that is, the value `embedded_offset' would have if we followed
304 the pointer and fetched the complete object. (I don't really see
305 the point. Why not just determine the run-time type when you
306 indirect, and avoid the special case? The contents don't matter
307 until you indirect anyway.)
309 If we're not doing anything fancy, `enclosing_type' is equal to
310 `type', and `embedded_offset' is zero, so everything works
312 struct type
*enclosing_type
;
314 int pointed_to_offset
;
316 /* Values are stored in a chain, so that they can be deleted easily
317 over calls to the inferior. Values assigned to internal
318 variables, put into the value history or exposed to Python are
319 taken off this list. */
322 /* Register number if the value is from a register. */
325 /* Actual contents of the value. Target byte-order. NULL or not
326 valid if lazy is nonzero. */
329 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
330 rather than available, since the common and default case is for a
331 value to be available. This is filled in at value read time. */
332 VEC(range_s
) *unavailable
;
336 value_bytes_available (const struct value
*value
, int offset
, int length
)
338 gdb_assert (!value
->lazy
);
340 return !ranges_contain (value
->unavailable
, offset
, length
);
344 value_entirely_available (struct value
*value
)
346 /* We can only tell whether the whole value is available when we try
349 value_fetch_lazy (value
);
351 if (VEC_empty (range_s
, value
->unavailable
))
357 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
362 /* Insert the range sorted. If there's overlap or the new range
363 would be contiguous with an existing range, merge. */
365 newr
.offset
= offset
;
366 newr
.length
= length
;
368 /* Do a binary search for the position the given range would be
369 inserted if we only considered the starting OFFSET of ranges.
370 Call that position I. Since we also have LENGTH to care for
371 (this is a range afterall), we need to check if the _previous_
372 range overlaps the I range. E.g., calling R the new range:
374 #1 - overlaps with previous
378 |---| |---| |------| ... |--|
383 In the case #1 above, the binary search would return `I=1',
384 meaning, this OFFSET should be inserted at position 1, and the
385 current position 1 should be pushed further (and become 2). But,
386 note that `0' overlaps with R, so we want to merge them.
388 A similar consideration needs to be taken if the new range would
389 be contiguous with the previous range:
391 #2 - contiguous with previous
395 |--| |---| |------| ... |--|
400 If there's no overlap with the previous range, as in:
402 #3 - not overlapping and not contiguous
406 |--| |---| |------| ... |--|
413 #4 - R is the range with lowest offset
417 |--| |---| |------| ... |--|
422 ... we just push the new range to I.
424 All the 4 cases above need to consider that the new range may
425 also overlap several of the ranges that follow, or that R may be
426 contiguous with the following range, and merge. E.g.,
428 #5 - overlapping following ranges
431 |------------------------|
432 |--| |---| |------| ... |--|
441 |--| |---| |------| ... |--|
448 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
451 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
453 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
456 ULONGEST l
= min (bef
->offset
, offset
);
457 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
463 else if (offset
== bef
->offset
+ bef
->length
)
466 bef
->length
+= length
;
472 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
478 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
481 /* Check whether the ranges following the one we've just added or
482 touched can be folded in (#5 above). */
483 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
490 /* Get the range we just touched. */
491 t
= VEC_index (range_s
, value
->unavailable
, i
);
495 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
496 if (r
->offset
<= t
->offset
+ t
->length
)
500 l
= min (t
->offset
, r
->offset
);
501 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
510 /* If we couldn't merge this one, we won't be able to
511 merge following ones either, since the ranges are
512 always sorted by OFFSET. */
517 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
521 /* Find the first range in RANGES that overlaps the range defined by
522 OFFSET and LENGTH, starting at element POS in the RANGES vector,
523 Returns the index into RANGES where such overlapping range was
524 found, or -1 if none was found. */
527 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
528 int offset
, int length
)
533 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
534 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
541 value_available_contents_eq (const struct value
*val1
, int offset1
,
542 const struct value
*val2
, int offset2
,
545 int idx1
= 0, idx2
= 0;
547 /* See function description in value.h. */
548 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
556 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
558 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
561 /* The usual case is for both values to be completely available. */
562 if (idx1
== -1 && idx2
== -1)
563 return (memcmp (val1
->contents
+ offset1
,
564 val2
->contents
+ offset2
,
566 /* The contents only match equal if the available set matches as
568 else if (idx1
== -1 || idx2
== -1)
571 gdb_assert (idx1
!= -1 && idx2
!= -1);
573 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
574 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
576 /* Get the unavailable windows intersected by the incoming
577 ranges. The first and last ranges that overlap the argument
578 range may be wider than said incoming arguments ranges. */
579 l1
= max (offset1
, r1
->offset
);
580 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
582 l2
= max (offset2
, r2
->offset
);
583 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
585 /* Make them relative to the respective start offsets, so we can
586 compare them for equality. */
593 /* Different availability, no match. */
594 if (l1
!= l2
|| h1
!= h2
)
597 /* Compare the _available_ contents. */
598 if (memcmp (val1
->contents
+ offset1
,
599 val2
->contents
+ offset2
,
611 /* Prototypes for local functions. */
613 static void show_values (char *, int);
615 static void show_convenience (char *, int);
618 /* The value-history records all the values printed
619 by print commands during this session. Each chunk
620 records 60 consecutive values. The first chunk on
621 the chain records the most recent values.
622 The total number of values is in value_history_count. */
624 #define VALUE_HISTORY_CHUNK 60
626 struct value_history_chunk
628 struct value_history_chunk
*next
;
629 struct value
*values
[VALUE_HISTORY_CHUNK
];
632 /* Chain of chunks now in use. */
634 static struct value_history_chunk
*value_history_chain
;
636 static int value_history_count
; /* Abs number of last entry stored. */
639 /* List of all value objects currently allocated
640 (except for those released by calls to release_value)
641 This is so they can be freed after each command. */
643 static struct value
*all_values
;
645 /* Allocate a lazy value for type TYPE. Its actual content is
646 "lazily" allocated too: the content field of the return value is
647 NULL; it will be allocated when it is fetched from the target. */
650 allocate_value_lazy (struct type
*type
)
654 /* Call check_typedef on our type to make sure that, if TYPE
655 is a TYPE_CODE_TYPEDEF, its length is set to the length
656 of the target type instead of zero. However, we do not
657 replace the typedef type by the target type, because we want
658 to keep the typedef in order to be able to set the VAL's type
659 description correctly. */
660 check_typedef (type
);
662 val
= (struct value
*) xzalloc (sizeof (struct value
));
663 val
->contents
= NULL
;
664 val
->next
= all_values
;
667 val
->enclosing_type
= type
;
668 VALUE_LVAL (val
) = not_lval
;
669 val
->location
.address
= 0;
670 VALUE_FRAME_ID (val
) = null_frame_id
;
674 VALUE_REGNUM (val
) = -1;
676 val
->optimized_out
= 0;
677 val
->embedded_offset
= 0;
678 val
->pointed_to_offset
= 0;
680 val
->initialized
= 1; /* Default to initialized. */
682 /* Values start out on the all_values chain. */
683 val
->reference_count
= 1;
688 /* Allocate the contents of VAL if it has not been allocated yet. */
691 allocate_value_contents (struct value
*val
)
694 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
697 /* Allocate a value and its contents for type TYPE. */
700 allocate_value (struct type
*type
)
702 struct value
*val
= allocate_value_lazy (type
);
704 allocate_value_contents (val
);
709 /* Allocate a value that has the correct length
710 for COUNT repetitions of type TYPE. */
713 allocate_repeat_value (struct type
*type
, int count
)
715 int low_bound
= current_language
->string_lower_bound
; /* ??? */
716 /* FIXME-type-allocation: need a way to free this type when we are
718 struct type
*array_type
719 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
721 return allocate_value (array_type
);
725 allocate_computed_value (struct type
*type
,
726 const struct lval_funcs
*funcs
,
729 struct value
*v
= allocate_value_lazy (type
);
731 VALUE_LVAL (v
) = lval_computed
;
732 v
->location
.computed
.funcs
= funcs
;
733 v
->location
.computed
.closure
= closure
;
738 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
741 allocate_optimized_out_value (struct type
*type
)
743 struct value
*retval
= allocate_value_lazy (type
);
745 set_value_optimized_out (retval
, 1);
750 /* Accessor methods. */
753 value_next (struct value
*value
)
759 value_type (const struct value
*value
)
764 deprecated_set_value_type (struct value
*value
, struct type
*type
)
770 value_offset (const struct value
*value
)
772 return value
->offset
;
775 set_value_offset (struct value
*value
, int offset
)
777 value
->offset
= offset
;
781 value_bitpos (const struct value
*value
)
783 return value
->bitpos
;
786 set_value_bitpos (struct value
*value
, int bit
)
792 value_bitsize (const struct value
*value
)
794 return value
->bitsize
;
797 set_value_bitsize (struct value
*value
, int bit
)
799 value
->bitsize
= bit
;
803 value_parent (struct value
*value
)
805 return value
->parent
;
811 set_value_parent (struct value
*value
, struct value
*parent
)
813 struct value
*old
= value
->parent
;
815 value
->parent
= parent
;
817 value_incref (parent
);
822 value_contents_raw (struct value
*value
)
824 allocate_value_contents (value
);
825 return value
->contents
+ value
->embedded_offset
;
829 value_contents_all_raw (struct value
*value
)
831 allocate_value_contents (value
);
832 return value
->contents
;
836 value_enclosing_type (struct value
*value
)
838 return value
->enclosing_type
;
841 /* Look at value.h for description. */
844 value_actual_type (struct value
*value
, int resolve_simple_types
,
845 int *real_type_found
)
847 struct value_print_options opts
;
850 get_user_print_options (&opts
);
853 *real_type_found
= 0;
854 result
= value_type (value
);
855 if (opts
.objectprint
)
857 /* If result's target type is TYPE_CODE_STRUCT, proceed to
858 fetch its rtti type. */
859 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
860 || TYPE_CODE (result
) == TYPE_CODE_REF
)
861 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
864 struct type
*real_type
;
866 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
870 *real_type_found
= 1;
874 else if (resolve_simple_types
)
877 *real_type_found
= 1;
878 result
= value_enclosing_type (value
);
886 require_not_optimized_out (const struct value
*value
)
888 if (value
->optimized_out
)
889 error (_("value has been optimized out"));
893 require_available (const struct value
*value
)
895 if (!VEC_empty (range_s
, value
->unavailable
))
896 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
900 value_contents_for_printing (struct value
*value
)
903 value_fetch_lazy (value
);
904 return value
->contents
;
908 value_contents_for_printing_const (const struct value
*value
)
910 gdb_assert (!value
->lazy
);
911 return value
->contents
;
915 value_contents_all (struct value
*value
)
917 const gdb_byte
*result
= value_contents_for_printing (value
);
918 require_not_optimized_out (value
);
919 require_available (value
);
923 /* Copy LENGTH bytes of SRC value's (all) contents
924 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
925 contents, starting at DST_OFFSET. If unavailable contents are
926 being copied from SRC, the corresponding DST contents are marked
927 unavailable accordingly. Neither DST nor SRC may be lazy
930 It is assumed the contents of DST in the [DST_OFFSET,
931 DST_OFFSET+LENGTH) range are wholly available. */
934 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
935 struct value
*src
, int src_offset
, int length
)
940 /* A lazy DST would make that this copy operation useless, since as
941 soon as DST's contents were un-lazied (by a later value_contents
942 call, say), the contents would be overwritten. A lazy SRC would
943 mean we'd be copying garbage. */
944 gdb_assert (!dst
->lazy
&& !src
->lazy
);
946 /* The overwritten DST range gets unavailability ORed in, not
947 replaced. Make sure to remember to implement replacing if it
948 turns out actually necessary. */
949 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
952 memcpy (value_contents_all_raw (dst
) + dst_offset
,
953 value_contents_all_raw (src
) + src_offset
,
956 /* Copy the meta-data, adjusted. */
957 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
961 l
= max (r
->offset
, src_offset
);
962 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
965 mark_value_bytes_unavailable (dst
,
966 dst_offset
+ (l
- src_offset
),
971 /* Copy LENGTH bytes of SRC value's (all) contents
972 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
973 (all) contents, starting at DST_OFFSET. If unavailable contents
974 are being copied from SRC, the corresponding DST contents are
975 marked unavailable accordingly. DST must not be lazy. If SRC is
976 lazy, it will be fetched now. If SRC is not valid (is optimized
977 out), an error is thrown.
979 It is assumed the contents of DST in the [DST_OFFSET,
980 DST_OFFSET+LENGTH) range are wholly available. */
983 value_contents_copy (struct value
*dst
, int dst_offset
,
984 struct value
*src
, int src_offset
, int length
)
986 require_not_optimized_out (src
);
989 value_fetch_lazy (src
);
991 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
995 value_lazy (struct value
*value
)
1001 set_value_lazy (struct value
*value
, int val
)
1007 value_stack (struct value
*value
)
1009 return value
->stack
;
1013 set_value_stack (struct value
*value
, int val
)
1019 value_contents (struct value
*value
)
1021 const gdb_byte
*result
= value_contents_writeable (value
);
1022 require_not_optimized_out (value
);
1023 require_available (value
);
1028 value_contents_writeable (struct value
*value
)
1031 value_fetch_lazy (value
);
1032 return value_contents_raw (value
);
1035 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1036 this function is different from value_equal; in C the operator ==
1037 can return 0 even if the two values being compared are equal. */
1040 value_contents_equal (struct value
*val1
, struct value
*val2
)
1045 type1
= check_typedef (value_type (val1
));
1046 type2
= check_typedef (value_type (val2
));
1047 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1050 return (memcmp (value_contents (val1
), value_contents (val2
),
1051 TYPE_LENGTH (type1
)) == 0);
1055 value_optimized_out (struct value
*value
)
1057 /* We can only know if a value is optimized out once we have tried to
1059 if (!value
->optimized_out
&& value
->lazy
)
1060 value_fetch_lazy (value
);
1062 return value
->optimized_out
;
1066 set_value_optimized_out (struct value
*value
, int val
)
1068 value
->optimized_out
= val
;
1072 value_entirely_optimized_out (const struct value
*value
)
1074 if (!value
->optimized_out
)
1076 if (value
->lval
!= lval_computed
1077 || !value
->location
.computed
.funcs
->check_any_valid
)
1079 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1083 value_bits_valid (const struct value
*value
, int offset
, int length
)
1085 if (!value
->optimized_out
)
1087 if (value
->lval
!= lval_computed
1088 || !value
->location
.computed
.funcs
->check_validity
)
1090 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1095 value_bits_synthetic_pointer (const struct value
*value
,
1096 int offset
, int length
)
1098 if (value
->lval
!= lval_computed
1099 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1101 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1107 value_embedded_offset (struct value
*value
)
1109 return value
->embedded_offset
;
1113 set_value_embedded_offset (struct value
*value
, int val
)
1115 value
->embedded_offset
= val
;
1119 value_pointed_to_offset (struct value
*value
)
1121 return value
->pointed_to_offset
;
1125 set_value_pointed_to_offset (struct value
*value
, int val
)
1127 value
->pointed_to_offset
= val
;
1130 const struct lval_funcs
*
1131 value_computed_funcs (const struct value
*v
)
1133 gdb_assert (value_lval_const (v
) == lval_computed
);
1135 return v
->location
.computed
.funcs
;
1139 value_computed_closure (const struct value
*v
)
1141 gdb_assert (v
->lval
== lval_computed
);
1143 return v
->location
.computed
.closure
;
1147 deprecated_value_lval_hack (struct value
*value
)
1149 return &value
->lval
;
1153 value_lval_const (const struct value
*value
)
1159 value_address (const struct value
*value
)
1161 if (value
->lval
== lval_internalvar
1162 || value
->lval
== lval_internalvar_component
)
1164 if (value
->parent
!= NULL
)
1165 return value_address (value
->parent
) + value
->offset
;
1167 return value
->location
.address
+ value
->offset
;
1171 value_raw_address (struct value
*value
)
1173 if (value
->lval
== lval_internalvar
1174 || value
->lval
== lval_internalvar_component
)
1176 return value
->location
.address
;
1180 set_value_address (struct value
*value
, CORE_ADDR addr
)
1182 gdb_assert (value
->lval
!= lval_internalvar
1183 && value
->lval
!= lval_internalvar_component
);
1184 value
->location
.address
= addr
;
1187 struct internalvar
**
1188 deprecated_value_internalvar_hack (struct value
*value
)
1190 return &value
->location
.internalvar
;
1194 deprecated_value_frame_id_hack (struct value
*value
)
1196 return &value
->frame_id
;
1200 deprecated_value_regnum_hack (struct value
*value
)
1202 return &value
->regnum
;
1206 deprecated_value_modifiable (struct value
*value
)
1208 return value
->modifiable
;
1211 /* Return a mark in the value chain. All values allocated after the
1212 mark is obtained (except for those released) are subject to being freed
1213 if a subsequent value_free_to_mark is passed the mark. */
1220 /* Take a reference to VAL. VAL will not be deallocated until all
1221 references are released. */
1224 value_incref (struct value
*val
)
1226 val
->reference_count
++;
1229 /* Release a reference to VAL, which was acquired with value_incref.
1230 This function is also called to deallocate values from the value
1234 value_free (struct value
*val
)
1238 gdb_assert (val
->reference_count
> 0);
1239 val
->reference_count
--;
1240 if (val
->reference_count
> 0)
1243 /* If there's an associated parent value, drop our reference to
1245 if (val
->parent
!= NULL
)
1246 value_free (val
->parent
);
1248 if (VALUE_LVAL (val
) == lval_computed
)
1250 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1252 if (funcs
->free_closure
)
1253 funcs
->free_closure (val
);
1256 xfree (val
->contents
);
1257 VEC_free (range_s
, val
->unavailable
);
1262 /* Free all values allocated since MARK was obtained by value_mark
1263 (except for those released). */
1265 value_free_to_mark (struct value
*mark
)
1270 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1279 /* Free all the values that have been allocated (except for those released).
1280 Call after each command, successful or not.
1281 In practice this is called before each command, which is sufficient. */
1284 free_all_values (void)
1289 for (val
= all_values
; val
; val
= next
)
1299 /* Frees all the elements in a chain of values. */
1302 free_value_chain (struct value
*v
)
1308 next
= value_next (v
);
1313 /* Remove VAL from the chain all_values
1314 so it will not be freed automatically. */
1317 release_value (struct value
*val
)
1321 if (all_values
== val
)
1323 all_values
= val
->next
;
1329 for (v
= all_values
; v
; v
= v
->next
)
1333 v
->next
= val
->next
;
1341 /* If the value is not already released, release it.
1342 If the value is already released, increment its reference count.
1343 That is, this function ensures that the value is released from the
1344 value chain and that the caller owns a reference to it. */
1347 release_value_or_incref (struct value
*val
)
1352 release_value (val
);
1355 /* Release all values up to mark */
1357 value_release_to_mark (struct value
*mark
)
1362 for (val
= next
= all_values
; next
; next
= next
->next
)
1364 if (next
->next
== mark
)
1366 all_values
= next
->next
;
1376 /* Return a copy of the value ARG.
1377 It contains the same contents, for same memory address,
1378 but it's a different block of storage. */
1381 value_copy (struct value
*arg
)
1383 struct type
*encl_type
= value_enclosing_type (arg
);
1386 if (value_lazy (arg
))
1387 val
= allocate_value_lazy (encl_type
);
1389 val
= allocate_value (encl_type
);
1390 val
->type
= arg
->type
;
1391 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1392 val
->location
= arg
->location
;
1393 val
->offset
= arg
->offset
;
1394 val
->bitpos
= arg
->bitpos
;
1395 val
->bitsize
= arg
->bitsize
;
1396 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1397 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1398 val
->lazy
= arg
->lazy
;
1399 val
->optimized_out
= arg
->optimized_out
;
1400 val
->embedded_offset
= value_embedded_offset (arg
);
1401 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1402 val
->modifiable
= arg
->modifiable
;
1403 if (!value_lazy (val
))
1405 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1406 TYPE_LENGTH (value_enclosing_type (arg
)));
1409 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1410 set_value_parent (val
, arg
->parent
);
1411 if (VALUE_LVAL (val
) == lval_computed
)
1413 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1415 if (funcs
->copy_closure
)
1416 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1421 /* Return a version of ARG that is non-lvalue. */
1424 value_non_lval (struct value
*arg
)
1426 if (VALUE_LVAL (arg
) != not_lval
)
1428 struct type
*enc_type
= value_enclosing_type (arg
);
1429 struct value
*val
= allocate_value (enc_type
);
1431 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1432 TYPE_LENGTH (enc_type
));
1433 val
->type
= arg
->type
;
1434 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1435 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1442 set_value_component_location (struct value
*component
,
1443 const struct value
*whole
)
1445 if (whole
->lval
== lval_internalvar
)
1446 VALUE_LVAL (component
) = lval_internalvar_component
;
1448 VALUE_LVAL (component
) = whole
->lval
;
1450 component
->location
= whole
->location
;
1451 if (whole
->lval
== lval_computed
)
1453 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1455 if (funcs
->copy_closure
)
1456 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1461 /* Access to the value history. */
1463 /* Record a new value in the value history.
1464 Returns the absolute history index of the entry.
1465 Result of -1 indicates the value was not saved; otherwise it is the
1466 value history index of this new item. */
1469 record_latest_value (struct value
*val
)
1473 /* We don't want this value to have anything to do with the inferior anymore.
1474 In particular, "set $1 = 50" should not affect the variable from which
1475 the value was taken, and fast watchpoints should be able to assume that
1476 a value on the value history never changes. */
1477 if (value_lazy (val
))
1478 value_fetch_lazy (val
);
1479 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1480 from. This is a bit dubious, because then *&$1 does not just return $1
1481 but the current contents of that location. c'est la vie... */
1482 val
->modifiable
= 0;
1483 release_value (val
);
1485 /* Here we treat value_history_count as origin-zero
1486 and applying to the value being stored now. */
1488 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1491 struct value_history_chunk
*new
1492 = (struct value_history_chunk
*)
1494 xmalloc (sizeof (struct value_history_chunk
));
1495 memset (new->values
, 0, sizeof new->values
);
1496 new->next
= value_history_chain
;
1497 value_history_chain
= new;
1500 value_history_chain
->values
[i
] = val
;
1502 /* Now we regard value_history_count as origin-one
1503 and applying to the value just stored. */
1505 return ++value_history_count
;
1508 /* Return a copy of the value in the history with sequence number NUM. */
1511 access_value_history (int num
)
1513 struct value_history_chunk
*chunk
;
1518 absnum
+= value_history_count
;
1523 error (_("The history is empty."));
1525 error (_("There is only one value in the history."));
1527 error (_("History does not go back to $$%d."), -num
);
1529 if (absnum
> value_history_count
)
1530 error (_("History has not yet reached $%d."), absnum
);
1534 /* Now absnum is always absolute and origin zero. */
1536 chunk
= value_history_chain
;
1537 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1538 - absnum
/ VALUE_HISTORY_CHUNK
;
1540 chunk
= chunk
->next
;
1542 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1546 show_values (char *num_exp
, int from_tty
)
1554 /* "show values +" should print from the stored position.
1555 "show values <exp>" should print around value number <exp>. */
1556 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1557 num
= parse_and_eval_long (num_exp
) - 5;
1561 /* "show values" means print the last 10 values. */
1562 num
= value_history_count
- 9;
1568 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1570 struct value_print_options opts
;
1572 val
= access_value_history (i
);
1573 printf_filtered (("$%d = "), i
);
1574 get_user_print_options (&opts
);
1575 value_print (val
, gdb_stdout
, &opts
);
1576 printf_filtered (("\n"));
1579 /* The next "show values +" should start after what we just printed. */
1582 /* Hitting just return after this command should do the same thing as
1583 "show values +". If num_exp is null, this is unnecessary, since
1584 "show values +" is not useful after "show values". */
1585 if (from_tty
&& num_exp
)
1592 /* Internal variables. These are variables within the debugger
1593 that hold values assigned by debugger commands.
1594 The user refers to them with a '$' prefix
1595 that does not appear in the variable names stored internally. */
1599 struct internalvar
*next
;
1602 /* We support various different kinds of content of an internal variable.
1603 enum internalvar_kind specifies the kind, and union internalvar_data
1604 provides the data associated with this particular kind. */
1606 enum internalvar_kind
1608 /* The internal variable is empty. */
1611 /* The value of the internal variable is provided directly as
1612 a GDB value object. */
1615 /* A fresh value is computed via a call-back routine on every
1616 access to the internal variable. */
1617 INTERNALVAR_MAKE_VALUE
,
1619 /* The internal variable holds a GDB internal convenience function. */
1620 INTERNALVAR_FUNCTION
,
1622 /* The variable holds an integer value. */
1623 INTERNALVAR_INTEGER
,
1625 /* The variable holds a GDB-provided string. */
1630 union internalvar_data
1632 /* A value object used with INTERNALVAR_VALUE. */
1633 struct value
*value
;
1635 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1638 /* The functions to call. */
1639 const struct internalvar_funcs
*functions
;
1641 /* The function's user-data. */
1645 /* The internal function used with INTERNALVAR_FUNCTION. */
1648 struct internal_function
*function
;
1649 /* True if this is the canonical name for the function. */
1653 /* An integer value used with INTERNALVAR_INTEGER. */
1656 /* If type is non-NULL, it will be used as the type to generate
1657 a value for this internal variable. If type is NULL, a default
1658 integer type for the architecture is used. */
1663 /* A string value used with INTERNALVAR_STRING. */
1668 static struct internalvar
*internalvars
;
1670 /* If the variable does not already exist create it and give it the
1671 value given. If no value is given then the default is zero. */
1673 init_if_undefined_command (char* args
, int from_tty
)
1675 struct internalvar
* intvar
;
1677 /* Parse the expression - this is taken from set_command(). */
1678 struct expression
*expr
= parse_expression (args
);
1679 register struct cleanup
*old_chain
=
1680 make_cleanup (free_current_contents
, &expr
);
1682 /* Validate the expression.
1683 Was the expression an assignment?
1684 Or even an expression at all? */
1685 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1686 error (_("Init-if-undefined requires an assignment expression."));
1688 /* Extract the variable from the parsed expression.
1689 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1690 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1691 error (_("The first parameter to init-if-undefined "
1692 "should be a GDB variable."));
1693 intvar
= expr
->elts
[2].internalvar
;
1695 /* Only evaluate the expression if the lvalue is void.
1696 This may still fail if the expresssion is invalid. */
1697 if (intvar
->kind
== INTERNALVAR_VOID
)
1698 evaluate_expression (expr
);
1700 do_cleanups (old_chain
);
1704 /* Look up an internal variable with name NAME. NAME should not
1705 normally include a dollar sign.
1707 If the specified internal variable does not exist,
1708 the return value is NULL. */
1710 struct internalvar
*
1711 lookup_only_internalvar (const char *name
)
1713 struct internalvar
*var
;
1715 for (var
= internalvars
; var
; var
= var
->next
)
1716 if (strcmp (var
->name
, name
) == 0)
1722 /* Complete NAME by comparing it to the names of internal variables.
1723 Returns a vector of newly allocated strings, or NULL if no matches
1727 complete_internalvar (const char *name
)
1729 VEC (char_ptr
) *result
= NULL
;
1730 struct internalvar
*var
;
1733 len
= strlen (name
);
1735 for (var
= internalvars
; var
; var
= var
->next
)
1736 if (strncmp (var
->name
, name
, len
) == 0)
1738 char *r
= xstrdup (var
->name
);
1740 VEC_safe_push (char_ptr
, result
, r
);
1746 /* Create an internal variable with name NAME and with a void value.
1747 NAME should not normally include a dollar sign. */
1749 struct internalvar
*
1750 create_internalvar (const char *name
)
1752 struct internalvar
*var
;
1754 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1755 var
->name
= concat (name
, (char *)NULL
);
1756 var
->kind
= INTERNALVAR_VOID
;
1757 var
->next
= internalvars
;
1762 /* Create an internal variable with name NAME and register FUN as the
1763 function that value_of_internalvar uses to create a value whenever
1764 this variable is referenced. NAME should not normally include a
1765 dollar sign. DATA is passed uninterpreted to FUN when it is
1766 called. CLEANUP, if not NULL, is called when the internal variable
1767 is destroyed. It is passed DATA as its only argument. */
1769 struct internalvar
*
1770 create_internalvar_type_lazy (const char *name
,
1771 const struct internalvar_funcs
*funcs
,
1774 struct internalvar
*var
= create_internalvar (name
);
1776 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1777 var
->u
.make_value
.functions
= funcs
;
1778 var
->u
.make_value
.data
= data
;
1782 /* See documentation in value.h. */
1785 compile_internalvar_to_ax (struct internalvar
*var
,
1786 struct agent_expr
*expr
,
1787 struct axs_value
*value
)
1789 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1790 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1793 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1794 var
->u
.make_value
.data
);
1798 /* Look up an internal variable with name NAME. NAME should not
1799 normally include a dollar sign.
1801 If the specified internal variable does not exist,
1802 one is created, with a void value. */
1804 struct internalvar
*
1805 lookup_internalvar (const char *name
)
1807 struct internalvar
*var
;
1809 var
= lookup_only_internalvar (name
);
1813 return create_internalvar (name
);
1816 /* Return current value of internal variable VAR. For variables that
1817 are not inherently typed, use a value type appropriate for GDBARCH. */
1820 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1823 struct trace_state_variable
*tsv
;
1825 /* If there is a trace state variable of the same name, assume that
1826 is what we really want to see. */
1827 tsv
= find_trace_state_variable (var
->name
);
1830 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1832 if (tsv
->value_known
)
1833 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1836 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1842 case INTERNALVAR_VOID
:
1843 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1846 case INTERNALVAR_FUNCTION
:
1847 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1850 case INTERNALVAR_INTEGER
:
1851 if (!var
->u
.integer
.type
)
1852 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1853 var
->u
.integer
.val
);
1855 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1858 case INTERNALVAR_STRING
:
1859 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1860 builtin_type (gdbarch
)->builtin_char
);
1863 case INTERNALVAR_VALUE
:
1864 val
= value_copy (var
->u
.value
);
1865 if (value_lazy (val
))
1866 value_fetch_lazy (val
);
1869 case INTERNALVAR_MAKE_VALUE
:
1870 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
1871 var
->u
.make_value
.data
);
1875 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1878 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1879 on this value go back to affect the original internal variable.
1881 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1882 no underlying modifyable state in the internal variable.
1884 Likewise, if the variable's value is a computed lvalue, we want
1885 references to it to produce another computed lvalue, where
1886 references and assignments actually operate through the
1887 computed value's functions.
1889 This means that internal variables with computed values
1890 behave a little differently from other internal variables:
1891 assignments to them don't just replace the previous value
1892 altogether. At the moment, this seems like the behavior we
1895 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1896 && val
->lval
!= lval_computed
)
1898 VALUE_LVAL (val
) = lval_internalvar
;
1899 VALUE_INTERNALVAR (val
) = var
;
1906 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1908 if (var
->kind
== INTERNALVAR_INTEGER
)
1910 *result
= var
->u
.integer
.val
;
1914 if (var
->kind
== INTERNALVAR_VALUE
)
1916 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1918 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1920 *result
= value_as_long (var
->u
.value
);
1929 get_internalvar_function (struct internalvar
*var
,
1930 struct internal_function
**result
)
1934 case INTERNALVAR_FUNCTION
:
1935 *result
= var
->u
.fn
.function
;
1944 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1945 int bitsize
, struct value
*newval
)
1951 case INTERNALVAR_VALUE
:
1952 addr
= value_contents_writeable (var
->u
.value
);
1955 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1956 value_as_long (newval
), bitpos
, bitsize
);
1958 memcpy (addr
+ offset
, value_contents (newval
),
1959 TYPE_LENGTH (value_type (newval
)));
1963 /* We can never get a component of any other kind. */
1964 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1969 set_internalvar (struct internalvar
*var
, struct value
*val
)
1971 enum internalvar_kind new_kind
;
1972 union internalvar_data new_data
= { 0 };
1974 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1975 error (_("Cannot overwrite convenience function %s"), var
->name
);
1977 /* Prepare new contents. */
1978 switch (TYPE_CODE (check_typedef (value_type (val
))))
1980 case TYPE_CODE_VOID
:
1981 new_kind
= INTERNALVAR_VOID
;
1984 case TYPE_CODE_INTERNAL_FUNCTION
:
1985 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1986 new_kind
= INTERNALVAR_FUNCTION
;
1987 get_internalvar_function (VALUE_INTERNALVAR (val
),
1988 &new_data
.fn
.function
);
1989 /* Copies created here are never canonical. */
1993 new_kind
= INTERNALVAR_VALUE
;
1994 new_data
.value
= value_copy (val
);
1995 new_data
.value
->modifiable
= 1;
1997 /* Force the value to be fetched from the target now, to avoid problems
1998 later when this internalvar is referenced and the target is gone or
2000 if (value_lazy (new_data
.value
))
2001 value_fetch_lazy (new_data
.value
);
2003 /* Release the value from the value chain to prevent it from being
2004 deleted by free_all_values. From here on this function should not
2005 call error () until new_data is installed into the var->u to avoid
2007 release_value (new_data
.value
);
2011 /* Clean up old contents. */
2012 clear_internalvar (var
);
2015 var
->kind
= new_kind
;
2017 /* End code which must not call error(). */
2021 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2023 /* Clean up old contents. */
2024 clear_internalvar (var
);
2026 var
->kind
= INTERNALVAR_INTEGER
;
2027 var
->u
.integer
.type
= NULL
;
2028 var
->u
.integer
.val
= l
;
2032 set_internalvar_string (struct internalvar
*var
, const char *string
)
2034 /* Clean up old contents. */
2035 clear_internalvar (var
);
2037 var
->kind
= INTERNALVAR_STRING
;
2038 var
->u
.string
= xstrdup (string
);
2042 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2044 /* Clean up old contents. */
2045 clear_internalvar (var
);
2047 var
->kind
= INTERNALVAR_FUNCTION
;
2048 var
->u
.fn
.function
= f
;
2049 var
->u
.fn
.canonical
= 1;
2050 /* Variables installed here are always the canonical version. */
2054 clear_internalvar (struct internalvar
*var
)
2056 /* Clean up old contents. */
2059 case INTERNALVAR_VALUE
:
2060 value_free (var
->u
.value
);
2063 case INTERNALVAR_STRING
:
2064 xfree (var
->u
.string
);
2067 case INTERNALVAR_MAKE_VALUE
:
2068 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2069 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2076 /* Reset to void kind. */
2077 var
->kind
= INTERNALVAR_VOID
;
2081 internalvar_name (struct internalvar
*var
)
2086 static struct internal_function
*
2087 create_internal_function (const char *name
,
2088 internal_function_fn handler
, void *cookie
)
2090 struct internal_function
*ifn
= XNEW (struct internal_function
);
2092 ifn
->name
= xstrdup (name
);
2093 ifn
->handler
= handler
;
2094 ifn
->cookie
= cookie
;
2099 value_internal_function_name (struct value
*val
)
2101 struct internal_function
*ifn
;
2104 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2105 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2106 gdb_assert (result
);
2112 call_internal_function (struct gdbarch
*gdbarch
,
2113 const struct language_defn
*language
,
2114 struct value
*func
, int argc
, struct value
**argv
)
2116 struct internal_function
*ifn
;
2119 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2120 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2121 gdb_assert (result
);
2123 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2126 /* The 'function' command. This does nothing -- it is just a
2127 placeholder to let "help function NAME" work. This is also used as
2128 the implementation of the sub-command that is created when
2129 registering an internal function. */
2131 function_command (char *command
, int from_tty
)
2136 /* Clean up if an internal function's command is destroyed. */
2138 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2140 xfree ((char *) self
->name
);
2144 /* Add a new internal function. NAME is the name of the function; DOC
2145 is a documentation string describing the function. HANDLER is
2146 called when the function is invoked. COOKIE is an arbitrary
2147 pointer which is passed to HANDLER and is intended for "user
2150 add_internal_function (const char *name
, const char *doc
,
2151 internal_function_fn handler
, void *cookie
)
2153 struct cmd_list_element
*cmd
;
2154 struct internal_function
*ifn
;
2155 struct internalvar
*var
= lookup_internalvar (name
);
2157 ifn
= create_internal_function (name
, handler
, cookie
);
2158 set_internalvar_function (var
, ifn
);
2160 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2162 cmd
->destroyer
= function_destroyer
;
2165 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2166 prevent cycles / duplicates. */
2169 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2170 htab_t copied_types
)
2172 if (TYPE_OBJFILE (value
->type
) == objfile
)
2173 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2175 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2176 value
->enclosing_type
= copy_type_recursive (objfile
,
2177 value
->enclosing_type
,
2181 /* Likewise for internal variable VAR. */
2184 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2185 htab_t copied_types
)
2189 case INTERNALVAR_INTEGER
:
2190 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2192 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2195 case INTERNALVAR_VALUE
:
2196 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2201 /* Update the internal variables and value history when OBJFILE is
2202 discarded; we must copy the types out of the objfile. New global types
2203 will be created for every convenience variable which currently points to
2204 this objfile's types, and the convenience variables will be adjusted to
2205 use the new global types. */
2208 preserve_values (struct objfile
*objfile
)
2210 htab_t copied_types
;
2211 struct value_history_chunk
*cur
;
2212 struct internalvar
*var
;
2215 /* Create the hash table. We allocate on the objfile's obstack, since
2216 it is soon to be deleted. */
2217 copied_types
= create_copied_types_hash (objfile
);
2219 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2220 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2222 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2224 for (var
= internalvars
; var
; var
= var
->next
)
2225 preserve_one_internalvar (var
, objfile
, copied_types
);
2227 preserve_python_values (objfile
, copied_types
);
2229 htab_delete (copied_types
);
2233 show_convenience (char *ignore
, int from_tty
)
2235 struct gdbarch
*gdbarch
= get_current_arch ();
2236 struct internalvar
*var
;
2238 struct value_print_options opts
;
2240 get_user_print_options (&opts
);
2241 for (var
= internalvars
; var
; var
= var
->next
)
2243 volatile struct gdb_exception ex
;
2249 printf_filtered (("$%s = "), var
->name
);
2251 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2255 val
= value_of_internalvar (gdbarch
, var
);
2256 value_print (val
, gdb_stdout
, &opts
);
2259 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2260 printf_filtered (("\n"));
2264 /* This text does not mention convenience functions on purpose.
2265 The user can't create them except via Python, and if Python support
2266 is installed this message will never be printed ($_streq will
2268 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2269 "Convenience variables have "
2270 "names starting with \"$\";\n"
2271 "use \"set\" as in \"set "
2272 "$foo = 5\" to define them.\n"));
2276 /* Extract a value as a C number (either long or double).
2277 Knows how to convert fixed values to double, or
2278 floating values to long.
2279 Does not deallocate the value. */
2282 value_as_long (struct value
*val
)
2284 /* This coerces arrays and functions, which is necessary (e.g.
2285 in disassemble_command). It also dereferences references, which
2286 I suspect is the most logical thing to do. */
2287 val
= coerce_array (val
);
2288 return unpack_long (value_type (val
), value_contents (val
));
2292 value_as_double (struct value
*val
)
2297 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2299 error (_("Invalid floating value found in program."));
2303 /* Extract a value as a C pointer. Does not deallocate the value.
2304 Note that val's type may not actually be a pointer; value_as_long
2305 handles all the cases. */
2307 value_as_address (struct value
*val
)
2309 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2311 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2312 whether we want this to be true eventually. */
2314 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2315 non-address (e.g. argument to "signal", "info break", etc.), or
2316 for pointers to char, in which the low bits *are* significant. */
2317 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2320 /* There are several targets (IA-64, PowerPC, and others) which
2321 don't represent pointers to functions as simply the address of
2322 the function's entry point. For example, on the IA-64, a
2323 function pointer points to a two-word descriptor, generated by
2324 the linker, which contains the function's entry point, and the
2325 value the IA-64 "global pointer" register should have --- to
2326 support position-independent code. The linker generates
2327 descriptors only for those functions whose addresses are taken.
2329 On such targets, it's difficult for GDB to convert an arbitrary
2330 function address into a function pointer; it has to either find
2331 an existing descriptor for that function, or call malloc and
2332 build its own. On some targets, it is impossible for GDB to
2333 build a descriptor at all: the descriptor must contain a jump
2334 instruction; data memory cannot be executed; and code memory
2337 Upon entry to this function, if VAL is a value of type `function'
2338 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2339 value_address (val) is the address of the function. This is what
2340 you'll get if you evaluate an expression like `main'. The call
2341 to COERCE_ARRAY below actually does all the usual unary
2342 conversions, which includes converting values of type `function'
2343 to `pointer to function'. This is the challenging conversion
2344 discussed above. Then, `unpack_long' will convert that pointer
2345 back into an address.
2347 So, suppose the user types `disassemble foo' on an architecture
2348 with a strange function pointer representation, on which GDB
2349 cannot build its own descriptors, and suppose further that `foo'
2350 has no linker-built descriptor. The address->pointer conversion
2351 will signal an error and prevent the command from running, even
2352 though the next step would have been to convert the pointer
2353 directly back into the same address.
2355 The following shortcut avoids this whole mess. If VAL is a
2356 function, just return its address directly. */
2357 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2358 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2359 return value_address (val
);
2361 val
= coerce_array (val
);
2363 /* Some architectures (e.g. Harvard), map instruction and data
2364 addresses onto a single large unified address space. For
2365 instance: An architecture may consider a large integer in the
2366 range 0x10000000 .. 0x1000ffff to already represent a data
2367 addresses (hence not need a pointer to address conversion) while
2368 a small integer would still need to be converted integer to
2369 pointer to address. Just assume such architectures handle all
2370 integer conversions in a single function. */
2374 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2375 must admonish GDB hackers to make sure its behavior matches the
2376 compiler's, whenever possible.
2378 In general, I think GDB should evaluate expressions the same way
2379 the compiler does. When the user copies an expression out of
2380 their source code and hands it to a `print' command, they should
2381 get the same value the compiler would have computed. Any
2382 deviation from this rule can cause major confusion and annoyance,
2383 and needs to be justified carefully. In other words, GDB doesn't
2384 really have the freedom to do these conversions in clever and
2387 AndrewC pointed out that users aren't complaining about how GDB
2388 casts integers to pointers; they are complaining that they can't
2389 take an address from a disassembly listing and give it to `x/i'.
2390 This is certainly important.
2392 Adding an architecture method like integer_to_address() certainly
2393 makes it possible for GDB to "get it right" in all circumstances
2394 --- the target has complete control over how things get done, so
2395 people can Do The Right Thing for their target without breaking
2396 anyone else. The standard doesn't specify how integers get
2397 converted to pointers; usually, the ABI doesn't either, but
2398 ABI-specific code is a more reasonable place to handle it. */
2400 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2401 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2402 && gdbarch_integer_to_address_p (gdbarch
))
2403 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2404 value_contents (val
));
2406 return unpack_long (value_type (val
), value_contents (val
));
2410 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2411 as a long, or as a double, assuming the raw data is described
2412 by type TYPE. Knows how to convert different sizes of values
2413 and can convert between fixed and floating point. We don't assume
2414 any alignment for the raw data. Return value is in host byte order.
2416 If you want functions and arrays to be coerced to pointers, and
2417 references to be dereferenced, call value_as_long() instead.
2419 C++: It is assumed that the front-end has taken care of
2420 all matters concerning pointers to members. A pointer
2421 to member which reaches here is considered to be equivalent
2422 to an INT (or some size). After all, it is only an offset. */
2425 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2427 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2428 enum type_code code
= TYPE_CODE (type
);
2429 int len
= TYPE_LENGTH (type
);
2430 int nosign
= TYPE_UNSIGNED (type
);
2434 case TYPE_CODE_TYPEDEF
:
2435 return unpack_long (check_typedef (type
), valaddr
);
2436 case TYPE_CODE_ENUM
:
2437 case TYPE_CODE_FLAGS
:
2438 case TYPE_CODE_BOOL
:
2440 case TYPE_CODE_CHAR
:
2441 case TYPE_CODE_RANGE
:
2442 case TYPE_CODE_MEMBERPTR
:
2444 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2446 return extract_signed_integer (valaddr
, len
, byte_order
);
2449 return extract_typed_floating (valaddr
, type
);
2451 case TYPE_CODE_DECFLOAT
:
2452 /* libdecnumber has a function to convert from decimal to integer, but
2453 it doesn't work when the decimal number has a fractional part. */
2454 return decimal_to_doublest (valaddr
, len
, byte_order
);
2458 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2459 whether we want this to be true eventually. */
2460 return extract_typed_address (valaddr
, type
);
2463 error (_("Value can't be converted to integer."));
2465 return 0; /* Placate lint. */
2468 /* Return a double value from the specified type and address.
2469 INVP points to an int which is set to 0 for valid value,
2470 1 for invalid value (bad float format). In either case,
2471 the returned double is OK to use. Argument is in target
2472 format, result is in host format. */
2475 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2477 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2478 enum type_code code
;
2482 *invp
= 0; /* Assume valid. */
2483 CHECK_TYPEDEF (type
);
2484 code
= TYPE_CODE (type
);
2485 len
= TYPE_LENGTH (type
);
2486 nosign
= TYPE_UNSIGNED (type
);
2487 if (code
== TYPE_CODE_FLT
)
2489 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2490 floating-point value was valid (using the macro
2491 INVALID_FLOAT). That test/macro have been removed.
2493 It turns out that only the VAX defined this macro and then
2494 only in a non-portable way. Fixing the portability problem
2495 wouldn't help since the VAX floating-point code is also badly
2496 bit-rotten. The target needs to add definitions for the
2497 methods gdbarch_float_format and gdbarch_double_format - these
2498 exactly describe the target floating-point format. The
2499 problem here is that the corresponding floatformat_vax_f and
2500 floatformat_vax_d values these methods should be set to are
2501 also not defined either. Oops!
2503 Hopefully someone will add both the missing floatformat
2504 definitions and the new cases for floatformat_is_valid (). */
2506 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2512 return extract_typed_floating (valaddr
, type
);
2514 else if (code
== TYPE_CODE_DECFLOAT
)
2515 return decimal_to_doublest (valaddr
, len
, byte_order
);
2518 /* Unsigned -- be sure we compensate for signed LONGEST. */
2519 return (ULONGEST
) unpack_long (type
, valaddr
);
2523 /* Signed -- we are OK with unpack_long. */
2524 return unpack_long (type
, valaddr
);
2528 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2529 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2530 We don't assume any alignment for the raw data. Return value is in
2533 If you want functions and arrays to be coerced to pointers, and
2534 references to be dereferenced, call value_as_address() instead.
2536 C++: It is assumed that the front-end has taken care of
2537 all matters concerning pointers to members. A pointer
2538 to member which reaches here is considered to be equivalent
2539 to an INT (or some size). After all, it is only an offset. */
2542 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2544 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2545 whether we want this to be true eventually. */
2546 return unpack_long (type
, valaddr
);
2550 /* Get the value of the FIELDNO'th field (which must be static) of
2551 TYPE. Return NULL if the field doesn't exist or has been
2555 value_static_field (struct type
*type
, int fieldno
)
2557 struct value
*retval
;
2559 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2561 case FIELD_LOC_KIND_PHYSADDR
:
2562 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2563 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2565 case FIELD_LOC_KIND_PHYSNAME
:
2567 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2568 /* TYPE_FIELD_NAME (type, fieldno); */
2569 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2573 /* With some compilers, e.g. HP aCC, static data members are
2574 reported as non-debuggable symbols. */
2575 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2582 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2583 SYMBOL_VALUE_ADDRESS (msym
));
2587 retval
= value_of_variable (sym
, NULL
);
2591 gdb_assert_not_reached ("unexpected field location kind");
2597 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2598 You have to be careful here, since the size of the data area for the value
2599 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2600 than the old enclosing type, you have to allocate more space for the
2604 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2606 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2608 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2610 val
->enclosing_type
= new_encl_type
;
2613 /* Given a value ARG1 (offset by OFFSET bytes)
2614 of a struct or union type ARG_TYPE,
2615 extract and return the value of one of its (non-static) fields.
2616 FIELDNO says which field. */
2619 value_primitive_field (struct value
*arg1
, int offset
,
2620 int fieldno
, struct type
*arg_type
)
2625 CHECK_TYPEDEF (arg_type
);
2626 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2628 /* Call check_typedef on our type to make sure that, if TYPE
2629 is a TYPE_CODE_TYPEDEF, its length is set to the length
2630 of the target type instead of zero. However, we do not
2631 replace the typedef type by the target type, because we want
2632 to keep the typedef in order to be able to print the type
2633 description correctly. */
2634 check_typedef (type
);
2636 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2638 /* Handle packed fields.
2640 Create a new value for the bitfield, with bitpos and bitsize
2641 set. If possible, arrange offset and bitpos so that we can
2642 do a single aligned read of the size of the containing type.
2643 Otherwise, adjust offset to the byte containing the first
2644 bit. Assume that the address, offset, and embedded offset
2645 are sufficiently aligned. */
2647 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2648 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2650 if (arg1
->optimized_out
)
2651 v
= allocate_optimized_out_value (type
);
2654 v
= allocate_value_lazy (type
);
2655 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2656 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2657 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2658 v
->bitpos
= bitpos
% container_bitsize
;
2660 v
->bitpos
= bitpos
% 8;
2661 v
->offset
= (value_embedded_offset (arg1
)
2663 + (bitpos
- v
->bitpos
) / 8);
2664 set_value_parent (v
, arg1
);
2665 if (!value_lazy (arg1
))
2666 value_fetch_lazy (v
);
2669 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2671 /* This field is actually a base subobject, so preserve the
2672 entire object's contents for later references to virtual
2676 /* Lazy register values with offsets are not supported. */
2677 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2678 value_fetch_lazy (arg1
);
2680 /* The optimized_out flag is only set correctly once a lazy value is
2681 loaded, having just loaded some lazy values we should check the
2682 optimized out case now. */
2683 if (arg1
->optimized_out
)
2684 v
= allocate_optimized_out_value (type
);
2687 /* We special case virtual inheritance here because this
2688 requires access to the contents, which we would rather avoid
2689 for references to ordinary fields of unavailable values. */
2690 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2691 boffset
= baseclass_offset (arg_type
, fieldno
,
2692 value_contents (arg1
),
2693 value_embedded_offset (arg1
),
2694 value_address (arg1
),
2697 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2699 if (value_lazy (arg1
))
2700 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2703 v
= allocate_value (value_enclosing_type (arg1
));
2704 value_contents_copy_raw (v
, 0, arg1
, 0,
2705 TYPE_LENGTH (value_enclosing_type (arg1
)));
2708 v
->offset
= value_offset (arg1
);
2709 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2714 /* Plain old data member */
2715 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2717 /* Lazy register values with offsets are not supported. */
2718 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2719 value_fetch_lazy (arg1
);
2721 /* The optimized_out flag is only set correctly once a lazy value is
2722 loaded, having just loaded some lazy values we should check for
2723 the optimized out case now. */
2724 if (arg1
->optimized_out
)
2725 v
= allocate_optimized_out_value (type
);
2726 else if (value_lazy (arg1
))
2727 v
= allocate_value_lazy (type
);
2730 v
= allocate_value (type
);
2731 value_contents_copy_raw (v
, value_embedded_offset (v
),
2732 arg1
, value_embedded_offset (arg1
) + offset
,
2733 TYPE_LENGTH (type
));
2735 v
->offset
= (value_offset (arg1
) + offset
2736 + value_embedded_offset (arg1
));
2738 set_value_component_location (v
, arg1
);
2739 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2740 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2744 /* Given a value ARG1 of a struct or union type,
2745 extract and return the value of one of its (non-static) fields.
2746 FIELDNO says which field. */
2749 value_field (struct value
*arg1
, int fieldno
)
2751 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2754 /* Return a non-virtual function as a value.
2755 F is the list of member functions which contains the desired method.
2756 J is an index into F which provides the desired method.
2758 We only use the symbol for its address, so be happy with either a
2759 full symbol or a minimal symbol. */
2762 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2763 int j
, struct type
*type
,
2767 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2768 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2770 struct minimal_symbol
*msym
;
2772 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2779 gdb_assert (sym
== NULL
);
2780 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2785 v
= allocate_value (ftype
);
2788 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2792 /* The minimal symbol might point to a function descriptor;
2793 resolve it to the actual code address instead. */
2794 struct objfile
*objfile
= msymbol_objfile (msym
);
2795 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2797 set_value_address (v
,
2798 gdbarch_convert_from_func_ptr_addr
2799 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2804 if (type
!= value_type (*arg1p
))
2805 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2806 value_addr (*arg1p
)));
2808 /* Move the `this' pointer according to the offset.
2809 VALUE_OFFSET (*arg1p) += offset; */
2817 /* Helper function for both unpack_value_bits_as_long and
2818 unpack_bits_as_long. See those functions for more details on the
2819 interface; the only difference is that this function accepts either
2820 a NULL or a non-NULL ORIGINAL_VALUE. */
2823 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2824 int embedded_offset
, int bitpos
, int bitsize
,
2825 const struct value
*original_value
,
2828 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2835 /* Read the minimum number of bytes required; there may not be
2836 enough bytes to read an entire ULONGEST. */
2837 CHECK_TYPEDEF (field_type
);
2839 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2841 bytes_read
= TYPE_LENGTH (field_type
);
2843 read_offset
= bitpos
/ 8;
2845 if (original_value
!= NULL
2846 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2850 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2851 bytes_read
, byte_order
);
2853 /* Extract bits. See comment above. */
2855 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2856 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2858 lsbcount
= (bitpos
% 8);
2861 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2862 If the field is signed, and is negative, then sign extend. */
2864 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2866 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2868 if (!TYPE_UNSIGNED (field_type
))
2870 if (val
& (valmask
^ (valmask
>> 1)))
2881 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2882 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2883 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2884 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2887 Returns false if the value contents are unavailable, otherwise
2888 returns true, indicating a valid value has been stored in *RESULT.
2890 Extracting bits depends on endianness of the machine. Compute the
2891 number of least significant bits to discard. For big endian machines,
2892 we compute the total number of bits in the anonymous object, subtract
2893 off the bit count from the MSB of the object to the MSB of the
2894 bitfield, then the size of the bitfield, which leaves the LSB discard
2895 count. For little endian machines, the discard count is simply the
2896 number of bits from the LSB of the anonymous object to the LSB of the
2899 If the field is signed, we also do sign extension. */
2902 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2903 int embedded_offset
, int bitpos
, int bitsize
,
2904 const struct value
*original_value
,
2907 gdb_assert (original_value
!= NULL
);
2909 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2910 bitpos
, bitsize
, original_value
, result
);
2914 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2915 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2916 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2920 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2921 int embedded_offset
, int fieldno
,
2922 const struct value
*val
, LONGEST
*result
)
2924 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2925 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2926 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2928 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2929 bitpos
, bitsize
, val
,
2933 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2934 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2935 ORIGINAL_VALUE, which must not be NULL. See
2936 unpack_value_bits_as_long for more details. */
2939 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2940 int embedded_offset
, int fieldno
,
2941 const struct value
*val
, LONGEST
*result
)
2943 gdb_assert (val
!= NULL
);
2945 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2946 fieldno
, val
, result
);
2949 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2950 object at VALADDR. See unpack_value_bits_as_long for more details.
2951 This function differs from unpack_value_field_as_long in that it
2952 operates without a struct value object. */
2955 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2959 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2963 /* Return a new value with type TYPE, which is FIELDNO field of the
2964 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2965 of VAL. If the VAL's contents required to extract the bitfield
2966 from are unavailable, the new value is correspondingly marked as
2970 value_field_bitfield (struct type
*type
, int fieldno
,
2971 const gdb_byte
*valaddr
,
2972 int embedded_offset
, const struct value
*val
)
2976 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2979 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2980 struct value
*retval
= allocate_value (field_type
);
2981 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2986 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2990 /* Modify the value of a bitfield. ADDR points to a block of memory in
2991 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2992 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2993 indicate which bits (in target bit order) comprise the bitfield.
2994 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2995 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2998 modify_field (struct type
*type
, gdb_byte
*addr
,
2999 LONGEST fieldval
, int bitpos
, int bitsize
)
3001 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3003 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3006 /* Normalize BITPOS. */
3010 /* If a negative fieldval fits in the field in question, chop
3011 off the sign extension bits. */
3012 if ((~fieldval
& ~(mask
>> 1)) == 0)
3015 /* Warn if value is too big to fit in the field in question. */
3016 if (0 != (fieldval
& ~mask
))
3018 /* FIXME: would like to include fieldval in the message, but
3019 we don't have a sprintf_longest. */
3020 warning (_("Value does not fit in %d bits."), bitsize
);
3022 /* Truncate it, otherwise adjoining fields may be corrupted. */
3026 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3027 false valgrind reports. */
3029 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3030 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3032 /* Shifting for bit field depends on endianness of the target machine. */
3033 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3034 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3036 oword
&= ~(mask
<< bitpos
);
3037 oword
|= fieldval
<< bitpos
;
3039 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3042 /* Pack NUM into BUF using a target format of TYPE. */
3045 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3047 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3050 type
= check_typedef (type
);
3051 len
= TYPE_LENGTH (type
);
3053 switch (TYPE_CODE (type
))
3056 case TYPE_CODE_CHAR
:
3057 case TYPE_CODE_ENUM
:
3058 case TYPE_CODE_FLAGS
:
3059 case TYPE_CODE_BOOL
:
3060 case TYPE_CODE_RANGE
:
3061 case TYPE_CODE_MEMBERPTR
:
3062 store_signed_integer (buf
, len
, byte_order
, num
);
3067 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3071 error (_("Unexpected type (%d) encountered for integer constant."),
3077 /* Pack NUM into BUF using a target format of TYPE. */
3080 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3083 enum bfd_endian byte_order
;
3085 type
= check_typedef (type
);
3086 len
= TYPE_LENGTH (type
);
3087 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3089 switch (TYPE_CODE (type
))
3092 case TYPE_CODE_CHAR
:
3093 case TYPE_CODE_ENUM
:
3094 case TYPE_CODE_FLAGS
:
3095 case TYPE_CODE_BOOL
:
3096 case TYPE_CODE_RANGE
:
3097 case TYPE_CODE_MEMBERPTR
:
3098 store_unsigned_integer (buf
, len
, byte_order
, num
);
3103 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3107 error (_("Unexpected type (%d) encountered "
3108 "for unsigned integer constant."),
3114 /* Convert C numbers into newly allocated values. */
3117 value_from_longest (struct type
*type
, LONGEST num
)
3119 struct value
*val
= allocate_value (type
);
3121 pack_long (value_contents_raw (val
), type
, num
);
3126 /* Convert C unsigned numbers into newly allocated values. */
3129 value_from_ulongest (struct type
*type
, ULONGEST num
)
3131 struct value
*val
= allocate_value (type
);
3133 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3139 /* Create a value representing a pointer of type TYPE to the address
3142 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3144 struct value
*val
= allocate_value (type
);
3146 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3151 /* Create a value of type TYPE whose contents come from VALADDR, if it
3152 is non-null, and whose memory address (in the inferior) is
3156 value_from_contents_and_address (struct type
*type
,
3157 const gdb_byte
*valaddr
,
3162 if (valaddr
== NULL
)
3163 v
= allocate_value_lazy (type
);
3166 v
= allocate_value (type
);
3167 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3169 set_value_address (v
, address
);
3170 VALUE_LVAL (v
) = lval_memory
;
3174 /* Create a value of type TYPE holding the contents CONTENTS.
3175 The new value is `not_lval'. */
3178 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3180 struct value
*result
;
3182 result
= allocate_value (type
);
3183 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3188 value_from_double (struct type
*type
, DOUBLEST num
)
3190 struct value
*val
= allocate_value (type
);
3191 struct type
*base_type
= check_typedef (type
);
3192 enum type_code code
= TYPE_CODE (base_type
);
3194 if (code
== TYPE_CODE_FLT
)
3196 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3199 error (_("Unexpected type encountered for floating constant."));
3205 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3207 struct value
*val
= allocate_value (type
);
3209 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3213 /* Extract a value from the history file. Input will be of the form
3214 $digits or $$digits. See block comment above 'write_dollar_variable'
3218 value_from_history_ref (char *h
, char **endp
)
3230 /* Find length of numeral string. */
3231 for (; isdigit (h
[len
]); len
++)
3234 /* Make sure numeral string is not part of an identifier. */
3235 if (h
[len
] == '_' || isalpha (h
[len
]))
3238 /* Now collect the index value. */
3243 /* For some bizarre reason, "$$" is equivalent to "$$1",
3244 rather than to "$$0" as it ought to be! */
3249 index
= -strtol (&h
[2], endp
, 10);
3255 /* "$" is equivalent to "$0". */
3260 index
= strtol (&h
[1], endp
, 10);
3263 return access_value_history (index
);
3267 coerce_ref_if_computed (const struct value
*arg
)
3269 const struct lval_funcs
*funcs
;
3271 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3274 if (value_lval_const (arg
) != lval_computed
)
3277 funcs
= value_computed_funcs (arg
);
3278 if (funcs
->coerce_ref
== NULL
)
3281 return funcs
->coerce_ref (arg
);
3284 /* Look at value.h for description. */
3287 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3288 struct type
*original_type
,
3289 struct value
*original_value
)
3291 /* Re-adjust type. */
3292 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3294 /* Add embedding info. */
3295 set_value_enclosing_type (value
, enc_type
);
3296 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3298 /* We may be pointing to an object of some derived type. */
3299 return value_full_object (value
, NULL
, 0, 0, 0);
3303 coerce_ref (struct value
*arg
)
3305 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3306 struct value
*retval
;
3307 struct type
*enc_type
;
3309 retval
= coerce_ref_if_computed (arg
);
3313 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3316 enc_type
= check_typedef (value_enclosing_type (arg
));
3317 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3319 retval
= value_at_lazy (enc_type
,
3320 unpack_pointer (value_type (arg
),
3321 value_contents (arg
)));
3322 return readjust_indirect_value_type (retval
, enc_type
,
3323 value_type_arg_tmp
, arg
);
3327 coerce_array (struct value
*arg
)
3331 arg
= coerce_ref (arg
);
3332 type
= check_typedef (value_type (arg
));
3334 switch (TYPE_CODE (type
))
3336 case TYPE_CODE_ARRAY
:
3337 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3338 arg
= value_coerce_array (arg
);
3340 case TYPE_CODE_FUNC
:
3341 arg
= value_coerce_function (arg
);
3348 /* Return the return value convention that will be used for the
3351 enum return_value_convention
3352 struct_return_convention (struct gdbarch
*gdbarch
,
3353 struct value
*function
, struct type
*value_type
)
3355 enum type_code code
= TYPE_CODE (value_type
);
3357 if (code
== TYPE_CODE_ERROR
)
3358 error (_("Function return type unknown."));
3360 /* Probe the architecture for the return-value convention. */
3361 return gdbarch_return_value (gdbarch
, function
, value_type
,
3365 /* Return true if the function returning the specified type is using
3366 the convention of returning structures in memory (passing in the
3367 address as a hidden first parameter). */
3370 using_struct_return (struct gdbarch
*gdbarch
,
3371 struct value
*function
, struct type
*value_type
)
3373 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3374 /* A void return value is never in memory. See also corresponding
3375 code in "print_return_value". */
3378 return (struct_return_convention (gdbarch
, function
, value_type
)
3379 != RETURN_VALUE_REGISTER_CONVENTION
);
3382 /* Set the initialized field in a value struct. */
3385 set_value_initialized (struct value
*val
, int status
)
3387 val
->initialized
= status
;
3390 /* Return the initialized field in a value struct. */
3393 value_initialized (struct value
*val
)
3395 return val
->initialized
;
3398 /* Called only from the value_contents and value_contents_all()
3399 macros, if the current data for a variable needs to be loaded into
3400 value_contents(VAL). Fetches the data from the user's process, and
3401 clears the lazy flag to indicate that the data in the buffer is
3404 If the value is zero-length, we avoid calling read_memory, which
3405 would abort. We mark the value as fetched anyway -- all 0 bytes of
3408 This function returns a value because it is used in the
3409 value_contents macro as part of an expression, where a void would
3410 not work. The value is ignored. */
3413 value_fetch_lazy (struct value
*val
)
3415 gdb_assert (value_lazy (val
));
3416 allocate_value_contents (val
);
3417 if (value_bitsize (val
))
3419 /* To read a lazy bitfield, read the entire enclosing value. This
3420 prevents reading the same block of (possibly volatile) memory once
3421 per bitfield. It would be even better to read only the containing
3422 word, but we have no way to record that just specific bits of a
3423 value have been fetched. */
3424 struct type
*type
= check_typedef (value_type (val
));
3425 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3426 struct value
*parent
= value_parent (val
);
3427 LONGEST offset
= value_offset (val
);
3430 if (!value_bits_valid (val
,
3431 TARGET_CHAR_BIT
* offset
+ value_bitpos (val
),
3432 value_bitsize (val
)))
3433 error (_("value has been optimized out"));
3435 if (!unpack_value_bits_as_long (value_type (val
),
3436 value_contents_for_printing (parent
),
3439 value_bitsize (val
), parent
, &num
))
3440 mark_value_bytes_unavailable (val
,
3441 value_embedded_offset (val
),
3442 TYPE_LENGTH (type
));
3444 store_signed_integer (value_contents_raw (val
), TYPE_LENGTH (type
),
3447 else if (VALUE_LVAL (val
) == lval_memory
)
3449 CORE_ADDR addr
= value_address (val
);
3450 struct type
*type
= check_typedef (value_enclosing_type (val
));
3452 if (TYPE_LENGTH (type
))
3453 read_value_memory (val
, 0, value_stack (val
),
3454 addr
, value_contents_all_raw (val
),
3455 TYPE_LENGTH (type
));
3457 else if (VALUE_LVAL (val
) == lval_register
)
3459 struct frame_info
*frame
;
3461 struct type
*type
= check_typedef (value_type (val
));
3462 struct value
*new_val
= val
, *mark
= value_mark ();
3464 /* Offsets are not supported here; lazy register values must
3465 refer to the entire register. */
3466 gdb_assert (value_offset (val
) == 0);
3468 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3470 frame
= frame_find_by_id (VALUE_FRAME_ID (new_val
));
3471 regnum
= VALUE_REGNUM (new_val
);
3473 gdb_assert (frame
!= NULL
);
3475 /* Convertible register routines are used for multi-register
3476 values and for interpretation in different types
3477 (e.g. float or int from a double register). Lazy
3478 register values should have the register's natural type,
3479 so they do not apply. */
3480 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3483 new_val
= get_frame_register_value (frame
, regnum
);
3486 /* If it's still lazy (for instance, a saved register on the
3487 stack), fetch it. */
3488 if (value_lazy (new_val
))
3489 value_fetch_lazy (new_val
);
3491 /* If the register was not saved, mark it optimized out. */
3492 if (value_optimized_out (new_val
))
3493 set_value_optimized_out (val
, 1);
3496 set_value_lazy (val
, 0);
3497 value_contents_copy (val
, value_embedded_offset (val
),
3498 new_val
, value_embedded_offset (new_val
),
3499 TYPE_LENGTH (type
));
3504 struct gdbarch
*gdbarch
;
3505 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3506 regnum
= VALUE_REGNUM (val
);
3507 gdbarch
= get_frame_arch (frame
);
3509 fprintf_unfiltered (gdb_stdlog
,
3510 "{ value_fetch_lazy "
3511 "(frame=%d,regnum=%d(%s),...) ",
3512 frame_relative_level (frame
), regnum
,
3513 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3515 fprintf_unfiltered (gdb_stdlog
, "->");
3516 if (value_optimized_out (new_val
))
3517 fprintf_unfiltered (gdb_stdlog
, " optimized out");
3521 const gdb_byte
*buf
= value_contents (new_val
);
3523 if (VALUE_LVAL (new_val
) == lval_register
)
3524 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3525 VALUE_REGNUM (new_val
));
3526 else if (VALUE_LVAL (new_val
) == lval_memory
)
3527 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3529 value_address (new_val
)));
3531 fprintf_unfiltered (gdb_stdlog
, " computed");
3533 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3534 fprintf_unfiltered (gdb_stdlog
, "[");
3535 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3536 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3537 fprintf_unfiltered (gdb_stdlog
, "]");
3540 fprintf_unfiltered (gdb_stdlog
, " }\n");
3543 /* Dispose of the intermediate values. This prevents
3544 watchpoints from trying to watch the saved frame pointer. */
3545 value_free_to_mark (mark
);
3547 else if (VALUE_LVAL (val
) == lval_computed
3548 && value_computed_funcs (val
)->read
!= NULL
)
3549 value_computed_funcs (val
)->read (val
);
3550 /* Don't call value_optimized_out on val, doing so would result in a
3551 recursive call back to value_fetch_lazy, instead check the
3552 optimized_out flag directly. */
3553 else if (val
->optimized_out
)
3554 /* Keep it optimized out. */;
3556 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3558 set_value_lazy (val
, 0);
3563 _initialize_values (void)
3565 add_cmd ("convenience", no_class
, show_convenience
, _("\
3566 Debugger convenience (\"$foo\") variables and functions.\n\
3567 Convenience variables are created when you assign them values;\n\
3568 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3570 A few convenience variables are given values automatically:\n\
3571 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3572 \"$__\" holds the contents of the last address examined with \"x\"."
3575 Convenience functions are defined via the Python API."
3578 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3580 add_cmd ("values", no_set_class
, show_values
, _("\
3581 Elements of value history around item number IDX (or last ten)."),
3584 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3585 Initialize a convenience variable if necessary.\n\
3586 init-if-undefined VARIABLE = EXPRESSION\n\
3587 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3588 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3589 VARIABLE is already initialized."));
3591 add_prefix_cmd ("function", no_class
, function_command
, _("\
3592 Placeholder command for showing help on convenience functions."),
3593 &functionlist
, "function ", 0, &cmdlist
);