1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5 2009, 2010, 2011 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "arch-utils.h"
24 #include "gdb_string.h"
35 #include "gdb_assert.h"
41 #include "cli/cli-decode.h"
42 #include "exceptions.h"
43 #include "python/python.h"
45 #include "tracepoint.h"
47 /* Prototypes for exported functions. */
49 void _initialize_values (void);
51 /* Definition of a user function. */
52 struct internal_function
54 /* The name of the function. It is a bit odd to have this in the
55 function itself -- the user might use a differently-named
56 convenience variable to hold the function. */
60 internal_function_fn handler
;
62 /* User data for the handler. */
66 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
70 /* Lowest offset in the range. */
73 /* Length of the range. */
77 typedef struct range range_s
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (int offset1
, int len1
,
86 int offset2
, int len2
)
90 l
= max (offset1
, offset2
);
91 h
= min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if the first argument is strictly less than the
96 second, useful for VEC_lower_bound. We keep ranges sorted by
97 offset and coalesce overlapping and contiguous ranges, so this just
98 compares the starting offset. */
101 range_lessthan (const range_s
*r1
, const range_s
*r2
)
103 return r1
->offset
< r2
->offset
;
106 /* Returns true if RANGES contains any range that overlaps [OFFSET,
110 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
115 what
.offset
= offset
;
116 what
.length
= length
;
118 /* We keep ranges sorted by offset and coalesce overlapping and
119 contiguous ranges, so to check if a range list contains a given
120 range, we can do a binary search for the position the given range
121 would be inserted if we only considered the starting OFFSET of
122 ranges. We call that position I. Since we also have LENGTH to
123 care for (this is a range afterall), we need to check if the
124 _previous_ range overlaps the I range. E.g.,
128 |---| |---| |------| ... |--|
133 In the case above, the binary search would return `I=1', meaning,
134 this OFFSET should be inserted at position 1, and the current
135 position 1 should be pushed further (and before 2). But, `0'
138 Then we need to check if the I range overlaps the I range itself.
143 |---| |---| |-------| ... |--|
149 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
153 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
155 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
159 if (i
< VEC_length (range_s
, ranges
))
161 struct range
*r
= VEC_index (range_s
, ranges
, i
);
163 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
170 static struct cmd_list_element
*functionlist
;
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 /* This routine is used by printing routines, where we should
548 already have read the value. Note that we only know whether a
549 value chunk is available if we've tried to read it. */
550 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
558 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
560 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
563 /* The usual case is for both values to be completely available. */
564 if (idx1
== -1 && idx2
== -1)
565 return (memcmp (val1
->contents
+ offset1
,
566 val2
->contents
+ offset2
,
568 /* The contents only match equal if the available set matches as
570 else if (idx1
== -1 || idx2
== -1)
573 gdb_assert (idx1
!= -1 && idx2
!= -1);
575 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
576 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
578 /* Get the unavailable windows intersected by the incoming
579 ranges. The first and last ranges that overlap the argument
580 range may be wider than said incoming arguments ranges. */
581 l1
= max (offset1
, r1
->offset
);
582 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
584 l2
= max (offset2
, r2
->offset
);
585 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
587 /* Make them relative to the respective start offsets, so we can
588 compare them for equality. */
595 /* Different availability, no match. */
596 if (l1
!= l2
|| h1
!= h2
)
599 /* Compare the _available_ contents. */
600 if (memcmp (val1
->contents
+ offset1
,
601 val2
->contents
+ offset2
,
613 /* Prototypes for local functions. */
615 static void show_values (char *, int);
617 static void show_convenience (char *, int);
620 /* The value-history records all the values printed
621 by print commands during this session. Each chunk
622 records 60 consecutive values. The first chunk on
623 the chain records the most recent values.
624 The total number of values is in value_history_count. */
626 #define VALUE_HISTORY_CHUNK 60
628 struct value_history_chunk
630 struct value_history_chunk
*next
;
631 struct value
*values
[VALUE_HISTORY_CHUNK
];
634 /* Chain of chunks now in use. */
636 static struct value_history_chunk
*value_history_chain
;
638 static int value_history_count
; /* Abs number of last entry stored. */
641 /* List of all value objects currently allocated
642 (except for those released by calls to release_value)
643 This is so they can be freed after each command. */
645 static struct value
*all_values
;
647 /* Allocate a lazy value for type TYPE. Its actual content is
648 "lazily" allocated too: the content field of the return value is
649 NULL; it will be allocated when it is fetched from the target. */
652 allocate_value_lazy (struct type
*type
)
656 /* Call check_typedef on our type to make sure that, if TYPE
657 is a TYPE_CODE_TYPEDEF, its length is set to the length
658 of the target type instead of zero. However, we do not
659 replace the typedef type by the target type, because we want
660 to keep the typedef in order to be able to set the VAL's type
661 description correctly. */
662 check_typedef (type
);
664 val
= (struct value
*) xzalloc (sizeof (struct value
));
665 val
->contents
= NULL
;
666 val
->next
= all_values
;
669 val
->enclosing_type
= type
;
670 VALUE_LVAL (val
) = not_lval
;
671 val
->location
.address
= 0;
672 VALUE_FRAME_ID (val
) = null_frame_id
;
676 VALUE_REGNUM (val
) = -1;
678 val
->optimized_out
= 0;
679 val
->embedded_offset
= 0;
680 val
->pointed_to_offset
= 0;
682 val
->initialized
= 1; /* Default to initialized. */
684 /* Values start out on the all_values chain. */
685 val
->reference_count
= 1;
690 /* Allocate the contents of VAL if it has not been allocated yet. */
693 allocate_value_contents (struct value
*val
)
696 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
699 /* Allocate a value and its contents for type TYPE. */
702 allocate_value (struct type
*type
)
704 struct value
*val
= allocate_value_lazy (type
);
706 allocate_value_contents (val
);
711 /* Allocate a value that has the correct length
712 for COUNT repetitions of type TYPE. */
715 allocate_repeat_value (struct type
*type
, int count
)
717 int low_bound
= current_language
->string_lower_bound
; /* ??? */
718 /* FIXME-type-allocation: need a way to free this type when we are
720 struct type
*array_type
721 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
723 return allocate_value (array_type
);
727 allocate_computed_value (struct type
*type
,
728 const struct lval_funcs
*funcs
,
731 struct value
*v
= allocate_value_lazy (type
);
733 VALUE_LVAL (v
) = lval_computed
;
734 v
->location
.computed
.funcs
= funcs
;
735 v
->location
.computed
.closure
= closure
;
740 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
743 allocate_optimized_out_value (struct type
*type
)
745 struct value
*retval
= allocate_value_lazy (type
);
747 set_value_optimized_out (retval
, 1);
752 /* Accessor methods. */
755 value_next (struct value
*value
)
761 value_type (const struct value
*value
)
766 deprecated_set_value_type (struct value
*value
, struct type
*type
)
772 value_offset (const struct value
*value
)
774 return value
->offset
;
777 set_value_offset (struct value
*value
, int offset
)
779 value
->offset
= offset
;
783 value_bitpos (const struct value
*value
)
785 return value
->bitpos
;
788 set_value_bitpos (struct value
*value
, int bit
)
794 value_bitsize (const struct value
*value
)
796 return value
->bitsize
;
799 set_value_bitsize (struct value
*value
, int bit
)
801 value
->bitsize
= bit
;
805 value_parent (struct value
*value
)
807 return value
->parent
;
811 value_contents_raw (struct value
*value
)
813 allocate_value_contents (value
);
814 return value
->contents
+ value
->embedded_offset
;
818 value_contents_all_raw (struct value
*value
)
820 allocate_value_contents (value
);
821 return value
->contents
;
825 value_enclosing_type (struct value
*value
)
827 return value
->enclosing_type
;
831 require_not_optimized_out (const struct value
*value
)
833 if (value
->optimized_out
)
834 error (_("value has been optimized out"));
838 require_available (const struct value
*value
)
840 if (!VEC_empty (range_s
, value
->unavailable
))
841 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
845 value_contents_for_printing (struct value
*value
)
848 value_fetch_lazy (value
);
849 return value
->contents
;
853 value_contents_for_printing_const (const struct value
*value
)
855 gdb_assert (!value
->lazy
);
856 return value
->contents
;
860 value_contents_all (struct value
*value
)
862 const gdb_byte
*result
= value_contents_for_printing (value
);
863 require_not_optimized_out (value
);
864 require_available (value
);
868 /* Copy LENGTH bytes of SRC value's (all) contents
869 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
870 contents, starting at DST_OFFSET. If unavailable contents are
871 being copied from SRC, the corresponding DST contents are marked
872 unavailable accordingly. Neither DST nor SRC may be lazy
875 It is assumed the contents of DST in the [DST_OFFSET,
876 DST_OFFSET+LENGTH) range are wholly available. */
879 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
880 struct value
*src
, int src_offset
, int length
)
885 /* A lazy DST would make that this copy operation useless, since as
886 soon as DST's contents were un-lazied (by a later value_contents
887 call, say), the contents would be overwritten. A lazy SRC would
888 mean we'd be copying garbage. */
889 gdb_assert (!dst
->lazy
&& !src
->lazy
);
891 /* The overwritten DST range gets unavailability ORed in, not
892 replaced. Make sure to remember to implement replacing if it
893 turns out actually necessary. */
894 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
897 memcpy (value_contents_all_raw (dst
) + dst_offset
,
898 value_contents_all_raw (src
) + src_offset
,
901 /* Copy the meta-data, adjusted. */
902 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
906 l
= max (r
->offset
, src_offset
);
907 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
910 mark_value_bytes_unavailable (dst
,
911 dst_offset
+ (l
- src_offset
),
916 /* Copy LENGTH bytes of SRC value's (all) contents
917 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
918 (all) contents, starting at DST_OFFSET. If unavailable contents
919 are being copied from SRC, the corresponding DST contents are
920 marked unavailable accordingly. DST must not be lazy. If SRC is
921 lazy, it will be fetched now. If SRC is not valid (is optimized
922 out), an error is thrown.
924 It is assumed the contents of DST in the [DST_OFFSET,
925 DST_OFFSET+LENGTH) range are wholly available. */
928 value_contents_copy (struct value
*dst
, int dst_offset
,
929 struct value
*src
, int src_offset
, int length
)
931 require_not_optimized_out (src
);
934 value_fetch_lazy (src
);
936 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
940 value_lazy (struct value
*value
)
946 set_value_lazy (struct value
*value
, int val
)
952 value_stack (struct value
*value
)
958 set_value_stack (struct value
*value
, int val
)
964 value_contents (struct value
*value
)
966 const gdb_byte
*result
= value_contents_writeable (value
);
967 require_not_optimized_out (value
);
968 require_available (value
);
973 value_contents_writeable (struct value
*value
)
976 value_fetch_lazy (value
);
977 return value_contents_raw (value
);
980 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
981 this function is different from value_equal; in C the operator ==
982 can return 0 even if the two values being compared are equal. */
985 value_contents_equal (struct value
*val1
, struct value
*val2
)
991 type1
= check_typedef (value_type (val1
));
992 type2
= check_typedef (value_type (val2
));
993 len
= TYPE_LENGTH (type1
);
994 if (len
!= TYPE_LENGTH (type2
))
997 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
1001 value_optimized_out (struct value
*value
)
1003 return value
->optimized_out
;
1007 set_value_optimized_out (struct value
*value
, int val
)
1009 value
->optimized_out
= val
;
1013 value_entirely_optimized_out (const struct value
*value
)
1015 if (!value
->optimized_out
)
1017 if (value
->lval
!= lval_computed
1018 || !value
->location
.computed
.funcs
->check_any_valid
)
1020 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1024 value_bits_valid (const struct value
*value
, int offset
, int length
)
1026 if (!value
->optimized_out
)
1028 if (value
->lval
!= lval_computed
1029 || !value
->location
.computed
.funcs
->check_validity
)
1031 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1036 value_bits_synthetic_pointer (const struct value
*value
,
1037 int offset
, int length
)
1039 if (value
->lval
!= lval_computed
1040 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1042 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1048 value_embedded_offset (struct value
*value
)
1050 return value
->embedded_offset
;
1054 set_value_embedded_offset (struct value
*value
, int val
)
1056 value
->embedded_offset
= val
;
1060 value_pointed_to_offset (struct value
*value
)
1062 return value
->pointed_to_offset
;
1066 set_value_pointed_to_offset (struct value
*value
, int val
)
1068 value
->pointed_to_offset
= val
;
1071 const struct lval_funcs
*
1072 value_computed_funcs (const struct value
*v
)
1074 gdb_assert (value_lval_const (v
) == lval_computed
);
1076 return v
->location
.computed
.funcs
;
1080 value_computed_closure (const struct value
*v
)
1082 gdb_assert (v
->lval
== lval_computed
);
1084 return v
->location
.computed
.closure
;
1088 deprecated_value_lval_hack (struct value
*value
)
1090 return &value
->lval
;
1094 value_lval_const (const struct value
*value
)
1100 value_address (const struct value
*value
)
1102 if (value
->lval
== lval_internalvar
1103 || value
->lval
== lval_internalvar_component
)
1105 return value
->location
.address
+ value
->offset
;
1109 value_raw_address (struct value
*value
)
1111 if (value
->lval
== lval_internalvar
1112 || value
->lval
== lval_internalvar_component
)
1114 return value
->location
.address
;
1118 set_value_address (struct value
*value
, CORE_ADDR addr
)
1120 gdb_assert (value
->lval
!= lval_internalvar
1121 && value
->lval
!= lval_internalvar_component
);
1122 value
->location
.address
= addr
;
1125 struct internalvar
**
1126 deprecated_value_internalvar_hack (struct value
*value
)
1128 return &value
->location
.internalvar
;
1132 deprecated_value_frame_id_hack (struct value
*value
)
1134 return &value
->frame_id
;
1138 deprecated_value_regnum_hack (struct value
*value
)
1140 return &value
->regnum
;
1144 deprecated_value_modifiable (struct value
*value
)
1146 return value
->modifiable
;
1149 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1151 value
->modifiable
= modifiable
;
1154 /* Return a mark in the value chain. All values allocated after the
1155 mark is obtained (except for those released) are subject to being freed
1156 if a subsequent value_free_to_mark is passed the mark. */
1163 /* Take a reference to VAL. VAL will not be deallocated until all
1164 references are released. */
1167 value_incref (struct value
*val
)
1169 val
->reference_count
++;
1172 /* Release a reference to VAL, which was acquired with value_incref.
1173 This function is also called to deallocate values from the value
1177 value_free (struct value
*val
)
1181 gdb_assert (val
->reference_count
> 0);
1182 val
->reference_count
--;
1183 if (val
->reference_count
> 0)
1186 /* If there's an associated parent value, drop our reference to
1188 if (val
->parent
!= NULL
)
1189 value_free (val
->parent
);
1191 if (VALUE_LVAL (val
) == lval_computed
)
1193 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1195 if (funcs
->free_closure
)
1196 funcs
->free_closure (val
);
1199 xfree (val
->contents
);
1200 VEC_free (range_s
, val
->unavailable
);
1205 /* Free all values allocated since MARK was obtained by value_mark
1206 (except for those released). */
1208 value_free_to_mark (struct value
*mark
)
1213 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1222 /* Free all the values that have been allocated (except for those released).
1223 Call after each command, successful or not.
1224 In practice this is called before each command, which is sufficient. */
1227 free_all_values (void)
1232 for (val
= all_values
; val
; val
= next
)
1242 /* Frees all the elements in a chain of values. */
1245 free_value_chain (struct value
*v
)
1251 next
= value_next (v
);
1256 /* Remove VAL from the chain all_values
1257 so it will not be freed automatically. */
1260 release_value (struct value
*val
)
1264 if (all_values
== val
)
1266 all_values
= val
->next
;
1272 for (v
= all_values
; v
; v
= v
->next
)
1276 v
->next
= val
->next
;
1284 /* If the value is not already released, release it.
1285 If the value is already released, increment its reference count.
1286 That is, this function ensures that the value is released from the
1287 value chain and that the caller owns a reference to it. */
1290 release_value_or_incref (struct value
*val
)
1295 release_value (val
);
1298 /* Release all values up to mark */
1300 value_release_to_mark (struct value
*mark
)
1305 for (val
= next
= all_values
; next
; next
= next
->next
)
1307 if (next
->next
== mark
)
1309 all_values
= next
->next
;
1319 /* Return a copy of the value ARG.
1320 It contains the same contents, for same memory address,
1321 but it's a different block of storage. */
1324 value_copy (struct value
*arg
)
1326 struct type
*encl_type
= value_enclosing_type (arg
);
1329 if (value_lazy (arg
))
1330 val
= allocate_value_lazy (encl_type
);
1332 val
= allocate_value (encl_type
);
1333 val
->type
= arg
->type
;
1334 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1335 val
->location
= arg
->location
;
1336 val
->offset
= arg
->offset
;
1337 val
->bitpos
= arg
->bitpos
;
1338 val
->bitsize
= arg
->bitsize
;
1339 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1340 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1341 val
->lazy
= arg
->lazy
;
1342 val
->optimized_out
= arg
->optimized_out
;
1343 val
->embedded_offset
= value_embedded_offset (arg
);
1344 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1345 val
->modifiable
= arg
->modifiable
;
1346 if (!value_lazy (val
))
1348 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1349 TYPE_LENGTH (value_enclosing_type (arg
)));
1352 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1353 val
->parent
= arg
->parent
;
1355 value_incref (val
->parent
);
1356 if (VALUE_LVAL (val
) == lval_computed
)
1358 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1360 if (funcs
->copy_closure
)
1361 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1366 /* Return a version of ARG that is non-lvalue. */
1369 value_non_lval (struct value
*arg
)
1371 if (VALUE_LVAL (arg
) != not_lval
)
1373 struct type
*enc_type
= value_enclosing_type (arg
);
1374 struct value
*val
= allocate_value (enc_type
);
1376 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1377 TYPE_LENGTH (enc_type
));
1378 val
->type
= arg
->type
;
1379 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1380 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1387 set_value_component_location (struct value
*component
,
1388 const struct value
*whole
)
1390 if (whole
->lval
== lval_internalvar
)
1391 VALUE_LVAL (component
) = lval_internalvar_component
;
1393 VALUE_LVAL (component
) = whole
->lval
;
1395 component
->location
= whole
->location
;
1396 if (whole
->lval
== lval_computed
)
1398 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1400 if (funcs
->copy_closure
)
1401 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1406 /* Access to the value history. */
1408 /* Record a new value in the value history.
1409 Returns the absolute history index of the entry.
1410 Result of -1 indicates the value was not saved; otherwise it is the
1411 value history index of this new item. */
1414 record_latest_value (struct value
*val
)
1418 /* We don't want this value to have anything to do with the inferior anymore.
1419 In particular, "set $1 = 50" should not affect the variable from which
1420 the value was taken, and fast watchpoints should be able to assume that
1421 a value on the value history never changes. */
1422 if (value_lazy (val
))
1423 value_fetch_lazy (val
);
1424 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1425 from. This is a bit dubious, because then *&$1 does not just return $1
1426 but the current contents of that location. c'est la vie... */
1427 val
->modifiable
= 0;
1428 release_value (val
);
1430 /* Here we treat value_history_count as origin-zero
1431 and applying to the value being stored now. */
1433 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1436 struct value_history_chunk
*new
1437 = (struct value_history_chunk
*)
1439 xmalloc (sizeof (struct value_history_chunk
));
1440 memset (new->values
, 0, sizeof new->values
);
1441 new->next
= value_history_chain
;
1442 value_history_chain
= new;
1445 value_history_chain
->values
[i
] = val
;
1447 /* Now we regard value_history_count as origin-one
1448 and applying to the value just stored. */
1450 return ++value_history_count
;
1453 /* Return a copy of the value in the history with sequence number NUM. */
1456 access_value_history (int num
)
1458 struct value_history_chunk
*chunk
;
1463 absnum
+= value_history_count
;
1468 error (_("The history is empty."));
1470 error (_("There is only one value in the history."));
1472 error (_("History does not go back to $$%d."), -num
);
1474 if (absnum
> value_history_count
)
1475 error (_("History has not yet reached $%d."), absnum
);
1479 /* Now absnum is always absolute and origin zero. */
1481 chunk
= value_history_chain
;
1482 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1483 - absnum
/ VALUE_HISTORY_CHUNK
;
1485 chunk
= chunk
->next
;
1487 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1491 show_values (char *num_exp
, int from_tty
)
1499 /* "show values +" should print from the stored position.
1500 "show values <exp>" should print around value number <exp>. */
1501 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1502 num
= parse_and_eval_long (num_exp
) - 5;
1506 /* "show values" means print the last 10 values. */
1507 num
= value_history_count
- 9;
1513 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1515 struct value_print_options opts
;
1517 val
= access_value_history (i
);
1518 printf_filtered (("$%d = "), i
);
1519 get_user_print_options (&opts
);
1520 value_print (val
, gdb_stdout
, &opts
);
1521 printf_filtered (("\n"));
1524 /* The next "show values +" should start after what we just printed. */
1527 /* Hitting just return after this command should do the same thing as
1528 "show values +". If num_exp is null, this is unnecessary, since
1529 "show values +" is not useful after "show values". */
1530 if (from_tty
&& num_exp
)
1537 /* Internal variables. These are variables within the debugger
1538 that hold values assigned by debugger commands.
1539 The user refers to them with a '$' prefix
1540 that does not appear in the variable names stored internally. */
1544 struct internalvar
*next
;
1547 /* We support various different kinds of content of an internal variable.
1548 enum internalvar_kind specifies the kind, and union internalvar_data
1549 provides the data associated with this particular kind. */
1551 enum internalvar_kind
1553 /* The internal variable is empty. */
1556 /* The value of the internal variable is provided directly as
1557 a GDB value object. */
1560 /* A fresh value is computed via a call-back routine on every
1561 access to the internal variable. */
1562 INTERNALVAR_MAKE_VALUE
,
1564 /* The internal variable holds a GDB internal convenience function. */
1565 INTERNALVAR_FUNCTION
,
1567 /* The variable holds an integer value. */
1568 INTERNALVAR_INTEGER
,
1570 /* The variable holds a GDB-provided string. */
1575 union internalvar_data
1577 /* A value object used with INTERNALVAR_VALUE. */
1578 struct value
*value
;
1580 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1581 internalvar_make_value make_value
;
1583 /* The internal function used with INTERNALVAR_FUNCTION. */
1586 struct internal_function
*function
;
1587 /* True if this is the canonical name for the function. */
1591 /* An integer value used with INTERNALVAR_INTEGER. */
1594 /* If type is non-NULL, it will be used as the type to generate
1595 a value for this internal variable. If type is NULL, a default
1596 integer type for the architecture is used. */
1601 /* A string value used with INTERNALVAR_STRING. */
1606 static struct internalvar
*internalvars
;
1608 /* If the variable does not already exist create it and give it the
1609 value given. If no value is given then the default is zero. */
1611 init_if_undefined_command (char* args
, int from_tty
)
1613 struct internalvar
* intvar
;
1615 /* Parse the expression - this is taken from set_command(). */
1616 struct expression
*expr
= parse_expression (args
);
1617 register struct cleanup
*old_chain
=
1618 make_cleanup (free_current_contents
, &expr
);
1620 /* Validate the expression.
1621 Was the expression an assignment?
1622 Or even an expression at all? */
1623 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1624 error (_("Init-if-undefined requires an assignment expression."));
1626 /* Extract the variable from the parsed expression.
1627 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1628 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1629 error (_("The first parameter to init-if-undefined "
1630 "should be a GDB variable."));
1631 intvar
= expr
->elts
[2].internalvar
;
1633 /* Only evaluate the expression if the lvalue is void.
1634 This may still fail if the expresssion is invalid. */
1635 if (intvar
->kind
== INTERNALVAR_VOID
)
1636 evaluate_expression (expr
);
1638 do_cleanups (old_chain
);
1642 /* Look up an internal variable with name NAME. NAME should not
1643 normally include a dollar sign.
1645 If the specified internal variable does not exist,
1646 the return value is NULL. */
1648 struct internalvar
*
1649 lookup_only_internalvar (const char *name
)
1651 struct internalvar
*var
;
1653 for (var
= internalvars
; var
; var
= var
->next
)
1654 if (strcmp (var
->name
, name
) == 0)
1661 /* Create an internal variable with name NAME and with a void value.
1662 NAME should not normally include a dollar sign. */
1664 struct internalvar
*
1665 create_internalvar (const char *name
)
1667 struct internalvar
*var
;
1669 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1670 var
->name
= concat (name
, (char *)NULL
);
1671 var
->kind
= INTERNALVAR_VOID
;
1672 var
->next
= internalvars
;
1677 /* Create an internal variable with name NAME and register FUN as the
1678 function that value_of_internalvar uses to create a value whenever
1679 this variable is referenced. NAME should not normally include a
1682 struct internalvar
*
1683 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1685 struct internalvar
*var
= create_internalvar (name
);
1687 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1688 var
->u
.make_value
= fun
;
1692 /* Look up an internal variable with name NAME. NAME should not
1693 normally include a dollar sign.
1695 If the specified internal variable does not exist,
1696 one is created, with a void value. */
1698 struct internalvar
*
1699 lookup_internalvar (const char *name
)
1701 struct internalvar
*var
;
1703 var
= lookup_only_internalvar (name
);
1707 return create_internalvar (name
);
1710 /* Return current value of internal variable VAR. For variables that
1711 are not inherently typed, use a value type appropriate for GDBARCH. */
1714 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1717 struct trace_state_variable
*tsv
;
1719 /* If there is a trace state variable of the same name, assume that
1720 is what we really want to see. */
1721 tsv
= find_trace_state_variable (var
->name
);
1724 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1726 if (tsv
->value_known
)
1727 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1730 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1736 case INTERNALVAR_VOID
:
1737 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1740 case INTERNALVAR_FUNCTION
:
1741 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1744 case INTERNALVAR_INTEGER
:
1745 if (!var
->u
.integer
.type
)
1746 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1747 var
->u
.integer
.val
);
1749 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1752 case INTERNALVAR_STRING
:
1753 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1754 builtin_type (gdbarch
)->builtin_char
);
1757 case INTERNALVAR_VALUE
:
1758 val
= value_copy (var
->u
.value
);
1759 if (value_lazy (val
))
1760 value_fetch_lazy (val
);
1763 case INTERNALVAR_MAKE_VALUE
:
1764 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1768 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1771 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1772 on this value go back to affect the original internal variable.
1774 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1775 no underlying modifyable state in the internal variable.
1777 Likewise, if the variable's value is a computed lvalue, we want
1778 references to it to produce another computed lvalue, where
1779 references and assignments actually operate through the
1780 computed value's functions.
1782 This means that internal variables with computed values
1783 behave a little differently from other internal variables:
1784 assignments to them don't just replace the previous value
1785 altogether. At the moment, this seems like the behavior we
1788 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1789 && val
->lval
!= lval_computed
)
1791 VALUE_LVAL (val
) = lval_internalvar
;
1792 VALUE_INTERNALVAR (val
) = var
;
1799 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1801 if (var
->kind
== INTERNALVAR_INTEGER
)
1803 *result
= var
->u
.integer
.val
;
1807 if (var
->kind
== INTERNALVAR_VALUE
)
1809 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1811 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1813 *result
= value_as_long (var
->u
.value
);
1822 get_internalvar_function (struct internalvar
*var
,
1823 struct internal_function
**result
)
1827 case INTERNALVAR_FUNCTION
:
1828 *result
= var
->u
.fn
.function
;
1837 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1838 int bitsize
, struct value
*newval
)
1844 case INTERNALVAR_VALUE
:
1845 addr
= value_contents_writeable (var
->u
.value
);
1848 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1849 value_as_long (newval
), bitpos
, bitsize
);
1851 memcpy (addr
+ offset
, value_contents (newval
),
1852 TYPE_LENGTH (value_type (newval
)));
1856 /* We can never get a component of any other kind. */
1857 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1862 set_internalvar (struct internalvar
*var
, struct value
*val
)
1864 enum internalvar_kind new_kind
;
1865 union internalvar_data new_data
= { 0 };
1867 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1868 error (_("Cannot overwrite convenience function %s"), var
->name
);
1870 /* Prepare new contents. */
1871 switch (TYPE_CODE (check_typedef (value_type (val
))))
1873 case TYPE_CODE_VOID
:
1874 new_kind
= INTERNALVAR_VOID
;
1877 case TYPE_CODE_INTERNAL_FUNCTION
:
1878 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1879 new_kind
= INTERNALVAR_FUNCTION
;
1880 get_internalvar_function (VALUE_INTERNALVAR (val
),
1881 &new_data
.fn
.function
);
1882 /* Copies created here are never canonical. */
1886 new_kind
= INTERNALVAR_VALUE
;
1887 new_data
.value
= value_copy (val
);
1888 new_data
.value
->modifiable
= 1;
1890 /* Force the value to be fetched from the target now, to avoid problems
1891 later when this internalvar is referenced and the target is gone or
1893 if (value_lazy (new_data
.value
))
1894 value_fetch_lazy (new_data
.value
);
1896 /* Release the value from the value chain to prevent it from being
1897 deleted by free_all_values. From here on this function should not
1898 call error () until new_data is installed into the var->u to avoid
1900 release_value (new_data
.value
);
1904 /* Clean up old contents. */
1905 clear_internalvar (var
);
1908 var
->kind
= new_kind
;
1910 /* End code which must not call error(). */
1914 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1916 /* Clean up old contents. */
1917 clear_internalvar (var
);
1919 var
->kind
= INTERNALVAR_INTEGER
;
1920 var
->u
.integer
.type
= NULL
;
1921 var
->u
.integer
.val
= l
;
1925 set_internalvar_string (struct internalvar
*var
, const char *string
)
1927 /* Clean up old contents. */
1928 clear_internalvar (var
);
1930 var
->kind
= INTERNALVAR_STRING
;
1931 var
->u
.string
= xstrdup (string
);
1935 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1937 /* Clean up old contents. */
1938 clear_internalvar (var
);
1940 var
->kind
= INTERNALVAR_FUNCTION
;
1941 var
->u
.fn
.function
= f
;
1942 var
->u
.fn
.canonical
= 1;
1943 /* Variables installed here are always the canonical version. */
1947 clear_internalvar (struct internalvar
*var
)
1949 /* Clean up old contents. */
1952 case INTERNALVAR_VALUE
:
1953 value_free (var
->u
.value
);
1956 case INTERNALVAR_STRING
:
1957 xfree (var
->u
.string
);
1964 /* Reset to void kind. */
1965 var
->kind
= INTERNALVAR_VOID
;
1969 internalvar_name (struct internalvar
*var
)
1974 static struct internal_function
*
1975 create_internal_function (const char *name
,
1976 internal_function_fn handler
, void *cookie
)
1978 struct internal_function
*ifn
= XNEW (struct internal_function
);
1980 ifn
->name
= xstrdup (name
);
1981 ifn
->handler
= handler
;
1982 ifn
->cookie
= cookie
;
1987 value_internal_function_name (struct value
*val
)
1989 struct internal_function
*ifn
;
1992 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1993 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
1994 gdb_assert (result
);
2000 call_internal_function (struct gdbarch
*gdbarch
,
2001 const struct language_defn
*language
,
2002 struct value
*func
, int argc
, struct value
**argv
)
2004 struct internal_function
*ifn
;
2007 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2008 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2009 gdb_assert (result
);
2011 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2014 /* The 'function' command. This does nothing -- it is just a
2015 placeholder to let "help function NAME" work. This is also used as
2016 the implementation of the sub-command that is created when
2017 registering an internal function. */
2019 function_command (char *command
, int from_tty
)
2024 /* Clean up if an internal function's command is destroyed. */
2026 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2032 /* Add a new internal function. NAME is the name of the function; DOC
2033 is a documentation string describing the function. HANDLER is
2034 called when the function is invoked. COOKIE is an arbitrary
2035 pointer which is passed to HANDLER and is intended for "user
2038 add_internal_function (const char *name
, const char *doc
,
2039 internal_function_fn handler
, void *cookie
)
2041 struct cmd_list_element
*cmd
;
2042 struct internal_function
*ifn
;
2043 struct internalvar
*var
= lookup_internalvar (name
);
2045 ifn
= create_internal_function (name
, handler
, cookie
);
2046 set_internalvar_function (var
, ifn
);
2048 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2050 cmd
->destroyer
= function_destroyer
;
2053 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2054 prevent cycles / duplicates. */
2057 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2058 htab_t copied_types
)
2060 if (TYPE_OBJFILE (value
->type
) == objfile
)
2061 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2063 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2064 value
->enclosing_type
= copy_type_recursive (objfile
,
2065 value
->enclosing_type
,
2069 /* Likewise for internal variable VAR. */
2072 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2073 htab_t copied_types
)
2077 case INTERNALVAR_INTEGER
:
2078 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2080 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2083 case INTERNALVAR_VALUE
:
2084 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2089 /* Update the internal variables and value history when OBJFILE is
2090 discarded; we must copy the types out of the objfile. New global types
2091 will be created for every convenience variable which currently points to
2092 this objfile's types, and the convenience variables will be adjusted to
2093 use the new global types. */
2096 preserve_values (struct objfile
*objfile
)
2098 htab_t copied_types
;
2099 struct value_history_chunk
*cur
;
2100 struct internalvar
*var
;
2103 /* Create the hash table. We allocate on the objfile's obstack, since
2104 it is soon to be deleted. */
2105 copied_types
= create_copied_types_hash (objfile
);
2107 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2108 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2110 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2112 for (var
= internalvars
; var
; var
= var
->next
)
2113 preserve_one_internalvar (var
, objfile
, copied_types
);
2115 preserve_python_values (objfile
, copied_types
);
2117 htab_delete (copied_types
);
2121 show_convenience (char *ignore
, int from_tty
)
2123 struct gdbarch
*gdbarch
= get_current_arch ();
2124 struct internalvar
*var
;
2126 struct value_print_options opts
;
2128 get_user_print_options (&opts
);
2129 for (var
= internalvars
; var
; var
= var
->next
)
2131 volatile struct gdb_exception ex
;
2137 printf_filtered (("$%s = "), var
->name
);
2139 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2143 val
= value_of_internalvar (gdbarch
, var
);
2144 value_print (val
, gdb_stdout
, &opts
);
2147 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2148 printf_filtered (("\n"));
2151 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2152 "Convenience variables have "
2153 "names starting with \"$\";\n"
2154 "use \"set\" as in \"set "
2155 "$foo = 5\" to define them.\n"));
2158 /* Extract a value as a C number (either long or double).
2159 Knows how to convert fixed values to double, or
2160 floating values to long.
2161 Does not deallocate the value. */
2164 value_as_long (struct value
*val
)
2166 /* This coerces arrays and functions, which is necessary (e.g.
2167 in disassemble_command). It also dereferences references, which
2168 I suspect is the most logical thing to do. */
2169 val
= coerce_array (val
);
2170 return unpack_long (value_type (val
), value_contents (val
));
2174 value_as_double (struct value
*val
)
2179 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2181 error (_("Invalid floating value found in program."));
2185 /* Extract a value as a C pointer. Does not deallocate the value.
2186 Note that val's type may not actually be a pointer; value_as_long
2187 handles all the cases. */
2189 value_as_address (struct value
*val
)
2191 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2193 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2194 whether we want this to be true eventually. */
2196 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2197 non-address (e.g. argument to "signal", "info break", etc.), or
2198 for pointers to char, in which the low bits *are* significant. */
2199 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2202 /* There are several targets (IA-64, PowerPC, and others) which
2203 don't represent pointers to functions as simply the address of
2204 the function's entry point. For example, on the IA-64, a
2205 function pointer points to a two-word descriptor, generated by
2206 the linker, which contains the function's entry point, and the
2207 value the IA-64 "global pointer" register should have --- to
2208 support position-independent code. The linker generates
2209 descriptors only for those functions whose addresses are taken.
2211 On such targets, it's difficult for GDB to convert an arbitrary
2212 function address into a function pointer; it has to either find
2213 an existing descriptor for that function, or call malloc and
2214 build its own. On some targets, it is impossible for GDB to
2215 build a descriptor at all: the descriptor must contain a jump
2216 instruction; data memory cannot be executed; and code memory
2219 Upon entry to this function, if VAL is a value of type `function'
2220 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2221 value_address (val) is the address of the function. This is what
2222 you'll get if you evaluate an expression like `main'. The call
2223 to COERCE_ARRAY below actually does all the usual unary
2224 conversions, which includes converting values of type `function'
2225 to `pointer to function'. This is the challenging conversion
2226 discussed above. Then, `unpack_long' will convert that pointer
2227 back into an address.
2229 So, suppose the user types `disassemble foo' on an architecture
2230 with a strange function pointer representation, on which GDB
2231 cannot build its own descriptors, and suppose further that `foo'
2232 has no linker-built descriptor. The address->pointer conversion
2233 will signal an error and prevent the command from running, even
2234 though the next step would have been to convert the pointer
2235 directly back into the same address.
2237 The following shortcut avoids this whole mess. If VAL is a
2238 function, just return its address directly. */
2239 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2240 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2241 return value_address (val
);
2243 val
= coerce_array (val
);
2245 /* Some architectures (e.g. Harvard), map instruction and data
2246 addresses onto a single large unified address space. For
2247 instance: An architecture may consider a large integer in the
2248 range 0x10000000 .. 0x1000ffff to already represent a data
2249 addresses (hence not need a pointer to address conversion) while
2250 a small integer would still need to be converted integer to
2251 pointer to address. Just assume such architectures handle all
2252 integer conversions in a single function. */
2256 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2257 must admonish GDB hackers to make sure its behavior matches the
2258 compiler's, whenever possible.
2260 In general, I think GDB should evaluate expressions the same way
2261 the compiler does. When the user copies an expression out of
2262 their source code and hands it to a `print' command, they should
2263 get the same value the compiler would have computed. Any
2264 deviation from this rule can cause major confusion and annoyance,
2265 and needs to be justified carefully. In other words, GDB doesn't
2266 really have the freedom to do these conversions in clever and
2269 AndrewC pointed out that users aren't complaining about how GDB
2270 casts integers to pointers; they are complaining that they can't
2271 take an address from a disassembly listing and give it to `x/i'.
2272 This is certainly important.
2274 Adding an architecture method like integer_to_address() certainly
2275 makes it possible for GDB to "get it right" in all circumstances
2276 --- the target has complete control over how things get done, so
2277 people can Do The Right Thing for their target without breaking
2278 anyone else. The standard doesn't specify how integers get
2279 converted to pointers; usually, the ABI doesn't either, but
2280 ABI-specific code is a more reasonable place to handle it. */
2282 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2283 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2284 && gdbarch_integer_to_address_p (gdbarch
))
2285 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2286 value_contents (val
));
2288 return unpack_long (value_type (val
), value_contents (val
));
2292 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2293 as a long, or as a double, assuming the raw data is described
2294 by type TYPE. Knows how to convert different sizes of values
2295 and can convert between fixed and floating point. We don't assume
2296 any alignment for the raw data. Return value is in host byte order.
2298 If you want functions and arrays to be coerced to pointers, and
2299 references to be dereferenced, call value_as_long() instead.
2301 C++: It is assumed that the front-end has taken care of
2302 all matters concerning pointers to members. A pointer
2303 to member which reaches here is considered to be equivalent
2304 to an INT (or some size). After all, it is only an offset. */
2307 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2309 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2310 enum type_code code
= TYPE_CODE (type
);
2311 int len
= TYPE_LENGTH (type
);
2312 int nosign
= TYPE_UNSIGNED (type
);
2316 case TYPE_CODE_TYPEDEF
:
2317 return unpack_long (check_typedef (type
), valaddr
);
2318 case TYPE_CODE_ENUM
:
2319 case TYPE_CODE_FLAGS
:
2320 case TYPE_CODE_BOOL
:
2322 case TYPE_CODE_CHAR
:
2323 case TYPE_CODE_RANGE
:
2324 case TYPE_CODE_MEMBERPTR
:
2326 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2328 return extract_signed_integer (valaddr
, len
, byte_order
);
2331 return extract_typed_floating (valaddr
, type
);
2333 case TYPE_CODE_DECFLOAT
:
2334 /* libdecnumber has a function to convert from decimal to integer, but
2335 it doesn't work when the decimal number has a fractional part. */
2336 return decimal_to_doublest (valaddr
, len
, byte_order
);
2340 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2341 whether we want this to be true eventually. */
2342 return extract_typed_address (valaddr
, type
);
2345 error (_("Value can't be converted to integer."));
2347 return 0; /* Placate lint. */
2350 /* Return a double value from the specified type and address.
2351 INVP points to an int which is set to 0 for valid value,
2352 1 for invalid value (bad float format). In either case,
2353 the returned double is OK to use. Argument is in target
2354 format, result is in host format. */
2357 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2359 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2360 enum type_code code
;
2364 *invp
= 0; /* Assume valid. */
2365 CHECK_TYPEDEF (type
);
2366 code
= TYPE_CODE (type
);
2367 len
= TYPE_LENGTH (type
);
2368 nosign
= TYPE_UNSIGNED (type
);
2369 if (code
== TYPE_CODE_FLT
)
2371 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2372 floating-point value was valid (using the macro
2373 INVALID_FLOAT). That test/macro have been removed.
2375 It turns out that only the VAX defined this macro and then
2376 only in a non-portable way. Fixing the portability problem
2377 wouldn't help since the VAX floating-point code is also badly
2378 bit-rotten. The target needs to add definitions for the
2379 methods gdbarch_float_format and gdbarch_double_format - these
2380 exactly describe the target floating-point format. The
2381 problem here is that the corresponding floatformat_vax_f and
2382 floatformat_vax_d values these methods should be set to are
2383 also not defined either. Oops!
2385 Hopefully someone will add both the missing floatformat
2386 definitions and the new cases for floatformat_is_valid (). */
2388 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2394 return extract_typed_floating (valaddr
, type
);
2396 else if (code
== TYPE_CODE_DECFLOAT
)
2397 return decimal_to_doublest (valaddr
, len
, byte_order
);
2400 /* Unsigned -- be sure we compensate for signed LONGEST. */
2401 return (ULONGEST
) unpack_long (type
, valaddr
);
2405 /* Signed -- we are OK with unpack_long. */
2406 return unpack_long (type
, valaddr
);
2410 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2411 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2412 We don't assume any alignment for the raw data. Return value is in
2415 If you want functions and arrays to be coerced to pointers, and
2416 references to be dereferenced, call value_as_address() instead.
2418 C++: It is assumed that the front-end has taken care of
2419 all matters concerning pointers to members. A pointer
2420 to member which reaches here is considered to be equivalent
2421 to an INT (or some size). After all, it is only an offset. */
2424 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2426 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2427 whether we want this to be true eventually. */
2428 return unpack_long (type
, valaddr
);
2432 /* Get the value of the FIELDNO'th field (which must be static) of
2433 TYPE. Return NULL if the field doesn't exist or has been
2437 value_static_field (struct type
*type
, int fieldno
)
2439 struct value
*retval
;
2441 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2443 case FIELD_LOC_KIND_PHYSADDR
:
2444 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2445 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2447 case FIELD_LOC_KIND_PHYSNAME
:
2449 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2450 /* TYPE_FIELD_NAME (type, fieldno); */
2451 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2455 /* With some compilers, e.g. HP aCC, static data members are
2456 reported as non-debuggable symbols. */
2457 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2464 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2465 SYMBOL_VALUE_ADDRESS (msym
));
2469 retval
= value_of_variable (sym
, NULL
);
2473 gdb_assert_not_reached ("unexpected field location kind");
2479 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2480 You have to be careful here, since the size of the data area for the value
2481 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2482 than the old enclosing type, you have to allocate more space for the
2486 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2488 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2490 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2492 val
->enclosing_type
= new_encl_type
;
2495 /* Given a value ARG1 (offset by OFFSET bytes)
2496 of a struct or union type ARG_TYPE,
2497 extract and return the value of one of its (non-static) fields.
2498 FIELDNO says which field. */
2501 value_primitive_field (struct value
*arg1
, int offset
,
2502 int fieldno
, struct type
*arg_type
)
2507 CHECK_TYPEDEF (arg_type
);
2508 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2510 /* Call check_typedef on our type to make sure that, if TYPE
2511 is a TYPE_CODE_TYPEDEF, its length is set to the length
2512 of the target type instead of zero. However, we do not
2513 replace the typedef type by the target type, because we want
2514 to keep the typedef in order to be able to print the type
2515 description correctly. */
2516 check_typedef (type
);
2518 if (value_optimized_out (arg1
))
2519 v
= allocate_optimized_out_value (type
);
2520 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2522 /* Handle packed fields.
2524 Create a new value for the bitfield, with bitpos and bitsize
2525 set. If possible, arrange offset and bitpos so that we can
2526 do a single aligned read of the size of the containing type.
2527 Otherwise, adjust offset to the byte containing the first
2528 bit. Assume that the address, offset, and embedded offset
2529 are sufficiently aligned. */
2531 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2532 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2534 v
= allocate_value_lazy (type
);
2535 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2536 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2537 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2538 v
->bitpos
= bitpos
% container_bitsize
;
2540 v
->bitpos
= bitpos
% 8;
2541 v
->offset
= (value_embedded_offset (arg1
)
2543 + (bitpos
- v
->bitpos
) / 8);
2545 value_incref (v
->parent
);
2546 if (!value_lazy (arg1
))
2547 value_fetch_lazy (v
);
2549 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2551 /* This field is actually a base subobject, so preserve the
2552 entire object's contents for later references to virtual
2555 /* Lazy register values with offsets are not supported. */
2556 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2557 value_fetch_lazy (arg1
);
2559 if (value_lazy (arg1
))
2560 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2563 v
= allocate_value (value_enclosing_type (arg1
));
2564 value_contents_copy_raw (v
, 0, arg1
, 0,
2565 TYPE_LENGTH (value_enclosing_type (arg1
)));
2568 v
->offset
= value_offset (arg1
);
2569 v
->embedded_offset
= (offset
+ value_embedded_offset (arg1
)
2570 + TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8);
2574 /* Plain old data member */
2575 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2577 /* Lazy register values with offsets are not supported. */
2578 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2579 value_fetch_lazy (arg1
);
2581 if (value_lazy (arg1
))
2582 v
= allocate_value_lazy (type
);
2585 v
= allocate_value (type
);
2586 value_contents_copy_raw (v
, value_embedded_offset (v
),
2587 arg1
, value_embedded_offset (arg1
) + offset
,
2588 TYPE_LENGTH (type
));
2590 v
->offset
= (value_offset (arg1
) + offset
2591 + value_embedded_offset (arg1
));
2593 set_value_component_location (v
, arg1
);
2594 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2595 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2599 /* Given a value ARG1 of a struct or union type,
2600 extract and return the value of one of its (non-static) fields.
2601 FIELDNO says which field. */
2604 value_field (struct value
*arg1
, int fieldno
)
2606 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2609 /* Return a non-virtual function as a value.
2610 F is the list of member functions which contains the desired method.
2611 J is an index into F which provides the desired method.
2613 We only use the symbol for its address, so be happy with either a
2614 full symbol or a minimal symbol. */
2617 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2618 int j
, struct type
*type
,
2622 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2623 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2625 struct minimal_symbol
*msym
;
2627 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2634 gdb_assert (sym
== NULL
);
2635 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2640 v
= allocate_value (ftype
);
2643 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2647 /* The minimal symbol might point to a function descriptor;
2648 resolve it to the actual code address instead. */
2649 struct objfile
*objfile
= msymbol_objfile (msym
);
2650 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2652 set_value_address (v
,
2653 gdbarch_convert_from_func_ptr_addr
2654 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2659 if (type
!= value_type (*arg1p
))
2660 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2661 value_addr (*arg1p
)));
2663 /* Move the `this' pointer according to the offset.
2664 VALUE_OFFSET (*arg1p) += offset; */
2672 /* Helper function for both unpack_value_bits_as_long and
2673 unpack_bits_as_long. See those functions for more details on the
2674 interface; the only difference is that this function accepts either
2675 a NULL or a non-NULL ORIGINAL_VALUE. */
2678 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2679 int embedded_offset
, int bitpos
, int bitsize
,
2680 const struct value
*original_value
,
2683 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2690 /* Read the minimum number of bytes required; there may not be
2691 enough bytes to read an entire ULONGEST. */
2692 CHECK_TYPEDEF (field_type
);
2694 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2696 bytes_read
= TYPE_LENGTH (field_type
);
2698 read_offset
= bitpos
/ 8;
2700 if (original_value
!= NULL
2701 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2705 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2706 bytes_read
, byte_order
);
2708 /* Extract bits. See comment above. */
2710 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2711 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2713 lsbcount
= (bitpos
% 8);
2716 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2717 If the field is signed, and is negative, then sign extend. */
2719 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2721 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2723 if (!TYPE_UNSIGNED (field_type
))
2725 if (val
& (valmask
^ (valmask
>> 1)))
2736 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2737 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2738 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2739 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2742 Returns false if the value contents are unavailable, otherwise
2743 returns true, indicating a valid value has been stored in *RESULT.
2745 Extracting bits depends on endianness of the machine. Compute the
2746 number of least significant bits to discard. For big endian machines,
2747 we compute the total number of bits in the anonymous object, subtract
2748 off the bit count from the MSB of the object to the MSB of the
2749 bitfield, then the size of the bitfield, which leaves the LSB discard
2750 count. For little endian machines, the discard count is simply the
2751 number of bits from the LSB of the anonymous object to the LSB of the
2754 If the field is signed, we also do sign extension. */
2757 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2758 int embedded_offset
, int bitpos
, int bitsize
,
2759 const struct value
*original_value
,
2762 gdb_assert (original_value
!= NULL
);
2764 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2765 bitpos
, bitsize
, original_value
, result
);
2769 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2770 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2771 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2775 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2776 int embedded_offset
, int fieldno
,
2777 const struct value
*val
, LONGEST
*result
)
2779 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2780 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2781 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2783 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2784 bitpos
, bitsize
, val
,
2788 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2789 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2790 ORIGINAL_VALUE, which must not be NULL. See
2791 unpack_value_bits_as_long for more details. */
2794 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2795 int embedded_offset
, int fieldno
,
2796 const struct value
*val
, LONGEST
*result
)
2798 gdb_assert (val
!= NULL
);
2800 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2801 fieldno
, val
, result
);
2804 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2805 object at VALADDR. See unpack_value_bits_as_long for more details.
2806 This function differs from unpack_value_field_as_long in that it
2807 operates without a struct value object. */
2810 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2814 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2818 /* Return a new value with type TYPE, which is FIELDNO field of the
2819 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2820 of VAL. If the VAL's contents required to extract the bitfield
2821 from are unavailable, the new value is correspondingly marked as
2825 value_field_bitfield (struct type
*type
, int fieldno
,
2826 const gdb_byte
*valaddr
,
2827 int embedded_offset
, const struct value
*val
)
2831 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2834 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2835 struct value
*retval
= allocate_value (field_type
);
2836 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2841 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2845 /* Modify the value of a bitfield. ADDR points to a block of memory in
2846 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2847 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2848 indicate which bits (in target bit order) comprise the bitfield.
2849 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2850 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2853 modify_field (struct type
*type
, gdb_byte
*addr
,
2854 LONGEST fieldval
, int bitpos
, int bitsize
)
2856 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2858 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2861 /* Normalize BITPOS. */
2865 /* If a negative fieldval fits in the field in question, chop
2866 off the sign extension bits. */
2867 if ((~fieldval
& ~(mask
>> 1)) == 0)
2870 /* Warn if value is too big to fit in the field in question. */
2871 if (0 != (fieldval
& ~mask
))
2873 /* FIXME: would like to include fieldval in the message, but
2874 we don't have a sprintf_longest. */
2875 warning (_("Value does not fit in %d bits."), bitsize
);
2877 /* Truncate it, otherwise adjoining fields may be corrupted. */
2881 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2882 false valgrind reports. */
2884 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2885 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2887 /* Shifting for bit field depends on endianness of the target machine. */
2888 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2889 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2891 oword
&= ~(mask
<< bitpos
);
2892 oword
|= fieldval
<< bitpos
;
2894 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2897 /* Pack NUM into BUF using a target format of TYPE. */
2900 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2902 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2905 type
= check_typedef (type
);
2906 len
= TYPE_LENGTH (type
);
2908 switch (TYPE_CODE (type
))
2911 case TYPE_CODE_CHAR
:
2912 case TYPE_CODE_ENUM
:
2913 case TYPE_CODE_FLAGS
:
2914 case TYPE_CODE_BOOL
:
2915 case TYPE_CODE_RANGE
:
2916 case TYPE_CODE_MEMBERPTR
:
2917 store_signed_integer (buf
, len
, byte_order
, num
);
2922 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2926 error (_("Unexpected type (%d) encountered for integer constant."),
2932 /* Pack NUM into BUF using a target format of TYPE. */
2935 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2938 enum bfd_endian byte_order
;
2940 type
= check_typedef (type
);
2941 len
= TYPE_LENGTH (type
);
2942 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2944 switch (TYPE_CODE (type
))
2947 case TYPE_CODE_CHAR
:
2948 case TYPE_CODE_ENUM
:
2949 case TYPE_CODE_FLAGS
:
2950 case TYPE_CODE_BOOL
:
2951 case TYPE_CODE_RANGE
:
2952 case TYPE_CODE_MEMBERPTR
:
2953 store_unsigned_integer (buf
, len
, byte_order
, num
);
2958 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2962 error (_("Unexpected type (%d) encountered "
2963 "for unsigned integer constant."),
2969 /* Convert C numbers into newly allocated values. */
2972 value_from_longest (struct type
*type
, LONGEST num
)
2974 struct value
*val
= allocate_value (type
);
2976 pack_long (value_contents_raw (val
), type
, num
);
2981 /* Convert C unsigned numbers into newly allocated values. */
2984 value_from_ulongest (struct type
*type
, ULONGEST num
)
2986 struct value
*val
= allocate_value (type
);
2988 pack_unsigned_long (value_contents_raw (val
), type
, num
);
2994 /* Create a value representing a pointer of type TYPE to the address
2997 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
2999 struct value
*val
= allocate_value (type
);
3001 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3006 /* Create a value of type TYPE whose contents come from VALADDR, if it
3007 is non-null, and whose memory address (in the inferior) is
3011 value_from_contents_and_address (struct type
*type
,
3012 const gdb_byte
*valaddr
,
3017 if (valaddr
== NULL
)
3018 v
= allocate_value_lazy (type
);
3021 v
= allocate_value (type
);
3022 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3024 set_value_address (v
, address
);
3025 VALUE_LVAL (v
) = lval_memory
;
3029 /* Create a value of type TYPE holding the contents CONTENTS.
3030 The new value is `not_lval'. */
3033 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3035 struct value
*result
;
3037 result
= allocate_value (type
);
3038 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3043 value_from_double (struct type
*type
, DOUBLEST num
)
3045 struct value
*val
= allocate_value (type
);
3046 struct type
*base_type
= check_typedef (type
);
3047 enum type_code code
= TYPE_CODE (base_type
);
3049 if (code
== TYPE_CODE_FLT
)
3051 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3054 error (_("Unexpected type encountered for floating constant."));
3060 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3062 struct value
*val
= allocate_value (type
);
3064 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3068 /* Extract a value from the history file. Input will be of the form
3069 $digits or $$digits. See block comment above 'write_dollar_variable'
3073 value_from_history_ref (char *h
, char **endp
)
3085 /* Find length of numeral string. */
3086 for (; isdigit (h
[len
]); len
++)
3089 /* Make sure numeral string is not part of an identifier. */
3090 if (h
[len
] == '_' || isalpha (h
[len
]))
3093 /* Now collect the index value. */
3098 /* For some bizarre reason, "$$" is equivalent to "$$1",
3099 rather than to "$$0" as it ought to be! */
3104 index
= -strtol (&h
[2], endp
, 10);
3110 /* "$" is equivalent to "$0". */
3115 index
= strtol (&h
[1], endp
, 10);
3118 return access_value_history (index
);
3122 coerce_ref_if_computed (const struct value
*arg
)
3124 const struct lval_funcs
*funcs
;
3126 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3129 if (value_lval_const (arg
) != lval_computed
)
3132 funcs
= value_computed_funcs (arg
);
3133 if (funcs
->coerce_ref
== NULL
)
3136 return funcs
->coerce_ref (arg
);
3140 coerce_ref (struct value
*arg
)
3142 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3143 struct value
*retval
;
3145 retval
= coerce_ref_if_computed (arg
);
3149 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3152 return value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp
),
3153 unpack_pointer (value_type (arg
),
3154 value_contents (arg
)));
3158 coerce_array (struct value
*arg
)
3162 arg
= coerce_ref (arg
);
3163 type
= check_typedef (value_type (arg
));
3165 switch (TYPE_CODE (type
))
3167 case TYPE_CODE_ARRAY
:
3168 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3169 arg
= value_coerce_array (arg
);
3171 case TYPE_CODE_FUNC
:
3172 arg
= value_coerce_function (arg
);
3179 /* Return true if the function returning the specified type is using
3180 the convention of returning structures in memory (passing in the
3181 address as a hidden first parameter). */
3184 using_struct_return (struct gdbarch
*gdbarch
,
3185 struct type
*func_type
, struct type
*value_type
)
3187 enum type_code code
= TYPE_CODE (value_type
);
3189 if (code
== TYPE_CODE_ERROR
)
3190 error (_("Function return type unknown."));
3192 if (code
== TYPE_CODE_VOID
)
3193 /* A void return value is never in memory. See also corresponding
3194 code in "print_return_value". */
3197 /* Probe the architecture for the return-value convention. */
3198 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3200 != RETURN_VALUE_REGISTER_CONVENTION
);
3203 /* Set the initialized field in a value struct. */
3206 set_value_initialized (struct value
*val
, int status
)
3208 val
->initialized
= status
;
3211 /* Return the initialized field in a value struct. */
3214 value_initialized (struct value
*val
)
3216 return val
->initialized
;
3220 _initialize_values (void)
3222 add_cmd ("convenience", no_class
, show_convenience
, _("\
3223 Debugger convenience (\"$foo\") variables.\n\
3224 These variables are created when you assign them values;\n\
3225 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3227 A few convenience variables are given values automatically:\n\
3228 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3229 \"$__\" holds the contents of the last address examined with \"x\"."),
3232 add_cmd ("values", no_set_class
, show_values
, _("\
3233 Elements of value history around item number IDX (or last ten)."),
3236 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3237 Initialize a convenience variable if necessary.\n\
3238 init-if-undefined VARIABLE = EXPRESSION\n\
3239 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3240 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3241 VARIABLE is already initialized."));
3243 add_prefix_cmd ("function", no_class
, function_command
, _("\
3244 Placeholder command for showing help on convenience functions."),
3245 &functionlist
, "function ", 0, &cmdlist
);