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"
43 #include "python/python.h"
45 #include "tracepoint.h"
47 /* Prototypes for exported functions. */
49 void _initialize_values (void);
51 /* Definition of a user function. */
52 struct internal_function
54 /* The name of the function. It is a bit odd to have this in the
55 function itself -- the user might use a differently-named
56 convenience variable to hold the function. */
60 internal_function_fn handler
;
62 /* User data for the handler. */
66 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
70 /* Lowest offset in the range. */
73 /* Length of the range. */
77 typedef struct range range_s
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (int offset1
, int len1
,
86 int offset2
, int len2
)
90 l
= max (offset1
, offset2
);
91 h
= min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if the first argument is strictly less than the
96 second, useful for VEC_lower_bound. We keep ranges sorted by
97 offset and coalesce overlapping and contiguous ranges, so this just
98 compares the starting offset. */
101 range_lessthan (const range_s
*r1
, const range_s
*r2
)
103 return r1
->offset
< r2
->offset
;
106 /* Returns true if RANGES contains any range that overlaps [OFFSET,
110 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
115 what
.offset
= offset
;
116 what
.length
= length
;
118 /* We keep ranges sorted by offset and coalesce overlapping and
119 contiguous ranges, so to check if a range list contains a given
120 range, we can do a binary search for the position the given range
121 would be inserted if we only considered the starting OFFSET of
122 ranges. We call that position I. Since we also have LENGTH to
123 care for (this is a range afterall), we need to check if the
124 _previous_ range overlaps the I range. E.g.,
128 |---| |---| |------| ... |--|
133 In the case above, the binary search would return `I=1', meaning,
134 this OFFSET should be inserted at position 1, and the current
135 position 1 should be pushed further (and before 2). But, `0'
138 Then we need to check if the I range overlaps the I range itself.
143 |---| |---| |-------| ... |--|
149 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
153 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
155 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
159 if (i
< VEC_length (range_s
, ranges
))
161 struct range
*r
= VEC_index (range_s
, ranges
, i
);
163 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
170 static struct cmd_list_element
*functionlist
;
174 /* Type of value; either not an lval, or one of the various
175 different possible kinds of lval. */
178 /* Is it modifiable? Only relevant if lval != not_lval. */
181 /* Location of value (if lval). */
184 /* If lval == lval_memory, this is the address in the inferior.
185 If lval == lval_register, this is the byte offset into the
186 registers structure. */
189 /* Pointer to internal variable. */
190 struct internalvar
*internalvar
;
192 /* If lval == lval_computed, this is a set of function pointers
193 to use to access and describe the value, and a closure pointer
197 struct lval_funcs
*funcs
; /* Functions to call. */
198 void *closure
; /* Closure for those functions to use. */
202 /* Describes offset of a value within lval of a structure in bytes.
203 If lval == lval_memory, this is an offset to the address. If
204 lval == lval_register, this is a further offset from
205 location.address within the registers structure. Note also the
206 member embedded_offset below. */
209 /* Only used for bitfields; number of bits contained in them. */
212 /* Only used for bitfields; position of start of field. For
213 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
214 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
217 /* Only used for bitfields; the containing value. This allows a
218 single read from the target when displaying multiple
220 struct value
*parent
;
222 /* Frame register value is relative to. This will be described in
223 the lval enum above as "lval_register". */
224 struct frame_id frame_id
;
226 /* Type of the value. */
229 /* If a value represents a C++ object, then the `type' field gives
230 the object's compile-time type. If the object actually belongs
231 to some class derived from `type', perhaps with other base
232 classes and additional members, then `type' is just a subobject
233 of the real thing, and the full object is probably larger than
234 `type' would suggest.
236 If `type' is a dynamic class (i.e. one with a vtable), then GDB
237 can actually determine the object's run-time type by looking at
238 the run-time type information in the vtable. When this
239 information is available, we may elect to read in the entire
240 object, for several reasons:
242 - When printing the value, the user would probably rather see the
243 full object, not just the limited portion apparent from the
246 - If `type' has virtual base classes, then even printing `type'
247 alone may require reaching outside the `type' portion of the
248 object to wherever the virtual base class has been stored.
250 When we store the entire object, `enclosing_type' is the run-time
251 type -- the complete object -- and `embedded_offset' is the
252 offset of `type' within that larger type, in bytes. The
253 value_contents() macro takes `embedded_offset' into account, so
254 most GDB code continues to see the `type' portion of the value,
255 just as the inferior would.
257 If `type' is a pointer to an object, then `enclosing_type' is a
258 pointer to the object's run-time type, and `pointed_to_offset' is
259 the offset in bytes from the full object to the pointed-to object
260 -- that is, the value `embedded_offset' would have if we followed
261 the pointer and fetched the complete object. (I don't really see
262 the point. Why not just determine the run-time type when you
263 indirect, and avoid the special case? The contents don't matter
264 until you indirect anyway.)
266 If we're not doing anything fancy, `enclosing_type' is equal to
267 `type', and `embedded_offset' is zero, so everything works
269 struct type
*enclosing_type
;
271 int pointed_to_offset
;
273 /* Values are stored in a chain, so that they can be deleted easily
274 over calls to the inferior. Values assigned to internal
275 variables, put into the value history or exposed to Python are
276 taken off this list. */
279 /* Register number if the value is from a register. */
282 /* If zero, contents of this value are in the contents field. If
283 nonzero, contents are in inferior. If the lval field is lval_memory,
284 the contents are in inferior memory at location.address plus offset.
285 The lval field may also be lval_register.
287 WARNING: This field is used by the code which handles watchpoints
288 (see breakpoint.c) to decide whether a particular value can be
289 watched by hardware watchpoints. If the lazy flag is set for
290 some member of a value chain, it is assumed that this member of
291 the chain doesn't need to be watched as part of watching the
292 value itself. This is how GDB avoids watching the entire struct
293 or array when the user wants to watch a single struct member or
294 array element. If you ever change the way lazy flag is set and
295 reset, be sure to consider this use as well! */
298 /* If nonzero, this is the value of a variable which does not
299 actually exist in the program. */
302 /* If value is a variable, is it initialized or not. */
305 /* If value is from the stack. If this is set, read_stack will be
306 used instead of read_memory to enable extra caching. */
309 /* Actual contents of the value. Target byte-order. NULL or not
310 valid if lazy is nonzero. */
313 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
314 rather than available, since the common and default case is for a
315 value to be available. This is filled in at value read time. */
316 VEC(range_s
) *unavailable
;
318 /* The number of references to this value. When a value is created,
319 the value chain holds a reference, so REFERENCE_COUNT is 1. If
320 release_value is called, this value is removed from the chain but
321 the caller of release_value now has a reference to this value.
322 The caller must arrange for a call to value_free later. */
327 value_bytes_available (const struct value
*value
, int offset
, int length
)
329 gdb_assert (!value
->lazy
);
331 return !ranges_contain (value
->unavailable
, offset
, length
);
335 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
340 /* Insert the range sorted. If there's overlap or the new range
341 would be contiguous with an existing range, merge. */
343 newr
.offset
= offset
;
344 newr
.length
= length
;
346 /* Do a binary search for the position the given range would be
347 inserted if we only considered the starting OFFSET of ranges.
348 Call that position I. Since we also have LENGTH to care for
349 (this is a range afterall), we need to check if the _previous_
350 range overlaps the I range. E.g., calling R the new range:
352 #1 - overlaps with previous
356 |---| |---| |------| ... |--|
361 In the case #1 above, the binary search would return `I=1',
362 meaning, this OFFSET should be inserted at position 1, and the
363 current position 1 should be pushed further (and become 2). But,
364 note that `0' overlaps with R, so we want to merge them.
366 A similar consideration needs to be taken if the new range would
367 be contiguous with the previous range:
369 #2 - contiguous with previous
373 |--| |---| |------| ... |--|
378 If there's no overlap with the previous range, as in:
380 #3 - not overlapping and not contiguous
384 |--| |---| |------| ... |--|
391 #4 - R is the range with lowest offset
395 |--| |---| |------| ... |--|
400 ... we just push the new range to I.
402 All the 4 cases above need to consider that the new range may
403 also overlap several of the ranges that follow, or that R may be
404 contiguous with the following range, and merge. E.g.,
406 #5 - overlapping following ranges
409 |------------------------|
410 |--| |---| |------| ... |--|
419 |--| |---| |------| ... |--|
426 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
429 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- i
);
431 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
434 ULONGEST l
= min (bef
->offset
, offset
);
435 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
441 else if (offset
== bef
->offset
+ bef
->length
)
444 bef
->length
+= length
;
450 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
456 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
459 /* Check whether the ranges following the one we've just added or
460 touched can be folded in (#5 above). */
461 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
468 /* Get the range we just touched. */
469 t
= VEC_index (range_s
, value
->unavailable
, i
);
473 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
474 if (r
->offset
<= t
->offset
+ t
->length
)
478 l
= min (t
->offset
, r
->offset
);
479 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
488 /* If we couldn't merge this one, we won't be able to
489 merge following ones either, since the ranges are
490 always sorted by OFFSET. */
495 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
499 /* Find the first range in RANGES that overlaps the range defined by
500 OFFSET and LENGTH, starting at element POS in the RANGES vector,
501 Returns the index into RANGES where such overlapping range was
502 found, or -1 if none was found. */
505 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
506 int offset
, int length
)
511 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
512 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
519 value_available_contents_eq (const struct value
*val1
, int offset1
,
520 const struct value
*val2
, int offset2
,
523 int org_len
= length
;
524 int org_offset1
= offset1
;
525 int org_offset2
= offset2
;
526 int idx1
= 0, idx2
= 0;
529 /* This routine is used by printing routines, where we should
530 already have read the value. Note that we only know whether a
531 value chunk is available if we've tried to read it. */
532 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
534 /* The offset from either ORG_OFFSET1 or ORG_OFFSET2 where the
535 available contents we haven't compared yet start. */
544 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
546 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
549 /* The usual case is for both values to be completely available. */
550 if (idx1
== -1 && idx2
== -1)
551 return (memcmp (val1
->contents
+ org_offset1
+ prev_avail
,
552 val2
->contents
+ org_offset2
+ prev_avail
,
553 org_len
- prev_avail
) == 0);
554 /* The contents only match equal if the available set matches as
556 else if (idx1
== -1 || idx2
== -1)
559 gdb_assert (idx1
!= -1 && idx2
!= -1);
561 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
562 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
564 /* Get the unavailable windows intersected by the incoming
565 ranges. The first and last ranges that overlap the argument
566 range may be wider than said incoming arguments ranges. */
567 l1
= max (offset1
, r1
->offset
);
568 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
570 l2
= max (offset2
, r2
->offset
);
571 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
573 /* Make them relative to the respective start offsets, so we can
574 compare them for equality. */
581 /* Different availability, no match. */
582 if (l1
!= l2
|| h1
!= h2
)
585 /* Compare the _available_ contents. */
586 if (memcmp (val1
->contents
+ org_offset1
+ prev_avail
,
587 val2
->contents
+ org_offset2
+ prev_avail
,
588 l2
- prev_avail
) != 0)
600 /* Prototypes for local functions. */
602 static void show_values (char *, int);
604 static void show_convenience (char *, int);
607 /* The value-history records all the values printed
608 by print commands during this session. Each chunk
609 records 60 consecutive values. The first chunk on
610 the chain records the most recent values.
611 The total number of values is in value_history_count. */
613 #define VALUE_HISTORY_CHUNK 60
615 struct value_history_chunk
617 struct value_history_chunk
*next
;
618 struct value
*values
[VALUE_HISTORY_CHUNK
];
621 /* Chain of chunks now in use. */
623 static struct value_history_chunk
*value_history_chain
;
625 static int value_history_count
; /* Abs number of last entry stored. */
628 /* List of all value objects currently allocated
629 (except for those released by calls to release_value)
630 This is so they can be freed after each command. */
632 static struct value
*all_values
;
634 /* Allocate a lazy value for type TYPE. Its actual content is
635 "lazily" allocated too: the content field of the return value is
636 NULL; it will be allocated when it is fetched from the target. */
639 allocate_value_lazy (struct type
*type
)
643 /* Call check_typedef on our type to make sure that, if TYPE
644 is a TYPE_CODE_TYPEDEF, its length is set to the length
645 of the target type instead of zero. However, we do not
646 replace the typedef type by the target type, because we want
647 to keep the typedef in order to be able to set the VAL's type
648 description correctly. */
649 check_typedef (type
);
651 val
= (struct value
*) xzalloc (sizeof (struct value
));
652 val
->contents
= NULL
;
653 val
->next
= all_values
;
656 val
->enclosing_type
= type
;
657 VALUE_LVAL (val
) = not_lval
;
658 val
->location
.address
= 0;
659 VALUE_FRAME_ID (val
) = null_frame_id
;
663 VALUE_REGNUM (val
) = -1;
665 val
->optimized_out
= 0;
666 val
->embedded_offset
= 0;
667 val
->pointed_to_offset
= 0;
669 val
->initialized
= 1; /* Default to initialized. */
671 /* Values start out on the all_values chain. */
672 val
->reference_count
= 1;
677 /* Allocate the contents of VAL if it has not been allocated yet. */
680 allocate_value_contents (struct value
*val
)
683 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
686 /* Allocate a value and its contents for type TYPE. */
689 allocate_value (struct type
*type
)
691 struct value
*val
= allocate_value_lazy (type
);
693 allocate_value_contents (val
);
698 /* Allocate a value that has the correct length
699 for COUNT repetitions of type TYPE. */
702 allocate_repeat_value (struct type
*type
, int count
)
704 int low_bound
= current_language
->string_lower_bound
; /* ??? */
705 /* FIXME-type-allocation: need a way to free this type when we are
707 struct type
*array_type
708 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
710 return allocate_value (array_type
);
714 allocate_computed_value (struct type
*type
,
715 struct lval_funcs
*funcs
,
718 struct value
*v
= allocate_value_lazy (type
);
720 VALUE_LVAL (v
) = lval_computed
;
721 v
->location
.computed
.funcs
= funcs
;
722 v
->location
.computed
.closure
= closure
;
727 /* Accessor methods. */
730 value_next (struct value
*value
)
736 value_type (const struct value
*value
)
741 deprecated_set_value_type (struct value
*value
, struct type
*type
)
747 value_offset (const struct value
*value
)
749 return value
->offset
;
752 set_value_offset (struct value
*value
, int offset
)
754 value
->offset
= offset
;
758 value_bitpos (const struct value
*value
)
760 return value
->bitpos
;
763 set_value_bitpos (struct value
*value
, int bit
)
769 value_bitsize (const struct value
*value
)
771 return value
->bitsize
;
774 set_value_bitsize (struct value
*value
, int bit
)
776 value
->bitsize
= bit
;
780 value_parent (struct value
*value
)
782 return value
->parent
;
786 value_contents_raw (struct value
*value
)
788 allocate_value_contents (value
);
789 return value
->contents
+ value
->embedded_offset
;
793 value_contents_all_raw (struct value
*value
)
795 allocate_value_contents (value
);
796 return value
->contents
;
800 value_enclosing_type (struct value
*value
)
802 return value
->enclosing_type
;
806 require_not_optimized_out (const struct value
*value
)
808 if (value
->optimized_out
)
809 error (_("value has been optimized out"));
813 require_available (const struct value
*value
)
815 if (!VEC_empty (range_s
, value
->unavailable
))
816 error (_("value is not available"));
820 value_contents_for_printing (struct value
*value
)
823 value_fetch_lazy (value
);
824 return value
->contents
;
828 value_contents_for_printing_const (const struct value
*value
)
830 gdb_assert (!value
->lazy
);
831 return value
->contents
;
835 value_contents_all (struct value
*value
)
837 const gdb_byte
*result
= value_contents_for_printing (value
);
838 require_not_optimized_out (value
);
839 require_available (value
);
843 /* Copy LENGTH bytes of SRC value's contents starting at SRC_OFFSET,
844 into DST value's contents, starting at DST_OFFSET. If unavailable
845 contents are being copied from SRC, the corresponding DST contents
846 are marked unavailable accordingly. Neither DST nor SRC may be
850 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
851 struct value
*src
, int src_offset
, int length
)
856 /* A lazy DST would make that this copy operation useless, since as
857 soon as DST's contents were un-lazied (by a later value_contents
858 call, say), the contents would be overwritten. A lazy SRC would
859 mean we'd be copying garbage. */
860 gdb_assert (!dst
->lazy
&& !src
->lazy
);
863 memcpy (value_contents_all_raw (dst
) + dst_offset
,
864 value_contents_all_raw (src
) + src_offset
,
867 /* Copy the meta-data, adjusted. */
868 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
872 l
= max (r
->offset
, src_offset
);
873 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
876 mark_value_bytes_unavailable (dst
,
877 dst_offset
+ (l
- src_offset
),
882 /* Copy LENGTH bytes of SRC value's contents starting at SRC_OFFSET
883 byte, into DST value's contents, starting at DST_OFFSET. If
884 unavailable contents are being copied from SRC, the corresponding
885 DST contents are marked unavailable accordingly. DST must not be
886 lazy. If SRC is lazy, it will be fetched now. If SRC is not valid
887 (is optimized out), an error is thrown. */
890 value_contents_copy (struct value
*dst
, int dst_offset
,
891 struct value
*src
, int src_offset
, int length
)
893 require_not_optimized_out (src
);
896 value_fetch_lazy (src
);
898 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
902 value_lazy (struct value
*value
)
908 set_value_lazy (struct value
*value
, int val
)
914 value_stack (struct value
*value
)
920 set_value_stack (struct value
*value
, int val
)
926 value_contents (struct value
*value
)
928 const gdb_byte
*result
= value_contents_writeable (value
);
929 require_not_optimized_out (value
);
930 require_available (value
);
935 value_contents_writeable (struct value
*value
)
938 value_fetch_lazy (value
);
939 return value_contents_raw (value
);
942 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
943 this function is different from value_equal; in C the operator ==
944 can return 0 even if the two values being compared are equal. */
947 value_contents_equal (struct value
*val1
, struct value
*val2
)
953 type1
= check_typedef (value_type (val1
));
954 type2
= check_typedef (value_type (val2
));
955 len
= TYPE_LENGTH (type1
);
956 if (len
!= TYPE_LENGTH (type2
))
959 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
963 value_optimized_out (struct value
*value
)
965 return value
->optimized_out
;
969 set_value_optimized_out (struct value
*value
, int val
)
971 value
->optimized_out
= val
;
975 value_entirely_optimized_out (const struct value
*value
)
977 if (!value
->optimized_out
)
979 if (value
->lval
!= lval_computed
980 || !value
->location
.computed
.funcs
->check_any_valid
)
982 return !value
->location
.computed
.funcs
->check_any_valid (value
);
986 value_bits_valid (const struct value
*value
, int offset
, int length
)
988 if (value
== NULL
|| !value
->optimized_out
)
990 if (value
->lval
!= lval_computed
991 || !value
->location
.computed
.funcs
->check_validity
)
993 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
998 value_bits_synthetic_pointer (const struct value
*value
,
999 int offset
, int length
)
1001 if (value
== NULL
|| value
->lval
!= lval_computed
1002 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1004 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1010 value_embedded_offset (struct value
*value
)
1012 return value
->embedded_offset
;
1016 set_value_embedded_offset (struct value
*value
, int val
)
1018 value
->embedded_offset
= val
;
1022 value_pointed_to_offset (struct value
*value
)
1024 return value
->pointed_to_offset
;
1028 set_value_pointed_to_offset (struct value
*value
, int val
)
1030 value
->pointed_to_offset
= val
;
1034 value_computed_funcs (struct value
*v
)
1036 gdb_assert (VALUE_LVAL (v
) == lval_computed
);
1038 return v
->location
.computed
.funcs
;
1042 value_computed_closure (const struct value
*v
)
1044 gdb_assert (v
->lval
== lval_computed
);
1046 return v
->location
.computed
.closure
;
1050 deprecated_value_lval_hack (struct value
*value
)
1052 return &value
->lval
;
1056 value_address (const struct value
*value
)
1058 if (value
->lval
== lval_internalvar
1059 || value
->lval
== lval_internalvar_component
)
1061 return value
->location
.address
+ value
->offset
;
1065 value_raw_address (struct value
*value
)
1067 if (value
->lval
== lval_internalvar
1068 || value
->lval
== lval_internalvar_component
)
1070 return value
->location
.address
;
1074 set_value_address (struct value
*value
, CORE_ADDR addr
)
1076 gdb_assert (value
->lval
!= lval_internalvar
1077 && value
->lval
!= lval_internalvar_component
);
1078 value
->location
.address
= addr
;
1081 struct internalvar
**
1082 deprecated_value_internalvar_hack (struct value
*value
)
1084 return &value
->location
.internalvar
;
1088 deprecated_value_frame_id_hack (struct value
*value
)
1090 return &value
->frame_id
;
1094 deprecated_value_regnum_hack (struct value
*value
)
1096 return &value
->regnum
;
1100 deprecated_value_modifiable (struct value
*value
)
1102 return value
->modifiable
;
1105 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1107 value
->modifiable
= modifiable
;
1110 /* Return a mark in the value chain. All values allocated after the
1111 mark is obtained (except for those released) are subject to being freed
1112 if a subsequent value_free_to_mark is passed the mark. */
1119 /* Take a reference to VAL. VAL will not be deallocated until all
1120 references are released. */
1123 value_incref (struct value
*val
)
1125 val
->reference_count
++;
1128 /* Release a reference to VAL, which was acquired with value_incref.
1129 This function is also called to deallocate values from the value
1133 value_free (struct value
*val
)
1137 gdb_assert (val
->reference_count
> 0);
1138 val
->reference_count
--;
1139 if (val
->reference_count
> 0)
1142 /* If there's an associated parent value, drop our reference to
1144 if (val
->parent
!= NULL
)
1145 value_free (val
->parent
);
1147 if (VALUE_LVAL (val
) == lval_computed
)
1149 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1151 if (funcs
->free_closure
)
1152 funcs
->free_closure (val
);
1155 xfree (val
->contents
);
1156 VEC_free (range_s
, val
->unavailable
);
1161 /* Free all values allocated since MARK was obtained by value_mark
1162 (except for those released). */
1164 value_free_to_mark (struct value
*mark
)
1169 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1177 /* Free all the values that have been allocated (except for those released).
1178 Call after each command, successful or not.
1179 In practice this is called before each command, which is sufficient. */
1182 free_all_values (void)
1187 for (val
= all_values
; val
; val
= next
)
1196 /* Frees all the elements in a chain of values. */
1199 free_value_chain (struct value
*v
)
1205 next
= value_next (v
);
1210 /* Remove VAL from the chain all_values
1211 so it will not be freed automatically. */
1214 release_value (struct value
*val
)
1218 if (all_values
== val
)
1220 all_values
= val
->next
;
1225 for (v
= all_values
; v
; v
= v
->next
)
1229 v
->next
= val
->next
;
1236 /* Release all values up to mark */
1238 value_release_to_mark (struct value
*mark
)
1243 for (val
= next
= all_values
; next
; next
= next
->next
)
1244 if (next
->next
== mark
)
1246 all_values
= next
->next
;
1254 /* Return a copy of the value ARG.
1255 It contains the same contents, for same memory address,
1256 but it's a different block of storage. */
1259 value_copy (struct value
*arg
)
1261 struct type
*encl_type
= value_enclosing_type (arg
);
1264 if (value_lazy (arg
))
1265 val
= allocate_value_lazy (encl_type
);
1267 val
= allocate_value (encl_type
);
1268 val
->type
= arg
->type
;
1269 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1270 val
->location
= arg
->location
;
1271 val
->offset
= arg
->offset
;
1272 val
->bitpos
= arg
->bitpos
;
1273 val
->bitsize
= arg
->bitsize
;
1274 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1275 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1276 val
->lazy
= arg
->lazy
;
1277 val
->optimized_out
= arg
->optimized_out
;
1278 val
->embedded_offset
= value_embedded_offset (arg
);
1279 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1280 val
->modifiable
= arg
->modifiable
;
1281 if (!value_lazy (val
))
1283 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1284 TYPE_LENGTH (value_enclosing_type (arg
)));
1287 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1288 val
->parent
= arg
->parent
;
1290 value_incref (val
->parent
);
1291 if (VALUE_LVAL (val
) == lval_computed
)
1293 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1295 if (funcs
->copy_closure
)
1296 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1301 /* Return a version of ARG that is non-lvalue. */
1304 value_non_lval (struct value
*arg
)
1306 if (VALUE_LVAL (arg
) != not_lval
)
1308 struct type
*enc_type
= value_enclosing_type (arg
);
1309 struct value
*val
= allocate_value (enc_type
);
1311 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1312 TYPE_LENGTH (enc_type
));
1313 val
->type
= arg
->type
;
1314 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1315 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1322 set_value_component_location (struct value
*component
,
1323 const struct value
*whole
)
1325 if (whole
->lval
== lval_internalvar
)
1326 VALUE_LVAL (component
) = lval_internalvar_component
;
1328 VALUE_LVAL (component
) = whole
->lval
;
1330 component
->location
= whole
->location
;
1331 if (whole
->lval
== lval_computed
)
1333 struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1335 if (funcs
->copy_closure
)
1336 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1341 /* Access to the value history. */
1343 /* Record a new value in the value history.
1344 Returns the absolute history index of the entry.
1345 Result of -1 indicates the value was not saved; otherwise it is the
1346 value history index of this new item. */
1349 record_latest_value (struct value
*val
)
1353 /* We don't want this value to have anything to do with the inferior anymore.
1354 In particular, "set $1 = 50" should not affect the variable from which
1355 the value was taken, and fast watchpoints should be able to assume that
1356 a value on the value history never changes. */
1357 if (value_lazy (val
))
1358 value_fetch_lazy (val
);
1359 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1360 from. This is a bit dubious, because then *&$1 does not just return $1
1361 but the current contents of that location. c'est la vie... */
1362 val
->modifiable
= 0;
1363 release_value (val
);
1365 /* Here we treat value_history_count as origin-zero
1366 and applying to the value being stored now. */
1368 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1371 struct value_history_chunk
*new
1372 = (struct value_history_chunk
*)
1374 xmalloc (sizeof (struct value_history_chunk
));
1375 memset (new->values
, 0, sizeof new->values
);
1376 new->next
= value_history_chain
;
1377 value_history_chain
= new;
1380 value_history_chain
->values
[i
] = val
;
1382 /* Now we regard value_history_count as origin-one
1383 and applying to the value just stored. */
1385 return ++value_history_count
;
1388 /* Return a copy of the value in the history with sequence number NUM. */
1391 access_value_history (int num
)
1393 struct value_history_chunk
*chunk
;
1398 absnum
+= value_history_count
;
1403 error (_("The history is empty."));
1405 error (_("There is only one value in the history."));
1407 error (_("History does not go back to $$%d."), -num
);
1409 if (absnum
> value_history_count
)
1410 error (_("History has not yet reached $%d."), absnum
);
1414 /* Now absnum is always absolute and origin zero. */
1416 chunk
= value_history_chain
;
1417 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1418 - absnum
/ VALUE_HISTORY_CHUNK
;
1420 chunk
= chunk
->next
;
1422 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1426 show_values (char *num_exp
, int from_tty
)
1434 /* "show values +" should print from the stored position.
1435 "show values <exp>" should print around value number <exp>. */
1436 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1437 num
= parse_and_eval_long (num_exp
) - 5;
1441 /* "show values" means print the last 10 values. */
1442 num
= value_history_count
- 9;
1448 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1450 struct value_print_options opts
;
1452 val
= access_value_history (i
);
1453 printf_filtered (("$%d = "), i
);
1454 get_user_print_options (&opts
);
1455 value_print (val
, gdb_stdout
, &opts
);
1456 printf_filtered (("\n"));
1459 /* The next "show values +" should start after what we just printed. */
1462 /* Hitting just return after this command should do the same thing as
1463 "show values +". If num_exp is null, this is unnecessary, since
1464 "show values +" is not useful after "show values". */
1465 if (from_tty
&& num_exp
)
1472 /* Internal variables. These are variables within the debugger
1473 that hold values assigned by debugger commands.
1474 The user refers to them with a '$' prefix
1475 that does not appear in the variable names stored internally. */
1479 struct internalvar
*next
;
1482 /* We support various different kinds of content of an internal variable.
1483 enum internalvar_kind specifies the kind, and union internalvar_data
1484 provides the data associated with this particular kind. */
1486 enum internalvar_kind
1488 /* The internal variable is empty. */
1491 /* The value of the internal variable is provided directly as
1492 a GDB value object. */
1495 /* A fresh value is computed via a call-back routine on every
1496 access to the internal variable. */
1497 INTERNALVAR_MAKE_VALUE
,
1499 /* The internal variable holds a GDB internal convenience function. */
1500 INTERNALVAR_FUNCTION
,
1502 /* The variable holds an integer value. */
1503 INTERNALVAR_INTEGER
,
1505 /* The variable holds a GDB-provided string. */
1510 union internalvar_data
1512 /* A value object used with INTERNALVAR_VALUE. */
1513 struct value
*value
;
1515 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1516 internalvar_make_value make_value
;
1518 /* The internal function used with INTERNALVAR_FUNCTION. */
1521 struct internal_function
*function
;
1522 /* True if this is the canonical name for the function. */
1526 /* An integer value used with INTERNALVAR_INTEGER. */
1529 /* If type is non-NULL, it will be used as the type to generate
1530 a value for this internal variable. If type is NULL, a default
1531 integer type for the architecture is used. */
1536 /* A string value used with INTERNALVAR_STRING. */
1541 static struct internalvar
*internalvars
;
1543 /* If the variable does not already exist create it and give it the
1544 value given. If no value is given then the default is zero. */
1546 init_if_undefined_command (char* args
, int from_tty
)
1548 struct internalvar
* intvar
;
1550 /* Parse the expression - this is taken from set_command(). */
1551 struct expression
*expr
= parse_expression (args
);
1552 register struct cleanup
*old_chain
=
1553 make_cleanup (free_current_contents
, &expr
);
1555 /* Validate the expression.
1556 Was the expression an assignment?
1557 Or even an expression at all? */
1558 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1559 error (_("Init-if-undefined requires an assignment expression."));
1561 /* Extract the variable from the parsed expression.
1562 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1563 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1564 error (_("The first parameter to init-if-undefined "
1565 "should be a GDB variable."));
1566 intvar
= expr
->elts
[2].internalvar
;
1568 /* Only evaluate the expression if the lvalue is void.
1569 This may still fail if the expresssion is invalid. */
1570 if (intvar
->kind
== INTERNALVAR_VOID
)
1571 evaluate_expression (expr
);
1573 do_cleanups (old_chain
);
1577 /* Look up an internal variable with name NAME. NAME should not
1578 normally include a dollar sign.
1580 If the specified internal variable does not exist,
1581 the return value is NULL. */
1583 struct internalvar
*
1584 lookup_only_internalvar (const char *name
)
1586 struct internalvar
*var
;
1588 for (var
= internalvars
; var
; var
= var
->next
)
1589 if (strcmp (var
->name
, name
) == 0)
1596 /* Create an internal variable with name NAME and with a void value.
1597 NAME should not normally include a dollar sign. */
1599 struct internalvar
*
1600 create_internalvar (const char *name
)
1602 struct internalvar
*var
;
1604 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1605 var
->name
= concat (name
, (char *)NULL
);
1606 var
->kind
= INTERNALVAR_VOID
;
1607 var
->next
= internalvars
;
1612 /* Create an internal variable with name NAME and register FUN as the
1613 function that value_of_internalvar uses to create a value whenever
1614 this variable is referenced. NAME should not normally include a
1617 struct internalvar
*
1618 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1620 struct internalvar
*var
= create_internalvar (name
);
1622 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1623 var
->u
.make_value
= fun
;
1627 /* Look up an internal variable with name NAME. NAME should not
1628 normally include a dollar sign.
1630 If the specified internal variable does not exist,
1631 one is created, with a void value. */
1633 struct internalvar
*
1634 lookup_internalvar (const char *name
)
1636 struct internalvar
*var
;
1638 var
= lookup_only_internalvar (name
);
1642 return create_internalvar (name
);
1645 /* Return current value of internal variable VAR. For variables that
1646 are not inherently typed, use a value type appropriate for GDBARCH. */
1649 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1652 struct trace_state_variable
*tsv
;
1654 /* If there is a trace state variable of the same name, assume that
1655 is what we really want to see. */
1656 tsv
= find_trace_state_variable (var
->name
);
1659 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1661 if (tsv
->value_known
)
1662 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1665 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1671 case INTERNALVAR_VOID
:
1672 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1675 case INTERNALVAR_FUNCTION
:
1676 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1679 case INTERNALVAR_INTEGER
:
1680 if (!var
->u
.integer
.type
)
1681 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1682 var
->u
.integer
.val
);
1684 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1687 case INTERNALVAR_STRING
:
1688 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1689 builtin_type (gdbarch
)->builtin_char
);
1692 case INTERNALVAR_VALUE
:
1693 val
= value_copy (var
->u
.value
);
1694 if (value_lazy (val
))
1695 value_fetch_lazy (val
);
1698 case INTERNALVAR_MAKE_VALUE
:
1699 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1703 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1706 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1707 on this value go back to affect the original internal variable.
1709 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1710 no underlying modifyable state in the internal variable.
1712 Likewise, if the variable's value is a computed lvalue, we want
1713 references to it to produce another computed lvalue, where
1714 references and assignments actually operate through the
1715 computed value's functions.
1717 This means that internal variables with computed values
1718 behave a little differently from other internal variables:
1719 assignments to them don't just replace the previous value
1720 altogether. At the moment, this seems like the behavior we
1723 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1724 && val
->lval
!= lval_computed
)
1726 VALUE_LVAL (val
) = lval_internalvar
;
1727 VALUE_INTERNALVAR (val
) = var
;
1734 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1736 if (var
->kind
== INTERNALVAR_INTEGER
)
1738 *result
= var
->u
.integer
.val
;
1742 if (var
->kind
== INTERNALVAR_VALUE
)
1744 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1746 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1748 *result
= value_as_long (var
->u
.value
);
1757 get_internalvar_function (struct internalvar
*var
,
1758 struct internal_function
**result
)
1762 case INTERNALVAR_FUNCTION
:
1763 *result
= var
->u
.fn
.function
;
1772 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1773 int bitsize
, struct value
*newval
)
1779 case INTERNALVAR_VALUE
:
1780 addr
= value_contents_writeable (var
->u
.value
);
1783 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1784 value_as_long (newval
), bitpos
, bitsize
);
1786 memcpy (addr
+ offset
, value_contents (newval
),
1787 TYPE_LENGTH (value_type (newval
)));
1791 /* We can never get a component of any other kind. */
1792 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1797 set_internalvar (struct internalvar
*var
, struct value
*val
)
1799 enum internalvar_kind new_kind
;
1800 union internalvar_data new_data
= { 0 };
1802 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1803 error (_("Cannot overwrite convenience function %s"), var
->name
);
1805 /* Prepare new contents. */
1806 switch (TYPE_CODE (check_typedef (value_type (val
))))
1808 case TYPE_CODE_VOID
:
1809 new_kind
= INTERNALVAR_VOID
;
1812 case TYPE_CODE_INTERNAL_FUNCTION
:
1813 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1814 new_kind
= INTERNALVAR_FUNCTION
;
1815 get_internalvar_function (VALUE_INTERNALVAR (val
),
1816 &new_data
.fn
.function
);
1817 /* Copies created here are never canonical. */
1821 new_kind
= INTERNALVAR_VALUE
;
1822 new_data
.value
= value_copy (val
);
1823 new_data
.value
->modifiable
= 1;
1825 /* Force the value to be fetched from the target now, to avoid problems
1826 later when this internalvar is referenced and the target is gone or
1828 if (value_lazy (new_data
.value
))
1829 value_fetch_lazy (new_data
.value
);
1831 /* Release the value from the value chain to prevent it from being
1832 deleted by free_all_values. From here on this function should not
1833 call error () until new_data is installed into the var->u to avoid
1835 release_value (new_data
.value
);
1839 /* Clean up old contents. */
1840 clear_internalvar (var
);
1843 var
->kind
= new_kind
;
1845 /* End code which must not call error(). */
1849 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1851 /* Clean up old contents. */
1852 clear_internalvar (var
);
1854 var
->kind
= INTERNALVAR_INTEGER
;
1855 var
->u
.integer
.type
= NULL
;
1856 var
->u
.integer
.val
= l
;
1860 set_internalvar_string (struct internalvar
*var
, const char *string
)
1862 /* Clean up old contents. */
1863 clear_internalvar (var
);
1865 var
->kind
= INTERNALVAR_STRING
;
1866 var
->u
.string
= xstrdup (string
);
1870 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1872 /* Clean up old contents. */
1873 clear_internalvar (var
);
1875 var
->kind
= INTERNALVAR_FUNCTION
;
1876 var
->u
.fn
.function
= f
;
1877 var
->u
.fn
.canonical
= 1;
1878 /* Variables installed here are always the canonical version. */
1882 clear_internalvar (struct internalvar
*var
)
1884 /* Clean up old contents. */
1887 case INTERNALVAR_VALUE
:
1888 value_free (var
->u
.value
);
1891 case INTERNALVAR_STRING
:
1892 xfree (var
->u
.string
);
1899 /* Reset to void kind. */
1900 var
->kind
= INTERNALVAR_VOID
;
1904 internalvar_name (struct internalvar
*var
)
1909 static struct internal_function
*
1910 create_internal_function (const char *name
,
1911 internal_function_fn handler
, void *cookie
)
1913 struct internal_function
*ifn
= XNEW (struct internal_function
);
1915 ifn
->name
= xstrdup (name
);
1916 ifn
->handler
= handler
;
1917 ifn
->cookie
= cookie
;
1922 value_internal_function_name (struct value
*val
)
1924 struct internal_function
*ifn
;
1927 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1928 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
1929 gdb_assert (result
);
1935 call_internal_function (struct gdbarch
*gdbarch
,
1936 const struct language_defn
*language
,
1937 struct value
*func
, int argc
, struct value
**argv
)
1939 struct internal_function
*ifn
;
1942 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
1943 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
1944 gdb_assert (result
);
1946 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
1949 /* The 'function' command. This does nothing -- it is just a
1950 placeholder to let "help function NAME" work. This is also used as
1951 the implementation of the sub-command that is created when
1952 registering an internal function. */
1954 function_command (char *command
, int from_tty
)
1959 /* Clean up if an internal function's command is destroyed. */
1961 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
1967 /* Add a new internal function. NAME is the name of the function; DOC
1968 is a documentation string describing the function. HANDLER is
1969 called when the function is invoked. COOKIE is an arbitrary
1970 pointer which is passed to HANDLER and is intended for "user
1973 add_internal_function (const char *name
, const char *doc
,
1974 internal_function_fn handler
, void *cookie
)
1976 struct cmd_list_element
*cmd
;
1977 struct internal_function
*ifn
;
1978 struct internalvar
*var
= lookup_internalvar (name
);
1980 ifn
= create_internal_function (name
, handler
, cookie
);
1981 set_internalvar_function (var
, ifn
);
1983 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
1985 cmd
->destroyer
= function_destroyer
;
1988 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
1989 prevent cycles / duplicates. */
1992 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
1993 htab_t copied_types
)
1995 if (TYPE_OBJFILE (value
->type
) == objfile
)
1996 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
1998 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
1999 value
->enclosing_type
= copy_type_recursive (objfile
,
2000 value
->enclosing_type
,
2004 /* Likewise for internal variable VAR. */
2007 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2008 htab_t copied_types
)
2012 case INTERNALVAR_INTEGER
:
2013 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2015 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2018 case INTERNALVAR_VALUE
:
2019 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2024 /* Update the internal variables and value history when OBJFILE is
2025 discarded; we must copy the types out of the objfile. New global types
2026 will be created for every convenience variable which currently points to
2027 this objfile's types, and the convenience variables will be adjusted to
2028 use the new global types. */
2031 preserve_values (struct objfile
*objfile
)
2033 htab_t copied_types
;
2034 struct value_history_chunk
*cur
;
2035 struct internalvar
*var
;
2038 /* Create the hash table. We allocate on the objfile's obstack, since
2039 it is soon to be deleted. */
2040 copied_types
= create_copied_types_hash (objfile
);
2042 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2043 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2045 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2047 for (var
= internalvars
; var
; var
= var
->next
)
2048 preserve_one_internalvar (var
, objfile
, copied_types
);
2050 preserve_python_values (objfile
, copied_types
);
2052 htab_delete (copied_types
);
2056 show_convenience (char *ignore
, int from_tty
)
2058 struct gdbarch
*gdbarch
= get_current_arch ();
2059 struct internalvar
*var
;
2061 struct value_print_options opts
;
2063 get_user_print_options (&opts
);
2064 for (var
= internalvars
; var
; var
= var
->next
)
2070 printf_filtered (("$%s = "), var
->name
);
2071 value_print (value_of_internalvar (gdbarch
, var
), gdb_stdout
,
2073 printf_filtered (("\n"));
2076 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2077 "Convenience variables have "
2078 "names starting with \"$\";\n"
2079 "use \"set\" as in \"set "
2080 "$foo = 5\" to define them.\n"));
2083 /* Extract a value as a C number (either long or double).
2084 Knows how to convert fixed values to double, or
2085 floating values to long.
2086 Does not deallocate the value. */
2089 value_as_long (struct value
*val
)
2091 /* This coerces arrays and functions, which is necessary (e.g.
2092 in disassemble_command). It also dereferences references, which
2093 I suspect is the most logical thing to do. */
2094 val
= coerce_array (val
);
2095 return unpack_long (value_type (val
), value_contents (val
));
2099 value_as_double (struct value
*val
)
2104 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2106 error (_("Invalid floating value found in program."));
2110 /* Extract a value as a C pointer. Does not deallocate the value.
2111 Note that val's type may not actually be a pointer; value_as_long
2112 handles all the cases. */
2114 value_as_address (struct value
*val
)
2116 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2118 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2119 whether we want this to be true eventually. */
2121 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2122 non-address (e.g. argument to "signal", "info break", etc.), or
2123 for pointers to char, in which the low bits *are* significant. */
2124 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2127 /* There are several targets (IA-64, PowerPC, and others) which
2128 don't represent pointers to functions as simply the address of
2129 the function's entry point. For example, on the IA-64, a
2130 function pointer points to a two-word descriptor, generated by
2131 the linker, which contains the function's entry point, and the
2132 value the IA-64 "global pointer" register should have --- to
2133 support position-independent code. The linker generates
2134 descriptors only for those functions whose addresses are taken.
2136 On such targets, it's difficult for GDB to convert an arbitrary
2137 function address into a function pointer; it has to either find
2138 an existing descriptor for that function, or call malloc and
2139 build its own. On some targets, it is impossible for GDB to
2140 build a descriptor at all: the descriptor must contain a jump
2141 instruction; data memory cannot be executed; and code memory
2144 Upon entry to this function, if VAL is a value of type `function'
2145 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2146 value_address (val) is the address of the function. This is what
2147 you'll get if you evaluate an expression like `main'. The call
2148 to COERCE_ARRAY below actually does all the usual unary
2149 conversions, which includes converting values of type `function'
2150 to `pointer to function'. This is the challenging conversion
2151 discussed above. Then, `unpack_long' will convert that pointer
2152 back into an address.
2154 So, suppose the user types `disassemble foo' on an architecture
2155 with a strange function pointer representation, on which GDB
2156 cannot build its own descriptors, and suppose further that `foo'
2157 has no linker-built descriptor. The address->pointer conversion
2158 will signal an error and prevent the command from running, even
2159 though the next step would have been to convert the pointer
2160 directly back into the same address.
2162 The following shortcut avoids this whole mess. If VAL is a
2163 function, just return its address directly. */
2164 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2165 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2166 return value_address (val
);
2168 val
= coerce_array (val
);
2170 /* Some architectures (e.g. Harvard), map instruction and data
2171 addresses onto a single large unified address space. For
2172 instance: An architecture may consider a large integer in the
2173 range 0x10000000 .. 0x1000ffff to already represent a data
2174 addresses (hence not need a pointer to address conversion) while
2175 a small integer would still need to be converted integer to
2176 pointer to address. Just assume such architectures handle all
2177 integer conversions in a single function. */
2181 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2182 must admonish GDB hackers to make sure its behavior matches the
2183 compiler's, whenever possible.
2185 In general, I think GDB should evaluate expressions the same way
2186 the compiler does. When the user copies an expression out of
2187 their source code and hands it to a `print' command, they should
2188 get the same value the compiler would have computed. Any
2189 deviation from this rule can cause major confusion and annoyance,
2190 and needs to be justified carefully. In other words, GDB doesn't
2191 really have the freedom to do these conversions in clever and
2194 AndrewC pointed out that users aren't complaining about how GDB
2195 casts integers to pointers; they are complaining that they can't
2196 take an address from a disassembly listing and give it to `x/i'.
2197 This is certainly important.
2199 Adding an architecture method like integer_to_address() certainly
2200 makes it possible for GDB to "get it right" in all circumstances
2201 --- the target has complete control over how things get done, so
2202 people can Do The Right Thing for their target without breaking
2203 anyone else. The standard doesn't specify how integers get
2204 converted to pointers; usually, the ABI doesn't either, but
2205 ABI-specific code is a more reasonable place to handle it. */
2207 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2208 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2209 && gdbarch_integer_to_address_p (gdbarch
))
2210 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2211 value_contents (val
));
2213 return unpack_long (value_type (val
), value_contents (val
));
2217 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2218 as a long, or as a double, assuming the raw data is described
2219 by type TYPE. Knows how to convert different sizes of values
2220 and can convert between fixed and floating point. We don't assume
2221 any alignment for the raw data. Return value is in host byte order.
2223 If you want functions and arrays to be coerced to pointers, and
2224 references to be dereferenced, call value_as_long() instead.
2226 C++: It is assumed that the front-end has taken care of
2227 all matters concerning pointers to members. A pointer
2228 to member which reaches here is considered to be equivalent
2229 to an INT (or some size). After all, it is only an offset. */
2232 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2234 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2235 enum type_code code
= TYPE_CODE (type
);
2236 int len
= TYPE_LENGTH (type
);
2237 int nosign
= TYPE_UNSIGNED (type
);
2241 case TYPE_CODE_TYPEDEF
:
2242 return unpack_long (check_typedef (type
), valaddr
);
2243 case TYPE_CODE_ENUM
:
2244 case TYPE_CODE_FLAGS
:
2245 case TYPE_CODE_BOOL
:
2247 case TYPE_CODE_CHAR
:
2248 case TYPE_CODE_RANGE
:
2249 case TYPE_CODE_MEMBERPTR
:
2251 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2253 return extract_signed_integer (valaddr
, len
, byte_order
);
2256 return extract_typed_floating (valaddr
, type
);
2258 case TYPE_CODE_DECFLOAT
:
2259 /* libdecnumber has a function to convert from decimal to integer, but
2260 it doesn't work when the decimal number has a fractional part. */
2261 return decimal_to_doublest (valaddr
, len
, byte_order
);
2265 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2266 whether we want this to be true eventually. */
2267 return extract_typed_address (valaddr
, type
);
2270 error (_("Value can't be converted to integer."));
2272 return 0; /* Placate lint. */
2275 /* Return a double value from the specified type and address.
2276 INVP points to an int which is set to 0 for valid value,
2277 1 for invalid value (bad float format). In either case,
2278 the returned double is OK to use. Argument is in target
2279 format, result is in host format. */
2282 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2284 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2285 enum type_code code
;
2289 *invp
= 0; /* Assume valid. */
2290 CHECK_TYPEDEF (type
);
2291 code
= TYPE_CODE (type
);
2292 len
= TYPE_LENGTH (type
);
2293 nosign
= TYPE_UNSIGNED (type
);
2294 if (code
== TYPE_CODE_FLT
)
2296 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2297 floating-point value was valid (using the macro
2298 INVALID_FLOAT). That test/macro have been removed.
2300 It turns out that only the VAX defined this macro and then
2301 only in a non-portable way. Fixing the portability problem
2302 wouldn't help since the VAX floating-point code is also badly
2303 bit-rotten. The target needs to add definitions for the
2304 methods gdbarch_float_format and gdbarch_double_format - these
2305 exactly describe the target floating-point format. The
2306 problem here is that the corresponding floatformat_vax_f and
2307 floatformat_vax_d values these methods should be set to are
2308 also not defined either. Oops!
2310 Hopefully someone will add both the missing floatformat
2311 definitions and the new cases for floatformat_is_valid (). */
2313 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2319 return extract_typed_floating (valaddr
, type
);
2321 else if (code
== TYPE_CODE_DECFLOAT
)
2322 return decimal_to_doublest (valaddr
, len
, byte_order
);
2325 /* Unsigned -- be sure we compensate for signed LONGEST. */
2326 return (ULONGEST
) unpack_long (type
, valaddr
);
2330 /* Signed -- we are OK with unpack_long. */
2331 return unpack_long (type
, valaddr
);
2335 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2336 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2337 We don't assume any alignment for the raw data. Return value is in
2340 If you want functions and arrays to be coerced to pointers, and
2341 references to be dereferenced, call value_as_address() instead.
2343 C++: It is assumed that the front-end has taken care of
2344 all matters concerning pointers to members. A pointer
2345 to member which reaches here is considered to be equivalent
2346 to an INT (or some size). After all, it is only an offset. */
2349 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2351 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2352 whether we want this to be true eventually. */
2353 return unpack_long (type
, valaddr
);
2357 /* Get the value of the FIELDNO'th field (which must be static) of
2358 TYPE. Return NULL if the field doesn't exist or has been
2362 value_static_field (struct type
*type
, int fieldno
)
2364 struct value
*retval
;
2366 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2368 case FIELD_LOC_KIND_PHYSADDR
:
2369 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2370 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2372 case FIELD_LOC_KIND_PHYSNAME
:
2374 char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2375 /* TYPE_FIELD_NAME (type, fieldno); */
2376 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2380 /* With some compilers, e.g. HP aCC, static data members are
2381 reported as non-debuggable symbols. */
2382 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2389 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2390 SYMBOL_VALUE_ADDRESS (msym
));
2394 retval
= value_of_variable (sym
, NULL
);
2398 gdb_assert_not_reached ("unexpected field location kind");
2404 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2405 You have to be careful here, since the size of the data area for the value
2406 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2407 than the old enclosing type, you have to allocate more space for the
2411 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2413 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2415 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2417 val
->enclosing_type
= new_encl_type
;
2420 /* Given a value ARG1 (offset by OFFSET bytes)
2421 of a struct or union type ARG_TYPE,
2422 extract and return the value of one of its (non-static) fields.
2423 FIELDNO says which field. */
2426 value_primitive_field (struct value
*arg1
, int offset
,
2427 int fieldno
, struct type
*arg_type
)
2432 CHECK_TYPEDEF (arg_type
);
2433 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2435 /* Call check_typedef on our type to make sure that, if TYPE
2436 is a TYPE_CODE_TYPEDEF, its length is set to the length
2437 of the target type instead of zero. However, we do not
2438 replace the typedef type by the target type, because we want
2439 to keep the typedef in order to be able to print the type
2440 description correctly. */
2441 check_typedef (type
);
2443 /* Handle packed fields */
2445 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2447 /* Create a new value for the bitfield, with bitpos and bitsize
2448 set. If possible, arrange offset and bitpos so that we can
2449 do a single aligned read of the size of the containing type.
2450 Otherwise, adjust offset to the byte containing the first
2451 bit. Assume that the address, offset, and embedded offset
2452 are sufficiently aligned. */
2453 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2454 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2456 v
= allocate_value_lazy (type
);
2457 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2458 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2459 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2460 v
->bitpos
= bitpos
% container_bitsize
;
2462 v
->bitpos
= bitpos
% 8;
2463 v
->offset
= (value_embedded_offset (arg1
)
2465 + (bitpos
- v
->bitpos
) / 8);
2467 value_incref (v
->parent
);
2468 if (!value_lazy (arg1
))
2469 value_fetch_lazy (v
);
2471 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2473 /* This field is actually a base subobject, so preserve the
2474 entire object's contents for later references to virtual
2477 /* Lazy register values with offsets are not supported. */
2478 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2479 value_fetch_lazy (arg1
);
2481 if (value_lazy (arg1
))
2482 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2485 v
= allocate_value (value_enclosing_type (arg1
));
2486 value_contents_copy_raw (v
, 0, arg1
, 0,
2487 TYPE_LENGTH (value_enclosing_type (arg1
)));
2490 v
->offset
= value_offset (arg1
);
2491 v
->embedded_offset
= (offset
+ value_embedded_offset (arg1
)
2492 + TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8);
2496 /* Plain old data member */
2497 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2499 /* Lazy register values with offsets are not supported. */
2500 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2501 value_fetch_lazy (arg1
);
2503 if (value_lazy (arg1
))
2504 v
= allocate_value_lazy (type
);
2507 v
= allocate_value (type
);
2508 value_contents_copy_raw (v
, value_embedded_offset (v
),
2509 arg1
, value_embedded_offset (arg1
) + offset
,
2510 TYPE_LENGTH (type
));
2512 v
->offset
= (value_offset (arg1
) + offset
2513 + value_embedded_offset (arg1
));
2515 set_value_component_location (v
, arg1
);
2516 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2517 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2521 /* Given a value ARG1 of a struct or union type,
2522 extract and return the value of one of its (non-static) fields.
2523 FIELDNO says which field. */
2526 value_field (struct value
*arg1
, int fieldno
)
2528 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2531 /* Return a non-virtual function as a value.
2532 F is the list of member functions which contains the desired method.
2533 J is an index into F which provides the desired method.
2535 We only use the symbol for its address, so be happy with either a
2536 full symbol or a minimal symbol. */
2539 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2540 int j
, struct type
*type
,
2544 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2545 char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2547 struct minimal_symbol
*msym
;
2549 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2556 gdb_assert (sym
== NULL
);
2557 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2562 v
= allocate_value (ftype
);
2565 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2569 /* The minimal symbol might point to a function descriptor;
2570 resolve it to the actual code address instead. */
2571 struct objfile
*objfile
= msymbol_objfile (msym
);
2572 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2574 set_value_address (v
,
2575 gdbarch_convert_from_func_ptr_addr
2576 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2581 if (type
!= value_type (*arg1p
))
2582 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2583 value_addr (*arg1p
)));
2585 /* Move the `this' pointer according to the offset.
2586 VALUE_OFFSET (*arg1p) += offset; */
2594 /* Helper function for both unpack_value_bits_as_long and
2595 unpack_bits_as_long. See those functions for more details on the
2596 interface; the only difference is that this function accepts either
2597 a NULL or a non-NULL ORIGINAL_VALUE. */
2600 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2601 int embedded_offset
, int bitpos
, int bitsize
,
2602 const struct value
*original_value
,
2605 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2612 /* Read the minimum number of bytes required; there may not be
2613 enough bytes to read an entire ULONGEST. */
2614 CHECK_TYPEDEF (field_type
);
2616 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2618 bytes_read
= TYPE_LENGTH (field_type
);
2620 read_offset
= bitpos
/ 8;
2622 if (original_value
!= NULL
2623 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2627 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2628 bytes_read
, byte_order
);
2630 /* Extract bits. See comment above. */
2632 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2633 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2635 lsbcount
= (bitpos
% 8);
2638 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2639 If the field is signed, and is negative, then sign extend. */
2641 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2643 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2645 if (!TYPE_UNSIGNED (field_type
))
2647 if (val
& (valmask
^ (valmask
>> 1)))
2658 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2659 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2660 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2661 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2664 Returns false if the value contents are unavailable, otherwise
2665 returns true, indicating a valid value has been stored in *RESULT.
2667 Extracting bits depends on endianness of the machine. Compute the
2668 number of least significant bits to discard. For big endian machines,
2669 we compute the total number of bits in the anonymous object, subtract
2670 off the bit count from the MSB of the object to the MSB of the
2671 bitfield, then the size of the bitfield, which leaves the LSB discard
2672 count. For little endian machines, the discard count is simply the
2673 number of bits from the LSB of the anonymous object to the LSB of the
2676 If the field is signed, we also do sign extension. */
2679 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2680 int embedded_offset
, int bitpos
, int bitsize
,
2681 const struct value
*original_value
,
2684 gdb_assert (original_value
!= NULL
);
2686 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2687 bitpos
, bitsize
, original_value
, result
);
2691 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2692 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2693 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2697 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2698 int embedded_offset
, int fieldno
,
2699 const struct value
*val
, LONGEST
*result
)
2701 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2702 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2703 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2705 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2706 bitpos
, bitsize
, val
,
2710 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2711 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2712 ORIGINAL_VALUE, which must not be NULL. See
2713 unpack_value_bits_as_long for more details. */
2716 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2717 int embedded_offset
, int fieldno
,
2718 const struct value
*val
, LONGEST
*result
)
2720 gdb_assert (val
!= NULL
);
2722 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2723 fieldno
, val
, result
);
2726 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2727 object at VALADDR. See unpack_value_bits_as_long for more details.
2728 This function differs from unpack_value_field_as_long in that it
2729 operates without a struct value object. */
2732 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2736 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2740 /* Return a new value with type TYPE, which is FIELDNO field of the
2741 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2742 of VAL. If the VAL's contents required to extract the bitfield
2743 from are unavailable, the new value is correspondingly marked as
2747 value_field_bitfield (struct type
*type
, int fieldno
,
2748 const gdb_byte
*valaddr
,
2749 int embedded_offset
, const struct value
*val
)
2753 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2756 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2757 struct value
*retval
= allocate_value (field_type
);
2758 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2763 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2767 /* Modify the value of a bitfield. ADDR points to a block of memory in
2768 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2769 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2770 indicate which bits (in target bit order) comprise the bitfield.
2771 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2772 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2775 modify_field (struct type
*type
, gdb_byte
*addr
,
2776 LONGEST fieldval
, int bitpos
, int bitsize
)
2778 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2780 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2783 /* Normalize BITPOS. */
2787 /* If a negative fieldval fits in the field in question, chop
2788 off the sign extension bits. */
2789 if ((~fieldval
& ~(mask
>> 1)) == 0)
2792 /* Warn if value is too big to fit in the field in question. */
2793 if (0 != (fieldval
& ~mask
))
2795 /* FIXME: would like to include fieldval in the message, but
2796 we don't have a sprintf_longest. */
2797 warning (_("Value does not fit in %d bits."), bitsize
);
2799 /* Truncate it, otherwise adjoining fields may be corrupted. */
2803 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2804 false valgrind reports. */
2806 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2807 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2809 /* Shifting for bit field depends on endianness of the target machine. */
2810 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2811 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2813 oword
&= ~(mask
<< bitpos
);
2814 oword
|= fieldval
<< bitpos
;
2816 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2819 /* Pack NUM into BUF using a target format of TYPE. */
2822 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2824 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2827 type
= check_typedef (type
);
2828 len
= TYPE_LENGTH (type
);
2830 switch (TYPE_CODE (type
))
2833 case TYPE_CODE_CHAR
:
2834 case TYPE_CODE_ENUM
:
2835 case TYPE_CODE_FLAGS
:
2836 case TYPE_CODE_BOOL
:
2837 case TYPE_CODE_RANGE
:
2838 case TYPE_CODE_MEMBERPTR
:
2839 store_signed_integer (buf
, len
, byte_order
, num
);
2844 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2848 error (_("Unexpected type (%d) encountered for integer constant."),
2854 /* Pack NUM into BUF using a target format of TYPE. */
2857 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2860 enum bfd_endian byte_order
;
2862 type
= check_typedef (type
);
2863 len
= TYPE_LENGTH (type
);
2864 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2866 switch (TYPE_CODE (type
))
2869 case TYPE_CODE_CHAR
:
2870 case TYPE_CODE_ENUM
:
2871 case TYPE_CODE_FLAGS
:
2872 case TYPE_CODE_BOOL
:
2873 case TYPE_CODE_RANGE
:
2874 case TYPE_CODE_MEMBERPTR
:
2875 store_unsigned_integer (buf
, len
, byte_order
, num
);
2880 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2884 error (_("Unexpected type (%d) encountered "
2885 "for unsigned integer constant."),
2891 /* Convert C numbers into newly allocated values. */
2894 value_from_longest (struct type
*type
, LONGEST num
)
2896 struct value
*val
= allocate_value (type
);
2898 pack_long (value_contents_raw (val
), type
, num
);
2903 /* Convert C unsigned numbers into newly allocated values. */
2906 value_from_ulongest (struct type
*type
, ULONGEST num
)
2908 struct value
*val
= allocate_value (type
);
2910 pack_unsigned_long (value_contents_raw (val
), type
, num
);
2916 /* Create a value representing a pointer of type TYPE to the address
2919 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
2921 struct value
*val
= allocate_value (type
);
2923 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
2928 /* Create a value of type TYPE whose contents come from VALADDR, if it
2929 is non-null, and whose memory address (in the inferior) is
2933 value_from_contents_and_address (struct type
*type
,
2934 const gdb_byte
*valaddr
,
2939 if (valaddr
== NULL
)
2940 v
= allocate_value_lazy (type
);
2943 v
= allocate_value (type
);
2944 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
2946 set_value_address (v
, address
);
2947 VALUE_LVAL (v
) = lval_memory
;
2952 value_from_double (struct type
*type
, DOUBLEST num
)
2954 struct value
*val
= allocate_value (type
);
2955 struct type
*base_type
= check_typedef (type
);
2956 enum type_code code
= TYPE_CODE (base_type
);
2958 if (code
== TYPE_CODE_FLT
)
2960 store_typed_floating (value_contents_raw (val
), base_type
, num
);
2963 error (_("Unexpected type encountered for floating constant."));
2969 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
2971 struct value
*val
= allocate_value (type
);
2973 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
2978 coerce_ref (struct value
*arg
)
2980 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
2982 if (TYPE_CODE (value_type_arg_tmp
) == TYPE_CODE_REF
)
2983 arg
= value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp
),
2984 unpack_pointer (value_type (arg
),
2985 value_contents (arg
)));
2990 coerce_array (struct value
*arg
)
2994 arg
= coerce_ref (arg
);
2995 type
= check_typedef (value_type (arg
));
2997 switch (TYPE_CODE (type
))
2999 case TYPE_CODE_ARRAY
:
3000 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3001 arg
= value_coerce_array (arg
);
3003 case TYPE_CODE_FUNC
:
3004 arg
= value_coerce_function (arg
);
3011 /* Return true if the function returning the specified type is using
3012 the convention of returning structures in memory (passing in the
3013 address as a hidden first parameter). */
3016 using_struct_return (struct gdbarch
*gdbarch
,
3017 struct type
*func_type
, struct type
*value_type
)
3019 enum type_code code
= TYPE_CODE (value_type
);
3021 if (code
== TYPE_CODE_ERROR
)
3022 error (_("Function return type unknown."));
3024 if (code
== TYPE_CODE_VOID
)
3025 /* A void return value is never in memory. See also corresponding
3026 code in "print_return_value". */
3029 /* Probe the architecture for the return-value convention. */
3030 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3032 != RETURN_VALUE_REGISTER_CONVENTION
);
3035 /* Set the initialized field in a value struct. */
3038 set_value_initialized (struct value
*val
, int status
)
3040 val
->initialized
= status
;
3043 /* Return the initialized field in a value struct. */
3046 value_initialized (struct value
*val
)
3048 return val
->initialized
;
3052 _initialize_values (void)
3054 add_cmd ("convenience", no_class
, show_convenience
, _("\
3055 Debugger convenience (\"$foo\") variables.\n\
3056 These variables are created when you assign them values;\n\
3057 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3059 A few convenience variables are given values automatically:\n\
3060 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3061 \"$__\" holds the contents of the last address examined with \"x\"."),
3064 add_cmd ("values", no_class
, show_values
, _("\
3065 Elements of value history around item number IDX (or last ten)."),
3068 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3069 Initialize a convenience variable if necessary.\n\
3070 init-if-undefined VARIABLE = EXPRESSION\n\
3071 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3072 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3073 VARIABLE is already initialized."));
3075 add_prefix_cmd ("function", no_class
, function_command
, _("\
3076 Placeholder command for showing help on convenience functions."),
3077 &functionlist
, "function ", 0, &cmdlist
);