1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2013 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
22 #include "gdb_string.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
46 /* Prototypes for exported functions. */
48 void _initialize_values (void);
50 /* Definition of a user function. */
51 struct internal_function
53 /* The name of the function. It is a bit odd to have this in the
54 function itself -- the user might use a differently-named
55 convenience variable to hold the function. */
59 internal_function_fn handler
;
61 /* User data for the handler. */
65 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
69 /* Lowest offset in the range. */
72 /* Length of the range. */
76 typedef struct range range_s
;
80 /* Returns true if the ranges defined by [offset1, offset1+len1) and
81 [offset2, offset2+len2) overlap. */
84 ranges_overlap (int offset1
, int len1
,
85 int offset2
, int len2
)
89 l
= max (offset1
, offset2
);
90 h
= min (offset1
+ len1
, offset2
+ len2
);
94 /* Returns true if the first argument is strictly less than the
95 second, useful for VEC_lower_bound. We keep ranges sorted by
96 offset and coalesce overlapping and contiguous ranges, so this just
97 compares the starting offset. */
100 range_lessthan (const range_s
*r1
, const range_s
*r2
)
102 return r1
->offset
< r2
->offset
;
105 /* Returns true if RANGES contains any range that overlaps [OFFSET,
109 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
114 what
.offset
= offset
;
115 what
.length
= length
;
117 /* We keep ranges sorted by offset and coalesce overlapping and
118 contiguous ranges, so to check if a range list contains a given
119 range, we can do a binary search for the position the given range
120 would be inserted if we only considered the starting OFFSET of
121 ranges. We call that position I. Since we also have LENGTH to
122 care for (this is a range afterall), we need to check if the
123 _previous_ range overlaps the I range. E.g.,
127 |---| |---| |------| ... |--|
132 In the case above, the binary search would return `I=1', meaning,
133 this OFFSET should be inserted at position 1, and the current
134 position 1 should be pushed further (and before 2). But, `0'
137 Then we need to check if the I range overlaps the I range itself.
142 |---| |---| |-------| ... |--|
148 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
152 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
154 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
158 if (i
< VEC_length (range_s
, ranges
))
160 struct range
*r
= VEC_index (range_s
, ranges
, i
);
162 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
169 static struct cmd_list_element
*functionlist
;
171 /* Note that the fields in this structure are arranged to save a bit
176 /* Type of value; either not an lval, or one of the various
177 different possible kinds of lval. */
180 /* Is it modifiable? Only relevant if lval != not_lval. */
181 unsigned int modifiable
: 1;
183 /* If zero, contents of this value are in the contents field. If
184 nonzero, contents are in inferior. If the lval field is lval_memory,
185 the contents are in inferior memory at location.address plus offset.
186 The lval field may also be lval_register.
188 WARNING: This field is used by the code which handles watchpoints
189 (see breakpoint.c) to decide whether a particular value can be
190 watched by hardware watchpoints. If the lazy flag is set for
191 some member of a value chain, it is assumed that this member of
192 the chain doesn't need to be watched as part of watching the
193 value itself. This is how GDB avoids watching the entire struct
194 or array when the user wants to watch a single struct member or
195 array element. If you ever change the way lazy flag is set and
196 reset, be sure to consider this use as well! */
197 unsigned int lazy
: 1;
199 /* If nonzero, this is the value of a variable which does not
200 actually exist in the program. */
201 unsigned int optimized_out
: 1;
203 /* If value is a variable, is it initialized or not. */
204 unsigned int initialized
: 1;
206 /* If value is from the stack. If this is set, read_stack will be
207 used instead of read_memory to enable extra caching. */
208 unsigned int stack
: 1;
210 /* If the value has been released. */
211 unsigned int released
: 1;
213 /* Location of value (if lval). */
216 /* If lval == lval_memory, this is the address in the inferior.
217 If lval == lval_register, this is the byte offset into the
218 registers structure. */
221 /* Pointer to internal variable. */
222 struct internalvar
*internalvar
;
224 /* If lval == lval_computed, this is a set of function pointers
225 to use to access and describe the value, and a closure pointer
229 /* Functions to call. */
230 const struct lval_funcs
*funcs
;
232 /* Closure for those functions to use. */
237 /* Describes offset of a value within lval of a structure in bytes.
238 If lval == lval_memory, this is an offset to the address. If
239 lval == lval_register, this is a further offset from
240 location.address within the registers structure. Note also the
241 member embedded_offset below. */
244 /* Only used for bitfields; number of bits contained in them. */
247 /* Only used for bitfields; position of start of field. For
248 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
249 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
252 /* The number of references to this value. When a value is created,
253 the value chain holds a reference, so REFERENCE_COUNT is 1. If
254 release_value is called, this value is removed from the chain but
255 the caller of release_value now has a reference to this value.
256 The caller must arrange for a call to value_free later. */
259 /* Only used for bitfields; the containing value. This allows a
260 single read from the target when displaying multiple
262 struct value
*parent
;
264 /* Frame register value is relative to. This will be described in
265 the lval enum above as "lval_register". */
266 struct frame_id frame_id
;
268 /* Type of the value. */
271 /* If a value represents a C++ object, then the `type' field gives
272 the object's compile-time type. If the object actually belongs
273 to some class derived from `type', perhaps with other base
274 classes and additional members, then `type' is just a subobject
275 of the real thing, and the full object is probably larger than
276 `type' would suggest.
278 If `type' is a dynamic class (i.e. one with a vtable), then GDB
279 can actually determine the object's run-time type by looking at
280 the run-time type information in the vtable. When this
281 information is available, we may elect to read in the entire
282 object, for several reasons:
284 - When printing the value, the user would probably rather see the
285 full object, not just the limited portion apparent from the
288 - If `type' has virtual base classes, then even printing `type'
289 alone may require reaching outside the `type' portion of the
290 object to wherever the virtual base class has been stored.
292 When we store the entire object, `enclosing_type' is the run-time
293 type -- the complete object -- and `embedded_offset' is the
294 offset of `type' within that larger type, in bytes. The
295 value_contents() macro takes `embedded_offset' into account, so
296 most GDB code continues to see the `type' portion of the value,
297 just as the inferior would.
299 If `type' is a pointer to an object, then `enclosing_type' is a
300 pointer to the object's run-time type, and `pointed_to_offset' is
301 the offset in bytes from the full object to the pointed-to object
302 -- that is, the value `embedded_offset' would have if we followed
303 the pointer and fetched the complete object. (I don't really see
304 the point. Why not just determine the run-time type when you
305 indirect, and avoid the special case? The contents don't matter
306 until you indirect anyway.)
308 If we're not doing anything fancy, `enclosing_type' is equal to
309 `type', and `embedded_offset' is zero, so everything works
311 struct type
*enclosing_type
;
313 int pointed_to_offset
;
315 /* Values are stored in a chain, so that they can be deleted easily
316 over calls to the inferior. Values assigned to internal
317 variables, put into the value history or exposed to Python are
318 taken off this list. */
321 /* Register number if the value is from a register. */
324 /* Actual contents of the value. Target byte-order. NULL or not
325 valid if lazy is nonzero. */
328 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
329 rather than available, since the common and default case is for a
330 value to be available. This is filled in at value read time. */
331 VEC(range_s
) *unavailable
;
335 value_bytes_available (const struct value
*value
, int offset
, int length
)
337 gdb_assert (!value
->lazy
);
339 return !ranges_contain (value
->unavailable
, offset
, length
);
343 value_entirely_available (struct value
*value
)
345 /* We can only tell whether the whole value is available when we try
348 value_fetch_lazy (value
);
350 if (VEC_empty (range_s
, value
->unavailable
))
356 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
361 /* Insert the range sorted. If there's overlap or the new range
362 would be contiguous with an existing range, merge. */
364 newr
.offset
= offset
;
365 newr
.length
= length
;
367 /* Do a binary search for the position the given range would be
368 inserted if we only considered the starting OFFSET of ranges.
369 Call that position I. Since we also have LENGTH to care for
370 (this is a range afterall), we need to check if the _previous_
371 range overlaps the I range. E.g., calling R the new range:
373 #1 - overlaps with previous
377 |---| |---| |------| ... |--|
382 In the case #1 above, the binary search would return `I=1',
383 meaning, this OFFSET should be inserted at position 1, and the
384 current position 1 should be pushed further (and become 2). But,
385 note that `0' overlaps with R, so we want to merge them.
387 A similar consideration needs to be taken if the new range would
388 be contiguous with the previous range:
390 #2 - contiguous with previous
394 |--| |---| |------| ... |--|
399 If there's no overlap with the previous range, as in:
401 #3 - not overlapping and not contiguous
405 |--| |---| |------| ... |--|
412 #4 - R is the range with lowest offset
416 |--| |---| |------| ... |--|
421 ... we just push the new range to I.
423 All the 4 cases above need to consider that the new range may
424 also overlap several of the ranges that follow, or that R may be
425 contiguous with the following range, and merge. E.g.,
427 #5 - overlapping following ranges
430 |------------------------|
431 |--| |---| |------| ... |--|
440 |--| |---| |------| ... |--|
447 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
450 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
452 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
455 ULONGEST l
= min (bef
->offset
, offset
);
456 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
462 else if (offset
== bef
->offset
+ bef
->length
)
465 bef
->length
+= length
;
471 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
477 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
480 /* Check whether the ranges following the one we've just added or
481 touched can be folded in (#5 above). */
482 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
489 /* Get the range we just touched. */
490 t
= VEC_index (range_s
, value
->unavailable
, i
);
494 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
495 if (r
->offset
<= t
->offset
+ t
->length
)
499 l
= min (t
->offset
, r
->offset
);
500 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
509 /* If we couldn't merge this one, we won't be able to
510 merge following ones either, since the ranges are
511 always sorted by OFFSET. */
516 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
520 /* Find the first range in RANGES that overlaps the range defined by
521 OFFSET and LENGTH, starting at element POS in the RANGES vector,
522 Returns the index into RANGES where such overlapping range was
523 found, or -1 if none was found. */
526 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
527 int offset
, int length
)
532 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
533 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
540 value_available_contents_eq (const struct value
*val1
, int offset1
,
541 const struct value
*val2
, int offset2
,
544 int idx1
= 0, idx2
= 0;
546 /* See function description in value.h. */
547 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
555 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
557 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
560 /* The usual case is for both values to be completely available. */
561 if (idx1
== -1 && idx2
== -1)
562 return (memcmp (val1
->contents
+ offset1
,
563 val2
->contents
+ offset2
,
565 /* The contents only match equal if the available set matches as
567 else if (idx1
== -1 || idx2
== -1)
570 gdb_assert (idx1
!= -1 && idx2
!= -1);
572 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
573 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
575 /* Get the unavailable windows intersected by the incoming
576 ranges. The first and last ranges that overlap the argument
577 range may be wider than said incoming arguments ranges. */
578 l1
= max (offset1
, r1
->offset
);
579 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
581 l2
= max (offset2
, r2
->offset
);
582 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
584 /* Make them relative to the respective start offsets, so we can
585 compare them for equality. */
592 /* Different availability, no match. */
593 if (l1
!= l2
|| h1
!= h2
)
596 /* Compare the _available_ contents. */
597 if (memcmp (val1
->contents
+ offset1
,
598 val2
->contents
+ offset2
,
610 /* Prototypes for local functions. */
612 static void show_values (char *, int);
614 static void show_convenience (char *, int);
617 /* The value-history records all the values printed
618 by print commands during this session. Each chunk
619 records 60 consecutive values. The first chunk on
620 the chain records the most recent values.
621 The total number of values is in value_history_count. */
623 #define VALUE_HISTORY_CHUNK 60
625 struct value_history_chunk
627 struct value_history_chunk
*next
;
628 struct value
*values
[VALUE_HISTORY_CHUNK
];
631 /* Chain of chunks now in use. */
633 static struct value_history_chunk
*value_history_chain
;
635 static int value_history_count
; /* Abs number of last entry stored. */
638 /* List of all value objects currently allocated
639 (except for those released by calls to release_value)
640 This is so they can be freed after each command. */
642 static struct value
*all_values
;
644 /* Allocate a lazy value for type TYPE. Its actual content is
645 "lazily" allocated too: the content field of the return value is
646 NULL; it will be allocated when it is fetched from the target. */
649 allocate_value_lazy (struct type
*type
)
653 /* Call check_typedef on our type to make sure that, if TYPE
654 is a TYPE_CODE_TYPEDEF, its length is set to the length
655 of the target type instead of zero. However, we do not
656 replace the typedef type by the target type, because we want
657 to keep the typedef in order to be able to set the VAL's type
658 description correctly. */
659 check_typedef (type
);
661 val
= (struct value
*) xzalloc (sizeof (struct value
));
662 val
->contents
= NULL
;
663 val
->next
= all_values
;
666 val
->enclosing_type
= type
;
667 VALUE_LVAL (val
) = not_lval
;
668 val
->location
.address
= 0;
669 VALUE_FRAME_ID (val
) = null_frame_id
;
673 VALUE_REGNUM (val
) = -1;
675 val
->optimized_out
= 0;
676 val
->embedded_offset
= 0;
677 val
->pointed_to_offset
= 0;
679 val
->initialized
= 1; /* Default to initialized. */
681 /* Values start out on the all_values chain. */
682 val
->reference_count
= 1;
687 /* Allocate the contents of VAL if it has not been allocated yet. */
690 allocate_value_contents (struct value
*val
)
693 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
696 /* Allocate a value and its contents for type TYPE. */
699 allocate_value (struct type
*type
)
701 struct value
*val
= allocate_value_lazy (type
);
703 allocate_value_contents (val
);
708 /* Allocate a value that has the correct length
709 for COUNT repetitions of type TYPE. */
712 allocate_repeat_value (struct type
*type
, int count
)
714 int low_bound
= current_language
->string_lower_bound
; /* ??? */
715 /* FIXME-type-allocation: need a way to free this type when we are
717 struct type
*array_type
718 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
720 return allocate_value (array_type
);
724 allocate_computed_value (struct type
*type
,
725 const struct lval_funcs
*funcs
,
728 struct value
*v
= allocate_value_lazy (type
);
730 VALUE_LVAL (v
) = lval_computed
;
731 v
->location
.computed
.funcs
= funcs
;
732 v
->location
.computed
.closure
= closure
;
737 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
740 allocate_optimized_out_value (struct type
*type
)
742 struct value
*retval
= allocate_value_lazy (type
);
744 set_value_optimized_out (retval
, 1);
749 /* Accessor methods. */
752 value_next (struct value
*value
)
758 value_type (const struct value
*value
)
763 deprecated_set_value_type (struct value
*value
, struct type
*type
)
769 value_offset (const struct value
*value
)
771 return value
->offset
;
774 set_value_offset (struct value
*value
, int offset
)
776 value
->offset
= offset
;
780 value_bitpos (const struct value
*value
)
782 return value
->bitpos
;
785 set_value_bitpos (struct value
*value
, int bit
)
791 value_bitsize (const struct value
*value
)
793 return value
->bitsize
;
796 set_value_bitsize (struct value
*value
, int bit
)
798 value
->bitsize
= bit
;
802 value_parent (struct value
*value
)
804 return value
->parent
;
810 set_value_parent (struct value
*value
, struct value
*parent
)
812 struct value
*old
= value
->parent
;
814 value
->parent
= parent
;
816 value_incref (parent
);
821 value_contents_raw (struct value
*value
)
823 allocate_value_contents (value
);
824 return value
->contents
+ value
->embedded_offset
;
828 value_contents_all_raw (struct value
*value
)
830 allocate_value_contents (value
);
831 return value
->contents
;
835 value_enclosing_type (struct value
*value
)
837 return value
->enclosing_type
;
840 /* Look at value.h for description. */
843 value_actual_type (struct value
*value
, int resolve_simple_types
,
844 int *real_type_found
)
846 struct value_print_options opts
;
849 get_user_print_options (&opts
);
852 *real_type_found
= 0;
853 result
= value_type (value
);
854 if (opts
.objectprint
)
856 /* If result's target type is TYPE_CODE_STRUCT, proceed to
857 fetch its rtti type. */
858 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
859 || TYPE_CODE (result
) == TYPE_CODE_REF
)
860 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
863 struct type
*real_type
;
865 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
869 *real_type_found
= 1;
873 else if (resolve_simple_types
)
876 *real_type_found
= 1;
877 result
= value_enclosing_type (value
);
885 require_not_optimized_out (const struct value
*value
)
887 if (value
->optimized_out
)
888 error (_("value has been optimized out"));
892 require_available (const struct value
*value
)
894 if (!VEC_empty (range_s
, value
->unavailable
))
895 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
899 value_contents_for_printing (struct value
*value
)
902 value_fetch_lazy (value
);
903 return value
->contents
;
907 value_contents_for_printing_const (const struct value
*value
)
909 gdb_assert (!value
->lazy
);
910 return value
->contents
;
914 value_contents_all (struct value
*value
)
916 const gdb_byte
*result
= value_contents_for_printing (value
);
917 require_not_optimized_out (value
);
918 require_available (value
);
922 /* Copy LENGTH bytes of SRC value's (all) contents
923 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
924 contents, starting at DST_OFFSET. If unavailable contents are
925 being copied from SRC, the corresponding DST contents are marked
926 unavailable accordingly. Neither DST nor SRC may be lazy
929 It is assumed the contents of DST in the [DST_OFFSET,
930 DST_OFFSET+LENGTH) range are wholly available. */
933 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
934 struct value
*src
, int src_offset
, int length
)
939 /* A lazy DST would make that this copy operation useless, since as
940 soon as DST's contents were un-lazied (by a later value_contents
941 call, say), the contents would be overwritten. A lazy SRC would
942 mean we'd be copying garbage. */
943 gdb_assert (!dst
->lazy
&& !src
->lazy
);
945 /* The overwritten DST range gets unavailability ORed in, not
946 replaced. Make sure to remember to implement replacing if it
947 turns out actually necessary. */
948 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
951 memcpy (value_contents_all_raw (dst
) + dst_offset
,
952 value_contents_all_raw (src
) + src_offset
,
955 /* Copy the meta-data, adjusted. */
956 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
960 l
= max (r
->offset
, src_offset
);
961 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
964 mark_value_bytes_unavailable (dst
,
965 dst_offset
+ (l
- src_offset
),
970 /* Copy LENGTH bytes of SRC value's (all) contents
971 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
972 (all) contents, starting at DST_OFFSET. If unavailable contents
973 are being copied from SRC, the corresponding DST contents are
974 marked unavailable accordingly. DST must not be lazy. If SRC is
975 lazy, it will be fetched now. If SRC is not valid (is optimized
976 out), an error is thrown.
978 It is assumed the contents of DST in the [DST_OFFSET,
979 DST_OFFSET+LENGTH) range are wholly available. */
982 value_contents_copy (struct value
*dst
, int dst_offset
,
983 struct value
*src
, int src_offset
, int length
)
985 require_not_optimized_out (src
);
988 value_fetch_lazy (src
);
990 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
994 value_lazy (struct value
*value
)
1000 set_value_lazy (struct value
*value
, int val
)
1006 value_stack (struct value
*value
)
1008 return value
->stack
;
1012 set_value_stack (struct value
*value
, int val
)
1018 value_contents (struct value
*value
)
1020 const gdb_byte
*result
= value_contents_writeable (value
);
1021 require_not_optimized_out (value
);
1022 require_available (value
);
1027 value_contents_writeable (struct value
*value
)
1030 value_fetch_lazy (value
);
1031 return value_contents_raw (value
);
1034 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1035 this function is different from value_equal; in C the operator ==
1036 can return 0 even if the two values being compared are equal. */
1039 value_contents_equal (struct value
*val1
, struct value
*val2
)
1044 type1
= check_typedef (value_type (val1
));
1045 type2
= check_typedef (value_type (val2
));
1046 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1049 return (memcmp (value_contents (val1
), value_contents (val2
),
1050 TYPE_LENGTH (type1
)) == 0);
1054 value_optimized_out (struct value
*value
)
1056 return value
->optimized_out
;
1060 set_value_optimized_out (struct value
*value
, int val
)
1062 value
->optimized_out
= val
;
1066 value_entirely_optimized_out (const struct value
*value
)
1068 if (!value
->optimized_out
)
1070 if (value
->lval
!= lval_computed
1071 || !value
->location
.computed
.funcs
->check_any_valid
)
1073 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1077 value_bits_valid (const struct value
*value
, int offset
, int length
)
1079 if (!value
->optimized_out
)
1081 if (value
->lval
!= lval_computed
1082 || !value
->location
.computed
.funcs
->check_validity
)
1084 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1089 value_bits_synthetic_pointer (const struct value
*value
,
1090 int offset
, int length
)
1092 if (value
->lval
!= lval_computed
1093 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1095 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1101 value_embedded_offset (struct value
*value
)
1103 return value
->embedded_offset
;
1107 set_value_embedded_offset (struct value
*value
, int val
)
1109 value
->embedded_offset
= val
;
1113 value_pointed_to_offset (struct value
*value
)
1115 return value
->pointed_to_offset
;
1119 set_value_pointed_to_offset (struct value
*value
, int val
)
1121 value
->pointed_to_offset
= val
;
1124 const struct lval_funcs
*
1125 value_computed_funcs (const struct value
*v
)
1127 gdb_assert (value_lval_const (v
) == lval_computed
);
1129 return v
->location
.computed
.funcs
;
1133 value_computed_closure (const struct value
*v
)
1135 gdb_assert (v
->lval
== lval_computed
);
1137 return v
->location
.computed
.closure
;
1141 deprecated_value_lval_hack (struct value
*value
)
1143 return &value
->lval
;
1147 value_lval_const (const struct value
*value
)
1153 value_address (const struct value
*value
)
1155 if (value
->lval
== lval_internalvar
1156 || value
->lval
== lval_internalvar_component
)
1158 if (value
->parent
!= NULL
)
1159 return value_address (value
->parent
) + value
->offset
;
1161 return value
->location
.address
+ value
->offset
;
1165 value_raw_address (struct value
*value
)
1167 if (value
->lval
== lval_internalvar
1168 || value
->lval
== lval_internalvar_component
)
1170 return value
->location
.address
;
1174 set_value_address (struct value
*value
, CORE_ADDR addr
)
1176 gdb_assert (value
->lval
!= lval_internalvar
1177 && value
->lval
!= lval_internalvar_component
);
1178 value
->location
.address
= addr
;
1181 struct internalvar
**
1182 deprecated_value_internalvar_hack (struct value
*value
)
1184 return &value
->location
.internalvar
;
1188 deprecated_value_frame_id_hack (struct value
*value
)
1190 return &value
->frame_id
;
1194 deprecated_value_regnum_hack (struct value
*value
)
1196 return &value
->regnum
;
1200 deprecated_value_modifiable (struct value
*value
)
1202 return value
->modifiable
;
1205 /* Return a mark in the value chain. All values allocated after the
1206 mark is obtained (except for those released) are subject to being freed
1207 if a subsequent value_free_to_mark is passed the mark. */
1214 /* Take a reference to VAL. VAL will not be deallocated until all
1215 references are released. */
1218 value_incref (struct value
*val
)
1220 val
->reference_count
++;
1223 /* Release a reference to VAL, which was acquired with value_incref.
1224 This function is also called to deallocate values from the value
1228 value_free (struct value
*val
)
1232 gdb_assert (val
->reference_count
> 0);
1233 val
->reference_count
--;
1234 if (val
->reference_count
> 0)
1237 /* If there's an associated parent value, drop our reference to
1239 if (val
->parent
!= NULL
)
1240 value_free (val
->parent
);
1242 if (VALUE_LVAL (val
) == lval_computed
)
1244 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1246 if (funcs
->free_closure
)
1247 funcs
->free_closure (val
);
1250 xfree (val
->contents
);
1251 VEC_free (range_s
, val
->unavailable
);
1256 /* Free all values allocated since MARK was obtained by value_mark
1257 (except for those released). */
1259 value_free_to_mark (struct value
*mark
)
1264 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1273 /* Free all the values that have been allocated (except for those released).
1274 Call after each command, successful or not.
1275 In practice this is called before each command, which is sufficient. */
1278 free_all_values (void)
1283 for (val
= all_values
; val
; val
= next
)
1293 /* Frees all the elements in a chain of values. */
1296 free_value_chain (struct value
*v
)
1302 next
= value_next (v
);
1307 /* Remove VAL from the chain all_values
1308 so it will not be freed automatically. */
1311 release_value (struct value
*val
)
1315 if (all_values
== val
)
1317 all_values
= val
->next
;
1323 for (v
= all_values
; v
; v
= v
->next
)
1327 v
->next
= val
->next
;
1335 /* If the value is not already released, release it.
1336 If the value is already released, increment its reference count.
1337 That is, this function ensures that the value is released from the
1338 value chain and that the caller owns a reference to it. */
1341 release_value_or_incref (struct value
*val
)
1346 release_value (val
);
1349 /* Release all values up to mark */
1351 value_release_to_mark (struct value
*mark
)
1356 for (val
= next
= all_values
; next
; next
= next
->next
)
1358 if (next
->next
== mark
)
1360 all_values
= next
->next
;
1370 /* Return a copy of the value ARG.
1371 It contains the same contents, for same memory address,
1372 but it's a different block of storage. */
1375 value_copy (struct value
*arg
)
1377 struct type
*encl_type
= value_enclosing_type (arg
);
1380 if (value_lazy (arg
))
1381 val
= allocate_value_lazy (encl_type
);
1383 val
= allocate_value (encl_type
);
1384 val
->type
= arg
->type
;
1385 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1386 val
->location
= arg
->location
;
1387 val
->offset
= arg
->offset
;
1388 val
->bitpos
= arg
->bitpos
;
1389 val
->bitsize
= arg
->bitsize
;
1390 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1391 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1392 val
->lazy
= arg
->lazy
;
1393 val
->optimized_out
= arg
->optimized_out
;
1394 val
->embedded_offset
= value_embedded_offset (arg
);
1395 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1396 val
->modifiable
= arg
->modifiable
;
1397 if (!value_lazy (val
))
1399 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1400 TYPE_LENGTH (value_enclosing_type (arg
)));
1403 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1404 set_value_parent (val
, arg
->parent
);
1405 if (VALUE_LVAL (val
) == lval_computed
)
1407 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1409 if (funcs
->copy_closure
)
1410 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1415 /* Return a version of ARG that is non-lvalue. */
1418 value_non_lval (struct value
*arg
)
1420 if (VALUE_LVAL (arg
) != not_lval
)
1422 struct type
*enc_type
= value_enclosing_type (arg
);
1423 struct value
*val
= allocate_value (enc_type
);
1425 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1426 TYPE_LENGTH (enc_type
));
1427 val
->type
= arg
->type
;
1428 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1429 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1436 set_value_component_location (struct value
*component
,
1437 const struct value
*whole
)
1439 if (whole
->lval
== lval_internalvar
)
1440 VALUE_LVAL (component
) = lval_internalvar_component
;
1442 VALUE_LVAL (component
) = whole
->lval
;
1444 component
->location
= whole
->location
;
1445 if (whole
->lval
== lval_computed
)
1447 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1449 if (funcs
->copy_closure
)
1450 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1455 /* Access to the value history. */
1457 /* Record a new value in the value history.
1458 Returns the absolute history index of the entry.
1459 Result of -1 indicates the value was not saved; otherwise it is the
1460 value history index of this new item. */
1463 record_latest_value (struct value
*val
)
1467 /* We don't want this value to have anything to do with the inferior anymore.
1468 In particular, "set $1 = 50" should not affect the variable from which
1469 the value was taken, and fast watchpoints should be able to assume that
1470 a value on the value history never changes. */
1471 if (value_lazy (val
))
1472 value_fetch_lazy (val
);
1473 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1474 from. This is a bit dubious, because then *&$1 does not just return $1
1475 but the current contents of that location. c'est la vie... */
1476 val
->modifiable
= 0;
1477 release_value (val
);
1479 /* Here we treat value_history_count as origin-zero
1480 and applying to the value being stored now. */
1482 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1485 struct value_history_chunk
*new
1486 = (struct value_history_chunk
*)
1488 xmalloc (sizeof (struct value_history_chunk
));
1489 memset (new->values
, 0, sizeof new->values
);
1490 new->next
= value_history_chain
;
1491 value_history_chain
= new;
1494 value_history_chain
->values
[i
] = val
;
1496 /* Now we regard value_history_count as origin-one
1497 and applying to the value just stored. */
1499 return ++value_history_count
;
1502 /* Return a copy of the value in the history with sequence number NUM. */
1505 access_value_history (int num
)
1507 struct value_history_chunk
*chunk
;
1512 absnum
+= value_history_count
;
1517 error (_("The history is empty."));
1519 error (_("There is only one value in the history."));
1521 error (_("History does not go back to $$%d."), -num
);
1523 if (absnum
> value_history_count
)
1524 error (_("History has not yet reached $%d."), absnum
);
1528 /* Now absnum is always absolute and origin zero. */
1530 chunk
= value_history_chain
;
1531 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1532 - absnum
/ VALUE_HISTORY_CHUNK
;
1534 chunk
= chunk
->next
;
1536 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1540 show_values (char *num_exp
, int from_tty
)
1548 /* "show values +" should print from the stored position.
1549 "show values <exp>" should print around value number <exp>. */
1550 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1551 num
= parse_and_eval_long (num_exp
) - 5;
1555 /* "show values" means print the last 10 values. */
1556 num
= value_history_count
- 9;
1562 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1564 struct value_print_options opts
;
1566 val
= access_value_history (i
);
1567 printf_filtered (("$%d = "), i
);
1568 get_user_print_options (&opts
);
1569 value_print (val
, gdb_stdout
, &opts
);
1570 printf_filtered (("\n"));
1573 /* The next "show values +" should start after what we just printed. */
1576 /* Hitting just return after this command should do the same thing as
1577 "show values +". If num_exp is null, this is unnecessary, since
1578 "show values +" is not useful after "show values". */
1579 if (from_tty
&& num_exp
)
1586 /* Internal variables. These are variables within the debugger
1587 that hold values assigned by debugger commands.
1588 The user refers to them with a '$' prefix
1589 that does not appear in the variable names stored internally. */
1593 struct internalvar
*next
;
1596 /* We support various different kinds of content of an internal variable.
1597 enum internalvar_kind specifies the kind, and union internalvar_data
1598 provides the data associated with this particular kind. */
1600 enum internalvar_kind
1602 /* The internal variable is empty. */
1605 /* The value of the internal variable is provided directly as
1606 a GDB value object. */
1609 /* A fresh value is computed via a call-back routine on every
1610 access to the internal variable. */
1611 INTERNALVAR_MAKE_VALUE
,
1613 /* The internal variable holds a GDB internal convenience function. */
1614 INTERNALVAR_FUNCTION
,
1616 /* The variable holds an integer value. */
1617 INTERNALVAR_INTEGER
,
1619 /* The variable holds a GDB-provided string. */
1624 union internalvar_data
1626 /* A value object used with INTERNALVAR_VALUE. */
1627 struct value
*value
;
1629 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1632 /* The functions to call. */
1633 const struct internalvar_funcs
*functions
;
1635 /* The function's user-data. */
1639 /* The internal function used with INTERNALVAR_FUNCTION. */
1642 struct internal_function
*function
;
1643 /* True if this is the canonical name for the function. */
1647 /* An integer value used with INTERNALVAR_INTEGER. */
1650 /* If type is non-NULL, it will be used as the type to generate
1651 a value for this internal variable. If type is NULL, a default
1652 integer type for the architecture is used. */
1657 /* A string value used with INTERNALVAR_STRING. */
1662 static struct internalvar
*internalvars
;
1664 /* If the variable does not already exist create it and give it the
1665 value given. If no value is given then the default is zero. */
1667 init_if_undefined_command (char* args
, int from_tty
)
1669 struct internalvar
* intvar
;
1671 /* Parse the expression - this is taken from set_command(). */
1672 struct expression
*expr
= parse_expression (args
);
1673 register struct cleanup
*old_chain
=
1674 make_cleanup (free_current_contents
, &expr
);
1676 /* Validate the expression.
1677 Was the expression an assignment?
1678 Or even an expression at all? */
1679 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1680 error (_("Init-if-undefined requires an assignment expression."));
1682 /* Extract the variable from the parsed expression.
1683 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1684 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1685 error (_("The first parameter to init-if-undefined "
1686 "should be a GDB variable."));
1687 intvar
= expr
->elts
[2].internalvar
;
1689 /* Only evaluate the expression if the lvalue is void.
1690 This may still fail if the expresssion is invalid. */
1691 if (intvar
->kind
== INTERNALVAR_VOID
)
1692 evaluate_expression (expr
);
1694 do_cleanups (old_chain
);
1698 /* Look up an internal variable with name NAME. NAME should not
1699 normally include a dollar sign.
1701 If the specified internal variable does not exist,
1702 the return value is NULL. */
1704 struct internalvar
*
1705 lookup_only_internalvar (const char *name
)
1707 struct internalvar
*var
;
1709 for (var
= internalvars
; var
; var
= var
->next
)
1710 if (strcmp (var
->name
, name
) == 0)
1716 /* Complete NAME by comparing it to the names of internal variables.
1717 Returns a vector of newly allocated strings, or NULL if no matches
1721 complete_internalvar (const char *name
)
1723 VEC (char_ptr
) *result
= NULL
;
1724 struct internalvar
*var
;
1727 len
= strlen (name
);
1729 for (var
= internalvars
; var
; var
= var
->next
)
1730 if (strncmp (var
->name
, name
, len
) == 0)
1732 char *r
= xstrdup (var
->name
);
1734 VEC_safe_push (char_ptr
, result
, r
);
1740 /* Create an internal variable with name NAME and with a void value.
1741 NAME should not normally include a dollar sign. */
1743 struct internalvar
*
1744 create_internalvar (const char *name
)
1746 struct internalvar
*var
;
1748 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1749 var
->name
= concat (name
, (char *)NULL
);
1750 var
->kind
= INTERNALVAR_VOID
;
1751 var
->next
= internalvars
;
1756 /* Create an internal variable with name NAME and register FUN as the
1757 function that value_of_internalvar uses to create a value whenever
1758 this variable is referenced. NAME should not normally include a
1759 dollar sign. DATA is passed uninterpreted to FUN when it is
1760 called. CLEANUP, if not NULL, is called when the internal variable
1761 is destroyed. It is passed DATA as its only argument. */
1763 struct internalvar
*
1764 create_internalvar_type_lazy (const char *name
,
1765 const struct internalvar_funcs
*funcs
,
1768 struct internalvar
*var
= create_internalvar (name
);
1770 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1771 var
->u
.make_value
.functions
= funcs
;
1772 var
->u
.make_value
.data
= data
;
1776 /* See documentation in value.h. */
1779 compile_internalvar_to_ax (struct internalvar
*var
,
1780 struct agent_expr
*expr
,
1781 struct axs_value
*value
)
1783 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1784 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1787 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1788 var
->u
.make_value
.data
);
1792 /* Look up an internal variable with name NAME. NAME should not
1793 normally include a dollar sign.
1795 If the specified internal variable does not exist,
1796 one is created, with a void value. */
1798 struct internalvar
*
1799 lookup_internalvar (const char *name
)
1801 struct internalvar
*var
;
1803 var
= lookup_only_internalvar (name
);
1807 return create_internalvar (name
);
1810 /* Return current value of internal variable VAR. For variables that
1811 are not inherently typed, use a value type appropriate for GDBARCH. */
1814 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1817 struct trace_state_variable
*tsv
;
1819 /* If there is a trace state variable of the same name, assume that
1820 is what we really want to see. */
1821 tsv
= find_trace_state_variable (var
->name
);
1824 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1826 if (tsv
->value_known
)
1827 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1830 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1836 case INTERNALVAR_VOID
:
1837 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1840 case INTERNALVAR_FUNCTION
:
1841 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1844 case INTERNALVAR_INTEGER
:
1845 if (!var
->u
.integer
.type
)
1846 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1847 var
->u
.integer
.val
);
1849 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1852 case INTERNALVAR_STRING
:
1853 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1854 builtin_type (gdbarch
)->builtin_char
);
1857 case INTERNALVAR_VALUE
:
1858 val
= value_copy (var
->u
.value
);
1859 if (value_lazy (val
))
1860 value_fetch_lazy (val
);
1863 case INTERNALVAR_MAKE_VALUE
:
1864 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
1865 var
->u
.make_value
.data
);
1869 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1872 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1873 on this value go back to affect the original internal variable.
1875 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1876 no underlying modifyable state in the internal variable.
1878 Likewise, if the variable's value is a computed lvalue, we want
1879 references to it to produce another computed lvalue, where
1880 references and assignments actually operate through the
1881 computed value's functions.
1883 This means that internal variables with computed values
1884 behave a little differently from other internal variables:
1885 assignments to them don't just replace the previous value
1886 altogether. At the moment, this seems like the behavior we
1889 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1890 && val
->lval
!= lval_computed
)
1892 VALUE_LVAL (val
) = lval_internalvar
;
1893 VALUE_INTERNALVAR (val
) = var
;
1900 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1902 if (var
->kind
== INTERNALVAR_INTEGER
)
1904 *result
= var
->u
.integer
.val
;
1908 if (var
->kind
== INTERNALVAR_VALUE
)
1910 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1912 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1914 *result
= value_as_long (var
->u
.value
);
1923 get_internalvar_function (struct internalvar
*var
,
1924 struct internal_function
**result
)
1928 case INTERNALVAR_FUNCTION
:
1929 *result
= var
->u
.fn
.function
;
1938 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1939 int bitsize
, struct value
*newval
)
1945 case INTERNALVAR_VALUE
:
1946 addr
= value_contents_writeable (var
->u
.value
);
1949 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1950 value_as_long (newval
), bitpos
, bitsize
);
1952 memcpy (addr
+ offset
, value_contents (newval
),
1953 TYPE_LENGTH (value_type (newval
)));
1957 /* We can never get a component of any other kind. */
1958 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1963 set_internalvar (struct internalvar
*var
, struct value
*val
)
1965 enum internalvar_kind new_kind
;
1966 union internalvar_data new_data
= { 0 };
1968 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1969 error (_("Cannot overwrite convenience function %s"), var
->name
);
1971 /* Prepare new contents. */
1972 switch (TYPE_CODE (check_typedef (value_type (val
))))
1974 case TYPE_CODE_VOID
:
1975 new_kind
= INTERNALVAR_VOID
;
1978 case TYPE_CODE_INTERNAL_FUNCTION
:
1979 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1980 new_kind
= INTERNALVAR_FUNCTION
;
1981 get_internalvar_function (VALUE_INTERNALVAR (val
),
1982 &new_data
.fn
.function
);
1983 /* Copies created here are never canonical. */
1987 new_kind
= INTERNALVAR_VALUE
;
1988 new_data
.value
= value_copy (val
);
1989 new_data
.value
->modifiable
= 1;
1991 /* Force the value to be fetched from the target now, to avoid problems
1992 later when this internalvar is referenced and the target is gone or
1994 if (value_lazy (new_data
.value
))
1995 value_fetch_lazy (new_data
.value
);
1997 /* Release the value from the value chain to prevent it from being
1998 deleted by free_all_values. From here on this function should not
1999 call error () until new_data is installed into the var->u to avoid
2001 release_value (new_data
.value
);
2005 /* Clean up old contents. */
2006 clear_internalvar (var
);
2009 var
->kind
= new_kind
;
2011 /* End code which must not call error(). */
2015 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2017 /* Clean up old contents. */
2018 clear_internalvar (var
);
2020 var
->kind
= INTERNALVAR_INTEGER
;
2021 var
->u
.integer
.type
= NULL
;
2022 var
->u
.integer
.val
= l
;
2026 set_internalvar_string (struct internalvar
*var
, const char *string
)
2028 /* Clean up old contents. */
2029 clear_internalvar (var
);
2031 var
->kind
= INTERNALVAR_STRING
;
2032 var
->u
.string
= xstrdup (string
);
2036 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2038 /* Clean up old contents. */
2039 clear_internalvar (var
);
2041 var
->kind
= INTERNALVAR_FUNCTION
;
2042 var
->u
.fn
.function
= f
;
2043 var
->u
.fn
.canonical
= 1;
2044 /* Variables installed here are always the canonical version. */
2048 clear_internalvar (struct internalvar
*var
)
2050 /* Clean up old contents. */
2053 case INTERNALVAR_VALUE
:
2054 value_free (var
->u
.value
);
2057 case INTERNALVAR_STRING
:
2058 xfree (var
->u
.string
);
2061 case INTERNALVAR_MAKE_VALUE
:
2062 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2063 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2070 /* Reset to void kind. */
2071 var
->kind
= INTERNALVAR_VOID
;
2075 internalvar_name (struct internalvar
*var
)
2080 static struct internal_function
*
2081 create_internal_function (const char *name
,
2082 internal_function_fn handler
, void *cookie
)
2084 struct internal_function
*ifn
= XNEW (struct internal_function
);
2086 ifn
->name
= xstrdup (name
);
2087 ifn
->handler
= handler
;
2088 ifn
->cookie
= cookie
;
2093 value_internal_function_name (struct value
*val
)
2095 struct internal_function
*ifn
;
2098 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2099 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2100 gdb_assert (result
);
2106 call_internal_function (struct gdbarch
*gdbarch
,
2107 const struct language_defn
*language
,
2108 struct value
*func
, int argc
, struct value
**argv
)
2110 struct internal_function
*ifn
;
2113 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2114 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2115 gdb_assert (result
);
2117 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2120 /* The 'function' command. This does nothing -- it is just a
2121 placeholder to let "help function NAME" work. This is also used as
2122 the implementation of the sub-command that is created when
2123 registering an internal function. */
2125 function_command (char *command
, int from_tty
)
2130 /* Clean up if an internal function's command is destroyed. */
2132 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2134 xfree ((char *) self
->name
);
2138 /* Add a new internal function. NAME is the name of the function; DOC
2139 is a documentation string describing the function. HANDLER is
2140 called when the function is invoked. COOKIE is an arbitrary
2141 pointer which is passed to HANDLER and is intended for "user
2144 add_internal_function (const char *name
, const char *doc
,
2145 internal_function_fn handler
, void *cookie
)
2147 struct cmd_list_element
*cmd
;
2148 struct internal_function
*ifn
;
2149 struct internalvar
*var
= lookup_internalvar (name
);
2151 ifn
= create_internal_function (name
, handler
, cookie
);
2152 set_internalvar_function (var
, ifn
);
2154 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2156 cmd
->destroyer
= function_destroyer
;
2159 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2160 prevent cycles / duplicates. */
2163 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2164 htab_t copied_types
)
2166 if (TYPE_OBJFILE (value
->type
) == objfile
)
2167 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2169 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2170 value
->enclosing_type
= copy_type_recursive (objfile
,
2171 value
->enclosing_type
,
2175 /* Likewise for internal variable VAR. */
2178 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2179 htab_t copied_types
)
2183 case INTERNALVAR_INTEGER
:
2184 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2186 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2189 case INTERNALVAR_VALUE
:
2190 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2195 /* Update the internal variables and value history when OBJFILE is
2196 discarded; we must copy the types out of the objfile. New global types
2197 will be created for every convenience variable which currently points to
2198 this objfile's types, and the convenience variables will be adjusted to
2199 use the new global types. */
2202 preserve_values (struct objfile
*objfile
)
2204 htab_t copied_types
;
2205 struct value_history_chunk
*cur
;
2206 struct internalvar
*var
;
2209 /* Create the hash table. We allocate on the objfile's obstack, since
2210 it is soon to be deleted. */
2211 copied_types
= create_copied_types_hash (objfile
);
2213 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2214 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2216 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2218 for (var
= internalvars
; var
; var
= var
->next
)
2219 preserve_one_internalvar (var
, objfile
, copied_types
);
2221 preserve_python_values (objfile
, copied_types
);
2223 htab_delete (copied_types
);
2227 show_convenience (char *ignore
, int from_tty
)
2229 struct gdbarch
*gdbarch
= get_current_arch ();
2230 struct internalvar
*var
;
2232 struct value_print_options opts
;
2234 get_user_print_options (&opts
);
2235 for (var
= internalvars
; var
; var
= var
->next
)
2237 volatile struct gdb_exception ex
;
2243 printf_filtered (("$%s = "), var
->name
);
2245 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2249 val
= value_of_internalvar (gdbarch
, var
);
2250 value_print (val
, gdb_stdout
, &opts
);
2253 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2254 printf_filtered (("\n"));
2258 /* This text does not mention convenience functions on purpose.
2259 The user can't create them except via Python, and if Python support
2260 is installed this message will never be printed ($_streq will
2262 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2263 "Convenience variables have "
2264 "names starting with \"$\";\n"
2265 "use \"set\" as in \"set "
2266 "$foo = 5\" to define them.\n"));
2270 /* Extract a value as a C number (either long or double).
2271 Knows how to convert fixed values to double, or
2272 floating values to long.
2273 Does not deallocate the value. */
2276 value_as_long (struct value
*val
)
2278 /* This coerces arrays and functions, which is necessary (e.g.
2279 in disassemble_command). It also dereferences references, which
2280 I suspect is the most logical thing to do. */
2281 val
= coerce_array (val
);
2282 return unpack_long (value_type (val
), value_contents (val
));
2286 value_as_double (struct value
*val
)
2291 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2293 error (_("Invalid floating value found in program."));
2297 /* Extract a value as a C pointer. Does not deallocate the value.
2298 Note that val's type may not actually be a pointer; value_as_long
2299 handles all the cases. */
2301 value_as_address (struct value
*val
)
2303 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2305 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2306 whether we want this to be true eventually. */
2308 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2309 non-address (e.g. argument to "signal", "info break", etc.), or
2310 for pointers to char, in which the low bits *are* significant. */
2311 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2314 /* There are several targets (IA-64, PowerPC, and others) which
2315 don't represent pointers to functions as simply the address of
2316 the function's entry point. For example, on the IA-64, a
2317 function pointer points to a two-word descriptor, generated by
2318 the linker, which contains the function's entry point, and the
2319 value the IA-64 "global pointer" register should have --- to
2320 support position-independent code. The linker generates
2321 descriptors only for those functions whose addresses are taken.
2323 On such targets, it's difficult for GDB to convert an arbitrary
2324 function address into a function pointer; it has to either find
2325 an existing descriptor for that function, or call malloc and
2326 build its own. On some targets, it is impossible for GDB to
2327 build a descriptor at all: the descriptor must contain a jump
2328 instruction; data memory cannot be executed; and code memory
2331 Upon entry to this function, if VAL is a value of type `function'
2332 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2333 value_address (val) is the address of the function. This is what
2334 you'll get if you evaluate an expression like `main'. The call
2335 to COERCE_ARRAY below actually does all the usual unary
2336 conversions, which includes converting values of type `function'
2337 to `pointer to function'. This is the challenging conversion
2338 discussed above. Then, `unpack_long' will convert that pointer
2339 back into an address.
2341 So, suppose the user types `disassemble foo' on an architecture
2342 with a strange function pointer representation, on which GDB
2343 cannot build its own descriptors, and suppose further that `foo'
2344 has no linker-built descriptor. The address->pointer conversion
2345 will signal an error and prevent the command from running, even
2346 though the next step would have been to convert the pointer
2347 directly back into the same address.
2349 The following shortcut avoids this whole mess. If VAL is a
2350 function, just return its address directly. */
2351 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2352 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2353 return value_address (val
);
2355 val
= coerce_array (val
);
2357 /* Some architectures (e.g. Harvard), map instruction and data
2358 addresses onto a single large unified address space. For
2359 instance: An architecture may consider a large integer in the
2360 range 0x10000000 .. 0x1000ffff to already represent a data
2361 addresses (hence not need a pointer to address conversion) while
2362 a small integer would still need to be converted integer to
2363 pointer to address. Just assume such architectures handle all
2364 integer conversions in a single function. */
2368 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2369 must admonish GDB hackers to make sure its behavior matches the
2370 compiler's, whenever possible.
2372 In general, I think GDB should evaluate expressions the same way
2373 the compiler does. When the user copies an expression out of
2374 their source code and hands it to a `print' command, they should
2375 get the same value the compiler would have computed. Any
2376 deviation from this rule can cause major confusion and annoyance,
2377 and needs to be justified carefully. In other words, GDB doesn't
2378 really have the freedom to do these conversions in clever and
2381 AndrewC pointed out that users aren't complaining about how GDB
2382 casts integers to pointers; they are complaining that they can't
2383 take an address from a disassembly listing and give it to `x/i'.
2384 This is certainly important.
2386 Adding an architecture method like integer_to_address() certainly
2387 makes it possible for GDB to "get it right" in all circumstances
2388 --- the target has complete control over how things get done, so
2389 people can Do The Right Thing for their target without breaking
2390 anyone else. The standard doesn't specify how integers get
2391 converted to pointers; usually, the ABI doesn't either, but
2392 ABI-specific code is a more reasonable place to handle it. */
2394 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2395 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2396 && gdbarch_integer_to_address_p (gdbarch
))
2397 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2398 value_contents (val
));
2400 return unpack_long (value_type (val
), value_contents (val
));
2404 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2405 as a long, or as a double, assuming the raw data is described
2406 by type TYPE. Knows how to convert different sizes of values
2407 and can convert between fixed and floating point. We don't assume
2408 any alignment for the raw data. Return value is in host byte order.
2410 If you want functions and arrays to be coerced to pointers, and
2411 references to be dereferenced, call value_as_long() instead.
2413 C++: It is assumed that the front-end has taken care of
2414 all matters concerning pointers to members. A pointer
2415 to member which reaches here is considered to be equivalent
2416 to an INT (or some size). After all, it is only an offset. */
2419 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2421 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2422 enum type_code code
= TYPE_CODE (type
);
2423 int len
= TYPE_LENGTH (type
);
2424 int nosign
= TYPE_UNSIGNED (type
);
2428 case TYPE_CODE_TYPEDEF
:
2429 return unpack_long (check_typedef (type
), valaddr
);
2430 case TYPE_CODE_ENUM
:
2431 case TYPE_CODE_FLAGS
:
2432 case TYPE_CODE_BOOL
:
2434 case TYPE_CODE_CHAR
:
2435 case TYPE_CODE_RANGE
:
2436 case TYPE_CODE_MEMBERPTR
:
2438 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2440 return extract_signed_integer (valaddr
, len
, byte_order
);
2443 return extract_typed_floating (valaddr
, type
);
2445 case TYPE_CODE_DECFLOAT
:
2446 /* libdecnumber has a function to convert from decimal to integer, but
2447 it doesn't work when the decimal number has a fractional part. */
2448 return decimal_to_doublest (valaddr
, len
, byte_order
);
2452 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2453 whether we want this to be true eventually. */
2454 return extract_typed_address (valaddr
, type
);
2457 error (_("Value can't be converted to integer."));
2459 return 0; /* Placate lint. */
2462 /* Return a double value from the specified type and address.
2463 INVP points to an int which is set to 0 for valid value,
2464 1 for invalid value (bad float format). In either case,
2465 the returned double is OK to use. Argument is in target
2466 format, result is in host format. */
2469 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2471 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2472 enum type_code code
;
2476 *invp
= 0; /* Assume valid. */
2477 CHECK_TYPEDEF (type
);
2478 code
= TYPE_CODE (type
);
2479 len
= TYPE_LENGTH (type
);
2480 nosign
= TYPE_UNSIGNED (type
);
2481 if (code
== TYPE_CODE_FLT
)
2483 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2484 floating-point value was valid (using the macro
2485 INVALID_FLOAT). That test/macro have been removed.
2487 It turns out that only the VAX defined this macro and then
2488 only in a non-portable way. Fixing the portability problem
2489 wouldn't help since the VAX floating-point code is also badly
2490 bit-rotten. The target needs to add definitions for the
2491 methods gdbarch_float_format and gdbarch_double_format - these
2492 exactly describe the target floating-point format. The
2493 problem here is that the corresponding floatformat_vax_f and
2494 floatformat_vax_d values these methods should be set to are
2495 also not defined either. Oops!
2497 Hopefully someone will add both the missing floatformat
2498 definitions and the new cases for floatformat_is_valid (). */
2500 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2506 return extract_typed_floating (valaddr
, type
);
2508 else if (code
== TYPE_CODE_DECFLOAT
)
2509 return decimal_to_doublest (valaddr
, len
, byte_order
);
2512 /* Unsigned -- be sure we compensate for signed LONGEST. */
2513 return (ULONGEST
) unpack_long (type
, valaddr
);
2517 /* Signed -- we are OK with unpack_long. */
2518 return unpack_long (type
, valaddr
);
2522 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2523 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2524 We don't assume any alignment for the raw data. Return value is in
2527 If you want functions and arrays to be coerced to pointers, and
2528 references to be dereferenced, call value_as_address() instead.
2530 C++: It is assumed that the front-end has taken care of
2531 all matters concerning pointers to members. A pointer
2532 to member which reaches here is considered to be equivalent
2533 to an INT (or some size). After all, it is only an offset. */
2536 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2538 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2539 whether we want this to be true eventually. */
2540 return unpack_long (type
, valaddr
);
2544 /* Get the value of the FIELDNO'th field (which must be static) of
2545 TYPE. Return NULL if the field doesn't exist or has been
2549 value_static_field (struct type
*type
, int fieldno
)
2551 struct value
*retval
;
2553 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2555 case FIELD_LOC_KIND_PHYSADDR
:
2556 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2557 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2559 case FIELD_LOC_KIND_PHYSNAME
:
2561 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2562 /* TYPE_FIELD_NAME (type, fieldno); */
2563 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2567 /* With some compilers, e.g. HP aCC, static data members are
2568 reported as non-debuggable symbols. */
2569 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2576 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2577 SYMBOL_VALUE_ADDRESS (msym
));
2581 retval
= value_of_variable (sym
, NULL
);
2585 gdb_assert_not_reached ("unexpected field location kind");
2591 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2592 You have to be careful here, since the size of the data area for the value
2593 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2594 than the old enclosing type, you have to allocate more space for the
2598 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2600 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2602 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2604 val
->enclosing_type
= new_encl_type
;
2607 /* Given a value ARG1 (offset by OFFSET bytes)
2608 of a struct or union type ARG_TYPE,
2609 extract and return the value of one of its (non-static) fields.
2610 FIELDNO says which field. */
2613 value_primitive_field (struct value
*arg1
, int offset
,
2614 int fieldno
, struct type
*arg_type
)
2619 CHECK_TYPEDEF (arg_type
);
2620 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2622 /* Call check_typedef on our type to make sure that, if TYPE
2623 is a TYPE_CODE_TYPEDEF, its length is set to the length
2624 of the target type instead of zero. However, we do not
2625 replace the typedef type by the target type, because we want
2626 to keep the typedef in order to be able to print the type
2627 description correctly. */
2628 check_typedef (type
);
2630 if (value_optimized_out (arg1
))
2631 v
= allocate_optimized_out_value (type
);
2632 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2634 /* Handle packed fields.
2636 Create a new value for the bitfield, with bitpos and bitsize
2637 set. If possible, arrange offset and bitpos so that we can
2638 do a single aligned read of the size of the containing type.
2639 Otherwise, adjust offset to the byte containing the first
2640 bit. Assume that the address, offset, and embedded offset
2641 are sufficiently aligned. */
2643 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2644 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2646 v
= allocate_value_lazy (type
);
2647 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2648 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2649 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2650 v
->bitpos
= bitpos
% container_bitsize
;
2652 v
->bitpos
= bitpos
% 8;
2653 v
->offset
= (value_embedded_offset (arg1
)
2655 + (bitpos
- v
->bitpos
) / 8);
2656 set_value_parent (v
, arg1
);
2657 if (!value_lazy (arg1
))
2658 value_fetch_lazy (v
);
2660 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2662 /* This field is actually a base subobject, so preserve the
2663 entire object's contents for later references to virtual
2667 /* Lazy register values with offsets are not supported. */
2668 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2669 value_fetch_lazy (arg1
);
2671 /* We special case virtual inheritance here because this
2672 requires access to the contents, which we would rather avoid
2673 for references to ordinary fields of unavailable values. */
2674 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2675 boffset
= baseclass_offset (arg_type
, fieldno
,
2676 value_contents (arg1
),
2677 value_embedded_offset (arg1
),
2678 value_address (arg1
),
2681 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2683 if (value_lazy (arg1
))
2684 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2687 v
= allocate_value (value_enclosing_type (arg1
));
2688 value_contents_copy_raw (v
, 0, arg1
, 0,
2689 TYPE_LENGTH (value_enclosing_type (arg1
)));
2692 v
->offset
= value_offset (arg1
);
2693 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2697 /* Plain old data member */
2698 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2700 /* Lazy register values with offsets are not supported. */
2701 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2702 value_fetch_lazy (arg1
);
2704 if (value_lazy (arg1
))
2705 v
= allocate_value_lazy (type
);
2708 v
= allocate_value (type
);
2709 value_contents_copy_raw (v
, value_embedded_offset (v
),
2710 arg1
, value_embedded_offset (arg1
) + offset
,
2711 TYPE_LENGTH (type
));
2713 v
->offset
= (value_offset (arg1
) + offset
2714 + value_embedded_offset (arg1
));
2716 set_value_component_location (v
, arg1
);
2717 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2718 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2722 /* Given a value ARG1 of a struct or union type,
2723 extract and return the value of one of its (non-static) fields.
2724 FIELDNO says which field. */
2727 value_field (struct value
*arg1
, int fieldno
)
2729 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2732 /* Return a non-virtual function as a value.
2733 F is the list of member functions which contains the desired method.
2734 J is an index into F which provides the desired method.
2736 We only use the symbol for its address, so be happy with either a
2737 full symbol or a minimal symbol. */
2740 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2741 int j
, struct type
*type
,
2745 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2746 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2748 struct minimal_symbol
*msym
;
2750 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2757 gdb_assert (sym
== NULL
);
2758 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2763 v
= allocate_value (ftype
);
2766 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2770 /* The minimal symbol might point to a function descriptor;
2771 resolve it to the actual code address instead. */
2772 struct objfile
*objfile
= msymbol_objfile (msym
);
2773 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2775 set_value_address (v
,
2776 gdbarch_convert_from_func_ptr_addr
2777 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2782 if (type
!= value_type (*arg1p
))
2783 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2784 value_addr (*arg1p
)));
2786 /* Move the `this' pointer according to the offset.
2787 VALUE_OFFSET (*arg1p) += offset; */
2795 /* Helper function for both unpack_value_bits_as_long and
2796 unpack_bits_as_long. See those functions for more details on the
2797 interface; the only difference is that this function accepts either
2798 a NULL or a non-NULL ORIGINAL_VALUE. */
2801 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2802 int embedded_offset
, int bitpos
, int bitsize
,
2803 const struct value
*original_value
,
2806 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2813 /* Read the minimum number of bytes required; there may not be
2814 enough bytes to read an entire ULONGEST. */
2815 CHECK_TYPEDEF (field_type
);
2817 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2819 bytes_read
= TYPE_LENGTH (field_type
);
2821 read_offset
= bitpos
/ 8;
2823 if (original_value
!= NULL
2824 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2828 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2829 bytes_read
, byte_order
);
2831 /* Extract bits. See comment above. */
2833 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2834 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2836 lsbcount
= (bitpos
% 8);
2839 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2840 If the field is signed, and is negative, then sign extend. */
2842 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2844 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2846 if (!TYPE_UNSIGNED (field_type
))
2848 if (val
& (valmask
^ (valmask
>> 1)))
2859 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2860 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2861 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2862 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2865 Returns false if the value contents are unavailable, otherwise
2866 returns true, indicating a valid value has been stored in *RESULT.
2868 Extracting bits depends on endianness of the machine. Compute the
2869 number of least significant bits to discard. For big endian machines,
2870 we compute the total number of bits in the anonymous object, subtract
2871 off the bit count from the MSB of the object to the MSB of the
2872 bitfield, then the size of the bitfield, which leaves the LSB discard
2873 count. For little endian machines, the discard count is simply the
2874 number of bits from the LSB of the anonymous object to the LSB of the
2877 If the field is signed, we also do sign extension. */
2880 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2881 int embedded_offset
, int bitpos
, int bitsize
,
2882 const struct value
*original_value
,
2885 gdb_assert (original_value
!= NULL
);
2887 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2888 bitpos
, bitsize
, original_value
, result
);
2892 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2893 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2894 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2898 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2899 int embedded_offset
, int fieldno
,
2900 const struct value
*val
, LONGEST
*result
)
2902 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2903 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2904 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2906 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2907 bitpos
, bitsize
, val
,
2911 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2912 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2913 ORIGINAL_VALUE, which must not be NULL. See
2914 unpack_value_bits_as_long for more details. */
2917 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2918 int embedded_offset
, int fieldno
,
2919 const struct value
*val
, LONGEST
*result
)
2921 gdb_assert (val
!= NULL
);
2923 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2924 fieldno
, val
, result
);
2927 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2928 object at VALADDR. See unpack_value_bits_as_long for more details.
2929 This function differs from unpack_value_field_as_long in that it
2930 operates without a struct value object. */
2933 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2937 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2941 /* Return a new value with type TYPE, which is FIELDNO field of the
2942 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2943 of VAL. If the VAL's contents required to extract the bitfield
2944 from are unavailable, the new value is correspondingly marked as
2948 value_field_bitfield (struct type
*type
, int fieldno
,
2949 const gdb_byte
*valaddr
,
2950 int embedded_offset
, const struct value
*val
)
2954 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2957 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2958 struct value
*retval
= allocate_value (field_type
);
2959 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2964 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2968 /* Modify the value of a bitfield. ADDR points to a block of memory in
2969 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2970 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2971 indicate which bits (in target bit order) comprise the bitfield.
2972 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2973 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2976 modify_field (struct type
*type
, gdb_byte
*addr
,
2977 LONGEST fieldval
, int bitpos
, int bitsize
)
2979 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2981 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2984 /* Normalize BITPOS. */
2988 /* If a negative fieldval fits in the field in question, chop
2989 off the sign extension bits. */
2990 if ((~fieldval
& ~(mask
>> 1)) == 0)
2993 /* Warn if value is too big to fit in the field in question. */
2994 if (0 != (fieldval
& ~mask
))
2996 /* FIXME: would like to include fieldval in the message, but
2997 we don't have a sprintf_longest. */
2998 warning (_("Value does not fit in %d bits."), bitsize
);
3000 /* Truncate it, otherwise adjoining fields may be corrupted. */
3004 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3005 false valgrind reports. */
3007 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3008 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3010 /* Shifting for bit field depends on endianness of the target machine. */
3011 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3012 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3014 oword
&= ~(mask
<< bitpos
);
3015 oword
|= fieldval
<< bitpos
;
3017 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3020 /* Pack NUM into BUF using a target format of TYPE. */
3023 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3025 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3028 type
= check_typedef (type
);
3029 len
= TYPE_LENGTH (type
);
3031 switch (TYPE_CODE (type
))
3034 case TYPE_CODE_CHAR
:
3035 case TYPE_CODE_ENUM
:
3036 case TYPE_CODE_FLAGS
:
3037 case TYPE_CODE_BOOL
:
3038 case TYPE_CODE_RANGE
:
3039 case TYPE_CODE_MEMBERPTR
:
3040 store_signed_integer (buf
, len
, byte_order
, num
);
3045 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3049 error (_("Unexpected type (%d) encountered for integer constant."),
3055 /* Pack NUM into BUF using a target format of TYPE. */
3058 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3061 enum bfd_endian byte_order
;
3063 type
= check_typedef (type
);
3064 len
= TYPE_LENGTH (type
);
3065 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3067 switch (TYPE_CODE (type
))
3070 case TYPE_CODE_CHAR
:
3071 case TYPE_CODE_ENUM
:
3072 case TYPE_CODE_FLAGS
:
3073 case TYPE_CODE_BOOL
:
3074 case TYPE_CODE_RANGE
:
3075 case TYPE_CODE_MEMBERPTR
:
3076 store_unsigned_integer (buf
, len
, byte_order
, num
);
3081 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3085 error (_("Unexpected type (%d) encountered "
3086 "for unsigned integer constant."),
3092 /* Convert C numbers into newly allocated values. */
3095 value_from_longest (struct type
*type
, LONGEST num
)
3097 struct value
*val
= allocate_value (type
);
3099 pack_long (value_contents_raw (val
), type
, num
);
3104 /* Convert C unsigned numbers into newly allocated values. */
3107 value_from_ulongest (struct type
*type
, ULONGEST num
)
3109 struct value
*val
= allocate_value (type
);
3111 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3117 /* Create a value representing a pointer of type TYPE to the address
3120 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3122 struct value
*val
= allocate_value (type
);
3124 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3129 /* Create a value of type TYPE whose contents come from VALADDR, if it
3130 is non-null, and whose memory address (in the inferior) is
3134 value_from_contents_and_address (struct type
*type
,
3135 const gdb_byte
*valaddr
,
3140 if (valaddr
== NULL
)
3141 v
= allocate_value_lazy (type
);
3144 v
= allocate_value (type
);
3145 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3147 set_value_address (v
, address
);
3148 VALUE_LVAL (v
) = lval_memory
;
3152 /* Create a value of type TYPE holding the contents CONTENTS.
3153 The new value is `not_lval'. */
3156 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3158 struct value
*result
;
3160 result
= allocate_value (type
);
3161 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3166 value_from_double (struct type
*type
, DOUBLEST num
)
3168 struct value
*val
= allocate_value (type
);
3169 struct type
*base_type
= check_typedef (type
);
3170 enum type_code code
= TYPE_CODE (base_type
);
3172 if (code
== TYPE_CODE_FLT
)
3174 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3177 error (_("Unexpected type encountered for floating constant."));
3183 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3185 struct value
*val
= allocate_value (type
);
3187 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3191 /* Extract a value from the history file. Input will be of the form
3192 $digits or $$digits. See block comment above 'write_dollar_variable'
3196 value_from_history_ref (char *h
, char **endp
)
3208 /* Find length of numeral string. */
3209 for (; isdigit (h
[len
]); len
++)
3212 /* Make sure numeral string is not part of an identifier. */
3213 if (h
[len
] == '_' || isalpha (h
[len
]))
3216 /* Now collect the index value. */
3221 /* For some bizarre reason, "$$" is equivalent to "$$1",
3222 rather than to "$$0" as it ought to be! */
3227 index
= -strtol (&h
[2], endp
, 10);
3233 /* "$" is equivalent to "$0". */
3238 index
= strtol (&h
[1], endp
, 10);
3241 return access_value_history (index
);
3245 coerce_ref_if_computed (const struct value
*arg
)
3247 const struct lval_funcs
*funcs
;
3249 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3252 if (value_lval_const (arg
) != lval_computed
)
3255 funcs
= value_computed_funcs (arg
);
3256 if (funcs
->coerce_ref
== NULL
)
3259 return funcs
->coerce_ref (arg
);
3262 /* Look at value.h for description. */
3265 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3266 struct type
*original_type
,
3267 struct value
*original_value
)
3269 /* Re-adjust type. */
3270 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3272 /* Add embedding info. */
3273 set_value_enclosing_type (value
, enc_type
);
3274 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3276 /* We may be pointing to an object of some derived type. */
3277 return value_full_object (value
, NULL
, 0, 0, 0);
3281 coerce_ref (struct value
*arg
)
3283 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3284 struct value
*retval
;
3285 struct type
*enc_type
;
3287 retval
= coerce_ref_if_computed (arg
);
3291 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3294 enc_type
= check_typedef (value_enclosing_type (arg
));
3295 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3297 retval
= value_at_lazy (enc_type
,
3298 unpack_pointer (value_type (arg
),
3299 value_contents (arg
)));
3300 return readjust_indirect_value_type (retval
, enc_type
,
3301 value_type_arg_tmp
, arg
);
3305 coerce_array (struct value
*arg
)
3309 arg
= coerce_ref (arg
);
3310 type
= check_typedef (value_type (arg
));
3312 switch (TYPE_CODE (type
))
3314 case TYPE_CODE_ARRAY
:
3315 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3316 arg
= value_coerce_array (arg
);
3318 case TYPE_CODE_FUNC
:
3319 arg
= value_coerce_function (arg
);
3326 /* Return the return value convention that will be used for the
3329 enum return_value_convention
3330 struct_return_convention (struct gdbarch
*gdbarch
,
3331 struct value
*function
, struct type
*value_type
)
3333 enum type_code code
= TYPE_CODE (value_type
);
3335 if (code
== TYPE_CODE_ERROR
)
3336 error (_("Function return type unknown."));
3338 /* Probe the architecture for the return-value convention. */
3339 return gdbarch_return_value (gdbarch
, function
, value_type
,
3343 /* Return true if the function returning the specified type is using
3344 the convention of returning structures in memory (passing in the
3345 address as a hidden first parameter). */
3348 using_struct_return (struct gdbarch
*gdbarch
,
3349 struct value
*function
, struct type
*value_type
)
3351 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3352 /* A void return value is never in memory. See also corresponding
3353 code in "print_return_value". */
3356 return (struct_return_convention (gdbarch
, function
, value_type
)
3357 != RETURN_VALUE_REGISTER_CONVENTION
);
3360 /* Set the initialized field in a value struct. */
3363 set_value_initialized (struct value
*val
, int status
)
3365 val
->initialized
= status
;
3368 /* Return the initialized field in a value struct. */
3371 value_initialized (struct value
*val
)
3373 return val
->initialized
;
3377 _initialize_values (void)
3379 add_cmd ("convenience", no_class
, show_convenience
, _("\
3380 Debugger convenience (\"$foo\") variables and functions.\n\
3381 Convenience variables are created when you assign them values;\n\
3382 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3384 A few convenience variables are given values automatically:\n\
3385 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3386 \"$__\" holds the contents of the last address examined with \"x\"."
3389 Convenience functions are defined via the Python API."
3392 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3394 add_cmd ("values", no_set_class
, show_values
, _("\
3395 Elements of value history around item number IDX (or last ten)."),
3398 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3399 Initialize a convenience variable if necessary.\n\
3400 init-if-undefined VARIABLE = EXPRESSION\n\
3401 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3402 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3403 VARIABLE is already initialized."));
3405 add_prefix_cmd ("function", no_class
, function_command
, _("\
3406 Placeholder command for showing help on convenience functions."),
3407 &functionlist
, "function ", 0, &cmdlist
);