1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2000, 2002-2012 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 /* This routine is used by printing routines, where we should
547 already have read the value. Note that we only know whether a
548 value chunk is available if we've tried to read it. */
549 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
557 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
559 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
562 /* The usual case is for both values to be completely available. */
563 if (idx1
== -1 && idx2
== -1)
564 return (memcmp (val1
->contents
+ offset1
,
565 val2
->contents
+ offset2
,
567 /* The contents only match equal if the available set matches as
569 else if (idx1
== -1 || idx2
== -1)
572 gdb_assert (idx1
!= -1 && idx2
!= -1);
574 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
575 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
577 /* Get the unavailable windows intersected by the incoming
578 ranges. The first and last ranges that overlap the argument
579 range may be wider than said incoming arguments ranges. */
580 l1
= max (offset1
, r1
->offset
);
581 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
583 l2
= max (offset2
, r2
->offset
);
584 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
586 /* Make them relative to the respective start offsets, so we can
587 compare them for equality. */
594 /* Different availability, no match. */
595 if (l1
!= l2
|| h1
!= h2
)
598 /* Compare the _available_ contents. */
599 if (memcmp (val1
->contents
+ offset1
,
600 val2
->contents
+ offset2
,
612 /* Prototypes for local functions. */
614 static void show_values (char *, int);
616 static void show_convenience (char *, int);
619 /* The value-history records all the values printed
620 by print commands during this session. Each chunk
621 records 60 consecutive values. The first chunk on
622 the chain records the most recent values.
623 The total number of values is in value_history_count. */
625 #define VALUE_HISTORY_CHUNK 60
627 struct value_history_chunk
629 struct value_history_chunk
*next
;
630 struct value
*values
[VALUE_HISTORY_CHUNK
];
633 /* Chain of chunks now in use. */
635 static struct value_history_chunk
*value_history_chain
;
637 static int value_history_count
; /* Abs number of last entry stored. */
640 /* List of all value objects currently allocated
641 (except for those released by calls to release_value)
642 This is so they can be freed after each command. */
644 static struct value
*all_values
;
646 /* Allocate a lazy value for type TYPE. Its actual content is
647 "lazily" allocated too: the content field of the return value is
648 NULL; it will be allocated when it is fetched from the target. */
651 allocate_value_lazy (struct type
*type
)
655 /* Call check_typedef on our type to make sure that, if TYPE
656 is a TYPE_CODE_TYPEDEF, its length is set to the length
657 of the target type instead of zero. However, we do not
658 replace the typedef type by the target type, because we want
659 to keep the typedef in order to be able to set the VAL's type
660 description correctly. */
661 check_typedef (type
);
663 val
= (struct value
*) xzalloc (sizeof (struct value
));
664 val
->contents
= NULL
;
665 val
->next
= all_values
;
668 val
->enclosing_type
= type
;
669 VALUE_LVAL (val
) = not_lval
;
670 val
->location
.address
= 0;
671 VALUE_FRAME_ID (val
) = null_frame_id
;
675 VALUE_REGNUM (val
) = -1;
677 val
->optimized_out
= 0;
678 val
->embedded_offset
= 0;
679 val
->pointed_to_offset
= 0;
681 val
->initialized
= 1; /* Default to initialized. */
683 /* Values start out on the all_values chain. */
684 val
->reference_count
= 1;
689 /* Allocate the contents of VAL if it has not been allocated yet. */
692 allocate_value_contents (struct value
*val
)
695 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
698 /* Allocate a value and its contents for type TYPE. */
701 allocate_value (struct type
*type
)
703 struct value
*val
= allocate_value_lazy (type
);
705 allocate_value_contents (val
);
710 /* Allocate a value that has the correct length
711 for COUNT repetitions of type TYPE. */
714 allocate_repeat_value (struct type
*type
, int count
)
716 int low_bound
= current_language
->string_lower_bound
; /* ??? */
717 /* FIXME-type-allocation: need a way to free this type when we are
719 struct type
*array_type
720 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
722 return allocate_value (array_type
);
726 allocate_computed_value (struct type
*type
,
727 const struct lval_funcs
*funcs
,
730 struct value
*v
= allocate_value_lazy (type
);
732 VALUE_LVAL (v
) = lval_computed
;
733 v
->location
.computed
.funcs
= funcs
;
734 v
->location
.computed
.closure
= closure
;
739 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
742 allocate_optimized_out_value (struct type
*type
)
744 struct value
*retval
= allocate_value_lazy (type
);
746 set_value_optimized_out (retval
, 1);
751 /* Accessor methods. */
754 value_next (struct value
*value
)
760 value_type (const struct value
*value
)
765 deprecated_set_value_type (struct value
*value
, struct type
*type
)
771 value_offset (const struct value
*value
)
773 return value
->offset
;
776 set_value_offset (struct value
*value
, int offset
)
778 value
->offset
= offset
;
782 value_bitpos (const struct value
*value
)
784 return value
->bitpos
;
787 set_value_bitpos (struct value
*value
, int bit
)
793 value_bitsize (const struct value
*value
)
795 return value
->bitsize
;
798 set_value_bitsize (struct value
*value
, int bit
)
800 value
->bitsize
= bit
;
804 value_parent (struct value
*value
)
806 return value
->parent
;
812 set_value_parent (struct value
*value
, struct value
*parent
)
814 value
->parent
= parent
;
818 value_contents_raw (struct value
*value
)
820 allocate_value_contents (value
);
821 return value
->contents
+ value
->embedded_offset
;
825 value_contents_all_raw (struct value
*value
)
827 allocate_value_contents (value
);
828 return value
->contents
;
832 value_enclosing_type (struct value
*value
)
834 return value
->enclosing_type
;
837 /* Look at value.h for description. */
840 value_actual_type (struct value
*value
, int resolve_simple_types
,
841 int *real_type_found
)
843 struct value_print_options opts
;
846 get_user_print_options (&opts
);
849 *real_type_found
= 0;
850 result
= value_type (value
);
851 if (opts
.objectprint
)
853 if (TYPE_CODE (result
) == TYPE_CODE_PTR
854 || TYPE_CODE (result
) == TYPE_CODE_REF
)
856 struct type
*real_type
;
858 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
862 *real_type_found
= 1;
866 else if (resolve_simple_types
)
869 *real_type_found
= 1;
870 result
= value_enclosing_type (value
);
878 require_not_optimized_out (const struct value
*value
)
880 if (value
->optimized_out
)
881 error (_("value has been optimized out"));
885 require_available (const struct value
*value
)
887 if (!VEC_empty (range_s
, value
->unavailable
))
888 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
892 value_contents_for_printing (struct value
*value
)
895 value_fetch_lazy (value
);
896 return value
->contents
;
900 value_contents_for_printing_const (const struct value
*value
)
902 gdb_assert (!value
->lazy
);
903 return value
->contents
;
907 value_contents_all (struct value
*value
)
909 const gdb_byte
*result
= value_contents_for_printing (value
);
910 require_not_optimized_out (value
);
911 require_available (value
);
915 /* Copy LENGTH bytes of SRC value's (all) contents
916 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
917 contents, starting at DST_OFFSET. If unavailable contents are
918 being copied from SRC, the corresponding DST contents are marked
919 unavailable accordingly. Neither DST nor SRC may be lazy
922 It is assumed the contents of DST in the [DST_OFFSET,
923 DST_OFFSET+LENGTH) range are wholly available. */
926 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
927 struct value
*src
, int src_offset
, int length
)
932 /* A lazy DST would make that this copy operation useless, since as
933 soon as DST's contents were un-lazied (by a later value_contents
934 call, say), the contents would be overwritten. A lazy SRC would
935 mean we'd be copying garbage. */
936 gdb_assert (!dst
->lazy
&& !src
->lazy
);
938 /* The overwritten DST range gets unavailability ORed in, not
939 replaced. Make sure to remember to implement replacing if it
940 turns out actually necessary. */
941 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
944 memcpy (value_contents_all_raw (dst
) + dst_offset
,
945 value_contents_all_raw (src
) + src_offset
,
948 /* Copy the meta-data, adjusted. */
949 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
953 l
= max (r
->offset
, src_offset
);
954 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
957 mark_value_bytes_unavailable (dst
,
958 dst_offset
+ (l
- src_offset
),
963 /* Copy LENGTH bytes of SRC value's (all) contents
964 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
965 (all) contents, starting at DST_OFFSET. If unavailable contents
966 are being copied from SRC, the corresponding DST contents are
967 marked unavailable accordingly. DST must not be lazy. If SRC is
968 lazy, it will be fetched now. If SRC is not valid (is optimized
969 out), an error is thrown.
971 It is assumed the contents of DST in the [DST_OFFSET,
972 DST_OFFSET+LENGTH) range are wholly available. */
975 value_contents_copy (struct value
*dst
, int dst_offset
,
976 struct value
*src
, int src_offset
, int length
)
978 require_not_optimized_out (src
);
981 value_fetch_lazy (src
);
983 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
987 value_lazy (struct value
*value
)
993 set_value_lazy (struct value
*value
, int val
)
999 value_stack (struct value
*value
)
1001 return value
->stack
;
1005 set_value_stack (struct value
*value
, int val
)
1011 value_contents (struct value
*value
)
1013 const gdb_byte
*result
= value_contents_writeable (value
);
1014 require_not_optimized_out (value
);
1015 require_available (value
);
1020 value_contents_writeable (struct value
*value
)
1023 value_fetch_lazy (value
);
1024 return value_contents_raw (value
);
1027 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1028 this function is different from value_equal; in C the operator ==
1029 can return 0 even if the two values being compared are equal. */
1032 value_contents_equal (struct value
*val1
, struct value
*val2
)
1037 type1
= check_typedef (value_type (val1
));
1038 type2
= check_typedef (value_type (val2
));
1039 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1042 return (memcmp (value_contents (val1
), value_contents (val2
),
1043 TYPE_LENGTH (type1
)) == 0);
1047 value_optimized_out (struct value
*value
)
1049 return value
->optimized_out
;
1053 set_value_optimized_out (struct value
*value
, int val
)
1055 value
->optimized_out
= val
;
1059 value_entirely_optimized_out (const struct value
*value
)
1061 if (!value
->optimized_out
)
1063 if (value
->lval
!= lval_computed
1064 || !value
->location
.computed
.funcs
->check_any_valid
)
1066 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1070 value_bits_valid (const struct value
*value
, int offset
, int length
)
1072 if (!value
->optimized_out
)
1074 if (value
->lval
!= lval_computed
1075 || !value
->location
.computed
.funcs
->check_validity
)
1077 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1082 value_bits_synthetic_pointer (const struct value
*value
,
1083 int offset
, int length
)
1085 if (value
->lval
!= lval_computed
1086 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1088 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1094 value_embedded_offset (struct value
*value
)
1096 return value
->embedded_offset
;
1100 set_value_embedded_offset (struct value
*value
, int val
)
1102 value
->embedded_offset
= val
;
1106 value_pointed_to_offset (struct value
*value
)
1108 return value
->pointed_to_offset
;
1112 set_value_pointed_to_offset (struct value
*value
, int val
)
1114 value
->pointed_to_offset
= val
;
1117 const struct lval_funcs
*
1118 value_computed_funcs (const struct value
*v
)
1120 gdb_assert (value_lval_const (v
) == lval_computed
);
1122 return v
->location
.computed
.funcs
;
1126 value_computed_closure (const struct value
*v
)
1128 gdb_assert (v
->lval
== lval_computed
);
1130 return v
->location
.computed
.closure
;
1134 deprecated_value_lval_hack (struct value
*value
)
1136 return &value
->lval
;
1140 value_lval_const (const struct value
*value
)
1146 value_address (const struct value
*value
)
1148 if (value
->lval
== lval_internalvar
1149 || value
->lval
== lval_internalvar_component
)
1151 if (value
->parent
!= NULL
)
1152 return value_address (value
->parent
) + value
->offset
;
1154 return value
->location
.address
+ value
->offset
;
1158 value_raw_address (struct value
*value
)
1160 if (value
->lval
== lval_internalvar
1161 || value
->lval
== lval_internalvar_component
)
1163 return value
->location
.address
;
1167 set_value_address (struct value
*value
, CORE_ADDR addr
)
1169 gdb_assert (value
->lval
!= lval_internalvar
1170 && value
->lval
!= lval_internalvar_component
);
1171 value
->location
.address
= addr
;
1174 struct internalvar
**
1175 deprecated_value_internalvar_hack (struct value
*value
)
1177 return &value
->location
.internalvar
;
1181 deprecated_value_frame_id_hack (struct value
*value
)
1183 return &value
->frame_id
;
1187 deprecated_value_regnum_hack (struct value
*value
)
1189 return &value
->regnum
;
1193 deprecated_value_modifiable (struct value
*value
)
1195 return value
->modifiable
;
1198 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1200 value
->modifiable
= modifiable
;
1203 /* Return a mark in the value chain. All values allocated after the
1204 mark is obtained (except for those released) are subject to being freed
1205 if a subsequent value_free_to_mark is passed the mark. */
1212 /* Take a reference to VAL. VAL will not be deallocated until all
1213 references are released. */
1216 value_incref (struct value
*val
)
1218 val
->reference_count
++;
1221 /* Release a reference to VAL, which was acquired with value_incref.
1222 This function is also called to deallocate values from the value
1226 value_free (struct value
*val
)
1230 gdb_assert (val
->reference_count
> 0);
1231 val
->reference_count
--;
1232 if (val
->reference_count
> 0)
1235 /* If there's an associated parent value, drop our reference to
1237 if (val
->parent
!= NULL
)
1238 value_free (val
->parent
);
1240 if (VALUE_LVAL (val
) == lval_computed
)
1242 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1244 if (funcs
->free_closure
)
1245 funcs
->free_closure (val
);
1248 xfree (val
->contents
);
1249 VEC_free (range_s
, val
->unavailable
);
1254 /* Free all values allocated since MARK was obtained by value_mark
1255 (except for those released). */
1257 value_free_to_mark (struct value
*mark
)
1262 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1271 /* Free all the values that have been allocated (except for those released).
1272 Call after each command, successful or not.
1273 In practice this is called before each command, which is sufficient. */
1276 free_all_values (void)
1281 for (val
= all_values
; val
; val
= next
)
1291 /* Frees all the elements in a chain of values. */
1294 free_value_chain (struct value
*v
)
1300 next
= value_next (v
);
1305 /* Remove VAL from the chain all_values
1306 so it will not be freed automatically. */
1309 release_value (struct value
*val
)
1313 if (all_values
== val
)
1315 all_values
= val
->next
;
1321 for (v
= all_values
; v
; v
= v
->next
)
1325 v
->next
= val
->next
;
1333 /* If the value is not already released, release it.
1334 If the value is already released, increment its reference count.
1335 That is, this function ensures that the value is released from the
1336 value chain and that the caller owns a reference to it. */
1339 release_value_or_incref (struct value
*val
)
1344 release_value (val
);
1347 /* Release all values up to mark */
1349 value_release_to_mark (struct value
*mark
)
1354 for (val
= next
= all_values
; next
; next
= next
->next
)
1356 if (next
->next
== mark
)
1358 all_values
= next
->next
;
1368 /* Return a copy of the value ARG.
1369 It contains the same contents, for same memory address,
1370 but it's a different block of storage. */
1373 value_copy (struct value
*arg
)
1375 struct type
*encl_type
= value_enclosing_type (arg
);
1378 if (value_lazy (arg
))
1379 val
= allocate_value_lazy (encl_type
);
1381 val
= allocate_value (encl_type
);
1382 val
->type
= arg
->type
;
1383 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1384 val
->location
= arg
->location
;
1385 val
->offset
= arg
->offset
;
1386 val
->bitpos
= arg
->bitpos
;
1387 val
->bitsize
= arg
->bitsize
;
1388 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1389 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1390 val
->lazy
= arg
->lazy
;
1391 val
->optimized_out
= arg
->optimized_out
;
1392 val
->embedded_offset
= value_embedded_offset (arg
);
1393 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1394 val
->modifiable
= arg
->modifiable
;
1395 if (!value_lazy (val
))
1397 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1398 TYPE_LENGTH (value_enclosing_type (arg
)));
1401 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1402 val
->parent
= arg
->parent
;
1404 value_incref (val
->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
)
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);
2657 value_incref (v
->parent
);
2658 if (!value_lazy (arg1
))
2659 value_fetch_lazy (v
);
2661 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2663 /* This field is actually a base subobject, so preserve the
2664 entire object's contents for later references to virtual
2668 /* Lazy register values with offsets are not supported. */
2669 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2670 value_fetch_lazy (arg1
);
2672 /* We special case virtual inheritance here because this
2673 requires access to the contents, which we would rather avoid
2674 for references to ordinary fields of unavailable values. */
2675 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2676 boffset
= baseclass_offset (arg_type
, fieldno
,
2677 value_contents (arg1
),
2678 value_embedded_offset (arg1
),
2679 value_address (arg1
),
2682 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2684 if (value_lazy (arg1
))
2685 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2688 v
= allocate_value (value_enclosing_type (arg1
));
2689 value_contents_copy_raw (v
, 0, arg1
, 0,
2690 TYPE_LENGTH (value_enclosing_type (arg1
)));
2693 v
->offset
= value_offset (arg1
);
2694 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2698 /* Plain old data member */
2699 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2701 /* Lazy register values with offsets are not supported. */
2702 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2703 value_fetch_lazy (arg1
);
2705 if (value_lazy (arg1
))
2706 v
= allocate_value_lazy (type
);
2709 v
= allocate_value (type
);
2710 value_contents_copy_raw (v
, value_embedded_offset (v
),
2711 arg1
, value_embedded_offset (arg1
) + offset
,
2712 TYPE_LENGTH (type
));
2714 v
->offset
= (value_offset (arg1
) + offset
2715 + value_embedded_offset (arg1
));
2717 set_value_component_location (v
, arg1
);
2718 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2719 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2723 /* Given a value ARG1 of a struct or union type,
2724 extract and return the value of one of its (non-static) fields.
2725 FIELDNO says which field. */
2728 value_field (struct value
*arg1
, int fieldno
)
2730 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2733 /* Return a non-virtual function as a value.
2734 F is the list of member functions which contains the desired method.
2735 J is an index into F which provides the desired method.
2737 We only use the symbol for its address, so be happy with either a
2738 full symbol or a minimal symbol. */
2741 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2742 int j
, struct type
*type
,
2746 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2747 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2749 struct minimal_symbol
*msym
;
2751 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2758 gdb_assert (sym
== NULL
);
2759 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2764 v
= allocate_value (ftype
);
2767 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2771 /* The minimal symbol might point to a function descriptor;
2772 resolve it to the actual code address instead. */
2773 struct objfile
*objfile
= msymbol_objfile (msym
);
2774 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2776 set_value_address (v
,
2777 gdbarch_convert_from_func_ptr_addr
2778 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2783 if (type
!= value_type (*arg1p
))
2784 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2785 value_addr (*arg1p
)));
2787 /* Move the `this' pointer according to the offset.
2788 VALUE_OFFSET (*arg1p) += offset; */
2796 /* Helper function for both unpack_value_bits_as_long and
2797 unpack_bits_as_long. See those functions for more details on the
2798 interface; the only difference is that this function accepts either
2799 a NULL or a non-NULL ORIGINAL_VALUE. */
2802 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2803 int embedded_offset
, int bitpos
, int bitsize
,
2804 const struct value
*original_value
,
2807 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2814 /* Read the minimum number of bytes required; there may not be
2815 enough bytes to read an entire ULONGEST. */
2816 CHECK_TYPEDEF (field_type
);
2818 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2820 bytes_read
= TYPE_LENGTH (field_type
);
2822 read_offset
= bitpos
/ 8;
2824 if (original_value
!= NULL
2825 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2829 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2830 bytes_read
, byte_order
);
2832 /* Extract bits. See comment above. */
2834 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2835 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2837 lsbcount
= (bitpos
% 8);
2840 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2841 If the field is signed, and is negative, then sign extend. */
2843 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2845 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2847 if (!TYPE_UNSIGNED (field_type
))
2849 if (val
& (valmask
^ (valmask
>> 1)))
2860 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2861 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2862 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2863 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2866 Returns false if the value contents are unavailable, otherwise
2867 returns true, indicating a valid value has been stored in *RESULT.
2869 Extracting bits depends on endianness of the machine. Compute the
2870 number of least significant bits to discard. For big endian machines,
2871 we compute the total number of bits in the anonymous object, subtract
2872 off the bit count from the MSB of the object to the MSB of the
2873 bitfield, then the size of the bitfield, which leaves the LSB discard
2874 count. For little endian machines, the discard count is simply the
2875 number of bits from the LSB of the anonymous object to the LSB of the
2878 If the field is signed, we also do sign extension. */
2881 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2882 int embedded_offset
, int bitpos
, int bitsize
,
2883 const struct value
*original_value
,
2886 gdb_assert (original_value
!= NULL
);
2888 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2889 bitpos
, bitsize
, original_value
, result
);
2893 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2894 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2895 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2899 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2900 int embedded_offset
, int fieldno
,
2901 const struct value
*val
, LONGEST
*result
)
2903 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2904 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2905 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2907 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2908 bitpos
, bitsize
, val
,
2912 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2913 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2914 ORIGINAL_VALUE, which must not be NULL. See
2915 unpack_value_bits_as_long for more details. */
2918 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2919 int embedded_offset
, int fieldno
,
2920 const struct value
*val
, LONGEST
*result
)
2922 gdb_assert (val
!= NULL
);
2924 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2925 fieldno
, val
, result
);
2928 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2929 object at VALADDR. See unpack_value_bits_as_long for more details.
2930 This function differs from unpack_value_field_as_long in that it
2931 operates without a struct value object. */
2934 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2938 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2942 /* Return a new value with type TYPE, which is FIELDNO field of the
2943 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2944 of VAL. If the VAL's contents required to extract the bitfield
2945 from are unavailable, the new value is correspondingly marked as
2949 value_field_bitfield (struct type
*type
, int fieldno
,
2950 const gdb_byte
*valaddr
,
2951 int embedded_offset
, const struct value
*val
)
2955 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2958 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2959 struct value
*retval
= allocate_value (field_type
);
2960 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2965 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2969 /* Modify the value of a bitfield. ADDR points to a block of memory in
2970 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2971 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2972 indicate which bits (in target bit order) comprise the bitfield.
2973 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2974 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2977 modify_field (struct type
*type
, gdb_byte
*addr
,
2978 LONGEST fieldval
, int bitpos
, int bitsize
)
2980 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2982 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2985 /* Normalize BITPOS. */
2989 /* If a negative fieldval fits in the field in question, chop
2990 off the sign extension bits. */
2991 if ((~fieldval
& ~(mask
>> 1)) == 0)
2994 /* Warn if value is too big to fit in the field in question. */
2995 if (0 != (fieldval
& ~mask
))
2997 /* FIXME: would like to include fieldval in the message, but
2998 we don't have a sprintf_longest. */
2999 warning (_("Value does not fit in %d bits."), bitsize
);
3001 /* Truncate it, otherwise adjoining fields may be corrupted. */
3005 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3006 false valgrind reports. */
3008 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3009 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3011 /* Shifting for bit field depends on endianness of the target machine. */
3012 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3013 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3015 oword
&= ~(mask
<< bitpos
);
3016 oword
|= fieldval
<< bitpos
;
3018 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3021 /* Pack NUM into BUF using a target format of TYPE. */
3024 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3026 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3029 type
= check_typedef (type
);
3030 len
= TYPE_LENGTH (type
);
3032 switch (TYPE_CODE (type
))
3035 case TYPE_CODE_CHAR
:
3036 case TYPE_CODE_ENUM
:
3037 case TYPE_CODE_FLAGS
:
3038 case TYPE_CODE_BOOL
:
3039 case TYPE_CODE_RANGE
:
3040 case TYPE_CODE_MEMBERPTR
:
3041 store_signed_integer (buf
, len
, byte_order
, num
);
3046 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3050 error (_("Unexpected type (%d) encountered for integer constant."),
3056 /* Pack NUM into BUF using a target format of TYPE. */
3059 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3062 enum bfd_endian byte_order
;
3064 type
= check_typedef (type
);
3065 len
= TYPE_LENGTH (type
);
3066 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3068 switch (TYPE_CODE (type
))
3071 case TYPE_CODE_CHAR
:
3072 case TYPE_CODE_ENUM
:
3073 case TYPE_CODE_FLAGS
:
3074 case TYPE_CODE_BOOL
:
3075 case TYPE_CODE_RANGE
:
3076 case TYPE_CODE_MEMBERPTR
:
3077 store_unsigned_integer (buf
, len
, byte_order
, num
);
3082 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3086 error (_("Unexpected type (%d) encountered "
3087 "for unsigned integer constant."),
3093 /* Convert C numbers into newly allocated values. */
3096 value_from_longest (struct type
*type
, LONGEST num
)
3098 struct value
*val
= allocate_value (type
);
3100 pack_long (value_contents_raw (val
), type
, num
);
3105 /* Convert C unsigned numbers into newly allocated values. */
3108 value_from_ulongest (struct type
*type
, ULONGEST num
)
3110 struct value
*val
= allocate_value (type
);
3112 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3118 /* Create a value representing a pointer of type TYPE to the address
3121 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3123 struct value
*val
= allocate_value (type
);
3125 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3130 /* Create a value of type TYPE whose contents come from VALADDR, if it
3131 is non-null, and whose memory address (in the inferior) is
3135 value_from_contents_and_address (struct type
*type
,
3136 const gdb_byte
*valaddr
,
3141 if (valaddr
== NULL
)
3142 v
= allocate_value_lazy (type
);
3145 v
= allocate_value (type
);
3146 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3148 set_value_address (v
, address
);
3149 VALUE_LVAL (v
) = lval_memory
;
3153 /* Create a value of type TYPE holding the contents CONTENTS.
3154 The new value is `not_lval'. */
3157 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3159 struct value
*result
;
3161 result
= allocate_value (type
);
3162 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3167 value_from_double (struct type
*type
, DOUBLEST num
)
3169 struct value
*val
= allocate_value (type
);
3170 struct type
*base_type
= check_typedef (type
);
3171 enum type_code code
= TYPE_CODE (base_type
);
3173 if (code
== TYPE_CODE_FLT
)
3175 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3178 error (_("Unexpected type encountered for floating constant."));
3184 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3186 struct value
*val
= allocate_value (type
);
3188 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3192 /* Extract a value from the history file. Input will be of the form
3193 $digits or $$digits. See block comment above 'write_dollar_variable'
3197 value_from_history_ref (char *h
, char **endp
)
3209 /* Find length of numeral string. */
3210 for (; isdigit (h
[len
]); len
++)
3213 /* Make sure numeral string is not part of an identifier. */
3214 if (h
[len
] == '_' || isalpha (h
[len
]))
3217 /* Now collect the index value. */
3222 /* For some bizarre reason, "$$" is equivalent to "$$1",
3223 rather than to "$$0" as it ought to be! */
3228 index
= -strtol (&h
[2], endp
, 10);
3234 /* "$" is equivalent to "$0". */
3239 index
= strtol (&h
[1], endp
, 10);
3242 return access_value_history (index
);
3246 coerce_ref_if_computed (const struct value
*arg
)
3248 const struct lval_funcs
*funcs
;
3250 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3253 if (value_lval_const (arg
) != lval_computed
)
3256 funcs
= value_computed_funcs (arg
);
3257 if (funcs
->coerce_ref
== NULL
)
3260 return funcs
->coerce_ref (arg
);
3263 /* Look at value.h for description. */
3266 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3267 struct type
*original_type
,
3268 struct value
*original_value
)
3270 /* Re-adjust type. */
3271 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3273 /* Add embedding info. */
3274 set_value_enclosing_type (value
, enc_type
);
3275 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3277 /* We may be pointing to an object of some derived type. */
3278 return value_full_object (value
, NULL
, 0, 0, 0);
3282 coerce_ref (struct value
*arg
)
3284 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3285 struct value
*retval
;
3286 struct type
*enc_type
;
3288 retval
= coerce_ref_if_computed (arg
);
3292 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3295 enc_type
= check_typedef (value_enclosing_type (arg
));
3296 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3298 retval
= value_at_lazy (enc_type
,
3299 unpack_pointer (value_type (arg
),
3300 value_contents (arg
)));
3301 return readjust_indirect_value_type (retval
, enc_type
,
3302 value_type_arg_tmp
, arg
);
3306 coerce_array (struct value
*arg
)
3310 arg
= coerce_ref (arg
);
3311 type
= check_typedef (value_type (arg
));
3313 switch (TYPE_CODE (type
))
3315 case TYPE_CODE_ARRAY
:
3316 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3317 arg
= value_coerce_array (arg
);
3319 case TYPE_CODE_FUNC
:
3320 arg
= value_coerce_function (arg
);
3327 /* Return true if the function returning the specified type is using
3328 the convention of returning structures in memory (passing in the
3329 address as a hidden first parameter). */
3332 using_struct_return (struct gdbarch
*gdbarch
,
3333 struct value
*function
, struct type
*value_type
)
3335 enum type_code code
= TYPE_CODE (value_type
);
3337 if (code
== TYPE_CODE_ERROR
)
3338 error (_("Function return type unknown."));
3340 if (code
== TYPE_CODE_VOID
)
3341 /* A void return value is never in memory. See also corresponding
3342 code in "print_return_value". */
3345 /* Probe the architecture for the return-value convention. */
3346 return (gdbarch_return_value (gdbarch
, function
, value_type
,
3348 != RETURN_VALUE_REGISTER_CONVENTION
);
3351 /* Set the initialized field in a value struct. */
3354 set_value_initialized (struct value
*val
, int status
)
3356 val
->initialized
= status
;
3359 /* Return the initialized field in a value struct. */
3362 value_initialized (struct value
*val
)
3364 return val
->initialized
;
3368 _initialize_values (void)
3370 add_cmd ("convenience", no_class
, show_convenience
, _("\
3371 Debugger convenience (\"$foo\") variables and functions.\n\
3372 Convenience variables are created when you assign them values;\n\
3373 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3375 A few convenience variables are given values automatically:\n\
3376 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3377 \"$__\" holds the contents of the last address examined with \"x\"."
3380 Convenience functions are defined via the Python API."
3384 add_cmd ("values", no_set_class
, show_values
, _("\
3385 Elements of value history around item number IDX (or last ten)."),
3388 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3389 Initialize a convenience variable if necessary.\n\
3390 init-if-undefined VARIABLE = EXPRESSION\n\
3391 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3392 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3393 VARIABLE is already initialized."));
3395 add_prefix_cmd ("function", no_class
, function_command
, _("\
3396 Placeholder command for showing help on convenience functions."),
3397 &functionlist
, "function ", 0, &cmdlist
);