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
;
838 require_not_optimized_out (const struct value
*value
)
840 if (value
->optimized_out
)
841 error (_("value has been optimized out"));
845 require_available (const struct value
*value
)
847 if (!VEC_empty (range_s
, value
->unavailable
))
848 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
852 value_contents_for_printing (struct value
*value
)
855 value_fetch_lazy (value
);
856 return value
->contents
;
860 value_contents_for_printing_const (const struct value
*value
)
862 gdb_assert (!value
->lazy
);
863 return value
->contents
;
867 value_contents_all (struct value
*value
)
869 const gdb_byte
*result
= value_contents_for_printing (value
);
870 require_not_optimized_out (value
);
871 require_available (value
);
875 /* Copy LENGTH bytes of SRC value's (all) contents
876 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
877 contents, starting at DST_OFFSET. If unavailable contents are
878 being copied from SRC, the corresponding DST contents are marked
879 unavailable accordingly. Neither DST nor SRC may be lazy
882 It is assumed the contents of DST in the [DST_OFFSET,
883 DST_OFFSET+LENGTH) range are wholly available. */
886 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
887 struct value
*src
, int src_offset
, int length
)
892 /* A lazy DST would make that this copy operation useless, since as
893 soon as DST's contents were un-lazied (by a later value_contents
894 call, say), the contents would be overwritten. A lazy SRC would
895 mean we'd be copying garbage. */
896 gdb_assert (!dst
->lazy
&& !src
->lazy
);
898 /* The overwritten DST range gets unavailability ORed in, not
899 replaced. Make sure to remember to implement replacing if it
900 turns out actually necessary. */
901 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
904 memcpy (value_contents_all_raw (dst
) + dst_offset
,
905 value_contents_all_raw (src
) + src_offset
,
908 /* Copy the meta-data, adjusted. */
909 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
913 l
= max (r
->offset
, src_offset
);
914 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
917 mark_value_bytes_unavailable (dst
,
918 dst_offset
+ (l
- src_offset
),
923 /* Copy LENGTH bytes of SRC value's (all) contents
924 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
925 (all) contents, starting at DST_OFFSET. If unavailable contents
926 are being copied from SRC, the corresponding DST contents are
927 marked unavailable accordingly. DST must not be lazy. If SRC is
928 lazy, it will be fetched now. If SRC is not valid (is optimized
929 out), an error is thrown.
931 It is assumed the contents of DST in the [DST_OFFSET,
932 DST_OFFSET+LENGTH) range are wholly available. */
935 value_contents_copy (struct value
*dst
, int dst_offset
,
936 struct value
*src
, int src_offset
, int length
)
938 require_not_optimized_out (src
);
941 value_fetch_lazy (src
);
943 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
947 value_lazy (struct value
*value
)
953 set_value_lazy (struct value
*value
, int val
)
959 value_stack (struct value
*value
)
965 set_value_stack (struct value
*value
, int val
)
971 value_contents (struct value
*value
)
973 const gdb_byte
*result
= value_contents_writeable (value
);
974 require_not_optimized_out (value
);
975 require_available (value
);
980 value_contents_writeable (struct value
*value
)
983 value_fetch_lazy (value
);
984 return value_contents_raw (value
);
987 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
988 this function is different from value_equal; in C the operator ==
989 can return 0 even if the two values being compared are equal. */
992 value_contents_equal (struct value
*val1
, struct value
*val2
)
998 type1
= check_typedef (value_type (val1
));
999 type2
= check_typedef (value_type (val2
));
1000 len
= TYPE_LENGTH (type1
);
1001 if (len
!= TYPE_LENGTH (type2
))
1004 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
1008 value_optimized_out (struct value
*value
)
1010 return value
->optimized_out
;
1014 set_value_optimized_out (struct value
*value
, int val
)
1016 value
->optimized_out
= val
;
1020 value_entirely_optimized_out (const struct value
*value
)
1022 if (!value
->optimized_out
)
1024 if (value
->lval
!= lval_computed
1025 || !value
->location
.computed
.funcs
->check_any_valid
)
1027 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1031 value_bits_valid (const struct value
*value
, int offset
, int length
)
1033 if (!value
->optimized_out
)
1035 if (value
->lval
!= lval_computed
1036 || !value
->location
.computed
.funcs
->check_validity
)
1038 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1043 value_bits_synthetic_pointer (const struct value
*value
,
1044 int offset
, int length
)
1046 if (value
->lval
!= lval_computed
1047 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1049 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1055 value_embedded_offset (struct value
*value
)
1057 return value
->embedded_offset
;
1061 set_value_embedded_offset (struct value
*value
, int val
)
1063 value
->embedded_offset
= val
;
1067 value_pointed_to_offset (struct value
*value
)
1069 return value
->pointed_to_offset
;
1073 set_value_pointed_to_offset (struct value
*value
, int val
)
1075 value
->pointed_to_offset
= val
;
1078 const struct lval_funcs
*
1079 value_computed_funcs (const struct value
*v
)
1081 gdb_assert (value_lval_const (v
) == lval_computed
);
1083 return v
->location
.computed
.funcs
;
1087 value_computed_closure (const struct value
*v
)
1089 gdb_assert (v
->lval
== lval_computed
);
1091 return v
->location
.computed
.closure
;
1095 deprecated_value_lval_hack (struct value
*value
)
1097 return &value
->lval
;
1101 value_lval_const (const struct value
*value
)
1107 value_address (const struct value
*value
)
1109 if (value
->lval
== lval_internalvar
1110 || value
->lval
== lval_internalvar_component
)
1112 if (value
->parent
!= NULL
)
1113 return value_address (value
->parent
) + value
->offset
;
1115 return value
->location
.address
+ value
->offset
;
1119 value_raw_address (struct value
*value
)
1121 if (value
->lval
== lval_internalvar
1122 || value
->lval
== lval_internalvar_component
)
1124 return value
->location
.address
;
1128 set_value_address (struct value
*value
, CORE_ADDR addr
)
1130 gdb_assert (value
->lval
!= lval_internalvar
1131 && value
->lval
!= lval_internalvar_component
);
1132 value
->location
.address
= addr
;
1135 struct internalvar
**
1136 deprecated_value_internalvar_hack (struct value
*value
)
1138 return &value
->location
.internalvar
;
1142 deprecated_value_frame_id_hack (struct value
*value
)
1144 return &value
->frame_id
;
1148 deprecated_value_regnum_hack (struct value
*value
)
1150 return &value
->regnum
;
1154 deprecated_value_modifiable (struct value
*value
)
1156 return value
->modifiable
;
1159 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1161 value
->modifiable
= modifiable
;
1164 /* Return a mark in the value chain. All values allocated after the
1165 mark is obtained (except for those released) are subject to being freed
1166 if a subsequent value_free_to_mark is passed the mark. */
1173 /* Take a reference to VAL. VAL will not be deallocated until all
1174 references are released. */
1177 value_incref (struct value
*val
)
1179 val
->reference_count
++;
1182 /* Release a reference to VAL, which was acquired with value_incref.
1183 This function is also called to deallocate values from the value
1187 value_free (struct value
*val
)
1191 gdb_assert (val
->reference_count
> 0);
1192 val
->reference_count
--;
1193 if (val
->reference_count
> 0)
1196 /* If there's an associated parent value, drop our reference to
1198 if (val
->parent
!= NULL
)
1199 value_free (val
->parent
);
1201 if (VALUE_LVAL (val
) == lval_computed
)
1203 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1205 if (funcs
->free_closure
)
1206 funcs
->free_closure (val
);
1209 xfree (val
->contents
);
1210 VEC_free (range_s
, val
->unavailable
);
1215 /* Free all values allocated since MARK was obtained by value_mark
1216 (except for those released). */
1218 value_free_to_mark (struct value
*mark
)
1223 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1232 /* Free all the values that have been allocated (except for those released).
1233 Call after each command, successful or not.
1234 In practice this is called before each command, which is sufficient. */
1237 free_all_values (void)
1242 for (val
= all_values
; val
; val
= next
)
1252 /* Frees all the elements in a chain of values. */
1255 free_value_chain (struct value
*v
)
1261 next
= value_next (v
);
1266 /* Remove VAL from the chain all_values
1267 so it will not be freed automatically. */
1270 release_value (struct value
*val
)
1274 if (all_values
== val
)
1276 all_values
= val
->next
;
1282 for (v
= all_values
; v
; v
= v
->next
)
1286 v
->next
= val
->next
;
1294 /* If the value is not already released, release it.
1295 If the value is already released, increment its reference count.
1296 That is, this function ensures that the value is released from the
1297 value chain and that the caller owns a reference to it. */
1300 release_value_or_incref (struct value
*val
)
1305 release_value (val
);
1308 /* Release all values up to mark */
1310 value_release_to_mark (struct value
*mark
)
1315 for (val
= next
= all_values
; next
; next
= next
->next
)
1317 if (next
->next
== mark
)
1319 all_values
= next
->next
;
1329 /* Return a copy of the value ARG.
1330 It contains the same contents, for same memory address,
1331 but it's a different block of storage. */
1334 value_copy (struct value
*arg
)
1336 struct type
*encl_type
= value_enclosing_type (arg
);
1339 if (value_lazy (arg
))
1340 val
= allocate_value_lazy (encl_type
);
1342 val
= allocate_value (encl_type
);
1343 val
->type
= arg
->type
;
1344 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1345 val
->location
= arg
->location
;
1346 val
->offset
= arg
->offset
;
1347 val
->bitpos
= arg
->bitpos
;
1348 val
->bitsize
= arg
->bitsize
;
1349 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1350 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1351 val
->lazy
= arg
->lazy
;
1352 val
->optimized_out
= arg
->optimized_out
;
1353 val
->embedded_offset
= value_embedded_offset (arg
);
1354 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1355 val
->modifiable
= arg
->modifiable
;
1356 if (!value_lazy (val
))
1358 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1359 TYPE_LENGTH (value_enclosing_type (arg
)));
1362 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1363 val
->parent
= arg
->parent
;
1365 value_incref (val
->parent
);
1366 if (VALUE_LVAL (val
) == lval_computed
)
1368 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1370 if (funcs
->copy_closure
)
1371 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1376 /* Return a version of ARG that is non-lvalue. */
1379 value_non_lval (struct value
*arg
)
1381 if (VALUE_LVAL (arg
) != not_lval
)
1383 struct type
*enc_type
= value_enclosing_type (arg
);
1384 struct value
*val
= allocate_value (enc_type
);
1386 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1387 TYPE_LENGTH (enc_type
));
1388 val
->type
= arg
->type
;
1389 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1390 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1397 set_value_component_location (struct value
*component
,
1398 const struct value
*whole
)
1400 if (whole
->lval
== lval_internalvar
)
1401 VALUE_LVAL (component
) = lval_internalvar_component
;
1403 VALUE_LVAL (component
) = whole
->lval
;
1405 component
->location
= whole
->location
;
1406 if (whole
->lval
== lval_computed
)
1408 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1410 if (funcs
->copy_closure
)
1411 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1416 /* Access to the value history. */
1418 /* Record a new value in the value history.
1419 Returns the absolute history index of the entry.
1420 Result of -1 indicates the value was not saved; otherwise it is the
1421 value history index of this new item. */
1424 record_latest_value (struct value
*val
)
1428 /* We don't want this value to have anything to do with the inferior anymore.
1429 In particular, "set $1 = 50" should not affect the variable from which
1430 the value was taken, and fast watchpoints should be able to assume that
1431 a value on the value history never changes. */
1432 if (value_lazy (val
))
1433 value_fetch_lazy (val
);
1434 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1435 from. This is a bit dubious, because then *&$1 does not just return $1
1436 but the current contents of that location. c'est la vie... */
1437 val
->modifiable
= 0;
1438 release_value (val
);
1440 /* Here we treat value_history_count as origin-zero
1441 and applying to the value being stored now. */
1443 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1446 struct value_history_chunk
*new
1447 = (struct value_history_chunk
*)
1449 xmalloc (sizeof (struct value_history_chunk
));
1450 memset (new->values
, 0, sizeof new->values
);
1451 new->next
= value_history_chain
;
1452 value_history_chain
= new;
1455 value_history_chain
->values
[i
] = val
;
1457 /* Now we regard value_history_count as origin-one
1458 and applying to the value just stored. */
1460 return ++value_history_count
;
1463 /* Return a copy of the value in the history with sequence number NUM. */
1466 access_value_history (int num
)
1468 struct value_history_chunk
*chunk
;
1473 absnum
+= value_history_count
;
1478 error (_("The history is empty."));
1480 error (_("There is only one value in the history."));
1482 error (_("History does not go back to $$%d."), -num
);
1484 if (absnum
> value_history_count
)
1485 error (_("History has not yet reached $%d."), absnum
);
1489 /* Now absnum is always absolute and origin zero. */
1491 chunk
= value_history_chain
;
1492 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1493 - absnum
/ VALUE_HISTORY_CHUNK
;
1495 chunk
= chunk
->next
;
1497 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1501 show_values (char *num_exp
, int from_tty
)
1509 /* "show values +" should print from the stored position.
1510 "show values <exp>" should print around value number <exp>. */
1511 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1512 num
= parse_and_eval_long (num_exp
) - 5;
1516 /* "show values" means print the last 10 values. */
1517 num
= value_history_count
- 9;
1523 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1525 struct value_print_options opts
;
1527 val
= access_value_history (i
);
1528 printf_filtered (("$%d = "), i
);
1529 get_user_print_options (&opts
);
1530 value_print (val
, gdb_stdout
, &opts
);
1531 printf_filtered (("\n"));
1534 /* The next "show values +" should start after what we just printed. */
1537 /* Hitting just return after this command should do the same thing as
1538 "show values +". If num_exp is null, this is unnecessary, since
1539 "show values +" is not useful after "show values". */
1540 if (from_tty
&& num_exp
)
1547 /* Internal variables. These are variables within the debugger
1548 that hold values assigned by debugger commands.
1549 The user refers to them with a '$' prefix
1550 that does not appear in the variable names stored internally. */
1554 struct internalvar
*next
;
1557 /* We support various different kinds of content of an internal variable.
1558 enum internalvar_kind specifies the kind, and union internalvar_data
1559 provides the data associated with this particular kind. */
1561 enum internalvar_kind
1563 /* The internal variable is empty. */
1566 /* The value of the internal variable is provided directly as
1567 a GDB value object. */
1570 /* A fresh value is computed via a call-back routine on every
1571 access to the internal variable. */
1572 INTERNALVAR_MAKE_VALUE
,
1574 /* The internal variable holds a GDB internal convenience function. */
1575 INTERNALVAR_FUNCTION
,
1577 /* The variable holds an integer value. */
1578 INTERNALVAR_INTEGER
,
1580 /* The variable holds a GDB-provided string. */
1585 union internalvar_data
1587 /* A value object used with INTERNALVAR_VALUE. */
1588 struct value
*value
;
1590 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1591 internalvar_make_value make_value
;
1593 /* The internal function used with INTERNALVAR_FUNCTION. */
1596 struct internal_function
*function
;
1597 /* True if this is the canonical name for the function. */
1601 /* An integer value used with INTERNALVAR_INTEGER. */
1604 /* If type is non-NULL, it will be used as the type to generate
1605 a value for this internal variable. If type is NULL, a default
1606 integer type for the architecture is used. */
1611 /* A string value used with INTERNALVAR_STRING. */
1616 static struct internalvar
*internalvars
;
1618 /* If the variable does not already exist create it and give it the
1619 value given. If no value is given then the default is zero. */
1621 init_if_undefined_command (char* args
, int from_tty
)
1623 struct internalvar
* intvar
;
1625 /* Parse the expression - this is taken from set_command(). */
1626 struct expression
*expr
= parse_expression (args
);
1627 register struct cleanup
*old_chain
=
1628 make_cleanup (free_current_contents
, &expr
);
1630 /* Validate the expression.
1631 Was the expression an assignment?
1632 Or even an expression at all? */
1633 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1634 error (_("Init-if-undefined requires an assignment expression."));
1636 /* Extract the variable from the parsed expression.
1637 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1638 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1639 error (_("The first parameter to init-if-undefined "
1640 "should be a GDB variable."));
1641 intvar
= expr
->elts
[2].internalvar
;
1643 /* Only evaluate the expression if the lvalue is void.
1644 This may still fail if the expresssion is invalid. */
1645 if (intvar
->kind
== INTERNALVAR_VOID
)
1646 evaluate_expression (expr
);
1648 do_cleanups (old_chain
);
1652 /* Look up an internal variable with name NAME. NAME should not
1653 normally include a dollar sign.
1655 If the specified internal variable does not exist,
1656 the return value is NULL. */
1658 struct internalvar
*
1659 lookup_only_internalvar (const char *name
)
1661 struct internalvar
*var
;
1663 for (var
= internalvars
; var
; var
= var
->next
)
1664 if (strcmp (var
->name
, name
) == 0)
1671 /* Create an internal variable with name NAME and with a void value.
1672 NAME should not normally include a dollar sign. */
1674 struct internalvar
*
1675 create_internalvar (const char *name
)
1677 struct internalvar
*var
;
1679 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1680 var
->name
= concat (name
, (char *)NULL
);
1681 var
->kind
= INTERNALVAR_VOID
;
1682 var
->next
= internalvars
;
1687 /* Create an internal variable with name NAME and register FUN as the
1688 function that value_of_internalvar uses to create a value whenever
1689 this variable is referenced. NAME should not normally include a
1692 struct internalvar
*
1693 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1695 struct internalvar
*var
= create_internalvar (name
);
1697 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1698 var
->u
.make_value
= fun
;
1702 /* Look up an internal variable with name NAME. NAME should not
1703 normally include a dollar sign.
1705 If the specified internal variable does not exist,
1706 one is created, with a void value. */
1708 struct internalvar
*
1709 lookup_internalvar (const char *name
)
1711 struct internalvar
*var
;
1713 var
= lookup_only_internalvar (name
);
1717 return create_internalvar (name
);
1720 /* Return current value of internal variable VAR. For variables that
1721 are not inherently typed, use a value type appropriate for GDBARCH. */
1724 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1727 struct trace_state_variable
*tsv
;
1729 /* If there is a trace state variable of the same name, assume that
1730 is what we really want to see. */
1731 tsv
= find_trace_state_variable (var
->name
);
1734 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1736 if (tsv
->value_known
)
1737 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1740 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1746 case INTERNALVAR_VOID
:
1747 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1750 case INTERNALVAR_FUNCTION
:
1751 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1754 case INTERNALVAR_INTEGER
:
1755 if (!var
->u
.integer
.type
)
1756 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1757 var
->u
.integer
.val
);
1759 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1762 case INTERNALVAR_STRING
:
1763 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1764 builtin_type (gdbarch
)->builtin_char
);
1767 case INTERNALVAR_VALUE
:
1768 val
= value_copy (var
->u
.value
);
1769 if (value_lazy (val
))
1770 value_fetch_lazy (val
);
1773 case INTERNALVAR_MAKE_VALUE
:
1774 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1778 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1781 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1782 on this value go back to affect the original internal variable.
1784 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1785 no underlying modifyable state in the internal variable.
1787 Likewise, if the variable's value is a computed lvalue, we want
1788 references to it to produce another computed lvalue, where
1789 references and assignments actually operate through the
1790 computed value's functions.
1792 This means that internal variables with computed values
1793 behave a little differently from other internal variables:
1794 assignments to them don't just replace the previous value
1795 altogether. At the moment, this seems like the behavior we
1798 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1799 && val
->lval
!= lval_computed
)
1801 VALUE_LVAL (val
) = lval_internalvar
;
1802 VALUE_INTERNALVAR (val
) = var
;
1809 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1811 if (var
->kind
== INTERNALVAR_INTEGER
)
1813 *result
= var
->u
.integer
.val
;
1817 if (var
->kind
== INTERNALVAR_VALUE
)
1819 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1821 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1823 *result
= value_as_long (var
->u
.value
);
1832 get_internalvar_function (struct internalvar
*var
,
1833 struct internal_function
**result
)
1837 case INTERNALVAR_FUNCTION
:
1838 *result
= var
->u
.fn
.function
;
1847 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1848 int bitsize
, struct value
*newval
)
1854 case INTERNALVAR_VALUE
:
1855 addr
= value_contents_writeable (var
->u
.value
);
1858 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1859 value_as_long (newval
), bitpos
, bitsize
);
1861 memcpy (addr
+ offset
, value_contents (newval
),
1862 TYPE_LENGTH (value_type (newval
)));
1866 /* We can never get a component of any other kind. */
1867 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1872 set_internalvar (struct internalvar
*var
, struct value
*val
)
1874 enum internalvar_kind new_kind
;
1875 union internalvar_data new_data
= { 0 };
1877 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1878 error (_("Cannot overwrite convenience function %s"), var
->name
);
1880 /* Prepare new contents. */
1881 switch (TYPE_CODE (check_typedef (value_type (val
))))
1883 case TYPE_CODE_VOID
:
1884 new_kind
= INTERNALVAR_VOID
;
1887 case TYPE_CODE_INTERNAL_FUNCTION
:
1888 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1889 new_kind
= INTERNALVAR_FUNCTION
;
1890 get_internalvar_function (VALUE_INTERNALVAR (val
),
1891 &new_data
.fn
.function
);
1892 /* Copies created here are never canonical. */
1896 new_kind
= INTERNALVAR_VALUE
;
1897 new_data
.value
= value_copy (val
);
1898 new_data
.value
->modifiable
= 1;
1900 /* Force the value to be fetched from the target now, to avoid problems
1901 later when this internalvar is referenced and the target is gone or
1903 if (value_lazy (new_data
.value
))
1904 value_fetch_lazy (new_data
.value
);
1906 /* Release the value from the value chain to prevent it from being
1907 deleted by free_all_values. From here on this function should not
1908 call error () until new_data is installed into the var->u to avoid
1910 release_value (new_data
.value
);
1914 /* Clean up old contents. */
1915 clear_internalvar (var
);
1918 var
->kind
= new_kind
;
1920 /* End code which must not call error(). */
1924 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1926 /* Clean up old contents. */
1927 clear_internalvar (var
);
1929 var
->kind
= INTERNALVAR_INTEGER
;
1930 var
->u
.integer
.type
= NULL
;
1931 var
->u
.integer
.val
= l
;
1935 set_internalvar_string (struct internalvar
*var
, const char *string
)
1937 /* Clean up old contents. */
1938 clear_internalvar (var
);
1940 var
->kind
= INTERNALVAR_STRING
;
1941 var
->u
.string
= xstrdup (string
);
1945 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1947 /* Clean up old contents. */
1948 clear_internalvar (var
);
1950 var
->kind
= INTERNALVAR_FUNCTION
;
1951 var
->u
.fn
.function
= f
;
1952 var
->u
.fn
.canonical
= 1;
1953 /* Variables installed here are always the canonical version. */
1957 clear_internalvar (struct internalvar
*var
)
1959 /* Clean up old contents. */
1962 case INTERNALVAR_VALUE
:
1963 value_free (var
->u
.value
);
1966 case INTERNALVAR_STRING
:
1967 xfree (var
->u
.string
);
1974 /* Reset to void kind. */
1975 var
->kind
= INTERNALVAR_VOID
;
1979 internalvar_name (struct internalvar
*var
)
1984 static struct internal_function
*
1985 create_internal_function (const char *name
,
1986 internal_function_fn handler
, void *cookie
)
1988 struct internal_function
*ifn
= XNEW (struct internal_function
);
1990 ifn
->name
= xstrdup (name
);
1991 ifn
->handler
= handler
;
1992 ifn
->cookie
= cookie
;
1997 value_internal_function_name (struct value
*val
)
1999 struct internal_function
*ifn
;
2002 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2003 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2004 gdb_assert (result
);
2010 call_internal_function (struct gdbarch
*gdbarch
,
2011 const struct language_defn
*language
,
2012 struct value
*func
, int argc
, struct value
**argv
)
2014 struct internal_function
*ifn
;
2017 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2018 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2019 gdb_assert (result
);
2021 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2024 /* The 'function' command. This does nothing -- it is just a
2025 placeholder to let "help function NAME" work. This is also used as
2026 the implementation of the sub-command that is created when
2027 registering an internal function. */
2029 function_command (char *command
, int from_tty
)
2034 /* Clean up if an internal function's command is destroyed. */
2036 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2042 /* Add a new internal function. NAME is the name of the function; DOC
2043 is a documentation string describing the function. HANDLER is
2044 called when the function is invoked. COOKIE is an arbitrary
2045 pointer which is passed to HANDLER and is intended for "user
2048 add_internal_function (const char *name
, const char *doc
,
2049 internal_function_fn handler
, void *cookie
)
2051 struct cmd_list_element
*cmd
;
2052 struct internal_function
*ifn
;
2053 struct internalvar
*var
= lookup_internalvar (name
);
2055 ifn
= create_internal_function (name
, handler
, cookie
);
2056 set_internalvar_function (var
, ifn
);
2058 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2060 cmd
->destroyer
= function_destroyer
;
2063 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2064 prevent cycles / duplicates. */
2067 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2068 htab_t copied_types
)
2070 if (TYPE_OBJFILE (value
->type
) == objfile
)
2071 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2073 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2074 value
->enclosing_type
= copy_type_recursive (objfile
,
2075 value
->enclosing_type
,
2079 /* Likewise for internal variable VAR. */
2082 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2083 htab_t copied_types
)
2087 case INTERNALVAR_INTEGER
:
2088 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2090 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2093 case INTERNALVAR_VALUE
:
2094 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2099 /* Update the internal variables and value history when OBJFILE is
2100 discarded; we must copy the types out of the objfile. New global types
2101 will be created for every convenience variable which currently points to
2102 this objfile's types, and the convenience variables will be adjusted to
2103 use the new global types. */
2106 preserve_values (struct objfile
*objfile
)
2108 htab_t copied_types
;
2109 struct value_history_chunk
*cur
;
2110 struct internalvar
*var
;
2113 /* Create the hash table. We allocate on the objfile's obstack, since
2114 it is soon to be deleted. */
2115 copied_types
= create_copied_types_hash (objfile
);
2117 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2118 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2120 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2122 for (var
= internalvars
; var
; var
= var
->next
)
2123 preserve_one_internalvar (var
, objfile
, copied_types
);
2125 preserve_python_values (objfile
, copied_types
);
2127 htab_delete (copied_types
);
2131 show_convenience (char *ignore
, int from_tty
)
2133 struct gdbarch
*gdbarch
= get_current_arch ();
2134 struct internalvar
*var
;
2136 struct value_print_options opts
;
2138 get_user_print_options (&opts
);
2139 for (var
= internalvars
; var
; var
= var
->next
)
2141 volatile struct gdb_exception ex
;
2147 printf_filtered (("$%s = "), var
->name
);
2149 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2153 val
= value_of_internalvar (gdbarch
, var
);
2154 value_print (val
, gdb_stdout
, &opts
);
2157 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2158 printf_filtered (("\n"));
2161 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2162 "Convenience variables have "
2163 "names starting with \"$\";\n"
2164 "use \"set\" as in \"set "
2165 "$foo = 5\" to define them.\n"));
2168 /* Extract a value as a C number (either long or double).
2169 Knows how to convert fixed values to double, or
2170 floating values to long.
2171 Does not deallocate the value. */
2174 value_as_long (struct value
*val
)
2176 /* This coerces arrays and functions, which is necessary (e.g.
2177 in disassemble_command). It also dereferences references, which
2178 I suspect is the most logical thing to do. */
2179 val
= coerce_array (val
);
2180 return unpack_long (value_type (val
), value_contents (val
));
2184 value_as_double (struct value
*val
)
2189 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2191 error (_("Invalid floating value found in program."));
2195 /* Extract a value as a C pointer. Does not deallocate the value.
2196 Note that val's type may not actually be a pointer; value_as_long
2197 handles all the cases. */
2199 value_as_address (struct value
*val
)
2201 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2203 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2204 whether we want this to be true eventually. */
2206 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2207 non-address (e.g. argument to "signal", "info break", etc.), or
2208 for pointers to char, in which the low bits *are* significant. */
2209 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2212 /* There are several targets (IA-64, PowerPC, and others) which
2213 don't represent pointers to functions as simply the address of
2214 the function's entry point. For example, on the IA-64, a
2215 function pointer points to a two-word descriptor, generated by
2216 the linker, which contains the function's entry point, and the
2217 value the IA-64 "global pointer" register should have --- to
2218 support position-independent code. The linker generates
2219 descriptors only for those functions whose addresses are taken.
2221 On such targets, it's difficult for GDB to convert an arbitrary
2222 function address into a function pointer; it has to either find
2223 an existing descriptor for that function, or call malloc and
2224 build its own. On some targets, it is impossible for GDB to
2225 build a descriptor at all: the descriptor must contain a jump
2226 instruction; data memory cannot be executed; and code memory
2229 Upon entry to this function, if VAL is a value of type `function'
2230 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2231 value_address (val) is the address of the function. This is what
2232 you'll get if you evaluate an expression like `main'. The call
2233 to COERCE_ARRAY below actually does all the usual unary
2234 conversions, which includes converting values of type `function'
2235 to `pointer to function'. This is the challenging conversion
2236 discussed above. Then, `unpack_long' will convert that pointer
2237 back into an address.
2239 So, suppose the user types `disassemble foo' on an architecture
2240 with a strange function pointer representation, on which GDB
2241 cannot build its own descriptors, and suppose further that `foo'
2242 has no linker-built descriptor. The address->pointer conversion
2243 will signal an error and prevent the command from running, even
2244 though the next step would have been to convert the pointer
2245 directly back into the same address.
2247 The following shortcut avoids this whole mess. If VAL is a
2248 function, just return its address directly. */
2249 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2250 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2251 return value_address (val
);
2253 val
= coerce_array (val
);
2255 /* Some architectures (e.g. Harvard), map instruction and data
2256 addresses onto a single large unified address space. For
2257 instance: An architecture may consider a large integer in the
2258 range 0x10000000 .. 0x1000ffff to already represent a data
2259 addresses (hence not need a pointer to address conversion) while
2260 a small integer would still need to be converted integer to
2261 pointer to address. Just assume such architectures handle all
2262 integer conversions in a single function. */
2266 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2267 must admonish GDB hackers to make sure its behavior matches the
2268 compiler's, whenever possible.
2270 In general, I think GDB should evaluate expressions the same way
2271 the compiler does. When the user copies an expression out of
2272 their source code and hands it to a `print' command, they should
2273 get the same value the compiler would have computed. Any
2274 deviation from this rule can cause major confusion and annoyance,
2275 and needs to be justified carefully. In other words, GDB doesn't
2276 really have the freedom to do these conversions in clever and
2279 AndrewC pointed out that users aren't complaining about how GDB
2280 casts integers to pointers; they are complaining that they can't
2281 take an address from a disassembly listing and give it to `x/i'.
2282 This is certainly important.
2284 Adding an architecture method like integer_to_address() certainly
2285 makes it possible for GDB to "get it right" in all circumstances
2286 --- the target has complete control over how things get done, so
2287 people can Do The Right Thing for their target without breaking
2288 anyone else. The standard doesn't specify how integers get
2289 converted to pointers; usually, the ABI doesn't either, but
2290 ABI-specific code is a more reasonable place to handle it. */
2292 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2293 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2294 && gdbarch_integer_to_address_p (gdbarch
))
2295 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2296 value_contents (val
));
2298 return unpack_long (value_type (val
), value_contents (val
));
2302 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2303 as a long, or as a double, assuming the raw data is described
2304 by type TYPE. Knows how to convert different sizes of values
2305 and can convert between fixed and floating point. We don't assume
2306 any alignment for the raw data. Return value is in host byte order.
2308 If you want functions and arrays to be coerced to pointers, and
2309 references to be dereferenced, call value_as_long() instead.
2311 C++: It is assumed that the front-end has taken care of
2312 all matters concerning pointers to members. A pointer
2313 to member which reaches here is considered to be equivalent
2314 to an INT (or some size). After all, it is only an offset. */
2317 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2319 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2320 enum type_code code
= TYPE_CODE (type
);
2321 int len
= TYPE_LENGTH (type
);
2322 int nosign
= TYPE_UNSIGNED (type
);
2326 case TYPE_CODE_TYPEDEF
:
2327 return unpack_long (check_typedef (type
), valaddr
);
2328 case TYPE_CODE_ENUM
:
2329 case TYPE_CODE_FLAGS
:
2330 case TYPE_CODE_BOOL
:
2332 case TYPE_CODE_CHAR
:
2333 case TYPE_CODE_RANGE
:
2334 case TYPE_CODE_MEMBERPTR
:
2336 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2338 return extract_signed_integer (valaddr
, len
, byte_order
);
2341 return extract_typed_floating (valaddr
, type
);
2343 case TYPE_CODE_DECFLOAT
:
2344 /* libdecnumber has a function to convert from decimal to integer, but
2345 it doesn't work when the decimal number has a fractional part. */
2346 return decimal_to_doublest (valaddr
, len
, byte_order
);
2350 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2351 whether we want this to be true eventually. */
2352 return extract_typed_address (valaddr
, type
);
2355 error (_("Value can't be converted to integer."));
2357 return 0; /* Placate lint. */
2360 /* Return a double value from the specified type and address.
2361 INVP points to an int which is set to 0 for valid value,
2362 1 for invalid value (bad float format). In either case,
2363 the returned double is OK to use. Argument is in target
2364 format, result is in host format. */
2367 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2369 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2370 enum type_code code
;
2374 *invp
= 0; /* Assume valid. */
2375 CHECK_TYPEDEF (type
);
2376 code
= TYPE_CODE (type
);
2377 len
= TYPE_LENGTH (type
);
2378 nosign
= TYPE_UNSIGNED (type
);
2379 if (code
== TYPE_CODE_FLT
)
2381 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2382 floating-point value was valid (using the macro
2383 INVALID_FLOAT). That test/macro have been removed.
2385 It turns out that only the VAX defined this macro and then
2386 only in a non-portable way. Fixing the portability problem
2387 wouldn't help since the VAX floating-point code is also badly
2388 bit-rotten. The target needs to add definitions for the
2389 methods gdbarch_float_format and gdbarch_double_format - these
2390 exactly describe the target floating-point format. The
2391 problem here is that the corresponding floatformat_vax_f and
2392 floatformat_vax_d values these methods should be set to are
2393 also not defined either. Oops!
2395 Hopefully someone will add both the missing floatformat
2396 definitions and the new cases for floatformat_is_valid (). */
2398 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2404 return extract_typed_floating (valaddr
, type
);
2406 else if (code
== TYPE_CODE_DECFLOAT
)
2407 return decimal_to_doublest (valaddr
, len
, byte_order
);
2410 /* Unsigned -- be sure we compensate for signed LONGEST. */
2411 return (ULONGEST
) unpack_long (type
, valaddr
);
2415 /* Signed -- we are OK with unpack_long. */
2416 return unpack_long (type
, valaddr
);
2420 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2421 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2422 We don't assume any alignment for the raw data. Return value is in
2425 If you want functions and arrays to be coerced to pointers, and
2426 references to be dereferenced, call value_as_address() instead.
2428 C++: It is assumed that the front-end has taken care of
2429 all matters concerning pointers to members. A pointer
2430 to member which reaches here is considered to be equivalent
2431 to an INT (or some size). After all, it is only an offset. */
2434 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2436 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2437 whether we want this to be true eventually. */
2438 return unpack_long (type
, valaddr
);
2442 /* Get the value of the FIELDNO'th field (which must be static) of
2443 TYPE. Return NULL if the field doesn't exist or has been
2447 value_static_field (struct type
*type
, int fieldno
)
2449 struct value
*retval
;
2451 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2453 case FIELD_LOC_KIND_PHYSADDR
:
2454 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2455 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2457 case FIELD_LOC_KIND_PHYSNAME
:
2459 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2460 /* TYPE_FIELD_NAME (type, fieldno); */
2461 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2465 /* With some compilers, e.g. HP aCC, static data members are
2466 reported as non-debuggable symbols. */
2467 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2474 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2475 SYMBOL_VALUE_ADDRESS (msym
));
2479 retval
= value_of_variable (sym
, NULL
);
2483 gdb_assert_not_reached ("unexpected field location kind");
2489 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2490 You have to be careful here, since the size of the data area for the value
2491 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2492 than the old enclosing type, you have to allocate more space for the
2496 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2498 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2500 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2502 val
->enclosing_type
= new_encl_type
;
2505 /* Given a value ARG1 (offset by OFFSET bytes)
2506 of a struct or union type ARG_TYPE,
2507 extract and return the value of one of its (non-static) fields.
2508 FIELDNO says which field. */
2511 value_primitive_field (struct value
*arg1
, int offset
,
2512 int fieldno
, struct type
*arg_type
)
2517 CHECK_TYPEDEF (arg_type
);
2518 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2520 /* Call check_typedef on our type to make sure that, if TYPE
2521 is a TYPE_CODE_TYPEDEF, its length is set to the length
2522 of the target type instead of zero. However, we do not
2523 replace the typedef type by the target type, because we want
2524 to keep the typedef in order to be able to print the type
2525 description correctly. */
2526 check_typedef (type
);
2528 if (value_optimized_out (arg1
))
2529 v
= allocate_optimized_out_value (type
);
2530 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2532 /* Handle packed fields.
2534 Create a new value for the bitfield, with bitpos and bitsize
2535 set. If possible, arrange offset and bitpos so that we can
2536 do a single aligned read of the size of the containing type.
2537 Otherwise, adjust offset to the byte containing the first
2538 bit. Assume that the address, offset, and embedded offset
2539 are sufficiently aligned. */
2541 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2542 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2544 v
= allocate_value_lazy (type
);
2545 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2546 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2547 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2548 v
->bitpos
= bitpos
% container_bitsize
;
2550 v
->bitpos
= bitpos
% 8;
2551 v
->offset
= (value_embedded_offset (arg1
)
2553 + (bitpos
- v
->bitpos
) / 8);
2555 value_incref (v
->parent
);
2556 if (!value_lazy (arg1
))
2557 value_fetch_lazy (v
);
2559 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2561 /* This field is actually a base subobject, so preserve the
2562 entire object's contents for later references to virtual
2566 /* Lazy register values with offsets are not supported. */
2567 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2568 value_fetch_lazy (arg1
);
2570 /* We special case virtual inheritance here because this
2571 requires access to the contents, which we would rather avoid
2572 for references to ordinary fields of unavailable values. */
2573 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2574 boffset
= baseclass_offset (arg_type
, fieldno
,
2575 value_contents (arg1
),
2576 value_embedded_offset (arg1
),
2577 value_address (arg1
),
2580 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2582 if (value_lazy (arg1
))
2583 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2586 v
= allocate_value (value_enclosing_type (arg1
));
2587 value_contents_copy_raw (v
, 0, arg1
, 0,
2588 TYPE_LENGTH (value_enclosing_type (arg1
)));
2591 v
->offset
= value_offset (arg1
);
2592 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2596 /* Plain old data member */
2597 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2599 /* Lazy register values with offsets are not supported. */
2600 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2601 value_fetch_lazy (arg1
);
2603 if (value_lazy (arg1
))
2604 v
= allocate_value_lazy (type
);
2607 v
= allocate_value (type
);
2608 value_contents_copy_raw (v
, value_embedded_offset (v
),
2609 arg1
, value_embedded_offset (arg1
) + offset
,
2610 TYPE_LENGTH (type
));
2612 v
->offset
= (value_offset (arg1
) + offset
2613 + value_embedded_offset (arg1
));
2615 set_value_component_location (v
, arg1
);
2616 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2617 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2621 /* Given a value ARG1 of a struct or union type,
2622 extract and return the value of one of its (non-static) fields.
2623 FIELDNO says which field. */
2626 value_field (struct value
*arg1
, int fieldno
)
2628 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2631 /* Return a non-virtual function as a value.
2632 F is the list of member functions which contains the desired method.
2633 J is an index into F which provides the desired method.
2635 We only use the symbol for its address, so be happy with either a
2636 full symbol or a minimal symbol. */
2639 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2640 int j
, struct type
*type
,
2644 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2645 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2647 struct minimal_symbol
*msym
;
2649 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2656 gdb_assert (sym
== NULL
);
2657 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2662 v
= allocate_value (ftype
);
2665 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2669 /* The minimal symbol might point to a function descriptor;
2670 resolve it to the actual code address instead. */
2671 struct objfile
*objfile
= msymbol_objfile (msym
);
2672 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2674 set_value_address (v
,
2675 gdbarch_convert_from_func_ptr_addr
2676 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2681 if (type
!= value_type (*arg1p
))
2682 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2683 value_addr (*arg1p
)));
2685 /* Move the `this' pointer according to the offset.
2686 VALUE_OFFSET (*arg1p) += offset; */
2694 /* Helper function for both unpack_value_bits_as_long and
2695 unpack_bits_as_long. See those functions for more details on the
2696 interface; the only difference is that this function accepts either
2697 a NULL or a non-NULL ORIGINAL_VALUE. */
2700 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2701 int embedded_offset
, int bitpos
, int bitsize
,
2702 const struct value
*original_value
,
2705 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2712 /* Read the minimum number of bytes required; there may not be
2713 enough bytes to read an entire ULONGEST. */
2714 CHECK_TYPEDEF (field_type
);
2716 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2718 bytes_read
= TYPE_LENGTH (field_type
);
2720 read_offset
= bitpos
/ 8;
2722 if (original_value
!= NULL
2723 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2727 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2728 bytes_read
, byte_order
);
2730 /* Extract bits. See comment above. */
2732 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2733 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2735 lsbcount
= (bitpos
% 8);
2738 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2739 If the field is signed, and is negative, then sign extend. */
2741 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2743 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2745 if (!TYPE_UNSIGNED (field_type
))
2747 if (val
& (valmask
^ (valmask
>> 1)))
2758 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2759 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2760 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2761 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2764 Returns false if the value contents are unavailable, otherwise
2765 returns true, indicating a valid value has been stored in *RESULT.
2767 Extracting bits depends on endianness of the machine. Compute the
2768 number of least significant bits to discard. For big endian machines,
2769 we compute the total number of bits in the anonymous object, subtract
2770 off the bit count from the MSB of the object to the MSB of the
2771 bitfield, then the size of the bitfield, which leaves the LSB discard
2772 count. For little endian machines, the discard count is simply the
2773 number of bits from the LSB of the anonymous object to the LSB of the
2776 If the field is signed, we also do sign extension. */
2779 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2780 int embedded_offset
, int bitpos
, int bitsize
,
2781 const struct value
*original_value
,
2784 gdb_assert (original_value
!= NULL
);
2786 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2787 bitpos
, bitsize
, original_value
, result
);
2791 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2792 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2793 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2797 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2798 int embedded_offset
, int fieldno
,
2799 const struct value
*val
, LONGEST
*result
)
2801 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2802 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2803 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2805 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2806 bitpos
, bitsize
, val
,
2810 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2811 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2812 ORIGINAL_VALUE, which must not be NULL. See
2813 unpack_value_bits_as_long for more details. */
2816 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2817 int embedded_offset
, int fieldno
,
2818 const struct value
*val
, LONGEST
*result
)
2820 gdb_assert (val
!= NULL
);
2822 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2823 fieldno
, val
, result
);
2826 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2827 object at VALADDR. See unpack_value_bits_as_long for more details.
2828 This function differs from unpack_value_field_as_long in that it
2829 operates without a struct value object. */
2832 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2836 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2840 /* Return a new value with type TYPE, which is FIELDNO field of the
2841 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2842 of VAL. If the VAL's contents required to extract the bitfield
2843 from are unavailable, the new value is correspondingly marked as
2847 value_field_bitfield (struct type
*type
, int fieldno
,
2848 const gdb_byte
*valaddr
,
2849 int embedded_offset
, const struct value
*val
)
2853 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2856 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2857 struct value
*retval
= allocate_value (field_type
);
2858 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2863 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2867 /* Modify the value of a bitfield. ADDR points to a block of memory in
2868 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2869 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2870 indicate which bits (in target bit order) comprise the bitfield.
2871 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2872 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2875 modify_field (struct type
*type
, gdb_byte
*addr
,
2876 LONGEST fieldval
, int bitpos
, int bitsize
)
2878 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2880 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2883 /* Normalize BITPOS. */
2887 /* If a negative fieldval fits in the field in question, chop
2888 off the sign extension bits. */
2889 if ((~fieldval
& ~(mask
>> 1)) == 0)
2892 /* Warn if value is too big to fit in the field in question. */
2893 if (0 != (fieldval
& ~mask
))
2895 /* FIXME: would like to include fieldval in the message, but
2896 we don't have a sprintf_longest. */
2897 warning (_("Value does not fit in %d bits."), bitsize
);
2899 /* Truncate it, otherwise adjoining fields may be corrupted. */
2903 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2904 false valgrind reports. */
2906 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2907 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2909 /* Shifting for bit field depends on endianness of the target machine. */
2910 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2911 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2913 oword
&= ~(mask
<< bitpos
);
2914 oword
|= fieldval
<< bitpos
;
2916 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2919 /* Pack NUM into BUF using a target format of TYPE. */
2922 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2924 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2927 type
= check_typedef (type
);
2928 len
= TYPE_LENGTH (type
);
2930 switch (TYPE_CODE (type
))
2933 case TYPE_CODE_CHAR
:
2934 case TYPE_CODE_ENUM
:
2935 case TYPE_CODE_FLAGS
:
2936 case TYPE_CODE_BOOL
:
2937 case TYPE_CODE_RANGE
:
2938 case TYPE_CODE_MEMBERPTR
:
2939 store_signed_integer (buf
, len
, byte_order
, num
);
2944 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2948 error (_("Unexpected type (%d) encountered for integer constant."),
2954 /* Pack NUM into BUF using a target format of TYPE. */
2957 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2960 enum bfd_endian byte_order
;
2962 type
= check_typedef (type
);
2963 len
= TYPE_LENGTH (type
);
2964 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2966 switch (TYPE_CODE (type
))
2969 case TYPE_CODE_CHAR
:
2970 case TYPE_CODE_ENUM
:
2971 case TYPE_CODE_FLAGS
:
2972 case TYPE_CODE_BOOL
:
2973 case TYPE_CODE_RANGE
:
2974 case TYPE_CODE_MEMBERPTR
:
2975 store_unsigned_integer (buf
, len
, byte_order
, num
);
2980 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2984 error (_("Unexpected type (%d) encountered "
2985 "for unsigned integer constant."),
2991 /* Convert C numbers into newly allocated values. */
2994 value_from_longest (struct type
*type
, LONGEST num
)
2996 struct value
*val
= allocate_value (type
);
2998 pack_long (value_contents_raw (val
), type
, num
);
3003 /* Convert C unsigned numbers into newly allocated values. */
3006 value_from_ulongest (struct type
*type
, ULONGEST num
)
3008 struct value
*val
= allocate_value (type
);
3010 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3016 /* Create a value representing a pointer of type TYPE to the address
3019 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3021 struct value
*val
= allocate_value (type
);
3023 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3028 /* Create a value of type TYPE whose contents come from VALADDR, if it
3029 is non-null, and whose memory address (in the inferior) is
3033 value_from_contents_and_address (struct type
*type
,
3034 const gdb_byte
*valaddr
,
3039 if (valaddr
== NULL
)
3040 v
= allocate_value_lazy (type
);
3043 v
= allocate_value (type
);
3044 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3046 set_value_address (v
, address
);
3047 VALUE_LVAL (v
) = lval_memory
;
3051 /* Create a value of type TYPE holding the contents CONTENTS.
3052 The new value is `not_lval'. */
3055 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3057 struct value
*result
;
3059 result
= allocate_value (type
);
3060 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3065 value_from_double (struct type
*type
, DOUBLEST num
)
3067 struct value
*val
= allocate_value (type
);
3068 struct type
*base_type
= check_typedef (type
);
3069 enum type_code code
= TYPE_CODE (base_type
);
3071 if (code
== TYPE_CODE_FLT
)
3073 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3076 error (_("Unexpected type encountered for floating constant."));
3082 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3084 struct value
*val
= allocate_value (type
);
3086 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3090 /* Extract a value from the history file. Input will be of the form
3091 $digits or $$digits. See block comment above 'write_dollar_variable'
3095 value_from_history_ref (char *h
, char **endp
)
3107 /* Find length of numeral string. */
3108 for (; isdigit (h
[len
]); len
++)
3111 /* Make sure numeral string is not part of an identifier. */
3112 if (h
[len
] == '_' || isalpha (h
[len
]))
3115 /* Now collect the index value. */
3120 /* For some bizarre reason, "$$" is equivalent to "$$1",
3121 rather than to "$$0" as it ought to be! */
3126 index
= -strtol (&h
[2], endp
, 10);
3132 /* "$" is equivalent to "$0". */
3137 index
= strtol (&h
[1], endp
, 10);
3140 return access_value_history (index
);
3144 coerce_ref_if_computed (const struct value
*arg
)
3146 const struct lval_funcs
*funcs
;
3148 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3151 if (value_lval_const (arg
) != lval_computed
)
3154 funcs
= value_computed_funcs (arg
);
3155 if (funcs
->coerce_ref
== NULL
)
3158 return funcs
->coerce_ref (arg
);
3161 /* Look at value.h for description. */
3164 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3165 struct type
*original_type
,
3166 struct value
*original_value
)
3168 /* Re-adjust type. */
3169 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3171 /* Add embedding info. */
3172 set_value_enclosing_type (value
, enc_type
);
3173 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3175 /* We may be pointing to an object of some derived type. */
3176 return value_full_object (value
, NULL
, 0, 0, 0);
3180 coerce_ref (struct value
*arg
)
3182 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3183 struct value
*retval
;
3184 struct type
*enc_type
;
3186 retval
= coerce_ref_if_computed (arg
);
3190 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3193 enc_type
= check_typedef (value_enclosing_type (arg
));
3194 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3196 retval
= value_at_lazy (enc_type
,
3197 unpack_pointer (value_type (arg
),
3198 value_contents (arg
)));
3199 return readjust_indirect_value_type (retval
, enc_type
,
3200 value_type_arg_tmp
, arg
);
3204 coerce_array (struct value
*arg
)
3208 arg
= coerce_ref (arg
);
3209 type
= check_typedef (value_type (arg
));
3211 switch (TYPE_CODE (type
))
3213 case TYPE_CODE_ARRAY
:
3214 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3215 arg
= value_coerce_array (arg
);
3217 case TYPE_CODE_FUNC
:
3218 arg
= value_coerce_function (arg
);
3225 /* Return true if the function returning the specified type is using
3226 the convention of returning structures in memory (passing in the
3227 address as a hidden first parameter). */
3230 using_struct_return (struct gdbarch
*gdbarch
,
3231 struct type
*func_type
, struct type
*value_type
)
3233 enum type_code code
= TYPE_CODE (value_type
);
3235 if (code
== TYPE_CODE_ERROR
)
3236 error (_("Function return type unknown."));
3238 if (code
== TYPE_CODE_VOID
)
3239 /* A void return value is never in memory. See also corresponding
3240 code in "print_return_value". */
3243 /* Probe the architecture for the return-value convention. */
3244 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3246 != RETURN_VALUE_REGISTER_CONVENTION
);
3249 /* Set the initialized field in a value struct. */
3252 set_value_initialized (struct value
*val
, int status
)
3254 val
->initialized
= status
;
3257 /* Return the initialized field in a value struct. */
3260 value_initialized (struct value
*val
)
3262 return val
->initialized
;
3266 _initialize_values (void)
3268 add_cmd ("convenience", no_class
, show_convenience
, _("\
3269 Debugger convenience (\"$foo\") variables.\n\
3270 These variables are created when you assign them values;\n\
3271 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3273 A few convenience variables are given values automatically:\n\
3274 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3275 \"$__\" holds the contents of the last address examined with \"x\"."),
3278 add_cmd ("values", no_set_class
, show_values
, _("\
3279 Elements of value history around item number IDX (or last ten)."),
3282 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3283 Initialize a convenience variable if necessary.\n\
3284 init-if-undefined VARIABLE = EXPRESSION\n\
3285 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3286 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3287 VARIABLE is already initialized."));
3289 add_prefix_cmd ("function", no_class
, function_command
, _("\
3290 Placeholder command for showing help on convenience functions."),
3291 &functionlist
, "function ", 0, &cmdlist
);