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
;
844 struct value
*target
;
847 get_user_print_options (&opts
);
850 *real_type_found
= 0;
851 result
= value_type (value
);
852 if (opts
.objectprint
)
854 if (TYPE_CODE (result
) == TYPE_CODE_PTR
855 || TYPE_CODE (result
) == TYPE_CODE_REF
)
857 struct type
*real_type
;
859 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
863 *real_type_found
= 1;
867 else if (resolve_simple_types
)
870 *real_type_found
= 1;
871 result
= value_enclosing_type (value
);
879 require_not_optimized_out (const struct value
*value
)
881 if (value
->optimized_out
)
882 error (_("value has been optimized out"));
886 require_available (const struct value
*value
)
888 if (!VEC_empty (range_s
, value
->unavailable
))
889 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
893 value_contents_for_printing (struct value
*value
)
896 value_fetch_lazy (value
);
897 return value
->contents
;
901 value_contents_for_printing_const (const struct value
*value
)
903 gdb_assert (!value
->lazy
);
904 return value
->contents
;
908 value_contents_all (struct value
*value
)
910 const gdb_byte
*result
= value_contents_for_printing (value
);
911 require_not_optimized_out (value
);
912 require_available (value
);
916 /* Copy LENGTH bytes of SRC value's (all) contents
917 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
918 contents, starting at DST_OFFSET. If unavailable contents are
919 being copied from SRC, the corresponding DST contents are marked
920 unavailable accordingly. Neither DST nor SRC may be lazy
923 It is assumed the contents of DST in the [DST_OFFSET,
924 DST_OFFSET+LENGTH) range are wholly available. */
927 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
928 struct value
*src
, int src_offset
, int length
)
933 /* A lazy DST would make that this copy operation useless, since as
934 soon as DST's contents were un-lazied (by a later value_contents
935 call, say), the contents would be overwritten. A lazy SRC would
936 mean we'd be copying garbage. */
937 gdb_assert (!dst
->lazy
&& !src
->lazy
);
939 /* The overwritten DST range gets unavailability ORed in, not
940 replaced. Make sure to remember to implement replacing if it
941 turns out actually necessary. */
942 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
945 memcpy (value_contents_all_raw (dst
) + dst_offset
,
946 value_contents_all_raw (src
) + src_offset
,
949 /* Copy the meta-data, adjusted. */
950 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
954 l
= max (r
->offset
, src_offset
);
955 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
958 mark_value_bytes_unavailable (dst
,
959 dst_offset
+ (l
- src_offset
),
964 /* Copy LENGTH bytes of SRC value's (all) contents
965 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
966 (all) contents, starting at DST_OFFSET. If unavailable contents
967 are being copied from SRC, the corresponding DST contents are
968 marked unavailable accordingly. DST must not be lazy. If SRC is
969 lazy, it will be fetched now. If SRC is not valid (is optimized
970 out), an error is thrown.
972 It is assumed the contents of DST in the [DST_OFFSET,
973 DST_OFFSET+LENGTH) range are wholly available. */
976 value_contents_copy (struct value
*dst
, int dst_offset
,
977 struct value
*src
, int src_offset
, int length
)
979 require_not_optimized_out (src
);
982 value_fetch_lazy (src
);
984 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
988 value_lazy (struct value
*value
)
994 set_value_lazy (struct value
*value
, int val
)
1000 value_stack (struct value
*value
)
1002 return value
->stack
;
1006 set_value_stack (struct value
*value
, int val
)
1012 value_contents (struct value
*value
)
1014 const gdb_byte
*result
= value_contents_writeable (value
);
1015 require_not_optimized_out (value
);
1016 require_available (value
);
1021 value_contents_writeable (struct value
*value
)
1024 value_fetch_lazy (value
);
1025 return value_contents_raw (value
);
1028 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1029 this function is different from value_equal; in C the operator ==
1030 can return 0 even if the two values being compared are equal. */
1033 value_contents_equal (struct value
*val1
, struct value
*val2
)
1039 type1
= check_typedef (value_type (val1
));
1040 type2
= check_typedef (value_type (val2
));
1041 len
= TYPE_LENGTH (type1
);
1042 if (len
!= TYPE_LENGTH (type2
))
1045 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
1049 value_optimized_out (struct value
*value
)
1051 return value
->optimized_out
;
1055 set_value_optimized_out (struct value
*value
, int val
)
1057 value
->optimized_out
= val
;
1061 value_entirely_optimized_out (const struct value
*value
)
1063 if (!value
->optimized_out
)
1065 if (value
->lval
!= lval_computed
1066 || !value
->location
.computed
.funcs
->check_any_valid
)
1068 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1072 value_bits_valid (const struct value
*value
, int offset
, int length
)
1074 if (!value
->optimized_out
)
1076 if (value
->lval
!= lval_computed
1077 || !value
->location
.computed
.funcs
->check_validity
)
1079 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1084 value_bits_synthetic_pointer (const struct value
*value
,
1085 int offset
, int length
)
1087 if (value
->lval
!= lval_computed
1088 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1090 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1096 value_embedded_offset (struct value
*value
)
1098 return value
->embedded_offset
;
1102 set_value_embedded_offset (struct value
*value
, int val
)
1104 value
->embedded_offset
= val
;
1108 value_pointed_to_offset (struct value
*value
)
1110 return value
->pointed_to_offset
;
1114 set_value_pointed_to_offset (struct value
*value
, int val
)
1116 value
->pointed_to_offset
= val
;
1119 const struct lval_funcs
*
1120 value_computed_funcs (const struct value
*v
)
1122 gdb_assert (value_lval_const (v
) == lval_computed
);
1124 return v
->location
.computed
.funcs
;
1128 value_computed_closure (const struct value
*v
)
1130 gdb_assert (v
->lval
== lval_computed
);
1132 return v
->location
.computed
.closure
;
1136 deprecated_value_lval_hack (struct value
*value
)
1138 return &value
->lval
;
1142 value_lval_const (const struct value
*value
)
1148 value_address (const struct value
*value
)
1150 if (value
->lval
== lval_internalvar
1151 || value
->lval
== lval_internalvar_component
)
1153 if (value
->parent
!= NULL
)
1154 return value_address (value
->parent
) + value
->offset
;
1156 return value
->location
.address
+ value
->offset
;
1160 value_raw_address (struct value
*value
)
1162 if (value
->lval
== lval_internalvar
1163 || value
->lval
== lval_internalvar_component
)
1165 return value
->location
.address
;
1169 set_value_address (struct value
*value
, CORE_ADDR addr
)
1171 gdb_assert (value
->lval
!= lval_internalvar
1172 && value
->lval
!= lval_internalvar_component
);
1173 value
->location
.address
= addr
;
1176 struct internalvar
**
1177 deprecated_value_internalvar_hack (struct value
*value
)
1179 return &value
->location
.internalvar
;
1183 deprecated_value_frame_id_hack (struct value
*value
)
1185 return &value
->frame_id
;
1189 deprecated_value_regnum_hack (struct value
*value
)
1191 return &value
->regnum
;
1195 deprecated_value_modifiable (struct value
*value
)
1197 return value
->modifiable
;
1200 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1202 value
->modifiable
= modifiable
;
1205 /* Return a mark in the value chain. All values allocated after the
1206 mark is obtained (except for those released) are subject to being freed
1207 if a subsequent value_free_to_mark is passed the mark. */
1214 /* Take a reference to VAL. VAL will not be deallocated until all
1215 references are released. */
1218 value_incref (struct value
*val
)
1220 val
->reference_count
++;
1223 /* Release a reference to VAL, which was acquired with value_incref.
1224 This function is also called to deallocate values from the value
1228 value_free (struct value
*val
)
1232 gdb_assert (val
->reference_count
> 0);
1233 val
->reference_count
--;
1234 if (val
->reference_count
> 0)
1237 /* If there's an associated parent value, drop our reference to
1239 if (val
->parent
!= NULL
)
1240 value_free (val
->parent
);
1242 if (VALUE_LVAL (val
) == lval_computed
)
1244 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1246 if (funcs
->free_closure
)
1247 funcs
->free_closure (val
);
1250 xfree (val
->contents
);
1251 VEC_free (range_s
, val
->unavailable
);
1256 /* Free all values allocated since MARK was obtained by value_mark
1257 (except for those released). */
1259 value_free_to_mark (struct value
*mark
)
1264 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1273 /* Free all the values that have been allocated (except for those released).
1274 Call after each command, successful or not.
1275 In practice this is called before each command, which is sufficient. */
1278 free_all_values (void)
1283 for (val
= all_values
; val
; val
= next
)
1293 /* Frees all the elements in a chain of values. */
1296 free_value_chain (struct value
*v
)
1302 next
= value_next (v
);
1307 /* Remove VAL from the chain all_values
1308 so it will not be freed automatically. */
1311 release_value (struct value
*val
)
1315 if (all_values
== val
)
1317 all_values
= val
->next
;
1323 for (v
= all_values
; v
; v
= v
->next
)
1327 v
->next
= val
->next
;
1335 /* If the value is not already released, release it.
1336 If the value is already released, increment its reference count.
1337 That is, this function ensures that the value is released from the
1338 value chain and that the caller owns a reference to it. */
1341 release_value_or_incref (struct value
*val
)
1346 release_value (val
);
1349 /* Release all values up to mark */
1351 value_release_to_mark (struct value
*mark
)
1356 for (val
= next
= all_values
; next
; next
= next
->next
)
1358 if (next
->next
== mark
)
1360 all_values
= next
->next
;
1370 /* Return a copy of the value ARG.
1371 It contains the same contents, for same memory address,
1372 but it's a different block of storage. */
1375 value_copy (struct value
*arg
)
1377 struct type
*encl_type
= value_enclosing_type (arg
);
1380 if (value_lazy (arg
))
1381 val
= allocate_value_lazy (encl_type
);
1383 val
= allocate_value (encl_type
);
1384 val
->type
= arg
->type
;
1385 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1386 val
->location
= arg
->location
;
1387 val
->offset
= arg
->offset
;
1388 val
->bitpos
= arg
->bitpos
;
1389 val
->bitsize
= arg
->bitsize
;
1390 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1391 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1392 val
->lazy
= arg
->lazy
;
1393 val
->optimized_out
= arg
->optimized_out
;
1394 val
->embedded_offset
= value_embedded_offset (arg
);
1395 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1396 val
->modifiable
= arg
->modifiable
;
1397 if (!value_lazy (val
))
1399 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1400 TYPE_LENGTH (value_enclosing_type (arg
)));
1403 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1404 val
->parent
= arg
->parent
;
1406 value_incref (val
->parent
);
1407 if (VALUE_LVAL (val
) == lval_computed
)
1409 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1411 if (funcs
->copy_closure
)
1412 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1417 /* Return a version of ARG that is non-lvalue. */
1420 value_non_lval (struct value
*arg
)
1422 if (VALUE_LVAL (arg
) != not_lval
)
1424 struct type
*enc_type
= value_enclosing_type (arg
);
1425 struct value
*val
= allocate_value (enc_type
);
1427 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1428 TYPE_LENGTH (enc_type
));
1429 val
->type
= arg
->type
;
1430 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1431 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1438 set_value_component_location (struct value
*component
,
1439 const struct value
*whole
)
1441 if (whole
->lval
== lval_internalvar
)
1442 VALUE_LVAL (component
) = lval_internalvar_component
;
1444 VALUE_LVAL (component
) = whole
->lval
;
1446 component
->location
= whole
->location
;
1447 if (whole
->lval
== lval_computed
)
1449 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1451 if (funcs
->copy_closure
)
1452 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1457 /* Access to the value history. */
1459 /* Record a new value in the value history.
1460 Returns the absolute history index of the entry.
1461 Result of -1 indicates the value was not saved; otherwise it is the
1462 value history index of this new item. */
1465 record_latest_value (struct value
*val
)
1469 /* We don't want this value to have anything to do with the inferior anymore.
1470 In particular, "set $1 = 50" should not affect the variable from which
1471 the value was taken, and fast watchpoints should be able to assume that
1472 a value on the value history never changes. */
1473 if (value_lazy (val
))
1474 value_fetch_lazy (val
);
1475 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1476 from. This is a bit dubious, because then *&$1 does not just return $1
1477 but the current contents of that location. c'est la vie... */
1478 val
->modifiable
= 0;
1479 release_value (val
);
1481 /* Here we treat value_history_count as origin-zero
1482 and applying to the value being stored now. */
1484 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1487 struct value_history_chunk
*new
1488 = (struct value_history_chunk
*)
1490 xmalloc (sizeof (struct value_history_chunk
));
1491 memset (new->values
, 0, sizeof new->values
);
1492 new->next
= value_history_chain
;
1493 value_history_chain
= new;
1496 value_history_chain
->values
[i
] = val
;
1498 /* Now we regard value_history_count as origin-one
1499 and applying to the value just stored. */
1501 return ++value_history_count
;
1504 /* Return a copy of the value in the history with sequence number NUM. */
1507 access_value_history (int num
)
1509 struct value_history_chunk
*chunk
;
1514 absnum
+= value_history_count
;
1519 error (_("The history is empty."));
1521 error (_("There is only one value in the history."));
1523 error (_("History does not go back to $$%d."), -num
);
1525 if (absnum
> value_history_count
)
1526 error (_("History has not yet reached $%d."), absnum
);
1530 /* Now absnum is always absolute and origin zero. */
1532 chunk
= value_history_chain
;
1533 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1534 - absnum
/ VALUE_HISTORY_CHUNK
;
1536 chunk
= chunk
->next
;
1538 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1542 show_values (char *num_exp
, int from_tty
)
1550 /* "show values +" should print from the stored position.
1551 "show values <exp>" should print around value number <exp>. */
1552 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1553 num
= parse_and_eval_long (num_exp
) - 5;
1557 /* "show values" means print the last 10 values. */
1558 num
= value_history_count
- 9;
1564 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1566 struct value_print_options opts
;
1568 val
= access_value_history (i
);
1569 printf_filtered (("$%d = "), i
);
1570 get_user_print_options (&opts
);
1571 value_print (val
, gdb_stdout
, &opts
);
1572 printf_filtered (("\n"));
1575 /* The next "show values +" should start after what we just printed. */
1578 /* Hitting just return after this command should do the same thing as
1579 "show values +". If num_exp is null, this is unnecessary, since
1580 "show values +" is not useful after "show values". */
1581 if (from_tty
&& num_exp
)
1588 /* Internal variables. These are variables within the debugger
1589 that hold values assigned by debugger commands.
1590 The user refers to them with a '$' prefix
1591 that does not appear in the variable names stored internally. */
1595 struct internalvar
*next
;
1598 /* We support various different kinds of content of an internal variable.
1599 enum internalvar_kind specifies the kind, and union internalvar_data
1600 provides the data associated with this particular kind. */
1602 enum internalvar_kind
1604 /* The internal variable is empty. */
1607 /* The value of the internal variable is provided directly as
1608 a GDB value object. */
1611 /* A fresh value is computed via a call-back routine on every
1612 access to the internal variable. */
1613 INTERNALVAR_MAKE_VALUE
,
1615 /* The internal variable holds a GDB internal convenience function. */
1616 INTERNALVAR_FUNCTION
,
1618 /* The variable holds an integer value. */
1619 INTERNALVAR_INTEGER
,
1621 /* The variable holds a GDB-provided string. */
1626 union internalvar_data
1628 /* A value object used with INTERNALVAR_VALUE. */
1629 struct value
*value
;
1631 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1634 /* The functions to call. */
1635 const struct internalvar_funcs
*functions
;
1637 /* The function's user-data. */
1641 /* The internal function used with INTERNALVAR_FUNCTION. */
1644 struct internal_function
*function
;
1645 /* True if this is the canonical name for the function. */
1649 /* An integer value used with INTERNALVAR_INTEGER. */
1652 /* If type is non-NULL, it will be used as the type to generate
1653 a value for this internal variable. If type is NULL, a default
1654 integer type for the architecture is used. */
1659 /* A string value used with INTERNALVAR_STRING. */
1664 static struct internalvar
*internalvars
;
1666 /* If the variable does not already exist create it and give it the
1667 value given. If no value is given then the default is zero. */
1669 init_if_undefined_command (char* args
, int from_tty
)
1671 struct internalvar
* intvar
;
1673 /* Parse the expression - this is taken from set_command(). */
1674 struct expression
*expr
= parse_expression (args
);
1675 register struct cleanup
*old_chain
=
1676 make_cleanup (free_current_contents
, &expr
);
1678 /* Validate the expression.
1679 Was the expression an assignment?
1680 Or even an expression at all? */
1681 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1682 error (_("Init-if-undefined requires an assignment expression."));
1684 /* Extract the variable from the parsed expression.
1685 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1686 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1687 error (_("The first parameter to init-if-undefined "
1688 "should be a GDB variable."));
1689 intvar
= expr
->elts
[2].internalvar
;
1691 /* Only evaluate the expression if the lvalue is void.
1692 This may still fail if the expresssion is invalid. */
1693 if (intvar
->kind
== INTERNALVAR_VOID
)
1694 evaluate_expression (expr
);
1696 do_cleanups (old_chain
);
1700 /* Look up an internal variable with name NAME. NAME should not
1701 normally include a dollar sign.
1703 If the specified internal variable does not exist,
1704 the return value is NULL. */
1706 struct internalvar
*
1707 lookup_only_internalvar (const char *name
)
1709 struct internalvar
*var
;
1711 for (var
= internalvars
; var
; var
= var
->next
)
1712 if (strcmp (var
->name
, name
) == 0)
1719 /* Create an internal variable with name NAME and with a void value.
1720 NAME should not normally include a dollar sign. */
1722 struct internalvar
*
1723 create_internalvar (const char *name
)
1725 struct internalvar
*var
;
1727 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1728 var
->name
= concat (name
, (char *)NULL
);
1729 var
->kind
= INTERNALVAR_VOID
;
1730 var
->next
= internalvars
;
1735 /* Create an internal variable with name NAME and register FUN as the
1736 function that value_of_internalvar uses to create a value whenever
1737 this variable is referenced. NAME should not normally include a
1738 dollar sign. DATA is passed uninterpreted to FUN when it is
1739 called. CLEANUP, if not NULL, is called when the internal variable
1740 is destroyed. It is passed DATA as its only argument. */
1742 struct internalvar
*
1743 create_internalvar_type_lazy (const char *name
,
1744 const struct internalvar_funcs
*funcs
,
1747 struct internalvar
*var
= create_internalvar (name
);
1749 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1750 var
->u
.make_value
.functions
= funcs
;
1751 var
->u
.make_value
.data
= data
;
1755 /* See documentation in value.h. */
1758 compile_internalvar_to_ax (struct internalvar
*var
,
1759 struct agent_expr
*expr
,
1760 struct axs_value
*value
)
1762 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1763 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1766 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1767 var
->u
.make_value
.data
);
1771 /* Look up an internal variable with name NAME. NAME should not
1772 normally include a dollar sign.
1774 If the specified internal variable does not exist,
1775 one is created, with a void value. */
1777 struct internalvar
*
1778 lookup_internalvar (const char *name
)
1780 struct internalvar
*var
;
1782 var
= lookup_only_internalvar (name
);
1786 return create_internalvar (name
);
1789 /* Return current value of internal variable VAR. For variables that
1790 are not inherently typed, use a value type appropriate for GDBARCH. */
1793 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1796 struct trace_state_variable
*tsv
;
1798 /* If there is a trace state variable of the same name, assume that
1799 is what we really want to see. */
1800 tsv
= find_trace_state_variable (var
->name
);
1803 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1805 if (tsv
->value_known
)
1806 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1809 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1815 case INTERNALVAR_VOID
:
1816 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1819 case INTERNALVAR_FUNCTION
:
1820 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1823 case INTERNALVAR_INTEGER
:
1824 if (!var
->u
.integer
.type
)
1825 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1826 var
->u
.integer
.val
);
1828 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1831 case INTERNALVAR_STRING
:
1832 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1833 builtin_type (gdbarch
)->builtin_char
);
1836 case INTERNALVAR_VALUE
:
1837 val
= value_copy (var
->u
.value
);
1838 if (value_lazy (val
))
1839 value_fetch_lazy (val
);
1842 case INTERNALVAR_MAKE_VALUE
:
1843 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
1844 var
->u
.make_value
.data
);
1848 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1851 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1852 on this value go back to affect the original internal variable.
1854 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1855 no underlying modifyable state in the internal variable.
1857 Likewise, if the variable's value is a computed lvalue, we want
1858 references to it to produce another computed lvalue, where
1859 references and assignments actually operate through the
1860 computed value's functions.
1862 This means that internal variables with computed values
1863 behave a little differently from other internal variables:
1864 assignments to them don't just replace the previous value
1865 altogether. At the moment, this seems like the behavior we
1868 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1869 && val
->lval
!= lval_computed
)
1871 VALUE_LVAL (val
) = lval_internalvar
;
1872 VALUE_INTERNALVAR (val
) = var
;
1879 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1881 if (var
->kind
== INTERNALVAR_INTEGER
)
1883 *result
= var
->u
.integer
.val
;
1887 if (var
->kind
== INTERNALVAR_VALUE
)
1889 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1891 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1893 *result
= value_as_long (var
->u
.value
);
1902 get_internalvar_function (struct internalvar
*var
,
1903 struct internal_function
**result
)
1907 case INTERNALVAR_FUNCTION
:
1908 *result
= var
->u
.fn
.function
;
1917 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1918 int bitsize
, struct value
*newval
)
1924 case INTERNALVAR_VALUE
:
1925 addr
= value_contents_writeable (var
->u
.value
);
1928 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1929 value_as_long (newval
), bitpos
, bitsize
);
1931 memcpy (addr
+ offset
, value_contents (newval
),
1932 TYPE_LENGTH (value_type (newval
)));
1936 /* We can never get a component of any other kind. */
1937 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1942 set_internalvar (struct internalvar
*var
, struct value
*val
)
1944 enum internalvar_kind new_kind
;
1945 union internalvar_data new_data
= { 0 };
1947 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1948 error (_("Cannot overwrite convenience function %s"), var
->name
);
1950 /* Prepare new contents. */
1951 switch (TYPE_CODE (check_typedef (value_type (val
))))
1953 case TYPE_CODE_VOID
:
1954 new_kind
= INTERNALVAR_VOID
;
1957 case TYPE_CODE_INTERNAL_FUNCTION
:
1958 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1959 new_kind
= INTERNALVAR_FUNCTION
;
1960 get_internalvar_function (VALUE_INTERNALVAR (val
),
1961 &new_data
.fn
.function
);
1962 /* Copies created here are never canonical. */
1966 new_kind
= INTERNALVAR_VALUE
;
1967 new_data
.value
= value_copy (val
);
1968 new_data
.value
->modifiable
= 1;
1970 /* Force the value to be fetched from the target now, to avoid problems
1971 later when this internalvar is referenced and the target is gone or
1973 if (value_lazy (new_data
.value
))
1974 value_fetch_lazy (new_data
.value
);
1976 /* Release the value from the value chain to prevent it from being
1977 deleted by free_all_values. From here on this function should not
1978 call error () until new_data is installed into the var->u to avoid
1980 release_value (new_data
.value
);
1984 /* Clean up old contents. */
1985 clear_internalvar (var
);
1988 var
->kind
= new_kind
;
1990 /* End code which must not call error(). */
1994 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1996 /* Clean up old contents. */
1997 clear_internalvar (var
);
1999 var
->kind
= INTERNALVAR_INTEGER
;
2000 var
->u
.integer
.type
= NULL
;
2001 var
->u
.integer
.val
= l
;
2005 set_internalvar_string (struct internalvar
*var
, const char *string
)
2007 /* Clean up old contents. */
2008 clear_internalvar (var
);
2010 var
->kind
= INTERNALVAR_STRING
;
2011 var
->u
.string
= xstrdup (string
);
2015 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2017 /* Clean up old contents. */
2018 clear_internalvar (var
);
2020 var
->kind
= INTERNALVAR_FUNCTION
;
2021 var
->u
.fn
.function
= f
;
2022 var
->u
.fn
.canonical
= 1;
2023 /* Variables installed here are always the canonical version. */
2027 clear_internalvar (struct internalvar
*var
)
2029 /* Clean up old contents. */
2032 case INTERNALVAR_VALUE
:
2033 value_free (var
->u
.value
);
2036 case INTERNALVAR_STRING
:
2037 xfree (var
->u
.string
);
2040 case INTERNALVAR_MAKE_VALUE
:
2041 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2042 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2049 /* Reset to void kind. */
2050 var
->kind
= INTERNALVAR_VOID
;
2054 internalvar_name (struct internalvar
*var
)
2059 static struct internal_function
*
2060 create_internal_function (const char *name
,
2061 internal_function_fn handler
, void *cookie
)
2063 struct internal_function
*ifn
= XNEW (struct internal_function
);
2065 ifn
->name
= xstrdup (name
);
2066 ifn
->handler
= handler
;
2067 ifn
->cookie
= cookie
;
2072 value_internal_function_name (struct value
*val
)
2074 struct internal_function
*ifn
;
2077 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2078 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2079 gdb_assert (result
);
2085 call_internal_function (struct gdbarch
*gdbarch
,
2086 const struct language_defn
*language
,
2087 struct value
*func
, int argc
, struct value
**argv
)
2089 struct internal_function
*ifn
;
2092 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2093 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2094 gdb_assert (result
);
2096 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2099 /* The 'function' command. This does nothing -- it is just a
2100 placeholder to let "help function NAME" work. This is also used as
2101 the implementation of the sub-command that is created when
2102 registering an internal function. */
2104 function_command (char *command
, int from_tty
)
2109 /* Clean up if an internal function's command is destroyed. */
2111 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2117 /* Add a new internal function. NAME is the name of the function; DOC
2118 is a documentation string describing the function. HANDLER is
2119 called when the function is invoked. COOKIE is an arbitrary
2120 pointer which is passed to HANDLER and is intended for "user
2123 add_internal_function (const char *name
, const char *doc
,
2124 internal_function_fn handler
, void *cookie
)
2126 struct cmd_list_element
*cmd
;
2127 struct internal_function
*ifn
;
2128 struct internalvar
*var
= lookup_internalvar (name
);
2130 ifn
= create_internal_function (name
, handler
, cookie
);
2131 set_internalvar_function (var
, ifn
);
2133 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2135 cmd
->destroyer
= function_destroyer
;
2138 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2139 prevent cycles / duplicates. */
2142 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2143 htab_t copied_types
)
2145 if (TYPE_OBJFILE (value
->type
) == objfile
)
2146 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2148 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2149 value
->enclosing_type
= copy_type_recursive (objfile
,
2150 value
->enclosing_type
,
2154 /* Likewise for internal variable VAR. */
2157 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2158 htab_t copied_types
)
2162 case INTERNALVAR_INTEGER
:
2163 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2165 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2168 case INTERNALVAR_VALUE
:
2169 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2174 /* Update the internal variables and value history when OBJFILE is
2175 discarded; we must copy the types out of the objfile. New global types
2176 will be created for every convenience variable which currently points to
2177 this objfile's types, and the convenience variables will be adjusted to
2178 use the new global types. */
2181 preserve_values (struct objfile
*objfile
)
2183 htab_t copied_types
;
2184 struct value_history_chunk
*cur
;
2185 struct internalvar
*var
;
2188 /* Create the hash table. We allocate on the objfile's obstack, since
2189 it is soon to be deleted. */
2190 copied_types
= create_copied_types_hash (objfile
);
2192 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2193 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2195 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2197 for (var
= internalvars
; var
; var
= var
->next
)
2198 preserve_one_internalvar (var
, objfile
, copied_types
);
2200 preserve_python_values (objfile
, copied_types
);
2202 htab_delete (copied_types
);
2206 show_convenience (char *ignore
, int from_tty
)
2208 struct gdbarch
*gdbarch
= get_current_arch ();
2209 struct internalvar
*var
;
2211 struct value_print_options opts
;
2213 get_user_print_options (&opts
);
2214 for (var
= internalvars
; var
; var
= var
->next
)
2216 volatile struct gdb_exception ex
;
2222 printf_filtered (("$%s = "), var
->name
);
2224 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2228 val
= value_of_internalvar (gdbarch
, var
);
2229 value_print (val
, gdb_stdout
, &opts
);
2232 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2233 printf_filtered (("\n"));
2236 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2237 "Convenience variables have "
2238 "names starting with \"$\";\n"
2239 "use \"set\" as in \"set "
2240 "$foo = 5\" to define them.\n"));
2243 /* Extract a value as a C number (either long or double).
2244 Knows how to convert fixed values to double, or
2245 floating values to long.
2246 Does not deallocate the value. */
2249 value_as_long (struct value
*val
)
2251 /* This coerces arrays and functions, which is necessary (e.g.
2252 in disassemble_command). It also dereferences references, which
2253 I suspect is the most logical thing to do. */
2254 val
= coerce_array (val
);
2255 return unpack_long (value_type (val
), value_contents (val
));
2259 value_as_double (struct value
*val
)
2264 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2266 error (_("Invalid floating value found in program."));
2270 /* Extract a value as a C pointer. Does not deallocate the value.
2271 Note that val's type may not actually be a pointer; value_as_long
2272 handles all the cases. */
2274 value_as_address (struct value
*val
)
2276 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2278 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2279 whether we want this to be true eventually. */
2281 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2282 non-address (e.g. argument to "signal", "info break", etc.), or
2283 for pointers to char, in which the low bits *are* significant. */
2284 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2287 /* There are several targets (IA-64, PowerPC, and others) which
2288 don't represent pointers to functions as simply the address of
2289 the function's entry point. For example, on the IA-64, a
2290 function pointer points to a two-word descriptor, generated by
2291 the linker, which contains the function's entry point, and the
2292 value the IA-64 "global pointer" register should have --- to
2293 support position-independent code. The linker generates
2294 descriptors only for those functions whose addresses are taken.
2296 On such targets, it's difficult for GDB to convert an arbitrary
2297 function address into a function pointer; it has to either find
2298 an existing descriptor for that function, or call malloc and
2299 build its own. On some targets, it is impossible for GDB to
2300 build a descriptor at all: the descriptor must contain a jump
2301 instruction; data memory cannot be executed; and code memory
2304 Upon entry to this function, if VAL is a value of type `function'
2305 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2306 value_address (val) is the address of the function. This is what
2307 you'll get if you evaluate an expression like `main'. The call
2308 to COERCE_ARRAY below actually does all the usual unary
2309 conversions, which includes converting values of type `function'
2310 to `pointer to function'. This is the challenging conversion
2311 discussed above. Then, `unpack_long' will convert that pointer
2312 back into an address.
2314 So, suppose the user types `disassemble foo' on an architecture
2315 with a strange function pointer representation, on which GDB
2316 cannot build its own descriptors, and suppose further that `foo'
2317 has no linker-built descriptor. The address->pointer conversion
2318 will signal an error and prevent the command from running, even
2319 though the next step would have been to convert the pointer
2320 directly back into the same address.
2322 The following shortcut avoids this whole mess. If VAL is a
2323 function, just return its address directly. */
2324 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2325 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2326 return value_address (val
);
2328 val
= coerce_array (val
);
2330 /* Some architectures (e.g. Harvard), map instruction and data
2331 addresses onto a single large unified address space. For
2332 instance: An architecture may consider a large integer in the
2333 range 0x10000000 .. 0x1000ffff to already represent a data
2334 addresses (hence not need a pointer to address conversion) while
2335 a small integer would still need to be converted integer to
2336 pointer to address. Just assume such architectures handle all
2337 integer conversions in a single function. */
2341 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2342 must admonish GDB hackers to make sure its behavior matches the
2343 compiler's, whenever possible.
2345 In general, I think GDB should evaluate expressions the same way
2346 the compiler does. When the user copies an expression out of
2347 their source code and hands it to a `print' command, they should
2348 get the same value the compiler would have computed. Any
2349 deviation from this rule can cause major confusion and annoyance,
2350 and needs to be justified carefully. In other words, GDB doesn't
2351 really have the freedom to do these conversions in clever and
2354 AndrewC pointed out that users aren't complaining about how GDB
2355 casts integers to pointers; they are complaining that they can't
2356 take an address from a disassembly listing and give it to `x/i'.
2357 This is certainly important.
2359 Adding an architecture method like integer_to_address() certainly
2360 makes it possible for GDB to "get it right" in all circumstances
2361 --- the target has complete control over how things get done, so
2362 people can Do The Right Thing for their target without breaking
2363 anyone else. The standard doesn't specify how integers get
2364 converted to pointers; usually, the ABI doesn't either, but
2365 ABI-specific code is a more reasonable place to handle it. */
2367 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2368 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2369 && gdbarch_integer_to_address_p (gdbarch
))
2370 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2371 value_contents (val
));
2373 return unpack_long (value_type (val
), value_contents (val
));
2377 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2378 as a long, or as a double, assuming the raw data is described
2379 by type TYPE. Knows how to convert different sizes of values
2380 and can convert between fixed and floating point. We don't assume
2381 any alignment for the raw data. Return value is in host byte order.
2383 If you want functions and arrays to be coerced to pointers, and
2384 references to be dereferenced, call value_as_long() instead.
2386 C++: It is assumed that the front-end has taken care of
2387 all matters concerning pointers to members. A pointer
2388 to member which reaches here is considered to be equivalent
2389 to an INT (or some size). After all, it is only an offset. */
2392 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2394 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2395 enum type_code code
= TYPE_CODE (type
);
2396 int len
= TYPE_LENGTH (type
);
2397 int nosign
= TYPE_UNSIGNED (type
);
2401 case TYPE_CODE_TYPEDEF
:
2402 return unpack_long (check_typedef (type
), valaddr
);
2403 case TYPE_CODE_ENUM
:
2404 case TYPE_CODE_FLAGS
:
2405 case TYPE_CODE_BOOL
:
2407 case TYPE_CODE_CHAR
:
2408 case TYPE_CODE_RANGE
:
2409 case TYPE_CODE_MEMBERPTR
:
2411 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2413 return extract_signed_integer (valaddr
, len
, byte_order
);
2416 return extract_typed_floating (valaddr
, type
);
2418 case TYPE_CODE_DECFLOAT
:
2419 /* libdecnumber has a function to convert from decimal to integer, but
2420 it doesn't work when the decimal number has a fractional part. */
2421 return decimal_to_doublest (valaddr
, len
, byte_order
);
2425 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2426 whether we want this to be true eventually. */
2427 return extract_typed_address (valaddr
, type
);
2430 error (_("Value can't be converted to integer."));
2432 return 0; /* Placate lint. */
2435 /* Return a double value from the specified type and address.
2436 INVP points to an int which is set to 0 for valid value,
2437 1 for invalid value (bad float format). In either case,
2438 the returned double is OK to use. Argument is in target
2439 format, result is in host format. */
2442 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2444 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2445 enum type_code code
;
2449 *invp
= 0; /* Assume valid. */
2450 CHECK_TYPEDEF (type
);
2451 code
= TYPE_CODE (type
);
2452 len
= TYPE_LENGTH (type
);
2453 nosign
= TYPE_UNSIGNED (type
);
2454 if (code
== TYPE_CODE_FLT
)
2456 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2457 floating-point value was valid (using the macro
2458 INVALID_FLOAT). That test/macro have been removed.
2460 It turns out that only the VAX defined this macro and then
2461 only in a non-portable way. Fixing the portability problem
2462 wouldn't help since the VAX floating-point code is also badly
2463 bit-rotten. The target needs to add definitions for the
2464 methods gdbarch_float_format and gdbarch_double_format - these
2465 exactly describe the target floating-point format. The
2466 problem here is that the corresponding floatformat_vax_f and
2467 floatformat_vax_d values these methods should be set to are
2468 also not defined either. Oops!
2470 Hopefully someone will add both the missing floatformat
2471 definitions and the new cases for floatformat_is_valid (). */
2473 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2479 return extract_typed_floating (valaddr
, type
);
2481 else if (code
== TYPE_CODE_DECFLOAT
)
2482 return decimal_to_doublest (valaddr
, len
, byte_order
);
2485 /* Unsigned -- be sure we compensate for signed LONGEST. */
2486 return (ULONGEST
) unpack_long (type
, valaddr
);
2490 /* Signed -- we are OK with unpack_long. */
2491 return unpack_long (type
, valaddr
);
2495 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2496 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2497 We don't assume any alignment for the raw data. Return value is in
2500 If you want functions and arrays to be coerced to pointers, and
2501 references to be dereferenced, call value_as_address() instead.
2503 C++: It is assumed that the front-end has taken care of
2504 all matters concerning pointers to members. A pointer
2505 to member which reaches here is considered to be equivalent
2506 to an INT (or some size). After all, it is only an offset. */
2509 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2511 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2512 whether we want this to be true eventually. */
2513 return unpack_long (type
, valaddr
);
2517 /* Get the value of the FIELDNO'th field (which must be static) of
2518 TYPE. Return NULL if the field doesn't exist or has been
2522 value_static_field (struct type
*type
, int fieldno
)
2524 struct value
*retval
;
2526 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2528 case FIELD_LOC_KIND_PHYSADDR
:
2529 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2530 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2532 case FIELD_LOC_KIND_PHYSNAME
:
2534 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2535 /* TYPE_FIELD_NAME (type, fieldno); */
2536 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2540 /* With some compilers, e.g. HP aCC, static data members are
2541 reported as non-debuggable symbols. */
2542 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2549 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2550 SYMBOL_VALUE_ADDRESS (msym
));
2554 retval
= value_of_variable (sym
, NULL
);
2558 gdb_assert_not_reached ("unexpected field location kind");
2564 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2565 You have to be careful here, since the size of the data area for the value
2566 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2567 than the old enclosing type, you have to allocate more space for the
2571 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2573 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2575 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2577 val
->enclosing_type
= new_encl_type
;
2580 /* Given a value ARG1 (offset by OFFSET bytes)
2581 of a struct or union type ARG_TYPE,
2582 extract and return the value of one of its (non-static) fields.
2583 FIELDNO says which field. */
2586 value_primitive_field (struct value
*arg1
, int offset
,
2587 int fieldno
, struct type
*arg_type
)
2592 CHECK_TYPEDEF (arg_type
);
2593 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2595 /* Call check_typedef on our type to make sure that, if TYPE
2596 is a TYPE_CODE_TYPEDEF, its length is set to the length
2597 of the target type instead of zero. However, we do not
2598 replace the typedef type by the target type, because we want
2599 to keep the typedef in order to be able to print the type
2600 description correctly. */
2601 check_typedef (type
);
2603 if (value_optimized_out (arg1
))
2604 v
= allocate_optimized_out_value (type
);
2605 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2607 /* Handle packed fields.
2609 Create a new value for the bitfield, with bitpos and bitsize
2610 set. If possible, arrange offset and bitpos so that we can
2611 do a single aligned read of the size of the containing type.
2612 Otherwise, adjust offset to the byte containing the first
2613 bit. Assume that the address, offset, and embedded offset
2614 are sufficiently aligned. */
2616 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2617 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2619 v
= allocate_value_lazy (type
);
2620 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2621 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2622 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2623 v
->bitpos
= bitpos
% container_bitsize
;
2625 v
->bitpos
= bitpos
% 8;
2626 v
->offset
= (value_embedded_offset (arg1
)
2628 + (bitpos
- v
->bitpos
) / 8);
2630 value_incref (v
->parent
);
2631 if (!value_lazy (arg1
))
2632 value_fetch_lazy (v
);
2634 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2636 /* This field is actually a base subobject, so preserve the
2637 entire object's contents for later references to virtual
2641 /* Lazy register values with offsets are not supported. */
2642 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2643 value_fetch_lazy (arg1
);
2645 /* We special case virtual inheritance here because this
2646 requires access to the contents, which we would rather avoid
2647 for references to ordinary fields of unavailable values. */
2648 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2649 boffset
= baseclass_offset (arg_type
, fieldno
,
2650 value_contents (arg1
),
2651 value_embedded_offset (arg1
),
2652 value_address (arg1
),
2655 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2657 if (value_lazy (arg1
))
2658 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2661 v
= allocate_value (value_enclosing_type (arg1
));
2662 value_contents_copy_raw (v
, 0, arg1
, 0,
2663 TYPE_LENGTH (value_enclosing_type (arg1
)));
2666 v
->offset
= value_offset (arg1
);
2667 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2671 /* Plain old data member */
2672 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2674 /* Lazy register values with offsets are not supported. */
2675 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2676 value_fetch_lazy (arg1
);
2678 if (value_lazy (arg1
))
2679 v
= allocate_value_lazy (type
);
2682 v
= allocate_value (type
);
2683 value_contents_copy_raw (v
, value_embedded_offset (v
),
2684 arg1
, value_embedded_offset (arg1
) + offset
,
2685 TYPE_LENGTH (type
));
2687 v
->offset
= (value_offset (arg1
) + offset
2688 + value_embedded_offset (arg1
));
2690 set_value_component_location (v
, arg1
);
2691 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2692 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2696 /* Given a value ARG1 of a struct or union type,
2697 extract and return the value of one of its (non-static) fields.
2698 FIELDNO says which field. */
2701 value_field (struct value
*arg1
, int fieldno
)
2703 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2706 /* Return a non-virtual function as a value.
2707 F is the list of member functions which contains the desired method.
2708 J is an index into F which provides the desired method.
2710 We only use the symbol for its address, so be happy with either a
2711 full symbol or a minimal symbol. */
2714 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2715 int j
, struct type
*type
,
2719 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2720 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2722 struct minimal_symbol
*msym
;
2724 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2731 gdb_assert (sym
== NULL
);
2732 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2737 v
= allocate_value (ftype
);
2740 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2744 /* The minimal symbol might point to a function descriptor;
2745 resolve it to the actual code address instead. */
2746 struct objfile
*objfile
= msymbol_objfile (msym
);
2747 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2749 set_value_address (v
,
2750 gdbarch_convert_from_func_ptr_addr
2751 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2756 if (type
!= value_type (*arg1p
))
2757 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2758 value_addr (*arg1p
)));
2760 /* Move the `this' pointer according to the offset.
2761 VALUE_OFFSET (*arg1p) += offset; */
2769 /* Helper function for both unpack_value_bits_as_long and
2770 unpack_bits_as_long. See those functions for more details on the
2771 interface; the only difference is that this function accepts either
2772 a NULL or a non-NULL ORIGINAL_VALUE. */
2775 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2776 int embedded_offset
, int bitpos
, int bitsize
,
2777 const struct value
*original_value
,
2780 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2787 /* Read the minimum number of bytes required; there may not be
2788 enough bytes to read an entire ULONGEST. */
2789 CHECK_TYPEDEF (field_type
);
2791 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2793 bytes_read
= TYPE_LENGTH (field_type
);
2795 read_offset
= bitpos
/ 8;
2797 if (original_value
!= NULL
2798 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2802 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2803 bytes_read
, byte_order
);
2805 /* Extract bits. See comment above. */
2807 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2808 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2810 lsbcount
= (bitpos
% 8);
2813 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2814 If the field is signed, and is negative, then sign extend. */
2816 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2818 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2820 if (!TYPE_UNSIGNED (field_type
))
2822 if (val
& (valmask
^ (valmask
>> 1)))
2833 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2834 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2835 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2836 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2839 Returns false if the value contents are unavailable, otherwise
2840 returns true, indicating a valid value has been stored in *RESULT.
2842 Extracting bits depends on endianness of the machine. Compute the
2843 number of least significant bits to discard. For big endian machines,
2844 we compute the total number of bits in the anonymous object, subtract
2845 off the bit count from the MSB of the object to the MSB of the
2846 bitfield, then the size of the bitfield, which leaves the LSB discard
2847 count. For little endian machines, the discard count is simply the
2848 number of bits from the LSB of the anonymous object to the LSB of the
2851 If the field is signed, we also do sign extension. */
2854 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2855 int embedded_offset
, int bitpos
, int bitsize
,
2856 const struct value
*original_value
,
2859 gdb_assert (original_value
!= NULL
);
2861 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2862 bitpos
, bitsize
, original_value
, result
);
2866 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2867 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2868 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2872 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2873 int embedded_offset
, int fieldno
,
2874 const struct value
*val
, LONGEST
*result
)
2876 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2877 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2878 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2880 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2881 bitpos
, bitsize
, val
,
2885 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2886 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2887 ORIGINAL_VALUE, which must not be NULL. See
2888 unpack_value_bits_as_long for more details. */
2891 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2892 int embedded_offset
, int fieldno
,
2893 const struct value
*val
, LONGEST
*result
)
2895 gdb_assert (val
!= NULL
);
2897 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2898 fieldno
, val
, result
);
2901 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2902 object at VALADDR. See unpack_value_bits_as_long for more details.
2903 This function differs from unpack_value_field_as_long in that it
2904 operates without a struct value object. */
2907 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2911 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2915 /* Return a new value with type TYPE, which is FIELDNO field of the
2916 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2917 of VAL. If the VAL's contents required to extract the bitfield
2918 from are unavailable, the new value is correspondingly marked as
2922 value_field_bitfield (struct type
*type
, int fieldno
,
2923 const gdb_byte
*valaddr
,
2924 int embedded_offset
, const struct value
*val
)
2928 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2931 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2932 struct value
*retval
= allocate_value (field_type
);
2933 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2938 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2942 /* Modify the value of a bitfield. ADDR points to a block of memory in
2943 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2944 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2945 indicate which bits (in target bit order) comprise the bitfield.
2946 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2947 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2950 modify_field (struct type
*type
, gdb_byte
*addr
,
2951 LONGEST fieldval
, int bitpos
, int bitsize
)
2953 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2955 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2958 /* Normalize BITPOS. */
2962 /* If a negative fieldval fits in the field in question, chop
2963 off the sign extension bits. */
2964 if ((~fieldval
& ~(mask
>> 1)) == 0)
2967 /* Warn if value is too big to fit in the field in question. */
2968 if (0 != (fieldval
& ~mask
))
2970 /* FIXME: would like to include fieldval in the message, but
2971 we don't have a sprintf_longest. */
2972 warning (_("Value does not fit in %d bits."), bitsize
);
2974 /* Truncate it, otherwise adjoining fields may be corrupted. */
2978 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2979 false valgrind reports. */
2981 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2982 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2984 /* Shifting for bit field depends on endianness of the target machine. */
2985 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2986 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2988 oword
&= ~(mask
<< bitpos
);
2989 oword
|= fieldval
<< bitpos
;
2991 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2994 /* Pack NUM into BUF using a target format of TYPE. */
2997 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2999 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3002 type
= check_typedef (type
);
3003 len
= TYPE_LENGTH (type
);
3005 switch (TYPE_CODE (type
))
3008 case TYPE_CODE_CHAR
:
3009 case TYPE_CODE_ENUM
:
3010 case TYPE_CODE_FLAGS
:
3011 case TYPE_CODE_BOOL
:
3012 case TYPE_CODE_RANGE
:
3013 case TYPE_CODE_MEMBERPTR
:
3014 store_signed_integer (buf
, len
, byte_order
, num
);
3019 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3023 error (_("Unexpected type (%d) encountered for integer constant."),
3029 /* Pack NUM into BUF using a target format of TYPE. */
3032 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3035 enum bfd_endian byte_order
;
3037 type
= check_typedef (type
);
3038 len
= TYPE_LENGTH (type
);
3039 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3041 switch (TYPE_CODE (type
))
3044 case TYPE_CODE_CHAR
:
3045 case TYPE_CODE_ENUM
:
3046 case TYPE_CODE_FLAGS
:
3047 case TYPE_CODE_BOOL
:
3048 case TYPE_CODE_RANGE
:
3049 case TYPE_CODE_MEMBERPTR
:
3050 store_unsigned_integer (buf
, len
, byte_order
, num
);
3055 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3059 error (_("Unexpected type (%d) encountered "
3060 "for unsigned integer constant."),
3066 /* Convert C numbers into newly allocated values. */
3069 value_from_longest (struct type
*type
, LONGEST num
)
3071 struct value
*val
= allocate_value (type
);
3073 pack_long (value_contents_raw (val
), type
, num
);
3078 /* Convert C unsigned numbers into newly allocated values. */
3081 value_from_ulongest (struct type
*type
, ULONGEST num
)
3083 struct value
*val
= allocate_value (type
);
3085 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3091 /* Create a value representing a pointer of type TYPE to the address
3094 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3096 struct value
*val
= allocate_value (type
);
3098 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3103 /* Create a value of type TYPE whose contents come from VALADDR, if it
3104 is non-null, and whose memory address (in the inferior) is
3108 value_from_contents_and_address (struct type
*type
,
3109 const gdb_byte
*valaddr
,
3114 if (valaddr
== NULL
)
3115 v
= allocate_value_lazy (type
);
3118 v
= allocate_value (type
);
3119 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3121 set_value_address (v
, address
);
3122 VALUE_LVAL (v
) = lval_memory
;
3126 /* Create a value of type TYPE holding the contents CONTENTS.
3127 The new value is `not_lval'. */
3130 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3132 struct value
*result
;
3134 result
= allocate_value (type
);
3135 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3140 value_from_double (struct type
*type
, DOUBLEST num
)
3142 struct value
*val
= allocate_value (type
);
3143 struct type
*base_type
= check_typedef (type
);
3144 enum type_code code
= TYPE_CODE (base_type
);
3146 if (code
== TYPE_CODE_FLT
)
3148 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3151 error (_("Unexpected type encountered for floating constant."));
3157 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3159 struct value
*val
= allocate_value (type
);
3161 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3165 /* Extract a value from the history file. Input will be of the form
3166 $digits or $$digits. See block comment above 'write_dollar_variable'
3170 value_from_history_ref (char *h
, char **endp
)
3182 /* Find length of numeral string. */
3183 for (; isdigit (h
[len
]); len
++)
3186 /* Make sure numeral string is not part of an identifier. */
3187 if (h
[len
] == '_' || isalpha (h
[len
]))
3190 /* Now collect the index value. */
3195 /* For some bizarre reason, "$$" is equivalent to "$$1",
3196 rather than to "$$0" as it ought to be! */
3201 index
= -strtol (&h
[2], endp
, 10);
3207 /* "$" is equivalent to "$0". */
3212 index
= strtol (&h
[1], endp
, 10);
3215 return access_value_history (index
);
3219 coerce_ref_if_computed (const struct value
*arg
)
3221 const struct lval_funcs
*funcs
;
3223 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3226 if (value_lval_const (arg
) != lval_computed
)
3229 funcs
= value_computed_funcs (arg
);
3230 if (funcs
->coerce_ref
== NULL
)
3233 return funcs
->coerce_ref (arg
);
3236 /* Look at value.h for description. */
3239 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3240 struct type
*original_type
,
3241 struct value
*original_value
)
3243 /* Re-adjust type. */
3244 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3246 /* Add embedding info. */
3247 set_value_enclosing_type (value
, enc_type
);
3248 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3250 /* We may be pointing to an object of some derived type. */
3251 return value_full_object (value
, NULL
, 0, 0, 0);
3255 coerce_ref (struct value
*arg
)
3257 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3258 struct value
*retval
;
3259 struct type
*enc_type
;
3261 retval
= coerce_ref_if_computed (arg
);
3265 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3268 enc_type
= check_typedef (value_enclosing_type (arg
));
3269 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3271 retval
= value_at_lazy (enc_type
,
3272 unpack_pointer (value_type (arg
),
3273 value_contents (arg
)));
3274 return readjust_indirect_value_type (retval
, enc_type
,
3275 value_type_arg_tmp
, arg
);
3279 coerce_array (struct value
*arg
)
3283 arg
= coerce_ref (arg
);
3284 type
= check_typedef (value_type (arg
));
3286 switch (TYPE_CODE (type
))
3288 case TYPE_CODE_ARRAY
:
3289 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3290 arg
= value_coerce_array (arg
);
3292 case TYPE_CODE_FUNC
:
3293 arg
= value_coerce_function (arg
);
3300 /* Return true if the function returning the specified type is using
3301 the convention of returning structures in memory (passing in the
3302 address as a hidden first parameter). */
3305 using_struct_return (struct gdbarch
*gdbarch
,
3306 struct type
*func_type
, struct type
*value_type
)
3308 enum type_code code
= TYPE_CODE (value_type
);
3310 if (code
== TYPE_CODE_ERROR
)
3311 error (_("Function return type unknown."));
3313 if (code
== TYPE_CODE_VOID
)
3314 /* A void return value is never in memory. See also corresponding
3315 code in "print_return_value". */
3318 /* Probe the architecture for the return-value convention. */
3319 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3321 != RETURN_VALUE_REGISTER_CONVENTION
);
3324 /* Set the initialized field in a value struct. */
3327 set_value_initialized (struct value
*val
, int status
)
3329 val
->initialized
= status
;
3332 /* Return the initialized field in a value struct. */
3335 value_initialized (struct value
*val
)
3337 return val
->initialized
;
3341 _initialize_values (void)
3343 add_cmd ("convenience", no_class
, show_convenience
, _("\
3344 Debugger convenience (\"$foo\") variables.\n\
3345 These variables are created when you assign them values;\n\
3346 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3348 A few convenience variables are given values automatically:\n\
3349 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3350 \"$__\" holds the contents of the last address examined with \"x\"."),
3353 add_cmd ("values", no_set_class
, show_values
, _("\
3354 Elements of value history around item number IDX (or last ten)."),
3357 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3358 Initialize a convenience variable if necessary.\n\
3359 init-if-undefined VARIABLE = EXPRESSION\n\
3360 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3361 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3362 VARIABLE is already initialized."));
3364 add_prefix_cmd ("function", no_class
, function_command
, _("\
3365 Placeholder command for showing help on convenience functions."),
3366 &functionlist
, "function ", 0, &cmdlist
);