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
;
810 value_contents_raw (struct value
*value
)
812 allocate_value_contents (value
);
813 return value
->contents
+ value
->embedded_offset
;
817 value_contents_all_raw (struct value
*value
)
819 allocate_value_contents (value
);
820 return value
->contents
;
824 value_enclosing_type (struct value
*value
)
826 return value
->enclosing_type
;
830 require_not_optimized_out (const struct value
*value
)
832 if (value
->optimized_out
)
833 error (_("value has been optimized out"));
837 require_available (const struct value
*value
)
839 if (!VEC_empty (range_s
, value
->unavailable
))
840 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
844 value_contents_for_printing (struct value
*value
)
847 value_fetch_lazy (value
);
848 return value
->contents
;
852 value_contents_for_printing_const (const struct value
*value
)
854 gdb_assert (!value
->lazy
);
855 return value
->contents
;
859 value_contents_all (struct value
*value
)
861 const gdb_byte
*result
= value_contents_for_printing (value
);
862 require_not_optimized_out (value
);
863 require_available (value
);
867 /* Copy LENGTH bytes of SRC value's (all) contents
868 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
869 contents, starting at DST_OFFSET. If unavailable contents are
870 being copied from SRC, the corresponding DST contents are marked
871 unavailable accordingly. Neither DST nor SRC may be lazy
874 It is assumed the contents of DST in the [DST_OFFSET,
875 DST_OFFSET+LENGTH) range are wholly available. */
878 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
879 struct value
*src
, int src_offset
, int length
)
884 /* A lazy DST would make that this copy operation useless, since as
885 soon as DST's contents were un-lazied (by a later value_contents
886 call, say), the contents would be overwritten. A lazy SRC would
887 mean we'd be copying garbage. */
888 gdb_assert (!dst
->lazy
&& !src
->lazy
);
890 /* The overwritten DST range gets unavailability ORed in, not
891 replaced. Make sure to remember to implement replacing if it
892 turns out actually necessary. */
893 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
896 memcpy (value_contents_all_raw (dst
) + dst_offset
,
897 value_contents_all_raw (src
) + src_offset
,
900 /* Copy the meta-data, adjusted. */
901 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
905 l
= max (r
->offset
, src_offset
);
906 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
909 mark_value_bytes_unavailable (dst
,
910 dst_offset
+ (l
- src_offset
),
915 /* Copy LENGTH bytes of SRC value's (all) contents
916 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
917 (all) contents, starting at DST_OFFSET. If unavailable contents
918 are being copied from SRC, the corresponding DST contents are
919 marked unavailable accordingly. DST must not be lazy. If SRC is
920 lazy, it will be fetched now. If SRC is not valid (is optimized
921 out), an error is thrown.
923 It is assumed the contents of DST in the [DST_OFFSET,
924 DST_OFFSET+LENGTH) range are wholly available. */
927 value_contents_copy (struct value
*dst
, int dst_offset
,
928 struct value
*src
, int src_offset
, int length
)
930 require_not_optimized_out (src
);
933 value_fetch_lazy (src
);
935 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
939 value_lazy (struct value
*value
)
945 set_value_lazy (struct value
*value
, int val
)
951 value_stack (struct value
*value
)
957 set_value_stack (struct value
*value
, int val
)
963 value_contents (struct value
*value
)
965 const gdb_byte
*result
= value_contents_writeable (value
);
966 require_not_optimized_out (value
);
967 require_available (value
);
972 value_contents_writeable (struct value
*value
)
975 value_fetch_lazy (value
);
976 return value_contents_raw (value
);
979 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
980 this function is different from value_equal; in C the operator ==
981 can return 0 even if the two values being compared are equal. */
984 value_contents_equal (struct value
*val1
, struct value
*val2
)
990 type1
= check_typedef (value_type (val1
));
991 type2
= check_typedef (value_type (val2
));
992 len
= TYPE_LENGTH (type1
);
993 if (len
!= TYPE_LENGTH (type2
))
996 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
1000 value_optimized_out (struct value
*value
)
1002 return value
->optimized_out
;
1006 set_value_optimized_out (struct value
*value
, int val
)
1008 value
->optimized_out
= val
;
1012 value_entirely_optimized_out (const struct value
*value
)
1014 if (!value
->optimized_out
)
1016 if (value
->lval
!= lval_computed
1017 || !value
->location
.computed
.funcs
->check_any_valid
)
1019 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1023 value_bits_valid (const struct value
*value
, int offset
, int length
)
1025 if (!value
->optimized_out
)
1027 if (value
->lval
!= lval_computed
1028 || !value
->location
.computed
.funcs
->check_validity
)
1030 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1035 value_bits_synthetic_pointer (const struct value
*value
,
1036 int offset
, int length
)
1038 if (value
->lval
!= lval_computed
1039 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1041 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1047 value_embedded_offset (struct value
*value
)
1049 return value
->embedded_offset
;
1053 set_value_embedded_offset (struct value
*value
, int val
)
1055 value
->embedded_offset
= val
;
1059 value_pointed_to_offset (struct value
*value
)
1061 return value
->pointed_to_offset
;
1065 set_value_pointed_to_offset (struct value
*value
, int val
)
1067 value
->pointed_to_offset
= val
;
1070 const struct lval_funcs
*
1071 value_computed_funcs (const struct value
*v
)
1073 gdb_assert (value_lval_const (v
) == lval_computed
);
1075 return v
->location
.computed
.funcs
;
1079 value_computed_closure (const struct value
*v
)
1081 gdb_assert (v
->lval
== lval_computed
);
1083 return v
->location
.computed
.closure
;
1087 deprecated_value_lval_hack (struct value
*value
)
1089 return &value
->lval
;
1093 value_lval_const (const struct value
*value
)
1099 value_address (const struct value
*value
)
1101 if (value
->lval
== lval_internalvar
1102 || value
->lval
== lval_internalvar_component
)
1104 return value
->location
.address
+ value
->offset
;
1108 value_raw_address (struct value
*value
)
1110 if (value
->lval
== lval_internalvar
1111 || value
->lval
== lval_internalvar_component
)
1113 return value
->location
.address
;
1117 set_value_address (struct value
*value
, CORE_ADDR addr
)
1119 gdb_assert (value
->lval
!= lval_internalvar
1120 && value
->lval
!= lval_internalvar_component
);
1121 value
->location
.address
= addr
;
1124 struct internalvar
**
1125 deprecated_value_internalvar_hack (struct value
*value
)
1127 return &value
->location
.internalvar
;
1131 deprecated_value_frame_id_hack (struct value
*value
)
1133 return &value
->frame_id
;
1137 deprecated_value_regnum_hack (struct value
*value
)
1139 return &value
->regnum
;
1143 deprecated_value_modifiable (struct value
*value
)
1145 return value
->modifiable
;
1148 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1150 value
->modifiable
= modifiable
;
1153 /* Return a mark in the value chain. All values allocated after the
1154 mark is obtained (except for those released) are subject to being freed
1155 if a subsequent value_free_to_mark is passed the mark. */
1162 /* Take a reference to VAL. VAL will not be deallocated until all
1163 references are released. */
1166 value_incref (struct value
*val
)
1168 val
->reference_count
++;
1171 /* Release a reference to VAL, which was acquired with value_incref.
1172 This function is also called to deallocate values from the value
1176 value_free (struct value
*val
)
1180 gdb_assert (val
->reference_count
> 0);
1181 val
->reference_count
--;
1182 if (val
->reference_count
> 0)
1185 /* If there's an associated parent value, drop our reference to
1187 if (val
->parent
!= NULL
)
1188 value_free (val
->parent
);
1190 if (VALUE_LVAL (val
) == lval_computed
)
1192 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1194 if (funcs
->free_closure
)
1195 funcs
->free_closure (val
);
1198 xfree (val
->contents
);
1199 VEC_free (range_s
, val
->unavailable
);
1204 /* Free all values allocated since MARK was obtained by value_mark
1205 (except for those released). */
1207 value_free_to_mark (struct value
*mark
)
1212 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1221 /* Free all the values that have been allocated (except for those released).
1222 Call after each command, successful or not.
1223 In practice this is called before each command, which is sufficient. */
1226 free_all_values (void)
1231 for (val
= all_values
; val
; val
= next
)
1241 /* Frees all the elements in a chain of values. */
1244 free_value_chain (struct value
*v
)
1250 next
= value_next (v
);
1255 /* Remove VAL from the chain all_values
1256 so it will not be freed automatically. */
1259 release_value (struct value
*val
)
1263 if (all_values
== val
)
1265 all_values
= val
->next
;
1271 for (v
= all_values
; v
; v
= v
->next
)
1275 v
->next
= val
->next
;
1283 /* If the value is not already released, release it.
1284 If the value is already released, increment its reference count.
1285 That is, this function ensures that the value is released from the
1286 value chain and that the caller owns a reference to it. */
1289 release_value_or_incref (struct value
*val
)
1294 release_value (val
);
1297 /* Release all values up to mark */
1299 value_release_to_mark (struct value
*mark
)
1304 for (val
= next
= all_values
; next
; next
= next
->next
)
1306 if (next
->next
== mark
)
1308 all_values
= next
->next
;
1318 /* Return a copy of the value ARG.
1319 It contains the same contents, for same memory address,
1320 but it's a different block of storage. */
1323 value_copy (struct value
*arg
)
1325 struct type
*encl_type
= value_enclosing_type (arg
);
1328 if (value_lazy (arg
))
1329 val
= allocate_value_lazy (encl_type
);
1331 val
= allocate_value (encl_type
);
1332 val
->type
= arg
->type
;
1333 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1334 val
->location
= arg
->location
;
1335 val
->offset
= arg
->offset
;
1336 val
->bitpos
= arg
->bitpos
;
1337 val
->bitsize
= arg
->bitsize
;
1338 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1339 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1340 val
->lazy
= arg
->lazy
;
1341 val
->optimized_out
= arg
->optimized_out
;
1342 val
->embedded_offset
= value_embedded_offset (arg
);
1343 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1344 val
->modifiable
= arg
->modifiable
;
1345 if (!value_lazy (val
))
1347 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1348 TYPE_LENGTH (value_enclosing_type (arg
)));
1351 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1352 val
->parent
= arg
->parent
;
1354 value_incref (val
->parent
);
1355 if (VALUE_LVAL (val
) == lval_computed
)
1357 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1359 if (funcs
->copy_closure
)
1360 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1365 /* Return a version of ARG that is non-lvalue. */
1368 value_non_lval (struct value
*arg
)
1370 if (VALUE_LVAL (arg
) != not_lval
)
1372 struct type
*enc_type
= value_enclosing_type (arg
);
1373 struct value
*val
= allocate_value (enc_type
);
1375 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1376 TYPE_LENGTH (enc_type
));
1377 val
->type
= arg
->type
;
1378 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1379 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1386 set_value_component_location (struct value
*component
,
1387 const struct value
*whole
)
1389 if (whole
->lval
== lval_internalvar
)
1390 VALUE_LVAL (component
) = lval_internalvar_component
;
1392 VALUE_LVAL (component
) = whole
->lval
;
1394 component
->location
= whole
->location
;
1395 if (whole
->lval
== lval_computed
)
1397 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1399 if (funcs
->copy_closure
)
1400 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1405 /* Access to the value history. */
1407 /* Record a new value in the value history.
1408 Returns the absolute history index of the entry.
1409 Result of -1 indicates the value was not saved; otherwise it is the
1410 value history index of this new item. */
1413 record_latest_value (struct value
*val
)
1417 /* We don't want this value to have anything to do with the inferior anymore.
1418 In particular, "set $1 = 50" should not affect the variable from which
1419 the value was taken, and fast watchpoints should be able to assume that
1420 a value on the value history never changes. */
1421 if (value_lazy (val
))
1422 value_fetch_lazy (val
);
1423 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1424 from. This is a bit dubious, because then *&$1 does not just return $1
1425 but the current contents of that location. c'est la vie... */
1426 val
->modifiable
= 0;
1427 release_value (val
);
1429 /* Here we treat value_history_count as origin-zero
1430 and applying to the value being stored now. */
1432 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1435 struct value_history_chunk
*new
1436 = (struct value_history_chunk
*)
1438 xmalloc (sizeof (struct value_history_chunk
));
1439 memset (new->values
, 0, sizeof new->values
);
1440 new->next
= value_history_chain
;
1441 value_history_chain
= new;
1444 value_history_chain
->values
[i
] = val
;
1446 /* Now we regard value_history_count as origin-one
1447 and applying to the value just stored. */
1449 return ++value_history_count
;
1452 /* Return a copy of the value in the history with sequence number NUM. */
1455 access_value_history (int num
)
1457 struct value_history_chunk
*chunk
;
1462 absnum
+= value_history_count
;
1467 error (_("The history is empty."));
1469 error (_("There is only one value in the history."));
1471 error (_("History does not go back to $$%d."), -num
);
1473 if (absnum
> value_history_count
)
1474 error (_("History has not yet reached $%d."), absnum
);
1478 /* Now absnum is always absolute and origin zero. */
1480 chunk
= value_history_chain
;
1481 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1482 - absnum
/ VALUE_HISTORY_CHUNK
;
1484 chunk
= chunk
->next
;
1486 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1490 show_values (char *num_exp
, int from_tty
)
1498 /* "show values +" should print from the stored position.
1499 "show values <exp>" should print around value number <exp>. */
1500 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1501 num
= parse_and_eval_long (num_exp
) - 5;
1505 /* "show values" means print the last 10 values. */
1506 num
= value_history_count
- 9;
1512 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1514 struct value_print_options opts
;
1516 val
= access_value_history (i
);
1517 printf_filtered (("$%d = "), i
);
1518 get_user_print_options (&opts
);
1519 value_print (val
, gdb_stdout
, &opts
);
1520 printf_filtered (("\n"));
1523 /* The next "show values +" should start after what we just printed. */
1526 /* Hitting just return after this command should do the same thing as
1527 "show values +". If num_exp is null, this is unnecessary, since
1528 "show values +" is not useful after "show values". */
1529 if (from_tty
&& num_exp
)
1536 /* Internal variables. These are variables within the debugger
1537 that hold values assigned by debugger commands.
1538 The user refers to them with a '$' prefix
1539 that does not appear in the variable names stored internally. */
1543 struct internalvar
*next
;
1546 /* We support various different kinds of content of an internal variable.
1547 enum internalvar_kind specifies the kind, and union internalvar_data
1548 provides the data associated with this particular kind. */
1550 enum internalvar_kind
1552 /* The internal variable is empty. */
1555 /* The value of the internal variable is provided directly as
1556 a GDB value object. */
1559 /* A fresh value is computed via a call-back routine on every
1560 access to the internal variable. */
1561 INTERNALVAR_MAKE_VALUE
,
1563 /* The internal variable holds a GDB internal convenience function. */
1564 INTERNALVAR_FUNCTION
,
1566 /* The variable holds an integer value. */
1567 INTERNALVAR_INTEGER
,
1569 /* The variable holds a GDB-provided string. */
1574 union internalvar_data
1576 /* A value object used with INTERNALVAR_VALUE. */
1577 struct value
*value
;
1579 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1580 internalvar_make_value make_value
;
1582 /* The internal function used with INTERNALVAR_FUNCTION. */
1585 struct internal_function
*function
;
1586 /* True if this is the canonical name for the function. */
1590 /* An integer value used with INTERNALVAR_INTEGER. */
1593 /* If type is non-NULL, it will be used as the type to generate
1594 a value for this internal variable. If type is NULL, a default
1595 integer type for the architecture is used. */
1600 /* A string value used with INTERNALVAR_STRING. */
1605 static struct internalvar
*internalvars
;
1607 /* If the variable does not already exist create it and give it the
1608 value given. If no value is given then the default is zero. */
1610 init_if_undefined_command (char* args
, int from_tty
)
1612 struct internalvar
* intvar
;
1614 /* Parse the expression - this is taken from set_command(). */
1615 struct expression
*expr
= parse_expression (args
);
1616 register struct cleanup
*old_chain
=
1617 make_cleanup (free_current_contents
, &expr
);
1619 /* Validate the expression.
1620 Was the expression an assignment?
1621 Or even an expression at all? */
1622 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1623 error (_("Init-if-undefined requires an assignment expression."));
1625 /* Extract the variable from the parsed expression.
1626 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1627 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1628 error (_("The first parameter to init-if-undefined "
1629 "should be a GDB variable."));
1630 intvar
= expr
->elts
[2].internalvar
;
1632 /* Only evaluate the expression if the lvalue is void.
1633 This may still fail if the expresssion is invalid. */
1634 if (intvar
->kind
== INTERNALVAR_VOID
)
1635 evaluate_expression (expr
);
1637 do_cleanups (old_chain
);
1641 /* Look up an internal variable with name NAME. NAME should not
1642 normally include a dollar sign.
1644 If the specified internal variable does not exist,
1645 the return value is NULL. */
1647 struct internalvar
*
1648 lookup_only_internalvar (const char *name
)
1650 struct internalvar
*var
;
1652 for (var
= internalvars
; var
; var
= var
->next
)
1653 if (strcmp (var
->name
, name
) == 0)
1660 /* Create an internal variable with name NAME and with a void value.
1661 NAME should not normally include a dollar sign. */
1663 struct internalvar
*
1664 create_internalvar (const char *name
)
1666 struct internalvar
*var
;
1668 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1669 var
->name
= concat (name
, (char *)NULL
);
1670 var
->kind
= INTERNALVAR_VOID
;
1671 var
->next
= internalvars
;
1676 /* Create an internal variable with name NAME and register FUN as the
1677 function that value_of_internalvar uses to create a value whenever
1678 this variable is referenced. NAME should not normally include a
1681 struct internalvar
*
1682 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1684 struct internalvar
*var
= create_internalvar (name
);
1686 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1687 var
->u
.make_value
= fun
;
1691 /* Look up an internal variable with name NAME. NAME should not
1692 normally include a dollar sign.
1694 If the specified internal variable does not exist,
1695 one is created, with a void value. */
1697 struct internalvar
*
1698 lookup_internalvar (const char *name
)
1700 struct internalvar
*var
;
1702 var
= lookup_only_internalvar (name
);
1706 return create_internalvar (name
);
1709 /* Return current value of internal variable VAR. For variables that
1710 are not inherently typed, use a value type appropriate for GDBARCH. */
1713 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1716 struct trace_state_variable
*tsv
;
1718 /* If there is a trace state variable of the same name, assume that
1719 is what we really want to see. */
1720 tsv
= find_trace_state_variable (var
->name
);
1723 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1725 if (tsv
->value_known
)
1726 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1729 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1735 case INTERNALVAR_VOID
:
1736 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1739 case INTERNALVAR_FUNCTION
:
1740 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1743 case INTERNALVAR_INTEGER
:
1744 if (!var
->u
.integer
.type
)
1745 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1746 var
->u
.integer
.val
);
1748 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1751 case INTERNALVAR_STRING
:
1752 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1753 builtin_type (gdbarch
)->builtin_char
);
1756 case INTERNALVAR_VALUE
:
1757 val
= value_copy (var
->u
.value
);
1758 if (value_lazy (val
))
1759 value_fetch_lazy (val
);
1762 case INTERNALVAR_MAKE_VALUE
:
1763 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1767 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1770 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1771 on this value go back to affect the original internal variable.
1773 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1774 no underlying modifyable state in the internal variable.
1776 Likewise, if the variable's value is a computed lvalue, we want
1777 references to it to produce another computed lvalue, where
1778 references and assignments actually operate through the
1779 computed value's functions.
1781 This means that internal variables with computed values
1782 behave a little differently from other internal variables:
1783 assignments to them don't just replace the previous value
1784 altogether. At the moment, this seems like the behavior we
1787 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1788 && val
->lval
!= lval_computed
)
1790 VALUE_LVAL (val
) = lval_internalvar
;
1791 VALUE_INTERNALVAR (val
) = var
;
1798 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1800 if (var
->kind
== INTERNALVAR_INTEGER
)
1802 *result
= var
->u
.integer
.val
;
1806 if (var
->kind
== INTERNALVAR_VALUE
)
1808 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1810 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1812 *result
= value_as_long (var
->u
.value
);
1821 get_internalvar_function (struct internalvar
*var
,
1822 struct internal_function
**result
)
1826 case INTERNALVAR_FUNCTION
:
1827 *result
= var
->u
.fn
.function
;
1836 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1837 int bitsize
, struct value
*newval
)
1843 case INTERNALVAR_VALUE
:
1844 addr
= value_contents_writeable (var
->u
.value
);
1847 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1848 value_as_long (newval
), bitpos
, bitsize
);
1850 memcpy (addr
+ offset
, value_contents (newval
),
1851 TYPE_LENGTH (value_type (newval
)));
1855 /* We can never get a component of any other kind. */
1856 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1861 set_internalvar (struct internalvar
*var
, struct value
*val
)
1863 enum internalvar_kind new_kind
;
1864 union internalvar_data new_data
= { 0 };
1866 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1867 error (_("Cannot overwrite convenience function %s"), var
->name
);
1869 /* Prepare new contents. */
1870 switch (TYPE_CODE (check_typedef (value_type (val
))))
1872 case TYPE_CODE_VOID
:
1873 new_kind
= INTERNALVAR_VOID
;
1876 case TYPE_CODE_INTERNAL_FUNCTION
:
1877 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1878 new_kind
= INTERNALVAR_FUNCTION
;
1879 get_internalvar_function (VALUE_INTERNALVAR (val
),
1880 &new_data
.fn
.function
);
1881 /* Copies created here are never canonical. */
1885 new_kind
= INTERNALVAR_VALUE
;
1886 new_data
.value
= value_copy (val
);
1887 new_data
.value
->modifiable
= 1;
1889 /* Force the value to be fetched from the target now, to avoid problems
1890 later when this internalvar is referenced and the target is gone or
1892 if (value_lazy (new_data
.value
))
1893 value_fetch_lazy (new_data
.value
);
1895 /* Release the value from the value chain to prevent it from being
1896 deleted by free_all_values. From here on this function should not
1897 call error () until new_data is installed into the var->u to avoid
1899 release_value (new_data
.value
);
1903 /* Clean up old contents. */
1904 clear_internalvar (var
);
1907 var
->kind
= new_kind
;
1909 /* End code which must not call error(). */
1913 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1915 /* Clean up old contents. */
1916 clear_internalvar (var
);
1918 var
->kind
= INTERNALVAR_INTEGER
;
1919 var
->u
.integer
.type
= NULL
;
1920 var
->u
.integer
.val
= l
;
1924 set_internalvar_string (struct internalvar
*var
, const char *string
)
1926 /* Clean up old contents. */
1927 clear_internalvar (var
);
1929 var
->kind
= INTERNALVAR_STRING
;
1930 var
->u
.string
= xstrdup (string
);
1934 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1936 /* Clean up old contents. */
1937 clear_internalvar (var
);
1939 var
->kind
= INTERNALVAR_FUNCTION
;
1940 var
->u
.fn
.function
= f
;
1941 var
->u
.fn
.canonical
= 1;
1942 /* Variables installed here are always the canonical version. */
1946 clear_internalvar (struct internalvar
*var
)
1948 /* Clean up old contents. */
1951 case INTERNALVAR_VALUE
:
1952 value_free (var
->u
.value
);
1955 case INTERNALVAR_STRING
:
1956 xfree (var
->u
.string
);
1963 /* Reset to void kind. */
1964 var
->kind
= INTERNALVAR_VOID
;
1968 internalvar_name (struct internalvar
*var
)
1973 static struct internal_function
*
1974 create_internal_function (const char *name
,
1975 internal_function_fn handler
, void *cookie
)
1977 struct internal_function
*ifn
= XNEW (struct internal_function
);
1979 ifn
->name
= xstrdup (name
);
1980 ifn
->handler
= handler
;
1981 ifn
->cookie
= cookie
;
1986 value_internal_function_name (struct value
*val
)
1988 struct internal_function
*ifn
;
1991 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1992 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
1993 gdb_assert (result
);
1999 call_internal_function (struct gdbarch
*gdbarch
,
2000 const struct language_defn
*language
,
2001 struct value
*func
, int argc
, struct value
**argv
)
2003 struct internal_function
*ifn
;
2006 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2007 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2008 gdb_assert (result
);
2010 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2013 /* The 'function' command. This does nothing -- it is just a
2014 placeholder to let "help function NAME" work. This is also used as
2015 the implementation of the sub-command that is created when
2016 registering an internal function. */
2018 function_command (char *command
, int from_tty
)
2023 /* Clean up if an internal function's command is destroyed. */
2025 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2031 /* Add a new internal function. NAME is the name of the function; DOC
2032 is a documentation string describing the function. HANDLER is
2033 called when the function is invoked. COOKIE is an arbitrary
2034 pointer which is passed to HANDLER and is intended for "user
2037 add_internal_function (const char *name
, const char *doc
,
2038 internal_function_fn handler
, void *cookie
)
2040 struct cmd_list_element
*cmd
;
2041 struct internal_function
*ifn
;
2042 struct internalvar
*var
= lookup_internalvar (name
);
2044 ifn
= create_internal_function (name
, handler
, cookie
);
2045 set_internalvar_function (var
, ifn
);
2047 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2049 cmd
->destroyer
= function_destroyer
;
2052 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2053 prevent cycles / duplicates. */
2056 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2057 htab_t copied_types
)
2059 if (TYPE_OBJFILE (value
->type
) == objfile
)
2060 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2062 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2063 value
->enclosing_type
= copy_type_recursive (objfile
,
2064 value
->enclosing_type
,
2068 /* Likewise for internal variable VAR. */
2071 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2072 htab_t copied_types
)
2076 case INTERNALVAR_INTEGER
:
2077 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2079 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2082 case INTERNALVAR_VALUE
:
2083 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2088 /* Update the internal variables and value history when OBJFILE is
2089 discarded; we must copy the types out of the objfile. New global types
2090 will be created for every convenience variable which currently points to
2091 this objfile's types, and the convenience variables will be adjusted to
2092 use the new global types. */
2095 preserve_values (struct objfile
*objfile
)
2097 htab_t copied_types
;
2098 struct value_history_chunk
*cur
;
2099 struct internalvar
*var
;
2102 /* Create the hash table. We allocate on the objfile's obstack, since
2103 it is soon to be deleted. */
2104 copied_types
= create_copied_types_hash (objfile
);
2106 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2107 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2109 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2111 for (var
= internalvars
; var
; var
= var
->next
)
2112 preserve_one_internalvar (var
, objfile
, copied_types
);
2114 preserve_python_values (objfile
, copied_types
);
2116 htab_delete (copied_types
);
2120 show_convenience (char *ignore
, int from_tty
)
2122 struct gdbarch
*gdbarch
= get_current_arch ();
2123 struct internalvar
*var
;
2125 struct value_print_options opts
;
2127 get_user_print_options (&opts
);
2128 for (var
= internalvars
; var
; var
= var
->next
)
2130 volatile struct gdb_exception ex
;
2136 printf_filtered (("$%s = "), var
->name
);
2138 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2142 val
= value_of_internalvar (gdbarch
, var
);
2143 value_print (val
, gdb_stdout
, &opts
);
2146 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2147 printf_filtered (("\n"));
2150 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2151 "Convenience variables have "
2152 "names starting with \"$\";\n"
2153 "use \"set\" as in \"set "
2154 "$foo = 5\" to define them.\n"));
2157 /* Extract a value as a C number (either long or double).
2158 Knows how to convert fixed values to double, or
2159 floating values to long.
2160 Does not deallocate the value. */
2163 value_as_long (struct value
*val
)
2165 /* This coerces arrays and functions, which is necessary (e.g.
2166 in disassemble_command). It also dereferences references, which
2167 I suspect is the most logical thing to do. */
2168 val
= coerce_array (val
);
2169 return unpack_long (value_type (val
), value_contents (val
));
2173 value_as_double (struct value
*val
)
2178 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2180 error (_("Invalid floating value found in program."));
2184 /* Extract a value as a C pointer. Does not deallocate the value.
2185 Note that val's type may not actually be a pointer; value_as_long
2186 handles all the cases. */
2188 value_as_address (struct value
*val
)
2190 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2192 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2193 whether we want this to be true eventually. */
2195 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2196 non-address (e.g. argument to "signal", "info break", etc.), or
2197 for pointers to char, in which the low bits *are* significant. */
2198 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2201 /* There are several targets (IA-64, PowerPC, and others) which
2202 don't represent pointers to functions as simply the address of
2203 the function's entry point. For example, on the IA-64, a
2204 function pointer points to a two-word descriptor, generated by
2205 the linker, which contains the function's entry point, and the
2206 value the IA-64 "global pointer" register should have --- to
2207 support position-independent code. The linker generates
2208 descriptors only for those functions whose addresses are taken.
2210 On such targets, it's difficult for GDB to convert an arbitrary
2211 function address into a function pointer; it has to either find
2212 an existing descriptor for that function, or call malloc and
2213 build its own. On some targets, it is impossible for GDB to
2214 build a descriptor at all: the descriptor must contain a jump
2215 instruction; data memory cannot be executed; and code memory
2218 Upon entry to this function, if VAL is a value of type `function'
2219 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2220 value_address (val) is the address of the function. This is what
2221 you'll get if you evaluate an expression like `main'. The call
2222 to COERCE_ARRAY below actually does all the usual unary
2223 conversions, which includes converting values of type `function'
2224 to `pointer to function'. This is the challenging conversion
2225 discussed above. Then, `unpack_long' will convert that pointer
2226 back into an address.
2228 So, suppose the user types `disassemble foo' on an architecture
2229 with a strange function pointer representation, on which GDB
2230 cannot build its own descriptors, and suppose further that `foo'
2231 has no linker-built descriptor. The address->pointer conversion
2232 will signal an error and prevent the command from running, even
2233 though the next step would have been to convert the pointer
2234 directly back into the same address.
2236 The following shortcut avoids this whole mess. If VAL is a
2237 function, just return its address directly. */
2238 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2239 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2240 return value_address (val
);
2242 val
= coerce_array (val
);
2244 /* Some architectures (e.g. Harvard), map instruction and data
2245 addresses onto a single large unified address space. For
2246 instance: An architecture may consider a large integer in the
2247 range 0x10000000 .. 0x1000ffff to already represent a data
2248 addresses (hence not need a pointer to address conversion) while
2249 a small integer would still need to be converted integer to
2250 pointer to address. Just assume such architectures handle all
2251 integer conversions in a single function. */
2255 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2256 must admonish GDB hackers to make sure its behavior matches the
2257 compiler's, whenever possible.
2259 In general, I think GDB should evaluate expressions the same way
2260 the compiler does. When the user copies an expression out of
2261 their source code and hands it to a `print' command, they should
2262 get the same value the compiler would have computed. Any
2263 deviation from this rule can cause major confusion and annoyance,
2264 and needs to be justified carefully. In other words, GDB doesn't
2265 really have the freedom to do these conversions in clever and
2268 AndrewC pointed out that users aren't complaining about how GDB
2269 casts integers to pointers; they are complaining that they can't
2270 take an address from a disassembly listing and give it to `x/i'.
2271 This is certainly important.
2273 Adding an architecture method like integer_to_address() certainly
2274 makes it possible for GDB to "get it right" in all circumstances
2275 --- the target has complete control over how things get done, so
2276 people can Do The Right Thing for their target without breaking
2277 anyone else. The standard doesn't specify how integers get
2278 converted to pointers; usually, the ABI doesn't either, but
2279 ABI-specific code is a more reasonable place to handle it. */
2281 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2282 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2283 && gdbarch_integer_to_address_p (gdbarch
))
2284 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2285 value_contents (val
));
2287 return unpack_long (value_type (val
), value_contents (val
));
2291 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2292 as a long, or as a double, assuming the raw data is described
2293 by type TYPE. Knows how to convert different sizes of values
2294 and can convert between fixed and floating point. We don't assume
2295 any alignment for the raw data. Return value is in host byte order.
2297 If you want functions and arrays to be coerced to pointers, and
2298 references to be dereferenced, call value_as_long() instead.
2300 C++: It is assumed that the front-end has taken care of
2301 all matters concerning pointers to members. A pointer
2302 to member which reaches here is considered to be equivalent
2303 to an INT (or some size). After all, it is only an offset. */
2306 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2308 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2309 enum type_code code
= TYPE_CODE (type
);
2310 int len
= TYPE_LENGTH (type
);
2311 int nosign
= TYPE_UNSIGNED (type
);
2315 case TYPE_CODE_TYPEDEF
:
2316 return unpack_long (check_typedef (type
), valaddr
);
2317 case TYPE_CODE_ENUM
:
2318 case TYPE_CODE_FLAGS
:
2319 case TYPE_CODE_BOOL
:
2321 case TYPE_CODE_CHAR
:
2322 case TYPE_CODE_RANGE
:
2323 case TYPE_CODE_MEMBERPTR
:
2325 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2327 return extract_signed_integer (valaddr
, len
, byte_order
);
2330 return extract_typed_floating (valaddr
, type
);
2332 case TYPE_CODE_DECFLOAT
:
2333 /* libdecnumber has a function to convert from decimal to integer, but
2334 it doesn't work when the decimal number has a fractional part. */
2335 return decimal_to_doublest (valaddr
, len
, byte_order
);
2339 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2340 whether we want this to be true eventually. */
2341 return extract_typed_address (valaddr
, type
);
2344 error (_("Value can't be converted to integer."));
2346 return 0; /* Placate lint. */
2349 /* Return a double value from the specified type and address.
2350 INVP points to an int which is set to 0 for valid value,
2351 1 for invalid value (bad float format). In either case,
2352 the returned double is OK to use. Argument is in target
2353 format, result is in host format. */
2356 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2358 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2359 enum type_code code
;
2363 *invp
= 0; /* Assume valid. */
2364 CHECK_TYPEDEF (type
);
2365 code
= TYPE_CODE (type
);
2366 len
= TYPE_LENGTH (type
);
2367 nosign
= TYPE_UNSIGNED (type
);
2368 if (code
== TYPE_CODE_FLT
)
2370 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2371 floating-point value was valid (using the macro
2372 INVALID_FLOAT). That test/macro have been removed.
2374 It turns out that only the VAX defined this macro and then
2375 only in a non-portable way. Fixing the portability problem
2376 wouldn't help since the VAX floating-point code is also badly
2377 bit-rotten. The target needs to add definitions for the
2378 methods gdbarch_float_format and gdbarch_double_format - these
2379 exactly describe the target floating-point format. The
2380 problem here is that the corresponding floatformat_vax_f and
2381 floatformat_vax_d values these methods should be set to are
2382 also not defined either. Oops!
2384 Hopefully someone will add both the missing floatformat
2385 definitions and the new cases for floatformat_is_valid (). */
2387 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2393 return extract_typed_floating (valaddr
, type
);
2395 else if (code
== TYPE_CODE_DECFLOAT
)
2396 return decimal_to_doublest (valaddr
, len
, byte_order
);
2399 /* Unsigned -- be sure we compensate for signed LONGEST. */
2400 return (ULONGEST
) unpack_long (type
, valaddr
);
2404 /* Signed -- we are OK with unpack_long. */
2405 return unpack_long (type
, valaddr
);
2409 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2410 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2411 We don't assume any alignment for the raw data. Return value is in
2414 If you want functions and arrays to be coerced to pointers, and
2415 references to be dereferenced, call value_as_address() instead.
2417 C++: It is assumed that the front-end has taken care of
2418 all matters concerning pointers to members. A pointer
2419 to member which reaches here is considered to be equivalent
2420 to an INT (or some size). After all, it is only an offset. */
2423 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
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 unpack_long (type
, valaddr
);
2431 /* Get the value of the FIELDNO'th field (which must be static) of
2432 TYPE. Return NULL if the field doesn't exist or has been
2436 value_static_field (struct type
*type
, int fieldno
)
2438 struct value
*retval
;
2440 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2442 case FIELD_LOC_KIND_PHYSADDR
:
2443 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2444 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2446 case FIELD_LOC_KIND_PHYSNAME
:
2448 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2449 /* TYPE_FIELD_NAME (type, fieldno); */
2450 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2454 /* With some compilers, e.g. HP aCC, static data members are
2455 reported as non-debuggable symbols. */
2456 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2463 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2464 SYMBOL_VALUE_ADDRESS (msym
));
2468 retval
= value_of_variable (sym
, NULL
);
2472 gdb_assert_not_reached ("unexpected field location kind");
2478 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2479 You have to be careful here, since the size of the data area for the value
2480 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2481 than the old enclosing type, you have to allocate more space for the
2485 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2487 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2489 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2491 val
->enclosing_type
= new_encl_type
;
2494 /* Given a value ARG1 (offset by OFFSET bytes)
2495 of a struct or union type ARG_TYPE,
2496 extract and return the value of one of its (non-static) fields.
2497 FIELDNO says which field. */
2500 value_primitive_field (struct value
*arg1
, int offset
,
2501 int fieldno
, struct type
*arg_type
)
2506 CHECK_TYPEDEF (arg_type
);
2507 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2509 /* Call check_typedef on our type to make sure that, if TYPE
2510 is a TYPE_CODE_TYPEDEF, its length is set to the length
2511 of the target type instead of zero. However, we do not
2512 replace the typedef type by the target type, because we want
2513 to keep the typedef in order to be able to print the type
2514 description correctly. */
2515 check_typedef (type
);
2517 if (value_optimized_out (arg1
))
2518 v
= allocate_optimized_out_value (type
);
2519 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2521 /* Handle packed fields.
2523 Create a new value for the bitfield, with bitpos and bitsize
2524 set. If possible, arrange offset and bitpos so that we can
2525 do a single aligned read of the size of the containing type.
2526 Otherwise, adjust offset to the byte containing the first
2527 bit. Assume that the address, offset, and embedded offset
2528 are sufficiently aligned. */
2530 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2531 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2533 v
= allocate_value_lazy (type
);
2534 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2535 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2536 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2537 v
->bitpos
= bitpos
% container_bitsize
;
2539 v
->bitpos
= bitpos
% 8;
2540 v
->offset
= (value_embedded_offset (arg1
)
2542 + (bitpos
- v
->bitpos
) / 8);
2544 value_incref (v
->parent
);
2545 if (!value_lazy (arg1
))
2546 value_fetch_lazy (v
);
2548 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2550 /* This field is actually a base subobject, so preserve the
2551 entire object's contents for later references to virtual
2555 /* Lazy register values with offsets are not supported. */
2556 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2557 value_fetch_lazy (arg1
);
2559 boffset
= baseclass_offset (arg_type
, fieldno
,
2560 value_contents (arg1
),
2561 value_embedded_offset (arg1
),
2562 value_address (arg1
),
2565 if (value_lazy (arg1
))
2566 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2569 v
= allocate_value (value_enclosing_type (arg1
));
2570 value_contents_copy_raw (v
, 0, arg1
, 0,
2571 TYPE_LENGTH (value_enclosing_type (arg1
)));
2574 v
->offset
= value_offset (arg1
);
2575 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2579 /* Plain old data member */
2580 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2582 /* Lazy register values with offsets are not supported. */
2583 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2584 value_fetch_lazy (arg1
);
2586 if (value_lazy (arg1
))
2587 v
= allocate_value_lazy (type
);
2590 v
= allocate_value (type
);
2591 value_contents_copy_raw (v
, value_embedded_offset (v
),
2592 arg1
, value_embedded_offset (arg1
) + offset
,
2593 TYPE_LENGTH (type
));
2595 v
->offset
= (value_offset (arg1
) + offset
2596 + value_embedded_offset (arg1
));
2598 set_value_component_location (v
, arg1
);
2599 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2600 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2604 /* Given a value ARG1 of a struct or union type,
2605 extract and return the value of one of its (non-static) fields.
2606 FIELDNO says which field. */
2609 value_field (struct value
*arg1
, int fieldno
)
2611 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2614 /* Return a non-virtual function as a value.
2615 F is the list of member functions which contains the desired method.
2616 J is an index into F which provides the desired method.
2618 We only use the symbol for its address, so be happy with either a
2619 full symbol or a minimal symbol. */
2622 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2623 int j
, struct type
*type
,
2627 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2628 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2630 struct minimal_symbol
*msym
;
2632 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2639 gdb_assert (sym
== NULL
);
2640 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2645 v
= allocate_value (ftype
);
2648 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2652 /* The minimal symbol might point to a function descriptor;
2653 resolve it to the actual code address instead. */
2654 struct objfile
*objfile
= msymbol_objfile (msym
);
2655 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2657 set_value_address (v
,
2658 gdbarch_convert_from_func_ptr_addr
2659 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2664 if (type
!= value_type (*arg1p
))
2665 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2666 value_addr (*arg1p
)));
2668 /* Move the `this' pointer according to the offset.
2669 VALUE_OFFSET (*arg1p) += offset; */
2677 /* Helper function for both unpack_value_bits_as_long and
2678 unpack_bits_as_long. See those functions for more details on the
2679 interface; the only difference is that this function accepts either
2680 a NULL or a non-NULL ORIGINAL_VALUE. */
2683 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2684 int embedded_offset
, int bitpos
, int bitsize
,
2685 const struct value
*original_value
,
2688 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2695 /* Read the minimum number of bytes required; there may not be
2696 enough bytes to read an entire ULONGEST. */
2697 CHECK_TYPEDEF (field_type
);
2699 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2701 bytes_read
= TYPE_LENGTH (field_type
);
2703 read_offset
= bitpos
/ 8;
2705 if (original_value
!= NULL
2706 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2710 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2711 bytes_read
, byte_order
);
2713 /* Extract bits. See comment above. */
2715 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2716 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2718 lsbcount
= (bitpos
% 8);
2721 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2722 If the field is signed, and is negative, then sign extend. */
2724 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2726 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2728 if (!TYPE_UNSIGNED (field_type
))
2730 if (val
& (valmask
^ (valmask
>> 1)))
2741 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2742 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2743 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2744 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2747 Returns false if the value contents are unavailable, otherwise
2748 returns true, indicating a valid value has been stored in *RESULT.
2750 Extracting bits depends on endianness of the machine. Compute the
2751 number of least significant bits to discard. For big endian machines,
2752 we compute the total number of bits in the anonymous object, subtract
2753 off the bit count from the MSB of the object to the MSB of the
2754 bitfield, then the size of the bitfield, which leaves the LSB discard
2755 count. For little endian machines, the discard count is simply the
2756 number of bits from the LSB of the anonymous object to the LSB of the
2759 If the field is signed, we also do sign extension. */
2762 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2763 int embedded_offset
, int bitpos
, int bitsize
,
2764 const struct value
*original_value
,
2767 gdb_assert (original_value
!= NULL
);
2769 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2770 bitpos
, bitsize
, original_value
, result
);
2774 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2775 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2776 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2780 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2781 int embedded_offset
, int fieldno
,
2782 const struct value
*val
, LONGEST
*result
)
2784 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2785 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2786 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2788 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2789 bitpos
, bitsize
, val
,
2793 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2794 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2795 ORIGINAL_VALUE, which must not be NULL. See
2796 unpack_value_bits_as_long for more details. */
2799 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2800 int embedded_offset
, int fieldno
,
2801 const struct value
*val
, LONGEST
*result
)
2803 gdb_assert (val
!= NULL
);
2805 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2806 fieldno
, val
, result
);
2809 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2810 object at VALADDR. See unpack_value_bits_as_long for more details.
2811 This function differs from unpack_value_field_as_long in that it
2812 operates without a struct value object. */
2815 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2819 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2823 /* Return a new value with type TYPE, which is FIELDNO field of the
2824 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2825 of VAL. If the VAL's contents required to extract the bitfield
2826 from are unavailable, the new value is correspondingly marked as
2830 value_field_bitfield (struct type
*type
, int fieldno
,
2831 const gdb_byte
*valaddr
,
2832 int embedded_offset
, const struct value
*val
)
2836 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2839 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2840 struct value
*retval
= allocate_value (field_type
);
2841 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2846 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2850 /* Modify the value of a bitfield. ADDR points to a block of memory in
2851 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2852 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2853 indicate which bits (in target bit order) comprise the bitfield.
2854 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2855 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2858 modify_field (struct type
*type
, gdb_byte
*addr
,
2859 LONGEST fieldval
, int bitpos
, int bitsize
)
2861 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2863 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2866 /* Normalize BITPOS. */
2870 /* If a negative fieldval fits in the field in question, chop
2871 off the sign extension bits. */
2872 if ((~fieldval
& ~(mask
>> 1)) == 0)
2875 /* Warn if value is too big to fit in the field in question. */
2876 if (0 != (fieldval
& ~mask
))
2878 /* FIXME: would like to include fieldval in the message, but
2879 we don't have a sprintf_longest. */
2880 warning (_("Value does not fit in %d bits."), bitsize
);
2882 /* Truncate it, otherwise adjoining fields may be corrupted. */
2886 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2887 false valgrind reports. */
2889 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2890 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2892 /* Shifting for bit field depends on endianness of the target machine. */
2893 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2894 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2896 oword
&= ~(mask
<< bitpos
);
2897 oword
|= fieldval
<< bitpos
;
2899 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2902 /* Pack NUM into BUF using a target format of TYPE. */
2905 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2907 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2910 type
= check_typedef (type
);
2911 len
= TYPE_LENGTH (type
);
2913 switch (TYPE_CODE (type
))
2916 case TYPE_CODE_CHAR
:
2917 case TYPE_CODE_ENUM
:
2918 case TYPE_CODE_FLAGS
:
2919 case TYPE_CODE_BOOL
:
2920 case TYPE_CODE_RANGE
:
2921 case TYPE_CODE_MEMBERPTR
:
2922 store_signed_integer (buf
, len
, byte_order
, num
);
2927 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2931 error (_("Unexpected type (%d) encountered for integer constant."),
2937 /* Pack NUM into BUF using a target format of TYPE. */
2940 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2943 enum bfd_endian byte_order
;
2945 type
= check_typedef (type
);
2946 len
= TYPE_LENGTH (type
);
2947 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2949 switch (TYPE_CODE (type
))
2952 case TYPE_CODE_CHAR
:
2953 case TYPE_CODE_ENUM
:
2954 case TYPE_CODE_FLAGS
:
2955 case TYPE_CODE_BOOL
:
2956 case TYPE_CODE_RANGE
:
2957 case TYPE_CODE_MEMBERPTR
:
2958 store_unsigned_integer (buf
, len
, byte_order
, num
);
2963 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2967 error (_("Unexpected type (%d) encountered "
2968 "for unsigned integer constant."),
2974 /* Convert C numbers into newly allocated values. */
2977 value_from_longest (struct type
*type
, LONGEST num
)
2979 struct value
*val
= allocate_value (type
);
2981 pack_long (value_contents_raw (val
), type
, num
);
2986 /* Convert C unsigned numbers into newly allocated values. */
2989 value_from_ulongest (struct type
*type
, ULONGEST num
)
2991 struct value
*val
= allocate_value (type
);
2993 pack_unsigned_long (value_contents_raw (val
), type
, num
);
2999 /* Create a value representing a pointer of type TYPE to the address
3002 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3004 struct value
*val
= allocate_value (type
);
3006 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3011 /* Create a value of type TYPE whose contents come from VALADDR, if it
3012 is non-null, and whose memory address (in the inferior) is
3016 value_from_contents_and_address (struct type
*type
,
3017 const gdb_byte
*valaddr
,
3022 if (valaddr
== NULL
)
3023 v
= allocate_value_lazy (type
);
3026 v
= allocate_value (type
);
3027 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3029 set_value_address (v
, address
);
3030 VALUE_LVAL (v
) = lval_memory
;
3034 /* Create a value of type TYPE holding the contents CONTENTS.
3035 The new value is `not_lval'. */
3038 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3040 struct value
*result
;
3042 result
= allocate_value (type
);
3043 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3048 value_from_double (struct type
*type
, DOUBLEST num
)
3050 struct value
*val
= allocate_value (type
);
3051 struct type
*base_type
= check_typedef (type
);
3052 enum type_code code
= TYPE_CODE (base_type
);
3054 if (code
== TYPE_CODE_FLT
)
3056 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3059 error (_("Unexpected type encountered for floating constant."));
3065 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3067 struct value
*val
= allocate_value (type
);
3069 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3073 /* Extract a value from the history file. Input will be of the form
3074 $digits or $$digits. See block comment above 'write_dollar_variable'
3078 value_from_history_ref (char *h
, char **endp
)
3090 /* Find length of numeral string. */
3091 for (; isdigit (h
[len
]); len
++)
3094 /* Make sure numeral string is not part of an identifier. */
3095 if (h
[len
] == '_' || isalpha (h
[len
]))
3098 /* Now collect the index value. */
3103 /* For some bizarre reason, "$$" is equivalent to "$$1",
3104 rather than to "$$0" as it ought to be! */
3109 index
= -strtol (&h
[2], endp
, 10);
3115 /* "$" is equivalent to "$0". */
3120 index
= strtol (&h
[1], endp
, 10);
3123 return access_value_history (index
);
3127 coerce_ref_if_computed (const struct value
*arg
)
3129 const struct lval_funcs
*funcs
;
3131 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3134 if (value_lval_const (arg
) != lval_computed
)
3137 funcs
= value_computed_funcs (arg
);
3138 if (funcs
->coerce_ref
== NULL
)
3141 return funcs
->coerce_ref (arg
);
3144 /* Look at value.h for description. */
3147 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3148 struct type
*original_type
,
3149 struct value
*original_value
)
3151 /* Re-adjust type. */
3152 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3154 /* Add embedding info. */
3155 set_value_enclosing_type (value
, enc_type
);
3156 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3158 /* We may be pointing to an object of some derived type. */
3159 return value_full_object (value
, NULL
, 0, 0, 0);
3163 coerce_ref (struct value
*arg
)
3165 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3166 struct value
*retval
;
3167 struct type
*enc_type
;
3169 retval
= coerce_ref_if_computed (arg
);
3173 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3176 enc_type
= check_typedef (value_enclosing_type (arg
));
3177 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3179 retval
= value_at_lazy (enc_type
,
3180 unpack_pointer (value_type (arg
),
3181 value_contents (arg
)));
3182 return readjust_indirect_value_type (retval
, enc_type
,
3183 value_type_arg_tmp
, arg
);
3187 coerce_array (struct value
*arg
)
3191 arg
= coerce_ref (arg
);
3192 type
= check_typedef (value_type (arg
));
3194 switch (TYPE_CODE (type
))
3196 case TYPE_CODE_ARRAY
:
3197 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3198 arg
= value_coerce_array (arg
);
3200 case TYPE_CODE_FUNC
:
3201 arg
= value_coerce_function (arg
);
3208 /* Return true if the function returning the specified type is using
3209 the convention of returning structures in memory (passing in the
3210 address as a hidden first parameter). */
3213 using_struct_return (struct gdbarch
*gdbarch
,
3214 struct type
*func_type
, struct type
*value_type
)
3216 enum type_code code
= TYPE_CODE (value_type
);
3218 if (code
== TYPE_CODE_ERROR
)
3219 error (_("Function return type unknown."));
3221 if (code
== TYPE_CODE_VOID
)
3222 /* A void return value is never in memory. See also corresponding
3223 code in "print_return_value". */
3226 /* Probe the architecture for the return-value convention. */
3227 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
3229 != RETURN_VALUE_REGISTER_CONVENTION
);
3232 /* Set the initialized field in a value struct. */
3235 set_value_initialized (struct value
*val
, int status
)
3237 val
->initialized
= status
;
3240 /* Return the initialized field in a value struct. */
3243 value_initialized (struct value
*val
)
3245 return val
->initialized
;
3249 _initialize_values (void)
3251 add_cmd ("convenience", no_class
, show_convenience
, _("\
3252 Debugger convenience (\"$foo\") variables.\n\
3253 These variables are created when you assign them values;\n\
3254 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3256 A few convenience variables are given values automatically:\n\
3257 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3258 \"$__\" holds the contents of the last address examined with \"x\"."),
3261 add_cmd ("values", no_set_class
, show_values
, _("\
3262 Elements of value history around item number IDX (or last ten)."),
3265 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3266 Initialize a convenience variable if necessary.\n\
3267 init-if-undefined VARIABLE = EXPRESSION\n\
3268 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3269 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3270 VARIABLE is already initialized."));
3272 add_prefix_cmd ("function", no_class
, function_command
, _("\
3273 Placeholder command for showing help on convenience functions."),
3274 &functionlist
, "function ", 0, &cmdlist
);