1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2016 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"
37 #include "cli/cli-decode.h"
38 #include "extension.h"
40 #include "tracepoint.h"
42 #include "user-regs.h"
44 /* Prototypes for exported functions. */
46 void _initialize_values (void);
48 /* Definition of a user function. */
49 struct internal_function
51 /* The name of the function. It is a bit odd to have this in the
52 function itself -- the user might use a differently-named
53 convenience variable to hold the function. */
57 internal_function_fn handler
;
59 /* User data for the handler. */
63 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
67 /* Lowest offset in the range. */
70 /* Length of the range. */
74 typedef struct range range_s
;
78 /* Returns true if the ranges defined by [offset1, offset1+len1) and
79 [offset2, offset2+len2) overlap. */
82 ranges_overlap (LONGEST offset1
, LONGEST len1
,
83 LONGEST offset2
, LONGEST len2
)
87 l
= max (offset1
, offset2
);
88 h
= min (offset1
+ len1
, offset2
+ len2
);
92 /* Returns true if the first argument is strictly less than the
93 second, useful for VEC_lower_bound. We keep ranges sorted by
94 offset and coalesce overlapping and contiguous ranges, so this just
95 compares the starting offset. */
98 range_lessthan (const range_s
*r1
, const range_s
*r2
)
100 return r1
->offset
< r2
->offset
;
103 /* Returns true if RANGES contains any range that overlaps [OFFSET,
107 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
112 what
.offset
= offset
;
113 what
.length
= length
;
115 /* We keep ranges sorted by offset and coalesce overlapping and
116 contiguous ranges, so to check if a range list contains a given
117 range, we can do a binary search for the position the given range
118 would be inserted if we only considered the starting OFFSET of
119 ranges. We call that position I. Since we also have LENGTH to
120 care for (this is a range afterall), we need to check if the
121 _previous_ range overlaps the I range. E.g.,
125 |---| |---| |------| ... |--|
130 In the case above, the binary search would return `I=1', meaning,
131 this OFFSET should be inserted at position 1, and the current
132 position 1 should be pushed further (and before 2). But, `0'
135 Then we need to check if the I range overlaps the I range itself.
140 |---| |---| |-------| ... |--|
146 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
150 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
152 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
156 if (i
< VEC_length (range_s
, ranges
))
158 struct range
*r
= VEC_index (range_s
, ranges
, i
);
160 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
167 static struct cmd_list_element
*functionlist
;
169 /* Note that the fields in this structure are arranged to save a bit
174 /* Type of value; either not an lval, or one of the various
175 different possible kinds of lval. */
178 /* Is it modifiable? Only relevant if lval != not_lval. */
179 unsigned int modifiable
: 1;
181 /* If zero, contents of this value are in the contents field. If
182 nonzero, contents are in inferior. If the lval field is lval_memory,
183 the contents are in inferior memory at location.address plus offset.
184 The lval field may also be lval_register.
186 WARNING: This field is used by the code which handles watchpoints
187 (see breakpoint.c) to decide whether a particular value can be
188 watched by hardware watchpoints. If the lazy flag is set for
189 some member of a value chain, it is assumed that this member of
190 the chain doesn't need to be watched as part of watching the
191 value itself. This is how GDB avoids watching the entire struct
192 or array when the user wants to watch a single struct member or
193 array element. If you ever change the way lazy flag is set and
194 reset, be sure to consider this use as well! */
195 unsigned int lazy
: 1;
197 /* If value is a variable, is it initialized or not. */
198 unsigned int initialized
: 1;
200 /* If value is from the stack. If this is set, read_stack will be
201 used instead of read_memory to enable extra caching. */
202 unsigned int stack
: 1;
204 /* If the value has been released. */
205 unsigned int released
: 1;
207 /* Register number if the value is from a register. */
210 /* Location of value (if lval). */
213 /* If lval == lval_memory, this is the address in the inferior.
214 If lval == lval_register, this is the byte offset into the
215 registers structure. */
218 /* Pointer to internal variable. */
219 struct internalvar
*internalvar
;
221 /* Pointer to xmethod worker. */
222 struct xmethod_worker
*xm_worker
;
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 target
238 addressable memory units. If lval == lval_memory, this is an offset to
239 the address. If lval == lval_register, this is a further offset from
240 location.address within the registers structure. Note also the member
241 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 target addressable memory
295 units. The value_contents() macro takes `embedded_offset' into account,
296 so most GDB code continues to see the `type' portion of the value, just
297 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 target addressable memory units from the full object
302 to the pointed-to object -- that is, the value `embedded_offset' would
303 have if we followed the pointer and fetched the complete object.
304 (I don't really see the point. Why not just determine the
305 run-time type when you indirect, and avoid the special case? The
306 contents don't matter 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
;
312 LONGEST embedded_offset
;
313 LONGEST 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 /* Actual contents of the value. Target byte-order. NULL or not
322 valid if lazy is nonzero. */
325 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
326 rather than available, since the common and default case is for a
327 value to be available. This is filled in at value read time.
328 The unavailable ranges are tracked in bits. Note that a contents
329 bit that has been optimized out doesn't really exist in the
330 program, so it can't be marked unavailable either. */
331 VEC(range_s
) *unavailable
;
333 /* Likewise, but for optimized out contents (a chunk of the value of
334 a variable that does not actually exist in the program). If LVAL
335 is lval_register, this is a register ($pc, $sp, etc., never a
336 program variable) that has not been saved in the frame. Not
337 saved registers and optimized-out program variables values are
338 treated pretty much the same, except not-saved registers have a
339 different string representation and related error strings. */
340 VEC(range_s
) *optimized_out
;
346 get_value_arch (const struct value
*value
)
348 return get_type_arch (value_type (value
));
352 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
354 gdb_assert (!value
->lazy
);
356 return !ranges_contain (value
->unavailable
, offset
, length
);
360 value_bytes_available (const struct value
*value
,
361 LONGEST offset
, LONGEST length
)
363 return value_bits_available (value
,
364 offset
* TARGET_CHAR_BIT
,
365 length
* TARGET_CHAR_BIT
);
369 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
371 gdb_assert (!value
->lazy
);
373 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
377 value_entirely_available (struct value
*value
)
379 /* We can only tell whether the whole value is available when we try
382 value_fetch_lazy (value
);
384 if (VEC_empty (range_s
, value
->unavailable
))
389 /* Returns true if VALUE is entirely covered by RANGES. If the value
390 is lazy, it'll be read now. Note that RANGE is a pointer to
391 pointer because reading the value might change *RANGE. */
394 value_entirely_covered_by_range_vector (struct value
*value
,
395 VEC(range_s
) **ranges
)
397 /* We can only tell whether the whole value is optimized out /
398 unavailable when we try to read it. */
400 value_fetch_lazy (value
);
402 if (VEC_length (range_s
, *ranges
) == 1)
404 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
407 && t
->length
== (TARGET_CHAR_BIT
408 * TYPE_LENGTH (value_enclosing_type (value
))))
416 value_entirely_unavailable (struct value
*value
)
418 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
422 value_entirely_optimized_out (struct value
*value
)
424 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
427 /* Insert into the vector pointed to by VECTORP the bit range starting of
428 OFFSET bits, and extending for the next LENGTH bits. */
431 insert_into_bit_range_vector (VEC(range_s
) **vectorp
,
432 LONGEST offset
, LONGEST length
)
437 /* Insert the range sorted. If there's overlap or the new range
438 would be contiguous with an existing range, merge. */
440 newr
.offset
= offset
;
441 newr
.length
= length
;
443 /* Do a binary search for the position the given range would be
444 inserted if we only considered the starting OFFSET of ranges.
445 Call that position I. Since we also have LENGTH to care for
446 (this is a range afterall), we need to check if the _previous_
447 range overlaps the I range. E.g., calling R the new range:
449 #1 - overlaps with previous
453 |---| |---| |------| ... |--|
458 In the case #1 above, the binary search would return `I=1',
459 meaning, this OFFSET should be inserted at position 1, and the
460 current position 1 should be pushed further (and become 2). But,
461 note that `0' overlaps with R, so we want to merge them.
463 A similar consideration needs to be taken if the new range would
464 be contiguous with the previous range:
466 #2 - contiguous with previous
470 |--| |---| |------| ... |--|
475 If there's no overlap with the previous range, as in:
477 #3 - not overlapping and not contiguous
481 |--| |---| |------| ... |--|
488 #4 - R is the range with lowest offset
492 |--| |---| |------| ... |--|
497 ... we just push the new range to I.
499 All the 4 cases above need to consider that the new range may
500 also overlap several of the ranges that follow, or that R may be
501 contiguous with the following range, and merge. E.g.,
503 #5 - overlapping following ranges
506 |------------------------|
507 |--| |---| |------| ... |--|
516 |--| |---| |------| ... |--|
523 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
526 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
528 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
531 ULONGEST l
= min (bef
->offset
, offset
);
532 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
538 else if (offset
== bef
->offset
+ bef
->length
)
541 bef
->length
+= length
;
547 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
553 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
556 /* Check whether the ranges following the one we've just added or
557 touched can be folded in (#5 above). */
558 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
565 /* Get the range we just touched. */
566 t
= VEC_index (range_s
, *vectorp
, i
);
570 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
571 if (r
->offset
<= t
->offset
+ t
->length
)
575 l
= min (t
->offset
, r
->offset
);
576 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
585 /* If we couldn't merge this one, we won't be able to
586 merge following ones either, since the ranges are
587 always sorted by OFFSET. */
592 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
597 mark_value_bits_unavailable (struct value
*value
,
598 LONGEST offset
, LONGEST length
)
600 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
604 mark_value_bytes_unavailable (struct value
*value
,
605 LONGEST offset
, LONGEST length
)
607 mark_value_bits_unavailable (value
,
608 offset
* TARGET_CHAR_BIT
,
609 length
* TARGET_CHAR_BIT
);
612 /* Find the first range in RANGES that overlaps the range defined by
613 OFFSET and LENGTH, starting at element POS in the RANGES vector,
614 Returns the index into RANGES where such overlapping range was
615 found, or -1 if none was found. */
618 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
619 LONGEST offset
, LONGEST length
)
624 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
625 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
631 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
632 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
635 It must always be the case that:
636 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
638 It is assumed that memory can be accessed from:
639 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
641 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
642 / TARGET_CHAR_BIT) */
644 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
645 const gdb_byte
*ptr2
, size_t offset2_bits
,
648 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
649 == offset2_bits
% TARGET_CHAR_BIT
);
651 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
654 gdb_byte mask
, b1
, b2
;
656 /* The offset from the base pointers PTR1 and PTR2 is not a complete
657 number of bytes. A number of bits up to either the next exact
658 byte boundary, or LENGTH_BITS (which ever is sooner) will be
660 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
661 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
662 mask
= (1 << bits
) - 1;
664 if (length_bits
< bits
)
666 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
670 /* Now load the two bytes and mask off the bits we care about. */
671 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
672 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
677 /* Now update the length and offsets to take account of the bits
678 we've just compared. */
680 offset1_bits
+= bits
;
681 offset2_bits
+= bits
;
684 if (length_bits
% TARGET_CHAR_BIT
!= 0)
688 gdb_byte mask
, b1
, b2
;
690 /* The length is not an exact number of bytes. After the previous
691 IF.. block then the offsets are byte aligned, or the
692 length is zero (in which case this code is not reached). Compare
693 a number of bits at the end of the region, starting from an exact
695 bits
= length_bits
% TARGET_CHAR_BIT
;
696 o1
= offset1_bits
+ length_bits
- bits
;
697 o2
= offset2_bits
+ length_bits
- bits
;
699 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
700 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
702 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
703 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
705 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
706 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
716 /* We've now taken care of any stray "bits" at the start, or end of
717 the region to compare, the remainder can be covered with a simple
719 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
720 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
721 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
723 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
724 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
725 length_bits
/ TARGET_CHAR_BIT
);
728 /* Length is zero, regions match. */
732 /* Helper struct for find_first_range_overlap_and_match and
733 value_contents_bits_eq. Keep track of which slot of a given ranges
734 vector have we last looked at. */
736 struct ranges_and_idx
739 VEC(range_s
) *ranges
;
741 /* The range we've last found in RANGES. Given ranges are sorted,
742 we can start the next lookup here. */
746 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
747 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
748 ranges starting at OFFSET2 bits. Return true if the ranges match
749 and fill in *L and *H with the overlapping window relative to
750 (both) OFFSET1 or OFFSET2. */
753 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
754 struct ranges_and_idx
*rp2
,
755 LONGEST offset1
, LONGEST offset2
,
756 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
758 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
760 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
763 if (rp1
->idx
== -1 && rp2
->idx
== -1)
769 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
777 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
778 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
780 /* Get the unavailable windows intersected by the incoming
781 ranges. The first and last ranges that overlap the argument
782 range may be wider than said incoming arguments ranges. */
783 l1
= max (offset1
, r1
->offset
);
784 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
786 l2
= max (offset2
, r2
->offset
);
787 h2
= min (offset2
+ length
, offset2
+ r2
->length
);
789 /* Make them relative to the respective start offsets, so we can
790 compare them for equality. */
797 /* Different ranges, no match. */
798 if (l1
!= l2
|| h1
!= h2
)
807 /* Helper function for value_contents_eq. The only difference is that
808 this function is bit rather than byte based.
810 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
811 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
812 Return true if the available bits match. */
815 value_contents_bits_eq (const struct value
*val1
, int offset1
,
816 const struct value
*val2
, int offset2
,
819 /* Each array element corresponds to a ranges source (unavailable,
820 optimized out). '1' is for VAL1, '2' for VAL2. */
821 struct ranges_and_idx rp1
[2], rp2
[2];
823 /* See function description in value.h. */
824 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
826 /* We shouldn't be trying to compare past the end of the values. */
827 gdb_assert (offset1
+ length
828 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
829 gdb_assert (offset2
+ length
830 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
832 memset (&rp1
, 0, sizeof (rp1
));
833 memset (&rp2
, 0, sizeof (rp2
));
834 rp1
[0].ranges
= val1
->unavailable
;
835 rp2
[0].ranges
= val2
->unavailable
;
836 rp1
[1].ranges
= val1
->optimized_out
;
837 rp2
[1].ranges
= val2
->optimized_out
;
841 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
844 for (i
= 0; i
< 2; i
++)
846 ULONGEST l_tmp
, h_tmp
;
848 /* The contents only match equal if the invalid/unavailable
849 contents ranges match as well. */
850 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
851 offset1
, offset2
, length
,
855 /* We're interested in the lowest/first range found. */
856 if (i
== 0 || l_tmp
< l
)
863 /* Compare the available/valid contents. */
864 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
865 val2
->contents
, offset2
, l
) != 0)
877 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
878 const struct value
*val2
, LONGEST offset2
,
881 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
882 val2
, offset2
* TARGET_CHAR_BIT
,
883 length
* TARGET_CHAR_BIT
);
886 /* Prototypes for local functions. */
888 static void show_values (char *, int);
890 static void show_convenience (char *, int);
893 /* The value-history records all the values printed
894 by print commands during this session. Each chunk
895 records 60 consecutive values. The first chunk on
896 the chain records the most recent values.
897 The total number of values is in value_history_count. */
899 #define VALUE_HISTORY_CHUNK 60
901 struct value_history_chunk
903 struct value_history_chunk
*next
;
904 struct value
*values
[VALUE_HISTORY_CHUNK
];
907 /* Chain of chunks now in use. */
909 static struct value_history_chunk
*value_history_chain
;
911 static int value_history_count
; /* Abs number of last entry stored. */
914 /* List of all value objects currently allocated
915 (except for those released by calls to release_value)
916 This is so they can be freed after each command. */
918 static struct value
*all_values
;
920 /* Allocate a lazy value for type TYPE. Its actual content is
921 "lazily" allocated too: the content field of the return value is
922 NULL; it will be allocated when it is fetched from the target. */
925 allocate_value_lazy (struct type
*type
)
929 /* Call check_typedef on our type to make sure that, if TYPE
930 is a TYPE_CODE_TYPEDEF, its length is set to the length
931 of the target type instead of zero. However, we do not
932 replace the typedef type by the target type, because we want
933 to keep the typedef in order to be able to set the VAL's type
934 description correctly. */
935 check_typedef (type
);
937 val
= XCNEW (struct value
);
938 val
->contents
= NULL
;
939 val
->next
= all_values
;
942 val
->enclosing_type
= type
;
943 VALUE_LVAL (val
) = not_lval
;
944 val
->location
.address
= 0;
945 VALUE_FRAME_ID (val
) = null_frame_id
;
949 VALUE_REGNUM (val
) = -1;
951 val
->embedded_offset
= 0;
952 val
->pointed_to_offset
= 0;
954 val
->initialized
= 1; /* Default to initialized. */
956 /* Values start out on the all_values chain. */
957 val
->reference_count
= 1;
962 /* The maximum size, in bytes, that GDB will try to allocate for a value.
963 The initial value of 64k was not selected for any specific reason, it is
964 just a reasonable starting point. */
966 static int max_value_size
= 65536; /* 64k bytes */
968 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
969 LONGEST, otherwise GDB will not be able to parse integer values from the
970 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
971 be unable to parse "set max-value-size 2".
973 As we want a consistent GDB experience across hosts with different sizes
974 of LONGEST, this arbitrary minimum value was selected, so long as this
975 is bigger than LONGEST on all GDB supported hosts we're fine. */
977 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
978 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
980 /* Implement the "set max-value-size" command. */
983 set_max_value_size (char *args
, int from_tty
,
984 struct cmd_list_element
*c
)
986 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
988 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
990 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
991 error (_("max-value-size set too low, increasing to %d bytes"),
996 /* Implement the "show max-value-size" command. */
999 show_max_value_size (struct ui_file
*file
, int from_tty
,
1000 struct cmd_list_element
*c
, const char *value
)
1002 if (max_value_size
== -1)
1003 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
1005 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
1009 /* Called before we attempt to allocate or reallocate a buffer for the
1010 contents of a value. TYPE is the type of the value for which we are
1011 allocating the buffer. If the buffer is too large (based on the user
1012 controllable setting) then throw an error. If this function returns
1013 then we should attempt to allocate the buffer. */
1016 check_type_length_before_alloc (const struct type
*type
)
1018 unsigned int length
= TYPE_LENGTH (type
);
1020 if (max_value_size
> -1 && length
> max_value_size
)
1022 if (TYPE_NAME (type
) != NULL
)
1023 error (_("value of type `%s' requires %u bytes, which is more "
1024 "than max-value-size"), TYPE_NAME (type
), length
);
1026 error (_("value requires %u bytes, which is more than "
1027 "max-value-size"), length
);
1031 /* Allocate the contents of VAL if it has not been allocated yet. */
1034 allocate_value_contents (struct value
*val
)
1038 check_type_length_before_alloc (val
->enclosing_type
);
1040 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1044 /* Allocate a value and its contents for type TYPE. */
1047 allocate_value (struct type
*type
)
1049 struct value
*val
= allocate_value_lazy (type
);
1051 allocate_value_contents (val
);
1056 /* Allocate a value that has the correct length
1057 for COUNT repetitions of type TYPE. */
1060 allocate_repeat_value (struct type
*type
, int count
)
1062 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1063 /* FIXME-type-allocation: need a way to free this type when we are
1065 struct type
*array_type
1066 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1068 return allocate_value (array_type
);
1072 allocate_computed_value (struct type
*type
,
1073 const struct lval_funcs
*funcs
,
1076 struct value
*v
= allocate_value_lazy (type
);
1078 VALUE_LVAL (v
) = lval_computed
;
1079 v
->location
.computed
.funcs
= funcs
;
1080 v
->location
.computed
.closure
= closure
;
1085 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1088 allocate_optimized_out_value (struct type
*type
)
1090 struct value
*retval
= allocate_value_lazy (type
);
1092 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1093 set_value_lazy (retval
, 0);
1097 /* Accessor methods. */
1100 value_next (const struct value
*value
)
1106 value_type (const struct value
*value
)
1111 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1117 value_offset (const struct value
*value
)
1119 return value
->offset
;
1122 set_value_offset (struct value
*value
, LONGEST offset
)
1124 value
->offset
= offset
;
1128 value_bitpos (const struct value
*value
)
1130 return value
->bitpos
;
1133 set_value_bitpos (struct value
*value
, LONGEST bit
)
1135 value
->bitpos
= bit
;
1139 value_bitsize (const struct value
*value
)
1141 return value
->bitsize
;
1144 set_value_bitsize (struct value
*value
, LONGEST bit
)
1146 value
->bitsize
= bit
;
1150 value_parent (const struct value
*value
)
1152 return value
->parent
;
1158 set_value_parent (struct value
*value
, struct value
*parent
)
1160 struct value
*old
= value
->parent
;
1162 value
->parent
= parent
;
1164 value_incref (parent
);
1169 value_contents_raw (struct value
*value
)
1171 struct gdbarch
*arch
= get_value_arch (value
);
1172 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1174 allocate_value_contents (value
);
1175 return value
->contents
+ value
->embedded_offset
* unit_size
;
1179 value_contents_all_raw (struct value
*value
)
1181 allocate_value_contents (value
);
1182 return value
->contents
;
1186 value_enclosing_type (const struct value
*value
)
1188 return value
->enclosing_type
;
1191 /* Look at value.h for description. */
1194 value_actual_type (struct value
*value
, int resolve_simple_types
,
1195 int *real_type_found
)
1197 struct value_print_options opts
;
1198 struct type
*result
;
1200 get_user_print_options (&opts
);
1202 if (real_type_found
)
1203 *real_type_found
= 0;
1204 result
= value_type (value
);
1205 if (opts
.objectprint
)
1207 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1208 fetch its rtti type. */
1209 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1210 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1211 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1213 && !value_optimized_out (value
))
1215 struct type
*real_type
;
1217 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1220 if (real_type_found
)
1221 *real_type_found
= 1;
1225 else if (resolve_simple_types
)
1227 if (real_type_found
)
1228 *real_type_found
= 1;
1229 result
= value_enclosing_type (value
);
1237 error_value_optimized_out (void)
1239 error (_("value has been optimized out"));
1243 require_not_optimized_out (const struct value
*value
)
1245 if (!VEC_empty (range_s
, value
->optimized_out
))
1247 if (value
->lval
== lval_register
)
1248 error (_("register has not been saved in frame"));
1250 error_value_optimized_out ();
1255 require_available (const struct value
*value
)
1257 if (!VEC_empty (range_s
, value
->unavailable
))
1258 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1262 value_contents_for_printing (struct value
*value
)
1265 value_fetch_lazy (value
);
1266 return value
->contents
;
1270 value_contents_for_printing_const (const struct value
*value
)
1272 gdb_assert (!value
->lazy
);
1273 return value
->contents
;
1277 value_contents_all (struct value
*value
)
1279 const gdb_byte
*result
= value_contents_for_printing (value
);
1280 require_not_optimized_out (value
);
1281 require_available (value
);
1285 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1286 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1289 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1290 VEC (range_s
) *src_range
, int src_bit_offset
,
1296 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1300 l
= max (r
->offset
, src_bit_offset
);
1301 h
= min (r
->offset
+ r
->length
, src_bit_offset
+ bit_length
);
1304 insert_into_bit_range_vector (dst_range
,
1305 dst_bit_offset
+ (l
- src_bit_offset
),
1310 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1311 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1314 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1315 const struct value
*src
, int src_bit_offset
,
1318 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1319 src
->unavailable
, src_bit_offset
,
1321 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1322 src
->optimized_out
, src_bit_offset
,
1326 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1327 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1328 contents, starting at DST_OFFSET. If unavailable contents are
1329 being copied from SRC, the corresponding DST contents are marked
1330 unavailable accordingly. Neither DST nor SRC may be lazy
1333 It is assumed the contents of DST in the [DST_OFFSET,
1334 DST_OFFSET+LENGTH) range are wholly available. */
1337 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1338 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1340 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1341 struct gdbarch
*arch
= get_value_arch (src
);
1342 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1344 /* A lazy DST would make that this copy operation useless, since as
1345 soon as DST's contents were un-lazied (by a later value_contents
1346 call, say), the contents would be overwritten. A lazy SRC would
1347 mean we'd be copying garbage. */
1348 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1350 /* The overwritten DST range gets unavailability ORed in, not
1351 replaced. Make sure to remember to implement replacing if it
1352 turns out actually necessary. */
1353 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1354 gdb_assert (!value_bits_any_optimized_out (dst
,
1355 TARGET_CHAR_BIT
* dst_offset
,
1356 TARGET_CHAR_BIT
* length
));
1358 /* Copy the data. */
1359 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1360 value_contents_all_raw (src
) + src_offset
* unit_size
,
1361 length
* unit_size
);
1363 /* Copy the meta-data, adjusted. */
1364 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1365 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1366 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1368 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1369 src
, src_bit_offset
,
1373 /* Copy LENGTH bytes of SRC value's (all) contents
1374 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1375 (all) contents, starting at DST_OFFSET. If unavailable contents
1376 are being copied from SRC, the corresponding DST contents are
1377 marked unavailable accordingly. DST must not be lazy. If SRC is
1378 lazy, it will be fetched now.
1380 It is assumed the contents of DST in the [DST_OFFSET,
1381 DST_OFFSET+LENGTH) range are wholly available. */
1384 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1385 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1388 value_fetch_lazy (src
);
1390 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1394 value_lazy (const struct value
*value
)
1400 set_value_lazy (struct value
*value
, int val
)
1406 value_stack (const struct value
*value
)
1408 return value
->stack
;
1412 set_value_stack (struct value
*value
, int val
)
1418 value_contents (struct value
*value
)
1420 const gdb_byte
*result
= value_contents_writeable (value
);
1421 require_not_optimized_out (value
);
1422 require_available (value
);
1427 value_contents_writeable (struct value
*value
)
1430 value_fetch_lazy (value
);
1431 return value_contents_raw (value
);
1435 value_optimized_out (struct value
*value
)
1437 /* We can only know if a value is optimized out once we have tried to
1439 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1443 value_fetch_lazy (value
);
1445 CATCH (ex
, RETURN_MASK_ERROR
)
1447 /* Fall back to checking value->optimized_out. */
1452 return !VEC_empty (range_s
, value
->optimized_out
);
1455 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1456 the following LENGTH bytes. */
1459 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1461 mark_value_bits_optimized_out (value
,
1462 offset
* TARGET_CHAR_BIT
,
1463 length
* TARGET_CHAR_BIT
);
1469 mark_value_bits_optimized_out (struct value
*value
,
1470 LONGEST offset
, LONGEST length
)
1472 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1476 value_bits_synthetic_pointer (const struct value
*value
,
1477 LONGEST offset
, LONGEST length
)
1479 if (value
->lval
!= lval_computed
1480 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1482 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1488 value_embedded_offset (const struct value
*value
)
1490 return value
->embedded_offset
;
1494 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1496 value
->embedded_offset
= val
;
1500 value_pointed_to_offset (const struct value
*value
)
1502 return value
->pointed_to_offset
;
1506 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1508 value
->pointed_to_offset
= val
;
1511 const struct lval_funcs
*
1512 value_computed_funcs (const struct value
*v
)
1514 gdb_assert (value_lval_const (v
) == lval_computed
);
1516 return v
->location
.computed
.funcs
;
1520 value_computed_closure (const struct value
*v
)
1522 gdb_assert (v
->lval
== lval_computed
);
1524 return v
->location
.computed
.closure
;
1528 deprecated_value_lval_hack (struct value
*value
)
1530 return &value
->lval
;
1534 value_lval_const (const struct value
*value
)
1540 value_address (const struct value
*value
)
1542 if (value
->lval
== lval_internalvar
1543 || value
->lval
== lval_internalvar_component
1544 || value
->lval
== lval_xcallable
)
1546 if (value
->parent
!= NULL
)
1547 return value_address (value
->parent
) + value
->offset
;
1548 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1550 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1551 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1554 return value
->location
.address
+ value
->offset
;
1558 value_raw_address (const struct value
*value
)
1560 if (value
->lval
== lval_internalvar
1561 || value
->lval
== lval_internalvar_component
1562 || value
->lval
== lval_xcallable
)
1564 return value
->location
.address
;
1568 set_value_address (struct value
*value
, CORE_ADDR addr
)
1570 gdb_assert (value
->lval
!= lval_internalvar
1571 && value
->lval
!= lval_internalvar_component
1572 && value
->lval
!= lval_xcallable
);
1573 value
->location
.address
= addr
;
1576 struct internalvar
**
1577 deprecated_value_internalvar_hack (struct value
*value
)
1579 return &value
->location
.internalvar
;
1583 deprecated_value_frame_id_hack (struct value
*value
)
1585 return &value
->frame_id
;
1589 deprecated_value_regnum_hack (struct value
*value
)
1591 return &value
->regnum
;
1595 deprecated_value_modifiable (const struct value
*value
)
1597 return value
->modifiable
;
1600 /* Return a mark in the value chain. All values allocated after the
1601 mark is obtained (except for those released) are subject to being freed
1602 if a subsequent value_free_to_mark is passed the mark. */
1609 /* Take a reference to VAL. VAL will not be deallocated until all
1610 references are released. */
1613 value_incref (struct value
*val
)
1615 val
->reference_count
++;
1618 /* Release a reference to VAL, which was acquired with value_incref.
1619 This function is also called to deallocate values from the value
1623 value_free (struct value
*val
)
1627 gdb_assert (val
->reference_count
> 0);
1628 val
->reference_count
--;
1629 if (val
->reference_count
> 0)
1632 /* If there's an associated parent value, drop our reference to
1634 if (val
->parent
!= NULL
)
1635 value_free (val
->parent
);
1637 if (VALUE_LVAL (val
) == lval_computed
)
1639 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1641 if (funcs
->free_closure
)
1642 funcs
->free_closure (val
);
1644 else if (VALUE_LVAL (val
) == lval_xcallable
)
1645 free_xmethod_worker (val
->location
.xm_worker
);
1647 xfree (val
->contents
);
1648 VEC_free (range_s
, val
->unavailable
);
1653 /* Free all values allocated since MARK was obtained by value_mark
1654 (except for those released). */
1656 value_free_to_mark (const struct value
*mark
)
1661 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1670 /* Free all the values that have been allocated (except for those released).
1671 Call after each command, successful or not.
1672 In practice this is called before each command, which is sufficient. */
1675 free_all_values (void)
1680 for (val
= all_values
; val
; val
= next
)
1690 /* Frees all the elements in a chain of values. */
1693 free_value_chain (struct value
*v
)
1699 next
= value_next (v
);
1704 /* Remove VAL from the chain all_values
1705 so it will not be freed automatically. */
1708 release_value (struct value
*val
)
1712 if (all_values
== val
)
1714 all_values
= val
->next
;
1720 for (v
= all_values
; v
; v
= v
->next
)
1724 v
->next
= val
->next
;
1732 /* If the value is not already released, release it.
1733 If the value is already released, increment its reference count.
1734 That is, this function ensures that the value is released from the
1735 value chain and that the caller owns a reference to it. */
1738 release_value_or_incref (struct value
*val
)
1743 release_value (val
);
1746 /* Release all values up to mark */
1748 value_release_to_mark (const struct value
*mark
)
1753 for (val
= next
= all_values
; next
; next
= next
->next
)
1755 if (next
->next
== mark
)
1757 all_values
= next
->next
;
1767 /* Return a copy of the value ARG.
1768 It contains the same contents, for same memory address,
1769 but it's a different block of storage. */
1772 value_copy (struct value
*arg
)
1774 struct type
*encl_type
= value_enclosing_type (arg
);
1777 if (value_lazy (arg
))
1778 val
= allocate_value_lazy (encl_type
);
1780 val
= allocate_value (encl_type
);
1781 val
->type
= arg
->type
;
1782 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1783 val
->location
= arg
->location
;
1784 val
->offset
= arg
->offset
;
1785 val
->bitpos
= arg
->bitpos
;
1786 val
->bitsize
= arg
->bitsize
;
1787 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1788 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1789 val
->lazy
= arg
->lazy
;
1790 val
->embedded_offset
= value_embedded_offset (arg
);
1791 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1792 val
->modifiable
= arg
->modifiable
;
1793 if (!value_lazy (val
))
1795 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1796 TYPE_LENGTH (value_enclosing_type (arg
)));
1799 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1800 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1801 set_value_parent (val
, arg
->parent
);
1802 if (VALUE_LVAL (val
) == lval_computed
)
1804 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1806 if (funcs
->copy_closure
)
1807 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1812 /* Return a "const" and/or "volatile" qualified version of the value V.
1813 If CNST is true, then the returned value will be qualified with
1815 if VOLTL is true, then the returned value will be qualified with
1819 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1821 struct type
*val_type
= value_type (v
);
1822 struct type
*enclosing_type
= value_enclosing_type (v
);
1823 struct value
*cv_val
= value_copy (v
);
1825 deprecated_set_value_type (cv_val
,
1826 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1827 set_value_enclosing_type (cv_val
,
1828 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1833 /* Return a version of ARG that is non-lvalue. */
1836 value_non_lval (struct value
*arg
)
1838 if (VALUE_LVAL (arg
) != not_lval
)
1840 struct type
*enc_type
= value_enclosing_type (arg
);
1841 struct value
*val
= allocate_value (enc_type
);
1843 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1844 TYPE_LENGTH (enc_type
));
1845 val
->type
= arg
->type
;
1846 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1847 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1853 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1856 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1858 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1860 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1861 v
->lval
= lval_memory
;
1862 v
->location
.address
= addr
;
1866 set_value_component_location (struct value
*component
,
1867 const struct value
*whole
)
1871 gdb_assert (whole
->lval
!= lval_xcallable
);
1873 if (whole
->lval
== lval_internalvar
)
1874 VALUE_LVAL (component
) = lval_internalvar_component
;
1876 VALUE_LVAL (component
) = whole
->lval
;
1878 component
->location
= whole
->location
;
1879 if (whole
->lval
== lval_computed
)
1881 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1883 if (funcs
->copy_closure
)
1884 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1887 /* If type has a dynamic resolved location property
1888 update it's value address. */
1889 type
= value_type (whole
);
1890 if (NULL
!= TYPE_DATA_LOCATION (type
)
1891 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1892 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1895 /* Access to the value history. */
1897 /* Record a new value in the value history.
1898 Returns the absolute history index of the entry. */
1901 record_latest_value (struct value
*val
)
1905 /* We don't want this value to have anything to do with the inferior anymore.
1906 In particular, "set $1 = 50" should not affect the variable from which
1907 the value was taken, and fast watchpoints should be able to assume that
1908 a value on the value history never changes. */
1909 if (value_lazy (val
))
1910 value_fetch_lazy (val
);
1911 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1912 from. This is a bit dubious, because then *&$1 does not just return $1
1913 but the current contents of that location. c'est la vie... */
1914 val
->modifiable
= 0;
1916 /* The value may have already been released, in which case we're adding a
1917 new reference for its entry in the history. That is why we call
1918 release_value_or_incref here instead of release_value. */
1919 release_value_or_incref (val
);
1921 /* Here we treat value_history_count as origin-zero
1922 and applying to the value being stored now. */
1924 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1927 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1929 newobj
->next
= value_history_chain
;
1930 value_history_chain
= newobj
;
1933 value_history_chain
->values
[i
] = val
;
1935 /* Now we regard value_history_count as origin-one
1936 and applying to the value just stored. */
1938 return ++value_history_count
;
1941 /* Return a copy of the value in the history with sequence number NUM. */
1944 access_value_history (int num
)
1946 struct value_history_chunk
*chunk
;
1951 absnum
+= value_history_count
;
1956 error (_("The history is empty."));
1958 error (_("There is only one value in the history."));
1960 error (_("History does not go back to $$%d."), -num
);
1962 if (absnum
> value_history_count
)
1963 error (_("History has not yet reached $%d."), absnum
);
1967 /* Now absnum is always absolute and origin zero. */
1969 chunk
= value_history_chain
;
1970 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1971 - absnum
/ VALUE_HISTORY_CHUNK
;
1973 chunk
= chunk
->next
;
1975 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1979 show_values (char *num_exp
, int from_tty
)
1987 /* "show values +" should print from the stored position.
1988 "show values <exp>" should print around value number <exp>. */
1989 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1990 num
= parse_and_eval_long (num_exp
) - 5;
1994 /* "show values" means print the last 10 values. */
1995 num
= value_history_count
- 9;
2001 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
2003 struct value_print_options opts
;
2005 val
= access_value_history (i
);
2006 printf_filtered (("$%d = "), i
);
2007 get_user_print_options (&opts
);
2008 value_print (val
, gdb_stdout
, &opts
);
2009 printf_filtered (("\n"));
2012 /* The next "show values +" should start after what we just printed. */
2015 /* Hitting just return after this command should do the same thing as
2016 "show values +". If num_exp is null, this is unnecessary, since
2017 "show values +" is not useful after "show values". */
2018 if (from_tty
&& num_exp
)
2025 enum internalvar_kind
2027 /* The internal variable is empty. */
2030 /* The value of the internal variable is provided directly as
2031 a GDB value object. */
2034 /* A fresh value is computed via a call-back routine on every
2035 access to the internal variable. */
2036 INTERNALVAR_MAKE_VALUE
,
2038 /* The internal variable holds a GDB internal convenience function. */
2039 INTERNALVAR_FUNCTION
,
2041 /* The variable holds an integer value. */
2042 INTERNALVAR_INTEGER
,
2044 /* The variable holds a GDB-provided string. */
2048 union internalvar_data
2050 /* A value object used with INTERNALVAR_VALUE. */
2051 struct value
*value
;
2053 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2056 /* The functions to call. */
2057 const struct internalvar_funcs
*functions
;
2059 /* The function's user-data. */
2063 /* The internal function used with INTERNALVAR_FUNCTION. */
2066 struct internal_function
*function
;
2067 /* True if this is the canonical name for the function. */
2071 /* An integer value used with INTERNALVAR_INTEGER. */
2074 /* If type is non-NULL, it will be used as the type to generate
2075 a value for this internal variable. If type is NULL, a default
2076 integer type for the architecture is used. */
2081 /* A string value used with INTERNALVAR_STRING. */
2085 /* Internal variables. These are variables within the debugger
2086 that hold values assigned by debugger commands.
2087 The user refers to them with a '$' prefix
2088 that does not appear in the variable names stored internally. */
2092 struct internalvar
*next
;
2095 /* We support various different kinds of content of an internal variable.
2096 enum internalvar_kind specifies the kind, and union internalvar_data
2097 provides the data associated with this particular kind. */
2099 enum internalvar_kind kind
;
2101 union internalvar_data u
;
2104 static struct internalvar
*internalvars
;
2106 /* If the variable does not already exist create it and give it the
2107 value given. If no value is given then the default is zero. */
2109 init_if_undefined_command (char* args
, int from_tty
)
2111 struct internalvar
* intvar
;
2113 /* Parse the expression - this is taken from set_command(). */
2114 struct expression
*expr
= parse_expression (args
);
2115 register struct cleanup
*old_chain
=
2116 make_cleanup (free_current_contents
, &expr
);
2118 /* Validate the expression.
2119 Was the expression an assignment?
2120 Or even an expression at all? */
2121 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2122 error (_("Init-if-undefined requires an assignment expression."));
2124 /* Extract the variable from the parsed expression.
2125 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2126 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2127 error (_("The first parameter to init-if-undefined "
2128 "should be a GDB variable."));
2129 intvar
= expr
->elts
[2].internalvar
;
2131 /* Only evaluate the expression if the lvalue is void.
2132 This may still fail if the expresssion is invalid. */
2133 if (intvar
->kind
== INTERNALVAR_VOID
)
2134 evaluate_expression (expr
);
2136 do_cleanups (old_chain
);
2140 /* Look up an internal variable with name NAME. NAME should not
2141 normally include a dollar sign.
2143 If the specified internal variable does not exist,
2144 the return value is NULL. */
2146 struct internalvar
*
2147 lookup_only_internalvar (const char *name
)
2149 struct internalvar
*var
;
2151 for (var
= internalvars
; var
; var
= var
->next
)
2152 if (strcmp (var
->name
, name
) == 0)
2158 /* Complete NAME by comparing it to the names of internal variables.
2159 Returns a vector of newly allocated strings, or NULL if no matches
2163 complete_internalvar (const char *name
)
2165 VEC (char_ptr
) *result
= NULL
;
2166 struct internalvar
*var
;
2169 len
= strlen (name
);
2171 for (var
= internalvars
; var
; var
= var
->next
)
2172 if (strncmp (var
->name
, name
, len
) == 0)
2174 char *r
= xstrdup (var
->name
);
2176 VEC_safe_push (char_ptr
, result
, r
);
2182 /* Create an internal variable with name NAME and with a void value.
2183 NAME should not normally include a dollar sign. */
2185 struct internalvar
*
2186 create_internalvar (const char *name
)
2188 struct internalvar
*var
= XNEW (struct internalvar
);
2190 var
->name
= concat (name
, (char *)NULL
);
2191 var
->kind
= INTERNALVAR_VOID
;
2192 var
->next
= internalvars
;
2197 /* Create an internal variable with name NAME and register FUN as the
2198 function that value_of_internalvar uses to create a value whenever
2199 this variable is referenced. NAME should not normally include a
2200 dollar sign. DATA is passed uninterpreted to FUN when it is
2201 called. CLEANUP, if not NULL, is called when the internal variable
2202 is destroyed. It is passed DATA as its only argument. */
2204 struct internalvar
*
2205 create_internalvar_type_lazy (const char *name
,
2206 const struct internalvar_funcs
*funcs
,
2209 struct internalvar
*var
= create_internalvar (name
);
2211 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2212 var
->u
.make_value
.functions
= funcs
;
2213 var
->u
.make_value
.data
= data
;
2217 /* See documentation in value.h. */
2220 compile_internalvar_to_ax (struct internalvar
*var
,
2221 struct agent_expr
*expr
,
2222 struct axs_value
*value
)
2224 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2225 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2228 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2229 var
->u
.make_value
.data
);
2233 /* Look up an internal variable with name NAME. NAME should not
2234 normally include a dollar sign.
2236 If the specified internal variable does not exist,
2237 one is created, with a void value. */
2239 struct internalvar
*
2240 lookup_internalvar (const char *name
)
2242 struct internalvar
*var
;
2244 var
= lookup_only_internalvar (name
);
2248 return create_internalvar (name
);
2251 /* Return current value of internal variable VAR. For variables that
2252 are not inherently typed, use a value type appropriate for GDBARCH. */
2255 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2258 struct trace_state_variable
*tsv
;
2260 /* If there is a trace state variable of the same name, assume that
2261 is what we really want to see. */
2262 tsv
= find_trace_state_variable (var
->name
);
2265 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2267 if (tsv
->value_known
)
2268 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2271 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2277 case INTERNALVAR_VOID
:
2278 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2281 case INTERNALVAR_FUNCTION
:
2282 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2285 case INTERNALVAR_INTEGER
:
2286 if (!var
->u
.integer
.type
)
2287 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2288 var
->u
.integer
.val
);
2290 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2293 case INTERNALVAR_STRING
:
2294 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2295 builtin_type (gdbarch
)->builtin_char
);
2298 case INTERNALVAR_VALUE
:
2299 val
= value_copy (var
->u
.value
);
2300 if (value_lazy (val
))
2301 value_fetch_lazy (val
);
2304 case INTERNALVAR_MAKE_VALUE
:
2305 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2306 var
->u
.make_value
.data
);
2310 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2313 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2314 on this value go back to affect the original internal variable.
2316 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2317 no underlying modifyable state in the internal variable.
2319 Likewise, if the variable's value is a computed lvalue, we want
2320 references to it to produce another computed lvalue, where
2321 references and assignments actually operate through the
2322 computed value's functions.
2324 This means that internal variables with computed values
2325 behave a little differently from other internal variables:
2326 assignments to them don't just replace the previous value
2327 altogether. At the moment, this seems like the behavior we
2330 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2331 && val
->lval
!= lval_computed
)
2333 VALUE_LVAL (val
) = lval_internalvar
;
2334 VALUE_INTERNALVAR (val
) = var
;
2341 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2343 if (var
->kind
== INTERNALVAR_INTEGER
)
2345 *result
= var
->u
.integer
.val
;
2349 if (var
->kind
== INTERNALVAR_VALUE
)
2351 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2353 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2355 *result
= value_as_long (var
->u
.value
);
2364 get_internalvar_function (struct internalvar
*var
,
2365 struct internal_function
**result
)
2369 case INTERNALVAR_FUNCTION
:
2370 *result
= var
->u
.fn
.function
;
2379 set_internalvar_component (struct internalvar
*var
,
2380 LONGEST offset
, LONGEST bitpos
,
2381 LONGEST bitsize
, struct value
*newval
)
2384 struct gdbarch
*arch
;
2389 case INTERNALVAR_VALUE
:
2390 addr
= value_contents_writeable (var
->u
.value
);
2391 arch
= get_value_arch (var
->u
.value
);
2392 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2395 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2396 value_as_long (newval
), bitpos
, bitsize
);
2398 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2399 TYPE_LENGTH (value_type (newval
)));
2403 /* We can never get a component of any other kind. */
2404 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2409 set_internalvar (struct internalvar
*var
, struct value
*val
)
2411 enum internalvar_kind new_kind
;
2412 union internalvar_data new_data
= { 0 };
2414 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2415 error (_("Cannot overwrite convenience function %s"), var
->name
);
2417 /* Prepare new contents. */
2418 switch (TYPE_CODE (check_typedef (value_type (val
))))
2420 case TYPE_CODE_VOID
:
2421 new_kind
= INTERNALVAR_VOID
;
2424 case TYPE_CODE_INTERNAL_FUNCTION
:
2425 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2426 new_kind
= INTERNALVAR_FUNCTION
;
2427 get_internalvar_function (VALUE_INTERNALVAR (val
),
2428 &new_data
.fn
.function
);
2429 /* Copies created here are never canonical. */
2433 new_kind
= INTERNALVAR_VALUE
;
2434 new_data
.value
= value_copy (val
);
2435 new_data
.value
->modifiable
= 1;
2437 /* Force the value to be fetched from the target now, to avoid problems
2438 later when this internalvar is referenced and the target is gone or
2440 if (value_lazy (new_data
.value
))
2441 value_fetch_lazy (new_data
.value
);
2443 /* Release the value from the value chain to prevent it from being
2444 deleted by free_all_values. From here on this function should not
2445 call error () until new_data is installed into the var->u to avoid
2447 release_value (new_data
.value
);
2449 /* Internal variables which are created from values with a dynamic
2450 location don't need the location property of the origin anymore.
2451 The resolved dynamic location is used prior then any other address
2452 when accessing the value.
2453 If we keep it, we would still refer to the origin value.
2454 Remove the location property in case it exist. */
2455 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2460 /* Clean up old contents. */
2461 clear_internalvar (var
);
2464 var
->kind
= new_kind
;
2466 /* End code which must not call error(). */
2470 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2472 /* Clean up old contents. */
2473 clear_internalvar (var
);
2475 var
->kind
= INTERNALVAR_INTEGER
;
2476 var
->u
.integer
.type
= NULL
;
2477 var
->u
.integer
.val
= l
;
2481 set_internalvar_string (struct internalvar
*var
, const char *string
)
2483 /* Clean up old contents. */
2484 clear_internalvar (var
);
2486 var
->kind
= INTERNALVAR_STRING
;
2487 var
->u
.string
= xstrdup (string
);
2491 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2493 /* Clean up old contents. */
2494 clear_internalvar (var
);
2496 var
->kind
= INTERNALVAR_FUNCTION
;
2497 var
->u
.fn
.function
= f
;
2498 var
->u
.fn
.canonical
= 1;
2499 /* Variables installed here are always the canonical version. */
2503 clear_internalvar (struct internalvar
*var
)
2505 /* Clean up old contents. */
2508 case INTERNALVAR_VALUE
:
2509 value_free (var
->u
.value
);
2512 case INTERNALVAR_STRING
:
2513 xfree (var
->u
.string
);
2516 case INTERNALVAR_MAKE_VALUE
:
2517 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2518 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2525 /* Reset to void kind. */
2526 var
->kind
= INTERNALVAR_VOID
;
2530 internalvar_name (const struct internalvar
*var
)
2535 static struct internal_function
*
2536 create_internal_function (const char *name
,
2537 internal_function_fn handler
, void *cookie
)
2539 struct internal_function
*ifn
= XNEW (struct internal_function
);
2541 ifn
->name
= xstrdup (name
);
2542 ifn
->handler
= handler
;
2543 ifn
->cookie
= cookie
;
2548 value_internal_function_name (struct value
*val
)
2550 struct internal_function
*ifn
;
2553 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2554 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2555 gdb_assert (result
);
2561 call_internal_function (struct gdbarch
*gdbarch
,
2562 const struct language_defn
*language
,
2563 struct value
*func
, int argc
, struct value
**argv
)
2565 struct internal_function
*ifn
;
2568 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2569 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2570 gdb_assert (result
);
2572 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2575 /* The 'function' command. This does nothing -- it is just a
2576 placeholder to let "help function NAME" work. This is also used as
2577 the implementation of the sub-command that is created when
2578 registering an internal function. */
2580 function_command (char *command
, int from_tty
)
2585 /* Clean up if an internal function's command is destroyed. */
2587 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2589 xfree ((char *) self
->name
);
2590 xfree ((char *) self
->doc
);
2593 /* Add a new internal function. NAME is the name of the function; DOC
2594 is a documentation string describing the function. HANDLER is
2595 called when the function is invoked. COOKIE is an arbitrary
2596 pointer which is passed to HANDLER and is intended for "user
2599 add_internal_function (const char *name
, const char *doc
,
2600 internal_function_fn handler
, void *cookie
)
2602 struct cmd_list_element
*cmd
;
2603 struct internal_function
*ifn
;
2604 struct internalvar
*var
= lookup_internalvar (name
);
2606 ifn
= create_internal_function (name
, handler
, cookie
);
2607 set_internalvar_function (var
, ifn
);
2609 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2611 cmd
->destroyer
= function_destroyer
;
2614 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2615 prevent cycles / duplicates. */
2618 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2619 htab_t copied_types
)
2621 if (TYPE_OBJFILE (value
->type
) == objfile
)
2622 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2624 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2625 value
->enclosing_type
= copy_type_recursive (objfile
,
2626 value
->enclosing_type
,
2630 /* Likewise for internal variable VAR. */
2633 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2634 htab_t copied_types
)
2638 case INTERNALVAR_INTEGER
:
2639 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2641 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2644 case INTERNALVAR_VALUE
:
2645 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2650 /* Update the internal variables and value history when OBJFILE is
2651 discarded; we must copy the types out of the objfile. New global types
2652 will be created for every convenience variable which currently points to
2653 this objfile's types, and the convenience variables will be adjusted to
2654 use the new global types. */
2657 preserve_values (struct objfile
*objfile
)
2659 htab_t copied_types
;
2660 struct value_history_chunk
*cur
;
2661 struct internalvar
*var
;
2664 /* Create the hash table. We allocate on the objfile's obstack, since
2665 it is soon to be deleted. */
2666 copied_types
= create_copied_types_hash (objfile
);
2668 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2669 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2671 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2673 for (var
= internalvars
; var
; var
= var
->next
)
2674 preserve_one_internalvar (var
, objfile
, copied_types
);
2676 preserve_ext_lang_values (objfile
, copied_types
);
2678 htab_delete (copied_types
);
2682 show_convenience (char *ignore
, int from_tty
)
2684 struct gdbarch
*gdbarch
= get_current_arch ();
2685 struct internalvar
*var
;
2687 struct value_print_options opts
;
2689 get_user_print_options (&opts
);
2690 for (var
= internalvars
; var
; var
= var
->next
)
2697 printf_filtered (("$%s = "), var
->name
);
2703 val
= value_of_internalvar (gdbarch
, var
);
2704 value_print (val
, gdb_stdout
, &opts
);
2706 CATCH (ex
, RETURN_MASK_ERROR
)
2708 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2712 printf_filtered (("\n"));
2716 /* This text does not mention convenience functions on purpose.
2717 The user can't create them except via Python, and if Python support
2718 is installed this message will never be printed ($_streq will
2720 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2721 "Convenience variables have "
2722 "names starting with \"$\";\n"
2723 "use \"set\" as in \"set "
2724 "$foo = 5\" to define them.\n"));
2728 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2731 value_of_xmethod (struct xmethod_worker
*worker
)
2733 if (worker
->value
== NULL
)
2737 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2738 v
->lval
= lval_xcallable
;
2739 v
->location
.xm_worker
= worker
;
2744 return worker
->value
;
2747 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2750 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2752 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2753 && method
->lval
== lval_xcallable
&& argc
> 0);
2755 return get_xmethod_result_type (method
->location
.xm_worker
,
2756 argv
[0], argv
+ 1, argc
- 1);
2759 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2762 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2764 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2765 && method
->lval
== lval_xcallable
&& argc
> 0);
2767 return invoke_xmethod (method
->location
.xm_worker
,
2768 argv
[0], argv
+ 1, argc
- 1);
2771 /* Extract a value as a C number (either long or double).
2772 Knows how to convert fixed values to double, or
2773 floating values to long.
2774 Does not deallocate the value. */
2777 value_as_long (struct value
*val
)
2779 /* This coerces arrays and functions, which is necessary (e.g.
2780 in disassemble_command). It also dereferences references, which
2781 I suspect is the most logical thing to do. */
2782 val
= coerce_array (val
);
2783 return unpack_long (value_type (val
), value_contents (val
));
2787 value_as_double (struct value
*val
)
2792 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2794 error (_("Invalid floating value found in program."));
2798 /* Extract a value as a C pointer. Does not deallocate the value.
2799 Note that val's type may not actually be a pointer; value_as_long
2800 handles all the cases. */
2802 value_as_address (struct value
*val
)
2804 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2806 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2807 whether we want this to be true eventually. */
2809 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2810 non-address (e.g. argument to "signal", "info break", etc.), or
2811 for pointers to char, in which the low bits *are* significant. */
2812 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2815 /* There are several targets (IA-64, PowerPC, and others) which
2816 don't represent pointers to functions as simply the address of
2817 the function's entry point. For example, on the IA-64, a
2818 function pointer points to a two-word descriptor, generated by
2819 the linker, which contains the function's entry point, and the
2820 value the IA-64 "global pointer" register should have --- to
2821 support position-independent code. The linker generates
2822 descriptors only for those functions whose addresses are taken.
2824 On such targets, it's difficult for GDB to convert an arbitrary
2825 function address into a function pointer; it has to either find
2826 an existing descriptor for that function, or call malloc and
2827 build its own. On some targets, it is impossible for GDB to
2828 build a descriptor at all: the descriptor must contain a jump
2829 instruction; data memory cannot be executed; and code memory
2832 Upon entry to this function, if VAL is a value of type `function'
2833 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2834 value_address (val) is the address of the function. This is what
2835 you'll get if you evaluate an expression like `main'. The call
2836 to COERCE_ARRAY below actually does all the usual unary
2837 conversions, which includes converting values of type `function'
2838 to `pointer to function'. This is the challenging conversion
2839 discussed above. Then, `unpack_long' will convert that pointer
2840 back into an address.
2842 So, suppose the user types `disassemble foo' on an architecture
2843 with a strange function pointer representation, on which GDB
2844 cannot build its own descriptors, and suppose further that `foo'
2845 has no linker-built descriptor. The address->pointer conversion
2846 will signal an error and prevent the command from running, even
2847 though the next step would have been to convert the pointer
2848 directly back into the same address.
2850 The following shortcut avoids this whole mess. If VAL is a
2851 function, just return its address directly. */
2852 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2853 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2854 return value_address (val
);
2856 val
= coerce_array (val
);
2858 /* Some architectures (e.g. Harvard), map instruction and data
2859 addresses onto a single large unified address space. For
2860 instance: An architecture may consider a large integer in the
2861 range 0x10000000 .. 0x1000ffff to already represent a data
2862 addresses (hence not need a pointer to address conversion) while
2863 a small integer would still need to be converted integer to
2864 pointer to address. Just assume such architectures handle all
2865 integer conversions in a single function. */
2869 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2870 must admonish GDB hackers to make sure its behavior matches the
2871 compiler's, whenever possible.
2873 In general, I think GDB should evaluate expressions the same way
2874 the compiler does. When the user copies an expression out of
2875 their source code and hands it to a `print' command, they should
2876 get the same value the compiler would have computed. Any
2877 deviation from this rule can cause major confusion and annoyance,
2878 and needs to be justified carefully. In other words, GDB doesn't
2879 really have the freedom to do these conversions in clever and
2882 AndrewC pointed out that users aren't complaining about how GDB
2883 casts integers to pointers; they are complaining that they can't
2884 take an address from a disassembly listing and give it to `x/i'.
2885 This is certainly important.
2887 Adding an architecture method like integer_to_address() certainly
2888 makes it possible for GDB to "get it right" in all circumstances
2889 --- the target has complete control over how things get done, so
2890 people can Do The Right Thing for their target without breaking
2891 anyone else. The standard doesn't specify how integers get
2892 converted to pointers; usually, the ABI doesn't either, but
2893 ABI-specific code is a more reasonable place to handle it. */
2895 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2896 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2897 && gdbarch_integer_to_address_p (gdbarch
))
2898 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2899 value_contents (val
));
2901 return unpack_long (value_type (val
), value_contents (val
));
2905 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2906 as a long, or as a double, assuming the raw data is described
2907 by type TYPE. Knows how to convert different sizes of values
2908 and can convert between fixed and floating point. We don't assume
2909 any alignment for the raw data. Return value is in host byte order.
2911 If you want functions and arrays to be coerced to pointers, and
2912 references to be dereferenced, call value_as_long() instead.
2914 C++: It is assumed that the front-end has taken care of
2915 all matters concerning pointers to members. A pointer
2916 to member which reaches here is considered to be equivalent
2917 to an INT (or some size). After all, it is only an offset. */
2920 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2922 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2923 enum type_code code
= TYPE_CODE (type
);
2924 int len
= TYPE_LENGTH (type
);
2925 int nosign
= TYPE_UNSIGNED (type
);
2929 case TYPE_CODE_TYPEDEF
:
2930 return unpack_long (check_typedef (type
), valaddr
);
2931 case TYPE_CODE_ENUM
:
2932 case TYPE_CODE_FLAGS
:
2933 case TYPE_CODE_BOOL
:
2935 case TYPE_CODE_CHAR
:
2936 case TYPE_CODE_RANGE
:
2937 case TYPE_CODE_MEMBERPTR
:
2939 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2941 return extract_signed_integer (valaddr
, len
, byte_order
);
2944 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2946 case TYPE_CODE_DECFLOAT
:
2947 /* libdecnumber has a function to convert from decimal to integer, but
2948 it doesn't work when the decimal number has a fractional part. */
2949 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2953 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2954 whether we want this to be true eventually. */
2955 return extract_typed_address (valaddr
, type
);
2958 error (_("Value can't be converted to integer."));
2960 return 0; /* Placate lint. */
2963 /* Return a double value from the specified type and address.
2964 INVP points to an int which is set to 0 for valid value,
2965 1 for invalid value (bad float format). In either case,
2966 the returned double is OK to use. Argument is in target
2967 format, result is in host format. */
2970 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2972 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2973 enum type_code code
;
2977 *invp
= 0; /* Assume valid. */
2978 type
= check_typedef (type
);
2979 code
= TYPE_CODE (type
);
2980 len
= TYPE_LENGTH (type
);
2981 nosign
= TYPE_UNSIGNED (type
);
2982 if (code
== TYPE_CODE_FLT
)
2984 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2985 floating-point value was valid (using the macro
2986 INVALID_FLOAT). That test/macro have been removed.
2988 It turns out that only the VAX defined this macro and then
2989 only in a non-portable way. Fixing the portability problem
2990 wouldn't help since the VAX floating-point code is also badly
2991 bit-rotten. The target needs to add definitions for the
2992 methods gdbarch_float_format and gdbarch_double_format - these
2993 exactly describe the target floating-point format. The
2994 problem here is that the corresponding floatformat_vax_f and
2995 floatformat_vax_d values these methods should be set to are
2996 also not defined either. Oops!
2998 Hopefully someone will add both the missing floatformat
2999 definitions and the new cases for floatformat_is_valid (). */
3001 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
3007 return extract_typed_floating (valaddr
, type
);
3009 else if (code
== TYPE_CODE_DECFLOAT
)
3010 return decimal_to_doublest (valaddr
, len
, byte_order
);
3013 /* Unsigned -- be sure we compensate for signed LONGEST. */
3014 return (ULONGEST
) unpack_long (type
, valaddr
);
3018 /* Signed -- we are OK with unpack_long. */
3019 return unpack_long (type
, valaddr
);
3023 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3024 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3025 We don't assume any alignment for the raw data. Return value is in
3028 If you want functions and arrays to be coerced to pointers, and
3029 references to be dereferenced, call value_as_address() instead.
3031 C++: It is assumed that the front-end has taken care of
3032 all matters concerning pointers to members. A pointer
3033 to member which reaches here is considered to be equivalent
3034 to an INT (or some size). After all, it is only an offset. */
3037 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3039 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3040 whether we want this to be true eventually. */
3041 return unpack_long (type
, valaddr
);
3045 /* Get the value of the FIELDNO'th field (which must be static) of
3049 value_static_field (struct type
*type
, int fieldno
)
3051 struct value
*retval
;
3053 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3055 case FIELD_LOC_KIND_PHYSADDR
:
3056 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3057 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3059 case FIELD_LOC_KIND_PHYSNAME
:
3061 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3062 /* TYPE_FIELD_NAME (type, fieldno); */
3063 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3065 if (sym
.symbol
== NULL
)
3067 /* With some compilers, e.g. HP aCC, static data members are
3068 reported as non-debuggable symbols. */
3069 struct bound_minimal_symbol msym
3070 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3073 return allocate_optimized_out_value (type
);
3076 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3077 BMSYMBOL_VALUE_ADDRESS (msym
));
3081 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3085 gdb_assert_not_reached ("unexpected field location kind");
3091 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3092 You have to be careful here, since the size of the data area for the value
3093 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3094 than the old enclosing type, you have to allocate more space for the
3098 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3100 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3102 check_type_length_before_alloc (new_encl_type
);
3104 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3107 val
->enclosing_type
= new_encl_type
;
3110 /* Given a value ARG1 (offset by OFFSET bytes)
3111 of a struct or union type ARG_TYPE,
3112 extract and return the value of one of its (non-static) fields.
3113 FIELDNO says which field. */
3116 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3117 int fieldno
, struct type
*arg_type
)
3121 struct gdbarch
*arch
= get_value_arch (arg1
);
3122 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3124 arg_type
= check_typedef (arg_type
);
3125 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3127 /* Call check_typedef on our type to make sure that, if TYPE
3128 is a TYPE_CODE_TYPEDEF, its length is set to the length
3129 of the target type instead of zero. However, we do not
3130 replace the typedef type by the target type, because we want
3131 to keep the typedef in order to be able to print the type
3132 description correctly. */
3133 check_typedef (type
);
3135 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3137 /* Handle packed fields.
3139 Create a new value for the bitfield, with bitpos and bitsize
3140 set. If possible, arrange offset and bitpos so that we can
3141 do a single aligned read of the size of the containing type.
3142 Otherwise, adjust offset to the byte containing the first
3143 bit. Assume that the address, offset, and embedded offset
3144 are sufficiently aligned. */
3146 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3147 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3149 v
= allocate_value_lazy (type
);
3150 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3151 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3152 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3153 v
->bitpos
= bitpos
% container_bitsize
;
3155 v
->bitpos
= bitpos
% 8;
3156 v
->offset
= (value_embedded_offset (arg1
)
3158 + (bitpos
- v
->bitpos
) / 8);
3159 set_value_parent (v
, arg1
);
3160 if (!value_lazy (arg1
))
3161 value_fetch_lazy (v
);
3163 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3165 /* This field is actually a base subobject, so preserve the
3166 entire object's contents for later references to virtual
3170 /* Lazy register values with offsets are not supported. */
3171 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3172 value_fetch_lazy (arg1
);
3174 /* We special case virtual inheritance here because this
3175 requires access to the contents, which we would rather avoid
3176 for references to ordinary fields of unavailable values. */
3177 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3178 boffset
= baseclass_offset (arg_type
, fieldno
,
3179 value_contents (arg1
),
3180 value_embedded_offset (arg1
),
3181 value_address (arg1
),
3184 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3186 if (value_lazy (arg1
))
3187 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3190 v
= allocate_value (value_enclosing_type (arg1
));
3191 value_contents_copy_raw (v
, 0, arg1
, 0,
3192 TYPE_LENGTH (value_enclosing_type (arg1
)));
3195 v
->offset
= value_offset (arg1
);
3196 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3198 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3200 /* Field is a dynamic data member. */
3202 gdb_assert (0 == offset
);
3203 /* We expect an already resolved data location. */
3204 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3205 /* For dynamic data types defer memory allocation
3206 until we actual access the value. */
3207 v
= allocate_value_lazy (type
);
3211 /* Plain old data member */
3212 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3213 / (HOST_CHAR_BIT
* unit_size
));
3215 /* Lazy register values with offsets are not supported. */
3216 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3217 value_fetch_lazy (arg1
);
3219 if (value_lazy (arg1
))
3220 v
= allocate_value_lazy (type
);
3223 v
= allocate_value (type
);
3224 value_contents_copy_raw (v
, value_embedded_offset (v
),
3225 arg1
, value_embedded_offset (arg1
) + offset
,
3226 type_length_units (type
));
3228 v
->offset
= (value_offset (arg1
) + offset
3229 + value_embedded_offset (arg1
));
3231 set_value_component_location (v
, arg1
);
3232 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
3233 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
3237 /* Given a value ARG1 of a struct or union type,
3238 extract and return the value of one of its (non-static) fields.
3239 FIELDNO says which field. */
3242 value_field (struct value
*arg1
, int fieldno
)
3244 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3247 /* Return a non-virtual function as a value.
3248 F is the list of member functions which contains the desired method.
3249 J is an index into F which provides the desired method.
3251 We only use the symbol for its address, so be happy with either a
3252 full symbol or a minimal symbol. */
3255 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3256 int j
, struct type
*type
,
3260 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3261 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3263 struct bound_minimal_symbol msym
;
3265 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3268 memset (&msym
, 0, sizeof (msym
));
3272 gdb_assert (sym
== NULL
);
3273 msym
= lookup_bound_minimal_symbol (physname
);
3274 if (msym
.minsym
== NULL
)
3278 v
= allocate_value (ftype
);
3281 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3285 /* The minimal symbol might point to a function descriptor;
3286 resolve it to the actual code address instead. */
3287 struct objfile
*objfile
= msym
.objfile
;
3288 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3290 set_value_address (v
,
3291 gdbarch_convert_from_func_ptr_addr
3292 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3297 if (type
!= value_type (*arg1p
))
3298 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3299 value_addr (*arg1p
)));
3301 /* Move the `this' pointer according to the offset.
3302 VALUE_OFFSET (*arg1p) += offset; */
3310 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3311 VALADDR, and store the result in *RESULT.
3312 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3314 Extracting bits depends on endianness of the machine. Compute the
3315 number of least significant bits to discard. For big endian machines,
3316 we compute the total number of bits in the anonymous object, subtract
3317 off the bit count from the MSB of the object to the MSB of the
3318 bitfield, then the size of the bitfield, which leaves the LSB discard
3319 count. For little endian machines, the discard count is simply the
3320 number of bits from the LSB of the anonymous object to the LSB of the
3323 If the field is signed, we also do sign extension. */
3326 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3327 LONGEST bitpos
, LONGEST bitsize
)
3329 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3334 LONGEST read_offset
;
3336 /* Read the minimum number of bytes required; there may not be
3337 enough bytes to read an entire ULONGEST. */
3338 field_type
= check_typedef (field_type
);
3340 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3342 bytes_read
= TYPE_LENGTH (field_type
);
3344 read_offset
= bitpos
/ 8;
3346 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3347 bytes_read
, byte_order
);
3349 /* Extract bits. See comment above. */
3351 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3352 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3354 lsbcount
= (bitpos
% 8);
3357 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3358 If the field is signed, and is negative, then sign extend. */
3360 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3362 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3364 if (!TYPE_UNSIGNED (field_type
))
3366 if (val
& (valmask
^ (valmask
>> 1)))
3376 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3377 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3378 ORIGINAL_VALUE, which must not be NULL. See
3379 unpack_value_bits_as_long for more details. */
3382 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3383 LONGEST embedded_offset
, int fieldno
,
3384 const struct value
*val
, LONGEST
*result
)
3386 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3387 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3388 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3391 gdb_assert (val
!= NULL
);
3393 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3394 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3395 || !value_bits_available (val
, bit_offset
, bitsize
))
3398 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3403 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3404 object at VALADDR. See unpack_bits_as_long for more details. */
3407 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3409 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3410 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3411 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3413 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3416 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3417 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3418 the contents in DEST_VAL, zero or sign extending if the type of
3419 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3420 VAL. If the VAL's contents required to extract the bitfield from
3421 are unavailable/optimized out, DEST_VAL is correspondingly
3422 marked unavailable/optimized out. */
3425 unpack_value_bitfield (struct value
*dest_val
,
3426 LONGEST bitpos
, LONGEST bitsize
,
3427 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3428 const struct value
*val
)
3430 enum bfd_endian byte_order
;
3434 struct type
*field_type
= value_type (dest_val
);
3436 /* First, unpack and sign extend the bitfield as if it was wholly
3437 available. Invalid/unavailable bits are read as zero, but that's
3438 OK, as they'll end up marked below. */
3439 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3440 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3442 store_signed_integer (value_contents_raw (dest_val
),
3443 TYPE_LENGTH (field_type
), byte_order
, num
);
3445 /* Now copy the optimized out / unavailability ranges to the right
3447 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3448 if (byte_order
== BFD_ENDIAN_BIG
)
3449 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3452 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3453 val
, src_bit_offset
, bitsize
);
3456 /* Return a new value with type TYPE, which is FIELDNO field of the
3457 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3458 of VAL. If the VAL's contents required to extract the bitfield
3459 from are unavailable/optimized out, the new value is
3460 correspondingly marked unavailable/optimized out. */
3463 value_field_bitfield (struct type
*type
, int fieldno
,
3464 const gdb_byte
*valaddr
,
3465 LONGEST embedded_offset
, const struct value
*val
)
3467 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3468 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3469 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3471 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3472 valaddr
, embedded_offset
, val
);
3477 /* Modify the value of a bitfield. ADDR points to a block of memory in
3478 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3479 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3480 indicate which bits (in target bit order) comprise the bitfield.
3481 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3482 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3485 modify_field (struct type
*type
, gdb_byte
*addr
,
3486 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3488 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3490 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3493 /* Normalize BITPOS. */
3497 /* If a negative fieldval fits in the field in question, chop
3498 off the sign extension bits. */
3499 if ((~fieldval
& ~(mask
>> 1)) == 0)
3502 /* Warn if value is too big to fit in the field in question. */
3503 if (0 != (fieldval
& ~mask
))
3505 /* FIXME: would like to include fieldval in the message, but
3506 we don't have a sprintf_longest. */
3507 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3509 /* Truncate it, otherwise adjoining fields may be corrupted. */
3513 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3514 false valgrind reports. */
3516 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3517 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3519 /* Shifting for bit field depends on endianness of the target machine. */
3520 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3521 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3523 oword
&= ~(mask
<< bitpos
);
3524 oword
|= fieldval
<< bitpos
;
3526 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3529 /* Pack NUM into BUF using a target format of TYPE. */
3532 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3534 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3537 type
= check_typedef (type
);
3538 len
= TYPE_LENGTH (type
);
3540 switch (TYPE_CODE (type
))
3543 case TYPE_CODE_CHAR
:
3544 case TYPE_CODE_ENUM
:
3545 case TYPE_CODE_FLAGS
:
3546 case TYPE_CODE_BOOL
:
3547 case TYPE_CODE_RANGE
:
3548 case TYPE_CODE_MEMBERPTR
:
3549 store_signed_integer (buf
, len
, byte_order
, num
);
3554 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3558 error (_("Unexpected type (%d) encountered for integer constant."),
3564 /* Pack NUM into BUF using a target format of TYPE. */
3567 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3570 enum bfd_endian byte_order
;
3572 type
= check_typedef (type
);
3573 len
= TYPE_LENGTH (type
);
3574 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3576 switch (TYPE_CODE (type
))
3579 case TYPE_CODE_CHAR
:
3580 case TYPE_CODE_ENUM
:
3581 case TYPE_CODE_FLAGS
:
3582 case TYPE_CODE_BOOL
:
3583 case TYPE_CODE_RANGE
:
3584 case TYPE_CODE_MEMBERPTR
:
3585 store_unsigned_integer (buf
, len
, byte_order
, num
);
3590 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3594 error (_("Unexpected type (%d) encountered "
3595 "for unsigned integer constant."),
3601 /* Convert C numbers into newly allocated values. */
3604 value_from_longest (struct type
*type
, LONGEST num
)
3606 struct value
*val
= allocate_value (type
);
3608 pack_long (value_contents_raw (val
), type
, num
);
3613 /* Convert C unsigned numbers into newly allocated values. */
3616 value_from_ulongest (struct type
*type
, ULONGEST num
)
3618 struct value
*val
= allocate_value (type
);
3620 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3626 /* Create a value representing a pointer of type TYPE to the address
3630 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3632 struct value
*val
= allocate_value (type
);
3634 store_typed_address (value_contents_raw (val
),
3635 check_typedef (type
), addr
);
3640 /* Create a value of type TYPE whose contents come from VALADDR, if it
3641 is non-null, and whose memory address (in the inferior) is
3642 ADDRESS. The type of the created value may differ from the passed
3643 type TYPE. Make sure to retrieve values new type after this call.
3644 Note that TYPE is not passed through resolve_dynamic_type; this is
3645 a special API intended for use only by Ada. */
3648 value_from_contents_and_address_unresolved (struct type
*type
,
3649 const gdb_byte
*valaddr
,
3654 if (valaddr
== NULL
)
3655 v
= allocate_value_lazy (type
);
3657 v
= value_from_contents (type
, valaddr
);
3658 set_value_address (v
, address
);
3659 VALUE_LVAL (v
) = lval_memory
;
3663 /* Create a value of type TYPE whose contents come from VALADDR, if it
3664 is non-null, and whose memory address (in the inferior) is
3665 ADDRESS. The type of the created value may differ from the passed
3666 type TYPE. Make sure to retrieve values new type after this call. */
3669 value_from_contents_and_address (struct type
*type
,
3670 const gdb_byte
*valaddr
,
3673 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3674 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3677 if (valaddr
== NULL
)
3678 v
= allocate_value_lazy (resolved_type
);
3680 v
= value_from_contents (resolved_type
, valaddr
);
3681 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3682 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3683 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3684 set_value_address (v
, address
);
3685 VALUE_LVAL (v
) = lval_memory
;
3689 /* Create a value of type TYPE holding the contents CONTENTS.
3690 The new value is `not_lval'. */
3693 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3695 struct value
*result
;
3697 result
= allocate_value (type
);
3698 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3703 value_from_double (struct type
*type
, DOUBLEST num
)
3705 struct value
*val
= allocate_value (type
);
3706 struct type
*base_type
= check_typedef (type
);
3707 enum type_code code
= TYPE_CODE (base_type
);
3709 if (code
== TYPE_CODE_FLT
)
3711 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3714 error (_("Unexpected type encountered for floating constant."));
3720 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3722 struct value
*val
= allocate_value (type
);
3724 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3728 /* Extract a value from the history file. Input will be of the form
3729 $digits or $$digits. See block comment above 'write_dollar_variable'
3733 value_from_history_ref (const char *h
, const char **endp
)
3745 /* Find length of numeral string. */
3746 for (; isdigit (h
[len
]); len
++)
3749 /* Make sure numeral string is not part of an identifier. */
3750 if (h
[len
] == '_' || isalpha (h
[len
]))
3753 /* Now collect the index value. */
3758 /* For some bizarre reason, "$$" is equivalent to "$$1",
3759 rather than to "$$0" as it ought to be! */
3767 index
= -strtol (&h
[2], &local_end
, 10);
3775 /* "$" is equivalent to "$0". */
3783 index
= strtol (&h
[1], &local_end
, 10);
3788 return access_value_history (index
);
3792 coerce_ref_if_computed (const struct value
*arg
)
3794 const struct lval_funcs
*funcs
;
3796 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3799 if (value_lval_const (arg
) != lval_computed
)
3802 funcs
= value_computed_funcs (arg
);
3803 if (funcs
->coerce_ref
== NULL
)
3806 return funcs
->coerce_ref (arg
);
3809 /* Look at value.h for description. */
3812 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3813 const struct type
*original_type
,
3814 const struct value
*original_value
)
3816 /* Re-adjust type. */
3817 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3819 /* Add embedding info. */
3820 set_value_enclosing_type (value
, enc_type
);
3821 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3823 /* We may be pointing to an object of some derived type. */
3824 return value_full_object (value
, NULL
, 0, 0, 0);
3828 coerce_ref (struct value
*arg
)
3830 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3831 struct value
*retval
;
3832 struct type
*enc_type
;
3834 retval
= coerce_ref_if_computed (arg
);
3838 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3841 enc_type
= check_typedef (value_enclosing_type (arg
));
3842 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3844 retval
= value_at_lazy (enc_type
,
3845 unpack_pointer (value_type (arg
),
3846 value_contents (arg
)));
3847 enc_type
= value_type (retval
);
3848 return readjust_indirect_value_type (retval
, enc_type
,
3849 value_type_arg_tmp
, arg
);
3853 coerce_array (struct value
*arg
)
3857 arg
= coerce_ref (arg
);
3858 type
= check_typedef (value_type (arg
));
3860 switch (TYPE_CODE (type
))
3862 case TYPE_CODE_ARRAY
:
3863 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3864 arg
= value_coerce_array (arg
);
3866 case TYPE_CODE_FUNC
:
3867 arg
= value_coerce_function (arg
);
3874 /* Return the return value convention that will be used for the
3877 enum return_value_convention
3878 struct_return_convention (struct gdbarch
*gdbarch
,
3879 struct value
*function
, struct type
*value_type
)
3881 enum type_code code
= TYPE_CODE (value_type
);
3883 if (code
== TYPE_CODE_ERROR
)
3884 error (_("Function return type unknown."));
3886 /* Probe the architecture for the return-value convention. */
3887 return gdbarch_return_value (gdbarch
, function
, value_type
,
3891 /* Return true if the function returning the specified type is using
3892 the convention of returning structures in memory (passing in the
3893 address as a hidden first parameter). */
3896 using_struct_return (struct gdbarch
*gdbarch
,
3897 struct value
*function
, struct type
*value_type
)
3899 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3900 /* A void return value is never in memory. See also corresponding
3901 code in "print_return_value". */
3904 return (struct_return_convention (gdbarch
, function
, value_type
)
3905 != RETURN_VALUE_REGISTER_CONVENTION
);
3908 /* Set the initialized field in a value struct. */
3911 set_value_initialized (struct value
*val
, int status
)
3913 val
->initialized
= status
;
3916 /* Return the initialized field in a value struct. */
3919 value_initialized (const struct value
*val
)
3921 return val
->initialized
;
3924 /* Load the actual content of a lazy value. Fetch the data from the
3925 user's process and clear the lazy flag to indicate that the data in
3926 the buffer is valid.
3928 If the value is zero-length, we avoid calling read_memory, which
3929 would abort. We mark the value as fetched anyway -- all 0 bytes of
3933 value_fetch_lazy (struct value
*val
)
3935 gdb_assert (value_lazy (val
));
3936 allocate_value_contents (val
);
3937 /* A value is either lazy, or fully fetched. The
3938 availability/validity is only established as we try to fetch a
3940 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3941 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3942 if (value_bitsize (val
))
3944 /* To read a lazy bitfield, read the entire enclosing value. This
3945 prevents reading the same block of (possibly volatile) memory once
3946 per bitfield. It would be even better to read only the containing
3947 word, but we have no way to record that just specific bits of a
3948 value have been fetched. */
3949 struct type
*type
= check_typedef (value_type (val
));
3950 struct value
*parent
= value_parent (val
);
3952 if (value_lazy (parent
))
3953 value_fetch_lazy (parent
);
3955 unpack_value_bitfield (val
,
3956 value_bitpos (val
), value_bitsize (val
),
3957 value_contents_for_printing (parent
),
3958 value_offset (val
), parent
);
3960 else if (VALUE_LVAL (val
) == lval_memory
)
3962 CORE_ADDR addr
= value_address (val
);
3963 struct type
*type
= check_typedef (value_enclosing_type (val
));
3965 if (TYPE_LENGTH (type
))
3966 read_value_memory (val
, 0, value_stack (val
),
3967 addr
, value_contents_all_raw (val
),
3968 type_length_units (type
));
3970 else if (VALUE_LVAL (val
) == lval_register
)
3972 struct frame_info
*frame
;
3974 struct type
*type
= check_typedef (value_type (val
));
3975 struct value
*new_val
= val
, *mark
= value_mark ();
3977 /* Offsets are not supported here; lazy register values must
3978 refer to the entire register. */
3979 gdb_assert (value_offset (val
) == 0);
3981 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3983 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3985 frame
= frame_find_by_id (frame_id
);
3986 regnum
= VALUE_REGNUM (new_val
);
3988 gdb_assert (frame
!= NULL
);
3990 /* Convertible register routines are used for multi-register
3991 values and for interpretation in different types
3992 (e.g. float or int from a double register). Lazy
3993 register values should have the register's natural type,
3994 so they do not apply. */
3995 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3998 new_val
= get_frame_register_value (frame
, regnum
);
4000 /* If we get another lazy lval_register value, it means the
4001 register is found by reading it from the next frame.
4002 get_frame_register_value should never return a value with
4003 the frame id pointing to FRAME. If it does, it means we
4004 either have two consecutive frames with the same frame id
4005 in the frame chain, or some code is trying to unwind
4006 behind get_prev_frame's back (e.g., a frame unwind
4007 sniffer trying to unwind), bypassing its validations. In
4008 any case, it should always be an internal error to end up
4009 in this situation. */
4010 if (VALUE_LVAL (new_val
) == lval_register
4011 && value_lazy (new_val
)
4012 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
4013 internal_error (__FILE__
, __LINE__
,
4014 _("infinite loop while fetching a register"));
4017 /* If it's still lazy (for instance, a saved register on the
4018 stack), fetch it. */
4019 if (value_lazy (new_val
))
4020 value_fetch_lazy (new_val
);
4022 /* Copy the contents and the unavailability/optimized-out
4023 meta-data from NEW_VAL to VAL. */
4024 set_value_lazy (val
, 0);
4025 value_contents_copy (val
, value_embedded_offset (val
),
4026 new_val
, value_embedded_offset (new_val
),
4027 type_length_units (type
));
4031 struct gdbarch
*gdbarch
;
4032 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4033 regnum
= VALUE_REGNUM (val
);
4034 gdbarch
= get_frame_arch (frame
);
4036 fprintf_unfiltered (gdb_stdlog
,
4037 "{ value_fetch_lazy "
4038 "(frame=%d,regnum=%d(%s),...) ",
4039 frame_relative_level (frame
), regnum
,
4040 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4042 fprintf_unfiltered (gdb_stdlog
, "->");
4043 if (value_optimized_out (new_val
))
4045 fprintf_unfiltered (gdb_stdlog
, " ");
4046 val_print_optimized_out (new_val
, gdb_stdlog
);
4051 const gdb_byte
*buf
= value_contents (new_val
);
4053 if (VALUE_LVAL (new_val
) == lval_register
)
4054 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4055 VALUE_REGNUM (new_val
));
4056 else if (VALUE_LVAL (new_val
) == lval_memory
)
4057 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4059 value_address (new_val
)));
4061 fprintf_unfiltered (gdb_stdlog
, " computed");
4063 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4064 fprintf_unfiltered (gdb_stdlog
, "[");
4065 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4066 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4067 fprintf_unfiltered (gdb_stdlog
, "]");
4070 fprintf_unfiltered (gdb_stdlog
, " }\n");
4073 /* Dispose of the intermediate values. This prevents
4074 watchpoints from trying to watch the saved frame pointer. */
4075 value_free_to_mark (mark
);
4077 else if (VALUE_LVAL (val
) == lval_computed
4078 && value_computed_funcs (val
)->read
!= NULL
)
4079 value_computed_funcs (val
)->read (val
);
4081 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4083 set_value_lazy (val
, 0);
4086 /* Implementation of the convenience function $_isvoid. */
4088 static struct value
*
4089 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4090 const struct language_defn
*language
,
4091 void *cookie
, int argc
, struct value
**argv
)
4096 error (_("You must provide one argument for $_isvoid."));
4098 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4100 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4104 _initialize_values (void)
4106 add_cmd ("convenience", no_class
, show_convenience
, _("\
4107 Debugger convenience (\"$foo\") variables and functions.\n\
4108 Convenience variables are created when you assign them values;\n\
4109 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4111 A few convenience variables are given values automatically:\n\
4112 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4113 \"$__\" holds the contents of the last address examined with \"x\"."
4116 Convenience functions are defined via the Python API."
4119 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4121 add_cmd ("values", no_set_class
, show_values
, _("\
4122 Elements of value history around item number IDX (or last ten)."),
4125 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4126 Initialize a convenience variable if necessary.\n\
4127 init-if-undefined VARIABLE = EXPRESSION\n\
4128 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4129 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4130 VARIABLE is already initialized."));
4132 add_prefix_cmd ("function", no_class
, function_command
, _("\
4133 Placeholder command for showing help on convenience functions."),
4134 &functionlist
, "function ", 0, &cmdlist
);
4136 add_internal_function ("_isvoid", _("\
4137 Check whether an expression is void.\n\
4138 Usage: $_isvoid (expression)\n\
4139 Return 1 if the expression is void, zero otherwise."),
4140 isvoid_internal_fn
, NULL
);
4142 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4143 class_support
, &max_value_size
, _("\
4144 Set maximum sized value gdb will load from the inferior."), _("\
4145 Show maximum sized value gdb will load from the inferior."), _("\
4146 Use this to control the maximum size, in bytes, of a value that gdb\n\
4147 will load from the inferior. Setting this value to 'unlimited'\n\
4148 disables checking.\n\
4149 Setting this does not invalidate already allocated values, it only\n\
4150 prevents future values, larger than this size, from being allocated."),
4152 show_max_value_size
,
4153 &setlist
, &showlist
);