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"
45 /* Prototypes for exported functions. */
47 void _initialize_values (void);
49 /* Definition of a user function. */
50 struct internal_function
52 /* The name of the function. It is a bit odd to have this in the
53 function itself -- the user might use a differently-named
54 convenience variable to hold the function. */
58 internal_function_fn handler
;
60 /* User data for the handler. */
64 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
68 /* Lowest offset in the range. */
71 /* Length of the range. */
75 typedef struct range range_s
;
79 /* Returns true if the ranges defined by [offset1, offset1+len1) and
80 [offset2, offset2+len2) overlap. */
83 ranges_overlap (LONGEST offset1
, LONGEST len1
,
84 LONGEST offset2
, LONGEST len2
)
88 l
= std::max (offset1
, offset2
);
89 h
= std::min (offset1
+ len1
, offset2
+ len2
);
93 /* Returns true if the first argument is strictly less than the
94 second, useful for VEC_lower_bound. We keep ranges sorted by
95 offset and coalesce overlapping and contiguous ranges, so this just
96 compares the starting offset. */
99 range_lessthan (const range_s
*r1
, const range_s
*r2
)
101 return r1
->offset
< r2
->offset
;
104 /* Returns true if RANGES contains any range that overlaps [OFFSET,
108 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
113 what
.offset
= offset
;
114 what
.length
= length
;
116 /* We keep ranges sorted by offset and coalesce overlapping and
117 contiguous ranges, so to check if a range list contains a given
118 range, we can do a binary search for the position the given range
119 would be inserted if we only considered the starting OFFSET of
120 ranges. We call that position I. Since we also have LENGTH to
121 care for (this is a range afterall), we need to check if the
122 _previous_ range overlaps the I range. E.g.,
126 |---| |---| |------| ... |--|
131 In the case above, the binary search would return `I=1', meaning,
132 this OFFSET should be inserted at position 1, and the current
133 position 1 should be pushed further (and before 2). But, `0'
136 Then we need to check if the I range overlaps the I range itself.
141 |---| |---| |-------| ... |--|
147 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
151 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
153 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
157 if (i
< VEC_length (range_s
, ranges
))
159 struct range
*r
= VEC_index (range_s
, ranges
, i
);
161 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
168 static struct cmd_list_element
*functionlist
;
170 /* Note that the fields in this structure are arranged to save a bit
175 /* Type of value; either not an lval, or one of the various
176 different possible kinds of lval. */
179 /* Is it modifiable? Only relevant if lval != not_lval. */
180 unsigned int modifiable
: 1;
182 /* If zero, contents of this value are in the contents field. If
183 nonzero, contents are in inferior. If the lval field is lval_memory,
184 the contents are in inferior memory at location.address plus offset.
185 The lval field may also be lval_register.
187 WARNING: This field is used by the code which handles watchpoints
188 (see breakpoint.c) to decide whether a particular value can be
189 watched by hardware watchpoints. If the lazy flag is set for
190 some member of a value chain, it is assumed that this member of
191 the chain doesn't need to be watched as part of watching the
192 value itself. This is how GDB avoids watching the entire struct
193 or array when the user wants to watch a single struct member or
194 array element. If you ever change the way lazy flag is set and
195 reset, be sure to consider this use as well! */
196 unsigned int lazy
: 1;
198 /* If value is a variable, is it initialized or not. */
199 unsigned int initialized
: 1;
201 /* If value is from the stack. If this is set, read_stack will be
202 used instead of read_memory to enable extra caching. */
203 unsigned int stack
: 1;
205 /* If the value has been released. */
206 unsigned int released
: 1;
208 /* Register number if the value is from a register. */
211 /* Location of value (if lval). */
214 /* If lval == lval_memory, this is the address in the inferior.
215 If lval == lval_register, this is the byte offset into the
216 registers structure. */
219 /* Pointer to internal variable. */
220 struct internalvar
*internalvar
;
222 /* Pointer to xmethod worker. */
223 struct xmethod_worker
*xm_worker
;
225 /* If lval == lval_computed, this is a set of function pointers
226 to use to access and describe the value, and a closure pointer
230 /* Functions to call. */
231 const struct lval_funcs
*funcs
;
233 /* Closure for those functions to use. */
238 /* Describes offset of a value within lval of a structure in target
239 addressable memory units. If lval == lval_memory, this is an offset to
240 the address. If lval == lval_register, this is a further offset from
241 location.address within the registers structure. Note also the member
242 embedded_offset below. */
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value
*parent
;
265 /* Frame register value is relative to. This will be described in
266 the lval enum above as "lval_register". */
267 struct frame_id frame_id
;
269 /* Type of the value. */
272 /* If a value represents a C++ object, then the `type' field gives
273 the object's compile-time type. If the object actually belongs
274 to some class derived from `type', perhaps with other base
275 classes and additional members, then `type' is just a subobject
276 of the real thing, and the full object is probably larger than
277 `type' would suggest.
279 If `type' is a dynamic class (i.e. one with a vtable), then GDB
280 can actually determine the object's run-time type by looking at
281 the run-time type information in the vtable. When this
282 information is available, we may elect to read in the entire
283 object, for several reasons:
285 - When printing the value, the user would probably rather see the
286 full object, not just the limited portion apparent from the
289 - If `type' has virtual base classes, then even printing `type'
290 alone may require reaching outside the `type' portion of the
291 object to wherever the virtual base class has been stored.
293 When we store the entire object, `enclosing_type' is the run-time
294 type -- the complete object -- and `embedded_offset' is the
295 offset of `type' within that larger type, in target addressable memory
296 units. The value_contents() macro takes `embedded_offset' into account,
297 so most GDB code continues to see the `type' portion of the value, just
298 as the inferior would.
300 If `type' is a pointer to an object, then `enclosing_type' is a
301 pointer to the object's run-time type, and `pointed_to_offset' is
302 the offset in target addressable memory units from the full object
303 to the pointed-to object -- that is, the value `embedded_offset' would
304 have if we followed the pointer and fetched the complete object.
305 (I don't really see the point. Why not just determine the
306 run-time type when you indirect, and avoid the special case? The
307 contents don't matter until you indirect anyway.)
309 If we're not doing anything fancy, `enclosing_type' is equal to
310 `type', and `embedded_offset' is zero, so everything works
312 struct type
*enclosing_type
;
313 LONGEST embedded_offset
;
314 LONGEST pointed_to_offset
;
316 /* Values are stored in a chain, so that they can be deleted easily
317 over calls to the inferior. Values assigned to internal
318 variables, put into the value history or exposed to Python are
319 taken off this list. */
322 /* Actual contents of the value. Target byte-order. NULL or not
323 valid if lazy is nonzero. */
326 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
327 rather than available, since the common and default case is for a
328 value to be available. This is filled in at value read time.
329 The unavailable ranges are tracked in bits. Note that a contents
330 bit that has been optimized out doesn't really exist in the
331 program, so it can't be marked unavailable either. */
332 VEC(range_s
) *unavailable
;
334 /* Likewise, but for optimized out contents (a chunk of the value of
335 a variable that does not actually exist in the program). If LVAL
336 is lval_register, this is a register ($pc, $sp, etc., never a
337 program variable) that has not been saved in the frame. Not
338 saved registers and optimized-out program variables values are
339 treated pretty much the same, except not-saved registers have a
340 different string representation and related error strings. */
341 VEC(range_s
) *optimized_out
;
347 get_value_arch (const struct value
*value
)
349 return get_type_arch (value_type (value
));
353 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
355 gdb_assert (!value
->lazy
);
357 return !ranges_contain (value
->unavailable
, offset
, length
);
361 value_bytes_available (const struct value
*value
,
362 LONGEST offset
, LONGEST length
)
364 return value_bits_available (value
,
365 offset
* TARGET_CHAR_BIT
,
366 length
* TARGET_CHAR_BIT
);
370 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
372 gdb_assert (!value
->lazy
);
374 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
378 value_entirely_available (struct value
*value
)
380 /* We can only tell whether the whole value is available when we try
383 value_fetch_lazy (value
);
385 if (VEC_empty (range_s
, value
->unavailable
))
390 /* Returns true if VALUE is entirely covered by RANGES. If the value
391 is lazy, it'll be read now. Note that RANGE is a pointer to
392 pointer because reading the value might change *RANGE. */
395 value_entirely_covered_by_range_vector (struct value
*value
,
396 VEC(range_s
) **ranges
)
398 /* We can only tell whether the whole value is optimized out /
399 unavailable when we try to read it. */
401 value_fetch_lazy (value
);
403 if (VEC_length (range_s
, *ranges
) == 1)
405 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
408 && t
->length
== (TARGET_CHAR_BIT
409 * TYPE_LENGTH (value_enclosing_type (value
))))
417 value_entirely_unavailable (struct value
*value
)
419 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
423 value_entirely_optimized_out (struct value
*value
)
425 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
428 /* Insert into the vector pointed to by VECTORP the bit range starting of
429 OFFSET bits, and extending for the next LENGTH bits. */
432 insert_into_bit_range_vector (VEC(range_s
) **vectorp
,
433 LONGEST offset
, LONGEST length
)
438 /* Insert the range sorted. If there's overlap or the new range
439 would be contiguous with an existing range, merge. */
441 newr
.offset
= offset
;
442 newr
.length
= length
;
444 /* Do a binary search for the position the given range would be
445 inserted if we only considered the starting OFFSET of ranges.
446 Call that position I. Since we also have LENGTH to care for
447 (this is a range afterall), we need to check if the _previous_
448 range overlaps the I range. E.g., calling R the new range:
450 #1 - overlaps with previous
454 |---| |---| |------| ... |--|
459 In the case #1 above, the binary search would return `I=1',
460 meaning, this OFFSET should be inserted at position 1, and the
461 current position 1 should be pushed further (and become 2). But,
462 note that `0' overlaps with R, so we want to merge them.
464 A similar consideration needs to be taken if the new range would
465 be contiguous with the previous range:
467 #2 - contiguous with previous
471 |--| |---| |------| ... |--|
476 If there's no overlap with the previous range, as in:
478 #3 - not overlapping and not contiguous
482 |--| |---| |------| ... |--|
489 #4 - R is the range with lowest offset
493 |--| |---| |------| ... |--|
498 ... we just push the new range to I.
500 All the 4 cases above need to consider that the new range may
501 also overlap several of the ranges that follow, or that R may be
502 contiguous with the following range, and merge. E.g.,
504 #5 - overlapping following ranges
507 |------------------------|
508 |--| |---| |------| ... |--|
517 |--| |---| |------| ... |--|
524 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
527 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
529 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
532 ULONGEST l
= std::min (bef
->offset
, offset
);
533 ULONGEST h
= std::max (bef
->offset
+ bef
->length
, offset
+ length
);
539 else if (offset
== bef
->offset
+ bef
->length
)
542 bef
->length
+= length
;
548 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
554 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
557 /* Check whether the ranges following the one we've just added or
558 touched can be folded in (#5 above). */
559 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
566 /* Get the range we just touched. */
567 t
= VEC_index (range_s
, *vectorp
, i
);
571 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
572 if (r
->offset
<= t
->offset
+ t
->length
)
576 l
= std::min (t
->offset
, r
->offset
);
577 h
= std::max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
586 /* If we couldn't merge this one, we won't be able to
587 merge following ones either, since the ranges are
588 always sorted by OFFSET. */
593 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
598 mark_value_bits_unavailable (struct value
*value
,
599 LONGEST offset
, LONGEST length
)
601 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
605 mark_value_bytes_unavailable (struct value
*value
,
606 LONGEST offset
, LONGEST length
)
608 mark_value_bits_unavailable (value
,
609 offset
* TARGET_CHAR_BIT
,
610 length
* TARGET_CHAR_BIT
);
613 /* Find the first range in RANGES that overlaps the range defined by
614 OFFSET and LENGTH, starting at element POS in the RANGES vector,
615 Returns the index into RANGES where such overlapping range was
616 found, or -1 if none was found. */
619 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
620 LONGEST offset
, LONGEST length
)
625 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
626 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
632 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
633 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
636 It must always be the case that:
637 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
639 It is assumed that memory can be accessed from:
640 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
642 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
643 / TARGET_CHAR_BIT) */
645 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
646 const gdb_byte
*ptr2
, size_t offset2_bits
,
649 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
650 == offset2_bits
% TARGET_CHAR_BIT
);
652 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
655 gdb_byte mask
, b1
, b2
;
657 /* The offset from the base pointers PTR1 and PTR2 is not a complete
658 number of bytes. A number of bits up to either the next exact
659 byte boundary, or LENGTH_BITS (which ever is sooner) will be
661 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
662 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
663 mask
= (1 << bits
) - 1;
665 if (length_bits
< bits
)
667 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
671 /* Now load the two bytes and mask off the bits we care about. */
672 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
673 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
678 /* Now update the length and offsets to take account of the bits
679 we've just compared. */
681 offset1_bits
+= bits
;
682 offset2_bits
+= bits
;
685 if (length_bits
% TARGET_CHAR_BIT
!= 0)
689 gdb_byte mask
, b1
, b2
;
691 /* The length is not an exact number of bytes. After the previous
692 IF.. block then the offsets are byte aligned, or the
693 length is zero (in which case this code is not reached). Compare
694 a number of bits at the end of the region, starting from an exact
696 bits
= length_bits
% TARGET_CHAR_BIT
;
697 o1
= offset1_bits
+ length_bits
- bits
;
698 o2
= offset2_bits
+ length_bits
- bits
;
700 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
701 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
703 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
704 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
706 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
707 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
717 /* We've now taken care of any stray "bits" at the start, or end of
718 the region to compare, the remainder can be covered with a simple
720 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
721 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
722 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
724 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
725 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
726 length_bits
/ TARGET_CHAR_BIT
);
729 /* Length is zero, regions match. */
733 /* Helper struct for find_first_range_overlap_and_match and
734 value_contents_bits_eq. Keep track of which slot of a given ranges
735 vector have we last looked at. */
737 struct ranges_and_idx
740 VEC(range_s
) *ranges
;
742 /* The range we've last found in RANGES. Given ranges are sorted,
743 we can start the next lookup here. */
747 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
748 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
749 ranges starting at OFFSET2 bits. Return true if the ranges match
750 and fill in *L and *H with the overlapping window relative to
751 (both) OFFSET1 or OFFSET2. */
754 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
755 struct ranges_and_idx
*rp2
,
756 LONGEST offset1
, LONGEST offset2
,
757 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
759 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
761 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
764 if (rp1
->idx
== -1 && rp2
->idx
== -1)
770 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
778 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
779 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
781 /* Get the unavailable windows intersected by the incoming
782 ranges. The first and last ranges that overlap the argument
783 range may be wider than said incoming arguments ranges. */
784 l1
= std::max (offset1
, r1
->offset
);
785 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
787 l2
= std::max (offset2
, r2
->offset
);
788 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
790 /* Make them relative to the respective start offsets, so we can
791 compare them for equality. */
798 /* Different ranges, no match. */
799 if (l1
!= l2
|| h1
!= h2
)
808 /* Helper function for value_contents_eq. The only difference is that
809 this function is bit rather than byte based.
811 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
812 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
813 Return true if the available bits match. */
816 value_contents_bits_eq (const struct value
*val1
, int offset1
,
817 const struct value
*val2
, int offset2
,
820 /* Each array element corresponds to a ranges source (unavailable,
821 optimized out). '1' is for VAL1, '2' for VAL2. */
822 struct ranges_and_idx rp1
[2], rp2
[2];
824 /* See function description in value.h. */
825 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
827 /* We shouldn't be trying to compare past the end of the values. */
828 gdb_assert (offset1
+ length
829 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
830 gdb_assert (offset2
+ length
831 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
833 memset (&rp1
, 0, sizeof (rp1
));
834 memset (&rp2
, 0, sizeof (rp2
));
835 rp1
[0].ranges
= val1
->unavailable
;
836 rp2
[0].ranges
= val2
->unavailable
;
837 rp1
[1].ranges
= val1
->optimized_out
;
838 rp2
[1].ranges
= val2
->optimized_out
;
842 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
845 for (i
= 0; i
< 2; i
++)
847 ULONGEST l_tmp
, h_tmp
;
849 /* The contents only match equal if the invalid/unavailable
850 contents ranges match as well. */
851 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
852 offset1
, offset2
, length
,
856 /* We're interested in the lowest/first range found. */
857 if (i
== 0 || l_tmp
< l
)
864 /* Compare the available/valid contents. */
865 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
866 val2
->contents
, offset2
, l
) != 0)
878 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
879 const struct value
*val2
, LONGEST offset2
,
882 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
883 val2
, offset2
* TARGET_CHAR_BIT
,
884 length
* TARGET_CHAR_BIT
);
887 /* Prototypes for local functions. */
889 static void show_values (char *, int);
891 static void show_convenience (char *, int);
894 /* The value-history records all the values printed
895 by print commands during this session. Each chunk
896 records 60 consecutive values. The first chunk on
897 the chain records the most recent values.
898 The total number of values is in value_history_count. */
900 #define VALUE_HISTORY_CHUNK 60
902 struct value_history_chunk
904 struct value_history_chunk
*next
;
905 struct value
*values
[VALUE_HISTORY_CHUNK
];
908 /* Chain of chunks now in use. */
910 static struct value_history_chunk
*value_history_chain
;
912 static int value_history_count
; /* Abs number of last entry stored. */
915 /* List of all value objects currently allocated
916 (except for those released by calls to release_value)
917 This is so they can be freed after each command. */
919 static struct value
*all_values
;
921 /* Allocate a lazy value for type TYPE. Its actual content is
922 "lazily" allocated too: the content field of the return value is
923 NULL; it will be allocated when it is fetched from the target. */
926 allocate_value_lazy (struct type
*type
)
930 /* Call check_typedef on our type to make sure that, if TYPE
931 is a TYPE_CODE_TYPEDEF, its length is set to the length
932 of the target type instead of zero. However, we do not
933 replace the typedef type by the target type, because we want
934 to keep the typedef in order to be able to set the VAL's type
935 description correctly. */
936 check_typedef (type
);
938 val
= XCNEW (struct value
);
939 val
->contents
= NULL
;
940 val
->next
= all_values
;
943 val
->enclosing_type
= type
;
944 VALUE_LVAL (val
) = not_lval
;
945 val
->location
.address
= 0;
946 VALUE_FRAME_ID (val
) = null_frame_id
;
950 VALUE_REGNUM (val
) = -1;
952 val
->embedded_offset
= 0;
953 val
->pointed_to_offset
= 0;
955 val
->initialized
= 1; /* Default to initialized. */
957 /* Values start out on the all_values chain. */
958 val
->reference_count
= 1;
963 /* The maximum size, in bytes, that GDB will try to allocate for a value.
964 The initial value of 64k was not selected for any specific reason, it is
965 just a reasonable starting point. */
967 static int max_value_size
= 65536; /* 64k bytes */
969 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
970 LONGEST, otherwise GDB will not be able to parse integer values from the
971 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
972 be unable to parse "set max-value-size 2".
974 As we want a consistent GDB experience across hosts with different sizes
975 of LONGEST, this arbitrary minimum value was selected, so long as this
976 is bigger than LONGEST on all GDB supported hosts we're fine. */
978 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
979 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
981 /* Implement the "set max-value-size" command. */
984 set_max_value_size (char *args
, int from_tty
,
985 struct cmd_list_element
*c
)
987 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
989 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
991 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
992 error (_("max-value-size set too low, increasing to %d bytes"),
997 /* Implement the "show max-value-size" command. */
1000 show_max_value_size (struct ui_file
*file
, int from_tty
,
1001 struct cmd_list_element
*c
, const char *value
)
1003 if (max_value_size
== -1)
1004 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
1006 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
1010 /* Called before we attempt to allocate or reallocate a buffer for the
1011 contents of a value. TYPE is the type of the value for which we are
1012 allocating the buffer. If the buffer is too large (based on the user
1013 controllable setting) then throw an error. If this function returns
1014 then we should attempt to allocate the buffer. */
1017 check_type_length_before_alloc (const struct type
*type
)
1019 unsigned int length
= TYPE_LENGTH (type
);
1021 if (max_value_size
> -1 && length
> max_value_size
)
1023 if (TYPE_NAME (type
) != NULL
)
1024 error (_("value of type `%s' requires %u bytes, which is more "
1025 "than max-value-size"), TYPE_NAME (type
), length
);
1027 error (_("value requires %u bytes, which is more than "
1028 "max-value-size"), length
);
1032 /* Allocate the contents of VAL if it has not been allocated yet. */
1035 allocate_value_contents (struct value
*val
)
1039 check_type_length_before_alloc (val
->enclosing_type
);
1041 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1045 /* Allocate a value and its contents for type TYPE. */
1048 allocate_value (struct type
*type
)
1050 struct value
*val
= allocate_value_lazy (type
);
1052 allocate_value_contents (val
);
1057 /* Allocate a value that has the correct length
1058 for COUNT repetitions of type TYPE. */
1061 allocate_repeat_value (struct type
*type
, int count
)
1063 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1064 /* FIXME-type-allocation: need a way to free this type when we are
1066 struct type
*array_type
1067 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1069 return allocate_value (array_type
);
1073 allocate_computed_value (struct type
*type
,
1074 const struct lval_funcs
*funcs
,
1077 struct value
*v
= allocate_value_lazy (type
);
1079 VALUE_LVAL (v
) = lval_computed
;
1080 v
->location
.computed
.funcs
= funcs
;
1081 v
->location
.computed
.closure
= closure
;
1086 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1089 allocate_optimized_out_value (struct type
*type
)
1091 struct value
*retval
= allocate_value_lazy (type
);
1093 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1094 set_value_lazy (retval
, 0);
1098 /* Accessor methods. */
1101 value_next (const struct value
*value
)
1107 value_type (const struct value
*value
)
1112 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1118 value_offset (const struct value
*value
)
1120 return value
->offset
;
1123 set_value_offset (struct value
*value
, LONGEST offset
)
1125 value
->offset
= offset
;
1129 value_bitpos (const struct value
*value
)
1131 return value
->bitpos
;
1134 set_value_bitpos (struct value
*value
, LONGEST bit
)
1136 value
->bitpos
= bit
;
1140 value_bitsize (const struct value
*value
)
1142 return value
->bitsize
;
1145 set_value_bitsize (struct value
*value
, LONGEST bit
)
1147 value
->bitsize
= bit
;
1151 value_parent (const struct value
*value
)
1153 return value
->parent
;
1159 set_value_parent (struct value
*value
, struct value
*parent
)
1161 struct value
*old
= value
->parent
;
1163 value
->parent
= parent
;
1165 value_incref (parent
);
1170 value_contents_raw (struct value
*value
)
1172 struct gdbarch
*arch
= get_value_arch (value
);
1173 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1175 allocate_value_contents (value
);
1176 return value
->contents
+ value
->embedded_offset
* unit_size
;
1180 value_contents_all_raw (struct value
*value
)
1182 allocate_value_contents (value
);
1183 return value
->contents
;
1187 value_enclosing_type (const struct value
*value
)
1189 return value
->enclosing_type
;
1192 /* Look at value.h for description. */
1195 value_actual_type (struct value
*value
, int resolve_simple_types
,
1196 int *real_type_found
)
1198 struct value_print_options opts
;
1199 struct type
*result
;
1201 get_user_print_options (&opts
);
1203 if (real_type_found
)
1204 *real_type_found
= 0;
1205 result
= value_type (value
);
1206 if (opts
.objectprint
)
1208 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1209 fetch its rtti type. */
1210 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1211 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1212 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1214 && !value_optimized_out (value
))
1216 struct type
*real_type
;
1218 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1221 if (real_type_found
)
1222 *real_type_found
= 1;
1226 else if (resolve_simple_types
)
1228 if (real_type_found
)
1229 *real_type_found
= 1;
1230 result
= value_enclosing_type (value
);
1238 error_value_optimized_out (void)
1240 error (_("value has been optimized out"));
1244 require_not_optimized_out (const struct value
*value
)
1246 if (!VEC_empty (range_s
, value
->optimized_out
))
1248 if (value
->lval
== lval_register
)
1249 error (_("register has not been saved in frame"));
1251 error_value_optimized_out ();
1256 require_available (const struct value
*value
)
1258 if (!VEC_empty (range_s
, value
->unavailable
))
1259 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1263 value_contents_for_printing (struct value
*value
)
1266 value_fetch_lazy (value
);
1267 return value
->contents
;
1271 value_contents_for_printing_const (const struct value
*value
)
1273 gdb_assert (!value
->lazy
);
1274 return value
->contents
;
1278 value_contents_all (struct value
*value
)
1280 const gdb_byte
*result
= value_contents_for_printing (value
);
1281 require_not_optimized_out (value
);
1282 require_available (value
);
1286 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1287 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1290 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1291 VEC (range_s
) *src_range
, int src_bit_offset
,
1297 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1301 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1302 h
= std::min (r
->offset
+ r
->length
,
1303 (LONGEST
) src_bit_offset
+ bit_length
);
1306 insert_into_bit_range_vector (dst_range
,
1307 dst_bit_offset
+ (l
- src_bit_offset
),
1312 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1313 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1316 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1317 const struct value
*src
, int src_bit_offset
,
1320 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1321 src
->unavailable
, src_bit_offset
,
1323 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1324 src
->optimized_out
, src_bit_offset
,
1328 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1329 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1330 contents, starting at DST_OFFSET. If unavailable contents are
1331 being copied from SRC, the corresponding DST contents are marked
1332 unavailable accordingly. Neither DST nor SRC may be lazy
1335 It is assumed the contents of DST in the [DST_OFFSET,
1336 DST_OFFSET+LENGTH) range are wholly available. */
1339 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1340 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1342 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1343 struct gdbarch
*arch
= get_value_arch (src
);
1344 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1346 /* A lazy DST would make that this copy operation useless, since as
1347 soon as DST's contents were un-lazied (by a later value_contents
1348 call, say), the contents would be overwritten. A lazy SRC would
1349 mean we'd be copying garbage. */
1350 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1352 /* The overwritten DST range gets unavailability ORed in, not
1353 replaced. Make sure to remember to implement replacing if it
1354 turns out actually necessary. */
1355 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1356 gdb_assert (!value_bits_any_optimized_out (dst
,
1357 TARGET_CHAR_BIT
* dst_offset
,
1358 TARGET_CHAR_BIT
* length
));
1360 /* Copy the data. */
1361 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1362 value_contents_all_raw (src
) + src_offset
* unit_size
,
1363 length
* unit_size
);
1365 /* Copy the meta-data, adjusted. */
1366 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1367 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1368 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1370 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1371 src
, src_bit_offset
,
1375 /* Copy LENGTH bytes of SRC value's (all) contents
1376 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1377 (all) contents, starting at DST_OFFSET. If unavailable contents
1378 are being copied from SRC, the corresponding DST contents are
1379 marked unavailable accordingly. DST must not be lazy. If SRC is
1380 lazy, it will be fetched now.
1382 It is assumed the contents of DST in the [DST_OFFSET,
1383 DST_OFFSET+LENGTH) range are wholly available. */
1386 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1387 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1390 value_fetch_lazy (src
);
1392 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1396 value_lazy (const struct value
*value
)
1402 set_value_lazy (struct value
*value
, int val
)
1408 value_stack (const struct value
*value
)
1410 return value
->stack
;
1414 set_value_stack (struct value
*value
, int val
)
1420 value_contents (struct value
*value
)
1422 const gdb_byte
*result
= value_contents_writeable (value
);
1423 require_not_optimized_out (value
);
1424 require_available (value
);
1429 value_contents_writeable (struct value
*value
)
1432 value_fetch_lazy (value
);
1433 return value_contents_raw (value
);
1437 value_optimized_out (struct value
*value
)
1439 /* We can only know if a value is optimized out once we have tried to
1441 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1445 value_fetch_lazy (value
);
1447 CATCH (ex
, RETURN_MASK_ERROR
)
1449 /* Fall back to checking value->optimized_out. */
1454 return !VEC_empty (range_s
, value
->optimized_out
);
1457 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1458 the following LENGTH bytes. */
1461 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1463 mark_value_bits_optimized_out (value
,
1464 offset
* TARGET_CHAR_BIT
,
1465 length
* TARGET_CHAR_BIT
);
1471 mark_value_bits_optimized_out (struct value
*value
,
1472 LONGEST offset
, LONGEST length
)
1474 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1478 value_bits_synthetic_pointer (const struct value
*value
,
1479 LONGEST offset
, LONGEST length
)
1481 if (value
->lval
!= lval_computed
1482 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1484 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1490 value_embedded_offset (const struct value
*value
)
1492 return value
->embedded_offset
;
1496 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1498 value
->embedded_offset
= val
;
1502 value_pointed_to_offset (const struct value
*value
)
1504 return value
->pointed_to_offset
;
1508 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1510 value
->pointed_to_offset
= val
;
1513 const struct lval_funcs
*
1514 value_computed_funcs (const struct value
*v
)
1516 gdb_assert (value_lval_const (v
) == lval_computed
);
1518 return v
->location
.computed
.funcs
;
1522 value_computed_closure (const struct value
*v
)
1524 gdb_assert (v
->lval
== lval_computed
);
1526 return v
->location
.computed
.closure
;
1530 deprecated_value_lval_hack (struct value
*value
)
1532 return &value
->lval
;
1536 value_lval_const (const struct value
*value
)
1542 value_address (const struct value
*value
)
1544 if (value
->lval
== lval_internalvar
1545 || value
->lval
== lval_internalvar_component
1546 || value
->lval
== lval_xcallable
)
1548 if (value
->parent
!= NULL
)
1549 return value_address (value
->parent
) + value
->offset
;
1550 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1552 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1553 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1556 return value
->location
.address
+ value
->offset
;
1560 value_raw_address (const struct value
*value
)
1562 if (value
->lval
== lval_internalvar
1563 || value
->lval
== lval_internalvar_component
1564 || value
->lval
== lval_xcallable
)
1566 return value
->location
.address
;
1570 set_value_address (struct value
*value
, CORE_ADDR addr
)
1572 gdb_assert (value
->lval
!= lval_internalvar
1573 && value
->lval
!= lval_internalvar_component
1574 && value
->lval
!= lval_xcallable
);
1575 value
->location
.address
= addr
;
1578 struct internalvar
**
1579 deprecated_value_internalvar_hack (struct value
*value
)
1581 return &value
->location
.internalvar
;
1585 deprecated_value_frame_id_hack (struct value
*value
)
1587 return &value
->frame_id
;
1591 deprecated_value_regnum_hack (struct value
*value
)
1593 return &value
->regnum
;
1597 deprecated_value_modifiable (const struct value
*value
)
1599 return value
->modifiable
;
1602 /* Return a mark in the value chain. All values allocated after the
1603 mark is obtained (except for those released) are subject to being freed
1604 if a subsequent value_free_to_mark is passed the mark. */
1611 /* Take a reference to VAL. VAL will not be deallocated until all
1612 references are released. */
1615 value_incref (struct value
*val
)
1617 val
->reference_count
++;
1620 /* Release a reference to VAL, which was acquired with value_incref.
1621 This function is also called to deallocate values from the value
1625 value_free (struct value
*val
)
1629 gdb_assert (val
->reference_count
> 0);
1630 val
->reference_count
--;
1631 if (val
->reference_count
> 0)
1634 /* If there's an associated parent value, drop our reference to
1636 if (val
->parent
!= NULL
)
1637 value_free (val
->parent
);
1639 if (VALUE_LVAL (val
) == lval_computed
)
1641 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1643 if (funcs
->free_closure
)
1644 funcs
->free_closure (val
);
1646 else if (VALUE_LVAL (val
) == lval_xcallable
)
1647 free_xmethod_worker (val
->location
.xm_worker
);
1649 xfree (val
->contents
);
1650 VEC_free (range_s
, val
->unavailable
);
1655 /* Free all values allocated since MARK was obtained by value_mark
1656 (except for those released). */
1658 value_free_to_mark (const struct value
*mark
)
1663 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1672 /* Free all the values that have been allocated (except for those released).
1673 Call after each command, successful or not.
1674 In practice this is called before each command, which is sufficient. */
1677 free_all_values (void)
1682 for (val
= all_values
; val
; val
= next
)
1692 /* Frees all the elements in a chain of values. */
1695 free_value_chain (struct value
*v
)
1701 next
= value_next (v
);
1706 /* Remove VAL from the chain all_values
1707 so it will not be freed automatically. */
1710 release_value (struct value
*val
)
1714 if (all_values
== val
)
1716 all_values
= val
->next
;
1722 for (v
= all_values
; v
; v
= v
->next
)
1726 v
->next
= val
->next
;
1734 /* If the value is not already released, release it.
1735 If the value is already released, increment its reference count.
1736 That is, this function ensures that the value is released from the
1737 value chain and that the caller owns a reference to it. */
1740 release_value_or_incref (struct value
*val
)
1745 release_value (val
);
1748 /* Release all values up to mark */
1750 value_release_to_mark (const struct value
*mark
)
1755 for (val
= next
= all_values
; next
; next
= next
->next
)
1757 if (next
->next
== mark
)
1759 all_values
= next
->next
;
1769 /* Return a copy of the value ARG.
1770 It contains the same contents, for same memory address,
1771 but it's a different block of storage. */
1774 value_copy (struct value
*arg
)
1776 struct type
*encl_type
= value_enclosing_type (arg
);
1779 if (value_lazy (arg
))
1780 val
= allocate_value_lazy (encl_type
);
1782 val
= allocate_value (encl_type
);
1783 val
->type
= arg
->type
;
1784 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1785 val
->location
= arg
->location
;
1786 val
->offset
= arg
->offset
;
1787 val
->bitpos
= arg
->bitpos
;
1788 val
->bitsize
= arg
->bitsize
;
1789 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1790 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1791 val
->lazy
= arg
->lazy
;
1792 val
->embedded_offset
= value_embedded_offset (arg
);
1793 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1794 val
->modifiable
= arg
->modifiable
;
1795 if (!value_lazy (val
))
1797 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1798 TYPE_LENGTH (value_enclosing_type (arg
)));
1801 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1802 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1803 set_value_parent (val
, arg
->parent
);
1804 if (VALUE_LVAL (val
) == lval_computed
)
1806 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1808 if (funcs
->copy_closure
)
1809 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1814 /* Return a "const" and/or "volatile" qualified version of the value V.
1815 If CNST is true, then the returned value will be qualified with
1817 if VOLTL is true, then the returned value will be qualified with
1821 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1823 struct type
*val_type
= value_type (v
);
1824 struct type
*enclosing_type
= value_enclosing_type (v
);
1825 struct value
*cv_val
= value_copy (v
);
1827 deprecated_set_value_type (cv_val
,
1828 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1829 set_value_enclosing_type (cv_val
,
1830 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1835 /* Return a version of ARG that is non-lvalue. */
1838 value_non_lval (struct value
*arg
)
1840 if (VALUE_LVAL (arg
) != not_lval
)
1842 struct type
*enc_type
= value_enclosing_type (arg
);
1843 struct value
*val
= allocate_value (enc_type
);
1845 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1846 TYPE_LENGTH (enc_type
));
1847 val
->type
= arg
->type
;
1848 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1849 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1855 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1858 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1860 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1862 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1863 v
->lval
= lval_memory
;
1864 v
->location
.address
= addr
;
1868 set_value_component_location (struct value
*component
,
1869 const struct value
*whole
)
1873 gdb_assert (whole
->lval
!= lval_xcallable
);
1875 if (whole
->lval
== lval_internalvar
)
1876 VALUE_LVAL (component
) = lval_internalvar_component
;
1878 VALUE_LVAL (component
) = whole
->lval
;
1880 component
->location
= whole
->location
;
1881 if (whole
->lval
== lval_computed
)
1883 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1885 if (funcs
->copy_closure
)
1886 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1889 /* If type has a dynamic resolved location property
1890 update it's value address. */
1891 type
= value_type (whole
);
1892 if (NULL
!= TYPE_DATA_LOCATION (type
)
1893 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1894 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1897 /* Access to the value history. */
1899 /* Record a new value in the value history.
1900 Returns the absolute history index of the entry. */
1903 record_latest_value (struct value
*val
)
1907 /* We don't want this value to have anything to do with the inferior anymore.
1908 In particular, "set $1 = 50" should not affect the variable from which
1909 the value was taken, and fast watchpoints should be able to assume that
1910 a value on the value history never changes. */
1911 if (value_lazy (val
))
1912 value_fetch_lazy (val
);
1913 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1914 from. This is a bit dubious, because then *&$1 does not just return $1
1915 but the current contents of that location. c'est la vie... */
1916 val
->modifiable
= 0;
1918 /* The value may have already been released, in which case we're adding a
1919 new reference for its entry in the history. That is why we call
1920 release_value_or_incref here instead of release_value. */
1921 release_value_or_incref (val
);
1923 /* Here we treat value_history_count as origin-zero
1924 and applying to the value being stored now. */
1926 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1929 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1931 newobj
->next
= value_history_chain
;
1932 value_history_chain
= newobj
;
1935 value_history_chain
->values
[i
] = val
;
1937 /* Now we regard value_history_count as origin-one
1938 and applying to the value just stored. */
1940 return ++value_history_count
;
1943 /* Return a copy of the value in the history with sequence number NUM. */
1946 access_value_history (int num
)
1948 struct value_history_chunk
*chunk
;
1953 absnum
+= value_history_count
;
1958 error (_("The history is empty."));
1960 error (_("There is only one value in the history."));
1962 error (_("History does not go back to $$%d."), -num
);
1964 if (absnum
> value_history_count
)
1965 error (_("History has not yet reached $%d."), absnum
);
1969 /* Now absnum is always absolute and origin zero. */
1971 chunk
= value_history_chain
;
1972 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1973 - absnum
/ VALUE_HISTORY_CHUNK
;
1975 chunk
= chunk
->next
;
1977 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1981 show_values (char *num_exp
, int from_tty
)
1989 /* "show values +" should print from the stored position.
1990 "show values <exp>" should print around value number <exp>. */
1991 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1992 num
= parse_and_eval_long (num_exp
) - 5;
1996 /* "show values" means print the last 10 values. */
1997 num
= value_history_count
- 9;
2003 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
2005 struct value_print_options opts
;
2007 val
= access_value_history (i
);
2008 printf_filtered (("$%d = "), i
);
2009 get_user_print_options (&opts
);
2010 value_print (val
, gdb_stdout
, &opts
);
2011 printf_filtered (("\n"));
2014 /* The next "show values +" should start after what we just printed. */
2017 /* Hitting just return after this command should do the same thing as
2018 "show values +". If num_exp is null, this is unnecessary, since
2019 "show values +" is not useful after "show values". */
2020 if (from_tty
&& num_exp
)
2027 enum internalvar_kind
2029 /* The internal variable is empty. */
2032 /* The value of the internal variable is provided directly as
2033 a GDB value object. */
2036 /* A fresh value is computed via a call-back routine on every
2037 access to the internal variable. */
2038 INTERNALVAR_MAKE_VALUE
,
2040 /* The internal variable holds a GDB internal convenience function. */
2041 INTERNALVAR_FUNCTION
,
2043 /* The variable holds an integer value. */
2044 INTERNALVAR_INTEGER
,
2046 /* The variable holds a GDB-provided string. */
2050 union internalvar_data
2052 /* A value object used with INTERNALVAR_VALUE. */
2053 struct value
*value
;
2055 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2058 /* The functions to call. */
2059 const struct internalvar_funcs
*functions
;
2061 /* The function's user-data. */
2065 /* The internal function used with INTERNALVAR_FUNCTION. */
2068 struct internal_function
*function
;
2069 /* True if this is the canonical name for the function. */
2073 /* An integer value used with INTERNALVAR_INTEGER. */
2076 /* If type is non-NULL, it will be used as the type to generate
2077 a value for this internal variable. If type is NULL, a default
2078 integer type for the architecture is used. */
2083 /* A string value used with INTERNALVAR_STRING. */
2087 /* Internal variables. These are variables within the debugger
2088 that hold values assigned by debugger commands.
2089 The user refers to them with a '$' prefix
2090 that does not appear in the variable names stored internally. */
2094 struct internalvar
*next
;
2097 /* We support various different kinds of content of an internal variable.
2098 enum internalvar_kind specifies the kind, and union internalvar_data
2099 provides the data associated with this particular kind. */
2101 enum internalvar_kind kind
;
2103 union internalvar_data u
;
2106 static struct internalvar
*internalvars
;
2108 /* If the variable does not already exist create it and give it the
2109 value given. If no value is given then the default is zero. */
2111 init_if_undefined_command (char* args
, int from_tty
)
2113 struct internalvar
* intvar
;
2115 /* Parse the expression - this is taken from set_command(). */
2116 expression_up expr
= parse_expression (args
);
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
.get ());
2138 /* Look up an internal variable with name NAME. NAME should not
2139 normally include a dollar sign.
2141 If the specified internal variable does not exist,
2142 the return value is NULL. */
2144 struct internalvar
*
2145 lookup_only_internalvar (const char *name
)
2147 struct internalvar
*var
;
2149 for (var
= internalvars
; var
; var
= var
->next
)
2150 if (strcmp (var
->name
, name
) == 0)
2156 /* Complete NAME by comparing it to the names of internal variables.
2157 Returns a vector of newly allocated strings, or NULL if no matches
2161 complete_internalvar (const char *name
)
2163 VEC (char_ptr
) *result
= NULL
;
2164 struct internalvar
*var
;
2167 len
= strlen (name
);
2169 for (var
= internalvars
; var
; var
= var
->next
)
2170 if (strncmp (var
->name
, name
, len
) == 0)
2172 char *r
= xstrdup (var
->name
);
2174 VEC_safe_push (char_ptr
, result
, r
);
2180 /* Create an internal variable with name NAME and with a void value.
2181 NAME should not normally include a dollar sign. */
2183 struct internalvar
*
2184 create_internalvar (const char *name
)
2186 struct internalvar
*var
= XNEW (struct internalvar
);
2188 var
->name
= concat (name
, (char *)NULL
);
2189 var
->kind
= INTERNALVAR_VOID
;
2190 var
->next
= internalvars
;
2195 /* Create an internal variable with name NAME and register FUN as the
2196 function that value_of_internalvar uses to create a value whenever
2197 this variable is referenced. NAME should not normally include a
2198 dollar sign. DATA is passed uninterpreted to FUN when it is
2199 called. CLEANUP, if not NULL, is called when the internal variable
2200 is destroyed. It is passed DATA as its only argument. */
2202 struct internalvar
*
2203 create_internalvar_type_lazy (const char *name
,
2204 const struct internalvar_funcs
*funcs
,
2207 struct internalvar
*var
= create_internalvar (name
);
2209 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2210 var
->u
.make_value
.functions
= funcs
;
2211 var
->u
.make_value
.data
= data
;
2215 /* See documentation in value.h. */
2218 compile_internalvar_to_ax (struct internalvar
*var
,
2219 struct agent_expr
*expr
,
2220 struct axs_value
*value
)
2222 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2223 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2226 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2227 var
->u
.make_value
.data
);
2231 /* Look up an internal variable with name NAME. NAME should not
2232 normally include a dollar sign.
2234 If the specified internal variable does not exist,
2235 one is created, with a void value. */
2237 struct internalvar
*
2238 lookup_internalvar (const char *name
)
2240 struct internalvar
*var
;
2242 var
= lookup_only_internalvar (name
);
2246 return create_internalvar (name
);
2249 /* Return current value of internal variable VAR. For variables that
2250 are not inherently typed, use a value type appropriate for GDBARCH. */
2253 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2256 struct trace_state_variable
*tsv
;
2258 /* If there is a trace state variable of the same name, assume that
2259 is what we really want to see. */
2260 tsv
= find_trace_state_variable (var
->name
);
2263 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2265 if (tsv
->value_known
)
2266 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2269 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2275 case INTERNALVAR_VOID
:
2276 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2279 case INTERNALVAR_FUNCTION
:
2280 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2283 case INTERNALVAR_INTEGER
:
2284 if (!var
->u
.integer
.type
)
2285 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2286 var
->u
.integer
.val
);
2288 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2291 case INTERNALVAR_STRING
:
2292 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2293 builtin_type (gdbarch
)->builtin_char
);
2296 case INTERNALVAR_VALUE
:
2297 val
= value_copy (var
->u
.value
);
2298 if (value_lazy (val
))
2299 value_fetch_lazy (val
);
2302 case INTERNALVAR_MAKE_VALUE
:
2303 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2304 var
->u
.make_value
.data
);
2308 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2311 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2312 on this value go back to affect the original internal variable.
2314 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2315 no underlying modifyable state in the internal variable.
2317 Likewise, if the variable's value is a computed lvalue, we want
2318 references to it to produce another computed lvalue, where
2319 references and assignments actually operate through the
2320 computed value's functions.
2322 This means that internal variables with computed values
2323 behave a little differently from other internal variables:
2324 assignments to them don't just replace the previous value
2325 altogether. At the moment, this seems like the behavior we
2328 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2329 && val
->lval
!= lval_computed
)
2331 VALUE_LVAL (val
) = lval_internalvar
;
2332 VALUE_INTERNALVAR (val
) = var
;
2339 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2341 if (var
->kind
== INTERNALVAR_INTEGER
)
2343 *result
= var
->u
.integer
.val
;
2347 if (var
->kind
== INTERNALVAR_VALUE
)
2349 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2351 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2353 *result
= value_as_long (var
->u
.value
);
2362 get_internalvar_function (struct internalvar
*var
,
2363 struct internal_function
**result
)
2367 case INTERNALVAR_FUNCTION
:
2368 *result
= var
->u
.fn
.function
;
2377 set_internalvar_component (struct internalvar
*var
,
2378 LONGEST offset
, LONGEST bitpos
,
2379 LONGEST bitsize
, struct value
*newval
)
2382 struct gdbarch
*arch
;
2387 case INTERNALVAR_VALUE
:
2388 addr
= value_contents_writeable (var
->u
.value
);
2389 arch
= get_value_arch (var
->u
.value
);
2390 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2393 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2394 value_as_long (newval
), bitpos
, bitsize
);
2396 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2397 TYPE_LENGTH (value_type (newval
)));
2401 /* We can never get a component of any other kind. */
2402 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2407 set_internalvar (struct internalvar
*var
, struct value
*val
)
2409 enum internalvar_kind new_kind
;
2410 union internalvar_data new_data
= { 0 };
2412 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2413 error (_("Cannot overwrite convenience function %s"), var
->name
);
2415 /* Prepare new contents. */
2416 switch (TYPE_CODE (check_typedef (value_type (val
))))
2418 case TYPE_CODE_VOID
:
2419 new_kind
= INTERNALVAR_VOID
;
2422 case TYPE_CODE_INTERNAL_FUNCTION
:
2423 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2424 new_kind
= INTERNALVAR_FUNCTION
;
2425 get_internalvar_function (VALUE_INTERNALVAR (val
),
2426 &new_data
.fn
.function
);
2427 /* Copies created here are never canonical. */
2431 new_kind
= INTERNALVAR_VALUE
;
2432 new_data
.value
= value_copy (val
);
2433 new_data
.value
->modifiable
= 1;
2435 /* Force the value to be fetched from the target now, to avoid problems
2436 later when this internalvar is referenced and the target is gone or
2438 if (value_lazy (new_data
.value
))
2439 value_fetch_lazy (new_data
.value
);
2441 /* Release the value from the value chain to prevent it from being
2442 deleted by free_all_values. From here on this function should not
2443 call error () until new_data is installed into the var->u to avoid
2445 release_value (new_data
.value
);
2447 /* Internal variables which are created from values with a dynamic
2448 location don't need the location property of the origin anymore.
2449 The resolved dynamic location is used prior then any other address
2450 when accessing the value.
2451 If we keep it, we would still refer to the origin value.
2452 Remove the location property in case it exist. */
2453 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2458 /* Clean up old contents. */
2459 clear_internalvar (var
);
2462 var
->kind
= new_kind
;
2464 /* End code which must not call error(). */
2468 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2470 /* Clean up old contents. */
2471 clear_internalvar (var
);
2473 var
->kind
= INTERNALVAR_INTEGER
;
2474 var
->u
.integer
.type
= NULL
;
2475 var
->u
.integer
.val
= l
;
2479 set_internalvar_string (struct internalvar
*var
, const char *string
)
2481 /* Clean up old contents. */
2482 clear_internalvar (var
);
2484 var
->kind
= INTERNALVAR_STRING
;
2485 var
->u
.string
= xstrdup (string
);
2489 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2491 /* Clean up old contents. */
2492 clear_internalvar (var
);
2494 var
->kind
= INTERNALVAR_FUNCTION
;
2495 var
->u
.fn
.function
= f
;
2496 var
->u
.fn
.canonical
= 1;
2497 /* Variables installed here are always the canonical version. */
2501 clear_internalvar (struct internalvar
*var
)
2503 /* Clean up old contents. */
2506 case INTERNALVAR_VALUE
:
2507 value_free (var
->u
.value
);
2510 case INTERNALVAR_STRING
:
2511 xfree (var
->u
.string
);
2514 case INTERNALVAR_MAKE_VALUE
:
2515 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2516 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2523 /* Reset to void kind. */
2524 var
->kind
= INTERNALVAR_VOID
;
2528 internalvar_name (const struct internalvar
*var
)
2533 static struct internal_function
*
2534 create_internal_function (const char *name
,
2535 internal_function_fn handler
, void *cookie
)
2537 struct internal_function
*ifn
= XNEW (struct internal_function
);
2539 ifn
->name
= xstrdup (name
);
2540 ifn
->handler
= handler
;
2541 ifn
->cookie
= cookie
;
2546 value_internal_function_name (struct value
*val
)
2548 struct internal_function
*ifn
;
2551 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2552 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2553 gdb_assert (result
);
2559 call_internal_function (struct gdbarch
*gdbarch
,
2560 const struct language_defn
*language
,
2561 struct value
*func
, int argc
, struct value
**argv
)
2563 struct internal_function
*ifn
;
2566 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2567 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2568 gdb_assert (result
);
2570 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2573 /* The 'function' command. This does nothing -- it is just a
2574 placeholder to let "help function NAME" work. This is also used as
2575 the implementation of the sub-command that is created when
2576 registering an internal function. */
2578 function_command (char *command
, int from_tty
)
2583 /* Clean up if an internal function's command is destroyed. */
2585 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2587 xfree ((char *) self
->name
);
2588 xfree ((char *) self
->doc
);
2591 /* Add a new internal function. NAME is the name of the function; DOC
2592 is a documentation string describing the function. HANDLER is
2593 called when the function is invoked. COOKIE is an arbitrary
2594 pointer which is passed to HANDLER and is intended for "user
2597 add_internal_function (const char *name
, const char *doc
,
2598 internal_function_fn handler
, void *cookie
)
2600 struct cmd_list_element
*cmd
;
2601 struct internal_function
*ifn
;
2602 struct internalvar
*var
= lookup_internalvar (name
);
2604 ifn
= create_internal_function (name
, handler
, cookie
);
2605 set_internalvar_function (var
, ifn
);
2607 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2609 cmd
->destroyer
= function_destroyer
;
2612 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2613 prevent cycles / duplicates. */
2616 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2617 htab_t copied_types
)
2619 if (TYPE_OBJFILE (value
->type
) == objfile
)
2620 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2622 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2623 value
->enclosing_type
= copy_type_recursive (objfile
,
2624 value
->enclosing_type
,
2628 /* Likewise for internal variable VAR. */
2631 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2632 htab_t copied_types
)
2636 case INTERNALVAR_INTEGER
:
2637 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2639 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2642 case INTERNALVAR_VALUE
:
2643 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2648 /* Update the internal variables and value history when OBJFILE is
2649 discarded; we must copy the types out of the objfile. New global types
2650 will be created for every convenience variable which currently points to
2651 this objfile's types, and the convenience variables will be adjusted to
2652 use the new global types. */
2655 preserve_values (struct objfile
*objfile
)
2657 htab_t copied_types
;
2658 struct value_history_chunk
*cur
;
2659 struct internalvar
*var
;
2662 /* Create the hash table. We allocate on the objfile's obstack, since
2663 it is soon to be deleted. */
2664 copied_types
= create_copied_types_hash (objfile
);
2666 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2667 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2669 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2671 for (var
= internalvars
; var
; var
= var
->next
)
2672 preserve_one_internalvar (var
, objfile
, copied_types
);
2674 preserve_ext_lang_values (objfile
, copied_types
);
2676 htab_delete (copied_types
);
2680 show_convenience (char *ignore
, int from_tty
)
2682 struct gdbarch
*gdbarch
= get_current_arch ();
2683 struct internalvar
*var
;
2685 struct value_print_options opts
;
2687 get_user_print_options (&opts
);
2688 for (var
= internalvars
; var
; var
= var
->next
)
2695 printf_filtered (("$%s = "), var
->name
);
2701 val
= value_of_internalvar (gdbarch
, var
);
2702 value_print (val
, gdb_stdout
, &opts
);
2704 CATCH (ex
, RETURN_MASK_ERROR
)
2706 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2710 printf_filtered (("\n"));
2714 /* This text does not mention convenience functions on purpose.
2715 The user can't create them except via Python, and if Python support
2716 is installed this message will never be printed ($_streq will
2718 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2719 "Convenience variables have "
2720 "names starting with \"$\";\n"
2721 "use \"set\" as in \"set "
2722 "$foo = 5\" to define them.\n"));
2726 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2729 value_of_xmethod (struct xmethod_worker
*worker
)
2731 if (worker
->value
== NULL
)
2735 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2736 v
->lval
= lval_xcallable
;
2737 v
->location
.xm_worker
= worker
;
2742 return worker
->value
;
2745 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2748 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2750 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2751 && method
->lval
== lval_xcallable
&& argc
> 0);
2753 return get_xmethod_result_type (method
->location
.xm_worker
,
2754 argv
[0], argv
+ 1, argc
- 1);
2757 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2760 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2762 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2763 && method
->lval
== lval_xcallable
&& argc
> 0);
2765 return invoke_xmethod (method
->location
.xm_worker
,
2766 argv
[0], argv
+ 1, argc
- 1);
2769 /* Extract a value as a C number (either long or double).
2770 Knows how to convert fixed values to double, or
2771 floating values to long.
2772 Does not deallocate the value. */
2775 value_as_long (struct value
*val
)
2777 /* This coerces arrays and functions, which is necessary (e.g.
2778 in disassemble_command). It also dereferences references, which
2779 I suspect is the most logical thing to do. */
2780 val
= coerce_array (val
);
2781 return unpack_long (value_type (val
), value_contents (val
));
2785 value_as_double (struct value
*val
)
2790 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2792 error (_("Invalid floating value found in program."));
2796 /* Extract a value as a C pointer. Does not deallocate the value.
2797 Note that val's type may not actually be a pointer; value_as_long
2798 handles all the cases. */
2800 value_as_address (struct value
*val
)
2802 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2804 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2805 whether we want this to be true eventually. */
2807 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2808 non-address (e.g. argument to "signal", "info break", etc.), or
2809 for pointers to char, in which the low bits *are* significant. */
2810 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2813 /* There are several targets (IA-64, PowerPC, and others) which
2814 don't represent pointers to functions as simply the address of
2815 the function's entry point. For example, on the IA-64, a
2816 function pointer points to a two-word descriptor, generated by
2817 the linker, which contains the function's entry point, and the
2818 value the IA-64 "global pointer" register should have --- to
2819 support position-independent code. The linker generates
2820 descriptors only for those functions whose addresses are taken.
2822 On such targets, it's difficult for GDB to convert an arbitrary
2823 function address into a function pointer; it has to either find
2824 an existing descriptor for that function, or call malloc and
2825 build its own. On some targets, it is impossible for GDB to
2826 build a descriptor at all: the descriptor must contain a jump
2827 instruction; data memory cannot be executed; and code memory
2830 Upon entry to this function, if VAL is a value of type `function'
2831 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2832 value_address (val) is the address of the function. This is what
2833 you'll get if you evaluate an expression like `main'. The call
2834 to COERCE_ARRAY below actually does all the usual unary
2835 conversions, which includes converting values of type `function'
2836 to `pointer to function'. This is the challenging conversion
2837 discussed above. Then, `unpack_long' will convert that pointer
2838 back into an address.
2840 So, suppose the user types `disassemble foo' on an architecture
2841 with a strange function pointer representation, on which GDB
2842 cannot build its own descriptors, and suppose further that `foo'
2843 has no linker-built descriptor. The address->pointer conversion
2844 will signal an error and prevent the command from running, even
2845 though the next step would have been to convert the pointer
2846 directly back into the same address.
2848 The following shortcut avoids this whole mess. If VAL is a
2849 function, just return its address directly. */
2850 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2851 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2852 return value_address (val
);
2854 val
= coerce_array (val
);
2856 /* Some architectures (e.g. Harvard), map instruction and data
2857 addresses onto a single large unified address space. For
2858 instance: An architecture may consider a large integer in the
2859 range 0x10000000 .. 0x1000ffff to already represent a data
2860 addresses (hence not need a pointer to address conversion) while
2861 a small integer would still need to be converted integer to
2862 pointer to address. Just assume such architectures handle all
2863 integer conversions in a single function. */
2867 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2868 must admonish GDB hackers to make sure its behavior matches the
2869 compiler's, whenever possible.
2871 In general, I think GDB should evaluate expressions the same way
2872 the compiler does. When the user copies an expression out of
2873 their source code and hands it to a `print' command, they should
2874 get the same value the compiler would have computed. Any
2875 deviation from this rule can cause major confusion and annoyance,
2876 and needs to be justified carefully. In other words, GDB doesn't
2877 really have the freedom to do these conversions in clever and
2880 AndrewC pointed out that users aren't complaining about how GDB
2881 casts integers to pointers; they are complaining that they can't
2882 take an address from a disassembly listing and give it to `x/i'.
2883 This is certainly important.
2885 Adding an architecture method like integer_to_address() certainly
2886 makes it possible for GDB to "get it right" in all circumstances
2887 --- the target has complete control over how things get done, so
2888 people can Do The Right Thing for their target without breaking
2889 anyone else. The standard doesn't specify how integers get
2890 converted to pointers; usually, the ABI doesn't either, but
2891 ABI-specific code is a more reasonable place to handle it. */
2893 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2894 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2895 && gdbarch_integer_to_address_p (gdbarch
))
2896 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2897 value_contents (val
));
2899 return unpack_long (value_type (val
), value_contents (val
));
2903 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2904 as a long, or as a double, assuming the raw data is described
2905 by type TYPE. Knows how to convert different sizes of values
2906 and can convert between fixed and floating point. We don't assume
2907 any alignment for the raw data. Return value is in host byte order.
2909 If you want functions and arrays to be coerced to pointers, and
2910 references to be dereferenced, call value_as_long() instead.
2912 C++: It is assumed that the front-end has taken care of
2913 all matters concerning pointers to members. A pointer
2914 to member which reaches here is considered to be equivalent
2915 to an INT (or some size). After all, it is only an offset. */
2918 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2920 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2921 enum type_code code
= TYPE_CODE (type
);
2922 int len
= TYPE_LENGTH (type
);
2923 int nosign
= TYPE_UNSIGNED (type
);
2927 case TYPE_CODE_TYPEDEF
:
2928 return unpack_long (check_typedef (type
), valaddr
);
2929 case TYPE_CODE_ENUM
:
2930 case TYPE_CODE_FLAGS
:
2931 case TYPE_CODE_BOOL
:
2933 case TYPE_CODE_CHAR
:
2934 case TYPE_CODE_RANGE
:
2935 case TYPE_CODE_MEMBERPTR
:
2937 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2939 return extract_signed_integer (valaddr
, len
, byte_order
);
2942 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2944 case TYPE_CODE_DECFLOAT
:
2945 /* libdecnumber has a function to convert from decimal to integer, but
2946 it doesn't work when the decimal number has a fractional part. */
2947 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2951 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2952 whether we want this to be true eventually. */
2953 return extract_typed_address (valaddr
, type
);
2956 error (_("Value can't be converted to integer."));
2958 return 0; /* Placate lint. */
2961 /* Return a double value from the specified type and address.
2962 INVP points to an int which is set to 0 for valid value,
2963 1 for invalid value (bad float format). In either case,
2964 the returned double is OK to use. Argument is in target
2965 format, result is in host format. */
2968 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2970 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2971 enum type_code code
;
2975 *invp
= 0; /* Assume valid. */
2976 type
= check_typedef (type
);
2977 code
= TYPE_CODE (type
);
2978 len
= TYPE_LENGTH (type
);
2979 nosign
= TYPE_UNSIGNED (type
);
2980 if (code
== TYPE_CODE_FLT
)
2982 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2983 floating-point value was valid (using the macro
2984 INVALID_FLOAT). That test/macro have been removed.
2986 It turns out that only the VAX defined this macro and then
2987 only in a non-portable way. Fixing the portability problem
2988 wouldn't help since the VAX floating-point code is also badly
2989 bit-rotten. The target needs to add definitions for the
2990 methods gdbarch_float_format and gdbarch_double_format - these
2991 exactly describe the target floating-point format. The
2992 problem here is that the corresponding floatformat_vax_f and
2993 floatformat_vax_d values these methods should be set to are
2994 also not defined either. Oops!
2996 Hopefully someone will add both the missing floatformat
2997 definitions and the new cases for floatformat_is_valid (). */
2999 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
3005 return extract_typed_floating (valaddr
, type
);
3007 else if (code
== TYPE_CODE_DECFLOAT
)
3008 return decimal_to_doublest (valaddr
, len
, byte_order
);
3011 /* Unsigned -- be sure we compensate for signed LONGEST. */
3012 return (ULONGEST
) unpack_long (type
, valaddr
);
3016 /* Signed -- we are OK with unpack_long. */
3017 return unpack_long (type
, valaddr
);
3021 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3022 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3023 We don't assume any alignment for the raw data. Return value is in
3026 If you want functions and arrays to be coerced to pointers, and
3027 references to be dereferenced, call value_as_address() instead.
3029 C++: It is assumed that the front-end has taken care of
3030 all matters concerning pointers to members. A pointer
3031 to member which reaches here is considered to be equivalent
3032 to an INT (or some size). After all, it is only an offset. */
3035 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3037 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3038 whether we want this to be true eventually. */
3039 return unpack_long (type
, valaddr
);
3043 /* Get the value of the FIELDNO'th field (which must be static) of
3047 value_static_field (struct type
*type
, int fieldno
)
3049 struct value
*retval
;
3051 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3053 case FIELD_LOC_KIND_PHYSADDR
:
3054 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3055 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3057 case FIELD_LOC_KIND_PHYSNAME
:
3059 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3060 /* TYPE_FIELD_NAME (type, fieldno); */
3061 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3063 if (sym
.symbol
== NULL
)
3065 /* With some compilers, e.g. HP aCC, static data members are
3066 reported as non-debuggable symbols. */
3067 struct bound_minimal_symbol msym
3068 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3071 return allocate_optimized_out_value (type
);
3074 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3075 BMSYMBOL_VALUE_ADDRESS (msym
));
3079 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3083 gdb_assert_not_reached ("unexpected field location kind");
3089 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3090 You have to be careful here, since the size of the data area for the value
3091 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3092 than the old enclosing type, you have to allocate more space for the
3096 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3098 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3100 check_type_length_before_alloc (new_encl_type
);
3102 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3105 val
->enclosing_type
= new_encl_type
;
3108 /* Given a value ARG1 (offset by OFFSET bytes)
3109 of a struct or union type ARG_TYPE,
3110 extract and return the value of one of its (non-static) fields.
3111 FIELDNO says which field. */
3114 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3115 int fieldno
, struct type
*arg_type
)
3119 struct gdbarch
*arch
= get_value_arch (arg1
);
3120 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3122 arg_type
= check_typedef (arg_type
);
3123 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3125 /* Call check_typedef on our type to make sure that, if TYPE
3126 is a TYPE_CODE_TYPEDEF, its length is set to the length
3127 of the target type instead of zero. However, we do not
3128 replace the typedef type by the target type, because we want
3129 to keep the typedef in order to be able to print the type
3130 description correctly. */
3131 check_typedef (type
);
3133 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3135 /* Handle packed fields.
3137 Create a new value for the bitfield, with bitpos and bitsize
3138 set. If possible, arrange offset and bitpos so that we can
3139 do a single aligned read of the size of the containing type.
3140 Otherwise, adjust offset to the byte containing the first
3141 bit. Assume that the address, offset, and embedded offset
3142 are sufficiently aligned. */
3144 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3145 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3147 v
= allocate_value_lazy (type
);
3148 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3149 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3150 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3151 v
->bitpos
= bitpos
% container_bitsize
;
3153 v
->bitpos
= bitpos
% 8;
3154 v
->offset
= (value_embedded_offset (arg1
)
3156 + (bitpos
- v
->bitpos
) / 8);
3157 set_value_parent (v
, arg1
);
3158 if (!value_lazy (arg1
))
3159 value_fetch_lazy (v
);
3161 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3163 /* This field is actually a base subobject, so preserve the
3164 entire object's contents for later references to virtual
3168 /* Lazy register values with offsets are not supported. */
3169 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3170 value_fetch_lazy (arg1
);
3172 /* We special case virtual inheritance here because this
3173 requires access to the contents, which we would rather avoid
3174 for references to ordinary fields of unavailable values. */
3175 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3176 boffset
= baseclass_offset (arg_type
, fieldno
,
3177 value_contents (arg1
),
3178 value_embedded_offset (arg1
),
3179 value_address (arg1
),
3182 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3184 if (value_lazy (arg1
))
3185 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3188 v
= allocate_value (value_enclosing_type (arg1
));
3189 value_contents_copy_raw (v
, 0, arg1
, 0,
3190 TYPE_LENGTH (value_enclosing_type (arg1
)));
3193 v
->offset
= value_offset (arg1
);
3194 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3196 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3198 /* Field is a dynamic data member. */
3200 gdb_assert (0 == offset
);
3201 /* We expect an already resolved data location. */
3202 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3203 /* For dynamic data types defer memory allocation
3204 until we actual access the value. */
3205 v
= allocate_value_lazy (type
);
3209 /* Plain old data member */
3210 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3211 / (HOST_CHAR_BIT
* unit_size
));
3213 /* Lazy register values with offsets are not supported. */
3214 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3215 value_fetch_lazy (arg1
);
3217 if (value_lazy (arg1
))
3218 v
= allocate_value_lazy (type
);
3221 v
= allocate_value (type
);
3222 value_contents_copy_raw (v
, value_embedded_offset (v
),
3223 arg1
, value_embedded_offset (arg1
) + offset
,
3224 type_length_units (type
));
3226 v
->offset
= (value_offset (arg1
) + offset
3227 + value_embedded_offset (arg1
));
3229 set_value_component_location (v
, arg1
);
3230 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
3231 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
3235 /* Given a value ARG1 of a struct or union type,
3236 extract and return the value of one of its (non-static) fields.
3237 FIELDNO says which field. */
3240 value_field (struct value
*arg1
, int fieldno
)
3242 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3245 /* Return a non-virtual function as a value.
3246 F is the list of member functions which contains the desired method.
3247 J is an index into F which provides the desired method.
3249 We only use the symbol for its address, so be happy with either a
3250 full symbol or a minimal symbol. */
3253 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3254 int j
, struct type
*type
,
3258 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3259 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3261 struct bound_minimal_symbol msym
;
3263 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3266 memset (&msym
, 0, sizeof (msym
));
3270 gdb_assert (sym
== NULL
);
3271 msym
= lookup_bound_minimal_symbol (physname
);
3272 if (msym
.minsym
== NULL
)
3276 v
= allocate_value (ftype
);
3279 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3283 /* The minimal symbol might point to a function descriptor;
3284 resolve it to the actual code address instead. */
3285 struct objfile
*objfile
= msym
.objfile
;
3286 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3288 set_value_address (v
,
3289 gdbarch_convert_from_func_ptr_addr
3290 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3295 if (type
!= value_type (*arg1p
))
3296 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3297 value_addr (*arg1p
)));
3299 /* Move the `this' pointer according to the offset.
3300 VALUE_OFFSET (*arg1p) += offset; */
3308 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3309 VALADDR, and store the result in *RESULT.
3310 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3312 Extracting bits depends on endianness of the machine. Compute the
3313 number of least significant bits to discard. For big endian machines,
3314 we compute the total number of bits in the anonymous object, subtract
3315 off the bit count from the MSB of the object to the MSB of the
3316 bitfield, then the size of the bitfield, which leaves the LSB discard
3317 count. For little endian machines, the discard count is simply the
3318 number of bits from the LSB of the anonymous object to the LSB of the
3321 If the field is signed, we also do sign extension. */
3324 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3325 LONGEST bitpos
, LONGEST bitsize
)
3327 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3332 LONGEST read_offset
;
3334 /* Read the minimum number of bytes required; there may not be
3335 enough bytes to read an entire ULONGEST. */
3336 field_type
= check_typedef (field_type
);
3338 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3340 bytes_read
= TYPE_LENGTH (field_type
);
3342 read_offset
= bitpos
/ 8;
3344 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3345 bytes_read
, byte_order
);
3347 /* Extract bits. See comment above. */
3349 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3350 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3352 lsbcount
= (bitpos
% 8);
3355 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3356 If the field is signed, and is negative, then sign extend. */
3358 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3360 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3362 if (!TYPE_UNSIGNED (field_type
))
3364 if (val
& (valmask
^ (valmask
>> 1)))
3374 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3375 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3376 ORIGINAL_VALUE, which must not be NULL. See
3377 unpack_value_bits_as_long for more details. */
3380 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3381 LONGEST embedded_offset
, int fieldno
,
3382 const struct value
*val
, LONGEST
*result
)
3384 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3385 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3386 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3389 gdb_assert (val
!= NULL
);
3391 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3392 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3393 || !value_bits_available (val
, bit_offset
, bitsize
))
3396 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3401 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3402 object at VALADDR. See unpack_bits_as_long for more details. */
3405 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3407 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3408 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3409 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3411 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3414 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3415 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3416 the contents in DEST_VAL, zero or sign extending if the type of
3417 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3418 VAL. If the VAL's contents required to extract the bitfield from
3419 are unavailable/optimized out, DEST_VAL is correspondingly
3420 marked unavailable/optimized out. */
3423 unpack_value_bitfield (struct value
*dest_val
,
3424 LONGEST bitpos
, LONGEST bitsize
,
3425 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3426 const struct value
*val
)
3428 enum bfd_endian byte_order
;
3431 struct type
*field_type
= value_type (dest_val
);
3433 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3435 /* First, unpack and sign extend the bitfield as if it was wholly
3436 valid. Optimized out/unavailable bits are read as zero, but
3437 that's OK, as they'll end up marked below. If the VAL is
3438 wholly-invalid we may have skipped allocating its contents,
3439 though. See allocate_optimized_out_value. */
3440 if (valaddr
!= NULL
)
3444 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3446 store_signed_integer (value_contents_raw (dest_val
),
3447 TYPE_LENGTH (field_type
), byte_order
, num
);
3450 /* Now copy the optimized out / unavailability ranges to the right
3452 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3453 if (byte_order
== BFD_ENDIAN_BIG
)
3454 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3457 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3458 val
, src_bit_offset
, bitsize
);
3461 /* Return a new value with type TYPE, which is FIELDNO field of the
3462 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3463 of VAL. If the VAL's contents required to extract the bitfield
3464 from are unavailable/optimized out, the new value is
3465 correspondingly marked unavailable/optimized out. */
3468 value_field_bitfield (struct type
*type
, int fieldno
,
3469 const gdb_byte
*valaddr
,
3470 LONGEST embedded_offset
, const struct value
*val
)
3472 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3473 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3474 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3476 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3477 valaddr
, embedded_offset
, val
);
3482 /* Modify the value of a bitfield. ADDR points to a block of memory in
3483 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3484 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3485 indicate which bits (in target bit order) comprise the bitfield.
3486 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3487 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3490 modify_field (struct type
*type
, gdb_byte
*addr
,
3491 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3493 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3495 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3498 /* Normalize BITPOS. */
3502 /* If a negative fieldval fits in the field in question, chop
3503 off the sign extension bits. */
3504 if ((~fieldval
& ~(mask
>> 1)) == 0)
3507 /* Warn if value is too big to fit in the field in question. */
3508 if (0 != (fieldval
& ~mask
))
3510 /* FIXME: would like to include fieldval in the message, but
3511 we don't have a sprintf_longest. */
3512 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3514 /* Truncate it, otherwise adjoining fields may be corrupted. */
3518 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3519 false valgrind reports. */
3521 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3522 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3524 /* Shifting for bit field depends on endianness of the target machine. */
3525 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3526 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3528 oword
&= ~(mask
<< bitpos
);
3529 oword
|= fieldval
<< bitpos
;
3531 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3534 /* Pack NUM into BUF using a target format of TYPE. */
3537 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3539 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3542 type
= check_typedef (type
);
3543 len
= TYPE_LENGTH (type
);
3545 switch (TYPE_CODE (type
))
3548 case TYPE_CODE_CHAR
:
3549 case TYPE_CODE_ENUM
:
3550 case TYPE_CODE_FLAGS
:
3551 case TYPE_CODE_BOOL
:
3552 case TYPE_CODE_RANGE
:
3553 case TYPE_CODE_MEMBERPTR
:
3554 store_signed_integer (buf
, len
, byte_order
, num
);
3559 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3563 error (_("Unexpected type (%d) encountered for integer constant."),
3569 /* Pack NUM into BUF using a target format of TYPE. */
3572 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3575 enum bfd_endian byte_order
;
3577 type
= check_typedef (type
);
3578 len
= TYPE_LENGTH (type
);
3579 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3581 switch (TYPE_CODE (type
))
3584 case TYPE_CODE_CHAR
:
3585 case TYPE_CODE_ENUM
:
3586 case TYPE_CODE_FLAGS
:
3587 case TYPE_CODE_BOOL
:
3588 case TYPE_CODE_RANGE
:
3589 case TYPE_CODE_MEMBERPTR
:
3590 store_unsigned_integer (buf
, len
, byte_order
, num
);
3595 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3599 error (_("Unexpected type (%d) encountered "
3600 "for unsigned integer constant."),
3606 /* Convert C numbers into newly allocated values. */
3609 value_from_longest (struct type
*type
, LONGEST num
)
3611 struct value
*val
= allocate_value (type
);
3613 pack_long (value_contents_raw (val
), type
, num
);
3618 /* Convert C unsigned numbers into newly allocated values. */
3621 value_from_ulongest (struct type
*type
, ULONGEST num
)
3623 struct value
*val
= allocate_value (type
);
3625 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3631 /* Create a value representing a pointer of type TYPE to the address
3635 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3637 struct value
*val
= allocate_value (type
);
3639 store_typed_address (value_contents_raw (val
),
3640 check_typedef (type
), addr
);
3645 /* Create a value of type TYPE whose contents come from VALADDR, if it
3646 is non-null, and whose memory address (in the inferior) is
3647 ADDRESS. The type of the created value may differ from the passed
3648 type TYPE. Make sure to retrieve values new type after this call.
3649 Note that TYPE is not passed through resolve_dynamic_type; this is
3650 a special API intended for use only by Ada. */
3653 value_from_contents_and_address_unresolved (struct type
*type
,
3654 const gdb_byte
*valaddr
,
3659 if (valaddr
== NULL
)
3660 v
= allocate_value_lazy (type
);
3662 v
= value_from_contents (type
, valaddr
);
3663 set_value_address (v
, address
);
3664 VALUE_LVAL (v
) = lval_memory
;
3668 /* Create a value of type TYPE whose contents come from VALADDR, if it
3669 is non-null, and whose memory address (in the inferior) is
3670 ADDRESS. The type of the created value may differ from the passed
3671 type TYPE. Make sure to retrieve values new type after this call. */
3674 value_from_contents_and_address (struct type
*type
,
3675 const gdb_byte
*valaddr
,
3678 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3679 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3682 if (valaddr
== NULL
)
3683 v
= allocate_value_lazy (resolved_type
);
3685 v
= value_from_contents (resolved_type
, valaddr
);
3686 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3687 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3688 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3689 set_value_address (v
, address
);
3690 VALUE_LVAL (v
) = lval_memory
;
3694 /* Create a value of type TYPE holding the contents CONTENTS.
3695 The new value is `not_lval'. */
3698 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3700 struct value
*result
;
3702 result
= allocate_value (type
);
3703 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3708 value_from_double (struct type
*type
, DOUBLEST num
)
3710 struct value
*val
= allocate_value (type
);
3711 struct type
*base_type
= check_typedef (type
);
3712 enum type_code code
= TYPE_CODE (base_type
);
3714 if (code
== TYPE_CODE_FLT
)
3716 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3719 error (_("Unexpected type encountered for floating constant."));
3725 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3727 struct value
*val
= allocate_value (type
);
3729 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3733 /* Extract a value from the history file. Input will be of the form
3734 $digits or $$digits. See block comment above 'write_dollar_variable'
3738 value_from_history_ref (const char *h
, const char **endp
)
3750 /* Find length of numeral string. */
3751 for (; isdigit (h
[len
]); len
++)
3754 /* Make sure numeral string is not part of an identifier. */
3755 if (h
[len
] == '_' || isalpha (h
[len
]))
3758 /* Now collect the index value. */
3763 /* For some bizarre reason, "$$" is equivalent to "$$1",
3764 rather than to "$$0" as it ought to be! */
3772 index
= -strtol (&h
[2], &local_end
, 10);
3780 /* "$" is equivalent to "$0". */
3788 index
= strtol (&h
[1], &local_end
, 10);
3793 return access_value_history (index
);
3797 coerce_ref_if_computed (const struct value
*arg
)
3799 const struct lval_funcs
*funcs
;
3801 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3804 if (value_lval_const (arg
) != lval_computed
)
3807 funcs
= value_computed_funcs (arg
);
3808 if (funcs
->coerce_ref
== NULL
)
3811 return funcs
->coerce_ref (arg
);
3814 /* Look at value.h for description. */
3817 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3818 const struct type
*original_type
,
3819 const struct value
*original_value
)
3821 /* Re-adjust type. */
3822 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3824 /* Add embedding info. */
3825 set_value_enclosing_type (value
, enc_type
);
3826 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3828 /* We may be pointing to an object of some derived type. */
3829 return value_full_object (value
, NULL
, 0, 0, 0);
3833 coerce_ref (struct value
*arg
)
3835 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3836 struct value
*retval
;
3837 struct type
*enc_type
;
3839 retval
= coerce_ref_if_computed (arg
);
3843 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3846 enc_type
= check_typedef (value_enclosing_type (arg
));
3847 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3849 retval
= value_at_lazy (enc_type
,
3850 unpack_pointer (value_type (arg
),
3851 value_contents (arg
)));
3852 enc_type
= value_type (retval
);
3853 return readjust_indirect_value_type (retval
, enc_type
,
3854 value_type_arg_tmp
, arg
);
3858 coerce_array (struct value
*arg
)
3862 arg
= coerce_ref (arg
);
3863 type
= check_typedef (value_type (arg
));
3865 switch (TYPE_CODE (type
))
3867 case TYPE_CODE_ARRAY
:
3868 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3869 arg
= value_coerce_array (arg
);
3871 case TYPE_CODE_FUNC
:
3872 arg
= value_coerce_function (arg
);
3879 /* Return the return value convention that will be used for the
3882 enum return_value_convention
3883 struct_return_convention (struct gdbarch
*gdbarch
,
3884 struct value
*function
, struct type
*value_type
)
3886 enum type_code code
= TYPE_CODE (value_type
);
3888 if (code
== TYPE_CODE_ERROR
)
3889 error (_("Function return type unknown."));
3891 /* Probe the architecture for the return-value convention. */
3892 return gdbarch_return_value (gdbarch
, function
, value_type
,
3896 /* Return true if the function returning the specified type is using
3897 the convention of returning structures in memory (passing in the
3898 address as a hidden first parameter). */
3901 using_struct_return (struct gdbarch
*gdbarch
,
3902 struct value
*function
, struct type
*value_type
)
3904 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3905 /* A void return value is never in memory. See also corresponding
3906 code in "print_return_value". */
3909 return (struct_return_convention (gdbarch
, function
, value_type
)
3910 != RETURN_VALUE_REGISTER_CONVENTION
);
3913 /* Set the initialized field in a value struct. */
3916 set_value_initialized (struct value
*val
, int status
)
3918 val
->initialized
= status
;
3921 /* Return the initialized field in a value struct. */
3924 value_initialized (const struct value
*val
)
3926 return val
->initialized
;
3929 /* Load the actual content of a lazy value. Fetch the data from the
3930 user's process and clear the lazy flag to indicate that the data in
3931 the buffer is valid.
3933 If the value is zero-length, we avoid calling read_memory, which
3934 would abort. We mark the value as fetched anyway -- all 0 bytes of
3938 value_fetch_lazy (struct value
*val
)
3940 gdb_assert (value_lazy (val
));
3941 allocate_value_contents (val
);
3942 /* A value is either lazy, or fully fetched. The
3943 availability/validity is only established as we try to fetch a
3945 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3946 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3947 if (value_bitsize (val
))
3949 /* To read a lazy bitfield, read the entire enclosing value. This
3950 prevents reading the same block of (possibly volatile) memory once
3951 per bitfield. It would be even better to read only the containing
3952 word, but we have no way to record that just specific bits of a
3953 value have been fetched. */
3954 struct type
*type
= check_typedef (value_type (val
));
3955 struct value
*parent
= value_parent (val
);
3957 if (value_lazy (parent
))
3958 value_fetch_lazy (parent
);
3960 unpack_value_bitfield (val
,
3961 value_bitpos (val
), value_bitsize (val
),
3962 value_contents_for_printing (parent
),
3963 value_offset (val
), parent
);
3965 else if (VALUE_LVAL (val
) == lval_memory
)
3967 CORE_ADDR addr
= value_address (val
);
3968 struct type
*type
= check_typedef (value_enclosing_type (val
));
3970 if (TYPE_LENGTH (type
))
3971 read_value_memory (val
, 0, value_stack (val
),
3972 addr
, value_contents_all_raw (val
),
3973 type_length_units (type
));
3975 else if (VALUE_LVAL (val
) == lval_register
)
3977 struct frame_info
*frame
;
3979 struct type
*type
= check_typedef (value_type (val
));
3980 struct value
*new_val
= val
, *mark
= value_mark ();
3982 /* Offsets are not supported here; lazy register values must
3983 refer to the entire register. */
3984 gdb_assert (value_offset (val
) == 0);
3986 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3988 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3990 frame
= frame_find_by_id (frame_id
);
3991 regnum
= VALUE_REGNUM (new_val
);
3993 gdb_assert (frame
!= NULL
);
3995 /* Convertible register routines are used for multi-register
3996 values and for interpretation in different types
3997 (e.g. float or int from a double register). Lazy
3998 register values should have the register's natural type,
3999 so they do not apply. */
4000 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
4003 new_val
= get_frame_register_value (frame
, regnum
);
4005 /* If we get another lazy lval_register value, it means the
4006 register is found by reading it from the next frame.
4007 get_frame_register_value should never return a value with
4008 the frame id pointing to FRAME. If it does, it means we
4009 either have two consecutive frames with the same frame id
4010 in the frame chain, or some code is trying to unwind
4011 behind get_prev_frame's back (e.g., a frame unwind
4012 sniffer trying to unwind), bypassing its validations. In
4013 any case, it should always be an internal error to end up
4014 in this situation. */
4015 if (VALUE_LVAL (new_val
) == lval_register
4016 && value_lazy (new_val
)
4017 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
4018 internal_error (__FILE__
, __LINE__
,
4019 _("infinite loop while fetching a register"));
4022 /* If it's still lazy (for instance, a saved register on the
4023 stack), fetch it. */
4024 if (value_lazy (new_val
))
4025 value_fetch_lazy (new_val
);
4027 /* Copy the contents and the unavailability/optimized-out
4028 meta-data from NEW_VAL to VAL. */
4029 set_value_lazy (val
, 0);
4030 value_contents_copy (val
, value_embedded_offset (val
),
4031 new_val
, value_embedded_offset (new_val
),
4032 type_length_units (type
));
4036 struct gdbarch
*gdbarch
;
4037 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4038 regnum
= VALUE_REGNUM (val
);
4039 gdbarch
= get_frame_arch (frame
);
4041 fprintf_unfiltered (gdb_stdlog
,
4042 "{ value_fetch_lazy "
4043 "(frame=%d,regnum=%d(%s),...) ",
4044 frame_relative_level (frame
), regnum
,
4045 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4047 fprintf_unfiltered (gdb_stdlog
, "->");
4048 if (value_optimized_out (new_val
))
4050 fprintf_unfiltered (gdb_stdlog
, " ");
4051 val_print_optimized_out (new_val
, gdb_stdlog
);
4056 const gdb_byte
*buf
= value_contents (new_val
);
4058 if (VALUE_LVAL (new_val
) == lval_register
)
4059 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4060 VALUE_REGNUM (new_val
));
4061 else if (VALUE_LVAL (new_val
) == lval_memory
)
4062 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4064 value_address (new_val
)));
4066 fprintf_unfiltered (gdb_stdlog
, " computed");
4068 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4069 fprintf_unfiltered (gdb_stdlog
, "[");
4070 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4071 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4072 fprintf_unfiltered (gdb_stdlog
, "]");
4075 fprintf_unfiltered (gdb_stdlog
, " }\n");
4078 /* Dispose of the intermediate values. This prevents
4079 watchpoints from trying to watch the saved frame pointer. */
4080 value_free_to_mark (mark
);
4082 else if (VALUE_LVAL (val
) == lval_computed
4083 && value_computed_funcs (val
)->read
!= NULL
)
4084 value_computed_funcs (val
)->read (val
);
4086 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4088 set_value_lazy (val
, 0);
4091 /* Implementation of the convenience function $_isvoid. */
4093 static struct value
*
4094 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4095 const struct language_defn
*language
,
4096 void *cookie
, int argc
, struct value
**argv
)
4101 error (_("You must provide one argument for $_isvoid."));
4103 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4105 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4109 _initialize_values (void)
4111 add_cmd ("convenience", no_class
, show_convenience
, _("\
4112 Debugger convenience (\"$foo\") variables and functions.\n\
4113 Convenience variables are created when you assign them values;\n\
4114 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4116 A few convenience variables are given values automatically:\n\
4117 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4118 \"$__\" holds the contents of the last address examined with \"x\"."
4121 Convenience functions are defined via the Python API."
4124 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4126 add_cmd ("values", no_set_class
, show_values
, _("\
4127 Elements of value history around item number IDX (or last ten)."),
4130 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4131 Initialize a convenience variable if necessary.\n\
4132 init-if-undefined VARIABLE = EXPRESSION\n\
4133 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4134 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4135 VARIABLE is already initialized."));
4137 add_prefix_cmd ("function", no_class
, function_command
, _("\
4138 Placeholder command for showing help on convenience functions."),
4139 &functionlist
, "function ", 0, &cmdlist
);
4141 add_internal_function ("_isvoid", _("\
4142 Check whether an expression is void.\n\
4143 Usage: $_isvoid (expression)\n\
4144 Return 1 if the expression is void, zero otherwise."),
4145 isvoid_internal_fn
, NULL
);
4147 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4148 class_support
, &max_value_size
, _("\
4149 Set maximum sized value gdb will load from the inferior."), _("\
4150 Show maximum sized value gdb will load from the inferior."), _("\
4151 Use this to control the maximum size, in bytes, of a value that gdb\n\
4152 will load from the inferior. Setting this value to 'unlimited'\n\
4153 disables checking.\n\
4154 Setting this does not invalidate already allocated values, it only\n\
4155 prevents future values, larger than this size, from being allocated."),
4157 show_max_value_size
,
4158 &setlist
, &showlist
);