1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2017 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 /* Location of value (if lval). */
211 /* If lval == lval_memory, this is the address in the inferior */
214 /*If lval == lval_register, the value is from a register. */
217 /* Register number. */
219 /* Frame ID of "next" frame to which a register value is relative.
220 If the register value is found relative to frame F, then the
221 frame id of F->next will be stored in next_frame_id. */
222 struct frame_id next_frame_id
;
225 /* Pointer to internal variable. */
226 struct internalvar
*internalvar
;
228 /* Pointer to xmethod worker. */
229 struct xmethod_worker
*xm_worker
;
231 /* If lval == lval_computed, this is a set of function pointers
232 to use to access and describe the value, and a closure pointer
236 /* Functions to call. */
237 const struct lval_funcs
*funcs
;
239 /* Closure for those functions to use. */
244 /* Describes offset of a value within lval of a structure in target
245 addressable memory units. Note also the member embedded_offset
249 /* Only used for bitfields; number of bits contained in them. */
252 /* Only used for bitfields; position of start of field. For
253 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
254 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
257 /* The number of references to this value. When a value is created,
258 the value chain holds a reference, so REFERENCE_COUNT is 1. If
259 release_value is called, this value is removed from the chain but
260 the caller of release_value now has a reference to this value.
261 The caller must arrange for a call to value_free later. */
264 /* Only used for bitfields; the containing value. This allows a
265 single read from the target when displaying multiple
267 struct value
*parent
;
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;
950 val
->embedded_offset
= 0;
951 val
->pointed_to_offset
= 0;
953 val
->initialized
= 1; /* Default to initialized. */
955 /* Values start out on the all_values chain. */
956 val
->reference_count
= 1;
961 /* The maximum size, in bytes, that GDB will try to allocate for a value.
962 The initial value of 64k was not selected for any specific reason, it is
963 just a reasonable starting point. */
965 static int max_value_size
= 65536; /* 64k bytes */
967 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
968 LONGEST, otherwise GDB will not be able to parse integer values from the
969 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
970 be unable to parse "set max-value-size 2".
972 As we want a consistent GDB experience across hosts with different sizes
973 of LONGEST, this arbitrary minimum value was selected, so long as this
974 is bigger than LONGEST on all GDB supported hosts we're fine. */
976 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
977 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
979 /* Implement the "set max-value-size" command. */
982 set_max_value_size (char *args
, int from_tty
,
983 struct cmd_list_element
*c
)
985 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
987 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
989 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
990 error (_("max-value-size set too low, increasing to %d bytes"),
995 /* Implement the "show max-value-size" command. */
998 show_max_value_size (struct ui_file
*file
, int from_tty
,
999 struct cmd_list_element
*c
, const char *value
)
1001 if (max_value_size
== -1)
1002 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
1004 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
1008 /* Called before we attempt to allocate or reallocate a buffer for the
1009 contents of a value. TYPE is the type of the value for which we are
1010 allocating the buffer. If the buffer is too large (based on the user
1011 controllable setting) then throw an error. If this function returns
1012 then we should attempt to allocate the buffer. */
1015 check_type_length_before_alloc (const struct type
*type
)
1017 unsigned int length
= TYPE_LENGTH (type
);
1019 if (max_value_size
> -1 && length
> max_value_size
)
1021 if (TYPE_NAME (type
) != NULL
)
1022 error (_("value of type `%s' requires %u bytes, which is more "
1023 "than max-value-size"), TYPE_NAME (type
), length
);
1025 error (_("value requires %u bytes, which is more than "
1026 "max-value-size"), length
);
1030 /* Allocate the contents of VAL if it has not been allocated yet. */
1033 allocate_value_contents (struct value
*val
)
1037 check_type_length_before_alloc (val
->enclosing_type
);
1039 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1043 /* Allocate a value and its contents for type TYPE. */
1046 allocate_value (struct type
*type
)
1048 struct value
*val
= allocate_value_lazy (type
);
1050 allocate_value_contents (val
);
1055 /* Allocate a value that has the correct length
1056 for COUNT repetitions of type TYPE. */
1059 allocate_repeat_value (struct type
*type
, int count
)
1061 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1062 /* FIXME-type-allocation: need a way to free this type when we are
1064 struct type
*array_type
1065 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1067 return allocate_value (array_type
);
1071 allocate_computed_value (struct type
*type
,
1072 const struct lval_funcs
*funcs
,
1075 struct value
*v
= allocate_value_lazy (type
);
1077 VALUE_LVAL (v
) = lval_computed
;
1078 v
->location
.computed
.funcs
= funcs
;
1079 v
->location
.computed
.closure
= closure
;
1084 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1087 allocate_optimized_out_value (struct type
*type
)
1089 struct value
*retval
= allocate_value_lazy (type
);
1091 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1092 set_value_lazy (retval
, 0);
1096 /* Accessor methods. */
1099 value_next (const struct value
*value
)
1105 value_type (const struct value
*value
)
1110 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1116 value_offset (const struct value
*value
)
1118 return value
->offset
;
1121 set_value_offset (struct value
*value
, LONGEST offset
)
1123 value
->offset
= offset
;
1127 value_bitpos (const struct value
*value
)
1129 return value
->bitpos
;
1132 set_value_bitpos (struct value
*value
, LONGEST bit
)
1134 value
->bitpos
= bit
;
1138 value_bitsize (const struct value
*value
)
1140 return value
->bitsize
;
1143 set_value_bitsize (struct value
*value
, LONGEST bit
)
1145 value
->bitsize
= bit
;
1149 value_parent (const struct value
*value
)
1151 return value
->parent
;
1157 set_value_parent (struct value
*value
, struct value
*parent
)
1159 struct value
*old
= value
->parent
;
1161 value
->parent
= parent
;
1163 value_incref (parent
);
1168 value_contents_raw (struct value
*value
)
1170 struct gdbarch
*arch
= get_value_arch (value
);
1171 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1173 allocate_value_contents (value
);
1174 return value
->contents
+ value
->embedded_offset
* unit_size
;
1178 value_contents_all_raw (struct value
*value
)
1180 allocate_value_contents (value
);
1181 return value
->contents
;
1185 value_enclosing_type (const struct value
*value
)
1187 return value
->enclosing_type
;
1190 /* Look at value.h for description. */
1193 value_actual_type (struct value
*value
, int resolve_simple_types
,
1194 int *real_type_found
)
1196 struct value_print_options opts
;
1197 struct type
*result
;
1199 get_user_print_options (&opts
);
1201 if (real_type_found
)
1202 *real_type_found
= 0;
1203 result
= value_type (value
);
1204 if (opts
.objectprint
)
1206 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1207 fetch its rtti type. */
1208 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1209 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1210 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1212 && !value_optimized_out (value
))
1214 struct type
*real_type
;
1216 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1219 if (real_type_found
)
1220 *real_type_found
= 1;
1224 else if (resolve_simple_types
)
1226 if (real_type_found
)
1227 *real_type_found
= 1;
1228 result
= value_enclosing_type (value
);
1236 error_value_optimized_out (void)
1238 error (_("value has been optimized out"));
1242 require_not_optimized_out (const struct value
*value
)
1244 if (!VEC_empty (range_s
, value
->optimized_out
))
1246 if (value
->lval
== lval_register
)
1247 error (_("register has not been saved in frame"));
1249 error_value_optimized_out ();
1254 require_available (const struct value
*value
)
1256 if (!VEC_empty (range_s
, value
->unavailable
))
1257 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1261 value_contents_for_printing (struct value
*value
)
1264 value_fetch_lazy (value
);
1265 return value
->contents
;
1269 value_contents_for_printing_const (const struct value
*value
)
1271 gdb_assert (!value
->lazy
);
1272 return value
->contents
;
1276 value_contents_all (struct value
*value
)
1278 const gdb_byte
*result
= value_contents_for_printing (value
);
1279 require_not_optimized_out (value
);
1280 require_available (value
);
1284 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1285 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1288 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1289 VEC (range_s
) *src_range
, int src_bit_offset
,
1295 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1299 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1300 h
= std::min (r
->offset
+ r
->length
,
1301 (LONGEST
) src_bit_offset
+ bit_length
);
1304 insert_into_bit_range_vector (dst_range
,
1305 dst_bit_offset
+ (l
- src_bit_offset
),
1310 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1311 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1314 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1315 const struct value
*src
, int src_bit_offset
,
1318 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1319 src
->unavailable
, src_bit_offset
,
1321 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1322 src
->optimized_out
, src_bit_offset
,
1326 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1327 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1328 contents, starting at DST_OFFSET. If unavailable contents are
1329 being copied from SRC, the corresponding DST contents are marked
1330 unavailable accordingly. Neither DST nor SRC may be lazy
1333 It is assumed the contents of DST in the [DST_OFFSET,
1334 DST_OFFSET+LENGTH) range are wholly available. */
1337 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1338 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1340 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1341 struct gdbarch
*arch
= get_value_arch (src
);
1342 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1344 /* A lazy DST would make that this copy operation useless, since as
1345 soon as DST's contents were un-lazied (by a later value_contents
1346 call, say), the contents would be overwritten. A lazy SRC would
1347 mean we'd be copying garbage. */
1348 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1350 /* The overwritten DST range gets unavailability ORed in, not
1351 replaced. Make sure to remember to implement replacing if it
1352 turns out actually necessary. */
1353 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1354 gdb_assert (!value_bits_any_optimized_out (dst
,
1355 TARGET_CHAR_BIT
* dst_offset
,
1356 TARGET_CHAR_BIT
* length
));
1358 /* Copy the data. */
1359 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1360 value_contents_all_raw (src
) + src_offset
* unit_size
,
1361 length
* unit_size
);
1363 /* Copy the meta-data, adjusted. */
1364 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1365 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1366 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1368 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1369 src
, src_bit_offset
,
1373 /* Copy LENGTH bytes of SRC value's (all) contents
1374 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1375 (all) contents, starting at DST_OFFSET. If unavailable contents
1376 are being copied from SRC, the corresponding DST contents are
1377 marked unavailable accordingly. DST must not be lazy. If SRC is
1378 lazy, it will be fetched now.
1380 It is assumed the contents of DST in the [DST_OFFSET,
1381 DST_OFFSET+LENGTH) range are wholly available. */
1384 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1385 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1388 value_fetch_lazy (src
);
1390 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1394 value_lazy (const struct value
*value
)
1400 set_value_lazy (struct value
*value
, int val
)
1406 value_stack (const struct value
*value
)
1408 return value
->stack
;
1412 set_value_stack (struct value
*value
, int val
)
1418 value_contents (struct value
*value
)
1420 const gdb_byte
*result
= value_contents_writeable (value
);
1421 require_not_optimized_out (value
);
1422 require_available (value
);
1427 value_contents_writeable (struct value
*value
)
1430 value_fetch_lazy (value
);
1431 return value_contents_raw (value
);
1435 value_optimized_out (struct value
*value
)
1437 /* We can only know if a value is optimized out once we have tried to
1439 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1443 value_fetch_lazy (value
);
1445 CATCH (ex
, RETURN_MASK_ERROR
)
1447 /* Fall back to checking value->optimized_out. */
1452 return !VEC_empty (range_s
, value
->optimized_out
);
1455 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1456 the following LENGTH bytes. */
1459 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1461 mark_value_bits_optimized_out (value
,
1462 offset
* TARGET_CHAR_BIT
,
1463 length
* TARGET_CHAR_BIT
);
1469 mark_value_bits_optimized_out (struct value
*value
,
1470 LONGEST offset
, LONGEST length
)
1472 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1476 value_bits_synthetic_pointer (const struct value
*value
,
1477 LONGEST offset
, LONGEST length
)
1479 if (value
->lval
!= lval_computed
1480 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1482 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1488 value_embedded_offset (const struct value
*value
)
1490 return value
->embedded_offset
;
1494 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1496 value
->embedded_offset
= val
;
1500 value_pointed_to_offset (const struct value
*value
)
1502 return value
->pointed_to_offset
;
1506 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1508 value
->pointed_to_offset
= val
;
1511 const struct lval_funcs
*
1512 value_computed_funcs (const struct value
*v
)
1514 gdb_assert (value_lval_const (v
) == lval_computed
);
1516 return v
->location
.computed
.funcs
;
1520 value_computed_closure (const struct value
*v
)
1522 gdb_assert (v
->lval
== lval_computed
);
1524 return v
->location
.computed
.closure
;
1528 deprecated_value_lval_hack (struct value
*value
)
1530 return &value
->lval
;
1534 value_lval_const (const struct value
*value
)
1540 value_address (const struct value
*value
)
1542 if (value
->lval
!= lval_memory
)
1544 if (value
->parent
!= NULL
)
1545 return value_address (value
->parent
) + value
->offset
;
1546 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1548 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1549 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1552 return value
->location
.address
+ value
->offset
;
1556 value_raw_address (const struct value
*value
)
1558 if (value
->lval
!= lval_memory
)
1560 return value
->location
.address
;
1564 set_value_address (struct value
*value
, CORE_ADDR addr
)
1566 gdb_assert (value
->lval
== lval_memory
);
1567 value
->location
.address
= addr
;
1570 struct internalvar
**
1571 deprecated_value_internalvar_hack (struct value
*value
)
1573 return &value
->location
.internalvar
;
1577 deprecated_value_next_frame_id_hack (struct value
*value
)
1579 gdb_assert (value
->lval
== lval_register
);
1580 return &value
->location
.reg
.next_frame_id
;
1584 deprecated_value_regnum_hack (struct value
*value
)
1586 gdb_assert (value
->lval
== lval_register
);
1587 return &value
->location
.reg
.regnum
;
1591 deprecated_value_modifiable (const struct value
*value
)
1593 return value
->modifiable
;
1596 /* Return a mark in the value chain. All values allocated after the
1597 mark is obtained (except for those released) are subject to being freed
1598 if a subsequent value_free_to_mark is passed the mark. */
1605 /* Take a reference to VAL. VAL will not be deallocated until all
1606 references are released. */
1609 value_incref (struct value
*val
)
1611 val
->reference_count
++;
1614 /* Release a reference to VAL, which was acquired with value_incref.
1615 This function is also called to deallocate values from the value
1619 value_free (struct value
*val
)
1623 gdb_assert (val
->reference_count
> 0);
1624 val
->reference_count
--;
1625 if (val
->reference_count
> 0)
1628 /* If there's an associated parent value, drop our reference to
1630 if (val
->parent
!= NULL
)
1631 value_free (val
->parent
);
1633 if (VALUE_LVAL (val
) == lval_computed
)
1635 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1637 if (funcs
->free_closure
)
1638 funcs
->free_closure (val
);
1640 else if (VALUE_LVAL (val
) == lval_xcallable
)
1641 free_xmethod_worker (val
->location
.xm_worker
);
1643 xfree (val
->contents
);
1644 VEC_free (range_s
, val
->unavailable
);
1649 /* Free all values allocated since MARK was obtained by value_mark
1650 (except for those released). */
1652 value_free_to_mark (const struct value
*mark
)
1657 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1666 /* Free all the values that have been allocated (except for those released).
1667 Call after each command, successful or not.
1668 In practice this is called before each command, which is sufficient. */
1671 free_all_values (void)
1676 for (val
= all_values
; val
; val
= next
)
1686 /* Frees all the elements in a chain of values. */
1689 free_value_chain (struct value
*v
)
1695 next
= value_next (v
);
1700 /* Remove VAL from the chain all_values
1701 so it will not be freed automatically. */
1704 release_value (struct value
*val
)
1708 if (all_values
== val
)
1710 all_values
= val
->next
;
1716 for (v
= all_values
; v
; v
= v
->next
)
1720 v
->next
= val
->next
;
1728 /* If the value is not already released, release it.
1729 If the value is already released, increment its reference count.
1730 That is, this function ensures that the value is released from the
1731 value chain and that the caller owns a reference to it. */
1734 release_value_or_incref (struct value
*val
)
1739 release_value (val
);
1742 /* Release all values up to mark */
1744 value_release_to_mark (const struct value
*mark
)
1749 for (val
= next
= all_values
; next
; next
= next
->next
)
1751 if (next
->next
== mark
)
1753 all_values
= next
->next
;
1763 /* Return a copy of the value ARG.
1764 It contains the same contents, for same memory address,
1765 but it's a different block of storage. */
1768 value_copy (struct value
*arg
)
1770 struct type
*encl_type
= value_enclosing_type (arg
);
1773 if (value_lazy (arg
))
1774 val
= allocate_value_lazy (encl_type
);
1776 val
= allocate_value (encl_type
);
1777 val
->type
= arg
->type
;
1778 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1779 val
->location
= arg
->location
;
1780 val
->offset
= arg
->offset
;
1781 val
->bitpos
= arg
->bitpos
;
1782 val
->bitsize
= arg
->bitsize
;
1783 val
->lazy
= arg
->lazy
;
1784 val
->embedded_offset
= value_embedded_offset (arg
);
1785 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1786 val
->modifiable
= arg
->modifiable
;
1787 if (!value_lazy (val
))
1789 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1790 TYPE_LENGTH (value_enclosing_type (arg
)));
1793 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1794 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1795 set_value_parent (val
, arg
->parent
);
1796 if (VALUE_LVAL (val
) == lval_computed
)
1798 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1800 if (funcs
->copy_closure
)
1801 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1806 /* Return a "const" and/or "volatile" qualified version of the value V.
1807 If CNST is true, then the returned value will be qualified with
1809 if VOLTL is true, then the returned value will be qualified with
1813 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1815 struct type
*val_type
= value_type (v
);
1816 struct type
*enclosing_type
= value_enclosing_type (v
);
1817 struct value
*cv_val
= value_copy (v
);
1819 deprecated_set_value_type (cv_val
,
1820 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1821 set_value_enclosing_type (cv_val
,
1822 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1827 /* Return a version of ARG that is non-lvalue. */
1830 value_non_lval (struct value
*arg
)
1832 if (VALUE_LVAL (arg
) != not_lval
)
1834 struct type
*enc_type
= value_enclosing_type (arg
);
1835 struct value
*val
= allocate_value (enc_type
);
1837 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1838 TYPE_LENGTH (enc_type
));
1839 val
->type
= arg
->type
;
1840 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1841 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1847 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1850 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1852 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1854 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1855 v
->lval
= lval_memory
;
1856 v
->location
.address
= addr
;
1860 set_value_component_location (struct value
*component
,
1861 const struct value
*whole
)
1865 gdb_assert (whole
->lval
!= lval_xcallable
);
1867 if (whole
->lval
== lval_internalvar
)
1868 VALUE_LVAL (component
) = lval_internalvar_component
;
1870 VALUE_LVAL (component
) = whole
->lval
;
1872 component
->location
= whole
->location
;
1873 if (whole
->lval
== lval_computed
)
1875 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1877 if (funcs
->copy_closure
)
1878 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1881 /* If type has a dynamic resolved location property
1882 update it's value address. */
1883 type
= value_type (whole
);
1884 if (NULL
!= TYPE_DATA_LOCATION (type
)
1885 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1886 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1889 /* Access to the value history. */
1891 /* Record a new value in the value history.
1892 Returns the absolute history index of the entry. */
1895 record_latest_value (struct value
*val
)
1899 /* We don't want this value to have anything to do with the inferior anymore.
1900 In particular, "set $1 = 50" should not affect the variable from which
1901 the value was taken, and fast watchpoints should be able to assume that
1902 a value on the value history never changes. */
1903 if (value_lazy (val
))
1904 value_fetch_lazy (val
);
1905 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1906 from. This is a bit dubious, because then *&$1 does not just return $1
1907 but the current contents of that location. c'est la vie... */
1908 val
->modifiable
= 0;
1910 /* The value may have already been released, in which case we're adding a
1911 new reference for its entry in the history. That is why we call
1912 release_value_or_incref here instead of release_value. */
1913 release_value_or_incref (val
);
1915 /* Here we treat value_history_count as origin-zero
1916 and applying to the value being stored now. */
1918 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1921 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1923 newobj
->next
= value_history_chain
;
1924 value_history_chain
= newobj
;
1927 value_history_chain
->values
[i
] = val
;
1929 /* Now we regard value_history_count as origin-one
1930 and applying to the value just stored. */
1932 return ++value_history_count
;
1935 /* Return a copy of the value in the history with sequence number NUM. */
1938 access_value_history (int num
)
1940 struct value_history_chunk
*chunk
;
1945 absnum
+= value_history_count
;
1950 error (_("The history is empty."));
1952 error (_("There is only one value in the history."));
1954 error (_("History does not go back to $$%d."), -num
);
1956 if (absnum
> value_history_count
)
1957 error (_("History has not yet reached $%d."), absnum
);
1961 /* Now absnum is always absolute and origin zero. */
1963 chunk
= value_history_chain
;
1964 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1965 - absnum
/ VALUE_HISTORY_CHUNK
;
1967 chunk
= chunk
->next
;
1969 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1973 show_values (char *num_exp
, int from_tty
)
1981 /* "show values +" should print from the stored position.
1982 "show values <exp>" should print around value number <exp>. */
1983 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1984 num
= parse_and_eval_long (num_exp
) - 5;
1988 /* "show values" means print the last 10 values. */
1989 num
= value_history_count
- 9;
1995 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1997 struct value_print_options opts
;
1999 val
= access_value_history (i
);
2000 printf_filtered (("$%d = "), i
);
2001 get_user_print_options (&opts
);
2002 value_print (val
, gdb_stdout
, &opts
);
2003 printf_filtered (("\n"));
2006 /* The next "show values +" should start after what we just printed. */
2009 /* Hitting just return after this command should do the same thing as
2010 "show values +". If num_exp is null, this is unnecessary, since
2011 "show values +" is not useful after "show values". */
2012 if (from_tty
&& num_exp
)
2019 enum internalvar_kind
2021 /* The internal variable is empty. */
2024 /* The value of the internal variable is provided directly as
2025 a GDB value object. */
2028 /* A fresh value is computed via a call-back routine on every
2029 access to the internal variable. */
2030 INTERNALVAR_MAKE_VALUE
,
2032 /* The internal variable holds a GDB internal convenience function. */
2033 INTERNALVAR_FUNCTION
,
2035 /* The variable holds an integer value. */
2036 INTERNALVAR_INTEGER
,
2038 /* The variable holds a GDB-provided string. */
2042 union internalvar_data
2044 /* A value object used with INTERNALVAR_VALUE. */
2045 struct value
*value
;
2047 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2050 /* The functions to call. */
2051 const struct internalvar_funcs
*functions
;
2053 /* The function's user-data. */
2057 /* The internal function used with INTERNALVAR_FUNCTION. */
2060 struct internal_function
*function
;
2061 /* True if this is the canonical name for the function. */
2065 /* An integer value used with INTERNALVAR_INTEGER. */
2068 /* If type is non-NULL, it will be used as the type to generate
2069 a value for this internal variable. If type is NULL, a default
2070 integer type for the architecture is used. */
2075 /* A string value used with INTERNALVAR_STRING. */
2079 /* Internal variables. These are variables within the debugger
2080 that hold values assigned by debugger commands.
2081 The user refers to them with a '$' prefix
2082 that does not appear in the variable names stored internally. */
2086 struct internalvar
*next
;
2089 /* We support various different kinds of content of an internal variable.
2090 enum internalvar_kind specifies the kind, and union internalvar_data
2091 provides the data associated with this particular kind. */
2093 enum internalvar_kind kind
;
2095 union internalvar_data u
;
2098 static struct internalvar
*internalvars
;
2100 /* If the variable does not already exist create it and give it the
2101 value given. If no value is given then the default is zero. */
2103 init_if_undefined_command (char* args
, int from_tty
)
2105 struct internalvar
* intvar
;
2107 /* Parse the expression - this is taken from set_command(). */
2108 expression_up expr
= parse_expression (args
);
2110 /* Validate the expression.
2111 Was the expression an assignment?
2112 Or even an expression at all? */
2113 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2114 error (_("Init-if-undefined requires an assignment expression."));
2116 /* Extract the variable from the parsed expression.
2117 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2118 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2119 error (_("The first parameter to init-if-undefined "
2120 "should be a GDB variable."));
2121 intvar
= expr
->elts
[2].internalvar
;
2123 /* Only evaluate the expression if the lvalue is void.
2124 This may still fail if the expresssion is invalid. */
2125 if (intvar
->kind
== INTERNALVAR_VOID
)
2126 evaluate_expression (expr
.get ());
2130 /* Look up an internal variable with name NAME. NAME should not
2131 normally include a dollar sign.
2133 If the specified internal variable does not exist,
2134 the return value is NULL. */
2136 struct internalvar
*
2137 lookup_only_internalvar (const char *name
)
2139 struct internalvar
*var
;
2141 for (var
= internalvars
; var
; var
= var
->next
)
2142 if (strcmp (var
->name
, name
) == 0)
2148 /* Complete NAME by comparing it to the names of internal variables.
2149 Returns a vector of newly allocated strings, or NULL if no matches
2153 complete_internalvar (const char *name
)
2155 VEC (char_ptr
) *result
= NULL
;
2156 struct internalvar
*var
;
2159 len
= strlen (name
);
2161 for (var
= internalvars
; var
; var
= var
->next
)
2162 if (strncmp (var
->name
, name
, len
) == 0)
2164 char *r
= xstrdup (var
->name
);
2166 VEC_safe_push (char_ptr
, result
, r
);
2172 /* Create an internal variable with name NAME and with a void value.
2173 NAME should not normally include a dollar sign. */
2175 struct internalvar
*
2176 create_internalvar (const char *name
)
2178 struct internalvar
*var
= XNEW (struct internalvar
);
2180 var
->name
= concat (name
, (char *)NULL
);
2181 var
->kind
= INTERNALVAR_VOID
;
2182 var
->next
= internalvars
;
2187 /* Create an internal variable with name NAME and register FUN as the
2188 function that value_of_internalvar uses to create a value whenever
2189 this variable is referenced. NAME should not normally include a
2190 dollar sign. DATA is passed uninterpreted to FUN when it is
2191 called. CLEANUP, if not NULL, is called when the internal variable
2192 is destroyed. It is passed DATA as its only argument. */
2194 struct internalvar
*
2195 create_internalvar_type_lazy (const char *name
,
2196 const struct internalvar_funcs
*funcs
,
2199 struct internalvar
*var
= create_internalvar (name
);
2201 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2202 var
->u
.make_value
.functions
= funcs
;
2203 var
->u
.make_value
.data
= data
;
2207 /* See documentation in value.h. */
2210 compile_internalvar_to_ax (struct internalvar
*var
,
2211 struct agent_expr
*expr
,
2212 struct axs_value
*value
)
2214 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2215 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2218 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2219 var
->u
.make_value
.data
);
2223 /* Look up an internal variable with name NAME. NAME should not
2224 normally include a dollar sign.
2226 If the specified internal variable does not exist,
2227 one is created, with a void value. */
2229 struct internalvar
*
2230 lookup_internalvar (const char *name
)
2232 struct internalvar
*var
;
2234 var
= lookup_only_internalvar (name
);
2238 return create_internalvar (name
);
2241 /* Return current value of internal variable VAR. For variables that
2242 are not inherently typed, use a value type appropriate for GDBARCH. */
2245 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2248 struct trace_state_variable
*tsv
;
2250 /* If there is a trace state variable of the same name, assume that
2251 is what we really want to see. */
2252 tsv
= find_trace_state_variable (var
->name
);
2255 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2257 if (tsv
->value_known
)
2258 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2261 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2267 case INTERNALVAR_VOID
:
2268 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2271 case INTERNALVAR_FUNCTION
:
2272 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2275 case INTERNALVAR_INTEGER
:
2276 if (!var
->u
.integer
.type
)
2277 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2278 var
->u
.integer
.val
);
2280 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2283 case INTERNALVAR_STRING
:
2284 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2285 builtin_type (gdbarch
)->builtin_char
);
2288 case INTERNALVAR_VALUE
:
2289 val
= value_copy (var
->u
.value
);
2290 if (value_lazy (val
))
2291 value_fetch_lazy (val
);
2294 case INTERNALVAR_MAKE_VALUE
:
2295 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2296 var
->u
.make_value
.data
);
2300 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2303 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2304 on this value go back to affect the original internal variable.
2306 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2307 no underlying modifyable state in the internal variable.
2309 Likewise, if the variable's value is a computed lvalue, we want
2310 references to it to produce another computed lvalue, where
2311 references and assignments actually operate through the
2312 computed value's functions.
2314 This means that internal variables with computed values
2315 behave a little differently from other internal variables:
2316 assignments to them don't just replace the previous value
2317 altogether. At the moment, this seems like the behavior we
2320 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2321 && val
->lval
!= lval_computed
)
2323 VALUE_LVAL (val
) = lval_internalvar
;
2324 VALUE_INTERNALVAR (val
) = var
;
2331 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2333 if (var
->kind
== INTERNALVAR_INTEGER
)
2335 *result
= var
->u
.integer
.val
;
2339 if (var
->kind
== INTERNALVAR_VALUE
)
2341 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2343 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2345 *result
= value_as_long (var
->u
.value
);
2354 get_internalvar_function (struct internalvar
*var
,
2355 struct internal_function
**result
)
2359 case INTERNALVAR_FUNCTION
:
2360 *result
= var
->u
.fn
.function
;
2369 set_internalvar_component (struct internalvar
*var
,
2370 LONGEST offset
, LONGEST bitpos
,
2371 LONGEST bitsize
, struct value
*newval
)
2374 struct gdbarch
*arch
;
2379 case INTERNALVAR_VALUE
:
2380 addr
= value_contents_writeable (var
->u
.value
);
2381 arch
= get_value_arch (var
->u
.value
);
2382 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2385 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2386 value_as_long (newval
), bitpos
, bitsize
);
2388 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2389 TYPE_LENGTH (value_type (newval
)));
2393 /* We can never get a component of any other kind. */
2394 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2399 set_internalvar (struct internalvar
*var
, struct value
*val
)
2401 enum internalvar_kind new_kind
;
2402 union internalvar_data new_data
= { 0 };
2404 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2405 error (_("Cannot overwrite convenience function %s"), var
->name
);
2407 /* Prepare new contents. */
2408 switch (TYPE_CODE (check_typedef (value_type (val
))))
2410 case TYPE_CODE_VOID
:
2411 new_kind
= INTERNALVAR_VOID
;
2414 case TYPE_CODE_INTERNAL_FUNCTION
:
2415 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2416 new_kind
= INTERNALVAR_FUNCTION
;
2417 get_internalvar_function (VALUE_INTERNALVAR (val
),
2418 &new_data
.fn
.function
);
2419 /* Copies created here are never canonical. */
2423 new_kind
= INTERNALVAR_VALUE
;
2424 new_data
.value
= value_copy (val
);
2425 new_data
.value
->modifiable
= 1;
2427 /* Force the value to be fetched from the target now, to avoid problems
2428 later when this internalvar is referenced and the target is gone or
2430 if (value_lazy (new_data
.value
))
2431 value_fetch_lazy (new_data
.value
);
2433 /* Release the value from the value chain to prevent it from being
2434 deleted by free_all_values. From here on this function should not
2435 call error () until new_data is installed into the var->u to avoid
2437 release_value (new_data
.value
);
2439 /* Internal variables which are created from values with a dynamic
2440 location don't need the location property of the origin anymore.
2441 The resolved dynamic location is used prior then any other address
2442 when accessing the value.
2443 If we keep it, we would still refer to the origin value.
2444 Remove the location property in case it exist. */
2445 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2450 /* Clean up old contents. */
2451 clear_internalvar (var
);
2454 var
->kind
= new_kind
;
2456 /* End code which must not call error(). */
2460 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2462 /* Clean up old contents. */
2463 clear_internalvar (var
);
2465 var
->kind
= INTERNALVAR_INTEGER
;
2466 var
->u
.integer
.type
= NULL
;
2467 var
->u
.integer
.val
= l
;
2471 set_internalvar_string (struct internalvar
*var
, const char *string
)
2473 /* Clean up old contents. */
2474 clear_internalvar (var
);
2476 var
->kind
= INTERNALVAR_STRING
;
2477 var
->u
.string
= xstrdup (string
);
2481 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2483 /* Clean up old contents. */
2484 clear_internalvar (var
);
2486 var
->kind
= INTERNALVAR_FUNCTION
;
2487 var
->u
.fn
.function
= f
;
2488 var
->u
.fn
.canonical
= 1;
2489 /* Variables installed here are always the canonical version. */
2493 clear_internalvar (struct internalvar
*var
)
2495 /* Clean up old contents. */
2498 case INTERNALVAR_VALUE
:
2499 value_free (var
->u
.value
);
2502 case INTERNALVAR_STRING
:
2503 xfree (var
->u
.string
);
2506 case INTERNALVAR_MAKE_VALUE
:
2507 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2508 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2515 /* Reset to void kind. */
2516 var
->kind
= INTERNALVAR_VOID
;
2520 internalvar_name (const struct internalvar
*var
)
2525 static struct internal_function
*
2526 create_internal_function (const char *name
,
2527 internal_function_fn handler
, void *cookie
)
2529 struct internal_function
*ifn
= XNEW (struct internal_function
);
2531 ifn
->name
= xstrdup (name
);
2532 ifn
->handler
= handler
;
2533 ifn
->cookie
= cookie
;
2538 value_internal_function_name (struct value
*val
)
2540 struct internal_function
*ifn
;
2543 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2544 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2545 gdb_assert (result
);
2551 call_internal_function (struct gdbarch
*gdbarch
,
2552 const struct language_defn
*language
,
2553 struct value
*func
, int argc
, struct value
**argv
)
2555 struct internal_function
*ifn
;
2558 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2559 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2560 gdb_assert (result
);
2562 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2565 /* The 'function' command. This does nothing -- it is just a
2566 placeholder to let "help function NAME" work. This is also used as
2567 the implementation of the sub-command that is created when
2568 registering an internal function. */
2570 function_command (char *command
, int from_tty
)
2575 /* Clean up if an internal function's command is destroyed. */
2577 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2579 xfree ((char *) self
->name
);
2580 xfree ((char *) self
->doc
);
2583 /* Add a new internal function. NAME is the name of the function; DOC
2584 is a documentation string describing the function. HANDLER is
2585 called when the function is invoked. COOKIE is an arbitrary
2586 pointer which is passed to HANDLER and is intended for "user
2589 add_internal_function (const char *name
, const char *doc
,
2590 internal_function_fn handler
, void *cookie
)
2592 struct cmd_list_element
*cmd
;
2593 struct internal_function
*ifn
;
2594 struct internalvar
*var
= lookup_internalvar (name
);
2596 ifn
= create_internal_function (name
, handler
, cookie
);
2597 set_internalvar_function (var
, ifn
);
2599 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2601 cmd
->destroyer
= function_destroyer
;
2604 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2605 prevent cycles / duplicates. */
2608 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2609 htab_t copied_types
)
2611 if (TYPE_OBJFILE (value
->type
) == objfile
)
2612 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2614 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2615 value
->enclosing_type
= copy_type_recursive (objfile
,
2616 value
->enclosing_type
,
2620 /* Likewise for internal variable VAR. */
2623 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2624 htab_t copied_types
)
2628 case INTERNALVAR_INTEGER
:
2629 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2631 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2634 case INTERNALVAR_VALUE
:
2635 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2640 /* Update the internal variables and value history when OBJFILE is
2641 discarded; we must copy the types out of the objfile. New global types
2642 will be created for every convenience variable which currently points to
2643 this objfile's types, and the convenience variables will be adjusted to
2644 use the new global types. */
2647 preserve_values (struct objfile
*objfile
)
2649 htab_t copied_types
;
2650 struct value_history_chunk
*cur
;
2651 struct internalvar
*var
;
2654 /* Create the hash table. We allocate on the objfile's obstack, since
2655 it is soon to be deleted. */
2656 copied_types
= create_copied_types_hash (objfile
);
2658 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2659 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2661 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2663 for (var
= internalvars
; var
; var
= var
->next
)
2664 preserve_one_internalvar (var
, objfile
, copied_types
);
2666 preserve_ext_lang_values (objfile
, copied_types
);
2668 htab_delete (copied_types
);
2672 show_convenience (char *ignore
, int from_tty
)
2674 struct gdbarch
*gdbarch
= get_current_arch ();
2675 struct internalvar
*var
;
2677 struct value_print_options opts
;
2679 get_user_print_options (&opts
);
2680 for (var
= internalvars
; var
; var
= var
->next
)
2687 printf_filtered (("$%s = "), var
->name
);
2693 val
= value_of_internalvar (gdbarch
, var
);
2694 value_print (val
, gdb_stdout
, &opts
);
2696 CATCH (ex
, RETURN_MASK_ERROR
)
2698 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2702 printf_filtered (("\n"));
2706 /* This text does not mention convenience functions on purpose.
2707 The user can't create them except via Python, and if Python support
2708 is installed this message will never be printed ($_streq will
2710 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2711 "Convenience variables have "
2712 "names starting with \"$\";\n"
2713 "use \"set\" as in \"set "
2714 "$foo = 5\" to define them.\n"));
2718 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2721 value_of_xmethod (struct xmethod_worker
*worker
)
2723 if (worker
->value
== NULL
)
2727 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2728 v
->lval
= lval_xcallable
;
2729 v
->location
.xm_worker
= worker
;
2734 return worker
->value
;
2737 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2740 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2742 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2743 && method
->lval
== lval_xcallable
&& argc
> 0);
2745 return get_xmethod_result_type (method
->location
.xm_worker
,
2746 argv
[0], argv
+ 1, argc
- 1);
2749 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2752 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2754 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2755 && method
->lval
== lval_xcallable
&& argc
> 0);
2757 return invoke_xmethod (method
->location
.xm_worker
,
2758 argv
[0], argv
+ 1, argc
- 1);
2761 /* Extract a value as a C number (either long or double).
2762 Knows how to convert fixed values to double, or
2763 floating values to long.
2764 Does not deallocate the value. */
2767 value_as_long (struct value
*val
)
2769 /* This coerces arrays and functions, which is necessary (e.g.
2770 in disassemble_command). It also dereferences references, which
2771 I suspect is the most logical thing to do. */
2772 val
= coerce_array (val
);
2773 return unpack_long (value_type (val
), value_contents (val
));
2777 value_as_double (struct value
*val
)
2782 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2784 error (_("Invalid floating value found in program."));
2788 /* Extract a value as a C pointer. Does not deallocate the value.
2789 Note that val's type may not actually be a pointer; value_as_long
2790 handles all the cases. */
2792 value_as_address (struct value
*val
)
2794 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2796 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2797 whether we want this to be true eventually. */
2799 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2800 non-address (e.g. argument to "signal", "info break", etc.), or
2801 for pointers to char, in which the low bits *are* significant. */
2802 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2805 /* There are several targets (IA-64, PowerPC, and others) which
2806 don't represent pointers to functions as simply the address of
2807 the function's entry point. For example, on the IA-64, a
2808 function pointer points to a two-word descriptor, generated by
2809 the linker, which contains the function's entry point, and the
2810 value the IA-64 "global pointer" register should have --- to
2811 support position-independent code. The linker generates
2812 descriptors only for those functions whose addresses are taken.
2814 On such targets, it's difficult for GDB to convert an arbitrary
2815 function address into a function pointer; it has to either find
2816 an existing descriptor for that function, or call malloc and
2817 build its own. On some targets, it is impossible for GDB to
2818 build a descriptor at all: the descriptor must contain a jump
2819 instruction; data memory cannot be executed; and code memory
2822 Upon entry to this function, if VAL is a value of type `function'
2823 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2824 value_address (val) is the address of the function. This is what
2825 you'll get if you evaluate an expression like `main'. The call
2826 to COERCE_ARRAY below actually does all the usual unary
2827 conversions, which includes converting values of type `function'
2828 to `pointer to function'. This is the challenging conversion
2829 discussed above. Then, `unpack_long' will convert that pointer
2830 back into an address.
2832 So, suppose the user types `disassemble foo' on an architecture
2833 with a strange function pointer representation, on which GDB
2834 cannot build its own descriptors, and suppose further that `foo'
2835 has no linker-built descriptor. The address->pointer conversion
2836 will signal an error and prevent the command from running, even
2837 though the next step would have been to convert the pointer
2838 directly back into the same address.
2840 The following shortcut avoids this whole mess. If VAL is a
2841 function, just return its address directly. */
2842 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2843 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2844 return value_address (val
);
2846 val
= coerce_array (val
);
2848 /* Some architectures (e.g. Harvard), map instruction and data
2849 addresses onto a single large unified address space. For
2850 instance: An architecture may consider a large integer in the
2851 range 0x10000000 .. 0x1000ffff to already represent a data
2852 addresses (hence not need a pointer to address conversion) while
2853 a small integer would still need to be converted integer to
2854 pointer to address. Just assume such architectures handle all
2855 integer conversions in a single function. */
2859 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2860 must admonish GDB hackers to make sure its behavior matches the
2861 compiler's, whenever possible.
2863 In general, I think GDB should evaluate expressions the same way
2864 the compiler does. When the user copies an expression out of
2865 their source code and hands it to a `print' command, they should
2866 get the same value the compiler would have computed. Any
2867 deviation from this rule can cause major confusion and annoyance,
2868 and needs to be justified carefully. In other words, GDB doesn't
2869 really have the freedom to do these conversions in clever and
2872 AndrewC pointed out that users aren't complaining about how GDB
2873 casts integers to pointers; they are complaining that they can't
2874 take an address from a disassembly listing and give it to `x/i'.
2875 This is certainly important.
2877 Adding an architecture method like integer_to_address() certainly
2878 makes it possible for GDB to "get it right" in all circumstances
2879 --- the target has complete control over how things get done, so
2880 people can Do The Right Thing for their target without breaking
2881 anyone else. The standard doesn't specify how integers get
2882 converted to pointers; usually, the ABI doesn't either, but
2883 ABI-specific code is a more reasonable place to handle it. */
2885 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2886 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2887 && gdbarch_integer_to_address_p (gdbarch
))
2888 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2889 value_contents (val
));
2891 return unpack_long (value_type (val
), value_contents (val
));
2895 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2896 as a long, or as a double, assuming the raw data is described
2897 by type TYPE. Knows how to convert different sizes of values
2898 and can convert between fixed and floating point. We don't assume
2899 any alignment for the raw data. Return value is in host byte order.
2901 If you want functions and arrays to be coerced to pointers, and
2902 references to be dereferenced, call value_as_long() instead.
2904 C++: It is assumed that the front-end has taken care of
2905 all matters concerning pointers to members. A pointer
2906 to member which reaches here is considered to be equivalent
2907 to an INT (or some size). After all, it is only an offset. */
2910 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2912 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2913 enum type_code code
= TYPE_CODE (type
);
2914 int len
= TYPE_LENGTH (type
);
2915 int nosign
= TYPE_UNSIGNED (type
);
2919 case TYPE_CODE_TYPEDEF
:
2920 return unpack_long (check_typedef (type
), valaddr
);
2921 case TYPE_CODE_ENUM
:
2922 case TYPE_CODE_FLAGS
:
2923 case TYPE_CODE_BOOL
:
2925 case TYPE_CODE_CHAR
:
2926 case TYPE_CODE_RANGE
:
2927 case TYPE_CODE_MEMBERPTR
:
2929 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2931 return extract_signed_integer (valaddr
, len
, byte_order
);
2934 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2936 case TYPE_CODE_DECFLOAT
:
2937 /* libdecnumber has a function to convert from decimal to integer, but
2938 it doesn't work when the decimal number has a fractional part. */
2939 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2943 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2944 whether we want this to be true eventually. */
2945 return extract_typed_address (valaddr
, type
);
2948 error (_("Value can't be converted to integer."));
2950 return 0; /* Placate lint. */
2953 /* Return a double value from the specified type and address.
2954 INVP points to an int which is set to 0 for valid value,
2955 1 for invalid value (bad float format). In either case,
2956 the returned double is OK to use. Argument is in target
2957 format, result is in host format. */
2960 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2962 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2963 enum type_code code
;
2967 *invp
= 0; /* Assume valid. */
2968 type
= check_typedef (type
);
2969 code
= TYPE_CODE (type
);
2970 len
= TYPE_LENGTH (type
);
2971 nosign
= TYPE_UNSIGNED (type
);
2972 if (code
== TYPE_CODE_FLT
)
2974 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2975 floating-point value was valid (using the macro
2976 INVALID_FLOAT). That test/macro have been removed.
2978 It turns out that only the VAX defined this macro and then
2979 only in a non-portable way. Fixing the portability problem
2980 wouldn't help since the VAX floating-point code is also badly
2981 bit-rotten. The target needs to add definitions for the
2982 methods gdbarch_float_format and gdbarch_double_format - these
2983 exactly describe the target floating-point format. The
2984 problem here is that the corresponding floatformat_vax_f and
2985 floatformat_vax_d values these methods should be set to are
2986 also not defined either. Oops!
2988 Hopefully someone will add both the missing floatformat
2989 definitions and the new cases for floatformat_is_valid (). */
2991 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2997 return extract_typed_floating (valaddr
, type
);
2999 else if (code
== TYPE_CODE_DECFLOAT
)
3000 return decimal_to_doublest (valaddr
, len
, byte_order
);
3003 /* Unsigned -- be sure we compensate for signed LONGEST. */
3004 return (ULONGEST
) unpack_long (type
, valaddr
);
3008 /* Signed -- we are OK with unpack_long. */
3009 return unpack_long (type
, valaddr
);
3013 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3014 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3015 We don't assume any alignment for the raw data. Return value is in
3018 If you want functions and arrays to be coerced to pointers, and
3019 references to be dereferenced, call value_as_address() instead.
3021 C++: It is assumed that the front-end has taken care of
3022 all matters concerning pointers to members. A pointer
3023 to member which reaches here is considered to be equivalent
3024 to an INT (or some size). After all, it is only an offset. */
3027 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3029 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3030 whether we want this to be true eventually. */
3031 return unpack_long (type
, valaddr
);
3035 /* Get the value of the FIELDNO'th field (which must be static) of
3039 value_static_field (struct type
*type
, int fieldno
)
3041 struct value
*retval
;
3043 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3045 case FIELD_LOC_KIND_PHYSADDR
:
3046 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3047 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3049 case FIELD_LOC_KIND_PHYSNAME
:
3051 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3052 /* TYPE_FIELD_NAME (type, fieldno); */
3053 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3055 if (sym
.symbol
== NULL
)
3057 /* With some compilers, e.g. HP aCC, static data members are
3058 reported as non-debuggable symbols. */
3059 struct bound_minimal_symbol msym
3060 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3063 return allocate_optimized_out_value (type
);
3066 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3067 BMSYMBOL_VALUE_ADDRESS (msym
));
3071 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3075 gdb_assert_not_reached ("unexpected field location kind");
3081 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3082 You have to be careful here, since the size of the data area for the value
3083 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3084 than the old enclosing type, you have to allocate more space for the
3088 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3090 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3092 check_type_length_before_alloc (new_encl_type
);
3094 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3097 val
->enclosing_type
= new_encl_type
;
3100 /* Given a value ARG1 (offset by OFFSET bytes)
3101 of a struct or union type ARG_TYPE,
3102 extract and return the value of one of its (non-static) fields.
3103 FIELDNO says which field. */
3106 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3107 int fieldno
, struct type
*arg_type
)
3111 struct gdbarch
*arch
= get_value_arch (arg1
);
3112 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3114 arg_type
= check_typedef (arg_type
);
3115 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3117 /* Call check_typedef on our type to make sure that, if TYPE
3118 is a TYPE_CODE_TYPEDEF, its length is set to the length
3119 of the target type instead of zero. However, we do not
3120 replace the typedef type by the target type, because we want
3121 to keep the typedef in order to be able to print the type
3122 description correctly. */
3123 check_typedef (type
);
3125 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3127 /* Handle packed fields.
3129 Create a new value for the bitfield, with bitpos and bitsize
3130 set. If possible, arrange offset and bitpos so that we can
3131 do a single aligned read of the size of the containing type.
3132 Otherwise, adjust offset to the byte containing the first
3133 bit. Assume that the address, offset, and embedded offset
3134 are sufficiently aligned. */
3136 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3137 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3139 v
= allocate_value_lazy (type
);
3140 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3141 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3142 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3143 v
->bitpos
= bitpos
% container_bitsize
;
3145 v
->bitpos
= bitpos
% 8;
3146 v
->offset
= (value_embedded_offset (arg1
)
3148 + (bitpos
- v
->bitpos
) / 8);
3149 set_value_parent (v
, arg1
);
3150 if (!value_lazy (arg1
))
3151 value_fetch_lazy (v
);
3153 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3155 /* This field is actually a base subobject, so preserve the
3156 entire object's contents for later references to virtual
3160 /* Lazy register values with offsets are not supported. */
3161 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3162 value_fetch_lazy (arg1
);
3164 /* We special case virtual inheritance here because this
3165 requires access to the contents, which we would rather avoid
3166 for references to ordinary fields of unavailable values. */
3167 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3168 boffset
= baseclass_offset (arg_type
, fieldno
,
3169 value_contents (arg1
),
3170 value_embedded_offset (arg1
),
3171 value_address (arg1
),
3174 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3176 if (value_lazy (arg1
))
3177 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3180 v
= allocate_value (value_enclosing_type (arg1
));
3181 value_contents_copy_raw (v
, 0, arg1
, 0,
3182 TYPE_LENGTH (value_enclosing_type (arg1
)));
3185 v
->offset
= value_offset (arg1
);
3186 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3188 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3190 /* Field is a dynamic data member. */
3192 gdb_assert (0 == offset
);
3193 /* We expect an already resolved data location. */
3194 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3195 /* For dynamic data types defer memory allocation
3196 until we actual access the value. */
3197 v
= allocate_value_lazy (type
);
3201 /* Plain old data member */
3202 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3203 / (HOST_CHAR_BIT
* unit_size
));
3205 /* Lazy register values with offsets are not supported. */
3206 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3207 value_fetch_lazy (arg1
);
3209 if (value_lazy (arg1
))
3210 v
= allocate_value_lazy (type
);
3213 v
= allocate_value (type
);
3214 value_contents_copy_raw (v
, value_embedded_offset (v
),
3215 arg1
, value_embedded_offset (arg1
) + offset
,
3216 type_length_units (type
));
3218 v
->offset
= (value_offset (arg1
) + offset
3219 + value_embedded_offset (arg1
));
3221 set_value_component_location (v
, arg1
);
3225 /* Given a value ARG1 of a struct or union type,
3226 extract and return the value of one of its (non-static) fields.
3227 FIELDNO says which field. */
3230 value_field (struct value
*arg1
, int fieldno
)
3232 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3235 /* Return a non-virtual function as a value.
3236 F is the list of member functions which contains the desired method.
3237 J is an index into F which provides the desired method.
3239 We only use the symbol for its address, so be happy with either a
3240 full symbol or a minimal symbol. */
3243 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3244 int j
, struct type
*type
,
3248 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3249 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3251 struct bound_minimal_symbol msym
;
3253 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3256 memset (&msym
, 0, sizeof (msym
));
3260 gdb_assert (sym
== NULL
);
3261 msym
= lookup_bound_minimal_symbol (physname
);
3262 if (msym
.minsym
== NULL
)
3266 v
= allocate_value (ftype
);
3267 VALUE_LVAL (v
) = lval_memory
;
3270 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3274 /* The minimal symbol might point to a function descriptor;
3275 resolve it to the actual code address instead. */
3276 struct objfile
*objfile
= msym
.objfile
;
3277 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3279 set_value_address (v
,
3280 gdbarch_convert_from_func_ptr_addr
3281 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3286 if (type
!= value_type (*arg1p
))
3287 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3288 value_addr (*arg1p
)));
3290 /* Move the `this' pointer according to the offset.
3291 VALUE_OFFSET (*arg1p) += offset; */
3299 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3300 VALADDR, and store the result in *RESULT.
3301 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3303 Extracting bits depends on endianness of the machine. Compute the
3304 number of least significant bits to discard. For big endian machines,
3305 we compute the total number of bits in the anonymous object, subtract
3306 off the bit count from the MSB of the object to the MSB of the
3307 bitfield, then the size of the bitfield, which leaves the LSB discard
3308 count. For little endian machines, the discard count is simply the
3309 number of bits from the LSB of the anonymous object to the LSB of the
3312 If the field is signed, we also do sign extension. */
3315 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3316 LONGEST bitpos
, LONGEST bitsize
)
3318 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3323 LONGEST read_offset
;
3325 /* Read the minimum number of bytes required; there may not be
3326 enough bytes to read an entire ULONGEST. */
3327 field_type
= check_typedef (field_type
);
3329 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3331 bytes_read
= TYPE_LENGTH (field_type
);
3333 read_offset
= bitpos
/ 8;
3335 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3336 bytes_read
, byte_order
);
3338 /* Extract bits. See comment above. */
3340 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3341 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3343 lsbcount
= (bitpos
% 8);
3346 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3347 If the field is signed, and is negative, then sign extend. */
3349 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3351 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3353 if (!TYPE_UNSIGNED (field_type
))
3355 if (val
& (valmask
^ (valmask
>> 1)))
3365 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3366 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3367 ORIGINAL_VALUE, which must not be NULL. See
3368 unpack_value_bits_as_long for more details. */
3371 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3372 LONGEST embedded_offset
, int fieldno
,
3373 const struct value
*val
, LONGEST
*result
)
3375 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3376 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3377 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3380 gdb_assert (val
!= NULL
);
3382 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3383 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3384 || !value_bits_available (val
, bit_offset
, bitsize
))
3387 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3392 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3393 object at VALADDR. See unpack_bits_as_long for more details. */
3396 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3398 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3399 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3400 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3402 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3405 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3406 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3407 the contents in DEST_VAL, zero or sign extending if the type of
3408 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3409 VAL. If the VAL's contents required to extract the bitfield from
3410 are unavailable/optimized out, DEST_VAL is correspondingly
3411 marked unavailable/optimized out. */
3414 unpack_value_bitfield (struct value
*dest_val
,
3415 LONGEST bitpos
, LONGEST bitsize
,
3416 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3417 const struct value
*val
)
3419 enum bfd_endian byte_order
;
3422 struct type
*field_type
= value_type (dest_val
);
3424 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3426 /* First, unpack and sign extend the bitfield as if it was wholly
3427 valid. Optimized out/unavailable bits are read as zero, but
3428 that's OK, as they'll end up marked below. If the VAL is
3429 wholly-invalid we may have skipped allocating its contents,
3430 though. See allocate_optimized_out_value. */
3431 if (valaddr
!= NULL
)
3435 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3437 store_signed_integer (value_contents_raw (dest_val
),
3438 TYPE_LENGTH (field_type
), byte_order
, num
);
3441 /* Now copy the optimized out / unavailability ranges to the right
3443 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3444 if (byte_order
== BFD_ENDIAN_BIG
)
3445 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3448 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3449 val
, src_bit_offset
, bitsize
);
3452 /* Return a new value with type TYPE, which is FIELDNO field of the
3453 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3454 of VAL. If the VAL's contents required to extract the bitfield
3455 from are unavailable/optimized out, the new value is
3456 correspondingly marked unavailable/optimized out. */
3459 value_field_bitfield (struct type
*type
, int fieldno
,
3460 const gdb_byte
*valaddr
,
3461 LONGEST embedded_offset
, const struct value
*val
)
3463 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3464 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3465 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3467 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3468 valaddr
, embedded_offset
, val
);
3473 /* Modify the value of a bitfield. ADDR points to a block of memory in
3474 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3475 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3476 indicate which bits (in target bit order) comprise the bitfield.
3477 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3478 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3481 modify_field (struct type
*type
, gdb_byte
*addr
,
3482 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3484 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3486 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3489 /* Normalize BITPOS. */
3493 /* If a negative fieldval fits in the field in question, chop
3494 off the sign extension bits. */
3495 if ((~fieldval
& ~(mask
>> 1)) == 0)
3498 /* Warn if value is too big to fit in the field in question. */
3499 if (0 != (fieldval
& ~mask
))
3501 /* FIXME: would like to include fieldval in the message, but
3502 we don't have a sprintf_longest. */
3503 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3505 /* Truncate it, otherwise adjoining fields may be corrupted. */
3509 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3510 false valgrind reports. */
3512 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3513 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3515 /* Shifting for bit field depends on endianness of the target machine. */
3516 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3517 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3519 oword
&= ~(mask
<< bitpos
);
3520 oword
|= fieldval
<< bitpos
;
3522 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3525 /* Pack NUM into BUF using a target format of TYPE. */
3528 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3530 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3533 type
= check_typedef (type
);
3534 len
= TYPE_LENGTH (type
);
3536 switch (TYPE_CODE (type
))
3539 case TYPE_CODE_CHAR
:
3540 case TYPE_CODE_ENUM
:
3541 case TYPE_CODE_FLAGS
:
3542 case TYPE_CODE_BOOL
:
3543 case TYPE_CODE_RANGE
:
3544 case TYPE_CODE_MEMBERPTR
:
3545 store_signed_integer (buf
, len
, byte_order
, num
);
3550 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3554 error (_("Unexpected type (%d) encountered for integer constant."),
3560 /* Pack NUM into BUF using a target format of TYPE. */
3563 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3566 enum bfd_endian byte_order
;
3568 type
= check_typedef (type
);
3569 len
= TYPE_LENGTH (type
);
3570 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3572 switch (TYPE_CODE (type
))
3575 case TYPE_CODE_CHAR
:
3576 case TYPE_CODE_ENUM
:
3577 case TYPE_CODE_FLAGS
:
3578 case TYPE_CODE_BOOL
:
3579 case TYPE_CODE_RANGE
:
3580 case TYPE_CODE_MEMBERPTR
:
3581 store_unsigned_integer (buf
, len
, byte_order
, num
);
3586 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3590 error (_("Unexpected type (%d) encountered "
3591 "for unsigned integer constant."),
3597 /* Convert C numbers into newly allocated values. */
3600 value_from_longest (struct type
*type
, LONGEST num
)
3602 struct value
*val
= allocate_value (type
);
3604 pack_long (value_contents_raw (val
), type
, num
);
3609 /* Convert C unsigned numbers into newly allocated values. */
3612 value_from_ulongest (struct type
*type
, ULONGEST num
)
3614 struct value
*val
= allocate_value (type
);
3616 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3622 /* Create a value representing a pointer of type TYPE to the address
3626 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3628 struct value
*val
= allocate_value (type
);
3630 store_typed_address (value_contents_raw (val
),
3631 check_typedef (type
), addr
);
3636 /* Create a value of type TYPE whose contents come from VALADDR, if it
3637 is non-null, and whose memory address (in the inferior) is
3638 ADDRESS. The type of the created value may differ from the passed
3639 type TYPE. Make sure to retrieve values new type after this call.
3640 Note that TYPE is not passed through resolve_dynamic_type; this is
3641 a special API intended for use only by Ada. */
3644 value_from_contents_and_address_unresolved (struct type
*type
,
3645 const gdb_byte
*valaddr
,
3650 if (valaddr
== NULL
)
3651 v
= allocate_value_lazy (type
);
3653 v
= value_from_contents (type
, valaddr
);
3654 VALUE_LVAL (v
) = lval_memory
;
3655 set_value_address (v
, address
);
3659 /* Create a value of type TYPE whose contents come from VALADDR, if it
3660 is non-null, and whose memory address (in the inferior) is
3661 ADDRESS. The type of the created value may differ from the passed
3662 type TYPE. Make sure to retrieve values new type after this call. */
3665 value_from_contents_and_address (struct type
*type
,
3666 const gdb_byte
*valaddr
,
3669 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3670 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3673 if (valaddr
== NULL
)
3674 v
= allocate_value_lazy (resolved_type
);
3676 v
= value_from_contents (resolved_type
, valaddr
);
3677 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3678 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3679 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3680 VALUE_LVAL (v
) = lval_memory
;
3681 set_value_address (v
, address
);
3685 /* Create a value of type TYPE holding the contents CONTENTS.
3686 The new value is `not_lval'. */
3689 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3691 struct value
*result
;
3693 result
= allocate_value (type
);
3694 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3699 value_from_double (struct type
*type
, DOUBLEST num
)
3701 struct value
*val
= allocate_value (type
);
3702 struct type
*base_type
= check_typedef (type
);
3703 enum type_code code
= TYPE_CODE (base_type
);
3705 if (code
== TYPE_CODE_FLT
)
3707 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3710 error (_("Unexpected type encountered for floating constant."));
3716 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3718 struct value
*val
= allocate_value (type
);
3720 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3724 /* Extract a value from the history file. Input will be of the form
3725 $digits or $$digits. See block comment above 'write_dollar_variable'
3729 value_from_history_ref (const char *h
, const char **endp
)
3741 /* Find length of numeral string. */
3742 for (; isdigit (h
[len
]); len
++)
3745 /* Make sure numeral string is not part of an identifier. */
3746 if (h
[len
] == '_' || isalpha (h
[len
]))
3749 /* Now collect the index value. */
3754 /* For some bizarre reason, "$$" is equivalent to "$$1",
3755 rather than to "$$0" as it ought to be! */
3763 index
= -strtol (&h
[2], &local_end
, 10);
3771 /* "$" is equivalent to "$0". */
3779 index
= strtol (&h
[1], &local_end
, 10);
3784 return access_value_history (index
);
3787 /* Get the component value (offset by OFFSET bytes) of a struct or
3788 union WHOLE. Component's type is TYPE. */
3791 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3795 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3796 v
= allocate_value_lazy (type
);
3799 v
= allocate_value (type
);
3800 value_contents_copy (v
, value_embedded_offset (v
),
3801 whole
, value_embedded_offset (whole
) + offset
,
3802 type_length_units (type
));
3804 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3805 set_value_component_location (v
, whole
);
3811 coerce_ref_if_computed (const struct value
*arg
)
3813 const struct lval_funcs
*funcs
;
3815 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3818 if (value_lval_const (arg
) != lval_computed
)
3821 funcs
= value_computed_funcs (arg
);
3822 if (funcs
->coerce_ref
== NULL
)
3825 return funcs
->coerce_ref (arg
);
3828 /* Look at value.h for description. */
3831 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3832 const struct type
*original_type
,
3833 const struct value
*original_value
)
3835 /* Re-adjust type. */
3836 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3838 /* Add embedding info. */
3839 set_value_enclosing_type (value
, enc_type
);
3840 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3842 /* We may be pointing to an object of some derived type. */
3843 return value_full_object (value
, NULL
, 0, 0, 0);
3847 coerce_ref (struct value
*arg
)
3849 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3850 struct value
*retval
;
3851 struct type
*enc_type
;
3853 retval
= coerce_ref_if_computed (arg
);
3857 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3860 enc_type
= check_typedef (value_enclosing_type (arg
));
3861 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3863 retval
= value_at_lazy (enc_type
,
3864 unpack_pointer (value_type (arg
),
3865 value_contents (arg
)));
3866 enc_type
= value_type (retval
);
3867 return readjust_indirect_value_type (retval
, enc_type
,
3868 value_type_arg_tmp
, arg
);
3872 coerce_array (struct value
*arg
)
3876 arg
= coerce_ref (arg
);
3877 type
= check_typedef (value_type (arg
));
3879 switch (TYPE_CODE (type
))
3881 case TYPE_CODE_ARRAY
:
3882 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3883 arg
= value_coerce_array (arg
);
3885 case TYPE_CODE_FUNC
:
3886 arg
= value_coerce_function (arg
);
3893 /* Return the return value convention that will be used for the
3896 enum return_value_convention
3897 struct_return_convention (struct gdbarch
*gdbarch
,
3898 struct value
*function
, struct type
*value_type
)
3900 enum type_code code
= TYPE_CODE (value_type
);
3902 if (code
== TYPE_CODE_ERROR
)
3903 error (_("Function return type unknown."));
3905 /* Probe the architecture for the return-value convention. */
3906 return gdbarch_return_value (gdbarch
, function
, value_type
,
3910 /* Return true if the function returning the specified type is using
3911 the convention of returning structures in memory (passing in the
3912 address as a hidden first parameter). */
3915 using_struct_return (struct gdbarch
*gdbarch
,
3916 struct value
*function
, struct type
*value_type
)
3918 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3919 /* A void return value is never in memory. See also corresponding
3920 code in "print_return_value". */
3923 return (struct_return_convention (gdbarch
, function
, value_type
)
3924 != RETURN_VALUE_REGISTER_CONVENTION
);
3927 /* Set the initialized field in a value struct. */
3930 set_value_initialized (struct value
*val
, int status
)
3932 val
->initialized
= status
;
3935 /* Return the initialized field in a value struct. */
3938 value_initialized (const struct value
*val
)
3940 return val
->initialized
;
3943 /* Load the actual content of a lazy value. Fetch the data from the
3944 user's process and clear the lazy flag to indicate that the data in
3945 the buffer is valid.
3947 If the value is zero-length, we avoid calling read_memory, which
3948 would abort. We mark the value as fetched anyway -- all 0 bytes of
3952 value_fetch_lazy (struct value
*val
)
3954 gdb_assert (value_lazy (val
));
3955 allocate_value_contents (val
);
3956 /* A value is either lazy, or fully fetched. The
3957 availability/validity is only established as we try to fetch a
3959 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3960 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3961 if (value_bitsize (val
))
3963 /* To read a lazy bitfield, read the entire enclosing value. This
3964 prevents reading the same block of (possibly volatile) memory once
3965 per bitfield. It would be even better to read only the containing
3966 word, but we have no way to record that just specific bits of a
3967 value have been fetched. */
3968 struct type
*type
= check_typedef (value_type (val
));
3969 struct value
*parent
= value_parent (val
);
3971 if (value_lazy (parent
))
3972 value_fetch_lazy (parent
);
3974 unpack_value_bitfield (val
,
3975 value_bitpos (val
), value_bitsize (val
),
3976 value_contents_for_printing (parent
),
3977 value_offset (val
), parent
);
3979 else if (VALUE_LVAL (val
) == lval_memory
)
3981 CORE_ADDR addr
= value_address (val
);
3982 struct type
*type
= check_typedef (value_enclosing_type (val
));
3984 if (TYPE_LENGTH (type
))
3985 read_value_memory (val
, 0, value_stack (val
),
3986 addr
, value_contents_all_raw (val
),
3987 type_length_units (type
));
3989 else if (VALUE_LVAL (val
) == lval_register
)
3991 struct frame_info
*next_frame
;
3993 struct type
*type
= check_typedef (value_type (val
));
3994 struct value
*new_val
= val
, *mark
= value_mark ();
3996 /* Offsets are not supported here; lazy register values must
3997 refer to the entire register. */
3998 gdb_assert (value_offset (val
) == 0);
4000 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
4002 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
4004 next_frame
= frame_find_by_id (next_frame_id
);
4005 regnum
= VALUE_REGNUM (new_val
);
4007 gdb_assert (next_frame
!= NULL
);
4009 /* Convertible register routines are used for multi-register
4010 values and for interpretation in different types
4011 (e.g. float or int from a double register). Lazy
4012 register values should have the register's natural type,
4013 so they do not apply. */
4014 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
4017 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
4018 Since a "->next" operation was performed when setting
4019 this field, we do not need to perform a "next" operation
4020 again when unwinding the register. That's why
4021 frame_unwind_register_value() is called here instead of
4022 get_frame_register_value(). */
4023 new_val
= frame_unwind_register_value (next_frame
, regnum
);
4025 /* If we get another lazy lval_register value, it means the
4026 register is found by reading it from NEXT_FRAME's next frame.
4027 frame_unwind_register_value should never return a value with
4028 the frame id pointing to NEXT_FRAME. If it does, it means we
4029 either have two consecutive frames with the same frame id
4030 in the frame chain, or some code is trying to unwind
4031 behind get_prev_frame's back (e.g., a frame unwind
4032 sniffer trying to unwind), bypassing its validations. In
4033 any case, it should always be an internal error to end up
4034 in this situation. */
4035 if (VALUE_LVAL (new_val
) == lval_register
4036 && value_lazy (new_val
)
4037 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
4038 internal_error (__FILE__
, __LINE__
,
4039 _("infinite loop while fetching a register"));
4042 /* If it's still lazy (for instance, a saved register on the
4043 stack), fetch it. */
4044 if (value_lazy (new_val
))
4045 value_fetch_lazy (new_val
);
4047 /* Copy the contents and the unavailability/optimized-out
4048 meta-data from NEW_VAL to VAL. */
4049 set_value_lazy (val
, 0);
4050 value_contents_copy (val
, value_embedded_offset (val
),
4051 new_val
, value_embedded_offset (new_val
),
4052 type_length_units (type
));
4056 struct gdbarch
*gdbarch
;
4057 struct frame_info
*frame
;
4058 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
4059 so that the frame level will be shown correctly. */
4060 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4061 regnum
= VALUE_REGNUM (val
);
4062 gdbarch
= get_frame_arch (frame
);
4064 fprintf_unfiltered (gdb_stdlog
,
4065 "{ value_fetch_lazy "
4066 "(frame=%d,regnum=%d(%s),...) ",
4067 frame_relative_level (frame
), regnum
,
4068 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4070 fprintf_unfiltered (gdb_stdlog
, "->");
4071 if (value_optimized_out (new_val
))
4073 fprintf_unfiltered (gdb_stdlog
, " ");
4074 val_print_optimized_out (new_val
, gdb_stdlog
);
4079 const gdb_byte
*buf
= value_contents (new_val
);
4081 if (VALUE_LVAL (new_val
) == lval_register
)
4082 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4083 VALUE_REGNUM (new_val
));
4084 else if (VALUE_LVAL (new_val
) == lval_memory
)
4085 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4087 value_address (new_val
)));
4089 fprintf_unfiltered (gdb_stdlog
, " computed");
4091 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4092 fprintf_unfiltered (gdb_stdlog
, "[");
4093 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4094 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4095 fprintf_unfiltered (gdb_stdlog
, "]");
4098 fprintf_unfiltered (gdb_stdlog
, " }\n");
4101 /* Dispose of the intermediate values. This prevents
4102 watchpoints from trying to watch the saved frame pointer. */
4103 value_free_to_mark (mark
);
4105 else if (VALUE_LVAL (val
) == lval_computed
4106 && value_computed_funcs (val
)->read
!= NULL
)
4107 value_computed_funcs (val
)->read (val
);
4109 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4111 set_value_lazy (val
, 0);
4114 /* Implementation of the convenience function $_isvoid. */
4116 static struct value
*
4117 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4118 const struct language_defn
*language
,
4119 void *cookie
, int argc
, struct value
**argv
)
4124 error (_("You must provide one argument for $_isvoid."));
4126 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4128 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4132 _initialize_values (void)
4134 add_cmd ("convenience", no_class
, show_convenience
, _("\
4135 Debugger convenience (\"$foo\") variables and functions.\n\
4136 Convenience variables are created when you assign them values;\n\
4137 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4139 A few convenience variables are given values automatically:\n\
4140 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4141 \"$__\" holds the contents of the last address examined with \"x\"."
4144 Convenience functions are defined via the Python API."
4147 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4149 add_cmd ("values", no_set_class
, show_values
, _("\
4150 Elements of value history around item number IDX (or last ten)."),
4153 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4154 Initialize a convenience variable if necessary.\n\
4155 init-if-undefined VARIABLE = EXPRESSION\n\
4156 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4157 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4158 VARIABLE is already initialized."));
4160 add_prefix_cmd ("function", no_class
, function_command
, _("\
4161 Placeholder command for showing help on convenience functions."),
4162 &functionlist
, "function ", 0, &cmdlist
);
4164 add_internal_function ("_isvoid", _("\
4165 Check whether an expression is void.\n\
4166 Usage: $_isvoid (expression)\n\
4167 Return 1 if the expression is void, zero otherwise."),
4168 isvoid_internal_fn
, NULL
);
4170 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4171 class_support
, &max_value_size
, _("\
4172 Set maximum sized value gdb will load from the inferior."), _("\
4173 Show maximum sized value gdb will load from the inferior."), _("\
4174 Use this to control the maximum size, in bytes, of a value that gdb\n\
4175 will load from the inferior. Setting this value to 'unlimited'\n\
4176 disables checking.\n\
4177 Setting this does not invalidate already allocated values, it only\n\
4178 prevents future values, larger than this size, from being allocated."),
4180 show_max_value_size
,
4181 &setlist
, &showlist
);