1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
37 #include "cli/cli-decode.h"
38 #include "extension.h"
40 #include "tracepoint.h"
42 #include "user-regs.h"
45 /* Prototypes for exported functions. */
47 void _initialize_values (void);
49 /* Definition of a user function. */
50 struct internal_function
52 /* The name of the function. It is a bit odd to have this in the
53 function itself -- the user might use a differently-named
54 convenience variable to hold the function. */
58 internal_function_fn handler
;
60 /* User data for the handler. */
64 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
68 /* Lowest offset in the range. */
71 /* Length of the range. */
75 typedef struct range range_s
;
79 /* Returns true if the ranges defined by [offset1, offset1+len1) and
80 [offset2, offset2+len2) overlap. */
83 ranges_overlap (LONGEST offset1
, LONGEST len1
,
84 LONGEST offset2
, LONGEST len2
)
88 l
= std::max (offset1
, offset2
);
89 h
= std::min (offset1
+ len1
, offset2
+ len2
);
93 /* Returns true if the first argument is strictly less than the
94 second, useful for VEC_lower_bound. We keep ranges sorted by
95 offset and coalesce overlapping and contiguous ranges, so this just
96 compares the starting offset. */
99 range_lessthan (const range_s
*r1
, const range_s
*r2
)
101 return r1
->offset
< r2
->offset
;
104 /* Returns true if RANGES contains any range that overlaps [OFFSET,
108 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
113 what
.offset
= offset
;
114 what
.length
= length
;
116 /* We keep ranges sorted by offset and coalesce overlapping and
117 contiguous ranges, so to check if a range list contains a given
118 range, we can do a binary search for the position the given range
119 would be inserted if we only considered the starting OFFSET of
120 ranges. We call that position I. Since we also have LENGTH to
121 care for (this is a range afterall), we need to check if the
122 _previous_ range overlaps the I range. E.g.,
126 |---| |---| |------| ... |--|
131 In the case above, the binary search would return `I=1', meaning,
132 this OFFSET should be inserted at position 1, and the current
133 position 1 should be pushed further (and before 2). But, `0'
136 Then we need to check if the I range overlaps the I range itself.
141 |---| |---| |-------| ... |--|
147 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
151 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
153 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
157 if (i
< VEC_length (range_s
, ranges
))
159 struct range
*r
= VEC_index (range_s
, ranges
, i
);
161 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
168 static struct cmd_list_element
*functionlist
;
170 /* Note that the fields in this structure are arranged to save a bit
175 /* Type of value; either not an lval, or one of the various
176 different possible kinds of lval. */
179 /* Is it modifiable? Only relevant if lval != not_lval. */
180 unsigned int modifiable
: 1;
182 /* If zero, contents of this value are in the contents field. If
183 nonzero, contents are in inferior. If the lval field is lval_memory,
184 the contents are in inferior memory at location.address plus offset.
185 The lval field may also be lval_register.
187 WARNING: This field is used by the code which handles watchpoints
188 (see breakpoint.c) to decide whether a particular value can be
189 watched by hardware watchpoints. If the lazy flag is set for
190 some member of a value chain, it is assumed that this member of
191 the chain doesn't need to be watched as part of watching the
192 value itself. This is how GDB avoids watching the entire struct
193 or array when the user wants to watch a single struct member or
194 array element. If you ever change the way lazy flag is set and
195 reset, be sure to consider this use as well! */
196 unsigned int lazy
: 1;
198 /* If value is a variable, is it initialized or not. */
199 unsigned int initialized
: 1;
201 /* If value is from the stack. If this is set, read_stack will be
202 used instead of read_memory to enable extra caching. */
203 unsigned int stack
: 1;
205 /* If the value has been released. */
206 unsigned int released
: 1;
208 /* 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_internalvar
1543 || value
->lval
== lval_internalvar_component
1544 || value
->lval
== lval_xcallable
)
1546 if (value
->parent
!= NULL
)
1547 return value_address (value
->parent
) + value
->offset
;
1548 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1550 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1551 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1554 return value
->location
.address
+ value
->offset
;
1558 value_raw_address (const struct value
*value
)
1560 if (value
->lval
== lval_internalvar
1561 || value
->lval
== lval_internalvar_component
1562 || value
->lval
== lval_xcallable
)
1564 return value
->location
.address
;
1568 set_value_address (struct value
*value
, CORE_ADDR addr
)
1570 gdb_assert (value
->lval
!= lval_internalvar
1571 && value
->lval
!= lval_internalvar_component
1572 && value
->lval
!= lval_xcallable
);
1573 value
->location
.address
= addr
;
1576 struct internalvar
**
1577 deprecated_value_internalvar_hack (struct value
*value
)
1579 return &value
->location
.internalvar
;
1583 deprecated_value_next_frame_id_hack (struct value
*value
)
1585 return &value
->location
.reg
.next_frame_id
;
1589 deprecated_value_regnum_hack (struct value
*value
)
1591 return &value
->location
.reg
.regnum
;
1595 deprecated_value_modifiable (const struct value
*value
)
1597 return value
->modifiable
;
1600 /* Return a mark in the value chain. All values allocated after the
1601 mark is obtained (except for those released) are subject to being freed
1602 if a subsequent value_free_to_mark is passed the mark. */
1609 /* Take a reference to VAL. VAL will not be deallocated until all
1610 references are released. */
1613 value_incref (struct value
*val
)
1615 val
->reference_count
++;
1618 /* Release a reference to VAL, which was acquired with value_incref.
1619 This function is also called to deallocate values from the value
1623 value_free (struct value
*val
)
1627 gdb_assert (val
->reference_count
> 0);
1628 val
->reference_count
--;
1629 if (val
->reference_count
> 0)
1632 /* If there's an associated parent value, drop our reference to
1634 if (val
->parent
!= NULL
)
1635 value_free (val
->parent
);
1637 if (VALUE_LVAL (val
) == lval_computed
)
1639 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1641 if (funcs
->free_closure
)
1642 funcs
->free_closure (val
);
1644 else if (VALUE_LVAL (val
) == lval_xcallable
)
1645 free_xmethod_worker (val
->location
.xm_worker
);
1647 xfree (val
->contents
);
1648 VEC_free (range_s
, val
->unavailable
);
1653 /* Free all values allocated since MARK was obtained by value_mark
1654 (except for those released). */
1656 value_free_to_mark (const struct value
*mark
)
1661 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1670 /* Free all the values that have been allocated (except for those released).
1671 Call after each command, successful or not.
1672 In practice this is called before each command, which is sufficient. */
1675 free_all_values (void)
1680 for (val
= all_values
; val
; val
= next
)
1690 /* Frees all the elements in a chain of values. */
1693 free_value_chain (struct value
*v
)
1699 next
= value_next (v
);
1704 /* Remove VAL from the chain all_values
1705 so it will not be freed automatically. */
1708 release_value (struct value
*val
)
1712 if (all_values
== val
)
1714 all_values
= val
->next
;
1720 for (v
= all_values
; v
; v
= v
->next
)
1724 v
->next
= val
->next
;
1732 /* If the value is not already released, release it.
1733 If the value is already released, increment its reference count.
1734 That is, this function ensures that the value is released from the
1735 value chain and that the caller owns a reference to it. */
1738 release_value_or_incref (struct value
*val
)
1743 release_value (val
);
1746 /* Release all values up to mark */
1748 value_release_to_mark (const struct value
*mark
)
1753 for (val
= next
= all_values
; next
; next
= next
->next
)
1755 if (next
->next
== mark
)
1757 all_values
= next
->next
;
1767 /* Return a copy of the value ARG.
1768 It contains the same contents, for same memory address,
1769 but it's a different block of storage. */
1772 value_copy (struct value
*arg
)
1774 struct type
*encl_type
= value_enclosing_type (arg
);
1777 if (value_lazy (arg
))
1778 val
= allocate_value_lazy (encl_type
);
1780 val
= allocate_value (encl_type
);
1781 val
->type
= arg
->type
;
1782 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1783 val
->location
= arg
->location
;
1784 val
->offset
= arg
->offset
;
1785 val
->bitpos
= arg
->bitpos
;
1786 val
->bitsize
= arg
->bitsize
;
1787 val
->lazy
= arg
->lazy
;
1788 val
->embedded_offset
= value_embedded_offset (arg
);
1789 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1790 val
->modifiable
= arg
->modifiable
;
1791 if (!value_lazy (val
))
1793 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1794 TYPE_LENGTH (value_enclosing_type (arg
)));
1797 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1798 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1799 set_value_parent (val
, arg
->parent
);
1800 if (VALUE_LVAL (val
) == lval_computed
)
1802 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1804 if (funcs
->copy_closure
)
1805 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1810 /* Return a "const" and/or "volatile" qualified version of the value V.
1811 If CNST is true, then the returned value will be qualified with
1813 if VOLTL is true, then the returned value will be qualified with
1817 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1819 struct type
*val_type
= value_type (v
);
1820 struct type
*enclosing_type
= value_enclosing_type (v
);
1821 struct value
*cv_val
= value_copy (v
);
1823 deprecated_set_value_type (cv_val
,
1824 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1825 set_value_enclosing_type (cv_val
,
1826 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1831 /* Return a version of ARG that is non-lvalue. */
1834 value_non_lval (struct value
*arg
)
1836 if (VALUE_LVAL (arg
) != not_lval
)
1838 struct type
*enc_type
= value_enclosing_type (arg
);
1839 struct value
*val
= allocate_value (enc_type
);
1841 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1842 TYPE_LENGTH (enc_type
));
1843 val
->type
= arg
->type
;
1844 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1845 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1851 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1854 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1856 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1858 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1859 v
->lval
= lval_memory
;
1860 v
->location
.address
= addr
;
1864 set_value_component_location (struct value
*component
,
1865 const struct value
*whole
)
1869 gdb_assert (whole
->lval
!= lval_xcallable
);
1871 if (whole
->lval
== lval_internalvar
)
1872 VALUE_LVAL (component
) = lval_internalvar_component
;
1874 VALUE_LVAL (component
) = whole
->lval
;
1876 component
->location
= whole
->location
;
1877 if (whole
->lval
== lval_computed
)
1879 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1881 if (funcs
->copy_closure
)
1882 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1885 /* If type has a dynamic resolved location property
1886 update it's value address. */
1887 type
= value_type (whole
);
1888 if (NULL
!= TYPE_DATA_LOCATION (type
)
1889 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1890 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1893 /* Access to the value history. */
1895 /* Record a new value in the value history.
1896 Returns the absolute history index of the entry. */
1899 record_latest_value (struct value
*val
)
1903 /* We don't want this value to have anything to do with the inferior anymore.
1904 In particular, "set $1 = 50" should not affect the variable from which
1905 the value was taken, and fast watchpoints should be able to assume that
1906 a value on the value history never changes. */
1907 if (value_lazy (val
))
1908 value_fetch_lazy (val
);
1909 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1910 from. This is a bit dubious, because then *&$1 does not just return $1
1911 but the current contents of that location. c'est la vie... */
1912 val
->modifiable
= 0;
1914 /* The value may have already been released, in which case we're adding a
1915 new reference for its entry in the history. That is why we call
1916 release_value_or_incref here instead of release_value. */
1917 release_value_or_incref (val
);
1919 /* Here we treat value_history_count as origin-zero
1920 and applying to the value being stored now. */
1922 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1925 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1927 newobj
->next
= value_history_chain
;
1928 value_history_chain
= newobj
;
1931 value_history_chain
->values
[i
] = val
;
1933 /* Now we regard value_history_count as origin-one
1934 and applying to the value just stored. */
1936 return ++value_history_count
;
1939 /* Return a copy of the value in the history with sequence number NUM. */
1942 access_value_history (int num
)
1944 struct value_history_chunk
*chunk
;
1949 absnum
+= value_history_count
;
1954 error (_("The history is empty."));
1956 error (_("There is only one value in the history."));
1958 error (_("History does not go back to $$%d."), -num
);
1960 if (absnum
> value_history_count
)
1961 error (_("History has not yet reached $%d."), absnum
);
1965 /* Now absnum is always absolute and origin zero. */
1967 chunk
= value_history_chain
;
1968 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1969 - absnum
/ VALUE_HISTORY_CHUNK
;
1971 chunk
= chunk
->next
;
1973 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1977 show_values (char *num_exp
, int from_tty
)
1985 /* "show values +" should print from the stored position.
1986 "show values <exp>" should print around value number <exp>. */
1987 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1988 num
= parse_and_eval_long (num_exp
) - 5;
1992 /* "show values" means print the last 10 values. */
1993 num
= value_history_count
- 9;
1999 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
2001 struct value_print_options opts
;
2003 val
= access_value_history (i
);
2004 printf_filtered (("$%d = "), i
);
2005 get_user_print_options (&opts
);
2006 value_print (val
, gdb_stdout
, &opts
);
2007 printf_filtered (("\n"));
2010 /* The next "show values +" should start after what we just printed. */
2013 /* Hitting just return after this command should do the same thing as
2014 "show values +". If num_exp is null, this is unnecessary, since
2015 "show values +" is not useful after "show values". */
2016 if (from_tty
&& num_exp
)
2023 enum internalvar_kind
2025 /* The internal variable is empty. */
2028 /* The value of the internal variable is provided directly as
2029 a GDB value object. */
2032 /* A fresh value is computed via a call-back routine on every
2033 access to the internal variable. */
2034 INTERNALVAR_MAKE_VALUE
,
2036 /* The internal variable holds a GDB internal convenience function. */
2037 INTERNALVAR_FUNCTION
,
2039 /* The variable holds an integer value. */
2040 INTERNALVAR_INTEGER
,
2042 /* The variable holds a GDB-provided string. */
2046 union internalvar_data
2048 /* A value object used with INTERNALVAR_VALUE. */
2049 struct value
*value
;
2051 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2054 /* The functions to call. */
2055 const struct internalvar_funcs
*functions
;
2057 /* The function's user-data. */
2061 /* The internal function used with INTERNALVAR_FUNCTION. */
2064 struct internal_function
*function
;
2065 /* True if this is the canonical name for the function. */
2069 /* An integer value used with INTERNALVAR_INTEGER. */
2072 /* If type is non-NULL, it will be used as the type to generate
2073 a value for this internal variable. If type is NULL, a default
2074 integer type for the architecture is used. */
2079 /* A string value used with INTERNALVAR_STRING. */
2083 /* Internal variables. These are variables within the debugger
2084 that hold values assigned by debugger commands.
2085 The user refers to them with a '$' prefix
2086 that does not appear in the variable names stored internally. */
2090 struct internalvar
*next
;
2093 /* We support various different kinds of content of an internal variable.
2094 enum internalvar_kind specifies the kind, and union internalvar_data
2095 provides the data associated with this particular kind. */
2097 enum internalvar_kind kind
;
2099 union internalvar_data u
;
2102 static struct internalvar
*internalvars
;
2104 /* If the variable does not already exist create it and give it the
2105 value given. If no value is given then the default is zero. */
2107 init_if_undefined_command (char* args
, int from_tty
)
2109 struct internalvar
* intvar
;
2111 /* Parse the expression - this is taken from set_command(). */
2112 expression_up expr
= parse_expression (args
);
2114 /* Validate the expression.
2115 Was the expression an assignment?
2116 Or even an expression at all? */
2117 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2118 error (_("Init-if-undefined requires an assignment expression."));
2120 /* Extract the variable from the parsed expression.
2121 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2122 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2123 error (_("The first parameter to init-if-undefined "
2124 "should be a GDB variable."));
2125 intvar
= expr
->elts
[2].internalvar
;
2127 /* Only evaluate the expression if the lvalue is void.
2128 This may still fail if the expresssion is invalid. */
2129 if (intvar
->kind
== INTERNALVAR_VOID
)
2130 evaluate_expression (expr
.get ());
2134 /* Look up an internal variable with name NAME. NAME should not
2135 normally include a dollar sign.
2137 If the specified internal variable does not exist,
2138 the return value is NULL. */
2140 struct internalvar
*
2141 lookup_only_internalvar (const char *name
)
2143 struct internalvar
*var
;
2145 for (var
= internalvars
; var
; var
= var
->next
)
2146 if (strcmp (var
->name
, name
) == 0)
2152 /* Complete NAME by comparing it to the names of internal variables.
2153 Returns a vector of newly allocated strings, or NULL if no matches
2157 complete_internalvar (const char *name
)
2159 VEC (char_ptr
) *result
= NULL
;
2160 struct internalvar
*var
;
2163 len
= strlen (name
);
2165 for (var
= internalvars
; var
; var
= var
->next
)
2166 if (strncmp (var
->name
, name
, len
) == 0)
2168 char *r
= xstrdup (var
->name
);
2170 VEC_safe_push (char_ptr
, result
, r
);
2176 /* Create an internal variable with name NAME and with a void value.
2177 NAME should not normally include a dollar sign. */
2179 struct internalvar
*
2180 create_internalvar (const char *name
)
2182 struct internalvar
*var
= XNEW (struct internalvar
);
2184 var
->name
= concat (name
, (char *)NULL
);
2185 var
->kind
= INTERNALVAR_VOID
;
2186 var
->next
= internalvars
;
2191 /* Create an internal variable with name NAME and register FUN as the
2192 function that value_of_internalvar uses to create a value whenever
2193 this variable is referenced. NAME should not normally include a
2194 dollar sign. DATA is passed uninterpreted to FUN when it is
2195 called. CLEANUP, if not NULL, is called when the internal variable
2196 is destroyed. It is passed DATA as its only argument. */
2198 struct internalvar
*
2199 create_internalvar_type_lazy (const char *name
,
2200 const struct internalvar_funcs
*funcs
,
2203 struct internalvar
*var
= create_internalvar (name
);
2205 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2206 var
->u
.make_value
.functions
= funcs
;
2207 var
->u
.make_value
.data
= data
;
2211 /* See documentation in value.h. */
2214 compile_internalvar_to_ax (struct internalvar
*var
,
2215 struct agent_expr
*expr
,
2216 struct axs_value
*value
)
2218 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2219 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2222 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2223 var
->u
.make_value
.data
);
2227 /* Look up an internal variable with name NAME. NAME should not
2228 normally include a dollar sign.
2230 If the specified internal variable does not exist,
2231 one is created, with a void value. */
2233 struct internalvar
*
2234 lookup_internalvar (const char *name
)
2236 struct internalvar
*var
;
2238 var
= lookup_only_internalvar (name
);
2242 return create_internalvar (name
);
2245 /* Return current value of internal variable VAR. For variables that
2246 are not inherently typed, use a value type appropriate for GDBARCH. */
2249 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2252 struct trace_state_variable
*tsv
;
2254 /* If there is a trace state variable of the same name, assume that
2255 is what we really want to see. */
2256 tsv
= find_trace_state_variable (var
->name
);
2259 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2261 if (tsv
->value_known
)
2262 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2265 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2271 case INTERNALVAR_VOID
:
2272 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2275 case INTERNALVAR_FUNCTION
:
2276 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2279 case INTERNALVAR_INTEGER
:
2280 if (!var
->u
.integer
.type
)
2281 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2282 var
->u
.integer
.val
);
2284 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2287 case INTERNALVAR_STRING
:
2288 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2289 builtin_type (gdbarch
)->builtin_char
);
2292 case INTERNALVAR_VALUE
:
2293 val
= value_copy (var
->u
.value
);
2294 if (value_lazy (val
))
2295 value_fetch_lazy (val
);
2298 case INTERNALVAR_MAKE_VALUE
:
2299 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2300 var
->u
.make_value
.data
);
2304 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2307 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2308 on this value go back to affect the original internal variable.
2310 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2311 no underlying modifyable state in the internal variable.
2313 Likewise, if the variable's value is a computed lvalue, we want
2314 references to it to produce another computed lvalue, where
2315 references and assignments actually operate through the
2316 computed value's functions.
2318 This means that internal variables with computed values
2319 behave a little differently from other internal variables:
2320 assignments to them don't just replace the previous value
2321 altogether. At the moment, this seems like the behavior we
2324 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2325 && val
->lval
!= lval_computed
)
2327 VALUE_LVAL (val
) = lval_internalvar
;
2328 VALUE_INTERNALVAR (val
) = var
;
2335 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2337 if (var
->kind
== INTERNALVAR_INTEGER
)
2339 *result
= var
->u
.integer
.val
;
2343 if (var
->kind
== INTERNALVAR_VALUE
)
2345 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2347 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2349 *result
= value_as_long (var
->u
.value
);
2358 get_internalvar_function (struct internalvar
*var
,
2359 struct internal_function
**result
)
2363 case INTERNALVAR_FUNCTION
:
2364 *result
= var
->u
.fn
.function
;
2373 set_internalvar_component (struct internalvar
*var
,
2374 LONGEST offset
, LONGEST bitpos
,
2375 LONGEST bitsize
, struct value
*newval
)
2378 struct gdbarch
*arch
;
2383 case INTERNALVAR_VALUE
:
2384 addr
= value_contents_writeable (var
->u
.value
);
2385 arch
= get_value_arch (var
->u
.value
);
2386 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2389 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2390 value_as_long (newval
), bitpos
, bitsize
);
2392 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2393 TYPE_LENGTH (value_type (newval
)));
2397 /* We can never get a component of any other kind. */
2398 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2403 set_internalvar (struct internalvar
*var
, struct value
*val
)
2405 enum internalvar_kind new_kind
;
2406 union internalvar_data new_data
= { 0 };
2408 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2409 error (_("Cannot overwrite convenience function %s"), var
->name
);
2411 /* Prepare new contents. */
2412 switch (TYPE_CODE (check_typedef (value_type (val
))))
2414 case TYPE_CODE_VOID
:
2415 new_kind
= INTERNALVAR_VOID
;
2418 case TYPE_CODE_INTERNAL_FUNCTION
:
2419 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2420 new_kind
= INTERNALVAR_FUNCTION
;
2421 get_internalvar_function (VALUE_INTERNALVAR (val
),
2422 &new_data
.fn
.function
);
2423 /* Copies created here are never canonical. */
2427 new_kind
= INTERNALVAR_VALUE
;
2428 new_data
.value
= value_copy (val
);
2429 new_data
.value
->modifiable
= 1;
2431 /* Force the value to be fetched from the target now, to avoid problems
2432 later when this internalvar is referenced and the target is gone or
2434 if (value_lazy (new_data
.value
))
2435 value_fetch_lazy (new_data
.value
);
2437 /* Release the value from the value chain to prevent it from being
2438 deleted by free_all_values. From here on this function should not
2439 call error () until new_data is installed into the var->u to avoid
2441 release_value (new_data
.value
);
2443 /* Internal variables which are created from values with a dynamic
2444 location don't need the location property of the origin anymore.
2445 The resolved dynamic location is used prior then any other address
2446 when accessing the value.
2447 If we keep it, we would still refer to the origin value.
2448 Remove the location property in case it exist. */
2449 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2454 /* Clean up old contents. */
2455 clear_internalvar (var
);
2458 var
->kind
= new_kind
;
2460 /* End code which must not call error(). */
2464 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2466 /* Clean up old contents. */
2467 clear_internalvar (var
);
2469 var
->kind
= INTERNALVAR_INTEGER
;
2470 var
->u
.integer
.type
= NULL
;
2471 var
->u
.integer
.val
= l
;
2475 set_internalvar_string (struct internalvar
*var
, const char *string
)
2477 /* Clean up old contents. */
2478 clear_internalvar (var
);
2480 var
->kind
= INTERNALVAR_STRING
;
2481 var
->u
.string
= xstrdup (string
);
2485 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2487 /* Clean up old contents. */
2488 clear_internalvar (var
);
2490 var
->kind
= INTERNALVAR_FUNCTION
;
2491 var
->u
.fn
.function
= f
;
2492 var
->u
.fn
.canonical
= 1;
2493 /* Variables installed here are always the canonical version. */
2497 clear_internalvar (struct internalvar
*var
)
2499 /* Clean up old contents. */
2502 case INTERNALVAR_VALUE
:
2503 value_free (var
->u
.value
);
2506 case INTERNALVAR_STRING
:
2507 xfree (var
->u
.string
);
2510 case INTERNALVAR_MAKE_VALUE
:
2511 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2512 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2519 /* Reset to void kind. */
2520 var
->kind
= INTERNALVAR_VOID
;
2524 internalvar_name (const struct internalvar
*var
)
2529 static struct internal_function
*
2530 create_internal_function (const char *name
,
2531 internal_function_fn handler
, void *cookie
)
2533 struct internal_function
*ifn
= XNEW (struct internal_function
);
2535 ifn
->name
= xstrdup (name
);
2536 ifn
->handler
= handler
;
2537 ifn
->cookie
= cookie
;
2542 value_internal_function_name (struct value
*val
)
2544 struct internal_function
*ifn
;
2547 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2548 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2549 gdb_assert (result
);
2555 call_internal_function (struct gdbarch
*gdbarch
,
2556 const struct language_defn
*language
,
2557 struct value
*func
, int argc
, struct value
**argv
)
2559 struct internal_function
*ifn
;
2562 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2563 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2564 gdb_assert (result
);
2566 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2569 /* The 'function' command. This does nothing -- it is just a
2570 placeholder to let "help function NAME" work. This is also used as
2571 the implementation of the sub-command that is created when
2572 registering an internal function. */
2574 function_command (char *command
, int from_tty
)
2579 /* Clean up if an internal function's command is destroyed. */
2581 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2583 xfree ((char *) self
->name
);
2584 xfree ((char *) self
->doc
);
2587 /* Add a new internal function. NAME is the name of the function; DOC
2588 is a documentation string describing the function. HANDLER is
2589 called when the function is invoked. COOKIE is an arbitrary
2590 pointer which is passed to HANDLER and is intended for "user
2593 add_internal_function (const char *name
, const char *doc
,
2594 internal_function_fn handler
, void *cookie
)
2596 struct cmd_list_element
*cmd
;
2597 struct internal_function
*ifn
;
2598 struct internalvar
*var
= lookup_internalvar (name
);
2600 ifn
= create_internal_function (name
, handler
, cookie
);
2601 set_internalvar_function (var
, ifn
);
2603 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2605 cmd
->destroyer
= function_destroyer
;
2608 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2609 prevent cycles / duplicates. */
2612 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2613 htab_t copied_types
)
2615 if (TYPE_OBJFILE (value
->type
) == objfile
)
2616 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2618 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2619 value
->enclosing_type
= copy_type_recursive (objfile
,
2620 value
->enclosing_type
,
2624 /* Likewise for internal variable VAR. */
2627 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2628 htab_t copied_types
)
2632 case INTERNALVAR_INTEGER
:
2633 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2635 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2638 case INTERNALVAR_VALUE
:
2639 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2644 /* Update the internal variables and value history when OBJFILE is
2645 discarded; we must copy the types out of the objfile. New global types
2646 will be created for every convenience variable which currently points to
2647 this objfile's types, and the convenience variables will be adjusted to
2648 use the new global types. */
2651 preserve_values (struct objfile
*objfile
)
2653 htab_t copied_types
;
2654 struct value_history_chunk
*cur
;
2655 struct internalvar
*var
;
2658 /* Create the hash table. We allocate on the objfile's obstack, since
2659 it is soon to be deleted. */
2660 copied_types
= create_copied_types_hash (objfile
);
2662 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2663 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2665 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2667 for (var
= internalvars
; var
; var
= var
->next
)
2668 preserve_one_internalvar (var
, objfile
, copied_types
);
2670 preserve_ext_lang_values (objfile
, copied_types
);
2672 htab_delete (copied_types
);
2676 show_convenience (char *ignore
, int from_tty
)
2678 struct gdbarch
*gdbarch
= get_current_arch ();
2679 struct internalvar
*var
;
2681 struct value_print_options opts
;
2683 get_user_print_options (&opts
);
2684 for (var
= internalvars
; var
; var
= var
->next
)
2691 printf_filtered (("$%s = "), var
->name
);
2697 val
= value_of_internalvar (gdbarch
, var
);
2698 value_print (val
, gdb_stdout
, &opts
);
2700 CATCH (ex
, RETURN_MASK_ERROR
)
2702 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2706 printf_filtered (("\n"));
2710 /* This text does not mention convenience functions on purpose.
2711 The user can't create them except via Python, and if Python support
2712 is installed this message will never be printed ($_streq will
2714 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2715 "Convenience variables have "
2716 "names starting with \"$\";\n"
2717 "use \"set\" as in \"set "
2718 "$foo = 5\" to define them.\n"));
2722 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2725 value_of_xmethod (struct xmethod_worker
*worker
)
2727 if (worker
->value
== NULL
)
2731 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2732 v
->lval
= lval_xcallable
;
2733 v
->location
.xm_worker
= worker
;
2738 return worker
->value
;
2741 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2744 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2746 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2747 && method
->lval
== lval_xcallable
&& argc
> 0);
2749 return get_xmethod_result_type (method
->location
.xm_worker
,
2750 argv
[0], argv
+ 1, argc
- 1);
2753 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2756 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2758 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2759 && method
->lval
== lval_xcallable
&& argc
> 0);
2761 return invoke_xmethod (method
->location
.xm_worker
,
2762 argv
[0], argv
+ 1, argc
- 1);
2765 /* Extract a value as a C number (either long or double).
2766 Knows how to convert fixed values to double, or
2767 floating values to long.
2768 Does not deallocate the value. */
2771 value_as_long (struct value
*val
)
2773 /* This coerces arrays and functions, which is necessary (e.g.
2774 in disassemble_command). It also dereferences references, which
2775 I suspect is the most logical thing to do. */
2776 val
= coerce_array (val
);
2777 return unpack_long (value_type (val
), value_contents (val
));
2781 value_as_double (struct value
*val
)
2786 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2788 error (_("Invalid floating value found in program."));
2792 /* Extract a value as a C pointer. Does not deallocate the value.
2793 Note that val's type may not actually be a pointer; value_as_long
2794 handles all the cases. */
2796 value_as_address (struct value
*val
)
2798 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2800 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2801 whether we want this to be true eventually. */
2803 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2804 non-address (e.g. argument to "signal", "info break", etc.), or
2805 for pointers to char, in which the low bits *are* significant. */
2806 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2809 /* There are several targets (IA-64, PowerPC, and others) which
2810 don't represent pointers to functions as simply the address of
2811 the function's entry point. For example, on the IA-64, a
2812 function pointer points to a two-word descriptor, generated by
2813 the linker, which contains the function's entry point, and the
2814 value the IA-64 "global pointer" register should have --- to
2815 support position-independent code. The linker generates
2816 descriptors only for those functions whose addresses are taken.
2818 On such targets, it's difficult for GDB to convert an arbitrary
2819 function address into a function pointer; it has to either find
2820 an existing descriptor for that function, or call malloc and
2821 build its own. On some targets, it is impossible for GDB to
2822 build a descriptor at all: the descriptor must contain a jump
2823 instruction; data memory cannot be executed; and code memory
2826 Upon entry to this function, if VAL is a value of type `function'
2827 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2828 value_address (val) is the address of the function. This is what
2829 you'll get if you evaluate an expression like `main'. The call
2830 to COERCE_ARRAY below actually does all the usual unary
2831 conversions, which includes converting values of type `function'
2832 to `pointer to function'. This is the challenging conversion
2833 discussed above. Then, `unpack_long' will convert that pointer
2834 back into an address.
2836 So, suppose the user types `disassemble foo' on an architecture
2837 with a strange function pointer representation, on which GDB
2838 cannot build its own descriptors, and suppose further that `foo'
2839 has no linker-built descriptor. The address->pointer conversion
2840 will signal an error and prevent the command from running, even
2841 though the next step would have been to convert the pointer
2842 directly back into the same address.
2844 The following shortcut avoids this whole mess. If VAL is a
2845 function, just return its address directly. */
2846 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2847 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2848 return value_address (val
);
2850 val
= coerce_array (val
);
2852 /* Some architectures (e.g. Harvard), map instruction and data
2853 addresses onto a single large unified address space. For
2854 instance: An architecture may consider a large integer in the
2855 range 0x10000000 .. 0x1000ffff to already represent a data
2856 addresses (hence not need a pointer to address conversion) while
2857 a small integer would still need to be converted integer to
2858 pointer to address. Just assume such architectures handle all
2859 integer conversions in a single function. */
2863 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2864 must admonish GDB hackers to make sure its behavior matches the
2865 compiler's, whenever possible.
2867 In general, I think GDB should evaluate expressions the same way
2868 the compiler does. When the user copies an expression out of
2869 their source code and hands it to a `print' command, they should
2870 get the same value the compiler would have computed. Any
2871 deviation from this rule can cause major confusion and annoyance,
2872 and needs to be justified carefully. In other words, GDB doesn't
2873 really have the freedom to do these conversions in clever and
2876 AndrewC pointed out that users aren't complaining about how GDB
2877 casts integers to pointers; they are complaining that they can't
2878 take an address from a disassembly listing and give it to `x/i'.
2879 This is certainly important.
2881 Adding an architecture method like integer_to_address() certainly
2882 makes it possible for GDB to "get it right" in all circumstances
2883 --- the target has complete control over how things get done, so
2884 people can Do The Right Thing for their target without breaking
2885 anyone else. The standard doesn't specify how integers get
2886 converted to pointers; usually, the ABI doesn't either, but
2887 ABI-specific code is a more reasonable place to handle it. */
2889 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2890 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2891 && gdbarch_integer_to_address_p (gdbarch
))
2892 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2893 value_contents (val
));
2895 return unpack_long (value_type (val
), value_contents (val
));
2899 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2900 as a long, or as a double, assuming the raw data is described
2901 by type TYPE. Knows how to convert different sizes of values
2902 and can convert between fixed and floating point. We don't assume
2903 any alignment for the raw data. Return value is in host byte order.
2905 If you want functions and arrays to be coerced to pointers, and
2906 references to be dereferenced, call value_as_long() instead.
2908 C++: It is assumed that the front-end has taken care of
2909 all matters concerning pointers to members. A pointer
2910 to member which reaches here is considered to be equivalent
2911 to an INT (or some size). After all, it is only an offset. */
2914 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2916 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2917 enum type_code code
= TYPE_CODE (type
);
2918 int len
= TYPE_LENGTH (type
);
2919 int nosign
= TYPE_UNSIGNED (type
);
2923 case TYPE_CODE_TYPEDEF
:
2924 return unpack_long (check_typedef (type
), valaddr
);
2925 case TYPE_CODE_ENUM
:
2926 case TYPE_CODE_FLAGS
:
2927 case TYPE_CODE_BOOL
:
2929 case TYPE_CODE_CHAR
:
2930 case TYPE_CODE_RANGE
:
2931 case TYPE_CODE_MEMBERPTR
:
2933 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2935 return extract_signed_integer (valaddr
, len
, byte_order
);
2938 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2940 case TYPE_CODE_DECFLOAT
:
2941 /* libdecnumber has a function to convert from decimal to integer, but
2942 it doesn't work when the decimal number has a fractional part. */
2943 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2947 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2948 whether we want this to be true eventually. */
2949 return extract_typed_address (valaddr
, type
);
2952 error (_("Value can't be converted to integer."));
2954 return 0; /* Placate lint. */
2957 /* Return a double value from the specified type and address.
2958 INVP points to an int which is set to 0 for valid value,
2959 1 for invalid value (bad float format). In either case,
2960 the returned double is OK to use. Argument is in target
2961 format, result is in host format. */
2964 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2966 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2967 enum type_code code
;
2971 *invp
= 0; /* Assume valid. */
2972 type
= check_typedef (type
);
2973 code
= TYPE_CODE (type
);
2974 len
= TYPE_LENGTH (type
);
2975 nosign
= TYPE_UNSIGNED (type
);
2976 if (code
== TYPE_CODE_FLT
)
2978 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2979 floating-point value was valid (using the macro
2980 INVALID_FLOAT). That test/macro have been removed.
2982 It turns out that only the VAX defined this macro and then
2983 only in a non-portable way. Fixing the portability problem
2984 wouldn't help since the VAX floating-point code is also badly
2985 bit-rotten. The target needs to add definitions for the
2986 methods gdbarch_float_format and gdbarch_double_format - these
2987 exactly describe the target floating-point format. The
2988 problem here is that the corresponding floatformat_vax_f and
2989 floatformat_vax_d values these methods should be set to are
2990 also not defined either. Oops!
2992 Hopefully someone will add both the missing floatformat
2993 definitions and the new cases for floatformat_is_valid (). */
2995 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
3001 return extract_typed_floating (valaddr
, type
);
3003 else if (code
== TYPE_CODE_DECFLOAT
)
3004 return decimal_to_doublest (valaddr
, len
, byte_order
);
3007 /* Unsigned -- be sure we compensate for signed LONGEST. */
3008 return (ULONGEST
) unpack_long (type
, valaddr
);
3012 /* Signed -- we are OK with unpack_long. */
3013 return unpack_long (type
, valaddr
);
3017 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3018 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3019 We don't assume any alignment for the raw data. Return value is in
3022 If you want functions and arrays to be coerced to pointers, and
3023 references to be dereferenced, call value_as_address() instead.
3025 C++: It is assumed that the front-end has taken care of
3026 all matters concerning pointers to members. A pointer
3027 to member which reaches here is considered to be equivalent
3028 to an INT (or some size). After all, it is only an offset. */
3031 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3033 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3034 whether we want this to be true eventually. */
3035 return unpack_long (type
, valaddr
);
3039 /* Get the value of the FIELDNO'th field (which must be static) of
3043 value_static_field (struct type
*type
, int fieldno
)
3045 struct value
*retval
;
3047 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3049 case FIELD_LOC_KIND_PHYSADDR
:
3050 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3051 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3053 case FIELD_LOC_KIND_PHYSNAME
:
3055 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3056 /* TYPE_FIELD_NAME (type, fieldno); */
3057 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3059 if (sym
.symbol
== NULL
)
3061 /* With some compilers, e.g. HP aCC, static data members are
3062 reported as non-debuggable symbols. */
3063 struct bound_minimal_symbol msym
3064 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3067 return allocate_optimized_out_value (type
);
3070 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3071 BMSYMBOL_VALUE_ADDRESS (msym
));
3075 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3079 gdb_assert_not_reached ("unexpected field location kind");
3085 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3086 You have to be careful here, since the size of the data area for the value
3087 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3088 than the old enclosing type, you have to allocate more space for the
3092 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3094 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3096 check_type_length_before_alloc (new_encl_type
);
3098 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3101 val
->enclosing_type
= new_encl_type
;
3104 /* Given a value ARG1 (offset by OFFSET bytes)
3105 of a struct or union type ARG_TYPE,
3106 extract and return the value of one of its (non-static) fields.
3107 FIELDNO says which field. */
3110 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3111 int fieldno
, struct type
*arg_type
)
3115 struct gdbarch
*arch
= get_value_arch (arg1
);
3116 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3118 arg_type
= check_typedef (arg_type
);
3119 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3121 /* Call check_typedef on our type to make sure that, if TYPE
3122 is a TYPE_CODE_TYPEDEF, its length is set to the length
3123 of the target type instead of zero. However, we do not
3124 replace the typedef type by the target type, because we want
3125 to keep the typedef in order to be able to print the type
3126 description correctly. */
3127 check_typedef (type
);
3129 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3131 /* Handle packed fields.
3133 Create a new value for the bitfield, with bitpos and bitsize
3134 set. If possible, arrange offset and bitpos so that we can
3135 do a single aligned read of the size of the containing type.
3136 Otherwise, adjust offset to the byte containing the first
3137 bit. Assume that the address, offset, and embedded offset
3138 are sufficiently aligned. */
3140 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3141 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3143 v
= allocate_value_lazy (type
);
3144 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3145 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3146 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3147 v
->bitpos
= bitpos
% container_bitsize
;
3149 v
->bitpos
= bitpos
% 8;
3150 v
->offset
= (value_embedded_offset (arg1
)
3152 + (bitpos
- v
->bitpos
) / 8);
3153 set_value_parent (v
, arg1
);
3154 if (!value_lazy (arg1
))
3155 value_fetch_lazy (v
);
3157 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3159 /* This field is actually a base subobject, so preserve the
3160 entire object's contents for later references to virtual
3164 /* Lazy register values with offsets are not supported. */
3165 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3166 value_fetch_lazy (arg1
);
3168 /* We special case virtual inheritance here because this
3169 requires access to the contents, which we would rather avoid
3170 for references to ordinary fields of unavailable values. */
3171 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3172 boffset
= baseclass_offset (arg_type
, fieldno
,
3173 value_contents (arg1
),
3174 value_embedded_offset (arg1
),
3175 value_address (arg1
),
3178 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3180 if (value_lazy (arg1
))
3181 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3184 v
= allocate_value (value_enclosing_type (arg1
));
3185 value_contents_copy_raw (v
, 0, arg1
, 0,
3186 TYPE_LENGTH (value_enclosing_type (arg1
)));
3189 v
->offset
= value_offset (arg1
);
3190 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3192 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3194 /* Field is a dynamic data member. */
3196 gdb_assert (0 == offset
);
3197 /* We expect an already resolved data location. */
3198 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3199 /* For dynamic data types defer memory allocation
3200 until we actual access the value. */
3201 v
= allocate_value_lazy (type
);
3205 /* Plain old data member */
3206 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3207 / (HOST_CHAR_BIT
* unit_size
));
3209 /* Lazy register values with offsets are not supported. */
3210 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3211 value_fetch_lazy (arg1
);
3213 if (value_lazy (arg1
))
3214 v
= allocate_value_lazy (type
);
3217 v
= allocate_value (type
);
3218 value_contents_copy_raw (v
, value_embedded_offset (v
),
3219 arg1
, value_embedded_offset (arg1
) + offset
,
3220 type_length_units (type
));
3222 v
->offset
= (value_offset (arg1
) + offset
3223 + value_embedded_offset (arg1
));
3225 set_value_component_location (v
, arg1
);
3229 /* Given a value ARG1 of a struct or union type,
3230 extract and return the value of one of its (non-static) fields.
3231 FIELDNO says which field. */
3234 value_field (struct value
*arg1
, int fieldno
)
3236 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3239 /* Return a non-virtual function as a value.
3240 F is the list of member functions which contains the desired method.
3241 J is an index into F which provides the desired method.
3243 We only use the symbol for its address, so be happy with either a
3244 full symbol or a minimal symbol. */
3247 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3248 int j
, struct type
*type
,
3252 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3253 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3255 struct bound_minimal_symbol msym
;
3257 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3260 memset (&msym
, 0, sizeof (msym
));
3264 gdb_assert (sym
== NULL
);
3265 msym
= lookup_bound_minimal_symbol (physname
);
3266 if (msym
.minsym
== NULL
)
3270 v
= allocate_value (ftype
);
3273 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3277 /* The minimal symbol might point to a function descriptor;
3278 resolve it to the actual code address instead. */
3279 struct objfile
*objfile
= msym
.objfile
;
3280 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3282 set_value_address (v
,
3283 gdbarch_convert_from_func_ptr_addr
3284 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3289 if (type
!= value_type (*arg1p
))
3290 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3291 value_addr (*arg1p
)));
3293 /* Move the `this' pointer according to the offset.
3294 VALUE_OFFSET (*arg1p) += offset; */
3302 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3303 VALADDR, and store the result in *RESULT.
3304 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3306 Extracting bits depends on endianness of the machine. Compute the
3307 number of least significant bits to discard. For big endian machines,
3308 we compute the total number of bits in the anonymous object, subtract
3309 off the bit count from the MSB of the object to the MSB of the
3310 bitfield, then the size of the bitfield, which leaves the LSB discard
3311 count. For little endian machines, the discard count is simply the
3312 number of bits from the LSB of the anonymous object to the LSB of the
3315 If the field is signed, we also do sign extension. */
3318 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3319 LONGEST bitpos
, LONGEST bitsize
)
3321 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3326 LONGEST read_offset
;
3328 /* Read the minimum number of bytes required; there may not be
3329 enough bytes to read an entire ULONGEST. */
3330 field_type
= check_typedef (field_type
);
3332 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3334 bytes_read
= TYPE_LENGTH (field_type
);
3336 read_offset
= bitpos
/ 8;
3338 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3339 bytes_read
, byte_order
);
3341 /* Extract bits. See comment above. */
3343 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3344 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3346 lsbcount
= (bitpos
% 8);
3349 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3350 If the field is signed, and is negative, then sign extend. */
3352 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3354 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3356 if (!TYPE_UNSIGNED (field_type
))
3358 if (val
& (valmask
^ (valmask
>> 1)))
3368 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3369 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3370 ORIGINAL_VALUE, which must not be NULL. See
3371 unpack_value_bits_as_long for more details. */
3374 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3375 LONGEST embedded_offset
, int fieldno
,
3376 const struct value
*val
, LONGEST
*result
)
3378 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3379 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3380 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3383 gdb_assert (val
!= NULL
);
3385 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3386 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3387 || !value_bits_available (val
, bit_offset
, bitsize
))
3390 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3395 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3396 object at VALADDR. See unpack_bits_as_long for more details. */
3399 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3401 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3402 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3403 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3405 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3408 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3409 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3410 the contents in DEST_VAL, zero or sign extending if the type of
3411 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3412 VAL. If the VAL's contents required to extract the bitfield from
3413 are unavailable/optimized out, DEST_VAL is correspondingly
3414 marked unavailable/optimized out. */
3417 unpack_value_bitfield (struct value
*dest_val
,
3418 LONGEST bitpos
, LONGEST bitsize
,
3419 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3420 const struct value
*val
)
3422 enum bfd_endian byte_order
;
3425 struct type
*field_type
= value_type (dest_val
);
3427 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3429 /* First, unpack and sign extend the bitfield as if it was wholly
3430 valid. Optimized out/unavailable bits are read as zero, but
3431 that's OK, as they'll end up marked below. If the VAL is
3432 wholly-invalid we may have skipped allocating its contents,
3433 though. See allocate_optimized_out_value. */
3434 if (valaddr
!= NULL
)
3438 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3440 store_signed_integer (value_contents_raw (dest_val
),
3441 TYPE_LENGTH (field_type
), byte_order
, num
);
3444 /* Now copy the optimized out / unavailability ranges to the right
3446 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3447 if (byte_order
== BFD_ENDIAN_BIG
)
3448 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3451 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3452 val
, src_bit_offset
, bitsize
);
3455 /* Return a new value with type TYPE, which is FIELDNO field of the
3456 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3457 of VAL. If the VAL's contents required to extract the bitfield
3458 from are unavailable/optimized out, the new value is
3459 correspondingly marked unavailable/optimized out. */
3462 value_field_bitfield (struct type
*type
, int fieldno
,
3463 const gdb_byte
*valaddr
,
3464 LONGEST embedded_offset
, const struct value
*val
)
3466 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3467 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3468 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3470 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3471 valaddr
, embedded_offset
, val
);
3476 /* Modify the value of a bitfield. ADDR points to a block of memory in
3477 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3478 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3479 indicate which bits (in target bit order) comprise the bitfield.
3480 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3481 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3484 modify_field (struct type
*type
, gdb_byte
*addr
,
3485 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3487 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3489 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3492 /* Normalize BITPOS. */
3496 /* If a negative fieldval fits in the field in question, chop
3497 off the sign extension bits. */
3498 if ((~fieldval
& ~(mask
>> 1)) == 0)
3501 /* Warn if value is too big to fit in the field in question. */
3502 if (0 != (fieldval
& ~mask
))
3504 /* FIXME: would like to include fieldval in the message, but
3505 we don't have a sprintf_longest. */
3506 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3508 /* Truncate it, otherwise adjoining fields may be corrupted. */
3512 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3513 false valgrind reports. */
3515 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3516 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3518 /* Shifting for bit field depends on endianness of the target machine. */
3519 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3520 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3522 oword
&= ~(mask
<< bitpos
);
3523 oword
|= fieldval
<< bitpos
;
3525 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3528 /* Pack NUM into BUF using a target format of TYPE. */
3531 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3533 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3536 type
= check_typedef (type
);
3537 len
= TYPE_LENGTH (type
);
3539 switch (TYPE_CODE (type
))
3542 case TYPE_CODE_CHAR
:
3543 case TYPE_CODE_ENUM
:
3544 case TYPE_CODE_FLAGS
:
3545 case TYPE_CODE_BOOL
:
3546 case TYPE_CODE_RANGE
:
3547 case TYPE_CODE_MEMBERPTR
:
3548 store_signed_integer (buf
, len
, byte_order
, num
);
3553 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3557 error (_("Unexpected type (%d) encountered for integer constant."),
3563 /* Pack NUM into BUF using a target format of TYPE. */
3566 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3569 enum bfd_endian byte_order
;
3571 type
= check_typedef (type
);
3572 len
= TYPE_LENGTH (type
);
3573 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3575 switch (TYPE_CODE (type
))
3578 case TYPE_CODE_CHAR
:
3579 case TYPE_CODE_ENUM
:
3580 case TYPE_CODE_FLAGS
:
3581 case TYPE_CODE_BOOL
:
3582 case TYPE_CODE_RANGE
:
3583 case TYPE_CODE_MEMBERPTR
:
3584 store_unsigned_integer (buf
, len
, byte_order
, num
);
3589 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3593 error (_("Unexpected type (%d) encountered "
3594 "for unsigned integer constant."),
3600 /* Convert C numbers into newly allocated values. */
3603 value_from_longest (struct type
*type
, LONGEST num
)
3605 struct value
*val
= allocate_value (type
);
3607 pack_long (value_contents_raw (val
), type
, num
);
3612 /* Convert C unsigned numbers into newly allocated values. */
3615 value_from_ulongest (struct type
*type
, ULONGEST num
)
3617 struct value
*val
= allocate_value (type
);
3619 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3625 /* Create a value representing a pointer of type TYPE to the address
3629 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3631 struct value
*val
= allocate_value (type
);
3633 store_typed_address (value_contents_raw (val
),
3634 check_typedef (type
), addr
);
3639 /* Create a value of type TYPE whose contents come from VALADDR, if it
3640 is non-null, and whose memory address (in the inferior) is
3641 ADDRESS. The type of the created value may differ from the passed
3642 type TYPE. Make sure to retrieve values new type after this call.
3643 Note that TYPE is not passed through resolve_dynamic_type; this is
3644 a special API intended for use only by Ada. */
3647 value_from_contents_and_address_unresolved (struct type
*type
,
3648 const gdb_byte
*valaddr
,
3653 if (valaddr
== NULL
)
3654 v
= allocate_value_lazy (type
);
3656 v
= value_from_contents (type
, valaddr
);
3657 set_value_address (v
, address
);
3658 VALUE_LVAL (v
) = lval_memory
;
3662 /* Create a value of type TYPE whose contents come from VALADDR, if it
3663 is non-null, and whose memory address (in the inferior) is
3664 ADDRESS. The type of the created value may differ from the passed
3665 type TYPE. Make sure to retrieve values new type after this call. */
3668 value_from_contents_and_address (struct type
*type
,
3669 const gdb_byte
*valaddr
,
3672 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3673 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3676 if (valaddr
== NULL
)
3677 v
= allocate_value_lazy (resolved_type
);
3679 v
= value_from_contents (resolved_type
, valaddr
);
3680 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3681 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3682 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3683 set_value_address (v
, address
);
3684 VALUE_LVAL (v
) = lval_memory
;
3688 /* Create a value of type TYPE holding the contents CONTENTS.
3689 The new value is `not_lval'. */
3692 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3694 struct value
*result
;
3696 result
= allocate_value (type
);
3697 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3702 value_from_double (struct type
*type
, DOUBLEST num
)
3704 struct value
*val
= allocate_value (type
);
3705 struct type
*base_type
= check_typedef (type
);
3706 enum type_code code
= TYPE_CODE (base_type
);
3708 if (code
== TYPE_CODE_FLT
)
3710 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3713 error (_("Unexpected type encountered for floating constant."));
3719 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3721 struct value
*val
= allocate_value (type
);
3723 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3727 /* Extract a value from the history file. Input will be of the form
3728 $digits or $$digits. See block comment above 'write_dollar_variable'
3732 value_from_history_ref (const char *h
, const char **endp
)
3744 /* Find length of numeral string. */
3745 for (; isdigit (h
[len
]); len
++)
3748 /* Make sure numeral string is not part of an identifier. */
3749 if (h
[len
] == '_' || isalpha (h
[len
]))
3752 /* Now collect the index value. */
3757 /* For some bizarre reason, "$$" is equivalent to "$$1",
3758 rather than to "$$0" as it ought to be! */
3766 index
= -strtol (&h
[2], &local_end
, 10);
3774 /* "$" is equivalent to "$0". */
3782 index
= strtol (&h
[1], &local_end
, 10);
3787 return access_value_history (index
);
3790 /* Get the component value (offset by OFFSET bytes) of a struct or
3791 union WHOLE. Component's type is TYPE. */
3794 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3798 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3799 v
= allocate_value_lazy (type
);
3802 v
= allocate_value (type
);
3803 value_contents_copy (v
, value_embedded_offset (v
),
3804 whole
, value_embedded_offset (whole
) + offset
,
3805 type_length_units (type
));
3807 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3808 set_value_component_location (v
, whole
);
3814 coerce_ref_if_computed (const struct value
*arg
)
3816 const struct lval_funcs
*funcs
;
3818 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3821 if (value_lval_const (arg
) != lval_computed
)
3824 funcs
= value_computed_funcs (arg
);
3825 if (funcs
->coerce_ref
== NULL
)
3828 return funcs
->coerce_ref (arg
);
3831 /* Look at value.h for description. */
3834 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3835 const struct type
*original_type
,
3836 const struct value
*original_value
)
3838 /* Re-adjust type. */
3839 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3841 /* Add embedding info. */
3842 set_value_enclosing_type (value
, enc_type
);
3843 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3845 /* We may be pointing to an object of some derived type. */
3846 return value_full_object (value
, NULL
, 0, 0, 0);
3850 coerce_ref (struct value
*arg
)
3852 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3853 struct value
*retval
;
3854 struct type
*enc_type
;
3856 retval
= coerce_ref_if_computed (arg
);
3860 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3863 enc_type
= check_typedef (value_enclosing_type (arg
));
3864 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3866 retval
= value_at_lazy (enc_type
,
3867 unpack_pointer (value_type (arg
),
3868 value_contents (arg
)));
3869 enc_type
= value_type (retval
);
3870 return readjust_indirect_value_type (retval
, enc_type
,
3871 value_type_arg_tmp
, arg
);
3875 coerce_array (struct value
*arg
)
3879 arg
= coerce_ref (arg
);
3880 type
= check_typedef (value_type (arg
));
3882 switch (TYPE_CODE (type
))
3884 case TYPE_CODE_ARRAY
:
3885 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3886 arg
= value_coerce_array (arg
);
3888 case TYPE_CODE_FUNC
:
3889 arg
= value_coerce_function (arg
);
3896 /* Return the return value convention that will be used for the
3899 enum return_value_convention
3900 struct_return_convention (struct gdbarch
*gdbarch
,
3901 struct value
*function
, struct type
*value_type
)
3903 enum type_code code
= TYPE_CODE (value_type
);
3905 if (code
== TYPE_CODE_ERROR
)
3906 error (_("Function return type unknown."));
3908 /* Probe the architecture for the return-value convention. */
3909 return gdbarch_return_value (gdbarch
, function
, value_type
,
3913 /* Return true if the function returning the specified type is using
3914 the convention of returning structures in memory (passing in the
3915 address as a hidden first parameter). */
3918 using_struct_return (struct gdbarch
*gdbarch
,
3919 struct value
*function
, struct type
*value_type
)
3921 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3922 /* A void return value is never in memory. See also corresponding
3923 code in "print_return_value". */
3926 return (struct_return_convention (gdbarch
, function
, value_type
)
3927 != RETURN_VALUE_REGISTER_CONVENTION
);
3930 /* Set the initialized field in a value struct. */
3933 set_value_initialized (struct value
*val
, int status
)
3935 val
->initialized
= status
;
3938 /* Return the initialized field in a value struct. */
3941 value_initialized (const struct value
*val
)
3943 return val
->initialized
;
3946 /* Load the actual content of a lazy value. Fetch the data from the
3947 user's process and clear the lazy flag to indicate that the data in
3948 the buffer is valid.
3950 If the value is zero-length, we avoid calling read_memory, which
3951 would abort. We mark the value as fetched anyway -- all 0 bytes of
3955 value_fetch_lazy (struct value
*val
)
3957 gdb_assert (value_lazy (val
));
3958 allocate_value_contents (val
);
3959 /* A value is either lazy, or fully fetched. The
3960 availability/validity is only established as we try to fetch a
3962 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3963 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3964 if (value_bitsize (val
))
3966 /* To read a lazy bitfield, read the entire enclosing value. This
3967 prevents reading the same block of (possibly volatile) memory once
3968 per bitfield. It would be even better to read only the containing
3969 word, but we have no way to record that just specific bits of a
3970 value have been fetched. */
3971 struct type
*type
= check_typedef (value_type (val
));
3972 struct value
*parent
= value_parent (val
);
3974 if (value_lazy (parent
))
3975 value_fetch_lazy (parent
);
3977 unpack_value_bitfield (val
,
3978 value_bitpos (val
), value_bitsize (val
),
3979 value_contents_for_printing (parent
),
3980 value_offset (val
), parent
);
3982 else if (VALUE_LVAL (val
) == lval_memory
)
3984 CORE_ADDR addr
= value_address (val
);
3985 struct type
*type
= check_typedef (value_enclosing_type (val
));
3987 if (TYPE_LENGTH (type
))
3988 read_value_memory (val
, 0, value_stack (val
),
3989 addr
, value_contents_all_raw (val
),
3990 type_length_units (type
));
3992 else if (VALUE_LVAL (val
) == lval_register
)
3994 struct frame_info
*next_frame
;
3996 struct type
*type
= check_typedef (value_type (val
));
3997 struct value
*new_val
= val
, *mark
= value_mark ();
3999 /* Offsets are not supported here; lazy register values must
4000 refer to the entire register. */
4001 gdb_assert (value_offset (val
) == 0);
4003 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
4005 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
4007 next_frame
= frame_find_by_id (next_frame_id
);
4008 regnum
= VALUE_REGNUM (new_val
);
4010 gdb_assert (next_frame
!= NULL
);
4012 /* Convertible register routines are used for multi-register
4013 values and for interpretation in different types
4014 (e.g. float or int from a double register). Lazy
4015 register values should have the register's natural type,
4016 so they do not apply. */
4017 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
4020 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
4021 Since a "->next" operation was performed when setting
4022 this field, we do not need to perform a "next" operation
4023 again when unwinding the register. That's why
4024 frame_unwind_register_value() is called here instead of
4025 get_frame_register_value(). */
4026 new_val
= frame_unwind_register_value (next_frame
, regnum
);
4028 /* If we get another lazy lval_register value, it means the
4029 register is found by reading it from NEXT_FRAME's next frame.
4030 frame_unwind_register_value should never return a value with
4031 the frame id pointing to NEXT_FRAME. If it does, it means we
4032 either have two consecutive frames with the same frame id
4033 in the frame chain, or some code is trying to unwind
4034 behind get_prev_frame's back (e.g., a frame unwind
4035 sniffer trying to unwind), bypassing its validations. In
4036 any case, it should always be an internal error to end up
4037 in this situation. */
4038 if (VALUE_LVAL (new_val
) == lval_register
4039 && value_lazy (new_val
)
4040 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
4041 internal_error (__FILE__
, __LINE__
,
4042 _("infinite loop while fetching a register"));
4045 /* If it's still lazy (for instance, a saved register on the
4046 stack), fetch it. */
4047 if (value_lazy (new_val
))
4048 value_fetch_lazy (new_val
);
4050 /* Copy the contents and the unavailability/optimized-out
4051 meta-data from NEW_VAL to VAL. */
4052 set_value_lazy (val
, 0);
4053 value_contents_copy (val
, value_embedded_offset (val
),
4054 new_val
, value_embedded_offset (new_val
),
4055 type_length_units (type
));
4059 struct gdbarch
*gdbarch
;
4060 struct frame_info
*frame
;
4061 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
4062 so that the frame level will be shown correctly. */
4063 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4064 regnum
= VALUE_REGNUM (val
);
4065 gdbarch
= get_frame_arch (frame
);
4067 fprintf_unfiltered (gdb_stdlog
,
4068 "{ value_fetch_lazy "
4069 "(frame=%d,regnum=%d(%s),...) ",
4070 frame_relative_level (frame
), regnum
,
4071 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4073 fprintf_unfiltered (gdb_stdlog
, "->");
4074 if (value_optimized_out (new_val
))
4076 fprintf_unfiltered (gdb_stdlog
, " ");
4077 val_print_optimized_out (new_val
, gdb_stdlog
);
4082 const gdb_byte
*buf
= value_contents (new_val
);
4084 if (VALUE_LVAL (new_val
) == lval_register
)
4085 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4086 VALUE_REGNUM (new_val
));
4087 else if (VALUE_LVAL (new_val
) == lval_memory
)
4088 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4090 value_address (new_val
)));
4092 fprintf_unfiltered (gdb_stdlog
, " computed");
4094 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4095 fprintf_unfiltered (gdb_stdlog
, "[");
4096 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4097 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4098 fprintf_unfiltered (gdb_stdlog
, "]");
4101 fprintf_unfiltered (gdb_stdlog
, " }\n");
4104 /* Dispose of the intermediate values. This prevents
4105 watchpoints from trying to watch the saved frame pointer. */
4106 value_free_to_mark (mark
);
4108 else if (VALUE_LVAL (val
) == lval_computed
4109 && value_computed_funcs (val
)->read
!= NULL
)
4110 value_computed_funcs (val
)->read (val
);
4112 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4114 set_value_lazy (val
, 0);
4117 /* Implementation of the convenience function $_isvoid. */
4119 static struct value
*
4120 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4121 const struct language_defn
*language
,
4122 void *cookie
, int argc
, struct value
**argv
)
4127 error (_("You must provide one argument for $_isvoid."));
4129 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4131 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4135 _initialize_values (void)
4137 add_cmd ("convenience", no_class
, show_convenience
, _("\
4138 Debugger convenience (\"$foo\") variables and functions.\n\
4139 Convenience variables are created when you assign them values;\n\
4140 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4142 A few convenience variables are given values automatically:\n\
4143 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4144 \"$__\" holds the contents of the last address examined with \"x\"."
4147 Convenience functions are defined via the Python API."
4150 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4152 add_cmd ("values", no_set_class
, show_values
, _("\
4153 Elements of value history around item number IDX (or last ten)."),
4156 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4157 Initialize a convenience variable if necessary.\n\
4158 init-if-undefined VARIABLE = EXPRESSION\n\
4159 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4160 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4161 VARIABLE is already initialized."));
4163 add_prefix_cmd ("function", no_class
, function_command
, _("\
4164 Placeholder command for showing help on convenience functions."),
4165 &functionlist
, "function ", 0, &cmdlist
);
4167 add_internal_function ("_isvoid", _("\
4168 Check whether an expression is void.\n\
4169 Usage: $_isvoid (expression)\n\
4170 Return 1 if the expression is void, zero otherwise."),
4171 isvoid_internal_fn
, NULL
);
4173 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4174 class_support
, &max_value_size
, _("\
4175 Set maximum sized value gdb will load from the inferior."), _("\
4176 Show maximum sized value gdb will load from the inferior."), _("\
4177 Use this to control the maximum size, in bytes, of a value that gdb\n\
4178 will load from the inferior. Setting this value to 'unlimited'\n\
4179 disables checking.\n\
4180 Setting this does not invalidate already allocated values, it only\n\
4181 prevents future values, larger than this size, from being allocated."),
4183 show_max_value_size
,
4184 &setlist
, &showlist
);