1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2018 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"
33 #include "target-float.h"
36 #include "cli/cli-decode.h"
37 #include "extension.h"
39 #include "tracepoint.h"
41 #include "user-regs.h"
43 #include "completer.h"
45 /* Definition of a user function. */
46 struct internal_function
48 /* The name of the function. It is a bit odd to have this in the
49 function itself -- the user might use a differently-named
50 convenience variable to hold the function. */
54 internal_function_fn handler
;
56 /* User data for the handler. */
60 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
64 /* Lowest offset in the range. */
67 /* Length of the range. */
71 typedef struct range range_s
;
75 /* Returns true if the ranges defined by [offset1, offset1+len1) and
76 [offset2, offset2+len2) overlap. */
79 ranges_overlap (LONGEST offset1
, LONGEST len1
,
80 LONGEST offset2
, LONGEST len2
)
84 l
= std::max (offset1
, offset2
);
85 h
= std::min (offset1
+ len1
, offset2
+ len2
);
89 /* Returns true if the first argument is strictly less than the
90 second, useful for VEC_lower_bound. We keep ranges sorted by
91 offset and coalesce overlapping and contiguous ranges, so this just
92 compares the starting offset. */
95 range_lessthan (const range_s
*r1
, const range_s
*r2
)
97 return r1
->offset
< r2
->offset
;
100 /* Returns true if RANGES contains any range that overlaps [OFFSET,
104 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
109 what
.offset
= offset
;
110 what
.length
= length
;
112 /* We keep ranges sorted by offset and coalesce overlapping and
113 contiguous ranges, so to check if a range list contains a given
114 range, we can do a binary search for the position the given range
115 would be inserted if we only considered the starting OFFSET of
116 ranges. We call that position I. Since we also have LENGTH to
117 care for (this is a range afterall), we need to check if the
118 _previous_ range overlaps the I range. E.g.,
122 |---| |---| |------| ... |--|
127 In the case above, the binary search would return `I=1', meaning,
128 this OFFSET should be inserted at position 1, and the current
129 position 1 should be pushed further (and before 2). But, `0'
132 Then we need to check if the I range overlaps the I range itself.
137 |---| |---| |-------| ... |--|
143 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
147 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
149 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
153 if (i
< VEC_length (range_s
, ranges
))
155 struct range
*r
= VEC_index (range_s
, ranges
, i
);
157 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
164 static struct cmd_list_element
*functionlist
;
166 /* Note that the fields in this structure are arranged to save a bit
171 /* Type of value; either not an lval, or one of the various
172 different possible kinds of lval. */
175 /* Is it modifiable? Only relevant if lval != not_lval. */
176 unsigned int modifiable
: 1;
178 /* If zero, contents of this value are in the contents field. If
179 nonzero, contents are in inferior. If the lval field is lval_memory,
180 the contents are in inferior memory at location.address plus offset.
181 The lval field may also be lval_register.
183 WARNING: This field is used by the code which handles watchpoints
184 (see breakpoint.c) to decide whether a particular value can be
185 watched by hardware watchpoints. If the lazy flag is set for
186 some member of a value chain, it is assumed that this member of
187 the chain doesn't need to be watched as part of watching the
188 value itself. This is how GDB avoids watching the entire struct
189 or array when the user wants to watch a single struct member or
190 array element. If you ever change the way lazy flag is set and
191 reset, be sure to consider this use as well! */
192 unsigned int lazy
: 1;
194 /* If value is a variable, is it initialized or not. */
195 unsigned int initialized
: 1;
197 /* If value is from the stack. If this is set, read_stack will be
198 used instead of read_memory to enable extra caching. */
199 unsigned int stack
: 1;
201 /* If the value has been released. */
202 unsigned int released
: 1;
204 /* Location of value (if lval). */
207 /* If lval == lval_memory, this is the address in the inferior */
210 /*If lval == lval_register, the value is from a register. */
213 /* Register number. */
215 /* Frame ID of "next" frame to which a register value is relative.
216 If the register value is found relative to frame F, then the
217 frame id of F->next will be stored in next_frame_id. */
218 struct frame_id next_frame_id
;
221 /* Pointer to internal variable. */
222 struct internalvar
*internalvar
;
224 /* Pointer to xmethod worker. */
225 struct xmethod_worker
*xm_worker
;
227 /* If lval == lval_computed, this is a set of function pointers
228 to use to access and describe the value, and a closure pointer
232 /* Functions to call. */
233 const struct lval_funcs
*funcs
;
235 /* Closure for those functions to use. */
240 /* Describes offset of a value within lval of a structure in target
241 addressable memory units. Note also the member embedded_offset
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value
*parent
;
265 /* Type of the value. */
268 /* If a value represents a C++ object, then the `type' field gives
269 the object's compile-time type. If the object actually belongs
270 to some class derived from `type', perhaps with other base
271 classes and additional members, then `type' is just a subobject
272 of the real thing, and the full object is probably larger than
273 `type' would suggest.
275 If `type' is a dynamic class (i.e. one with a vtable), then GDB
276 can actually determine the object's run-time type by looking at
277 the run-time type information in the vtable. When this
278 information is available, we may elect to read in the entire
279 object, for several reasons:
281 - When printing the value, the user would probably rather see the
282 full object, not just the limited portion apparent from the
285 - If `type' has virtual base classes, then even printing `type'
286 alone may require reaching outside the `type' portion of the
287 object to wherever the virtual base class has been stored.
289 When we store the entire object, `enclosing_type' is the run-time
290 type -- the complete object -- and `embedded_offset' is the
291 offset of `type' within that larger type, in target addressable memory
292 units. The value_contents() macro takes `embedded_offset' into account,
293 so most GDB code continues to see the `type' portion of the value, just
294 as the inferior would.
296 If `type' is a pointer to an object, then `enclosing_type' is a
297 pointer to the object's run-time type, and `pointed_to_offset' is
298 the offset in target addressable memory units from the full object
299 to the pointed-to object -- that is, the value `embedded_offset' would
300 have if we followed the pointer and fetched the complete object.
301 (I don't really see the point. Why not just determine the
302 run-time type when you indirect, and avoid the special case? The
303 contents don't matter until you indirect anyway.)
305 If we're not doing anything fancy, `enclosing_type' is equal to
306 `type', and `embedded_offset' is zero, so everything works
308 struct type
*enclosing_type
;
309 LONGEST embedded_offset
;
310 LONGEST pointed_to_offset
;
312 /* Values are stored in a chain, so that they can be deleted easily
313 over calls to the inferior. Values assigned to internal
314 variables, put into the value history or exposed to Python are
315 taken off this list. */
318 /* Actual contents of the value. Target byte-order. NULL or not
319 valid if lazy is nonzero. */
322 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
323 rather than available, since the common and default case is for a
324 value to be available. This is filled in at value read time.
325 The unavailable ranges are tracked in bits. Note that a contents
326 bit that has been optimized out doesn't really exist in the
327 program, so it can't be marked unavailable either. */
328 VEC(range_s
) *unavailable
;
330 /* Likewise, but for optimized out contents (a chunk of the value of
331 a variable that does not actually exist in the program). If LVAL
332 is lval_register, this is a register ($pc, $sp, etc., never a
333 program variable) that has not been saved in the frame. Not
334 saved registers and optimized-out program variables values are
335 treated pretty much the same, except not-saved registers have a
336 different string representation and related error strings. */
337 VEC(range_s
) *optimized_out
;
343 get_value_arch (const struct value
*value
)
345 return get_type_arch (value_type (value
));
349 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
351 gdb_assert (!value
->lazy
);
353 return !ranges_contain (value
->unavailable
, offset
, length
);
357 value_bytes_available (const struct value
*value
,
358 LONGEST offset
, LONGEST length
)
360 return value_bits_available (value
,
361 offset
* TARGET_CHAR_BIT
,
362 length
* TARGET_CHAR_BIT
);
366 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
368 gdb_assert (!value
->lazy
);
370 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
374 value_entirely_available (struct value
*value
)
376 /* We can only tell whether the whole value is available when we try
379 value_fetch_lazy (value
);
381 if (VEC_empty (range_s
, value
->unavailable
))
386 /* Returns true if VALUE is entirely covered by RANGES. If the value
387 is lazy, it'll be read now. Note that RANGE is a pointer to
388 pointer because reading the value might change *RANGE. */
391 value_entirely_covered_by_range_vector (struct value
*value
,
392 VEC(range_s
) **ranges
)
394 /* We can only tell whether the whole value is optimized out /
395 unavailable when we try to read it. */
397 value_fetch_lazy (value
);
399 if (VEC_length (range_s
, *ranges
) == 1)
401 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
404 && t
->length
== (TARGET_CHAR_BIT
405 * TYPE_LENGTH (value_enclosing_type (value
))))
413 value_entirely_unavailable (struct value
*value
)
415 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
419 value_entirely_optimized_out (struct value
*value
)
421 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
424 /* Insert into the vector pointed to by VECTORP the bit range starting of
425 OFFSET bits, and extending for the next LENGTH bits. */
428 insert_into_bit_range_vector (VEC(range_s
) **vectorp
,
429 LONGEST offset
, LONGEST length
)
434 /* Insert the range sorted. If there's overlap or the new range
435 would be contiguous with an existing range, merge. */
437 newr
.offset
= offset
;
438 newr
.length
= length
;
440 /* Do a binary search for the position the given range would be
441 inserted if we only considered the starting OFFSET of ranges.
442 Call that position I. Since we also have LENGTH to care for
443 (this is a range afterall), we need to check if the _previous_
444 range overlaps the I range. E.g., calling R the new range:
446 #1 - overlaps with previous
450 |---| |---| |------| ... |--|
455 In the case #1 above, the binary search would return `I=1',
456 meaning, this OFFSET should be inserted at position 1, and the
457 current position 1 should be pushed further (and become 2). But,
458 note that `0' overlaps with R, so we want to merge them.
460 A similar consideration needs to be taken if the new range would
461 be contiguous with the previous range:
463 #2 - contiguous with previous
467 |--| |---| |------| ... |--|
472 If there's no overlap with the previous range, as in:
474 #3 - not overlapping and not contiguous
478 |--| |---| |------| ... |--|
485 #4 - R is the range with lowest offset
489 |--| |---| |------| ... |--|
494 ... we just push the new range to I.
496 All the 4 cases above need to consider that the new range may
497 also overlap several of the ranges that follow, or that R may be
498 contiguous with the following range, and merge. E.g.,
500 #5 - overlapping following ranges
503 |------------------------|
504 |--| |---| |------| ... |--|
513 |--| |---| |------| ... |--|
520 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
523 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
525 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
528 ULONGEST l
= std::min (bef
->offset
, offset
);
529 ULONGEST h
= std::max (bef
->offset
+ bef
->length
, offset
+ length
);
535 else if (offset
== bef
->offset
+ bef
->length
)
538 bef
->length
+= length
;
544 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
550 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
553 /* Check whether the ranges following the one we've just added or
554 touched can be folded in (#5 above). */
555 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
562 /* Get the range we just touched. */
563 t
= VEC_index (range_s
, *vectorp
, i
);
567 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
568 if (r
->offset
<= t
->offset
+ t
->length
)
572 l
= std::min (t
->offset
, r
->offset
);
573 h
= std::max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
582 /* If we couldn't merge this one, we won't be able to
583 merge following ones either, since the ranges are
584 always sorted by OFFSET. */
589 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
594 mark_value_bits_unavailable (struct value
*value
,
595 LONGEST offset
, LONGEST length
)
597 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
601 mark_value_bytes_unavailable (struct value
*value
,
602 LONGEST offset
, LONGEST length
)
604 mark_value_bits_unavailable (value
,
605 offset
* TARGET_CHAR_BIT
,
606 length
* TARGET_CHAR_BIT
);
609 /* Find the first range in RANGES that overlaps the range defined by
610 OFFSET and LENGTH, starting at element POS in the RANGES vector,
611 Returns the index into RANGES where such overlapping range was
612 found, or -1 if none was found. */
615 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
616 LONGEST offset
, LONGEST length
)
621 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
622 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
628 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
629 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
632 It must always be the case that:
633 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
635 It is assumed that memory can be accessed from:
636 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
638 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
639 / TARGET_CHAR_BIT) */
641 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
642 const gdb_byte
*ptr2
, size_t offset2_bits
,
645 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
646 == offset2_bits
% TARGET_CHAR_BIT
);
648 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
651 gdb_byte mask
, b1
, b2
;
653 /* The offset from the base pointers PTR1 and PTR2 is not a complete
654 number of bytes. A number of bits up to either the next exact
655 byte boundary, or LENGTH_BITS (which ever is sooner) will be
657 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
658 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
659 mask
= (1 << bits
) - 1;
661 if (length_bits
< bits
)
663 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
667 /* Now load the two bytes and mask off the bits we care about. */
668 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
669 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
674 /* Now update the length and offsets to take account of the bits
675 we've just compared. */
677 offset1_bits
+= bits
;
678 offset2_bits
+= bits
;
681 if (length_bits
% TARGET_CHAR_BIT
!= 0)
685 gdb_byte mask
, b1
, b2
;
687 /* The length is not an exact number of bytes. After the previous
688 IF.. block then the offsets are byte aligned, or the
689 length is zero (in which case this code is not reached). Compare
690 a number of bits at the end of the region, starting from an exact
692 bits
= length_bits
% TARGET_CHAR_BIT
;
693 o1
= offset1_bits
+ length_bits
- bits
;
694 o2
= offset2_bits
+ length_bits
- bits
;
696 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
697 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
699 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
700 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
702 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
703 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
713 /* We've now taken care of any stray "bits" at the start, or end of
714 the region to compare, the remainder can be covered with a simple
716 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
717 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
718 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
720 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
721 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
722 length_bits
/ TARGET_CHAR_BIT
);
725 /* Length is zero, regions match. */
729 /* Helper struct for find_first_range_overlap_and_match and
730 value_contents_bits_eq. Keep track of which slot of a given ranges
731 vector have we last looked at. */
733 struct ranges_and_idx
736 VEC(range_s
) *ranges
;
738 /* The range we've last found in RANGES. Given ranges are sorted,
739 we can start the next lookup here. */
743 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
744 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
745 ranges starting at OFFSET2 bits. Return true if the ranges match
746 and fill in *L and *H with the overlapping window relative to
747 (both) OFFSET1 or OFFSET2. */
750 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
751 struct ranges_and_idx
*rp2
,
752 LONGEST offset1
, LONGEST offset2
,
753 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
755 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
757 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
760 if (rp1
->idx
== -1 && rp2
->idx
== -1)
766 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
774 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
775 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
777 /* Get the unavailable windows intersected by the incoming
778 ranges. The first and last ranges that overlap the argument
779 range may be wider than said incoming arguments ranges. */
780 l1
= std::max (offset1
, r1
->offset
);
781 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
783 l2
= std::max (offset2
, r2
->offset
);
784 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
786 /* Make them relative to the respective start offsets, so we can
787 compare them for equality. */
794 /* Different ranges, no match. */
795 if (l1
!= l2
|| h1
!= h2
)
804 /* Helper function for value_contents_eq. The only difference is that
805 this function is bit rather than byte based.
807 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
808 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
809 Return true if the available bits match. */
812 value_contents_bits_eq (const struct value
*val1
, int offset1
,
813 const struct value
*val2
, int offset2
,
816 /* Each array element corresponds to a ranges source (unavailable,
817 optimized out). '1' is for VAL1, '2' for VAL2. */
818 struct ranges_and_idx rp1
[2], rp2
[2];
820 /* See function description in value.h. */
821 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
823 /* We shouldn't be trying to compare past the end of the values. */
824 gdb_assert (offset1
+ length
825 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
826 gdb_assert (offset2
+ length
827 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
829 memset (&rp1
, 0, sizeof (rp1
));
830 memset (&rp2
, 0, sizeof (rp2
));
831 rp1
[0].ranges
= val1
->unavailable
;
832 rp2
[0].ranges
= val2
->unavailable
;
833 rp1
[1].ranges
= val1
->optimized_out
;
834 rp2
[1].ranges
= val2
->optimized_out
;
838 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
841 for (i
= 0; i
< 2; i
++)
843 ULONGEST l_tmp
, h_tmp
;
845 /* The contents only match equal if the invalid/unavailable
846 contents ranges match as well. */
847 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
848 offset1
, offset2
, length
,
852 /* We're interested in the lowest/first range found. */
853 if (i
== 0 || l_tmp
< l
)
860 /* Compare the available/valid contents. */
861 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
862 val2
->contents
, offset2
, l
) != 0)
874 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
875 const struct value
*val2
, LONGEST offset2
,
878 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
879 val2
, offset2
* TARGET_CHAR_BIT
,
880 length
* TARGET_CHAR_BIT
);
884 /* The value-history records all the values printed by print commands
885 during this session. */
887 static std::vector
<value_ref_ptr
> value_history
;
890 /* List of all value objects currently allocated
891 (except for those released by calls to release_value)
892 This is so they can be freed after each command. */
894 static struct value
*all_values
;
896 /* Allocate a lazy value for type TYPE. Its actual content is
897 "lazily" allocated too: the content field of the return value is
898 NULL; it will be allocated when it is fetched from the target. */
901 allocate_value_lazy (struct type
*type
)
905 /* Call check_typedef on our type to make sure that, if TYPE
906 is a TYPE_CODE_TYPEDEF, its length is set to the length
907 of the target type instead of zero. However, we do not
908 replace the typedef type by the target type, because we want
909 to keep the typedef in order to be able to set the VAL's type
910 description correctly. */
911 check_typedef (type
);
913 val
= XCNEW (struct value
);
914 val
->contents
= NULL
;
915 val
->next
= all_values
;
918 val
->enclosing_type
= type
;
919 VALUE_LVAL (val
) = not_lval
;
920 val
->location
.address
= 0;
925 val
->embedded_offset
= 0;
926 val
->pointed_to_offset
= 0;
928 val
->initialized
= 1; /* Default to initialized. */
930 /* Values start out on the all_values chain. */
931 val
->reference_count
= 1;
936 /* The maximum size, in bytes, that GDB will try to allocate for a value.
937 The initial value of 64k was not selected for any specific reason, it is
938 just a reasonable starting point. */
940 static int max_value_size
= 65536; /* 64k bytes */
942 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
943 LONGEST, otherwise GDB will not be able to parse integer values from the
944 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
945 be unable to parse "set max-value-size 2".
947 As we want a consistent GDB experience across hosts with different sizes
948 of LONGEST, this arbitrary minimum value was selected, so long as this
949 is bigger than LONGEST on all GDB supported hosts we're fine. */
951 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
952 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
954 /* Implement the "set max-value-size" command. */
957 set_max_value_size (const char *args
, int from_tty
,
958 struct cmd_list_element
*c
)
960 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
962 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
964 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
965 error (_("max-value-size set too low, increasing to %d bytes"),
970 /* Implement the "show max-value-size" command. */
973 show_max_value_size (struct ui_file
*file
, int from_tty
,
974 struct cmd_list_element
*c
, const char *value
)
976 if (max_value_size
== -1)
977 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
979 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
983 /* Called before we attempt to allocate or reallocate a buffer for the
984 contents of a value. TYPE is the type of the value for which we are
985 allocating the buffer. If the buffer is too large (based on the user
986 controllable setting) then throw an error. If this function returns
987 then we should attempt to allocate the buffer. */
990 check_type_length_before_alloc (const struct type
*type
)
992 unsigned int length
= TYPE_LENGTH (type
);
994 if (max_value_size
> -1 && length
> max_value_size
)
996 if (TYPE_NAME (type
) != NULL
)
997 error (_("value of type `%s' requires %u bytes, which is more "
998 "than max-value-size"), TYPE_NAME (type
), length
);
1000 error (_("value requires %u bytes, which is more than "
1001 "max-value-size"), length
);
1005 /* Allocate the contents of VAL if it has not been allocated yet. */
1008 allocate_value_contents (struct value
*val
)
1012 check_type_length_before_alloc (val
->enclosing_type
);
1014 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1018 /* Allocate a value and its contents for type TYPE. */
1021 allocate_value (struct type
*type
)
1023 struct value
*val
= allocate_value_lazy (type
);
1025 allocate_value_contents (val
);
1030 /* Allocate a value that has the correct length
1031 for COUNT repetitions of type TYPE. */
1034 allocate_repeat_value (struct type
*type
, int count
)
1036 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1037 /* FIXME-type-allocation: need a way to free this type when we are
1039 struct type
*array_type
1040 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1042 return allocate_value (array_type
);
1046 allocate_computed_value (struct type
*type
,
1047 const struct lval_funcs
*funcs
,
1050 struct value
*v
= allocate_value_lazy (type
);
1052 VALUE_LVAL (v
) = lval_computed
;
1053 v
->location
.computed
.funcs
= funcs
;
1054 v
->location
.computed
.closure
= closure
;
1059 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1062 allocate_optimized_out_value (struct type
*type
)
1064 struct value
*retval
= allocate_value_lazy (type
);
1066 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1067 set_value_lazy (retval
, 0);
1071 /* Accessor methods. */
1074 value_next (const struct value
*value
)
1080 value_type (const struct value
*value
)
1085 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1091 value_offset (const struct value
*value
)
1093 return value
->offset
;
1096 set_value_offset (struct value
*value
, LONGEST offset
)
1098 value
->offset
= offset
;
1102 value_bitpos (const struct value
*value
)
1104 return value
->bitpos
;
1107 set_value_bitpos (struct value
*value
, LONGEST bit
)
1109 value
->bitpos
= bit
;
1113 value_bitsize (const struct value
*value
)
1115 return value
->bitsize
;
1118 set_value_bitsize (struct value
*value
, LONGEST bit
)
1120 value
->bitsize
= bit
;
1124 value_parent (const struct value
*value
)
1126 return value
->parent
;
1132 set_value_parent (struct value
*value
, struct value
*parent
)
1134 struct value
*old
= value
->parent
;
1136 value
->parent
= parent
;
1138 value_incref (parent
);
1143 value_contents_raw (struct value
*value
)
1145 struct gdbarch
*arch
= get_value_arch (value
);
1146 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1148 allocate_value_contents (value
);
1149 return value
->contents
+ value
->embedded_offset
* unit_size
;
1153 value_contents_all_raw (struct value
*value
)
1155 allocate_value_contents (value
);
1156 return value
->contents
;
1160 value_enclosing_type (const struct value
*value
)
1162 return value
->enclosing_type
;
1165 /* Look at value.h for description. */
1168 value_actual_type (struct value
*value
, int resolve_simple_types
,
1169 int *real_type_found
)
1171 struct value_print_options opts
;
1172 struct type
*result
;
1174 get_user_print_options (&opts
);
1176 if (real_type_found
)
1177 *real_type_found
= 0;
1178 result
= value_type (value
);
1179 if (opts
.objectprint
)
1181 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1182 fetch its rtti type. */
1183 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1184 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1186 && !value_optimized_out (value
))
1188 struct type
*real_type
;
1190 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1193 if (real_type_found
)
1194 *real_type_found
= 1;
1198 else if (resolve_simple_types
)
1200 if (real_type_found
)
1201 *real_type_found
= 1;
1202 result
= value_enclosing_type (value
);
1210 error_value_optimized_out (void)
1212 error (_("value has been optimized out"));
1216 require_not_optimized_out (const struct value
*value
)
1218 if (!VEC_empty (range_s
, value
->optimized_out
))
1220 if (value
->lval
== lval_register
)
1221 error (_("register has not been saved in frame"));
1223 error_value_optimized_out ();
1228 require_available (const struct value
*value
)
1230 if (!VEC_empty (range_s
, value
->unavailable
))
1231 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1235 value_contents_for_printing (struct value
*value
)
1238 value_fetch_lazy (value
);
1239 return value
->contents
;
1243 value_contents_for_printing_const (const struct value
*value
)
1245 gdb_assert (!value
->lazy
);
1246 return value
->contents
;
1250 value_contents_all (struct value
*value
)
1252 const gdb_byte
*result
= value_contents_for_printing (value
);
1253 require_not_optimized_out (value
);
1254 require_available (value
);
1258 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1259 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1262 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1263 VEC (range_s
) *src_range
, int src_bit_offset
,
1269 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1273 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1274 h
= std::min (r
->offset
+ r
->length
,
1275 (LONGEST
) src_bit_offset
+ bit_length
);
1278 insert_into_bit_range_vector (dst_range
,
1279 dst_bit_offset
+ (l
- src_bit_offset
),
1284 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1285 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1288 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1289 const struct value
*src
, int src_bit_offset
,
1292 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1293 src
->unavailable
, src_bit_offset
,
1295 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1296 src
->optimized_out
, src_bit_offset
,
1300 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1301 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1302 contents, starting at DST_OFFSET. If unavailable contents are
1303 being copied from SRC, the corresponding DST contents are marked
1304 unavailable accordingly. Neither DST nor SRC may be lazy
1307 It is assumed the contents of DST in the [DST_OFFSET,
1308 DST_OFFSET+LENGTH) range are wholly available. */
1311 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1312 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1314 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1315 struct gdbarch
*arch
= get_value_arch (src
);
1316 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1318 /* A lazy DST would make that this copy operation useless, since as
1319 soon as DST's contents were un-lazied (by a later value_contents
1320 call, say), the contents would be overwritten. A lazy SRC would
1321 mean we'd be copying garbage. */
1322 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1324 /* The overwritten DST range gets unavailability ORed in, not
1325 replaced. Make sure to remember to implement replacing if it
1326 turns out actually necessary. */
1327 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1328 gdb_assert (!value_bits_any_optimized_out (dst
,
1329 TARGET_CHAR_BIT
* dst_offset
,
1330 TARGET_CHAR_BIT
* length
));
1332 /* Copy the data. */
1333 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1334 value_contents_all_raw (src
) + src_offset
* unit_size
,
1335 length
* unit_size
);
1337 /* Copy the meta-data, adjusted. */
1338 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1339 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1340 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1342 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1343 src
, src_bit_offset
,
1347 /* Copy LENGTH bytes of SRC value's (all) contents
1348 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1349 (all) contents, starting at DST_OFFSET. If unavailable contents
1350 are being copied from SRC, the corresponding DST contents are
1351 marked unavailable accordingly. DST must not be lazy. If SRC is
1352 lazy, it will be fetched now.
1354 It is assumed the contents of DST in the [DST_OFFSET,
1355 DST_OFFSET+LENGTH) range are wholly available. */
1358 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1359 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1362 value_fetch_lazy (src
);
1364 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1368 value_lazy (const struct value
*value
)
1374 set_value_lazy (struct value
*value
, int val
)
1380 value_stack (const struct value
*value
)
1382 return value
->stack
;
1386 set_value_stack (struct value
*value
, int val
)
1392 value_contents (struct value
*value
)
1394 const gdb_byte
*result
= value_contents_writeable (value
);
1395 require_not_optimized_out (value
);
1396 require_available (value
);
1401 value_contents_writeable (struct value
*value
)
1404 value_fetch_lazy (value
);
1405 return value_contents_raw (value
);
1409 value_optimized_out (struct value
*value
)
1411 /* We can only know if a value is optimized out once we have tried to
1413 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1417 value_fetch_lazy (value
);
1419 CATCH (ex
, RETURN_MASK_ERROR
)
1421 /* Fall back to checking value->optimized_out. */
1426 return !VEC_empty (range_s
, value
->optimized_out
);
1429 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1430 the following LENGTH bytes. */
1433 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1435 mark_value_bits_optimized_out (value
,
1436 offset
* TARGET_CHAR_BIT
,
1437 length
* TARGET_CHAR_BIT
);
1443 mark_value_bits_optimized_out (struct value
*value
,
1444 LONGEST offset
, LONGEST length
)
1446 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1450 value_bits_synthetic_pointer (const struct value
*value
,
1451 LONGEST offset
, LONGEST length
)
1453 if (value
->lval
!= lval_computed
1454 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1456 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1462 value_embedded_offset (const struct value
*value
)
1464 return value
->embedded_offset
;
1468 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1470 value
->embedded_offset
= val
;
1474 value_pointed_to_offset (const struct value
*value
)
1476 return value
->pointed_to_offset
;
1480 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1482 value
->pointed_to_offset
= val
;
1485 const struct lval_funcs
*
1486 value_computed_funcs (const struct value
*v
)
1488 gdb_assert (value_lval_const (v
) == lval_computed
);
1490 return v
->location
.computed
.funcs
;
1494 value_computed_closure (const struct value
*v
)
1496 gdb_assert (v
->lval
== lval_computed
);
1498 return v
->location
.computed
.closure
;
1502 deprecated_value_lval_hack (struct value
*value
)
1504 return &value
->lval
;
1508 value_lval_const (const struct value
*value
)
1514 value_address (const struct value
*value
)
1516 if (value
->lval
!= lval_memory
)
1518 if (value
->parent
!= NULL
)
1519 return value_address (value
->parent
) + value
->offset
;
1520 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1522 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1523 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1526 return value
->location
.address
+ value
->offset
;
1530 value_raw_address (const struct value
*value
)
1532 if (value
->lval
!= lval_memory
)
1534 return value
->location
.address
;
1538 set_value_address (struct value
*value
, CORE_ADDR addr
)
1540 gdb_assert (value
->lval
== lval_memory
);
1541 value
->location
.address
= addr
;
1544 struct internalvar
**
1545 deprecated_value_internalvar_hack (struct value
*value
)
1547 return &value
->location
.internalvar
;
1551 deprecated_value_next_frame_id_hack (struct value
*value
)
1553 gdb_assert (value
->lval
== lval_register
);
1554 return &value
->location
.reg
.next_frame_id
;
1558 deprecated_value_regnum_hack (struct value
*value
)
1560 gdb_assert (value
->lval
== lval_register
);
1561 return &value
->location
.reg
.regnum
;
1565 deprecated_value_modifiable (const struct value
*value
)
1567 return value
->modifiable
;
1570 /* Return a mark in the value chain. All values allocated after the
1571 mark is obtained (except for those released) are subject to being freed
1572 if a subsequent value_free_to_mark is passed the mark. */
1579 /* Take a reference to VAL. VAL will not be deallocated until all
1580 references are released. */
1583 value_incref (struct value
*val
)
1585 val
->reference_count
++;
1589 /* Release a reference to VAL, which was acquired with value_incref.
1590 This function is also called to deallocate values from the value
1594 value_decref (struct value
*val
)
1598 gdb_assert (val
->reference_count
> 0);
1599 val
->reference_count
--;
1600 if (val
->reference_count
> 0)
1603 /* If there's an associated parent value, drop our reference to
1605 if (val
->parent
!= NULL
)
1606 value_decref (val
->parent
);
1608 if (VALUE_LVAL (val
) == lval_computed
)
1610 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1612 if (funcs
->free_closure
)
1613 funcs
->free_closure (val
);
1615 else if (VALUE_LVAL (val
) == lval_xcallable
)
1616 delete val
->location
.xm_worker
;
1618 xfree (val
->contents
);
1619 VEC_free (range_s
, val
->unavailable
);
1624 /* Free all values allocated since MARK was obtained by value_mark
1625 (except for those released). */
1627 value_free_to_mark (const struct value
*mark
)
1632 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1641 /* Remove VAL from the chain all_values
1642 so it will not be freed automatically. */
1645 release_value (struct value
*val
)
1648 bool released
= false;
1651 return value_ref_ptr ();
1653 if (all_values
== val
)
1655 all_values
= val
->next
;
1661 for (v
= all_values
; v
; v
= v
->next
)
1665 v
->next
= val
->next
;
1675 /* We must always return an owned reference. Normally this
1676 happens because we transfer the reference from the value
1677 chain, but in this case the value was not on the chain. */
1681 return value_ref_ptr (val
);
1686 std::vector
<value_ref_ptr
>
1687 value_release_to_mark (const struct value
*mark
)
1689 std::vector
<value_ref_ptr
> result
;
1692 for (next
= all_values
; next
; next
= next
->next
)
1695 result
.emplace_back (next
);
1697 if (next
->next
== mark
)
1699 struct value
*save
= next
->next
;
1710 /* Return a copy of the value ARG.
1711 It contains the same contents, for same memory address,
1712 but it's a different block of storage. */
1715 value_copy (struct value
*arg
)
1717 struct type
*encl_type
= value_enclosing_type (arg
);
1720 if (value_lazy (arg
))
1721 val
= allocate_value_lazy (encl_type
);
1723 val
= allocate_value (encl_type
);
1724 val
->type
= arg
->type
;
1725 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1726 val
->location
= arg
->location
;
1727 val
->offset
= arg
->offset
;
1728 val
->bitpos
= arg
->bitpos
;
1729 val
->bitsize
= arg
->bitsize
;
1730 val
->lazy
= arg
->lazy
;
1731 val
->embedded_offset
= value_embedded_offset (arg
);
1732 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1733 val
->modifiable
= arg
->modifiable
;
1734 if (!value_lazy (val
))
1736 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1737 TYPE_LENGTH (value_enclosing_type (arg
)));
1740 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1741 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1742 set_value_parent (val
, arg
->parent
);
1743 if (VALUE_LVAL (val
) == lval_computed
)
1745 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1747 if (funcs
->copy_closure
)
1748 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1753 /* Return a "const" and/or "volatile" qualified version of the value V.
1754 If CNST is true, then the returned value will be qualified with
1756 if VOLTL is true, then the returned value will be qualified with
1760 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1762 struct type
*val_type
= value_type (v
);
1763 struct type
*enclosing_type
= value_enclosing_type (v
);
1764 struct value
*cv_val
= value_copy (v
);
1766 deprecated_set_value_type (cv_val
,
1767 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1768 set_value_enclosing_type (cv_val
,
1769 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1774 /* Return a version of ARG that is non-lvalue. */
1777 value_non_lval (struct value
*arg
)
1779 if (VALUE_LVAL (arg
) != not_lval
)
1781 struct type
*enc_type
= value_enclosing_type (arg
);
1782 struct value
*val
= allocate_value (enc_type
);
1784 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1785 TYPE_LENGTH (enc_type
));
1786 val
->type
= arg
->type
;
1787 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1788 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1794 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1797 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1799 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1801 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1802 v
->lval
= lval_memory
;
1803 v
->location
.address
= addr
;
1807 set_value_component_location (struct value
*component
,
1808 const struct value
*whole
)
1812 gdb_assert (whole
->lval
!= lval_xcallable
);
1814 if (whole
->lval
== lval_internalvar
)
1815 VALUE_LVAL (component
) = lval_internalvar_component
;
1817 VALUE_LVAL (component
) = whole
->lval
;
1819 component
->location
= whole
->location
;
1820 if (whole
->lval
== lval_computed
)
1822 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1824 if (funcs
->copy_closure
)
1825 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1828 /* If type has a dynamic resolved location property
1829 update it's value address. */
1830 type
= value_type (whole
);
1831 if (NULL
!= TYPE_DATA_LOCATION (type
)
1832 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1833 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1836 /* Access to the value history. */
1838 /* Record a new value in the value history.
1839 Returns the absolute history index of the entry. */
1842 record_latest_value (struct value
*val
)
1846 /* We don't want this value to have anything to do with the inferior anymore.
1847 In particular, "set $1 = 50" should not affect the variable from which
1848 the value was taken, and fast watchpoints should be able to assume that
1849 a value on the value history never changes. */
1850 if (value_lazy (val
))
1851 value_fetch_lazy (val
);
1852 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1853 from. This is a bit dubious, because then *&$1 does not just return $1
1854 but the current contents of that location. c'est la vie... */
1855 val
->modifiable
= 0;
1857 value_history
.push_back (release_value (val
));
1859 return value_history
.size ();
1862 /* Return a copy of the value in the history with sequence number NUM. */
1865 access_value_history (int num
)
1871 absnum
+= value_history
.size ();
1876 error (_("The history is empty."));
1878 error (_("There is only one value in the history."));
1880 error (_("History does not go back to $$%d."), -num
);
1882 if (absnum
> value_history
.size ())
1883 error (_("History has not yet reached $%d."), absnum
);
1887 return value_copy (value_history
[absnum
].get ());
1891 show_values (const char *num_exp
, int from_tty
)
1899 /* "show values +" should print from the stored position.
1900 "show values <exp>" should print around value number <exp>. */
1901 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1902 num
= parse_and_eval_long (num_exp
) - 5;
1906 /* "show values" means print the last 10 values. */
1907 num
= value_history
.size () - 9;
1913 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1915 struct value_print_options opts
;
1917 val
= access_value_history (i
);
1918 printf_filtered (("$%d = "), i
);
1919 get_user_print_options (&opts
);
1920 value_print (val
, gdb_stdout
, &opts
);
1921 printf_filtered (("\n"));
1924 /* The next "show values +" should start after what we just printed. */
1927 /* Hitting just return after this command should do the same thing as
1928 "show values +". If num_exp is null, this is unnecessary, since
1929 "show values +" is not useful after "show values". */
1930 if (from_tty
&& num_exp
)
1931 set_repeat_arguments ("+");
1934 enum internalvar_kind
1936 /* The internal variable is empty. */
1939 /* The value of the internal variable is provided directly as
1940 a GDB value object. */
1943 /* A fresh value is computed via a call-back routine on every
1944 access to the internal variable. */
1945 INTERNALVAR_MAKE_VALUE
,
1947 /* The internal variable holds a GDB internal convenience function. */
1948 INTERNALVAR_FUNCTION
,
1950 /* The variable holds an integer value. */
1951 INTERNALVAR_INTEGER
,
1953 /* The variable holds a GDB-provided string. */
1957 union internalvar_data
1959 /* A value object used with INTERNALVAR_VALUE. */
1960 struct value
*value
;
1962 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1965 /* The functions to call. */
1966 const struct internalvar_funcs
*functions
;
1968 /* The function's user-data. */
1972 /* The internal function used with INTERNALVAR_FUNCTION. */
1975 struct internal_function
*function
;
1976 /* True if this is the canonical name for the function. */
1980 /* An integer value used with INTERNALVAR_INTEGER. */
1983 /* If type is non-NULL, it will be used as the type to generate
1984 a value for this internal variable. If type is NULL, a default
1985 integer type for the architecture is used. */
1990 /* A string value used with INTERNALVAR_STRING. */
1994 /* Internal variables. These are variables within the debugger
1995 that hold values assigned by debugger commands.
1996 The user refers to them with a '$' prefix
1997 that does not appear in the variable names stored internally. */
2001 struct internalvar
*next
;
2004 /* We support various different kinds of content of an internal variable.
2005 enum internalvar_kind specifies the kind, and union internalvar_data
2006 provides the data associated with this particular kind. */
2008 enum internalvar_kind kind
;
2010 union internalvar_data u
;
2013 static struct internalvar
*internalvars
;
2015 /* If the variable does not already exist create it and give it the
2016 value given. If no value is given then the default is zero. */
2018 init_if_undefined_command (const char* args
, int from_tty
)
2020 struct internalvar
* intvar
;
2022 /* Parse the expression - this is taken from set_command(). */
2023 expression_up expr
= parse_expression (args
);
2025 /* Validate the expression.
2026 Was the expression an assignment?
2027 Or even an expression at all? */
2028 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2029 error (_("Init-if-undefined requires an assignment expression."));
2031 /* Extract the variable from the parsed expression.
2032 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2033 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2034 error (_("The first parameter to init-if-undefined "
2035 "should be a GDB variable."));
2036 intvar
= expr
->elts
[2].internalvar
;
2038 /* Only evaluate the expression if the lvalue is void.
2039 This may still fail if the expresssion is invalid. */
2040 if (intvar
->kind
== INTERNALVAR_VOID
)
2041 evaluate_expression (expr
.get ());
2045 /* Look up an internal variable with name NAME. NAME should not
2046 normally include a dollar sign.
2048 If the specified internal variable does not exist,
2049 the return value is NULL. */
2051 struct internalvar
*
2052 lookup_only_internalvar (const char *name
)
2054 struct internalvar
*var
;
2056 for (var
= internalvars
; var
; var
= var
->next
)
2057 if (strcmp (var
->name
, name
) == 0)
2063 /* Complete NAME by comparing it to the names of internal
2067 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2069 struct internalvar
*var
;
2072 len
= strlen (name
);
2074 for (var
= internalvars
; var
; var
= var
->next
)
2075 if (strncmp (var
->name
, name
, len
) == 0)
2077 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2079 tracker
.add_completion (std::move (copy
));
2083 /* Create an internal variable with name NAME and with a void value.
2084 NAME should not normally include a dollar sign. */
2086 struct internalvar
*
2087 create_internalvar (const char *name
)
2089 struct internalvar
*var
= XNEW (struct internalvar
);
2091 var
->name
= concat (name
, (char *)NULL
);
2092 var
->kind
= INTERNALVAR_VOID
;
2093 var
->next
= internalvars
;
2098 /* Create an internal variable with name NAME and register FUN as the
2099 function that value_of_internalvar uses to create a value whenever
2100 this variable is referenced. NAME should not normally include a
2101 dollar sign. DATA is passed uninterpreted to FUN when it is
2102 called. CLEANUP, if not NULL, is called when the internal variable
2103 is destroyed. It is passed DATA as its only argument. */
2105 struct internalvar
*
2106 create_internalvar_type_lazy (const char *name
,
2107 const struct internalvar_funcs
*funcs
,
2110 struct internalvar
*var
= create_internalvar (name
);
2112 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2113 var
->u
.make_value
.functions
= funcs
;
2114 var
->u
.make_value
.data
= data
;
2118 /* See documentation in value.h. */
2121 compile_internalvar_to_ax (struct internalvar
*var
,
2122 struct agent_expr
*expr
,
2123 struct axs_value
*value
)
2125 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2126 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2129 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2130 var
->u
.make_value
.data
);
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 one is created, with a void value. */
2140 struct internalvar
*
2141 lookup_internalvar (const char *name
)
2143 struct internalvar
*var
;
2145 var
= lookup_only_internalvar (name
);
2149 return create_internalvar (name
);
2152 /* Return current value of internal variable VAR. For variables that
2153 are not inherently typed, use a value type appropriate for GDBARCH. */
2156 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2159 struct trace_state_variable
*tsv
;
2161 /* If there is a trace state variable of the same name, assume that
2162 is what we really want to see. */
2163 tsv
= find_trace_state_variable (var
->name
);
2166 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2168 if (tsv
->value_known
)
2169 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2172 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2178 case INTERNALVAR_VOID
:
2179 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2182 case INTERNALVAR_FUNCTION
:
2183 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2186 case INTERNALVAR_INTEGER
:
2187 if (!var
->u
.integer
.type
)
2188 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2189 var
->u
.integer
.val
);
2191 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2194 case INTERNALVAR_STRING
:
2195 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2196 builtin_type (gdbarch
)->builtin_char
);
2199 case INTERNALVAR_VALUE
:
2200 val
= value_copy (var
->u
.value
);
2201 if (value_lazy (val
))
2202 value_fetch_lazy (val
);
2205 case INTERNALVAR_MAKE_VALUE
:
2206 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2207 var
->u
.make_value
.data
);
2211 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2214 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2215 on this value go back to affect the original internal variable.
2217 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2218 no underlying modifyable state in the internal variable.
2220 Likewise, if the variable's value is a computed lvalue, we want
2221 references to it to produce another computed lvalue, where
2222 references and assignments actually operate through the
2223 computed value's functions.
2225 This means that internal variables with computed values
2226 behave a little differently from other internal variables:
2227 assignments to them don't just replace the previous value
2228 altogether. At the moment, this seems like the behavior we
2231 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2232 && val
->lval
!= lval_computed
)
2234 VALUE_LVAL (val
) = lval_internalvar
;
2235 VALUE_INTERNALVAR (val
) = var
;
2242 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2244 if (var
->kind
== INTERNALVAR_INTEGER
)
2246 *result
= var
->u
.integer
.val
;
2250 if (var
->kind
== INTERNALVAR_VALUE
)
2252 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2254 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2256 *result
= value_as_long (var
->u
.value
);
2265 get_internalvar_function (struct internalvar
*var
,
2266 struct internal_function
**result
)
2270 case INTERNALVAR_FUNCTION
:
2271 *result
= var
->u
.fn
.function
;
2280 set_internalvar_component (struct internalvar
*var
,
2281 LONGEST offset
, LONGEST bitpos
,
2282 LONGEST bitsize
, struct value
*newval
)
2285 struct gdbarch
*arch
;
2290 case INTERNALVAR_VALUE
:
2291 addr
= value_contents_writeable (var
->u
.value
);
2292 arch
= get_value_arch (var
->u
.value
);
2293 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2296 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2297 value_as_long (newval
), bitpos
, bitsize
);
2299 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2300 TYPE_LENGTH (value_type (newval
)));
2304 /* We can never get a component of any other kind. */
2305 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2310 set_internalvar (struct internalvar
*var
, struct value
*val
)
2312 enum internalvar_kind new_kind
;
2313 union internalvar_data new_data
= { 0 };
2315 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2316 error (_("Cannot overwrite convenience function %s"), var
->name
);
2318 /* Prepare new contents. */
2319 switch (TYPE_CODE (check_typedef (value_type (val
))))
2321 case TYPE_CODE_VOID
:
2322 new_kind
= INTERNALVAR_VOID
;
2325 case TYPE_CODE_INTERNAL_FUNCTION
:
2326 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2327 new_kind
= INTERNALVAR_FUNCTION
;
2328 get_internalvar_function (VALUE_INTERNALVAR (val
),
2329 &new_data
.fn
.function
);
2330 /* Copies created here are never canonical. */
2334 new_kind
= INTERNALVAR_VALUE
;
2335 new_data
.value
= value_copy (val
);
2336 new_data
.value
->modifiable
= 1;
2338 /* Force the value to be fetched from the target now, to avoid problems
2339 later when this internalvar is referenced and the target is gone or
2341 if (value_lazy (new_data
.value
))
2342 value_fetch_lazy (new_data
.value
);
2344 /* Release the value from the value chain to prevent it from being
2345 deleted by free_all_values. From here on this function should not
2346 call error () until new_data is installed into the var->u to avoid
2348 release_value (new_data
.value
).release ();
2350 /* Internal variables which are created from values with a dynamic
2351 location don't need the location property of the origin anymore.
2352 The resolved dynamic location is used prior then any other address
2353 when accessing the value.
2354 If we keep it, we would still refer to the origin value.
2355 Remove the location property in case it exist. */
2356 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2361 /* Clean up old contents. */
2362 clear_internalvar (var
);
2365 var
->kind
= new_kind
;
2367 /* End code which must not call error(). */
2371 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2373 /* Clean up old contents. */
2374 clear_internalvar (var
);
2376 var
->kind
= INTERNALVAR_INTEGER
;
2377 var
->u
.integer
.type
= NULL
;
2378 var
->u
.integer
.val
= l
;
2382 set_internalvar_string (struct internalvar
*var
, const char *string
)
2384 /* Clean up old contents. */
2385 clear_internalvar (var
);
2387 var
->kind
= INTERNALVAR_STRING
;
2388 var
->u
.string
= xstrdup (string
);
2392 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2394 /* Clean up old contents. */
2395 clear_internalvar (var
);
2397 var
->kind
= INTERNALVAR_FUNCTION
;
2398 var
->u
.fn
.function
= f
;
2399 var
->u
.fn
.canonical
= 1;
2400 /* Variables installed here are always the canonical version. */
2404 clear_internalvar (struct internalvar
*var
)
2406 /* Clean up old contents. */
2409 case INTERNALVAR_VALUE
:
2410 value_decref (var
->u
.value
);
2413 case INTERNALVAR_STRING
:
2414 xfree (var
->u
.string
);
2417 case INTERNALVAR_MAKE_VALUE
:
2418 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2419 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2426 /* Reset to void kind. */
2427 var
->kind
= INTERNALVAR_VOID
;
2431 internalvar_name (const struct internalvar
*var
)
2436 static struct internal_function
*
2437 create_internal_function (const char *name
,
2438 internal_function_fn handler
, void *cookie
)
2440 struct internal_function
*ifn
= XNEW (struct internal_function
);
2442 ifn
->name
= xstrdup (name
);
2443 ifn
->handler
= handler
;
2444 ifn
->cookie
= cookie
;
2449 value_internal_function_name (struct value
*val
)
2451 struct internal_function
*ifn
;
2454 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2455 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2456 gdb_assert (result
);
2462 call_internal_function (struct gdbarch
*gdbarch
,
2463 const struct language_defn
*language
,
2464 struct value
*func
, int argc
, struct value
**argv
)
2466 struct internal_function
*ifn
;
2469 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2470 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2471 gdb_assert (result
);
2473 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2476 /* The 'function' command. This does nothing -- it is just a
2477 placeholder to let "help function NAME" work. This is also used as
2478 the implementation of the sub-command that is created when
2479 registering an internal function. */
2481 function_command (const char *command
, int from_tty
)
2486 /* Clean up if an internal function's command is destroyed. */
2488 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2490 xfree ((char *) self
->name
);
2491 xfree ((char *) self
->doc
);
2494 /* Add a new internal function. NAME is the name of the function; DOC
2495 is a documentation string describing the function. HANDLER is
2496 called when the function is invoked. COOKIE is an arbitrary
2497 pointer which is passed to HANDLER and is intended for "user
2500 add_internal_function (const char *name
, const char *doc
,
2501 internal_function_fn handler
, void *cookie
)
2503 struct cmd_list_element
*cmd
;
2504 struct internal_function
*ifn
;
2505 struct internalvar
*var
= lookup_internalvar (name
);
2507 ifn
= create_internal_function (name
, handler
, cookie
);
2508 set_internalvar_function (var
, ifn
);
2510 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2512 cmd
->destroyer
= function_destroyer
;
2515 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2516 prevent cycles / duplicates. */
2519 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2520 htab_t copied_types
)
2522 if (TYPE_OBJFILE (value
->type
) == objfile
)
2523 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2525 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2526 value
->enclosing_type
= copy_type_recursive (objfile
,
2527 value
->enclosing_type
,
2531 /* Likewise for internal variable VAR. */
2534 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2535 htab_t copied_types
)
2539 case INTERNALVAR_INTEGER
:
2540 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2542 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2545 case INTERNALVAR_VALUE
:
2546 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2551 /* Update the internal variables and value history when OBJFILE is
2552 discarded; we must copy the types out of the objfile. New global types
2553 will be created for every convenience variable which currently points to
2554 this objfile's types, and the convenience variables will be adjusted to
2555 use the new global types. */
2558 preserve_values (struct objfile
*objfile
)
2560 htab_t copied_types
;
2561 struct internalvar
*var
;
2564 /* Create the hash table. We allocate on the objfile's obstack, since
2565 it is soon to be deleted. */
2566 copied_types
= create_copied_types_hash (objfile
);
2568 for (const value_ref_ptr
&item
: value_history
)
2569 preserve_one_value (item
.get (), objfile
, copied_types
);
2571 for (var
= internalvars
; var
; var
= var
->next
)
2572 preserve_one_internalvar (var
, objfile
, copied_types
);
2574 preserve_ext_lang_values (objfile
, copied_types
);
2576 htab_delete (copied_types
);
2580 show_convenience (const char *ignore
, int from_tty
)
2582 struct gdbarch
*gdbarch
= get_current_arch ();
2583 struct internalvar
*var
;
2585 struct value_print_options opts
;
2587 get_user_print_options (&opts
);
2588 for (var
= internalvars
; var
; var
= var
->next
)
2595 printf_filtered (("$%s = "), var
->name
);
2601 val
= value_of_internalvar (gdbarch
, var
);
2602 value_print (val
, gdb_stdout
, &opts
);
2604 CATCH (ex
, RETURN_MASK_ERROR
)
2606 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2610 printf_filtered (("\n"));
2614 /* This text does not mention convenience functions on purpose.
2615 The user can't create them except via Python, and if Python support
2616 is installed this message will never be printed ($_streq will
2618 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2619 "Convenience variables have "
2620 "names starting with \"$\";\n"
2621 "use \"set\" as in \"set "
2622 "$foo = 5\" to define them.\n"));
2630 value_from_xmethod (xmethod_worker_up
&&worker
)
2634 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2635 v
->lval
= lval_xcallable
;
2636 v
->location
.xm_worker
= worker
.release ();
2642 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2645 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2647 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2648 && method
->lval
== lval_xcallable
&& argc
> 0);
2650 return method
->location
.xm_worker
->get_result_type
2651 (argv
[0], argv
+ 1, argc
- 1);
2654 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2657 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2659 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2660 && method
->lval
== lval_xcallable
&& argc
> 0);
2662 return method
->location
.xm_worker
->invoke (argv
[0], argv
+ 1, argc
- 1);
2665 /* Extract a value as a C number (either long or double).
2666 Knows how to convert fixed values to double, or
2667 floating values to long.
2668 Does not deallocate the value. */
2671 value_as_long (struct value
*val
)
2673 /* This coerces arrays and functions, which is necessary (e.g.
2674 in disassemble_command). It also dereferences references, which
2675 I suspect is the most logical thing to do. */
2676 val
= coerce_array (val
);
2677 return unpack_long (value_type (val
), value_contents (val
));
2680 /* Extract a value as a C pointer. Does not deallocate the value.
2681 Note that val's type may not actually be a pointer; value_as_long
2682 handles all the cases. */
2684 value_as_address (struct value
*val
)
2686 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2688 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2689 whether we want this to be true eventually. */
2691 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2692 non-address (e.g. argument to "signal", "info break", etc.), or
2693 for pointers to char, in which the low bits *are* significant. */
2694 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2697 /* There are several targets (IA-64, PowerPC, and others) which
2698 don't represent pointers to functions as simply the address of
2699 the function's entry point. For example, on the IA-64, a
2700 function pointer points to a two-word descriptor, generated by
2701 the linker, which contains the function's entry point, and the
2702 value the IA-64 "global pointer" register should have --- to
2703 support position-independent code. The linker generates
2704 descriptors only for those functions whose addresses are taken.
2706 On such targets, it's difficult for GDB to convert an arbitrary
2707 function address into a function pointer; it has to either find
2708 an existing descriptor for that function, or call malloc and
2709 build its own. On some targets, it is impossible for GDB to
2710 build a descriptor at all: the descriptor must contain a jump
2711 instruction; data memory cannot be executed; and code memory
2714 Upon entry to this function, if VAL is a value of type `function'
2715 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2716 value_address (val) is the address of the function. This is what
2717 you'll get if you evaluate an expression like `main'. The call
2718 to COERCE_ARRAY below actually does all the usual unary
2719 conversions, which includes converting values of type `function'
2720 to `pointer to function'. This is the challenging conversion
2721 discussed above. Then, `unpack_long' will convert that pointer
2722 back into an address.
2724 So, suppose the user types `disassemble foo' on an architecture
2725 with a strange function pointer representation, on which GDB
2726 cannot build its own descriptors, and suppose further that `foo'
2727 has no linker-built descriptor. The address->pointer conversion
2728 will signal an error and prevent the command from running, even
2729 though the next step would have been to convert the pointer
2730 directly back into the same address.
2732 The following shortcut avoids this whole mess. If VAL is a
2733 function, just return its address directly. */
2734 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2735 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2736 return value_address (val
);
2738 val
= coerce_array (val
);
2740 /* Some architectures (e.g. Harvard), map instruction and data
2741 addresses onto a single large unified address space. For
2742 instance: An architecture may consider a large integer in the
2743 range 0x10000000 .. 0x1000ffff to already represent a data
2744 addresses (hence not need a pointer to address conversion) while
2745 a small integer would still need to be converted integer to
2746 pointer to address. Just assume such architectures handle all
2747 integer conversions in a single function. */
2751 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2752 must admonish GDB hackers to make sure its behavior matches the
2753 compiler's, whenever possible.
2755 In general, I think GDB should evaluate expressions the same way
2756 the compiler does. When the user copies an expression out of
2757 their source code and hands it to a `print' command, they should
2758 get the same value the compiler would have computed. Any
2759 deviation from this rule can cause major confusion and annoyance,
2760 and needs to be justified carefully. In other words, GDB doesn't
2761 really have the freedom to do these conversions in clever and
2764 AndrewC pointed out that users aren't complaining about how GDB
2765 casts integers to pointers; they are complaining that they can't
2766 take an address from a disassembly listing and give it to `x/i'.
2767 This is certainly important.
2769 Adding an architecture method like integer_to_address() certainly
2770 makes it possible for GDB to "get it right" in all circumstances
2771 --- the target has complete control over how things get done, so
2772 people can Do The Right Thing for their target without breaking
2773 anyone else. The standard doesn't specify how integers get
2774 converted to pointers; usually, the ABI doesn't either, but
2775 ABI-specific code is a more reasonable place to handle it. */
2777 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2778 && !TYPE_IS_REFERENCE (value_type (val
))
2779 && gdbarch_integer_to_address_p (gdbarch
))
2780 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2781 value_contents (val
));
2783 return unpack_long (value_type (val
), value_contents (val
));
2787 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2788 as a long, or as a double, assuming the raw data is described
2789 by type TYPE. Knows how to convert different sizes of values
2790 and can convert between fixed and floating point. We don't assume
2791 any alignment for the raw data. Return value is in host byte order.
2793 If you want functions and arrays to be coerced to pointers, and
2794 references to be dereferenced, call value_as_long() instead.
2796 C++: It is assumed that the front-end has taken care of
2797 all matters concerning pointers to members. A pointer
2798 to member which reaches here is considered to be equivalent
2799 to an INT (or some size). After all, it is only an offset. */
2802 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2804 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2805 enum type_code code
= TYPE_CODE (type
);
2806 int len
= TYPE_LENGTH (type
);
2807 int nosign
= TYPE_UNSIGNED (type
);
2811 case TYPE_CODE_TYPEDEF
:
2812 return unpack_long (check_typedef (type
), valaddr
);
2813 case TYPE_CODE_ENUM
:
2814 case TYPE_CODE_FLAGS
:
2815 case TYPE_CODE_BOOL
:
2817 case TYPE_CODE_CHAR
:
2818 case TYPE_CODE_RANGE
:
2819 case TYPE_CODE_MEMBERPTR
:
2821 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2823 return extract_signed_integer (valaddr
, len
, byte_order
);
2826 case TYPE_CODE_DECFLOAT
:
2827 return target_float_to_longest (valaddr
, type
);
2831 case TYPE_CODE_RVALUE_REF
:
2832 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2833 whether we want this to be true eventually. */
2834 return extract_typed_address (valaddr
, type
);
2837 error (_("Value can't be converted to integer."));
2839 return 0; /* Placate lint. */
2842 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2843 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2844 We don't assume any alignment for the raw data. Return value is in
2847 If you want functions and arrays to be coerced to pointers, and
2848 references to be dereferenced, call value_as_address() instead.
2850 C++: It is assumed that the front-end has taken care of
2851 all matters concerning pointers to members. A pointer
2852 to member which reaches here is considered to be equivalent
2853 to an INT (or some size). After all, it is only an offset. */
2856 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2858 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2859 whether we want this to be true eventually. */
2860 return unpack_long (type
, valaddr
);
2864 is_floating_value (struct value
*val
)
2866 struct type
*type
= check_typedef (value_type (val
));
2868 if (is_floating_type (type
))
2870 if (!target_float_is_valid (value_contents (val
), type
))
2871 error (_("Invalid floating value found in program."));
2879 /* Get the value of the FIELDNO'th field (which must be static) of
2883 value_static_field (struct type
*type
, int fieldno
)
2885 struct value
*retval
;
2887 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2889 case FIELD_LOC_KIND_PHYSADDR
:
2890 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2891 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2893 case FIELD_LOC_KIND_PHYSNAME
:
2895 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2896 /* TYPE_FIELD_NAME (type, fieldno); */
2897 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2899 if (sym
.symbol
== NULL
)
2901 /* With some compilers, e.g. HP aCC, static data members are
2902 reported as non-debuggable symbols. */
2903 struct bound_minimal_symbol msym
2904 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2905 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2908 retval
= allocate_optimized_out_value (field_type
);
2910 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2913 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2917 gdb_assert_not_reached ("unexpected field location kind");
2923 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2924 You have to be careful here, since the size of the data area for the value
2925 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2926 than the old enclosing type, you have to allocate more space for the
2930 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2932 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2934 check_type_length_before_alloc (new_encl_type
);
2936 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2939 val
->enclosing_type
= new_encl_type
;
2942 /* Given a value ARG1 (offset by OFFSET bytes)
2943 of a struct or union type ARG_TYPE,
2944 extract and return the value of one of its (non-static) fields.
2945 FIELDNO says which field. */
2948 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2949 int fieldno
, struct type
*arg_type
)
2953 struct gdbarch
*arch
= get_value_arch (arg1
);
2954 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2956 arg_type
= check_typedef (arg_type
);
2957 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2959 /* Call check_typedef on our type to make sure that, if TYPE
2960 is a TYPE_CODE_TYPEDEF, its length is set to the length
2961 of the target type instead of zero. However, we do not
2962 replace the typedef type by the target type, because we want
2963 to keep the typedef in order to be able to print the type
2964 description correctly. */
2965 check_typedef (type
);
2967 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2969 /* Handle packed fields.
2971 Create a new value for the bitfield, with bitpos and bitsize
2972 set. If possible, arrange offset and bitpos so that we can
2973 do a single aligned read of the size of the containing type.
2974 Otherwise, adjust offset to the byte containing the first
2975 bit. Assume that the address, offset, and embedded offset
2976 are sufficiently aligned. */
2978 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2979 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2981 v
= allocate_value_lazy (type
);
2982 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2983 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2984 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2985 v
->bitpos
= bitpos
% container_bitsize
;
2987 v
->bitpos
= bitpos
% 8;
2988 v
->offset
= (value_embedded_offset (arg1
)
2990 + (bitpos
- v
->bitpos
) / 8);
2991 set_value_parent (v
, arg1
);
2992 if (!value_lazy (arg1
))
2993 value_fetch_lazy (v
);
2995 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2997 /* This field is actually a base subobject, so preserve the
2998 entire object's contents for later references to virtual
3002 /* Lazy register values with offsets are not supported. */
3003 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3004 value_fetch_lazy (arg1
);
3006 /* We special case virtual inheritance here because this
3007 requires access to the contents, which we would rather avoid
3008 for references to ordinary fields of unavailable values. */
3009 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3010 boffset
= baseclass_offset (arg_type
, fieldno
,
3011 value_contents (arg1
),
3012 value_embedded_offset (arg1
),
3013 value_address (arg1
),
3016 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3018 if (value_lazy (arg1
))
3019 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3022 v
= allocate_value (value_enclosing_type (arg1
));
3023 value_contents_copy_raw (v
, 0, arg1
, 0,
3024 TYPE_LENGTH (value_enclosing_type (arg1
)));
3027 v
->offset
= value_offset (arg1
);
3028 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3030 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3032 /* Field is a dynamic data member. */
3034 gdb_assert (0 == offset
);
3035 /* We expect an already resolved data location. */
3036 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3037 /* For dynamic data types defer memory allocation
3038 until we actual access the value. */
3039 v
= allocate_value_lazy (type
);
3043 /* Plain old data member */
3044 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3045 / (HOST_CHAR_BIT
* unit_size
));
3047 /* Lazy register values with offsets are not supported. */
3048 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3049 value_fetch_lazy (arg1
);
3051 if (value_lazy (arg1
))
3052 v
= allocate_value_lazy (type
);
3055 v
= allocate_value (type
);
3056 value_contents_copy_raw (v
, value_embedded_offset (v
),
3057 arg1
, value_embedded_offset (arg1
) + offset
,
3058 type_length_units (type
));
3060 v
->offset
= (value_offset (arg1
) + offset
3061 + value_embedded_offset (arg1
));
3063 set_value_component_location (v
, arg1
);
3067 /* Given a value ARG1 of a struct or union type,
3068 extract and return the value of one of its (non-static) fields.
3069 FIELDNO says which field. */
3072 value_field (struct value
*arg1
, int fieldno
)
3074 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3077 /* Return a non-virtual function as a value.
3078 F is the list of member functions which contains the desired method.
3079 J is an index into F which provides the desired method.
3081 We only use the symbol for its address, so be happy with either a
3082 full symbol or a minimal symbol. */
3085 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3086 int j
, struct type
*type
,
3090 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3091 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3093 struct bound_minimal_symbol msym
;
3095 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3098 memset (&msym
, 0, sizeof (msym
));
3102 gdb_assert (sym
== NULL
);
3103 msym
= lookup_bound_minimal_symbol (physname
);
3104 if (msym
.minsym
== NULL
)
3108 v
= allocate_value (ftype
);
3109 VALUE_LVAL (v
) = lval_memory
;
3112 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3116 /* The minimal symbol might point to a function descriptor;
3117 resolve it to the actual code address instead. */
3118 struct objfile
*objfile
= msym
.objfile
;
3119 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3121 set_value_address (v
,
3122 gdbarch_convert_from_func_ptr_addr
3123 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3128 if (type
!= value_type (*arg1p
))
3129 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3130 value_addr (*arg1p
)));
3132 /* Move the `this' pointer according to the offset.
3133 VALUE_OFFSET (*arg1p) += offset; */
3141 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3142 VALADDR, and store the result in *RESULT.
3143 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3144 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3146 Extracting bits depends on endianness of the machine. Compute the
3147 number of least significant bits to discard. For big endian machines,
3148 we compute the total number of bits in the anonymous object, subtract
3149 off the bit count from the MSB of the object to the MSB of the
3150 bitfield, then the size of the bitfield, which leaves the LSB discard
3151 count. For little endian machines, the discard count is simply the
3152 number of bits from the LSB of the anonymous object to the LSB of the
3155 If the field is signed, we also do sign extension. */
3158 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3159 LONGEST bitpos
, LONGEST bitsize
)
3161 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3166 LONGEST read_offset
;
3168 /* Read the minimum number of bytes required; there may not be
3169 enough bytes to read an entire ULONGEST. */
3170 field_type
= check_typedef (field_type
);
3172 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3175 bytes_read
= TYPE_LENGTH (field_type
);
3176 bitsize
= 8 * bytes_read
;
3179 read_offset
= bitpos
/ 8;
3181 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3182 bytes_read
, byte_order
);
3184 /* Extract bits. See comment above. */
3186 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3187 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3189 lsbcount
= (bitpos
% 8);
3192 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3193 If the field is signed, and is negative, then sign extend. */
3195 if (bitsize
< 8 * (int) sizeof (val
))
3197 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3199 if (!TYPE_UNSIGNED (field_type
))
3201 if (val
& (valmask
^ (valmask
>> 1)))
3211 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3212 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3213 ORIGINAL_VALUE, which must not be NULL. See
3214 unpack_value_bits_as_long for more details. */
3217 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3218 LONGEST embedded_offset
, int fieldno
,
3219 const struct value
*val
, LONGEST
*result
)
3221 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3222 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3223 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3226 gdb_assert (val
!= NULL
);
3228 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3229 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3230 || !value_bits_available (val
, bit_offset
, bitsize
))
3233 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3238 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3239 object at VALADDR. See unpack_bits_as_long for more details. */
3242 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3244 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3245 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3246 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3248 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3251 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3252 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3253 the contents in DEST_VAL, zero or sign extending if the type of
3254 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3255 VAL. If the VAL's contents required to extract the bitfield from
3256 are unavailable/optimized out, DEST_VAL is correspondingly
3257 marked unavailable/optimized out. */
3260 unpack_value_bitfield (struct value
*dest_val
,
3261 LONGEST bitpos
, LONGEST bitsize
,
3262 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3263 const struct value
*val
)
3265 enum bfd_endian byte_order
;
3268 struct type
*field_type
= value_type (dest_val
);
3270 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3272 /* First, unpack and sign extend the bitfield as if it was wholly
3273 valid. Optimized out/unavailable bits are read as zero, but
3274 that's OK, as they'll end up marked below. If the VAL is
3275 wholly-invalid we may have skipped allocating its contents,
3276 though. See allocate_optimized_out_value. */
3277 if (valaddr
!= NULL
)
3281 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3283 store_signed_integer (value_contents_raw (dest_val
),
3284 TYPE_LENGTH (field_type
), byte_order
, num
);
3287 /* Now copy the optimized out / unavailability ranges to the right
3289 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3290 if (byte_order
== BFD_ENDIAN_BIG
)
3291 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3294 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3295 val
, src_bit_offset
, bitsize
);
3298 /* Return a new value with type TYPE, which is FIELDNO field of the
3299 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3300 of VAL. If the VAL's contents required to extract the bitfield
3301 from are unavailable/optimized out, the new value is
3302 correspondingly marked unavailable/optimized out. */
3305 value_field_bitfield (struct type
*type
, int fieldno
,
3306 const gdb_byte
*valaddr
,
3307 LONGEST embedded_offset
, const struct value
*val
)
3309 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3310 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3311 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3313 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3314 valaddr
, embedded_offset
, val
);
3319 /* Modify the value of a bitfield. ADDR points to a block of memory in
3320 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3321 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3322 indicate which bits (in target bit order) comprise the bitfield.
3323 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3324 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3327 modify_field (struct type
*type
, gdb_byte
*addr
,
3328 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3330 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3332 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3335 /* Normalize BITPOS. */
3339 /* If a negative fieldval fits in the field in question, chop
3340 off the sign extension bits. */
3341 if ((~fieldval
& ~(mask
>> 1)) == 0)
3344 /* Warn if value is too big to fit in the field in question. */
3345 if (0 != (fieldval
& ~mask
))
3347 /* FIXME: would like to include fieldval in the message, but
3348 we don't have a sprintf_longest. */
3349 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3351 /* Truncate it, otherwise adjoining fields may be corrupted. */
3355 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3356 false valgrind reports. */
3358 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3359 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3361 /* Shifting for bit field depends on endianness of the target machine. */
3362 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3363 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3365 oword
&= ~(mask
<< bitpos
);
3366 oword
|= fieldval
<< bitpos
;
3368 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3371 /* Pack NUM into BUF using a target format of TYPE. */
3374 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3376 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3379 type
= check_typedef (type
);
3380 len
= TYPE_LENGTH (type
);
3382 switch (TYPE_CODE (type
))
3385 case TYPE_CODE_CHAR
:
3386 case TYPE_CODE_ENUM
:
3387 case TYPE_CODE_FLAGS
:
3388 case TYPE_CODE_BOOL
:
3389 case TYPE_CODE_RANGE
:
3390 case TYPE_CODE_MEMBERPTR
:
3391 store_signed_integer (buf
, len
, byte_order
, num
);
3395 case TYPE_CODE_RVALUE_REF
:
3397 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3401 case TYPE_CODE_DECFLOAT
:
3402 target_float_from_longest (buf
, type
, num
);
3406 error (_("Unexpected type (%d) encountered for integer constant."),
3412 /* Pack NUM into BUF using a target format of TYPE. */
3415 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3418 enum bfd_endian byte_order
;
3420 type
= check_typedef (type
);
3421 len
= TYPE_LENGTH (type
);
3422 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3424 switch (TYPE_CODE (type
))
3427 case TYPE_CODE_CHAR
:
3428 case TYPE_CODE_ENUM
:
3429 case TYPE_CODE_FLAGS
:
3430 case TYPE_CODE_BOOL
:
3431 case TYPE_CODE_RANGE
:
3432 case TYPE_CODE_MEMBERPTR
:
3433 store_unsigned_integer (buf
, len
, byte_order
, num
);
3437 case TYPE_CODE_RVALUE_REF
:
3439 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3443 case TYPE_CODE_DECFLOAT
:
3444 target_float_from_ulongest (buf
, type
, num
);
3448 error (_("Unexpected type (%d) encountered "
3449 "for unsigned integer constant."),
3455 /* Convert C numbers into newly allocated values. */
3458 value_from_longest (struct type
*type
, LONGEST num
)
3460 struct value
*val
= allocate_value (type
);
3462 pack_long (value_contents_raw (val
), type
, num
);
3467 /* Convert C unsigned numbers into newly allocated values. */
3470 value_from_ulongest (struct type
*type
, ULONGEST num
)
3472 struct value
*val
= allocate_value (type
);
3474 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3480 /* Create a value representing a pointer of type TYPE to the address
3484 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3486 struct value
*val
= allocate_value (type
);
3488 store_typed_address (value_contents_raw (val
),
3489 check_typedef (type
), addr
);
3494 /* Create a value of type TYPE whose contents come from VALADDR, if it
3495 is non-null, and whose memory address (in the inferior) is
3496 ADDRESS. The type of the created value may differ from the passed
3497 type TYPE. Make sure to retrieve values new type after this call.
3498 Note that TYPE is not passed through resolve_dynamic_type; this is
3499 a special API intended for use only by Ada. */
3502 value_from_contents_and_address_unresolved (struct type
*type
,
3503 const gdb_byte
*valaddr
,
3508 if (valaddr
== NULL
)
3509 v
= allocate_value_lazy (type
);
3511 v
= value_from_contents (type
, valaddr
);
3512 VALUE_LVAL (v
) = lval_memory
;
3513 set_value_address (v
, address
);
3517 /* Create a value of type TYPE whose contents come from VALADDR, if it
3518 is non-null, and whose memory address (in the inferior) is
3519 ADDRESS. The type of the created value may differ from the passed
3520 type TYPE. Make sure to retrieve values new type after this call. */
3523 value_from_contents_and_address (struct type
*type
,
3524 const gdb_byte
*valaddr
,
3527 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3528 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3531 if (valaddr
== NULL
)
3532 v
= allocate_value_lazy (resolved_type
);
3534 v
= value_from_contents (resolved_type
, valaddr
);
3535 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3536 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3537 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3538 VALUE_LVAL (v
) = lval_memory
;
3539 set_value_address (v
, address
);
3543 /* Create a value of type TYPE holding the contents CONTENTS.
3544 The new value is `not_lval'. */
3547 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3549 struct value
*result
;
3551 result
= allocate_value (type
);
3552 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3556 /* Extract a value from the history file. Input will be of the form
3557 $digits or $$digits. See block comment above 'write_dollar_variable'
3561 value_from_history_ref (const char *h
, const char **endp
)
3573 /* Find length of numeral string. */
3574 for (; isdigit (h
[len
]); len
++)
3577 /* Make sure numeral string is not part of an identifier. */
3578 if (h
[len
] == '_' || isalpha (h
[len
]))
3581 /* Now collect the index value. */
3586 /* For some bizarre reason, "$$" is equivalent to "$$1",
3587 rather than to "$$0" as it ought to be! */
3595 index
= -strtol (&h
[2], &local_end
, 10);
3603 /* "$" is equivalent to "$0". */
3611 index
= strtol (&h
[1], &local_end
, 10);
3616 return access_value_history (index
);
3619 /* Get the component value (offset by OFFSET bytes) of a struct or
3620 union WHOLE. Component's type is TYPE. */
3623 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3627 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3628 v
= allocate_value_lazy (type
);
3631 v
= allocate_value (type
);
3632 value_contents_copy (v
, value_embedded_offset (v
),
3633 whole
, value_embedded_offset (whole
) + offset
,
3634 type_length_units (type
));
3636 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3637 set_value_component_location (v
, whole
);
3643 coerce_ref_if_computed (const struct value
*arg
)
3645 const struct lval_funcs
*funcs
;
3647 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3650 if (value_lval_const (arg
) != lval_computed
)
3653 funcs
= value_computed_funcs (arg
);
3654 if (funcs
->coerce_ref
== NULL
)
3657 return funcs
->coerce_ref (arg
);
3660 /* Look at value.h for description. */
3663 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3664 const struct type
*original_type
,
3665 const struct value
*original_value
)
3667 /* Re-adjust type. */
3668 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3670 /* Add embedding info. */
3671 set_value_enclosing_type (value
, enc_type
);
3672 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3674 /* We may be pointing to an object of some derived type. */
3675 return value_full_object (value
, NULL
, 0, 0, 0);
3679 coerce_ref (struct value
*arg
)
3681 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3682 struct value
*retval
;
3683 struct type
*enc_type
;
3685 retval
= coerce_ref_if_computed (arg
);
3689 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3692 enc_type
= check_typedef (value_enclosing_type (arg
));
3693 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3695 retval
= value_at_lazy (enc_type
,
3696 unpack_pointer (value_type (arg
),
3697 value_contents (arg
)));
3698 enc_type
= value_type (retval
);
3699 return readjust_indirect_value_type (retval
, enc_type
,
3700 value_type_arg_tmp
, arg
);
3704 coerce_array (struct value
*arg
)
3708 arg
= coerce_ref (arg
);
3709 type
= check_typedef (value_type (arg
));
3711 switch (TYPE_CODE (type
))
3713 case TYPE_CODE_ARRAY
:
3714 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3715 arg
= value_coerce_array (arg
);
3717 case TYPE_CODE_FUNC
:
3718 arg
= value_coerce_function (arg
);
3725 /* Return the return value convention that will be used for the
3728 enum return_value_convention
3729 struct_return_convention (struct gdbarch
*gdbarch
,
3730 struct value
*function
, struct type
*value_type
)
3732 enum type_code code
= TYPE_CODE (value_type
);
3734 if (code
== TYPE_CODE_ERROR
)
3735 error (_("Function return type unknown."));
3737 /* Probe the architecture for the return-value convention. */
3738 return gdbarch_return_value (gdbarch
, function
, value_type
,
3742 /* Return true if the function returning the specified type is using
3743 the convention of returning structures in memory (passing in the
3744 address as a hidden first parameter). */
3747 using_struct_return (struct gdbarch
*gdbarch
,
3748 struct value
*function
, struct type
*value_type
)
3750 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3751 /* A void return value is never in memory. See also corresponding
3752 code in "print_return_value". */
3755 return (struct_return_convention (gdbarch
, function
, value_type
)
3756 != RETURN_VALUE_REGISTER_CONVENTION
);
3759 /* Set the initialized field in a value struct. */
3762 set_value_initialized (struct value
*val
, int status
)
3764 val
->initialized
= status
;
3767 /* Return the initialized field in a value struct. */
3770 value_initialized (const struct value
*val
)
3772 return val
->initialized
;
3775 /* Load the actual content of a lazy value. Fetch the data from the
3776 user's process and clear the lazy flag to indicate that the data in
3777 the buffer is valid.
3779 If the value is zero-length, we avoid calling read_memory, which
3780 would abort. We mark the value as fetched anyway -- all 0 bytes of
3784 value_fetch_lazy (struct value
*val
)
3786 gdb_assert (value_lazy (val
));
3787 allocate_value_contents (val
);
3788 /* A value is either lazy, or fully fetched. The
3789 availability/validity is only established as we try to fetch a
3791 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3792 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3793 if (value_bitsize (val
))
3795 /* To read a lazy bitfield, read the entire enclosing value. This
3796 prevents reading the same block of (possibly volatile) memory once
3797 per bitfield. It would be even better to read only the containing
3798 word, but we have no way to record that just specific bits of a
3799 value have been fetched. */
3800 struct type
*type
= check_typedef (value_type (val
));
3801 struct value
*parent
= value_parent (val
);
3803 if (value_lazy (parent
))
3804 value_fetch_lazy (parent
);
3806 unpack_value_bitfield (val
,
3807 value_bitpos (val
), value_bitsize (val
),
3808 value_contents_for_printing (parent
),
3809 value_offset (val
), parent
);
3811 else if (VALUE_LVAL (val
) == lval_memory
)
3813 CORE_ADDR addr
= value_address (val
);
3814 struct type
*type
= check_typedef (value_enclosing_type (val
));
3816 if (TYPE_LENGTH (type
))
3817 read_value_memory (val
, 0, value_stack (val
),
3818 addr
, value_contents_all_raw (val
),
3819 type_length_units (type
));
3821 else if (VALUE_LVAL (val
) == lval_register
)
3823 struct frame_info
*next_frame
;
3825 struct type
*type
= check_typedef (value_type (val
));
3826 struct value
*new_val
= val
, *mark
= value_mark ();
3828 /* Offsets are not supported here; lazy register values must
3829 refer to the entire register. */
3830 gdb_assert (value_offset (val
) == 0);
3832 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3834 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3836 next_frame
= frame_find_by_id (next_frame_id
);
3837 regnum
= VALUE_REGNUM (new_val
);
3839 gdb_assert (next_frame
!= NULL
);
3841 /* Convertible register routines are used for multi-register
3842 values and for interpretation in different types
3843 (e.g. float or int from a double register). Lazy
3844 register values should have the register's natural type,
3845 so they do not apply. */
3846 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3849 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3850 Since a "->next" operation was performed when setting
3851 this field, we do not need to perform a "next" operation
3852 again when unwinding the register. That's why
3853 frame_unwind_register_value() is called here instead of
3854 get_frame_register_value(). */
3855 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3857 /* If we get another lazy lval_register value, it means the
3858 register is found by reading it from NEXT_FRAME's next frame.
3859 frame_unwind_register_value should never return a value with
3860 the frame id pointing to NEXT_FRAME. If it does, it means we
3861 either have two consecutive frames with the same frame id
3862 in the frame chain, or some code is trying to unwind
3863 behind get_prev_frame's back (e.g., a frame unwind
3864 sniffer trying to unwind), bypassing its validations. In
3865 any case, it should always be an internal error to end up
3866 in this situation. */
3867 if (VALUE_LVAL (new_val
) == lval_register
3868 && value_lazy (new_val
)
3869 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3870 internal_error (__FILE__
, __LINE__
,
3871 _("infinite loop while fetching a register"));
3874 /* If it's still lazy (for instance, a saved register on the
3875 stack), fetch it. */
3876 if (value_lazy (new_val
))
3877 value_fetch_lazy (new_val
);
3879 /* Copy the contents and the unavailability/optimized-out
3880 meta-data from NEW_VAL to VAL. */
3881 set_value_lazy (val
, 0);
3882 value_contents_copy (val
, value_embedded_offset (val
),
3883 new_val
, value_embedded_offset (new_val
),
3884 type_length_units (type
));
3888 struct gdbarch
*gdbarch
;
3889 struct frame_info
*frame
;
3890 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3891 so that the frame level will be shown correctly. */
3892 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3893 regnum
= VALUE_REGNUM (val
);
3894 gdbarch
= get_frame_arch (frame
);
3896 fprintf_unfiltered (gdb_stdlog
,
3897 "{ value_fetch_lazy "
3898 "(frame=%d,regnum=%d(%s),...) ",
3899 frame_relative_level (frame
), regnum
,
3900 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3902 fprintf_unfiltered (gdb_stdlog
, "->");
3903 if (value_optimized_out (new_val
))
3905 fprintf_unfiltered (gdb_stdlog
, " ");
3906 val_print_optimized_out (new_val
, gdb_stdlog
);
3911 const gdb_byte
*buf
= value_contents (new_val
);
3913 if (VALUE_LVAL (new_val
) == lval_register
)
3914 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3915 VALUE_REGNUM (new_val
));
3916 else if (VALUE_LVAL (new_val
) == lval_memory
)
3917 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3919 value_address (new_val
)));
3921 fprintf_unfiltered (gdb_stdlog
, " computed");
3923 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3924 fprintf_unfiltered (gdb_stdlog
, "[");
3925 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3926 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3927 fprintf_unfiltered (gdb_stdlog
, "]");
3930 fprintf_unfiltered (gdb_stdlog
, " }\n");
3933 /* Dispose of the intermediate values. This prevents
3934 watchpoints from trying to watch the saved frame pointer. */
3935 value_free_to_mark (mark
);
3937 else if (VALUE_LVAL (val
) == lval_computed
3938 && value_computed_funcs (val
)->read
!= NULL
)
3939 value_computed_funcs (val
)->read (val
);
3941 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3943 set_value_lazy (val
, 0);
3946 /* Implementation of the convenience function $_isvoid. */
3948 static struct value
*
3949 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3950 const struct language_defn
*language
,
3951 void *cookie
, int argc
, struct value
**argv
)
3956 error (_("You must provide one argument for $_isvoid."));
3958 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3960 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3964 _initialize_values (void)
3966 add_cmd ("convenience", no_class
, show_convenience
, _("\
3967 Debugger convenience (\"$foo\") variables and functions.\n\
3968 Convenience variables are created when you assign them values;\n\
3969 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3971 A few convenience variables are given values automatically:\n\
3972 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3973 \"$__\" holds the contents of the last address examined with \"x\"."
3976 Convenience functions are defined via the Python API."
3979 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3981 add_cmd ("values", no_set_class
, show_values
, _("\
3982 Elements of value history around item number IDX (or last ten)."),
3985 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3986 Initialize a convenience variable if necessary.\n\
3987 init-if-undefined VARIABLE = EXPRESSION\n\
3988 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3989 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3990 VARIABLE is already initialized."));
3992 add_prefix_cmd ("function", no_class
, function_command
, _("\
3993 Placeholder command for showing help on convenience functions."),
3994 &functionlist
, "function ", 0, &cmdlist
);
3996 add_internal_function ("_isvoid", _("\
3997 Check whether an expression is void.\n\
3998 Usage: $_isvoid (expression)\n\
3999 Return 1 if the expression is void, zero otherwise."),
4000 isvoid_internal_fn
, NULL
);
4002 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4003 class_support
, &max_value_size
, _("\
4004 Set maximum sized value gdb will load from the inferior."), _("\
4005 Show maximum sized value gdb will load from the inferior."), _("\
4006 Use this to control the maximum size, in bytes, of a value that gdb\n\
4007 will load from the inferior. Setting this value to 'unlimited'\n\
4008 disables checking.\n\
4009 Setting this does not invalidate already allocated values, it only\n\
4010 prevents future values, larger than this size, from being allocated."),
4012 show_max_value_size
,
4013 &setlist
, &showlist
);