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 #include "common/array-view.h"
47 /* Definition of a user function. */
48 struct internal_function
50 /* The name of the function. It is a bit odd to have this in the
51 function itself -- the user might use a differently-named
52 convenience variable to hold the function. */
56 internal_function_fn handler
;
58 /* User data for the handler. */
62 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
66 /* Lowest offset in the range. */
69 /* Length of the range. */
72 /* Returns true if THIS is strictly less than OTHER, useful for
73 searching. We keep ranges sorted by offset and coalesce
74 overlapping and contiguous ranges, so this just compares the
77 bool operator< (const range
&other
) const
79 return offset
< other
.offset
;
82 /* Returns true if THIS is equal to OTHER. */
83 bool operator== (const range
&other
) const
85 return offset
== other
.offset
&& length
== other
.length
;
89 /* Returns true if the ranges defined by [offset1, offset1+len1) and
90 [offset2, offset2+len2) overlap. */
93 ranges_overlap (LONGEST offset1
, LONGEST len1
,
94 LONGEST offset2
, LONGEST len2
)
98 l
= std::max (offset1
, offset2
);
99 h
= std::min (offset1
+ len1
, offset2
+ len2
);
103 /* Returns true if RANGES contains any range that overlaps [OFFSET,
107 ranges_contain (const std::vector
<range
> &ranges
, LONGEST offset
,
112 what
.offset
= offset
;
113 what
.length
= length
;
115 /* We keep ranges sorted by offset and coalesce overlapping and
116 contiguous ranges, so to check if a range list contains a given
117 range, we can do a binary search for the position the given range
118 would be inserted if we only considered the starting OFFSET of
119 ranges. We call that position I. Since we also have LENGTH to
120 care for (this is a range afterall), we need to check if the
121 _previous_ range overlaps the I range. E.g.,
125 |---| |---| |------| ... |--|
130 In the case above, the binary search would return `I=1', meaning,
131 this OFFSET should be inserted at position 1, and the current
132 position 1 should be pushed further (and before 2). But, `0'
135 Then we need to check if the I range overlaps the I range itself.
140 |---| |---| |-------| ... |--|
147 auto i
= std::lower_bound (ranges
.begin (), ranges
.end (), what
);
149 if (i
> ranges
.begin ())
151 const struct range
&bef
= *(i
- 1);
153 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
157 if (i
< ranges
.end ())
159 const struct range
&r
= *i
;
161 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
168 static struct cmd_list_element
*functionlist
;
170 /* Note that the fields in this structure are arranged to save a bit
175 explicit value (struct type
*type_
)
181 enclosing_type (type_
)
183 location
.address
= 0;
188 if (VALUE_LVAL (this) == lval_computed
)
190 const struct lval_funcs
*funcs
= location
.computed
.funcs
;
192 if (funcs
->free_closure
)
193 funcs
->free_closure (this);
195 else if (VALUE_LVAL (this) == lval_xcallable
)
196 delete location
.xm_worker
;
199 DISABLE_COPY_AND_ASSIGN (value
);
201 /* Type of value; either not an lval, or one of the various
202 different possible kinds of lval. */
203 enum lval_type lval
= not_lval
;
205 /* Is it modifiable? Only relevant if lval != not_lval. */
206 unsigned int modifiable
: 1;
208 /* If zero, contents of this value are in the contents field. If
209 nonzero, contents are in inferior. If the lval field is lval_memory,
210 the contents are in inferior memory at location.address plus offset.
211 The lval field may also be lval_register.
213 WARNING: This field is used by the code which handles watchpoints
214 (see breakpoint.c) to decide whether a particular value can be
215 watched by hardware watchpoints. If the lazy flag is set for
216 some member of a value chain, it is assumed that this member of
217 the chain doesn't need to be watched as part of watching the
218 value itself. This is how GDB avoids watching the entire struct
219 or array when the user wants to watch a single struct member or
220 array element. If you ever change the way lazy flag is set and
221 reset, be sure to consider this use as well! */
222 unsigned int lazy
: 1;
224 /* If value is a variable, is it initialized or not. */
225 unsigned int initialized
: 1;
227 /* If value is from the stack. If this is set, read_stack will be
228 used instead of read_memory to enable extra caching. */
229 unsigned int stack
: 1;
231 /* Location of value (if lval). */
234 /* If lval == lval_memory, this is the address in the inferior */
237 /*If lval == lval_register, the value is from a register. */
240 /* Register number. */
242 /* Frame ID of "next" frame to which a register value is relative.
243 If the register value is found relative to frame F, then the
244 frame id of F->next will be stored in next_frame_id. */
245 struct frame_id next_frame_id
;
248 /* Pointer to internal variable. */
249 struct internalvar
*internalvar
;
251 /* Pointer to xmethod worker. */
252 struct xmethod_worker
*xm_worker
;
254 /* If lval == lval_computed, this is a set of function pointers
255 to use to access and describe the value, and a closure pointer
259 /* Functions to call. */
260 const struct lval_funcs
*funcs
;
262 /* Closure for those functions to use. */
267 /* Describes offset of a value within lval of a structure in target
268 addressable memory units. Note also the member embedded_offset
272 /* Only used for bitfields; number of bits contained in them. */
275 /* Only used for bitfields; position of start of field. For
276 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
277 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
280 /* The number of references to this value. When a value is created,
281 the value chain holds a reference, so REFERENCE_COUNT is 1. If
282 release_value is called, this value is removed from the chain but
283 the caller of release_value now has a reference to this value.
284 The caller must arrange for a call to value_free later. */
285 int reference_count
= 1;
287 /* Only used for bitfields; the containing value. This allows a
288 single read from the target when displaying multiple
290 value_ref_ptr parent
;
292 /* Type of the value. */
295 /* If a value represents a C++ object, then the `type' field gives
296 the object's compile-time type. If the object actually belongs
297 to some class derived from `type', perhaps with other base
298 classes and additional members, then `type' is just a subobject
299 of the real thing, and the full object is probably larger than
300 `type' would suggest.
302 If `type' is a dynamic class (i.e. one with a vtable), then GDB
303 can actually determine the object's run-time type by looking at
304 the run-time type information in the vtable. When this
305 information is available, we may elect to read in the entire
306 object, for several reasons:
308 - When printing the value, the user would probably rather see the
309 full object, not just the limited portion apparent from the
312 - If `type' has virtual base classes, then even printing `type'
313 alone may require reaching outside the `type' portion of the
314 object to wherever the virtual base class has been stored.
316 When we store the entire object, `enclosing_type' is the run-time
317 type -- the complete object -- and `embedded_offset' is the
318 offset of `type' within that larger type, in target addressable memory
319 units. The value_contents() macro takes `embedded_offset' into account,
320 so most GDB code continues to see the `type' portion of the value, just
321 as the inferior would.
323 If `type' is a pointer to an object, then `enclosing_type' is a
324 pointer to the object's run-time type, and `pointed_to_offset' is
325 the offset in target addressable memory units from the full object
326 to the pointed-to object -- that is, the value `embedded_offset' would
327 have if we followed the pointer and fetched the complete object.
328 (I don't really see the point. Why not just determine the
329 run-time type when you indirect, and avoid the special case? The
330 contents don't matter until you indirect anyway.)
332 If we're not doing anything fancy, `enclosing_type' is equal to
333 `type', and `embedded_offset' is zero, so everything works
335 struct type
*enclosing_type
;
336 LONGEST embedded_offset
= 0;
337 LONGEST pointed_to_offset
= 0;
339 /* Actual contents of the value. Target byte-order. NULL or not
340 valid if lazy is nonzero. */
341 gdb::unique_xmalloc_ptr
<gdb_byte
> contents
;
343 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
344 rather than available, since the common and default case is for a
345 value to be available. This is filled in at value read time.
346 The unavailable ranges are tracked in bits. Note that a contents
347 bit that has been optimized out doesn't really exist in the
348 program, so it can't be marked unavailable either. */
349 std::vector
<range
> unavailable
;
351 /* Likewise, but for optimized out contents (a chunk of the value of
352 a variable that does not actually exist in the program). If LVAL
353 is lval_register, this is a register ($pc, $sp, etc., never a
354 program variable) that has not been saved in the frame. Not
355 saved registers and optimized-out program variables values are
356 treated pretty much the same, except not-saved registers have a
357 different string representation and related error strings. */
358 std::vector
<range
> optimized_out
;
364 get_value_arch (const struct value
*value
)
366 return get_type_arch (value_type (value
));
370 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
372 gdb_assert (!value
->lazy
);
374 return !ranges_contain (value
->unavailable
, offset
, length
);
378 value_bytes_available (const struct value
*value
,
379 LONGEST offset
, LONGEST length
)
381 return value_bits_available (value
,
382 offset
* TARGET_CHAR_BIT
,
383 length
* TARGET_CHAR_BIT
);
387 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
389 gdb_assert (!value
->lazy
);
391 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
395 value_entirely_available (struct value
*value
)
397 /* We can only tell whether the whole value is available when we try
400 value_fetch_lazy (value
);
402 if (value
->unavailable
.empty ())
407 /* Returns true if VALUE is entirely covered by RANGES. If the value
408 is lazy, it'll be read now. Note that RANGE is a pointer to
409 pointer because reading the value might change *RANGE. */
412 value_entirely_covered_by_range_vector (struct value
*value
,
413 const std::vector
<range
> &ranges
)
415 /* We can only tell whether the whole value is optimized out /
416 unavailable when we try to read it. */
418 value_fetch_lazy (value
);
420 if (ranges
.size () == 1)
422 const struct range
&t
= ranges
[0];
425 && t
.length
== (TARGET_CHAR_BIT
426 * TYPE_LENGTH (value_enclosing_type (value
))))
434 value_entirely_unavailable (struct value
*value
)
436 return value_entirely_covered_by_range_vector (value
, value
->unavailable
);
440 value_entirely_optimized_out (struct value
*value
)
442 return value_entirely_covered_by_range_vector (value
, value
->optimized_out
);
445 /* Insert into the vector pointed to by VECTORP the bit range starting of
446 OFFSET bits, and extending for the next LENGTH bits. */
449 insert_into_bit_range_vector (std::vector
<range
> *vectorp
,
450 LONGEST offset
, LONGEST length
)
454 /* Insert the range sorted. If there's overlap or the new range
455 would be contiguous with an existing range, merge. */
457 newr
.offset
= offset
;
458 newr
.length
= length
;
460 /* Do a binary search for the position the given range would be
461 inserted if we only considered the starting OFFSET of ranges.
462 Call that position I. Since we also have LENGTH to care for
463 (this is a range afterall), we need to check if the _previous_
464 range overlaps the I range. E.g., calling R the new range:
466 #1 - overlaps with previous
470 |---| |---| |------| ... |--|
475 In the case #1 above, the binary search would return `I=1',
476 meaning, this OFFSET should be inserted at position 1, and the
477 current position 1 should be pushed further (and become 2). But,
478 note that `0' overlaps with R, so we want to merge them.
480 A similar consideration needs to be taken if the new range would
481 be contiguous with the previous range:
483 #2 - contiguous with previous
487 |--| |---| |------| ... |--|
492 If there's no overlap with the previous range, as in:
494 #3 - not overlapping and not contiguous
498 |--| |---| |------| ... |--|
505 #4 - R is the range with lowest offset
509 |--| |---| |------| ... |--|
514 ... we just push the new range to I.
516 All the 4 cases above need to consider that the new range may
517 also overlap several of the ranges that follow, or that R may be
518 contiguous with the following range, and merge. E.g.,
520 #5 - overlapping following ranges
523 |------------------------|
524 |--| |---| |------| ... |--|
533 |--| |---| |------| ... |--|
540 auto i
= std::lower_bound (vectorp
->begin (), vectorp
->end (), newr
);
541 if (i
> vectorp
->begin ())
543 struct range
&bef
= *(i
- 1);
545 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
548 ULONGEST l
= std::min (bef
.offset
, offset
);
549 ULONGEST h
= std::max (bef
.offset
+ bef
.length
, offset
+ length
);
555 else if (offset
== bef
.offset
+ bef
.length
)
558 bef
.length
+= length
;
564 i
= vectorp
->insert (i
, newr
);
570 i
= vectorp
->insert (i
, newr
);
573 /* Check whether the ranges following the one we've just added or
574 touched can be folded in (#5 above). */
575 if (i
!= vectorp
->end () && i
+ 1 < vectorp
->end ())
580 /* Get the range we just touched. */
581 struct range
&t
= *i
;
585 for (; i
< vectorp
->end (); i
++)
587 struct range
&r
= *i
;
588 if (r
.offset
<= t
.offset
+ t
.length
)
592 l
= std::min (t
.offset
, r
.offset
);
593 h
= std::max (t
.offset
+ t
.length
, r
.offset
+ r
.length
);
602 /* If we couldn't merge this one, we won't be able to
603 merge following ones either, since the ranges are
604 always sorted by OFFSET. */
610 vectorp
->erase (next
, next
+ removed
);
615 mark_value_bits_unavailable (struct value
*value
,
616 LONGEST offset
, LONGEST length
)
618 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
622 mark_value_bytes_unavailable (struct value
*value
,
623 LONGEST offset
, LONGEST length
)
625 mark_value_bits_unavailable (value
,
626 offset
* TARGET_CHAR_BIT
,
627 length
* TARGET_CHAR_BIT
);
630 /* Find the first range in RANGES that overlaps the range defined by
631 OFFSET and LENGTH, starting at element POS in the RANGES vector,
632 Returns the index into RANGES where such overlapping range was
633 found, or -1 if none was found. */
636 find_first_range_overlap (const std::vector
<range
> *ranges
, int pos
,
637 LONGEST offset
, LONGEST length
)
641 for (i
= pos
; i
< ranges
->size (); i
++)
643 const range
&r
= (*ranges
)[i
];
644 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
651 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
652 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
655 It must always be the case that:
656 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
658 It is assumed that memory can be accessed from:
659 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
661 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
662 / TARGET_CHAR_BIT) */
664 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
665 const gdb_byte
*ptr2
, size_t offset2_bits
,
668 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
669 == offset2_bits
% TARGET_CHAR_BIT
);
671 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
674 gdb_byte mask
, b1
, b2
;
676 /* The offset from the base pointers PTR1 and PTR2 is not a complete
677 number of bytes. A number of bits up to either the next exact
678 byte boundary, or LENGTH_BITS (which ever is sooner) will be
680 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
681 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
682 mask
= (1 << bits
) - 1;
684 if (length_bits
< bits
)
686 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
690 /* Now load the two bytes and mask off the bits we care about. */
691 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
692 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
697 /* Now update the length and offsets to take account of the bits
698 we've just compared. */
700 offset1_bits
+= bits
;
701 offset2_bits
+= bits
;
704 if (length_bits
% TARGET_CHAR_BIT
!= 0)
708 gdb_byte mask
, b1
, b2
;
710 /* The length is not an exact number of bytes. After the previous
711 IF.. block then the offsets are byte aligned, or the
712 length is zero (in which case this code is not reached). Compare
713 a number of bits at the end of the region, starting from an exact
715 bits
= length_bits
% TARGET_CHAR_BIT
;
716 o1
= offset1_bits
+ length_bits
- bits
;
717 o2
= offset2_bits
+ length_bits
- bits
;
719 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
720 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
722 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
723 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
725 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
726 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
736 /* We've now taken care of any stray "bits" at the start, or end of
737 the region to compare, the remainder can be covered with a simple
739 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
740 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
741 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
743 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
744 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
745 length_bits
/ TARGET_CHAR_BIT
);
748 /* Length is zero, regions match. */
752 /* Helper struct for find_first_range_overlap_and_match and
753 value_contents_bits_eq. Keep track of which slot of a given ranges
754 vector have we last looked at. */
756 struct ranges_and_idx
759 const std::vector
<range
> *ranges
;
761 /* The range we've last found in RANGES. Given ranges are sorted,
762 we can start the next lookup here. */
766 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
767 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
768 ranges starting at OFFSET2 bits. Return true if the ranges match
769 and fill in *L and *H with the overlapping window relative to
770 (both) OFFSET1 or OFFSET2. */
773 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
774 struct ranges_and_idx
*rp2
,
775 LONGEST offset1
, LONGEST offset2
,
776 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
778 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
780 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
783 if (rp1
->idx
== -1 && rp2
->idx
== -1)
789 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
793 const range
*r1
, *r2
;
797 r1
= &(*rp1
->ranges
)[rp1
->idx
];
798 r2
= &(*rp2
->ranges
)[rp2
->idx
];
800 /* Get the unavailable windows intersected by the incoming
801 ranges. The first and last ranges that overlap the argument
802 range may be wider than said incoming arguments ranges. */
803 l1
= std::max (offset1
, r1
->offset
);
804 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
806 l2
= std::max (offset2
, r2
->offset
);
807 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
809 /* Make them relative to the respective start offsets, so we can
810 compare them for equality. */
817 /* Different ranges, no match. */
818 if (l1
!= l2
|| h1
!= h2
)
827 /* Helper function for value_contents_eq. The only difference is that
828 this function is bit rather than byte based.
830 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
831 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
832 Return true if the available bits match. */
835 value_contents_bits_eq (const struct value
*val1
, int offset1
,
836 const struct value
*val2
, int offset2
,
839 /* Each array element corresponds to a ranges source (unavailable,
840 optimized out). '1' is for VAL1, '2' for VAL2. */
841 struct ranges_and_idx rp1
[2], rp2
[2];
843 /* See function description in value.h. */
844 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
846 /* We shouldn't be trying to compare past the end of the values. */
847 gdb_assert (offset1
+ length
848 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
849 gdb_assert (offset2
+ length
850 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
852 memset (&rp1
, 0, sizeof (rp1
));
853 memset (&rp2
, 0, sizeof (rp2
));
854 rp1
[0].ranges
= &val1
->unavailable
;
855 rp2
[0].ranges
= &val2
->unavailable
;
856 rp1
[1].ranges
= &val1
->optimized_out
;
857 rp2
[1].ranges
= &val2
->optimized_out
;
861 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
864 for (i
= 0; i
< 2; i
++)
866 ULONGEST l_tmp
, h_tmp
;
868 /* The contents only match equal if the invalid/unavailable
869 contents ranges match as well. */
870 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
871 offset1
, offset2
, length
,
875 /* We're interested in the lowest/first range found. */
876 if (i
== 0 || l_tmp
< l
)
883 /* Compare the available/valid contents. */
884 if (memcmp_with_bit_offsets (val1
->contents
.get (), offset1
,
885 val2
->contents
.get (), offset2
, l
) != 0)
897 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
898 const struct value
*val2
, LONGEST offset2
,
901 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
902 val2
, offset2
* TARGET_CHAR_BIT
,
903 length
* TARGET_CHAR_BIT
);
907 /* The value-history records all the values printed by print commands
908 during this session. */
910 static std::vector
<value_ref_ptr
> value_history
;
913 /* List of all value objects currently allocated
914 (except for those released by calls to release_value)
915 This is so they can be freed after each command. */
917 static std::vector
<value_ref_ptr
> all_values
;
919 /* Allocate a lazy value for type TYPE. Its actual content is
920 "lazily" allocated too: the content field of the return value is
921 NULL; it will be allocated when it is fetched from the target. */
924 allocate_value_lazy (struct type
*type
)
928 /* Call check_typedef on our type to make sure that, if TYPE
929 is a TYPE_CODE_TYPEDEF, its length is set to the length
930 of the target type instead of zero. However, we do not
931 replace the typedef type by the target type, because we want
932 to keep the typedef in order to be able to set the VAL's type
933 description correctly. */
934 check_typedef (type
);
936 val
= new struct value (type
);
938 /* Values start out on the all_values chain. */
939 all_values
.emplace_back (val
);
944 /* The maximum size, in bytes, that GDB will try to allocate for a value.
945 The initial value of 64k was not selected for any specific reason, it is
946 just a reasonable starting point. */
948 static int max_value_size
= 65536; /* 64k bytes */
950 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
951 LONGEST, otherwise GDB will not be able to parse integer values from the
952 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
953 be unable to parse "set max-value-size 2".
955 As we want a consistent GDB experience across hosts with different sizes
956 of LONGEST, this arbitrary minimum value was selected, so long as this
957 is bigger than LONGEST on all GDB supported hosts we're fine. */
959 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
960 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
962 /* Implement the "set max-value-size" command. */
965 set_max_value_size (const char *args
, int from_tty
,
966 struct cmd_list_element
*c
)
968 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
970 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
972 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
973 error (_("max-value-size set too low, increasing to %d bytes"),
978 /* Implement the "show max-value-size" command. */
981 show_max_value_size (struct ui_file
*file
, int from_tty
,
982 struct cmd_list_element
*c
, const char *value
)
984 if (max_value_size
== -1)
985 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
987 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
991 /* Called before we attempt to allocate or reallocate a buffer for the
992 contents of a value. TYPE is the type of the value for which we are
993 allocating the buffer. If the buffer is too large (based on the user
994 controllable setting) then throw an error. If this function returns
995 then we should attempt to allocate the buffer. */
998 check_type_length_before_alloc (const struct type
*type
)
1000 unsigned int length
= TYPE_LENGTH (type
);
1002 if (max_value_size
> -1 && length
> max_value_size
)
1004 if (TYPE_NAME (type
) != NULL
)
1005 error (_("value of type `%s' requires %u bytes, which is more "
1006 "than max-value-size"), TYPE_NAME (type
), length
);
1008 error (_("value requires %u bytes, which is more than "
1009 "max-value-size"), length
);
1013 /* Allocate the contents of VAL if it has not been allocated yet. */
1016 allocate_value_contents (struct value
*val
)
1020 check_type_length_before_alloc (val
->enclosing_type
);
1022 ((gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
)));
1026 /* Allocate a value and its contents for type TYPE. */
1029 allocate_value (struct type
*type
)
1031 struct value
*val
= allocate_value_lazy (type
);
1033 allocate_value_contents (val
);
1038 /* Allocate a value that has the correct length
1039 for COUNT repetitions of type TYPE. */
1042 allocate_repeat_value (struct type
*type
, int count
)
1044 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1045 /* FIXME-type-allocation: need a way to free this type when we are
1047 struct type
*array_type
1048 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1050 return allocate_value (array_type
);
1054 allocate_computed_value (struct type
*type
,
1055 const struct lval_funcs
*funcs
,
1058 struct value
*v
= allocate_value_lazy (type
);
1060 VALUE_LVAL (v
) = lval_computed
;
1061 v
->location
.computed
.funcs
= funcs
;
1062 v
->location
.computed
.closure
= closure
;
1067 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1070 allocate_optimized_out_value (struct type
*type
)
1072 struct value
*retval
= allocate_value_lazy (type
);
1074 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1075 set_value_lazy (retval
, 0);
1079 /* Accessor methods. */
1082 value_type (const struct value
*value
)
1087 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1093 value_offset (const struct value
*value
)
1095 return value
->offset
;
1098 set_value_offset (struct value
*value
, LONGEST offset
)
1100 value
->offset
= offset
;
1104 value_bitpos (const struct value
*value
)
1106 return value
->bitpos
;
1109 set_value_bitpos (struct value
*value
, LONGEST bit
)
1111 value
->bitpos
= bit
;
1115 value_bitsize (const struct value
*value
)
1117 return value
->bitsize
;
1120 set_value_bitsize (struct value
*value
, LONGEST bit
)
1122 value
->bitsize
= bit
;
1126 value_parent (const struct value
*value
)
1128 return value
->parent
.get ();
1134 set_value_parent (struct value
*value
, struct value
*parent
)
1136 value
->parent
= value_ref_ptr::new_reference (parent
);
1140 value_contents_raw (struct value
*value
)
1142 struct gdbarch
*arch
= get_value_arch (value
);
1143 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1145 allocate_value_contents (value
);
1146 return value
->contents
.get () + value
->embedded_offset
* unit_size
;
1150 value_contents_all_raw (struct value
*value
)
1152 allocate_value_contents (value
);
1153 return value
->contents
.get ();
1157 value_enclosing_type (const struct value
*value
)
1159 return value
->enclosing_type
;
1162 /* Look at value.h for description. */
1165 value_actual_type (struct value
*value
, int resolve_simple_types
,
1166 int *real_type_found
)
1168 struct value_print_options opts
;
1169 struct type
*result
;
1171 get_user_print_options (&opts
);
1173 if (real_type_found
)
1174 *real_type_found
= 0;
1175 result
= value_type (value
);
1176 if (opts
.objectprint
)
1178 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1179 fetch its rtti type. */
1180 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1181 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1183 && !value_optimized_out (value
))
1185 struct type
*real_type
;
1187 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1190 if (real_type_found
)
1191 *real_type_found
= 1;
1195 else if (resolve_simple_types
)
1197 if (real_type_found
)
1198 *real_type_found
= 1;
1199 result
= value_enclosing_type (value
);
1207 error_value_optimized_out (void)
1209 error (_("value has been optimized out"));
1213 require_not_optimized_out (const struct value
*value
)
1215 if (!value
->optimized_out
.empty ())
1217 if (value
->lval
== lval_register
)
1218 error (_("register has not been saved in frame"));
1220 error_value_optimized_out ();
1225 require_available (const struct value
*value
)
1227 if (!value
->unavailable
.empty ())
1228 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1232 value_contents_for_printing (struct value
*value
)
1235 value_fetch_lazy (value
);
1236 return value
->contents
.get ();
1240 value_contents_for_printing_const (const struct value
*value
)
1242 gdb_assert (!value
->lazy
);
1243 return value
->contents
.get ();
1247 value_contents_all (struct value
*value
)
1249 const gdb_byte
*result
= value_contents_for_printing (value
);
1250 require_not_optimized_out (value
);
1251 require_available (value
);
1255 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1256 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1259 ranges_copy_adjusted (std::vector
<range
> *dst_range
, int dst_bit_offset
,
1260 const std::vector
<range
> &src_range
, int src_bit_offset
,
1263 for (const range
&r
: src_range
)
1267 l
= std::max (r
.offset
, (LONGEST
) src_bit_offset
);
1268 h
= std::min (r
.offset
+ r
.length
,
1269 (LONGEST
) src_bit_offset
+ bit_length
);
1272 insert_into_bit_range_vector (dst_range
,
1273 dst_bit_offset
+ (l
- src_bit_offset
),
1278 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1279 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1282 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1283 const struct value
*src
, int src_bit_offset
,
1286 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1287 src
->unavailable
, src_bit_offset
,
1289 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1290 src
->optimized_out
, src_bit_offset
,
1294 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1295 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1296 contents, starting at DST_OFFSET. If unavailable contents are
1297 being copied from SRC, the corresponding DST contents are marked
1298 unavailable accordingly. Neither DST nor SRC may be lazy
1301 It is assumed the contents of DST in the [DST_OFFSET,
1302 DST_OFFSET+LENGTH) range are wholly available. */
1305 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1306 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1308 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1309 struct gdbarch
*arch
= get_value_arch (src
);
1310 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1312 /* A lazy DST would make that this copy operation useless, since as
1313 soon as DST's contents were un-lazied (by a later value_contents
1314 call, say), the contents would be overwritten. A lazy SRC would
1315 mean we'd be copying garbage. */
1316 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1318 /* The overwritten DST range gets unavailability ORed in, not
1319 replaced. Make sure to remember to implement replacing if it
1320 turns out actually necessary. */
1321 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1322 gdb_assert (!value_bits_any_optimized_out (dst
,
1323 TARGET_CHAR_BIT
* dst_offset
,
1324 TARGET_CHAR_BIT
* length
));
1326 /* Copy the data. */
1327 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1328 value_contents_all_raw (src
) + src_offset
* unit_size
,
1329 length
* unit_size
);
1331 /* Copy the meta-data, adjusted. */
1332 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1333 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1334 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1336 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1337 src
, src_bit_offset
,
1341 /* Copy LENGTH bytes of SRC value's (all) contents
1342 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1343 (all) contents, starting at DST_OFFSET. If unavailable contents
1344 are being copied from SRC, the corresponding DST contents are
1345 marked unavailable accordingly. DST must not be lazy. If SRC is
1346 lazy, it will be fetched now.
1348 It is assumed the contents of DST in the [DST_OFFSET,
1349 DST_OFFSET+LENGTH) range are wholly available. */
1352 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1353 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1356 value_fetch_lazy (src
);
1358 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1362 value_lazy (const struct value
*value
)
1368 set_value_lazy (struct value
*value
, int val
)
1374 value_stack (const struct value
*value
)
1376 return value
->stack
;
1380 set_value_stack (struct value
*value
, int val
)
1386 value_contents (struct value
*value
)
1388 const gdb_byte
*result
= value_contents_writeable (value
);
1389 require_not_optimized_out (value
);
1390 require_available (value
);
1395 value_contents_writeable (struct value
*value
)
1398 value_fetch_lazy (value
);
1399 return value_contents_raw (value
);
1403 value_optimized_out (struct value
*value
)
1405 /* We can only know if a value is optimized out once we have tried to
1407 if (value
->optimized_out
.empty () && value
->lazy
)
1411 value_fetch_lazy (value
);
1413 CATCH (ex
, RETURN_MASK_ERROR
)
1415 /* Fall back to checking value->optimized_out. */
1420 return !value
->optimized_out
.empty ();
1423 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1424 the following LENGTH bytes. */
1427 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1429 mark_value_bits_optimized_out (value
,
1430 offset
* TARGET_CHAR_BIT
,
1431 length
* TARGET_CHAR_BIT
);
1437 mark_value_bits_optimized_out (struct value
*value
,
1438 LONGEST offset
, LONGEST length
)
1440 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1444 value_bits_synthetic_pointer (const struct value
*value
,
1445 LONGEST offset
, LONGEST length
)
1447 if (value
->lval
!= lval_computed
1448 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1450 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1456 value_embedded_offset (const struct value
*value
)
1458 return value
->embedded_offset
;
1462 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1464 value
->embedded_offset
= val
;
1468 value_pointed_to_offset (const struct value
*value
)
1470 return value
->pointed_to_offset
;
1474 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1476 value
->pointed_to_offset
= val
;
1479 const struct lval_funcs
*
1480 value_computed_funcs (const struct value
*v
)
1482 gdb_assert (value_lval_const (v
) == lval_computed
);
1484 return v
->location
.computed
.funcs
;
1488 value_computed_closure (const struct value
*v
)
1490 gdb_assert (v
->lval
== lval_computed
);
1492 return v
->location
.computed
.closure
;
1496 deprecated_value_lval_hack (struct value
*value
)
1498 return &value
->lval
;
1502 value_lval_const (const struct value
*value
)
1508 value_address (const struct value
*value
)
1510 if (value
->lval
!= lval_memory
)
1512 if (value
->parent
!= NULL
)
1513 return value_address (value
->parent
.get ()) + value
->offset
;
1514 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1516 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1517 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1520 return value
->location
.address
+ value
->offset
;
1524 value_raw_address (const struct value
*value
)
1526 if (value
->lval
!= lval_memory
)
1528 return value
->location
.address
;
1532 set_value_address (struct value
*value
, CORE_ADDR addr
)
1534 gdb_assert (value
->lval
== lval_memory
);
1535 value
->location
.address
= addr
;
1538 struct internalvar
**
1539 deprecated_value_internalvar_hack (struct value
*value
)
1541 return &value
->location
.internalvar
;
1545 deprecated_value_next_frame_id_hack (struct value
*value
)
1547 gdb_assert (value
->lval
== lval_register
);
1548 return &value
->location
.reg
.next_frame_id
;
1552 deprecated_value_regnum_hack (struct value
*value
)
1554 gdb_assert (value
->lval
== lval_register
);
1555 return &value
->location
.reg
.regnum
;
1559 deprecated_value_modifiable (const struct value
*value
)
1561 return value
->modifiable
;
1564 /* Return a mark in the value chain. All values allocated after the
1565 mark is obtained (except for those released) are subject to being freed
1566 if a subsequent value_free_to_mark is passed the mark. */
1570 if (all_values
.empty ())
1572 return all_values
.back ().get ();
1578 value_incref (struct value
*val
)
1580 val
->reference_count
++;
1583 /* Release a reference to VAL, which was acquired with value_incref.
1584 This function is also called to deallocate values from the value
1588 value_decref (struct value
*val
)
1592 gdb_assert (val
->reference_count
> 0);
1593 val
->reference_count
--;
1594 if (val
->reference_count
== 0)
1599 /* Free all values allocated since MARK was obtained by value_mark
1600 (except for those released). */
1602 value_free_to_mark (const struct value
*mark
)
1604 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1605 if (iter
== all_values
.end ())
1606 all_values
.clear ();
1608 all_values
.erase (iter
+ 1, all_values
.end ());
1611 /* Remove VAL from the chain all_values
1612 so it will not be freed automatically. */
1615 release_value (struct value
*val
)
1620 return value_ref_ptr ();
1622 std::vector
<value_ref_ptr
>::reverse_iterator iter
;
1623 for (iter
= all_values
.rbegin (); iter
!= all_values
.rend (); ++iter
)
1627 value_ref_ptr result
= *iter
;
1628 all_values
.erase (iter
.base () - 1);
1633 /* We must always return an owned reference. Normally this happens
1634 because we transfer the reference from the value chain, but in
1635 this case the value was not on the chain. */
1636 return value_ref_ptr::new_reference (val
);
1641 std::vector
<value_ref_ptr
>
1642 value_release_to_mark (const struct value
*mark
)
1644 std::vector
<value_ref_ptr
> result
;
1646 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1647 if (iter
== all_values
.end ())
1648 std::swap (result
, all_values
);
1651 std::move (iter
+ 1, all_values
.end (), std::back_inserter (result
));
1652 all_values
.erase (iter
+ 1, all_values
.end ());
1654 std::reverse (result
.begin (), result
.end ());
1658 /* Return a copy of the value ARG.
1659 It contains the same contents, for same memory address,
1660 but it's a different block of storage. */
1663 value_copy (struct value
*arg
)
1665 struct type
*encl_type
= value_enclosing_type (arg
);
1668 if (value_lazy (arg
))
1669 val
= allocate_value_lazy (encl_type
);
1671 val
= allocate_value (encl_type
);
1672 val
->type
= arg
->type
;
1673 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1674 val
->location
= arg
->location
;
1675 val
->offset
= arg
->offset
;
1676 val
->bitpos
= arg
->bitpos
;
1677 val
->bitsize
= arg
->bitsize
;
1678 val
->lazy
= arg
->lazy
;
1679 val
->embedded_offset
= value_embedded_offset (arg
);
1680 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1681 val
->modifiable
= arg
->modifiable
;
1682 if (!value_lazy (val
))
1684 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1685 TYPE_LENGTH (value_enclosing_type (arg
)));
1688 val
->unavailable
= arg
->unavailable
;
1689 val
->optimized_out
= arg
->optimized_out
;
1690 val
->parent
= arg
->parent
;
1691 if (VALUE_LVAL (val
) == lval_computed
)
1693 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1695 if (funcs
->copy_closure
)
1696 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1701 /* Return a "const" and/or "volatile" qualified version of the value V.
1702 If CNST is true, then the returned value will be qualified with
1704 if VOLTL is true, then the returned value will be qualified with
1708 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1710 struct type
*val_type
= value_type (v
);
1711 struct type
*enclosing_type
= value_enclosing_type (v
);
1712 struct value
*cv_val
= value_copy (v
);
1714 deprecated_set_value_type (cv_val
,
1715 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1716 set_value_enclosing_type (cv_val
,
1717 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1722 /* Return a version of ARG that is non-lvalue. */
1725 value_non_lval (struct value
*arg
)
1727 if (VALUE_LVAL (arg
) != not_lval
)
1729 struct type
*enc_type
= value_enclosing_type (arg
);
1730 struct value
*val
= allocate_value (enc_type
);
1732 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1733 TYPE_LENGTH (enc_type
));
1734 val
->type
= arg
->type
;
1735 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1736 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1742 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1745 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1747 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1749 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1750 v
->lval
= lval_memory
;
1751 v
->location
.address
= addr
;
1755 set_value_component_location (struct value
*component
,
1756 const struct value
*whole
)
1760 gdb_assert (whole
->lval
!= lval_xcallable
);
1762 if (whole
->lval
== lval_internalvar
)
1763 VALUE_LVAL (component
) = lval_internalvar_component
;
1765 VALUE_LVAL (component
) = whole
->lval
;
1767 component
->location
= whole
->location
;
1768 if (whole
->lval
== lval_computed
)
1770 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1772 if (funcs
->copy_closure
)
1773 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1776 /* If type has a dynamic resolved location property
1777 update it's value address. */
1778 type
= value_type (whole
);
1779 if (NULL
!= TYPE_DATA_LOCATION (type
)
1780 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1781 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1784 /* Access to the value history. */
1786 /* Record a new value in the value history.
1787 Returns the absolute history index of the entry. */
1790 record_latest_value (struct value
*val
)
1794 /* We don't want this value to have anything to do with the inferior anymore.
1795 In particular, "set $1 = 50" should not affect the variable from which
1796 the value was taken, and fast watchpoints should be able to assume that
1797 a value on the value history never changes. */
1798 if (value_lazy (val
))
1799 value_fetch_lazy (val
);
1800 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1801 from. This is a bit dubious, because then *&$1 does not just return $1
1802 but the current contents of that location. c'est la vie... */
1803 val
->modifiable
= 0;
1805 value_history
.push_back (release_value (val
));
1807 return value_history
.size ();
1810 /* Return a copy of the value in the history with sequence number NUM. */
1813 access_value_history (int num
)
1819 absnum
+= value_history
.size ();
1824 error (_("The history is empty."));
1826 error (_("There is only one value in the history."));
1828 error (_("History does not go back to $$%d."), -num
);
1830 if (absnum
> value_history
.size ())
1831 error (_("History has not yet reached $%d."), absnum
);
1835 return value_copy (value_history
[absnum
].get ());
1839 show_values (const char *num_exp
, int from_tty
)
1847 /* "show values +" should print from the stored position.
1848 "show values <exp>" should print around value number <exp>. */
1849 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1850 num
= parse_and_eval_long (num_exp
) - 5;
1854 /* "show values" means print the last 10 values. */
1855 num
= value_history
.size () - 9;
1861 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1863 struct value_print_options opts
;
1865 val
= access_value_history (i
);
1866 printf_filtered (("$%d = "), i
);
1867 get_user_print_options (&opts
);
1868 value_print (val
, gdb_stdout
, &opts
);
1869 printf_filtered (("\n"));
1872 /* The next "show values +" should start after what we just printed. */
1875 /* Hitting just return after this command should do the same thing as
1876 "show values +". If num_exp is null, this is unnecessary, since
1877 "show values +" is not useful after "show values". */
1878 if (from_tty
&& num_exp
)
1879 set_repeat_arguments ("+");
1882 enum internalvar_kind
1884 /* The internal variable is empty. */
1887 /* The value of the internal variable is provided directly as
1888 a GDB value object. */
1891 /* A fresh value is computed via a call-back routine on every
1892 access to the internal variable. */
1893 INTERNALVAR_MAKE_VALUE
,
1895 /* The internal variable holds a GDB internal convenience function. */
1896 INTERNALVAR_FUNCTION
,
1898 /* The variable holds an integer value. */
1899 INTERNALVAR_INTEGER
,
1901 /* The variable holds a GDB-provided string. */
1905 union internalvar_data
1907 /* A value object used with INTERNALVAR_VALUE. */
1908 struct value
*value
;
1910 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1913 /* The functions to call. */
1914 const struct internalvar_funcs
*functions
;
1916 /* The function's user-data. */
1920 /* The internal function used with INTERNALVAR_FUNCTION. */
1923 struct internal_function
*function
;
1924 /* True if this is the canonical name for the function. */
1928 /* An integer value used with INTERNALVAR_INTEGER. */
1931 /* If type is non-NULL, it will be used as the type to generate
1932 a value for this internal variable. If type is NULL, a default
1933 integer type for the architecture is used. */
1938 /* A string value used with INTERNALVAR_STRING. */
1942 /* Internal variables. These are variables within the debugger
1943 that hold values assigned by debugger commands.
1944 The user refers to them with a '$' prefix
1945 that does not appear in the variable names stored internally. */
1949 struct internalvar
*next
;
1952 /* We support various different kinds of content of an internal variable.
1953 enum internalvar_kind specifies the kind, and union internalvar_data
1954 provides the data associated with this particular kind. */
1956 enum internalvar_kind kind
;
1958 union internalvar_data u
;
1961 static struct internalvar
*internalvars
;
1963 /* If the variable does not already exist create it and give it the
1964 value given. If no value is given then the default is zero. */
1966 init_if_undefined_command (const char* args
, int from_tty
)
1968 struct internalvar
* intvar
;
1970 /* Parse the expression - this is taken from set_command(). */
1971 expression_up expr
= parse_expression (args
);
1973 /* Validate the expression.
1974 Was the expression an assignment?
1975 Or even an expression at all? */
1976 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1977 error (_("Init-if-undefined requires an assignment expression."));
1979 /* Extract the variable from the parsed expression.
1980 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1981 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1982 error (_("The first parameter to init-if-undefined "
1983 "should be a GDB variable."));
1984 intvar
= expr
->elts
[2].internalvar
;
1986 /* Only evaluate the expression if the lvalue is void.
1987 This may still fail if the expresssion is invalid. */
1988 if (intvar
->kind
== INTERNALVAR_VOID
)
1989 evaluate_expression (expr
.get ());
1993 /* Look up an internal variable with name NAME. NAME should not
1994 normally include a dollar sign.
1996 If the specified internal variable does not exist,
1997 the return value is NULL. */
1999 struct internalvar
*
2000 lookup_only_internalvar (const char *name
)
2002 struct internalvar
*var
;
2004 for (var
= internalvars
; var
; var
= var
->next
)
2005 if (strcmp (var
->name
, name
) == 0)
2011 /* Complete NAME by comparing it to the names of internal
2015 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2017 struct internalvar
*var
;
2020 len
= strlen (name
);
2022 for (var
= internalvars
; var
; var
= var
->next
)
2023 if (strncmp (var
->name
, name
, len
) == 0)
2025 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2027 tracker
.add_completion (std::move (copy
));
2031 /* Create an internal variable with name NAME and with a void value.
2032 NAME should not normally include a dollar sign. */
2034 struct internalvar
*
2035 create_internalvar (const char *name
)
2037 struct internalvar
*var
= XNEW (struct internalvar
);
2039 var
->name
= concat (name
, (char *)NULL
);
2040 var
->kind
= INTERNALVAR_VOID
;
2041 var
->next
= internalvars
;
2046 /* Create an internal variable with name NAME and register FUN as the
2047 function that value_of_internalvar uses to create a value whenever
2048 this variable is referenced. NAME should not normally include a
2049 dollar sign. DATA is passed uninterpreted to FUN when it is
2050 called. CLEANUP, if not NULL, is called when the internal variable
2051 is destroyed. It is passed DATA as its only argument. */
2053 struct internalvar
*
2054 create_internalvar_type_lazy (const char *name
,
2055 const struct internalvar_funcs
*funcs
,
2058 struct internalvar
*var
= create_internalvar (name
);
2060 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2061 var
->u
.make_value
.functions
= funcs
;
2062 var
->u
.make_value
.data
= data
;
2066 /* See documentation in value.h. */
2069 compile_internalvar_to_ax (struct internalvar
*var
,
2070 struct agent_expr
*expr
,
2071 struct axs_value
*value
)
2073 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2074 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2077 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2078 var
->u
.make_value
.data
);
2082 /* Look up an internal variable with name NAME. NAME should not
2083 normally include a dollar sign.
2085 If the specified internal variable does not exist,
2086 one is created, with a void value. */
2088 struct internalvar
*
2089 lookup_internalvar (const char *name
)
2091 struct internalvar
*var
;
2093 var
= lookup_only_internalvar (name
);
2097 return create_internalvar (name
);
2100 /* Return current value of internal variable VAR. For variables that
2101 are not inherently typed, use a value type appropriate for GDBARCH. */
2104 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2107 struct trace_state_variable
*tsv
;
2109 /* If there is a trace state variable of the same name, assume that
2110 is what we really want to see. */
2111 tsv
= find_trace_state_variable (var
->name
);
2114 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2116 if (tsv
->value_known
)
2117 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2120 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2126 case INTERNALVAR_VOID
:
2127 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2130 case INTERNALVAR_FUNCTION
:
2131 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2134 case INTERNALVAR_INTEGER
:
2135 if (!var
->u
.integer
.type
)
2136 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2137 var
->u
.integer
.val
);
2139 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2142 case INTERNALVAR_STRING
:
2143 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2144 builtin_type (gdbarch
)->builtin_char
);
2147 case INTERNALVAR_VALUE
:
2148 val
= value_copy (var
->u
.value
);
2149 if (value_lazy (val
))
2150 value_fetch_lazy (val
);
2153 case INTERNALVAR_MAKE_VALUE
:
2154 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2155 var
->u
.make_value
.data
);
2159 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2162 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2163 on this value go back to affect the original internal variable.
2165 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2166 no underlying modifyable state in the internal variable.
2168 Likewise, if the variable's value is a computed lvalue, we want
2169 references to it to produce another computed lvalue, where
2170 references and assignments actually operate through the
2171 computed value's functions.
2173 This means that internal variables with computed values
2174 behave a little differently from other internal variables:
2175 assignments to them don't just replace the previous value
2176 altogether. At the moment, this seems like the behavior we
2179 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2180 && val
->lval
!= lval_computed
)
2182 VALUE_LVAL (val
) = lval_internalvar
;
2183 VALUE_INTERNALVAR (val
) = var
;
2190 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2192 if (var
->kind
== INTERNALVAR_INTEGER
)
2194 *result
= var
->u
.integer
.val
;
2198 if (var
->kind
== INTERNALVAR_VALUE
)
2200 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2202 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2204 *result
= value_as_long (var
->u
.value
);
2213 get_internalvar_function (struct internalvar
*var
,
2214 struct internal_function
**result
)
2218 case INTERNALVAR_FUNCTION
:
2219 *result
= var
->u
.fn
.function
;
2228 set_internalvar_component (struct internalvar
*var
,
2229 LONGEST offset
, LONGEST bitpos
,
2230 LONGEST bitsize
, struct value
*newval
)
2233 struct gdbarch
*arch
;
2238 case INTERNALVAR_VALUE
:
2239 addr
= value_contents_writeable (var
->u
.value
);
2240 arch
= get_value_arch (var
->u
.value
);
2241 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2244 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2245 value_as_long (newval
), bitpos
, bitsize
);
2247 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2248 TYPE_LENGTH (value_type (newval
)));
2252 /* We can never get a component of any other kind. */
2253 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2258 set_internalvar (struct internalvar
*var
, struct value
*val
)
2260 enum internalvar_kind new_kind
;
2261 union internalvar_data new_data
= { 0 };
2263 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2264 error (_("Cannot overwrite convenience function %s"), var
->name
);
2266 /* Prepare new contents. */
2267 switch (TYPE_CODE (check_typedef (value_type (val
))))
2269 case TYPE_CODE_VOID
:
2270 new_kind
= INTERNALVAR_VOID
;
2273 case TYPE_CODE_INTERNAL_FUNCTION
:
2274 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2275 new_kind
= INTERNALVAR_FUNCTION
;
2276 get_internalvar_function (VALUE_INTERNALVAR (val
),
2277 &new_data
.fn
.function
);
2278 /* Copies created here are never canonical. */
2282 new_kind
= INTERNALVAR_VALUE
;
2283 new_data
.value
= value_copy (val
);
2284 new_data
.value
->modifiable
= 1;
2286 /* Force the value to be fetched from the target now, to avoid problems
2287 later when this internalvar is referenced and the target is gone or
2289 if (value_lazy (new_data
.value
))
2290 value_fetch_lazy (new_data
.value
);
2292 /* Release the value from the value chain to prevent it from being
2293 deleted by free_all_values. From here on this function should not
2294 call error () until new_data is installed into the var->u to avoid
2296 release_value (new_data
.value
).release ();
2298 /* Internal variables which are created from values with a dynamic
2299 location don't need the location property of the origin anymore.
2300 The resolved dynamic location is used prior then any other address
2301 when accessing the value.
2302 If we keep it, we would still refer to the origin value.
2303 Remove the location property in case it exist. */
2304 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2309 /* Clean up old contents. */
2310 clear_internalvar (var
);
2313 var
->kind
= new_kind
;
2315 /* End code which must not call error(). */
2319 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2321 /* Clean up old contents. */
2322 clear_internalvar (var
);
2324 var
->kind
= INTERNALVAR_INTEGER
;
2325 var
->u
.integer
.type
= NULL
;
2326 var
->u
.integer
.val
= l
;
2330 set_internalvar_string (struct internalvar
*var
, const char *string
)
2332 /* Clean up old contents. */
2333 clear_internalvar (var
);
2335 var
->kind
= INTERNALVAR_STRING
;
2336 var
->u
.string
= xstrdup (string
);
2340 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2342 /* Clean up old contents. */
2343 clear_internalvar (var
);
2345 var
->kind
= INTERNALVAR_FUNCTION
;
2346 var
->u
.fn
.function
= f
;
2347 var
->u
.fn
.canonical
= 1;
2348 /* Variables installed here are always the canonical version. */
2352 clear_internalvar (struct internalvar
*var
)
2354 /* Clean up old contents. */
2357 case INTERNALVAR_VALUE
:
2358 value_decref (var
->u
.value
);
2361 case INTERNALVAR_STRING
:
2362 xfree (var
->u
.string
);
2365 case INTERNALVAR_MAKE_VALUE
:
2366 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2367 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2374 /* Reset to void kind. */
2375 var
->kind
= INTERNALVAR_VOID
;
2379 internalvar_name (const struct internalvar
*var
)
2384 static struct internal_function
*
2385 create_internal_function (const char *name
,
2386 internal_function_fn handler
, void *cookie
)
2388 struct internal_function
*ifn
= XNEW (struct internal_function
);
2390 ifn
->name
= xstrdup (name
);
2391 ifn
->handler
= handler
;
2392 ifn
->cookie
= cookie
;
2397 value_internal_function_name (struct value
*val
)
2399 struct internal_function
*ifn
;
2402 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2403 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2404 gdb_assert (result
);
2410 call_internal_function (struct gdbarch
*gdbarch
,
2411 const struct language_defn
*language
,
2412 struct value
*func
, int argc
, struct value
**argv
)
2414 struct internal_function
*ifn
;
2417 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2418 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2419 gdb_assert (result
);
2421 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2424 /* The 'function' command. This does nothing -- it is just a
2425 placeholder to let "help function NAME" work. This is also used as
2426 the implementation of the sub-command that is created when
2427 registering an internal function. */
2429 function_command (const char *command
, int from_tty
)
2434 /* Clean up if an internal function's command is destroyed. */
2436 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2438 xfree ((char *) self
->name
);
2439 xfree ((char *) self
->doc
);
2442 /* Add a new internal function. NAME is the name of the function; DOC
2443 is a documentation string describing the function. HANDLER is
2444 called when the function is invoked. COOKIE is an arbitrary
2445 pointer which is passed to HANDLER and is intended for "user
2448 add_internal_function (const char *name
, const char *doc
,
2449 internal_function_fn handler
, void *cookie
)
2451 struct cmd_list_element
*cmd
;
2452 struct internal_function
*ifn
;
2453 struct internalvar
*var
= lookup_internalvar (name
);
2455 ifn
= create_internal_function (name
, handler
, cookie
);
2456 set_internalvar_function (var
, ifn
);
2458 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2460 cmd
->destroyer
= function_destroyer
;
2463 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2464 prevent cycles / duplicates. */
2467 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2468 htab_t copied_types
)
2470 if (TYPE_OBJFILE (value
->type
) == objfile
)
2471 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2473 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2474 value
->enclosing_type
= copy_type_recursive (objfile
,
2475 value
->enclosing_type
,
2479 /* Likewise for internal variable VAR. */
2482 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2483 htab_t copied_types
)
2487 case INTERNALVAR_INTEGER
:
2488 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2490 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2493 case INTERNALVAR_VALUE
:
2494 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2499 /* Update the internal variables and value history when OBJFILE is
2500 discarded; we must copy the types out of the objfile. New global types
2501 will be created for every convenience variable which currently points to
2502 this objfile's types, and the convenience variables will be adjusted to
2503 use the new global types. */
2506 preserve_values (struct objfile
*objfile
)
2508 htab_t copied_types
;
2509 struct internalvar
*var
;
2512 /* Create the hash table. We allocate on the objfile's obstack, since
2513 it is soon to be deleted. */
2514 copied_types
= create_copied_types_hash (objfile
);
2516 for (const value_ref_ptr
&item
: value_history
)
2517 preserve_one_value (item
.get (), objfile
, copied_types
);
2519 for (var
= internalvars
; var
; var
= var
->next
)
2520 preserve_one_internalvar (var
, objfile
, copied_types
);
2522 preserve_ext_lang_values (objfile
, copied_types
);
2524 htab_delete (copied_types
);
2528 show_convenience (const char *ignore
, int from_tty
)
2530 struct gdbarch
*gdbarch
= get_current_arch ();
2531 struct internalvar
*var
;
2533 struct value_print_options opts
;
2535 get_user_print_options (&opts
);
2536 for (var
= internalvars
; var
; var
= var
->next
)
2543 printf_filtered (("$%s = "), var
->name
);
2549 val
= value_of_internalvar (gdbarch
, var
);
2550 value_print (val
, gdb_stdout
, &opts
);
2552 CATCH (ex
, RETURN_MASK_ERROR
)
2554 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2558 printf_filtered (("\n"));
2562 /* This text does not mention convenience functions on purpose.
2563 The user can't create them except via Python, and if Python support
2564 is installed this message will never be printed ($_streq will
2566 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2567 "Convenience variables have "
2568 "names starting with \"$\";\n"
2569 "use \"set\" as in \"set "
2570 "$foo = 5\" to define them.\n"));
2578 value_from_xmethod (xmethod_worker_up
&&worker
)
2582 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2583 v
->lval
= lval_xcallable
;
2584 v
->location
.xm_worker
= worker
.release ();
2590 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2593 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2595 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2596 && method
->lval
== lval_xcallable
&& argc
> 0);
2598 return method
->location
.xm_worker
->get_result_type
2599 (argv
[0], argv
+ 1, argc
- 1);
2602 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2605 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2607 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2608 && method
->lval
== lval_xcallable
&& argc
> 0);
2610 return method
->location
.xm_worker
->invoke (argv
[0], argv
+ 1, argc
- 1);
2613 /* Extract a value as a C number (either long or double).
2614 Knows how to convert fixed values to double, or
2615 floating values to long.
2616 Does not deallocate the value. */
2619 value_as_long (struct value
*val
)
2621 /* This coerces arrays and functions, which is necessary (e.g.
2622 in disassemble_command). It also dereferences references, which
2623 I suspect is the most logical thing to do. */
2624 val
= coerce_array (val
);
2625 return unpack_long (value_type (val
), value_contents (val
));
2628 /* Extract a value as a C pointer. Does not deallocate the value.
2629 Note that val's type may not actually be a pointer; value_as_long
2630 handles all the cases. */
2632 value_as_address (struct value
*val
)
2634 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2636 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2637 whether we want this to be true eventually. */
2639 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2640 non-address (e.g. argument to "signal", "info break", etc.), or
2641 for pointers to char, in which the low bits *are* significant. */
2642 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2645 /* There are several targets (IA-64, PowerPC, and others) which
2646 don't represent pointers to functions as simply the address of
2647 the function's entry point. For example, on the IA-64, a
2648 function pointer points to a two-word descriptor, generated by
2649 the linker, which contains the function's entry point, and the
2650 value the IA-64 "global pointer" register should have --- to
2651 support position-independent code. The linker generates
2652 descriptors only for those functions whose addresses are taken.
2654 On such targets, it's difficult for GDB to convert an arbitrary
2655 function address into a function pointer; it has to either find
2656 an existing descriptor for that function, or call malloc and
2657 build its own. On some targets, it is impossible for GDB to
2658 build a descriptor at all: the descriptor must contain a jump
2659 instruction; data memory cannot be executed; and code memory
2662 Upon entry to this function, if VAL is a value of type `function'
2663 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2664 value_address (val) is the address of the function. This is what
2665 you'll get if you evaluate an expression like `main'. The call
2666 to COERCE_ARRAY below actually does all the usual unary
2667 conversions, which includes converting values of type `function'
2668 to `pointer to function'. This is the challenging conversion
2669 discussed above. Then, `unpack_long' will convert that pointer
2670 back into an address.
2672 So, suppose the user types `disassemble foo' on an architecture
2673 with a strange function pointer representation, on which GDB
2674 cannot build its own descriptors, and suppose further that `foo'
2675 has no linker-built descriptor. The address->pointer conversion
2676 will signal an error and prevent the command from running, even
2677 though the next step would have been to convert the pointer
2678 directly back into the same address.
2680 The following shortcut avoids this whole mess. If VAL is a
2681 function, just return its address directly. */
2682 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2683 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2684 return value_address (val
);
2686 val
= coerce_array (val
);
2688 /* Some architectures (e.g. Harvard), map instruction and data
2689 addresses onto a single large unified address space. For
2690 instance: An architecture may consider a large integer in the
2691 range 0x10000000 .. 0x1000ffff to already represent a data
2692 addresses (hence not need a pointer to address conversion) while
2693 a small integer would still need to be converted integer to
2694 pointer to address. Just assume such architectures handle all
2695 integer conversions in a single function. */
2699 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2700 must admonish GDB hackers to make sure its behavior matches the
2701 compiler's, whenever possible.
2703 In general, I think GDB should evaluate expressions the same way
2704 the compiler does. When the user copies an expression out of
2705 their source code and hands it to a `print' command, they should
2706 get the same value the compiler would have computed. Any
2707 deviation from this rule can cause major confusion and annoyance,
2708 and needs to be justified carefully. In other words, GDB doesn't
2709 really have the freedom to do these conversions in clever and
2712 AndrewC pointed out that users aren't complaining about how GDB
2713 casts integers to pointers; they are complaining that they can't
2714 take an address from a disassembly listing and give it to `x/i'.
2715 This is certainly important.
2717 Adding an architecture method like integer_to_address() certainly
2718 makes it possible for GDB to "get it right" in all circumstances
2719 --- the target has complete control over how things get done, so
2720 people can Do The Right Thing for their target without breaking
2721 anyone else. The standard doesn't specify how integers get
2722 converted to pointers; usually, the ABI doesn't either, but
2723 ABI-specific code is a more reasonable place to handle it. */
2725 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2726 && !TYPE_IS_REFERENCE (value_type (val
))
2727 && gdbarch_integer_to_address_p (gdbarch
))
2728 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2729 value_contents (val
));
2731 return unpack_long (value_type (val
), value_contents (val
));
2735 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2736 as a long, or as a double, assuming the raw data is described
2737 by type TYPE. Knows how to convert different sizes of values
2738 and can convert between fixed and floating point. We don't assume
2739 any alignment for the raw data. Return value is in host byte order.
2741 If you want functions and arrays to be coerced to pointers, and
2742 references to be dereferenced, call value_as_long() instead.
2744 C++: It is assumed that the front-end has taken care of
2745 all matters concerning pointers to members. A pointer
2746 to member which reaches here is considered to be equivalent
2747 to an INT (or some size). After all, it is only an offset. */
2750 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2752 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2753 enum type_code code
= TYPE_CODE (type
);
2754 int len
= TYPE_LENGTH (type
);
2755 int nosign
= TYPE_UNSIGNED (type
);
2759 case TYPE_CODE_TYPEDEF
:
2760 return unpack_long (check_typedef (type
), valaddr
);
2761 case TYPE_CODE_ENUM
:
2762 case TYPE_CODE_FLAGS
:
2763 case TYPE_CODE_BOOL
:
2765 case TYPE_CODE_CHAR
:
2766 case TYPE_CODE_RANGE
:
2767 case TYPE_CODE_MEMBERPTR
:
2769 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2771 return extract_signed_integer (valaddr
, len
, byte_order
);
2774 case TYPE_CODE_DECFLOAT
:
2775 return target_float_to_longest (valaddr
, type
);
2779 case TYPE_CODE_RVALUE_REF
:
2780 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2781 whether we want this to be true eventually. */
2782 return extract_typed_address (valaddr
, type
);
2785 error (_("Value can't be converted to integer."));
2787 return 0; /* Placate lint. */
2790 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2791 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2792 We don't assume any alignment for the raw data. Return value is in
2795 If you want functions and arrays to be coerced to pointers, and
2796 references to be dereferenced, call value_as_address() instead.
2798 C++: It is assumed that the front-end has taken care of
2799 all matters concerning pointers to members. A pointer
2800 to member which reaches here is considered to be equivalent
2801 to an INT (or some size). After all, it is only an offset. */
2804 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2806 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2807 whether we want this to be true eventually. */
2808 return unpack_long (type
, valaddr
);
2812 is_floating_value (struct value
*val
)
2814 struct type
*type
= check_typedef (value_type (val
));
2816 if (is_floating_type (type
))
2818 if (!target_float_is_valid (value_contents (val
), type
))
2819 error (_("Invalid floating value found in program."));
2827 /* Get the value of the FIELDNO'th field (which must be static) of
2831 value_static_field (struct type
*type
, int fieldno
)
2833 struct value
*retval
;
2835 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2837 case FIELD_LOC_KIND_PHYSADDR
:
2838 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2839 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2841 case FIELD_LOC_KIND_PHYSNAME
:
2843 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2844 /* TYPE_FIELD_NAME (type, fieldno); */
2845 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2847 if (sym
.symbol
== NULL
)
2849 /* With some compilers, e.g. HP aCC, static data members are
2850 reported as non-debuggable symbols. */
2851 struct bound_minimal_symbol msym
2852 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2853 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2856 retval
= allocate_optimized_out_value (field_type
);
2858 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2861 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2865 gdb_assert_not_reached ("unexpected field location kind");
2871 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2872 You have to be careful here, since the size of the data area for the value
2873 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2874 than the old enclosing type, you have to allocate more space for the
2878 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2880 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2882 check_type_length_before_alloc (new_encl_type
);
2884 .reset ((gdb_byte
*) xrealloc (val
->contents
.release (),
2885 TYPE_LENGTH (new_encl_type
)));
2888 val
->enclosing_type
= new_encl_type
;
2891 /* Given a value ARG1 (offset by OFFSET bytes)
2892 of a struct or union type ARG_TYPE,
2893 extract and return the value of one of its (non-static) fields.
2894 FIELDNO says which field. */
2897 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2898 int fieldno
, struct type
*arg_type
)
2902 struct gdbarch
*arch
= get_value_arch (arg1
);
2903 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2905 arg_type
= check_typedef (arg_type
);
2906 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2908 /* Call check_typedef on our type to make sure that, if TYPE
2909 is a TYPE_CODE_TYPEDEF, its length is set to the length
2910 of the target type instead of zero. However, we do not
2911 replace the typedef type by the target type, because we want
2912 to keep the typedef in order to be able to print the type
2913 description correctly. */
2914 check_typedef (type
);
2916 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2918 /* Handle packed fields.
2920 Create a new value for the bitfield, with bitpos and bitsize
2921 set. If possible, arrange offset and bitpos so that we can
2922 do a single aligned read of the size of the containing type.
2923 Otherwise, adjust offset to the byte containing the first
2924 bit. Assume that the address, offset, and embedded offset
2925 are sufficiently aligned. */
2927 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2928 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2930 v
= allocate_value_lazy (type
);
2931 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2932 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2933 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2934 v
->bitpos
= bitpos
% container_bitsize
;
2936 v
->bitpos
= bitpos
% 8;
2937 v
->offset
= (value_embedded_offset (arg1
)
2939 + (bitpos
- v
->bitpos
) / 8);
2940 set_value_parent (v
, arg1
);
2941 if (!value_lazy (arg1
))
2942 value_fetch_lazy (v
);
2944 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2946 /* This field is actually a base subobject, so preserve the
2947 entire object's contents for later references to virtual
2951 /* Lazy register values with offsets are not supported. */
2952 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2953 value_fetch_lazy (arg1
);
2955 /* We special case virtual inheritance here because this
2956 requires access to the contents, which we would rather avoid
2957 for references to ordinary fields of unavailable values. */
2958 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2959 boffset
= baseclass_offset (arg_type
, fieldno
,
2960 value_contents (arg1
),
2961 value_embedded_offset (arg1
),
2962 value_address (arg1
),
2965 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2967 if (value_lazy (arg1
))
2968 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2971 v
= allocate_value (value_enclosing_type (arg1
));
2972 value_contents_copy_raw (v
, 0, arg1
, 0,
2973 TYPE_LENGTH (value_enclosing_type (arg1
)));
2976 v
->offset
= value_offset (arg1
);
2977 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2979 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2981 /* Field is a dynamic data member. */
2983 gdb_assert (0 == offset
);
2984 /* We expect an already resolved data location. */
2985 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
2986 /* For dynamic data types defer memory allocation
2987 until we actual access the value. */
2988 v
= allocate_value_lazy (type
);
2992 /* Plain old data member */
2993 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
2994 / (HOST_CHAR_BIT
* unit_size
));
2996 /* Lazy register values with offsets are not supported. */
2997 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2998 value_fetch_lazy (arg1
);
3000 if (value_lazy (arg1
))
3001 v
= allocate_value_lazy (type
);
3004 v
= allocate_value (type
);
3005 value_contents_copy_raw (v
, value_embedded_offset (v
),
3006 arg1
, value_embedded_offset (arg1
) + offset
,
3007 type_length_units (type
));
3009 v
->offset
= (value_offset (arg1
) + offset
3010 + value_embedded_offset (arg1
));
3012 set_value_component_location (v
, arg1
);
3016 /* Given a value ARG1 of a struct or union type,
3017 extract and return the value of one of its (non-static) fields.
3018 FIELDNO says which field. */
3021 value_field (struct value
*arg1
, int fieldno
)
3023 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3026 /* Return a non-virtual function as a value.
3027 F is the list of member functions which contains the desired method.
3028 J is an index into F which provides the desired method.
3030 We only use the symbol for its address, so be happy with either a
3031 full symbol or a minimal symbol. */
3034 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3035 int j
, struct type
*type
,
3039 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3040 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3042 struct bound_minimal_symbol msym
;
3044 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3047 memset (&msym
, 0, sizeof (msym
));
3051 gdb_assert (sym
== NULL
);
3052 msym
= lookup_bound_minimal_symbol (physname
);
3053 if (msym
.minsym
== NULL
)
3057 v
= allocate_value (ftype
);
3058 VALUE_LVAL (v
) = lval_memory
;
3061 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3065 /* The minimal symbol might point to a function descriptor;
3066 resolve it to the actual code address instead. */
3067 struct objfile
*objfile
= msym
.objfile
;
3068 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3070 set_value_address (v
,
3071 gdbarch_convert_from_func_ptr_addr
3072 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), target_stack
));
3077 if (type
!= value_type (*arg1p
))
3078 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3079 value_addr (*arg1p
)));
3081 /* Move the `this' pointer according to the offset.
3082 VALUE_OFFSET (*arg1p) += offset; */
3090 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3091 VALADDR, and store the result in *RESULT.
3092 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3093 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3095 Extracting bits depends on endianness of the machine. Compute the
3096 number of least significant bits to discard. For big endian machines,
3097 we compute the total number of bits in the anonymous object, subtract
3098 off the bit count from the MSB of the object to the MSB of the
3099 bitfield, then the size of the bitfield, which leaves the LSB discard
3100 count. For little endian machines, the discard count is simply the
3101 number of bits from the LSB of the anonymous object to the LSB of the
3104 If the field is signed, we also do sign extension. */
3107 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3108 LONGEST bitpos
, LONGEST bitsize
)
3110 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3115 LONGEST read_offset
;
3117 /* Read the minimum number of bytes required; there may not be
3118 enough bytes to read an entire ULONGEST. */
3119 field_type
= check_typedef (field_type
);
3121 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3124 bytes_read
= TYPE_LENGTH (field_type
);
3125 bitsize
= 8 * bytes_read
;
3128 read_offset
= bitpos
/ 8;
3130 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3131 bytes_read
, byte_order
);
3133 /* Extract bits. See comment above. */
3135 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3136 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3138 lsbcount
= (bitpos
% 8);
3141 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3142 If the field is signed, and is negative, then sign extend. */
3144 if (bitsize
< 8 * (int) sizeof (val
))
3146 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3148 if (!TYPE_UNSIGNED (field_type
))
3150 if (val
& (valmask
^ (valmask
>> 1)))
3160 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3161 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3162 ORIGINAL_VALUE, which must not be NULL. See
3163 unpack_value_bits_as_long for more details. */
3166 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3167 LONGEST embedded_offset
, int fieldno
,
3168 const struct value
*val
, LONGEST
*result
)
3170 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3171 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3172 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3175 gdb_assert (val
!= NULL
);
3177 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3178 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3179 || !value_bits_available (val
, bit_offset
, bitsize
))
3182 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3187 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3188 object at VALADDR. See unpack_bits_as_long for more details. */
3191 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3193 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3194 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3195 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3197 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3200 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3201 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3202 the contents in DEST_VAL, zero or sign extending if the type of
3203 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3204 VAL. If the VAL's contents required to extract the bitfield from
3205 are unavailable/optimized out, DEST_VAL is correspondingly
3206 marked unavailable/optimized out. */
3209 unpack_value_bitfield (struct value
*dest_val
,
3210 LONGEST bitpos
, LONGEST bitsize
,
3211 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3212 const struct value
*val
)
3214 enum bfd_endian byte_order
;
3217 struct type
*field_type
= value_type (dest_val
);
3219 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3221 /* First, unpack and sign extend the bitfield as if it was wholly
3222 valid. Optimized out/unavailable bits are read as zero, but
3223 that's OK, as they'll end up marked below. If the VAL is
3224 wholly-invalid we may have skipped allocating its contents,
3225 though. See allocate_optimized_out_value. */
3226 if (valaddr
!= NULL
)
3230 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3232 store_signed_integer (value_contents_raw (dest_val
),
3233 TYPE_LENGTH (field_type
), byte_order
, num
);
3236 /* Now copy the optimized out / unavailability ranges to the right
3238 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3239 if (byte_order
== BFD_ENDIAN_BIG
)
3240 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3243 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3244 val
, src_bit_offset
, bitsize
);
3247 /* Return a new value with type TYPE, which is FIELDNO field of the
3248 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3249 of VAL. If the VAL's contents required to extract the bitfield
3250 from are unavailable/optimized out, the new value is
3251 correspondingly marked unavailable/optimized out. */
3254 value_field_bitfield (struct type
*type
, int fieldno
,
3255 const gdb_byte
*valaddr
,
3256 LONGEST embedded_offset
, const struct value
*val
)
3258 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3259 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3260 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3262 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3263 valaddr
, embedded_offset
, val
);
3268 /* Modify the value of a bitfield. ADDR points to a block of memory in
3269 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3270 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3271 indicate which bits (in target bit order) comprise the bitfield.
3272 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3273 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3276 modify_field (struct type
*type
, gdb_byte
*addr
,
3277 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3279 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3281 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3284 /* Normalize BITPOS. */
3288 /* If a negative fieldval fits in the field in question, chop
3289 off the sign extension bits. */
3290 if ((~fieldval
& ~(mask
>> 1)) == 0)
3293 /* Warn if value is too big to fit in the field in question. */
3294 if (0 != (fieldval
& ~mask
))
3296 /* FIXME: would like to include fieldval in the message, but
3297 we don't have a sprintf_longest. */
3298 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3300 /* Truncate it, otherwise adjoining fields may be corrupted. */
3304 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3305 false valgrind reports. */
3307 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3308 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3310 /* Shifting for bit field depends on endianness of the target machine. */
3311 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3312 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3314 oword
&= ~(mask
<< bitpos
);
3315 oword
|= fieldval
<< bitpos
;
3317 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3320 /* Pack NUM into BUF using a target format of TYPE. */
3323 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3325 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3328 type
= check_typedef (type
);
3329 len
= TYPE_LENGTH (type
);
3331 switch (TYPE_CODE (type
))
3334 case TYPE_CODE_CHAR
:
3335 case TYPE_CODE_ENUM
:
3336 case TYPE_CODE_FLAGS
:
3337 case TYPE_CODE_BOOL
:
3338 case TYPE_CODE_RANGE
:
3339 case TYPE_CODE_MEMBERPTR
:
3340 store_signed_integer (buf
, len
, byte_order
, num
);
3344 case TYPE_CODE_RVALUE_REF
:
3346 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3350 case TYPE_CODE_DECFLOAT
:
3351 target_float_from_longest (buf
, type
, num
);
3355 error (_("Unexpected type (%d) encountered for integer constant."),
3361 /* Pack NUM into BUF using a target format of TYPE. */
3364 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3367 enum bfd_endian byte_order
;
3369 type
= check_typedef (type
);
3370 len
= TYPE_LENGTH (type
);
3371 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3373 switch (TYPE_CODE (type
))
3376 case TYPE_CODE_CHAR
:
3377 case TYPE_CODE_ENUM
:
3378 case TYPE_CODE_FLAGS
:
3379 case TYPE_CODE_BOOL
:
3380 case TYPE_CODE_RANGE
:
3381 case TYPE_CODE_MEMBERPTR
:
3382 store_unsigned_integer (buf
, len
, byte_order
, num
);
3386 case TYPE_CODE_RVALUE_REF
:
3388 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3392 case TYPE_CODE_DECFLOAT
:
3393 target_float_from_ulongest (buf
, type
, num
);
3397 error (_("Unexpected type (%d) encountered "
3398 "for unsigned integer constant."),
3404 /* Convert C numbers into newly allocated values. */
3407 value_from_longest (struct type
*type
, LONGEST num
)
3409 struct value
*val
= allocate_value (type
);
3411 pack_long (value_contents_raw (val
), type
, num
);
3416 /* Convert C unsigned numbers into newly allocated values. */
3419 value_from_ulongest (struct type
*type
, ULONGEST num
)
3421 struct value
*val
= allocate_value (type
);
3423 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3429 /* Create a value representing a pointer of type TYPE to the address
3433 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3435 struct value
*val
= allocate_value (type
);
3437 store_typed_address (value_contents_raw (val
),
3438 check_typedef (type
), addr
);
3443 /* Create a value of type TYPE whose contents come from VALADDR, if it
3444 is non-null, and whose memory address (in the inferior) is
3445 ADDRESS. The type of the created value may differ from the passed
3446 type TYPE. Make sure to retrieve values new type after this call.
3447 Note that TYPE is not passed through resolve_dynamic_type; this is
3448 a special API intended for use only by Ada. */
3451 value_from_contents_and_address_unresolved (struct type
*type
,
3452 const gdb_byte
*valaddr
,
3457 if (valaddr
== NULL
)
3458 v
= allocate_value_lazy (type
);
3460 v
= value_from_contents (type
, valaddr
);
3461 VALUE_LVAL (v
) = lval_memory
;
3462 set_value_address (v
, address
);
3466 /* Create a value of type TYPE whose contents come from VALADDR, if it
3467 is non-null, and whose memory address (in the inferior) is
3468 ADDRESS. The type of the created value may differ from the passed
3469 type TYPE. Make sure to retrieve values new type after this call. */
3472 value_from_contents_and_address (struct type
*type
,
3473 const gdb_byte
*valaddr
,
3476 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3477 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3480 if (valaddr
== NULL
)
3481 v
= allocate_value_lazy (resolved_type
);
3483 v
= value_from_contents (resolved_type
, valaddr
);
3484 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3485 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3486 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3487 VALUE_LVAL (v
) = lval_memory
;
3488 set_value_address (v
, address
);
3492 /* Create a value of type TYPE holding the contents CONTENTS.
3493 The new value is `not_lval'. */
3496 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3498 struct value
*result
;
3500 result
= allocate_value (type
);
3501 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3505 /* Extract a value from the history file. Input will be of the form
3506 $digits or $$digits. See block comment above 'write_dollar_variable'
3510 value_from_history_ref (const char *h
, const char **endp
)
3522 /* Find length of numeral string. */
3523 for (; isdigit (h
[len
]); len
++)
3526 /* Make sure numeral string is not part of an identifier. */
3527 if (h
[len
] == '_' || isalpha (h
[len
]))
3530 /* Now collect the index value. */
3535 /* For some bizarre reason, "$$" is equivalent to "$$1",
3536 rather than to "$$0" as it ought to be! */
3544 index
= -strtol (&h
[2], &local_end
, 10);
3552 /* "$" is equivalent to "$0". */
3560 index
= strtol (&h
[1], &local_end
, 10);
3565 return access_value_history (index
);
3568 /* Get the component value (offset by OFFSET bytes) of a struct or
3569 union WHOLE. Component's type is TYPE. */
3572 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3576 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3577 v
= allocate_value_lazy (type
);
3580 v
= allocate_value (type
);
3581 value_contents_copy (v
, value_embedded_offset (v
),
3582 whole
, value_embedded_offset (whole
) + offset
,
3583 type_length_units (type
));
3585 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3586 set_value_component_location (v
, whole
);
3592 coerce_ref_if_computed (const struct value
*arg
)
3594 const struct lval_funcs
*funcs
;
3596 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3599 if (value_lval_const (arg
) != lval_computed
)
3602 funcs
= value_computed_funcs (arg
);
3603 if (funcs
->coerce_ref
== NULL
)
3606 return funcs
->coerce_ref (arg
);
3609 /* Look at value.h for description. */
3612 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3613 const struct type
*original_type
,
3614 const struct value
*original_value
)
3616 /* Re-adjust type. */
3617 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3619 /* Add embedding info. */
3620 set_value_enclosing_type (value
, enc_type
);
3621 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3623 /* We may be pointing to an object of some derived type. */
3624 return value_full_object (value
, NULL
, 0, 0, 0);
3628 coerce_ref (struct value
*arg
)
3630 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3631 struct value
*retval
;
3632 struct type
*enc_type
;
3634 retval
= coerce_ref_if_computed (arg
);
3638 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3641 enc_type
= check_typedef (value_enclosing_type (arg
));
3642 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3644 retval
= value_at_lazy (enc_type
,
3645 unpack_pointer (value_type (arg
),
3646 value_contents (arg
)));
3647 enc_type
= value_type (retval
);
3648 return readjust_indirect_value_type (retval
, enc_type
,
3649 value_type_arg_tmp
, arg
);
3653 coerce_array (struct value
*arg
)
3657 arg
= coerce_ref (arg
);
3658 type
= check_typedef (value_type (arg
));
3660 switch (TYPE_CODE (type
))
3662 case TYPE_CODE_ARRAY
:
3663 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3664 arg
= value_coerce_array (arg
);
3666 case TYPE_CODE_FUNC
:
3667 arg
= value_coerce_function (arg
);
3674 /* Return the return value convention that will be used for the
3677 enum return_value_convention
3678 struct_return_convention (struct gdbarch
*gdbarch
,
3679 struct value
*function
, struct type
*value_type
)
3681 enum type_code code
= TYPE_CODE (value_type
);
3683 if (code
== TYPE_CODE_ERROR
)
3684 error (_("Function return type unknown."));
3686 /* Probe the architecture for the return-value convention. */
3687 return gdbarch_return_value (gdbarch
, function
, value_type
,
3691 /* Return true if the function returning the specified type is using
3692 the convention of returning structures in memory (passing in the
3693 address as a hidden first parameter). */
3696 using_struct_return (struct gdbarch
*gdbarch
,
3697 struct value
*function
, struct type
*value_type
)
3699 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3700 /* A void return value is never in memory. See also corresponding
3701 code in "print_return_value". */
3704 return (struct_return_convention (gdbarch
, function
, value_type
)
3705 != RETURN_VALUE_REGISTER_CONVENTION
);
3708 /* Set the initialized field in a value struct. */
3711 set_value_initialized (struct value
*val
, int status
)
3713 val
->initialized
= status
;
3716 /* Return the initialized field in a value struct. */
3719 value_initialized (const struct value
*val
)
3721 return val
->initialized
;
3724 /* Load the actual content of a lazy value. Fetch the data from the
3725 user's process and clear the lazy flag to indicate that the data in
3726 the buffer is valid.
3728 If the value is zero-length, we avoid calling read_memory, which
3729 would abort. We mark the value as fetched anyway -- all 0 bytes of
3733 value_fetch_lazy (struct value
*val
)
3735 gdb_assert (value_lazy (val
));
3736 allocate_value_contents (val
);
3737 /* A value is either lazy, or fully fetched. The
3738 availability/validity is only established as we try to fetch a
3740 gdb_assert (val
->optimized_out
.empty ());
3741 gdb_assert (val
->unavailable
.empty ());
3742 if (value_bitsize (val
))
3744 /* To read a lazy bitfield, read the entire enclosing value. This
3745 prevents reading the same block of (possibly volatile) memory once
3746 per bitfield. It would be even better to read only the containing
3747 word, but we have no way to record that just specific bits of a
3748 value have been fetched. */
3749 struct type
*type
= check_typedef (value_type (val
));
3750 struct value
*parent
= value_parent (val
);
3752 if (value_lazy (parent
))
3753 value_fetch_lazy (parent
);
3755 unpack_value_bitfield (val
,
3756 value_bitpos (val
), value_bitsize (val
),
3757 value_contents_for_printing (parent
),
3758 value_offset (val
), parent
);
3760 else if (VALUE_LVAL (val
) == lval_memory
)
3762 CORE_ADDR addr
= value_address (val
);
3763 struct type
*type
= check_typedef (value_enclosing_type (val
));
3765 if (TYPE_LENGTH (type
))
3766 read_value_memory (val
, 0, value_stack (val
),
3767 addr
, value_contents_all_raw (val
),
3768 type_length_units (type
));
3770 else if (VALUE_LVAL (val
) == lval_register
)
3772 struct frame_info
*next_frame
;
3774 struct type
*type
= check_typedef (value_type (val
));
3775 struct value
*new_val
= val
, *mark
= value_mark ();
3777 /* Offsets are not supported here; lazy register values must
3778 refer to the entire register. */
3779 gdb_assert (value_offset (val
) == 0);
3781 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3783 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3785 next_frame
= frame_find_by_id (next_frame_id
);
3786 regnum
= VALUE_REGNUM (new_val
);
3788 gdb_assert (next_frame
!= NULL
);
3790 /* Convertible register routines are used for multi-register
3791 values and for interpretation in different types
3792 (e.g. float or int from a double register). Lazy
3793 register values should have the register's natural type,
3794 so they do not apply. */
3795 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3798 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3799 Since a "->next" operation was performed when setting
3800 this field, we do not need to perform a "next" operation
3801 again when unwinding the register. That's why
3802 frame_unwind_register_value() is called here instead of
3803 get_frame_register_value(). */
3804 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3806 /* If we get another lazy lval_register value, it means the
3807 register is found by reading it from NEXT_FRAME's next frame.
3808 frame_unwind_register_value should never return a value with
3809 the frame id pointing to NEXT_FRAME. If it does, it means we
3810 either have two consecutive frames with the same frame id
3811 in the frame chain, or some code is trying to unwind
3812 behind get_prev_frame's back (e.g., a frame unwind
3813 sniffer trying to unwind), bypassing its validations. In
3814 any case, it should always be an internal error to end up
3815 in this situation. */
3816 if (VALUE_LVAL (new_val
) == lval_register
3817 && value_lazy (new_val
)
3818 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3819 internal_error (__FILE__
, __LINE__
,
3820 _("infinite loop while fetching a register"));
3823 /* If it's still lazy (for instance, a saved register on the
3824 stack), fetch it. */
3825 if (value_lazy (new_val
))
3826 value_fetch_lazy (new_val
);
3828 /* Copy the contents and the unavailability/optimized-out
3829 meta-data from NEW_VAL to VAL. */
3830 set_value_lazy (val
, 0);
3831 value_contents_copy (val
, value_embedded_offset (val
),
3832 new_val
, value_embedded_offset (new_val
),
3833 type_length_units (type
));
3837 struct gdbarch
*gdbarch
;
3838 struct frame_info
*frame
;
3839 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3840 so that the frame level will be shown correctly. */
3841 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3842 regnum
= VALUE_REGNUM (val
);
3843 gdbarch
= get_frame_arch (frame
);
3845 fprintf_unfiltered (gdb_stdlog
,
3846 "{ value_fetch_lazy "
3847 "(frame=%d,regnum=%d(%s),...) ",
3848 frame_relative_level (frame
), regnum
,
3849 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3851 fprintf_unfiltered (gdb_stdlog
, "->");
3852 if (value_optimized_out (new_val
))
3854 fprintf_unfiltered (gdb_stdlog
, " ");
3855 val_print_optimized_out (new_val
, gdb_stdlog
);
3860 const gdb_byte
*buf
= value_contents (new_val
);
3862 if (VALUE_LVAL (new_val
) == lval_register
)
3863 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3864 VALUE_REGNUM (new_val
));
3865 else if (VALUE_LVAL (new_val
) == lval_memory
)
3866 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3868 value_address (new_val
)));
3870 fprintf_unfiltered (gdb_stdlog
, " computed");
3872 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3873 fprintf_unfiltered (gdb_stdlog
, "[");
3874 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3875 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3876 fprintf_unfiltered (gdb_stdlog
, "]");
3879 fprintf_unfiltered (gdb_stdlog
, " }\n");
3882 /* Dispose of the intermediate values. This prevents
3883 watchpoints from trying to watch the saved frame pointer. */
3884 value_free_to_mark (mark
);
3886 else if (VALUE_LVAL (val
) == lval_computed
3887 && value_computed_funcs (val
)->read
!= NULL
)
3888 value_computed_funcs (val
)->read (val
);
3890 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3892 set_value_lazy (val
, 0);
3895 /* Implementation of the convenience function $_isvoid. */
3897 static struct value
*
3898 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3899 const struct language_defn
*language
,
3900 void *cookie
, int argc
, struct value
**argv
)
3905 error (_("You must provide one argument for $_isvoid."));
3907 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3909 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3916 /* Test the ranges_contain function. */
3919 test_ranges_contain ()
3921 std::vector
<range
> ranges
;
3927 ranges
.push_back (r
);
3932 ranges
.push_back (r
);
3935 SELF_CHECK (!ranges_contain (ranges
, 2, 5));
3937 SELF_CHECK (ranges_contain (ranges
, 9, 5));
3939 SELF_CHECK (ranges_contain (ranges
, 10, 2));
3941 SELF_CHECK (ranges_contain (ranges
, 10, 5));
3943 SELF_CHECK (ranges_contain (ranges
, 13, 6));
3945 SELF_CHECK (ranges_contain (ranges
, 14, 5));
3947 SELF_CHECK (!ranges_contain (ranges
, 15, 4));
3949 SELF_CHECK (!ranges_contain (ranges
, 16, 4));
3951 SELF_CHECK (ranges_contain (ranges
, 16, 6));
3953 SELF_CHECK (ranges_contain (ranges
, 21, 1));
3955 SELF_CHECK (ranges_contain (ranges
, 21, 5));
3957 SELF_CHECK (!ranges_contain (ranges
, 26, 3));
3960 /* Check that RANGES contains the same ranges as EXPECTED. */
3963 check_ranges_vector (gdb::array_view
<const range
> ranges
,
3964 gdb::array_view
<const range
> expected
)
3966 return ranges
== expected
;
3969 /* Test the insert_into_bit_range_vector function. */
3972 test_insert_into_bit_range_vector ()
3974 std::vector
<range
> ranges
;
3978 insert_into_bit_range_vector (&ranges
, 10, 5);
3979 static const range expected
[] = {
3982 SELF_CHECK (check_ranges_vector (ranges
, expected
));
3987 insert_into_bit_range_vector (&ranges
, 11, 4);
3988 static const range expected
= {10, 5};
3989 SELF_CHECK (check_ranges_vector (ranges
, expected
));
3992 /* [10, 14] [20, 24] */
3994 insert_into_bit_range_vector (&ranges
, 20, 5);
3995 static const range expected
[] = {
3999 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4002 /* [10, 14] [17, 24] */
4004 insert_into_bit_range_vector (&ranges
, 17, 5);
4005 static const range expected
[] = {
4009 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4012 /* [2, 8] [10, 14] [17, 24] */
4014 insert_into_bit_range_vector (&ranges
, 2, 7);
4015 static const range expected
[] = {
4020 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4023 /* [2, 14] [17, 24] */
4025 insert_into_bit_range_vector (&ranges
, 9, 1);
4026 static const range expected
[] = {
4030 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4033 /* [2, 14] [17, 24] */
4035 insert_into_bit_range_vector (&ranges
, 9, 1);
4036 static const range expected
[] = {
4040 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4045 insert_into_bit_range_vector (&ranges
, 4, 30);
4046 static const range expected
= {2, 32};
4047 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4051 } /* namespace selftests */
4052 #endif /* GDB_SELF_TEST */
4055 _initialize_values (void)
4057 add_cmd ("convenience", no_class
, show_convenience
, _("\
4058 Debugger convenience (\"$foo\") variables and functions.\n\
4059 Convenience variables are created when you assign them values;\n\
4060 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4062 A few convenience variables are given values automatically:\n\
4063 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4064 \"$__\" holds the contents of the last address examined with \"x\"."
4067 Convenience functions are defined via the Python API."
4070 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4072 add_cmd ("values", no_set_class
, show_values
, _("\
4073 Elements of value history around item number IDX (or last ten)."),
4076 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4077 Initialize a convenience variable if necessary.\n\
4078 init-if-undefined VARIABLE = EXPRESSION\n\
4079 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4080 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4081 VARIABLE is already initialized."));
4083 add_prefix_cmd ("function", no_class
, function_command
, _("\
4084 Placeholder command for showing help on convenience functions."),
4085 &functionlist
, "function ", 0, &cmdlist
);
4087 add_internal_function ("_isvoid", _("\
4088 Check whether an expression is void.\n\
4089 Usage: $_isvoid (expression)\n\
4090 Return 1 if the expression is void, zero otherwise."),
4091 isvoid_internal_fn
, NULL
);
4093 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4094 class_support
, &max_value_size
, _("\
4095 Set maximum sized value gdb will load from the inferior."), _("\
4096 Show maximum sized value gdb will load from the inferior."), _("\
4097 Use this to control the maximum size, in bytes, of a value that gdb\n\
4098 will load from the inferior. Setting this value to 'unlimited'\n\
4099 disables checking.\n\
4100 Setting this does not invalidate already allocated values, it only\n\
4101 prevents future values, larger than this size, from being allocated."),
4103 show_max_value_size
,
4104 &setlist
, &showlist
);
4106 selftests::register_test ("ranges_contain", selftests::test_ranges_contain
);
4107 selftests::register_test ("insert_into_bit_range_vector",
4108 selftests::test_insert_into_bit_range_vector
);