1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2020 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"
44 #include "gdbsupport/selftest.h"
45 #include "gdbsupport/array-view.h"
46 #include "cli/cli-style.h"
48 /* Definition of a user function. */
49 struct internal_function
51 /* The name of the function. It is a bit odd to have this in the
52 function itself -- the user might use a differently-named
53 convenience variable to hold the function. */
57 internal_function_fn handler
;
59 /* User data for the handler. */
63 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
67 /* Lowest offset in the range. */
70 /* Length of the range. */
73 /* Returns true if THIS is strictly less than OTHER, useful for
74 searching. We keep ranges sorted by offset and coalesce
75 overlapping and contiguous ranges, so this just compares the
78 bool operator< (const range
&other
) const
80 return offset
< other
.offset
;
83 /* Returns true if THIS is equal to OTHER. */
84 bool operator== (const range
&other
) const
86 return offset
== other
.offset
&& length
== other
.length
;
90 /* Returns true if the ranges defined by [offset1, offset1+len1) and
91 [offset2, offset2+len2) overlap. */
94 ranges_overlap (LONGEST offset1
, LONGEST len1
,
95 LONGEST offset2
, LONGEST len2
)
99 l
= std::max (offset1
, offset2
);
100 h
= std::min (offset1
+ len1
, offset2
+ len2
);
104 /* Returns true if RANGES contains any range that overlaps [OFFSET,
108 ranges_contain (const std::vector
<range
> &ranges
, LONGEST offset
,
113 what
.offset
= offset
;
114 what
.length
= length
;
116 /* We keep ranges sorted by offset and coalesce overlapping and
117 contiguous ranges, so to check if a range list contains a given
118 range, we can do a binary search for the position the given range
119 would be inserted if we only considered the starting OFFSET of
120 ranges. We call that position I. Since we also have LENGTH to
121 care for (this is a range afterall), we need to check if the
122 _previous_ range overlaps the I range. E.g.,
126 |---| |---| |------| ... |--|
131 In the case above, the binary search would return `I=1', meaning,
132 this OFFSET should be inserted at position 1, and the current
133 position 1 should be pushed further (and before 2). But, `0'
136 Then we need to check if the I range overlaps the I range itself.
141 |---| |---| |-------| ... |--|
148 auto i
= std::lower_bound (ranges
.begin (), ranges
.end (), what
);
150 if (i
> ranges
.begin ())
152 const struct range
&bef
= *(i
- 1);
154 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
158 if (i
< ranges
.end ())
160 const struct range
&r
= *i
;
162 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
169 static struct cmd_list_element
*functionlist
;
171 /* Note that the fields in this structure are arranged to save a bit
176 explicit value (struct type
*type_
)
182 enclosing_type (type_
)
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 little-endian targets, it is the position of the LSB. For
277 big-endian 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 ULONGEST length
= TYPE_LENGTH (type
);
1002 if (max_value_size
> -1 && length
> max_value_size
)
1004 if (type
->name () != NULL
)
1005 error (_("value of type `%s' requires %s bytes, which is more "
1006 "than max-value-size"), type
->name (), pulongest (length
));
1008 error (_("value requires %s bytes, which is more than "
1009 "max-value-size"), pulongest (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 /* Despite the fact that we are really creating an array of TYPE here, we
1045 use the string lower bound as the array lower bound. This seems to
1046 work fine for now. */
1047 int low_bound
= current_language
->string_lower_bound ();
1048 /* FIXME-type-allocation: need a way to free this type when we are
1050 struct type
*array_type
1051 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1053 return allocate_value (array_type
);
1057 allocate_computed_value (struct type
*type
,
1058 const struct lval_funcs
*funcs
,
1061 struct value
*v
= allocate_value_lazy (type
);
1063 VALUE_LVAL (v
) = lval_computed
;
1064 v
->location
.computed
.funcs
= funcs
;
1065 v
->location
.computed
.closure
= closure
;
1070 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1073 allocate_optimized_out_value (struct type
*type
)
1075 struct value
*retval
= allocate_value_lazy (type
);
1077 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1078 set_value_lazy (retval
, 0);
1082 /* Accessor methods. */
1085 value_type (const struct value
*value
)
1090 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1096 value_offset (const struct value
*value
)
1098 return value
->offset
;
1101 set_value_offset (struct value
*value
, LONGEST offset
)
1103 value
->offset
= offset
;
1107 value_bitpos (const struct value
*value
)
1109 return value
->bitpos
;
1112 set_value_bitpos (struct value
*value
, LONGEST bit
)
1114 value
->bitpos
= bit
;
1118 value_bitsize (const struct value
*value
)
1120 return value
->bitsize
;
1123 set_value_bitsize (struct value
*value
, LONGEST bit
)
1125 value
->bitsize
= bit
;
1129 value_parent (const struct value
*value
)
1131 return value
->parent
.get ();
1137 set_value_parent (struct value
*value
, struct value
*parent
)
1139 value
->parent
= value_ref_ptr::new_reference (parent
);
1143 value_contents_raw (struct value
*value
)
1145 struct gdbarch
*arch
= get_value_arch (value
);
1146 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1148 allocate_value_contents (value
);
1149 return value
->contents
.get () + value
->embedded_offset
* unit_size
;
1153 value_contents_all_raw (struct value
*value
)
1155 allocate_value_contents (value
);
1156 return value
->contents
.get ();
1160 value_enclosing_type (const struct value
*value
)
1162 return value
->enclosing_type
;
1165 /* Look at value.h for description. */
1168 value_actual_type (struct value
*value
, int resolve_simple_types
,
1169 int *real_type_found
)
1171 struct value_print_options opts
;
1172 struct type
*result
;
1174 get_user_print_options (&opts
);
1176 if (real_type_found
)
1177 *real_type_found
= 0;
1178 result
= value_type (value
);
1179 if (opts
.objectprint
)
1181 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1182 fetch its rtti type. */
1183 if ((result
->code () == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1184 && (check_typedef (TYPE_TARGET_TYPE (result
))->code ()
1185 == TYPE_CODE_STRUCT
)
1186 && !value_optimized_out (value
))
1188 struct type
*real_type
;
1190 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1193 if (real_type_found
)
1194 *real_type_found
= 1;
1198 else if (resolve_simple_types
)
1200 if (real_type_found
)
1201 *real_type_found
= 1;
1202 result
= value_enclosing_type (value
);
1210 error_value_optimized_out (void)
1212 error (_("value has been optimized out"));
1216 require_not_optimized_out (const struct value
*value
)
1218 if (!value
->optimized_out
.empty ())
1220 if (value
->lval
== lval_register
)
1221 error (_("register has not been saved in frame"));
1223 error_value_optimized_out ();
1228 require_available (const struct value
*value
)
1230 if (!value
->unavailable
.empty ())
1231 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1235 value_contents_for_printing (struct value
*value
)
1238 value_fetch_lazy (value
);
1239 return value
->contents
.get ();
1243 value_contents_for_printing_const (const struct value
*value
)
1245 gdb_assert (!value
->lazy
);
1246 return value
->contents
.get ();
1250 value_contents_all (struct value
*value
)
1252 const gdb_byte
*result
= value_contents_for_printing (value
);
1253 require_not_optimized_out (value
);
1254 require_available (value
);
1258 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1259 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1262 ranges_copy_adjusted (std::vector
<range
> *dst_range
, int dst_bit_offset
,
1263 const std::vector
<range
> &src_range
, int src_bit_offset
,
1266 for (const range
&r
: src_range
)
1270 l
= std::max (r
.offset
, (LONGEST
) src_bit_offset
);
1271 h
= std::min (r
.offset
+ r
.length
,
1272 (LONGEST
) src_bit_offset
+ bit_length
);
1275 insert_into_bit_range_vector (dst_range
,
1276 dst_bit_offset
+ (l
- src_bit_offset
),
1281 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1282 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1285 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1286 const struct value
*src
, int src_bit_offset
,
1289 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1290 src
->unavailable
, src_bit_offset
,
1292 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1293 src
->optimized_out
, src_bit_offset
,
1297 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1298 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1299 contents, starting at DST_OFFSET. If unavailable contents are
1300 being copied from SRC, the corresponding DST contents are marked
1301 unavailable accordingly. Neither DST nor SRC may be lazy
1304 It is assumed the contents of DST in the [DST_OFFSET,
1305 DST_OFFSET+LENGTH) range are wholly available. */
1308 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1309 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1311 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1312 struct gdbarch
*arch
= get_value_arch (src
);
1313 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1315 /* A lazy DST would make that this copy operation useless, since as
1316 soon as DST's contents were un-lazied (by a later value_contents
1317 call, say), the contents would be overwritten. A lazy SRC would
1318 mean we'd be copying garbage. */
1319 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1321 /* The overwritten DST range gets unavailability ORed in, not
1322 replaced. Make sure to remember to implement replacing if it
1323 turns out actually necessary. */
1324 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1325 gdb_assert (!value_bits_any_optimized_out (dst
,
1326 TARGET_CHAR_BIT
* dst_offset
,
1327 TARGET_CHAR_BIT
* length
));
1329 /* Copy the data. */
1330 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1331 value_contents_all_raw (src
) + src_offset
* unit_size
,
1332 length
* unit_size
);
1334 /* Copy the meta-data, adjusted. */
1335 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1336 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1337 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1339 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1340 src
, src_bit_offset
,
1344 /* Copy LENGTH bytes of SRC value's (all) contents
1345 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1346 (all) contents, starting at DST_OFFSET. If unavailable contents
1347 are being copied from SRC, the corresponding DST contents are
1348 marked unavailable accordingly. DST must not be lazy. If SRC is
1349 lazy, it will be fetched now.
1351 It is assumed the contents of DST in the [DST_OFFSET,
1352 DST_OFFSET+LENGTH) range are wholly available. */
1355 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1356 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1359 value_fetch_lazy (src
);
1361 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1365 value_lazy (const struct value
*value
)
1371 set_value_lazy (struct value
*value
, int val
)
1377 value_stack (const struct value
*value
)
1379 return value
->stack
;
1383 set_value_stack (struct value
*value
, int val
)
1389 value_contents (struct value
*value
)
1391 const gdb_byte
*result
= value_contents_writeable (value
);
1392 require_not_optimized_out (value
);
1393 require_available (value
);
1398 value_contents_writeable (struct value
*value
)
1401 value_fetch_lazy (value
);
1402 return value_contents_raw (value
);
1406 value_optimized_out (struct value
*value
)
1408 /* We can only know if a value is optimized out once we have tried to
1410 if (value
->optimized_out
.empty () && value
->lazy
)
1414 value_fetch_lazy (value
);
1416 catch (const gdb_exception_error
&ex
)
1421 case OPTIMIZED_OUT_ERROR
:
1422 case NOT_AVAILABLE_ERROR
:
1423 /* These can normally happen when we try to access an
1424 optimized out or unavailable register, either in a
1425 physical register or spilled to memory. */
1433 return !value
->optimized_out
.empty ();
1436 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1437 the following LENGTH bytes. */
1440 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1442 mark_value_bits_optimized_out (value
,
1443 offset
* TARGET_CHAR_BIT
,
1444 length
* TARGET_CHAR_BIT
);
1450 mark_value_bits_optimized_out (struct value
*value
,
1451 LONGEST offset
, LONGEST length
)
1453 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1457 value_bits_synthetic_pointer (const struct value
*value
,
1458 LONGEST offset
, LONGEST length
)
1460 if (value
->lval
!= lval_computed
1461 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1463 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1469 value_embedded_offset (const struct value
*value
)
1471 return value
->embedded_offset
;
1475 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1477 value
->embedded_offset
= val
;
1481 value_pointed_to_offset (const struct value
*value
)
1483 return value
->pointed_to_offset
;
1487 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1489 value
->pointed_to_offset
= val
;
1492 const struct lval_funcs
*
1493 value_computed_funcs (const struct value
*v
)
1495 gdb_assert (value_lval_const (v
) == lval_computed
);
1497 return v
->location
.computed
.funcs
;
1501 value_computed_closure (const struct value
*v
)
1503 gdb_assert (v
->lval
== lval_computed
);
1505 return v
->location
.computed
.closure
;
1509 deprecated_value_lval_hack (struct value
*value
)
1511 return &value
->lval
;
1515 value_lval_const (const struct value
*value
)
1521 value_address (const struct value
*value
)
1523 if (value
->lval
!= lval_memory
)
1525 if (value
->parent
!= NULL
)
1526 return value_address (value
->parent
.get ()) + value
->offset
;
1527 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1529 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1530 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1533 return value
->location
.address
+ value
->offset
;
1537 value_raw_address (const struct value
*value
)
1539 if (value
->lval
!= lval_memory
)
1541 return value
->location
.address
;
1545 set_value_address (struct value
*value
, CORE_ADDR addr
)
1547 gdb_assert (value
->lval
== lval_memory
);
1548 value
->location
.address
= addr
;
1551 struct internalvar
**
1552 deprecated_value_internalvar_hack (struct value
*value
)
1554 return &value
->location
.internalvar
;
1558 deprecated_value_next_frame_id_hack (struct value
*value
)
1560 gdb_assert (value
->lval
== lval_register
);
1561 return &value
->location
.reg
.next_frame_id
;
1565 deprecated_value_regnum_hack (struct value
*value
)
1567 gdb_assert (value
->lval
== lval_register
);
1568 return &value
->location
.reg
.regnum
;
1572 deprecated_value_modifiable (const struct value
*value
)
1574 return value
->modifiable
;
1577 /* Return a mark in the value chain. All values allocated after the
1578 mark is obtained (except for those released) are subject to being freed
1579 if a subsequent value_free_to_mark is passed the mark. */
1583 if (all_values
.empty ())
1585 return all_values
.back ().get ();
1591 value_incref (struct value
*val
)
1593 val
->reference_count
++;
1596 /* Release a reference to VAL, which was acquired with value_incref.
1597 This function is also called to deallocate values from the value
1601 value_decref (struct value
*val
)
1605 gdb_assert (val
->reference_count
> 0);
1606 val
->reference_count
--;
1607 if (val
->reference_count
== 0)
1612 /* Free all values allocated since MARK was obtained by value_mark
1613 (except for those released). */
1615 value_free_to_mark (const struct value
*mark
)
1617 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1618 if (iter
== all_values
.end ())
1619 all_values
.clear ();
1621 all_values
.erase (iter
+ 1, all_values
.end ());
1624 /* Remove VAL from the chain all_values
1625 so it will not be freed automatically. */
1628 release_value (struct value
*val
)
1631 return value_ref_ptr ();
1633 std::vector
<value_ref_ptr
>::reverse_iterator iter
;
1634 for (iter
= all_values
.rbegin (); iter
!= all_values
.rend (); ++iter
)
1638 value_ref_ptr result
= *iter
;
1639 all_values
.erase (iter
.base () - 1);
1644 /* We must always return an owned reference. Normally this happens
1645 because we transfer the reference from the value chain, but in
1646 this case the value was not on the chain. */
1647 return value_ref_ptr::new_reference (val
);
1652 std::vector
<value_ref_ptr
>
1653 value_release_to_mark (const struct value
*mark
)
1655 std::vector
<value_ref_ptr
> result
;
1657 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1658 if (iter
== all_values
.end ())
1659 std::swap (result
, all_values
);
1662 std::move (iter
+ 1, all_values
.end (), std::back_inserter (result
));
1663 all_values
.erase (iter
+ 1, all_values
.end ());
1665 std::reverse (result
.begin (), result
.end ());
1669 /* Return a copy of the value ARG.
1670 It contains the same contents, for same memory address,
1671 but it's a different block of storage. */
1674 value_copy (struct value
*arg
)
1676 struct type
*encl_type
= value_enclosing_type (arg
);
1679 if (value_lazy (arg
))
1680 val
= allocate_value_lazy (encl_type
);
1682 val
= allocate_value (encl_type
);
1683 val
->type
= arg
->type
;
1684 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1685 val
->location
= arg
->location
;
1686 val
->offset
= arg
->offset
;
1687 val
->bitpos
= arg
->bitpos
;
1688 val
->bitsize
= arg
->bitsize
;
1689 val
->lazy
= arg
->lazy
;
1690 val
->embedded_offset
= value_embedded_offset (arg
);
1691 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1692 val
->modifiable
= arg
->modifiable
;
1693 if (!value_lazy (val
))
1695 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1696 TYPE_LENGTH (value_enclosing_type (arg
)));
1699 val
->unavailable
= arg
->unavailable
;
1700 val
->optimized_out
= arg
->optimized_out
;
1701 val
->parent
= arg
->parent
;
1702 if (VALUE_LVAL (val
) == lval_computed
)
1704 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1706 if (funcs
->copy_closure
)
1707 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1712 /* Return a "const" and/or "volatile" qualified version of the value V.
1713 If CNST is true, then the returned value will be qualified with
1715 if VOLTL is true, then the returned value will be qualified with
1719 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1721 struct type
*val_type
= value_type (v
);
1722 struct type
*enclosing_type
= value_enclosing_type (v
);
1723 struct value
*cv_val
= value_copy (v
);
1725 deprecated_set_value_type (cv_val
,
1726 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1727 set_value_enclosing_type (cv_val
,
1728 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1733 /* Return a version of ARG that is non-lvalue. */
1736 value_non_lval (struct value
*arg
)
1738 if (VALUE_LVAL (arg
) != not_lval
)
1740 struct type
*enc_type
= value_enclosing_type (arg
);
1741 struct value
*val
= allocate_value (enc_type
);
1743 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1744 TYPE_LENGTH (enc_type
));
1745 val
->type
= arg
->type
;
1746 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1747 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1753 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1756 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1758 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1760 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1761 v
->lval
= lval_memory
;
1762 v
->location
.address
= addr
;
1766 set_value_component_location (struct value
*component
,
1767 const struct value
*whole
)
1771 gdb_assert (whole
->lval
!= lval_xcallable
);
1773 if (whole
->lval
== lval_internalvar
)
1774 VALUE_LVAL (component
) = lval_internalvar_component
;
1776 VALUE_LVAL (component
) = whole
->lval
;
1778 component
->location
= whole
->location
;
1779 if (whole
->lval
== lval_computed
)
1781 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1783 if (funcs
->copy_closure
)
1784 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1787 /* If type has a dynamic resolved location property
1788 update it's value address. */
1789 type
= value_type (whole
);
1790 if (NULL
!= TYPE_DATA_LOCATION (type
)
1791 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1792 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1795 /* Access to the value history. */
1797 /* Record a new value in the value history.
1798 Returns the absolute history index of the entry. */
1801 record_latest_value (struct value
*val
)
1803 /* We don't want this value to have anything to do with the inferior anymore.
1804 In particular, "set $1 = 50" should not affect the variable from which
1805 the value was taken, and fast watchpoints should be able to assume that
1806 a value on the value history never changes. */
1807 if (value_lazy (val
))
1808 value_fetch_lazy (val
);
1809 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1810 from. This is a bit dubious, because then *&$1 does not just return $1
1811 but the current contents of that location. c'est la vie... */
1812 val
->modifiable
= 0;
1814 value_history
.push_back (release_value (val
));
1816 return value_history
.size ();
1819 /* Return a copy of the value in the history with sequence number NUM. */
1822 access_value_history (int num
)
1827 absnum
+= value_history
.size ();
1832 error (_("The history is empty."));
1834 error (_("There is only one value in the history."));
1836 error (_("History does not go back to $$%d."), -num
);
1838 if (absnum
> value_history
.size ())
1839 error (_("History has not yet reached $%d."), absnum
);
1843 return value_copy (value_history
[absnum
].get ());
1847 show_values (const char *num_exp
, int from_tty
)
1855 /* "show values +" should print from the stored position.
1856 "show values <exp>" should print around value number <exp>. */
1857 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1858 num
= parse_and_eval_long (num_exp
) - 5;
1862 /* "show values" means print the last 10 values. */
1863 num
= value_history
.size () - 9;
1869 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1871 struct value_print_options opts
;
1873 val
= access_value_history (i
);
1874 printf_filtered (("$%d = "), i
);
1875 get_user_print_options (&opts
);
1876 value_print (val
, gdb_stdout
, &opts
);
1877 printf_filtered (("\n"));
1880 /* The next "show values +" should start after what we just printed. */
1883 /* Hitting just return after this command should do the same thing as
1884 "show values +". If num_exp is null, this is unnecessary, since
1885 "show values +" is not useful after "show values". */
1886 if (from_tty
&& num_exp
)
1887 set_repeat_arguments ("+");
1890 enum internalvar_kind
1892 /* The internal variable is empty. */
1895 /* The value of the internal variable is provided directly as
1896 a GDB value object. */
1899 /* A fresh value is computed via a call-back routine on every
1900 access to the internal variable. */
1901 INTERNALVAR_MAKE_VALUE
,
1903 /* The internal variable holds a GDB internal convenience function. */
1904 INTERNALVAR_FUNCTION
,
1906 /* The variable holds an integer value. */
1907 INTERNALVAR_INTEGER
,
1909 /* The variable holds a GDB-provided string. */
1913 union internalvar_data
1915 /* A value object used with INTERNALVAR_VALUE. */
1916 struct value
*value
;
1918 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1921 /* The functions to call. */
1922 const struct internalvar_funcs
*functions
;
1924 /* The function's user-data. */
1928 /* The internal function used with INTERNALVAR_FUNCTION. */
1931 struct internal_function
*function
;
1932 /* True if this is the canonical name for the function. */
1936 /* An integer value used with INTERNALVAR_INTEGER. */
1939 /* If type is non-NULL, it will be used as the type to generate
1940 a value for this internal variable. If type is NULL, a default
1941 integer type for the architecture is used. */
1946 /* A string value used with INTERNALVAR_STRING. */
1950 /* Internal variables. These are variables within the debugger
1951 that hold values assigned by debugger commands.
1952 The user refers to them with a '$' prefix
1953 that does not appear in the variable names stored internally. */
1957 struct internalvar
*next
;
1960 /* We support various different kinds of content of an internal variable.
1961 enum internalvar_kind specifies the kind, and union internalvar_data
1962 provides the data associated with this particular kind. */
1964 enum internalvar_kind kind
;
1966 union internalvar_data u
;
1969 static struct internalvar
*internalvars
;
1971 /* If the variable does not already exist create it and give it the
1972 value given. If no value is given then the default is zero. */
1974 init_if_undefined_command (const char* args
, int from_tty
)
1976 struct internalvar
* intvar
;
1978 /* Parse the expression - this is taken from set_command(). */
1979 expression_up expr
= parse_expression (args
);
1981 /* Validate the expression.
1982 Was the expression an assignment?
1983 Or even an expression at all? */
1984 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1985 error (_("Init-if-undefined requires an assignment expression."));
1987 /* Extract the variable from the parsed expression.
1988 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1989 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1990 error (_("The first parameter to init-if-undefined "
1991 "should be a GDB variable."));
1992 intvar
= expr
->elts
[2].internalvar
;
1994 /* Only evaluate the expression if the lvalue is void.
1995 This may still fail if the expression is invalid. */
1996 if (intvar
->kind
== INTERNALVAR_VOID
)
1997 evaluate_expression (expr
.get ());
2001 /* Look up an internal variable with name NAME. NAME should not
2002 normally include a dollar sign.
2004 If the specified internal variable does not exist,
2005 the return value is NULL. */
2007 struct internalvar
*
2008 lookup_only_internalvar (const char *name
)
2010 struct internalvar
*var
;
2012 for (var
= internalvars
; var
; var
= var
->next
)
2013 if (strcmp (var
->name
, name
) == 0)
2019 /* Complete NAME by comparing it to the names of internal
2023 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2025 struct internalvar
*var
;
2028 len
= strlen (name
);
2030 for (var
= internalvars
; var
; var
= var
->next
)
2031 if (strncmp (var
->name
, name
, len
) == 0)
2032 tracker
.add_completion (make_unique_xstrdup (var
->name
));
2035 /* Create an internal variable with name NAME and with a void value.
2036 NAME should not normally include a dollar sign. */
2038 struct internalvar
*
2039 create_internalvar (const char *name
)
2041 struct internalvar
*var
= XNEW (struct internalvar
);
2043 var
->name
= xstrdup (name
);
2044 var
->kind
= INTERNALVAR_VOID
;
2045 var
->next
= internalvars
;
2050 /* Create an internal variable with name NAME and register FUN as the
2051 function that value_of_internalvar uses to create a value whenever
2052 this variable is referenced. NAME should not normally include a
2053 dollar sign. DATA is passed uninterpreted to FUN when it is
2054 called. CLEANUP, if not NULL, is called when the internal variable
2055 is destroyed. It is passed DATA as its only argument. */
2057 struct internalvar
*
2058 create_internalvar_type_lazy (const char *name
,
2059 const struct internalvar_funcs
*funcs
,
2062 struct internalvar
*var
= create_internalvar (name
);
2064 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2065 var
->u
.make_value
.functions
= funcs
;
2066 var
->u
.make_value
.data
= data
;
2070 /* See documentation in value.h. */
2073 compile_internalvar_to_ax (struct internalvar
*var
,
2074 struct agent_expr
*expr
,
2075 struct axs_value
*value
)
2077 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2078 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2081 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2082 var
->u
.make_value
.data
);
2086 /* Look up an internal variable with name NAME. NAME should not
2087 normally include a dollar sign.
2089 If the specified internal variable does not exist,
2090 one is created, with a void value. */
2092 struct internalvar
*
2093 lookup_internalvar (const char *name
)
2095 struct internalvar
*var
;
2097 var
= lookup_only_internalvar (name
);
2101 return create_internalvar (name
);
2104 /* Return current value of internal variable VAR. For variables that
2105 are not inherently typed, use a value type appropriate for GDBARCH. */
2108 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2111 struct trace_state_variable
*tsv
;
2113 /* If there is a trace state variable of the same name, assume that
2114 is what we really want to see. */
2115 tsv
= find_trace_state_variable (var
->name
);
2118 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2120 if (tsv
->value_known
)
2121 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2124 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2130 case INTERNALVAR_VOID
:
2131 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2134 case INTERNALVAR_FUNCTION
:
2135 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2138 case INTERNALVAR_INTEGER
:
2139 if (!var
->u
.integer
.type
)
2140 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2141 var
->u
.integer
.val
);
2143 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2146 case INTERNALVAR_STRING
:
2147 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2148 builtin_type (gdbarch
)->builtin_char
);
2151 case INTERNALVAR_VALUE
:
2152 val
= value_copy (var
->u
.value
);
2153 if (value_lazy (val
))
2154 value_fetch_lazy (val
);
2157 case INTERNALVAR_MAKE_VALUE
:
2158 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2159 var
->u
.make_value
.data
);
2163 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2166 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2167 on this value go back to affect the original internal variable.
2169 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2170 no underlying modifiable state in the internal variable.
2172 Likewise, if the variable's value is a computed lvalue, we want
2173 references to it to produce another computed lvalue, where
2174 references and assignments actually operate through the
2175 computed value's functions.
2177 This means that internal variables with computed values
2178 behave a little differently from other internal variables:
2179 assignments to them don't just replace the previous value
2180 altogether. At the moment, this seems like the behavior we
2183 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2184 && val
->lval
!= lval_computed
)
2186 VALUE_LVAL (val
) = lval_internalvar
;
2187 VALUE_INTERNALVAR (val
) = var
;
2194 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2196 if (var
->kind
== INTERNALVAR_INTEGER
)
2198 *result
= var
->u
.integer
.val
;
2202 if (var
->kind
== INTERNALVAR_VALUE
)
2204 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2206 if (type
->code () == TYPE_CODE_INT
)
2208 *result
= value_as_long (var
->u
.value
);
2217 get_internalvar_function (struct internalvar
*var
,
2218 struct internal_function
**result
)
2222 case INTERNALVAR_FUNCTION
:
2223 *result
= var
->u
.fn
.function
;
2232 set_internalvar_component (struct internalvar
*var
,
2233 LONGEST offset
, LONGEST bitpos
,
2234 LONGEST bitsize
, struct value
*newval
)
2237 struct gdbarch
*arch
;
2242 case INTERNALVAR_VALUE
:
2243 addr
= value_contents_writeable (var
->u
.value
);
2244 arch
= get_value_arch (var
->u
.value
);
2245 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2248 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2249 value_as_long (newval
), bitpos
, bitsize
);
2251 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2252 TYPE_LENGTH (value_type (newval
)));
2256 /* We can never get a component of any other kind. */
2257 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2262 set_internalvar (struct internalvar
*var
, struct value
*val
)
2264 enum internalvar_kind new_kind
;
2265 union internalvar_data new_data
= { 0 };
2267 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2268 error (_("Cannot overwrite convenience function %s"), var
->name
);
2270 /* Prepare new contents. */
2271 switch (check_typedef (value_type (val
))->code ())
2273 case TYPE_CODE_VOID
:
2274 new_kind
= INTERNALVAR_VOID
;
2277 case TYPE_CODE_INTERNAL_FUNCTION
:
2278 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2279 new_kind
= INTERNALVAR_FUNCTION
;
2280 get_internalvar_function (VALUE_INTERNALVAR (val
),
2281 &new_data
.fn
.function
);
2282 /* Copies created here are never canonical. */
2286 new_kind
= INTERNALVAR_VALUE
;
2287 struct value
*copy
= value_copy (val
);
2288 copy
->modifiable
= 1;
2290 /* Force the value to be fetched from the target now, to avoid problems
2291 later when this internalvar is referenced and the target is gone or
2293 if (value_lazy (copy
))
2294 value_fetch_lazy (copy
);
2296 /* Release the value from the value chain to prevent it from being
2297 deleted by free_all_values. From here on this function should not
2298 call error () until new_data is installed into the var->u to avoid
2300 new_data
.value
= release_value (copy
).release ();
2302 /* Internal variables which are created from values with a dynamic
2303 location don't need the location property of the origin anymore.
2304 The resolved dynamic location is used prior then any other address
2305 when accessing the value.
2306 If we keep it, we would still refer to the origin value.
2307 Remove the location property in case it exist. */
2308 value_type (new_data
.value
)->remove_dyn_prop (DYN_PROP_DATA_LOCATION
);
2313 /* Clean up old contents. */
2314 clear_internalvar (var
);
2317 var
->kind
= new_kind
;
2319 /* End code which must not call error(). */
2323 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2325 /* Clean up old contents. */
2326 clear_internalvar (var
);
2328 var
->kind
= INTERNALVAR_INTEGER
;
2329 var
->u
.integer
.type
= NULL
;
2330 var
->u
.integer
.val
= l
;
2334 set_internalvar_string (struct internalvar
*var
, const char *string
)
2336 /* Clean up old contents. */
2337 clear_internalvar (var
);
2339 var
->kind
= INTERNALVAR_STRING
;
2340 var
->u
.string
= xstrdup (string
);
2344 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2346 /* Clean up old contents. */
2347 clear_internalvar (var
);
2349 var
->kind
= INTERNALVAR_FUNCTION
;
2350 var
->u
.fn
.function
= f
;
2351 var
->u
.fn
.canonical
= 1;
2352 /* Variables installed here are always the canonical version. */
2356 clear_internalvar (struct internalvar
*var
)
2358 /* Clean up old contents. */
2361 case INTERNALVAR_VALUE
:
2362 value_decref (var
->u
.value
);
2365 case INTERNALVAR_STRING
:
2366 xfree (var
->u
.string
);
2369 case INTERNALVAR_MAKE_VALUE
:
2370 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2371 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2378 /* Reset to void kind. */
2379 var
->kind
= INTERNALVAR_VOID
;
2383 internalvar_name (const struct internalvar
*var
)
2388 static struct internal_function
*
2389 create_internal_function (const char *name
,
2390 internal_function_fn handler
, void *cookie
)
2392 struct internal_function
*ifn
= XNEW (struct internal_function
);
2394 ifn
->name
= xstrdup (name
);
2395 ifn
->handler
= handler
;
2396 ifn
->cookie
= cookie
;
2401 value_internal_function_name (struct value
*val
)
2403 struct internal_function
*ifn
;
2406 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2407 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2408 gdb_assert (result
);
2414 call_internal_function (struct gdbarch
*gdbarch
,
2415 const struct language_defn
*language
,
2416 struct value
*func
, int argc
, struct value
**argv
)
2418 struct internal_function
*ifn
;
2421 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2422 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2423 gdb_assert (result
);
2425 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2428 /* The 'function' command. This does nothing -- it is just a
2429 placeholder to let "help function NAME" work. This is also used as
2430 the implementation of the sub-command that is created when
2431 registering an internal function. */
2433 function_command (const char *command
, int from_tty
)
2438 /* Helper function that does the work for add_internal_function. */
2440 static struct cmd_list_element
*
2441 do_add_internal_function (const char *name
, const char *doc
,
2442 internal_function_fn handler
, void *cookie
)
2444 struct internal_function
*ifn
;
2445 struct internalvar
*var
= lookup_internalvar (name
);
2447 ifn
= create_internal_function (name
, handler
, cookie
);
2448 set_internalvar_function (var
, ifn
);
2450 return add_cmd (name
, no_class
, function_command
, doc
, &functionlist
);
2456 add_internal_function (const char *name
, const char *doc
,
2457 internal_function_fn handler
, void *cookie
)
2459 do_add_internal_function (name
, doc
, handler
, cookie
);
2465 add_internal_function (gdb::unique_xmalloc_ptr
<char> &&name
,
2466 gdb::unique_xmalloc_ptr
<char> &&doc
,
2467 internal_function_fn handler
, void *cookie
)
2469 struct cmd_list_element
*cmd
2470 = do_add_internal_function (name
.get (), doc
.get (), handler
, cookie
);
2472 cmd
->doc_allocated
= 1;
2474 cmd
->name_allocated
= 1;
2477 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2478 prevent cycles / duplicates. */
2481 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2482 htab_t copied_types
)
2484 if (TYPE_OBJFILE (value
->type
) == objfile
)
2485 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2487 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2488 value
->enclosing_type
= copy_type_recursive (objfile
,
2489 value
->enclosing_type
,
2493 /* Likewise for internal variable VAR. */
2496 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2497 htab_t copied_types
)
2501 case INTERNALVAR_INTEGER
:
2502 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2504 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2507 case INTERNALVAR_VALUE
:
2508 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2513 /* Update the internal variables and value history when OBJFILE is
2514 discarded; we must copy the types out of the objfile. New global types
2515 will be created for every convenience variable which currently points to
2516 this objfile's types, and the convenience variables will be adjusted to
2517 use the new global types. */
2520 preserve_values (struct objfile
*objfile
)
2522 htab_t copied_types
;
2523 struct internalvar
*var
;
2525 /* Create the hash table. We allocate on the objfile's obstack, since
2526 it is soon to be deleted. */
2527 copied_types
= create_copied_types_hash (objfile
);
2529 for (const value_ref_ptr
&item
: value_history
)
2530 preserve_one_value (item
.get (), objfile
, copied_types
);
2532 for (var
= internalvars
; var
; var
= var
->next
)
2533 preserve_one_internalvar (var
, objfile
, copied_types
);
2535 preserve_ext_lang_values (objfile
, copied_types
);
2537 htab_delete (copied_types
);
2541 show_convenience (const char *ignore
, int from_tty
)
2543 struct gdbarch
*gdbarch
= get_current_arch ();
2544 struct internalvar
*var
;
2546 struct value_print_options opts
;
2548 get_user_print_options (&opts
);
2549 for (var
= internalvars
; var
; var
= var
->next
)
2556 printf_filtered (("$%s = "), var
->name
);
2562 val
= value_of_internalvar (gdbarch
, var
);
2563 value_print (val
, gdb_stdout
, &opts
);
2565 catch (const gdb_exception_error
&ex
)
2567 fprintf_styled (gdb_stdout
, metadata_style
.style (),
2568 _("<error: %s>"), ex
.what ());
2571 printf_filtered (("\n"));
2575 /* This text does not mention convenience functions on purpose.
2576 The user can't create them except via Python, and if Python support
2577 is installed this message will never be printed ($_streq will
2579 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2580 "Convenience variables have "
2581 "names starting with \"$\";\n"
2582 "use \"set\" as in \"set "
2583 "$foo = 5\" to define them.\n"));
2591 value_from_xmethod (xmethod_worker_up
&&worker
)
2595 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2596 v
->lval
= lval_xcallable
;
2597 v
->location
.xm_worker
= worker
.release ();
2603 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2606 result_type_of_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2608 gdb_assert (value_type (method
)->code () == TYPE_CODE_XMETHOD
2609 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2611 return method
->location
.xm_worker
->get_result_type (argv
[0], argv
.slice (1));
2614 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2617 call_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2619 gdb_assert (value_type (method
)->code () == TYPE_CODE_XMETHOD
2620 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2622 return method
->location
.xm_worker
->invoke (argv
[0], argv
.slice (1));
2625 /* Extract a value as a C number (either long or double).
2626 Knows how to convert fixed values to double, or
2627 floating values to long.
2628 Does not deallocate the value. */
2631 value_as_long (struct value
*val
)
2633 /* This coerces arrays and functions, which is necessary (e.g.
2634 in disassemble_command). It also dereferences references, which
2635 I suspect is the most logical thing to do. */
2636 val
= coerce_array (val
);
2637 return unpack_long (value_type (val
), value_contents (val
));
2640 /* Extract a value as a C pointer. Does not deallocate the value.
2641 Note that val's type may not actually be a pointer; value_as_long
2642 handles all the cases. */
2644 value_as_address (struct value
*val
)
2646 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2648 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2649 whether we want this to be true eventually. */
2651 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2652 non-address (e.g. argument to "signal", "info break", etc.), or
2653 for pointers to char, in which the low bits *are* significant. */
2654 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2657 /* There are several targets (IA-64, PowerPC, and others) which
2658 don't represent pointers to functions as simply the address of
2659 the function's entry point. For example, on the IA-64, a
2660 function pointer points to a two-word descriptor, generated by
2661 the linker, which contains the function's entry point, and the
2662 value the IA-64 "global pointer" register should have --- to
2663 support position-independent code. The linker generates
2664 descriptors only for those functions whose addresses are taken.
2666 On such targets, it's difficult for GDB to convert an arbitrary
2667 function address into a function pointer; it has to either find
2668 an existing descriptor for that function, or call malloc and
2669 build its own. On some targets, it is impossible for GDB to
2670 build a descriptor at all: the descriptor must contain a jump
2671 instruction; data memory cannot be executed; and code memory
2674 Upon entry to this function, if VAL is a value of type `function'
2675 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2676 value_address (val) is the address of the function. This is what
2677 you'll get if you evaluate an expression like `main'. The call
2678 to COERCE_ARRAY below actually does all the usual unary
2679 conversions, which includes converting values of type `function'
2680 to `pointer to function'. This is the challenging conversion
2681 discussed above. Then, `unpack_long' will convert that pointer
2682 back into an address.
2684 So, suppose the user types `disassemble foo' on an architecture
2685 with a strange function pointer representation, on which GDB
2686 cannot build its own descriptors, and suppose further that `foo'
2687 has no linker-built descriptor. The address->pointer conversion
2688 will signal an error and prevent the command from running, even
2689 though the next step would have been to convert the pointer
2690 directly back into the same address.
2692 The following shortcut avoids this whole mess. If VAL is a
2693 function, just return its address directly. */
2694 if (value_type (val
)->code () == TYPE_CODE_FUNC
2695 || value_type (val
)->code () == TYPE_CODE_METHOD
)
2696 return value_address (val
);
2698 val
= coerce_array (val
);
2700 /* Some architectures (e.g. Harvard), map instruction and data
2701 addresses onto a single large unified address space. For
2702 instance: An architecture may consider a large integer in the
2703 range 0x10000000 .. 0x1000ffff to already represent a data
2704 addresses (hence not need a pointer to address conversion) while
2705 a small integer would still need to be converted integer to
2706 pointer to address. Just assume such architectures handle all
2707 integer conversions in a single function. */
2711 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2712 must admonish GDB hackers to make sure its behavior matches the
2713 compiler's, whenever possible.
2715 In general, I think GDB should evaluate expressions the same way
2716 the compiler does. When the user copies an expression out of
2717 their source code and hands it to a `print' command, they should
2718 get the same value the compiler would have computed. Any
2719 deviation from this rule can cause major confusion and annoyance,
2720 and needs to be justified carefully. In other words, GDB doesn't
2721 really have the freedom to do these conversions in clever and
2724 AndrewC pointed out that users aren't complaining about how GDB
2725 casts integers to pointers; they are complaining that they can't
2726 take an address from a disassembly listing and give it to `x/i'.
2727 This is certainly important.
2729 Adding an architecture method like integer_to_address() certainly
2730 makes it possible for GDB to "get it right" in all circumstances
2731 --- the target has complete control over how things get done, so
2732 people can Do The Right Thing for their target without breaking
2733 anyone else. The standard doesn't specify how integers get
2734 converted to pointers; usually, the ABI doesn't either, but
2735 ABI-specific code is a more reasonable place to handle it. */
2737 if (value_type (val
)->code () != TYPE_CODE_PTR
2738 && !TYPE_IS_REFERENCE (value_type (val
))
2739 && gdbarch_integer_to_address_p (gdbarch
))
2740 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2741 value_contents (val
));
2743 return unpack_long (value_type (val
), value_contents (val
));
2747 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2748 as a long, or as a double, assuming the raw data is described
2749 by type TYPE. Knows how to convert different sizes of values
2750 and can convert between fixed and floating point. We don't assume
2751 any alignment for the raw data. Return value is in host byte order.
2753 If you want functions and arrays to be coerced to pointers, and
2754 references to be dereferenced, call value_as_long() instead.
2756 C++: It is assumed that the front-end has taken care of
2757 all matters concerning pointers to members. A pointer
2758 to member which reaches here is considered to be equivalent
2759 to an INT (or some size). After all, it is only an offset. */
2762 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2764 enum bfd_endian byte_order
= type_byte_order (type
);
2765 enum type_code code
= type
->code ();
2766 int len
= TYPE_LENGTH (type
);
2767 int nosign
= type
->is_unsigned ();
2771 case TYPE_CODE_TYPEDEF
:
2772 return unpack_long (check_typedef (type
), valaddr
);
2773 case TYPE_CODE_ENUM
:
2774 case TYPE_CODE_FLAGS
:
2775 case TYPE_CODE_BOOL
:
2777 case TYPE_CODE_CHAR
:
2778 case TYPE_CODE_RANGE
:
2779 case TYPE_CODE_MEMBERPTR
:
2783 result
= extract_unsigned_integer (valaddr
, len
, byte_order
);
2785 result
= extract_signed_integer (valaddr
, len
, byte_order
);
2786 if (code
== TYPE_CODE_RANGE
)
2787 result
+= type
->bounds ()->bias
;
2792 case TYPE_CODE_DECFLOAT
:
2793 return target_float_to_longest (valaddr
, type
);
2797 case TYPE_CODE_RVALUE_REF
:
2798 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2799 whether we want this to be true eventually. */
2800 return extract_typed_address (valaddr
, type
);
2803 error (_("Value can't be converted to integer."));
2807 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2808 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2809 We don't assume any alignment for the raw data. Return value is in
2812 If you want functions and arrays to be coerced to pointers, and
2813 references to be dereferenced, call value_as_address() instead.
2815 C++: It is assumed that the front-end has taken care of
2816 all matters concerning pointers to members. A pointer
2817 to member which reaches here is considered to be equivalent
2818 to an INT (or some size). After all, it is only an offset. */
2821 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2823 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2824 whether we want this to be true eventually. */
2825 return unpack_long (type
, valaddr
);
2829 is_floating_value (struct value
*val
)
2831 struct type
*type
= check_typedef (value_type (val
));
2833 if (is_floating_type (type
))
2835 if (!target_float_is_valid (value_contents (val
), type
))
2836 error (_("Invalid floating value found in program."));
2844 /* Get the value of the FIELDNO'th field (which must be static) of
2848 value_static_field (struct type
*type
, int fieldno
)
2850 struct value
*retval
;
2852 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2854 case FIELD_LOC_KIND_PHYSADDR
:
2855 retval
= value_at_lazy (type
->field (fieldno
).type (),
2856 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2858 case FIELD_LOC_KIND_PHYSNAME
:
2860 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2861 /* TYPE_FIELD_NAME (type, fieldno); */
2862 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2864 if (sym
.symbol
== NULL
)
2866 /* With some compilers, e.g. HP aCC, static data members are
2867 reported as non-debuggable symbols. */
2868 struct bound_minimal_symbol msym
2869 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2870 struct type
*field_type
= type
->field (fieldno
).type ();
2873 retval
= allocate_optimized_out_value (field_type
);
2875 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2878 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2882 gdb_assert_not_reached ("unexpected field location kind");
2888 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2889 You have to be careful here, since the size of the data area for the value
2890 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2891 than the old enclosing type, you have to allocate more space for the
2895 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2897 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2899 check_type_length_before_alloc (new_encl_type
);
2901 .reset ((gdb_byte
*) xrealloc (val
->contents
.release (),
2902 TYPE_LENGTH (new_encl_type
)));
2905 val
->enclosing_type
= new_encl_type
;
2908 /* Given a value ARG1 (offset by OFFSET bytes)
2909 of a struct or union type ARG_TYPE,
2910 extract and return the value of one of its (non-static) fields.
2911 FIELDNO says which field. */
2914 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2915 int fieldno
, struct type
*arg_type
)
2919 struct gdbarch
*arch
= get_value_arch (arg1
);
2920 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2922 arg_type
= check_typedef (arg_type
);
2923 type
= arg_type
->field (fieldno
).type ();
2925 /* Call check_typedef on our type to make sure that, if TYPE
2926 is a TYPE_CODE_TYPEDEF, its length is set to the length
2927 of the target type instead of zero. However, we do not
2928 replace the typedef type by the target type, because we want
2929 to keep the typedef in order to be able to print the type
2930 description correctly. */
2931 check_typedef (type
);
2933 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2935 /* Handle packed fields.
2937 Create a new value for the bitfield, with bitpos and bitsize
2938 set. If possible, arrange offset and bitpos so that we can
2939 do a single aligned read of the size of the containing type.
2940 Otherwise, adjust offset to the byte containing the first
2941 bit. Assume that the address, offset, and embedded offset
2942 are sufficiently aligned. */
2944 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2945 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2947 v
= allocate_value_lazy (type
);
2948 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2949 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2950 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2951 v
->bitpos
= bitpos
% container_bitsize
;
2953 v
->bitpos
= bitpos
% 8;
2954 v
->offset
= (value_embedded_offset (arg1
)
2956 + (bitpos
- v
->bitpos
) / 8);
2957 set_value_parent (v
, arg1
);
2958 if (!value_lazy (arg1
))
2959 value_fetch_lazy (v
);
2961 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2963 /* This field is actually a base subobject, so preserve the
2964 entire object's contents for later references to virtual
2968 /* Lazy register values with offsets are not supported. */
2969 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2970 value_fetch_lazy (arg1
);
2972 /* We special case virtual inheritance here because this
2973 requires access to the contents, which we would rather avoid
2974 for references to ordinary fields of unavailable values. */
2975 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2976 boffset
= baseclass_offset (arg_type
, fieldno
,
2977 value_contents (arg1
),
2978 value_embedded_offset (arg1
),
2979 value_address (arg1
),
2982 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2984 if (value_lazy (arg1
))
2985 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2988 v
= allocate_value (value_enclosing_type (arg1
));
2989 value_contents_copy_raw (v
, 0, arg1
, 0,
2990 TYPE_LENGTH (value_enclosing_type (arg1
)));
2993 v
->offset
= value_offset (arg1
);
2994 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2996 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2998 /* Field is a dynamic data member. */
3000 gdb_assert (0 == offset
);
3001 /* We expect an already resolved data location. */
3002 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3003 /* For dynamic data types defer memory allocation
3004 until we actual access the value. */
3005 v
= allocate_value_lazy (type
);
3009 /* Plain old data member */
3010 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3011 / (HOST_CHAR_BIT
* unit_size
));
3013 /* Lazy register values with offsets are not supported. */
3014 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3015 value_fetch_lazy (arg1
);
3017 if (value_lazy (arg1
))
3018 v
= allocate_value_lazy (type
);
3021 v
= allocate_value (type
);
3022 value_contents_copy_raw (v
, value_embedded_offset (v
),
3023 arg1
, value_embedded_offset (arg1
) + offset
,
3024 type_length_units (type
));
3026 v
->offset
= (value_offset (arg1
) + offset
3027 + value_embedded_offset (arg1
));
3029 set_value_component_location (v
, arg1
);
3033 /* Given a value ARG1 of a struct or union type,
3034 extract and return the value of one of its (non-static) fields.
3035 FIELDNO says which field. */
3038 value_field (struct value
*arg1
, int fieldno
)
3040 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3043 /* Return a non-virtual function as a value.
3044 F is the list of member functions which contains the desired method.
3045 J is an index into F which provides the desired method.
3047 We only use the symbol for its address, so be happy with either a
3048 full symbol or a minimal symbol. */
3051 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3052 int j
, struct type
*type
,
3056 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3057 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3059 struct bound_minimal_symbol msym
;
3061 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3064 memset (&msym
, 0, sizeof (msym
));
3068 gdb_assert (sym
== NULL
);
3069 msym
= lookup_bound_minimal_symbol (physname
);
3070 if (msym
.minsym
== NULL
)
3074 v
= allocate_value (ftype
);
3075 VALUE_LVAL (v
) = lval_memory
;
3078 set_value_address (v
, BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (sym
)));
3082 /* The minimal symbol might point to a function descriptor;
3083 resolve it to the actual code address instead. */
3084 struct objfile
*objfile
= msym
.objfile
;
3085 struct gdbarch
*gdbarch
= objfile
->arch ();
3087 set_value_address (v
,
3088 gdbarch_convert_from_func_ptr_addr
3089 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), current_top_target ()));
3094 if (type
!= value_type (*arg1p
))
3095 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3096 value_addr (*arg1p
)));
3098 /* Move the `this' pointer according to the offset.
3099 VALUE_OFFSET (*arg1p) += offset; */
3110 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3111 LONGEST bitpos
, LONGEST bitsize
)
3113 enum bfd_endian byte_order
= type_byte_order (field_type
);
3118 LONGEST read_offset
;
3120 /* Read the minimum number of bytes required; there may not be
3121 enough bytes to read an entire ULONGEST. */
3122 field_type
= check_typedef (field_type
);
3124 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3127 bytes_read
= TYPE_LENGTH (field_type
);
3128 bitsize
= 8 * bytes_read
;
3131 read_offset
= bitpos
/ 8;
3133 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3134 bytes_read
, byte_order
);
3136 /* Extract bits. See comment above. */
3138 if (byte_order
== BFD_ENDIAN_BIG
)
3139 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3141 lsbcount
= (bitpos
% 8);
3144 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3145 If the field is signed, and is negative, then sign extend. */
3147 if (bitsize
< 8 * (int) sizeof (val
))
3149 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3151 if (!field_type
->is_unsigned ())
3153 if (val
& (valmask
^ (valmask
>> 1)))
3163 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3164 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3165 ORIGINAL_VALUE, which must not be NULL. See
3166 unpack_value_bits_as_long for more details. */
3169 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3170 LONGEST embedded_offset
, int fieldno
,
3171 const struct value
*val
, LONGEST
*result
)
3173 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3174 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3175 struct type
*field_type
= type
->field (fieldno
).type ();
3178 gdb_assert (val
!= NULL
);
3180 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3181 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3182 || !value_bits_available (val
, bit_offset
, bitsize
))
3185 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3190 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3191 object at VALADDR. See unpack_bits_as_long for more details. */
3194 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3196 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3197 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3198 struct type
*field_type
= type
->field (fieldno
).type ();
3200 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3203 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3204 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3205 the contents in DEST_VAL, zero or sign extending if the type of
3206 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3207 VAL. If the VAL's contents required to extract the bitfield from
3208 are unavailable/optimized out, DEST_VAL is correspondingly
3209 marked unavailable/optimized out. */
3212 unpack_value_bitfield (struct value
*dest_val
,
3213 LONGEST bitpos
, LONGEST bitsize
,
3214 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3215 const struct value
*val
)
3217 enum bfd_endian byte_order
;
3220 struct type
*field_type
= value_type (dest_val
);
3222 byte_order
= type_byte_order (field_type
);
3224 /* First, unpack and sign extend the bitfield as if it was wholly
3225 valid. Optimized out/unavailable bits are read as zero, but
3226 that's OK, as they'll end up marked below. If the VAL is
3227 wholly-invalid we may have skipped allocating its contents,
3228 though. See allocate_optimized_out_value. */
3229 if (valaddr
!= NULL
)
3233 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3235 store_signed_integer (value_contents_raw (dest_val
),
3236 TYPE_LENGTH (field_type
), byte_order
, num
);
3239 /* Now copy the optimized out / unavailability ranges to the right
3241 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3242 if (byte_order
== BFD_ENDIAN_BIG
)
3243 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3246 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3247 val
, src_bit_offset
, bitsize
);
3250 /* Return a new value with type TYPE, which is FIELDNO field of the
3251 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3252 of VAL. If the VAL's contents required to extract the bitfield
3253 from are unavailable/optimized out, the new value is
3254 correspondingly marked unavailable/optimized out. */
3257 value_field_bitfield (struct type
*type
, int fieldno
,
3258 const gdb_byte
*valaddr
,
3259 LONGEST embedded_offset
, const struct value
*val
)
3261 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3262 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3263 struct value
*res_val
= allocate_value (type
->field (fieldno
).type ());
3265 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3266 valaddr
, embedded_offset
, val
);
3271 /* Modify the value of a bitfield. ADDR points to a block of memory in
3272 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3273 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3274 indicate which bits (in target bit order) comprise the bitfield.
3275 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3276 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3279 modify_field (struct type
*type
, gdb_byte
*addr
,
3280 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3282 enum bfd_endian byte_order
= type_byte_order (type
);
3284 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3287 /* Normalize BITPOS. */
3291 /* If a negative fieldval fits in the field in question, chop
3292 off the sign extension bits. */
3293 if ((~fieldval
& ~(mask
>> 1)) == 0)
3296 /* Warn if value is too big to fit in the field in question. */
3297 if (0 != (fieldval
& ~mask
))
3299 /* FIXME: would like to include fieldval in the message, but
3300 we don't have a sprintf_longest. */
3301 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3303 /* Truncate it, otherwise adjoining fields may be corrupted. */
3307 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3308 false valgrind reports. */
3310 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3311 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3313 /* Shifting for bit field depends on endianness of the target machine. */
3314 if (byte_order
== BFD_ENDIAN_BIG
)
3315 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3317 oword
&= ~(mask
<< bitpos
);
3318 oword
|= fieldval
<< bitpos
;
3320 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3323 /* Pack NUM into BUF using a target format of TYPE. */
3326 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3328 enum bfd_endian byte_order
= type_byte_order (type
);
3331 type
= check_typedef (type
);
3332 len
= TYPE_LENGTH (type
);
3334 switch (type
->code ())
3336 case TYPE_CODE_RANGE
:
3337 num
-= type
->bounds ()->bias
;
3340 case TYPE_CODE_CHAR
:
3341 case TYPE_CODE_ENUM
:
3342 case TYPE_CODE_FLAGS
:
3343 case TYPE_CODE_BOOL
:
3344 case TYPE_CODE_MEMBERPTR
:
3345 store_signed_integer (buf
, len
, byte_order
, num
);
3349 case TYPE_CODE_RVALUE_REF
:
3351 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3355 case TYPE_CODE_DECFLOAT
:
3356 target_float_from_longest (buf
, type
, num
);
3360 error (_("Unexpected type (%d) encountered for integer constant."),
3366 /* Pack NUM into BUF using a target format of TYPE. */
3369 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3372 enum bfd_endian byte_order
;
3374 type
= check_typedef (type
);
3375 len
= TYPE_LENGTH (type
);
3376 byte_order
= type_byte_order (type
);
3378 switch (type
->code ())
3381 case TYPE_CODE_CHAR
:
3382 case TYPE_CODE_ENUM
:
3383 case TYPE_CODE_FLAGS
:
3384 case TYPE_CODE_BOOL
:
3385 case TYPE_CODE_RANGE
:
3386 case TYPE_CODE_MEMBERPTR
:
3387 store_unsigned_integer (buf
, len
, byte_order
, num
);
3391 case TYPE_CODE_RVALUE_REF
:
3393 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3397 case TYPE_CODE_DECFLOAT
:
3398 target_float_from_ulongest (buf
, type
, num
);
3402 error (_("Unexpected type (%d) encountered "
3403 "for unsigned integer constant."),
3409 /* Convert C numbers into newly allocated values. */
3412 value_from_longest (struct type
*type
, LONGEST num
)
3414 struct value
*val
= allocate_value (type
);
3416 pack_long (value_contents_raw (val
), type
, num
);
3421 /* Convert C unsigned numbers into newly allocated values. */
3424 value_from_ulongest (struct type
*type
, ULONGEST num
)
3426 struct value
*val
= allocate_value (type
);
3428 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3434 /* Create a value representing a pointer of type TYPE to the address
3438 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3440 struct value
*val
= allocate_value (type
);
3442 store_typed_address (value_contents_raw (val
),
3443 check_typedef (type
), addr
);
3447 /* Create and return a value object of TYPE containing the value D. The
3448 TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
3449 it is converted to target format. */
3452 value_from_host_double (struct type
*type
, double d
)
3454 struct value
*value
= allocate_value (type
);
3455 gdb_assert (type
->code () == TYPE_CODE_FLT
);
3456 target_float_from_host_double (value_contents_raw (value
),
3457 value_type (value
), d
);
3461 /* Create a value of type TYPE whose contents come from VALADDR, if it
3462 is non-null, and whose memory address (in the inferior) is
3463 ADDRESS. The type of the created value may differ from the passed
3464 type TYPE. Make sure to retrieve values new type after this call.
3465 Note that TYPE is not passed through resolve_dynamic_type; this is
3466 a special API intended for use only by Ada. */
3469 value_from_contents_and_address_unresolved (struct type
*type
,
3470 const gdb_byte
*valaddr
,
3475 if (valaddr
== NULL
)
3476 v
= allocate_value_lazy (type
);
3478 v
= value_from_contents (type
, valaddr
);
3479 VALUE_LVAL (v
) = lval_memory
;
3480 set_value_address (v
, address
);
3484 /* Create a value of type TYPE whose contents come from VALADDR, if it
3485 is non-null, and whose memory address (in the inferior) is
3486 ADDRESS. The type of the created value may differ from the passed
3487 type TYPE. Make sure to retrieve values new type after this call. */
3490 value_from_contents_and_address (struct type
*type
,
3491 const gdb_byte
*valaddr
,
3494 gdb::array_view
<const gdb_byte
> view
;
3495 if (valaddr
!= nullptr)
3496 view
= gdb::make_array_view (valaddr
, TYPE_LENGTH (type
));
3497 struct type
*resolved_type
= resolve_dynamic_type (type
, view
, address
);
3498 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3501 if (valaddr
== NULL
)
3502 v
= allocate_value_lazy (resolved_type
);
3504 v
= value_from_contents (resolved_type
, valaddr
);
3505 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3506 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3507 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3508 VALUE_LVAL (v
) = lval_memory
;
3509 set_value_address (v
, address
);
3513 /* Create a value of type TYPE holding the contents CONTENTS.
3514 The new value is `not_lval'. */
3517 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3519 struct value
*result
;
3521 result
= allocate_value (type
);
3522 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3526 /* Extract a value from the history file. Input will be of the form
3527 $digits or $$digits. See block comment above 'write_dollar_variable'
3531 value_from_history_ref (const char *h
, const char **endp
)
3543 /* Find length of numeral string. */
3544 for (; isdigit (h
[len
]); len
++)
3547 /* Make sure numeral string is not part of an identifier. */
3548 if (h
[len
] == '_' || isalpha (h
[len
]))
3551 /* Now collect the index value. */
3556 /* For some bizarre reason, "$$" is equivalent to "$$1",
3557 rather than to "$$0" as it ought to be! */
3565 index
= -strtol (&h
[2], &local_end
, 10);
3573 /* "$" is equivalent to "$0". */
3581 index
= strtol (&h
[1], &local_end
, 10);
3586 return access_value_history (index
);
3589 /* Get the component value (offset by OFFSET bytes) of a struct or
3590 union WHOLE. Component's type is TYPE. */
3593 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3597 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3598 v
= allocate_value_lazy (type
);
3601 v
= allocate_value (type
);
3602 value_contents_copy (v
, value_embedded_offset (v
),
3603 whole
, value_embedded_offset (whole
) + offset
,
3604 type_length_units (type
));
3606 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3607 set_value_component_location (v
, whole
);
3613 coerce_ref_if_computed (const struct value
*arg
)
3615 const struct lval_funcs
*funcs
;
3617 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3620 if (value_lval_const (arg
) != lval_computed
)
3623 funcs
= value_computed_funcs (arg
);
3624 if (funcs
->coerce_ref
== NULL
)
3627 return funcs
->coerce_ref (arg
);
3630 /* Look at value.h for description. */
3633 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3634 const struct type
*original_type
,
3635 struct value
*original_value
,
3636 CORE_ADDR original_value_address
)
3638 gdb_assert (original_type
->code () == TYPE_CODE_PTR
3639 || TYPE_IS_REFERENCE (original_type
));
3641 struct type
*original_target_type
= TYPE_TARGET_TYPE (original_type
);
3642 gdb::array_view
<const gdb_byte
> view
;
3643 struct type
*resolved_original_target_type
3644 = resolve_dynamic_type (original_target_type
, view
,
3645 original_value_address
);
3647 /* Re-adjust type. */
3648 deprecated_set_value_type (value
, resolved_original_target_type
);
3650 /* Add embedding info. */
3651 set_value_enclosing_type (value
, enc_type
);
3652 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3654 /* We may be pointing to an object of some derived type. */
3655 return value_full_object (value
, NULL
, 0, 0, 0);
3659 coerce_ref (struct value
*arg
)
3661 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3662 struct value
*retval
;
3663 struct type
*enc_type
;
3665 retval
= coerce_ref_if_computed (arg
);
3669 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3672 enc_type
= check_typedef (value_enclosing_type (arg
));
3673 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3675 CORE_ADDR addr
= unpack_pointer (value_type (arg
), value_contents (arg
));
3676 retval
= value_at_lazy (enc_type
, addr
);
3677 enc_type
= value_type (retval
);
3678 return readjust_indirect_value_type (retval
, enc_type
, value_type_arg_tmp
,
3683 coerce_array (struct value
*arg
)
3687 arg
= coerce_ref (arg
);
3688 type
= check_typedef (value_type (arg
));
3690 switch (type
->code ())
3692 case TYPE_CODE_ARRAY
:
3693 if (!type
->is_vector () && current_language
->c_style_arrays_p ())
3694 arg
= value_coerce_array (arg
);
3696 case TYPE_CODE_FUNC
:
3697 arg
= value_coerce_function (arg
);
3704 /* Return the return value convention that will be used for the
3707 enum return_value_convention
3708 struct_return_convention (struct gdbarch
*gdbarch
,
3709 struct value
*function
, struct type
*value_type
)
3711 enum type_code code
= value_type
->code ();
3713 if (code
== TYPE_CODE_ERROR
)
3714 error (_("Function return type unknown."));
3716 /* Probe the architecture for the return-value convention. */
3717 return gdbarch_return_value (gdbarch
, function
, value_type
,
3721 /* Return true if the function returning the specified type is using
3722 the convention of returning structures in memory (passing in the
3723 address as a hidden first parameter). */
3726 using_struct_return (struct gdbarch
*gdbarch
,
3727 struct value
*function
, struct type
*value_type
)
3729 if (value_type
->code () == TYPE_CODE_VOID
)
3730 /* A void return value is never in memory. See also corresponding
3731 code in "print_return_value". */
3734 return (struct_return_convention (gdbarch
, function
, value_type
)
3735 != RETURN_VALUE_REGISTER_CONVENTION
);
3738 /* Set the initialized field in a value struct. */
3741 set_value_initialized (struct value
*val
, int status
)
3743 val
->initialized
= status
;
3746 /* Return the initialized field in a value struct. */
3749 value_initialized (const struct value
*val
)
3751 return val
->initialized
;
3754 /* Helper for value_fetch_lazy when the value is a bitfield. */
3757 value_fetch_lazy_bitfield (struct value
*val
)
3759 gdb_assert (value_bitsize (val
) != 0);
3761 /* To read a lazy bitfield, read the entire enclosing value. This
3762 prevents reading the same block of (possibly volatile) memory once
3763 per bitfield. It would be even better to read only the containing
3764 word, but we have no way to record that just specific bits of a
3765 value have been fetched. */
3766 struct value
*parent
= value_parent (val
);
3768 if (value_lazy (parent
))
3769 value_fetch_lazy (parent
);
3771 unpack_value_bitfield (val
, value_bitpos (val
), value_bitsize (val
),
3772 value_contents_for_printing (parent
),
3773 value_offset (val
), parent
);
3776 /* Helper for value_fetch_lazy when the value is in memory. */
3779 value_fetch_lazy_memory (struct value
*val
)
3781 gdb_assert (VALUE_LVAL (val
) == lval_memory
);
3783 CORE_ADDR addr
= value_address (val
);
3784 struct type
*type
= check_typedef (value_enclosing_type (val
));
3786 if (TYPE_LENGTH (type
))
3787 read_value_memory (val
, 0, value_stack (val
),
3788 addr
, value_contents_all_raw (val
),
3789 type_length_units (type
));
3792 /* Helper for value_fetch_lazy when the value is in a register. */
3795 value_fetch_lazy_register (struct value
*val
)
3797 struct frame_info
*next_frame
;
3799 struct type
*type
= check_typedef (value_type (val
));
3800 struct value
*new_val
= val
, *mark
= value_mark ();
3802 /* Offsets are not supported here; lazy register values must
3803 refer to the entire register. */
3804 gdb_assert (value_offset (val
) == 0);
3806 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3808 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3810 next_frame
= frame_find_by_id (next_frame_id
);
3811 regnum
= VALUE_REGNUM (new_val
);
3813 gdb_assert (next_frame
!= NULL
);
3815 /* Convertible register routines are used for multi-register
3816 values and for interpretation in different types
3817 (e.g. float or int from a double register). Lazy
3818 register values should have the register's natural type,
3819 so they do not apply. */
3820 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3823 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3824 Since a "->next" operation was performed when setting
3825 this field, we do not need to perform a "next" operation
3826 again when unwinding the register. That's why
3827 frame_unwind_register_value() is called here instead of
3828 get_frame_register_value(). */
3829 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3831 /* If we get another lazy lval_register value, it means the
3832 register is found by reading it from NEXT_FRAME's next frame.
3833 frame_unwind_register_value should never return a value with
3834 the frame id pointing to NEXT_FRAME. If it does, it means we
3835 either have two consecutive frames with the same frame id
3836 in the frame chain, or some code is trying to unwind
3837 behind get_prev_frame's back (e.g., a frame unwind
3838 sniffer trying to unwind), bypassing its validations. In
3839 any case, it should always be an internal error to end up
3840 in this situation. */
3841 if (VALUE_LVAL (new_val
) == lval_register
3842 && value_lazy (new_val
)
3843 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3844 internal_error (__FILE__
, __LINE__
,
3845 _("infinite loop while fetching a register"));
3848 /* If it's still lazy (for instance, a saved register on the
3849 stack), fetch it. */
3850 if (value_lazy (new_val
))
3851 value_fetch_lazy (new_val
);
3853 /* Copy the contents and the unavailability/optimized-out
3854 meta-data from NEW_VAL to VAL. */
3855 set_value_lazy (val
, 0);
3856 value_contents_copy (val
, value_embedded_offset (val
),
3857 new_val
, value_embedded_offset (new_val
),
3858 type_length_units (type
));
3862 struct gdbarch
*gdbarch
;
3863 struct frame_info
*frame
;
3864 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3865 so that the frame level will be shown correctly. */
3866 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3867 regnum
= VALUE_REGNUM (val
);
3868 gdbarch
= get_frame_arch (frame
);
3870 fprintf_unfiltered (gdb_stdlog
,
3871 "{ value_fetch_lazy "
3872 "(frame=%d,regnum=%d(%s),...) ",
3873 frame_relative_level (frame
), regnum
,
3874 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3876 fprintf_unfiltered (gdb_stdlog
, "->");
3877 if (value_optimized_out (new_val
))
3879 fprintf_unfiltered (gdb_stdlog
, " ");
3880 val_print_optimized_out (new_val
, gdb_stdlog
);
3885 const gdb_byte
*buf
= value_contents (new_val
);
3887 if (VALUE_LVAL (new_val
) == lval_register
)
3888 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3889 VALUE_REGNUM (new_val
));
3890 else if (VALUE_LVAL (new_val
) == lval_memory
)
3891 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3893 value_address (new_val
)));
3895 fprintf_unfiltered (gdb_stdlog
, " computed");
3897 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3898 fprintf_unfiltered (gdb_stdlog
, "[");
3899 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3900 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3901 fprintf_unfiltered (gdb_stdlog
, "]");
3904 fprintf_unfiltered (gdb_stdlog
, " }\n");
3907 /* Dispose of the intermediate values. This prevents
3908 watchpoints from trying to watch the saved frame pointer. */
3909 value_free_to_mark (mark
);
3912 /* Load the actual content of a lazy value. Fetch the data from the
3913 user's process and clear the lazy flag to indicate that the data in
3914 the buffer is valid.
3916 If the value is zero-length, we avoid calling read_memory, which
3917 would abort. We mark the value as fetched anyway -- all 0 bytes of
3921 value_fetch_lazy (struct value
*val
)
3923 gdb_assert (value_lazy (val
));
3924 allocate_value_contents (val
);
3925 /* A value is either lazy, or fully fetched. The
3926 availability/validity is only established as we try to fetch a
3928 gdb_assert (val
->optimized_out
.empty ());
3929 gdb_assert (val
->unavailable
.empty ());
3930 if (value_bitsize (val
))
3931 value_fetch_lazy_bitfield (val
);
3932 else if (VALUE_LVAL (val
) == lval_memory
)
3933 value_fetch_lazy_memory (val
);
3934 else if (VALUE_LVAL (val
) == lval_register
)
3935 value_fetch_lazy_register (val
);
3936 else if (VALUE_LVAL (val
) == lval_computed
3937 && value_computed_funcs (val
)->read
!= NULL
)
3938 value_computed_funcs (val
)->read (val
);
3940 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3942 set_value_lazy (val
, 0);
3945 /* Implementation of the convenience function $_isvoid. */
3947 static struct value
*
3948 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3949 const struct language_defn
*language
,
3950 void *cookie
, int argc
, struct value
**argv
)
3955 error (_("You must provide one argument for $_isvoid."));
3957 ret
= value_type (argv
[0])->code () == TYPE_CODE_VOID
;
3959 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3962 /* Implementation of the convenience function $_creal. Extracts the
3963 real part from a complex number. */
3965 static struct value
*
3966 creal_internal_fn (struct gdbarch
*gdbarch
,
3967 const struct language_defn
*language
,
3968 void *cookie
, int argc
, struct value
**argv
)
3971 error (_("You must provide one argument for $_creal."));
3973 value
*cval
= argv
[0];
3974 type
*ctype
= check_typedef (value_type (cval
));
3975 if (ctype
->code () != TYPE_CODE_COMPLEX
)
3976 error (_("expected a complex number"));
3977 return value_real_part (cval
);
3980 /* Implementation of the convenience function $_cimag. Extracts the
3981 imaginary part from a complex number. */
3983 static struct value
*
3984 cimag_internal_fn (struct gdbarch
*gdbarch
,
3985 const struct language_defn
*language
,
3986 void *cookie
, int argc
,
3987 struct value
**argv
)
3990 error (_("You must provide one argument for $_cimag."));
3992 value
*cval
= argv
[0];
3993 type
*ctype
= check_typedef (value_type (cval
));
3994 if (ctype
->code () != TYPE_CODE_COMPLEX
)
3995 error (_("expected a complex number"));
3996 return value_imaginary_part (cval
);
4003 /* Test the ranges_contain function. */
4006 test_ranges_contain ()
4008 std::vector
<range
> ranges
;
4014 ranges
.push_back (r
);
4019 ranges
.push_back (r
);
4022 SELF_CHECK (!ranges_contain (ranges
, 2, 5));
4024 SELF_CHECK (ranges_contain (ranges
, 9, 5));
4026 SELF_CHECK (ranges_contain (ranges
, 10, 2));
4028 SELF_CHECK (ranges_contain (ranges
, 10, 5));
4030 SELF_CHECK (ranges_contain (ranges
, 13, 6));
4032 SELF_CHECK (ranges_contain (ranges
, 14, 5));
4034 SELF_CHECK (!ranges_contain (ranges
, 15, 4));
4036 SELF_CHECK (!ranges_contain (ranges
, 16, 4));
4038 SELF_CHECK (ranges_contain (ranges
, 16, 6));
4040 SELF_CHECK (ranges_contain (ranges
, 21, 1));
4042 SELF_CHECK (ranges_contain (ranges
, 21, 5));
4044 SELF_CHECK (!ranges_contain (ranges
, 26, 3));
4047 /* Check that RANGES contains the same ranges as EXPECTED. */
4050 check_ranges_vector (gdb::array_view
<const range
> ranges
,
4051 gdb::array_view
<const range
> expected
)
4053 return ranges
== expected
;
4056 /* Test the insert_into_bit_range_vector function. */
4059 test_insert_into_bit_range_vector ()
4061 std::vector
<range
> ranges
;
4065 insert_into_bit_range_vector (&ranges
, 10, 5);
4066 static const range expected
[] = {
4069 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4074 insert_into_bit_range_vector (&ranges
, 11, 4);
4075 static const range expected
= {10, 5};
4076 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4079 /* [10, 14] [20, 24] */
4081 insert_into_bit_range_vector (&ranges
, 20, 5);
4082 static const range expected
[] = {
4086 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4089 /* [10, 14] [17, 24] */
4091 insert_into_bit_range_vector (&ranges
, 17, 5);
4092 static const range expected
[] = {
4096 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4099 /* [2, 8] [10, 14] [17, 24] */
4101 insert_into_bit_range_vector (&ranges
, 2, 7);
4102 static const range expected
[] = {
4107 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4110 /* [2, 14] [17, 24] */
4112 insert_into_bit_range_vector (&ranges
, 9, 1);
4113 static const range expected
[] = {
4117 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4120 /* [2, 14] [17, 24] */
4122 insert_into_bit_range_vector (&ranges
, 9, 1);
4123 static const range expected
[] = {
4127 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4132 insert_into_bit_range_vector (&ranges
, 4, 30);
4133 static const range expected
= {2, 32};
4134 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4138 } /* namespace selftests */
4139 #endif /* GDB_SELF_TEST */
4141 void _initialize_values ();
4143 _initialize_values ()
4145 add_cmd ("convenience", no_class
, show_convenience
, _("\
4146 Debugger convenience (\"$foo\") variables and functions.\n\
4147 Convenience variables are created when you assign them values;\n\
4148 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4150 A few convenience variables are given values automatically:\n\
4151 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4152 \"$__\" holds the contents of the last address examined with \"x\"."
4155 Convenience functions are defined via the Python API."
4158 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4160 add_cmd ("values", no_set_class
, show_values
, _("\
4161 Elements of value history around item number IDX (or last ten)."),
4164 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4165 Initialize a convenience variable if necessary.\n\
4166 init-if-undefined VARIABLE = EXPRESSION\n\
4167 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4168 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4169 VARIABLE is already initialized."));
4171 add_prefix_cmd ("function", no_class
, function_command
, _("\
4172 Placeholder command for showing help on convenience functions."),
4173 &functionlist
, "function ", 0, &cmdlist
);
4175 add_internal_function ("_isvoid", _("\
4176 Check whether an expression is void.\n\
4177 Usage: $_isvoid (expression)\n\
4178 Return 1 if the expression is void, zero otherwise."),
4179 isvoid_internal_fn
, NULL
);
4181 add_internal_function ("_creal", _("\
4182 Extract the real part of a complex number.\n\
4183 Usage: $_creal (expression)\n\
4184 Return the real part of a complex number, the type depends on the\n\
4185 type of a complex number."),
4186 creal_internal_fn
, NULL
);
4188 add_internal_function ("_cimag", _("\
4189 Extract the imaginary part of a complex number.\n\
4190 Usage: $_cimag (expression)\n\
4191 Return the imaginary part of a complex number, the type depends on the\n\
4192 type of a complex number."),
4193 cimag_internal_fn
, NULL
);
4195 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4196 class_support
, &max_value_size
, _("\
4197 Set maximum sized value gdb will load from the inferior."), _("\
4198 Show maximum sized value gdb will load from the inferior."), _("\
4199 Use this to control the maximum size, in bytes, of a value that gdb\n\
4200 will load from the inferior. Setting this value to 'unlimited'\n\
4201 disables checking.\n\
4202 Setting this does not invalidate already allocated values, it only\n\
4203 prevents future values, larger than this size, from being allocated."),
4205 show_max_value_size
,
4206 &setlist
, &showlist
);
4208 selftests::register_test ("ranges_contain", selftests::test_ranges_contain
);
4209 selftests::register_test ("insert_into_bit_range_vector",
4210 selftests::test_insert_into_bit_range_vector
);
4219 all_values
.clear ();