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 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1045 /* FIXME-type-allocation: need a way to free this type when we are
1047 struct type
*array_type
1048 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1050 return allocate_value (array_type
);
1054 allocate_computed_value (struct type
*type
,
1055 const struct lval_funcs
*funcs
,
1058 struct value
*v
= allocate_value_lazy (type
);
1060 VALUE_LVAL (v
) = lval_computed
;
1061 v
->location
.computed
.funcs
= funcs
;
1062 v
->location
.computed
.closure
= closure
;
1067 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1070 allocate_optimized_out_value (struct type
*type
)
1072 struct value
*retval
= allocate_value_lazy (type
);
1074 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1075 set_value_lazy (retval
, 0);
1079 /* Accessor methods. */
1082 value_type (const struct value
*value
)
1087 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1093 value_offset (const struct value
*value
)
1095 return value
->offset
;
1098 set_value_offset (struct value
*value
, LONGEST offset
)
1100 value
->offset
= offset
;
1104 value_bitpos (const struct value
*value
)
1106 return value
->bitpos
;
1109 set_value_bitpos (struct value
*value
, LONGEST bit
)
1111 value
->bitpos
= bit
;
1115 value_bitsize (const struct value
*value
)
1117 return value
->bitsize
;
1120 set_value_bitsize (struct value
*value
, LONGEST bit
)
1122 value
->bitsize
= bit
;
1126 value_parent (const struct value
*value
)
1128 return value
->parent
.get ();
1134 set_value_parent (struct value
*value
, struct value
*parent
)
1136 value
->parent
= value_ref_ptr::new_reference (parent
);
1140 value_contents_raw (struct value
*value
)
1142 struct gdbarch
*arch
= get_value_arch (value
);
1143 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1145 allocate_value_contents (value
);
1146 return value
->contents
.get () + value
->embedded_offset
* unit_size
;
1150 value_contents_all_raw (struct value
*value
)
1152 allocate_value_contents (value
);
1153 return value
->contents
.get ();
1157 value_enclosing_type (const struct value
*value
)
1159 return value
->enclosing_type
;
1162 /* Look at value.h for description. */
1165 value_actual_type (struct value
*value
, int resolve_simple_types
,
1166 int *real_type_found
)
1168 struct value_print_options opts
;
1169 struct type
*result
;
1171 get_user_print_options (&opts
);
1173 if (real_type_found
)
1174 *real_type_found
= 0;
1175 result
= value_type (value
);
1176 if (opts
.objectprint
)
1178 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1179 fetch its rtti type. */
1180 if ((result
->code () == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1181 && (check_typedef (TYPE_TARGET_TYPE (result
))->code ()
1182 == TYPE_CODE_STRUCT
)
1183 && !value_optimized_out (value
))
1185 struct type
*real_type
;
1187 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1190 if (real_type_found
)
1191 *real_type_found
= 1;
1195 else if (resolve_simple_types
)
1197 if (real_type_found
)
1198 *real_type_found
= 1;
1199 result
= value_enclosing_type (value
);
1207 error_value_optimized_out (void)
1209 error (_("value has been optimized out"));
1213 require_not_optimized_out (const struct value
*value
)
1215 if (!value
->optimized_out
.empty ())
1217 if (value
->lval
== lval_register
)
1218 error (_("register has not been saved in frame"));
1220 error_value_optimized_out ();
1225 require_available (const struct value
*value
)
1227 if (!value
->unavailable
.empty ())
1228 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1232 value_contents_for_printing (struct value
*value
)
1235 value_fetch_lazy (value
);
1236 return value
->contents
.get ();
1240 value_contents_for_printing_const (const struct value
*value
)
1242 gdb_assert (!value
->lazy
);
1243 return value
->contents
.get ();
1247 value_contents_all (struct value
*value
)
1249 const gdb_byte
*result
= value_contents_for_printing (value
);
1250 require_not_optimized_out (value
);
1251 require_available (value
);
1255 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1256 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1259 ranges_copy_adjusted (std::vector
<range
> *dst_range
, int dst_bit_offset
,
1260 const std::vector
<range
> &src_range
, int src_bit_offset
,
1263 for (const range
&r
: src_range
)
1267 l
= std::max (r
.offset
, (LONGEST
) src_bit_offset
);
1268 h
= std::min (r
.offset
+ r
.length
,
1269 (LONGEST
) src_bit_offset
+ bit_length
);
1272 insert_into_bit_range_vector (dst_range
,
1273 dst_bit_offset
+ (l
- src_bit_offset
),
1278 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1279 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1282 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1283 const struct value
*src
, int src_bit_offset
,
1286 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1287 src
->unavailable
, src_bit_offset
,
1289 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1290 src
->optimized_out
, src_bit_offset
,
1294 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1295 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1296 contents, starting at DST_OFFSET. If unavailable contents are
1297 being copied from SRC, the corresponding DST contents are marked
1298 unavailable accordingly. Neither DST nor SRC may be lazy
1301 It is assumed the contents of DST in the [DST_OFFSET,
1302 DST_OFFSET+LENGTH) range are wholly available. */
1305 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1306 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1308 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1309 struct gdbarch
*arch
= get_value_arch (src
);
1310 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1312 /* A lazy DST would make that this copy operation useless, since as
1313 soon as DST's contents were un-lazied (by a later value_contents
1314 call, say), the contents would be overwritten. A lazy SRC would
1315 mean we'd be copying garbage. */
1316 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1318 /* The overwritten DST range gets unavailability ORed in, not
1319 replaced. Make sure to remember to implement replacing if it
1320 turns out actually necessary. */
1321 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1322 gdb_assert (!value_bits_any_optimized_out (dst
,
1323 TARGET_CHAR_BIT
* dst_offset
,
1324 TARGET_CHAR_BIT
* length
));
1326 /* Copy the data. */
1327 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1328 value_contents_all_raw (src
) + src_offset
* unit_size
,
1329 length
* unit_size
);
1331 /* Copy the meta-data, adjusted. */
1332 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1333 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1334 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1336 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1337 src
, src_bit_offset
,
1341 /* Copy LENGTH bytes of SRC value's (all) contents
1342 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1343 (all) contents, starting at DST_OFFSET. If unavailable contents
1344 are being copied from SRC, the corresponding DST contents are
1345 marked unavailable accordingly. DST must not be lazy. If SRC is
1346 lazy, it will be fetched now.
1348 It is assumed the contents of DST in the [DST_OFFSET,
1349 DST_OFFSET+LENGTH) range are wholly available. */
1352 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1353 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1356 value_fetch_lazy (src
);
1358 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1362 value_lazy (const struct value
*value
)
1368 set_value_lazy (struct value
*value
, int val
)
1374 value_stack (const struct value
*value
)
1376 return value
->stack
;
1380 set_value_stack (struct value
*value
, int val
)
1386 value_contents (struct value
*value
)
1388 const gdb_byte
*result
= value_contents_writeable (value
);
1389 require_not_optimized_out (value
);
1390 require_available (value
);
1395 value_contents_writeable (struct value
*value
)
1398 value_fetch_lazy (value
);
1399 return value_contents_raw (value
);
1403 value_optimized_out (struct value
*value
)
1405 /* We can only know if a value is optimized out once we have tried to
1407 if (value
->optimized_out
.empty () && value
->lazy
)
1411 value_fetch_lazy (value
);
1413 catch (const gdb_exception_error
&ex
)
1418 case OPTIMIZED_OUT_ERROR
:
1419 case NOT_AVAILABLE_ERROR
:
1420 /* These can normally happen when we try to access an
1421 optimized out or unavailable register, either in a
1422 physical register or spilled to memory. */
1430 return !value
->optimized_out
.empty ();
1433 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1434 the following LENGTH bytes. */
1437 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1439 mark_value_bits_optimized_out (value
,
1440 offset
* TARGET_CHAR_BIT
,
1441 length
* TARGET_CHAR_BIT
);
1447 mark_value_bits_optimized_out (struct value
*value
,
1448 LONGEST offset
, LONGEST length
)
1450 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1454 value_bits_synthetic_pointer (const struct value
*value
,
1455 LONGEST offset
, LONGEST length
)
1457 if (value
->lval
!= lval_computed
1458 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1460 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1466 value_embedded_offset (const struct value
*value
)
1468 return value
->embedded_offset
;
1472 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1474 value
->embedded_offset
= val
;
1478 value_pointed_to_offset (const struct value
*value
)
1480 return value
->pointed_to_offset
;
1484 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1486 value
->pointed_to_offset
= val
;
1489 const struct lval_funcs
*
1490 value_computed_funcs (const struct value
*v
)
1492 gdb_assert (value_lval_const (v
) == lval_computed
);
1494 return v
->location
.computed
.funcs
;
1498 value_computed_closure (const struct value
*v
)
1500 gdb_assert (v
->lval
== lval_computed
);
1502 return v
->location
.computed
.closure
;
1506 deprecated_value_lval_hack (struct value
*value
)
1508 return &value
->lval
;
1512 value_lval_const (const struct value
*value
)
1518 value_address (const struct value
*value
)
1520 if (value
->lval
!= lval_memory
)
1522 if (value
->parent
!= NULL
)
1523 return value_address (value
->parent
.get ()) + value
->offset
;
1524 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1526 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1527 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1530 return value
->location
.address
+ value
->offset
;
1534 value_raw_address (const struct value
*value
)
1536 if (value
->lval
!= lval_memory
)
1538 return value
->location
.address
;
1542 set_value_address (struct value
*value
, CORE_ADDR addr
)
1544 gdb_assert (value
->lval
== lval_memory
);
1545 value
->location
.address
= addr
;
1548 struct internalvar
**
1549 deprecated_value_internalvar_hack (struct value
*value
)
1551 return &value
->location
.internalvar
;
1555 deprecated_value_next_frame_id_hack (struct value
*value
)
1557 gdb_assert (value
->lval
== lval_register
);
1558 return &value
->location
.reg
.next_frame_id
;
1562 deprecated_value_regnum_hack (struct value
*value
)
1564 gdb_assert (value
->lval
== lval_register
);
1565 return &value
->location
.reg
.regnum
;
1569 deprecated_value_modifiable (const struct value
*value
)
1571 return value
->modifiable
;
1574 /* Return a mark in the value chain. All values allocated after the
1575 mark is obtained (except for those released) are subject to being freed
1576 if a subsequent value_free_to_mark is passed the mark. */
1580 if (all_values
.empty ())
1582 return all_values
.back ().get ();
1588 value_incref (struct value
*val
)
1590 val
->reference_count
++;
1593 /* Release a reference to VAL, which was acquired with value_incref.
1594 This function is also called to deallocate values from the value
1598 value_decref (struct value
*val
)
1602 gdb_assert (val
->reference_count
> 0);
1603 val
->reference_count
--;
1604 if (val
->reference_count
== 0)
1609 /* Free all values allocated since MARK was obtained by value_mark
1610 (except for those released). */
1612 value_free_to_mark (const struct value
*mark
)
1614 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1615 if (iter
== all_values
.end ())
1616 all_values
.clear ();
1618 all_values
.erase (iter
+ 1, all_values
.end ());
1621 /* Remove VAL from the chain all_values
1622 so it will not be freed automatically. */
1625 release_value (struct value
*val
)
1628 return value_ref_ptr ();
1630 std::vector
<value_ref_ptr
>::reverse_iterator iter
;
1631 for (iter
= all_values
.rbegin (); iter
!= all_values
.rend (); ++iter
)
1635 value_ref_ptr result
= *iter
;
1636 all_values
.erase (iter
.base () - 1);
1641 /* We must always return an owned reference. Normally this happens
1642 because we transfer the reference from the value chain, but in
1643 this case the value was not on the chain. */
1644 return value_ref_ptr::new_reference (val
);
1649 std::vector
<value_ref_ptr
>
1650 value_release_to_mark (const struct value
*mark
)
1652 std::vector
<value_ref_ptr
> result
;
1654 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1655 if (iter
== all_values
.end ())
1656 std::swap (result
, all_values
);
1659 std::move (iter
+ 1, all_values
.end (), std::back_inserter (result
));
1660 all_values
.erase (iter
+ 1, all_values
.end ());
1662 std::reverse (result
.begin (), result
.end ());
1666 /* Return a copy of the value ARG.
1667 It contains the same contents, for same memory address,
1668 but it's a different block of storage. */
1671 value_copy (struct value
*arg
)
1673 struct type
*encl_type
= value_enclosing_type (arg
);
1676 if (value_lazy (arg
))
1677 val
= allocate_value_lazy (encl_type
);
1679 val
= allocate_value (encl_type
);
1680 val
->type
= arg
->type
;
1681 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1682 val
->location
= arg
->location
;
1683 val
->offset
= arg
->offset
;
1684 val
->bitpos
= arg
->bitpos
;
1685 val
->bitsize
= arg
->bitsize
;
1686 val
->lazy
= arg
->lazy
;
1687 val
->embedded_offset
= value_embedded_offset (arg
);
1688 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1689 val
->modifiable
= arg
->modifiable
;
1690 if (!value_lazy (val
))
1692 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1693 TYPE_LENGTH (value_enclosing_type (arg
)));
1696 val
->unavailable
= arg
->unavailable
;
1697 val
->optimized_out
= arg
->optimized_out
;
1698 val
->parent
= arg
->parent
;
1699 if (VALUE_LVAL (val
) == lval_computed
)
1701 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1703 if (funcs
->copy_closure
)
1704 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1709 /* Return a "const" and/or "volatile" qualified version of the value V.
1710 If CNST is true, then the returned value will be qualified with
1712 if VOLTL is true, then the returned value will be qualified with
1716 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1718 struct type
*val_type
= value_type (v
);
1719 struct type
*enclosing_type
= value_enclosing_type (v
);
1720 struct value
*cv_val
= value_copy (v
);
1722 deprecated_set_value_type (cv_val
,
1723 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1724 set_value_enclosing_type (cv_val
,
1725 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1730 /* Return a version of ARG that is non-lvalue. */
1733 value_non_lval (struct value
*arg
)
1735 if (VALUE_LVAL (arg
) != not_lval
)
1737 struct type
*enc_type
= value_enclosing_type (arg
);
1738 struct value
*val
= allocate_value (enc_type
);
1740 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1741 TYPE_LENGTH (enc_type
));
1742 val
->type
= arg
->type
;
1743 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1744 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1750 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1753 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1755 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1757 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1758 v
->lval
= lval_memory
;
1759 v
->location
.address
= addr
;
1763 set_value_component_location (struct value
*component
,
1764 const struct value
*whole
)
1768 gdb_assert (whole
->lval
!= lval_xcallable
);
1770 if (whole
->lval
== lval_internalvar
)
1771 VALUE_LVAL (component
) = lval_internalvar_component
;
1773 VALUE_LVAL (component
) = whole
->lval
;
1775 component
->location
= whole
->location
;
1776 if (whole
->lval
== lval_computed
)
1778 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1780 if (funcs
->copy_closure
)
1781 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1784 /* If type has a dynamic resolved location property
1785 update it's value address. */
1786 type
= value_type (whole
);
1787 if (NULL
!= TYPE_DATA_LOCATION (type
)
1788 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1789 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1792 /* Access to the value history. */
1794 /* Record a new value in the value history.
1795 Returns the absolute history index of the entry. */
1798 record_latest_value (struct value
*val
)
1800 /* We don't want this value to have anything to do with the inferior anymore.
1801 In particular, "set $1 = 50" should not affect the variable from which
1802 the value was taken, and fast watchpoints should be able to assume that
1803 a value on the value history never changes. */
1804 if (value_lazy (val
))
1805 value_fetch_lazy (val
);
1806 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1807 from. This is a bit dubious, because then *&$1 does not just return $1
1808 but the current contents of that location. c'est la vie... */
1809 val
->modifiable
= 0;
1811 value_history
.push_back (release_value (val
));
1813 return value_history
.size ();
1816 /* Return a copy of the value in the history with sequence number NUM. */
1819 access_value_history (int num
)
1824 absnum
+= value_history
.size ();
1829 error (_("The history is empty."));
1831 error (_("There is only one value in the history."));
1833 error (_("History does not go back to $$%d."), -num
);
1835 if (absnum
> value_history
.size ())
1836 error (_("History has not yet reached $%d."), absnum
);
1840 return value_copy (value_history
[absnum
].get ());
1844 show_values (const char *num_exp
, int from_tty
)
1852 /* "show values +" should print from the stored position.
1853 "show values <exp>" should print around value number <exp>. */
1854 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1855 num
= parse_and_eval_long (num_exp
) - 5;
1859 /* "show values" means print the last 10 values. */
1860 num
= value_history
.size () - 9;
1866 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1868 struct value_print_options opts
;
1870 val
= access_value_history (i
);
1871 printf_filtered (("$%d = "), i
);
1872 get_user_print_options (&opts
);
1873 value_print (val
, gdb_stdout
, &opts
);
1874 printf_filtered (("\n"));
1877 /* The next "show values +" should start after what we just printed. */
1880 /* Hitting just return after this command should do the same thing as
1881 "show values +". If num_exp is null, this is unnecessary, since
1882 "show values +" is not useful after "show values". */
1883 if (from_tty
&& num_exp
)
1884 set_repeat_arguments ("+");
1887 enum internalvar_kind
1889 /* The internal variable is empty. */
1892 /* The value of the internal variable is provided directly as
1893 a GDB value object. */
1896 /* A fresh value is computed via a call-back routine on every
1897 access to the internal variable. */
1898 INTERNALVAR_MAKE_VALUE
,
1900 /* The internal variable holds a GDB internal convenience function. */
1901 INTERNALVAR_FUNCTION
,
1903 /* The variable holds an integer value. */
1904 INTERNALVAR_INTEGER
,
1906 /* The variable holds a GDB-provided string. */
1910 union internalvar_data
1912 /* A value object used with INTERNALVAR_VALUE. */
1913 struct value
*value
;
1915 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1918 /* The functions to call. */
1919 const struct internalvar_funcs
*functions
;
1921 /* The function's user-data. */
1925 /* The internal function used with INTERNALVAR_FUNCTION. */
1928 struct internal_function
*function
;
1929 /* True if this is the canonical name for the function. */
1933 /* An integer value used with INTERNALVAR_INTEGER. */
1936 /* If type is non-NULL, it will be used as the type to generate
1937 a value for this internal variable. If type is NULL, a default
1938 integer type for the architecture is used. */
1943 /* A string value used with INTERNALVAR_STRING. */
1947 /* Internal variables. These are variables within the debugger
1948 that hold values assigned by debugger commands.
1949 The user refers to them with a '$' prefix
1950 that does not appear in the variable names stored internally. */
1954 struct internalvar
*next
;
1957 /* We support various different kinds of content of an internal variable.
1958 enum internalvar_kind specifies the kind, and union internalvar_data
1959 provides the data associated with this particular kind. */
1961 enum internalvar_kind kind
;
1963 union internalvar_data u
;
1966 static struct internalvar
*internalvars
;
1968 /* If the variable does not already exist create it and give it the
1969 value given. If no value is given then the default is zero. */
1971 init_if_undefined_command (const char* args
, int from_tty
)
1973 struct internalvar
* intvar
;
1975 /* Parse the expression - this is taken from set_command(). */
1976 expression_up expr
= parse_expression (args
);
1978 /* Validate the expression.
1979 Was the expression an assignment?
1980 Or even an expression at all? */
1981 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1982 error (_("Init-if-undefined requires an assignment expression."));
1984 /* Extract the variable from the parsed expression.
1985 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1986 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1987 error (_("The first parameter to init-if-undefined "
1988 "should be a GDB variable."));
1989 intvar
= expr
->elts
[2].internalvar
;
1991 /* Only evaluate the expression if the lvalue is void.
1992 This may still fail if the expression is invalid. */
1993 if (intvar
->kind
== INTERNALVAR_VOID
)
1994 evaluate_expression (expr
.get ());
1998 /* Look up an internal variable with name NAME. NAME should not
1999 normally include a dollar sign.
2001 If the specified internal variable does not exist,
2002 the return value is NULL. */
2004 struct internalvar
*
2005 lookup_only_internalvar (const char *name
)
2007 struct internalvar
*var
;
2009 for (var
= internalvars
; var
; var
= var
->next
)
2010 if (strcmp (var
->name
, name
) == 0)
2016 /* Complete NAME by comparing it to the names of internal
2020 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2022 struct internalvar
*var
;
2025 len
= strlen (name
);
2027 for (var
= internalvars
; var
; var
= var
->next
)
2028 if (strncmp (var
->name
, name
, len
) == 0)
2029 tracker
.add_completion (make_unique_xstrdup (var
->name
));
2032 /* Create an internal variable with name NAME and with a void value.
2033 NAME should not normally include a dollar sign. */
2035 struct internalvar
*
2036 create_internalvar (const char *name
)
2038 struct internalvar
*var
= XNEW (struct internalvar
);
2040 var
->name
= xstrdup (name
);
2041 var
->kind
= INTERNALVAR_VOID
;
2042 var
->next
= internalvars
;
2047 /* Create an internal variable with name NAME and register FUN as the
2048 function that value_of_internalvar uses to create a value whenever
2049 this variable is referenced. NAME should not normally include a
2050 dollar sign. DATA is passed uninterpreted to FUN when it is
2051 called. CLEANUP, if not NULL, is called when the internal variable
2052 is destroyed. It is passed DATA as its only argument. */
2054 struct internalvar
*
2055 create_internalvar_type_lazy (const char *name
,
2056 const struct internalvar_funcs
*funcs
,
2059 struct internalvar
*var
= create_internalvar (name
);
2061 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2062 var
->u
.make_value
.functions
= funcs
;
2063 var
->u
.make_value
.data
= data
;
2067 /* See documentation in value.h. */
2070 compile_internalvar_to_ax (struct internalvar
*var
,
2071 struct agent_expr
*expr
,
2072 struct axs_value
*value
)
2074 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2075 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2078 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2079 var
->u
.make_value
.data
);
2083 /* Look up an internal variable with name NAME. NAME should not
2084 normally include a dollar sign.
2086 If the specified internal variable does not exist,
2087 one is created, with a void value. */
2089 struct internalvar
*
2090 lookup_internalvar (const char *name
)
2092 struct internalvar
*var
;
2094 var
= lookup_only_internalvar (name
);
2098 return create_internalvar (name
);
2101 /* Return current value of internal variable VAR. For variables that
2102 are not inherently typed, use a value type appropriate for GDBARCH. */
2105 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2108 struct trace_state_variable
*tsv
;
2110 /* If there is a trace state variable of the same name, assume that
2111 is what we really want to see. */
2112 tsv
= find_trace_state_variable (var
->name
);
2115 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2117 if (tsv
->value_known
)
2118 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2121 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2127 case INTERNALVAR_VOID
:
2128 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2131 case INTERNALVAR_FUNCTION
:
2132 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2135 case INTERNALVAR_INTEGER
:
2136 if (!var
->u
.integer
.type
)
2137 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2138 var
->u
.integer
.val
);
2140 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2143 case INTERNALVAR_STRING
:
2144 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2145 builtin_type (gdbarch
)->builtin_char
);
2148 case INTERNALVAR_VALUE
:
2149 val
= value_copy (var
->u
.value
);
2150 if (value_lazy (val
))
2151 value_fetch_lazy (val
);
2154 case INTERNALVAR_MAKE_VALUE
:
2155 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2156 var
->u
.make_value
.data
);
2160 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2163 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2164 on this value go back to affect the original internal variable.
2166 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2167 no underlying modifiable state in the internal variable.
2169 Likewise, if the variable's value is a computed lvalue, we want
2170 references to it to produce another computed lvalue, where
2171 references and assignments actually operate through the
2172 computed value's functions.
2174 This means that internal variables with computed values
2175 behave a little differently from other internal variables:
2176 assignments to them don't just replace the previous value
2177 altogether. At the moment, this seems like the behavior we
2180 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2181 && val
->lval
!= lval_computed
)
2183 VALUE_LVAL (val
) = lval_internalvar
;
2184 VALUE_INTERNALVAR (val
) = var
;
2191 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2193 if (var
->kind
== INTERNALVAR_INTEGER
)
2195 *result
= var
->u
.integer
.val
;
2199 if (var
->kind
== INTERNALVAR_VALUE
)
2201 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2203 if (type
->code () == TYPE_CODE_INT
)
2205 *result
= value_as_long (var
->u
.value
);
2214 get_internalvar_function (struct internalvar
*var
,
2215 struct internal_function
**result
)
2219 case INTERNALVAR_FUNCTION
:
2220 *result
= var
->u
.fn
.function
;
2229 set_internalvar_component (struct internalvar
*var
,
2230 LONGEST offset
, LONGEST bitpos
,
2231 LONGEST bitsize
, struct value
*newval
)
2234 struct gdbarch
*arch
;
2239 case INTERNALVAR_VALUE
:
2240 addr
= value_contents_writeable (var
->u
.value
);
2241 arch
= get_value_arch (var
->u
.value
);
2242 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2245 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2246 value_as_long (newval
), bitpos
, bitsize
);
2248 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2249 TYPE_LENGTH (value_type (newval
)));
2253 /* We can never get a component of any other kind. */
2254 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2259 set_internalvar (struct internalvar
*var
, struct value
*val
)
2261 enum internalvar_kind new_kind
;
2262 union internalvar_data new_data
= { 0 };
2264 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2265 error (_("Cannot overwrite convenience function %s"), var
->name
);
2267 /* Prepare new contents. */
2268 switch (check_typedef (value_type (val
))->code ())
2270 case TYPE_CODE_VOID
:
2271 new_kind
= INTERNALVAR_VOID
;
2274 case TYPE_CODE_INTERNAL_FUNCTION
:
2275 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2276 new_kind
= INTERNALVAR_FUNCTION
;
2277 get_internalvar_function (VALUE_INTERNALVAR (val
),
2278 &new_data
.fn
.function
);
2279 /* Copies created here are never canonical. */
2283 new_kind
= INTERNALVAR_VALUE
;
2284 struct value
*copy
= value_copy (val
);
2285 copy
->modifiable
= 1;
2287 /* Force the value to be fetched from the target now, to avoid problems
2288 later when this internalvar is referenced and the target is gone or
2290 if (value_lazy (copy
))
2291 value_fetch_lazy (copy
);
2293 /* Release the value from the value chain to prevent it from being
2294 deleted by free_all_values. From here on this function should not
2295 call error () until new_data is installed into the var->u to avoid
2297 new_data
.value
= release_value (copy
).release ();
2299 /* Internal variables which are created from values with a dynamic
2300 location don't need the location property of the origin anymore.
2301 The resolved dynamic location is used prior then any other address
2302 when accessing the value.
2303 If we keep it, we would still refer to the origin value.
2304 Remove the location property in case it exist. */
2305 value_type (new_data
.value
)->remove_dyn_prop (DYN_PROP_DATA_LOCATION
);
2310 /* Clean up old contents. */
2311 clear_internalvar (var
);
2314 var
->kind
= new_kind
;
2316 /* End code which must not call error(). */
2320 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2322 /* Clean up old contents. */
2323 clear_internalvar (var
);
2325 var
->kind
= INTERNALVAR_INTEGER
;
2326 var
->u
.integer
.type
= NULL
;
2327 var
->u
.integer
.val
= l
;
2331 set_internalvar_string (struct internalvar
*var
, const char *string
)
2333 /* Clean up old contents. */
2334 clear_internalvar (var
);
2336 var
->kind
= INTERNALVAR_STRING
;
2337 var
->u
.string
= xstrdup (string
);
2341 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2343 /* Clean up old contents. */
2344 clear_internalvar (var
);
2346 var
->kind
= INTERNALVAR_FUNCTION
;
2347 var
->u
.fn
.function
= f
;
2348 var
->u
.fn
.canonical
= 1;
2349 /* Variables installed here are always the canonical version. */
2353 clear_internalvar (struct internalvar
*var
)
2355 /* Clean up old contents. */
2358 case INTERNALVAR_VALUE
:
2359 value_decref (var
->u
.value
);
2362 case INTERNALVAR_STRING
:
2363 xfree (var
->u
.string
);
2366 case INTERNALVAR_MAKE_VALUE
:
2367 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2368 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2375 /* Reset to void kind. */
2376 var
->kind
= INTERNALVAR_VOID
;
2380 internalvar_name (const struct internalvar
*var
)
2385 static struct internal_function
*
2386 create_internal_function (const char *name
,
2387 internal_function_fn handler
, void *cookie
)
2389 struct internal_function
*ifn
= XNEW (struct internal_function
);
2391 ifn
->name
= xstrdup (name
);
2392 ifn
->handler
= handler
;
2393 ifn
->cookie
= cookie
;
2398 value_internal_function_name (struct value
*val
)
2400 struct internal_function
*ifn
;
2403 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2404 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2405 gdb_assert (result
);
2411 call_internal_function (struct gdbarch
*gdbarch
,
2412 const struct language_defn
*language
,
2413 struct value
*func
, int argc
, struct value
**argv
)
2415 struct internal_function
*ifn
;
2418 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2419 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2420 gdb_assert (result
);
2422 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2425 /* The 'function' command. This does nothing -- it is just a
2426 placeholder to let "help function NAME" work. This is also used as
2427 the implementation of the sub-command that is created when
2428 registering an internal function. */
2430 function_command (const char *command
, int from_tty
)
2435 /* Helper function that does the work for add_internal_function. */
2437 static struct cmd_list_element
*
2438 do_add_internal_function (const char *name
, const char *doc
,
2439 internal_function_fn handler
, void *cookie
)
2441 struct internal_function
*ifn
;
2442 struct internalvar
*var
= lookup_internalvar (name
);
2444 ifn
= create_internal_function (name
, handler
, cookie
);
2445 set_internalvar_function (var
, ifn
);
2447 return add_cmd (name
, no_class
, function_command
, doc
, &functionlist
);
2453 add_internal_function (const char *name
, const char *doc
,
2454 internal_function_fn handler
, void *cookie
)
2456 do_add_internal_function (name
, doc
, handler
, cookie
);
2462 add_internal_function (gdb::unique_xmalloc_ptr
<char> &&name
,
2463 gdb::unique_xmalloc_ptr
<char> &&doc
,
2464 internal_function_fn handler
, void *cookie
)
2466 struct cmd_list_element
*cmd
2467 = do_add_internal_function (name
.get (), doc
.get (), handler
, cookie
);
2469 cmd
->doc_allocated
= 1;
2471 cmd
->name_allocated
= 1;
2474 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2475 prevent cycles / duplicates. */
2478 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2479 htab_t copied_types
)
2481 if (TYPE_OBJFILE (value
->type
) == objfile
)
2482 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2484 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2485 value
->enclosing_type
= copy_type_recursive (objfile
,
2486 value
->enclosing_type
,
2490 /* Likewise for internal variable VAR. */
2493 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2494 htab_t copied_types
)
2498 case INTERNALVAR_INTEGER
:
2499 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2501 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2504 case INTERNALVAR_VALUE
:
2505 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2510 /* Update the internal variables and value history when OBJFILE is
2511 discarded; we must copy the types out of the objfile. New global types
2512 will be created for every convenience variable which currently points to
2513 this objfile's types, and the convenience variables will be adjusted to
2514 use the new global types. */
2517 preserve_values (struct objfile
*objfile
)
2519 htab_t copied_types
;
2520 struct internalvar
*var
;
2522 /* Create the hash table. We allocate on the objfile's obstack, since
2523 it is soon to be deleted. */
2524 copied_types
= create_copied_types_hash (objfile
);
2526 for (const value_ref_ptr
&item
: value_history
)
2527 preserve_one_value (item
.get (), objfile
, copied_types
);
2529 for (var
= internalvars
; var
; var
= var
->next
)
2530 preserve_one_internalvar (var
, objfile
, copied_types
);
2532 preserve_ext_lang_values (objfile
, copied_types
);
2534 htab_delete (copied_types
);
2538 show_convenience (const char *ignore
, int from_tty
)
2540 struct gdbarch
*gdbarch
= get_current_arch ();
2541 struct internalvar
*var
;
2543 struct value_print_options opts
;
2545 get_user_print_options (&opts
);
2546 for (var
= internalvars
; var
; var
= var
->next
)
2553 printf_filtered (("$%s = "), var
->name
);
2559 val
= value_of_internalvar (gdbarch
, var
);
2560 value_print (val
, gdb_stdout
, &opts
);
2562 catch (const gdb_exception_error
&ex
)
2564 fprintf_styled (gdb_stdout
, metadata_style
.style (),
2565 _("<error: %s>"), ex
.what ());
2568 printf_filtered (("\n"));
2572 /* This text does not mention convenience functions on purpose.
2573 The user can't create them except via Python, and if Python support
2574 is installed this message will never be printed ($_streq will
2576 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2577 "Convenience variables have "
2578 "names starting with \"$\";\n"
2579 "use \"set\" as in \"set "
2580 "$foo = 5\" to define them.\n"));
2588 value_from_xmethod (xmethod_worker_up
&&worker
)
2592 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2593 v
->lval
= lval_xcallable
;
2594 v
->location
.xm_worker
= worker
.release ();
2600 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2603 result_type_of_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2605 gdb_assert (value_type (method
)->code () == TYPE_CODE_XMETHOD
2606 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2608 return method
->location
.xm_worker
->get_result_type (argv
[0], argv
.slice (1));
2611 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2614 call_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2616 gdb_assert (value_type (method
)->code () == TYPE_CODE_XMETHOD
2617 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2619 return method
->location
.xm_worker
->invoke (argv
[0], argv
.slice (1));
2622 /* Extract a value as a C number (either long or double).
2623 Knows how to convert fixed values to double, or
2624 floating values to long.
2625 Does not deallocate the value. */
2628 value_as_long (struct value
*val
)
2630 /* This coerces arrays and functions, which is necessary (e.g.
2631 in disassemble_command). It also dereferences references, which
2632 I suspect is the most logical thing to do. */
2633 val
= coerce_array (val
);
2634 return unpack_long (value_type (val
), value_contents (val
));
2637 /* Extract a value as a C pointer. Does not deallocate the value.
2638 Note that val's type may not actually be a pointer; value_as_long
2639 handles all the cases. */
2641 value_as_address (struct value
*val
)
2643 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2645 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2646 whether we want this to be true eventually. */
2648 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2649 non-address (e.g. argument to "signal", "info break", etc.), or
2650 for pointers to char, in which the low bits *are* significant. */
2651 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2654 /* There are several targets (IA-64, PowerPC, and others) which
2655 don't represent pointers to functions as simply the address of
2656 the function's entry point. For example, on the IA-64, a
2657 function pointer points to a two-word descriptor, generated by
2658 the linker, which contains the function's entry point, and the
2659 value the IA-64 "global pointer" register should have --- to
2660 support position-independent code. The linker generates
2661 descriptors only for those functions whose addresses are taken.
2663 On such targets, it's difficult for GDB to convert an arbitrary
2664 function address into a function pointer; it has to either find
2665 an existing descriptor for that function, or call malloc and
2666 build its own. On some targets, it is impossible for GDB to
2667 build a descriptor at all: the descriptor must contain a jump
2668 instruction; data memory cannot be executed; and code memory
2671 Upon entry to this function, if VAL is a value of type `function'
2672 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2673 value_address (val) is the address of the function. This is what
2674 you'll get if you evaluate an expression like `main'. The call
2675 to COERCE_ARRAY below actually does all the usual unary
2676 conversions, which includes converting values of type `function'
2677 to `pointer to function'. This is the challenging conversion
2678 discussed above. Then, `unpack_long' will convert that pointer
2679 back into an address.
2681 So, suppose the user types `disassemble foo' on an architecture
2682 with a strange function pointer representation, on which GDB
2683 cannot build its own descriptors, and suppose further that `foo'
2684 has no linker-built descriptor. The address->pointer conversion
2685 will signal an error and prevent the command from running, even
2686 though the next step would have been to convert the pointer
2687 directly back into the same address.
2689 The following shortcut avoids this whole mess. If VAL is a
2690 function, just return its address directly. */
2691 if (value_type (val
)->code () == TYPE_CODE_FUNC
2692 || value_type (val
)->code () == TYPE_CODE_METHOD
)
2693 return value_address (val
);
2695 val
= coerce_array (val
);
2697 /* Some architectures (e.g. Harvard), map instruction and data
2698 addresses onto a single large unified address space. For
2699 instance: An architecture may consider a large integer in the
2700 range 0x10000000 .. 0x1000ffff to already represent a data
2701 addresses (hence not need a pointer to address conversion) while
2702 a small integer would still need to be converted integer to
2703 pointer to address. Just assume such architectures handle all
2704 integer conversions in a single function. */
2708 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2709 must admonish GDB hackers to make sure its behavior matches the
2710 compiler's, whenever possible.
2712 In general, I think GDB should evaluate expressions the same way
2713 the compiler does. When the user copies an expression out of
2714 their source code and hands it to a `print' command, they should
2715 get the same value the compiler would have computed. Any
2716 deviation from this rule can cause major confusion and annoyance,
2717 and needs to be justified carefully. In other words, GDB doesn't
2718 really have the freedom to do these conversions in clever and
2721 AndrewC pointed out that users aren't complaining about how GDB
2722 casts integers to pointers; they are complaining that they can't
2723 take an address from a disassembly listing and give it to `x/i'.
2724 This is certainly important.
2726 Adding an architecture method like integer_to_address() certainly
2727 makes it possible for GDB to "get it right" in all circumstances
2728 --- the target has complete control over how things get done, so
2729 people can Do The Right Thing for their target without breaking
2730 anyone else. The standard doesn't specify how integers get
2731 converted to pointers; usually, the ABI doesn't either, but
2732 ABI-specific code is a more reasonable place to handle it. */
2734 if (value_type (val
)->code () != TYPE_CODE_PTR
2735 && !TYPE_IS_REFERENCE (value_type (val
))
2736 && gdbarch_integer_to_address_p (gdbarch
))
2737 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2738 value_contents (val
));
2740 return unpack_long (value_type (val
), value_contents (val
));
2744 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2745 as a long, or as a double, assuming the raw data is described
2746 by type TYPE. Knows how to convert different sizes of values
2747 and can convert between fixed and floating point. We don't assume
2748 any alignment for the raw data. Return value is in host byte order.
2750 If you want functions and arrays to be coerced to pointers, and
2751 references to be dereferenced, call value_as_long() instead.
2753 C++: It is assumed that the front-end has taken care of
2754 all matters concerning pointers to members. A pointer
2755 to member which reaches here is considered to be equivalent
2756 to an INT (or some size). After all, it is only an offset. */
2759 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2761 enum bfd_endian byte_order
= type_byte_order (type
);
2762 enum type_code code
= type
->code ();
2763 int len
= TYPE_LENGTH (type
);
2764 int nosign
= type
->is_unsigned ();
2768 case TYPE_CODE_TYPEDEF
:
2769 return unpack_long (check_typedef (type
), valaddr
);
2770 case TYPE_CODE_ENUM
:
2771 case TYPE_CODE_FLAGS
:
2772 case TYPE_CODE_BOOL
:
2774 case TYPE_CODE_CHAR
:
2775 case TYPE_CODE_RANGE
:
2776 case TYPE_CODE_MEMBERPTR
:
2780 result
= extract_unsigned_integer (valaddr
, len
, byte_order
);
2782 result
= extract_signed_integer (valaddr
, len
, byte_order
);
2783 if (code
== TYPE_CODE_RANGE
)
2784 result
+= type
->bounds ()->bias
;
2789 case TYPE_CODE_DECFLOAT
:
2790 return target_float_to_longest (valaddr
, type
);
2794 case TYPE_CODE_RVALUE_REF
:
2795 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2796 whether we want this to be true eventually. */
2797 return extract_typed_address (valaddr
, type
);
2800 error (_("Value can't be converted to integer."));
2804 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2805 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2806 We don't assume any alignment for the raw data. Return value is in
2809 If you want functions and arrays to be coerced to pointers, and
2810 references to be dereferenced, call value_as_address() instead.
2812 C++: It is assumed that the front-end has taken care of
2813 all matters concerning pointers to members. A pointer
2814 to member which reaches here is considered to be equivalent
2815 to an INT (or some size). After all, it is only an offset. */
2818 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2820 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2821 whether we want this to be true eventually. */
2822 return unpack_long (type
, valaddr
);
2826 is_floating_value (struct value
*val
)
2828 struct type
*type
= check_typedef (value_type (val
));
2830 if (is_floating_type (type
))
2832 if (!target_float_is_valid (value_contents (val
), type
))
2833 error (_("Invalid floating value found in program."));
2841 /* Get the value of the FIELDNO'th field (which must be static) of
2845 value_static_field (struct type
*type
, int fieldno
)
2847 struct value
*retval
;
2849 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2851 case FIELD_LOC_KIND_PHYSADDR
:
2852 retval
= value_at_lazy (type
->field (fieldno
).type (),
2853 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2855 case FIELD_LOC_KIND_PHYSNAME
:
2857 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2858 /* TYPE_FIELD_NAME (type, fieldno); */
2859 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2861 if (sym
.symbol
== NULL
)
2863 /* With some compilers, e.g. HP aCC, static data members are
2864 reported as non-debuggable symbols. */
2865 struct bound_minimal_symbol msym
2866 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2867 struct type
*field_type
= type
->field (fieldno
).type ();
2870 retval
= allocate_optimized_out_value (field_type
);
2872 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2875 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2879 gdb_assert_not_reached ("unexpected field location kind");
2885 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2886 You have to be careful here, since the size of the data area for the value
2887 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2888 than the old enclosing type, you have to allocate more space for the
2892 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2894 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2896 check_type_length_before_alloc (new_encl_type
);
2898 .reset ((gdb_byte
*) xrealloc (val
->contents
.release (),
2899 TYPE_LENGTH (new_encl_type
)));
2902 val
->enclosing_type
= new_encl_type
;
2905 /* Given a value ARG1 (offset by OFFSET bytes)
2906 of a struct or union type ARG_TYPE,
2907 extract and return the value of one of its (non-static) fields.
2908 FIELDNO says which field. */
2911 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2912 int fieldno
, struct type
*arg_type
)
2916 struct gdbarch
*arch
= get_value_arch (arg1
);
2917 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2919 arg_type
= check_typedef (arg_type
);
2920 type
= arg_type
->field (fieldno
).type ();
2922 /* Call check_typedef on our type to make sure that, if TYPE
2923 is a TYPE_CODE_TYPEDEF, its length is set to the length
2924 of the target type instead of zero. However, we do not
2925 replace the typedef type by the target type, because we want
2926 to keep the typedef in order to be able to print the type
2927 description correctly. */
2928 check_typedef (type
);
2930 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2932 /* Handle packed fields.
2934 Create a new value for the bitfield, with bitpos and bitsize
2935 set. If possible, arrange offset and bitpos so that we can
2936 do a single aligned read of the size of the containing type.
2937 Otherwise, adjust offset to the byte containing the first
2938 bit. Assume that the address, offset, and embedded offset
2939 are sufficiently aligned. */
2941 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2942 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2944 v
= allocate_value_lazy (type
);
2945 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2946 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2947 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2948 v
->bitpos
= bitpos
% container_bitsize
;
2950 v
->bitpos
= bitpos
% 8;
2951 v
->offset
= (value_embedded_offset (arg1
)
2953 + (bitpos
- v
->bitpos
) / 8);
2954 set_value_parent (v
, arg1
);
2955 if (!value_lazy (arg1
))
2956 value_fetch_lazy (v
);
2958 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2960 /* This field is actually a base subobject, so preserve the
2961 entire object's contents for later references to virtual
2965 /* Lazy register values with offsets are not supported. */
2966 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2967 value_fetch_lazy (arg1
);
2969 /* We special case virtual inheritance here because this
2970 requires access to the contents, which we would rather avoid
2971 for references to ordinary fields of unavailable values. */
2972 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2973 boffset
= baseclass_offset (arg_type
, fieldno
,
2974 value_contents (arg1
),
2975 value_embedded_offset (arg1
),
2976 value_address (arg1
),
2979 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2981 if (value_lazy (arg1
))
2982 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2985 v
= allocate_value (value_enclosing_type (arg1
));
2986 value_contents_copy_raw (v
, 0, arg1
, 0,
2987 TYPE_LENGTH (value_enclosing_type (arg1
)));
2990 v
->offset
= value_offset (arg1
);
2991 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2993 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2995 /* Field is a dynamic data member. */
2997 gdb_assert (0 == offset
);
2998 /* We expect an already resolved data location. */
2999 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3000 /* For dynamic data types defer memory allocation
3001 until we actual access the value. */
3002 v
= allocate_value_lazy (type
);
3006 /* Plain old data member */
3007 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3008 / (HOST_CHAR_BIT
* unit_size
));
3010 /* Lazy register values with offsets are not supported. */
3011 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3012 value_fetch_lazy (arg1
);
3014 if (value_lazy (arg1
))
3015 v
= allocate_value_lazy (type
);
3018 v
= allocate_value (type
);
3019 value_contents_copy_raw (v
, value_embedded_offset (v
),
3020 arg1
, value_embedded_offset (arg1
) + offset
,
3021 type_length_units (type
));
3023 v
->offset
= (value_offset (arg1
) + offset
3024 + value_embedded_offset (arg1
));
3026 set_value_component_location (v
, arg1
);
3030 /* Given a value ARG1 of a struct or union type,
3031 extract and return the value of one of its (non-static) fields.
3032 FIELDNO says which field. */
3035 value_field (struct value
*arg1
, int fieldno
)
3037 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3040 /* Return a non-virtual function as a value.
3041 F is the list of member functions which contains the desired method.
3042 J is an index into F which provides the desired method.
3044 We only use the symbol for its address, so be happy with either a
3045 full symbol or a minimal symbol. */
3048 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3049 int j
, struct type
*type
,
3053 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3054 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3056 struct bound_minimal_symbol msym
;
3058 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3061 memset (&msym
, 0, sizeof (msym
));
3065 gdb_assert (sym
== NULL
);
3066 msym
= lookup_bound_minimal_symbol (physname
);
3067 if (msym
.minsym
== NULL
)
3071 v
= allocate_value (ftype
);
3072 VALUE_LVAL (v
) = lval_memory
;
3075 set_value_address (v
, BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (sym
)));
3079 /* The minimal symbol might point to a function descriptor;
3080 resolve it to the actual code address instead. */
3081 struct objfile
*objfile
= msym
.objfile
;
3082 struct gdbarch
*gdbarch
= objfile
->arch ();
3084 set_value_address (v
,
3085 gdbarch_convert_from_func_ptr_addr
3086 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), current_top_target ()));
3091 if (type
!= value_type (*arg1p
))
3092 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3093 value_addr (*arg1p
)));
3095 /* Move the `this' pointer according to the offset.
3096 VALUE_OFFSET (*arg1p) += offset; */
3107 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3108 LONGEST bitpos
, LONGEST bitsize
)
3110 enum bfd_endian byte_order
= type_byte_order (field_type
);
3115 LONGEST read_offset
;
3117 /* Read the minimum number of bytes required; there may not be
3118 enough bytes to read an entire ULONGEST. */
3119 field_type
= check_typedef (field_type
);
3121 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3124 bytes_read
= TYPE_LENGTH (field_type
);
3125 bitsize
= 8 * bytes_read
;
3128 read_offset
= bitpos
/ 8;
3130 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3131 bytes_read
, byte_order
);
3133 /* Extract bits. See comment above. */
3135 if (byte_order
== BFD_ENDIAN_BIG
)
3136 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3138 lsbcount
= (bitpos
% 8);
3141 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3142 If the field is signed, and is negative, then sign extend. */
3144 if (bitsize
< 8 * (int) sizeof (val
))
3146 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3148 if (!field_type
->is_unsigned ())
3150 if (val
& (valmask
^ (valmask
>> 1)))
3160 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3161 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3162 ORIGINAL_VALUE, which must not be NULL. See
3163 unpack_value_bits_as_long for more details. */
3166 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3167 LONGEST embedded_offset
, int fieldno
,
3168 const struct value
*val
, LONGEST
*result
)
3170 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3171 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3172 struct type
*field_type
= type
->field (fieldno
).type ();
3175 gdb_assert (val
!= NULL
);
3177 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3178 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3179 || !value_bits_available (val
, bit_offset
, bitsize
))
3182 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3187 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3188 object at VALADDR. See unpack_bits_as_long for more details. */
3191 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3193 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3194 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3195 struct type
*field_type
= type
->field (fieldno
).type ();
3197 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3200 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3201 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3202 the contents in DEST_VAL, zero or sign extending if the type of
3203 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3204 VAL. If the VAL's contents required to extract the bitfield from
3205 are unavailable/optimized out, DEST_VAL is correspondingly
3206 marked unavailable/optimized out. */
3209 unpack_value_bitfield (struct value
*dest_val
,
3210 LONGEST bitpos
, LONGEST bitsize
,
3211 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3212 const struct value
*val
)
3214 enum bfd_endian byte_order
;
3217 struct type
*field_type
= value_type (dest_val
);
3219 byte_order
= type_byte_order (field_type
);
3221 /* First, unpack and sign extend the bitfield as if it was wholly
3222 valid. Optimized out/unavailable bits are read as zero, but
3223 that's OK, as they'll end up marked below. If the VAL is
3224 wholly-invalid we may have skipped allocating its contents,
3225 though. See allocate_optimized_out_value. */
3226 if (valaddr
!= NULL
)
3230 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3232 store_signed_integer (value_contents_raw (dest_val
),
3233 TYPE_LENGTH (field_type
), byte_order
, num
);
3236 /* Now copy the optimized out / unavailability ranges to the right
3238 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3239 if (byte_order
== BFD_ENDIAN_BIG
)
3240 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3243 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3244 val
, src_bit_offset
, bitsize
);
3247 /* Return a new value with type TYPE, which is FIELDNO field of the
3248 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3249 of VAL. If the VAL's contents required to extract the bitfield
3250 from are unavailable/optimized out, the new value is
3251 correspondingly marked unavailable/optimized out. */
3254 value_field_bitfield (struct type
*type
, int fieldno
,
3255 const gdb_byte
*valaddr
,
3256 LONGEST embedded_offset
, const struct value
*val
)
3258 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3259 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3260 struct value
*res_val
= allocate_value (type
->field (fieldno
).type ());
3262 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3263 valaddr
, embedded_offset
, val
);
3268 /* Modify the value of a bitfield. ADDR points to a block of memory in
3269 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3270 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3271 indicate which bits (in target bit order) comprise the bitfield.
3272 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3273 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3276 modify_field (struct type
*type
, gdb_byte
*addr
,
3277 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3279 enum bfd_endian byte_order
= type_byte_order (type
);
3281 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3284 /* Normalize BITPOS. */
3288 /* If a negative fieldval fits in the field in question, chop
3289 off the sign extension bits. */
3290 if ((~fieldval
& ~(mask
>> 1)) == 0)
3293 /* Warn if value is too big to fit in the field in question. */
3294 if (0 != (fieldval
& ~mask
))
3296 /* FIXME: would like to include fieldval in the message, but
3297 we don't have a sprintf_longest. */
3298 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3300 /* Truncate it, otherwise adjoining fields may be corrupted. */
3304 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3305 false valgrind reports. */
3307 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3308 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3310 /* Shifting for bit field depends on endianness of the target machine. */
3311 if (byte_order
== BFD_ENDIAN_BIG
)
3312 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3314 oword
&= ~(mask
<< bitpos
);
3315 oword
|= fieldval
<< bitpos
;
3317 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3320 /* Pack NUM into BUF using a target format of TYPE. */
3323 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3325 enum bfd_endian byte_order
= type_byte_order (type
);
3328 type
= check_typedef (type
);
3329 len
= TYPE_LENGTH (type
);
3331 switch (type
->code ())
3333 case TYPE_CODE_RANGE
:
3334 num
-= type
->bounds ()->bias
;
3337 case TYPE_CODE_CHAR
:
3338 case TYPE_CODE_ENUM
:
3339 case TYPE_CODE_FLAGS
:
3340 case TYPE_CODE_BOOL
:
3341 case TYPE_CODE_MEMBERPTR
:
3342 store_signed_integer (buf
, len
, byte_order
, num
);
3346 case TYPE_CODE_RVALUE_REF
:
3348 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3352 case TYPE_CODE_DECFLOAT
:
3353 target_float_from_longest (buf
, type
, num
);
3357 error (_("Unexpected type (%d) encountered for integer constant."),
3363 /* Pack NUM into BUF using a target format of TYPE. */
3366 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3369 enum bfd_endian byte_order
;
3371 type
= check_typedef (type
);
3372 len
= TYPE_LENGTH (type
);
3373 byte_order
= type_byte_order (type
);
3375 switch (type
->code ())
3378 case TYPE_CODE_CHAR
:
3379 case TYPE_CODE_ENUM
:
3380 case TYPE_CODE_FLAGS
:
3381 case TYPE_CODE_BOOL
:
3382 case TYPE_CODE_RANGE
:
3383 case TYPE_CODE_MEMBERPTR
:
3384 store_unsigned_integer (buf
, len
, byte_order
, num
);
3388 case TYPE_CODE_RVALUE_REF
:
3390 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3394 case TYPE_CODE_DECFLOAT
:
3395 target_float_from_ulongest (buf
, type
, num
);
3399 error (_("Unexpected type (%d) encountered "
3400 "for unsigned integer constant."),
3406 /* Convert C numbers into newly allocated values. */
3409 value_from_longest (struct type
*type
, LONGEST num
)
3411 struct value
*val
= allocate_value (type
);
3413 pack_long (value_contents_raw (val
), type
, num
);
3418 /* Convert C unsigned numbers into newly allocated values. */
3421 value_from_ulongest (struct type
*type
, ULONGEST num
)
3423 struct value
*val
= allocate_value (type
);
3425 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3431 /* Create a value representing a pointer of type TYPE to the address
3435 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3437 struct value
*val
= allocate_value (type
);
3439 store_typed_address (value_contents_raw (val
),
3440 check_typedef (type
), addr
);
3444 /* Create and return a value object of TYPE containing the value D. The
3445 TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
3446 it is converted to target format. */
3449 value_from_host_double (struct type
*type
, double d
)
3451 struct value
*value
= allocate_value (type
);
3452 gdb_assert (type
->code () == TYPE_CODE_FLT
);
3453 target_float_from_host_double (value_contents_raw (value
),
3454 value_type (value
), d
);
3458 /* Create a value of type TYPE whose contents come from VALADDR, if it
3459 is non-null, and whose memory address (in the inferior) is
3460 ADDRESS. The type of the created value may differ from the passed
3461 type TYPE. Make sure to retrieve values new type after this call.
3462 Note that TYPE is not passed through resolve_dynamic_type; this is
3463 a special API intended for use only by Ada. */
3466 value_from_contents_and_address_unresolved (struct type
*type
,
3467 const gdb_byte
*valaddr
,
3472 if (valaddr
== NULL
)
3473 v
= allocate_value_lazy (type
);
3475 v
= value_from_contents (type
, valaddr
);
3476 VALUE_LVAL (v
) = lval_memory
;
3477 set_value_address (v
, address
);
3481 /* Create a value of type TYPE whose contents come from VALADDR, if it
3482 is non-null, and whose memory address (in the inferior) is
3483 ADDRESS. The type of the created value may differ from the passed
3484 type TYPE. Make sure to retrieve values new type after this call. */
3487 value_from_contents_and_address (struct type
*type
,
3488 const gdb_byte
*valaddr
,
3491 gdb::array_view
<const gdb_byte
> view
;
3492 if (valaddr
!= nullptr)
3493 view
= gdb::make_array_view (valaddr
, TYPE_LENGTH (type
));
3494 struct type
*resolved_type
= resolve_dynamic_type (type
, view
, address
);
3495 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3498 if (valaddr
== NULL
)
3499 v
= allocate_value_lazy (resolved_type
);
3501 v
= value_from_contents (resolved_type
, valaddr
);
3502 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3503 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3504 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3505 VALUE_LVAL (v
) = lval_memory
;
3506 set_value_address (v
, address
);
3510 /* Create a value of type TYPE holding the contents CONTENTS.
3511 The new value is `not_lval'. */
3514 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3516 struct value
*result
;
3518 result
= allocate_value (type
);
3519 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3523 /* Extract a value from the history file. Input will be of the form
3524 $digits or $$digits. See block comment above 'write_dollar_variable'
3528 value_from_history_ref (const char *h
, const char **endp
)
3540 /* Find length of numeral string. */
3541 for (; isdigit (h
[len
]); len
++)
3544 /* Make sure numeral string is not part of an identifier. */
3545 if (h
[len
] == '_' || isalpha (h
[len
]))
3548 /* Now collect the index value. */
3553 /* For some bizarre reason, "$$" is equivalent to "$$1",
3554 rather than to "$$0" as it ought to be! */
3562 index
= -strtol (&h
[2], &local_end
, 10);
3570 /* "$" is equivalent to "$0". */
3578 index
= strtol (&h
[1], &local_end
, 10);
3583 return access_value_history (index
);
3586 /* Get the component value (offset by OFFSET bytes) of a struct or
3587 union WHOLE. Component's type is TYPE. */
3590 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3594 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3595 v
= allocate_value_lazy (type
);
3598 v
= allocate_value (type
);
3599 value_contents_copy (v
, value_embedded_offset (v
),
3600 whole
, value_embedded_offset (whole
) + offset
,
3601 type_length_units (type
));
3603 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3604 set_value_component_location (v
, whole
);
3610 coerce_ref_if_computed (const struct value
*arg
)
3612 const struct lval_funcs
*funcs
;
3614 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3617 if (value_lval_const (arg
) != lval_computed
)
3620 funcs
= value_computed_funcs (arg
);
3621 if (funcs
->coerce_ref
== NULL
)
3624 return funcs
->coerce_ref (arg
);
3627 /* Look at value.h for description. */
3630 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3631 const struct type
*original_type
,
3632 struct value
*original_value
,
3633 CORE_ADDR original_value_address
)
3635 gdb_assert (original_type
->code () == TYPE_CODE_PTR
3636 || TYPE_IS_REFERENCE (original_type
));
3638 struct type
*original_target_type
= TYPE_TARGET_TYPE (original_type
);
3639 gdb::array_view
<const gdb_byte
> view
;
3640 struct type
*resolved_original_target_type
3641 = resolve_dynamic_type (original_target_type
, view
,
3642 original_value_address
);
3644 /* Re-adjust type. */
3645 deprecated_set_value_type (value
, resolved_original_target_type
);
3647 /* Add embedding info. */
3648 set_value_enclosing_type (value
, enc_type
);
3649 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3651 /* We may be pointing to an object of some derived type. */
3652 return value_full_object (value
, NULL
, 0, 0, 0);
3656 coerce_ref (struct value
*arg
)
3658 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3659 struct value
*retval
;
3660 struct type
*enc_type
;
3662 retval
= coerce_ref_if_computed (arg
);
3666 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3669 enc_type
= check_typedef (value_enclosing_type (arg
));
3670 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3672 CORE_ADDR addr
= unpack_pointer (value_type (arg
), value_contents (arg
));
3673 retval
= value_at_lazy (enc_type
, addr
);
3674 enc_type
= value_type (retval
);
3675 return readjust_indirect_value_type (retval
, enc_type
, value_type_arg_tmp
,
3680 coerce_array (struct value
*arg
)
3684 arg
= coerce_ref (arg
);
3685 type
= check_typedef (value_type (arg
));
3687 switch (type
->code ())
3689 case TYPE_CODE_ARRAY
:
3690 if (!type
->is_vector () && current_language
->c_style_arrays
)
3691 arg
= value_coerce_array (arg
);
3693 case TYPE_CODE_FUNC
:
3694 arg
= value_coerce_function (arg
);
3701 /* Return the return value convention that will be used for the
3704 enum return_value_convention
3705 struct_return_convention (struct gdbarch
*gdbarch
,
3706 struct value
*function
, struct type
*value_type
)
3708 enum type_code code
= value_type
->code ();
3710 if (code
== TYPE_CODE_ERROR
)
3711 error (_("Function return type unknown."));
3713 /* Probe the architecture for the return-value convention. */
3714 return gdbarch_return_value (gdbarch
, function
, value_type
,
3718 /* Return true if the function returning the specified type is using
3719 the convention of returning structures in memory (passing in the
3720 address as a hidden first parameter). */
3723 using_struct_return (struct gdbarch
*gdbarch
,
3724 struct value
*function
, struct type
*value_type
)
3726 if (value_type
->code () == TYPE_CODE_VOID
)
3727 /* A void return value is never in memory. See also corresponding
3728 code in "print_return_value". */
3731 return (struct_return_convention (gdbarch
, function
, value_type
)
3732 != RETURN_VALUE_REGISTER_CONVENTION
);
3735 /* Set the initialized field in a value struct. */
3738 set_value_initialized (struct value
*val
, int status
)
3740 val
->initialized
= status
;
3743 /* Return the initialized field in a value struct. */
3746 value_initialized (const struct value
*val
)
3748 return val
->initialized
;
3751 /* Helper for value_fetch_lazy when the value is a bitfield. */
3754 value_fetch_lazy_bitfield (struct value
*val
)
3756 gdb_assert (value_bitsize (val
) != 0);
3758 /* To read a lazy bitfield, read the entire enclosing value. This
3759 prevents reading the same block of (possibly volatile) memory once
3760 per bitfield. It would be even better to read only the containing
3761 word, but we have no way to record that just specific bits of a
3762 value have been fetched. */
3763 struct value
*parent
= value_parent (val
);
3765 if (value_lazy (parent
))
3766 value_fetch_lazy (parent
);
3768 unpack_value_bitfield (val
, value_bitpos (val
), value_bitsize (val
),
3769 value_contents_for_printing (parent
),
3770 value_offset (val
), parent
);
3773 /* Helper for value_fetch_lazy when the value is in memory. */
3776 value_fetch_lazy_memory (struct value
*val
)
3778 gdb_assert (VALUE_LVAL (val
) == lval_memory
);
3780 CORE_ADDR addr
= value_address (val
);
3781 struct type
*type
= check_typedef (value_enclosing_type (val
));
3783 if (TYPE_LENGTH (type
))
3784 read_value_memory (val
, 0, value_stack (val
),
3785 addr
, value_contents_all_raw (val
),
3786 type_length_units (type
));
3789 /* Helper for value_fetch_lazy when the value is in a register. */
3792 value_fetch_lazy_register (struct value
*val
)
3794 struct frame_info
*next_frame
;
3796 struct type
*type
= check_typedef (value_type (val
));
3797 struct value
*new_val
= val
, *mark
= value_mark ();
3799 /* Offsets are not supported here; lazy register values must
3800 refer to the entire register. */
3801 gdb_assert (value_offset (val
) == 0);
3803 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3805 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3807 next_frame
= frame_find_by_id (next_frame_id
);
3808 regnum
= VALUE_REGNUM (new_val
);
3810 gdb_assert (next_frame
!= NULL
);
3812 /* Convertible register routines are used for multi-register
3813 values and for interpretation in different types
3814 (e.g. float or int from a double register). Lazy
3815 register values should have the register's natural type,
3816 so they do not apply. */
3817 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3820 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3821 Since a "->next" operation was performed when setting
3822 this field, we do not need to perform a "next" operation
3823 again when unwinding the register. That's why
3824 frame_unwind_register_value() is called here instead of
3825 get_frame_register_value(). */
3826 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3828 /* If we get another lazy lval_register value, it means the
3829 register is found by reading it from NEXT_FRAME's next frame.
3830 frame_unwind_register_value should never return a value with
3831 the frame id pointing to NEXT_FRAME. If it does, it means we
3832 either have two consecutive frames with the same frame id
3833 in the frame chain, or some code is trying to unwind
3834 behind get_prev_frame's back (e.g., a frame unwind
3835 sniffer trying to unwind), bypassing its validations. In
3836 any case, it should always be an internal error to end up
3837 in this situation. */
3838 if (VALUE_LVAL (new_val
) == lval_register
3839 && value_lazy (new_val
)
3840 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3841 internal_error (__FILE__
, __LINE__
,
3842 _("infinite loop while fetching a register"));
3845 /* If it's still lazy (for instance, a saved register on the
3846 stack), fetch it. */
3847 if (value_lazy (new_val
))
3848 value_fetch_lazy (new_val
);
3850 /* Copy the contents and the unavailability/optimized-out
3851 meta-data from NEW_VAL to VAL. */
3852 set_value_lazy (val
, 0);
3853 value_contents_copy (val
, value_embedded_offset (val
),
3854 new_val
, value_embedded_offset (new_val
),
3855 type_length_units (type
));
3859 struct gdbarch
*gdbarch
;
3860 struct frame_info
*frame
;
3861 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3862 so that the frame level will be shown correctly. */
3863 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3864 regnum
= VALUE_REGNUM (val
);
3865 gdbarch
= get_frame_arch (frame
);
3867 fprintf_unfiltered (gdb_stdlog
,
3868 "{ value_fetch_lazy "
3869 "(frame=%d,regnum=%d(%s),...) ",
3870 frame_relative_level (frame
), regnum
,
3871 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3873 fprintf_unfiltered (gdb_stdlog
, "->");
3874 if (value_optimized_out (new_val
))
3876 fprintf_unfiltered (gdb_stdlog
, " ");
3877 val_print_optimized_out (new_val
, gdb_stdlog
);
3882 const gdb_byte
*buf
= value_contents (new_val
);
3884 if (VALUE_LVAL (new_val
) == lval_register
)
3885 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3886 VALUE_REGNUM (new_val
));
3887 else if (VALUE_LVAL (new_val
) == lval_memory
)
3888 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3890 value_address (new_val
)));
3892 fprintf_unfiltered (gdb_stdlog
, " computed");
3894 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3895 fprintf_unfiltered (gdb_stdlog
, "[");
3896 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3897 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3898 fprintf_unfiltered (gdb_stdlog
, "]");
3901 fprintf_unfiltered (gdb_stdlog
, " }\n");
3904 /* Dispose of the intermediate values. This prevents
3905 watchpoints from trying to watch the saved frame pointer. */
3906 value_free_to_mark (mark
);
3909 /* Load the actual content of a lazy value. Fetch the data from the
3910 user's process and clear the lazy flag to indicate that the data in
3911 the buffer is valid.
3913 If the value is zero-length, we avoid calling read_memory, which
3914 would abort. We mark the value as fetched anyway -- all 0 bytes of
3918 value_fetch_lazy (struct value
*val
)
3920 gdb_assert (value_lazy (val
));
3921 allocate_value_contents (val
);
3922 /* A value is either lazy, or fully fetched. The
3923 availability/validity is only established as we try to fetch a
3925 gdb_assert (val
->optimized_out
.empty ());
3926 gdb_assert (val
->unavailable
.empty ());
3927 if (value_bitsize (val
))
3928 value_fetch_lazy_bitfield (val
);
3929 else if (VALUE_LVAL (val
) == lval_memory
)
3930 value_fetch_lazy_memory (val
);
3931 else if (VALUE_LVAL (val
) == lval_register
)
3932 value_fetch_lazy_register (val
);
3933 else if (VALUE_LVAL (val
) == lval_computed
3934 && value_computed_funcs (val
)->read
!= NULL
)
3935 value_computed_funcs (val
)->read (val
);
3937 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3939 set_value_lazy (val
, 0);
3942 /* Implementation of the convenience function $_isvoid. */
3944 static struct value
*
3945 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3946 const struct language_defn
*language
,
3947 void *cookie
, int argc
, struct value
**argv
)
3952 error (_("You must provide one argument for $_isvoid."));
3954 ret
= value_type (argv
[0])->code () == TYPE_CODE_VOID
;
3956 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3959 /* Implementation of the convenience function $_creal. Extracts the
3960 real part from a complex number. */
3962 static struct value
*
3963 creal_internal_fn (struct gdbarch
*gdbarch
,
3964 const struct language_defn
*language
,
3965 void *cookie
, int argc
, struct value
**argv
)
3968 error (_("You must provide one argument for $_creal."));
3970 value
*cval
= argv
[0];
3971 type
*ctype
= check_typedef (value_type (cval
));
3972 if (ctype
->code () != TYPE_CODE_COMPLEX
)
3973 error (_("expected a complex number"));
3974 return value_real_part (cval
);
3977 /* Implementation of the convenience function $_cimag. Extracts the
3978 imaginary part from a complex number. */
3980 static struct value
*
3981 cimag_internal_fn (struct gdbarch
*gdbarch
,
3982 const struct language_defn
*language
,
3983 void *cookie
, int argc
,
3984 struct value
**argv
)
3987 error (_("You must provide one argument for $_cimag."));
3989 value
*cval
= argv
[0];
3990 type
*ctype
= check_typedef (value_type (cval
));
3991 if (ctype
->code () != TYPE_CODE_COMPLEX
)
3992 error (_("expected a complex number"));
3993 return value_imaginary_part (cval
);
4000 /* Test the ranges_contain function. */
4003 test_ranges_contain ()
4005 std::vector
<range
> ranges
;
4011 ranges
.push_back (r
);
4016 ranges
.push_back (r
);
4019 SELF_CHECK (!ranges_contain (ranges
, 2, 5));
4021 SELF_CHECK (ranges_contain (ranges
, 9, 5));
4023 SELF_CHECK (ranges_contain (ranges
, 10, 2));
4025 SELF_CHECK (ranges_contain (ranges
, 10, 5));
4027 SELF_CHECK (ranges_contain (ranges
, 13, 6));
4029 SELF_CHECK (ranges_contain (ranges
, 14, 5));
4031 SELF_CHECK (!ranges_contain (ranges
, 15, 4));
4033 SELF_CHECK (!ranges_contain (ranges
, 16, 4));
4035 SELF_CHECK (ranges_contain (ranges
, 16, 6));
4037 SELF_CHECK (ranges_contain (ranges
, 21, 1));
4039 SELF_CHECK (ranges_contain (ranges
, 21, 5));
4041 SELF_CHECK (!ranges_contain (ranges
, 26, 3));
4044 /* Check that RANGES contains the same ranges as EXPECTED. */
4047 check_ranges_vector (gdb::array_view
<const range
> ranges
,
4048 gdb::array_view
<const range
> expected
)
4050 return ranges
== expected
;
4053 /* Test the insert_into_bit_range_vector function. */
4056 test_insert_into_bit_range_vector ()
4058 std::vector
<range
> ranges
;
4062 insert_into_bit_range_vector (&ranges
, 10, 5);
4063 static const range expected
[] = {
4066 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4071 insert_into_bit_range_vector (&ranges
, 11, 4);
4072 static const range expected
= {10, 5};
4073 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4076 /* [10, 14] [20, 24] */
4078 insert_into_bit_range_vector (&ranges
, 20, 5);
4079 static const range expected
[] = {
4083 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4086 /* [10, 14] [17, 24] */
4088 insert_into_bit_range_vector (&ranges
, 17, 5);
4089 static const range expected
[] = {
4093 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4096 /* [2, 8] [10, 14] [17, 24] */
4098 insert_into_bit_range_vector (&ranges
, 2, 7);
4099 static const range expected
[] = {
4104 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4107 /* [2, 14] [17, 24] */
4109 insert_into_bit_range_vector (&ranges
, 9, 1);
4110 static const range expected
[] = {
4114 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4117 /* [2, 14] [17, 24] */
4119 insert_into_bit_range_vector (&ranges
, 9, 1);
4120 static const range expected
[] = {
4124 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4129 insert_into_bit_range_vector (&ranges
, 4, 30);
4130 static const range expected
= {2, 32};
4131 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4135 } /* namespace selftests */
4136 #endif /* GDB_SELF_TEST */
4138 void _initialize_values ();
4140 _initialize_values ()
4142 add_cmd ("convenience", no_class
, show_convenience
, _("\
4143 Debugger convenience (\"$foo\") variables and functions.\n\
4144 Convenience variables are created when you assign them values;\n\
4145 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4147 A few convenience variables are given values automatically:\n\
4148 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4149 \"$__\" holds the contents of the last address examined with \"x\"."
4152 Convenience functions are defined via the Python API."
4155 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4157 add_cmd ("values", no_set_class
, show_values
, _("\
4158 Elements of value history around item number IDX (or last ten)."),
4161 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4162 Initialize a convenience variable if necessary.\n\
4163 init-if-undefined VARIABLE = EXPRESSION\n\
4164 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4165 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4166 VARIABLE is already initialized."));
4168 add_prefix_cmd ("function", no_class
, function_command
, _("\
4169 Placeholder command for showing help on convenience functions."),
4170 &functionlist
, "function ", 0, &cmdlist
);
4172 add_internal_function ("_isvoid", _("\
4173 Check whether an expression is void.\n\
4174 Usage: $_isvoid (expression)\n\
4175 Return 1 if the expression is void, zero otherwise."),
4176 isvoid_internal_fn
, NULL
);
4178 add_internal_function ("_creal", _("\
4179 Extract the real part of a complex number.\n\
4180 Usage: $_creal (expression)\n\
4181 Return the real part of a complex number, the type depends on the\n\
4182 type of a complex number."),
4183 creal_internal_fn
, NULL
);
4185 add_internal_function ("_cimag", _("\
4186 Extract the imaginary part of a complex number.\n\
4187 Usage: $_cimag (expression)\n\
4188 Return the imaginary part of a complex number, the type depends on the\n\
4189 type of a complex number."),
4190 cimag_internal_fn
, NULL
);
4192 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4193 class_support
, &max_value_size
, _("\
4194 Set maximum sized value gdb will load from the inferior."), _("\
4195 Show maximum sized value gdb will load from the inferior."), _("\
4196 Use this to control the maximum size, in bytes, of a value that gdb\n\
4197 will load from the inferior. Setting this value to 'unlimited'\n\
4198 disables checking.\n\
4199 Setting this does not invalidate already allocated values, it only\n\
4200 prevents future values, larger than this size, from being allocated."),
4202 show_max_value_size
,
4203 &setlist
, &showlist
);
4205 selftests::register_test ("ranges_contain", selftests::test_ranges_contain
);
4206 selftests::register_test ("insert_into_bit_range_vector",
4207 selftests::test_insert_into_bit_range_vector
);
4216 all_values
.clear ();