1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2019 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 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
277 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
280 /* The number of references to this value. When a value is created,
281 the value chain holds a reference, so REFERENCE_COUNT is 1. If
282 release_value is called, this value is removed from the chain but
283 the caller of release_value now has a reference to this value.
284 The caller must arrange for a call to value_free later. */
285 int reference_count
= 1;
287 /* Only used for bitfields; the containing value. This allows a
288 single read from the target when displaying multiple
290 value_ref_ptr parent
;
292 /* Type of the value. */
295 /* If a value represents a C++ object, then the `type' field gives
296 the object's compile-time type. If the object actually belongs
297 to some class derived from `type', perhaps with other base
298 classes and additional members, then `type' is just a subobject
299 of the real thing, and the full object is probably larger than
300 `type' would suggest.
302 If `type' is a dynamic class (i.e. one with a vtable), then GDB
303 can actually determine the object's run-time type by looking at
304 the run-time type information in the vtable. When this
305 information is available, we may elect to read in the entire
306 object, for several reasons:
308 - When printing the value, the user would probably rather see the
309 full object, not just the limited portion apparent from the
312 - If `type' has virtual base classes, then even printing `type'
313 alone may require reaching outside the `type' portion of the
314 object to wherever the virtual base class has been stored.
316 When we store the entire object, `enclosing_type' is the run-time
317 type -- the complete object -- and `embedded_offset' is the
318 offset of `type' within that larger type, in target addressable memory
319 units. The value_contents() macro takes `embedded_offset' into account,
320 so most GDB code continues to see the `type' portion of the value, just
321 as the inferior would.
323 If `type' is a pointer to an object, then `enclosing_type' is a
324 pointer to the object's run-time type, and `pointed_to_offset' is
325 the offset in target addressable memory units from the full object
326 to the pointed-to object -- that is, the value `embedded_offset' would
327 have if we followed the pointer and fetched the complete object.
328 (I don't really see the point. Why not just determine the
329 run-time type when you indirect, and avoid the special case? The
330 contents don't matter until you indirect anyway.)
332 If we're not doing anything fancy, `enclosing_type' is equal to
333 `type', and `embedded_offset' is zero, so everything works
335 struct type
*enclosing_type
;
336 LONGEST embedded_offset
= 0;
337 LONGEST pointed_to_offset
= 0;
339 /* Actual contents of the value. Target byte-order. NULL or not
340 valid if lazy is nonzero. */
341 gdb::unique_xmalloc_ptr
<gdb_byte
> contents
;
343 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
344 rather than available, since the common and default case is for a
345 value to be available. This is filled in at value read time.
346 The unavailable ranges are tracked in bits. Note that a contents
347 bit that has been optimized out doesn't really exist in the
348 program, so it can't be marked unavailable either. */
349 std::vector
<range
> unavailable
;
351 /* Likewise, but for optimized out contents (a chunk of the value of
352 a variable that does not actually exist in the program). If LVAL
353 is lval_register, this is a register ($pc, $sp, etc., never a
354 program variable) that has not been saved in the frame. Not
355 saved registers and optimized-out program variables values are
356 treated pretty much the same, except not-saved registers have a
357 different string representation and related error strings. */
358 std::vector
<range
> optimized_out
;
364 get_value_arch (const struct value
*value
)
366 return get_type_arch (value_type (value
));
370 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
372 gdb_assert (!value
->lazy
);
374 return !ranges_contain (value
->unavailable
, offset
, length
);
378 value_bytes_available (const struct value
*value
,
379 LONGEST offset
, LONGEST length
)
381 return value_bits_available (value
,
382 offset
* TARGET_CHAR_BIT
,
383 length
* TARGET_CHAR_BIT
);
387 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
389 gdb_assert (!value
->lazy
);
391 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
395 value_entirely_available (struct value
*value
)
397 /* We can only tell whether the whole value is available when we try
400 value_fetch_lazy (value
);
402 if (value
->unavailable
.empty ())
407 /* Returns true if VALUE is entirely covered by RANGES. If the value
408 is lazy, it'll be read now. Note that RANGE is a pointer to
409 pointer because reading the value might change *RANGE. */
412 value_entirely_covered_by_range_vector (struct value
*value
,
413 const std::vector
<range
> &ranges
)
415 /* We can only tell whether the whole value is optimized out /
416 unavailable when we try to read it. */
418 value_fetch_lazy (value
);
420 if (ranges
.size () == 1)
422 const struct range
&t
= ranges
[0];
425 && t
.length
== (TARGET_CHAR_BIT
426 * TYPE_LENGTH (value_enclosing_type (value
))))
434 value_entirely_unavailable (struct value
*value
)
436 return value_entirely_covered_by_range_vector (value
, value
->unavailable
);
440 value_entirely_optimized_out (struct value
*value
)
442 return value_entirely_covered_by_range_vector (value
, value
->optimized_out
);
445 /* Insert into the vector pointed to by VECTORP the bit range starting of
446 OFFSET bits, and extending for the next LENGTH bits. */
449 insert_into_bit_range_vector (std::vector
<range
> *vectorp
,
450 LONGEST offset
, LONGEST length
)
454 /* Insert the range sorted. If there's overlap or the new range
455 would be contiguous with an existing range, merge. */
457 newr
.offset
= offset
;
458 newr
.length
= length
;
460 /* Do a binary search for the position the given range would be
461 inserted if we only considered the starting OFFSET of ranges.
462 Call that position I. Since we also have LENGTH to care for
463 (this is a range afterall), we need to check if the _previous_
464 range overlaps the I range. E.g., calling R the new range:
466 #1 - overlaps with previous
470 |---| |---| |------| ... |--|
475 In the case #1 above, the binary search would return `I=1',
476 meaning, this OFFSET should be inserted at position 1, and the
477 current position 1 should be pushed further (and become 2). But,
478 note that `0' overlaps with R, so we want to merge them.
480 A similar consideration needs to be taken if the new range would
481 be contiguous with the previous range:
483 #2 - contiguous with previous
487 |--| |---| |------| ... |--|
492 If there's no overlap with the previous range, as in:
494 #3 - not overlapping and not contiguous
498 |--| |---| |------| ... |--|
505 #4 - R is the range with lowest offset
509 |--| |---| |------| ... |--|
514 ... we just push the new range to I.
516 All the 4 cases above need to consider that the new range may
517 also overlap several of the ranges that follow, or that R may be
518 contiguous with the following range, and merge. E.g.,
520 #5 - overlapping following ranges
523 |------------------------|
524 |--| |---| |------| ... |--|
533 |--| |---| |------| ... |--|
540 auto i
= std::lower_bound (vectorp
->begin (), vectorp
->end (), newr
);
541 if (i
> vectorp
->begin ())
543 struct range
&bef
= *(i
- 1);
545 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
548 ULONGEST l
= std::min (bef
.offset
, offset
);
549 ULONGEST h
= std::max (bef
.offset
+ bef
.length
, offset
+ length
);
555 else if (offset
== bef
.offset
+ bef
.length
)
558 bef
.length
+= length
;
564 i
= vectorp
->insert (i
, newr
);
570 i
= vectorp
->insert (i
, newr
);
573 /* Check whether the ranges following the one we've just added or
574 touched can be folded in (#5 above). */
575 if (i
!= vectorp
->end () && i
+ 1 < vectorp
->end ())
580 /* Get the range we just touched. */
581 struct range
&t
= *i
;
585 for (; i
< vectorp
->end (); i
++)
587 struct range
&r
= *i
;
588 if (r
.offset
<= t
.offset
+ t
.length
)
592 l
= std::min (t
.offset
, r
.offset
);
593 h
= std::max (t
.offset
+ t
.length
, r
.offset
+ r
.length
);
602 /* If we couldn't merge this one, we won't be able to
603 merge following ones either, since the ranges are
604 always sorted by OFFSET. */
610 vectorp
->erase (next
, next
+ removed
);
615 mark_value_bits_unavailable (struct value
*value
,
616 LONGEST offset
, LONGEST length
)
618 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
622 mark_value_bytes_unavailable (struct value
*value
,
623 LONGEST offset
, LONGEST length
)
625 mark_value_bits_unavailable (value
,
626 offset
* TARGET_CHAR_BIT
,
627 length
* TARGET_CHAR_BIT
);
630 /* Find the first range in RANGES that overlaps the range defined by
631 OFFSET and LENGTH, starting at element POS in the RANGES vector,
632 Returns the index into RANGES where such overlapping range was
633 found, or -1 if none was found. */
636 find_first_range_overlap (const std::vector
<range
> *ranges
, int pos
,
637 LONGEST offset
, LONGEST length
)
641 for (i
= pos
; i
< ranges
->size (); i
++)
643 const range
&r
= (*ranges
)[i
];
644 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
651 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
652 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
655 It must always be the case that:
656 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
658 It is assumed that memory can be accessed from:
659 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
661 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
662 / TARGET_CHAR_BIT) */
664 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
665 const gdb_byte
*ptr2
, size_t offset2_bits
,
668 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
669 == offset2_bits
% TARGET_CHAR_BIT
);
671 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
674 gdb_byte mask
, b1
, b2
;
676 /* The offset from the base pointers PTR1 and PTR2 is not a complete
677 number of bytes. A number of bits up to either the next exact
678 byte boundary, or LENGTH_BITS (which ever is sooner) will be
680 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
681 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
682 mask
= (1 << bits
) - 1;
684 if (length_bits
< bits
)
686 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
690 /* Now load the two bytes and mask off the bits we care about. */
691 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
692 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
697 /* Now update the length and offsets to take account of the bits
698 we've just compared. */
700 offset1_bits
+= bits
;
701 offset2_bits
+= bits
;
704 if (length_bits
% TARGET_CHAR_BIT
!= 0)
708 gdb_byte mask
, b1
, b2
;
710 /* The length is not an exact number of bytes. After the previous
711 IF.. block then the offsets are byte aligned, or the
712 length is zero (in which case this code is not reached). Compare
713 a number of bits at the end of the region, starting from an exact
715 bits
= length_bits
% TARGET_CHAR_BIT
;
716 o1
= offset1_bits
+ length_bits
- bits
;
717 o2
= offset2_bits
+ length_bits
- bits
;
719 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
720 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
722 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
723 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
725 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
726 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
736 /* We've now taken care of any stray "bits" at the start, or end of
737 the region to compare, the remainder can be covered with a simple
739 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
740 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
741 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
743 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
744 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
745 length_bits
/ TARGET_CHAR_BIT
);
748 /* Length is zero, regions match. */
752 /* Helper struct for find_first_range_overlap_and_match and
753 value_contents_bits_eq. Keep track of which slot of a given ranges
754 vector have we last looked at. */
756 struct ranges_and_idx
759 const std::vector
<range
> *ranges
;
761 /* The range we've last found in RANGES. Given ranges are sorted,
762 we can start the next lookup here. */
766 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
767 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
768 ranges starting at OFFSET2 bits. Return true if the ranges match
769 and fill in *L and *H with the overlapping window relative to
770 (both) OFFSET1 or OFFSET2. */
773 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
774 struct ranges_and_idx
*rp2
,
775 LONGEST offset1
, LONGEST offset2
,
776 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
778 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
780 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
783 if (rp1
->idx
== -1 && rp2
->idx
== -1)
789 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
793 const range
*r1
, *r2
;
797 r1
= &(*rp1
->ranges
)[rp1
->idx
];
798 r2
= &(*rp2
->ranges
)[rp2
->idx
];
800 /* Get the unavailable windows intersected by the incoming
801 ranges. The first and last ranges that overlap the argument
802 range may be wider than said incoming arguments ranges. */
803 l1
= std::max (offset1
, r1
->offset
);
804 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
806 l2
= std::max (offset2
, r2
->offset
);
807 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
809 /* Make them relative to the respective start offsets, so we can
810 compare them for equality. */
817 /* Different ranges, no match. */
818 if (l1
!= l2
|| h1
!= h2
)
827 /* Helper function for value_contents_eq. The only difference is that
828 this function is bit rather than byte based.
830 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
831 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
832 Return true if the available bits match. */
835 value_contents_bits_eq (const struct value
*val1
, int offset1
,
836 const struct value
*val2
, int offset2
,
839 /* Each array element corresponds to a ranges source (unavailable,
840 optimized out). '1' is for VAL1, '2' for VAL2. */
841 struct ranges_and_idx rp1
[2], rp2
[2];
843 /* See function description in value.h. */
844 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
846 /* We shouldn't be trying to compare past the end of the values. */
847 gdb_assert (offset1
+ length
848 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
849 gdb_assert (offset2
+ length
850 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
852 memset (&rp1
, 0, sizeof (rp1
));
853 memset (&rp2
, 0, sizeof (rp2
));
854 rp1
[0].ranges
= &val1
->unavailable
;
855 rp2
[0].ranges
= &val2
->unavailable
;
856 rp1
[1].ranges
= &val1
->optimized_out
;
857 rp2
[1].ranges
= &val2
->optimized_out
;
861 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
864 for (i
= 0; i
< 2; i
++)
866 ULONGEST l_tmp
, h_tmp
;
868 /* The contents only match equal if the invalid/unavailable
869 contents ranges match as well. */
870 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
871 offset1
, offset2
, length
,
875 /* We're interested in the lowest/first range found. */
876 if (i
== 0 || l_tmp
< l
)
883 /* Compare the available/valid contents. */
884 if (memcmp_with_bit_offsets (val1
->contents
.get (), offset1
,
885 val2
->contents
.get (), offset2
, l
) != 0)
897 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
898 const struct value
*val2
, LONGEST offset2
,
901 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
902 val2
, offset2
* TARGET_CHAR_BIT
,
903 length
* TARGET_CHAR_BIT
);
907 /* The value-history records all the values printed by print commands
908 during this session. */
910 static std::vector
<value_ref_ptr
> value_history
;
913 /* List of all value objects currently allocated
914 (except for those released by calls to release_value)
915 This is so they can be freed after each command. */
917 static std::vector
<value_ref_ptr
> all_values
;
919 /* Allocate a lazy value for type TYPE. Its actual content is
920 "lazily" allocated too: the content field of the return value is
921 NULL; it will be allocated when it is fetched from the target. */
924 allocate_value_lazy (struct type
*type
)
928 /* Call check_typedef on our type to make sure that, if TYPE
929 is a TYPE_CODE_TYPEDEF, its length is set to the length
930 of the target type instead of zero. However, we do not
931 replace the typedef type by the target type, because we want
932 to keep the typedef in order to be able to set the VAL's type
933 description correctly. */
934 check_typedef (type
);
936 val
= new struct value (type
);
938 /* Values start out on the all_values chain. */
939 all_values
.emplace_back (val
);
944 /* The maximum size, in bytes, that GDB will try to allocate for a value.
945 The initial value of 64k was not selected for any specific reason, it is
946 just a reasonable starting point. */
948 static int max_value_size
= 65536; /* 64k bytes */
950 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
951 LONGEST, otherwise GDB will not be able to parse integer values from the
952 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
953 be unable to parse "set max-value-size 2".
955 As we want a consistent GDB experience across hosts with different sizes
956 of LONGEST, this arbitrary minimum value was selected, so long as this
957 is bigger than LONGEST on all GDB supported hosts we're fine. */
959 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
960 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
962 /* Implement the "set max-value-size" command. */
965 set_max_value_size (const char *args
, int from_tty
,
966 struct cmd_list_element
*c
)
968 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
970 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
972 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
973 error (_("max-value-size set too low, increasing to %d bytes"),
978 /* Implement the "show max-value-size" command. */
981 show_max_value_size (struct ui_file
*file
, int from_tty
,
982 struct cmd_list_element
*c
, const char *value
)
984 if (max_value_size
== -1)
985 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
987 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
991 /* Called before we attempt to allocate or reallocate a buffer for the
992 contents of a value. TYPE is the type of the value for which we are
993 allocating the buffer. If the buffer is too large (based on the user
994 controllable setting) then throw an error. If this function returns
995 then we should attempt to allocate the buffer. */
998 check_type_length_before_alloc (const struct type
*type
)
1000 unsigned int length
= TYPE_LENGTH (type
);
1002 if (max_value_size
> -1 && length
> max_value_size
)
1004 if (TYPE_NAME (type
) != NULL
)
1005 error (_("value of type `%s' requires %u bytes, which is more "
1006 "than max-value-size"), TYPE_NAME (type
), length
);
1008 error (_("value requires %u bytes, which is more than "
1009 "max-value-size"), length
);
1013 /* Allocate the contents of VAL if it has not been allocated yet. */
1016 allocate_value_contents (struct value
*val
)
1020 check_type_length_before_alloc (val
->enclosing_type
);
1022 ((gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
)));
1026 /* Allocate a value and its contents for type TYPE. */
1029 allocate_value (struct type
*type
)
1031 struct value
*val
= allocate_value_lazy (type
);
1033 allocate_value_contents (val
);
1038 /* Allocate a value that has the correct length
1039 for COUNT repetitions of type TYPE. */
1042 allocate_repeat_value (struct type
*type
, int count
)
1044 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1045 /* FIXME-type-allocation: need a way to free this type when we are
1047 struct type
*array_type
1048 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1050 return allocate_value (array_type
);
1054 allocate_computed_value (struct type
*type
,
1055 const struct lval_funcs
*funcs
,
1058 struct value
*v
= allocate_value_lazy (type
);
1060 VALUE_LVAL (v
) = lval_computed
;
1061 v
->location
.computed
.funcs
= funcs
;
1062 v
->location
.computed
.closure
= closure
;
1067 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1070 allocate_optimized_out_value (struct type
*type
)
1072 struct value
*retval
= allocate_value_lazy (type
);
1074 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1075 set_value_lazy (retval
, 0);
1079 /* Accessor methods. */
1082 value_type (const struct value
*value
)
1087 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1093 value_offset (const struct value
*value
)
1095 return value
->offset
;
1098 set_value_offset (struct value
*value
, LONGEST offset
)
1100 value
->offset
= offset
;
1104 value_bitpos (const struct value
*value
)
1106 return value
->bitpos
;
1109 set_value_bitpos (struct value
*value
, LONGEST bit
)
1111 value
->bitpos
= bit
;
1115 value_bitsize (const struct value
*value
)
1117 return value
->bitsize
;
1120 set_value_bitsize (struct value
*value
, LONGEST bit
)
1122 value
->bitsize
= bit
;
1126 value_parent (const struct value
*value
)
1128 return value
->parent
.get ();
1134 set_value_parent (struct value
*value
, struct value
*parent
)
1136 value
->parent
= value_ref_ptr::new_reference (parent
);
1140 value_contents_raw (struct value
*value
)
1142 struct gdbarch
*arch
= get_value_arch (value
);
1143 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1145 allocate_value_contents (value
);
1146 return value
->contents
.get () + value
->embedded_offset
* unit_size
;
1150 value_contents_all_raw (struct value
*value
)
1152 allocate_value_contents (value
);
1153 return value
->contents
.get ();
1157 value_enclosing_type (const struct value
*value
)
1159 return value
->enclosing_type
;
1162 /* Look at value.h for description. */
1165 value_actual_type (struct value
*value
, int resolve_simple_types
,
1166 int *real_type_found
)
1168 struct value_print_options opts
;
1169 struct type
*result
;
1171 get_user_print_options (&opts
);
1173 if (real_type_found
)
1174 *real_type_found
= 0;
1175 result
= value_type (value
);
1176 if (opts
.objectprint
)
1178 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1179 fetch its rtti type. */
1180 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1181 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1183 && !value_optimized_out (value
))
1185 struct type
*real_type
;
1187 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1190 if (real_type_found
)
1191 *real_type_found
= 1;
1195 else if (resolve_simple_types
)
1197 if (real_type_found
)
1198 *real_type_found
= 1;
1199 result
= value_enclosing_type (value
);
1207 error_value_optimized_out (void)
1209 error (_("value has been optimized out"));
1213 require_not_optimized_out (const struct value
*value
)
1215 if (!value
->optimized_out
.empty ())
1217 if (value
->lval
== lval_register
)
1218 error (_("register has not been saved in frame"));
1220 error_value_optimized_out ();
1225 require_available (const struct value
*value
)
1227 if (!value
->unavailable
.empty ())
1228 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1232 value_contents_for_printing (struct value
*value
)
1235 value_fetch_lazy (value
);
1236 return value
->contents
.get ();
1240 value_contents_for_printing_const (const struct value
*value
)
1242 gdb_assert (!value
->lazy
);
1243 return value
->contents
.get ();
1247 value_contents_all (struct value
*value
)
1249 const gdb_byte
*result
= value_contents_for_printing (value
);
1250 require_not_optimized_out (value
);
1251 require_available (value
);
1255 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1256 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1259 ranges_copy_adjusted (std::vector
<range
> *dst_range
, int dst_bit_offset
,
1260 const std::vector
<range
> &src_range
, int src_bit_offset
,
1263 for (const range
&r
: src_range
)
1267 l
= std::max (r
.offset
, (LONGEST
) src_bit_offset
);
1268 h
= std::min (r
.offset
+ r
.length
,
1269 (LONGEST
) src_bit_offset
+ bit_length
);
1272 insert_into_bit_range_vector (dst_range
,
1273 dst_bit_offset
+ (l
- src_bit_offset
),
1278 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1279 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1282 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1283 const struct value
*src
, int src_bit_offset
,
1286 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1287 src
->unavailable
, src_bit_offset
,
1289 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1290 src
->optimized_out
, src_bit_offset
,
1294 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1295 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1296 contents, starting at DST_OFFSET. If unavailable contents are
1297 being copied from SRC, the corresponding DST contents are marked
1298 unavailable accordingly. Neither DST nor SRC may be lazy
1301 It is assumed the contents of DST in the [DST_OFFSET,
1302 DST_OFFSET+LENGTH) range are wholly available. */
1305 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1306 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1308 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1309 struct gdbarch
*arch
= get_value_arch (src
);
1310 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1312 /* A lazy DST would make that this copy operation useless, since as
1313 soon as DST's contents were un-lazied (by a later value_contents
1314 call, say), the contents would be overwritten. A lazy SRC would
1315 mean we'd be copying garbage. */
1316 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1318 /* The overwritten DST range gets unavailability ORed in, not
1319 replaced. Make sure to remember to implement replacing if it
1320 turns out actually necessary. */
1321 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1322 gdb_assert (!value_bits_any_optimized_out (dst
,
1323 TARGET_CHAR_BIT
* dst_offset
,
1324 TARGET_CHAR_BIT
* length
));
1326 /* Copy the data. */
1327 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1328 value_contents_all_raw (src
) + src_offset
* unit_size
,
1329 length
* unit_size
);
1331 /* Copy the meta-data, adjusted. */
1332 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1333 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1334 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1336 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1337 src
, src_bit_offset
,
1341 /* Copy LENGTH bytes of SRC value's (all) contents
1342 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1343 (all) contents, starting at DST_OFFSET. If unavailable contents
1344 are being copied from SRC, the corresponding DST contents are
1345 marked unavailable accordingly. DST must not be lazy. If SRC is
1346 lazy, it will be fetched now.
1348 It is assumed the contents of DST in the [DST_OFFSET,
1349 DST_OFFSET+LENGTH) range are wholly available. */
1352 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1353 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1356 value_fetch_lazy (src
);
1358 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1362 value_lazy (const struct value
*value
)
1368 set_value_lazy (struct value
*value
, int val
)
1374 value_stack (const struct value
*value
)
1376 return value
->stack
;
1380 set_value_stack (struct value
*value
, int val
)
1386 value_contents (struct value
*value
)
1388 const gdb_byte
*result
= value_contents_writeable (value
);
1389 require_not_optimized_out (value
);
1390 require_available (value
);
1395 value_contents_writeable (struct value
*value
)
1398 value_fetch_lazy (value
);
1399 return value_contents_raw (value
);
1403 value_optimized_out (struct value
*value
)
1405 /* We can only know if a value is optimized out once we have tried to
1407 if (value
->optimized_out
.empty () && value
->lazy
)
1411 value_fetch_lazy (value
);
1413 catch (const gdb_exception_error
&ex
)
1415 /* Fall back to checking value->optimized_out. */
1419 return !value
->optimized_out
.empty ();
1422 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1423 the following LENGTH bytes. */
1426 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1428 mark_value_bits_optimized_out (value
,
1429 offset
* TARGET_CHAR_BIT
,
1430 length
* TARGET_CHAR_BIT
);
1436 mark_value_bits_optimized_out (struct value
*value
,
1437 LONGEST offset
, LONGEST length
)
1439 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1443 value_bits_synthetic_pointer (const struct value
*value
,
1444 LONGEST offset
, LONGEST length
)
1446 if (value
->lval
!= lval_computed
1447 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1449 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1455 value_embedded_offset (const struct value
*value
)
1457 return value
->embedded_offset
;
1461 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1463 value
->embedded_offset
= val
;
1467 value_pointed_to_offset (const struct value
*value
)
1469 return value
->pointed_to_offset
;
1473 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1475 value
->pointed_to_offset
= val
;
1478 const struct lval_funcs
*
1479 value_computed_funcs (const struct value
*v
)
1481 gdb_assert (value_lval_const (v
) == lval_computed
);
1483 return v
->location
.computed
.funcs
;
1487 value_computed_closure (const struct value
*v
)
1489 gdb_assert (v
->lval
== lval_computed
);
1491 return v
->location
.computed
.closure
;
1495 deprecated_value_lval_hack (struct value
*value
)
1497 return &value
->lval
;
1501 value_lval_const (const struct value
*value
)
1507 value_address (const struct value
*value
)
1509 if (value
->lval
!= lval_memory
)
1511 if (value
->parent
!= NULL
)
1512 return value_address (value
->parent
.get ()) + value
->offset
;
1513 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1515 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1516 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1519 return value
->location
.address
+ value
->offset
;
1523 value_raw_address (const struct value
*value
)
1525 if (value
->lval
!= lval_memory
)
1527 return value
->location
.address
;
1531 set_value_address (struct value
*value
, CORE_ADDR addr
)
1533 gdb_assert (value
->lval
== lval_memory
);
1534 value
->location
.address
= addr
;
1537 struct internalvar
**
1538 deprecated_value_internalvar_hack (struct value
*value
)
1540 return &value
->location
.internalvar
;
1544 deprecated_value_next_frame_id_hack (struct value
*value
)
1546 gdb_assert (value
->lval
== lval_register
);
1547 return &value
->location
.reg
.next_frame_id
;
1551 deprecated_value_regnum_hack (struct value
*value
)
1553 gdb_assert (value
->lval
== lval_register
);
1554 return &value
->location
.reg
.regnum
;
1558 deprecated_value_modifiable (const struct value
*value
)
1560 return value
->modifiable
;
1563 /* Return a mark in the value chain. All values allocated after the
1564 mark is obtained (except for those released) are subject to being freed
1565 if a subsequent value_free_to_mark is passed the mark. */
1569 if (all_values
.empty ())
1571 return all_values
.back ().get ();
1577 value_incref (struct value
*val
)
1579 val
->reference_count
++;
1582 /* Release a reference to VAL, which was acquired with value_incref.
1583 This function is also called to deallocate values from the value
1587 value_decref (struct value
*val
)
1591 gdb_assert (val
->reference_count
> 0);
1592 val
->reference_count
--;
1593 if (val
->reference_count
== 0)
1598 /* Free all values allocated since MARK was obtained by value_mark
1599 (except for those released). */
1601 value_free_to_mark (const struct value
*mark
)
1603 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1604 if (iter
== all_values
.end ())
1605 all_values
.clear ();
1607 all_values
.erase (iter
+ 1, all_values
.end ());
1610 /* Remove VAL from the chain all_values
1611 so it will not be freed automatically. */
1614 release_value (struct value
*val
)
1617 return value_ref_ptr ();
1619 std::vector
<value_ref_ptr
>::reverse_iterator iter
;
1620 for (iter
= all_values
.rbegin (); iter
!= all_values
.rend (); ++iter
)
1624 value_ref_ptr result
= *iter
;
1625 all_values
.erase (iter
.base () - 1);
1630 /* We must always return an owned reference. Normally this happens
1631 because we transfer the reference from the value chain, but in
1632 this case the value was not on the chain. */
1633 return value_ref_ptr::new_reference (val
);
1638 std::vector
<value_ref_ptr
>
1639 value_release_to_mark (const struct value
*mark
)
1641 std::vector
<value_ref_ptr
> result
;
1643 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1644 if (iter
== all_values
.end ())
1645 std::swap (result
, all_values
);
1648 std::move (iter
+ 1, all_values
.end (), std::back_inserter (result
));
1649 all_values
.erase (iter
+ 1, all_values
.end ());
1651 std::reverse (result
.begin (), result
.end ());
1655 /* Return a copy of the value ARG.
1656 It contains the same contents, for same memory address,
1657 but it's a different block of storage. */
1660 value_copy (struct value
*arg
)
1662 struct type
*encl_type
= value_enclosing_type (arg
);
1665 if (value_lazy (arg
))
1666 val
= allocate_value_lazy (encl_type
);
1668 val
= allocate_value (encl_type
);
1669 val
->type
= arg
->type
;
1670 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1671 val
->location
= arg
->location
;
1672 val
->offset
= arg
->offset
;
1673 val
->bitpos
= arg
->bitpos
;
1674 val
->bitsize
= arg
->bitsize
;
1675 val
->lazy
= arg
->lazy
;
1676 val
->embedded_offset
= value_embedded_offset (arg
);
1677 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1678 val
->modifiable
= arg
->modifiable
;
1679 if (!value_lazy (val
))
1681 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1682 TYPE_LENGTH (value_enclosing_type (arg
)));
1685 val
->unavailable
= arg
->unavailable
;
1686 val
->optimized_out
= arg
->optimized_out
;
1687 val
->parent
= arg
->parent
;
1688 if (VALUE_LVAL (val
) == lval_computed
)
1690 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1692 if (funcs
->copy_closure
)
1693 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1698 /* Return a "const" and/or "volatile" qualified version of the value V.
1699 If CNST is true, then the returned value will be qualified with
1701 if VOLTL is true, then the returned value will be qualified with
1705 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1707 struct type
*val_type
= value_type (v
);
1708 struct type
*enclosing_type
= value_enclosing_type (v
);
1709 struct value
*cv_val
= value_copy (v
);
1711 deprecated_set_value_type (cv_val
,
1712 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1713 set_value_enclosing_type (cv_val
,
1714 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1719 /* Return a version of ARG that is non-lvalue. */
1722 value_non_lval (struct value
*arg
)
1724 if (VALUE_LVAL (arg
) != not_lval
)
1726 struct type
*enc_type
= value_enclosing_type (arg
);
1727 struct value
*val
= allocate_value (enc_type
);
1729 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1730 TYPE_LENGTH (enc_type
));
1731 val
->type
= arg
->type
;
1732 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1733 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1739 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1742 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1744 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1746 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1747 v
->lval
= lval_memory
;
1748 v
->location
.address
= addr
;
1752 set_value_component_location (struct value
*component
,
1753 const struct value
*whole
)
1757 gdb_assert (whole
->lval
!= lval_xcallable
);
1759 if (whole
->lval
== lval_internalvar
)
1760 VALUE_LVAL (component
) = lval_internalvar_component
;
1762 VALUE_LVAL (component
) = whole
->lval
;
1764 component
->location
= whole
->location
;
1765 if (whole
->lval
== lval_computed
)
1767 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1769 if (funcs
->copy_closure
)
1770 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1773 /* If type has a dynamic resolved location property
1774 update it's value address. */
1775 type
= value_type (whole
);
1776 if (NULL
!= TYPE_DATA_LOCATION (type
)
1777 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1778 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1781 /* Access to the value history. */
1783 /* Record a new value in the value history.
1784 Returns the absolute history index of the entry. */
1787 record_latest_value (struct value
*val
)
1789 /* We don't want this value to have anything to do with the inferior anymore.
1790 In particular, "set $1 = 50" should not affect the variable from which
1791 the value was taken, and fast watchpoints should be able to assume that
1792 a value on the value history never changes. */
1793 if (value_lazy (val
))
1794 value_fetch_lazy (val
);
1795 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1796 from. This is a bit dubious, because then *&$1 does not just return $1
1797 but the current contents of that location. c'est la vie... */
1798 val
->modifiable
= 0;
1800 value_history
.push_back (release_value (val
));
1802 return value_history
.size ();
1805 /* Return a copy of the value in the history with sequence number NUM. */
1808 access_value_history (int num
)
1813 absnum
+= value_history
.size ();
1818 error (_("The history is empty."));
1820 error (_("There is only one value in the history."));
1822 error (_("History does not go back to $$%d."), -num
);
1824 if (absnum
> value_history
.size ())
1825 error (_("History has not yet reached $%d."), absnum
);
1829 return value_copy (value_history
[absnum
].get ());
1833 show_values (const char *num_exp
, int from_tty
)
1841 /* "show values +" should print from the stored position.
1842 "show values <exp>" should print around value number <exp>. */
1843 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1844 num
= parse_and_eval_long (num_exp
) - 5;
1848 /* "show values" means print the last 10 values. */
1849 num
= value_history
.size () - 9;
1855 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1857 struct value_print_options opts
;
1859 val
= access_value_history (i
);
1860 printf_filtered (("$%d = "), i
);
1861 get_user_print_options (&opts
);
1862 value_print (val
, gdb_stdout
, &opts
);
1863 printf_filtered (("\n"));
1866 /* The next "show values +" should start after what we just printed. */
1869 /* Hitting just return after this command should do the same thing as
1870 "show values +". If num_exp is null, this is unnecessary, since
1871 "show values +" is not useful after "show values". */
1872 if (from_tty
&& num_exp
)
1873 set_repeat_arguments ("+");
1876 enum internalvar_kind
1878 /* The internal variable is empty. */
1881 /* The value of the internal variable is provided directly as
1882 a GDB value object. */
1885 /* A fresh value is computed via a call-back routine on every
1886 access to the internal variable. */
1887 INTERNALVAR_MAKE_VALUE
,
1889 /* The internal variable holds a GDB internal convenience function. */
1890 INTERNALVAR_FUNCTION
,
1892 /* The variable holds an integer value. */
1893 INTERNALVAR_INTEGER
,
1895 /* The variable holds a GDB-provided string. */
1899 union internalvar_data
1901 /* A value object used with INTERNALVAR_VALUE. */
1902 struct value
*value
;
1904 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1907 /* The functions to call. */
1908 const struct internalvar_funcs
*functions
;
1910 /* The function's user-data. */
1914 /* The internal function used with INTERNALVAR_FUNCTION. */
1917 struct internal_function
*function
;
1918 /* True if this is the canonical name for the function. */
1922 /* An integer value used with INTERNALVAR_INTEGER. */
1925 /* If type is non-NULL, it will be used as the type to generate
1926 a value for this internal variable. If type is NULL, a default
1927 integer type for the architecture is used. */
1932 /* A string value used with INTERNALVAR_STRING. */
1936 /* Internal variables. These are variables within the debugger
1937 that hold values assigned by debugger commands.
1938 The user refers to them with a '$' prefix
1939 that does not appear in the variable names stored internally. */
1943 struct internalvar
*next
;
1946 /* We support various different kinds of content of an internal variable.
1947 enum internalvar_kind specifies the kind, and union internalvar_data
1948 provides the data associated with this particular kind. */
1950 enum internalvar_kind kind
;
1952 union internalvar_data u
;
1955 static struct internalvar
*internalvars
;
1957 /* If the variable does not already exist create it and give it the
1958 value given. If no value is given then the default is zero. */
1960 init_if_undefined_command (const char* args
, int from_tty
)
1962 struct internalvar
* intvar
;
1964 /* Parse the expression - this is taken from set_command(). */
1965 expression_up expr
= parse_expression (args
);
1967 /* Validate the expression.
1968 Was the expression an assignment?
1969 Or even an expression at all? */
1970 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1971 error (_("Init-if-undefined requires an assignment expression."));
1973 /* Extract the variable from the parsed expression.
1974 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1975 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1976 error (_("The first parameter to init-if-undefined "
1977 "should be a GDB variable."));
1978 intvar
= expr
->elts
[2].internalvar
;
1980 /* Only evaluate the expression if the lvalue is void.
1981 This may still fail if the expression is invalid. */
1982 if (intvar
->kind
== INTERNALVAR_VOID
)
1983 evaluate_expression (expr
.get ());
1987 /* Look up an internal variable with name NAME. NAME should not
1988 normally include a dollar sign.
1990 If the specified internal variable does not exist,
1991 the return value is NULL. */
1993 struct internalvar
*
1994 lookup_only_internalvar (const char *name
)
1996 struct internalvar
*var
;
1998 for (var
= internalvars
; var
; var
= var
->next
)
1999 if (strcmp (var
->name
, name
) == 0)
2005 /* Complete NAME by comparing it to the names of internal
2009 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2011 struct internalvar
*var
;
2014 len
= strlen (name
);
2016 for (var
= internalvars
; var
; var
= var
->next
)
2017 if (strncmp (var
->name
, name
, len
) == 0)
2018 tracker
.add_completion (make_unique_xstrdup (var
->name
));
2021 /* Create an internal variable with name NAME and with a void value.
2022 NAME should not normally include a dollar sign. */
2024 struct internalvar
*
2025 create_internalvar (const char *name
)
2027 struct internalvar
*var
= XNEW (struct internalvar
);
2029 var
->name
= xstrdup (name
);
2030 var
->kind
= INTERNALVAR_VOID
;
2031 var
->next
= internalvars
;
2036 /* Create an internal variable with name NAME and register FUN as the
2037 function that value_of_internalvar uses to create a value whenever
2038 this variable is referenced. NAME should not normally include a
2039 dollar sign. DATA is passed uninterpreted to FUN when it is
2040 called. CLEANUP, if not NULL, is called when the internal variable
2041 is destroyed. It is passed DATA as its only argument. */
2043 struct internalvar
*
2044 create_internalvar_type_lazy (const char *name
,
2045 const struct internalvar_funcs
*funcs
,
2048 struct internalvar
*var
= create_internalvar (name
);
2050 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2051 var
->u
.make_value
.functions
= funcs
;
2052 var
->u
.make_value
.data
= data
;
2056 /* See documentation in value.h. */
2059 compile_internalvar_to_ax (struct internalvar
*var
,
2060 struct agent_expr
*expr
,
2061 struct axs_value
*value
)
2063 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2064 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2067 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2068 var
->u
.make_value
.data
);
2072 /* Look up an internal variable with name NAME. NAME should not
2073 normally include a dollar sign.
2075 If the specified internal variable does not exist,
2076 one is created, with a void value. */
2078 struct internalvar
*
2079 lookup_internalvar (const char *name
)
2081 struct internalvar
*var
;
2083 var
= lookup_only_internalvar (name
);
2087 return create_internalvar (name
);
2090 /* Return current value of internal variable VAR. For variables that
2091 are not inherently typed, use a value type appropriate for GDBARCH. */
2094 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2097 struct trace_state_variable
*tsv
;
2099 /* If there is a trace state variable of the same name, assume that
2100 is what we really want to see. */
2101 tsv
= find_trace_state_variable (var
->name
);
2104 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2106 if (tsv
->value_known
)
2107 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2110 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2116 case INTERNALVAR_VOID
:
2117 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2120 case INTERNALVAR_FUNCTION
:
2121 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2124 case INTERNALVAR_INTEGER
:
2125 if (!var
->u
.integer
.type
)
2126 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2127 var
->u
.integer
.val
);
2129 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2132 case INTERNALVAR_STRING
:
2133 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2134 builtin_type (gdbarch
)->builtin_char
);
2137 case INTERNALVAR_VALUE
:
2138 val
= value_copy (var
->u
.value
);
2139 if (value_lazy (val
))
2140 value_fetch_lazy (val
);
2143 case INTERNALVAR_MAKE_VALUE
:
2144 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2145 var
->u
.make_value
.data
);
2149 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2152 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2153 on this value go back to affect the original internal variable.
2155 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2156 no underlying modifiable state in the internal variable.
2158 Likewise, if the variable's value is a computed lvalue, we want
2159 references to it to produce another computed lvalue, where
2160 references and assignments actually operate through the
2161 computed value's functions.
2163 This means that internal variables with computed values
2164 behave a little differently from other internal variables:
2165 assignments to them don't just replace the previous value
2166 altogether. At the moment, this seems like the behavior we
2169 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2170 && val
->lval
!= lval_computed
)
2172 VALUE_LVAL (val
) = lval_internalvar
;
2173 VALUE_INTERNALVAR (val
) = var
;
2180 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2182 if (var
->kind
== INTERNALVAR_INTEGER
)
2184 *result
= var
->u
.integer
.val
;
2188 if (var
->kind
== INTERNALVAR_VALUE
)
2190 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2192 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2194 *result
= value_as_long (var
->u
.value
);
2203 get_internalvar_function (struct internalvar
*var
,
2204 struct internal_function
**result
)
2208 case INTERNALVAR_FUNCTION
:
2209 *result
= var
->u
.fn
.function
;
2218 set_internalvar_component (struct internalvar
*var
,
2219 LONGEST offset
, LONGEST bitpos
,
2220 LONGEST bitsize
, struct value
*newval
)
2223 struct gdbarch
*arch
;
2228 case INTERNALVAR_VALUE
:
2229 addr
= value_contents_writeable (var
->u
.value
);
2230 arch
= get_value_arch (var
->u
.value
);
2231 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2234 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2235 value_as_long (newval
), bitpos
, bitsize
);
2237 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2238 TYPE_LENGTH (value_type (newval
)));
2242 /* We can never get a component of any other kind. */
2243 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2248 set_internalvar (struct internalvar
*var
, struct value
*val
)
2250 enum internalvar_kind new_kind
;
2251 union internalvar_data new_data
= { 0 };
2253 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2254 error (_("Cannot overwrite convenience function %s"), var
->name
);
2256 /* Prepare new contents. */
2257 switch (TYPE_CODE (check_typedef (value_type (val
))))
2259 case TYPE_CODE_VOID
:
2260 new_kind
= INTERNALVAR_VOID
;
2263 case TYPE_CODE_INTERNAL_FUNCTION
:
2264 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2265 new_kind
= INTERNALVAR_FUNCTION
;
2266 get_internalvar_function (VALUE_INTERNALVAR (val
),
2267 &new_data
.fn
.function
);
2268 /* Copies created here are never canonical. */
2272 new_kind
= INTERNALVAR_VALUE
;
2273 struct value
*copy
= value_copy (val
);
2274 copy
->modifiable
= 1;
2276 /* Force the value to be fetched from the target now, to avoid problems
2277 later when this internalvar is referenced and the target is gone or
2279 if (value_lazy (copy
))
2280 value_fetch_lazy (copy
);
2282 /* Release the value from the value chain to prevent it from being
2283 deleted by free_all_values. From here on this function should not
2284 call error () until new_data is installed into the var->u to avoid
2286 new_data
.value
= release_value (copy
).release ();
2288 /* Internal variables which are created from values with a dynamic
2289 location don't need the location property of the origin anymore.
2290 The resolved dynamic location is used prior then any other address
2291 when accessing the value.
2292 If we keep it, we would still refer to the origin value.
2293 Remove the location property in case it exist. */
2294 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2299 /* Clean up old contents. */
2300 clear_internalvar (var
);
2303 var
->kind
= new_kind
;
2305 /* End code which must not call error(). */
2309 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2311 /* Clean up old contents. */
2312 clear_internalvar (var
);
2314 var
->kind
= INTERNALVAR_INTEGER
;
2315 var
->u
.integer
.type
= NULL
;
2316 var
->u
.integer
.val
= l
;
2320 set_internalvar_string (struct internalvar
*var
, const char *string
)
2322 /* Clean up old contents. */
2323 clear_internalvar (var
);
2325 var
->kind
= INTERNALVAR_STRING
;
2326 var
->u
.string
= xstrdup (string
);
2330 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2332 /* Clean up old contents. */
2333 clear_internalvar (var
);
2335 var
->kind
= INTERNALVAR_FUNCTION
;
2336 var
->u
.fn
.function
= f
;
2337 var
->u
.fn
.canonical
= 1;
2338 /* Variables installed here are always the canonical version. */
2342 clear_internalvar (struct internalvar
*var
)
2344 /* Clean up old contents. */
2347 case INTERNALVAR_VALUE
:
2348 value_decref (var
->u
.value
);
2351 case INTERNALVAR_STRING
:
2352 xfree (var
->u
.string
);
2355 case INTERNALVAR_MAKE_VALUE
:
2356 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2357 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2364 /* Reset to void kind. */
2365 var
->kind
= INTERNALVAR_VOID
;
2369 internalvar_name (const struct internalvar
*var
)
2374 static struct internal_function
*
2375 create_internal_function (const char *name
,
2376 internal_function_fn handler
, void *cookie
)
2378 struct internal_function
*ifn
= XNEW (struct internal_function
);
2380 ifn
->name
= xstrdup (name
);
2381 ifn
->handler
= handler
;
2382 ifn
->cookie
= cookie
;
2387 value_internal_function_name (struct value
*val
)
2389 struct internal_function
*ifn
;
2392 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2393 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2394 gdb_assert (result
);
2400 call_internal_function (struct gdbarch
*gdbarch
,
2401 const struct language_defn
*language
,
2402 struct value
*func
, int argc
, struct value
**argv
)
2404 struct internal_function
*ifn
;
2407 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2408 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2409 gdb_assert (result
);
2411 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2414 /* The 'function' command. This does nothing -- it is just a
2415 placeholder to let "help function NAME" work. This is also used as
2416 the implementation of the sub-command that is created when
2417 registering an internal function. */
2419 function_command (const char *command
, int from_tty
)
2424 /* Clean up if an internal function's command is destroyed. */
2426 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2428 xfree ((char *) self
->name
);
2429 xfree ((char *) self
->doc
);
2432 /* Add a new internal function. NAME is the name of the function; DOC
2433 is a documentation string describing the function. HANDLER is
2434 called when the function is invoked. COOKIE is an arbitrary
2435 pointer which is passed to HANDLER and is intended for "user
2438 add_internal_function (const char *name
, const char *doc
,
2439 internal_function_fn handler
, void *cookie
)
2441 struct cmd_list_element
*cmd
;
2442 struct internal_function
*ifn
;
2443 struct internalvar
*var
= lookup_internalvar (name
);
2445 ifn
= create_internal_function (name
, handler
, cookie
);
2446 set_internalvar_function (var
, ifn
);
2448 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2450 cmd
->destroyer
= function_destroyer
;
2453 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2454 prevent cycles / duplicates. */
2457 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2458 htab_t copied_types
)
2460 if (TYPE_OBJFILE (value
->type
) == objfile
)
2461 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2463 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2464 value
->enclosing_type
= copy_type_recursive (objfile
,
2465 value
->enclosing_type
,
2469 /* Likewise for internal variable VAR. */
2472 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2473 htab_t copied_types
)
2477 case INTERNALVAR_INTEGER
:
2478 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2480 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2483 case INTERNALVAR_VALUE
:
2484 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2489 /* Update the internal variables and value history when OBJFILE is
2490 discarded; we must copy the types out of the objfile. New global types
2491 will be created for every convenience variable which currently points to
2492 this objfile's types, and the convenience variables will be adjusted to
2493 use the new global types. */
2496 preserve_values (struct objfile
*objfile
)
2498 htab_t copied_types
;
2499 struct internalvar
*var
;
2501 /* Create the hash table. We allocate on the objfile's obstack, since
2502 it is soon to be deleted. */
2503 copied_types
= create_copied_types_hash (objfile
);
2505 for (const value_ref_ptr
&item
: value_history
)
2506 preserve_one_value (item
.get (), objfile
, copied_types
);
2508 for (var
= internalvars
; var
; var
= var
->next
)
2509 preserve_one_internalvar (var
, objfile
, copied_types
);
2511 preserve_ext_lang_values (objfile
, copied_types
);
2513 htab_delete (copied_types
);
2517 show_convenience (const char *ignore
, int from_tty
)
2519 struct gdbarch
*gdbarch
= get_current_arch ();
2520 struct internalvar
*var
;
2522 struct value_print_options opts
;
2524 get_user_print_options (&opts
);
2525 for (var
= internalvars
; var
; var
= var
->next
)
2532 printf_filtered (("$%s = "), var
->name
);
2538 val
= value_of_internalvar (gdbarch
, var
);
2539 value_print (val
, gdb_stdout
, &opts
);
2541 catch (const gdb_exception_error
&ex
)
2543 fprintf_styled (gdb_stdout
, metadata_style
.style (),
2544 _("<error: %s>"), ex
.what ());
2547 printf_filtered (("\n"));
2551 /* This text does not mention convenience functions on purpose.
2552 The user can't create them except via Python, and if Python support
2553 is installed this message will never be printed ($_streq will
2555 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2556 "Convenience variables have "
2557 "names starting with \"$\";\n"
2558 "use \"set\" as in \"set "
2559 "$foo = 5\" to define them.\n"));
2567 value_from_xmethod (xmethod_worker_up
&&worker
)
2571 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2572 v
->lval
= lval_xcallable
;
2573 v
->location
.xm_worker
= worker
.release ();
2579 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2582 result_type_of_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2584 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2585 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2587 return method
->location
.xm_worker
->get_result_type (argv
[0], argv
.slice (1));
2590 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2593 call_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2595 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2596 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2598 return method
->location
.xm_worker
->invoke (argv
[0], argv
.slice (1));
2601 /* Extract a value as a C number (either long or double).
2602 Knows how to convert fixed values to double, or
2603 floating values to long.
2604 Does not deallocate the value. */
2607 value_as_long (struct value
*val
)
2609 /* This coerces arrays and functions, which is necessary (e.g.
2610 in disassemble_command). It also dereferences references, which
2611 I suspect is the most logical thing to do. */
2612 val
= coerce_array (val
);
2613 return unpack_long (value_type (val
), value_contents (val
));
2616 /* Extract a value as a C pointer. Does not deallocate the value.
2617 Note that val's type may not actually be a pointer; value_as_long
2618 handles all the cases. */
2620 value_as_address (struct value
*val
)
2622 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2624 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2625 whether we want this to be true eventually. */
2627 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2628 non-address (e.g. argument to "signal", "info break", etc.), or
2629 for pointers to char, in which the low bits *are* significant. */
2630 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2633 /* There are several targets (IA-64, PowerPC, and others) which
2634 don't represent pointers to functions as simply the address of
2635 the function's entry point. For example, on the IA-64, a
2636 function pointer points to a two-word descriptor, generated by
2637 the linker, which contains the function's entry point, and the
2638 value the IA-64 "global pointer" register should have --- to
2639 support position-independent code. The linker generates
2640 descriptors only for those functions whose addresses are taken.
2642 On such targets, it's difficult for GDB to convert an arbitrary
2643 function address into a function pointer; it has to either find
2644 an existing descriptor for that function, or call malloc and
2645 build its own. On some targets, it is impossible for GDB to
2646 build a descriptor at all: the descriptor must contain a jump
2647 instruction; data memory cannot be executed; and code memory
2650 Upon entry to this function, if VAL is a value of type `function'
2651 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2652 value_address (val) is the address of the function. This is what
2653 you'll get if you evaluate an expression like `main'. The call
2654 to COERCE_ARRAY below actually does all the usual unary
2655 conversions, which includes converting values of type `function'
2656 to `pointer to function'. This is the challenging conversion
2657 discussed above. Then, `unpack_long' will convert that pointer
2658 back into an address.
2660 So, suppose the user types `disassemble foo' on an architecture
2661 with a strange function pointer representation, on which GDB
2662 cannot build its own descriptors, and suppose further that `foo'
2663 has no linker-built descriptor. The address->pointer conversion
2664 will signal an error and prevent the command from running, even
2665 though the next step would have been to convert the pointer
2666 directly back into the same address.
2668 The following shortcut avoids this whole mess. If VAL is a
2669 function, just return its address directly. */
2670 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2671 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2672 return value_address (val
);
2674 val
= coerce_array (val
);
2676 /* Some architectures (e.g. Harvard), map instruction and data
2677 addresses onto a single large unified address space. For
2678 instance: An architecture may consider a large integer in the
2679 range 0x10000000 .. 0x1000ffff to already represent a data
2680 addresses (hence not need a pointer to address conversion) while
2681 a small integer would still need to be converted integer to
2682 pointer to address. Just assume such architectures handle all
2683 integer conversions in a single function. */
2687 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2688 must admonish GDB hackers to make sure its behavior matches the
2689 compiler's, whenever possible.
2691 In general, I think GDB should evaluate expressions the same way
2692 the compiler does. When the user copies an expression out of
2693 their source code and hands it to a `print' command, they should
2694 get the same value the compiler would have computed. Any
2695 deviation from this rule can cause major confusion and annoyance,
2696 and needs to be justified carefully. In other words, GDB doesn't
2697 really have the freedom to do these conversions in clever and
2700 AndrewC pointed out that users aren't complaining about how GDB
2701 casts integers to pointers; they are complaining that they can't
2702 take an address from a disassembly listing and give it to `x/i'.
2703 This is certainly important.
2705 Adding an architecture method like integer_to_address() certainly
2706 makes it possible for GDB to "get it right" in all circumstances
2707 --- the target has complete control over how things get done, so
2708 people can Do The Right Thing for their target without breaking
2709 anyone else. The standard doesn't specify how integers get
2710 converted to pointers; usually, the ABI doesn't either, but
2711 ABI-specific code is a more reasonable place to handle it. */
2713 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2714 && !TYPE_IS_REFERENCE (value_type (val
))
2715 && gdbarch_integer_to_address_p (gdbarch
))
2716 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2717 value_contents (val
));
2719 return unpack_long (value_type (val
), value_contents (val
));
2723 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2724 as a long, or as a double, assuming the raw data is described
2725 by type TYPE. Knows how to convert different sizes of values
2726 and can convert between fixed and floating point. We don't assume
2727 any alignment for the raw data. Return value is in host byte order.
2729 If you want functions and arrays to be coerced to pointers, and
2730 references to be dereferenced, call value_as_long() instead.
2732 C++: It is assumed that the front-end has taken care of
2733 all matters concerning pointers to members. A pointer
2734 to member which reaches here is considered to be equivalent
2735 to an INT (or some size). After all, it is only an offset. */
2738 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2740 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2741 enum type_code code
= TYPE_CODE (type
);
2742 int len
= TYPE_LENGTH (type
);
2743 int nosign
= TYPE_UNSIGNED (type
);
2747 case TYPE_CODE_TYPEDEF
:
2748 return unpack_long (check_typedef (type
), valaddr
);
2749 case TYPE_CODE_ENUM
:
2750 case TYPE_CODE_FLAGS
:
2751 case TYPE_CODE_BOOL
:
2753 case TYPE_CODE_CHAR
:
2754 case TYPE_CODE_RANGE
:
2755 case TYPE_CODE_MEMBERPTR
:
2759 result
= extract_unsigned_integer (valaddr
, len
, byte_order
);
2761 result
= extract_signed_integer (valaddr
, len
, byte_order
);
2762 if (code
== TYPE_CODE_RANGE
)
2763 result
+= TYPE_RANGE_DATA (type
)->bias
;
2768 case TYPE_CODE_DECFLOAT
:
2769 return target_float_to_longest (valaddr
, type
);
2773 case TYPE_CODE_RVALUE_REF
:
2774 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2775 whether we want this to be true eventually. */
2776 return extract_typed_address (valaddr
, type
);
2779 error (_("Value can't be converted to integer."));
2783 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2784 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2785 We don't assume any alignment for the raw data. Return value is in
2788 If you want functions and arrays to be coerced to pointers, and
2789 references to be dereferenced, call value_as_address() instead.
2791 C++: It is assumed that the front-end has taken care of
2792 all matters concerning pointers to members. A pointer
2793 to member which reaches here is considered to be equivalent
2794 to an INT (or some size). After all, it is only an offset. */
2797 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2799 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2800 whether we want this to be true eventually. */
2801 return unpack_long (type
, valaddr
);
2805 is_floating_value (struct value
*val
)
2807 struct type
*type
= check_typedef (value_type (val
));
2809 if (is_floating_type (type
))
2811 if (!target_float_is_valid (value_contents (val
), type
))
2812 error (_("Invalid floating value found in program."));
2820 /* Get the value of the FIELDNO'th field (which must be static) of
2824 value_static_field (struct type
*type
, int fieldno
)
2826 struct value
*retval
;
2828 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2830 case FIELD_LOC_KIND_PHYSADDR
:
2831 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2832 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2834 case FIELD_LOC_KIND_PHYSNAME
:
2836 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2837 /* TYPE_FIELD_NAME (type, fieldno); */
2838 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2840 if (sym
.symbol
== NULL
)
2842 /* With some compilers, e.g. HP aCC, static data members are
2843 reported as non-debuggable symbols. */
2844 struct bound_minimal_symbol msym
2845 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2846 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2849 retval
= allocate_optimized_out_value (field_type
);
2851 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2854 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2858 gdb_assert_not_reached ("unexpected field location kind");
2864 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2865 You have to be careful here, since the size of the data area for the value
2866 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2867 than the old enclosing type, you have to allocate more space for the
2871 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2873 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2875 check_type_length_before_alloc (new_encl_type
);
2877 .reset ((gdb_byte
*) xrealloc (val
->contents
.release (),
2878 TYPE_LENGTH (new_encl_type
)));
2881 val
->enclosing_type
= new_encl_type
;
2884 /* Given a value ARG1 (offset by OFFSET bytes)
2885 of a struct or union type ARG_TYPE,
2886 extract and return the value of one of its (non-static) fields.
2887 FIELDNO says which field. */
2890 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2891 int fieldno
, struct type
*arg_type
)
2895 struct gdbarch
*arch
= get_value_arch (arg1
);
2896 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2898 arg_type
= check_typedef (arg_type
);
2899 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2901 /* Call check_typedef on our type to make sure that, if TYPE
2902 is a TYPE_CODE_TYPEDEF, its length is set to the length
2903 of the target type instead of zero. However, we do not
2904 replace the typedef type by the target type, because we want
2905 to keep the typedef in order to be able to print the type
2906 description correctly. */
2907 check_typedef (type
);
2909 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2911 /* Handle packed fields.
2913 Create a new value for the bitfield, with bitpos and bitsize
2914 set. If possible, arrange offset and bitpos so that we can
2915 do a single aligned read of the size of the containing type.
2916 Otherwise, adjust offset to the byte containing the first
2917 bit. Assume that the address, offset, and embedded offset
2918 are sufficiently aligned. */
2920 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2921 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2923 v
= allocate_value_lazy (type
);
2924 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2925 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2926 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2927 v
->bitpos
= bitpos
% container_bitsize
;
2929 v
->bitpos
= bitpos
% 8;
2930 v
->offset
= (value_embedded_offset (arg1
)
2932 + (bitpos
- v
->bitpos
) / 8);
2933 set_value_parent (v
, arg1
);
2934 if (!value_lazy (arg1
))
2935 value_fetch_lazy (v
);
2937 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2939 /* This field is actually a base subobject, so preserve the
2940 entire object's contents for later references to virtual
2944 /* Lazy register values with offsets are not supported. */
2945 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2946 value_fetch_lazy (arg1
);
2948 /* We special case virtual inheritance here because this
2949 requires access to the contents, which we would rather avoid
2950 for references to ordinary fields of unavailable values. */
2951 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2952 boffset
= baseclass_offset (arg_type
, fieldno
,
2953 value_contents (arg1
),
2954 value_embedded_offset (arg1
),
2955 value_address (arg1
),
2958 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2960 if (value_lazy (arg1
))
2961 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2964 v
= allocate_value (value_enclosing_type (arg1
));
2965 value_contents_copy_raw (v
, 0, arg1
, 0,
2966 TYPE_LENGTH (value_enclosing_type (arg1
)));
2969 v
->offset
= value_offset (arg1
);
2970 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2972 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2974 /* Field is a dynamic data member. */
2976 gdb_assert (0 == offset
);
2977 /* We expect an already resolved data location. */
2978 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
2979 /* For dynamic data types defer memory allocation
2980 until we actual access the value. */
2981 v
= allocate_value_lazy (type
);
2985 /* Plain old data member */
2986 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
2987 / (HOST_CHAR_BIT
* unit_size
));
2989 /* Lazy register values with offsets are not supported. */
2990 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2991 value_fetch_lazy (arg1
);
2993 if (value_lazy (arg1
))
2994 v
= allocate_value_lazy (type
);
2997 v
= allocate_value (type
);
2998 value_contents_copy_raw (v
, value_embedded_offset (v
),
2999 arg1
, value_embedded_offset (arg1
) + offset
,
3000 type_length_units (type
));
3002 v
->offset
= (value_offset (arg1
) + offset
3003 + value_embedded_offset (arg1
));
3005 set_value_component_location (v
, arg1
);
3009 /* Given a value ARG1 of a struct or union type,
3010 extract and return the value of one of its (non-static) fields.
3011 FIELDNO says which field. */
3014 value_field (struct value
*arg1
, int fieldno
)
3016 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3019 /* Return a non-virtual function as a value.
3020 F is the list of member functions which contains the desired method.
3021 J is an index into F which provides the desired method.
3023 We only use the symbol for its address, so be happy with either a
3024 full symbol or a minimal symbol. */
3027 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3028 int j
, struct type
*type
,
3032 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3033 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3035 struct bound_minimal_symbol msym
;
3037 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3040 memset (&msym
, 0, sizeof (msym
));
3044 gdb_assert (sym
== NULL
);
3045 msym
= lookup_bound_minimal_symbol (physname
);
3046 if (msym
.minsym
== NULL
)
3050 v
= allocate_value (ftype
);
3051 VALUE_LVAL (v
) = lval_memory
;
3054 set_value_address (v
, BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (sym
)));
3058 /* The minimal symbol might point to a function descriptor;
3059 resolve it to the actual code address instead. */
3060 struct objfile
*objfile
= msym
.objfile
;
3061 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3063 set_value_address (v
,
3064 gdbarch_convert_from_func_ptr_addr
3065 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), current_top_target ()));
3070 if (type
!= value_type (*arg1p
))
3071 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3072 value_addr (*arg1p
)));
3074 /* Move the `this' pointer according to the offset.
3075 VALUE_OFFSET (*arg1p) += offset; */
3083 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3084 VALADDR, and store the result in *RESULT.
3085 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3086 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3088 Extracting bits depends on endianness of the machine. Compute the
3089 number of least significant bits to discard. For big endian machines,
3090 we compute the total number of bits in the anonymous object, subtract
3091 off the bit count from the MSB of the object to the MSB of the
3092 bitfield, then the size of the bitfield, which leaves the LSB discard
3093 count. For little endian machines, the discard count is simply the
3094 number of bits from the LSB of the anonymous object to the LSB of the
3097 If the field is signed, we also do sign extension. */
3100 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3101 LONGEST bitpos
, LONGEST bitsize
)
3103 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3108 LONGEST read_offset
;
3110 /* Read the minimum number of bytes required; there may not be
3111 enough bytes to read an entire ULONGEST. */
3112 field_type
= check_typedef (field_type
);
3114 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3117 bytes_read
= TYPE_LENGTH (field_type
);
3118 bitsize
= 8 * bytes_read
;
3121 read_offset
= bitpos
/ 8;
3123 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3124 bytes_read
, byte_order
);
3126 /* Extract bits. See comment above. */
3128 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3129 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3131 lsbcount
= (bitpos
% 8);
3134 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3135 If the field is signed, and is negative, then sign extend. */
3137 if (bitsize
< 8 * (int) sizeof (val
))
3139 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3141 if (!TYPE_UNSIGNED (field_type
))
3143 if (val
& (valmask
^ (valmask
>> 1)))
3153 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3154 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3155 ORIGINAL_VALUE, which must not be NULL. See
3156 unpack_value_bits_as_long for more details. */
3159 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3160 LONGEST embedded_offset
, int fieldno
,
3161 const struct value
*val
, LONGEST
*result
)
3163 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3164 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3165 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3168 gdb_assert (val
!= NULL
);
3170 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3171 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3172 || !value_bits_available (val
, bit_offset
, bitsize
))
3175 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3180 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3181 object at VALADDR. See unpack_bits_as_long for more details. */
3184 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3186 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3187 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3188 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3190 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3193 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3194 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3195 the contents in DEST_VAL, zero or sign extending if the type of
3196 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3197 VAL. If the VAL's contents required to extract the bitfield from
3198 are unavailable/optimized out, DEST_VAL is correspondingly
3199 marked unavailable/optimized out. */
3202 unpack_value_bitfield (struct value
*dest_val
,
3203 LONGEST bitpos
, LONGEST bitsize
,
3204 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3205 const struct value
*val
)
3207 enum bfd_endian byte_order
;
3210 struct type
*field_type
= value_type (dest_val
);
3212 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3214 /* First, unpack and sign extend the bitfield as if it was wholly
3215 valid. Optimized out/unavailable bits are read as zero, but
3216 that's OK, as they'll end up marked below. If the VAL is
3217 wholly-invalid we may have skipped allocating its contents,
3218 though. See allocate_optimized_out_value. */
3219 if (valaddr
!= NULL
)
3223 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3225 store_signed_integer (value_contents_raw (dest_val
),
3226 TYPE_LENGTH (field_type
), byte_order
, num
);
3229 /* Now copy the optimized out / unavailability ranges to the right
3231 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3232 if (byte_order
== BFD_ENDIAN_BIG
)
3233 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3236 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3237 val
, src_bit_offset
, bitsize
);
3240 /* Return a new value with type TYPE, which is FIELDNO field of the
3241 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3242 of VAL. If the VAL's contents required to extract the bitfield
3243 from are unavailable/optimized out, the new value is
3244 correspondingly marked unavailable/optimized out. */
3247 value_field_bitfield (struct type
*type
, int fieldno
,
3248 const gdb_byte
*valaddr
,
3249 LONGEST embedded_offset
, const struct value
*val
)
3251 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3252 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3253 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3255 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3256 valaddr
, embedded_offset
, val
);
3261 /* Modify the value of a bitfield. ADDR points to a block of memory in
3262 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3263 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3264 indicate which bits (in target bit order) comprise the bitfield.
3265 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3266 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3269 modify_field (struct type
*type
, gdb_byte
*addr
,
3270 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3272 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3274 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3277 /* Normalize BITPOS. */
3281 /* If a negative fieldval fits in the field in question, chop
3282 off the sign extension bits. */
3283 if ((~fieldval
& ~(mask
>> 1)) == 0)
3286 /* Warn if value is too big to fit in the field in question. */
3287 if (0 != (fieldval
& ~mask
))
3289 /* FIXME: would like to include fieldval in the message, but
3290 we don't have a sprintf_longest. */
3291 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3293 /* Truncate it, otherwise adjoining fields may be corrupted. */
3297 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3298 false valgrind reports. */
3300 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3301 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3303 /* Shifting for bit field depends on endianness of the target machine. */
3304 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3305 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3307 oword
&= ~(mask
<< bitpos
);
3308 oword
|= fieldval
<< bitpos
;
3310 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3313 /* Pack NUM into BUF using a target format of TYPE. */
3316 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3318 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3321 type
= check_typedef (type
);
3322 len
= TYPE_LENGTH (type
);
3324 switch (TYPE_CODE (type
))
3326 case TYPE_CODE_RANGE
:
3327 num
-= TYPE_RANGE_DATA (type
)->bias
;
3330 case TYPE_CODE_CHAR
:
3331 case TYPE_CODE_ENUM
:
3332 case TYPE_CODE_FLAGS
:
3333 case TYPE_CODE_BOOL
:
3334 case TYPE_CODE_MEMBERPTR
:
3335 store_signed_integer (buf
, len
, byte_order
, num
);
3339 case TYPE_CODE_RVALUE_REF
:
3341 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3345 case TYPE_CODE_DECFLOAT
:
3346 target_float_from_longest (buf
, type
, num
);
3350 error (_("Unexpected type (%d) encountered for integer constant."),
3356 /* Pack NUM into BUF using a target format of TYPE. */
3359 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3362 enum bfd_endian byte_order
;
3364 type
= check_typedef (type
);
3365 len
= TYPE_LENGTH (type
);
3366 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3368 switch (TYPE_CODE (type
))
3371 case TYPE_CODE_CHAR
:
3372 case TYPE_CODE_ENUM
:
3373 case TYPE_CODE_FLAGS
:
3374 case TYPE_CODE_BOOL
:
3375 case TYPE_CODE_RANGE
:
3376 case TYPE_CODE_MEMBERPTR
:
3377 store_unsigned_integer (buf
, len
, byte_order
, num
);
3381 case TYPE_CODE_RVALUE_REF
:
3383 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3387 case TYPE_CODE_DECFLOAT
:
3388 target_float_from_ulongest (buf
, type
, num
);
3392 error (_("Unexpected type (%d) encountered "
3393 "for unsigned integer constant."),
3399 /* Convert C numbers into newly allocated values. */
3402 value_from_longest (struct type
*type
, LONGEST num
)
3404 struct value
*val
= allocate_value (type
);
3406 pack_long (value_contents_raw (val
), type
, num
);
3411 /* Convert C unsigned numbers into newly allocated values. */
3414 value_from_ulongest (struct type
*type
, ULONGEST num
)
3416 struct value
*val
= allocate_value (type
);
3418 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3424 /* Create a value representing a pointer of type TYPE to the address
3428 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3430 struct value
*val
= allocate_value (type
);
3432 store_typed_address (value_contents_raw (val
),
3433 check_typedef (type
), addr
);
3437 /* Create and return a value object of TYPE containing the value D. The
3438 TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
3439 it is converted to target format. */
3442 value_from_host_double (struct type
*type
, double d
)
3444 struct value
*value
= allocate_value (type
);
3445 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FLT
);
3446 target_float_from_host_double (value_contents_raw (value
),
3447 value_type (value
), d
);
3451 /* Create a value of type TYPE whose contents come from VALADDR, if it
3452 is non-null, and whose memory address (in the inferior) is
3453 ADDRESS. The type of the created value may differ from the passed
3454 type TYPE. Make sure to retrieve values new type after this call.
3455 Note that TYPE is not passed through resolve_dynamic_type; this is
3456 a special API intended for use only by Ada. */
3459 value_from_contents_and_address_unresolved (struct type
*type
,
3460 const gdb_byte
*valaddr
,
3465 if (valaddr
== NULL
)
3466 v
= allocate_value_lazy (type
);
3468 v
= value_from_contents (type
, valaddr
);
3469 VALUE_LVAL (v
) = lval_memory
;
3470 set_value_address (v
, address
);
3474 /* Create a value of type TYPE whose contents come from VALADDR, if it
3475 is non-null, and whose memory address (in the inferior) is
3476 ADDRESS. The type of the created value may differ from the passed
3477 type TYPE. Make sure to retrieve values new type after this call. */
3480 value_from_contents_and_address (struct type
*type
,
3481 const gdb_byte
*valaddr
,
3484 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3485 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3488 if (valaddr
== NULL
)
3489 v
= allocate_value_lazy (resolved_type
);
3491 v
= value_from_contents (resolved_type
, valaddr
);
3492 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3493 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3494 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3495 VALUE_LVAL (v
) = lval_memory
;
3496 set_value_address (v
, address
);
3500 /* Create a value of type TYPE holding the contents CONTENTS.
3501 The new value is `not_lval'. */
3504 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3506 struct value
*result
;
3508 result
= allocate_value (type
);
3509 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3513 /* Extract a value from the history file. Input will be of the form
3514 $digits or $$digits. See block comment above 'write_dollar_variable'
3518 value_from_history_ref (const char *h
, const char **endp
)
3530 /* Find length of numeral string. */
3531 for (; isdigit (h
[len
]); len
++)
3534 /* Make sure numeral string is not part of an identifier. */
3535 if (h
[len
] == '_' || isalpha (h
[len
]))
3538 /* Now collect the index value. */
3543 /* For some bizarre reason, "$$" is equivalent to "$$1",
3544 rather than to "$$0" as it ought to be! */
3552 index
= -strtol (&h
[2], &local_end
, 10);
3560 /* "$" is equivalent to "$0". */
3568 index
= strtol (&h
[1], &local_end
, 10);
3573 return access_value_history (index
);
3576 /* Get the component value (offset by OFFSET bytes) of a struct or
3577 union WHOLE. Component's type is TYPE. */
3580 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3584 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3585 v
= allocate_value_lazy (type
);
3588 v
= allocate_value (type
);
3589 value_contents_copy (v
, value_embedded_offset (v
),
3590 whole
, value_embedded_offset (whole
) + offset
,
3591 type_length_units (type
));
3593 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3594 set_value_component_location (v
, whole
);
3600 coerce_ref_if_computed (const struct value
*arg
)
3602 const struct lval_funcs
*funcs
;
3604 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3607 if (value_lval_const (arg
) != lval_computed
)
3610 funcs
= value_computed_funcs (arg
);
3611 if (funcs
->coerce_ref
== NULL
)
3614 return funcs
->coerce_ref (arg
);
3617 /* Look at value.h for description. */
3620 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3621 const struct type
*original_type
,
3622 const struct value
*original_value
)
3624 /* Re-adjust type. */
3625 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3627 /* Add embedding info. */
3628 set_value_enclosing_type (value
, enc_type
);
3629 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3631 /* We may be pointing to an object of some derived type. */
3632 return value_full_object (value
, NULL
, 0, 0, 0);
3636 coerce_ref (struct value
*arg
)
3638 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3639 struct value
*retval
;
3640 struct type
*enc_type
;
3642 retval
= coerce_ref_if_computed (arg
);
3646 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3649 enc_type
= check_typedef (value_enclosing_type (arg
));
3650 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3652 retval
= value_at_lazy (enc_type
,
3653 unpack_pointer (value_type (arg
),
3654 value_contents (arg
)));
3655 enc_type
= value_type (retval
);
3656 return readjust_indirect_value_type (retval
, enc_type
,
3657 value_type_arg_tmp
, arg
);
3661 coerce_array (struct value
*arg
)
3665 arg
= coerce_ref (arg
);
3666 type
= check_typedef (value_type (arg
));
3668 switch (TYPE_CODE (type
))
3670 case TYPE_CODE_ARRAY
:
3671 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3672 arg
= value_coerce_array (arg
);
3674 case TYPE_CODE_FUNC
:
3675 arg
= value_coerce_function (arg
);
3682 /* Return the return value convention that will be used for the
3685 enum return_value_convention
3686 struct_return_convention (struct gdbarch
*gdbarch
,
3687 struct value
*function
, struct type
*value_type
)
3689 enum type_code code
= TYPE_CODE (value_type
);
3691 if (code
== TYPE_CODE_ERROR
)
3692 error (_("Function return type unknown."));
3694 /* Probe the architecture for the return-value convention. */
3695 return gdbarch_return_value (gdbarch
, function
, value_type
,
3699 /* Return true if the function returning the specified type is using
3700 the convention of returning structures in memory (passing in the
3701 address as a hidden first parameter). */
3704 using_struct_return (struct gdbarch
*gdbarch
,
3705 struct value
*function
, struct type
*value_type
)
3707 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3708 /* A void return value is never in memory. See also corresponding
3709 code in "print_return_value". */
3712 return (struct_return_convention (gdbarch
, function
, value_type
)
3713 != RETURN_VALUE_REGISTER_CONVENTION
);
3716 /* Set the initialized field in a value struct. */
3719 set_value_initialized (struct value
*val
, int status
)
3721 val
->initialized
= status
;
3724 /* Return the initialized field in a value struct. */
3727 value_initialized (const struct value
*val
)
3729 return val
->initialized
;
3732 /* Helper for value_fetch_lazy when the value is a bitfield. */
3735 value_fetch_lazy_bitfield (struct value
*val
)
3737 gdb_assert (value_bitsize (val
) != 0);
3739 /* To read a lazy bitfield, read the entire enclosing value. This
3740 prevents reading the same block of (possibly volatile) memory once
3741 per bitfield. It would be even better to read only the containing
3742 word, but we have no way to record that just specific bits of a
3743 value have been fetched. */
3744 struct value
*parent
= value_parent (val
);
3746 if (value_lazy (parent
))
3747 value_fetch_lazy (parent
);
3749 unpack_value_bitfield (val
, value_bitpos (val
), value_bitsize (val
),
3750 value_contents_for_printing (parent
),
3751 value_offset (val
), parent
);
3754 /* Helper for value_fetch_lazy when the value is in memory. */
3757 value_fetch_lazy_memory (struct value
*val
)
3759 gdb_assert (VALUE_LVAL (val
) == lval_memory
);
3761 CORE_ADDR addr
= value_address (val
);
3762 struct type
*type
= check_typedef (value_enclosing_type (val
));
3764 if (TYPE_LENGTH (type
))
3765 read_value_memory (val
, 0, value_stack (val
),
3766 addr
, value_contents_all_raw (val
),
3767 type_length_units (type
));
3770 /* Helper for value_fetch_lazy when the value is in a register. */
3773 value_fetch_lazy_register (struct value
*val
)
3775 struct frame_info
*next_frame
;
3777 struct type
*type
= check_typedef (value_type (val
));
3778 struct value
*new_val
= val
, *mark
= value_mark ();
3780 /* Offsets are not supported here; lazy register values must
3781 refer to the entire register. */
3782 gdb_assert (value_offset (val
) == 0);
3784 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3786 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3788 next_frame
= frame_find_by_id (next_frame_id
);
3789 regnum
= VALUE_REGNUM (new_val
);
3791 gdb_assert (next_frame
!= NULL
);
3793 /* Convertible register routines are used for multi-register
3794 values and for interpretation in different types
3795 (e.g. float or int from a double register). Lazy
3796 register values should have the register's natural type,
3797 so they do not apply. */
3798 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3801 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3802 Since a "->next" operation was performed when setting
3803 this field, we do not need to perform a "next" operation
3804 again when unwinding the register. That's why
3805 frame_unwind_register_value() is called here instead of
3806 get_frame_register_value(). */
3807 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3809 /* If we get another lazy lval_register value, it means the
3810 register is found by reading it from NEXT_FRAME's next frame.
3811 frame_unwind_register_value should never return a value with
3812 the frame id pointing to NEXT_FRAME. If it does, it means we
3813 either have two consecutive frames with the same frame id
3814 in the frame chain, or some code is trying to unwind
3815 behind get_prev_frame's back (e.g., a frame unwind
3816 sniffer trying to unwind), bypassing its validations. In
3817 any case, it should always be an internal error to end up
3818 in this situation. */
3819 if (VALUE_LVAL (new_val
) == lval_register
3820 && value_lazy (new_val
)
3821 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3822 internal_error (__FILE__
, __LINE__
,
3823 _("infinite loop while fetching a register"));
3826 /* If it's still lazy (for instance, a saved register on the
3827 stack), fetch it. */
3828 if (value_lazy (new_val
))
3829 value_fetch_lazy (new_val
);
3831 /* Copy the contents and the unavailability/optimized-out
3832 meta-data from NEW_VAL to VAL. */
3833 set_value_lazy (val
, 0);
3834 value_contents_copy (val
, value_embedded_offset (val
),
3835 new_val
, value_embedded_offset (new_val
),
3836 type_length_units (type
));
3840 struct gdbarch
*gdbarch
;
3841 struct frame_info
*frame
;
3842 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3843 so that the frame level will be shown correctly. */
3844 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3845 regnum
= VALUE_REGNUM (val
);
3846 gdbarch
= get_frame_arch (frame
);
3848 fprintf_unfiltered (gdb_stdlog
,
3849 "{ value_fetch_lazy "
3850 "(frame=%d,regnum=%d(%s),...) ",
3851 frame_relative_level (frame
), regnum
,
3852 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3854 fprintf_unfiltered (gdb_stdlog
, "->");
3855 if (value_optimized_out (new_val
))
3857 fprintf_unfiltered (gdb_stdlog
, " ");
3858 val_print_optimized_out (new_val
, gdb_stdlog
);
3863 const gdb_byte
*buf
= value_contents (new_val
);
3865 if (VALUE_LVAL (new_val
) == lval_register
)
3866 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3867 VALUE_REGNUM (new_val
));
3868 else if (VALUE_LVAL (new_val
) == lval_memory
)
3869 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3871 value_address (new_val
)));
3873 fprintf_unfiltered (gdb_stdlog
, " computed");
3875 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3876 fprintf_unfiltered (gdb_stdlog
, "[");
3877 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3878 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3879 fprintf_unfiltered (gdb_stdlog
, "]");
3882 fprintf_unfiltered (gdb_stdlog
, " }\n");
3885 /* Dispose of the intermediate values. This prevents
3886 watchpoints from trying to watch the saved frame pointer. */
3887 value_free_to_mark (mark
);
3890 /* Load the actual content of a lazy value. Fetch the data from the
3891 user's process and clear the lazy flag to indicate that the data in
3892 the buffer is valid.
3894 If the value is zero-length, we avoid calling read_memory, which
3895 would abort. We mark the value as fetched anyway -- all 0 bytes of
3899 value_fetch_lazy (struct value
*val
)
3901 gdb_assert (value_lazy (val
));
3902 allocate_value_contents (val
);
3903 /* A value is either lazy, or fully fetched. The
3904 availability/validity is only established as we try to fetch a
3906 gdb_assert (val
->optimized_out
.empty ());
3907 gdb_assert (val
->unavailable
.empty ());
3908 if (value_bitsize (val
))
3909 value_fetch_lazy_bitfield (val
);
3910 else if (VALUE_LVAL (val
) == lval_memory
)
3911 value_fetch_lazy_memory (val
);
3912 else if (VALUE_LVAL (val
) == lval_register
)
3913 value_fetch_lazy_register (val
);
3914 else if (VALUE_LVAL (val
) == lval_computed
3915 && value_computed_funcs (val
)->read
!= NULL
)
3916 value_computed_funcs (val
)->read (val
);
3918 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3920 set_value_lazy (val
, 0);
3923 /* Implementation of the convenience function $_isvoid. */
3925 static struct value
*
3926 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3927 const struct language_defn
*language
,
3928 void *cookie
, int argc
, struct value
**argv
)
3933 error (_("You must provide one argument for $_isvoid."));
3935 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3937 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3940 /* Implementation of the convenience function $_cimag. Extracts the
3941 real part from a complex number. */
3943 static struct value
*
3944 creal_internal_fn (struct gdbarch
*gdbarch
,
3945 const struct language_defn
*language
,
3946 void *cookie
, int argc
, struct value
**argv
)
3949 error (_("You must provide one argument for $_creal."));
3951 value
*cval
= argv
[0];
3952 type
*ctype
= check_typedef (value_type (cval
));
3953 if (TYPE_CODE (ctype
) != TYPE_CODE_COMPLEX
)
3954 error (_("expected a complex number"));
3955 return value_from_component (cval
, TYPE_TARGET_TYPE (ctype
), 0);
3958 /* Implementation of the convenience function $_cimag. Extracts the
3959 imaginary part from a complex number. */
3961 static struct value
*
3962 cimag_internal_fn (struct gdbarch
*gdbarch
,
3963 const struct language_defn
*language
,
3964 void *cookie
, int argc
,
3965 struct value
**argv
)
3968 error (_("You must provide one argument for $_cimag."));
3970 value
*cval
= argv
[0];
3971 type
*ctype
= check_typedef (value_type (cval
));
3972 if (TYPE_CODE (ctype
) != TYPE_CODE_COMPLEX
)
3973 error (_("expected a complex number"));
3974 return value_from_component (cval
, TYPE_TARGET_TYPE (ctype
),
3975 TYPE_LENGTH (TYPE_TARGET_TYPE (ctype
)));
3982 /* Test the ranges_contain function. */
3985 test_ranges_contain ()
3987 std::vector
<range
> ranges
;
3993 ranges
.push_back (r
);
3998 ranges
.push_back (r
);
4001 SELF_CHECK (!ranges_contain (ranges
, 2, 5));
4003 SELF_CHECK (ranges_contain (ranges
, 9, 5));
4005 SELF_CHECK (ranges_contain (ranges
, 10, 2));
4007 SELF_CHECK (ranges_contain (ranges
, 10, 5));
4009 SELF_CHECK (ranges_contain (ranges
, 13, 6));
4011 SELF_CHECK (ranges_contain (ranges
, 14, 5));
4013 SELF_CHECK (!ranges_contain (ranges
, 15, 4));
4015 SELF_CHECK (!ranges_contain (ranges
, 16, 4));
4017 SELF_CHECK (ranges_contain (ranges
, 16, 6));
4019 SELF_CHECK (ranges_contain (ranges
, 21, 1));
4021 SELF_CHECK (ranges_contain (ranges
, 21, 5));
4023 SELF_CHECK (!ranges_contain (ranges
, 26, 3));
4026 /* Check that RANGES contains the same ranges as EXPECTED. */
4029 check_ranges_vector (gdb::array_view
<const range
> ranges
,
4030 gdb::array_view
<const range
> expected
)
4032 return ranges
== expected
;
4035 /* Test the insert_into_bit_range_vector function. */
4038 test_insert_into_bit_range_vector ()
4040 std::vector
<range
> ranges
;
4044 insert_into_bit_range_vector (&ranges
, 10, 5);
4045 static const range expected
[] = {
4048 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4053 insert_into_bit_range_vector (&ranges
, 11, 4);
4054 static const range expected
= {10, 5};
4055 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4058 /* [10, 14] [20, 24] */
4060 insert_into_bit_range_vector (&ranges
, 20, 5);
4061 static const range expected
[] = {
4065 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4068 /* [10, 14] [17, 24] */
4070 insert_into_bit_range_vector (&ranges
, 17, 5);
4071 static const range expected
[] = {
4075 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4078 /* [2, 8] [10, 14] [17, 24] */
4080 insert_into_bit_range_vector (&ranges
, 2, 7);
4081 static const range expected
[] = {
4086 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4089 /* [2, 14] [17, 24] */
4091 insert_into_bit_range_vector (&ranges
, 9, 1);
4092 static const range expected
[] = {
4096 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4099 /* [2, 14] [17, 24] */
4101 insert_into_bit_range_vector (&ranges
, 9, 1);
4102 static const range expected
[] = {
4106 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4111 insert_into_bit_range_vector (&ranges
, 4, 30);
4112 static const range expected
= {2, 32};
4113 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4117 } /* namespace selftests */
4118 #endif /* GDB_SELF_TEST */
4121 _initialize_values (void)
4123 add_cmd ("convenience", no_class
, show_convenience
, _("\
4124 Debugger convenience (\"$foo\") variables and functions.\n\
4125 Convenience variables are created when you assign them values;\n\
4126 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4128 A few convenience variables are given values automatically:\n\
4129 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4130 \"$__\" holds the contents of the last address examined with \"x\"."
4133 Convenience functions are defined via the Python API."
4136 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4138 add_cmd ("values", no_set_class
, show_values
, _("\
4139 Elements of value history around item number IDX (or last ten)."),
4142 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4143 Initialize a convenience variable if necessary.\n\
4144 init-if-undefined VARIABLE = EXPRESSION\n\
4145 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4146 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4147 VARIABLE is already initialized."));
4149 add_prefix_cmd ("function", no_class
, function_command
, _("\
4150 Placeholder command for showing help on convenience functions."),
4151 &functionlist
, "function ", 0, &cmdlist
);
4153 add_internal_function ("_isvoid", _("\
4154 Check whether an expression is void.\n\
4155 Usage: $_isvoid (expression)\n\
4156 Return 1 if the expression is void, zero otherwise."),
4157 isvoid_internal_fn
, NULL
);
4159 add_internal_function ("_creal", _("\
4160 Extract the real part of a complex number.\n\
4161 Usage: $_creal (expression)\n\
4162 Return the real part of a complex number, the type depends on the\n\
4163 type of a complex number."),
4164 creal_internal_fn
, NULL
);
4166 add_internal_function ("_cimag", _("\
4167 Extract the imaginary part of a complex number.\n\
4168 Usage: $_cimag (expression)\n\
4169 Return the imaginary part of a complex number, the type depends on the\n\
4170 type of a complex number."),
4171 cimag_internal_fn
, NULL
);
4173 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4174 class_support
, &max_value_size
, _("\
4175 Set maximum sized value gdb will load from the inferior."), _("\
4176 Show maximum sized value gdb will load from the inferior."), _("\
4177 Use this to control the maximum size, in bytes, of a value that gdb\n\
4178 will load from the inferior. Setting this value to 'unlimited'\n\
4179 disables checking.\n\
4180 Setting this does not invalidate already allocated values, it only\n\
4181 prevents future values, larger than this size, from being allocated."),
4183 show_max_value_size
,
4184 &setlist
, &showlist
);
4186 selftests::register_test ("ranges_contain", selftests::test_ranges_contain
);
4187 selftests::register_test ("insert_into_bit_range_vector",
4188 selftests::test_insert_into_bit_range_vector
);
4197 all_values
.clear ();