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
);
2431 /* Helper function that does the work for add_internal_function. */
2433 static struct cmd_list_element
*
2434 do_add_internal_function (const char *name
, const char *doc
,
2435 internal_function_fn handler
, void *cookie
)
2437 struct cmd_list_element
*cmd
;
2438 struct internal_function
*ifn
;
2439 struct internalvar
*var
= lookup_internalvar (name
);
2441 ifn
= create_internal_function (name
, handler
, cookie
);
2442 set_internalvar_function (var
, ifn
);
2444 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2446 cmd
->destroyer
= function_destroyer
;
2454 add_internal_function (const char *name
, const char *doc
,
2455 internal_function_fn handler
, void *cookie
)
2457 do_add_internal_function (name
, doc
, handler
, cookie
);
2463 add_internal_function (const char *name
, gdb::unique_xmalloc_ptr
<char> &&doc
,
2464 internal_function_fn handler
, void *cookie
)
2466 struct cmd_list_element
*cmd
2467 = do_add_internal_function (name
, doc
.get (), handler
, cookie
);
2469 cmd
->doc_allocated
= 1;
2472 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2473 prevent cycles / duplicates. */
2476 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2477 htab_t copied_types
)
2479 if (TYPE_OBJFILE (value
->type
) == objfile
)
2480 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2482 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2483 value
->enclosing_type
= copy_type_recursive (objfile
,
2484 value
->enclosing_type
,
2488 /* Likewise for internal variable VAR. */
2491 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2492 htab_t copied_types
)
2496 case INTERNALVAR_INTEGER
:
2497 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2499 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2502 case INTERNALVAR_VALUE
:
2503 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2508 /* Update the internal variables and value history when OBJFILE is
2509 discarded; we must copy the types out of the objfile. New global types
2510 will be created for every convenience variable which currently points to
2511 this objfile's types, and the convenience variables will be adjusted to
2512 use the new global types. */
2515 preserve_values (struct objfile
*objfile
)
2517 htab_t copied_types
;
2518 struct internalvar
*var
;
2520 /* Create the hash table. We allocate on the objfile's obstack, since
2521 it is soon to be deleted. */
2522 copied_types
= create_copied_types_hash (objfile
);
2524 for (const value_ref_ptr
&item
: value_history
)
2525 preserve_one_value (item
.get (), objfile
, copied_types
);
2527 for (var
= internalvars
; var
; var
= var
->next
)
2528 preserve_one_internalvar (var
, objfile
, copied_types
);
2530 preserve_ext_lang_values (objfile
, copied_types
);
2532 htab_delete (copied_types
);
2536 show_convenience (const char *ignore
, int from_tty
)
2538 struct gdbarch
*gdbarch
= get_current_arch ();
2539 struct internalvar
*var
;
2541 struct value_print_options opts
;
2543 get_user_print_options (&opts
);
2544 for (var
= internalvars
; var
; var
= var
->next
)
2551 printf_filtered (("$%s = "), var
->name
);
2557 val
= value_of_internalvar (gdbarch
, var
);
2558 value_print (val
, gdb_stdout
, &opts
);
2560 catch (const gdb_exception_error
&ex
)
2562 fprintf_styled (gdb_stdout
, metadata_style
.style (),
2563 _("<error: %s>"), ex
.what ());
2566 printf_filtered (("\n"));
2570 /* This text does not mention convenience functions on purpose.
2571 The user can't create them except via Python, and if Python support
2572 is installed this message will never be printed ($_streq will
2574 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2575 "Convenience variables have "
2576 "names starting with \"$\";\n"
2577 "use \"set\" as in \"set "
2578 "$foo = 5\" to define them.\n"));
2586 value_from_xmethod (xmethod_worker_up
&&worker
)
2590 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2591 v
->lval
= lval_xcallable
;
2592 v
->location
.xm_worker
= worker
.release ();
2598 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2601 result_type_of_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2603 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2604 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2606 return method
->location
.xm_worker
->get_result_type (argv
[0], argv
.slice (1));
2609 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2612 call_xmethod (struct value
*method
, gdb::array_view
<value
*> argv
)
2614 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2615 && method
->lval
== lval_xcallable
&& !argv
.empty ());
2617 return method
->location
.xm_worker
->invoke (argv
[0], argv
.slice (1));
2620 /* Extract a value as a C number (either long or double).
2621 Knows how to convert fixed values to double, or
2622 floating values to long.
2623 Does not deallocate the value. */
2626 value_as_long (struct value
*val
)
2628 /* This coerces arrays and functions, which is necessary (e.g.
2629 in disassemble_command). It also dereferences references, which
2630 I suspect is the most logical thing to do. */
2631 val
= coerce_array (val
);
2632 return unpack_long (value_type (val
), value_contents (val
));
2635 /* Extract a value as a C pointer. Does not deallocate the value.
2636 Note that val's type may not actually be a pointer; value_as_long
2637 handles all the cases. */
2639 value_as_address (struct value
*val
)
2641 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2643 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2644 whether we want this to be true eventually. */
2646 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2647 non-address (e.g. argument to "signal", "info break", etc.), or
2648 for pointers to char, in which the low bits *are* significant. */
2649 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2652 /* There are several targets (IA-64, PowerPC, and others) which
2653 don't represent pointers to functions as simply the address of
2654 the function's entry point. For example, on the IA-64, a
2655 function pointer points to a two-word descriptor, generated by
2656 the linker, which contains the function's entry point, and the
2657 value the IA-64 "global pointer" register should have --- to
2658 support position-independent code. The linker generates
2659 descriptors only for those functions whose addresses are taken.
2661 On such targets, it's difficult for GDB to convert an arbitrary
2662 function address into a function pointer; it has to either find
2663 an existing descriptor for that function, or call malloc and
2664 build its own. On some targets, it is impossible for GDB to
2665 build a descriptor at all: the descriptor must contain a jump
2666 instruction; data memory cannot be executed; and code memory
2669 Upon entry to this function, if VAL is a value of type `function'
2670 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2671 value_address (val) is the address of the function. This is what
2672 you'll get if you evaluate an expression like `main'. The call
2673 to COERCE_ARRAY below actually does all the usual unary
2674 conversions, which includes converting values of type `function'
2675 to `pointer to function'. This is the challenging conversion
2676 discussed above. Then, `unpack_long' will convert that pointer
2677 back into an address.
2679 So, suppose the user types `disassemble foo' on an architecture
2680 with a strange function pointer representation, on which GDB
2681 cannot build its own descriptors, and suppose further that `foo'
2682 has no linker-built descriptor. The address->pointer conversion
2683 will signal an error and prevent the command from running, even
2684 though the next step would have been to convert the pointer
2685 directly back into the same address.
2687 The following shortcut avoids this whole mess. If VAL is a
2688 function, just return its address directly. */
2689 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2690 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2691 return value_address (val
);
2693 val
= coerce_array (val
);
2695 /* Some architectures (e.g. Harvard), map instruction and data
2696 addresses onto a single large unified address space. For
2697 instance: An architecture may consider a large integer in the
2698 range 0x10000000 .. 0x1000ffff to already represent a data
2699 addresses (hence not need a pointer to address conversion) while
2700 a small integer would still need to be converted integer to
2701 pointer to address. Just assume such architectures handle all
2702 integer conversions in a single function. */
2706 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2707 must admonish GDB hackers to make sure its behavior matches the
2708 compiler's, whenever possible.
2710 In general, I think GDB should evaluate expressions the same way
2711 the compiler does. When the user copies an expression out of
2712 their source code and hands it to a `print' command, they should
2713 get the same value the compiler would have computed. Any
2714 deviation from this rule can cause major confusion and annoyance,
2715 and needs to be justified carefully. In other words, GDB doesn't
2716 really have the freedom to do these conversions in clever and
2719 AndrewC pointed out that users aren't complaining about how GDB
2720 casts integers to pointers; they are complaining that they can't
2721 take an address from a disassembly listing and give it to `x/i'.
2722 This is certainly important.
2724 Adding an architecture method like integer_to_address() certainly
2725 makes it possible for GDB to "get it right" in all circumstances
2726 --- the target has complete control over how things get done, so
2727 people can Do The Right Thing for their target without breaking
2728 anyone else. The standard doesn't specify how integers get
2729 converted to pointers; usually, the ABI doesn't either, but
2730 ABI-specific code is a more reasonable place to handle it. */
2732 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2733 && !TYPE_IS_REFERENCE (value_type (val
))
2734 && gdbarch_integer_to_address_p (gdbarch
))
2735 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2736 value_contents (val
));
2738 return unpack_long (value_type (val
), value_contents (val
));
2742 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2743 as a long, or as a double, assuming the raw data is described
2744 by type TYPE. Knows how to convert different sizes of values
2745 and can convert between fixed and floating point. We don't assume
2746 any alignment for the raw data. Return value is in host byte order.
2748 If you want functions and arrays to be coerced to pointers, and
2749 references to be dereferenced, call value_as_long() instead.
2751 C++: It is assumed that the front-end has taken care of
2752 all matters concerning pointers to members. A pointer
2753 to member which reaches here is considered to be equivalent
2754 to an INT (or some size). After all, it is only an offset. */
2757 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2759 enum bfd_endian byte_order
= type_byte_order (type
);
2760 enum type_code code
= TYPE_CODE (type
);
2761 int len
= TYPE_LENGTH (type
);
2762 int nosign
= TYPE_UNSIGNED (type
);
2766 case TYPE_CODE_TYPEDEF
:
2767 return unpack_long (check_typedef (type
), valaddr
);
2768 case TYPE_CODE_ENUM
:
2769 case TYPE_CODE_FLAGS
:
2770 case TYPE_CODE_BOOL
:
2772 case TYPE_CODE_CHAR
:
2773 case TYPE_CODE_RANGE
:
2774 case TYPE_CODE_MEMBERPTR
:
2778 result
= extract_unsigned_integer (valaddr
, len
, byte_order
);
2780 result
= extract_signed_integer (valaddr
, len
, byte_order
);
2781 if (code
== TYPE_CODE_RANGE
)
2782 result
+= TYPE_RANGE_DATA (type
)->bias
;
2787 case TYPE_CODE_DECFLOAT
:
2788 return target_float_to_longest (valaddr
, type
);
2792 case TYPE_CODE_RVALUE_REF
:
2793 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2794 whether we want this to be true eventually. */
2795 return extract_typed_address (valaddr
, type
);
2798 error (_("Value can't be converted to integer."));
2802 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2803 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2804 We don't assume any alignment for the raw data. Return value is in
2807 If you want functions and arrays to be coerced to pointers, and
2808 references to be dereferenced, call value_as_address() instead.
2810 C++: It is assumed that the front-end has taken care of
2811 all matters concerning pointers to members. A pointer
2812 to member which reaches here is considered to be equivalent
2813 to an INT (or some size). After all, it is only an offset. */
2816 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2818 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2819 whether we want this to be true eventually. */
2820 return unpack_long (type
, valaddr
);
2824 is_floating_value (struct value
*val
)
2826 struct type
*type
= check_typedef (value_type (val
));
2828 if (is_floating_type (type
))
2830 if (!target_float_is_valid (value_contents (val
), type
))
2831 error (_("Invalid floating value found in program."));
2839 /* Get the value of the FIELDNO'th field (which must be static) of
2843 value_static_field (struct type
*type
, int fieldno
)
2845 struct value
*retval
;
2847 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2849 case FIELD_LOC_KIND_PHYSADDR
:
2850 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2851 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2853 case FIELD_LOC_KIND_PHYSNAME
:
2855 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2856 /* TYPE_FIELD_NAME (type, fieldno); */
2857 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2859 if (sym
.symbol
== NULL
)
2861 /* With some compilers, e.g. HP aCC, static data members are
2862 reported as non-debuggable symbols. */
2863 struct bound_minimal_symbol msym
2864 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2865 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2868 retval
= allocate_optimized_out_value (field_type
);
2870 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2873 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2877 gdb_assert_not_reached ("unexpected field location kind");
2883 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2884 You have to be careful here, since the size of the data area for the value
2885 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2886 than the old enclosing type, you have to allocate more space for the
2890 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2892 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2894 check_type_length_before_alloc (new_encl_type
);
2896 .reset ((gdb_byte
*) xrealloc (val
->contents
.release (),
2897 TYPE_LENGTH (new_encl_type
)));
2900 val
->enclosing_type
= new_encl_type
;
2903 /* Given a value ARG1 (offset by OFFSET bytes)
2904 of a struct or union type ARG_TYPE,
2905 extract and return the value of one of its (non-static) fields.
2906 FIELDNO says which field. */
2909 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2910 int fieldno
, struct type
*arg_type
)
2914 struct gdbarch
*arch
= get_value_arch (arg1
);
2915 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2917 arg_type
= check_typedef (arg_type
);
2918 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2920 /* Call check_typedef on our type to make sure that, if TYPE
2921 is a TYPE_CODE_TYPEDEF, its length is set to the length
2922 of the target type instead of zero. However, we do not
2923 replace the typedef type by the target type, because we want
2924 to keep the typedef in order to be able to print the type
2925 description correctly. */
2926 check_typedef (type
);
2928 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2930 /* Handle packed fields.
2932 Create a new value for the bitfield, with bitpos and bitsize
2933 set. If possible, arrange offset and bitpos so that we can
2934 do a single aligned read of the size of the containing type.
2935 Otherwise, adjust offset to the byte containing the first
2936 bit. Assume that the address, offset, and embedded offset
2937 are sufficiently aligned. */
2939 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2940 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2942 v
= allocate_value_lazy (type
);
2943 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2944 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2945 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2946 v
->bitpos
= bitpos
% container_bitsize
;
2948 v
->bitpos
= bitpos
% 8;
2949 v
->offset
= (value_embedded_offset (arg1
)
2951 + (bitpos
- v
->bitpos
) / 8);
2952 set_value_parent (v
, arg1
);
2953 if (!value_lazy (arg1
))
2954 value_fetch_lazy (v
);
2956 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2958 /* This field is actually a base subobject, so preserve the
2959 entire object's contents for later references to virtual
2963 /* Lazy register values with offsets are not supported. */
2964 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2965 value_fetch_lazy (arg1
);
2967 /* We special case virtual inheritance here because this
2968 requires access to the contents, which we would rather avoid
2969 for references to ordinary fields of unavailable values. */
2970 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2971 boffset
= baseclass_offset (arg_type
, fieldno
,
2972 value_contents (arg1
),
2973 value_embedded_offset (arg1
),
2974 value_address (arg1
),
2977 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2979 if (value_lazy (arg1
))
2980 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2983 v
= allocate_value (value_enclosing_type (arg1
));
2984 value_contents_copy_raw (v
, 0, arg1
, 0,
2985 TYPE_LENGTH (value_enclosing_type (arg1
)));
2988 v
->offset
= value_offset (arg1
);
2989 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2991 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2993 /* Field is a dynamic data member. */
2995 gdb_assert (0 == offset
);
2996 /* We expect an already resolved data location. */
2997 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
2998 /* For dynamic data types defer memory allocation
2999 until we actual access the value. */
3000 v
= allocate_value_lazy (type
);
3004 /* Plain old data member */
3005 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3006 / (HOST_CHAR_BIT
* unit_size
));
3008 /* Lazy register values with offsets are not supported. */
3009 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3010 value_fetch_lazy (arg1
);
3012 if (value_lazy (arg1
))
3013 v
= allocate_value_lazy (type
);
3016 v
= allocate_value (type
);
3017 value_contents_copy_raw (v
, value_embedded_offset (v
),
3018 arg1
, value_embedded_offset (arg1
) + offset
,
3019 type_length_units (type
));
3021 v
->offset
= (value_offset (arg1
) + offset
3022 + value_embedded_offset (arg1
));
3024 set_value_component_location (v
, arg1
);
3028 /* Given a value ARG1 of a struct or union type,
3029 extract and return the value of one of its (non-static) fields.
3030 FIELDNO says which field. */
3033 value_field (struct value
*arg1
, int fieldno
)
3035 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3038 /* Return a non-virtual function as a value.
3039 F is the list of member functions which contains the desired method.
3040 J is an index into F which provides the desired method.
3042 We only use the symbol for its address, so be happy with either a
3043 full symbol or a minimal symbol. */
3046 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3047 int j
, struct type
*type
,
3051 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3052 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3054 struct bound_minimal_symbol msym
;
3056 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3059 memset (&msym
, 0, sizeof (msym
));
3063 gdb_assert (sym
== NULL
);
3064 msym
= lookup_bound_minimal_symbol (physname
);
3065 if (msym
.minsym
== NULL
)
3069 v
= allocate_value (ftype
);
3070 VALUE_LVAL (v
) = lval_memory
;
3073 set_value_address (v
, BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (sym
)));
3077 /* The minimal symbol might point to a function descriptor;
3078 resolve it to the actual code address instead. */
3079 struct objfile
*objfile
= msym
.objfile
;
3080 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3082 set_value_address (v
,
3083 gdbarch_convert_from_func_ptr_addr
3084 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), current_top_target ()));
3089 if (type
!= value_type (*arg1p
))
3090 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3091 value_addr (*arg1p
)));
3093 /* Move the `this' pointer according to the offset.
3094 VALUE_OFFSET (*arg1p) += offset; */
3102 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3103 VALADDR, and store the result in *RESULT.
3104 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3105 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3107 Extracting bits depends on endianness of the machine. Compute the
3108 number of least significant bits to discard. For big endian machines,
3109 we compute the total number of bits in the anonymous object, subtract
3110 off the bit count from the MSB of the object to the MSB of the
3111 bitfield, then the size of the bitfield, which leaves the LSB discard
3112 count. For little endian machines, the discard count is simply the
3113 number of bits from the LSB of the anonymous object to the LSB of the
3116 If the field is signed, we also do sign extension. */
3119 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3120 LONGEST bitpos
, LONGEST bitsize
)
3122 enum bfd_endian byte_order
= type_byte_order (field_type
);
3127 LONGEST read_offset
;
3129 /* Read the minimum number of bytes required; there may not be
3130 enough bytes to read an entire ULONGEST. */
3131 field_type
= check_typedef (field_type
);
3133 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3136 bytes_read
= TYPE_LENGTH (field_type
);
3137 bitsize
= 8 * bytes_read
;
3140 read_offset
= bitpos
/ 8;
3142 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3143 bytes_read
, byte_order
);
3145 /* Extract bits. See comment above. */
3147 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3148 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3150 lsbcount
= (bitpos
% 8);
3153 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3154 If the field is signed, and is negative, then sign extend. */
3156 if (bitsize
< 8 * (int) sizeof (val
))
3158 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3160 if (!TYPE_UNSIGNED (field_type
))
3162 if (val
& (valmask
^ (valmask
>> 1)))
3172 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3173 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3174 ORIGINAL_VALUE, which must not be NULL. See
3175 unpack_value_bits_as_long for more details. */
3178 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3179 LONGEST embedded_offset
, int fieldno
,
3180 const struct value
*val
, LONGEST
*result
)
3182 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3183 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3184 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3187 gdb_assert (val
!= NULL
);
3189 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3190 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3191 || !value_bits_available (val
, bit_offset
, bitsize
))
3194 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3199 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3200 object at VALADDR. See unpack_bits_as_long for more details. */
3203 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3205 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3206 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3207 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3209 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3212 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3213 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3214 the contents in DEST_VAL, zero or sign extending if the type of
3215 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3216 VAL. If the VAL's contents required to extract the bitfield from
3217 are unavailable/optimized out, DEST_VAL is correspondingly
3218 marked unavailable/optimized out. */
3221 unpack_value_bitfield (struct value
*dest_val
,
3222 LONGEST bitpos
, LONGEST bitsize
,
3223 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3224 const struct value
*val
)
3226 enum bfd_endian byte_order
;
3229 struct type
*field_type
= value_type (dest_val
);
3231 byte_order
= type_byte_order (field_type
);
3233 /* First, unpack and sign extend the bitfield as if it was wholly
3234 valid. Optimized out/unavailable bits are read as zero, but
3235 that's OK, as they'll end up marked below. If the VAL is
3236 wholly-invalid we may have skipped allocating its contents,
3237 though. See allocate_optimized_out_value. */
3238 if (valaddr
!= NULL
)
3242 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3244 store_signed_integer (value_contents_raw (dest_val
),
3245 TYPE_LENGTH (field_type
), byte_order
, num
);
3248 /* Now copy the optimized out / unavailability ranges to the right
3250 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3251 if (byte_order
== BFD_ENDIAN_BIG
)
3252 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3255 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3256 val
, src_bit_offset
, bitsize
);
3259 /* Return a new value with type TYPE, which is FIELDNO field of the
3260 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3261 of VAL. If the VAL's contents required to extract the bitfield
3262 from are unavailable/optimized out, the new value is
3263 correspondingly marked unavailable/optimized out. */
3266 value_field_bitfield (struct type
*type
, int fieldno
,
3267 const gdb_byte
*valaddr
,
3268 LONGEST embedded_offset
, const struct value
*val
)
3270 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3271 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3272 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3274 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3275 valaddr
, embedded_offset
, val
);
3280 /* Modify the value of a bitfield. ADDR points to a block of memory in
3281 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3282 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3283 indicate which bits (in target bit order) comprise the bitfield.
3284 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3285 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3288 modify_field (struct type
*type
, gdb_byte
*addr
,
3289 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3291 enum bfd_endian byte_order
= type_byte_order (type
);
3293 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3296 /* Normalize BITPOS. */
3300 /* If a negative fieldval fits in the field in question, chop
3301 off the sign extension bits. */
3302 if ((~fieldval
& ~(mask
>> 1)) == 0)
3305 /* Warn if value is too big to fit in the field in question. */
3306 if (0 != (fieldval
& ~mask
))
3308 /* FIXME: would like to include fieldval in the message, but
3309 we don't have a sprintf_longest. */
3310 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3312 /* Truncate it, otherwise adjoining fields may be corrupted. */
3316 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3317 false valgrind reports. */
3319 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3320 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3322 /* Shifting for bit field depends on endianness of the target machine. */
3323 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3324 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3326 oword
&= ~(mask
<< bitpos
);
3327 oword
|= fieldval
<< bitpos
;
3329 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3332 /* Pack NUM into BUF using a target format of TYPE. */
3335 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3337 enum bfd_endian byte_order
= type_byte_order (type
);
3340 type
= check_typedef (type
);
3341 len
= TYPE_LENGTH (type
);
3343 switch (TYPE_CODE (type
))
3345 case TYPE_CODE_RANGE
:
3346 num
-= TYPE_RANGE_DATA (type
)->bias
;
3349 case TYPE_CODE_CHAR
:
3350 case TYPE_CODE_ENUM
:
3351 case TYPE_CODE_FLAGS
:
3352 case TYPE_CODE_BOOL
:
3353 case TYPE_CODE_MEMBERPTR
:
3354 store_signed_integer (buf
, len
, byte_order
, num
);
3358 case TYPE_CODE_RVALUE_REF
:
3360 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3364 case TYPE_CODE_DECFLOAT
:
3365 target_float_from_longest (buf
, type
, num
);
3369 error (_("Unexpected type (%d) encountered for integer constant."),
3375 /* Pack NUM into BUF using a target format of TYPE. */
3378 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3381 enum bfd_endian byte_order
;
3383 type
= check_typedef (type
);
3384 len
= TYPE_LENGTH (type
);
3385 byte_order
= type_byte_order (type
);
3387 switch (TYPE_CODE (type
))
3390 case TYPE_CODE_CHAR
:
3391 case TYPE_CODE_ENUM
:
3392 case TYPE_CODE_FLAGS
:
3393 case TYPE_CODE_BOOL
:
3394 case TYPE_CODE_RANGE
:
3395 case TYPE_CODE_MEMBERPTR
:
3396 store_unsigned_integer (buf
, len
, byte_order
, num
);
3400 case TYPE_CODE_RVALUE_REF
:
3402 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3406 case TYPE_CODE_DECFLOAT
:
3407 target_float_from_ulongest (buf
, type
, num
);
3411 error (_("Unexpected type (%d) encountered "
3412 "for unsigned integer constant."),
3418 /* Convert C numbers into newly allocated values. */
3421 value_from_longest (struct type
*type
, LONGEST num
)
3423 struct value
*val
= allocate_value (type
);
3425 pack_long (value_contents_raw (val
), type
, num
);
3430 /* Convert C unsigned numbers into newly allocated values. */
3433 value_from_ulongest (struct type
*type
, ULONGEST num
)
3435 struct value
*val
= allocate_value (type
);
3437 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3443 /* Create a value representing a pointer of type TYPE to the address
3447 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3449 struct value
*val
= allocate_value (type
);
3451 store_typed_address (value_contents_raw (val
),
3452 check_typedef (type
), addr
);
3456 /* Create and return a value object of TYPE containing the value D. The
3457 TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
3458 it is converted to target format. */
3461 value_from_host_double (struct type
*type
, double d
)
3463 struct value
*value
= allocate_value (type
);
3464 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FLT
);
3465 target_float_from_host_double (value_contents_raw (value
),
3466 value_type (value
), d
);
3470 /* Create a value of type TYPE whose contents come from VALADDR, if it
3471 is non-null, and whose memory address (in the inferior) is
3472 ADDRESS. The type of the created value may differ from the passed
3473 type TYPE. Make sure to retrieve values new type after this call.
3474 Note that TYPE is not passed through resolve_dynamic_type; this is
3475 a special API intended for use only by Ada. */
3478 value_from_contents_and_address_unresolved (struct type
*type
,
3479 const gdb_byte
*valaddr
,
3484 if (valaddr
== NULL
)
3485 v
= allocate_value_lazy (type
);
3487 v
= value_from_contents (type
, valaddr
);
3488 VALUE_LVAL (v
) = lval_memory
;
3489 set_value_address (v
, address
);
3493 /* Create a value of type TYPE whose contents come from VALADDR, if it
3494 is non-null, and whose memory address (in the inferior) is
3495 ADDRESS. The type of the created value may differ from the passed
3496 type TYPE. Make sure to retrieve values new type after this call. */
3499 value_from_contents_and_address (struct type
*type
,
3500 const gdb_byte
*valaddr
,
3503 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3504 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3507 if (valaddr
== NULL
)
3508 v
= allocate_value_lazy (resolved_type
);
3510 v
= value_from_contents (resolved_type
, valaddr
);
3511 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3512 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3513 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3514 VALUE_LVAL (v
) = lval_memory
;
3515 set_value_address (v
, address
);
3519 /* Create a value of type TYPE holding the contents CONTENTS.
3520 The new value is `not_lval'. */
3523 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3525 struct value
*result
;
3527 result
= allocate_value (type
);
3528 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3532 /* Extract a value from the history file. Input will be of the form
3533 $digits or $$digits. See block comment above 'write_dollar_variable'
3537 value_from_history_ref (const char *h
, const char **endp
)
3549 /* Find length of numeral string. */
3550 for (; isdigit (h
[len
]); len
++)
3553 /* Make sure numeral string is not part of an identifier. */
3554 if (h
[len
] == '_' || isalpha (h
[len
]))
3557 /* Now collect the index value. */
3562 /* For some bizarre reason, "$$" is equivalent to "$$1",
3563 rather than to "$$0" as it ought to be! */
3571 index
= -strtol (&h
[2], &local_end
, 10);
3579 /* "$" is equivalent to "$0". */
3587 index
= strtol (&h
[1], &local_end
, 10);
3592 return access_value_history (index
);
3595 /* Get the component value (offset by OFFSET bytes) of a struct or
3596 union WHOLE. Component's type is TYPE. */
3599 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3603 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3604 v
= allocate_value_lazy (type
);
3607 v
= allocate_value (type
);
3608 value_contents_copy (v
, value_embedded_offset (v
),
3609 whole
, value_embedded_offset (whole
) + offset
,
3610 type_length_units (type
));
3612 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3613 set_value_component_location (v
, whole
);
3619 coerce_ref_if_computed (const struct value
*arg
)
3621 const struct lval_funcs
*funcs
;
3623 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3626 if (value_lval_const (arg
) != lval_computed
)
3629 funcs
= value_computed_funcs (arg
);
3630 if (funcs
->coerce_ref
== NULL
)
3633 return funcs
->coerce_ref (arg
);
3636 /* Look at value.h for description. */
3639 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3640 const struct type
*original_type
,
3641 const struct value
*original_value
)
3643 /* Re-adjust type. */
3644 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3646 /* Add embedding info. */
3647 set_value_enclosing_type (value
, enc_type
);
3648 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3650 /* We may be pointing to an object of some derived type. */
3651 return value_full_object (value
, NULL
, 0, 0, 0);
3655 coerce_ref (struct value
*arg
)
3657 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3658 struct value
*retval
;
3659 struct type
*enc_type
;
3661 retval
= coerce_ref_if_computed (arg
);
3665 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3668 enc_type
= check_typedef (value_enclosing_type (arg
));
3669 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3671 retval
= value_at_lazy (enc_type
,
3672 unpack_pointer (value_type (arg
),
3673 value_contents (arg
)));
3674 enc_type
= value_type (retval
);
3675 return readjust_indirect_value_type (retval
, enc_type
,
3676 value_type_arg_tmp
, arg
);
3680 coerce_array (struct value
*arg
)
3684 arg
= coerce_ref (arg
);
3685 type
= check_typedef (value_type (arg
));
3687 switch (TYPE_CODE (type
))
3689 case TYPE_CODE_ARRAY
:
3690 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3691 arg
= value_coerce_array (arg
);
3693 case TYPE_CODE_FUNC
:
3694 arg
= value_coerce_function (arg
);
3701 /* Return the return value convention that will be used for the
3704 enum return_value_convention
3705 struct_return_convention (struct gdbarch
*gdbarch
,
3706 struct value
*function
, struct type
*value_type
)
3708 enum type_code code
= TYPE_CODE (value_type
);
3710 if (code
== TYPE_CODE_ERROR
)
3711 error (_("Function return type unknown."));
3713 /* Probe the architecture for the return-value convention. */
3714 return gdbarch_return_value (gdbarch
, function
, value_type
,
3718 /* Return true if the function returning the specified type is using
3719 the convention of returning structures in memory (passing in the
3720 address as a hidden first parameter). */
3723 using_struct_return (struct gdbarch
*gdbarch
,
3724 struct value
*function
, struct type
*value_type
)
3726 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3727 /* A void return value is never in memory. See also corresponding
3728 code in "print_return_value". */
3731 return (struct_return_convention (gdbarch
, function
, value_type
)
3732 != RETURN_VALUE_REGISTER_CONVENTION
);
3735 /* Set the initialized field in a value struct. */
3738 set_value_initialized (struct value
*val
, int status
)
3740 val
->initialized
= status
;
3743 /* Return the initialized field in a value struct. */
3746 value_initialized (const struct value
*val
)
3748 return val
->initialized
;
3751 /* Helper for value_fetch_lazy when the value is a bitfield. */
3754 value_fetch_lazy_bitfield (struct value
*val
)
3756 gdb_assert (value_bitsize (val
) != 0);
3758 /* To read a lazy bitfield, read the entire enclosing value. This
3759 prevents reading the same block of (possibly volatile) memory once
3760 per bitfield. It would be even better to read only the containing
3761 word, but we have no way to record that just specific bits of a
3762 value have been fetched. */
3763 struct value
*parent
= value_parent (val
);
3765 if (value_lazy (parent
))
3766 value_fetch_lazy (parent
);
3768 unpack_value_bitfield (val
, value_bitpos (val
), value_bitsize (val
),
3769 value_contents_for_printing (parent
),
3770 value_offset (val
), parent
);
3773 /* Helper for value_fetch_lazy when the value is in memory. */
3776 value_fetch_lazy_memory (struct value
*val
)
3778 gdb_assert (VALUE_LVAL (val
) == lval_memory
);
3780 CORE_ADDR addr
= value_address (val
);
3781 struct type
*type
= check_typedef (value_enclosing_type (val
));
3783 if (TYPE_LENGTH (type
))
3784 read_value_memory (val
, 0, value_stack (val
),
3785 addr
, value_contents_all_raw (val
),
3786 type_length_units (type
));
3789 /* Helper for value_fetch_lazy when the value is in a register. */
3792 value_fetch_lazy_register (struct value
*val
)
3794 struct frame_info
*next_frame
;
3796 struct type
*type
= check_typedef (value_type (val
));
3797 struct value
*new_val
= val
, *mark
= value_mark ();
3799 /* Offsets are not supported here; lazy register values must
3800 refer to the entire register. */
3801 gdb_assert (value_offset (val
) == 0);
3803 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3805 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3807 next_frame
= frame_find_by_id (next_frame_id
);
3808 regnum
= VALUE_REGNUM (new_val
);
3810 gdb_assert (next_frame
!= NULL
);
3812 /* Convertible register routines are used for multi-register
3813 values and for interpretation in different types
3814 (e.g. float or int from a double register). Lazy
3815 register values should have the register's natural type,
3816 so they do not apply. */
3817 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3820 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3821 Since a "->next" operation was performed when setting
3822 this field, we do not need to perform a "next" operation
3823 again when unwinding the register. That's why
3824 frame_unwind_register_value() is called here instead of
3825 get_frame_register_value(). */
3826 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3828 /* If we get another lazy lval_register value, it means the
3829 register is found by reading it from NEXT_FRAME's next frame.
3830 frame_unwind_register_value should never return a value with
3831 the frame id pointing to NEXT_FRAME. If it does, it means we
3832 either have two consecutive frames with the same frame id
3833 in the frame chain, or some code is trying to unwind
3834 behind get_prev_frame's back (e.g., a frame unwind
3835 sniffer trying to unwind), bypassing its validations. In
3836 any case, it should always be an internal error to end up
3837 in this situation. */
3838 if (VALUE_LVAL (new_val
) == lval_register
3839 && value_lazy (new_val
)
3840 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3841 internal_error (__FILE__
, __LINE__
,
3842 _("infinite loop while fetching a register"));
3845 /* If it's still lazy (for instance, a saved register on the
3846 stack), fetch it. */
3847 if (value_lazy (new_val
))
3848 value_fetch_lazy (new_val
);
3850 /* Copy the contents and the unavailability/optimized-out
3851 meta-data from NEW_VAL to VAL. */
3852 set_value_lazy (val
, 0);
3853 value_contents_copy (val
, value_embedded_offset (val
),
3854 new_val
, value_embedded_offset (new_val
),
3855 type_length_units (type
));
3859 struct gdbarch
*gdbarch
;
3860 struct frame_info
*frame
;
3861 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3862 so that the frame level will be shown correctly. */
3863 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3864 regnum
= VALUE_REGNUM (val
);
3865 gdbarch
= get_frame_arch (frame
);
3867 fprintf_unfiltered (gdb_stdlog
,
3868 "{ value_fetch_lazy "
3869 "(frame=%d,regnum=%d(%s),...) ",
3870 frame_relative_level (frame
), regnum
,
3871 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3873 fprintf_unfiltered (gdb_stdlog
, "->");
3874 if (value_optimized_out (new_val
))
3876 fprintf_unfiltered (gdb_stdlog
, " ");
3877 val_print_optimized_out (new_val
, gdb_stdlog
);
3882 const gdb_byte
*buf
= value_contents (new_val
);
3884 if (VALUE_LVAL (new_val
) == lval_register
)
3885 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3886 VALUE_REGNUM (new_val
));
3887 else if (VALUE_LVAL (new_val
) == lval_memory
)
3888 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3890 value_address (new_val
)));
3892 fprintf_unfiltered (gdb_stdlog
, " computed");
3894 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3895 fprintf_unfiltered (gdb_stdlog
, "[");
3896 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3897 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3898 fprintf_unfiltered (gdb_stdlog
, "]");
3901 fprintf_unfiltered (gdb_stdlog
, " }\n");
3904 /* Dispose of the intermediate values. This prevents
3905 watchpoints from trying to watch the saved frame pointer. */
3906 value_free_to_mark (mark
);
3909 /* Load the actual content of a lazy value. Fetch the data from the
3910 user's process and clear the lazy flag to indicate that the data in
3911 the buffer is valid.
3913 If the value is zero-length, we avoid calling read_memory, which
3914 would abort. We mark the value as fetched anyway -- all 0 bytes of
3918 value_fetch_lazy (struct value
*val
)
3920 gdb_assert (value_lazy (val
));
3921 allocate_value_contents (val
);
3922 /* A value is either lazy, or fully fetched. The
3923 availability/validity is only established as we try to fetch a
3925 gdb_assert (val
->optimized_out
.empty ());
3926 gdb_assert (val
->unavailable
.empty ());
3927 if (value_bitsize (val
))
3928 value_fetch_lazy_bitfield (val
);
3929 else if (VALUE_LVAL (val
) == lval_memory
)
3930 value_fetch_lazy_memory (val
);
3931 else if (VALUE_LVAL (val
) == lval_register
)
3932 value_fetch_lazy_register (val
);
3933 else if (VALUE_LVAL (val
) == lval_computed
3934 && value_computed_funcs (val
)->read
!= NULL
)
3935 value_computed_funcs (val
)->read (val
);
3937 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3939 set_value_lazy (val
, 0);
3942 /* Implementation of the convenience function $_isvoid. */
3944 static struct value
*
3945 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3946 const struct language_defn
*language
,
3947 void *cookie
, int argc
, struct value
**argv
)
3952 error (_("You must provide one argument for $_isvoid."));
3954 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3956 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3959 /* Implementation of the convenience function $_cimag. Extracts the
3960 real part from a complex number. */
3962 static struct value
*
3963 creal_internal_fn (struct gdbarch
*gdbarch
,
3964 const struct language_defn
*language
,
3965 void *cookie
, int argc
, struct value
**argv
)
3968 error (_("You must provide one argument for $_creal."));
3970 value
*cval
= argv
[0];
3971 type
*ctype
= check_typedef (value_type (cval
));
3972 if (TYPE_CODE (ctype
) != TYPE_CODE_COMPLEX
)
3973 error (_("expected a complex number"));
3974 return value_from_component (cval
, TYPE_TARGET_TYPE (ctype
), 0);
3977 /* Implementation of the convenience function $_cimag. Extracts the
3978 imaginary part from a complex number. */
3980 static struct value
*
3981 cimag_internal_fn (struct gdbarch
*gdbarch
,
3982 const struct language_defn
*language
,
3983 void *cookie
, int argc
,
3984 struct value
**argv
)
3987 error (_("You must provide one argument for $_cimag."));
3989 value
*cval
= argv
[0];
3990 type
*ctype
= check_typedef (value_type (cval
));
3991 if (TYPE_CODE (ctype
) != TYPE_CODE_COMPLEX
)
3992 error (_("expected a complex number"));
3993 return value_from_component (cval
, TYPE_TARGET_TYPE (ctype
),
3994 TYPE_LENGTH (TYPE_TARGET_TYPE (ctype
)));
4001 /* Test the ranges_contain function. */
4004 test_ranges_contain ()
4006 std::vector
<range
> ranges
;
4012 ranges
.push_back (r
);
4017 ranges
.push_back (r
);
4020 SELF_CHECK (!ranges_contain (ranges
, 2, 5));
4022 SELF_CHECK (ranges_contain (ranges
, 9, 5));
4024 SELF_CHECK (ranges_contain (ranges
, 10, 2));
4026 SELF_CHECK (ranges_contain (ranges
, 10, 5));
4028 SELF_CHECK (ranges_contain (ranges
, 13, 6));
4030 SELF_CHECK (ranges_contain (ranges
, 14, 5));
4032 SELF_CHECK (!ranges_contain (ranges
, 15, 4));
4034 SELF_CHECK (!ranges_contain (ranges
, 16, 4));
4036 SELF_CHECK (ranges_contain (ranges
, 16, 6));
4038 SELF_CHECK (ranges_contain (ranges
, 21, 1));
4040 SELF_CHECK (ranges_contain (ranges
, 21, 5));
4042 SELF_CHECK (!ranges_contain (ranges
, 26, 3));
4045 /* Check that RANGES contains the same ranges as EXPECTED. */
4048 check_ranges_vector (gdb::array_view
<const range
> ranges
,
4049 gdb::array_view
<const range
> expected
)
4051 return ranges
== expected
;
4054 /* Test the insert_into_bit_range_vector function. */
4057 test_insert_into_bit_range_vector ()
4059 std::vector
<range
> ranges
;
4063 insert_into_bit_range_vector (&ranges
, 10, 5);
4064 static const range expected
[] = {
4067 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4072 insert_into_bit_range_vector (&ranges
, 11, 4);
4073 static const range expected
= {10, 5};
4074 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4077 /* [10, 14] [20, 24] */
4079 insert_into_bit_range_vector (&ranges
, 20, 5);
4080 static const range expected
[] = {
4084 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4087 /* [10, 14] [17, 24] */
4089 insert_into_bit_range_vector (&ranges
, 17, 5);
4090 static const range expected
[] = {
4094 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4097 /* [2, 8] [10, 14] [17, 24] */
4099 insert_into_bit_range_vector (&ranges
, 2, 7);
4100 static const range expected
[] = {
4105 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4108 /* [2, 14] [17, 24] */
4110 insert_into_bit_range_vector (&ranges
, 9, 1);
4111 static const range expected
[] = {
4115 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4118 /* [2, 14] [17, 24] */
4120 insert_into_bit_range_vector (&ranges
, 9, 1);
4121 static const range expected
[] = {
4125 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4130 insert_into_bit_range_vector (&ranges
, 4, 30);
4131 static const range expected
= {2, 32};
4132 SELF_CHECK (check_ranges_vector (ranges
, expected
));
4136 } /* namespace selftests */
4137 #endif /* GDB_SELF_TEST */
4140 _initialize_values (void)
4142 add_cmd ("convenience", no_class
, show_convenience
, _("\
4143 Debugger convenience (\"$foo\") variables and functions.\n\
4144 Convenience variables are created when you assign them values;\n\
4145 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4147 A few convenience variables are given values automatically:\n\
4148 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4149 \"$__\" holds the contents of the last address examined with \"x\"."
4152 Convenience functions are defined via the Python API."
4155 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4157 add_cmd ("values", no_set_class
, show_values
, _("\
4158 Elements of value history around item number IDX (or last ten)."),
4161 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4162 Initialize a convenience variable if necessary.\n\
4163 init-if-undefined VARIABLE = EXPRESSION\n\
4164 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4165 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4166 VARIABLE is already initialized."));
4168 add_prefix_cmd ("function", no_class
, function_command
, _("\
4169 Placeholder command for showing help on convenience functions."),
4170 &functionlist
, "function ", 0, &cmdlist
);
4172 add_internal_function ("_isvoid", _("\
4173 Check whether an expression is void.\n\
4174 Usage: $_isvoid (expression)\n\
4175 Return 1 if the expression is void, zero otherwise."),
4176 isvoid_internal_fn
, NULL
);
4178 add_internal_function ("_creal", _("\
4179 Extract the real part of a complex number.\n\
4180 Usage: $_creal (expression)\n\
4181 Return the real part of a complex number, the type depends on the\n\
4182 type of a complex number."),
4183 creal_internal_fn
, NULL
);
4185 add_internal_function ("_cimag", _("\
4186 Extract the imaginary part of a complex number.\n\
4187 Usage: $_cimag (expression)\n\
4188 Return the imaginary part of a complex number, the type depends on the\n\
4189 type of a complex number."),
4190 cimag_internal_fn
, NULL
);
4192 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4193 class_support
, &max_value_size
, _("\
4194 Set maximum sized value gdb will load from the inferior."), _("\
4195 Show maximum sized value gdb will load from the inferior."), _("\
4196 Use this to control the maximum size, in bytes, of a value that gdb\n\
4197 will load from the inferior. Setting this value to 'unlimited'\n\
4198 disables checking.\n\
4199 Setting this does not invalidate already allocated values, it only\n\
4200 prevents future values, larger than this size, from being allocated."),
4202 show_max_value_size
,
4203 &setlist
, &showlist
);
4205 selftests::register_test ("ranges_contain", selftests::test_ranges_contain
);
4206 selftests::register_test ("insert_into_bit_range_vector",
4207 selftests::test_insert_into_bit_range_vector
);
4216 all_values
.clear ();