1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2017 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"
37 #include "cli/cli-decode.h"
38 #include "extension.h"
40 #include "tracepoint.h"
42 #include "user-regs.h"
44 #include "completer.h"
46 /* Definition of a user function. */
47 struct internal_function
49 /* The name of the function. It is a bit odd to have this in the
50 function itself -- the user might use a differently-named
51 convenience variable to hold the function. */
55 internal_function_fn handler
;
57 /* User data for the handler. */
61 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
65 /* Lowest offset in the range. */
68 /* Length of the range. */
72 typedef struct range range_s
;
76 /* Returns true if the ranges defined by [offset1, offset1+len1) and
77 [offset2, offset2+len2) overlap. */
80 ranges_overlap (LONGEST offset1
, LONGEST len1
,
81 LONGEST offset2
, LONGEST len2
)
85 l
= std::max (offset1
, offset2
);
86 h
= std::min (offset1
+ len1
, offset2
+ len2
);
90 /* Returns true if the first argument is strictly less than the
91 second, useful for VEC_lower_bound. We keep ranges sorted by
92 offset and coalesce overlapping and contiguous ranges, so this just
93 compares the starting offset. */
96 range_lessthan (const range_s
*r1
, const range_s
*r2
)
98 return r1
->offset
< r2
->offset
;
101 /* Returns true if RANGES contains any range that overlaps [OFFSET,
105 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
110 what
.offset
= offset
;
111 what
.length
= length
;
113 /* We keep ranges sorted by offset and coalesce overlapping and
114 contiguous ranges, so to check if a range list contains a given
115 range, we can do a binary search for the position the given range
116 would be inserted if we only considered the starting OFFSET of
117 ranges. We call that position I. Since we also have LENGTH to
118 care for (this is a range afterall), we need to check if the
119 _previous_ range overlaps the I range. E.g.,
123 |---| |---| |------| ... |--|
128 In the case above, the binary search would return `I=1', meaning,
129 this OFFSET should be inserted at position 1, and the current
130 position 1 should be pushed further (and before 2). But, `0'
133 Then we need to check if the I range overlaps the I range itself.
138 |---| |---| |-------| ... |--|
144 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
148 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
150 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
154 if (i
< VEC_length (range_s
, ranges
))
156 struct range
*r
= VEC_index (range_s
, ranges
, i
);
158 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
165 static struct cmd_list_element
*functionlist
;
167 /* Note that the fields in this structure are arranged to save a bit
172 /* Type of value; either not an lval, or one of the various
173 different possible kinds of lval. */
176 /* Is it modifiable? Only relevant if lval != not_lval. */
177 unsigned int modifiable
: 1;
179 /* If zero, contents of this value are in the contents field. If
180 nonzero, contents are in inferior. If the lval field is lval_memory,
181 the contents are in inferior memory at location.address plus offset.
182 The lval field may also be lval_register.
184 WARNING: This field is used by the code which handles watchpoints
185 (see breakpoint.c) to decide whether a particular value can be
186 watched by hardware watchpoints. If the lazy flag is set for
187 some member of a value chain, it is assumed that this member of
188 the chain doesn't need to be watched as part of watching the
189 value itself. This is how GDB avoids watching the entire struct
190 or array when the user wants to watch a single struct member or
191 array element. If you ever change the way lazy flag is set and
192 reset, be sure to consider this use as well! */
193 unsigned int lazy
: 1;
195 /* If value is a variable, is it initialized or not. */
196 unsigned int initialized
: 1;
198 /* If value is from the stack. If this is set, read_stack will be
199 used instead of read_memory to enable extra caching. */
200 unsigned int stack
: 1;
202 /* If the value has been released. */
203 unsigned int released
: 1;
205 /* Location of value (if lval). */
208 /* If lval == lval_memory, this is the address in the inferior */
211 /*If lval == lval_register, the value is from a register. */
214 /* Register number. */
216 /* Frame ID of "next" frame to which a register value is relative.
217 If the register value is found relative to frame F, then the
218 frame id of F->next will be stored in next_frame_id. */
219 struct frame_id next_frame_id
;
222 /* Pointer to internal variable. */
223 struct internalvar
*internalvar
;
225 /* Pointer to xmethod worker. */
226 struct xmethod_worker
*xm_worker
;
228 /* If lval == lval_computed, this is a set of function pointers
229 to use to access and describe the value, and a closure pointer
233 /* Functions to call. */
234 const struct lval_funcs
*funcs
;
236 /* Closure for those functions to use. */
241 /* Describes offset of a value within lval of a structure in target
242 addressable memory units. Note also the member embedded_offset
246 /* Only used for bitfields; number of bits contained in them. */
249 /* Only used for bitfields; position of start of field. For
250 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
251 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
254 /* The number of references to this value. When a value is created,
255 the value chain holds a reference, so REFERENCE_COUNT is 1. If
256 release_value is called, this value is removed from the chain but
257 the caller of release_value now has a reference to this value.
258 The caller must arrange for a call to value_free later. */
261 /* Only used for bitfields; the containing value. This allows a
262 single read from the target when displaying multiple
264 struct value
*parent
;
266 /* Type of the value. */
269 /* If a value represents a C++ object, then the `type' field gives
270 the object's compile-time type. If the object actually belongs
271 to some class derived from `type', perhaps with other base
272 classes and additional members, then `type' is just a subobject
273 of the real thing, and the full object is probably larger than
274 `type' would suggest.
276 If `type' is a dynamic class (i.e. one with a vtable), then GDB
277 can actually determine the object's run-time type by looking at
278 the run-time type information in the vtable. When this
279 information is available, we may elect to read in the entire
280 object, for several reasons:
282 - When printing the value, the user would probably rather see the
283 full object, not just the limited portion apparent from the
286 - If `type' has virtual base classes, then even printing `type'
287 alone may require reaching outside the `type' portion of the
288 object to wherever the virtual base class has been stored.
290 When we store the entire object, `enclosing_type' is the run-time
291 type -- the complete object -- and `embedded_offset' is the
292 offset of `type' within that larger type, in target addressable memory
293 units. The value_contents() macro takes `embedded_offset' into account,
294 so most GDB code continues to see the `type' portion of the value, just
295 as the inferior would.
297 If `type' is a pointer to an object, then `enclosing_type' is a
298 pointer to the object's run-time type, and `pointed_to_offset' is
299 the offset in target addressable memory units from the full object
300 to the pointed-to object -- that is, the value `embedded_offset' would
301 have if we followed the pointer and fetched the complete object.
302 (I don't really see the point. Why not just determine the
303 run-time type when you indirect, and avoid the special case? The
304 contents don't matter until you indirect anyway.)
306 If we're not doing anything fancy, `enclosing_type' is equal to
307 `type', and `embedded_offset' is zero, so everything works
309 struct type
*enclosing_type
;
310 LONGEST embedded_offset
;
311 LONGEST pointed_to_offset
;
313 /* Values are stored in a chain, so that they can be deleted easily
314 over calls to the inferior. Values assigned to internal
315 variables, put into the value history or exposed to Python are
316 taken off this list. */
319 /* Actual contents of the value. Target byte-order. NULL or not
320 valid if lazy is nonzero. */
323 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
324 rather than available, since the common and default case is for a
325 value to be available. This is filled in at value read time.
326 The unavailable ranges are tracked in bits. Note that a contents
327 bit that has been optimized out doesn't really exist in the
328 program, so it can't be marked unavailable either. */
329 VEC(range_s
) *unavailable
;
331 /* Likewise, but for optimized out contents (a chunk of the value of
332 a variable that does not actually exist in the program). If LVAL
333 is lval_register, this is a register ($pc, $sp, etc., never a
334 program variable) that has not been saved in the frame. Not
335 saved registers and optimized-out program variables values are
336 treated pretty much the same, except not-saved registers have a
337 different string representation and related error strings. */
338 VEC(range_s
) *optimized_out
;
344 get_value_arch (const struct value
*value
)
346 return get_type_arch (value_type (value
));
350 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
352 gdb_assert (!value
->lazy
);
354 return !ranges_contain (value
->unavailable
, offset
, length
);
358 value_bytes_available (const struct value
*value
,
359 LONGEST offset
, LONGEST length
)
361 return value_bits_available (value
,
362 offset
* TARGET_CHAR_BIT
,
363 length
* TARGET_CHAR_BIT
);
367 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
369 gdb_assert (!value
->lazy
);
371 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
375 value_entirely_available (struct value
*value
)
377 /* We can only tell whether the whole value is available when we try
380 value_fetch_lazy (value
);
382 if (VEC_empty (range_s
, value
->unavailable
))
387 /* Returns true if VALUE is entirely covered by RANGES. If the value
388 is lazy, it'll be read now. Note that RANGE is a pointer to
389 pointer because reading the value might change *RANGE. */
392 value_entirely_covered_by_range_vector (struct value
*value
,
393 VEC(range_s
) **ranges
)
395 /* We can only tell whether the whole value is optimized out /
396 unavailable when we try to read it. */
398 value_fetch_lazy (value
);
400 if (VEC_length (range_s
, *ranges
) == 1)
402 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
405 && t
->length
== (TARGET_CHAR_BIT
406 * TYPE_LENGTH (value_enclosing_type (value
))))
414 value_entirely_unavailable (struct value
*value
)
416 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
420 value_entirely_optimized_out (struct value
*value
)
422 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
425 /* Insert into the vector pointed to by VECTORP the bit range starting of
426 OFFSET bits, and extending for the next LENGTH bits. */
429 insert_into_bit_range_vector (VEC(range_s
) **vectorp
,
430 LONGEST offset
, LONGEST length
)
435 /* Insert the range sorted. If there's overlap or the new range
436 would be contiguous with an existing range, merge. */
438 newr
.offset
= offset
;
439 newr
.length
= length
;
441 /* Do a binary search for the position the given range would be
442 inserted if we only considered the starting OFFSET of ranges.
443 Call that position I. Since we also have LENGTH to care for
444 (this is a range afterall), we need to check if the _previous_
445 range overlaps the I range. E.g., calling R the new range:
447 #1 - overlaps with previous
451 |---| |---| |------| ... |--|
456 In the case #1 above, the binary search would return `I=1',
457 meaning, this OFFSET should be inserted at position 1, and the
458 current position 1 should be pushed further (and become 2). But,
459 note that `0' overlaps with R, so we want to merge them.
461 A similar consideration needs to be taken if the new range would
462 be contiguous with the previous range:
464 #2 - contiguous with previous
468 |--| |---| |------| ... |--|
473 If there's no overlap with the previous range, as in:
475 #3 - not overlapping and not contiguous
479 |--| |---| |------| ... |--|
486 #4 - R is the range with lowest offset
490 |--| |---| |------| ... |--|
495 ... we just push the new range to I.
497 All the 4 cases above need to consider that the new range may
498 also overlap several of the ranges that follow, or that R may be
499 contiguous with the following range, and merge. E.g.,
501 #5 - overlapping following ranges
504 |------------------------|
505 |--| |---| |------| ... |--|
514 |--| |---| |------| ... |--|
521 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
524 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
526 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
529 ULONGEST l
= std::min (bef
->offset
, offset
);
530 ULONGEST h
= std::max (bef
->offset
+ bef
->length
, offset
+ length
);
536 else if (offset
== bef
->offset
+ bef
->length
)
539 bef
->length
+= length
;
545 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
551 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
554 /* Check whether the ranges following the one we've just added or
555 touched can be folded in (#5 above). */
556 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
563 /* Get the range we just touched. */
564 t
= VEC_index (range_s
, *vectorp
, i
);
568 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
569 if (r
->offset
<= t
->offset
+ t
->length
)
573 l
= std::min (t
->offset
, r
->offset
);
574 h
= std::max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
583 /* If we couldn't merge this one, we won't be able to
584 merge following ones either, since the ranges are
585 always sorted by OFFSET. */
590 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
595 mark_value_bits_unavailable (struct value
*value
,
596 LONGEST offset
, LONGEST length
)
598 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
602 mark_value_bytes_unavailable (struct value
*value
,
603 LONGEST offset
, LONGEST length
)
605 mark_value_bits_unavailable (value
,
606 offset
* TARGET_CHAR_BIT
,
607 length
* TARGET_CHAR_BIT
);
610 /* Find the first range in RANGES that overlaps the range defined by
611 OFFSET and LENGTH, starting at element POS in the RANGES vector,
612 Returns the index into RANGES where such overlapping range was
613 found, or -1 if none was found. */
616 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
617 LONGEST offset
, LONGEST length
)
622 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
623 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
629 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
630 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
633 It must always be the case that:
634 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
636 It is assumed that memory can be accessed from:
637 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
639 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
640 / TARGET_CHAR_BIT) */
642 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
643 const gdb_byte
*ptr2
, size_t offset2_bits
,
646 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
647 == offset2_bits
% TARGET_CHAR_BIT
);
649 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
652 gdb_byte mask
, b1
, b2
;
654 /* The offset from the base pointers PTR1 and PTR2 is not a complete
655 number of bytes. A number of bits up to either the next exact
656 byte boundary, or LENGTH_BITS (which ever is sooner) will be
658 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
659 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
660 mask
= (1 << bits
) - 1;
662 if (length_bits
< bits
)
664 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
668 /* Now load the two bytes and mask off the bits we care about. */
669 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
670 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
675 /* Now update the length and offsets to take account of the bits
676 we've just compared. */
678 offset1_bits
+= bits
;
679 offset2_bits
+= bits
;
682 if (length_bits
% TARGET_CHAR_BIT
!= 0)
686 gdb_byte mask
, b1
, b2
;
688 /* The length is not an exact number of bytes. After the previous
689 IF.. block then the offsets are byte aligned, or the
690 length is zero (in which case this code is not reached). Compare
691 a number of bits at the end of the region, starting from an exact
693 bits
= length_bits
% TARGET_CHAR_BIT
;
694 o1
= offset1_bits
+ length_bits
- bits
;
695 o2
= offset2_bits
+ length_bits
- bits
;
697 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
698 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
700 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
701 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
703 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
704 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
714 /* We've now taken care of any stray "bits" at the start, or end of
715 the region to compare, the remainder can be covered with a simple
717 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
718 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
719 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
721 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
722 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
723 length_bits
/ TARGET_CHAR_BIT
);
726 /* Length is zero, regions match. */
730 /* Helper struct for find_first_range_overlap_and_match and
731 value_contents_bits_eq. Keep track of which slot of a given ranges
732 vector have we last looked at. */
734 struct ranges_and_idx
737 VEC(range_s
) *ranges
;
739 /* The range we've last found in RANGES. Given ranges are sorted,
740 we can start the next lookup here. */
744 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
745 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
746 ranges starting at OFFSET2 bits. Return true if the ranges match
747 and fill in *L and *H with the overlapping window relative to
748 (both) OFFSET1 or OFFSET2. */
751 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
752 struct ranges_and_idx
*rp2
,
753 LONGEST offset1
, LONGEST offset2
,
754 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
756 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
758 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
761 if (rp1
->idx
== -1 && rp2
->idx
== -1)
767 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
775 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
776 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
778 /* Get the unavailable windows intersected by the incoming
779 ranges. The first and last ranges that overlap the argument
780 range may be wider than said incoming arguments ranges. */
781 l1
= std::max (offset1
, r1
->offset
);
782 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
784 l2
= std::max (offset2
, r2
->offset
);
785 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
787 /* Make them relative to the respective start offsets, so we can
788 compare them for equality. */
795 /* Different ranges, no match. */
796 if (l1
!= l2
|| h1
!= h2
)
805 /* Helper function for value_contents_eq. The only difference is that
806 this function is bit rather than byte based.
808 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
809 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
810 Return true if the available bits match. */
813 value_contents_bits_eq (const struct value
*val1
, int offset1
,
814 const struct value
*val2
, int offset2
,
817 /* Each array element corresponds to a ranges source (unavailable,
818 optimized out). '1' is for VAL1, '2' for VAL2. */
819 struct ranges_and_idx rp1
[2], rp2
[2];
821 /* See function description in value.h. */
822 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
824 /* We shouldn't be trying to compare past the end of the values. */
825 gdb_assert (offset1
+ length
826 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
827 gdb_assert (offset2
+ length
828 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
830 memset (&rp1
, 0, sizeof (rp1
));
831 memset (&rp2
, 0, sizeof (rp2
));
832 rp1
[0].ranges
= val1
->unavailable
;
833 rp2
[0].ranges
= val2
->unavailable
;
834 rp1
[1].ranges
= val1
->optimized_out
;
835 rp2
[1].ranges
= val2
->optimized_out
;
839 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
842 for (i
= 0; i
< 2; i
++)
844 ULONGEST l_tmp
, h_tmp
;
846 /* The contents only match equal if the invalid/unavailable
847 contents ranges match as well. */
848 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
849 offset1
, offset2
, length
,
853 /* We're interested in the lowest/first range found. */
854 if (i
== 0 || l_tmp
< l
)
861 /* Compare the available/valid contents. */
862 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
863 val2
->contents
, offset2
, l
) != 0)
875 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
876 const struct value
*val2
, LONGEST offset2
,
879 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
880 val2
, offset2
* TARGET_CHAR_BIT
,
881 length
* TARGET_CHAR_BIT
);
884 /* Prototypes for local functions. */
886 static void show_values (char *, int);
889 /* The value-history records all the values printed
890 by print commands during this session. Each chunk
891 records 60 consecutive values. The first chunk on
892 the chain records the most recent values.
893 The total number of values is in value_history_count. */
895 #define VALUE_HISTORY_CHUNK 60
897 struct value_history_chunk
899 struct value_history_chunk
*next
;
900 struct value
*values
[VALUE_HISTORY_CHUNK
];
903 /* Chain of chunks now in use. */
905 static struct value_history_chunk
*value_history_chain
;
907 static int value_history_count
; /* Abs number of last entry stored. */
910 /* List of all value objects currently allocated
911 (except for those released by calls to release_value)
912 This is so they can be freed after each command. */
914 static struct value
*all_values
;
916 /* Allocate a lazy value for type TYPE. Its actual content is
917 "lazily" allocated too: the content field of the return value is
918 NULL; it will be allocated when it is fetched from the target. */
921 allocate_value_lazy (struct type
*type
)
925 /* Call check_typedef on our type to make sure that, if TYPE
926 is a TYPE_CODE_TYPEDEF, its length is set to the length
927 of the target type instead of zero. However, we do not
928 replace the typedef type by the target type, because we want
929 to keep the typedef in order to be able to set the VAL's type
930 description correctly. */
931 check_typedef (type
);
933 val
= XCNEW (struct value
);
934 val
->contents
= NULL
;
935 val
->next
= all_values
;
938 val
->enclosing_type
= type
;
939 VALUE_LVAL (val
) = not_lval
;
940 val
->location
.address
= 0;
945 val
->embedded_offset
= 0;
946 val
->pointed_to_offset
= 0;
948 val
->initialized
= 1; /* Default to initialized. */
950 /* Values start out on the all_values chain. */
951 val
->reference_count
= 1;
956 /* The maximum size, in bytes, that GDB will try to allocate for a value.
957 The initial value of 64k was not selected for any specific reason, it is
958 just a reasonable starting point. */
960 static int max_value_size
= 65536; /* 64k bytes */
962 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
963 LONGEST, otherwise GDB will not be able to parse integer values from the
964 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
965 be unable to parse "set max-value-size 2".
967 As we want a consistent GDB experience across hosts with different sizes
968 of LONGEST, this arbitrary minimum value was selected, so long as this
969 is bigger than LONGEST on all GDB supported hosts we're fine. */
971 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
972 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
974 /* Implement the "set max-value-size" command. */
977 set_max_value_size (char *args
, int from_tty
,
978 struct cmd_list_element
*c
)
980 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
982 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
984 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
985 error (_("max-value-size set too low, increasing to %d bytes"),
990 /* Implement the "show max-value-size" command. */
993 show_max_value_size (struct ui_file
*file
, int from_tty
,
994 struct cmd_list_element
*c
, const char *value
)
996 if (max_value_size
== -1)
997 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
999 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
1003 /* Called before we attempt to allocate or reallocate a buffer for the
1004 contents of a value. TYPE is the type of the value for which we are
1005 allocating the buffer. If the buffer is too large (based on the user
1006 controllable setting) then throw an error. If this function returns
1007 then we should attempt to allocate the buffer. */
1010 check_type_length_before_alloc (const struct type
*type
)
1012 unsigned int length
= TYPE_LENGTH (type
);
1014 if (max_value_size
> -1 && length
> max_value_size
)
1016 if (TYPE_NAME (type
) != NULL
)
1017 error (_("value of type `%s' requires %u bytes, which is more "
1018 "than max-value-size"), TYPE_NAME (type
), length
);
1020 error (_("value requires %u bytes, which is more than "
1021 "max-value-size"), length
);
1025 /* Allocate the contents of VAL if it has not been allocated yet. */
1028 allocate_value_contents (struct value
*val
)
1032 check_type_length_before_alloc (val
->enclosing_type
);
1034 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1038 /* Allocate a value and its contents for type TYPE. */
1041 allocate_value (struct type
*type
)
1043 struct value
*val
= allocate_value_lazy (type
);
1045 allocate_value_contents (val
);
1050 /* Allocate a value that has the correct length
1051 for COUNT repetitions of type TYPE. */
1054 allocate_repeat_value (struct type
*type
, int count
)
1056 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1057 /* FIXME-type-allocation: need a way to free this type when we are
1059 struct type
*array_type
1060 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1062 return allocate_value (array_type
);
1066 allocate_computed_value (struct type
*type
,
1067 const struct lval_funcs
*funcs
,
1070 struct value
*v
= allocate_value_lazy (type
);
1072 VALUE_LVAL (v
) = lval_computed
;
1073 v
->location
.computed
.funcs
= funcs
;
1074 v
->location
.computed
.closure
= closure
;
1079 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1082 allocate_optimized_out_value (struct type
*type
)
1084 struct value
*retval
= allocate_value_lazy (type
);
1086 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1087 set_value_lazy (retval
, 0);
1091 /* Accessor methods. */
1094 value_next (const struct value
*value
)
1100 value_type (const struct value
*value
)
1105 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1111 value_offset (const struct value
*value
)
1113 return value
->offset
;
1116 set_value_offset (struct value
*value
, LONGEST offset
)
1118 value
->offset
= offset
;
1122 value_bitpos (const struct value
*value
)
1124 return value
->bitpos
;
1127 set_value_bitpos (struct value
*value
, LONGEST bit
)
1129 value
->bitpos
= bit
;
1133 value_bitsize (const struct value
*value
)
1135 return value
->bitsize
;
1138 set_value_bitsize (struct value
*value
, LONGEST bit
)
1140 value
->bitsize
= bit
;
1144 value_parent (const struct value
*value
)
1146 return value
->parent
;
1152 set_value_parent (struct value
*value
, struct value
*parent
)
1154 struct value
*old
= value
->parent
;
1156 value
->parent
= parent
;
1158 value_incref (parent
);
1163 value_contents_raw (struct value
*value
)
1165 struct gdbarch
*arch
= get_value_arch (value
);
1166 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1168 allocate_value_contents (value
);
1169 return value
->contents
+ value
->embedded_offset
* unit_size
;
1173 value_contents_all_raw (struct value
*value
)
1175 allocate_value_contents (value
);
1176 return value
->contents
;
1180 value_enclosing_type (const struct value
*value
)
1182 return value
->enclosing_type
;
1185 /* Look at value.h for description. */
1188 value_actual_type (struct value
*value
, int resolve_simple_types
,
1189 int *real_type_found
)
1191 struct value_print_options opts
;
1192 struct type
*result
;
1194 get_user_print_options (&opts
);
1196 if (real_type_found
)
1197 *real_type_found
= 0;
1198 result
= value_type (value
);
1199 if (opts
.objectprint
)
1201 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1202 fetch its rtti type. */
1203 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1204 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1206 && !value_optimized_out (value
))
1208 struct type
*real_type
;
1210 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1213 if (real_type_found
)
1214 *real_type_found
= 1;
1218 else if (resolve_simple_types
)
1220 if (real_type_found
)
1221 *real_type_found
= 1;
1222 result
= value_enclosing_type (value
);
1230 error_value_optimized_out (void)
1232 error (_("value has been optimized out"));
1236 require_not_optimized_out (const struct value
*value
)
1238 if (!VEC_empty (range_s
, value
->optimized_out
))
1240 if (value
->lval
== lval_register
)
1241 error (_("register has not been saved in frame"));
1243 error_value_optimized_out ();
1248 require_available (const struct value
*value
)
1250 if (!VEC_empty (range_s
, value
->unavailable
))
1251 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1255 value_contents_for_printing (struct value
*value
)
1258 value_fetch_lazy (value
);
1259 return value
->contents
;
1263 value_contents_for_printing_const (const struct value
*value
)
1265 gdb_assert (!value
->lazy
);
1266 return value
->contents
;
1270 value_contents_all (struct value
*value
)
1272 const gdb_byte
*result
= value_contents_for_printing (value
);
1273 require_not_optimized_out (value
);
1274 require_available (value
);
1278 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1279 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1282 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1283 VEC (range_s
) *src_range
, int src_bit_offset
,
1289 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1293 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1294 h
= std::min (r
->offset
+ r
->length
,
1295 (LONGEST
) src_bit_offset
+ bit_length
);
1298 insert_into_bit_range_vector (dst_range
,
1299 dst_bit_offset
+ (l
- src_bit_offset
),
1304 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1305 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1308 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1309 const struct value
*src
, int src_bit_offset
,
1312 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1313 src
->unavailable
, src_bit_offset
,
1315 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1316 src
->optimized_out
, src_bit_offset
,
1320 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1321 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1322 contents, starting at DST_OFFSET. If unavailable contents are
1323 being copied from SRC, the corresponding DST contents are marked
1324 unavailable accordingly. Neither DST nor SRC may be lazy
1327 It is assumed the contents of DST in the [DST_OFFSET,
1328 DST_OFFSET+LENGTH) range are wholly available. */
1331 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1332 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1334 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1335 struct gdbarch
*arch
= get_value_arch (src
);
1336 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1338 /* A lazy DST would make that this copy operation useless, since as
1339 soon as DST's contents were un-lazied (by a later value_contents
1340 call, say), the contents would be overwritten. A lazy SRC would
1341 mean we'd be copying garbage. */
1342 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1344 /* The overwritten DST range gets unavailability ORed in, not
1345 replaced. Make sure to remember to implement replacing if it
1346 turns out actually necessary. */
1347 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1348 gdb_assert (!value_bits_any_optimized_out (dst
,
1349 TARGET_CHAR_BIT
* dst_offset
,
1350 TARGET_CHAR_BIT
* length
));
1352 /* Copy the data. */
1353 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1354 value_contents_all_raw (src
) + src_offset
* unit_size
,
1355 length
* unit_size
);
1357 /* Copy the meta-data, adjusted. */
1358 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1359 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1360 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1362 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1363 src
, src_bit_offset
,
1367 /* Copy LENGTH bytes of SRC value's (all) contents
1368 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1369 (all) contents, starting at DST_OFFSET. If unavailable contents
1370 are being copied from SRC, the corresponding DST contents are
1371 marked unavailable accordingly. DST must not be lazy. If SRC is
1372 lazy, it will be fetched now.
1374 It is assumed the contents of DST in the [DST_OFFSET,
1375 DST_OFFSET+LENGTH) range are wholly available. */
1378 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1379 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1382 value_fetch_lazy (src
);
1384 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1388 value_lazy (const struct value
*value
)
1394 set_value_lazy (struct value
*value
, int val
)
1400 value_stack (const struct value
*value
)
1402 return value
->stack
;
1406 set_value_stack (struct value
*value
, int val
)
1412 value_contents (struct value
*value
)
1414 const gdb_byte
*result
= value_contents_writeable (value
);
1415 require_not_optimized_out (value
);
1416 require_available (value
);
1421 value_contents_writeable (struct value
*value
)
1424 value_fetch_lazy (value
);
1425 return value_contents_raw (value
);
1429 value_optimized_out (struct value
*value
)
1431 /* We can only know if a value is optimized out once we have tried to
1433 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1437 value_fetch_lazy (value
);
1439 CATCH (ex
, RETURN_MASK_ERROR
)
1441 /* Fall back to checking value->optimized_out. */
1446 return !VEC_empty (range_s
, value
->optimized_out
);
1449 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1450 the following LENGTH bytes. */
1453 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1455 mark_value_bits_optimized_out (value
,
1456 offset
* TARGET_CHAR_BIT
,
1457 length
* TARGET_CHAR_BIT
);
1463 mark_value_bits_optimized_out (struct value
*value
,
1464 LONGEST offset
, LONGEST length
)
1466 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1470 value_bits_synthetic_pointer (const struct value
*value
,
1471 LONGEST offset
, LONGEST length
)
1473 if (value
->lval
!= lval_computed
1474 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1476 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1482 value_embedded_offset (const struct value
*value
)
1484 return value
->embedded_offset
;
1488 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1490 value
->embedded_offset
= val
;
1494 value_pointed_to_offset (const struct value
*value
)
1496 return value
->pointed_to_offset
;
1500 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1502 value
->pointed_to_offset
= val
;
1505 const struct lval_funcs
*
1506 value_computed_funcs (const struct value
*v
)
1508 gdb_assert (value_lval_const (v
) == lval_computed
);
1510 return v
->location
.computed
.funcs
;
1514 value_computed_closure (const struct value
*v
)
1516 gdb_assert (v
->lval
== lval_computed
);
1518 return v
->location
.computed
.closure
;
1522 deprecated_value_lval_hack (struct value
*value
)
1524 return &value
->lval
;
1528 value_lval_const (const struct value
*value
)
1534 value_address (const struct value
*value
)
1536 if (value
->lval
!= lval_memory
)
1538 if (value
->parent
!= NULL
)
1539 return value_address (value
->parent
) + value
->offset
;
1540 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1542 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1543 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1546 return value
->location
.address
+ value
->offset
;
1550 value_raw_address (const struct value
*value
)
1552 if (value
->lval
!= lval_memory
)
1554 return value
->location
.address
;
1558 set_value_address (struct value
*value
, CORE_ADDR addr
)
1560 gdb_assert (value
->lval
== lval_memory
);
1561 value
->location
.address
= addr
;
1564 struct internalvar
**
1565 deprecated_value_internalvar_hack (struct value
*value
)
1567 return &value
->location
.internalvar
;
1571 deprecated_value_next_frame_id_hack (struct value
*value
)
1573 gdb_assert (value
->lval
== lval_register
);
1574 return &value
->location
.reg
.next_frame_id
;
1578 deprecated_value_regnum_hack (struct value
*value
)
1580 gdb_assert (value
->lval
== lval_register
);
1581 return &value
->location
.reg
.regnum
;
1585 deprecated_value_modifiable (const struct value
*value
)
1587 return value
->modifiable
;
1590 /* Return a mark in the value chain. All values allocated after the
1591 mark is obtained (except for those released) are subject to being freed
1592 if a subsequent value_free_to_mark is passed the mark. */
1599 /* Take a reference to VAL. VAL will not be deallocated until all
1600 references are released. */
1603 value_incref (struct value
*val
)
1605 val
->reference_count
++;
1608 /* Release a reference to VAL, which was acquired with value_incref.
1609 This function is also called to deallocate values from the value
1613 value_free (struct value
*val
)
1617 gdb_assert (val
->reference_count
> 0);
1618 val
->reference_count
--;
1619 if (val
->reference_count
> 0)
1622 /* If there's an associated parent value, drop our reference to
1624 if (val
->parent
!= NULL
)
1625 value_free (val
->parent
);
1627 if (VALUE_LVAL (val
) == lval_computed
)
1629 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1631 if (funcs
->free_closure
)
1632 funcs
->free_closure (val
);
1634 else if (VALUE_LVAL (val
) == lval_xcallable
)
1635 free_xmethod_worker (val
->location
.xm_worker
);
1637 xfree (val
->contents
);
1638 VEC_free (range_s
, val
->unavailable
);
1643 /* Free all values allocated since MARK was obtained by value_mark
1644 (except for those released). */
1646 value_free_to_mark (const struct value
*mark
)
1651 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1660 /* Free all the values that have been allocated (except for those released).
1661 Call after each command, successful or not.
1662 In practice this is called before each command, which is sufficient. */
1665 free_all_values (void)
1670 for (val
= all_values
; val
; val
= next
)
1680 /* Frees all the elements in a chain of values. */
1683 free_value_chain (struct value
*v
)
1689 next
= value_next (v
);
1694 /* Remove VAL from the chain all_values
1695 so it will not be freed automatically. */
1698 release_value (struct value
*val
)
1702 if (all_values
== val
)
1704 all_values
= val
->next
;
1710 for (v
= all_values
; v
; v
= v
->next
)
1714 v
->next
= val
->next
;
1722 /* If the value is not already released, release it.
1723 If the value is already released, increment its reference count.
1724 That is, this function ensures that the value is released from the
1725 value chain and that the caller owns a reference to it. */
1728 release_value_or_incref (struct value
*val
)
1733 release_value (val
);
1736 /* Release all values up to mark */
1738 value_release_to_mark (const struct value
*mark
)
1743 for (val
= next
= all_values
; next
; next
= next
->next
)
1745 if (next
->next
== mark
)
1747 all_values
= next
->next
;
1757 /* Return a copy of the value ARG.
1758 It contains the same contents, for same memory address,
1759 but it's a different block of storage. */
1762 value_copy (struct value
*arg
)
1764 struct type
*encl_type
= value_enclosing_type (arg
);
1767 if (value_lazy (arg
))
1768 val
= allocate_value_lazy (encl_type
);
1770 val
= allocate_value (encl_type
);
1771 val
->type
= arg
->type
;
1772 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1773 val
->location
= arg
->location
;
1774 val
->offset
= arg
->offset
;
1775 val
->bitpos
= arg
->bitpos
;
1776 val
->bitsize
= arg
->bitsize
;
1777 val
->lazy
= arg
->lazy
;
1778 val
->embedded_offset
= value_embedded_offset (arg
);
1779 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1780 val
->modifiable
= arg
->modifiable
;
1781 if (!value_lazy (val
))
1783 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1784 TYPE_LENGTH (value_enclosing_type (arg
)));
1787 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1788 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1789 set_value_parent (val
, arg
->parent
);
1790 if (VALUE_LVAL (val
) == lval_computed
)
1792 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1794 if (funcs
->copy_closure
)
1795 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1800 /* Return a "const" and/or "volatile" qualified version of the value V.
1801 If CNST is true, then the returned value will be qualified with
1803 if VOLTL is true, then the returned value will be qualified with
1807 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1809 struct type
*val_type
= value_type (v
);
1810 struct type
*enclosing_type
= value_enclosing_type (v
);
1811 struct value
*cv_val
= value_copy (v
);
1813 deprecated_set_value_type (cv_val
,
1814 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1815 set_value_enclosing_type (cv_val
,
1816 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1821 /* Return a version of ARG that is non-lvalue. */
1824 value_non_lval (struct value
*arg
)
1826 if (VALUE_LVAL (arg
) != not_lval
)
1828 struct type
*enc_type
= value_enclosing_type (arg
);
1829 struct value
*val
= allocate_value (enc_type
);
1831 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1832 TYPE_LENGTH (enc_type
));
1833 val
->type
= arg
->type
;
1834 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1835 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1841 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1844 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1846 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1848 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1849 v
->lval
= lval_memory
;
1850 v
->location
.address
= addr
;
1854 set_value_component_location (struct value
*component
,
1855 const struct value
*whole
)
1859 gdb_assert (whole
->lval
!= lval_xcallable
);
1861 if (whole
->lval
== lval_internalvar
)
1862 VALUE_LVAL (component
) = lval_internalvar_component
;
1864 VALUE_LVAL (component
) = whole
->lval
;
1866 component
->location
= whole
->location
;
1867 if (whole
->lval
== lval_computed
)
1869 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1871 if (funcs
->copy_closure
)
1872 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1875 /* If type has a dynamic resolved location property
1876 update it's value address. */
1877 type
= value_type (whole
);
1878 if (NULL
!= TYPE_DATA_LOCATION (type
)
1879 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1880 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1883 /* Access to the value history. */
1885 /* Record a new value in the value history.
1886 Returns the absolute history index of the entry. */
1889 record_latest_value (struct value
*val
)
1893 /* We don't want this value to have anything to do with the inferior anymore.
1894 In particular, "set $1 = 50" should not affect the variable from which
1895 the value was taken, and fast watchpoints should be able to assume that
1896 a value on the value history never changes. */
1897 if (value_lazy (val
))
1898 value_fetch_lazy (val
);
1899 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1900 from. This is a bit dubious, because then *&$1 does not just return $1
1901 but the current contents of that location. c'est la vie... */
1902 val
->modifiable
= 0;
1904 /* The value may have already been released, in which case we're adding a
1905 new reference for its entry in the history. That is why we call
1906 release_value_or_incref here instead of release_value. */
1907 release_value_or_incref (val
);
1909 /* Here we treat value_history_count as origin-zero
1910 and applying to the value being stored now. */
1912 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1915 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1917 newobj
->next
= value_history_chain
;
1918 value_history_chain
= newobj
;
1921 value_history_chain
->values
[i
] = val
;
1923 /* Now we regard value_history_count as origin-one
1924 and applying to the value just stored. */
1926 return ++value_history_count
;
1929 /* Return a copy of the value in the history with sequence number NUM. */
1932 access_value_history (int num
)
1934 struct value_history_chunk
*chunk
;
1939 absnum
+= value_history_count
;
1944 error (_("The history is empty."));
1946 error (_("There is only one value in the history."));
1948 error (_("History does not go back to $$%d."), -num
);
1950 if (absnum
> value_history_count
)
1951 error (_("History has not yet reached $%d."), absnum
);
1955 /* Now absnum is always absolute and origin zero. */
1957 chunk
= value_history_chain
;
1958 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1959 - absnum
/ VALUE_HISTORY_CHUNK
;
1961 chunk
= chunk
->next
;
1963 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1967 show_values (char *num_exp
, int from_tty
)
1975 /* "show values +" should print from the stored position.
1976 "show values <exp>" should print around value number <exp>. */
1977 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1978 num
= parse_and_eval_long (num_exp
) - 5;
1982 /* "show values" means print the last 10 values. */
1983 num
= value_history_count
- 9;
1989 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1991 struct value_print_options opts
;
1993 val
= access_value_history (i
);
1994 printf_filtered (("$%d = "), i
);
1995 get_user_print_options (&opts
);
1996 value_print (val
, gdb_stdout
, &opts
);
1997 printf_filtered (("\n"));
2000 /* The next "show values +" should start after what we just printed. */
2003 /* Hitting just return after this command should do the same thing as
2004 "show values +". If num_exp is null, this is unnecessary, since
2005 "show values +" is not useful after "show values". */
2006 if (from_tty
&& num_exp
)
2013 enum internalvar_kind
2015 /* The internal variable is empty. */
2018 /* The value of the internal variable is provided directly as
2019 a GDB value object. */
2022 /* A fresh value is computed via a call-back routine on every
2023 access to the internal variable. */
2024 INTERNALVAR_MAKE_VALUE
,
2026 /* The internal variable holds a GDB internal convenience function. */
2027 INTERNALVAR_FUNCTION
,
2029 /* The variable holds an integer value. */
2030 INTERNALVAR_INTEGER
,
2032 /* The variable holds a GDB-provided string. */
2036 union internalvar_data
2038 /* A value object used with INTERNALVAR_VALUE. */
2039 struct value
*value
;
2041 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2044 /* The functions to call. */
2045 const struct internalvar_funcs
*functions
;
2047 /* The function's user-data. */
2051 /* The internal function used with INTERNALVAR_FUNCTION. */
2054 struct internal_function
*function
;
2055 /* True if this is the canonical name for the function. */
2059 /* An integer value used with INTERNALVAR_INTEGER. */
2062 /* If type is non-NULL, it will be used as the type to generate
2063 a value for this internal variable. If type is NULL, a default
2064 integer type for the architecture is used. */
2069 /* A string value used with INTERNALVAR_STRING. */
2073 /* Internal variables. These are variables within the debugger
2074 that hold values assigned by debugger commands.
2075 The user refers to them with a '$' prefix
2076 that does not appear in the variable names stored internally. */
2080 struct internalvar
*next
;
2083 /* We support various different kinds of content of an internal variable.
2084 enum internalvar_kind specifies the kind, and union internalvar_data
2085 provides the data associated with this particular kind. */
2087 enum internalvar_kind kind
;
2089 union internalvar_data u
;
2092 static struct internalvar
*internalvars
;
2094 /* If the variable does not already exist create it and give it the
2095 value given. If no value is given then the default is zero. */
2097 init_if_undefined_command (char* args
, int from_tty
)
2099 struct internalvar
* intvar
;
2101 /* Parse the expression - this is taken from set_command(). */
2102 expression_up expr
= parse_expression (args
);
2104 /* Validate the expression.
2105 Was the expression an assignment?
2106 Or even an expression at all? */
2107 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2108 error (_("Init-if-undefined requires an assignment expression."));
2110 /* Extract the variable from the parsed expression.
2111 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2112 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2113 error (_("The first parameter to init-if-undefined "
2114 "should be a GDB variable."));
2115 intvar
= expr
->elts
[2].internalvar
;
2117 /* Only evaluate the expression if the lvalue is void.
2118 This may still fail if the expresssion is invalid. */
2119 if (intvar
->kind
== INTERNALVAR_VOID
)
2120 evaluate_expression (expr
.get ());
2124 /* Look up an internal variable with name NAME. NAME should not
2125 normally include a dollar sign.
2127 If the specified internal variable does not exist,
2128 the return value is NULL. */
2130 struct internalvar
*
2131 lookup_only_internalvar (const char *name
)
2133 struct internalvar
*var
;
2135 for (var
= internalvars
; var
; var
= var
->next
)
2136 if (strcmp (var
->name
, name
) == 0)
2142 /* Complete NAME by comparing it to the names of internal
2146 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2148 struct internalvar
*var
;
2151 len
= strlen (name
);
2153 for (var
= internalvars
; var
; var
= var
->next
)
2154 if (strncmp (var
->name
, name
, len
) == 0)
2156 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2158 tracker
.add_completion (std::move (copy
));
2162 /* Create an internal variable with name NAME and with a void value.
2163 NAME should not normally include a dollar sign. */
2165 struct internalvar
*
2166 create_internalvar (const char *name
)
2168 struct internalvar
*var
= XNEW (struct internalvar
);
2170 var
->name
= concat (name
, (char *)NULL
);
2171 var
->kind
= INTERNALVAR_VOID
;
2172 var
->next
= internalvars
;
2177 /* Create an internal variable with name NAME and register FUN as the
2178 function that value_of_internalvar uses to create a value whenever
2179 this variable is referenced. NAME should not normally include a
2180 dollar sign. DATA is passed uninterpreted to FUN when it is
2181 called. CLEANUP, if not NULL, is called when the internal variable
2182 is destroyed. It is passed DATA as its only argument. */
2184 struct internalvar
*
2185 create_internalvar_type_lazy (const char *name
,
2186 const struct internalvar_funcs
*funcs
,
2189 struct internalvar
*var
= create_internalvar (name
);
2191 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2192 var
->u
.make_value
.functions
= funcs
;
2193 var
->u
.make_value
.data
= data
;
2197 /* See documentation in value.h. */
2200 compile_internalvar_to_ax (struct internalvar
*var
,
2201 struct agent_expr
*expr
,
2202 struct axs_value
*value
)
2204 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2205 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2208 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2209 var
->u
.make_value
.data
);
2213 /* Look up an internal variable with name NAME. NAME should not
2214 normally include a dollar sign.
2216 If the specified internal variable does not exist,
2217 one is created, with a void value. */
2219 struct internalvar
*
2220 lookup_internalvar (const char *name
)
2222 struct internalvar
*var
;
2224 var
= lookup_only_internalvar (name
);
2228 return create_internalvar (name
);
2231 /* Return current value of internal variable VAR. For variables that
2232 are not inherently typed, use a value type appropriate for GDBARCH. */
2235 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2238 struct trace_state_variable
*tsv
;
2240 /* If there is a trace state variable of the same name, assume that
2241 is what we really want to see. */
2242 tsv
= find_trace_state_variable (var
->name
);
2245 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2247 if (tsv
->value_known
)
2248 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2251 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2257 case INTERNALVAR_VOID
:
2258 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2261 case INTERNALVAR_FUNCTION
:
2262 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2265 case INTERNALVAR_INTEGER
:
2266 if (!var
->u
.integer
.type
)
2267 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2268 var
->u
.integer
.val
);
2270 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2273 case INTERNALVAR_STRING
:
2274 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2275 builtin_type (gdbarch
)->builtin_char
);
2278 case INTERNALVAR_VALUE
:
2279 val
= value_copy (var
->u
.value
);
2280 if (value_lazy (val
))
2281 value_fetch_lazy (val
);
2284 case INTERNALVAR_MAKE_VALUE
:
2285 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2286 var
->u
.make_value
.data
);
2290 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2293 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2294 on this value go back to affect the original internal variable.
2296 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2297 no underlying modifyable state in the internal variable.
2299 Likewise, if the variable's value is a computed lvalue, we want
2300 references to it to produce another computed lvalue, where
2301 references and assignments actually operate through the
2302 computed value's functions.
2304 This means that internal variables with computed values
2305 behave a little differently from other internal variables:
2306 assignments to them don't just replace the previous value
2307 altogether. At the moment, this seems like the behavior we
2310 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2311 && val
->lval
!= lval_computed
)
2313 VALUE_LVAL (val
) = lval_internalvar
;
2314 VALUE_INTERNALVAR (val
) = var
;
2321 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2323 if (var
->kind
== INTERNALVAR_INTEGER
)
2325 *result
= var
->u
.integer
.val
;
2329 if (var
->kind
== INTERNALVAR_VALUE
)
2331 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2333 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2335 *result
= value_as_long (var
->u
.value
);
2344 get_internalvar_function (struct internalvar
*var
,
2345 struct internal_function
**result
)
2349 case INTERNALVAR_FUNCTION
:
2350 *result
= var
->u
.fn
.function
;
2359 set_internalvar_component (struct internalvar
*var
,
2360 LONGEST offset
, LONGEST bitpos
,
2361 LONGEST bitsize
, struct value
*newval
)
2364 struct gdbarch
*arch
;
2369 case INTERNALVAR_VALUE
:
2370 addr
= value_contents_writeable (var
->u
.value
);
2371 arch
= get_value_arch (var
->u
.value
);
2372 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2375 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2376 value_as_long (newval
), bitpos
, bitsize
);
2378 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2379 TYPE_LENGTH (value_type (newval
)));
2383 /* We can never get a component of any other kind. */
2384 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2389 set_internalvar (struct internalvar
*var
, struct value
*val
)
2391 enum internalvar_kind new_kind
;
2392 union internalvar_data new_data
= { 0 };
2394 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2395 error (_("Cannot overwrite convenience function %s"), var
->name
);
2397 /* Prepare new contents. */
2398 switch (TYPE_CODE (check_typedef (value_type (val
))))
2400 case TYPE_CODE_VOID
:
2401 new_kind
= INTERNALVAR_VOID
;
2404 case TYPE_CODE_INTERNAL_FUNCTION
:
2405 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2406 new_kind
= INTERNALVAR_FUNCTION
;
2407 get_internalvar_function (VALUE_INTERNALVAR (val
),
2408 &new_data
.fn
.function
);
2409 /* Copies created here are never canonical. */
2413 new_kind
= INTERNALVAR_VALUE
;
2414 new_data
.value
= value_copy (val
);
2415 new_data
.value
->modifiable
= 1;
2417 /* Force the value to be fetched from the target now, to avoid problems
2418 later when this internalvar is referenced and the target is gone or
2420 if (value_lazy (new_data
.value
))
2421 value_fetch_lazy (new_data
.value
);
2423 /* Release the value from the value chain to prevent it from being
2424 deleted by free_all_values. From here on this function should not
2425 call error () until new_data is installed into the var->u to avoid
2427 release_value (new_data
.value
);
2429 /* Internal variables which are created from values with a dynamic
2430 location don't need the location property of the origin anymore.
2431 The resolved dynamic location is used prior then any other address
2432 when accessing the value.
2433 If we keep it, we would still refer to the origin value.
2434 Remove the location property in case it exist. */
2435 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2440 /* Clean up old contents. */
2441 clear_internalvar (var
);
2444 var
->kind
= new_kind
;
2446 /* End code which must not call error(). */
2450 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2452 /* Clean up old contents. */
2453 clear_internalvar (var
);
2455 var
->kind
= INTERNALVAR_INTEGER
;
2456 var
->u
.integer
.type
= NULL
;
2457 var
->u
.integer
.val
= l
;
2461 set_internalvar_string (struct internalvar
*var
, const char *string
)
2463 /* Clean up old contents. */
2464 clear_internalvar (var
);
2466 var
->kind
= INTERNALVAR_STRING
;
2467 var
->u
.string
= xstrdup (string
);
2471 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2473 /* Clean up old contents. */
2474 clear_internalvar (var
);
2476 var
->kind
= INTERNALVAR_FUNCTION
;
2477 var
->u
.fn
.function
= f
;
2478 var
->u
.fn
.canonical
= 1;
2479 /* Variables installed here are always the canonical version. */
2483 clear_internalvar (struct internalvar
*var
)
2485 /* Clean up old contents. */
2488 case INTERNALVAR_VALUE
:
2489 value_free (var
->u
.value
);
2492 case INTERNALVAR_STRING
:
2493 xfree (var
->u
.string
);
2496 case INTERNALVAR_MAKE_VALUE
:
2497 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2498 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2505 /* Reset to void kind. */
2506 var
->kind
= INTERNALVAR_VOID
;
2510 internalvar_name (const struct internalvar
*var
)
2515 static struct internal_function
*
2516 create_internal_function (const char *name
,
2517 internal_function_fn handler
, void *cookie
)
2519 struct internal_function
*ifn
= XNEW (struct internal_function
);
2521 ifn
->name
= xstrdup (name
);
2522 ifn
->handler
= handler
;
2523 ifn
->cookie
= cookie
;
2528 value_internal_function_name (struct value
*val
)
2530 struct internal_function
*ifn
;
2533 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2534 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2535 gdb_assert (result
);
2541 call_internal_function (struct gdbarch
*gdbarch
,
2542 const struct language_defn
*language
,
2543 struct value
*func
, int argc
, struct value
**argv
)
2545 struct internal_function
*ifn
;
2548 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2549 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2550 gdb_assert (result
);
2552 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2555 /* The 'function' command. This does nothing -- it is just a
2556 placeholder to let "help function NAME" work. This is also used as
2557 the implementation of the sub-command that is created when
2558 registering an internal function. */
2560 function_command (char *command
, int from_tty
)
2565 /* Clean up if an internal function's command is destroyed. */
2567 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2569 xfree ((char *) self
->name
);
2570 xfree ((char *) self
->doc
);
2573 /* Add a new internal function. NAME is the name of the function; DOC
2574 is a documentation string describing the function. HANDLER is
2575 called when the function is invoked. COOKIE is an arbitrary
2576 pointer which is passed to HANDLER and is intended for "user
2579 add_internal_function (const char *name
, const char *doc
,
2580 internal_function_fn handler
, void *cookie
)
2582 struct cmd_list_element
*cmd
;
2583 struct internal_function
*ifn
;
2584 struct internalvar
*var
= lookup_internalvar (name
);
2586 ifn
= create_internal_function (name
, handler
, cookie
);
2587 set_internalvar_function (var
, ifn
);
2589 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2591 cmd
->destroyer
= function_destroyer
;
2594 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2595 prevent cycles / duplicates. */
2598 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2599 htab_t copied_types
)
2601 if (TYPE_OBJFILE (value
->type
) == objfile
)
2602 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2604 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2605 value
->enclosing_type
= copy_type_recursive (objfile
,
2606 value
->enclosing_type
,
2610 /* Likewise for internal variable VAR. */
2613 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2614 htab_t copied_types
)
2618 case INTERNALVAR_INTEGER
:
2619 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2621 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2624 case INTERNALVAR_VALUE
:
2625 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2630 /* Update the internal variables and value history when OBJFILE is
2631 discarded; we must copy the types out of the objfile. New global types
2632 will be created for every convenience variable which currently points to
2633 this objfile's types, and the convenience variables will be adjusted to
2634 use the new global types. */
2637 preserve_values (struct objfile
*objfile
)
2639 htab_t copied_types
;
2640 struct value_history_chunk
*cur
;
2641 struct internalvar
*var
;
2644 /* Create the hash table. We allocate on the objfile's obstack, since
2645 it is soon to be deleted. */
2646 copied_types
= create_copied_types_hash (objfile
);
2648 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2649 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2651 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2653 for (var
= internalvars
; var
; var
= var
->next
)
2654 preserve_one_internalvar (var
, objfile
, copied_types
);
2656 preserve_ext_lang_values (objfile
, copied_types
);
2658 htab_delete (copied_types
);
2662 show_convenience (const char *ignore
, int from_tty
)
2664 struct gdbarch
*gdbarch
= get_current_arch ();
2665 struct internalvar
*var
;
2667 struct value_print_options opts
;
2669 get_user_print_options (&opts
);
2670 for (var
= internalvars
; var
; var
= var
->next
)
2677 printf_filtered (("$%s = "), var
->name
);
2683 val
= value_of_internalvar (gdbarch
, var
);
2684 value_print (val
, gdb_stdout
, &opts
);
2686 CATCH (ex
, RETURN_MASK_ERROR
)
2688 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2692 printf_filtered (("\n"));
2696 /* This text does not mention convenience functions on purpose.
2697 The user can't create them except via Python, and if Python support
2698 is installed this message will never be printed ($_streq will
2700 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2701 "Convenience variables have "
2702 "names starting with \"$\";\n"
2703 "use \"set\" as in \"set "
2704 "$foo = 5\" to define them.\n"));
2708 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2711 value_of_xmethod (struct xmethod_worker
*worker
)
2713 if (worker
->value
== NULL
)
2717 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2718 v
->lval
= lval_xcallable
;
2719 v
->location
.xm_worker
= worker
;
2724 return worker
->value
;
2727 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2730 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2732 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2733 && method
->lval
== lval_xcallable
&& argc
> 0);
2735 return get_xmethod_result_type (method
->location
.xm_worker
,
2736 argv
[0], argv
+ 1, argc
- 1);
2739 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2742 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2744 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2745 && method
->lval
== lval_xcallable
&& argc
> 0);
2747 return invoke_xmethod (method
->location
.xm_worker
,
2748 argv
[0], argv
+ 1, argc
- 1);
2751 /* Extract a value as a C number (either long or double).
2752 Knows how to convert fixed values to double, or
2753 floating values to long.
2754 Does not deallocate the value. */
2757 value_as_long (struct value
*val
)
2759 /* This coerces arrays and functions, which is necessary (e.g.
2760 in disassemble_command). It also dereferences references, which
2761 I suspect is the most logical thing to do. */
2762 val
= coerce_array (val
);
2763 return unpack_long (value_type (val
), value_contents (val
));
2767 value_as_double (struct value
*val
)
2772 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2774 error (_("Invalid floating value found in program."));
2778 /* Extract a value as a C pointer. Does not deallocate the value.
2779 Note that val's type may not actually be a pointer; value_as_long
2780 handles all the cases. */
2782 value_as_address (struct value
*val
)
2784 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2786 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2787 whether we want this to be true eventually. */
2789 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2790 non-address (e.g. argument to "signal", "info break", etc.), or
2791 for pointers to char, in which the low bits *are* significant. */
2792 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2795 /* There are several targets (IA-64, PowerPC, and others) which
2796 don't represent pointers to functions as simply the address of
2797 the function's entry point. For example, on the IA-64, a
2798 function pointer points to a two-word descriptor, generated by
2799 the linker, which contains the function's entry point, and the
2800 value the IA-64 "global pointer" register should have --- to
2801 support position-independent code. The linker generates
2802 descriptors only for those functions whose addresses are taken.
2804 On such targets, it's difficult for GDB to convert an arbitrary
2805 function address into a function pointer; it has to either find
2806 an existing descriptor for that function, or call malloc and
2807 build its own. On some targets, it is impossible for GDB to
2808 build a descriptor at all: the descriptor must contain a jump
2809 instruction; data memory cannot be executed; and code memory
2812 Upon entry to this function, if VAL is a value of type `function'
2813 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2814 value_address (val) is the address of the function. This is what
2815 you'll get if you evaluate an expression like `main'. The call
2816 to COERCE_ARRAY below actually does all the usual unary
2817 conversions, which includes converting values of type `function'
2818 to `pointer to function'. This is the challenging conversion
2819 discussed above. Then, `unpack_long' will convert that pointer
2820 back into an address.
2822 So, suppose the user types `disassemble foo' on an architecture
2823 with a strange function pointer representation, on which GDB
2824 cannot build its own descriptors, and suppose further that `foo'
2825 has no linker-built descriptor. The address->pointer conversion
2826 will signal an error and prevent the command from running, even
2827 though the next step would have been to convert the pointer
2828 directly back into the same address.
2830 The following shortcut avoids this whole mess. If VAL is a
2831 function, just return its address directly. */
2832 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2833 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2834 return value_address (val
);
2836 val
= coerce_array (val
);
2838 /* Some architectures (e.g. Harvard), map instruction and data
2839 addresses onto a single large unified address space. For
2840 instance: An architecture may consider a large integer in the
2841 range 0x10000000 .. 0x1000ffff to already represent a data
2842 addresses (hence not need a pointer to address conversion) while
2843 a small integer would still need to be converted integer to
2844 pointer to address. Just assume such architectures handle all
2845 integer conversions in a single function. */
2849 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2850 must admonish GDB hackers to make sure its behavior matches the
2851 compiler's, whenever possible.
2853 In general, I think GDB should evaluate expressions the same way
2854 the compiler does. When the user copies an expression out of
2855 their source code and hands it to a `print' command, they should
2856 get the same value the compiler would have computed. Any
2857 deviation from this rule can cause major confusion and annoyance,
2858 and needs to be justified carefully. In other words, GDB doesn't
2859 really have the freedom to do these conversions in clever and
2862 AndrewC pointed out that users aren't complaining about how GDB
2863 casts integers to pointers; they are complaining that they can't
2864 take an address from a disassembly listing and give it to `x/i'.
2865 This is certainly important.
2867 Adding an architecture method like integer_to_address() certainly
2868 makes it possible for GDB to "get it right" in all circumstances
2869 --- the target has complete control over how things get done, so
2870 people can Do The Right Thing for their target without breaking
2871 anyone else. The standard doesn't specify how integers get
2872 converted to pointers; usually, the ABI doesn't either, but
2873 ABI-specific code is a more reasonable place to handle it. */
2875 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2876 && !TYPE_IS_REFERENCE (value_type (val
))
2877 && gdbarch_integer_to_address_p (gdbarch
))
2878 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2879 value_contents (val
));
2881 return unpack_long (value_type (val
), value_contents (val
));
2885 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2886 as a long, or as a double, assuming the raw data is described
2887 by type TYPE. Knows how to convert different sizes of values
2888 and can convert between fixed and floating point. We don't assume
2889 any alignment for the raw data. Return value is in host byte order.
2891 If you want functions and arrays to be coerced to pointers, and
2892 references to be dereferenced, call value_as_long() instead.
2894 C++: It is assumed that the front-end has taken care of
2895 all matters concerning pointers to members. A pointer
2896 to member which reaches here is considered to be equivalent
2897 to an INT (or some size). After all, it is only an offset. */
2900 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2902 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2903 enum type_code code
= TYPE_CODE (type
);
2904 int len
= TYPE_LENGTH (type
);
2905 int nosign
= TYPE_UNSIGNED (type
);
2909 case TYPE_CODE_TYPEDEF
:
2910 return unpack_long (check_typedef (type
), valaddr
);
2911 case TYPE_CODE_ENUM
:
2912 case TYPE_CODE_FLAGS
:
2913 case TYPE_CODE_BOOL
:
2915 case TYPE_CODE_CHAR
:
2916 case TYPE_CODE_RANGE
:
2917 case TYPE_CODE_MEMBERPTR
:
2919 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2921 return extract_signed_integer (valaddr
, len
, byte_order
);
2924 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2926 case TYPE_CODE_DECFLOAT
:
2927 /* libdecnumber has a function to convert from decimal to integer, but
2928 it doesn't work when the decimal number has a fractional part. */
2929 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2933 case TYPE_CODE_RVALUE_REF
:
2934 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2935 whether we want this to be true eventually. */
2936 return extract_typed_address (valaddr
, type
);
2939 error (_("Value can't be converted to integer."));
2941 return 0; /* Placate lint. */
2944 /* Return a double value from the specified type and address.
2945 INVP points to an int which is set to 0 for valid value,
2946 1 for invalid value (bad float format). In either case,
2947 the returned double is OK to use. Argument is in target
2948 format, result is in host format. */
2951 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2953 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2954 enum type_code code
;
2958 *invp
= 0; /* Assume valid. */
2959 type
= check_typedef (type
);
2960 code
= TYPE_CODE (type
);
2961 len
= TYPE_LENGTH (type
);
2962 nosign
= TYPE_UNSIGNED (type
);
2963 if (code
== TYPE_CODE_FLT
)
2965 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2966 floating-point value was valid (using the macro
2967 INVALID_FLOAT). That test/macro have been removed.
2969 It turns out that only the VAX defined this macro and then
2970 only in a non-portable way. Fixing the portability problem
2971 wouldn't help since the VAX floating-point code is also badly
2972 bit-rotten. The target needs to add definitions for the
2973 methods gdbarch_float_format and gdbarch_double_format - these
2974 exactly describe the target floating-point format. The
2975 problem here is that the corresponding floatformat_vax_f and
2976 floatformat_vax_d values these methods should be set to are
2977 also not defined either. Oops!
2979 Hopefully someone will add both the missing floatformat
2980 definitions and the new cases for floatformat_is_valid (). */
2982 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2988 return extract_typed_floating (valaddr
, type
);
2990 else if (code
== TYPE_CODE_DECFLOAT
)
2991 return decimal_to_doublest (valaddr
, len
, byte_order
);
2994 /* Unsigned -- be sure we compensate for signed LONGEST. */
2995 return (ULONGEST
) unpack_long (type
, valaddr
);
2999 /* Signed -- we are OK with unpack_long. */
3000 return unpack_long (type
, valaddr
);
3004 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3005 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3006 We don't assume any alignment for the raw data. Return value is in
3009 If you want functions and arrays to be coerced to pointers, and
3010 references to be dereferenced, call value_as_address() instead.
3012 C++: It is assumed that the front-end has taken care of
3013 all matters concerning pointers to members. A pointer
3014 to member which reaches here is considered to be equivalent
3015 to an INT (or some size). After all, it is only an offset. */
3018 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3020 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3021 whether we want this to be true eventually. */
3022 return unpack_long (type
, valaddr
);
3026 /* Get the value of the FIELDNO'th field (which must be static) of
3030 value_static_field (struct type
*type
, int fieldno
)
3032 struct value
*retval
;
3034 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3036 case FIELD_LOC_KIND_PHYSADDR
:
3037 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3038 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3040 case FIELD_LOC_KIND_PHYSNAME
:
3042 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3043 /* TYPE_FIELD_NAME (type, fieldno); */
3044 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3046 if (sym
.symbol
== NULL
)
3048 /* With some compilers, e.g. HP aCC, static data members are
3049 reported as non-debuggable symbols. */
3050 struct bound_minimal_symbol msym
3051 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3054 return allocate_optimized_out_value (type
);
3057 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3058 BMSYMBOL_VALUE_ADDRESS (msym
));
3062 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3066 gdb_assert_not_reached ("unexpected field location kind");
3072 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3073 You have to be careful here, since the size of the data area for the value
3074 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3075 than the old enclosing type, you have to allocate more space for the
3079 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3081 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3083 check_type_length_before_alloc (new_encl_type
);
3085 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3088 val
->enclosing_type
= new_encl_type
;
3091 /* Given a value ARG1 (offset by OFFSET bytes)
3092 of a struct or union type ARG_TYPE,
3093 extract and return the value of one of its (non-static) fields.
3094 FIELDNO says which field. */
3097 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3098 int fieldno
, struct type
*arg_type
)
3102 struct gdbarch
*arch
= get_value_arch (arg1
);
3103 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3105 arg_type
= check_typedef (arg_type
);
3106 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3108 /* Call check_typedef on our type to make sure that, if TYPE
3109 is a TYPE_CODE_TYPEDEF, its length is set to the length
3110 of the target type instead of zero. However, we do not
3111 replace the typedef type by the target type, because we want
3112 to keep the typedef in order to be able to print the type
3113 description correctly. */
3114 check_typedef (type
);
3116 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3118 /* Handle packed fields.
3120 Create a new value for the bitfield, with bitpos and bitsize
3121 set. If possible, arrange offset and bitpos so that we can
3122 do a single aligned read of the size of the containing type.
3123 Otherwise, adjust offset to the byte containing the first
3124 bit. Assume that the address, offset, and embedded offset
3125 are sufficiently aligned. */
3127 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3128 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3130 v
= allocate_value_lazy (type
);
3131 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3132 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3133 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3134 v
->bitpos
= bitpos
% container_bitsize
;
3136 v
->bitpos
= bitpos
% 8;
3137 v
->offset
= (value_embedded_offset (arg1
)
3139 + (bitpos
- v
->bitpos
) / 8);
3140 set_value_parent (v
, arg1
);
3141 if (!value_lazy (arg1
))
3142 value_fetch_lazy (v
);
3144 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3146 /* This field is actually a base subobject, so preserve the
3147 entire object's contents for later references to virtual
3151 /* Lazy register values with offsets are not supported. */
3152 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3153 value_fetch_lazy (arg1
);
3155 /* We special case virtual inheritance here because this
3156 requires access to the contents, which we would rather avoid
3157 for references to ordinary fields of unavailable values. */
3158 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3159 boffset
= baseclass_offset (arg_type
, fieldno
,
3160 value_contents (arg1
),
3161 value_embedded_offset (arg1
),
3162 value_address (arg1
),
3165 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3167 if (value_lazy (arg1
))
3168 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3171 v
= allocate_value (value_enclosing_type (arg1
));
3172 value_contents_copy_raw (v
, 0, arg1
, 0,
3173 TYPE_LENGTH (value_enclosing_type (arg1
)));
3176 v
->offset
= value_offset (arg1
);
3177 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3179 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3181 /* Field is a dynamic data member. */
3183 gdb_assert (0 == offset
);
3184 /* We expect an already resolved data location. */
3185 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3186 /* For dynamic data types defer memory allocation
3187 until we actual access the value. */
3188 v
= allocate_value_lazy (type
);
3192 /* Plain old data member */
3193 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3194 / (HOST_CHAR_BIT
* unit_size
));
3196 /* Lazy register values with offsets are not supported. */
3197 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3198 value_fetch_lazy (arg1
);
3200 if (value_lazy (arg1
))
3201 v
= allocate_value_lazy (type
);
3204 v
= allocate_value (type
);
3205 value_contents_copy_raw (v
, value_embedded_offset (v
),
3206 arg1
, value_embedded_offset (arg1
) + offset
,
3207 type_length_units (type
));
3209 v
->offset
= (value_offset (arg1
) + offset
3210 + value_embedded_offset (arg1
));
3212 set_value_component_location (v
, arg1
);
3216 /* Given a value ARG1 of a struct or union type,
3217 extract and return the value of one of its (non-static) fields.
3218 FIELDNO says which field. */
3221 value_field (struct value
*arg1
, int fieldno
)
3223 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3226 /* Return a non-virtual function as a value.
3227 F is the list of member functions which contains the desired method.
3228 J is an index into F which provides the desired method.
3230 We only use the symbol for its address, so be happy with either a
3231 full symbol or a minimal symbol. */
3234 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3235 int j
, struct type
*type
,
3239 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3240 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3242 struct bound_minimal_symbol msym
;
3244 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3247 memset (&msym
, 0, sizeof (msym
));
3251 gdb_assert (sym
== NULL
);
3252 msym
= lookup_bound_minimal_symbol (physname
);
3253 if (msym
.minsym
== NULL
)
3257 v
= allocate_value (ftype
);
3258 VALUE_LVAL (v
) = lval_memory
;
3261 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3265 /* The minimal symbol might point to a function descriptor;
3266 resolve it to the actual code address instead. */
3267 struct objfile
*objfile
= msym
.objfile
;
3268 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3270 set_value_address (v
,
3271 gdbarch_convert_from_func_ptr_addr
3272 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3277 if (type
!= value_type (*arg1p
))
3278 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3279 value_addr (*arg1p
)));
3281 /* Move the `this' pointer according to the offset.
3282 VALUE_OFFSET (*arg1p) += offset; */
3290 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3291 VALADDR, and store the result in *RESULT.
3292 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3294 Extracting bits depends on endianness of the machine. Compute the
3295 number of least significant bits to discard. For big endian machines,
3296 we compute the total number of bits in the anonymous object, subtract
3297 off the bit count from the MSB of the object to the MSB of the
3298 bitfield, then the size of the bitfield, which leaves the LSB discard
3299 count. For little endian machines, the discard count is simply the
3300 number of bits from the LSB of the anonymous object to the LSB of the
3303 If the field is signed, we also do sign extension. */
3306 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3307 LONGEST bitpos
, LONGEST bitsize
)
3309 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3314 LONGEST read_offset
;
3316 /* Read the minimum number of bytes required; there may not be
3317 enough bytes to read an entire ULONGEST. */
3318 field_type
= check_typedef (field_type
);
3320 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3322 bytes_read
= TYPE_LENGTH (field_type
);
3324 read_offset
= bitpos
/ 8;
3326 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3327 bytes_read
, byte_order
);
3329 /* Extract bits. See comment above. */
3331 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3332 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3334 lsbcount
= (bitpos
% 8);
3337 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3338 If the field is signed, and is negative, then sign extend. */
3340 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3342 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3344 if (!TYPE_UNSIGNED (field_type
))
3346 if (val
& (valmask
^ (valmask
>> 1)))
3356 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3357 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3358 ORIGINAL_VALUE, which must not be NULL. See
3359 unpack_value_bits_as_long for more details. */
3362 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3363 LONGEST embedded_offset
, int fieldno
,
3364 const struct value
*val
, LONGEST
*result
)
3366 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3367 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3368 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3371 gdb_assert (val
!= NULL
);
3373 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3374 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3375 || !value_bits_available (val
, bit_offset
, bitsize
))
3378 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3383 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3384 object at VALADDR. See unpack_bits_as_long for more details. */
3387 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3389 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3390 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3391 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3393 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3396 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3397 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3398 the contents in DEST_VAL, zero or sign extending if the type of
3399 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3400 VAL. If the VAL's contents required to extract the bitfield from
3401 are unavailable/optimized out, DEST_VAL is correspondingly
3402 marked unavailable/optimized out. */
3405 unpack_value_bitfield (struct value
*dest_val
,
3406 LONGEST bitpos
, LONGEST bitsize
,
3407 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3408 const struct value
*val
)
3410 enum bfd_endian byte_order
;
3413 struct type
*field_type
= value_type (dest_val
);
3415 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3417 /* First, unpack and sign extend the bitfield as if it was wholly
3418 valid. Optimized out/unavailable bits are read as zero, but
3419 that's OK, as they'll end up marked below. If the VAL is
3420 wholly-invalid we may have skipped allocating its contents,
3421 though. See allocate_optimized_out_value. */
3422 if (valaddr
!= NULL
)
3426 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3428 store_signed_integer (value_contents_raw (dest_val
),
3429 TYPE_LENGTH (field_type
), byte_order
, num
);
3432 /* Now copy the optimized out / unavailability ranges to the right
3434 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3435 if (byte_order
== BFD_ENDIAN_BIG
)
3436 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3439 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3440 val
, src_bit_offset
, bitsize
);
3443 /* Return a new value with type TYPE, which is FIELDNO field of the
3444 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3445 of VAL. If the VAL's contents required to extract the bitfield
3446 from are unavailable/optimized out, the new value is
3447 correspondingly marked unavailable/optimized out. */
3450 value_field_bitfield (struct type
*type
, int fieldno
,
3451 const gdb_byte
*valaddr
,
3452 LONGEST embedded_offset
, const struct value
*val
)
3454 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3455 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3456 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3458 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3459 valaddr
, embedded_offset
, val
);
3464 /* Modify the value of a bitfield. ADDR points to a block of memory in
3465 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3466 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3467 indicate which bits (in target bit order) comprise the bitfield.
3468 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3469 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3472 modify_field (struct type
*type
, gdb_byte
*addr
,
3473 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3475 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3477 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3480 /* Normalize BITPOS. */
3484 /* If a negative fieldval fits in the field in question, chop
3485 off the sign extension bits. */
3486 if ((~fieldval
& ~(mask
>> 1)) == 0)
3489 /* Warn if value is too big to fit in the field in question. */
3490 if (0 != (fieldval
& ~mask
))
3492 /* FIXME: would like to include fieldval in the message, but
3493 we don't have a sprintf_longest. */
3494 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3496 /* Truncate it, otherwise adjoining fields may be corrupted. */
3500 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3501 false valgrind reports. */
3503 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3504 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3506 /* Shifting for bit field depends on endianness of the target machine. */
3507 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3508 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3510 oword
&= ~(mask
<< bitpos
);
3511 oword
|= fieldval
<< bitpos
;
3513 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3516 /* Pack NUM into BUF using a target format of TYPE. */
3519 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3521 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3524 type
= check_typedef (type
);
3525 len
= TYPE_LENGTH (type
);
3527 switch (TYPE_CODE (type
))
3530 case TYPE_CODE_CHAR
:
3531 case TYPE_CODE_ENUM
:
3532 case TYPE_CODE_FLAGS
:
3533 case TYPE_CODE_BOOL
:
3534 case TYPE_CODE_RANGE
:
3535 case TYPE_CODE_MEMBERPTR
:
3536 store_signed_integer (buf
, len
, byte_order
, num
);
3540 case TYPE_CODE_RVALUE_REF
:
3542 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3546 error (_("Unexpected type (%d) encountered for integer constant."),
3552 /* Pack NUM into BUF using a target format of TYPE. */
3555 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3558 enum bfd_endian byte_order
;
3560 type
= check_typedef (type
);
3561 len
= TYPE_LENGTH (type
);
3562 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3564 switch (TYPE_CODE (type
))
3567 case TYPE_CODE_CHAR
:
3568 case TYPE_CODE_ENUM
:
3569 case TYPE_CODE_FLAGS
:
3570 case TYPE_CODE_BOOL
:
3571 case TYPE_CODE_RANGE
:
3572 case TYPE_CODE_MEMBERPTR
:
3573 store_unsigned_integer (buf
, len
, byte_order
, num
);
3577 case TYPE_CODE_RVALUE_REF
:
3579 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3583 error (_("Unexpected type (%d) encountered "
3584 "for unsigned integer constant."),
3590 /* Convert C numbers into newly allocated values. */
3593 value_from_longest (struct type
*type
, LONGEST num
)
3595 struct value
*val
= allocate_value (type
);
3597 pack_long (value_contents_raw (val
), type
, num
);
3602 /* Convert C unsigned numbers into newly allocated values. */
3605 value_from_ulongest (struct type
*type
, ULONGEST num
)
3607 struct value
*val
= allocate_value (type
);
3609 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3615 /* Create a value representing a pointer of type TYPE to the address
3619 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3621 struct value
*val
= allocate_value (type
);
3623 store_typed_address (value_contents_raw (val
),
3624 check_typedef (type
), addr
);
3629 /* Create a value of type TYPE whose contents come from VALADDR, if it
3630 is non-null, and whose memory address (in the inferior) is
3631 ADDRESS. The type of the created value may differ from the passed
3632 type TYPE. Make sure to retrieve values new type after this call.
3633 Note that TYPE is not passed through resolve_dynamic_type; this is
3634 a special API intended for use only by Ada. */
3637 value_from_contents_and_address_unresolved (struct type
*type
,
3638 const gdb_byte
*valaddr
,
3643 if (valaddr
== NULL
)
3644 v
= allocate_value_lazy (type
);
3646 v
= value_from_contents (type
, valaddr
);
3647 VALUE_LVAL (v
) = lval_memory
;
3648 set_value_address (v
, address
);
3652 /* Create a value of type TYPE whose contents come from VALADDR, if it
3653 is non-null, and whose memory address (in the inferior) is
3654 ADDRESS. The type of the created value may differ from the passed
3655 type TYPE. Make sure to retrieve values new type after this call. */
3658 value_from_contents_and_address (struct type
*type
,
3659 const gdb_byte
*valaddr
,
3662 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3663 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3666 if (valaddr
== NULL
)
3667 v
= allocate_value_lazy (resolved_type
);
3669 v
= value_from_contents (resolved_type
, valaddr
);
3670 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3671 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3672 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3673 VALUE_LVAL (v
) = lval_memory
;
3674 set_value_address (v
, address
);
3678 /* Create a value of type TYPE holding the contents CONTENTS.
3679 The new value is `not_lval'. */
3682 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3684 struct value
*result
;
3686 result
= allocate_value (type
);
3687 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3692 value_from_double (struct type
*type
, DOUBLEST num
)
3694 struct value
*val
= allocate_value (type
);
3695 struct type
*base_type
= check_typedef (type
);
3696 enum type_code code
= TYPE_CODE (base_type
);
3698 if (code
== TYPE_CODE_FLT
)
3700 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3703 error (_("Unexpected type encountered for floating constant."));
3709 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3711 struct value
*val
= allocate_value (type
);
3713 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3717 /* Extract a value from the history file. Input will be of the form
3718 $digits or $$digits. See block comment above 'write_dollar_variable'
3722 value_from_history_ref (const char *h
, const char **endp
)
3734 /* Find length of numeral string. */
3735 for (; isdigit (h
[len
]); len
++)
3738 /* Make sure numeral string is not part of an identifier. */
3739 if (h
[len
] == '_' || isalpha (h
[len
]))
3742 /* Now collect the index value. */
3747 /* For some bizarre reason, "$$" is equivalent to "$$1",
3748 rather than to "$$0" as it ought to be! */
3756 index
= -strtol (&h
[2], &local_end
, 10);
3764 /* "$" is equivalent to "$0". */
3772 index
= strtol (&h
[1], &local_end
, 10);
3777 return access_value_history (index
);
3780 /* Get the component value (offset by OFFSET bytes) of a struct or
3781 union WHOLE. Component's type is TYPE. */
3784 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3788 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3789 v
= allocate_value_lazy (type
);
3792 v
= allocate_value (type
);
3793 value_contents_copy (v
, value_embedded_offset (v
),
3794 whole
, value_embedded_offset (whole
) + offset
,
3795 type_length_units (type
));
3797 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3798 set_value_component_location (v
, whole
);
3804 coerce_ref_if_computed (const struct value
*arg
)
3806 const struct lval_funcs
*funcs
;
3808 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3811 if (value_lval_const (arg
) != lval_computed
)
3814 funcs
= value_computed_funcs (arg
);
3815 if (funcs
->coerce_ref
== NULL
)
3818 return funcs
->coerce_ref (arg
);
3821 /* Look at value.h for description. */
3824 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3825 const struct type
*original_type
,
3826 const struct value
*original_value
)
3828 /* Re-adjust type. */
3829 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3831 /* Add embedding info. */
3832 set_value_enclosing_type (value
, enc_type
);
3833 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3835 /* We may be pointing to an object of some derived type. */
3836 return value_full_object (value
, NULL
, 0, 0, 0);
3840 coerce_ref (struct value
*arg
)
3842 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3843 struct value
*retval
;
3844 struct type
*enc_type
;
3846 retval
= coerce_ref_if_computed (arg
);
3850 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3853 enc_type
= check_typedef (value_enclosing_type (arg
));
3854 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3856 retval
= value_at_lazy (enc_type
,
3857 unpack_pointer (value_type (arg
),
3858 value_contents (arg
)));
3859 enc_type
= value_type (retval
);
3860 return readjust_indirect_value_type (retval
, enc_type
,
3861 value_type_arg_tmp
, arg
);
3865 coerce_array (struct value
*arg
)
3869 arg
= coerce_ref (arg
);
3870 type
= check_typedef (value_type (arg
));
3872 switch (TYPE_CODE (type
))
3874 case TYPE_CODE_ARRAY
:
3875 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3876 arg
= value_coerce_array (arg
);
3878 case TYPE_CODE_FUNC
:
3879 arg
= value_coerce_function (arg
);
3886 /* Return the return value convention that will be used for the
3889 enum return_value_convention
3890 struct_return_convention (struct gdbarch
*gdbarch
,
3891 struct value
*function
, struct type
*value_type
)
3893 enum type_code code
= TYPE_CODE (value_type
);
3895 if (code
== TYPE_CODE_ERROR
)
3896 error (_("Function return type unknown."));
3898 /* Probe the architecture for the return-value convention. */
3899 return gdbarch_return_value (gdbarch
, function
, value_type
,
3903 /* Return true if the function returning the specified type is using
3904 the convention of returning structures in memory (passing in the
3905 address as a hidden first parameter). */
3908 using_struct_return (struct gdbarch
*gdbarch
,
3909 struct value
*function
, struct type
*value_type
)
3911 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3912 /* A void return value is never in memory. See also corresponding
3913 code in "print_return_value". */
3916 return (struct_return_convention (gdbarch
, function
, value_type
)
3917 != RETURN_VALUE_REGISTER_CONVENTION
);
3920 /* Set the initialized field in a value struct. */
3923 set_value_initialized (struct value
*val
, int status
)
3925 val
->initialized
= status
;
3928 /* Return the initialized field in a value struct. */
3931 value_initialized (const struct value
*val
)
3933 return val
->initialized
;
3936 /* Load the actual content of a lazy value. Fetch the data from the
3937 user's process and clear the lazy flag to indicate that the data in
3938 the buffer is valid.
3940 If the value is zero-length, we avoid calling read_memory, which
3941 would abort. We mark the value as fetched anyway -- all 0 bytes of
3945 value_fetch_lazy (struct value
*val
)
3947 gdb_assert (value_lazy (val
));
3948 allocate_value_contents (val
);
3949 /* A value is either lazy, or fully fetched. The
3950 availability/validity is only established as we try to fetch a
3952 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3953 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3954 if (value_bitsize (val
))
3956 /* To read a lazy bitfield, read the entire enclosing value. This
3957 prevents reading the same block of (possibly volatile) memory once
3958 per bitfield. It would be even better to read only the containing
3959 word, but we have no way to record that just specific bits of a
3960 value have been fetched. */
3961 struct type
*type
= check_typedef (value_type (val
));
3962 struct value
*parent
= value_parent (val
);
3964 if (value_lazy (parent
))
3965 value_fetch_lazy (parent
);
3967 unpack_value_bitfield (val
,
3968 value_bitpos (val
), value_bitsize (val
),
3969 value_contents_for_printing (parent
),
3970 value_offset (val
), parent
);
3972 else if (VALUE_LVAL (val
) == lval_memory
)
3974 CORE_ADDR addr
= value_address (val
);
3975 struct type
*type
= check_typedef (value_enclosing_type (val
));
3977 if (TYPE_LENGTH (type
))
3978 read_value_memory (val
, 0, value_stack (val
),
3979 addr
, value_contents_all_raw (val
),
3980 type_length_units (type
));
3982 else if (VALUE_LVAL (val
) == lval_register
)
3984 struct frame_info
*next_frame
;
3986 struct type
*type
= check_typedef (value_type (val
));
3987 struct value
*new_val
= val
, *mark
= value_mark ();
3989 /* Offsets are not supported here; lazy register values must
3990 refer to the entire register. */
3991 gdb_assert (value_offset (val
) == 0);
3993 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3995 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3997 next_frame
= frame_find_by_id (next_frame_id
);
3998 regnum
= VALUE_REGNUM (new_val
);
4000 gdb_assert (next_frame
!= NULL
);
4002 /* Convertible register routines are used for multi-register
4003 values and for interpretation in different types
4004 (e.g. float or int from a double register). Lazy
4005 register values should have the register's natural type,
4006 so they do not apply. */
4007 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
4010 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
4011 Since a "->next" operation was performed when setting
4012 this field, we do not need to perform a "next" operation
4013 again when unwinding the register. That's why
4014 frame_unwind_register_value() is called here instead of
4015 get_frame_register_value(). */
4016 new_val
= frame_unwind_register_value (next_frame
, regnum
);
4018 /* If we get another lazy lval_register value, it means the
4019 register is found by reading it from NEXT_FRAME's next frame.
4020 frame_unwind_register_value should never return a value with
4021 the frame id pointing to NEXT_FRAME. If it does, it means we
4022 either have two consecutive frames with the same frame id
4023 in the frame chain, or some code is trying to unwind
4024 behind get_prev_frame's back (e.g., a frame unwind
4025 sniffer trying to unwind), bypassing its validations. In
4026 any case, it should always be an internal error to end up
4027 in this situation. */
4028 if (VALUE_LVAL (new_val
) == lval_register
4029 && value_lazy (new_val
)
4030 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
4031 internal_error (__FILE__
, __LINE__
,
4032 _("infinite loop while fetching a register"));
4035 /* If it's still lazy (for instance, a saved register on the
4036 stack), fetch it. */
4037 if (value_lazy (new_val
))
4038 value_fetch_lazy (new_val
);
4040 /* Copy the contents and the unavailability/optimized-out
4041 meta-data from NEW_VAL to VAL. */
4042 set_value_lazy (val
, 0);
4043 value_contents_copy (val
, value_embedded_offset (val
),
4044 new_val
, value_embedded_offset (new_val
),
4045 type_length_units (type
));
4049 struct gdbarch
*gdbarch
;
4050 struct frame_info
*frame
;
4051 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
4052 so that the frame level will be shown correctly. */
4053 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4054 regnum
= VALUE_REGNUM (val
);
4055 gdbarch
= get_frame_arch (frame
);
4057 fprintf_unfiltered (gdb_stdlog
,
4058 "{ value_fetch_lazy "
4059 "(frame=%d,regnum=%d(%s),...) ",
4060 frame_relative_level (frame
), regnum
,
4061 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4063 fprintf_unfiltered (gdb_stdlog
, "->");
4064 if (value_optimized_out (new_val
))
4066 fprintf_unfiltered (gdb_stdlog
, " ");
4067 val_print_optimized_out (new_val
, gdb_stdlog
);
4072 const gdb_byte
*buf
= value_contents (new_val
);
4074 if (VALUE_LVAL (new_val
) == lval_register
)
4075 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4076 VALUE_REGNUM (new_val
));
4077 else if (VALUE_LVAL (new_val
) == lval_memory
)
4078 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4080 value_address (new_val
)));
4082 fprintf_unfiltered (gdb_stdlog
, " computed");
4084 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4085 fprintf_unfiltered (gdb_stdlog
, "[");
4086 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4087 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4088 fprintf_unfiltered (gdb_stdlog
, "]");
4091 fprintf_unfiltered (gdb_stdlog
, " }\n");
4094 /* Dispose of the intermediate values. This prevents
4095 watchpoints from trying to watch the saved frame pointer. */
4096 value_free_to_mark (mark
);
4098 else if (VALUE_LVAL (val
) == lval_computed
4099 && value_computed_funcs (val
)->read
!= NULL
)
4100 value_computed_funcs (val
)->read (val
);
4102 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4104 set_value_lazy (val
, 0);
4107 /* Implementation of the convenience function $_isvoid. */
4109 static struct value
*
4110 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4111 const struct language_defn
*language
,
4112 void *cookie
, int argc
, struct value
**argv
)
4117 error (_("You must provide one argument for $_isvoid."));
4119 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4121 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4125 _initialize_values (void)
4127 add_cmd ("convenience", no_class
, show_convenience
, _("\
4128 Debugger convenience (\"$foo\") variables and functions.\n\
4129 Convenience variables are created when you assign them values;\n\
4130 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4132 A few convenience variables are given values automatically:\n\
4133 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4134 \"$__\" holds the contents of the last address examined with \"x\"."
4137 Convenience functions are defined via the Python API."
4140 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4142 add_cmd ("values", no_set_class
, show_values
, _("\
4143 Elements of value history around item number IDX (or last ten)."),
4146 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4147 Initialize a convenience variable if necessary.\n\
4148 init-if-undefined VARIABLE = EXPRESSION\n\
4149 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4150 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4151 VARIABLE is already initialized."));
4153 add_prefix_cmd ("function", no_class
, function_command
, _("\
4154 Placeholder command for showing help on convenience functions."),
4155 &functionlist
, "function ", 0, &cmdlist
);
4157 add_internal_function ("_isvoid", _("\
4158 Check whether an expression is void.\n\
4159 Usage: $_isvoid (expression)\n\
4160 Return 1 if the expression is void, zero otherwise."),
4161 isvoid_internal_fn
, NULL
);
4163 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4164 class_support
, &max_value_size
, _("\
4165 Set maximum sized value gdb will load from the inferior."), _("\
4166 Show maximum sized value gdb will load from the inferior."), _("\
4167 Use this to control the maximum size, in bytes, of a value that gdb\n\
4168 will load from the inferior. Setting this value to 'unlimited'\n\
4169 disables checking.\n\
4170 Setting this does not invalidate already allocated values, it only\n\
4171 prevents future values, larger than this size, from being allocated."),
4173 show_max_value_size
,
4174 &setlist
, &showlist
);