1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
33 #include "target-float.h"
36 #include "cli/cli-decode.h"
37 #include "extension.h"
39 #include "tracepoint.h"
41 #include "user-regs.h"
43 #include "completer.h"
45 /* Definition of a user function. */
46 struct internal_function
48 /* The name of the function. It is a bit odd to have this in the
49 function itself -- the user might use a differently-named
50 convenience variable to hold the function. */
54 internal_function_fn handler
;
56 /* User data for the handler. */
60 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
64 /* Lowest offset in the range. */
67 /* Length of the range. */
71 typedef struct range range_s
;
75 /* Returns true if the ranges defined by [offset1, offset1+len1) and
76 [offset2, offset2+len2) overlap. */
79 ranges_overlap (LONGEST offset1
, LONGEST len1
,
80 LONGEST offset2
, LONGEST len2
)
84 l
= std::max (offset1
, offset2
);
85 h
= std::min (offset1
+ len1
, offset2
+ len2
);
89 /* Returns true if the first argument is strictly less than the
90 second, useful for VEC_lower_bound. We keep ranges sorted by
91 offset and coalesce overlapping and contiguous ranges, so this just
92 compares the starting offset. */
95 range_lessthan (const range_s
*r1
, const range_s
*r2
)
97 return r1
->offset
< r2
->offset
;
100 /* Returns true if RANGES contains any range that overlaps [OFFSET,
104 ranges_contain (VEC(range_s
) *ranges
, LONGEST offset
, LONGEST length
)
109 what
.offset
= offset
;
110 what
.length
= length
;
112 /* We keep ranges sorted by offset and coalesce overlapping and
113 contiguous ranges, so to check if a range list contains a given
114 range, we can do a binary search for the position the given range
115 would be inserted if we only considered the starting OFFSET of
116 ranges. We call that position I. Since we also have LENGTH to
117 care for (this is a range afterall), we need to check if the
118 _previous_ range overlaps the I range. E.g.,
122 |---| |---| |------| ... |--|
127 In the case above, the binary search would return `I=1', meaning,
128 this OFFSET should be inserted at position 1, and the current
129 position 1 should be pushed further (and before 2). But, `0'
132 Then we need to check if the I range overlaps the I range itself.
137 |---| |---| |-------| ... |--|
143 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
147 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
149 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
153 if (i
< VEC_length (range_s
, ranges
))
155 struct range
*r
= VEC_index (range_s
, ranges
, i
);
157 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
164 static struct cmd_list_element
*functionlist
;
166 /* Note that the fields in this structure are arranged to save a bit
171 /* Type of value; either not an lval, or one of the various
172 different possible kinds of lval. */
175 /* Is it modifiable? Only relevant if lval != not_lval. */
176 unsigned int modifiable
: 1;
178 /* If zero, contents of this value are in the contents field. If
179 nonzero, contents are in inferior. If the lval field is lval_memory,
180 the contents are in inferior memory at location.address plus offset.
181 The lval field may also be lval_register.
183 WARNING: This field is used by the code which handles watchpoints
184 (see breakpoint.c) to decide whether a particular value can be
185 watched by hardware watchpoints. If the lazy flag is set for
186 some member of a value chain, it is assumed that this member of
187 the chain doesn't need to be watched as part of watching the
188 value itself. This is how GDB avoids watching the entire struct
189 or array when the user wants to watch a single struct member or
190 array element. If you ever change the way lazy flag is set and
191 reset, be sure to consider this use as well! */
192 unsigned int lazy
: 1;
194 /* If value is a variable, is it initialized or not. */
195 unsigned int initialized
: 1;
197 /* If value is from the stack. If this is set, read_stack will be
198 used instead of read_memory to enable extra caching. */
199 unsigned int stack
: 1;
201 /* If the value has been released. */
202 unsigned int released
: 1;
204 /* Location of value (if lval). */
207 /* If lval == lval_memory, this is the address in the inferior */
210 /*If lval == lval_register, the value is from a register. */
213 /* Register number. */
215 /* Frame ID of "next" frame to which a register value is relative.
216 If the register value is found relative to frame F, then the
217 frame id of F->next will be stored in next_frame_id. */
218 struct frame_id next_frame_id
;
221 /* Pointer to internal variable. */
222 struct internalvar
*internalvar
;
224 /* Pointer to xmethod worker. */
225 struct xmethod_worker
*xm_worker
;
227 /* If lval == lval_computed, this is a set of function pointers
228 to use to access and describe the value, and a closure pointer
232 /* Functions to call. */
233 const struct lval_funcs
*funcs
;
235 /* Closure for those functions to use. */
240 /* Describes offset of a value within lval of a structure in target
241 addressable memory units. Note also the member embedded_offset
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value
*parent
;
265 /* Type of the value. */
268 /* If a value represents a C++ object, then the `type' field gives
269 the object's compile-time type. If the object actually belongs
270 to some class derived from `type', perhaps with other base
271 classes and additional members, then `type' is just a subobject
272 of the real thing, and the full object is probably larger than
273 `type' would suggest.
275 If `type' is a dynamic class (i.e. one with a vtable), then GDB
276 can actually determine the object's run-time type by looking at
277 the run-time type information in the vtable. When this
278 information is available, we may elect to read in the entire
279 object, for several reasons:
281 - When printing the value, the user would probably rather see the
282 full object, not just the limited portion apparent from the
285 - If `type' has virtual base classes, then even printing `type'
286 alone may require reaching outside the `type' portion of the
287 object to wherever the virtual base class has been stored.
289 When we store the entire object, `enclosing_type' is the run-time
290 type -- the complete object -- and `embedded_offset' is the
291 offset of `type' within that larger type, in target addressable memory
292 units. The value_contents() macro takes `embedded_offset' into account,
293 so most GDB code continues to see the `type' portion of the value, just
294 as the inferior would.
296 If `type' is a pointer to an object, then `enclosing_type' is a
297 pointer to the object's run-time type, and `pointed_to_offset' is
298 the offset in target addressable memory units from the full object
299 to the pointed-to object -- that is, the value `embedded_offset' would
300 have if we followed the pointer and fetched the complete object.
301 (I don't really see the point. Why not just determine the
302 run-time type when you indirect, and avoid the special case? The
303 contents don't matter until you indirect anyway.)
305 If we're not doing anything fancy, `enclosing_type' is equal to
306 `type', and `embedded_offset' is zero, so everything works
308 struct type
*enclosing_type
;
309 LONGEST embedded_offset
;
310 LONGEST pointed_to_offset
;
312 /* Values are stored in a chain, so that they can be deleted easily
313 over calls to the inferior. Values assigned to internal
314 variables, put into the value history or exposed to Python are
315 taken off this list. */
318 /* Actual contents of the value. Target byte-order. NULL or not
319 valid if lazy is nonzero. */
322 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
323 rather than available, since the common and default case is for a
324 value to be available. This is filled in at value read time.
325 The unavailable ranges are tracked in bits. Note that a contents
326 bit that has been optimized out doesn't really exist in the
327 program, so it can't be marked unavailable either. */
328 VEC(range_s
) *unavailable
;
330 /* Likewise, but for optimized out contents (a chunk of the value of
331 a variable that does not actually exist in the program). If LVAL
332 is lval_register, this is a register ($pc, $sp, etc., never a
333 program variable) that has not been saved in the frame. Not
334 saved registers and optimized-out program variables values are
335 treated pretty much the same, except not-saved registers have a
336 different string representation and related error strings. */
337 VEC(range_s
) *optimized_out
;
343 get_value_arch (const struct value
*value
)
345 return get_type_arch (value_type (value
));
349 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
351 gdb_assert (!value
->lazy
);
353 return !ranges_contain (value
->unavailable
, offset
, length
);
357 value_bytes_available (const struct value
*value
,
358 LONGEST offset
, LONGEST length
)
360 return value_bits_available (value
,
361 offset
* TARGET_CHAR_BIT
,
362 length
* TARGET_CHAR_BIT
);
366 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
368 gdb_assert (!value
->lazy
);
370 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
374 value_entirely_available (struct value
*value
)
376 /* We can only tell whether the whole value is available when we try
379 value_fetch_lazy (value
);
381 if (VEC_empty (range_s
, value
->unavailable
))
386 /* Returns true if VALUE is entirely covered by RANGES. If the value
387 is lazy, it'll be read now. Note that RANGE is a pointer to
388 pointer because reading the value might change *RANGE. */
391 value_entirely_covered_by_range_vector (struct value
*value
,
392 VEC(range_s
) **ranges
)
394 /* We can only tell whether the whole value is optimized out /
395 unavailable when we try to read it. */
397 value_fetch_lazy (value
);
399 if (VEC_length (range_s
, *ranges
) == 1)
401 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
404 && t
->length
== (TARGET_CHAR_BIT
405 * TYPE_LENGTH (value_enclosing_type (value
))))
413 value_entirely_unavailable (struct value
*value
)
415 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
419 value_entirely_optimized_out (struct value
*value
)
421 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
424 /* Insert into the vector pointed to by VECTORP the bit range starting of
425 OFFSET bits, and extending for the next LENGTH bits. */
428 insert_into_bit_range_vector (VEC(range_s
) **vectorp
,
429 LONGEST offset
, LONGEST length
)
434 /* Insert the range sorted. If there's overlap or the new range
435 would be contiguous with an existing range, merge. */
437 newr
.offset
= offset
;
438 newr
.length
= length
;
440 /* Do a binary search for the position the given range would be
441 inserted if we only considered the starting OFFSET of ranges.
442 Call that position I. Since we also have LENGTH to care for
443 (this is a range afterall), we need to check if the _previous_
444 range overlaps the I range. E.g., calling R the new range:
446 #1 - overlaps with previous
450 |---| |---| |------| ... |--|
455 In the case #1 above, the binary search would return `I=1',
456 meaning, this OFFSET should be inserted at position 1, and the
457 current position 1 should be pushed further (and become 2). But,
458 note that `0' overlaps with R, so we want to merge them.
460 A similar consideration needs to be taken if the new range would
461 be contiguous with the previous range:
463 #2 - contiguous with previous
467 |--| |---| |------| ... |--|
472 If there's no overlap with the previous range, as in:
474 #3 - not overlapping and not contiguous
478 |--| |---| |------| ... |--|
485 #4 - R is the range with lowest offset
489 |--| |---| |------| ... |--|
494 ... we just push the new range to I.
496 All the 4 cases above need to consider that the new range may
497 also overlap several of the ranges that follow, or that R may be
498 contiguous with the following range, and merge. E.g.,
500 #5 - overlapping following ranges
503 |------------------------|
504 |--| |---| |------| ... |--|
513 |--| |---| |------| ... |--|
520 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
523 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
525 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
528 ULONGEST l
= std::min (bef
->offset
, offset
);
529 ULONGEST h
= std::max (bef
->offset
+ bef
->length
, offset
+ length
);
535 else if (offset
== bef
->offset
+ bef
->length
)
538 bef
->length
+= length
;
544 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
550 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
553 /* Check whether the ranges following the one we've just added or
554 touched can be folded in (#5 above). */
555 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
562 /* Get the range we just touched. */
563 t
= VEC_index (range_s
, *vectorp
, i
);
567 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
568 if (r
->offset
<= t
->offset
+ t
->length
)
572 l
= std::min (t
->offset
, r
->offset
);
573 h
= std::max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
582 /* If we couldn't merge this one, we won't be able to
583 merge following ones either, since the ranges are
584 always sorted by OFFSET. */
589 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
594 mark_value_bits_unavailable (struct value
*value
,
595 LONGEST offset
, LONGEST length
)
597 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
601 mark_value_bytes_unavailable (struct value
*value
,
602 LONGEST offset
, LONGEST length
)
604 mark_value_bits_unavailable (value
,
605 offset
* TARGET_CHAR_BIT
,
606 length
* TARGET_CHAR_BIT
);
609 /* Find the first range in RANGES that overlaps the range defined by
610 OFFSET and LENGTH, starting at element POS in the RANGES vector,
611 Returns the index into RANGES where such overlapping range was
612 found, or -1 if none was found. */
615 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
616 LONGEST offset
, LONGEST length
)
621 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
622 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
628 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
629 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
632 It must always be the case that:
633 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
635 It is assumed that memory can be accessed from:
636 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
638 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
639 / TARGET_CHAR_BIT) */
641 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
642 const gdb_byte
*ptr2
, size_t offset2_bits
,
645 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
646 == offset2_bits
% TARGET_CHAR_BIT
);
648 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
651 gdb_byte mask
, b1
, b2
;
653 /* The offset from the base pointers PTR1 and PTR2 is not a complete
654 number of bytes. A number of bits up to either the next exact
655 byte boundary, or LENGTH_BITS (which ever is sooner) will be
657 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
658 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
659 mask
= (1 << bits
) - 1;
661 if (length_bits
< bits
)
663 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
667 /* Now load the two bytes and mask off the bits we care about. */
668 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
669 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
674 /* Now update the length and offsets to take account of the bits
675 we've just compared. */
677 offset1_bits
+= bits
;
678 offset2_bits
+= bits
;
681 if (length_bits
% TARGET_CHAR_BIT
!= 0)
685 gdb_byte mask
, b1
, b2
;
687 /* The length is not an exact number of bytes. After the previous
688 IF.. block then the offsets are byte aligned, or the
689 length is zero (in which case this code is not reached). Compare
690 a number of bits at the end of the region, starting from an exact
692 bits
= length_bits
% TARGET_CHAR_BIT
;
693 o1
= offset1_bits
+ length_bits
- bits
;
694 o2
= offset2_bits
+ length_bits
- bits
;
696 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
697 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
699 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
700 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
702 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
703 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
713 /* We've now taken care of any stray "bits" at the start, or end of
714 the region to compare, the remainder can be covered with a simple
716 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
717 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
718 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
720 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
721 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
722 length_bits
/ TARGET_CHAR_BIT
);
725 /* Length is zero, regions match. */
729 /* Helper struct for find_first_range_overlap_and_match and
730 value_contents_bits_eq. Keep track of which slot of a given ranges
731 vector have we last looked at. */
733 struct ranges_and_idx
736 VEC(range_s
) *ranges
;
738 /* The range we've last found in RANGES. Given ranges are sorted,
739 we can start the next lookup here. */
743 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
744 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
745 ranges starting at OFFSET2 bits. Return true if the ranges match
746 and fill in *L and *H with the overlapping window relative to
747 (both) OFFSET1 or OFFSET2. */
750 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
751 struct ranges_and_idx
*rp2
,
752 LONGEST offset1
, LONGEST offset2
,
753 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
755 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
757 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
760 if (rp1
->idx
== -1 && rp2
->idx
== -1)
766 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
774 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
775 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
777 /* Get the unavailable windows intersected by the incoming
778 ranges. The first and last ranges that overlap the argument
779 range may be wider than said incoming arguments ranges. */
780 l1
= std::max (offset1
, r1
->offset
);
781 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
783 l2
= std::max (offset2
, r2
->offset
);
784 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
786 /* Make them relative to the respective start offsets, so we can
787 compare them for equality. */
794 /* Different ranges, no match. */
795 if (l1
!= l2
|| h1
!= h2
)
804 /* Helper function for value_contents_eq. The only difference is that
805 this function is bit rather than byte based.
807 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
808 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
809 Return true if the available bits match. */
812 value_contents_bits_eq (const struct value
*val1
, int offset1
,
813 const struct value
*val2
, int offset2
,
816 /* Each array element corresponds to a ranges source (unavailable,
817 optimized out). '1' is for VAL1, '2' for VAL2. */
818 struct ranges_and_idx rp1
[2], rp2
[2];
820 /* See function description in value.h. */
821 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
823 /* We shouldn't be trying to compare past the end of the values. */
824 gdb_assert (offset1
+ length
825 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
826 gdb_assert (offset2
+ length
827 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
829 memset (&rp1
, 0, sizeof (rp1
));
830 memset (&rp2
, 0, sizeof (rp2
));
831 rp1
[0].ranges
= val1
->unavailable
;
832 rp2
[0].ranges
= val2
->unavailable
;
833 rp1
[1].ranges
= val1
->optimized_out
;
834 rp2
[1].ranges
= val2
->optimized_out
;
838 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
841 for (i
= 0; i
< 2; i
++)
843 ULONGEST l_tmp
, h_tmp
;
845 /* The contents only match equal if the invalid/unavailable
846 contents ranges match as well. */
847 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
848 offset1
, offset2
, length
,
852 /* We're interested in the lowest/first range found. */
853 if (i
== 0 || l_tmp
< l
)
860 /* Compare the available/valid contents. */
861 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
862 val2
->contents
, offset2
, l
) != 0)
874 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
875 const struct value
*val2
, LONGEST offset2
,
878 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
879 val2
, offset2
* TARGET_CHAR_BIT
,
880 length
* TARGET_CHAR_BIT
);
884 /* The value-history records all the values printed by print commands
885 during this session. */
887 static std::vector
<value_ref_ptr
> value_history
;
890 /* List of all value objects currently allocated
891 (except for those released by calls to release_value)
892 This is so they can be freed after each command. */
894 static struct value
*all_values
;
896 /* Allocate a lazy value for type TYPE. Its actual content is
897 "lazily" allocated too: the content field of the return value is
898 NULL; it will be allocated when it is fetched from the target. */
901 allocate_value_lazy (struct type
*type
)
905 /* Call check_typedef on our type to make sure that, if TYPE
906 is a TYPE_CODE_TYPEDEF, its length is set to the length
907 of the target type instead of zero. However, we do not
908 replace the typedef type by the target type, because we want
909 to keep the typedef in order to be able to set the VAL's type
910 description correctly. */
911 check_typedef (type
);
913 val
= XCNEW (struct value
);
914 val
->contents
= NULL
;
915 val
->next
= all_values
;
918 val
->enclosing_type
= type
;
919 VALUE_LVAL (val
) = not_lval
;
920 val
->location
.address
= 0;
925 val
->embedded_offset
= 0;
926 val
->pointed_to_offset
= 0;
928 val
->initialized
= 1; /* Default to initialized. */
930 /* Values start out on the all_values chain. */
931 val
->reference_count
= 1;
936 /* The maximum size, in bytes, that GDB will try to allocate for a value.
937 The initial value of 64k was not selected for any specific reason, it is
938 just a reasonable starting point. */
940 static int max_value_size
= 65536; /* 64k bytes */
942 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
943 LONGEST, otherwise GDB will not be able to parse integer values from the
944 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
945 be unable to parse "set max-value-size 2".
947 As we want a consistent GDB experience across hosts with different sizes
948 of LONGEST, this arbitrary minimum value was selected, so long as this
949 is bigger than LONGEST on all GDB supported hosts we're fine. */
951 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
952 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
954 /* Implement the "set max-value-size" command. */
957 set_max_value_size (const char *args
, int from_tty
,
958 struct cmd_list_element
*c
)
960 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
962 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
964 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
965 error (_("max-value-size set too low, increasing to %d bytes"),
970 /* Implement the "show max-value-size" command. */
973 show_max_value_size (struct ui_file
*file
, int from_tty
,
974 struct cmd_list_element
*c
, const char *value
)
976 if (max_value_size
== -1)
977 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
979 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
983 /* Called before we attempt to allocate or reallocate a buffer for the
984 contents of a value. TYPE is the type of the value for which we are
985 allocating the buffer. If the buffer is too large (based on the user
986 controllable setting) then throw an error. If this function returns
987 then we should attempt to allocate the buffer. */
990 check_type_length_before_alloc (const struct type
*type
)
992 unsigned int length
= TYPE_LENGTH (type
);
994 if (max_value_size
> -1 && length
> max_value_size
)
996 if (TYPE_NAME (type
) != NULL
)
997 error (_("value of type `%s' requires %u bytes, which is more "
998 "than max-value-size"), TYPE_NAME (type
), length
);
1000 error (_("value requires %u bytes, which is more than "
1001 "max-value-size"), length
);
1005 /* Allocate the contents of VAL if it has not been allocated yet. */
1008 allocate_value_contents (struct value
*val
)
1012 check_type_length_before_alloc (val
->enclosing_type
);
1014 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1018 /* Allocate a value and its contents for type TYPE. */
1021 allocate_value (struct type
*type
)
1023 struct value
*val
= allocate_value_lazy (type
);
1025 allocate_value_contents (val
);
1030 /* Allocate a value that has the correct length
1031 for COUNT repetitions of type TYPE. */
1034 allocate_repeat_value (struct type
*type
, int count
)
1036 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1037 /* FIXME-type-allocation: need a way to free this type when we are
1039 struct type
*array_type
1040 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1042 return allocate_value (array_type
);
1046 allocate_computed_value (struct type
*type
,
1047 const struct lval_funcs
*funcs
,
1050 struct value
*v
= allocate_value_lazy (type
);
1052 VALUE_LVAL (v
) = lval_computed
;
1053 v
->location
.computed
.funcs
= funcs
;
1054 v
->location
.computed
.closure
= closure
;
1059 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1062 allocate_optimized_out_value (struct type
*type
)
1064 struct value
*retval
= allocate_value_lazy (type
);
1066 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1067 set_value_lazy (retval
, 0);
1071 /* Accessor methods. */
1074 value_next (const struct value
*value
)
1080 value_type (const struct value
*value
)
1085 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1091 value_offset (const struct value
*value
)
1093 return value
->offset
;
1096 set_value_offset (struct value
*value
, LONGEST offset
)
1098 value
->offset
= offset
;
1102 value_bitpos (const struct value
*value
)
1104 return value
->bitpos
;
1107 set_value_bitpos (struct value
*value
, LONGEST bit
)
1109 value
->bitpos
= bit
;
1113 value_bitsize (const struct value
*value
)
1115 return value
->bitsize
;
1118 set_value_bitsize (struct value
*value
, LONGEST bit
)
1120 value
->bitsize
= bit
;
1124 value_parent (const struct value
*value
)
1126 return value
->parent
;
1132 set_value_parent (struct value
*value
, struct value
*parent
)
1134 struct value
*old
= value
->parent
;
1136 value
->parent
= parent
;
1138 value_incref (parent
);
1143 value_contents_raw (struct value
*value
)
1145 struct gdbarch
*arch
= get_value_arch (value
);
1146 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1148 allocate_value_contents (value
);
1149 return value
->contents
+ value
->embedded_offset
* unit_size
;
1153 value_contents_all_raw (struct value
*value
)
1155 allocate_value_contents (value
);
1156 return value
->contents
;
1160 value_enclosing_type (const struct value
*value
)
1162 return value
->enclosing_type
;
1165 /* Look at value.h for description. */
1168 value_actual_type (struct value
*value
, int resolve_simple_types
,
1169 int *real_type_found
)
1171 struct value_print_options opts
;
1172 struct type
*result
;
1174 get_user_print_options (&opts
);
1176 if (real_type_found
)
1177 *real_type_found
= 0;
1178 result
= value_type (value
);
1179 if (opts
.objectprint
)
1181 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1182 fetch its rtti type. */
1183 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1184 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1186 && !value_optimized_out (value
))
1188 struct type
*real_type
;
1190 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1193 if (real_type_found
)
1194 *real_type_found
= 1;
1198 else if (resolve_simple_types
)
1200 if (real_type_found
)
1201 *real_type_found
= 1;
1202 result
= value_enclosing_type (value
);
1210 error_value_optimized_out (void)
1212 error (_("value has been optimized out"));
1216 require_not_optimized_out (const struct value
*value
)
1218 if (!VEC_empty (range_s
, value
->optimized_out
))
1220 if (value
->lval
== lval_register
)
1221 error (_("register has not been saved in frame"));
1223 error_value_optimized_out ();
1228 require_available (const struct value
*value
)
1230 if (!VEC_empty (range_s
, value
->unavailable
))
1231 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1235 value_contents_for_printing (struct value
*value
)
1238 value_fetch_lazy (value
);
1239 return value
->contents
;
1243 value_contents_for_printing_const (const struct value
*value
)
1245 gdb_assert (!value
->lazy
);
1246 return value
->contents
;
1250 value_contents_all (struct value
*value
)
1252 const gdb_byte
*result
= value_contents_for_printing (value
);
1253 require_not_optimized_out (value
);
1254 require_available (value
);
1258 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1259 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1262 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1263 VEC (range_s
) *src_range
, int src_bit_offset
,
1269 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1273 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1274 h
= std::min (r
->offset
+ r
->length
,
1275 (LONGEST
) src_bit_offset
+ bit_length
);
1278 insert_into_bit_range_vector (dst_range
,
1279 dst_bit_offset
+ (l
- src_bit_offset
),
1284 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1285 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1288 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1289 const struct value
*src
, int src_bit_offset
,
1292 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1293 src
->unavailable
, src_bit_offset
,
1295 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1296 src
->optimized_out
, src_bit_offset
,
1300 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1301 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1302 contents, starting at DST_OFFSET. If unavailable contents are
1303 being copied from SRC, the corresponding DST contents are marked
1304 unavailable accordingly. Neither DST nor SRC may be lazy
1307 It is assumed the contents of DST in the [DST_OFFSET,
1308 DST_OFFSET+LENGTH) range are wholly available. */
1311 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1312 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1314 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1315 struct gdbarch
*arch
= get_value_arch (src
);
1316 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1318 /* A lazy DST would make that this copy operation useless, since as
1319 soon as DST's contents were un-lazied (by a later value_contents
1320 call, say), the contents would be overwritten. A lazy SRC would
1321 mean we'd be copying garbage. */
1322 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1324 /* The overwritten DST range gets unavailability ORed in, not
1325 replaced. Make sure to remember to implement replacing if it
1326 turns out actually necessary. */
1327 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1328 gdb_assert (!value_bits_any_optimized_out (dst
,
1329 TARGET_CHAR_BIT
* dst_offset
,
1330 TARGET_CHAR_BIT
* length
));
1332 /* Copy the data. */
1333 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1334 value_contents_all_raw (src
) + src_offset
* unit_size
,
1335 length
* unit_size
);
1337 /* Copy the meta-data, adjusted. */
1338 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1339 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1340 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1342 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1343 src
, src_bit_offset
,
1347 /* Copy LENGTH bytes of SRC value's (all) contents
1348 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1349 (all) contents, starting at DST_OFFSET. If unavailable contents
1350 are being copied from SRC, the corresponding DST contents are
1351 marked unavailable accordingly. DST must not be lazy. If SRC is
1352 lazy, it will be fetched now.
1354 It is assumed the contents of DST in the [DST_OFFSET,
1355 DST_OFFSET+LENGTH) range are wholly available. */
1358 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1359 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1362 value_fetch_lazy (src
);
1364 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1368 value_lazy (const struct value
*value
)
1374 set_value_lazy (struct value
*value
, int val
)
1380 value_stack (const struct value
*value
)
1382 return value
->stack
;
1386 set_value_stack (struct value
*value
, int val
)
1392 value_contents (struct value
*value
)
1394 const gdb_byte
*result
= value_contents_writeable (value
);
1395 require_not_optimized_out (value
);
1396 require_available (value
);
1401 value_contents_writeable (struct value
*value
)
1404 value_fetch_lazy (value
);
1405 return value_contents_raw (value
);
1409 value_optimized_out (struct value
*value
)
1411 /* We can only know if a value is optimized out once we have tried to
1413 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1417 value_fetch_lazy (value
);
1419 CATCH (ex
, RETURN_MASK_ERROR
)
1421 /* Fall back to checking value->optimized_out. */
1426 return !VEC_empty (range_s
, value
->optimized_out
);
1429 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1430 the following LENGTH bytes. */
1433 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1435 mark_value_bits_optimized_out (value
,
1436 offset
* TARGET_CHAR_BIT
,
1437 length
* TARGET_CHAR_BIT
);
1443 mark_value_bits_optimized_out (struct value
*value
,
1444 LONGEST offset
, LONGEST length
)
1446 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1450 value_bits_synthetic_pointer (const struct value
*value
,
1451 LONGEST offset
, LONGEST length
)
1453 if (value
->lval
!= lval_computed
1454 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1456 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1462 value_embedded_offset (const struct value
*value
)
1464 return value
->embedded_offset
;
1468 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1470 value
->embedded_offset
= val
;
1474 value_pointed_to_offset (const struct value
*value
)
1476 return value
->pointed_to_offset
;
1480 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1482 value
->pointed_to_offset
= val
;
1485 const struct lval_funcs
*
1486 value_computed_funcs (const struct value
*v
)
1488 gdb_assert (value_lval_const (v
) == lval_computed
);
1490 return v
->location
.computed
.funcs
;
1494 value_computed_closure (const struct value
*v
)
1496 gdb_assert (v
->lval
== lval_computed
);
1498 return v
->location
.computed
.closure
;
1502 deprecated_value_lval_hack (struct value
*value
)
1504 return &value
->lval
;
1508 value_lval_const (const struct value
*value
)
1514 value_address (const struct value
*value
)
1516 if (value
->lval
!= lval_memory
)
1518 if (value
->parent
!= NULL
)
1519 return value_address (value
->parent
) + value
->offset
;
1520 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1522 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1523 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1526 return value
->location
.address
+ value
->offset
;
1530 value_raw_address (const struct value
*value
)
1532 if (value
->lval
!= lval_memory
)
1534 return value
->location
.address
;
1538 set_value_address (struct value
*value
, CORE_ADDR addr
)
1540 gdb_assert (value
->lval
== lval_memory
);
1541 value
->location
.address
= addr
;
1544 struct internalvar
**
1545 deprecated_value_internalvar_hack (struct value
*value
)
1547 return &value
->location
.internalvar
;
1551 deprecated_value_next_frame_id_hack (struct value
*value
)
1553 gdb_assert (value
->lval
== lval_register
);
1554 return &value
->location
.reg
.next_frame_id
;
1558 deprecated_value_regnum_hack (struct value
*value
)
1560 gdb_assert (value
->lval
== lval_register
);
1561 return &value
->location
.reg
.regnum
;
1565 deprecated_value_modifiable (const struct value
*value
)
1567 return value
->modifiable
;
1570 /* Return a mark in the value chain. All values allocated after the
1571 mark is obtained (except for those released) are subject to being freed
1572 if a subsequent value_free_to_mark is passed the mark. */
1579 /* Take a reference to VAL. VAL will not be deallocated until all
1580 references are released. */
1583 value_incref (struct value
*val
)
1585 val
->reference_count
++;
1589 /* Release a reference to VAL, which was acquired with value_incref.
1590 This function is also called to deallocate values from the value
1594 value_decref (struct value
*val
)
1598 gdb_assert (val
->reference_count
> 0);
1599 val
->reference_count
--;
1600 if (val
->reference_count
> 0)
1603 /* If there's an associated parent value, drop our reference to
1605 if (val
->parent
!= NULL
)
1606 value_decref (val
->parent
);
1608 if (VALUE_LVAL (val
) == lval_computed
)
1610 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1612 if (funcs
->free_closure
)
1613 funcs
->free_closure (val
);
1615 else if (VALUE_LVAL (val
) == lval_xcallable
)
1616 delete val
->location
.xm_worker
;
1618 xfree (val
->contents
);
1619 VEC_free (range_s
, val
->unavailable
);
1624 /* Free all values allocated since MARK was obtained by value_mark
1625 (except for those released). */
1627 value_free_to_mark (const struct value
*mark
)
1632 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1641 /* Frees all the elements in a chain of values. */
1644 free_value_chain (struct value
*v
)
1650 next
= value_next (v
);
1655 /* Remove VAL from the chain all_values
1656 so it will not be freed automatically. */
1659 release_value (struct value
*val
)
1662 bool released
= false;
1665 return value_ref_ptr ();
1667 if (all_values
== val
)
1669 all_values
= val
->next
;
1675 for (v
= all_values
; v
; v
= v
->next
)
1679 v
->next
= val
->next
;
1689 /* We must always return an owned reference. Normally this
1690 happens because we transfer the reference from the value
1691 chain, but in this case the value was not on the chain. */
1695 return value_ref_ptr (val
);
1698 /* Release all values up to mark */
1700 value_release_to_mark (const struct value
*mark
)
1705 for (val
= next
= all_values
; next
; next
= next
->next
)
1707 if (next
->next
== mark
)
1709 all_values
= next
->next
;
1719 /* Return a copy of the value ARG.
1720 It contains the same contents, for same memory address,
1721 but it's a different block of storage. */
1724 value_copy (struct value
*arg
)
1726 struct type
*encl_type
= value_enclosing_type (arg
);
1729 if (value_lazy (arg
))
1730 val
= allocate_value_lazy (encl_type
);
1732 val
= allocate_value (encl_type
);
1733 val
->type
= arg
->type
;
1734 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1735 val
->location
= arg
->location
;
1736 val
->offset
= arg
->offset
;
1737 val
->bitpos
= arg
->bitpos
;
1738 val
->bitsize
= arg
->bitsize
;
1739 val
->lazy
= arg
->lazy
;
1740 val
->embedded_offset
= value_embedded_offset (arg
);
1741 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1742 val
->modifiable
= arg
->modifiable
;
1743 if (!value_lazy (val
))
1745 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1746 TYPE_LENGTH (value_enclosing_type (arg
)));
1749 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1750 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1751 set_value_parent (val
, arg
->parent
);
1752 if (VALUE_LVAL (val
) == lval_computed
)
1754 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1756 if (funcs
->copy_closure
)
1757 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1762 /* Return a "const" and/or "volatile" qualified version of the value V.
1763 If CNST is true, then the returned value will be qualified with
1765 if VOLTL is true, then the returned value will be qualified with
1769 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1771 struct type
*val_type
= value_type (v
);
1772 struct type
*enclosing_type
= value_enclosing_type (v
);
1773 struct value
*cv_val
= value_copy (v
);
1775 deprecated_set_value_type (cv_val
,
1776 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1777 set_value_enclosing_type (cv_val
,
1778 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1783 /* Return a version of ARG that is non-lvalue. */
1786 value_non_lval (struct value
*arg
)
1788 if (VALUE_LVAL (arg
) != not_lval
)
1790 struct type
*enc_type
= value_enclosing_type (arg
);
1791 struct value
*val
= allocate_value (enc_type
);
1793 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1794 TYPE_LENGTH (enc_type
));
1795 val
->type
= arg
->type
;
1796 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1797 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1803 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1806 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1808 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1810 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1811 v
->lval
= lval_memory
;
1812 v
->location
.address
= addr
;
1816 set_value_component_location (struct value
*component
,
1817 const struct value
*whole
)
1821 gdb_assert (whole
->lval
!= lval_xcallable
);
1823 if (whole
->lval
== lval_internalvar
)
1824 VALUE_LVAL (component
) = lval_internalvar_component
;
1826 VALUE_LVAL (component
) = whole
->lval
;
1828 component
->location
= whole
->location
;
1829 if (whole
->lval
== lval_computed
)
1831 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1833 if (funcs
->copy_closure
)
1834 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1837 /* If type has a dynamic resolved location property
1838 update it's value address. */
1839 type
= value_type (whole
);
1840 if (NULL
!= TYPE_DATA_LOCATION (type
)
1841 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1842 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1845 /* Access to the value history. */
1847 /* Record a new value in the value history.
1848 Returns the absolute history index of the entry. */
1851 record_latest_value (struct value
*val
)
1855 /* We don't want this value to have anything to do with the inferior anymore.
1856 In particular, "set $1 = 50" should not affect the variable from which
1857 the value was taken, and fast watchpoints should be able to assume that
1858 a value on the value history never changes. */
1859 if (value_lazy (val
))
1860 value_fetch_lazy (val
);
1861 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1862 from. This is a bit dubious, because then *&$1 does not just return $1
1863 but the current contents of that location. c'est la vie... */
1864 val
->modifiable
= 0;
1866 value_history
.push_back (release_value (val
));
1868 return value_history
.size ();
1871 /* Return a copy of the value in the history with sequence number NUM. */
1874 access_value_history (int num
)
1880 absnum
+= value_history
.size ();
1885 error (_("The history is empty."));
1887 error (_("There is only one value in the history."));
1889 error (_("History does not go back to $$%d."), -num
);
1891 if (absnum
> value_history
.size ())
1892 error (_("History has not yet reached $%d."), absnum
);
1896 return value_copy (value_history
[absnum
].get ());
1900 show_values (const char *num_exp
, int from_tty
)
1908 /* "show values +" should print from the stored position.
1909 "show values <exp>" should print around value number <exp>. */
1910 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1911 num
= parse_and_eval_long (num_exp
) - 5;
1915 /* "show values" means print the last 10 values. */
1916 num
= value_history
.size () - 9;
1922 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1924 struct value_print_options opts
;
1926 val
= access_value_history (i
);
1927 printf_filtered (("$%d = "), i
);
1928 get_user_print_options (&opts
);
1929 value_print (val
, gdb_stdout
, &opts
);
1930 printf_filtered (("\n"));
1933 /* The next "show values +" should start after what we just printed. */
1936 /* Hitting just return after this command should do the same thing as
1937 "show values +". If num_exp is null, this is unnecessary, since
1938 "show values +" is not useful after "show values". */
1939 if (from_tty
&& num_exp
)
1940 set_repeat_arguments ("+");
1943 enum internalvar_kind
1945 /* The internal variable is empty. */
1948 /* The value of the internal variable is provided directly as
1949 a GDB value object. */
1952 /* A fresh value is computed via a call-back routine on every
1953 access to the internal variable. */
1954 INTERNALVAR_MAKE_VALUE
,
1956 /* The internal variable holds a GDB internal convenience function. */
1957 INTERNALVAR_FUNCTION
,
1959 /* The variable holds an integer value. */
1960 INTERNALVAR_INTEGER
,
1962 /* The variable holds a GDB-provided string. */
1966 union internalvar_data
1968 /* A value object used with INTERNALVAR_VALUE. */
1969 struct value
*value
;
1971 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1974 /* The functions to call. */
1975 const struct internalvar_funcs
*functions
;
1977 /* The function's user-data. */
1981 /* The internal function used with INTERNALVAR_FUNCTION. */
1984 struct internal_function
*function
;
1985 /* True if this is the canonical name for the function. */
1989 /* An integer value used with INTERNALVAR_INTEGER. */
1992 /* If type is non-NULL, it will be used as the type to generate
1993 a value for this internal variable. If type is NULL, a default
1994 integer type for the architecture is used. */
1999 /* A string value used with INTERNALVAR_STRING. */
2003 /* Internal variables. These are variables within the debugger
2004 that hold values assigned by debugger commands.
2005 The user refers to them with a '$' prefix
2006 that does not appear in the variable names stored internally. */
2010 struct internalvar
*next
;
2013 /* We support various different kinds of content of an internal variable.
2014 enum internalvar_kind specifies the kind, and union internalvar_data
2015 provides the data associated with this particular kind. */
2017 enum internalvar_kind kind
;
2019 union internalvar_data u
;
2022 static struct internalvar
*internalvars
;
2024 /* If the variable does not already exist create it and give it the
2025 value given. If no value is given then the default is zero. */
2027 init_if_undefined_command (const char* args
, int from_tty
)
2029 struct internalvar
* intvar
;
2031 /* Parse the expression - this is taken from set_command(). */
2032 expression_up expr
= parse_expression (args
);
2034 /* Validate the expression.
2035 Was the expression an assignment?
2036 Or even an expression at all? */
2037 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2038 error (_("Init-if-undefined requires an assignment expression."));
2040 /* Extract the variable from the parsed expression.
2041 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2042 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2043 error (_("The first parameter to init-if-undefined "
2044 "should be a GDB variable."));
2045 intvar
= expr
->elts
[2].internalvar
;
2047 /* Only evaluate the expression if the lvalue is void.
2048 This may still fail if the expresssion is invalid. */
2049 if (intvar
->kind
== INTERNALVAR_VOID
)
2050 evaluate_expression (expr
.get ());
2054 /* Look up an internal variable with name NAME. NAME should not
2055 normally include a dollar sign.
2057 If the specified internal variable does not exist,
2058 the return value is NULL. */
2060 struct internalvar
*
2061 lookup_only_internalvar (const char *name
)
2063 struct internalvar
*var
;
2065 for (var
= internalvars
; var
; var
= var
->next
)
2066 if (strcmp (var
->name
, name
) == 0)
2072 /* Complete NAME by comparing it to the names of internal
2076 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2078 struct internalvar
*var
;
2081 len
= strlen (name
);
2083 for (var
= internalvars
; var
; var
= var
->next
)
2084 if (strncmp (var
->name
, name
, len
) == 0)
2086 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2088 tracker
.add_completion (std::move (copy
));
2092 /* Create an internal variable with name NAME and with a void value.
2093 NAME should not normally include a dollar sign. */
2095 struct internalvar
*
2096 create_internalvar (const char *name
)
2098 struct internalvar
*var
= XNEW (struct internalvar
);
2100 var
->name
= concat (name
, (char *)NULL
);
2101 var
->kind
= INTERNALVAR_VOID
;
2102 var
->next
= internalvars
;
2107 /* Create an internal variable with name NAME and register FUN as the
2108 function that value_of_internalvar uses to create a value whenever
2109 this variable is referenced. NAME should not normally include a
2110 dollar sign. DATA is passed uninterpreted to FUN when it is
2111 called. CLEANUP, if not NULL, is called when the internal variable
2112 is destroyed. It is passed DATA as its only argument. */
2114 struct internalvar
*
2115 create_internalvar_type_lazy (const char *name
,
2116 const struct internalvar_funcs
*funcs
,
2119 struct internalvar
*var
= create_internalvar (name
);
2121 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2122 var
->u
.make_value
.functions
= funcs
;
2123 var
->u
.make_value
.data
= data
;
2127 /* See documentation in value.h. */
2130 compile_internalvar_to_ax (struct internalvar
*var
,
2131 struct agent_expr
*expr
,
2132 struct axs_value
*value
)
2134 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2135 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2138 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2139 var
->u
.make_value
.data
);
2143 /* Look up an internal variable with name NAME. NAME should not
2144 normally include a dollar sign.
2146 If the specified internal variable does not exist,
2147 one is created, with a void value. */
2149 struct internalvar
*
2150 lookup_internalvar (const char *name
)
2152 struct internalvar
*var
;
2154 var
= lookup_only_internalvar (name
);
2158 return create_internalvar (name
);
2161 /* Return current value of internal variable VAR. For variables that
2162 are not inherently typed, use a value type appropriate for GDBARCH. */
2165 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2168 struct trace_state_variable
*tsv
;
2170 /* If there is a trace state variable of the same name, assume that
2171 is what we really want to see. */
2172 tsv
= find_trace_state_variable (var
->name
);
2175 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2177 if (tsv
->value_known
)
2178 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2181 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2187 case INTERNALVAR_VOID
:
2188 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2191 case INTERNALVAR_FUNCTION
:
2192 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2195 case INTERNALVAR_INTEGER
:
2196 if (!var
->u
.integer
.type
)
2197 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2198 var
->u
.integer
.val
);
2200 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2203 case INTERNALVAR_STRING
:
2204 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2205 builtin_type (gdbarch
)->builtin_char
);
2208 case INTERNALVAR_VALUE
:
2209 val
= value_copy (var
->u
.value
);
2210 if (value_lazy (val
))
2211 value_fetch_lazy (val
);
2214 case INTERNALVAR_MAKE_VALUE
:
2215 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2216 var
->u
.make_value
.data
);
2220 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2223 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2224 on this value go back to affect the original internal variable.
2226 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2227 no underlying modifyable state in the internal variable.
2229 Likewise, if the variable's value is a computed lvalue, we want
2230 references to it to produce another computed lvalue, where
2231 references and assignments actually operate through the
2232 computed value's functions.
2234 This means that internal variables with computed values
2235 behave a little differently from other internal variables:
2236 assignments to them don't just replace the previous value
2237 altogether. At the moment, this seems like the behavior we
2240 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2241 && val
->lval
!= lval_computed
)
2243 VALUE_LVAL (val
) = lval_internalvar
;
2244 VALUE_INTERNALVAR (val
) = var
;
2251 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2253 if (var
->kind
== INTERNALVAR_INTEGER
)
2255 *result
= var
->u
.integer
.val
;
2259 if (var
->kind
== INTERNALVAR_VALUE
)
2261 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2263 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2265 *result
= value_as_long (var
->u
.value
);
2274 get_internalvar_function (struct internalvar
*var
,
2275 struct internal_function
**result
)
2279 case INTERNALVAR_FUNCTION
:
2280 *result
= var
->u
.fn
.function
;
2289 set_internalvar_component (struct internalvar
*var
,
2290 LONGEST offset
, LONGEST bitpos
,
2291 LONGEST bitsize
, struct value
*newval
)
2294 struct gdbarch
*arch
;
2299 case INTERNALVAR_VALUE
:
2300 addr
= value_contents_writeable (var
->u
.value
);
2301 arch
= get_value_arch (var
->u
.value
);
2302 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2305 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2306 value_as_long (newval
), bitpos
, bitsize
);
2308 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2309 TYPE_LENGTH (value_type (newval
)));
2313 /* We can never get a component of any other kind. */
2314 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2319 set_internalvar (struct internalvar
*var
, struct value
*val
)
2321 enum internalvar_kind new_kind
;
2322 union internalvar_data new_data
= { 0 };
2324 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2325 error (_("Cannot overwrite convenience function %s"), var
->name
);
2327 /* Prepare new contents. */
2328 switch (TYPE_CODE (check_typedef (value_type (val
))))
2330 case TYPE_CODE_VOID
:
2331 new_kind
= INTERNALVAR_VOID
;
2334 case TYPE_CODE_INTERNAL_FUNCTION
:
2335 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2336 new_kind
= INTERNALVAR_FUNCTION
;
2337 get_internalvar_function (VALUE_INTERNALVAR (val
),
2338 &new_data
.fn
.function
);
2339 /* Copies created here are never canonical. */
2343 new_kind
= INTERNALVAR_VALUE
;
2344 new_data
.value
= value_copy (val
);
2345 new_data
.value
->modifiable
= 1;
2347 /* Force the value to be fetched from the target now, to avoid problems
2348 later when this internalvar is referenced and the target is gone or
2350 if (value_lazy (new_data
.value
))
2351 value_fetch_lazy (new_data
.value
);
2353 /* Release the value from the value chain to prevent it from being
2354 deleted by free_all_values. From here on this function should not
2355 call error () until new_data is installed into the var->u to avoid
2357 release_value (new_data
.value
).release ();
2359 /* Internal variables which are created from values with a dynamic
2360 location don't need the location property of the origin anymore.
2361 The resolved dynamic location is used prior then any other address
2362 when accessing the value.
2363 If we keep it, we would still refer to the origin value.
2364 Remove the location property in case it exist. */
2365 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2370 /* Clean up old contents. */
2371 clear_internalvar (var
);
2374 var
->kind
= new_kind
;
2376 /* End code which must not call error(). */
2380 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2382 /* Clean up old contents. */
2383 clear_internalvar (var
);
2385 var
->kind
= INTERNALVAR_INTEGER
;
2386 var
->u
.integer
.type
= NULL
;
2387 var
->u
.integer
.val
= l
;
2391 set_internalvar_string (struct internalvar
*var
, const char *string
)
2393 /* Clean up old contents. */
2394 clear_internalvar (var
);
2396 var
->kind
= INTERNALVAR_STRING
;
2397 var
->u
.string
= xstrdup (string
);
2401 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2403 /* Clean up old contents. */
2404 clear_internalvar (var
);
2406 var
->kind
= INTERNALVAR_FUNCTION
;
2407 var
->u
.fn
.function
= f
;
2408 var
->u
.fn
.canonical
= 1;
2409 /* Variables installed here are always the canonical version. */
2413 clear_internalvar (struct internalvar
*var
)
2415 /* Clean up old contents. */
2418 case INTERNALVAR_VALUE
:
2419 value_decref (var
->u
.value
);
2422 case INTERNALVAR_STRING
:
2423 xfree (var
->u
.string
);
2426 case INTERNALVAR_MAKE_VALUE
:
2427 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2428 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2435 /* Reset to void kind. */
2436 var
->kind
= INTERNALVAR_VOID
;
2440 internalvar_name (const struct internalvar
*var
)
2445 static struct internal_function
*
2446 create_internal_function (const char *name
,
2447 internal_function_fn handler
, void *cookie
)
2449 struct internal_function
*ifn
= XNEW (struct internal_function
);
2451 ifn
->name
= xstrdup (name
);
2452 ifn
->handler
= handler
;
2453 ifn
->cookie
= cookie
;
2458 value_internal_function_name (struct value
*val
)
2460 struct internal_function
*ifn
;
2463 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2464 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2465 gdb_assert (result
);
2471 call_internal_function (struct gdbarch
*gdbarch
,
2472 const struct language_defn
*language
,
2473 struct value
*func
, int argc
, struct value
**argv
)
2475 struct internal_function
*ifn
;
2478 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2479 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2480 gdb_assert (result
);
2482 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2485 /* The 'function' command. This does nothing -- it is just a
2486 placeholder to let "help function NAME" work. This is also used as
2487 the implementation of the sub-command that is created when
2488 registering an internal function. */
2490 function_command (const char *command
, int from_tty
)
2495 /* Clean up if an internal function's command is destroyed. */
2497 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2499 xfree ((char *) self
->name
);
2500 xfree ((char *) self
->doc
);
2503 /* Add a new internal function. NAME is the name of the function; DOC
2504 is a documentation string describing the function. HANDLER is
2505 called when the function is invoked. COOKIE is an arbitrary
2506 pointer which is passed to HANDLER and is intended for "user
2509 add_internal_function (const char *name
, const char *doc
,
2510 internal_function_fn handler
, void *cookie
)
2512 struct cmd_list_element
*cmd
;
2513 struct internal_function
*ifn
;
2514 struct internalvar
*var
= lookup_internalvar (name
);
2516 ifn
= create_internal_function (name
, handler
, cookie
);
2517 set_internalvar_function (var
, ifn
);
2519 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2521 cmd
->destroyer
= function_destroyer
;
2524 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2525 prevent cycles / duplicates. */
2528 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2529 htab_t copied_types
)
2531 if (TYPE_OBJFILE (value
->type
) == objfile
)
2532 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2534 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2535 value
->enclosing_type
= copy_type_recursive (objfile
,
2536 value
->enclosing_type
,
2540 /* Likewise for internal variable VAR. */
2543 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2544 htab_t copied_types
)
2548 case INTERNALVAR_INTEGER
:
2549 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2551 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2554 case INTERNALVAR_VALUE
:
2555 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2560 /* Update the internal variables and value history when OBJFILE is
2561 discarded; we must copy the types out of the objfile. New global types
2562 will be created for every convenience variable which currently points to
2563 this objfile's types, and the convenience variables will be adjusted to
2564 use the new global types. */
2567 preserve_values (struct objfile
*objfile
)
2569 htab_t copied_types
;
2570 struct internalvar
*var
;
2573 /* Create the hash table. We allocate on the objfile's obstack, since
2574 it is soon to be deleted. */
2575 copied_types
= create_copied_types_hash (objfile
);
2577 for (const value_ref_ptr
&item
: value_history
)
2578 preserve_one_value (item
.get (), objfile
, copied_types
);
2580 for (var
= internalvars
; var
; var
= var
->next
)
2581 preserve_one_internalvar (var
, objfile
, copied_types
);
2583 preserve_ext_lang_values (objfile
, copied_types
);
2585 htab_delete (copied_types
);
2589 show_convenience (const char *ignore
, int from_tty
)
2591 struct gdbarch
*gdbarch
= get_current_arch ();
2592 struct internalvar
*var
;
2594 struct value_print_options opts
;
2596 get_user_print_options (&opts
);
2597 for (var
= internalvars
; var
; var
= var
->next
)
2604 printf_filtered (("$%s = "), var
->name
);
2610 val
= value_of_internalvar (gdbarch
, var
);
2611 value_print (val
, gdb_stdout
, &opts
);
2613 CATCH (ex
, RETURN_MASK_ERROR
)
2615 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2619 printf_filtered (("\n"));
2623 /* This text does not mention convenience functions on purpose.
2624 The user can't create them except via Python, and if Python support
2625 is installed this message will never be printed ($_streq will
2627 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2628 "Convenience variables have "
2629 "names starting with \"$\";\n"
2630 "use \"set\" as in \"set "
2631 "$foo = 5\" to define them.\n"));
2639 value_from_xmethod (xmethod_worker_up
&&worker
)
2643 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2644 v
->lval
= lval_xcallable
;
2645 v
->location
.xm_worker
= worker
.release ();
2651 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2654 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2656 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2657 && method
->lval
== lval_xcallable
&& argc
> 0);
2659 return method
->location
.xm_worker
->get_result_type
2660 (argv
[0], argv
+ 1, argc
- 1);
2663 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2666 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2668 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2669 && method
->lval
== lval_xcallable
&& argc
> 0);
2671 return method
->location
.xm_worker
->invoke (argv
[0], argv
+ 1, argc
- 1);
2674 /* Extract a value as a C number (either long or double).
2675 Knows how to convert fixed values to double, or
2676 floating values to long.
2677 Does not deallocate the value. */
2680 value_as_long (struct value
*val
)
2682 /* This coerces arrays and functions, which is necessary (e.g.
2683 in disassemble_command). It also dereferences references, which
2684 I suspect is the most logical thing to do. */
2685 val
= coerce_array (val
);
2686 return unpack_long (value_type (val
), value_contents (val
));
2689 /* Extract a value as a C pointer. Does not deallocate the value.
2690 Note that val's type may not actually be a pointer; value_as_long
2691 handles all the cases. */
2693 value_as_address (struct value
*val
)
2695 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2697 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2698 whether we want this to be true eventually. */
2700 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2701 non-address (e.g. argument to "signal", "info break", etc.), or
2702 for pointers to char, in which the low bits *are* significant. */
2703 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2706 /* There are several targets (IA-64, PowerPC, and others) which
2707 don't represent pointers to functions as simply the address of
2708 the function's entry point. For example, on the IA-64, a
2709 function pointer points to a two-word descriptor, generated by
2710 the linker, which contains the function's entry point, and the
2711 value the IA-64 "global pointer" register should have --- to
2712 support position-independent code. The linker generates
2713 descriptors only for those functions whose addresses are taken.
2715 On such targets, it's difficult for GDB to convert an arbitrary
2716 function address into a function pointer; it has to either find
2717 an existing descriptor for that function, or call malloc and
2718 build its own. On some targets, it is impossible for GDB to
2719 build a descriptor at all: the descriptor must contain a jump
2720 instruction; data memory cannot be executed; and code memory
2723 Upon entry to this function, if VAL is a value of type `function'
2724 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2725 value_address (val) is the address of the function. This is what
2726 you'll get if you evaluate an expression like `main'. The call
2727 to COERCE_ARRAY below actually does all the usual unary
2728 conversions, which includes converting values of type `function'
2729 to `pointer to function'. This is the challenging conversion
2730 discussed above. Then, `unpack_long' will convert that pointer
2731 back into an address.
2733 So, suppose the user types `disassemble foo' on an architecture
2734 with a strange function pointer representation, on which GDB
2735 cannot build its own descriptors, and suppose further that `foo'
2736 has no linker-built descriptor. The address->pointer conversion
2737 will signal an error and prevent the command from running, even
2738 though the next step would have been to convert the pointer
2739 directly back into the same address.
2741 The following shortcut avoids this whole mess. If VAL is a
2742 function, just return its address directly. */
2743 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2744 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2745 return value_address (val
);
2747 val
= coerce_array (val
);
2749 /* Some architectures (e.g. Harvard), map instruction and data
2750 addresses onto a single large unified address space. For
2751 instance: An architecture may consider a large integer in the
2752 range 0x10000000 .. 0x1000ffff to already represent a data
2753 addresses (hence not need a pointer to address conversion) while
2754 a small integer would still need to be converted integer to
2755 pointer to address. Just assume such architectures handle all
2756 integer conversions in a single function. */
2760 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2761 must admonish GDB hackers to make sure its behavior matches the
2762 compiler's, whenever possible.
2764 In general, I think GDB should evaluate expressions the same way
2765 the compiler does. When the user copies an expression out of
2766 their source code and hands it to a `print' command, they should
2767 get the same value the compiler would have computed. Any
2768 deviation from this rule can cause major confusion and annoyance,
2769 and needs to be justified carefully. In other words, GDB doesn't
2770 really have the freedom to do these conversions in clever and
2773 AndrewC pointed out that users aren't complaining about how GDB
2774 casts integers to pointers; they are complaining that they can't
2775 take an address from a disassembly listing and give it to `x/i'.
2776 This is certainly important.
2778 Adding an architecture method like integer_to_address() certainly
2779 makes it possible for GDB to "get it right" in all circumstances
2780 --- the target has complete control over how things get done, so
2781 people can Do The Right Thing for their target without breaking
2782 anyone else. The standard doesn't specify how integers get
2783 converted to pointers; usually, the ABI doesn't either, but
2784 ABI-specific code is a more reasonable place to handle it. */
2786 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2787 && !TYPE_IS_REFERENCE (value_type (val
))
2788 && gdbarch_integer_to_address_p (gdbarch
))
2789 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2790 value_contents (val
));
2792 return unpack_long (value_type (val
), value_contents (val
));
2796 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2797 as a long, or as a double, assuming the raw data is described
2798 by type TYPE. Knows how to convert different sizes of values
2799 and can convert between fixed and floating point. We don't assume
2800 any alignment for the raw data. Return value is in host byte order.
2802 If you want functions and arrays to be coerced to pointers, and
2803 references to be dereferenced, call value_as_long() instead.
2805 C++: It is assumed that the front-end has taken care of
2806 all matters concerning pointers to members. A pointer
2807 to member which reaches here is considered to be equivalent
2808 to an INT (or some size). After all, it is only an offset. */
2811 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2813 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2814 enum type_code code
= TYPE_CODE (type
);
2815 int len
= TYPE_LENGTH (type
);
2816 int nosign
= TYPE_UNSIGNED (type
);
2820 case TYPE_CODE_TYPEDEF
:
2821 return unpack_long (check_typedef (type
), valaddr
);
2822 case TYPE_CODE_ENUM
:
2823 case TYPE_CODE_FLAGS
:
2824 case TYPE_CODE_BOOL
:
2826 case TYPE_CODE_CHAR
:
2827 case TYPE_CODE_RANGE
:
2828 case TYPE_CODE_MEMBERPTR
:
2830 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2832 return extract_signed_integer (valaddr
, len
, byte_order
);
2835 case TYPE_CODE_DECFLOAT
:
2836 return target_float_to_longest (valaddr
, type
);
2840 case TYPE_CODE_RVALUE_REF
:
2841 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2842 whether we want this to be true eventually. */
2843 return extract_typed_address (valaddr
, type
);
2846 error (_("Value can't be converted to integer."));
2848 return 0; /* Placate lint. */
2851 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2852 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2853 We don't assume any alignment for the raw data. Return value is in
2856 If you want functions and arrays to be coerced to pointers, and
2857 references to be dereferenced, call value_as_address() instead.
2859 C++: It is assumed that the front-end has taken care of
2860 all matters concerning pointers to members. A pointer
2861 to member which reaches here is considered to be equivalent
2862 to an INT (or some size). After all, it is only an offset. */
2865 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2867 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2868 whether we want this to be true eventually. */
2869 return unpack_long (type
, valaddr
);
2873 is_floating_value (struct value
*val
)
2875 struct type
*type
= check_typedef (value_type (val
));
2877 if (is_floating_type (type
))
2879 if (!target_float_is_valid (value_contents (val
), type
))
2880 error (_("Invalid floating value found in program."));
2888 /* Get the value of the FIELDNO'th field (which must be static) of
2892 value_static_field (struct type
*type
, int fieldno
)
2894 struct value
*retval
;
2896 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2898 case FIELD_LOC_KIND_PHYSADDR
:
2899 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2900 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2902 case FIELD_LOC_KIND_PHYSNAME
:
2904 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2905 /* TYPE_FIELD_NAME (type, fieldno); */
2906 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2908 if (sym
.symbol
== NULL
)
2910 /* With some compilers, e.g. HP aCC, static data members are
2911 reported as non-debuggable symbols. */
2912 struct bound_minimal_symbol msym
2913 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2914 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2917 retval
= allocate_optimized_out_value (field_type
);
2919 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2922 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2926 gdb_assert_not_reached ("unexpected field location kind");
2932 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2933 You have to be careful here, since the size of the data area for the value
2934 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2935 than the old enclosing type, you have to allocate more space for the
2939 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2941 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2943 check_type_length_before_alloc (new_encl_type
);
2945 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2948 val
->enclosing_type
= new_encl_type
;
2951 /* Given a value ARG1 (offset by OFFSET bytes)
2952 of a struct or union type ARG_TYPE,
2953 extract and return the value of one of its (non-static) fields.
2954 FIELDNO says which field. */
2957 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2958 int fieldno
, struct type
*arg_type
)
2962 struct gdbarch
*arch
= get_value_arch (arg1
);
2963 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2965 arg_type
= check_typedef (arg_type
);
2966 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2968 /* Call check_typedef on our type to make sure that, if TYPE
2969 is a TYPE_CODE_TYPEDEF, its length is set to the length
2970 of the target type instead of zero. However, we do not
2971 replace the typedef type by the target type, because we want
2972 to keep the typedef in order to be able to print the type
2973 description correctly. */
2974 check_typedef (type
);
2976 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2978 /* Handle packed fields.
2980 Create a new value for the bitfield, with bitpos and bitsize
2981 set. If possible, arrange offset and bitpos so that we can
2982 do a single aligned read of the size of the containing type.
2983 Otherwise, adjust offset to the byte containing the first
2984 bit. Assume that the address, offset, and embedded offset
2985 are sufficiently aligned. */
2987 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2988 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2990 v
= allocate_value_lazy (type
);
2991 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2992 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2993 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2994 v
->bitpos
= bitpos
% container_bitsize
;
2996 v
->bitpos
= bitpos
% 8;
2997 v
->offset
= (value_embedded_offset (arg1
)
2999 + (bitpos
- v
->bitpos
) / 8);
3000 set_value_parent (v
, arg1
);
3001 if (!value_lazy (arg1
))
3002 value_fetch_lazy (v
);
3004 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3006 /* This field is actually a base subobject, so preserve the
3007 entire object's contents for later references to virtual
3011 /* Lazy register values with offsets are not supported. */
3012 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3013 value_fetch_lazy (arg1
);
3015 /* We special case virtual inheritance here because this
3016 requires access to the contents, which we would rather avoid
3017 for references to ordinary fields of unavailable values. */
3018 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3019 boffset
= baseclass_offset (arg_type
, fieldno
,
3020 value_contents (arg1
),
3021 value_embedded_offset (arg1
),
3022 value_address (arg1
),
3025 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3027 if (value_lazy (arg1
))
3028 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3031 v
= allocate_value (value_enclosing_type (arg1
));
3032 value_contents_copy_raw (v
, 0, arg1
, 0,
3033 TYPE_LENGTH (value_enclosing_type (arg1
)));
3036 v
->offset
= value_offset (arg1
);
3037 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3039 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3041 /* Field is a dynamic data member. */
3043 gdb_assert (0 == offset
);
3044 /* We expect an already resolved data location. */
3045 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3046 /* For dynamic data types defer memory allocation
3047 until we actual access the value. */
3048 v
= allocate_value_lazy (type
);
3052 /* Plain old data member */
3053 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3054 / (HOST_CHAR_BIT
* unit_size
));
3056 /* Lazy register values with offsets are not supported. */
3057 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3058 value_fetch_lazy (arg1
);
3060 if (value_lazy (arg1
))
3061 v
= allocate_value_lazy (type
);
3064 v
= allocate_value (type
);
3065 value_contents_copy_raw (v
, value_embedded_offset (v
),
3066 arg1
, value_embedded_offset (arg1
) + offset
,
3067 type_length_units (type
));
3069 v
->offset
= (value_offset (arg1
) + offset
3070 + value_embedded_offset (arg1
));
3072 set_value_component_location (v
, arg1
);
3076 /* Given a value ARG1 of a struct or union type,
3077 extract and return the value of one of its (non-static) fields.
3078 FIELDNO says which field. */
3081 value_field (struct value
*arg1
, int fieldno
)
3083 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3086 /* Return a non-virtual function as a value.
3087 F is the list of member functions which contains the desired method.
3088 J is an index into F which provides the desired method.
3090 We only use the symbol for its address, so be happy with either a
3091 full symbol or a minimal symbol. */
3094 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3095 int j
, struct type
*type
,
3099 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3100 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3102 struct bound_minimal_symbol msym
;
3104 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3107 memset (&msym
, 0, sizeof (msym
));
3111 gdb_assert (sym
== NULL
);
3112 msym
= lookup_bound_minimal_symbol (physname
);
3113 if (msym
.minsym
== NULL
)
3117 v
= allocate_value (ftype
);
3118 VALUE_LVAL (v
) = lval_memory
;
3121 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3125 /* The minimal symbol might point to a function descriptor;
3126 resolve it to the actual code address instead. */
3127 struct objfile
*objfile
= msym
.objfile
;
3128 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3130 set_value_address (v
,
3131 gdbarch_convert_from_func_ptr_addr
3132 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3137 if (type
!= value_type (*arg1p
))
3138 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3139 value_addr (*arg1p
)));
3141 /* Move the `this' pointer according to the offset.
3142 VALUE_OFFSET (*arg1p) += offset; */
3150 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3151 VALADDR, and store the result in *RESULT.
3152 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3153 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3155 Extracting bits depends on endianness of the machine. Compute the
3156 number of least significant bits to discard. For big endian machines,
3157 we compute the total number of bits in the anonymous object, subtract
3158 off the bit count from the MSB of the object to the MSB of the
3159 bitfield, then the size of the bitfield, which leaves the LSB discard
3160 count. For little endian machines, the discard count is simply the
3161 number of bits from the LSB of the anonymous object to the LSB of the
3164 If the field is signed, we also do sign extension. */
3167 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3168 LONGEST bitpos
, LONGEST bitsize
)
3170 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3175 LONGEST read_offset
;
3177 /* Read the minimum number of bytes required; there may not be
3178 enough bytes to read an entire ULONGEST. */
3179 field_type
= check_typedef (field_type
);
3181 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3184 bytes_read
= TYPE_LENGTH (field_type
);
3185 bitsize
= 8 * bytes_read
;
3188 read_offset
= bitpos
/ 8;
3190 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3191 bytes_read
, byte_order
);
3193 /* Extract bits. See comment above. */
3195 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3196 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3198 lsbcount
= (bitpos
% 8);
3201 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3202 If the field is signed, and is negative, then sign extend. */
3204 if (bitsize
< 8 * (int) sizeof (val
))
3206 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3208 if (!TYPE_UNSIGNED (field_type
))
3210 if (val
& (valmask
^ (valmask
>> 1)))
3220 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3221 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3222 ORIGINAL_VALUE, which must not be NULL. See
3223 unpack_value_bits_as_long for more details. */
3226 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3227 LONGEST embedded_offset
, int fieldno
,
3228 const struct value
*val
, LONGEST
*result
)
3230 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3231 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3232 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3235 gdb_assert (val
!= NULL
);
3237 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3238 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3239 || !value_bits_available (val
, bit_offset
, bitsize
))
3242 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3247 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3248 object at VALADDR. See unpack_bits_as_long for more details. */
3251 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3253 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3254 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3255 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3257 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3260 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3261 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3262 the contents in DEST_VAL, zero or sign extending if the type of
3263 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3264 VAL. If the VAL's contents required to extract the bitfield from
3265 are unavailable/optimized out, DEST_VAL is correspondingly
3266 marked unavailable/optimized out. */
3269 unpack_value_bitfield (struct value
*dest_val
,
3270 LONGEST bitpos
, LONGEST bitsize
,
3271 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3272 const struct value
*val
)
3274 enum bfd_endian byte_order
;
3277 struct type
*field_type
= value_type (dest_val
);
3279 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3281 /* First, unpack and sign extend the bitfield as if it was wholly
3282 valid. Optimized out/unavailable bits are read as zero, but
3283 that's OK, as they'll end up marked below. If the VAL is
3284 wholly-invalid we may have skipped allocating its contents,
3285 though. See allocate_optimized_out_value. */
3286 if (valaddr
!= NULL
)
3290 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3292 store_signed_integer (value_contents_raw (dest_val
),
3293 TYPE_LENGTH (field_type
), byte_order
, num
);
3296 /* Now copy the optimized out / unavailability ranges to the right
3298 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3299 if (byte_order
== BFD_ENDIAN_BIG
)
3300 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3303 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3304 val
, src_bit_offset
, bitsize
);
3307 /* Return a new value with type TYPE, which is FIELDNO field of the
3308 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3309 of VAL. If the VAL's contents required to extract the bitfield
3310 from are unavailable/optimized out, the new value is
3311 correspondingly marked unavailable/optimized out. */
3314 value_field_bitfield (struct type
*type
, int fieldno
,
3315 const gdb_byte
*valaddr
,
3316 LONGEST embedded_offset
, const struct value
*val
)
3318 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3319 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3320 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3322 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3323 valaddr
, embedded_offset
, val
);
3328 /* Modify the value of a bitfield. ADDR points to a block of memory in
3329 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3330 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3331 indicate which bits (in target bit order) comprise the bitfield.
3332 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3333 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3336 modify_field (struct type
*type
, gdb_byte
*addr
,
3337 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3339 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3341 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3344 /* Normalize BITPOS. */
3348 /* If a negative fieldval fits in the field in question, chop
3349 off the sign extension bits. */
3350 if ((~fieldval
& ~(mask
>> 1)) == 0)
3353 /* Warn if value is too big to fit in the field in question. */
3354 if (0 != (fieldval
& ~mask
))
3356 /* FIXME: would like to include fieldval in the message, but
3357 we don't have a sprintf_longest. */
3358 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3360 /* Truncate it, otherwise adjoining fields may be corrupted. */
3364 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3365 false valgrind reports. */
3367 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3368 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3370 /* Shifting for bit field depends on endianness of the target machine. */
3371 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3372 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3374 oword
&= ~(mask
<< bitpos
);
3375 oword
|= fieldval
<< bitpos
;
3377 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3380 /* Pack NUM into BUF using a target format of TYPE. */
3383 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3385 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3388 type
= check_typedef (type
);
3389 len
= TYPE_LENGTH (type
);
3391 switch (TYPE_CODE (type
))
3394 case TYPE_CODE_CHAR
:
3395 case TYPE_CODE_ENUM
:
3396 case TYPE_CODE_FLAGS
:
3397 case TYPE_CODE_BOOL
:
3398 case TYPE_CODE_RANGE
:
3399 case TYPE_CODE_MEMBERPTR
:
3400 store_signed_integer (buf
, len
, byte_order
, num
);
3404 case TYPE_CODE_RVALUE_REF
:
3406 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3410 case TYPE_CODE_DECFLOAT
:
3411 target_float_from_longest (buf
, type
, num
);
3415 error (_("Unexpected type (%d) encountered for integer constant."),
3421 /* Pack NUM into BUF using a target format of TYPE. */
3424 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3427 enum bfd_endian byte_order
;
3429 type
= check_typedef (type
);
3430 len
= TYPE_LENGTH (type
);
3431 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3433 switch (TYPE_CODE (type
))
3436 case TYPE_CODE_CHAR
:
3437 case TYPE_CODE_ENUM
:
3438 case TYPE_CODE_FLAGS
:
3439 case TYPE_CODE_BOOL
:
3440 case TYPE_CODE_RANGE
:
3441 case TYPE_CODE_MEMBERPTR
:
3442 store_unsigned_integer (buf
, len
, byte_order
, num
);
3446 case TYPE_CODE_RVALUE_REF
:
3448 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3452 case TYPE_CODE_DECFLOAT
:
3453 target_float_from_ulongest (buf
, type
, num
);
3457 error (_("Unexpected type (%d) encountered "
3458 "for unsigned integer constant."),
3464 /* Convert C numbers into newly allocated values. */
3467 value_from_longest (struct type
*type
, LONGEST num
)
3469 struct value
*val
= allocate_value (type
);
3471 pack_long (value_contents_raw (val
), type
, num
);
3476 /* Convert C unsigned numbers into newly allocated values. */
3479 value_from_ulongest (struct type
*type
, ULONGEST num
)
3481 struct value
*val
= allocate_value (type
);
3483 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3489 /* Create a value representing a pointer of type TYPE to the address
3493 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3495 struct value
*val
= allocate_value (type
);
3497 store_typed_address (value_contents_raw (val
),
3498 check_typedef (type
), addr
);
3503 /* Create a value of type TYPE whose contents come from VALADDR, if it
3504 is non-null, and whose memory address (in the inferior) is
3505 ADDRESS. The type of the created value may differ from the passed
3506 type TYPE. Make sure to retrieve values new type after this call.
3507 Note that TYPE is not passed through resolve_dynamic_type; this is
3508 a special API intended for use only by Ada. */
3511 value_from_contents_and_address_unresolved (struct type
*type
,
3512 const gdb_byte
*valaddr
,
3517 if (valaddr
== NULL
)
3518 v
= allocate_value_lazy (type
);
3520 v
= value_from_contents (type
, valaddr
);
3521 VALUE_LVAL (v
) = lval_memory
;
3522 set_value_address (v
, address
);
3526 /* Create a value of type TYPE whose contents come from VALADDR, if it
3527 is non-null, and whose memory address (in the inferior) is
3528 ADDRESS. The type of the created value may differ from the passed
3529 type TYPE. Make sure to retrieve values new type after this call. */
3532 value_from_contents_and_address (struct type
*type
,
3533 const gdb_byte
*valaddr
,
3536 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3537 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3540 if (valaddr
== NULL
)
3541 v
= allocate_value_lazy (resolved_type
);
3543 v
= value_from_contents (resolved_type
, valaddr
);
3544 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3545 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3546 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3547 VALUE_LVAL (v
) = lval_memory
;
3548 set_value_address (v
, address
);
3552 /* Create a value of type TYPE holding the contents CONTENTS.
3553 The new value is `not_lval'. */
3556 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3558 struct value
*result
;
3560 result
= allocate_value (type
);
3561 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3565 /* Extract a value from the history file. Input will be of the form
3566 $digits or $$digits. See block comment above 'write_dollar_variable'
3570 value_from_history_ref (const char *h
, const char **endp
)
3582 /* Find length of numeral string. */
3583 for (; isdigit (h
[len
]); len
++)
3586 /* Make sure numeral string is not part of an identifier. */
3587 if (h
[len
] == '_' || isalpha (h
[len
]))
3590 /* Now collect the index value. */
3595 /* For some bizarre reason, "$$" is equivalent to "$$1",
3596 rather than to "$$0" as it ought to be! */
3604 index
= -strtol (&h
[2], &local_end
, 10);
3612 /* "$" is equivalent to "$0". */
3620 index
= strtol (&h
[1], &local_end
, 10);
3625 return access_value_history (index
);
3628 /* Get the component value (offset by OFFSET bytes) of a struct or
3629 union WHOLE. Component's type is TYPE. */
3632 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3636 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3637 v
= allocate_value_lazy (type
);
3640 v
= allocate_value (type
);
3641 value_contents_copy (v
, value_embedded_offset (v
),
3642 whole
, value_embedded_offset (whole
) + offset
,
3643 type_length_units (type
));
3645 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3646 set_value_component_location (v
, whole
);
3652 coerce_ref_if_computed (const struct value
*arg
)
3654 const struct lval_funcs
*funcs
;
3656 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3659 if (value_lval_const (arg
) != lval_computed
)
3662 funcs
= value_computed_funcs (arg
);
3663 if (funcs
->coerce_ref
== NULL
)
3666 return funcs
->coerce_ref (arg
);
3669 /* Look at value.h for description. */
3672 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3673 const struct type
*original_type
,
3674 const struct value
*original_value
)
3676 /* Re-adjust type. */
3677 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3679 /* Add embedding info. */
3680 set_value_enclosing_type (value
, enc_type
);
3681 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3683 /* We may be pointing to an object of some derived type. */
3684 return value_full_object (value
, NULL
, 0, 0, 0);
3688 coerce_ref (struct value
*arg
)
3690 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3691 struct value
*retval
;
3692 struct type
*enc_type
;
3694 retval
= coerce_ref_if_computed (arg
);
3698 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3701 enc_type
= check_typedef (value_enclosing_type (arg
));
3702 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3704 retval
= value_at_lazy (enc_type
,
3705 unpack_pointer (value_type (arg
),
3706 value_contents (arg
)));
3707 enc_type
= value_type (retval
);
3708 return readjust_indirect_value_type (retval
, enc_type
,
3709 value_type_arg_tmp
, arg
);
3713 coerce_array (struct value
*arg
)
3717 arg
= coerce_ref (arg
);
3718 type
= check_typedef (value_type (arg
));
3720 switch (TYPE_CODE (type
))
3722 case TYPE_CODE_ARRAY
:
3723 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3724 arg
= value_coerce_array (arg
);
3726 case TYPE_CODE_FUNC
:
3727 arg
= value_coerce_function (arg
);
3734 /* Return the return value convention that will be used for the
3737 enum return_value_convention
3738 struct_return_convention (struct gdbarch
*gdbarch
,
3739 struct value
*function
, struct type
*value_type
)
3741 enum type_code code
= TYPE_CODE (value_type
);
3743 if (code
== TYPE_CODE_ERROR
)
3744 error (_("Function return type unknown."));
3746 /* Probe the architecture for the return-value convention. */
3747 return gdbarch_return_value (gdbarch
, function
, value_type
,
3751 /* Return true if the function returning the specified type is using
3752 the convention of returning structures in memory (passing in the
3753 address as a hidden first parameter). */
3756 using_struct_return (struct gdbarch
*gdbarch
,
3757 struct value
*function
, struct type
*value_type
)
3759 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3760 /* A void return value is never in memory. See also corresponding
3761 code in "print_return_value". */
3764 return (struct_return_convention (gdbarch
, function
, value_type
)
3765 != RETURN_VALUE_REGISTER_CONVENTION
);
3768 /* Set the initialized field in a value struct. */
3771 set_value_initialized (struct value
*val
, int status
)
3773 val
->initialized
= status
;
3776 /* Return the initialized field in a value struct. */
3779 value_initialized (const struct value
*val
)
3781 return val
->initialized
;
3784 /* Load the actual content of a lazy value. Fetch the data from the
3785 user's process and clear the lazy flag to indicate that the data in
3786 the buffer is valid.
3788 If the value is zero-length, we avoid calling read_memory, which
3789 would abort. We mark the value as fetched anyway -- all 0 bytes of
3793 value_fetch_lazy (struct value
*val
)
3795 gdb_assert (value_lazy (val
));
3796 allocate_value_contents (val
);
3797 /* A value is either lazy, or fully fetched. The
3798 availability/validity is only established as we try to fetch a
3800 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3801 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3802 if (value_bitsize (val
))
3804 /* To read a lazy bitfield, read the entire enclosing value. This
3805 prevents reading the same block of (possibly volatile) memory once
3806 per bitfield. It would be even better to read only the containing
3807 word, but we have no way to record that just specific bits of a
3808 value have been fetched. */
3809 struct type
*type
= check_typedef (value_type (val
));
3810 struct value
*parent
= value_parent (val
);
3812 if (value_lazy (parent
))
3813 value_fetch_lazy (parent
);
3815 unpack_value_bitfield (val
,
3816 value_bitpos (val
), value_bitsize (val
),
3817 value_contents_for_printing (parent
),
3818 value_offset (val
), parent
);
3820 else if (VALUE_LVAL (val
) == lval_memory
)
3822 CORE_ADDR addr
= value_address (val
);
3823 struct type
*type
= check_typedef (value_enclosing_type (val
));
3825 if (TYPE_LENGTH (type
))
3826 read_value_memory (val
, 0, value_stack (val
),
3827 addr
, value_contents_all_raw (val
),
3828 type_length_units (type
));
3830 else if (VALUE_LVAL (val
) == lval_register
)
3832 struct frame_info
*next_frame
;
3834 struct type
*type
= check_typedef (value_type (val
));
3835 struct value
*new_val
= val
, *mark
= value_mark ();
3837 /* Offsets are not supported here; lazy register values must
3838 refer to the entire register. */
3839 gdb_assert (value_offset (val
) == 0);
3841 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3843 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3845 next_frame
= frame_find_by_id (next_frame_id
);
3846 regnum
= VALUE_REGNUM (new_val
);
3848 gdb_assert (next_frame
!= NULL
);
3850 /* Convertible register routines are used for multi-register
3851 values and for interpretation in different types
3852 (e.g. float or int from a double register). Lazy
3853 register values should have the register's natural type,
3854 so they do not apply. */
3855 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3858 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3859 Since a "->next" operation was performed when setting
3860 this field, we do not need to perform a "next" operation
3861 again when unwinding the register. That's why
3862 frame_unwind_register_value() is called here instead of
3863 get_frame_register_value(). */
3864 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3866 /* If we get another lazy lval_register value, it means the
3867 register is found by reading it from NEXT_FRAME's next frame.
3868 frame_unwind_register_value should never return a value with
3869 the frame id pointing to NEXT_FRAME. If it does, it means we
3870 either have two consecutive frames with the same frame id
3871 in the frame chain, or some code is trying to unwind
3872 behind get_prev_frame's back (e.g., a frame unwind
3873 sniffer trying to unwind), bypassing its validations. In
3874 any case, it should always be an internal error to end up
3875 in this situation. */
3876 if (VALUE_LVAL (new_val
) == lval_register
3877 && value_lazy (new_val
)
3878 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3879 internal_error (__FILE__
, __LINE__
,
3880 _("infinite loop while fetching a register"));
3883 /* If it's still lazy (for instance, a saved register on the
3884 stack), fetch it. */
3885 if (value_lazy (new_val
))
3886 value_fetch_lazy (new_val
);
3888 /* Copy the contents and the unavailability/optimized-out
3889 meta-data from NEW_VAL to VAL. */
3890 set_value_lazy (val
, 0);
3891 value_contents_copy (val
, value_embedded_offset (val
),
3892 new_val
, value_embedded_offset (new_val
),
3893 type_length_units (type
));
3897 struct gdbarch
*gdbarch
;
3898 struct frame_info
*frame
;
3899 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3900 so that the frame level will be shown correctly. */
3901 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3902 regnum
= VALUE_REGNUM (val
);
3903 gdbarch
= get_frame_arch (frame
);
3905 fprintf_unfiltered (gdb_stdlog
,
3906 "{ value_fetch_lazy "
3907 "(frame=%d,regnum=%d(%s),...) ",
3908 frame_relative_level (frame
), regnum
,
3909 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3911 fprintf_unfiltered (gdb_stdlog
, "->");
3912 if (value_optimized_out (new_val
))
3914 fprintf_unfiltered (gdb_stdlog
, " ");
3915 val_print_optimized_out (new_val
, gdb_stdlog
);
3920 const gdb_byte
*buf
= value_contents (new_val
);
3922 if (VALUE_LVAL (new_val
) == lval_register
)
3923 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3924 VALUE_REGNUM (new_val
));
3925 else if (VALUE_LVAL (new_val
) == lval_memory
)
3926 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3928 value_address (new_val
)));
3930 fprintf_unfiltered (gdb_stdlog
, " computed");
3932 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3933 fprintf_unfiltered (gdb_stdlog
, "[");
3934 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3935 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3936 fprintf_unfiltered (gdb_stdlog
, "]");
3939 fprintf_unfiltered (gdb_stdlog
, " }\n");
3942 /* Dispose of the intermediate values. This prevents
3943 watchpoints from trying to watch the saved frame pointer. */
3944 value_free_to_mark (mark
);
3946 else if (VALUE_LVAL (val
) == lval_computed
3947 && value_computed_funcs (val
)->read
!= NULL
)
3948 value_computed_funcs (val
)->read (val
);
3950 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3952 set_value_lazy (val
, 0);
3955 /* Implementation of the convenience function $_isvoid. */
3957 static struct value
*
3958 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3959 const struct language_defn
*language
,
3960 void *cookie
, int argc
, struct value
**argv
)
3965 error (_("You must provide one argument for $_isvoid."));
3967 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3969 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3973 _initialize_values (void)
3975 add_cmd ("convenience", no_class
, show_convenience
, _("\
3976 Debugger convenience (\"$foo\") variables and functions.\n\
3977 Convenience variables are created when you assign them values;\n\
3978 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3980 A few convenience variables are given values automatically:\n\
3981 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3982 \"$__\" holds the contents of the last address examined with \"x\"."
3985 Convenience functions are defined via the Python API."
3988 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3990 add_cmd ("values", no_set_class
, show_values
, _("\
3991 Elements of value history around item number IDX (or last ten)."),
3994 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3995 Initialize a convenience variable if necessary.\n\
3996 init-if-undefined VARIABLE = EXPRESSION\n\
3997 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3998 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3999 VARIABLE is already initialized."));
4001 add_prefix_cmd ("function", no_class
, function_command
, _("\
4002 Placeholder command for showing help on convenience functions."),
4003 &functionlist
, "function ", 0, &cmdlist
);
4005 add_internal_function ("_isvoid", _("\
4006 Check whether an expression is void.\n\
4007 Usage: $_isvoid (expression)\n\
4008 Return 1 if the expression is void, zero otherwise."),
4009 isvoid_internal_fn
, NULL
);
4011 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4012 class_support
, &max_value_size
, _("\
4013 Set maximum sized value gdb will load from the inferior."), _("\
4014 Show maximum sized value gdb will load from the inferior."), _("\
4015 Use this to control the maximum size, in bytes, of a value that gdb\n\
4016 will load from the inferior. Setting this value to 'unlimited'\n\
4017 disables checking.\n\
4018 Setting this does not invalidate already allocated values, it only\n\
4019 prevents future values, larger than this size, from being allocated."),
4021 show_max_value_size
,
4022 &setlist
, &showlist
);