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
885 by print commands during this session. Each chunk
886 records 60 consecutive values. The first chunk on
887 the chain records the most recent values.
888 The total number of values is in value_history_count. */
890 #define VALUE_HISTORY_CHUNK 60
892 struct value_history_chunk
894 struct value_history_chunk
*next
;
895 struct value
*values
[VALUE_HISTORY_CHUNK
];
898 /* Chain of chunks now in use. */
900 static struct value_history_chunk
*value_history_chain
;
902 static int value_history_count
; /* Abs number of last entry stored. */
905 /* List of all value objects currently allocated
906 (except for those released by calls to release_value)
907 This is so they can be freed after each command. */
909 static struct value
*all_values
;
911 /* Allocate a lazy value for type TYPE. Its actual content is
912 "lazily" allocated too: the content field of the return value is
913 NULL; it will be allocated when it is fetched from the target. */
916 allocate_value_lazy (struct type
*type
)
920 /* Call check_typedef on our type to make sure that, if TYPE
921 is a TYPE_CODE_TYPEDEF, its length is set to the length
922 of the target type instead of zero. However, we do not
923 replace the typedef type by the target type, because we want
924 to keep the typedef in order to be able to set the VAL's type
925 description correctly. */
926 check_typedef (type
);
928 val
= XCNEW (struct value
);
929 val
->contents
= NULL
;
930 val
->next
= all_values
;
933 val
->enclosing_type
= type
;
934 VALUE_LVAL (val
) = not_lval
;
935 val
->location
.address
= 0;
940 val
->embedded_offset
= 0;
941 val
->pointed_to_offset
= 0;
943 val
->initialized
= 1; /* Default to initialized. */
945 /* Values start out on the all_values chain. */
946 val
->reference_count
= 1;
951 /* The maximum size, in bytes, that GDB will try to allocate for a value.
952 The initial value of 64k was not selected for any specific reason, it is
953 just a reasonable starting point. */
955 static int max_value_size
= 65536; /* 64k bytes */
957 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
958 LONGEST, otherwise GDB will not be able to parse integer values from the
959 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
960 be unable to parse "set max-value-size 2".
962 As we want a consistent GDB experience across hosts with different sizes
963 of LONGEST, this arbitrary minimum value was selected, so long as this
964 is bigger than LONGEST on all GDB supported hosts we're fine. */
966 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
967 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
969 /* Implement the "set max-value-size" command. */
972 set_max_value_size (const char *args
, int from_tty
,
973 struct cmd_list_element
*c
)
975 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
977 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
979 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
980 error (_("max-value-size set too low, increasing to %d bytes"),
985 /* Implement the "show max-value-size" command. */
988 show_max_value_size (struct ui_file
*file
, int from_tty
,
989 struct cmd_list_element
*c
, const char *value
)
991 if (max_value_size
== -1)
992 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
994 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
998 /* Called before we attempt to allocate or reallocate a buffer for the
999 contents of a value. TYPE is the type of the value for which we are
1000 allocating the buffer. If the buffer is too large (based on the user
1001 controllable setting) then throw an error. If this function returns
1002 then we should attempt to allocate the buffer. */
1005 check_type_length_before_alloc (const struct type
*type
)
1007 unsigned int length
= TYPE_LENGTH (type
);
1009 if (max_value_size
> -1 && length
> max_value_size
)
1011 if (TYPE_NAME (type
) != NULL
)
1012 error (_("value of type `%s' requires %u bytes, which is more "
1013 "than max-value-size"), TYPE_NAME (type
), length
);
1015 error (_("value requires %u bytes, which is more than "
1016 "max-value-size"), length
);
1020 /* Allocate the contents of VAL if it has not been allocated yet. */
1023 allocate_value_contents (struct value
*val
)
1027 check_type_length_before_alloc (val
->enclosing_type
);
1029 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1033 /* Allocate a value and its contents for type TYPE. */
1036 allocate_value (struct type
*type
)
1038 struct value
*val
= allocate_value_lazy (type
);
1040 allocate_value_contents (val
);
1045 /* Allocate a value that has the correct length
1046 for COUNT repetitions of type TYPE. */
1049 allocate_repeat_value (struct type
*type
, int count
)
1051 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1052 /* FIXME-type-allocation: need a way to free this type when we are
1054 struct type
*array_type
1055 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1057 return allocate_value (array_type
);
1061 allocate_computed_value (struct type
*type
,
1062 const struct lval_funcs
*funcs
,
1065 struct value
*v
= allocate_value_lazy (type
);
1067 VALUE_LVAL (v
) = lval_computed
;
1068 v
->location
.computed
.funcs
= funcs
;
1069 v
->location
.computed
.closure
= closure
;
1074 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1077 allocate_optimized_out_value (struct type
*type
)
1079 struct value
*retval
= allocate_value_lazy (type
);
1081 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1082 set_value_lazy (retval
, 0);
1086 /* Accessor methods. */
1089 value_next (const struct value
*value
)
1095 value_type (const struct value
*value
)
1100 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1106 value_offset (const struct value
*value
)
1108 return value
->offset
;
1111 set_value_offset (struct value
*value
, LONGEST offset
)
1113 value
->offset
= offset
;
1117 value_bitpos (const struct value
*value
)
1119 return value
->bitpos
;
1122 set_value_bitpos (struct value
*value
, LONGEST bit
)
1124 value
->bitpos
= bit
;
1128 value_bitsize (const struct value
*value
)
1130 return value
->bitsize
;
1133 set_value_bitsize (struct value
*value
, LONGEST bit
)
1135 value
->bitsize
= bit
;
1139 value_parent (const struct value
*value
)
1141 return value
->parent
;
1147 set_value_parent (struct value
*value
, struct value
*parent
)
1149 struct value
*old
= value
->parent
;
1151 value
->parent
= parent
;
1153 value_incref (parent
);
1158 value_contents_raw (struct value
*value
)
1160 struct gdbarch
*arch
= get_value_arch (value
);
1161 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1163 allocate_value_contents (value
);
1164 return value
->contents
+ value
->embedded_offset
* unit_size
;
1168 value_contents_all_raw (struct value
*value
)
1170 allocate_value_contents (value
);
1171 return value
->contents
;
1175 value_enclosing_type (const struct value
*value
)
1177 return value
->enclosing_type
;
1180 /* Look at value.h for description. */
1183 value_actual_type (struct value
*value
, int resolve_simple_types
,
1184 int *real_type_found
)
1186 struct value_print_options opts
;
1187 struct type
*result
;
1189 get_user_print_options (&opts
);
1191 if (real_type_found
)
1192 *real_type_found
= 0;
1193 result
= value_type (value
);
1194 if (opts
.objectprint
)
1196 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1197 fetch its rtti type. */
1198 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1199 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1201 && !value_optimized_out (value
))
1203 struct type
*real_type
;
1205 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1208 if (real_type_found
)
1209 *real_type_found
= 1;
1213 else if (resolve_simple_types
)
1215 if (real_type_found
)
1216 *real_type_found
= 1;
1217 result
= value_enclosing_type (value
);
1225 error_value_optimized_out (void)
1227 error (_("value has been optimized out"));
1231 require_not_optimized_out (const struct value
*value
)
1233 if (!VEC_empty (range_s
, value
->optimized_out
))
1235 if (value
->lval
== lval_register
)
1236 error (_("register has not been saved in frame"));
1238 error_value_optimized_out ();
1243 require_available (const struct value
*value
)
1245 if (!VEC_empty (range_s
, value
->unavailable
))
1246 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1250 value_contents_for_printing (struct value
*value
)
1253 value_fetch_lazy (value
);
1254 return value
->contents
;
1258 value_contents_for_printing_const (const struct value
*value
)
1260 gdb_assert (!value
->lazy
);
1261 return value
->contents
;
1265 value_contents_all (struct value
*value
)
1267 const gdb_byte
*result
= value_contents_for_printing (value
);
1268 require_not_optimized_out (value
);
1269 require_available (value
);
1273 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1274 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1277 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1278 VEC (range_s
) *src_range
, int src_bit_offset
,
1284 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1288 l
= std::max (r
->offset
, (LONGEST
) src_bit_offset
);
1289 h
= std::min (r
->offset
+ r
->length
,
1290 (LONGEST
) src_bit_offset
+ bit_length
);
1293 insert_into_bit_range_vector (dst_range
,
1294 dst_bit_offset
+ (l
- src_bit_offset
),
1299 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1300 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1303 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1304 const struct value
*src
, int src_bit_offset
,
1307 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1308 src
->unavailable
, src_bit_offset
,
1310 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1311 src
->optimized_out
, src_bit_offset
,
1315 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1316 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1317 contents, starting at DST_OFFSET. If unavailable contents are
1318 being copied from SRC, the corresponding DST contents are marked
1319 unavailable accordingly. Neither DST nor SRC may be lazy
1322 It is assumed the contents of DST in the [DST_OFFSET,
1323 DST_OFFSET+LENGTH) range are wholly available. */
1326 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1327 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1329 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1330 struct gdbarch
*arch
= get_value_arch (src
);
1331 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1333 /* A lazy DST would make that this copy operation useless, since as
1334 soon as DST's contents were un-lazied (by a later value_contents
1335 call, say), the contents would be overwritten. A lazy SRC would
1336 mean we'd be copying garbage. */
1337 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1339 /* The overwritten DST range gets unavailability ORed in, not
1340 replaced. Make sure to remember to implement replacing if it
1341 turns out actually necessary. */
1342 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1343 gdb_assert (!value_bits_any_optimized_out (dst
,
1344 TARGET_CHAR_BIT
* dst_offset
,
1345 TARGET_CHAR_BIT
* length
));
1347 /* Copy the data. */
1348 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1349 value_contents_all_raw (src
) + src_offset
* unit_size
,
1350 length
* unit_size
);
1352 /* Copy the meta-data, adjusted. */
1353 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1354 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1355 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1357 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1358 src
, src_bit_offset
,
1362 /* Copy LENGTH bytes of SRC value's (all) contents
1363 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1364 (all) contents, starting at DST_OFFSET. If unavailable contents
1365 are being copied from SRC, the corresponding DST contents are
1366 marked unavailable accordingly. DST must not be lazy. If SRC is
1367 lazy, it will be fetched now.
1369 It is assumed the contents of DST in the [DST_OFFSET,
1370 DST_OFFSET+LENGTH) range are wholly available. */
1373 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1374 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1377 value_fetch_lazy (src
);
1379 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1383 value_lazy (const struct value
*value
)
1389 set_value_lazy (struct value
*value
, int val
)
1395 value_stack (const struct value
*value
)
1397 return value
->stack
;
1401 set_value_stack (struct value
*value
, int val
)
1407 value_contents (struct value
*value
)
1409 const gdb_byte
*result
= value_contents_writeable (value
);
1410 require_not_optimized_out (value
);
1411 require_available (value
);
1416 value_contents_writeable (struct value
*value
)
1419 value_fetch_lazy (value
);
1420 return value_contents_raw (value
);
1424 value_optimized_out (struct value
*value
)
1426 /* We can only know if a value is optimized out once we have tried to
1428 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1432 value_fetch_lazy (value
);
1434 CATCH (ex
, RETURN_MASK_ERROR
)
1436 /* Fall back to checking value->optimized_out. */
1441 return !VEC_empty (range_s
, value
->optimized_out
);
1444 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1445 the following LENGTH bytes. */
1448 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1450 mark_value_bits_optimized_out (value
,
1451 offset
* TARGET_CHAR_BIT
,
1452 length
* TARGET_CHAR_BIT
);
1458 mark_value_bits_optimized_out (struct value
*value
,
1459 LONGEST offset
, LONGEST length
)
1461 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1465 value_bits_synthetic_pointer (const struct value
*value
,
1466 LONGEST offset
, LONGEST length
)
1468 if (value
->lval
!= lval_computed
1469 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1471 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1477 value_embedded_offset (const struct value
*value
)
1479 return value
->embedded_offset
;
1483 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1485 value
->embedded_offset
= val
;
1489 value_pointed_to_offset (const struct value
*value
)
1491 return value
->pointed_to_offset
;
1495 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1497 value
->pointed_to_offset
= val
;
1500 const struct lval_funcs
*
1501 value_computed_funcs (const struct value
*v
)
1503 gdb_assert (value_lval_const (v
) == lval_computed
);
1505 return v
->location
.computed
.funcs
;
1509 value_computed_closure (const struct value
*v
)
1511 gdb_assert (v
->lval
== lval_computed
);
1513 return v
->location
.computed
.closure
;
1517 deprecated_value_lval_hack (struct value
*value
)
1519 return &value
->lval
;
1523 value_lval_const (const struct value
*value
)
1529 value_address (const struct value
*value
)
1531 if (value
->lval
!= lval_memory
)
1533 if (value
->parent
!= NULL
)
1534 return value_address (value
->parent
) + value
->offset
;
1535 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1537 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1538 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1541 return value
->location
.address
+ value
->offset
;
1545 value_raw_address (const struct value
*value
)
1547 if (value
->lval
!= lval_memory
)
1549 return value
->location
.address
;
1553 set_value_address (struct value
*value
, CORE_ADDR addr
)
1555 gdb_assert (value
->lval
== lval_memory
);
1556 value
->location
.address
= addr
;
1559 struct internalvar
**
1560 deprecated_value_internalvar_hack (struct value
*value
)
1562 return &value
->location
.internalvar
;
1566 deprecated_value_next_frame_id_hack (struct value
*value
)
1568 gdb_assert (value
->lval
== lval_register
);
1569 return &value
->location
.reg
.next_frame_id
;
1573 deprecated_value_regnum_hack (struct value
*value
)
1575 gdb_assert (value
->lval
== lval_register
);
1576 return &value
->location
.reg
.regnum
;
1580 deprecated_value_modifiable (const struct value
*value
)
1582 return value
->modifiable
;
1585 /* Return a mark in the value chain. All values allocated after the
1586 mark is obtained (except for those released) are subject to being freed
1587 if a subsequent value_free_to_mark is passed the mark. */
1594 /* Take a reference to VAL. VAL will not be deallocated until all
1595 references are released. */
1598 value_incref (struct value
*val
)
1600 val
->reference_count
++;
1604 /* Release a reference to VAL, which was acquired with value_incref.
1605 This function is also called to deallocate values from the value
1609 value_decref (struct value
*val
)
1613 gdb_assert (val
->reference_count
> 0);
1614 val
->reference_count
--;
1615 if (val
->reference_count
> 0)
1618 /* If there's an associated parent value, drop our reference to
1620 if (val
->parent
!= NULL
)
1621 value_decref (val
->parent
);
1623 if (VALUE_LVAL (val
) == lval_computed
)
1625 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1627 if (funcs
->free_closure
)
1628 funcs
->free_closure (val
);
1630 else if (VALUE_LVAL (val
) == lval_xcallable
)
1631 delete val
->location
.xm_worker
;
1633 xfree (val
->contents
);
1634 VEC_free (range_s
, val
->unavailable
);
1639 /* Free all values allocated since MARK was obtained by value_mark
1640 (except for those released). */
1642 value_free_to_mark (const struct value
*mark
)
1647 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1656 /* Free all the values that have been allocated (except for those released).
1657 Call after each command, successful or not.
1658 In practice this is called before each command, which is sufficient. */
1661 free_all_values (void)
1666 for (val
= all_values
; val
; val
= next
)
1676 /* Frees all the elements in a chain of values. */
1679 free_value_chain (struct value
*v
)
1685 next
= value_next (v
);
1690 /* Remove VAL from the chain all_values
1691 so it will not be freed automatically. */
1694 release_value (struct value
*val
)
1697 bool released
= false;
1699 if (all_values
== val
)
1701 all_values
= val
->next
;
1707 for (v
= all_values
; v
; v
= v
->next
)
1711 v
->next
= val
->next
;
1721 /* We must always return an owned reference. Normally this
1722 happens because we transfer the reference from the value
1723 chain, but in this case the value was not on the chain. */
1727 return value_ref_ptr (val
);
1730 /* Release all values up to mark */
1732 value_release_to_mark (const struct value
*mark
)
1737 for (val
= next
= all_values
; next
; next
= next
->next
)
1739 if (next
->next
== mark
)
1741 all_values
= next
->next
;
1751 /* Return a copy of the value ARG.
1752 It contains the same contents, for same memory address,
1753 but it's a different block of storage. */
1756 value_copy (struct value
*arg
)
1758 struct type
*encl_type
= value_enclosing_type (arg
);
1761 if (value_lazy (arg
))
1762 val
= allocate_value_lazy (encl_type
);
1764 val
= allocate_value (encl_type
);
1765 val
->type
= arg
->type
;
1766 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1767 val
->location
= arg
->location
;
1768 val
->offset
= arg
->offset
;
1769 val
->bitpos
= arg
->bitpos
;
1770 val
->bitsize
= arg
->bitsize
;
1771 val
->lazy
= arg
->lazy
;
1772 val
->embedded_offset
= value_embedded_offset (arg
);
1773 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1774 val
->modifiable
= arg
->modifiable
;
1775 if (!value_lazy (val
))
1777 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1778 TYPE_LENGTH (value_enclosing_type (arg
)));
1781 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1782 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1783 set_value_parent (val
, arg
->parent
);
1784 if (VALUE_LVAL (val
) == lval_computed
)
1786 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1788 if (funcs
->copy_closure
)
1789 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1794 /* Return a "const" and/or "volatile" qualified version of the value V.
1795 If CNST is true, then the returned value will be qualified with
1797 if VOLTL is true, then the returned value will be qualified with
1801 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1803 struct type
*val_type
= value_type (v
);
1804 struct type
*enclosing_type
= value_enclosing_type (v
);
1805 struct value
*cv_val
= value_copy (v
);
1807 deprecated_set_value_type (cv_val
,
1808 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1809 set_value_enclosing_type (cv_val
,
1810 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1815 /* Return a version of ARG that is non-lvalue. */
1818 value_non_lval (struct value
*arg
)
1820 if (VALUE_LVAL (arg
) != not_lval
)
1822 struct type
*enc_type
= value_enclosing_type (arg
);
1823 struct value
*val
= allocate_value (enc_type
);
1825 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1826 TYPE_LENGTH (enc_type
));
1827 val
->type
= arg
->type
;
1828 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1829 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1835 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1838 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1840 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1842 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1843 v
->lval
= lval_memory
;
1844 v
->location
.address
= addr
;
1848 set_value_component_location (struct value
*component
,
1849 const struct value
*whole
)
1853 gdb_assert (whole
->lval
!= lval_xcallable
);
1855 if (whole
->lval
== lval_internalvar
)
1856 VALUE_LVAL (component
) = lval_internalvar_component
;
1858 VALUE_LVAL (component
) = whole
->lval
;
1860 component
->location
= whole
->location
;
1861 if (whole
->lval
== lval_computed
)
1863 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1865 if (funcs
->copy_closure
)
1866 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1869 /* If type has a dynamic resolved location property
1870 update it's value address. */
1871 type
= value_type (whole
);
1872 if (NULL
!= TYPE_DATA_LOCATION (type
)
1873 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1874 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1877 /* Access to the value history. */
1879 /* Record a new value in the value history.
1880 Returns the absolute history index of the entry. */
1883 record_latest_value (struct value
*val
)
1887 /* We don't want this value to have anything to do with the inferior anymore.
1888 In particular, "set $1 = 50" should not affect the variable from which
1889 the value was taken, and fast watchpoints should be able to assume that
1890 a value on the value history never changes. */
1891 if (value_lazy (val
))
1892 value_fetch_lazy (val
);
1893 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1894 from. This is a bit dubious, because then *&$1 does not just return $1
1895 but the current contents of that location. c'est la vie... */
1896 val
->modifiable
= 0;
1898 /* Here we treat value_history_count as origin-zero
1899 and applying to the value being stored now. */
1901 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1904 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1906 newobj
->next
= value_history_chain
;
1907 value_history_chain
= newobj
;
1910 value_history_chain
->values
[i
] = release_value (val
).release ();
1912 /* Now we regard value_history_count as origin-one
1913 and applying to the value just stored. */
1915 return ++value_history_count
;
1918 /* Return a copy of the value in the history with sequence number NUM. */
1921 access_value_history (int num
)
1923 struct value_history_chunk
*chunk
;
1928 absnum
+= value_history_count
;
1933 error (_("The history is empty."));
1935 error (_("There is only one value in the history."));
1937 error (_("History does not go back to $$%d."), -num
);
1939 if (absnum
> value_history_count
)
1940 error (_("History has not yet reached $%d."), absnum
);
1944 /* Now absnum is always absolute and origin zero. */
1946 chunk
= value_history_chain
;
1947 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1948 - absnum
/ VALUE_HISTORY_CHUNK
;
1950 chunk
= chunk
->next
;
1952 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1956 show_values (const char *num_exp
, int from_tty
)
1964 /* "show values +" should print from the stored position.
1965 "show values <exp>" should print around value number <exp>. */
1966 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1967 num
= parse_and_eval_long (num_exp
) - 5;
1971 /* "show values" means print the last 10 values. */
1972 num
= value_history_count
- 9;
1978 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1980 struct value_print_options opts
;
1982 val
= access_value_history (i
);
1983 printf_filtered (("$%d = "), i
);
1984 get_user_print_options (&opts
);
1985 value_print (val
, gdb_stdout
, &opts
);
1986 printf_filtered (("\n"));
1989 /* The next "show values +" should start after what we just printed. */
1992 /* Hitting just return after this command should do the same thing as
1993 "show values +". If num_exp is null, this is unnecessary, since
1994 "show values +" is not useful after "show values". */
1995 if (from_tty
&& num_exp
)
1996 set_repeat_arguments ("+");
1999 enum internalvar_kind
2001 /* The internal variable is empty. */
2004 /* The value of the internal variable is provided directly as
2005 a GDB value object. */
2008 /* A fresh value is computed via a call-back routine on every
2009 access to the internal variable. */
2010 INTERNALVAR_MAKE_VALUE
,
2012 /* The internal variable holds a GDB internal convenience function. */
2013 INTERNALVAR_FUNCTION
,
2015 /* The variable holds an integer value. */
2016 INTERNALVAR_INTEGER
,
2018 /* The variable holds a GDB-provided string. */
2022 union internalvar_data
2024 /* A value object used with INTERNALVAR_VALUE. */
2025 struct value
*value
;
2027 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2030 /* The functions to call. */
2031 const struct internalvar_funcs
*functions
;
2033 /* The function's user-data. */
2037 /* The internal function used with INTERNALVAR_FUNCTION. */
2040 struct internal_function
*function
;
2041 /* True if this is the canonical name for the function. */
2045 /* An integer value used with INTERNALVAR_INTEGER. */
2048 /* If type is non-NULL, it will be used as the type to generate
2049 a value for this internal variable. If type is NULL, a default
2050 integer type for the architecture is used. */
2055 /* A string value used with INTERNALVAR_STRING. */
2059 /* Internal variables. These are variables within the debugger
2060 that hold values assigned by debugger commands.
2061 The user refers to them with a '$' prefix
2062 that does not appear in the variable names stored internally. */
2066 struct internalvar
*next
;
2069 /* We support various different kinds of content of an internal variable.
2070 enum internalvar_kind specifies the kind, and union internalvar_data
2071 provides the data associated with this particular kind. */
2073 enum internalvar_kind kind
;
2075 union internalvar_data u
;
2078 static struct internalvar
*internalvars
;
2080 /* If the variable does not already exist create it and give it the
2081 value given. If no value is given then the default is zero. */
2083 init_if_undefined_command (const char* args
, int from_tty
)
2085 struct internalvar
* intvar
;
2087 /* Parse the expression - this is taken from set_command(). */
2088 expression_up expr
= parse_expression (args
);
2090 /* Validate the expression.
2091 Was the expression an assignment?
2092 Or even an expression at all? */
2093 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2094 error (_("Init-if-undefined requires an assignment expression."));
2096 /* Extract the variable from the parsed expression.
2097 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2098 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2099 error (_("The first parameter to init-if-undefined "
2100 "should be a GDB variable."));
2101 intvar
= expr
->elts
[2].internalvar
;
2103 /* Only evaluate the expression if the lvalue is void.
2104 This may still fail if the expresssion is invalid. */
2105 if (intvar
->kind
== INTERNALVAR_VOID
)
2106 evaluate_expression (expr
.get ());
2110 /* Look up an internal variable with name NAME. NAME should not
2111 normally include a dollar sign.
2113 If the specified internal variable does not exist,
2114 the return value is NULL. */
2116 struct internalvar
*
2117 lookup_only_internalvar (const char *name
)
2119 struct internalvar
*var
;
2121 for (var
= internalvars
; var
; var
= var
->next
)
2122 if (strcmp (var
->name
, name
) == 0)
2128 /* Complete NAME by comparing it to the names of internal
2132 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2134 struct internalvar
*var
;
2137 len
= strlen (name
);
2139 for (var
= internalvars
; var
; var
= var
->next
)
2140 if (strncmp (var
->name
, name
, len
) == 0)
2142 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2144 tracker
.add_completion (std::move (copy
));
2148 /* Create an internal variable with name NAME and with a void value.
2149 NAME should not normally include a dollar sign. */
2151 struct internalvar
*
2152 create_internalvar (const char *name
)
2154 struct internalvar
*var
= XNEW (struct internalvar
);
2156 var
->name
= concat (name
, (char *)NULL
);
2157 var
->kind
= INTERNALVAR_VOID
;
2158 var
->next
= internalvars
;
2163 /* Create an internal variable with name NAME and register FUN as the
2164 function that value_of_internalvar uses to create a value whenever
2165 this variable is referenced. NAME should not normally include a
2166 dollar sign. DATA is passed uninterpreted to FUN when it is
2167 called. CLEANUP, if not NULL, is called when the internal variable
2168 is destroyed. It is passed DATA as its only argument. */
2170 struct internalvar
*
2171 create_internalvar_type_lazy (const char *name
,
2172 const struct internalvar_funcs
*funcs
,
2175 struct internalvar
*var
= create_internalvar (name
);
2177 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2178 var
->u
.make_value
.functions
= funcs
;
2179 var
->u
.make_value
.data
= data
;
2183 /* See documentation in value.h. */
2186 compile_internalvar_to_ax (struct internalvar
*var
,
2187 struct agent_expr
*expr
,
2188 struct axs_value
*value
)
2190 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2191 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2194 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2195 var
->u
.make_value
.data
);
2199 /* Look up an internal variable with name NAME. NAME should not
2200 normally include a dollar sign.
2202 If the specified internal variable does not exist,
2203 one is created, with a void value. */
2205 struct internalvar
*
2206 lookup_internalvar (const char *name
)
2208 struct internalvar
*var
;
2210 var
= lookup_only_internalvar (name
);
2214 return create_internalvar (name
);
2217 /* Return current value of internal variable VAR. For variables that
2218 are not inherently typed, use a value type appropriate for GDBARCH. */
2221 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2224 struct trace_state_variable
*tsv
;
2226 /* If there is a trace state variable of the same name, assume that
2227 is what we really want to see. */
2228 tsv
= find_trace_state_variable (var
->name
);
2231 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2233 if (tsv
->value_known
)
2234 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2237 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2243 case INTERNALVAR_VOID
:
2244 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2247 case INTERNALVAR_FUNCTION
:
2248 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2251 case INTERNALVAR_INTEGER
:
2252 if (!var
->u
.integer
.type
)
2253 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2254 var
->u
.integer
.val
);
2256 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2259 case INTERNALVAR_STRING
:
2260 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2261 builtin_type (gdbarch
)->builtin_char
);
2264 case INTERNALVAR_VALUE
:
2265 val
= value_copy (var
->u
.value
);
2266 if (value_lazy (val
))
2267 value_fetch_lazy (val
);
2270 case INTERNALVAR_MAKE_VALUE
:
2271 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2272 var
->u
.make_value
.data
);
2276 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2279 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2280 on this value go back to affect the original internal variable.
2282 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2283 no underlying modifyable state in the internal variable.
2285 Likewise, if the variable's value is a computed lvalue, we want
2286 references to it to produce another computed lvalue, where
2287 references and assignments actually operate through the
2288 computed value's functions.
2290 This means that internal variables with computed values
2291 behave a little differently from other internal variables:
2292 assignments to them don't just replace the previous value
2293 altogether. At the moment, this seems like the behavior we
2296 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2297 && val
->lval
!= lval_computed
)
2299 VALUE_LVAL (val
) = lval_internalvar
;
2300 VALUE_INTERNALVAR (val
) = var
;
2307 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2309 if (var
->kind
== INTERNALVAR_INTEGER
)
2311 *result
= var
->u
.integer
.val
;
2315 if (var
->kind
== INTERNALVAR_VALUE
)
2317 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2319 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2321 *result
= value_as_long (var
->u
.value
);
2330 get_internalvar_function (struct internalvar
*var
,
2331 struct internal_function
**result
)
2335 case INTERNALVAR_FUNCTION
:
2336 *result
= var
->u
.fn
.function
;
2345 set_internalvar_component (struct internalvar
*var
,
2346 LONGEST offset
, LONGEST bitpos
,
2347 LONGEST bitsize
, struct value
*newval
)
2350 struct gdbarch
*arch
;
2355 case INTERNALVAR_VALUE
:
2356 addr
= value_contents_writeable (var
->u
.value
);
2357 arch
= get_value_arch (var
->u
.value
);
2358 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2361 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2362 value_as_long (newval
), bitpos
, bitsize
);
2364 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2365 TYPE_LENGTH (value_type (newval
)));
2369 /* We can never get a component of any other kind. */
2370 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2375 set_internalvar (struct internalvar
*var
, struct value
*val
)
2377 enum internalvar_kind new_kind
;
2378 union internalvar_data new_data
= { 0 };
2380 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2381 error (_("Cannot overwrite convenience function %s"), var
->name
);
2383 /* Prepare new contents. */
2384 switch (TYPE_CODE (check_typedef (value_type (val
))))
2386 case TYPE_CODE_VOID
:
2387 new_kind
= INTERNALVAR_VOID
;
2390 case TYPE_CODE_INTERNAL_FUNCTION
:
2391 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2392 new_kind
= INTERNALVAR_FUNCTION
;
2393 get_internalvar_function (VALUE_INTERNALVAR (val
),
2394 &new_data
.fn
.function
);
2395 /* Copies created here are never canonical. */
2399 new_kind
= INTERNALVAR_VALUE
;
2400 new_data
.value
= value_copy (val
);
2401 new_data
.value
->modifiable
= 1;
2403 /* Force the value to be fetched from the target now, to avoid problems
2404 later when this internalvar is referenced and the target is gone or
2406 if (value_lazy (new_data
.value
))
2407 value_fetch_lazy (new_data
.value
);
2409 /* Release the value from the value chain to prevent it from being
2410 deleted by free_all_values. From here on this function should not
2411 call error () until new_data is installed into the var->u to avoid
2413 release_value (new_data
.value
).release ();
2415 /* Internal variables which are created from values with a dynamic
2416 location don't need the location property of the origin anymore.
2417 The resolved dynamic location is used prior then any other address
2418 when accessing the value.
2419 If we keep it, we would still refer to the origin value.
2420 Remove the location property in case it exist. */
2421 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2426 /* Clean up old contents. */
2427 clear_internalvar (var
);
2430 var
->kind
= new_kind
;
2432 /* End code which must not call error(). */
2436 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2438 /* Clean up old contents. */
2439 clear_internalvar (var
);
2441 var
->kind
= INTERNALVAR_INTEGER
;
2442 var
->u
.integer
.type
= NULL
;
2443 var
->u
.integer
.val
= l
;
2447 set_internalvar_string (struct internalvar
*var
, const char *string
)
2449 /* Clean up old contents. */
2450 clear_internalvar (var
);
2452 var
->kind
= INTERNALVAR_STRING
;
2453 var
->u
.string
= xstrdup (string
);
2457 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2459 /* Clean up old contents. */
2460 clear_internalvar (var
);
2462 var
->kind
= INTERNALVAR_FUNCTION
;
2463 var
->u
.fn
.function
= f
;
2464 var
->u
.fn
.canonical
= 1;
2465 /* Variables installed here are always the canonical version. */
2469 clear_internalvar (struct internalvar
*var
)
2471 /* Clean up old contents. */
2474 case INTERNALVAR_VALUE
:
2475 value_decref (var
->u
.value
);
2478 case INTERNALVAR_STRING
:
2479 xfree (var
->u
.string
);
2482 case INTERNALVAR_MAKE_VALUE
:
2483 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2484 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2491 /* Reset to void kind. */
2492 var
->kind
= INTERNALVAR_VOID
;
2496 internalvar_name (const struct internalvar
*var
)
2501 static struct internal_function
*
2502 create_internal_function (const char *name
,
2503 internal_function_fn handler
, void *cookie
)
2505 struct internal_function
*ifn
= XNEW (struct internal_function
);
2507 ifn
->name
= xstrdup (name
);
2508 ifn
->handler
= handler
;
2509 ifn
->cookie
= cookie
;
2514 value_internal_function_name (struct value
*val
)
2516 struct internal_function
*ifn
;
2519 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2520 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2521 gdb_assert (result
);
2527 call_internal_function (struct gdbarch
*gdbarch
,
2528 const struct language_defn
*language
,
2529 struct value
*func
, int argc
, struct value
**argv
)
2531 struct internal_function
*ifn
;
2534 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2535 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2536 gdb_assert (result
);
2538 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2541 /* The 'function' command. This does nothing -- it is just a
2542 placeholder to let "help function NAME" work. This is also used as
2543 the implementation of the sub-command that is created when
2544 registering an internal function. */
2546 function_command (const char *command
, int from_tty
)
2551 /* Clean up if an internal function's command is destroyed. */
2553 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2555 xfree ((char *) self
->name
);
2556 xfree ((char *) self
->doc
);
2559 /* Add a new internal function. NAME is the name of the function; DOC
2560 is a documentation string describing the function. HANDLER is
2561 called when the function is invoked. COOKIE is an arbitrary
2562 pointer which is passed to HANDLER and is intended for "user
2565 add_internal_function (const char *name
, const char *doc
,
2566 internal_function_fn handler
, void *cookie
)
2568 struct cmd_list_element
*cmd
;
2569 struct internal_function
*ifn
;
2570 struct internalvar
*var
= lookup_internalvar (name
);
2572 ifn
= create_internal_function (name
, handler
, cookie
);
2573 set_internalvar_function (var
, ifn
);
2575 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2577 cmd
->destroyer
= function_destroyer
;
2580 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2581 prevent cycles / duplicates. */
2584 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2585 htab_t copied_types
)
2587 if (TYPE_OBJFILE (value
->type
) == objfile
)
2588 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2590 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2591 value
->enclosing_type
= copy_type_recursive (objfile
,
2592 value
->enclosing_type
,
2596 /* Likewise for internal variable VAR. */
2599 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2600 htab_t copied_types
)
2604 case INTERNALVAR_INTEGER
:
2605 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2607 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2610 case INTERNALVAR_VALUE
:
2611 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2616 /* Update the internal variables and value history when OBJFILE is
2617 discarded; we must copy the types out of the objfile. New global types
2618 will be created for every convenience variable which currently points to
2619 this objfile's types, and the convenience variables will be adjusted to
2620 use the new global types. */
2623 preserve_values (struct objfile
*objfile
)
2625 htab_t copied_types
;
2626 struct value_history_chunk
*cur
;
2627 struct internalvar
*var
;
2630 /* Create the hash table. We allocate on the objfile's obstack, since
2631 it is soon to be deleted. */
2632 copied_types
= create_copied_types_hash (objfile
);
2634 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2635 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2637 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2639 for (var
= internalvars
; var
; var
= var
->next
)
2640 preserve_one_internalvar (var
, objfile
, copied_types
);
2642 preserve_ext_lang_values (objfile
, copied_types
);
2644 htab_delete (copied_types
);
2648 show_convenience (const char *ignore
, int from_tty
)
2650 struct gdbarch
*gdbarch
= get_current_arch ();
2651 struct internalvar
*var
;
2653 struct value_print_options opts
;
2655 get_user_print_options (&opts
);
2656 for (var
= internalvars
; var
; var
= var
->next
)
2663 printf_filtered (("$%s = "), var
->name
);
2669 val
= value_of_internalvar (gdbarch
, var
);
2670 value_print (val
, gdb_stdout
, &opts
);
2672 CATCH (ex
, RETURN_MASK_ERROR
)
2674 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2678 printf_filtered (("\n"));
2682 /* This text does not mention convenience functions on purpose.
2683 The user can't create them except via Python, and if Python support
2684 is installed this message will never be printed ($_streq will
2686 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2687 "Convenience variables have "
2688 "names starting with \"$\";\n"
2689 "use \"set\" as in \"set "
2690 "$foo = 5\" to define them.\n"));
2698 value_from_xmethod (xmethod_worker_up
&&worker
)
2702 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2703 v
->lval
= lval_xcallable
;
2704 v
->location
.xm_worker
= worker
.release ();
2710 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2713 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2715 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2716 && method
->lval
== lval_xcallable
&& argc
> 0);
2718 return method
->location
.xm_worker
->get_result_type
2719 (argv
[0], argv
+ 1, argc
- 1);
2722 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2725 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2727 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2728 && method
->lval
== lval_xcallable
&& argc
> 0);
2730 return method
->location
.xm_worker
->invoke (argv
[0], argv
+ 1, argc
- 1);
2733 /* Extract a value as a C number (either long or double).
2734 Knows how to convert fixed values to double, or
2735 floating values to long.
2736 Does not deallocate the value. */
2739 value_as_long (struct value
*val
)
2741 /* This coerces arrays and functions, which is necessary (e.g.
2742 in disassemble_command). It also dereferences references, which
2743 I suspect is the most logical thing to do. */
2744 val
= coerce_array (val
);
2745 return unpack_long (value_type (val
), value_contents (val
));
2748 /* Extract a value as a C pointer. Does not deallocate the value.
2749 Note that val's type may not actually be a pointer; value_as_long
2750 handles all the cases. */
2752 value_as_address (struct value
*val
)
2754 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2756 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2757 whether we want this to be true eventually. */
2759 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2760 non-address (e.g. argument to "signal", "info break", etc.), or
2761 for pointers to char, in which the low bits *are* significant. */
2762 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2765 /* There are several targets (IA-64, PowerPC, and others) which
2766 don't represent pointers to functions as simply the address of
2767 the function's entry point. For example, on the IA-64, a
2768 function pointer points to a two-word descriptor, generated by
2769 the linker, which contains the function's entry point, and the
2770 value the IA-64 "global pointer" register should have --- to
2771 support position-independent code. The linker generates
2772 descriptors only for those functions whose addresses are taken.
2774 On such targets, it's difficult for GDB to convert an arbitrary
2775 function address into a function pointer; it has to either find
2776 an existing descriptor for that function, or call malloc and
2777 build its own. On some targets, it is impossible for GDB to
2778 build a descriptor at all: the descriptor must contain a jump
2779 instruction; data memory cannot be executed; and code memory
2782 Upon entry to this function, if VAL is a value of type `function'
2783 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2784 value_address (val) is the address of the function. This is what
2785 you'll get if you evaluate an expression like `main'. The call
2786 to COERCE_ARRAY below actually does all the usual unary
2787 conversions, which includes converting values of type `function'
2788 to `pointer to function'. This is the challenging conversion
2789 discussed above. Then, `unpack_long' will convert that pointer
2790 back into an address.
2792 So, suppose the user types `disassemble foo' on an architecture
2793 with a strange function pointer representation, on which GDB
2794 cannot build its own descriptors, and suppose further that `foo'
2795 has no linker-built descriptor. The address->pointer conversion
2796 will signal an error and prevent the command from running, even
2797 though the next step would have been to convert the pointer
2798 directly back into the same address.
2800 The following shortcut avoids this whole mess. If VAL is a
2801 function, just return its address directly. */
2802 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2803 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2804 return value_address (val
);
2806 val
= coerce_array (val
);
2808 /* Some architectures (e.g. Harvard), map instruction and data
2809 addresses onto a single large unified address space. For
2810 instance: An architecture may consider a large integer in the
2811 range 0x10000000 .. 0x1000ffff to already represent a data
2812 addresses (hence not need a pointer to address conversion) while
2813 a small integer would still need to be converted integer to
2814 pointer to address. Just assume such architectures handle all
2815 integer conversions in a single function. */
2819 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2820 must admonish GDB hackers to make sure its behavior matches the
2821 compiler's, whenever possible.
2823 In general, I think GDB should evaluate expressions the same way
2824 the compiler does. When the user copies an expression out of
2825 their source code and hands it to a `print' command, they should
2826 get the same value the compiler would have computed. Any
2827 deviation from this rule can cause major confusion and annoyance,
2828 and needs to be justified carefully. In other words, GDB doesn't
2829 really have the freedom to do these conversions in clever and
2832 AndrewC pointed out that users aren't complaining about how GDB
2833 casts integers to pointers; they are complaining that they can't
2834 take an address from a disassembly listing and give it to `x/i'.
2835 This is certainly important.
2837 Adding an architecture method like integer_to_address() certainly
2838 makes it possible for GDB to "get it right" in all circumstances
2839 --- the target has complete control over how things get done, so
2840 people can Do The Right Thing for their target without breaking
2841 anyone else. The standard doesn't specify how integers get
2842 converted to pointers; usually, the ABI doesn't either, but
2843 ABI-specific code is a more reasonable place to handle it. */
2845 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2846 && !TYPE_IS_REFERENCE (value_type (val
))
2847 && gdbarch_integer_to_address_p (gdbarch
))
2848 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2849 value_contents (val
));
2851 return unpack_long (value_type (val
), value_contents (val
));
2855 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2856 as a long, or as a double, assuming the raw data is described
2857 by type TYPE. Knows how to convert different sizes of values
2858 and can convert between fixed and floating point. We don't assume
2859 any alignment for the raw data. Return value is in host byte order.
2861 If you want functions and arrays to be coerced to pointers, and
2862 references to be dereferenced, call value_as_long() instead.
2864 C++: It is assumed that the front-end has taken care of
2865 all matters concerning pointers to members. A pointer
2866 to member which reaches here is considered to be equivalent
2867 to an INT (or some size). After all, it is only an offset. */
2870 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2872 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2873 enum type_code code
= TYPE_CODE (type
);
2874 int len
= TYPE_LENGTH (type
);
2875 int nosign
= TYPE_UNSIGNED (type
);
2879 case TYPE_CODE_TYPEDEF
:
2880 return unpack_long (check_typedef (type
), valaddr
);
2881 case TYPE_CODE_ENUM
:
2882 case TYPE_CODE_FLAGS
:
2883 case TYPE_CODE_BOOL
:
2885 case TYPE_CODE_CHAR
:
2886 case TYPE_CODE_RANGE
:
2887 case TYPE_CODE_MEMBERPTR
:
2889 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2891 return extract_signed_integer (valaddr
, len
, byte_order
);
2894 case TYPE_CODE_DECFLOAT
:
2895 return target_float_to_longest (valaddr
, type
);
2899 case TYPE_CODE_RVALUE_REF
:
2900 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2901 whether we want this to be true eventually. */
2902 return extract_typed_address (valaddr
, type
);
2905 error (_("Value can't be converted to integer."));
2907 return 0; /* Placate lint. */
2910 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2911 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2912 We don't assume any alignment for the raw data. Return value is in
2915 If you want functions and arrays to be coerced to pointers, and
2916 references to be dereferenced, call value_as_address() instead.
2918 C++: It is assumed that the front-end has taken care of
2919 all matters concerning pointers to members. A pointer
2920 to member which reaches here is considered to be equivalent
2921 to an INT (or some size). After all, it is only an offset. */
2924 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2926 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2927 whether we want this to be true eventually. */
2928 return unpack_long (type
, valaddr
);
2932 is_floating_value (struct value
*val
)
2934 struct type
*type
= check_typedef (value_type (val
));
2936 if (is_floating_type (type
))
2938 if (!target_float_is_valid (value_contents (val
), type
))
2939 error (_("Invalid floating value found in program."));
2947 /* Get the value of the FIELDNO'th field (which must be static) of
2951 value_static_field (struct type
*type
, int fieldno
)
2953 struct value
*retval
;
2955 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2957 case FIELD_LOC_KIND_PHYSADDR
:
2958 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2959 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2961 case FIELD_LOC_KIND_PHYSNAME
:
2963 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2964 /* TYPE_FIELD_NAME (type, fieldno); */
2965 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2967 if (sym
.symbol
== NULL
)
2969 /* With some compilers, e.g. HP aCC, static data members are
2970 reported as non-debuggable symbols. */
2971 struct bound_minimal_symbol msym
2972 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2973 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2976 retval
= allocate_optimized_out_value (field_type
);
2978 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2981 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2985 gdb_assert_not_reached ("unexpected field location kind");
2991 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2992 You have to be careful here, since the size of the data area for the value
2993 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2994 than the old enclosing type, you have to allocate more space for the
2998 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3000 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3002 check_type_length_before_alloc (new_encl_type
);
3004 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3007 val
->enclosing_type
= new_encl_type
;
3010 /* Given a value ARG1 (offset by OFFSET bytes)
3011 of a struct or union type ARG_TYPE,
3012 extract and return the value of one of its (non-static) fields.
3013 FIELDNO says which field. */
3016 value_primitive_field (struct value
*arg1
, LONGEST offset
,
3017 int fieldno
, struct type
*arg_type
)
3021 struct gdbarch
*arch
= get_value_arch (arg1
);
3022 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3024 arg_type
= check_typedef (arg_type
);
3025 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3027 /* Call check_typedef on our type to make sure that, if TYPE
3028 is a TYPE_CODE_TYPEDEF, its length is set to the length
3029 of the target type instead of zero. However, we do not
3030 replace the typedef type by the target type, because we want
3031 to keep the typedef in order to be able to print the type
3032 description correctly. */
3033 check_typedef (type
);
3035 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3037 /* Handle packed fields.
3039 Create a new value for the bitfield, with bitpos and bitsize
3040 set. If possible, arrange offset and bitpos so that we can
3041 do a single aligned read of the size of the containing type.
3042 Otherwise, adjust offset to the byte containing the first
3043 bit. Assume that the address, offset, and embedded offset
3044 are sufficiently aligned. */
3046 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3047 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
3049 v
= allocate_value_lazy (type
);
3050 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3051 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3052 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3053 v
->bitpos
= bitpos
% container_bitsize
;
3055 v
->bitpos
= bitpos
% 8;
3056 v
->offset
= (value_embedded_offset (arg1
)
3058 + (bitpos
- v
->bitpos
) / 8);
3059 set_value_parent (v
, arg1
);
3060 if (!value_lazy (arg1
))
3061 value_fetch_lazy (v
);
3063 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3065 /* This field is actually a base subobject, so preserve the
3066 entire object's contents for later references to virtual
3070 /* Lazy register values with offsets are not supported. */
3071 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3072 value_fetch_lazy (arg1
);
3074 /* We special case virtual inheritance here because this
3075 requires access to the contents, which we would rather avoid
3076 for references to ordinary fields of unavailable values. */
3077 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3078 boffset
= baseclass_offset (arg_type
, fieldno
,
3079 value_contents (arg1
),
3080 value_embedded_offset (arg1
),
3081 value_address (arg1
),
3084 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3086 if (value_lazy (arg1
))
3087 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3090 v
= allocate_value (value_enclosing_type (arg1
));
3091 value_contents_copy_raw (v
, 0, arg1
, 0,
3092 TYPE_LENGTH (value_enclosing_type (arg1
)));
3095 v
->offset
= value_offset (arg1
);
3096 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3098 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3100 /* Field is a dynamic data member. */
3102 gdb_assert (0 == offset
);
3103 /* We expect an already resolved data location. */
3104 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3105 /* For dynamic data types defer memory allocation
3106 until we actual access the value. */
3107 v
= allocate_value_lazy (type
);
3111 /* Plain old data member */
3112 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3113 / (HOST_CHAR_BIT
* unit_size
));
3115 /* Lazy register values with offsets are not supported. */
3116 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3117 value_fetch_lazy (arg1
);
3119 if (value_lazy (arg1
))
3120 v
= allocate_value_lazy (type
);
3123 v
= allocate_value (type
);
3124 value_contents_copy_raw (v
, value_embedded_offset (v
),
3125 arg1
, value_embedded_offset (arg1
) + offset
,
3126 type_length_units (type
));
3128 v
->offset
= (value_offset (arg1
) + offset
3129 + value_embedded_offset (arg1
));
3131 set_value_component_location (v
, arg1
);
3135 /* Given a value ARG1 of a struct or union type,
3136 extract and return the value of one of its (non-static) fields.
3137 FIELDNO says which field. */
3140 value_field (struct value
*arg1
, int fieldno
)
3142 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3145 /* Return a non-virtual function as a value.
3146 F is the list of member functions which contains the desired method.
3147 J is an index into F which provides the desired method.
3149 We only use the symbol for its address, so be happy with either a
3150 full symbol or a minimal symbol. */
3153 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3154 int j
, struct type
*type
,
3158 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3159 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3161 struct bound_minimal_symbol msym
;
3163 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3166 memset (&msym
, 0, sizeof (msym
));
3170 gdb_assert (sym
== NULL
);
3171 msym
= lookup_bound_minimal_symbol (physname
);
3172 if (msym
.minsym
== NULL
)
3176 v
= allocate_value (ftype
);
3177 VALUE_LVAL (v
) = lval_memory
;
3180 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3184 /* The minimal symbol might point to a function descriptor;
3185 resolve it to the actual code address instead. */
3186 struct objfile
*objfile
= msym
.objfile
;
3187 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3189 set_value_address (v
,
3190 gdbarch_convert_from_func_ptr_addr
3191 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3196 if (type
!= value_type (*arg1p
))
3197 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3198 value_addr (*arg1p
)));
3200 /* Move the `this' pointer according to the offset.
3201 VALUE_OFFSET (*arg1p) += offset; */
3209 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3210 VALADDR, and store the result in *RESULT.
3211 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3212 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3214 Extracting bits depends on endianness of the machine. Compute the
3215 number of least significant bits to discard. For big endian machines,
3216 we compute the total number of bits in the anonymous object, subtract
3217 off the bit count from the MSB of the object to the MSB of the
3218 bitfield, then the size of the bitfield, which leaves the LSB discard
3219 count. For little endian machines, the discard count is simply the
3220 number of bits from the LSB of the anonymous object to the LSB of the
3223 If the field is signed, we also do sign extension. */
3226 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3227 LONGEST bitpos
, LONGEST bitsize
)
3229 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3234 LONGEST read_offset
;
3236 /* Read the minimum number of bytes required; there may not be
3237 enough bytes to read an entire ULONGEST. */
3238 field_type
= check_typedef (field_type
);
3240 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3243 bytes_read
= TYPE_LENGTH (field_type
);
3244 bitsize
= 8 * bytes_read
;
3247 read_offset
= bitpos
/ 8;
3249 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3250 bytes_read
, byte_order
);
3252 /* Extract bits. See comment above. */
3254 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3255 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3257 lsbcount
= (bitpos
% 8);
3260 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3261 If the field is signed, and is negative, then sign extend. */
3263 if (bitsize
< 8 * (int) sizeof (val
))
3265 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3267 if (!TYPE_UNSIGNED (field_type
))
3269 if (val
& (valmask
^ (valmask
>> 1)))
3279 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3280 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3281 ORIGINAL_VALUE, which must not be NULL. See
3282 unpack_value_bits_as_long for more details. */
3285 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3286 LONGEST embedded_offset
, int fieldno
,
3287 const struct value
*val
, LONGEST
*result
)
3289 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3290 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3291 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3294 gdb_assert (val
!= NULL
);
3296 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3297 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3298 || !value_bits_available (val
, bit_offset
, bitsize
))
3301 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3306 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3307 object at VALADDR. See unpack_bits_as_long for more details. */
3310 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3312 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3313 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3314 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3316 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3319 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3320 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3321 the contents in DEST_VAL, zero or sign extending if the type of
3322 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3323 VAL. If the VAL's contents required to extract the bitfield from
3324 are unavailable/optimized out, DEST_VAL is correspondingly
3325 marked unavailable/optimized out. */
3328 unpack_value_bitfield (struct value
*dest_val
,
3329 LONGEST bitpos
, LONGEST bitsize
,
3330 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3331 const struct value
*val
)
3333 enum bfd_endian byte_order
;
3336 struct type
*field_type
= value_type (dest_val
);
3338 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3340 /* First, unpack and sign extend the bitfield as if it was wholly
3341 valid. Optimized out/unavailable bits are read as zero, but
3342 that's OK, as they'll end up marked below. If the VAL is
3343 wholly-invalid we may have skipped allocating its contents,
3344 though. See allocate_optimized_out_value. */
3345 if (valaddr
!= NULL
)
3349 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3351 store_signed_integer (value_contents_raw (dest_val
),
3352 TYPE_LENGTH (field_type
), byte_order
, num
);
3355 /* Now copy the optimized out / unavailability ranges to the right
3357 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3358 if (byte_order
== BFD_ENDIAN_BIG
)
3359 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3362 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3363 val
, src_bit_offset
, bitsize
);
3366 /* Return a new value with type TYPE, which is FIELDNO field of the
3367 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3368 of VAL. If the VAL's contents required to extract the bitfield
3369 from are unavailable/optimized out, the new value is
3370 correspondingly marked unavailable/optimized out. */
3373 value_field_bitfield (struct type
*type
, int fieldno
,
3374 const gdb_byte
*valaddr
,
3375 LONGEST embedded_offset
, const struct value
*val
)
3377 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3378 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3379 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3381 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3382 valaddr
, embedded_offset
, val
);
3387 /* Modify the value of a bitfield. ADDR points to a block of memory in
3388 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3389 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3390 indicate which bits (in target bit order) comprise the bitfield.
3391 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3392 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3395 modify_field (struct type
*type
, gdb_byte
*addr
,
3396 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3398 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3400 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3403 /* Normalize BITPOS. */
3407 /* If a negative fieldval fits in the field in question, chop
3408 off the sign extension bits. */
3409 if ((~fieldval
& ~(mask
>> 1)) == 0)
3412 /* Warn if value is too big to fit in the field in question. */
3413 if (0 != (fieldval
& ~mask
))
3415 /* FIXME: would like to include fieldval in the message, but
3416 we don't have a sprintf_longest. */
3417 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3419 /* Truncate it, otherwise adjoining fields may be corrupted. */
3423 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3424 false valgrind reports. */
3426 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3427 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3429 /* Shifting for bit field depends on endianness of the target machine. */
3430 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3431 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3433 oword
&= ~(mask
<< bitpos
);
3434 oword
|= fieldval
<< bitpos
;
3436 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3439 /* Pack NUM into BUF using a target format of TYPE. */
3442 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3444 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3447 type
= check_typedef (type
);
3448 len
= TYPE_LENGTH (type
);
3450 switch (TYPE_CODE (type
))
3453 case TYPE_CODE_CHAR
:
3454 case TYPE_CODE_ENUM
:
3455 case TYPE_CODE_FLAGS
:
3456 case TYPE_CODE_BOOL
:
3457 case TYPE_CODE_RANGE
:
3458 case TYPE_CODE_MEMBERPTR
:
3459 store_signed_integer (buf
, len
, byte_order
, num
);
3463 case TYPE_CODE_RVALUE_REF
:
3465 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3469 case TYPE_CODE_DECFLOAT
:
3470 target_float_from_longest (buf
, type
, num
);
3474 error (_("Unexpected type (%d) encountered for integer constant."),
3480 /* Pack NUM into BUF using a target format of TYPE. */
3483 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3486 enum bfd_endian byte_order
;
3488 type
= check_typedef (type
);
3489 len
= TYPE_LENGTH (type
);
3490 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3492 switch (TYPE_CODE (type
))
3495 case TYPE_CODE_CHAR
:
3496 case TYPE_CODE_ENUM
:
3497 case TYPE_CODE_FLAGS
:
3498 case TYPE_CODE_BOOL
:
3499 case TYPE_CODE_RANGE
:
3500 case TYPE_CODE_MEMBERPTR
:
3501 store_unsigned_integer (buf
, len
, byte_order
, num
);
3505 case TYPE_CODE_RVALUE_REF
:
3507 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3511 case TYPE_CODE_DECFLOAT
:
3512 target_float_from_ulongest (buf
, type
, num
);
3516 error (_("Unexpected type (%d) encountered "
3517 "for unsigned integer constant."),
3523 /* Convert C numbers into newly allocated values. */
3526 value_from_longest (struct type
*type
, LONGEST num
)
3528 struct value
*val
= allocate_value (type
);
3530 pack_long (value_contents_raw (val
), type
, num
);
3535 /* Convert C unsigned numbers into newly allocated values. */
3538 value_from_ulongest (struct type
*type
, ULONGEST num
)
3540 struct value
*val
= allocate_value (type
);
3542 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3548 /* Create a value representing a pointer of type TYPE to the address
3552 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3554 struct value
*val
= allocate_value (type
);
3556 store_typed_address (value_contents_raw (val
),
3557 check_typedef (type
), addr
);
3562 /* Create a value of type TYPE whose contents come from VALADDR, if it
3563 is non-null, and whose memory address (in the inferior) is
3564 ADDRESS. The type of the created value may differ from the passed
3565 type TYPE. Make sure to retrieve values new type after this call.
3566 Note that TYPE is not passed through resolve_dynamic_type; this is
3567 a special API intended for use only by Ada. */
3570 value_from_contents_and_address_unresolved (struct type
*type
,
3571 const gdb_byte
*valaddr
,
3576 if (valaddr
== NULL
)
3577 v
= allocate_value_lazy (type
);
3579 v
= value_from_contents (type
, valaddr
);
3580 VALUE_LVAL (v
) = lval_memory
;
3581 set_value_address (v
, address
);
3585 /* Create a value of type TYPE whose contents come from VALADDR, if it
3586 is non-null, and whose memory address (in the inferior) is
3587 ADDRESS. The type of the created value may differ from the passed
3588 type TYPE. Make sure to retrieve values new type after this call. */
3591 value_from_contents_and_address (struct type
*type
,
3592 const gdb_byte
*valaddr
,
3595 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3596 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3599 if (valaddr
== NULL
)
3600 v
= allocate_value_lazy (resolved_type
);
3602 v
= value_from_contents (resolved_type
, valaddr
);
3603 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3604 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3605 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3606 VALUE_LVAL (v
) = lval_memory
;
3607 set_value_address (v
, address
);
3611 /* Create a value of type TYPE holding the contents CONTENTS.
3612 The new value is `not_lval'. */
3615 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3617 struct value
*result
;
3619 result
= allocate_value (type
);
3620 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3624 /* Extract a value from the history file. Input will be of the form
3625 $digits or $$digits. See block comment above 'write_dollar_variable'
3629 value_from_history_ref (const char *h
, const char **endp
)
3641 /* Find length of numeral string. */
3642 for (; isdigit (h
[len
]); len
++)
3645 /* Make sure numeral string is not part of an identifier. */
3646 if (h
[len
] == '_' || isalpha (h
[len
]))
3649 /* Now collect the index value. */
3654 /* For some bizarre reason, "$$" is equivalent to "$$1",
3655 rather than to "$$0" as it ought to be! */
3663 index
= -strtol (&h
[2], &local_end
, 10);
3671 /* "$" is equivalent to "$0". */
3679 index
= strtol (&h
[1], &local_end
, 10);
3684 return access_value_history (index
);
3687 /* Get the component value (offset by OFFSET bytes) of a struct or
3688 union WHOLE. Component's type is TYPE. */
3691 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3695 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3696 v
= allocate_value_lazy (type
);
3699 v
= allocate_value (type
);
3700 value_contents_copy (v
, value_embedded_offset (v
),
3701 whole
, value_embedded_offset (whole
) + offset
,
3702 type_length_units (type
));
3704 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3705 set_value_component_location (v
, whole
);
3711 coerce_ref_if_computed (const struct value
*arg
)
3713 const struct lval_funcs
*funcs
;
3715 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3718 if (value_lval_const (arg
) != lval_computed
)
3721 funcs
= value_computed_funcs (arg
);
3722 if (funcs
->coerce_ref
== NULL
)
3725 return funcs
->coerce_ref (arg
);
3728 /* Look at value.h for description. */
3731 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3732 const struct type
*original_type
,
3733 const struct value
*original_value
)
3735 /* Re-adjust type. */
3736 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3738 /* Add embedding info. */
3739 set_value_enclosing_type (value
, enc_type
);
3740 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3742 /* We may be pointing to an object of some derived type. */
3743 return value_full_object (value
, NULL
, 0, 0, 0);
3747 coerce_ref (struct value
*arg
)
3749 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3750 struct value
*retval
;
3751 struct type
*enc_type
;
3753 retval
= coerce_ref_if_computed (arg
);
3757 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3760 enc_type
= check_typedef (value_enclosing_type (arg
));
3761 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3763 retval
= value_at_lazy (enc_type
,
3764 unpack_pointer (value_type (arg
),
3765 value_contents (arg
)));
3766 enc_type
= value_type (retval
);
3767 return readjust_indirect_value_type (retval
, enc_type
,
3768 value_type_arg_tmp
, arg
);
3772 coerce_array (struct value
*arg
)
3776 arg
= coerce_ref (arg
);
3777 type
= check_typedef (value_type (arg
));
3779 switch (TYPE_CODE (type
))
3781 case TYPE_CODE_ARRAY
:
3782 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3783 arg
= value_coerce_array (arg
);
3785 case TYPE_CODE_FUNC
:
3786 arg
= value_coerce_function (arg
);
3793 /* Return the return value convention that will be used for the
3796 enum return_value_convention
3797 struct_return_convention (struct gdbarch
*gdbarch
,
3798 struct value
*function
, struct type
*value_type
)
3800 enum type_code code
= TYPE_CODE (value_type
);
3802 if (code
== TYPE_CODE_ERROR
)
3803 error (_("Function return type unknown."));
3805 /* Probe the architecture for the return-value convention. */
3806 return gdbarch_return_value (gdbarch
, function
, value_type
,
3810 /* Return true if the function returning the specified type is using
3811 the convention of returning structures in memory (passing in the
3812 address as a hidden first parameter). */
3815 using_struct_return (struct gdbarch
*gdbarch
,
3816 struct value
*function
, struct type
*value_type
)
3818 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3819 /* A void return value is never in memory. See also corresponding
3820 code in "print_return_value". */
3823 return (struct_return_convention (gdbarch
, function
, value_type
)
3824 != RETURN_VALUE_REGISTER_CONVENTION
);
3827 /* Set the initialized field in a value struct. */
3830 set_value_initialized (struct value
*val
, int status
)
3832 val
->initialized
= status
;
3835 /* Return the initialized field in a value struct. */
3838 value_initialized (const struct value
*val
)
3840 return val
->initialized
;
3843 /* Load the actual content of a lazy value. Fetch the data from the
3844 user's process and clear the lazy flag to indicate that the data in
3845 the buffer is valid.
3847 If the value is zero-length, we avoid calling read_memory, which
3848 would abort. We mark the value as fetched anyway -- all 0 bytes of
3852 value_fetch_lazy (struct value
*val
)
3854 gdb_assert (value_lazy (val
));
3855 allocate_value_contents (val
);
3856 /* A value is either lazy, or fully fetched. The
3857 availability/validity is only established as we try to fetch a
3859 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3860 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3861 if (value_bitsize (val
))
3863 /* To read a lazy bitfield, read the entire enclosing value. This
3864 prevents reading the same block of (possibly volatile) memory once
3865 per bitfield. It would be even better to read only the containing
3866 word, but we have no way to record that just specific bits of a
3867 value have been fetched. */
3868 struct type
*type
= check_typedef (value_type (val
));
3869 struct value
*parent
= value_parent (val
);
3871 if (value_lazy (parent
))
3872 value_fetch_lazy (parent
);
3874 unpack_value_bitfield (val
,
3875 value_bitpos (val
), value_bitsize (val
),
3876 value_contents_for_printing (parent
),
3877 value_offset (val
), parent
);
3879 else if (VALUE_LVAL (val
) == lval_memory
)
3881 CORE_ADDR addr
= value_address (val
);
3882 struct type
*type
= check_typedef (value_enclosing_type (val
));
3884 if (TYPE_LENGTH (type
))
3885 read_value_memory (val
, 0, value_stack (val
),
3886 addr
, value_contents_all_raw (val
),
3887 type_length_units (type
));
3889 else if (VALUE_LVAL (val
) == lval_register
)
3891 struct frame_info
*next_frame
;
3893 struct type
*type
= check_typedef (value_type (val
));
3894 struct value
*new_val
= val
, *mark
= value_mark ();
3896 /* Offsets are not supported here; lazy register values must
3897 refer to the entire register. */
3898 gdb_assert (value_offset (val
) == 0);
3900 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3902 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3904 next_frame
= frame_find_by_id (next_frame_id
);
3905 regnum
= VALUE_REGNUM (new_val
);
3907 gdb_assert (next_frame
!= NULL
);
3909 /* Convertible register routines are used for multi-register
3910 values and for interpretation in different types
3911 (e.g. float or int from a double register). Lazy
3912 register values should have the register's natural type,
3913 so they do not apply. */
3914 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3917 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3918 Since a "->next" operation was performed when setting
3919 this field, we do not need to perform a "next" operation
3920 again when unwinding the register. That's why
3921 frame_unwind_register_value() is called here instead of
3922 get_frame_register_value(). */
3923 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3925 /* If we get another lazy lval_register value, it means the
3926 register is found by reading it from NEXT_FRAME's next frame.
3927 frame_unwind_register_value should never return a value with
3928 the frame id pointing to NEXT_FRAME. If it does, it means we
3929 either have two consecutive frames with the same frame id
3930 in the frame chain, or some code is trying to unwind
3931 behind get_prev_frame's back (e.g., a frame unwind
3932 sniffer trying to unwind), bypassing its validations. In
3933 any case, it should always be an internal error to end up
3934 in this situation. */
3935 if (VALUE_LVAL (new_val
) == lval_register
3936 && value_lazy (new_val
)
3937 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3938 internal_error (__FILE__
, __LINE__
,
3939 _("infinite loop while fetching a register"));
3942 /* If it's still lazy (for instance, a saved register on the
3943 stack), fetch it. */
3944 if (value_lazy (new_val
))
3945 value_fetch_lazy (new_val
);
3947 /* Copy the contents and the unavailability/optimized-out
3948 meta-data from NEW_VAL to VAL. */
3949 set_value_lazy (val
, 0);
3950 value_contents_copy (val
, value_embedded_offset (val
),
3951 new_val
, value_embedded_offset (new_val
),
3952 type_length_units (type
));
3956 struct gdbarch
*gdbarch
;
3957 struct frame_info
*frame
;
3958 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3959 so that the frame level will be shown correctly. */
3960 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3961 regnum
= VALUE_REGNUM (val
);
3962 gdbarch
= get_frame_arch (frame
);
3964 fprintf_unfiltered (gdb_stdlog
,
3965 "{ value_fetch_lazy "
3966 "(frame=%d,regnum=%d(%s),...) ",
3967 frame_relative_level (frame
), regnum
,
3968 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3970 fprintf_unfiltered (gdb_stdlog
, "->");
3971 if (value_optimized_out (new_val
))
3973 fprintf_unfiltered (gdb_stdlog
, " ");
3974 val_print_optimized_out (new_val
, gdb_stdlog
);
3979 const gdb_byte
*buf
= value_contents (new_val
);
3981 if (VALUE_LVAL (new_val
) == lval_register
)
3982 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3983 VALUE_REGNUM (new_val
));
3984 else if (VALUE_LVAL (new_val
) == lval_memory
)
3985 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3987 value_address (new_val
)));
3989 fprintf_unfiltered (gdb_stdlog
, " computed");
3991 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3992 fprintf_unfiltered (gdb_stdlog
, "[");
3993 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3994 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3995 fprintf_unfiltered (gdb_stdlog
, "]");
3998 fprintf_unfiltered (gdb_stdlog
, " }\n");
4001 /* Dispose of the intermediate values. This prevents
4002 watchpoints from trying to watch the saved frame pointer. */
4003 value_free_to_mark (mark
);
4005 else if (VALUE_LVAL (val
) == lval_computed
4006 && value_computed_funcs (val
)->read
!= NULL
)
4007 value_computed_funcs (val
)->read (val
);
4009 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4011 set_value_lazy (val
, 0);
4014 /* Implementation of the convenience function $_isvoid. */
4016 static struct value
*
4017 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4018 const struct language_defn
*language
,
4019 void *cookie
, int argc
, struct value
**argv
)
4024 error (_("You must provide one argument for $_isvoid."));
4026 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4028 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4032 _initialize_values (void)
4034 add_cmd ("convenience", no_class
, show_convenience
, _("\
4035 Debugger convenience (\"$foo\") variables and functions.\n\
4036 Convenience variables are created when you assign them values;\n\
4037 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4039 A few convenience variables are given values automatically:\n\
4040 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4041 \"$__\" holds the contents of the last address examined with \"x\"."
4044 Convenience functions are defined via the Python API."
4047 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4049 add_cmd ("values", no_set_class
, show_values
, _("\
4050 Elements of value history around item number IDX (or last ten)."),
4053 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4054 Initialize a convenience variable if necessary.\n\
4055 init-if-undefined VARIABLE = EXPRESSION\n\
4056 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4057 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4058 VARIABLE is already initialized."));
4060 add_prefix_cmd ("function", no_class
, function_command
, _("\
4061 Placeholder command for showing help on convenience functions."),
4062 &functionlist
, "function ", 0, &cmdlist
);
4064 add_internal_function ("_isvoid", _("\
4065 Check whether an expression is void.\n\
4066 Usage: $_isvoid (expression)\n\
4067 Return 1 if the expression is void, zero otherwise."),
4068 isvoid_internal_fn
, NULL
);
4070 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4071 class_support
, &max_value_size
, _("\
4072 Set maximum sized value gdb will load from the inferior."), _("\
4073 Show maximum sized value gdb will load from the inferior."), _("\
4074 Use this to control the maximum size, in bytes, of a value that gdb\n\
4075 will load from the inferior. Setting this value to 'unlimited'\n\
4076 disables checking.\n\
4077 Setting this does not invalidate already allocated values, it only\n\
4078 prevents future values, larger than this size, from being allocated."),
4080 show_max_value_size
,
4081 &setlist
, &showlist
);