1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
37 #include "cli/cli-decode.h"
38 #include "extension.h"
40 #include "tracepoint.h"
42 #include "user-regs.h"
44 /* Prototypes for exported functions. */
46 void _initialize_values (void);
48 /* Definition of a user function. */
49 struct internal_function
51 /* The name of the function. It is a bit odd to have this in the
52 function itself -- the user might use a differently-named
53 convenience variable to hold the function. */
57 internal_function_fn handler
;
59 /* User data for the handler. */
63 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
67 /* Lowest offset in the range. */
70 /* Length of the range. */
74 typedef struct range range_s
;
78 /* Returns true if the ranges defined by [offset1, offset1+len1) and
79 [offset2, offset2+len2) overlap. */
82 ranges_overlap (int offset1
, int len1
,
83 int offset2
, int len2
)
87 l
= max (offset1
, offset2
);
88 h
= min (offset1
+ len1
, offset2
+ len2
);
92 /* Returns true if the first argument is strictly less than the
93 second, useful for VEC_lower_bound. We keep ranges sorted by
94 offset and coalesce overlapping and contiguous ranges, so this just
95 compares the starting offset. */
98 range_lessthan (const range_s
*r1
, const range_s
*r2
)
100 return r1
->offset
< r2
->offset
;
103 /* Returns true if RANGES contains any range that overlaps [OFFSET,
107 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
112 what
.offset
= offset
;
113 what
.length
= length
;
115 /* We keep ranges sorted by offset and coalesce overlapping and
116 contiguous ranges, so to check if a range list contains a given
117 range, we can do a binary search for the position the given range
118 would be inserted if we only considered the starting OFFSET of
119 ranges. We call that position I. Since we also have LENGTH to
120 care for (this is a range afterall), we need to check if the
121 _previous_ range overlaps the I range. E.g.,
125 |---| |---| |------| ... |--|
130 In the case above, the binary search would return `I=1', meaning,
131 this OFFSET should be inserted at position 1, and the current
132 position 1 should be pushed further (and before 2). But, `0'
135 Then we need to check if the I range overlaps the I range itself.
140 |---| |---| |-------| ... |--|
146 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
150 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
152 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
156 if (i
< VEC_length (range_s
, ranges
))
158 struct range
*r
= VEC_index (range_s
, ranges
, i
);
160 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
167 static struct cmd_list_element
*functionlist
;
169 /* Note that the fields in this structure are arranged to save a bit
174 /* Type of value; either not an lval, or one of the various
175 different possible kinds of lval. */
178 /* Is it modifiable? Only relevant if lval != not_lval. */
179 unsigned int modifiable
: 1;
181 /* If zero, contents of this value are in the contents field. If
182 nonzero, contents are in inferior. If the lval field is lval_memory,
183 the contents are in inferior memory at location.address plus offset.
184 The lval field may also be lval_register.
186 WARNING: This field is used by the code which handles watchpoints
187 (see breakpoint.c) to decide whether a particular value can be
188 watched by hardware watchpoints. If the lazy flag is set for
189 some member of a value chain, it is assumed that this member of
190 the chain doesn't need to be watched as part of watching the
191 value itself. This is how GDB avoids watching the entire struct
192 or array when the user wants to watch a single struct member or
193 array element. If you ever change the way lazy flag is set and
194 reset, be sure to consider this use as well! */
195 unsigned int lazy
: 1;
197 /* If value is a variable, is it initialized or not. */
198 unsigned int initialized
: 1;
200 /* If value is from the stack. If this is set, read_stack will be
201 used instead of read_memory to enable extra caching. */
202 unsigned int stack
: 1;
204 /* If the value has been released. */
205 unsigned int released
: 1;
207 /* Register number if the value is from a register. */
210 /* Location of value (if lval). */
213 /* If lval == lval_memory, this is the address in the inferior.
214 If lval == lval_register, this is the byte offset into the
215 registers structure. */
218 /* Pointer to internal variable. */
219 struct internalvar
*internalvar
;
221 /* Pointer to xmethod worker. */
222 struct xmethod_worker
*xm_worker
;
224 /* If lval == lval_computed, this is a set of function pointers
225 to use to access and describe the value, and a closure pointer
229 /* Functions to call. */
230 const struct lval_funcs
*funcs
;
232 /* Closure for those functions to use. */
237 /* Describes offset of a value within lval of a structure in target
238 addressable memory units. If lval == lval_memory, this is an offset to
239 the address. If lval == lval_register, this is a further offset from
240 location.address within the registers structure. Note also the member
241 embedded_offset below. */
244 /* Only used for bitfields; number of bits contained in them. */
247 /* Only used for bitfields; position of start of field. For
248 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
249 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
252 /* The number of references to this value. When a value is created,
253 the value chain holds a reference, so REFERENCE_COUNT is 1. If
254 release_value is called, this value is removed from the chain but
255 the caller of release_value now has a reference to this value.
256 The caller must arrange for a call to value_free later. */
259 /* Only used for bitfields; the containing value. This allows a
260 single read from the target when displaying multiple
262 struct value
*parent
;
264 /* Frame register value is relative to. This will be described in
265 the lval enum above as "lval_register". */
266 struct frame_id frame_id
;
268 /* Type of the value. */
271 /* If a value represents a C++ object, then the `type' field gives
272 the object's compile-time type. If the object actually belongs
273 to some class derived from `type', perhaps with other base
274 classes and additional members, then `type' is just a subobject
275 of the real thing, and the full object is probably larger than
276 `type' would suggest.
278 If `type' is a dynamic class (i.e. one with a vtable), then GDB
279 can actually determine the object's run-time type by looking at
280 the run-time type information in the vtable. When this
281 information is available, we may elect to read in the entire
282 object, for several reasons:
284 - When printing the value, the user would probably rather see the
285 full object, not just the limited portion apparent from the
288 - If `type' has virtual base classes, then even printing `type'
289 alone may require reaching outside the `type' portion of the
290 object to wherever the virtual base class has been stored.
292 When we store the entire object, `enclosing_type' is the run-time
293 type -- the complete object -- and `embedded_offset' is the
294 offset of `type' within that larger type, in target addressable memory
295 units. The value_contents() macro takes `embedded_offset' into account,
296 so most GDB code continues to see the `type' portion of the value, just
297 as the inferior would.
299 If `type' is a pointer to an object, then `enclosing_type' is a
300 pointer to the object's run-time type, and `pointed_to_offset' is
301 the offset in target addressable memory units from the full object
302 to the pointed-to object -- that is, the value `embedded_offset' would
303 have if we followed the pointer and fetched the complete object.
304 (I don't really see the point. Why not just determine the
305 run-time type when you indirect, and avoid the special case? The
306 contents don't matter until you indirect anyway.)
308 If we're not doing anything fancy, `enclosing_type' is equal to
309 `type', and `embedded_offset' is zero, so everything works
311 struct type
*enclosing_type
;
313 int pointed_to_offset
;
315 /* Values are stored in a chain, so that they can be deleted easily
316 over calls to the inferior. Values assigned to internal
317 variables, put into the value history or exposed to Python are
318 taken off this list. */
321 /* Actual contents of the value. Target byte-order. NULL or not
322 valid if lazy is nonzero. */
325 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
326 rather than available, since the common and default case is for a
327 value to be available. This is filled in at value read time.
328 The unavailable ranges are tracked in bits. Note that a contents
329 bit that has been optimized out doesn't really exist in the
330 program, so it can't be marked unavailable either. */
331 VEC(range_s
) *unavailable
;
333 /* Likewise, but for optimized out contents (a chunk of the value of
334 a variable that does not actually exist in the program). If LVAL
335 is lval_register, this is a register ($pc, $sp, etc., never a
336 program variable) that has not been saved in the frame. Not
337 saved registers and optimized-out program variables values are
338 treated pretty much the same, except not-saved registers have a
339 different string representation and related error strings. */
340 VEC(range_s
) *optimized_out
;
346 get_value_arch (const struct value
*value
)
348 return get_type_arch (value_type (value
));
352 value_bits_available (const struct value
*value
, int offset
, int length
)
354 gdb_assert (!value
->lazy
);
356 return !ranges_contain (value
->unavailable
, offset
, length
);
360 value_bytes_available (const struct value
*value
, int offset
, int length
)
362 return value_bits_available (value
,
363 offset
* TARGET_CHAR_BIT
,
364 length
* TARGET_CHAR_BIT
);
368 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
370 gdb_assert (!value
->lazy
);
372 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
376 value_entirely_available (struct value
*value
)
378 /* We can only tell whether the whole value is available when we try
381 value_fetch_lazy (value
);
383 if (VEC_empty (range_s
, value
->unavailable
))
388 /* Returns true if VALUE is entirely covered by RANGES. If the value
389 is lazy, it'll be read now. Note that RANGE is a pointer to
390 pointer because reading the value might change *RANGE. */
393 value_entirely_covered_by_range_vector (struct value
*value
,
394 VEC(range_s
) **ranges
)
396 /* We can only tell whether the whole value is optimized out /
397 unavailable when we try to read it. */
399 value_fetch_lazy (value
);
401 if (VEC_length (range_s
, *ranges
) == 1)
403 struct range
*t
= VEC_index (range_s
, *ranges
, 0);
406 && t
->length
== (TARGET_CHAR_BIT
407 * TYPE_LENGTH (value_enclosing_type (value
))))
415 value_entirely_unavailable (struct value
*value
)
417 return value_entirely_covered_by_range_vector (value
, &value
->unavailable
);
421 value_entirely_optimized_out (struct value
*value
)
423 return value_entirely_covered_by_range_vector (value
, &value
->optimized_out
);
426 /* Insert into the vector pointed to by VECTORP the bit range starting of
427 OFFSET bits, and extending for the next LENGTH bits. */
430 insert_into_bit_range_vector (VEC(range_s
) **vectorp
, int offset
, int length
)
435 /* Insert the range sorted. If there's overlap or the new range
436 would be contiguous with an existing range, merge. */
438 newr
.offset
= offset
;
439 newr
.length
= length
;
441 /* Do a binary search for the position the given range would be
442 inserted if we only considered the starting OFFSET of ranges.
443 Call that position I. Since we also have LENGTH to care for
444 (this is a range afterall), we need to check if the _previous_
445 range overlaps the I range. E.g., calling R the new range:
447 #1 - overlaps with previous
451 |---| |---| |------| ... |--|
456 In the case #1 above, the binary search would return `I=1',
457 meaning, this OFFSET should be inserted at position 1, and the
458 current position 1 should be pushed further (and become 2). But,
459 note that `0' overlaps with R, so we want to merge them.
461 A similar consideration needs to be taken if the new range would
462 be contiguous with the previous range:
464 #2 - contiguous with previous
468 |--| |---| |------| ... |--|
473 If there's no overlap with the previous range, as in:
475 #3 - not overlapping and not contiguous
479 |--| |---| |------| ... |--|
486 #4 - R is the range with lowest offset
490 |--| |---| |------| ... |--|
495 ... we just push the new range to I.
497 All the 4 cases above need to consider that the new range may
498 also overlap several of the ranges that follow, or that R may be
499 contiguous with the following range, and merge. E.g.,
501 #5 - overlapping following ranges
504 |------------------------|
505 |--| |---| |------| ... |--|
514 |--| |---| |------| ... |--|
521 i
= VEC_lower_bound (range_s
, *vectorp
, &newr
, range_lessthan
);
524 struct range
*bef
= VEC_index (range_s
, *vectorp
, i
- 1);
526 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
529 ULONGEST l
= min (bef
->offset
, offset
);
530 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
536 else if (offset
== bef
->offset
+ bef
->length
)
539 bef
->length
+= length
;
545 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
551 VEC_safe_insert (range_s
, *vectorp
, i
, &newr
);
554 /* Check whether the ranges following the one we've just added or
555 touched can be folded in (#5 above). */
556 if (i
+ 1 < VEC_length (range_s
, *vectorp
))
563 /* Get the range we just touched. */
564 t
= VEC_index (range_s
, *vectorp
, i
);
568 for (; VEC_iterate (range_s
, *vectorp
, i
, r
); i
++)
569 if (r
->offset
<= t
->offset
+ t
->length
)
573 l
= min (t
->offset
, r
->offset
);
574 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
583 /* If we couldn't merge this one, we won't be able to
584 merge following ones either, since the ranges are
585 always sorted by OFFSET. */
590 VEC_block_remove (range_s
, *vectorp
, next
, removed
);
595 mark_value_bits_unavailable (struct value
*value
, int offset
, int length
)
597 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
601 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
603 mark_value_bits_unavailable (value
,
604 offset
* TARGET_CHAR_BIT
,
605 length
* TARGET_CHAR_BIT
);
608 /* Find the first range in RANGES that overlaps the range defined by
609 OFFSET and LENGTH, starting at element POS in the RANGES vector,
610 Returns the index into RANGES where such overlapping range was
611 found, or -1 if none was found. */
614 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
615 int offset
, int length
)
620 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
621 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
627 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
628 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
631 It must always be the case that:
632 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
634 It is assumed that memory can be accessed from:
635 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
637 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
638 / TARGET_CHAR_BIT) */
640 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
641 const gdb_byte
*ptr2
, size_t offset2_bits
,
644 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
645 == offset2_bits
% TARGET_CHAR_BIT
);
647 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
650 gdb_byte mask
, b1
, b2
;
652 /* The offset from the base pointers PTR1 and PTR2 is not a complete
653 number of bytes. A number of bits up to either the next exact
654 byte boundary, or LENGTH_BITS (which ever is sooner) will be
656 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
657 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
658 mask
= (1 << bits
) - 1;
660 if (length_bits
< bits
)
662 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
666 /* Now load the two bytes and mask off the bits we care about. */
667 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
668 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
673 /* Now update the length and offsets to take account of the bits
674 we've just compared. */
676 offset1_bits
+= bits
;
677 offset2_bits
+= bits
;
680 if (length_bits
% TARGET_CHAR_BIT
!= 0)
684 gdb_byte mask
, b1
, b2
;
686 /* The length is not an exact number of bytes. After the previous
687 IF.. block then the offsets are byte aligned, or the
688 length is zero (in which case this code is not reached). Compare
689 a number of bits at the end of the region, starting from an exact
691 bits
= length_bits
% TARGET_CHAR_BIT
;
692 o1
= offset1_bits
+ length_bits
- bits
;
693 o2
= offset2_bits
+ length_bits
- bits
;
695 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
696 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
698 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
699 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
701 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
702 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
712 /* We've now taken care of any stray "bits" at the start, or end of
713 the region to compare, the remainder can be covered with a simple
715 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
716 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
717 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
719 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
720 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
721 length_bits
/ TARGET_CHAR_BIT
);
724 /* Length is zero, regions match. */
728 /* Helper struct for find_first_range_overlap_and_match and
729 value_contents_bits_eq. Keep track of which slot of a given ranges
730 vector have we last looked at. */
732 struct ranges_and_idx
735 VEC(range_s
) *ranges
;
737 /* The range we've last found in RANGES. Given ranges are sorted,
738 we can start the next lookup here. */
742 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
743 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
744 ranges starting at OFFSET2 bits. Return true if the ranges match
745 and fill in *L and *H with the overlapping window relative to
746 (both) OFFSET1 or OFFSET2. */
749 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
750 struct ranges_and_idx
*rp2
,
751 int offset1
, int offset2
,
752 int length
, ULONGEST
*l
, ULONGEST
*h
)
754 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
756 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
759 if (rp1
->idx
== -1 && rp2
->idx
== -1)
765 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
773 r1
= VEC_index (range_s
, rp1
->ranges
, rp1
->idx
);
774 r2
= VEC_index (range_s
, rp2
->ranges
, rp2
->idx
);
776 /* Get the unavailable windows intersected by the incoming
777 ranges. The first and last ranges that overlap the argument
778 range may be wider than said incoming arguments ranges. */
779 l1
= max (offset1
, r1
->offset
);
780 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
782 l2
= max (offset2
, r2
->offset
);
783 h2
= min (offset2
+ length
, offset2
+ r2
->length
);
785 /* Make them relative to the respective start offsets, so we can
786 compare them for equality. */
793 /* Different ranges, no match. */
794 if (l1
!= l2
|| h1
!= h2
)
803 /* Helper function for value_contents_eq. The only difference is that
804 this function is bit rather than byte based.
806 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
807 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
808 Return true if the available bits match. */
811 value_contents_bits_eq (const struct value
*val1
, int offset1
,
812 const struct value
*val2
, int offset2
,
815 /* Each array element corresponds to a ranges source (unavailable,
816 optimized out). '1' is for VAL1, '2' for VAL2. */
817 struct ranges_and_idx rp1
[2], rp2
[2];
819 /* See function description in value.h. */
820 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
822 /* We shouldn't be trying to compare past the end of the values. */
823 gdb_assert (offset1
+ length
824 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
825 gdb_assert (offset2
+ length
826 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
828 memset (&rp1
, 0, sizeof (rp1
));
829 memset (&rp2
, 0, sizeof (rp2
));
830 rp1
[0].ranges
= val1
->unavailable
;
831 rp2
[0].ranges
= val2
->unavailable
;
832 rp1
[1].ranges
= val1
->optimized_out
;
833 rp2
[1].ranges
= val2
->optimized_out
;
837 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
840 for (i
= 0; i
< 2; i
++)
842 ULONGEST l_tmp
, h_tmp
;
844 /* The contents only match equal if the invalid/unavailable
845 contents ranges match as well. */
846 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
847 offset1
, offset2
, length
,
851 /* We're interested in the lowest/first range found. */
852 if (i
== 0 || l_tmp
< l
)
859 /* Compare the available/valid contents. */
860 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
861 val2
->contents
, offset2
, l
) != 0)
873 value_contents_eq (const struct value
*val1
, int offset1
,
874 const struct value
*val2
, int offset2
,
877 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
878 val2
, offset2
* TARGET_CHAR_BIT
,
879 length
* TARGET_CHAR_BIT
);
882 /* Prototypes for local functions. */
884 static void show_values (char *, int);
886 static void show_convenience (char *, int);
889 /* The value-history records all the values printed
890 by print commands during this session. Each chunk
891 records 60 consecutive values. The first chunk on
892 the chain records the most recent values.
893 The total number of values is in value_history_count. */
895 #define VALUE_HISTORY_CHUNK 60
897 struct value_history_chunk
899 struct value_history_chunk
*next
;
900 struct value
*values
[VALUE_HISTORY_CHUNK
];
903 /* Chain of chunks now in use. */
905 static struct value_history_chunk
*value_history_chain
;
907 static int value_history_count
; /* Abs number of last entry stored. */
910 /* List of all value objects currently allocated
911 (except for those released by calls to release_value)
912 This is so they can be freed after each command. */
914 static struct value
*all_values
;
916 /* Allocate a lazy value for type TYPE. Its actual content is
917 "lazily" allocated too: the content field of the return value is
918 NULL; it will be allocated when it is fetched from the target. */
921 allocate_value_lazy (struct type
*type
)
925 /* Call check_typedef on our type to make sure that, if TYPE
926 is a TYPE_CODE_TYPEDEF, its length is set to the length
927 of the target type instead of zero. However, we do not
928 replace the typedef type by the target type, because we want
929 to keep the typedef in order to be able to set the VAL's type
930 description correctly. */
931 check_typedef (type
);
933 val
= XCNEW (struct value
);
934 val
->contents
= NULL
;
935 val
->next
= all_values
;
938 val
->enclosing_type
= type
;
939 VALUE_LVAL (val
) = not_lval
;
940 val
->location
.address
= 0;
941 VALUE_FRAME_ID (val
) = null_frame_id
;
945 VALUE_REGNUM (val
) = -1;
947 val
->embedded_offset
= 0;
948 val
->pointed_to_offset
= 0;
950 val
->initialized
= 1; /* Default to initialized. */
952 /* Values start out on the all_values chain. */
953 val
->reference_count
= 1;
958 /* The maximum size, in bytes, that GDB will try to allocate for a value.
959 The initial value of 64k was not selected for any specific reason, it is
960 just a reasonable starting point. */
962 static int max_value_size
= 65536; /* 64k bytes */
964 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
965 LONGEST, otherwise GDB will not be able to parse integer values from the
966 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
967 be unable to parse "set max-value-size 2".
969 As we want a consistent GDB experience across hosts with different sizes
970 of LONGEST, this arbitrary minimum value was selected, so long as this
971 is bigger than LONGEST on all GDB supported hosts we're fine. */
973 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
974 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
976 /* Implement the "set max-value-size" command. */
979 set_max_value_size (char *args
, int from_tty
,
980 struct cmd_list_element
*c
)
982 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
984 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
986 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
987 error (_("max-value-size set too low, increasing to %d bytes"),
992 /* Implement the "show max-value-size" command. */
995 show_max_value_size (struct ui_file
*file
, int from_tty
,
996 struct cmd_list_element
*c
, const char *value
)
998 if (max_value_size
== -1)
999 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
1001 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
1005 /* Called before we attempt to allocate or reallocate a buffer for the
1006 contents of a value. TYPE is the type of the value for which we are
1007 allocating the buffer. If the buffer is too large (based on the user
1008 controllable setting) then throw an error. If this function returns
1009 then we should attempt to allocate the buffer. */
1012 check_type_length_before_alloc (const struct type
*type
)
1014 unsigned int length
= TYPE_LENGTH (type
);
1016 if (max_value_size
> -1 && length
> max_value_size
)
1018 if (TYPE_NAME (type
) != NULL
)
1019 error (_("value of type `%s' requires %u bytes, which is more "
1020 "than max-value-size"), TYPE_NAME (type
), length
);
1022 error (_("value requires %u bytes, which is more than "
1023 "max-value-size"), length
);
1027 /* Allocate the contents of VAL if it has not been allocated yet. */
1030 allocate_value_contents (struct value
*val
)
1034 check_type_length_before_alloc (val
->enclosing_type
);
1036 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1040 /* Allocate a value and its contents for type TYPE. */
1043 allocate_value (struct type
*type
)
1045 struct value
*val
= allocate_value_lazy (type
);
1047 allocate_value_contents (val
);
1052 /* Allocate a value that has the correct length
1053 for COUNT repetitions of type TYPE. */
1056 allocate_repeat_value (struct type
*type
, int count
)
1058 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1059 /* FIXME-type-allocation: need a way to free this type when we are
1061 struct type
*array_type
1062 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1064 return allocate_value (array_type
);
1068 allocate_computed_value (struct type
*type
,
1069 const struct lval_funcs
*funcs
,
1072 struct value
*v
= allocate_value_lazy (type
);
1074 VALUE_LVAL (v
) = lval_computed
;
1075 v
->location
.computed
.funcs
= funcs
;
1076 v
->location
.computed
.closure
= closure
;
1081 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1084 allocate_optimized_out_value (struct type
*type
)
1086 struct value
*retval
= allocate_value_lazy (type
);
1088 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1089 set_value_lazy (retval
, 0);
1093 /* Accessor methods. */
1096 value_next (const struct value
*value
)
1102 value_type (const struct value
*value
)
1107 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1113 value_offset (const struct value
*value
)
1115 return value
->offset
;
1118 set_value_offset (struct value
*value
, int offset
)
1120 value
->offset
= offset
;
1124 value_bitpos (const struct value
*value
)
1126 return value
->bitpos
;
1129 set_value_bitpos (struct value
*value
, int bit
)
1131 value
->bitpos
= bit
;
1135 value_bitsize (const struct value
*value
)
1137 return value
->bitsize
;
1140 set_value_bitsize (struct value
*value
, int bit
)
1142 value
->bitsize
= bit
;
1146 value_parent (const struct value
*value
)
1148 return value
->parent
;
1154 set_value_parent (struct value
*value
, struct value
*parent
)
1156 struct value
*old
= value
->parent
;
1158 value
->parent
= parent
;
1160 value_incref (parent
);
1165 value_contents_raw (struct value
*value
)
1167 struct gdbarch
*arch
= get_value_arch (value
);
1168 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1170 allocate_value_contents (value
);
1171 return value
->contents
+ value
->embedded_offset
* unit_size
;
1175 value_contents_all_raw (struct value
*value
)
1177 allocate_value_contents (value
);
1178 return value
->contents
;
1182 value_enclosing_type (const struct value
*value
)
1184 return value
->enclosing_type
;
1187 /* Look at value.h for description. */
1190 value_actual_type (struct value
*value
, int resolve_simple_types
,
1191 int *real_type_found
)
1193 struct value_print_options opts
;
1194 struct type
*result
;
1196 get_user_print_options (&opts
);
1198 if (real_type_found
)
1199 *real_type_found
= 0;
1200 result
= value_type (value
);
1201 if (opts
.objectprint
)
1203 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1204 fetch its rtti type. */
1205 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1206 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1207 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1209 && !value_optimized_out (value
))
1211 struct type
*real_type
;
1213 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1216 if (real_type_found
)
1217 *real_type_found
= 1;
1221 else if (resolve_simple_types
)
1223 if (real_type_found
)
1224 *real_type_found
= 1;
1225 result
= value_enclosing_type (value
);
1233 error_value_optimized_out (void)
1235 error (_("value has been optimized out"));
1239 require_not_optimized_out (const struct value
*value
)
1241 if (!VEC_empty (range_s
, value
->optimized_out
))
1243 if (value
->lval
== lval_register
)
1244 error (_("register has not been saved in frame"));
1246 error_value_optimized_out ();
1251 require_available (const struct value
*value
)
1253 if (!VEC_empty (range_s
, value
->unavailable
))
1254 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1258 value_contents_for_printing (struct value
*value
)
1261 value_fetch_lazy (value
);
1262 return value
->contents
;
1266 value_contents_for_printing_const (const struct value
*value
)
1268 gdb_assert (!value
->lazy
);
1269 return value
->contents
;
1273 value_contents_all (struct value
*value
)
1275 const gdb_byte
*result
= value_contents_for_printing (value
);
1276 require_not_optimized_out (value
);
1277 require_available (value
);
1281 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1282 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1285 ranges_copy_adjusted (VEC (range_s
) **dst_range
, int dst_bit_offset
,
1286 VEC (range_s
) *src_range
, int src_bit_offset
,
1292 for (i
= 0; VEC_iterate (range_s
, src_range
, i
, r
); i
++)
1296 l
= max (r
->offset
, src_bit_offset
);
1297 h
= min (r
->offset
+ r
->length
, src_bit_offset
+ bit_length
);
1300 insert_into_bit_range_vector (dst_range
,
1301 dst_bit_offset
+ (l
- src_bit_offset
),
1306 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1307 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1310 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1311 const struct value
*src
, int src_bit_offset
,
1314 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1315 src
->unavailable
, src_bit_offset
,
1317 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1318 src
->optimized_out
, src_bit_offset
,
1322 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1323 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1324 contents, starting at DST_OFFSET. If unavailable contents are
1325 being copied from SRC, the corresponding DST contents are marked
1326 unavailable accordingly. Neither DST nor SRC may be lazy
1329 It is assumed the contents of DST in the [DST_OFFSET,
1330 DST_OFFSET+LENGTH) range are wholly available. */
1333 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
1334 struct value
*src
, int src_offset
, int length
)
1337 int src_bit_offset
, dst_bit_offset
, bit_length
;
1338 struct gdbarch
*arch
= get_value_arch (src
);
1339 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1341 /* A lazy DST would make that this copy operation useless, since as
1342 soon as DST's contents were un-lazied (by a later value_contents
1343 call, say), the contents would be overwritten. A lazy SRC would
1344 mean we'd be copying garbage. */
1345 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1347 /* The overwritten DST range gets unavailability ORed in, not
1348 replaced. Make sure to remember to implement replacing if it
1349 turns out actually necessary. */
1350 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1351 gdb_assert (!value_bits_any_optimized_out (dst
,
1352 TARGET_CHAR_BIT
* dst_offset
,
1353 TARGET_CHAR_BIT
* length
));
1355 /* Copy the data. */
1356 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1357 value_contents_all_raw (src
) + src_offset
* unit_size
,
1358 length
* unit_size
);
1360 /* Copy the meta-data, adjusted. */
1361 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1362 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1363 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1365 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1366 src
, src_bit_offset
,
1370 /* Copy LENGTH bytes of SRC value's (all) contents
1371 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1372 (all) contents, starting at DST_OFFSET. If unavailable contents
1373 are being copied from SRC, the corresponding DST contents are
1374 marked unavailable accordingly. DST must not be lazy. If SRC is
1375 lazy, it will be fetched now.
1377 It is assumed the contents of DST in the [DST_OFFSET,
1378 DST_OFFSET+LENGTH) range are wholly available. */
1381 value_contents_copy (struct value
*dst
, int dst_offset
,
1382 struct value
*src
, int src_offset
, int length
)
1385 value_fetch_lazy (src
);
1387 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1391 value_lazy (const struct value
*value
)
1397 set_value_lazy (struct value
*value
, int val
)
1403 value_stack (const struct value
*value
)
1405 return value
->stack
;
1409 set_value_stack (struct value
*value
, int val
)
1415 value_contents (struct value
*value
)
1417 const gdb_byte
*result
= value_contents_writeable (value
);
1418 require_not_optimized_out (value
);
1419 require_available (value
);
1424 value_contents_writeable (struct value
*value
)
1427 value_fetch_lazy (value
);
1428 return value_contents_raw (value
);
1432 value_optimized_out (struct value
*value
)
1434 /* We can only know if a value is optimized out once we have tried to
1436 if (VEC_empty (range_s
, value
->optimized_out
) && value
->lazy
)
1440 value_fetch_lazy (value
);
1442 CATCH (ex
, RETURN_MASK_ERROR
)
1444 /* Fall back to checking value->optimized_out. */
1449 return !VEC_empty (range_s
, value
->optimized_out
);
1452 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1453 the following LENGTH bytes. */
1456 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1458 mark_value_bits_optimized_out (value
,
1459 offset
* TARGET_CHAR_BIT
,
1460 length
* TARGET_CHAR_BIT
);
1466 mark_value_bits_optimized_out (struct value
*value
, int offset
, int length
)
1468 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1472 value_bits_synthetic_pointer (const struct value
*value
,
1473 int offset
, int length
)
1475 if (value
->lval
!= lval_computed
1476 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1478 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1484 value_embedded_offset (const struct value
*value
)
1486 return value
->embedded_offset
;
1490 set_value_embedded_offset (struct value
*value
, int val
)
1492 value
->embedded_offset
= val
;
1496 value_pointed_to_offset (const struct value
*value
)
1498 return value
->pointed_to_offset
;
1502 set_value_pointed_to_offset (struct value
*value
, int val
)
1504 value
->pointed_to_offset
= val
;
1507 const struct lval_funcs
*
1508 value_computed_funcs (const struct value
*v
)
1510 gdb_assert (value_lval_const (v
) == lval_computed
);
1512 return v
->location
.computed
.funcs
;
1516 value_computed_closure (const struct value
*v
)
1518 gdb_assert (v
->lval
== lval_computed
);
1520 return v
->location
.computed
.closure
;
1524 deprecated_value_lval_hack (struct value
*value
)
1526 return &value
->lval
;
1530 value_lval_const (const struct value
*value
)
1536 value_address (const struct value
*value
)
1538 if (value
->lval
== lval_internalvar
1539 || value
->lval
== lval_internalvar_component
1540 || value
->lval
== lval_xcallable
)
1542 if (value
->parent
!= NULL
)
1543 return value_address (value
->parent
) + value
->offset
;
1544 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1546 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1547 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1550 return value
->location
.address
+ value
->offset
;
1554 value_raw_address (const struct value
*value
)
1556 if (value
->lval
== lval_internalvar
1557 || value
->lval
== lval_internalvar_component
1558 || value
->lval
== lval_xcallable
)
1560 return value
->location
.address
;
1564 set_value_address (struct value
*value
, CORE_ADDR addr
)
1566 gdb_assert (value
->lval
!= lval_internalvar
1567 && value
->lval
!= lval_internalvar_component
1568 && value
->lval
!= lval_xcallable
);
1569 value
->location
.address
= addr
;
1572 struct internalvar
**
1573 deprecated_value_internalvar_hack (struct value
*value
)
1575 return &value
->location
.internalvar
;
1579 deprecated_value_frame_id_hack (struct value
*value
)
1581 return &value
->frame_id
;
1585 deprecated_value_regnum_hack (struct value
*value
)
1587 return &value
->regnum
;
1591 deprecated_value_modifiable (const struct value
*value
)
1593 return value
->modifiable
;
1596 /* Return a mark in the value chain. All values allocated after the
1597 mark is obtained (except for those released) are subject to being freed
1598 if a subsequent value_free_to_mark is passed the mark. */
1605 /* Take a reference to VAL. VAL will not be deallocated until all
1606 references are released. */
1609 value_incref (struct value
*val
)
1611 val
->reference_count
++;
1614 /* Release a reference to VAL, which was acquired with value_incref.
1615 This function is also called to deallocate values from the value
1619 value_free (struct value
*val
)
1623 gdb_assert (val
->reference_count
> 0);
1624 val
->reference_count
--;
1625 if (val
->reference_count
> 0)
1628 /* If there's an associated parent value, drop our reference to
1630 if (val
->parent
!= NULL
)
1631 value_free (val
->parent
);
1633 if (VALUE_LVAL (val
) == lval_computed
)
1635 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1637 if (funcs
->free_closure
)
1638 funcs
->free_closure (val
);
1640 else if (VALUE_LVAL (val
) == lval_xcallable
)
1641 free_xmethod_worker (val
->location
.xm_worker
);
1643 xfree (val
->contents
);
1644 VEC_free (range_s
, val
->unavailable
);
1649 /* Free all values allocated since MARK was obtained by value_mark
1650 (except for those released). */
1652 value_free_to_mark (const struct value
*mark
)
1657 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1666 /* Free all the values that have been allocated (except for those released).
1667 Call after each command, successful or not.
1668 In practice this is called before each command, which is sufficient. */
1671 free_all_values (void)
1676 for (val
= all_values
; val
; val
= next
)
1686 /* Frees all the elements in a chain of values. */
1689 free_value_chain (struct value
*v
)
1695 next
= value_next (v
);
1700 /* Remove VAL from the chain all_values
1701 so it will not be freed automatically. */
1704 release_value (struct value
*val
)
1708 if (all_values
== val
)
1710 all_values
= val
->next
;
1716 for (v
= all_values
; v
; v
= v
->next
)
1720 v
->next
= val
->next
;
1728 /* If the value is not already released, release it.
1729 If the value is already released, increment its reference count.
1730 That is, this function ensures that the value is released from the
1731 value chain and that the caller owns a reference to it. */
1734 release_value_or_incref (struct value
*val
)
1739 release_value (val
);
1742 /* Release all values up to mark */
1744 value_release_to_mark (const struct value
*mark
)
1749 for (val
= next
= all_values
; next
; next
= next
->next
)
1751 if (next
->next
== mark
)
1753 all_values
= next
->next
;
1763 /* Return a copy of the value ARG.
1764 It contains the same contents, for same memory address,
1765 but it's a different block of storage. */
1768 value_copy (struct value
*arg
)
1770 struct type
*encl_type
= value_enclosing_type (arg
);
1773 if (value_lazy (arg
))
1774 val
= allocate_value_lazy (encl_type
);
1776 val
= allocate_value (encl_type
);
1777 val
->type
= arg
->type
;
1778 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1779 val
->location
= arg
->location
;
1780 val
->offset
= arg
->offset
;
1781 val
->bitpos
= arg
->bitpos
;
1782 val
->bitsize
= arg
->bitsize
;
1783 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1784 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1785 val
->lazy
= arg
->lazy
;
1786 val
->embedded_offset
= value_embedded_offset (arg
);
1787 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1788 val
->modifiable
= arg
->modifiable
;
1789 if (!value_lazy (val
))
1791 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1792 TYPE_LENGTH (value_enclosing_type (arg
)));
1795 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1796 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1797 set_value_parent (val
, arg
->parent
);
1798 if (VALUE_LVAL (val
) == lval_computed
)
1800 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1802 if (funcs
->copy_closure
)
1803 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1808 /* Return a "const" and/or "volatile" qualified version of the value V.
1809 If CNST is true, then the returned value will be qualified with
1811 if VOLTL is true, then the returned value will be qualified with
1815 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1817 struct type
*val_type
= value_type (v
);
1818 struct type
*enclosing_type
= value_enclosing_type (v
);
1819 struct value
*cv_val
= value_copy (v
);
1821 deprecated_set_value_type (cv_val
,
1822 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1823 set_value_enclosing_type (cv_val
,
1824 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1829 /* Return a version of ARG that is non-lvalue. */
1832 value_non_lval (struct value
*arg
)
1834 if (VALUE_LVAL (arg
) != not_lval
)
1836 struct type
*enc_type
= value_enclosing_type (arg
);
1837 struct value
*val
= allocate_value (enc_type
);
1839 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1840 TYPE_LENGTH (enc_type
));
1841 val
->type
= arg
->type
;
1842 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1843 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1849 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1852 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1854 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1856 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1857 v
->lval
= lval_memory
;
1858 v
->location
.address
= addr
;
1862 set_value_component_location (struct value
*component
,
1863 const struct value
*whole
)
1867 gdb_assert (whole
->lval
!= lval_xcallable
);
1869 if (whole
->lval
== lval_internalvar
)
1870 VALUE_LVAL (component
) = lval_internalvar_component
;
1872 VALUE_LVAL (component
) = whole
->lval
;
1874 component
->location
= whole
->location
;
1875 if (whole
->lval
== lval_computed
)
1877 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1879 if (funcs
->copy_closure
)
1880 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1883 /* If type has a dynamic resolved location property
1884 update it's value address. */
1885 type
= value_type (whole
);
1886 if (NULL
!= TYPE_DATA_LOCATION (type
)
1887 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1888 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1891 /* Access to the value history. */
1893 /* Record a new value in the value history.
1894 Returns the absolute history index of the entry. */
1897 record_latest_value (struct value
*val
)
1901 /* We don't want this value to have anything to do with the inferior anymore.
1902 In particular, "set $1 = 50" should not affect the variable from which
1903 the value was taken, and fast watchpoints should be able to assume that
1904 a value on the value history never changes. */
1905 if (value_lazy (val
))
1906 value_fetch_lazy (val
);
1907 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1908 from. This is a bit dubious, because then *&$1 does not just return $1
1909 but the current contents of that location. c'est la vie... */
1910 val
->modifiable
= 0;
1912 /* The value may have already been released, in which case we're adding a
1913 new reference for its entry in the history. That is why we call
1914 release_value_or_incref here instead of release_value. */
1915 release_value_or_incref (val
);
1917 /* Here we treat value_history_count as origin-zero
1918 and applying to the value being stored now. */
1920 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1923 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1925 newobj
->next
= value_history_chain
;
1926 value_history_chain
= newobj
;
1929 value_history_chain
->values
[i
] = val
;
1931 /* Now we regard value_history_count as origin-one
1932 and applying to the value just stored. */
1934 return ++value_history_count
;
1937 /* Return a copy of the value in the history with sequence number NUM. */
1940 access_value_history (int num
)
1942 struct value_history_chunk
*chunk
;
1947 absnum
+= value_history_count
;
1952 error (_("The history is empty."));
1954 error (_("There is only one value in the history."));
1956 error (_("History does not go back to $$%d."), -num
);
1958 if (absnum
> value_history_count
)
1959 error (_("History has not yet reached $%d."), absnum
);
1963 /* Now absnum is always absolute and origin zero. */
1965 chunk
= value_history_chain
;
1966 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1967 - absnum
/ VALUE_HISTORY_CHUNK
;
1969 chunk
= chunk
->next
;
1971 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1975 show_values (char *num_exp
, int from_tty
)
1983 /* "show values +" should print from the stored position.
1984 "show values <exp>" should print around value number <exp>. */
1985 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1986 num
= parse_and_eval_long (num_exp
) - 5;
1990 /* "show values" means print the last 10 values. */
1991 num
= value_history_count
- 9;
1997 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1999 struct value_print_options opts
;
2001 val
= access_value_history (i
);
2002 printf_filtered (("$%d = "), i
);
2003 get_user_print_options (&opts
);
2004 value_print (val
, gdb_stdout
, &opts
);
2005 printf_filtered (("\n"));
2008 /* The next "show values +" should start after what we just printed. */
2011 /* Hitting just return after this command should do the same thing as
2012 "show values +". If num_exp is null, this is unnecessary, since
2013 "show values +" is not useful after "show values". */
2014 if (from_tty
&& num_exp
)
2021 enum internalvar_kind
2023 /* The internal variable is empty. */
2026 /* The value of the internal variable is provided directly as
2027 a GDB value object. */
2030 /* A fresh value is computed via a call-back routine on every
2031 access to the internal variable. */
2032 INTERNALVAR_MAKE_VALUE
,
2034 /* The internal variable holds a GDB internal convenience function. */
2035 INTERNALVAR_FUNCTION
,
2037 /* The variable holds an integer value. */
2038 INTERNALVAR_INTEGER
,
2040 /* The variable holds a GDB-provided string. */
2044 union internalvar_data
2046 /* A value object used with INTERNALVAR_VALUE. */
2047 struct value
*value
;
2049 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2052 /* The functions to call. */
2053 const struct internalvar_funcs
*functions
;
2055 /* The function's user-data. */
2059 /* The internal function used with INTERNALVAR_FUNCTION. */
2062 struct internal_function
*function
;
2063 /* True if this is the canonical name for the function. */
2067 /* An integer value used with INTERNALVAR_INTEGER. */
2070 /* If type is non-NULL, it will be used as the type to generate
2071 a value for this internal variable. If type is NULL, a default
2072 integer type for the architecture is used. */
2077 /* A string value used with INTERNALVAR_STRING. */
2081 /* Internal variables. These are variables within the debugger
2082 that hold values assigned by debugger commands.
2083 The user refers to them with a '$' prefix
2084 that does not appear in the variable names stored internally. */
2088 struct internalvar
*next
;
2091 /* We support various different kinds of content of an internal variable.
2092 enum internalvar_kind specifies the kind, and union internalvar_data
2093 provides the data associated with this particular kind. */
2095 enum internalvar_kind kind
;
2097 union internalvar_data u
;
2100 static struct internalvar
*internalvars
;
2102 /* If the variable does not already exist create it and give it the
2103 value given. If no value is given then the default is zero. */
2105 init_if_undefined_command (char* args
, int from_tty
)
2107 struct internalvar
* intvar
;
2109 /* Parse the expression - this is taken from set_command(). */
2110 struct expression
*expr
= parse_expression (args
);
2111 register struct cleanup
*old_chain
=
2112 make_cleanup (free_current_contents
, &expr
);
2114 /* Validate the expression.
2115 Was the expression an assignment?
2116 Or even an expression at all? */
2117 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2118 error (_("Init-if-undefined requires an assignment expression."));
2120 /* Extract the variable from the parsed expression.
2121 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2122 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2123 error (_("The first parameter to init-if-undefined "
2124 "should be a GDB variable."));
2125 intvar
= expr
->elts
[2].internalvar
;
2127 /* Only evaluate the expression if the lvalue is void.
2128 This may still fail if the expresssion is invalid. */
2129 if (intvar
->kind
== INTERNALVAR_VOID
)
2130 evaluate_expression (expr
);
2132 do_cleanups (old_chain
);
2136 /* Look up an internal variable with name NAME. NAME should not
2137 normally include a dollar sign.
2139 If the specified internal variable does not exist,
2140 the return value is NULL. */
2142 struct internalvar
*
2143 lookup_only_internalvar (const char *name
)
2145 struct internalvar
*var
;
2147 for (var
= internalvars
; var
; var
= var
->next
)
2148 if (strcmp (var
->name
, name
) == 0)
2154 /* Complete NAME by comparing it to the names of internal variables.
2155 Returns a vector of newly allocated strings, or NULL if no matches
2159 complete_internalvar (const char *name
)
2161 VEC (char_ptr
) *result
= NULL
;
2162 struct internalvar
*var
;
2165 len
= strlen (name
);
2167 for (var
= internalvars
; var
; var
= var
->next
)
2168 if (strncmp (var
->name
, name
, len
) == 0)
2170 char *r
= xstrdup (var
->name
);
2172 VEC_safe_push (char_ptr
, result
, r
);
2178 /* Create an internal variable with name NAME and with a void value.
2179 NAME should not normally include a dollar sign. */
2181 struct internalvar
*
2182 create_internalvar (const char *name
)
2184 struct internalvar
*var
= XNEW (struct internalvar
);
2186 var
->name
= concat (name
, (char *)NULL
);
2187 var
->kind
= INTERNALVAR_VOID
;
2188 var
->next
= internalvars
;
2193 /* Create an internal variable with name NAME and register FUN as the
2194 function that value_of_internalvar uses to create a value whenever
2195 this variable is referenced. NAME should not normally include a
2196 dollar sign. DATA is passed uninterpreted to FUN when it is
2197 called. CLEANUP, if not NULL, is called when the internal variable
2198 is destroyed. It is passed DATA as its only argument. */
2200 struct internalvar
*
2201 create_internalvar_type_lazy (const char *name
,
2202 const struct internalvar_funcs
*funcs
,
2205 struct internalvar
*var
= create_internalvar (name
);
2207 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2208 var
->u
.make_value
.functions
= funcs
;
2209 var
->u
.make_value
.data
= data
;
2213 /* See documentation in value.h. */
2216 compile_internalvar_to_ax (struct internalvar
*var
,
2217 struct agent_expr
*expr
,
2218 struct axs_value
*value
)
2220 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2221 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2224 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2225 var
->u
.make_value
.data
);
2229 /* Look up an internal variable with name NAME. NAME should not
2230 normally include a dollar sign.
2232 If the specified internal variable does not exist,
2233 one is created, with a void value. */
2235 struct internalvar
*
2236 lookup_internalvar (const char *name
)
2238 struct internalvar
*var
;
2240 var
= lookup_only_internalvar (name
);
2244 return create_internalvar (name
);
2247 /* Return current value of internal variable VAR. For variables that
2248 are not inherently typed, use a value type appropriate for GDBARCH. */
2251 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2254 struct trace_state_variable
*tsv
;
2256 /* If there is a trace state variable of the same name, assume that
2257 is what we really want to see. */
2258 tsv
= find_trace_state_variable (var
->name
);
2261 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2263 if (tsv
->value_known
)
2264 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2267 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2273 case INTERNALVAR_VOID
:
2274 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2277 case INTERNALVAR_FUNCTION
:
2278 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2281 case INTERNALVAR_INTEGER
:
2282 if (!var
->u
.integer
.type
)
2283 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2284 var
->u
.integer
.val
);
2286 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2289 case INTERNALVAR_STRING
:
2290 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2291 builtin_type (gdbarch
)->builtin_char
);
2294 case INTERNALVAR_VALUE
:
2295 val
= value_copy (var
->u
.value
);
2296 if (value_lazy (val
))
2297 value_fetch_lazy (val
);
2300 case INTERNALVAR_MAKE_VALUE
:
2301 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2302 var
->u
.make_value
.data
);
2306 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2309 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2310 on this value go back to affect the original internal variable.
2312 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2313 no underlying modifyable state in the internal variable.
2315 Likewise, if the variable's value is a computed lvalue, we want
2316 references to it to produce another computed lvalue, where
2317 references and assignments actually operate through the
2318 computed value's functions.
2320 This means that internal variables with computed values
2321 behave a little differently from other internal variables:
2322 assignments to them don't just replace the previous value
2323 altogether. At the moment, this seems like the behavior we
2326 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2327 && val
->lval
!= lval_computed
)
2329 VALUE_LVAL (val
) = lval_internalvar
;
2330 VALUE_INTERNALVAR (val
) = var
;
2337 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2339 if (var
->kind
== INTERNALVAR_INTEGER
)
2341 *result
= var
->u
.integer
.val
;
2345 if (var
->kind
== INTERNALVAR_VALUE
)
2347 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2349 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2351 *result
= value_as_long (var
->u
.value
);
2360 get_internalvar_function (struct internalvar
*var
,
2361 struct internal_function
**result
)
2365 case INTERNALVAR_FUNCTION
:
2366 *result
= var
->u
.fn
.function
;
2375 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
2376 int bitsize
, struct value
*newval
)
2379 struct gdbarch
*arch
;
2384 case INTERNALVAR_VALUE
:
2385 addr
= value_contents_writeable (var
->u
.value
);
2386 arch
= get_value_arch (var
->u
.value
);
2387 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2390 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2391 value_as_long (newval
), bitpos
, bitsize
);
2393 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2394 TYPE_LENGTH (value_type (newval
)));
2398 /* We can never get a component of any other kind. */
2399 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2404 set_internalvar (struct internalvar
*var
, struct value
*val
)
2406 enum internalvar_kind new_kind
;
2407 union internalvar_data new_data
= { 0 };
2409 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2410 error (_("Cannot overwrite convenience function %s"), var
->name
);
2412 /* Prepare new contents. */
2413 switch (TYPE_CODE (check_typedef (value_type (val
))))
2415 case TYPE_CODE_VOID
:
2416 new_kind
= INTERNALVAR_VOID
;
2419 case TYPE_CODE_INTERNAL_FUNCTION
:
2420 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2421 new_kind
= INTERNALVAR_FUNCTION
;
2422 get_internalvar_function (VALUE_INTERNALVAR (val
),
2423 &new_data
.fn
.function
);
2424 /* Copies created here are never canonical. */
2428 new_kind
= INTERNALVAR_VALUE
;
2429 new_data
.value
= value_copy (val
);
2430 new_data
.value
->modifiable
= 1;
2432 /* Force the value to be fetched from the target now, to avoid problems
2433 later when this internalvar is referenced and the target is gone or
2435 if (value_lazy (new_data
.value
))
2436 value_fetch_lazy (new_data
.value
);
2438 /* Release the value from the value chain to prevent it from being
2439 deleted by free_all_values. From here on this function should not
2440 call error () until new_data is installed into the var->u to avoid
2442 release_value (new_data
.value
);
2444 /* Internal variables which are created from values with a dynamic
2445 location don't need the location property of the origin anymore.
2446 The resolved dynamic location is used prior then any other address
2447 when accessing the value.
2448 If we keep it, we would still refer to the origin value.
2449 Remove the location property in case it exist. */
2450 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2455 /* Clean up old contents. */
2456 clear_internalvar (var
);
2459 var
->kind
= new_kind
;
2461 /* End code which must not call error(). */
2465 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2467 /* Clean up old contents. */
2468 clear_internalvar (var
);
2470 var
->kind
= INTERNALVAR_INTEGER
;
2471 var
->u
.integer
.type
= NULL
;
2472 var
->u
.integer
.val
= l
;
2476 set_internalvar_string (struct internalvar
*var
, const char *string
)
2478 /* Clean up old contents. */
2479 clear_internalvar (var
);
2481 var
->kind
= INTERNALVAR_STRING
;
2482 var
->u
.string
= xstrdup (string
);
2486 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2488 /* Clean up old contents. */
2489 clear_internalvar (var
);
2491 var
->kind
= INTERNALVAR_FUNCTION
;
2492 var
->u
.fn
.function
= f
;
2493 var
->u
.fn
.canonical
= 1;
2494 /* Variables installed here are always the canonical version. */
2498 clear_internalvar (struct internalvar
*var
)
2500 /* Clean up old contents. */
2503 case INTERNALVAR_VALUE
:
2504 value_free (var
->u
.value
);
2507 case INTERNALVAR_STRING
:
2508 xfree (var
->u
.string
);
2511 case INTERNALVAR_MAKE_VALUE
:
2512 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2513 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2520 /* Reset to void kind. */
2521 var
->kind
= INTERNALVAR_VOID
;
2525 internalvar_name (const struct internalvar
*var
)
2530 static struct internal_function
*
2531 create_internal_function (const char *name
,
2532 internal_function_fn handler
, void *cookie
)
2534 struct internal_function
*ifn
= XNEW (struct internal_function
);
2536 ifn
->name
= xstrdup (name
);
2537 ifn
->handler
= handler
;
2538 ifn
->cookie
= cookie
;
2543 value_internal_function_name (struct value
*val
)
2545 struct internal_function
*ifn
;
2548 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2549 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2550 gdb_assert (result
);
2556 call_internal_function (struct gdbarch
*gdbarch
,
2557 const struct language_defn
*language
,
2558 struct value
*func
, int argc
, struct value
**argv
)
2560 struct internal_function
*ifn
;
2563 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2564 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2565 gdb_assert (result
);
2567 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2570 /* The 'function' command. This does nothing -- it is just a
2571 placeholder to let "help function NAME" work. This is also used as
2572 the implementation of the sub-command that is created when
2573 registering an internal function. */
2575 function_command (char *command
, int from_tty
)
2580 /* Clean up if an internal function's command is destroyed. */
2582 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2584 xfree ((char *) self
->name
);
2585 xfree ((char *) self
->doc
);
2588 /* Add a new internal function. NAME is the name of the function; DOC
2589 is a documentation string describing the function. HANDLER is
2590 called when the function is invoked. COOKIE is an arbitrary
2591 pointer which is passed to HANDLER and is intended for "user
2594 add_internal_function (const char *name
, const char *doc
,
2595 internal_function_fn handler
, void *cookie
)
2597 struct cmd_list_element
*cmd
;
2598 struct internal_function
*ifn
;
2599 struct internalvar
*var
= lookup_internalvar (name
);
2601 ifn
= create_internal_function (name
, handler
, cookie
);
2602 set_internalvar_function (var
, ifn
);
2604 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2606 cmd
->destroyer
= function_destroyer
;
2609 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2610 prevent cycles / duplicates. */
2613 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2614 htab_t copied_types
)
2616 if (TYPE_OBJFILE (value
->type
) == objfile
)
2617 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2619 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2620 value
->enclosing_type
= copy_type_recursive (objfile
,
2621 value
->enclosing_type
,
2625 /* Likewise for internal variable VAR. */
2628 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2629 htab_t copied_types
)
2633 case INTERNALVAR_INTEGER
:
2634 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2636 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2639 case INTERNALVAR_VALUE
:
2640 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2645 /* Update the internal variables and value history when OBJFILE is
2646 discarded; we must copy the types out of the objfile. New global types
2647 will be created for every convenience variable which currently points to
2648 this objfile's types, and the convenience variables will be adjusted to
2649 use the new global types. */
2652 preserve_values (struct objfile
*objfile
)
2654 htab_t copied_types
;
2655 struct value_history_chunk
*cur
;
2656 struct internalvar
*var
;
2659 /* Create the hash table. We allocate on the objfile's obstack, since
2660 it is soon to be deleted. */
2661 copied_types
= create_copied_types_hash (objfile
);
2663 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2664 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2666 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2668 for (var
= internalvars
; var
; var
= var
->next
)
2669 preserve_one_internalvar (var
, objfile
, copied_types
);
2671 preserve_ext_lang_values (objfile
, copied_types
);
2673 htab_delete (copied_types
);
2677 show_convenience (char *ignore
, int from_tty
)
2679 struct gdbarch
*gdbarch
= get_current_arch ();
2680 struct internalvar
*var
;
2682 struct value_print_options opts
;
2684 get_user_print_options (&opts
);
2685 for (var
= internalvars
; var
; var
= var
->next
)
2692 printf_filtered (("$%s = "), var
->name
);
2698 val
= value_of_internalvar (gdbarch
, var
);
2699 value_print (val
, gdb_stdout
, &opts
);
2701 CATCH (ex
, RETURN_MASK_ERROR
)
2703 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2707 printf_filtered (("\n"));
2711 /* This text does not mention convenience functions on purpose.
2712 The user can't create them except via Python, and if Python support
2713 is installed this message will never be printed ($_streq will
2715 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2716 "Convenience variables have "
2717 "names starting with \"$\";\n"
2718 "use \"set\" as in \"set "
2719 "$foo = 5\" to define them.\n"));
2723 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2726 value_of_xmethod (struct xmethod_worker
*worker
)
2728 if (worker
->value
== NULL
)
2732 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2733 v
->lval
= lval_xcallable
;
2734 v
->location
.xm_worker
= worker
;
2739 return worker
->value
;
2742 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2745 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2747 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2748 && method
->lval
== lval_xcallable
&& argc
> 0);
2750 return get_xmethod_result_type (method
->location
.xm_worker
,
2751 argv
[0], argv
+ 1, argc
- 1);
2754 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2757 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2759 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2760 && method
->lval
== lval_xcallable
&& argc
> 0);
2762 return invoke_xmethod (method
->location
.xm_worker
,
2763 argv
[0], argv
+ 1, argc
- 1);
2766 /* Extract a value as a C number (either long or double).
2767 Knows how to convert fixed values to double, or
2768 floating values to long.
2769 Does not deallocate the value. */
2772 value_as_long (struct value
*val
)
2774 /* This coerces arrays and functions, which is necessary (e.g.
2775 in disassemble_command). It also dereferences references, which
2776 I suspect is the most logical thing to do. */
2777 val
= coerce_array (val
);
2778 return unpack_long (value_type (val
), value_contents (val
));
2782 value_as_double (struct value
*val
)
2787 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2789 error (_("Invalid floating value found in program."));
2793 /* Extract a value as a C pointer. Does not deallocate the value.
2794 Note that val's type may not actually be a pointer; value_as_long
2795 handles all the cases. */
2797 value_as_address (struct value
*val
)
2799 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2801 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2802 whether we want this to be true eventually. */
2804 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2805 non-address (e.g. argument to "signal", "info break", etc.), or
2806 for pointers to char, in which the low bits *are* significant. */
2807 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2810 /* There are several targets (IA-64, PowerPC, and others) which
2811 don't represent pointers to functions as simply the address of
2812 the function's entry point. For example, on the IA-64, a
2813 function pointer points to a two-word descriptor, generated by
2814 the linker, which contains the function's entry point, and the
2815 value the IA-64 "global pointer" register should have --- to
2816 support position-independent code. The linker generates
2817 descriptors only for those functions whose addresses are taken.
2819 On such targets, it's difficult for GDB to convert an arbitrary
2820 function address into a function pointer; it has to either find
2821 an existing descriptor for that function, or call malloc and
2822 build its own. On some targets, it is impossible for GDB to
2823 build a descriptor at all: the descriptor must contain a jump
2824 instruction; data memory cannot be executed; and code memory
2827 Upon entry to this function, if VAL is a value of type `function'
2828 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2829 value_address (val) is the address of the function. This is what
2830 you'll get if you evaluate an expression like `main'. The call
2831 to COERCE_ARRAY below actually does all the usual unary
2832 conversions, which includes converting values of type `function'
2833 to `pointer to function'. This is the challenging conversion
2834 discussed above. Then, `unpack_long' will convert that pointer
2835 back into an address.
2837 So, suppose the user types `disassemble foo' on an architecture
2838 with a strange function pointer representation, on which GDB
2839 cannot build its own descriptors, and suppose further that `foo'
2840 has no linker-built descriptor. The address->pointer conversion
2841 will signal an error and prevent the command from running, even
2842 though the next step would have been to convert the pointer
2843 directly back into the same address.
2845 The following shortcut avoids this whole mess. If VAL is a
2846 function, just return its address directly. */
2847 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2848 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2849 return value_address (val
);
2851 val
= coerce_array (val
);
2853 /* Some architectures (e.g. Harvard), map instruction and data
2854 addresses onto a single large unified address space. For
2855 instance: An architecture may consider a large integer in the
2856 range 0x10000000 .. 0x1000ffff to already represent a data
2857 addresses (hence not need a pointer to address conversion) while
2858 a small integer would still need to be converted integer to
2859 pointer to address. Just assume such architectures handle all
2860 integer conversions in a single function. */
2864 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2865 must admonish GDB hackers to make sure its behavior matches the
2866 compiler's, whenever possible.
2868 In general, I think GDB should evaluate expressions the same way
2869 the compiler does. When the user copies an expression out of
2870 their source code and hands it to a `print' command, they should
2871 get the same value the compiler would have computed. Any
2872 deviation from this rule can cause major confusion and annoyance,
2873 and needs to be justified carefully. In other words, GDB doesn't
2874 really have the freedom to do these conversions in clever and
2877 AndrewC pointed out that users aren't complaining about how GDB
2878 casts integers to pointers; they are complaining that they can't
2879 take an address from a disassembly listing and give it to `x/i'.
2880 This is certainly important.
2882 Adding an architecture method like integer_to_address() certainly
2883 makes it possible for GDB to "get it right" in all circumstances
2884 --- the target has complete control over how things get done, so
2885 people can Do The Right Thing for their target without breaking
2886 anyone else. The standard doesn't specify how integers get
2887 converted to pointers; usually, the ABI doesn't either, but
2888 ABI-specific code is a more reasonable place to handle it. */
2890 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2891 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2892 && gdbarch_integer_to_address_p (gdbarch
))
2893 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2894 value_contents (val
));
2896 return unpack_long (value_type (val
), value_contents (val
));
2900 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2901 as a long, or as a double, assuming the raw data is described
2902 by type TYPE. Knows how to convert different sizes of values
2903 and can convert between fixed and floating point. We don't assume
2904 any alignment for the raw data. Return value is in host byte order.
2906 If you want functions and arrays to be coerced to pointers, and
2907 references to be dereferenced, call value_as_long() instead.
2909 C++: It is assumed that the front-end has taken care of
2910 all matters concerning pointers to members. A pointer
2911 to member which reaches here is considered to be equivalent
2912 to an INT (or some size). After all, it is only an offset. */
2915 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2917 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2918 enum type_code code
= TYPE_CODE (type
);
2919 int len
= TYPE_LENGTH (type
);
2920 int nosign
= TYPE_UNSIGNED (type
);
2924 case TYPE_CODE_TYPEDEF
:
2925 return unpack_long (check_typedef (type
), valaddr
);
2926 case TYPE_CODE_ENUM
:
2927 case TYPE_CODE_FLAGS
:
2928 case TYPE_CODE_BOOL
:
2930 case TYPE_CODE_CHAR
:
2931 case TYPE_CODE_RANGE
:
2932 case TYPE_CODE_MEMBERPTR
:
2934 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2936 return extract_signed_integer (valaddr
, len
, byte_order
);
2939 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2941 case TYPE_CODE_DECFLOAT
:
2942 /* libdecnumber has a function to convert from decimal to integer, but
2943 it doesn't work when the decimal number has a fractional part. */
2944 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2948 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2949 whether we want this to be true eventually. */
2950 return extract_typed_address (valaddr
, type
);
2953 error (_("Value can't be converted to integer."));
2955 return 0; /* Placate lint. */
2958 /* Return a double value from the specified type and address.
2959 INVP points to an int which is set to 0 for valid value,
2960 1 for invalid value (bad float format). In either case,
2961 the returned double is OK to use. Argument is in target
2962 format, result is in host format. */
2965 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2967 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2968 enum type_code code
;
2972 *invp
= 0; /* Assume valid. */
2973 type
= check_typedef (type
);
2974 code
= TYPE_CODE (type
);
2975 len
= TYPE_LENGTH (type
);
2976 nosign
= TYPE_UNSIGNED (type
);
2977 if (code
== TYPE_CODE_FLT
)
2979 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2980 floating-point value was valid (using the macro
2981 INVALID_FLOAT). That test/macro have been removed.
2983 It turns out that only the VAX defined this macro and then
2984 only in a non-portable way. Fixing the portability problem
2985 wouldn't help since the VAX floating-point code is also badly
2986 bit-rotten. The target needs to add definitions for the
2987 methods gdbarch_float_format and gdbarch_double_format - these
2988 exactly describe the target floating-point format. The
2989 problem here is that the corresponding floatformat_vax_f and
2990 floatformat_vax_d values these methods should be set to are
2991 also not defined either. Oops!
2993 Hopefully someone will add both the missing floatformat
2994 definitions and the new cases for floatformat_is_valid (). */
2996 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
3002 return extract_typed_floating (valaddr
, type
);
3004 else if (code
== TYPE_CODE_DECFLOAT
)
3005 return decimal_to_doublest (valaddr
, len
, byte_order
);
3008 /* Unsigned -- be sure we compensate for signed LONGEST. */
3009 return (ULONGEST
) unpack_long (type
, valaddr
);
3013 /* Signed -- we are OK with unpack_long. */
3014 return unpack_long (type
, valaddr
);
3018 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3019 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3020 We don't assume any alignment for the raw data. Return value is in
3023 If you want functions and arrays to be coerced to pointers, and
3024 references to be dereferenced, call value_as_address() instead.
3026 C++: It is assumed that the front-end has taken care of
3027 all matters concerning pointers to members. A pointer
3028 to member which reaches here is considered to be equivalent
3029 to an INT (or some size). After all, it is only an offset. */
3032 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3034 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3035 whether we want this to be true eventually. */
3036 return unpack_long (type
, valaddr
);
3040 /* Get the value of the FIELDNO'th field (which must be static) of
3044 value_static_field (struct type
*type
, int fieldno
)
3046 struct value
*retval
;
3048 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3050 case FIELD_LOC_KIND_PHYSADDR
:
3051 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3052 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3054 case FIELD_LOC_KIND_PHYSNAME
:
3056 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3057 /* TYPE_FIELD_NAME (type, fieldno); */
3058 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3060 if (sym
.symbol
== NULL
)
3062 /* With some compilers, e.g. HP aCC, static data members are
3063 reported as non-debuggable symbols. */
3064 struct bound_minimal_symbol msym
3065 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3068 return allocate_optimized_out_value (type
);
3071 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3072 BMSYMBOL_VALUE_ADDRESS (msym
));
3076 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3080 gdb_assert_not_reached ("unexpected field location kind");
3086 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3087 You have to be careful here, since the size of the data area for the value
3088 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3089 than the old enclosing type, you have to allocate more space for the
3093 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3095 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3097 check_type_length_before_alloc (new_encl_type
);
3099 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3102 val
->enclosing_type
= new_encl_type
;
3105 /* Given a value ARG1 (offset by OFFSET bytes)
3106 of a struct or union type ARG_TYPE,
3107 extract and return the value of one of its (non-static) fields.
3108 FIELDNO says which field. */
3111 value_primitive_field (struct value
*arg1
, int offset
,
3112 int fieldno
, struct type
*arg_type
)
3116 struct gdbarch
*arch
= get_value_arch (arg1
);
3117 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3119 arg_type
= check_typedef (arg_type
);
3120 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3122 /* Call check_typedef on our type to make sure that, if TYPE
3123 is a TYPE_CODE_TYPEDEF, its length is set to the length
3124 of the target type instead of zero. However, we do not
3125 replace the typedef type by the target type, because we want
3126 to keep the typedef in order to be able to print the type
3127 description correctly. */
3128 check_typedef (type
);
3130 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3132 /* Handle packed fields.
3134 Create a new value for the bitfield, with bitpos and bitsize
3135 set. If possible, arrange offset and bitpos so that we can
3136 do a single aligned read of the size of the containing type.
3137 Otherwise, adjust offset to the byte containing the first
3138 bit. Assume that the address, offset, and embedded offset
3139 are sufficiently aligned. */
3141 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3142 int container_bitsize
= TYPE_LENGTH (type
) * 8;
3144 v
= allocate_value_lazy (type
);
3145 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3146 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3147 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3148 v
->bitpos
= bitpos
% container_bitsize
;
3150 v
->bitpos
= bitpos
% 8;
3151 v
->offset
= (value_embedded_offset (arg1
)
3153 + (bitpos
- v
->bitpos
) / 8);
3154 set_value_parent (v
, arg1
);
3155 if (!value_lazy (arg1
))
3156 value_fetch_lazy (v
);
3158 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3160 /* This field is actually a base subobject, so preserve the
3161 entire object's contents for later references to virtual
3165 /* Lazy register values with offsets are not supported. */
3166 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3167 value_fetch_lazy (arg1
);
3169 /* We special case virtual inheritance here because this
3170 requires access to the contents, which we would rather avoid
3171 for references to ordinary fields of unavailable values. */
3172 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3173 boffset
= baseclass_offset (arg_type
, fieldno
,
3174 value_contents (arg1
),
3175 value_embedded_offset (arg1
),
3176 value_address (arg1
),
3179 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3181 if (value_lazy (arg1
))
3182 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3185 v
= allocate_value (value_enclosing_type (arg1
));
3186 value_contents_copy_raw (v
, 0, arg1
, 0,
3187 TYPE_LENGTH (value_enclosing_type (arg1
)));
3190 v
->offset
= value_offset (arg1
);
3191 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3193 else if (NULL
!= TYPE_DATA_LOCATION (type
))
3195 /* Field is a dynamic data member. */
3197 gdb_assert (0 == offset
);
3198 /* We expect an already resolved data location. */
3199 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
3200 /* For dynamic data types defer memory allocation
3201 until we actual access the value. */
3202 v
= allocate_value_lazy (type
);
3206 /* Plain old data member */
3207 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3208 / (HOST_CHAR_BIT
* unit_size
));
3210 /* Lazy register values with offsets are not supported. */
3211 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3212 value_fetch_lazy (arg1
);
3214 if (value_lazy (arg1
))
3215 v
= allocate_value_lazy (type
);
3218 v
= allocate_value (type
);
3219 value_contents_copy_raw (v
, value_embedded_offset (v
),
3220 arg1
, value_embedded_offset (arg1
) + offset
,
3221 type_length_units (type
));
3223 v
->offset
= (value_offset (arg1
) + offset
3224 + value_embedded_offset (arg1
));
3226 set_value_component_location (v
, arg1
);
3227 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
3228 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
3232 /* Given a value ARG1 of a struct or union type,
3233 extract and return the value of one of its (non-static) fields.
3234 FIELDNO says which field. */
3237 value_field (struct value
*arg1
, int fieldno
)
3239 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3242 /* Return a non-virtual function as a value.
3243 F is the list of member functions which contains the desired method.
3244 J is an index into F which provides the desired method.
3246 We only use the symbol for its address, so be happy with either a
3247 full symbol or a minimal symbol. */
3250 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3251 int j
, struct type
*type
,
3255 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3256 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3258 struct bound_minimal_symbol msym
;
3260 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3263 memset (&msym
, 0, sizeof (msym
));
3267 gdb_assert (sym
== NULL
);
3268 msym
= lookup_bound_minimal_symbol (physname
);
3269 if (msym
.minsym
== NULL
)
3273 v
= allocate_value (ftype
);
3276 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3280 /* The minimal symbol might point to a function descriptor;
3281 resolve it to the actual code address instead. */
3282 struct objfile
*objfile
= msym
.objfile
;
3283 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3285 set_value_address (v
,
3286 gdbarch_convert_from_func_ptr_addr
3287 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3292 if (type
!= value_type (*arg1p
))
3293 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3294 value_addr (*arg1p
)));
3296 /* Move the `this' pointer according to the offset.
3297 VALUE_OFFSET (*arg1p) += offset; */
3305 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3306 VALADDR, and store the result in *RESULT.
3307 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3309 Extracting bits depends on endianness of the machine. Compute the
3310 number of least significant bits to discard. For big endian machines,
3311 we compute the total number of bits in the anonymous object, subtract
3312 off the bit count from the MSB of the object to the MSB of the
3313 bitfield, then the size of the bitfield, which leaves the LSB discard
3314 count. For little endian machines, the discard count is simply the
3315 number of bits from the LSB of the anonymous object to the LSB of the
3318 If the field is signed, we also do sign extension. */
3321 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3322 int bitpos
, int bitsize
)
3324 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3331 /* Read the minimum number of bytes required; there may not be
3332 enough bytes to read an entire ULONGEST. */
3333 field_type
= check_typedef (field_type
);
3335 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3337 bytes_read
= TYPE_LENGTH (field_type
);
3339 read_offset
= bitpos
/ 8;
3341 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3342 bytes_read
, byte_order
);
3344 /* Extract bits. See comment above. */
3346 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3347 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3349 lsbcount
= (bitpos
% 8);
3352 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3353 If the field is signed, and is negative, then sign extend. */
3355 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3357 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3359 if (!TYPE_UNSIGNED (field_type
))
3361 if (val
& (valmask
^ (valmask
>> 1)))
3371 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3372 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3373 ORIGINAL_VALUE, which must not be NULL. See
3374 unpack_value_bits_as_long for more details. */
3377 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3378 int embedded_offset
, int fieldno
,
3379 const struct value
*val
, LONGEST
*result
)
3381 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3382 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3383 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3386 gdb_assert (val
!= NULL
);
3388 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3389 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3390 || !value_bits_available (val
, bit_offset
, bitsize
))
3393 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3398 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3399 object at VALADDR. See unpack_bits_as_long for more details. */
3402 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3404 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3405 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3406 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3408 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3411 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3412 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3413 the contents in DEST_VAL, zero or sign extending if the type of
3414 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3415 VAL. If the VAL's contents required to extract the bitfield from
3416 are unavailable/optimized out, DEST_VAL is correspondingly
3417 marked unavailable/optimized out. */
3420 unpack_value_bitfield (struct value
*dest_val
,
3421 int bitpos
, int bitsize
,
3422 const gdb_byte
*valaddr
, int embedded_offset
,
3423 const struct value
*val
)
3425 enum bfd_endian byte_order
;
3429 struct type
*field_type
= value_type (dest_val
);
3431 /* First, unpack and sign extend the bitfield as if it was wholly
3432 available. Invalid/unavailable bits are read as zero, but that's
3433 OK, as they'll end up marked below. */
3434 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3435 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3437 store_signed_integer (value_contents_raw (dest_val
),
3438 TYPE_LENGTH (field_type
), byte_order
, num
);
3440 /* Now copy the optimized out / unavailability ranges to the right
3442 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3443 if (byte_order
== BFD_ENDIAN_BIG
)
3444 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3447 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3448 val
, src_bit_offset
, bitsize
);
3451 /* Return a new value with type TYPE, which is FIELDNO field of the
3452 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3453 of VAL. If the VAL's contents required to extract the bitfield
3454 from are unavailable/optimized out, the new value is
3455 correspondingly marked unavailable/optimized out. */
3458 value_field_bitfield (struct type
*type
, int fieldno
,
3459 const gdb_byte
*valaddr
,
3460 int embedded_offset
, const struct value
*val
)
3462 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3463 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3464 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3466 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3467 valaddr
, embedded_offset
, val
);
3472 /* Modify the value of a bitfield. ADDR points to a block of memory in
3473 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3474 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3475 indicate which bits (in target bit order) comprise the bitfield.
3476 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3477 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3480 modify_field (struct type
*type
, gdb_byte
*addr
,
3481 LONGEST fieldval
, int bitpos
, int bitsize
)
3483 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3485 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3488 /* Normalize BITPOS. */
3492 /* If a negative fieldval fits in the field in question, chop
3493 off the sign extension bits. */
3494 if ((~fieldval
& ~(mask
>> 1)) == 0)
3497 /* Warn if value is too big to fit in the field in question. */
3498 if (0 != (fieldval
& ~mask
))
3500 /* FIXME: would like to include fieldval in the message, but
3501 we don't have a sprintf_longest. */
3502 warning (_("Value does not fit in %d bits."), bitsize
);
3504 /* Truncate it, otherwise adjoining fields may be corrupted. */
3508 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3509 false valgrind reports. */
3511 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3512 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3514 /* Shifting for bit field depends on endianness of the target machine. */
3515 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3516 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3518 oword
&= ~(mask
<< bitpos
);
3519 oword
|= fieldval
<< bitpos
;
3521 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3524 /* Pack NUM into BUF using a target format of TYPE. */
3527 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3529 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3532 type
= check_typedef (type
);
3533 len
= TYPE_LENGTH (type
);
3535 switch (TYPE_CODE (type
))
3538 case TYPE_CODE_CHAR
:
3539 case TYPE_CODE_ENUM
:
3540 case TYPE_CODE_FLAGS
:
3541 case TYPE_CODE_BOOL
:
3542 case TYPE_CODE_RANGE
:
3543 case TYPE_CODE_MEMBERPTR
:
3544 store_signed_integer (buf
, len
, byte_order
, num
);
3549 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3553 error (_("Unexpected type (%d) encountered for integer constant."),
3559 /* Pack NUM into BUF using a target format of TYPE. */
3562 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3565 enum bfd_endian byte_order
;
3567 type
= check_typedef (type
);
3568 len
= TYPE_LENGTH (type
);
3569 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3571 switch (TYPE_CODE (type
))
3574 case TYPE_CODE_CHAR
:
3575 case TYPE_CODE_ENUM
:
3576 case TYPE_CODE_FLAGS
:
3577 case TYPE_CODE_BOOL
:
3578 case TYPE_CODE_RANGE
:
3579 case TYPE_CODE_MEMBERPTR
:
3580 store_unsigned_integer (buf
, len
, byte_order
, num
);
3585 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3589 error (_("Unexpected type (%d) encountered "
3590 "for unsigned integer constant."),
3596 /* Convert C numbers into newly allocated values. */
3599 value_from_longest (struct type
*type
, LONGEST num
)
3601 struct value
*val
= allocate_value (type
);
3603 pack_long (value_contents_raw (val
), type
, num
);
3608 /* Convert C unsigned numbers into newly allocated values. */
3611 value_from_ulongest (struct type
*type
, ULONGEST num
)
3613 struct value
*val
= allocate_value (type
);
3615 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3621 /* Create a value representing a pointer of type TYPE to the address
3625 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3627 struct value
*val
= allocate_value (type
);
3629 store_typed_address (value_contents_raw (val
),
3630 check_typedef (type
), addr
);
3635 /* Create a value of type TYPE whose contents come from VALADDR, if it
3636 is non-null, and whose memory address (in the inferior) is
3637 ADDRESS. The type of the created value may differ from the passed
3638 type TYPE. Make sure to retrieve values new type after this call.
3639 Note that TYPE is not passed through resolve_dynamic_type; this is
3640 a special API intended for use only by Ada. */
3643 value_from_contents_and_address_unresolved (struct type
*type
,
3644 const gdb_byte
*valaddr
,
3649 if (valaddr
== NULL
)
3650 v
= allocate_value_lazy (type
);
3652 v
= value_from_contents (type
, valaddr
);
3653 set_value_address (v
, address
);
3654 VALUE_LVAL (v
) = lval_memory
;
3658 /* Create a value of type TYPE whose contents come from VALADDR, if it
3659 is non-null, and whose memory address (in the inferior) is
3660 ADDRESS. The type of the created value may differ from the passed
3661 type TYPE. Make sure to retrieve values new type after this call. */
3664 value_from_contents_and_address (struct type
*type
,
3665 const gdb_byte
*valaddr
,
3668 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3669 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3672 if (valaddr
== NULL
)
3673 v
= allocate_value_lazy (resolved_type
);
3675 v
= value_from_contents (resolved_type
, valaddr
);
3676 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3677 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3678 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3679 set_value_address (v
, address
);
3680 VALUE_LVAL (v
) = lval_memory
;
3684 /* Create a value of type TYPE holding the contents CONTENTS.
3685 The new value is `not_lval'. */
3688 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3690 struct value
*result
;
3692 result
= allocate_value (type
);
3693 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3698 value_from_double (struct type
*type
, DOUBLEST num
)
3700 struct value
*val
= allocate_value (type
);
3701 struct type
*base_type
= check_typedef (type
);
3702 enum type_code code
= TYPE_CODE (base_type
);
3704 if (code
== TYPE_CODE_FLT
)
3706 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3709 error (_("Unexpected type encountered for floating constant."));
3715 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3717 struct value
*val
= allocate_value (type
);
3719 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3723 /* Extract a value from the history file. Input will be of the form
3724 $digits or $$digits. See block comment above 'write_dollar_variable'
3728 value_from_history_ref (const char *h
, const char **endp
)
3740 /* Find length of numeral string. */
3741 for (; isdigit (h
[len
]); len
++)
3744 /* Make sure numeral string is not part of an identifier. */
3745 if (h
[len
] == '_' || isalpha (h
[len
]))
3748 /* Now collect the index value. */
3753 /* For some bizarre reason, "$$" is equivalent to "$$1",
3754 rather than to "$$0" as it ought to be! */
3762 index
= -strtol (&h
[2], &local_end
, 10);
3770 /* "$" is equivalent to "$0". */
3778 index
= strtol (&h
[1], &local_end
, 10);
3783 return access_value_history (index
);
3787 coerce_ref_if_computed (const struct value
*arg
)
3789 const struct lval_funcs
*funcs
;
3791 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3794 if (value_lval_const (arg
) != lval_computed
)
3797 funcs
= value_computed_funcs (arg
);
3798 if (funcs
->coerce_ref
== NULL
)
3801 return funcs
->coerce_ref (arg
);
3804 /* Look at value.h for description. */
3807 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3808 const struct type
*original_type
,
3809 const struct value
*original_value
)
3811 /* Re-adjust type. */
3812 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3814 /* Add embedding info. */
3815 set_value_enclosing_type (value
, enc_type
);
3816 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3818 /* We may be pointing to an object of some derived type. */
3819 return value_full_object (value
, NULL
, 0, 0, 0);
3823 coerce_ref (struct value
*arg
)
3825 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3826 struct value
*retval
;
3827 struct type
*enc_type
;
3829 retval
= coerce_ref_if_computed (arg
);
3833 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3836 enc_type
= check_typedef (value_enclosing_type (arg
));
3837 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3839 retval
= value_at_lazy (enc_type
,
3840 unpack_pointer (value_type (arg
),
3841 value_contents (arg
)));
3842 enc_type
= value_type (retval
);
3843 return readjust_indirect_value_type (retval
, enc_type
,
3844 value_type_arg_tmp
, arg
);
3848 coerce_array (struct value
*arg
)
3852 arg
= coerce_ref (arg
);
3853 type
= check_typedef (value_type (arg
));
3855 switch (TYPE_CODE (type
))
3857 case TYPE_CODE_ARRAY
:
3858 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3859 arg
= value_coerce_array (arg
);
3861 case TYPE_CODE_FUNC
:
3862 arg
= value_coerce_function (arg
);
3869 /* Return the return value convention that will be used for the
3872 enum return_value_convention
3873 struct_return_convention (struct gdbarch
*gdbarch
,
3874 struct value
*function
, struct type
*value_type
)
3876 enum type_code code
= TYPE_CODE (value_type
);
3878 if (code
== TYPE_CODE_ERROR
)
3879 error (_("Function return type unknown."));
3881 /* Probe the architecture for the return-value convention. */
3882 return gdbarch_return_value (gdbarch
, function
, value_type
,
3886 /* Return true if the function returning the specified type is using
3887 the convention of returning structures in memory (passing in the
3888 address as a hidden first parameter). */
3891 using_struct_return (struct gdbarch
*gdbarch
,
3892 struct value
*function
, struct type
*value_type
)
3894 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3895 /* A void return value is never in memory. See also corresponding
3896 code in "print_return_value". */
3899 return (struct_return_convention (gdbarch
, function
, value_type
)
3900 != RETURN_VALUE_REGISTER_CONVENTION
);
3903 /* Set the initialized field in a value struct. */
3906 set_value_initialized (struct value
*val
, int status
)
3908 val
->initialized
= status
;
3911 /* Return the initialized field in a value struct. */
3914 value_initialized (const struct value
*val
)
3916 return val
->initialized
;
3919 /* Load the actual content of a lazy value. Fetch the data from the
3920 user's process and clear the lazy flag to indicate that the data in
3921 the buffer is valid.
3923 If the value is zero-length, we avoid calling read_memory, which
3924 would abort. We mark the value as fetched anyway -- all 0 bytes of
3928 value_fetch_lazy (struct value
*val
)
3930 gdb_assert (value_lazy (val
));
3931 allocate_value_contents (val
);
3932 /* A value is either lazy, or fully fetched. The
3933 availability/validity is only established as we try to fetch a
3935 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3936 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3937 if (value_bitsize (val
))
3939 /* To read a lazy bitfield, read the entire enclosing value. This
3940 prevents reading the same block of (possibly volatile) memory once
3941 per bitfield. It would be even better to read only the containing
3942 word, but we have no way to record that just specific bits of a
3943 value have been fetched. */
3944 struct type
*type
= check_typedef (value_type (val
));
3945 struct value
*parent
= value_parent (val
);
3947 if (value_lazy (parent
))
3948 value_fetch_lazy (parent
);
3950 unpack_value_bitfield (val
,
3951 value_bitpos (val
), value_bitsize (val
),
3952 value_contents_for_printing (parent
),
3953 value_offset (val
), parent
);
3955 else if (VALUE_LVAL (val
) == lval_memory
)
3957 CORE_ADDR addr
= value_address (val
);
3958 struct type
*type
= check_typedef (value_enclosing_type (val
));
3960 if (TYPE_LENGTH (type
))
3961 read_value_memory (val
, 0, value_stack (val
),
3962 addr
, value_contents_all_raw (val
),
3963 type_length_units (type
));
3965 else if (VALUE_LVAL (val
) == lval_register
)
3967 struct frame_info
*frame
;
3969 struct type
*type
= check_typedef (value_type (val
));
3970 struct value
*new_val
= val
, *mark
= value_mark ();
3972 /* Offsets are not supported here; lazy register values must
3973 refer to the entire register. */
3974 gdb_assert (value_offset (val
) == 0);
3976 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3978 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3980 frame
= frame_find_by_id (frame_id
);
3981 regnum
= VALUE_REGNUM (new_val
);
3983 gdb_assert (frame
!= NULL
);
3985 /* Convertible register routines are used for multi-register
3986 values and for interpretation in different types
3987 (e.g. float or int from a double register). Lazy
3988 register values should have the register's natural type,
3989 so they do not apply. */
3990 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3993 new_val
= get_frame_register_value (frame
, regnum
);
3995 /* If we get another lazy lval_register value, it means the
3996 register is found by reading it from the next frame.
3997 get_frame_register_value should never return a value with
3998 the frame id pointing to FRAME. If it does, it means we
3999 either have two consecutive frames with the same frame id
4000 in the frame chain, or some code is trying to unwind
4001 behind get_prev_frame's back (e.g., a frame unwind
4002 sniffer trying to unwind), bypassing its validations. In
4003 any case, it should always be an internal error to end up
4004 in this situation. */
4005 if (VALUE_LVAL (new_val
) == lval_register
4006 && value_lazy (new_val
)
4007 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
4008 internal_error (__FILE__
, __LINE__
,
4009 _("infinite loop while fetching a register"));
4012 /* If it's still lazy (for instance, a saved register on the
4013 stack), fetch it. */
4014 if (value_lazy (new_val
))
4015 value_fetch_lazy (new_val
);
4017 /* Copy the contents and the unavailability/optimized-out
4018 meta-data from NEW_VAL to VAL. */
4019 set_value_lazy (val
, 0);
4020 value_contents_copy (val
, value_embedded_offset (val
),
4021 new_val
, value_embedded_offset (new_val
),
4022 type_length_units (type
));
4026 struct gdbarch
*gdbarch
;
4027 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
4028 regnum
= VALUE_REGNUM (val
);
4029 gdbarch
= get_frame_arch (frame
);
4031 fprintf_unfiltered (gdb_stdlog
,
4032 "{ value_fetch_lazy "
4033 "(frame=%d,regnum=%d(%s),...) ",
4034 frame_relative_level (frame
), regnum
,
4035 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4037 fprintf_unfiltered (gdb_stdlog
, "->");
4038 if (value_optimized_out (new_val
))
4040 fprintf_unfiltered (gdb_stdlog
, " ");
4041 val_print_optimized_out (new_val
, gdb_stdlog
);
4046 const gdb_byte
*buf
= value_contents (new_val
);
4048 if (VALUE_LVAL (new_val
) == lval_register
)
4049 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4050 VALUE_REGNUM (new_val
));
4051 else if (VALUE_LVAL (new_val
) == lval_memory
)
4052 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4054 value_address (new_val
)));
4056 fprintf_unfiltered (gdb_stdlog
, " computed");
4058 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4059 fprintf_unfiltered (gdb_stdlog
, "[");
4060 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4061 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4062 fprintf_unfiltered (gdb_stdlog
, "]");
4065 fprintf_unfiltered (gdb_stdlog
, " }\n");
4068 /* Dispose of the intermediate values. This prevents
4069 watchpoints from trying to watch the saved frame pointer. */
4070 value_free_to_mark (mark
);
4072 else if (VALUE_LVAL (val
) == lval_computed
4073 && value_computed_funcs (val
)->read
!= NULL
)
4074 value_computed_funcs (val
)->read (val
);
4076 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4078 set_value_lazy (val
, 0);
4081 /* Implementation of the convenience function $_isvoid. */
4083 static struct value
*
4084 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4085 const struct language_defn
*language
,
4086 void *cookie
, int argc
, struct value
**argv
)
4091 error (_("You must provide one argument for $_isvoid."));
4093 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4095 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4099 _initialize_values (void)
4101 add_cmd ("convenience", no_class
, show_convenience
, _("\
4102 Debugger convenience (\"$foo\") variables and functions.\n\
4103 Convenience variables are created when you assign them values;\n\
4104 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4106 A few convenience variables are given values automatically:\n\
4107 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4108 \"$__\" holds the contents of the last address examined with \"x\"."
4111 Convenience functions are defined via the Python API."
4114 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4116 add_cmd ("values", no_set_class
, show_values
, _("\
4117 Elements of value history around item number IDX (or last ten)."),
4120 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4121 Initialize a convenience variable if necessary.\n\
4122 init-if-undefined VARIABLE = EXPRESSION\n\
4123 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4124 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4125 VARIABLE is already initialized."));
4127 add_prefix_cmd ("function", no_class
, function_command
, _("\
4128 Placeholder command for showing help on convenience functions."),
4129 &functionlist
, "function ", 0, &cmdlist
);
4131 add_internal_function ("_isvoid", _("\
4132 Check whether an expression is void.\n\
4133 Usage: $_isvoid (expression)\n\
4134 Return 1 if the expression is void, zero otherwise."),
4135 isvoid_internal_fn
, NULL
);
4137 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4138 class_support
, &max_value_size
, _("\
4139 Set maximum sized value gdb will load from the inferior."), _("\
4140 Show maximum sized value gdb will load from the inferior."), _("\
4141 Use this to control the maximum size, in bytes, of a value that gdb\n\
4142 will load from the inferior. Setting this value to 'unlimited'\n\
4143 disables checking.\n\
4144 Setting this does not invalidate already allocated values, it only\n\
4145 prevents future values, larger than this size, from being allocated."),
4147 show_max_value_size
,
4148 &setlist
, &showlist
);