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
;
1545 return value
->location
.address
+ value
->offset
;
1549 value_raw_address (const struct value
*value
)
1551 if (value
->lval
== lval_internalvar
1552 || value
->lval
== lval_internalvar_component
1553 || value
->lval
== lval_xcallable
)
1555 return value
->location
.address
;
1559 set_value_address (struct value
*value
, CORE_ADDR addr
)
1561 gdb_assert (value
->lval
!= lval_internalvar
1562 && value
->lval
!= lval_internalvar_component
1563 && value
->lval
!= lval_xcallable
);
1564 value
->location
.address
= addr
;
1567 struct internalvar
**
1568 deprecated_value_internalvar_hack (struct value
*value
)
1570 return &value
->location
.internalvar
;
1574 deprecated_value_frame_id_hack (struct value
*value
)
1576 return &value
->frame_id
;
1580 deprecated_value_regnum_hack (struct value
*value
)
1582 return &value
->regnum
;
1586 deprecated_value_modifiable (const struct value
*value
)
1588 return value
->modifiable
;
1591 /* Return a mark in the value chain. All values allocated after the
1592 mark is obtained (except for those released) are subject to being freed
1593 if a subsequent value_free_to_mark is passed the mark. */
1600 /* Take a reference to VAL. VAL will not be deallocated until all
1601 references are released. */
1604 value_incref (struct value
*val
)
1606 val
->reference_count
++;
1609 /* Release a reference to VAL, which was acquired with value_incref.
1610 This function is also called to deallocate values from the value
1614 value_free (struct value
*val
)
1618 gdb_assert (val
->reference_count
> 0);
1619 val
->reference_count
--;
1620 if (val
->reference_count
> 0)
1623 /* If there's an associated parent value, drop our reference to
1625 if (val
->parent
!= NULL
)
1626 value_free (val
->parent
);
1628 if (VALUE_LVAL (val
) == lval_computed
)
1630 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1632 if (funcs
->free_closure
)
1633 funcs
->free_closure (val
);
1635 else if (VALUE_LVAL (val
) == lval_xcallable
)
1636 free_xmethod_worker (val
->location
.xm_worker
);
1638 xfree (val
->contents
);
1639 VEC_free (range_s
, val
->unavailable
);
1644 /* Free all values allocated since MARK was obtained by value_mark
1645 (except for those released). */
1647 value_free_to_mark (const struct value
*mark
)
1652 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1661 /* Free all the values that have been allocated (except for those released).
1662 Call after each command, successful or not.
1663 In practice this is called before each command, which is sufficient. */
1666 free_all_values (void)
1671 for (val
= all_values
; val
; val
= next
)
1681 /* Frees all the elements in a chain of values. */
1684 free_value_chain (struct value
*v
)
1690 next
= value_next (v
);
1695 /* Remove VAL from the chain all_values
1696 so it will not be freed automatically. */
1699 release_value (struct value
*val
)
1703 if (all_values
== val
)
1705 all_values
= val
->next
;
1711 for (v
= all_values
; v
; v
= v
->next
)
1715 v
->next
= val
->next
;
1723 /* If the value is not already released, release it.
1724 If the value is already released, increment its reference count.
1725 That is, this function ensures that the value is released from the
1726 value chain and that the caller owns a reference to it. */
1729 release_value_or_incref (struct value
*val
)
1734 release_value (val
);
1737 /* Release all values up to mark */
1739 value_release_to_mark (const struct value
*mark
)
1744 for (val
= next
= all_values
; next
; next
= next
->next
)
1746 if (next
->next
== mark
)
1748 all_values
= next
->next
;
1758 /* Return a copy of the value ARG.
1759 It contains the same contents, for same memory address,
1760 but it's a different block of storage. */
1763 value_copy (struct value
*arg
)
1765 struct type
*encl_type
= value_enclosing_type (arg
);
1768 if (value_lazy (arg
))
1769 val
= allocate_value_lazy (encl_type
);
1771 val
= allocate_value (encl_type
);
1772 val
->type
= arg
->type
;
1773 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1774 val
->location
= arg
->location
;
1775 val
->offset
= arg
->offset
;
1776 val
->bitpos
= arg
->bitpos
;
1777 val
->bitsize
= arg
->bitsize
;
1778 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1779 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1780 val
->lazy
= arg
->lazy
;
1781 val
->embedded_offset
= value_embedded_offset (arg
);
1782 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1783 val
->modifiable
= arg
->modifiable
;
1784 if (!value_lazy (val
))
1786 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1787 TYPE_LENGTH (value_enclosing_type (arg
)));
1790 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1791 val
->optimized_out
= VEC_copy (range_s
, arg
->optimized_out
);
1792 set_value_parent (val
, arg
->parent
);
1793 if (VALUE_LVAL (val
) == lval_computed
)
1795 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1797 if (funcs
->copy_closure
)
1798 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1803 /* Return a "const" and/or "volatile" qualified version of the value V.
1804 If CNST is true, then the returned value will be qualified with
1806 if VOLTL is true, then the returned value will be qualified with
1810 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1812 struct type
*val_type
= value_type (v
);
1813 struct type
*enclosing_type
= value_enclosing_type (v
);
1814 struct value
*cv_val
= value_copy (v
);
1816 deprecated_set_value_type (cv_val
,
1817 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1818 set_value_enclosing_type (cv_val
,
1819 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1824 /* Return a version of ARG that is non-lvalue. */
1827 value_non_lval (struct value
*arg
)
1829 if (VALUE_LVAL (arg
) != not_lval
)
1831 struct type
*enc_type
= value_enclosing_type (arg
);
1832 struct value
*val
= allocate_value (enc_type
);
1834 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1835 TYPE_LENGTH (enc_type
));
1836 val
->type
= arg
->type
;
1837 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1838 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1844 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1847 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1849 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1851 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1852 v
->lval
= lval_memory
;
1853 v
->location
.address
= addr
;
1857 set_value_component_location (struct value
*component
,
1858 const struct value
*whole
)
1860 gdb_assert (whole
->lval
!= lval_xcallable
);
1862 if (whole
->lval
== lval_internalvar
)
1863 VALUE_LVAL (component
) = lval_internalvar_component
;
1865 VALUE_LVAL (component
) = whole
->lval
;
1867 component
->location
= whole
->location
;
1868 if (whole
->lval
== lval_computed
)
1870 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1872 if (funcs
->copy_closure
)
1873 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1878 /* Access to the value history. */
1880 /* Record a new value in the value history.
1881 Returns the absolute history index of the entry. */
1884 record_latest_value (struct value
*val
)
1888 /* We don't want this value to have anything to do with the inferior anymore.
1889 In particular, "set $1 = 50" should not affect the variable from which
1890 the value was taken, and fast watchpoints should be able to assume that
1891 a value on the value history never changes. */
1892 if (value_lazy (val
))
1893 value_fetch_lazy (val
);
1894 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1895 from. This is a bit dubious, because then *&$1 does not just return $1
1896 but the current contents of that location. c'est la vie... */
1897 val
->modifiable
= 0;
1899 /* The value may have already been released, in which case we're adding a
1900 new reference for its entry in the history. That is why we call
1901 release_value_or_incref here instead of release_value. */
1902 release_value_or_incref (val
);
1904 /* Here we treat value_history_count as origin-zero
1905 and applying to the value being stored now. */
1907 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1910 struct value_history_chunk
*newobj
= XCNEW (struct value_history_chunk
);
1912 newobj
->next
= value_history_chain
;
1913 value_history_chain
= newobj
;
1916 value_history_chain
->values
[i
] = val
;
1918 /* Now we regard value_history_count as origin-one
1919 and applying to the value just stored. */
1921 return ++value_history_count
;
1924 /* Return a copy of the value in the history with sequence number NUM. */
1927 access_value_history (int num
)
1929 struct value_history_chunk
*chunk
;
1934 absnum
+= value_history_count
;
1939 error (_("The history is empty."));
1941 error (_("There is only one value in the history."));
1943 error (_("History does not go back to $$%d."), -num
);
1945 if (absnum
> value_history_count
)
1946 error (_("History has not yet reached $%d."), absnum
);
1950 /* Now absnum is always absolute and origin zero. */
1952 chunk
= value_history_chain
;
1953 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1954 - absnum
/ VALUE_HISTORY_CHUNK
;
1956 chunk
= chunk
->next
;
1958 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1962 show_values (char *num_exp
, int from_tty
)
1970 /* "show values +" should print from the stored position.
1971 "show values <exp>" should print around value number <exp>. */
1972 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1973 num
= parse_and_eval_long (num_exp
) - 5;
1977 /* "show values" means print the last 10 values. */
1978 num
= value_history_count
- 9;
1984 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1986 struct value_print_options opts
;
1988 val
= access_value_history (i
);
1989 printf_filtered (("$%d = "), i
);
1990 get_user_print_options (&opts
);
1991 value_print (val
, gdb_stdout
, &opts
);
1992 printf_filtered (("\n"));
1995 /* The next "show values +" should start after what we just printed. */
1998 /* Hitting just return after this command should do the same thing as
1999 "show values +". If num_exp is null, this is unnecessary, since
2000 "show values +" is not useful after "show values". */
2001 if (from_tty
&& num_exp
)
2008 enum internalvar_kind
2010 /* The internal variable is empty. */
2013 /* The value of the internal variable is provided directly as
2014 a GDB value object. */
2017 /* A fresh value is computed via a call-back routine on every
2018 access to the internal variable. */
2019 INTERNALVAR_MAKE_VALUE
,
2021 /* The internal variable holds a GDB internal convenience function. */
2022 INTERNALVAR_FUNCTION
,
2024 /* The variable holds an integer value. */
2025 INTERNALVAR_INTEGER
,
2027 /* The variable holds a GDB-provided string. */
2031 union internalvar_data
2033 /* A value object used with INTERNALVAR_VALUE. */
2034 struct value
*value
;
2036 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2039 /* The functions to call. */
2040 const struct internalvar_funcs
*functions
;
2042 /* The function's user-data. */
2046 /* The internal function used with INTERNALVAR_FUNCTION. */
2049 struct internal_function
*function
;
2050 /* True if this is the canonical name for the function. */
2054 /* An integer value used with INTERNALVAR_INTEGER. */
2057 /* If type is non-NULL, it will be used as the type to generate
2058 a value for this internal variable. If type is NULL, a default
2059 integer type for the architecture is used. */
2064 /* A string value used with INTERNALVAR_STRING. */
2068 /* Internal variables. These are variables within the debugger
2069 that hold values assigned by debugger commands.
2070 The user refers to them with a '$' prefix
2071 that does not appear in the variable names stored internally. */
2075 struct internalvar
*next
;
2078 /* We support various different kinds of content of an internal variable.
2079 enum internalvar_kind specifies the kind, and union internalvar_data
2080 provides the data associated with this particular kind. */
2082 enum internalvar_kind kind
;
2084 union internalvar_data u
;
2087 static struct internalvar
*internalvars
;
2089 /* If the variable does not already exist create it and give it the
2090 value given. If no value is given then the default is zero. */
2092 init_if_undefined_command (char* args
, int from_tty
)
2094 struct internalvar
* intvar
;
2096 /* Parse the expression - this is taken from set_command(). */
2097 struct expression
*expr
= parse_expression (args
);
2098 register struct cleanup
*old_chain
=
2099 make_cleanup (free_current_contents
, &expr
);
2101 /* Validate the expression.
2102 Was the expression an assignment?
2103 Or even an expression at all? */
2104 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
2105 error (_("Init-if-undefined requires an assignment expression."));
2107 /* Extract the variable from the parsed expression.
2108 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2109 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
2110 error (_("The first parameter to init-if-undefined "
2111 "should be a GDB variable."));
2112 intvar
= expr
->elts
[2].internalvar
;
2114 /* Only evaluate the expression if the lvalue is void.
2115 This may still fail if the expresssion is invalid. */
2116 if (intvar
->kind
== INTERNALVAR_VOID
)
2117 evaluate_expression (expr
);
2119 do_cleanups (old_chain
);
2123 /* Look up an internal variable with name NAME. NAME should not
2124 normally include a dollar sign.
2126 If the specified internal variable does not exist,
2127 the return value is NULL. */
2129 struct internalvar
*
2130 lookup_only_internalvar (const char *name
)
2132 struct internalvar
*var
;
2134 for (var
= internalvars
; var
; var
= var
->next
)
2135 if (strcmp (var
->name
, name
) == 0)
2141 /* Complete NAME by comparing it to the names of internal variables.
2142 Returns a vector of newly allocated strings, or NULL if no matches
2146 complete_internalvar (const char *name
)
2148 VEC (char_ptr
) *result
= NULL
;
2149 struct internalvar
*var
;
2152 len
= strlen (name
);
2154 for (var
= internalvars
; var
; var
= var
->next
)
2155 if (strncmp (var
->name
, name
, len
) == 0)
2157 char *r
= xstrdup (var
->name
);
2159 VEC_safe_push (char_ptr
, result
, r
);
2165 /* Create an internal variable with name NAME and with a void value.
2166 NAME should not normally include a dollar sign. */
2168 struct internalvar
*
2169 create_internalvar (const char *name
)
2171 struct internalvar
*var
= XNEW (struct internalvar
);
2173 var
->name
= concat (name
, (char *)NULL
);
2174 var
->kind
= INTERNALVAR_VOID
;
2175 var
->next
= internalvars
;
2180 /* Create an internal variable with name NAME and register FUN as the
2181 function that value_of_internalvar uses to create a value whenever
2182 this variable is referenced. NAME should not normally include a
2183 dollar sign. DATA is passed uninterpreted to FUN when it is
2184 called. CLEANUP, if not NULL, is called when the internal variable
2185 is destroyed. It is passed DATA as its only argument. */
2187 struct internalvar
*
2188 create_internalvar_type_lazy (const char *name
,
2189 const struct internalvar_funcs
*funcs
,
2192 struct internalvar
*var
= create_internalvar (name
);
2194 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2195 var
->u
.make_value
.functions
= funcs
;
2196 var
->u
.make_value
.data
= data
;
2200 /* See documentation in value.h. */
2203 compile_internalvar_to_ax (struct internalvar
*var
,
2204 struct agent_expr
*expr
,
2205 struct axs_value
*value
)
2207 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2208 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2211 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2212 var
->u
.make_value
.data
);
2216 /* Look up an internal variable with name NAME. NAME should not
2217 normally include a dollar sign.
2219 If the specified internal variable does not exist,
2220 one is created, with a void value. */
2222 struct internalvar
*
2223 lookup_internalvar (const char *name
)
2225 struct internalvar
*var
;
2227 var
= lookup_only_internalvar (name
);
2231 return create_internalvar (name
);
2234 /* Return current value of internal variable VAR. For variables that
2235 are not inherently typed, use a value type appropriate for GDBARCH. */
2238 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2241 struct trace_state_variable
*tsv
;
2243 /* If there is a trace state variable of the same name, assume that
2244 is what we really want to see. */
2245 tsv
= find_trace_state_variable (var
->name
);
2248 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2250 if (tsv
->value_known
)
2251 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2254 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2260 case INTERNALVAR_VOID
:
2261 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2264 case INTERNALVAR_FUNCTION
:
2265 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2268 case INTERNALVAR_INTEGER
:
2269 if (!var
->u
.integer
.type
)
2270 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2271 var
->u
.integer
.val
);
2273 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2276 case INTERNALVAR_STRING
:
2277 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2278 builtin_type (gdbarch
)->builtin_char
);
2281 case INTERNALVAR_VALUE
:
2282 val
= value_copy (var
->u
.value
);
2283 if (value_lazy (val
))
2284 value_fetch_lazy (val
);
2287 case INTERNALVAR_MAKE_VALUE
:
2288 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2289 var
->u
.make_value
.data
);
2293 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2296 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2297 on this value go back to affect the original internal variable.
2299 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2300 no underlying modifyable state in the internal variable.
2302 Likewise, if the variable's value is a computed lvalue, we want
2303 references to it to produce another computed lvalue, where
2304 references and assignments actually operate through the
2305 computed value's functions.
2307 This means that internal variables with computed values
2308 behave a little differently from other internal variables:
2309 assignments to them don't just replace the previous value
2310 altogether. At the moment, this seems like the behavior we
2313 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2314 && val
->lval
!= lval_computed
)
2316 VALUE_LVAL (val
) = lval_internalvar
;
2317 VALUE_INTERNALVAR (val
) = var
;
2324 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2326 if (var
->kind
== INTERNALVAR_INTEGER
)
2328 *result
= var
->u
.integer
.val
;
2332 if (var
->kind
== INTERNALVAR_VALUE
)
2334 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2336 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2338 *result
= value_as_long (var
->u
.value
);
2347 get_internalvar_function (struct internalvar
*var
,
2348 struct internal_function
**result
)
2352 case INTERNALVAR_FUNCTION
:
2353 *result
= var
->u
.fn
.function
;
2362 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
2363 int bitsize
, struct value
*newval
)
2366 struct gdbarch
*arch
;
2371 case INTERNALVAR_VALUE
:
2372 addr
= value_contents_writeable (var
->u
.value
);
2373 arch
= get_value_arch (var
->u
.value
);
2374 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2377 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2378 value_as_long (newval
), bitpos
, bitsize
);
2380 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2381 TYPE_LENGTH (value_type (newval
)));
2385 /* We can never get a component of any other kind. */
2386 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2391 set_internalvar (struct internalvar
*var
, struct value
*val
)
2393 enum internalvar_kind new_kind
;
2394 union internalvar_data new_data
= { 0 };
2396 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2397 error (_("Cannot overwrite convenience function %s"), var
->name
);
2399 /* Prepare new contents. */
2400 switch (TYPE_CODE (check_typedef (value_type (val
))))
2402 case TYPE_CODE_VOID
:
2403 new_kind
= INTERNALVAR_VOID
;
2406 case TYPE_CODE_INTERNAL_FUNCTION
:
2407 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2408 new_kind
= INTERNALVAR_FUNCTION
;
2409 get_internalvar_function (VALUE_INTERNALVAR (val
),
2410 &new_data
.fn
.function
);
2411 /* Copies created here are never canonical. */
2415 new_kind
= INTERNALVAR_VALUE
;
2416 new_data
.value
= value_copy (val
);
2417 new_data
.value
->modifiable
= 1;
2419 /* Force the value to be fetched from the target now, to avoid problems
2420 later when this internalvar is referenced and the target is gone or
2422 if (value_lazy (new_data
.value
))
2423 value_fetch_lazy (new_data
.value
);
2425 /* Release the value from the value chain to prevent it from being
2426 deleted by free_all_values. From here on this function should not
2427 call error () until new_data is installed into the var->u to avoid
2429 release_value (new_data
.value
);
2433 /* Clean up old contents. */
2434 clear_internalvar (var
);
2437 var
->kind
= new_kind
;
2439 /* End code which must not call error(). */
2443 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2445 /* Clean up old contents. */
2446 clear_internalvar (var
);
2448 var
->kind
= INTERNALVAR_INTEGER
;
2449 var
->u
.integer
.type
= NULL
;
2450 var
->u
.integer
.val
= l
;
2454 set_internalvar_string (struct internalvar
*var
, const char *string
)
2456 /* Clean up old contents. */
2457 clear_internalvar (var
);
2459 var
->kind
= INTERNALVAR_STRING
;
2460 var
->u
.string
= xstrdup (string
);
2464 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2466 /* Clean up old contents. */
2467 clear_internalvar (var
);
2469 var
->kind
= INTERNALVAR_FUNCTION
;
2470 var
->u
.fn
.function
= f
;
2471 var
->u
.fn
.canonical
= 1;
2472 /* Variables installed here are always the canonical version. */
2476 clear_internalvar (struct internalvar
*var
)
2478 /* Clean up old contents. */
2481 case INTERNALVAR_VALUE
:
2482 value_free (var
->u
.value
);
2485 case INTERNALVAR_STRING
:
2486 xfree (var
->u
.string
);
2489 case INTERNALVAR_MAKE_VALUE
:
2490 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2491 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2498 /* Reset to void kind. */
2499 var
->kind
= INTERNALVAR_VOID
;
2503 internalvar_name (const struct internalvar
*var
)
2508 static struct internal_function
*
2509 create_internal_function (const char *name
,
2510 internal_function_fn handler
, void *cookie
)
2512 struct internal_function
*ifn
= XNEW (struct internal_function
);
2514 ifn
->name
= xstrdup (name
);
2515 ifn
->handler
= handler
;
2516 ifn
->cookie
= cookie
;
2521 value_internal_function_name (struct value
*val
)
2523 struct internal_function
*ifn
;
2526 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2527 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2528 gdb_assert (result
);
2534 call_internal_function (struct gdbarch
*gdbarch
,
2535 const struct language_defn
*language
,
2536 struct value
*func
, int argc
, struct value
**argv
)
2538 struct internal_function
*ifn
;
2541 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2542 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2543 gdb_assert (result
);
2545 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2548 /* The 'function' command. This does nothing -- it is just a
2549 placeholder to let "help function NAME" work. This is also used as
2550 the implementation of the sub-command that is created when
2551 registering an internal function. */
2553 function_command (char *command
, int from_tty
)
2558 /* Clean up if an internal function's command is destroyed. */
2560 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2562 xfree ((char *) self
->name
);
2563 xfree ((char *) self
->doc
);
2566 /* Add a new internal function. NAME is the name of the function; DOC
2567 is a documentation string describing the function. HANDLER is
2568 called when the function is invoked. COOKIE is an arbitrary
2569 pointer which is passed to HANDLER and is intended for "user
2572 add_internal_function (const char *name
, const char *doc
,
2573 internal_function_fn handler
, void *cookie
)
2575 struct cmd_list_element
*cmd
;
2576 struct internal_function
*ifn
;
2577 struct internalvar
*var
= lookup_internalvar (name
);
2579 ifn
= create_internal_function (name
, handler
, cookie
);
2580 set_internalvar_function (var
, ifn
);
2582 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2584 cmd
->destroyer
= function_destroyer
;
2587 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2588 prevent cycles / duplicates. */
2591 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2592 htab_t copied_types
)
2594 if (TYPE_OBJFILE (value
->type
) == objfile
)
2595 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2597 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2598 value
->enclosing_type
= copy_type_recursive (objfile
,
2599 value
->enclosing_type
,
2603 /* Likewise for internal variable VAR. */
2606 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2607 htab_t copied_types
)
2611 case INTERNALVAR_INTEGER
:
2612 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2614 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2617 case INTERNALVAR_VALUE
:
2618 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2623 /* Update the internal variables and value history when OBJFILE is
2624 discarded; we must copy the types out of the objfile. New global types
2625 will be created for every convenience variable which currently points to
2626 this objfile's types, and the convenience variables will be adjusted to
2627 use the new global types. */
2630 preserve_values (struct objfile
*objfile
)
2632 htab_t copied_types
;
2633 struct value_history_chunk
*cur
;
2634 struct internalvar
*var
;
2637 /* Create the hash table. We allocate on the objfile's obstack, since
2638 it is soon to be deleted. */
2639 copied_types
= create_copied_types_hash (objfile
);
2641 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2642 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2644 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2646 for (var
= internalvars
; var
; var
= var
->next
)
2647 preserve_one_internalvar (var
, objfile
, copied_types
);
2649 preserve_ext_lang_values (objfile
, copied_types
);
2651 htab_delete (copied_types
);
2655 show_convenience (char *ignore
, int from_tty
)
2657 struct gdbarch
*gdbarch
= get_current_arch ();
2658 struct internalvar
*var
;
2660 struct value_print_options opts
;
2662 get_user_print_options (&opts
);
2663 for (var
= internalvars
; var
; var
= var
->next
)
2670 printf_filtered (("$%s = "), var
->name
);
2676 val
= value_of_internalvar (gdbarch
, var
);
2677 value_print (val
, gdb_stdout
, &opts
);
2679 CATCH (ex
, RETURN_MASK_ERROR
)
2681 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2685 printf_filtered (("\n"));
2689 /* This text does not mention convenience functions on purpose.
2690 The user can't create them except via Python, and if Python support
2691 is installed this message will never be printed ($_streq will
2693 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2694 "Convenience variables have "
2695 "names starting with \"$\";\n"
2696 "use \"set\" as in \"set "
2697 "$foo = 5\" to define them.\n"));
2701 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2704 value_of_xmethod (struct xmethod_worker
*worker
)
2706 if (worker
->value
== NULL
)
2710 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2711 v
->lval
= lval_xcallable
;
2712 v
->location
.xm_worker
= worker
;
2717 return worker
->value
;
2720 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2723 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2725 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2726 && method
->lval
== lval_xcallable
&& argc
> 0);
2728 return get_xmethod_result_type (method
->location
.xm_worker
,
2729 argv
[0], argv
+ 1, argc
- 1);
2732 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2735 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2737 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2738 && method
->lval
== lval_xcallable
&& argc
> 0);
2740 return invoke_xmethod (method
->location
.xm_worker
,
2741 argv
[0], argv
+ 1, argc
- 1);
2744 /* Extract a value as a C number (either long or double).
2745 Knows how to convert fixed values to double, or
2746 floating values to long.
2747 Does not deallocate the value. */
2750 value_as_long (struct value
*val
)
2752 /* This coerces arrays and functions, which is necessary (e.g.
2753 in disassemble_command). It also dereferences references, which
2754 I suspect is the most logical thing to do. */
2755 val
= coerce_array (val
);
2756 return unpack_long (value_type (val
), value_contents (val
));
2760 value_as_double (struct value
*val
)
2765 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2767 error (_("Invalid floating value found in program."));
2771 /* Extract a value as a C pointer. Does not deallocate the value.
2772 Note that val's type may not actually be a pointer; value_as_long
2773 handles all the cases. */
2775 value_as_address (struct value
*val
)
2777 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2779 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2780 whether we want this to be true eventually. */
2782 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2783 non-address (e.g. argument to "signal", "info break", etc.), or
2784 for pointers to char, in which the low bits *are* significant. */
2785 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2788 /* There are several targets (IA-64, PowerPC, and others) which
2789 don't represent pointers to functions as simply the address of
2790 the function's entry point. For example, on the IA-64, a
2791 function pointer points to a two-word descriptor, generated by
2792 the linker, which contains the function's entry point, and the
2793 value the IA-64 "global pointer" register should have --- to
2794 support position-independent code. The linker generates
2795 descriptors only for those functions whose addresses are taken.
2797 On such targets, it's difficult for GDB to convert an arbitrary
2798 function address into a function pointer; it has to either find
2799 an existing descriptor for that function, or call malloc and
2800 build its own. On some targets, it is impossible for GDB to
2801 build a descriptor at all: the descriptor must contain a jump
2802 instruction; data memory cannot be executed; and code memory
2805 Upon entry to this function, if VAL is a value of type `function'
2806 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2807 value_address (val) is the address of the function. This is what
2808 you'll get if you evaluate an expression like `main'. The call
2809 to COERCE_ARRAY below actually does all the usual unary
2810 conversions, which includes converting values of type `function'
2811 to `pointer to function'. This is the challenging conversion
2812 discussed above. Then, `unpack_long' will convert that pointer
2813 back into an address.
2815 So, suppose the user types `disassemble foo' on an architecture
2816 with a strange function pointer representation, on which GDB
2817 cannot build its own descriptors, and suppose further that `foo'
2818 has no linker-built descriptor. The address->pointer conversion
2819 will signal an error and prevent the command from running, even
2820 though the next step would have been to convert the pointer
2821 directly back into the same address.
2823 The following shortcut avoids this whole mess. If VAL is a
2824 function, just return its address directly. */
2825 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2826 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2827 return value_address (val
);
2829 val
= coerce_array (val
);
2831 /* Some architectures (e.g. Harvard), map instruction and data
2832 addresses onto a single large unified address space. For
2833 instance: An architecture may consider a large integer in the
2834 range 0x10000000 .. 0x1000ffff to already represent a data
2835 addresses (hence not need a pointer to address conversion) while
2836 a small integer would still need to be converted integer to
2837 pointer to address. Just assume such architectures handle all
2838 integer conversions in a single function. */
2842 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2843 must admonish GDB hackers to make sure its behavior matches the
2844 compiler's, whenever possible.
2846 In general, I think GDB should evaluate expressions the same way
2847 the compiler does. When the user copies an expression out of
2848 their source code and hands it to a `print' command, they should
2849 get the same value the compiler would have computed. Any
2850 deviation from this rule can cause major confusion and annoyance,
2851 and needs to be justified carefully. In other words, GDB doesn't
2852 really have the freedom to do these conversions in clever and
2855 AndrewC pointed out that users aren't complaining about how GDB
2856 casts integers to pointers; they are complaining that they can't
2857 take an address from a disassembly listing and give it to `x/i'.
2858 This is certainly important.
2860 Adding an architecture method like integer_to_address() certainly
2861 makes it possible for GDB to "get it right" in all circumstances
2862 --- the target has complete control over how things get done, so
2863 people can Do The Right Thing for their target without breaking
2864 anyone else. The standard doesn't specify how integers get
2865 converted to pointers; usually, the ABI doesn't either, but
2866 ABI-specific code is a more reasonable place to handle it. */
2868 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2869 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2870 && gdbarch_integer_to_address_p (gdbarch
))
2871 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2872 value_contents (val
));
2874 return unpack_long (value_type (val
), value_contents (val
));
2878 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2879 as a long, or as a double, assuming the raw data is described
2880 by type TYPE. Knows how to convert different sizes of values
2881 and can convert between fixed and floating point. We don't assume
2882 any alignment for the raw data. Return value is in host byte order.
2884 If you want functions and arrays to be coerced to pointers, and
2885 references to be dereferenced, call value_as_long() instead.
2887 C++: It is assumed that the front-end has taken care of
2888 all matters concerning pointers to members. A pointer
2889 to member which reaches here is considered to be equivalent
2890 to an INT (or some size). After all, it is only an offset. */
2893 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2895 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2896 enum type_code code
= TYPE_CODE (type
);
2897 int len
= TYPE_LENGTH (type
);
2898 int nosign
= TYPE_UNSIGNED (type
);
2902 case TYPE_CODE_TYPEDEF
:
2903 return unpack_long (check_typedef (type
), valaddr
);
2904 case TYPE_CODE_ENUM
:
2905 case TYPE_CODE_FLAGS
:
2906 case TYPE_CODE_BOOL
:
2908 case TYPE_CODE_CHAR
:
2909 case TYPE_CODE_RANGE
:
2910 case TYPE_CODE_MEMBERPTR
:
2912 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2914 return extract_signed_integer (valaddr
, len
, byte_order
);
2917 return (LONGEST
) extract_typed_floating (valaddr
, type
);
2919 case TYPE_CODE_DECFLOAT
:
2920 /* libdecnumber has a function to convert from decimal to integer, but
2921 it doesn't work when the decimal number has a fractional part. */
2922 return (LONGEST
) decimal_to_doublest (valaddr
, len
, byte_order
);
2926 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2927 whether we want this to be true eventually. */
2928 return extract_typed_address (valaddr
, type
);
2931 error (_("Value can't be converted to integer."));
2933 return 0; /* Placate lint. */
2936 /* Return a double value from the specified type and address.
2937 INVP points to an int which is set to 0 for valid value,
2938 1 for invalid value (bad float format). In either case,
2939 the returned double is OK to use. Argument is in target
2940 format, result is in host format. */
2943 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2945 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2946 enum type_code code
;
2950 *invp
= 0; /* Assume valid. */
2951 type
= check_typedef (type
);
2952 code
= TYPE_CODE (type
);
2953 len
= TYPE_LENGTH (type
);
2954 nosign
= TYPE_UNSIGNED (type
);
2955 if (code
== TYPE_CODE_FLT
)
2957 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2958 floating-point value was valid (using the macro
2959 INVALID_FLOAT). That test/macro have been removed.
2961 It turns out that only the VAX defined this macro and then
2962 only in a non-portable way. Fixing the portability problem
2963 wouldn't help since the VAX floating-point code is also badly
2964 bit-rotten. The target needs to add definitions for the
2965 methods gdbarch_float_format and gdbarch_double_format - these
2966 exactly describe the target floating-point format. The
2967 problem here is that the corresponding floatformat_vax_f and
2968 floatformat_vax_d values these methods should be set to are
2969 also not defined either. Oops!
2971 Hopefully someone will add both the missing floatformat
2972 definitions and the new cases for floatformat_is_valid (). */
2974 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2980 return extract_typed_floating (valaddr
, type
);
2982 else if (code
== TYPE_CODE_DECFLOAT
)
2983 return decimal_to_doublest (valaddr
, len
, byte_order
);
2986 /* Unsigned -- be sure we compensate for signed LONGEST. */
2987 return (ULONGEST
) unpack_long (type
, valaddr
);
2991 /* Signed -- we are OK with unpack_long. */
2992 return unpack_long (type
, valaddr
);
2996 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2997 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2998 We don't assume any alignment for the raw data. Return value is in
3001 If you want functions and arrays to be coerced to pointers, and
3002 references to be dereferenced, call value_as_address() instead.
3004 C++: It is assumed that the front-end has taken care of
3005 all matters concerning pointers to members. A pointer
3006 to member which reaches here is considered to be equivalent
3007 to an INT (or some size). After all, it is only an offset. */
3010 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
3012 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3013 whether we want this to be true eventually. */
3014 return unpack_long (type
, valaddr
);
3018 /* Get the value of the FIELDNO'th field (which must be static) of
3022 value_static_field (struct type
*type
, int fieldno
)
3024 struct value
*retval
;
3026 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
3028 case FIELD_LOC_KIND_PHYSADDR
:
3029 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3030 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
3032 case FIELD_LOC_KIND_PHYSNAME
:
3034 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
3035 /* TYPE_FIELD_NAME (type, fieldno); */
3036 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
3038 if (sym
.symbol
== NULL
)
3040 /* With some compilers, e.g. HP aCC, static data members are
3041 reported as non-debuggable symbols. */
3042 struct bound_minimal_symbol msym
3043 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
3046 return allocate_optimized_out_value (type
);
3049 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
3050 BMSYMBOL_VALUE_ADDRESS (msym
));
3054 retval
= value_of_variable (sym
.symbol
, sym
.block
);
3058 gdb_assert_not_reached ("unexpected field location kind");
3064 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3065 You have to be careful here, since the size of the data area for the value
3066 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3067 than the old enclosing type, you have to allocate more space for the
3071 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
3073 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
3075 check_type_length_before_alloc (new_encl_type
);
3077 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
3080 val
->enclosing_type
= new_encl_type
;
3083 /* Given a value ARG1 (offset by OFFSET bytes)
3084 of a struct or union type ARG_TYPE,
3085 extract and return the value of one of its (non-static) fields.
3086 FIELDNO says which field. */
3089 value_primitive_field (struct value
*arg1
, int offset
,
3090 int fieldno
, struct type
*arg_type
)
3094 struct gdbarch
*arch
= get_value_arch (arg1
);
3095 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
3097 arg_type
= check_typedef (arg_type
);
3098 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
3100 /* Call check_typedef on our type to make sure that, if TYPE
3101 is a TYPE_CODE_TYPEDEF, its length is set to the length
3102 of the target type instead of zero. However, we do not
3103 replace the typedef type by the target type, because we want
3104 to keep the typedef in order to be able to print the type
3105 description correctly. */
3106 check_typedef (type
);
3108 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
3110 /* Handle packed fields.
3112 Create a new value for the bitfield, with bitpos and bitsize
3113 set. If possible, arrange offset and bitpos so that we can
3114 do a single aligned read of the size of the containing type.
3115 Otherwise, adjust offset to the byte containing the first
3116 bit. Assume that the address, offset, and embedded offset
3117 are sufficiently aligned. */
3119 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
3120 int container_bitsize
= TYPE_LENGTH (type
) * 8;
3122 v
= allocate_value_lazy (type
);
3123 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
3124 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
3125 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
3126 v
->bitpos
= bitpos
% container_bitsize
;
3128 v
->bitpos
= bitpos
% 8;
3129 v
->offset
= (value_embedded_offset (arg1
)
3131 + (bitpos
- v
->bitpos
) / 8);
3132 set_value_parent (v
, arg1
);
3133 if (!value_lazy (arg1
))
3134 value_fetch_lazy (v
);
3136 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
3138 /* This field is actually a base subobject, so preserve the
3139 entire object's contents for later references to virtual
3143 /* Lazy register values with offsets are not supported. */
3144 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3145 value_fetch_lazy (arg1
);
3147 /* We special case virtual inheritance here because this
3148 requires access to the contents, which we would rather avoid
3149 for references to ordinary fields of unavailable values. */
3150 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
3151 boffset
= baseclass_offset (arg_type
, fieldno
,
3152 value_contents (arg1
),
3153 value_embedded_offset (arg1
),
3154 value_address (arg1
),
3157 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
3159 if (value_lazy (arg1
))
3160 v
= allocate_value_lazy (value_enclosing_type (arg1
));
3163 v
= allocate_value (value_enclosing_type (arg1
));
3164 value_contents_copy_raw (v
, 0, arg1
, 0,
3165 TYPE_LENGTH (value_enclosing_type (arg1
)));
3168 v
->offset
= value_offset (arg1
);
3169 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
3173 /* Plain old data member */
3174 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
3175 / (HOST_CHAR_BIT
* unit_size
));
3177 /* Lazy register values with offsets are not supported. */
3178 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
3179 value_fetch_lazy (arg1
);
3181 if (value_lazy (arg1
))
3182 v
= allocate_value_lazy (type
);
3185 v
= allocate_value (type
);
3186 value_contents_copy_raw (v
, value_embedded_offset (v
),
3187 arg1
, value_embedded_offset (arg1
) + offset
,
3188 type_length_units (type
));
3190 v
->offset
= (value_offset (arg1
) + offset
3191 + value_embedded_offset (arg1
));
3193 set_value_component_location (v
, arg1
);
3194 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
3195 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
3199 /* Given a value ARG1 of a struct or union type,
3200 extract and return the value of one of its (non-static) fields.
3201 FIELDNO says which field. */
3204 value_field (struct value
*arg1
, int fieldno
)
3206 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3209 /* Return a non-virtual function as a value.
3210 F is the list of member functions which contains the desired method.
3211 J is an index into F which provides the desired method.
3213 We only use the symbol for its address, so be happy with either a
3214 full symbol or a minimal symbol. */
3217 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3218 int j
, struct type
*type
,
3222 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3223 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3225 struct bound_minimal_symbol msym
;
3227 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3230 memset (&msym
, 0, sizeof (msym
));
3234 gdb_assert (sym
== NULL
);
3235 msym
= lookup_bound_minimal_symbol (physname
);
3236 if (msym
.minsym
== NULL
)
3240 v
= allocate_value (ftype
);
3243 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3247 /* The minimal symbol might point to a function descriptor;
3248 resolve it to the actual code address instead. */
3249 struct objfile
*objfile
= msym
.objfile
;
3250 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3252 set_value_address (v
,
3253 gdbarch_convert_from_func_ptr_addr
3254 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3259 if (type
!= value_type (*arg1p
))
3260 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3261 value_addr (*arg1p
)));
3263 /* Move the `this' pointer according to the offset.
3264 VALUE_OFFSET (*arg1p) += offset; */
3272 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3273 VALADDR, and store the result in *RESULT.
3274 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3276 Extracting bits depends on endianness of the machine. Compute the
3277 number of least significant bits to discard. For big endian machines,
3278 we compute the total number of bits in the anonymous object, subtract
3279 off the bit count from the MSB of the object to the MSB of the
3280 bitfield, then the size of the bitfield, which leaves the LSB discard
3281 count. For little endian machines, the discard count is simply the
3282 number of bits from the LSB of the anonymous object to the LSB of the
3285 If the field is signed, we also do sign extension. */
3288 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3289 int bitpos
, int bitsize
)
3291 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3298 /* Read the minimum number of bytes required; there may not be
3299 enough bytes to read an entire ULONGEST. */
3300 field_type
= check_typedef (field_type
);
3302 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3304 bytes_read
= TYPE_LENGTH (field_type
);
3306 read_offset
= bitpos
/ 8;
3308 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3309 bytes_read
, byte_order
);
3311 /* Extract bits. See comment above. */
3313 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3314 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3316 lsbcount
= (bitpos
% 8);
3319 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3320 If the field is signed, and is negative, then sign extend. */
3322 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3324 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3326 if (!TYPE_UNSIGNED (field_type
))
3328 if (val
& (valmask
^ (valmask
>> 1)))
3338 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3339 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3340 ORIGINAL_VALUE, which must not be NULL. See
3341 unpack_value_bits_as_long for more details. */
3344 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3345 int embedded_offset
, int fieldno
,
3346 const struct value
*val
, LONGEST
*result
)
3348 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3349 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3350 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3353 gdb_assert (val
!= NULL
);
3355 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3356 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3357 || !value_bits_available (val
, bit_offset
, bitsize
))
3360 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3365 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3366 object at VALADDR. See unpack_bits_as_long for more details. */
3369 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3371 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3372 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3373 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3375 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3378 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3379 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3380 the contents in DEST_VAL, zero or sign extending if the type of
3381 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3382 VAL. If the VAL's contents required to extract the bitfield from
3383 are unavailable/optimized out, DEST_VAL is correspondingly
3384 marked unavailable/optimized out. */
3387 unpack_value_bitfield (struct value
*dest_val
,
3388 int bitpos
, int bitsize
,
3389 const gdb_byte
*valaddr
, int embedded_offset
,
3390 const struct value
*val
)
3392 enum bfd_endian byte_order
;
3396 struct type
*field_type
= value_type (dest_val
);
3398 /* First, unpack and sign extend the bitfield as if it was wholly
3399 available. Invalid/unavailable bits are read as zero, but that's
3400 OK, as they'll end up marked below. */
3401 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3402 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3404 store_signed_integer (value_contents_raw (dest_val
),
3405 TYPE_LENGTH (field_type
), byte_order
, num
);
3407 /* Now copy the optimized out / unavailability ranges to the right
3409 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3410 if (byte_order
== BFD_ENDIAN_BIG
)
3411 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3414 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3415 val
, src_bit_offset
, bitsize
);
3418 /* Return a new value with type TYPE, which is FIELDNO field of the
3419 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3420 of VAL. If the VAL's contents required to extract the bitfield
3421 from are unavailable/optimized out, the new value is
3422 correspondingly marked unavailable/optimized out. */
3425 value_field_bitfield (struct type
*type
, int fieldno
,
3426 const gdb_byte
*valaddr
,
3427 int embedded_offset
, const struct value
*val
)
3429 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3430 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3431 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3433 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3434 valaddr
, embedded_offset
, val
);
3439 /* Modify the value of a bitfield. ADDR points to a block of memory in
3440 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3441 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3442 indicate which bits (in target bit order) comprise the bitfield.
3443 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3444 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3447 modify_field (struct type
*type
, gdb_byte
*addr
,
3448 LONGEST fieldval
, int bitpos
, int bitsize
)
3450 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3452 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3455 /* Normalize BITPOS. */
3459 /* If a negative fieldval fits in the field in question, chop
3460 off the sign extension bits. */
3461 if ((~fieldval
& ~(mask
>> 1)) == 0)
3464 /* Warn if value is too big to fit in the field in question. */
3465 if (0 != (fieldval
& ~mask
))
3467 /* FIXME: would like to include fieldval in the message, but
3468 we don't have a sprintf_longest. */
3469 warning (_("Value does not fit in %d bits."), bitsize
);
3471 /* Truncate it, otherwise adjoining fields may be corrupted. */
3475 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3476 false valgrind reports. */
3478 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3479 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3481 /* Shifting for bit field depends on endianness of the target machine. */
3482 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3483 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3485 oword
&= ~(mask
<< bitpos
);
3486 oword
|= fieldval
<< bitpos
;
3488 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3491 /* Pack NUM into BUF using a target format of TYPE. */
3494 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3496 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3499 type
= check_typedef (type
);
3500 len
= TYPE_LENGTH (type
);
3502 switch (TYPE_CODE (type
))
3505 case TYPE_CODE_CHAR
:
3506 case TYPE_CODE_ENUM
:
3507 case TYPE_CODE_FLAGS
:
3508 case TYPE_CODE_BOOL
:
3509 case TYPE_CODE_RANGE
:
3510 case TYPE_CODE_MEMBERPTR
:
3511 store_signed_integer (buf
, len
, byte_order
, num
);
3516 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3520 error (_("Unexpected type (%d) encountered for integer constant."),
3526 /* Pack NUM into BUF using a target format of TYPE. */
3529 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3532 enum bfd_endian byte_order
;
3534 type
= check_typedef (type
);
3535 len
= TYPE_LENGTH (type
);
3536 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3538 switch (TYPE_CODE (type
))
3541 case TYPE_CODE_CHAR
:
3542 case TYPE_CODE_ENUM
:
3543 case TYPE_CODE_FLAGS
:
3544 case TYPE_CODE_BOOL
:
3545 case TYPE_CODE_RANGE
:
3546 case TYPE_CODE_MEMBERPTR
:
3547 store_unsigned_integer (buf
, len
, byte_order
, num
);
3552 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3556 error (_("Unexpected type (%d) encountered "
3557 "for unsigned integer constant."),
3563 /* Convert C numbers into newly allocated values. */
3566 value_from_longest (struct type
*type
, LONGEST num
)
3568 struct value
*val
= allocate_value (type
);
3570 pack_long (value_contents_raw (val
), type
, num
);
3575 /* Convert C unsigned numbers into newly allocated values. */
3578 value_from_ulongest (struct type
*type
, ULONGEST num
)
3580 struct value
*val
= allocate_value (type
);
3582 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3588 /* Create a value representing a pointer of type TYPE to the address
3592 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3594 struct value
*val
= allocate_value (type
);
3596 store_typed_address (value_contents_raw (val
),
3597 check_typedef (type
), addr
);
3602 /* Create a value of type TYPE whose contents come from VALADDR, if it
3603 is non-null, and whose memory address (in the inferior) is
3604 ADDRESS. The type of the created value may differ from the passed
3605 type TYPE. Make sure to retrieve values new type after this call.
3606 Note that TYPE is not passed through resolve_dynamic_type; this is
3607 a special API intended for use only by Ada. */
3610 value_from_contents_and_address_unresolved (struct type
*type
,
3611 const gdb_byte
*valaddr
,
3616 if (valaddr
== NULL
)
3617 v
= allocate_value_lazy (type
);
3619 v
= value_from_contents (type
, valaddr
);
3620 set_value_address (v
, address
);
3621 VALUE_LVAL (v
) = lval_memory
;
3625 /* Create a value of type TYPE whose contents come from VALADDR, if it
3626 is non-null, and whose memory address (in the inferior) is
3627 ADDRESS. The type of the created value may differ from the passed
3628 type TYPE. Make sure to retrieve values new type after this call. */
3631 value_from_contents_and_address (struct type
*type
,
3632 const gdb_byte
*valaddr
,
3635 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3636 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3639 if (valaddr
== NULL
)
3640 v
= allocate_value_lazy (resolved_type
);
3642 v
= value_from_contents (resolved_type
, valaddr
);
3643 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3644 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3645 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3646 set_value_address (v
, address
);
3647 VALUE_LVAL (v
) = lval_memory
;
3651 /* Create a value of type TYPE holding the contents CONTENTS.
3652 The new value is `not_lval'. */
3655 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3657 struct value
*result
;
3659 result
= allocate_value (type
);
3660 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3665 value_from_double (struct type
*type
, DOUBLEST num
)
3667 struct value
*val
= allocate_value (type
);
3668 struct type
*base_type
= check_typedef (type
);
3669 enum type_code code
= TYPE_CODE (base_type
);
3671 if (code
== TYPE_CODE_FLT
)
3673 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3676 error (_("Unexpected type encountered for floating constant."));
3682 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3684 struct value
*val
= allocate_value (type
);
3686 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3690 /* Extract a value from the history file. Input will be of the form
3691 $digits or $$digits. See block comment above 'write_dollar_variable'
3695 value_from_history_ref (const char *h
, const char **endp
)
3707 /* Find length of numeral string. */
3708 for (; isdigit (h
[len
]); len
++)
3711 /* Make sure numeral string is not part of an identifier. */
3712 if (h
[len
] == '_' || isalpha (h
[len
]))
3715 /* Now collect the index value. */
3720 /* For some bizarre reason, "$$" is equivalent to "$$1",
3721 rather than to "$$0" as it ought to be! */
3729 index
= -strtol (&h
[2], &local_end
, 10);
3737 /* "$" is equivalent to "$0". */
3745 index
= strtol (&h
[1], &local_end
, 10);
3750 return access_value_history (index
);
3754 coerce_ref_if_computed (const struct value
*arg
)
3756 const struct lval_funcs
*funcs
;
3758 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3761 if (value_lval_const (arg
) != lval_computed
)
3764 funcs
= value_computed_funcs (arg
);
3765 if (funcs
->coerce_ref
== NULL
)
3768 return funcs
->coerce_ref (arg
);
3771 /* Look at value.h for description. */
3774 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3775 const struct type
*original_type
,
3776 const struct value
*original_value
)
3778 /* Re-adjust type. */
3779 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3781 /* Add embedding info. */
3782 set_value_enclosing_type (value
, enc_type
);
3783 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3785 /* We may be pointing to an object of some derived type. */
3786 return value_full_object (value
, NULL
, 0, 0, 0);
3790 coerce_ref (struct value
*arg
)
3792 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3793 struct value
*retval
;
3794 struct type
*enc_type
;
3796 retval
= coerce_ref_if_computed (arg
);
3800 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3803 enc_type
= check_typedef (value_enclosing_type (arg
));
3804 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3806 retval
= value_at_lazy (enc_type
,
3807 unpack_pointer (value_type (arg
),
3808 value_contents (arg
)));
3809 enc_type
= value_type (retval
);
3810 return readjust_indirect_value_type (retval
, enc_type
,
3811 value_type_arg_tmp
, arg
);
3815 coerce_array (struct value
*arg
)
3819 arg
= coerce_ref (arg
);
3820 type
= check_typedef (value_type (arg
));
3822 switch (TYPE_CODE (type
))
3824 case TYPE_CODE_ARRAY
:
3825 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3826 arg
= value_coerce_array (arg
);
3828 case TYPE_CODE_FUNC
:
3829 arg
= value_coerce_function (arg
);
3836 /* Return the return value convention that will be used for the
3839 enum return_value_convention
3840 struct_return_convention (struct gdbarch
*gdbarch
,
3841 struct value
*function
, struct type
*value_type
)
3843 enum type_code code
= TYPE_CODE (value_type
);
3845 if (code
== TYPE_CODE_ERROR
)
3846 error (_("Function return type unknown."));
3848 /* Probe the architecture for the return-value convention. */
3849 return gdbarch_return_value (gdbarch
, function
, value_type
,
3853 /* Return true if the function returning the specified type is using
3854 the convention of returning structures in memory (passing in the
3855 address as a hidden first parameter). */
3858 using_struct_return (struct gdbarch
*gdbarch
,
3859 struct value
*function
, struct type
*value_type
)
3861 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3862 /* A void return value is never in memory. See also corresponding
3863 code in "print_return_value". */
3866 return (struct_return_convention (gdbarch
, function
, value_type
)
3867 != RETURN_VALUE_REGISTER_CONVENTION
);
3870 /* Set the initialized field in a value struct. */
3873 set_value_initialized (struct value
*val
, int status
)
3875 val
->initialized
= status
;
3878 /* Return the initialized field in a value struct. */
3881 value_initialized (const struct value
*val
)
3883 return val
->initialized
;
3886 /* Load the actual content of a lazy value. Fetch the data from the
3887 user's process and clear the lazy flag to indicate that the data in
3888 the buffer is valid.
3890 If the value is zero-length, we avoid calling read_memory, which
3891 would abort. We mark the value as fetched anyway -- all 0 bytes of
3895 value_fetch_lazy (struct value
*val
)
3897 gdb_assert (value_lazy (val
));
3898 allocate_value_contents (val
);
3899 /* A value is either lazy, or fully fetched. The
3900 availability/validity is only established as we try to fetch a
3902 gdb_assert (VEC_empty (range_s
, val
->optimized_out
));
3903 gdb_assert (VEC_empty (range_s
, val
->unavailable
));
3904 if (value_bitsize (val
))
3906 /* To read a lazy bitfield, read the entire enclosing value. This
3907 prevents reading the same block of (possibly volatile) memory once
3908 per bitfield. It would be even better to read only the containing
3909 word, but we have no way to record that just specific bits of a
3910 value have been fetched. */
3911 struct type
*type
= check_typedef (value_type (val
));
3912 struct value
*parent
= value_parent (val
);
3914 if (value_lazy (parent
))
3915 value_fetch_lazy (parent
);
3917 unpack_value_bitfield (val
,
3918 value_bitpos (val
), value_bitsize (val
),
3919 value_contents_for_printing (parent
),
3920 value_offset (val
), parent
);
3922 else if (VALUE_LVAL (val
) == lval_memory
)
3924 CORE_ADDR addr
= value_address (val
);
3925 struct type
*type
= check_typedef (value_enclosing_type (val
));
3927 if (TYPE_LENGTH (type
))
3928 read_value_memory (val
, 0, value_stack (val
),
3929 addr
, value_contents_all_raw (val
),
3930 type_length_units (type
));
3932 else if (VALUE_LVAL (val
) == lval_register
)
3934 struct frame_info
*frame
;
3936 struct type
*type
= check_typedef (value_type (val
));
3937 struct value
*new_val
= val
, *mark
= value_mark ();
3939 /* Offsets are not supported here; lazy register values must
3940 refer to the entire register. */
3941 gdb_assert (value_offset (val
) == 0);
3943 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3945 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3947 frame
= frame_find_by_id (frame_id
);
3948 regnum
= VALUE_REGNUM (new_val
);
3950 gdb_assert (frame
!= NULL
);
3952 /* Convertible register routines are used for multi-register
3953 values and for interpretation in different types
3954 (e.g. float or int from a double register). Lazy
3955 register values should have the register's natural type,
3956 so they do not apply. */
3957 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3960 new_val
= get_frame_register_value (frame
, regnum
);
3962 /* If we get another lazy lval_register value, it means the
3963 register is found by reading it from the next frame.
3964 get_frame_register_value should never return a value with
3965 the frame id pointing to FRAME. If it does, it means we
3966 either have two consecutive frames with the same frame id
3967 in the frame chain, or some code is trying to unwind
3968 behind get_prev_frame's back (e.g., a frame unwind
3969 sniffer trying to unwind), bypassing its validations. In
3970 any case, it should always be an internal error to end up
3971 in this situation. */
3972 if (VALUE_LVAL (new_val
) == lval_register
3973 && value_lazy (new_val
)
3974 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
3975 internal_error (__FILE__
, __LINE__
,
3976 _("infinite loop while fetching a register"));
3979 /* If it's still lazy (for instance, a saved register on the
3980 stack), fetch it. */
3981 if (value_lazy (new_val
))
3982 value_fetch_lazy (new_val
);
3984 /* Copy the contents and the unavailability/optimized-out
3985 meta-data from NEW_VAL to VAL. */
3986 set_value_lazy (val
, 0);
3987 value_contents_copy (val
, value_embedded_offset (val
),
3988 new_val
, value_embedded_offset (new_val
),
3989 type_length_units (type
));
3993 struct gdbarch
*gdbarch
;
3994 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3995 regnum
= VALUE_REGNUM (val
);
3996 gdbarch
= get_frame_arch (frame
);
3998 fprintf_unfiltered (gdb_stdlog
,
3999 "{ value_fetch_lazy "
4000 "(frame=%d,regnum=%d(%s),...) ",
4001 frame_relative_level (frame
), regnum
,
4002 user_reg_map_regnum_to_name (gdbarch
, regnum
));
4004 fprintf_unfiltered (gdb_stdlog
, "->");
4005 if (value_optimized_out (new_val
))
4007 fprintf_unfiltered (gdb_stdlog
, " ");
4008 val_print_optimized_out (new_val
, gdb_stdlog
);
4013 const gdb_byte
*buf
= value_contents (new_val
);
4015 if (VALUE_LVAL (new_val
) == lval_register
)
4016 fprintf_unfiltered (gdb_stdlog
, " register=%d",
4017 VALUE_REGNUM (new_val
));
4018 else if (VALUE_LVAL (new_val
) == lval_memory
)
4019 fprintf_unfiltered (gdb_stdlog
, " address=%s",
4021 value_address (new_val
)));
4023 fprintf_unfiltered (gdb_stdlog
, " computed");
4025 fprintf_unfiltered (gdb_stdlog
, " bytes=");
4026 fprintf_unfiltered (gdb_stdlog
, "[");
4027 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
4028 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
4029 fprintf_unfiltered (gdb_stdlog
, "]");
4032 fprintf_unfiltered (gdb_stdlog
, " }\n");
4035 /* Dispose of the intermediate values. This prevents
4036 watchpoints from trying to watch the saved frame pointer. */
4037 value_free_to_mark (mark
);
4039 else if (VALUE_LVAL (val
) == lval_computed
4040 && value_computed_funcs (val
)->read
!= NULL
)
4041 value_computed_funcs (val
)->read (val
);
4043 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
4045 set_value_lazy (val
, 0);
4048 /* Implementation of the convenience function $_isvoid. */
4050 static struct value
*
4051 isvoid_internal_fn (struct gdbarch
*gdbarch
,
4052 const struct language_defn
*language
,
4053 void *cookie
, int argc
, struct value
**argv
)
4058 error (_("You must provide one argument for $_isvoid."));
4060 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
4062 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
4066 _initialize_values (void)
4068 add_cmd ("convenience", no_class
, show_convenience
, _("\
4069 Debugger convenience (\"$foo\") variables and functions.\n\
4070 Convenience variables are created when you assign them values;\n\
4071 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4073 A few convenience variables are given values automatically:\n\
4074 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4075 \"$__\" holds the contents of the last address examined with \"x\"."
4078 Convenience functions are defined via the Python API."
4081 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
4083 add_cmd ("values", no_set_class
, show_values
, _("\
4084 Elements of value history around item number IDX (or last ten)."),
4087 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
4088 Initialize a convenience variable if necessary.\n\
4089 init-if-undefined VARIABLE = EXPRESSION\n\
4090 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4091 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4092 VARIABLE is already initialized."));
4094 add_prefix_cmd ("function", no_class
, function_command
, _("\
4095 Placeholder command for showing help on convenience functions."),
4096 &functionlist
, "function ", 0, &cmdlist
);
4098 add_internal_function ("_isvoid", _("\
4099 Check whether an expression is void.\n\
4100 Usage: $_isvoid (expression)\n\
4101 Return 1 if the expression is void, zero otherwise."),
4102 isvoid_internal_fn
, NULL
);
4104 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4105 class_support
, &max_value_size
, _("\
4106 Set maximum sized value gdb will load from the inferior."), _("\
4107 Show maximum sized value gdb will load from the inferior."), _("\
4108 Use this to control the maximum size, in bytes, of a value that gdb\n\
4109 will load from the inferior. Setting this value to 'unlimited'\n\
4110 disables checking.\n\
4111 Setting this does not invalidate already allocated values, it only\n\
4112 prevents future values, larger than this size, from being allocated."),
4114 show_max_value_size
,
4115 &setlist
, &showlist
);