1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2014 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
45 #include "user-regs.h"
47 /* Prototypes for exported functions. */
49 void _initialize_values (void);
51 /* Definition of a user function. */
52 struct internal_function
54 /* The name of the function. It is a bit odd to have this in the
55 function itself -- the user might use a differently-named
56 convenience variable to hold the function. */
60 internal_function_fn handler
;
62 /* User data for the handler. */
66 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
70 /* Lowest offset in the range. */
73 /* Length of the range. */
77 typedef struct range range_s
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (int offset1
, int len1
,
86 int offset2
, int len2
)
90 l
= max (offset1
, offset2
);
91 h
= min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if the first argument is strictly less than the
96 second, useful for VEC_lower_bound. We keep ranges sorted by
97 offset and coalesce overlapping and contiguous ranges, so this just
98 compares the starting offset. */
101 range_lessthan (const range_s
*r1
, const range_s
*r2
)
103 return r1
->offset
< r2
->offset
;
106 /* Returns true if RANGES contains any range that overlaps [OFFSET,
110 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
115 what
.offset
= offset
;
116 what
.length
= length
;
118 /* We keep ranges sorted by offset and coalesce overlapping and
119 contiguous ranges, so to check if a range list contains a given
120 range, we can do a binary search for the position the given range
121 would be inserted if we only considered the starting OFFSET of
122 ranges. We call that position I. Since we also have LENGTH to
123 care for (this is a range afterall), we need to check if the
124 _previous_ range overlaps the I range. E.g.,
128 |---| |---| |------| ... |--|
133 In the case above, the binary search would return `I=1', meaning,
134 this OFFSET should be inserted at position 1, and the current
135 position 1 should be pushed further (and before 2). But, `0'
138 Then we need to check if the I range overlaps the I range itself.
143 |---| |---| |-------| ... |--|
149 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
153 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
155 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
159 if (i
< VEC_length (range_s
, ranges
))
161 struct range
*r
= VEC_index (range_s
, ranges
, i
);
163 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
170 static struct cmd_list_element
*functionlist
;
172 /* Note that the fields in this structure are arranged to save a bit
177 /* Type of value; either not an lval, or one of the various
178 different possible kinds of lval. */
181 /* Is it modifiable? Only relevant if lval != not_lval. */
182 unsigned int modifiable
: 1;
184 /* If zero, contents of this value are in the contents field. If
185 nonzero, contents are in inferior. If the lval field is lval_memory,
186 the contents are in inferior memory at location.address plus offset.
187 The lval field may also be lval_register.
189 WARNING: This field is used by the code which handles watchpoints
190 (see breakpoint.c) to decide whether a particular value can be
191 watched by hardware watchpoints. If the lazy flag is set for
192 some member of a value chain, it is assumed that this member of
193 the chain doesn't need to be watched as part of watching the
194 value itself. This is how GDB avoids watching the entire struct
195 or array when the user wants to watch a single struct member or
196 array element. If you ever change the way lazy flag is set and
197 reset, be sure to consider this use as well! */
198 unsigned int lazy
: 1;
200 /* If nonzero, this is the value of a variable that does not
201 actually exist in the program. If nonzero, and LVAL is
202 lval_register, this is a register ($pc, $sp, etc., never a
203 program variable) that has not been saved in the frame. All
204 optimized-out values are treated pretty much the same, except
205 registers have a different string representation and related
207 unsigned int optimized_out
: 1;
209 /* If value is a variable, is it initialized or not. */
210 unsigned int initialized
: 1;
212 /* If value is from the stack. If this is set, read_stack will be
213 used instead of read_memory to enable extra caching. */
214 unsigned int stack
: 1;
216 /* If the value has been released. */
217 unsigned int released
: 1;
219 /* Location of value (if lval). */
222 /* If lval == lval_memory, this is the address in the inferior.
223 If lval == lval_register, this is the byte offset into the
224 registers structure. */
227 /* Pointer to internal variable. */
228 struct internalvar
*internalvar
;
230 /* If lval == lval_computed, this is a set of function pointers
231 to use to access and describe the value, and a closure pointer
235 /* Functions to call. */
236 const struct lval_funcs
*funcs
;
238 /* Closure for those functions to use. */
243 /* Describes offset of a value within lval of a structure in bytes.
244 If lval == lval_memory, this is an offset to the address. If
245 lval == lval_register, this is a further offset from
246 location.address within the registers structure. Note also the
247 member embedded_offset below. */
250 /* Only used for bitfields; number of bits contained in them. */
253 /* Only used for bitfields; position of start of field. For
254 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
255 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
258 /* The number of references to this value. When a value is created,
259 the value chain holds a reference, so REFERENCE_COUNT is 1. If
260 release_value is called, this value is removed from the chain but
261 the caller of release_value now has a reference to this value.
262 The caller must arrange for a call to value_free later. */
265 /* Only used for bitfields; the containing value. This allows a
266 single read from the target when displaying multiple
268 struct value
*parent
;
270 /* Frame register value is relative to. This will be described in
271 the lval enum above as "lval_register". */
272 struct frame_id frame_id
;
274 /* Type of the value. */
277 /* If a value represents a C++ object, then the `type' field gives
278 the object's compile-time type. If the object actually belongs
279 to some class derived from `type', perhaps with other base
280 classes and additional members, then `type' is just a subobject
281 of the real thing, and the full object is probably larger than
282 `type' would suggest.
284 If `type' is a dynamic class (i.e. one with a vtable), then GDB
285 can actually determine the object's run-time type by looking at
286 the run-time type information in the vtable. When this
287 information is available, we may elect to read in the entire
288 object, for several reasons:
290 - When printing the value, the user would probably rather see the
291 full object, not just the limited portion apparent from the
294 - If `type' has virtual base classes, then even printing `type'
295 alone may require reaching outside the `type' portion of the
296 object to wherever the virtual base class has been stored.
298 When we store the entire object, `enclosing_type' is the run-time
299 type -- the complete object -- and `embedded_offset' is the
300 offset of `type' within that larger type, in bytes. The
301 value_contents() macro takes `embedded_offset' into account, so
302 most GDB code continues to see the `type' portion of the value,
303 just as the inferior would.
305 If `type' is a pointer to an object, then `enclosing_type' is a
306 pointer to the object's run-time type, and `pointed_to_offset' is
307 the offset in bytes from the full object to the pointed-to object
308 -- that is, the value `embedded_offset' would have if we followed
309 the pointer and fetched the complete object. (I don't really see
310 the point. Why not just determine the run-time type when you
311 indirect, and avoid the special case? The contents don't matter
312 until you indirect anyway.)
314 If we're not doing anything fancy, `enclosing_type' is equal to
315 `type', and `embedded_offset' is zero, so everything works
317 struct type
*enclosing_type
;
319 int pointed_to_offset
;
321 /* Values are stored in a chain, so that they can be deleted easily
322 over calls to the inferior. Values assigned to internal
323 variables, put into the value history or exposed to Python are
324 taken off this list. */
327 /* Register number if the value is from a register. */
330 /* Actual contents of the value. Target byte-order. NULL or not
331 valid if lazy is nonzero. */
334 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
335 rather than available, since the common and default case is for a
336 value to be available. This is filled in at value read time. The
337 unavailable ranges are tracked in bits. */
338 VEC(range_s
) *unavailable
;
342 value_bits_available (const struct value
*value
, int offset
, int length
)
344 gdb_assert (!value
->lazy
);
346 return !ranges_contain (value
->unavailable
, offset
, length
);
350 value_bytes_available (const struct value
*value
, int offset
, int length
)
352 return value_bits_available (value
,
353 offset
* TARGET_CHAR_BIT
,
354 length
* TARGET_CHAR_BIT
);
358 value_entirely_available (struct value
*value
)
360 /* We can only tell whether the whole value is available when we try
363 value_fetch_lazy (value
);
365 if (VEC_empty (range_s
, value
->unavailable
))
371 value_entirely_unavailable (struct value
*value
)
373 /* We can only tell whether the whole value is available when we try
376 value_fetch_lazy (value
);
378 if (VEC_length (range_s
, value
->unavailable
) == 1)
380 struct range
*t
= VEC_index (range_s
, value
->unavailable
, 0);
383 && t
->length
== (TARGET_CHAR_BIT
384 * TYPE_LENGTH (value_enclosing_type (value
))))
392 mark_value_bits_unavailable (struct value
*value
, int offset
, int length
)
397 /* Insert the range sorted. If there's overlap or the new range
398 would be contiguous with an existing range, merge. */
400 newr
.offset
= offset
;
401 newr
.length
= length
;
403 /* Do a binary search for the position the given range would be
404 inserted if we only considered the starting OFFSET of ranges.
405 Call that position I. Since we also have LENGTH to care for
406 (this is a range afterall), we need to check if the _previous_
407 range overlaps the I range. E.g., calling R the new range:
409 #1 - overlaps with previous
413 |---| |---| |------| ... |--|
418 In the case #1 above, the binary search would return `I=1',
419 meaning, this OFFSET should be inserted at position 1, and the
420 current position 1 should be pushed further (and become 2). But,
421 note that `0' overlaps with R, so we want to merge them.
423 A similar consideration needs to be taken if the new range would
424 be contiguous with the previous range:
426 #2 - contiguous with previous
430 |--| |---| |------| ... |--|
435 If there's no overlap with the previous range, as in:
437 #3 - not overlapping and not contiguous
441 |--| |---| |------| ... |--|
448 #4 - R is the range with lowest offset
452 |--| |---| |------| ... |--|
457 ... we just push the new range to I.
459 All the 4 cases above need to consider that the new range may
460 also overlap several of the ranges that follow, or that R may be
461 contiguous with the following range, and merge. E.g.,
463 #5 - overlapping following ranges
466 |------------------------|
467 |--| |---| |------| ... |--|
476 |--| |---| |------| ... |--|
483 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
486 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
488 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
491 ULONGEST l
= min (bef
->offset
, offset
);
492 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
498 else if (offset
== bef
->offset
+ bef
->length
)
501 bef
->length
+= length
;
507 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
513 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
516 /* Check whether the ranges following the one we've just added or
517 touched can be folded in (#5 above). */
518 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
525 /* Get the range we just touched. */
526 t
= VEC_index (range_s
, value
->unavailable
, i
);
530 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
531 if (r
->offset
<= t
->offset
+ t
->length
)
535 l
= min (t
->offset
, r
->offset
);
536 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
545 /* If we couldn't merge this one, we won't be able to
546 merge following ones either, since the ranges are
547 always sorted by OFFSET. */
552 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
557 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
559 mark_value_bits_unavailable (value
,
560 offset
* TARGET_CHAR_BIT
,
561 length
* TARGET_CHAR_BIT
);
564 /* Find the first range in RANGES that overlaps the range defined by
565 OFFSET and LENGTH, starting at element POS in the RANGES vector,
566 Returns the index into RANGES where such overlapping range was
567 found, or -1 if none was found. */
570 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
571 int offset
, int length
)
576 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
577 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
583 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
584 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
587 It must always be the case that:
588 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
590 It is assumed that memory can be accessed from:
591 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
593 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
594 / TARGET_CHAR_BIT) */
596 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
597 const gdb_byte
*ptr2
, size_t offset2_bits
,
600 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
601 == offset2_bits
% TARGET_CHAR_BIT
);
603 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
606 gdb_byte mask
, b1
, b2
;
608 /* The offset from the base pointers PTR1 and PTR2 is not a complete
609 number of bytes. A number of bits up to either the next exact
610 byte boundary, or LENGTH_BITS (which ever is sooner) will be
612 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
613 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
614 mask
= (1 << bits
) - 1;
616 if (length_bits
< bits
)
618 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
622 /* Now load the two bytes and mask off the bits we care about. */
623 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
624 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
629 /* Now update the length and offsets to take account of the bits
630 we've just compared. */
632 offset1_bits
+= bits
;
633 offset2_bits
+= bits
;
636 if (length_bits
% TARGET_CHAR_BIT
!= 0)
640 gdb_byte mask
, b1
, b2
;
642 /* The length is not an exact number of bytes. After the previous
643 IF.. block then the offsets are byte aligned, or the
644 length is zero (in which case this code is not reached). Compare
645 a number of bits at the end of the region, starting from an exact
647 bits
= length_bits
% TARGET_CHAR_BIT
;
648 o1
= offset1_bits
+ length_bits
- bits
;
649 o2
= offset2_bits
+ length_bits
- bits
;
651 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
652 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
654 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
655 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
657 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
658 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
668 /* We've now taken care of any stray "bits" at the start, or end of
669 the region to compare, the remainder can be covered with a simple
671 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
672 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
673 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
675 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
676 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
677 length_bits
/ TARGET_CHAR_BIT
);
680 /* Length is zero, regions match. */
684 /* Helper function for value_available_contents_eq. The only difference is
685 that this function is bit rather than byte based.
687 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits with
688 LENGTH bits of VAL2's contents starting at OFFSET2 bits. Return true
689 if the available bits match. */
692 value_available_contents_bits_eq (const struct value
*val1
, int offset1
,
693 const struct value
*val2
, int offset2
,
696 int idx1
= 0, idx2
= 0;
698 /* See function description in value.h. */
699 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
707 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
709 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
712 /* The usual case is for both values to be completely available. */
713 if (idx1
== -1 && idx2
== -1)
714 return (memcmp_with_bit_offsets (val1
->contents
, offset1
,
715 val2
->contents
, offset2
,
717 /* The contents only match equal if the available set matches as
719 else if (idx1
== -1 || idx2
== -1)
722 gdb_assert (idx1
!= -1 && idx2
!= -1);
724 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
725 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
727 /* Get the unavailable windows intersected by the incoming
728 ranges. The first and last ranges that overlap the argument
729 range may be wider than said incoming arguments ranges. */
730 l1
= max (offset1
, r1
->offset
);
731 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
733 l2
= max (offset2
, r2
->offset
);
734 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
736 /* Make them relative to the respective start offsets, so we can
737 compare them for equality. */
744 /* Different availability, no match. */
745 if (l1
!= l2
|| h1
!= h2
)
748 /* Compare the _available_ contents. */
749 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
750 val2
->contents
, offset2
, l1
) != 0)
762 value_available_contents_eq (const struct value
*val1
, int offset1
,
763 const struct value
*val2
, int offset2
,
766 return value_available_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
767 val2
, offset2
* TARGET_CHAR_BIT
,
768 length
* TARGET_CHAR_BIT
);
771 /* Prototypes for local functions. */
773 static void show_values (char *, int);
775 static void show_convenience (char *, int);
778 /* The value-history records all the values printed
779 by print commands during this session. Each chunk
780 records 60 consecutive values. The first chunk on
781 the chain records the most recent values.
782 The total number of values is in value_history_count. */
784 #define VALUE_HISTORY_CHUNK 60
786 struct value_history_chunk
788 struct value_history_chunk
*next
;
789 struct value
*values
[VALUE_HISTORY_CHUNK
];
792 /* Chain of chunks now in use. */
794 static struct value_history_chunk
*value_history_chain
;
796 static int value_history_count
; /* Abs number of last entry stored. */
799 /* List of all value objects currently allocated
800 (except for those released by calls to release_value)
801 This is so they can be freed after each command. */
803 static struct value
*all_values
;
805 /* Allocate a lazy value for type TYPE. Its actual content is
806 "lazily" allocated too: the content field of the return value is
807 NULL; it will be allocated when it is fetched from the target. */
810 allocate_value_lazy (struct type
*type
)
814 /* Call check_typedef on our type to make sure that, if TYPE
815 is a TYPE_CODE_TYPEDEF, its length is set to the length
816 of the target type instead of zero. However, we do not
817 replace the typedef type by the target type, because we want
818 to keep the typedef in order to be able to set the VAL's type
819 description correctly. */
820 check_typedef (type
);
822 val
= (struct value
*) xzalloc (sizeof (struct value
));
823 val
->contents
= NULL
;
824 val
->next
= all_values
;
827 val
->enclosing_type
= type
;
828 VALUE_LVAL (val
) = not_lval
;
829 val
->location
.address
= 0;
830 VALUE_FRAME_ID (val
) = null_frame_id
;
834 VALUE_REGNUM (val
) = -1;
836 val
->optimized_out
= 0;
837 val
->embedded_offset
= 0;
838 val
->pointed_to_offset
= 0;
840 val
->initialized
= 1; /* Default to initialized. */
842 /* Values start out on the all_values chain. */
843 val
->reference_count
= 1;
848 /* Allocate the contents of VAL if it has not been allocated yet. */
851 allocate_value_contents (struct value
*val
)
854 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
857 /* Allocate a value and its contents for type TYPE. */
860 allocate_value (struct type
*type
)
862 struct value
*val
= allocate_value_lazy (type
);
864 allocate_value_contents (val
);
869 /* Allocate a value that has the correct length
870 for COUNT repetitions of type TYPE. */
873 allocate_repeat_value (struct type
*type
, int count
)
875 int low_bound
= current_language
->string_lower_bound
; /* ??? */
876 /* FIXME-type-allocation: need a way to free this type when we are
878 struct type
*array_type
879 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
881 return allocate_value (array_type
);
885 allocate_computed_value (struct type
*type
,
886 const struct lval_funcs
*funcs
,
889 struct value
*v
= allocate_value_lazy (type
);
891 VALUE_LVAL (v
) = lval_computed
;
892 v
->location
.computed
.funcs
= funcs
;
893 v
->location
.computed
.closure
= closure
;
898 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
901 allocate_optimized_out_value (struct type
*type
)
903 struct value
*retval
= allocate_value_lazy (type
);
905 set_value_optimized_out (retval
, 1);
906 set_value_lazy (retval
, 0);
910 /* Accessor methods. */
913 value_next (struct value
*value
)
919 value_type (const struct value
*value
)
924 deprecated_set_value_type (struct value
*value
, struct type
*type
)
930 value_offset (const struct value
*value
)
932 return value
->offset
;
935 set_value_offset (struct value
*value
, int offset
)
937 value
->offset
= offset
;
941 value_bitpos (const struct value
*value
)
943 return value
->bitpos
;
946 set_value_bitpos (struct value
*value
, int bit
)
952 value_bitsize (const struct value
*value
)
954 return value
->bitsize
;
957 set_value_bitsize (struct value
*value
, int bit
)
959 value
->bitsize
= bit
;
963 value_parent (struct value
*value
)
965 return value
->parent
;
971 set_value_parent (struct value
*value
, struct value
*parent
)
973 struct value
*old
= value
->parent
;
975 value
->parent
= parent
;
977 value_incref (parent
);
982 value_contents_raw (struct value
*value
)
984 allocate_value_contents (value
);
985 return value
->contents
+ value
->embedded_offset
;
989 value_contents_all_raw (struct value
*value
)
991 allocate_value_contents (value
);
992 return value
->contents
;
996 value_enclosing_type (struct value
*value
)
998 return value
->enclosing_type
;
1001 /* Look at value.h for description. */
1004 value_actual_type (struct value
*value
, int resolve_simple_types
,
1005 int *real_type_found
)
1007 struct value_print_options opts
;
1008 struct type
*result
;
1010 get_user_print_options (&opts
);
1012 if (real_type_found
)
1013 *real_type_found
= 0;
1014 result
= value_type (value
);
1015 if (opts
.objectprint
)
1017 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1018 fetch its rtti type. */
1019 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1020 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1021 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1022 == TYPE_CODE_STRUCT
)
1024 struct type
*real_type
;
1026 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1029 if (real_type_found
)
1030 *real_type_found
= 1;
1034 else if (resolve_simple_types
)
1036 if (real_type_found
)
1037 *real_type_found
= 1;
1038 result
= value_enclosing_type (value
);
1046 error_value_optimized_out (void)
1048 error (_("value has been optimized out"));
1052 require_not_optimized_out (const struct value
*value
)
1054 if (value
->optimized_out
)
1056 if (value
->lval
== lval_register
)
1057 error (_("register has not been saved in frame"));
1059 error_value_optimized_out ();
1064 require_available (const struct value
*value
)
1066 if (!VEC_empty (range_s
, value
->unavailable
))
1067 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1071 value_contents_for_printing (struct value
*value
)
1074 value_fetch_lazy (value
);
1075 return value
->contents
;
1079 value_contents_for_printing_const (const struct value
*value
)
1081 gdb_assert (!value
->lazy
);
1082 return value
->contents
;
1086 value_contents_all (struct value
*value
)
1088 const gdb_byte
*result
= value_contents_for_printing (value
);
1089 require_not_optimized_out (value
);
1090 require_available (value
);
1094 /* Copy LENGTH bytes of SRC value's (all) contents
1095 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1096 contents, starting at DST_OFFSET. If unavailable contents are
1097 being copied from SRC, the corresponding DST contents are marked
1098 unavailable accordingly. Neither DST nor SRC may be lazy
1101 It is assumed the contents of DST in the [DST_OFFSET,
1102 DST_OFFSET+LENGTH) range are wholly available. */
1105 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
1106 struct value
*src
, int src_offset
, int length
)
1110 int src_bit_offset
, dst_bit_offset
, bit_length
;
1112 /* A lazy DST would make that this copy operation useless, since as
1113 soon as DST's contents were un-lazied (by a later value_contents
1114 call, say), the contents would be overwritten. A lazy SRC would
1115 mean we'd be copying garbage. */
1116 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1118 /* The overwritten DST range gets unavailability ORed in, not
1119 replaced. Make sure to remember to implement replacing if it
1120 turns out actually necessary. */
1121 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1123 /* Copy the data. */
1124 memcpy (value_contents_all_raw (dst
) + dst_offset
,
1125 value_contents_all_raw (src
) + src_offset
,
1128 /* Copy the meta-data, adjusted. */
1129 src_bit_offset
= src_offset
* TARGET_CHAR_BIT
;
1130 dst_bit_offset
= dst_offset
* TARGET_CHAR_BIT
;
1131 bit_length
= length
* TARGET_CHAR_BIT
;
1132 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
1136 l
= max (r
->offset
, src_bit_offset
);
1137 h
= min (r
->offset
+ r
->length
, src_bit_offset
+ bit_length
);
1140 mark_value_bits_unavailable (dst
,
1141 dst_bit_offset
+ (l
- src_bit_offset
),
1146 /* Copy LENGTH bytes of SRC value's (all) contents
1147 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1148 (all) contents, starting at DST_OFFSET. If unavailable contents
1149 are being copied from SRC, the corresponding DST contents are
1150 marked unavailable accordingly. DST must not be lazy. If SRC is
1151 lazy, it will be fetched now. If SRC is not valid (is optimized
1152 out), an error is thrown.
1154 It is assumed the contents of DST in the [DST_OFFSET,
1155 DST_OFFSET+LENGTH) range are wholly available. */
1158 value_contents_copy (struct value
*dst
, int dst_offset
,
1159 struct value
*src
, int src_offset
, int length
)
1161 require_not_optimized_out (src
);
1164 value_fetch_lazy (src
);
1166 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1170 value_lazy (struct value
*value
)
1176 set_value_lazy (struct value
*value
, int val
)
1182 value_stack (struct value
*value
)
1184 return value
->stack
;
1188 set_value_stack (struct value
*value
, int val
)
1194 value_contents (struct value
*value
)
1196 const gdb_byte
*result
= value_contents_writeable (value
);
1197 require_not_optimized_out (value
);
1198 require_available (value
);
1203 value_contents_writeable (struct value
*value
)
1206 value_fetch_lazy (value
);
1207 return value_contents_raw (value
);
1210 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1211 this function is different from value_equal; in C the operator ==
1212 can return 0 even if the two values being compared are equal. */
1215 value_contents_equal (struct value
*val1
, struct value
*val2
)
1220 type1
= check_typedef (value_type (val1
));
1221 type2
= check_typedef (value_type (val2
));
1222 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1225 return (memcmp (value_contents (val1
), value_contents (val2
),
1226 TYPE_LENGTH (type1
)) == 0);
1230 value_optimized_out (struct value
*value
)
1232 /* We can only know if a value is optimized out once we have tried to
1234 if (!value
->optimized_out
&& value
->lazy
)
1235 value_fetch_lazy (value
);
1237 return value
->optimized_out
;
1241 value_optimized_out_const (const struct value
*value
)
1243 return value
->optimized_out
;
1247 set_value_optimized_out (struct value
*value
, int val
)
1249 value
->optimized_out
= val
;
1253 value_entirely_optimized_out (const struct value
*value
)
1255 if (!value
->optimized_out
)
1257 if (value
->lval
!= lval_computed
1258 || !value
->location
.computed
.funcs
->check_any_valid
)
1260 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1264 value_bits_valid (const struct value
*value
, int offset
, int length
)
1266 if (!value
->optimized_out
)
1268 if (value
->lval
!= lval_computed
1269 || !value
->location
.computed
.funcs
->check_validity
)
1271 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1276 value_bits_synthetic_pointer (const struct value
*value
,
1277 int offset
, int length
)
1279 if (value
->lval
!= lval_computed
1280 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1282 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1288 value_embedded_offset (struct value
*value
)
1290 return value
->embedded_offset
;
1294 set_value_embedded_offset (struct value
*value
, int val
)
1296 value
->embedded_offset
= val
;
1300 value_pointed_to_offset (struct value
*value
)
1302 return value
->pointed_to_offset
;
1306 set_value_pointed_to_offset (struct value
*value
, int val
)
1308 value
->pointed_to_offset
= val
;
1311 const struct lval_funcs
*
1312 value_computed_funcs (const struct value
*v
)
1314 gdb_assert (value_lval_const (v
) == lval_computed
);
1316 return v
->location
.computed
.funcs
;
1320 value_computed_closure (const struct value
*v
)
1322 gdb_assert (v
->lval
== lval_computed
);
1324 return v
->location
.computed
.closure
;
1328 deprecated_value_lval_hack (struct value
*value
)
1330 return &value
->lval
;
1334 value_lval_const (const struct value
*value
)
1340 value_address (const struct value
*value
)
1342 if (value
->lval
== lval_internalvar
1343 || value
->lval
== lval_internalvar_component
)
1345 if (value
->parent
!= NULL
)
1346 return value_address (value
->parent
) + value
->offset
;
1348 return value
->location
.address
+ value
->offset
;
1352 value_raw_address (struct value
*value
)
1354 if (value
->lval
== lval_internalvar
1355 || value
->lval
== lval_internalvar_component
)
1357 return value
->location
.address
;
1361 set_value_address (struct value
*value
, CORE_ADDR addr
)
1363 gdb_assert (value
->lval
!= lval_internalvar
1364 && value
->lval
!= lval_internalvar_component
);
1365 value
->location
.address
= addr
;
1368 struct internalvar
**
1369 deprecated_value_internalvar_hack (struct value
*value
)
1371 return &value
->location
.internalvar
;
1375 deprecated_value_frame_id_hack (struct value
*value
)
1377 return &value
->frame_id
;
1381 deprecated_value_regnum_hack (struct value
*value
)
1383 return &value
->regnum
;
1387 deprecated_value_modifiable (struct value
*value
)
1389 return value
->modifiable
;
1392 /* Return a mark in the value chain. All values allocated after the
1393 mark is obtained (except for those released) are subject to being freed
1394 if a subsequent value_free_to_mark is passed the mark. */
1401 /* Take a reference to VAL. VAL will not be deallocated until all
1402 references are released. */
1405 value_incref (struct value
*val
)
1407 val
->reference_count
++;
1410 /* Release a reference to VAL, which was acquired with value_incref.
1411 This function is also called to deallocate values from the value
1415 value_free (struct value
*val
)
1419 gdb_assert (val
->reference_count
> 0);
1420 val
->reference_count
--;
1421 if (val
->reference_count
> 0)
1424 /* If there's an associated parent value, drop our reference to
1426 if (val
->parent
!= NULL
)
1427 value_free (val
->parent
);
1429 if (VALUE_LVAL (val
) == lval_computed
)
1431 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1433 if (funcs
->free_closure
)
1434 funcs
->free_closure (val
);
1437 xfree (val
->contents
);
1438 VEC_free (range_s
, val
->unavailable
);
1443 /* Free all values allocated since MARK was obtained by value_mark
1444 (except for those released). */
1446 value_free_to_mark (struct value
*mark
)
1451 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1460 /* Free all the values that have been allocated (except for those released).
1461 Call after each command, successful or not.
1462 In practice this is called before each command, which is sufficient. */
1465 free_all_values (void)
1470 for (val
= all_values
; val
; val
= next
)
1480 /* Frees all the elements in a chain of values. */
1483 free_value_chain (struct value
*v
)
1489 next
= value_next (v
);
1494 /* Remove VAL from the chain all_values
1495 so it will not be freed automatically. */
1498 release_value (struct value
*val
)
1502 if (all_values
== val
)
1504 all_values
= val
->next
;
1510 for (v
= all_values
; v
; v
= v
->next
)
1514 v
->next
= val
->next
;
1522 /* If the value is not already released, release it.
1523 If the value is already released, increment its reference count.
1524 That is, this function ensures that the value is released from the
1525 value chain and that the caller owns a reference to it. */
1528 release_value_or_incref (struct value
*val
)
1533 release_value (val
);
1536 /* Release all values up to mark */
1538 value_release_to_mark (struct value
*mark
)
1543 for (val
= next
= all_values
; next
; next
= next
->next
)
1545 if (next
->next
== mark
)
1547 all_values
= next
->next
;
1557 /* Return a copy of the value ARG.
1558 It contains the same contents, for same memory address,
1559 but it's a different block of storage. */
1562 value_copy (struct value
*arg
)
1564 struct type
*encl_type
= value_enclosing_type (arg
);
1567 if (value_lazy (arg
))
1568 val
= allocate_value_lazy (encl_type
);
1570 val
= allocate_value (encl_type
);
1571 val
->type
= arg
->type
;
1572 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1573 val
->location
= arg
->location
;
1574 val
->offset
= arg
->offset
;
1575 val
->bitpos
= arg
->bitpos
;
1576 val
->bitsize
= arg
->bitsize
;
1577 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1578 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1579 val
->lazy
= arg
->lazy
;
1580 val
->optimized_out
= arg
->optimized_out
;
1581 val
->embedded_offset
= value_embedded_offset (arg
);
1582 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1583 val
->modifiable
= arg
->modifiable
;
1584 if (!value_lazy (val
))
1586 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1587 TYPE_LENGTH (value_enclosing_type (arg
)));
1590 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1591 set_value_parent (val
, arg
->parent
);
1592 if (VALUE_LVAL (val
) == lval_computed
)
1594 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1596 if (funcs
->copy_closure
)
1597 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1602 /* Return a version of ARG that is non-lvalue. */
1605 value_non_lval (struct value
*arg
)
1607 if (VALUE_LVAL (arg
) != not_lval
)
1609 struct type
*enc_type
= value_enclosing_type (arg
);
1610 struct value
*val
= allocate_value (enc_type
);
1612 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1613 TYPE_LENGTH (enc_type
));
1614 val
->type
= arg
->type
;
1615 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1616 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1623 set_value_component_location (struct value
*component
,
1624 const struct value
*whole
)
1626 if (whole
->lval
== lval_internalvar
)
1627 VALUE_LVAL (component
) = lval_internalvar_component
;
1629 VALUE_LVAL (component
) = whole
->lval
;
1631 component
->location
= whole
->location
;
1632 if (whole
->lval
== lval_computed
)
1634 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1636 if (funcs
->copy_closure
)
1637 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1642 /* Access to the value history. */
1644 /* Record a new value in the value history.
1645 Returns the absolute history index of the entry.
1646 Result of -1 indicates the value was not saved; otherwise it is the
1647 value history index of this new item. */
1650 record_latest_value (struct value
*val
)
1654 /* We don't want this value to have anything to do with the inferior anymore.
1655 In particular, "set $1 = 50" should not affect the variable from which
1656 the value was taken, and fast watchpoints should be able to assume that
1657 a value on the value history never changes. */
1658 if (value_lazy (val
))
1659 value_fetch_lazy (val
);
1660 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1661 from. This is a bit dubious, because then *&$1 does not just return $1
1662 but the current contents of that location. c'est la vie... */
1663 val
->modifiable
= 0;
1664 release_value (val
);
1666 /* Here we treat value_history_count as origin-zero
1667 and applying to the value being stored now. */
1669 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1672 struct value_history_chunk
*new
1673 = (struct value_history_chunk
*)
1675 xmalloc (sizeof (struct value_history_chunk
));
1676 memset (new->values
, 0, sizeof new->values
);
1677 new->next
= value_history_chain
;
1678 value_history_chain
= new;
1681 value_history_chain
->values
[i
] = val
;
1683 /* Now we regard value_history_count as origin-one
1684 and applying to the value just stored. */
1686 return ++value_history_count
;
1689 /* Return a copy of the value in the history with sequence number NUM. */
1692 access_value_history (int num
)
1694 struct value_history_chunk
*chunk
;
1699 absnum
+= value_history_count
;
1704 error (_("The history is empty."));
1706 error (_("There is only one value in the history."));
1708 error (_("History does not go back to $$%d."), -num
);
1710 if (absnum
> value_history_count
)
1711 error (_("History has not yet reached $%d."), absnum
);
1715 /* Now absnum is always absolute and origin zero. */
1717 chunk
= value_history_chain
;
1718 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1719 - absnum
/ VALUE_HISTORY_CHUNK
;
1721 chunk
= chunk
->next
;
1723 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1727 show_values (char *num_exp
, int from_tty
)
1735 /* "show values +" should print from the stored position.
1736 "show values <exp>" should print around value number <exp>. */
1737 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1738 num
= parse_and_eval_long (num_exp
) - 5;
1742 /* "show values" means print the last 10 values. */
1743 num
= value_history_count
- 9;
1749 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1751 struct value_print_options opts
;
1753 val
= access_value_history (i
);
1754 printf_filtered (("$%d = "), i
);
1755 get_user_print_options (&opts
);
1756 value_print (val
, gdb_stdout
, &opts
);
1757 printf_filtered (("\n"));
1760 /* The next "show values +" should start after what we just printed. */
1763 /* Hitting just return after this command should do the same thing as
1764 "show values +". If num_exp is null, this is unnecessary, since
1765 "show values +" is not useful after "show values". */
1766 if (from_tty
&& num_exp
)
1773 /* Internal variables. These are variables within the debugger
1774 that hold values assigned by debugger commands.
1775 The user refers to them with a '$' prefix
1776 that does not appear in the variable names stored internally. */
1780 struct internalvar
*next
;
1783 /* We support various different kinds of content of an internal variable.
1784 enum internalvar_kind specifies the kind, and union internalvar_data
1785 provides the data associated with this particular kind. */
1787 enum internalvar_kind
1789 /* The internal variable is empty. */
1792 /* The value of the internal variable is provided directly as
1793 a GDB value object. */
1796 /* A fresh value is computed via a call-back routine on every
1797 access to the internal variable. */
1798 INTERNALVAR_MAKE_VALUE
,
1800 /* The internal variable holds a GDB internal convenience function. */
1801 INTERNALVAR_FUNCTION
,
1803 /* The variable holds an integer value. */
1804 INTERNALVAR_INTEGER
,
1806 /* The variable holds a GDB-provided string. */
1811 union internalvar_data
1813 /* A value object used with INTERNALVAR_VALUE. */
1814 struct value
*value
;
1816 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1819 /* The functions to call. */
1820 const struct internalvar_funcs
*functions
;
1822 /* The function's user-data. */
1826 /* The internal function used with INTERNALVAR_FUNCTION. */
1829 struct internal_function
*function
;
1830 /* True if this is the canonical name for the function. */
1834 /* An integer value used with INTERNALVAR_INTEGER. */
1837 /* If type is non-NULL, it will be used as the type to generate
1838 a value for this internal variable. If type is NULL, a default
1839 integer type for the architecture is used. */
1844 /* A string value used with INTERNALVAR_STRING. */
1849 static struct internalvar
*internalvars
;
1851 /* If the variable does not already exist create it and give it the
1852 value given. If no value is given then the default is zero. */
1854 init_if_undefined_command (char* args
, int from_tty
)
1856 struct internalvar
* intvar
;
1858 /* Parse the expression - this is taken from set_command(). */
1859 struct expression
*expr
= parse_expression (args
);
1860 register struct cleanup
*old_chain
=
1861 make_cleanup (free_current_contents
, &expr
);
1863 /* Validate the expression.
1864 Was the expression an assignment?
1865 Or even an expression at all? */
1866 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1867 error (_("Init-if-undefined requires an assignment expression."));
1869 /* Extract the variable from the parsed expression.
1870 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1871 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1872 error (_("The first parameter to init-if-undefined "
1873 "should be a GDB variable."));
1874 intvar
= expr
->elts
[2].internalvar
;
1876 /* Only evaluate the expression if the lvalue is void.
1877 This may still fail if the expresssion is invalid. */
1878 if (intvar
->kind
== INTERNALVAR_VOID
)
1879 evaluate_expression (expr
);
1881 do_cleanups (old_chain
);
1885 /* Look up an internal variable with name NAME. NAME should not
1886 normally include a dollar sign.
1888 If the specified internal variable does not exist,
1889 the return value is NULL. */
1891 struct internalvar
*
1892 lookup_only_internalvar (const char *name
)
1894 struct internalvar
*var
;
1896 for (var
= internalvars
; var
; var
= var
->next
)
1897 if (strcmp (var
->name
, name
) == 0)
1903 /* Complete NAME by comparing it to the names of internal variables.
1904 Returns a vector of newly allocated strings, or NULL if no matches
1908 complete_internalvar (const char *name
)
1910 VEC (char_ptr
) *result
= NULL
;
1911 struct internalvar
*var
;
1914 len
= strlen (name
);
1916 for (var
= internalvars
; var
; var
= var
->next
)
1917 if (strncmp (var
->name
, name
, len
) == 0)
1919 char *r
= xstrdup (var
->name
);
1921 VEC_safe_push (char_ptr
, result
, r
);
1927 /* Create an internal variable with name NAME and with a void value.
1928 NAME should not normally include a dollar sign. */
1930 struct internalvar
*
1931 create_internalvar (const char *name
)
1933 struct internalvar
*var
;
1935 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1936 var
->name
= concat (name
, (char *)NULL
);
1937 var
->kind
= INTERNALVAR_VOID
;
1938 var
->next
= internalvars
;
1943 /* Create an internal variable with name NAME and register FUN as the
1944 function that value_of_internalvar uses to create a value whenever
1945 this variable is referenced. NAME should not normally include a
1946 dollar sign. DATA is passed uninterpreted to FUN when it is
1947 called. CLEANUP, if not NULL, is called when the internal variable
1948 is destroyed. It is passed DATA as its only argument. */
1950 struct internalvar
*
1951 create_internalvar_type_lazy (const char *name
,
1952 const struct internalvar_funcs
*funcs
,
1955 struct internalvar
*var
= create_internalvar (name
);
1957 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1958 var
->u
.make_value
.functions
= funcs
;
1959 var
->u
.make_value
.data
= data
;
1963 /* See documentation in value.h. */
1966 compile_internalvar_to_ax (struct internalvar
*var
,
1967 struct agent_expr
*expr
,
1968 struct axs_value
*value
)
1970 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1971 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1974 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1975 var
->u
.make_value
.data
);
1979 /* Look up an internal variable with name NAME. NAME should not
1980 normally include a dollar sign.
1982 If the specified internal variable does not exist,
1983 one is created, with a void value. */
1985 struct internalvar
*
1986 lookup_internalvar (const char *name
)
1988 struct internalvar
*var
;
1990 var
= lookup_only_internalvar (name
);
1994 return create_internalvar (name
);
1997 /* Return current value of internal variable VAR. For variables that
1998 are not inherently typed, use a value type appropriate for GDBARCH. */
2001 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2004 struct trace_state_variable
*tsv
;
2006 /* If there is a trace state variable of the same name, assume that
2007 is what we really want to see. */
2008 tsv
= find_trace_state_variable (var
->name
);
2011 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2013 if (tsv
->value_known
)
2014 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2017 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2023 case INTERNALVAR_VOID
:
2024 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2027 case INTERNALVAR_FUNCTION
:
2028 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2031 case INTERNALVAR_INTEGER
:
2032 if (!var
->u
.integer
.type
)
2033 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2034 var
->u
.integer
.val
);
2036 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2039 case INTERNALVAR_STRING
:
2040 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2041 builtin_type (gdbarch
)->builtin_char
);
2044 case INTERNALVAR_VALUE
:
2045 val
= value_copy (var
->u
.value
);
2046 if (value_lazy (val
))
2047 value_fetch_lazy (val
);
2050 case INTERNALVAR_MAKE_VALUE
:
2051 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2052 var
->u
.make_value
.data
);
2056 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2059 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2060 on this value go back to affect the original internal variable.
2062 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2063 no underlying modifyable state in the internal variable.
2065 Likewise, if the variable's value is a computed lvalue, we want
2066 references to it to produce another computed lvalue, where
2067 references and assignments actually operate through the
2068 computed value's functions.
2070 This means that internal variables with computed values
2071 behave a little differently from other internal variables:
2072 assignments to them don't just replace the previous value
2073 altogether. At the moment, this seems like the behavior we
2076 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2077 && val
->lval
!= lval_computed
)
2079 VALUE_LVAL (val
) = lval_internalvar
;
2080 VALUE_INTERNALVAR (val
) = var
;
2087 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2089 if (var
->kind
== INTERNALVAR_INTEGER
)
2091 *result
= var
->u
.integer
.val
;
2095 if (var
->kind
== INTERNALVAR_VALUE
)
2097 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2099 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2101 *result
= value_as_long (var
->u
.value
);
2110 get_internalvar_function (struct internalvar
*var
,
2111 struct internal_function
**result
)
2115 case INTERNALVAR_FUNCTION
:
2116 *result
= var
->u
.fn
.function
;
2125 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
2126 int bitsize
, struct value
*newval
)
2132 case INTERNALVAR_VALUE
:
2133 addr
= value_contents_writeable (var
->u
.value
);
2136 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2137 value_as_long (newval
), bitpos
, bitsize
);
2139 memcpy (addr
+ offset
, value_contents (newval
),
2140 TYPE_LENGTH (value_type (newval
)));
2144 /* We can never get a component of any other kind. */
2145 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2150 set_internalvar (struct internalvar
*var
, struct value
*val
)
2152 enum internalvar_kind new_kind
;
2153 union internalvar_data new_data
= { 0 };
2155 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2156 error (_("Cannot overwrite convenience function %s"), var
->name
);
2158 /* Prepare new contents. */
2159 switch (TYPE_CODE (check_typedef (value_type (val
))))
2161 case TYPE_CODE_VOID
:
2162 new_kind
= INTERNALVAR_VOID
;
2165 case TYPE_CODE_INTERNAL_FUNCTION
:
2166 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2167 new_kind
= INTERNALVAR_FUNCTION
;
2168 get_internalvar_function (VALUE_INTERNALVAR (val
),
2169 &new_data
.fn
.function
);
2170 /* Copies created here are never canonical. */
2174 new_kind
= INTERNALVAR_VALUE
;
2175 new_data
.value
= value_copy (val
);
2176 new_data
.value
->modifiable
= 1;
2178 /* Force the value to be fetched from the target now, to avoid problems
2179 later when this internalvar is referenced and the target is gone or
2181 if (value_lazy (new_data
.value
))
2182 value_fetch_lazy (new_data
.value
);
2184 /* Release the value from the value chain to prevent it from being
2185 deleted by free_all_values. From here on this function should not
2186 call error () until new_data is installed into the var->u to avoid
2188 release_value (new_data
.value
);
2192 /* Clean up old contents. */
2193 clear_internalvar (var
);
2196 var
->kind
= new_kind
;
2198 /* End code which must not call error(). */
2202 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2204 /* Clean up old contents. */
2205 clear_internalvar (var
);
2207 var
->kind
= INTERNALVAR_INTEGER
;
2208 var
->u
.integer
.type
= NULL
;
2209 var
->u
.integer
.val
= l
;
2213 set_internalvar_string (struct internalvar
*var
, const char *string
)
2215 /* Clean up old contents. */
2216 clear_internalvar (var
);
2218 var
->kind
= INTERNALVAR_STRING
;
2219 var
->u
.string
= xstrdup (string
);
2223 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2225 /* Clean up old contents. */
2226 clear_internalvar (var
);
2228 var
->kind
= INTERNALVAR_FUNCTION
;
2229 var
->u
.fn
.function
= f
;
2230 var
->u
.fn
.canonical
= 1;
2231 /* Variables installed here are always the canonical version. */
2235 clear_internalvar (struct internalvar
*var
)
2237 /* Clean up old contents. */
2240 case INTERNALVAR_VALUE
:
2241 value_free (var
->u
.value
);
2244 case INTERNALVAR_STRING
:
2245 xfree (var
->u
.string
);
2248 case INTERNALVAR_MAKE_VALUE
:
2249 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2250 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2257 /* Reset to void kind. */
2258 var
->kind
= INTERNALVAR_VOID
;
2262 internalvar_name (struct internalvar
*var
)
2267 static struct internal_function
*
2268 create_internal_function (const char *name
,
2269 internal_function_fn handler
, void *cookie
)
2271 struct internal_function
*ifn
= XNEW (struct internal_function
);
2273 ifn
->name
= xstrdup (name
);
2274 ifn
->handler
= handler
;
2275 ifn
->cookie
= cookie
;
2280 value_internal_function_name (struct value
*val
)
2282 struct internal_function
*ifn
;
2285 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2286 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2287 gdb_assert (result
);
2293 call_internal_function (struct gdbarch
*gdbarch
,
2294 const struct language_defn
*language
,
2295 struct value
*func
, int argc
, struct value
**argv
)
2297 struct internal_function
*ifn
;
2300 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2301 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2302 gdb_assert (result
);
2304 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2307 /* The 'function' command. This does nothing -- it is just a
2308 placeholder to let "help function NAME" work. This is also used as
2309 the implementation of the sub-command that is created when
2310 registering an internal function. */
2312 function_command (char *command
, int from_tty
)
2317 /* Clean up if an internal function's command is destroyed. */
2319 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2321 xfree ((char *) self
->name
);
2325 /* Add a new internal function. NAME is the name of the function; DOC
2326 is a documentation string describing the function. HANDLER is
2327 called when the function is invoked. COOKIE is an arbitrary
2328 pointer which is passed to HANDLER and is intended for "user
2331 add_internal_function (const char *name
, const char *doc
,
2332 internal_function_fn handler
, void *cookie
)
2334 struct cmd_list_element
*cmd
;
2335 struct internal_function
*ifn
;
2336 struct internalvar
*var
= lookup_internalvar (name
);
2338 ifn
= create_internal_function (name
, handler
, cookie
);
2339 set_internalvar_function (var
, ifn
);
2341 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2343 cmd
->destroyer
= function_destroyer
;
2346 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2347 prevent cycles / duplicates. */
2350 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2351 htab_t copied_types
)
2353 if (TYPE_OBJFILE (value
->type
) == objfile
)
2354 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2356 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2357 value
->enclosing_type
= copy_type_recursive (objfile
,
2358 value
->enclosing_type
,
2362 /* Likewise for internal variable VAR. */
2365 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2366 htab_t copied_types
)
2370 case INTERNALVAR_INTEGER
:
2371 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2373 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2376 case INTERNALVAR_VALUE
:
2377 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2382 /* Update the internal variables and value history when OBJFILE is
2383 discarded; we must copy the types out of the objfile. New global types
2384 will be created for every convenience variable which currently points to
2385 this objfile's types, and the convenience variables will be adjusted to
2386 use the new global types. */
2389 preserve_values (struct objfile
*objfile
)
2391 htab_t copied_types
;
2392 struct value_history_chunk
*cur
;
2393 struct internalvar
*var
;
2396 /* Create the hash table. We allocate on the objfile's obstack, since
2397 it is soon to be deleted. */
2398 copied_types
= create_copied_types_hash (objfile
);
2400 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2401 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2403 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2405 for (var
= internalvars
; var
; var
= var
->next
)
2406 preserve_one_internalvar (var
, objfile
, copied_types
);
2408 preserve_python_values (objfile
, copied_types
);
2410 htab_delete (copied_types
);
2414 show_convenience (char *ignore
, int from_tty
)
2416 struct gdbarch
*gdbarch
= get_current_arch ();
2417 struct internalvar
*var
;
2419 struct value_print_options opts
;
2421 get_user_print_options (&opts
);
2422 for (var
= internalvars
; var
; var
= var
->next
)
2424 volatile struct gdb_exception ex
;
2430 printf_filtered (("$%s = "), var
->name
);
2432 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2436 val
= value_of_internalvar (gdbarch
, var
);
2437 value_print (val
, gdb_stdout
, &opts
);
2440 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2441 printf_filtered (("\n"));
2445 /* This text does not mention convenience functions on purpose.
2446 The user can't create them except via Python, and if Python support
2447 is installed this message will never be printed ($_streq will
2449 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2450 "Convenience variables have "
2451 "names starting with \"$\";\n"
2452 "use \"set\" as in \"set "
2453 "$foo = 5\" to define them.\n"));
2457 /* Extract a value as a C number (either long or double).
2458 Knows how to convert fixed values to double, or
2459 floating values to long.
2460 Does not deallocate the value. */
2463 value_as_long (struct value
*val
)
2465 /* This coerces arrays and functions, which is necessary (e.g.
2466 in disassemble_command). It also dereferences references, which
2467 I suspect is the most logical thing to do. */
2468 val
= coerce_array (val
);
2469 return unpack_long (value_type (val
), value_contents (val
));
2473 value_as_double (struct value
*val
)
2478 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2480 error (_("Invalid floating value found in program."));
2484 /* Extract a value as a C pointer. Does not deallocate the value.
2485 Note that val's type may not actually be a pointer; value_as_long
2486 handles all the cases. */
2488 value_as_address (struct value
*val
)
2490 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2492 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2493 whether we want this to be true eventually. */
2495 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2496 non-address (e.g. argument to "signal", "info break", etc.), or
2497 for pointers to char, in which the low bits *are* significant. */
2498 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2501 /* There are several targets (IA-64, PowerPC, and others) which
2502 don't represent pointers to functions as simply the address of
2503 the function's entry point. For example, on the IA-64, a
2504 function pointer points to a two-word descriptor, generated by
2505 the linker, which contains the function's entry point, and the
2506 value the IA-64 "global pointer" register should have --- to
2507 support position-independent code. The linker generates
2508 descriptors only for those functions whose addresses are taken.
2510 On such targets, it's difficult for GDB to convert an arbitrary
2511 function address into a function pointer; it has to either find
2512 an existing descriptor for that function, or call malloc and
2513 build its own. On some targets, it is impossible for GDB to
2514 build a descriptor at all: the descriptor must contain a jump
2515 instruction; data memory cannot be executed; and code memory
2518 Upon entry to this function, if VAL is a value of type `function'
2519 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2520 value_address (val) is the address of the function. This is what
2521 you'll get if you evaluate an expression like `main'. The call
2522 to COERCE_ARRAY below actually does all the usual unary
2523 conversions, which includes converting values of type `function'
2524 to `pointer to function'. This is the challenging conversion
2525 discussed above. Then, `unpack_long' will convert that pointer
2526 back into an address.
2528 So, suppose the user types `disassemble foo' on an architecture
2529 with a strange function pointer representation, on which GDB
2530 cannot build its own descriptors, and suppose further that `foo'
2531 has no linker-built descriptor. The address->pointer conversion
2532 will signal an error and prevent the command from running, even
2533 though the next step would have been to convert the pointer
2534 directly back into the same address.
2536 The following shortcut avoids this whole mess. If VAL is a
2537 function, just return its address directly. */
2538 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2539 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2540 return value_address (val
);
2542 val
= coerce_array (val
);
2544 /* Some architectures (e.g. Harvard), map instruction and data
2545 addresses onto a single large unified address space. For
2546 instance: An architecture may consider a large integer in the
2547 range 0x10000000 .. 0x1000ffff to already represent a data
2548 addresses (hence not need a pointer to address conversion) while
2549 a small integer would still need to be converted integer to
2550 pointer to address. Just assume such architectures handle all
2551 integer conversions in a single function. */
2555 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2556 must admonish GDB hackers to make sure its behavior matches the
2557 compiler's, whenever possible.
2559 In general, I think GDB should evaluate expressions the same way
2560 the compiler does. When the user copies an expression out of
2561 their source code and hands it to a `print' command, they should
2562 get the same value the compiler would have computed. Any
2563 deviation from this rule can cause major confusion and annoyance,
2564 and needs to be justified carefully. In other words, GDB doesn't
2565 really have the freedom to do these conversions in clever and
2568 AndrewC pointed out that users aren't complaining about how GDB
2569 casts integers to pointers; they are complaining that they can't
2570 take an address from a disassembly listing and give it to `x/i'.
2571 This is certainly important.
2573 Adding an architecture method like integer_to_address() certainly
2574 makes it possible for GDB to "get it right" in all circumstances
2575 --- the target has complete control over how things get done, so
2576 people can Do The Right Thing for their target without breaking
2577 anyone else. The standard doesn't specify how integers get
2578 converted to pointers; usually, the ABI doesn't either, but
2579 ABI-specific code is a more reasonable place to handle it. */
2581 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2582 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2583 && gdbarch_integer_to_address_p (gdbarch
))
2584 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2585 value_contents (val
));
2587 return unpack_long (value_type (val
), value_contents (val
));
2591 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2592 as a long, or as a double, assuming the raw data is described
2593 by type TYPE. Knows how to convert different sizes of values
2594 and can convert between fixed and floating point. We don't assume
2595 any alignment for the raw data. Return value is in host byte order.
2597 If you want functions and arrays to be coerced to pointers, and
2598 references to be dereferenced, call value_as_long() instead.
2600 C++: It is assumed that the front-end has taken care of
2601 all matters concerning pointers to members. A pointer
2602 to member which reaches here is considered to be equivalent
2603 to an INT (or some size). After all, it is only an offset. */
2606 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2608 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2609 enum type_code code
= TYPE_CODE (type
);
2610 int len
= TYPE_LENGTH (type
);
2611 int nosign
= TYPE_UNSIGNED (type
);
2615 case TYPE_CODE_TYPEDEF
:
2616 return unpack_long (check_typedef (type
), valaddr
);
2617 case TYPE_CODE_ENUM
:
2618 case TYPE_CODE_FLAGS
:
2619 case TYPE_CODE_BOOL
:
2621 case TYPE_CODE_CHAR
:
2622 case TYPE_CODE_RANGE
:
2623 case TYPE_CODE_MEMBERPTR
:
2625 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2627 return extract_signed_integer (valaddr
, len
, byte_order
);
2630 return extract_typed_floating (valaddr
, type
);
2632 case TYPE_CODE_DECFLOAT
:
2633 /* libdecnumber has a function to convert from decimal to integer, but
2634 it doesn't work when the decimal number has a fractional part. */
2635 return decimal_to_doublest (valaddr
, len
, byte_order
);
2639 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2640 whether we want this to be true eventually. */
2641 return extract_typed_address (valaddr
, type
);
2644 error (_("Value can't be converted to integer."));
2646 return 0; /* Placate lint. */
2649 /* Return a double value from the specified type and address.
2650 INVP points to an int which is set to 0 for valid value,
2651 1 for invalid value (bad float format). In either case,
2652 the returned double is OK to use. Argument is in target
2653 format, result is in host format. */
2656 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2658 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2659 enum type_code code
;
2663 *invp
= 0; /* Assume valid. */
2664 CHECK_TYPEDEF (type
);
2665 code
= TYPE_CODE (type
);
2666 len
= TYPE_LENGTH (type
);
2667 nosign
= TYPE_UNSIGNED (type
);
2668 if (code
== TYPE_CODE_FLT
)
2670 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2671 floating-point value was valid (using the macro
2672 INVALID_FLOAT). That test/macro have been removed.
2674 It turns out that only the VAX defined this macro and then
2675 only in a non-portable way. Fixing the portability problem
2676 wouldn't help since the VAX floating-point code is also badly
2677 bit-rotten. The target needs to add definitions for the
2678 methods gdbarch_float_format and gdbarch_double_format - these
2679 exactly describe the target floating-point format. The
2680 problem here is that the corresponding floatformat_vax_f and
2681 floatformat_vax_d values these methods should be set to are
2682 also not defined either. Oops!
2684 Hopefully someone will add both the missing floatformat
2685 definitions and the new cases for floatformat_is_valid (). */
2687 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2693 return extract_typed_floating (valaddr
, type
);
2695 else if (code
== TYPE_CODE_DECFLOAT
)
2696 return decimal_to_doublest (valaddr
, len
, byte_order
);
2699 /* Unsigned -- be sure we compensate for signed LONGEST. */
2700 return (ULONGEST
) unpack_long (type
, valaddr
);
2704 /* Signed -- we are OK with unpack_long. */
2705 return unpack_long (type
, valaddr
);
2709 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2710 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2711 We don't assume any alignment for the raw data. Return value is in
2714 If you want functions and arrays to be coerced to pointers, and
2715 references to be dereferenced, call value_as_address() instead.
2717 C++: It is assumed that the front-end has taken care of
2718 all matters concerning pointers to members. A pointer
2719 to member which reaches here is considered to be equivalent
2720 to an INT (or some size). After all, it is only an offset. */
2723 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2725 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2726 whether we want this to be true eventually. */
2727 return unpack_long (type
, valaddr
);
2731 /* Get the value of the FIELDNO'th field (which must be static) of
2735 value_static_field (struct type
*type
, int fieldno
)
2737 struct value
*retval
;
2739 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2741 case FIELD_LOC_KIND_PHYSADDR
:
2742 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2743 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2745 case FIELD_LOC_KIND_PHYSNAME
:
2747 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2748 /* TYPE_FIELD_NAME (type, fieldno); */
2749 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2753 /* With some compilers, e.g. HP aCC, static data members are
2754 reported as non-debuggable symbols. */
2755 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2759 return allocate_optimized_out_value (type
);
2762 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2763 SYMBOL_VALUE_ADDRESS (msym
));
2767 retval
= value_of_variable (sym
, NULL
);
2771 gdb_assert_not_reached ("unexpected field location kind");
2777 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2778 You have to be careful here, since the size of the data area for the value
2779 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2780 than the old enclosing type, you have to allocate more space for the
2784 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2786 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2788 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2790 val
->enclosing_type
= new_encl_type
;
2793 /* Given a value ARG1 (offset by OFFSET bytes)
2794 of a struct or union type ARG_TYPE,
2795 extract and return the value of one of its (non-static) fields.
2796 FIELDNO says which field. */
2799 value_primitive_field (struct value
*arg1
, int offset
,
2800 int fieldno
, struct type
*arg_type
)
2805 CHECK_TYPEDEF (arg_type
);
2806 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2808 /* Call check_typedef on our type to make sure that, if TYPE
2809 is a TYPE_CODE_TYPEDEF, its length is set to the length
2810 of the target type instead of zero. However, we do not
2811 replace the typedef type by the target type, because we want
2812 to keep the typedef in order to be able to print the type
2813 description correctly. */
2814 check_typedef (type
);
2816 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2818 /* Handle packed fields.
2820 Create a new value for the bitfield, with bitpos and bitsize
2821 set. If possible, arrange offset and bitpos so that we can
2822 do a single aligned read of the size of the containing type.
2823 Otherwise, adjust offset to the byte containing the first
2824 bit. Assume that the address, offset, and embedded offset
2825 are sufficiently aligned. */
2827 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2828 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2830 if (arg1
->optimized_out
)
2831 v
= allocate_optimized_out_value (type
);
2834 v
= allocate_value_lazy (type
);
2835 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2836 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2837 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2838 v
->bitpos
= bitpos
% container_bitsize
;
2840 v
->bitpos
= bitpos
% 8;
2841 v
->offset
= (value_embedded_offset (arg1
)
2843 + (bitpos
- v
->bitpos
) / 8);
2844 set_value_parent (v
, arg1
);
2845 if (!value_lazy (arg1
))
2846 value_fetch_lazy (v
);
2849 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2851 /* This field is actually a base subobject, so preserve the
2852 entire object's contents for later references to virtual
2856 /* Lazy register values with offsets are not supported. */
2857 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2858 value_fetch_lazy (arg1
);
2860 /* The optimized_out flag is only set correctly once a lazy value is
2861 loaded, having just loaded some lazy values we should check the
2862 optimized out case now. */
2863 if (arg1
->optimized_out
)
2864 v
= allocate_optimized_out_value (type
);
2867 /* We special case virtual inheritance here because this
2868 requires access to the contents, which we would rather avoid
2869 for references to ordinary fields of unavailable values. */
2870 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2871 boffset
= baseclass_offset (arg_type
, fieldno
,
2872 value_contents (arg1
),
2873 value_embedded_offset (arg1
),
2874 value_address (arg1
),
2877 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2879 if (value_lazy (arg1
))
2880 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2883 v
= allocate_value (value_enclosing_type (arg1
));
2884 value_contents_copy_raw (v
, 0, arg1
, 0,
2885 TYPE_LENGTH (value_enclosing_type (arg1
)));
2888 v
->offset
= value_offset (arg1
);
2889 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2894 /* Plain old data member */
2895 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2897 /* Lazy register values with offsets are not supported. */
2898 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2899 value_fetch_lazy (arg1
);
2901 /* The optimized_out flag is only set correctly once a lazy value is
2902 loaded, having just loaded some lazy values we should check for
2903 the optimized out case now. */
2904 if (arg1
->optimized_out
)
2905 v
= allocate_optimized_out_value (type
);
2906 else if (value_lazy (arg1
))
2907 v
= allocate_value_lazy (type
);
2910 v
= allocate_value (type
);
2911 value_contents_copy_raw (v
, value_embedded_offset (v
),
2912 arg1
, value_embedded_offset (arg1
) + offset
,
2913 TYPE_LENGTH (type
));
2915 v
->offset
= (value_offset (arg1
) + offset
2916 + value_embedded_offset (arg1
));
2918 set_value_component_location (v
, arg1
);
2919 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2920 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2924 /* Given a value ARG1 of a struct or union type,
2925 extract and return the value of one of its (non-static) fields.
2926 FIELDNO says which field. */
2929 value_field (struct value
*arg1
, int fieldno
)
2931 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2934 /* Return a non-virtual function as a value.
2935 F is the list of member functions which contains the desired method.
2936 J is an index into F which provides the desired method.
2938 We only use the symbol for its address, so be happy with either a
2939 full symbol or a minimal symbol. */
2942 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2943 int j
, struct type
*type
,
2947 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2948 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2950 struct bound_minimal_symbol msym
;
2952 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2955 memset (&msym
, 0, sizeof (msym
));
2959 gdb_assert (sym
== NULL
);
2960 msym
= lookup_bound_minimal_symbol (physname
);
2961 if (msym
.minsym
== NULL
)
2965 v
= allocate_value (ftype
);
2968 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2972 /* The minimal symbol might point to a function descriptor;
2973 resolve it to the actual code address instead. */
2974 struct objfile
*objfile
= msym
.objfile
;
2975 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2977 set_value_address (v
,
2978 gdbarch_convert_from_func_ptr_addr
2979 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
.minsym
), ¤t_target
));
2984 if (type
!= value_type (*arg1p
))
2985 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2986 value_addr (*arg1p
)));
2988 /* Move the `this' pointer according to the offset.
2989 VALUE_OFFSET (*arg1p) += offset; */
2997 /* Helper function for both unpack_value_bits_as_long and
2998 unpack_bits_as_long. See those functions for more details on the
2999 interface; the only difference is that this function accepts either
3000 a NULL or a non-NULL ORIGINAL_VALUE. */
3003 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
3004 int embedded_offset
, int bitpos
, int bitsize
,
3005 const struct value
*original_value
,
3008 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3015 /* Read the minimum number of bytes required; there may not be
3016 enough bytes to read an entire ULONGEST. */
3017 CHECK_TYPEDEF (field_type
);
3019 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3021 bytes_read
= TYPE_LENGTH (field_type
);
3023 read_offset
= bitpos
/ 8;
3025 if (original_value
!= NULL
3026 && !value_bits_available (original_value
, embedded_offset
+ bitpos
,
3030 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
3031 bytes_read
, byte_order
);
3033 /* Extract bits. See comment above. */
3035 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3036 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3038 lsbcount
= (bitpos
% 8);
3041 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3042 If the field is signed, and is negative, then sign extend. */
3044 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3046 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3048 if (!TYPE_UNSIGNED (field_type
))
3050 if (val
& (valmask
^ (valmask
>> 1)))
3061 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3062 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
3063 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
3064 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
3067 Returns false if the value contents are unavailable, otherwise
3068 returns true, indicating a valid value has been stored in *RESULT.
3070 Extracting bits depends on endianness of the machine. Compute the
3071 number of least significant bits to discard. For big endian machines,
3072 we compute the total number of bits in the anonymous object, subtract
3073 off the bit count from the MSB of the object to the MSB of the
3074 bitfield, then the size of the bitfield, which leaves the LSB discard
3075 count. For little endian machines, the discard count is simply the
3076 number of bits from the LSB of the anonymous object to the LSB of the
3079 If the field is signed, we also do sign extension. */
3082 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3083 int embedded_offset
, int bitpos
, int bitsize
,
3084 const struct value
*original_value
,
3087 gdb_assert (original_value
!= NULL
);
3089 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
3090 bitpos
, bitsize
, original_value
, result
);
3094 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3095 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3096 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
3100 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
3101 int embedded_offset
, int fieldno
,
3102 const struct value
*val
, LONGEST
*result
)
3104 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3105 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3106 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3108 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
3109 bitpos
, bitsize
, val
,
3113 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3114 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3115 ORIGINAL_VALUE, which must not be NULL. See
3116 unpack_value_bits_as_long for more details. */
3119 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3120 int embedded_offset
, int fieldno
,
3121 const struct value
*val
, LONGEST
*result
)
3123 gdb_assert (val
!= NULL
);
3125 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
3126 fieldno
, val
, result
);
3129 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3130 object at VALADDR. See unpack_value_bits_as_long for more details.
3131 This function differs from unpack_value_field_as_long in that it
3132 operates without a struct value object. */
3135 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3139 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
3143 /* Return a new value with type TYPE, which is FIELDNO field of the
3144 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3145 of VAL. If the VAL's contents required to extract the bitfield
3146 from are unavailable, the new value is correspondingly marked as
3150 value_field_bitfield (struct type
*type
, int fieldno
,
3151 const gdb_byte
*valaddr
,
3152 int embedded_offset
, const struct value
*val
)
3156 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
3159 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3160 struct value
*retval
= allocate_value (field_type
);
3161 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
3166 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
3170 /* Modify the value of a bitfield. ADDR points to a block of memory in
3171 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3172 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3173 indicate which bits (in target bit order) comprise the bitfield.
3174 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3175 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3178 modify_field (struct type
*type
, gdb_byte
*addr
,
3179 LONGEST fieldval
, int bitpos
, int bitsize
)
3181 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3183 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3186 /* Normalize BITPOS. */
3190 /* If a negative fieldval fits in the field in question, chop
3191 off the sign extension bits. */
3192 if ((~fieldval
& ~(mask
>> 1)) == 0)
3195 /* Warn if value is too big to fit in the field in question. */
3196 if (0 != (fieldval
& ~mask
))
3198 /* FIXME: would like to include fieldval in the message, but
3199 we don't have a sprintf_longest. */
3200 warning (_("Value does not fit in %d bits."), bitsize
);
3202 /* Truncate it, otherwise adjoining fields may be corrupted. */
3206 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3207 false valgrind reports. */
3209 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3210 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3212 /* Shifting for bit field depends on endianness of the target machine. */
3213 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3214 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3216 oword
&= ~(mask
<< bitpos
);
3217 oword
|= fieldval
<< bitpos
;
3219 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3222 /* Pack NUM into BUF using a target format of TYPE. */
3225 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3227 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3230 type
= check_typedef (type
);
3231 len
= TYPE_LENGTH (type
);
3233 switch (TYPE_CODE (type
))
3236 case TYPE_CODE_CHAR
:
3237 case TYPE_CODE_ENUM
:
3238 case TYPE_CODE_FLAGS
:
3239 case TYPE_CODE_BOOL
:
3240 case TYPE_CODE_RANGE
:
3241 case TYPE_CODE_MEMBERPTR
:
3242 store_signed_integer (buf
, len
, byte_order
, num
);
3247 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3251 error (_("Unexpected type (%d) encountered for integer constant."),
3257 /* Pack NUM into BUF using a target format of TYPE. */
3260 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3263 enum bfd_endian byte_order
;
3265 type
= check_typedef (type
);
3266 len
= TYPE_LENGTH (type
);
3267 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3269 switch (TYPE_CODE (type
))
3272 case TYPE_CODE_CHAR
:
3273 case TYPE_CODE_ENUM
:
3274 case TYPE_CODE_FLAGS
:
3275 case TYPE_CODE_BOOL
:
3276 case TYPE_CODE_RANGE
:
3277 case TYPE_CODE_MEMBERPTR
:
3278 store_unsigned_integer (buf
, len
, byte_order
, num
);
3283 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3287 error (_("Unexpected type (%d) encountered "
3288 "for unsigned integer constant."),
3294 /* Convert C numbers into newly allocated values. */
3297 value_from_longest (struct type
*type
, LONGEST num
)
3299 struct value
*val
= allocate_value (type
);
3301 pack_long (value_contents_raw (val
), type
, num
);
3306 /* Convert C unsigned numbers into newly allocated values. */
3309 value_from_ulongest (struct type
*type
, ULONGEST num
)
3311 struct value
*val
= allocate_value (type
);
3313 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3319 /* Create a value representing a pointer of type TYPE to the address
3322 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3324 struct value
*val
= allocate_value (type
);
3326 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3331 /* Create a value of type TYPE whose contents come from VALADDR, if it
3332 is non-null, and whose memory address (in the inferior) is
3336 value_from_contents_and_address (struct type
*type
,
3337 const gdb_byte
*valaddr
,
3342 if (valaddr
== NULL
)
3343 v
= allocate_value_lazy (type
);
3345 v
= value_from_contents (type
, valaddr
);
3346 set_value_address (v
, address
);
3347 VALUE_LVAL (v
) = lval_memory
;
3351 /* Create a value of type TYPE holding the contents CONTENTS.
3352 The new value is `not_lval'. */
3355 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3357 struct value
*result
;
3359 result
= allocate_value (type
);
3360 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3365 value_from_double (struct type
*type
, DOUBLEST num
)
3367 struct value
*val
= allocate_value (type
);
3368 struct type
*base_type
= check_typedef (type
);
3369 enum type_code code
= TYPE_CODE (base_type
);
3371 if (code
== TYPE_CODE_FLT
)
3373 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3376 error (_("Unexpected type encountered for floating constant."));
3382 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3384 struct value
*val
= allocate_value (type
);
3386 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3390 /* Extract a value from the history file. Input will be of the form
3391 $digits or $$digits. See block comment above 'write_dollar_variable'
3395 value_from_history_ref (char *h
, char **endp
)
3407 /* Find length of numeral string. */
3408 for (; isdigit (h
[len
]); len
++)
3411 /* Make sure numeral string is not part of an identifier. */
3412 if (h
[len
] == '_' || isalpha (h
[len
]))
3415 /* Now collect the index value. */
3420 /* For some bizarre reason, "$$" is equivalent to "$$1",
3421 rather than to "$$0" as it ought to be! */
3426 index
= -strtol (&h
[2], endp
, 10);
3432 /* "$" is equivalent to "$0". */
3437 index
= strtol (&h
[1], endp
, 10);
3440 return access_value_history (index
);
3444 coerce_ref_if_computed (const struct value
*arg
)
3446 const struct lval_funcs
*funcs
;
3448 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3451 if (value_lval_const (arg
) != lval_computed
)
3454 funcs
= value_computed_funcs (arg
);
3455 if (funcs
->coerce_ref
== NULL
)
3458 return funcs
->coerce_ref (arg
);
3461 /* Look at value.h for description. */
3464 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3465 struct type
*original_type
,
3466 struct value
*original_value
)
3468 /* Re-adjust type. */
3469 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3471 /* Add embedding info. */
3472 set_value_enclosing_type (value
, enc_type
);
3473 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3475 /* We may be pointing to an object of some derived type. */
3476 return value_full_object (value
, NULL
, 0, 0, 0);
3480 coerce_ref (struct value
*arg
)
3482 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3483 struct value
*retval
;
3484 struct type
*enc_type
;
3486 retval
= coerce_ref_if_computed (arg
);
3490 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3493 enc_type
= check_typedef (value_enclosing_type (arg
));
3494 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3496 retval
= value_at_lazy (enc_type
,
3497 unpack_pointer (value_type (arg
),
3498 value_contents (arg
)));
3499 return readjust_indirect_value_type (retval
, enc_type
,
3500 value_type_arg_tmp
, arg
);
3504 coerce_array (struct value
*arg
)
3508 arg
= coerce_ref (arg
);
3509 type
= check_typedef (value_type (arg
));
3511 switch (TYPE_CODE (type
))
3513 case TYPE_CODE_ARRAY
:
3514 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3515 arg
= value_coerce_array (arg
);
3517 case TYPE_CODE_FUNC
:
3518 arg
= value_coerce_function (arg
);
3525 /* Return the return value convention that will be used for the
3528 enum return_value_convention
3529 struct_return_convention (struct gdbarch
*gdbarch
,
3530 struct value
*function
, struct type
*value_type
)
3532 enum type_code code
= TYPE_CODE (value_type
);
3534 if (code
== TYPE_CODE_ERROR
)
3535 error (_("Function return type unknown."));
3537 /* Probe the architecture for the return-value convention. */
3538 return gdbarch_return_value (gdbarch
, function
, value_type
,
3542 /* Return true if the function returning the specified type is using
3543 the convention of returning structures in memory (passing in the
3544 address as a hidden first parameter). */
3547 using_struct_return (struct gdbarch
*gdbarch
,
3548 struct value
*function
, struct type
*value_type
)
3550 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3551 /* A void return value is never in memory. See also corresponding
3552 code in "print_return_value". */
3555 return (struct_return_convention (gdbarch
, function
, value_type
)
3556 != RETURN_VALUE_REGISTER_CONVENTION
);
3559 /* Set the initialized field in a value struct. */
3562 set_value_initialized (struct value
*val
, int status
)
3564 val
->initialized
= status
;
3567 /* Return the initialized field in a value struct. */
3570 value_initialized (struct value
*val
)
3572 return val
->initialized
;
3575 /* Called only from the value_contents and value_contents_all()
3576 macros, if the current data for a variable needs to be loaded into
3577 value_contents(VAL). Fetches the data from the user's process, and
3578 clears the lazy flag to indicate that the data in the buffer is
3581 If the value is zero-length, we avoid calling read_memory, which
3582 would abort. We mark the value as fetched anyway -- all 0 bytes of
3585 This function returns a value because it is used in the
3586 value_contents macro as part of an expression, where a void would
3587 not work. The value is ignored. */
3590 value_fetch_lazy (struct value
*val
)
3592 gdb_assert (value_lazy (val
));
3593 allocate_value_contents (val
);
3594 if (value_bitsize (val
))
3596 /* To read a lazy bitfield, read the entire enclosing value. This
3597 prevents reading the same block of (possibly volatile) memory once
3598 per bitfield. It would be even better to read only the containing
3599 word, but we have no way to record that just specific bits of a
3600 value have been fetched. */
3601 struct type
*type
= check_typedef (value_type (val
));
3602 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3603 struct value
*parent
= value_parent (val
);
3604 LONGEST offset
= value_offset (val
);
3607 if (value_lazy (parent
))
3608 value_fetch_lazy (parent
);
3610 if (!value_bits_valid (parent
,
3611 TARGET_CHAR_BIT
* offset
+ value_bitpos (val
),
3612 value_bitsize (val
)))
3613 set_value_optimized_out (val
, 1);
3614 else if (!unpack_value_bits_as_long (value_type (val
),
3615 value_contents_for_printing (parent
),
3618 value_bitsize (val
), parent
, &num
))
3619 mark_value_bytes_unavailable (val
,
3620 value_embedded_offset (val
),
3621 TYPE_LENGTH (type
));
3623 store_signed_integer (value_contents_raw (val
), TYPE_LENGTH (type
),
3626 else if (VALUE_LVAL (val
) == lval_memory
)
3628 CORE_ADDR addr
= value_address (val
);
3629 struct type
*type
= check_typedef (value_enclosing_type (val
));
3631 if (TYPE_LENGTH (type
))
3632 read_value_memory (val
, 0, value_stack (val
),
3633 addr
, value_contents_all_raw (val
),
3634 TYPE_LENGTH (type
));
3636 else if (VALUE_LVAL (val
) == lval_register
)
3638 struct frame_info
*frame
;
3640 struct type
*type
= check_typedef (value_type (val
));
3641 struct value
*new_val
= val
, *mark
= value_mark ();
3643 /* Offsets are not supported here; lazy register values must
3644 refer to the entire register. */
3645 gdb_assert (value_offset (val
) == 0);
3647 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3649 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3651 frame
= frame_find_by_id (frame_id
);
3652 regnum
= VALUE_REGNUM (new_val
);
3654 gdb_assert (frame
!= NULL
);
3656 /* Convertible register routines are used for multi-register
3657 values and for interpretation in different types
3658 (e.g. float or int from a double register). Lazy
3659 register values should have the register's natural type,
3660 so they do not apply. */
3661 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3664 new_val
= get_frame_register_value (frame
, regnum
);
3666 /* If we get another lazy lval_register value, it means the
3667 register is found by reading it from the next frame.
3668 get_frame_register_value should never return a value with
3669 the frame id pointing to FRAME. If it does, it means we
3670 either have two consecutive frames with the same frame id
3671 in the frame chain, or some code is trying to unwind
3672 behind get_prev_frame's back (e.g., a frame unwind
3673 sniffer trying to unwind), bypassing its validations. In
3674 any case, it should always be an internal error to end up
3675 in this situation. */
3676 if (VALUE_LVAL (new_val
) == lval_register
3677 && value_lazy (new_val
)
3678 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
3679 internal_error (__FILE__
, __LINE__
,
3680 _("infinite loop while fetching a register"));
3683 /* If it's still lazy (for instance, a saved register on the
3684 stack), fetch it. */
3685 if (value_lazy (new_val
))
3686 value_fetch_lazy (new_val
);
3688 /* If the register was not saved, mark it optimized out. */
3689 if (value_optimized_out (new_val
))
3690 set_value_optimized_out (val
, 1);
3693 set_value_lazy (val
, 0);
3694 value_contents_copy (val
, value_embedded_offset (val
),
3695 new_val
, value_embedded_offset (new_val
),
3696 TYPE_LENGTH (type
));
3701 struct gdbarch
*gdbarch
;
3702 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3703 regnum
= VALUE_REGNUM (val
);
3704 gdbarch
= get_frame_arch (frame
);
3706 fprintf_unfiltered (gdb_stdlog
,
3707 "{ value_fetch_lazy "
3708 "(frame=%d,regnum=%d(%s),...) ",
3709 frame_relative_level (frame
), regnum
,
3710 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3712 fprintf_unfiltered (gdb_stdlog
, "->");
3713 if (value_optimized_out (new_val
))
3715 fprintf_unfiltered (gdb_stdlog
, " ");
3716 val_print_optimized_out (new_val
, gdb_stdlog
);
3721 const gdb_byte
*buf
= value_contents (new_val
);
3723 if (VALUE_LVAL (new_val
) == lval_register
)
3724 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3725 VALUE_REGNUM (new_val
));
3726 else if (VALUE_LVAL (new_val
) == lval_memory
)
3727 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3729 value_address (new_val
)));
3731 fprintf_unfiltered (gdb_stdlog
, " computed");
3733 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3734 fprintf_unfiltered (gdb_stdlog
, "[");
3735 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3736 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3737 fprintf_unfiltered (gdb_stdlog
, "]");
3740 fprintf_unfiltered (gdb_stdlog
, " }\n");
3743 /* Dispose of the intermediate values. This prevents
3744 watchpoints from trying to watch the saved frame pointer. */
3745 value_free_to_mark (mark
);
3747 else if (VALUE_LVAL (val
) == lval_computed
3748 && value_computed_funcs (val
)->read
!= NULL
)
3749 value_computed_funcs (val
)->read (val
);
3750 /* Don't call value_optimized_out on val, doing so would result in a
3751 recursive call back to value_fetch_lazy, instead check the
3752 optimized_out flag directly. */
3753 else if (val
->optimized_out
)
3754 /* Keep it optimized out. */;
3756 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3758 set_value_lazy (val
, 0);
3762 /* Implementation of the convenience function $_isvoid. */
3764 static struct value
*
3765 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3766 const struct language_defn
*language
,
3767 void *cookie
, int argc
, struct value
**argv
)
3772 error (_("You must provide one argument for $_isvoid."));
3774 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3776 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3780 _initialize_values (void)
3782 add_cmd ("convenience", no_class
, show_convenience
, _("\
3783 Debugger convenience (\"$foo\") variables and functions.\n\
3784 Convenience variables are created when you assign them values;\n\
3785 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3787 A few convenience variables are given values automatically:\n\
3788 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3789 \"$__\" holds the contents of the last address examined with \"x\"."
3792 Convenience functions are defined via the Python API."
3795 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3797 add_cmd ("values", no_set_class
, show_values
, _("\
3798 Elements of value history around item number IDX (or last ten)."),
3801 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3802 Initialize a convenience variable if necessary.\n\
3803 init-if-undefined VARIABLE = EXPRESSION\n\
3804 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3805 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3806 VARIABLE is already initialized."));
3808 add_prefix_cmd ("function", no_class
, function_command
, _("\
3809 Placeholder command for showing help on convenience functions."),
3810 &functionlist
, "function ", 0, &cmdlist
);
3812 add_internal_function ("_isvoid", _("\
3813 Check whether an expression is void.\n\
3814 Usage: $_isvoid (expression)\n\
3815 Return 1 if the expression is void, zero otherwise."),
3816 isvoid_internal_fn
, NULL
);