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 "extension.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 /* Register number if the value is from a register. */
222 /* Location of value (if lval). */
225 /* If lval == lval_memory, this is the address in the inferior.
226 If lval == lval_register, this is the byte offset into the
227 registers structure. */
230 /* Pointer to internal variable. */
231 struct internalvar
*internalvar
;
233 /* Pointer to xmethod worker. */
234 struct xmethod_worker
*xm_worker
;
236 /* If lval == lval_computed, this is a set of function pointers
237 to use to access and describe the value, and a closure pointer
241 /* Functions to call. */
242 const struct lval_funcs
*funcs
;
244 /* Closure for those functions to use. */
249 /* Describes offset of a value within lval of a structure in bytes.
250 If lval == lval_memory, this is an offset to the address. If
251 lval == lval_register, this is a further offset from
252 location.address within the registers structure. Note also the
253 member embedded_offset below. */
256 /* Only used for bitfields; number of bits contained in them. */
259 /* Only used for bitfields; position of start of field. For
260 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
261 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
264 /* The number of references to this value. When a value is created,
265 the value chain holds a reference, so REFERENCE_COUNT is 1. If
266 release_value is called, this value is removed from the chain but
267 the caller of release_value now has a reference to this value.
268 The caller must arrange for a call to value_free later. */
271 /* Only used for bitfields; the containing value. This allows a
272 single read from the target when displaying multiple
274 struct value
*parent
;
276 /* Frame register value is relative to. This will be described in
277 the lval enum above as "lval_register". */
278 struct frame_id frame_id
;
280 /* Type of the value. */
283 /* If a value represents a C++ object, then the `type' field gives
284 the object's compile-time type. If the object actually belongs
285 to some class derived from `type', perhaps with other base
286 classes and additional members, then `type' is just a subobject
287 of the real thing, and the full object is probably larger than
288 `type' would suggest.
290 If `type' is a dynamic class (i.e. one with a vtable), then GDB
291 can actually determine the object's run-time type by looking at
292 the run-time type information in the vtable. When this
293 information is available, we may elect to read in the entire
294 object, for several reasons:
296 - When printing the value, the user would probably rather see the
297 full object, not just the limited portion apparent from the
300 - If `type' has virtual base classes, then even printing `type'
301 alone may require reaching outside the `type' portion of the
302 object to wherever the virtual base class has been stored.
304 When we store the entire object, `enclosing_type' is the run-time
305 type -- the complete object -- and `embedded_offset' is the
306 offset of `type' within that larger type, in bytes. The
307 value_contents() macro takes `embedded_offset' into account, so
308 most GDB code continues to see the `type' portion of the value,
309 just as the inferior would.
311 If `type' is a pointer to an object, then `enclosing_type' is a
312 pointer to the object's run-time type, and `pointed_to_offset' is
313 the offset in bytes from the full object to the pointed-to object
314 -- that is, the value `embedded_offset' would have if we followed
315 the pointer and fetched the complete object. (I don't really see
316 the point. Why not just determine the run-time type when you
317 indirect, and avoid the special case? The contents don't matter
318 until you indirect anyway.)
320 If we're not doing anything fancy, `enclosing_type' is equal to
321 `type', and `embedded_offset' is zero, so everything works
323 struct type
*enclosing_type
;
325 int pointed_to_offset
;
327 /* Values are stored in a chain, so that they can be deleted easily
328 over calls to the inferior. Values assigned to internal
329 variables, put into the value history or exposed to Python are
330 taken off this list. */
333 /* Actual contents of the value. Target byte-order. NULL or not
334 valid if lazy is nonzero. */
337 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
338 rather than available, since the common and default case is for a
339 value to be available. This is filled in at value read time. The
340 unavailable ranges are tracked in bits. */
341 VEC(range_s
) *unavailable
;
345 value_bits_available (const struct value
*value
, int offset
, int length
)
347 gdb_assert (!value
->lazy
);
349 return !ranges_contain (value
->unavailable
, offset
, length
);
353 value_bytes_available (const struct value
*value
, int offset
, int length
)
355 return value_bits_available (value
,
356 offset
* TARGET_CHAR_BIT
,
357 length
* TARGET_CHAR_BIT
);
361 value_entirely_available (struct value
*value
)
363 /* We can only tell whether the whole value is available when we try
366 value_fetch_lazy (value
);
368 if (VEC_empty (range_s
, value
->unavailable
))
374 value_entirely_unavailable (struct value
*value
)
376 /* We can only tell whether the whole value is available when we try
379 value_fetch_lazy (value
);
381 if (VEC_length (range_s
, value
->unavailable
) == 1)
383 struct range
*t
= VEC_index (range_s
, value
->unavailable
, 0);
386 && t
->length
== (TARGET_CHAR_BIT
387 * TYPE_LENGTH (value_enclosing_type (value
))))
395 mark_value_bits_unavailable (struct value
*value
, int offset
, int length
)
400 /* Insert the range sorted. If there's overlap or the new range
401 would be contiguous with an existing range, merge. */
403 newr
.offset
= offset
;
404 newr
.length
= length
;
406 /* Do a binary search for the position the given range would be
407 inserted if we only considered the starting OFFSET of ranges.
408 Call that position I. Since we also have LENGTH to care for
409 (this is a range afterall), we need to check if the _previous_
410 range overlaps the I range. E.g., calling R the new range:
412 #1 - overlaps with previous
416 |---| |---| |------| ... |--|
421 In the case #1 above, the binary search would return `I=1',
422 meaning, this OFFSET should be inserted at position 1, and the
423 current position 1 should be pushed further (and become 2). But,
424 note that `0' overlaps with R, so we want to merge them.
426 A similar consideration needs to be taken if the new range would
427 be contiguous with the previous range:
429 #2 - contiguous with previous
433 |--| |---| |------| ... |--|
438 If there's no overlap with the previous range, as in:
440 #3 - not overlapping and not contiguous
444 |--| |---| |------| ... |--|
451 #4 - R is the range with lowest offset
455 |--| |---| |------| ... |--|
460 ... we just push the new range to I.
462 All the 4 cases above need to consider that the new range may
463 also overlap several of the ranges that follow, or that R may be
464 contiguous with the following range, and merge. E.g.,
466 #5 - overlapping following ranges
469 |------------------------|
470 |--| |---| |------| ... |--|
479 |--| |---| |------| ... |--|
486 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
489 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
491 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
494 ULONGEST l
= min (bef
->offset
, offset
);
495 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
501 else if (offset
== bef
->offset
+ bef
->length
)
504 bef
->length
+= length
;
510 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
516 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
519 /* Check whether the ranges following the one we've just added or
520 touched can be folded in (#5 above). */
521 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
528 /* Get the range we just touched. */
529 t
= VEC_index (range_s
, value
->unavailable
, i
);
533 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
534 if (r
->offset
<= t
->offset
+ t
->length
)
538 l
= min (t
->offset
, r
->offset
);
539 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
548 /* If we couldn't merge this one, we won't be able to
549 merge following ones either, since the ranges are
550 always sorted by OFFSET. */
555 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
560 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
562 mark_value_bits_unavailable (value
,
563 offset
* TARGET_CHAR_BIT
,
564 length
* TARGET_CHAR_BIT
);
567 /* Find the first range in RANGES that overlaps the range defined by
568 OFFSET and LENGTH, starting at element POS in the RANGES vector,
569 Returns the index into RANGES where such overlapping range was
570 found, or -1 if none was found. */
573 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
574 int offset
, int length
)
579 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
580 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
586 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
587 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
590 It must always be the case that:
591 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
593 It is assumed that memory can be accessed from:
594 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
596 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
597 / TARGET_CHAR_BIT) */
599 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
600 const gdb_byte
*ptr2
, size_t offset2_bits
,
603 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
604 == offset2_bits
% TARGET_CHAR_BIT
);
606 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
609 gdb_byte mask
, b1
, b2
;
611 /* The offset from the base pointers PTR1 and PTR2 is not a complete
612 number of bytes. A number of bits up to either the next exact
613 byte boundary, or LENGTH_BITS (which ever is sooner) will be
615 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
616 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
617 mask
= (1 << bits
) - 1;
619 if (length_bits
< bits
)
621 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
625 /* Now load the two bytes and mask off the bits we care about. */
626 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
627 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
632 /* Now update the length and offsets to take account of the bits
633 we've just compared. */
635 offset1_bits
+= bits
;
636 offset2_bits
+= bits
;
639 if (length_bits
% TARGET_CHAR_BIT
!= 0)
643 gdb_byte mask
, b1
, b2
;
645 /* The length is not an exact number of bytes. After the previous
646 IF.. block then the offsets are byte aligned, or the
647 length is zero (in which case this code is not reached). Compare
648 a number of bits at the end of the region, starting from an exact
650 bits
= length_bits
% TARGET_CHAR_BIT
;
651 o1
= offset1_bits
+ length_bits
- bits
;
652 o2
= offset2_bits
+ length_bits
- bits
;
654 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
655 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
657 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
658 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
660 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
661 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
671 /* We've now taken care of any stray "bits" at the start, or end of
672 the region to compare, the remainder can be covered with a simple
674 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
675 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
676 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
678 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
679 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
680 length_bits
/ TARGET_CHAR_BIT
);
683 /* Length is zero, regions match. */
687 /* Helper function for value_available_contents_eq. The only difference is
688 that this function is bit rather than byte based.
690 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits with
691 LENGTH bits of VAL2's contents starting at OFFSET2 bits. Return true
692 if the available bits match. */
695 value_available_contents_bits_eq (const struct value
*val1
, int offset1
,
696 const struct value
*val2
, int offset2
,
699 int idx1
= 0, idx2
= 0;
701 /* See function description in value.h. */
702 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
710 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
712 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
715 /* The usual case is for both values to be completely available. */
716 if (idx1
== -1 && idx2
== -1)
717 return (memcmp_with_bit_offsets (val1
->contents
, offset1
,
718 val2
->contents
, offset2
,
720 /* The contents only match equal if the available set matches as
722 else if (idx1
== -1 || idx2
== -1)
725 gdb_assert (idx1
!= -1 && idx2
!= -1);
727 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
728 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
730 /* Get the unavailable windows intersected by the incoming
731 ranges. The first and last ranges that overlap the argument
732 range may be wider than said incoming arguments ranges. */
733 l1
= max (offset1
, r1
->offset
);
734 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
736 l2
= max (offset2
, r2
->offset
);
737 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
739 /* Make them relative to the respective start offsets, so we can
740 compare them for equality. */
747 /* Different availability, no match. */
748 if (l1
!= l2
|| h1
!= h2
)
751 /* Compare the _available_ contents. */
752 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
753 val2
->contents
, offset2
, l1
) != 0)
765 value_available_contents_eq (const struct value
*val1
, int offset1
,
766 const struct value
*val2
, int offset2
,
769 return value_available_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
770 val2
, offset2
* TARGET_CHAR_BIT
,
771 length
* TARGET_CHAR_BIT
);
774 /* Prototypes for local functions. */
776 static void show_values (char *, int);
778 static void show_convenience (char *, int);
781 /* The value-history records all the values printed
782 by print commands during this session. Each chunk
783 records 60 consecutive values. The first chunk on
784 the chain records the most recent values.
785 The total number of values is in value_history_count. */
787 #define VALUE_HISTORY_CHUNK 60
789 struct value_history_chunk
791 struct value_history_chunk
*next
;
792 struct value
*values
[VALUE_HISTORY_CHUNK
];
795 /* Chain of chunks now in use. */
797 static struct value_history_chunk
*value_history_chain
;
799 static int value_history_count
; /* Abs number of last entry stored. */
802 /* List of all value objects currently allocated
803 (except for those released by calls to release_value)
804 This is so they can be freed after each command. */
806 static struct value
*all_values
;
808 /* Allocate a lazy value for type TYPE. Its actual content is
809 "lazily" allocated too: the content field of the return value is
810 NULL; it will be allocated when it is fetched from the target. */
813 allocate_value_lazy (struct type
*type
)
817 /* Call check_typedef on our type to make sure that, if TYPE
818 is a TYPE_CODE_TYPEDEF, its length is set to the length
819 of the target type instead of zero. However, we do not
820 replace the typedef type by the target type, because we want
821 to keep the typedef in order to be able to set the VAL's type
822 description correctly. */
823 check_typedef (type
);
825 val
= (struct value
*) xzalloc (sizeof (struct value
));
826 val
->contents
= NULL
;
827 val
->next
= all_values
;
830 val
->enclosing_type
= type
;
831 VALUE_LVAL (val
) = not_lval
;
832 val
->location
.address
= 0;
833 VALUE_FRAME_ID (val
) = null_frame_id
;
837 VALUE_REGNUM (val
) = -1;
839 val
->optimized_out
= 0;
840 val
->embedded_offset
= 0;
841 val
->pointed_to_offset
= 0;
843 val
->initialized
= 1; /* Default to initialized. */
845 /* Values start out on the all_values chain. */
846 val
->reference_count
= 1;
851 /* Allocate the contents of VAL if it has not been allocated yet. */
854 allocate_value_contents (struct value
*val
)
857 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
860 /* Allocate a value and its contents for type TYPE. */
863 allocate_value (struct type
*type
)
865 struct value
*val
= allocate_value_lazy (type
);
867 allocate_value_contents (val
);
872 /* Allocate a value that has the correct length
873 for COUNT repetitions of type TYPE. */
876 allocate_repeat_value (struct type
*type
, int count
)
878 int low_bound
= current_language
->string_lower_bound
; /* ??? */
879 /* FIXME-type-allocation: need a way to free this type when we are
881 struct type
*array_type
882 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
884 return allocate_value (array_type
);
888 allocate_computed_value (struct type
*type
,
889 const struct lval_funcs
*funcs
,
892 struct value
*v
= allocate_value_lazy (type
);
894 VALUE_LVAL (v
) = lval_computed
;
895 v
->location
.computed
.funcs
= funcs
;
896 v
->location
.computed
.closure
= closure
;
901 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
904 allocate_optimized_out_value (struct type
*type
)
906 struct value
*retval
= allocate_value_lazy (type
);
908 set_value_optimized_out (retval
, 1);
909 set_value_lazy (retval
, 0);
913 /* Accessor methods. */
916 value_next (struct value
*value
)
922 value_type (const struct value
*value
)
927 deprecated_set_value_type (struct value
*value
, struct type
*type
)
933 value_offset (const struct value
*value
)
935 return value
->offset
;
938 set_value_offset (struct value
*value
, int offset
)
940 value
->offset
= offset
;
944 value_bitpos (const struct value
*value
)
946 return value
->bitpos
;
949 set_value_bitpos (struct value
*value
, int bit
)
955 value_bitsize (const struct value
*value
)
957 return value
->bitsize
;
960 set_value_bitsize (struct value
*value
, int bit
)
962 value
->bitsize
= bit
;
966 value_parent (struct value
*value
)
968 return value
->parent
;
974 set_value_parent (struct value
*value
, struct value
*parent
)
976 struct value
*old
= value
->parent
;
978 value
->parent
= parent
;
980 value_incref (parent
);
985 value_contents_raw (struct value
*value
)
987 allocate_value_contents (value
);
988 return value
->contents
+ value
->embedded_offset
;
992 value_contents_all_raw (struct value
*value
)
994 allocate_value_contents (value
);
995 return value
->contents
;
999 value_enclosing_type (struct value
*value
)
1001 return value
->enclosing_type
;
1004 /* Look at value.h for description. */
1007 value_actual_type (struct value
*value
, int resolve_simple_types
,
1008 int *real_type_found
)
1010 struct value_print_options opts
;
1011 struct type
*result
;
1013 get_user_print_options (&opts
);
1015 if (real_type_found
)
1016 *real_type_found
= 0;
1017 result
= value_type (value
);
1018 if (opts
.objectprint
)
1020 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1021 fetch its rtti type. */
1022 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
1023 || TYPE_CODE (result
) == TYPE_CODE_REF
)
1024 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1025 == TYPE_CODE_STRUCT
)
1027 struct type
*real_type
;
1029 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1032 if (real_type_found
)
1033 *real_type_found
= 1;
1037 else if (resolve_simple_types
)
1039 if (real_type_found
)
1040 *real_type_found
= 1;
1041 result
= value_enclosing_type (value
);
1049 error_value_optimized_out (void)
1051 error (_("value has been optimized out"));
1055 require_not_optimized_out (const struct value
*value
)
1057 if (value
->optimized_out
)
1059 if (value
->lval
== lval_register
)
1060 error (_("register has not been saved in frame"));
1062 error_value_optimized_out ();
1067 require_available (const struct value
*value
)
1069 if (!VEC_empty (range_s
, value
->unavailable
))
1070 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1074 value_contents_for_printing (struct value
*value
)
1077 value_fetch_lazy (value
);
1078 return value
->contents
;
1082 value_contents_for_printing_const (const struct value
*value
)
1084 gdb_assert (!value
->lazy
);
1085 return value
->contents
;
1089 value_contents_all (struct value
*value
)
1091 const gdb_byte
*result
= value_contents_for_printing (value
);
1092 require_not_optimized_out (value
);
1093 require_available (value
);
1097 /* Copy LENGTH bytes of SRC value's (all) contents
1098 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1099 contents, starting at DST_OFFSET. If unavailable contents are
1100 being copied from SRC, the corresponding DST contents are marked
1101 unavailable accordingly. Neither DST nor SRC may be lazy
1104 It is assumed the contents of DST in the [DST_OFFSET,
1105 DST_OFFSET+LENGTH) range are wholly available. */
1108 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
1109 struct value
*src
, int src_offset
, int length
)
1113 int src_bit_offset
, dst_bit_offset
, bit_length
;
1115 /* A lazy DST would make that this copy operation useless, since as
1116 soon as DST's contents were un-lazied (by a later value_contents
1117 call, say), the contents would be overwritten. A lazy SRC would
1118 mean we'd be copying garbage. */
1119 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1121 /* The overwritten DST range gets unavailability ORed in, not
1122 replaced. Make sure to remember to implement replacing if it
1123 turns out actually necessary. */
1124 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1126 /* Copy the data. */
1127 memcpy (value_contents_all_raw (dst
) + dst_offset
,
1128 value_contents_all_raw (src
) + src_offset
,
1131 /* Copy the meta-data, adjusted. */
1132 src_bit_offset
= src_offset
* TARGET_CHAR_BIT
;
1133 dst_bit_offset
= dst_offset
* TARGET_CHAR_BIT
;
1134 bit_length
= length
* TARGET_CHAR_BIT
;
1135 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
1139 l
= max (r
->offset
, src_bit_offset
);
1140 h
= min (r
->offset
+ r
->length
, src_bit_offset
+ bit_length
);
1143 mark_value_bits_unavailable (dst
,
1144 dst_bit_offset
+ (l
- src_bit_offset
),
1149 /* Copy LENGTH bytes of SRC value's (all) contents
1150 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1151 (all) contents, starting at DST_OFFSET. If unavailable contents
1152 are being copied from SRC, the corresponding DST contents are
1153 marked unavailable accordingly. DST must not be lazy. If SRC is
1154 lazy, it will be fetched now. If SRC is not valid (is optimized
1155 out), an error is thrown.
1157 It is assumed the contents of DST in the [DST_OFFSET,
1158 DST_OFFSET+LENGTH) range are wholly available. */
1161 value_contents_copy (struct value
*dst
, int dst_offset
,
1162 struct value
*src
, int src_offset
, int length
)
1164 require_not_optimized_out (src
);
1167 value_fetch_lazy (src
);
1169 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1173 value_lazy (struct value
*value
)
1179 set_value_lazy (struct value
*value
, int val
)
1185 value_stack (struct value
*value
)
1187 return value
->stack
;
1191 set_value_stack (struct value
*value
, int val
)
1197 value_contents (struct value
*value
)
1199 const gdb_byte
*result
= value_contents_writeable (value
);
1200 require_not_optimized_out (value
);
1201 require_available (value
);
1206 value_contents_writeable (struct value
*value
)
1209 value_fetch_lazy (value
);
1210 return value_contents_raw (value
);
1214 value_optimized_out (struct value
*value
)
1216 /* We can only know if a value is optimized out once we have tried to
1218 if (!value
->optimized_out
&& value
->lazy
)
1219 value_fetch_lazy (value
);
1221 return value
->optimized_out
;
1225 value_optimized_out_const (const struct value
*value
)
1227 return value
->optimized_out
;
1231 set_value_optimized_out (struct value
*value
, int val
)
1233 value
->optimized_out
= val
;
1237 value_entirely_optimized_out (const struct value
*value
)
1239 if (!value
->optimized_out
)
1241 if (value
->lval
!= lval_computed
1242 || !value
->location
.computed
.funcs
->check_any_valid
)
1244 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1248 value_bits_valid (const struct value
*value
, int offset
, int length
)
1250 if (!value
->optimized_out
)
1252 if (value
->lval
!= lval_computed
1253 || !value
->location
.computed
.funcs
->check_validity
)
1255 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1260 value_bits_synthetic_pointer (const struct value
*value
,
1261 int offset
, int length
)
1263 if (value
->lval
!= lval_computed
1264 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1266 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1272 value_embedded_offset (struct value
*value
)
1274 return value
->embedded_offset
;
1278 set_value_embedded_offset (struct value
*value
, int val
)
1280 value
->embedded_offset
= val
;
1284 value_pointed_to_offset (struct value
*value
)
1286 return value
->pointed_to_offset
;
1290 set_value_pointed_to_offset (struct value
*value
, int val
)
1292 value
->pointed_to_offset
= val
;
1295 const struct lval_funcs
*
1296 value_computed_funcs (const struct value
*v
)
1298 gdb_assert (value_lval_const (v
) == lval_computed
);
1300 return v
->location
.computed
.funcs
;
1304 value_computed_closure (const struct value
*v
)
1306 gdb_assert (v
->lval
== lval_computed
);
1308 return v
->location
.computed
.closure
;
1312 deprecated_value_lval_hack (struct value
*value
)
1314 return &value
->lval
;
1318 value_lval_const (const struct value
*value
)
1324 value_address (const struct value
*value
)
1326 if (value
->lval
== lval_internalvar
1327 || value
->lval
== lval_internalvar_component
1328 || value
->lval
== lval_xcallable
)
1330 if (value
->parent
!= NULL
)
1331 return value_address (value
->parent
) + value
->offset
;
1333 return value
->location
.address
+ value
->offset
;
1337 value_raw_address (struct value
*value
)
1339 if (value
->lval
== lval_internalvar
1340 || value
->lval
== lval_internalvar_component
1341 || value
->lval
== lval_xcallable
)
1343 return value
->location
.address
;
1347 set_value_address (struct value
*value
, CORE_ADDR addr
)
1349 gdb_assert (value
->lval
!= lval_internalvar
1350 && value
->lval
!= lval_internalvar_component
1351 && value
->lval
!= lval_xcallable
);
1352 value
->location
.address
= addr
;
1355 struct internalvar
**
1356 deprecated_value_internalvar_hack (struct value
*value
)
1358 return &value
->location
.internalvar
;
1362 deprecated_value_frame_id_hack (struct value
*value
)
1364 return &value
->frame_id
;
1368 deprecated_value_regnum_hack (struct value
*value
)
1370 return &value
->regnum
;
1374 deprecated_value_modifiable (struct value
*value
)
1376 return value
->modifiable
;
1379 /* Return a mark in the value chain. All values allocated after the
1380 mark is obtained (except for those released) are subject to being freed
1381 if a subsequent value_free_to_mark is passed the mark. */
1388 /* Take a reference to VAL. VAL will not be deallocated until all
1389 references are released. */
1392 value_incref (struct value
*val
)
1394 val
->reference_count
++;
1397 /* Release a reference to VAL, which was acquired with value_incref.
1398 This function is also called to deallocate values from the value
1402 value_free (struct value
*val
)
1406 gdb_assert (val
->reference_count
> 0);
1407 val
->reference_count
--;
1408 if (val
->reference_count
> 0)
1411 /* If there's an associated parent value, drop our reference to
1413 if (val
->parent
!= NULL
)
1414 value_free (val
->parent
);
1416 if (VALUE_LVAL (val
) == lval_computed
)
1418 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1420 if (funcs
->free_closure
)
1421 funcs
->free_closure (val
);
1423 else if (VALUE_LVAL (val
) == lval_xcallable
)
1424 free_xmethod_worker (val
->location
.xm_worker
);
1426 xfree (val
->contents
);
1427 VEC_free (range_s
, val
->unavailable
);
1432 /* Free all values allocated since MARK was obtained by value_mark
1433 (except for those released). */
1435 value_free_to_mark (struct value
*mark
)
1440 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1449 /* Free all the values that have been allocated (except for those released).
1450 Call after each command, successful or not.
1451 In practice this is called before each command, which is sufficient. */
1454 free_all_values (void)
1459 for (val
= all_values
; val
; val
= next
)
1469 /* Frees all the elements in a chain of values. */
1472 free_value_chain (struct value
*v
)
1478 next
= value_next (v
);
1483 /* Remove VAL from the chain all_values
1484 so it will not be freed automatically. */
1487 release_value (struct value
*val
)
1491 if (all_values
== val
)
1493 all_values
= val
->next
;
1499 for (v
= all_values
; v
; v
= v
->next
)
1503 v
->next
= val
->next
;
1511 /* If the value is not already released, release it.
1512 If the value is already released, increment its reference count.
1513 That is, this function ensures that the value is released from the
1514 value chain and that the caller owns a reference to it. */
1517 release_value_or_incref (struct value
*val
)
1522 release_value (val
);
1525 /* Release all values up to mark */
1527 value_release_to_mark (struct value
*mark
)
1532 for (val
= next
= all_values
; next
; next
= next
->next
)
1534 if (next
->next
== mark
)
1536 all_values
= next
->next
;
1546 /* Return a copy of the value ARG.
1547 It contains the same contents, for same memory address,
1548 but it's a different block of storage. */
1551 value_copy (struct value
*arg
)
1553 struct type
*encl_type
= value_enclosing_type (arg
);
1556 if (value_lazy (arg
))
1557 val
= allocate_value_lazy (encl_type
);
1559 val
= allocate_value (encl_type
);
1560 val
->type
= arg
->type
;
1561 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1562 val
->location
= arg
->location
;
1563 val
->offset
= arg
->offset
;
1564 val
->bitpos
= arg
->bitpos
;
1565 val
->bitsize
= arg
->bitsize
;
1566 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1567 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1568 val
->lazy
= arg
->lazy
;
1569 val
->optimized_out
= arg
->optimized_out
;
1570 val
->embedded_offset
= value_embedded_offset (arg
);
1571 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1572 val
->modifiable
= arg
->modifiable
;
1573 if (!value_lazy (val
))
1575 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1576 TYPE_LENGTH (value_enclosing_type (arg
)));
1579 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1580 set_value_parent (val
, arg
->parent
);
1581 if (VALUE_LVAL (val
) == lval_computed
)
1583 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1585 if (funcs
->copy_closure
)
1586 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1591 /* Return a version of ARG that is non-lvalue. */
1594 value_non_lval (struct value
*arg
)
1596 if (VALUE_LVAL (arg
) != not_lval
)
1598 struct type
*enc_type
= value_enclosing_type (arg
);
1599 struct value
*val
= allocate_value (enc_type
);
1601 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1602 TYPE_LENGTH (enc_type
));
1603 val
->type
= arg
->type
;
1604 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1605 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1612 set_value_component_location (struct value
*component
,
1613 const struct value
*whole
)
1615 gdb_assert (whole
->lval
!= lval_xcallable
);
1617 if (whole
->lval
== lval_internalvar
)
1618 VALUE_LVAL (component
) = lval_internalvar_component
;
1620 VALUE_LVAL (component
) = whole
->lval
;
1622 component
->location
= whole
->location
;
1623 if (whole
->lval
== lval_computed
)
1625 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1627 if (funcs
->copy_closure
)
1628 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1633 /* Access to the value history. */
1635 /* Record a new value in the value history.
1636 Returns the absolute history index of the entry. */
1639 record_latest_value (struct value
*val
)
1643 /* We don't want this value to have anything to do with the inferior anymore.
1644 In particular, "set $1 = 50" should not affect the variable from which
1645 the value was taken, and fast watchpoints should be able to assume that
1646 a value on the value history never changes. */
1647 if (value_lazy (val
))
1648 value_fetch_lazy (val
);
1649 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1650 from. This is a bit dubious, because then *&$1 does not just return $1
1651 but the current contents of that location. c'est la vie... */
1652 val
->modifiable
= 0;
1654 /* The value may have already been released, in which case we're adding a
1655 new reference for its entry in the history. That is why we call
1656 release_value_or_incref here instead of release_value. */
1657 release_value_or_incref (val
);
1659 /* Here we treat value_history_count as origin-zero
1660 and applying to the value being stored now. */
1662 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1665 struct value_history_chunk
*new
1666 = (struct value_history_chunk
*)
1668 xmalloc (sizeof (struct value_history_chunk
));
1669 memset (new->values
, 0, sizeof new->values
);
1670 new->next
= value_history_chain
;
1671 value_history_chain
= new;
1674 value_history_chain
->values
[i
] = val
;
1676 /* Now we regard value_history_count as origin-one
1677 and applying to the value just stored. */
1679 return ++value_history_count
;
1682 /* Return a copy of the value in the history with sequence number NUM. */
1685 access_value_history (int num
)
1687 struct value_history_chunk
*chunk
;
1692 absnum
+= value_history_count
;
1697 error (_("The history is empty."));
1699 error (_("There is only one value in the history."));
1701 error (_("History does not go back to $$%d."), -num
);
1703 if (absnum
> value_history_count
)
1704 error (_("History has not yet reached $%d."), absnum
);
1708 /* Now absnum is always absolute and origin zero. */
1710 chunk
= value_history_chain
;
1711 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1712 - absnum
/ VALUE_HISTORY_CHUNK
;
1714 chunk
= chunk
->next
;
1716 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1720 show_values (char *num_exp
, int from_tty
)
1728 /* "show values +" should print from the stored position.
1729 "show values <exp>" should print around value number <exp>. */
1730 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1731 num
= parse_and_eval_long (num_exp
) - 5;
1735 /* "show values" means print the last 10 values. */
1736 num
= value_history_count
- 9;
1742 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1744 struct value_print_options opts
;
1746 val
= access_value_history (i
);
1747 printf_filtered (("$%d = "), i
);
1748 get_user_print_options (&opts
);
1749 value_print (val
, gdb_stdout
, &opts
);
1750 printf_filtered (("\n"));
1753 /* The next "show values +" should start after what we just printed. */
1756 /* Hitting just return after this command should do the same thing as
1757 "show values +". If num_exp is null, this is unnecessary, since
1758 "show values +" is not useful after "show values". */
1759 if (from_tty
&& num_exp
)
1766 /* Internal variables. These are variables within the debugger
1767 that hold values assigned by debugger commands.
1768 The user refers to them with a '$' prefix
1769 that does not appear in the variable names stored internally. */
1773 struct internalvar
*next
;
1776 /* We support various different kinds of content of an internal variable.
1777 enum internalvar_kind specifies the kind, and union internalvar_data
1778 provides the data associated with this particular kind. */
1780 enum internalvar_kind
1782 /* The internal variable is empty. */
1785 /* The value of the internal variable is provided directly as
1786 a GDB value object. */
1789 /* A fresh value is computed via a call-back routine on every
1790 access to the internal variable. */
1791 INTERNALVAR_MAKE_VALUE
,
1793 /* The internal variable holds a GDB internal convenience function. */
1794 INTERNALVAR_FUNCTION
,
1796 /* The variable holds an integer value. */
1797 INTERNALVAR_INTEGER
,
1799 /* The variable holds a GDB-provided string. */
1804 union internalvar_data
1806 /* A value object used with INTERNALVAR_VALUE. */
1807 struct value
*value
;
1809 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1812 /* The functions to call. */
1813 const struct internalvar_funcs
*functions
;
1815 /* The function's user-data. */
1819 /* The internal function used with INTERNALVAR_FUNCTION. */
1822 struct internal_function
*function
;
1823 /* True if this is the canonical name for the function. */
1827 /* An integer value used with INTERNALVAR_INTEGER. */
1830 /* If type is non-NULL, it will be used as the type to generate
1831 a value for this internal variable. If type is NULL, a default
1832 integer type for the architecture is used. */
1837 /* A string value used with INTERNALVAR_STRING. */
1842 static struct internalvar
*internalvars
;
1844 /* If the variable does not already exist create it and give it the
1845 value given. If no value is given then the default is zero. */
1847 init_if_undefined_command (char* args
, int from_tty
)
1849 struct internalvar
* intvar
;
1851 /* Parse the expression - this is taken from set_command(). */
1852 struct expression
*expr
= parse_expression (args
);
1853 register struct cleanup
*old_chain
=
1854 make_cleanup (free_current_contents
, &expr
);
1856 /* Validate the expression.
1857 Was the expression an assignment?
1858 Or even an expression at all? */
1859 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1860 error (_("Init-if-undefined requires an assignment expression."));
1862 /* Extract the variable from the parsed expression.
1863 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1864 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1865 error (_("The first parameter to init-if-undefined "
1866 "should be a GDB variable."));
1867 intvar
= expr
->elts
[2].internalvar
;
1869 /* Only evaluate the expression if the lvalue is void.
1870 This may still fail if the expresssion is invalid. */
1871 if (intvar
->kind
== INTERNALVAR_VOID
)
1872 evaluate_expression (expr
);
1874 do_cleanups (old_chain
);
1878 /* Look up an internal variable with name NAME. NAME should not
1879 normally include a dollar sign.
1881 If the specified internal variable does not exist,
1882 the return value is NULL. */
1884 struct internalvar
*
1885 lookup_only_internalvar (const char *name
)
1887 struct internalvar
*var
;
1889 for (var
= internalvars
; var
; var
= var
->next
)
1890 if (strcmp (var
->name
, name
) == 0)
1896 /* Complete NAME by comparing it to the names of internal variables.
1897 Returns a vector of newly allocated strings, or NULL if no matches
1901 complete_internalvar (const char *name
)
1903 VEC (char_ptr
) *result
= NULL
;
1904 struct internalvar
*var
;
1907 len
= strlen (name
);
1909 for (var
= internalvars
; var
; var
= var
->next
)
1910 if (strncmp (var
->name
, name
, len
) == 0)
1912 char *r
= xstrdup (var
->name
);
1914 VEC_safe_push (char_ptr
, result
, r
);
1920 /* Create an internal variable with name NAME and with a void value.
1921 NAME should not normally include a dollar sign. */
1923 struct internalvar
*
1924 create_internalvar (const char *name
)
1926 struct internalvar
*var
;
1928 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1929 var
->name
= concat (name
, (char *)NULL
);
1930 var
->kind
= INTERNALVAR_VOID
;
1931 var
->next
= internalvars
;
1936 /* Create an internal variable with name NAME and register FUN as the
1937 function that value_of_internalvar uses to create a value whenever
1938 this variable is referenced. NAME should not normally include a
1939 dollar sign. DATA is passed uninterpreted to FUN when it is
1940 called. CLEANUP, if not NULL, is called when the internal variable
1941 is destroyed. It is passed DATA as its only argument. */
1943 struct internalvar
*
1944 create_internalvar_type_lazy (const char *name
,
1945 const struct internalvar_funcs
*funcs
,
1948 struct internalvar
*var
= create_internalvar (name
);
1950 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1951 var
->u
.make_value
.functions
= funcs
;
1952 var
->u
.make_value
.data
= data
;
1956 /* See documentation in value.h. */
1959 compile_internalvar_to_ax (struct internalvar
*var
,
1960 struct agent_expr
*expr
,
1961 struct axs_value
*value
)
1963 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1964 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1967 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1968 var
->u
.make_value
.data
);
1972 /* Look up an internal variable with name NAME. NAME should not
1973 normally include a dollar sign.
1975 If the specified internal variable does not exist,
1976 one is created, with a void value. */
1978 struct internalvar
*
1979 lookup_internalvar (const char *name
)
1981 struct internalvar
*var
;
1983 var
= lookup_only_internalvar (name
);
1987 return create_internalvar (name
);
1990 /* Return current value of internal variable VAR. For variables that
1991 are not inherently typed, use a value type appropriate for GDBARCH. */
1994 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1997 struct trace_state_variable
*tsv
;
1999 /* If there is a trace state variable of the same name, assume that
2000 is what we really want to see. */
2001 tsv
= find_trace_state_variable (var
->name
);
2004 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2006 if (tsv
->value_known
)
2007 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2010 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2016 case INTERNALVAR_VOID
:
2017 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2020 case INTERNALVAR_FUNCTION
:
2021 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2024 case INTERNALVAR_INTEGER
:
2025 if (!var
->u
.integer
.type
)
2026 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2027 var
->u
.integer
.val
);
2029 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2032 case INTERNALVAR_STRING
:
2033 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2034 builtin_type (gdbarch
)->builtin_char
);
2037 case INTERNALVAR_VALUE
:
2038 val
= value_copy (var
->u
.value
);
2039 if (value_lazy (val
))
2040 value_fetch_lazy (val
);
2043 case INTERNALVAR_MAKE_VALUE
:
2044 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2045 var
->u
.make_value
.data
);
2049 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2052 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2053 on this value go back to affect the original internal variable.
2055 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2056 no underlying modifyable state in the internal variable.
2058 Likewise, if the variable's value is a computed lvalue, we want
2059 references to it to produce another computed lvalue, where
2060 references and assignments actually operate through the
2061 computed value's functions.
2063 This means that internal variables with computed values
2064 behave a little differently from other internal variables:
2065 assignments to them don't just replace the previous value
2066 altogether. At the moment, this seems like the behavior we
2069 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2070 && val
->lval
!= lval_computed
)
2072 VALUE_LVAL (val
) = lval_internalvar
;
2073 VALUE_INTERNALVAR (val
) = var
;
2080 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2082 if (var
->kind
== INTERNALVAR_INTEGER
)
2084 *result
= var
->u
.integer
.val
;
2088 if (var
->kind
== INTERNALVAR_VALUE
)
2090 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2092 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2094 *result
= value_as_long (var
->u
.value
);
2103 get_internalvar_function (struct internalvar
*var
,
2104 struct internal_function
**result
)
2108 case INTERNALVAR_FUNCTION
:
2109 *result
= var
->u
.fn
.function
;
2118 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
2119 int bitsize
, struct value
*newval
)
2125 case INTERNALVAR_VALUE
:
2126 addr
= value_contents_writeable (var
->u
.value
);
2129 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2130 value_as_long (newval
), bitpos
, bitsize
);
2132 memcpy (addr
+ offset
, value_contents (newval
),
2133 TYPE_LENGTH (value_type (newval
)));
2137 /* We can never get a component of any other kind. */
2138 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2143 set_internalvar (struct internalvar
*var
, struct value
*val
)
2145 enum internalvar_kind new_kind
;
2146 union internalvar_data new_data
= { 0 };
2148 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2149 error (_("Cannot overwrite convenience function %s"), var
->name
);
2151 /* Prepare new contents. */
2152 switch (TYPE_CODE (check_typedef (value_type (val
))))
2154 case TYPE_CODE_VOID
:
2155 new_kind
= INTERNALVAR_VOID
;
2158 case TYPE_CODE_INTERNAL_FUNCTION
:
2159 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2160 new_kind
= INTERNALVAR_FUNCTION
;
2161 get_internalvar_function (VALUE_INTERNALVAR (val
),
2162 &new_data
.fn
.function
);
2163 /* Copies created here are never canonical. */
2167 new_kind
= INTERNALVAR_VALUE
;
2168 new_data
.value
= value_copy (val
);
2169 new_data
.value
->modifiable
= 1;
2171 /* Force the value to be fetched from the target now, to avoid problems
2172 later when this internalvar is referenced and the target is gone or
2174 if (value_lazy (new_data
.value
))
2175 value_fetch_lazy (new_data
.value
);
2177 /* Release the value from the value chain to prevent it from being
2178 deleted by free_all_values. From here on this function should not
2179 call error () until new_data is installed into the var->u to avoid
2181 release_value (new_data
.value
);
2185 /* Clean up old contents. */
2186 clear_internalvar (var
);
2189 var
->kind
= new_kind
;
2191 /* End code which must not call error(). */
2195 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2197 /* Clean up old contents. */
2198 clear_internalvar (var
);
2200 var
->kind
= INTERNALVAR_INTEGER
;
2201 var
->u
.integer
.type
= NULL
;
2202 var
->u
.integer
.val
= l
;
2206 set_internalvar_string (struct internalvar
*var
, const char *string
)
2208 /* Clean up old contents. */
2209 clear_internalvar (var
);
2211 var
->kind
= INTERNALVAR_STRING
;
2212 var
->u
.string
= xstrdup (string
);
2216 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2218 /* Clean up old contents. */
2219 clear_internalvar (var
);
2221 var
->kind
= INTERNALVAR_FUNCTION
;
2222 var
->u
.fn
.function
= f
;
2223 var
->u
.fn
.canonical
= 1;
2224 /* Variables installed here are always the canonical version. */
2228 clear_internalvar (struct internalvar
*var
)
2230 /* Clean up old contents. */
2233 case INTERNALVAR_VALUE
:
2234 value_free (var
->u
.value
);
2237 case INTERNALVAR_STRING
:
2238 xfree (var
->u
.string
);
2241 case INTERNALVAR_MAKE_VALUE
:
2242 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2243 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2250 /* Reset to void kind. */
2251 var
->kind
= INTERNALVAR_VOID
;
2255 internalvar_name (struct internalvar
*var
)
2260 static struct internal_function
*
2261 create_internal_function (const char *name
,
2262 internal_function_fn handler
, void *cookie
)
2264 struct internal_function
*ifn
= XNEW (struct internal_function
);
2266 ifn
->name
= xstrdup (name
);
2267 ifn
->handler
= handler
;
2268 ifn
->cookie
= cookie
;
2273 value_internal_function_name (struct value
*val
)
2275 struct internal_function
*ifn
;
2278 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2279 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2280 gdb_assert (result
);
2286 call_internal_function (struct gdbarch
*gdbarch
,
2287 const struct language_defn
*language
,
2288 struct value
*func
, int argc
, struct value
**argv
)
2290 struct internal_function
*ifn
;
2293 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2294 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2295 gdb_assert (result
);
2297 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2300 /* The 'function' command. This does nothing -- it is just a
2301 placeholder to let "help function NAME" work. This is also used as
2302 the implementation of the sub-command that is created when
2303 registering an internal function. */
2305 function_command (char *command
, int from_tty
)
2310 /* Clean up if an internal function's command is destroyed. */
2312 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2314 xfree ((char *) self
->name
);
2318 /* Add a new internal function. NAME is the name of the function; DOC
2319 is a documentation string describing the function. HANDLER is
2320 called when the function is invoked. COOKIE is an arbitrary
2321 pointer which is passed to HANDLER and is intended for "user
2324 add_internal_function (const char *name
, const char *doc
,
2325 internal_function_fn handler
, void *cookie
)
2327 struct cmd_list_element
*cmd
;
2328 struct internal_function
*ifn
;
2329 struct internalvar
*var
= lookup_internalvar (name
);
2331 ifn
= create_internal_function (name
, handler
, cookie
);
2332 set_internalvar_function (var
, ifn
);
2334 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2336 cmd
->destroyer
= function_destroyer
;
2339 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2340 prevent cycles / duplicates. */
2343 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2344 htab_t copied_types
)
2346 if (TYPE_OBJFILE (value
->type
) == objfile
)
2347 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2349 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2350 value
->enclosing_type
= copy_type_recursive (objfile
,
2351 value
->enclosing_type
,
2355 /* Likewise for internal variable VAR. */
2358 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2359 htab_t copied_types
)
2363 case INTERNALVAR_INTEGER
:
2364 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2366 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2369 case INTERNALVAR_VALUE
:
2370 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2375 /* Update the internal variables and value history when OBJFILE is
2376 discarded; we must copy the types out of the objfile. New global types
2377 will be created for every convenience variable which currently points to
2378 this objfile's types, and the convenience variables will be adjusted to
2379 use the new global types. */
2382 preserve_values (struct objfile
*objfile
)
2384 htab_t copied_types
;
2385 struct value_history_chunk
*cur
;
2386 struct internalvar
*var
;
2389 /* Create the hash table. We allocate on the objfile's obstack, since
2390 it is soon to be deleted. */
2391 copied_types
= create_copied_types_hash (objfile
);
2393 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2394 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2396 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2398 for (var
= internalvars
; var
; var
= var
->next
)
2399 preserve_one_internalvar (var
, objfile
, copied_types
);
2401 preserve_ext_lang_values (objfile
, copied_types
);
2403 htab_delete (copied_types
);
2407 show_convenience (char *ignore
, int from_tty
)
2409 struct gdbarch
*gdbarch
= get_current_arch ();
2410 struct internalvar
*var
;
2412 struct value_print_options opts
;
2414 get_user_print_options (&opts
);
2415 for (var
= internalvars
; var
; var
= var
->next
)
2417 volatile struct gdb_exception ex
;
2423 printf_filtered (("$%s = "), var
->name
);
2425 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2429 val
= value_of_internalvar (gdbarch
, var
);
2430 value_print (val
, gdb_stdout
, &opts
);
2433 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2434 printf_filtered (("\n"));
2438 /* This text does not mention convenience functions on purpose.
2439 The user can't create them except via Python, and if Python support
2440 is installed this message will never be printed ($_streq will
2442 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2443 "Convenience variables have "
2444 "names starting with \"$\";\n"
2445 "use \"set\" as in \"set "
2446 "$foo = 5\" to define them.\n"));
2450 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2453 value_of_xmethod (struct xmethod_worker
*worker
)
2455 if (worker
->value
== NULL
)
2459 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2460 v
->lval
= lval_xcallable
;
2461 v
->location
.xm_worker
= worker
;
2466 return worker
->value
;
2469 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2472 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2474 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2475 && method
->lval
== lval_xcallable
&& argc
> 0);
2477 return invoke_xmethod (method
->location
.xm_worker
,
2478 argv
[0], argv
+ 1, argc
- 1);
2481 /* Extract a value as a C number (either long or double).
2482 Knows how to convert fixed values to double, or
2483 floating values to long.
2484 Does not deallocate the value. */
2487 value_as_long (struct value
*val
)
2489 /* This coerces arrays and functions, which is necessary (e.g.
2490 in disassemble_command). It also dereferences references, which
2491 I suspect is the most logical thing to do. */
2492 val
= coerce_array (val
);
2493 return unpack_long (value_type (val
), value_contents (val
));
2497 value_as_double (struct value
*val
)
2502 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2504 error (_("Invalid floating value found in program."));
2508 /* Extract a value as a C pointer. Does not deallocate the value.
2509 Note that val's type may not actually be a pointer; value_as_long
2510 handles all the cases. */
2512 value_as_address (struct value
*val
)
2514 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2516 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2517 whether we want this to be true eventually. */
2519 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2520 non-address (e.g. argument to "signal", "info break", etc.), or
2521 for pointers to char, in which the low bits *are* significant. */
2522 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2525 /* There are several targets (IA-64, PowerPC, and others) which
2526 don't represent pointers to functions as simply the address of
2527 the function's entry point. For example, on the IA-64, a
2528 function pointer points to a two-word descriptor, generated by
2529 the linker, which contains the function's entry point, and the
2530 value the IA-64 "global pointer" register should have --- to
2531 support position-independent code. The linker generates
2532 descriptors only for those functions whose addresses are taken.
2534 On such targets, it's difficult for GDB to convert an arbitrary
2535 function address into a function pointer; it has to either find
2536 an existing descriptor for that function, or call malloc and
2537 build its own. On some targets, it is impossible for GDB to
2538 build a descriptor at all: the descriptor must contain a jump
2539 instruction; data memory cannot be executed; and code memory
2542 Upon entry to this function, if VAL is a value of type `function'
2543 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2544 value_address (val) is the address of the function. This is what
2545 you'll get if you evaluate an expression like `main'. The call
2546 to COERCE_ARRAY below actually does all the usual unary
2547 conversions, which includes converting values of type `function'
2548 to `pointer to function'. This is the challenging conversion
2549 discussed above. Then, `unpack_long' will convert that pointer
2550 back into an address.
2552 So, suppose the user types `disassemble foo' on an architecture
2553 with a strange function pointer representation, on which GDB
2554 cannot build its own descriptors, and suppose further that `foo'
2555 has no linker-built descriptor. The address->pointer conversion
2556 will signal an error and prevent the command from running, even
2557 though the next step would have been to convert the pointer
2558 directly back into the same address.
2560 The following shortcut avoids this whole mess. If VAL is a
2561 function, just return its address directly. */
2562 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2563 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2564 return value_address (val
);
2566 val
= coerce_array (val
);
2568 /* Some architectures (e.g. Harvard), map instruction and data
2569 addresses onto a single large unified address space. For
2570 instance: An architecture may consider a large integer in the
2571 range 0x10000000 .. 0x1000ffff to already represent a data
2572 addresses (hence not need a pointer to address conversion) while
2573 a small integer would still need to be converted integer to
2574 pointer to address. Just assume such architectures handle all
2575 integer conversions in a single function. */
2579 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2580 must admonish GDB hackers to make sure its behavior matches the
2581 compiler's, whenever possible.
2583 In general, I think GDB should evaluate expressions the same way
2584 the compiler does. When the user copies an expression out of
2585 their source code and hands it to a `print' command, they should
2586 get the same value the compiler would have computed. Any
2587 deviation from this rule can cause major confusion and annoyance,
2588 and needs to be justified carefully. In other words, GDB doesn't
2589 really have the freedom to do these conversions in clever and
2592 AndrewC pointed out that users aren't complaining about how GDB
2593 casts integers to pointers; they are complaining that they can't
2594 take an address from a disassembly listing and give it to `x/i'.
2595 This is certainly important.
2597 Adding an architecture method like integer_to_address() certainly
2598 makes it possible for GDB to "get it right" in all circumstances
2599 --- the target has complete control over how things get done, so
2600 people can Do The Right Thing for their target without breaking
2601 anyone else. The standard doesn't specify how integers get
2602 converted to pointers; usually, the ABI doesn't either, but
2603 ABI-specific code is a more reasonable place to handle it. */
2605 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2606 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2607 && gdbarch_integer_to_address_p (gdbarch
))
2608 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2609 value_contents (val
));
2611 return unpack_long (value_type (val
), value_contents (val
));
2615 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2616 as a long, or as a double, assuming the raw data is described
2617 by type TYPE. Knows how to convert different sizes of values
2618 and can convert between fixed and floating point. We don't assume
2619 any alignment for the raw data. Return value is in host byte order.
2621 If you want functions and arrays to be coerced to pointers, and
2622 references to be dereferenced, call value_as_long() instead.
2624 C++: It is assumed that the front-end has taken care of
2625 all matters concerning pointers to members. A pointer
2626 to member which reaches here is considered to be equivalent
2627 to an INT (or some size). After all, it is only an offset. */
2630 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2632 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2633 enum type_code code
= TYPE_CODE (type
);
2634 int len
= TYPE_LENGTH (type
);
2635 int nosign
= TYPE_UNSIGNED (type
);
2639 case TYPE_CODE_TYPEDEF
:
2640 return unpack_long (check_typedef (type
), valaddr
);
2641 case TYPE_CODE_ENUM
:
2642 case TYPE_CODE_FLAGS
:
2643 case TYPE_CODE_BOOL
:
2645 case TYPE_CODE_CHAR
:
2646 case TYPE_CODE_RANGE
:
2647 case TYPE_CODE_MEMBERPTR
:
2649 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2651 return extract_signed_integer (valaddr
, len
, byte_order
);
2654 return extract_typed_floating (valaddr
, type
);
2656 case TYPE_CODE_DECFLOAT
:
2657 /* libdecnumber has a function to convert from decimal to integer, but
2658 it doesn't work when the decimal number has a fractional part. */
2659 return decimal_to_doublest (valaddr
, len
, byte_order
);
2663 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2664 whether we want this to be true eventually. */
2665 return extract_typed_address (valaddr
, type
);
2668 error (_("Value can't be converted to integer."));
2670 return 0; /* Placate lint. */
2673 /* Return a double value from the specified type and address.
2674 INVP points to an int which is set to 0 for valid value,
2675 1 for invalid value (bad float format). In either case,
2676 the returned double is OK to use. Argument is in target
2677 format, result is in host format. */
2680 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2682 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2683 enum type_code code
;
2687 *invp
= 0; /* Assume valid. */
2688 CHECK_TYPEDEF (type
);
2689 code
= TYPE_CODE (type
);
2690 len
= TYPE_LENGTH (type
);
2691 nosign
= TYPE_UNSIGNED (type
);
2692 if (code
== TYPE_CODE_FLT
)
2694 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2695 floating-point value was valid (using the macro
2696 INVALID_FLOAT). That test/macro have been removed.
2698 It turns out that only the VAX defined this macro and then
2699 only in a non-portable way. Fixing the portability problem
2700 wouldn't help since the VAX floating-point code is also badly
2701 bit-rotten. The target needs to add definitions for the
2702 methods gdbarch_float_format and gdbarch_double_format - these
2703 exactly describe the target floating-point format. The
2704 problem here is that the corresponding floatformat_vax_f and
2705 floatformat_vax_d values these methods should be set to are
2706 also not defined either. Oops!
2708 Hopefully someone will add both the missing floatformat
2709 definitions and the new cases for floatformat_is_valid (). */
2711 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2717 return extract_typed_floating (valaddr
, type
);
2719 else if (code
== TYPE_CODE_DECFLOAT
)
2720 return decimal_to_doublest (valaddr
, len
, byte_order
);
2723 /* Unsigned -- be sure we compensate for signed LONGEST. */
2724 return (ULONGEST
) unpack_long (type
, valaddr
);
2728 /* Signed -- we are OK with unpack_long. */
2729 return unpack_long (type
, valaddr
);
2733 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2734 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2735 We don't assume any alignment for the raw data. Return value is in
2738 If you want functions and arrays to be coerced to pointers, and
2739 references to be dereferenced, call value_as_address() instead.
2741 C++: It is assumed that the front-end has taken care of
2742 all matters concerning pointers to members. A pointer
2743 to member which reaches here is considered to be equivalent
2744 to an INT (or some size). After all, it is only an offset. */
2747 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2749 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2750 whether we want this to be true eventually. */
2751 return unpack_long (type
, valaddr
);
2755 /* Get the value of the FIELDNO'th field (which must be static) of
2759 value_static_field (struct type
*type
, int fieldno
)
2761 struct value
*retval
;
2763 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2765 case FIELD_LOC_KIND_PHYSADDR
:
2766 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2767 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2769 case FIELD_LOC_KIND_PHYSNAME
:
2771 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2772 /* TYPE_FIELD_NAME (type, fieldno); */
2773 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2777 /* With some compilers, e.g. HP aCC, static data members are
2778 reported as non-debuggable symbols. */
2779 struct bound_minimal_symbol msym
2780 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2783 return allocate_optimized_out_value (type
);
2786 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2787 BMSYMBOL_VALUE_ADDRESS (msym
));
2791 retval
= value_of_variable (sym
, NULL
);
2795 gdb_assert_not_reached ("unexpected field location kind");
2801 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2802 You have to be careful here, since the size of the data area for the value
2803 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2804 than the old enclosing type, you have to allocate more space for the
2808 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2810 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2812 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2814 val
->enclosing_type
= new_encl_type
;
2817 /* Given a value ARG1 (offset by OFFSET bytes)
2818 of a struct or union type ARG_TYPE,
2819 extract and return the value of one of its (non-static) fields.
2820 FIELDNO says which field. */
2823 value_primitive_field (struct value
*arg1
, int offset
,
2824 int fieldno
, struct type
*arg_type
)
2829 CHECK_TYPEDEF (arg_type
);
2830 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2832 /* Call check_typedef on our type to make sure that, if TYPE
2833 is a TYPE_CODE_TYPEDEF, its length is set to the length
2834 of the target type instead of zero. However, we do not
2835 replace the typedef type by the target type, because we want
2836 to keep the typedef in order to be able to print the type
2837 description correctly. */
2838 check_typedef (type
);
2840 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2842 /* Handle packed fields.
2844 Create a new value for the bitfield, with bitpos and bitsize
2845 set. If possible, arrange offset and bitpos so that we can
2846 do a single aligned read of the size of the containing type.
2847 Otherwise, adjust offset to the byte containing the first
2848 bit. Assume that the address, offset, and embedded offset
2849 are sufficiently aligned. */
2851 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2852 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2854 if (arg1
->optimized_out
)
2855 v
= allocate_optimized_out_value (type
);
2858 v
= allocate_value_lazy (type
);
2859 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2860 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2861 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2862 v
->bitpos
= bitpos
% container_bitsize
;
2864 v
->bitpos
= bitpos
% 8;
2865 v
->offset
= (value_embedded_offset (arg1
)
2867 + (bitpos
- v
->bitpos
) / 8);
2868 set_value_parent (v
, arg1
);
2869 if (!value_lazy (arg1
))
2870 value_fetch_lazy (v
);
2873 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2875 /* This field is actually a base subobject, so preserve the
2876 entire object's contents for later references to virtual
2880 /* Lazy register values with offsets are not supported. */
2881 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2882 value_fetch_lazy (arg1
);
2884 /* The optimized_out flag is only set correctly once a lazy value is
2885 loaded, having just loaded some lazy values we should check the
2886 optimized out case now. */
2887 if (arg1
->optimized_out
)
2888 v
= allocate_optimized_out_value (type
);
2891 /* We special case virtual inheritance here because this
2892 requires access to the contents, which we would rather avoid
2893 for references to ordinary fields of unavailable values. */
2894 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2895 boffset
= baseclass_offset (arg_type
, fieldno
,
2896 value_contents (arg1
),
2897 value_embedded_offset (arg1
),
2898 value_address (arg1
),
2901 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2903 if (value_lazy (arg1
))
2904 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2907 v
= allocate_value (value_enclosing_type (arg1
));
2908 value_contents_copy_raw (v
, 0, arg1
, 0,
2909 TYPE_LENGTH (value_enclosing_type (arg1
)));
2912 v
->offset
= value_offset (arg1
);
2913 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2918 /* Plain old data member */
2919 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2921 /* Lazy register values with offsets are not supported. */
2922 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2923 value_fetch_lazy (arg1
);
2925 /* The optimized_out flag is only set correctly once a lazy value is
2926 loaded, having just loaded some lazy values we should check for
2927 the optimized out case now. */
2928 if (arg1
->optimized_out
)
2929 v
= allocate_optimized_out_value (type
);
2930 else if (value_lazy (arg1
))
2931 v
= allocate_value_lazy (type
);
2934 v
= allocate_value (type
);
2935 value_contents_copy_raw (v
, value_embedded_offset (v
),
2936 arg1
, value_embedded_offset (arg1
) + offset
,
2937 TYPE_LENGTH (type
));
2939 v
->offset
= (value_offset (arg1
) + offset
2940 + value_embedded_offset (arg1
));
2942 set_value_component_location (v
, arg1
);
2943 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2944 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2948 /* Given a value ARG1 of a struct or union type,
2949 extract and return the value of one of its (non-static) fields.
2950 FIELDNO says which field. */
2953 value_field (struct value
*arg1
, int fieldno
)
2955 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2958 /* Return a non-virtual function as a value.
2959 F is the list of member functions which contains the desired method.
2960 J is an index into F which provides the desired method.
2962 We only use the symbol for its address, so be happy with either a
2963 full symbol or a minimal symbol. */
2966 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2967 int j
, struct type
*type
,
2971 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2972 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2974 struct bound_minimal_symbol msym
;
2976 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2979 memset (&msym
, 0, sizeof (msym
));
2983 gdb_assert (sym
== NULL
);
2984 msym
= lookup_bound_minimal_symbol (physname
);
2985 if (msym
.minsym
== NULL
)
2989 v
= allocate_value (ftype
);
2992 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2996 /* The minimal symbol might point to a function descriptor;
2997 resolve it to the actual code address instead. */
2998 struct objfile
*objfile
= msym
.objfile
;
2999 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3001 set_value_address (v
,
3002 gdbarch_convert_from_func_ptr_addr
3003 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3008 if (type
!= value_type (*arg1p
))
3009 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3010 value_addr (*arg1p
)));
3012 /* Move the `this' pointer according to the offset.
3013 VALUE_OFFSET (*arg1p) += offset; */
3021 /* Helper function for both unpack_value_bits_as_long and
3022 unpack_bits_as_long. See those functions for more details on the
3023 interface; the only difference is that this function accepts either
3024 a NULL or a non-NULL ORIGINAL_VALUE. */
3027 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
3028 int embedded_offset
, int bitpos
, int bitsize
,
3029 const struct value
*original_value
,
3032 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3039 /* Read the minimum number of bytes required; there may not be
3040 enough bytes to read an entire ULONGEST. */
3041 CHECK_TYPEDEF (field_type
);
3043 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3045 bytes_read
= TYPE_LENGTH (field_type
);
3047 read_offset
= bitpos
/ 8;
3049 if (original_value
!= NULL
3050 && !value_bits_available (original_value
, embedded_offset
+ bitpos
,
3054 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
3055 bytes_read
, byte_order
);
3057 /* Extract bits. See comment above. */
3059 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3060 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3062 lsbcount
= (bitpos
% 8);
3065 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3066 If the field is signed, and is negative, then sign extend. */
3068 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
3070 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3072 if (!TYPE_UNSIGNED (field_type
))
3074 if (val
& (valmask
^ (valmask
>> 1)))
3085 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3086 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
3087 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
3088 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
3091 Returns false if the value contents are unavailable, otherwise
3092 returns true, indicating a valid value has been stored in *RESULT.
3094 Extracting bits depends on endianness of the machine. Compute the
3095 number of least significant bits to discard. For big endian machines,
3096 we compute the total number of bits in the anonymous object, subtract
3097 off the bit count from the MSB of the object to the MSB of the
3098 bitfield, then the size of the bitfield, which leaves the LSB discard
3099 count. For little endian machines, the discard count is simply the
3100 number of bits from the LSB of the anonymous object to the LSB of the
3103 If the field is signed, we also do sign extension. */
3106 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3107 int embedded_offset
, int bitpos
, int bitsize
,
3108 const struct value
*original_value
,
3111 gdb_assert (original_value
!= NULL
);
3113 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
3114 bitpos
, bitsize
, original_value
, result
);
3118 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3119 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3120 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
3124 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
3125 int embedded_offset
, int fieldno
,
3126 const struct value
*val
, LONGEST
*result
)
3128 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3129 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3130 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3132 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
3133 bitpos
, bitsize
, val
,
3137 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3138 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3139 ORIGINAL_VALUE, which must not be NULL. See
3140 unpack_value_bits_as_long for more details. */
3143 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3144 int embedded_offset
, int fieldno
,
3145 const struct value
*val
, LONGEST
*result
)
3147 gdb_assert (val
!= NULL
);
3149 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
3150 fieldno
, val
, result
);
3153 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3154 object at VALADDR. See unpack_value_bits_as_long for more details.
3155 This function differs from unpack_value_field_as_long in that it
3156 operates without a struct value object. */
3159 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3163 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
3167 /* Return a new value with type TYPE, which is FIELDNO field of the
3168 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3169 of VAL. If the VAL's contents required to extract the bitfield
3170 from are unavailable, the new value is correspondingly marked as
3174 value_field_bitfield (struct type
*type
, int fieldno
,
3175 const gdb_byte
*valaddr
,
3176 int embedded_offset
, const struct value
*val
)
3180 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
3183 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3184 struct value
*retval
= allocate_value (field_type
);
3185 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
3190 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
3194 /* Modify the value of a bitfield. ADDR points to a block of memory in
3195 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3196 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3197 indicate which bits (in target bit order) comprise the bitfield.
3198 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3199 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3202 modify_field (struct type
*type
, gdb_byte
*addr
,
3203 LONGEST fieldval
, int bitpos
, int bitsize
)
3205 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3207 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3210 /* Normalize BITPOS. */
3214 /* If a negative fieldval fits in the field in question, chop
3215 off the sign extension bits. */
3216 if ((~fieldval
& ~(mask
>> 1)) == 0)
3219 /* Warn if value is too big to fit in the field in question. */
3220 if (0 != (fieldval
& ~mask
))
3222 /* FIXME: would like to include fieldval in the message, but
3223 we don't have a sprintf_longest. */
3224 warning (_("Value does not fit in %d bits."), bitsize
);
3226 /* Truncate it, otherwise adjoining fields may be corrupted. */
3230 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3231 false valgrind reports. */
3233 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3234 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3236 /* Shifting for bit field depends on endianness of the target machine. */
3237 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3238 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3240 oword
&= ~(mask
<< bitpos
);
3241 oword
|= fieldval
<< bitpos
;
3243 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3246 /* Pack NUM into BUF using a target format of TYPE. */
3249 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3251 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3254 type
= check_typedef (type
);
3255 len
= TYPE_LENGTH (type
);
3257 switch (TYPE_CODE (type
))
3260 case TYPE_CODE_CHAR
:
3261 case TYPE_CODE_ENUM
:
3262 case TYPE_CODE_FLAGS
:
3263 case TYPE_CODE_BOOL
:
3264 case TYPE_CODE_RANGE
:
3265 case TYPE_CODE_MEMBERPTR
:
3266 store_signed_integer (buf
, len
, byte_order
, num
);
3271 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3275 error (_("Unexpected type (%d) encountered for integer constant."),
3281 /* Pack NUM into BUF using a target format of TYPE. */
3284 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3287 enum bfd_endian byte_order
;
3289 type
= check_typedef (type
);
3290 len
= TYPE_LENGTH (type
);
3291 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3293 switch (TYPE_CODE (type
))
3296 case TYPE_CODE_CHAR
:
3297 case TYPE_CODE_ENUM
:
3298 case TYPE_CODE_FLAGS
:
3299 case TYPE_CODE_BOOL
:
3300 case TYPE_CODE_RANGE
:
3301 case TYPE_CODE_MEMBERPTR
:
3302 store_unsigned_integer (buf
, len
, byte_order
, num
);
3307 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3311 error (_("Unexpected type (%d) encountered "
3312 "for unsigned integer constant."),
3318 /* Convert C numbers into newly allocated values. */
3321 value_from_longest (struct type
*type
, LONGEST num
)
3323 struct value
*val
= allocate_value (type
);
3325 pack_long (value_contents_raw (val
), type
, num
);
3330 /* Convert C unsigned numbers into newly allocated values. */
3333 value_from_ulongest (struct type
*type
, ULONGEST num
)
3335 struct value
*val
= allocate_value (type
);
3337 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3343 /* Create a value representing a pointer of type TYPE to the address
3344 ADDR. The type of the created value may differ from the passed
3345 type TYPE. Make sure to retrieve the returned values's new type
3346 after this call e.g. in case of an variable length array. */
3349 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3351 struct type
*resolved_type
= resolve_dynamic_type (type
, addr
);
3352 struct value
*val
= allocate_value (resolved_type
);
3354 store_typed_address (value_contents_raw (val
),
3355 check_typedef (resolved_type
), addr
);
3360 /* Create a value of type TYPE whose contents come from VALADDR, if it
3361 is non-null, and whose memory address (in the inferior) is
3362 ADDRESS. The type of the created value may differ from the passed
3363 type TYPE. Make sure to retrieve values new type after this call.
3364 Note that TYPE is not passed through resolve_dynamic_type; this is
3365 a special API intended for use only by Ada. */
3368 value_from_contents_and_address_unresolved (struct type
*type
,
3369 const gdb_byte
*valaddr
,
3374 if (valaddr
== NULL
)
3375 v
= allocate_value_lazy (type
);
3377 v
= value_from_contents (type
, valaddr
);
3378 set_value_address (v
, address
);
3379 VALUE_LVAL (v
) = lval_memory
;
3383 /* Create a value of type TYPE whose contents come from VALADDR, if it
3384 is non-null, and whose memory address (in the inferior) is
3385 ADDRESS. The type of the created value may differ from the passed
3386 type TYPE. Make sure to retrieve values new type after this call. */
3389 value_from_contents_and_address (struct type
*type
,
3390 const gdb_byte
*valaddr
,
3393 struct type
*resolved_type
= resolve_dynamic_type (type
, address
);
3396 if (valaddr
== NULL
)
3397 v
= allocate_value_lazy (resolved_type
);
3399 v
= value_from_contents (resolved_type
, valaddr
);
3400 set_value_address (v
, address
);
3401 VALUE_LVAL (v
) = lval_memory
;
3405 /* Create a value of type TYPE holding the contents CONTENTS.
3406 The new value is `not_lval'. */
3409 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3411 struct value
*result
;
3413 result
= allocate_value (type
);
3414 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3419 value_from_double (struct type
*type
, DOUBLEST num
)
3421 struct value
*val
= allocate_value (type
);
3422 struct type
*base_type
= check_typedef (type
);
3423 enum type_code code
= TYPE_CODE (base_type
);
3425 if (code
== TYPE_CODE_FLT
)
3427 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3430 error (_("Unexpected type encountered for floating constant."));
3436 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3438 struct value
*val
= allocate_value (type
);
3440 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3444 /* Extract a value from the history file. Input will be of the form
3445 $digits or $$digits. See block comment above 'write_dollar_variable'
3449 value_from_history_ref (char *h
, char **endp
)
3461 /* Find length of numeral string. */
3462 for (; isdigit (h
[len
]); len
++)
3465 /* Make sure numeral string is not part of an identifier. */
3466 if (h
[len
] == '_' || isalpha (h
[len
]))
3469 /* Now collect the index value. */
3474 /* For some bizarre reason, "$$" is equivalent to "$$1",
3475 rather than to "$$0" as it ought to be! */
3480 index
= -strtol (&h
[2], endp
, 10);
3486 /* "$" is equivalent to "$0". */
3491 index
= strtol (&h
[1], endp
, 10);
3494 return access_value_history (index
);
3498 coerce_ref_if_computed (const struct value
*arg
)
3500 const struct lval_funcs
*funcs
;
3502 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3505 if (value_lval_const (arg
) != lval_computed
)
3508 funcs
= value_computed_funcs (arg
);
3509 if (funcs
->coerce_ref
== NULL
)
3512 return funcs
->coerce_ref (arg
);
3515 /* Look at value.h for description. */
3518 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3519 struct type
*original_type
,
3520 struct value
*original_value
)
3522 /* Re-adjust type. */
3523 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3525 /* Add embedding info. */
3526 set_value_enclosing_type (value
, enc_type
);
3527 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3529 /* We may be pointing to an object of some derived type. */
3530 return value_full_object (value
, NULL
, 0, 0, 0);
3534 coerce_ref (struct value
*arg
)
3536 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3537 struct value
*retval
;
3538 struct type
*enc_type
;
3540 retval
= coerce_ref_if_computed (arg
);
3544 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3547 enc_type
= check_typedef (value_enclosing_type (arg
));
3548 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3550 retval
= value_at_lazy (enc_type
,
3551 unpack_pointer (value_type (arg
),
3552 value_contents (arg
)));
3553 enc_type
= value_type (retval
);
3554 return readjust_indirect_value_type (retval
, enc_type
,
3555 value_type_arg_tmp
, arg
);
3559 coerce_array (struct value
*arg
)
3563 arg
= coerce_ref (arg
);
3564 type
= check_typedef (value_type (arg
));
3566 switch (TYPE_CODE (type
))
3568 case TYPE_CODE_ARRAY
:
3569 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3570 arg
= value_coerce_array (arg
);
3572 case TYPE_CODE_FUNC
:
3573 arg
= value_coerce_function (arg
);
3580 /* Return the return value convention that will be used for the
3583 enum return_value_convention
3584 struct_return_convention (struct gdbarch
*gdbarch
,
3585 struct value
*function
, struct type
*value_type
)
3587 enum type_code code
= TYPE_CODE (value_type
);
3589 if (code
== TYPE_CODE_ERROR
)
3590 error (_("Function return type unknown."));
3592 /* Probe the architecture for the return-value convention. */
3593 return gdbarch_return_value (gdbarch
, function
, value_type
,
3597 /* Return true if the function returning the specified type is using
3598 the convention of returning structures in memory (passing in the
3599 address as a hidden first parameter). */
3602 using_struct_return (struct gdbarch
*gdbarch
,
3603 struct value
*function
, struct type
*value_type
)
3605 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3606 /* A void return value is never in memory. See also corresponding
3607 code in "print_return_value". */
3610 return (struct_return_convention (gdbarch
, function
, value_type
)
3611 != RETURN_VALUE_REGISTER_CONVENTION
);
3614 /* Set the initialized field in a value struct. */
3617 set_value_initialized (struct value
*val
, int status
)
3619 val
->initialized
= status
;
3622 /* Return the initialized field in a value struct. */
3625 value_initialized (struct value
*val
)
3627 return val
->initialized
;
3630 /* Called only from the value_contents and value_contents_all()
3631 macros, if the current data for a variable needs to be loaded into
3632 value_contents(VAL). Fetches the data from the user's process, and
3633 clears the lazy flag to indicate that the data in the buffer is
3636 If the value is zero-length, we avoid calling read_memory, which
3637 would abort. We mark the value as fetched anyway -- all 0 bytes of
3640 This function returns a value because it is used in the
3641 value_contents macro as part of an expression, where a void would
3642 not work. The value is ignored. */
3645 value_fetch_lazy (struct value
*val
)
3647 gdb_assert (value_lazy (val
));
3648 allocate_value_contents (val
);
3649 if (value_bitsize (val
))
3651 /* To read a lazy bitfield, read the entire enclosing value. This
3652 prevents reading the same block of (possibly volatile) memory once
3653 per bitfield. It would be even better to read only the containing
3654 word, but we have no way to record that just specific bits of a
3655 value have been fetched. */
3656 struct type
*type
= check_typedef (value_type (val
));
3657 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3658 struct value
*parent
= value_parent (val
);
3659 LONGEST offset
= value_offset (val
);
3662 if (value_lazy (parent
))
3663 value_fetch_lazy (parent
);
3665 if (!value_bits_valid (parent
,
3666 TARGET_CHAR_BIT
* offset
+ value_bitpos (val
),
3667 value_bitsize (val
)))
3668 set_value_optimized_out (val
, 1);
3669 else if (!unpack_value_bits_as_long (value_type (val
),
3670 value_contents_for_printing (parent
),
3673 value_bitsize (val
), parent
, &num
))
3674 mark_value_bytes_unavailable (val
,
3675 value_embedded_offset (val
),
3676 TYPE_LENGTH (type
));
3678 store_signed_integer (value_contents_raw (val
), TYPE_LENGTH (type
),
3681 else if (VALUE_LVAL (val
) == lval_memory
)
3683 CORE_ADDR addr
= value_address (val
);
3684 struct type
*type
= check_typedef (value_enclosing_type (val
));
3686 if (TYPE_LENGTH (type
))
3687 read_value_memory (val
, 0, value_stack (val
),
3688 addr
, value_contents_all_raw (val
),
3689 TYPE_LENGTH (type
));
3691 else if (VALUE_LVAL (val
) == lval_register
)
3693 struct frame_info
*frame
;
3695 struct type
*type
= check_typedef (value_type (val
));
3696 struct value
*new_val
= val
, *mark
= value_mark ();
3698 /* Offsets are not supported here; lazy register values must
3699 refer to the entire register. */
3700 gdb_assert (value_offset (val
) == 0);
3702 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3704 struct frame_id frame_id
= VALUE_FRAME_ID (new_val
);
3706 frame
= frame_find_by_id (frame_id
);
3707 regnum
= VALUE_REGNUM (new_val
);
3709 gdb_assert (frame
!= NULL
);
3711 /* Convertible register routines are used for multi-register
3712 values and for interpretation in different types
3713 (e.g. float or int from a double register). Lazy
3714 register values should have the register's natural type,
3715 so they do not apply. */
3716 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3719 new_val
= get_frame_register_value (frame
, regnum
);
3721 /* If we get another lazy lval_register value, it means the
3722 register is found by reading it from the next frame.
3723 get_frame_register_value should never return a value with
3724 the frame id pointing to FRAME. If it does, it means we
3725 either have two consecutive frames with the same frame id
3726 in the frame chain, or some code is trying to unwind
3727 behind get_prev_frame's back (e.g., a frame unwind
3728 sniffer trying to unwind), bypassing its validations. In
3729 any case, it should always be an internal error to end up
3730 in this situation. */
3731 if (VALUE_LVAL (new_val
) == lval_register
3732 && value_lazy (new_val
)
3733 && frame_id_eq (VALUE_FRAME_ID (new_val
), frame_id
))
3734 internal_error (__FILE__
, __LINE__
,
3735 _("infinite loop while fetching a register"));
3738 /* If it's still lazy (for instance, a saved register on the
3739 stack), fetch it. */
3740 if (value_lazy (new_val
))
3741 value_fetch_lazy (new_val
);
3743 /* If the register was not saved, mark it optimized out. */
3744 if (value_optimized_out (new_val
))
3745 set_value_optimized_out (val
, 1);
3748 set_value_lazy (val
, 0);
3749 value_contents_copy (val
, value_embedded_offset (val
),
3750 new_val
, value_embedded_offset (new_val
),
3751 TYPE_LENGTH (type
));
3756 struct gdbarch
*gdbarch
;
3757 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3758 regnum
= VALUE_REGNUM (val
);
3759 gdbarch
= get_frame_arch (frame
);
3761 fprintf_unfiltered (gdb_stdlog
,
3762 "{ value_fetch_lazy "
3763 "(frame=%d,regnum=%d(%s),...) ",
3764 frame_relative_level (frame
), regnum
,
3765 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3767 fprintf_unfiltered (gdb_stdlog
, "->");
3768 if (value_optimized_out (new_val
))
3770 fprintf_unfiltered (gdb_stdlog
, " ");
3771 val_print_optimized_out (new_val
, gdb_stdlog
);
3776 const gdb_byte
*buf
= value_contents (new_val
);
3778 if (VALUE_LVAL (new_val
) == lval_register
)
3779 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3780 VALUE_REGNUM (new_val
));
3781 else if (VALUE_LVAL (new_val
) == lval_memory
)
3782 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3784 value_address (new_val
)));
3786 fprintf_unfiltered (gdb_stdlog
, " computed");
3788 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3789 fprintf_unfiltered (gdb_stdlog
, "[");
3790 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3791 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3792 fprintf_unfiltered (gdb_stdlog
, "]");
3795 fprintf_unfiltered (gdb_stdlog
, " }\n");
3798 /* Dispose of the intermediate values. This prevents
3799 watchpoints from trying to watch the saved frame pointer. */
3800 value_free_to_mark (mark
);
3802 else if (VALUE_LVAL (val
) == lval_computed
3803 && value_computed_funcs (val
)->read
!= NULL
)
3804 value_computed_funcs (val
)->read (val
);
3805 /* Don't call value_optimized_out on val, doing so would result in a
3806 recursive call back to value_fetch_lazy, instead check the
3807 optimized_out flag directly. */
3808 else if (val
->optimized_out
)
3809 /* Keep it optimized out. */;
3811 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3813 set_value_lazy (val
, 0);
3817 /* Implementation of the convenience function $_isvoid. */
3819 static struct value
*
3820 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3821 const struct language_defn
*language
,
3822 void *cookie
, int argc
, struct value
**argv
)
3827 error (_("You must provide one argument for $_isvoid."));
3829 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3831 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3835 _initialize_values (void)
3837 add_cmd ("convenience", no_class
, show_convenience
, _("\
3838 Debugger convenience (\"$foo\") variables and functions.\n\
3839 Convenience variables are created when you assign them values;\n\
3840 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3842 A few convenience variables are given values automatically:\n\
3843 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3844 \"$__\" holds the contents of the last address examined with \"x\"."
3847 Convenience functions are defined via the Python API."
3850 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3852 add_cmd ("values", no_set_class
, show_values
, _("\
3853 Elements of value history around item number IDX (or last ten)."),
3856 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3857 Initialize a convenience variable if necessary.\n\
3858 init-if-undefined VARIABLE = EXPRESSION\n\
3859 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3860 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3861 VARIABLE is already initialized."));
3863 add_prefix_cmd ("function", no_class
, function_command
, _("\
3864 Placeholder command for showing help on convenience functions."),
3865 &functionlist
, "function ", 0, &cmdlist
);
3867 add_internal_function ("_isvoid", _("\
3868 Check whether an expression is void.\n\
3869 Usage: $_isvoid (expression)\n\
3870 Return 1 if the expression is void, zero otherwise."),
3871 isvoid_internal_fn
, NULL
);