1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2013 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"
22 #include "gdb_string.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
46 /* Prototypes for exported functions. */
48 void _initialize_values (void);
50 /* Definition of a user function. */
51 struct internal_function
53 /* The name of the function. It is a bit odd to have this in the
54 function itself -- the user might use a differently-named
55 convenience variable to hold the function. */
59 internal_function_fn handler
;
61 /* User data for the handler. */
65 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
69 /* Lowest offset in the range. */
72 /* Length of the range. */
76 typedef struct range range_s
;
80 /* Returns true if the ranges defined by [offset1, offset1+len1) and
81 [offset2, offset2+len2) overlap. */
84 ranges_overlap (int offset1
, int len1
,
85 int offset2
, int len2
)
89 l
= max (offset1
, offset2
);
90 h
= min (offset1
+ len1
, offset2
+ len2
);
94 /* Returns true if the first argument is strictly less than the
95 second, useful for VEC_lower_bound. We keep ranges sorted by
96 offset and coalesce overlapping and contiguous ranges, so this just
97 compares the starting offset. */
100 range_lessthan (const range_s
*r1
, const range_s
*r2
)
102 return r1
->offset
< r2
->offset
;
105 /* Returns true if RANGES contains any range that overlaps [OFFSET,
109 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
114 what
.offset
= offset
;
115 what
.length
= length
;
117 /* We keep ranges sorted by offset and coalesce overlapping and
118 contiguous ranges, so to check if a range list contains a given
119 range, we can do a binary search for the position the given range
120 would be inserted if we only considered the starting OFFSET of
121 ranges. We call that position I. Since we also have LENGTH to
122 care for (this is a range afterall), we need to check if the
123 _previous_ range overlaps the I range. E.g.,
127 |---| |---| |------| ... |--|
132 In the case above, the binary search would return `I=1', meaning,
133 this OFFSET should be inserted at position 1, and the current
134 position 1 should be pushed further (and before 2). But, `0'
137 Then we need to check if the I range overlaps the I range itself.
142 |---| |---| |-------| ... |--|
148 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
152 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
154 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
158 if (i
< VEC_length (range_s
, ranges
))
160 struct range
*r
= VEC_index (range_s
, ranges
, i
);
162 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
169 static struct cmd_list_element
*functionlist
;
171 /* Note that the fields in this structure are arranged to save a bit
176 /* Type of value; either not an lval, or one of the various
177 different possible kinds of lval. */
180 /* Is it modifiable? Only relevant if lval != not_lval. */
181 unsigned int modifiable
: 1;
183 /* If zero, contents of this value are in the contents field. If
184 nonzero, contents are in inferior. If the lval field is lval_memory,
185 the contents are in inferior memory at location.address plus offset.
186 The lval field may also be lval_register.
188 WARNING: This field is used by the code which handles watchpoints
189 (see breakpoint.c) to decide whether a particular value can be
190 watched by hardware watchpoints. If the lazy flag is set for
191 some member of a value chain, it is assumed that this member of
192 the chain doesn't need to be watched as part of watching the
193 value itself. This is how GDB avoids watching the entire struct
194 or array when the user wants to watch a single struct member or
195 array element. If you ever change the way lazy flag is set and
196 reset, be sure to consider this use as well! */
197 unsigned int lazy
: 1;
199 /* If nonzero, this is the value of a variable which does not
200 actually exist in the program. */
201 unsigned int optimized_out
: 1;
203 /* If value is a variable, is it initialized or not. */
204 unsigned int initialized
: 1;
206 /* If value is from the stack. If this is set, read_stack will be
207 used instead of read_memory to enable extra caching. */
208 unsigned int stack
: 1;
210 /* If the value has been released. */
211 unsigned int released
: 1;
213 /* Location of value (if lval). */
216 /* If lval == lval_memory, this is the address in the inferior.
217 If lval == lval_register, this is the byte offset into the
218 registers structure. */
221 /* Pointer to internal variable. */
222 struct internalvar
*internalvar
;
224 /* If lval == lval_computed, this is a set of function pointers
225 to use to access and describe the value, and a closure pointer
229 /* Functions to call. */
230 const struct lval_funcs
*funcs
;
232 /* Closure for those functions to use. */
237 /* Describes offset of a value within lval of a structure in bytes.
238 If lval == lval_memory, this is an offset to the address. If
239 lval == lval_register, this is a further offset from
240 location.address within the registers structure. Note also the
241 member embedded_offset below. */
244 /* Only used for bitfields; number of bits contained in them. */
247 /* Only used for bitfields; position of start of field. For
248 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
249 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
252 /* The number of references to this value. When a value is created,
253 the value chain holds a reference, so REFERENCE_COUNT is 1. If
254 release_value is called, this value is removed from the chain but
255 the caller of release_value now has a reference to this value.
256 The caller must arrange for a call to value_free later. */
259 /* Only used for bitfields; the containing value. This allows a
260 single read from the target when displaying multiple
262 struct value
*parent
;
264 /* Frame register value is relative to. This will be described in
265 the lval enum above as "lval_register". */
266 struct frame_id frame_id
;
268 /* Type of the value. */
271 /* If a value represents a C++ object, then the `type' field gives
272 the object's compile-time type. If the object actually belongs
273 to some class derived from `type', perhaps with other base
274 classes and additional members, then `type' is just a subobject
275 of the real thing, and the full object is probably larger than
276 `type' would suggest.
278 If `type' is a dynamic class (i.e. one with a vtable), then GDB
279 can actually determine the object's run-time type by looking at
280 the run-time type information in the vtable. When this
281 information is available, we may elect to read in the entire
282 object, for several reasons:
284 - When printing the value, the user would probably rather see the
285 full object, not just the limited portion apparent from the
288 - If `type' has virtual base classes, then even printing `type'
289 alone may require reaching outside the `type' portion of the
290 object to wherever the virtual base class has been stored.
292 When we store the entire object, `enclosing_type' is the run-time
293 type -- the complete object -- and `embedded_offset' is the
294 offset of `type' within that larger type, in bytes. The
295 value_contents() macro takes `embedded_offset' into account, so
296 most GDB code continues to see the `type' portion of the value,
297 just as the inferior would.
299 If `type' is a pointer to an object, then `enclosing_type' is a
300 pointer to the object's run-time type, and `pointed_to_offset' is
301 the offset in bytes from the full object to the pointed-to object
302 -- that is, the value `embedded_offset' would have if we followed
303 the pointer and fetched the complete object. (I don't really see
304 the point. Why not just determine the run-time type when you
305 indirect, and avoid the special case? The contents don't matter
306 until you indirect anyway.)
308 If we're not doing anything fancy, `enclosing_type' is equal to
309 `type', and `embedded_offset' is zero, so everything works
311 struct type
*enclosing_type
;
313 int pointed_to_offset
;
315 /* Values are stored in a chain, so that they can be deleted easily
316 over calls to the inferior. Values assigned to internal
317 variables, put into the value history or exposed to Python are
318 taken off this list. */
321 /* Register number if the value is from a register. */
324 /* Actual contents of the value. Target byte-order. NULL or not
325 valid if lazy is nonzero. */
328 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
329 rather than available, since the common and default case is for a
330 value to be available. This is filled in at value read time. */
331 VEC(range_s
) *unavailable
;
335 value_bytes_available (const struct value
*value
, int offset
, int length
)
337 gdb_assert (!value
->lazy
);
339 return !ranges_contain (value
->unavailable
, offset
, length
);
343 value_entirely_available (struct value
*value
)
345 /* We can only tell whether the whole value is available when we try
348 value_fetch_lazy (value
);
350 if (VEC_empty (range_s
, value
->unavailable
))
356 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
361 /* Insert the range sorted. If there's overlap or the new range
362 would be contiguous with an existing range, merge. */
364 newr
.offset
= offset
;
365 newr
.length
= length
;
367 /* Do a binary search for the position the given range would be
368 inserted if we only considered the starting OFFSET of ranges.
369 Call that position I. Since we also have LENGTH to care for
370 (this is a range afterall), we need to check if the _previous_
371 range overlaps the I range. E.g., calling R the new range:
373 #1 - overlaps with previous
377 |---| |---| |------| ... |--|
382 In the case #1 above, the binary search would return `I=1',
383 meaning, this OFFSET should be inserted at position 1, and the
384 current position 1 should be pushed further (and become 2). But,
385 note that `0' overlaps with R, so we want to merge them.
387 A similar consideration needs to be taken if the new range would
388 be contiguous with the previous range:
390 #2 - contiguous with previous
394 |--| |---| |------| ... |--|
399 If there's no overlap with the previous range, as in:
401 #3 - not overlapping and not contiguous
405 |--| |---| |------| ... |--|
412 #4 - R is the range with lowest offset
416 |--| |---| |------| ... |--|
421 ... we just push the new range to I.
423 All the 4 cases above need to consider that the new range may
424 also overlap several of the ranges that follow, or that R may be
425 contiguous with the following range, and merge. E.g.,
427 #5 - overlapping following ranges
430 |------------------------|
431 |--| |---| |------| ... |--|
440 |--| |---| |------| ... |--|
447 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
450 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
452 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
455 ULONGEST l
= min (bef
->offset
, offset
);
456 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
462 else if (offset
== bef
->offset
+ bef
->length
)
465 bef
->length
+= length
;
471 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
477 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
480 /* Check whether the ranges following the one we've just added or
481 touched can be folded in (#5 above). */
482 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
489 /* Get the range we just touched. */
490 t
= VEC_index (range_s
, value
->unavailable
, i
);
494 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
495 if (r
->offset
<= t
->offset
+ t
->length
)
499 l
= min (t
->offset
, r
->offset
);
500 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
509 /* If we couldn't merge this one, we won't be able to
510 merge following ones either, since the ranges are
511 always sorted by OFFSET. */
516 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
520 /* Find the first range in RANGES that overlaps the range defined by
521 OFFSET and LENGTH, starting at element POS in the RANGES vector,
522 Returns the index into RANGES where such overlapping range was
523 found, or -1 if none was found. */
526 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
527 int offset
, int length
)
532 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
533 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
540 value_available_contents_eq (const struct value
*val1
, int offset1
,
541 const struct value
*val2
, int offset2
,
544 int idx1
= 0, idx2
= 0;
546 /* This routine is used by printing routines, where we should
547 already have read the value. Note that we only know whether a
548 value chunk is available if we've tried to read it. */
549 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
557 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
559 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
562 /* The usual case is for both values to be completely available. */
563 if (idx1
== -1 && idx2
== -1)
564 return (memcmp (val1
->contents
+ offset1
,
565 val2
->contents
+ offset2
,
567 /* The contents only match equal if the available set matches as
569 else if (idx1
== -1 || idx2
== -1)
572 gdb_assert (idx1
!= -1 && idx2
!= -1);
574 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
575 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
577 /* Get the unavailable windows intersected by the incoming
578 ranges. The first and last ranges that overlap the argument
579 range may be wider than said incoming arguments ranges. */
580 l1
= max (offset1
, r1
->offset
);
581 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
583 l2
= max (offset2
, r2
->offset
);
584 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
586 /* Make them relative to the respective start offsets, so we can
587 compare them for equality. */
594 /* Different availability, no match. */
595 if (l1
!= l2
|| h1
!= h2
)
598 /* Compare the _available_ contents. */
599 if (memcmp (val1
->contents
+ offset1
,
600 val2
->contents
+ offset2
,
612 /* Prototypes for local functions. */
614 static void show_values (char *, int);
616 static void show_convenience (char *, int);
619 /* The value-history records all the values printed
620 by print commands during this session. Each chunk
621 records 60 consecutive values. The first chunk on
622 the chain records the most recent values.
623 The total number of values is in value_history_count. */
625 #define VALUE_HISTORY_CHUNK 60
627 struct value_history_chunk
629 struct value_history_chunk
*next
;
630 struct value
*values
[VALUE_HISTORY_CHUNK
];
633 /* Chain of chunks now in use. */
635 static struct value_history_chunk
*value_history_chain
;
637 static int value_history_count
; /* Abs number of last entry stored. */
640 /* List of all value objects currently allocated
641 (except for those released by calls to release_value)
642 This is so they can be freed after each command. */
644 static struct value
*all_values
;
646 /* Allocate a lazy value for type TYPE. Its actual content is
647 "lazily" allocated too: the content field of the return value is
648 NULL; it will be allocated when it is fetched from the target. */
651 allocate_value_lazy (struct type
*type
)
655 /* Call check_typedef on our type to make sure that, if TYPE
656 is a TYPE_CODE_TYPEDEF, its length is set to the length
657 of the target type instead of zero. However, we do not
658 replace the typedef type by the target type, because we want
659 to keep the typedef in order to be able to set the VAL's type
660 description correctly. */
661 check_typedef (type
);
663 val
= (struct value
*) xzalloc (sizeof (struct value
));
664 val
->contents
= NULL
;
665 val
->next
= all_values
;
668 val
->enclosing_type
= type
;
669 VALUE_LVAL (val
) = not_lval
;
670 val
->location
.address
= 0;
671 VALUE_FRAME_ID (val
) = null_frame_id
;
675 VALUE_REGNUM (val
) = -1;
677 val
->optimized_out
= 0;
678 val
->embedded_offset
= 0;
679 val
->pointed_to_offset
= 0;
681 val
->initialized
= 1; /* Default to initialized. */
683 /* Values start out on the all_values chain. */
684 val
->reference_count
= 1;
689 /* Allocate the contents of VAL if it has not been allocated yet. */
692 allocate_value_contents (struct value
*val
)
695 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
698 /* Allocate a value and its contents for type TYPE. */
701 allocate_value (struct type
*type
)
703 struct value
*val
= allocate_value_lazy (type
);
705 allocate_value_contents (val
);
710 /* Allocate a value that has the correct length
711 for COUNT repetitions of type TYPE. */
714 allocate_repeat_value (struct type
*type
, int count
)
716 int low_bound
= current_language
->string_lower_bound
; /* ??? */
717 /* FIXME-type-allocation: need a way to free this type when we are
719 struct type
*array_type
720 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
722 return allocate_value (array_type
);
726 allocate_computed_value (struct type
*type
,
727 const struct lval_funcs
*funcs
,
730 struct value
*v
= allocate_value_lazy (type
);
732 VALUE_LVAL (v
) = lval_computed
;
733 v
->location
.computed
.funcs
= funcs
;
734 v
->location
.computed
.closure
= closure
;
739 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
742 allocate_optimized_out_value (struct type
*type
)
744 struct value
*retval
= allocate_value_lazy (type
);
746 set_value_optimized_out (retval
, 1);
751 /* Accessor methods. */
754 value_next (struct value
*value
)
760 value_type (const struct value
*value
)
765 deprecated_set_value_type (struct value
*value
, struct type
*type
)
771 value_offset (const struct value
*value
)
773 return value
->offset
;
776 set_value_offset (struct value
*value
, int offset
)
778 value
->offset
= offset
;
782 value_bitpos (const struct value
*value
)
784 return value
->bitpos
;
787 set_value_bitpos (struct value
*value
, int bit
)
793 value_bitsize (const struct value
*value
)
795 return value
->bitsize
;
798 set_value_bitsize (struct value
*value
, int bit
)
800 value
->bitsize
= bit
;
804 value_parent (struct value
*value
)
806 return value
->parent
;
812 set_value_parent (struct value
*value
, struct value
*parent
)
814 struct value
*old
= value
->parent
;
816 value
->parent
= parent
;
818 value_incref (parent
);
823 value_contents_raw (struct value
*value
)
825 allocate_value_contents (value
);
826 return value
->contents
+ value
->embedded_offset
;
830 value_contents_all_raw (struct value
*value
)
832 allocate_value_contents (value
);
833 return value
->contents
;
837 value_enclosing_type (struct value
*value
)
839 return value
->enclosing_type
;
842 /* Look at value.h for description. */
845 value_actual_type (struct value
*value
, int resolve_simple_types
,
846 int *real_type_found
)
848 struct value_print_options opts
;
851 get_user_print_options (&opts
);
854 *real_type_found
= 0;
855 result
= value_type (value
);
856 if (opts
.objectprint
)
858 /* If result's target type is TYPE_CODE_STRUCT, proceed to
859 fetch its rtti type. */
860 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
861 || TYPE_CODE (result
) == TYPE_CODE_REF
)
862 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
865 struct type
*real_type
;
867 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
871 *real_type_found
= 1;
875 else if (resolve_simple_types
)
878 *real_type_found
= 1;
879 result
= value_enclosing_type (value
);
887 require_not_optimized_out (const struct value
*value
)
889 if (value
->optimized_out
)
890 error (_("value has been optimized out"));
894 require_available (const struct value
*value
)
896 if (!VEC_empty (range_s
, value
->unavailable
))
897 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
901 value_contents_for_printing (struct value
*value
)
904 value_fetch_lazy (value
);
905 return value
->contents
;
909 value_contents_for_printing_const (const struct value
*value
)
911 gdb_assert (!value
->lazy
);
912 return value
->contents
;
916 value_contents_all (struct value
*value
)
918 const gdb_byte
*result
= value_contents_for_printing (value
);
919 require_not_optimized_out (value
);
920 require_available (value
);
924 /* Copy LENGTH bytes of SRC value's (all) contents
925 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
926 contents, starting at DST_OFFSET. If unavailable contents are
927 being copied from SRC, the corresponding DST contents are marked
928 unavailable accordingly. Neither DST nor SRC may be lazy
931 It is assumed the contents of DST in the [DST_OFFSET,
932 DST_OFFSET+LENGTH) range are wholly available. */
935 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
936 struct value
*src
, int src_offset
, int length
)
941 /* A lazy DST would make that this copy operation useless, since as
942 soon as DST's contents were un-lazied (by a later value_contents
943 call, say), the contents would be overwritten. A lazy SRC would
944 mean we'd be copying garbage. */
945 gdb_assert (!dst
->lazy
&& !src
->lazy
);
947 /* The overwritten DST range gets unavailability ORed in, not
948 replaced. Make sure to remember to implement replacing if it
949 turns out actually necessary. */
950 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
953 memcpy (value_contents_all_raw (dst
) + dst_offset
,
954 value_contents_all_raw (src
) + src_offset
,
957 /* Copy the meta-data, adjusted. */
958 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
962 l
= max (r
->offset
, src_offset
);
963 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
966 mark_value_bytes_unavailable (dst
,
967 dst_offset
+ (l
- src_offset
),
972 /* Copy LENGTH bytes of SRC value's (all) contents
973 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
974 (all) contents, starting at DST_OFFSET. If unavailable contents
975 are being copied from SRC, the corresponding DST contents are
976 marked unavailable accordingly. DST must not be lazy. If SRC is
977 lazy, it will be fetched now. If SRC is not valid (is optimized
978 out), an error is thrown.
980 It is assumed the contents of DST in the [DST_OFFSET,
981 DST_OFFSET+LENGTH) range are wholly available. */
984 value_contents_copy (struct value
*dst
, int dst_offset
,
985 struct value
*src
, int src_offset
, int length
)
987 require_not_optimized_out (src
);
990 value_fetch_lazy (src
);
992 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
996 value_lazy (struct value
*value
)
1002 set_value_lazy (struct value
*value
, int val
)
1008 value_stack (struct value
*value
)
1010 return value
->stack
;
1014 set_value_stack (struct value
*value
, int val
)
1020 value_contents (struct value
*value
)
1022 const gdb_byte
*result
= value_contents_writeable (value
);
1023 require_not_optimized_out (value
);
1024 require_available (value
);
1029 value_contents_writeable (struct value
*value
)
1032 value_fetch_lazy (value
);
1033 return value_contents_raw (value
);
1036 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1037 this function is different from value_equal; in C the operator ==
1038 can return 0 even if the two values being compared are equal. */
1041 value_contents_equal (struct value
*val1
, struct value
*val2
)
1046 type1
= check_typedef (value_type (val1
));
1047 type2
= check_typedef (value_type (val2
));
1048 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1051 return (memcmp (value_contents (val1
), value_contents (val2
),
1052 TYPE_LENGTH (type1
)) == 0);
1056 value_optimized_out (struct value
*value
)
1058 return value
->optimized_out
;
1062 set_value_optimized_out (struct value
*value
, int val
)
1064 value
->optimized_out
= val
;
1068 value_entirely_optimized_out (const struct value
*value
)
1070 if (!value
->optimized_out
)
1072 if (value
->lval
!= lval_computed
1073 || !value
->location
.computed
.funcs
->check_any_valid
)
1075 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1079 value_bits_valid (const struct value
*value
, int offset
, int length
)
1081 if (!value
->optimized_out
)
1083 if (value
->lval
!= lval_computed
1084 || !value
->location
.computed
.funcs
->check_validity
)
1086 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1091 value_bits_synthetic_pointer (const struct value
*value
,
1092 int offset
, int length
)
1094 if (value
->lval
!= lval_computed
1095 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1097 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1103 value_embedded_offset (struct value
*value
)
1105 return value
->embedded_offset
;
1109 set_value_embedded_offset (struct value
*value
, int val
)
1111 value
->embedded_offset
= val
;
1115 value_pointed_to_offset (struct value
*value
)
1117 return value
->pointed_to_offset
;
1121 set_value_pointed_to_offset (struct value
*value
, int val
)
1123 value
->pointed_to_offset
= val
;
1126 const struct lval_funcs
*
1127 value_computed_funcs (const struct value
*v
)
1129 gdb_assert (value_lval_const (v
) == lval_computed
);
1131 return v
->location
.computed
.funcs
;
1135 value_computed_closure (const struct value
*v
)
1137 gdb_assert (v
->lval
== lval_computed
);
1139 return v
->location
.computed
.closure
;
1143 deprecated_value_lval_hack (struct value
*value
)
1145 return &value
->lval
;
1149 value_lval_const (const struct value
*value
)
1155 value_address (const struct value
*value
)
1157 if (value
->lval
== lval_internalvar
1158 || value
->lval
== lval_internalvar_component
)
1160 if (value
->parent
!= NULL
)
1161 return value_address (value
->parent
) + value
->offset
;
1163 return value
->location
.address
+ value
->offset
;
1167 value_raw_address (struct value
*value
)
1169 if (value
->lval
== lval_internalvar
1170 || value
->lval
== lval_internalvar_component
)
1172 return value
->location
.address
;
1176 set_value_address (struct value
*value
, CORE_ADDR addr
)
1178 gdb_assert (value
->lval
!= lval_internalvar
1179 && value
->lval
!= lval_internalvar_component
);
1180 value
->location
.address
= addr
;
1183 struct internalvar
**
1184 deprecated_value_internalvar_hack (struct value
*value
)
1186 return &value
->location
.internalvar
;
1190 deprecated_value_frame_id_hack (struct value
*value
)
1192 return &value
->frame_id
;
1196 deprecated_value_regnum_hack (struct value
*value
)
1198 return &value
->regnum
;
1202 deprecated_value_modifiable (struct value
*value
)
1204 return value
->modifiable
;
1207 /* Return a mark in the value chain. All values allocated after the
1208 mark is obtained (except for those released) are subject to being freed
1209 if a subsequent value_free_to_mark is passed the mark. */
1216 /* Take a reference to VAL. VAL will not be deallocated until all
1217 references are released. */
1220 value_incref (struct value
*val
)
1222 val
->reference_count
++;
1225 /* Release a reference to VAL, which was acquired with value_incref.
1226 This function is also called to deallocate values from the value
1230 value_free (struct value
*val
)
1234 gdb_assert (val
->reference_count
> 0);
1235 val
->reference_count
--;
1236 if (val
->reference_count
> 0)
1239 /* If there's an associated parent value, drop our reference to
1241 if (val
->parent
!= NULL
)
1242 value_free (val
->parent
);
1244 if (VALUE_LVAL (val
) == lval_computed
)
1246 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1248 if (funcs
->free_closure
)
1249 funcs
->free_closure (val
);
1252 xfree (val
->contents
);
1253 VEC_free (range_s
, val
->unavailable
);
1258 /* Free all values allocated since MARK was obtained by value_mark
1259 (except for those released). */
1261 value_free_to_mark (struct value
*mark
)
1266 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1275 /* Free all the values that have been allocated (except for those released).
1276 Call after each command, successful or not.
1277 In practice this is called before each command, which is sufficient. */
1280 free_all_values (void)
1285 for (val
= all_values
; val
; val
= next
)
1295 /* Frees all the elements in a chain of values. */
1298 free_value_chain (struct value
*v
)
1304 next
= value_next (v
);
1309 /* Remove VAL from the chain all_values
1310 so it will not be freed automatically. */
1313 release_value (struct value
*val
)
1317 if (all_values
== val
)
1319 all_values
= val
->next
;
1325 for (v
= all_values
; v
; v
= v
->next
)
1329 v
->next
= val
->next
;
1337 /* If the value is not already released, release it.
1338 If the value is already released, increment its reference count.
1339 That is, this function ensures that the value is released from the
1340 value chain and that the caller owns a reference to it. */
1343 release_value_or_incref (struct value
*val
)
1348 release_value (val
);
1351 /* Release all values up to mark */
1353 value_release_to_mark (struct value
*mark
)
1358 for (val
= next
= all_values
; next
; next
= next
->next
)
1360 if (next
->next
== mark
)
1362 all_values
= next
->next
;
1372 /* Return a copy of the value ARG.
1373 It contains the same contents, for same memory address,
1374 but it's a different block of storage. */
1377 value_copy (struct value
*arg
)
1379 struct type
*encl_type
= value_enclosing_type (arg
);
1382 if (value_lazy (arg
))
1383 val
= allocate_value_lazy (encl_type
);
1385 val
= allocate_value (encl_type
);
1386 val
->type
= arg
->type
;
1387 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1388 val
->location
= arg
->location
;
1389 val
->offset
= arg
->offset
;
1390 val
->bitpos
= arg
->bitpos
;
1391 val
->bitsize
= arg
->bitsize
;
1392 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1393 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1394 val
->lazy
= arg
->lazy
;
1395 val
->optimized_out
= arg
->optimized_out
;
1396 val
->embedded_offset
= value_embedded_offset (arg
);
1397 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1398 val
->modifiable
= arg
->modifiable
;
1399 if (!value_lazy (val
))
1401 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1402 TYPE_LENGTH (value_enclosing_type (arg
)));
1405 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1406 set_value_parent (val
, arg
->parent
);
1407 if (VALUE_LVAL (val
) == lval_computed
)
1409 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1411 if (funcs
->copy_closure
)
1412 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1417 /* Return a version of ARG that is non-lvalue. */
1420 value_non_lval (struct value
*arg
)
1422 if (VALUE_LVAL (arg
) != not_lval
)
1424 struct type
*enc_type
= value_enclosing_type (arg
);
1425 struct value
*val
= allocate_value (enc_type
);
1427 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1428 TYPE_LENGTH (enc_type
));
1429 val
->type
= arg
->type
;
1430 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1431 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1438 set_value_component_location (struct value
*component
,
1439 const struct value
*whole
)
1441 if (whole
->lval
== lval_internalvar
)
1442 VALUE_LVAL (component
) = lval_internalvar_component
;
1444 VALUE_LVAL (component
) = whole
->lval
;
1446 component
->location
= whole
->location
;
1447 if (whole
->lval
== lval_computed
)
1449 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1451 if (funcs
->copy_closure
)
1452 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1457 /* Access to the value history. */
1459 /* Record a new value in the value history.
1460 Returns the absolute history index of the entry.
1461 Result of -1 indicates the value was not saved; otherwise it is the
1462 value history index of this new item. */
1465 record_latest_value (struct value
*val
)
1469 /* We don't want this value to have anything to do with the inferior anymore.
1470 In particular, "set $1 = 50" should not affect the variable from which
1471 the value was taken, and fast watchpoints should be able to assume that
1472 a value on the value history never changes. */
1473 if (value_lazy (val
))
1474 value_fetch_lazy (val
);
1475 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1476 from. This is a bit dubious, because then *&$1 does not just return $1
1477 but the current contents of that location. c'est la vie... */
1478 val
->modifiable
= 0;
1479 release_value (val
);
1481 /* Here we treat value_history_count as origin-zero
1482 and applying to the value being stored now. */
1484 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1487 struct value_history_chunk
*new
1488 = (struct value_history_chunk
*)
1490 xmalloc (sizeof (struct value_history_chunk
));
1491 memset (new->values
, 0, sizeof new->values
);
1492 new->next
= value_history_chain
;
1493 value_history_chain
= new;
1496 value_history_chain
->values
[i
] = val
;
1498 /* Now we regard value_history_count as origin-one
1499 and applying to the value just stored. */
1501 return ++value_history_count
;
1504 /* Return a copy of the value in the history with sequence number NUM. */
1507 access_value_history (int num
)
1509 struct value_history_chunk
*chunk
;
1514 absnum
+= value_history_count
;
1519 error (_("The history is empty."));
1521 error (_("There is only one value in the history."));
1523 error (_("History does not go back to $$%d."), -num
);
1525 if (absnum
> value_history_count
)
1526 error (_("History has not yet reached $%d."), absnum
);
1530 /* Now absnum is always absolute and origin zero. */
1532 chunk
= value_history_chain
;
1533 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1534 - absnum
/ VALUE_HISTORY_CHUNK
;
1536 chunk
= chunk
->next
;
1538 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1542 show_values (char *num_exp
, int from_tty
)
1550 /* "show values +" should print from the stored position.
1551 "show values <exp>" should print around value number <exp>. */
1552 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1553 num
= parse_and_eval_long (num_exp
) - 5;
1557 /* "show values" means print the last 10 values. */
1558 num
= value_history_count
- 9;
1564 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1566 struct value_print_options opts
;
1568 val
= access_value_history (i
);
1569 printf_filtered (("$%d = "), i
);
1570 get_user_print_options (&opts
);
1571 value_print (val
, gdb_stdout
, &opts
);
1572 printf_filtered (("\n"));
1575 /* The next "show values +" should start after what we just printed. */
1578 /* Hitting just return after this command should do the same thing as
1579 "show values +". If num_exp is null, this is unnecessary, since
1580 "show values +" is not useful after "show values". */
1581 if (from_tty
&& num_exp
)
1588 /* Internal variables. These are variables within the debugger
1589 that hold values assigned by debugger commands.
1590 The user refers to them with a '$' prefix
1591 that does not appear in the variable names stored internally. */
1595 struct internalvar
*next
;
1598 /* We support various different kinds of content of an internal variable.
1599 enum internalvar_kind specifies the kind, and union internalvar_data
1600 provides the data associated with this particular kind. */
1602 enum internalvar_kind
1604 /* The internal variable is empty. */
1607 /* The value of the internal variable is provided directly as
1608 a GDB value object. */
1611 /* A fresh value is computed via a call-back routine on every
1612 access to the internal variable. */
1613 INTERNALVAR_MAKE_VALUE
,
1615 /* The internal variable holds a GDB internal convenience function. */
1616 INTERNALVAR_FUNCTION
,
1618 /* The variable holds an integer value. */
1619 INTERNALVAR_INTEGER
,
1621 /* The variable holds a GDB-provided string. */
1626 union internalvar_data
1628 /* A value object used with INTERNALVAR_VALUE. */
1629 struct value
*value
;
1631 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1634 /* The functions to call. */
1635 const struct internalvar_funcs
*functions
;
1637 /* The function's user-data. */
1641 /* The internal function used with INTERNALVAR_FUNCTION. */
1644 struct internal_function
*function
;
1645 /* True if this is the canonical name for the function. */
1649 /* An integer value used with INTERNALVAR_INTEGER. */
1652 /* If type is non-NULL, it will be used as the type to generate
1653 a value for this internal variable. If type is NULL, a default
1654 integer type for the architecture is used. */
1659 /* A string value used with INTERNALVAR_STRING. */
1664 static struct internalvar
*internalvars
;
1666 /* If the variable does not already exist create it and give it the
1667 value given. If no value is given then the default is zero. */
1669 init_if_undefined_command (char* args
, int from_tty
)
1671 struct internalvar
* intvar
;
1673 /* Parse the expression - this is taken from set_command(). */
1674 struct expression
*expr
= parse_expression (args
);
1675 register struct cleanup
*old_chain
=
1676 make_cleanup (free_current_contents
, &expr
);
1678 /* Validate the expression.
1679 Was the expression an assignment?
1680 Or even an expression at all? */
1681 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1682 error (_("Init-if-undefined requires an assignment expression."));
1684 /* Extract the variable from the parsed expression.
1685 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1686 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1687 error (_("The first parameter to init-if-undefined "
1688 "should be a GDB variable."));
1689 intvar
= expr
->elts
[2].internalvar
;
1691 /* Only evaluate the expression if the lvalue is void.
1692 This may still fail if the expresssion is invalid. */
1693 if (intvar
->kind
== INTERNALVAR_VOID
)
1694 evaluate_expression (expr
);
1696 do_cleanups (old_chain
);
1700 /* Look up an internal variable with name NAME. NAME should not
1701 normally include a dollar sign.
1703 If the specified internal variable does not exist,
1704 the return value is NULL. */
1706 struct internalvar
*
1707 lookup_only_internalvar (const char *name
)
1709 struct internalvar
*var
;
1711 for (var
= internalvars
; var
; var
= var
->next
)
1712 if (strcmp (var
->name
, name
) == 0)
1718 /* Complete NAME by comparing it to the names of internal variables.
1719 Returns a vector of newly allocated strings, or NULL if no matches
1723 complete_internalvar (const char *name
)
1725 VEC (char_ptr
) *result
= NULL
;
1726 struct internalvar
*var
;
1729 len
= strlen (name
);
1731 for (var
= internalvars
; var
; var
= var
->next
)
1732 if (strncmp (var
->name
, name
, len
) == 0)
1734 char *r
= xstrdup (var
->name
);
1736 VEC_safe_push (char_ptr
, result
, r
);
1742 /* Create an internal variable with name NAME and with a void value.
1743 NAME should not normally include a dollar sign. */
1745 struct internalvar
*
1746 create_internalvar (const char *name
)
1748 struct internalvar
*var
;
1750 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1751 var
->name
= concat (name
, (char *)NULL
);
1752 var
->kind
= INTERNALVAR_VOID
;
1753 var
->next
= internalvars
;
1758 /* Create an internal variable with name NAME and register FUN as the
1759 function that value_of_internalvar uses to create a value whenever
1760 this variable is referenced. NAME should not normally include a
1761 dollar sign. DATA is passed uninterpreted to FUN when it is
1762 called. CLEANUP, if not NULL, is called when the internal variable
1763 is destroyed. It is passed DATA as its only argument. */
1765 struct internalvar
*
1766 create_internalvar_type_lazy (const char *name
,
1767 const struct internalvar_funcs
*funcs
,
1770 struct internalvar
*var
= create_internalvar (name
);
1772 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1773 var
->u
.make_value
.functions
= funcs
;
1774 var
->u
.make_value
.data
= data
;
1778 /* See documentation in value.h. */
1781 compile_internalvar_to_ax (struct internalvar
*var
,
1782 struct agent_expr
*expr
,
1783 struct axs_value
*value
)
1785 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1786 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1789 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1790 var
->u
.make_value
.data
);
1794 /* Look up an internal variable with name NAME. NAME should not
1795 normally include a dollar sign.
1797 If the specified internal variable does not exist,
1798 one is created, with a void value. */
1800 struct internalvar
*
1801 lookup_internalvar (const char *name
)
1803 struct internalvar
*var
;
1805 var
= lookup_only_internalvar (name
);
1809 return create_internalvar (name
);
1812 /* Return current value of internal variable VAR. For variables that
1813 are not inherently typed, use a value type appropriate for GDBARCH. */
1816 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1819 struct trace_state_variable
*tsv
;
1821 /* If there is a trace state variable of the same name, assume that
1822 is what we really want to see. */
1823 tsv
= find_trace_state_variable (var
->name
);
1826 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1828 if (tsv
->value_known
)
1829 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1832 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1838 case INTERNALVAR_VOID
:
1839 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1842 case INTERNALVAR_FUNCTION
:
1843 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1846 case INTERNALVAR_INTEGER
:
1847 if (!var
->u
.integer
.type
)
1848 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1849 var
->u
.integer
.val
);
1851 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1854 case INTERNALVAR_STRING
:
1855 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1856 builtin_type (gdbarch
)->builtin_char
);
1859 case INTERNALVAR_VALUE
:
1860 val
= value_copy (var
->u
.value
);
1861 if (value_lazy (val
))
1862 value_fetch_lazy (val
);
1865 case INTERNALVAR_MAKE_VALUE
:
1866 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
1867 var
->u
.make_value
.data
);
1871 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1874 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1875 on this value go back to affect the original internal variable.
1877 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1878 no underlying modifyable state in the internal variable.
1880 Likewise, if the variable's value is a computed lvalue, we want
1881 references to it to produce another computed lvalue, where
1882 references and assignments actually operate through the
1883 computed value's functions.
1885 This means that internal variables with computed values
1886 behave a little differently from other internal variables:
1887 assignments to them don't just replace the previous value
1888 altogether. At the moment, this seems like the behavior we
1891 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1892 && val
->lval
!= lval_computed
)
1894 VALUE_LVAL (val
) = lval_internalvar
;
1895 VALUE_INTERNALVAR (val
) = var
;
1902 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1904 if (var
->kind
== INTERNALVAR_INTEGER
)
1906 *result
= var
->u
.integer
.val
;
1910 if (var
->kind
== INTERNALVAR_VALUE
)
1912 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1914 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1916 *result
= value_as_long (var
->u
.value
);
1925 get_internalvar_function (struct internalvar
*var
,
1926 struct internal_function
**result
)
1930 case INTERNALVAR_FUNCTION
:
1931 *result
= var
->u
.fn
.function
;
1940 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1941 int bitsize
, struct value
*newval
)
1947 case INTERNALVAR_VALUE
:
1948 addr
= value_contents_writeable (var
->u
.value
);
1951 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1952 value_as_long (newval
), bitpos
, bitsize
);
1954 memcpy (addr
+ offset
, value_contents (newval
),
1955 TYPE_LENGTH (value_type (newval
)));
1959 /* We can never get a component of any other kind. */
1960 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1965 set_internalvar (struct internalvar
*var
, struct value
*val
)
1967 enum internalvar_kind new_kind
;
1968 union internalvar_data new_data
= { 0 };
1970 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1971 error (_("Cannot overwrite convenience function %s"), var
->name
);
1973 /* Prepare new contents. */
1974 switch (TYPE_CODE (check_typedef (value_type (val
))))
1976 case TYPE_CODE_VOID
:
1977 new_kind
= INTERNALVAR_VOID
;
1980 case TYPE_CODE_INTERNAL_FUNCTION
:
1981 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1982 new_kind
= INTERNALVAR_FUNCTION
;
1983 get_internalvar_function (VALUE_INTERNALVAR (val
),
1984 &new_data
.fn
.function
);
1985 /* Copies created here are never canonical. */
1989 new_kind
= INTERNALVAR_VALUE
;
1990 new_data
.value
= value_copy (val
);
1991 new_data
.value
->modifiable
= 1;
1993 /* Force the value to be fetched from the target now, to avoid problems
1994 later when this internalvar is referenced and the target is gone or
1996 if (value_lazy (new_data
.value
))
1997 value_fetch_lazy (new_data
.value
);
1999 /* Release the value from the value chain to prevent it from being
2000 deleted by free_all_values. From here on this function should not
2001 call error () until new_data is installed into the var->u to avoid
2003 release_value (new_data
.value
);
2007 /* Clean up old contents. */
2008 clear_internalvar (var
);
2011 var
->kind
= new_kind
;
2013 /* End code which must not call error(). */
2017 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2019 /* Clean up old contents. */
2020 clear_internalvar (var
);
2022 var
->kind
= INTERNALVAR_INTEGER
;
2023 var
->u
.integer
.type
= NULL
;
2024 var
->u
.integer
.val
= l
;
2028 set_internalvar_string (struct internalvar
*var
, const char *string
)
2030 /* Clean up old contents. */
2031 clear_internalvar (var
);
2033 var
->kind
= INTERNALVAR_STRING
;
2034 var
->u
.string
= xstrdup (string
);
2038 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2040 /* Clean up old contents. */
2041 clear_internalvar (var
);
2043 var
->kind
= INTERNALVAR_FUNCTION
;
2044 var
->u
.fn
.function
= f
;
2045 var
->u
.fn
.canonical
= 1;
2046 /* Variables installed here are always the canonical version. */
2050 clear_internalvar (struct internalvar
*var
)
2052 /* Clean up old contents. */
2055 case INTERNALVAR_VALUE
:
2056 value_free (var
->u
.value
);
2059 case INTERNALVAR_STRING
:
2060 xfree (var
->u
.string
);
2063 case INTERNALVAR_MAKE_VALUE
:
2064 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2065 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2072 /* Reset to void kind. */
2073 var
->kind
= INTERNALVAR_VOID
;
2077 internalvar_name (struct internalvar
*var
)
2082 static struct internal_function
*
2083 create_internal_function (const char *name
,
2084 internal_function_fn handler
, void *cookie
)
2086 struct internal_function
*ifn
= XNEW (struct internal_function
);
2088 ifn
->name
= xstrdup (name
);
2089 ifn
->handler
= handler
;
2090 ifn
->cookie
= cookie
;
2095 value_internal_function_name (struct value
*val
)
2097 struct internal_function
*ifn
;
2100 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2101 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2102 gdb_assert (result
);
2108 call_internal_function (struct gdbarch
*gdbarch
,
2109 const struct language_defn
*language
,
2110 struct value
*func
, int argc
, struct value
**argv
)
2112 struct internal_function
*ifn
;
2115 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2116 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2117 gdb_assert (result
);
2119 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2122 /* The 'function' command. This does nothing -- it is just a
2123 placeholder to let "help function NAME" work. This is also used as
2124 the implementation of the sub-command that is created when
2125 registering an internal function. */
2127 function_command (char *command
, int from_tty
)
2132 /* Clean up if an internal function's command is destroyed. */
2134 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2136 xfree ((char *) self
->name
);
2140 /* Add a new internal function. NAME is the name of the function; DOC
2141 is a documentation string describing the function. HANDLER is
2142 called when the function is invoked. COOKIE is an arbitrary
2143 pointer which is passed to HANDLER and is intended for "user
2146 add_internal_function (const char *name
, const char *doc
,
2147 internal_function_fn handler
, void *cookie
)
2149 struct cmd_list_element
*cmd
;
2150 struct internal_function
*ifn
;
2151 struct internalvar
*var
= lookup_internalvar (name
);
2153 ifn
= create_internal_function (name
, handler
, cookie
);
2154 set_internalvar_function (var
, ifn
);
2156 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2158 cmd
->destroyer
= function_destroyer
;
2161 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2162 prevent cycles / duplicates. */
2165 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2166 htab_t copied_types
)
2168 if (TYPE_OBJFILE (value
->type
) == objfile
)
2169 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2171 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2172 value
->enclosing_type
= copy_type_recursive (objfile
,
2173 value
->enclosing_type
,
2177 /* Likewise for internal variable VAR. */
2180 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2181 htab_t copied_types
)
2185 case INTERNALVAR_INTEGER
:
2186 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2188 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2191 case INTERNALVAR_VALUE
:
2192 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2197 /* Update the internal variables and value history when OBJFILE is
2198 discarded; we must copy the types out of the objfile. New global types
2199 will be created for every convenience variable which currently points to
2200 this objfile's types, and the convenience variables will be adjusted to
2201 use the new global types. */
2204 preserve_values (struct objfile
*objfile
)
2206 htab_t copied_types
;
2207 struct value_history_chunk
*cur
;
2208 struct internalvar
*var
;
2211 /* Create the hash table. We allocate on the objfile's obstack, since
2212 it is soon to be deleted. */
2213 copied_types
= create_copied_types_hash (objfile
);
2215 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2216 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2218 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2220 for (var
= internalvars
; var
; var
= var
->next
)
2221 preserve_one_internalvar (var
, objfile
, copied_types
);
2223 preserve_python_values (objfile
, copied_types
);
2225 htab_delete (copied_types
);
2229 show_convenience (char *ignore
, int from_tty
)
2231 struct gdbarch
*gdbarch
= get_current_arch ();
2232 struct internalvar
*var
;
2234 struct value_print_options opts
;
2236 get_user_print_options (&opts
);
2237 for (var
= internalvars
; var
; var
= var
->next
)
2239 volatile struct gdb_exception ex
;
2245 printf_filtered (("$%s = "), var
->name
);
2247 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2251 val
= value_of_internalvar (gdbarch
, var
);
2252 value_print (val
, gdb_stdout
, &opts
);
2255 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2256 printf_filtered (("\n"));
2260 /* This text does not mention convenience functions on purpose.
2261 The user can't create them except via Python, and if Python support
2262 is installed this message will never be printed ($_streq will
2264 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2265 "Convenience variables have "
2266 "names starting with \"$\";\n"
2267 "use \"set\" as in \"set "
2268 "$foo = 5\" to define them.\n"));
2272 /* Extract a value as a C number (either long or double).
2273 Knows how to convert fixed values to double, or
2274 floating values to long.
2275 Does not deallocate the value. */
2278 value_as_long (struct value
*val
)
2280 /* This coerces arrays and functions, which is necessary (e.g.
2281 in disassemble_command). It also dereferences references, which
2282 I suspect is the most logical thing to do. */
2283 val
= coerce_array (val
);
2284 return unpack_long (value_type (val
), value_contents (val
));
2288 value_as_double (struct value
*val
)
2293 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2295 error (_("Invalid floating value found in program."));
2299 /* Extract a value as a C pointer. Does not deallocate the value.
2300 Note that val's type may not actually be a pointer; value_as_long
2301 handles all the cases. */
2303 value_as_address (struct value
*val
)
2305 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2307 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2308 whether we want this to be true eventually. */
2310 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2311 non-address (e.g. argument to "signal", "info break", etc.), or
2312 for pointers to char, in which the low bits *are* significant. */
2313 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2316 /* There are several targets (IA-64, PowerPC, and others) which
2317 don't represent pointers to functions as simply the address of
2318 the function's entry point. For example, on the IA-64, a
2319 function pointer points to a two-word descriptor, generated by
2320 the linker, which contains the function's entry point, and the
2321 value the IA-64 "global pointer" register should have --- to
2322 support position-independent code. The linker generates
2323 descriptors only for those functions whose addresses are taken.
2325 On such targets, it's difficult for GDB to convert an arbitrary
2326 function address into a function pointer; it has to either find
2327 an existing descriptor for that function, or call malloc and
2328 build its own. On some targets, it is impossible for GDB to
2329 build a descriptor at all: the descriptor must contain a jump
2330 instruction; data memory cannot be executed; and code memory
2333 Upon entry to this function, if VAL is a value of type `function'
2334 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2335 value_address (val) is the address of the function. This is what
2336 you'll get if you evaluate an expression like `main'. The call
2337 to COERCE_ARRAY below actually does all the usual unary
2338 conversions, which includes converting values of type `function'
2339 to `pointer to function'. This is the challenging conversion
2340 discussed above. Then, `unpack_long' will convert that pointer
2341 back into an address.
2343 So, suppose the user types `disassemble foo' on an architecture
2344 with a strange function pointer representation, on which GDB
2345 cannot build its own descriptors, and suppose further that `foo'
2346 has no linker-built descriptor. The address->pointer conversion
2347 will signal an error and prevent the command from running, even
2348 though the next step would have been to convert the pointer
2349 directly back into the same address.
2351 The following shortcut avoids this whole mess. If VAL is a
2352 function, just return its address directly. */
2353 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2354 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2355 return value_address (val
);
2357 val
= coerce_array (val
);
2359 /* Some architectures (e.g. Harvard), map instruction and data
2360 addresses onto a single large unified address space. For
2361 instance: An architecture may consider a large integer in the
2362 range 0x10000000 .. 0x1000ffff to already represent a data
2363 addresses (hence not need a pointer to address conversion) while
2364 a small integer would still need to be converted integer to
2365 pointer to address. Just assume such architectures handle all
2366 integer conversions in a single function. */
2370 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2371 must admonish GDB hackers to make sure its behavior matches the
2372 compiler's, whenever possible.
2374 In general, I think GDB should evaluate expressions the same way
2375 the compiler does. When the user copies an expression out of
2376 their source code and hands it to a `print' command, they should
2377 get the same value the compiler would have computed. Any
2378 deviation from this rule can cause major confusion and annoyance,
2379 and needs to be justified carefully. In other words, GDB doesn't
2380 really have the freedom to do these conversions in clever and
2383 AndrewC pointed out that users aren't complaining about how GDB
2384 casts integers to pointers; they are complaining that they can't
2385 take an address from a disassembly listing and give it to `x/i'.
2386 This is certainly important.
2388 Adding an architecture method like integer_to_address() certainly
2389 makes it possible for GDB to "get it right" in all circumstances
2390 --- the target has complete control over how things get done, so
2391 people can Do The Right Thing for their target without breaking
2392 anyone else. The standard doesn't specify how integers get
2393 converted to pointers; usually, the ABI doesn't either, but
2394 ABI-specific code is a more reasonable place to handle it. */
2396 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2397 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2398 && gdbarch_integer_to_address_p (gdbarch
))
2399 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2400 value_contents (val
));
2402 return unpack_long (value_type (val
), value_contents (val
));
2406 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2407 as a long, or as a double, assuming the raw data is described
2408 by type TYPE. Knows how to convert different sizes of values
2409 and can convert between fixed and floating point. We don't assume
2410 any alignment for the raw data. Return value is in host byte order.
2412 If you want functions and arrays to be coerced to pointers, and
2413 references to be dereferenced, call value_as_long() instead.
2415 C++: It is assumed that the front-end has taken care of
2416 all matters concerning pointers to members. A pointer
2417 to member which reaches here is considered to be equivalent
2418 to an INT (or some size). After all, it is only an offset. */
2421 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2423 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2424 enum type_code code
= TYPE_CODE (type
);
2425 int len
= TYPE_LENGTH (type
);
2426 int nosign
= TYPE_UNSIGNED (type
);
2430 case TYPE_CODE_TYPEDEF
:
2431 return unpack_long (check_typedef (type
), valaddr
);
2432 case TYPE_CODE_ENUM
:
2433 case TYPE_CODE_FLAGS
:
2434 case TYPE_CODE_BOOL
:
2436 case TYPE_CODE_CHAR
:
2437 case TYPE_CODE_RANGE
:
2438 case TYPE_CODE_MEMBERPTR
:
2440 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2442 return extract_signed_integer (valaddr
, len
, byte_order
);
2445 return extract_typed_floating (valaddr
, type
);
2447 case TYPE_CODE_DECFLOAT
:
2448 /* libdecnumber has a function to convert from decimal to integer, but
2449 it doesn't work when the decimal number has a fractional part. */
2450 return decimal_to_doublest (valaddr
, len
, byte_order
);
2454 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2455 whether we want this to be true eventually. */
2456 return extract_typed_address (valaddr
, type
);
2459 error (_("Value can't be converted to integer."));
2461 return 0; /* Placate lint. */
2464 /* Return a double value from the specified type and address.
2465 INVP points to an int which is set to 0 for valid value,
2466 1 for invalid value (bad float format). In either case,
2467 the returned double is OK to use. Argument is in target
2468 format, result is in host format. */
2471 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2473 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2474 enum type_code code
;
2478 *invp
= 0; /* Assume valid. */
2479 CHECK_TYPEDEF (type
);
2480 code
= TYPE_CODE (type
);
2481 len
= TYPE_LENGTH (type
);
2482 nosign
= TYPE_UNSIGNED (type
);
2483 if (code
== TYPE_CODE_FLT
)
2485 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2486 floating-point value was valid (using the macro
2487 INVALID_FLOAT). That test/macro have been removed.
2489 It turns out that only the VAX defined this macro and then
2490 only in a non-portable way. Fixing the portability problem
2491 wouldn't help since the VAX floating-point code is also badly
2492 bit-rotten. The target needs to add definitions for the
2493 methods gdbarch_float_format and gdbarch_double_format - these
2494 exactly describe the target floating-point format. The
2495 problem here is that the corresponding floatformat_vax_f and
2496 floatformat_vax_d values these methods should be set to are
2497 also not defined either. Oops!
2499 Hopefully someone will add both the missing floatformat
2500 definitions and the new cases for floatformat_is_valid (). */
2502 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2508 return extract_typed_floating (valaddr
, type
);
2510 else if (code
== TYPE_CODE_DECFLOAT
)
2511 return decimal_to_doublest (valaddr
, len
, byte_order
);
2514 /* Unsigned -- be sure we compensate for signed LONGEST. */
2515 return (ULONGEST
) unpack_long (type
, valaddr
);
2519 /* Signed -- we are OK with unpack_long. */
2520 return unpack_long (type
, valaddr
);
2524 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2525 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2526 We don't assume any alignment for the raw data. Return value is in
2529 If you want functions and arrays to be coerced to pointers, and
2530 references to be dereferenced, call value_as_address() instead.
2532 C++: It is assumed that the front-end has taken care of
2533 all matters concerning pointers to members. A pointer
2534 to member which reaches here is considered to be equivalent
2535 to an INT (or some size). After all, it is only an offset. */
2538 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2540 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2541 whether we want this to be true eventually. */
2542 return unpack_long (type
, valaddr
);
2546 /* Get the value of the FIELDNO'th field (which must be static) of
2547 TYPE. Return NULL if the field doesn't exist or has been
2551 value_static_field (struct type
*type
, int fieldno
)
2553 struct value
*retval
;
2555 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2557 case FIELD_LOC_KIND_PHYSADDR
:
2558 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2559 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2561 case FIELD_LOC_KIND_PHYSNAME
:
2563 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2564 /* TYPE_FIELD_NAME (type, fieldno); */
2565 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2569 /* With some compilers, e.g. HP aCC, static data members are
2570 reported as non-debuggable symbols. */
2571 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2578 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2579 SYMBOL_VALUE_ADDRESS (msym
));
2583 retval
= value_of_variable (sym
, NULL
);
2587 gdb_assert_not_reached ("unexpected field location kind");
2593 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2594 You have to be careful here, since the size of the data area for the value
2595 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2596 than the old enclosing type, you have to allocate more space for the
2600 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2602 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2604 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2606 val
->enclosing_type
= new_encl_type
;
2609 /* Given a value ARG1 (offset by OFFSET bytes)
2610 of a struct or union type ARG_TYPE,
2611 extract and return the value of one of its (non-static) fields.
2612 FIELDNO says which field. */
2615 value_primitive_field (struct value
*arg1
, int offset
,
2616 int fieldno
, struct type
*arg_type
)
2621 CHECK_TYPEDEF (arg_type
);
2622 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2624 /* Call check_typedef on our type to make sure that, if TYPE
2625 is a TYPE_CODE_TYPEDEF, its length is set to the length
2626 of the target type instead of zero. However, we do not
2627 replace the typedef type by the target type, because we want
2628 to keep the typedef in order to be able to print the type
2629 description correctly. */
2630 check_typedef (type
);
2632 if (value_optimized_out (arg1
))
2633 v
= allocate_optimized_out_value (type
);
2634 else if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2636 /* Handle packed fields.
2638 Create a new value for the bitfield, with bitpos and bitsize
2639 set. If possible, arrange offset and bitpos so that we can
2640 do a single aligned read of the size of the containing type.
2641 Otherwise, adjust offset to the byte containing the first
2642 bit. Assume that the address, offset, and embedded offset
2643 are sufficiently aligned. */
2645 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2646 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2648 v
= allocate_value_lazy (type
);
2649 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2650 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2651 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2652 v
->bitpos
= bitpos
% container_bitsize
;
2654 v
->bitpos
= bitpos
% 8;
2655 v
->offset
= (value_embedded_offset (arg1
)
2657 + (bitpos
- v
->bitpos
) / 8);
2658 set_value_parent (v
, arg1
);
2659 if (!value_lazy (arg1
))
2660 value_fetch_lazy (v
);
2662 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2664 /* This field is actually a base subobject, so preserve the
2665 entire object's contents for later references to virtual
2669 /* Lazy register values with offsets are not supported. */
2670 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2671 value_fetch_lazy (arg1
);
2673 /* We special case virtual inheritance here because this
2674 requires access to the contents, which we would rather avoid
2675 for references to ordinary fields of unavailable values. */
2676 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2677 boffset
= baseclass_offset (arg_type
, fieldno
,
2678 value_contents (arg1
),
2679 value_embedded_offset (arg1
),
2680 value_address (arg1
),
2683 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2685 if (value_lazy (arg1
))
2686 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2689 v
= allocate_value (value_enclosing_type (arg1
));
2690 value_contents_copy_raw (v
, 0, arg1
, 0,
2691 TYPE_LENGTH (value_enclosing_type (arg1
)));
2694 v
->offset
= value_offset (arg1
);
2695 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2699 /* Plain old data member */
2700 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2702 /* Lazy register values with offsets are not supported. */
2703 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2704 value_fetch_lazy (arg1
);
2706 if (value_lazy (arg1
))
2707 v
= allocate_value_lazy (type
);
2710 v
= allocate_value (type
);
2711 value_contents_copy_raw (v
, value_embedded_offset (v
),
2712 arg1
, value_embedded_offset (arg1
) + offset
,
2713 TYPE_LENGTH (type
));
2715 v
->offset
= (value_offset (arg1
) + offset
2716 + value_embedded_offset (arg1
));
2718 set_value_component_location (v
, arg1
);
2719 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2720 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2724 /* Given a value ARG1 of a struct or union type,
2725 extract and return the value of one of its (non-static) fields.
2726 FIELDNO says which field. */
2729 value_field (struct value
*arg1
, int fieldno
)
2731 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2734 /* Return a non-virtual function as a value.
2735 F is the list of member functions which contains the desired method.
2736 J is an index into F which provides the desired method.
2738 We only use the symbol for its address, so be happy with either a
2739 full symbol or a minimal symbol. */
2742 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2743 int j
, struct type
*type
,
2747 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2748 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2750 struct minimal_symbol
*msym
;
2752 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2759 gdb_assert (sym
== NULL
);
2760 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2765 v
= allocate_value (ftype
);
2768 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2772 /* The minimal symbol might point to a function descriptor;
2773 resolve it to the actual code address instead. */
2774 struct objfile
*objfile
= msymbol_objfile (msym
);
2775 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2777 set_value_address (v
,
2778 gdbarch_convert_from_func_ptr_addr
2779 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2784 if (type
!= value_type (*arg1p
))
2785 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2786 value_addr (*arg1p
)));
2788 /* Move the `this' pointer according to the offset.
2789 VALUE_OFFSET (*arg1p) += offset; */
2797 /* Helper function for both unpack_value_bits_as_long and
2798 unpack_bits_as_long. See those functions for more details on the
2799 interface; the only difference is that this function accepts either
2800 a NULL or a non-NULL ORIGINAL_VALUE. */
2803 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2804 int embedded_offset
, int bitpos
, int bitsize
,
2805 const struct value
*original_value
,
2808 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2815 /* Read the minimum number of bytes required; there may not be
2816 enough bytes to read an entire ULONGEST. */
2817 CHECK_TYPEDEF (field_type
);
2819 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2821 bytes_read
= TYPE_LENGTH (field_type
);
2823 read_offset
= bitpos
/ 8;
2825 if (original_value
!= NULL
2826 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2830 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2831 bytes_read
, byte_order
);
2833 /* Extract bits. See comment above. */
2835 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2836 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2838 lsbcount
= (bitpos
% 8);
2841 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2842 If the field is signed, and is negative, then sign extend. */
2844 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2846 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2848 if (!TYPE_UNSIGNED (field_type
))
2850 if (val
& (valmask
^ (valmask
>> 1)))
2861 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2862 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2863 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2864 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2867 Returns false if the value contents are unavailable, otherwise
2868 returns true, indicating a valid value has been stored in *RESULT.
2870 Extracting bits depends on endianness of the machine. Compute the
2871 number of least significant bits to discard. For big endian machines,
2872 we compute the total number of bits in the anonymous object, subtract
2873 off the bit count from the MSB of the object to the MSB of the
2874 bitfield, then the size of the bitfield, which leaves the LSB discard
2875 count. For little endian machines, the discard count is simply the
2876 number of bits from the LSB of the anonymous object to the LSB of the
2879 If the field is signed, we also do sign extension. */
2882 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2883 int embedded_offset
, int bitpos
, int bitsize
,
2884 const struct value
*original_value
,
2887 gdb_assert (original_value
!= NULL
);
2889 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2890 bitpos
, bitsize
, original_value
, result
);
2894 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2895 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2896 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2900 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2901 int embedded_offset
, int fieldno
,
2902 const struct value
*val
, LONGEST
*result
)
2904 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2905 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2906 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2908 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2909 bitpos
, bitsize
, val
,
2913 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2914 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2915 ORIGINAL_VALUE, which must not be NULL. See
2916 unpack_value_bits_as_long for more details. */
2919 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2920 int embedded_offset
, int fieldno
,
2921 const struct value
*val
, LONGEST
*result
)
2923 gdb_assert (val
!= NULL
);
2925 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2926 fieldno
, val
, result
);
2929 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2930 object at VALADDR. See unpack_value_bits_as_long for more details.
2931 This function differs from unpack_value_field_as_long in that it
2932 operates without a struct value object. */
2935 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2939 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2943 /* Return a new value with type TYPE, which is FIELDNO field of the
2944 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2945 of VAL. If the VAL's contents required to extract the bitfield
2946 from are unavailable, the new value is correspondingly marked as
2950 value_field_bitfield (struct type
*type
, int fieldno
,
2951 const gdb_byte
*valaddr
,
2952 int embedded_offset
, const struct value
*val
)
2956 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2959 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2960 struct value
*retval
= allocate_value (field_type
);
2961 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2966 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2970 /* Modify the value of a bitfield. ADDR points to a block of memory in
2971 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2972 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2973 indicate which bits (in target bit order) comprise the bitfield.
2974 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2975 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2978 modify_field (struct type
*type
, gdb_byte
*addr
,
2979 LONGEST fieldval
, int bitpos
, int bitsize
)
2981 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2983 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2986 /* Normalize BITPOS. */
2990 /* If a negative fieldval fits in the field in question, chop
2991 off the sign extension bits. */
2992 if ((~fieldval
& ~(mask
>> 1)) == 0)
2995 /* Warn if value is too big to fit in the field in question. */
2996 if (0 != (fieldval
& ~mask
))
2998 /* FIXME: would like to include fieldval in the message, but
2999 we don't have a sprintf_longest. */
3000 warning (_("Value does not fit in %d bits."), bitsize
);
3002 /* Truncate it, otherwise adjoining fields may be corrupted. */
3006 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3007 false valgrind reports. */
3009 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3010 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3012 /* Shifting for bit field depends on endianness of the target machine. */
3013 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3014 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3016 oword
&= ~(mask
<< bitpos
);
3017 oword
|= fieldval
<< bitpos
;
3019 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3022 /* Pack NUM into BUF using a target format of TYPE. */
3025 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3027 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3030 type
= check_typedef (type
);
3031 len
= TYPE_LENGTH (type
);
3033 switch (TYPE_CODE (type
))
3036 case TYPE_CODE_CHAR
:
3037 case TYPE_CODE_ENUM
:
3038 case TYPE_CODE_FLAGS
:
3039 case TYPE_CODE_BOOL
:
3040 case TYPE_CODE_RANGE
:
3041 case TYPE_CODE_MEMBERPTR
:
3042 store_signed_integer (buf
, len
, byte_order
, num
);
3047 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3051 error (_("Unexpected type (%d) encountered for integer constant."),
3057 /* Pack NUM into BUF using a target format of TYPE. */
3060 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3063 enum bfd_endian byte_order
;
3065 type
= check_typedef (type
);
3066 len
= TYPE_LENGTH (type
);
3067 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3069 switch (TYPE_CODE (type
))
3072 case TYPE_CODE_CHAR
:
3073 case TYPE_CODE_ENUM
:
3074 case TYPE_CODE_FLAGS
:
3075 case TYPE_CODE_BOOL
:
3076 case TYPE_CODE_RANGE
:
3077 case TYPE_CODE_MEMBERPTR
:
3078 store_unsigned_integer (buf
, len
, byte_order
, num
);
3083 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3087 error (_("Unexpected type (%d) encountered "
3088 "for unsigned integer constant."),
3094 /* Convert C numbers into newly allocated values. */
3097 value_from_longest (struct type
*type
, LONGEST num
)
3099 struct value
*val
= allocate_value (type
);
3101 pack_long (value_contents_raw (val
), type
, num
);
3106 /* Convert C unsigned numbers into newly allocated values. */
3109 value_from_ulongest (struct type
*type
, ULONGEST num
)
3111 struct value
*val
= allocate_value (type
);
3113 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3119 /* Create a value representing a pointer of type TYPE to the address
3122 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3124 struct value
*val
= allocate_value (type
);
3126 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3131 /* Create a value of type TYPE whose contents come from VALADDR, if it
3132 is non-null, and whose memory address (in the inferior) is
3136 value_from_contents_and_address (struct type
*type
,
3137 const gdb_byte
*valaddr
,
3142 if (valaddr
== NULL
)
3143 v
= allocate_value_lazy (type
);
3146 v
= allocate_value (type
);
3147 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3149 set_value_address (v
, address
);
3150 VALUE_LVAL (v
) = lval_memory
;
3154 /* Create a value of type TYPE holding the contents CONTENTS.
3155 The new value is `not_lval'. */
3158 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3160 struct value
*result
;
3162 result
= allocate_value (type
);
3163 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3168 value_from_double (struct type
*type
, DOUBLEST num
)
3170 struct value
*val
= allocate_value (type
);
3171 struct type
*base_type
= check_typedef (type
);
3172 enum type_code code
= TYPE_CODE (base_type
);
3174 if (code
== TYPE_CODE_FLT
)
3176 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3179 error (_("Unexpected type encountered for floating constant."));
3185 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3187 struct value
*val
= allocate_value (type
);
3189 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3193 /* Extract a value from the history file. Input will be of the form
3194 $digits or $$digits. See block comment above 'write_dollar_variable'
3198 value_from_history_ref (char *h
, char **endp
)
3210 /* Find length of numeral string. */
3211 for (; isdigit (h
[len
]); len
++)
3214 /* Make sure numeral string is not part of an identifier. */
3215 if (h
[len
] == '_' || isalpha (h
[len
]))
3218 /* Now collect the index value. */
3223 /* For some bizarre reason, "$$" is equivalent to "$$1",
3224 rather than to "$$0" as it ought to be! */
3229 index
= -strtol (&h
[2], endp
, 10);
3235 /* "$" is equivalent to "$0". */
3240 index
= strtol (&h
[1], endp
, 10);
3243 return access_value_history (index
);
3247 coerce_ref_if_computed (const struct value
*arg
)
3249 const struct lval_funcs
*funcs
;
3251 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3254 if (value_lval_const (arg
) != lval_computed
)
3257 funcs
= value_computed_funcs (arg
);
3258 if (funcs
->coerce_ref
== NULL
)
3261 return funcs
->coerce_ref (arg
);
3264 /* Look at value.h for description. */
3267 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3268 struct type
*original_type
,
3269 struct value
*original_value
)
3271 /* Re-adjust type. */
3272 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3274 /* Add embedding info. */
3275 set_value_enclosing_type (value
, enc_type
);
3276 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3278 /* We may be pointing to an object of some derived type. */
3279 return value_full_object (value
, NULL
, 0, 0, 0);
3283 coerce_ref (struct value
*arg
)
3285 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3286 struct value
*retval
;
3287 struct type
*enc_type
;
3289 retval
= coerce_ref_if_computed (arg
);
3293 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3296 enc_type
= check_typedef (value_enclosing_type (arg
));
3297 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3299 retval
= value_at_lazy (enc_type
,
3300 unpack_pointer (value_type (arg
),
3301 value_contents (arg
)));
3302 return readjust_indirect_value_type (retval
, enc_type
,
3303 value_type_arg_tmp
, arg
);
3307 coerce_array (struct value
*arg
)
3311 arg
= coerce_ref (arg
);
3312 type
= check_typedef (value_type (arg
));
3314 switch (TYPE_CODE (type
))
3316 case TYPE_CODE_ARRAY
:
3317 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3318 arg
= value_coerce_array (arg
);
3320 case TYPE_CODE_FUNC
:
3321 arg
= value_coerce_function (arg
);
3328 /* Return the return value convention that will be used for the
3331 enum return_value_convention
3332 struct_return_convention (struct gdbarch
*gdbarch
,
3333 struct value
*function
, struct type
*value_type
)
3335 enum type_code code
= TYPE_CODE (value_type
);
3337 if (code
== TYPE_CODE_ERROR
)
3338 error (_("Function return type unknown."));
3340 /* Probe the architecture for the return-value convention. */
3341 return gdbarch_return_value (gdbarch
, function
, value_type
,
3345 /* Return true if the function returning the specified type is using
3346 the convention of returning structures in memory (passing in the
3347 address as a hidden first parameter). */
3350 using_struct_return (struct gdbarch
*gdbarch
,
3351 struct value
*function
, struct type
*value_type
)
3353 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3354 /* A void return value is never in memory. See also corresponding
3355 code in "print_return_value". */
3358 return (struct_return_convention (gdbarch
, function
, value_type
)
3359 != RETURN_VALUE_REGISTER_CONVENTION
);
3362 /* Set the initialized field in a value struct. */
3365 set_value_initialized (struct value
*val
, int status
)
3367 val
->initialized
= status
;
3370 /* Return the initialized field in a value struct. */
3373 value_initialized (struct value
*val
)
3375 return val
->initialized
;
3379 _initialize_values (void)
3381 add_cmd ("convenience", no_class
, show_convenience
, _("\
3382 Debugger convenience (\"$foo\") variables and functions.\n\
3383 Convenience variables are created when you assign them values;\n\
3384 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3386 A few convenience variables are given values automatically:\n\
3387 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3388 \"$__\" holds the contents of the last address examined with \"x\"."
3391 Convenience functions are defined via the Python API."
3394 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3396 add_cmd ("values", no_set_class
, show_values
, _("\
3397 Elements of value history around item number IDX (or last ten)."),
3400 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3401 Initialize a convenience variable if necessary.\n\
3402 init-if-undefined VARIABLE = EXPRESSION\n\
3403 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3404 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3405 VARIABLE is already initialized."));
3407 add_prefix_cmd ("function", no_class
, function_command
, _("\
3408 Placeholder command for showing help on convenience functions."),
3409 &functionlist
, "function ", 0, &cmdlist
);