1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5 2009, 2010, 2011 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "arch-utils.h"
24 #include "gdb_string.h"
35 #include "gdb_assert.h"
41 #include "cli/cli-decode.h"
43 #include "python/python.h"
45 #include "tracepoint.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
;
174 /* Type of value; either not an lval, or one of the various
175 different possible kinds of lval. */
178 /* Is it modifiable? Only relevant if lval != not_lval. */
181 /* Location of value (if lval). */
184 /* If lval == lval_memory, this is the address in the inferior.
185 If lval == lval_register, this is the byte offset into the
186 registers structure. */
189 /* Pointer to internal variable. */
190 struct internalvar
*internalvar
;
192 /* If lval == lval_computed, this is a set of function pointers
193 to use to access and describe the value, and a closure pointer
197 struct lval_funcs
*funcs
; /* Functions to call. */
198 void *closure
; /* Closure for those functions to use. */
202 /* Describes offset of a value within lval of a structure in bytes.
203 If lval == lval_memory, this is an offset to the address. If
204 lval == lval_register, this is a further offset from
205 location.address within the registers structure. Note also the
206 member embedded_offset below. */
209 /* Only used for bitfields; number of bits contained in them. */
212 /* Only used for bitfields; position of start of field. For
213 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
214 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
217 /* Only used for bitfields; the containing value. This allows a
218 single read from the target when displaying multiple
220 struct value
*parent
;
222 /* Frame register value is relative to. This will be described in
223 the lval enum above as "lval_register". */
224 struct frame_id frame_id
;
226 /* Type of the value. */
229 /* If a value represents a C++ object, then the `type' field gives
230 the object's compile-time type. If the object actually belongs
231 to some class derived from `type', perhaps with other base
232 classes and additional members, then `type' is just a subobject
233 of the real thing, and the full object is probably larger than
234 `type' would suggest.
236 If `type' is a dynamic class (i.e. one with a vtable), then GDB
237 can actually determine the object's run-time type by looking at
238 the run-time type information in the vtable. When this
239 information is available, we may elect to read in the entire
240 object, for several reasons:
242 - When printing the value, the user would probably rather see the
243 full object, not just the limited portion apparent from the
246 - If `type' has virtual base classes, then even printing `type'
247 alone may require reaching outside the `type' portion of the
248 object to wherever the virtual base class has been stored.
250 When we store the entire object, `enclosing_type' is the run-time
251 type -- the complete object -- and `embedded_offset' is the
252 offset of `type' within that larger type, in bytes. The
253 value_contents() macro takes `embedded_offset' into account, so
254 most GDB code continues to see the `type' portion of the value,
255 just as the inferior would.
257 If `type' is a pointer to an object, then `enclosing_type' is a
258 pointer to the object's run-time type, and `pointed_to_offset' is
259 the offset in bytes from the full object to the pointed-to object
260 -- that is, the value `embedded_offset' would have if we followed
261 the pointer and fetched the complete object. (I don't really see
262 the point. Why not just determine the run-time type when you
263 indirect, and avoid the special case? The contents don't matter
264 until you indirect anyway.)
266 If we're not doing anything fancy, `enclosing_type' is equal to
267 `type', and `embedded_offset' is zero, so everything works
269 struct type
*enclosing_type
;
271 int pointed_to_offset
;
273 /* Values are stored in a chain, so that they can be deleted easily
274 over calls to the inferior. Values assigned to internal
275 variables, put into the value history or exposed to Python are
276 taken off this list. */
279 /* Register number if the value is from a register. */
282 /* If zero, contents of this value are in the contents field. If
283 nonzero, contents are in inferior. If the lval field is lval_memory,
284 the contents are in inferior memory at location.address plus offset.
285 The lval field may also be lval_register.
287 WARNING: This field is used by the code which handles watchpoints
288 (see breakpoint.c) to decide whether a particular value can be
289 watched by hardware watchpoints. If the lazy flag is set for
290 some member of a value chain, it is assumed that this member of
291 the chain doesn't need to be watched as part of watching the
292 value itself. This is how GDB avoids watching the entire struct
293 or array when the user wants to watch a single struct member or
294 array element. If you ever change the way lazy flag is set and
295 reset, be sure to consider this use as well! */
298 /* If nonzero, this is the value of a variable which does not
299 actually exist in the program. */
302 /* If value is a variable, is it initialized or not. */
305 /* If value is from the stack. If this is set, read_stack will be
306 used instead of read_memory to enable extra caching. */
309 /* Actual contents of the value. Target byte-order. NULL or not
310 valid if lazy is nonzero. */
313 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
314 rather than available, since the common and default case is for a
315 value to be available. This is filled in at value read time. */
316 VEC(range_s
) *unavailable
;
318 /* The number of references to this value. When a value is created,
319 the value chain holds a reference, so REFERENCE_COUNT is 1. If
320 release_value is called, this value is removed from the chain but
321 the caller of release_value now has a reference to this value.
322 The caller must arrange for a call to value_free later. */
327 value_bytes_available (const struct value
*value
, int offset
, int length
)
329 gdb_assert (!value
->lazy
);
331 return !ranges_contain (value
->unavailable
, offset
, length
);
335 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
340 /* Insert the range sorted. If there's overlap or the new range
341 would be contiguous with an existing range, merge. */
343 newr
.offset
= offset
;
344 newr
.length
= length
;
346 /* Do a binary search for the position the given range would be
347 inserted if we only considered the starting OFFSET of ranges.
348 Call that position I. Since we also have LENGTH to care for
349 (this is a range afterall), we need to check if the _previous_
350 range overlaps the I range. E.g., calling R the new range:
352 #1 - overlaps with previous
356 |---| |---| |------| ... |--|
361 In the case #1 above, the binary search would return `I=1',
362 meaning, this OFFSET should be inserted at position 1, and the
363 current position 1 should be pushed further (and become 2). But,
364 note that `0' overlaps with R, so we want to merge them.
366 A similar consideration needs to be taken if the new range would
367 be contiguous with the previous range:
369 #2 - contiguous with previous
373 |--| |---| |------| ... |--|
378 If there's no overlap with the previous range, as in:
380 #3 - not overlapping and not contiguous
384 |--| |---| |------| ... |--|
391 #4 - R is the range with lowest offset
395 |--| |---| |------| ... |--|
400 ... we just push the new range to I.
402 All the 4 cases above need to consider that the new range may
403 also overlap several of the ranges that follow, or that R may be
404 contiguous with the following range, and merge. E.g.,
406 #5 - overlapping following ranges
409 |------------------------|
410 |--| |---| |------| ... |--|
419 |--| |---| |------| ... |--|
426 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
429 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- i
);
431 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
434 ULONGEST l
= min (bef
->offset
, offset
);
435 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
441 else if (offset
== bef
->offset
+ bef
->length
)
444 bef
->length
+= length
;
450 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
456 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
459 /* Check whether the ranges following the one we've just added or
460 touched can be folded in (#5 above). */
461 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
468 /* Get the range we just touched. */
469 t
= VEC_index (range_s
, value
->unavailable
, i
);
473 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
474 if (r
->offset
<= t
->offset
+ t
->length
)
478 l
= min (t
->offset
, r
->offset
);
479 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
488 /* If we couldn't merge this one, we won't be able to
489 merge following ones either, since the ranges are
490 always sorted by OFFSET. */
495 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
499 /* Find the first range in RANGES that overlaps the range defined by
500 OFFSET and LENGTH, starting at element POS in the RANGES vector,
501 Returns the index into RANGES where such overlapping range was
502 found, or -1 if none was found. */
505 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
506 int offset
, int length
)
511 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
512 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
519 value_available_contents_eq (const struct value
*val1
, int offset1
,
520 const struct value
*val2
, int offset2
,
523 int org_len
= length
;
524 int org_offset1
= offset1
;
525 int org_offset2
= offset2
;
526 int idx1
= 0, idx2
= 0;
529 /* This routine is used by printing routines, where we should
530 already have read the value. Note that we only know whether a
531 value chunk is available if we've tried to read it. */
532 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
534 /* The offset from either ORG_OFFSET1 or ORG_OFFSET2 where the
535 available contents we haven't compared yet start. */
544 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
546 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
549 /* The usual case is for both values to be completely available. */
550 if (idx1
== -1 && idx2
== -1)
551 return (memcmp (val1
->contents
+ org_offset1
+ prev_avail
,
552 val2
->contents
+ org_offset2
+ prev_avail
,
553 org_len
- prev_avail
) == 0);
554 /* The contents only match equal if the available set matches as
556 else if (idx1
== -1 || idx2
== -1)
559 gdb_assert (idx1
!= -1 && idx2
!= -1);
561 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
562 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
564 /* Get the unavailable windows intersected by the incoming
565 ranges. The first and last ranges that overlap the argument
566 range may be wider than said incoming arguments ranges. */
567 l1
= max (offset1
, r1
->offset
);
568 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
570 l2
= max (offset2
, r2
->offset
);
571 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
573 /* Make them relative to the respective start offsets, so we can
574 compare them for equality. */
581 /* Different availability, no match. */
582 if (l1
!= l2
|| h1
!= h2
)
585 /* Compare the _available_ contents. */
586 if (memcmp (val1
->contents
+ org_offset1
+ prev_avail
,
587 val2
->contents
+ org_offset2
+ prev_avail
,
588 l2
- prev_avail
) != 0)
600 /* Prototypes for local functions. */
602 static void show_values (char *, int);
604 static void show_convenience (char *, int);
607 /* The value-history records all the values printed
608 by print commands during this session. Each chunk
609 records 60 consecutive values. The first chunk on
610 the chain records the most recent values.
611 The total number of values is in value_history_count. */
613 #define VALUE_HISTORY_CHUNK 60
615 struct value_history_chunk
617 struct value_history_chunk
*next
;
618 struct value
*values
[VALUE_HISTORY_CHUNK
];
621 /* Chain of chunks now in use. */
623 static struct value_history_chunk
*value_history_chain
;
625 static int value_history_count
; /* Abs number of last entry stored. */
628 /* List of all value objects currently allocated
629 (except for those released by calls to release_value)
630 This is so they can be freed after each command. */
632 static struct value
*all_values
;
634 /* Allocate a lazy value for type TYPE. Its actual content is
635 "lazily" allocated too: the content field of the return value is
636 NULL; it will be allocated when it is fetched from the target. */
639 allocate_value_lazy (struct type
*type
)
643 /* Call check_typedef on our type to make sure that, if TYPE
644 is a TYPE_CODE_TYPEDEF, its length is set to the length
645 of the target type instead of zero. However, we do not
646 replace the typedef type by the target type, because we want
647 to keep the typedef in order to be able to set the VAL's type
648 description correctly. */
649 check_typedef (type
);
651 val
= (struct value
*) xzalloc (sizeof (struct value
));
652 val
->contents
= NULL
;
653 val
->next
= all_values
;
656 val
->enclosing_type
= type
;
657 VALUE_LVAL (val
) = not_lval
;
658 val
->location
.address
= 0;
659 VALUE_FRAME_ID (val
) = null_frame_id
;
663 VALUE_REGNUM (val
) = -1;
665 val
->optimized_out
= 0;
666 val
->embedded_offset
= 0;
667 val
->pointed_to_offset
= 0;
669 val
->initialized
= 1; /* Default to initialized. */
671 /* Values start out on the all_values chain. */
672 val
->reference_count
= 1;
677 /* Allocate the contents of VAL if it has not been allocated yet. */
680 allocate_value_contents (struct value
*val
)
683 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
686 /* Allocate a value and its contents for type TYPE. */
689 allocate_value (struct type
*type
)
691 struct value
*val
= allocate_value_lazy (type
);
693 allocate_value_contents (val
);
698 /* Allocate a value that has the correct length
699 for COUNT repetitions of type TYPE. */
702 allocate_repeat_value (struct type
*type
, int count
)
704 int low_bound
= current_language
->string_lower_bound
; /* ??? */
705 /* FIXME-type-allocation: need a way to free this type when we are
707 struct type
*array_type
708 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
710 return allocate_value (array_type
);
714 allocate_computed_value (struct type
*type
,
715 struct lval_funcs
*funcs
,
718 struct value
*v
= allocate_value_lazy (type
);
720 VALUE_LVAL (v
) = lval_computed
;
721 v
->location
.computed
.funcs
= funcs
;
722 v
->location
.computed
.closure
= closure
;
727 /* Accessor methods. */
730 value_next (struct value
*value
)
736 value_type (const struct value
*value
)
741 deprecated_set_value_type (struct value
*value
, struct type
*type
)
747 value_offset (const struct value
*value
)
749 return value
->offset
;
752 set_value_offset (struct value
*value
, int offset
)
754 value
->offset
= offset
;
758 value_bitpos (const struct value
*value
)
760 return value
->bitpos
;
763 set_value_bitpos (struct value
*value
, int bit
)
769 value_bitsize (const struct value
*value
)
771 return value
->bitsize
;
774 set_value_bitsize (struct value
*value
, int bit
)
776 value
->bitsize
= bit
;
780 value_parent (struct value
*value
)
782 return value
->parent
;
786 value_contents_raw (struct value
*value
)
788 allocate_value_contents (value
);
789 return value
->contents
+ value
->embedded_offset
;
793 value_contents_all_raw (struct value
*value
)
795 allocate_value_contents (value
);
796 return value
->contents
;
800 value_enclosing_type (struct value
*value
)
802 return value
->enclosing_type
;
806 require_not_optimized_out (const struct value
*value
)
808 if (value
->optimized_out
)
809 error (_("value has been optimized out"));
813 require_available (const struct value
*value
)
815 if (!VEC_empty (range_s
, value
->unavailable
))
816 error (_("value is not available"));
820 value_contents_for_printing (struct value
*value
)
823 value_fetch_lazy (value
);
824 return value
->contents
;
828 value_contents_for_printing_const (const struct value
*value
)
830 gdb_assert (!value
->lazy
);
831 return value
->contents
;
835 value_contents_all (struct value
*value
)
837 const gdb_byte
*result
= value_contents_for_printing (value
);
838 require_not_optimized_out (value
);
839 require_available (value
);
844 value_lazy (struct value
*value
)
850 set_value_lazy (struct value
*value
, int val
)
856 value_stack (struct value
*value
)
862 set_value_stack (struct value
*value
, int val
)
868 value_contents (struct value
*value
)
870 const gdb_byte
*result
= value_contents_writeable (value
);
871 require_not_optimized_out (value
);
872 require_available (value
);
877 value_contents_writeable (struct value
*value
)
880 value_fetch_lazy (value
);
881 return value_contents_raw (value
);
884 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
885 this function is different from value_equal; in C the operator ==
886 can return 0 even if the two values being compared are equal. */
889 value_contents_equal (struct value
*val1
, struct value
*val2
)
895 type1
= check_typedef (value_type (val1
));
896 type2
= check_typedef (value_type (val2
));
897 len
= TYPE_LENGTH (type1
);
898 if (len
!= TYPE_LENGTH (type2
))
901 return (memcmp (value_contents (val1
), value_contents (val2
), len
) == 0);
905 value_optimized_out (struct value
*value
)
907 return value
->optimized_out
;
911 set_value_optimized_out (struct value
*value
, int val
)
913 value
->optimized_out
= val
;
917 value_entirely_optimized_out (const struct value
*value
)
919 if (!value
->optimized_out
)
921 if (value
->lval
!= lval_computed
922 || !value
->location
.computed
.funcs
->check_any_valid
)
924 return !value
->location
.computed
.funcs
->check_any_valid (value
);
928 value_bits_valid (const struct value
*value
, int offset
, int length
)
930 if (value
== NULL
|| !value
->optimized_out
)
932 if (value
->lval
!= lval_computed
933 || !value
->location
.computed
.funcs
->check_validity
)
935 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
940 value_bits_synthetic_pointer (const struct value
*value
,
941 int offset
, int length
)
943 if (value
== NULL
|| value
->lval
!= lval_computed
944 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
946 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
952 value_embedded_offset (struct value
*value
)
954 return value
->embedded_offset
;
958 set_value_embedded_offset (struct value
*value
, int val
)
960 value
->embedded_offset
= val
;
964 value_pointed_to_offset (struct value
*value
)
966 return value
->pointed_to_offset
;
970 set_value_pointed_to_offset (struct value
*value
, int val
)
972 value
->pointed_to_offset
= val
;
976 value_computed_funcs (struct value
*v
)
978 gdb_assert (VALUE_LVAL (v
) == lval_computed
);
980 return v
->location
.computed
.funcs
;
984 value_computed_closure (const struct value
*v
)
986 gdb_assert (v
->lval
== lval_computed
);
988 return v
->location
.computed
.closure
;
992 deprecated_value_lval_hack (struct value
*value
)
998 value_address (const struct value
*value
)
1000 if (value
->lval
== lval_internalvar
1001 || value
->lval
== lval_internalvar_component
)
1003 return value
->location
.address
+ value
->offset
;
1007 value_raw_address (struct value
*value
)
1009 if (value
->lval
== lval_internalvar
1010 || value
->lval
== lval_internalvar_component
)
1012 return value
->location
.address
;
1016 set_value_address (struct value
*value
, CORE_ADDR addr
)
1018 gdb_assert (value
->lval
!= lval_internalvar
1019 && value
->lval
!= lval_internalvar_component
);
1020 value
->location
.address
= addr
;
1023 struct internalvar
**
1024 deprecated_value_internalvar_hack (struct value
*value
)
1026 return &value
->location
.internalvar
;
1030 deprecated_value_frame_id_hack (struct value
*value
)
1032 return &value
->frame_id
;
1036 deprecated_value_regnum_hack (struct value
*value
)
1038 return &value
->regnum
;
1042 deprecated_value_modifiable (struct value
*value
)
1044 return value
->modifiable
;
1047 deprecated_set_value_modifiable (struct value
*value
, int modifiable
)
1049 value
->modifiable
= modifiable
;
1052 /* Return a mark in the value chain. All values allocated after the
1053 mark is obtained (except for those released) are subject to being freed
1054 if a subsequent value_free_to_mark is passed the mark. */
1061 /* Take a reference to VAL. VAL will not be deallocated until all
1062 references are released. */
1065 value_incref (struct value
*val
)
1067 val
->reference_count
++;
1070 /* Release a reference to VAL, which was acquired with value_incref.
1071 This function is also called to deallocate values from the value
1075 value_free (struct value
*val
)
1079 gdb_assert (val
->reference_count
> 0);
1080 val
->reference_count
--;
1081 if (val
->reference_count
> 0)
1084 /* If there's an associated parent value, drop our reference to
1086 if (val
->parent
!= NULL
)
1087 value_free (val
->parent
);
1089 if (VALUE_LVAL (val
) == lval_computed
)
1091 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1093 if (funcs
->free_closure
)
1094 funcs
->free_closure (val
);
1097 xfree (val
->contents
);
1098 VEC_free (range_s
, val
->unavailable
);
1103 /* Free all values allocated since MARK was obtained by value_mark
1104 (except for those released). */
1106 value_free_to_mark (struct value
*mark
)
1111 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1119 /* Free all the values that have been allocated (except for those released).
1120 Call after each command, successful or not.
1121 In practice this is called before each command, which is sufficient. */
1124 free_all_values (void)
1129 for (val
= all_values
; val
; val
= next
)
1138 /* Frees all the elements in a chain of values. */
1141 free_value_chain (struct value
*v
)
1147 next
= value_next (v
);
1152 /* Remove VAL from the chain all_values
1153 so it will not be freed automatically. */
1156 release_value (struct value
*val
)
1160 if (all_values
== val
)
1162 all_values
= val
->next
;
1167 for (v
= all_values
; v
; v
= v
->next
)
1171 v
->next
= val
->next
;
1178 /* Release all values up to mark */
1180 value_release_to_mark (struct value
*mark
)
1185 for (val
= next
= all_values
; next
; next
= next
->next
)
1186 if (next
->next
== mark
)
1188 all_values
= next
->next
;
1196 /* Return a copy of the value ARG.
1197 It contains the same contents, for same memory address,
1198 but it's a different block of storage. */
1201 value_copy (struct value
*arg
)
1203 struct type
*encl_type
= value_enclosing_type (arg
);
1206 if (value_lazy (arg
))
1207 val
= allocate_value_lazy (encl_type
);
1209 val
= allocate_value (encl_type
);
1210 val
->type
= arg
->type
;
1211 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1212 val
->location
= arg
->location
;
1213 val
->offset
= arg
->offset
;
1214 val
->bitpos
= arg
->bitpos
;
1215 val
->bitsize
= arg
->bitsize
;
1216 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1217 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1218 val
->lazy
= arg
->lazy
;
1219 val
->optimized_out
= arg
->optimized_out
;
1220 val
->embedded_offset
= value_embedded_offset (arg
);
1221 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1222 val
->modifiable
= arg
->modifiable
;
1223 if (!value_lazy (val
))
1225 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1226 TYPE_LENGTH (value_enclosing_type (arg
)));
1229 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1230 val
->parent
= arg
->parent
;
1232 value_incref (val
->parent
);
1233 if (VALUE_LVAL (val
) == lval_computed
)
1235 struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1237 if (funcs
->copy_closure
)
1238 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1243 /* Return a version of ARG that is non-lvalue. */
1246 value_non_lval (struct value
*arg
)
1248 if (VALUE_LVAL (arg
) != not_lval
)
1250 struct type
*enc_type
= value_enclosing_type (arg
);
1251 struct value
*val
= allocate_value (enc_type
);
1253 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1254 TYPE_LENGTH (enc_type
));
1255 val
->type
= arg
->type
;
1256 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1257 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1264 set_value_component_location (struct value
*component
,
1265 const struct value
*whole
)
1267 if (whole
->lval
== lval_internalvar
)
1268 VALUE_LVAL (component
) = lval_internalvar_component
;
1270 VALUE_LVAL (component
) = whole
->lval
;
1272 component
->location
= whole
->location
;
1273 if (whole
->lval
== lval_computed
)
1275 struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1277 if (funcs
->copy_closure
)
1278 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1283 /* Access to the value history. */
1285 /* Record a new value in the value history.
1286 Returns the absolute history index of the entry.
1287 Result of -1 indicates the value was not saved; otherwise it is the
1288 value history index of this new item. */
1291 record_latest_value (struct value
*val
)
1295 /* We don't want this value to have anything to do with the inferior anymore.
1296 In particular, "set $1 = 50" should not affect the variable from which
1297 the value was taken, and fast watchpoints should be able to assume that
1298 a value on the value history never changes. */
1299 if (value_lazy (val
))
1300 value_fetch_lazy (val
);
1301 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1302 from. This is a bit dubious, because then *&$1 does not just return $1
1303 but the current contents of that location. c'est la vie... */
1304 val
->modifiable
= 0;
1305 release_value (val
);
1307 /* Here we treat value_history_count as origin-zero
1308 and applying to the value being stored now. */
1310 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1313 struct value_history_chunk
*new
1314 = (struct value_history_chunk
*)
1316 xmalloc (sizeof (struct value_history_chunk
));
1317 memset (new->values
, 0, sizeof new->values
);
1318 new->next
= value_history_chain
;
1319 value_history_chain
= new;
1322 value_history_chain
->values
[i
] = val
;
1324 /* Now we regard value_history_count as origin-one
1325 and applying to the value just stored. */
1327 return ++value_history_count
;
1330 /* Return a copy of the value in the history with sequence number NUM. */
1333 access_value_history (int num
)
1335 struct value_history_chunk
*chunk
;
1340 absnum
+= value_history_count
;
1345 error (_("The history is empty."));
1347 error (_("There is only one value in the history."));
1349 error (_("History does not go back to $$%d."), -num
);
1351 if (absnum
> value_history_count
)
1352 error (_("History has not yet reached $%d."), absnum
);
1356 /* Now absnum is always absolute and origin zero. */
1358 chunk
= value_history_chain
;
1359 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1360 - absnum
/ VALUE_HISTORY_CHUNK
;
1362 chunk
= chunk
->next
;
1364 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1368 show_values (char *num_exp
, int from_tty
)
1376 /* "show values +" should print from the stored position.
1377 "show values <exp>" should print around value number <exp>. */
1378 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1379 num
= parse_and_eval_long (num_exp
) - 5;
1383 /* "show values" means print the last 10 values. */
1384 num
= value_history_count
- 9;
1390 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1392 struct value_print_options opts
;
1394 val
= access_value_history (i
);
1395 printf_filtered (("$%d = "), i
);
1396 get_user_print_options (&opts
);
1397 value_print (val
, gdb_stdout
, &opts
);
1398 printf_filtered (("\n"));
1401 /* The next "show values +" should start after what we just printed. */
1404 /* Hitting just return after this command should do the same thing as
1405 "show values +". If num_exp is null, this is unnecessary, since
1406 "show values +" is not useful after "show values". */
1407 if (from_tty
&& num_exp
)
1414 /* Internal variables. These are variables within the debugger
1415 that hold values assigned by debugger commands.
1416 The user refers to them with a '$' prefix
1417 that does not appear in the variable names stored internally. */
1421 struct internalvar
*next
;
1424 /* We support various different kinds of content of an internal variable.
1425 enum internalvar_kind specifies the kind, and union internalvar_data
1426 provides the data associated with this particular kind. */
1428 enum internalvar_kind
1430 /* The internal variable is empty. */
1433 /* The value of the internal variable is provided directly as
1434 a GDB value object. */
1437 /* A fresh value is computed via a call-back routine on every
1438 access to the internal variable. */
1439 INTERNALVAR_MAKE_VALUE
,
1441 /* The internal variable holds a GDB internal convenience function. */
1442 INTERNALVAR_FUNCTION
,
1444 /* The variable holds an integer value. */
1445 INTERNALVAR_INTEGER
,
1447 /* The variable holds a pointer value. */
1448 INTERNALVAR_POINTER
,
1450 /* The variable holds a GDB-provided string. */
1455 union internalvar_data
1457 /* A value object used with INTERNALVAR_VALUE. */
1458 struct value
*value
;
1460 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1461 internalvar_make_value make_value
;
1463 /* The internal function used with INTERNALVAR_FUNCTION. */
1466 struct internal_function
*function
;
1467 /* True if this is the canonical name for the function. */
1471 /* An integer value used with INTERNALVAR_INTEGER. */
1474 /* If type is non-NULL, it will be used as the type to generate
1475 a value for this internal variable. If type is NULL, a default
1476 integer type for the architecture is used. */
1481 /* A pointer value used with INTERNALVAR_POINTER. */
1488 /* A string value used with INTERNALVAR_STRING. */
1493 static struct internalvar
*internalvars
;
1495 /* If the variable does not already exist create it and give it the
1496 value given. If no value is given then the default is zero. */
1498 init_if_undefined_command (char* args
, int from_tty
)
1500 struct internalvar
* intvar
;
1502 /* Parse the expression - this is taken from set_command(). */
1503 struct expression
*expr
= parse_expression (args
);
1504 register struct cleanup
*old_chain
=
1505 make_cleanup (free_current_contents
, &expr
);
1507 /* Validate the expression.
1508 Was the expression an assignment?
1509 Or even an expression at all? */
1510 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1511 error (_("Init-if-undefined requires an assignment expression."));
1513 /* Extract the variable from the parsed expression.
1514 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1515 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1516 error (_("The first parameter to init-if-undefined "
1517 "should be a GDB variable."));
1518 intvar
= expr
->elts
[2].internalvar
;
1520 /* Only evaluate the expression if the lvalue is void.
1521 This may still fail if the expresssion is invalid. */
1522 if (intvar
->kind
== INTERNALVAR_VOID
)
1523 evaluate_expression (expr
);
1525 do_cleanups (old_chain
);
1529 /* Look up an internal variable with name NAME. NAME should not
1530 normally include a dollar sign.
1532 If the specified internal variable does not exist,
1533 the return value is NULL. */
1535 struct internalvar
*
1536 lookup_only_internalvar (const char *name
)
1538 struct internalvar
*var
;
1540 for (var
= internalvars
; var
; var
= var
->next
)
1541 if (strcmp (var
->name
, name
) == 0)
1548 /* Create an internal variable with name NAME and with a void value.
1549 NAME should not normally include a dollar sign. */
1551 struct internalvar
*
1552 create_internalvar (const char *name
)
1554 struct internalvar
*var
;
1556 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1557 var
->name
= concat (name
, (char *)NULL
);
1558 var
->kind
= INTERNALVAR_VOID
;
1559 var
->next
= internalvars
;
1564 /* Create an internal variable with name NAME and register FUN as the
1565 function that value_of_internalvar uses to create a value whenever
1566 this variable is referenced. NAME should not normally include a
1569 struct internalvar
*
1570 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
)
1572 struct internalvar
*var
= create_internalvar (name
);
1574 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1575 var
->u
.make_value
= fun
;
1579 /* Look up an internal variable with name NAME. NAME should not
1580 normally include a dollar sign.
1582 If the specified internal variable does not exist,
1583 one is created, with a void value. */
1585 struct internalvar
*
1586 lookup_internalvar (const char *name
)
1588 struct internalvar
*var
;
1590 var
= lookup_only_internalvar (name
);
1594 return create_internalvar (name
);
1597 /* Return current value of internal variable VAR. For variables that
1598 are not inherently typed, use a value type appropriate for GDBARCH. */
1601 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1604 struct trace_state_variable
*tsv
;
1606 /* If there is a trace state variable of the same name, assume that
1607 is what we really want to see. */
1608 tsv
= find_trace_state_variable (var
->name
);
1611 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1613 if (tsv
->value_known
)
1614 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1617 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1623 case INTERNALVAR_VOID
:
1624 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1627 case INTERNALVAR_FUNCTION
:
1628 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1631 case INTERNALVAR_INTEGER
:
1632 if (!var
->u
.integer
.type
)
1633 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1634 var
->u
.integer
.val
);
1636 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1639 case INTERNALVAR_POINTER
:
1640 val
= value_from_pointer (var
->u
.pointer
.type
, var
->u
.pointer
.val
);
1643 case INTERNALVAR_STRING
:
1644 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1645 builtin_type (gdbarch
)->builtin_char
);
1648 case INTERNALVAR_VALUE
:
1649 val
= value_copy (var
->u
.value
);
1650 if (value_lazy (val
))
1651 value_fetch_lazy (val
);
1654 case INTERNALVAR_MAKE_VALUE
:
1655 val
= (*var
->u
.make_value
) (gdbarch
, var
);
1659 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1662 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1663 on this value go back to affect the original internal variable.
1665 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1666 no underlying modifyable state in the internal variable.
1668 Likewise, if the variable's value is a computed lvalue, we want
1669 references to it to produce another computed lvalue, where
1670 references and assignments actually operate through the
1671 computed value's functions.
1673 This means that internal variables with computed values
1674 behave a little differently from other internal variables:
1675 assignments to them don't just replace the previous value
1676 altogether. At the moment, this seems like the behavior we
1679 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1680 && val
->lval
!= lval_computed
)
1682 VALUE_LVAL (val
) = lval_internalvar
;
1683 VALUE_INTERNALVAR (val
) = var
;
1690 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1694 case INTERNALVAR_INTEGER
:
1695 *result
= var
->u
.integer
.val
;
1704 get_internalvar_function (struct internalvar
*var
,
1705 struct internal_function
**result
)
1709 case INTERNALVAR_FUNCTION
:
1710 *result
= var
->u
.fn
.function
;
1719 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1720 int bitsize
, struct value
*newval
)
1726 case INTERNALVAR_VALUE
:
1727 addr
= value_contents_writeable (var
->u
.value
);
1730 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1731 value_as_long (newval
), bitpos
, bitsize
);
1733 memcpy (addr
+ offset
, value_contents (newval
),
1734 TYPE_LENGTH (value_type (newval
)));
1738 /* We can never get a component of any other kind. */
1739 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1744 set_internalvar (struct internalvar
*var
, struct value
*val
)
1746 enum internalvar_kind new_kind
;
1747 union internalvar_data new_data
= { 0 };
1749 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1750 error (_("Cannot overwrite convenience function %s"), var
->name
);
1752 /* Prepare new contents. */
1753 switch (TYPE_CODE (check_typedef (value_type (val
))))
1755 case TYPE_CODE_VOID
:
1756 new_kind
= INTERNALVAR_VOID
;
1759 case TYPE_CODE_INTERNAL_FUNCTION
:
1760 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1761 new_kind
= INTERNALVAR_FUNCTION
;
1762 get_internalvar_function (VALUE_INTERNALVAR (val
),
1763 &new_data
.fn
.function
);
1764 /* Copies created here are never canonical. */
1768 new_kind
= INTERNALVAR_INTEGER
;
1769 new_data
.integer
.type
= value_type (val
);
1770 new_data
.integer
.val
= value_as_long (val
);
1774 new_kind
= INTERNALVAR_POINTER
;
1775 new_data
.pointer
.type
= value_type (val
);
1776 new_data
.pointer
.val
= value_as_address (val
);
1780 new_kind
= INTERNALVAR_VALUE
;
1781 new_data
.value
= value_copy (val
);
1782 new_data
.value
->modifiable
= 1;
1784 /* Force the value to be fetched from the target now, to avoid problems
1785 later when this internalvar is referenced and the target is gone or
1787 if (value_lazy (new_data
.value
))
1788 value_fetch_lazy (new_data
.value
);
1790 /* Release the value from the value chain to prevent it from being
1791 deleted by free_all_values. From here on this function should not
1792 call error () until new_data is installed into the var->u to avoid
1794 release_value (new_data
.value
);
1798 /* Clean up old contents. */
1799 clear_internalvar (var
);
1802 var
->kind
= new_kind
;
1804 /* End code which must not call error(). */
1808 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
1810 /* Clean up old contents. */
1811 clear_internalvar (var
);
1813 var
->kind
= INTERNALVAR_INTEGER
;
1814 var
->u
.integer
.type
= NULL
;
1815 var
->u
.integer
.val
= l
;
1819 set_internalvar_string (struct internalvar
*var
, const char *string
)
1821 /* Clean up old contents. */
1822 clear_internalvar (var
);
1824 var
->kind
= INTERNALVAR_STRING
;
1825 var
->u
.string
= xstrdup (string
);
1829 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
1831 /* Clean up old contents. */
1832 clear_internalvar (var
);
1834 var
->kind
= INTERNALVAR_FUNCTION
;
1835 var
->u
.fn
.function
= f
;
1836 var
->u
.fn
.canonical
= 1;
1837 /* Variables installed here are always the canonical version. */
1841 clear_internalvar (struct internalvar
*var
)
1843 /* Clean up old contents. */
1846 case INTERNALVAR_VALUE
:
1847 value_free (var
->u
.value
);
1850 case INTERNALVAR_STRING
:
1851 xfree (var
->u
.string
);
1858 /* Reset to void kind. */
1859 var
->kind
= INTERNALVAR_VOID
;
1863 internalvar_name (struct internalvar
*var
)
1868 static struct internal_function
*
1869 create_internal_function (const char *name
,
1870 internal_function_fn handler
, void *cookie
)
1872 struct internal_function
*ifn
= XNEW (struct internal_function
);
1874 ifn
->name
= xstrdup (name
);
1875 ifn
->handler
= handler
;
1876 ifn
->cookie
= cookie
;
1881 value_internal_function_name (struct value
*val
)
1883 struct internal_function
*ifn
;
1886 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1887 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
1888 gdb_assert (result
);
1894 call_internal_function (struct gdbarch
*gdbarch
,
1895 const struct language_defn
*language
,
1896 struct value
*func
, int argc
, struct value
**argv
)
1898 struct internal_function
*ifn
;
1901 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
1902 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
1903 gdb_assert (result
);
1905 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
1908 /* The 'function' command. This does nothing -- it is just a
1909 placeholder to let "help function NAME" work. This is also used as
1910 the implementation of the sub-command that is created when
1911 registering an internal function. */
1913 function_command (char *command
, int from_tty
)
1918 /* Clean up if an internal function's command is destroyed. */
1920 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
1926 /* Add a new internal function. NAME is the name of the function; DOC
1927 is a documentation string describing the function. HANDLER is
1928 called when the function is invoked. COOKIE is an arbitrary
1929 pointer which is passed to HANDLER and is intended for "user
1932 add_internal_function (const char *name
, const char *doc
,
1933 internal_function_fn handler
, void *cookie
)
1935 struct cmd_list_element
*cmd
;
1936 struct internal_function
*ifn
;
1937 struct internalvar
*var
= lookup_internalvar (name
);
1939 ifn
= create_internal_function (name
, handler
, cookie
);
1940 set_internalvar_function (var
, ifn
);
1942 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
1944 cmd
->destroyer
= function_destroyer
;
1947 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
1948 prevent cycles / duplicates. */
1951 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
1952 htab_t copied_types
)
1954 if (TYPE_OBJFILE (value
->type
) == objfile
)
1955 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
1957 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
1958 value
->enclosing_type
= copy_type_recursive (objfile
,
1959 value
->enclosing_type
,
1963 /* Likewise for internal variable VAR. */
1966 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
1967 htab_t copied_types
)
1971 case INTERNALVAR_INTEGER
:
1972 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
1974 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
1977 case INTERNALVAR_POINTER
:
1978 if (TYPE_OBJFILE (var
->u
.pointer
.type
) == objfile
)
1980 = copy_type_recursive (objfile
, var
->u
.pointer
.type
, copied_types
);
1983 case INTERNALVAR_VALUE
:
1984 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
1989 /* Update the internal variables and value history when OBJFILE is
1990 discarded; we must copy the types out of the objfile. New global types
1991 will be created for every convenience variable which currently points to
1992 this objfile's types, and the convenience variables will be adjusted to
1993 use the new global types. */
1996 preserve_values (struct objfile
*objfile
)
1998 htab_t copied_types
;
1999 struct value_history_chunk
*cur
;
2000 struct internalvar
*var
;
2003 /* Create the hash table. We allocate on the objfile's obstack, since
2004 it is soon to be deleted. */
2005 copied_types
= create_copied_types_hash (objfile
);
2007 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2008 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2010 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2012 for (var
= internalvars
; var
; var
= var
->next
)
2013 preserve_one_internalvar (var
, objfile
, copied_types
);
2015 preserve_python_values (objfile
, copied_types
);
2017 htab_delete (copied_types
);
2021 show_convenience (char *ignore
, int from_tty
)
2023 struct gdbarch
*gdbarch
= get_current_arch ();
2024 struct internalvar
*var
;
2026 struct value_print_options opts
;
2028 get_user_print_options (&opts
);
2029 for (var
= internalvars
; var
; var
= var
->next
)
2035 printf_filtered (("$%s = "), var
->name
);
2036 value_print (value_of_internalvar (gdbarch
, var
), gdb_stdout
,
2038 printf_filtered (("\n"));
2041 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2042 "Convenience variables have "
2043 "names starting with \"$\";\n"
2044 "use \"set\" as in \"set "
2045 "$foo = 5\" to define them.\n"));
2048 /* Extract a value as a C number (either long or double).
2049 Knows how to convert fixed values to double, or
2050 floating values to long.
2051 Does not deallocate the value. */
2054 value_as_long (struct value
*val
)
2056 /* This coerces arrays and functions, which is necessary (e.g.
2057 in disassemble_command). It also dereferences references, which
2058 I suspect is the most logical thing to do. */
2059 val
= coerce_array (val
);
2060 return unpack_long (value_type (val
), value_contents (val
));
2064 value_as_double (struct value
*val
)
2069 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2071 error (_("Invalid floating value found in program."));
2075 /* Extract a value as a C pointer. Does not deallocate the value.
2076 Note that val's type may not actually be a pointer; value_as_long
2077 handles all the cases. */
2079 value_as_address (struct value
*val
)
2081 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2083 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2084 whether we want this to be true eventually. */
2086 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2087 non-address (e.g. argument to "signal", "info break", etc.), or
2088 for pointers to char, in which the low bits *are* significant. */
2089 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2092 /* There are several targets (IA-64, PowerPC, and others) which
2093 don't represent pointers to functions as simply the address of
2094 the function's entry point. For example, on the IA-64, a
2095 function pointer points to a two-word descriptor, generated by
2096 the linker, which contains the function's entry point, and the
2097 value the IA-64 "global pointer" register should have --- to
2098 support position-independent code. The linker generates
2099 descriptors only for those functions whose addresses are taken.
2101 On such targets, it's difficult for GDB to convert an arbitrary
2102 function address into a function pointer; it has to either find
2103 an existing descriptor for that function, or call malloc and
2104 build its own. On some targets, it is impossible for GDB to
2105 build a descriptor at all: the descriptor must contain a jump
2106 instruction; data memory cannot be executed; and code memory
2109 Upon entry to this function, if VAL is a value of type `function'
2110 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2111 value_address (val) is the address of the function. This is what
2112 you'll get if you evaluate an expression like `main'. The call
2113 to COERCE_ARRAY below actually does all the usual unary
2114 conversions, which includes converting values of type `function'
2115 to `pointer to function'. This is the challenging conversion
2116 discussed above. Then, `unpack_long' will convert that pointer
2117 back into an address.
2119 So, suppose the user types `disassemble foo' on an architecture
2120 with a strange function pointer representation, on which GDB
2121 cannot build its own descriptors, and suppose further that `foo'
2122 has no linker-built descriptor. The address->pointer conversion
2123 will signal an error and prevent the command from running, even
2124 though the next step would have been to convert the pointer
2125 directly back into the same address.
2127 The following shortcut avoids this whole mess. If VAL is a
2128 function, just return its address directly. */
2129 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2130 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2131 return value_address (val
);
2133 val
= coerce_array (val
);
2135 /* Some architectures (e.g. Harvard), map instruction and data
2136 addresses onto a single large unified address space. For
2137 instance: An architecture may consider a large integer in the
2138 range 0x10000000 .. 0x1000ffff to already represent a data
2139 addresses (hence not need a pointer to address conversion) while
2140 a small integer would still need to be converted integer to
2141 pointer to address. Just assume such architectures handle all
2142 integer conversions in a single function. */
2146 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2147 must admonish GDB hackers to make sure its behavior matches the
2148 compiler's, whenever possible.
2150 In general, I think GDB should evaluate expressions the same way
2151 the compiler does. When the user copies an expression out of
2152 their source code and hands it to a `print' command, they should
2153 get the same value the compiler would have computed. Any
2154 deviation from this rule can cause major confusion and annoyance,
2155 and needs to be justified carefully. In other words, GDB doesn't
2156 really have the freedom to do these conversions in clever and
2159 AndrewC pointed out that users aren't complaining about how GDB
2160 casts integers to pointers; they are complaining that they can't
2161 take an address from a disassembly listing and give it to `x/i'.
2162 This is certainly important.
2164 Adding an architecture method like integer_to_address() certainly
2165 makes it possible for GDB to "get it right" in all circumstances
2166 --- the target has complete control over how things get done, so
2167 people can Do The Right Thing for their target without breaking
2168 anyone else. The standard doesn't specify how integers get
2169 converted to pointers; usually, the ABI doesn't either, but
2170 ABI-specific code is a more reasonable place to handle it. */
2172 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2173 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2174 && gdbarch_integer_to_address_p (gdbarch
))
2175 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2176 value_contents (val
));
2178 return unpack_long (value_type (val
), value_contents (val
));
2182 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2183 as a long, or as a double, assuming the raw data is described
2184 by type TYPE. Knows how to convert different sizes of values
2185 and can convert between fixed and floating point. We don't assume
2186 any alignment for the raw data. Return value is in host byte order.
2188 If you want functions and arrays to be coerced to pointers, and
2189 references to be dereferenced, call value_as_long() instead.
2191 C++: It is assumed that the front-end has taken care of
2192 all matters concerning pointers to members. A pointer
2193 to member which reaches here is considered to be equivalent
2194 to an INT (or some size). After all, it is only an offset. */
2197 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2199 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2200 enum type_code code
= TYPE_CODE (type
);
2201 int len
= TYPE_LENGTH (type
);
2202 int nosign
= TYPE_UNSIGNED (type
);
2206 case TYPE_CODE_TYPEDEF
:
2207 return unpack_long (check_typedef (type
), valaddr
);
2208 case TYPE_CODE_ENUM
:
2209 case TYPE_CODE_FLAGS
:
2210 case TYPE_CODE_BOOL
:
2212 case TYPE_CODE_CHAR
:
2213 case TYPE_CODE_RANGE
:
2214 case TYPE_CODE_MEMBERPTR
:
2216 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2218 return extract_signed_integer (valaddr
, len
, byte_order
);
2221 return extract_typed_floating (valaddr
, type
);
2223 case TYPE_CODE_DECFLOAT
:
2224 /* libdecnumber has a function to convert from decimal to integer, but
2225 it doesn't work when the decimal number has a fractional part. */
2226 return decimal_to_doublest (valaddr
, len
, byte_order
);
2230 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2231 whether we want this to be true eventually. */
2232 return extract_typed_address (valaddr
, type
);
2235 error (_("Value can't be converted to integer."));
2237 return 0; /* Placate lint. */
2240 /* Return a double value from the specified type and address.
2241 INVP points to an int which is set to 0 for valid value,
2242 1 for invalid value (bad float format). In either case,
2243 the returned double is OK to use. Argument is in target
2244 format, result is in host format. */
2247 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2249 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2250 enum type_code code
;
2254 *invp
= 0; /* Assume valid. */
2255 CHECK_TYPEDEF (type
);
2256 code
= TYPE_CODE (type
);
2257 len
= TYPE_LENGTH (type
);
2258 nosign
= TYPE_UNSIGNED (type
);
2259 if (code
== TYPE_CODE_FLT
)
2261 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2262 floating-point value was valid (using the macro
2263 INVALID_FLOAT). That test/macro have been removed.
2265 It turns out that only the VAX defined this macro and then
2266 only in a non-portable way. Fixing the portability problem
2267 wouldn't help since the VAX floating-point code is also badly
2268 bit-rotten. The target needs to add definitions for the
2269 methods gdbarch_float_format and gdbarch_double_format - these
2270 exactly describe the target floating-point format. The
2271 problem here is that the corresponding floatformat_vax_f and
2272 floatformat_vax_d values these methods should be set to are
2273 also not defined either. Oops!
2275 Hopefully someone will add both the missing floatformat
2276 definitions and the new cases for floatformat_is_valid (). */
2278 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2284 return extract_typed_floating (valaddr
, type
);
2286 else if (code
== TYPE_CODE_DECFLOAT
)
2287 return decimal_to_doublest (valaddr
, len
, byte_order
);
2290 /* Unsigned -- be sure we compensate for signed LONGEST. */
2291 return (ULONGEST
) unpack_long (type
, valaddr
);
2295 /* Signed -- we are OK with unpack_long. */
2296 return unpack_long (type
, valaddr
);
2300 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2301 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2302 We don't assume any alignment for the raw data. Return value is in
2305 If you want functions and arrays to be coerced to pointers, and
2306 references to be dereferenced, call value_as_address() instead.
2308 C++: It is assumed that the front-end has taken care of
2309 all matters concerning pointers to members. A pointer
2310 to member which reaches here is considered to be equivalent
2311 to an INT (or some size). After all, it is only an offset. */
2314 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2316 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2317 whether we want this to be true eventually. */
2318 return unpack_long (type
, valaddr
);
2322 /* Get the value of the FIELDNO'th field (which must be static) of
2323 TYPE. Return NULL if the field doesn't exist or has been
2327 value_static_field (struct type
*type
, int fieldno
)
2329 struct value
*retval
;
2331 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2333 case FIELD_LOC_KIND_PHYSADDR
:
2334 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2335 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2337 case FIELD_LOC_KIND_PHYSNAME
:
2339 char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2340 /* TYPE_FIELD_NAME (type, fieldno); */
2341 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2345 /* With some compilers, e.g. HP aCC, static data members are
2346 reported as non-debuggable symbols. */
2347 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2354 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2355 SYMBOL_VALUE_ADDRESS (msym
));
2359 retval
= value_of_variable (sym
, NULL
);
2363 gdb_assert_not_reached ("unexpected field location kind");
2369 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2370 You have to be careful here, since the size of the data area for the value
2371 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2372 than the old enclosing type, you have to allocate more space for the
2376 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2378 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2380 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2382 val
->enclosing_type
= new_encl_type
;
2385 /* Given a value ARG1 (offset by OFFSET bytes)
2386 of a struct or union type ARG_TYPE,
2387 extract and return the value of one of its (non-static) fields.
2388 FIELDNO says which field. */
2391 value_primitive_field (struct value
*arg1
, int offset
,
2392 int fieldno
, struct type
*arg_type
)
2397 CHECK_TYPEDEF (arg_type
);
2398 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2400 /* Call check_typedef on our type to make sure that, if TYPE
2401 is a TYPE_CODE_TYPEDEF, its length is set to the length
2402 of the target type instead of zero. However, we do not
2403 replace the typedef type by the target type, because we want
2404 to keep the typedef in order to be able to print the type
2405 description correctly. */
2406 check_typedef (type
);
2408 /* Handle packed fields */
2410 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2412 /* Create a new value for the bitfield, with bitpos and bitsize
2413 set. If possible, arrange offset and bitpos so that we can
2414 do a single aligned read of the size of the containing type.
2415 Otherwise, adjust offset to the byte containing the first
2416 bit. Assume that the address, offset, and embedded offset
2417 are sufficiently aligned. */
2418 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2419 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2421 v
= allocate_value_lazy (type
);
2422 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2423 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2424 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2425 v
->bitpos
= bitpos
% container_bitsize
;
2427 v
->bitpos
= bitpos
% 8;
2428 v
->offset
= (value_embedded_offset (arg1
)
2430 + (bitpos
- v
->bitpos
) / 8);
2432 value_incref (v
->parent
);
2433 if (!value_lazy (arg1
))
2434 value_fetch_lazy (v
);
2436 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2438 /* This field is actually a base subobject, so preserve the
2439 entire object's contents for later references to virtual
2442 /* Lazy register values with offsets are not supported. */
2443 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2444 value_fetch_lazy (arg1
);
2446 if (value_lazy (arg1
))
2447 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2450 v
= allocate_value (value_enclosing_type (arg1
));
2451 memcpy (value_contents_all_raw (v
), value_contents_all_raw (arg1
),
2452 TYPE_LENGTH (value_enclosing_type (arg1
)));
2455 v
->offset
= value_offset (arg1
);
2456 v
->embedded_offset
= (offset
+ value_embedded_offset (arg1
)
2457 + TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8);
2461 /* Plain old data member */
2462 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2464 /* Lazy register values with offsets are not supported. */
2465 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2466 value_fetch_lazy (arg1
);
2468 if (value_lazy (arg1
))
2469 v
= allocate_value_lazy (type
);
2472 v
= allocate_value (type
);
2473 memcpy (value_contents_raw (v
),
2474 value_contents_raw (arg1
) + offset
,
2475 TYPE_LENGTH (type
));
2477 v
->offset
= (value_offset (arg1
) + offset
2478 + value_embedded_offset (arg1
));
2480 set_value_component_location (v
, arg1
);
2481 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2482 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2486 /* Given a value ARG1 of a struct or union type,
2487 extract and return the value of one of its (non-static) fields.
2488 FIELDNO says which field. */
2491 value_field (struct value
*arg1
, int fieldno
)
2493 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2496 /* Return a non-virtual function as a value.
2497 F is the list of member functions which contains the desired method.
2498 J is an index into F which provides the desired method.
2500 We only use the symbol for its address, so be happy with either a
2501 full symbol or a minimal symbol. */
2504 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2505 int j
, struct type
*type
,
2509 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2510 char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2512 struct minimal_symbol
*msym
;
2514 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2521 gdb_assert (sym
== NULL
);
2522 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2527 v
= allocate_value (ftype
);
2530 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2534 /* The minimal symbol might point to a function descriptor;
2535 resolve it to the actual code address instead. */
2536 struct objfile
*objfile
= msymbol_objfile (msym
);
2537 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2539 set_value_address (v
,
2540 gdbarch_convert_from_func_ptr_addr
2541 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2546 if (type
!= value_type (*arg1p
))
2547 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2548 value_addr (*arg1p
)));
2550 /* Move the `this' pointer according to the offset.
2551 VALUE_OFFSET (*arg1p) += offset; */
2558 /* Unpack a bitfield of the specified FIELD_TYPE, from the anonymous
2559 object at VALADDR. The bitfield starts at BITPOS bits and contains
2562 Extracting bits depends on endianness of the machine. Compute the
2563 number of least significant bits to discard. For big endian machines,
2564 we compute the total number of bits in the anonymous object, subtract
2565 off the bit count from the MSB of the object to the MSB of the
2566 bitfield, then the size of the bitfield, which leaves the LSB discard
2567 count. For little endian machines, the discard count is simply the
2568 number of bits from the LSB of the anonymous object to the LSB of the
2571 If the field is signed, we also do sign extension. */
2574 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2575 int bitpos
, int bitsize
)
2577 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2583 /* Read the minimum number of bytes required; there may not be
2584 enough bytes to read an entire ULONGEST. */
2585 CHECK_TYPEDEF (field_type
);
2587 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2589 bytes_read
= TYPE_LENGTH (field_type
);
2591 val
= extract_unsigned_integer (valaddr
+ bitpos
/ 8,
2592 bytes_read
, byte_order
);
2594 /* Extract bits. See comment above. */
2596 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2597 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2599 lsbcount
= (bitpos
% 8);
2602 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2603 If the field is signed, and is negative, then sign extend. */
2605 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2607 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2609 if (!TYPE_UNSIGNED (field_type
))
2611 if (val
& (valmask
^ (valmask
>> 1)))
2620 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
2621 VALADDR. See unpack_bits_as_long for more details. */
2624 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2626 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2627 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2628 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2630 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
2633 /* Modify the value of a bitfield. ADDR points to a block of memory in
2634 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2635 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2636 indicate which bits (in target bit order) comprise the bitfield.
2637 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2638 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2641 modify_field (struct type
*type
, gdb_byte
*addr
,
2642 LONGEST fieldval
, int bitpos
, int bitsize
)
2644 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2646 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
2649 /* Normalize BITPOS. */
2653 /* If a negative fieldval fits in the field in question, chop
2654 off the sign extension bits. */
2655 if ((~fieldval
& ~(mask
>> 1)) == 0)
2658 /* Warn if value is too big to fit in the field in question. */
2659 if (0 != (fieldval
& ~mask
))
2661 /* FIXME: would like to include fieldval in the message, but
2662 we don't have a sprintf_longest. */
2663 warning (_("Value does not fit in %d bits."), bitsize
);
2665 /* Truncate it, otherwise adjoining fields may be corrupted. */
2669 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2670 false valgrind reports. */
2672 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
2673 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
2675 /* Shifting for bit field depends on endianness of the target machine. */
2676 if (gdbarch_bits_big_endian (get_type_arch (type
)))
2677 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
2679 oword
&= ~(mask
<< bitpos
);
2680 oword
|= fieldval
<< bitpos
;
2682 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
2685 /* Pack NUM into BUF using a target format of TYPE. */
2688 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
2690 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2693 type
= check_typedef (type
);
2694 len
= TYPE_LENGTH (type
);
2696 switch (TYPE_CODE (type
))
2699 case TYPE_CODE_CHAR
:
2700 case TYPE_CODE_ENUM
:
2701 case TYPE_CODE_FLAGS
:
2702 case TYPE_CODE_BOOL
:
2703 case TYPE_CODE_RANGE
:
2704 case TYPE_CODE_MEMBERPTR
:
2705 store_signed_integer (buf
, len
, byte_order
, num
);
2710 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2714 error (_("Unexpected type (%d) encountered for integer constant."),
2720 /* Pack NUM into BUF using a target format of TYPE. */
2723 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
2726 enum bfd_endian byte_order
;
2728 type
= check_typedef (type
);
2729 len
= TYPE_LENGTH (type
);
2730 byte_order
= gdbarch_byte_order (get_type_arch (type
));
2732 switch (TYPE_CODE (type
))
2735 case TYPE_CODE_CHAR
:
2736 case TYPE_CODE_ENUM
:
2737 case TYPE_CODE_FLAGS
:
2738 case TYPE_CODE_BOOL
:
2739 case TYPE_CODE_RANGE
:
2740 case TYPE_CODE_MEMBERPTR
:
2741 store_unsigned_integer (buf
, len
, byte_order
, num
);
2746 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
2750 error (_("Unexpected type (%d) encountered "
2751 "for unsigned integer constant."),
2757 /* Convert C numbers into newly allocated values. */
2760 value_from_longest (struct type
*type
, LONGEST num
)
2762 struct value
*val
= allocate_value (type
);
2764 pack_long (value_contents_raw (val
), type
, num
);
2769 /* Convert C unsigned numbers into newly allocated values. */
2772 value_from_ulongest (struct type
*type
, ULONGEST num
)
2774 struct value
*val
= allocate_value (type
);
2776 pack_unsigned_long (value_contents_raw (val
), type
, num
);
2782 /* Create a value representing a pointer of type TYPE to the address
2785 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
2787 struct value
*val
= allocate_value (type
);
2789 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
2794 /* Create a value of type TYPE whose contents come from VALADDR, if it
2795 is non-null, and whose memory address (in the inferior) is
2799 value_from_contents_and_address (struct type
*type
,
2800 const gdb_byte
*valaddr
,
2805 if (valaddr
== NULL
)
2806 v
= allocate_value_lazy (type
);
2809 v
= allocate_value (type
);
2810 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
2812 set_value_address (v
, address
);
2813 VALUE_LVAL (v
) = lval_memory
;
2818 value_from_double (struct type
*type
, DOUBLEST num
)
2820 struct value
*val
= allocate_value (type
);
2821 struct type
*base_type
= check_typedef (type
);
2822 enum type_code code
= TYPE_CODE (base_type
);
2824 if (code
== TYPE_CODE_FLT
)
2826 store_typed_floating (value_contents_raw (val
), base_type
, num
);
2829 error (_("Unexpected type encountered for floating constant."));
2835 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
2837 struct value
*val
= allocate_value (type
);
2839 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
2844 coerce_ref (struct value
*arg
)
2846 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
2848 if (TYPE_CODE (value_type_arg_tmp
) == TYPE_CODE_REF
)
2849 arg
= value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp
),
2850 unpack_pointer (value_type (arg
),
2851 value_contents (arg
)));
2856 coerce_array (struct value
*arg
)
2860 arg
= coerce_ref (arg
);
2861 type
= check_typedef (value_type (arg
));
2863 switch (TYPE_CODE (type
))
2865 case TYPE_CODE_ARRAY
:
2866 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
2867 arg
= value_coerce_array (arg
);
2869 case TYPE_CODE_FUNC
:
2870 arg
= value_coerce_function (arg
);
2877 /* Return true if the function returning the specified type is using
2878 the convention of returning structures in memory (passing in the
2879 address as a hidden first parameter). */
2882 using_struct_return (struct gdbarch
*gdbarch
,
2883 struct type
*func_type
, struct type
*value_type
)
2885 enum type_code code
= TYPE_CODE (value_type
);
2887 if (code
== TYPE_CODE_ERROR
)
2888 error (_("Function return type unknown."));
2890 if (code
== TYPE_CODE_VOID
)
2891 /* A void return value is never in memory. See also corresponding
2892 code in "print_return_value". */
2895 /* Probe the architecture for the return-value convention. */
2896 return (gdbarch_return_value (gdbarch
, func_type
, value_type
,
2898 != RETURN_VALUE_REGISTER_CONVENTION
);
2901 /* Set the initialized field in a value struct. */
2904 set_value_initialized (struct value
*val
, int status
)
2906 val
->initialized
= status
;
2909 /* Return the initialized field in a value struct. */
2912 value_initialized (struct value
*val
)
2914 return val
->initialized
;
2918 _initialize_values (void)
2920 add_cmd ("convenience", no_class
, show_convenience
, _("\
2921 Debugger convenience (\"$foo\") variables.\n\
2922 These variables are created when you assign them values;\n\
2923 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
2925 A few convenience variables are given values automatically:\n\
2926 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
2927 \"$__\" holds the contents of the last address examined with \"x\"."),
2930 add_cmd ("values", no_class
, show_values
, _("\
2931 Elements of value history around item number IDX (or last ten)."),
2934 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
2935 Initialize a convenience variable if necessary.\n\
2936 init-if-undefined VARIABLE = EXPRESSION\n\
2937 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
2938 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
2939 VARIABLE is already initialized."));
2941 add_prefix_cmd ("function", no_class
, function_command
, _("\
2942 Placeholder command for showing help on convenience functions."),
2943 &functionlist
, "function ", 0, &cmdlist
);