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"
42 #include "exceptions.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 /* Functions to call. */
198 const struct lval_funcs *funcs;
200 /* Closure for those functions to use. */
205 /* Describes offset of a value within lval of a structure in bytes.
206 If lval == lval_memory, this is an offset to the address. If
207 lval == lval_register, this is a further offset from
208 location.address within the registers structure. Note also the
209 member embedded_offset below. */
212 /* Only used for bitfields; number of bits contained in them. */
215 /* Only used for bitfields; position of start of field. For
216 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
217 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
220 /* Only used for bitfields; the containing value. This allows a
221 single read from the target when displaying multiple
223 struct value *parent;
225 /* Frame register value is relative to. This will be described in
226 the lval enum above as "lval_register". */
227 struct frame_id frame_id;
229 /* Type of the value. */
232 /* If a value represents a C++ object, then the `type' field gives
233 the object's compile-time type. If the object actually belongs
234 to some class derived from `type', perhaps with other base
235 classes and additional members, then `type' is just a subobject
236 of the real thing, and the full object is probably larger than
237 `type' would suggest.
239 If `type' is a dynamic class (i.e. one with a vtable), then GDB
240 can actually determine the object's run-time type by looking at
241 the run-time type information in the vtable. When this
242 information is available, we may elect to read in the entire
243 object, for several reasons:
245 - When printing the value, the user would probably rather see the
246 full object, not just the limited portion apparent from the
249 - If `type' has virtual base classes, then even printing `type'
250 alone may require reaching outside the `type' portion of the
251 object to wherever the virtual base class has been stored.
253 When we store the entire object, `enclosing_type' is the run-time
254 type -- the complete object -- and `embedded_offset' is the
255 offset of `type' within that larger type, in bytes. The
256 value_contents() macro takes `embedded_offset' into account, so
257 most GDB code continues to see the `type' portion of the value,
258 just as the inferior would.
260 If `type' is a pointer to an object, then `enclosing_type' is a
261 pointer to the object's run-time type, and `pointed_to_offset' is
262 the offset in bytes from the full object to the pointed-to object
263 -- that is, the value `embedded_offset' would have if we followed
264 the pointer and fetched the complete object. (I don't really see
265 the point. Why not just determine the run-time type when you
266 indirect, and avoid the special case? The contents don't matter
267 until you indirect anyway.)
269 If we're not doing anything fancy, `enclosing_type' is equal to
270 `type', and `embedded_offset' is zero, so everything works
272 struct type *enclosing_type;
274 int pointed_to_offset;
276 /* Values are stored in a chain, so that they can be deleted easily
277 over calls to the inferior. Values assigned to internal
278 variables, put into the value history or exposed to Python are
279 taken off this list. */
282 /* Register number if the value is from a register. */
285 /* If zero, contents of this value are in the contents field. If
286 nonzero, contents are in inferior. If the lval field is lval_memory,
287 the contents are in inferior memory at location.address plus offset.
288 The lval field may also be lval_register.
290 WARNING: This field is used by the code which handles watchpoints
291 (see breakpoint.c) to decide whether a particular value can be
292 watched by hardware watchpoints. If the lazy flag is set for
293 some member of a value chain, it is assumed that this member of
294 the chain doesn't need to be watched as part of watching the
295 value itself. This is how GDB avoids watching the entire struct
296 or array when the user wants to watch a single struct member or
297 array element. If you ever change the way lazy flag is set and
298 reset, be sure to consider this use as well! */
301 /* If nonzero, this is the value of a variable which does not
302 actually exist in the program. */
305 /* If value is a variable, is it initialized or not. */
308 /* If value is from the stack. If this is set, read_stack will be
309 used instead of read_memory to enable extra caching. */
312 /* Actual contents of the value. Target byte-order. NULL or not
313 valid if lazy is nonzero. */
316 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
317 rather than available, since the common and default case is for a
318 value to be available. This is filled in at value read time. */
319 VEC(range_s) *unavailable;
321 /* The number of references to this value. When a value is created,
322 the value chain holds a reference, so REFERENCE_COUNT is 1. If
323 release_value is called, this value is removed from the chain but
324 the caller of release_value now has a reference to this value.
325 The caller must arrange for a call to value_free later. */
330 value_bytes_available (const struct value *value, int offset, int length)
332 gdb_assert (!value->lazy);
334 return !ranges_contain (value->unavailable, offset, length);
338 value_entirely_available (struct value *value)
340 /* We can only tell whether the whole value is available when we try
343 value_fetch_lazy (value);
345 if (VEC_empty (range_s, value->unavailable))
351 mark_value_bytes_unavailable (struct value *value, int offset, int length)
356 /* Insert the range sorted. If there's overlap or the new range
357 would be contiguous with an existing range, merge. */
359 newr.offset = offset;
360 newr.length = length;
362 /* Do a binary search for the position the given range would be
363 inserted if we only considered the starting OFFSET of ranges.
364 Call that position I. Since we also have LENGTH to care for
365 (this is a range afterall), we need to check if the _previous_
366 range overlaps the I range. E.g., calling R the new range:
368 #1 - overlaps with previous
372 |---| |---| |------| ... |--|
377 In the case #1 above, the binary search would return `I=1',
378 meaning, this OFFSET should be inserted at position 1, and the
379 current position 1 should be pushed further (and become 2). But,
380 note that `0' overlaps with R, so we want to merge them.
382 A similar consideration needs to be taken if the new range would
383 be contiguous with the previous range:
385 #2 - contiguous with previous
389 |--| |---| |------| ... |--|
394 If there's no overlap with the previous range, as in:
396 #3 - not overlapping and not contiguous
400 |--| |---| |------| ... |--|
407 #4 - R is the range with lowest offset
411 |--| |---| |------| ... |--|
416 ... we just push the new range to I.
418 All the 4 cases above need to consider that the new range may
419 also overlap several of the ranges that follow, or that R may be
420 contiguous with the following range, and merge. E.g.,
422 #5 - overlapping following ranges
425 |------------------------|
426 |--| |---| |------| ... |--|
435 |--| |---| |------| ... |--|
442 i = VEC_lower_bound (range_s, value->unavailable, &newr, range_lessthan);
445 struct range *bef = VEC_index (range_s, value->unavailable, i - 1);
447 if (ranges_overlap (bef->offset, bef->length, offset, length))
450 ULONGEST l = min (bef->offset, offset);
451 ULONGEST h = max (bef->offset + bef->length, offset + length);
457 else if (offset == bef->offset + bef->length)
460 bef->length += length;
466 VEC_safe_insert (range_s, value->unavailable, i, &newr);
472 VEC_safe_insert (range_s, value->unavailable, i, &newr);
475 /* Check whether the ranges following the one we've just added or
476 touched can be folded in (#5 above). */
477 if (i + 1 < VEC_length (range_s, value->unavailable))
484 /* Get the range we just touched. */
485 t = VEC_index (range_s, value->unavailable, i);
489 for (; VEC_iterate (range_s, value->unavailable, i, r); i++)
490 if (r->offset <= t->offset + t->length)
494 l = min (t->offset, r->offset);
495 h = max (t->offset + t->length, r->offset + r->length);
504 /* If we couldn't merge this one, we won't be able to
505 merge following ones either, since the ranges are
506 always sorted by OFFSET. */
511 VEC_block_remove (range_s, value->unavailable, next, removed);
515 /* Find the first range in RANGES that overlaps the range defined by
516 OFFSET and LENGTH, starting at element POS in the RANGES vector,
517 Returns the index into RANGES where such overlapping range was
518 found, or -1 if none was found. */
521 find_first_range_overlap (VEC(range_s) *ranges, int pos,
522 int offset, int length)
527 for (i = pos; VEC_iterate (range_s, ranges, i, r); i++)
528 if (ranges_overlap (r->offset, r->length, offset, length))
535 value_available_contents_eq (const struct value *val1, int offset1,
536 const struct value *val2, int offset2,
539 int idx1 = 0, idx2 = 0;
541 /* This routine is used by printing routines, where we should
542 already have read the value. Note that we only know whether a
543 value chunk is available if we've tried to read it. */
544 gdb_assert (!val1->lazy && !val2->lazy);
552 idx1 = find_first_range_overlap (val1->unavailable, idx1,
554 idx2 = find_first_range_overlap (val2->unavailable, idx2,
557 /* The usual case is for both values to be completely available. */
558 if (idx1 == -1 && idx2 == -1)
559 return (memcmp (val1->contents + offset1,
560 val2->contents + offset2,
562 /* The contents only match equal if the available set matches as
564 else if (idx1 == -1 || idx2 == -1)
567 gdb_assert (idx1 != -1 && idx2 != -1);
569 r1 = VEC_index (range_s, val1->unavailable, idx1);
570 r2 = VEC_index (range_s, val2->unavailable, idx2);
572 /* Get the unavailable windows intersected by the incoming
573 ranges. The first and last ranges that overlap the argument
574 range may be wider than said incoming arguments ranges. */
575 l1 = max (offset1, r1->offset);
576 h1 = min (offset1 + length, r1->offset + r1->length);
578 l2 = max (offset2, r2->offset);
579 h2 = min (offset2 + length, r2->offset + r2->length);
581 /* Make them relative to the respective start offsets, so we can
582 compare them for equality. */
589 /* Different availability, no match. */
590 if (l1 != l2 || h1 != h2)
593 /* Compare the _available_ contents. */
594 if (memcmp (val1->contents + offset1,
595 val2->contents + offset2,
607 /* Prototypes for local functions. */
609 static void show_values (char *, int);
611 static void show_convenience (char *, int);
614 /* The value-history records all the values printed
615 by print commands during this session. Each chunk
616 records 60 consecutive values. The first chunk on
617 the chain records the most recent values.
618 The total number of values is in value_history_count. */
620 #define VALUE_HISTORY_CHUNK 60
622 struct value_history_chunk
624 struct value_history_chunk *next;
625 struct value *values[VALUE_HISTORY_CHUNK];
628 /* Chain of chunks now in use. */
630 static struct value_history_chunk *value_history_chain;
632 static int value_history_count; /* Abs number of last entry stored. */
635 /* List of all value objects currently allocated
636 (except for those released by calls to release_value)
637 This is so they can be freed after each command. */
639 static struct value *all_values;
641 /* Allocate a lazy value for type TYPE. Its actual content is
642 "lazily" allocated too: the content field of the return value is
643 NULL; it will be allocated when it is fetched from the target. */
646 allocate_value_lazy (struct type *type)
650 /* Call check_typedef on our type to make sure that, if TYPE
651 is a TYPE_CODE_TYPEDEF, its length is set to the length
652 of the target type instead of zero. However, we do not
653 replace the typedef type by the target type, because we want
654 to keep the typedef in order to be able to set the VAL's type
655 description correctly. */
656 check_typedef (type);
658 val = (struct value *) xzalloc (sizeof (struct value));
659 val->contents = NULL;
660 val->next = all_values;
663 val->enclosing_type = type;
664 VALUE_LVAL (val) = not_lval;
665 val->location.address = 0;
666 VALUE_FRAME_ID (val) = null_frame_id;
670 VALUE_REGNUM (val) = -1;
672 val->optimized_out = 0;
673 val->embedded_offset = 0;
674 val->pointed_to_offset = 0;
676 val->initialized = 1; /* Default to initialized. */
678 /* Values start out on the all_values chain. */
679 val->reference_count = 1;
684 /* Allocate the contents of VAL if it has not been allocated yet. */
687 allocate_value_contents (struct value *val)
690 val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
693 /* Allocate a value and its contents for type TYPE. */
696 allocate_value (struct type *type)
698 struct value *val = allocate_value_lazy (type);
700 allocate_value_contents (val);
705 /* Allocate a value that has the correct length
706 for COUNT repetitions of type TYPE. */
709 allocate_repeat_value (struct type *type, int count)
711 int low_bound = current_language->string_lower_bound; /* ??? */
712 /* FIXME-type-allocation: need a way to free this type when we are
714 struct type *array_type
715 = lookup_array_range_type (type, low_bound, count + low_bound - 1);
717 return allocate_value (array_type);
721 allocate_computed_value (struct type *type,
722 const struct lval_funcs *funcs,
725 struct value *v = allocate_value_lazy (type);
727 VALUE_LVAL (v) = lval_computed;
728 v->location.computed.funcs = funcs;
729 v->location.computed.closure = closure;
734 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
737 allocate_optimized_out_value (struct type *type)
739 struct value *retval = allocate_value_lazy (type);
741 set_value_optimized_out (retval, 1);
746 /* Accessor methods. */
749 value_next (struct value *value)
755 value_type (const struct value *value)
760 deprecated_set_value_type (struct value *value, struct type *type)
766 value_offset (const struct value *value)
768 return value->offset;
771 set_value_offset (struct value *value, int offset)
773 value->offset = offset;
777 value_bitpos (const struct value *value)
779 return value->bitpos;
782 set_value_bitpos (struct value *value, int bit)
788 value_bitsize (const struct value *value)
790 return value->bitsize;
793 set_value_bitsize (struct value *value, int bit)
795 value->bitsize = bit;
799 value_parent (struct value *value)
801 return value->parent;
805 value_contents_raw (struct value *value)
807 allocate_value_contents (value);
808 return value->contents + value->embedded_offset;
812 value_contents_all_raw (struct value *value)
814 allocate_value_contents (value);
815 return value->contents;
819 value_enclosing_type (struct value *value)
821 return value->enclosing_type;
825 require_not_optimized_out (const struct value *value)
827 if (value->optimized_out)
828 error (_("value has been optimized out"));
832 require_available (const struct value *value)
834 if (!VEC_empty (range_s, value->unavailable))
835 throw_error (NOT_AVAILABLE_ERROR, _("value is not available"));
839 value_contents_for_printing (struct value *value)
842 value_fetch_lazy (value);
843 return value->contents;
847 value_contents_for_printing_const (const struct value *value)
849 gdb_assert (!value->lazy);
850 return value->contents;
854 value_contents_all (struct value *value)
856 const gdb_byte *result = value_contents_for_printing (value);
857 require_not_optimized_out (value);
858 require_available (value);
862 /* Copy LENGTH bytes of SRC value's (all) contents
863 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
864 contents, starting at DST_OFFSET. If unavailable contents are
865 being copied from SRC, the corresponding DST contents are marked
866 unavailable accordingly. Neither DST nor SRC may be lazy
869 It is assumed the contents of DST in the [DST_OFFSET,
870 DST_OFFSET+LENGTH) range are wholly available. */
873 value_contents_copy_raw (struct value *dst, int dst_offset,
874 struct value *src, int src_offset, int length)
879 /* A lazy DST would make that this copy operation useless, since as
880 soon as DST's contents were un-lazied (by a later value_contents
881 call, say), the contents would be overwritten. A lazy SRC would
882 mean we'd be copying garbage. */
883 gdb_assert (!dst->lazy && !src->lazy);
885 /* The overwritten DST range gets unavailability ORed in, not
886 replaced. Make sure to remember to implement replacing if it
887 turns out actually necessary. */
888 gdb_assert (value_bytes_available (dst, dst_offset, length));
891 memcpy (value_contents_all_raw (dst) + dst_offset,
892 value_contents_all_raw (src) + src_offset,
895 /* Copy the meta-data, adjusted. */
896 for (i = 0; VEC_iterate (range_s, src->unavailable, i, r); i++)
900 l = max (r->offset, src_offset);
901 h = min (r->offset + r->length, src_offset + length);
904 mark_value_bytes_unavailable (dst,
905 dst_offset + (l - src_offset),
910 /* Copy LENGTH bytes of SRC value's (all) contents
911 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
912 (all) contents, starting at DST_OFFSET. If unavailable contents
913 are being copied from SRC, the corresponding DST contents are
914 marked unavailable accordingly. DST must not be lazy. If SRC is
915 lazy, it will be fetched now. If SRC is not valid (is optimized
916 out), an error is thrown.
918 It is assumed the contents of DST in the [DST_OFFSET,
919 DST_OFFSET+LENGTH) range are wholly available. */
922 value_contents_copy (struct value *dst, int dst_offset,
923 struct value *src, int src_offset, int length)
925 require_not_optimized_out (src);
928 value_fetch_lazy (src);
930 value_contents_copy_raw (dst, dst_offset, src, src_offset, length);
934 value_lazy (struct value *value)
940 set_value_lazy (struct value *value, int val)
946 value_stack (struct value *value)
952 set_value_stack (struct value *value, int val)
958 value_contents (struct value *value)
960 const gdb_byte *result = value_contents_writeable (value);
961 require_not_optimized_out (value);
962 require_available (value);
967 value_contents_writeable (struct value *value)
970 value_fetch_lazy (value);
971 return value_contents_raw (value);
974 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
975 this function is different from value_equal; in C the operator ==
976 can return 0 even if the two values being compared are equal. */
979 value_contents_equal (struct value *val1, struct value *val2)
985 type1 = check_typedef (value_type (val1));
986 type2 = check_typedef (value_type (val2));
987 len = TYPE_LENGTH (type1);
988 if (len != TYPE_LENGTH (type2))
991 return (memcmp (value_contents (val1), value_contents (val2), len) == 0);
995 value_optimized_out (struct value *value)
997 return value->optimized_out;
1001 set_value_optimized_out (struct value *value, int val)
1003 value->optimized_out = val;
1007 value_entirely_optimized_out (const struct value *value)
1009 if (!value->optimized_out)
1011 if (value->lval != lval_computed
1012 || !value->location.computed.funcs->check_any_valid)
1014 return !value->location.computed.funcs->check_any_valid (value);
1018 value_bits_valid (const struct value *value, int offset, int length)
1020 if (!value->optimized_out)
1022 if (value->lval != lval_computed
1023 || !value->location.computed.funcs->check_validity)
1025 return value->location.computed.funcs->check_validity (value, offset,
1030 value_bits_synthetic_pointer (const struct value *value,
1031 int offset, int length)
1033 if (value->lval != lval_computed
1034 || !value->location.computed.funcs->check_synthetic_pointer)
1036 return value->location.computed.funcs->check_synthetic_pointer (value,
1042 value_embedded_offset (struct value *value)
1044 return value->embedded_offset;
1048 set_value_embedded_offset (struct value *value, int val)
1050 value->embedded_offset = val;
1054 value_pointed_to_offset (struct value *value)
1056 return value->pointed_to_offset;
1060 set_value_pointed_to_offset (struct value *value, int val)
1062 value->pointed_to_offset = val;
1065 const struct lval_funcs *
1066 value_computed_funcs (struct value *v)
1068 gdb_assert (VALUE_LVAL (v) == lval_computed);
1070 return v->location.computed.funcs;
1074 value_computed_closure (const struct value *v)
1076 gdb_assert (v->lval == lval_computed);
1078 return v->location.computed.closure;
1082 deprecated_value_lval_hack (struct value *value)
1084 return &value->lval;
1088 value_address (const struct value *value)
1090 if (value->lval == lval_internalvar
1091 || value->lval == lval_internalvar_component)
1093 return value->location.address + value->offset;
1097 value_raw_address (struct value *value)
1099 if (value->lval == lval_internalvar
1100 || value->lval == lval_internalvar_component)
1102 return value->location.address;
1106 set_value_address (struct value *value, CORE_ADDR addr)
1108 gdb_assert (value->lval != lval_internalvar
1109 && value->lval != lval_internalvar_component);
1110 value->location.address = addr;
1113 struct internalvar **
1114 deprecated_value_internalvar_hack (struct value *value)
1116 return &value->location.internalvar;
1120 deprecated_value_frame_id_hack (struct value *value)
1122 return &value->frame_id;
1126 deprecated_value_regnum_hack (struct value *value)
1128 return &value->regnum;
1132 deprecated_value_modifiable (struct value *value)
1134 return value->modifiable;
1137 deprecated_set_value_modifiable (struct value *value, int modifiable)
1139 value->modifiable = modifiable;
1142 /* Return a mark in the value chain. All values allocated after the
1143 mark is obtained (except for those released) are subject to being freed
1144 if a subsequent value_free_to_mark is passed the mark. */
1151 /* Take a reference to VAL. VAL will not be deallocated until all
1152 references are released. */
1155 value_incref (struct value *val)
1157 val->reference_count++;
1160 /* Release a reference to VAL, which was acquired with value_incref.
1161 This function is also called to deallocate values from the value
1165 value_free (struct value *val)
1169 gdb_assert (val->reference_count > 0);
1170 val->reference_count--;
1171 if (val->reference_count > 0)
1174 /* If there's an associated parent value, drop our reference to
1176 if (val->parent != NULL)
1177 value_free (val->parent);
1179 if (VALUE_LVAL (val) == lval_computed)
1181 const struct lval_funcs *funcs = val->location.computed.funcs;
1183 if (funcs->free_closure)
1184 funcs->free_closure (val);
1187 xfree (val->contents);
1188 VEC_free (range_s, val->unavailable);
1193 /* Free all values allocated since MARK was obtained by value_mark
1194 (except for those released). */
1196 value_free_to_mark (struct value *mark)
1201 for (val = all_values; val && val != mark; val = next)
1209 /* Free all the values that have been allocated (except for those released).
1210 Call after each command, successful or not.
1211 In practice this is called before each command, which is sufficient. */
1214 free_all_values (void)
1219 for (val = all_values; val; val = next)
1228 /* Frees all the elements in a chain of values. */
1231 free_value_chain (struct value *v)
1237 next = value_next (v);
1242 /* Remove VAL from the chain all_values
1243 so it will not be freed automatically. */
1246 release_value (struct value *val)
1250 if (all_values == val)
1252 all_values = val->next;
1257 for (v = all_values; v; v = v->next)
1261 v->next = val->next;
1268 /* Release all values up to mark */
1270 value_release_to_mark (struct value *mark)
1275 for (val = next = all_values; next; next = next->next)
1276 if (next->next == mark)
1278 all_values = next->next;
1286 /* Return a copy of the value ARG.
1287 It contains the same contents, for same memory address,
1288 but it's a different block of storage. */
1291 value_copy (struct value *arg)
1293 struct type *encl_type = value_enclosing_type (arg);
1296 if (value_lazy (arg))
1297 val = allocate_value_lazy (encl_type);
1299 val = allocate_value (encl_type);
1300 val->type = arg->type;
1301 VALUE_LVAL (val) = VALUE_LVAL (arg);
1302 val->location = arg->location;
1303 val->offset = arg->offset;
1304 val->bitpos = arg->bitpos;
1305 val->bitsize = arg->bitsize;
1306 VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
1307 VALUE_REGNUM (val) = VALUE_REGNUM (arg);
1308 val->lazy = arg->lazy;
1309 val->optimized_out = arg->optimized_out;
1310 val->embedded_offset = value_embedded_offset (arg);
1311 val->pointed_to_offset = arg->pointed_to_offset;
1312 val->modifiable = arg->modifiable;
1313 if (!value_lazy (val))
1315 memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
1316 TYPE_LENGTH (value_enclosing_type (arg)));
1319 val->unavailable = VEC_copy (range_s, arg->unavailable);
1320 val->parent = arg->parent;
1322 value_incref (val->parent);
1323 if (VALUE_LVAL (val) == lval_computed)
1325 const struct lval_funcs *funcs = val->location.computed.funcs;
1327 if (funcs->copy_closure)
1328 val->location.computed.closure = funcs->copy_closure (val);
1333 /* Return a version of ARG that is non-lvalue. */
1336 value_non_lval (struct value *arg)
1338 if (VALUE_LVAL (arg) != not_lval)
1340 struct type *enc_type = value_enclosing_type (arg);
1341 struct value *val = allocate_value (enc_type);
1343 memcpy (value_contents_all_raw (val), value_contents_all (arg),
1344 TYPE_LENGTH (enc_type));
1345 val->type = arg->type;
1346 set_value_embedded_offset (val, value_embedded_offset (arg));
1347 set_value_pointed_to_offset (val, value_pointed_to_offset (arg));
1354 set_value_component_location (struct value *component,
1355 const struct value *whole)
1357 if (whole->lval == lval_internalvar)
1358 VALUE_LVAL (component) = lval_internalvar_component;
1360 VALUE_LVAL (component) = whole->lval;
1362 component->location = whole->location;
1363 if (whole->lval == lval_computed)
1365 const struct lval_funcs *funcs = whole->location.computed.funcs;
1367 if (funcs->copy_closure)
1368 component->location.computed.closure = funcs->copy_closure (whole);
1373 /* Access to the value history. */
1375 /* Record a new value in the value history.
1376 Returns the absolute history index of the entry.
1377 Result of -1 indicates the value was not saved; otherwise it is the
1378 value history index of this new item. */
1381 record_latest_value (struct value *val)
1385 /* We don't want this value to have anything to do with the inferior anymore.
1386 In particular, "set $1 = 50" should not affect the variable from which
1387 the value was taken, and fast watchpoints should be able to assume that
1388 a value on the value history never changes. */
1389 if (value_lazy (val))
1390 value_fetch_lazy (val);
1391 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1392 from. This is a bit dubious, because then *&$1 does not just return $1
1393 but the current contents of that location. c'est la vie... */
1394 val->modifiable = 0;
1395 release_value (val);
1397 /* Here we treat value_history_count as origin-zero
1398 and applying to the value being stored now. */
1400 i = value_history_count % VALUE_HISTORY_CHUNK;
1403 struct value_history_chunk *new
1404 = (struct value_history_chunk *)
1406 xmalloc (sizeof (struct value_history_chunk));
1407 memset (new->values, 0, sizeof new->values);
1408 new->next = value_history_chain;
1409 value_history_chain = new;
1412 value_history_chain->values[i] = val;
1414 /* Now we regard value_history_count as origin-one
1415 and applying to the value just stored. */
1417 return ++value_history_count;
1420 /* Return a copy of the value in the history with sequence number NUM. */
1423 access_value_history (int num)
1425 struct value_history_chunk *chunk;
1430 absnum += value_history_count;
1435 error (_("The history is empty."));
1437 error (_("There is only one value in the history."));
1439 error (_("History does not go back to $$%d."), -num);
1441 if (absnum > value_history_count)
1442 error (_("History has not yet reached $%d."), absnum);
1446 /* Now absnum is always absolute and origin zero. */
1448 chunk = value_history_chain;
1449 for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK
1450 - absnum / VALUE_HISTORY_CHUNK;
1452 chunk = chunk->next;
1454 return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
1458 show_values (char *num_exp, int from_tty)
1466 /* "show values +" should print from the stored position.
1467 "show values <exp>" should print around value number <exp>. */
1468 if (num_exp[0] != '+' || num_exp[1] != '\0')
1469 num = parse_and_eval_long (num_exp) - 5;
1473 /* "show values" means print the last 10 values. */
1474 num = value_history_count - 9;
1480 for (i = num; i < num + 10 && i <= value_history_count; i++)
1482 struct value_print_options opts;
1484 val = access_value_history (i);
1485 printf_filtered (("$%d = "), i);
1486 get_user_print_options (&opts);
1487 value_print (val, gdb_stdout, &opts);
1488 printf_filtered (("\n"));
1491 /* The next "show values +" should start after what we just printed. */
1494 /* Hitting just return after this command should do the same thing as
1495 "show values +". If num_exp is null, this is unnecessary, since
1496 "show values +" is not useful after "show values". */
1497 if (from_tty && num_exp)
1504 /* Internal variables. These are variables within the debugger
1505 that hold values assigned by debugger commands.
1506 The user refers to them with a '$' prefix
1507 that does not appear in the variable names stored internally. */
1511 struct internalvar *next;
1514 /* We support various different kinds of content of an internal variable.
1515 enum internalvar_kind specifies the kind, and union internalvar_data
1516 provides the data associated with this particular kind. */
1518 enum internalvar_kind
1520 /* The internal variable is empty. */
1523 /* The value of the internal variable is provided directly as
1524 a GDB value object. */
1527 /* A fresh value is computed via a call-back routine on every
1528 access to the internal variable. */
1529 INTERNALVAR_MAKE_VALUE,
1531 /* The internal variable holds a GDB internal convenience function. */
1532 INTERNALVAR_FUNCTION,
1534 /* The variable holds an integer value. */
1535 INTERNALVAR_INTEGER,
1537 /* The variable holds a GDB-provided string. */
1542 union internalvar_data
1544 /* A value object used with INTERNALVAR_VALUE. */
1545 struct value *value;
1547 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1548 internalvar_make_value make_value;
1550 /* The internal function used with INTERNALVAR_FUNCTION. */
1553 struct internal_function *function;
1554 /* True if this is the canonical name for the function. */
1558 /* An integer value used with INTERNALVAR_INTEGER. */
1561 /* If type is non-NULL, it will be used as the type to generate
1562 a value for this internal variable. If type is NULL, a default
1563 integer type for the architecture is used. */
1568 /* A string value used with INTERNALVAR_STRING. */
1573 static struct internalvar *internalvars;
1575 /* If the variable does not already exist create it and give it the
1576 value given. If no value is given then the default is zero. */
1578 init_if_undefined_command (char* args, int from_tty)
1580 struct internalvar* intvar;
1582 /* Parse the expression - this is taken from set_command(). */
1583 struct expression *expr = parse_expression (args);
1584 register struct cleanup *old_chain =
1585 make_cleanup (free_current_contents, &expr);
1587 /* Validate the expression.
1588 Was the expression an assignment?
1589 Or even an expression at all? */
1590 if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
1591 error (_("Init-if-undefined requires an assignment expression."));
1593 /* Extract the variable from the parsed expression.
1594 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1595 if (expr->elts[1].opcode != OP_INTERNALVAR)
1596 error (_("The first parameter to init-if-undefined "
1597 "should be a GDB variable."));
1598 intvar = expr->elts[2].internalvar;
1600 /* Only evaluate the expression if the lvalue is void.
1601 This may still fail if the expresssion is invalid. */
1602 if (intvar->kind == INTERNALVAR_VOID)
1603 evaluate_expression (expr);
1605 do_cleanups (old_chain);
1609 /* Look up an internal variable with name NAME. NAME should not
1610 normally include a dollar sign.
1612 If the specified internal variable does not exist,
1613 the return value is NULL. */
1615 struct internalvar *
1616 lookup_only_internalvar (const char *name)
1618 struct internalvar *var;
1620 for (var = internalvars; var; var = var->next)
1621 if (strcmp (var->name, name) == 0)
1628 /* Create an internal variable with name NAME and with a void value.
1629 NAME should not normally include a dollar sign. */
1631 struct internalvar *
1632 create_internalvar (const char *name)
1634 struct internalvar *var;
1636 var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
1637 var->name = concat (name, (char *)NULL);
1638 var->kind = INTERNALVAR_VOID;
1639 var->next = internalvars;
1644 /* Create an internal variable with name NAME and register FUN as the
1645 function that value_of_internalvar uses to create a value whenever
1646 this variable is referenced. NAME should not normally include a
1649 struct internalvar *
1650 create_internalvar_type_lazy (char *name, internalvar_make_value fun)
1652 struct internalvar *var = create_internalvar (name);
1654 var->kind = INTERNALVAR_MAKE_VALUE;
1655 var->u.make_value = fun;
1659 /* Look up an internal variable with name NAME. NAME should not
1660 normally include a dollar sign.
1662 If the specified internal variable does not exist,
1663 one is created, with a void value. */
1665 struct internalvar *
1666 lookup_internalvar (const char *name)
1668 struct internalvar *var;
1670 var = lookup_only_internalvar (name);
1674 return create_internalvar (name);
1677 /* Return current value of internal variable VAR. For variables that
1678 are not inherently typed, use a value type appropriate for GDBARCH. */
1681 value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
1684 struct trace_state_variable *tsv;
1686 /* If there is a trace state variable of the same name, assume that
1687 is what we really want to see. */
1688 tsv = find_trace_state_variable (var->name);
1691 tsv->value_known = target_get_trace_state_variable_value (tsv->number,
1693 if (tsv->value_known)
1694 val = value_from_longest (builtin_type (gdbarch)->builtin_int64,
1697 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1703 case INTERNALVAR_VOID:
1704 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1707 case INTERNALVAR_FUNCTION:
1708 val = allocate_value (builtin_type (gdbarch)->internal_fn);
1711 case INTERNALVAR_INTEGER:
1712 if (!var->u.integer.type)
1713 val = value_from_longest (builtin_type (gdbarch)->builtin_int,
1714 var->u.integer.val);
1716 val = value_from_longest (var->u.integer.type, var->u.integer.val);
1719 case INTERNALVAR_STRING:
1720 val = value_cstring (var->u.string, strlen (var->u.string),
1721 builtin_type (gdbarch)->builtin_char);
1724 case INTERNALVAR_VALUE:
1725 val = value_copy (var->u.value);
1726 if (value_lazy (val))
1727 value_fetch_lazy (val);
1730 case INTERNALVAR_MAKE_VALUE:
1731 val = (*var->u.make_value) (gdbarch, var);
1735 internal_error (__FILE__, __LINE__, _("bad kind"));
1738 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1739 on this value go back to affect the original internal variable.
1741 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1742 no underlying modifyable state in the internal variable.
1744 Likewise, if the variable's value is a computed lvalue, we want
1745 references to it to produce another computed lvalue, where
1746 references and assignments actually operate through the
1747 computed value's functions.
1749 This means that internal variables with computed values
1750 behave a little differently from other internal variables:
1751 assignments to them don't just replace the previous value
1752 altogether. At the moment, this seems like the behavior we
1755 if (var->kind != INTERNALVAR_MAKE_VALUE
1756 && val->lval != lval_computed)
1758 VALUE_LVAL (val) = lval_internalvar;
1759 VALUE_INTERNALVAR (val) = var;
1766 get_internalvar_integer (struct internalvar *var, LONGEST *result)
1768 if (var->kind == INTERNALVAR_INTEGER)
1770 *result = var->u.integer.val;
1774 if (var->kind == INTERNALVAR_VALUE)
1776 struct type *type = check_typedef (value_type (var->u.value));
1778 if (TYPE_CODE (type) == TYPE_CODE_INT)
1780 *result = value_as_long (var->u.value);
1789 get_internalvar_function (struct internalvar *var,
1790 struct internal_function **result)
1794 case INTERNALVAR_FUNCTION:
1795 *result = var->u.fn.function;
1804 set_internalvar_component (struct internalvar *var, int offset, int bitpos,
1805 int bitsize, struct value *newval)
1811 case INTERNALVAR_VALUE:
1812 addr = value_contents_writeable (var->u.value);
1815 modify_field (value_type (var->u.value), addr + offset,
1816 value_as_long (newval), bitpos, bitsize);
1818 memcpy (addr + offset, value_contents (newval),
1819 TYPE_LENGTH (value_type (newval)));
1823 /* We can never get a component of any other kind. */
1824 internal_error (__FILE__, __LINE__, _("set_internalvar_component"));
1829 set_internalvar (struct internalvar *var, struct value *val)
1831 enum internalvar_kind new_kind;
1832 union internalvar_data new_data = { 0 };
1834 if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
1835 error (_("Cannot overwrite convenience function %s"), var->name);
1837 /* Prepare new contents. */
1838 switch (TYPE_CODE (check_typedef (value_type (val))))
1840 case TYPE_CODE_VOID:
1841 new_kind = INTERNALVAR_VOID;
1844 case TYPE_CODE_INTERNAL_FUNCTION:
1845 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1846 new_kind = INTERNALVAR_FUNCTION;
1847 get_internalvar_function (VALUE_INTERNALVAR (val),
1848 &new_data.fn.function);
1849 /* Copies created here are never canonical. */
1853 new_kind = INTERNALVAR_VALUE;
1854 new_data.value = value_copy (val);
1855 new_data.value->modifiable = 1;
1857 /* Force the value to be fetched from the target now, to avoid problems
1858 later when this internalvar is referenced and the target is gone or
1860 if (value_lazy (new_data.value))
1861 value_fetch_lazy (new_data.value);
1863 /* Release the value from the value chain to prevent it from being
1864 deleted by free_all_values. From here on this function should not
1865 call error () until new_data is installed into the var->u to avoid
1867 release_value (new_data.value);
1871 /* Clean up old contents. */
1872 clear_internalvar (var);
1875 var->kind = new_kind;
1877 /* End code which must not call error(). */
1881 set_internalvar_integer (struct internalvar *var, LONGEST l)
1883 /* Clean up old contents. */
1884 clear_internalvar (var);
1886 var->kind = INTERNALVAR_INTEGER;
1887 var->u.integer.type = NULL;
1888 var->u.integer.val = l;
1892 set_internalvar_string (struct internalvar *var, const char *string)
1894 /* Clean up old contents. */
1895 clear_internalvar (var);
1897 var->kind = INTERNALVAR_STRING;
1898 var->u.string = xstrdup (string);
1902 set_internalvar_function (struct internalvar *var, struct internal_function *f)
1904 /* Clean up old contents. */
1905 clear_internalvar (var);
1907 var->kind = INTERNALVAR_FUNCTION;
1908 var->u.fn.function = f;
1909 var->u.fn.canonical = 1;
1910 /* Variables installed here are always the canonical version. */
1914 clear_internalvar (struct internalvar *var)
1916 /* Clean up old contents. */
1919 case INTERNALVAR_VALUE:
1920 value_free (var->u.value);
1923 case INTERNALVAR_STRING:
1924 xfree (var->u.string);
1931 /* Reset to void kind. */
1932 var->kind = INTERNALVAR_VOID;
1936 internalvar_name (struct internalvar *var)
1941 static struct internal_function *
1942 create_internal_function (const char *name,
1943 internal_function_fn handler, void *cookie)
1945 struct internal_function *ifn = XNEW (struct internal_function);
1947 ifn->name = xstrdup (name);
1948 ifn->handler = handler;
1949 ifn->cookie = cookie;
1954 value_internal_function_name (struct value *val)
1956 struct internal_function *ifn;
1959 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1960 result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
1961 gdb_assert (result);
1967 call_internal_function (struct gdbarch *gdbarch,
1968 const struct language_defn *language,
1969 struct value *func, int argc, struct value **argv)
1971 struct internal_function *ifn;
1974 gdb_assert (VALUE_LVAL (func) == lval_internalvar);
1975 result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
1976 gdb_assert (result);
1978 return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
1981 /* The 'function' command. This does nothing -- it is just a
1982 placeholder to let "help function NAME" work. This is also used as
1983 the implementation of the sub-command that is created when
1984 registering an internal function. */
1986 function_command (char *command, int from_tty)
1991 /* Clean up if an internal function's command is destroyed. */
1993 function_destroyer (struct cmd_list_element *self, void *ignore)
1999 /* Add a new internal function. NAME is the name of the function; DOC
2000 is a documentation string describing the function. HANDLER is
2001 called when the function is invoked. COOKIE is an arbitrary
2002 pointer which is passed to HANDLER and is intended for "user
2005 add_internal_function (const char *name, const char *doc,
2006 internal_function_fn handler, void *cookie)
2008 struct cmd_list_element *cmd;
2009 struct internal_function *ifn;
2010 struct internalvar *var = lookup_internalvar (name);
2012 ifn = create_internal_function (name, handler, cookie);
2013 set_internalvar_function (var, ifn);
2015 cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
2017 cmd->destroyer = function_destroyer;
2020 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2021 prevent cycles / duplicates. */
2024 preserve_one_value (struct value *value, struct objfile *objfile,
2025 htab_t copied_types)
2027 if (TYPE_OBJFILE (value->type) == objfile)
2028 value->type = copy_type_recursive (objfile, value->type, copied_types);
2030 if (TYPE_OBJFILE (value->enclosing_type) == objfile)
2031 value->enclosing_type = copy_type_recursive (objfile,
2032 value->enclosing_type,
2036 /* Likewise for internal variable VAR. */
2039 preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
2040 htab_t copied_types)
2044 case INTERNALVAR_INTEGER:
2045 if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
2047 = copy_type_recursive (objfile, var->u.integer.type, copied_types);
2050 case INTERNALVAR_VALUE:
2051 preserve_one_value (var->u.value, objfile, copied_types);
2056 /* Update the internal variables and value history when OBJFILE is
2057 discarded; we must copy the types out of the objfile. New global types
2058 will be created for every convenience variable which currently points to
2059 this objfile's types, and the convenience variables will be adjusted to
2060 use the new global types. */
2063 preserve_values (struct objfile *objfile)
2065 htab_t copied_types;
2066 struct value_history_chunk *cur;
2067 struct internalvar *var;
2070 /* Create the hash table. We allocate on the objfile's obstack, since
2071 it is soon to be deleted. */
2072 copied_types = create_copied_types_hash (objfile);
2074 for (cur = value_history_chain; cur; cur = cur->next)
2075 for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
2077 preserve_one_value (cur->values[i], objfile, copied_types);
2079 for (var = internalvars; var; var = var->next)
2080 preserve_one_internalvar (var, objfile, copied_types);
2082 preserve_python_values (objfile, copied_types);
2084 htab_delete (copied_types);
2088 show_convenience (char *ignore, int from_tty)
2090 struct gdbarch *gdbarch = get_current_arch ();
2091 struct internalvar *var;
2093 struct value_print_options opts;
2095 get_user_print_options (&opts);
2096 for (var = internalvars; var; var = var->next)
2102 printf_filtered (("$%s = "), var->name);
2103 value_print (value_of_internalvar (gdbarch, var), gdb_stdout,
2105 printf_filtered (("\n"));
2108 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2109 "Convenience variables have "
2110 "names starting with \"$\";\n"
2111 "use \"set\" as in \"set "
2112 "$foo = 5\" to define them.\n"));
2115 /* Extract a value as a C number (either long or double).
2116 Knows how to convert fixed values to double, or
2117 floating values to long.
2118 Does not deallocate the value. */
2121 value_as_long (struct value *val)
2123 /* This coerces arrays and functions, which is necessary (e.g.
2124 in disassemble_command). It also dereferences references, which
2125 I suspect is the most logical thing to do. */
2126 val = coerce_array (val);
2127 return unpack_long (value_type (val), value_contents (val));
2131 value_as_double (struct value *val)
2136 foo = unpack_double (value_type (val), value_contents (val), &inv);
2138 error (_("Invalid floating value found in program."));
2142 /* Extract a value as a C pointer. Does not deallocate the value.
2143 Note that val's type may not actually be a pointer; value_as_long
2144 handles all the cases. */
2146 value_as_address (struct value *val)
2148 struct gdbarch *gdbarch = get_type_arch (value_type (val));
2150 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2151 whether we want this to be true eventually. */
2153 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2154 non-address (e.g. argument to "signal", "info break", etc.), or
2155 for pointers to char, in which the low bits *are* significant. */
2156 return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
2159 /* There are several targets (IA-64, PowerPC, and others) which
2160 don't represent pointers to functions as simply the address of
2161 the function's entry point. For example, on the IA-64, a
2162 function pointer points to a two-word descriptor, generated by
2163 the linker, which contains the function's entry point, and the
2164 value the IA-64 "global pointer" register should have --- to
2165 support position-independent code. The linker generates
2166 descriptors only for those functions whose addresses are taken.
2168 On such targets, it's difficult for GDB to convert an arbitrary
2169 function address into a function pointer; it has to either find
2170 an existing descriptor for that function, or call malloc and
2171 build its own. On some targets, it is impossible for GDB to
2172 build a descriptor at all: the descriptor must contain a jump
2173 instruction; data memory cannot be executed; and code memory
2176 Upon entry to this function, if VAL is a value of type `function'
2177 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2178 value_address (val) is the address of the function. This is what
2179 you'll get if you evaluate an expression like `main'. The call
2180 to COERCE_ARRAY below actually does all the usual unary
2181 conversions, which includes converting values of type `function'
2182 to `pointer to function'. This is the challenging conversion
2183 discussed above. Then, `unpack_long' will convert that pointer
2184 back into an address.
2186 So, suppose the user types `disassemble foo' on an architecture
2187 with a strange function pointer representation, on which GDB
2188 cannot build its own descriptors, and suppose further that `foo'
2189 has no linker-built descriptor. The address->pointer conversion
2190 will signal an error and prevent the command from running, even
2191 though the next step would have been to convert the pointer
2192 directly back into the same address.
2194 The following shortcut avoids this whole mess. If VAL is a
2195 function, just return its address directly. */
2196 if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
2197 || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
2198 return value_address (val);
2200 val = coerce_array (val);
2202 /* Some architectures (e.g. Harvard), map instruction and data
2203 addresses onto a single large unified address space. For
2204 instance: An architecture may consider a large integer in the
2205 range 0x10000000 .. 0x1000ffff to already represent a data
2206 addresses (hence not need a pointer to address conversion) while
2207 a small integer would still need to be converted integer to
2208 pointer to address. Just assume such architectures handle all
2209 integer conversions in a single function. */
2213 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2214 must admonish GDB hackers to make sure its behavior matches the
2215 compiler's, whenever possible.
2217 In general, I think GDB should evaluate expressions the same way
2218 the compiler does. When the user copies an expression out of
2219 their source code and hands it to a `print' command, they should
2220 get the same value the compiler would have computed. Any
2221 deviation from this rule can cause major confusion and annoyance,
2222 and needs to be justified carefully. In other words, GDB doesn't
2223 really have the freedom to do these conversions in clever and
2226 AndrewC pointed out that users aren't complaining about how GDB
2227 casts integers to pointers; they are complaining that they can't
2228 take an address from a disassembly listing and give it to `x/i'.
2229 This is certainly important.
2231 Adding an architecture method like integer_to_address() certainly
2232 makes it possible for GDB to "get it right" in all circumstances
2233 --- the target has complete control over how things get done, so
2234 people can Do The Right Thing for their target without breaking
2235 anyone else. The standard doesn't specify how integers get
2236 converted to pointers; usually, the ABI doesn't either, but
2237 ABI-specific code is a more reasonable place to handle it. */
2239 if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
2240 && TYPE_CODE (value_type (val)) != TYPE_CODE_REF
2241 && gdbarch_integer_to_address_p (gdbarch))
2242 return gdbarch_integer_to_address (gdbarch, value_type (val),
2243 value_contents (val));
2245 return unpack_long (value_type (val), value_contents (val));
2249 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2250 as a long, or as a double, assuming the raw data is described
2251 by type TYPE. Knows how to convert different sizes of values
2252 and can convert between fixed and floating point. We don't assume
2253 any alignment for the raw data. Return value is in host byte order.
2255 If you want functions and arrays to be coerced to pointers, and
2256 references to be dereferenced, call value_as_long() instead.
2258 C++: It is assumed that the front-end has taken care of
2259 all matters concerning pointers to members. A pointer
2260 to member which reaches here is considered to be equivalent
2261 to an INT (or some size). After all, it is only an offset. */
2264 unpack_long (struct type *type, const gdb_byte *valaddr)
2266 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2267 enum type_code code = TYPE_CODE (type);
2268 int len = TYPE_LENGTH (type);
2269 int nosign = TYPE_UNSIGNED (type);
2273 case TYPE_CODE_TYPEDEF:
2274 return unpack_long (check_typedef (type), valaddr);
2275 case TYPE_CODE_ENUM:
2276 case TYPE_CODE_FLAGS:
2277 case TYPE_CODE_BOOL:
2279 case TYPE_CODE_CHAR:
2280 case TYPE_CODE_RANGE:
2281 case TYPE_CODE_MEMBERPTR:
2283 return extract_unsigned_integer (valaddr, len, byte_order);
2285 return extract_signed_integer (valaddr, len, byte_order);
2288 return extract_typed_floating (valaddr, type);
2290 case TYPE_CODE_DECFLOAT:
2291 /* libdecnumber has a function to convert from decimal to integer, but
2292 it doesn't work when the decimal number has a fractional part. */
2293 return decimal_to_doublest (valaddr, len, byte_order);
2297 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2298 whether we want this to be true eventually. */
2299 return extract_typed_address (valaddr, type);
2302 error (_("Value can't be converted to integer."));
2304 return 0; /* Placate lint. */
2307 /* Return a double value from the specified type and address.
2308 INVP points to an int which is set to 0 for valid value,
2309 1 for invalid value (bad float format). In either case,
2310 the returned double is OK to use. Argument is in target
2311 format, result is in host format. */
2314 unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
2316 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2317 enum type_code code;
2321 *invp = 0; /* Assume valid. */
2322 CHECK_TYPEDEF (type);
2323 code = TYPE_CODE (type);
2324 len = TYPE_LENGTH (type);
2325 nosign = TYPE_UNSIGNED (type);
2326 if (code == TYPE_CODE_FLT)
2328 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2329 floating-point value was valid (using the macro
2330 INVALID_FLOAT). That test/macro have been removed.
2332 It turns out that only the VAX defined this macro and then
2333 only in a non-portable way. Fixing the portability problem
2334 wouldn't help since the VAX floating-point code is also badly
2335 bit-rotten. The target needs to add definitions for the
2336 methods gdbarch_float_format and gdbarch_double_format - these
2337 exactly describe the target floating-point format. The
2338 problem here is that the corresponding floatformat_vax_f and
2339 floatformat_vax_d values these methods should be set to are
2340 also not defined either. Oops!
2342 Hopefully someone will add both the missing floatformat
2343 definitions and the new cases for floatformat_is_valid (). */
2345 if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
2351 return extract_typed_floating (valaddr, type);
2353 else if (code == TYPE_CODE_DECFLOAT)
2354 return decimal_to_doublest (valaddr, len, byte_order);
2357 /* Unsigned -- be sure we compensate for signed LONGEST. */
2358 return (ULONGEST) unpack_long (type, valaddr);
2362 /* Signed -- we are OK with unpack_long. */
2363 return unpack_long (type, valaddr);
2367 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2368 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2369 We don't assume any alignment for the raw data. Return value is in
2372 If you want functions and arrays to be coerced to pointers, and
2373 references to be dereferenced, call value_as_address() instead.
2375 C++: It is assumed that the front-end has taken care of
2376 all matters concerning pointers to members. A pointer
2377 to member which reaches here is considered to be equivalent
2378 to an INT (or some size). After all, it is only an offset. */
2381 unpack_pointer (struct type *type, const gdb_byte *valaddr)
2383 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2384 whether we want this to be true eventually. */
2385 return unpack_long (type, valaddr);
2389 /* Get the value of the FIELDNO'th field (which must be static) of
2390 TYPE. Return NULL if the field doesn't exist or has been
2394 value_static_field (struct type *type, int fieldno)
2396 struct value *retval;
2398 switch (TYPE_FIELD_LOC_KIND (type, fieldno))
2400 case FIELD_LOC_KIND_PHYSADDR:
2401 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2402 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
2404 case FIELD_LOC_KIND_PHYSNAME:
2406 const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
2407 /* TYPE_FIELD_NAME (type, fieldno); */
2408 struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
2412 /* With some compilers, e.g. HP aCC, static data members are
2413 reported as non-debuggable symbols. */
2414 struct minimal_symbol *msym = lookup_minimal_symbol (phys_name,
2421 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2422 SYMBOL_VALUE_ADDRESS (msym));
2426 retval = value_of_variable (sym, NULL);
2430 gdb_assert_not_reached ("unexpected field location kind");
2436 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2437 You have to be careful here, since the size of the data area for the value
2438 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2439 than the old enclosing type, you have to allocate more space for the
2443 set_value_enclosing_type (struct value *val, struct type *new_encl_type)
2445 if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
2447 (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
2449 val->enclosing_type = new_encl_type;
2452 /* Given a value ARG1 (offset by OFFSET bytes)
2453 of a struct or union type ARG_TYPE,
2454 extract and return the value of one of its (non-static) fields.
2455 FIELDNO says which field. */
2458 value_primitive_field (struct value *arg1, int offset,
2459 int fieldno, struct type *arg_type)
2464 CHECK_TYPEDEF (arg_type);
2465 type = TYPE_FIELD_TYPE (arg_type, fieldno);
2467 /* Call check_typedef on our type to make sure that, if TYPE
2468 is a TYPE_CODE_TYPEDEF, its length is set to the length
2469 of the target type instead of zero. However, we do not
2470 replace the typedef type by the target type, because we want
2471 to keep the typedef in order to be able to print the type
2472 description correctly. */
2473 check_typedef (type);
2475 /* Handle packed fields */
2477 if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
2479 /* Create a new value for the bitfield, with bitpos and bitsize
2480 set. If possible, arrange offset and bitpos so that we can
2481 do a single aligned read of the size of the containing type.
2482 Otherwise, adjust offset to the byte containing the first
2483 bit. Assume that the address, offset, and embedded offset
2484 are sufficiently aligned. */
2485 int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
2486 int container_bitsize = TYPE_LENGTH (type) * 8;
2488 v = allocate_value_lazy (type);
2489 v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
2490 if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
2491 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
2492 v->bitpos = bitpos % container_bitsize;
2494 v->bitpos = bitpos % 8;
2495 v->offset = (value_embedded_offset (arg1)
2497 + (bitpos - v->bitpos) / 8);
2499 value_incref (v->parent);
2500 if (!value_lazy (arg1))
2501 value_fetch_lazy (v);
2503 else if (fieldno < TYPE_N_BASECLASSES (arg_type))
2505 /* This field is actually a base subobject, so preserve the
2506 entire object's contents for later references to virtual
2509 /* Lazy register values with offsets are not supported. */
2510 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2511 value_fetch_lazy (arg1);
2513 if (value_lazy (arg1))
2514 v = allocate_value_lazy (value_enclosing_type (arg1));
2517 v = allocate_value (value_enclosing_type (arg1));
2518 value_contents_copy_raw (v, 0, arg1, 0,
2519 TYPE_LENGTH (value_enclosing_type (arg1)));
2522 v->offset = value_offset (arg1);
2523 v->embedded_offset = (offset + value_embedded_offset (arg1)
2524 + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8);
2528 /* Plain old data member */
2529 offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
2531 /* Lazy register values with offsets are not supported. */
2532 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2533 value_fetch_lazy (arg1);
2535 if (value_lazy (arg1))
2536 v = allocate_value_lazy (type);
2539 v = allocate_value (type);
2540 value_contents_copy_raw (v, value_embedded_offset (v),
2541 arg1, value_embedded_offset (arg1) + offset,
2542 TYPE_LENGTH (type));
2544 v->offset = (value_offset (arg1) + offset
2545 + value_embedded_offset (arg1));
2547 set_value_component_location (v, arg1);
2548 VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
2549 VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
2553 /* Given a value ARG1 of a struct or union type,
2554 extract and return the value of one of its (non-static) fields.
2555 FIELDNO says which field. */
2558 value_field (struct value *arg1, int fieldno)
2560 return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
2563 /* Return a non-virtual function as a value.
2564 F is the list of member functions which contains the desired method.
2565 J is an index into F which provides the desired method.
2567 We only use the symbol for its address, so be happy with either a
2568 full symbol or a minimal symbol. */
2571 value_fn_field (struct value **arg1p, struct fn_field *f,
2572 int j, struct type *type,
2576 struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
2577 const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
2579 struct minimal_symbol *msym;
2581 sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
2588 gdb_assert (sym == NULL);
2589 msym = lookup_minimal_symbol (physname, NULL, NULL);
2594 v = allocate_value (ftype);
2597 set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
2601 /* The minimal symbol might point to a function descriptor;
2602 resolve it to the actual code address instead. */
2603 struct objfile *objfile = msymbol_objfile (msym);
2604 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2606 set_value_address (v,
2607 gdbarch_convert_from_func_ptr_addr
2608 (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target));
2613 if (type != value_type (*arg1p))
2614 *arg1p = value_ind (value_cast (lookup_pointer_type (type),
2615 value_addr (*arg1p)));
2617 /* Move the `this' pointer according to the offset.
2618 VALUE_OFFSET (*arg1p) += offset; */
2626 /* Helper function for both unpack_value_bits_as_long and
2627 unpack_bits_as_long. See those functions for more details on the
2628 interface; the only difference is that this function accepts either
2629 a NULL or a non-NULL ORIGINAL_VALUE. */
2632 unpack_value_bits_as_long_1 (struct type *field_type, const gdb_byte *valaddr,
2633 int embedded_offset, int bitpos, int bitsize,
2634 const struct value *original_value,
2637 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
2644 /* Read the minimum number of bytes required; there may not be
2645 enough bytes to read an entire ULONGEST. */
2646 CHECK_TYPEDEF (field_type);
2648 bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
2650 bytes_read = TYPE_LENGTH (field_type);
2652 read_offset = bitpos / 8;
2654 if (original_value != NULL
2655 && !value_bytes_available (original_value, embedded_offset + read_offset,
2659 val = extract_unsigned_integer (valaddr + embedded_offset + read_offset,
2660 bytes_read, byte_order);
2662 /* Extract bits. See comment above. */
2664 if (gdbarch_bits_big_endian (get_type_arch (field_type)))
2665 lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
2667 lsbcount = (bitpos % 8);
2670 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2671 If the field is signed, and is negative, then sign extend. */
2673 if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
2675 valmask = (((ULONGEST) 1) << bitsize) - 1;
2677 if (!TYPE_UNSIGNED (field_type))
2679 if (val & (valmask ^ (valmask >> 1)))
2690 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2691 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2692 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2693 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2696 Returns false if the value contents are unavailable, otherwise
2697 returns true, indicating a valid value has been stored in *RESULT.
2699 Extracting bits depends on endianness of the machine. Compute the
2700 number of least significant bits to discard. For big endian machines,
2701 we compute the total number of bits in the anonymous object, subtract
2702 off the bit count from the MSB of the object to the MSB of the
2703 bitfield, then the size of the bitfield, which leaves the LSB discard
2704 count. For little endian machines, the discard count is simply the
2705 number of bits from the LSB of the anonymous object to the LSB of the
2708 If the field is signed, we also do sign extension. */
2711 unpack_value_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
2712 int embedded_offset, int bitpos, int bitsize,
2713 const struct value *original_value,
2716 gdb_assert (original_value != NULL);
2718 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2719 bitpos, bitsize, original_value, result);
2723 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2724 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2725 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2729 unpack_value_field_as_long_1 (struct type *type, const gdb_byte *valaddr,
2730 int embedded_offset, int fieldno,
2731 const struct value *val, LONGEST *result)
2733 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
2734 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
2735 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2737 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2738 bitpos, bitsize, val,
2742 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2743 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2744 ORIGINAL_VALUE, which must not be NULL. See
2745 unpack_value_bits_as_long for more details. */
2748 unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
2749 int embedded_offset, int fieldno,
2750 const struct value *val, LONGEST *result)
2752 gdb_assert (val != NULL);
2754 return unpack_value_field_as_long_1 (type, valaddr, embedded_offset,
2755 fieldno, val, result);
2758 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2759 object at VALADDR. See unpack_value_bits_as_long for more details.
2760 This function differs from unpack_value_field_as_long in that it
2761 operates without a struct value object. */
2764 unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
2768 unpack_value_field_as_long_1 (type, valaddr, 0, fieldno, NULL, &result);
2772 /* Return a new value with type TYPE, which is FIELDNO field of the
2773 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2774 of VAL. If the VAL's contents required to extract the bitfield
2775 from are unavailable, the new value is correspondingly marked as
2779 value_field_bitfield (struct type *type, int fieldno,
2780 const gdb_byte *valaddr,
2781 int embedded_offset, const struct value *val)
2785 if (!unpack_value_field_as_long (type, valaddr, embedded_offset, fieldno,
2788 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2789 struct value *retval = allocate_value (field_type);
2790 mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (field_type));
2795 return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), l);
2799 /* Modify the value of a bitfield. ADDR points to a block of memory in
2800 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2801 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2802 indicate which bits (in target bit order) comprise the bitfield.
2803 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2804 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2807 modify_field (struct type *type, gdb_byte *addr,
2808 LONGEST fieldval, int bitpos, int bitsize)
2810 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2812 ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
2815 /* Normalize BITPOS. */
2819 /* If a negative fieldval fits in the field in question, chop
2820 off the sign extension bits. */
2821 if ((~fieldval & ~(mask >> 1)) == 0)
2824 /* Warn if value is too big to fit in the field in question. */
2825 if (0 != (fieldval & ~mask))
2827 /* FIXME: would like to include fieldval in the message, but
2828 we don't have a sprintf_longest. */
2829 warning (_("Value does not fit in %d bits."), bitsize);
2831 /* Truncate it, otherwise adjoining fields may be corrupted. */
2835 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2836 false valgrind reports. */
2838 bytesize = (bitpos + bitsize + 7) / 8;
2839 oword = extract_unsigned_integer (addr, bytesize, byte_order);
2841 /* Shifting for bit field depends on endianness of the target machine. */
2842 if (gdbarch_bits_big_endian (get_type_arch (type)))
2843 bitpos = bytesize * 8 - bitpos - bitsize;
2845 oword &= ~(mask << bitpos);
2846 oword |= fieldval << bitpos;
2848 store_unsigned_integer (addr, bytesize, byte_order, oword);
2851 /* Pack NUM into BUF using a target format of TYPE. */
2854 pack_long (gdb_byte *buf, struct type *type, LONGEST num)
2856 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2859 type = check_typedef (type);
2860 len = TYPE_LENGTH (type);
2862 switch (TYPE_CODE (type))
2865 case TYPE_CODE_CHAR:
2866 case TYPE_CODE_ENUM:
2867 case TYPE_CODE_FLAGS:
2868 case TYPE_CODE_BOOL:
2869 case TYPE_CODE_RANGE:
2870 case TYPE_CODE_MEMBERPTR:
2871 store_signed_integer (buf, len, byte_order, num);
2876 store_typed_address (buf, type, (CORE_ADDR) num);
2880 error (_("Unexpected type (%d) encountered for integer constant."),
2886 /* Pack NUM into BUF using a target format of TYPE. */
2889 pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
2892 enum bfd_endian byte_order;
2894 type = check_typedef (type);
2895 len = TYPE_LENGTH (type);
2896 byte_order = gdbarch_byte_order (get_type_arch (type));
2898 switch (TYPE_CODE (type))
2901 case TYPE_CODE_CHAR:
2902 case TYPE_CODE_ENUM:
2903 case TYPE_CODE_FLAGS:
2904 case TYPE_CODE_BOOL:
2905 case TYPE_CODE_RANGE:
2906 case TYPE_CODE_MEMBERPTR:
2907 store_unsigned_integer (buf, len, byte_order, num);
2912 store_typed_address (buf, type, (CORE_ADDR) num);
2916 error (_("Unexpected type (%d) encountered "
2917 "for unsigned integer constant."),
2923 /* Convert C numbers into newly allocated values. */
2926 value_from_longest (struct type *type, LONGEST num)
2928 struct value *val = allocate_value (type);
2930 pack_long (value_contents_raw (val), type, num);
2935 /* Convert C unsigned numbers into newly allocated values. */
2938 value_from_ulongest (struct type *type, ULONGEST num)
2940 struct value *val = allocate_value (type);
2942 pack_unsigned_long (value_contents_raw (val), type, num);
2948 /* Create a value representing a pointer of type TYPE to the address
2951 value_from_pointer (struct type *type, CORE_ADDR addr)
2953 struct value *val = allocate_value (type);
2955 store_typed_address (value_contents_raw (val), check_typedef (type), addr);
2960 /* Create a value of type TYPE whose contents come from VALADDR, if it
2961 is non-null, and whose memory address (in the inferior) is
2965 value_from_contents_and_address (struct type *type,
2966 const gdb_byte *valaddr,
2971 if (valaddr == NULL)
2972 v = allocate_value_lazy (type);
2975 v = allocate_value (type);
2976 memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type));
2978 set_value_address (v, address);
2979 VALUE_LVAL (v) = lval_memory;
2983 /* Create a value of type TYPE holding the contents CONTENTS.
2984 The new value is `not_lval'. */
2987 value_from_contents (struct type *type, const gdb_byte *contents)
2989 struct value *result;
2991 result = allocate_value (type);
2992 memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type));
2997 value_from_double (struct type *type, DOUBLEST num)
2999 struct value *val = allocate_value (type);
3000 struct type *base_type = check_typedef (type);
3001 enum type_code code = TYPE_CODE (base_type);
3003 if (code == TYPE_CODE_FLT)
3005 store_typed_floating (value_contents_raw (val), base_type, num);
3008 error (_("Unexpected type encountered for floating constant."));
3014 value_from_decfloat (struct type *type, const gdb_byte *dec)
3016 struct value *val = allocate_value (type);
3018 memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
3022 /* Extract a value from the history file. Input will be of the form
3023 $digits or $$digits. See block comment above 'write_dollar_variable'
3027 value_from_history_ref (char *h, char **endp)
3039 /* Find length of numeral string. */
3040 for (; isdigit (h[len]); len++)
3043 /* Make sure numeral string is not part of an identifier. */
3044 if (h[len] == '_' || isalpha (h[len]))
3047 /* Now collect the index value. */
3052 /* For some bizarre reason, "$$" is equivalent to "$$1",
3053 rather than to "$$0" as it ought to be! */
3058 index = -strtol (&h[2], endp, 10);
3064 /* "$" is equivalent to "$0". */
3069 index = strtol (&h[1], endp, 10);
3072 return access_value_history (index);
3076 coerce_ref (struct value *arg)
3078 struct type *value_type_arg_tmp = check_typedef (value_type (arg));
3080 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)
3081 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),
3082 unpack_pointer (value_type (arg),
3083 value_contents (arg)));
3088 coerce_array (struct value *arg)
3092 arg = coerce_ref (arg);
3093 type = check_typedef (value_type (arg));
3095 switch (TYPE_CODE (type))
3097 case TYPE_CODE_ARRAY:
3098 if (!TYPE_VECTOR (type) && current_language->c_style_arrays)
3099 arg = value_coerce_array (arg);
3101 case TYPE_CODE_FUNC:
3102 arg = value_coerce_function (arg);
3109 /* Return true if the function returning the specified type is using
3110 the convention of returning structures in memory (passing in the
3111 address as a hidden first parameter). */
3114 using_struct_return (struct gdbarch *gdbarch,
3115 struct type *func_type, struct type *value_type)
3117 enum type_code code = TYPE_CODE (value_type);
3119 if (code == TYPE_CODE_ERROR)
3120 error (_("Function return type unknown."));
3122 if (code == TYPE_CODE_VOID)
3123 /* A void return value is never in memory. See also corresponding
3124 code in "print_return_value". */
3127 /* Probe the architecture for the return-value convention. */
3128 return (gdbarch_return_value (gdbarch, func_type, value_type,
3130 != RETURN_VALUE_REGISTER_CONVENTION);
3133 /* Set the initialized field in a value struct. */
3136 set_value_initialized (struct value *val, int status)
3138 val->initialized = status;
3141 /* Return the initialized field in a value struct. */
3144 value_initialized (struct value *val)
3146 return val->initialized;
3150 _initialize_values (void)
3152 add_cmd ("convenience", no_class, show_convenience, _("\
3153 Debugger convenience (\"$foo\") variables.\n\
3154 These variables are created when you assign them values;\n\
3155 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3157 A few convenience variables are given values automatically:\n\
3158 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3159 \"$__\" holds the contents of the last address examined with \"x\"."),
3162 add_cmd ("values", no_set_class, show_values, _("\
3163 Elements of value history around item number IDX (or last ten)."),
3166 add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
3167 Initialize a convenience variable if necessary.\n\
3168 init-if-undefined VARIABLE = EXPRESSION\n\
3169 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3170 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3171 VARIABLE is already initialized."));
3173 add_prefix_cmd ("function", no_class, function_command, _("\
3174 Placeholder command for showing help on convenience functions."),
3175 &functionlist, "function ", 0, &cmdlist);