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 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 value_entirely_available (struct value *value)
337 /* We can only tell whether the whole value is available when we try
340 value_fetch_lazy (value);
342 if (VEC_empty (range_s, value->unavailable))
348 mark_value_bytes_unavailable (struct value *value, int offset, int length)
353 /* Insert the range sorted. If there's overlap or the new range
354 would be contiguous with an existing range, merge. */
356 newr.offset = offset;
357 newr.length = length;
359 /* Do a binary search for the position the given range would be
360 inserted if we only considered the starting OFFSET of ranges.
361 Call that position I. Since we also have LENGTH to care for
362 (this is a range afterall), we need to check if the _previous_
363 range overlaps the I range. E.g., calling R the new range:
365 #1 - overlaps with previous
369 |---| |---| |------| ... |--|
374 In the case #1 above, the binary search would return `I=1',
375 meaning, this OFFSET should be inserted at position 1, and the
376 current position 1 should be pushed further (and become 2). But,
377 note that `0' overlaps with R, so we want to merge them.
379 A similar consideration needs to be taken if the new range would
380 be contiguous with the previous range:
382 #2 - contiguous with previous
386 |--| |---| |------| ... |--|
391 If there's no overlap with the previous range, as in:
393 #3 - not overlapping and not contiguous
397 |--| |---| |------| ... |--|
404 #4 - R is the range with lowest offset
408 |--| |---| |------| ... |--|
413 ... we just push the new range to I.
415 All the 4 cases above need to consider that the new range may
416 also overlap several of the ranges that follow, or that R may be
417 contiguous with the following range, and merge. E.g.,
419 #5 - overlapping following ranges
422 |------------------------|
423 |--| |---| |------| ... |--|
432 |--| |---| |------| ... |--|
439 i = VEC_lower_bound (range_s, value->unavailable, &newr, range_lessthan);
442 struct range *bef = VEC_index (range_s, value->unavailable, i - 1);
444 if (ranges_overlap (bef->offset, bef->length, offset, length))
447 ULONGEST l = min (bef->offset, offset);
448 ULONGEST h = max (bef->offset + bef->length, offset + length);
454 else if (offset == bef->offset + bef->length)
457 bef->length += length;
463 VEC_safe_insert (range_s, value->unavailable, i, &newr);
469 VEC_safe_insert (range_s, value->unavailable, i, &newr);
472 /* Check whether the ranges following the one we've just added or
473 touched can be folded in (#5 above). */
474 if (i + 1 < VEC_length (range_s, value->unavailable))
481 /* Get the range we just touched. */
482 t = VEC_index (range_s, value->unavailable, i);
486 for (; VEC_iterate (range_s, value->unavailable, i, r); i++)
487 if (r->offset <= t->offset + t->length)
491 l = min (t->offset, r->offset);
492 h = max (t->offset + t->length, r->offset + r->length);
501 /* If we couldn't merge this one, we won't be able to
502 merge following ones either, since the ranges are
503 always sorted by OFFSET. */
508 VEC_block_remove (range_s, value->unavailable, next, removed);
512 /* Find the first range in RANGES that overlaps the range defined by
513 OFFSET and LENGTH, starting at element POS in the RANGES vector,
514 Returns the index into RANGES where such overlapping range was
515 found, or -1 if none was found. */
518 find_first_range_overlap (VEC(range_s) *ranges, int pos,
519 int offset, int length)
524 for (i = pos; VEC_iterate (range_s, ranges, i, r); i++)
525 if (ranges_overlap (r->offset, r->length, offset, length))
532 value_available_contents_eq (const struct value *val1, int offset1,
533 const struct value *val2, int offset2,
536 int idx1 = 0, idx2 = 0;
538 /* This routine is used by printing routines, where we should
539 already have read the value. Note that we only know whether a
540 value chunk is available if we've tried to read it. */
541 gdb_assert (!val1->lazy && !val2->lazy);
549 idx1 = find_first_range_overlap (val1->unavailable, idx1,
551 idx2 = find_first_range_overlap (val2->unavailable, idx2,
554 /* The usual case is for both values to be completely available. */
555 if (idx1 == -1 && idx2 == -1)
556 return (memcmp (val1->contents + offset1,
557 val2->contents + offset2,
559 /* The contents only match equal if the available set matches as
561 else if (idx1 == -1 || idx2 == -1)
564 gdb_assert (idx1 != -1 && idx2 != -1);
566 r1 = VEC_index (range_s, val1->unavailable, idx1);
567 r2 = VEC_index (range_s, val2->unavailable, idx2);
569 /* Get the unavailable windows intersected by the incoming
570 ranges. The first and last ranges that overlap the argument
571 range may be wider than said incoming arguments ranges. */
572 l1 = max (offset1, r1->offset);
573 h1 = min (offset1 + length, r1->offset + r1->length);
575 l2 = max (offset2, r2->offset);
576 h2 = min (offset2 + length, r2->offset + r2->length);
578 /* Make them relative to the respective start offsets, so we can
579 compare them for equality. */
586 /* Different availability, no match. */
587 if (l1 != l2 || h1 != h2)
590 /* Compare the _available_ contents. */
591 if (memcmp (val1->contents + offset1,
592 val2->contents + offset2,
604 /* Prototypes for local functions. */
606 static void show_values (char *, int);
608 static void show_convenience (char *, int);
611 /* The value-history records all the values printed
612 by print commands during this session. Each chunk
613 records 60 consecutive values. The first chunk on
614 the chain records the most recent values.
615 The total number of values is in value_history_count. */
617 #define VALUE_HISTORY_CHUNK 60
619 struct value_history_chunk
621 struct value_history_chunk *next;
622 struct value *values[VALUE_HISTORY_CHUNK];
625 /* Chain of chunks now in use. */
627 static struct value_history_chunk *value_history_chain;
629 static int value_history_count; /* Abs number of last entry stored. */
632 /* List of all value objects currently allocated
633 (except for those released by calls to release_value)
634 This is so they can be freed after each command. */
636 static struct value *all_values;
638 /* Allocate a lazy value for type TYPE. Its actual content is
639 "lazily" allocated too: the content field of the return value is
640 NULL; it will be allocated when it is fetched from the target. */
643 allocate_value_lazy (struct type *type)
647 /* Call check_typedef on our type to make sure that, if TYPE
648 is a TYPE_CODE_TYPEDEF, its length is set to the length
649 of the target type instead of zero. However, we do not
650 replace the typedef type by the target type, because we want
651 to keep the typedef in order to be able to set the VAL's type
652 description correctly. */
653 check_typedef (type);
655 val = (struct value *) xzalloc (sizeof (struct value));
656 val->contents = NULL;
657 val->next = all_values;
660 val->enclosing_type = type;
661 VALUE_LVAL (val) = not_lval;
662 val->location.address = 0;
663 VALUE_FRAME_ID (val) = null_frame_id;
667 VALUE_REGNUM (val) = -1;
669 val->optimized_out = 0;
670 val->embedded_offset = 0;
671 val->pointed_to_offset = 0;
673 val->initialized = 1; /* Default to initialized. */
675 /* Values start out on the all_values chain. */
676 val->reference_count = 1;
681 /* Allocate the contents of VAL if it has not been allocated yet. */
684 allocate_value_contents (struct value *val)
687 val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
690 /* Allocate a value and its contents for type TYPE. */
693 allocate_value (struct type *type)
695 struct value *val = allocate_value_lazy (type);
697 allocate_value_contents (val);
702 /* Allocate a value that has the correct length
703 for COUNT repetitions of type TYPE. */
706 allocate_repeat_value (struct type *type, int count)
708 int low_bound = current_language->string_lower_bound; /* ??? */
709 /* FIXME-type-allocation: need a way to free this type when we are
711 struct type *array_type
712 = lookup_array_range_type (type, low_bound, count + low_bound - 1);
714 return allocate_value (array_type);
718 allocate_computed_value (struct type *type,
719 struct lval_funcs *funcs,
722 struct value *v = allocate_value_lazy (type);
724 VALUE_LVAL (v) = lval_computed;
725 v->location.computed.funcs = funcs;
726 v->location.computed.closure = closure;
731 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
734 allocate_optimized_out_value (struct type *type)
736 struct value *retval = allocate_value_lazy (type);
738 set_value_optimized_out (retval, 1);
743 /* Accessor methods. */
746 value_next (struct value *value)
752 value_type (const struct value *value)
757 deprecated_set_value_type (struct value *value, struct type *type)
763 value_offset (const struct value *value)
765 return value->offset;
768 set_value_offset (struct value *value, int offset)
770 value->offset = offset;
774 value_bitpos (const struct value *value)
776 return value->bitpos;
779 set_value_bitpos (struct value *value, int bit)
785 value_bitsize (const struct value *value)
787 return value->bitsize;
790 set_value_bitsize (struct value *value, int bit)
792 value->bitsize = bit;
796 value_parent (struct value *value)
798 return value->parent;
802 value_contents_raw (struct value *value)
804 allocate_value_contents (value);
805 return value->contents + value->embedded_offset;
809 value_contents_all_raw (struct value *value)
811 allocate_value_contents (value);
812 return value->contents;
816 value_enclosing_type (struct value *value)
818 return value->enclosing_type;
822 require_not_optimized_out (const struct value *value)
824 if (value->optimized_out)
825 error (_("value has been optimized out"));
829 require_available (const struct value *value)
831 if (!VEC_empty (range_s, value->unavailable))
832 throw_error (NOT_AVAILABLE_ERROR, _("value is not available"));
836 value_contents_for_printing (struct value *value)
839 value_fetch_lazy (value);
840 return value->contents;
844 value_contents_for_printing_const (const struct value *value)
846 gdb_assert (!value->lazy);
847 return value->contents;
851 value_contents_all (struct value *value)
853 const gdb_byte *result = value_contents_for_printing (value);
854 require_not_optimized_out (value);
855 require_available (value);
859 /* Copy LENGTH bytes of SRC value's (all) contents
860 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
861 contents, starting at DST_OFFSET. If unavailable contents are
862 being copied from SRC, the corresponding DST contents are marked
863 unavailable accordingly. Neither DST nor SRC may be lazy
866 It is assumed the contents of DST in the [DST_OFFSET,
867 DST_OFFSET+LENGTH) range are wholly available. */
870 value_contents_copy_raw (struct value *dst, int dst_offset,
871 struct value *src, int src_offset, int length)
876 /* A lazy DST would make that this copy operation useless, since as
877 soon as DST's contents were un-lazied (by a later value_contents
878 call, say), the contents would be overwritten. A lazy SRC would
879 mean we'd be copying garbage. */
880 gdb_assert (!dst->lazy && !src->lazy);
882 /* The overwritten DST range gets unavailability ORed in, not
883 replaced. Make sure to remember to implement replacing if it
884 turns out actually necessary. */
885 gdb_assert (value_bytes_available (dst, dst_offset, length));
888 memcpy (value_contents_all_raw (dst) + dst_offset,
889 value_contents_all_raw (src) + src_offset,
892 /* Copy the meta-data, adjusted. */
893 for (i = 0; VEC_iterate (range_s, src->unavailable, i, r); i++)
897 l = max (r->offset, src_offset);
898 h = min (r->offset + r->length, src_offset + length);
901 mark_value_bytes_unavailable (dst,
902 dst_offset + (l - src_offset),
907 /* Copy LENGTH bytes of SRC value's (all) contents
908 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
909 (all) contents, starting at DST_OFFSET. If unavailable contents
910 are being copied from SRC, the corresponding DST contents are
911 marked unavailable accordingly. DST must not be lazy. If SRC is
912 lazy, it will be fetched now. If SRC is not valid (is optimized
913 out), an error is thrown.
915 It is assumed the contents of DST in the [DST_OFFSET,
916 DST_OFFSET+LENGTH) range are wholly available. */
919 value_contents_copy (struct value *dst, int dst_offset,
920 struct value *src, int src_offset, int length)
922 require_not_optimized_out (src);
925 value_fetch_lazy (src);
927 value_contents_copy_raw (dst, dst_offset, src, src_offset, length);
931 value_lazy (struct value *value)
937 set_value_lazy (struct value *value, int val)
943 value_stack (struct value *value)
949 set_value_stack (struct value *value, int val)
955 value_contents (struct value *value)
957 const gdb_byte *result = value_contents_writeable (value);
958 require_not_optimized_out (value);
959 require_available (value);
964 value_contents_writeable (struct value *value)
967 value_fetch_lazy (value);
968 return value_contents_raw (value);
971 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
972 this function is different from value_equal; in C the operator ==
973 can return 0 even if the two values being compared are equal. */
976 value_contents_equal (struct value *val1, struct value *val2)
982 type1 = check_typedef (value_type (val1));
983 type2 = check_typedef (value_type (val2));
984 len = TYPE_LENGTH (type1);
985 if (len != TYPE_LENGTH (type2))
988 return (memcmp (value_contents (val1), value_contents (val2), len) == 0);
992 value_optimized_out (struct value *value)
994 return value->optimized_out;
998 set_value_optimized_out (struct value *value, int val)
1000 value->optimized_out = val;
1004 value_entirely_optimized_out (const struct value *value)
1006 if (!value->optimized_out)
1008 if (value->lval != lval_computed
1009 || !value->location.computed.funcs->check_any_valid)
1011 return !value->location.computed.funcs->check_any_valid (value);
1015 value_bits_valid (const struct value *value, int offset, int length)
1017 if (!value->optimized_out)
1019 if (value->lval != lval_computed
1020 || !value->location.computed.funcs->check_validity)
1022 return value->location.computed.funcs->check_validity (value, offset,
1027 value_bits_synthetic_pointer (const struct value *value,
1028 int offset, int length)
1030 if (value->lval != lval_computed
1031 || !value->location.computed.funcs->check_synthetic_pointer)
1033 return value->location.computed.funcs->check_synthetic_pointer (value,
1039 value_embedded_offset (struct value *value)
1041 return value->embedded_offset;
1045 set_value_embedded_offset (struct value *value, int val)
1047 value->embedded_offset = val;
1051 value_pointed_to_offset (struct value *value)
1053 return value->pointed_to_offset;
1057 set_value_pointed_to_offset (struct value *value, int val)
1059 value->pointed_to_offset = val;
1063 value_computed_funcs (struct value *v)
1065 gdb_assert (VALUE_LVAL (v) == lval_computed);
1067 return v->location.computed.funcs;
1071 value_computed_closure (const struct value *v)
1073 gdb_assert (v->lval == lval_computed);
1075 return v->location.computed.closure;
1079 deprecated_value_lval_hack (struct value *value)
1081 return &value->lval;
1085 value_address (const struct value *value)
1087 if (value->lval == lval_internalvar
1088 || value->lval == lval_internalvar_component)
1090 return value->location.address + value->offset;
1094 value_raw_address (struct value *value)
1096 if (value->lval == lval_internalvar
1097 || value->lval == lval_internalvar_component)
1099 return value->location.address;
1103 set_value_address (struct value *value, CORE_ADDR addr)
1105 gdb_assert (value->lval != lval_internalvar
1106 && value->lval != lval_internalvar_component);
1107 value->location.address = addr;
1110 struct internalvar **
1111 deprecated_value_internalvar_hack (struct value *value)
1113 return &value->location.internalvar;
1117 deprecated_value_frame_id_hack (struct value *value)
1119 return &value->frame_id;
1123 deprecated_value_regnum_hack (struct value *value)
1125 return &value->regnum;
1129 deprecated_value_modifiable (struct value *value)
1131 return value->modifiable;
1134 deprecated_set_value_modifiable (struct value *value, int modifiable)
1136 value->modifiable = modifiable;
1139 /* Return a mark in the value chain. All values allocated after the
1140 mark is obtained (except for those released) are subject to being freed
1141 if a subsequent value_free_to_mark is passed the mark. */
1148 /* Take a reference to VAL. VAL will not be deallocated until all
1149 references are released. */
1152 value_incref (struct value *val)
1154 val->reference_count++;
1157 /* Release a reference to VAL, which was acquired with value_incref.
1158 This function is also called to deallocate values from the value
1162 value_free (struct value *val)
1166 gdb_assert (val->reference_count > 0);
1167 val->reference_count--;
1168 if (val->reference_count > 0)
1171 /* If there's an associated parent value, drop our reference to
1173 if (val->parent != NULL)
1174 value_free (val->parent);
1176 if (VALUE_LVAL (val) == lval_computed)
1178 struct lval_funcs *funcs = val->location.computed.funcs;
1180 if (funcs->free_closure)
1181 funcs->free_closure (val);
1184 xfree (val->contents);
1185 VEC_free (range_s, val->unavailable);
1190 /* Free all values allocated since MARK was obtained by value_mark
1191 (except for those released). */
1193 value_free_to_mark (struct value *mark)
1198 for (val = all_values; val && val != mark; val = next)
1206 /* Free all the values that have been allocated (except for those released).
1207 Call after each command, successful or not.
1208 In practice this is called before each command, which is sufficient. */
1211 free_all_values (void)
1216 for (val = all_values; val; val = next)
1225 /* Frees all the elements in a chain of values. */
1228 free_value_chain (struct value *v)
1234 next = value_next (v);
1239 /* Remove VAL from the chain all_values
1240 so it will not be freed automatically. */
1243 release_value (struct value *val)
1247 if (all_values == val)
1249 all_values = val->next;
1254 for (v = all_values; v; v = v->next)
1258 v->next = val->next;
1265 /* Release all values up to mark */
1267 value_release_to_mark (struct value *mark)
1272 for (val = next = all_values; next; next = next->next)
1273 if (next->next == mark)
1275 all_values = next->next;
1283 /* Return a copy of the value ARG.
1284 It contains the same contents, for same memory address,
1285 but it's a different block of storage. */
1288 value_copy (struct value *arg)
1290 struct type *encl_type = value_enclosing_type (arg);
1293 if (value_lazy (arg))
1294 val = allocate_value_lazy (encl_type);
1296 val = allocate_value (encl_type);
1297 val->type = arg->type;
1298 VALUE_LVAL (val) = VALUE_LVAL (arg);
1299 val->location = arg->location;
1300 val->offset = arg->offset;
1301 val->bitpos = arg->bitpos;
1302 val->bitsize = arg->bitsize;
1303 VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
1304 VALUE_REGNUM (val) = VALUE_REGNUM (arg);
1305 val->lazy = arg->lazy;
1306 val->optimized_out = arg->optimized_out;
1307 val->embedded_offset = value_embedded_offset (arg);
1308 val->pointed_to_offset = arg->pointed_to_offset;
1309 val->modifiable = arg->modifiable;
1310 if (!value_lazy (val))
1312 memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
1313 TYPE_LENGTH (value_enclosing_type (arg)));
1316 val->unavailable = VEC_copy (range_s, arg->unavailable);
1317 val->parent = arg->parent;
1319 value_incref (val->parent);
1320 if (VALUE_LVAL (val) == lval_computed)
1322 struct lval_funcs *funcs = val->location.computed.funcs;
1324 if (funcs->copy_closure)
1325 val->location.computed.closure = funcs->copy_closure (val);
1330 /* Return a version of ARG that is non-lvalue. */
1333 value_non_lval (struct value *arg)
1335 if (VALUE_LVAL (arg) != not_lval)
1337 struct type *enc_type = value_enclosing_type (arg);
1338 struct value *val = allocate_value (enc_type);
1340 memcpy (value_contents_all_raw (val), value_contents_all (arg),
1341 TYPE_LENGTH (enc_type));
1342 val->type = arg->type;
1343 set_value_embedded_offset (val, value_embedded_offset (arg));
1344 set_value_pointed_to_offset (val, value_pointed_to_offset (arg));
1351 set_value_component_location (struct value *component,
1352 const struct value *whole)
1354 if (whole->lval == lval_internalvar)
1355 VALUE_LVAL (component) = lval_internalvar_component;
1357 VALUE_LVAL (component) = whole->lval;
1359 component->location = whole->location;
1360 if (whole->lval == lval_computed)
1362 struct lval_funcs *funcs = whole->location.computed.funcs;
1364 if (funcs->copy_closure)
1365 component->location.computed.closure = funcs->copy_closure (whole);
1370 /* Access to the value history. */
1372 /* Record a new value in the value history.
1373 Returns the absolute history index of the entry.
1374 Result of -1 indicates the value was not saved; otherwise it is the
1375 value history index of this new item. */
1378 record_latest_value (struct value *val)
1382 /* We don't want this value to have anything to do with the inferior anymore.
1383 In particular, "set $1 = 50" should not affect the variable from which
1384 the value was taken, and fast watchpoints should be able to assume that
1385 a value on the value history never changes. */
1386 if (value_lazy (val))
1387 value_fetch_lazy (val);
1388 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1389 from. This is a bit dubious, because then *&$1 does not just return $1
1390 but the current contents of that location. c'est la vie... */
1391 val->modifiable = 0;
1392 release_value (val);
1394 /* Here we treat value_history_count as origin-zero
1395 and applying to the value being stored now. */
1397 i = value_history_count % VALUE_HISTORY_CHUNK;
1400 struct value_history_chunk *new
1401 = (struct value_history_chunk *)
1403 xmalloc (sizeof (struct value_history_chunk));
1404 memset (new->values, 0, sizeof new->values);
1405 new->next = value_history_chain;
1406 value_history_chain = new;
1409 value_history_chain->values[i] = val;
1411 /* Now we regard value_history_count as origin-one
1412 and applying to the value just stored. */
1414 return ++value_history_count;
1417 /* Return a copy of the value in the history with sequence number NUM. */
1420 access_value_history (int num)
1422 struct value_history_chunk *chunk;
1427 absnum += value_history_count;
1432 error (_("The history is empty."));
1434 error (_("There is only one value in the history."));
1436 error (_("History does not go back to $$%d."), -num);
1438 if (absnum > value_history_count)
1439 error (_("History has not yet reached $%d."), absnum);
1443 /* Now absnum is always absolute and origin zero. */
1445 chunk = value_history_chain;
1446 for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK
1447 - absnum / VALUE_HISTORY_CHUNK;
1449 chunk = chunk->next;
1451 return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
1455 show_values (char *num_exp, int from_tty)
1463 /* "show values +" should print from the stored position.
1464 "show values <exp>" should print around value number <exp>. */
1465 if (num_exp[0] != '+' || num_exp[1] != '\0')
1466 num = parse_and_eval_long (num_exp) - 5;
1470 /* "show values" means print the last 10 values. */
1471 num = value_history_count - 9;
1477 for (i = num; i < num + 10 && i <= value_history_count; i++)
1479 struct value_print_options opts;
1481 val = access_value_history (i);
1482 printf_filtered (("$%d = "), i);
1483 get_user_print_options (&opts);
1484 value_print (val, gdb_stdout, &opts);
1485 printf_filtered (("\n"));
1488 /* The next "show values +" should start after what we just printed. */
1491 /* Hitting just return after this command should do the same thing as
1492 "show values +". If num_exp is null, this is unnecessary, since
1493 "show values +" is not useful after "show values". */
1494 if (from_tty && num_exp)
1501 /* Internal variables. These are variables within the debugger
1502 that hold values assigned by debugger commands.
1503 The user refers to them with a '$' prefix
1504 that does not appear in the variable names stored internally. */
1508 struct internalvar *next;
1511 /* We support various different kinds of content of an internal variable.
1512 enum internalvar_kind specifies the kind, and union internalvar_data
1513 provides the data associated with this particular kind. */
1515 enum internalvar_kind
1517 /* The internal variable is empty. */
1520 /* The value of the internal variable is provided directly as
1521 a GDB value object. */
1524 /* A fresh value is computed via a call-back routine on every
1525 access to the internal variable. */
1526 INTERNALVAR_MAKE_VALUE,
1528 /* The internal variable holds a GDB internal convenience function. */
1529 INTERNALVAR_FUNCTION,
1531 /* The variable holds an integer value. */
1532 INTERNALVAR_INTEGER,
1534 /* The variable holds a GDB-provided string. */
1539 union internalvar_data
1541 /* A value object used with INTERNALVAR_VALUE. */
1542 struct value *value;
1544 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1545 internalvar_make_value make_value;
1547 /* The internal function used with INTERNALVAR_FUNCTION. */
1550 struct internal_function *function;
1551 /* True if this is the canonical name for the function. */
1555 /* An integer value used with INTERNALVAR_INTEGER. */
1558 /* If type is non-NULL, it will be used as the type to generate
1559 a value for this internal variable. If type is NULL, a default
1560 integer type for the architecture is used. */
1565 /* A string value used with INTERNALVAR_STRING. */
1570 static struct internalvar *internalvars;
1572 /* If the variable does not already exist create it and give it the
1573 value given. If no value is given then the default is zero. */
1575 init_if_undefined_command (char* args, int from_tty)
1577 struct internalvar* intvar;
1579 /* Parse the expression - this is taken from set_command(). */
1580 struct expression *expr = parse_expression (args);
1581 register struct cleanup *old_chain =
1582 make_cleanup (free_current_contents, &expr);
1584 /* Validate the expression.
1585 Was the expression an assignment?
1586 Or even an expression at all? */
1587 if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
1588 error (_("Init-if-undefined requires an assignment expression."));
1590 /* Extract the variable from the parsed expression.
1591 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1592 if (expr->elts[1].opcode != OP_INTERNALVAR)
1593 error (_("The first parameter to init-if-undefined "
1594 "should be a GDB variable."));
1595 intvar = expr->elts[2].internalvar;
1597 /* Only evaluate the expression if the lvalue is void.
1598 This may still fail if the expresssion is invalid. */
1599 if (intvar->kind == INTERNALVAR_VOID)
1600 evaluate_expression (expr);
1602 do_cleanups (old_chain);
1606 /* Look up an internal variable with name NAME. NAME should not
1607 normally include a dollar sign.
1609 If the specified internal variable does not exist,
1610 the return value is NULL. */
1612 struct internalvar *
1613 lookup_only_internalvar (const char *name)
1615 struct internalvar *var;
1617 for (var = internalvars; var; var = var->next)
1618 if (strcmp (var->name, name) == 0)
1625 /* Create an internal variable with name NAME and with a void value.
1626 NAME should not normally include a dollar sign. */
1628 struct internalvar *
1629 create_internalvar (const char *name)
1631 struct internalvar *var;
1633 var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
1634 var->name = concat (name, (char *)NULL);
1635 var->kind = INTERNALVAR_VOID;
1636 var->next = internalvars;
1641 /* Create an internal variable with name NAME and register FUN as the
1642 function that value_of_internalvar uses to create a value whenever
1643 this variable is referenced. NAME should not normally include a
1646 struct internalvar *
1647 create_internalvar_type_lazy (char *name, internalvar_make_value fun)
1649 struct internalvar *var = create_internalvar (name);
1651 var->kind = INTERNALVAR_MAKE_VALUE;
1652 var->u.make_value = fun;
1656 /* Look up an internal variable with name NAME. NAME should not
1657 normally include a dollar sign.
1659 If the specified internal variable does not exist,
1660 one is created, with a void value. */
1662 struct internalvar *
1663 lookup_internalvar (const char *name)
1665 struct internalvar *var;
1667 var = lookup_only_internalvar (name);
1671 return create_internalvar (name);
1674 /* Return current value of internal variable VAR. For variables that
1675 are not inherently typed, use a value type appropriate for GDBARCH. */
1678 value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
1681 struct trace_state_variable *tsv;
1683 /* If there is a trace state variable of the same name, assume that
1684 is what we really want to see. */
1685 tsv = find_trace_state_variable (var->name);
1688 tsv->value_known = target_get_trace_state_variable_value (tsv->number,
1690 if (tsv->value_known)
1691 val = value_from_longest (builtin_type (gdbarch)->builtin_int64,
1694 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1700 case INTERNALVAR_VOID:
1701 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1704 case INTERNALVAR_FUNCTION:
1705 val = allocate_value (builtin_type (gdbarch)->internal_fn);
1708 case INTERNALVAR_INTEGER:
1709 if (!var->u.integer.type)
1710 val = value_from_longest (builtin_type (gdbarch)->builtin_int,
1711 var->u.integer.val);
1713 val = value_from_longest (var->u.integer.type, var->u.integer.val);
1716 case INTERNALVAR_STRING:
1717 val = value_cstring (var->u.string, strlen (var->u.string),
1718 builtin_type (gdbarch)->builtin_char);
1721 case INTERNALVAR_VALUE:
1722 val = value_copy (var->u.value);
1723 if (value_lazy (val))
1724 value_fetch_lazy (val);
1727 case INTERNALVAR_MAKE_VALUE:
1728 val = (*var->u.make_value) (gdbarch, var);
1732 internal_error (__FILE__, __LINE__, _("bad kind"));
1735 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1736 on this value go back to affect the original internal variable.
1738 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1739 no underlying modifyable state in the internal variable.
1741 Likewise, if the variable's value is a computed lvalue, we want
1742 references to it to produce another computed lvalue, where
1743 references and assignments actually operate through the
1744 computed value's functions.
1746 This means that internal variables with computed values
1747 behave a little differently from other internal variables:
1748 assignments to them don't just replace the previous value
1749 altogether. At the moment, this seems like the behavior we
1752 if (var->kind != INTERNALVAR_MAKE_VALUE
1753 && val->lval != lval_computed)
1755 VALUE_LVAL (val) = lval_internalvar;
1756 VALUE_INTERNALVAR (val) = var;
1763 get_internalvar_integer (struct internalvar *var, LONGEST *result)
1765 if (var->kind == INTERNALVAR_INTEGER)
1767 *result = var->u.integer.val;
1771 if (var->kind == INTERNALVAR_VALUE)
1773 struct type *type = check_typedef (value_type (var->u.value));
1775 if (TYPE_CODE (type) == TYPE_CODE_INT)
1777 *result = value_as_long (var->u.value);
1786 get_internalvar_function (struct internalvar *var,
1787 struct internal_function **result)
1791 case INTERNALVAR_FUNCTION:
1792 *result = var->u.fn.function;
1801 set_internalvar_component (struct internalvar *var, int offset, int bitpos,
1802 int bitsize, struct value *newval)
1808 case INTERNALVAR_VALUE:
1809 addr = value_contents_writeable (var->u.value);
1812 modify_field (value_type (var->u.value), addr + offset,
1813 value_as_long (newval), bitpos, bitsize);
1815 memcpy (addr + offset, value_contents (newval),
1816 TYPE_LENGTH (value_type (newval)));
1820 /* We can never get a component of any other kind. */
1821 internal_error (__FILE__, __LINE__, _("set_internalvar_component"));
1826 set_internalvar (struct internalvar *var, struct value *val)
1828 enum internalvar_kind new_kind;
1829 union internalvar_data new_data = { 0 };
1831 if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
1832 error (_("Cannot overwrite convenience function %s"), var->name);
1834 /* Prepare new contents. */
1835 switch (TYPE_CODE (check_typedef (value_type (val))))
1837 case TYPE_CODE_VOID:
1838 new_kind = INTERNALVAR_VOID;
1841 case TYPE_CODE_INTERNAL_FUNCTION:
1842 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1843 new_kind = INTERNALVAR_FUNCTION;
1844 get_internalvar_function (VALUE_INTERNALVAR (val),
1845 &new_data.fn.function);
1846 /* Copies created here are never canonical. */
1850 new_kind = INTERNALVAR_VALUE;
1851 new_data.value = value_copy (val);
1852 new_data.value->modifiable = 1;
1854 /* Force the value to be fetched from the target now, to avoid problems
1855 later when this internalvar is referenced and the target is gone or
1857 if (value_lazy (new_data.value))
1858 value_fetch_lazy (new_data.value);
1860 /* Release the value from the value chain to prevent it from being
1861 deleted by free_all_values. From here on this function should not
1862 call error () until new_data is installed into the var->u to avoid
1864 release_value (new_data.value);
1868 /* Clean up old contents. */
1869 clear_internalvar (var);
1872 var->kind = new_kind;
1874 /* End code which must not call error(). */
1878 set_internalvar_integer (struct internalvar *var, LONGEST l)
1880 /* Clean up old contents. */
1881 clear_internalvar (var);
1883 var->kind = INTERNALVAR_INTEGER;
1884 var->u.integer.type = NULL;
1885 var->u.integer.val = l;
1889 set_internalvar_string (struct internalvar *var, const char *string)
1891 /* Clean up old contents. */
1892 clear_internalvar (var);
1894 var->kind = INTERNALVAR_STRING;
1895 var->u.string = xstrdup (string);
1899 set_internalvar_function (struct internalvar *var, struct internal_function *f)
1901 /* Clean up old contents. */
1902 clear_internalvar (var);
1904 var->kind = INTERNALVAR_FUNCTION;
1905 var->u.fn.function = f;
1906 var->u.fn.canonical = 1;
1907 /* Variables installed here are always the canonical version. */
1911 clear_internalvar (struct internalvar *var)
1913 /* Clean up old contents. */
1916 case INTERNALVAR_VALUE:
1917 value_free (var->u.value);
1920 case INTERNALVAR_STRING:
1921 xfree (var->u.string);
1928 /* Reset to void kind. */
1929 var->kind = INTERNALVAR_VOID;
1933 internalvar_name (struct internalvar *var)
1938 static struct internal_function *
1939 create_internal_function (const char *name,
1940 internal_function_fn handler, void *cookie)
1942 struct internal_function *ifn = XNEW (struct internal_function);
1944 ifn->name = xstrdup (name);
1945 ifn->handler = handler;
1946 ifn->cookie = cookie;
1951 value_internal_function_name (struct value *val)
1953 struct internal_function *ifn;
1956 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1957 result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
1958 gdb_assert (result);
1964 call_internal_function (struct gdbarch *gdbarch,
1965 const struct language_defn *language,
1966 struct value *func, int argc, struct value **argv)
1968 struct internal_function *ifn;
1971 gdb_assert (VALUE_LVAL (func) == lval_internalvar);
1972 result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
1973 gdb_assert (result);
1975 return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
1978 /* The 'function' command. This does nothing -- it is just a
1979 placeholder to let "help function NAME" work. This is also used as
1980 the implementation of the sub-command that is created when
1981 registering an internal function. */
1983 function_command (char *command, int from_tty)
1988 /* Clean up if an internal function's command is destroyed. */
1990 function_destroyer (struct cmd_list_element *self, void *ignore)
1996 /* Add a new internal function. NAME is the name of the function; DOC
1997 is a documentation string describing the function. HANDLER is
1998 called when the function is invoked. COOKIE is an arbitrary
1999 pointer which is passed to HANDLER and is intended for "user
2002 add_internal_function (const char *name, const char *doc,
2003 internal_function_fn handler, void *cookie)
2005 struct cmd_list_element *cmd;
2006 struct internal_function *ifn;
2007 struct internalvar *var = lookup_internalvar (name);
2009 ifn = create_internal_function (name, handler, cookie);
2010 set_internalvar_function (var, ifn);
2012 cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
2014 cmd->destroyer = function_destroyer;
2017 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2018 prevent cycles / duplicates. */
2021 preserve_one_value (struct value *value, struct objfile *objfile,
2022 htab_t copied_types)
2024 if (TYPE_OBJFILE (value->type) == objfile)
2025 value->type = copy_type_recursive (objfile, value->type, copied_types);
2027 if (TYPE_OBJFILE (value->enclosing_type) == objfile)
2028 value->enclosing_type = copy_type_recursive (objfile,
2029 value->enclosing_type,
2033 /* Likewise for internal variable VAR. */
2036 preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
2037 htab_t copied_types)
2041 case INTERNALVAR_INTEGER:
2042 if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
2044 = copy_type_recursive (objfile, var->u.integer.type, copied_types);
2047 case INTERNALVAR_VALUE:
2048 preserve_one_value (var->u.value, objfile, copied_types);
2053 /* Update the internal variables and value history when OBJFILE is
2054 discarded; we must copy the types out of the objfile. New global types
2055 will be created for every convenience variable which currently points to
2056 this objfile's types, and the convenience variables will be adjusted to
2057 use the new global types. */
2060 preserve_values (struct objfile *objfile)
2062 htab_t copied_types;
2063 struct value_history_chunk *cur;
2064 struct internalvar *var;
2067 /* Create the hash table. We allocate on the objfile's obstack, since
2068 it is soon to be deleted. */
2069 copied_types = create_copied_types_hash (objfile);
2071 for (cur = value_history_chain; cur; cur = cur->next)
2072 for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
2074 preserve_one_value (cur->values[i], objfile, copied_types);
2076 for (var = internalvars; var; var = var->next)
2077 preserve_one_internalvar (var, objfile, copied_types);
2079 preserve_python_values (objfile, copied_types);
2081 htab_delete (copied_types);
2085 show_convenience (char *ignore, int from_tty)
2087 struct gdbarch *gdbarch = get_current_arch ();
2088 struct internalvar *var;
2090 struct value_print_options opts;
2092 get_user_print_options (&opts);
2093 for (var = internalvars; var; var = var->next)
2099 printf_filtered (("$%s = "), var->name);
2100 value_print (value_of_internalvar (gdbarch, var), gdb_stdout,
2102 printf_filtered (("\n"));
2105 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2106 "Convenience variables have "
2107 "names starting with \"$\";\n"
2108 "use \"set\" as in \"set "
2109 "$foo = 5\" to define them.\n"));
2112 /* Extract a value as a C number (either long or double).
2113 Knows how to convert fixed values to double, or
2114 floating values to long.
2115 Does not deallocate the value. */
2118 value_as_long (struct value *val)
2120 /* This coerces arrays and functions, which is necessary (e.g.
2121 in disassemble_command). It also dereferences references, which
2122 I suspect is the most logical thing to do. */
2123 val = coerce_array (val);
2124 return unpack_long (value_type (val), value_contents (val));
2128 value_as_double (struct value *val)
2133 foo = unpack_double (value_type (val), value_contents (val), &inv);
2135 error (_("Invalid floating value found in program."));
2139 /* Extract a value as a C pointer. Does not deallocate the value.
2140 Note that val's type may not actually be a pointer; value_as_long
2141 handles all the cases. */
2143 value_as_address (struct value *val)
2145 struct gdbarch *gdbarch = get_type_arch (value_type (val));
2147 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2148 whether we want this to be true eventually. */
2150 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2151 non-address (e.g. argument to "signal", "info break", etc.), or
2152 for pointers to char, in which the low bits *are* significant. */
2153 return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
2156 /* There are several targets (IA-64, PowerPC, and others) which
2157 don't represent pointers to functions as simply the address of
2158 the function's entry point. For example, on the IA-64, a
2159 function pointer points to a two-word descriptor, generated by
2160 the linker, which contains the function's entry point, and the
2161 value the IA-64 "global pointer" register should have --- to
2162 support position-independent code. The linker generates
2163 descriptors only for those functions whose addresses are taken.
2165 On such targets, it's difficult for GDB to convert an arbitrary
2166 function address into a function pointer; it has to either find
2167 an existing descriptor for that function, or call malloc and
2168 build its own. On some targets, it is impossible for GDB to
2169 build a descriptor at all: the descriptor must contain a jump
2170 instruction; data memory cannot be executed; and code memory
2173 Upon entry to this function, if VAL is a value of type `function'
2174 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2175 value_address (val) is the address of the function. This is what
2176 you'll get if you evaluate an expression like `main'. The call
2177 to COERCE_ARRAY below actually does all the usual unary
2178 conversions, which includes converting values of type `function'
2179 to `pointer to function'. This is the challenging conversion
2180 discussed above. Then, `unpack_long' will convert that pointer
2181 back into an address.
2183 So, suppose the user types `disassemble foo' on an architecture
2184 with a strange function pointer representation, on which GDB
2185 cannot build its own descriptors, and suppose further that `foo'
2186 has no linker-built descriptor. The address->pointer conversion
2187 will signal an error and prevent the command from running, even
2188 though the next step would have been to convert the pointer
2189 directly back into the same address.
2191 The following shortcut avoids this whole mess. If VAL is a
2192 function, just return its address directly. */
2193 if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
2194 || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
2195 return value_address (val);
2197 val = coerce_array (val);
2199 /* Some architectures (e.g. Harvard), map instruction and data
2200 addresses onto a single large unified address space. For
2201 instance: An architecture may consider a large integer in the
2202 range 0x10000000 .. 0x1000ffff to already represent a data
2203 addresses (hence not need a pointer to address conversion) while
2204 a small integer would still need to be converted integer to
2205 pointer to address. Just assume such architectures handle all
2206 integer conversions in a single function. */
2210 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2211 must admonish GDB hackers to make sure its behavior matches the
2212 compiler's, whenever possible.
2214 In general, I think GDB should evaluate expressions the same way
2215 the compiler does. When the user copies an expression out of
2216 their source code and hands it to a `print' command, they should
2217 get the same value the compiler would have computed. Any
2218 deviation from this rule can cause major confusion and annoyance,
2219 and needs to be justified carefully. In other words, GDB doesn't
2220 really have the freedom to do these conversions in clever and
2223 AndrewC pointed out that users aren't complaining about how GDB
2224 casts integers to pointers; they are complaining that they can't
2225 take an address from a disassembly listing and give it to `x/i'.
2226 This is certainly important.
2228 Adding an architecture method like integer_to_address() certainly
2229 makes it possible for GDB to "get it right" in all circumstances
2230 --- the target has complete control over how things get done, so
2231 people can Do The Right Thing for their target without breaking
2232 anyone else. The standard doesn't specify how integers get
2233 converted to pointers; usually, the ABI doesn't either, but
2234 ABI-specific code is a more reasonable place to handle it. */
2236 if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
2237 && TYPE_CODE (value_type (val)) != TYPE_CODE_REF
2238 && gdbarch_integer_to_address_p (gdbarch))
2239 return gdbarch_integer_to_address (gdbarch, value_type (val),
2240 value_contents (val));
2242 return unpack_long (value_type (val), value_contents (val));
2246 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2247 as a long, or as a double, assuming the raw data is described
2248 by type TYPE. Knows how to convert different sizes of values
2249 and can convert between fixed and floating point. We don't assume
2250 any alignment for the raw data. Return value is in host byte order.
2252 If you want functions and arrays to be coerced to pointers, and
2253 references to be dereferenced, call value_as_long() instead.
2255 C++: It is assumed that the front-end has taken care of
2256 all matters concerning pointers to members. A pointer
2257 to member which reaches here is considered to be equivalent
2258 to an INT (or some size). After all, it is only an offset. */
2261 unpack_long (struct type *type, const gdb_byte *valaddr)
2263 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2264 enum type_code code = TYPE_CODE (type);
2265 int len = TYPE_LENGTH (type);
2266 int nosign = TYPE_UNSIGNED (type);
2270 case TYPE_CODE_TYPEDEF:
2271 return unpack_long (check_typedef (type), valaddr);
2272 case TYPE_CODE_ENUM:
2273 case TYPE_CODE_FLAGS:
2274 case TYPE_CODE_BOOL:
2276 case TYPE_CODE_CHAR:
2277 case TYPE_CODE_RANGE:
2278 case TYPE_CODE_MEMBERPTR:
2280 return extract_unsigned_integer (valaddr, len, byte_order);
2282 return extract_signed_integer (valaddr, len, byte_order);
2285 return extract_typed_floating (valaddr, type);
2287 case TYPE_CODE_DECFLOAT:
2288 /* libdecnumber has a function to convert from decimal to integer, but
2289 it doesn't work when the decimal number has a fractional part. */
2290 return decimal_to_doublest (valaddr, len, byte_order);
2294 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2295 whether we want this to be true eventually. */
2296 return extract_typed_address (valaddr, type);
2299 error (_("Value can't be converted to integer."));
2301 return 0; /* Placate lint. */
2304 /* Return a double value from the specified type and address.
2305 INVP points to an int which is set to 0 for valid value,
2306 1 for invalid value (bad float format). In either case,
2307 the returned double is OK to use. Argument is in target
2308 format, result is in host format. */
2311 unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
2313 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2314 enum type_code code;
2318 *invp = 0; /* Assume valid. */
2319 CHECK_TYPEDEF (type);
2320 code = TYPE_CODE (type);
2321 len = TYPE_LENGTH (type);
2322 nosign = TYPE_UNSIGNED (type);
2323 if (code == TYPE_CODE_FLT)
2325 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2326 floating-point value was valid (using the macro
2327 INVALID_FLOAT). That test/macro have been removed.
2329 It turns out that only the VAX defined this macro and then
2330 only in a non-portable way. Fixing the portability problem
2331 wouldn't help since the VAX floating-point code is also badly
2332 bit-rotten. The target needs to add definitions for the
2333 methods gdbarch_float_format and gdbarch_double_format - these
2334 exactly describe the target floating-point format. The
2335 problem here is that the corresponding floatformat_vax_f and
2336 floatformat_vax_d values these methods should be set to are
2337 also not defined either. Oops!
2339 Hopefully someone will add both the missing floatformat
2340 definitions and the new cases for floatformat_is_valid (). */
2342 if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
2348 return extract_typed_floating (valaddr, type);
2350 else if (code == TYPE_CODE_DECFLOAT)
2351 return decimal_to_doublest (valaddr, len, byte_order);
2354 /* Unsigned -- be sure we compensate for signed LONGEST. */
2355 return (ULONGEST) unpack_long (type, valaddr);
2359 /* Signed -- we are OK with unpack_long. */
2360 return unpack_long (type, valaddr);
2364 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2365 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2366 We don't assume any alignment for the raw data. Return value is in
2369 If you want functions and arrays to be coerced to pointers, and
2370 references to be dereferenced, call value_as_address() instead.
2372 C++: It is assumed that the front-end has taken care of
2373 all matters concerning pointers to members. A pointer
2374 to member which reaches here is considered to be equivalent
2375 to an INT (or some size). After all, it is only an offset. */
2378 unpack_pointer (struct type *type, const gdb_byte *valaddr)
2380 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2381 whether we want this to be true eventually. */
2382 return unpack_long (type, valaddr);
2386 /* Get the value of the FIELDNO'th field (which must be static) of
2387 TYPE. Return NULL if the field doesn't exist or has been
2391 value_static_field (struct type *type, int fieldno)
2393 struct value *retval;
2395 switch (TYPE_FIELD_LOC_KIND (type, fieldno))
2397 case FIELD_LOC_KIND_PHYSADDR:
2398 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2399 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
2401 case FIELD_LOC_KIND_PHYSNAME:
2403 const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
2404 /* TYPE_FIELD_NAME (type, fieldno); */
2405 struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
2409 /* With some compilers, e.g. HP aCC, static data members are
2410 reported as non-debuggable symbols. */
2411 struct minimal_symbol *msym = lookup_minimal_symbol (phys_name,
2418 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2419 SYMBOL_VALUE_ADDRESS (msym));
2423 retval = value_of_variable (sym, NULL);
2427 gdb_assert_not_reached ("unexpected field location kind");
2433 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2434 You have to be careful here, since the size of the data area for the value
2435 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2436 than the old enclosing type, you have to allocate more space for the
2440 set_value_enclosing_type (struct value *val, struct type *new_encl_type)
2442 if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
2444 (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
2446 val->enclosing_type = new_encl_type;
2449 /* Given a value ARG1 (offset by OFFSET bytes)
2450 of a struct or union type ARG_TYPE,
2451 extract and return the value of one of its (non-static) fields.
2452 FIELDNO says which field. */
2455 value_primitive_field (struct value *arg1, int offset,
2456 int fieldno, struct type *arg_type)
2461 CHECK_TYPEDEF (arg_type);
2462 type = TYPE_FIELD_TYPE (arg_type, fieldno);
2464 /* Call check_typedef on our type to make sure that, if TYPE
2465 is a TYPE_CODE_TYPEDEF, its length is set to the length
2466 of the target type instead of zero. However, we do not
2467 replace the typedef type by the target type, because we want
2468 to keep the typedef in order to be able to print the type
2469 description correctly. */
2470 check_typedef (type);
2472 /* Handle packed fields */
2474 if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
2476 /* Create a new value for the bitfield, with bitpos and bitsize
2477 set. If possible, arrange offset and bitpos so that we can
2478 do a single aligned read of the size of the containing type.
2479 Otherwise, adjust offset to the byte containing the first
2480 bit. Assume that the address, offset, and embedded offset
2481 are sufficiently aligned. */
2482 int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
2483 int container_bitsize = TYPE_LENGTH (type) * 8;
2485 v = allocate_value_lazy (type);
2486 v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
2487 if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
2488 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
2489 v->bitpos = bitpos % container_bitsize;
2491 v->bitpos = bitpos % 8;
2492 v->offset = (value_embedded_offset (arg1)
2494 + (bitpos - v->bitpos) / 8);
2496 value_incref (v->parent);
2497 if (!value_lazy (arg1))
2498 value_fetch_lazy (v);
2500 else if (fieldno < TYPE_N_BASECLASSES (arg_type))
2502 /* This field is actually a base subobject, so preserve the
2503 entire object's contents for later references to virtual
2506 /* Lazy register values with offsets are not supported. */
2507 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2508 value_fetch_lazy (arg1);
2510 if (value_lazy (arg1))
2511 v = allocate_value_lazy (value_enclosing_type (arg1));
2514 v = allocate_value (value_enclosing_type (arg1));
2515 value_contents_copy_raw (v, 0, arg1, 0,
2516 TYPE_LENGTH (value_enclosing_type (arg1)));
2519 v->offset = value_offset (arg1);
2520 v->embedded_offset = (offset + value_embedded_offset (arg1)
2521 + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8);
2525 /* Plain old data member */
2526 offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
2528 /* Lazy register values with offsets are not supported. */
2529 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2530 value_fetch_lazy (arg1);
2532 if (value_lazy (arg1))
2533 v = allocate_value_lazy (type);
2536 v = allocate_value (type);
2537 value_contents_copy_raw (v, value_embedded_offset (v),
2538 arg1, value_embedded_offset (arg1) + offset,
2539 TYPE_LENGTH (type));
2541 v->offset = (value_offset (arg1) + offset
2542 + value_embedded_offset (arg1));
2544 set_value_component_location (v, arg1);
2545 VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
2546 VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
2550 /* Given a value ARG1 of a struct or union type,
2551 extract and return the value of one of its (non-static) fields.
2552 FIELDNO says which field. */
2555 value_field (struct value *arg1, int fieldno)
2557 return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
2560 /* Return a non-virtual function as a value.
2561 F is the list of member functions which contains the desired method.
2562 J is an index into F which provides the desired method.
2564 We only use the symbol for its address, so be happy with either a
2565 full symbol or a minimal symbol. */
2568 value_fn_field (struct value **arg1p, struct fn_field *f,
2569 int j, struct type *type,
2573 struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
2574 const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
2576 struct minimal_symbol *msym;
2578 sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
2585 gdb_assert (sym == NULL);
2586 msym = lookup_minimal_symbol (physname, NULL, NULL);
2591 v = allocate_value (ftype);
2594 set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
2598 /* The minimal symbol might point to a function descriptor;
2599 resolve it to the actual code address instead. */
2600 struct objfile *objfile = msymbol_objfile (msym);
2601 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2603 set_value_address (v,
2604 gdbarch_convert_from_func_ptr_addr
2605 (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target));
2610 if (type != value_type (*arg1p))
2611 *arg1p = value_ind (value_cast (lookup_pointer_type (type),
2612 value_addr (*arg1p)));
2614 /* Move the `this' pointer according to the offset.
2615 VALUE_OFFSET (*arg1p) += offset; */
2623 /* Helper function for both unpack_value_bits_as_long and
2624 unpack_bits_as_long. See those functions for more details on the
2625 interface; the only difference is that this function accepts either
2626 a NULL or a non-NULL ORIGINAL_VALUE. */
2629 unpack_value_bits_as_long_1 (struct type *field_type, const gdb_byte *valaddr,
2630 int embedded_offset, int bitpos, int bitsize,
2631 const struct value *original_value,
2634 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
2641 /* Read the minimum number of bytes required; there may not be
2642 enough bytes to read an entire ULONGEST. */
2643 CHECK_TYPEDEF (field_type);
2645 bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
2647 bytes_read = TYPE_LENGTH (field_type);
2649 read_offset = bitpos / 8;
2651 if (original_value != NULL
2652 && !value_bytes_available (original_value, embedded_offset + read_offset,
2656 val = extract_unsigned_integer (valaddr + embedded_offset + read_offset,
2657 bytes_read, byte_order);
2659 /* Extract bits. See comment above. */
2661 if (gdbarch_bits_big_endian (get_type_arch (field_type)))
2662 lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
2664 lsbcount = (bitpos % 8);
2667 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2668 If the field is signed, and is negative, then sign extend. */
2670 if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
2672 valmask = (((ULONGEST) 1) << bitsize) - 1;
2674 if (!TYPE_UNSIGNED (field_type))
2676 if (val & (valmask ^ (valmask >> 1)))
2687 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2688 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2689 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2690 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2693 Returns false if the value contents are unavailable, otherwise
2694 returns true, indicating a valid value has been stored in *RESULT.
2696 Extracting bits depends on endianness of the machine. Compute the
2697 number of least significant bits to discard. For big endian machines,
2698 we compute the total number of bits in the anonymous object, subtract
2699 off the bit count from the MSB of the object to the MSB of the
2700 bitfield, then the size of the bitfield, which leaves the LSB discard
2701 count. For little endian machines, the discard count is simply the
2702 number of bits from the LSB of the anonymous object to the LSB of the
2705 If the field is signed, we also do sign extension. */
2708 unpack_value_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
2709 int embedded_offset, int bitpos, int bitsize,
2710 const struct value *original_value,
2713 gdb_assert (original_value != NULL);
2715 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2716 bitpos, bitsize, original_value, result);
2720 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2721 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2722 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2726 unpack_value_field_as_long_1 (struct type *type, const gdb_byte *valaddr,
2727 int embedded_offset, int fieldno,
2728 const struct value *val, LONGEST *result)
2730 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
2731 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
2732 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2734 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2735 bitpos, bitsize, val,
2739 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2740 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2741 ORIGINAL_VALUE, which must not be NULL. See
2742 unpack_value_bits_as_long for more details. */
2745 unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
2746 int embedded_offset, int fieldno,
2747 const struct value *val, LONGEST *result)
2749 gdb_assert (val != NULL);
2751 return unpack_value_field_as_long_1 (type, valaddr, embedded_offset,
2752 fieldno, val, result);
2755 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2756 object at VALADDR. See unpack_value_bits_as_long for more details.
2757 This function differs from unpack_value_field_as_long in that it
2758 operates without a struct value object. */
2761 unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
2765 unpack_value_field_as_long_1 (type, valaddr, 0, fieldno, NULL, &result);
2769 /* Return a new value with type TYPE, which is FIELDNO field of the
2770 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2771 of VAL. If the VAL's contents required to extract the bitfield
2772 from are unavailable, the new value is correspondingly marked as
2776 value_field_bitfield (struct type *type, int fieldno,
2777 const gdb_byte *valaddr,
2778 int embedded_offset, const struct value *val)
2782 if (!unpack_value_field_as_long (type, valaddr, embedded_offset, fieldno,
2785 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2786 struct value *retval = allocate_value (field_type);
2787 mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (field_type));
2792 return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), l);
2796 /* Modify the value of a bitfield. ADDR points to a block of memory in
2797 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2798 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2799 indicate which bits (in target bit order) comprise the bitfield.
2800 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2801 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2804 modify_field (struct type *type, gdb_byte *addr,
2805 LONGEST fieldval, int bitpos, int bitsize)
2807 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2809 ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
2812 /* Normalize BITPOS. */
2816 /* If a negative fieldval fits in the field in question, chop
2817 off the sign extension bits. */
2818 if ((~fieldval & ~(mask >> 1)) == 0)
2821 /* Warn if value is too big to fit in the field in question. */
2822 if (0 != (fieldval & ~mask))
2824 /* FIXME: would like to include fieldval in the message, but
2825 we don't have a sprintf_longest. */
2826 warning (_("Value does not fit in %d bits."), bitsize);
2828 /* Truncate it, otherwise adjoining fields may be corrupted. */
2832 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2833 false valgrind reports. */
2835 bytesize = (bitpos + bitsize + 7) / 8;
2836 oword = extract_unsigned_integer (addr, bytesize, byte_order);
2838 /* Shifting for bit field depends on endianness of the target machine. */
2839 if (gdbarch_bits_big_endian (get_type_arch (type)))
2840 bitpos = bytesize * 8 - bitpos - bitsize;
2842 oword &= ~(mask << bitpos);
2843 oword |= fieldval << bitpos;
2845 store_unsigned_integer (addr, bytesize, byte_order, oword);
2848 /* Pack NUM into BUF using a target format of TYPE. */
2851 pack_long (gdb_byte *buf, struct type *type, LONGEST num)
2853 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2856 type = check_typedef (type);
2857 len = TYPE_LENGTH (type);
2859 switch (TYPE_CODE (type))
2862 case TYPE_CODE_CHAR:
2863 case TYPE_CODE_ENUM:
2864 case TYPE_CODE_FLAGS:
2865 case TYPE_CODE_BOOL:
2866 case TYPE_CODE_RANGE:
2867 case TYPE_CODE_MEMBERPTR:
2868 store_signed_integer (buf, len, byte_order, num);
2873 store_typed_address (buf, type, (CORE_ADDR) num);
2877 error (_("Unexpected type (%d) encountered for integer constant."),
2883 /* Pack NUM into BUF using a target format of TYPE. */
2886 pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
2889 enum bfd_endian byte_order;
2891 type = check_typedef (type);
2892 len = TYPE_LENGTH (type);
2893 byte_order = gdbarch_byte_order (get_type_arch (type));
2895 switch (TYPE_CODE (type))
2898 case TYPE_CODE_CHAR:
2899 case TYPE_CODE_ENUM:
2900 case TYPE_CODE_FLAGS:
2901 case TYPE_CODE_BOOL:
2902 case TYPE_CODE_RANGE:
2903 case TYPE_CODE_MEMBERPTR:
2904 store_unsigned_integer (buf, len, byte_order, num);
2909 store_typed_address (buf, type, (CORE_ADDR) num);
2913 error (_("Unexpected type (%d) encountered "
2914 "for unsigned integer constant."),
2920 /* Convert C numbers into newly allocated values. */
2923 value_from_longest (struct type *type, LONGEST num)
2925 struct value *val = allocate_value (type);
2927 pack_long (value_contents_raw (val), type, num);
2932 /* Convert C unsigned numbers into newly allocated values. */
2935 value_from_ulongest (struct type *type, ULONGEST num)
2937 struct value *val = allocate_value (type);
2939 pack_unsigned_long (value_contents_raw (val), type, num);
2945 /* Create a value representing a pointer of type TYPE to the address
2948 value_from_pointer (struct type *type, CORE_ADDR addr)
2950 struct value *val = allocate_value (type);
2952 store_typed_address (value_contents_raw (val), check_typedef (type), addr);
2957 /* Create a value of type TYPE whose contents come from VALADDR, if it
2958 is non-null, and whose memory address (in the inferior) is
2962 value_from_contents_and_address (struct type *type,
2963 const gdb_byte *valaddr,
2968 if (valaddr == NULL)
2969 v = allocate_value_lazy (type);
2972 v = allocate_value (type);
2973 memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type));
2975 set_value_address (v, address);
2976 VALUE_LVAL (v) = lval_memory;
2980 /* Create a value of type TYPE holding the contents CONTENTS.
2981 The new value is `not_lval'. */
2984 value_from_contents (struct type *type, const gdb_byte *contents)
2986 struct value *result;
2988 result = allocate_value (type);
2989 memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type));
2994 value_from_double (struct type *type, DOUBLEST num)
2996 struct value *val = allocate_value (type);
2997 struct type *base_type = check_typedef (type);
2998 enum type_code code = TYPE_CODE (base_type);
3000 if (code == TYPE_CODE_FLT)
3002 store_typed_floating (value_contents_raw (val), base_type, num);
3005 error (_("Unexpected type encountered for floating constant."));
3011 value_from_decfloat (struct type *type, const gdb_byte *dec)
3013 struct value *val = allocate_value (type);
3015 memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
3019 /* Extract a value from the history file. Input will be of the form
3020 $digits or $$digits. See block comment above 'write_dollar_variable'
3024 value_from_history_ref (char *h, char **endp)
3036 /* Find length of numeral string. */
3037 for (; isdigit (h[len]); len++)
3040 /* Make sure numeral string is not part of an identifier. */
3041 if (h[len] == '_' || isalpha (h[len]))
3044 /* Now collect the index value. */
3049 /* For some bizarre reason, "$$" is equivalent to "$$1",
3050 rather than to "$$0" as it ought to be! */
3055 index = -strtol (&h[2], endp, 10);
3061 /* "$" is equivalent to "$0". */
3066 index = strtol (&h[1], endp, 10);
3069 return access_value_history (index);
3073 coerce_ref (struct value *arg)
3075 struct type *value_type_arg_tmp = check_typedef (value_type (arg));
3077 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)
3078 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),
3079 unpack_pointer (value_type (arg),
3080 value_contents (arg)));
3085 coerce_array (struct value *arg)
3089 arg = coerce_ref (arg);
3090 type = check_typedef (value_type (arg));
3092 switch (TYPE_CODE (type))
3094 case TYPE_CODE_ARRAY:
3095 if (!TYPE_VECTOR (type) && current_language->c_style_arrays)
3096 arg = value_coerce_array (arg);
3098 case TYPE_CODE_FUNC:
3099 arg = value_coerce_function (arg);
3106 /* Return true if the function returning the specified type is using
3107 the convention of returning structures in memory (passing in the
3108 address as a hidden first parameter). */
3111 using_struct_return (struct gdbarch *gdbarch,
3112 struct type *func_type, struct type *value_type)
3114 enum type_code code = TYPE_CODE (value_type);
3116 if (code == TYPE_CODE_ERROR)
3117 error (_("Function return type unknown."));
3119 if (code == TYPE_CODE_VOID)
3120 /* A void return value is never in memory. See also corresponding
3121 code in "print_return_value". */
3124 /* Probe the architecture for the return-value convention. */
3125 return (gdbarch_return_value (gdbarch, func_type, value_type,
3127 != RETURN_VALUE_REGISTER_CONVENTION);
3130 /* Set the initialized field in a value struct. */
3133 set_value_initialized (struct value *val, int status)
3135 val->initialized = status;
3138 /* Return the initialized field in a value struct. */
3141 value_initialized (struct value *val)
3143 return val->initialized;
3147 _initialize_values (void)
3149 add_cmd ("convenience", no_class, show_convenience, _("\
3150 Debugger convenience (\"$foo\") variables.\n\
3151 These variables are created when you assign them values;\n\
3152 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3154 A few convenience variables are given values automatically:\n\
3155 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3156 \"$__\" holds the contents of the last address examined with \"x\"."),
3159 add_cmd ("values", no_set_class, show_values, _("\
3160 Elements of value history around item number IDX (or last ten)."),
3163 add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
3164 Initialize a convenience variable if necessary.\n\
3165 init-if-undefined VARIABLE = EXPRESSION\n\
3166 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3167 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3168 VARIABLE is already initialized."));
3170 add_prefix_cmd ("function", no_class, function_command, _("\
3171 Placeholder command for showing help on convenience functions."),
3172 &functionlist, "function ", 0, &cmdlist);