1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2000, 2002-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
22 #include "gdb_string.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
45 /* Prototypes for exported functions. */
47 void _initialize_values (void);
49 /* Definition of a user function. */
50 struct internal_function
52 /* The name of the function. It is a bit odd to have this in the
53 function itself -- the user might use a differently-named
54 convenience variable to hold the function. */
58 internal_function_fn handler;
60 /* User data for the handler. */
64 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
68 /* Lowest offset in the range. */
71 /* Length of the range. */
75 typedef struct range range_s;
79 /* Returns true if the ranges defined by [offset1, offset1+len1) and
80 [offset2, offset2+len2) overlap. */
83 ranges_overlap (int offset1, int len1,
84 int offset2, int len2)
88 l = max (offset1, offset2);
89 h = min (offset1 + len1, offset2 + len2);
93 /* Returns true if the first argument is strictly less than the
94 second, useful for VEC_lower_bound. We keep ranges sorted by
95 offset and coalesce overlapping and contiguous ranges, so this just
96 compares the starting offset. */
99 range_lessthan (const range_s *r1, const range_s *r2)
101 return r1->offset < r2->offset;
104 /* Returns true if RANGES contains any range that overlaps [OFFSET,
108 ranges_contain (VEC(range_s) *ranges, int offset, int length)
113 what.offset = offset;
114 what.length = length;
116 /* We keep ranges sorted by offset and coalesce overlapping and
117 contiguous ranges, so to check if a range list contains a given
118 range, we can do a binary search for the position the given range
119 would be inserted if we only considered the starting OFFSET of
120 ranges. We call that position I. Since we also have LENGTH to
121 care for (this is a range afterall), we need to check if the
122 _previous_ range overlaps the I range. E.g.,
126 |---| |---| |------| ... |--|
131 In the case above, the binary search would return `I=1', meaning,
132 this OFFSET should be inserted at position 1, and the current
133 position 1 should be pushed further (and before 2). But, `0'
136 Then we need to check if the I range overlaps the I range itself.
141 |---| |---| |-------| ... |--|
147 i = VEC_lower_bound (range_s, ranges, &what, range_lessthan);
151 struct range *bef = VEC_index (range_s, ranges, i - 1);
153 if (ranges_overlap (bef->offset, bef->length, offset, length))
157 if (i < VEC_length (range_s, ranges))
159 struct range *r = VEC_index (range_s, ranges, i);
161 if (ranges_overlap (r->offset, r->length, offset, length))
168 static struct cmd_list_element *functionlist;
172 /* Type of value; either not an lval, or one of the various
173 different possible kinds of lval. */
176 /* Is it modifiable? Only relevant if lval != not_lval. */
179 /* Location of value (if lval). */
182 /* If lval == lval_memory, this is the address in the inferior.
183 If lval == lval_register, this is the byte offset into the
184 registers structure. */
187 /* Pointer to internal variable. */
188 struct internalvar *internalvar;
190 /* If lval == lval_computed, this is a set of function pointers
191 to use to access and describe the value, and a closure pointer
195 /* Functions to call. */
196 const struct lval_funcs *funcs;
198 /* Closure for those functions to use. */
203 /* Describes offset of a value within lval of a structure in bytes.
204 If lval == lval_memory, this is an offset to the address. If
205 lval == lval_register, this is a further offset from
206 location.address within the registers structure. Note also the
207 member embedded_offset below. */
210 /* Only used for bitfields; number of bits contained in them. */
213 /* Only used for bitfields; position of start of field. For
214 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
215 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
218 /* Only used for bitfields; the containing value. This allows a
219 single read from the target when displaying multiple
221 struct value *parent;
223 /* Frame register value is relative to. This will be described in
224 the lval enum above as "lval_register". */
225 struct frame_id frame_id;
227 /* Type of the value. */
230 /* If a value represents a C++ object, then the `type' field gives
231 the object's compile-time type. If the object actually belongs
232 to some class derived from `type', perhaps with other base
233 classes and additional members, then `type' is just a subobject
234 of the real thing, and the full object is probably larger than
235 `type' would suggest.
237 If `type' is a dynamic class (i.e. one with a vtable), then GDB
238 can actually determine the object's run-time type by looking at
239 the run-time type information in the vtable. When this
240 information is available, we may elect to read in the entire
241 object, for several reasons:
243 - When printing the value, the user would probably rather see the
244 full object, not just the limited portion apparent from the
247 - If `type' has virtual base classes, then even printing `type'
248 alone may require reaching outside the `type' portion of the
249 object to wherever the virtual base class has been stored.
251 When we store the entire object, `enclosing_type' is the run-time
252 type -- the complete object -- and `embedded_offset' is the
253 offset of `type' within that larger type, in bytes. The
254 value_contents() macro takes `embedded_offset' into account, so
255 most GDB code continues to see the `type' portion of the value,
256 just as the inferior would.
258 If `type' is a pointer to an object, then `enclosing_type' is a
259 pointer to the object's run-time type, and `pointed_to_offset' is
260 the offset in bytes from the full object to the pointed-to object
261 -- that is, the value `embedded_offset' would have if we followed
262 the pointer and fetched the complete object. (I don't really see
263 the point. Why not just determine the run-time type when you
264 indirect, and avoid the special case? The contents don't matter
265 until you indirect anyway.)
267 If we're not doing anything fancy, `enclosing_type' is equal to
268 `type', and `embedded_offset' is zero, so everything works
270 struct type *enclosing_type;
272 int pointed_to_offset;
274 /* Values are stored in a chain, so that they can be deleted easily
275 over calls to the inferior. Values assigned to internal
276 variables, put into the value history or exposed to Python are
277 taken off this list. */
280 /* Register number if the value is from a register. */
283 /* If zero, contents of this value are in the contents field. If
284 nonzero, contents are in inferior. If the lval field is lval_memory,
285 the contents are in inferior memory at location.address plus offset.
286 The lval field may also be lval_register.
288 WARNING: This field is used by the code which handles watchpoints
289 (see breakpoint.c) to decide whether a particular value can be
290 watched by hardware watchpoints. If the lazy flag is set for
291 some member of a value chain, it is assumed that this member of
292 the chain doesn't need to be watched as part of watching the
293 value itself. This is how GDB avoids watching the entire struct
294 or array when the user wants to watch a single struct member or
295 array element. If you ever change the way lazy flag is set and
296 reset, be sure to consider this use as well! */
299 /* If nonzero, this is the value of a variable which does not
300 actually exist in the program. */
303 /* If value is a variable, is it initialized or not. */
306 /* If value is from the stack. If this is set, read_stack will be
307 used instead of read_memory to enable extra caching. */
310 /* Actual contents of the value. Target byte-order. NULL or not
311 valid if lazy is nonzero. */
314 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
315 rather than available, since the common and default case is for a
316 value to be available. This is filled in at value read time. */
317 VEC(range_s) *unavailable;
319 /* The number of references to this value. When a value is created,
320 the value chain holds a reference, so REFERENCE_COUNT is 1. If
321 release_value is called, this value is removed from the chain but
322 the caller of release_value now has a reference to this value.
323 The caller must arrange for a call to value_free later. */
328 value_bytes_available (const struct value *value, int offset, int length)
330 gdb_assert (!value->lazy);
332 return !ranges_contain (value->unavailable, offset, length);
336 value_entirely_available (struct value *value)
338 /* We can only tell whether the whole value is available when we try
341 value_fetch_lazy (value);
343 if (VEC_empty (range_s, value->unavailable))
349 mark_value_bytes_unavailable (struct value *value, int offset, int length)
354 /* Insert the range sorted. If there's overlap or the new range
355 would be contiguous with an existing range, merge. */
357 newr.offset = offset;
358 newr.length = length;
360 /* Do a binary search for the position the given range would be
361 inserted if we only considered the starting OFFSET of ranges.
362 Call that position I. Since we also have LENGTH to care for
363 (this is a range afterall), we need to check if the _previous_
364 range overlaps the I range. E.g., calling R the new range:
366 #1 - overlaps with previous
370 |---| |---| |------| ... |--|
375 In the case #1 above, the binary search would return `I=1',
376 meaning, this OFFSET should be inserted at position 1, and the
377 current position 1 should be pushed further (and become 2). But,
378 note that `0' overlaps with R, so we want to merge them.
380 A similar consideration needs to be taken if the new range would
381 be contiguous with the previous range:
383 #2 - contiguous with previous
387 |--| |---| |------| ... |--|
392 If there's no overlap with the previous range, as in:
394 #3 - not overlapping and not contiguous
398 |--| |---| |------| ... |--|
405 #4 - R is the range with lowest offset
409 |--| |---| |------| ... |--|
414 ... we just push the new range to I.
416 All the 4 cases above need to consider that the new range may
417 also overlap several of the ranges that follow, or that R may be
418 contiguous with the following range, and merge. E.g.,
420 #5 - overlapping following ranges
423 |------------------------|
424 |--| |---| |------| ... |--|
433 |--| |---| |------| ... |--|
440 i = VEC_lower_bound (range_s, value->unavailable, &newr, range_lessthan);
443 struct range *bef = VEC_index (range_s, value->unavailable, i - 1);
445 if (ranges_overlap (bef->offset, bef->length, offset, length))
448 ULONGEST l = min (bef->offset, offset);
449 ULONGEST h = max (bef->offset + bef->length, offset + length);
455 else if (offset == bef->offset + bef->length)
458 bef->length += length;
464 VEC_safe_insert (range_s, value->unavailable, i, &newr);
470 VEC_safe_insert (range_s, value->unavailable, i, &newr);
473 /* Check whether the ranges following the one we've just added or
474 touched can be folded in (#5 above). */
475 if (i + 1 < VEC_length (range_s, value->unavailable))
482 /* Get the range we just touched. */
483 t = VEC_index (range_s, value->unavailable, i);
487 for (; VEC_iterate (range_s, value->unavailable, i, r); i++)
488 if (r->offset <= t->offset + t->length)
492 l = min (t->offset, r->offset);
493 h = max (t->offset + t->length, r->offset + r->length);
502 /* If we couldn't merge this one, we won't be able to
503 merge following ones either, since the ranges are
504 always sorted by OFFSET. */
509 VEC_block_remove (range_s, value->unavailable, next, removed);
513 /* Find the first range in RANGES that overlaps the range defined by
514 OFFSET and LENGTH, starting at element POS in the RANGES vector,
515 Returns the index into RANGES where such overlapping range was
516 found, or -1 if none was found. */
519 find_first_range_overlap (VEC(range_s) *ranges, int pos,
520 int offset, int length)
525 for (i = pos; VEC_iterate (range_s, ranges, i, r); i++)
526 if (ranges_overlap (r->offset, r->length, offset, length))
533 value_available_contents_eq (const struct value *val1, int offset1,
534 const struct value *val2, int offset2,
537 int idx1 = 0, idx2 = 0;
539 /* This routine is used by printing routines, where we should
540 already have read the value. Note that we only know whether a
541 value chunk is available if we've tried to read it. */
542 gdb_assert (!val1->lazy && !val2->lazy);
550 idx1 = find_first_range_overlap (val1->unavailable, idx1,
552 idx2 = find_first_range_overlap (val2->unavailable, idx2,
555 /* The usual case is for both values to be completely available. */
556 if (idx1 == -1 && idx2 == -1)
557 return (memcmp (val1->contents + offset1,
558 val2->contents + offset2,
560 /* The contents only match equal if the available set matches as
562 else if (idx1 == -1 || idx2 == -1)
565 gdb_assert (idx1 != -1 && idx2 != -1);
567 r1 = VEC_index (range_s, val1->unavailable, idx1);
568 r2 = VEC_index (range_s, val2->unavailable, idx2);
570 /* Get the unavailable windows intersected by the incoming
571 ranges. The first and last ranges that overlap the argument
572 range may be wider than said incoming arguments ranges. */
573 l1 = max (offset1, r1->offset);
574 h1 = min (offset1 + length, r1->offset + r1->length);
576 l2 = max (offset2, r2->offset);
577 h2 = min (offset2 + length, r2->offset + r2->length);
579 /* Make them relative to the respective start offsets, so we can
580 compare them for equality. */
587 /* Different availability, no match. */
588 if (l1 != l2 || h1 != h2)
591 /* Compare the _available_ contents. */
592 if (memcmp (val1->contents + offset1,
593 val2->contents + offset2,
605 /* Prototypes for local functions. */
607 static void show_values (char *, int);
609 static void show_convenience (char *, int);
612 /* The value-history records all the values printed
613 by print commands during this session. Each chunk
614 records 60 consecutive values. The first chunk on
615 the chain records the most recent values.
616 The total number of values is in value_history_count. */
618 #define VALUE_HISTORY_CHUNK 60
620 struct value_history_chunk
622 struct value_history_chunk *next;
623 struct value *values[VALUE_HISTORY_CHUNK];
626 /* Chain of chunks now in use. */
628 static struct value_history_chunk *value_history_chain;
630 static int value_history_count; /* Abs number of last entry stored. */
633 /* List of all value objects currently allocated
634 (except for those released by calls to release_value)
635 This is so they can be freed after each command. */
637 static struct value *all_values;
639 /* Allocate a lazy value for type TYPE. Its actual content is
640 "lazily" allocated too: the content field of the return value is
641 NULL; it will be allocated when it is fetched from the target. */
644 allocate_value_lazy (struct type *type)
648 /* Call check_typedef on our type to make sure that, if TYPE
649 is a TYPE_CODE_TYPEDEF, its length is set to the length
650 of the target type instead of zero. However, we do not
651 replace the typedef type by the target type, because we want
652 to keep the typedef in order to be able to set the VAL's type
653 description correctly. */
654 check_typedef (type);
656 val = (struct value *) xzalloc (sizeof (struct value));
657 val->contents = NULL;
658 val->next = all_values;
661 val->enclosing_type = type;
662 VALUE_LVAL (val) = not_lval;
663 val->location.address = 0;
664 VALUE_FRAME_ID (val) = null_frame_id;
668 VALUE_REGNUM (val) = -1;
670 val->optimized_out = 0;
671 val->embedded_offset = 0;
672 val->pointed_to_offset = 0;
674 val->initialized = 1; /* Default to initialized. */
676 /* Values start out on the all_values chain. */
677 val->reference_count = 1;
682 /* Allocate the contents of VAL if it has not been allocated yet. */
685 allocate_value_contents (struct value *val)
688 val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
691 /* Allocate a value and its contents for type TYPE. */
694 allocate_value (struct type *type)
696 struct value *val = allocate_value_lazy (type);
698 allocate_value_contents (val);
703 /* Allocate a value that has the correct length
704 for COUNT repetitions of type TYPE. */
707 allocate_repeat_value (struct type *type, int count)
709 int low_bound = current_language->string_lower_bound; /* ??? */
710 /* FIXME-type-allocation: need a way to free this type when we are
712 struct type *array_type
713 = lookup_array_range_type (type, low_bound, count + low_bound - 1);
715 return allocate_value (array_type);
719 allocate_computed_value (struct type *type,
720 const struct lval_funcs *funcs,
723 struct value *v = allocate_value_lazy (type);
725 VALUE_LVAL (v) = lval_computed;
726 v->location.computed.funcs = funcs;
727 v->location.computed.closure = closure;
732 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
735 allocate_optimized_out_value (struct type *type)
737 struct value *retval = allocate_value_lazy (type);
739 set_value_optimized_out (retval, 1);
744 /* Accessor methods. */
747 value_next (struct value *value)
753 value_type (const struct value *value)
758 deprecated_set_value_type (struct value *value, struct type *type)
764 value_offset (const struct value *value)
766 return value->offset;
769 set_value_offset (struct value *value, int offset)
771 value->offset = offset;
775 value_bitpos (const struct value *value)
777 return value->bitpos;
780 set_value_bitpos (struct value *value, int bit)
786 value_bitsize (const struct value *value)
788 return value->bitsize;
791 set_value_bitsize (struct value *value, int bit)
793 value->bitsize = bit;
797 value_parent (struct value *value)
799 return value->parent;
803 value_contents_raw (struct value *value)
805 allocate_value_contents (value);
806 return value->contents + value->embedded_offset;
810 value_contents_all_raw (struct value *value)
812 allocate_value_contents (value);
813 return value->contents;
817 value_enclosing_type (struct value *value)
819 return value->enclosing_type;
823 require_not_optimized_out (const struct value *value)
825 if (value->optimized_out)
826 error (_("value has been optimized out"));
830 require_available (const struct value *value)
832 if (!VEC_empty (range_s, value->unavailable))
833 throw_error (NOT_AVAILABLE_ERROR, _("value is not available"));
837 value_contents_for_printing (struct value *value)
840 value_fetch_lazy (value);
841 return value->contents;
845 value_contents_for_printing_const (const struct value *value)
847 gdb_assert (!value->lazy);
848 return value->contents;
852 value_contents_all (struct value *value)
854 const gdb_byte *result = value_contents_for_printing (value);
855 require_not_optimized_out (value);
856 require_available (value);
860 /* Copy LENGTH bytes of SRC value's (all) contents
861 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
862 contents, starting at DST_OFFSET. If unavailable contents are
863 being copied from SRC, the corresponding DST contents are marked
864 unavailable accordingly. Neither DST nor SRC may be lazy
867 It is assumed the contents of DST in the [DST_OFFSET,
868 DST_OFFSET+LENGTH) range are wholly available. */
871 value_contents_copy_raw (struct value *dst, int dst_offset,
872 struct value *src, int src_offset, int length)
877 /* A lazy DST would make that this copy operation useless, since as
878 soon as DST's contents were un-lazied (by a later value_contents
879 call, say), the contents would be overwritten. A lazy SRC would
880 mean we'd be copying garbage. */
881 gdb_assert (!dst->lazy && !src->lazy);
883 /* The overwritten DST range gets unavailability ORed in, not
884 replaced. Make sure to remember to implement replacing if it
885 turns out actually necessary. */
886 gdb_assert (value_bytes_available (dst, dst_offset, length));
889 memcpy (value_contents_all_raw (dst) + dst_offset,
890 value_contents_all_raw (src) + src_offset,
893 /* Copy the meta-data, adjusted. */
894 for (i = 0; VEC_iterate (range_s, src->unavailable, i, r); i++)
898 l = max (r->offset, src_offset);
899 h = min (r->offset + r->length, src_offset + length);
902 mark_value_bytes_unavailable (dst,
903 dst_offset + (l - src_offset),
908 /* Copy LENGTH bytes of SRC value's (all) contents
909 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
910 (all) contents, starting at DST_OFFSET. If unavailable contents
911 are being copied from SRC, the corresponding DST contents are
912 marked unavailable accordingly. DST must not be lazy. If SRC is
913 lazy, it will be fetched now. If SRC is not valid (is optimized
914 out), an error is thrown.
916 It is assumed the contents of DST in the [DST_OFFSET,
917 DST_OFFSET+LENGTH) range are wholly available. */
920 value_contents_copy (struct value *dst, int dst_offset,
921 struct value *src, int src_offset, int length)
923 require_not_optimized_out (src);
926 value_fetch_lazy (src);
928 value_contents_copy_raw (dst, dst_offset, src, src_offset, length);
932 value_lazy (struct value *value)
938 set_value_lazy (struct value *value, int val)
944 value_stack (struct value *value)
950 set_value_stack (struct value *value, int val)
956 value_contents (struct value *value)
958 const gdb_byte *result = value_contents_writeable (value);
959 require_not_optimized_out (value);
960 require_available (value);
965 value_contents_writeable (struct value *value)
968 value_fetch_lazy (value);
969 return value_contents_raw (value);
972 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
973 this function is different from value_equal; in C the operator ==
974 can return 0 even if the two values being compared are equal. */
977 value_contents_equal (struct value *val1, struct value *val2)
983 type1 = check_typedef (value_type (val1));
984 type2 = check_typedef (value_type (val2));
985 len = TYPE_LENGTH (type1);
986 if (len != TYPE_LENGTH (type2))
989 return (memcmp (value_contents (val1), value_contents (val2), len) == 0);
993 value_optimized_out (struct value *value)
995 return value->optimized_out;
999 set_value_optimized_out (struct value *value, int val)
1001 value->optimized_out = val;
1005 value_entirely_optimized_out (const struct value *value)
1007 if (!value->optimized_out)
1009 if (value->lval != lval_computed
1010 || !value->location.computed.funcs->check_any_valid)
1012 return !value->location.computed.funcs->check_any_valid (value);
1016 value_bits_valid (const struct value *value, int offset, int length)
1018 if (!value->optimized_out)
1020 if (value->lval != lval_computed
1021 || !value->location.computed.funcs->check_validity)
1023 return value->location.computed.funcs->check_validity (value, offset,
1028 value_bits_synthetic_pointer (const struct value *value,
1029 int offset, int length)
1031 if (value->lval != lval_computed
1032 || !value->location.computed.funcs->check_synthetic_pointer)
1034 return value->location.computed.funcs->check_synthetic_pointer (value,
1040 value_embedded_offset (struct value *value)
1042 return value->embedded_offset;
1046 set_value_embedded_offset (struct value *value, int val)
1048 value->embedded_offset = val;
1052 value_pointed_to_offset (struct value *value)
1054 return value->pointed_to_offset;
1058 set_value_pointed_to_offset (struct value *value, int val)
1060 value->pointed_to_offset = val;
1063 const struct lval_funcs *
1064 value_computed_funcs (const struct value *v)
1066 gdb_assert (value_lval_const (v) == lval_computed);
1068 return v->location.computed.funcs;
1072 value_computed_closure (const struct value *v)
1074 gdb_assert (v->lval == lval_computed);
1076 return v->location.computed.closure;
1080 deprecated_value_lval_hack (struct value *value)
1082 return &value->lval;
1086 value_lval_const (const struct value *value)
1092 value_address (const struct value *value)
1094 if (value->lval == lval_internalvar
1095 || value->lval == lval_internalvar_component)
1097 return value->location.address + value->offset;
1101 value_raw_address (struct value *value)
1103 if (value->lval == lval_internalvar
1104 || value->lval == lval_internalvar_component)
1106 return value->location.address;
1110 set_value_address (struct value *value, CORE_ADDR addr)
1112 gdb_assert (value->lval != lval_internalvar
1113 && value->lval != lval_internalvar_component);
1114 value->location.address = addr;
1117 struct internalvar **
1118 deprecated_value_internalvar_hack (struct value *value)
1120 return &value->location.internalvar;
1124 deprecated_value_frame_id_hack (struct value *value)
1126 return &value->frame_id;
1130 deprecated_value_regnum_hack (struct value *value)
1132 return &value->regnum;
1136 deprecated_value_modifiable (struct value *value)
1138 return value->modifiable;
1141 deprecated_set_value_modifiable (struct value *value, int modifiable)
1143 value->modifiable = modifiable;
1146 /* Return a mark in the value chain. All values allocated after the
1147 mark is obtained (except for those released) are subject to being freed
1148 if a subsequent value_free_to_mark is passed the mark. */
1155 /* Take a reference to VAL. VAL will not be deallocated until all
1156 references are released. */
1159 value_incref (struct value *val)
1161 val->reference_count++;
1164 /* Release a reference to VAL, which was acquired with value_incref.
1165 This function is also called to deallocate values from the value
1169 value_free (struct value *val)
1173 gdb_assert (val->reference_count > 0);
1174 val->reference_count--;
1175 if (val->reference_count > 0)
1178 /* If there's an associated parent value, drop our reference to
1180 if (val->parent != NULL)
1181 value_free (val->parent);
1183 if (VALUE_LVAL (val) == lval_computed)
1185 const struct lval_funcs *funcs = val->location.computed.funcs;
1187 if (funcs->free_closure)
1188 funcs->free_closure (val);
1191 xfree (val->contents);
1192 VEC_free (range_s, val->unavailable);
1197 /* Free all values allocated since MARK was obtained by value_mark
1198 (except for those released). */
1200 value_free_to_mark (struct value *mark)
1205 for (val = all_values; val && val != mark; val = next)
1213 /* Free all the values that have been allocated (except for those released).
1214 Call after each command, successful or not.
1215 In practice this is called before each command, which is sufficient. */
1218 free_all_values (void)
1223 for (val = all_values; val; val = next)
1232 /* Frees all the elements in a chain of values. */
1235 free_value_chain (struct value *v)
1241 next = value_next (v);
1246 /* Remove VAL from the chain all_values
1247 so it will not be freed automatically. */
1250 release_value (struct value *val)
1254 if (all_values == val)
1256 all_values = val->next;
1261 for (v = all_values; v; v = v->next)
1265 v->next = val->next;
1272 /* Release all values up to mark */
1274 value_release_to_mark (struct value *mark)
1279 for (val = next = all_values; next; next = next->next)
1280 if (next->next == mark)
1282 all_values = next->next;
1290 /* Return a copy of the value ARG.
1291 It contains the same contents, for same memory address,
1292 but it's a different block of storage. */
1295 value_copy (struct value *arg)
1297 struct type *encl_type = value_enclosing_type (arg);
1300 if (value_lazy (arg))
1301 val = allocate_value_lazy (encl_type);
1303 val = allocate_value (encl_type);
1304 val->type = arg->type;
1305 VALUE_LVAL (val) = VALUE_LVAL (arg);
1306 val->location = arg->location;
1307 val->offset = arg->offset;
1308 val->bitpos = arg->bitpos;
1309 val->bitsize = arg->bitsize;
1310 VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
1311 VALUE_REGNUM (val) = VALUE_REGNUM (arg);
1312 val->lazy = arg->lazy;
1313 val->optimized_out = arg->optimized_out;
1314 val->embedded_offset = value_embedded_offset (arg);
1315 val->pointed_to_offset = arg->pointed_to_offset;
1316 val->modifiable = arg->modifiable;
1317 if (!value_lazy (val))
1319 memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
1320 TYPE_LENGTH (value_enclosing_type (arg)));
1323 val->unavailable = VEC_copy (range_s, arg->unavailable);
1324 val->parent = arg->parent;
1326 value_incref (val->parent);
1327 if (VALUE_LVAL (val) == lval_computed)
1329 const struct lval_funcs *funcs = val->location.computed.funcs;
1331 if (funcs->copy_closure)
1332 val->location.computed.closure = funcs->copy_closure (val);
1337 /* Return a version of ARG that is non-lvalue. */
1340 value_non_lval (struct value *arg)
1342 if (VALUE_LVAL (arg) != not_lval)
1344 struct type *enc_type = value_enclosing_type (arg);
1345 struct value *val = allocate_value (enc_type);
1347 memcpy (value_contents_all_raw (val), value_contents_all (arg),
1348 TYPE_LENGTH (enc_type));
1349 val->type = arg->type;
1350 set_value_embedded_offset (val, value_embedded_offset (arg));
1351 set_value_pointed_to_offset (val, value_pointed_to_offset (arg));
1358 set_value_component_location (struct value *component,
1359 const struct value *whole)
1361 if (whole->lval == lval_internalvar)
1362 VALUE_LVAL (component) = lval_internalvar_component;
1364 VALUE_LVAL (component) = whole->lval;
1366 component->location = whole->location;
1367 if (whole->lval == lval_computed)
1369 const struct lval_funcs *funcs = whole->location.computed.funcs;
1371 if (funcs->copy_closure)
1372 component->location.computed.closure = funcs->copy_closure (whole);
1377 /* Access to the value history. */
1379 /* Record a new value in the value history.
1380 Returns the absolute history index of the entry.
1381 Result of -1 indicates the value was not saved; otherwise it is the
1382 value history index of this new item. */
1385 record_latest_value (struct value *val)
1389 /* We don't want this value to have anything to do with the inferior anymore.
1390 In particular, "set $1 = 50" should not affect the variable from which
1391 the value was taken, and fast watchpoints should be able to assume that
1392 a value on the value history never changes. */
1393 if (value_lazy (val))
1394 value_fetch_lazy (val);
1395 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1396 from. This is a bit dubious, because then *&$1 does not just return $1
1397 but the current contents of that location. c'est la vie... */
1398 val->modifiable = 0;
1399 release_value (val);
1401 /* Here we treat value_history_count as origin-zero
1402 and applying to the value being stored now. */
1404 i = value_history_count % VALUE_HISTORY_CHUNK;
1407 struct value_history_chunk *new
1408 = (struct value_history_chunk *)
1410 xmalloc (sizeof (struct value_history_chunk));
1411 memset (new->values, 0, sizeof new->values);
1412 new->next = value_history_chain;
1413 value_history_chain = new;
1416 value_history_chain->values[i] = val;
1418 /* Now we regard value_history_count as origin-one
1419 and applying to the value just stored. */
1421 return ++value_history_count;
1424 /* Return a copy of the value in the history with sequence number NUM. */
1427 access_value_history (int num)
1429 struct value_history_chunk *chunk;
1434 absnum += value_history_count;
1439 error (_("The history is empty."));
1441 error (_("There is only one value in the history."));
1443 error (_("History does not go back to $$%d."), -num);
1445 if (absnum > value_history_count)
1446 error (_("History has not yet reached $%d."), absnum);
1450 /* Now absnum is always absolute and origin zero. */
1452 chunk = value_history_chain;
1453 for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK
1454 - absnum / VALUE_HISTORY_CHUNK;
1456 chunk = chunk->next;
1458 return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
1462 show_values (char *num_exp, int from_tty)
1470 /* "show values +" should print from the stored position.
1471 "show values <exp>" should print around value number <exp>. */
1472 if (num_exp[0] != '+' || num_exp[1] != '\0')
1473 num = parse_and_eval_long (num_exp) - 5;
1477 /* "show values" means print the last 10 values. */
1478 num = value_history_count - 9;
1484 for (i = num; i < num + 10 && i <= value_history_count; i++)
1486 struct value_print_options opts;
1488 val = access_value_history (i);
1489 printf_filtered (("$%d = "), i);
1490 get_user_print_options (&opts);
1491 value_print (val, gdb_stdout, &opts);
1492 printf_filtered (("\n"));
1495 /* The next "show values +" should start after what we just printed. */
1498 /* Hitting just return after this command should do the same thing as
1499 "show values +". If num_exp is null, this is unnecessary, since
1500 "show values +" is not useful after "show values". */
1501 if (from_tty && num_exp)
1508 /* Internal variables. These are variables within the debugger
1509 that hold values assigned by debugger commands.
1510 The user refers to them with a '$' prefix
1511 that does not appear in the variable names stored internally. */
1515 struct internalvar *next;
1518 /* We support various different kinds of content of an internal variable.
1519 enum internalvar_kind specifies the kind, and union internalvar_data
1520 provides the data associated with this particular kind. */
1522 enum internalvar_kind
1524 /* The internal variable is empty. */
1527 /* The value of the internal variable is provided directly as
1528 a GDB value object. */
1531 /* A fresh value is computed via a call-back routine on every
1532 access to the internal variable. */
1533 INTERNALVAR_MAKE_VALUE,
1535 /* The internal variable holds a GDB internal convenience function. */
1536 INTERNALVAR_FUNCTION,
1538 /* The variable holds an integer value. */
1539 INTERNALVAR_INTEGER,
1541 /* The variable holds a GDB-provided string. */
1546 union internalvar_data
1548 /* A value object used with INTERNALVAR_VALUE. */
1549 struct value *value;
1551 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1552 internalvar_make_value make_value;
1554 /* The internal function used with INTERNALVAR_FUNCTION. */
1557 struct internal_function *function;
1558 /* True if this is the canonical name for the function. */
1562 /* An integer value used with INTERNALVAR_INTEGER. */
1565 /* If type is non-NULL, it will be used as the type to generate
1566 a value for this internal variable. If type is NULL, a default
1567 integer type for the architecture is used. */
1572 /* A string value used with INTERNALVAR_STRING. */
1577 static struct internalvar *internalvars;
1579 /* If the variable does not already exist create it and give it the
1580 value given. If no value is given then the default is zero. */
1582 init_if_undefined_command (char* args, int from_tty)
1584 struct internalvar* intvar;
1586 /* Parse the expression - this is taken from set_command(). */
1587 struct expression *expr = parse_expression (args);
1588 register struct cleanup *old_chain =
1589 make_cleanup (free_current_contents, &expr);
1591 /* Validate the expression.
1592 Was the expression an assignment?
1593 Or even an expression at all? */
1594 if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
1595 error (_("Init-if-undefined requires an assignment expression."));
1597 /* Extract the variable from the parsed expression.
1598 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1599 if (expr->elts[1].opcode != OP_INTERNALVAR)
1600 error (_("The first parameter to init-if-undefined "
1601 "should be a GDB variable."));
1602 intvar = expr->elts[2].internalvar;
1604 /* Only evaluate the expression if the lvalue is void.
1605 This may still fail if the expresssion is invalid. */
1606 if (intvar->kind == INTERNALVAR_VOID)
1607 evaluate_expression (expr);
1609 do_cleanups (old_chain);
1613 /* Look up an internal variable with name NAME. NAME should not
1614 normally include a dollar sign.
1616 If the specified internal variable does not exist,
1617 the return value is NULL. */
1619 struct internalvar *
1620 lookup_only_internalvar (const char *name)
1622 struct internalvar *var;
1624 for (var = internalvars; var; var = var->next)
1625 if (strcmp (var->name, name) == 0)
1632 /* Create an internal variable with name NAME and with a void value.
1633 NAME should not normally include a dollar sign. */
1635 struct internalvar *
1636 create_internalvar (const char *name)
1638 struct internalvar *var;
1640 var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
1641 var->name = concat (name, (char *)NULL);
1642 var->kind = INTERNALVAR_VOID;
1643 var->next = internalvars;
1648 /* Create an internal variable with name NAME and register FUN as the
1649 function that value_of_internalvar uses to create a value whenever
1650 this variable is referenced. NAME should not normally include a
1653 struct internalvar *
1654 create_internalvar_type_lazy (char *name, internalvar_make_value fun)
1656 struct internalvar *var = create_internalvar (name);
1658 var->kind = INTERNALVAR_MAKE_VALUE;
1659 var->u.make_value = fun;
1663 /* Look up an internal variable with name NAME. NAME should not
1664 normally include a dollar sign.
1666 If the specified internal variable does not exist,
1667 one is created, with a void value. */
1669 struct internalvar *
1670 lookup_internalvar (const char *name)
1672 struct internalvar *var;
1674 var = lookup_only_internalvar (name);
1678 return create_internalvar (name);
1681 /* Return current value of internal variable VAR. For variables that
1682 are not inherently typed, use a value type appropriate for GDBARCH. */
1685 value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
1688 struct trace_state_variable *tsv;
1690 /* If there is a trace state variable of the same name, assume that
1691 is what we really want to see. */
1692 tsv = find_trace_state_variable (var->name);
1695 tsv->value_known = target_get_trace_state_variable_value (tsv->number,
1697 if (tsv->value_known)
1698 val = value_from_longest (builtin_type (gdbarch)->builtin_int64,
1701 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1707 case INTERNALVAR_VOID:
1708 val = allocate_value (builtin_type (gdbarch)->builtin_void);
1711 case INTERNALVAR_FUNCTION:
1712 val = allocate_value (builtin_type (gdbarch)->internal_fn);
1715 case INTERNALVAR_INTEGER:
1716 if (!var->u.integer.type)
1717 val = value_from_longest (builtin_type (gdbarch)->builtin_int,
1718 var->u.integer.val);
1720 val = value_from_longest (var->u.integer.type, var->u.integer.val);
1723 case INTERNALVAR_STRING:
1724 val = value_cstring (var->u.string, strlen (var->u.string),
1725 builtin_type (gdbarch)->builtin_char);
1728 case INTERNALVAR_VALUE:
1729 val = value_copy (var->u.value);
1730 if (value_lazy (val))
1731 value_fetch_lazy (val);
1734 case INTERNALVAR_MAKE_VALUE:
1735 val = (*var->u.make_value) (gdbarch, var);
1739 internal_error (__FILE__, __LINE__, _("bad kind"));
1742 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1743 on this value go back to affect the original internal variable.
1745 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1746 no underlying modifyable state in the internal variable.
1748 Likewise, if the variable's value is a computed lvalue, we want
1749 references to it to produce another computed lvalue, where
1750 references and assignments actually operate through the
1751 computed value's functions.
1753 This means that internal variables with computed values
1754 behave a little differently from other internal variables:
1755 assignments to them don't just replace the previous value
1756 altogether. At the moment, this seems like the behavior we
1759 if (var->kind != INTERNALVAR_MAKE_VALUE
1760 && val->lval != lval_computed)
1762 VALUE_LVAL (val) = lval_internalvar;
1763 VALUE_INTERNALVAR (val) = var;
1770 get_internalvar_integer (struct internalvar *var, LONGEST *result)
1772 if (var->kind == INTERNALVAR_INTEGER)
1774 *result = var->u.integer.val;
1778 if (var->kind == INTERNALVAR_VALUE)
1780 struct type *type = check_typedef (value_type (var->u.value));
1782 if (TYPE_CODE (type) == TYPE_CODE_INT)
1784 *result = value_as_long (var->u.value);
1793 get_internalvar_function (struct internalvar *var,
1794 struct internal_function **result)
1798 case INTERNALVAR_FUNCTION:
1799 *result = var->u.fn.function;
1808 set_internalvar_component (struct internalvar *var, int offset, int bitpos,
1809 int bitsize, struct value *newval)
1815 case INTERNALVAR_VALUE:
1816 addr = value_contents_writeable (var->u.value);
1819 modify_field (value_type (var->u.value), addr + offset,
1820 value_as_long (newval), bitpos, bitsize);
1822 memcpy (addr + offset, value_contents (newval),
1823 TYPE_LENGTH (value_type (newval)));
1827 /* We can never get a component of any other kind. */
1828 internal_error (__FILE__, __LINE__, _("set_internalvar_component"));
1833 set_internalvar (struct internalvar *var, struct value *val)
1835 enum internalvar_kind new_kind;
1836 union internalvar_data new_data = { 0 };
1838 if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
1839 error (_("Cannot overwrite convenience function %s"), var->name);
1841 /* Prepare new contents. */
1842 switch (TYPE_CODE (check_typedef (value_type (val))))
1844 case TYPE_CODE_VOID:
1845 new_kind = INTERNALVAR_VOID;
1848 case TYPE_CODE_INTERNAL_FUNCTION:
1849 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1850 new_kind = INTERNALVAR_FUNCTION;
1851 get_internalvar_function (VALUE_INTERNALVAR (val),
1852 &new_data.fn.function);
1853 /* Copies created here are never canonical. */
1857 new_kind = INTERNALVAR_VALUE;
1858 new_data.value = value_copy (val);
1859 new_data.value->modifiable = 1;
1861 /* Force the value to be fetched from the target now, to avoid problems
1862 later when this internalvar is referenced and the target is gone or
1864 if (value_lazy (new_data.value))
1865 value_fetch_lazy (new_data.value);
1867 /* Release the value from the value chain to prevent it from being
1868 deleted by free_all_values. From here on this function should not
1869 call error () until new_data is installed into the var->u to avoid
1871 release_value (new_data.value);
1875 /* Clean up old contents. */
1876 clear_internalvar (var);
1879 var->kind = new_kind;
1881 /* End code which must not call error(). */
1885 set_internalvar_integer (struct internalvar *var, LONGEST l)
1887 /* Clean up old contents. */
1888 clear_internalvar (var);
1890 var->kind = INTERNALVAR_INTEGER;
1891 var->u.integer.type = NULL;
1892 var->u.integer.val = l;
1896 set_internalvar_string (struct internalvar *var, const char *string)
1898 /* Clean up old contents. */
1899 clear_internalvar (var);
1901 var->kind = INTERNALVAR_STRING;
1902 var->u.string = xstrdup (string);
1906 set_internalvar_function (struct internalvar *var, struct internal_function *f)
1908 /* Clean up old contents. */
1909 clear_internalvar (var);
1911 var->kind = INTERNALVAR_FUNCTION;
1912 var->u.fn.function = f;
1913 var->u.fn.canonical = 1;
1914 /* Variables installed here are always the canonical version. */
1918 clear_internalvar (struct internalvar *var)
1920 /* Clean up old contents. */
1923 case INTERNALVAR_VALUE:
1924 value_free (var->u.value);
1927 case INTERNALVAR_STRING:
1928 xfree (var->u.string);
1935 /* Reset to void kind. */
1936 var->kind = INTERNALVAR_VOID;
1940 internalvar_name (struct internalvar *var)
1945 static struct internal_function *
1946 create_internal_function (const char *name,
1947 internal_function_fn handler, void *cookie)
1949 struct internal_function *ifn = XNEW (struct internal_function);
1951 ifn->name = xstrdup (name);
1952 ifn->handler = handler;
1953 ifn->cookie = cookie;
1958 value_internal_function_name (struct value *val)
1960 struct internal_function *ifn;
1963 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
1964 result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
1965 gdb_assert (result);
1971 call_internal_function (struct gdbarch *gdbarch,
1972 const struct language_defn *language,
1973 struct value *func, int argc, struct value **argv)
1975 struct internal_function *ifn;
1978 gdb_assert (VALUE_LVAL (func) == lval_internalvar);
1979 result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
1980 gdb_assert (result);
1982 return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
1985 /* The 'function' command. This does nothing -- it is just a
1986 placeholder to let "help function NAME" work. This is also used as
1987 the implementation of the sub-command that is created when
1988 registering an internal function. */
1990 function_command (char *command, int from_tty)
1995 /* Clean up if an internal function's command is destroyed. */
1997 function_destroyer (struct cmd_list_element *self, void *ignore)
2003 /* Add a new internal function. NAME is the name of the function; DOC
2004 is a documentation string describing the function. HANDLER is
2005 called when the function is invoked. COOKIE is an arbitrary
2006 pointer which is passed to HANDLER and is intended for "user
2009 add_internal_function (const char *name, const char *doc,
2010 internal_function_fn handler, void *cookie)
2012 struct cmd_list_element *cmd;
2013 struct internal_function *ifn;
2014 struct internalvar *var = lookup_internalvar (name);
2016 ifn = create_internal_function (name, handler, cookie);
2017 set_internalvar_function (var, ifn);
2019 cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
2021 cmd->destroyer = function_destroyer;
2024 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2025 prevent cycles / duplicates. */
2028 preserve_one_value (struct value *value, struct objfile *objfile,
2029 htab_t copied_types)
2031 if (TYPE_OBJFILE (value->type) == objfile)
2032 value->type = copy_type_recursive (objfile, value->type, copied_types);
2034 if (TYPE_OBJFILE (value->enclosing_type) == objfile)
2035 value->enclosing_type = copy_type_recursive (objfile,
2036 value->enclosing_type,
2040 /* Likewise for internal variable VAR. */
2043 preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
2044 htab_t copied_types)
2048 case INTERNALVAR_INTEGER:
2049 if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
2051 = copy_type_recursive (objfile, var->u.integer.type, copied_types);
2054 case INTERNALVAR_VALUE:
2055 preserve_one_value (var->u.value, objfile, copied_types);
2060 /* Update the internal variables and value history when OBJFILE is
2061 discarded; we must copy the types out of the objfile. New global types
2062 will be created for every convenience variable which currently points to
2063 this objfile's types, and the convenience variables will be adjusted to
2064 use the new global types. */
2067 preserve_values (struct objfile *objfile)
2069 htab_t copied_types;
2070 struct value_history_chunk *cur;
2071 struct internalvar *var;
2074 /* Create the hash table. We allocate on the objfile's obstack, since
2075 it is soon to be deleted. */
2076 copied_types = create_copied_types_hash (objfile);
2078 for (cur = value_history_chain; cur; cur = cur->next)
2079 for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
2081 preserve_one_value (cur->values[i], objfile, copied_types);
2083 for (var = internalvars; var; var = var->next)
2084 preserve_one_internalvar (var, objfile, copied_types);
2086 preserve_python_values (objfile, copied_types);
2088 htab_delete (copied_types);
2092 show_convenience (char *ignore, int from_tty)
2094 struct gdbarch *gdbarch = get_current_arch ();
2095 struct internalvar *var;
2097 struct value_print_options opts;
2099 get_user_print_options (&opts);
2100 for (var = internalvars; var; var = var->next)
2102 volatile struct gdb_exception ex;
2108 printf_filtered (("$%s = "), var->name);
2110 TRY_CATCH (ex, RETURN_MASK_ERROR)
2114 val = value_of_internalvar (gdbarch, var);
2115 value_print (val, gdb_stdout, &opts);
2118 fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
2119 printf_filtered (("\n"));
2122 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2123 "Convenience variables have "
2124 "names starting with \"$\";\n"
2125 "use \"set\" as in \"set "
2126 "$foo = 5\" to define them.\n"));
2129 /* Extract a value as a C number (either long or double).
2130 Knows how to convert fixed values to double, or
2131 floating values to long.
2132 Does not deallocate the value. */
2135 value_as_long (struct value *val)
2137 /* This coerces arrays and functions, which is necessary (e.g.
2138 in disassemble_command). It also dereferences references, which
2139 I suspect is the most logical thing to do. */
2140 val = coerce_array (val);
2141 return unpack_long (value_type (val), value_contents (val));
2145 value_as_double (struct value *val)
2150 foo = unpack_double (value_type (val), value_contents (val), &inv);
2152 error (_("Invalid floating value found in program."));
2156 /* Extract a value as a C pointer. Does not deallocate the value.
2157 Note that val's type may not actually be a pointer; value_as_long
2158 handles all the cases. */
2160 value_as_address (struct value *val)
2162 struct gdbarch *gdbarch = get_type_arch (value_type (val));
2164 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2165 whether we want this to be true eventually. */
2167 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2168 non-address (e.g. argument to "signal", "info break", etc.), or
2169 for pointers to char, in which the low bits *are* significant. */
2170 return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
2173 /* There are several targets (IA-64, PowerPC, and others) which
2174 don't represent pointers to functions as simply the address of
2175 the function's entry point. For example, on the IA-64, a
2176 function pointer points to a two-word descriptor, generated by
2177 the linker, which contains the function's entry point, and the
2178 value the IA-64 "global pointer" register should have --- to
2179 support position-independent code. The linker generates
2180 descriptors only for those functions whose addresses are taken.
2182 On such targets, it's difficult for GDB to convert an arbitrary
2183 function address into a function pointer; it has to either find
2184 an existing descriptor for that function, or call malloc and
2185 build its own. On some targets, it is impossible for GDB to
2186 build a descriptor at all: the descriptor must contain a jump
2187 instruction; data memory cannot be executed; and code memory
2190 Upon entry to this function, if VAL is a value of type `function'
2191 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2192 value_address (val) is the address of the function. This is what
2193 you'll get if you evaluate an expression like `main'. The call
2194 to COERCE_ARRAY below actually does all the usual unary
2195 conversions, which includes converting values of type `function'
2196 to `pointer to function'. This is the challenging conversion
2197 discussed above. Then, `unpack_long' will convert that pointer
2198 back into an address.
2200 So, suppose the user types `disassemble foo' on an architecture
2201 with a strange function pointer representation, on which GDB
2202 cannot build its own descriptors, and suppose further that `foo'
2203 has no linker-built descriptor. The address->pointer conversion
2204 will signal an error and prevent the command from running, even
2205 though the next step would have been to convert the pointer
2206 directly back into the same address.
2208 The following shortcut avoids this whole mess. If VAL is a
2209 function, just return its address directly. */
2210 if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
2211 || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
2212 return value_address (val);
2214 val = coerce_array (val);
2216 /* Some architectures (e.g. Harvard), map instruction and data
2217 addresses onto a single large unified address space. For
2218 instance: An architecture may consider a large integer in the
2219 range 0x10000000 .. 0x1000ffff to already represent a data
2220 addresses (hence not need a pointer to address conversion) while
2221 a small integer would still need to be converted integer to
2222 pointer to address. Just assume such architectures handle all
2223 integer conversions in a single function. */
2227 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2228 must admonish GDB hackers to make sure its behavior matches the
2229 compiler's, whenever possible.
2231 In general, I think GDB should evaluate expressions the same way
2232 the compiler does. When the user copies an expression out of
2233 their source code and hands it to a `print' command, they should
2234 get the same value the compiler would have computed. Any
2235 deviation from this rule can cause major confusion and annoyance,
2236 and needs to be justified carefully. In other words, GDB doesn't
2237 really have the freedom to do these conversions in clever and
2240 AndrewC pointed out that users aren't complaining about how GDB
2241 casts integers to pointers; they are complaining that they can't
2242 take an address from a disassembly listing and give it to `x/i'.
2243 This is certainly important.
2245 Adding an architecture method like integer_to_address() certainly
2246 makes it possible for GDB to "get it right" in all circumstances
2247 --- the target has complete control over how things get done, so
2248 people can Do The Right Thing for their target without breaking
2249 anyone else. The standard doesn't specify how integers get
2250 converted to pointers; usually, the ABI doesn't either, but
2251 ABI-specific code is a more reasonable place to handle it. */
2253 if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
2254 && TYPE_CODE (value_type (val)) != TYPE_CODE_REF
2255 && gdbarch_integer_to_address_p (gdbarch))
2256 return gdbarch_integer_to_address (gdbarch, value_type (val),
2257 value_contents (val));
2259 return unpack_long (value_type (val), value_contents (val));
2263 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2264 as a long, or as a double, assuming the raw data is described
2265 by type TYPE. Knows how to convert different sizes of values
2266 and can convert between fixed and floating point. We don't assume
2267 any alignment for the raw data. Return value is in host byte order.
2269 If you want functions and arrays to be coerced to pointers, and
2270 references to be dereferenced, call value_as_long() instead.
2272 C++: It is assumed that the front-end has taken care of
2273 all matters concerning pointers to members. A pointer
2274 to member which reaches here is considered to be equivalent
2275 to an INT (or some size). After all, it is only an offset. */
2278 unpack_long (struct type *type, const gdb_byte *valaddr)
2280 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2281 enum type_code code = TYPE_CODE (type);
2282 int len = TYPE_LENGTH (type);
2283 int nosign = TYPE_UNSIGNED (type);
2287 case TYPE_CODE_TYPEDEF:
2288 return unpack_long (check_typedef (type), valaddr);
2289 case TYPE_CODE_ENUM:
2290 case TYPE_CODE_FLAGS:
2291 case TYPE_CODE_BOOL:
2293 case TYPE_CODE_CHAR:
2294 case TYPE_CODE_RANGE:
2295 case TYPE_CODE_MEMBERPTR:
2297 return extract_unsigned_integer (valaddr, len, byte_order);
2299 return extract_signed_integer (valaddr, len, byte_order);
2302 return extract_typed_floating (valaddr, type);
2304 case TYPE_CODE_DECFLOAT:
2305 /* libdecnumber has a function to convert from decimal to integer, but
2306 it doesn't work when the decimal number has a fractional part. */
2307 return decimal_to_doublest (valaddr, len, byte_order);
2311 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2312 whether we want this to be true eventually. */
2313 return extract_typed_address (valaddr, type);
2316 error (_("Value can't be converted to integer."));
2318 return 0; /* Placate lint. */
2321 /* Return a double value from the specified type and address.
2322 INVP points to an int which is set to 0 for valid value,
2323 1 for invalid value (bad float format). In either case,
2324 the returned double is OK to use. Argument is in target
2325 format, result is in host format. */
2328 unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
2330 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2331 enum type_code code;
2335 *invp = 0; /* Assume valid. */
2336 CHECK_TYPEDEF (type);
2337 code = TYPE_CODE (type);
2338 len = TYPE_LENGTH (type);
2339 nosign = TYPE_UNSIGNED (type);
2340 if (code == TYPE_CODE_FLT)
2342 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2343 floating-point value was valid (using the macro
2344 INVALID_FLOAT). That test/macro have been removed.
2346 It turns out that only the VAX defined this macro and then
2347 only in a non-portable way. Fixing the portability problem
2348 wouldn't help since the VAX floating-point code is also badly
2349 bit-rotten. The target needs to add definitions for the
2350 methods gdbarch_float_format and gdbarch_double_format - these
2351 exactly describe the target floating-point format. The
2352 problem here is that the corresponding floatformat_vax_f and
2353 floatformat_vax_d values these methods should be set to are
2354 also not defined either. Oops!
2356 Hopefully someone will add both the missing floatformat
2357 definitions and the new cases for floatformat_is_valid (). */
2359 if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
2365 return extract_typed_floating (valaddr, type);
2367 else if (code == TYPE_CODE_DECFLOAT)
2368 return decimal_to_doublest (valaddr, len, byte_order);
2371 /* Unsigned -- be sure we compensate for signed LONGEST. */
2372 return (ULONGEST) unpack_long (type, valaddr);
2376 /* Signed -- we are OK with unpack_long. */
2377 return unpack_long (type, valaddr);
2381 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2382 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2383 We don't assume any alignment for the raw data. Return value is in
2386 If you want functions and arrays to be coerced to pointers, and
2387 references to be dereferenced, call value_as_address() instead.
2389 C++: It is assumed that the front-end has taken care of
2390 all matters concerning pointers to members. A pointer
2391 to member which reaches here is considered to be equivalent
2392 to an INT (or some size). After all, it is only an offset. */
2395 unpack_pointer (struct type *type, const gdb_byte *valaddr)
2397 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2398 whether we want this to be true eventually. */
2399 return unpack_long (type, valaddr);
2403 /* Get the value of the FIELDNO'th field (which must be static) of
2404 TYPE. Return NULL if the field doesn't exist or has been
2408 value_static_field (struct type *type, int fieldno)
2410 struct value *retval;
2412 switch (TYPE_FIELD_LOC_KIND (type, fieldno))
2414 case FIELD_LOC_KIND_PHYSADDR:
2415 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2416 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
2418 case FIELD_LOC_KIND_PHYSNAME:
2420 const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
2421 /* TYPE_FIELD_NAME (type, fieldno); */
2422 struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
2426 /* With some compilers, e.g. HP aCC, static data members are
2427 reported as non-debuggable symbols. */
2428 struct minimal_symbol *msym = lookup_minimal_symbol (phys_name,
2435 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2436 SYMBOL_VALUE_ADDRESS (msym));
2440 retval = value_of_variable (sym, NULL);
2444 gdb_assert_not_reached ("unexpected field location kind");
2450 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2451 You have to be careful here, since the size of the data area for the value
2452 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2453 than the old enclosing type, you have to allocate more space for the
2457 set_value_enclosing_type (struct value *val, struct type *new_encl_type)
2459 if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
2461 (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
2463 val->enclosing_type = new_encl_type;
2466 /* Given a value ARG1 (offset by OFFSET bytes)
2467 of a struct or union type ARG_TYPE,
2468 extract and return the value of one of its (non-static) fields.
2469 FIELDNO says which field. */
2472 value_primitive_field (struct value *arg1, int offset,
2473 int fieldno, struct type *arg_type)
2478 CHECK_TYPEDEF (arg_type);
2479 type = TYPE_FIELD_TYPE (arg_type, fieldno);
2481 /* Call check_typedef on our type to make sure that, if TYPE
2482 is a TYPE_CODE_TYPEDEF, its length is set to the length
2483 of the target type instead of zero. However, we do not
2484 replace the typedef type by the target type, because we want
2485 to keep the typedef in order to be able to print the type
2486 description correctly. */
2487 check_typedef (type);
2489 if (value_optimized_out (arg1))
2490 v = allocate_optimized_out_value (type);
2491 else if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
2493 /* Handle packed fields.
2495 Create a new value for the bitfield, with bitpos and bitsize
2496 set. If possible, arrange offset and bitpos so that we can
2497 do a single aligned read of the size of the containing type.
2498 Otherwise, adjust offset to the byte containing the first
2499 bit. Assume that the address, offset, and embedded offset
2500 are sufficiently aligned. */
2502 int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
2503 int container_bitsize = TYPE_LENGTH (type) * 8;
2505 v = allocate_value_lazy (type);
2506 v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
2507 if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
2508 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
2509 v->bitpos = bitpos % container_bitsize;
2511 v->bitpos = bitpos % 8;
2512 v->offset = (value_embedded_offset (arg1)
2514 + (bitpos - v->bitpos) / 8);
2516 value_incref (v->parent);
2517 if (!value_lazy (arg1))
2518 value_fetch_lazy (v);
2520 else if (fieldno < TYPE_N_BASECLASSES (arg_type))
2522 /* This field is actually a base subobject, so preserve the
2523 entire object's contents for later references to virtual
2526 /* Lazy register values with offsets are not supported. */
2527 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2528 value_fetch_lazy (arg1);
2530 if (value_lazy (arg1))
2531 v = allocate_value_lazy (value_enclosing_type (arg1));
2534 v = allocate_value (value_enclosing_type (arg1));
2535 value_contents_copy_raw (v, 0, arg1, 0,
2536 TYPE_LENGTH (value_enclosing_type (arg1)));
2539 v->offset = value_offset (arg1);
2540 v->embedded_offset = (offset + value_embedded_offset (arg1)
2541 + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8);
2545 /* Plain old data member */
2546 offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
2548 /* Lazy register values with offsets are not supported. */
2549 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
2550 value_fetch_lazy (arg1);
2552 if (value_lazy (arg1))
2553 v = allocate_value_lazy (type);
2556 v = allocate_value (type);
2557 value_contents_copy_raw (v, value_embedded_offset (v),
2558 arg1, value_embedded_offset (arg1) + offset,
2559 TYPE_LENGTH (type));
2561 v->offset = (value_offset (arg1) + offset
2562 + value_embedded_offset (arg1));
2564 set_value_component_location (v, arg1);
2565 VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
2566 VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
2570 /* Given a value ARG1 of a struct or union type,
2571 extract and return the value of one of its (non-static) fields.
2572 FIELDNO says which field. */
2575 value_field (struct value *arg1, int fieldno)
2577 return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
2580 /* Return a non-virtual function as a value.
2581 F is the list of member functions which contains the desired method.
2582 J is an index into F which provides the desired method.
2584 We only use the symbol for its address, so be happy with either a
2585 full symbol or a minimal symbol. */
2588 value_fn_field (struct value **arg1p, struct fn_field *f,
2589 int j, struct type *type,
2593 struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
2594 const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
2596 struct minimal_symbol *msym;
2598 sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
2605 gdb_assert (sym == NULL);
2606 msym = lookup_minimal_symbol (physname, NULL, NULL);
2611 v = allocate_value (ftype);
2614 set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
2618 /* The minimal symbol might point to a function descriptor;
2619 resolve it to the actual code address instead. */
2620 struct objfile *objfile = msymbol_objfile (msym);
2621 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2623 set_value_address (v,
2624 gdbarch_convert_from_func_ptr_addr
2625 (gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target));
2630 if (type != value_type (*arg1p))
2631 *arg1p = value_ind (value_cast (lookup_pointer_type (type),
2632 value_addr (*arg1p)));
2634 /* Move the `this' pointer according to the offset.
2635 VALUE_OFFSET (*arg1p) += offset; */
2643 /* Helper function for both unpack_value_bits_as_long and
2644 unpack_bits_as_long. See those functions for more details on the
2645 interface; the only difference is that this function accepts either
2646 a NULL or a non-NULL ORIGINAL_VALUE. */
2649 unpack_value_bits_as_long_1 (struct type *field_type, const gdb_byte *valaddr,
2650 int embedded_offset, int bitpos, int bitsize,
2651 const struct value *original_value,
2654 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
2661 /* Read the minimum number of bytes required; there may not be
2662 enough bytes to read an entire ULONGEST. */
2663 CHECK_TYPEDEF (field_type);
2665 bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
2667 bytes_read = TYPE_LENGTH (field_type);
2669 read_offset = bitpos / 8;
2671 if (original_value != NULL
2672 && !value_bytes_available (original_value, embedded_offset + read_offset,
2676 val = extract_unsigned_integer (valaddr + embedded_offset + read_offset,
2677 bytes_read, byte_order);
2679 /* Extract bits. See comment above. */
2681 if (gdbarch_bits_big_endian (get_type_arch (field_type)))
2682 lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
2684 lsbcount = (bitpos % 8);
2687 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2688 If the field is signed, and is negative, then sign extend. */
2690 if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
2692 valmask = (((ULONGEST) 1) << bitsize) - 1;
2694 if (!TYPE_UNSIGNED (field_type))
2696 if (val & (valmask ^ (valmask >> 1)))
2707 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2708 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2709 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2710 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2713 Returns false if the value contents are unavailable, otherwise
2714 returns true, indicating a valid value has been stored in *RESULT.
2716 Extracting bits depends on endianness of the machine. Compute the
2717 number of least significant bits to discard. For big endian machines,
2718 we compute the total number of bits in the anonymous object, subtract
2719 off the bit count from the MSB of the object to the MSB of the
2720 bitfield, then the size of the bitfield, which leaves the LSB discard
2721 count. For little endian machines, the discard count is simply the
2722 number of bits from the LSB of the anonymous object to the LSB of the
2725 If the field is signed, we also do sign extension. */
2728 unpack_value_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
2729 int embedded_offset, int bitpos, int bitsize,
2730 const struct value *original_value,
2733 gdb_assert (original_value != NULL);
2735 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2736 bitpos, bitsize, original_value, result);
2740 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2741 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2742 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2746 unpack_value_field_as_long_1 (struct type *type, const gdb_byte *valaddr,
2747 int embedded_offset, int fieldno,
2748 const struct value *val, LONGEST *result)
2750 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
2751 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
2752 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2754 return unpack_value_bits_as_long_1 (field_type, valaddr, embedded_offset,
2755 bitpos, bitsize, val,
2759 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2760 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2761 ORIGINAL_VALUE, which must not be NULL. See
2762 unpack_value_bits_as_long for more details. */
2765 unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
2766 int embedded_offset, int fieldno,
2767 const struct value *val, LONGEST *result)
2769 gdb_assert (val != NULL);
2771 return unpack_value_field_as_long_1 (type, valaddr, embedded_offset,
2772 fieldno, val, result);
2775 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2776 object at VALADDR. See unpack_value_bits_as_long for more details.
2777 This function differs from unpack_value_field_as_long in that it
2778 operates without a struct value object. */
2781 unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
2785 unpack_value_field_as_long_1 (type, valaddr, 0, fieldno, NULL, &result);
2789 /* Return a new value with type TYPE, which is FIELDNO field of the
2790 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2791 of VAL. If the VAL's contents required to extract the bitfield
2792 from are unavailable, the new value is correspondingly marked as
2796 value_field_bitfield (struct type *type, int fieldno,
2797 const gdb_byte *valaddr,
2798 int embedded_offset, const struct value *val)
2802 if (!unpack_value_field_as_long (type, valaddr, embedded_offset, fieldno,
2805 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
2806 struct value *retval = allocate_value (field_type);
2807 mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (field_type));
2812 return value_from_longest (TYPE_FIELD_TYPE (type, fieldno), l);
2816 /* Modify the value of a bitfield. ADDR points to a block of memory in
2817 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2818 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2819 indicate which bits (in target bit order) comprise the bitfield.
2820 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2821 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2824 modify_field (struct type *type, gdb_byte *addr,
2825 LONGEST fieldval, int bitpos, int bitsize)
2827 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2829 ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
2832 /* Normalize BITPOS. */
2836 /* If a negative fieldval fits in the field in question, chop
2837 off the sign extension bits. */
2838 if ((~fieldval & ~(mask >> 1)) == 0)
2841 /* Warn if value is too big to fit in the field in question. */
2842 if (0 != (fieldval & ~mask))
2844 /* FIXME: would like to include fieldval in the message, but
2845 we don't have a sprintf_longest. */
2846 warning (_("Value does not fit in %d bits."), bitsize);
2848 /* Truncate it, otherwise adjoining fields may be corrupted. */
2852 /* Ensure no bytes outside of the modified ones get accessed as it may cause
2853 false valgrind reports. */
2855 bytesize = (bitpos + bitsize + 7) / 8;
2856 oword = extract_unsigned_integer (addr, bytesize, byte_order);
2858 /* Shifting for bit field depends on endianness of the target machine. */
2859 if (gdbarch_bits_big_endian (get_type_arch (type)))
2860 bitpos = bytesize * 8 - bitpos - bitsize;
2862 oword &= ~(mask << bitpos);
2863 oword |= fieldval << bitpos;
2865 store_unsigned_integer (addr, bytesize, byte_order, oword);
2868 /* Pack NUM into BUF using a target format of TYPE. */
2871 pack_long (gdb_byte *buf, struct type *type, LONGEST num)
2873 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2876 type = check_typedef (type);
2877 len = TYPE_LENGTH (type);
2879 switch (TYPE_CODE (type))
2882 case TYPE_CODE_CHAR:
2883 case TYPE_CODE_ENUM:
2884 case TYPE_CODE_FLAGS:
2885 case TYPE_CODE_BOOL:
2886 case TYPE_CODE_RANGE:
2887 case TYPE_CODE_MEMBERPTR:
2888 store_signed_integer (buf, len, byte_order, num);
2893 store_typed_address (buf, type, (CORE_ADDR) num);
2897 error (_("Unexpected type (%d) encountered for integer constant."),
2903 /* Pack NUM into BUF using a target format of TYPE. */
2906 pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
2909 enum bfd_endian byte_order;
2911 type = check_typedef (type);
2912 len = TYPE_LENGTH (type);
2913 byte_order = gdbarch_byte_order (get_type_arch (type));
2915 switch (TYPE_CODE (type))
2918 case TYPE_CODE_CHAR:
2919 case TYPE_CODE_ENUM:
2920 case TYPE_CODE_FLAGS:
2921 case TYPE_CODE_BOOL:
2922 case TYPE_CODE_RANGE:
2923 case TYPE_CODE_MEMBERPTR:
2924 store_unsigned_integer (buf, len, byte_order, num);
2929 store_typed_address (buf, type, (CORE_ADDR) num);
2933 error (_("Unexpected type (%d) encountered "
2934 "for unsigned integer constant."),
2940 /* Convert C numbers into newly allocated values. */
2943 value_from_longest (struct type *type, LONGEST num)
2945 struct value *val = allocate_value (type);
2947 pack_long (value_contents_raw (val), type, num);
2952 /* Convert C unsigned numbers into newly allocated values. */
2955 value_from_ulongest (struct type *type, ULONGEST num)
2957 struct value *val = allocate_value (type);
2959 pack_unsigned_long (value_contents_raw (val), type, num);
2965 /* Create a value representing a pointer of type TYPE to the address
2968 value_from_pointer (struct type *type, CORE_ADDR addr)
2970 struct value *val = allocate_value (type);
2972 store_typed_address (value_contents_raw (val), check_typedef (type), addr);
2977 /* Create a value of type TYPE whose contents come from VALADDR, if it
2978 is non-null, and whose memory address (in the inferior) is
2982 value_from_contents_and_address (struct type *type,
2983 const gdb_byte *valaddr,
2988 if (valaddr == NULL)
2989 v = allocate_value_lazy (type);
2992 v = allocate_value (type);
2993 memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type));
2995 set_value_address (v, address);
2996 VALUE_LVAL (v) = lval_memory;
3000 /* Create a value of type TYPE holding the contents CONTENTS.
3001 The new value is `not_lval'. */
3004 value_from_contents (struct type *type, const gdb_byte *contents)
3006 struct value *result;
3008 result = allocate_value (type);
3009 memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type));
3014 value_from_double (struct type *type, DOUBLEST num)
3016 struct value *val = allocate_value (type);
3017 struct type *base_type = check_typedef (type);
3018 enum type_code code = TYPE_CODE (base_type);
3020 if (code == TYPE_CODE_FLT)
3022 store_typed_floating (value_contents_raw (val), base_type, num);
3025 error (_("Unexpected type encountered for floating constant."));
3031 value_from_decfloat (struct type *type, const gdb_byte *dec)
3033 struct value *val = allocate_value (type);
3035 memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
3039 /* Extract a value from the history file. Input will be of the form
3040 $digits or $$digits. See block comment above 'write_dollar_variable'
3044 value_from_history_ref (char *h, char **endp)
3056 /* Find length of numeral string. */
3057 for (; isdigit (h[len]); len++)
3060 /* Make sure numeral string is not part of an identifier. */
3061 if (h[len] == '_' || isalpha (h[len]))
3064 /* Now collect the index value. */
3069 /* For some bizarre reason, "$$" is equivalent to "$$1",
3070 rather than to "$$0" as it ought to be! */
3075 index = -strtol (&h[2], endp, 10);
3081 /* "$" is equivalent to "$0". */
3086 index = strtol (&h[1], endp, 10);
3089 return access_value_history (index);
3093 coerce_ref_if_computed (const struct value *arg)
3095 const struct lval_funcs *funcs;
3097 if (TYPE_CODE (check_typedef (value_type (arg))) != TYPE_CODE_REF)
3100 if (value_lval_const (arg) != lval_computed)
3103 funcs = value_computed_funcs (arg);
3104 if (funcs->coerce_ref == NULL)
3107 return funcs->coerce_ref (arg);
3111 coerce_ref (struct value *arg)
3113 struct type *value_type_arg_tmp = check_typedef (value_type (arg));
3114 struct value *retval;
3116 retval = coerce_ref_if_computed (arg);
3120 if (TYPE_CODE (value_type_arg_tmp) != TYPE_CODE_REF)
3123 return value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),
3124 unpack_pointer (value_type (arg),
3125 value_contents (arg)));
3129 coerce_array (struct value *arg)
3133 arg = coerce_ref (arg);
3134 type = check_typedef (value_type (arg));
3136 switch (TYPE_CODE (type))
3138 case TYPE_CODE_ARRAY:
3139 if (!TYPE_VECTOR (type) && current_language->c_style_arrays)
3140 arg = value_coerce_array (arg);
3142 case TYPE_CODE_FUNC:
3143 arg = value_coerce_function (arg);
3150 /* Return true if the function returning the specified type is using
3151 the convention of returning structures in memory (passing in the
3152 address as a hidden first parameter). */
3155 using_struct_return (struct gdbarch *gdbarch,
3156 struct type *func_type, struct type *value_type)
3158 enum type_code code = TYPE_CODE (value_type);
3160 if (code == TYPE_CODE_ERROR)
3161 error (_("Function return type unknown."));
3163 if (code == TYPE_CODE_VOID)
3164 /* A void return value is never in memory. See also corresponding
3165 code in "print_return_value". */
3168 /* Probe the architecture for the return-value convention. */
3169 return (gdbarch_return_value (gdbarch, func_type, value_type,
3171 != RETURN_VALUE_REGISTER_CONVENTION);
3174 /* Set the initialized field in a value struct. */
3177 set_value_initialized (struct value *val, int status)
3179 val->initialized = status;
3182 /* Return the initialized field in a value struct. */
3185 value_initialized (struct value *val)
3187 return val->initialized;
3191 _initialize_values (void)
3193 add_cmd ("convenience", no_class, show_convenience, _("\
3194 Debugger convenience (\"$foo\") variables.\n\
3195 These variables are created when you assign them values;\n\
3196 thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3198 A few convenience variables are given values automatically:\n\
3199 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3200 \"$__\" holds the contents of the last address examined with \"x\"."),
3203 add_cmd ("values", no_set_class, show_values, _("\
3204 Elements of value history around item number IDX (or last ten)."),
3207 add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
3208 Initialize a convenience variable if necessary.\n\
3209 init-if-undefined VARIABLE = EXPRESSION\n\
3210 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3211 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3212 VARIABLE is already initialized."));
3214 add_prefix_cmd ("function", no_class, function_command, _("\
3215 Placeholder command for showing help on convenience functions."),
3216 &functionlist, "function ", 0, &cmdlist);