1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2015 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"
37 #include "cli/cli-decode.h"
38 #include "extension.h"
40 #include "tracepoint.h"
42 #include "user-regs.h"
44 /* Prototypes for exported functions. */
46 void _initialize_values (void);
48 /* Definition of a user function. */
49 struct internal_function
51 /* The name of the function. It is a bit odd to have this in the
52 function itself -- the user might use a differently-named
53 convenience variable to hold the function. */
57 internal_function_fn handler;
59 /* User data for the handler. */
63 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
67 /* Lowest offset in the range. */
70 /* Length of the range. */
74 typedef struct range range_s;
78 /* Returns true if the ranges defined by [offset1, offset1+len1) and
79 [offset2, offset2+len2) overlap. */
82 ranges_overlap (int offset1, int len1,
83 int offset2, int len2)
87 l = max (offset1, offset2);
88 h = min (offset1 + len1, offset2 + len2);
92 /* Returns true if the first argument is strictly less than the
93 second, useful for VEC_lower_bound. We keep ranges sorted by
94 offset and coalesce overlapping and contiguous ranges, so this just
95 compares the starting offset. */
98 range_lessthan (const range_s *r1, const range_s *r2)
100 return r1->offset < r2->offset;
103 /* Returns true if RANGES contains any range that overlaps [OFFSET,
107 ranges_contain (VEC(range_s) *ranges, int offset, int length)
112 what.offset = offset;
113 what.length = length;
115 /* We keep ranges sorted by offset and coalesce overlapping and
116 contiguous ranges, so to check if a range list contains a given
117 range, we can do a binary search for the position the given range
118 would be inserted if we only considered the starting OFFSET of
119 ranges. We call that position I. Since we also have LENGTH to
120 care for (this is a range afterall), we need to check if the
121 _previous_ range overlaps the I range. E.g.,
125 |---| |---| |------| ... |--|
130 In the case above, the binary search would return `I=1', meaning,
131 this OFFSET should be inserted at position 1, and the current
132 position 1 should be pushed further (and before 2). But, `0'
135 Then we need to check if the I range overlaps the I range itself.
140 |---| |---| |-------| ... |--|
146 i = VEC_lower_bound (range_s, ranges, &what, range_lessthan);
150 struct range *bef = VEC_index (range_s, ranges, i - 1);
152 if (ranges_overlap (bef->offset, bef->length, offset, length))
156 if (i < VEC_length (range_s, ranges))
158 struct range *r = VEC_index (range_s, ranges, i);
160 if (ranges_overlap (r->offset, r->length, offset, length))
167 static struct cmd_list_element *functionlist;
169 /* Note that the fields in this structure are arranged to save a bit
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. */
179 unsigned int modifiable : 1;
181 /* If zero, contents of this value are in the contents field. If
182 nonzero, contents are in inferior. If the lval field is lval_memory,
183 the contents are in inferior memory at location.address plus offset.
184 The lval field may also be lval_register.
186 WARNING: This field is used by the code which handles watchpoints
187 (see breakpoint.c) to decide whether a particular value can be
188 watched by hardware watchpoints. If the lazy flag is set for
189 some member of a value chain, it is assumed that this member of
190 the chain doesn't need to be watched as part of watching the
191 value itself. This is how GDB avoids watching the entire struct
192 or array when the user wants to watch a single struct member or
193 array element. If you ever change the way lazy flag is set and
194 reset, be sure to consider this use as well! */
195 unsigned int lazy : 1;
197 /* If value is a variable, is it initialized or not. */
198 unsigned int initialized : 1;
200 /* If value is from the stack. If this is set, read_stack will be
201 used instead of read_memory to enable extra caching. */
202 unsigned int stack : 1;
204 /* If the value has been released. */
205 unsigned int released : 1;
207 /* Register number if the value is from a register. */
210 /* Location of value (if lval). */
213 /* If lval == lval_memory, this is the address in the inferior.
214 If lval == lval_register, this is the byte offset into the
215 registers structure. */
218 /* Pointer to internal variable. */
219 struct internalvar *internalvar;
221 /* Pointer to xmethod worker. */
222 struct xmethod_worker *xm_worker;
224 /* If lval == lval_computed, this is a set of function pointers
225 to use to access and describe the value, and a closure pointer
229 /* Functions to call. */
230 const struct lval_funcs *funcs;
232 /* Closure for those functions to use. */
237 /* Describes offset of a value within lval of a structure in target
238 addressable memory units. If lval == lval_memory, this is an offset to
239 the address. If lval == lval_register, this is a further offset from
240 location.address within the registers structure. Note also the member
241 embedded_offset below. */
244 /* Only used for bitfields; number of bits contained in them. */
247 /* Only used for bitfields; position of start of field. For
248 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
249 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
252 /* The number of references to this value. When a value is created,
253 the value chain holds a reference, so REFERENCE_COUNT is 1. If
254 release_value is called, this value is removed from the chain but
255 the caller of release_value now has a reference to this value.
256 The caller must arrange for a call to value_free later. */
259 /* Only used for bitfields; the containing value. This allows a
260 single read from the target when displaying multiple
262 struct value *parent;
264 /* Frame register value is relative to. This will be described in
265 the lval enum above as "lval_register". */
266 struct frame_id frame_id;
268 /* Type of the value. */
271 /* If a value represents a C++ object, then the `type' field gives
272 the object's compile-time type. If the object actually belongs
273 to some class derived from `type', perhaps with other base
274 classes and additional members, then `type' is just a subobject
275 of the real thing, and the full object is probably larger than
276 `type' would suggest.
278 If `type' is a dynamic class (i.e. one with a vtable), then GDB
279 can actually determine the object's run-time type by looking at
280 the run-time type information in the vtable. When this
281 information is available, we may elect to read in the entire
282 object, for several reasons:
284 - When printing the value, the user would probably rather see the
285 full object, not just the limited portion apparent from the
288 - If `type' has virtual base classes, then even printing `type'
289 alone may require reaching outside the `type' portion of the
290 object to wherever the virtual base class has been stored.
292 When we store the entire object, `enclosing_type' is the run-time
293 type -- the complete object -- and `embedded_offset' is the
294 offset of `type' within that larger type, in target addressable memory
295 units. The value_contents() macro takes `embedded_offset' into account,
296 so most GDB code continues to see the `type' portion of the value, just
297 as the inferior would.
299 If `type' is a pointer to an object, then `enclosing_type' is a
300 pointer to the object's run-time type, and `pointed_to_offset' is
301 the offset in target addressable memory units from the full object
302 to the pointed-to object -- that is, the value `embedded_offset' would
303 have if we followed the pointer and fetched the complete object.
304 (I don't really see the point. Why not just determine the
305 run-time type when you indirect, and avoid the special case? The
306 contents don't matter until you indirect anyway.)
308 If we're not doing anything fancy, `enclosing_type' is equal to
309 `type', and `embedded_offset' is zero, so everything works
311 struct type *enclosing_type;
313 int pointed_to_offset;
315 /* Values are stored in a chain, so that they can be deleted easily
316 over calls to the inferior. Values assigned to internal
317 variables, put into the value history or exposed to Python are
318 taken off this list. */
321 /* Actual contents of the value. Target byte-order. NULL or not
322 valid if lazy is nonzero. */
325 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
326 rather than available, since the common and default case is for a
327 value to be available. This is filled in at value read time.
328 The unavailable ranges are tracked in bits. Note that a contents
329 bit that has been optimized out doesn't really exist in the
330 program, so it can't be marked unavailable either. */
331 VEC(range_s) *unavailable;
333 /* Likewise, but for optimized out contents (a chunk of the value of
334 a variable that does not actually exist in the program). If LVAL
335 is lval_register, this is a register ($pc, $sp, etc., never a
336 program variable) that has not been saved in the frame. Not
337 saved registers and optimized-out program variables values are
338 treated pretty much the same, except not-saved registers have a
339 different string representation and related error strings. */
340 VEC(range_s) *optimized_out;
344 value_bits_available (const struct value *value, int offset, int length)
346 gdb_assert (!value->lazy);
348 return !ranges_contain (value->unavailable, offset, length);
352 value_bytes_available (const struct value *value, int offset, int length)
354 return value_bits_available (value,
355 offset * TARGET_CHAR_BIT,
356 length * TARGET_CHAR_BIT);
360 value_bits_any_optimized_out (const struct value *value, int bit_offset, int bit_length)
362 gdb_assert (!value->lazy);
364 return ranges_contain (value->optimized_out, bit_offset, bit_length);
368 value_entirely_available (struct value *value)
370 /* We can only tell whether the whole value is available when we try
373 value_fetch_lazy (value);
375 if (VEC_empty (range_s, value->unavailable))
380 /* Returns true if VALUE is entirely covered by RANGES. If the value
381 is lazy, it'll be read now. Note that RANGE is a pointer to
382 pointer because reading the value might change *RANGE. */
385 value_entirely_covered_by_range_vector (struct value *value,
386 VEC(range_s) **ranges)
388 /* We can only tell whether the whole value is optimized out /
389 unavailable when we try to read it. */
391 value_fetch_lazy (value);
393 if (VEC_length (range_s, *ranges) == 1)
395 struct range *t = VEC_index (range_s, *ranges, 0);
398 && t->length == (TARGET_CHAR_BIT
399 * TYPE_LENGTH (value_enclosing_type (value))))
407 value_entirely_unavailable (struct value *value)
409 return value_entirely_covered_by_range_vector (value, &value->unavailable);
413 value_entirely_optimized_out (struct value *value)
415 return value_entirely_covered_by_range_vector (value, &value->optimized_out);
418 /* Insert into the vector pointed to by VECTORP the bit range starting of
419 OFFSET bits, and extending for the next LENGTH bits. */
422 insert_into_bit_range_vector (VEC(range_s) **vectorp, int offset, int length)
427 /* Insert the range sorted. If there's overlap or the new range
428 would be contiguous with an existing range, merge. */
430 newr.offset = offset;
431 newr.length = length;
433 /* Do a binary search for the position the given range would be
434 inserted if we only considered the starting OFFSET of ranges.
435 Call that position I. Since we also have LENGTH to care for
436 (this is a range afterall), we need to check if the _previous_
437 range overlaps the I range. E.g., calling R the new range:
439 #1 - overlaps with previous
443 |---| |---| |------| ... |--|
448 In the case #1 above, the binary search would return `I=1',
449 meaning, this OFFSET should be inserted at position 1, and the
450 current position 1 should be pushed further (and become 2). But,
451 note that `0' overlaps with R, so we want to merge them.
453 A similar consideration needs to be taken if the new range would
454 be contiguous with the previous range:
456 #2 - contiguous with previous
460 |--| |---| |------| ... |--|
465 If there's no overlap with the previous range, as in:
467 #3 - not overlapping and not contiguous
471 |--| |---| |------| ... |--|
478 #4 - R is the range with lowest offset
482 |--| |---| |------| ... |--|
487 ... we just push the new range to I.
489 All the 4 cases above need to consider that the new range may
490 also overlap several of the ranges that follow, or that R may be
491 contiguous with the following range, and merge. E.g.,
493 #5 - overlapping following ranges
496 |------------------------|
497 |--| |---| |------| ... |--|
506 |--| |---| |------| ... |--|
513 i = VEC_lower_bound (range_s, *vectorp, &newr, range_lessthan);
516 struct range *bef = VEC_index (range_s, *vectorp, i - 1);
518 if (ranges_overlap (bef->offset, bef->length, offset, length))
521 ULONGEST l = min (bef->offset, offset);
522 ULONGEST h = max (bef->offset + bef->length, offset + length);
528 else if (offset == bef->offset + bef->length)
531 bef->length += length;
537 VEC_safe_insert (range_s, *vectorp, i, &newr);
543 VEC_safe_insert (range_s, *vectorp, i, &newr);
546 /* Check whether the ranges following the one we've just added or
547 touched can be folded in (#5 above). */
548 if (i + 1 < VEC_length (range_s, *vectorp))
555 /* Get the range we just touched. */
556 t = VEC_index (range_s, *vectorp, i);
560 for (; VEC_iterate (range_s, *vectorp, i, r); i++)
561 if (r->offset <= t->offset + t->length)
565 l = min (t->offset, r->offset);
566 h = max (t->offset + t->length, r->offset + r->length);
575 /* If we couldn't merge this one, we won't be able to
576 merge following ones either, since the ranges are
577 always sorted by OFFSET. */
582 VEC_block_remove (range_s, *vectorp, next, removed);
587 mark_value_bits_unavailable (struct value *value, int offset, int length)
589 insert_into_bit_range_vector (&value->unavailable, offset, length);
593 mark_value_bytes_unavailable (struct value *value, int offset, int length)
595 mark_value_bits_unavailable (value,
596 offset * TARGET_CHAR_BIT,
597 length * TARGET_CHAR_BIT);
600 /* Find the first range in RANGES that overlaps the range defined by
601 OFFSET and LENGTH, starting at element POS in the RANGES vector,
602 Returns the index into RANGES where such overlapping range was
603 found, or -1 if none was found. */
606 find_first_range_overlap (VEC(range_s) *ranges, int pos,
607 int offset, int length)
612 for (i = pos; VEC_iterate (range_s, ranges, i, r); i++)
613 if (ranges_overlap (r->offset, r->length, offset, length))
619 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
620 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
623 It must always be the case that:
624 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
626 It is assumed that memory can be accessed from:
627 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
629 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
630 / TARGET_CHAR_BIT) */
632 memcmp_with_bit_offsets (const gdb_byte *ptr1, size_t offset1_bits,
633 const gdb_byte *ptr2, size_t offset2_bits,
636 gdb_assert (offset1_bits % TARGET_CHAR_BIT
637 == offset2_bits % TARGET_CHAR_BIT);
639 if (offset1_bits % TARGET_CHAR_BIT != 0)
642 gdb_byte mask, b1, b2;
644 /* The offset from the base pointers PTR1 and PTR2 is not a complete
645 number of bytes. A number of bits up to either the next exact
646 byte boundary, or LENGTH_BITS (which ever is sooner) will be
648 bits = TARGET_CHAR_BIT - offset1_bits % TARGET_CHAR_BIT;
649 gdb_assert (bits < sizeof (mask) * TARGET_CHAR_BIT);
650 mask = (1 << bits) - 1;
652 if (length_bits < bits)
654 mask &= ~(gdb_byte) ((1 << (bits - length_bits)) - 1);
658 /* Now load the two bytes and mask off the bits we care about. */
659 b1 = *(ptr1 + offset1_bits / TARGET_CHAR_BIT) & mask;
660 b2 = *(ptr2 + offset2_bits / TARGET_CHAR_BIT) & mask;
665 /* Now update the length and offsets to take account of the bits
666 we've just compared. */
668 offset1_bits += bits;
669 offset2_bits += bits;
672 if (length_bits % TARGET_CHAR_BIT != 0)
676 gdb_byte mask, b1, b2;
678 /* The length is not an exact number of bytes. After the previous
679 IF.. block then the offsets are byte aligned, or the
680 length is zero (in which case this code is not reached). Compare
681 a number of bits at the end of the region, starting from an exact
683 bits = length_bits % TARGET_CHAR_BIT;
684 o1 = offset1_bits + length_bits - bits;
685 o2 = offset2_bits + length_bits - bits;
687 gdb_assert (bits < sizeof (mask) * TARGET_CHAR_BIT);
688 mask = ((1 << bits) - 1) << (TARGET_CHAR_BIT - bits);
690 gdb_assert (o1 % TARGET_CHAR_BIT == 0);
691 gdb_assert (o2 % TARGET_CHAR_BIT == 0);
693 b1 = *(ptr1 + o1 / TARGET_CHAR_BIT) & mask;
694 b2 = *(ptr2 + o2 / TARGET_CHAR_BIT) & mask;
704 /* We've now taken care of any stray "bits" at the start, or end of
705 the region to compare, the remainder can be covered with a simple
707 gdb_assert (offset1_bits % TARGET_CHAR_BIT == 0);
708 gdb_assert (offset2_bits % TARGET_CHAR_BIT == 0);
709 gdb_assert (length_bits % TARGET_CHAR_BIT == 0);
711 return memcmp (ptr1 + offset1_bits / TARGET_CHAR_BIT,
712 ptr2 + offset2_bits / TARGET_CHAR_BIT,
713 length_bits / TARGET_CHAR_BIT);
716 /* Length is zero, regions match. */
720 /* Helper struct for find_first_range_overlap_and_match and
721 value_contents_bits_eq. Keep track of which slot of a given ranges
722 vector have we last looked at. */
724 struct ranges_and_idx
727 VEC(range_s) *ranges;
729 /* The range we've last found in RANGES. Given ranges are sorted,
730 we can start the next lookup here. */
734 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
735 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
736 ranges starting at OFFSET2 bits. Return true if the ranges match
737 and fill in *L and *H with the overlapping window relative to
738 (both) OFFSET1 or OFFSET2. */
741 find_first_range_overlap_and_match (struct ranges_and_idx *rp1,
742 struct ranges_and_idx *rp2,
743 int offset1, int offset2,
744 int length, ULONGEST *l, ULONGEST *h)
746 rp1->idx = find_first_range_overlap (rp1->ranges, rp1->idx,
748 rp2->idx = find_first_range_overlap (rp2->ranges, rp2->idx,
751 if (rp1->idx == -1 && rp2->idx == -1)
757 else if (rp1->idx == -1 || rp2->idx == -1)
765 r1 = VEC_index (range_s, rp1->ranges, rp1->idx);
766 r2 = VEC_index (range_s, rp2->ranges, rp2->idx);
768 /* Get the unavailable windows intersected by the incoming
769 ranges. The first and last ranges that overlap the argument
770 range may be wider than said incoming arguments ranges. */
771 l1 = max (offset1, r1->offset);
772 h1 = min (offset1 + length, r1->offset + r1->length);
774 l2 = max (offset2, r2->offset);
775 h2 = min (offset2 + length, offset2 + r2->length);
777 /* Make them relative to the respective start offsets, so we can
778 compare them for equality. */
785 /* Different ranges, no match. */
786 if (l1 != l2 || h1 != h2)
795 /* Helper function for value_contents_eq. The only difference is that
796 this function is bit rather than byte based.
798 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
799 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
800 Return true if the available bits match. */
803 value_contents_bits_eq (const struct value *val1, int offset1,
804 const struct value *val2, int offset2,
807 /* Each array element corresponds to a ranges source (unavailable,
808 optimized out). '1' is for VAL1, '2' for VAL2. */
809 struct ranges_and_idx rp1[2], rp2[2];
811 /* See function description in value.h. */
812 gdb_assert (!val1->lazy && !val2->lazy);
814 /* We shouldn't be trying to compare past the end of the values. */
815 gdb_assert (offset1 + length
816 <= TYPE_LENGTH (val1->enclosing_type) * TARGET_CHAR_BIT);
817 gdb_assert (offset2 + length
818 <= TYPE_LENGTH (val2->enclosing_type) * TARGET_CHAR_BIT);
820 memset (&rp1, 0, sizeof (rp1));
821 memset (&rp2, 0, sizeof (rp2));
822 rp1[0].ranges = val1->unavailable;
823 rp2[0].ranges = val2->unavailable;
824 rp1[1].ranges = val1->optimized_out;
825 rp2[1].ranges = val2->optimized_out;
829 ULONGEST l = 0, h = 0; /* init for gcc -Wall */
832 for (i = 0; i < 2; i++)
834 ULONGEST l_tmp, h_tmp;
836 /* The contents only match equal if the invalid/unavailable
837 contents ranges match as well. */
838 if (!find_first_range_overlap_and_match (&rp1[i], &rp2[i],
839 offset1, offset2, length,
843 /* We're interested in the lowest/first range found. */
844 if (i == 0 || l_tmp < l)
851 /* Compare the available/valid contents. */
852 if (memcmp_with_bit_offsets (val1->contents, offset1,
853 val2->contents, offset2, l) != 0)
865 value_contents_eq (const struct value *val1, int offset1,
866 const struct value *val2, int offset2,
869 return value_contents_bits_eq (val1, offset1 * TARGET_CHAR_BIT,
870 val2, offset2 * TARGET_CHAR_BIT,
871 length * TARGET_CHAR_BIT);
874 /* Prototypes for local functions. */
876 static void show_values (char *, int);
878 static void show_convenience (char *, int);
881 /* The value-history records all the values printed
882 by print commands during this session. Each chunk
883 records 60 consecutive values. The first chunk on
884 the chain records the most recent values.
885 The total number of values is in value_history_count. */
887 #define VALUE_HISTORY_CHUNK 60
889 struct value_history_chunk
891 struct value_history_chunk *next;
892 struct value *values[VALUE_HISTORY_CHUNK];
895 /* Chain of chunks now in use. */
897 static struct value_history_chunk *value_history_chain;
899 static int value_history_count; /* Abs number of last entry stored. */
902 /* List of all value objects currently allocated
903 (except for those released by calls to release_value)
904 This is so they can be freed after each command. */
906 static struct value *all_values;
908 /* Allocate a lazy value for type TYPE. Its actual content is
909 "lazily" allocated too: the content field of the return value is
910 NULL; it will be allocated when it is fetched from the target. */
913 allocate_value_lazy (struct type *type)
917 /* Call check_typedef on our type to make sure that, if TYPE
918 is a TYPE_CODE_TYPEDEF, its length is set to the length
919 of the target type instead of zero. However, we do not
920 replace the typedef type by the target type, because we want
921 to keep the typedef in order to be able to set the VAL's type
922 description correctly. */
923 check_typedef (type);
925 val = (struct value *) xzalloc (sizeof (struct value));
926 val->contents = NULL;
927 val->next = all_values;
930 val->enclosing_type = type;
931 VALUE_LVAL (val) = not_lval;
932 val->location.address = 0;
933 VALUE_FRAME_ID (val) = null_frame_id;
937 VALUE_REGNUM (val) = -1;
939 val->embedded_offset = 0;
940 val->pointed_to_offset = 0;
942 val->initialized = 1; /* Default to initialized. */
944 /* Values start out on the all_values chain. */
945 val->reference_count = 1;
950 /* Allocate the contents of VAL if it has not been allocated yet. */
953 allocate_value_contents (struct value *val)
956 val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
959 /* Allocate a value and its contents for type TYPE. */
962 allocate_value (struct type *type)
964 struct value *val = allocate_value_lazy (type);
966 allocate_value_contents (val);
971 /* Allocate a value that has the correct length
972 for COUNT repetitions of type TYPE. */
975 allocate_repeat_value (struct type *type, int count)
977 int low_bound = current_language->string_lower_bound; /* ??? */
978 /* FIXME-type-allocation: need a way to free this type when we are
980 struct type *array_type
981 = lookup_array_range_type (type, low_bound, count + low_bound - 1);
983 return allocate_value (array_type);
987 allocate_computed_value (struct type *type,
988 const struct lval_funcs *funcs,
991 struct value *v = allocate_value_lazy (type);
993 VALUE_LVAL (v) = lval_computed;
994 v->location.computed.funcs = funcs;
995 v->location.computed.closure = closure;
1000 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1003 allocate_optimized_out_value (struct type *type)
1005 struct value *retval = allocate_value_lazy (type);
1007 mark_value_bytes_optimized_out (retval, 0, TYPE_LENGTH (type));
1008 set_value_lazy (retval, 0);
1012 /* Accessor methods. */
1015 value_next (struct value *value)
1021 value_type (const struct value *value)
1026 deprecated_set_value_type (struct value *value, struct type *type)
1032 value_offset (const struct value *value)
1034 return value->offset;
1037 set_value_offset (struct value *value, int offset)
1039 value->offset = offset;
1043 value_bitpos (const struct value *value)
1045 return value->bitpos;
1048 set_value_bitpos (struct value *value, int bit)
1050 value->bitpos = bit;
1054 value_bitsize (const struct value *value)
1056 return value->bitsize;
1059 set_value_bitsize (struct value *value, int bit)
1061 value->bitsize = bit;
1065 value_parent (struct value *value)
1067 return value->parent;
1073 set_value_parent (struct value *value, struct value *parent)
1075 struct value *old = value->parent;
1077 value->parent = parent;
1079 value_incref (parent);
1084 value_contents_raw (struct value *value)
1086 allocate_value_contents (value);
1087 return value->contents + value->embedded_offset;
1091 value_contents_all_raw (struct value *value)
1093 allocate_value_contents (value);
1094 return value->contents;
1098 value_enclosing_type (struct value *value)
1100 return value->enclosing_type;
1103 /* Look at value.h for description. */
1106 value_actual_type (struct value *value, int resolve_simple_types,
1107 int *real_type_found)
1109 struct value_print_options opts;
1110 struct type *result;
1112 get_user_print_options (&opts);
1114 if (real_type_found)
1115 *real_type_found = 0;
1116 result = value_type (value);
1117 if (opts.objectprint)
1119 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1120 fetch its rtti type. */
1121 if ((TYPE_CODE (result) == TYPE_CODE_PTR
1122 || TYPE_CODE (result) == TYPE_CODE_REF)
1123 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result)))
1124 == TYPE_CODE_STRUCT)
1126 struct type *real_type;
1128 real_type = value_rtti_indirect_type (value, NULL, NULL, NULL);
1131 if (real_type_found)
1132 *real_type_found = 1;
1136 else if (resolve_simple_types)
1138 if (real_type_found)
1139 *real_type_found = 1;
1140 result = value_enclosing_type (value);
1148 error_value_optimized_out (void)
1150 error (_("value has been optimized out"));
1154 require_not_optimized_out (const struct value *value)
1156 if (!VEC_empty (range_s, value->optimized_out))
1158 if (value->lval == lval_register)
1159 error (_("register has not been saved in frame"));
1161 error_value_optimized_out ();
1166 require_available (const struct value *value)
1168 if (!VEC_empty (range_s, value->unavailable))
1169 throw_error (NOT_AVAILABLE_ERROR, _("value is not available"));
1173 value_contents_for_printing (struct value *value)
1176 value_fetch_lazy (value);
1177 return value->contents;
1181 value_contents_for_printing_const (const struct value *value)
1183 gdb_assert (!value->lazy);
1184 return value->contents;
1188 value_contents_all (struct value *value)
1190 const gdb_byte *result = value_contents_for_printing (value);
1191 require_not_optimized_out (value);
1192 require_available (value);
1196 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1197 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1200 ranges_copy_adjusted (VEC (range_s) **dst_range, int dst_bit_offset,
1201 VEC (range_s) *src_range, int src_bit_offset,
1207 for (i = 0; VEC_iterate (range_s, src_range, i, r); i++)
1211 l = max (r->offset, src_bit_offset);
1212 h = min (r->offset + r->length, src_bit_offset + bit_length);
1215 insert_into_bit_range_vector (dst_range,
1216 dst_bit_offset + (l - src_bit_offset),
1221 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1222 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1225 value_ranges_copy_adjusted (struct value *dst, int dst_bit_offset,
1226 const struct value *src, int src_bit_offset,
1229 ranges_copy_adjusted (&dst->unavailable, dst_bit_offset,
1230 src->unavailable, src_bit_offset,
1232 ranges_copy_adjusted (&dst->optimized_out, dst_bit_offset,
1233 src->optimized_out, src_bit_offset,
1237 /* Copy LENGTH bytes of SRC value's (all) contents
1238 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1239 contents, starting at DST_OFFSET. If unavailable contents are
1240 being copied from SRC, the corresponding DST contents are marked
1241 unavailable accordingly. Neither DST nor SRC may be lazy
1244 It is assumed the contents of DST in the [DST_OFFSET,
1245 DST_OFFSET+LENGTH) range are wholly available. */
1248 value_contents_copy_raw (struct value *dst, int dst_offset,
1249 struct value *src, int src_offset, int length)
1253 int src_bit_offset, dst_bit_offset, bit_length;
1255 /* A lazy DST would make that this copy operation useless, since as
1256 soon as DST's contents were un-lazied (by a later value_contents
1257 call, say), the contents would be overwritten. A lazy SRC would
1258 mean we'd be copying garbage. */
1259 gdb_assert (!dst->lazy && !src->lazy);
1261 /* The overwritten DST range gets unavailability ORed in, not
1262 replaced. Make sure to remember to implement replacing if it
1263 turns out actually necessary. */
1264 gdb_assert (value_bytes_available (dst, dst_offset, length));
1265 gdb_assert (!value_bits_any_optimized_out (dst,
1266 TARGET_CHAR_BIT * dst_offset,
1267 TARGET_CHAR_BIT * length));
1269 /* Copy the data. */
1270 memcpy (value_contents_all_raw (dst) + dst_offset,
1271 value_contents_all_raw (src) + src_offset,
1274 /* Copy the meta-data, adjusted. */
1275 src_bit_offset = src_offset * TARGET_CHAR_BIT;
1276 dst_bit_offset = dst_offset * TARGET_CHAR_BIT;
1277 bit_length = length * TARGET_CHAR_BIT;
1279 value_ranges_copy_adjusted (dst, dst_bit_offset,
1280 src, src_bit_offset,
1284 /* Copy LENGTH bytes of SRC value's (all) contents
1285 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1286 (all) contents, starting at DST_OFFSET. If unavailable contents
1287 are being copied from SRC, the corresponding DST contents are
1288 marked unavailable accordingly. DST must not be lazy. If SRC is
1289 lazy, it will be fetched now.
1291 It is assumed the contents of DST in the [DST_OFFSET,
1292 DST_OFFSET+LENGTH) range are wholly available. */
1295 value_contents_copy (struct value *dst, int dst_offset,
1296 struct value *src, int src_offset, int length)
1299 value_fetch_lazy (src);
1301 value_contents_copy_raw (dst, dst_offset, src, src_offset, length);
1305 value_lazy (struct value *value)
1311 set_value_lazy (struct value *value, int val)
1317 value_stack (struct value *value)
1319 return value->stack;
1323 set_value_stack (struct value *value, int val)
1329 value_contents (struct value *value)
1331 const gdb_byte *result = value_contents_writeable (value);
1332 require_not_optimized_out (value);
1333 require_available (value);
1338 value_contents_writeable (struct value *value)
1341 value_fetch_lazy (value);
1342 return value_contents_raw (value);
1346 value_optimized_out (struct value *value)
1348 /* We can only know if a value is optimized out once we have tried to
1350 if (VEC_empty (range_s, value->optimized_out) && value->lazy)
1351 value_fetch_lazy (value);
1353 return !VEC_empty (range_s, value->optimized_out);
1356 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1357 the following LENGTH bytes. */
1360 mark_value_bytes_optimized_out (struct value *value, int offset, int length)
1362 mark_value_bits_optimized_out (value,
1363 offset * TARGET_CHAR_BIT,
1364 length * TARGET_CHAR_BIT);
1370 mark_value_bits_optimized_out (struct value *value, int offset, int length)
1372 insert_into_bit_range_vector (&value->optimized_out, offset, length);
1376 value_bits_synthetic_pointer (const struct value *value,
1377 int offset, int length)
1379 if (value->lval != lval_computed
1380 || !value->location.computed.funcs->check_synthetic_pointer)
1382 return value->location.computed.funcs->check_synthetic_pointer (value,
1388 value_embedded_offset (struct value *value)
1390 return value->embedded_offset;
1394 set_value_embedded_offset (struct value *value, int val)
1396 value->embedded_offset = val;
1400 value_pointed_to_offset (struct value *value)
1402 return value->pointed_to_offset;
1406 set_value_pointed_to_offset (struct value *value, int val)
1408 value->pointed_to_offset = val;
1411 const struct lval_funcs *
1412 value_computed_funcs (const struct value *v)
1414 gdb_assert (value_lval_const (v) == lval_computed);
1416 return v->location.computed.funcs;
1420 value_computed_closure (const struct value *v)
1422 gdb_assert (v->lval == lval_computed);
1424 return v->location.computed.closure;
1428 deprecated_value_lval_hack (struct value *value)
1430 return &value->lval;
1434 value_lval_const (const struct value *value)
1440 value_address (const struct value *value)
1442 if (value->lval == lval_internalvar
1443 || value->lval == lval_internalvar_component
1444 || value->lval == lval_xcallable)
1446 if (value->parent != NULL)
1447 return value_address (value->parent) + value->offset;
1449 return value->location.address + value->offset;
1453 value_raw_address (struct value *value)
1455 if (value->lval == lval_internalvar
1456 || value->lval == lval_internalvar_component
1457 || value->lval == lval_xcallable)
1459 return value->location.address;
1463 set_value_address (struct value *value, CORE_ADDR addr)
1465 gdb_assert (value->lval != lval_internalvar
1466 && value->lval != lval_internalvar_component
1467 && value->lval != lval_xcallable);
1468 value->location.address = addr;
1471 struct internalvar **
1472 deprecated_value_internalvar_hack (struct value *value)
1474 return &value->location.internalvar;
1478 deprecated_value_frame_id_hack (struct value *value)
1480 return &value->frame_id;
1484 deprecated_value_regnum_hack (struct value *value)
1486 return &value->regnum;
1490 deprecated_value_modifiable (struct value *value)
1492 return value->modifiable;
1495 /* Return a mark in the value chain. All values allocated after the
1496 mark is obtained (except for those released) are subject to being freed
1497 if a subsequent value_free_to_mark is passed the mark. */
1504 /* Take a reference to VAL. VAL will not be deallocated until all
1505 references are released. */
1508 value_incref (struct value *val)
1510 val->reference_count++;
1513 /* Release a reference to VAL, which was acquired with value_incref.
1514 This function is also called to deallocate values from the value
1518 value_free (struct value *val)
1522 gdb_assert (val->reference_count > 0);
1523 val->reference_count--;
1524 if (val->reference_count > 0)
1527 /* If there's an associated parent value, drop our reference to
1529 if (val->parent != NULL)
1530 value_free (val->parent);
1532 if (VALUE_LVAL (val) == lval_computed)
1534 const struct lval_funcs *funcs = val->location.computed.funcs;
1536 if (funcs->free_closure)
1537 funcs->free_closure (val);
1539 else if (VALUE_LVAL (val) == lval_xcallable)
1540 free_xmethod_worker (val->location.xm_worker);
1542 xfree (val->contents);
1543 VEC_free (range_s, val->unavailable);
1548 /* Free all values allocated since MARK was obtained by value_mark
1549 (except for those released). */
1551 value_free_to_mark (struct value *mark)
1556 for (val = all_values; val && val != mark; val = next)
1565 /* Free all the values that have been allocated (except for those released).
1566 Call after each command, successful or not.
1567 In practice this is called before each command, which is sufficient. */
1570 free_all_values (void)
1575 for (val = all_values; val; val = next)
1585 /* Frees all the elements in a chain of values. */
1588 free_value_chain (struct value *v)
1594 next = value_next (v);
1599 /* Remove VAL from the chain all_values
1600 so it will not be freed automatically. */
1603 release_value (struct value *val)
1607 if (all_values == val)
1609 all_values = val->next;
1615 for (v = all_values; v; v = v->next)
1619 v->next = val->next;
1627 /* If the value is not already released, release it.
1628 If the value is already released, increment its reference count.
1629 That is, this function ensures that the value is released from the
1630 value chain and that the caller owns a reference to it. */
1633 release_value_or_incref (struct value *val)
1638 release_value (val);
1641 /* Release all values up to mark */
1643 value_release_to_mark (struct value *mark)
1648 for (val = next = all_values; next; next = next->next)
1650 if (next->next == mark)
1652 all_values = next->next;
1662 /* Return a copy of the value ARG.
1663 It contains the same contents, for same memory address,
1664 but it's a different block of storage. */
1667 value_copy (struct value *arg)
1669 struct type *encl_type = value_enclosing_type (arg);
1672 if (value_lazy (arg))
1673 val = allocate_value_lazy (encl_type);
1675 val = allocate_value (encl_type);
1676 val->type = arg->type;
1677 VALUE_LVAL (val) = VALUE_LVAL (arg);
1678 val->location = arg->location;
1679 val->offset = arg->offset;
1680 val->bitpos = arg->bitpos;
1681 val->bitsize = arg->bitsize;
1682 VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
1683 VALUE_REGNUM (val) = VALUE_REGNUM (arg);
1684 val->lazy = arg->lazy;
1685 val->embedded_offset = value_embedded_offset (arg);
1686 val->pointed_to_offset = arg->pointed_to_offset;
1687 val->modifiable = arg->modifiable;
1688 if (!value_lazy (val))
1690 memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
1691 TYPE_LENGTH (value_enclosing_type (arg)));
1694 val->unavailable = VEC_copy (range_s, arg->unavailable);
1695 val->optimized_out = VEC_copy (range_s, arg->optimized_out);
1696 set_value_parent (val, arg->parent);
1697 if (VALUE_LVAL (val) == lval_computed)
1699 const struct lval_funcs *funcs = val->location.computed.funcs;
1701 if (funcs->copy_closure)
1702 val->location.computed.closure = funcs->copy_closure (val);
1707 /* Return a "const" and/or "volatile" qualified version of the value V.
1708 If CNST is true, then the returned value will be qualified with
1710 if VOLTL is true, then the returned value will be qualified with
1714 make_cv_value (int cnst, int voltl, struct value *v)
1716 struct type *val_type = value_type (v);
1717 struct type *enclosing_type = value_enclosing_type (v);
1718 struct value *cv_val = value_copy (v);
1720 deprecated_set_value_type (cv_val,
1721 make_cv_type (cnst, voltl, val_type, NULL));
1722 set_value_enclosing_type (cv_val,
1723 make_cv_type (cnst, voltl, enclosing_type, NULL));
1728 /* Return a version of ARG that is non-lvalue. */
1731 value_non_lval (struct value *arg)
1733 if (VALUE_LVAL (arg) != not_lval)
1735 struct type *enc_type = value_enclosing_type (arg);
1736 struct value *val = allocate_value (enc_type);
1738 memcpy (value_contents_all_raw (val), value_contents_all (arg),
1739 TYPE_LENGTH (enc_type));
1740 val->type = arg->type;
1741 set_value_embedded_offset (val, value_embedded_offset (arg));
1742 set_value_pointed_to_offset (val, value_pointed_to_offset (arg));
1748 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1751 value_force_lval (struct value *v, CORE_ADDR addr)
1753 gdb_assert (VALUE_LVAL (v) == not_lval);
1755 write_memory (addr, value_contents_raw (v), TYPE_LENGTH (value_type (v)));
1756 v->lval = lval_memory;
1757 v->location.address = addr;
1761 set_value_component_location (struct value *component,
1762 const struct value *whole)
1764 gdb_assert (whole->lval != lval_xcallable);
1766 if (whole->lval == lval_internalvar)
1767 VALUE_LVAL (component) = lval_internalvar_component;
1769 VALUE_LVAL (component) = whole->lval;
1771 component->location = whole->location;
1772 if (whole->lval == lval_computed)
1774 const struct lval_funcs *funcs = whole->location.computed.funcs;
1776 if (funcs->copy_closure)
1777 component->location.computed.closure = funcs->copy_closure (whole);
1782 /* Access to the value history. */
1784 /* Record a new value in the value history.
1785 Returns the absolute history index of the entry. */
1788 record_latest_value (struct value *val)
1792 /* We don't want this value to have anything to do with the inferior anymore.
1793 In particular, "set $1 = 50" should not affect the variable from which
1794 the value was taken, and fast watchpoints should be able to assume that
1795 a value on the value history never changes. */
1796 if (value_lazy (val))
1797 value_fetch_lazy (val);
1798 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1799 from. This is a bit dubious, because then *&$1 does not just return $1
1800 but the current contents of that location. c'est la vie... */
1801 val->modifiable = 0;
1803 /* The value may have already been released, in which case we're adding a
1804 new reference for its entry in the history. That is why we call
1805 release_value_or_incref here instead of release_value. */
1806 release_value_or_incref (val);
1808 /* Here we treat value_history_count as origin-zero
1809 and applying to the value being stored now. */
1811 i = value_history_count % VALUE_HISTORY_CHUNK;
1814 struct value_history_chunk *newobj
1815 = (struct value_history_chunk *)
1817 xmalloc (sizeof (struct value_history_chunk));
1818 memset (newobj->values, 0, sizeof newobj->values);
1819 newobj->next = value_history_chain;
1820 value_history_chain = newobj;
1823 value_history_chain->values[i] = val;
1825 /* Now we regard value_history_count as origin-one
1826 and applying to the value just stored. */
1828 return ++value_history_count;
1831 /* Return a copy of the value in the history with sequence number NUM. */
1834 access_value_history (int num)
1836 struct value_history_chunk *chunk;
1841 absnum += value_history_count;
1846 error (_("The history is empty."));
1848 error (_("There is only one value in the history."));
1850 error (_("History does not go back to $$%d."), -num);
1852 if (absnum > value_history_count)
1853 error (_("History has not yet reached $%d."), absnum);
1857 /* Now absnum is always absolute and origin zero. */
1859 chunk = value_history_chain;
1860 for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK
1861 - absnum / VALUE_HISTORY_CHUNK;
1863 chunk = chunk->next;
1865 return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
1869 show_values (char *num_exp, int from_tty)
1877 /* "show values +" should print from the stored position.
1878 "show values <exp>" should print around value number <exp>. */
1879 if (num_exp[0] != '+' || num_exp[1] != '\0')
1880 num = parse_and_eval_long (num_exp) - 5;
1884 /* "show values" means print the last 10 values. */
1885 num = value_history_count - 9;
1891 for (i = num; i < num + 10 && i <= value_history_count; i++)
1893 struct value_print_options opts;
1895 val = access_value_history (i);
1896 printf_filtered (("$%d = "), i);
1897 get_user_print_options (&opts);
1898 value_print (val, gdb_stdout, &opts);
1899 printf_filtered (("\n"));
1902 /* The next "show values +" should start after what we just printed. */
1905 /* Hitting just return after this command should do the same thing as
1906 "show values +". If num_exp is null, this is unnecessary, since
1907 "show values +" is not useful after "show values". */
1908 if (from_tty && num_exp)
1915 enum internalvar_kind
1917 /* The internal variable is empty. */
1920 /* The value of the internal variable is provided directly as
1921 a GDB value object. */
1924 /* A fresh value is computed via a call-back routine on every
1925 access to the internal variable. */
1926 INTERNALVAR_MAKE_VALUE,
1928 /* The internal variable holds a GDB internal convenience function. */
1929 INTERNALVAR_FUNCTION,
1931 /* The variable holds an integer value. */
1932 INTERNALVAR_INTEGER,
1934 /* The variable holds a GDB-provided string. */
1938 union internalvar_data
1940 /* A value object used with INTERNALVAR_VALUE. */
1941 struct value *value;
1943 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1946 /* The functions to call. */
1947 const struct internalvar_funcs *functions;
1949 /* The function's user-data. */
1953 /* The internal function used with INTERNALVAR_FUNCTION. */
1956 struct internal_function *function;
1957 /* True if this is the canonical name for the function. */
1961 /* An integer value used with INTERNALVAR_INTEGER. */
1964 /* If type is non-NULL, it will be used as the type to generate
1965 a value for this internal variable. If type is NULL, a default
1966 integer type for the architecture is used. */
1971 /* A string value used with INTERNALVAR_STRING. */
1975 /* Internal variables. These are variables within the debugger
1976 that hold values assigned by debugger commands.
1977 The user refers to them with a '$' prefix
1978 that does not appear in the variable names stored internally. */
1982 struct internalvar *next;
1985 /* We support various different kinds of content of an internal variable.
1986 enum internalvar_kind specifies the kind, and union internalvar_data
1987 provides the data associated with this particular kind. */
1989 enum internalvar_kind kind;
1991 union internalvar_data u;
1994 static struct internalvar *internalvars;
1996 /* If the variable does not already exist create it and give it the
1997 value given. If no value is given then the default is zero. */
1999 init_if_undefined_command (char* args, int from_tty)
2001 struct internalvar* intvar;
2003 /* Parse the expression - this is taken from set_command(). */
2004 struct expression *expr = parse_expression (args);
2005 register struct cleanup *old_chain =
2006 make_cleanup (free_current_contents, &expr);
2008 /* Validate the expression.
2009 Was the expression an assignment?
2010 Or even an expression at all? */
2011 if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
2012 error (_("Init-if-undefined requires an assignment expression."));
2014 /* Extract the variable from the parsed expression.
2015 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2016 if (expr->elts[1].opcode != OP_INTERNALVAR)
2017 error (_("The first parameter to init-if-undefined "
2018 "should be a GDB variable."));
2019 intvar = expr->elts[2].internalvar;
2021 /* Only evaluate the expression if the lvalue is void.
2022 This may still fail if the expresssion is invalid. */
2023 if (intvar->kind == INTERNALVAR_VOID)
2024 evaluate_expression (expr);
2026 do_cleanups (old_chain);
2030 /* Look up an internal variable with name NAME. NAME should not
2031 normally include a dollar sign.
2033 If the specified internal variable does not exist,
2034 the return value is NULL. */
2036 struct internalvar *
2037 lookup_only_internalvar (const char *name)
2039 struct internalvar *var;
2041 for (var = internalvars; var; var = var->next)
2042 if (strcmp (var->name, name) == 0)
2048 /* Complete NAME by comparing it to the names of internal variables.
2049 Returns a vector of newly allocated strings, or NULL if no matches
2053 complete_internalvar (const char *name)
2055 VEC (char_ptr) *result = NULL;
2056 struct internalvar *var;
2059 len = strlen (name);
2061 for (var = internalvars; var; var = var->next)
2062 if (strncmp (var->name, name, len) == 0)
2064 char *r = xstrdup (var->name);
2066 VEC_safe_push (char_ptr, result, r);
2072 /* Create an internal variable with name NAME and with a void value.
2073 NAME should not normally include a dollar sign. */
2075 struct internalvar *
2076 create_internalvar (const char *name)
2078 struct internalvar *var;
2080 var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
2081 var->name = concat (name, (char *)NULL);
2082 var->kind = INTERNALVAR_VOID;
2083 var->next = internalvars;
2088 /* Create an internal variable with name NAME and register FUN as the
2089 function that value_of_internalvar uses to create a value whenever
2090 this variable is referenced. NAME should not normally include a
2091 dollar sign. DATA is passed uninterpreted to FUN when it is
2092 called. CLEANUP, if not NULL, is called when the internal variable
2093 is destroyed. It is passed DATA as its only argument. */
2095 struct internalvar *
2096 create_internalvar_type_lazy (const char *name,
2097 const struct internalvar_funcs *funcs,
2100 struct internalvar *var = create_internalvar (name);
2102 var->kind = INTERNALVAR_MAKE_VALUE;
2103 var->u.make_value.functions = funcs;
2104 var->u.make_value.data = data;
2108 /* See documentation in value.h. */
2111 compile_internalvar_to_ax (struct internalvar *var,
2112 struct agent_expr *expr,
2113 struct axs_value *value)
2115 if (var->kind != INTERNALVAR_MAKE_VALUE
2116 || var->u.make_value.functions->compile_to_ax == NULL)
2119 var->u.make_value.functions->compile_to_ax (var, expr, value,
2120 var->u.make_value.data);
2124 /* Look up an internal variable with name NAME. NAME should not
2125 normally include a dollar sign.
2127 If the specified internal variable does not exist,
2128 one is created, with a void value. */
2130 struct internalvar *
2131 lookup_internalvar (const char *name)
2133 struct internalvar *var;
2135 var = lookup_only_internalvar (name);
2139 return create_internalvar (name);
2142 /* Return current value of internal variable VAR. For variables that
2143 are not inherently typed, use a value type appropriate for GDBARCH. */
2146 value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
2149 struct trace_state_variable *tsv;
2151 /* If there is a trace state variable of the same name, assume that
2152 is what we really want to see. */
2153 tsv = find_trace_state_variable (var->name);
2156 tsv->value_known = target_get_trace_state_variable_value (tsv->number,
2158 if (tsv->value_known)
2159 val = value_from_longest (builtin_type (gdbarch)->builtin_int64,
2162 val = allocate_value (builtin_type (gdbarch)->builtin_void);
2168 case INTERNALVAR_VOID:
2169 val = allocate_value (builtin_type (gdbarch)->builtin_void);
2172 case INTERNALVAR_FUNCTION:
2173 val = allocate_value (builtin_type (gdbarch)->internal_fn);
2176 case INTERNALVAR_INTEGER:
2177 if (!var->u.integer.type)
2178 val = value_from_longest (builtin_type (gdbarch)->builtin_int,
2179 var->u.integer.val);
2181 val = value_from_longest (var->u.integer.type, var->u.integer.val);
2184 case INTERNALVAR_STRING:
2185 val = value_cstring (var->u.string, strlen (var->u.string),
2186 builtin_type (gdbarch)->builtin_char);
2189 case INTERNALVAR_VALUE:
2190 val = value_copy (var->u.value);
2191 if (value_lazy (val))
2192 value_fetch_lazy (val);
2195 case INTERNALVAR_MAKE_VALUE:
2196 val = (*var->u.make_value.functions->make_value) (gdbarch, var,
2197 var->u.make_value.data);
2201 internal_error (__FILE__, __LINE__, _("bad kind"));
2204 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2205 on this value go back to affect the original internal variable.
2207 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2208 no underlying modifyable state in the internal variable.
2210 Likewise, if the variable's value is a computed lvalue, we want
2211 references to it to produce another computed lvalue, where
2212 references and assignments actually operate through the
2213 computed value's functions.
2215 This means that internal variables with computed values
2216 behave a little differently from other internal variables:
2217 assignments to them don't just replace the previous value
2218 altogether. At the moment, this seems like the behavior we
2221 if (var->kind != INTERNALVAR_MAKE_VALUE
2222 && val->lval != lval_computed)
2224 VALUE_LVAL (val) = lval_internalvar;
2225 VALUE_INTERNALVAR (val) = var;
2232 get_internalvar_integer (struct internalvar *var, LONGEST *result)
2234 if (var->kind == INTERNALVAR_INTEGER)
2236 *result = var->u.integer.val;
2240 if (var->kind == INTERNALVAR_VALUE)
2242 struct type *type = check_typedef (value_type (var->u.value));
2244 if (TYPE_CODE (type) == TYPE_CODE_INT)
2246 *result = value_as_long (var->u.value);
2255 get_internalvar_function (struct internalvar *var,
2256 struct internal_function **result)
2260 case INTERNALVAR_FUNCTION:
2261 *result = var->u.fn.function;
2270 set_internalvar_component (struct internalvar *var, int offset, int bitpos,
2271 int bitsize, struct value *newval)
2277 case INTERNALVAR_VALUE:
2278 addr = value_contents_writeable (var->u.value);
2281 modify_field (value_type (var->u.value), addr + offset,
2282 value_as_long (newval), bitpos, bitsize);
2284 memcpy (addr + offset, value_contents (newval),
2285 TYPE_LENGTH (value_type (newval)));
2289 /* We can never get a component of any other kind. */
2290 internal_error (__FILE__, __LINE__, _("set_internalvar_component"));
2295 set_internalvar (struct internalvar *var, struct value *val)
2297 enum internalvar_kind new_kind;
2298 union internalvar_data new_data = { 0 };
2300 if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
2301 error (_("Cannot overwrite convenience function %s"), var->name);
2303 /* Prepare new contents. */
2304 switch (TYPE_CODE (check_typedef (value_type (val))))
2306 case TYPE_CODE_VOID:
2307 new_kind = INTERNALVAR_VOID;
2310 case TYPE_CODE_INTERNAL_FUNCTION:
2311 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
2312 new_kind = INTERNALVAR_FUNCTION;
2313 get_internalvar_function (VALUE_INTERNALVAR (val),
2314 &new_data.fn.function);
2315 /* Copies created here are never canonical. */
2319 new_kind = INTERNALVAR_VALUE;
2320 new_data.value = value_copy (val);
2321 new_data.value->modifiable = 1;
2323 /* Force the value to be fetched from the target now, to avoid problems
2324 later when this internalvar is referenced and the target is gone or
2326 if (value_lazy (new_data.value))
2327 value_fetch_lazy (new_data.value);
2329 /* Release the value from the value chain to prevent it from being
2330 deleted by free_all_values. From here on this function should not
2331 call error () until new_data is installed into the var->u to avoid
2333 release_value (new_data.value);
2337 /* Clean up old contents. */
2338 clear_internalvar (var);
2341 var->kind = new_kind;
2343 /* End code which must not call error(). */
2347 set_internalvar_integer (struct internalvar *var, LONGEST l)
2349 /* Clean up old contents. */
2350 clear_internalvar (var);
2352 var->kind = INTERNALVAR_INTEGER;
2353 var->u.integer.type = NULL;
2354 var->u.integer.val = l;
2358 set_internalvar_string (struct internalvar *var, const char *string)
2360 /* Clean up old contents. */
2361 clear_internalvar (var);
2363 var->kind = INTERNALVAR_STRING;
2364 var->u.string = xstrdup (string);
2368 set_internalvar_function (struct internalvar *var, struct internal_function *f)
2370 /* Clean up old contents. */
2371 clear_internalvar (var);
2373 var->kind = INTERNALVAR_FUNCTION;
2374 var->u.fn.function = f;
2375 var->u.fn.canonical = 1;
2376 /* Variables installed here are always the canonical version. */
2380 clear_internalvar (struct internalvar *var)
2382 /* Clean up old contents. */
2385 case INTERNALVAR_VALUE:
2386 value_free (var->u.value);
2389 case INTERNALVAR_STRING:
2390 xfree (var->u.string);
2393 case INTERNALVAR_MAKE_VALUE:
2394 if (var->u.make_value.functions->destroy != NULL)
2395 var->u.make_value.functions->destroy (var->u.make_value.data);
2402 /* Reset to void kind. */
2403 var->kind = INTERNALVAR_VOID;
2407 internalvar_name (struct internalvar *var)
2412 static struct internal_function *
2413 create_internal_function (const char *name,
2414 internal_function_fn handler, void *cookie)
2416 struct internal_function *ifn = XNEW (struct internal_function);
2418 ifn->name = xstrdup (name);
2419 ifn->handler = handler;
2420 ifn->cookie = cookie;
2425 value_internal_function_name (struct value *val)
2427 struct internal_function *ifn;
2430 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
2431 result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
2432 gdb_assert (result);
2438 call_internal_function (struct gdbarch *gdbarch,
2439 const struct language_defn *language,
2440 struct value *func, int argc, struct value **argv)
2442 struct internal_function *ifn;
2445 gdb_assert (VALUE_LVAL (func) == lval_internalvar);
2446 result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
2447 gdb_assert (result);
2449 return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
2452 /* The 'function' command. This does nothing -- it is just a
2453 placeholder to let "help function NAME" work. This is also used as
2454 the implementation of the sub-command that is created when
2455 registering an internal function. */
2457 function_command (char *command, int from_tty)
2462 /* Clean up if an internal function's command is destroyed. */
2464 function_destroyer (struct cmd_list_element *self, void *ignore)
2466 xfree ((char *) self->name);
2467 xfree ((char *) self->doc);
2470 /* Add a new internal function. NAME is the name of the function; DOC
2471 is a documentation string describing the function. HANDLER is
2472 called when the function is invoked. COOKIE is an arbitrary
2473 pointer which is passed to HANDLER and is intended for "user
2476 add_internal_function (const char *name, const char *doc,
2477 internal_function_fn handler, void *cookie)
2479 struct cmd_list_element *cmd;
2480 struct internal_function *ifn;
2481 struct internalvar *var = lookup_internalvar (name);
2483 ifn = create_internal_function (name, handler, cookie);
2484 set_internalvar_function (var, ifn);
2486 cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
2488 cmd->destroyer = function_destroyer;
2491 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2492 prevent cycles / duplicates. */
2495 preserve_one_value (struct value *value, struct objfile *objfile,
2496 htab_t copied_types)
2498 if (TYPE_OBJFILE (value->type) == objfile)
2499 value->type = copy_type_recursive (objfile, value->type, copied_types);
2501 if (TYPE_OBJFILE (value->enclosing_type) == objfile)
2502 value->enclosing_type = copy_type_recursive (objfile,
2503 value->enclosing_type,
2507 /* Likewise for internal variable VAR. */
2510 preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
2511 htab_t copied_types)
2515 case INTERNALVAR_INTEGER:
2516 if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
2518 = copy_type_recursive (objfile, var->u.integer.type, copied_types);
2521 case INTERNALVAR_VALUE:
2522 preserve_one_value (var->u.value, objfile, copied_types);
2527 /* Update the internal variables and value history when OBJFILE is
2528 discarded; we must copy the types out of the objfile. New global types
2529 will be created for every convenience variable which currently points to
2530 this objfile's types, and the convenience variables will be adjusted to
2531 use the new global types. */
2534 preserve_values (struct objfile *objfile)
2536 htab_t copied_types;
2537 struct value_history_chunk *cur;
2538 struct internalvar *var;
2541 /* Create the hash table. We allocate on the objfile's obstack, since
2542 it is soon to be deleted. */
2543 copied_types = create_copied_types_hash (objfile);
2545 for (cur = value_history_chain; cur; cur = cur->next)
2546 for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
2548 preserve_one_value (cur->values[i], objfile, copied_types);
2550 for (var = internalvars; var; var = var->next)
2551 preserve_one_internalvar (var, objfile, copied_types);
2553 preserve_ext_lang_values (objfile, copied_types);
2555 htab_delete (copied_types);
2559 show_convenience (char *ignore, int from_tty)
2561 struct gdbarch *gdbarch = get_current_arch ();
2562 struct internalvar *var;
2564 struct value_print_options opts;
2566 get_user_print_options (&opts);
2567 for (var = internalvars; var; var = var->next)
2574 printf_filtered (("$%s = "), var->name);
2580 val = value_of_internalvar (gdbarch, var);
2581 value_print (val, gdb_stdout, &opts);
2583 CATCH (ex, RETURN_MASK_ERROR)
2585 fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
2589 printf_filtered (("\n"));
2593 /* This text does not mention convenience functions on purpose.
2594 The user can't create them except via Python, and if Python support
2595 is installed this message will never be printed ($_streq will
2597 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2598 "Convenience variables have "
2599 "names starting with \"$\";\n"
2600 "use \"set\" as in \"set "
2601 "$foo = 5\" to define them.\n"));
2605 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2608 value_of_xmethod (struct xmethod_worker *worker)
2610 if (worker->value == NULL)
2614 v = allocate_value (builtin_type (target_gdbarch ())->xmethod);
2615 v->lval = lval_xcallable;
2616 v->location.xm_worker = worker;
2621 return worker->value;
2624 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2627 result_type_of_xmethod (struct value *method, int argc, struct value **argv)
2629 gdb_assert (TYPE_CODE (value_type (method)) == TYPE_CODE_XMETHOD
2630 && method->lval == lval_xcallable && argc > 0);
2632 return get_xmethod_result_type (method->location.xm_worker,
2633 argv[0], argv + 1, argc - 1);
2636 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2639 call_xmethod (struct value *method, int argc, struct value **argv)
2641 gdb_assert (TYPE_CODE (value_type (method)) == TYPE_CODE_XMETHOD
2642 && method->lval == lval_xcallable && argc > 0);
2644 return invoke_xmethod (method->location.xm_worker,
2645 argv[0], argv + 1, argc - 1);
2648 /* Extract a value as a C number (either long or double).
2649 Knows how to convert fixed values to double, or
2650 floating values to long.
2651 Does not deallocate the value. */
2654 value_as_long (struct value *val)
2656 /* This coerces arrays and functions, which is necessary (e.g.
2657 in disassemble_command). It also dereferences references, which
2658 I suspect is the most logical thing to do. */
2659 val = coerce_array (val);
2660 return unpack_long (value_type (val), value_contents (val));
2664 value_as_double (struct value *val)
2669 foo = unpack_double (value_type (val), value_contents (val), &inv);
2671 error (_("Invalid floating value found in program."));
2675 /* Extract a value as a C pointer. Does not deallocate the value.
2676 Note that val's type may not actually be a pointer; value_as_long
2677 handles all the cases. */
2679 value_as_address (struct value *val)
2681 struct gdbarch *gdbarch = get_type_arch (value_type (val));
2683 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2684 whether we want this to be true eventually. */
2686 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2687 non-address (e.g. argument to "signal", "info break", etc.), or
2688 for pointers to char, in which the low bits *are* significant. */
2689 return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
2692 /* There are several targets (IA-64, PowerPC, and others) which
2693 don't represent pointers to functions as simply the address of
2694 the function's entry point. For example, on the IA-64, a
2695 function pointer points to a two-word descriptor, generated by
2696 the linker, which contains the function's entry point, and the
2697 value the IA-64 "global pointer" register should have --- to
2698 support position-independent code. The linker generates
2699 descriptors only for those functions whose addresses are taken.
2701 On such targets, it's difficult for GDB to convert an arbitrary
2702 function address into a function pointer; it has to either find
2703 an existing descriptor for that function, or call malloc and
2704 build its own. On some targets, it is impossible for GDB to
2705 build a descriptor at all: the descriptor must contain a jump
2706 instruction; data memory cannot be executed; and code memory
2709 Upon entry to this function, if VAL is a value of type `function'
2710 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2711 value_address (val) is the address of the function. This is what
2712 you'll get if you evaluate an expression like `main'. The call
2713 to COERCE_ARRAY below actually does all the usual unary
2714 conversions, which includes converting values of type `function'
2715 to `pointer to function'. This is the challenging conversion
2716 discussed above. Then, `unpack_long' will convert that pointer
2717 back into an address.
2719 So, suppose the user types `disassemble foo' on an architecture
2720 with a strange function pointer representation, on which GDB
2721 cannot build its own descriptors, and suppose further that `foo'
2722 has no linker-built descriptor. The address->pointer conversion
2723 will signal an error and prevent the command from running, even
2724 though the next step would have been to convert the pointer
2725 directly back into the same address.
2727 The following shortcut avoids this whole mess. If VAL is a
2728 function, just return its address directly. */
2729 if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
2730 || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
2731 return value_address (val);
2733 val = coerce_array (val);
2735 /* Some architectures (e.g. Harvard), map instruction and data
2736 addresses onto a single large unified address space. For
2737 instance: An architecture may consider a large integer in the
2738 range 0x10000000 .. 0x1000ffff to already represent a data
2739 addresses (hence not need a pointer to address conversion) while
2740 a small integer would still need to be converted integer to
2741 pointer to address. Just assume such architectures handle all
2742 integer conversions in a single function. */
2746 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2747 must admonish GDB hackers to make sure its behavior matches the
2748 compiler's, whenever possible.
2750 In general, I think GDB should evaluate expressions the same way
2751 the compiler does. When the user copies an expression out of
2752 their source code and hands it to a `print' command, they should
2753 get the same value the compiler would have computed. Any
2754 deviation from this rule can cause major confusion and annoyance,
2755 and needs to be justified carefully. In other words, GDB doesn't
2756 really have the freedom to do these conversions in clever and
2759 AndrewC pointed out that users aren't complaining about how GDB
2760 casts integers to pointers; they are complaining that they can't
2761 take an address from a disassembly listing and give it to `x/i'.
2762 This is certainly important.
2764 Adding an architecture method like integer_to_address() certainly
2765 makes it possible for GDB to "get it right" in all circumstances
2766 --- the target has complete control over how things get done, so
2767 people can Do The Right Thing for their target without breaking
2768 anyone else. The standard doesn't specify how integers get
2769 converted to pointers; usually, the ABI doesn't either, but
2770 ABI-specific code is a more reasonable place to handle it. */
2772 if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
2773 && TYPE_CODE (value_type (val)) != TYPE_CODE_REF
2774 && gdbarch_integer_to_address_p (gdbarch))
2775 return gdbarch_integer_to_address (gdbarch, value_type (val),
2776 value_contents (val));
2778 return unpack_long (value_type (val), value_contents (val));
2782 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2783 as a long, or as a double, assuming the raw data is described
2784 by type TYPE. Knows how to convert different sizes of values
2785 and can convert between fixed and floating point. We don't assume
2786 any alignment for the raw data. Return value is in host byte order.
2788 If you want functions and arrays to be coerced to pointers, and
2789 references to be dereferenced, call value_as_long() instead.
2791 C++: It is assumed that the front-end has taken care of
2792 all matters concerning pointers to members. A pointer
2793 to member which reaches here is considered to be equivalent
2794 to an INT (or some size). After all, it is only an offset. */
2797 unpack_long (struct type *type, const gdb_byte *valaddr)
2799 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2800 enum type_code code = TYPE_CODE (type);
2801 int len = TYPE_LENGTH (type);
2802 int nosign = TYPE_UNSIGNED (type);
2806 case TYPE_CODE_TYPEDEF:
2807 return unpack_long (check_typedef (type), valaddr);
2808 case TYPE_CODE_ENUM:
2809 case TYPE_CODE_FLAGS:
2810 case TYPE_CODE_BOOL:
2812 case TYPE_CODE_CHAR:
2813 case TYPE_CODE_RANGE:
2814 case TYPE_CODE_MEMBERPTR:
2816 return extract_unsigned_integer (valaddr, len, byte_order);
2818 return extract_signed_integer (valaddr, len, byte_order);
2821 return extract_typed_floating (valaddr, type);
2823 case TYPE_CODE_DECFLOAT:
2824 /* libdecnumber has a function to convert from decimal to integer, but
2825 it doesn't work when the decimal number has a fractional part. */
2826 return decimal_to_doublest (valaddr, len, byte_order);
2830 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2831 whether we want this to be true eventually. */
2832 return extract_typed_address (valaddr, type);
2835 error (_("Value can't be converted to integer."));
2837 return 0; /* Placate lint. */
2840 /* Return a double value from the specified type and address.
2841 INVP points to an int which is set to 0 for valid value,
2842 1 for invalid value (bad float format). In either case,
2843 the returned double is OK to use. Argument is in target
2844 format, result is in host format. */
2847 unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
2849 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2850 enum type_code code;
2854 *invp = 0; /* Assume valid. */
2855 type = check_typedef (type);
2856 code = TYPE_CODE (type);
2857 len = TYPE_LENGTH (type);
2858 nosign = TYPE_UNSIGNED (type);
2859 if (code == TYPE_CODE_FLT)
2861 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2862 floating-point value was valid (using the macro
2863 INVALID_FLOAT). That test/macro have been removed.
2865 It turns out that only the VAX defined this macro and then
2866 only in a non-portable way. Fixing the portability problem
2867 wouldn't help since the VAX floating-point code is also badly
2868 bit-rotten. The target needs to add definitions for the
2869 methods gdbarch_float_format and gdbarch_double_format - these
2870 exactly describe the target floating-point format. The
2871 problem here is that the corresponding floatformat_vax_f and
2872 floatformat_vax_d values these methods should be set to are
2873 also not defined either. Oops!
2875 Hopefully someone will add both the missing floatformat
2876 definitions and the new cases for floatformat_is_valid (). */
2878 if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
2884 return extract_typed_floating (valaddr, type);
2886 else if (code == TYPE_CODE_DECFLOAT)
2887 return decimal_to_doublest (valaddr, len, byte_order);
2890 /* Unsigned -- be sure we compensate for signed LONGEST. */
2891 return (ULONGEST) unpack_long (type, valaddr);
2895 /* Signed -- we are OK with unpack_long. */
2896 return unpack_long (type, valaddr);
2900 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2901 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2902 We don't assume any alignment for the raw data. Return value is in
2905 If you want functions and arrays to be coerced to pointers, and
2906 references to be dereferenced, call value_as_address() instead.
2908 C++: It is assumed that the front-end has taken care of
2909 all matters concerning pointers to members. A pointer
2910 to member which reaches here is considered to be equivalent
2911 to an INT (or some size). After all, it is only an offset. */
2914 unpack_pointer (struct type *type, const gdb_byte *valaddr)
2916 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2917 whether we want this to be true eventually. */
2918 return unpack_long (type, valaddr);
2922 /* Get the value of the FIELDNO'th field (which must be static) of
2926 value_static_field (struct type *type, int fieldno)
2928 struct value *retval;
2930 switch (TYPE_FIELD_LOC_KIND (type, fieldno))
2932 case FIELD_LOC_KIND_PHYSADDR:
2933 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2934 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
2936 case FIELD_LOC_KIND_PHYSNAME:
2938 const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
2939 /* TYPE_FIELD_NAME (type, fieldno); */
2940 struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
2944 /* With some compilers, e.g. HP aCC, static data members are
2945 reported as non-debuggable symbols. */
2946 struct bound_minimal_symbol msym
2947 = lookup_minimal_symbol (phys_name, NULL, NULL);
2950 return allocate_optimized_out_value (type);
2953 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
2954 BMSYMBOL_VALUE_ADDRESS (msym));
2958 retval = value_of_variable (sym, NULL);
2962 gdb_assert_not_reached ("unexpected field location kind");
2968 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2969 You have to be careful here, since the size of the data area for the value
2970 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2971 than the old enclosing type, you have to allocate more space for the
2975 set_value_enclosing_type (struct value *val, struct type *new_encl_type)
2977 if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
2979 (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
2981 val->enclosing_type = new_encl_type;
2984 /* Given a value ARG1 (offset by OFFSET bytes)
2985 of a struct or union type ARG_TYPE,
2986 extract and return the value of one of its (non-static) fields.
2987 FIELDNO says which field. */
2990 value_primitive_field (struct value *arg1, int offset,
2991 int fieldno, struct type *arg_type)
2996 arg_type = check_typedef (arg_type);
2997 type = TYPE_FIELD_TYPE (arg_type, fieldno);
2999 /* Call check_typedef on our type to make sure that, if TYPE
3000 is a TYPE_CODE_TYPEDEF, its length is set to the length
3001 of the target type instead of zero. However, we do not
3002 replace the typedef type by the target type, because we want
3003 to keep the typedef in order to be able to print the type
3004 description correctly. */
3005 check_typedef (type);
3007 if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
3009 /* Handle packed fields.
3011 Create a new value for the bitfield, with bitpos and bitsize
3012 set. If possible, arrange offset and bitpos so that we can
3013 do a single aligned read of the size of the containing type.
3014 Otherwise, adjust offset to the byte containing the first
3015 bit. Assume that the address, offset, and embedded offset
3016 are sufficiently aligned. */
3018 int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
3019 int container_bitsize = TYPE_LENGTH (type) * 8;
3021 v = allocate_value_lazy (type);
3022 v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
3023 if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
3024 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
3025 v->bitpos = bitpos % container_bitsize;
3027 v->bitpos = bitpos % 8;
3028 v->offset = (value_embedded_offset (arg1)
3030 + (bitpos - v->bitpos) / 8);
3031 set_value_parent (v, arg1);
3032 if (!value_lazy (arg1))
3033 value_fetch_lazy (v);
3035 else if (fieldno < TYPE_N_BASECLASSES (arg_type))
3037 /* This field is actually a base subobject, so preserve the
3038 entire object's contents for later references to virtual
3042 /* Lazy register values with offsets are not supported. */
3043 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
3044 value_fetch_lazy (arg1);
3046 /* We special case virtual inheritance here because this
3047 requires access to the contents, which we would rather avoid
3048 for references to ordinary fields of unavailable values. */
3049 if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno))
3050 boffset = baseclass_offset (arg_type, fieldno,
3051 value_contents (arg1),
3052 value_embedded_offset (arg1),
3053 value_address (arg1),
3056 boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
3058 if (value_lazy (arg1))
3059 v = allocate_value_lazy (value_enclosing_type (arg1));
3062 v = allocate_value (value_enclosing_type (arg1));
3063 value_contents_copy_raw (v, 0, arg1, 0,
3064 TYPE_LENGTH (value_enclosing_type (arg1)));
3067 v->offset = value_offset (arg1);
3068 v->embedded_offset = offset + value_embedded_offset (arg1) + boffset;
3072 /* Plain old data member */
3073 offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
3075 /* Lazy register values with offsets are not supported. */
3076 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
3077 value_fetch_lazy (arg1);
3079 if (value_lazy (arg1))
3080 v = allocate_value_lazy (type);
3083 v = allocate_value (type);
3084 value_contents_copy_raw (v, value_embedded_offset (v),
3085 arg1, value_embedded_offset (arg1) + offset,
3086 TYPE_LENGTH (type));
3088 v->offset = (value_offset (arg1) + offset
3089 + value_embedded_offset (arg1));
3091 set_value_component_location (v, arg1);
3092 VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
3093 VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
3097 /* Given a value ARG1 of a struct or union type,
3098 extract and return the value of one of its (non-static) fields.
3099 FIELDNO says which field. */
3102 value_field (struct value *arg1, int fieldno)
3104 return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
3107 /* Return a non-virtual function as a value.
3108 F is the list of member functions which contains the desired method.
3109 J is an index into F which provides the desired method.
3111 We only use the symbol for its address, so be happy with either a
3112 full symbol or a minimal symbol. */
3115 value_fn_field (struct value **arg1p, struct fn_field *f,
3116 int j, struct type *type,
3120 struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
3121 const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
3123 struct bound_minimal_symbol msym;
3125 sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
3128 memset (&msym, 0, sizeof (msym));
3132 gdb_assert (sym == NULL);
3133 msym = lookup_bound_minimal_symbol (physname);
3134 if (msym.minsym == NULL)
3138 v = allocate_value (ftype);
3141 set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
3145 /* The minimal symbol might point to a function descriptor;
3146 resolve it to the actual code address instead. */
3147 struct objfile *objfile = msym.objfile;
3148 struct gdbarch *gdbarch = get_objfile_arch (objfile);
3150 set_value_address (v,
3151 gdbarch_convert_from_func_ptr_addr
3152 (gdbarch, BMSYMBOL_VALUE_ADDRESS (msym), ¤t_target));
3157 if (type != value_type (*arg1p))
3158 *arg1p = value_ind (value_cast (lookup_pointer_type (type),
3159 value_addr (*arg1p)));
3161 /* Move the `this' pointer according to the offset.
3162 VALUE_OFFSET (*arg1p) += offset; */
3170 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3171 VALADDR, and store the result in *RESULT.
3172 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3174 Extracting bits depends on endianness of the machine. Compute the
3175 number of least significant bits to discard. For big endian machines,
3176 we compute the total number of bits in the anonymous object, subtract
3177 off the bit count from the MSB of the object to the MSB of the
3178 bitfield, then the size of the bitfield, which leaves the LSB discard
3179 count. For little endian machines, the discard count is simply the
3180 number of bits from the LSB of the anonymous object to the LSB of the
3183 If the field is signed, we also do sign extension. */
3186 unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
3187 int bitpos, int bitsize)
3189 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
3196 /* Read the minimum number of bytes required; there may not be
3197 enough bytes to read an entire ULONGEST. */
3198 field_type = check_typedef (field_type);
3200 bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
3202 bytes_read = TYPE_LENGTH (field_type);
3204 read_offset = bitpos / 8;
3206 val = extract_unsigned_integer (valaddr + read_offset,
3207 bytes_read, byte_order);
3209 /* Extract bits. See comment above. */
3211 if (gdbarch_bits_big_endian (get_type_arch (field_type)))
3212 lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
3214 lsbcount = (bitpos % 8);
3217 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3218 If the field is signed, and is negative, then sign extend. */
3220 if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
3222 valmask = (((ULONGEST) 1) << bitsize) - 1;
3224 if (!TYPE_UNSIGNED (field_type))
3226 if (val & (valmask ^ (valmask >> 1)))
3236 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3237 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3238 ORIGINAL_VALUE, which must not be NULL. See
3239 unpack_value_bits_as_long for more details. */
3242 unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
3243 int embedded_offset, int fieldno,
3244 const struct value *val, LONGEST *result)
3246 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3247 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3248 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
3251 gdb_assert (val != NULL);
3253 bit_offset = embedded_offset * TARGET_CHAR_BIT + bitpos;
3254 if (value_bits_any_optimized_out (val, bit_offset, bitsize)
3255 || !value_bits_available (val, bit_offset, bitsize))
3258 *result = unpack_bits_as_long (field_type, valaddr + embedded_offset,
3263 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3264 object at VALADDR. See unpack_bits_as_long for more details. */
3267 unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
3269 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3270 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3271 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
3273 return unpack_bits_as_long (field_type, valaddr, bitpos, bitsize);
3276 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3277 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3278 the contents in DEST_VAL, zero or sign extending if the type of
3279 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3280 VAL. If the VAL's contents required to extract the bitfield from
3281 are unavailable/optimized out, DEST_VAL is correspondingly
3282 marked unavailable/optimized out. */
3285 unpack_value_bitfield (struct value *dest_val,
3286 int bitpos, int bitsize,
3287 const gdb_byte *valaddr, int embedded_offset,
3288 const struct value *val)
3290 enum bfd_endian byte_order;
3294 struct type *field_type = value_type (dest_val);
3296 /* First, unpack and sign extend the bitfield as if it was wholly
3297 available. Invalid/unavailable bits are read as zero, but that's
3298 OK, as they'll end up marked below. */
3299 byte_order = gdbarch_byte_order (get_type_arch (field_type));
3300 num = unpack_bits_as_long (field_type, valaddr + embedded_offset,
3302 store_signed_integer (value_contents_raw (dest_val),
3303 TYPE_LENGTH (field_type), byte_order, num);
3305 /* Now copy the optimized out / unavailability ranges to the right
3307 src_bit_offset = embedded_offset * TARGET_CHAR_BIT + bitpos;
3308 if (byte_order == BFD_ENDIAN_BIG)
3309 dst_bit_offset = TYPE_LENGTH (field_type) * TARGET_CHAR_BIT - bitsize;
3312 value_ranges_copy_adjusted (dest_val, dst_bit_offset,
3313 val, src_bit_offset, bitsize);
3316 /* Return a new value with type TYPE, which is FIELDNO field of the
3317 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3318 of VAL. If the VAL's contents required to extract the bitfield
3319 from are unavailable/optimized out, the new value is
3320 correspondingly marked unavailable/optimized out. */
3323 value_field_bitfield (struct type *type, int fieldno,
3324 const gdb_byte *valaddr,
3325 int embedded_offset, const struct value *val)
3327 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3328 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3329 struct value *res_val = allocate_value (TYPE_FIELD_TYPE (type, fieldno));
3331 unpack_value_bitfield (res_val, bitpos, bitsize,
3332 valaddr, embedded_offset, val);
3337 /* Modify the value of a bitfield. ADDR points to a block of memory in
3338 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3339 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3340 indicate which bits (in target bit order) comprise the bitfield.
3341 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3342 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3345 modify_field (struct type *type, gdb_byte *addr,
3346 LONGEST fieldval, int bitpos, int bitsize)
3348 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
3350 ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
3353 /* Normalize BITPOS. */
3357 /* If a negative fieldval fits in the field in question, chop
3358 off the sign extension bits. */
3359 if ((~fieldval & ~(mask >> 1)) == 0)
3362 /* Warn if value is too big to fit in the field in question. */
3363 if (0 != (fieldval & ~mask))
3365 /* FIXME: would like to include fieldval in the message, but
3366 we don't have a sprintf_longest. */
3367 warning (_("Value does not fit in %d bits."), bitsize);
3369 /* Truncate it, otherwise adjoining fields may be corrupted. */
3373 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3374 false valgrind reports. */
3376 bytesize = (bitpos + bitsize + 7) / 8;
3377 oword = extract_unsigned_integer (addr, bytesize, byte_order);
3379 /* Shifting for bit field depends on endianness of the target machine. */
3380 if (gdbarch_bits_big_endian (get_type_arch (type)))
3381 bitpos = bytesize * 8 - bitpos - bitsize;
3383 oword &= ~(mask << bitpos);
3384 oword |= fieldval << bitpos;
3386 store_unsigned_integer (addr, bytesize, byte_order, oword);
3389 /* Pack NUM into BUF using a target format of TYPE. */
3392 pack_long (gdb_byte *buf, struct type *type, LONGEST num)
3394 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
3397 type = check_typedef (type);
3398 len = TYPE_LENGTH (type);
3400 switch (TYPE_CODE (type))
3403 case TYPE_CODE_CHAR:
3404 case TYPE_CODE_ENUM:
3405 case TYPE_CODE_FLAGS:
3406 case TYPE_CODE_BOOL:
3407 case TYPE_CODE_RANGE:
3408 case TYPE_CODE_MEMBERPTR:
3409 store_signed_integer (buf, len, byte_order, num);
3414 store_typed_address (buf, type, (CORE_ADDR) num);
3418 error (_("Unexpected type (%d) encountered for integer constant."),
3424 /* Pack NUM into BUF using a target format of TYPE. */
3427 pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
3430 enum bfd_endian byte_order;
3432 type = check_typedef (type);
3433 len = TYPE_LENGTH (type);
3434 byte_order = gdbarch_byte_order (get_type_arch (type));
3436 switch (TYPE_CODE (type))
3439 case TYPE_CODE_CHAR:
3440 case TYPE_CODE_ENUM:
3441 case TYPE_CODE_FLAGS:
3442 case TYPE_CODE_BOOL:
3443 case TYPE_CODE_RANGE:
3444 case TYPE_CODE_MEMBERPTR:
3445 store_unsigned_integer (buf, len, byte_order, num);
3450 store_typed_address (buf, type, (CORE_ADDR) num);
3454 error (_("Unexpected type (%d) encountered "
3455 "for unsigned integer constant."),
3461 /* Convert C numbers into newly allocated values. */
3464 value_from_longest (struct type *type, LONGEST num)
3466 struct value *val = allocate_value (type);
3468 pack_long (value_contents_raw (val), type, num);
3473 /* Convert C unsigned numbers into newly allocated values. */
3476 value_from_ulongest (struct type *type, ULONGEST num)
3478 struct value *val = allocate_value (type);
3480 pack_unsigned_long (value_contents_raw (val), type, num);
3486 /* Create a value representing a pointer of type TYPE to the address
3490 value_from_pointer (struct type *type, CORE_ADDR addr)
3492 struct value *val = allocate_value (type);
3494 store_typed_address (value_contents_raw (val),
3495 check_typedef (type), addr);
3500 /* Create a value of type TYPE whose contents come from VALADDR, if it
3501 is non-null, and whose memory address (in the inferior) is
3502 ADDRESS. The type of the created value may differ from the passed
3503 type TYPE. Make sure to retrieve values new type after this call.
3504 Note that TYPE is not passed through resolve_dynamic_type; this is
3505 a special API intended for use only by Ada. */
3508 value_from_contents_and_address_unresolved (struct type *type,
3509 const gdb_byte *valaddr,
3514 if (valaddr == NULL)
3515 v = allocate_value_lazy (type);
3517 v = value_from_contents (type, valaddr);
3518 set_value_address (v, address);
3519 VALUE_LVAL (v) = lval_memory;
3523 /* Create a value of type TYPE whose contents come from VALADDR, if it
3524 is non-null, and whose memory address (in the inferior) is
3525 ADDRESS. The type of the created value may differ from the passed
3526 type TYPE. Make sure to retrieve values new type after this call. */
3529 value_from_contents_and_address (struct type *type,
3530 const gdb_byte *valaddr,
3533 struct type *resolved_type = resolve_dynamic_type (type, valaddr, address);
3534 struct type *resolved_type_no_typedef = check_typedef (resolved_type);
3537 if (valaddr == NULL)
3538 v = allocate_value_lazy (resolved_type);
3540 v = value_from_contents (resolved_type, valaddr);
3541 if (TYPE_DATA_LOCATION (resolved_type_no_typedef) != NULL
3542 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef) == PROP_CONST)
3543 address = TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef);
3544 set_value_address (v, address);
3545 VALUE_LVAL (v) = lval_memory;
3549 /* Create a value of type TYPE holding the contents CONTENTS.
3550 The new value is `not_lval'. */
3553 value_from_contents (struct type *type, const gdb_byte *contents)
3555 struct value *result;
3557 result = allocate_value (type);
3558 memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type));
3563 value_from_double (struct type *type, DOUBLEST num)
3565 struct value *val = allocate_value (type);
3566 struct type *base_type = check_typedef (type);
3567 enum type_code code = TYPE_CODE (base_type);
3569 if (code == TYPE_CODE_FLT)
3571 store_typed_floating (value_contents_raw (val), base_type, num);
3574 error (_("Unexpected type encountered for floating constant."));
3580 value_from_decfloat (struct type *type, const gdb_byte *dec)
3582 struct value *val = allocate_value (type);
3584 memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
3588 /* Extract a value from the history file. Input will be of the form
3589 $digits or $$digits. See block comment above 'write_dollar_variable'
3593 value_from_history_ref (const char *h, const char **endp)
3605 /* Find length of numeral string. */
3606 for (; isdigit (h[len]); len++)
3609 /* Make sure numeral string is not part of an identifier. */
3610 if (h[len] == '_' || isalpha (h[len]))
3613 /* Now collect the index value. */
3618 /* For some bizarre reason, "$$" is equivalent to "$$1",
3619 rather than to "$$0" as it ought to be! */
3627 index = -strtol (&h[2], &local_end, 10);
3635 /* "$" is equivalent to "$0". */
3643 index = strtol (&h[1], &local_end, 10);
3648 return access_value_history (index);
3652 coerce_ref_if_computed (const struct value *arg)
3654 const struct lval_funcs *funcs;
3656 if (TYPE_CODE (check_typedef (value_type (arg))) != TYPE_CODE_REF)
3659 if (value_lval_const (arg) != lval_computed)
3662 funcs = value_computed_funcs (arg);
3663 if (funcs->coerce_ref == NULL)
3666 return funcs->coerce_ref (arg);
3669 /* Look at value.h for description. */
3672 readjust_indirect_value_type (struct value *value, struct type *enc_type,
3673 struct type *original_type,
3674 struct value *original_value)
3676 /* Re-adjust type. */
3677 deprecated_set_value_type (value, TYPE_TARGET_TYPE (original_type));
3679 /* Add embedding info. */
3680 set_value_enclosing_type (value, enc_type);
3681 set_value_embedded_offset (value, value_pointed_to_offset (original_value));
3683 /* We may be pointing to an object of some derived type. */
3684 return value_full_object (value, NULL, 0, 0, 0);
3688 coerce_ref (struct value *arg)
3690 struct type *value_type_arg_tmp = check_typedef (value_type (arg));
3691 struct value *retval;
3692 struct type *enc_type;
3694 retval = coerce_ref_if_computed (arg);
3698 if (TYPE_CODE (value_type_arg_tmp) != TYPE_CODE_REF)
3701 enc_type = check_typedef (value_enclosing_type (arg));
3702 enc_type = TYPE_TARGET_TYPE (enc_type);
3704 retval = value_at_lazy (enc_type,
3705 unpack_pointer (value_type (arg),
3706 value_contents (arg)));
3707 enc_type = value_type (retval);
3708 return readjust_indirect_value_type (retval, enc_type,
3709 value_type_arg_tmp, arg);
3713 coerce_array (struct value *arg)
3717 arg = coerce_ref (arg);
3718 type = check_typedef (value_type (arg));
3720 switch (TYPE_CODE (type))
3722 case TYPE_CODE_ARRAY:
3723 if (!TYPE_VECTOR (type) && current_language->c_style_arrays)
3724 arg = value_coerce_array (arg);
3726 case TYPE_CODE_FUNC:
3727 arg = value_coerce_function (arg);
3734 /* Return the return value convention that will be used for the
3737 enum return_value_convention
3738 struct_return_convention (struct gdbarch *gdbarch,
3739 struct value *function, struct type *value_type)
3741 enum type_code code = TYPE_CODE (value_type);
3743 if (code == TYPE_CODE_ERROR)
3744 error (_("Function return type unknown."));
3746 /* Probe the architecture for the return-value convention. */
3747 return gdbarch_return_value (gdbarch, function, value_type,
3751 /* Return true if the function returning the specified type is using
3752 the convention of returning structures in memory (passing in the
3753 address as a hidden first parameter). */
3756 using_struct_return (struct gdbarch *gdbarch,
3757 struct value *function, struct type *value_type)
3759 if (TYPE_CODE (value_type) == TYPE_CODE_VOID)
3760 /* A void return value is never in memory. See also corresponding
3761 code in "print_return_value". */
3764 return (struct_return_convention (gdbarch, function, value_type)
3765 != RETURN_VALUE_REGISTER_CONVENTION);
3768 /* Set the initialized field in a value struct. */
3771 set_value_initialized (struct value *val, int status)
3773 val->initialized = status;
3776 /* Return the initialized field in a value struct. */
3779 value_initialized (struct value *val)
3781 return val->initialized;
3784 /* Load the actual content of a lazy value. Fetch the data from the
3785 user's process and clear the lazy flag to indicate that the data in
3786 the buffer is valid.
3788 If the value is zero-length, we avoid calling read_memory, which
3789 would abort. We mark the value as fetched anyway -- all 0 bytes of
3793 value_fetch_lazy (struct value *val)
3795 gdb_assert (value_lazy (val));
3796 allocate_value_contents (val);
3797 /* A value is either lazy, or fully fetched. The
3798 availability/validity is only established as we try to fetch a
3800 gdb_assert (VEC_empty (range_s, val->optimized_out));
3801 gdb_assert (VEC_empty (range_s, val->unavailable));
3802 if (value_bitsize (val))
3804 /* To read a lazy bitfield, read the entire enclosing value. This
3805 prevents reading the same block of (possibly volatile) memory once
3806 per bitfield. It would be even better to read only the containing
3807 word, but we have no way to record that just specific bits of a
3808 value have been fetched. */
3809 struct type *type = check_typedef (value_type (val));
3810 struct value *parent = value_parent (val);
3812 if (value_lazy (parent))
3813 value_fetch_lazy (parent);
3815 unpack_value_bitfield (val,
3816 value_bitpos (val), value_bitsize (val),
3817 value_contents_for_printing (parent),
3818 value_offset (val), parent);
3820 else if (VALUE_LVAL (val) == lval_memory)
3822 CORE_ADDR addr = value_address (val);
3823 struct type *type = check_typedef (value_enclosing_type (val));
3825 if (TYPE_LENGTH (type))
3826 read_value_memory (val, 0, value_stack (val),
3827 addr, value_contents_all_raw (val),
3828 TYPE_LENGTH (type));
3830 else if (VALUE_LVAL (val) == lval_register)
3832 struct frame_info *frame;
3834 struct type *type = check_typedef (value_type (val));
3835 struct value *new_val = val, *mark = value_mark ();
3837 /* Offsets are not supported here; lazy register values must
3838 refer to the entire register. */
3839 gdb_assert (value_offset (val) == 0);
3841 while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val))
3843 struct frame_id frame_id = VALUE_FRAME_ID (new_val);
3845 frame = frame_find_by_id (frame_id);
3846 regnum = VALUE_REGNUM (new_val);
3848 gdb_assert (frame != NULL);
3850 /* Convertible register routines are used for multi-register
3851 values and for interpretation in different types
3852 (e.g. float or int from a double register). Lazy
3853 register values should have the register's natural type,
3854 so they do not apply. */
3855 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame),
3858 new_val = get_frame_register_value (frame, regnum);
3860 /* If we get another lazy lval_register value, it means the
3861 register is found by reading it from the next frame.
3862 get_frame_register_value should never return a value with
3863 the frame id pointing to FRAME. If it does, it means we
3864 either have two consecutive frames with the same frame id
3865 in the frame chain, or some code is trying to unwind
3866 behind get_prev_frame's back (e.g., a frame unwind
3867 sniffer trying to unwind), bypassing its validations. In
3868 any case, it should always be an internal error to end up
3869 in this situation. */
3870 if (VALUE_LVAL (new_val) == lval_register
3871 && value_lazy (new_val)
3872 && frame_id_eq (VALUE_FRAME_ID (new_val), frame_id))
3873 internal_error (__FILE__, __LINE__,
3874 _("infinite loop while fetching a register"));
3877 /* If it's still lazy (for instance, a saved register on the
3878 stack), fetch it. */
3879 if (value_lazy (new_val))
3880 value_fetch_lazy (new_val);
3882 /* Copy the contents and the unavailability/optimized-out
3883 meta-data from NEW_VAL to VAL. */
3884 set_value_lazy (val, 0);
3885 value_contents_copy (val, value_embedded_offset (val),
3886 new_val, value_embedded_offset (new_val),
3887 TYPE_LENGTH (type));
3891 struct gdbarch *gdbarch;
3892 frame = frame_find_by_id (VALUE_FRAME_ID (val));
3893 regnum = VALUE_REGNUM (val);
3894 gdbarch = get_frame_arch (frame);
3896 fprintf_unfiltered (gdb_stdlog,
3897 "{ value_fetch_lazy "
3898 "(frame=%d,regnum=%d(%s),...) ",
3899 frame_relative_level (frame), regnum,
3900 user_reg_map_regnum_to_name (gdbarch, regnum));
3902 fprintf_unfiltered (gdb_stdlog, "->");
3903 if (value_optimized_out (new_val))
3905 fprintf_unfiltered (gdb_stdlog, " ");
3906 val_print_optimized_out (new_val, gdb_stdlog);
3911 const gdb_byte *buf = value_contents (new_val);
3913 if (VALUE_LVAL (new_val) == lval_register)
3914 fprintf_unfiltered (gdb_stdlog, " register=%d",
3915 VALUE_REGNUM (new_val));
3916 else if (VALUE_LVAL (new_val) == lval_memory)
3917 fprintf_unfiltered (gdb_stdlog, " address=%s",
3919 value_address (new_val)));
3921 fprintf_unfiltered (gdb_stdlog, " computed");
3923 fprintf_unfiltered (gdb_stdlog, " bytes=");
3924 fprintf_unfiltered (gdb_stdlog, "[");
3925 for (i = 0; i < register_size (gdbarch, regnum); i++)
3926 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
3927 fprintf_unfiltered (gdb_stdlog, "]");
3930 fprintf_unfiltered (gdb_stdlog, " }\n");
3933 /* Dispose of the intermediate values. This prevents
3934 watchpoints from trying to watch the saved frame pointer. */
3935 value_free_to_mark (mark);
3937 else if (VALUE_LVAL (val) == lval_computed
3938 && value_computed_funcs (val)->read != NULL)
3939 value_computed_funcs (val)->read (val);
3941 internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));
3943 set_value_lazy (val, 0);
3946 /* Implementation of the convenience function $_isvoid. */
3948 static struct value *
3949 isvoid_internal_fn (struct gdbarch *gdbarch,
3950 const struct language_defn *language,
3951 void *cookie, int argc, struct value **argv)
3956 error (_("You must provide one argument for $_isvoid."));
3958 ret = TYPE_CODE (value_type (argv[0])) == TYPE_CODE_VOID;
3960 return value_from_longest (builtin_type (gdbarch)->builtin_int, ret);
3964 _initialize_values (void)
3966 add_cmd ("convenience", no_class, show_convenience, _("\
3967 Debugger convenience (\"$foo\") variables and functions.\n\
3968 Convenience variables are created when you assign them values;\n\
3969 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3971 A few convenience variables are given values automatically:\n\
3972 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3973 \"$__\" holds the contents of the last address examined with \"x\"."
3976 Convenience functions are defined via the Python API."
3979 add_alias_cmd ("conv", "convenience", no_class, 1, &showlist);
3981 add_cmd ("values", no_set_class, show_values, _("\
3982 Elements of value history around item number IDX (or last ten)."),
3985 add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
3986 Initialize a convenience variable if necessary.\n\
3987 init-if-undefined VARIABLE = EXPRESSION\n\
3988 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3989 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3990 VARIABLE is already initialized."));
3992 add_prefix_cmd ("function", no_class, function_command, _("\
3993 Placeholder command for showing help on convenience functions."),
3994 &functionlist, "function ", 0, &cmdlist);
3996 add_internal_function ("_isvoid", _("\
3997 Check whether an expression is void.\n\
3998 Usage: $_isvoid (expression)\n\
3999 Return 1 if the expression is void, zero otherwise."),
4000 isvoid_internal_fn, NULL);