1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2016 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"
45 /* Prototypes for exported functions. */
47 void _initialize_values (void);
49 /* Definition of a user function. */
50 struct internal_function
52 /* The name of the function. It is a bit odd to have this in the
53 function itself -- the user might use a differently-named
54 convenience variable to hold the function. */
58 internal_function_fn handler;
60 /* User data for the handler. */
64 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
68 /* Lowest offset in the range. */
71 /* Length of the range. */
75 typedef struct range range_s;
79 /* Returns true if the ranges defined by [offset1, offset1+len1) and
80 [offset2, offset2+len2) overlap. */
83 ranges_overlap (LONGEST offset1, LONGEST len1,
84 LONGEST offset2, LONGEST len2)
88 l = std::max (offset1, offset2);
89 h = std::min (offset1 + len1, offset2 + len2);
93 /* Returns true if the first argument is strictly less than the
94 second, useful for VEC_lower_bound. We keep ranges sorted by
95 offset and coalesce overlapping and contiguous ranges, so this just
96 compares the starting offset. */
99 range_lessthan (const range_s *r1, const range_s *r2)
101 return r1->offset < r2->offset;
104 /* Returns true if RANGES contains any range that overlaps [OFFSET,
108 ranges_contain (VEC(range_s) *ranges, LONGEST offset, LONGEST length)
113 what.offset = offset;
114 what.length = length;
116 /* We keep ranges sorted by offset and coalesce overlapping and
117 contiguous ranges, so to check if a range list contains a given
118 range, we can do a binary search for the position the given range
119 would be inserted if we only considered the starting OFFSET of
120 ranges. We call that position I. Since we also have LENGTH to
121 care for (this is a range afterall), we need to check if the
122 _previous_ range overlaps the I range. E.g.,
126 |---| |---| |------| ... |--|
131 In the case above, the binary search would return `I=1', meaning,
132 this OFFSET should be inserted at position 1, and the current
133 position 1 should be pushed further (and before 2). But, `0'
136 Then we need to check if the I range overlaps the I range itself.
141 |---| |---| |-------| ... |--|
147 i = VEC_lower_bound (range_s, ranges, &what, range_lessthan);
151 struct range *bef = VEC_index (range_s, ranges, i - 1);
153 if (ranges_overlap (bef->offset, bef->length, offset, length))
157 if (i < VEC_length (range_s, ranges))
159 struct range *r = VEC_index (range_s, ranges, i);
161 if (ranges_overlap (r->offset, r->length, offset, length))
168 static struct cmd_list_element *functionlist;
170 /* Note that the fields in this structure are arranged to save a bit
175 /* Type of value; either not an lval, or one of the various
176 different possible kinds of lval. */
179 /* Is it modifiable? Only relevant if lval != not_lval. */
180 unsigned int modifiable : 1;
182 /* If zero, contents of this value are in the contents field. If
183 nonzero, contents are in inferior. If the lval field is lval_memory,
184 the contents are in inferior memory at location.address plus offset.
185 The lval field may also be lval_register.
187 WARNING: This field is used by the code which handles watchpoints
188 (see breakpoint.c) to decide whether a particular value can be
189 watched by hardware watchpoints. If the lazy flag is set for
190 some member of a value chain, it is assumed that this member of
191 the chain doesn't need to be watched as part of watching the
192 value itself. This is how GDB avoids watching the entire struct
193 or array when the user wants to watch a single struct member or
194 array element. If you ever change the way lazy flag is set and
195 reset, be sure to consider this use as well! */
196 unsigned int lazy : 1;
198 /* If value is a variable, is it initialized or not. */
199 unsigned int initialized : 1;
201 /* If value is from the stack. If this is set, read_stack will be
202 used instead of read_memory to enable extra caching. */
203 unsigned int stack : 1;
205 /* If the value has been released. */
206 unsigned int released : 1;
208 /* Register number if the value is from a register. */
211 /* Location of value (if lval). */
214 /* If lval == lval_memory, this is the address in the inferior.
215 If lval == lval_register, this is the byte offset into the
216 registers structure. */
219 /* Pointer to internal variable. */
220 struct internalvar *internalvar;
222 /* Pointer to xmethod worker. */
223 struct xmethod_worker *xm_worker;
225 /* If lval == lval_computed, this is a set of function pointers
226 to use to access and describe the value, and a closure pointer
230 /* Functions to call. */
231 const struct lval_funcs *funcs;
233 /* Closure for those functions to use. */
238 /* Describes offset of a value within lval of a structure in target
239 addressable memory units. If lval == lval_memory, this is an offset to
240 the address. If lval == lval_register, this is a further offset from
241 location.address within the registers structure. Note also the member
242 embedded_offset below. */
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value *parent;
265 /* Frame register value is relative to. This will be described in
266 the lval enum above as "lval_register". */
267 struct frame_id frame_id;
269 /* Type of the value. */
272 /* If a value represents a C++ object, then the `type' field gives
273 the object's compile-time type. If the object actually belongs
274 to some class derived from `type', perhaps with other base
275 classes and additional members, then `type' is just a subobject
276 of the real thing, and the full object is probably larger than
277 `type' would suggest.
279 If `type' is a dynamic class (i.e. one with a vtable), then GDB
280 can actually determine the object's run-time type by looking at
281 the run-time type information in the vtable. When this
282 information is available, we may elect to read in the entire
283 object, for several reasons:
285 - When printing the value, the user would probably rather see the
286 full object, not just the limited portion apparent from the
289 - If `type' has virtual base classes, then even printing `type'
290 alone may require reaching outside the `type' portion of the
291 object to wherever the virtual base class has been stored.
293 When we store the entire object, `enclosing_type' is the run-time
294 type -- the complete object -- and `embedded_offset' is the
295 offset of `type' within that larger type, in target addressable memory
296 units. The value_contents() macro takes `embedded_offset' into account,
297 so most GDB code continues to see the `type' portion of the value, just
298 as the inferior would.
300 If `type' is a pointer to an object, then `enclosing_type' is a
301 pointer to the object's run-time type, and `pointed_to_offset' is
302 the offset in target addressable memory units from the full object
303 to the pointed-to object -- that is, the value `embedded_offset' would
304 have if we followed the pointer and fetched the complete object.
305 (I don't really see the point. Why not just determine the
306 run-time type when you indirect, and avoid the special case? The
307 contents don't matter until you indirect anyway.)
309 If we're not doing anything fancy, `enclosing_type' is equal to
310 `type', and `embedded_offset' is zero, so everything works
312 struct type *enclosing_type;
313 LONGEST embedded_offset;
314 LONGEST pointed_to_offset;
316 /* Values are stored in a chain, so that they can be deleted easily
317 over calls to the inferior. Values assigned to internal
318 variables, put into the value history or exposed to Python are
319 taken off this list. */
322 /* Actual contents of the value. Target byte-order. NULL or not
323 valid if lazy is nonzero. */
326 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
327 rather than available, since the common and default case is for a
328 value to be available. This is filled in at value read time.
329 The unavailable ranges are tracked in bits. Note that a contents
330 bit that has been optimized out doesn't really exist in the
331 program, so it can't be marked unavailable either. */
332 VEC(range_s) *unavailable;
334 /* Likewise, but for optimized out contents (a chunk of the value of
335 a variable that does not actually exist in the program). If LVAL
336 is lval_register, this is a register ($pc, $sp, etc., never a
337 program variable) that has not been saved in the frame. Not
338 saved registers and optimized-out program variables values are
339 treated pretty much the same, except not-saved registers have a
340 different string representation and related error strings. */
341 VEC(range_s) *optimized_out;
347 get_value_arch (const struct value *value)
349 return get_type_arch (value_type (value));
353 value_bits_available (const struct value *value, LONGEST offset, LONGEST length)
355 gdb_assert (!value->lazy);
357 return !ranges_contain (value->unavailable, offset, length);
361 value_bytes_available (const struct value *value,
362 LONGEST offset, LONGEST length)
364 return value_bits_available (value,
365 offset * TARGET_CHAR_BIT,
366 length * TARGET_CHAR_BIT);
370 value_bits_any_optimized_out (const struct value *value, int bit_offset, int bit_length)
372 gdb_assert (!value->lazy);
374 return ranges_contain (value->optimized_out, bit_offset, bit_length);
378 value_entirely_available (struct value *value)
380 /* We can only tell whether the whole value is available when we try
383 value_fetch_lazy (value);
385 if (VEC_empty (range_s, value->unavailable))
390 /* Returns true if VALUE is entirely covered by RANGES. If the value
391 is lazy, it'll be read now. Note that RANGE is a pointer to
392 pointer because reading the value might change *RANGE. */
395 value_entirely_covered_by_range_vector (struct value *value,
396 VEC(range_s) **ranges)
398 /* We can only tell whether the whole value is optimized out /
399 unavailable when we try to read it. */
401 value_fetch_lazy (value);
403 if (VEC_length (range_s, *ranges) == 1)
405 struct range *t = VEC_index (range_s, *ranges, 0);
408 && t->length == (TARGET_CHAR_BIT
409 * TYPE_LENGTH (value_enclosing_type (value))))
417 value_entirely_unavailable (struct value *value)
419 return value_entirely_covered_by_range_vector (value, &value->unavailable);
423 value_entirely_optimized_out (struct value *value)
425 return value_entirely_covered_by_range_vector (value, &value->optimized_out);
428 /* Insert into the vector pointed to by VECTORP the bit range starting of
429 OFFSET bits, and extending for the next LENGTH bits. */
432 insert_into_bit_range_vector (VEC(range_s) **vectorp,
433 LONGEST offset, LONGEST length)
438 /* Insert the range sorted. If there's overlap or the new range
439 would be contiguous with an existing range, merge. */
441 newr.offset = offset;
442 newr.length = length;
444 /* Do a binary search for the position the given range would be
445 inserted if we only considered the starting OFFSET of ranges.
446 Call that position I. Since we also have LENGTH to care for
447 (this is a range afterall), we need to check if the _previous_
448 range overlaps the I range. E.g., calling R the new range:
450 #1 - overlaps with previous
454 |---| |---| |------| ... |--|
459 In the case #1 above, the binary search would return `I=1',
460 meaning, this OFFSET should be inserted at position 1, and the
461 current position 1 should be pushed further (and become 2). But,
462 note that `0' overlaps with R, so we want to merge them.
464 A similar consideration needs to be taken if the new range would
465 be contiguous with the previous range:
467 #2 - contiguous with previous
471 |--| |---| |------| ... |--|
476 If there's no overlap with the previous range, as in:
478 #3 - not overlapping and not contiguous
482 |--| |---| |------| ... |--|
489 #4 - R is the range with lowest offset
493 |--| |---| |------| ... |--|
498 ... we just push the new range to I.
500 All the 4 cases above need to consider that the new range may
501 also overlap several of the ranges that follow, or that R may be
502 contiguous with the following range, and merge. E.g.,
504 #5 - overlapping following ranges
507 |------------------------|
508 |--| |---| |------| ... |--|
517 |--| |---| |------| ... |--|
524 i = VEC_lower_bound (range_s, *vectorp, &newr, range_lessthan);
527 struct range *bef = VEC_index (range_s, *vectorp, i - 1);
529 if (ranges_overlap (bef->offset, bef->length, offset, length))
532 ULONGEST l = std::min (bef->offset, offset);
533 ULONGEST h = std::max (bef->offset + bef->length, offset + length);
539 else if (offset == bef->offset + bef->length)
542 bef->length += length;
548 VEC_safe_insert (range_s, *vectorp, i, &newr);
554 VEC_safe_insert (range_s, *vectorp, i, &newr);
557 /* Check whether the ranges following the one we've just added or
558 touched can be folded in (#5 above). */
559 if (i + 1 < VEC_length (range_s, *vectorp))
566 /* Get the range we just touched. */
567 t = VEC_index (range_s, *vectorp, i);
571 for (; VEC_iterate (range_s, *vectorp, i, r); i++)
572 if (r->offset <= t->offset + t->length)
576 l = std::min (t->offset, r->offset);
577 h = std::max (t->offset + t->length, r->offset + r->length);
586 /* If we couldn't merge this one, we won't be able to
587 merge following ones either, since the ranges are
588 always sorted by OFFSET. */
593 VEC_block_remove (range_s, *vectorp, next, removed);
598 mark_value_bits_unavailable (struct value *value,
599 LONGEST offset, LONGEST length)
601 insert_into_bit_range_vector (&value->unavailable, offset, length);
605 mark_value_bytes_unavailable (struct value *value,
606 LONGEST offset, LONGEST length)
608 mark_value_bits_unavailable (value,
609 offset * TARGET_CHAR_BIT,
610 length * TARGET_CHAR_BIT);
613 /* Find the first range in RANGES that overlaps the range defined by
614 OFFSET and LENGTH, starting at element POS in the RANGES vector,
615 Returns the index into RANGES where such overlapping range was
616 found, or -1 if none was found. */
619 find_first_range_overlap (VEC(range_s) *ranges, int pos,
620 LONGEST offset, LONGEST length)
625 for (i = pos; VEC_iterate (range_s, ranges, i, r); i++)
626 if (ranges_overlap (r->offset, r->length, offset, length))
632 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
633 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
636 It must always be the case that:
637 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
639 It is assumed that memory can be accessed from:
640 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
642 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
643 / TARGET_CHAR_BIT) */
645 memcmp_with_bit_offsets (const gdb_byte *ptr1, size_t offset1_bits,
646 const gdb_byte *ptr2, size_t offset2_bits,
649 gdb_assert (offset1_bits % TARGET_CHAR_BIT
650 == offset2_bits % TARGET_CHAR_BIT);
652 if (offset1_bits % TARGET_CHAR_BIT != 0)
655 gdb_byte mask, b1, b2;
657 /* The offset from the base pointers PTR1 and PTR2 is not a complete
658 number of bytes. A number of bits up to either the next exact
659 byte boundary, or LENGTH_BITS (which ever is sooner) will be
661 bits = TARGET_CHAR_BIT - offset1_bits % TARGET_CHAR_BIT;
662 gdb_assert (bits < sizeof (mask) * TARGET_CHAR_BIT);
663 mask = (1 << bits) - 1;
665 if (length_bits < bits)
667 mask &= ~(gdb_byte) ((1 << (bits - length_bits)) - 1);
671 /* Now load the two bytes and mask off the bits we care about. */
672 b1 = *(ptr1 + offset1_bits / TARGET_CHAR_BIT) & mask;
673 b2 = *(ptr2 + offset2_bits / TARGET_CHAR_BIT) & mask;
678 /* Now update the length and offsets to take account of the bits
679 we've just compared. */
681 offset1_bits += bits;
682 offset2_bits += bits;
685 if (length_bits % TARGET_CHAR_BIT != 0)
689 gdb_byte mask, b1, b2;
691 /* The length is not an exact number of bytes. After the previous
692 IF.. block then the offsets are byte aligned, or the
693 length is zero (in which case this code is not reached). Compare
694 a number of bits at the end of the region, starting from an exact
696 bits = length_bits % TARGET_CHAR_BIT;
697 o1 = offset1_bits + length_bits - bits;
698 o2 = offset2_bits + length_bits - bits;
700 gdb_assert (bits < sizeof (mask) * TARGET_CHAR_BIT);
701 mask = ((1 << bits) - 1) << (TARGET_CHAR_BIT - bits);
703 gdb_assert (o1 % TARGET_CHAR_BIT == 0);
704 gdb_assert (o2 % TARGET_CHAR_BIT == 0);
706 b1 = *(ptr1 + o1 / TARGET_CHAR_BIT) & mask;
707 b2 = *(ptr2 + o2 / TARGET_CHAR_BIT) & mask;
717 /* We've now taken care of any stray "bits" at the start, or end of
718 the region to compare, the remainder can be covered with a simple
720 gdb_assert (offset1_bits % TARGET_CHAR_BIT == 0);
721 gdb_assert (offset2_bits % TARGET_CHAR_BIT == 0);
722 gdb_assert (length_bits % TARGET_CHAR_BIT == 0);
724 return memcmp (ptr1 + offset1_bits / TARGET_CHAR_BIT,
725 ptr2 + offset2_bits / TARGET_CHAR_BIT,
726 length_bits / TARGET_CHAR_BIT);
729 /* Length is zero, regions match. */
733 /* Helper struct for find_first_range_overlap_and_match and
734 value_contents_bits_eq. Keep track of which slot of a given ranges
735 vector have we last looked at. */
737 struct ranges_and_idx
740 VEC(range_s) *ranges;
742 /* The range we've last found in RANGES. Given ranges are sorted,
743 we can start the next lookup here. */
747 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
748 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
749 ranges starting at OFFSET2 bits. Return true if the ranges match
750 and fill in *L and *H with the overlapping window relative to
751 (both) OFFSET1 or OFFSET2. */
754 find_first_range_overlap_and_match (struct ranges_and_idx *rp1,
755 struct ranges_and_idx *rp2,
756 LONGEST offset1, LONGEST offset2,
757 LONGEST length, ULONGEST *l, ULONGEST *h)
759 rp1->idx = find_first_range_overlap (rp1->ranges, rp1->idx,
761 rp2->idx = find_first_range_overlap (rp2->ranges, rp2->idx,
764 if (rp1->idx == -1 && rp2->idx == -1)
770 else if (rp1->idx == -1 || rp2->idx == -1)
778 r1 = VEC_index (range_s, rp1->ranges, rp1->idx);
779 r2 = VEC_index (range_s, rp2->ranges, rp2->idx);
781 /* Get the unavailable windows intersected by the incoming
782 ranges. The first and last ranges that overlap the argument
783 range may be wider than said incoming arguments ranges. */
784 l1 = std::max (offset1, r1->offset);
785 h1 = std::min (offset1 + length, r1->offset + r1->length);
787 l2 = std::max (offset2, r2->offset);
788 h2 = std::min (offset2 + length, offset2 + r2->length);
790 /* Make them relative to the respective start offsets, so we can
791 compare them for equality. */
798 /* Different ranges, no match. */
799 if (l1 != l2 || h1 != h2)
808 /* Helper function for value_contents_eq. The only difference is that
809 this function is bit rather than byte based.
811 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
812 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
813 Return true if the available bits match. */
816 value_contents_bits_eq (const struct value *val1, int offset1,
817 const struct value *val2, int offset2,
820 /* Each array element corresponds to a ranges source (unavailable,
821 optimized out). '1' is for VAL1, '2' for VAL2. */
822 struct ranges_and_idx rp1[2], rp2[2];
824 /* See function description in value.h. */
825 gdb_assert (!val1->lazy && !val2->lazy);
827 /* We shouldn't be trying to compare past the end of the values. */
828 gdb_assert (offset1 + length
829 <= TYPE_LENGTH (val1->enclosing_type) * TARGET_CHAR_BIT);
830 gdb_assert (offset2 + length
831 <= TYPE_LENGTH (val2->enclosing_type) * TARGET_CHAR_BIT);
833 memset (&rp1, 0, sizeof (rp1));
834 memset (&rp2, 0, sizeof (rp2));
835 rp1[0].ranges = val1->unavailable;
836 rp2[0].ranges = val2->unavailable;
837 rp1[1].ranges = val1->optimized_out;
838 rp2[1].ranges = val2->optimized_out;
842 ULONGEST l = 0, h = 0; /* init for gcc -Wall */
845 for (i = 0; i < 2; i++)
847 ULONGEST l_tmp, h_tmp;
849 /* The contents only match equal if the invalid/unavailable
850 contents ranges match as well. */
851 if (!find_first_range_overlap_and_match (&rp1[i], &rp2[i],
852 offset1, offset2, length,
856 /* We're interested in the lowest/first range found. */
857 if (i == 0 || l_tmp < l)
864 /* Compare the available/valid contents. */
865 if (memcmp_with_bit_offsets (val1->contents, offset1,
866 val2->contents, offset2, l) != 0)
878 value_contents_eq (const struct value *val1, LONGEST offset1,
879 const struct value *val2, LONGEST offset2,
882 return value_contents_bits_eq (val1, offset1 * TARGET_CHAR_BIT,
883 val2, offset2 * TARGET_CHAR_BIT,
884 length * TARGET_CHAR_BIT);
887 /* Prototypes for local functions. */
889 static void show_values (char *, int);
891 static void show_convenience (char *, int);
894 /* The value-history records all the values printed
895 by print commands during this session. Each chunk
896 records 60 consecutive values. The first chunk on
897 the chain records the most recent values.
898 The total number of values is in value_history_count. */
900 #define VALUE_HISTORY_CHUNK 60
902 struct value_history_chunk
904 struct value_history_chunk *next;
905 struct value *values[VALUE_HISTORY_CHUNK];
908 /* Chain of chunks now in use. */
910 static struct value_history_chunk *value_history_chain;
912 static int value_history_count; /* Abs number of last entry stored. */
915 /* List of all value objects currently allocated
916 (except for those released by calls to release_value)
917 This is so they can be freed after each command. */
919 static struct value *all_values;
921 /* Allocate a lazy value for type TYPE. Its actual content is
922 "lazily" allocated too: the content field of the return value is
923 NULL; it will be allocated when it is fetched from the target. */
926 allocate_value_lazy (struct type *type)
930 /* Call check_typedef on our type to make sure that, if TYPE
931 is a TYPE_CODE_TYPEDEF, its length is set to the length
932 of the target type instead of zero. However, we do not
933 replace the typedef type by the target type, because we want
934 to keep the typedef in order to be able to set the VAL's type
935 description correctly. */
936 check_typedef (type);
938 val = XCNEW (struct value);
939 val->contents = NULL;
940 val->next = all_values;
943 val->enclosing_type = type;
944 VALUE_LVAL (val) = not_lval;
945 val->location.address = 0;
946 VALUE_FRAME_ID (val) = null_frame_id;
950 VALUE_REGNUM (val) = -1;
952 val->embedded_offset = 0;
953 val->pointed_to_offset = 0;
955 val->initialized = 1; /* Default to initialized. */
957 /* Values start out on the all_values chain. */
958 val->reference_count = 1;
963 /* The maximum size, in bytes, that GDB will try to allocate for a value.
964 The initial value of 64k was not selected for any specific reason, it is
965 just a reasonable starting point. */
967 static int max_value_size = 65536; /* 64k bytes */
969 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
970 LONGEST, otherwise GDB will not be able to parse integer values from the
971 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
972 be unable to parse "set max-value-size 2".
974 As we want a consistent GDB experience across hosts with different sizes
975 of LONGEST, this arbitrary minimum value was selected, so long as this
976 is bigger than LONGEST on all GDB supported hosts we're fine. */
978 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
979 gdb_static_assert (sizeof (LONGEST) <= MIN_VALUE_FOR_MAX_VALUE_SIZE);
981 /* Implement the "set max-value-size" command. */
984 set_max_value_size (char *args, int from_tty,
985 struct cmd_list_element *c)
987 gdb_assert (max_value_size == -1 || max_value_size >= 0);
989 if (max_value_size > -1 && max_value_size < MIN_VALUE_FOR_MAX_VALUE_SIZE)
991 max_value_size = MIN_VALUE_FOR_MAX_VALUE_SIZE;
992 error (_("max-value-size set too low, increasing to %d bytes"),
997 /* Implement the "show max-value-size" command. */
1000 show_max_value_size (struct ui_file *file, int from_tty,
1001 struct cmd_list_element *c, const char *value)
1003 if (max_value_size == -1)
1004 fprintf_filtered (file, _("Maximum value size is unlimited.\n"));
1006 fprintf_filtered (file, _("Maximum value size is %d bytes.\n"),
1010 /* Called before we attempt to allocate or reallocate a buffer for the
1011 contents of a value. TYPE is the type of the value for which we are
1012 allocating the buffer. If the buffer is too large (based on the user
1013 controllable setting) then throw an error. If this function returns
1014 then we should attempt to allocate the buffer. */
1017 check_type_length_before_alloc (const struct type *type)
1019 unsigned int length = TYPE_LENGTH (type);
1021 if (max_value_size > -1 && length > max_value_size)
1023 if (TYPE_NAME (type) != NULL)
1024 error (_("value of type `%s' requires %u bytes, which is more "
1025 "than max-value-size"), TYPE_NAME (type), length);
1027 error (_("value requires %u bytes, which is more than "
1028 "max-value-size"), length);
1032 /* Allocate the contents of VAL if it has not been allocated yet. */
1035 allocate_value_contents (struct value *val)
1039 check_type_length_before_alloc (val->enclosing_type);
1041 = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
1045 /* Allocate a value and its contents for type TYPE. */
1048 allocate_value (struct type *type)
1050 struct value *val = allocate_value_lazy (type);
1052 allocate_value_contents (val);
1057 /* Allocate a value that has the correct length
1058 for COUNT repetitions of type TYPE. */
1061 allocate_repeat_value (struct type *type, int count)
1063 int low_bound = current_language->string_lower_bound; /* ??? */
1064 /* FIXME-type-allocation: need a way to free this type when we are
1066 struct type *array_type
1067 = lookup_array_range_type (type, low_bound, count + low_bound - 1);
1069 return allocate_value (array_type);
1073 allocate_computed_value (struct type *type,
1074 const struct lval_funcs *funcs,
1077 struct value *v = allocate_value_lazy (type);
1079 VALUE_LVAL (v) = lval_computed;
1080 v->location.computed.funcs = funcs;
1081 v->location.computed.closure = closure;
1086 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1089 allocate_optimized_out_value (struct type *type)
1091 struct value *retval = allocate_value_lazy (type);
1093 mark_value_bytes_optimized_out (retval, 0, TYPE_LENGTH (type));
1094 set_value_lazy (retval, 0);
1098 /* Accessor methods. */
1101 value_next (const struct value *value)
1107 value_type (const struct value *value)
1112 deprecated_set_value_type (struct value *value, struct type *type)
1118 value_offset (const struct value *value)
1120 return value->offset;
1123 set_value_offset (struct value *value, LONGEST offset)
1125 value->offset = offset;
1129 value_bitpos (const struct value *value)
1131 return value->bitpos;
1134 set_value_bitpos (struct value *value, LONGEST bit)
1136 value->bitpos = bit;
1140 value_bitsize (const struct value *value)
1142 return value->bitsize;
1145 set_value_bitsize (struct value *value, LONGEST bit)
1147 value->bitsize = bit;
1151 value_parent (const struct value *value)
1153 return value->parent;
1159 set_value_parent (struct value *value, struct value *parent)
1161 struct value *old = value->parent;
1163 value->parent = parent;
1165 value_incref (parent);
1170 value_contents_raw (struct value *value)
1172 struct gdbarch *arch = get_value_arch (value);
1173 int unit_size = gdbarch_addressable_memory_unit_size (arch);
1175 allocate_value_contents (value);
1176 return value->contents + value->embedded_offset * unit_size;
1180 value_contents_all_raw (struct value *value)
1182 allocate_value_contents (value);
1183 return value->contents;
1187 value_enclosing_type (const struct value *value)
1189 return value->enclosing_type;
1192 /* Look at value.h for description. */
1195 value_actual_type (struct value *value, int resolve_simple_types,
1196 int *real_type_found)
1198 struct value_print_options opts;
1199 struct type *result;
1201 get_user_print_options (&opts);
1203 if (real_type_found)
1204 *real_type_found = 0;
1205 result = value_type (value);
1206 if (opts.objectprint)
1208 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1209 fetch its rtti type. */
1210 if ((TYPE_CODE (result) == TYPE_CODE_PTR
1211 || TYPE_CODE (result) == TYPE_CODE_REF)
1212 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result)))
1214 && !value_optimized_out (value))
1216 struct type *real_type;
1218 real_type = value_rtti_indirect_type (value, NULL, NULL, NULL);
1221 if (real_type_found)
1222 *real_type_found = 1;
1226 else if (resolve_simple_types)
1228 if (real_type_found)
1229 *real_type_found = 1;
1230 result = value_enclosing_type (value);
1238 error_value_optimized_out (void)
1240 error (_("value has been optimized out"));
1244 require_not_optimized_out (const struct value *value)
1246 if (!VEC_empty (range_s, value->optimized_out))
1248 if (value->lval == lval_register)
1249 error (_("register has not been saved in frame"));
1251 error_value_optimized_out ();
1256 require_available (const struct value *value)
1258 if (!VEC_empty (range_s, value->unavailable))
1259 throw_error (NOT_AVAILABLE_ERROR, _("value is not available"));
1263 value_contents_for_printing (struct value *value)
1266 value_fetch_lazy (value);
1267 return value->contents;
1271 value_contents_for_printing_const (const struct value *value)
1273 gdb_assert (!value->lazy);
1274 return value->contents;
1278 value_contents_all (struct value *value)
1280 const gdb_byte *result = value_contents_for_printing (value);
1281 require_not_optimized_out (value);
1282 require_available (value);
1286 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1287 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1290 ranges_copy_adjusted (VEC (range_s) **dst_range, int dst_bit_offset,
1291 VEC (range_s) *src_range, int src_bit_offset,
1297 for (i = 0; VEC_iterate (range_s, src_range, i, r); i++)
1301 l = std::max (r->offset, (LONGEST) src_bit_offset);
1302 h = std::min (r->offset + r->length,
1303 (LONGEST) src_bit_offset + bit_length);
1306 insert_into_bit_range_vector (dst_range,
1307 dst_bit_offset + (l - src_bit_offset),
1312 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1313 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1316 value_ranges_copy_adjusted (struct value *dst, int dst_bit_offset,
1317 const struct value *src, int src_bit_offset,
1320 ranges_copy_adjusted (&dst->unavailable, dst_bit_offset,
1321 src->unavailable, src_bit_offset,
1323 ranges_copy_adjusted (&dst->optimized_out, dst_bit_offset,
1324 src->optimized_out, src_bit_offset,
1328 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1329 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1330 contents, starting at DST_OFFSET. If unavailable contents are
1331 being copied from SRC, the corresponding DST contents are marked
1332 unavailable accordingly. Neither DST nor SRC may be lazy
1335 It is assumed the contents of DST in the [DST_OFFSET,
1336 DST_OFFSET+LENGTH) range are wholly available. */
1339 value_contents_copy_raw (struct value *dst, LONGEST dst_offset,
1340 struct value *src, LONGEST src_offset, LONGEST length)
1342 LONGEST src_bit_offset, dst_bit_offset, bit_length;
1343 struct gdbarch *arch = get_value_arch (src);
1344 int unit_size = gdbarch_addressable_memory_unit_size (arch);
1346 /* A lazy DST would make that this copy operation useless, since as
1347 soon as DST's contents were un-lazied (by a later value_contents
1348 call, say), the contents would be overwritten. A lazy SRC would
1349 mean we'd be copying garbage. */
1350 gdb_assert (!dst->lazy && !src->lazy);
1352 /* The overwritten DST range gets unavailability ORed in, not
1353 replaced. Make sure to remember to implement replacing if it
1354 turns out actually necessary. */
1355 gdb_assert (value_bytes_available (dst, dst_offset, length));
1356 gdb_assert (!value_bits_any_optimized_out (dst,
1357 TARGET_CHAR_BIT * dst_offset,
1358 TARGET_CHAR_BIT * length));
1360 /* Copy the data. */
1361 memcpy (value_contents_all_raw (dst) + dst_offset * unit_size,
1362 value_contents_all_raw (src) + src_offset * unit_size,
1363 length * unit_size);
1365 /* Copy the meta-data, adjusted. */
1366 src_bit_offset = src_offset * unit_size * HOST_CHAR_BIT;
1367 dst_bit_offset = dst_offset * unit_size * HOST_CHAR_BIT;
1368 bit_length = length * unit_size * HOST_CHAR_BIT;
1370 value_ranges_copy_adjusted (dst, dst_bit_offset,
1371 src, src_bit_offset,
1375 /* Copy LENGTH bytes of SRC value's (all) contents
1376 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1377 (all) contents, starting at DST_OFFSET. If unavailable contents
1378 are being copied from SRC, the corresponding DST contents are
1379 marked unavailable accordingly. DST must not be lazy. If SRC is
1380 lazy, it will be fetched now.
1382 It is assumed the contents of DST in the [DST_OFFSET,
1383 DST_OFFSET+LENGTH) range are wholly available. */
1386 value_contents_copy (struct value *dst, LONGEST dst_offset,
1387 struct value *src, LONGEST src_offset, LONGEST length)
1390 value_fetch_lazy (src);
1392 value_contents_copy_raw (dst, dst_offset, src, src_offset, length);
1396 value_lazy (const struct value *value)
1402 set_value_lazy (struct value *value, int val)
1408 value_stack (const struct value *value)
1410 return value->stack;
1414 set_value_stack (struct value *value, int val)
1420 value_contents (struct value *value)
1422 const gdb_byte *result = value_contents_writeable (value);
1423 require_not_optimized_out (value);
1424 require_available (value);
1429 value_contents_writeable (struct value *value)
1432 value_fetch_lazy (value);
1433 return value_contents_raw (value);
1437 value_optimized_out (struct value *value)
1439 /* We can only know if a value is optimized out once we have tried to
1441 if (VEC_empty (range_s, value->optimized_out) && value->lazy)
1445 value_fetch_lazy (value);
1447 CATCH (ex, RETURN_MASK_ERROR)
1449 /* Fall back to checking value->optimized_out. */
1454 return !VEC_empty (range_s, value->optimized_out);
1457 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1458 the following LENGTH bytes. */
1461 mark_value_bytes_optimized_out (struct value *value, int offset, int length)
1463 mark_value_bits_optimized_out (value,
1464 offset * TARGET_CHAR_BIT,
1465 length * TARGET_CHAR_BIT);
1471 mark_value_bits_optimized_out (struct value *value,
1472 LONGEST offset, LONGEST length)
1474 insert_into_bit_range_vector (&value->optimized_out, offset, length);
1478 value_bits_synthetic_pointer (const struct value *value,
1479 LONGEST offset, LONGEST length)
1481 if (value->lval != lval_computed
1482 || !value->location.computed.funcs->check_synthetic_pointer)
1484 return value->location.computed.funcs->check_synthetic_pointer (value,
1490 value_embedded_offset (const struct value *value)
1492 return value->embedded_offset;
1496 set_value_embedded_offset (struct value *value, LONGEST val)
1498 value->embedded_offset = val;
1502 value_pointed_to_offset (const struct value *value)
1504 return value->pointed_to_offset;
1508 set_value_pointed_to_offset (struct value *value, LONGEST val)
1510 value->pointed_to_offset = val;
1513 const struct lval_funcs *
1514 value_computed_funcs (const struct value *v)
1516 gdb_assert (value_lval_const (v) == lval_computed);
1518 return v->location.computed.funcs;
1522 value_computed_closure (const struct value *v)
1524 gdb_assert (v->lval == lval_computed);
1526 return v->location.computed.closure;
1530 deprecated_value_lval_hack (struct value *value)
1532 return &value->lval;
1536 value_lval_const (const struct value *value)
1542 value_address (const struct value *value)
1544 if (value->lval == lval_internalvar
1545 || value->lval == lval_internalvar_component
1546 || value->lval == lval_xcallable)
1548 if (value->parent != NULL)
1549 return value_address (value->parent) + value->offset;
1550 if (NULL != TYPE_DATA_LOCATION (value_type (value)))
1552 gdb_assert (PROP_CONST == TYPE_DATA_LOCATION_KIND (value_type (value)));
1553 return TYPE_DATA_LOCATION_ADDR (value_type (value));
1556 return value->location.address + value->offset;
1560 value_raw_address (const struct value *value)
1562 if (value->lval == lval_internalvar
1563 || value->lval == lval_internalvar_component
1564 || value->lval == lval_xcallable)
1566 return value->location.address;
1570 set_value_address (struct value *value, CORE_ADDR addr)
1572 gdb_assert (value->lval != lval_internalvar
1573 && value->lval != lval_internalvar_component
1574 && value->lval != lval_xcallable);
1575 value->location.address = addr;
1578 struct internalvar **
1579 deprecated_value_internalvar_hack (struct value *value)
1581 return &value->location.internalvar;
1585 deprecated_value_frame_id_hack (struct value *value)
1587 return &value->frame_id;
1591 deprecated_value_regnum_hack (struct value *value)
1593 return &value->regnum;
1597 deprecated_value_modifiable (const struct value *value)
1599 return value->modifiable;
1602 /* Return a mark in the value chain. All values allocated after the
1603 mark is obtained (except for those released) are subject to being freed
1604 if a subsequent value_free_to_mark is passed the mark. */
1611 /* Take a reference to VAL. VAL will not be deallocated until all
1612 references are released. */
1615 value_incref (struct value *val)
1617 val->reference_count++;
1620 /* Release a reference to VAL, which was acquired with value_incref.
1621 This function is also called to deallocate values from the value
1625 value_free (struct value *val)
1629 gdb_assert (val->reference_count > 0);
1630 val->reference_count--;
1631 if (val->reference_count > 0)
1634 /* If there's an associated parent value, drop our reference to
1636 if (val->parent != NULL)
1637 value_free (val->parent);
1639 if (VALUE_LVAL (val) == lval_computed)
1641 const struct lval_funcs *funcs = val->location.computed.funcs;
1643 if (funcs->free_closure)
1644 funcs->free_closure (val);
1646 else if (VALUE_LVAL (val) == lval_xcallable)
1647 free_xmethod_worker (val->location.xm_worker);
1649 xfree (val->contents);
1650 VEC_free (range_s, val->unavailable);
1655 /* Free all values allocated since MARK was obtained by value_mark
1656 (except for those released). */
1658 value_free_to_mark (const struct value *mark)
1663 for (val = all_values; val && val != mark; val = next)
1672 /* Free all the values that have been allocated (except for those released).
1673 Call after each command, successful or not.
1674 In practice this is called before each command, which is sufficient. */
1677 free_all_values (void)
1682 for (val = all_values; val; val = next)
1692 /* Frees all the elements in a chain of values. */
1695 free_value_chain (struct value *v)
1701 next = value_next (v);
1706 /* Remove VAL from the chain all_values
1707 so it will not be freed automatically. */
1710 release_value (struct value *val)
1714 if (all_values == val)
1716 all_values = val->next;
1722 for (v = all_values; v; v = v->next)
1726 v->next = val->next;
1734 /* If the value is not already released, release it.
1735 If the value is already released, increment its reference count.
1736 That is, this function ensures that the value is released from the
1737 value chain and that the caller owns a reference to it. */
1740 release_value_or_incref (struct value *val)
1745 release_value (val);
1748 /* Release all values up to mark */
1750 value_release_to_mark (const struct value *mark)
1755 for (val = next = all_values; next; next = next->next)
1757 if (next->next == mark)
1759 all_values = next->next;
1769 /* Return a copy of the value ARG.
1770 It contains the same contents, for same memory address,
1771 but it's a different block of storage. */
1774 value_copy (struct value *arg)
1776 struct type *encl_type = value_enclosing_type (arg);
1779 if (value_lazy (arg))
1780 val = allocate_value_lazy (encl_type);
1782 val = allocate_value (encl_type);
1783 val->type = arg->type;
1784 VALUE_LVAL (val) = VALUE_LVAL (arg);
1785 val->location = arg->location;
1786 val->offset = arg->offset;
1787 val->bitpos = arg->bitpos;
1788 val->bitsize = arg->bitsize;
1789 VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
1790 VALUE_REGNUM (val) = VALUE_REGNUM (arg);
1791 val->lazy = arg->lazy;
1792 val->embedded_offset = value_embedded_offset (arg);
1793 val->pointed_to_offset = arg->pointed_to_offset;
1794 val->modifiable = arg->modifiable;
1795 if (!value_lazy (val))
1797 memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
1798 TYPE_LENGTH (value_enclosing_type (arg)));
1801 val->unavailable = VEC_copy (range_s, arg->unavailable);
1802 val->optimized_out = VEC_copy (range_s, arg->optimized_out);
1803 set_value_parent (val, arg->parent);
1804 if (VALUE_LVAL (val) == lval_computed)
1806 const struct lval_funcs *funcs = val->location.computed.funcs;
1808 if (funcs->copy_closure)
1809 val->location.computed.closure = funcs->copy_closure (val);
1814 /* Return a "const" and/or "volatile" qualified version of the value V.
1815 If CNST is true, then the returned value will be qualified with
1817 if VOLTL is true, then the returned value will be qualified with
1821 make_cv_value (int cnst, int voltl, struct value *v)
1823 struct type *val_type = value_type (v);
1824 struct type *enclosing_type = value_enclosing_type (v);
1825 struct value *cv_val = value_copy (v);
1827 deprecated_set_value_type (cv_val,
1828 make_cv_type (cnst, voltl, val_type, NULL));
1829 set_value_enclosing_type (cv_val,
1830 make_cv_type (cnst, voltl, enclosing_type, NULL));
1835 /* Return a version of ARG that is non-lvalue. */
1838 value_non_lval (struct value *arg)
1840 if (VALUE_LVAL (arg) != not_lval)
1842 struct type *enc_type = value_enclosing_type (arg);
1843 struct value *val = allocate_value (enc_type);
1845 memcpy (value_contents_all_raw (val), value_contents_all (arg),
1846 TYPE_LENGTH (enc_type));
1847 val->type = arg->type;
1848 set_value_embedded_offset (val, value_embedded_offset (arg));
1849 set_value_pointed_to_offset (val, value_pointed_to_offset (arg));
1855 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1858 value_force_lval (struct value *v, CORE_ADDR addr)
1860 gdb_assert (VALUE_LVAL (v) == not_lval);
1862 write_memory (addr, value_contents_raw (v), TYPE_LENGTH (value_type (v)));
1863 v->lval = lval_memory;
1864 v->location.address = addr;
1868 set_value_component_location (struct value *component,
1869 const struct value *whole)
1873 gdb_assert (whole->lval != lval_xcallable);
1875 if (whole->lval == lval_internalvar)
1876 VALUE_LVAL (component) = lval_internalvar_component;
1878 VALUE_LVAL (component) = whole->lval;
1880 component->location = whole->location;
1881 if (whole->lval == lval_computed)
1883 const struct lval_funcs *funcs = whole->location.computed.funcs;
1885 if (funcs->copy_closure)
1886 component->location.computed.closure = funcs->copy_closure (whole);
1889 /* If type has a dynamic resolved location property
1890 update it's value address. */
1891 type = value_type (whole);
1892 if (NULL != TYPE_DATA_LOCATION (type)
1893 && TYPE_DATA_LOCATION_KIND (type) == PROP_CONST)
1894 set_value_address (component, TYPE_DATA_LOCATION_ADDR (type));
1897 /* Access to the value history. */
1899 /* Record a new value in the value history.
1900 Returns the absolute history index of the entry. */
1903 record_latest_value (struct value *val)
1907 /* We don't want this value to have anything to do with the inferior anymore.
1908 In particular, "set $1 = 50" should not affect the variable from which
1909 the value was taken, and fast watchpoints should be able to assume that
1910 a value on the value history never changes. */
1911 if (value_lazy (val))
1912 value_fetch_lazy (val);
1913 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1914 from. This is a bit dubious, because then *&$1 does not just return $1
1915 but the current contents of that location. c'est la vie... */
1916 val->modifiable = 0;
1918 /* The value may have already been released, in which case we're adding a
1919 new reference for its entry in the history. That is why we call
1920 release_value_or_incref here instead of release_value. */
1921 release_value_or_incref (val);
1923 /* Here we treat value_history_count as origin-zero
1924 and applying to the value being stored now. */
1926 i = value_history_count % VALUE_HISTORY_CHUNK;
1929 struct value_history_chunk *newobj = XCNEW (struct value_history_chunk);
1931 newobj->next = value_history_chain;
1932 value_history_chain = newobj;
1935 value_history_chain->values[i] = val;
1937 /* Now we regard value_history_count as origin-one
1938 and applying to the value just stored. */
1940 return ++value_history_count;
1943 /* Return a copy of the value in the history with sequence number NUM. */
1946 access_value_history (int num)
1948 struct value_history_chunk *chunk;
1953 absnum += value_history_count;
1958 error (_("The history is empty."));
1960 error (_("There is only one value in the history."));
1962 error (_("History does not go back to $$%d."), -num);
1964 if (absnum > value_history_count)
1965 error (_("History has not yet reached $%d."), absnum);
1969 /* Now absnum is always absolute and origin zero. */
1971 chunk = value_history_chain;
1972 for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK
1973 - absnum / VALUE_HISTORY_CHUNK;
1975 chunk = chunk->next;
1977 return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
1981 show_values (char *num_exp, int from_tty)
1989 /* "show values +" should print from the stored position.
1990 "show values <exp>" should print around value number <exp>. */
1991 if (num_exp[0] != '+' || num_exp[1] != '\0')
1992 num = parse_and_eval_long (num_exp) - 5;
1996 /* "show values" means print the last 10 values. */
1997 num = value_history_count - 9;
2003 for (i = num; i < num + 10 && i <= value_history_count; i++)
2005 struct value_print_options opts;
2007 val = access_value_history (i);
2008 printf_filtered (("$%d = "), i);
2009 get_user_print_options (&opts);
2010 value_print (val, gdb_stdout, &opts);
2011 printf_filtered (("\n"));
2014 /* The next "show values +" should start after what we just printed. */
2017 /* Hitting just return after this command should do the same thing as
2018 "show values +". If num_exp is null, this is unnecessary, since
2019 "show values +" is not useful after "show values". */
2020 if (from_tty && num_exp)
2027 enum internalvar_kind
2029 /* The internal variable is empty. */
2032 /* The value of the internal variable is provided directly as
2033 a GDB value object. */
2036 /* A fresh value is computed via a call-back routine on every
2037 access to the internal variable. */
2038 INTERNALVAR_MAKE_VALUE,
2040 /* The internal variable holds a GDB internal convenience function. */
2041 INTERNALVAR_FUNCTION,
2043 /* The variable holds an integer value. */
2044 INTERNALVAR_INTEGER,
2046 /* The variable holds a GDB-provided string. */
2050 union internalvar_data
2052 /* A value object used with INTERNALVAR_VALUE. */
2053 struct value *value;
2055 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
2058 /* The functions to call. */
2059 const struct internalvar_funcs *functions;
2061 /* The function's user-data. */
2065 /* The internal function used with INTERNALVAR_FUNCTION. */
2068 struct internal_function *function;
2069 /* True if this is the canonical name for the function. */
2073 /* An integer value used with INTERNALVAR_INTEGER. */
2076 /* If type is non-NULL, it will be used as the type to generate
2077 a value for this internal variable. If type is NULL, a default
2078 integer type for the architecture is used. */
2083 /* A string value used with INTERNALVAR_STRING. */
2087 /* Internal variables. These are variables within the debugger
2088 that hold values assigned by debugger commands.
2089 The user refers to them with a '$' prefix
2090 that does not appear in the variable names stored internally. */
2094 struct internalvar *next;
2097 /* We support various different kinds of content of an internal variable.
2098 enum internalvar_kind specifies the kind, and union internalvar_data
2099 provides the data associated with this particular kind. */
2101 enum internalvar_kind kind;
2103 union internalvar_data u;
2106 static struct internalvar *internalvars;
2108 /* If the variable does not already exist create it and give it the
2109 value given. If no value is given then the default is zero. */
2111 init_if_undefined_command (char* args, int from_tty)
2113 struct internalvar* intvar;
2115 /* Parse the expression - this is taken from set_command(). */
2116 struct expression *expr = parse_expression (args);
2117 register struct cleanup *old_chain =
2118 make_cleanup (free_current_contents, &expr);
2120 /* Validate the expression.
2121 Was the expression an assignment?
2122 Or even an expression at all? */
2123 if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
2124 error (_("Init-if-undefined requires an assignment expression."));
2126 /* Extract the variable from the parsed expression.
2127 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
2128 if (expr->elts[1].opcode != OP_INTERNALVAR)
2129 error (_("The first parameter to init-if-undefined "
2130 "should be a GDB variable."));
2131 intvar = expr->elts[2].internalvar;
2133 /* Only evaluate the expression if the lvalue is void.
2134 This may still fail if the expresssion is invalid. */
2135 if (intvar->kind == INTERNALVAR_VOID)
2136 evaluate_expression (expr);
2138 do_cleanups (old_chain);
2142 /* Look up an internal variable with name NAME. NAME should not
2143 normally include a dollar sign.
2145 If the specified internal variable does not exist,
2146 the return value is NULL. */
2148 struct internalvar *
2149 lookup_only_internalvar (const char *name)
2151 struct internalvar *var;
2153 for (var = internalvars; var; var = var->next)
2154 if (strcmp (var->name, name) == 0)
2160 /* Complete NAME by comparing it to the names of internal variables.
2161 Returns a vector of newly allocated strings, or NULL if no matches
2165 complete_internalvar (const char *name)
2167 VEC (char_ptr) *result = NULL;
2168 struct internalvar *var;
2171 len = strlen (name);
2173 for (var = internalvars; var; var = var->next)
2174 if (strncmp (var->name, name, len) == 0)
2176 char *r = xstrdup (var->name);
2178 VEC_safe_push (char_ptr, result, r);
2184 /* Create an internal variable with name NAME and with a void value.
2185 NAME should not normally include a dollar sign. */
2187 struct internalvar *
2188 create_internalvar (const char *name)
2190 struct internalvar *var = XNEW (struct internalvar);
2192 var->name = concat (name, (char *)NULL);
2193 var->kind = INTERNALVAR_VOID;
2194 var->next = internalvars;
2199 /* Create an internal variable with name NAME and register FUN as the
2200 function that value_of_internalvar uses to create a value whenever
2201 this variable is referenced. NAME should not normally include a
2202 dollar sign. DATA is passed uninterpreted to FUN when it is
2203 called. CLEANUP, if not NULL, is called when the internal variable
2204 is destroyed. It is passed DATA as its only argument. */
2206 struct internalvar *
2207 create_internalvar_type_lazy (const char *name,
2208 const struct internalvar_funcs *funcs,
2211 struct internalvar *var = create_internalvar (name);
2213 var->kind = INTERNALVAR_MAKE_VALUE;
2214 var->u.make_value.functions = funcs;
2215 var->u.make_value.data = data;
2219 /* See documentation in value.h. */
2222 compile_internalvar_to_ax (struct internalvar *var,
2223 struct agent_expr *expr,
2224 struct axs_value *value)
2226 if (var->kind != INTERNALVAR_MAKE_VALUE
2227 || var->u.make_value.functions->compile_to_ax == NULL)
2230 var->u.make_value.functions->compile_to_ax (var, expr, value,
2231 var->u.make_value.data);
2235 /* Look up an internal variable with name NAME. NAME should not
2236 normally include a dollar sign.
2238 If the specified internal variable does not exist,
2239 one is created, with a void value. */
2241 struct internalvar *
2242 lookup_internalvar (const char *name)
2244 struct internalvar *var;
2246 var = lookup_only_internalvar (name);
2250 return create_internalvar (name);
2253 /* Return current value of internal variable VAR. For variables that
2254 are not inherently typed, use a value type appropriate for GDBARCH. */
2257 value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
2260 struct trace_state_variable *tsv;
2262 /* If there is a trace state variable of the same name, assume that
2263 is what we really want to see. */
2264 tsv = find_trace_state_variable (var->name);
2267 tsv->value_known = target_get_trace_state_variable_value (tsv->number,
2269 if (tsv->value_known)
2270 val = value_from_longest (builtin_type (gdbarch)->builtin_int64,
2273 val = allocate_value (builtin_type (gdbarch)->builtin_void);
2279 case INTERNALVAR_VOID:
2280 val = allocate_value (builtin_type (gdbarch)->builtin_void);
2283 case INTERNALVAR_FUNCTION:
2284 val = allocate_value (builtin_type (gdbarch)->internal_fn);
2287 case INTERNALVAR_INTEGER:
2288 if (!var->u.integer.type)
2289 val = value_from_longest (builtin_type (gdbarch)->builtin_int,
2290 var->u.integer.val);
2292 val = value_from_longest (var->u.integer.type, var->u.integer.val);
2295 case INTERNALVAR_STRING:
2296 val = value_cstring (var->u.string, strlen (var->u.string),
2297 builtin_type (gdbarch)->builtin_char);
2300 case INTERNALVAR_VALUE:
2301 val = value_copy (var->u.value);
2302 if (value_lazy (val))
2303 value_fetch_lazy (val);
2306 case INTERNALVAR_MAKE_VALUE:
2307 val = (*var->u.make_value.functions->make_value) (gdbarch, var,
2308 var->u.make_value.data);
2312 internal_error (__FILE__, __LINE__, _("bad kind"));
2315 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2316 on this value go back to affect the original internal variable.
2318 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2319 no underlying modifyable state in the internal variable.
2321 Likewise, if the variable's value is a computed lvalue, we want
2322 references to it to produce another computed lvalue, where
2323 references and assignments actually operate through the
2324 computed value's functions.
2326 This means that internal variables with computed values
2327 behave a little differently from other internal variables:
2328 assignments to them don't just replace the previous value
2329 altogether. At the moment, this seems like the behavior we
2332 if (var->kind != INTERNALVAR_MAKE_VALUE
2333 && val->lval != lval_computed)
2335 VALUE_LVAL (val) = lval_internalvar;
2336 VALUE_INTERNALVAR (val) = var;
2343 get_internalvar_integer (struct internalvar *var, LONGEST *result)
2345 if (var->kind == INTERNALVAR_INTEGER)
2347 *result = var->u.integer.val;
2351 if (var->kind == INTERNALVAR_VALUE)
2353 struct type *type = check_typedef (value_type (var->u.value));
2355 if (TYPE_CODE (type) == TYPE_CODE_INT)
2357 *result = value_as_long (var->u.value);
2366 get_internalvar_function (struct internalvar *var,
2367 struct internal_function **result)
2371 case INTERNALVAR_FUNCTION:
2372 *result = var->u.fn.function;
2381 set_internalvar_component (struct internalvar *var,
2382 LONGEST offset, LONGEST bitpos,
2383 LONGEST bitsize, struct value *newval)
2386 struct gdbarch *arch;
2391 case INTERNALVAR_VALUE:
2392 addr = value_contents_writeable (var->u.value);
2393 arch = get_value_arch (var->u.value);
2394 unit_size = gdbarch_addressable_memory_unit_size (arch);
2397 modify_field (value_type (var->u.value), addr + offset,
2398 value_as_long (newval), bitpos, bitsize);
2400 memcpy (addr + offset * unit_size, value_contents (newval),
2401 TYPE_LENGTH (value_type (newval)));
2405 /* We can never get a component of any other kind. */
2406 internal_error (__FILE__, __LINE__, _("set_internalvar_component"));
2411 set_internalvar (struct internalvar *var, struct value *val)
2413 enum internalvar_kind new_kind;
2414 union internalvar_data new_data = { 0 };
2416 if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
2417 error (_("Cannot overwrite convenience function %s"), var->name);
2419 /* Prepare new contents. */
2420 switch (TYPE_CODE (check_typedef (value_type (val))))
2422 case TYPE_CODE_VOID:
2423 new_kind = INTERNALVAR_VOID;
2426 case TYPE_CODE_INTERNAL_FUNCTION:
2427 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
2428 new_kind = INTERNALVAR_FUNCTION;
2429 get_internalvar_function (VALUE_INTERNALVAR (val),
2430 &new_data.fn.function);
2431 /* Copies created here are never canonical. */
2435 new_kind = INTERNALVAR_VALUE;
2436 new_data.value = value_copy (val);
2437 new_data.value->modifiable = 1;
2439 /* Force the value to be fetched from the target now, to avoid problems
2440 later when this internalvar is referenced and the target is gone or
2442 if (value_lazy (new_data.value))
2443 value_fetch_lazy (new_data.value);
2445 /* Release the value from the value chain to prevent it from being
2446 deleted by free_all_values. From here on this function should not
2447 call error () until new_data is installed into the var->u to avoid
2449 release_value (new_data.value);
2451 /* Internal variables which are created from values with a dynamic
2452 location don't need the location property of the origin anymore.
2453 The resolved dynamic location is used prior then any other address
2454 when accessing the value.
2455 If we keep it, we would still refer to the origin value.
2456 Remove the location property in case it exist. */
2457 remove_dyn_prop (DYN_PROP_DATA_LOCATION, value_type (new_data.value));
2462 /* Clean up old contents. */
2463 clear_internalvar (var);
2466 var->kind = new_kind;
2468 /* End code which must not call error(). */
2472 set_internalvar_integer (struct internalvar *var, LONGEST l)
2474 /* Clean up old contents. */
2475 clear_internalvar (var);
2477 var->kind = INTERNALVAR_INTEGER;
2478 var->u.integer.type = NULL;
2479 var->u.integer.val = l;
2483 set_internalvar_string (struct internalvar *var, const char *string)
2485 /* Clean up old contents. */
2486 clear_internalvar (var);
2488 var->kind = INTERNALVAR_STRING;
2489 var->u.string = xstrdup (string);
2493 set_internalvar_function (struct internalvar *var, struct internal_function *f)
2495 /* Clean up old contents. */
2496 clear_internalvar (var);
2498 var->kind = INTERNALVAR_FUNCTION;
2499 var->u.fn.function = f;
2500 var->u.fn.canonical = 1;
2501 /* Variables installed here are always the canonical version. */
2505 clear_internalvar (struct internalvar *var)
2507 /* Clean up old contents. */
2510 case INTERNALVAR_VALUE:
2511 value_free (var->u.value);
2514 case INTERNALVAR_STRING:
2515 xfree (var->u.string);
2518 case INTERNALVAR_MAKE_VALUE:
2519 if (var->u.make_value.functions->destroy != NULL)
2520 var->u.make_value.functions->destroy (var->u.make_value.data);
2527 /* Reset to void kind. */
2528 var->kind = INTERNALVAR_VOID;
2532 internalvar_name (const struct internalvar *var)
2537 static struct internal_function *
2538 create_internal_function (const char *name,
2539 internal_function_fn handler, void *cookie)
2541 struct internal_function *ifn = XNEW (struct internal_function);
2543 ifn->name = xstrdup (name);
2544 ifn->handler = handler;
2545 ifn->cookie = cookie;
2550 value_internal_function_name (struct value *val)
2552 struct internal_function *ifn;
2555 gdb_assert (VALUE_LVAL (val) == lval_internalvar);
2556 result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
2557 gdb_assert (result);
2563 call_internal_function (struct gdbarch *gdbarch,
2564 const struct language_defn *language,
2565 struct value *func, int argc, struct value **argv)
2567 struct internal_function *ifn;
2570 gdb_assert (VALUE_LVAL (func) == lval_internalvar);
2571 result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
2572 gdb_assert (result);
2574 return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
2577 /* The 'function' command. This does nothing -- it is just a
2578 placeholder to let "help function NAME" work. This is also used as
2579 the implementation of the sub-command that is created when
2580 registering an internal function. */
2582 function_command (char *command, int from_tty)
2587 /* Clean up if an internal function's command is destroyed. */
2589 function_destroyer (struct cmd_list_element *self, void *ignore)
2591 xfree ((char *) self->name);
2592 xfree ((char *) self->doc);
2595 /* Add a new internal function. NAME is the name of the function; DOC
2596 is a documentation string describing the function. HANDLER is
2597 called when the function is invoked. COOKIE is an arbitrary
2598 pointer which is passed to HANDLER and is intended for "user
2601 add_internal_function (const char *name, const char *doc,
2602 internal_function_fn handler, void *cookie)
2604 struct cmd_list_element *cmd;
2605 struct internal_function *ifn;
2606 struct internalvar *var = lookup_internalvar (name);
2608 ifn = create_internal_function (name, handler, cookie);
2609 set_internalvar_function (var, ifn);
2611 cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
2613 cmd->destroyer = function_destroyer;
2616 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2617 prevent cycles / duplicates. */
2620 preserve_one_value (struct value *value, struct objfile *objfile,
2621 htab_t copied_types)
2623 if (TYPE_OBJFILE (value->type) == objfile)
2624 value->type = copy_type_recursive (objfile, value->type, copied_types);
2626 if (TYPE_OBJFILE (value->enclosing_type) == objfile)
2627 value->enclosing_type = copy_type_recursive (objfile,
2628 value->enclosing_type,
2632 /* Likewise for internal variable VAR. */
2635 preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
2636 htab_t copied_types)
2640 case INTERNALVAR_INTEGER:
2641 if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
2643 = copy_type_recursive (objfile, var->u.integer.type, copied_types);
2646 case INTERNALVAR_VALUE:
2647 preserve_one_value (var->u.value, objfile, copied_types);
2652 /* Update the internal variables and value history when OBJFILE is
2653 discarded; we must copy the types out of the objfile. New global types
2654 will be created for every convenience variable which currently points to
2655 this objfile's types, and the convenience variables will be adjusted to
2656 use the new global types. */
2659 preserve_values (struct objfile *objfile)
2661 htab_t copied_types;
2662 struct value_history_chunk *cur;
2663 struct internalvar *var;
2666 /* Create the hash table. We allocate on the objfile's obstack, since
2667 it is soon to be deleted. */
2668 copied_types = create_copied_types_hash (objfile);
2670 for (cur = value_history_chain; cur; cur = cur->next)
2671 for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
2673 preserve_one_value (cur->values[i], objfile, copied_types);
2675 for (var = internalvars; var; var = var->next)
2676 preserve_one_internalvar (var, objfile, copied_types);
2678 preserve_ext_lang_values (objfile, copied_types);
2680 htab_delete (copied_types);
2684 show_convenience (char *ignore, int from_tty)
2686 struct gdbarch *gdbarch = get_current_arch ();
2687 struct internalvar *var;
2689 struct value_print_options opts;
2691 get_user_print_options (&opts);
2692 for (var = internalvars; var; var = var->next)
2699 printf_filtered (("$%s = "), var->name);
2705 val = value_of_internalvar (gdbarch, var);
2706 value_print (val, gdb_stdout, &opts);
2708 CATCH (ex, RETURN_MASK_ERROR)
2710 fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
2714 printf_filtered (("\n"));
2718 /* This text does not mention convenience functions on purpose.
2719 The user can't create them except via Python, and if Python support
2720 is installed this message will never be printed ($_streq will
2722 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2723 "Convenience variables have "
2724 "names starting with \"$\";\n"
2725 "use \"set\" as in \"set "
2726 "$foo = 5\" to define them.\n"));
2730 /* Return the TYPE_CODE_XMETHOD value corresponding to WORKER. */
2733 value_of_xmethod (struct xmethod_worker *worker)
2735 if (worker->value == NULL)
2739 v = allocate_value (builtin_type (target_gdbarch ())->xmethod);
2740 v->lval = lval_xcallable;
2741 v->location.xm_worker = worker;
2746 return worker->value;
2749 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2752 result_type_of_xmethod (struct value *method, int argc, struct value **argv)
2754 gdb_assert (TYPE_CODE (value_type (method)) == TYPE_CODE_XMETHOD
2755 && method->lval == lval_xcallable && argc > 0);
2757 return get_xmethod_result_type (method->location.xm_worker,
2758 argv[0], argv + 1, argc - 1);
2761 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2764 call_xmethod (struct value *method, int argc, struct value **argv)
2766 gdb_assert (TYPE_CODE (value_type (method)) == TYPE_CODE_XMETHOD
2767 && method->lval == lval_xcallable && argc > 0);
2769 return invoke_xmethod (method->location.xm_worker,
2770 argv[0], argv + 1, argc - 1);
2773 /* Extract a value as a C number (either long or double).
2774 Knows how to convert fixed values to double, or
2775 floating values to long.
2776 Does not deallocate the value. */
2779 value_as_long (struct value *val)
2781 /* This coerces arrays and functions, which is necessary (e.g.
2782 in disassemble_command). It also dereferences references, which
2783 I suspect is the most logical thing to do. */
2784 val = coerce_array (val);
2785 return unpack_long (value_type (val), value_contents (val));
2789 value_as_double (struct value *val)
2794 foo = unpack_double (value_type (val), value_contents (val), &inv);
2796 error (_("Invalid floating value found in program."));
2800 /* Extract a value as a C pointer. Does not deallocate the value.
2801 Note that val's type may not actually be a pointer; value_as_long
2802 handles all the cases. */
2804 value_as_address (struct value *val)
2806 struct gdbarch *gdbarch = get_type_arch (value_type (val));
2808 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2809 whether we want this to be true eventually. */
2811 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2812 non-address (e.g. argument to "signal", "info break", etc.), or
2813 for pointers to char, in which the low bits *are* significant. */
2814 return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
2817 /* There are several targets (IA-64, PowerPC, and others) which
2818 don't represent pointers to functions as simply the address of
2819 the function's entry point. For example, on the IA-64, a
2820 function pointer points to a two-word descriptor, generated by
2821 the linker, which contains the function's entry point, and the
2822 value the IA-64 "global pointer" register should have --- to
2823 support position-independent code. The linker generates
2824 descriptors only for those functions whose addresses are taken.
2826 On such targets, it's difficult for GDB to convert an arbitrary
2827 function address into a function pointer; it has to either find
2828 an existing descriptor for that function, or call malloc and
2829 build its own. On some targets, it is impossible for GDB to
2830 build a descriptor at all: the descriptor must contain a jump
2831 instruction; data memory cannot be executed; and code memory
2834 Upon entry to this function, if VAL is a value of type `function'
2835 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2836 value_address (val) is the address of the function. This is what
2837 you'll get if you evaluate an expression like `main'. The call
2838 to COERCE_ARRAY below actually does all the usual unary
2839 conversions, which includes converting values of type `function'
2840 to `pointer to function'. This is the challenging conversion
2841 discussed above. Then, `unpack_long' will convert that pointer
2842 back into an address.
2844 So, suppose the user types `disassemble foo' on an architecture
2845 with a strange function pointer representation, on which GDB
2846 cannot build its own descriptors, and suppose further that `foo'
2847 has no linker-built descriptor. The address->pointer conversion
2848 will signal an error and prevent the command from running, even
2849 though the next step would have been to convert the pointer
2850 directly back into the same address.
2852 The following shortcut avoids this whole mess. If VAL is a
2853 function, just return its address directly. */
2854 if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
2855 || TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
2856 return value_address (val);
2858 val = coerce_array (val);
2860 /* Some architectures (e.g. Harvard), map instruction and data
2861 addresses onto a single large unified address space. For
2862 instance: An architecture may consider a large integer in the
2863 range 0x10000000 .. 0x1000ffff to already represent a data
2864 addresses (hence not need a pointer to address conversion) while
2865 a small integer would still need to be converted integer to
2866 pointer to address. Just assume such architectures handle all
2867 integer conversions in a single function. */
2871 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2872 must admonish GDB hackers to make sure its behavior matches the
2873 compiler's, whenever possible.
2875 In general, I think GDB should evaluate expressions the same way
2876 the compiler does. When the user copies an expression out of
2877 their source code and hands it to a `print' command, they should
2878 get the same value the compiler would have computed. Any
2879 deviation from this rule can cause major confusion and annoyance,
2880 and needs to be justified carefully. In other words, GDB doesn't
2881 really have the freedom to do these conversions in clever and
2884 AndrewC pointed out that users aren't complaining about how GDB
2885 casts integers to pointers; they are complaining that they can't
2886 take an address from a disassembly listing and give it to `x/i'.
2887 This is certainly important.
2889 Adding an architecture method like integer_to_address() certainly
2890 makes it possible for GDB to "get it right" in all circumstances
2891 --- the target has complete control over how things get done, so
2892 people can Do The Right Thing for their target without breaking
2893 anyone else. The standard doesn't specify how integers get
2894 converted to pointers; usually, the ABI doesn't either, but
2895 ABI-specific code is a more reasonable place to handle it. */
2897 if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
2898 && TYPE_CODE (value_type (val)) != TYPE_CODE_REF
2899 && gdbarch_integer_to_address_p (gdbarch))
2900 return gdbarch_integer_to_address (gdbarch, value_type (val),
2901 value_contents (val));
2903 return unpack_long (value_type (val), value_contents (val));
2907 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2908 as a long, or as a double, assuming the raw data is described
2909 by type TYPE. Knows how to convert different sizes of values
2910 and can convert between fixed and floating point. We don't assume
2911 any alignment for the raw data. Return value is in host byte order.
2913 If you want functions and arrays to be coerced to pointers, and
2914 references to be dereferenced, call value_as_long() instead.
2916 C++: It is assumed that the front-end has taken care of
2917 all matters concerning pointers to members. A pointer
2918 to member which reaches here is considered to be equivalent
2919 to an INT (or some size). After all, it is only an offset. */
2922 unpack_long (struct type *type, const gdb_byte *valaddr)
2924 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2925 enum type_code code = TYPE_CODE (type);
2926 int len = TYPE_LENGTH (type);
2927 int nosign = TYPE_UNSIGNED (type);
2931 case TYPE_CODE_TYPEDEF:
2932 return unpack_long (check_typedef (type), valaddr);
2933 case TYPE_CODE_ENUM:
2934 case TYPE_CODE_FLAGS:
2935 case TYPE_CODE_BOOL:
2937 case TYPE_CODE_CHAR:
2938 case TYPE_CODE_RANGE:
2939 case TYPE_CODE_MEMBERPTR:
2941 return extract_unsigned_integer (valaddr, len, byte_order);
2943 return extract_signed_integer (valaddr, len, byte_order);
2946 return (LONGEST) extract_typed_floating (valaddr, type);
2948 case TYPE_CODE_DECFLOAT:
2949 /* libdecnumber has a function to convert from decimal to integer, but
2950 it doesn't work when the decimal number has a fractional part. */
2951 return (LONGEST) decimal_to_doublest (valaddr, len, byte_order);
2955 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2956 whether we want this to be true eventually. */
2957 return extract_typed_address (valaddr, type);
2960 error (_("Value can't be converted to integer."));
2962 return 0; /* Placate lint. */
2965 /* Return a double value from the specified type and address.
2966 INVP points to an int which is set to 0 for valid value,
2967 1 for invalid value (bad float format). In either case,
2968 the returned double is OK to use. Argument is in target
2969 format, result is in host format. */
2972 unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
2974 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
2975 enum type_code code;
2979 *invp = 0; /* Assume valid. */
2980 type = check_typedef (type);
2981 code = TYPE_CODE (type);
2982 len = TYPE_LENGTH (type);
2983 nosign = TYPE_UNSIGNED (type);
2984 if (code == TYPE_CODE_FLT)
2986 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2987 floating-point value was valid (using the macro
2988 INVALID_FLOAT). That test/macro have been removed.
2990 It turns out that only the VAX defined this macro and then
2991 only in a non-portable way. Fixing the portability problem
2992 wouldn't help since the VAX floating-point code is also badly
2993 bit-rotten. The target needs to add definitions for the
2994 methods gdbarch_float_format and gdbarch_double_format - these
2995 exactly describe the target floating-point format. The
2996 problem here is that the corresponding floatformat_vax_f and
2997 floatformat_vax_d values these methods should be set to are
2998 also not defined either. Oops!
3000 Hopefully someone will add both the missing floatformat
3001 definitions and the new cases for floatformat_is_valid (). */
3003 if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
3009 return extract_typed_floating (valaddr, type);
3011 else if (code == TYPE_CODE_DECFLOAT)
3012 return decimal_to_doublest (valaddr, len, byte_order);
3015 /* Unsigned -- be sure we compensate for signed LONGEST. */
3016 return (ULONGEST) unpack_long (type, valaddr);
3020 /* Signed -- we are OK with unpack_long. */
3021 return unpack_long (type, valaddr);
3025 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
3026 as a CORE_ADDR, assuming the raw data is described by type TYPE.
3027 We don't assume any alignment for the raw data. Return value is in
3030 If you want functions and arrays to be coerced to pointers, and
3031 references to be dereferenced, call value_as_address() instead.
3033 C++: It is assumed that the front-end has taken care of
3034 all matters concerning pointers to members. A pointer
3035 to member which reaches here is considered to be equivalent
3036 to an INT (or some size). After all, it is only an offset. */
3039 unpack_pointer (struct type *type, const gdb_byte *valaddr)
3041 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
3042 whether we want this to be true eventually. */
3043 return unpack_long (type, valaddr);
3047 /* Get the value of the FIELDNO'th field (which must be static) of
3051 value_static_field (struct type *type, int fieldno)
3053 struct value *retval;
3055 switch (TYPE_FIELD_LOC_KIND (type, fieldno))
3057 case FIELD_LOC_KIND_PHYSADDR:
3058 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
3059 TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
3061 case FIELD_LOC_KIND_PHYSNAME:
3063 const char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
3064 /* TYPE_FIELD_NAME (type, fieldno); */
3065 struct block_symbol sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
3067 if (sym.symbol == NULL)
3069 /* With some compilers, e.g. HP aCC, static data members are
3070 reported as non-debuggable symbols. */
3071 struct bound_minimal_symbol msym
3072 = lookup_minimal_symbol (phys_name, NULL, NULL);
3075 return allocate_optimized_out_value (type);
3078 retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
3079 BMSYMBOL_VALUE_ADDRESS (msym));
3083 retval = value_of_variable (sym.symbol, sym.block);
3087 gdb_assert_not_reached ("unexpected field location kind");
3093 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
3094 You have to be careful here, since the size of the data area for the value
3095 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
3096 than the old enclosing type, you have to allocate more space for the
3100 set_value_enclosing_type (struct value *val, struct type *new_encl_type)
3102 if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
3104 check_type_length_before_alloc (new_encl_type);
3106 = (gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
3109 val->enclosing_type = new_encl_type;
3112 /* Given a value ARG1 (offset by OFFSET bytes)
3113 of a struct or union type ARG_TYPE,
3114 extract and return the value of one of its (non-static) fields.
3115 FIELDNO says which field. */
3118 value_primitive_field (struct value *arg1, LONGEST offset,
3119 int fieldno, struct type *arg_type)
3123 struct gdbarch *arch = get_value_arch (arg1);
3124 int unit_size = gdbarch_addressable_memory_unit_size (arch);
3126 arg_type = check_typedef (arg_type);
3127 type = TYPE_FIELD_TYPE (arg_type, fieldno);
3129 /* Call check_typedef on our type to make sure that, if TYPE
3130 is a TYPE_CODE_TYPEDEF, its length is set to the length
3131 of the target type instead of zero. However, we do not
3132 replace the typedef type by the target type, because we want
3133 to keep the typedef in order to be able to print the type
3134 description correctly. */
3135 check_typedef (type);
3137 if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
3139 /* Handle packed fields.
3141 Create a new value for the bitfield, with bitpos and bitsize
3142 set. If possible, arrange offset and bitpos so that we can
3143 do a single aligned read of the size of the containing type.
3144 Otherwise, adjust offset to the byte containing the first
3145 bit. Assume that the address, offset, and embedded offset
3146 are sufficiently aligned. */
3148 LONGEST bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
3149 LONGEST container_bitsize = TYPE_LENGTH (type) * 8;
3151 v = allocate_value_lazy (type);
3152 v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
3153 if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
3154 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
3155 v->bitpos = bitpos % container_bitsize;
3157 v->bitpos = bitpos % 8;
3158 v->offset = (value_embedded_offset (arg1)
3160 + (bitpos - v->bitpos) / 8);
3161 set_value_parent (v, arg1);
3162 if (!value_lazy (arg1))
3163 value_fetch_lazy (v);
3165 else if (fieldno < TYPE_N_BASECLASSES (arg_type))
3167 /* This field is actually a base subobject, so preserve the
3168 entire object's contents for later references to virtual
3172 /* Lazy register values with offsets are not supported. */
3173 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
3174 value_fetch_lazy (arg1);
3176 /* We special case virtual inheritance here because this
3177 requires access to the contents, which we would rather avoid
3178 for references to ordinary fields of unavailable values. */
3179 if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno))
3180 boffset = baseclass_offset (arg_type, fieldno,
3181 value_contents (arg1),
3182 value_embedded_offset (arg1),
3183 value_address (arg1),
3186 boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
3188 if (value_lazy (arg1))
3189 v = allocate_value_lazy (value_enclosing_type (arg1));
3192 v = allocate_value (value_enclosing_type (arg1));
3193 value_contents_copy_raw (v, 0, arg1, 0,
3194 TYPE_LENGTH (value_enclosing_type (arg1)));
3197 v->offset = value_offset (arg1);
3198 v->embedded_offset = offset + value_embedded_offset (arg1) + boffset;
3200 else if (NULL != TYPE_DATA_LOCATION (type))
3202 /* Field is a dynamic data member. */
3204 gdb_assert (0 == offset);
3205 /* We expect an already resolved data location. */
3206 gdb_assert (PROP_CONST == TYPE_DATA_LOCATION_KIND (type));
3207 /* For dynamic data types defer memory allocation
3208 until we actual access the value. */
3209 v = allocate_value_lazy (type);
3213 /* Plain old data member */
3214 offset += (TYPE_FIELD_BITPOS (arg_type, fieldno)
3215 / (HOST_CHAR_BIT * unit_size));
3217 /* Lazy register values with offsets are not supported. */
3218 if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
3219 value_fetch_lazy (arg1);
3221 if (value_lazy (arg1))
3222 v = allocate_value_lazy (type);
3225 v = allocate_value (type);
3226 value_contents_copy_raw (v, value_embedded_offset (v),
3227 arg1, value_embedded_offset (arg1) + offset,
3228 type_length_units (type));
3230 v->offset = (value_offset (arg1) + offset
3231 + value_embedded_offset (arg1));
3233 set_value_component_location (v, arg1);
3234 VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
3235 VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
3239 /* Given a value ARG1 of a struct or union type,
3240 extract and return the value of one of its (non-static) fields.
3241 FIELDNO says which field. */
3244 value_field (struct value *arg1, int fieldno)
3246 return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
3249 /* Return a non-virtual function as a value.
3250 F is the list of member functions which contains the desired method.
3251 J is an index into F which provides the desired method.
3253 We only use the symbol for its address, so be happy with either a
3254 full symbol or a minimal symbol. */
3257 value_fn_field (struct value **arg1p, struct fn_field *f,
3258 int j, struct type *type,
3262 struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
3263 const char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
3265 struct bound_minimal_symbol msym;
3267 sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0).symbol;
3270 memset (&msym, 0, sizeof (msym));
3274 gdb_assert (sym == NULL);
3275 msym = lookup_bound_minimal_symbol (physname);
3276 if (msym.minsym == NULL)
3280 v = allocate_value (ftype);
3283 set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
3287 /* The minimal symbol might point to a function descriptor;
3288 resolve it to the actual code address instead. */
3289 struct objfile *objfile = msym.objfile;
3290 struct gdbarch *gdbarch = get_objfile_arch (objfile);
3292 set_value_address (v,
3293 gdbarch_convert_from_func_ptr_addr
3294 (gdbarch, BMSYMBOL_VALUE_ADDRESS (msym), ¤t_target));
3299 if (type != value_type (*arg1p))
3300 *arg1p = value_ind (value_cast (lookup_pointer_type (type),
3301 value_addr (*arg1p)));
3303 /* Move the `this' pointer according to the offset.
3304 VALUE_OFFSET (*arg1p) += offset; */
3312 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3313 VALADDR, and store the result in *RESULT.
3314 The bitfield starts at BITPOS bits and contains BITSIZE bits.
3316 Extracting bits depends on endianness of the machine. Compute the
3317 number of least significant bits to discard. For big endian machines,
3318 we compute the total number of bits in the anonymous object, subtract
3319 off the bit count from the MSB of the object to the MSB of the
3320 bitfield, then the size of the bitfield, which leaves the LSB discard
3321 count. For little endian machines, the discard count is simply the
3322 number of bits from the LSB of the anonymous object to the LSB of the
3325 If the field is signed, we also do sign extension. */
3328 unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
3329 LONGEST bitpos, LONGEST bitsize)
3331 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
3336 LONGEST read_offset;
3338 /* Read the minimum number of bytes required; there may not be
3339 enough bytes to read an entire ULONGEST. */
3340 field_type = check_typedef (field_type);
3342 bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
3344 bytes_read = TYPE_LENGTH (field_type);
3346 read_offset = bitpos / 8;
3348 val = extract_unsigned_integer (valaddr + read_offset,
3349 bytes_read, byte_order);
3351 /* Extract bits. See comment above. */
3353 if (gdbarch_bits_big_endian (get_type_arch (field_type)))
3354 lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
3356 lsbcount = (bitpos % 8);
3359 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3360 If the field is signed, and is negative, then sign extend. */
3362 if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
3364 valmask = (((ULONGEST) 1) << bitsize) - 1;
3366 if (!TYPE_UNSIGNED (field_type))
3368 if (val & (valmask ^ (valmask >> 1)))
3378 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3379 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3380 ORIGINAL_VALUE, which must not be NULL. See
3381 unpack_value_bits_as_long for more details. */
3384 unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
3385 LONGEST embedded_offset, int fieldno,
3386 const struct value *val, LONGEST *result)
3388 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3389 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3390 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
3393 gdb_assert (val != NULL);
3395 bit_offset = embedded_offset * TARGET_CHAR_BIT + bitpos;
3396 if (value_bits_any_optimized_out (val, bit_offset, bitsize)
3397 || !value_bits_available (val, bit_offset, bitsize))
3400 *result = unpack_bits_as_long (field_type, valaddr + embedded_offset,
3405 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3406 object at VALADDR. See unpack_bits_as_long for more details. */
3409 unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
3411 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3412 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3413 struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
3415 return unpack_bits_as_long (field_type, valaddr, bitpos, bitsize);
3418 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3419 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3420 the contents in DEST_VAL, zero or sign extending if the type of
3421 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3422 VAL. If the VAL's contents required to extract the bitfield from
3423 are unavailable/optimized out, DEST_VAL is correspondingly
3424 marked unavailable/optimized out. */
3427 unpack_value_bitfield (struct value *dest_val,
3428 LONGEST bitpos, LONGEST bitsize,
3429 const gdb_byte *valaddr, LONGEST embedded_offset,
3430 const struct value *val)
3432 enum bfd_endian byte_order;
3435 struct type *field_type = value_type (dest_val);
3437 byte_order = gdbarch_byte_order (get_type_arch (field_type));
3439 /* First, unpack and sign extend the bitfield as if it was wholly
3440 valid. Optimized out/unavailable bits are read as zero, but
3441 that's OK, as they'll end up marked below. If the VAL is
3442 wholly-invalid we may have skipped allocating its contents,
3443 though. See allocate_optimized_out_value. */
3444 if (valaddr != NULL)
3448 num = unpack_bits_as_long (field_type, valaddr + embedded_offset,
3450 store_signed_integer (value_contents_raw (dest_val),
3451 TYPE_LENGTH (field_type), byte_order, num);
3454 /* Now copy the optimized out / unavailability ranges to the right
3456 src_bit_offset = embedded_offset * TARGET_CHAR_BIT + bitpos;
3457 if (byte_order == BFD_ENDIAN_BIG)
3458 dst_bit_offset = TYPE_LENGTH (field_type) * TARGET_CHAR_BIT - bitsize;
3461 value_ranges_copy_adjusted (dest_val, dst_bit_offset,
3462 val, src_bit_offset, bitsize);
3465 /* Return a new value with type TYPE, which is FIELDNO field of the
3466 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3467 of VAL. If the VAL's contents required to extract the bitfield
3468 from are unavailable/optimized out, the new value is
3469 correspondingly marked unavailable/optimized out. */
3472 value_field_bitfield (struct type *type, int fieldno,
3473 const gdb_byte *valaddr,
3474 LONGEST embedded_offset, const struct value *val)
3476 int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
3477 int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
3478 struct value *res_val = allocate_value (TYPE_FIELD_TYPE (type, fieldno));
3480 unpack_value_bitfield (res_val, bitpos, bitsize,
3481 valaddr, embedded_offset, val);
3486 /* Modify the value of a bitfield. ADDR points to a block of memory in
3487 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3488 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3489 indicate which bits (in target bit order) comprise the bitfield.
3490 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3491 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3494 modify_field (struct type *type, gdb_byte *addr,
3495 LONGEST fieldval, LONGEST bitpos, LONGEST bitsize)
3497 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
3499 ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
3502 /* Normalize BITPOS. */
3506 /* If a negative fieldval fits in the field in question, chop
3507 off the sign extension bits. */
3508 if ((~fieldval & ~(mask >> 1)) == 0)
3511 /* Warn if value is too big to fit in the field in question. */
3512 if (0 != (fieldval & ~mask))
3514 /* FIXME: would like to include fieldval in the message, but
3515 we don't have a sprintf_longest. */
3516 warning (_("Value does not fit in %s bits."), plongest (bitsize));
3518 /* Truncate it, otherwise adjoining fields may be corrupted. */
3522 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3523 false valgrind reports. */
3525 bytesize = (bitpos + bitsize + 7) / 8;
3526 oword = extract_unsigned_integer (addr, bytesize, byte_order);
3528 /* Shifting for bit field depends on endianness of the target machine. */
3529 if (gdbarch_bits_big_endian (get_type_arch (type)))
3530 bitpos = bytesize * 8 - bitpos - bitsize;
3532 oword &= ~(mask << bitpos);
3533 oword |= fieldval << bitpos;
3535 store_unsigned_integer (addr, bytesize, byte_order, oword);
3538 /* Pack NUM into BUF using a target format of TYPE. */
3541 pack_long (gdb_byte *buf, struct type *type, LONGEST num)
3543 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
3546 type = check_typedef (type);
3547 len = TYPE_LENGTH (type);
3549 switch (TYPE_CODE (type))
3552 case TYPE_CODE_CHAR:
3553 case TYPE_CODE_ENUM:
3554 case TYPE_CODE_FLAGS:
3555 case TYPE_CODE_BOOL:
3556 case TYPE_CODE_RANGE:
3557 case TYPE_CODE_MEMBERPTR:
3558 store_signed_integer (buf, len, byte_order, num);
3563 store_typed_address (buf, type, (CORE_ADDR) num);
3567 error (_("Unexpected type (%d) encountered for integer constant."),
3573 /* Pack NUM into BUF using a target format of TYPE. */
3576 pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
3579 enum bfd_endian byte_order;
3581 type = check_typedef (type);
3582 len = TYPE_LENGTH (type);
3583 byte_order = gdbarch_byte_order (get_type_arch (type));
3585 switch (TYPE_CODE (type))
3588 case TYPE_CODE_CHAR:
3589 case TYPE_CODE_ENUM:
3590 case TYPE_CODE_FLAGS:
3591 case TYPE_CODE_BOOL:
3592 case TYPE_CODE_RANGE:
3593 case TYPE_CODE_MEMBERPTR:
3594 store_unsigned_integer (buf, len, byte_order, num);
3599 store_typed_address (buf, type, (CORE_ADDR) num);
3603 error (_("Unexpected type (%d) encountered "
3604 "for unsigned integer constant."),
3610 /* Convert C numbers into newly allocated values. */
3613 value_from_longest (struct type *type, LONGEST num)
3615 struct value *val = allocate_value (type);
3617 pack_long (value_contents_raw (val), type, num);
3622 /* Convert C unsigned numbers into newly allocated values. */
3625 value_from_ulongest (struct type *type, ULONGEST num)
3627 struct value *val = allocate_value (type);
3629 pack_unsigned_long (value_contents_raw (val), type, num);
3635 /* Create a value representing a pointer of type TYPE to the address
3639 value_from_pointer (struct type *type, CORE_ADDR addr)
3641 struct value *val = allocate_value (type);
3643 store_typed_address (value_contents_raw (val),
3644 check_typedef (type), addr);
3649 /* Create a value of type TYPE whose contents come from VALADDR, if it
3650 is non-null, and whose memory address (in the inferior) is
3651 ADDRESS. The type of the created value may differ from the passed
3652 type TYPE. Make sure to retrieve values new type after this call.
3653 Note that TYPE is not passed through resolve_dynamic_type; this is
3654 a special API intended for use only by Ada. */
3657 value_from_contents_and_address_unresolved (struct type *type,
3658 const gdb_byte *valaddr,
3663 if (valaddr == NULL)
3664 v = allocate_value_lazy (type);
3666 v = value_from_contents (type, valaddr);
3667 set_value_address (v, address);
3668 VALUE_LVAL (v) = lval_memory;
3672 /* Create a value of type TYPE whose contents come from VALADDR, if it
3673 is non-null, and whose memory address (in the inferior) is
3674 ADDRESS. The type of the created value may differ from the passed
3675 type TYPE. Make sure to retrieve values new type after this call. */
3678 value_from_contents_and_address (struct type *type,
3679 const gdb_byte *valaddr,
3682 struct type *resolved_type = resolve_dynamic_type (type, valaddr, address);
3683 struct type *resolved_type_no_typedef = check_typedef (resolved_type);
3686 if (valaddr == NULL)
3687 v = allocate_value_lazy (resolved_type);
3689 v = value_from_contents (resolved_type, valaddr);
3690 if (TYPE_DATA_LOCATION (resolved_type_no_typedef) != NULL
3691 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef) == PROP_CONST)
3692 address = TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef);
3693 set_value_address (v, address);
3694 VALUE_LVAL (v) = lval_memory;
3698 /* Create a value of type TYPE holding the contents CONTENTS.
3699 The new value is `not_lval'. */
3702 value_from_contents (struct type *type, const gdb_byte *contents)
3704 struct value *result;
3706 result = allocate_value (type);
3707 memcpy (value_contents_raw (result), contents, TYPE_LENGTH (type));
3712 value_from_double (struct type *type, DOUBLEST num)
3714 struct value *val = allocate_value (type);
3715 struct type *base_type = check_typedef (type);
3716 enum type_code code = TYPE_CODE (base_type);
3718 if (code == TYPE_CODE_FLT)
3720 store_typed_floating (value_contents_raw (val), base_type, num);
3723 error (_("Unexpected type encountered for floating constant."));
3729 value_from_decfloat (struct type *type, const gdb_byte *dec)
3731 struct value *val = allocate_value (type);
3733 memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
3737 /* Extract a value from the history file. Input will be of the form
3738 $digits or $$digits. See block comment above 'write_dollar_variable'
3742 value_from_history_ref (const char *h, const char **endp)
3754 /* Find length of numeral string. */
3755 for (; isdigit (h[len]); len++)
3758 /* Make sure numeral string is not part of an identifier. */
3759 if (h[len] == '_' || isalpha (h[len]))
3762 /* Now collect the index value. */
3767 /* For some bizarre reason, "$$" is equivalent to "$$1",
3768 rather than to "$$0" as it ought to be! */
3776 index = -strtol (&h[2], &local_end, 10);
3784 /* "$" is equivalent to "$0". */
3792 index = strtol (&h[1], &local_end, 10);
3797 return access_value_history (index);
3801 coerce_ref_if_computed (const struct value *arg)
3803 const struct lval_funcs *funcs;
3805 if (TYPE_CODE (check_typedef (value_type (arg))) != TYPE_CODE_REF)
3808 if (value_lval_const (arg) != lval_computed)
3811 funcs = value_computed_funcs (arg);
3812 if (funcs->coerce_ref == NULL)
3815 return funcs->coerce_ref (arg);
3818 /* Look at value.h for description. */
3821 readjust_indirect_value_type (struct value *value, struct type *enc_type,
3822 const struct type *original_type,
3823 const struct value *original_value)
3825 /* Re-adjust type. */
3826 deprecated_set_value_type (value, TYPE_TARGET_TYPE (original_type));
3828 /* Add embedding info. */
3829 set_value_enclosing_type (value, enc_type);
3830 set_value_embedded_offset (value, value_pointed_to_offset (original_value));
3832 /* We may be pointing to an object of some derived type. */
3833 return value_full_object (value, NULL, 0, 0, 0);
3837 coerce_ref (struct value *arg)
3839 struct type *value_type_arg_tmp = check_typedef (value_type (arg));
3840 struct value *retval;
3841 struct type *enc_type;
3843 retval = coerce_ref_if_computed (arg);
3847 if (TYPE_CODE (value_type_arg_tmp) != TYPE_CODE_REF)
3850 enc_type = check_typedef (value_enclosing_type (arg));
3851 enc_type = TYPE_TARGET_TYPE (enc_type);
3853 retval = value_at_lazy (enc_type,
3854 unpack_pointer (value_type (arg),
3855 value_contents (arg)));
3856 enc_type = value_type (retval);
3857 return readjust_indirect_value_type (retval, enc_type,
3858 value_type_arg_tmp, arg);
3862 coerce_array (struct value *arg)
3866 arg = coerce_ref (arg);
3867 type = check_typedef (value_type (arg));
3869 switch (TYPE_CODE (type))
3871 case TYPE_CODE_ARRAY:
3872 if (!TYPE_VECTOR (type) && current_language->c_style_arrays)
3873 arg = value_coerce_array (arg);
3875 case TYPE_CODE_FUNC:
3876 arg = value_coerce_function (arg);
3883 /* Return the return value convention that will be used for the
3886 enum return_value_convention
3887 struct_return_convention (struct gdbarch *gdbarch,
3888 struct value *function, struct type *value_type)
3890 enum type_code code = TYPE_CODE (value_type);
3892 if (code == TYPE_CODE_ERROR)
3893 error (_("Function return type unknown."));
3895 /* Probe the architecture for the return-value convention. */
3896 return gdbarch_return_value (gdbarch, function, value_type,
3900 /* Return true if the function returning the specified type is using
3901 the convention of returning structures in memory (passing in the
3902 address as a hidden first parameter). */
3905 using_struct_return (struct gdbarch *gdbarch,
3906 struct value *function, struct type *value_type)
3908 if (TYPE_CODE (value_type) == TYPE_CODE_VOID)
3909 /* A void return value is never in memory. See also corresponding
3910 code in "print_return_value". */
3913 return (struct_return_convention (gdbarch, function, value_type)
3914 != RETURN_VALUE_REGISTER_CONVENTION);
3917 /* Set the initialized field in a value struct. */
3920 set_value_initialized (struct value *val, int status)
3922 val->initialized = status;
3925 /* Return the initialized field in a value struct. */
3928 value_initialized (const struct value *val)
3930 return val->initialized;
3933 /* Load the actual content of a lazy value. Fetch the data from the
3934 user's process and clear the lazy flag to indicate that the data in
3935 the buffer is valid.
3937 If the value is zero-length, we avoid calling read_memory, which
3938 would abort. We mark the value as fetched anyway -- all 0 bytes of
3942 value_fetch_lazy (struct value *val)
3944 gdb_assert (value_lazy (val));
3945 allocate_value_contents (val);
3946 /* A value is either lazy, or fully fetched. The
3947 availability/validity is only established as we try to fetch a
3949 gdb_assert (VEC_empty (range_s, val->optimized_out));
3950 gdb_assert (VEC_empty (range_s, val->unavailable));
3951 if (value_bitsize (val))
3953 /* To read a lazy bitfield, read the entire enclosing value. This
3954 prevents reading the same block of (possibly volatile) memory once
3955 per bitfield. It would be even better to read only the containing
3956 word, but we have no way to record that just specific bits of a
3957 value have been fetched. */
3958 struct type *type = check_typedef (value_type (val));
3959 struct value *parent = value_parent (val);
3961 if (value_lazy (parent))
3962 value_fetch_lazy (parent);
3964 unpack_value_bitfield (val,
3965 value_bitpos (val), value_bitsize (val),
3966 value_contents_for_printing (parent),
3967 value_offset (val), parent);
3969 else if (VALUE_LVAL (val) == lval_memory)
3971 CORE_ADDR addr = value_address (val);
3972 struct type *type = check_typedef (value_enclosing_type (val));
3974 if (TYPE_LENGTH (type))
3975 read_value_memory (val, 0, value_stack (val),
3976 addr, value_contents_all_raw (val),
3977 type_length_units (type));
3979 else if (VALUE_LVAL (val) == lval_register)
3981 struct frame_info *frame;
3983 struct type *type = check_typedef (value_type (val));
3984 struct value *new_val = val, *mark = value_mark ();
3986 /* Offsets are not supported here; lazy register values must
3987 refer to the entire register. */
3988 gdb_assert (value_offset (val) == 0);
3990 while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val))
3992 struct frame_id frame_id = VALUE_FRAME_ID (new_val);
3994 frame = frame_find_by_id (frame_id);
3995 regnum = VALUE_REGNUM (new_val);
3997 gdb_assert (frame != NULL);
3999 /* Convertible register routines are used for multi-register
4000 values and for interpretation in different types
4001 (e.g. float or int from a double register). Lazy
4002 register values should have the register's natural type,
4003 so they do not apply. */
4004 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame),
4007 new_val = get_frame_register_value (frame, regnum);
4009 /* If we get another lazy lval_register value, it means the
4010 register is found by reading it from the next frame.
4011 get_frame_register_value should never return a value with
4012 the frame id pointing to FRAME. If it does, it means we
4013 either have two consecutive frames with the same frame id
4014 in the frame chain, or some code is trying to unwind
4015 behind get_prev_frame's back (e.g., a frame unwind
4016 sniffer trying to unwind), bypassing its validations. In
4017 any case, it should always be an internal error to end up
4018 in this situation. */
4019 if (VALUE_LVAL (new_val) == lval_register
4020 && value_lazy (new_val)
4021 && frame_id_eq (VALUE_FRAME_ID (new_val), frame_id))
4022 internal_error (__FILE__, __LINE__,
4023 _("infinite loop while fetching a register"));
4026 /* If it's still lazy (for instance, a saved register on the
4027 stack), fetch it. */
4028 if (value_lazy (new_val))
4029 value_fetch_lazy (new_val);
4031 /* Copy the contents and the unavailability/optimized-out
4032 meta-data from NEW_VAL to VAL. */
4033 set_value_lazy (val, 0);
4034 value_contents_copy (val, value_embedded_offset (val),
4035 new_val, value_embedded_offset (new_val),
4036 type_length_units (type));
4040 struct gdbarch *gdbarch;
4041 frame = frame_find_by_id (VALUE_FRAME_ID (val));
4042 regnum = VALUE_REGNUM (val);
4043 gdbarch = get_frame_arch (frame);
4045 fprintf_unfiltered (gdb_stdlog,
4046 "{ value_fetch_lazy "
4047 "(frame=%d,regnum=%d(%s),...) ",
4048 frame_relative_level (frame), regnum,
4049 user_reg_map_regnum_to_name (gdbarch, regnum));
4051 fprintf_unfiltered (gdb_stdlog, "->");
4052 if (value_optimized_out (new_val))
4054 fprintf_unfiltered (gdb_stdlog, " ");
4055 val_print_optimized_out (new_val, gdb_stdlog);
4060 const gdb_byte *buf = value_contents (new_val);
4062 if (VALUE_LVAL (new_val) == lval_register)
4063 fprintf_unfiltered (gdb_stdlog, " register=%d",
4064 VALUE_REGNUM (new_val));
4065 else if (VALUE_LVAL (new_val) == lval_memory)
4066 fprintf_unfiltered (gdb_stdlog, " address=%s",
4068 value_address (new_val)));
4070 fprintf_unfiltered (gdb_stdlog, " computed");
4072 fprintf_unfiltered (gdb_stdlog, " bytes=");
4073 fprintf_unfiltered (gdb_stdlog, "[");
4074 for (i = 0; i < register_size (gdbarch, regnum); i++)
4075 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
4076 fprintf_unfiltered (gdb_stdlog, "]");
4079 fprintf_unfiltered (gdb_stdlog, " }\n");
4082 /* Dispose of the intermediate values. This prevents
4083 watchpoints from trying to watch the saved frame pointer. */
4084 value_free_to_mark (mark);
4086 else if (VALUE_LVAL (val) == lval_computed
4087 && value_computed_funcs (val)->read != NULL)
4088 value_computed_funcs (val)->read (val);
4090 internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));
4092 set_value_lazy (val, 0);
4095 /* Implementation of the convenience function $_isvoid. */
4097 static struct value *
4098 isvoid_internal_fn (struct gdbarch *gdbarch,
4099 const struct language_defn *language,
4100 void *cookie, int argc, struct value **argv)
4105 error (_("You must provide one argument for $_isvoid."));
4107 ret = TYPE_CODE (value_type (argv[0])) == TYPE_CODE_VOID;
4109 return value_from_longest (builtin_type (gdbarch)->builtin_int, ret);
4113 _initialize_values (void)
4115 add_cmd ("convenience", no_class, show_convenience, _("\
4116 Debugger convenience (\"$foo\") variables and functions.\n\
4117 Convenience variables are created when you assign them values;\n\
4118 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
4120 A few convenience variables are given values automatically:\n\
4121 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
4122 \"$__\" holds the contents of the last address examined with \"x\"."
4125 Convenience functions are defined via the Python API."
4128 add_alias_cmd ("conv", "convenience", no_class, 1, &showlist);
4130 add_cmd ("values", no_set_class, show_values, _("\
4131 Elements of value history around item number IDX (or last ten)."),
4134 add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
4135 Initialize a convenience variable if necessary.\n\
4136 init-if-undefined VARIABLE = EXPRESSION\n\
4137 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
4138 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
4139 VARIABLE is already initialized."));
4141 add_prefix_cmd ("function", no_class, function_command, _("\
4142 Placeholder command for showing help on convenience functions."),
4143 &functionlist, "function ", 0, &cmdlist);
4145 add_internal_function ("_isvoid", _("\
4146 Check whether an expression is void.\n\
4147 Usage: $_isvoid (expression)\n\
4148 Return 1 if the expression is void, zero otherwise."),
4149 isvoid_internal_fn, NULL);
4151 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
4152 class_support, &max_value_size, _("\
4153 Set maximum sized value gdb will load from the inferior."), _("\
4154 Show maximum sized value gdb will load from the inferior."), _("\
4155 Use this to control the maximum size, in bytes, of a value that gdb\n\
4156 will load from the inferior. Setting this value to 'unlimited'\n\
4157 disables checking.\n\
4158 Setting this does not invalidate already allocated values, it only\n\
4159 prevents future values, larger than this size, from being allocated."),
4161 show_max_value_size,
4162 &setlist, &showlist);