1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2018 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"
33 #include "target-float.h"
36 #include "cli/cli-decode.h"
37 #include "extension.h"
39 #include "tracepoint.h"
41 #include "user-regs.h"
43 #include "completer.h"
45 /* Definition of a user function. */
46 struct internal_function
48 /* The name of the function. It is a bit odd to have this in the
49 function itself -- the user might use a differently-named
50 convenience variable to hold the function. */
54 internal_function_fn handler
;
56 /* User data for the handler. */
60 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
64 /* Lowest offset in the range. */
67 /* Length of the range. */
70 /* Returns true if THIS is strictly less than OTHER, useful for
71 searching. We keep ranges sorted by offset and coalesce
72 overlapping and contiguous ranges, so this just compares the
75 bool operator< (const range
&other
) const
77 return offset
< other
.offset
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (LONGEST offset1
, LONGEST len1
,
86 LONGEST offset2
, LONGEST len2
)
90 l
= std::max (offset1
, offset2
);
91 h
= std::min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if RANGES contains any range that overlaps [OFFSET,
99 ranges_contain (const std::vector
<range
> &ranges
, LONGEST offset
,
104 what
.offset
= offset
;
105 what
.length
= length
;
107 /* We keep ranges sorted by offset and coalesce overlapping and
108 contiguous ranges, so to check if a range list contains a given
109 range, we can do a binary search for the position the given range
110 would be inserted if we only considered the starting OFFSET of
111 ranges. We call that position I. Since we also have LENGTH to
112 care for (this is a range afterall), we need to check if the
113 _previous_ range overlaps the I range. E.g.,
117 |---| |---| |------| ... |--|
122 In the case above, the binary search would return `I=1', meaning,
123 this OFFSET should be inserted at position 1, and the current
124 position 1 should be pushed further (and before 2). But, `0'
127 Then we need to check if the I range overlaps the I range itself.
132 |---| |---| |-------| ... |--|
139 auto i
= std::lower_bound (ranges
.begin (), ranges
.end (), what
);
141 if (i
> ranges
.begin ())
143 const struct range
&bef
= *(i
- 1);
145 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
149 if (i
< ranges
.end ())
151 const struct range
&r
= *i
;
153 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
160 static struct cmd_list_element
*functionlist
;
162 /* Note that the fields in this structure are arranged to save a bit
167 explicit value (struct type
*type_
)
173 enclosing_type (type_
)
175 location
.address
= 0;
180 if (VALUE_LVAL (this) == lval_computed
)
182 const struct lval_funcs
*funcs
= location
.computed
.funcs
;
184 if (funcs
->free_closure
)
185 funcs
->free_closure (this);
187 else if (VALUE_LVAL (this) == lval_xcallable
)
188 delete location
.xm_worker
;
193 DISABLE_COPY_AND_ASSIGN (value
);
195 /* Type of value; either not an lval, or one of the various
196 different possible kinds of lval. */
197 enum lval_type lval
= not_lval
;
199 /* Is it modifiable? Only relevant if lval != not_lval. */
200 unsigned int modifiable
: 1;
202 /* If zero, contents of this value are in the contents field. If
203 nonzero, contents are in inferior. If the lval field is lval_memory,
204 the contents are in inferior memory at location.address plus offset.
205 The lval field may also be lval_register.
207 WARNING: This field is used by the code which handles watchpoints
208 (see breakpoint.c) to decide whether a particular value can be
209 watched by hardware watchpoints. If the lazy flag is set for
210 some member of a value chain, it is assumed that this member of
211 the chain doesn't need to be watched as part of watching the
212 value itself. This is how GDB avoids watching the entire struct
213 or array when the user wants to watch a single struct member or
214 array element. If you ever change the way lazy flag is set and
215 reset, be sure to consider this use as well! */
216 unsigned int lazy
: 1;
218 /* If value is a variable, is it initialized or not. */
219 unsigned int initialized
: 1;
221 /* If value is from the stack. If this is set, read_stack will be
222 used instead of read_memory to enable extra caching. */
223 unsigned int stack
: 1;
225 /* Location of value (if lval). */
228 /* If lval == lval_memory, this is the address in the inferior */
231 /*If lval == lval_register, the value is from a register. */
234 /* Register number. */
236 /* Frame ID of "next" frame to which a register value is relative.
237 If the register value is found relative to frame F, then the
238 frame id of F->next will be stored in next_frame_id. */
239 struct frame_id next_frame_id
;
242 /* Pointer to internal variable. */
243 struct internalvar
*internalvar
;
245 /* Pointer to xmethod worker. */
246 struct xmethod_worker
*xm_worker
;
248 /* If lval == lval_computed, this is a set of function pointers
249 to use to access and describe the value, and a closure pointer
253 /* Functions to call. */
254 const struct lval_funcs
*funcs
;
256 /* Closure for those functions to use. */
261 /* Describes offset of a value within lval of a structure in target
262 addressable memory units. Note also the member embedded_offset
266 /* Only used for bitfields; number of bits contained in them. */
269 /* Only used for bitfields; position of start of field. For
270 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
271 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
274 /* The number of references to this value. When a value is created,
275 the value chain holds a reference, so REFERENCE_COUNT is 1. If
276 release_value is called, this value is removed from the chain but
277 the caller of release_value now has a reference to this value.
278 The caller must arrange for a call to value_free later. */
279 int reference_count
= 1;
281 /* Only used for bitfields; the containing value. This allows a
282 single read from the target when displaying multiple
284 value_ref_ptr parent
;
286 /* Type of the value. */
289 /* If a value represents a C++ object, then the `type' field gives
290 the object's compile-time type. If the object actually belongs
291 to some class derived from `type', perhaps with other base
292 classes and additional members, then `type' is just a subobject
293 of the real thing, and the full object is probably larger than
294 `type' would suggest.
296 If `type' is a dynamic class (i.e. one with a vtable), then GDB
297 can actually determine the object's run-time type by looking at
298 the run-time type information in the vtable. When this
299 information is available, we may elect to read in the entire
300 object, for several reasons:
302 - When printing the value, the user would probably rather see the
303 full object, not just the limited portion apparent from the
306 - If `type' has virtual base classes, then even printing `type'
307 alone may require reaching outside the `type' portion of the
308 object to wherever the virtual base class has been stored.
310 When we store the entire object, `enclosing_type' is the run-time
311 type -- the complete object -- and `embedded_offset' is the
312 offset of `type' within that larger type, in target addressable memory
313 units. The value_contents() macro takes `embedded_offset' into account,
314 so most GDB code continues to see the `type' portion of the value, just
315 as the inferior would.
317 If `type' is a pointer to an object, then `enclosing_type' is a
318 pointer to the object's run-time type, and `pointed_to_offset' is
319 the offset in target addressable memory units from the full object
320 to the pointed-to object -- that is, the value `embedded_offset' would
321 have if we followed the pointer and fetched the complete object.
322 (I don't really see the point. Why not just determine the
323 run-time type when you indirect, and avoid the special case? The
324 contents don't matter until you indirect anyway.)
326 If we're not doing anything fancy, `enclosing_type' is equal to
327 `type', and `embedded_offset' is zero, so everything works
329 struct type
*enclosing_type
;
330 LONGEST embedded_offset
= 0;
331 LONGEST pointed_to_offset
= 0;
333 /* Actual contents of the value. Target byte-order. NULL or not
334 valid if lazy is nonzero. */
335 gdb_byte
*contents
= nullptr;
337 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
338 rather than available, since the common and default case is for a
339 value to be available. This is filled in at value read time.
340 The unavailable ranges are tracked in bits. Note that a contents
341 bit that has been optimized out doesn't really exist in the
342 program, so it can't be marked unavailable either. */
343 std::vector
<range
> unavailable
;
345 /* Likewise, but for optimized out contents (a chunk of the value of
346 a variable that does not actually exist in the program). If LVAL
347 is lval_register, this is a register ($pc, $sp, etc., never a
348 program variable) that has not been saved in the frame. Not
349 saved registers and optimized-out program variables values are
350 treated pretty much the same, except not-saved registers have a
351 different string representation and related error strings. */
352 std::vector
<range
> optimized_out
;
358 get_value_arch (const struct value
*value
)
360 return get_type_arch (value_type (value
));
364 value_bits_available (const struct value
*value
, LONGEST offset
, LONGEST length
)
366 gdb_assert (!value
->lazy
);
368 return !ranges_contain (value
->unavailable
, offset
, length
);
372 value_bytes_available (const struct value
*value
,
373 LONGEST offset
, LONGEST length
)
375 return value_bits_available (value
,
376 offset
* TARGET_CHAR_BIT
,
377 length
* TARGET_CHAR_BIT
);
381 value_bits_any_optimized_out (const struct value
*value
, int bit_offset
, int bit_length
)
383 gdb_assert (!value
->lazy
);
385 return ranges_contain (value
->optimized_out
, bit_offset
, bit_length
);
389 value_entirely_available (struct value
*value
)
391 /* We can only tell whether the whole value is available when we try
394 value_fetch_lazy (value
);
396 if (value
->unavailable
.empty ())
401 /* Returns true if VALUE is entirely covered by RANGES. If the value
402 is lazy, it'll be read now. Note that RANGE is a pointer to
403 pointer because reading the value might change *RANGE. */
406 value_entirely_covered_by_range_vector (struct value
*value
,
407 const std::vector
<range
> &ranges
)
409 /* We can only tell whether the whole value is optimized out /
410 unavailable when we try to read it. */
412 value_fetch_lazy (value
);
414 if (ranges
.size () == 1)
416 const struct range
&t
= ranges
[0];
419 && t
.length
== (TARGET_CHAR_BIT
420 * TYPE_LENGTH (value_enclosing_type (value
))))
428 value_entirely_unavailable (struct value
*value
)
430 return value_entirely_covered_by_range_vector (value
, value
->unavailable
);
434 value_entirely_optimized_out (struct value
*value
)
436 return value_entirely_covered_by_range_vector (value
, value
->optimized_out
);
439 /* Insert into the vector pointed to by VECTORP the bit range starting of
440 OFFSET bits, and extending for the next LENGTH bits. */
443 insert_into_bit_range_vector (std::vector
<range
> *vectorp
,
444 LONGEST offset
, LONGEST length
)
448 /* Insert the range sorted. If there's overlap or the new range
449 would be contiguous with an existing range, merge. */
451 newr
.offset
= offset
;
452 newr
.length
= length
;
454 /* Do a binary search for the position the given range would be
455 inserted if we only considered the starting OFFSET of ranges.
456 Call that position I. Since we also have LENGTH to care for
457 (this is a range afterall), we need to check if the _previous_
458 range overlaps the I range. E.g., calling R the new range:
460 #1 - overlaps with previous
464 |---| |---| |------| ... |--|
469 In the case #1 above, the binary search would return `I=1',
470 meaning, this OFFSET should be inserted at position 1, and the
471 current position 1 should be pushed further (and become 2). But,
472 note that `0' overlaps with R, so we want to merge them.
474 A similar consideration needs to be taken if the new range would
475 be contiguous with the previous range:
477 #2 - contiguous with previous
481 |--| |---| |------| ... |--|
486 If there's no overlap with the previous range, as in:
488 #3 - not overlapping and not contiguous
492 |--| |---| |------| ... |--|
499 #4 - R is the range with lowest offset
503 |--| |---| |------| ... |--|
508 ... we just push the new range to I.
510 All the 4 cases above need to consider that the new range may
511 also overlap several of the ranges that follow, or that R may be
512 contiguous with the following range, and merge. E.g.,
514 #5 - overlapping following ranges
517 |------------------------|
518 |--| |---| |------| ... |--|
527 |--| |---| |------| ... |--|
534 auto i
= std::lower_bound (vectorp
->begin (), vectorp
->end (), newr
);
535 if (i
> vectorp
->begin ())
537 struct range
&bef
= *(i
- 1);
539 if (ranges_overlap (bef
.offset
, bef
.length
, offset
, length
))
542 ULONGEST l
= std::min (bef
.offset
, offset
);
543 ULONGEST h
= std::max (bef
.offset
+ bef
.length
, offset
+ length
);
549 else if (offset
== bef
.offset
+ bef
.length
)
552 bef
.length
+= length
;
558 i
= vectorp
->insert (i
, newr
);
564 i
= vectorp
->insert (i
, newr
);
567 /* Check whether the ranges following the one we've just added or
568 touched can be folded in (#5 above). */
569 if (i
!= vectorp
->end () && i
+ 1 < vectorp
->end ())
574 /* Get the range we just touched. */
575 struct range
&t
= *i
;
579 for (; i
< vectorp
->end (); i
++)
581 struct range
&r
= *i
;
582 if (r
.offset
<= t
.offset
+ t
.length
)
586 l
= std::min (t
.offset
, r
.offset
);
587 h
= std::max (t
.offset
+ t
.length
, r
.offset
+ r
.length
);
596 /* If we couldn't merge this one, we won't be able to
597 merge following ones either, since the ranges are
598 always sorted by OFFSET. */
604 vectorp
->erase (next
, next
+ removed
);
609 mark_value_bits_unavailable (struct value
*value
,
610 LONGEST offset
, LONGEST length
)
612 insert_into_bit_range_vector (&value
->unavailable
, offset
, length
);
616 mark_value_bytes_unavailable (struct value
*value
,
617 LONGEST offset
, LONGEST length
)
619 mark_value_bits_unavailable (value
,
620 offset
* TARGET_CHAR_BIT
,
621 length
* TARGET_CHAR_BIT
);
624 /* Find the first range in RANGES that overlaps the range defined by
625 OFFSET and LENGTH, starting at element POS in the RANGES vector,
626 Returns the index into RANGES where such overlapping range was
627 found, or -1 if none was found. */
630 find_first_range_overlap (const std::vector
<range
> *ranges
, int pos
,
631 LONGEST offset
, LONGEST length
)
635 for (i
= pos
; i
< ranges
->size (); i
++)
637 const range
&r
= (*ranges
)[i
];
638 if (ranges_overlap (r
.offset
, r
.length
, offset
, length
))
645 /* Compare LENGTH_BITS of memory at PTR1 + OFFSET1_BITS with the memory at
646 PTR2 + OFFSET2_BITS. Return 0 if the memory is the same, otherwise
649 It must always be the case that:
650 OFFSET1_BITS % TARGET_CHAR_BIT == OFFSET2_BITS % TARGET_CHAR_BIT
652 It is assumed that memory can be accessed from:
653 PTR + (OFFSET_BITS / TARGET_CHAR_BIT)
655 PTR + ((OFFSET_BITS + LENGTH_BITS + TARGET_CHAR_BIT - 1)
656 / TARGET_CHAR_BIT) */
658 memcmp_with_bit_offsets (const gdb_byte
*ptr1
, size_t offset1_bits
,
659 const gdb_byte
*ptr2
, size_t offset2_bits
,
662 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
663 == offset2_bits
% TARGET_CHAR_BIT
);
665 if (offset1_bits
% TARGET_CHAR_BIT
!= 0)
668 gdb_byte mask
, b1
, b2
;
670 /* The offset from the base pointers PTR1 and PTR2 is not a complete
671 number of bytes. A number of bits up to either the next exact
672 byte boundary, or LENGTH_BITS (which ever is sooner) will be
674 bits
= TARGET_CHAR_BIT
- offset1_bits
% TARGET_CHAR_BIT
;
675 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
676 mask
= (1 << bits
) - 1;
678 if (length_bits
< bits
)
680 mask
&= ~(gdb_byte
) ((1 << (bits
- length_bits
)) - 1);
684 /* Now load the two bytes and mask off the bits we care about. */
685 b1
= *(ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
) & mask
;
686 b2
= *(ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
) & mask
;
691 /* Now update the length and offsets to take account of the bits
692 we've just compared. */
694 offset1_bits
+= bits
;
695 offset2_bits
+= bits
;
698 if (length_bits
% TARGET_CHAR_BIT
!= 0)
702 gdb_byte mask
, b1
, b2
;
704 /* The length is not an exact number of bytes. After the previous
705 IF.. block then the offsets are byte aligned, or the
706 length is zero (in which case this code is not reached). Compare
707 a number of bits at the end of the region, starting from an exact
709 bits
= length_bits
% TARGET_CHAR_BIT
;
710 o1
= offset1_bits
+ length_bits
- bits
;
711 o2
= offset2_bits
+ length_bits
- bits
;
713 gdb_assert (bits
< sizeof (mask
) * TARGET_CHAR_BIT
);
714 mask
= ((1 << bits
) - 1) << (TARGET_CHAR_BIT
- bits
);
716 gdb_assert (o1
% TARGET_CHAR_BIT
== 0);
717 gdb_assert (o2
% TARGET_CHAR_BIT
== 0);
719 b1
= *(ptr1
+ o1
/ TARGET_CHAR_BIT
) & mask
;
720 b2
= *(ptr2
+ o2
/ TARGET_CHAR_BIT
) & mask
;
730 /* We've now taken care of any stray "bits" at the start, or end of
731 the region to compare, the remainder can be covered with a simple
733 gdb_assert (offset1_bits
% TARGET_CHAR_BIT
== 0);
734 gdb_assert (offset2_bits
% TARGET_CHAR_BIT
== 0);
735 gdb_assert (length_bits
% TARGET_CHAR_BIT
== 0);
737 return memcmp (ptr1
+ offset1_bits
/ TARGET_CHAR_BIT
,
738 ptr2
+ offset2_bits
/ TARGET_CHAR_BIT
,
739 length_bits
/ TARGET_CHAR_BIT
);
742 /* Length is zero, regions match. */
746 /* Helper struct for find_first_range_overlap_and_match and
747 value_contents_bits_eq. Keep track of which slot of a given ranges
748 vector have we last looked at. */
750 struct ranges_and_idx
753 const std::vector
<range
> *ranges
;
755 /* The range we've last found in RANGES. Given ranges are sorted,
756 we can start the next lookup here. */
760 /* Helper function for value_contents_bits_eq. Compare LENGTH bits of
761 RP1's ranges starting at OFFSET1 bits with LENGTH bits of RP2's
762 ranges starting at OFFSET2 bits. Return true if the ranges match
763 and fill in *L and *H with the overlapping window relative to
764 (both) OFFSET1 or OFFSET2. */
767 find_first_range_overlap_and_match (struct ranges_and_idx
*rp1
,
768 struct ranges_and_idx
*rp2
,
769 LONGEST offset1
, LONGEST offset2
,
770 LONGEST length
, ULONGEST
*l
, ULONGEST
*h
)
772 rp1
->idx
= find_first_range_overlap (rp1
->ranges
, rp1
->idx
,
774 rp2
->idx
= find_first_range_overlap (rp2
->ranges
, rp2
->idx
,
777 if (rp1
->idx
== -1 && rp2
->idx
== -1)
783 else if (rp1
->idx
== -1 || rp2
->idx
== -1)
787 const range
*r1
, *r2
;
791 r1
= &(*rp1
->ranges
)[rp1
->idx
];
792 r2
= &(*rp2
->ranges
)[rp2
->idx
];
794 /* Get the unavailable windows intersected by the incoming
795 ranges. The first and last ranges that overlap the argument
796 range may be wider than said incoming arguments ranges. */
797 l1
= std::max (offset1
, r1
->offset
);
798 h1
= std::min (offset1
+ length
, r1
->offset
+ r1
->length
);
800 l2
= std::max (offset2
, r2
->offset
);
801 h2
= std::min (offset2
+ length
, offset2
+ r2
->length
);
803 /* Make them relative to the respective start offsets, so we can
804 compare them for equality. */
811 /* Different ranges, no match. */
812 if (l1
!= l2
|| h1
!= h2
)
821 /* Helper function for value_contents_eq. The only difference is that
822 this function is bit rather than byte based.
824 Compare LENGTH bits of VAL1's contents starting at OFFSET1 bits
825 with LENGTH bits of VAL2's contents starting at OFFSET2 bits.
826 Return true if the available bits match. */
829 value_contents_bits_eq (const struct value
*val1
, int offset1
,
830 const struct value
*val2
, int offset2
,
833 /* Each array element corresponds to a ranges source (unavailable,
834 optimized out). '1' is for VAL1, '2' for VAL2. */
835 struct ranges_and_idx rp1
[2], rp2
[2];
837 /* See function description in value.h. */
838 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
840 /* We shouldn't be trying to compare past the end of the values. */
841 gdb_assert (offset1
+ length
842 <= TYPE_LENGTH (val1
->enclosing_type
) * TARGET_CHAR_BIT
);
843 gdb_assert (offset2
+ length
844 <= TYPE_LENGTH (val2
->enclosing_type
) * TARGET_CHAR_BIT
);
846 memset (&rp1
, 0, sizeof (rp1
));
847 memset (&rp2
, 0, sizeof (rp2
));
848 rp1
[0].ranges
= &val1
->unavailable
;
849 rp2
[0].ranges
= &val2
->unavailable
;
850 rp1
[1].ranges
= &val1
->optimized_out
;
851 rp2
[1].ranges
= &val2
->optimized_out
;
855 ULONGEST l
= 0, h
= 0; /* init for gcc -Wall */
858 for (i
= 0; i
< 2; i
++)
860 ULONGEST l_tmp
, h_tmp
;
862 /* The contents only match equal if the invalid/unavailable
863 contents ranges match as well. */
864 if (!find_first_range_overlap_and_match (&rp1
[i
], &rp2
[i
],
865 offset1
, offset2
, length
,
869 /* We're interested in the lowest/first range found. */
870 if (i
== 0 || l_tmp
< l
)
877 /* Compare the available/valid contents. */
878 if (memcmp_with_bit_offsets (val1
->contents
, offset1
,
879 val2
->contents
, offset2
, l
) != 0)
891 value_contents_eq (const struct value
*val1
, LONGEST offset1
,
892 const struct value
*val2
, LONGEST offset2
,
895 return value_contents_bits_eq (val1
, offset1
* TARGET_CHAR_BIT
,
896 val2
, offset2
* TARGET_CHAR_BIT
,
897 length
* TARGET_CHAR_BIT
);
901 /* The value-history records all the values printed by print commands
902 during this session. */
904 static std::vector
<value_ref_ptr
> value_history
;
907 /* List of all value objects currently allocated
908 (except for those released by calls to release_value)
909 This is so they can be freed after each command. */
911 static std::vector
<value_ref_ptr
> all_values
;
913 /* Allocate a lazy value for type TYPE. Its actual content is
914 "lazily" allocated too: the content field of the return value is
915 NULL; it will be allocated when it is fetched from the target. */
918 allocate_value_lazy (struct type
*type
)
922 /* Call check_typedef on our type to make sure that, if TYPE
923 is a TYPE_CODE_TYPEDEF, its length is set to the length
924 of the target type instead of zero. However, we do not
925 replace the typedef type by the target type, because we want
926 to keep the typedef in order to be able to set the VAL's type
927 description correctly. */
928 check_typedef (type
);
930 val
= new struct value (type
);
932 /* Values start out on the all_values chain. */
933 all_values
.emplace_back (val
);
938 /* The maximum size, in bytes, that GDB will try to allocate for a value.
939 The initial value of 64k was not selected for any specific reason, it is
940 just a reasonable starting point. */
942 static int max_value_size
= 65536; /* 64k bytes */
944 /* It is critical that the MAX_VALUE_SIZE is at least as big as the size of
945 LONGEST, otherwise GDB will not be able to parse integer values from the
946 CLI; for example if the MAX_VALUE_SIZE could be set to 1 then GDB would
947 be unable to parse "set max-value-size 2".
949 As we want a consistent GDB experience across hosts with different sizes
950 of LONGEST, this arbitrary minimum value was selected, so long as this
951 is bigger than LONGEST on all GDB supported hosts we're fine. */
953 #define MIN_VALUE_FOR_MAX_VALUE_SIZE 16
954 gdb_static_assert (sizeof (LONGEST
) <= MIN_VALUE_FOR_MAX_VALUE_SIZE
);
956 /* Implement the "set max-value-size" command. */
959 set_max_value_size (const char *args
, int from_tty
,
960 struct cmd_list_element
*c
)
962 gdb_assert (max_value_size
== -1 || max_value_size
>= 0);
964 if (max_value_size
> -1 && max_value_size
< MIN_VALUE_FOR_MAX_VALUE_SIZE
)
966 max_value_size
= MIN_VALUE_FOR_MAX_VALUE_SIZE
;
967 error (_("max-value-size set too low, increasing to %d bytes"),
972 /* Implement the "show max-value-size" command. */
975 show_max_value_size (struct ui_file
*file
, int from_tty
,
976 struct cmd_list_element
*c
, const char *value
)
978 if (max_value_size
== -1)
979 fprintf_filtered (file
, _("Maximum value size is unlimited.\n"));
981 fprintf_filtered (file
, _("Maximum value size is %d bytes.\n"),
985 /* Called before we attempt to allocate or reallocate a buffer for the
986 contents of a value. TYPE is the type of the value for which we are
987 allocating the buffer. If the buffer is too large (based on the user
988 controllable setting) then throw an error. If this function returns
989 then we should attempt to allocate the buffer. */
992 check_type_length_before_alloc (const struct type
*type
)
994 unsigned int length
= TYPE_LENGTH (type
);
996 if (max_value_size
> -1 && length
> max_value_size
)
998 if (TYPE_NAME (type
) != NULL
)
999 error (_("value of type `%s' requires %u bytes, which is more "
1000 "than max-value-size"), TYPE_NAME (type
), length
);
1002 error (_("value requires %u bytes, which is more than "
1003 "max-value-size"), length
);
1007 /* Allocate the contents of VAL if it has not been allocated yet. */
1010 allocate_value_contents (struct value
*val
)
1014 check_type_length_before_alloc (val
->enclosing_type
);
1016 = (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
1020 /* Allocate a value and its contents for type TYPE. */
1023 allocate_value (struct type
*type
)
1025 struct value
*val
= allocate_value_lazy (type
);
1027 allocate_value_contents (val
);
1032 /* Allocate a value that has the correct length
1033 for COUNT repetitions of type TYPE. */
1036 allocate_repeat_value (struct type
*type
, int count
)
1038 int low_bound
= current_language
->string_lower_bound
; /* ??? */
1039 /* FIXME-type-allocation: need a way to free this type when we are
1041 struct type
*array_type
1042 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
1044 return allocate_value (array_type
);
1048 allocate_computed_value (struct type
*type
,
1049 const struct lval_funcs
*funcs
,
1052 struct value
*v
= allocate_value_lazy (type
);
1054 VALUE_LVAL (v
) = lval_computed
;
1055 v
->location
.computed
.funcs
= funcs
;
1056 v
->location
.computed
.closure
= closure
;
1061 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
1064 allocate_optimized_out_value (struct type
*type
)
1066 struct value
*retval
= allocate_value_lazy (type
);
1068 mark_value_bytes_optimized_out (retval
, 0, TYPE_LENGTH (type
));
1069 set_value_lazy (retval
, 0);
1073 /* Accessor methods. */
1076 value_type (const struct value
*value
)
1081 deprecated_set_value_type (struct value
*value
, struct type
*type
)
1087 value_offset (const struct value
*value
)
1089 return value
->offset
;
1092 set_value_offset (struct value
*value
, LONGEST offset
)
1094 value
->offset
= offset
;
1098 value_bitpos (const struct value
*value
)
1100 return value
->bitpos
;
1103 set_value_bitpos (struct value
*value
, LONGEST bit
)
1105 value
->bitpos
= bit
;
1109 value_bitsize (const struct value
*value
)
1111 return value
->bitsize
;
1114 set_value_bitsize (struct value
*value
, LONGEST bit
)
1116 value
->bitsize
= bit
;
1120 value_parent (const struct value
*value
)
1122 return value
->parent
.get ();
1128 set_value_parent (struct value
*value
, struct value
*parent
)
1130 value
->parent
= value_ref_ptr (value_incref (parent
));
1134 value_contents_raw (struct value
*value
)
1136 struct gdbarch
*arch
= get_value_arch (value
);
1137 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1139 allocate_value_contents (value
);
1140 return value
->contents
+ value
->embedded_offset
* unit_size
;
1144 value_contents_all_raw (struct value
*value
)
1146 allocate_value_contents (value
);
1147 return value
->contents
;
1151 value_enclosing_type (const struct value
*value
)
1153 return value
->enclosing_type
;
1156 /* Look at value.h for description. */
1159 value_actual_type (struct value
*value
, int resolve_simple_types
,
1160 int *real_type_found
)
1162 struct value_print_options opts
;
1163 struct type
*result
;
1165 get_user_print_options (&opts
);
1167 if (real_type_found
)
1168 *real_type_found
= 0;
1169 result
= value_type (value
);
1170 if (opts
.objectprint
)
1172 /* If result's target type is TYPE_CODE_STRUCT, proceed to
1173 fetch its rtti type. */
1174 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (result
))
1175 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
1177 && !value_optimized_out (value
))
1179 struct type
*real_type
;
1181 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
1184 if (real_type_found
)
1185 *real_type_found
= 1;
1189 else if (resolve_simple_types
)
1191 if (real_type_found
)
1192 *real_type_found
= 1;
1193 result
= value_enclosing_type (value
);
1201 error_value_optimized_out (void)
1203 error (_("value has been optimized out"));
1207 require_not_optimized_out (const struct value
*value
)
1209 if (!value
->optimized_out
.empty ())
1211 if (value
->lval
== lval_register
)
1212 error (_("register has not been saved in frame"));
1214 error_value_optimized_out ();
1219 require_available (const struct value
*value
)
1221 if (!value
->unavailable
.empty ())
1222 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
1226 value_contents_for_printing (struct value
*value
)
1229 value_fetch_lazy (value
);
1230 return value
->contents
;
1234 value_contents_for_printing_const (const struct value
*value
)
1236 gdb_assert (!value
->lazy
);
1237 return value
->contents
;
1241 value_contents_all (struct value
*value
)
1243 const gdb_byte
*result
= value_contents_for_printing (value
);
1244 require_not_optimized_out (value
);
1245 require_available (value
);
1249 /* Copy ranges in SRC_RANGE that overlap [SRC_BIT_OFFSET,
1250 SRC_BIT_OFFSET+BIT_LENGTH) ranges into *DST_RANGE, adjusted. */
1253 ranges_copy_adjusted (std::vector
<range
> *dst_range
, int dst_bit_offset
,
1254 const std::vector
<range
> &src_range
, int src_bit_offset
,
1257 for (const range
&r
: src_range
)
1261 l
= std::max (r
.offset
, (LONGEST
) src_bit_offset
);
1262 h
= std::min (r
.offset
+ r
.length
,
1263 (LONGEST
) src_bit_offset
+ bit_length
);
1266 insert_into_bit_range_vector (dst_range
,
1267 dst_bit_offset
+ (l
- src_bit_offset
),
1272 /* Copy the ranges metadata in SRC that overlaps [SRC_BIT_OFFSET,
1273 SRC_BIT_OFFSET+BIT_LENGTH) into DST, adjusted. */
1276 value_ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
1277 const struct value
*src
, int src_bit_offset
,
1280 ranges_copy_adjusted (&dst
->unavailable
, dst_bit_offset
,
1281 src
->unavailable
, src_bit_offset
,
1283 ranges_copy_adjusted (&dst
->optimized_out
, dst_bit_offset
,
1284 src
->optimized_out
, src_bit_offset
,
1288 /* Copy LENGTH target addressable memory units of SRC value's (all) contents
1289 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
1290 contents, starting at DST_OFFSET. If unavailable contents are
1291 being copied from SRC, the corresponding DST contents are marked
1292 unavailable accordingly. Neither DST nor SRC may be lazy
1295 It is assumed the contents of DST in the [DST_OFFSET,
1296 DST_OFFSET+LENGTH) range are wholly available. */
1299 value_contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
1300 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1302 LONGEST src_bit_offset
, dst_bit_offset
, bit_length
;
1303 struct gdbarch
*arch
= get_value_arch (src
);
1304 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
1306 /* A lazy DST would make that this copy operation useless, since as
1307 soon as DST's contents were un-lazied (by a later value_contents
1308 call, say), the contents would be overwritten. A lazy SRC would
1309 mean we'd be copying garbage. */
1310 gdb_assert (!dst
->lazy
&& !src
->lazy
);
1312 /* The overwritten DST range gets unavailability ORed in, not
1313 replaced. Make sure to remember to implement replacing if it
1314 turns out actually necessary. */
1315 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
1316 gdb_assert (!value_bits_any_optimized_out (dst
,
1317 TARGET_CHAR_BIT
* dst_offset
,
1318 TARGET_CHAR_BIT
* length
));
1320 /* Copy the data. */
1321 memcpy (value_contents_all_raw (dst
) + dst_offset
* unit_size
,
1322 value_contents_all_raw (src
) + src_offset
* unit_size
,
1323 length
* unit_size
);
1325 /* Copy the meta-data, adjusted. */
1326 src_bit_offset
= src_offset
* unit_size
* HOST_CHAR_BIT
;
1327 dst_bit_offset
= dst_offset
* unit_size
* HOST_CHAR_BIT
;
1328 bit_length
= length
* unit_size
* HOST_CHAR_BIT
;
1330 value_ranges_copy_adjusted (dst
, dst_bit_offset
,
1331 src
, src_bit_offset
,
1335 /* Copy LENGTH bytes of SRC value's (all) contents
1336 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
1337 (all) contents, starting at DST_OFFSET. If unavailable contents
1338 are being copied from SRC, the corresponding DST contents are
1339 marked unavailable accordingly. DST must not be lazy. If SRC is
1340 lazy, it will be fetched now.
1342 It is assumed the contents of DST in the [DST_OFFSET,
1343 DST_OFFSET+LENGTH) range are wholly available. */
1346 value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
1347 struct value
*src
, LONGEST src_offset
, LONGEST length
)
1350 value_fetch_lazy (src
);
1352 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
1356 value_lazy (const struct value
*value
)
1362 set_value_lazy (struct value
*value
, int val
)
1368 value_stack (const struct value
*value
)
1370 return value
->stack
;
1374 set_value_stack (struct value
*value
, int val
)
1380 value_contents (struct value
*value
)
1382 const gdb_byte
*result
= value_contents_writeable (value
);
1383 require_not_optimized_out (value
);
1384 require_available (value
);
1389 value_contents_writeable (struct value
*value
)
1392 value_fetch_lazy (value
);
1393 return value_contents_raw (value
);
1397 value_optimized_out (struct value
*value
)
1399 /* We can only know if a value is optimized out once we have tried to
1401 if (value
->optimized_out
.empty () && value
->lazy
)
1405 value_fetch_lazy (value
);
1407 CATCH (ex
, RETURN_MASK_ERROR
)
1409 /* Fall back to checking value->optimized_out. */
1414 return !value
->optimized_out
.empty ();
1417 /* Mark contents of VALUE as optimized out, starting at OFFSET bytes, and
1418 the following LENGTH bytes. */
1421 mark_value_bytes_optimized_out (struct value
*value
, int offset
, int length
)
1423 mark_value_bits_optimized_out (value
,
1424 offset
* TARGET_CHAR_BIT
,
1425 length
* TARGET_CHAR_BIT
);
1431 mark_value_bits_optimized_out (struct value
*value
,
1432 LONGEST offset
, LONGEST length
)
1434 insert_into_bit_range_vector (&value
->optimized_out
, offset
, length
);
1438 value_bits_synthetic_pointer (const struct value
*value
,
1439 LONGEST offset
, LONGEST length
)
1441 if (value
->lval
!= lval_computed
1442 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1444 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1450 value_embedded_offset (const struct value
*value
)
1452 return value
->embedded_offset
;
1456 set_value_embedded_offset (struct value
*value
, LONGEST val
)
1458 value
->embedded_offset
= val
;
1462 value_pointed_to_offset (const struct value
*value
)
1464 return value
->pointed_to_offset
;
1468 set_value_pointed_to_offset (struct value
*value
, LONGEST val
)
1470 value
->pointed_to_offset
= val
;
1473 const struct lval_funcs
*
1474 value_computed_funcs (const struct value
*v
)
1476 gdb_assert (value_lval_const (v
) == lval_computed
);
1478 return v
->location
.computed
.funcs
;
1482 value_computed_closure (const struct value
*v
)
1484 gdb_assert (v
->lval
== lval_computed
);
1486 return v
->location
.computed
.closure
;
1490 deprecated_value_lval_hack (struct value
*value
)
1492 return &value
->lval
;
1496 value_lval_const (const struct value
*value
)
1502 value_address (const struct value
*value
)
1504 if (value
->lval
!= lval_memory
)
1506 if (value
->parent
!= NULL
)
1507 return value_address (value
->parent
.get ()) + value
->offset
;
1508 if (NULL
!= TYPE_DATA_LOCATION (value_type (value
)))
1510 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (value_type (value
)));
1511 return TYPE_DATA_LOCATION_ADDR (value_type (value
));
1514 return value
->location
.address
+ value
->offset
;
1518 value_raw_address (const struct value
*value
)
1520 if (value
->lval
!= lval_memory
)
1522 return value
->location
.address
;
1526 set_value_address (struct value
*value
, CORE_ADDR addr
)
1528 gdb_assert (value
->lval
== lval_memory
);
1529 value
->location
.address
= addr
;
1532 struct internalvar
**
1533 deprecated_value_internalvar_hack (struct value
*value
)
1535 return &value
->location
.internalvar
;
1539 deprecated_value_next_frame_id_hack (struct value
*value
)
1541 gdb_assert (value
->lval
== lval_register
);
1542 return &value
->location
.reg
.next_frame_id
;
1546 deprecated_value_regnum_hack (struct value
*value
)
1548 gdb_assert (value
->lval
== lval_register
);
1549 return &value
->location
.reg
.regnum
;
1553 deprecated_value_modifiable (const struct value
*value
)
1555 return value
->modifiable
;
1558 /* Return a mark in the value chain. All values allocated after the
1559 mark is obtained (except for those released) are subject to being freed
1560 if a subsequent value_free_to_mark is passed the mark. */
1564 if (all_values
.empty ())
1566 return all_values
.back ().get ();
1569 /* Take a reference to VAL. VAL will not be deallocated until all
1570 references are released. */
1573 value_incref (struct value
*val
)
1575 val
->reference_count
++;
1579 /* Release a reference to VAL, which was acquired with value_incref.
1580 This function is also called to deallocate values from the value
1584 value_decref (struct value
*val
)
1588 gdb_assert (val
->reference_count
> 0);
1589 val
->reference_count
--;
1590 if (val
->reference_count
== 0)
1595 /* Free all values allocated since MARK was obtained by value_mark
1596 (except for those released). */
1598 value_free_to_mark (const struct value
*mark
)
1600 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1601 if (iter
== all_values
.end ())
1602 all_values
.clear ();
1604 all_values
.erase (iter
+ 1, all_values
.end ());
1607 /* Remove VAL from the chain all_values
1608 so it will not be freed automatically. */
1611 release_value (struct value
*val
)
1616 return value_ref_ptr ();
1618 std::vector
<value_ref_ptr
>::reverse_iterator iter
;
1619 for (iter
= all_values
.rbegin (); iter
!= all_values
.rend (); ++iter
)
1623 value_ref_ptr result
= *iter
;
1624 all_values
.erase (iter
.base () - 1);
1629 /* We must always return an owned reference. Normally this happens
1630 because we transfer the reference from the value chain, but in
1631 this case the value was not on the chain. */
1632 return value_ref_ptr (value_incref (val
));
1637 std::vector
<value_ref_ptr
>
1638 value_release_to_mark (const struct value
*mark
)
1640 std::vector
<value_ref_ptr
> result
;
1642 auto iter
= std::find (all_values
.begin (), all_values
.end (), mark
);
1643 if (iter
== all_values
.end ())
1644 std::swap (result
, all_values
);
1647 std::move (iter
+ 1, all_values
.end (), std::back_inserter (result
));
1648 all_values
.erase (iter
+ 1, all_values
.end ());
1650 std::reverse (result
.begin (), result
.end ());
1654 /* Return a copy of the value ARG.
1655 It contains the same contents, for same memory address,
1656 but it's a different block of storage. */
1659 value_copy (struct value
*arg
)
1661 struct type
*encl_type
= value_enclosing_type (arg
);
1664 if (value_lazy (arg
))
1665 val
= allocate_value_lazy (encl_type
);
1667 val
= allocate_value (encl_type
);
1668 val
->type
= arg
->type
;
1669 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1670 val
->location
= arg
->location
;
1671 val
->offset
= arg
->offset
;
1672 val
->bitpos
= arg
->bitpos
;
1673 val
->bitsize
= arg
->bitsize
;
1674 val
->lazy
= arg
->lazy
;
1675 val
->embedded_offset
= value_embedded_offset (arg
);
1676 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1677 val
->modifiable
= arg
->modifiable
;
1678 if (!value_lazy (val
))
1680 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1681 TYPE_LENGTH (value_enclosing_type (arg
)));
1684 val
->unavailable
= arg
->unavailable
;
1685 val
->optimized_out
= arg
->optimized_out
;
1686 val
->parent
= arg
->parent
;
1687 if (VALUE_LVAL (val
) == lval_computed
)
1689 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1691 if (funcs
->copy_closure
)
1692 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1697 /* Return a "const" and/or "volatile" qualified version of the value V.
1698 If CNST is true, then the returned value will be qualified with
1700 if VOLTL is true, then the returned value will be qualified with
1704 make_cv_value (int cnst
, int voltl
, struct value
*v
)
1706 struct type
*val_type
= value_type (v
);
1707 struct type
*enclosing_type
= value_enclosing_type (v
);
1708 struct value
*cv_val
= value_copy (v
);
1710 deprecated_set_value_type (cv_val
,
1711 make_cv_type (cnst
, voltl
, val_type
, NULL
));
1712 set_value_enclosing_type (cv_val
,
1713 make_cv_type (cnst
, voltl
, enclosing_type
, NULL
));
1718 /* Return a version of ARG that is non-lvalue. */
1721 value_non_lval (struct value
*arg
)
1723 if (VALUE_LVAL (arg
) != not_lval
)
1725 struct type
*enc_type
= value_enclosing_type (arg
);
1726 struct value
*val
= allocate_value (enc_type
);
1728 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1729 TYPE_LENGTH (enc_type
));
1730 val
->type
= arg
->type
;
1731 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1732 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1738 /* Write contents of V at ADDR and set its lval type to be LVAL_MEMORY. */
1741 value_force_lval (struct value
*v
, CORE_ADDR addr
)
1743 gdb_assert (VALUE_LVAL (v
) == not_lval
);
1745 write_memory (addr
, value_contents_raw (v
), TYPE_LENGTH (value_type (v
)));
1746 v
->lval
= lval_memory
;
1747 v
->location
.address
= addr
;
1751 set_value_component_location (struct value
*component
,
1752 const struct value
*whole
)
1756 gdb_assert (whole
->lval
!= lval_xcallable
);
1758 if (whole
->lval
== lval_internalvar
)
1759 VALUE_LVAL (component
) = lval_internalvar_component
;
1761 VALUE_LVAL (component
) = whole
->lval
;
1763 component
->location
= whole
->location
;
1764 if (whole
->lval
== lval_computed
)
1766 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1768 if (funcs
->copy_closure
)
1769 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1772 /* If type has a dynamic resolved location property
1773 update it's value address. */
1774 type
= value_type (whole
);
1775 if (NULL
!= TYPE_DATA_LOCATION (type
)
1776 && TYPE_DATA_LOCATION_KIND (type
) == PROP_CONST
)
1777 set_value_address (component
, TYPE_DATA_LOCATION_ADDR (type
));
1780 /* Access to the value history. */
1782 /* Record a new value in the value history.
1783 Returns the absolute history index of the entry. */
1786 record_latest_value (struct value
*val
)
1790 /* We don't want this value to have anything to do with the inferior anymore.
1791 In particular, "set $1 = 50" should not affect the variable from which
1792 the value was taken, and fast watchpoints should be able to assume that
1793 a value on the value history never changes. */
1794 if (value_lazy (val
))
1795 value_fetch_lazy (val
);
1796 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1797 from. This is a bit dubious, because then *&$1 does not just return $1
1798 but the current contents of that location. c'est la vie... */
1799 val
->modifiable
= 0;
1801 value_history
.push_back (release_value (val
));
1803 return value_history
.size ();
1806 /* Return a copy of the value in the history with sequence number NUM. */
1809 access_value_history (int num
)
1815 absnum
+= value_history
.size ();
1820 error (_("The history is empty."));
1822 error (_("There is only one value in the history."));
1824 error (_("History does not go back to $$%d."), -num
);
1826 if (absnum
> value_history
.size ())
1827 error (_("History has not yet reached $%d."), absnum
);
1831 return value_copy (value_history
[absnum
].get ());
1835 show_values (const char *num_exp
, int from_tty
)
1843 /* "show values +" should print from the stored position.
1844 "show values <exp>" should print around value number <exp>. */
1845 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1846 num
= parse_and_eval_long (num_exp
) - 5;
1850 /* "show values" means print the last 10 values. */
1851 num
= value_history
.size () - 9;
1857 for (i
= num
; i
< num
+ 10 && i
<= value_history
.size (); i
++)
1859 struct value_print_options opts
;
1861 val
= access_value_history (i
);
1862 printf_filtered (("$%d = "), i
);
1863 get_user_print_options (&opts
);
1864 value_print (val
, gdb_stdout
, &opts
);
1865 printf_filtered (("\n"));
1868 /* The next "show values +" should start after what we just printed. */
1871 /* Hitting just return after this command should do the same thing as
1872 "show values +". If num_exp is null, this is unnecessary, since
1873 "show values +" is not useful after "show values". */
1874 if (from_tty
&& num_exp
)
1875 set_repeat_arguments ("+");
1878 enum internalvar_kind
1880 /* The internal variable is empty. */
1883 /* The value of the internal variable is provided directly as
1884 a GDB value object. */
1887 /* A fresh value is computed via a call-back routine on every
1888 access to the internal variable. */
1889 INTERNALVAR_MAKE_VALUE
,
1891 /* The internal variable holds a GDB internal convenience function. */
1892 INTERNALVAR_FUNCTION
,
1894 /* The variable holds an integer value. */
1895 INTERNALVAR_INTEGER
,
1897 /* The variable holds a GDB-provided string. */
1901 union internalvar_data
1903 /* A value object used with INTERNALVAR_VALUE. */
1904 struct value
*value
;
1906 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1909 /* The functions to call. */
1910 const struct internalvar_funcs
*functions
;
1912 /* The function's user-data. */
1916 /* The internal function used with INTERNALVAR_FUNCTION. */
1919 struct internal_function
*function
;
1920 /* True if this is the canonical name for the function. */
1924 /* An integer value used with INTERNALVAR_INTEGER. */
1927 /* If type is non-NULL, it will be used as the type to generate
1928 a value for this internal variable. If type is NULL, a default
1929 integer type for the architecture is used. */
1934 /* A string value used with INTERNALVAR_STRING. */
1938 /* Internal variables. These are variables within the debugger
1939 that hold values assigned by debugger commands.
1940 The user refers to them with a '$' prefix
1941 that does not appear in the variable names stored internally. */
1945 struct internalvar
*next
;
1948 /* We support various different kinds of content of an internal variable.
1949 enum internalvar_kind specifies the kind, and union internalvar_data
1950 provides the data associated with this particular kind. */
1952 enum internalvar_kind kind
;
1954 union internalvar_data u
;
1957 static struct internalvar
*internalvars
;
1959 /* If the variable does not already exist create it and give it the
1960 value given. If no value is given then the default is zero. */
1962 init_if_undefined_command (const char* args
, int from_tty
)
1964 struct internalvar
* intvar
;
1966 /* Parse the expression - this is taken from set_command(). */
1967 expression_up expr
= parse_expression (args
);
1969 /* Validate the expression.
1970 Was the expression an assignment?
1971 Or even an expression at all? */
1972 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1973 error (_("Init-if-undefined requires an assignment expression."));
1975 /* Extract the variable from the parsed expression.
1976 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1977 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1978 error (_("The first parameter to init-if-undefined "
1979 "should be a GDB variable."));
1980 intvar
= expr
->elts
[2].internalvar
;
1982 /* Only evaluate the expression if the lvalue is void.
1983 This may still fail if the expresssion is invalid. */
1984 if (intvar
->kind
== INTERNALVAR_VOID
)
1985 evaluate_expression (expr
.get ());
1989 /* Look up an internal variable with name NAME. NAME should not
1990 normally include a dollar sign.
1992 If the specified internal variable does not exist,
1993 the return value is NULL. */
1995 struct internalvar
*
1996 lookup_only_internalvar (const char *name
)
1998 struct internalvar
*var
;
2000 for (var
= internalvars
; var
; var
= var
->next
)
2001 if (strcmp (var
->name
, name
) == 0)
2007 /* Complete NAME by comparing it to the names of internal
2011 complete_internalvar (completion_tracker
&tracker
, const char *name
)
2013 struct internalvar
*var
;
2016 len
= strlen (name
);
2018 for (var
= internalvars
; var
; var
= var
->next
)
2019 if (strncmp (var
->name
, name
, len
) == 0)
2021 gdb::unique_xmalloc_ptr
<char> copy (xstrdup (var
->name
));
2023 tracker
.add_completion (std::move (copy
));
2027 /* Create an internal variable with name NAME and with a void value.
2028 NAME should not normally include a dollar sign. */
2030 struct internalvar
*
2031 create_internalvar (const char *name
)
2033 struct internalvar
*var
= XNEW (struct internalvar
);
2035 var
->name
= concat (name
, (char *)NULL
);
2036 var
->kind
= INTERNALVAR_VOID
;
2037 var
->next
= internalvars
;
2042 /* Create an internal variable with name NAME and register FUN as the
2043 function that value_of_internalvar uses to create a value whenever
2044 this variable is referenced. NAME should not normally include a
2045 dollar sign. DATA is passed uninterpreted to FUN when it is
2046 called. CLEANUP, if not NULL, is called when the internal variable
2047 is destroyed. It is passed DATA as its only argument. */
2049 struct internalvar
*
2050 create_internalvar_type_lazy (const char *name
,
2051 const struct internalvar_funcs
*funcs
,
2054 struct internalvar
*var
= create_internalvar (name
);
2056 var
->kind
= INTERNALVAR_MAKE_VALUE
;
2057 var
->u
.make_value
.functions
= funcs
;
2058 var
->u
.make_value
.data
= data
;
2062 /* See documentation in value.h. */
2065 compile_internalvar_to_ax (struct internalvar
*var
,
2066 struct agent_expr
*expr
,
2067 struct axs_value
*value
)
2069 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2070 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
2073 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
2074 var
->u
.make_value
.data
);
2078 /* Look up an internal variable with name NAME. NAME should not
2079 normally include a dollar sign.
2081 If the specified internal variable does not exist,
2082 one is created, with a void value. */
2084 struct internalvar
*
2085 lookup_internalvar (const char *name
)
2087 struct internalvar
*var
;
2089 var
= lookup_only_internalvar (name
);
2093 return create_internalvar (name
);
2096 /* Return current value of internal variable VAR. For variables that
2097 are not inherently typed, use a value type appropriate for GDBARCH. */
2100 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
2103 struct trace_state_variable
*tsv
;
2105 /* If there is a trace state variable of the same name, assume that
2106 is what we really want to see. */
2107 tsv
= find_trace_state_variable (var
->name
);
2110 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
2112 if (tsv
->value_known
)
2113 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
2116 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2122 case INTERNALVAR_VOID
:
2123 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
2126 case INTERNALVAR_FUNCTION
:
2127 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
2130 case INTERNALVAR_INTEGER
:
2131 if (!var
->u
.integer
.type
)
2132 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
2133 var
->u
.integer
.val
);
2135 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
2138 case INTERNALVAR_STRING
:
2139 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
2140 builtin_type (gdbarch
)->builtin_char
);
2143 case INTERNALVAR_VALUE
:
2144 val
= value_copy (var
->u
.value
);
2145 if (value_lazy (val
))
2146 value_fetch_lazy (val
);
2149 case INTERNALVAR_MAKE_VALUE
:
2150 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
2151 var
->u
.make_value
.data
);
2155 internal_error (__FILE__
, __LINE__
, _("bad kind"));
2158 /* Change the VALUE_LVAL to lval_internalvar so that future operations
2159 on this value go back to affect the original internal variable.
2161 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
2162 no underlying modifyable state in the internal variable.
2164 Likewise, if the variable's value is a computed lvalue, we want
2165 references to it to produce another computed lvalue, where
2166 references and assignments actually operate through the
2167 computed value's functions.
2169 This means that internal variables with computed values
2170 behave a little differently from other internal variables:
2171 assignments to them don't just replace the previous value
2172 altogether. At the moment, this seems like the behavior we
2175 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
2176 && val
->lval
!= lval_computed
)
2178 VALUE_LVAL (val
) = lval_internalvar
;
2179 VALUE_INTERNALVAR (val
) = var
;
2186 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
2188 if (var
->kind
== INTERNALVAR_INTEGER
)
2190 *result
= var
->u
.integer
.val
;
2194 if (var
->kind
== INTERNALVAR_VALUE
)
2196 struct type
*type
= check_typedef (value_type (var
->u
.value
));
2198 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
2200 *result
= value_as_long (var
->u
.value
);
2209 get_internalvar_function (struct internalvar
*var
,
2210 struct internal_function
**result
)
2214 case INTERNALVAR_FUNCTION
:
2215 *result
= var
->u
.fn
.function
;
2224 set_internalvar_component (struct internalvar
*var
,
2225 LONGEST offset
, LONGEST bitpos
,
2226 LONGEST bitsize
, struct value
*newval
)
2229 struct gdbarch
*arch
;
2234 case INTERNALVAR_VALUE
:
2235 addr
= value_contents_writeable (var
->u
.value
);
2236 arch
= get_value_arch (var
->u
.value
);
2237 unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2240 modify_field (value_type (var
->u
.value
), addr
+ offset
,
2241 value_as_long (newval
), bitpos
, bitsize
);
2243 memcpy (addr
+ offset
* unit_size
, value_contents (newval
),
2244 TYPE_LENGTH (value_type (newval
)));
2248 /* We can never get a component of any other kind. */
2249 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
2254 set_internalvar (struct internalvar
*var
, struct value
*val
)
2256 enum internalvar_kind new_kind
;
2257 union internalvar_data new_data
= { 0 };
2259 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
2260 error (_("Cannot overwrite convenience function %s"), var
->name
);
2262 /* Prepare new contents. */
2263 switch (TYPE_CODE (check_typedef (value_type (val
))))
2265 case TYPE_CODE_VOID
:
2266 new_kind
= INTERNALVAR_VOID
;
2269 case TYPE_CODE_INTERNAL_FUNCTION
:
2270 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2271 new_kind
= INTERNALVAR_FUNCTION
;
2272 get_internalvar_function (VALUE_INTERNALVAR (val
),
2273 &new_data
.fn
.function
);
2274 /* Copies created here are never canonical. */
2278 new_kind
= INTERNALVAR_VALUE
;
2279 new_data
.value
= value_copy (val
);
2280 new_data
.value
->modifiable
= 1;
2282 /* Force the value to be fetched from the target now, to avoid problems
2283 later when this internalvar is referenced and the target is gone or
2285 if (value_lazy (new_data
.value
))
2286 value_fetch_lazy (new_data
.value
);
2288 /* Release the value from the value chain to prevent it from being
2289 deleted by free_all_values. From here on this function should not
2290 call error () until new_data is installed into the var->u to avoid
2292 release_value (new_data
.value
).release ();
2294 /* Internal variables which are created from values with a dynamic
2295 location don't need the location property of the origin anymore.
2296 The resolved dynamic location is used prior then any other address
2297 when accessing the value.
2298 If we keep it, we would still refer to the origin value.
2299 Remove the location property in case it exist. */
2300 remove_dyn_prop (DYN_PROP_DATA_LOCATION
, value_type (new_data
.value
));
2305 /* Clean up old contents. */
2306 clear_internalvar (var
);
2309 var
->kind
= new_kind
;
2311 /* End code which must not call error(). */
2315 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2317 /* Clean up old contents. */
2318 clear_internalvar (var
);
2320 var
->kind
= INTERNALVAR_INTEGER
;
2321 var
->u
.integer
.type
= NULL
;
2322 var
->u
.integer
.val
= l
;
2326 set_internalvar_string (struct internalvar
*var
, const char *string
)
2328 /* Clean up old contents. */
2329 clear_internalvar (var
);
2331 var
->kind
= INTERNALVAR_STRING
;
2332 var
->u
.string
= xstrdup (string
);
2336 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2338 /* Clean up old contents. */
2339 clear_internalvar (var
);
2341 var
->kind
= INTERNALVAR_FUNCTION
;
2342 var
->u
.fn
.function
= f
;
2343 var
->u
.fn
.canonical
= 1;
2344 /* Variables installed here are always the canonical version. */
2348 clear_internalvar (struct internalvar
*var
)
2350 /* Clean up old contents. */
2353 case INTERNALVAR_VALUE
:
2354 value_decref (var
->u
.value
);
2357 case INTERNALVAR_STRING
:
2358 xfree (var
->u
.string
);
2361 case INTERNALVAR_MAKE_VALUE
:
2362 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2363 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2370 /* Reset to void kind. */
2371 var
->kind
= INTERNALVAR_VOID
;
2375 internalvar_name (const struct internalvar
*var
)
2380 static struct internal_function
*
2381 create_internal_function (const char *name
,
2382 internal_function_fn handler
, void *cookie
)
2384 struct internal_function
*ifn
= XNEW (struct internal_function
);
2386 ifn
->name
= xstrdup (name
);
2387 ifn
->handler
= handler
;
2388 ifn
->cookie
= cookie
;
2393 value_internal_function_name (struct value
*val
)
2395 struct internal_function
*ifn
;
2398 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2399 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2400 gdb_assert (result
);
2406 call_internal_function (struct gdbarch
*gdbarch
,
2407 const struct language_defn
*language
,
2408 struct value
*func
, int argc
, struct value
**argv
)
2410 struct internal_function
*ifn
;
2413 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2414 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2415 gdb_assert (result
);
2417 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2420 /* The 'function' command. This does nothing -- it is just a
2421 placeholder to let "help function NAME" work. This is also used as
2422 the implementation of the sub-command that is created when
2423 registering an internal function. */
2425 function_command (const char *command
, int from_tty
)
2430 /* Clean up if an internal function's command is destroyed. */
2432 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2434 xfree ((char *) self
->name
);
2435 xfree ((char *) self
->doc
);
2438 /* Add a new internal function. NAME is the name of the function; DOC
2439 is a documentation string describing the function. HANDLER is
2440 called when the function is invoked. COOKIE is an arbitrary
2441 pointer which is passed to HANDLER and is intended for "user
2444 add_internal_function (const char *name
, const char *doc
,
2445 internal_function_fn handler
, void *cookie
)
2447 struct cmd_list_element
*cmd
;
2448 struct internal_function
*ifn
;
2449 struct internalvar
*var
= lookup_internalvar (name
);
2451 ifn
= create_internal_function (name
, handler
, cookie
);
2452 set_internalvar_function (var
, ifn
);
2454 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2456 cmd
->destroyer
= function_destroyer
;
2459 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2460 prevent cycles / duplicates. */
2463 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2464 htab_t copied_types
)
2466 if (TYPE_OBJFILE (value
->type
) == objfile
)
2467 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2469 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2470 value
->enclosing_type
= copy_type_recursive (objfile
,
2471 value
->enclosing_type
,
2475 /* Likewise for internal variable VAR. */
2478 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2479 htab_t copied_types
)
2483 case INTERNALVAR_INTEGER
:
2484 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2486 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2489 case INTERNALVAR_VALUE
:
2490 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2495 /* Update the internal variables and value history when OBJFILE is
2496 discarded; we must copy the types out of the objfile. New global types
2497 will be created for every convenience variable which currently points to
2498 this objfile's types, and the convenience variables will be adjusted to
2499 use the new global types. */
2502 preserve_values (struct objfile
*objfile
)
2504 htab_t copied_types
;
2505 struct internalvar
*var
;
2508 /* Create the hash table. We allocate on the objfile's obstack, since
2509 it is soon to be deleted. */
2510 copied_types
= create_copied_types_hash (objfile
);
2512 for (const value_ref_ptr
&item
: value_history
)
2513 preserve_one_value (item
.get (), objfile
, copied_types
);
2515 for (var
= internalvars
; var
; var
= var
->next
)
2516 preserve_one_internalvar (var
, objfile
, copied_types
);
2518 preserve_ext_lang_values (objfile
, copied_types
);
2520 htab_delete (copied_types
);
2524 show_convenience (const char *ignore
, int from_tty
)
2526 struct gdbarch
*gdbarch
= get_current_arch ();
2527 struct internalvar
*var
;
2529 struct value_print_options opts
;
2531 get_user_print_options (&opts
);
2532 for (var
= internalvars
; var
; var
= var
->next
)
2539 printf_filtered (("$%s = "), var
->name
);
2545 val
= value_of_internalvar (gdbarch
, var
);
2546 value_print (val
, gdb_stdout
, &opts
);
2548 CATCH (ex
, RETURN_MASK_ERROR
)
2550 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2554 printf_filtered (("\n"));
2558 /* This text does not mention convenience functions on purpose.
2559 The user can't create them except via Python, and if Python support
2560 is installed this message will never be printed ($_streq will
2562 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2563 "Convenience variables have "
2564 "names starting with \"$\";\n"
2565 "use \"set\" as in \"set "
2566 "$foo = 5\" to define them.\n"));
2574 value_from_xmethod (xmethod_worker_up
&&worker
)
2578 v
= allocate_value (builtin_type (target_gdbarch ())->xmethod
);
2579 v
->lval
= lval_xcallable
;
2580 v
->location
.xm_worker
= worker
.release ();
2586 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
2589 result_type_of_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2591 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2592 && method
->lval
== lval_xcallable
&& argc
> 0);
2594 return method
->location
.xm_worker
->get_result_type
2595 (argv
[0], argv
+ 1, argc
- 1);
2598 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value METHOD. */
2601 call_xmethod (struct value
*method
, int argc
, struct value
**argv
)
2603 gdb_assert (TYPE_CODE (value_type (method
)) == TYPE_CODE_XMETHOD
2604 && method
->lval
== lval_xcallable
&& argc
> 0);
2606 return method
->location
.xm_worker
->invoke (argv
[0], argv
+ 1, argc
- 1);
2609 /* Extract a value as a C number (either long or double).
2610 Knows how to convert fixed values to double, or
2611 floating values to long.
2612 Does not deallocate the value. */
2615 value_as_long (struct value
*val
)
2617 /* This coerces arrays and functions, which is necessary (e.g.
2618 in disassemble_command). It also dereferences references, which
2619 I suspect is the most logical thing to do. */
2620 val
= coerce_array (val
);
2621 return unpack_long (value_type (val
), value_contents (val
));
2624 /* Extract a value as a C pointer. Does not deallocate the value.
2625 Note that val's type may not actually be a pointer; value_as_long
2626 handles all the cases. */
2628 value_as_address (struct value
*val
)
2630 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2632 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2633 whether we want this to be true eventually. */
2635 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2636 non-address (e.g. argument to "signal", "info break", etc.), or
2637 for pointers to char, in which the low bits *are* significant. */
2638 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2641 /* There are several targets (IA-64, PowerPC, and others) which
2642 don't represent pointers to functions as simply the address of
2643 the function's entry point. For example, on the IA-64, a
2644 function pointer points to a two-word descriptor, generated by
2645 the linker, which contains the function's entry point, and the
2646 value the IA-64 "global pointer" register should have --- to
2647 support position-independent code. The linker generates
2648 descriptors only for those functions whose addresses are taken.
2650 On such targets, it's difficult for GDB to convert an arbitrary
2651 function address into a function pointer; it has to either find
2652 an existing descriptor for that function, or call malloc and
2653 build its own. On some targets, it is impossible for GDB to
2654 build a descriptor at all: the descriptor must contain a jump
2655 instruction; data memory cannot be executed; and code memory
2658 Upon entry to this function, if VAL is a value of type `function'
2659 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2660 value_address (val) is the address of the function. This is what
2661 you'll get if you evaluate an expression like `main'. The call
2662 to COERCE_ARRAY below actually does all the usual unary
2663 conversions, which includes converting values of type `function'
2664 to `pointer to function'. This is the challenging conversion
2665 discussed above. Then, `unpack_long' will convert that pointer
2666 back into an address.
2668 So, suppose the user types `disassemble foo' on an architecture
2669 with a strange function pointer representation, on which GDB
2670 cannot build its own descriptors, and suppose further that `foo'
2671 has no linker-built descriptor. The address->pointer conversion
2672 will signal an error and prevent the command from running, even
2673 though the next step would have been to convert the pointer
2674 directly back into the same address.
2676 The following shortcut avoids this whole mess. If VAL is a
2677 function, just return its address directly. */
2678 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2679 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2680 return value_address (val
);
2682 val
= coerce_array (val
);
2684 /* Some architectures (e.g. Harvard), map instruction and data
2685 addresses onto a single large unified address space. For
2686 instance: An architecture may consider a large integer in the
2687 range 0x10000000 .. 0x1000ffff to already represent a data
2688 addresses (hence not need a pointer to address conversion) while
2689 a small integer would still need to be converted integer to
2690 pointer to address. Just assume such architectures handle all
2691 integer conversions in a single function. */
2695 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2696 must admonish GDB hackers to make sure its behavior matches the
2697 compiler's, whenever possible.
2699 In general, I think GDB should evaluate expressions the same way
2700 the compiler does. When the user copies an expression out of
2701 their source code and hands it to a `print' command, they should
2702 get the same value the compiler would have computed. Any
2703 deviation from this rule can cause major confusion and annoyance,
2704 and needs to be justified carefully. In other words, GDB doesn't
2705 really have the freedom to do these conversions in clever and
2708 AndrewC pointed out that users aren't complaining about how GDB
2709 casts integers to pointers; they are complaining that they can't
2710 take an address from a disassembly listing and give it to `x/i'.
2711 This is certainly important.
2713 Adding an architecture method like integer_to_address() certainly
2714 makes it possible for GDB to "get it right" in all circumstances
2715 --- the target has complete control over how things get done, so
2716 people can Do The Right Thing for their target without breaking
2717 anyone else. The standard doesn't specify how integers get
2718 converted to pointers; usually, the ABI doesn't either, but
2719 ABI-specific code is a more reasonable place to handle it. */
2721 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2722 && !TYPE_IS_REFERENCE (value_type (val
))
2723 && gdbarch_integer_to_address_p (gdbarch
))
2724 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2725 value_contents (val
));
2727 return unpack_long (value_type (val
), value_contents (val
));
2731 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2732 as a long, or as a double, assuming the raw data is described
2733 by type TYPE. Knows how to convert different sizes of values
2734 and can convert between fixed and floating point. We don't assume
2735 any alignment for the raw data. Return value is in host byte order.
2737 If you want functions and arrays to be coerced to pointers, and
2738 references to be dereferenced, call value_as_long() instead.
2740 C++: It is assumed that the front-end has taken care of
2741 all matters concerning pointers to members. A pointer
2742 to member which reaches here is considered to be equivalent
2743 to an INT (or some size). After all, it is only an offset. */
2746 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2748 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2749 enum type_code code
= TYPE_CODE (type
);
2750 int len
= TYPE_LENGTH (type
);
2751 int nosign
= TYPE_UNSIGNED (type
);
2755 case TYPE_CODE_TYPEDEF
:
2756 return unpack_long (check_typedef (type
), valaddr
);
2757 case TYPE_CODE_ENUM
:
2758 case TYPE_CODE_FLAGS
:
2759 case TYPE_CODE_BOOL
:
2761 case TYPE_CODE_CHAR
:
2762 case TYPE_CODE_RANGE
:
2763 case TYPE_CODE_MEMBERPTR
:
2765 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2767 return extract_signed_integer (valaddr
, len
, byte_order
);
2770 case TYPE_CODE_DECFLOAT
:
2771 return target_float_to_longest (valaddr
, type
);
2775 case TYPE_CODE_RVALUE_REF
:
2776 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2777 whether we want this to be true eventually. */
2778 return extract_typed_address (valaddr
, type
);
2781 error (_("Value can't be converted to integer."));
2783 return 0; /* Placate lint. */
2786 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2787 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2788 We don't assume any alignment for the raw data. Return value is in
2791 If you want functions and arrays to be coerced to pointers, and
2792 references to be dereferenced, call value_as_address() instead.
2794 C++: It is assumed that the front-end has taken care of
2795 all matters concerning pointers to members. A pointer
2796 to member which reaches here is considered to be equivalent
2797 to an INT (or some size). After all, it is only an offset. */
2800 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2802 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2803 whether we want this to be true eventually. */
2804 return unpack_long (type
, valaddr
);
2808 is_floating_value (struct value
*val
)
2810 struct type
*type
= check_typedef (value_type (val
));
2812 if (is_floating_type (type
))
2814 if (!target_float_is_valid (value_contents (val
), type
))
2815 error (_("Invalid floating value found in program."));
2823 /* Get the value of the FIELDNO'th field (which must be static) of
2827 value_static_field (struct type
*type
, int fieldno
)
2829 struct value
*retval
;
2831 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2833 case FIELD_LOC_KIND_PHYSADDR
:
2834 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2835 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2837 case FIELD_LOC_KIND_PHYSNAME
:
2839 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2840 /* TYPE_FIELD_NAME (type, fieldno); */
2841 struct block_symbol sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2843 if (sym
.symbol
== NULL
)
2845 /* With some compilers, e.g. HP aCC, static data members are
2846 reported as non-debuggable symbols. */
2847 struct bound_minimal_symbol msym
2848 = lookup_minimal_symbol (phys_name
, NULL
, NULL
);
2849 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2852 retval
= allocate_optimized_out_value (field_type
);
2854 retval
= value_at_lazy (field_type
, BMSYMBOL_VALUE_ADDRESS (msym
));
2857 retval
= value_of_variable (sym
.symbol
, sym
.block
);
2861 gdb_assert_not_reached ("unexpected field location kind");
2867 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2868 You have to be careful here, since the size of the data area for the value
2869 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2870 than the old enclosing type, you have to allocate more space for the
2874 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2876 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2878 check_type_length_before_alloc (new_encl_type
);
2880 = (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2883 val
->enclosing_type
= new_encl_type
;
2886 /* Given a value ARG1 (offset by OFFSET bytes)
2887 of a struct or union type ARG_TYPE,
2888 extract and return the value of one of its (non-static) fields.
2889 FIELDNO says which field. */
2892 value_primitive_field (struct value
*arg1
, LONGEST offset
,
2893 int fieldno
, struct type
*arg_type
)
2897 struct gdbarch
*arch
= get_value_arch (arg1
);
2898 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
2900 arg_type
= check_typedef (arg_type
);
2901 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2903 /* Call check_typedef on our type to make sure that, if TYPE
2904 is a TYPE_CODE_TYPEDEF, its length is set to the length
2905 of the target type instead of zero. However, we do not
2906 replace the typedef type by the target type, because we want
2907 to keep the typedef in order to be able to print the type
2908 description correctly. */
2909 check_typedef (type
);
2911 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2913 /* Handle packed fields.
2915 Create a new value for the bitfield, with bitpos and bitsize
2916 set. If possible, arrange offset and bitpos so that we can
2917 do a single aligned read of the size of the containing type.
2918 Otherwise, adjust offset to the byte containing the first
2919 bit. Assume that the address, offset, and embedded offset
2920 are sufficiently aligned. */
2922 LONGEST bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2923 LONGEST container_bitsize
= TYPE_LENGTH (type
) * 8;
2925 v
= allocate_value_lazy (type
);
2926 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2927 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2928 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2929 v
->bitpos
= bitpos
% container_bitsize
;
2931 v
->bitpos
= bitpos
% 8;
2932 v
->offset
= (value_embedded_offset (arg1
)
2934 + (bitpos
- v
->bitpos
) / 8);
2935 set_value_parent (v
, arg1
);
2936 if (!value_lazy (arg1
))
2937 value_fetch_lazy (v
);
2939 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2941 /* This field is actually a base subobject, so preserve the
2942 entire object's contents for later references to virtual
2946 /* Lazy register values with offsets are not supported. */
2947 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2948 value_fetch_lazy (arg1
);
2950 /* We special case virtual inheritance here because this
2951 requires access to the contents, which we would rather avoid
2952 for references to ordinary fields of unavailable values. */
2953 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2954 boffset
= baseclass_offset (arg_type
, fieldno
,
2955 value_contents (arg1
),
2956 value_embedded_offset (arg1
),
2957 value_address (arg1
),
2960 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2962 if (value_lazy (arg1
))
2963 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2966 v
= allocate_value (value_enclosing_type (arg1
));
2967 value_contents_copy_raw (v
, 0, arg1
, 0,
2968 TYPE_LENGTH (value_enclosing_type (arg1
)));
2971 v
->offset
= value_offset (arg1
);
2972 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2974 else if (NULL
!= TYPE_DATA_LOCATION (type
))
2976 /* Field is a dynamic data member. */
2978 gdb_assert (0 == offset
);
2979 /* We expect an already resolved data location. */
2980 gdb_assert (PROP_CONST
== TYPE_DATA_LOCATION_KIND (type
));
2981 /* For dynamic data types defer memory allocation
2982 until we actual access the value. */
2983 v
= allocate_value_lazy (type
);
2987 /* Plain old data member */
2988 offset
+= (TYPE_FIELD_BITPOS (arg_type
, fieldno
)
2989 / (HOST_CHAR_BIT
* unit_size
));
2991 /* Lazy register values with offsets are not supported. */
2992 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2993 value_fetch_lazy (arg1
);
2995 if (value_lazy (arg1
))
2996 v
= allocate_value_lazy (type
);
2999 v
= allocate_value (type
);
3000 value_contents_copy_raw (v
, value_embedded_offset (v
),
3001 arg1
, value_embedded_offset (arg1
) + offset
,
3002 type_length_units (type
));
3004 v
->offset
= (value_offset (arg1
) + offset
3005 + value_embedded_offset (arg1
));
3007 set_value_component_location (v
, arg1
);
3011 /* Given a value ARG1 of a struct or union type,
3012 extract and return the value of one of its (non-static) fields.
3013 FIELDNO says which field. */
3016 value_field (struct value
*arg1
, int fieldno
)
3018 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
3021 /* Return a non-virtual function as a value.
3022 F is the list of member functions which contains the desired method.
3023 J is an index into F which provides the desired method.
3025 We only use the symbol for its address, so be happy with either a
3026 full symbol or a minimal symbol. */
3029 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
3030 int j
, struct type
*type
,
3034 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
3035 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
3037 struct bound_minimal_symbol msym
;
3039 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0).symbol
;
3042 memset (&msym
, 0, sizeof (msym
));
3046 gdb_assert (sym
== NULL
);
3047 msym
= lookup_bound_minimal_symbol (physname
);
3048 if (msym
.minsym
== NULL
)
3052 v
= allocate_value (ftype
);
3053 VALUE_LVAL (v
) = lval_memory
;
3056 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
3060 /* The minimal symbol might point to a function descriptor;
3061 resolve it to the actual code address instead. */
3062 struct objfile
*objfile
= msym
.objfile
;
3063 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3065 set_value_address (v
,
3066 gdbarch_convert_from_func_ptr_addr
3067 (gdbarch
, BMSYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
3072 if (type
!= value_type (*arg1p
))
3073 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
3074 value_addr (*arg1p
)));
3076 /* Move the `this' pointer according to the offset.
3077 VALUE_OFFSET (*arg1p) += offset; */
3085 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
3086 VALADDR, and store the result in *RESULT.
3087 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
3088 BITSIZE is zero, then the length is taken from FIELD_TYPE.
3090 Extracting bits depends on endianness of the machine. Compute the
3091 number of least significant bits to discard. For big endian machines,
3092 we compute the total number of bits in the anonymous object, subtract
3093 off the bit count from the MSB of the object to the MSB of the
3094 bitfield, then the size of the bitfield, which leaves the LSB discard
3095 count. For little endian machines, the discard count is simply the
3096 number of bits from the LSB of the anonymous object to the LSB of the
3099 If the field is signed, we also do sign extension. */
3102 unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
3103 LONGEST bitpos
, LONGEST bitsize
)
3105 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3110 LONGEST read_offset
;
3112 /* Read the minimum number of bytes required; there may not be
3113 enough bytes to read an entire ULONGEST. */
3114 field_type
= check_typedef (field_type
);
3116 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
3119 bytes_read
= TYPE_LENGTH (field_type
);
3120 bitsize
= 8 * bytes_read
;
3123 read_offset
= bitpos
/ 8;
3125 val
= extract_unsigned_integer (valaddr
+ read_offset
,
3126 bytes_read
, byte_order
);
3128 /* Extract bits. See comment above. */
3130 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
3131 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
3133 lsbcount
= (bitpos
% 8);
3136 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
3137 If the field is signed, and is negative, then sign extend. */
3139 if (bitsize
< 8 * (int) sizeof (val
))
3141 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
3143 if (!TYPE_UNSIGNED (field_type
))
3145 if (val
& (valmask
^ (valmask
>> 1)))
3155 /* Unpack a field FIELDNO of the specified TYPE, from the object at
3156 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
3157 ORIGINAL_VALUE, which must not be NULL. See
3158 unpack_value_bits_as_long for more details. */
3161 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
3162 LONGEST embedded_offset
, int fieldno
,
3163 const struct value
*val
, LONGEST
*result
)
3165 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3166 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3167 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3170 gdb_assert (val
!= NULL
);
3172 bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3173 if (value_bits_any_optimized_out (val
, bit_offset
, bitsize
)
3174 || !value_bits_available (val
, bit_offset
, bitsize
))
3177 *result
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3182 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
3183 object at VALADDR. See unpack_bits_as_long for more details. */
3186 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
3188 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3189 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3190 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
3192 return unpack_bits_as_long (field_type
, valaddr
, bitpos
, bitsize
);
3195 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object at
3196 VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and store
3197 the contents in DEST_VAL, zero or sign extending if the type of
3198 DEST_VAL is wider than BITSIZE. VALADDR points to the contents of
3199 VAL. If the VAL's contents required to extract the bitfield from
3200 are unavailable/optimized out, DEST_VAL is correspondingly
3201 marked unavailable/optimized out. */
3204 unpack_value_bitfield (struct value
*dest_val
,
3205 LONGEST bitpos
, LONGEST bitsize
,
3206 const gdb_byte
*valaddr
, LONGEST embedded_offset
,
3207 const struct value
*val
)
3209 enum bfd_endian byte_order
;
3212 struct type
*field_type
= value_type (dest_val
);
3214 byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
3216 /* First, unpack and sign extend the bitfield as if it was wholly
3217 valid. Optimized out/unavailable bits are read as zero, but
3218 that's OK, as they'll end up marked below. If the VAL is
3219 wholly-invalid we may have skipped allocating its contents,
3220 though. See allocate_optimized_out_value. */
3221 if (valaddr
!= NULL
)
3225 num
= unpack_bits_as_long (field_type
, valaddr
+ embedded_offset
,
3227 store_signed_integer (value_contents_raw (dest_val
),
3228 TYPE_LENGTH (field_type
), byte_order
, num
);
3231 /* Now copy the optimized out / unavailability ranges to the right
3233 src_bit_offset
= embedded_offset
* TARGET_CHAR_BIT
+ bitpos
;
3234 if (byte_order
== BFD_ENDIAN_BIG
)
3235 dst_bit_offset
= TYPE_LENGTH (field_type
) * TARGET_CHAR_BIT
- bitsize
;
3238 value_ranges_copy_adjusted (dest_val
, dst_bit_offset
,
3239 val
, src_bit_offset
, bitsize
);
3242 /* Return a new value with type TYPE, which is FIELDNO field of the
3243 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
3244 of VAL. If the VAL's contents required to extract the bitfield
3245 from are unavailable/optimized out, the new value is
3246 correspondingly marked unavailable/optimized out. */
3249 value_field_bitfield (struct type
*type
, int fieldno
,
3250 const gdb_byte
*valaddr
,
3251 LONGEST embedded_offset
, const struct value
*val
)
3253 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
3254 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
3255 struct value
*res_val
= allocate_value (TYPE_FIELD_TYPE (type
, fieldno
));
3257 unpack_value_bitfield (res_val
, bitpos
, bitsize
,
3258 valaddr
, embedded_offset
, val
);
3263 /* Modify the value of a bitfield. ADDR points to a block of memory in
3264 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
3265 is the desired value of the field, in host byte order. BITPOS and BITSIZE
3266 indicate which bits (in target bit order) comprise the bitfield.
3267 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
3268 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
3271 modify_field (struct type
*type
, gdb_byte
*addr
,
3272 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
)
3274 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3276 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3279 /* Normalize BITPOS. */
3283 /* If a negative fieldval fits in the field in question, chop
3284 off the sign extension bits. */
3285 if ((~fieldval
& ~(mask
>> 1)) == 0)
3288 /* Warn if value is too big to fit in the field in question. */
3289 if (0 != (fieldval
& ~mask
))
3291 /* FIXME: would like to include fieldval in the message, but
3292 we don't have a sprintf_longest. */
3293 warning (_("Value does not fit in %s bits."), plongest (bitsize
));
3295 /* Truncate it, otherwise adjoining fields may be corrupted. */
3299 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3300 false valgrind reports. */
3302 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3303 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3305 /* Shifting for bit field depends on endianness of the target machine. */
3306 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3307 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3309 oword
&= ~(mask
<< bitpos
);
3310 oword
|= fieldval
<< bitpos
;
3312 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3315 /* Pack NUM into BUF using a target format of TYPE. */
3318 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3320 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3323 type
= check_typedef (type
);
3324 len
= TYPE_LENGTH (type
);
3326 switch (TYPE_CODE (type
))
3329 case TYPE_CODE_CHAR
:
3330 case TYPE_CODE_ENUM
:
3331 case TYPE_CODE_FLAGS
:
3332 case TYPE_CODE_BOOL
:
3333 case TYPE_CODE_RANGE
:
3334 case TYPE_CODE_MEMBERPTR
:
3335 store_signed_integer (buf
, len
, byte_order
, num
);
3339 case TYPE_CODE_RVALUE_REF
:
3341 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3345 case TYPE_CODE_DECFLOAT
:
3346 target_float_from_longest (buf
, type
, num
);
3350 error (_("Unexpected type (%d) encountered for integer constant."),
3356 /* Pack NUM into BUF using a target format of TYPE. */
3359 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3362 enum bfd_endian byte_order
;
3364 type
= check_typedef (type
);
3365 len
= TYPE_LENGTH (type
);
3366 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3368 switch (TYPE_CODE (type
))
3371 case TYPE_CODE_CHAR
:
3372 case TYPE_CODE_ENUM
:
3373 case TYPE_CODE_FLAGS
:
3374 case TYPE_CODE_BOOL
:
3375 case TYPE_CODE_RANGE
:
3376 case TYPE_CODE_MEMBERPTR
:
3377 store_unsigned_integer (buf
, len
, byte_order
, num
);
3381 case TYPE_CODE_RVALUE_REF
:
3383 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3387 case TYPE_CODE_DECFLOAT
:
3388 target_float_from_ulongest (buf
, type
, num
);
3392 error (_("Unexpected type (%d) encountered "
3393 "for unsigned integer constant."),
3399 /* Convert C numbers into newly allocated values. */
3402 value_from_longest (struct type
*type
, LONGEST num
)
3404 struct value
*val
= allocate_value (type
);
3406 pack_long (value_contents_raw (val
), type
, num
);
3411 /* Convert C unsigned numbers into newly allocated values. */
3414 value_from_ulongest (struct type
*type
, ULONGEST num
)
3416 struct value
*val
= allocate_value (type
);
3418 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3424 /* Create a value representing a pointer of type TYPE to the address
3428 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3430 struct value
*val
= allocate_value (type
);
3432 store_typed_address (value_contents_raw (val
),
3433 check_typedef (type
), addr
);
3438 /* Create a value of type TYPE whose contents come from VALADDR, if it
3439 is non-null, and whose memory address (in the inferior) is
3440 ADDRESS. The type of the created value may differ from the passed
3441 type TYPE. Make sure to retrieve values new type after this call.
3442 Note that TYPE is not passed through resolve_dynamic_type; this is
3443 a special API intended for use only by Ada. */
3446 value_from_contents_and_address_unresolved (struct type
*type
,
3447 const gdb_byte
*valaddr
,
3452 if (valaddr
== NULL
)
3453 v
= allocate_value_lazy (type
);
3455 v
= value_from_contents (type
, valaddr
);
3456 VALUE_LVAL (v
) = lval_memory
;
3457 set_value_address (v
, address
);
3461 /* Create a value of type TYPE whose contents come from VALADDR, if it
3462 is non-null, and whose memory address (in the inferior) is
3463 ADDRESS. The type of the created value may differ from the passed
3464 type TYPE. Make sure to retrieve values new type after this call. */
3467 value_from_contents_and_address (struct type
*type
,
3468 const gdb_byte
*valaddr
,
3471 struct type
*resolved_type
= resolve_dynamic_type (type
, valaddr
, address
);
3472 struct type
*resolved_type_no_typedef
= check_typedef (resolved_type
);
3475 if (valaddr
== NULL
)
3476 v
= allocate_value_lazy (resolved_type
);
3478 v
= value_from_contents (resolved_type
, valaddr
);
3479 if (TYPE_DATA_LOCATION (resolved_type_no_typedef
) != NULL
3480 && TYPE_DATA_LOCATION_KIND (resolved_type_no_typedef
) == PROP_CONST
)
3481 address
= TYPE_DATA_LOCATION_ADDR (resolved_type_no_typedef
);
3482 VALUE_LVAL (v
) = lval_memory
;
3483 set_value_address (v
, address
);
3487 /* Create a value of type TYPE holding the contents CONTENTS.
3488 The new value is `not_lval'. */
3491 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3493 struct value
*result
;
3495 result
= allocate_value (type
);
3496 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3500 /* Extract a value from the history file. Input will be of the form
3501 $digits or $$digits. See block comment above 'write_dollar_variable'
3505 value_from_history_ref (const char *h
, const char **endp
)
3517 /* Find length of numeral string. */
3518 for (; isdigit (h
[len
]); len
++)
3521 /* Make sure numeral string is not part of an identifier. */
3522 if (h
[len
] == '_' || isalpha (h
[len
]))
3525 /* Now collect the index value. */
3530 /* For some bizarre reason, "$$" is equivalent to "$$1",
3531 rather than to "$$0" as it ought to be! */
3539 index
= -strtol (&h
[2], &local_end
, 10);
3547 /* "$" is equivalent to "$0". */
3555 index
= strtol (&h
[1], &local_end
, 10);
3560 return access_value_history (index
);
3563 /* Get the component value (offset by OFFSET bytes) of a struct or
3564 union WHOLE. Component's type is TYPE. */
3567 value_from_component (struct value
*whole
, struct type
*type
, LONGEST offset
)
3571 if (VALUE_LVAL (whole
) == lval_memory
&& value_lazy (whole
))
3572 v
= allocate_value_lazy (type
);
3575 v
= allocate_value (type
);
3576 value_contents_copy (v
, value_embedded_offset (v
),
3577 whole
, value_embedded_offset (whole
) + offset
,
3578 type_length_units (type
));
3580 v
->offset
= value_offset (whole
) + offset
+ value_embedded_offset (whole
);
3581 set_value_component_location (v
, whole
);
3587 coerce_ref_if_computed (const struct value
*arg
)
3589 const struct lval_funcs
*funcs
;
3591 if (!TYPE_IS_REFERENCE (check_typedef (value_type (arg
))))
3594 if (value_lval_const (arg
) != lval_computed
)
3597 funcs
= value_computed_funcs (arg
);
3598 if (funcs
->coerce_ref
== NULL
)
3601 return funcs
->coerce_ref (arg
);
3604 /* Look at value.h for description. */
3607 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3608 const struct type
*original_type
,
3609 const struct value
*original_value
)
3611 /* Re-adjust type. */
3612 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3614 /* Add embedding info. */
3615 set_value_enclosing_type (value
, enc_type
);
3616 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3618 /* We may be pointing to an object of some derived type. */
3619 return value_full_object (value
, NULL
, 0, 0, 0);
3623 coerce_ref (struct value
*arg
)
3625 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3626 struct value
*retval
;
3627 struct type
*enc_type
;
3629 retval
= coerce_ref_if_computed (arg
);
3633 if (!TYPE_IS_REFERENCE (value_type_arg_tmp
))
3636 enc_type
= check_typedef (value_enclosing_type (arg
));
3637 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3639 retval
= value_at_lazy (enc_type
,
3640 unpack_pointer (value_type (arg
),
3641 value_contents (arg
)));
3642 enc_type
= value_type (retval
);
3643 return readjust_indirect_value_type (retval
, enc_type
,
3644 value_type_arg_tmp
, arg
);
3648 coerce_array (struct value
*arg
)
3652 arg
= coerce_ref (arg
);
3653 type
= check_typedef (value_type (arg
));
3655 switch (TYPE_CODE (type
))
3657 case TYPE_CODE_ARRAY
:
3658 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3659 arg
= value_coerce_array (arg
);
3661 case TYPE_CODE_FUNC
:
3662 arg
= value_coerce_function (arg
);
3669 /* Return the return value convention that will be used for the
3672 enum return_value_convention
3673 struct_return_convention (struct gdbarch
*gdbarch
,
3674 struct value
*function
, struct type
*value_type
)
3676 enum type_code code
= TYPE_CODE (value_type
);
3678 if (code
== TYPE_CODE_ERROR
)
3679 error (_("Function return type unknown."));
3681 /* Probe the architecture for the return-value convention. */
3682 return gdbarch_return_value (gdbarch
, function
, value_type
,
3686 /* Return true if the function returning the specified type is using
3687 the convention of returning structures in memory (passing in the
3688 address as a hidden first parameter). */
3691 using_struct_return (struct gdbarch
*gdbarch
,
3692 struct value
*function
, struct type
*value_type
)
3694 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3695 /* A void return value is never in memory. See also corresponding
3696 code in "print_return_value". */
3699 return (struct_return_convention (gdbarch
, function
, value_type
)
3700 != RETURN_VALUE_REGISTER_CONVENTION
);
3703 /* Set the initialized field in a value struct. */
3706 set_value_initialized (struct value
*val
, int status
)
3708 val
->initialized
= status
;
3711 /* Return the initialized field in a value struct. */
3714 value_initialized (const struct value
*val
)
3716 return val
->initialized
;
3719 /* Load the actual content of a lazy value. Fetch the data from the
3720 user's process and clear the lazy flag to indicate that the data in
3721 the buffer is valid.
3723 If the value is zero-length, we avoid calling read_memory, which
3724 would abort. We mark the value as fetched anyway -- all 0 bytes of
3728 value_fetch_lazy (struct value
*val
)
3730 gdb_assert (value_lazy (val
));
3731 allocate_value_contents (val
);
3732 /* A value is either lazy, or fully fetched. The
3733 availability/validity is only established as we try to fetch a
3735 gdb_assert (val
->optimized_out
.empty ());
3736 gdb_assert (val
->unavailable
.empty ());
3737 if (value_bitsize (val
))
3739 /* To read a lazy bitfield, read the entire enclosing value. This
3740 prevents reading the same block of (possibly volatile) memory once
3741 per bitfield. It would be even better to read only the containing
3742 word, but we have no way to record that just specific bits of a
3743 value have been fetched. */
3744 struct type
*type
= check_typedef (value_type (val
));
3745 struct value
*parent
= value_parent (val
);
3747 if (value_lazy (parent
))
3748 value_fetch_lazy (parent
);
3750 unpack_value_bitfield (val
,
3751 value_bitpos (val
), value_bitsize (val
),
3752 value_contents_for_printing (parent
),
3753 value_offset (val
), parent
);
3755 else if (VALUE_LVAL (val
) == lval_memory
)
3757 CORE_ADDR addr
= value_address (val
);
3758 struct type
*type
= check_typedef (value_enclosing_type (val
));
3760 if (TYPE_LENGTH (type
))
3761 read_value_memory (val
, 0, value_stack (val
),
3762 addr
, value_contents_all_raw (val
),
3763 type_length_units (type
));
3765 else if (VALUE_LVAL (val
) == lval_register
)
3767 struct frame_info
*next_frame
;
3769 struct type
*type
= check_typedef (value_type (val
));
3770 struct value
*new_val
= val
, *mark
= value_mark ();
3772 /* Offsets are not supported here; lazy register values must
3773 refer to the entire register. */
3774 gdb_assert (value_offset (val
) == 0);
3776 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3778 struct frame_id next_frame_id
= VALUE_NEXT_FRAME_ID (new_val
);
3780 next_frame
= frame_find_by_id (next_frame_id
);
3781 regnum
= VALUE_REGNUM (new_val
);
3783 gdb_assert (next_frame
!= NULL
);
3785 /* Convertible register routines are used for multi-register
3786 values and for interpretation in different types
3787 (e.g. float or int from a double register). Lazy
3788 register values should have the register's natural type,
3789 so they do not apply. */
3790 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (next_frame
),
3793 /* FRAME was obtained, above, via VALUE_NEXT_FRAME_ID.
3794 Since a "->next" operation was performed when setting
3795 this field, we do not need to perform a "next" operation
3796 again when unwinding the register. That's why
3797 frame_unwind_register_value() is called here instead of
3798 get_frame_register_value(). */
3799 new_val
= frame_unwind_register_value (next_frame
, regnum
);
3801 /* If we get another lazy lval_register value, it means the
3802 register is found by reading it from NEXT_FRAME's next frame.
3803 frame_unwind_register_value should never return a value with
3804 the frame id pointing to NEXT_FRAME. If it does, it means we
3805 either have two consecutive frames with the same frame id
3806 in the frame chain, or some code is trying to unwind
3807 behind get_prev_frame's back (e.g., a frame unwind
3808 sniffer trying to unwind), bypassing its validations. In
3809 any case, it should always be an internal error to end up
3810 in this situation. */
3811 if (VALUE_LVAL (new_val
) == lval_register
3812 && value_lazy (new_val
)
3813 && frame_id_eq (VALUE_NEXT_FRAME_ID (new_val
), next_frame_id
))
3814 internal_error (__FILE__
, __LINE__
,
3815 _("infinite loop while fetching a register"));
3818 /* If it's still lazy (for instance, a saved register on the
3819 stack), fetch it. */
3820 if (value_lazy (new_val
))
3821 value_fetch_lazy (new_val
);
3823 /* Copy the contents and the unavailability/optimized-out
3824 meta-data from NEW_VAL to VAL. */
3825 set_value_lazy (val
, 0);
3826 value_contents_copy (val
, value_embedded_offset (val
),
3827 new_val
, value_embedded_offset (new_val
),
3828 type_length_units (type
));
3832 struct gdbarch
*gdbarch
;
3833 struct frame_info
*frame
;
3834 /* VALUE_FRAME_ID is used here, instead of VALUE_NEXT_FRAME_ID,
3835 so that the frame level will be shown correctly. */
3836 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3837 regnum
= VALUE_REGNUM (val
);
3838 gdbarch
= get_frame_arch (frame
);
3840 fprintf_unfiltered (gdb_stdlog
,
3841 "{ value_fetch_lazy "
3842 "(frame=%d,regnum=%d(%s),...) ",
3843 frame_relative_level (frame
), regnum
,
3844 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3846 fprintf_unfiltered (gdb_stdlog
, "->");
3847 if (value_optimized_out (new_val
))
3849 fprintf_unfiltered (gdb_stdlog
, " ");
3850 val_print_optimized_out (new_val
, gdb_stdlog
);
3855 const gdb_byte
*buf
= value_contents (new_val
);
3857 if (VALUE_LVAL (new_val
) == lval_register
)
3858 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3859 VALUE_REGNUM (new_val
));
3860 else if (VALUE_LVAL (new_val
) == lval_memory
)
3861 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3863 value_address (new_val
)));
3865 fprintf_unfiltered (gdb_stdlog
, " computed");
3867 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3868 fprintf_unfiltered (gdb_stdlog
, "[");
3869 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3870 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3871 fprintf_unfiltered (gdb_stdlog
, "]");
3874 fprintf_unfiltered (gdb_stdlog
, " }\n");
3877 /* Dispose of the intermediate values. This prevents
3878 watchpoints from trying to watch the saved frame pointer. */
3879 value_free_to_mark (mark
);
3881 else if (VALUE_LVAL (val
) == lval_computed
3882 && value_computed_funcs (val
)->read
!= NULL
)
3883 value_computed_funcs (val
)->read (val
);
3885 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3887 set_value_lazy (val
, 0);
3890 /* Implementation of the convenience function $_isvoid. */
3892 static struct value
*
3893 isvoid_internal_fn (struct gdbarch
*gdbarch
,
3894 const struct language_defn
*language
,
3895 void *cookie
, int argc
, struct value
**argv
)
3900 error (_("You must provide one argument for $_isvoid."));
3902 ret
= TYPE_CODE (value_type (argv
[0])) == TYPE_CODE_VOID
;
3904 return value_from_longest (builtin_type (gdbarch
)->builtin_int
, ret
);
3908 _initialize_values (void)
3910 add_cmd ("convenience", no_class
, show_convenience
, _("\
3911 Debugger convenience (\"$foo\") variables and functions.\n\
3912 Convenience variables are created when you assign them values;\n\
3913 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3915 A few convenience variables are given values automatically:\n\
3916 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3917 \"$__\" holds the contents of the last address examined with \"x\"."
3920 Convenience functions are defined via the Python API."
3923 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3925 add_cmd ("values", no_set_class
, show_values
, _("\
3926 Elements of value history around item number IDX (or last ten)."),
3929 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3930 Initialize a convenience variable if necessary.\n\
3931 init-if-undefined VARIABLE = EXPRESSION\n\
3932 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3933 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3934 VARIABLE is already initialized."));
3936 add_prefix_cmd ("function", no_class
, function_command
, _("\
3937 Placeholder command for showing help on convenience functions."),
3938 &functionlist
, "function ", 0, &cmdlist
);
3940 add_internal_function ("_isvoid", _("\
3941 Check whether an expression is void.\n\
3942 Usage: $_isvoid (expression)\n\
3943 Return 1 if the expression is void, zero otherwise."),
3944 isvoid_internal_fn
, NULL
);
3946 add_setshow_zuinteger_unlimited_cmd ("max-value-size",
3947 class_support
, &max_value_size
, _("\
3948 Set maximum sized value gdb will load from the inferior."), _("\
3949 Show maximum sized value gdb will load from the inferior."), _("\
3950 Use this to control the maximum size, in bytes, of a value that gdb\n\
3951 will load from the inferior. Setting this value to 'unlimited'\n\
3952 disables checking.\n\
3953 Setting this does not invalidate already allocated values, it only\n\
3954 prevents future values, larger than this size, from being allocated."),
3956 show_max_value_size
,
3957 &setlist
, &showlist
);