1 /* Definitions for values of C expressions, for GDB.
3 Copyright (C) 1986-2023 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/>. */
20 #if !defined (VALUE_H)
23 #include "frame.h" /* For struct frame_id. */
24 #include "extension.h"
25 #include "gdbsupport/gdb_ref_ptr.h"
26 #include "gmp-utils.h"
35 struct value_print_options
;
37 /* Values can be partially 'optimized out' and/or 'unavailable'.
38 These are distinct states and have different string representations
39 and related error strings.
41 'unavailable' has a specific meaning in this context. It means the
42 value exists in the program (at the machine level), but GDB has no
43 means to get to it. Such a value is normally printed as
44 <unavailable>. Examples of how to end up with an unavailable value
47 - We're inspecting a traceframe, and the memory or registers the
48 debug information says the value lives on haven't been collected.
50 - We're inspecting a core dump, the memory or registers the debug
51 information says the value lives aren't present in the dump
52 (that is, we have a partial/trimmed core dump, or we don't fully
53 understand/handle the core dump's format).
55 - We're doing live debugging, but the debug API has no means to
56 get at where the value lives in the machine, like e.g., ptrace
57 not having access to some register or register set.
59 - Any other similar scenario.
61 OTOH, "optimized out" is about what the compiler decided to generate
62 (or not generate). A chunk of a value that was optimized out does
63 not actually exist in the program. There's no way to get at it
64 short of compiling the program differently.
66 A register that has not been saved in a frame is likewise considered
67 optimized out, except not-saved registers have a different string
68 representation and related error strings. E.g., we'll print them as
69 <not-saved> instead of <optimized out>, as in:
73 (gdb) info registers rax
76 If the debug info describes a variable as being in such a register,
77 we'll still print the variable as <optimized out>. IOW, <not saved>
78 is reserved for inspecting registers at the machine level.
80 When comparing value contents, optimized out chunks, unavailable
81 chunks, and valid contents data are all considered different. See
82 value_contents_eq for more info.
85 extern bool overload_resolution
;
87 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
91 /* Lowest offset in the range. */
94 /* Length of the range. */
97 /* Returns true if THIS is strictly less than OTHER, useful for
98 searching. We keep ranges sorted by offset and coalesce
99 overlapping and contiguous ranges, so this just compares the
102 bool operator< (const range
&other
) const
104 return offset
< other
.offset
;
107 /* Returns true if THIS is equal to OTHER. */
108 bool operator== (const range
&other
) const
110 return offset
== other
.offset
&& length
== other
.length
;
114 /* A policy class to interface gdb::ref_ptr with struct value. */
116 struct value_ref_policy
118 static void incref (struct value
*ptr
);
119 static void decref (struct value
*ptr
);
122 /* A gdb:;ref_ptr pointer to a struct value. */
124 typedef gdb::ref_ptr
<struct value
, value_ref_policy
> value_ref_ptr
;
126 /* Note that the fields in this structure are arranged to save a bit
133 /* Values can only be created via "static constructors". */
134 explicit value (struct type
*type_
)
135 : m_modifiable (true),
137 m_initialized (true),
140 m_in_history (false),
142 m_enclosing_type (type_
)
146 /* Values can only be destroyed via the reference-counting
150 DISABLE_COPY_AND_ASSIGN (value
);
154 /* Allocate a lazy value for type TYPE. Its actual content is
155 "lazily" allocated too: the content field of the return value is
156 NULL; it will be allocated when it is fetched from the target. */
157 static struct value
*allocate_lazy (struct type
*type
);
159 /* Allocate a value and its contents for type TYPE. */
160 static struct value
*allocate (struct type
*type
);
162 /* Create a computed lvalue, with type TYPE, function pointers
163 FUNCS, and closure CLOSURE. */
164 static struct value
*allocate_computed (struct type
*type
,
165 const struct lval_funcs
*funcs
,
168 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
169 static struct value
*allocate_optimized_out (struct type
*type
);
171 /* Create a value of type TYPE that is zero, and return it. */
172 static struct value
*zero (struct type
*type
, enum lval_type lv
);
174 /* Return a copy of the value. It contains the same contents, for
175 the same memory address, but it's a different block of
177 struct value
*copy () const;
179 /* Type of the value. */
180 struct type
*type () const
183 /* This is being used to change the type of an existing value, that
184 code should instead be creating a new value with the changed type
185 (but possibly shared content). */
186 void deprecated_set_type (struct type
*type
)
189 /* Return the gdbarch associated with the value. */
190 struct gdbarch
*arch () const;
192 /* Only used for bitfields; number of bits contained in them. */
193 LONGEST
bitsize () const
194 { return m_bitsize
; }
196 void set_bitsize (LONGEST bit
)
199 /* Only used for bitfields; position of start of field. For
200 little-endian targets, it is the position of the LSB. For
201 big-endian targets, it is the position of the MSB. */
202 LONGEST
bitpos () const
205 void set_bitpos (LONGEST bit
)
208 /* Only used for bitfields; the containing value. This allows a
209 single read from the target when displaying multiple
211 value
*parent () const
212 { return m_parent
.get (); }
214 void set_parent (struct value
*parent
)
215 { m_parent
= value_ref_ptr::new_reference (parent
); }
217 /* Describes offset of a value within lval of a structure in bytes.
218 If lval == lval_memory, this is an offset to the address. If
219 lval == lval_register, this is a further offset from
220 location.address within the registers structure. Note also the
221 member embedded_offset below. */
222 LONGEST
offset () const
225 void set_offset (LONGEST offset
)
226 { m_offset
= offset
; }
228 /* The comment from "struct value" reads: ``Is it modifiable? Only
229 relevant if lval != not_lval.''. Shouldn't the value instead be
230 not_lval and be done with it? */
231 bool deprecated_modifiable () const
232 { return m_modifiable
; }
234 /* Set or clear the modifiable flag. */
235 void set_modifiable (bool val
)
236 { m_modifiable
= val
; }
238 LONGEST
pointed_to_offset () const
239 { return m_pointed_to_offset
; }
241 void set_pointed_to_offset (LONGEST val
)
242 { m_pointed_to_offset
= val
; }
244 LONGEST
embedded_offset () const
245 { return m_embedded_offset
; }
247 void set_embedded_offset (LONGEST val
)
248 { m_embedded_offset
= val
; }
250 /* If false, contents of this value are in the contents field. If
251 true, contents are in inferior. If the lval field is lval_memory,
252 the contents are in inferior memory at location.address plus offset.
253 The lval field may also be lval_register.
255 WARNING: This field is used by the code which handles watchpoints
256 (see breakpoint.c) to decide whether a particular value can be
257 watched by hardware watchpoints. If the lazy flag is set for some
258 member of a value chain, it is assumed that this member of the
259 chain doesn't need to be watched as part of watching the value
260 itself. This is how GDB avoids watching the entire struct or array
261 when the user wants to watch a single struct member or array
262 element. If you ever change the way lazy flag is set and reset, be
263 sure to consider this use as well! */
268 void set_lazy (bool val
)
271 /* If a value represents a C++ object, then the `type' field gives the
272 object's compile-time type. If the object actually belongs to some
273 class derived from `type', perhaps with other base classes and
274 additional members, then `type' is just a subobject of the real
275 thing, and the full object is probably larger than `type' would
278 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
279 actually determine the object's run-time type by looking at the
280 run-time type information in the vtable. When this information is
281 available, we may elect to read in the entire object, for several
284 - When printing the value, the user would probably rather see the
285 full object, not just the limited portion apparent from the
288 - If `type' has virtual base classes, then even printing `type'
289 alone may require reaching outside the `type' portion of the
290 object to wherever the virtual base class has been stored.
292 When we store the entire object, `enclosing_type' is the run-time
293 type -- the complete object -- and `embedded_offset' is the offset
294 of `type' within that larger type, in bytes. The contents()
295 method takes `embedded_offset' into account, so most GDB code
296 continues to see the `type' portion of the value, just as the
299 If `type' is a pointer to an object, then `enclosing_type' is a
300 pointer to the object's run-time type, and `pointed_to_offset' is
301 the offset in bytes from the full object to the pointed-to object
302 -- that is, the value `embedded_offset' would have if we followed
303 the pointer and fetched the complete object. (I don't really see
304 the point. Why not just determine the run-time type when you
305 indirect, and avoid the special case? The contents don't matter
306 until you indirect anyway.)
308 If we're not doing anything fancy, `enclosing_type' is equal to
309 `type', and `embedded_offset' is zero, so everything works
312 struct type
*enclosing_type () const
313 { return m_enclosing_type
; }
315 void set_enclosing_type (struct type
*new_type
);
320 void set_stack (bool val
)
323 /* If this value is lval_computed, return its lval_funcs
325 const struct lval_funcs
*computed_funcs () const;
327 /* If this value is lval_computed, return its closure. The meaning
328 of the returned value depends on the functions this value
330 void *computed_closure () const;
332 enum lval_type
lval () const
335 /* Set the 'lval' of this value. */
336 void set_lval (lval_type val
)
339 /* Set or return field indicating whether a variable is initialized or
340 not, based on debugging information supplied by the compiler.
341 true = initialized; false = uninitialized. */
342 bool initialized () const
343 { return m_initialized
; }
345 void set_initialized (bool value
)
346 { m_initialized
= value
; }
348 /* If lval == lval_memory, return the address in the inferior. If
349 lval == lval_register, return the byte offset into the registers
350 structure. Otherwise, return 0. The returned address
351 includes the offset, if any. */
352 CORE_ADDR
address () const;
354 /* Like address, except the result does not include value's
356 CORE_ADDR
raw_address () const;
358 /* Set the address of a value. */
359 void set_address (CORE_ADDR
);
361 struct internalvar
**deprecated_internalvar_hack ()
362 { return &m_location
.internalvar
; }
364 struct frame_id
*deprecated_next_frame_id_hack ();
366 int *deprecated_regnum_hack ();
368 /* contents() and contents_raw() both return the address of the gdb
369 buffer used to hold a copy of the contents of the lval.
370 contents() is used when the contents of the buffer are needed --
371 it uses fetch_lazy() to load the buffer from the process being
372 debugged if it hasn't already been loaded (contents_writeable()
373 is used when a writeable but fetched buffer is required)..
374 contents_raw() is used when data is being stored into the buffer,
375 or when it is certain that the contents of the buffer are valid.
377 Note: The contents pointer is adjusted by the offset required to
378 get to the real subobject, if the value happens to represent
379 something embedded in a larger run-time object. */
380 gdb::array_view
<gdb_byte
> contents_raw ();
382 /* Actual contents of the value. For use of this value; setting it
383 uses the stuff above. Not valid if lazy is nonzero. Target
384 byte-order. We force it to be aligned properly for any possible
385 value. Note that a value therefore extends beyond what is
387 gdb::array_view
<const gdb_byte
> contents ();
389 /* The ALL variants of the above two methods do not adjust the
390 returned pointer by the embedded_offset value. */
391 gdb::array_view
<const gdb_byte
> contents_all ();
392 gdb::array_view
<gdb_byte
> contents_all_raw ();
394 gdb::array_view
<gdb_byte
> contents_writeable ();
396 /* Like contents_all, but does not require that the returned bits be
397 valid. This should only be used in situations where you plan to
398 check the validity manually. */
399 gdb::array_view
<const gdb_byte
> contents_for_printing ();
401 /* Like contents_for_printing, but accepts a constant value pointer.
402 Unlike contents_for_printing however, the pointed value must
404 gdb::array_view
<const gdb_byte
> contents_for_printing () const;
406 /* Load the actual content of a lazy value. Fetch the data from the
407 user's process and clear the lazy flag to indicate that the data in
410 If the value is zero-length, we avoid calling read_memory, which
411 would abort. We mark the value as fetched anyway -- all 0 bytes of
415 /* Compare LENGTH bytes of this value's contents starting at OFFSET1
416 with LENGTH bytes of VAL2's contents starting at OFFSET2.
418 Note that "contents" refers to the whole value's contents
419 (value_contents_all), without any embedded offset adjustment. For
420 example, to compare a complete object value with itself, including
421 its enclosing type chunk, you'd do:
423 int len = check_typedef (val->enclosing_type ())->length ();
424 val->contents_eq (0, val, 0, len);
426 Returns true iff the set of available/valid contents match.
428 Optimized-out contents are equal to optimized-out contents, and are
429 not equal to non-optimized-out contents.
431 Unavailable contents are equal to unavailable contents, and are not
432 equal to non-unavailable contents.
434 For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
435 represent different available/valid bytes, in a value with length
439 contents: xxxxVVVVxxxxVVZZ
443 val->contents_eq(0, val, 8, 6) => true
444 val->contents_eq(0, val, 4, 4) => false
445 val->contents_eq(0, val, 8, 8) => false
446 val->contents_eq(4, val, 12, 2) => true
447 val->contents_eq(4, val, 12, 4) => true
448 val->contents_eq(3, val, 4, 4) => true
450 If 'x's represent an unavailable byte, 'o' represents an optimized
451 out byte, in a value with length 8:
458 val->contents_eq(0, val, 2, 2) => true
459 val->contents_eq(4, val, 6, 2) => true
460 val->contents_eq(0, val, 4, 4) => true
462 We only know whether a value chunk is unavailable or optimized out
463 if we've tried to read it. As this routine is used by printing
464 routines, which may be printing values in the value history, long
465 after the inferior is gone, it works with const values. Therefore,
466 this routine must not be called with lazy values. */
468 bool contents_eq (LONGEST offset1
, const struct value
*val2
, LONGEST offset2
,
469 LONGEST length
) const;
471 /* An overload of contents_eq that compares the entirety of both
473 bool contents_eq (const struct value
*val2
) const;
475 /* Given a value, determine whether the bits starting at OFFSET and
476 extending for LENGTH bits are a synthetic pointer. */
478 bool bits_synthetic_pointer (LONGEST offset
, LONGEST length
) const;
480 /* Increase this value's reference count. */
482 { ++m_reference_count
; }
484 /* Decrease this value's reference count. When the reference count
485 drops to 0, it will be freed. */
488 /* Given a value, determine whether the contents bytes starting at
489 OFFSET and extending for LENGTH bytes are available. This returns
490 true if all bytes in the given range are available, false if any
491 byte is unavailable. */
492 bool bytes_available (LONGEST offset
, ULONGEST length
) const;
494 /* Given a value, determine whether the contents bits starting at
495 OFFSET and extending for LENGTH bits are available. This returns
496 true if all bits in the given range are available, false if any
497 bit is unavailable. */
498 bool bits_available (LONGEST offset
, ULONGEST length
) const;
500 /* Like bytes_available, but return false if any byte in the
501 whole object is unavailable. */
502 bool entirely_available ();
504 /* Like entirely_available, but return false if any byte in the
505 whole object is available. */
506 bool entirely_unavailable ()
507 { return entirely_covered_by_range_vector (m_unavailable
); }
509 /* Mark this value's content bytes starting at OFFSET and extending
510 for LENGTH bytes as unavailable. */
511 void mark_bytes_unavailable (LONGEST offset
, ULONGEST length
);
513 /* Mark this value's content bits starting at OFFSET and extending
514 for LENGTH bits as unavailable. */
515 void mark_bits_unavailable (LONGEST offset
, ULONGEST length
);
517 /* If true, this is the value of a variable which does not actually
518 exist in the program, at least partially. If the value is lazy,
519 this may fetch it now. */
520 bool optimized_out ();
522 /* Given a value, return true if any of the contents bits starting at
523 OFFSET and extending for LENGTH bits is optimized out, false
525 bool bits_any_optimized_out (int bit_offset
, int bit_length
) const;
527 /* Like optimized_out, but return true iff the whole value is
529 bool entirely_optimized_out ()
531 return entirely_covered_by_range_vector (m_optimized_out
);
534 /* Mark this value's content bytes starting at OFFSET and extending
535 for LENGTH bytes as optimized out. */
536 void mark_bytes_optimized_out (int offset
, int length
);
538 /* Mark this value's content bits starting at OFFSET and extending
539 for LENGTH bits as optimized out. */
540 void mark_bits_optimized_out (LONGEST offset
, LONGEST length
);
542 /* Return a version of this that is non-lvalue. */
543 struct value
*non_lval ();
545 /* Write contents of this value at ADDR and set its lval type to be
547 void force_lval (CORE_ADDR
);
549 /* Set this values's location as appropriate for a component of
550 WHOLE --- regardless of what kind of lvalue WHOLE is. */
551 void set_component_location (const struct value
*whole
);
553 /* Build a value wrapping and representing WORKER. The value takes
554 ownership of the xmethod_worker object. */
555 static struct value
*from_xmethod (xmethod_worker_up
&&worker
);
557 /* Return the type of the result of TYPE_CODE_XMETHOD value METHOD. */
558 struct type
*result_type_of_xmethod (gdb::array_view
<value
*> argv
);
560 /* Call the xmethod corresponding to the TYPE_CODE_XMETHOD value
562 struct value
*call_xmethod (gdb::array_view
<value
*> argv
);
564 /* Update this value before discarding OBJFILE. COPIED_TYPES is
565 used to prevent cycles / duplicates. */
566 void preserve (struct objfile
*objfile
, htab_t copied_types
);
568 /* Unpack a bitfield of BITSIZE bits found at BITPOS in the object
569 at VALADDR + EMBEDDEDOFFSET that has the type of DEST_VAL and
570 store the contents in DEST_VAL, zero or sign extending if the
571 type of DEST_VAL is wider than BITSIZE. VALADDR points to the
572 contents of this value. If this value's contents required to
573 extract the bitfield from are unavailable/optimized out, DEST_VAL
574 is correspondingly marked unavailable/optimized out. */
575 void unpack_bitfield (struct value
*dest_val
,
576 LONGEST bitpos
, LONGEST bitsize
,
577 const gdb_byte
*valaddr
, LONGEST embedded_offset
)
580 /* Copy LENGTH bytes of this value's (all) contents
581 (value_contents_all) starting at SRC_OFFSET byte, into DST
582 value's (all) contents, starting at DST_OFFSET. If unavailable
583 contents are being copied from this value, the corresponding DST
584 contents are marked unavailable accordingly. DST must not be
585 lazy. If this value is lazy, it will be fetched now.
587 It is assumed the contents of DST in the [DST_OFFSET,
588 DST_OFFSET+LENGTH) range are wholly available. */
589 void contents_copy (struct value
*dst
, LONGEST dst_offset
,
590 LONGEST src_offset
, LONGEST length
);
592 /* Given a value (offset by OFFSET bytes)
593 of a struct or union type ARG_TYPE,
594 extract and return the value of one of its (non-static) fields.
595 FIELDNO says which field. */
596 struct value
*primitive_field (LONGEST offset
, int fieldno
,
597 struct type
*arg_type
);
599 /* Create a new value by extracting it from this value. TYPE is the
600 type of the new value. BIT_OFFSET and BIT_LENGTH describe the
601 offset and field width of the value to extract from this value --
602 BIT_LENGTH may differ from TYPE's length in the case where this
603 value's type is packed.
605 When the value does come from a non-byte-aligned offset or field
606 width, it will be marked non_lval. */
607 struct value
*from_component_bitsize (struct type
*type
,
611 /* Record this value on the value history, and return its location
612 in the history. The value is removed from the value chain. */
613 int record_latest ();
617 /* Type of value; either not an lval, or one of the various
618 different possible kinds of lval. */
619 enum lval_type m_lval
= not_lval
;
621 /* Is it modifiable? Only relevant if lval != not_lval. */
622 bool m_modifiable
: 1;
624 /* If false, contents of this value are in the contents field. If
625 true, contents are in inferior. If the lval field is lval_memory,
626 the contents are in inferior memory at location.address plus offset.
627 The lval field may also be lval_register.
629 WARNING: This field is used by the code which handles watchpoints
630 (see breakpoint.c) to decide whether a particular value can be
631 watched by hardware watchpoints. If the lazy flag is set for
632 some member of a value chain, it is assumed that this member of
633 the chain doesn't need to be watched as part of watching the
634 value itself. This is how GDB avoids watching the entire struct
635 or array when the user wants to watch a single struct member or
636 array element. If you ever change the way lazy flag is set and
637 reset, be sure to consider this use as well! */
640 /* If value is a variable, is it initialized or not. */
641 bool m_initialized
: 1;
643 /* If value is from the stack. If this is set, read_stack will be
644 used instead of read_memory to enable extra caching. */
647 /* True if this is a zero value, created by 'value::zero'; false
651 /* True if this a value recorded in value history; false otherwise. */
652 bool m_in_history
: 1;
654 /* Location of value (if lval). */
657 /* If lval == lval_memory, this is the address in the inferior */
660 /*If lval == lval_register, the value is from a register. */
663 /* Register number. */
665 /* Frame ID of "next" frame to which a register value is relative.
666 If the register value is found relative to frame F, then the
667 frame id of F->next will be stored in next_frame_id. */
668 struct frame_id next_frame_id
;
671 /* Pointer to internal variable. */
672 struct internalvar
*internalvar
;
674 /* Pointer to xmethod worker. */
675 struct xmethod_worker
*xm_worker
;
677 /* If lval == lval_computed, this is a set of function pointers
678 to use to access and describe the value, and a closure pointer
682 /* Functions to call. */
683 const struct lval_funcs
*funcs
;
685 /* Closure for those functions to use. */
690 /* Describes offset of a value within lval of a structure in target
691 addressable memory units. Note also the member embedded_offset
693 LONGEST m_offset
= 0;
695 /* Only used for bitfields; number of bits contained in them. */
696 LONGEST m_bitsize
= 0;
698 /* Only used for bitfields; position of start of field. For
699 little-endian targets, it is the position of the LSB. For
700 big-endian targets, it is the position of the MSB. */
701 LONGEST m_bitpos
= 0;
703 /* The number of references to this value. When a value is created,
704 the value chain holds a reference, so REFERENCE_COUNT is 1. If
705 release_value is called, this value is removed from the chain but
706 the caller of release_value now has a reference to this value.
707 The caller must arrange for a call to value_free later. */
708 int m_reference_count
= 1;
710 /* Only used for bitfields; the containing value. This allows a
711 single read from the target when displaying multiple
713 value_ref_ptr m_parent
;
715 /* Type of the value. */
718 /* If a value represents a C++ object, then the `type' field gives
719 the object's compile-time type. If the object actually belongs
720 to some class derived from `type', perhaps with other base
721 classes and additional members, then `type' is just a subobject
722 of the real thing, and the full object is probably larger than
723 `type' would suggest.
725 If `type' is a dynamic class (i.e. one with a vtable), then GDB
726 can actually determine the object's run-time type by looking at
727 the run-time type information in the vtable. When this
728 information is available, we may elect to read in the entire
729 object, for several reasons:
731 - When printing the value, the user would probably rather see the
732 full object, not just the limited portion apparent from the
735 - If `type' has virtual base classes, then even printing `type'
736 alone may require reaching outside the `type' portion of the
737 object to wherever the virtual base class has been stored.
739 When we store the entire object, `enclosing_type' is the run-time
740 type -- the complete object -- and `embedded_offset' is the
741 offset of `type' within that larger type, in target addressable memory
742 units. The contents() method takes `embedded_offset' into account,
743 so most GDB code continues to see the `type' portion of the value, just
744 as the inferior would.
746 If `type' is a pointer to an object, then `enclosing_type' is a
747 pointer to the object's run-time type, and `pointed_to_offset' is
748 the offset in target addressable memory units from the full object
749 to the pointed-to object -- that is, the value `embedded_offset' would
750 have if we followed the pointer and fetched the complete object.
751 (I don't really see the point. Why not just determine the
752 run-time type when you indirect, and avoid the special case? The
753 contents don't matter until you indirect anyway.)
755 If we're not doing anything fancy, `enclosing_type' is equal to
756 `type', and `embedded_offset' is zero, so everything works
758 struct type
*m_enclosing_type
;
759 LONGEST m_embedded_offset
= 0;
760 LONGEST m_pointed_to_offset
= 0;
762 /* Actual contents of the value. Target byte-order.
764 May be nullptr if the value is lazy or is entirely optimized out.
765 Guaranteed to be non-nullptr otherwise. */
766 gdb::unique_xmalloc_ptr
<gdb_byte
> m_contents
;
768 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
769 rather than available, since the common and default case is for a
770 value to be available. This is filled in at value read time.
771 The unavailable ranges are tracked in bits. Note that a contents
772 bit that has been optimized out doesn't really exist in the
773 program, so it can't be marked unavailable either. */
774 std::vector
<range
> m_unavailable
;
776 /* Likewise, but for optimized out contents (a chunk of the value of
777 a variable that does not actually exist in the program). If LVAL
778 is lval_register, this is a register ($pc, $sp, etc., never a
779 program variable) that has not been saved in the frame. Not
780 saved registers and optimized-out program variables values are
781 treated pretty much the same, except not-saved registers have a
782 different string representation and related error strings. */
783 std::vector
<range
> m_optimized_out
;
785 /* This is only non-zero for values of TYPE_CODE_ARRAY and if the size of
786 the array in inferior memory is greater than max_value_size. If these
787 conditions are met then, when the value is loaded from the inferior
788 GDB will only load a portion of the array into memory, and
789 limited_length will be set to indicate the length in octets that were
790 loaded from the inferior. */
791 ULONGEST m_limited_length
= 0;
793 /* Allocate a value and its contents for type TYPE. If CHECK_SIZE
794 is true, then apply the usual max-value-size checks. */
795 static struct value
*allocate (struct type
*type
, bool check_size
);
797 /* Helper for fetch_lazy when the value is a bitfield. */
798 void fetch_lazy_bitfield ();
800 /* Helper for fetch_lazy when the value is in memory. */
801 void fetch_lazy_memory ();
803 /* Helper for fetch_lazy when the value is in a register. */
804 void fetch_lazy_register ();
806 /* Try to limit ourselves to only fetching the limited number of
807 elements. However, if this limited number of elements still
808 puts us over max_value_size, then we still refuse it and
809 return failure here, which will ultimately throw an error. */
810 bool set_limited_array_length ();
812 /* Allocate the contents of this value if it has not been allocated
813 yet. If CHECK_SIZE is true, then apply the usual max-value-size
815 void allocate_contents (bool check_size
);
817 /* Helper function for value_contents_eq. The only difference is that
818 this function is bit rather than byte based.
820 Compare LENGTH bits of this value's contents starting at OFFSET1
821 bits with LENGTH bits of VAL2's contents starting at OFFSET2
822 bits. Return true if the available bits match. */
823 bool contents_bits_eq (int offset1
, const struct value
*val2
, int offset2
,
826 void require_not_optimized_out () const;
827 void require_available () const;
829 /* Returns true if this value is entirely covered by RANGES. If the
830 value is lazy, it'll be read now. Note that RANGE is a pointer
831 to pointer because reading the value might change *RANGE. */
832 bool entirely_covered_by_range_vector (const std::vector
<range
> &ranges
);
834 /* Copy the ranges metadata from this value that overlaps
835 [SRC_BIT_OFFSET, SRC_BIT_OFFSET+BIT_LENGTH) into DST,
837 void ranges_copy_adjusted (struct value
*dst
, int dst_bit_offset
,
838 int src_bit_offset
, int bit_length
) const;
840 /* Copy LENGTH target addressable memory units of this value's (all)
841 contents (value_contents_all) starting at SRC_OFFSET, into DST
842 value's (all) contents, starting at DST_OFFSET. If unavailable
843 contents are being copied from this, the corresponding DST
844 contents are marked unavailable accordingly. Neither DST nor
845 this value may be lazy values.
847 It is assumed the contents of DST in the [DST_OFFSET,
848 DST_OFFSET+LENGTH) range are wholly available. */
849 void contents_copy_raw (struct value
*dst
, LONGEST dst_offset
,
850 LONGEST src_offset
, LONGEST length
);
852 /* A helper for value_from_component_bitsize that copies bits from
853 this value to DEST. */
854 void contents_copy_raw_bitwise (struct value
*dst
, LONGEST dst_bit_offset
,
855 LONGEST src_bit_offset
, LONGEST bit_length
);
859 value_ref_policy::incref (struct value
*ptr
)
865 value_ref_policy::decref (struct value
*ptr
)
870 /* Returns value_type or value_enclosing_type depending on
871 value_print_options.objectprint.
873 If RESOLVE_SIMPLE_TYPES is 0 the enclosing type will be resolved
874 only for pointers and references, else it will be returned
875 for all the types (e.g. structures). This option is useful
876 to prevent retrieving enclosing type for the base classes fields.
878 REAL_TYPE_FOUND is used to inform whether the real type was found
879 (or just static type was used). The NULL may be passed if it is not
882 extern struct type
*value_actual_type (struct value
*value
,
883 int resolve_simple_types
,
884 int *real_type_found
);
886 /* For lval_computed values, this structure holds functions used to
887 retrieve and set the value (or portions of the value).
889 For each function, 'V' is the 'this' pointer: an lval_funcs
890 function F may always assume that the V it receives is an
891 lval_computed value, and has F in the appropriate slot of its
892 lval_funcs structure. */
896 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
897 a problem arises in obtaining VALUE's bits, this function should
898 call 'error'. If it is NULL value_fetch_lazy on "un-lazy"
899 non-optimized-out value is an internal error. */
900 void (*read
) (struct value
*v
);
902 /* Handle an assignment TOVAL = FROMVAL by writing the value of
903 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
904 been updated. If a problem arises in doing so, this function
905 should call 'error'. If it is NULL such TOVAL assignment is an error as
906 TOVAL is not considered as an lvalue. */
907 void (*write
) (struct value
*toval
, struct value
*fromval
);
909 /* Return true if any part of V is optimized out, false otherwise.
910 This will only be called for lazy values -- if the value has been
911 fetched, then the value's optimized-out bits are consulted
913 bool (*is_optimized_out
) (struct value
*v
);
915 /* If non-NULL, this is used to implement pointer indirection for
916 this value. This method may return NULL, in which case value_ind
917 will fall back to ordinary indirection. */
918 struct value
*(*indirect
) (struct value
*value
);
920 /* If non-NULL, this is used to implement reference resolving for
921 this value. This method may return NULL, in which case coerce_ref
922 will fall back to ordinary references resolving. */
923 struct value
*(*coerce_ref
) (const struct value
*value
);
925 /* If non-NULL, this is used to determine whether the indicated bits
926 of VALUE are a synthetic pointer. */
927 bool (*check_synthetic_pointer
) (const struct value
*value
,
928 LONGEST offset
, int length
);
930 /* Return a duplicate of VALUE's closure, for use in a new value.
931 This may simply return the same closure, if VALUE's is
932 reference-counted or statically allocated.
934 This may be NULL, in which case VALUE's closure is re-used in the
936 void *(*copy_closure
) (const struct value
*v
);
938 /* Drop VALUE's reference to its closure. Maybe this frees the
939 closure; maybe this decrements a reference count; maybe the
940 closure is statically allocated and this does nothing.
942 This may be NULL, in which case no action is taken to free
944 void (*free_closure
) (struct value
*v
);
947 /* Throw an error complaining that the value has been optimized
950 extern void error_value_optimized_out (void);
952 /* Pointer to internal variable. */
953 #define VALUE_INTERNALVAR(val) (*((val)->deprecated_internalvar_hack ()))
955 /* Frame ID of "next" frame to which a register value is relative. A
956 register value is indicated by VALUE_LVAL being set to lval_register.
957 So, if the register value is found relative to frame F, then the
958 frame id of F->next will be stored in VALUE_NEXT_FRAME_ID. */
959 #define VALUE_NEXT_FRAME_ID(val) (*((val)->deprecated_next_frame_id_hack ()))
961 /* Register number if the value is from a register. */
962 #define VALUE_REGNUM(val) (*((val)->deprecated_regnum_hack ()))
964 /* Return value after lval_funcs->coerce_ref (after check_typedef). Return
965 NULL if lval_funcs->coerce_ref is not applicable for whatever reason. */
967 extern struct value
*coerce_ref_if_computed (const struct value
*arg
);
969 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
970 ENC_TYPE is the new enclosing type that should be set. ORIGINAL_TYPE and
971 ORIGINAL_VAL are the type and value of the original reference or
972 pointer. ORIGINAL_VALUE_ADDRESS is the address within VALUE, that is
973 the address that was dereferenced.
975 Note, that VALUE is modified by this function.
977 It is a common implementation for coerce_ref and value_ind. */
979 extern struct value
* readjust_indirect_value_type (struct value
*value
,
980 struct type
*enc_type
,
981 const struct type
*original_type
,
982 struct value
*original_val
,
983 CORE_ADDR original_value_address
);
985 /* Convert a REF to the object referenced. */
987 extern struct value
*coerce_ref (struct value
*value
);
989 /* If ARG is an array, convert it to a pointer.
990 If ARG is a function, convert it to a function pointer.
992 References are dereferenced. */
994 extern struct value
*coerce_array (struct value
*value
);
996 /* Read LENGTH addressable memory units starting at MEMADDR into BUFFER,
997 which is (or will be copied to) VAL's contents buffer offset by
998 BIT_OFFSET bits. Marks value contents ranges as unavailable if
999 the corresponding memory is likewise unavailable. STACK indicates
1000 whether the memory is known to be stack memory. */
1002 extern void read_value_memory (struct value
*val
, LONGEST bit_offset
,
1003 bool stack
, CORE_ADDR memaddr
,
1004 gdb_byte
*buffer
, size_t length
);
1006 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
1007 into each element of a new vector value with VECTOR_TYPE. */
1009 struct value
*value_vector_widen (struct value
*scalar_value
,
1010 struct type
*vector_type
);
1015 #include "gdbtypes.h"
1016 #include "expression.h"
1018 class frame_info_ptr
;
1021 extern int print_address_demangle (const struct value_print_options
*,
1022 struct gdbarch
*, CORE_ADDR
,
1023 struct ui_file
*, int);
1025 /* Returns true if VAL is of floating-point type. In addition,
1026 throws an error if the value is an invalid floating-point value. */
1027 extern bool is_floating_value (struct value
*val
);
1029 extern LONGEST
value_as_long (struct value
*val
);
1030 extern CORE_ADDR
value_as_address (struct value
*val
);
1032 /* Extract the value from VAL as a MPZ. This coerces arrays and
1033 handles various integer-like types as well. */
1035 extern gdb_mpz
value_as_mpz (struct value
*val
);
1037 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
1038 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
1040 extern LONGEST
unpack_field_as_long (struct type
*type
,
1041 const gdb_byte
*valaddr
,
1044 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
1045 VALADDR, and store the result in *RESULT.
1046 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
1047 BITSIZE is zero, then the length is taken from FIELD_TYPE.
1049 Extracting bits depends on endianness of the machine. Compute the
1050 number of least significant bits to discard. For big endian machines,
1051 we compute the total number of bits in the anonymous object, subtract
1052 off the bit count from the MSB of the object to the MSB of the
1053 bitfield, then the size of the bitfield, which leaves the LSB discard
1054 count. For little endian machines, the discard count is simply the
1055 number of bits from the LSB of the anonymous object to the LSB of the
1058 If the field is signed, we also do sign extension. */
1060 extern LONGEST
unpack_bits_as_long (struct type
*field_type
,
1061 const gdb_byte
*valaddr
,
1062 LONGEST bitpos
, LONGEST bitsize
);
1064 extern int unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
1065 LONGEST embedded_offset
, int fieldno
,
1066 const struct value
*val
, LONGEST
*result
);
1068 extern struct value
*value_field_bitfield (struct type
*type
, int fieldno
,
1069 const gdb_byte
*valaddr
,
1070 LONGEST embedded_offset
,
1071 const struct value
*val
);
1073 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
1075 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
1076 extern struct value
*value_from_ulongest (struct type
*type
, ULONGEST num
);
1077 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
1078 extern struct value
*value_from_host_double (struct type
*type
, double d
);
1079 extern struct value
*value_from_history_ref (const char *, const char **);
1080 extern struct value
*value_from_component (struct value
*, struct type
*,
1083 /* Convert the value V into a newly allocated value. */
1084 extern struct value
*value_from_mpz (struct type
*type
, const gdb_mpz
&v
);
1086 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
1088 /* Return a new value given a type and an address. The new value is
1089 lazy. If FRAME is given, it is used when resolving dynamic
1092 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
,
1093 frame_info_ptr frame
= nullptr);
1095 /* Like value_at, but ensures that the result is marked not_lval.
1096 This can be important if the memory is "volatile". */
1097 extern struct value
*value_at_non_lval (struct type
*type
, CORE_ADDR addr
);
1099 extern struct value
*value_from_contents_and_address_unresolved
1100 (struct type
*, const gdb_byte
*, CORE_ADDR
);
1101 extern struct value
*value_from_contents_and_address
1102 (struct type
*, const gdb_byte
*, CORE_ADDR
,
1103 frame_info_ptr frame
= nullptr);
1104 extern struct value
*value_from_contents (struct type
*, const gdb_byte
*);
1106 extern struct value
*default_value_from_register (struct gdbarch
*gdbarch
,
1109 struct frame_id frame_id
);
1111 extern void read_frame_register_value (struct value
*value
,
1112 frame_info_ptr frame
);
1114 extern struct value
*value_from_register (struct type
*type
, int regnum
,
1115 frame_info_ptr frame
);
1117 extern CORE_ADDR
address_from_register (int regnum
,
1118 frame_info_ptr frame
);
1120 extern struct value
*value_of_variable (struct symbol
*var
,
1121 const struct block
*b
);
1123 extern struct value
*address_of_variable (struct symbol
*var
,
1124 const struct block
*b
);
1126 extern struct value
*value_of_register (int regnum
, frame_info_ptr frame
);
1128 struct value
*value_of_register_lazy (frame_info_ptr frame
, int regnum
);
1130 /* Return the symbol's reading requirement. */
1132 extern enum symbol_needs_kind
symbol_read_needs (struct symbol
*);
1134 /* Return true if the symbol needs a frame. This is a wrapper for
1135 symbol_read_needs that simply checks for SYMBOL_NEEDS_FRAME. */
1137 extern int symbol_read_needs_frame (struct symbol
*);
1139 extern struct value
*read_var_value (struct symbol
*var
,
1140 const struct block
*var_block
,
1141 frame_info_ptr frame
);
1143 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
1145 extern struct value
*value_mark (void);
1147 extern void value_free_to_mark (const struct value
*mark
);
1149 /* A helper class that uses value_mark at construction time and calls
1150 value_free_to_mark in the destructor. This is used to clear out
1151 temporary values created during the lifetime of this object. */
1152 class scoped_value_mark
1156 scoped_value_mark ()
1157 : m_value (value_mark ())
1161 ~scoped_value_mark ()
1166 scoped_value_mark (scoped_value_mark
&&other
) = default;
1168 DISABLE_COPY_AND_ASSIGN (scoped_value_mark
);
1170 /* Free the values currently on the value stack. */
1171 void free_to_mark ()
1175 value_free_to_mark (m_value
);
1182 const struct value
*m_value
;
1183 bool m_freed
= false;
1186 /* Create not_lval value representing a NULL-terminated C string. The
1187 resulting value has type TYPE_CODE_ARRAY. The string passed in should
1188 not include embedded null characters.
1190 PTR points to the string data; COUNT is number of characters (does
1191 not include the NULL terminator) pointed to by PTR, each character is of
1192 type (and size of) CHAR_TYPE. */
1194 extern struct value
*value_cstring (const gdb_byte
*ptr
, ssize_t count
,
1195 struct type
*char_type
);
1197 /* Specialisation of value_cstring above. In this case PTR points to
1198 single byte characters. CHAR_TYPE must have a length of 1. */
1199 inline struct value
*value_cstring (const char *ptr
, ssize_t count
,
1200 struct type
*char_type
)
1202 gdb_assert (char_type
->length () == 1);
1203 return value_cstring ((const gdb_byte
*) ptr
, count
, char_type
);
1206 /* Create a not_lval value with type TYPE_CODE_STRING, the resulting value
1207 has type TYPE_CODE_STRING.
1209 PTR points to the string data; COUNT is number of characters pointed to
1210 by PTR, each character has the type (and size of) CHAR_TYPE.
1212 Note that string types are like array of char types with a lower bound
1213 defined by the language (usually zero or one). Also the string may
1214 contain embedded null characters. */
1216 extern struct value
*value_string (const gdb_byte
*ptr
, ssize_t count
,
1217 struct type
*char_type
);
1219 /* Specialisation of value_string above. In this case PTR points to
1220 single byte characters. CHAR_TYPE must have a length of 1. */
1221 inline struct value
*value_string (const char *ptr
, ssize_t count
,
1222 struct type
*char_type
)
1224 gdb_assert (char_type
->length () == 1);
1225 return value_string ((const gdb_byte
*) ptr
, count
, char_type
);
1228 extern struct value
*value_array (int lowbound
,
1229 gdb::array_view
<struct value
*> elemvec
);
1231 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
1233 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
1234 enum exp_opcode op
);
1236 extern struct value
*value_ptradd (struct value
*arg1
, LONGEST arg2
);
1238 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
1240 /* Return true if VAL does not live in target memory, but should in order
1241 to operate on it. Otherwise return false. */
1243 extern bool value_must_coerce_to_target (struct value
*arg1
);
1245 extern struct value
*value_coerce_to_target (struct value
*arg1
);
1247 extern struct value
*value_coerce_array (struct value
*arg1
);
1249 extern struct value
*value_coerce_function (struct value
*arg1
);
1251 extern struct value
*value_ind (struct value
*arg1
);
1253 extern struct value
*value_addr (struct value
*arg1
);
1255 extern struct value
*value_ref (struct value
*arg1
, enum type_code refcode
);
1257 extern struct value
*value_assign (struct value
*toval
,
1258 struct value
*fromval
);
1260 /* The unary + operation. */
1261 extern struct value
*value_pos (struct value
*arg1
);
1263 /* The unary - operation. */
1264 extern struct value
*value_neg (struct value
*arg1
);
1266 /* The unary ~ operation -- but note that it also implements the GCC
1267 extension, where ~ of a complex number is the complex
1269 extern struct value
*value_complement (struct value
*arg1
);
1271 extern struct value
*value_struct_elt (struct value
**argp
,
1272 gdb::optional
<gdb::array_view
<value
*>> args
,
1273 const char *name
, int *static_memfuncp
,
1276 extern struct value
*value_struct_elt_bitpos (struct value
**argp
,
1278 struct type
*field_type
,
1281 extern struct value
*value_aggregate_elt (struct type
*curtype
,
1283 struct type
*expect_type
,
1285 enum noside noside
);
1287 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
1289 enum oload_search_type
{ NON_METHOD
, METHOD
, BOTH
};
1291 extern int find_overload_match (gdb::array_view
<value
*> args
,
1293 enum oload_search_type method
,
1294 struct value
**objp
, struct symbol
*fsym
,
1295 struct value
**valp
, struct symbol
**symp
,
1296 int *staticp
, const int no_adl
,
1297 enum noside noside
);
1299 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
1301 extern struct type
*value_rtti_indirect_type (struct value
*, int *, LONGEST
*,
1304 extern struct value
*value_full_object (struct value
*, struct type
*, int,
1307 extern struct value
*value_cast_pointers (struct type
*, struct value
*, int);
1309 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
1311 extern struct value
*value_reinterpret_cast (struct type
*type
,
1314 extern struct value
*value_dynamic_cast (struct type
*type
, struct value
*arg
);
1316 extern struct value
*value_one (struct type
*type
);
1318 extern struct value
*value_repeat (struct value
*arg1
, int count
);
1320 extern struct value
*value_subscript (struct value
*array
, LONGEST index
);
1322 /* Assuming VAL is array-like (see type::is_array_like), return an
1323 array form of VAL. */
1324 extern struct value
*value_to_array (struct value
*val
);
1326 extern struct value
*value_bitstring_subscript (struct type
*type
,
1327 struct value
*bitstring
,
1330 extern struct value
*register_value_being_returned (struct type
*valtype
,
1331 struct regcache
*retbuf
);
1333 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
1336 extern enum return_value_convention
1337 struct_return_convention (struct gdbarch
*gdbarch
, struct value
*function
,
1338 struct type
*value_type
);
1340 extern int using_struct_return (struct gdbarch
*gdbarch
,
1341 struct value
*function
,
1342 struct type
*value_type
);
1344 extern value
*evaluate_var_value (enum noside noside
, const block
*blk
,
1347 extern value
*evaluate_var_msym_value (enum noside noside
,
1348 struct objfile
*objfile
,
1349 minimal_symbol
*msymbol
);
1351 namespace expr
{ class operation
; };
1352 extern void fetch_subexp_value (struct expression
*exp
,
1353 expr::operation
*op
,
1354 struct value
**valp
, struct value
**resultp
,
1355 std::vector
<value_ref_ptr
> *val_chain
,
1356 bool preserve_errors
);
1358 extern struct value
*parse_and_eval (const char *exp
, parser_flags flags
= 0);
1360 extern struct value
*parse_to_comma_and_eval (const char **expp
);
1362 extern struct type
*parse_and_eval_type (const char *p
, int length
);
1364 extern CORE_ADDR
parse_and_eval_address (const char *exp
);
1366 extern LONGEST
parse_and_eval_long (const char *exp
);
1368 extern void unop_promote (const struct language_defn
*language
,
1369 struct gdbarch
*gdbarch
,
1370 struct value
**arg1
);
1372 extern void binop_promote (const struct language_defn
*language
,
1373 struct gdbarch
*gdbarch
,
1374 struct value
**arg1
, struct value
**arg2
);
1376 extern struct value
*access_value_history (int num
);
1378 /* Return the number of items in the value history. */
1380 extern ULONGEST
value_history_count ();
1382 extern struct value
*value_of_internalvar (struct gdbarch
*gdbarch
,
1383 struct internalvar
*var
);
1385 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
1387 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
1389 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
1391 extern void set_internalvar_string (struct internalvar
*var
,
1392 const char *string
);
1394 extern void clear_internalvar (struct internalvar
*var
);
1396 extern void set_internalvar_component (struct internalvar
*var
,
1398 LONGEST bitpos
, LONGEST bitsize
,
1399 struct value
*newvalue
);
1401 extern struct internalvar
*lookup_only_internalvar (const char *name
);
1403 extern struct internalvar
*create_internalvar (const char *name
);
1405 extern void complete_internalvar (completion_tracker
&tracker
,
1408 /* An internalvar can be dynamically computed by supplying a vector of
1409 function pointers to perform various operations. */
1411 struct internalvar_funcs
1413 /* Compute the value of the variable. The DATA argument passed to
1414 the function is the same argument that was passed to
1415 `create_internalvar_type_lazy'. */
1417 struct value
*(*make_value
) (struct gdbarch
*arch
,
1418 struct internalvar
*var
,
1421 /* Update the agent expression EXPR with bytecode to compute the
1422 value. VALUE is the agent value we are updating. The DATA
1423 argument passed to this function is the same argument that was
1424 passed to `create_internalvar_type_lazy'. If this pointer is
1425 NULL, then the internalvar cannot be compiled to an agent
1428 void (*compile_to_ax
) (struct internalvar
*var
,
1429 struct agent_expr
*expr
,
1430 struct axs_value
*value
,
1434 extern struct internalvar
*create_internalvar_type_lazy (const char *name
,
1435 const struct internalvar_funcs
*funcs
,
1438 /* Compile an internal variable to an agent expression. VAR is the
1439 variable to compile; EXPR and VALUE are the agent expression we are
1440 updating. This will return 0 if there is no known way to compile
1441 VAR, and 1 if VAR was successfully compiled. It may also throw an
1442 exception on error. */
1444 extern int compile_internalvar_to_ax (struct internalvar
*var
,
1445 struct agent_expr
*expr
,
1446 struct axs_value
*value
);
1448 extern struct internalvar
*lookup_internalvar (const char *name
);
1450 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
1452 extern int value_equal_contents (struct value
*arg1
, struct value
*arg2
);
1454 extern int value_less (struct value
*arg1
, struct value
*arg2
);
1456 /* Simulate the C operator ! -- return true if ARG1 contains zero. */
1457 extern bool value_logical_not (struct value
*arg1
);
1459 /* Returns true if the value VAL represents a true value. */
1461 value_true (struct value
*val
)
1463 return !value_logical_not (val
);
1468 extern struct value
*value_of_this (const struct language_defn
*lang
);
1470 extern struct value
*value_of_this_silent (const struct language_defn
*lang
);
1472 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
1474 enum exp_opcode otherop
,
1475 enum noside noside
);
1477 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
1478 enum noside noside
);
1480 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
1481 int j
, struct type
*type
, LONGEST offset
);
1483 extern int binop_types_user_defined_p (enum exp_opcode op
,
1485 struct type
*type2
);
1487 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
1488 struct value
*arg2
);
1490 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
1492 extern int destructor_name_p (const char *name
, struct type
*type
);
1494 extern value_ref_ptr
release_value (struct value
*val
);
1496 extern void modify_field (struct type
*type
, gdb_byte
*addr
,
1497 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
);
1499 extern void type_print (struct type
*type
, const char *varstring
,
1500 struct ui_file
*stream
, int show
);
1502 extern std::string
type_to_string (struct type
*type
);
1504 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
1506 struct value
**valuep
, int *errp
);
1508 extern void print_longest (struct ui_file
*stream
, int format
,
1509 int use_local
, LONGEST val
);
1511 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
1512 struct ui_file
*stream
);
1514 extern void value_print (struct value
*val
, struct ui_file
*stream
,
1515 const struct value_print_options
*options
);
1517 /* Release values from the value chain and return them. Values
1518 created after MARK are released. If MARK is nullptr, or if MARK is
1519 not found on the value chain, then all values are released. Values
1520 are returned in reverse order of creation; that is, newest
1523 extern std::vector
<value_ref_ptr
> value_release_to_mark
1524 (const struct value
*mark
);
1526 extern void common_val_print (struct value
*val
,
1527 struct ui_file
*stream
, int recurse
,
1528 const struct value_print_options
*options
,
1529 const struct language_defn
*language
);
1531 extern int val_print_string (struct type
*elttype
, const char *encoding
,
1532 CORE_ADDR addr
, int len
,
1533 struct ui_file
*stream
,
1534 const struct value_print_options
*options
);
1536 extern void print_variable_and_value (const char *name
,
1538 frame_info_ptr frame
,
1539 struct ui_file
*stream
,
1542 extern void typedef_print (struct type
*type
, struct symbol
*news
,
1543 struct ui_file
*stream
);
1545 extern const char *internalvar_name (const struct internalvar
*var
);
1547 extern void preserve_values (struct objfile
*);
1551 extern struct value
*make_cv_value (int, int, struct value
*);
1555 extern struct value
*varying_to_slice (struct value
*);
1557 extern struct value
*value_slice (struct value
*, int, int);
1559 /* Create a complex number. The type is the complex type; the values
1560 are cast to the underlying scalar type before the complex number is
1563 extern struct value
*value_literal_complex (struct value
*, struct value
*,
1566 /* Return the real part of a complex value. */
1568 extern struct value
*value_real_part (struct value
*value
);
1570 /* Return the imaginary part of a complex value. */
1572 extern struct value
*value_imaginary_part (struct value
*value
);
1574 extern struct value
*find_function_in_inferior (const char *,
1577 extern struct value
*value_allocate_space_in_inferior (int);
1579 /* User function handler. */
1581 typedef struct value
*(*internal_function_fn
) (struct gdbarch
*gdbarch
,
1582 const struct language_defn
*language
,
1585 struct value
**argv
);
1587 /* Add a new internal function. NAME is the name of the function; DOC
1588 is a documentation string describing the function. HANDLER is
1589 called when the function is invoked. COOKIE is an arbitrary
1590 pointer which is passed to HANDLER and is intended for "user
1593 extern void add_internal_function (const char *name
, const char *doc
,
1594 internal_function_fn handler
,
1597 /* This overload takes an allocated documentation string. */
1599 extern void add_internal_function (gdb::unique_xmalloc_ptr
<char> &&name
,
1600 gdb::unique_xmalloc_ptr
<char> &&doc
,
1601 internal_function_fn handler
,
1604 struct value
*call_internal_function (struct gdbarch
*gdbarch
,
1605 const struct language_defn
*language
,
1606 struct value
*function
,
1607 int argc
, struct value
**argv
);
1609 const char *value_internal_function_name (struct value
*);
1611 /* Destroy the values currently allocated. This is called when GDB is
1612 exiting (e.g., on quit_force). */
1613 extern void finalize_values ();
1615 /* Convert VALUE to a gdb_mpq. The caller must ensure that VALUE is
1616 of floating-point, fixed-point, or integer type. */
1617 extern gdb_mpq
value_to_gdb_mpq (struct value
*value
);
1619 /* Return true if LEN (in bytes) exceeds the max-value-size setting,
1620 otherwise, return false. If the user has disabled (set to unlimited)
1621 the max-value-size setting then this function will always return false. */
1622 extern bool exceeds_max_value_size (ULONGEST length
);
1624 /* While an instance of this class is live, and array values that are
1625 created, that are larger than max_value_size, will be restricted in size
1626 to a particular number of elements. */
1628 struct scoped_array_length_limiting
1630 /* Limit any large array values to only contain ELEMENTS elements. */
1631 scoped_array_length_limiting (int elements
);
1633 /* Restore the previous array value limit. */
1634 ~scoped_array_length_limiting ();
1637 /* Used to hold the previous array value element limit. */
1638 gdb::optional
<int> m_old_value
;
1641 #endif /* !defined (VALUE_H) */