1 /* Definitions for values of C expressions, for GDB.
3 Copyright (C) 1986-2021 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 /* The structure which defines the type of a value. It should never
88 be possible for a program lval value to survive over a call to the
89 inferior (i.e. to be put into the history list or an internal
94 /* Increase VAL's reference count. */
96 extern void value_incref (struct value
*val
);
98 /* Decrease VAL's reference count. When the reference count drops to
99 0, VAL will be freed. */
101 extern void value_decref (struct value
*val
);
103 /* A policy class to interface gdb::ref_ptr with struct value. */
105 struct value_ref_policy
107 static void incref (struct value
*ptr
)
112 static void decref (struct value
*ptr
)
118 /* A gdb:;ref_ptr pointer to a struct value. */
120 typedef gdb::ref_ptr
<struct value
, value_ref_policy
> value_ref_ptr
;
122 /* Values are stored in a chain, so that they can be deleted easily
123 over calls to the inferior. Values assigned to internal variables,
124 put into the value history or exposed to Python are taken off this
127 struct value
*value_next (const struct value
*);
129 /* Type of the value. */
131 extern struct type
*value_type (const struct value
*);
133 /* Return the gdbarch associated with the value. */
135 extern struct gdbarch
*get_value_arch (const struct value
*value
);
137 /* This is being used to change the type of an existing value, that
138 code should instead be creating a new value with the changed type
139 (but possibly shared content). */
141 extern void deprecated_set_value_type (struct value
*value
,
144 /* Only used for bitfields; number of bits contained in them. */
146 extern LONGEST
value_bitsize (const struct value
*);
147 extern void set_value_bitsize (struct value
*, LONGEST bit
);
149 /* Only used for bitfields; position of start of field. For
150 little-endian targets, it is the position of the LSB. For
151 big-endian targets, it is the position of the MSB. */
153 extern LONGEST
value_bitpos (const struct value
*);
154 extern void set_value_bitpos (struct value
*, LONGEST bit
);
156 /* Only used for bitfields; the containing value. This allows a
157 single read from the target when displaying multiple
160 struct value
*value_parent (const struct value
*);
161 extern void set_value_parent (struct value
*value
, struct value
*parent
);
163 /* Describes offset of a value within lval of a structure in bytes.
164 If lval == lval_memory, this is an offset to the address. If lval
165 == lval_register, this is a further offset from location.address
166 within the registers structure. Note also the member
167 embedded_offset below. */
169 extern LONGEST
value_offset (const struct value
*);
170 extern void set_value_offset (struct value
*, LONGEST offset
);
172 /* The comment from "struct value" reads: ``Is it modifiable? Only
173 relevant if lval != not_lval.''. Shouldn't the value instead be
174 not_lval and be done with it? */
176 extern int deprecated_value_modifiable (const struct value
*value
);
178 /* If a value represents a C++ object, then the `type' field gives the
179 object's compile-time type. If the object actually belongs to some
180 class derived from `type', perhaps with other base classes and
181 additional members, then `type' is just a subobject of the real
182 thing, and the full object is probably larger than `type' would
185 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
186 actually determine the object's run-time type by looking at the
187 run-time type information in the vtable. When this information is
188 available, we may elect to read in the entire object, for several
191 - When printing the value, the user would probably rather see the
192 full object, not just the limited portion apparent from the
195 - If `type' has virtual base classes, then even printing `type'
196 alone may require reaching outside the `type' portion of the
197 object to wherever the virtual base class has been stored.
199 When we store the entire object, `enclosing_type' is the run-time
200 type -- the complete object -- and `embedded_offset' is the offset
201 of `type' within that larger type, in bytes. The value_contents()
202 macro takes `embedded_offset' into account, so most GDB code
203 continues to see the `type' portion of the value, just as the
206 If `type' is a pointer to an object, then `enclosing_type' is a
207 pointer to the object's run-time type, and `pointed_to_offset' is
208 the offset in bytes from the full object to the pointed-to object
209 -- that is, the value `embedded_offset' would have if we followed
210 the pointer and fetched the complete object. (I don't really see
211 the point. Why not just determine the run-time type when you
212 indirect, and avoid the special case? The contents don't matter
213 until you indirect anyway.)
215 If we're not doing anything fancy, `enclosing_type' is equal to
216 `type', and `embedded_offset' is zero, so everything works
219 extern struct type
*value_enclosing_type (const struct value
*);
220 extern void set_value_enclosing_type (struct value
*val
,
221 struct type
*new_type
);
223 /* Returns value_type or value_enclosing_type depending on
224 value_print_options.objectprint.
226 If RESOLVE_SIMPLE_TYPES is 0 the enclosing type will be resolved
227 only for pointers and references, else it will be returned
228 for all the types (e.g. structures). This option is useful
229 to prevent retrieving enclosing type for the base classes fields.
231 REAL_TYPE_FOUND is used to inform whether the real type was found
232 (or just static type was used). The NULL may be passed if it is not
235 extern struct type
*value_actual_type (struct value
*value
,
236 int resolve_simple_types
,
237 int *real_type_found
);
239 extern LONGEST
value_pointed_to_offset (const struct value
*value
);
240 extern void set_value_pointed_to_offset (struct value
*value
, LONGEST val
);
241 extern LONGEST
value_embedded_offset (const struct value
*value
);
242 extern void set_value_embedded_offset (struct value
*value
, LONGEST val
);
244 /* For lval_computed values, this structure holds functions used to
245 retrieve and set the value (or portions of the value).
247 For each function, 'V' is the 'this' pointer: an lval_funcs
248 function F may always assume that the V it receives is an
249 lval_computed value, and has F in the appropriate slot of its
250 lval_funcs structure. */
254 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
255 a problem arises in obtaining VALUE's bits, this function should
256 call 'error'. If it is NULL value_fetch_lazy on "un-lazy"
257 non-optimized-out value is an internal error. */
258 void (*read
) (struct value
*v
);
260 /* Handle an assignment TOVAL = FROMVAL by writing the value of
261 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
262 been updated. If a problem arises in doing so, this function
263 should call 'error'. If it is NULL such TOVAL assignment is an error as
264 TOVAL is not considered as an lvalue. */
265 void (*write
) (struct value
*toval
, struct value
*fromval
);
267 /* If non-NULL, this is used to implement pointer indirection for
268 this value. This method may return NULL, in which case value_ind
269 will fall back to ordinary indirection. */
270 struct value
*(*indirect
) (struct value
*value
);
272 /* If non-NULL, this is used to implement reference resolving for
273 this value. This method may return NULL, in which case coerce_ref
274 will fall back to ordinary references resolving. */
275 struct value
*(*coerce_ref
) (const struct value
*value
);
277 /* If non-NULL, this is used to determine whether the indicated bits
278 of VALUE are a synthetic pointer. */
279 int (*check_synthetic_pointer
) (const struct value
*value
,
280 LONGEST offset
, int length
);
282 /* Return a duplicate of VALUE's closure, for use in a new value.
283 This may simply return the same closure, if VALUE's is
284 reference-counted or statically allocated.
286 This may be NULL, in which case VALUE's closure is re-used in the
288 void *(*copy_closure
) (const struct value
*v
);
290 /* Drop VALUE's reference to its closure. Maybe this frees the
291 closure; maybe this decrements a reference count; maybe the
292 closure is statically allocated and this does nothing.
294 This may be NULL, in which case no action is taken to free
296 void (*free_closure
) (struct value
*v
);
299 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
300 and closure CLOSURE. */
302 extern struct value
*allocate_computed_value (struct type
*type
,
303 const struct lval_funcs
*funcs
,
306 extern struct value
*allocate_optimized_out_value (struct type
*type
);
308 /* If VALUE is lval_computed, return its lval_funcs structure. */
310 extern const struct lval_funcs
*value_computed_funcs (const struct value
*);
312 /* If VALUE is lval_computed, return its closure. The meaning of the
313 returned value depends on the functions VALUE uses. */
315 extern void *value_computed_closure (const struct value
*value
);
317 /* If zero, contents of this value are in the contents field. If
318 nonzero, contents are in inferior. If the lval field is lval_memory,
319 the contents are in inferior memory at location.address plus offset.
320 The lval field may also be lval_register.
322 WARNING: This field is used by the code which handles watchpoints
323 (see breakpoint.c) to decide whether a particular value can be
324 watched by hardware watchpoints. If the lazy flag is set for some
325 member of a value chain, it is assumed that this member of the
326 chain doesn't need to be watched as part of watching the value
327 itself. This is how GDB avoids watching the entire struct or array
328 when the user wants to watch a single struct member or array
329 element. If you ever change the way lazy flag is set and reset, be
330 sure to consider this use as well! */
332 extern int value_lazy (const struct value
*);
333 extern void set_value_lazy (struct value
*value
, int val
);
335 extern int value_stack (const struct value
*);
336 extern void set_value_stack (struct value
*value
, int val
);
338 /* Throw an error complaining that the value has been optimized
341 extern void error_value_optimized_out (void);
343 /* value_contents() and value_contents_raw() both return the address
344 of the gdb buffer used to hold a copy of the contents of the lval.
345 value_contents() is used when the contents of the buffer are needed
346 -- it uses value_fetch_lazy() to load the buffer from the process
347 being debugged if it hasn't already been loaded
348 (value_contents_writeable() is used when a writeable but fetched
349 buffer is required).. value_contents_raw() is used when data is
350 being stored into the buffer, or when it is certain that the
351 contents of the buffer are valid.
353 Note: The contents pointer is adjusted by the offset required to
354 get to the real subobject, if the value happens to represent
355 something embedded in a larger run-time object. */
357 extern gdb_byte
*value_contents_raw (struct value
*);
359 /* Actual contents of the value. For use of this value; setting it
360 uses the stuff above. Not valid if lazy is nonzero. Target
361 byte-order. We force it to be aligned properly for any possible
362 value. Note that a value therefore extends beyond what is
365 extern const gdb_byte
*value_contents (struct value
*);
366 extern gdb_byte
*value_contents_writeable (struct value
*);
368 /* The ALL variants of the above two macros do not adjust the returned
369 pointer by the embedded_offset value. */
371 extern gdb_byte
*value_contents_all_raw (struct value
*);
372 extern const gdb_byte
*value_contents_all (struct value
*);
374 /* Like value_contents_all, but does not require that the returned
375 bits be valid. This should only be used in situations where you
376 plan to check the validity manually. */
377 extern const gdb_byte
*value_contents_for_printing (struct value
*value
);
379 /* Like value_contents_for_printing, but accepts a constant value
380 pointer. Unlike value_contents_for_printing however, the pointed
381 value must _not_ be lazy. */
382 extern const gdb_byte
*
383 value_contents_for_printing_const (const struct value
*value
);
385 extern void value_fetch_lazy (struct value
*val
);
387 /* If nonzero, this is the value of a variable which does not actually
388 exist in the program, at least partially. If the value is lazy,
389 this may fetch it now. */
390 extern int value_optimized_out (struct value
*value
);
392 /* Given a value, return true if any of the contents bits starting at
393 OFFSET and extending for LENGTH bits is optimized out, false
396 extern int value_bits_any_optimized_out (const struct value
*value
,
397 int bit_offset
, int bit_length
);
399 /* Like value_optimized_out, but return true iff the whole value is
401 extern int value_entirely_optimized_out (struct value
*value
);
403 /* Mark VALUE's content bytes starting at OFFSET and extending for
404 LENGTH bytes as optimized out. */
406 extern void mark_value_bytes_optimized_out (struct value
*value
,
407 int offset
, int length
);
409 /* Mark VALUE's content bits starting at OFFSET and extending for
410 LENGTH bits as optimized out. */
412 extern void mark_value_bits_optimized_out (struct value
*value
,
413 LONGEST offset
, LONGEST length
);
415 /* Set or return field indicating whether a variable is initialized or
416 not, based on debugging information supplied by the compiler.
417 1 = initialized; 0 = uninitialized. */
418 extern int value_initialized (const struct value
*);
419 extern void set_value_initialized (struct value
*, int);
421 /* Set COMPONENT's location as appropriate for a component of WHOLE
422 --- regardless of what kind of lvalue WHOLE is. */
423 extern void set_value_component_location (struct value
*component
,
424 const struct value
*whole
);
426 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
427 single value might have multiple LVALs), this hacked interface is
428 limited to just the first PIECE. Expect further change. */
429 /* Type of value; either not an lval, or one of the various different
430 possible kinds of lval. */
431 extern enum lval_type
*deprecated_value_lval_hack (struct value
*);
432 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
434 /* Like VALUE_LVAL, except the parameter can be const. */
435 extern enum lval_type
value_lval_const (const struct value
*value
);
437 /* If lval == lval_memory, return the address in the inferior. If
438 lval == lval_register, return the byte offset into the registers
439 structure. Otherwise, return 0. The returned address
440 includes the offset, if any. */
441 extern CORE_ADDR
value_address (const struct value
*);
443 /* Like value_address, except the result does not include value's
445 extern CORE_ADDR
value_raw_address (const struct value
*);
447 /* Set the address of a value. */
448 extern void set_value_address (struct value
*, CORE_ADDR
);
450 /* Pointer to internal variable. */
451 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
452 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
454 /* Frame ID of "next" frame to which a register value is relative. A
455 register value is indicated by VALUE_LVAL being set to lval_register.
456 So, if the register value is found relative to frame F, then the
457 frame id of F->next will be stored in VALUE_NEXT_FRAME_ID. */
458 extern struct frame_id
*deprecated_value_next_frame_id_hack (struct value
*);
459 #define VALUE_NEXT_FRAME_ID(val) (*deprecated_value_next_frame_id_hack (val))
461 /* Register number if the value is from a register. */
462 extern int *deprecated_value_regnum_hack (struct value
*);
463 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
465 /* Return value after lval_funcs->coerce_ref (after check_typedef). Return
466 NULL if lval_funcs->coerce_ref is not applicable for whatever reason. */
468 extern struct value
*coerce_ref_if_computed (const struct value
*arg
);
470 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
471 ENC_TYPE is the new enclosing type that should be set. ORIGINAL_TYPE and
472 ORIGINAL_VAL are the type and value of the original reference or
473 pointer. ORIGINAL_VALUE_ADDRESS is the address within VALUE, that is
474 the address that was dereferenced.
476 Note, that VALUE is modified by this function.
478 It is a common implementation for coerce_ref and value_ind. */
480 extern struct value
* readjust_indirect_value_type (struct value
*value
,
481 struct type
*enc_type
,
482 const struct type
*original_type
,
483 struct value
*original_val
,
484 CORE_ADDR original_value_address
);
486 /* Convert a REF to the object referenced. */
488 extern struct value
*coerce_ref (struct value
*value
);
490 /* If ARG is an array, convert it to a pointer.
491 If ARG is a function, convert it to a function pointer.
493 References are dereferenced. */
495 extern struct value
*coerce_array (struct value
*value
);
497 /* Given a value, determine whether the bits starting at OFFSET and
498 extending for LENGTH bits are a synthetic pointer. */
500 extern int value_bits_synthetic_pointer (const struct value
*value
,
501 LONGEST offset
, LONGEST length
);
503 /* Given a value, determine whether the contents bytes starting at
504 OFFSET and extending for LENGTH bytes are available. This returns
505 nonzero if all bytes in the given range are available, zero if any
506 byte is unavailable. */
508 extern int value_bytes_available (const struct value
*value
,
509 LONGEST offset
, LONGEST length
);
511 /* Given a value, determine whether the contents bits starting at
512 OFFSET and extending for LENGTH bits are available. This returns
513 nonzero if all bits in the given range are available, zero if any
514 bit is unavailable. */
516 extern int value_bits_available (const struct value
*value
,
517 LONGEST offset
, LONGEST length
);
519 /* Like value_bytes_available, but return false if any byte in the
520 whole object is unavailable. */
521 extern int value_entirely_available (struct value
*value
);
523 /* Like value_entirely_available, but return false if any byte in the
524 whole object is available. */
525 extern int value_entirely_unavailable (struct value
*value
);
527 /* Mark VALUE's content bytes starting at OFFSET and extending for
528 LENGTH bytes as unavailable. */
530 extern void mark_value_bytes_unavailable (struct value
*value
,
531 LONGEST offset
, LONGEST length
);
533 /* Mark VALUE's content bits starting at OFFSET and extending for
534 LENGTH bits as unavailable. */
536 extern void mark_value_bits_unavailable (struct value
*value
,
537 LONGEST offset
, LONGEST length
);
539 /* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
540 LENGTH bytes of VAL2's contents starting at OFFSET2.
542 Note that "contents" refers to the whole value's contents
543 (value_contents_all), without any embedded offset adjustment. For
544 example, to compare a complete object value with itself, including
545 its enclosing type chunk, you'd do:
547 int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
548 value_contents_eq (val, 0, val, 0, len);
550 Returns true iff the set of available/valid contents match.
552 Optimized-out contents are equal to optimized-out contents, and are
553 not equal to non-optimized-out contents.
555 Unavailable contents are equal to unavailable contents, and are not
556 equal to non-unavailable contents.
558 For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
559 represent different available/valid bytes, in a value with length
563 contents: xxxxVVVVxxxxVVZZ
567 value_contents_eq(val, 0, val, 8, 6) => true
568 value_contents_eq(val, 0, val, 4, 4) => false
569 value_contents_eq(val, 0, val, 8, 8) => false
570 value_contents_eq(val, 4, val, 12, 2) => true
571 value_contents_eq(val, 4, val, 12, 4) => true
572 value_contents_eq(val, 3, val, 4, 4) => true
574 If 'x's represent an unavailable byte, 'o' represents an optimized
575 out byte, in a value with length 8:
582 value_contents_eq(val, 0, val, 2, 2) => true
583 value_contents_eq(val, 4, val, 6, 2) => true
584 value_contents_eq(val, 0, val, 4, 4) => true
586 We only know whether a value chunk is unavailable or optimized out
587 if we've tried to read it. As this routine is used by printing
588 routines, which may be printing values in the value history, long
589 after the inferior is gone, it works with const values. Therefore,
590 this routine must not be called with lazy values. */
592 extern bool value_contents_eq (const struct value
*val1
, LONGEST offset1
,
593 const struct value
*val2
, LONGEST offset2
,
596 /* Read LENGTH addressable memory units starting at MEMADDR into BUFFER,
597 which is (or will be copied to) VAL's contents buffer offset by
598 BIT_OFFSET bits. Marks value contents ranges as unavailable if
599 the corresponding memory is likewise unavailable. STACK indicates
600 whether the memory is known to be stack memory. */
602 extern void read_value_memory (struct value
*val
, LONGEST bit_offset
,
603 int stack
, CORE_ADDR memaddr
,
604 gdb_byte
*buffer
, size_t length
);
606 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
607 into each element of a new vector value with VECTOR_TYPE. */
609 struct value
*value_vector_widen (struct value
*scalar_value
,
610 struct type
*vector_type
);
615 #include "gdbtypes.h"
616 #include "expression.h"
621 extern int print_address_demangle (const struct value_print_options
*,
622 struct gdbarch
*, CORE_ADDR
,
623 struct ui_file
*, int);
625 /* Returns true if VAL is of floating-point type. In addition,
626 throws an error if the value is an invalid floating-point value. */
627 extern bool is_floating_value (struct value
*val
);
629 extern LONGEST
value_as_long (struct value
*val
);
630 extern CORE_ADDR
value_as_address (struct value
*val
);
632 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
633 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
635 extern LONGEST
unpack_field_as_long (struct type
*type
,
636 const gdb_byte
*valaddr
,
639 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
640 VALADDR, and store the result in *RESULT.
641 The bitfield starts at BITPOS bits and contains BITSIZE bits; if
642 BITSIZE is zero, then the length is taken from FIELD_TYPE.
644 Extracting bits depends on endianness of the machine. Compute the
645 number of least significant bits to discard. For big endian machines,
646 we compute the total number of bits in the anonymous object, subtract
647 off the bit count from the MSB of the object to the MSB of the
648 bitfield, then the size of the bitfield, which leaves the LSB discard
649 count. For little endian machines, the discard count is simply the
650 number of bits from the LSB of the anonymous object to the LSB of the
653 If the field is signed, we also do sign extension. */
655 extern LONGEST
unpack_bits_as_long (struct type
*field_type
,
656 const gdb_byte
*valaddr
,
657 LONGEST bitpos
, LONGEST bitsize
);
659 extern int unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
660 LONGEST embedded_offset
, int fieldno
,
661 const struct value
*val
, LONGEST
*result
);
663 extern void unpack_value_bitfield (struct value
*dest_val
,
664 LONGEST bitpos
, LONGEST bitsize
,
665 const gdb_byte
*valaddr
,
666 LONGEST embedded_offset
,
667 const struct value
*val
);
669 extern struct value
*value_field_bitfield (struct type
*type
, int fieldno
,
670 const gdb_byte
*valaddr
,
671 LONGEST embedded_offset
,
672 const struct value
*val
);
674 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
676 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
677 extern struct value
*value_from_ulongest (struct type
*type
, ULONGEST num
);
678 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
679 extern struct value
*value_from_host_double (struct type
*type
, double d
);
680 extern struct value
*value_from_history_ref (const char *, const char **);
681 extern struct value
*value_from_component (struct value
*, struct type
*,
684 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
685 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
687 extern struct value
*value_from_contents_and_address_unresolved
688 (struct type
*, const gdb_byte
*, CORE_ADDR
);
689 extern struct value
*value_from_contents_and_address (struct type
*,
692 extern struct value
*value_from_contents (struct type
*, const gdb_byte
*);
694 extern struct value
*default_value_from_register (struct gdbarch
*gdbarch
,
697 struct frame_id frame_id
);
699 extern void read_frame_register_value (struct value
*value
,
700 struct frame_info
*frame
);
702 extern struct value
*value_from_register (struct type
*type
, int regnum
,
703 struct frame_info
*frame
);
705 extern CORE_ADDR
address_from_register (int regnum
,
706 struct frame_info
*frame
);
708 extern struct value
*value_of_variable (struct symbol
*var
,
709 const struct block
*b
);
711 extern struct value
*address_of_variable (struct symbol
*var
,
712 const struct block
*b
);
714 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
716 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
718 /* Return the symbol's reading requirement. */
720 extern enum symbol_needs_kind
symbol_read_needs (struct symbol
*);
722 /* Return true if the symbol needs a frame. This is a wrapper for
723 symbol_read_needs that simply checks for SYMBOL_NEEDS_FRAME. */
725 extern int symbol_read_needs_frame (struct symbol
*);
727 extern struct value
*read_var_value (struct symbol
*var
,
728 const struct block
*var_block
,
729 struct frame_info
*frame
);
731 extern struct value
*allocate_value (struct type
*type
);
732 extern struct value
*allocate_value_lazy (struct type
*type
);
733 extern void value_contents_copy (struct value
*dst
, LONGEST dst_offset
,
734 struct value
*src
, LONGEST src_offset
,
737 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
739 extern struct value
*value_mark (void);
741 extern void value_free_to_mark (const struct value
*mark
);
743 /* A helper class that uses value_mark at construction time and calls
744 value_free_to_mark in the destructor. This is used to clear out
745 temporary values created during the lifetime of this object. */
746 class scoped_value_mark
751 : m_value (value_mark ())
755 ~scoped_value_mark ()
760 scoped_value_mark (scoped_value_mark
&&other
) = default;
762 DISABLE_COPY_AND_ASSIGN (scoped_value_mark
);
764 /* Free the values currently on the value stack. */
769 value_free_to_mark (m_value
);
776 const struct value
*m_value
;
779 extern struct value
*value_cstring (const char *ptr
, ssize_t len
,
780 struct type
*char_type
);
781 extern struct value
*value_string (const char *ptr
, ssize_t len
,
782 struct type
*char_type
);
784 extern struct value
*value_array (int lowbound
, int highbound
,
785 struct value
**elemvec
);
787 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
789 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
792 extern struct value
*value_ptradd (struct value
*arg1
, LONGEST arg2
);
794 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
796 /* Return true if VAL does not live in target memory, but should in order
797 to operate on it. Otherwise return false. */
799 extern bool value_must_coerce_to_target (struct value
*arg1
);
801 extern struct value
*value_coerce_to_target (struct value
*arg1
);
803 extern struct value
*value_coerce_array (struct value
*arg1
);
805 extern struct value
*value_coerce_function (struct value
*arg1
);
807 extern struct value
*value_ind (struct value
*arg1
);
809 extern struct value
*value_addr (struct value
*arg1
);
811 extern struct value
*value_ref (struct value
*arg1
, enum type_code refcode
);
813 extern struct value
*value_assign (struct value
*toval
,
814 struct value
*fromval
);
816 extern struct value
*value_pos (struct value
*arg1
);
818 extern struct value
*value_neg (struct value
*arg1
);
820 extern struct value
*value_complement (struct value
*arg1
);
822 extern struct value
*value_struct_elt (struct value
**argp
,
823 gdb::optional
<gdb::array_view
<value
*>> args
,
824 const char *name
, int *static_memfuncp
,
827 extern struct value
*value_struct_elt_bitpos (struct value
**argp
,
829 struct type
*field_type
,
832 extern struct value
*value_aggregate_elt (struct type
*curtype
,
834 struct type
*expect_type
,
838 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
840 enum oload_search_type
{ NON_METHOD
, METHOD
, BOTH
};
842 extern int find_overload_match (gdb::array_view
<value
*> args
,
844 enum oload_search_type method
,
845 struct value
**objp
, struct symbol
*fsym
,
846 struct value
**valp
, struct symbol
**symp
,
847 int *staticp
, const int no_adl
,
850 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
852 extern struct value
*value_primitive_field (struct value
*arg1
, LONGEST offset
,
854 struct type
*arg_type
);
857 extern struct type
*value_rtti_indirect_type (struct value
*, int *, LONGEST
*,
860 extern struct value
*value_full_object (struct value
*, struct type
*, int,
863 extern struct value
*value_cast_pointers (struct type
*, struct value
*, int);
865 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
867 extern struct value
*value_reinterpret_cast (struct type
*type
,
870 extern struct value
*value_dynamic_cast (struct type
*type
, struct value
*arg
);
872 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
874 extern struct value
*value_one (struct type
*type
);
876 extern struct value
*value_repeat (struct value
*arg1
, int count
);
878 extern struct value
*value_subscript (struct value
*array
, LONGEST index
);
880 extern struct value
*value_bitstring_subscript (struct type
*type
,
881 struct value
*bitstring
,
884 extern struct value
*register_value_being_returned (struct type
*valtype
,
885 struct regcache
*retbuf
);
887 extern int value_in (struct value
*element
, struct value
*set
);
889 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
892 extern enum return_value_convention
893 struct_return_convention (struct gdbarch
*gdbarch
, struct value
*function
,
894 struct type
*value_type
);
896 extern int using_struct_return (struct gdbarch
*gdbarch
,
897 struct value
*function
,
898 struct type
*value_type
);
900 /* Evaluate the expression EXP. If set, EXPECT_TYPE is passed to the
901 outermost operation's evaluation. This is ignored by most
902 operations, but may be used, e.g., to determine the type of an
903 otherwise untyped symbol. The caller should not assume that the
904 returned value has this type. */
906 extern struct value
*evaluate_expression (struct expression
*exp
,
907 struct type
*expect_type
= nullptr);
909 extern struct value
*evaluate_type (struct expression
*exp
);
911 extern value
*evaluate_var_value (enum noside noside
, const block
*blk
,
914 extern value
*evaluate_var_msym_value (enum noside noside
,
915 struct objfile
*objfile
,
916 minimal_symbol
*msymbol
);
918 namespace expr
{ class operation
; };
919 extern void fetch_subexp_value (struct expression
*exp
,
921 struct value
**valp
, struct value
**resultp
,
922 std::vector
<value_ref_ptr
> *val_chain
,
923 bool preserve_errors
);
925 extern struct value
*parse_and_eval (const char *exp
);
927 extern struct value
*parse_to_comma_and_eval (const char **expp
);
929 extern struct type
*parse_and_eval_type (const char *p
, int length
);
931 extern CORE_ADDR
parse_and_eval_address (const char *exp
);
933 extern LONGEST
parse_and_eval_long (const char *exp
);
935 extern void unop_promote (const struct language_defn
*language
,
936 struct gdbarch
*gdbarch
,
937 struct value
**arg1
);
939 extern void binop_promote (const struct language_defn
*language
,
940 struct gdbarch
*gdbarch
,
941 struct value
**arg1
, struct value
**arg2
);
943 extern struct value
*access_value_history (int num
);
945 extern struct value
*value_of_internalvar (struct gdbarch
*gdbarch
,
946 struct internalvar
*var
);
948 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
950 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
952 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
954 extern void set_internalvar_string (struct internalvar
*var
,
957 extern void clear_internalvar (struct internalvar
*var
);
959 extern void set_internalvar_component (struct internalvar
*var
,
961 LONGEST bitpos
, LONGEST bitsize
,
962 struct value
*newvalue
);
964 extern struct internalvar
*lookup_only_internalvar (const char *name
);
966 extern struct internalvar
*create_internalvar (const char *name
);
968 extern void complete_internalvar (completion_tracker
&tracker
,
971 /* An internalvar can be dynamically computed by supplying a vector of
972 function pointers to perform various operations. */
974 struct internalvar_funcs
976 /* Compute the value of the variable. The DATA argument passed to
977 the function is the same argument that was passed to
978 `create_internalvar_type_lazy'. */
980 struct value
*(*make_value
) (struct gdbarch
*arch
,
981 struct internalvar
*var
,
984 /* Update the agent expression EXPR with bytecode to compute the
985 value. VALUE is the agent value we are updating. The DATA
986 argument passed to this function is the same argument that was
987 passed to `create_internalvar_type_lazy'. If this pointer is
988 NULL, then the internalvar cannot be compiled to an agent
991 void (*compile_to_ax
) (struct internalvar
*var
,
992 struct agent_expr
*expr
,
993 struct axs_value
*value
,
996 /* If non-NULL, this is called to destroy DATA. The DATA argument
997 passed to this function is the same argument that was passed to
998 `create_internalvar_type_lazy'. */
1000 void (*destroy
) (void *data
);
1003 extern struct internalvar
*create_internalvar_type_lazy (const char *name
,
1004 const struct internalvar_funcs
*funcs
,
1007 /* Compile an internal variable to an agent expression. VAR is the
1008 variable to compile; EXPR and VALUE are the agent expression we are
1009 updating. This will return 0 if there is no known way to compile
1010 VAR, and 1 if VAR was successfully compiled. It may also throw an
1011 exception on error. */
1013 extern int compile_internalvar_to_ax (struct internalvar
*var
,
1014 struct agent_expr
*expr
,
1015 struct axs_value
*value
);
1017 extern struct internalvar
*lookup_internalvar (const char *name
);
1019 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
1021 extern int value_equal_contents (struct value
*arg1
, struct value
*arg2
);
1023 extern int value_less (struct value
*arg1
, struct value
*arg2
);
1025 /* Simulate the C operator ! -- return true if ARG1 contains zero. */
1026 extern bool value_logical_not (struct value
*arg1
);
1028 /* Returns true if the value VAL represents a true value. */
1030 value_true (struct value
*val
)
1032 return !value_logical_not (val
);
1037 extern struct value
*value_of_this (const struct language_defn
*lang
);
1039 extern struct value
*value_of_this_silent (const struct language_defn
*lang
);
1041 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
1043 enum exp_opcode otherop
,
1044 enum noside noside
);
1046 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
1047 enum noside noside
);
1049 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
1050 int j
, struct type
*type
, LONGEST offset
);
1052 extern int binop_types_user_defined_p (enum exp_opcode op
,
1054 struct type
*type2
);
1056 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
1057 struct value
*arg2
);
1059 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
1061 extern int destructor_name_p (const char *name
, struct type
*type
);
1063 extern value_ref_ptr
release_value (struct value
*val
);
1065 extern int record_latest_value (struct value
*val
);
1067 extern void modify_field (struct type
*type
, gdb_byte
*addr
,
1068 LONGEST fieldval
, LONGEST bitpos
, LONGEST bitsize
);
1070 extern void type_print (struct type
*type
, const char *varstring
,
1071 struct ui_file
*stream
, int show
);
1073 extern std::string
type_to_string (struct type
*type
);
1075 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
1077 struct value
**valuep
, int *errp
);
1079 extern void print_longest (struct ui_file
*stream
, int format
,
1080 int use_local
, LONGEST val
);
1082 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
1083 struct ui_file
*stream
);
1085 extern void value_print (struct value
*val
, struct ui_file
*stream
,
1086 const struct value_print_options
*options
);
1088 extern void value_print_array_elements (struct value
*val
,
1089 struct ui_file
*stream
, int format
,
1090 enum val_prettyformat pretty
);
1092 /* Release values from the value chain and return them. Values
1093 created after MARK are released. If MARK is nullptr, or if MARK is
1094 not found on the value chain, then all values are released. Values
1095 are returned in reverse order of creation; that is, newest
1098 extern std::vector
<value_ref_ptr
> value_release_to_mark
1099 (const struct value
*mark
);
1101 extern void common_val_print (struct value
*val
,
1102 struct ui_file
*stream
, int recurse
,
1103 const struct value_print_options
*options
,
1104 const struct language_defn
*language
);
1106 extern int val_print_string (struct type
*elttype
, const char *encoding
,
1107 CORE_ADDR addr
, int len
,
1108 struct ui_file
*stream
,
1109 const struct value_print_options
*options
);
1111 extern void print_variable_and_value (const char *name
,
1113 struct frame_info
*frame
,
1114 struct ui_file
*stream
,
1117 extern void typedef_print (struct type
*type
, struct symbol
*news
,
1118 struct ui_file
*stream
);
1120 extern const char *internalvar_name (const struct internalvar
*var
);
1122 extern void preserve_values (struct objfile
*);
1126 extern struct value
*value_copy (struct value
*);
1128 extern struct value
*value_non_lval (struct value
*);
1130 extern void value_force_lval (struct value
*, CORE_ADDR
);
1132 extern struct value
*make_cv_value (int, int, struct value
*);
1134 extern void preserve_one_value (struct value
*, struct objfile
*, htab_t
);
1138 extern struct value
*varying_to_slice (struct value
*);
1140 extern struct value
*value_slice (struct value
*, int, int);
1142 /* Create a complex number. The type is the complex type; the values
1143 are cast to the underlying scalar type before the complex number is
1146 extern struct value
*value_literal_complex (struct value
*, struct value
*,
1149 /* Return the real part of a complex value. */
1151 extern struct value
*value_real_part (struct value
*value
);
1153 /* Return the imaginary part of a complex value. */
1155 extern struct value
*value_imaginary_part (struct value
*value
);
1157 extern struct value
*find_function_in_inferior (const char *,
1160 extern struct value
*value_allocate_space_in_inferior (int);
1162 extern struct value
*value_subscripted_rvalue (struct value
*array
,
1164 LONGEST lowerbound
);
1166 /* User function handler. */
1168 typedef struct value
*(*internal_function_fn
) (struct gdbarch
*gdbarch
,
1169 const struct language_defn
*language
,
1172 struct value
**argv
);
1174 /* Add a new internal function. NAME is the name of the function; DOC
1175 is a documentation string describing the function. HANDLER is
1176 called when the function is invoked. COOKIE is an arbitrary
1177 pointer which is passed to HANDLER and is intended for "user
1180 extern void add_internal_function (const char *name
, const char *doc
,
1181 internal_function_fn handler
,
1184 /* This overload takes an allocated documentation string. */
1186 extern void add_internal_function (gdb::unique_xmalloc_ptr
<char> &&name
,
1187 gdb::unique_xmalloc_ptr
<char> &&doc
,
1188 internal_function_fn handler
,
1191 struct value
*call_internal_function (struct gdbarch
*gdbarch
,
1192 const struct language_defn
*language
,
1193 struct value
*function
,
1194 int argc
, struct value
**argv
);
1196 const char *value_internal_function_name (struct value
*);
1198 /* Build a value wrapping and representing WORKER. The value takes ownership
1199 of the xmethod_worker object. */
1201 extern struct value
*value_from_xmethod (xmethod_worker_up
&&worker
);
1203 extern struct type
*result_type_of_xmethod (struct value
*method
,
1204 gdb::array_view
<value
*> argv
);
1206 extern struct value
*call_xmethod (struct value
*method
,
1207 gdb::array_view
<value
*> argv
);
1209 /* Destroy the values currently allocated. This is called when GDB is
1210 exiting (e.g., on quit_force). */
1211 extern void finalize_values ();
1213 /* Convert VALUE to a gdb_mpq. The caller must ensure that VALUE is
1214 of floating-point, fixed-point, or integer type. */
1215 extern gdb_mpq
value_to_gdb_mpq (struct value
*value
);
1217 #endif /* !defined (VALUE_H) */