1 /* Definitions for values of C expressions, for GDB.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008, 2009 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #if !defined (VALUE_H)
26 #include "frame.h" /* For struct frame_id. */
35 struct value_print_options
;
37 /* The structure which defines the type of a value. It should never
38 be possible for a program lval value to survive over a call to the
39 inferior (i.e. to be put into the history list or an internal
44 /* Values are stored in a chain, so that they can be deleted easily
45 over calls to the inferior. Values assigned to internal variables,
46 put into the value history or exposed to Python are taken off this
49 struct value
*value_next (struct value
*);
51 /* Type of the value. */
53 extern struct type
*value_type (struct value
*);
55 /* This is being used to change the type of an existing value, that
56 code should instead be creating a new value with the changed type
57 (but possibly shared content). */
59 extern void deprecated_set_value_type (struct value
*value
,
62 /* Only used for bitfields; number of bits contained in them. */
64 extern int value_bitsize (struct value
*);
65 extern void set_value_bitsize (struct value
*, int bit
);
67 /* Only used for bitfields; position of start of field. For
68 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
69 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
71 extern int value_bitpos (struct value
*);
72 extern void set_value_bitpos (struct value
*, int bit
);
74 /* Only used for bitfields; the containing value. This allows a
75 single read from the target when displaying multiple
78 struct value
*value_parent (struct value
*);
80 /* Describes offset of a value within lval of a structure in bytes.
81 If lval == lval_memory, this is an offset to the address. If lval
82 == lval_register, this is a further offset from location.address
83 within the registers structure. Note also the member
84 embedded_offset below. */
86 extern int value_offset (struct value
*);
87 extern void set_value_offset (struct value
*, int offset
);
89 /* The comment from "struct value" reads: ``Is it modifiable? Only
90 relevant if lval != not_lval.''. Shouldn't the value instead be
91 not_lval and be done with it? */
93 extern int deprecated_value_modifiable (struct value
*value
);
94 extern void deprecated_set_value_modifiable (struct value
*value
,
97 /* If a value represents a C++ object, then the `type' field gives the
98 object's compile-time type. If the object actually belongs to some
99 class derived from `type', perhaps with other base classes and
100 additional members, then `type' is just a subobject of the real
101 thing, and the full object is probably larger than `type' would
104 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
105 actually determine the object's run-time type by looking at the
106 run-time type information in the vtable. When this information is
107 available, we may elect to read in the entire object, for several
110 - When printing the value, the user would probably rather see the
111 full object, not just the limited portion apparent from the
114 - If `type' has virtual base classes, then even printing `type'
115 alone may require reaching outside the `type' portion of the
116 object to wherever the virtual base class has been stored.
118 When we store the entire object, `enclosing_type' is the run-time
119 type -- the complete object -- and `embedded_offset' is the offset
120 of `type' within that larger type, in bytes. The value_contents()
121 macro takes `embedded_offset' into account, so most GDB code
122 continues to see the `type' portion of the value, just as the
125 If `type' is a pointer to an object, then `enclosing_type' is a
126 pointer to the object's run-time type, and `pointed_to_offset' is
127 the offset in bytes from the full object to the pointed-to object
128 -- that is, the value `embedded_offset' would have if we followed
129 the pointer and fetched the complete object. (I don't really see
130 the point. Why not just determine the run-time type when you
131 indirect, and avoid the special case? The contents don't matter
132 until you indirect anyway.)
134 If we're not doing anything fancy, `enclosing_type' is equal to
135 `type', and `embedded_offset' is zero, so everything works
138 extern struct type
*value_enclosing_type (struct value
*);
139 extern struct value
*value_change_enclosing_type (struct value
*val
,
140 struct type
*new_type
);
141 extern int value_pointed_to_offset (struct value
*value
);
142 extern void set_value_pointed_to_offset (struct value
*value
, int val
);
143 extern int value_embedded_offset (struct value
*value
);
144 extern void set_value_embedded_offset (struct value
*value
, int val
);
146 /* For lval_computed values, this structure holds functions used to
147 retrieve and set the value (or portions of the value).
149 For each function, 'V' is the 'this' pointer: an lval_funcs
150 function F may always assume that the V it receives is an
151 lval_computed value, and has F in the appropriate slot of its
152 lval_funcs structure. */
156 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
157 a problem arises in obtaining VALUE's bits, this function should
159 void (*read
) (struct value
*v
);
161 /* Handle an assignment TOVAL = FROMVAL by writing the value of
162 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
163 been updated. If a problem arises in doing so, this function
164 should call 'error'. */
165 void (*write
) (struct value
*toval
, struct value
*fromval
);
167 /* Return a duplicate of VALUE's closure, for use in a new value.
168 This may simply return the same closure, if VALUE's is
169 reference-counted or statically allocated.
171 This may be NULL, in which case VALUE's closure is re-used in the
173 void *(*copy_closure
) (struct value
*v
);
175 /* Drop VALUE's reference to its closure. Maybe this frees the
176 closure; maybe this decrements a reference count; maybe the
177 closure is statically allocated and this does nothing.
179 This may be NULL, in which case no action is taken to free
181 void (*free_closure
) (struct value
*v
);
184 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
185 and closure CLOSURE. */
187 extern struct value
*allocate_computed_value (struct type
*type
,
188 struct lval_funcs
*funcs
,
191 /* If VALUE is lval_computed, return its lval_funcs structure. */
193 extern struct lval_funcs
*value_computed_funcs (struct value
*value
);
195 /* If VALUE is lval_computed, return its closure. The meaning of the
196 returned value depends on the functions VALUE uses. */
198 extern void *value_computed_closure (struct value
*value
);
200 /* If zero, contents of this value are in the contents field. If
201 nonzero, contents are in inferior. If the lval field is lval_memory,
202 the contents are in inferior memory at location.address plus offset.
203 The lval field may also be lval_register.
205 WARNING: This field is used by the code which handles watchpoints
206 (see breakpoint.c) to decide whether a particular value can be
207 watched by hardware watchpoints. If the lazy flag is set for some
208 member of a value chain, it is assumed that this member of the
209 chain doesn't need to be watched as part of watching the value
210 itself. This is how GDB avoids watching the entire struct or array
211 when the user wants to watch a single struct member or array
212 element. If you ever change the way lazy flag is set and reset, be
213 sure to consider this use as well! */
215 extern int value_lazy (struct value
*);
216 extern void set_value_lazy (struct value
*value
, int val
);
218 /* value_contents() and value_contents_raw() both return the address
219 of the gdb buffer used to hold a copy of the contents of the lval.
220 value_contents() is used when the contents of the buffer are needed
221 -- it uses value_fetch_lazy() to load the buffer from the process
222 being debugged if it hasn't already been loaded
223 (value_contents_writeable() is used when a writeable but fetched
224 buffer is required).. value_contents_raw() is used when data is
225 being stored into the buffer, or when it is certain that the
226 contents of the buffer are valid.
228 Note: The contents pointer is adjusted by the offset required to
229 get to the real subobject, if the value happens to represent
230 something embedded in a larger run-time object. */
232 extern gdb_byte
*value_contents_raw (struct value
*);
234 /* Actual contents of the value. For use of this value; setting it
235 uses the stuff above. Not valid if lazy is nonzero. Target
236 byte-order. We force it to be aligned properly for any possible
237 value. Note that a value therefore extends beyond what is
240 extern const gdb_byte
*value_contents (struct value
*);
241 extern gdb_byte
*value_contents_writeable (struct value
*);
243 /* The ALL variants of the above two macros do not adjust the returned
244 pointer by the embedded_offset value. */
246 extern gdb_byte
*value_contents_all_raw (struct value
*);
247 extern const gdb_byte
*value_contents_all (struct value
*);
249 extern int value_fetch_lazy (struct value
*val
);
250 extern int value_contents_equal (struct value
*val1
, struct value
*val2
);
252 /* If nonzero, this is the value of a variable which does not actually
253 exist in the program. */
254 extern int value_optimized_out (struct value
*value
);
255 extern void set_value_optimized_out (struct value
*value
, int val
);
257 /* Set or return field indicating whether a variable is initialized or
258 not, based on debugging information supplied by the compiler.
259 1 = initialized; 0 = uninitialized. */
260 extern int value_initialized (struct value
*);
261 extern void set_value_initialized (struct value
*, int);
263 /* Set COMPONENT's location as appropriate for a component of WHOLE
264 --- regardless of what kind of lvalue WHOLE is. */
265 extern void set_value_component_location (struct value
*component
,
266 struct value
*whole
);
268 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
269 single value might have multiple LVALs), this hacked interface is
270 limited to just the first PIECE. Expect further change. */
271 /* Type of value; either not an lval, or one of the various different
272 possible kinds of lval. */
273 extern enum lval_type
*deprecated_value_lval_hack (struct value
*);
274 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
276 /* If lval == lval_memory, return the address in the inferior. If
277 lval == lval_register, return the byte offset into the registers
278 structure. Otherwise, return 0. The returned address
279 includes the offset, if any. */
280 extern CORE_ADDR
value_address (struct value
*);
282 /* Like value_address, except the result does not include value's
284 extern CORE_ADDR
value_raw_address (struct value
*);
286 /* Set the address of a value. */
287 extern void set_value_address (struct value
*, CORE_ADDR
);
289 /* Pointer to internal variable. */
290 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
291 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
293 /* Frame register value is relative to. This will be described in the
294 lval enum above as "lval_register". */
295 extern struct frame_id
*deprecated_value_frame_id_hack (struct value
*);
296 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
298 /* Register number if the value is from a register. */
299 extern short *deprecated_value_regnum_hack (struct value
*);
300 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
302 /* Convert a REF to the object referenced. */
304 extern struct value
*coerce_ref (struct value
*value
);
306 /* If ARG is an array, convert it to a pointer.
307 If ARG is a function, convert it to a function pointer.
309 References are dereferenced. */
311 extern struct value
*coerce_array (struct value
*value
);
316 #include "gdbtypes.h"
317 #include "expression.h"
322 extern void print_address_demangle (struct gdbarch
*, CORE_ADDR
,
323 struct ui_file
*, int);
325 extern LONGEST
value_as_long (struct value
*val
);
326 extern DOUBLEST
value_as_double (struct value
*val
);
327 extern CORE_ADDR
value_as_address (struct value
*val
);
329 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
330 extern DOUBLEST
unpack_double (struct type
*type
, const gdb_byte
*valaddr
,
332 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
333 LONGEST
unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
334 int bitpos
, int bitsize
);
335 extern LONGEST
unpack_field_as_long (struct type
*type
,
336 const gdb_byte
*valaddr
,
339 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
341 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
342 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
343 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
344 extern struct value
*value_from_decfloat (struct type
*type
,
345 const gdb_byte
*decbytes
);
347 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
348 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
350 extern struct value
*value_from_contents_and_address (struct type
*,
354 extern struct value
*default_value_from_register (struct type
*type
,
356 struct frame_info
*frame
);
358 extern struct value
*value_from_register (struct type
*type
, int regnum
,
359 struct frame_info
*frame
);
361 extern CORE_ADDR
address_from_register (struct type
*type
, int regnum
,
362 struct frame_info
*frame
);
364 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
366 extern struct value
*address_of_variable (struct symbol
*var
, struct block
*b
);
368 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
370 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
372 extern int symbol_read_needs_frame (struct symbol
*);
374 extern struct value
*read_var_value (struct symbol
*var
,
375 struct frame_info
*frame
);
377 extern struct value
*allocate_value (struct type
*type
);
378 extern struct value
*allocate_value_lazy (struct type
*type
);
379 extern void allocate_value_contents (struct value
*value
);
381 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
383 extern struct value
*value_mark (void);
385 extern void value_free_to_mark (struct value
*mark
);
387 extern struct value
*value_cstring (char *ptr
, int len
,
388 struct type
*char_type
);
389 extern struct value
*value_string (char *ptr
, int len
,
390 struct type
*char_type
);
391 extern struct value
*value_bitstring (char *ptr
, int len
,
392 struct type
*index_type
);
394 extern struct value
*value_array (int lowbound
, int highbound
,
395 struct value
**elemvec
);
397 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
399 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
402 extern struct value
*value_ptradd (struct value
*arg1
, LONGEST arg2
);
404 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
406 extern int value_must_coerce_to_target (struct value
*arg1
);
408 extern struct value
*value_coerce_to_target (struct value
*arg1
);
410 extern struct value
*value_coerce_array (struct value
*arg1
);
412 extern struct value
*value_coerce_function (struct value
*arg1
);
414 extern struct value
*value_ind (struct value
*arg1
);
416 extern struct value
*value_addr (struct value
*arg1
);
418 extern struct value
*value_ref (struct value
*arg1
);
420 extern struct value
*value_assign (struct value
*toval
,
421 struct value
*fromval
);
423 extern struct value
*value_pos (struct value
*arg1
);
425 extern struct value
*value_neg (struct value
*arg1
);
427 extern struct value
*value_complement (struct value
*arg1
);
429 extern struct value
*value_struct_elt (struct value
**argp
,
431 char *name
, int *static_memfuncp
,
434 extern struct value
*value_aggregate_elt (struct type
*curtype
,
439 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
441 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
443 struct type
**, int *);
445 extern int find_overload_match (struct type
**arg_types
, int nargs
,
446 char *name
, int method
, int lax
,
447 struct value
**objp
, struct symbol
*fsym
,
448 struct value
**valp
, struct symbol
**symp
,
451 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
453 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
455 struct type
*arg_type
);
458 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
461 extern struct value
*value_full_object (struct value
*, struct type
*, int,
464 extern struct value
*value_cast_pointers (struct type
*, struct value
*);
466 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
468 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
470 extern struct value
*value_one (struct type
*type
, enum lval_type lv
);
472 extern struct value
*value_repeat (struct value
*arg1
, int count
);
474 extern struct value
*value_subscript (struct value
*array
, LONGEST index
);
476 extern struct value
*value_bitstring_subscript (struct type
*type
,
477 struct value
*bitstring
,
480 extern struct value
*register_value_being_returned (struct type
*valtype
,
481 struct regcache
*retbuf
);
483 extern int value_in (struct value
*element
, struct value
*set
);
485 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
488 extern int using_struct_return (struct gdbarch
*gdbarch
,
489 struct type
*func_type
,
490 struct type
*value_type
);
492 extern struct value
*evaluate_expression (struct expression
*exp
);
494 extern struct value
*evaluate_type (struct expression
*exp
);
496 extern struct value
*evaluate_subexp (struct type
*expect_type
,
497 struct expression
*exp
,
498 int *pos
, enum noside noside
);
500 extern struct value
*evaluate_subexpression_type (struct expression
*exp
,
503 extern char *extract_field_op (struct expression
*exp
, int *subexp
);
505 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
508 extern struct value
*parse_and_eval (char *exp
);
510 extern struct value
*parse_to_comma_and_eval (char **expp
);
512 extern struct type
*parse_and_eval_type (char *p
, int length
);
514 extern CORE_ADDR
parse_and_eval_address (char *exp
);
516 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
518 extern LONGEST
parse_and_eval_long (char *exp
);
520 extern void unop_promote (const struct language_defn
*language
,
521 struct gdbarch
*gdbarch
,
522 struct value
**arg1
);
524 extern void binop_promote (const struct language_defn
*language
,
525 struct gdbarch
*gdbarch
,
526 struct value
**arg1
, struct value
**arg2
);
528 extern struct value
*access_value_history (int num
);
530 extern struct value
*value_of_internalvar (struct gdbarch
*gdbarch
,
531 struct internalvar
*var
);
533 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
535 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
537 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
539 extern void set_internalvar_string (struct internalvar
*var
,
542 extern void clear_internalvar (struct internalvar
*var
);
544 extern void set_internalvar_component (struct internalvar
*var
,
546 int bitpos
, int bitsize
,
547 struct value
*newvalue
);
549 extern struct internalvar
*lookup_only_internalvar (const char *name
);
551 extern struct internalvar
*create_internalvar (const char *name
);
553 typedef struct value
* (*internalvar_make_value
) (struct gdbarch
*,
554 struct internalvar
*);
555 extern struct internalvar
*
556 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
);
558 extern struct internalvar
*lookup_internalvar (const char *name
);
560 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
562 extern int value_less (struct value
*arg1
, struct value
*arg2
);
564 extern int value_logical_not (struct value
*arg1
);
568 extern struct value
*value_of_this (int complain
);
570 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
572 enum exp_opcode otherop
,
575 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
578 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
579 int j
, struct type
*type
, int offset
);
581 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
584 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
586 extern int destructor_name_p (const char *name
, const struct type
*type
);
588 extern void value_incref (struct value
*val
);
590 extern void value_free (struct value
*val
);
592 extern void free_all_values (void);
594 extern void release_value (struct value
*val
);
596 extern int record_latest_value (struct value
*val
);
598 extern void modify_field (struct type
*type
, gdb_byte
*addr
,
599 LONGEST fieldval
, int bitpos
, int bitsize
);
601 extern void type_print (struct type
*type
, char *varstring
,
602 struct ui_file
*stream
, int show
);
604 extern char *type_to_string (struct type
*type
);
606 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
608 struct value
**valuep
, int *errp
);
610 extern void print_longest (struct ui_file
*stream
, int format
,
611 int use_local
, LONGEST val
);
613 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
614 struct ui_file
*stream
);
616 extern void print_decimal_floating (const gdb_byte
*valaddr
, struct type
*type
,
617 struct ui_file
*stream
);
619 extern int value_print (struct value
*val
, struct ui_file
*stream
,
620 const struct value_print_options
*options
);
622 extern void value_print_array_elements (struct value
*val
,
623 struct ui_file
*stream
, int format
,
624 enum val_prettyprint pretty
);
626 extern struct value
*value_release_to_mark (struct value
*mark
);
628 extern int val_print (struct type
*type
, const gdb_byte
*valaddr
,
629 int embedded_offset
, CORE_ADDR address
,
630 struct ui_file
*stream
, int recurse
,
631 const struct value_print_options
*options
,
632 const struct language_defn
*language
);
634 extern int common_val_print (struct value
*val
,
635 struct ui_file
*stream
, int recurse
,
636 const struct value_print_options
*options
,
637 const struct language_defn
*language
);
639 extern int val_print_string (struct type
*elttype
, CORE_ADDR addr
, int len
,
640 struct ui_file
*stream
,
641 const struct value_print_options
*options
);
643 extern void print_variable_and_value (const char *name
,
645 struct frame_info
*frame
,
646 struct ui_file
*stream
,
649 extern int check_field (struct type
*, const char *);
651 extern void typedef_print (struct type
*type
, struct symbol
*news
,
652 struct ui_file
*stream
);
654 extern char *internalvar_name (struct internalvar
*var
);
656 extern void preserve_values (struct objfile
*);
660 extern struct value
*value_copy (struct value
*);
662 extern void preserve_one_value (struct value
*, struct objfile
*, htab_t
);
666 extern struct value
*varying_to_slice (struct value
*);
668 extern struct value
*value_slice (struct value
*, int, int);
670 extern struct value
*value_literal_complex (struct value
*, struct value
*,
673 extern struct value
*find_function_in_inferior (const char *,
676 extern struct value
*value_allocate_space_in_inferior (int);
678 extern struct value
*value_of_local (const char *name
, int complain
);
680 extern struct value
*value_subscripted_rvalue (struct value
*array
,
681 LONGEST index
, int lowerbound
);
683 /* User function handler. */
685 typedef struct value
*(*internal_function_fn
) (struct gdbarch
*gdbarch
,
686 const struct language_defn
*language
,
689 struct value
**argv
);
691 void add_internal_function (const char *name
, const char *doc
,
692 internal_function_fn handler
,
695 struct value
*call_internal_function (struct gdbarch
*gdbarch
,
696 const struct language_defn
*language
,
697 struct value
*function
,
698 int argc
, struct value
**argv
);
700 char *value_internal_function_name (struct value
*);
702 #endif /* !defined (VALUE_H) */