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 extern int value_stack (struct value
*);
219 extern void set_value_stack (struct value
*value
, int val
);
221 /* value_contents() and value_contents_raw() both return the address
222 of the gdb buffer used to hold a copy of the contents of the lval.
223 value_contents() is used when the contents of the buffer are needed
224 -- it uses value_fetch_lazy() to load the buffer from the process
225 being debugged if it hasn't already been loaded
226 (value_contents_writeable() is used when a writeable but fetched
227 buffer is required).. value_contents_raw() is used when data is
228 being stored into the buffer, or when it is certain that the
229 contents of the buffer are valid.
231 Note: The contents pointer is adjusted by the offset required to
232 get to the real subobject, if the value happens to represent
233 something embedded in a larger run-time object. */
235 extern gdb_byte
*value_contents_raw (struct value
*);
237 /* Actual contents of the value. For use of this value; setting it
238 uses the stuff above. Not valid if lazy is nonzero. Target
239 byte-order. We force it to be aligned properly for any possible
240 value. Note that a value therefore extends beyond what is
243 extern const gdb_byte
*value_contents (struct value
*);
244 extern gdb_byte
*value_contents_writeable (struct value
*);
246 /* The ALL variants of the above two macros do not adjust the returned
247 pointer by the embedded_offset value. */
249 extern gdb_byte
*value_contents_all_raw (struct value
*);
250 extern const gdb_byte
*value_contents_all (struct value
*);
252 extern int value_fetch_lazy (struct value
*val
);
253 extern int value_contents_equal (struct value
*val1
, struct value
*val2
);
255 /* If nonzero, this is the value of a variable which does not actually
256 exist in the program. */
257 extern int value_optimized_out (struct value
*value
);
258 extern void set_value_optimized_out (struct value
*value
, int val
);
260 /* Set or return field indicating whether a variable is initialized or
261 not, based on debugging information supplied by the compiler.
262 1 = initialized; 0 = uninitialized. */
263 extern int value_initialized (struct value
*);
264 extern void set_value_initialized (struct value
*, int);
266 /* Set COMPONENT's location as appropriate for a component of WHOLE
267 --- regardless of what kind of lvalue WHOLE is. */
268 extern void set_value_component_location (struct value
*component
,
269 struct value
*whole
);
271 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
272 single value might have multiple LVALs), this hacked interface is
273 limited to just the first PIECE. Expect further change. */
274 /* Type of value; either not an lval, or one of the various different
275 possible kinds of lval. */
276 extern enum lval_type
*deprecated_value_lval_hack (struct value
*);
277 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
279 /* If lval == lval_memory, return the address in the inferior. If
280 lval == lval_register, return the byte offset into the registers
281 structure. Otherwise, return 0. The returned address
282 includes the offset, if any. */
283 extern CORE_ADDR
value_address (struct value
*);
285 /* Like value_address, except the result does not include value's
287 extern CORE_ADDR
value_raw_address (struct value
*);
289 /* Set the address of a value. */
290 extern void set_value_address (struct value
*, CORE_ADDR
);
292 /* Pointer to internal variable. */
293 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
294 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
296 /* Frame register value is relative to. This will be described in the
297 lval enum above as "lval_register". */
298 extern struct frame_id
*deprecated_value_frame_id_hack (struct value
*);
299 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
301 /* Register number if the value is from a register. */
302 extern short *deprecated_value_regnum_hack (struct value
*);
303 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
305 /* Convert a REF to the object referenced. */
307 extern struct value
*coerce_ref (struct value
*value
);
309 /* If ARG is an array, convert it to a pointer.
310 If ARG is a function, convert it to a function pointer.
312 References are dereferenced. */
314 extern struct value
*coerce_array (struct value
*value
);
319 #include "gdbtypes.h"
320 #include "expression.h"
325 extern void print_address_demangle (struct gdbarch
*, CORE_ADDR
,
326 struct ui_file
*, int);
328 extern LONGEST
value_as_long (struct value
*val
);
329 extern DOUBLEST
value_as_double (struct value
*val
);
330 extern CORE_ADDR
value_as_address (struct value
*val
);
332 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
333 extern DOUBLEST
unpack_double (struct type
*type
, const gdb_byte
*valaddr
,
335 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
336 LONGEST
unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
337 int bitpos
, int bitsize
);
338 extern LONGEST
unpack_field_as_long (struct type
*type
,
339 const gdb_byte
*valaddr
,
342 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
344 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
345 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
346 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
347 extern struct value
*value_from_decfloat (struct type
*type
,
348 const gdb_byte
*decbytes
);
350 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
351 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
353 extern struct value
*value_from_contents_and_address (struct type
*,
357 extern struct value
*default_value_from_register (struct type
*type
,
359 struct frame_info
*frame
);
361 extern struct value
*value_from_register (struct type
*type
, int regnum
,
362 struct frame_info
*frame
);
364 extern CORE_ADDR
address_from_register (struct type
*type
, int regnum
,
365 struct frame_info
*frame
);
367 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
369 extern struct value
*address_of_variable (struct symbol
*var
, struct block
*b
);
371 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
373 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
375 extern int symbol_read_needs_frame (struct symbol
*);
377 extern struct value
*read_var_value (struct symbol
*var
,
378 struct frame_info
*frame
);
380 extern struct value
*allocate_value (struct type
*type
);
381 extern struct value
*allocate_value_lazy (struct type
*type
);
382 extern void allocate_value_contents (struct value
*value
);
384 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
386 extern struct value
*value_mark (void);
388 extern void value_free_to_mark (struct value
*mark
);
390 extern struct value
*value_cstring (char *ptr
, int len
,
391 struct type
*char_type
);
392 extern struct value
*value_string (char *ptr
, int len
,
393 struct type
*char_type
);
394 extern struct value
*value_bitstring (char *ptr
, int len
,
395 struct type
*index_type
);
397 extern struct value
*value_array (int lowbound
, int highbound
,
398 struct value
**elemvec
);
400 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
402 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
405 extern struct value
*value_ptradd (struct value
*arg1
, LONGEST arg2
);
407 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
409 extern int value_must_coerce_to_target (struct value
*arg1
);
411 extern struct value
*value_coerce_to_target (struct value
*arg1
);
413 extern struct value
*value_coerce_array (struct value
*arg1
);
415 extern struct value
*value_coerce_function (struct value
*arg1
);
417 extern struct value
*value_ind (struct value
*arg1
);
419 extern struct value
*value_addr (struct value
*arg1
);
421 extern struct value
*value_ref (struct value
*arg1
);
423 extern struct value
*value_assign (struct value
*toval
,
424 struct value
*fromval
);
426 extern struct value
*value_pos (struct value
*arg1
);
428 extern struct value
*value_neg (struct value
*arg1
);
430 extern struct value
*value_complement (struct value
*arg1
);
432 extern struct value
*value_struct_elt (struct value
**argp
,
434 char *name
, int *static_memfuncp
,
437 extern struct value
*value_aggregate_elt (struct type
*curtype
,
439 struct type
*expect_type
,
443 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
445 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
447 struct type
**, int *);
449 extern int find_overload_match (struct type
**arg_types
, int nargs
,
450 char *name
, int method
, int lax
,
451 struct value
**objp
, struct symbol
*fsym
,
452 struct value
**valp
, struct symbol
**symp
,
455 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
457 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
459 struct type
*arg_type
);
462 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
465 extern struct value
*value_full_object (struct value
*, struct type
*, int,
468 extern struct value
*value_cast_pointers (struct type
*, struct value
*);
470 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
472 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
474 extern struct value
*value_one (struct type
*type
, enum lval_type lv
);
476 extern struct value
*value_repeat (struct value
*arg1
, int count
);
478 extern struct value
*value_subscript (struct value
*array
, LONGEST index
);
480 extern struct value
*value_bitstring_subscript (struct type
*type
,
481 struct value
*bitstring
,
484 extern struct value
*register_value_being_returned (struct type
*valtype
,
485 struct regcache
*retbuf
);
487 extern int value_in (struct value
*element
, struct value
*set
);
489 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
492 extern int using_struct_return (struct gdbarch
*gdbarch
,
493 struct type
*func_type
,
494 struct type
*value_type
);
496 extern struct value
*evaluate_expression (struct expression
*exp
);
498 extern struct value
*evaluate_type (struct expression
*exp
);
500 extern struct value
*evaluate_subexp (struct type
*expect_type
,
501 struct expression
*exp
,
502 int *pos
, enum noside noside
);
504 extern struct value
*evaluate_subexpression_type (struct expression
*exp
,
507 extern char *extract_field_op (struct expression
*exp
, int *subexp
);
509 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
512 extern struct value
*parse_and_eval (char *exp
);
514 extern struct value
*parse_to_comma_and_eval (char **expp
);
516 extern struct type
*parse_and_eval_type (char *p
, int length
);
518 extern CORE_ADDR
parse_and_eval_address (char *exp
);
520 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
522 extern LONGEST
parse_and_eval_long (char *exp
);
524 extern void unop_promote (const struct language_defn
*language
,
525 struct gdbarch
*gdbarch
,
526 struct value
**arg1
);
528 extern void binop_promote (const struct language_defn
*language
,
529 struct gdbarch
*gdbarch
,
530 struct value
**arg1
, struct value
**arg2
);
532 extern struct value
*access_value_history (int num
);
534 extern struct value
*value_of_internalvar (struct gdbarch
*gdbarch
,
535 struct internalvar
*var
);
537 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
539 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
541 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
543 extern void set_internalvar_string (struct internalvar
*var
,
546 extern void clear_internalvar (struct internalvar
*var
);
548 extern void set_internalvar_component (struct internalvar
*var
,
550 int bitpos
, int bitsize
,
551 struct value
*newvalue
);
553 extern struct internalvar
*lookup_only_internalvar (const char *name
);
555 extern struct internalvar
*create_internalvar (const char *name
);
557 typedef struct value
* (*internalvar_make_value
) (struct gdbarch
*,
558 struct internalvar
*);
559 extern struct internalvar
*
560 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
);
562 extern struct internalvar
*lookup_internalvar (const char *name
);
564 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
566 extern int value_less (struct value
*arg1
, struct value
*arg2
);
568 extern int value_logical_not (struct value
*arg1
);
572 extern struct value
*value_of_this (int complain
);
574 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
576 enum exp_opcode otherop
,
579 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
582 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
583 int j
, struct type
*type
, int offset
);
585 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
588 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
590 extern int destructor_name_p (const char *name
, const struct type
*type
);
592 extern void value_incref (struct value
*val
);
594 extern void value_free (struct value
*val
);
596 extern void free_all_values (void);
598 extern void release_value (struct value
*val
);
600 extern int record_latest_value (struct value
*val
);
602 extern void modify_field (struct type
*type
, gdb_byte
*addr
,
603 LONGEST fieldval
, int bitpos
, int bitsize
);
605 extern void type_print (struct type
*type
, char *varstring
,
606 struct ui_file
*stream
, int show
);
608 extern char *type_to_string (struct type
*type
);
610 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
612 struct value
**valuep
, int *errp
);
614 extern void print_longest (struct ui_file
*stream
, int format
,
615 int use_local
, LONGEST val
);
617 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
618 struct ui_file
*stream
);
620 extern void print_decimal_floating (const gdb_byte
*valaddr
, struct type
*type
,
621 struct ui_file
*stream
);
623 extern int value_print (struct value
*val
, struct ui_file
*stream
,
624 const struct value_print_options
*options
);
626 extern void value_print_array_elements (struct value
*val
,
627 struct ui_file
*stream
, int format
,
628 enum val_prettyprint pretty
);
630 extern struct value
*value_release_to_mark (struct value
*mark
);
632 extern int val_print (struct type
*type
, const gdb_byte
*valaddr
,
633 int embedded_offset
, CORE_ADDR address
,
634 struct ui_file
*stream
, int recurse
,
635 const struct value_print_options
*options
,
636 const struct language_defn
*language
);
638 extern int common_val_print (struct value
*val
,
639 struct ui_file
*stream
, int recurse
,
640 const struct value_print_options
*options
,
641 const struct language_defn
*language
);
643 extern int val_print_string (struct type
*elttype
, CORE_ADDR addr
, int len
,
644 struct ui_file
*stream
,
645 const struct value_print_options
*options
);
647 extern void print_variable_and_value (const char *name
,
649 struct frame_info
*frame
,
650 struct ui_file
*stream
,
653 extern int check_field (struct type
*, const char *);
655 extern void typedef_print (struct type
*type
, struct symbol
*news
,
656 struct ui_file
*stream
);
658 extern char *internalvar_name (struct internalvar
*var
);
660 extern void preserve_values (struct objfile
*);
664 extern struct value
*value_copy (struct value
*);
666 extern void preserve_one_value (struct value
*, struct objfile
*, htab_t
);
670 extern struct value
*varying_to_slice (struct value
*);
672 extern struct value
*value_slice (struct value
*, int, int);
674 extern struct value
*value_literal_complex (struct value
*, struct value
*,
677 extern struct value
*find_function_in_inferior (const char *,
680 extern struct value
*value_allocate_space_in_inferior (int);
682 extern struct value
*value_of_local (const char *name
, int complain
);
684 extern struct value
*value_subscripted_rvalue (struct value
*array
,
685 LONGEST index
, int lowerbound
);
687 /* User function handler. */
689 typedef struct value
*(*internal_function_fn
) (struct gdbarch
*gdbarch
,
690 const struct language_defn
*language
,
693 struct value
**argv
);
695 void add_internal_function (const char *name
, const char *doc
,
696 internal_function_fn handler
,
699 struct value
*call_internal_function (struct gdbarch
*gdbarch
,
700 const struct language_defn
*language
,
701 struct value
*function
,
702 int argc
, struct value
**argv
);
704 char *value_internal_function_name (struct value
*);
706 #endif /* !defined (VALUE_H) */