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 /* Needed if another module needs to maintain its own list of values. */
46 void value_prepend_to_list (struct value
**head
, struct value
*val
);
47 void value_remove_from_list (struct value
**head
, struct value
*val
);
49 /* Values are stored in a chain, so that they can be deleted easily
50 over calls to the inferior. Values assigned to internal variables,
51 put into the value history or exposed to Python are taken off this
54 struct value
*value_next (struct value
*);
56 /* Type of the value. */
58 extern struct type
*value_type (struct value
*);
60 /* This is being used to change the type of an existing value, that
61 code should instead be creating a new value with the changed type
62 (but possibly shared content). */
64 extern void deprecated_set_value_type (struct value
*value
,
67 /* Only used for bitfields; number of bits contained in them. */
69 extern int value_bitsize (struct value
*);
70 extern void set_value_bitsize (struct value
*, int bit
);
72 /* Only used for bitfields; position of start of field. For
73 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
74 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
76 extern int value_bitpos (struct value
*);
77 extern void set_value_bitpos (struct value
*, int bit
);
79 /* Describes offset of a value within lval of a structure in bytes.
80 If lval == lval_memory, this is an offset to the address. If lval
81 == lval_register, this is a further offset from location.address
82 within the registers structure. Note also the member
83 embedded_offset below. */
85 extern int value_offset (struct value
*);
86 extern void set_value_offset (struct value
*, int offset
);
88 /* The comment from "struct value" reads: ``Is it modifiable? Only
89 relevant if lval != not_lval.''. Shouldn't the value instead be
90 not_lval and be done with it? */
92 extern int deprecated_value_modifiable (struct value
*value
);
93 extern void deprecated_set_value_modifiable (struct value
*value
,
96 /* If a value represents a C++ object, then the `type' field gives the
97 object's compile-time type. If the object actually belongs to some
98 class derived from `type', perhaps with other base classes and
99 additional members, then `type' is just a subobject of the real
100 thing, and the full object is probably larger than `type' would
103 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
104 actually determine the object's run-time type by looking at the
105 run-time type information in the vtable. When this information is
106 available, we may elect to read in the entire object, for several
109 - When printing the value, the user would probably rather see the
110 full object, not just the limited portion apparent from the
113 - If `type' has virtual base classes, then even printing `type'
114 alone may require reaching outside the `type' portion of the
115 object to wherever the virtual base class has been stored.
117 When we store the entire object, `enclosing_type' is the run-time
118 type -- the complete object -- and `embedded_offset' is the offset
119 of `type' within that larger type, in bytes. The value_contents()
120 macro takes `embedded_offset' into account, so most GDB code
121 continues to see the `type' portion of the value, just as the
124 If `type' is a pointer to an object, then `enclosing_type' is a
125 pointer to the object's run-time type, and `pointed_to_offset' is
126 the offset in bytes from the full object to the pointed-to object
127 -- that is, the value `embedded_offset' would have if we followed
128 the pointer and fetched the complete object. (I don't really see
129 the point. Why not just determine the run-time type when you
130 indirect, and avoid the special case? The contents don't matter
131 until you indirect anyway.)
133 If we're not doing anything fancy, `enclosing_type' is equal to
134 `type', and `embedded_offset' is zero, so everything works
137 extern struct type
*value_enclosing_type (struct value
*);
138 extern struct value
*value_change_enclosing_type (struct value
*val
,
139 struct type
*new_type
);
140 extern int value_pointed_to_offset (struct value
*value
);
141 extern void set_value_pointed_to_offset (struct value
*value
, int val
);
142 extern int value_embedded_offset (struct value
*value
);
143 extern void set_value_embedded_offset (struct value
*value
, int val
);
145 /* For lval_computed values, this structure holds functions used to
146 retrieve and set the value (or portions of the value).
148 For each function, 'V' is the 'this' pointer: an lval_funcs
149 function F may always assume that the V it receives is an
150 lval_computed value, and has F in the appropriate slot of its
151 lval_funcs structure. */
155 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
156 a problem arises in obtaining VALUE's bits, this function should
158 void (*read
) (struct value
*v
);
160 /* Handle an assignment TOVAL = FROMVAL by writing the value of
161 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
162 been updated. If a problem arises in doing so, this function
163 should call 'error'. */
164 void (*write
) (struct value
*toval
, struct value
*fromval
);
166 /* Return a duplicate of VALUE's closure, for use in a new value.
167 This may simply return the same closure, if VALUE's is
168 reference-counted or statically allocated.
170 This may be NULL, in which case VALUE's closure is re-used in the
172 void *(*copy_closure
) (struct value
*v
);
174 /* Drop VALUE's reference to its closure. Maybe this frees the
175 closure; maybe this decrements a reference count; maybe the
176 closure is statically allocated and this does nothing.
178 This may be NULL, in which case no action is taken to free
180 void (*free_closure
) (struct value
*v
);
183 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
184 and closure CLOSURE. */
186 extern struct value
*allocate_computed_value (struct type
*type
,
187 struct lval_funcs
*funcs
,
190 /* If VALUE is lval_computed, return its lval_funcs structure. */
192 extern struct lval_funcs
*value_computed_funcs (struct value
*value
);
194 /* If VALUE is lval_computed, return its closure. The meaning of the
195 returned value depends on the functions VALUE uses. */
197 extern void *value_computed_closure (struct value
*value
);
199 /* If zero, contents of this value are in the contents field. If
200 nonzero, contents are in inferior. If the lval field is lval_memory,
201 the contents are in inferior memory at location.address plus offset.
202 The lval field may also be lval_register.
204 WARNING: This field is used by the code which handles watchpoints
205 (see breakpoint.c) to decide whether a particular value can be
206 watched by hardware watchpoints. If the lazy flag is set for some
207 member of a value chain, it is assumed that this member of the
208 chain doesn't need to be watched as part of watching the value
209 itself. This is how GDB avoids watching the entire struct or array
210 when the user wants to watch a single struct member or array
211 element. If you ever change the way lazy flag is set and reset, be
212 sure to consider this use as well! */
214 extern int value_lazy (struct value
*);
215 extern void set_value_lazy (struct value
*value
, int val
);
217 /* value_contents() and value_contents_raw() both return the address
218 of the gdb buffer used to hold a copy of the contents of the lval.
219 value_contents() is used when the contents of the buffer are needed
220 -- it uses value_fetch_lazy() to load the buffer from the process
221 being debugged if it hasn't already been loaded
222 (value_contents_writeable() is used when a writeable but fetched
223 buffer is required).. value_contents_raw() is used when data is
224 being stored into the buffer, or when it is certain that the
225 contents of the buffer are valid.
227 Note: The contents pointer is adjusted by the offset required to
228 get to the real subobject, if the value happens to represent
229 something embedded in a larger run-time object. */
231 extern gdb_byte
*value_contents_raw (struct value
*);
233 /* Actual contents of the value. For use of this value; setting it
234 uses the stuff above. Not valid if lazy is nonzero. Target
235 byte-order. We force it to be aligned properly for any possible
236 value. Note that a value therefore extends beyond what is
239 extern const gdb_byte
*value_contents (struct value
*);
240 extern gdb_byte
*value_contents_writeable (struct value
*);
242 /* The ALL variants of the above two macros do not adjust the returned
243 pointer by the embedded_offset value. */
245 extern gdb_byte
*value_contents_all_raw (struct value
*);
246 extern const gdb_byte
*value_contents_all (struct value
*);
248 extern int value_fetch_lazy (struct value
*val
);
249 extern int value_contents_equal (struct value
*val1
, struct value
*val2
);
251 /* If nonzero, this is the value of a variable which does not actually
252 exist in the program. */
253 extern int value_optimized_out (struct value
*value
);
254 extern void set_value_optimized_out (struct value
*value
, int val
);
256 /* Set or return field indicating whether a variable is initialized or
257 not, based on debugging information supplied by the compiler.
258 1 = initialized; 0 = uninitialized. */
259 extern int value_initialized (struct value
*);
260 extern void set_value_initialized (struct value
*, int);
262 /* Set COMPONENT's location as appropriate for a component of WHOLE
263 --- regardless of what kind of lvalue WHOLE is. */
264 extern void set_value_component_location (struct value
*component
,
265 struct value
*whole
);
267 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
268 single value might have multiple LVALs), this hacked interface is
269 limited to just the first PIECE. Expect further change. */
270 /* Type of value; either not an lval, or one of the various different
271 possible kinds of lval. */
272 extern enum lval_type
*deprecated_value_lval_hack (struct value
*);
273 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
275 /* If lval == lval_memory, this is the address in the inferior. If
276 lval == lval_register, this is the byte offset into the registers
278 extern CORE_ADDR
*deprecated_value_address_hack (struct value
*);
279 #define VALUE_ADDRESS(val) (*deprecated_value_address_hack (val))
281 /* Pointer to internal variable. */
282 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
283 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
285 /* Frame register value is relative to. This will be described in the
286 lval enum above as "lval_register". */
287 extern struct frame_id
*deprecated_value_frame_id_hack (struct value
*);
288 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
290 /* Register number if the value is from a register. */
291 extern short *deprecated_value_regnum_hack (struct value
*);
292 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
294 /* Convert a REF to the object referenced. */
296 extern struct value
*coerce_ref (struct value
*value
);
298 /* If ARG is an array, convert it to a pointer.
299 If ARG is a function, convert it to a function pointer.
301 References are dereferenced. */
303 extern struct value
*coerce_array (struct value
*value
);
305 /* Internal variables (variables for convenience of use of debugger)
306 are recorded as a chain of these structures. */
308 typedef struct value
* (*internalvar_make_value
) (struct internalvar
*);
312 struct internalvar
*next
;
315 internalvar_make_value make_value
;
317 /* True if this internalvar is the canonical name for a convenience
325 #include "gdbtypes.h"
326 #include "expression.h"
331 extern void print_address_demangle (CORE_ADDR
, struct ui_file
*, int);
333 extern LONGEST
value_as_long (struct value
*val
);
334 extern DOUBLEST
value_as_double (struct value
*val
);
335 extern CORE_ADDR
value_as_address (struct value
*val
);
337 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
338 extern DOUBLEST
unpack_double (struct type
*type
, const gdb_byte
*valaddr
,
340 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
341 extern LONGEST
unpack_field_as_long (struct type
*type
,
342 const gdb_byte
*valaddr
,
345 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
347 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
348 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
349 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
350 extern struct value
*value_from_decfloat (struct type
*type
,
351 const gdb_byte
*decbytes
);
352 extern struct value
*value_from_string (char *string
);
354 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
355 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
357 extern struct value
*value_from_contents_and_address (struct type
*,
361 extern struct value
*default_value_from_register (struct type
*type
,
363 struct frame_info
*frame
);
365 extern struct value
*value_from_register (struct type
*type
, int regnum
,
366 struct frame_info
*frame
);
368 extern CORE_ADDR
address_from_register (struct type
*type
, int regnum
,
369 struct frame_info
*frame
);
371 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
373 extern struct value
*address_of_variable (struct symbol
*var
, struct block
*b
);
375 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
377 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
379 extern int symbol_read_needs_frame (struct symbol
*);
381 extern struct value
*read_var_value (struct symbol
*var
,
382 struct frame_info
*frame
);
384 extern struct value
*allocate_value (struct type
*type
);
385 extern struct value
*allocate_value_lazy (struct type
*type
);
386 extern void allocate_value_contents (struct value
*value
);
388 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
390 extern struct value
*value_mark (void);
392 extern void value_free_to_mark (struct value
*mark
);
394 extern struct value
*value_typed_string (char *ptr
, int len
,
395 struct type
*char_type
);
396 extern struct value
*value_string (char *ptr
, int len
);
397 extern struct value
*value_bitstring (char *ptr
, int len
);
399 extern struct value
*value_array (int lowbound
, int highbound
,
400 struct value
**elemvec
);
402 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
404 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
407 extern struct value
*value_ptradd (struct value
*arg1
, struct value
*arg2
);
409 extern struct value
*value_ptrsub (struct value
*arg1
, struct value
*arg2
);
411 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
413 extern int value_must_coerce_to_target (struct value
*arg1
);
415 extern struct value
*value_coerce_to_target (struct value
*arg1
);
417 extern struct value
*value_coerce_array (struct value
*arg1
);
419 extern struct value
*value_coerce_function (struct value
*arg1
);
421 extern struct value
*value_ind (struct value
*arg1
);
423 extern struct value
*value_addr (struct value
*arg1
);
425 extern struct value
*value_ref (struct value
*arg1
);
427 extern struct value
*value_assign (struct value
*toval
,
428 struct value
*fromval
);
430 extern struct value
*value_pos (struct value
*arg1
);
432 extern struct value
*value_neg (struct value
*arg1
);
434 extern struct value
*value_complement (struct value
*arg1
);
436 extern struct value
*value_struct_elt (struct value
**argp
,
438 char *name
, int *static_memfuncp
,
441 extern struct value
*value_aggregate_elt (struct type
*curtype
,
446 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
448 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
450 struct type
**, int *);
452 extern int find_overload_match (struct type
**arg_types
, int nargs
,
453 char *name
, int method
, int lax
,
454 struct value
**objp
, struct symbol
*fsym
,
455 struct value
**valp
, struct symbol
**symp
,
458 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
460 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
462 struct type
*arg_type
);
465 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
468 extern struct value
*value_full_object (struct value
*, struct type
*, int,
471 extern struct value
*value_cast_pointers (struct type
*, struct value
*);
473 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
475 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
477 extern struct value
*value_one (struct type
*type
, enum lval_type lv
);
479 extern struct value
*value_repeat (struct value
*arg1
, int count
);
481 extern struct value
*value_subscript (struct value
*array
, struct value
*idx
);
483 extern struct value
*value_bitstring_subscript (struct type
*type
,
484 struct value
*bitstring
,
487 extern struct value
*register_value_being_returned (struct type
*valtype
,
488 struct regcache
*retbuf
);
490 extern int value_in (struct value
*element
, struct value
*set
);
492 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
495 extern int using_struct_return (struct type
*func_type
,
496 struct type
*value_type
);
498 extern struct value
*evaluate_expression (struct expression
*exp
);
500 extern struct value
*evaluate_type (struct expression
*exp
);
502 extern struct value
*evaluate_subexpression_type (struct expression
*exp
,
505 extern char *extract_field_op (struct expression
*exp
, int *subexp
);
507 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
510 extern struct value
*parse_and_eval (char *exp
);
512 extern struct value
*parse_to_comma_and_eval (char **expp
);
514 extern struct type
*parse_and_eval_type (char *p
, int length
);
516 extern CORE_ADDR
parse_and_eval_address (char *exp
);
518 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
520 extern LONGEST
parse_and_eval_long (char *exp
);
522 extern void unop_promote (const struct language_defn
*language
,
523 struct gdbarch
*gdbarch
,
524 struct value
**arg1
);
526 extern void binop_promote (const struct language_defn
*language
,
527 struct gdbarch
*gdbarch
,
528 struct value
**arg1
, struct value
**arg2
);
530 extern struct value
*access_value_history (int num
);
532 extern struct value
*value_of_internalvar (struct internalvar
*var
);
534 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
536 extern void set_internalvar_component (struct internalvar
*var
,
538 int bitpos
, int bitsize
,
539 struct value
*newvalue
);
541 extern struct internalvar
*lookup_only_internalvar (const char *name
);
543 extern struct internalvar
*create_internalvar (const char *name
);
545 extern struct internalvar
*
546 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
);
548 extern struct internalvar
*lookup_internalvar (const char *name
);
550 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
552 extern int value_less (struct value
*arg1
, struct value
*arg2
);
554 extern int value_logical_not (struct value
*arg1
);
558 extern struct value
*value_of_this (int complain
);
560 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
562 enum exp_opcode otherop
,
565 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
568 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
569 int j
, struct type
*type
, int offset
);
571 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
574 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
576 extern int destructor_name_p (const char *name
, const struct type
*type
);
578 extern void value_free (struct value
*val
);
580 extern void free_all_values (void);
582 extern void release_value (struct value
*val
);
584 extern int record_latest_value (struct value
*val
);
586 extern void modify_field (gdb_byte
*addr
, LONGEST fieldval
, int bitpos
,
589 extern void type_print (struct type
*type
, char *varstring
,
590 struct ui_file
*stream
, int show
);
592 extern char *type_to_string (struct type
*type
);
594 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
596 struct value
**valuep
, int *errp
);
598 extern void print_longest (struct ui_file
*stream
, int format
,
599 int use_local
, LONGEST val
);
601 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
602 struct ui_file
*stream
);
604 extern void print_decimal_floating (const gdb_byte
*valaddr
, struct type
*type
,
605 struct ui_file
*stream
);
607 extern int value_print (struct value
*val
, struct ui_file
*stream
,
608 const struct value_print_options
*options
);
610 extern void value_print_array_elements (struct value
*val
,
611 struct ui_file
*stream
, int format
,
612 enum val_prettyprint pretty
);
614 extern struct value
*value_release_to_mark (struct value
*mark
);
616 extern int val_print (struct type
*type
, const gdb_byte
*valaddr
,
617 int embedded_offset
, CORE_ADDR address
,
618 struct ui_file
*stream
, int recurse
,
619 const struct value_print_options
*options
,
620 const struct language_defn
*language
);
622 extern int common_val_print (struct value
*val
,
623 struct ui_file
*stream
, int recurse
,
624 const struct value_print_options
*options
,
625 const struct language_defn
*language
);
627 extern int val_print_string (struct type
*elttype
, CORE_ADDR addr
, int len
,
628 struct ui_file
*stream
,
629 const struct value_print_options
*options
);
631 extern void print_variable_and_value (const char *name
,
633 struct frame_info
*frame
,
634 struct ui_file
*stream
,
637 extern int check_field (struct type
*, const char *);
639 extern void typedef_print (struct type
*type
, struct symbol
*news
,
640 struct ui_file
*stream
);
642 extern char *internalvar_name (struct internalvar
*var
);
644 extern void preserve_values (struct objfile
*);
648 extern struct value
*value_copy (struct value
*);
652 extern struct value
*varying_to_slice (struct value
*);
654 extern struct value
*value_slice (struct value
*, int, int);
656 extern struct value
*value_literal_complex (struct value
*, struct value
*,
659 extern struct value
*find_function_in_inferior (const char *,
662 extern struct value
*value_allocate_space_in_inferior (int);
664 extern struct value
*value_of_local (const char *name
, int complain
);
666 extern struct value
* value_subscripted_rvalue (struct value
*array
, struct value
*idx
, int lowerbound
);
668 /* User function handler. */
670 typedef struct value
*(*internal_function_fn
) (void *cookie
,
672 struct value
**argv
);
674 void add_internal_function (const char *name
, const char *doc
,
675 internal_function_fn handler
,
678 struct value
*call_internal_function (struct value
*function
,
679 int argc
, struct value
**argv
);
681 char *value_internal_function_name (struct value
*);
683 #endif /* !defined (VALUE_H) */