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, return the address in the inferior. If
276 lval == lval_register, return the byte offset into the registers
277 structure. Otherwise, return 0. The returned address
278 includes the offset, if any. */
279 extern CORE_ADDR
value_address (struct value
*);
281 /* Like value_address, except the result does not include value's
283 extern CORE_ADDR
value_raw_address (struct value
*);
285 /* Set the address of a value. */
286 extern void set_value_address (struct value
*, CORE_ADDR
);
288 /* Pointer to internal variable. */
289 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
290 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
292 /* Frame register value is relative to. This will be described in the
293 lval enum above as "lval_register". */
294 extern struct frame_id
*deprecated_value_frame_id_hack (struct value
*);
295 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
297 /* Register number if the value is from a register. */
298 extern short *deprecated_value_regnum_hack (struct value
*);
299 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
301 /* Convert a REF to the object referenced. */
303 extern struct value
*coerce_ref (struct value
*value
);
305 /* If ARG is an array, convert it to a pointer.
306 If ARG is a function, convert it to a function pointer.
308 References are dereferenced. */
310 extern struct value
*coerce_array (struct value
*value
);
315 #include "gdbtypes.h"
316 #include "expression.h"
321 extern void print_address_demangle (CORE_ADDR
, struct ui_file
*, int);
323 extern LONGEST
value_as_long (struct value
*val
);
324 extern DOUBLEST
value_as_double (struct value
*val
);
325 extern CORE_ADDR
value_as_address (struct value
*val
);
327 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
328 extern DOUBLEST
unpack_double (struct type
*type
, const gdb_byte
*valaddr
,
330 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
331 extern LONGEST
unpack_field_as_long (struct type
*type
,
332 const gdb_byte
*valaddr
,
335 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
337 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
338 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
339 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
340 extern struct value
*value_from_decfloat (struct type
*type
,
341 const gdb_byte
*decbytes
);
342 extern struct value
*value_from_string (char *string
);
344 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
345 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
347 extern struct value
*value_from_contents_and_address (struct type
*,
351 extern struct value
*default_value_from_register (struct type
*type
,
353 struct frame_info
*frame
);
355 extern struct value
*value_from_register (struct type
*type
, int regnum
,
356 struct frame_info
*frame
);
358 extern CORE_ADDR
address_from_register (struct type
*type
, int regnum
,
359 struct frame_info
*frame
);
361 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
363 extern struct value
*address_of_variable (struct symbol
*var
, struct block
*b
);
365 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
367 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
369 extern int symbol_read_needs_frame (struct symbol
*);
371 extern struct value
*read_var_value (struct symbol
*var
,
372 struct frame_info
*frame
);
374 extern struct value
*allocate_value (struct type
*type
);
375 extern struct value
*allocate_value_lazy (struct type
*type
);
376 extern void allocate_value_contents (struct value
*value
);
378 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
380 extern struct value
*value_mark (void);
382 extern void value_free_to_mark (struct value
*mark
);
384 extern struct value
*value_typed_string (char *ptr
, int len
,
385 struct type
*char_type
);
386 extern struct value
*value_string (char *ptr
, int len
);
387 extern struct value
*value_bitstring (char *ptr
, int len
);
389 extern struct value
*value_array (int lowbound
, int highbound
,
390 struct value
**elemvec
);
392 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
394 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
397 extern struct value
*value_ptradd (struct value
*arg1
, struct value
*arg2
);
399 extern struct value
*value_ptrsub (struct value
*arg1
, struct value
*arg2
);
401 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
403 extern int value_must_coerce_to_target (struct value
*arg1
);
405 extern struct value
*value_coerce_to_target (struct value
*arg1
);
407 extern struct value
*value_coerce_array (struct value
*arg1
);
409 extern struct value
*value_coerce_function (struct value
*arg1
);
411 extern struct value
*value_ind (struct value
*arg1
);
413 extern struct value
*value_addr (struct value
*arg1
);
415 extern struct value
*value_ref (struct value
*arg1
);
417 extern struct value
*value_assign (struct value
*toval
,
418 struct value
*fromval
);
420 extern struct value
*value_pos (struct value
*arg1
);
422 extern struct value
*value_neg (struct value
*arg1
);
424 extern struct value
*value_complement (struct value
*arg1
);
426 extern struct value
*value_struct_elt (struct value
**argp
,
428 char *name
, int *static_memfuncp
,
431 extern struct value
*value_aggregate_elt (struct type
*curtype
,
436 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
438 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
440 struct type
**, int *);
442 extern int find_overload_match (struct type
**arg_types
, int nargs
,
443 char *name
, int method
, int lax
,
444 struct value
**objp
, struct symbol
*fsym
,
445 struct value
**valp
, struct symbol
**symp
,
448 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
450 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
452 struct type
*arg_type
);
455 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
458 extern struct value
*value_full_object (struct value
*, struct type
*, int,
461 extern struct value
*value_cast_pointers (struct type
*, struct value
*);
463 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
465 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
467 extern struct value
*value_one (struct type
*type
, enum lval_type lv
);
469 extern struct value
*value_repeat (struct value
*arg1
, int count
);
471 extern struct value
*value_subscript (struct value
*array
, struct value
*idx
);
473 extern struct value
*value_bitstring_subscript (struct type
*type
,
474 struct value
*bitstring
,
477 extern struct value
*register_value_being_returned (struct type
*valtype
,
478 struct regcache
*retbuf
);
480 extern int value_in (struct value
*element
, struct value
*set
);
482 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
485 extern int using_struct_return (struct gdbarch
*gdbarch
,
486 struct type
*func_type
,
487 struct type
*value_type
);
489 extern struct value
*evaluate_expression (struct expression
*exp
);
491 extern struct value
*evaluate_type (struct expression
*exp
);
493 extern struct value
*evaluate_subexpression_type (struct expression
*exp
,
496 extern char *extract_field_op (struct expression
*exp
, int *subexp
);
498 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
501 extern struct value
*parse_and_eval (char *exp
);
503 extern struct value
*parse_to_comma_and_eval (char **expp
);
505 extern struct type
*parse_and_eval_type (char *p
, int length
);
507 extern CORE_ADDR
parse_and_eval_address (char *exp
);
509 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
511 extern LONGEST
parse_and_eval_long (char *exp
);
513 extern void unop_promote (const struct language_defn
*language
,
514 struct gdbarch
*gdbarch
,
515 struct value
**arg1
);
517 extern void binop_promote (const struct language_defn
*language
,
518 struct gdbarch
*gdbarch
,
519 struct value
**arg1
, struct value
**arg2
);
521 extern struct value
*access_value_history (int num
);
523 extern struct value
*value_of_internalvar (struct internalvar
*var
);
525 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
527 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
529 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
531 extern void clear_internalvar (struct internalvar
*var
);
533 extern void set_internalvar_component (struct internalvar
*var
,
535 int bitpos
, int bitsize
,
536 struct value
*newvalue
);
538 extern struct internalvar
*lookup_only_internalvar (const char *name
);
540 extern struct internalvar
*create_internalvar (const char *name
);
542 typedef struct value
* (*internalvar_make_value
) (struct internalvar
*);
544 extern struct internalvar
*
545 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
);
547 extern struct internalvar
*lookup_internalvar (const char *name
);
549 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
551 extern int value_less (struct value
*arg1
, struct value
*arg2
);
553 extern int value_logical_not (struct value
*arg1
);
557 extern struct value
*value_of_this (int complain
);
559 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
561 enum exp_opcode otherop
,
564 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
567 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
568 int j
, struct type
*type
, int offset
);
570 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
573 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
575 extern int destructor_name_p (const char *name
, const struct type
*type
);
577 extern void value_free (struct value
*val
);
579 extern void free_all_values (void);
581 extern void release_value (struct value
*val
);
583 extern int record_latest_value (struct value
*val
);
585 extern void modify_field (gdb_byte
*addr
, LONGEST fieldval
, int bitpos
,
588 extern void type_print (struct type
*type
, char *varstring
,
589 struct ui_file
*stream
, int show
);
591 extern char *type_to_string (struct type
*type
);
593 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
595 struct value
**valuep
, int *errp
);
597 extern void print_longest (struct ui_file
*stream
, int format
,
598 int use_local
, LONGEST val
);
600 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
601 struct ui_file
*stream
);
603 extern void print_decimal_floating (const gdb_byte
*valaddr
, struct type
*type
,
604 struct ui_file
*stream
);
606 extern int value_print (struct value
*val
, struct ui_file
*stream
,
607 const struct value_print_options
*options
);
609 extern void value_print_array_elements (struct value
*val
,
610 struct ui_file
*stream
, int format
,
611 enum val_prettyprint pretty
);
613 extern struct value
*value_release_to_mark (struct value
*mark
);
615 extern int val_print (struct type
*type
, const gdb_byte
*valaddr
,
616 int embedded_offset
, CORE_ADDR address
,
617 struct ui_file
*stream
, int recurse
,
618 const struct value_print_options
*options
,
619 const struct language_defn
*language
);
621 extern int common_val_print (struct value
*val
,
622 struct ui_file
*stream
, int recurse
,
623 const struct value_print_options
*options
,
624 const struct language_defn
*language
);
626 extern int val_print_string (struct type
*elttype
, CORE_ADDR addr
, int len
,
627 struct ui_file
*stream
,
628 const struct value_print_options
*options
);
630 extern void print_variable_and_value (const char *name
,
632 struct frame_info
*frame
,
633 struct ui_file
*stream
,
636 extern int check_field (struct type
*, const char *);
638 extern void typedef_print (struct type
*type
, struct symbol
*news
,
639 struct ui_file
*stream
);
641 extern char *internalvar_name (struct internalvar
*var
);
643 extern void preserve_values (struct objfile
*);
647 extern struct value
*value_copy (struct value
*);
651 extern struct value
*varying_to_slice (struct value
*);
653 extern struct value
*value_slice (struct value
*, int, int);
655 extern struct value
*value_literal_complex (struct value
*, struct value
*,
658 extern struct value
*find_function_in_inferior (const char *,
661 extern struct value
*value_allocate_space_in_inferior (int);
663 extern struct value
*value_of_local (const char *name
, int complain
);
665 extern struct value
* value_subscripted_rvalue (struct value
*array
, struct value
*idx
, int lowerbound
);
667 /* User function handler. */
669 typedef struct value
*(*internal_function_fn
) (void *cookie
,
671 struct value
**argv
);
673 void add_internal_function (const char *name
, const char *doc
,
674 internal_function_fn handler
,
677 struct value
*call_internal_function (struct value
*function
,
678 int argc
, struct value
**argv
);
680 char *value_internal_function_name (struct value
*);
682 #endif /* !defined (VALUE_H) */