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 /* Only used for bitfields; the containing value. This allows a
80 single read from the target when displaying multiple
83 struct value
*value_parent (struct value
*);
85 /* Describes offset of a value within lval of a structure in bytes.
86 If lval == lval_memory, this is an offset to the address. If lval
87 == lval_register, this is a further offset from location.address
88 within the registers structure. Note also the member
89 embedded_offset below. */
91 extern int value_offset (struct value
*);
92 extern void set_value_offset (struct value
*, int offset
);
94 /* The comment from "struct value" reads: ``Is it modifiable? Only
95 relevant if lval != not_lval.''. Shouldn't the value instead be
96 not_lval and be done with it? */
98 extern int deprecated_value_modifiable (struct value
*value
);
99 extern void deprecated_set_value_modifiable (struct value
*value
,
102 /* If a value represents a C++ object, then the `type' field gives the
103 object's compile-time type. If the object actually belongs to some
104 class derived from `type', perhaps with other base classes and
105 additional members, then `type' is just a subobject of the real
106 thing, and the full object is probably larger than `type' would
109 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
110 actually determine the object's run-time type by looking at the
111 run-time type information in the vtable. When this information is
112 available, we may elect to read in the entire object, for several
115 - When printing the value, the user would probably rather see the
116 full object, not just the limited portion apparent from the
119 - If `type' has virtual base classes, then even printing `type'
120 alone may require reaching outside the `type' portion of the
121 object to wherever the virtual base class has been stored.
123 When we store the entire object, `enclosing_type' is the run-time
124 type -- the complete object -- and `embedded_offset' is the offset
125 of `type' within that larger type, in bytes. The value_contents()
126 macro takes `embedded_offset' into account, so most GDB code
127 continues to see the `type' portion of the value, just as the
130 If `type' is a pointer to an object, then `enclosing_type' is a
131 pointer to the object's run-time type, and `pointed_to_offset' is
132 the offset in bytes from the full object to the pointed-to object
133 -- that is, the value `embedded_offset' would have if we followed
134 the pointer and fetched the complete object. (I don't really see
135 the point. Why not just determine the run-time type when you
136 indirect, and avoid the special case? The contents don't matter
137 until you indirect anyway.)
139 If we're not doing anything fancy, `enclosing_type' is equal to
140 `type', and `embedded_offset' is zero, so everything works
143 extern struct type
*value_enclosing_type (struct value
*);
144 extern struct value
*value_change_enclosing_type (struct value
*val
,
145 struct type
*new_type
);
146 extern int value_pointed_to_offset (struct value
*value
);
147 extern void set_value_pointed_to_offset (struct value
*value
, int val
);
148 extern int value_embedded_offset (struct value
*value
);
149 extern void set_value_embedded_offset (struct value
*value
, int val
);
151 /* For lval_computed values, this structure holds functions used to
152 retrieve and set the value (or portions of the value).
154 For each function, 'V' is the 'this' pointer: an lval_funcs
155 function F may always assume that the V it receives is an
156 lval_computed value, and has F in the appropriate slot of its
157 lval_funcs structure. */
161 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
162 a problem arises in obtaining VALUE's bits, this function should
164 void (*read
) (struct value
*v
);
166 /* Handle an assignment TOVAL = FROMVAL by writing the value of
167 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
168 been updated. If a problem arises in doing so, this function
169 should call 'error'. */
170 void (*write
) (struct value
*toval
, struct value
*fromval
);
172 /* Return a duplicate of VALUE's closure, for use in a new value.
173 This may simply return the same closure, if VALUE's is
174 reference-counted or statically allocated.
176 This may be NULL, in which case VALUE's closure is re-used in the
178 void *(*copy_closure
) (struct value
*v
);
180 /* Drop VALUE's reference to its closure. Maybe this frees the
181 closure; maybe this decrements a reference count; maybe the
182 closure is statically allocated and this does nothing.
184 This may be NULL, in which case no action is taken to free
186 void (*free_closure
) (struct value
*v
);
189 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
190 and closure CLOSURE. */
192 extern struct value
*allocate_computed_value (struct type
*type
,
193 struct lval_funcs
*funcs
,
196 /* If VALUE is lval_computed, return its lval_funcs structure. */
198 extern struct lval_funcs
*value_computed_funcs (struct value
*value
);
200 /* If VALUE is lval_computed, return its closure. The meaning of the
201 returned value depends on the functions VALUE uses. */
203 extern void *value_computed_closure (struct value
*value
);
205 /* If zero, contents of this value are in the contents field. If
206 nonzero, contents are in inferior. If the lval field is lval_memory,
207 the contents are in inferior memory at location.address plus offset.
208 The lval field may also be lval_register.
210 WARNING: This field is used by the code which handles watchpoints
211 (see breakpoint.c) to decide whether a particular value can be
212 watched by hardware watchpoints. If the lazy flag is set for some
213 member of a value chain, it is assumed that this member of the
214 chain doesn't need to be watched as part of watching the value
215 itself. This is how GDB avoids watching the entire struct or array
216 when the user wants to watch a single struct member or array
217 element. If you ever change the way lazy flag is set and reset, be
218 sure to consider this use as well! */
220 extern int value_lazy (struct value
*);
221 extern void set_value_lazy (struct value
*value
, int val
);
223 /* value_contents() and value_contents_raw() both return the address
224 of the gdb buffer used to hold a copy of the contents of the lval.
225 value_contents() is used when the contents of the buffer are needed
226 -- it uses value_fetch_lazy() to load the buffer from the process
227 being debugged if it hasn't already been loaded
228 (value_contents_writeable() is used when a writeable but fetched
229 buffer is required).. value_contents_raw() is used when data is
230 being stored into the buffer, or when it is certain that the
231 contents of the buffer are valid.
233 Note: The contents pointer is adjusted by the offset required to
234 get to the real subobject, if the value happens to represent
235 something embedded in a larger run-time object. */
237 extern gdb_byte
*value_contents_raw (struct value
*);
239 /* Actual contents of the value. For use of this value; setting it
240 uses the stuff above. Not valid if lazy is nonzero. Target
241 byte-order. We force it to be aligned properly for any possible
242 value. Note that a value therefore extends beyond what is
245 extern const gdb_byte
*value_contents (struct value
*);
246 extern gdb_byte
*value_contents_writeable (struct value
*);
248 /* The ALL variants of the above two macros do not adjust the returned
249 pointer by the embedded_offset value. */
251 extern gdb_byte
*value_contents_all_raw (struct value
*);
252 extern const gdb_byte
*value_contents_all (struct value
*);
254 extern int value_fetch_lazy (struct value
*val
);
255 extern int value_contents_equal (struct value
*val1
, struct value
*val2
);
257 /* If nonzero, this is the value of a variable which does not actually
258 exist in the program. */
259 extern int value_optimized_out (struct value
*value
);
260 extern void set_value_optimized_out (struct value
*value
, int val
);
262 /* Set or return field indicating whether a variable is initialized or
263 not, based on debugging information supplied by the compiler.
264 1 = initialized; 0 = uninitialized. */
265 extern int value_initialized (struct value
*);
266 extern void set_value_initialized (struct value
*, int);
268 /* Set COMPONENT's location as appropriate for a component of WHOLE
269 --- regardless of what kind of lvalue WHOLE is. */
270 extern void set_value_component_location (struct value
*component
,
271 struct value
*whole
);
273 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
274 single value might have multiple LVALs), this hacked interface is
275 limited to just the first PIECE. Expect further change. */
276 /* Type of value; either not an lval, or one of the various different
277 possible kinds of lval. */
278 extern enum lval_type
*deprecated_value_lval_hack (struct value
*);
279 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
281 /* If lval == lval_memory, return the address in the inferior. If
282 lval == lval_register, return the byte offset into the registers
283 structure. Otherwise, return 0. The returned address
284 includes the offset, if any. */
285 extern CORE_ADDR
value_address (struct value
*);
287 /* Like value_address, except the result does not include value's
289 extern CORE_ADDR
value_raw_address (struct value
*);
291 /* Set the address of a value. */
292 extern void set_value_address (struct value
*, CORE_ADDR
);
294 /* Pointer to internal variable. */
295 extern struct internalvar
**deprecated_value_internalvar_hack (struct value
*);
296 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
298 /* Frame register value is relative to. This will be described in the
299 lval enum above as "lval_register". */
300 extern struct frame_id
*deprecated_value_frame_id_hack (struct value
*);
301 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
303 /* Register number if the value is from a register. */
304 extern short *deprecated_value_regnum_hack (struct value
*);
305 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
307 /* Convert a REF to the object referenced. */
309 extern struct value
*coerce_ref (struct value
*value
);
311 /* If ARG is an array, convert it to a pointer.
312 If ARG is a function, convert it to a function pointer.
314 References are dereferenced. */
316 extern struct value
*coerce_array (struct value
*value
);
321 #include "gdbtypes.h"
322 #include "expression.h"
327 extern void print_address_demangle (struct gdbarch
*, CORE_ADDR
,
328 struct ui_file
*, int);
330 extern LONGEST
value_as_long (struct value
*val
);
331 extern DOUBLEST
value_as_double (struct value
*val
);
332 extern CORE_ADDR
value_as_address (struct value
*val
);
334 extern LONGEST
unpack_long (struct type
*type
, const gdb_byte
*valaddr
);
335 extern DOUBLEST
unpack_double (struct type
*type
, const gdb_byte
*valaddr
,
337 extern CORE_ADDR
unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
);
338 LONGEST
unpack_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
339 int bitpos
, int bitsize
);
340 extern LONGEST
unpack_field_as_long (struct type
*type
,
341 const gdb_byte
*valaddr
,
344 extern void pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
);
346 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
347 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
348 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
349 extern struct value
*value_from_decfloat (struct type
*type
,
350 const gdb_byte
*decbytes
);
352 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
353 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
355 extern struct value
*value_from_contents_and_address (struct type
*,
359 extern struct value
*default_value_from_register (struct type
*type
,
361 struct frame_info
*frame
);
363 extern struct value
*value_from_register (struct type
*type
, int regnum
,
364 struct frame_info
*frame
);
366 extern CORE_ADDR
address_from_register (struct type
*type
, int regnum
,
367 struct frame_info
*frame
);
369 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
371 extern struct value
*address_of_variable (struct symbol
*var
, struct block
*b
);
373 extern struct value
*value_of_register (int regnum
, struct frame_info
*frame
);
375 struct value
*value_of_register_lazy (struct frame_info
*frame
, int regnum
);
377 extern int symbol_read_needs_frame (struct symbol
*);
379 extern struct value
*read_var_value (struct symbol
*var
,
380 struct frame_info
*frame
);
382 extern struct value
*allocate_value (struct type
*type
);
383 extern struct value
*allocate_value_lazy (struct type
*type
);
384 extern void allocate_value_contents (struct value
*value
);
386 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
388 extern struct value
*value_mark (void);
390 extern void value_free_to_mark (struct value
*mark
);
392 extern struct value
*value_cstring (char *ptr
, int len
,
393 struct type
*char_type
);
394 extern struct value
*value_string (char *ptr
, int len
,
395 struct type
*char_type
);
396 extern struct value
*value_bitstring (char *ptr
, int len
,
397 struct type
*index_type
);
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
, LONGEST arg2
);
409 extern LONGEST
value_ptrdiff (struct value
*arg1
, struct value
*arg2
);
411 extern int value_must_coerce_to_target (struct value
*arg1
);
413 extern struct value
*value_coerce_to_target (struct value
*arg1
);
415 extern struct value
*value_coerce_array (struct value
*arg1
);
417 extern struct value
*value_coerce_function (struct value
*arg1
);
419 extern struct value
*value_ind (struct value
*arg1
);
421 extern struct value
*value_addr (struct value
*arg1
);
423 extern struct value
*value_ref (struct value
*arg1
);
425 extern struct value
*value_assign (struct value
*toval
,
426 struct value
*fromval
);
428 extern struct value
*value_pos (struct value
*arg1
);
430 extern struct value
*value_neg (struct value
*arg1
);
432 extern struct value
*value_complement (struct value
*arg1
);
434 extern struct value
*value_struct_elt (struct value
**argp
,
436 char *name
, int *static_memfuncp
,
439 extern struct value
*value_aggregate_elt (struct type
*curtype
,
444 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
446 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
448 struct type
**, int *);
450 extern int find_overload_match (struct type
**arg_types
, int nargs
,
451 char *name
, int method
, int lax
,
452 struct value
**objp
, struct symbol
*fsym
,
453 struct value
**valp
, struct symbol
**symp
,
456 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
458 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
460 struct type
*arg_type
);
463 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
466 extern struct value
*value_full_object (struct value
*, struct type
*, int,
469 extern struct value
*value_cast_pointers (struct type
*, struct value
*);
471 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
473 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
475 extern struct value
*value_one (struct type
*type
, enum lval_type lv
);
477 extern struct value
*value_repeat (struct value
*arg1
, int count
);
479 extern struct value
*value_subscript (struct value
*array
, LONGEST index
);
481 extern struct value
*value_bitstring_subscript (struct type
*type
,
482 struct value
*bitstring
,
485 extern struct value
*register_value_being_returned (struct type
*valtype
,
486 struct regcache
*retbuf
);
488 extern int value_in (struct value
*element
, struct value
*set
);
490 extern int value_bit_index (struct type
*type
, const gdb_byte
*addr
,
493 extern int using_struct_return (struct gdbarch
*gdbarch
,
494 struct type
*func_type
,
495 struct type
*value_type
);
497 extern struct value
*evaluate_expression (struct expression
*exp
);
499 extern struct value
*evaluate_type (struct expression
*exp
);
501 extern struct value
*evaluate_subexp (struct type
*expect_type
,
502 struct expression
*exp
,
503 int *pos
, enum noside noside
);
505 extern struct value
*evaluate_subexpression_type (struct expression
*exp
,
508 extern char *extract_field_op (struct expression
*exp
, int *subexp
);
510 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
513 extern struct value
*parse_and_eval (char *exp
);
515 extern struct value
*parse_to_comma_and_eval (char **expp
);
517 extern struct type
*parse_and_eval_type (char *p
, int length
);
519 extern CORE_ADDR
parse_and_eval_address (char *exp
);
521 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
523 extern LONGEST
parse_and_eval_long (char *exp
);
525 extern void unop_promote (const struct language_defn
*language
,
526 struct gdbarch
*gdbarch
,
527 struct value
**arg1
);
529 extern void binop_promote (const struct language_defn
*language
,
530 struct gdbarch
*gdbarch
,
531 struct value
**arg1
, struct value
**arg2
);
533 extern struct value
*access_value_history (int num
);
535 extern struct value
*value_of_internalvar (struct gdbarch
*gdbarch
,
536 struct internalvar
*var
);
538 extern int get_internalvar_integer (struct internalvar
*var
, LONGEST
*l
);
540 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
542 extern void set_internalvar_integer (struct internalvar
*var
, LONGEST l
);
544 extern void set_internalvar_string (struct internalvar
*var
,
547 extern void clear_internalvar (struct internalvar
*var
);
549 extern void set_internalvar_component (struct internalvar
*var
,
551 int bitpos
, int bitsize
,
552 struct value
*newvalue
);
554 extern struct internalvar
*lookup_only_internalvar (const char *name
);
556 extern struct internalvar
*create_internalvar (const char *name
);
558 typedef struct value
* (*internalvar_make_value
) (struct gdbarch
*,
559 struct internalvar
*);
560 extern struct internalvar
*
561 create_internalvar_type_lazy (char *name
, internalvar_make_value fun
);
563 extern struct internalvar
*lookup_internalvar (const char *name
);
565 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
567 extern int value_less (struct value
*arg1
, struct value
*arg2
);
569 extern int value_logical_not (struct value
*arg1
);
573 extern struct value
*value_of_this (int complain
);
575 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
577 enum exp_opcode otherop
,
580 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
583 extern struct value
*value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
584 int j
, struct type
*type
, int offset
);
586 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
589 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
591 extern int destructor_name_p (const char *name
, const struct type
*type
);
593 extern void value_incref (struct value
*val
);
595 extern void value_free (struct value
*val
);
597 extern void free_all_values (void);
599 extern void release_value (struct value
*val
);
601 extern int record_latest_value (struct value
*val
);
603 extern void modify_field (struct type
*type
, gdb_byte
*addr
,
604 LONGEST fieldval
, int bitpos
, int bitsize
);
606 extern void type_print (struct type
*type
, char *varstring
,
607 struct ui_file
*stream
, int show
);
609 extern char *type_to_string (struct type
*type
);
611 extern gdb_byte
*baseclass_addr (struct type
*type
, int index
,
613 struct value
**valuep
, int *errp
);
615 extern void print_longest (struct ui_file
*stream
, int format
,
616 int use_local
, LONGEST val
);
618 extern void print_floating (const gdb_byte
*valaddr
, struct type
*type
,
619 struct ui_file
*stream
);
621 extern void print_decimal_floating (const gdb_byte
*valaddr
, struct type
*type
,
622 struct ui_file
*stream
);
624 extern int value_print (struct value
*val
, struct ui_file
*stream
,
625 const struct value_print_options
*options
);
627 extern void value_print_array_elements (struct value
*val
,
628 struct ui_file
*stream
, int format
,
629 enum val_prettyprint pretty
);
631 extern struct value
*value_release_to_mark (struct value
*mark
);
633 extern int val_print (struct type
*type
, const gdb_byte
*valaddr
,
634 int embedded_offset
, CORE_ADDR address
,
635 struct ui_file
*stream
, int recurse
,
636 const struct value_print_options
*options
,
637 const struct language_defn
*language
);
639 extern int common_val_print (struct value
*val
,
640 struct ui_file
*stream
, int recurse
,
641 const struct value_print_options
*options
,
642 const struct language_defn
*language
);
644 extern int val_print_string (struct type
*elttype
, CORE_ADDR addr
, int len
,
645 struct ui_file
*stream
,
646 const struct value_print_options
*options
);
648 extern void print_variable_and_value (const char *name
,
650 struct frame_info
*frame
,
651 struct ui_file
*stream
,
654 extern int check_field (struct type
*, const char *);
656 extern void typedef_print (struct type
*type
, struct symbol
*news
,
657 struct ui_file
*stream
);
659 extern char *internalvar_name (struct internalvar
*var
);
661 extern void preserve_values (struct objfile
*);
665 extern struct value
*value_copy (struct value
*);
669 extern struct value
*varying_to_slice (struct value
*);
671 extern struct value
*value_slice (struct value
*, int, int);
673 extern struct value
*value_literal_complex (struct value
*, struct value
*,
676 extern struct value
*find_function_in_inferior (const char *,
679 extern struct value
*value_allocate_space_in_inferior (int);
681 extern struct value
*value_of_local (const char *name
, int complain
);
683 extern struct value
*value_subscripted_rvalue (struct value
*array
,
684 LONGEST index
, int lowerbound
);
686 /* User function handler. */
688 typedef struct value
*(*internal_function_fn
) (struct gdbarch
*gdbarch
,
689 const struct language_defn
*language
,
692 struct value
**argv
);
694 void add_internal_function (const char *name
, const char *doc
,
695 internal_function_fn handler
,
698 struct value
*call_internal_function (struct gdbarch
*gdbarch
,
699 const struct language_defn
*language
,
700 struct value
*function
,
701 int argc
, struct value
**argv
);
703 char *value_internal_function_name (struct value
*);
705 #endif /* !defined (VALUE_H) */