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, 2010 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 (const 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 (const 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 (const 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 (const 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 /* Check the validity of some bits in VALUE. This should return 1
168 if all the bits starting at OFFSET and extending for LENGTH bits
169 are valid, or 0 if any bit is invalid. */
170 int (*check_validity) (const struct value *value, int offset, int length);
172 /* Return 1 if any bit in VALUE is valid, 0 if they are all invalid. */
173 int (*check_all_valid) (const struct value *value);
175 /* Return a duplicate of VALUE's closure, for use in a new value.
176 This may simply return the same closure, if VALUE's is
177 reference-counted or statically allocated.
179 This may be NULL, in which case VALUE's closure is re-used in the
181 void *(*copy_closure) (const struct value *v);
183 /* Drop VALUE's reference to its closure. Maybe this frees the
184 closure; maybe this decrements a reference count; maybe the
185 closure is statically allocated and this does nothing.
187 This may be NULL, in which case no action is taken to free
189 void (*free_closure) (struct value *v);
192 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
193 and closure CLOSURE. */
195 extern struct value *allocate_computed_value (struct type *type,
196 struct lval_funcs *funcs,
199 /* If VALUE is lval_computed, return its lval_funcs structure. */
201 extern struct lval_funcs *value_computed_funcs (struct value *value);
203 /* If VALUE is lval_computed, return its closure. The meaning of the
204 returned value depends on the functions VALUE uses. */
206 extern void *value_computed_closure (const struct value *value);
208 /* If zero, contents of this value are in the contents field. If
209 nonzero, contents are in inferior. If the lval field is lval_memory,
210 the contents are in inferior memory at location.address plus offset.
211 The lval field may also be lval_register.
213 WARNING: This field is used by the code which handles watchpoints
214 (see breakpoint.c) to decide whether a particular value can be
215 watched by hardware watchpoints. If the lazy flag is set for some
216 member of a value chain, it is assumed that this member of the
217 chain doesn't need to be watched as part of watching the value
218 itself. This is how GDB avoids watching the entire struct or array
219 when the user wants to watch a single struct member or array
220 element. If you ever change the way lazy flag is set and reset, be
221 sure to consider this use as well! */
223 extern int value_lazy (struct value *);
224 extern void set_value_lazy (struct value *value, int val);
226 extern int value_stack (struct value *);
227 extern void set_value_stack (struct value *value, int val);
229 /* value_contents() and value_contents_raw() both return the address
230 of the gdb buffer used to hold a copy of the contents of the lval.
231 value_contents() is used when the contents of the buffer are needed
232 -- it uses value_fetch_lazy() to load the buffer from the process
233 being debugged if it hasn't already been loaded
234 (value_contents_writeable() is used when a writeable but fetched
235 buffer is required).. value_contents_raw() is used when data is
236 being stored into the buffer, or when it is certain that the
237 contents of the buffer are valid.
239 Note: The contents pointer is adjusted by the offset required to
240 get to the real subobject, if the value happens to represent
241 something embedded in a larger run-time object. */
243 extern gdb_byte *value_contents_raw (struct value *);
245 /* Actual contents of the value. For use of this value; setting it
246 uses the stuff above. Not valid if lazy is nonzero. Target
247 byte-order. We force it to be aligned properly for any possible
248 value. Note that a value therefore extends beyond what is
251 extern const gdb_byte *value_contents (struct value *);
252 extern gdb_byte *value_contents_writeable (struct value *);
254 /* The ALL variants of the above two macros do not adjust the returned
255 pointer by the embedded_offset value. */
257 extern gdb_byte *value_contents_all_raw (struct value *);
258 extern const gdb_byte *value_contents_all (struct value *);
260 /* Like value_contents_all, but does not require that the returned
261 bits be valid. This should only be used in situations where you
262 plan to check the validity manually. */
263 extern const gdb_byte *value_contents_for_printing (struct value *value);
265 extern int value_fetch_lazy (struct value *val);
266 extern int value_contents_equal (struct value *val1, struct value *val2);
268 /* If nonzero, this is the value of a variable which does not actually
269 exist in the program. */
270 extern int value_optimized_out (struct value *value);
271 extern void set_value_optimized_out (struct value *value, int val);
273 /* Like value_optimized_out, but return false if any bit in the object
275 extern int value_entirely_optimized_out (const struct value *value);
277 /* Set or return field indicating whether a variable is initialized or
278 not, based on debugging information supplied by the compiler.
279 1 = initialized; 0 = uninitialized. */
280 extern int value_initialized (struct value *);
281 extern void set_value_initialized (struct value *, int);
283 /* Set COMPONENT's location as appropriate for a component of WHOLE
284 --- regardless of what kind of lvalue WHOLE is. */
285 extern void set_value_component_location (struct value *component,
286 const struct value *whole);
288 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
289 single value might have multiple LVALs), this hacked interface is
290 limited to just the first PIECE. Expect further change. */
291 /* Type of value; either not an lval, or one of the various different
292 possible kinds of lval. */
293 extern enum lval_type *deprecated_value_lval_hack (struct value *);
294 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
296 /* If lval == lval_memory, return the address in the inferior. If
297 lval == lval_register, return the byte offset into the registers
298 structure. Otherwise, return 0. The returned address
299 includes the offset, if any. */
300 extern CORE_ADDR value_address (struct value *);
302 /* Like value_address, except the result does not include value's
304 extern CORE_ADDR value_raw_address (struct value *);
306 /* Set the address of a value. */
307 extern void set_value_address (struct value *, CORE_ADDR);
309 /* Pointer to internal variable. */
310 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
311 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
313 /* Frame register value is relative to. This will be described in the
314 lval enum above as "lval_register". */
315 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
316 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
318 /* Register number if the value is from a register. */
319 extern short *deprecated_value_regnum_hack (struct value *);
320 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
322 /* Convert a REF to the object referenced. */
324 extern struct value *coerce_ref (struct value *value);
326 /* If ARG is an array, convert it to a pointer.
327 If ARG is a function, convert it to a function pointer.
329 References are dereferenced. */
331 extern struct value *coerce_array (struct value *value);
333 /* Given a value, determine whether the bits starting at OFFSET and
334 extending for LENGTH bits are valid. This returns nonzero if all
335 bits in the given range are valid, zero if any bit is invalid. */
337 extern int value_bits_valid (const struct value *value,
338 int offset, int length);
343 #include "gdbtypes.h"
344 #include "expression.h"
349 extern void print_address_demangle (struct gdbarch *, CORE_ADDR,
350 struct ui_file *, int);
352 extern LONGEST value_as_long (struct value *val);
353 extern DOUBLEST value_as_double (struct value *val);
354 extern CORE_ADDR value_as_address (struct value *val);
356 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
357 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
359 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
360 LONGEST unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
361 int bitpos, int bitsize);
362 extern LONGEST unpack_field_as_long (struct type *type,
363 const gdb_byte *valaddr,
366 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
368 extern struct value *value_from_longest (struct type *type, LONGEST num);
369 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
370 extern struct value *value_from_double (struct type *type, DOUBLEST num);
371 extern struct value *value_from_decfloat (struct type *type,
372 const gdb_byte *decbytes);
374 extern struct value *value_at (struct type *type, CORE_ADDR addr);
375 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
377 extern struct value *value_from_contents_and_address (struct type *,
381 extern struct value *default_value_from_register (struct type *type,
383 struct frame_info *frame);
385 extern struct value *value_from_register (struct type *type, int regnum,
386 struct frame_info *frame);
388 extern CORE_ADDR address_from_register (struct type *type, int regnum,
389 struct frame_info *frame);
391 extern struct value *value_of_variable (struct symbol *var, struct block *b);
393 extern struct value *address_of_variable (struct symbol *var, struct block *b);
395 extern struct value *value_of_register (int regnum, struct frame_info *frame);
397 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
399 extern int symbol_read_needs_frame (struct symbol *);
401 extern struct value *read_var_value (struct symbol *var,
402 struct frame_info *frame);
404 extern struct value *allocate_value (struct type *type);
405 extern struct value *allocate_value_lazy (struct type *type);
406 extern void allocate_value_contents (struct value *value);
408 extern struct value *allocate_repeat_value (struct type *type, int count);
410 extern struct value *value_mark (void);
412 extern void value_free_to_mark (struct value *mark);
414 extern struct value *value_cstring (char *ptr, int len,
415 struct type *char_type);
416 extern struct value *value_string (char *ptr, int len,
417 struct type *char_type);
418 extern struct value *value_bitstring (char *ptr, int len,
419 struct type *index_type);
421 extern struct value *value_array (int lowbound, int highbound,
422 struct value **elemvec);
424 extern struct value *value_concat (struct value *arg1, struct value *arg2);
426 extern struct value *value_binop (struct value *arg1, struct value *arg2,
429 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
431 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
433 extern int value_must_coerce_to_target (struct value *arg1);
435 extern struct value *value_coerce_to_target (struct value *arg1);
437 extern struct value *value_coerce_array (struct value *arg1);
439 extern struct value *value_coerce_function (struct value *arg1);
441 extern struct value *value_ind (struct value *arg1);
443 extern struct value *value_addr (struct value *arg1);
445 extern struct value *value_ref (struct value *arg1);
447 extern struct value *value_assign (struct value *toval,
448 struct value *fromval);
450 extern struct value *value_pos (struct value *arg1);
452 extern struct value *value_neg (struct value *arg1);
454 extern struct value *value_complement (struct value *arg1);
456 extern struct value *value_struct_elt (struct value **argp,
458 const char *name, int *static_memfuncp,
461 extern struct value *value_aggregate_elt (struct type *curtype,
463 struct type *expect_type,
467 extern struct value *value_static_field (struct type *type, int fieldno);
469 extern struct fn_field *value_find_oload_method_list (struct value **,
472 struct type **, int *);
474 enum oload_search_type { NON_METHOD, METHOD, BOTH };
476 extern int find_overload_match (struct type **arg_types, int nargs,
478 enum oload_search_type method, int lax,
479 struct value **objp, struct symbol *fsym,
480 struct value **valp, struct symbol **symp,
481 int *staticp, const int no_adl);
483 extern struct value *value_field (struct value *arg1, int fieldno);
485 extern struct value *value_primitive_field (struct value *arg1, int offset,
487 struct type *arg_type);
490 extern struct type *value_rtti_target_type (struct value *, int *, int *,
493 extern struct value *value_full_object (struct value *, struct type *, int,
496 extern struct value *value_cast_pointers (struct type *, struct value *);
498 extern struct value *value_cast (struct type *type, struct value *arg2);
500 extern struct value *value_reinterpret_cast (struct type *type,
503 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
505 extern struct value *value_zero (struct type *type, enum lval_type lv);
507 extern struct value *value_one (struct type *type, enum lval_type lv);
509 extern struct value *value_repeat (struct value *arg1, int count);
511 extern struct value *value_subscript (struct value *array, LONGEST index);
513 extern struct value *value_bitstring_subscript (struct type *type,
514 struct value *bitstring,
517 extern struct value *register_value_being_returned (struct type *valtype,
518 struct regcache *retbuf);
520 extern int value_in (struct value *element, struct value *set);
522 extern int value_bit_index (struct type *type, const gdb_byte *addr,
525 extern int using_struct_return (struct gdbarch *gdbarch,
526 struct type *func_type,
527 struct type *value_type);
529 extern struct value *evaluate_expression (struct expression *exp);
531 extern struct value *evaluate_type (struct expression *exp);
533 extern struct value *evaluate_subexp (struct type *expect_type,
534 struct expression *exp,
535 int *pos, enum noside noside);
537 extern struct value *evaluate_subexpression_type (struct expression *exp,
540 extern char *extract_field_op (struct expression *exp, int *subexp);
542 extern struct value *evaluate_subexp_with_coercion (struct expression *,
545 extern struct value *parse_and_eval (char *exp);
547 extern struct value *parse_to_comma_and_eval (char **expp);
549 extern struct type *parse_and_eval_type (char *p, int length);
551 extern CORE_ADDR parse_and_eval_address (char *exp);
553 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
555 extern LONGEST parse_and_eval_long (char *exp);
557 extern void unop_promote (const struct language_defn *language,
558 struct gdbarch *gdbarch,
559 struct value **arg1);
561 extern void binop_promote (const struct language_defn *language,
562 struct gdbarch *gdbarch,
563 struct value **arg1, struct value **arg2);
565 extern struct value *access_value_history (int num);
567 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
568 struct internalvar *var);
570 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
572 extern void set_internalvar (struct internalvar *var, struct value *val);
574 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
576 extern void set_internalvar_string (struct internalvar *var,
579 extern void clear_internalvar (struct internalvar *var);
581 extern void set_internalvar_component (struct internalvar *var,
583 int bitpos, int bitsize,
584 struct value *newvalue);
586 extern struct internalvar *lookup_only_internalvar (const char *name);
588 extern struct internalvar *create_internalvar (const char *name);
590 typedef struct value * (*internalvar_make_value) (struct gdbarch *,
591 struct internalvar *);
592 extern struct internalvar *
593 create_internalvar_type_lazy (char *name, internalvar_make_value fun);
595 extern struct internalvar *lookup_internalvar (const char *name);
597 extern int value_equal (struct value *arg1, struct value *arg2);
599 extern int value_equal_contents (struct value *arg1, struct value *arg2);
601 extern int value_less (struct value *arg1, struct value *arg2);
603 extern int value_logical_not (struct value *arg1);
607 extern struct value *value_of_this (int complain);
609 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
611 enum exp_opcode otherop,
614 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
617 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
618 int j, struct type *type, int offset);
620 extern int binop_types_user_defined_p (enum exp_opcode op,
624 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
627 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
629 extern int destructor_name_p (const char *name, const struct type *type);
631 extern void value_incref (struct value *val);
633 extern void value_free (struct value *val);
635 extern void free_all_values (void);
637 extern void release_value (struct value *val);
639 extern int record_latest_value (struct value *val);
641 extern void modify_field (struct type *type, gdb_byte *addr,
642 LONGEST fieldval, int bitpos, int bitsize);
644 extern void type_print (struct type *type, char *varstring,
645 struct ui_file *stream, int show);
647 extern char *type_to_string (struct type *type);
649 extern gdb_byte *baseclass_addr (struct type *type, int index,
651 struct value **valuep, int *errp);
653 extern void print_longest (struct ui_file *stream, int format,
654 int use_local, LONGEST val);
656 extern void print_floating (const gdb_byte *valaddr, struct type *type,
657 struct ui_file *stream);
659 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
660 struct ui_file *stream);
662 extern int value_print (struct value *val, struct ui_file *stream,
663 const struct value_print_options *options);
665 extern void value_print_array_elements (struct value *val,
666 struct ui_file *stream, int format,
667 enum val_prettyprint pretty);
669 extern struct value *value_release_to_mark (struct value *mark);
671 extern int val_print (struct type *type, const gdb_byte *valaddr,
672 int embedded_offset, CORE_ADDR address,
673 struct ui_file *stream, int recurse,
674 const struct value *val,
675 const struct value_print_options *options,
676 const struct language_defn *language);
678 extern int common_val_print (struct value *val,
679 struct ui_file *stream, int recurse,
680 const struct value_print_options *options,
681 const struct language_defn *language);
683 extern int val_print_string (struct type *elttype, CORE_ADDR addr, int len,
684 struct ui_file *stream,
685 const struct value_print_options *options);
687 extern void print_variable_and_value (const char *name,
689 struct frame_info *frame,
690 struct ui_file *stream,
693 extern int check_field (struct type *, const char *);
695 extern void typedef_print (struct type *type, struct symbol *news,
696 struct ui_file *stream);
698 extern char *internalvar_name (struct internalvar *var);
700 extern void preserve_values (struct objfile *);
704 extern struct value *value_copy (struct value *);
706 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
710 extern struct value *varying_to_slice (struct value *);
712 extern struct value *value_slice (struct value *, int, int);
714 extern struct value *value_literal_complex (struct value *, struct value *,
717 extern struct value *find_function_in_inferior (const char *,
720 extern struct value *value_allocate_space_in_inferior (int);
722 extern struct value *value_of_local (const char *name, int complain);
724 extern struct value *value_subscripted_rvalue (struct value *array,
725 LONGEST index, int lowerbound);
727 /* User function handler. */
729 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
730 const struct language_defn *language,
733 struct value **argv);
735 void add_internal_function (const char *name, const char *doc,
736 internal_function_fn handler,
739 struct value *call_internal_function (struct gdbarch *gdbarch,
740 const struct language_defn *language,
741 struct value *function,
742 int argc, struct value **argv);
744 char *value_internal_function_name (struct value *);
746 #endif /* !defined (VALUE_H) */