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 void set_value_enclosing_type (struct value *val,
140 struct type *new_type);
142 extern int value_pointed_to_offset (struct value *value);
143 extern void set_value_pointed_to_offset (struct value *value, int val);
144 extern int value_embedded_offset (struct value *value);
145 extern void set_value_embedded_offset (struct value *value, int val);
147 /* For lval_computed values, this structure holds functions used to
148 retrieve and set the value (or portions of the value).
150 For each function, 'V' is the 'this' pointer: an lval_funcs
151 function F may always assume that the V it receives is an
152 lval_computed value, and has F in the appropriate slot of its
153 lval_funcs structure. */
157 /* Fill in VALUE's contents. This is used to "un-lazy" values. If
158 a problem arises in obtaining VALUE's bits, this function should
160 void (*read) (struct value *v);
162 /* Handle an assignment TOVAL = FROMVAL by writing the value of
163 FROMVAL to TOVAL's location. The contents of TOVAL have not yet
164 been updated. If a problem arises in doing so, this function
165 should call 'error'. */
166 void (*write) (struct value *toval, struct value *fromval);
168 /* Check the validity of some bits in VALUE. This should return 1
169 if all the bits starting at OFFSET and extending for LENGTH bits
170 are valid, or 0 if any bit is invalid. */
171 int (*check_validity) (const struct value *value, int offset, int length);
173 /* Return 1 if any bit in VALUE is valid, 0 if they are all invalid. */
174 int (*check_any_valid) (const struct value *value);
176 /* Return a duplicate of VALUE's closure, for use in a new value.
177 This may simply return the same closure, if VALUE's is
178 reference-counted or statically allocated.
180 This may be NULL, in which case VALUE's closure is re-used in the
182 void *(*copy_closure) (const struct value *v);
184 /* Drop VALUE's reference to its closure. Maybe this frees the
185 closure; maybe this decrements a reference count; maybe the
186 closure is statically allocated and this does nothing.
188 This may be NULL, in which case no action is taken to free
190 void (*free_closure) (struct value *v);
193 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
194 and closure CLOSURE. */
196 extern struct value *allocate_computed_value (struct type *type,
197 struct lval_funcs *funcs,
200 /* If VALUE is lval_computed, return its lval_funcs structure. */
202 extern struct lval_funcs *value_computed_funcs (struct value *value);
204 /* If VALUE is lval_computed, return its closure. The meaning of the
205 returned value depends on the functions VALUE uses. */
207 extern void *value_computed_closure (const struct value *value);
209 /* If zero, contents of this value are in the contents field. If
210 nonzero, contents are in inferior. If the lval field is lval_memory,
211 the contents are in inferior memory at location.address plus offset.
212 The lval field may also be lval_register.
214 WARNING: This field is used by the code which handles watchpoints
215 (see breakpoint.c) to decide whether a particular value can be
216 watched by hardware watchpoints. If the lazy flag is set for some
217 member of a value chain, it is assumed that this member of the
218 chain doesn't need to be watched as part of watching the value
219 itself. This is how GDB avoids watching the entire struct or array
220 when the user wants to watch a single struct member or array
221 element. If you ever change the way lazy flag is set and reset, be
222 sure to consider this use as well! */
224 extern int value_lazy (struct value *);
225 extern void set_value_lazy (struct value *value, int val);
227 extern int value_stack (struct value *);
228 extern void set_value_stack (struct value *value, int val);
230 /* value_contents() and value_contents_raw() both return the address
231 of the gdb buffer used to hold a copy of the contents of the lval.
232 value_contents() is used when the contents of the buffer are needed
233 -- it uses value_fetch_lazy() to load the buffer from the process
234 being debugged if it hasn't already been loaded
235 (value_contents_writeable() is used when a writeable but fetched
236 buffer is required).. value_contents_raw() is used when data is
237 being stored into the buffer, or when it is certain that the
238 contents of the buffer are valid.
240 Note: The contents pointer is adjusted by the offset required to
241 get to the real subobject, if the value happens to represent
242 something embedded in a larger run-time object. */
244 extern gdb_byte *value_contents_raw (struct value *);
246 /* Actual contents of the value. For use of this value; setting it
247 uses the stuff above. Not valid if lazy is nonzero. Target
248 byte-order. We force it to be aligned properly for any possible
249 value. Note that a value therefore extends beyond what is
252 extern const gdb_byte *value_contents (struct value *);
253 extern gdb_byte *value_contents_writeable (struct value *);
255 /* The ALL variants of the above two macros do not adjust the returned
256 pointer by the embedded_offset value. */
258 extern gdb_byte *value_contents_all_raw (struct value *);
259 extern const gdb_byte *value_contents_all (struct value *);
261 /* Like value_contents_all, but does not require that the returned
262 bits be valid. This should only be used in situations where you
263 plan to check the validity manually. */
264 extern const gdb_byte *value_contents_for_printing (struct value *value);
266 extern int value_fetch_lazy (struct value *val);
267 extern int value_contents_equal (struct value *val1, struct value *val2);
269 /* If nonzero, this is the value of a variable which does not actually
270 exist in the program. */
271 extern int value_optimized_out (struct value *value);
272 extern void set_value_optimized_out (struct value *value, int val);
274 /* Like value_optimized_out, but return false if any bit in the object
276 extern int value_entirely_optimized_out (const struct value *value);
278 /* Set or return field indicating whether a variable is initialized or
279 not, based on debugging information supplied by the compiler.
280 1 = initialized; 0 = uninitialized. */
281 extern int value_initialized (struct value *);
282 extern void set_value_initialized (struct value *, int);
284 /* Set COMPONENT's location as appropriate for a component of WHOLE
285 --- regardless of what kind of lvalue WHOLE is. */
286 extern void set_value_component_location (struct value *component,
287 const struct value *whole);
289 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
290 single value might have multiple LVALs), this hacked interface is
291 limited to just the first PIECE. Expect further change. */
292 /* Type of value; either not an lval, or one of the various different
293 possible kinds of lval. */
294 extern enum lval_type *deprecated_value_lval_hack (struct value *);
295 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
297 /* If lval == lval_memory, return the address in the inferior. If
298 lval == lval_register, return the byte offset into the registers
299 structure. Otherwise, return 0. The returned address
300 includes the offset, if any. */
301 extern CORE_ADDR value_address (struct value *);
303 /* Like value_address, except the result does not include value's
305 extern CORE_ADDR value_raw_address (struct value *);
307 /* Set the address of a value. */
308 extern void set_value_address (struct value *, CORE_ADDR);
310 /* Pointer to internal variable. */
311 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
312 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
314 /* Frame register value is relative to. This will be described in the
315 lval enum above as "lval_register". */
316 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
317 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
319 /* Register number if the value is from a register. */
320 extern short *deprecated_value_regnum_hack (struct value *);
321 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
323 /* Convert a REF to the object referenced. */
325 extern struct value *coerce_ref (struct value *value);
327 /* If ARG is an array, convert it to a pointer.
328 If ARG is a function, convert it to a function pointer.
330 References are dereferenced. */
332 extern struct value *coerce_array (struct value *value);
334 /* Given a value, determine whether the bits starting at OFFSET and
335 extending for LENGTH bits are valid. This returns nonzero if all
336 bits in the given range are valid, zero if any bit is invalid. */
338 extern int value_bits_valid (const struct value *value,
339 int offset, int length);
344 #include "gdbtypes.h"
345 #include "expression.h"
350 extern void print_address_demangle (struct gdbarch *, CORE_ADDR,
351 struct ui_file *, int);
353 extern LONGEST value_as_long (struct value *val);
354 extern DOUBLEST value_as_double (struct value *val);
355 extern CORE_ADDR value_as_address (struct value *val);
357 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
358 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
360 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
361 LONGEST unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
362 int bitpos, int bitsize);
363 extern LONGEST unpack_field_as_long (struct type *type,
364 const gdb_byte *valaddr,
367 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
369 extern struct value *value_from_longest (struct type *type, LONGEST num);
370 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
371 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
372 extern struct value *value_from_double (struct type *type, DOUBLEST num);
373 extern struct value *value_from_decfloat (struct type *type,
374 const gdb_byte *decbytes);
376 extern struct value *value_at (struct type *type, CORE_ADDR addr);
377 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
379 extern struct value *value_from_contents_and_address (struct type *,
383 extern struct value *default_value_from_register (struct type *type,
385 struct frame_info *frame);
387 extern struct value *value_from_register (struct type *type, int regnum,
388 struct frame_info *frame);
390 extern CORE_ADDR address_from_register (struct type *type, int regnum,
391 struct frame_info *frame);
393 extern struct value *value_of_variable (struct symbol *var, struct block *b);
395 extern struct value *address_of_variable (struct symbol *var, struct block *b);
397 extern struct value *value_of_register (int regnum, struct frame_info *frame);
399 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
401 extern int symbol_read_needs_frame (struct symbol *);
403 extern struct value *read_var_value (struct symbol *var,
404 struct frame_info *frame);
406 extern struct value *allocate_value (struct type *type);
407 extern struct value *allocate_value_lazy (struct type *type);
408 extern void allocate_value_contents (struct value *value);
410 extern struct value *allocate_repeat_value (struct type *type, int count);
412 extern struct value *value_mark (void);
414 extern void value_free_to_mark (struct value *mark);
416 extern struct value *value_cstring (char *ptr, int len,
417 struct type *char_type);
418 extern struct value *value_string (char *ptr, int len,
419 struct type *char_type);
420 extern struct value *value_bitstring (char *ptr, int len,
421 struct type *index_type);
423 extern struct value *value_array (int lowbound, int highbound,
424 struct value **elemvec);
426 extern struct value *value_concat (struct value *arg1, struct value *arg2);
428 extern struct value *value_binop (struct value *arg1, struct value *arg2,
431 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
433 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
435 extern int value_must_coerce_to_target (struct value *arg1);
437 extern struct value *value_coerce_to_target (struct value *arg1);
439 extern struct value *value_coerce_array (struct value *arg1);
441 extern struct value *value_coerce_function (struct value *arg1);
443 extern struct value *value_ind (struct value *arg1);
445 extern struct value *value_addr (struct value *arg1);
447 extern struct value *value_ref (struct value *arg1);
449 extern struct value *value_assign (struct value *toval,
450 struct value *fromval);
452 extern struct value *value_pos (struct value *arg1);
454 extern struct value *value_neg (struct value *arg1);
456 extern struct value *value_complement (struct value *arg1);
458 extern struct value *value_struct_elt (struct value **argp,
460 const char *name, int *static_memfuncp,
463 extern struct value *value_aggregate_elt (struct type *curtype,
465 struct type *expect_type,
469 extern struct value *value_static_field (struct type *type, int fieldno);
471 extern struct fn_field *value_find_oload_method_list (struct value **,
474 struct type **, int *);
476 enum oload_search_type { NON_METHOD, METHOD, BOTH };
478 extern int find_overload_match (struct type **arg_types, int nargs,
480 enum oload_search_type method, int lax,
481 struct value **objp, struct symbol *fsym,
482 struct value **valp, struct symbol **symp,
483 int *staticp, const int no_adl);
485 extern struct value *value_field (struct value *arg1, int fieldno);
487 extern struct value *value_primitive_field (struct value *arg1, int offset,
489 struct type *arg_type);
492 extern struct type *value_rtti_target_type (struct value *, int *, int *,
495 extern struct value *value_full_object (struct value *, struct type *, int,
498 extern struct value *value_cast_pointers (struct type *, struct value *);
500 extern struct value *value_cast (struct type *type, struct value *arg2);
502 extern struct value *value_reinterpret_cast (struct type *type,
505 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
507 extern struct value *value_zero (struct type *type, enum lval_type lv);
509 extern struct value *value_one (struct type *type, enum lval_type lv);
511 extern struct value *value_repeat (struct value *arg1, int count);
513 extern struct value *value_subscript (struct value *array, LONGEST index);
515 extern struct value *value_bitstring_subscript (struct type *type,
516 struct value *bitstring,
519 extern struct value *register_value_being_returned (struct type *valtype,
520 struct regcache *retbuf);
522 extern int value_in (struct value *element, struct value *set);
524 extern int value_bit_index (struct type *type, const gdb_byte *addr,
527 extern int using_struct_return (struct gdbarch *gdbarch,
528 struct type *func_type,
529 struct type *value_type);
531 extern struct value *evaluate_expression (struct expression *exp);
533 extern struct value *evaluate_type (struct expression *exp);
535 extern struct value *evaluate_subexp (struct type *expect_type,
536 struct expression *exp,
537 int *pos, enum noside noside);
539 extern struct value *evaluate_subexpression_type (struct expression *exp,
542 extern void fetch_subexp_value (struct expression *exp, int *pc,
543 struct value **valp, struct value **resultp,
544 struct value **val_chain);
546 extern char *extract_field_op (struct expression *exp, int *subexp);
548 extern struct value *evaluate_subexp_with_coercion (struct expression *,
551 extern struct value *parse_and_eval (char *exp);
553 extern struct value *parse_to_comma_and_eval (char **expp);
555 extern struct type *parse_and_eval_type (char *p, int length);
557 extern CORE_ADDR parse_and_eval_address (char *exp);
559 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
561 extern LONGEST parse_and_eval_long (char *exp);
563 extern void unop_promote (const struct language_defn *language,
564 struct gdbarch *gdbarch,
565 struct value **arg1);
567 extern void binop_promote (const struct language_defn *language,
568 struct gdbarch *gdbarch,
569 struct value **arg1, struct value **arg2);
571 extern struct value *access_value_history (int num);
573 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
574 struct internalvar *var);
576 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
578 extern void set_internalvar (struct internalvar *var, struct value *val);
580 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
582 extern void set_internalvar_string (struct internalvar *var,
585 extern void clear_internalvar (struct internalvar *var);
587 extern void set_internalvar_component (struct internalvar *var,
589 int bitpos, int bitsize,
590 struct value *newvalue);
592 extern struct internalvar *lookup_only_internalvar (const char *name);
594 extern struct internalvar *create_internalvar (const char *name);
596 typedef struct value * (*internalvar_make_value) (struct gdbarch *,
597 struct internalvar *);
598 extern struct internalvar *
599 create_internalvar_type_lazy (char *name, internalvar_make_value fun);
601 extern struct internalvar *lookup_internalvar (const char *name);
603 extern int value_equal (struct value *arg1, struct value *arg2);
605 extern int value_equal_contents (struct value *arg1, struct value *arg2);
607 extern int value_less (struct value *arg1, struct value *arg2);
609 extern int value_logical_not (struct value *arg1);
613 extern struct value *value_of_this (int complain);
615 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
617 enum exp_opcode otherop,
620 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
623 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
624 int j, struct type *type, int offset);
626 extern int binop_types_user_defined_p (enum exp_opcode op,
630 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
633 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
635 extern int destructor_name_p (const char *name, const struct type *type);
637 extern void value_incref (struct value *val);
639 extern void value_free (struct value *val);
641 extern void free_all_values (void);
643 extern void free_value_chain (struct value *v);
645 extern void release_value (struct value *val);
647 extern int record_latest_value (struct value *val);
649 extern void modify_field (struct type *type, gdb_byte *addr,
650 LONGEST fieldval, int bitpos, int bitsize);
652 extern void type_print (struct type *type, char *varstring,
653 struct ui_file *stream, int show);
655 extern char *type_to_string (struct type *type);
657 extern gdb_byte *baseclass_addr (struct type *type, int index,
659 struct value **valuep, int *errp);
661 extern void print_longest (struct ui_file *stream, int format,
662 int use_local, LONGEST val);
664 extern void print_floating (const gdb_byte *valaddr, struct type *type,
665 struct ui_file *stream);
667 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
668 struct ui_file *stream);
670 extern int value_print (struct value *val, struct ui_file *stream,
671 const struct value_print_options *options);
673 extern void value_print_array_elements (struct value *val,
674 struct ui_file *stream, int format,
675 enum val_prettyprint pretty);
677 extern struct value *value_release_to_mark (struct value *mark);
679 extern int val_print (struct type *type, const gdb_byte *valaddr,
680 int embedded_offset, CORE_ADDR address,
681 struct ui_file *stream, int recurse,
682 const struct value *val,
683 const struct value_print_options *options,
684 const struct language_defn *language);
686 extern int common_val_print (struct value *val,
687 struct ui_file *stream, int recurse,
688 const struct value_print_options *options,
689 const struct language_defn *language);
691 extern int val_print_string (struct type *elttype, const char *encoding,
692 CORE_ADDR addr, int len,
693 struct ui_file *stream,
694 const struct value_print_options *options);
696 extern void print_variable_and_value (const char *name,
698 struct frame_info *frame,
699 struct ui_file *stream,
702 extern int check_field (struct type *, const char *);
704 extern void typedef_print (struct type *type, struct symbol *news,
705 struct ui_file *stream);
707 extern char *internalvar_name (struct internalvar *var);
709 extern void preserve_values (struct objfile *);
713 extern struct value *value_copy (struct value *);
715 extern struct value *value_non_lval (struct value *);
717 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
721 extern struct value *varying_to_slice (struct value *);
723 extern struct value *value_slice (struct value *, int, int);
725 extern struct value *value_literal_complex (struct value *, struct value *,
728 extern struct value *find_function_in_inferior (const char *,
731 extern struct value *value_allocate_space_in_inferior (int);
733 extern struct value *value_of_local (const char *name, int complain);
735 extern struct value *value_subscripted_rvalue (struct value *array,
736 LONGEST index, int lowerbound);
738 /* User function handler. */
740 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
741 const struct language_defn *language,
744 struct value **argv);
746 void add_internal_function (const char *name, const char *doc,
747 internal_function_fn handler,
750 struct value *call_internal_function (struct gdbarch *gdbarch,
751 const struct language_defn *language,
752 struct value *function,
753 int argc, struct value **argv);
755 char *value_internal_function_name (struct value *);
757 #endif /* !defined (VALUE_H) */