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 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 /* The structure which defines the type of a value. It should never
36 be possible for a program lval value to survive over a call to the
37 inferior (i.e. to be put into the history list or an internal
42 /* Values are stored in a chain, so that they can be deleted easily
43 over calls to the inferior. Values assigned to internal variables
44 or put into the value history are taken off this list. */
46 struct value *value_next (struct value *);
48 /* Type of the value. */
50 extern struct type *value_type (struct value *);
52 /* This is being used to change the type of an existing value, that
53 code should instead be creating a new value with the changed type
54 (but possibly shared content). */
56 extern void deprecated_set_value_type (struct value *value,
59 /* Only used for bitfields; number of bits contained in them. */
61 extern int value_bitsize (struct value *);
62 extern void set_value_bitsize (struct value *, int bit);
64 /* Only used for bitfields; position of start of field. For
65 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
66 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
68 extern int value_bitpos (struct value *);
69 extern void set_value_bitpos (struct value *, int bit);
71 /* Describes offset of a value within lval of a structure in bytes.
72 If lval == lval_memory, this is an offset to the address. If lval
73 == lval_register, this is a further offset from location.address
74 within the registers structure. Note also the member
75 embedded_offset below. */
77 extern int value_offset (struct value *);
78 extern void set_value_offset (struct value *, int offset);
80 /* The comment from "struct value" reads: ``Is it modifiable? Only
81 relevant if lval != not_lval.''. Shouldn't the value instead be
82 not_lval and be done with it? */
84 extern int deprecated_value_modifiable (struct value *value);
85 extern void deprecated_set_value_modifiable (struct value *value,
88 /* If a value represents a C++ object, then the `type' field gives the
89 object's compile-time type. If the object actually belongs to some
90 class derived from `type', perhaps with other base classes and
91 additional members, then `type' is just a subobject of the real
92 thing, and the full object is probably larger than `type' would
95 If `type' is a dynamic class (i.e. one with a vtable), then GDB can
96 actually determine the object's run-time type by looking at the
97 run-time type information in the vtable. When this information is
98 available, we may elect to read in the entire object, for several
101 - When printing the value, the user would probably rather see the
102 full object, not just the limited portion apparent from the
105 - If `type' has virtual base classes, then even printing `type'
106 alone may require reaching outside the `type' portion of the
107 object to wherever the virtual base class has been stored.
109 When we store the entire object, `enclosing_type' is the run-time
110 type -- the complete object -- and `embedded_offset' is the offset
111 of `type' within that larger type, in bytes. The value_contents()
112 macro takes `embedded_offset' into account, so most GDB code
113 continues to see the `type' portion of the value, just as the
116 If `type' is a pointer to an object, then `enclosing_type' is a
117 pointer to the object's run-time type, and `pointed_to_offset' is
118 the offset in bytes from the full object to the pointed-to object
119 -- that is, the value `embedded_offset' would have if we followed
120 the pointer and fetched the complete object. (I don't really see
121 the point. Why not just determine the run-time type when you
122 indirect, and avoid the special case? The contents don't matter
123 until you indirect anyway.)
125 If we're not doing anything fancy, `enclosing_type' is equal to
126 `type', and `embedded_offset' is zero, so everything works
129 extern struct type *value_enclosing_type (struct value *);
130 extern struct value *value_change_enclosing_type (struct value *val,
131 struct type *new_type);
132 extern int value_pointed_to_offset (struct value *value);
133 extern void set_value_pointed_to_offset (struct value *value, int val);
134 extern int value_embedded_offset (struct value *value);
135 extern void set_value_embedded_offset (struct value *value, int val);
137 /* If zero, contents of this value are in the contents field. If
138 nonzero, contents are in inferior memory at address in the
139 location.address field plus the offset field (and the lval field
140 should be lval_memory).
142 WARNING: This field is used by the code which handles watchpoints
143 (see breakpoint.c) to decide whether a particular value can be
144 watched by hardware watchpoints. If the lazy flag is set for some
145 member of a value chain, it is assumed that this member of the
146 chain doesn't need to be watched as part of watching the value
147 itself. This is how GDB avoids watching the entire struct or array
148 when the user wants to watch a single struct member or array
149 element. If you ever change the way lazy flag is set and reset, be
150 sure to consider this use as well! */
152 extern int value_lazy (struct value *);
153 extern void set_value_lazy (struct value *value, int val);
155 /* value_contents() and value_contents_raw() both return the address
156 of the gdb buffer used to hold a copy of the contents of the lval.
157 value_contents() is used when the contents of the buffer are needed
158 -- it uses value_fetch_lazy() to load the buffer from the process
159 being debugged if it hasn't already been loaded
160 (value_contents_writeable() is used when a writeable but fetched
161 buffer is required).. value_contents_raw() is used when data is
162 being stored into the buffer, or when it is certain that the
163 contents of the buffer are valid.
165 Note: The contents pointer is adjusted by the offset required to
166 get to the real subobject, if the value happens to represent
167 something embedded in a larger run-time object. */
169 extern gdb_byte *value_contents_raw (struct value *);
171 /* Actual contents of the value. For use of this value; setting it
172 uses the stuff above. Not valid if lazy is nonzero. Target
173 byte-order. We force it to be aligned properly for any possible
174 value. Note that a value therefore extends beyond what is
177 extern const gdb_byte *value_contents (struct value *);
178 extern gdb_byte *value_contents_writeable (struct value *);
180 /* The ALL variants of the above two macros do not adjust the returned
181 pointer by the embedded_offset value. */
183 extern gdb_byte *value_contents_all_raw (struct value *);
184 extern const gdb_byte *value_contents_all (struct value *);
186 extern int value_fetch_lazy (struct value *val);
187 extern int value_contents_equal (struct value *val1, struct value *val2);
189 /* If nonzero, this is the value of a variable which does not actually
190 exist in the program. */
191 extern int value_optimized_out (struct value *value);
192 extern void set_value_optimized_out (struct value *value, int val);
194 /* Set or return field indicating whether a variable is initialized or
195 not, based on debugging information supplied by the compiler.
196 1 = initialized; 0 = uninitialized. */
197 extern int value_initialized (struct value *);
198 extern void set_value_initialized (struct value *, int);
200 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
201 single value might have multiple LVALs), this hacked interface is
202 limited to just the first PIECE. Expect further change. */
203 /* Type of value; either not an lval, or one of the various different
204 possible kinds of lval. */
205 extern enum lval_type *deprecated_value_lval_hack (struct value *);
206 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
208 /* If lval == lval_memory, this is the address in the inferior. If
209 lval == lval_register, this is the byte offset into the registers
211 extern CORE_ADDR *deprecated_value_address_hack (struct value *);
212 #define VALUE_ADDRESS(val) (*deprecated_value_address_hack (val))
214 /* Pointer to internal variable. */
215 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
216 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
218 /* Frame register value is relative to. This will be described in the
219 lval enum above as "lval_register". */
220 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
221 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
223 /* Register number if the value is from a register. */
224 extern short *deprecated_value_regnum_hack (struct value *);
225 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
227 /* Convert a REF to the object referenced. */
229 extern struct value *coerce_ref (struct value *value);
231 /* If ARG is an array, convert it to a pointer.
232 If ARG is an enum, convert it to an integer.
233 If ARG is a function, convert it to a function pointer.
235 References are dereferenced. */
237 extern struct value *coerce_array (struct value *value);
238 extern struct value *coerce_number (struct value *value);
240 /* If ARG is an enum, convert it to an integer. */
242 extern struct value *coerce_enum (struct value *value);
244 /* Internal variables (variables for convenience of use of debugger)
245 are recorded as a chain of these structures. */
249 struct internalvar *next;
258 #include "gdbtypes.h"
259 #include "expression.h"
264 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
266 extern LONGEST value_as_long (struct value *val);
267 extern DOUBLEST value_as_double (struct value *val);
268 extern CORE_ADDR value_as_address (struct value *val);
270 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
271 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
273 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
274 extern LONGEST unpack_field_as_long (struct type *type,
275 const gdb_byte *valaddr,
278 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
280 extern struct value *value_from_longest (struct type *type, LONGEST num);
281 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
282 extern struct value *value_from_double (struct type *type, DOUBLEST num);
283 extern struct value *value_from_decfloat (struct type *type,
284 const gdb_byte *decbytes);
285 extern struct value *value_from_string (char *string);
287 extern struct value *value_at (struct type *type, CORE_ADDR addr);
288 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
290 extern struct value *default_value_from_register (struct type *type,
292 struct frame_info *frame);
294 extern struct value *value_from_register (struct type *type, int regnum,
295 struct frame_info *frame);
297 extern CORE_ADDR address_from_register (struct type *type, int regnum,
298 struct frame_info *frame);
300 extern struct value *value_of_variable (struct symbol *var, struct block *b);
302 extern struct value *value_of_register (int regnum, struct frame_info *frame);
304 extern int symbol_read_needs_frame (struct symbol *);
306 extern struct value *read_var_value (struct symbol *var,
307 struct frame_info *frame);
309 extern struct value *locate_var_value (struct symbol *var,
310 struct frame_info *frame);
312 extern struct value *allocate_value (struct type *type);
314 extern struct value *allocate_repeat_value (struct type *type, int count);
316 extern struct value *value_mark (void);
318 extern void value_free_to_mark (struct value *mark);
320 extern struct value *value_string (char *ptr, int len);
321 extern struct value *value_bitstring (char *ptr, int len);
323 extern struct value *value_array (int lowbound, int highbound,
324 struct value **elemvec);
326 extern struct value *value_concat (struct value *arg1, struct value *arg2);
328 extern struct value *value_binop (struct value *arg1, struct value *arg2,
331 extern struct value *value_add (struct value *arg1, struct value *arg2);
333 extern struct value *value_sub (struct value *arg1, struct value *arg2);
335 extern int value_must_coerce_to_target (struct value *arg1);
337 extern struct value *value_coerce_to_target (struct value *arg1);
339 extern struct value *value_coerce_array (struct value *arg1);
341 extern struct value *value_coerce_function (struct value *arg1);
343 extern struct value *value_ind (struct value *arg1);
345 extern struct value *value_addr (struct value *arg1);
347 extern struct value *value_ref (struct value *arg1);
349 extern struct value *value_assign (struct value *toval,
350 struct value *fromval);
352 extern struct value *value_pos (struct value *arg1);
354 extern struct value *value_neg (struct value *arg1);
356 extern struct value *value_complement (struct value *arg1);
358 extern struct value *value_struct_elt (struct value **argp,
360 char *name, int *static_memfuncp,
363 extern struct value *value_aggregate_elt (struct type *curtype,
368 extern struct value *value_static_field (struct type *type, int fieldno);
370 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
372 struct type **, int *);
374 extern int find_overload_match (struct type **arg_types, int nargs,
375 char *name, int method, int lax,
376 struct value **objp, struct symbol *fsym,
377 struct value **valp, struct symbol **symp,
380 extern struct value *value_field (struct value *arg1, int fieldno);
382 extern struct value *value_primitive_field (struct value *arg1, int offset,
384 struct type *arg_type);
387 extern struct type *value_rtti_target_type (struct value *, int *, int *,
390 extern struct value *value_full_object (struct value *, struct type *, int,
393 extern struct value *value_cast_pointers (struct type *, struct value *);
395 extern struct value *value_cast (struct type *type, struct value *arg2);
397 extern struct value *value_zero (struct type *type, enum lval_type lv);
399 extern struct value *value_one (struct type *type, enum lval_type lv);
401 extern struct value *value_repeat (struct value *arg1, int count);
403 extern struct value *value_subscript (struct value *array, struct value *idx);
405 extern struct value *register_value_being_returned (struct type *valtype,
406 struct regcache *retbuf);
408 extern struct value *value_in (struct value *element, struct value *set);
410 extern int value_bit_index (struct type *type, const gdb_byte *addr,
413 extern int using_struct_return (struct type *func_type,
414 struct type *value_type);
416 extern struct value *evaluate_expression (struct expression *exp);
418 extern struct value *evaluate_type (struct expression *exp);
420 extern struct value *evaluate_subexp_with_coercion (struct expression *,
423 extern struct value *parse_and_eval (char *exp);
425 extern struct value *parse_to_comma_and_eval (char **expp);
427 extern struct type *parse_and_eval_type (char *p, int length);
429 extern CORE_ADDR parse_and_eval_address (char *exp);
431 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
433 extern LONGEST parse_and_eval_long (char *exp);
435 extern struct value *access_value_history (int num);
437 extern struct value *value_of_internalvar (struct internalvar *var);
439 extern void set_internalvar (struct internalvar *var, struct value *val);
441 extern void set_internalvar_component (struct internalvar *var,
443 int bitpos, int bitsize,
444 struct value *newvalue);
446 extern struct internalvar *lookup_only_internalvar (char *name);
448 extern struct internalvar *create_internalvar (char *name);
450 extern struct internalvar *lookup_internalvar (char *name);
452 extern int value_equal (struct value *arg1, struct value *arg2);
454 extern int value_less (struct value *arg1, struct value *arg2);
456 extern int value_logical_not (struct value *arg1);
460 extern struct value *value_of_this (int complain);
462 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
464 enum exp_opcode otherop,
467 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
470 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
471 int j, struct type *type, int offset);
473 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
476 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
478 extern int destructor_name_p (const char *name, const struct type *type);
480 #define value_free(val) xfree (val)
482 extern void free_all_values (void);
484 extern void release_value (struct value *val);
486 extern int record_latest_value (struct value *val);
488 extern void modify_field (gdb_byte *addr, LONGEST fieldval, int bitpos,
491 extern void type_print (struct type *type, char *varstring,
492 struct ui_file *stream, int show);
494 extern gdb_byte *baseclass_addr (struct type *type, int index,
496 struct value **valuep, int *errp);
498 extern void print_longest (struct ui_file *stream, int format,
499 int use_local, LONGEST val);
501 extern void print_floating (const gdb_byte *valaddr, struct type *type,
502 struct ui_file *stream);
504 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
505 struct ui_file *stream);
507 extern int value_print (struct value *val, struct ui_file *stream, int format,
508 enum val_prettyprint pretty);
510 extern void value_print_array_elements (struct value *val,
511 struct ui_file *stream, int format,
512 enum val_prettyprint pretty);
514 extern struct value *value_release_to_mark (struct value *mark);
516 extern int val_print (struct type *type, const gdb_byte *valaddr,
517 int embedded_offset, CORE_ADDR address,
518 struct ui_file *stream, int format,
519 int deref_ref, int recurse,
520 enum val_prettyprint pretty);
522 extern int common_val_print (struct value *val,
523 struct ui_file *stream, int format,
524 int deref_ref, int recurse,
525 enum val_prettyprint pretty);
527 extern int val_print_string (CORE_ADDR addr, int len, int width,
528 struct ui_file *stream);
530 extern void print_variable_value (struct symbol *var,
531 struct frame_info *frame,
532 struct ui_file *stream);
534 extern int check_field (struct type *, const char *);
536 extern void typedef_print (struct type *type, struct symbol *news,
537 struct ui_file *stream);
539 extern char *internalvar_name (struct internalvar *var);
541 extern void preserve_values (struct objfile *);
545 extern struct value *value_copy (struct value *);
549 extern struct value *varying_to_slice (struct value *);
551 extern struct value *value_slice (struct value *, int, int);
553 extern struct value *value_literal_complex (struct value *, struct value *,
556 extern struct value *find_function_in_inferior (const char *);
558 extern struct value *value_allocate_space_in_inferior (int);
560 extern struct value *value_of_local (const char *name, int complain);
562 extern struct value * value_subscripted_rvalue (struct value *array, struct value *idx, int lowerbound);
563 #endif /* !defined (VALUE_H) */