1 /* Definitions for values of C expressions, for GDB.
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
5 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 2 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, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 #if !defined (VALUE_H)
28 #include "frame.h" /* For struct frame_id. */
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 /* Type of value; either not an lval, or one of the various
45 different possible kinds of lval. */
48 /* Is it modifiable? Only relevant if lval != not_lval. */
51 /* Location of value (if lval). */
54 /* If lval == lval_memory, this is the address in the inferior.
55 If lval == lval_register, this is the byte offset into the
56 registers structure. */
59 /* Pointer to internal variable. */
60 struct internalvar *internalvar;
63 /* Describes offset of a value within lval of a structure in bytes.
64 If lval == lval_memory, this is an offset to the address. If
65 lval == lval_register, this is a further offset from
66 location.address within the registers structure. Note also the
67 member embedded_offset below. */
70 /* Only used for bitfields; number of bits contained in them. */
73 /* Only used for bitfields; position of start of field. For
74 BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. For
75 BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
78 /* Frame register value is relative to. This will be described in
79 the lval enum above as "lval_register". */
80 struct frame_id frame_id;
82 /* Type of the value. */
85 /* If a value represents a C++ object, then the `type' field gives
86 the object's compile-time type. If the object actually belongs
87 to some class derived from `type', perhaps with other base
88 classes and additional members, then `type' is just a subobject
89 of the real thing, and the full object is probably larger than
92 If `type' is a dynamic class (i.e. one with a vtable), then GDB
93 can actually determine the object's run-time type by looking at
94 the run-time type information in the vtable. When this
95 information is available, we may elect to read in the entire
96 object, for several reasons:
98 - When printing the value, the user would probably rather see the
99 full object, not just the limited portion apparent from the
102 - If `type' has virtual base classes, then even printing `type'
103 alone may require reaching outside the `type' portion of the
104 object to wherever the virtual base class has been stored.
106 When we store the entire object, `enclosing_type' is the run-time
107 type -- the complete object -- and `embedded_offset' is the
108 offset of `type' within that larger type, in bytes. The
109 value_contents() macro takes `embedded_offset' into account, so
110 most GDB code continues to see the `type' portion of the value,
111 just as the inferior would.
113 If `type' is a pointer to an object, then `enclosing_type' is a
114 pointer to the object's run-time type, and `pointed_to_offset' is
115 the offset in bytes from the full object to the pointed-to object
116 -- that is, the value `embedded_offset' would have if we followed
117 the pointer and fetched the complete object. (I don't really see
118 the point. Why not just determine the run-time type when you
119 indirect, and avoid the special case? The contents don't matter
120 until you indirect anyway.)
122 If we're not doing anything fancy, `enclosing_type' is equal to
123 `type', and `embedded_offset' is zero, so everything works
125 struct type *enclosing_type;
127 int pointed_to_offset;
129 /* Values are stored in a chain, so that they can be deleted easily
130 over calls to the inferior. Values assigned to internal
131 variables or put into the value history are taken off this
135 /* Register number if the value is from a register. */
138 /* If zero, contents of this value are in the contents field. If
139 nonzero, contents are in inferior memory at address in the
140 location.address field plus the offset field (and the lval field
141 should be lval_memory).
143 WARNING: This field is used by the code which handles watchpoints
144 (see breakpoint.c) to decide whether a particular value can be
145 watched by hardware watchpoints. If the lazy flag is set for
146 some member of a value chain, it is assumed that this member of
147 the chain doesn't need to be watched as part of watching the
148 value itself. This is how GDB avoids watching the entire struct
149 or array when the user wants to watch a single struct member or
150 array element. If you ever change the way lazy flag is set and
151 reset, be sure to consider this use as well! */
154 /* If nonzero, this is the value of a variable which does not
155 actually exist in the program. */
158 /* Actual contents of the value. For use of this value; setting it
159 uses the stuff above. Not valid if lazy is nonzero. Target
160 byte-order. We force it to be aligned properly for any possible
161 value. Note that a value therefore extends beyond what is
165 bfd_byte contents[1];
166 DOUBLEST force_doublest_align;
167 LONGEST force_longest_align;
168 CORE_ADDR force_core_addr_align;
169 void *force_pointer_align;
171 /* Do not add any new members here -- contents above will trash
176 extern struct type *value_type (struct value *);
177 extern int value_bitsize (struct value *);
178 extern int value_bitpos (struct value *);
179 extern int value_offset (struct value *);
181 extern struct type *value_enclosing_type (struct value *);
182 extern int value_lazy (struct value *);
183 extern void set_value_lazy (struct value *value, int val);
185 /* value_contents() and value_contents_raw() both return the address
186 of the gdb buffer used to hold a copy of the contents of the lval.
187 value_contents() is used when the contents of the buffer are needed
188 -- it uses value_fetch_lazy() to load the buffer from the process
189 being debugged if it hasn't already been loaded
190 (value_contents_writeable() is used when a writeable but fetched
191 buffer is required).. value_contents_raw() is used when data is
192 being stored into the buffer, or when it is certain that the
193 contents of the buffer are valid.
195 Note: The contents pointer is adjusted by the offset required to
196 get to the real subobject, if the value happens to represent
197 something embedded in a larger run-time object. */
199 extern bfd_byte *value_contents_raw (struct value *);
200 extern const bfd_byte *value_contents (struct value *);
201 extern bfd_byte *value_contents_writeable (struct value *);
203 /* The ALL variants of the above two macros do not adjust the returned
204 pointer by the embedded_offset value. */
206 extern bfd_byte *value_contents_all_raw (struct value *);
207 extern const bfd_byte *value_contents_all (struct value *);
209 extern int value_fetch_lazy (struct value *val);
211 #define VALUE_LVAL(val) (val)->lval
212 #define VALUE_ADDRESS(val) (val)->location.address
213 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
214 #define VALUE_FRAME_ID(val) ((val)->frame_id)
215 #define VALUE_REGNUM(val) (val)->regnum
216 extern int value_optimized_out (struct value *value);
217 extern void set_value_optimized_out (struct value *value, int val);
218 extern int value_embedded_offset (struct value *value);
219 extern void set_value_embedded_offset (struct value *value, int val);
220 extern int value_pointed_to_offset (struct value *value);
221 extern void set_value_pointed_to_offset (struct value *value, int val);
223 /* Convert a REF to the object referenced. */
225 extern struct value *coerce_ref (struct value *value);
227 /* If ARG is an array, convert it to a pointer.
228 If ARG is an enum, convert it to an integer.
229 If ARG is a function, convert it to a function pointer.
231 References are dereferenced. */
233 extern struct value *coerce_array (struct value *value);
234 extern struct value *coerce_number (struct value *value);
236 /* If ARG is an enum, convert it to an integer. */
238 extern struct value *coerce_enum (struct value *value);
240 /* Internal variables (variables for convenience of use of debugger)
241 are recorded as a chain of these structures. */
245 struct internalvar *next;
250 /* Pointer to member function. Depends on compiler implementation. */
252 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
253 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
254 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
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 char *valaddr);
271 extern DOUBLEST unpack_double (struct type *type, const char *valaddr,
273 extern CORE_ADDR unpack_pointer (struct type *type, const char *valaddr);
274 extern LONGEST unpack_field_as_long (struct type *type, const char *valaddr,
277 extern struct value *value_from_longest (struct type *type, LONGEST num);
278 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
279 extern struct value *value_from_double (struct type *type, DOUBLEST num);
280 extern struct value *value_from_string (char *string);
282 extern struct value *value_at (struct type *type, CORE_ADDR addr);
283 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
285 extern struct value *value_from_register (struct type *type, int regnum,
286 struct frame_info *frame);
288 extern struct value *value_of_variable (struct symbol *var, struct block *b);
290 extern struct value *value_of_register (int regnum, struct frame_info *frame);
292 extern int symbol_read_needs_frame (struct symbol *);
294 extern struct value *read_var_value (struct symbol *var,
295 struct frame_info *frame);
297 extern struct value *locate_var_value (struct symbol *var,
298 struct frame_info *frame);
300 extern struct value *allocate_value (struct type *type);
302 extern struct value *allocate_repeat_value (struct type *type, int count);
304 extern struct value *value_change_enclosing_type (struct value *val,
305 struct type *new_type);
307 extern struct value *value_mark (void);
309 extern void value_free_to_mark (struct value *mark);
311 extern struct value *value_string (char *ptr, int len);
312 extern struct value *value_bitstring (char *ptr, int len);
314 extern struct value *value_array (int lowbound, int highbound,
315 struct value **elemvec);
317 extern struct value *value_concat (struct value *arg1, struct value *arg2);
319 extern struct value *value_binop (struct value *arg1, struct value *arg2,
322 extern struct value *value_add (struct value *arg1, struct value *arg2);
324 extern struct value *value_sub (struct value *arg1, struct value *arg2);
326 extern struct value *value_coerce_array (struct value *arg1);
328 extern struct value *value_coerce_function (struct value *arg1);
330 extern struct value *value_ind (struct value *arg1);
332 extern struct value *value_addr (struct value *arg1);
334 extern struct value *value_assign (struct value *toval,
335 struct value *fromval);
337 extern struct value *value_neg (struct value *arg1);
339 extern struct value *value_complement (struct value *arg1);
341 extern struct value *value_struct_elt (struct value **argp,
343 char *name, int *static_memfuncp,
346 extern struct value *value_aggregate_elt (struct type *curtype,
347 char *name, enum noside noside);
349 extern struct value *value_static_field (struct type *type, int fieldno);
351 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
353 struct type **, int *);
355 extern int find_overload_match (struct type **arg_types, int nargs,
356 char *name, int method, int lax,
357 struct value **objp, struct symbol *fsym,
358 struct value **valp, struct symbol **symp,
361 extern struct value *value_field (struct value *arg1, int fieldno);
363 extern struct value *value_primitive_field (struct value *arg1, int offset,
365 struct type *arg_type);
368 extern struct type *value_rtti_target_type (struct value *, int *, int *,
371 extern struct value *value_full_object (struct value *, struct type *, int,
374 extern struct value *value_cast (struct type *type, struct value *arg2);
376 extern struct value *value_zero (struct type *type, enum lval_type lv);
378 extern struct value *value_repeat (struct value *arg1, int count);
380 extern struct value *value_subscript (struct value *array, struct value *idx);
382 extern struct value *register_value_being_returned (struct type *valtype,
383 struct regcache *retbuf);
385 extern struct value *value_in (struct value *element, struct value *set);
387 extern int value_bit_index (struct type *type, const bfd_byte *addr,
390 extern int using_struct_return (struct type *value_type, int gcc_p);
392 extern struct value *evaluate_expression (struct expression *exp);
394 extern struct value *evaluate_type (struct expression *exp);
396 extern struct value *evaluate_subexp_with_coercion (struct expression *,
399 extern struct value *parse_and_eval (char *exp);
401 extern struct value *parse_to_comma_and_eval (char **expp);
403 extern struct type *parse_and_eval_type (char *p, int length);
405 extern CORE_ADDR parse_and_eval_address (char *exp);
407 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
409 extern LONGEST parse_and_eval_long (char *exp);
411 extern struct value *access_value_history (int num);
413 extern struct value *value_of_internalvar (struct internalvar *var);
415 extern void set_internalvar (struct internalvar *var, struct value *val);
417 extern void set_internalvar_component (struct internalvar *var,
419 int bitpos, int bitsize,
420 struct value *newvalue);
422 extern struct internalvar *lookup_internalvar (char *name);
424 extern int value_equal (struct value *arg1, struct value *arg2);
426 extern int value_less (struct value *arg1, struct value *arg2);
428 extern int value_logical_not (struct value *arg1);
432 extern struct value *value_of_this (int complain);
434 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
436 enum exp_opcode otherop,
439 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
442 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
443 int j, struct type *type, int offset);
445 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
448 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
450 extern int destructor_name_p (const char *name, const struct type *type);
452 #define value_free(val) xfree (val)
454 extern void free_all_values (void);
456 extern void release_value (struct value *val);
458 extern int record_latest_value (struct value *val);
460 extern void modify_field (char *addr, LONGEST fieldval, int bitpos,
463 extern void type_print (struct type *type, char *varstring,
464 struct ui_file *stream, int show);
466 extern char *baseclass_addr (struct type *type, int index, char *valaddr,
467 struct value **valuep, int *errp);
469 extern void print_longest (struct ui_file *stream, int format,
470 int use_local, LONGEST val);
472 extern void print_floating (const bfd_byte *valaddr, struct type *type,
473 struct ui_file *stream);
475 extern int value_print (struct value *val, struct ui_file *stream, int format,
476 enum val_prettyprint pretty);
478 extern void value_print_array_elements (struct value *val,
479 struct ui_file *stream, int format,
480 enum val_prettyprint pretty);
482 extern struct value *value_release_to_mark (struct value *mark);
484 extern int val_print (struct type *type, const bfd_byte *valaddr,
485 int embedded_offset, CORE_ADDR address,
486 struct ui_file *stream, int format,
487 int deref_ref, int recurse,
488 enum val_prettyprint pretty);
490 extern int val_print_string (CORE_ADDR addr, int len, int width,
491 struct ui_file *stream);
493 extern void print_variable_value (struct symbol *var,
494 struct frame_info *frame,
495 struct ui_file *stream);
497 extern int check_field (struct value *, const char *);
499 extern void typedef_print (struct type *type, struct symbol *news,
500 struct ui_file *stream);
502 extern char *internalvar_name (struct internalvar *var);
504 extern void clear_value_history (void);
506 extern void clear_internalvars (void);
510 extern struct value *value_copy (struct value *);
514 extern struct value *varying_to_slice (struct value *);
516 extern struct value *value_slice (struct value *, int, int);
518 extern struct value *value_literal_complex (struct value *, struct value *,
521 extern void find_rt_vbase_offset (struct type *, struct type *,
522 const bfd_byte *, int, int *, int *);
524 extern struct value *find_function_in_inferior (const char *);
526 extern struct value *value_allocate_space_in_inferior (int);
528 extern struct value *value_of_local (const char *name, int complain);
530 #endif /* !defined (VALUE_H) */