1/* Definitions for values of C expressions, for GDB.
2
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   Free Software Foundation, Inc.
6
7   This file is part of GDB.
8
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.
13
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.
18
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/>.  */
21
22#if !defined (VALUE_H)
23#define VALUE_H 1
24
25#include "doublest.h"
26#include "frame.h"		/* For struct frame_id.  */
27
28struct block;
29struct expression;
30struct regcache;
31struct symbol;
32struct type;
33struct ui_file;
34
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
38   variable).  */
39
40struct value;
41
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.  */
45
46struct value *value_next (struct value *);
47
48/* Type of the value.  */
49
50extern struct type *value_type (struct value *);
51
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).  */
55
56extern void deprecated_set_value_type (struct value *value,
57				       struct type *type);
58
59/* Only used for bitfields; number of bits contained in them.  */
60
61extern int value_bitsize (struct value *);
62extern void set_value_bitsize (struct value *, int bit);
63
64/* Only used for bitfields; position of start of field.  For
65   BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.  For
66   BITS_BIG_ENDIAN=1 targets, it is the position of the MSB.  */
67
68extern int value_bitpos (struct value *);
69extern void set_value_bitpos (struct value *, int bit);
70
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.  */
76
77extern int value_offset (struct value *);
78extern void set_value_offset (struct value *, int offset);
79
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?  */
83
84extern int deprecated_value_modifiable (struct value *value);
85extern void deprecated_set_value_modifiable (struct value *value,
86					     int modifiable);
87
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
93   suggest.
94
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
99   reasons:
100
101   - When printing the value, the user would probably rather see the
102     full object, not just the limited portion apparent from the
103     compile-time type.
104
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.
108
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
114   inferior would.
115
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.)
124
125   If we're not doing anything fancy, `enclosing_type' is equal to
126   `type', and `embedded_offset' is zero, so everything works
127   normally.  */
128
129extern struct type *value_enclosing_type (struct value *);
130extern struct value *value_change_enclosing_type (struct value *val,
131						  struct type *new_type);
132extern int value_pointed_to_offset (struct value *value);
133extern void set_value_pointed_to_offset (struct value *value, int val);
134extern int value_embedded_offset (struct value *value);
135extern void set_value_embedded_offset (struct value *value, int val);
136
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).
141
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!  */
151
152extern int value_lazy (struct value *);
153extern void set_value_lazy (struct value *value, int val);
154
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.
164
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.  */
168
169extern gdb_byte *value_contents_raw (struct value *);
170
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
175   declared here.  */
176
177extern const gdb_byte *value_contents (struct value *);
178extern gdb_byte *value_contents_writeable (struct value *);
179
180/* The ALL variants of the above two macros do not adjust the returned
181   pointer by the embedded_offset value.  */
182
183extern gdb_byte *value_contents_all_raw (struct value *);
184extern const gdb_byte *value_contents_all (struct value *);
185
186extern int value_fetch_lazy (struct value *val);
187extern int value_contents_equal (struct value *val1, struct value *val2);
188
189/* If nonzero, this is the value of a variable which does not actually
190   exist in the program.  */
191extern int value_optimized_out (struct value *value);
192extern void set_value_optimized_out (struct value *value, int val);
193
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.  */
197extern int value_initialized (struct value *);
198extern void set_value_initialized (struct value *, int);
199
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.  */
205extern enum lval_type *deprecated_value_lval_hack (struct value *);
206#define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
207
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
210   structure.  */
211extern CORE_ADDR *deprecated_value_address_hack (struct value *);
212#define VALUE_ADDRESS(val) (*deprecated_value_address_hack (val))
213
214/* Pointer to internal variable.  */
215extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
216#define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
217
218/* Frame register value is relative to.  This will be described in the
219   lval enum above as "lval_register".  */
220extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
221#define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
222
223/* Register number if the value is from a register.  */
224extern short *deprecated_value_regnum_hack (struct value *);
225#define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
226
227/* Convert a REF to the object referenced.  */
228
229extern struct value *coerce_ref (struct value *value);
230
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.
234
235   References are dereferenced.  */
236
237extern struct value *coerce_array (struct value *value);
238extern struct value *coerce_number (struct value *value);
239
240/* If ARG is an enum, convert it to an integer.  */
241
242extern struct value *coerce_enum (struct value *value);
243
244/* Internal variables (variables for convenience of use of debugger)
245   are recorded as a chain of these structures.  */
246
247struct internalvar
248{
249  struct internalvar *next;
250  char *name;
251  struct value *value;
252  int endian;
253};
254
255
256
257#include "symtab.h"
258#include "gdbtypes.h"
259#include "expression.h"
260
261struct frame_info;
262struct fn_field;
263
264extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
265
266extern LONGEST value_as_long (struct value *val);
267extern DOUBLEST value_as_double (struct value *val);
268extern CORE_ADDR value_as_address (struct value *val);
269
270extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
271extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
272			       int *invp);
273extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
274extern LONGEST unpack_field_as_long (struct type *type,
275				     const gdb_byte *valaddr,
276				     int fieldno);
277
278extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
279
280extern struct value *value_from_longest (struct type *type, LONGEST num);
281extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
282extern struct value *value_from_double (struct type *type, DOUBLEST num);
283extern struct value *value_from_string (char *string);
284
285extern struct value *value_at (struct type *type, CORE_ADDR addr);
286extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
287
288extern struct value *default_value_from_register (struct type *type,
289						  int regnum,
290						  struct frame_info *frame);
291
292extern struct value *value_from_register (struct type *type, int regnum,
293					  struct frame_info *frame);
294
295extern CORE_ADDR address_from_register (struct type *type, int regnum,
296					struct frame_info *frame);
297
298extern struct value *value_of_variable (struct symbol *var, struct block *b);
299
300extern struct value *value_of_register (int regnum, struct frame_info *frame);
301
302extern int symbol_read_needs_frame (struct symbol *);
303
304extern struct value *read_var_value (struct symbol *var,
305				     struct frame_info *frame);
306
307extern struct value *locate_var_value (struct symbol *var,
308				       struct frame_info *frame);
309
310extern struct value *allocate_value (struct type *type);
311
312extern struct value *allocate_repeat_value (struct type *type, int count);
313
314extern struct value *value_mark (void);
315
316extern void value_free_to_mark (struct value *mark);
317
318extern struct value *value_string (char *ptr, int len);
319extern struct value *value_bitstring (char *ptr, int len);
320
321extern struct value *value_array (int lowbound, int highbound,
322				  struct value **elemvec);
323
324extern struct value *value_concat (struct value *arg1, struct value *arg2);
325
326extern struct value *value_binop (struct value *arg1, struct value *arg2,
327				  enum exp_opcode op);
328
329extern struct value *value_add (struct value *arg1, struct value *arg2);
330
331extern struct value *value_sub (struct value *arg1, struct value *arg2);
332
333extern struct value *value_coerce_array (struct value *arg1);
334
335extern struct value *value_coerce_function (struct value *arg1);
336
337extern struct value *value_ind (struct value *arg1);
338
339extern struct value *value_addr (struct value *arg1);
340
341extern struct value *value_ref (struct value *arg1);
342
343extern struct value *value_assign (struct value *toval,
344				   struct value *fromval);
345
346extern struct value *value_pos (struct value *arg1);
347
348extern struct value *value_neg (struct value *arg1);
349
350extern struct value *value_complement (struct value *arg1);
351
352extern struct value *value_struct_elt (struct value **argp,
353				       struct value **args,
354				       char *name, int *static_memfuncp,
355				       char *err);
356
357extern struct value *value_aggregate_elt (struct type *curtype,
358					  char *name,
359					  int want_address,
360					  enum noside noside);
361
362extern struct value *value_static_field (struct type *type, int fieldno);
363
364extern struct fn_field *value_find_oload_method_list (struct value **, char *,
365						      int, int *,
366						      struct type **, int *);
367
368extern int find_overload_match (struct type **arg_types, int nargs,
369				char *name, int method, int lax,
370				struct value **objp, struct symbol *fsym,
371				struct value **valp, struct symbol **symp,
372				int *staticp);
373
374extern struct value *value_field (struct value *arg1, int fieldno);
375
376extern struct value *value_primitive_field (struct value *arg1, int offset,
377					    int fieldno,
378					    struct type *arg_type);
379
380
381extern struct type *value_rtti_target_type (struct value *, int *, int *,
382					    int *);
383
384extern struct value *value_full_object (struct value *, struct type *, int,
385					int, int);
386
387extern struct value *value_cast_pointers (struct type *, struct value *);
388
389extern struct value *value_cast (struct type *type, struct value *arg2);
390
391extern struct value *value_zero (struct type *type, enum lval_type lv);
392
393extern struct value *value_repeat (struct value *arg1, int count);
394
395extern struct value *value_subscript (struct value *array, struct value *idx);
396
397extern struct value *register_value_being_returned (struct type *valtype,
398						    struct regcache *retbuf);
399
400extern struct value *value_in (struct value *element, struct value *set);
401
402extern int value_bit_index (struct type *type, const gdb_byte *addr,
403			    int index);
404
405extern int using_struct_return (struct type *value_type, int gcc_p);
406
407extern struct value *evaluate_expression (struct expression *exp);
408
409extern struct value *evaluate_type (struct expression *exp);
410
411extern struct value *evaluate_subexp_with_coercion (struct expression *,
412						    int *, enum noside);
413
414extern struct value *parse_and_eval (char *exp);
415
416extern struct value *parse_to_comma_and_eval (char **expp);
417
418extern struct type *parse_and_eval_type (char *p, int length);
419
420extern CORE_ADDR parse_and_eval_address (char *exp);
421
422extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
423
424extern LONGEST parse_and_eval_long (char *exp);
425
426extern struct value *access_value_history (int num);
427
428extern struct value *value_of_internalvar (struct internalvar *var);
429
430extern void set_internalvar (struct internalvar *var, struct value *val);
431
432extern void set_internalvar_component (struct internalvar *var,
433				       int offset,
434				       int bitpos, int bitsize,
435				       struct value *newvalue);
436
437extern struct internalvar *lookup_internalvar (char *name);
438
439extern int value_equal (struct value *arg1, struct value *arg2);
440
441extern int value_less (struct value *arg1, struct value *arg2);
442
443extern int value_logical_not (struct value *arg1);
444
445/* C++ */
446
447extern struct value *value_of_this (int complain);
448
449extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
450				    enum exp_opcode op,
451				    enum exp_opcode otherop,
452				    enum noside noside);
453
454extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
455				   enum noside noside);
456
457extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
458				     int j, struct type *type, int offset);
459
460extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
461				 struct value *arg2);
462
463extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
464
465extern int destructor_name_p (const char *name, const struct type *type);
466
467#define value_free(val) xfree (val)
468
469extern void free_all_values (void);
470
471extern void release_value (struct value *val);
472
473extern int record_latest_value (struct value *val);
474
475extern void modify_field (gdb_byte *addr, LONGEST fieldval, int bitpos,
476			  int bitsize);
477
478extern void type_print (struct type *type, char *varstring,
479			struct ui_file *stream, int show);
480
481extern gdb_byte *baseclass_addr (struct type *type, int index,
482				 gdb_byte *valaddr,
483				 struct value **valuep, int *errp);
484
485extern void print_longest (struct ui_file *stream, int format,
486			   int use_local, LONGEST val);
487
488extern void print_floating (const gdb_byte *valaddr, struct type *type,
489			    struct ui_file *stream);
490
491extern int value_print (struct value *val, struct ui_file *stream, int format,
492			enum val_prettyprint pretty);
493
494extern void value_print_array_elements (struct value *val,
495					struct ui_file *stream, int format,
496					enum val_prettyprint pretty);
497
498extern struct value *value_release_to_mark (struct value *mark);
499
500extern int val_print (struct type *type, const gdb_byte *valaddr,
501		      int embedded_offset, CORE_ADDR address,
502		      struct ui_file *stream, int format,
503		      int deref_ref, int recurse,
504		      enum val_prettyprint pretty);
505
506extern int common_val_print (struct value *val,
507			     struct ui_file *stream, int format,
508			     int deref_ref, int recurse,
509			     enum val_prettyprint pretty);
510
511extern int val_print_string (CORE_ADDR addr, int len, int width,
512			     struct ui_file *stream);
513
514extern void print_variable_value (struct symbol *var,
515				  struct frame_info *frame,
516				  struct ui_file *stream);
517
518extern int check_field (struct value *, const char *);
519
520extern void typedef_print (struct type *type, struct symbol *news,
521			   struct ui_file *stream);
522
523extern char *internalvar_name (struct internalvar *var);
524
525extern void preserve_values (struct objfile *);
526
527/* From values.c */
528
529extern struct value *value_copy (struct value *);
530
531/* From valops.c */
532
533extern struct value *varying_to_slice (struct value *);
534
535extern struct value *value_slice (struct value *, int, int);
536
537extern struct value *value_literal_complex (struct value *, struct value *,
538					    struct type *);
539
540extern void find_rt_vbase_offset (struct type *, struct type *,
541				  const gdb_byte *, int, int *, int *);
542
543extern struct value *find_function_in_inferior (const char *);
544
545extern struct value *value_allocate_space_in_inferior (int);
546
547extern struct value *value_of_local (const char *name, int complain);
548
549#endif /* !defined (VALUE_H) */
550