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
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
;
62 /* Number of register. Only used with lval_reg_frame_relative. */
66 /* Describes offset of a value within lval of a structure in bytes.
67 If lval == lval_memory, this is an offset to the address.
68 If lval == lval_register, this is a further offset from
69 location.address within the registers structure.
70 Note also the member embedded_offset below. */
73 /* Only used for bitfields; number of bits contained in them. */
76 /* Only used for bitfields; position of start of field.
77 For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
78 For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
81 /* Frame value is relative to. In practice, this ID is only used if
82 the value is stored in several registers in other than the
83 current frame, and these registers have not all been saved at the
84 same place in memory. This will be described in the lval enum
85 above as "lval_reg_frame_relative". */
86 struct frame_id frame_id
;
88 /* Type of the value. */
91 /* If a value represents a C++ object, then the `type' field gives
92 the object's compile-time type. If the object actually belongs
93 to some class derived from `type', perhaps with other base
94 classes and additional members, then `type' is just a subobject
95 of the real thing, and the full object is probably larger than
98 If `type' is a dynamic class (i.e. one with a vtable), then GDB
99 can actually determine the object's run-time type by looking at
100 the run-time type information in the vtable. When this
101 information is available, we may elect to read in the entire
102 object, for several reasons:
104 - When printing the value, the user would probably rather see the
105 full object, not just the limited portion apparent from the
108 - If `type' has virtual base classes, then even printing `type'
109 alone may require reaching outside the `type' portion of the
110 object to wherever the virtual base class has been stored.
112 When we store the entire object, `enclosing_type' is the run-time
113 type -- the complete object -- and `embedded_offset' is the
114 offset of `type' within that larger type, in bytes. The
115 VALUE_CONTENTS macro takes `embedded_offset' into account, so
116 most GDB code continues to see the `type' portion of the value,
117 just as the inferior would.
119 If `type' is a pointer to an object, then `enclosing_type' is a
120 pointer to the object's run-time type, and `pointed_to_offset' is
121 the offset in bytes from the full object to the pointed-to object
122 -- that is, the value `embedded_offset' would have if we
123 followed the pointer and fetched the complete object. (I don't
124 really see the point. Why not just determine the run-time type
125 when you indirect, and avoid the special case? The contents
126 don't matter until you indirect anyway.)
128 If we're not doing anything fancy, `enclosing_type' is equal to
129 `type', and `embedded_offset' is zero, so everything works
131 struct type
*enclosing_type
;
133 int pointed_to_offset
;
135 /* Values are stored in a chain, so that they can be deleted
136 easily over calls to the inferior. Values assigned to internal
137 variables or put into the value history are taken off this
141 /* Register number if the value is from a register. */
144 /* If zero, contents of this value are in the contents field. If
145 nonzero, contents are in inferior memory at address in the
146 location.address field plus the offset field (and the lval
147 field should be lval_memory).
149 WARNING: This field is used by the code which handles
150 watchpoints (see breakpoint.c) to decide whether a particular
151 value can be watched by hardware watchpoints. If the lazy flag
152 is set for some member of a value chain, it is assumed that
153 this member of the chain doesn't need to be watched as part of
154 watching the value itself. This is how GDB avoids watching the
155 entire struct or array when the user wants to watch a single
156 struct member or array element. If you ever change the way
157 lazy flag is set and reset, be sure to consider this use as
161 /* If nonzero, this is the value of a variable which does not
162 actually exist in the program. */
165 /* Actual contents of the value. For use of this value; setting
166 it uses the stuff above. Not valid if lazy is nonzero.
167 Target byte-order. We force it to be aligned properly for any
168 possible value. Note that a value therefore extends beyond
169 what is declared here. */
173 DOUBLEST force_doublest_align
;
174 LONGEST force_longest_align
;
175 CORE_ADDR force_core_addr_align
;
176 void *force_pointer_align
;
178 /* Do not add any new members here -- contents above will trash them. */
181 #define VALUE_TYPE(val) (val)->type
182 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
183 #define VALUE_LAZY(val) (val)->lazy
185 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
186 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_RAW is used when data is being stored into the
191 buffer, or when it is certain that the contents of the buffer are
194 Note: The contents pointer is adjusted by the offset required to
195 get to the real subobject, if the value happens to represent
196 something embedded in a larger run-time object. */
198 #define VALUE_CONTENTS_RAW(val) \
199 ((char *) (val)->aligner.contents + (val)->embedded_offset)
200 #define VALUE_CONTENTS(val) \
201 ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)), VALUE_CONTENTS_RAW(val))
203 /* The ALL variants of the above two macros do not adjust the returned
204 pointer by the embedded_offset value. */
206 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
207 #define VALUE_CONTENTS_ALL(val) \
208 ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)), \
209 VALUE_CONTENTS_ALL_RAW(val))
211 extern int value_fetch_lazy (struct value
*val
);
213 #define VALUE_LVAL(val) (val)->lval
214 #define VALUE_ADDRESS(val) (val)->location.address
215 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
216 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
217 #define VALUE_FRAME_ID(val) ((val)->frame_id)
218 #define VALUE_OFFSET(val) (val)->offset
219 #define VALUE_BITSIZE(val) (val)->bitsize
220 #define VALUE_BITPOS(val) (val)->bitpos
221 #define VALUE_NEXT(val) (val)->next
222 #define VALUE_REGNO(val) (val)->regno
223 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
224 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
225 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
227 /* Convert a REF to the object referenced. */
229 #define COERCE_REF(arg) \
231 struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg)); \
232 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \
233 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \
234 unpack_pointer (VALUE_TYPE (arg), \
235 VALUE_CONTENTS (arg))); \
238 /* If ARG is an array, convert it to a pointer.
239 If ARG is an enum, convert it to an integer.
240 If ARG is a function, convert it to a function pointer.
242 References are dereferenced. */
244 #define COERCE_ARRAY(arg) \
247 if (current_language->c_style_arrays \
248 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \
249 arg = value_coerce_array (arg); \
250 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \
251 arg = value_coerce_function (arg); \
254 #define COERCE_NUMBER(arg) \
255 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0)
257 /* If ARG is an enum, convert it to an integer. */
259 #define COERCE_ENUM(arg) \
261 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \
262 arg = value_cast (builtin_type_unsigned_int, arg); \
265 /* Internal variables (variables for convenience of use of debugger)
266 are recorded as a chain of these structures. */
270 struct internalvar
*next
;
275 /* Pointer to member function. Depends on compiler implementation. */
277 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
278 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
279 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
283 #include "gdbtypes.h"
284 #include "expression.h"
289 extern void print_address_demangle (CORE_ADDR
, struct ui_file
*, int);
291 extern LONGEST
value_as_long (struct value
*val
);
292 extern DOUBLEST
value_as_double (struct value
*val
);
293 extern CORE_ADDR
value_as_address (struct value
*val
);
295 extern LONGEST
unpack_long (struct type
*type
, const char *valaddr
);
296 extern DOUBLEST
unpack_double (struct type
*type
, const char *valaddr
,
298 extern CORE_ADDR
unpack_pointer (struct type
*type
, const char *valaddr
);
299 extern LONGEST
unpack_field_as_long (struct type
*type
, const char *valaddr
,
302 extern struct value
*value_from_longest (struct type
*type
, LONGEST num
);
303 extern struct value
*value_from_pointer (struct type
*type
, CORE_ADDR addr
);
304 extern struct value
*value_from_double (struct type
*type
, DOUBLEST num
);
305 extern struct value
*value_from_string (char *string
);
307 extern struct value
*value_at (struct type
*type
, CORE_ADDR addr
);
308 extern struct value
*value_at_lazy (struct type
*type
, CORE_ADDR addr
);
310 extern struct value
*value_from_register (struct type
*type
, int regnum
,
311 struct frame_info
*frame
);
313 extern struct value
*value_of_variable (struct symbol
*var
, struct block
*b
);
315 extern struct value
*value_of_register (int regnum
,
316 struct frame_info
*frame
);
318 extern int symbol_read_needs_frame (struct symbol
*);
320 extern struct value
*read_var_value (struct symbol
*var
,
321 struct frame_info
*frame
);
323 extern struct value
*locate_var_value (struct symbol
*var
,
324 struct frame_info
*frame
);
326 extern struct value
*allocate_value (struct type
*type
);
328 extern struct value
*allocate_repeat_value (struct type
*type
, int count
);
330 extern struct value
*value_change_enclosing_type (struct value
*val
,
331 struct type
*new_type
);
333 extern struct value
*value_mark (void);
335 extern void value_free_to_mark (struct value
*mark
);
337 extern struct value
*value_string (char *ptr
, int len
);
338 extern struct value
*value_bitstring (char *ptr
, int len
);
340 extern struct value
*value_array (int lowbound
, int highbound
,
341 struct value
** elemvec
);
343 extern struct value
*value_concat (struct value
*arg1
, struct value
*arg2
);
345 extern struct value
*value_binop (struct value
*arg1
, struct value
*arg2
,
348 extern struct value
*value_add (struct value
*arg1
, struct value
*arg2
);
350 extern struct value
*value_sub (struct value
*arg1
, struct value
*arg2
);
352 extern struct value
*value_coerce_array (struct value
*arg1
);
354 extern struct value
*value_coerce_function (struct value
*arg1
);
356 extern struct value
*value_ind (struct value
*arg1
);
358 extern struct value
*value_addr (struct value
*arg1
);
360 extern struct value
*value_assign (struct value
*toval
, struct value
*fromval
);
362 extern struct value
*value_neg (struct value
*arg1
);
364 extern struct value
*value_complement (struct value
*arg1
);
366 extern struct value
*value_struct_elt (struct value
**argp
,
368 char *name
, int *static_memfuncp
,
371 extern struct value
*value_aggregate_elt (struct type
*curtype
,
375 extern struct value
*value_static_field (struct type
*type
, int fieldno
);
377 extern struct fn_field
*value_find_oload_method_list (struct value
**, char *,
379 struct type
**, int *);
381 extern int find_overload_match (struct type
**arg_types
, int nargs
,
382 char *name
, int method
, int lax
,
383 struct value
**objp
, struct symbol
*fsym
,
384 struct value
**valp
, struct symbol
**symp
,
387 extern struct value
*value_field (struct value
*arg1
, int fieldno
);
389 extern struct value
*value_primitive_field (struct value
*arg1
, int offset
,
391 struct type
*arg_type
);
394 extern struct type
*value_rtti_target_type (struct value
*, int *, int *,
397 extern struct value
*value_full_object (struct value
*, struct type
*, int,
400 extern struct value
*value_cast (struct type
*type
, struct value
*arg2
);
402 extern struct value
*value_zero (struct type
*type
, enum lval_type lv
);
404 extern struct value
*value_repeat (struct value
*arg1
, int count
);
406 extern struct value
*value_subscript (struct value
*array
, struct value
*idx
);
408 extern struct value
*register_value_being_returned (struct type
*valtype
,
409 struct regcache
*retbuf
);
411 extern struct value
*value_in (struct value
*element
, struct value
*set
);
413 extern int value_bit_index (struct type
*type
, char *addr
, int index
);
415 extern int using_struct_return (struct type
*value_type
, int gcc_p
);
417 extern struct value
*evaluate_expression (struct expression
*exp
);
419 extern struct value
*evaluate_type (struct expression
*exp
);
421 extern struct value
*evaluate_subexp_with_coercion (struct expression
*,
424 extern struct value
*parse_and_eval (char *exp
);
426 extern struct value
*parse_to_comma_and_eval (char **expp
);
428 extern struct type
*parse_and_eval_type (char *p
, int length
);
430 extern CORE_ADDR
parse_and_eval_address (char *exp
);
432 extern CORE_ADDR
parse_and_eval_address_1 (char **expptr
);
434 extern LONGEST
parse_and_eval_long (char *exp
);
436 extern struct value
*access_value_history (int num
);
438 extern struct value
*value_of_internalvar (struct internalvar
*var
);
440 extern void set_internalvar (struct internalvar
*var
, struct value
*val
);
442 extern void set_internalvar_component (struct internalvar
*var
,
444 int bitpos
, int bitsize
,
445 struct value
*newvalue
);
447 extern struct internalvar
*lookup_internalvar (char *name
);
449 extern int value_equal (struct value
*arg1
, struct value
*arg2
);
451 extern int value_less (struct value
*arg1
, struct value
*arg2
);
453 extern int value_logical_not (struct value
*arg1
);
457 extern struct value
*value_of_this (int complain
);
459 extern struct value
*value_x_binop (struct value
*arg1
, struct value
*arg2
,
461 enum exp_opcode otherop
,
464 extern struct value
*value_x_unop (struct value
*arg1
, enum exp_opcode op
,
467 extern struct value
*value_fn_field (struct value
** arg1p
, struct fn_field
*f
,
468 int j
, struct type
*type
, int offset
);
470 extern int binop_user_defined_p (enum exp_opcode op
, struct value
*arg1
,
473 extern int unop_user_defined_p (enum exp_opcode op
, struct value
*arg1
);
475 extern int destructor_name_p (const char *name
, const struct type
*type
);
477 #define value_free(val) xfree (val)
479 extern void free_all_values (void);
481 extern void release_value (struct value
*val
);
483 extern int record_latest_value (struct value
*val
);
485 extern void modify_field (char *addr
, LONGEST fieldval
, int bitpos
,
488 extern void type_print (struct type
* type
, char *varstring
,
489 struct ui_file
* stream
, int show
);
491 extern char *baseclass_addr (struct type
*type
, int index
, char *valaddr
,
492 struct value
**valuep
, int *errp
);
494 extern void print_longest (struct ui_file
* stream
, int format
,
495 int use_local
, LONGEST val
);
497 extern void print_floating (char *valaddr
, struct type
* type
,
498 struct ui_file
* stream
);
500 extern int value_print (struct value
*val
, struct ui_file
*stream
, int format
,
501 enum val_prettyprint pretty
);
503 extern void value_print_array_elements (struct value
*val
,
504 struct ui_file
*stream
, int format
,
505 enum val_prettyprint pretty
);
507 extern struct value
*value_release_to_mark (struct value
*mark
);
509 extern int val_print (struct type
* type
, char *valaddr
,
510 int embedded_offset
, CORE_ADDR address
,
511 struct ui_file
* stream
, int format
,
512 int deref_ref
, int recurse
,
513 enum val_prettyprint pretty
);
515 extern int val_print_string (CORE_ADDR addr
, int len
, int width
, struct ui_file
*stream
);
517 extern void print_variable_value (struct symbol
* var
,
518 struct frame_info
* frame
,
519 struct ui_file
*stream
);
521 extern int check_field (struct value
*, const char *);
523 extern void typedef_print (struct type
* type
, struct symbol
* news
,
524 struct ui_file
* stream
);
526 extern char *internalvar_name (struct internalvar
*var
);
528 extern void clear_value_history (void);
530 extern void clear_internalvars (void);
534 extern struct value
*value_copy (struct value
*);
538 extern struct value
*varying_to_slice (struct value
*);
540 extern struct value
*value_slice (struct value
*, int, int);
542 extern struct value
*value_literal_complex (struct value
*, struct value
*,
545 extern void find_rt_vbase_offset (struct type
*, struct type
*, char *, int,
548 extern struct value
*find_function_in_inferior (const char *);
550 extern struct value
*value_allocate_space_in_inferior (int);
552 extern struct value
*value_of_local (const char *name
, int complain
);
554 #endif /* !defined (VALUE_H) */