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 /* The BFD section associated with this value. */
166 asection *bfd_section;
168 /* If value is a variable, is it initialized or not. */
171 /* Actual contents of the value. For use of this value; setting
172 it uses the stuff above. Not valid if lazy is nonzero.
173 Target byte-order. We force it to be aligned properly for any
174 possible value. Note that a value therefore extends beyond
175 what is declared here. */
179 DOUBLEST force_doublest_align;
180 LONGEST force_longest_align;
181 CORE_ADDR force_core_addr_align;
182 void *force_pointer_align;
184 /* Do not add any new members here -- contents above will trash them. */
187 #define VALUE_TYPE(val) (val)->type
188 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
189 #define VALUE_LAZY(val) (val)->lazy
191 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
192 the gdb buffer used to hold a copy of the contents of the lval.
193 VALUE_CONTENTS is used when the contents of the buffer are needed
194 -- it uses value_fetch_lazy() to load the buffer from the process
195 being debugged if it hasn't already been loaded.
196 VALUE_CONTENTS_RAW is used when data is being stored into the
197 buffer, or when it is certain that the contents of the buffer are
200 Note: The contents pointer is adjusted by the offset required to
201 get to the real subobject, if the value happens to represent
202 something embedded in a larger run-time object. */
204 #define VALUE_CONTENTS_RAW(val) \
205 ((char *) (val)->aligner.contents + (val)->embedded_offset)
206 #define VALUE_CONTENTS(val) \
207 ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)), VALUE_CONTENTS_RAW(val))
209 /* The ALL variants of the above two macros do not adjust the returned
210 pointer by the embedded_offset value. */
212 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
213 #define VALUE_CONTENTS_ALL(val) \
214 ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)), \
215 VALUE_CONTENTS_ALL_RAW(val))
217 extern int value_fetch_lazy (struct value *val);
219 #define VALUE_LVAL(val) (val)->lval
220 #define VALUE_ADDRESS(val) (val)->location.address
221 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
222 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
223 #define VALUE_FRAME_ID(val) ((val)->frame_id)
224 #define VALUE_OFFSET(val) (val)->offset
225 #define VALUE_BITSIZE(val) (val)->bitsize
226 #define VALUE_BITPOS(val) (val)->bitpos
227 #define VALUE_NEXT(val) (val)->next
228 #define VALUE_REGNO(val) (val)->regno
229 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
230 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
231 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
232 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
234 /* Convert a REF to the object referenced. */
236 #define COERCE_REF(arg) \
238 struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg)); \
239 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \
240 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \
241 unpack_pointer (VALUE_TYPE (arg), \
242 VALUE_CONTENTS (arg)), \
243 VALUE_BFD_SECTION (arg)); \
246 /* If ARG is an array, convert it to a pointer.
247 If ARG is an enum, convert it to an integer.
248 If ARG is a function, convert it to a function pointer.
250 References are dereferenced. */
252 #define COERCE_ARRAY(arg) \
255 if (current_language->c_style_arrays \
256 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \
257 arg = value_coerce_array (arg); \
258 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \
259 arg = value_coerce_function (arg); \
262 #define COERCE_NUMBER(arg) \
263 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0)
265 /* NOTE: cagney/2002-12-17: This macro was handling a chill language
266 problem but that language has gone away. */
267 #define COERCE_VARYING_ARRAY(arg, real_arg_type)
269 /* If ARG is an enum, convert it to an integer. */
271 #define COERCE_ENUM(arg) \
273 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \
274 arg = value_cast (builtin_type_unsigned_int, arg); \
277 /* Internal variables (variables for convenience of use of debugger)
278 are recorded as a chain of these structures. */
282 struct internalvar *next;
287 /* Pointer to member function. Depends on compiler implementation. */
289 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
290 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
291 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
295 #include "gdbtypes.h"
296 #include "expression.h"
301 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
303 extern LONGEST value_as_long (struct value *val);
304 extern DOUBLEST value_as_double (struct value *val);
305 extern CORE_ADDR value_as_address (struct value *val);
307 extern LONGEST unpack_long (struct type *type, const char *valaddr);
308 extern DOUBLEST unpack_double (struct type *type, const char *valaddr,
310 extern CORE_ADDR unpack_pointer (struct type *type, const char *valaddr);
311 extern LONGEST unpack_field_as_long (struct type *type, const char *valaddr,
314 extern struct value *value_from_longest (struct type *type, LONGEST num);
315 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
316 extern struct value *value_from_double (struct type *type, DOUBLEST num);
317 extern struct value *value_from_string (char *string);
319 extern struct value *value_at (struct type *type, CORE_ADDR addr,
321 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr,
324 extern struct value *value_from_register (struct type *type, int regnum,
325 struct frame_info *frame);
327 extern struct value *value_of_variable (struct symbol *var, struct block *b);
329 extern struct value *value_of_register (int regnum,
330 struct frame_info *frame);
332 extern int symbol_read_needs_frame (struct symbol *);
334 extern struct value *read_var_value (struct symbol *var,
335 struct frame_info *frame);
337 extern struct value *locate_var_value (struct symbol *var,
338 struct frame_info *frame);
340 extern struct value *allocate_value (struct type *type);
342 extern struct value *allocate_repeat_value (struct type *type, int count);
344 extern struct value *value_change_enclosing_type (struct value *val,
345 struct type *new_type);
347 extern struct value *value_mark (void);
349 extern void value_free_to_mark (struct value *mark);
351 extern struct value *value_string (char *ptr, int len);
352 extern struct value *value_bitstring (char *ptr, int len);
354 extern struct value *value_array (int lowbound, int highbound,
355 struct value ** elemvec);
357 extern struct value *value_concat (struct value *arg1, struct value *arg2);
359 extern struct value *value_binop (struct value *arg1, struct value *arg2,
362 extern struct value *value_add (struct value *arg1, struct value *arg2);
364 extern struct value *value_sub (struct value *arg1, struct value *arg2);
366 extern struct value *value_coerce_array (struct value *arg1);
368 extern struct value *value_coerce_function (struct value *arg1);
370 extern struct value *value_ind (struct value *arg1);
372 extern struct value *value_addr (struct value *arg1);
374 extern struct value *value_assign (struct value *toval, struct value *fromval);
376 extern struct value *value_neg (struct value *arg1);
378 extern struct value *value_complement (struct value *arg1);
380 extern struct value *value_struct_elt (struct value **argp,
382 char *name, int *static_memfuncp,
385 extern struct value *value_aggregate_elt (struct type *curtype,
389 extern struct value *value_static_field (struct type *type, int fieldno);
391 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
393 struct type **, int *);
395 extern int find_overload_match (struct type **arg_types, int nargs,
396 char *name, int method, int lax,
397 struct value **objp, struct symbol *fsym,
398 struct value **valp, struct symbol **symp,
401 extern struct value *value_field (struct value *arg1, int fieldno);
403 extern struct value *value_primitive_field (struct value *arg1, int offset,
405 struct type *arg_type);
408 extern struct type *value_rtti_target_type (struct value *, int *, int *,
411 extern struct value *value_full_object (struct value *, struct type *, int,
414 extern struct value *value_cast (struct type *type, struct value *arg2);
416 extern struct value *value_zero (struct type *type, enum lval_type lv);
418 extern struct value *value_repeat (struct value *arg1, int count);
420 extern struct value *value_subscript (struct value *array, struct value *idx);
422 extern struct value *register_value_being_returned (struct type *valtype,
423 struct regcache *retbuf);
425 extern struct value *value_in (struct value *element, struct value *set);
427 extern int value_bit_index (struct type *type, char *addr, int index);
429 extern int using_struct_return (struct type *value_type, int gcc_p);
431 extern struct value *evaluate_expression (struct expression *exp);
433 extern struct value *evaluate_type (struct expression *exp);
435 extern struct value *evaluate_subexp_with_coercion (struct expression *,
438 extern struct value *parse_and_eval (char *exp);
440 extern struct value *parse_to_comma_and_eval (char **expp);
442 extern struct type *parse_and_eval_type (char *p, int length);
444 extern CORE_ADDR parse_and_eval_address (char *exp);
446 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
448 extern LONGEST parse_and_eval_long (char *exp);
450 extern struct value *access_value_history (int num);
452 extern struct value *value_of_internalvar (struct internalvar *var);
454 extern void set_internalvar (struct internalvar *var, struct value *val);
456 extern void set_internalvar_component (struct internalvar *var,
458 int bitpos, int bitsize,
459 struct value *newvalue);
461 extern struct internalvar *lookup_internalvar (char *name);
463 extern int value_equal (struct value *arg1, struct value *arg2);
465 extern int value_less (struct value *arg1, struct value *arg2);
467 extern int value_logical_not (struct value *arg1);
471 extern struct value *value_of_this (int complain);
473 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
475 enum exp_opcode otherop,
478 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
481 extern struct value *value_fn_field (struct value ** arg1p, struct fn_field *f,
482 int j, struct type *type, int offset);
484 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
487 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
489 extern int destructor_name_p (const char *name, const struct type *type);
491 #define value_free(val) xfree (val)
493 extern void free_all_values (void);
495 extern void release_value (struct value *val);
497 extern int record_latest_value (struct value *val);
499 extern void modify_field (char *addr, LONGEST fieldval, int bitpos,
502 extern void type_print (struct type * type, char *varstring,
503 struct ui_file * stream, int show);
505 extern char *baseclass_addr (struct type *type, int index, char *valaddr,
506 struct value **valuep, int *errp);
508 extern void print_longest (struct ui_file * stream, int format,
509 int use_local, LONGEST val);
511 extern void print_floating (char *valaddr, struct type * type,
512 struct ui_file * stream);
514 extern int value_print (struct value *val, struct ui_file *stream, int format,
515 enum val_prettyprint pretty);
517 extern void value_print_array_elements (struct value *val,
518 struct ui_file *stream, int format,
519 enum val_prettyprint pretty);
521 extern struct value *value_release_to_mark (struct value *mark);
523 extern int val_print (struct type * type, char *valaddr,
524 int embedded_offset, CORE_ADDR address,
525 struct ui_file * stream, int format,
526 int deref_ref, int recurse,
527 enum val_prettyprint pretty);
529 extern int common_val_print (struct value *val,
530 struct ui_file *stream, int format,
531 int deref_ref, int recurse,
532 enum val_prettyprint pretty);
534 extern int val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream);
536 extern void print_variable_value (struct symbol * var,
537 struct frame_info * frame,
538 struct ui_file *stream);
540 extern int check_field (struct value *, const char *);
542 extern void typedef_print (struct type * type, struct symbol * news,
543 struct ui_file * stream);
545 extern char *internalvar_name (struct internalvar *var);
547 extern void clear_value_history (void);
549 extern void clear_internalvars (void);
553 extern struct value *value_copy (struct value *);
557 extern struct value *varying_to_slice (struct value *);
559 extern struct value *value_slice (struct value *, int, int);
561 extern struct value *value_literal_complex (struct value *, struct value *,
564 extern void find_rt_vbase_offset (struct type *, struct type *, char *, int,
567 extern struct value *find_function_in_inferior (const char *);
569 extern struct value *value_allocate_space_in_inferior (int);
571 extern CORE_ADDR legacy_push_arguments (int nargs, struct value ** args,
572 CORE_ADDR sp, int struct_return,
573 CORE_ADDR struct_addr);
575 extern struct value *value_of_local (const char *name, int complain);
577 #endif /* !defined (VALUE_H) */