1 /* Definitions for values of C expressions, for GDB.
2 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
3 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 #if !defined (VALUE_H)
32 * The structure which defines the type of a value. It should never
33 * be possible for a program lval value to survive over a call to the inferior
34 * (ie to be put into the history list or an internal variable).
39 /* Type of value; either not an lval, or one of the various
40 different possible kinds of lval. */
42 /* Is it modifiable? Only relevant if lval != not_lval. */
44 /* Location of value (if lval). */
47 /* If lval == lval_memory, this is the address in the inferior.
48 If lval == lval_register, this is the byte offset into the
49 registers structure. */
51 /* Pointer to internal variable. */
52 struct internalvar *internalvar;
53 /* Number of register. Only used with
54 lval_reg_frame_relative. */
58 /* Describes offset of a value within lval of a structure in bytes.
59 If lval == lval_memory, this is an offset to the address.
60 If lval == lval_register, this is a further offset from
61 location.address within the registers structure.
62 Note also the member embedded_offset below. */
64 /* Only used for bitfields; number of bits contained in them. */
66 /* Only used for bitfields; position of start of field.
67 For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
68 For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
70 /* Frame value is relative to. In practice, this address is only
71 used if the value is stored in several registers in other than
72 the current frame, and these registers have not all been saved
73 at the same place in memory. This will be described in the
74 lval enum above as "lval_reg_frame_relative". */
77 /* Type of the value. */
80 /* If a value represents a C++ object, then the `type' field gives
81 the object's compile-time type. If the object actually belongs
82 to some class derived from `type', perhaps with other base
83 classes and additional members, then `type' is just a subobject
84 of the real thing, and the full object is probably larger than
87 If `type' is a dynamic class (i.e. one with a vtable), then GDB
88 can actually determine the object's run-time type by looking at
89 the run-time type information in the vtable. When this
90 information is available, we may elect to read in the entire
91 object, for several reasons:
93 - When printing the value, the user would probably rather see
94 the full object, not just the limited portion apparent from
95 the compile-time type.
97 - If `type' has virtual base classes, then even printing
98 `type' alone may require reaching outside the `type'
99 portion of the object to wherever the virtual base class
102 When we store the entire object, `enclosing_type' is the
103 run-time type --- the complete object --- and `embedded_offset'
104 is the offset of `type' within that larger type, in bytes. The
105 VALUE_CONTENTS macro takes `embedded_offset' into account, so
106 most GDB code continues to see the `type' portion of the value,
107 just as the inferior would.
109 If `type' is a pointer to an object, then `enclosing_type' is a
110 pointer to the object's run-time type, and `pointed_to_offset'
111 is the offset in bytes from the full object to the pointed-to
112 object --- that is, the value `embedded_offset' would have if
113 we followed the pointer and fetched the complete object. (I
114 don't really see the point. Why not just determine the
115 run-time type when you indirect, and avoid the special case?
116 The contents don't matter until you indirect anyway.)
118 If we're not doing anything fancy, `enclosing_type' is equal to
119 `type', and `embedded_offset' is zero, so everything works
121 struct type *enclosing_type;
123 int pointed_to_offset;
125 /* Values are stored in a chain, so that they can be deleted
126 easily over calls to the inferior. Values assigned to internal
127 variables or put into the value history are taken off this
131 /* Register number if the value is from a register. */
133 /* If zero, contents of this value are in the contents field.
134 If nonzero, contents are in inferior memory at address
135 in the location.address field plus the offset field
136 (and the lval field should be lval_memory).
138 WARNING: This field is used by the code which handles
139 watchpoints (see breakpoint.c) to decide whether a particular
140 value can be watched by hardware watchpoints. If the lazy flag
141 is set for some member of a value chain, it is assumed that
142 this member of the chain doesn't need to be watched as part of
143 watching the value itself. This is how GDB avoids watching the
144 entire struct or array when the user wants to watch a single
145 struct member or array element. If you ever change the way
146 lazy flag is set and reset, be sure to consider this use as
149 /* If nonzero, this is the value of a variable which does not
150 actually exist in the program. */
152 /* The BFD section associated with this value. */
153 asection *bfd_section;
154 /* Actual contents of the value. For use of this value; setting
155 it uses the stuff above. Not valid if lazy is nonzero.
156 Target byte-order. We force it to be aligned properly for any
157 possible value. Note that a value therefore extends beyond
158 what is declared here. */
162 DOUBLEST force_doublest_align;
163 LONGEST force_longest_align;
164 CORE_ADDR force_core_addr_align;
165 void *force_pointer_align;
168 /* Do not add any new members here -- contents above will trash them */
171 #define VALUE_TYPE(val) (val)->type
172 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
173 #define VALUE_LAZY(val) (val)->lazy
174 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
175 the gdb buffer used to hold a copy of the contents of the lval.
176 VALUE_CONTENTS is used when the contents of the buffer are needed --
177 it uses value_fetch_lazy() to load the buffer from the process being
178 debugged if it hasn't already been loaded. VALUE_CONTENTS_RAW is
179 used when data is being stored into the buffer, or when it is
180 certain that the contents of the buffer are valid.
181 Note: The contents pointer is adjusted by the offset required to
182 get to the real subobject, if the value happens to represent
183 something embedded in a larger run-time object. */
185 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
186 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
187 VALUE_CONTENTS_RAW(val))
189 /* The ALL variants of the above two macros do not adjust the returned
190 pointer by the embedded_offset value. */
192 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
193 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
194 VALUE_CONTENTS_ALL_RAW(val))
197 extern int value_fetch_lazy (struct value *val);
199 #define VALUE_LVAL(val) (val)->lval
200 #define VALUE_ADDRESS(val) (val)->location.address
201 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
202 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
203 #define VALUE_FRAME(val) ((val)->frame_addr)
204 #define VALUE_OFFSET(val) (val)->offset
205 #define VALUE_BITSIZE(val) (val)->bitsize
206 #define VALUE_BITPOS(val) (val)->bitpos
207 #define VALUE_NEXT(val) (val)->next
208 #define VALUE_REGNO(val) (val)->regno
209 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
210 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
211 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
212 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
214 /* Convert a REF to the object referenced. */
216 #define COERCE_REF(arg) \
217 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
218 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \
219 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \
220 unpack_pointer (VALUE_TYPE (arg), \
221 VALUE_CONTENTS (arg)), \
222 VALUE_BFD_SECTION (arg)); \
225 /* If ARG is an array, convert it to a pointer.
226 If ARG is an enum, convert it to an integer.
227 If ARG is a function, convert it to a function pointer.
229 References are dereferenced. */
231 #define COERCE_ARRAY(arg) \
232 do { COERCE_REF(arg); \
233 if (current_language->c_style_arrays \
234 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \
235 arg = value_coerce_array (arg); \
236 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \
237 arg = value_coerce_function (arg); \
240 #define COERCE_NUMBER(arg) \
241 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0)
243 /* NOTE: cagney/2002-12-17: This macro was handling a chill language
244 problem but that language has gone away. */
245 #define COERCE_VARYING_ARRAY(arg, real_arg_type)
247 /* If ARG is an enum, convert it to an integer. */
249 #define COERCE_ENUM(arg) { \
250 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \
251 arg = value_cast (builtin_type_unsigned_int, arg); \
254 /* Internal variables (variables for convenience of use of debugger)
255 are recorded as a chain of these structures. */
259 struct internalvar *next;
264 /* Pointer to member function. Depends on compiler implementation. */
266 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
267 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
268 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
272 #include "gdbtypes.h"
273 #include "expression.h"
278 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
280 extern LONGEST value_as_long (struct value *val);
282 extern DOUBLEST value_as_double (struct value *val);
284 extern CORE_ADDR value_as_address (struct value *val);
286 extern LONGEST unpack_long (struct type *type, const char *valaddr);
288 extern DOUBLEST unpack_double (struct type *type, const char *valaddr,
291 extern CORE_ADDR unpack_pointer (struct type *type, const char *valaddr);
293 extern LONGEST unpack_field_as_long (struct type *type, const char *valaddr,
296 extern struct value *value_from_longest (struct type *type, LONGEST num);
298 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
300 extern struct value *value_from_double (struct type *type, DOUBLEST num);
302 extern struct value *value_from_string (char *string);
304 extern struct value *value_at (struct type *type, CORE_ADDR addr,
307 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_struct_elt_for_reference (struct type *domain,
373 struct type *curtype,
375 struct type *intype);
377 extern struct value *value_static_field (struct type *type, int fieldno);
379 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
381 struct type **, int *);
383 extern int find_overload_match (struct type **arg_types, int nargs,
384 char *name, int method, int lax,
385 struct value **objp, struct symbol *fsym,
386 struct value **valp, struct symbol **symp,
389 extern struct value *value_field (struct value *arg1, int fieldno);
391 extern struct value *value_primitive_field (struct value *arg1, int offset,
393 struct type *arg_type);
396 extern struct type *value_rtti_target_type (struct value *, int *, int *,
399 extern struct value *value_full_object (struct value *, struct type *, int,
402 extern struct value *value_cast (struct type *type, struct value *arg2);
404 extern struct value *value_zero (struct type *type, enum lval_type lv);
406 extern struct value *value_repeat (struct value *arg1, int count);
408 extern struct value *value_subscript (struct value *array, struct value *idx);
410 extern struct value *value_being_returned (struct type *valtype,
411 struct regcache *retbuf,
414 extern struct value *value_in (struct value *element, struct value *set);
416 extern int value_bit_index (struct type *type, char *addr, int index);
418 extern int using_struct_return (struct value *function, CORE_ADDR funcaddr,
419 struct type *value_type, int gcc_p);
421 extern void set_return_value (struct value *val);
423 extern struct value *evaluate_expression (struct expression *exp);
425 extern struct value *evaluate_type (struct expression *exp);
427 extern struct value *evaluate_subexp_with_coercion (struct expression *,
430 extern struct value *parse_and_eval (char *exp);
432 extern struct value *parse_to_comma_and_eval (char **expp);
434 extern struct type *parse_and_eval_type (char *p, int length);
436 extern CORE_ADDR parse_and_eval_address (char *exp);
438 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
440 extern LONGEST parse_and_eval_long (char *exp);
442 extern struct value *access_value_history (int num);
444 extern struct value *value_of_internalvar (struct internalvar *var);
446 extern void set_internalvar (struct internalvar *var, struct value *val);
448 extern void set_internalvar_component (struct internalvar *var,
450 int bitpos, int bitsize,
451 struct value *newvalue);
453 extern struct internalvar *lookup_internalvar (char *name);
455 extern int value_equal (struct value *arg1, struct value *arg2);
457 extern int value_less (struct value *arg1, struct value *arg2);
459 extern int value_logical_not (struct value *arg1);
463 extern struct value *value_of_this (int complain);
465 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
467 enum exp_opcode otherop,
470 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
473 extern struct value *value_fn_field (struct value ** arg1p, struct fn_field *f,
474 int j, struct type *type, int offset);
476 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
479 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
481 extern int destructor_name_p (const char *name, const struct type *type);
483 #define value_free(val) xfree (val)
485 extern void free_all_values (void);
487 extern void release_value (struct value *val);
489 extern int record_latest_value (struct value *val);
491 extern void modify_field (char *addr, LONGEST fieldval, int bitpos,
494 extern void type_print (struct type * type, char *varstring,
495 struct ui_file * stream, int show);
497 extern char *baseclass_addr (struct type *type, int index, char *valaddr,
498 struct value **valuep, int *errp);
500 extern void print_longest (struct ui_file * stream, int format,
501 int use_local, LONGEST val);
503 extern void print_floating (char *valaddr, struct type * type,
504 struct ui_file * stream);
506 extern int value_print (struct value *val, struct ui_file *stream, int format,
507 enum val_prettyprint pretty);
509 extern void value_print_array_elements (struct value *val,
510 struct ui_file *stream, int format,
511 enum val_prettyprint pretty);
513 extern struct value *value_release_to_mark (struct value *mark);
515 extern int val_print (struct type * type, char *valaddr,
516 int embedded_offset, CORE_ADDR address,
517 struct ui_file * stream, int format,
518 int deref_ref, int recurse,
519 enum val_prettyprint pretty);
521 extern int val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream);
523 extern void print_variable_value (struct symbol * var,
524 struct frame_info * frame,
525 struct ui_file *stream);
527 extern int check_field (struct value *, const char *);
529 extern void typedef_print (struct type * type, struct symbol * news,
530 struct ui_file * stream);
532 extern char *internalvar_name (struct internalvar *var);
534 extern void clear_value_history (void);
536 extern void clear_internalvars (void);
540 extern struct value *value_copy (struct value *);
544 extern struct value *varying_to_slice (struct value *);
546 extern struct value *value_slice (struct value *, int, int);
548 extern struct value *call_function_by_hand (struct value *, int,
551 extern struct value *value_literal_complex (struct value *, struct value *,
554 extern void find_rt_vbase_offset (struct type *, struct type *, char *, int,
557 extern struct value *find_function_in_inferior (const char *);
559 extern struct value *value_allocate_space_in_inferior (int);
561 extern CORE_ADDR legacy_push_arguments (int nargs, struct value ** args,
562 CORE_ADDR sp, int struct_return,
563 CORE_ADDR struct_addr);
565 extern struct value *value_of_local (const char *name, int complain);
567 #endif /* !defined (VALUE_H) */