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
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)
29 * The structure which defines the type of a value. It should never
30 * be possible for a program lval value to survive over a call to the inferior
31 * (ie to be put into the history list or an internal variable).
36 /* Type of value; either not an lval, or one of the various
37 different possible kinds of lval. */
39 /* Is it modifiable? Only relevant if lval != not_lval. */
41 /* Location of value (if lval). */
44 /* If lval == lval_memory, this is the address in the inferior.
45 If lval == lval_register, this is the byte offset into the
46 registers structure. */
48 /* Pointer to internal variable. */
49 struct internalvar *internalvar;
50 /* Number of register. Only used with
51 lval_reg_frame_relative. */
55 /* Describes offset of a value within lval of a structure in bytes.
56 If lval == lval_memory, this is an offset to the address.
57 If lval == lval_register, this is a further offset from
58 location.address within the registers structure.
59 Note also the member embedded_offset below. */
61 /* Only used for bitfields; number of bits contained in them. */
63 /* Only used for bitfields; position of start of field.
64 For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
65 For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
67 /* Frame value is relative to. In practice, this address is only
68 used if the value is stored in several registers in other than
69 the current frame, and these registers have not all been saved
70 at the same place in memory. This will be described in the
71 lval enum above as "lval_reg_frame_relative". */
74 /* Type of the value. */
77 /* If a value represents a C++ object, then the `type' field gives
78 the object's compile-time type. If the object actually belongs
79 to some class derived from `type', perhaps with other base
80 classes and additional members, then `type' is just a subobject
81 of the real thing, and the full object is probably larger than
84 If `type' is a dynamic class (i.e. one with a vtable), then GDB
85 can actually determine the object's run-time type by looking at
86 the run-time type information in the vtable. When this
87 information is available, we may elect to read in the entire
88 object, for several reasons:
90 - When printing the value, the user would probably rather see
91 the full object, not just the limited portion apparent from
92 the compile-time type.
94 - If `type' has virtual base classes, then even printing
95 `type' alone may require reaching outside the `type'
96 portion of the object to wherever the virtual base class
99 When we store the entire object, `enclosing_type' is the
100 run-time type --- the complete object --- and `embedded_offset'
101 is the offset of `type' within that larger type, in bytes. The
102 VALUE_CONTENTS macro takes `embedded_offset' into account, so
103 most GDB code continues to see the `type' portion of the value,
104 just as the inferior would.
106 If `type' is a pointer to an object, then `enclosing_type' is a
107 pointer to the object's run-time type, and `pointed_to_offset'
108 is the offset in bytes from the full object to the pointed-to
109 object --- that is, the value `embedded_offset' would have if
110 we followed the pointer and fetched the complete object. (I
111 don't really see the point. Why not just determine the
112 run-time type when you indirect, and avoid the special case?
113 The contents don't matter until you indirect anyway.)
115 If we're not doing anything fancy, `enclosing_type' is equal to
116 `type', and `embedded_offset' is zero, so everything works
118 struct type *enclosing_type;
120 int pointed_to_offset;
122 /* Values are stored in a chain, so that they can be deleted
123 easily over calls to the inferior. Values assigned to internal
124 variables or put into the value history are taken off this
128 /* ??? When is this used? */
136 /* Register number if the value is from a register. Is not kept
137 if you take a field of a structure that is stored in a
138 register. Shouldn't it be? */
140 /* If zero, contents of this value are in the contents field.
141 If nonzero, contents are in inferior memory at address
142 in the location.address field plus the offset field
143 (and the lval field should be lval_memory).
145 WARNING: This field is used by the code which handles
146 watchpoints (see breakpoint.c) to decide whether a particular
147 value can be watched by hardware watchpoints. If the lazy flag
148 is set for some member of a value chain, it is assumed that
149 this member of the chain doesn't need to be watched as part of
150 watching the value itself. This is how GDB avoids watching the
151 entire struct or array when the user wants to watch a single
152 struct member or array element. If you ever change the way
153 lazy flag is set and reset, be sure to consider this use as
156 /* If nonzero, this is the value of a variable which does not
157 actually exist in the program. */
159 /* The BFD section associated with this value. */
160 asection *bfd_section;
161 /* Actual contents of the value. For use of this value; setting
162 it uses the stuff above. Not valid if lazy is nonzero.
163 Target byte-order. We force it to be aligned properly for any
164 possible value. Note that a value therefore extends beyond
165 what is declared here. */
169 double force_double_align;
170 LONGEST force_longlong_align;
174 /* Do not add any new members here -- contents above will trash them */
177 #define VALUE_TYPE(val) (val)->type
178 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
179 #define VALUE_LAZY(val) (val)->lazy
180 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
181 the gdb buffer used to hold a copy of the contents of the lval.
182 VALUE_CONTENTS is used when the contents of the buffer are needed --
183 it uses value_fetch_lazy() to load the buffer from the process being
184 debugged if it hasn't already been loaded. VALUE_CONTENTS_RAW is
185 used when data is being stored into the buffer, or when it is
186 certain that the contents of the buffer are valid.
187 Note: The contents pointer is adjusted by the offset required to
188 get to the real subobject, if the value happens to represent
189 something embedded in a larger run-time object. */
191 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
192 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
193 VALUE_CONTENTS_RAW(val))
195 /* The ALL variants of the above two macros do not adjust the returned
196 pointer by the embedded_offset value. */
198 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
199 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
200 VALUE_CONTENTS_ALL_RAW(val))
203 extern int value_fetch_lazy (struct value *val);
205 #define VALUE_LVAL(val) (val)->lval
206 #define VALUE_ADDRESS(val) (val)->location.address
207 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
208 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
209 #define VALUE_FRAME(val) ((val)->frame_addr)
210 #define VALUE_OFFSET(val) (val)->offset
211 #define VALUE_BITSIZE(val) (val)->bitsize
212 #define VALUE_BITPOS(val) (val)->bitpos
213 #define VALUE_NEXT(val) (val)->next
214 #define VALUE_REGNO(val) (val)->regno
215 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
216 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
217 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
218 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
220 /* Convert a REF to the object referenced. */
222 #define COERCE_REF(arg) \
223 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
224 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \
225 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \
226 unpack_pointer (VALUE_TYPE (arg), \
227 VALUE_CONTENTS (arg)), \
228 VALUE_BFD_SECTION (arg)); \
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.
235 References are dereferenced. */
237 #define COERCE_ARRAY(arg) \
238 do { COERCE_REF(arg); \
239 if (current_language->c_style_arrays \
240 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \
241 arg = value_coerce_array (arg); \
242 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \
243 arg = value_coerce_function (arg); \
246 #define COERCE_NUMBER(arg) \
247 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0)
249 #define COERCE_VARYING_ARRAY(arg, real_arg_type) \
250 { if (chill_varying_type (real_arg_type)) \
251 arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }
253 /* If ARG is an enum, convert it to an integer. */
255 #define COERCE_ENUM(arg) { \
256 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \
257 arg = value_cast (builtin_type_unsigned_int, arg); \
260 /* Internal variables (variables for convenience of use of debugger)
261 are recorded as a chain of these structures. */
265 struct internalvar *next;
270 /* Pointer to member function. Depends on compiler implementation. */
272 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
273 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
274 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
278 #include "gdbtypes.h"
279 #include "expression.h"
284 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
286 extern LONGEST value_as_long (struct value *val);
288 extern DOUBLEST value_as_double (struct value *val);
290 extern CORE_ADDR value_as_address (struct value *val);
292 extern LONGEST unpack_long (struct type *type, char *valaddr);
294 extern DOUBLEST unpack_double (struct type *type, char *valaddr, int *invp);
296 extern CORE_ADDR unpack_pointer (struct type *type, char *valaddr);
298 extern LONGEST unpack_field_as_long (struct type *type, char *valaddr,
301 extern struct value *value_from_longest (struct type *type, LONGEST num);
303 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
305 extern struct value *value_from_double (struct type *type, DOUBLEST num);
307 extern struct value *value_from_string (char *string);
309 extern struct value *value_at (struct type *type, CORE_ADDR addr,
312 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr,
315 extern struct value *value_from_register (struct type *type, int regnum,
316 struct frame_info *frame);
318 extern struct value *value_of_variable (struct symbol *var, struct block *b);
320 extern struct value *value_of_register (int regnum,
321 struct frame_info *frame);
323 extern int symbol_read_needs_frame (struct symbol *);
325 extern struct value *read_var_value (struct symbol *var,
326 struct frame_info *frame);
328 extern struct value *locate_var_value (struct symbol *var,
329 struct frame_info *frame);
331 extern struct value *allocate_value (struct type *type);
333 extern struct value *allocate_repeat_value (struct type *type, int count);
335 extern struct value *value_change_enclosing_type (struct value *val,
336 struct type *new_type);
338 extern struct value *value_mark (void);
340 extern void value_free_to_mark (struct value *mark);
342 extern struct value *value_string (char *ptr, int len);
343 extern struct value *value_bitstring (char *ptr, int len);
345 extern struct value *value_array (int lowbound, int highbound,
346 struct value ** elemvec);
348 extern struct value *value_concat (struct value *arg1, struct value *arg2);
350 extern struct value *value_binop (struct value *arg1, struct value *arg2,
353 extern struct value *value_add (struct value *arg1, struct value *arg2);
355 extern struct value *value_sub (struct value *arg1, struct value *arg2);
357 extern struct value *value_coerce_array (struct value *arg1);
359 extern struct value *value_coerce_function (struct value *arg1);
361 extern struct value *value_ind (struct value *arg1);
363 extern struct value *value_addr (struct value *arg1);
365 extern struct value *value_assign (struct value *toval, struct value *fromval);
367 extern struct value *value_neg (struct value *arg1);
369 extern struct value *value_complement (struct value *arg1);
371 extern struct value *value_struct_elt (struct value **argp,
373 char *name, int *static_memfuncp,
376 extern struct value *value_struct_elt_for_reference (struct type *domain,
378 struct type *curtype,
380 struct type *intype);
382 extern struct value *value_static_field (struct type *type, int fieldno);
384 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
386 struct type **, int *);
388 extern int find_overload_match (struct type **arg_types, int nargs,
389 char *name, int method, int lax,
390 struct value **objp, struct symbol *fsym,
391 struct value **valp, struct symbol **symp,
394 extern struct value *value_field (struct value *arg1, int fieldno);
396 extern struct value *value_primitive_field (struct value *arg1, int offset,
398 struct type *arg_type);
401 extern struct type *value_rtti_target_type (struct value *, int *, int *,
404 extern struct value *value_full_object (struct value *, struct type *, int,
407 extern struct value *value_cast (struct type *type, struct value *arg2);
409 extern struct value *value_zero (struct type *type, enum lval_type lv);
411 extern struct value *value_repeat (struct value *arg1, int count);
413 extern struct value *value_subscript (struct value *array, struct value *idx);
415 extern struct value *value_from_vtable_info (struct value *arg,
418 extern struct value *value_being_returned (struct type *valtype,
419 char *retbuf, int struct_return);
421 extern struct value *value_in (struct value *element, struct value *set);
423 extern int value_bit_index (struct type *type, char *addr, int index);
425 extern int using_struct_return (struct value *function, CORE_ADDR funcaddr,
426 struct type *value_type, int gcc_p);
428 extern void set_return_value (struct value *val);
430 extern struct value *evaluate_expression (struct expression *exp);
432 extern struct value *evaluate_type (struct expression *exp);
434 extern struct value *evaluate_subexp_with_coercion (struct expression *,
437 extern struct value *parse_and_eval (char *exp);
439 extern struct value *parse_to_comma_and_eval (char **expp);
441 extern struct type *parse_and_eval_type (char *p, int length);
443 extern CORE_ADDR parse_and_eval_address (char *exp);
445 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
447 extern LONGEST parse_and_eval_long (char *exp);
449 extern struct value *access_value_history (int num);
451 extern struct value *value_of_internalvar (struct internalvar *var);
453 extern void set_internalvar (struct internalvar *var, struct value *val);
455 extern void set_internalvar_component (struct internalvar *var,
457 int bitpos, int bitsize,
458 struct value *newvalue);
460 extern struct internalvar *lookup_internalvar (char *name);
462 extern int value_equal (struct value *arg1, struct value *arg2);
464 extern int value_less (struct value *arg1, struct value *arg2);
466 extern int value_logical_not (struct value *arg1);
470 extern struct value *value_of_this (int complain);
472 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
474 enum exp_opcode otherop,
477 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
480 extern struct value *value_fn_field (struct value ** arg1p, struct fn_field *f,
481 int j, struct type *type, int offset);
483 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
486 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
488 extern int destructor_name_p (const char *name, const struct type *type);
490 #define value_free(val) xfree (val)
492 extern void free_all_values (void);
494 extern void release_value (struct value *val);
496 extern int record_latest_value (struct value *val);
499 modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize);
501 extern void type_print (struct type * type, char *varstring,
502 struct ui_file * stream, int show);
504 extern char *baseclass_addr (struct type *type, int index, char *valaddr,
505 struct value **valuep, int *errp);
507 extern void print_longest (struct ui_file * stream, int format,
508 int use_local, LONGEST val);
510 extern void print_floating (char *valaddr, struct type * type,
511 struct ui_file * stream);
513 extern int value_print (struct value *val, struct ui_file *stream, int format,
514 enum val_prettyprint pretty);
516 extern void value_print_array_elements (struct value *val,
517 struct ui_file *stream, int format,
518 enum val_prettyprint pretty);
520 extern struct value *value_release_to_mark (struct value *mark);
522 extern int val_print (struct type * type, char *valaddr,
523 int embedded_offset, CORE_ADDR address,
524 struct ui_file * stream, int format,
525 int deref_ref, int recurse,
526 enum val_prettyprint pretty);
528 extern int val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream);
530 extern void print_variable_value (struct symbol * var,
531 struct frame_info * frame,
532 struct ui_file *stream);
534 extern int check_field (struct value *, const char *);
536 extern void typedef_print (struct type * type, struct symbol * news,
537 struct ui_file * stream);
539 extern char *internalvar_name (struct internalvar *var);
541 extern void clear_value_history (void);
543 extern void clear_internalvars (void);
547 extern struct value *value_copy (struct value *);
551 extern struct value *varying_to_slice (struct value *);
553 extern struct value *value_slice (struct value *, int, int);
555 extern struct value *call_function_by_hand (struct value *, int,
558 extern int default_coerce_float_to_double (struct type *, struct type *);
560 extern int standard_coerce_float_to_double (struct type *, struct type *);
562 extern struct value *value_literal_complex (struct value *, struct value *,
565 extern void find_rt_vbase_offset (struct type *, struct type *, char *, int,
568 extern struct value *find_function_in_inferior (char *);
570 extern struct value *value_allocate_space_in_inferior (int);
572 extern CORE_ADDR default_push_arguments (int nargs, struct value ** args,
573 CORE_ADDR sp, int struct_return,
574 CORE_ADDR struct_addr);
576 #endif /* !defined (VALUE_H) */