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 typedef struct value *value_ptr;
179 #define VALUE_TYPE(val) (val)->type
180 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
181 #define VALUE_LAZY(val) (val)->lazy
182 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
183 the gdb buffer used to hold a copy of the contents of the lval.
184 VALUE_CONTENTS is used when the contents of the buffer are needed --
185 it uses value_fetch_lazy() to load the buffer from the process being
186 debugged if it hasn't already been loaded. VALUE_CONTENTS_RAW is
187 used when data is being stored into the buffer, or when it is
188 certain that the contents of the buffer are valid.
189 Note: The contents pointer is adjusted by the offset required to
190 get to the real subobject, if the value happens to represent
191 something embedded in a larger run-time object. */
193 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
194 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
195 VALUE_CONTENTS_RAW(val))
197 /* The ALL variants of the above two macros do not adjust the returned
198 pointer by the embedded_offset value. */
200 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
201 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
202 VALUE_CONTENTS_ALL_RAW(val))
205 extern int value_fetch_lazy (struct value *val);
207 #define VALUE_LVAL(val) (val)->lval
208 #define VALUE_ADDRESS(val) (val)->location.address
209 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
210 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
211 #define VALUE_FRAME(val) ((val)->frame_addr)
212 #define VALUE_OFFSET(val) (val)->offset
213 #define VALUE_BITSIZE(val) (val)->bitsize
214 #define VALUE_BITPOS(val) (val)->bitpos
215 #define VALUE_NEXT(val) (val)->next
216 #define VALUE_REGNO(val) (val)->regno
217 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
218 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
219 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
220 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
222 /* Convert a REF to the object referenced. */
224 #define COERCE_REF(arg) \
225 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
226 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \
227 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \
228 unpack_pointer (VALUE_TYPE (arg), \
229 VALUE_CONTENTS (arg)), \
230 VALUE_BFD_SECTION (arg)); \
233 /* If ARG is an array, convert it to a pointer.
234 If ARG is an enum, convert it to an integer.
235 If ARG is a function, convert it to a function pointer.
237 References are dereferenced. */
239 #define COERCE_ARRAY(arg) \
240 do { COERCE_REF(arg); \
241 if (current_language->c_style_arrays \
242 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \
243 arg = value_coerce_array (arg); \
244 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \
245 arg = value_coerce_function (arg); \
248 #define COERCE_NUMBER(arg) \
249 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0)
251 #define COERCE_VARYING_ARRAY(arg, real_arg_type) \
252 { if (chill_varying_type (real_arg_type)) \
253 arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }
255 /* If ARG is an enum, convert it to an integer. */
257 #define COERCE_ENUM(arg) { \
258 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \
259 arg = value_cast (builtin_type_unsigned_int, arg); \
262 /* Internal variables (variables for convenience of use of debugger)
263 are recorded as a chain of these structures. */
267 struct internalvar *next;
272 /* Pointer to member function. Depends on compiler implementation. */
274 #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000)
275 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
276 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
280 #include "gdbtypes.h"
281 #include "expression.h"
286 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
288 extern LONGEST value_as_long (struct value *val);
290 extern DOUBLEST value_as_double (struct value *val);
292 extern CORE_ADDR value_as_address (struct value *val);
294 extern LONGEST unpack_long (struct type *type, char *valaddr);
296 extern DOUBLEST unpack_double (struct type *type, char *valaddr, int *invp);
298 extern CORE_ADDR unpack_pointer (struct type *type, char *valaddr);
300 extern LONGEST unpack_field_as_long (struct type *type, char *valaddr,
303 extern struct value *value_from_longest (struct type *type, LONGEST num);
305 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
307 extern struct value *value_from_double (struct type *type, DOUBLEST num);
309 extern struct value *value_from_string (char *string);
311 extern struct value *value_at (struct type *type, CORE_ADDR addr,
314 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr,
317 extern struct value *value_from_register (struct type *type, int regnum,
318 struct frame_info *frame);
320 extern struct value *value_of_variable (struct symbol *var, struct block *b);
322 extern struct value *value_of_register (int regnum);
324 extern int symbol_read_needs_frame (struct symbol *);
326 extern struct value *read_var_value (struct symbol *var,
327 struct frame_info *frame);
329 extern struct value *locate_var_value (struct symbol *var,
330 struct frame_info *frame);
332 extern struct value *allocate_value (struct type *type);
334 extern struct value *allocate_repeat_value (struct type *type, int count);
336 extern struct value *value_change_enclosing_type (struct value *val,
337 struct type *new_type);
339 extern struct value *value_mark (void);
341 extern void value_free_to_mark (struct value *mark);
343 extern struct value *value_string (char *ptr, int len);
344 extern struct value *value_bitstring (char *ptr, int len);
346 extern struct value *value_array (int lowbound, int highbound,
347 struct value ** elemvec);
349 extern struct value *value_concat (struct value *arg1, struct value *arg2);
351 extern struct value *value_binop (struct value *arg1, struct value *arg2,
354 extern struct value *value_add (struct value *arg1, struct value *arg2);
356 extern struct value *value_sub (struct value *arg1, struct value *arg2);
358 extern struct value *value_coerce_array (struct value *arg1);
360 extern struct value *value_coerce_function (struct value *arg1);
362 extern struct value *value_ind (struct value *arg1);
364 extern struct value *value_addr (struct value *arg1);
366 extern struct value *value_assign (struct value *toval, struct value *fromval);
368 extern struct value *value_neg (struct value *arg1);
370 extern struct value *value_complement (struct value *arg1);
372 extern struct value *value_struct_elt (struct value **argp,
374 char *name, int *static_memfuncp,
377 extern struct value *value_struct_elt_for_reference (struct type *domain,
379 struct type *curtype,
381 struct type *intype);
383 extern struct value *value_static_field (struct type *type, int fieldno);
385 extern struct fn_field *value_find_oload_method_list (struct value **, char *,
387 struct type **, int *);
389 extern int find_overload_match (struct type **arg_types, int nargs,
390 char *name, int method, int lax,
391 struct value *obj, struct symbol *fsym,
392 struct value **valp, struct symbol **symp,
395 extern struct value *value_field (struct value *arg1, int fieldno);
397 extern struct value *value_primitive_field (struct value *arg1, int offset,
399 struct type *arg_type);
402 extern struct type *value_rtti_target_type (struct value *, int *, int *,
405 extern struct value *value_full_object (struct value *, struct type *, int,
408 extern struct value *value_cast (struct type *type, struct value *arg2);
410 extern struct value *value_zero (struct type *type, enum lval_type lv);
412 extern struct value *value_repeat (struct value *arg1, int count);
414 extern struct value *value_subscript (struct value *array, struct value *idx);
416 extern struct value *value_from_vtable_info (struct value *arg,
419 extern struct value *value_being_returned (struct type *valtype,
420 char *retbuf, int struct_return);
422 extern struct value *value_in (struct value *element, struct value *set);
424 extern int value_bit_index (struct type *type, char *addr, int index);
426 extern int using_struct_return (struct value *function, CORE_ADDR funcaddr,
427 struct type *value_type, int gcc_p);
429 extern void set_return_value (struct value *val);
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);
500 modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize);
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 val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream);
531 extern void print_variable_value (struct symbol * var,
532 struct frame_info * frame,
533 struct ui_file *stream);
535 extern int check_field (struct value *, const char *);
537 extern void typedef_print (struct type * type, struct symbol * news,
538 struct ui_file * stream);
540 extern char *internalvar_name (struct internalvar *var);
542 extern void clear_value_history (void);
544 extern void clear_internalvars (void);
548 extern struct value *value_copy (struct value *);
550 extern int baseclass_offset (struct type *, int, char *, CORE_ADDR);
554 extern struct value *varying_to_slice (struct value *);
556 extern struct value *value_slice (struct value *, int, int);
558 extern struct value *call_function_by_hand (struct value *, int,
561 extern int default_coerce_float_to_double (struct type *, struct type *);
563 extern int standard_coerce_float_to_double (struct type *, struct type *);
565 extern struct value *value_literal_complex (struct value *, struct value *,
568 extern void find_rt_vbase_offset (struct type *, struct type *, char *, int,
571 extern struct value *find_function_in_inferior (char *);
573 extern struct value *value_allocate_space_in_inferior (int);
575 extern CORE_ADDR default_push_arguments (int nargs, struct value ** args,
576 CORE_ADDR sp, int struct_return,
577 CORE_ADDR struct_addr);
579 #endif /* !defined (VALUE_H) */