1 /* Definitions for values of C expressions, for GDB. 2 3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 5 Free Software Foundation, Inc. 6 7 This file is part of GDB. 8 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. 13 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. 18 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. */ 23 24 #if !defined (VALUE_H) 25 #define VALUE_H 1 26 27 #include "doublest.h" 28 #include "frame.h" /* For struct frame_id. */ 29 30 struct block; 31 struct expression; 32 struct regcache; 33 struct symbol; 34 struct type; 35 struct ui_file; 36 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 40 variable). */ 41 42 struct value; 43 44 /* Values are stored in a chain, so that they can be deleted easily 45 over calls to the inferior. Values assigned to internal variables 46 or put into the value history are taken off this list. */ 47 48 struct value *value_next (struct value *); 49 50 /* Type of the value. */ 51 52 extern struct type *value_type (struct value *); 53 54 /* This is being used to change the type of an existing value, that 55 code should instead be creating a new value with the changed type 56 (but possibly shared content). */ 57 58 extern void deprecated_set_value_type (struct value *value, 59 struct type *type); 60 61 /* Only used for bitfields; number of bits contained in them. */ 62 63 extern int value_bitsize (struct value *); 64 extern void set_value_bitsize (struct value *, int bit); 65 66 /* Only used for bitfields; position of start of field. For 67 BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. For 68 BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */ 69 70 extern int value_bitpos (struct value *); 71 extern void set_value_bitpos (struct value *, int bit); 72 73 /* Describes offset of a value within lval of a structure in bytes. 74 If lval == lval_memory, this is an offset to the address. If lval 75 == lval_register, this is a further offset from location.address 76 within the registers structure. Note also the member 77 embedded_offset below. */ 78 79 extern int value_offset (struct value *); 80 extern void set_value_offset (struct value *, int offset); 81 82 /* The comment from "struct value" reads: ``Is it modifiable? Only 83 relevant if lval != not_lval.''. Shouldn't the value instead be 84 not_lval and be done with it? */ 85 86 extern int deprecated_value_modifiable (struct value *value); 87 extern void deprecated_set_value_modifiable (struct value *value, 88 int modifiable); 89 90 /* If a value represents a C++ object, then the `type' field gives the 91 object's compile-time type. If the object actually belongs to some 92 class derived from `type', perhaps with other base classes and 93 additional members, then `type' is just a subobject of the real 94 thing, and the full object is probably larger than `type' would 95 suggest. 96 97 If `type' is a dynamic class (i.e. one with a vtable), then GDB can 98 actually determine the object's run-time type by looking at the 99 run-time type information in the vtable. When this information is 100 available, we may elect to read in the entire object, for several 101 reasons: 102 103 - When printing the value, the user would probably rather see the 104 full object, not just the limited portion apparent from the 105 compile-time type. 106 107 - If `type' has virtual base classes, then even printing `type' 108 alone may require reaching outside the `type' portion of the 109 object to wherever the virtual base class has been stored. 110 111 When we store the entire object, `enclosing_type' is the run-time 112 type -- the complete object -- and `embedded_offset' is the offset 113 of `type' within that larger type, in bytes. The value_contents() 114 macro takes `embedded_offset' into account, so most GDB code 115 continues to see the `type' portion of the value, just as the 116 inferior would. 117 118 If `type' is a pointer to an object, then `enclosing_type' is a 119 pointer to the object's run-time type, and `pointed_to_offset' is 120 the offset in bytes from the full object to the pointed-to object 121 -- that is, the value `embedded_offset' would have if we followed 122 the pointer and fetched the complete object. (I don't really see 123 the point. Why not just determine the run-time type when you 124 indirect, and avoid the special case? The contents don't matter 125 until you indirect anyway.) 126 127 If we're not doing anything fancy, `enclosing_type' is equal to 128 `type', and `embedded_offset' is zero, so everything works 129 normally. */ 130 131 extern struct type *value_enclosing_type (struct value *); 132 extern struct value *value_change_enclosing_type (struct value *val, 133 struct type *new_type); 134 extern int value_pointed_to_offset (struct value *value); 135 extern void set_value_pointed_to_offset (struct value *value, int val); 136 extern int value_embedded_offset (struct value *value); 137 extern void set_value_embedded_offset (struct value *value, int val); 138 139 /* If zero, contents of this value are in the contents field. If 140 nonzero, contents are in inferior memory at address in the 141 location.address field plus the offset field (and the lval field 142 should be lval_memory). 143 144 WARNING: This field is used by the code which handles watchpoints 145 (see breakpoint.c) to decide whether a particular value can be 146 watched by hardware watchpoints. If the lazy flag is set for some 147 member of a value chain, it is assumed that this member of the 148 chain doesn't need to be watched as part of watching the value 149 itself. This is how GDB avoids watching the entire struct or array 150 when the user wants to watch a single struct member or array 151 element. If you ever change the way lazy flag is set and reset, be 152 sure to consider this use as well! */ 153 154 extern int value_lazy (struct value *); 155 extern void set_value_lazy (struct value *value, int val); 156 157 /* value_contents() and value_contents_raw() both return the address 158 of the gdb buffer used to hold a copy of the contents of the lval. 159 value_contents() is used when the contents of the buffer are needed 160 -- it uses value_fetch_lazy() to load the buffer from the process 161 being debugged if it hasn't already been loaded 162 (value_contents_writeable() is used when a writeable but fetched 163 buffer is required).. value_contents_raw() is used when data is 164 being stored into the buffer, or when it is certain that the 165 contents of the buffer are valid. 166 167 Note: The contents pointer is adjusted by the offset required to 168 get to the real subobject, if the value happens to represent 169 something embedded in a larger run-time object. */ 170 171 extern gdb_byte *value_contents_raw (struct value *); 172 173 /* Actual contents of the value. For use of this value; setting it 174 uses the stuff above. Not valid if lazy is nonzero. Target 175 byte-order. We force it to be aligned properly for any possible 176 value. Note that a value therefore extends beyond what is 177 declared here. */ 178 179 extern const gdb_byte *value_contents (struct value *); 180 extern gdb_byte *value_contents_writeable (struct value *); 181 182 /* The ALL variants of the above two macros do not adjust the returned 183 pointer by the embedded_offset value. */ 184 185 extern gdb_byte *value_contents_all_raw (struct value *); 186 extern const gdb_byte *value_contents_all (struct value *); 187 188 extern int value_fetch_lazy (struct value *val); 189 extern int value_contents_equal (struct value *val1, struct value *val2); 190 191 /* If nonzero, this is the value of a variable which does not actually 192 exist in the program. */ 193 extern int value_optimized_out (struct value *value); 194 extern void set_value_optimized_out (struct value *value, int val); 195 196 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a 197 single value might have multiple LVALs), this hacked interface is 198 limited to just the first PIECE. Expect further change. */ 199 /* Type of value; either not an lval, or one of the various different 200 possible kinds of lval. */ 201 extern enum lval_type *deprecated_value_lval_hack (struct value *); 202 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val)) 203 204 /* If lval == lval_memory, this is the address in the inferior. If 205 lval == lval_register, this is the byte offset into the registers 206 structure. */ 207 extern CORE_ADDR *deprecated_value_address_hack (struct value *); 208 #define VALUE_ADDRESS(val) (*deprecated_value_address_hack (val)) 209 210 /* Pointer to internal variable. */ 211 extern struct internalvar **deprecated_value_internalvar_hack (struct value *); 212 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val)) 213 214 /* Frame register value is relative to. This will be described in the 215 lval enum above as "lval_register". */ 216 extern struct frame_id *deprecated_value_frame_id_hack (struct value *); 217 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val)) 218 219 /* Register number if the value is from a register. */ 220 extern short *deprecated_value_regnum_hack (struct value *); 221 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val)) 222 223 /* Convert a REF to the object referenced. */ 224 225 extern struct value *coerce_ref (struct value *value); 226 227 /* If ARG is an array, convert it to a pointer. 228 If ARG is an enum, convert it to an integer. 229 If ARG is a function, convert it to a function pointer. 230 231 References are dereferenced. */ 232 233 extern struct value *coerce_array (struct value *value); 234 extern struct value *coerce_number (struct value *value); 235 236 /* If ARG is an enum, convert it to an integer. */ 237 238 extern struct value *coerce_enum (struct value *value); 239 240 /* Internal variables (variables for convenience of use of debugger) 241 are recorded as a chain of these structures. */ 242 243 struct internalvar 244 { 245 struct internalvar *next; 246 char *name; 247 struct value *value; 248 }; 249 250 251 252 #include "symtab.h" 253 #include "gdbtypes.h" 254 #include "expression.h" 255 256 struct frame_info; 257 struct fn_field; 258 259 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int); 260 261 extern LONGEST value_as_long (struct value *val); 262 extern DOUBLEST value_as_double (struct value *val); 263 extern CORE_ADDR value_as_address (struct value *val); 264 265 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr); 266 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr, 267 int *invp); 268 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr); 269 extern LONGEST unpack_field_as_long (struct type *type, 270 const gdb_byte *valaddr, 271 int fieldno); 272 273 extern struct value *value_from_longest (struct type *type, LONGEST num); 274 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr); 275 extern struct value *value_from_double (struct type *type, DOUBLEST num); 276 extern struct value *value_from_string (char *string); 277 278 extern struct value *value_at (struct type *type, CORE_ADDR addr); 279 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr); 280 281 extern struct value *value_from_register (struct type *type, int regnum, 282 struct frame_info *frame); 283 284 extern struct value *value_of_variable (struct symbol *var, struct block *b); 285 286 extern struct value *value_of_register (int regnum, struct frame_info *frame); 287 288 extern int symbol_read_needs_frame (struct symbol *); 289 290 extern struct value *read_var_value (struct symbol *var, 291 struct frame_info *frame); 292 293 extern struct value *locate_var_value (struct symbol *var, 294 struct frame_info *frame); 295 296 extern struct value *allocate_value (struct type *type); 297 298 extern struct value *allocate_repeat_value (struct type *type, int count); 299 300 extern struct value *value_mark (void); 301 302 extern void value_free_to_mark (struct value *mark); 303 304 extern struct value *value_string (char *ptr, int len); 305 extern struct value *value_bitstring (char *ptr, int len); 306 307 extern struct value *value_array (int lowbound, int highbound, 308 struct value **elemvec); 309 310 extern struct value *value_concat (struct value *arg1, struct value *arg2); 311 312 extern struct value *value_binop (struct value *arg1, struct value *arg2, 313 enum exp_opcode op); 314 315 extern struct value *value_add (struct value *arg1, struct value *arg2); 316 317 extern struct value *value_sub (struct value *arg1, struct value *arg2); 318 319 extern struct value *value_coerce_array (struct value *arg1); 320 321 extern struct value *value_coerce_function (struct value *arg1); 322 323 extern struct value *value_ind (struct value *arg1); 324 325 extern struct value *value_addr (struct value *arg1); 326 327 extern struct value *value_assign (struct value *toval, 328 struct value *fromval); 329 330 extern struct value *value_pos (struct value *arg1); 331 332 extern struct value *value_neg (struct value *arg1); 333 334 extern struct value *value_complement (struct value *arg1); 335 336 extern struct value *value_struct_elt (struct value **argp, 337 struct value **args, 338 char *name, int *static_memfuncp, 339 char *err); 340 341 extern struct value *value_aggregate_elt (struct type *curtype, 342 char *name, enum noside noside); 343 344 extern struct value *value_static_field (struct type *type, int fieldno); 345 346 extern struct fn_field *value_find_oload_method_list (struct value **, char *, 347 int, int *, 348 struct type **, int *); 349 350 extern int find_overload_match (struct type **arg_types, int nargs, 351 char *name, int method, int lax, 352 struct value **objp, struct symbol *fsym, 353 struct value **valp, struct symbol **symp, 354 int *staticp); 355 356 extern struct value *value_field (struct value *arg1, int fieldno); 357 358 extern struct value *value_primitive_field (struct value *arg1, int offset, 359 int fieldno, 360 struct type *arg_type); 361 362 363 extern struct type *value_rtti_target_type (struct value *, int *, int *, 364 int *); 365 366 extern struct value *value_full_object (struct value *, struct type *, int, 367 int, int); 368 369 extern struct value *value_cast (struct type *type, struct value *arg2); 370 371 extern struct value *value_zero (struct type *type, enum lval_type lv); 372 373 extern struct value *value_repeat (struct value *arg1, int count); 374 375 extern struct value *value_subscript (struct value *array, struct value *idx); 376 377 extern struct value *register_value_being_returned (struct type *valtype, 378 struct regcache *retbuf); 379 380 extern struct value *value_in (struct value *element, struct value *set); 381 382 extern int value_bit_index (struct type *type, const gdb_byte *addr, 383 int index); 384 385 extern int using_struct_return (struct type *value_type, int gcc_p); 386 387 extern struct value *evaluate_expression (struct expression *exp); 388 389 extern struct value *evaluate_type (struct expression *exp); 390 391 extern struct value *evaluate_subexp_with_coercion (struct expression *, 392 int *, enum noside); 393 394 extern struct value *parse_and_eval (char *exp); 395 396 extern struct value *parse_to_comma_and_eval (char **expp); 397 398 extern struct type *parse_and_eval_type (char *p, int length); 399 400 extern CORE_ADDR parse_and_eval_address (char *exp); 401 402 extern CORE_ADDR parse_and_eval_address_1 (char **expptr); 403 404 extern LONGEST parse_and_eval_long (char *exp); 405 406 extern struct value *access_value_history (int num); 407 408 extern struct value *value_of_internalvar (struct internalvar *var); 409 410 extern void set_internalvar (struct internalvar *var, struct value *val); 411 412 extern void set_internalvar_component (struct internalvar *var, 413 int offset, 414 int bitpos, int bitsize, 415 struct value *newvalue); 416 417 extern struct internalvar *lookup_internalvar (char *name); 418 419 extern int value_equal (struct value *arg1, struct value *arg2); 420 421 extern int value_less (struct value *arg1, struct value *arg2); 422 423 extern int value_logical_not (struct value *arg1); 424 425 /* C++ */ 426 427 extern struct value *value_of_this (int complain); 428 429 extern struct value *value_x_binop (struct value *arg1, struct value *arg2, 430 enum exp_opcode op, 431 enum exp_opcode otherop, 432 enum noside noside); 433 434 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op, 435 enum noside noside); 436 437 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f, 438 int j, struct type *type, int offset); 439 440 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1, 441 struct value *arg2); 442 443 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1); 444 445 extern int destructor_name_p (const char *name, const struct type *type); 446 447 #define value_free(val) xfree (val) 448 449 extern void free_all_values (void); 450 451 extern void release_value (struct value *val); 452 453 extern int record_latest_value (struct value *val); 454 455 extern void modify_field (gdb_byte *addr, LONGEST fieldval, int bitpos, 456 int bitsize); 457 458 extern void type_print (struct type *type, char *varstring, 459 struct ui_file *stream, int show); 460 461 extern gdb_byte *baseclass_addr (struct type *type, int index, 462 gdb_byte *valaddr, 463 struct value **valuep, int *errp); 464 465 extern void print_longest (struct ui_file *stream, int format, 466 int use_local, LONGEST val); 467 468 extern void print_floating (const gdb_byte *valaddr, struct type *type, 469 struct ui_file *stream); 470 471 extern int value_print (struct value *val, struct ui_file *stream, int format, 472 enum val_prettyprint pretty); 473 474 extern void value_print_array_elements (struct value *val, 475 struct ui_file *stream, int format, 476 enum val_prettyprint pretty); 477 478 extern struct value *value_release_to_mark (struct value *mark); 479 480 extern int val_print (struct type *type, const gdb_byte *valaddr, 481 int embedded_offset, CORE_ADDR address, 482 struct ui_file *stream, int format, 483 int deref_ref, int recurse, 484 enum val_prettyprint pretty); 485 486 extern int common_val_print (struct value *val, 487 struct ui_file *stream, int format, 488 int deref_ref, int recurse, 489 enum val_prettyprint pretty); 490 491 extern int val_print_string (CORE_ADDR addr, int len, int width, 492 struct ui_file *stream); 493 494 extern void print_variable_value (struct symbol *var, 495 struct frame_info *frame, 496 struct ui_file *stream); 497 498 extern int check_field (struct value *, const char *); 499 500 extern void typedef_print (struct type *type, struct symbol *news, 501 struct ui_file *stream); 502 503 extern char *internalvar_name (struct internalvar *var); 504 505 extern void clear_value_history (void); 506 507 extern void clear_internalvars (void); 508 509 /* From values.c */ 510 511 extern struct value *value_copy (struct value *); 512 513 /* From valops.c */ 514 515 extern struct value *varying_to_slice (struct value *); 516 517 extern struct value *value_slice (struct value *, int, int); 518 519 extern struct value *value_literal_complex (struct value *, struct value *, 520 struct type *); 521 522 extern void find_rt_vbase_offset (struct type *, struct type *, 523 const gdb_byte *, int, int *, int *); 524 525 extern struct value *find_function_in_inferior (const char *); 526 527 extern struct value *value_allocate_space_in_inferior (int); 528 529 extern struct value *value_of_local (const char *name, int complain); 530 531 #endif /* !defined (VALUE_H) */ 532