| 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 |
| 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 | /* Type of value; either not an lval, or one of the various |
| 45 | different possible kinds of lval. */ |
| 46 | enum lval_type lval; |
| 47 | |
| 48 | /* Is it modifiable? Only relevant if lval != not_lval. */ |
| 49 | int modifiable; |
| 50 | |
| 51 | /* Location of value (if lval). */ |
| 52 | union |
| 53 | { |
| 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. */ |
| 57 | CORE_ADDR address; |
| 58 | |
| 59 | /* Pointer to internal variable. */ |
| 60 | struct internalvar *internalvar; |
| 61 | } location; |
| 62 | |
| 63 | /* Describes offset of a value within lval of a structure in bytes. |
| 64 | If lval == lval_memory, this is an offset to the address. If |
| 65 | lval == lval_register, this is a further offset from |
| 66 | location.address within the registers structure. Note also the |
| 67 | member embedded_offset below. */ |
| 68 | int offset; |
| 69 | |
| 70 | /* Only used for bitfields; number of bits contained in them. */ |
| 71 | int bitsize; |
| 72 | |
| 73 | /* Only used for bitfields; position of start of field. For |
| 74 | BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. For |
| 75 | BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */ |
| 76 | int bitpos; |
| 77 | |
| 78 | /* Frame register value is relative to. This will be described in |
| 79 | the lval enum above as "lval_register". */ |
| 80 | struct frame_id frame_id; |
| 81 | |
| 82 | /* Type of the value. */ |
| 83 | struct type *type; |
| 84 | |
| 85 | /* If a value represents a C++ object, then the `type' field gives |
| 86 | the object's compile-time type. If the object actually belongs |
| 87 | to some class derived from `type', perhaps with other base |
| 88 | classes and additional members, then `type' is just a subobject |
| 89 | of the real thing, and the full object is probably larger than |
| 90 | `type' would suggest. |
| 91 | |
| 92 | If `type' is a dynamic class (i.e. one with a vtable), then GDB |
| 93 | can actually determine the object's run-time type by looking at |
| 94 | the run-time type information in the vtable. When this |
| 95 | information is available, we may elect to read in the entire |
| 96 | object, for several reasons: |
| 97 | |
| 98 | - When printing the value, the user would probably rather see the |
| 99 | full object, not just the limited portion apparent from the |
| 100 | compile-time type. |
| 101 | |
| 102 | - If `type' has virtual base classes, then even printing `type' |
| 103 | alone may require reaching outside the `type' portion of the |
| 104 | object to wherever the virtual base class has been stored. |
| 105 | |
| 106 | When we store the entire object, `enclosing_type' is the run-time |
| 107 | type -- the complete object -- and `embedded_offset' is the |
| 108 | offset of `type' within that larger type, in bytes. The |
| 109 | VALUE_CONTENTS macro takes `embedded_offset' into account, so |
| 110 | most GDB code continues to see the `type' portion of the value, |
| 111 | just as the inferior would. |
| 112 | |
| 113 | If `type' is a pointer to an object, then `enclosing_type' is a |
| 114 | pointer to the object's run-time type, and `pointed_to_offset' is |
| 115 | the offset in bytes from the full object to the pointed-to object |
| 116 | -- that is, the value `embedded_offset' would have if we followed |
| 117 | the pointer and fetched the complete object. (I don't really see |
| 118 | the point. Why not just determine the run-time type when you |
| 119 | indirect, and avoid the special case? The contents don't matter |
| 120 | until you indirect anyway.) |
| 121 | |
| 122 | If we're not doing anything fancy, `enclosing_type' is equal to |
| 123 | `type', and `embedded_offset' is zero, so everything works |
| 124 | normally. */ |
| 125 | struct type *enclosing_type; |
| 126 | int embedded_offset; |
| 127 | int pointed_to_offset; |
| 128 | |
| 129 | /* Values are stored in a chain, so that they can be deleted easily |
| 130 | over calls to the inferior. Values assigned to internal |
| 131 | variables or put into the value history are taken off this |
| 132 | list. */ |
| 133 | struct value *next; |
| 134 | |
| 135 | /* Register number if the value is from a register. */ |
| 136 | short regnum; |
| 137 | |
| 138 | /* If zero, contents of this value are in the contents field. If |
| 139 | nonzero, contents are in inferior memory at address in the |
| 140 | location.address field plus the offset field (and the lval field |
| 141 | should be lval_memory). |
| 142 | |
| 143 | WARNING: This field is used by the code which handles watchpoints |
| 144 | (see breakpoint.c) to decide whether a particular value can be |
| 145 | watched by hardware watchpoints. If the lazy flag is set for |
| 146 | some member of a value chain, it is assumed that this member of |
| 147 | the chain doesn't need to be watched as part of watching the |
| 148 | value itself. This is how GDB avoids watching the entire struct |
| 149 | or array when the user wants to watch a single struct member or |
| 150 | array element. If you ever change the way lazy flag is set and |
| 151 | reset, be sure to consider this use as well! */ |
| 152 | char lazy; |
| 153 | |
| 154 | /* If nonzero, this is the value of a variable which does not |
| 155 | actually exist in the program. */ |
| 156 | char optimized_out; |
| 157 | |
| 158 | /* Actual contents of the value. For use of this value; setting it |
| 159 | uses the stuff above. Not valid if lazy is nonzero. Target |
| 160 | byte-order. We force it to be aligned properly for any possible |
| 161 | value. Note that a value therefore extends beyond what is |
| 162 | declared here. */ |
| 163 | union |
| 164 | { |
| 165 | long contents[1]; |
| 166 | DOUBLEST force_doublest_align; |
| 167 | LONGEST force_longest_align; |
| 168 | CORE_ADDR force_core_addr_align; |
| 169 | void *force_pointer_align; |
| 170 | } aligner; |
| 171 | /* Do not add any new members here -- contents above will trash |
| 172 | them. */ |
| 173 | }; |
| 174 | |
| 175 | |
| 176 | extern struct type *value_type (struct value *); |
| 177 | extern int value_bitsize (struct value *); |
| 178 | extern int value_bitpos (struct value *); |
| 179 | extern int value_offset (struct value *); |
| 180 | |
| 181 | #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type |
| 182 | #define VALUE_LAZY(val) (val)->lazy |
| 183 | |
| 184 | /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of |
| 185 | the gdb buffer used to hold a copy of the contents of the lval. |
| 186 | VALUE_CONTENTS is used when the contents of the buffer are needed |
| 187 | -- it uses value_fetch_lazy() to load the buffer from the process |
| 188 | being debugged if it hasn't already been loaded. |
| 189 | VALUE_CONTENTS_RAW is used when data is being stored into the |
| 190 | buffer, or when it is certain that the contents of the buffer are |
| 191 | valid. |
| 192 | |
| 193 | Note: The contents pointer is adjusted by the offset required to |
| 194 | get to the real subobject, if the value happens to represent |
| 195 | something embedded in a larger run-time object. */ |
| 196 | |
| 197 | #define VALUE_CONTENTS_RAW(val) \ |
| 198 | ((char *) (val)->aligner.contents + (val)->embedded_offset) |
| 199 | #define VALUE_CONTENTS(val) \ |
| 200 | ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)), VALUE_CONTENTS_RAW(val)) |
| 201 | |
| 202 | /* The ALL variants of the above two macros do not adjust the returned |
| 203 | pointer by the embedded_offset value. */ |
| 204 | |
| 205 | #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents) |
| 206 | #define VALUE_CONTENTS_ALL(val) \ |
| 207 | ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)), \ |
| 208 | VALUE_CONTENTS_ALL_RAW(val)) |
| 209 | |
| 210 | extern int value_fetch_lazy (struct value *val); |
| 211 | |
| 212 | #define VALUE_LVAL(val) (val)->lval |
| 213 | #define VALUE_ADDRESS(val) (val)->location.address |
| 214 | #define VALUE_INTERNALVAR(val) (val)->location.internalvar |
| 215 | #define VALUE_FRAME_ID(val) ((val)->frame_id) |
| 216 | #define VALUE_REGNUM(val) (val)->regnum |
| 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 | |
| 221 | /* Convert a REF to the object referenced. */ |
| 222 | |
| 223 | extern struct value *coerce_ref (struct value *value); |
| 224 | |
| 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. |
| 228 | |
| 229 | References are dereferenced. */ |
| 230 | |
| 231 | extern struct value *coerce_array (struct value *value); |
| 232 | extern struct value *coerce_number (struct value *value); |
| 233 | |
| 234 | /* If ARG is an enum, convert it to an integer. */ |
| 235 | |
| 236 | extern struct value *coerce_enum (struct value *value); |
| 237 | |
| 238 | /* Internal variables (variables for convenience of use of debugger) |
| 239 | are recorded as a chain of these structures. */ |
| 240 | |
| 241 | struct internalvar |
| 242 | { |
| 243 | struct internalvar *next; |
| 244 | char *name; |
| 245 | struct value *value; |
| 246 | }; |
| 247 | |
| 248 | /* Pointer to member function. Depends on compiler implementation. */ |
| 249 | |
| 250 | #define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000) |
| 251 | #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET)) |
| 252 | #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR)) |
| 253 | \f |
| 254 | |
| 255 | #include "symtab.h" |
| 256 | #include "gdbtypes.h" |
| 257 | #include "expression.h" |
| 258 | |
| 259 | struct frame_info; |
| 260 | struct fn_field; |
| 261 | |
| 262 | extern void print_address_demangle (CORE_ADDR, struct ui_file *, int); |
| 263 | |
| 264 | extern LONGEST value_as_long (struct value *val); |
| 265 | extern DOUBLEST value_as_double (struct value *val); |
| 266 | extern CORE_ADDR value_as_address (struct value *val); |
| 267 | |
| 268 | extern LONGEST unpack_long (struct type *type, const char *valaddr); |
| 269 | extern DOUBLEST unpack_double (struct type *type, const char *valaddr, |
| 270 | int *invp); |
| 271 | extern CORE_ADDR unpack_pointer (struct type *type, const char *valaddr); |
| 272 | extern LONGEST unpack_field_as_long (struct type *type, const char *valaddr, |
| 273 | int fieldno); |
| 274 | |
| 275 | extern struct value *value_from_longest (struct type *type, LONGEST num); |
| 276 | extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr); |
| 277 | extern struct value *value_from_double (struct type *type, DOUBLEST num); |
| 278 | extern struct value *value_from_string (char *string); |
| 279 | |
| 280 | extern struct value *value_at (struct type *type, CORE_ADDR addr); |
| 281 | extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr); |
| 282 | |
| 283 | extern struct value *value_from_register (struct type *type, int regnum, |
| 284 | struct frame_info *frame); |
| 285 | |
| 286 | extern struct value *value_of_variable (struct symbol *var, struct block *b); |
| 287 | |
| 288 | extern struct value *value_of_register (int regnum, struct frame_info *frame); |
| 289 | |
| 290 | extern int symbol_read_needs_frame (struct symbol *); |
| 291 | |
| 292 | extern struct value *read_var_value (struct symbol *var, |
| 293 | struct frame_info *frame); |
| 294 | |
| 295 | extern struct value *locate_var_value (struct symbol *var, |
| 296 | struct frame_info *frame); |
| 297 | |
| 298 | extern struct value *allocate_value (struct type *type); |
| 299 | |
| 300 | extern struct value *allocate_repeat_value (struct type *type, int count); |
| 301 | |
| 302 | extern struct value *value_change_enclosing_type (struct value *val, |
| 303 | struct type *new_type); |
| 304 | |
| 305 | extern struct value *value_mark (void); |
| 306 | |
| 307 | extern void value_free_to_mark (struct value *mark); |
| 308 | |
| 309 | extern struct value *value_string (char *ptr, int len); |
| 310 | extern struct value *value_bitstring (char *ptr, int len); |
| 311 | |
| 312 | extern struct value *value_array (int lowbound, int highbound, |
| 313 | struct value **elemvec); |
| 314 | |
| 315 | extern struct value *value_concat (struct value *arg1, struct value *arg2); |
| 316 | |
| 317 | extern struct value *value_binop (struct value *arg1, struct value *arg2, |
| 318 | enum exp_opcode op); |
| 319 | |
| 320 | extern struct value *value_add (struct value *arg1, struct value *arg2); |
| 321 | |
| 322 | extern struct value *value_sub (struct value *arg1, struct value *arg2); |
| 323 | |
| 324 | extern struct value *value_coerce_array (struct value *arg1); |
| 325 | |
| 326 | extern struct value *value_coerce_function (struct value *arg1); |
| 327 | |
| 328 | extern struct value *value_ind (struct value *arg1); |
| 329 | |
| 330 | extern struct value *value_addr (struct value *arg1); |
| 331 | |
| 332 | extern struct value *value_assign (struct value *toval, |
| 333 | struct value *fromval); |
| 334 | |
| 335 | extern struct value *value_neg (struct value *arg1); |
| 336 | |
| 337 | extern struct value *value_complement (struct value *arg1); |
| 338 | |
| 339 | extern struct value *value_struct_elt (struct value **argp, |
| 340 | struct value **args, |
| 341 | char *name, int *static_memfuncp, |
| 342 | char *err); |
| 343 | |
| 344 | extern struct value *value_aggregate_elt (struct type *curtype, |
| 345 | char *name, enum noside noside); |
| 346 | |
| 347 | extern struct value *value_static_field (struct type *type, int fieldno); |
| 348 | |
| 349 | extern struct fn_field *value_find_oload_method_list (struct value **, char *, |
| 350 | int, int *, |
| 351 | struct type **, int *); |
| 352 | |
| 353 | extern int find_overload_match (struct type **arg_types, int nargs, |
| 354 | char *name, int method, int lax, |
| 355 | struct value **objp, struct symbol *fsym, |
| 356 | struct value **valp, struct symbol **symp, |
| 357 | int *staticp); |
| 358 | |
| 359 | extern struct value *value_field (struct value *arg1, int fieldno); |
| 360 | |
| 361 | extern struct value *value_primitive_field (struct value *arg1, int offset, |
| 362 | int fieldno, |
| 363 | struct type *arg_type); |
| 364 | |
| 365 | |
| 366 | extern struct type *value_rtti_target_type (struct value *, int *, int *, |
| 367 | int *); |
| 368 | |
| 369 | extern struct value *value_full_object (struct value *, struct type *, int, |
| 370 | int, int); |
| 371 | |
| 372 | extern struct value *value_cast (struct type *type, struct value *arg2); |
| 373 | |
| 374 | extern struct value *value_zero (struct type *type, enum lval_type lv); |
| 375 | |
| 376 | extern struct value *value_repeat (struct value *arg1, int count); |
| 377 | |
| 378 | extern struct value *value_subscript (struct value *array, struct value *idx); |
| 379 | |
| 380 | extern struct value *register_value_being_returned (struct type *valtype, |
| 381 | struct regcache *retbuf); |
| 382 | |
| 383 | extern struct value *value_in (struct value *element, struct value *set); |
| 384 | |
| 385 | extern int value_bit_index (struct type *type, char *addr, int index); |
| 386 | |
| 387 | extern int using_struct_return (struct type *value_type, int gcc_p); |
| 388 | |
| 389 | extern struct value *evaluate_expression (struct expression *exp); |
| 390 | |
| 391 | extern struct value *evaluate_type (struct expression *exp); |
| 392 | |
| 393 | extern struct value *evaluate_subexp_with_coercion (struct expression *, |
| 394 | int *, enum noside); |
| 395 | |
| 396 | extern struct value *parse_and_eval (char *exp); |
| 397 | |
| 398 | extern struct value *parse_to_comma_and_eval (char **expp); |
| 399 | |
| 400 | extern struct type *parse_and_eval_type (char *p, int length); |
| 401 | |
| 402 | extern CORE_ADDR parse_and_eval_address (char *exp); |
| 403 | |
| 404 | extern CORE_ADDR parse_and_eval_address_1 (char **expptr); |
| 405 | |
| 406 | extern LONGEST parse_and_eval_long (char *exp); |
| 407 | |
| 408 | extern struct value *access_value_history (int num); |
| 409 | |
| 410 | extern struct value *value_of_internalvar (struct internalvar *var); |
| 411 | |
| 412 | extern void set_internalvar (struct internalvar *var, struct value *val); |
| 413 | |
| 414 | extern void set_internalvar_component (struct internalvar *var, |
| 415 | int offset, |
| 416 | int bitpos, int bitsize, |
| 417 | struct value *newvalue); |
| 418 | |
| 419 | extern struct internalvar *lookup_internalvar (char *name); |
| 420 | |
| 421 | extern int value_equal (struct value *arg1, struct value *arg2); |
| 422 | |
| 423 | extern int value_less (struct value *arg1, struct value *arg2); |
| 424 | |
| 425 | extern int value_logical_not (struct value *arg1); |
| 426 | |
| 427 | /* C++ */ |
| 428 | |
| 429 | extern struct value *value_of_this (int complain); |
| 430 | |
| 431 | extern struct value *value_x_binop (struct value *arg1, struct value *arg2, |
| 432 | enum exp_opcode op, |
| 433 | enum exp_opcode otherop, |
| 434 | enum noside noside); |
| 435 | |
| 436 | extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op, |
| 437 | enum noside noside); |
| 438 | |
| 439 | extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f, |
| 440 | int j, struct type *type, int offset); |
| 441 | |
| 442 | extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1, |
| 443 | struct value *arg2); |
| 444 | |
| 445 | extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1); |
| 446 | |
| 447 | extern int destructor_name_p (const char *name, const struct type *type); |
| 448 | |
| 449 | #define value_free(val) xfree (val) |
| 450 | |
| 451 | extern void free_all_values (void); |
| 452 | |
| 453 | extern void release_value (struct value *val); |
| 454 | |
| 455 | extern int record_latest_value (struct value *val); |
| 456 | |
| 457 | extern void modify_field (char *addr, LONGEST fieldval, int bitpos, |
| 458 | int bitsize); |
| 459 | |
| 460 | extern void type_print (struct type *type, char *varstring, |
| 461 | struct ui_file *stream, int show); |
| 462 | |
| 463 | extern char *baseclass_addr (struct type *type, int index, char *valaddr, |
| 464 | struct value **valuep, int *errp); |
| 465 | |
| 466 | extern void print_longest (struct ui_file *stream, int format, |
| 467 | int use_local, LONGEST val); |
| 468 | |
| 469 | extern void print_floating (char *valaddr, struct type *type, |
| 470 | struct ui_file *stream); |
| 471 | |
| 472 | extern int value_print (struct value *val, struct ui_file *stream, int format, |
| 473 | enum val_prettyprint pretty); |
| 474 | |
| 475 | extern void value_print_array_elements (struct value *val, |
| 476 | struct ui_file *stream, int format, |
| 477 | enum val_prettyprint pretty); |
| 478 | |
| 479 | extern struct value *value_release_to_mark (struct value *mark); |
| 480 | |
| 481 | extern int val_print (struct type *type, char *valaddr, |
| 482 | int embedded_offset, CORE_ADDR address, |
| 483 | struct ui_file *stream, int format, |
| 484 | int deref_ref, int recurse, |
| 485 | enum val_prettyprint pretty); |
| 486 | |
| 487 | extern int val_print_string (CORE_ADDR addr, int len, int width, |
| 488 | struct ui_file *stream); |
| 489 | |
| 490 | extern void print_variable_value (struct symbol *var, |
| 491 | struct frame_info *frame, |
| 492 | struct ui_file *stream); |
| 493 | |
| 494 | extern int check_field (struct value *, const char *); |
| 495 | |
| 496 | extern void typedef_print (struct type *type, struct symbol *news, |
| 497 | struct ui_file *stream); |
| 498 | |
| 499 | extern char *internalvar_name (struct internalvar *var); |
| 500 | |
| 501 | extern void clear_value_history (void); |
| 502 | |
| 503 | extern void clear_internalvars (void); |
| 504 | |
| 505 | /* From values.c */ |
| 506 | |
| 507 | extern struct value *value_copy (struct value *); |
| 508 | |
| 509 | /* From valops.c */ |
| 510 | |
| 511 | extern struct value *varying_to_slice (struct value *); |
| 512 | |
| 513 | extern struct value *value_slice (struct value *, int, int); |
| 514 | |
| 515 | extern struct value *value_literal_complex (struct value *, struct value *, |
| 516 | struct type *); |
| 517 | |
| 518 | extern void find_rt_vbase_offset (struct type *, struct type *, char *, int, |
| 519 | int *, int *); |
| 520 | |
| 521 | extern struct value *find_function_in_inferior (const char *); |
| 522 | |
| 523 | extern struct value *value_allocate_space_in_inferior (int); |
| 524 | |
| 525 | extern struct value *value_of_local (const char *name, int complain); |
| 526 | |
| 527 | #endif /* !defined (VALUE_H) */ |