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 30struct block; 31struct expression; 32struct regcache; 33struct symbol; 34struct type; 35struct 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 42struct 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 62 /* Number of register. Only used with lval_reg_frame_relative. */ 63 int regnum; 64 } location; 65 66 /* Describes offset of a value within lval of a structure in bytes. 67 If lval == lval_memory, this is an offset to the address. 68 If lval == lval_register, this is a further offset from 69 location.address within the registers structure. 70 Note also the member embedded_offset below. */ 71 int offset; 72 73 /* Only used for bitfields; number of bits contained in them. */ 74 int bitsize; 75 76 /* Only used for bitfields; position of start of field. 77 For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. 78 For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */ 79 int bitpos; 80 81 /* Frame value is relative to. In practice, this ID is only used if 82 the value is stored in several registers in other than the 83 current frame, and these registers have not all been saved at the 84 same place in memory. This will be described in the lval enum 85 above as "lval_reg_frame_relative". */ 86 struct frame_id frame_id; 87 88 /* Type of the value. */ 89 struct type *type; 90 91 /* If a value represents a C++ object, then the `type' field gives 92 the object's compile-time type. If the object actually belongs 93 to some class derived from `type', perhaps with other base 94 classes and additional members, then `type' is just a subobject 95 of the real thing, and the full object is probably larger than 96 `type' would suggest. 97 98 If `type' is a dynamic class (i.e. one with a vtable), then GDB 99 can actually determine the object's run-time type by looking at 100 the run-time type information in the vtable. When this 101 information is available, we may elect to read in the entire 102 object, for several reasons: 103 104 - When printing the value, the user would probably rather see the 105 full object, not just the limited portion apparent from the 106 compile-time type. 107 108 - If `type' has virtual base classes, then even printing `type' 109 alone may require reaching outside the `type' portion of the 110 object to wherever the virtual base class has been stored. 111 112 When we store the entire object, `enclosing_type' is the run-time 113 type -- the complete object -- and `embedded_offset' is the 114 offset of `type' within that larger type, in bytes. The 115 VALUE_CONTENTS macro takes `embedded_offset' into account, so 116 most GDB code continues to see the `type' portion of the value, 117 just as the inferior would. 118 119 If `type' is a pointer to an object, then `enclosing_type' is a 120 pointer to the object's run-time type, and `pointed_to_offset' is 121 the offset in bytes from the full object to the pointed-to object 122 -- that is, the value `embedded_offset' would have if we 123 followed the pointer and fetched the complete object. (I don't 124 really see the point. Why not just determine the run-time type 125 when you indirect, and avoid the special case? The contents 126 don't matter until you indirect anyway.) 127 128 If we're not doing anything fancy, `enclosing_type' is equal to 129 `type', and `embedded_offset' is zero, so everything works 130 normally. */ 131 struct type *enclosing_type; 132 int embedded_offset; 133 int pointed_to_offset; 134 135 /* Values are stored in a chain, so that they can be deleted 136 easily over calls to the inferior. Values assigned to internal 137 variables or put into the value history are taken off this 138 list. */ 139 struct value *next; 140 141 /* Register number if the value is from a register. */ 142 short regno; 143 144 /* If zero, contents of this value are in the contents field. If 145 nonzero, contents are in inferior memory at address in the 146 location.address field plus the offset field (and the lval 147 field should be lval_memory). 148 149 WARNING: This field is used by the code which handles 150 watchpoints (see breakpoint.c) to decide whether a particular 151 value can be watched by hardware watchpoints. If the lazy flag 152 is set for some member of a value chain, it is assumed that 153 this member of the chain doesn't need to be watched as part of 154 watching the value itself. This is how GDB avoids watching the 155 entire struct or array when the user wants to watch a single 156 struct member or array element. If you ever change the way 157 lazy flag is set and reset, be sure to consider this use as 158 well! */ 159 char lazy; 160 161 /* If nonzero, this is the value of a variable which does not 162 actually exist in the program. */ 163 char optimized_out; 164 165 /* The BFD section associated with this value. */ 166 asection *bfd_section; 167 168 /* Actual contents of the value. For use of this value; setting 169 it uses the stuff above. Not valid if lazy is nonzero. 170 Target byte-order. We force it to be aligned properly for any 171 possible value. Note that a value therefore extends beyond 172 what is declared here. */ 173 union 174 { 175 long contents[1]; 176 DOUBLEST force_doublest_align; 177 LONGEST force_longest_align; 178 CORE_ADDR force_core_addr_align; 179 void *force_pointer_align; 180 } aligner; 181 /* Do not add any new members here -- contents above will trash them. */ 182}; 183 184#define VALUE_TYPE(val) (val)->type 185#define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type 186#define VALUE_LAZY(val) (val)->lazy 187 188/* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of 189 the gdb buffer used to hold a copy of the contents of the lval. 190 VALUE_CONTENTS is used when the contents of the buffer are needed 191 -- it uses value_fetch_lazy() to load the buffer from the process 192 being debugged if it hasn't already been loaded. 193 VALUE_CONTENTS_RAW is used when data is being stored into the 194 buffer, or when it is certain that the contents of the buffer are 195 valid. 196 197 Note: The contents pointer is adjusted by the offset required to 198 get to the real subobject, if the value happens to represent 199 something embedded in a larger run-time object. */ 200 201#define VALUE_CONTENTS_RAW(val) \ 202 ((char *) (val)->aligner.contents + (val)->embedded_offset) 203#define VALUE_CONTENTS(val) \ 204 ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)), VALUE_CONTENTS_RAW(val)) 205 206/* The ALL variants of the above two macros do not adjust the returned 207 pointer by the embedded_offset value. */ 208 209#define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents) 210#define VALUE_CONTENTS_ALL(val) \ 211 ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)), \ 212 VALUE_CONTENTS_ALL_RAW(val)) 213 214extern int value_fetch_lazy (struct value *val); 215 216#define VALUE_LVAL(val) (val)->lval 217#define VALUE_ADDRESS(val) (val)->location.address 218#define VALUE_INTERNALVAR(val) (val)->location.internalvar 219#define VALUE_FRAME_REGNUM(val) ((val)->location.regnum) 220#define VALUE_FRAME_ID(val) ((val)->frame_id) 221#define VALUE_OFFSET(val) (val)->offset 222#define VALUE_BITSIZE(val) (val)->bitsize 223#define VALUE_BITPOS(val) (val)->bitpos 224#define VALUE_NEXT(val) (val)->next 225#define VALUE_REGNO(val) (val)->regno 226#define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out) 227#define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset) 228#define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset) 229#define VALUE_BFD_SECTION(val) ((val)->bfd_section) 230 231/* Convert a REF to the object referenced. */ 232 233#define COERCE_REF(arg) \ 234 do { \ 235 struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg)); \ 236 if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF) \ 237 arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp), \ 238 unpack_pointer (VALUE_TYPE (arg), \ 239 VALUE_CONTENTS (arg)), \ 240 VALUE_BFD_SECTION (arg)); \ 241 } while (0) 242 243/* If ARG is an array, convert it to a pointer. 244 If ARG is an enum, convert it to an integer. 245 If ARG is a function, convert it to a function pointer. 246 247 References are dereferenced. */ 248 249#define COERCE_ARRAY(arg) \ 250 do { \ 251 COERCE_REF(arg); \ 252 if (current_language->c_style_arrays \ 253 && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY) \ 254 arg = value_coerce_array (arg); \ 255 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC) \ 256 arg = value_coerce_function (arg); \ 257 } while (0) 258 259#define COERCE_NUMBER(arg) \ 260 do { COERCE_ARRAY(arg); COERCE_ENUM(arg); } while (0) 261 262/* NOTE: cagney/2002-12-17: This macro was handling a chill language 263 problem but that language has gone away. */ 264#define COERCE_VARYING_ARRAY(arg, real_arg_type) 265 266/* If ARG is an enum, convert it to an integer. */ 267 268#define COERCE_ENUM(arg) \ 269 do { \ 270 if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM) \ 271 arg = value_cast (builtin_type_unsigned_int, arg); \ 272 } while (0) 273 274/* Internal variables (variables for convenience of use of debugger) 275 are recorded as a chain of these structures. */ 276 277struct internalvar 278{ 279 struct internalvar *next; 280 char *name; 281 struct value *value; 282}; 283 284/* Pointer to member function. Depends on compiler implementation. */ 285 286#define METHOD_PTR_IS_VIRTUAL(ADDR) ((ADDR) & 0x80000000) 287#define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET)) 288#define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR)) 289 290 291#include "symtab.h" 292#include "gdbtypes.h" 293#include "expression.h" 294 295struct frame_info; 296struct fn_field; 297 298extern void print_address_demangle (CORE_ADDR, struct ui_file *, int); 299 300extern LONGEST value_as_long (struct value *val); 301extern DOUBLEST value_as_double (struct value *val); 302extern CORE_ADDR value_as_address (struct value *val); 303 304extern LONGEST unpack_long (struct type *type, const char *valaddr); 305extern DOUBLEST unpack_double (struct type *type, const char *valaddr, 306 int *invp); 307extern CORE_ADDR unpack_pointer (struct type *type, const char *valaddr); 308extern LONGEST unpack_field_as_long (struct type *type, const char *valaddr, 309 int fieldno); 310 311extern struct value *value_from_longest (struct type *type, LONGEST num); 312extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr); 313extern struct value *value_from_double (struct type *type, DOUBLEST num); 314extern struct value *value_from_string (char *string); 315 316extern struct value *value_at (struct type *type, CORE_ADDR addr, 317 asection * sect); 318extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr, 319 asection * sect); 320 321extern struct value *value_from_register (struct type *type, int regnum, 322 struct frame_info *frame); 323 324extern struct value *value_of_variable (struct symbol *var, struct block *b); 325 326extern struct value *value_of_register (int regnum, 327 struct frame_info *frame); 328 329extern int symbol_read_needs_frame (struct symbol *); 330 331extern struct value *read_var_value (struct symbol *var, 332 struct frame_info *frame); 333 334extern struct value *locate_var_value (struct symbol *var, 335 struct frame_info *frame); 336 337extern struct value *allocate_value (struct type *type); 338 339extern struct value *allocate_repeat_value (struct type *type, int count); 340 341extern struct value *value_change_enclosing_type (struct value *val, 342 struct type *new_type); 343 344extern struct value *value_mark (void); 345 346extern void value_free_to_mark (struct value *mark); 347 348extern struct value *value_string (char *ptr, int len); 349extern struct value *value_bitstring (char *ptr, int len); 350 351extern struct value *value_array (int lowbound, int highbound, 352 struct value ** elemvec); 353 354extern struct value *value_concat (struct value *arg1, struct value *arg2); 355 356extern struct value *value_binop (struct value *arg1, struct value *arg2, 357 enum exp_opcode op); 358 359extern struct value *value_add (struct value *arg1, struct value *arg2); 360 361extern struct value *value_sub (struct value *arg1, struct value *arg2); 362 363extern struct value *value_coerce_array (struct value *arg1); 364 365extern struct value *value_coerce_function (struct value *arg1); 366 367extern struct value *value_ind (struct value *arg1); 368 369extern struct value *value_addr (struct value *arg1); 370 371extern struct value *value_assign (struct value *toval, struct value *fromval); 372 373extern struct value *value_neg (struct value *arg1); 374 375extern struct value *value_complement (struct value *arg1); 376 377extern struct value *value_struct_elt (struct value **argp, 378 struct value **args, 379 char *name, int *static_memfuncp, 380 char *err); 381 382extern struct value *value_aggregate_elt (struct type *curtype, 383 char *name, 384 enum noside noside); 385 386extern struct value *value_static_field (struct type *type, int fieldno); 387 388extern struct fn_field *value_find_oload_method_list (struct value **, char *, 389 int, int *, 390 struct type **, int *); 391 392extern int find_overload_match (struct type **arg_types, int nargs, 393 char *name, int method, int lax, 394 struct value **objp, struct symbol *fsym, 395 struct value **valp, struct symbol **symp, 396 int *staticp); 397 398extern struct value *value_field (struct value *arg1, int fieldno); 399 400extern struct value *value_primitive_field (struct value *arg1, int offset, 401 int fieldno, 402 struct type *arg_type); 403 404 405extern struct type *value_rtti_target_type (struct value *, int *, int *, 406 int *); 407 408extern struct value *value_full_object (struct value *, struct type *, int, 409 int, int); 410 411extern struct value *value_cast (struct type *type, struct value *arg2); 412 413extern struct value *value_zero (struct type *type, enum lval_type lv); 414 415extern struct value *value_repeat (struct value *arg1, int count); 416 417extern struct value *value_subscript (struct value *array, struct value *idx); 418 419extern struct value *register_value_being_returned (struct type *valtype, 420 struct regcache *retbuf); 421 422extern struct value *value_in (struct value *element, struct value *set); 423 424extern int value_bit_index (struct type *type, char *addr, int index); 425 426extern int using_struct_return (struct type *value_type, int gcc_p); 427 428extern struct value *evaluate_expression (struct expression *exp); 429 430extern struct value *evaluate_type (struct expression *exp); 431 432extern struct value *evaluate_subexp_with_coercion (struct expression *, 433 int *, enum noside); 434 435extern struct value *parse_and_eval (char *exp); 436 437extern struct value *parse_to_comma_and_eval (char **expp); 438 439extern struct type *parse_and_eval_type (char *p, int length); 440 441extern CORE_ADDR parse_and_eval_address (char *exp); 442 443extern CORE_ADDR parse_and_eval_address_1 (char **expptr); 444 445extern LONGEST parse_and_eval_long (char *exp); 446 447extern struct value *access_value_history (int num); 448 449extern struct value *value_of_internalvar (struct internalvar *var); 450 451extern void set_internalvar (struct internalvar *var, struct value *val); 452 453extern void set_internalvar_component (struct internalvar *var, 454 int offset, 455 int bitpos, int bitsize, 456 struct value *newvalue); 457 458extern struct internalvar *lookup_internalvar (char *name); 459 460extern int value_equal (struct value *arg1, struct value *arg2); 461 462extern int value_less (struct value *arg1, struct value *arg2); 463 464extern int value_logical_not (struct value *arg1); 465 466/* C++ */ 467 468extern struct value *value_of_this (int complain); 469 470extern struct value *value_x_binop (struct value *arg1, struct value *arg2, 471 enum exp_opcode op, 472 enum exp_opcode otherop, 473 enum noside noside); 474 475extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op, 476 enum noside noside); 477 478extern struct value *value_fn_field (struct value ** arg1p, struct fn_field *f, 479 int j, struct type *type, int offset); 480 481extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1, 482 struct value *arg2); 483 484extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1); 485 486extern int destructor_name_p (const char *name, const struct type *type); 487 488#define value_free(val) xfree (val) 489 490extern void free_all_values (void); 491 492extern void release_value (struct value *val); 493 494extern int record_latest_value (struct value *val); 495 496extern void modify_field (char *addr, LONGEST fieldval, int bitpos, 497 int bitsize); 498 499extern void type_print (struct type * type, char *varstring, 500 struct ui_file * stream, int show); 501 502extern char *baseclass_addr (struct type *type, int index, char *valaddr, 503 struct value **valuep, int *errp); 504 505extern void print_longest (struct ui_file * stream, int format, 506 int use_local, LONGEST val); 507 508extern void print_floating (char *valaddr, struct type * type, 509 struct ui_file * stream); 510 511extern int value_print (struct value *val, struct ui_file *stream, int format, 512 enum val_prettyprint pretty); 513 514extern void value_print_array_elements (struct value *val, 515 struct ui_file *stream, int format, 516 enum val_prettyprint pretty); 517 518extern struct value *value_release_to_mark (struct value *mark); 519 520extern int val_print (struct type * type, char *valaddr, 521 int embedded_offset, CORE_ADDR address, 522 struct ui_file * stream, int format, 523 int deref_ref, int recurse, 524 enum val_prettyprint pretty); 525 526extern int val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream); 527 528extern void print_variable_value (struct symbol * var, 529 struct frame_info * frame, 530 struct ui_file *stream); 531 532extern int check_field (struct value *, const char *); 533 534extern void typedef_print (struct type * type, struct symbol * news, 535 struct ui_file * stream); 536 537extern char *internalvar_name (struct internalvar *var); 538 539extern void clear_value_history (void); 540 541extern void clear_internalvars (void); 542 543/* From values.c */ 544 545extern struct value *value_copy (struct value *); 546 547/* From valops.c */ 548 549extern struct value *varying_to_slice (struct value *); 550 551extern struct value *value_slice (struct value *, int, int); 552 553extern struct value *value_literal_complex (struct value *, struct value *, 554 struct type *); 555 556extern void find_rt_vbase_offset (struct type *, struct type *, char *, int, 557 int *, int *); 558 559extern struct value *find_function_in_inferior (const char *); 560 561extern struct value *value_allocate_space_in_inferior (int); 562 563extern struct value *value_of_local (const char *name, int complain); 564 565#endif /* !defined (VALUE_H) */ 566