gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2    Copyright 1986, 1987, 1989, 1992-1996, 2000 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #if !defined (VALUE_H)
  22 #define VALUE_H 1
  23
  24 /*
  25  * The structure which defines the type of a value.  It should never
  26  * be possible for a program lval value to survive over a call to the inferior
  27  * (ie to be put into the history list or an internal variable).
  28  */
  29
  30 struct value
  31   {
  32     /* Type of value; either not an lval, or one of the various
  33        different possible kinds of lval.  */
  34     enum lval_type lval;
  35     /* Is it modifiable?  Only relevant if lval != not_lval.  */
  36     int modifiable;
  37     /* Location of value (if lval).  */
  38     union
  39       {
  40         /* If lval == lval_memory, this is the address in the inferior.
  41            If lval == lval_register, this is the byte offset into the
  42            registers structure.  */
  43         CORE_ADDR address;
  44         /* Pointer to internal variable.  */
  45         struct internalvar *internalvar;
  46         /* Number of register.  Only used with
  47            lval_reg_frame_relative.  */
  48         int regnum;
  49       }
  50     location;
  51     /* Describes offset of a value within lval of a structure in bytes.
  52        If lval == lval_memory, this is an offset to the address.
  53        If lval == lval_register, this is a further offset from
  54           location.address within the registers structure.
  55        Note also the member embedded_offset below.  */
  56     int offset;
  57     /* Only used for bitfields; number of bits contained in them.  */
  58     int bitsize;
  59     /* Only used for bitfields; position of start of field.
  60        For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
  61        For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
  62     int bitpos;
  63     /* Frame value is relative to.  In practice, this address is only
  64        used if the value is stored in several registers in other than
  65        the current frame, and these registers have not all been saved
  66        at the same place in memory.  This will be described in the
  67        lval enum above as "lval_reg_frame_relative".  */
  68     CORE_ADDR frame_addr;
  69     /* Type of the value.  */
  70     struct type *type;
  71     /* Type of the enclosing object if this is an embedded subobject.
  72        The member embedded_offset gives the real position of the subobject
  73        if type is not the same as enclosing_type.
  74
  75        If the type field is a pointer type, then enclosing_type is
  76        a pointer type pointing to the real (enclosing) type of the target
  77        object. */
  78     struct type *enclosing_type;
  79     /* Values are stored in a chain, so that they can be deleted
  80        easily over calls to the inferior.  Values assigned to internal
  81        variables or put into the value history are taken off this
  82        list.  */
  83     struct value *next;
  84
  85     /* ??? When is this used?  */
  86     union
  87       {
  88         CORE_ADDR memaddr;
  89         char *myaddr;
  90       }
  91     substring_addr;
  92
  93     /* Register number if the value is from a register.  Is not kept
  94        if you take a field of a structure that is stored in a
  95        register.  Shouldn't it be?  */
  96     short regno;
  97     /* If zero, contents of this value are in the contents field.
  98        If nonzero, contents are in inferior memory at address
  99        in the location.address field plus the offset field
 100        (and the lval field should be lval_memory).  */
 101     char lazy;
 102     /* If nonzero, this is the value of a variable which does not
 103        actually exist in the program.  */
 104     char optimized_out;
 105     /* If this value represents an object that is embedded inside a
 106        larger object (e.g., a base subobject in C++), this gives the
 107        offset (in bytes) from the start of the contents buffer where
 108        the embedded object begins. This is required because some C++
 109        runtime implementations lay out objects (especially virtual bases
 110        with possibly negative offsets to ancestors).
 111        Note: This may be positive or negative! Also note that this offset
 112        is not used when retrieving contents from target memory; the entire
 113        enclosing object has to be retrieved always, and the offset for
 114        that is given by the member offset above. */
 115     int embedded_offset;
 116     /* If this value represents a pointer to an object that is embedded
 117        in another object, this gives the embedded_offset of the object
 118        that is pointed to. */
 119     int pointed_to_offset;
 120     /* The BFD section associated with this value.  */
 121     asection *bfd_section;
 122     /* Actual contents of the value.  For use of this value; setting
 123        it uses the stuff above.  Not valid if lazy is nonzero.
 124        Target byte-order.  We force it to be aligned properly for any
 125        possible value.  Note that a value therefore extends beyond
 126        what is declared here.  */
 127     union
 128       {
 129         long contents[1];
 130         double force_double_align;
 131         LONGEST force_longlong_align;
 132         char *literal_data;
 133       }
 134     aligner;
 135     /* Do not add any new members here -- contents above will trash them */
 136   };
 137
 138 typedef struct value *value_ptr;
 139
 140 #define VALUE_TYPE(val) (val)->type
 141 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
 142 #define VALUE_LAZY(val) (val)->lazy
 143 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
 144    the gdb buffer used to hold a copy of the contents of the lval.
 145    VALUE_CONTENTS is used when the contents of the buffer are needed --
 146    it uses value_fetch_lazy() to load the buffer from the process being
 147    debugged if it hasn't already been loaded.  VALUE_CONTENTS_RAW is
 148    used when data is being stored into the buffer, or when it is
 149    certain that the contents of the buffer are valid.
 150    Note: The contents pointer is adjusted by the offset required to
 151    get to the real subobject, if the value happens to represent
 152    something embedded in a larger run-time object. */
 153
 154 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
 155 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
 156                              VALUE_CONTENTS_RAW(val))
 157
 158 /* The ALL variants of the above two macros do not adjust the returned
 159    pointer by the embedded_offset value. */
 160
 161 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
 162 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
 163                                  VALUE_CONTENTS_ALL_RAW(val))
 164
 165
 166 extern int value_fetch_lazy PARAMS ((value_ptr val));
 167
 168 #define VALUE_LVAL(val) (val)->lval
 169 #define VALUE_ADDRESS(val) (val)->location.address
 170 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
 171 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
 172 #define VALUE_FRAME(val) ((val)->frame_addr)
 173 #define VALUE_OFFSET(val) (val)->offset
 174 #define VALUE_BITSIZE(val) (val)->bitsize
 175 #define VALUE_BITPOS(val) (val)->bitpos
 176 #define VALUE_NEXT(val) (val)->next
 177 #define VALUE_REGNO(val) (val)->regno
 178 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
 179 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
 180 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
 181 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
 182
 183 /* Convert a REF to the object referenced. */
 184
 185 #define COERCE_REF(arg)    \
 186 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
 187      if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)               \
 188          arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),    \
 189                               unpack_long (VALUE_TYPE (arg),            \
 190                                            VALUE_CONTENTS (arg)),       \
 191                               VALUE_BFD_SECTION (arg));                 \
 192     } while (0)
 193
 194 /* If ARG is an array, convert it to a pointer.
 195    If ARG is an enum, convert it to an integer.
 196    If ARG is a function, convert it to a function pointer.
 197
 198    References are dereferenced.  */
 199
 200 #define COERCE_ARRAY(arg)    \
 201 do { COERCE_REF(arg);                                                   \
 202   if (current_language->c_style_arrays                                  \
 203       && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)               \
 204     arg = value_coerce_array (arg);                                     \
 205   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 206     arg = value_coerce_function (arg);                                  \
 207 } while (0)
 208
 209 #define COERCE_NUMBER(arg)  \
 210   do { COERCE_ARRAY(arg);  COERCE_ENUM(arg); } while (0)
 211
 212 #define COERCE_VARYING_ARRAY(arg, real_arg_type)        \
 213 { if (chill_varying_type (real_arg_type))  \
 214     arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }
 215
 216 /* If ARG is an enum, convert it to an integer.  */
 217
 218 #define COERCE_ENUM(arg)   { \
 219   if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM)   \
 220     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 221 }
 222
 223 /* Internal variables (variables for convenience of use of debugger)
 224    are recorded as a chain of these structures.  */
 225
 226 struct internalvar
 227   {
 228     struct internalvar *next;
 229     char *name;
 230     value_ptr value;
 231   };
 232
 233 /* Pointer to member function.  Depends on compiler implementation. */
 234
 235 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 236 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 237 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 238 \f
 239
 240 #include "symtab.h"
 241 #include "gdbtypes.h"
 242 #include "expression.h"
 243
 244 struct frame_info;
 245 struct fn_field;
 246
 247 extern void print_address_demangle (CORE_ADDR, struct ui_file *, int);
 248
 249 extern LONGEST value_as_long PARAMS ((value_ptr val));
 250
 251 extern DOUBLEST value_as_double PARAMS ((value_ptr val));
 252
 253 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 254
 255 extern LONGEST unpack_long PARAMS ((struct type * type, char *valaddr));
 256
 257 extern DOUBLEST unpack_double PARAMS ((struct type * type, char *valaddr,
 258                                        int *invp));
 259
 260 extern CORE_ADDR unpack_pointer PARAMS ((struct type * type, char *valaddr));
 261
 262 extern LONGEST unpack_field_as_long PARAMS ((struct type * type, char *valaddr,
 263                                              int fieldno));
 264
 265 extern value_ptr value_from_longest PARAMS ((struct type * type, LONGEST num));
 266
 267 extern value_ptr value_from_double PARAMS ((struct type * type, DOUBLEST num));
 268
 269 extern value_ptr value_from_string PARAMS ((char *string));
 270
 271 extern value_ptr value_at PARAMS ((struct type * type, CORE_ADDR addr, asection * sect));
 272
 273 extern value_ptr value_at_lazy PARAMS ((struct type * type, CORE_ADDR addr, asection * sect));
 274
 275 extern value_ptr value_from_register PARAMS ((struct type * type, int regnum,
 276                                               struct frame_info * frame));
 277
 278 extern value_ptr value_of_variable PARAMS ((struct symbol * var,
 279                                             struct block * b));
 280
 281 extern value_ptr value_of_register PARAMS ((int regnum));
 282
 283 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 284
 285 extern value_ptr read_var_value PARAMS ((struct symbol * var,
 286                                          struct frame_info * frame));
 287
 288 extern value_ptr locate_var_value PARAMS ((struct symbol * var,
 289                                            struct frame_info * frame));
 290
 291 extern value_ptr allocate_value PARAMS ((struct type * type));
 292
 293 extern value_ptr allocate_repeat_value PARAMS ((struct type * type, int count));
 294
 295 extern value_ptr value_mark PARAMS ((void));
 296
 297 extern void value_free_to_mark PARAMS ((value_ptr mark));
 298
 299 extern value_ptr value_string PARAMS ((char *ptr, int len));
 300 extern value_ptr value_bitstring PARAMS ((char *ptr, int len));
 301
 302 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 303                                       value_ptr * elemvec));
 304
 305 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 306
 307 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 308                                       enum exp_opcode op));
 309
 310 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 311
 312 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 313
 314 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 315
 316 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 317
 318 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 319
 320 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 321
 322 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 323
 324 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 325
 326 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 327
 328 extern value_ptr value_struct_elt PARAMS ((value_ptr * argp, value_ptr * args,
 329                                            char *name,
 330                                            int *static_memfuncp, char *err));
 331
 332 extern value_ptr value_struct_elt_for_reference PARAMS ((struct type * domain,
 333                                                          int offset,
 334                                                       struct type * curtype,
 335                                                          char *name,
 336                                                      struct type * intype));
 337
 338 extern value_ptr value_static_field PARAMS ((struct type * type, int fieldno));
 339
 340 extern struct fn_field *value_find_oload_method_list PARAMS ((value_ptr *, char *, int, int *, int *, struct type **, int *));
 341
 342 extern int find_overload_match PARAMS ((struct type ** arg_types, int nargs, char *name, int method, int lax, value_ptr obj, struct symbol * fsym, value_ptr * valp, struct symbol ** symp, int *staticp));
 343
 344 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 345
 346 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 347                                                 int fieldno,
 348                                                 struct type * arg_type));
 349
 350 extern struct type *
 351   value_rtti_type PARAMS ((value_ptr, int *, int *, int *));
 352
 353 extern struct type *
 354   value_rtti_target_type PARAMS ((value_ptr, int *, int *, int *));
 355
 356 extern value_ptr
 357   value_full_object PARAMS ((value_ptr, struct type *, int, int, int));
 358
 359 extern value_ptr value_cast PARAMS ((struct type * type, value_ptr arg2));
 360
 361 extern value_ptr value_zero PARAMS ((struct type * type, enum lval_type lv));
 362
 363 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 364
 365 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 366
 367 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 368                                                  struct type * type));
 369
 370 extern value_ptr value_being_returned PARAMS ((struct type * valtype,
 371                                                char *retbuf,
 372                                                int struct_return));
 373
 374 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 375
 376 extern int value_bit_index PARAMS ((struct type * type, char *addr, int index));
 377
 378 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 379                                       struct type * value_type, int gcc_p));
 380
 381 extern void set_return_value PARAMS ((value_ptr val));
 382
 383 extern value_ptr evaluate_expression PARAMS ((struct expression * exp));
 384
 385 extern value_ptr evaluate_type PARAMS ((struct expression * exp));
 386
 387 extern value_ptr evaluate_subexp_with_coercion PARAMS ((struct expression *,
 388                                                         int *, enum noside));
 389
 390 extern value_ptr parse_and_eval PARAMS ((char *exp));
 391
 392 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 393
 394 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 395
 396 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 397
 398 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 399
 400 extern value_ptr access_value_history PARAMS ((int num));
 401
 402 extern value_ptr value_of_internalvar PARAMS ((struct internalvar * var));
 403
 404 extern void set_internalvar PARAMS ((struct internalvar * var, value_ptr val));
 405
 406 extern void set_internalvar_component PARAMS ((struct internalvar * var,
 407                                                int offset,
 408                                                int bitpos, int bitsize,
 409                                                value_ptr newvalue));
 410
 411 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 412
 413 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 414
 415 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 416
 417 extern int value_logical_not PARAMS ((value_ptr arg1));
 418
 419 /* C++ */
 420
 421 extern value_ptr value_of_this PARAMS ((int complain));
 422
 423 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 424                                         enum exp_opcode op,
 425                                         enum exp_opcode otherop,
 426                                         enum noside noside));
 427
 428 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op,
 429                                        enum noside noside));
 430
 431 extern value_ptr value_fn_field PARAMS ((value_ptr * arg1p, struct fn_field * f,
 432                                          int j,
 433                                          struct type * type, int offset));
 434
 435 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr * arg1p,
 436                                                  struct fn_field * f, int j,
 437                                                  struct type * type,
 438                                                  int offset));
 439
 440 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 441                                          value_ptr arg1, value_ptr arg2));
 442
 443 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 444
 445 extern int destructor_name_p PARAMS ((const char *name,
 446                                       const struct type * type));
 447
 448 #define value_free(val) free ((PTR)val)
 449
 450 extern void free_all_values PARAMS ((void));
 451
 452 extern void release_value PARAMS ((value_ptr val));
 453
 454 extern int record_latest_value PARAMS ((value_ptr val));
 455
 456 extern void registers_changed PARAMS ((void));
 457
 458 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 459
 460 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 461
 462 extern void
 463 read_register_gen PARAMS ((int regno, char *myaddr));
 464
 465 extern CORE_ADDR
 466   read_register PARAMS ((int regno));
 467
 468 extern CORE_ADDR
 469   read_register_pid PARAMS ((int regno, int pid));
 470
 471 extern void
 472 write_register PARAMS ((int regno, LONGEST val));
 473
 474 extern void
 475 write_register_pid PARAMS ((int regno, CORE_ADDR val, int pid));
 476
 477 extern void
 478 supply_register PARAMS ((int regno, char *val));
 479
 480 extern void get_saved_register PARAMS ((char *raw_buffer, int *optimized,
 481                                         CORE_ADDR * addrp,
 482                                         struct frame_info * frame,
 483                                         int regnum, enum lval_type * lval));
 484
 485 extern void
 486 modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 487
 488 extern void type_print (struct type * type, char *varstring,
 489                         struct ui_file * stream, int show);
 490
 491 extern char *baseclass_addr PARAMS ((struct type * type, int index,
 492                                      char *valaddr,
 493                                      value_ptr * valuep, int *errp));
 494
 495 extern void print_longest (struct ui_file * stream, int format,
 496                            int use_local, LONGEST val);
 497
 498 extern void print_floating (char *valaddr, struct type * type,
 499                             struct ui_file * stream);
 500
 501 extern int value_print (value_ptr val, struct ui_file *stream, int format,
 502                         enum val_prettyprint pretty);
 503
 504 extern void value_print_array_elements (value_ptr val,
 505                                         struct ui_file *stream,
 506                                         int format,
 507                                         enum val_prettyprint pretty);
 508
 509 extern value_ptr
 510   value_release_to_mark PARAMS ((value_ptr mark));
 511
 512 extern int val_print (struct type * type, char *valaddr,
 513                       int embedded_offset, CORE_ADDR address,
 514                       struct ui_file * stream, int format,
 515                       int deref_ref, int recurse,
 516                       enum val_prettyprint pretty);
 517
 518 extern int val_print_string (CORE_ADDR addr, int len, int width, struct ui_file *stream);
 519
 520 extern void print_variable_value (struct symbol * var,
 521                                   struct frame_info * frame,
 522                                   struct ui_file *stream);
 523
 524 extern int check_field PARAMS ((value_ptr, const char *));
 525
 526 extern void c_typedef_print (struct type * type, struct symbol * news,
 527                              struct ui_file * stream);
 528
 529 extern char *
 530   internalvar_name PARAMS ((struct internalvar * var));
 531
 532 extern void
 533 clear_value_history PARAMS ((void));
 534
 535 extern void
 536 clear_internalvars PARAMS ((void));
 537
 538 /* From values.c */
 539
 540 extern value_ptr value_copy PARAMS ((value_ptr));
 541
 542 extern int baseclass_offset PARAMS ((struct type *, int, char *, CORE_ADDR));
 543
 544 /* From valops.c */
 545
 546 extern value_ptr varying_to_slice PARAMS ((value_ptr));
 547
 548 extern value_ptr value_slice PARAMS ((value_ptr, int, int));
 549
 550 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 551
 552 extern value_ptr value_literal_complex PARAMS ((value_ptr, value_ptr, struct type *));
 553
 554 extern void find_rt_vbase_offset PARAMS ((struct type *, struct type *, char *, int, int *, int *));
 555
 556 extern value_ptr find_function_in_inferior PARAMS ((char *));
 557
 558 extern value_ptr value_allocate_space_in_inferior PARAMS ((int));
 559
 560 extern CORE_ADDR default_push_arguments PARAMS ((int nargs, value_ptr * args,
 561                                                  CORE_ADDR sp,
 562                                                  int struct_return,
 563                                                  CORE_ADDR struct_addr));
 564
 565 #endif /* !defined (VALUE_H) */