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 (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_pointer (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 (value_ptr val);
 250
 251 extern DOUBLEST value_as_double (value_ptr val);
 252
 253 extern CORE_ADDR value_as_pointer (value_ptr val);
 254
 255 extern LONGEST unpack_long (struct type *type, char *valaddr);
 256
 257 extern DOUBLEST unpack_double (struct type *type, char *valaddr, int *invp);
 258
 259 extern CORE_ADDR unpack_pointer (struct type *type, char *valaddr);
 260
 261 extern LONGEST unpack_field_as_long (struct type *type, char *valaddr,
 262                                      int fieldno);
 263
 264 extern value_ptr value_from_longest (struct type *type, LONGEST num);
 265
 266 extern value_ptr value_from_pointer (struct type *type, CORE_ADDR addr);
 267
 268 extern value_ptr value_from_double (struct type *type, DOUBLEST num);
 269
 270 extern value_ptr value_from_string (char *string);
 271
 272 extern value_ptr value_at (struct type *type, CORE_ADDR addr,
 273                            asection * sect);
 274
 275 extern value_ptr value_at_lazy (struct type *type, CORE_ADDR addr,
 276                                 asection * sect);
 277
 278 extern value_ptr value_from_register (struct type *type, int regnum,
 279                                       struct frame_info *frame);
 280
 281 extern value_ptr value_of_variable (struct symbol *var, struct block *b);
 282
 283 extern value_ptr value_of_register (int regnum);
 284
 285 extern int symbol_read_needs_frame (struct symbol *);
 286
 287 extern value_ptr read_var_value (struct symbol *var,
 288                                  struct frame_info *frame);
 289
 290 extern value_ptr locate_var_value (struct symbol *var,
 291                                    struct frame_info *frame);
 292
 293 extern value_ptr allocate_value (struct type *type);
 294
 295 extern value_ptr allocate_repeat_value (struct type *type, int count);
 296
 297 extern value_ptr value_mark (void);
 298
 299 extern void value_free_to_mark (value_ptr mark);
 300
 301 extern value_ptr value_string (char *ptr, int len);
 302 extern value_ptr value_bitstring (char *ptr, int len);
 303
 304 extern value_ptr value_array (int lowbound, int highbound,
 305                               value_ptr * elemvec);
 306
 307 extern value_ptr value_concat (value_ptr arg1, value_ptr arg2);
 308
 309 extern value_ptr value_binop (value_ptr arg1, value_ptr arg2,
 310                               enum exp_opcode op);
 311
 312 extern value_ptr value_add (value_ptr arg1, value_ptr arg2);
 313
 314 extern value_ptr value_sub (value_ptr arg1, value_ptr arg2);
 315
 316 extern value_ptr value_coerce_array (value_ptr arg1);
 317
 318 extern value_ptr value_coerce_function (value_ptr arg1);
 319
 320 extern value_ptr value_ind (value_ptr arg1);
 321
 322 extern value_ptr value_addr (value_ptr arg1);
 323
 324 extern value_ptr value_assign (value_ptr toval, value_ptr fromval);
 325
 326 extern value_ptr value_neg (value_ptr arg1);
 327
 328 extern value_ptr value_complement (value_ptr arg1);
 329
 330 extern value_ptr value_struct_elt (value_ptr * argp, value_ptr * args,
 331                                    char *name,
 332                                    int *static_memfuncp, char *err);
 333
 334 extern value_ptr value_struct_elt_for_reference (struct type *domain,
 335                                                  int offset,
 336                                                  struct type *curtype,
 337                                                  char *name,
 338                                                  struct type *intype);
 339
 340 extern value_ptr value_static_field (struct type *type, int fieldno);
 341
 342 extern struct fn_field *value_find_oload_method_list (value_ptr *, char *,
 343                                                       int, int *, int *,
 344                                                       struct type **, int *);
 345
 346 extern int find_overload_match (struct type **arg_types, int nargs,
 347                                 char *name, int method, int lax,
 348                                 value_ptr obj, struct symbol *fsym,
 349                                 value_ptr * valp, struct symbol **symp,
 350                                 int *staticp);
 351
 352 extern value_ptr value_field (value_ptr arg1, int fieldno);
 353
 354 extern value_ptr value_primitive_field (value_ptr arg1, int offset,
 355                                         int fieldno, struct type *arg_type);
 356
 357 extern struct type *value_rtti_type (value_ptr, int *, int *, int *);
 358
 359 extern struct type *value_rtti_target_type (value_ptr, int *, int *, int *);
 360
 361 extern value_ptr value_full_object (value_ptr, struct type *, int, int, int);
 362
 363 extern value_ptr value_cast (struct type *type, value_ptr arg2);
 364
 365 extern value_ptr value_zero (struct type *type, enum lval_type lv);
 366
 367 extern value_ptr value_repeat (value_ptr arg1, int count);
 368
 369 extern value_ptr value_subscript (value_ptr array, value_ptr idx);
 370
 371 extern value_ptr value_from_vtable_info (value_ptr arg, struct type *type);
 372
 373 extern value_ptr value_being_returned (struct type *valtype,
 374                                        char *retbuf, int struct_return);
 375
 376 extern value_ptr value_in (value_ptr element, value_ptr set);
 377
 378 extern int value_bit_index (struct type *type, char *addr, int index);
 379
 380 extern int using_struct_return (value_ptr function, CORE_ADDR funcaddr,
 381                                 struct type *value_type, int gcc_p);
 382
 383 extern void set_return_value (value_ptr val);
 384
 385 extern value_ptr evaluate_expression (struct expression *exp);
 386
 387 extern value_ptr evaluate_type (struct expression *exp);
 388
 389 extern value_ptr evaluate_subexp_with_coercion (struct expression *,
 390                                                 int *, enum noside);
 391
 392 extern value_ptr parse_and_eval (char *exp);
 393
 394 extern value_ptr parse_to_comma_and_eval (char **expp);
 395
 396 extern struct type *parse_and_eval_type (char *p, int length);
 397
 398 extern CORE_ADDR parse_and_eval_address (char *exp);
 399
 400 extern CORE_ADDR parse_and_eval_address_1 (char **expptr);
 401
 402 extern value_ptr access_value_history (int num);
 403
 404 extern value_ptr value_of_internalvar (struct internalvar *var);
 405
 406 extern void set_internalvar (struct internalvar *var, value_ptr val);
 407
 408 extern void set_internalvar_component (struct internalvar *var,
 409                                        int offset,
 410                                        int bitpos, int bitsize,
 411                                        value_ptr newvalue);
 412
 413 extern struct internalvar *lookup_internalvar (char *name);
 414
 415 extern int value_equal (value_ptr arg1, value_ptr arg2);
 416
 417 extern int value_less (value_ptr arg1, value_ptr arg2);
 418
 419 extern int value_logical_not (value_ptr arg1);
 420
 421 /* C++ */
 422
 423 extern value_ptr value_of_this (int complain);
 424
 425 extern value_ptr value_x_binop (value_ptr arg1, value_ptr arg2,
 426                                 enum exp_opcode op,
 427                                 enum exp_opcode otherop, enum noside noside);
 428
 429 extern value_ptr value_x_unop (value_ptr arg1, enum exp_opcode op,
 430                                enum noside noside);
 431
 432 extern value_ptr value_fn_field (value_ptr * arg1p, struct fn_field *f,
 433                                  int j, struct type *type, int offset);
 434
 435 extern value_ptr value_virtual_fn_field (value_ptr * arg1p,
 436                                          struct fn_field *f, int j,
 437                                          struct type *type, int offset);
 438
 439 extern int binop_user_defined_p (enum exp_opcode op,
 440                                  value_ptr arg1, value_ptr arg2);
 441
 442 extern int unop_user_defined_p (enum exp_opcode op, value_ptr arg1);
 443
 444 extern int destructor_name_p (const char *name, const struct type *type);
 445
 446 #define value_free(val) free ((PTR)val)
 447
 448 extern void free_all_values (void);
 449
 450 extern void release_value (value_ptr val);
 451
 452 extern int record_latest_value (value_ptr val);
 453
 454 extern void registers_changed (void);
 455
 456 extern void read_register_bytes (int regbyte, char *myaddr, int len);
 457
 458 extern void write_register_bytes (int regbyte, char *myaddr, int len);
 459
 460 extern void read_register_gen (int regno, char *myaddr);
 461
 462 extern void write_register_gen (int regno, char *myaddr);
 463
 464 /* Rename to read_unsigned_register()? */
 465 extern ULONGEST read_register (int regno);
 466
 467 extern LONGEST read_signed_register (int regno);
 468
 469 /* Rename to read_unsigned_register_pid()? */
 470 extern ULONGEST read_register_pid (int regno, int pid);
 471
 472 extern LONGEST read_signed_register_pid (int regno, int pid);
 473
 474 extern void write_register (int regno, LONGEST val);
 475
 476 extern void write_register_pid (int regno, CORE_ADDR val, int pid);
 477
 478 extern void supply_register (int regno, char *val);
 479
 480 extern int register_cached (int regno);
 481
 482 extern void get_saved_register (char *raw_buffer, int *optimized,
 483                                 CORE_ADDR * addrp,
 484                                 struct frame_info *frame,
 485                                 int regnum, enum lval_type *lval);
 486
 487 extern void
 488 modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize);
 489
 490 extern void type_print (struct type * type, char *varstring,
 491                         struct ui_file * stream, int show);
 492
 493 extern char *baseclass_addr (struct type *type, int index,
 494                              char *valaddr, value_ptr * valuep, int *errp);
 495
 496 extern void print_longest (struct ui_file * stream, int format,
 497                            int use_local, LONGEST val);
 498
 499 extern void print_floating (char *valaddr, struct type * type,
 500                             struct ui_file * stream);
 501
 502 extern int value_print (value_ptr val, struct ui_file *stream, int format,
 503                         enum val_prettyprint pretty);
 504
 505 extern void value_print_array_elements (value_ptr val,
 506                                         struct ui_file *stream,
 507                                         int format,
 508                                         enum val_prettyprint pretty);
 509
 510 extern value_ptr value_release_to_mark (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 (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 *internalvar_name (struct internalvar *var);
 530
 531 extern void clear_value_history (void);
 532
 533 extern void clear_internalvars (void);
 534
 535 /* From values.c */
 536
 537 extern value_ptr value_copy (value_ptr);
 538
 539 extern int baseclass_offset (struct type *, int, char *, CORE_ADDR);
 540
 541 /* From valops.c */
 542
 543 extern value_ptr varying_to_slice (value_ptr);
 544
 545 extern value_ptr value_slice (value_ptr, int, int);
 546
 547 extern value_ptr call_function_by_hand (value_ptr, int, value_ptr *);
 548
 549 extern int default_coerce_float_to_double (struct type *, struct type *);
 550
 551 extern int standard_coerce_float_to_double (struct type *, struct type *);
 552
 553 extern value_ptr value_literal_complex (value_ptr, value_ptr, struct type *);
 554
 555 extern void find_rt_vbase_offset (struct type *, struct type *, char *, int,
 556                                   int *, int *);
 557
 558 extern value_ptr find_function_in_inferior (char *);
 559
 560 extern value_ptr value_allocate_space_in_inferior (int);
 561
 562 extern CORE_ADDR default_push_arguments (int nargs, value_ptr * args,
 563                                          CORE_ADDR sp,
 564                                          int struct_return,
 565                                          CORE_ADDR struct_addr);
 566
 567 #endif /* !defined (VALUE_H) */