gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2    Copyright 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, 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 enum lval_type {
  30   /* Not an lval.  */
  31   not_lval,
  32   /* In memory.  Could be a saved register.  */
  33   lval_memory,
  34   /* In a register.  */
  35   lval_register,
  36   /* In a gdb internal variable.  */
  37   lval_internalvar,
  38   /* Part of a gdb internal variable (structure field).  */
  39   lval_internalvar_component,
  40   /* In a register series in a frame not the current one, which may have been
  41      partially saved or saved in different places (otherwise would be
  42      lval_register or lval_memory).  */
  43   lval_reg_frame_relative
  44 };
  45
  46 struct value
  47   {
  48     /* Type of value; either not an lval, or one of the various
  49        different possible kinds of lval.  */
  50     enum lval_type lval;
  51     /* Is it modifiable?  Only relevant if lval != not_lval.  */
  52     int modifiable;
  53     /* Location of value (if lval).  */
  54     union
  55       {
  56         /* Address in inferior or byte of registers structure.  */
  57         CORE_ADDR address;
  58         /* Pointer to internal variable.  */
  59         struct internalvar *internalvar;
  60         /* Number of register.  Only used with
  61            lval_reg_frame_relative.  */
  62         int regnum;
  63       } location;
  64     /* Describes offset of a value within lval of a structure in bytes.
  65        This is used in retrieving contents from target memory. [Note also
  66        the member embedded_offset below.] */
  67     int offset;
  68     /* Only used for bitfields; number of bits contained in them.  */
  69     int bitsize;
  70     /* Only used for bitfields; position of start of field.
  71        For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
  72        For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
  73     int bitpos;
  74     /* Frame value is relative to.  In practice, this address is only
  75        used if the value is stored in several registers in other than
  76        the current frame, and these registers have not all been saved
  77        at the same place in memory.  This will be described in the
  78        lval enum above as "lval_reg_frame_relative".  */
  79     CORE_ADDR frame_addr;
  80     /* Type of the value.  */
  81     struct type *type;
  82     /* Type of the enclosing object if this is an embedded subobject.
  83        The member embedded_offset gives the real position of the subobject
  84        if type is not the same as enclosing_type.
  85
  86        If the type field is a pointer type, then enclosing_type is
  87        a pointer type pointing to the real (enclosing) type of the target
  88        object. */
  89     struct type *enclosing_type;
  90     /* Values are stored in a chain, so that they can be deleted
  91        easily over calls to the inferior.  Values assigned to internal
  92        variables or put into the value history are taken off this
  93        list.  */
  94     struct value *next;
  95
  96     /* ??? When is this used?  */
  97     union {
  98       CORE_ADDR memaddr;
  99       char *myaddr;
 100     } substring_addr;
 101
 102     /* Register number if the value is from a register.  Is not kept
 103        if you take a field of a structure that is stored in a
 104        register.  Shouldn't it be?  */
 105     short regno;
 106     /* If zero, contents of this value are in the contents field.
 107        If nonzero, contents are in inferior memory at address
 108        in the location.address field plus the offset field
 109        (and the lval field should be lval_memory).  */
 110     char lazy;
 111     /* If nonzero, this is the value of a variable which does not
 112        actually exist in the program.  */
 113     char optimized_out;
 114     /* If this value represents an object that is embedded inside a
 115        larger object (e.g., a base subobject in C++), this gives the
 116        offset (in bytes) from the start of the contents buffer where
 117        the embedded object begins. This is required because some C++
 118        runtime implementations lay out objects (especially virtual bases
 119        with possibly negative offsets to ancestors).
 120        Note: This may be positive or negative! Also note that this offset
 121        is not used when retrieving contents from target memory; the entire
 122        enclosing object has to be retrieved always, and the offset for
 123        that is given by the member offset above. */
 124     int embedded_offset;
 125     /* If this value represents a pointer to an object that is embedded
 126        in another object, this gives the embedded_offset of the object
 127        that is pointed to. */
 128     int pointed_to_offset;
 129     /* The BFD section associated with this value.  */
 130     asection *bfd_section;
 131     /* Actual contents of the value.  For use of this value; setting
 132        it uses the stuff above.  Not valid if lazy is nonzero.
 133        Target byte-order.  We force it to be aligned properly for any
 134        possible value.  Note that a value therefore extends beyond
 135        what is declared here.  */
 136     union {
 137       long contents[1];
 138       double force_double_align;
 139       LONGEST force_longlong_align;
 140       char *literal_data;
 141     } aligner;
 142     /* Do not add any new members here -- contents above will trash them */
 143   };
 144
 145 typedef struct value *value_ptr;
 146
 147 #define VALUE_TYPE(val) (val)->type
 148 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
 149 #define VALUE_LAZY(val) (val)->lazy
 150 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
 151    the gdb buffer used to hold a copy of the contents of the lval.
 152    VALUE_CONTENTS is used when the contents of the buffer are needed --
 153    it uses value_fetch_lazy() to load the buffer from the process being
 154    debugged if it hasn't already been loaded.  VALUE_CONTENTS_RAW is
 155    used when data is being stored into the buffer, or when it is
 156    certain that the contents of the buffer are valid.
 157    Note: The contents pointer is adjusted by the offset required to
 158    get to the real subobject, if the value happens to represent
 159    something embedded in a larger run-time object. */
 160
 161 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
 162 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
 163                              VALUE_CONTENTS_RAW(val))
 164
 165 /* The ALL variants of the above two macros do not adjust the returned
 166    pointer by the embedded_offset value. */
 167
 168 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
 169 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
 170                                  VALUE_CONTENTS_ALL_RAW(val))
 171
 172
 173 extern int value_fetch_lazy PARAMS ((value_ptr val));
 174
 175 #define VALUE_LVAL(val) (val)->lval
 176 #define VALUE_ADDRESS(val) (val)->location.address
 177 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
 178 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
 179 #define VALUE_FRAME(val) ((val)->frame_addr)
 180 #define VALUE_OFFSET(val) (val)->offset
 181 #define VALUE_BITSIZE(val) (val)->bitsize
 182 #define VALUE_BITPOS(val) (val)->bitpos
 183 #define VALUE_NEXT(val) (val)->next
 184 #define VALUE_REGNO(val) (val)->regno
 185 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
 186 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
 187 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
 188 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
 189
 190 /* Convert a REF to the object referenced. */
 191
 192 #define COERCE_REF(arg)    \
 193 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
 194      if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)               \
 195          arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),    \
 196                               unpack_long (VALUE_TYPE (arg),            \
 197                                            VALUE_CONTENTS (arg)),       \
 198                               VALUE_BFD_SECTION (arg));                 \
 199     } while (0)
 200
 201 /* If ARG is an array, convert it to a pointer.
 202    If ARG is an enum, convert it to an integer.
 203    If ARG is a function, convert it to a function pointer.
 204
 205    References are dereferenced.  */
 206
 207 #define COERCE_ARRAY(arg)    \
 208 do { COERCE_REF(arg);                                                   \
 209   if (current_language->c_style_arrays                                  \
 210       && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)               \
 211     arg = value_coerce_array (arg);                                     \
 212   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 213     arg = value_coerce_function (arg);                                  \
 214 } while (0)
 215
 216 #define COERCE_NUMBER(arg)  \
 217   do { COERCE_ARRAY(arg);  COERCE_ENUM(arg); } while (0)
 218
 219 #define COERCE_VARYING_ARRAY(arg, real_arg_type)        \
 220 { if (chill_varying_type (real_arg_type))  \
 221     arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }
 222
 223 /* If ARG is an enum, convert it to an integer.  */
 224
 225 #define COERCE_ENUM(arg)   { \
 226   if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM)   \
 227     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 228 }
 229
 230 /* Internal variables (variables for convenience of use of debugger)
 231    are recorded as a chain of these structures.  */
 232
 233 struct internalvar
 234 {
 235   struct internalvar *next;
 236   char *name;
 237   value_ptr value;
 238 };
 239
 240 /* Pointer to member function.  Depends on compiler implementation. */
 241
 242 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 243 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 244 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 245
 246 \f
 247 #include "symtab.h"
 248 #include "gdbtypes.h"
 249 #include "expression.h"
 250
 251 #ifdef __STDC__
 252 struct frame_info;
 253 struct fn_field;
 254 #endif
 255
 256 extern void
 257 print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));
 258
 259 extern LONGEST value_as_long PARAMS ((value_ptr val));
 260
 261 extern DOUBLEST value_as_double PARAMS ((value_ptr val));
 262
 263 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 264
 265 extern LONGEST unpack_long PARAMS ((struct type *type, char *valaddr));
 266
 267 extern DOUBLEST unpack_double PARAMS ((struct type *type, char *valaddr,
 268                                        int *invp));
 269
 270 extern CORE_ADDR unpack_pointer PARAMS ((struct type *type, char *valaddr));
 271
 272 extern LONGEST unpack_field_as_long PARAMS ((struct type *type, char *valaddr,
 273                                              int fieldno));
 274
 275 extern value_ptr value_from_longest PARAMS ((struct type *type, LONGEST num));
 276
 277 extern value_ptr value_from_double PARAMS ((struct type *type, DOUBLEST num));
 278
 279 extern value_ptr value_at PARAMS ((struct type *type, CORE_ADDR addr, asection *sect));
 280
 281 extern value_ptr value_at_lazy PARAMS ((struct type *type, CORE_ADDR addr, asection *sect));
 282
 283 extern value_ptr value_from_register PARAMS ((struct type *type, int regnum,
 284                                           struct frame_info * frame));
 285
 286 extern value_ptr value_of_variable PARAMS ((struct symbol *var,
 287                                             struct block *b));
 288
 289 extern value_ptr value_of_register PARAMS ((int regnum));
 290
 291 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 292
 293 extern value_ptr read_var_value PARAMS ((struct symbol *var,
 294                                          struct frame_info *frame));
 295
 296 extern value_ptr locate_var_value PARAMS ((struct symbol *var,
 297                                        struct frame_info *frame));
 298
 299 extern value_ptr allocate_value PARAMS ((struct type *type));
 300
 301 extern value_ptr allocate_repeat_value PARAMS ((struct type *type, int count));
 302
 303 extern value_ptr value_mark PARAMS ((void));
 304
 305 extern void value_free_to_mark PARAMS ((value_ptr mark));
 306
 307 extern value_ptr value_string PARAMS ((char *ptr, int len));
 308 extern value_ptr value_bitstring PARAMS ((char *ptr, int len));
 309
 310 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 311                                       value_ptr *elemvec));
 312
 313 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 314
 315 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 316                                       enum exp_opcode op));
 317
 318 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 319
 320 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 321
 322 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 323
 324 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 325
 326 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 327
 328 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 329
 330 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 331
 332 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 333
 334 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 335
 336 extern value_ptr value_struct_elt PARAMS ((value_ptr *argp, value_ptr *args,
 337                                            char *name,
 338                                            int *static_memfuncp, char *err));
 339
 340 extern value_ptr value_struct_elt_for_reference PARAMS ((struct type *domain,
 341                                                          int offset,
 342                                                          struct type *curtype,
 343                                                          char *name,
 344                                                          struct type *intype));
 345
 346 extern value_ptr value_static_field PARAMS ((struct type *type, int fieldno));
 347
 348 extern struct fn_field *
 349 value_find_oload_method_list PARAMS ((value_ptr *, char *, int, int *, int *, struct type **, int *));
 350
 351 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 352
 353 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 354                                                 int fieldno,
 355                                                 struct type *arg_type));
 356
 357 extern struct type *
 358 value_rtti_type PARAMS ((value_ptr, int *, int *, int *));
 359
 360 extern struct type *
 361 value_rtti_target_type PARAMS ((value_ptr, int *, int *, int *));
 362
 363 extern value_ptr
 364 value_full_object PARAMS ((value_ptr, struct type *, int, int, int));
 365
 366 extern value_ptr value_cast PARAMS ((struct type *type, value_ptr arg2));
 367
 368 extern value_ptr value_zero PARAMS ((struct type *type, enum lval_type lv));
 369
 370 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 371
 372 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 373
 374 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 375                                                  struct type *type));
 376
 377 extern value_ptr value_being_returned PARAMS ((struct type *valtype,
 378                                                char retbuf[REGISTER_BYTES],
 379                                                int struct_return));
 380
 381 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 382
 383 extern int value_bit_index PARAMS ((struct type *type, char *addr, int index));
 384
 385 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 386                                         struct type *value_type, int gcc_p));
 387
 388 extern void set_return_value PARAMS ((value_ptr val));
 389
 390 extern value_ptr evaluate_expression PARAMS ((struct expression *exp));
 391
 392 extern value_ptr evaluate_type PARAMS ((struct expression *exp));
 393
 394 extern value_ptr evaluate_subexp_with_coercion PARAMS ((struct expression *,
 395                                                         int *, enum noside));
 396
 397 extern value_ptr parse_and_eval PARAMS ((char *exp));
 398
 399 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 400
 401 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 402
 403 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 404
 405 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 406
 407 extern value_ptr access_value_history PARAMS ((int num));
 408
 409 extern value_ptr value_of_internalvar PARAMS ((struct internalvar *var));
 410
 411 extern void set_internalvar PARAMS ((struct internalvar *var, value_ptr val));
 412
 413 extern void set_internalvar_component PARAMS ((struct internalvar *var,
 414                                                int offset,
 415                                                int bitpos, int bitsize,
 416                                                value_ptr newvalue));
 417
 418 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 419
 420 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 421
 422 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 423
 424 extern int value_logical_not PARAMS ((value_ptr arg1));
 425
 426 /* C++ */
 427
 428 extern value_ptr value_of_this PARAMS ((int complain));
 429
 430 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 431                                         enum exp_opcode op,
 432                                         enum exp_opcode otherop,
 433                                         enum noside noside));
 434
 435 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op,
 436                                        enum noside noside));
 437
 438 extern value_ptr value_fn_field PARAMS ((value_ptr *arg1p, struct fn_field *f,
 439                                          int j,
 440                                          struct type* type, int offset));
 441
 442 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr *arg1p,
 443                                                  struct fn_field *f, int j,
 444                                                  struct type *type,
 445                                                  int offset));
 446
 447 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 448                                          value_ptr arg1, value_ptr arg2));
 449
 450 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 451
 452 extern int destructor_name_p PARAMS ((const char *name,
 453                                       const struct type *type));
 454
 455 #define value_free(val) free ((PTR)val)
 456
 457 extern void free_all_values PARAMS ((void));
 458
 459 extern void release_value PARAMS ((value_ptr val));
 460
 461 extern int record_latest_value PARAMS ((value_ptr val));
 462
 463 extern void registers_changed PARAMS ((void));
 464
 465 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 466
 467 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 468
 469 extern void
 470 read_register_gen PARAMS ((int regno, char *myaddr));
 471
 472 extern CORE_ADDR
 473 read_register PARAMS ((int regno));
 474
 475 extern CORE_ADDR
 476 read_register_pid PARAMS ((int regno, int pid));
 477
 478 extern void
 479 write_register PARAMS ((int regno, LONGEST val));
 480
 481 extern void
 482 write_register_pid PARAMS ((int regno, LONGEST val, int pid));
 483
 484 extern void
 485 supply_register PARAMS ((int regno, char *val));
 486
 487 extern void
 488 get_saved_register PARAMS ((char *raw_buffer, int *optimized,
 489                             CORE_ADDR *addrp, struct frame_info *frame,
 490                             int regnum, enum lval_type *lval));
 491
 492 extern void
 493 modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 494
 495 extern void
 496 type_print PARAMS ((struct type *type, char *varstring, GDB_FILE *stream,
 497                     int show));
 498
 499 extern char *baseclass_addr PARAMS ((struct type *type, int index,
 500                                      char *valaddr,
 501                                      value_ptr *valuep, int *errp));
 502
 503 extern void
 504 print_longest PARAMS ((GDB_FILE *stream, int format, int use_local,
 505                        LONGEST val));
 506
 507 extern void
 508 print_floating PARAMS ((char *valaddr, struct type *type, GDB_FILE *stream));
 509
 510 extern int value_print PARAMS ((value_ptr val, GDB_FILE *stream, int format,
 511                                 enum val_prettyprint pretty));
 512
 513 extern void
 514 value_print_array_elements PARAMS ((value_ptr val, GDB_FILE* stream,
 515                                     int format, enum val_prettyprint pretty));
 516
 517 extern value_ptr
 518 value_release_to_mark PARAMS ((value_ptr mark));
 519
 520 extern int
 521 val_print PARAMS ((struct type *type, char *valaddr, int embedded_offset, CORE_ADDR address,
 522                    GDB_FILE *stream, int format, int deref_ref,
 523                    int recurse, enum val_prettyprint pretty));
 524
 525 extern int
 526 val_print_string PARAMS ((CORE_ADDR addr, int len, int width, GDB_FILE *stream));
 527
 528 extern void
 529 print_variable_value PARAMS ((struct symbol *var, struct frame_info *frame,
 530                               GDB_FILE *stream));
 531
 532 extern int check_field PARAMS ((value_ptr, const char *));
 533
 534 extern void
 535 c_typedef_print PARAMS ((struct type *type, struct symbol *news, GDB_FILE *stream));
 536
 537 extern char *
 538 internalvar_name PARAMS ((struct internalvar *var));
 539
 540 extern void
 541 clear_value_history PARAMS ((void));
 542
 543 extern void
 544 clear_internalvars PARAMS ((void));
 545
 546 /* From values.c */
 547
 548 extern value_ptr value_copy PARAMS ((value_ptr));
 549
 550 extern int baseclass_offset PARAMS ((struct type *, int, char *, CORE_ADDR));
 551
 552 /* From valops.c */
 553
 554 extern value_ptr varying_to_slice PARAMS ((value_ptr));
 555
 556 extern value_ptr value_slice PARAMS ((value_ptr, int, int));
 557
 558 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 559
 560 extern value_ptr value_literal_complex PARAMS ((value_ptr, value_ptr, struct type*));
 561
 562 extern void find_rt_vbase_offset PARAMS ((struct type *, struct type *, char *, int, int *, int *));
 563
 564 extern value_ptr find_function_in_inferior PARAMS ((char *));
 565
 566 extern value_ptr value_allocate_space_in_inferior PARAMS ((int));
 567
 568 #endif  /* !defined (VALUE_H) */