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,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #if !defined (VALUE_H)
  23 #define VALUE_H 1
  24
  25 /*
  26  * The structure which defines the type of a value.  It should never
  27  * be possible for a program lval value to survive over a call to the inferior
  28  * (ie to be put into the history list or an internal variable).
  29  */
  30
  31 struct value
  32   {
  33     /* Type of value; either not an lval, or one of the various
  34        different possible kinds of lval.  */
  35     enum lval_type lval;
  36     /* Is it modifiable?  Only relevant if lval != not_lval.  */
  37     int modifiable;
  38     /* Location of value (if lval).  */
  39     union
  40       {
  41         /* If lval == lval_memory, this is the address in the inferior.
  42            If lval == lval_register, this is the byte offset into the
  43            registers structure.  */
  44         CORE_ADDR address;
  45         /* Pointer to internal variable.  */
  46         struct internalvar *internalvar;
  47         /* Number of register.  Only used with
  48            lval_reg_frame_relative.  */
  49         int regnum;
  50       }
  51     location;
  52     /* Describes offset of a value within lval of a structure in bytes.
  53        If lval == lval_memory, this is an offset to the address.
  54        If lval == lval_register, this is a further offset from
  55           location.address within the registers structure.
  56        Note also the member embedded_offset below.  */
  57     int offset;
  58     /* Only used for bitfields; number of bits contained in them.  */
  59     int bitsize;
  60     /* Only used for bitfields; position of start of field.
  61        For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
  62        For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
  63     int bitpos;
  64     /* Frame value is relative to.  In practice, this address is only
  65        used if the value is stored in several registers in other than
  66        the current frame, and these registers have not all been saved
  67        at the same place in memory.  This will be described in the
  68        lval enum above as "lval_reg_frame_relative".  */
  69     CORE_ADDR frame_addr;
  70     /* Type of the value.  */
  71     struct type *type;
  72     /* Type of the enclosing object if this is an embedded subobject.
  73        The member embedded_offset gives the real position of the subobject
  74        if type is not the same as enclosing_type.
  75
  76        If the type field is a pointer type, then enclosing_type is
  77        a pointer type pointing to the real (enclosing) type of the target
  78        object. */
  79     struct type *enclosing_type;
  80     /* Values are stored in a chain, so that they can be deleted
  81        easily over calls to the inferior.  Values assigned to internal
  82        variables or put into the value history are taken off this
  83        list.  */
  84     struct value *next;
  85
  86     /* ??? When is this used?  */
  87     union
  88       {
  89         CORE_ADDR memaddr;
  90         char *myaddr;
  91       }
  92     substring_addr;
  93
  94     /* Register number if the value is from a register.  Is not kept
  95        if you take a field of a structure that is stored in a
  96        register.  Shouldn't it be?  */
  97     short regno;
  98     /* If zero, contents of this value are in the contents field.
  99        If nonzero, contents are in inferior memory at address
 100        in the location.address field plus the offset field
 101        (and the lval field should be lval_memory).  */
 102     char lazy;
 103     /* If nonzero, this is the value of a variable which does not
 104        actually exist in the program.  */
 105     char optimized_out;
 106     /* If this value represents an object that is embedded inside a
 107        larger object (e.g., a base subobject in C++), this gives the
 108        offset (in bytes) from the start of the contents buffer where
 109        the embedded object begins. This is required because some C++
 110        runtime implementations lay out objects (especially virtual bases
 111        with possibly negative offsets to ancestors).
 112        Note: This may be positive or negative! Also note that this offset
 113        is not used when retrieving contents from target memory; the entire
 114        enclosing object has to be retrieved always, and the offset for
 115        that is given by the member offset above. */
 116     int embedded_offset;
 117     /* If this value represents a pointer to an object that is embedded
 118        in another object, this gives the embedded_offset of the object
 119        that is pointed to. */
 120     int pointed_to_offset;
 121     /* The BFD section associated with this value.  */
 122     asection *bfd_section;
 123     /* Actual contents of the value.  For use of this value; setting
 124        it uses the stuff above.  Not valid if lazy is nonzero.
 125        Target byte-order.  We force it to be aligned properly for any
 126        possible value.  Note that a value therefore extends beyond
 127        what is declared here.  */
 128     union
 129       {
 130         long contents[1];
 131         double force_double_align;
 132         LONGEST force_longlong_align;
 133         char *literal_data;
 134       }
 135     aligner;
 136     /* Do not add any new members here -- contents above will trash them */
 137   };
 138
 139 typedef struct value *value_ptr;
 140
 141 #define VALUE_TYPE(val) (val)->type
 142 #define VALUE_ENCLOSING_TYPE(val) (val)->enclosing_type
 143 #define VALUE_LAZY(val) (val)->lazy
 144 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
 145    the gdb buffer used to hold a copy of the contents of the lval.
 146    VALUE_CONTENTS is used when the contents of the buffer are needed --
 147    it uses value_fetch_lazy() to load the buffer from the process being
 148    debugged if it hasn't already been loaded.  VALUE_CONTENTS_RAW is
 149    used when data is being stored into the buffer, or when it is
 150    certain that the contents of the buffer are valid.
 151    Note: The contents pointer is adjusted by the offset required to
 152    get to the real subobject, if the value happens to represent
 153    something embedded in a larger run-time object. */
 154
 155 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents + (val)->embedded_offset)
 156 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
 157                              VALUE_CONTENTS_RAW(val))
 158
 159 /* The ALL variants of the above two macros do not adjust the returned
 160    pointer by the embedded_offset value. */
 161
 162 #define VALUE_CONTENTS_ALL_RAW(val) ((char *) (val)->aligner.contents)
 163 #define VALUE_CONTENTS_ALL(val) ((void) (VALUE_LAZY(val) && value_fetch_lazy(val)),\
 164                                  VALUE_CONTENTS_ALL_RAW(val))
 165
 166
 167 extern int value_fetch_lazy PARAMS ((value_ptr val));
 168
 169 #define VALUE_LVAL(val) (val)->lval
 170 #define VALUE_ADDRESS(val) (val)->location.address
 171 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
 172 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
 173 #define VALUE_FRAME(val) ((val)->frame_addr)
 174 #define VALUE_OFFSET(val) (val)->offset
 175 #define VALUE_BITSIZE(val) (val)->bitsize
 176 #define VALUE_BITPOS(val) (val)->bitpos
 177 #define VALUE_NEXT(val) (val)->next
 178 #define VALUE_REGNO(val) (val)->regno
 179 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
 180 #define VALUE_EMBEDDED_OFFSET(val) ((val)->embedded_offset)
 181 #define VALUE_POINTED_TO_OFFSET(val) ((val)->pointed_to_offset)
 182 #define VALUE_BFD_SECTION(val) ((val)->bfd_section)
 183
 184 /* Convert a REF to the object referenced. */
 185
 186 #define COERCE_REF(arg)    \
 187 do { struct type *value_type_arg_tmp = check_typedef (VALUE_TYPE (arg));\
 188      if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)               \
 189          arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),    \
 190                               unpack_long (VALUE_TYPE (arg),            \
 191                                            VALUE_CONTENTS (arg)),       \
 192                               VALUE_BFD_SECTION (arg));                 \
 193     } while (0)
 194
 195 /* If ARG is an array, convert it to a pointer.
 196    If ARG is an enum, convert it to an integer.
 197    If ARG is a function, convert it to a function pointer.
 198
 199    References are dereferenced.  */
 200
 201 #define COERCE_ARRAY(arg)    \
 202 do { COERCE_REF(arg);                                                   \
 203   if (current_language->c_style_arrays                                  \
 204       && TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)               \
 205     arg = value_coerce_array (arg);                                     \
 206   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 207     arg = value_coerce_function (arg);                                  \
 208 } while (0)
 209
 210 #define COERCE_NUMBER(arg)  \
 211   do { COERCE_ARRAY(arg);  COERCE_ENUM(arg); } while (0)
 212
 213 #define COERCE_VARYING_ARRAY(arg, real_arg_type)        \
 214 { if (chill_varying_type (real_arg_type))  \
 215     arg = varying_to_slice (arg), real_arg_type = VALUE_TYPE (arg); }
 216
 217 /* If ARG is an enum, convert it to an integer.  */
 218
 219 #define COERCE_ENUM(arg)   { \
 220   if (TYPE_CODE (check_typedef (VALUE_TYPE (arg))) == TYPE_CODE_ENUM)   \
 221     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 222 }
 223
 224 /* Internal variables (variables for convenience of use of debugger)
 225    are recorded as a chain of these structures.  */
 226
 227 struct internalvar
 228   {
 229     struct internalvar *next;
 230     char *name;
 231     value_ptr value;
 232   };
 233
 234 /* Pointer to member function.  Depends on compiler implementation. */
 235
 236 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 237 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 238 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 239 \f
 240
 241 #include "symtab.h"
 242 #include "gdbtypes.h"
 243 #include "expression.h"
 244
 245 struct frame_info;
 246 struct fn_field;
 247
 248 extern void
 249 print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));
 250
 251 extern LONGEST value_as_long PARAMS ((value_ptr val));
 252
 253 extern DOUBLEST value_as_double PARAMS ((value_ptr val));
 254
 255 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 256
 257 extern LONGEST unpack_long PARAMS ((struct type * type, char *valaddr));
 258
 259 extern DOUBLEST unpack_double PARAMS ((struct type * type, char *valaddr,
 260                                        int *invp));
 261
 262 extern CORE_ADDR unpack_pointer PARAMS ((struct type * type, char *valaddr));
 263
 264 extern LONGEST unpack_field_as_long PARAMS ((struct type * type, char *valaddr,
 265                                              int fieldno));
 266
 267 extern value_ptr value_from_longest PARAMS ((struct type * type, LONGEST num));
 268
 269 extern value_ptr value_from_double PARAMS ((struct type * type, DOUBLEST num));
 270
 271 extern value_ptr value_from_string PARAMS ((char *string));
 272
 273 extern value_ptr value_at PARAMS ((struct type * type, CORE_ADDR addr, asection * sect));
 274
 275 extern value_ptr value_at_lazy PARAMS ((struct type * type, CORE_ADDR addr, asection * sect));
 276
 277 extern value_ptr value_from_register PARAMS ((struct type * type, int regnum,
 278                                               struct frame_info * frame));
 279
 280 extern value_ptr value_of_variable PARAMS ((struct symbol * var,
 281                                             struct block * b));
 282
 283 extern value_ptr value_of_register PARAMS ((int regnum));
 284
 285 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 286
 287 extern value_ptr read_var_value PARAMS ((struct symbol * var,
 288                                          struct frame_info * frame));
 289
 290 extern value_ptr locate_var_value PARAMS ((struct symbol * var,
 291                                            struct frame_info * frame));
 292
 293 extern value_ptr allocate_value PARAMS ((struct type * type));
 294
 295 extern value_ptr allocate_repeat_value PARAMS ((struct type * type, int count));
 296
 297 extern value_ptr value_mark PARAMS ((void));
 298
 299 extern void value_free_to_mark PARAMS ((value_ptr mark));
 300
 301 extern value_ptr value_string PARAMS ((char *ptr, int len));
 302 extern value_ptr value_bitstring PARAMS ((char *ptr, int len));
 303
 304 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 305                                       value_ptr * elemvec));
 306
 307 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 308
 309 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 310                                       enum exp_opcode op));
 311
 312 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 313
 314 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 315
 316 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 317
 318 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 319
 320 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 321
 322 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 323
 324 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 325
 326 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 327
 328 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 329
 330 extern value_ptr value_struct_elt PARAMS ((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 PARAMS ((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 PARAMS ((struct type * type, int fieldno));
 341
 342 extern struct fn_field *value_find_oload_method_list PARAMS ((value_ptr *, char *, int, int *, int *, struct type **, int *));
 343
 344 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));
 345
 346 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 347
 348 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 349                                                 int fieldno,
 350                                                 struct type * arg_type));
 351
 352 extern struct type *
 353   value_rtti_type PARAMS ((value_ptr, int *, int *, int *));
 354
 355 extern struct type *
 356   value_rtti_target_type PARAMS ((value_ptr, int *, int *, int *));
 357
 358 extern value_ptr
 359   value_full_object PARAMS ((value_ptr, struct type *, int, int, int));
 360
 361 extern value_ptr value_cast PARAMS ((struct type * type, value_ptr arg2));
 362
 363 extern value_ptr value_zero PARAMS ((struct type * type, enum lval_type lv));
 364
 365 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 366
 367 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 368
 369 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 370                                                  struct type * type));
 371
 372 extern value_ptr value_being_returned PARAMS ((struct type * valtype,
 373                                                char *retbuf,
 374                                                int struct_return));
 375
 376 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 377
 378 extern int value_bit_index PARAMS ((struct type * type, char *addr, int index));
 379
 380 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 381                                       struct type * value_type, int gcc_p));
 382
 383 extern void set_return_value PARAMS ((value_ptr val));
 384
 385 extern value_ptr evaluate_expression PARAMS ((struct expression * exp));
 386
 387 extern value_ptr evaluate_type PARAMS ((struct expression * exp));
 388
 389 extern value_ptr evaluate_subexp_with_coercion PARAMS ((struct expression *,
 390                                                         int *, enum noside));
 391
 392 extern value_ptr parse_and_eval PARAMS ((char *exp));
 393
 394 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 395
 396 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 397
 398 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 399
 400 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 401
 402 extern value_ptr access_value_history PARAMS ((int num));
 403
 404 extern value_ptr value_of_internalvar PARAMS ((struct internalvar * var));
 405
 406 extern void set_internalvar PARAMS ((struct internalvar * var, value_ptr val));
 407
 408 extern void set_internalvar_component PARAMS ((struct internalvar * var,
 409                                                int offset,
 410                                                int bitpos, int bitsize,
 411                                                value_ptr newvalue));
 412
 413 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 414
 415 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 416
 417 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 418
 419 extern int value_logical_not PARAMS ((value_ptr arg1));
 420
 421 /* C++ */
 422
 423 extern value_ptr value_of_this PARAMS ((int complain));
 424
 425 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 426                                         enum exp_opcode op,
 427                                         enum exp_opcode otherop,
 428                                         enum noside noside));
 429
 430 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op,
 431                                        enum noside noside));
 432
 433 extern value_ptr value_fn_field PARAMS ((value_ptr * arg1p, struct fn_field * f,
 434                                          int j,
 435                                          struct type * type, int offset));
 436
 437 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr * arg1p,
 438                                                  struct fn_field * f, int j,
 439                                                  struct type * type,
 440                                                  int offset));
 441
 442 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 443                                          value_ptr arg1, value_ptr arg2));
 444
 445 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 446
 447 extern int destructor_name_p PARAMS ((const char *name,
 448                                       const struct type * type));
 449
 450 #define value_free(val) free ((PTR)val)
 451
 452 extern void free_all_values PARAMS ((void));
 453
 454 extern void release_value PARAMS ((value_ptr val));
 455
 456 extern int record_latest_value PARAMS ((value_ptr val));
 457
 458 extern void registers_changed PARAMS ((void));
 459
 460 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 461
 462 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 463
 464 extern void
 465 read_register_gen PARAMS ((int regno, char *myaddr));
 466
 467 extern CORE_ADDR
 468   read_register PARAMS ((int regno));
 469
 470 extern CORE_ADDR
 471   read_register_pid PARAMS ((int regno, int pid));
 472
 473 extern void
 474 write_register PARAMS ((int regno, LONGEST val));
 475
 476 extern void
 477 write_register_pid PARAMS ((int regno, CORE_ADDR val, int pid));
 478
 479 extern void
 480 supply_register PARAMS ((int regno, char *val));
 481
 482 extern void get_saved_register PARAMS ((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 PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 489
 490 extern void
 491 type_print PARAMS ((struct type * type, char *varstring, GDB_FILE * stream,
 492                     int show));
 493
 494 extern char *baseclass_addr PARAMS ((struct type * type, int index,
 495                                      char *valaddr,
 496                                      value_ptr * valuep, int *errp));
 497
 498 extern void
 499 print_longest PARAMS ((GDB_FILE * stream, int format, int use_local,
 500                        LONGEST val));
 501
 502 extern void
 503 print_floating PARAMS ((char *valaddr, struct type * type, GDB_FILE * stream));
 504
 505 extern int value_print PARAMS ((value_ptr val, GDB_FILE * stream, int format,
 506                                 enum val_prettyprint pretty));
 507
 508 extern void
 509 value_print_array_elements PARAMS ((value_ptr val, GDB_FILE * stream,
 510                                   int format, enum val_prettyprint pretty));
 511
 512 extern value_ptr
 513   value_release_to_mark PARAMS ((value_ptr mark));
 514
 515 extern int
 516 val_print PARAMS ((struct type * type, char *valaddr, int embedded_offset, CORE_ADDR address,
 517                    GDB_FILE * stream, int format, int deref_ref,
 518                    int recurse, enum val_prettyprint pretty));
 519
 520 extern int
 521 val_print_string PARAMS ((CORE_ADDR addr, int len, int width, GDB_FILE * stream));
 522
 523 extern void
 524 print_variable_value PARAMS ((struct symbol * var, struct frame_info * frame,
 525                               GDB_FILE * stream));
 526
 527 extern int check_field PARAMS ((value_ptr, const char *));
 528
 529 extern void
 530 c_typedef_print PARAMS ((struct type * type, struct symbol * news, GDB_FILE * stream));
 531
 532 extern char *
 533   internalvar_name PARAMS ((struct internalvar * var));
 534
 535 extern void
 536 clear_value_history PARAMS ((void));
 537
 538 extern void
 539 clear_internalvars PARAMS ((void));
 540
 541 /* From values.c */
 542
 543 extern value_ptr value_copy PARAMS ((value_ptr));
 544
 545 extern int baseclass_offset PARAMS ((struct type *, int, char *, CORE_ADDR));
 546
 547 /* From valops.c */
 548
 549 extern value_ptr varying_to_slice PARAMS ((value_ptr));
 550
 551 extern value_ptr value_slice PARAMS ((value_ptr, int, int));
 552
 553 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 554
 555 extern value_ptr value_literal_complex PARAMS ((value_ptr, value_ptr, struct type *));
 556
 557 extern void find_rt_vbase_offset PARAMS ((struct type *, struct type *, char *, int, int *, int *));
 558
 559 extern value_ptr find_function_in_inferior PARAMS ((char *));
 560
 561 extern value_ptr value_allocate_space_in_inferior PARAMS ((int));
 562
 563 extern CORE_ADDR default_push_arguments PARAMS ((int nargs, value_ptr * args,
 564                                                  CORE_ADDR sp,
 565                                                  int struct_return,
 566                                                  CORE_ADDR struct_addr));
 567
 568 #endif /* !defined (VALUE_H) */