gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2    Copyright 1986, 1987, 1989, 1992, 1993, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #if !defined (VALUE_H)
  21 #define VALUE_H 1
  22
  23 /*
  24  * The structure which defines the type of a value.  It should never
  25  * be possible for a program lval value to survive over a call to the inferior
  26  * (ie to be put into the history list or an internal variable).
  27  */
  28 enum lval_type {
  29   /* Not an lval.  */
  30   not_lval,
  31   /* In memory.  Could be a saved register.  */
  32   lval_memory,
  33   /* In a register.  */
  34   lval_register,
  35   /* In a gdb internal variable.  */
  36   lval_internalvar,
  37   /* Part of a gdb internal variable (structure field).  */
  38   lval_internalvar_component,
  39   /* In a register series in a frame not the current one, which may have been
  40      partially saved or saved in different places (otherwise would be
  41      lval_register or lval_memory).  */
  42   lval_reg_frame_relative
  43 };
  44
  45 struct value
  46   {
  47     /* Type of value; either not an lval, or one of the various
  48        different possible kinds of lval.  */
  49     enum lval_type lval;
  50     /* Is it modifiable?  Only relevant if lval != not_lval.  */
  51     int modifiable;
  52     /* Location of value (if lval).  */
  53     union
  54       {
  55         /* Address in inferior or byte of registers structure.  */
  56         CORE_ADDR address;
  57         /* Pointer to internal variable.  */
  58         struct internalvar *internalvar;
  59         /* Number of register.  Only used with
  60            lval_reg_frame_relative.  */
  61         int regnum;
  62       } location;
  63     /* Describes offset of a value within lval a structure in bytes.  */
  64     int offset;
  65     /* Only used for bitfields; number of bits contained in them.  */
  66     int bitsize;
  67     /* Only used for bitfields; position of start of field.
  68        For BITS_BIG_ENDIAN=0 targets, it is the position of the LSB.
  69        For BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
  70     int bitpos;
  71     /* Frame value is relative to.  In practice, this address is only
  72        used if the value is stored in several registers in other than
  73        the current frame, and these registers have not all been saved
  74        at the same place in memory.  This will be described in the
  75        lval enum above as "lval_reg_frame_relative".  */
  76     CORE_ADDR frame_addr;
  77     /* Type of the value.  */
  78     struct type *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       CORE_ADDR memaddr;
  88       char *myaddr;
  89     } substring_addr;
  90
  91     /* If an lval is forced to repeat, a new value is created with
  92        these fields set.  The new value is not an lval.  */
  93     short repeated;
  94     short repetitions;
  95     /* Register number if the value is from a register.  Is not kept
  96        if you take a field of a structure that is stored in a
  97        register.  Shouldn't it be?  */
  98     short regno;
  99     /* If zero, contents of this value are in the contents field.
 100        If nonzero, contents are in inferior memory at address
 101        in the location.address field plus the offset field
 102        (and the lval field should be lval_memory).  */
 103     char lazy;
 104     /* If nonzero, this is the value of a variable which does not
 105        actually exist in the program.  */
 106     char optimized_out;
 107     /* Actual contents of the value.  For use of this value; setting
 108        it uses the stuff above.  Not valid if lazy is nonzero.
 109        Target byte-order.  We force it to be aligned properly for any
 110        possible value.  */
 111     union {
 112       long contents[1];
 113       double force_double_align;
 114       LONGEST force_longlong_align;
 115       char *literal_data;
 116     } aligner;
 117
 118   };
 119
 120 typedef struct value *value_ptr;
 121
 122 #define VALUE_TYPE(val) (val)->type
 123 #define VALUE_LAZY(val) (val)->lazy
 124 /* VALUE_CONTENTS and VALUE_CONTENTS_RAW both return the address of
 125    the gdb buffer used to hold a copy of the contents of the lval.
 126    VALUE_CONTENTS is used when the contents of the buffer are needed --
 127    it uses value_fetch_lazy() to load the buffer from the process being
 128    debugged if it hasn't already been loaded.  VALUE_CONTENTS_RAW is
 129    used when data is being stored into the buffer, or when it is
 130    certain that the contents of the buffer are valid.  */
 131 #define VALUE_CONTENTS_RAW(val) ((char *) (val)->aligner.contents)
 132 #define VALUE_CONTENTS(val) ((void)(VALUE_LAZY(val) && value_fetch_lazy(val)),\
 133                              VALUE_CONTENTS_RAW(val))
 134 extern int value_fetch_lazy PARAMS ((value_ptr val));
 135
 136 #define VALUE_LVAL(val) (val)->lval
 137 #define VALUE_ADDRESS(val) (val)->location.address
 138 #define VALUE_INTERNALVAR(val) (val)->location.internalvar
 139 #define VALUE_FRAME_REGNUM(val) ((val)->location.regnum)
 140 #define VALUE_FRAME(val) ((val)->frame_addr)
 141 #define VALUE_OFFSET(val) (val)->offset
 142 #define VALUE_BITSIZE(val) (val)->bitsize
 143 #define VALUE_BITPOS(val) (val)->bitpos
 144 #define VALUE_NEXT(val) (val)->next
 145 #define VALUE_REPEATED(val) (val)->repeated
 146 #define VALUE_REPETITIONS(val) (val)->repetitions
 147 #define VALUE_REGNO(val) (val)->regno
 148 #define VALUE_OPTIMIZED_OUT(val) ((val)->optimized_out)
 149
 150 /* This is probably not the right thing to do for in-gdb arrays.  FIXME */
 151 /* Overload the contents field to store literal data for
 152    arrays.  */
 153
 154 #define VALUE_LITERAL_DATA(val)  ((val)->aligner.literal_data)
 155
 156 /* Pointer to
 157    the base substring, for F77 string substring operators.
 158    We use this ONLY when doing operations of the form
 159
 160    FOO= 'hello'
 161    FOO(2:4) = 'foo'
 162
 163    In the above case VALUE_SUBSTRING_* would point to
 164    FOO(2) in the original FOO string.
 165
 166    Depending on whether the base object is allocated in the
 167    inferior or the superior process, use VALUE_SUBSTRING_MYADDR or
 168    VALUE_SUBSTRING_MEMADDR.  */
 169
 170 #define VALUE_SUBSTRING_MEMADDR(val) (val)->substring_addr.memaddr
 171 #define VALUE_SUBSTRING_MYADDR(val) (val)->substring_addr.myaddr
 172
 173 /* Convert a REF to the object referenced. */
 174
 175 #define COERCE_REF(arg)    \
 176 { if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF)                    \
 177     arg = value_at_lazy (TYPE_TARGET_TYPE (VALUE_TYPE (arg)),           \
 178                          unpack_long (VALUE_TYPE (arg),                 \
 179                                       VALUE_CONTENTS (arg)));}
 180
 181 /* If ARG is an array, convert it to a pointer.
 182    If ARG is an enum, convert it to an integer.
 183    If ARG is a function, convert it to a function pointer.
 184
 185    References are dereferenced.  */
 186
 187 #define COERCE_ARRAY(arg)    \
 188 { COERCE_REF(arg);                                                      \
 189   if (VALUE_REPEATED (arg)                                              \
 190       || TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)               \
 191     arg = value_coerce_array (arg);                                     \
 192   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 193     arg = value_coerce_function (arg);                                  \
 194   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 195     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 196 }
 197
 198 /* If ARG is an enum, convert it to an integer.  */
 199
 200 #define COERCE_ENUM(arg)    \
 201 { COERCE_REF (arg); \
 202   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 203     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 204 }
 205
 206 /* Internal variables (variables for convenience of use of debugger)
 207    are recorded as a chain of these structures.  */
 208
 209 struct internalvar
 210 {
 211   struct internalvar *next;
 212   char *name;
 213   value_ptr value;
 214 };
 215
 216 /* Pointer to member function.  Depends on compiler implementation. */
 217
 218 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 219 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 220 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 221
 222 \f
 223 #include "symtab.h"
 224 #include "gdbtypes.h"
 225 #include "expression.h"
 226
 227 #ifdef __STDC__
 228 struct frame_info;
 229 struct fn_field;
 230 #endif
 231
 232 extern void
 233 print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));
 234
 235 extern LONGEST value_as_long PARAMS ((value_ptr val));
 236
 237 extern double value_as_double PARAMS ((value_ptr val));
 238
 239 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 240
 241 extern LONGEST unpack_long PARAMS ((struct type *type, char *valaddr));
 242
 243 extern double unpack_double PARAMS ((struct type *type, char *valaddr,
 244                                      int *invp));
 245
 246 extern CORE_ADDR unpack_pointer PARAMS ((struct type *type, char *valaddr));
 247
 248 extern LONGEST unpack_field_as_long PARAMS ((struct type *type, char *valaddr,
 249                                              int fieldno));
 250
 251 extern value_ptr value_from_longest PARAMS ((struct type *type, LONGEST num));
 252
 253 extern value_ptr value_from_double PARAMS ((struct type *type, double num));
 254
 255 extern value_ptr value_at PARAMS ((struct type *type, CORE_ADDR addr));
 256
 257 extern value_ptr value_at_lazy PARAMS ((struct type *type, CORE_ADDR addr));
 258
 259 extern value_ptr value_from_register PARAMS ((struct type *type, int regnum,
 260                                           struct frame_info * frame));
 261
 262 extern value_ptr value_of_variable PARAMS ((struct symbol *var,
 263                                             struct block *b));
 264
 265 extern value_ptr value_of_register PARAMS ((int regnum));
 266
 267 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 268
 269 extern value_ptr read_var_value PARAMS ((struct symbol *var,
 270                                          struct frame_info *frame));
 271
 272 extern value_ptr locate_var_value PARAMS ((struct symbol *var,
 273                                        struct frame_info *frame));
 274
 275 extern value_ptr allocate_value PARAMS ((struct type *type));
 276
 277 extern value_ptr allocate_repeat_value PARAMS ((struct type *type, int count));
 278
 279 extern value_ptr value_mark PARAMS ((void));
 280
 281 extern void value_free_to_mark PARAMS ((value_ptr mark));
 282
 283 extern value_ptr value_string PARAMS ((char *ptr, int len));
 284
 285 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 286                                       value_ptr *elemvec));
 287
 288 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 289
 290 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 291                                       enum exp_opcode op));
 292
 293 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 294
 295 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 296
 297 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 298
 299 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 300
 301 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 302
 303 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 304
 305 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 306
 307 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 308
 309 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 310
 311 extern value_ptr value_struct_elt PARAMS ((value_ptr *argp, value_ptr *args,
 312                                            char *name,
 313                                            int *static_memfuncp, char *err));
 314
 315 extern value_ptr value_struct_elt_for_reference PARAMS ((struct type *domain,
 316                                                          int offset,
 317                                                          struct type *curtype,
 318                                                          char *name,
 319                                                          struct type *intype));
 320
 321 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 322
 323 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 324                                                 int fieldno,
 325                                                 struct type *arg_type));
 326
 327 extern value_ptr value_cast PARAMS ((struct type *type, value_ptr arg2));
 328
 329 extern value_ptr value_zero PARAMS ((struct type *type, enum lval_type lv));
 330
 331 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 332
 333 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 334
 335 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 336                                                  struct type *type));
 337
 338 extern value_ptr value_being_returned PARAMS ((struct type *valtype,
 339                                                char retbuf[REGISTER_BYTES],
 340                                                int struct_return));
 341
 342 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 343
 344 extern int value_bit_index PARAMS ((struct type *type, char *addr, int index));
 345
 346 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 347                                         struct type *value_type, int gcc_p));
 348
 349 extern void set_return_value PARAMS ((value_ptr val));
 350
 351 extern value_ptr evaluate_expression PARAMS ((struct expression *exp));
 352
 353 extern value_ptr evaluate_type PARAMS ((struct expression *exp));
 354
 355 extern value_ptr parse_and_eval PARAMS ((char *exp));
 356
 357 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 358
 359 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 360
 361 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 362
 363 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 364
 365 extern value_ptr access_value_history PARAMS ((int num));
 366
 367 extern value_ptr value_of_internalvar PARAMS ((struct internalvar *var));
 368
 369 extern void set_internalvar PARAMS ((struct internalvar *var, value_ptr val));
 370
 371 extern void set_internalvar_component PARAMS ((struct internalvar *var,
 372                                                int offset,
 373                                                int bitpos, int bitsize,
 374                                                value_ptr newvalue));
 375
 376 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 377
 378 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 379
 380 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 381
 382 extern int value_logical_not PARAMS ((value_ptr arg1));
 383
 384 /* C++ */
 385
 386 extern value_ptr value_of_this PARAMS ((int complain));
 387
 388 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 389                                         enum exp_opcode op,
 390                                         enum exp_opcode otherop));
 391
 392 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op));
 393
 394 extern value_ptr value_fn_field PARAMS ((value_ptr *arg1p, struct fn_field *f,
 395                                          int j,
 396                                          struct type* type, int offset));
 397
 398 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr *arg1p,
 399                                                  struct fn_field *f, int j,
 400                                                  struct type *type,
 401                                                  int offset));
 402
 403 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 404                                          value_ptr arg1, value_ptr arg2));
 405
 406 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 407
 408 extern int destructor_name_p PARAMS ((const char *name,
 409                                       const struct type *type));
 410
 411 #define value_free(val) free ((PTR)val)
 412
 413 extern void free_all_values PARAMS ((void));
 414
 415 extern void release_value PARAMS ((value_ptr val));
 416
 417 extern int record_latest_value PARAMS ((value_ptr val));
 418
 419 extern void registers_changed PARAMS ((void));
 420
 421 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 422
 423 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 424
 425 extern void
 426 read_register_gen PARAMS ((int regno, char *myaddr));
 427
 428 extern CORE_ADDR
 429 read_register PARAMS ((int regno));
 430
 431 extern void
 432 write_register PARAMS ((int regno, LONGEST val));
 433
 434 extern void
 435 supply_register PARAMS ((int regno, char *val));
 436
 437 extern void
 438 get_saved_register PARAMS ((char *raw_buffer, int *optimized,
 439                             CORE_ADDR *addrp, struct frame_info *frame,
 440                             int regnum, enum lval_type *lval));
 441
 442 extern void
 443 modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 444
 445 extern void
 446 type_print PARAMS ((struct type *type, char *varstring, GDB_FILE *stream,
 447                     int show));
 448
 449 extern char *baseclass_addr PARAMS ((struct type *type, int index,
 450                                      char *valaddr,
 451                                      value_ptr *valuep, int *errp));
 452
 453 extern void
 454 print_longest PARAMS ((GDB_FILE *stream, int format, int use_local,
 455                        LONGEST val));
 456
 457 extern void
 458 print_floating PARAMS ((char *valaddr, struct type *type, GDB_FILE *stream));
 459
 460 extern int value_print PARAMS ((value_ptr val, GDB_FILE *stream, int format,
 461                                 enum val_prettyprint pretty));
 462
 463 extern void
 464 value_print_array_elements PARAMS ((value_ptr val, GDB_FILE* stream,
 465                                     int format, enum val_prettyprint pretty));
 466
 467 extern value_ptr
 468 value_release_to_mark PARAMS ((value_ptr mark));
 469
 470 extern int
 471 val_print PARAMS ((struct type *type, char *valaddr, CORE_ADDR address,
 472                    GDB_FILE *stream, int format, int deref_ref,
 473                    int recurse, enum val_prettyprint pretty));
 474
 475 extern int
 476 val_print_string PARAMS ((CORE_ADDR addr, unsigned int len, GDB_FILE *stream));
 477
 478 extern void
 479 print_variable_value PARAMS ((struct symbol *var, struct frame_info *frame,
 480                               GDB_FILE *stream));
 481
 482 extern value_ptr value_arg_coerce PARAMS ((value_ptr));
 483
 484 extern int check_field PARAMS ((value_ptr, const char *));
 485
 486 extern void
 487 c_typedef_print PARAMS ((struct type *type, struct symbol *new, GDB_FILE *stream));
 488
 489 extern char *
 490 internalvar_name PARAMS ((struct internalvar *var));
 491
 492 extern void
 493 clear_value_history PARAMS ((void));
 494
 495 extern void
 496 clear_internalvars PARAMS ((void));
 497
 498 /* From values.c */
 499
 500 extern value_ptr value_copy PARAMS ((value_ptr));
 501
 502 extern int baseclass_offset PARAMS ((struct type *, int, value_ptr, int));
 503
 504 /* From valops.c */
 505
 506 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 507
 508 extern value_ptr f77_value_literal_complex PARAMS ((value_ptr, value_ptr, int));
 509
 510 extern value_ptr f77_value_literal_string PARAMS ((int, int, value_ptr *));
 511
 512 extern value_ptr f77_value_substring PARAMS ((value_ptr, int, int));
 513
 514 #endif  /* !defined (VALUE_H) */