gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2    Copyright 1986, 1987, 1989, 1992, 1993, 1994, 1995 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 (current_language->c_style_arrays                                  \
 190       && (VALUE_REPEATED (arg)                                          \
 191           || TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY))          \
 192     arg = value_coerce_array (arg);                                     \
 193   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 194     arg = value_coerce_function (arg);                                  \
 195   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 196     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 197 }
 198
 199 #define COERCE_VARYING_ARRAY(arg)       \
 200 { if (chill_varying_type (VALUE_TYPE (arg))) arg = varying_to_slice (arg); }
 201
 202 /* If ARG is an enum, convert it to an integer.  */
 203
 204 #define COERCE_ENUM(arg)    \
 205 { COERCE_REF (arg); \
 206   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 207     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 208 }
 209
 210 /* Internal variables (variables for convenience of use of debugger)
 211    are recorded as a chain of these structures.  */
 212
 213 struct internalvar
 214 {
 215   struct internalvar *next;
 216   char *name;
 217   value_ptr value;
 218 };
 219
 220 /* Pointer to member function.  Depends on compiler implementation. */
 221
 222 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 223 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 224 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 225
 226 \f
 227 #include "symtab.h"
 228 #include "gdbtypes.h"
 229 #include "expression.h"
 230
 231 #ifdef __STDC__
 232 struct frame_info;
 233 struct fn_field;
 234 #endif
 235
 236 extern void
 237 print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));
 238
 239 extern LONGEST value_as_long PARAMS ((value_ptr val));
 240
 241 extern double value_as_double PARAMS ((value_ptr val));
 242
 243 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 244
 245 extern LONGEST unpack_long PARAMS ((struct type *type, char *valaddr));
 246
 247 extern double unpack_double PARAMS ((struct type *type, char *valaddr,
 248                                      int *invp));
 249
 250 extern CORE_ADDR unpack_pointer PARAMS ((struct type *type, char *valaddr));
 251
 252 extern LONGEST unpack_field_as_long PARAMS ((struct type *type, char *valaddr,
 253                                              int fieldno));
 254
 255 extern value_ptr value_from_longest PARAMS ((struct type *type, LONGEST num));
 256
 257 extern value_ptr value_from_double PARAMS ((struct type *type, double num));
 258
 259 extern value_ptr value_at PARAMS ((struct type *type, CORE_ADDR addr));
 260
 261 extern value_ptr value_at_lazy PARAMS ((struct type *type, CORE_ADDR addr));
 262
 263 extern value_ptr value_from_register PARAMS ((struct type *type, int regnum,
 264                                           struct frame_info * frame));
 265
 266 extern value_ptr value_of_variable PARAMS ((struct symbol *var,
 267                                             struct block *b));
 268
 269 extern value_ptr value_of_register PARAMS ((int regnum));
 270
 271 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 272
 273 extern value_ptr read_var_value PARAMS ((struct symbol *var,
 274                                          struct frame_info *frame));
 275
 276 extern value_ptr locate_var_value PARAMS ((struct symbol *var,
 277                                        struct frame_info *frame));
 278
 279 extern value_ptr allocate_value PARAMS ((struct type *type));
 280
 281 extern value_ptr allocate_repeat_value PARAMS ((struct type *type, int count));
 282
 283 extern value_ptr value_mark PARAMS ((void));
 284
 285 extern void value_free_to_mark PARAMS ((value_ptr mark));
 286
 287 extern value_ptr value_string PARAMS ((char *ptr, int len));
 288 extern value_ptr value_bitstring PARAMS ((char *ptr, int len));
 289
 290 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 291                                       value_ptr *elemvec));
 292
 293 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 294
 295 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 296                                       enum exp_opcode op));
 297
 298 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 299
 300 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 301
 302 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 303
 304 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 305
 306 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 307
 308 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 309
 310 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 311
 312 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 313
 314 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 315
 316 extern value_ptr value_struct_elt PARAMS ((value_ptr *argp, value_ptr *args,
 317                                            char *name,
 318                                            int *static_memfuncp, char *err));
 319
 320 extern value_ptr value_struct_elt_for_reference PARAMS ((struct type *domain,
 321                                                          int offset,
 322                                                          struct type *curtype,
 323                                                          char *name,
 324                                                          struct type *intype));
 325
 326 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 327
 328 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 329                                                 int fieldno,
 330                                                 struct type *arg_type));
 331
 332 extern value_ptr value_cast PARAMS ((struct type *type, value_ptr arg2));
 333
 334 extern value_ptr value_zero PARAMS ((struct type *type, enum lval_type lv));
 335
 336 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 337
 338 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 339
 340 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 341                                                  struct type *type));
 342
 343 extern value_ptr value_being_returned PARAMS ((struct type *valtype,
 344                                                char retbuf[REGISTER_BYTES],
 345                                                int struct_return));
 346
 347 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 348
 349 extern int value_bit_index PARAMS ((struct type *type, char *addr, int index));
 350
 351 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 352                                         struct type *value_type, int gcc_p));
 353
 354 extern void set_return_value PARAMS ((value_ptr val));
 355
 356 extern value_ptr evaluate_expression PARAMS ((struct expression *exp));
 357
 358 extern value_ptr evaluate_type PARAMS ((struct expression *exp));
 359
 360 extern value_ptr parse_and_eval PARAMS ((char *exp));
 361
 362 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 363
 364 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 365
 366 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 367
 368 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 369
 370 extern value_ptr access_value_history PARAMS ((int num));
 371
 372 extern value_ptr value_of_internalvar PARAMS ((struct internalvar *var));
 373
 374 extern void set_internalvar PARAMS ((struct internalvar *var, value_ptr val));
 375
 376 extern void set_internalvar_component PARAMS ((struct internalvar *var,
 377                                                int offset,
 378                                                int bitpos, int bitsize,
 379                                                value_ptr newvalue));
 380
 381 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 382
 383 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 384
 385 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 386
 387 extern int value_logical_not PARAMS ((value_ptr arg1));
 388
 389 /* C++ */
 390
 391 extern value_ptr value_of_this PARAMS ((int complain));
 392
 393 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 394                                         enum exp_opcode op,
 395                                         enum exp_opcode otherop));
 396
 397 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op));
 398
 399 extern value_ptr value_fn_field PARAMS ((value_ptr *arg1p, struct fn_field *f,
 400                                          int j,
 401                                          struct type* type, int offset));
 402
 403 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr *arg1p,
 404                                                  struct fn_field *f, int j,
 405                                                  struct type *type,
 406                                                  int offset));
 407
 408 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 409                                          value_ptr arg1, value_ptr arg2));
 410
 411 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 412
 413 extern int destructor_name_p PARAMS ((const char *name,
 414                                       const struct type *type));
 415
 416 #define value_free(val) free ((PTR)val)
 417
 418 extern void free_all_values PARAMS ((void));
 419
 420 extern void release_value PARAMS ((value_ptr val));
 421
 422 extern int record_latest_value PARAMS ((value_ptr val));
 423
 424 extern void registers_changed PARAMS ((void));
 425
 426 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 427
 428 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 429
 430 extern void
 431 read_register_gen PARAMS ((int regno, char *myaddr));
 432
 433 extern CORE_ADDR
 434 read_register PARAMS ((int regno));
 435
 436 extern void
 437 write_register PARAMS ((int regno, LONGEST val));
 438
 439 extern void
 440 supply_register PARAMS ((int regno, char *val));
 441
 442 extern void
 443 get_saved_register PARAMS ((char *raw_buffer, int *optimized,
 444                             CORE_ADDR *addrp, struct frame_info *frame,
 445                             int regnum, enum lval_type *lval));
 446
 447 extern void
 448 modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 449
 450 extern void
 451 type_print PARAMS ((struct type *type, char *varstring, GDB_FILE *stream,
 452                     int show));
 453
 454 extern char *baseclass_addr PARAMS ((struct type *type, int index,
 455                                      char *valaddr,
 456                                      value_ptr *valuep, int *errp));
 457
 458 extern void
 459 print_longest PARAMS ((GDB_FILE *stream, int format, int use_local,
 460                        LONGEST val));
 461
 462 extern void
 463 print_floating PARAMS ((char *valaddr, struct type *type, GDB_FILE *stream));
 464
 465 extern int value_print PARAMS ((value_ptr val, GDB_FILE *stream, int format,
 466                                 enum val_prettyprint pretty));
 467
 468 extern void
 469 value_print_array_elements PARAMS ((value_ptr val, GDB_FILE* stream,
 470                                     int format, enum val_prettyprint pretty));
 471
 472 extern value_ptr
 473 value_release_to_mark PARAMS ((value_ptr mark));
 474
 475 extern int
 476 val_print PARAMS ((struct type *type, char *valaddr, CORE_ADDR address,
 477                    GDB_FILE *stream, int format, int deref_ref,
 478                    int recurse, enum val_prettyprint pretty));
 479
 480 extern int
 481 val_print_string PARAMS ((CORE_ADDR addr, unsigned int len, GDB_FILE *stream));
 482
 483 extern void
 484 print_variable_value PARAMS ((struct symbol *var, struct frame_info *frame,
 485                               GDB_FILE *stream));
 486
 487 extern value_ptr value_arg_coerce PARAMS ((value_ptr));
 488
 489 extern int check_field PARAMS ((value_ptr, const char *));
 490
 491 extern void
 492 c_typedef_print PARAMS ((struct type *type, struct symbol *news, GDB_FILE *stream));
 493
 494 extern char *
 495 internalvar_name PARAMS ((struct internalvar *var));
 496
 497 extern void
 498 clear_value_history PARAMS ((void));
 499
 500 extern void
 501 clear_internalvars PARAMS ((void));
 502
 503 /* From values.c */
 504
 505 extern value_ptr value_copy PARAMS ((value_ptr));
 506
 507 extern int baseclass_offset PARAMS ((struct type *, int, value_ptr, int));
 508
 509 /* From valops.c */
 510
 511 extern value_ptr varying_to_slice PARAMS ((value_ptr));
 512
 513 extern value_ptr value_slice PARAMS ((value_ptr, int, int));
 514
 515 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 516
 517 extern value_ptr f77_value_literal_complex PARAMS ((value_ptr, value_ptr, int));
 518
 519 extern value_ptr f77_value_literal_string PARAMS ((int, int, value_ptr *));
 520
 521 extern value_ptr f77_value_substring PARAMS ((value_ptr, int, int));
 522
 523 #endif  /* !defined (VALUE_H) */