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