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 /* Convert a REF to the object referenced. */
 151
 152 #define COERCE_REF(arg)    \
 153 { if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_REF)                    \
 154     arg = value_at_lazy (TYPE_TARGET_TYPE (VALUE_TYPE (arg)),           \
 155                          unpack_long (VALUE_TYPE (arg),                 \
 156                                       VALUE_CONTENTS (arg)));}
 157
 158 /* If ARG is an array, convert it to a pointer.
 159    If ARG is an enum, convert it to an integer.
 160    If ARG is a function, convert it to a function pointer.
 161
 162    References are dereferenced.  */
 163
 164 #define COERCE_ARRAY(arg)    \
 165 { COERCE_REF(arg);                                                      \
 166   if (current_language->c_style_arrays                                  \
 167       && (VALUE_REPEATED (arg)                                          \
 168           || TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY))          \
 169     arg = value_coerce_array (arg);                                     \
 170   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)                   \
 171     arg = value_coerce_function (arg);                                  \
 172   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 173     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 174 }
 175
 176 #define COERCE_VARYING_ARRAY(arg)       \
 177 { if (chill_varying_type (VALUE_TYPE (arg))) arg = varying_to_slice (arg); }
 178
 179 /* If ARG is an enum, convert it to an integer.  */
 180
 181 #define COERCE_ENUM(arg)    \
 182 { COERCE_REF (arg); \
 183   if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ENUM)                   \
 184     arg = value_cast (builtin_type_unsigned_int, arg);                  \
 185 }
 186
 187 /* Internal variables (variables for convenience of use of debugger)
 188    are recorded as a chain of these structures.  */
 189
 190 struct internalvar
 191 {
 192   struct internalvar *next;
 193   char *name;
 194   value_ptr value;
 195 };
 196
 197 /* Pointer to member function.  Depends on compiler implementation. */
 198
 199 #define METHOD_PTR_IS_VIRTUAL(ADDR)  ((ADDR) & 0x80000000)
 200 #define METHOD_PTR_FROM_VOFFSET(OFFSET) (0x80000000 + (OFFSET))
 201 #define METHOD_PTR_TO_VOFFSET(ADDR) (~0x80000000 & (ADDR))
 202
 203 \f
 204 #include "symtab.h"
 205 #include "gdbtypes.h"
 206 #include "expression.h"
 207
 208 #ifdef __STDC__
 209 struct frame_info;
 210 struct fn_field;
 211 #endif
 212
 213 extern void
 214 print_address_demangle PARAMS ((CORE_ADDR, GDB_FILE *, int));
 215
 216 extern LONGEST value_as_long PARAMS ((value_ptr val));
 217
 218 extern double value_as_double PARAMS ((value_ptr val));
 219
 220 extern CORE_ADDR value_as_pointer PARAMS ((value_ptr val));
 221
 222 extern LONGEST unpack_long PARAMS ((struct type *type, char *valaddr));
 223
 224 extern double unpack_double PARAMS ((struct type *type, char *valaddr,
 225                                      int *invp));
 226
 227 extern CORE_ADDR unpack_pointer PARAMS ((struct type *type, char *valaddr));
 228
 229 extern LONGEST unpack_field_as_long PARAMS ((struct type *type, char *valaddr,
 230                                              int fieldno));
 231
 232 extern value_ptr value_from_longest PARAMS ((struct type *type, LONGEST num));
 233
 234 extern value_ptr value_from_double PARAMS ((struct type *type, double num));
 235
 236 extern value_ptr value_at PARAMS ((struct type *type, CORE_ADDR addr));
 237
 238 extern value_ptr value_at_lazy PARAMS ((struct type *type, CORE_ADDR addr));
 239
 240 extern value_ptr value_from_register PARAMS ((struct type *type, int regnum,
 241                                           struct frame_info * frame));
 242
 243 extern value_ptr value_of_variable PARAMS ((struct symbol *var,
 244                                             struct block *b));
 245
 246 extern value_ptr value_of_register PARAMS ((int regnum));
 247
 248 extern int symbol_read_needs_frame PARAMS ((struct symbol *));
 249
 250 extern value_ptr read_var_value PARAMS ((struct symbol *var,
 251                                          struct frame_info *frame));
 252
 253 extern value_ptr locate_var_value PARAMS ((struct symbol *var,
 254                                        struct frame_info *frame));
 255
 256 extern value_ptr allocate_value PARAMS ((struct type *type));
 257
 258 extern value_ptr allocate_repeat_value PARAMS ((struct type *type, int count));
 259
 260 extern value_ptr value_mark PARAMS ((void));
 261
 262 extern void value_free_to_mark PARAMS ((value_ptr mark));
 263
 264 extern value_ptr value_string PARAMS ((char *ptr, int len));
 265 extern value_ptr value_bitstring PARAMS ((char *ptr, int len));
 266
 267 extern value_ptr value_array PARAMS ((int lowbound, int highbound,
 268                                       value_ptr *elemvec));
 269
 270 extern value_ptr value_concat PARAMS ((value_ptr arg1, value_ptr arg2));
 271
 272 extern value_ptr value_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 273                                       enum exp_opcode op));
 274
 275 extern value_ptr value_add PARAMS ((value_ptr arg1, value_ptr arg2));
 276
 277 extern value_ptr value_sub PARAMS ((value_ptr arg1, value_ptr arg2));
 278
 279 extern value_ptr value_coerce_array PARAMS ((value_ptr arg1));
 280
 281 extern value_ptr value_coerce_function PARAMS ((value_ptr arg1));
 282
 283 extern value_ptr value_ind PARAMS ((value_ptr arg1));
 284
 285 extern value_ptr value_addr PARAMS ((value_ptr arg1));
 286
 287 extern value_ptr value_assign PARAMS ((value_ptr toval, value_ptr fromval));
 288
 289 extern value_ptr value_neg PARAMS ((value_ptr arg1));
 290
 291 extern value_ptr value_complement PARAMS ((value_ptr arg1));
 292
 293 extern value_ptr value_struct_elt PARAMS ((value_ptr *argp, value_ptr *args,
 294                                            char *name,
 295                                            int *static_memfuncp, char *err));
 296
 297 extern value_ptr value_struct_elt_for_reference PARAMS ((struct type *domain,
 298                                                          int offset,
 299                                                          struct type *curtype,
 300                                                          char *name,
 301                                                          struct type *intype));
 302
 303 extern value_ptr value_field PARAMS ((value_ptr arg1, int fieldno));
 304
 305 extern value_ptr value_primitive_field PARAMS ((value_ptr arg1, int offset,
 306                                                 int fieldno,
 307                                                 struct type *arg_type));
 308
 309 extern value_ptr value_cast PARAMS ((struct type *type, value_ptr arg2));
 310
 311 extern value_ptr value_zero PARAMS ((struct type *type, enum lval_type lv));
 312
 313 extern value_ptr value_repeat PARAMS ((value_ptr arg1, int count));
 314
 315 extern value_ptr value_subscript PARAMS ((value_ptr array, value_ptr idx));
 316
 317 extern value_ptr value_from_vtable_info PARAMS ((value_ptr arg,
 318                                                  struct type *type));
 319
 320 extern value_ptr value_being_returned PARAMS ((struct type *valtype,
 321                                                char retbuf[REGISTER_BYTES],
 322                                                int struct_return));
 323
 324 extern value_ptr value_in PARAMS ((value_ptr element, value_ptr set));
 325
 326 extern int value_bit_index PARAMS ((struct type *type, char *addr, int index));
 327
 328 extern int using_struct_return PARAMS ((value_ptr function, CORE_ADDR funcaddr,
 329                                         struct type *value_type, int gcc_p));
 330
 331 extern void set_return_value PARAMS ((value_ptr val));
 332
 333 extern value_ptr evaluate_expression PARAMS ((struct expression *exp));
 334
 335 extern value_ptr evaluate_type PARAMS ((struct expression *exp));
 336
 337 extern value_ptr parse_and_eval PARAMS ((char *exp));
 338
 339 extern value_ptr parse_to_comma_and_eval PARAMS ((char **expp));
 340
 341 extern struct type *parse_and_eval_type PARAMS ((char *p, int length));
 342
 343 extern CORE_ADDR parse_and_eval_address PARAMS ((char *exp));
 344
 345 extern CORE_ADDR parse_and_eval_address_1 PARAMS ((char **expptr));
 346
 347 extern value_ptr access_value_history PARAMS ((int num));
 348
 349 extern value_ptr value_of_internalvar PARAMS ((struct internalvar *var));
 350
 351 extern void set_internalvar PARAMS ((struct internalvar *var, value_ptr val));
 352
 353 extern void set_internalvar_component PARAMS ((struct internalvar *var,
 354                                                int offset,
 355                                                int bitpos, int bitsize,
 356                                                value_ptr newvalue));
 357
 358 extern struct internalvar *lookup_internalvar PARAMS ((char *name));
 359
 360 extern int value_equal PARAMS ((value_ptr arg1, value_ptr arg2));
 361
 362 extern int value_less PARAMS ((value_ptr arg1, value_ptr arg2));
 363
 364 extern int value_logical_not PARAMS ((value_ptr arg1));
 365
 366 /* C++ */
 367
 368 extern value_ptr value_of_this PARAMS ((int complain));
 369
 370 extern value_ptr value_x_binop PARAMS ((value_ptr arg1, value_ptr arg2,
 371                                         enum exp_opcode op,
 372                                         enum exp_opcode otherop));
 373
 374 extern value_ptr value_x_unop PARAMS ((value_ptr arg1, enum exp_opcode op));
 375
 376 extern value_ptr value_fn_field PARAMS ((value_ptr *arg1p, struct fn_field *f,
 377                                          int j,
 378                                          struct type* type, int offset));
 379
 380 extern value_ptr value_virtual_fn_field PARAMS ((value_ptr *arg1p,
 381                                                  struct fn_field *f, int j,
 382                                                  struct type *type,
 383                                                  int offset));
 384
 385 extern int binop_user_defined_p PARAMS ((enum exp_opcode op,
 386                                          value_ptr arg1, value_ptr arg2));
 387
 388 extern int unop_user_defined_p PARAMS ((enum exp_opcode op, value_ptr arg1));
 389
 390 extern int destructor_name_p PARAMS ((const char *name,
 391                                       const struct type *type));
 392
 393 #define value_free(val) free ((PTR)val)
 394
 395 extern void free_all_values PARAMS ((void));
 396
 397 extern void release_value PARAMS ((value_ptr val));
 398
 399 extern int record_latest_value PARAMS ((value_ptr val));
 400
 401 extern void registers_changed PARAMS ((void));
 402
 403 extern void read_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 404
 405 extern void write_register_bytes PARAMS ((int regbyte, char *myaddr, int len));
 406
 407 extern void
 408 read_register_gen PARAMS ((int regno, char *myaddr));
 409
 410 extern CORE_ADDR
 411 read_register PARAMS ((int regno));
 412
 413 extern void
 414 write_register PARAMS ((int regno, LONGEST val));
 415
 416 extern void
 417 supply_register PARAMS ((int regno, char *val));
 418
 419 extern void
 420 get_saved_register PARAMS ((char *raw_buffer, int *optimized,
 421                             CORE_ADDR *addrp, struct frame_info *frame,
 422                             int regnum, enum lval_type *lval));
 423
 424 extern void
 425 modify_field PARAMS ((char *addr, LONGEST fieldval, int bitpos, int bitsize));
 426
 427 extern void
 428 type_print PARAMS ((struct type *type, char *varstring, GDB_FILE *stream,
 429                     int show));
 430
 431 extern char *baseclass_addr PARAMS ((struct type *type, int index,
 432                                      char *valaddr,
 433                                      value_ptr *valuep, int *errp));
 434
 435 extern void
 436 print_longest PARAMS ((GDB_FILE *stream, int format, int use_local,
 437                        LONGEST val));
 438
 439 extern void
 440 print_floating PARAMS ((char *valaddr, struct type *type, GDB_FILE *stream));
 441
 442 extern int value_print PARAMS ((value_ptr val, GDB_FILE *stream, int format,
 443                                 enum val_prettyprint pretty));
 444
 445 extern void
 446 value_print_array_elements PARAMS ((value_ptr val, GDB_FILE* stream,
 447                                     int format, enum val_prettyprint pretty));
 448
 449 extern value_ptr
 450 value_release_to_mark PARAMS ((value_ptr mark));
 451
 452 extern int
 453 val_print PARAMS ((struct type *type, char *valaddr, CORE_ADDR address,
 454                    GDB_FILE *stream, int format, int deref_ref,
 455                    int recurse, enum val_prettyprint pretty));
 456
 457 extern int
 458 val_print_string PARAMS ((CORE_ADDR addr, unsigned int len, GDB_FILE *stream));
 459
 460 extern void
 461 print_variable_value PARAMS ((struct symbol *var, struct frame_info *frame,
 462                               GDB_FILE *stream));
 463
 464 extern int check_field PARAMS ((value_ptr, const char *));
 465
 466 extern void
 467 c_typedef_print PARAMS ((struct type *type, struct symbol *news, GDB_FILE *stream));
 468
 469 extern char *
 470 internalvar_name PARAMS ((struct internalvar *var));
 471
 472 extern void
 473 clear_value_history PARAMS ((void));
 474
 475 extern void
 476 clear_internalvars PARAMS ((void));
 477
 478 /* From values.c */
 479
 480 extern value_ptr value_copy PARAMS ((value_ptr));
 481
 482 extern int baseclass_offset PARAMS ((struct type *, int, value_ptr, int));
 483
 484 /* From valops.c */
 485
 486 extern value_ptr varying_to_slice PARAMS ((value_ptr));
 487
 488 extern value_ptr value_slice PARAMS ((value_ptr, int, int));
 489
 490 extern value_ptr call_function_by_hand PARAMS ((value_ptr, int, value_ptr *));
 491
 492 extern value_ptr value_literal_complex PARAMS ((value_ptr, value_ptr, struct type*));
 493
 494 #endif  /* !defined (VALUE_H) */