gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2
   3    Copyright (C) 1986-2013 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (VALUE_H)
  21 #define VALUE_H 1
  22
  23 #include "doublest.h"
  24 #include "frame.h"              /* For struct frame_id.  */
  25
  26 struct block;
  27 struct expression;
  28 struct regcache;
  29 struct symbol;
  30 struct type;
  31 struct ui_file;
  32 struct language_defn;
  33 struct value_print_options;
  34
  35 /* The structure which defines the type of a value.  It should never
  36    be possible for a program lval value to survive over a call to the
  37    inferior (i.e. to be put into the history list or an internal
  38    variable).  */
  39
  40 struct value;
  41
  42 /* Values are stored in a chain, so that they can be deleted easily
  43    over calls to the inferior.  Values assigned to internal variables,
  44    put into the value history or exposed to Python are taken off this
  45    list.  */
  46
  47 struct value *value_next (struct value *);
  48
  49 /* Type of the value.  */
  50
  51 extern struct type *value_type (const struct value *);
  52
  53 /* This is being used to change the type of an existing value, that
  54    code should instead be creating a new value with the changed type
  55    (but possibly shared content).  */
  56
  57 extern void deprecated_set_value_type (struct value *value,
  58                                        struct type *type);
  59
  60 /* Only used for bitfields; number of bits contained in them.  */
  61
  62 extern int value_bitsize (const struct value *);
  63 extern void set_value_bitsize (struct value *, int bit);
  64
  65 /* Only used for bitfields; position of start of field.  For
  66    gdbarch_bits_big_endian=0 targets, it is the position of the LSB.  For
  67    gdbarch_bits_big_endian=1 targets, it is the position of the MSB.  */
  68
  69 extern int value_bitpos (const struct value *);
  70 extern void set_value_bitpos (struct value *, int bit);
  71
  72 /* Only used for bitfields; the containing value.  This allows a
  73    single read from the target when displaying multiple
  74    bitfields.  */
  75
  76 struct value *value_parent (struct value *);
  77 extern void set_value_parent (struct value *value, struct value *parent);
  78
  79 /* Describes offset of a value within lval of a structure in bytes.
  80    If lval == lval_memory, this is an offset to the address.  If lval
  81    == lval_register, this is a further offset from location.address
  82    within the registers structure.  Note also the member
  83    embedded_offset below.  */
  84
  85 extern int value_offset (const struct value *);
  86 extern void set_value_offset (struct value *, int offset);
  87
  88 /* The comment from "struct value" reads: ``Is it modifiable?  Only
  89    relevant if lval != not_lval.''.  Shouldn't the value instead be
  90    not_lval and be done with it?  */
  91
  92 extern int deprecated_value_modifiable (struct value *value);
  93
  94 /* If a value represents a C++ object, then the `type' field gives the
  95    object's compile-time type.  If the object actually belongs to some
  96    class derived from `type', perhaps with other base classes and
  97    additional members, then `type' is just a subobject of the real
  98    thing, and the full object is probably larger than `type' would
  99    suggest.
 100
 101    If `type' is a dynamic class (i.e. one with a vtable), then GDB can
 102    actually determine the object's run-time type by looking at the
 103    run-time type information in the vtable.  When this information is
 104    available, we may elect to read in the entire object, for several
 105    reasons:
 106
 107    - When printing the value, the user would probably rather see the
 108      full object, not just the limited portion apparent from the
 109      compile-time type.
 110
 111    - If `type' has virtual base classes, then even printing `type'
 112      alone may require reaching outside the `type' portion of the
 113      object to wherever the virtual base class has been stored.
 114
 115    When we store the entire object, `enclosing_type' is the run-time
 116    type -- the complete object -- and `embedded_offset' is the offset
 117    of `type' within that larger type, in bytes.  The value_contents()
 118    macro takes `embedded_offset' into account, so most GDB code
 119    continues to see the `type' portion of the value, just as the
 120    inferior would.
 121
 122    If `type' is a pointer to an object, then `enclosing_type' is a
 123    pointer to the object's run-time type, and `pointed_to_offset' is
 124    the offset in bytes from the full object to the pointed-to object
 125    -- that is, the value `embedded_offset' would have if we followed
 126    the pointer and fetched the complete object.  (I don't really see
 127    the point.  Why not just determine the run-time type when you
 128    indirect, and avoid the special case?  The contents don't matter
 129    until you indirect anyway.)
 130
 131    If we're not doing anything fancy, `enclosing_type' is equal to
 132    `type', and `embedded_offset' is zero, so everything works
 133    normally.  */
 134
 135 extern struct type *value_enclosing_type (struct value *);
 136 extern void set_value_enclosing_type (struct value *val,
 137                                       struct type *new_type);
 138
 139 /* Returns value_type or value_enclosing_type depending on
 140    value_print_options.objectprint.
 141
 142    If RESOLVE_SIMPLE_TYPES is 0 the enclosing type will be resolved
 143    only for pointers and references, else it will be returned
 144    for all the types (e.g. structures).  This option is useful
 145    to prevent retrieving enclosing type for the base classes fields.
 146
 147    REAL_TYPE_FOUND is used to inform whether the real type was found
 148    (or just static type was used).  The NULL may be passed if it is not
 149    necessary. */
 150
 151 extern struct type *value_actual_type (struct value *value,
 152                                        int resolve_simple_types,
 153                                        int *real_type_found);
 154
 155 extern int value_pointed_to_offset (struct value *value);
 156 extern void set_value_pointed_to_offset (struct value *value, int val);
 157 extern int value_embedded_offset (struct value *value);
 158 extern void set_value_embedded_offset (struct value *value, int val);
 159
 160 /* For lval_computed values, this structure holds functions used to
 161    retrieve and set the value (or portions of the value).
 162
 163    For each function, 'V' is the 'this' pointer: an lval_funcs
 164    function F may always assume that the V it receives is an
 165    lval_computed value, and has F in the appropriate slot of its
 166    lval_funcs structure.  */
 167
 168 struct lval_funcs
 169 {
 170   /* Fill in VALUE's contents.  This is used to "un-lazy" values.  If
 171      a problem arises in obtaining VALUE's bits, this function should
 172      call 'error'.  If it is NULL value_fetch_lazy on "un-lazy"
 173      non-optimized-out value is an internal error.  */
 174   void (*read) (struct value *v);
 175
 176   /* Handle an assignment TOVAL = FROMVAL by writing the value of
 177      FROMVAL to TOVAL's location.  The contents of TOVAL have not yet
 178      been updated.  If a problem arises in doing so, this function
 179      should call 'error'.  If it is NULL such TOVAL assignment is an error as
 180      TOVAL is not considered as an lvalue.  */
 181   void (*write) (struct value *toval, struct value *fromval);
 182
 183   /* Check the validity of some bits in VALUE.  This should return 1
 184      if all the bits starting at OFFSET and extending for LENGTH bits
 185      are valid, or 0 if any bit is invalid.  */
 186   int (*check_validity) (const struct value *value, int offset, int length);
 187
 188   /* Return 1 if any bit in VALUE is valid, 0 if they are all invalid.  */
 189   int (*check_any_valid) (const struct value *value);
 190
 191   /* If non-NULL, this is used to implement pointer indirection for
 192      this value.  This method may return NULL, in which case value_ind
 193      will fall back to ordinary indirection.  */
 194   struct value *(*indirect) (struct value *value);
 195
 196   /* If non-NULL, this is used to implement reference resolving for
 197      this value.  This method may return NULL, in which case coerce_ref
 198      will fall back to ordinary references resolving.  */
 199   struct value *(*coerce_ref) (const struct value *value);
 200
 201   /* If non-NULL, this is used to determine whether the indicated bits
 202      of VALUE are a synthetic pointer.  */
 203   int (*check_synthetic_pointer) (const struct value *value,
 204                                   int offset, int length);
 205
 206   /* Return a duplicate of VALUE's closure, for use in a new value.
 207      This may simply return the same closure, if VALUE's is
 208      reference-counted or statically allocated.
 209
 210      This may be NULL, in which case VALUE's closure is re-used in the
 211      new value.  */
 212   void *(*copy_closure) (const struct value *v);
 213
 214   /* Drop VALUE's reference to its closure.  Maybe this frees the
 215      closure; maybe this decrements a reference count; maybe the
 216      closure is statically allocated and this does nothing.
 217
 218      This may be NULL, in which case no action is taken to free
 219      VALUE's closure.  */
 220   void (*free_closure) (struct value *v);
 221 };
 222
 223 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
 224    and closure CLOSURE.  */
 225
 226 extern struct value *allocate_computed_value (struct type *type,
 227                                               const struct lval_funcs *funcs,
 228                                               void *closure);
 229
 230 /* Helper function to check the validity of some bits of a value.
 231
 232    If TYPE represents some aggregate type (e.g., a structure), return 1.
 233
 234    Otherwise, any of the bytes starting at OFFSET and extending for
 235    TYPE_LENGTH(TYPE) bytes are invalid, print a message to STREAM and
 236    return 0.  The checking is done using FUNCS.
 237
 238    Otherwise, return 1.  */
 239
 240 extern int valprint_check_validity (struct ui_file *stream, struct type *type,
 241                                     int embedded_offset,
 242                                     const struct value *val);
 243
 244 extern struct value *allocate_optimized_out_value (struct type *type);
 245
 246 /* If VALUE is lval_computed, return its lval_funcs structure.  */
 247
 248 extern const struct lval_funcs *value_computed_funcs (const struct value *);
 249
 250 /* If VALUE is lval_computed, return its closure.  The meaning of the
 251    returned value depends on the functions VALUE uses.  */
 252
 253 extern void *value_computed_closure (const struct value *value);
 254
 255 /* If zero, contents of this value are in the contents field.  If
 256    nonzero, contents are in inferior.  If the lval field is lval_memory,
 257    the contents are in inferior memory at location.address plus offset.
 258    The lval field may also be lval_register.
 259
 260    WARNING: This field is used by the code which handles watchpoints
 261    (see breakpoint.c) to decide whether a particular value can be
 262    watched by hardware watchpoints.  If the lazy flag is set for some
 263    member of a value chain, it is assumed that this member of the
 264    chain doesn't need to be watched as part of watching the value
 265    itself.  This is how GDB avoids watching the entire struct or array
 266    when the user wants to watch a single struct member or array
 267    element.  If you ever change the way lazy flag is set and reset, be
 268    sure to consider this use as well!  */
 269
 270 extern int value_lazy (struct value *);
 271 extern void set_value_lazy (struct value *value, int val);
 272
 273 extern int value_stack (struct value *);
 274 extern void set_value_stack (struct value *value, int val);
 275
 276 /* value_contents() and value_contents_raw() both return the address
 277    of the gdb buffer used to hold a copy of the contents of the lval.
 278    value_contents() is used when the contents of the buffer are needed
 279    -- it uses value_fetch_lazy() to load the buffer from the process
 280    being debugged if it hasn't already been loaded
 281    (value_contents_writeable() is used when a writeable but fetched
 282    buffer is required)..  value_contents_raw() is used when data is
 283    being stored into the buffer, or when it is certain that the
 284    contents of the buffer are valid.
 285
 286    Note: The contents pointer is adjusted by the offset required to
 287    get to the real subobject, if the value happens to represent
 288    something embedded in a larger run-time object.  */
 289
 290 extern gdb_byte *value_contents_raw (struct value *);
 291
 292 /* Actual contents of the value.  For use of this value; setting it
 293    uses the stuff above.  Not valid if lazy is nonzero.  Target
 294    byte-order.  We force it to be aligned properly for any possible
 295    value.  Note that a value therefore extends beyond what is
 296    declared here.  */
 297
 298 extern const gdb_byte *value_contents (struct value *);
 299 extern gdb_byte *value_contents_writeable (struct value *);
 300
 301 /* The ALL variants of the above two macros do not adjust the returned
 302    pointer by the embedded_offset value.  */
 303
 304 extern gdb_byte *value_contents_all_raw (struct value *);
 305 extern const gdb_byte *value_contents_all (struct value *);
 306
 307 /* Like value_contents_all, but does not require that the returned
 308    bits be valid.  This should only be used in situations where you
 309    plan to check the validity manually.  */
 310 extern const gdb_byte *value_contents_for_printing (struct value *value);
 311
 312 /* Like value_contents_for_printing, but accepts a constant value
 313    pointer.  Unlike value_contents_for_printing however, the pointed
 314    value must _not_ be lazy.  */
 315 extern const gdb_byte *
 316   value_contents_for_printing_const (const struct value *value);
 317
 318 extern int value_fetch_lazy (struct value *val);
 319 extern int value_contents_equal (struct value *val1, struct value *val2);
 320
 321 /* If nonzero, this is the value of a variable which does not actually
 322    exist in the program, at least partially.  If the value is lazy,
 323    this may fetch it now.  */
 324 extern int value_optimized_out (struct value *value);
 325 extern void set_value_optimized_out (struct value *value, int val);
 326
 327 /* Like value_optimized_out, but don't fetch the value even if it is
 328    lazy.  Mainly useful for constructing other values using VALUE as
 329    template.  */
 330 extern int value_optimized_out_const (const struct value *value);
 331
 332 /* Like value_optimized_out, but return false if any bit in the object
 333    is valid.  */
 334 extern int value_entirely_optimized_out (const struct value *value);
 335
 336 /* Set or return field indicating whether a variable is initialized or
 337    not, based on debugging information supplied by the compiler.
 338    1 = initialized; 0 = uninitialized.  */
 339 extern int value_initialized (struct value *);
 340 extern void set_value_initialized (struct value *, int);
 341
 342 /* Set COMPONENT's location as appropriate for a component of WHOLE
 343    --- regardless of what kind of lvalue WHOLE is.  */
 344 extern void set_value_component_location (struct value *component,
 345                                           const struct value *whole);
 346
 347 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
 348    single value might have multiple LVALs), this hacked interface is
 349    limited to just the first PIECE.  Expect further change.  */
 350 /* Type of value; either not an lval, or one of the various different
 351    possible kinds of lval.  */
 352 extern enum lval_type *deprecated_value_lval_hack (struct value *);
 353 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
 354
 355 /* Like VALUE_LVAL, except the parameter can be const.  */
 356 extern enum lval_type value_lval_const (const struct value *value);
 357
 358 /* If lval == lval_memory, return the address in the inferior.  If
 359    lval == lval_register, return the byte offset into the registers
 360    structure.  Otherwise, return 0.  The returned address
 361    includes the offset, if any.  */
 362 extern CORE_ADDR value_address (const struct value *);
 363
 364 /* Like value_address, except the result does not include value's
 365    offset.  */
 366 extern CORE_ADDR value_raw_address (struct value *);
 367
 368 /* Set the address of a value.  */
 369 extern void set_value_address (struct value *, CORE_ADDR);
 370
 371 /* Pointer to internal variable.  */
 372 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
 373 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
 374
 375 /* Frame register value is relative to.  This will be described in the
 376    lval enum above as "lval_register".  */
 377 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
 378 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
 379
 380 /* Register number if the value is from a register.  */
 381 extern short *deprecated_value_regnum_hack (struct value *);
 382 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
 383
 384 /* Return value after lval_funcs->coerce_ref (after check_typedef).  Return
 385    NULL if lval_funcs->coerce_ref is not applicable for whatever reason.  */
 386
 387 extern struct value *coerce_ref_if_computed (const struct value *arg);
 388
 389 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
 390    ENC_TYPE is the new enclosing type that should be set.  ORIGINAL_TYPE and
 391    ORIGINAL_VAL are the type and value of the original reference or pointer.
 392
 393    Note, that VALUE is modified by this function.
 394
 395    It is a common implementation for coerce_ref and value_ind.  */
 396
 397 extern struct value * readjust_indirect_value_type (struct value *value,
 398                                                     struct type *enc_type,
 399                                                     struct type *original_type,
 400                                                     struct value *original_val);
 401
 402 /* Convert a REF to the object referenced.  */
 403
 404 extern struct value *coerce_ref (struct value *value);
 405
 406 /* If ARG is an array, convert it to a pointer.
 407    If ARG is a function, convert it to a function pointer.
 408
 409    References are dereferenced.  */
 410
 411 extern struct value *coerce_array (struct value *value);
 412
 413 /* Given a value, determine whether the bits starting at OFFSET and
 414    extending for LENGTH bits are valid.  This returns nonzero if all
 415    bits in the given range are valid, zero if any bit is invalid.  */
 416
 417 extern int value_bits_valid (const struct value *value,
 418                              int offset, int length);
 419
 420 /* Given a value, determine whether the bits starting at OFFSET and
 421    extending for LENGTH bits are a synthetic pointer.  */
 422
 423 extern int value_bits_synthetic_pointer (const struct value *value,
 424                                          int offset, int length);
 425
 426 /* Given a value, determine whether the contents bytes starting at
 427    OFFSET and extending for LENGTH bytes are available.  This returns
 428    nonzero if all bytes in the given range are available, zero if any
 429    byte is unavailable.  */
 430
 431 extern int value_bytes_available (const struct value *value,
 432                                   int offset, int length);
 433
 434 /* Like value_bytes_available, but return false if any byte in the
 435    whole object is unavailable.  */
 436 extern int value_entirely_available (struct value *value);
 437
 438 /* Mark VALUE's content bytes starting at OFFSET and extending for
 439    LENGTH bytes as unavailable.  */
 440
 441 extern void mark_value_bytes_unavailable (struct value *value,
 442                                           int offset, int length);
 443
 444 /* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
 445    LENGTH bytes of VAL2's contents starting at OFFSET2.
 446
 447    Note that "contents" refers to the whole value's contents
 448    (value_contents_all), without any embedded offset adjustment.  For
 449    example, to compare a complete object value with itself, including
 450    its enclosing type chunk, you'd do:
 451
 452      int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
 453      value_available_contents (val, 0, val, 0, len);
 454
 455    Returns true iff the set of available contents match.  Unavailable
 456    contents compare equal with unavailable contents, and different
 457    with any available byte.  For example, if 'x's represent an
 458    unavailable byte, and 'V' and 'Z' represent different available
 459    bytes, in a value with length 16:
 460
 461    offset:   0   4   8   12  16
 462    contents: xxxxVVVVxxxxVVZZ
 463
 464    then:
 465
 466    value_available_contents_eq(val, 0, val, 8, 6) => 1
 467    value_available_contents_eq(val, 0, val, 4, 4) => 1
 468    value_available_contents_eq(val, 0, val, 8, 8) => 0
 469    value_available_contents_eq(val, 4, val, 12, 2) => 1
 470    value_available_contents_eq(val, 4, val, 12, 4) => 0
 471    value_available_contents_eq(val, 3, val, 4, 4) => 0
 472
 473    We only know whether a value chunk is available if we've tried to
 474    read it.  As this routine is used by printing routines, which may
 475    be printing values in the value history, long after the inferior is
 476    gone, it works with const values.  Therefore, this routine must not
 477    be called with lazy values.  */
 478
 479 extern int value_available_contents_eq (const struct value *val1, int offset1,
 480                                         const struct value *val2, int offset2,
 481                                         int length);
 482
 483 /* Read LENGTH bytes of memory starting at MEMADDR into BUFFER, which
 484    is (or will be copied to) VAL's contents buffer offset by
 485    EMBEDDED_OFFSET (that is, to &VAL->contents[EMBEDDED_OFFSET]).
 486    Marks value contents ranges as unavailable if the corresponding
 487    memory is likewise unavailable.  STACK indicates whether the memory
 488    is known to be stack memory.  */
 489
 490 extern void read_value_memory (struct value *val, int embedded_offset,
 491                                int stack, CORE_ADDR memaddr,
 492                                gdb_byte *buffer, size_t length);
 493
 494 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
 495    into each element of a new vector value with VECTOR_TYPE.  */
 496
 497 struct value *value_vector_widen (struct value *scalar_value,
 498                                   struct type *vector_type);
 499
 500 \f
 501
 502 #include "symtab.h"
 503 #include "gdbtypes.h"
 504 #include "expression.h"
 505
 506 struct frame_info;
 507 struct fn_field;
 508
 509 extern int print_address_demangle (const struct value_print_options *,
 510                                    struct gdbarch *, CORE_ADDR,
 511                                    struct ui_file *, int);
 512
 513 extern LONGEST value_as_long (struct value *val);
 514 extern DOUBLEST value_as_double (struct value *val);
 515 extern CORE_ADDR value_as_address (struct value *val);
 516
 517 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
 518 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
 519                                int *invp);
 520 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
 521
 522 extern int unpack_value_bits_as_long (struct type *field_type,
 523                                       const gdb_byte *valaddr,
 524                                       int embedded_offset, int bitpos,
 525                                       int bitsize,
 526                                       const struct value *original_value,
 527                                       LONGEST *result);
 528
 529 extern LONGEST unpack_field_as_long (struct type *type,
 530                                      const gdb_byte *valaddr,
 531                                      int fieldno);
 532 extern int unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
 533                                 int embedded_offset, int fieldno,
 534                                 const struct value *val, LONGEST *result);
 535
 536 extern struct value *value_field_bitfield (struct type *type, int fieldno,
 537                                            const gdb_byte *valaddr,
 538                                            int embedded_offset,
 539                                            const struct value *val);
 540
 541 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
 542
 543 extern struct value *value_from_longest (struct type *type, LONGEST num);
 544 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
 545 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
 546 extern struct value *value_from_double (struct type *type, DOUBLEST num);
 547 extern struct value *value_from_decfloat (struct type *type,
 548                                           const gdb_byte *decbytes);
 549 extern struct value *value_from_history_ref (char *, char **);
 550
 551 extern struct value *value_at (struct type *type, CORE_ADDR addr);
 552 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
 553
 554 extern struct value *value_from_contents_and_address (struct type *,
 555                                                       const gdb_byte *,
 556                                                       CORE_ADDR);
 557 extern struct value *value_from_contents (struct type *, const gdb_byte *);
 558
 559 extern struct value *default_value_from_register (struct type *type,
 560                                                   int regnum,
 561                                                   struct frame_info *frame);
 562
 563 extern void read_frame_register_value (struct value *value,
 564                                        struct frame_info *frame);
 565
 566 extern struct value *value_from_register (struct type *type, int regnum,
 567                                           struct frame_info *frame);
 568
 569 extern CORE_ADDR address_from_register (struct type *type, int regnum,
 570                                         struct frame_info *frame);
 571
 572 extern struct value *value_of_variable (struct symbol *var,
 573                                         const struct block *b);
 574
 575 extern struct value *address_of_variable (struct symbol *var,
 576                                           const struct block *b);
 577
 578 extern struct value *value_of_register (int regnum, struct frame_info *frame);
 579
 580 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
 581
 582 extern int symbol_read_needs_frame (struct symbol *);
 583
 584 extern struct value *read_var_value (struct symbol *var,
 585                                      struct frame_info *frame);
 586
 587 extern struct value *default_read_var_value (struct symbol *var,
 588                                              struct frame_info *frame);
 589
 590 extern struct value *allocate_value (struct type *type);
 591 extern struct value *allocate_value_lazy (struct type *type);
 592 extern void allocate_value_contents (struct value *value);
 593 extern void value_contents_copy (struct value *dst, int dst_offset,
 594                                  struct value *src, int src_offset,
 595                                  int length);
 596 extern void value_contents_copy_raw (struct value *dst, int dst_offset,
 597                                      struct value *src, int src_offset,
 598                                      int length);
 599
 600 extern struct value *allocate_repeat_value (struct type *type, int count);
 601
 602 extern struct value *value_mark (void);
 603
 604 extern void value_free_to_mark (struct value *mark);
 605
 606 extern struct value *value_cstring (char *ptr, ssize_t len,
 607                                     struct type *char_type);
 608 extern struct value *value_string (char *ptr, ssize_t len,
 609                                    struct type *char_type);
 610
 611 extern struct value *value_array (int lowbound, int highbound,
 612                                   struct value **elemvec);
 613
 614 extern struct value *value_concat (struct value *arg1, struct value *arg2);
 615
 616 extern struct value *value_binop (struct value *arg1, struct value *arg2,
 617                                   enum exp_opcode op);
 618
 619 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
 620
 621 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
 622
 623 extern int value_must_coerce_to_target (struct value *arg1);
 624
 625 extern struct value *value_coerce_to_target (struct value *arg1);
 626
 627 extern struct value *value_coerce_array (struct value *arg1);
 628
 629 extern struct value *value_coerce_function (struct value *arg1);
 630
 631 extern struct value *value_ind (struct value *arg1);
 632
 633 extern struct value *value_addr (struct value *arg1);
 634
 635 extern struct value *value_ref (struct value *arg1);
 636
 637 extern struct value *value_assign (struct value *toval,
 638                                    struct value *fromval);
 639
 640 extern struct value *value_pos (struct value *arg1);
 641
 642 extern struct value *value_neg (struct value *arg1);
 643
 644 extern struct value *value_complement (struct value *arg1);
 645
 646 extern struct value *value_struct_elt (struct value **argp,
 647                                        struct value **args,
 648                                        const char *name, int *static_memfuncp,
 649                                        const char *err);
 650
 651 extern struct value *value_aggregate_elt (struct type *curtype,
 652                                           char *name,
 653                                           struct type *expect_type,
 654                                           int want_address,
 655                                           enum noside noside);
 656
 657 extern struct value *value_static_field (struct type *type, int fieldno);
 658
 659 enum oload_search_type { NON_METHOD, METHOD, BOTH };
 660
 661 extern int find_overload_match (struct value **args, int nargs,
 662                                 const char *name,
 663                                 enum oload_search_type method,
 664                                 struct value **objp, struct symbol *fsym,
 665                                 struct value **valp, struct symbol **symp,
 666                                 int *staticp, const int no_adl);
 667
 668 extern struct value *value_field (struct value *arg1, int fieldno);
 669
 670 extern struct value *value_primitive_field (struct value *arg1, int offset,
 671                                             int fieldno,
 672                                             struct type *arg_type);
 673
 674
 675 extern struct type *value_rtti_indirect_type (struct value *, int *, int *,
 676                                               int *);
 677
 678 extern struct value *value_full_object (struct value *, struct type *, int,
 679                                         int, int);
 680
 681 extern struct value *value_cast_pointers (struct type *, struct value *, int);
 682
 683 extern struct value *value_cast (struct type *type, struct value *arg2);
 684
 685 extern struct value *value_reinterpret_cast (struct type *type,
 686                                              struct value *arg);
 687
 688 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
 689
 690 extern struct value *value_zero (struct type *type, enum lval_type lv);
 691
 692 extern struct value *value_one (struct type *type);
 693
 694 extern struct value *value_repeat (struct value *arg1, int count);
 695
 696 extern struct value *value_subscript (struct value *array, LONGEST index);
 697
 698 extern struct value *value_bitstring_subscript (struct type *type,
 699                                                 struct value *bitstring,
 700                                                 LONGEST index);
 701
 702 extern struct value *register_value_being_returned (struct type *valtype,
 703                                                     struct regcache *retbuf);
 704
 705 extern int value_in (struct value *element, struct value *set);
 706
 707 extern int value_bit_index (struct type *type, const gdb_byte *addr,
 708                             int index);
 709
 710 extern enum return_value_convention
 711 struct_return_convention (struct gdbarch *gdbarch, struct value *function,
 712                           struct type *value_type);
 713
 714 extern int using_struct_return (struct gdbarch *gdbarch,
 715                                 struct value *function,
 716                                 struct type *value_type);
 717
 718 extern struct value *evaluate_expression (struct expression *exp);
 719
 720 extern struct value *evaluate_type (struct expression *exp);
 721
 722 extern struct value *evaluate_subexp (struct type *expect_type,
 723                                       struct expression *exp,
 724                                       int *pos, enum noside noside);
 725
 726 extern struct value *evaluate_subexpression_type (struct expression *exp,
 727                                                   int subexp);
 728
 729 extern void fetch_subexp_value (struct expression *exp, int *pc,
 730                                 struct value **valp, struct value **resultp,
 731                                 struct value **val_chain);
 732
 733 extern char *extract_field_op (struct expression *exp, int *subexp);
 734
 735 extern struct value *evaluate_subexp_with_coercion (struct expression *,
 736                                                     int *, enum noside);
 737
 738 extern struct value *parse_and_eval (const char *exp);
 739
 740 extern struct value *parse_to_comma_and_eval (const char **expp);
 741
 742 extern struct type *parse_and_eval_type (char *p, int length);
 743
 744 extern CORE_ADDR parse_and_eval_address (const char *exp);
 745
 746 extern LONGEST parse_and_eval_long (const char *exp);
 747
 748 extern void unop_promote (const struct language_defn *language,
 749                           struct gdbarch *gdbarch,
 750                           struct value **arg1);
 751
 752 extern void binop_promote (const struct language_defn *language,
 753                            struct gdbarch *gdbarch,
 754                            struct value **arg1, struct value **arg2);
 755
 756 extern struct value *access_value_history (int num);
 757
 758 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
 759                                            struct internalvar *var);
 760
 761 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
 762
 763 extern void set_internalvar (struct internalvar *var, struct value *val);
 764
 765 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
 766
 767 extern void set_internalvar_string (struct internalvar *var,
 768                                     const char *string);
 769
 770 extern void clear_internalvar (struct internalvar *var);
 771
 772 extern void set_internalvar_component (struct internalvar *var,
 773                                        int offset,
 774                                        int bitpos, int bitsize,
 775                                        struct value *newvalue);
 776
 777 extern struct internalvar *lookup_only_internalvar (const char *name);
 778
 779 extern struct internalvar *create_internalvar (const char *name);
 780
 781 extern VEC (char_ptr) *complete_internalvar (const char *name);
 782
 783 /* An internalvar can be dynamically computed by supplying a vector of
 784    function pointers to perform various operations.  */
 785
 786 struct internalvar_funcs
 787 {
 788   /* Compute the value of the variable.  The DATA argument passed to
 789      the function is the same argument that was passed to
 790      `create_internalvar_type_lazy'.  */
 791
 792   struct value *(*make_value) (struct gdbarch *arch,
 793                                struct internalvar *var,
 794                                void *data);
 795
 796   /* Update the agent expression EXPR with bytecode to compute the
 797      value.  VALUE is the agent value we are updating.  The DATA
 798      argument passed to this function is the same argument that was
 799      passed to `create_internalvar_type_lazy'.  If this pointer is
 800      NULL, then the internalvar cannot be compiled to an agent
 801      expression.  */
 802
 803   void (*compile_to_ax) (struct internalvar *var,
 804                          struct agent_expr *expr,
 805                          struct axs_value *value,
 806                          void *data);
 807
 808   /* If non-NULL, this is called to destroy DATA.  The DATA argument
 809      passed to this function is the same argument that was passed to
 810      `create_internalvar_type_lazy'.  */
 811
 812   void (*destroy) (void *data);
 813 };
 814
 815 extern struct internalvar *
 816 create_internalvar_type_lazy (const char *name,
 817                               const struct internalvar_funcs *funcs,
 818                               void *data);
 819
 820 /* Compile an internal variable to an agent expression.  VAR is the
 821    variable to compile; EXPR and VALUE are the agent expression we are
 822    updating.  This will return 0 if there is no known way to compile
 823    VAR, and 1 if VAR was successfully compiled.  It may also throw an
 824    exception on error.  */
 825
 826 extern int compile_internalvar_to_ax (struct internalvar *var,
 827                                       struct agent_expr *expr,
 828                                       struct axs_value *value);
 829
 830 extern struct internalvar *lookup_internalvar (const char *name);
 831
 832 extern int value_equal (struct value *arg1, struct value *arg2);
 833
 834 extern int value_equal_contents (struct value *arg1, struct value *arg2);
 835
 836 extern int value_less (struct value *arg1, struct value *arg2);
 837
 838 extern int value_logical_not (struct value *arg1);
 839
 840 /* C++ */
 841
 842 extern struct value *value_of_this (const struct language_defn *lang);
 843
 844 extern struct value *value_of_this_silent (const struct language_defn *lang);
 845
 846 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
 847                                     enum exp_opcode op,
 848                                     enum exp_opcode otherop,
 849                                     enum noside noside);
 850
 851 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
 852                                    enum noside noside);
 853
 854 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
 855                                      int j, struct type *type, int offset);
 856
 857 extern int binop_types_user_defined_p (enum exp_opcode op,
 858                                        struct type *type1,
 859                                        struct type *type2);
 860
 861 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
 862                                  struct value *arg2);
 863
 864 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
 865
 866 extern int destructor_name_p (const char *name, struct type *type);
 867
 868 extern void value_incref (struct value *val);
 869
 870 extern void value_free (struct value *val);
 871
 872 extern void free_all_values (void);
 873
 874 extern void free_value_chain (struct value *v);
 875
 876 extern void release_value (struct value *val);
 877
 878 extern void release_value_or_incref (struct value *val);
 879
 880 extern int record_latest_value (struct value *val);
 881
 882 extern void modify_field (struct type *type, gdb_byte *addr,
 883                           LONGEST fieldval, int bitpos, int bitsize);
 884
 885 extern void type_print (struct type *type, const char *varstring,
 886                         struct ui_file *stream, int show);
 887
 888 extern char *type_to_string (struct type *type);
 889
 890 extern gdb_byte *baseclass_addr (struct type *type, int index,
 891                                  gdb_byte *valaddr,
 892                                  struct value **valuep, int *errp);
 893
 894 extern void print_longest (struct ui_file *stream, int format,
 895                            int use_local, LONGEST val);
 896
 897 extern void print_floating (const gdb_byte *valaddr, struct type *type,
 898                             struct ui_file *stream);
 899
 900 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
 901                                     struct ui_file *stream);
 902
 903 extern void value_print (struct value *val, struct ui_file *stream,
 904                          const struct value_print_options *options);
 905
 906 extern void value_print_array_elements (struct value *val,
 907                                         struct ui_file *stream, int format,
 908                                         enum val_prettyformat pretty);
 909
 910 extern struct value *value_release_to_mark (struct value *mark);
 911
 912 extern void val_print (struct type *type, const gdb_byte *valaddr,
 913                        int embedded_offset, CORE_ADDR address,
 914                        struct ui_file *stream, int recurse,
 915                        const struct value *val,
 916                        const struct value_print_options *options,
 917                        const struct language_defn *language);
 918
 919 extern void common_val_print (struct value *val,
 920                               struct ui_file *stream, int recurse,
 921                               const struct value_print_options *options,
 922                               const struct language_defn *language);
 923
 924 extern int val_print_string (struct type *elttype, const char *encoding,
 925                              CORE_ADDR addr, int len,
 926                              struct ui_file *stream,
 927                              const struct value_print_options *options);
 928
 929 extern void print_variable_and_value (const char *name,
 930                                       struct symbol *var,
 931                                       struct frame_info *frame,
 932                                       struct ui_file *stream,
 933                                       int indent);
 934
 935 extern void typedef_print (struct type *type, struct symbol *news,
 936                            struct ui_file *stream);
 937
 938 extern char *internalvar_name (struct internalvar *var);
 939
 940 extern void preserve_values (struct objfile *);
 941
 942 /* From values.c */
 943
 944 extern struct value *value_copy (struct value *);
 945
 946 extern struct value *value_non_lval (struct value *);
 947
 948 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
 949
 950 /* From valops.c */
 951
 952 extern struct value *varying_to_slice (struct value *);
 953
 954 extern struct value *value_slice (struct value *, int, int);
 955
 956 extern struct value *value_literal_complex (struct value *, struct value *,
 957                                             struct type *);
 958
 959 extern struct value *find_function_in_inferior (const char *,
 960                                                 struct objfile **);
 961
 962 extern struct value *value_allocate_space_in_inferior (int);
 963
 964 extern struct value *value_subscripted_rvalue (struct value *array,
 965                                                LONGEST index, int lowerbound);
 966
 967 /* User function handler.  */
 968
 969 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
 970                                                const struct language_defn *language,
 971                                                void *cookie,
 972                                                int argc,
 973                                                struct value **argv);
 974
 975 void add_internal_function (const char *name, const char *doc,
 976                             internal_function_fn handler,
 977                             void *cookie);
 978
 979 struct value *call_internal_function (struct gdbarch *gdbarch,
 980                                       const struct language_defn *language,
 981                                       struct value *function,
 982                                       int argc, struct value **argv);
 983
 984 char *value_internal_function_name (struct value *);
 985
 986 #endif /* !defined (VALUE_H) */