gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2
   3    Copyright (C) 1986-2015 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 struct xmethod_worker;
  35
  36 /* Values can be partially 'optimized out' and/or 'unavailable'.
  37    These are distinct states and have different string representations
  38    and related error strings.
  39
  40    'unavailable' has a specific meaning in this context.  It means the
  41    value exists in the program (at the machine level), but GDB has no
  42    means to get to it.  Such a value is normally printed as
  43    <unavailable>.  Examples of how to end up with an unavailable value
  44    would be:
  45
  46     - We're inspecting a traceframe, and the memory or registers the
  47       debug information says the value lives on haven't been collected.
  48
  49     - We're inspecting a core dump, the memory or registers the debug
  50       information says the value lives aren't present in the dump
  51       (that is, we have a partial/trimmed core dump, or we don't fully
  52       understand/handle the core dump's format).
  53
  54     - We're doing live debugging, but the debug API has no means to
  55       get at where the value lives in the machine, like e.g., ptrace
  56       not having access to some register or register set.
  57
  58     - Any other similar scenario.
  59
  60   OTOH, "optimized out" is about what the compiler decided to generate
  61   (or not generate).  A chunk of a value that was optimized out does
  62   not actually exist in the program.  There's no way to get at it
  63   short of compiling the program differently.
  64
  65   A register that has not been saved in a frame is likewise considered
  66   optimized out, except not-saved registers have a different string
  67   representation and related error strings.  E.g., we'll print them as
  68   <not-saved> instead of <optimized out>, as in:
  69
  70     (gdb) p/x $rax
  71     $1 = <not saved>
  72     (gdb) info registers rax
  73     rax            <not saved>
  74
  75   If the debug info describes a variable as being in such a register,
  76   we'll still print the variable as <optimized out>.  IOW, <not saved>
  77   is reserved for inspecting registers at the machine level.
  78
  79   When comparing value contents, optimized out chunks, unavailable
  80   chunks, and valid contents data are all considered different.  See
  81   value_contents_eq for more info.
  82 */
  83
  84 /* The structure which defines the type of a value.  It should never
  85    be possible for a program lval value to survive over a call to the
  86    inferior (i.e. to be put into the history list or an internal
  87    variable).  */
  88
  89 struct value;
  90
  91 /* Values are stored in a chain, so that they can be deleted easily
  92    over calls to the inferior.  Values assigned to internal variables,
  93    put into the value history or exposed to Python are taken off this
  94    list.  */
  95
  96 struct value *value_next (struct value *);
  97
  98 /* Type of the value.  */
  99
 100 extern struct type *value_type (const struct value *);
 101
 102 /* This is being used to change the type of an existing value, that
 103    code should instead be creating a new value with the changed type
 104    (but possibly shared content).  */
 105
 106 extern void deprecated_set_value_type (struct value *value,
 107                                        struct type *type);
 108
 109 /* Only used for bitfields; number of bits contained in them.  */
 110
 111 extern int value_bitsize (const struct value *);
 112 extern void set_value_bitsize (struct value *, int bit);
 113
 114 /* Only used for bitfields; position of start of field.  For
 115    gdbarch_bits_big_endian=0 targets, it is the position of the LSB.  For
 116    gdbarch_bits_big_endian=1 targets, it is the position of the MSB.  */
 117
 118 extern int value_bitpos (const struct value *);
 119 extern void set_value_bitpos (struct value *, int bit);
 120
 121 /* Only used for bitfields; the containing value.  This allows a
 122    single read from the target when displaying multiple
 123    bitfields.  */
 124
 125 struct value *value_parent (struct value *);
 126 extern void set_value_parent (struct value *value, struct value *parent);
 127
 128 /* Describes offset of a value within lval of a structure in bytes.
 129    If lval == lval_memory, this is an offset to the address.  If lval
 130    == lval_register, this is a further offset from location.address
 131    within the registers structure.  Note also the member
 132    embedded_offset below.  */
 133
 134 extern int value_offset (const struct value *);
 135 extern void set_value_offset (struct value *, int offset);
 136
 137 /* The comment from "struct value" reads: ``Is it modifiable?  Only
 138    relevant if lval != not_lval.''.  Shouldn't the value instead be
 139    not_lval and be done with it?  */
 140
 141 extern int deprecated_value_modifiable (struct value *value);
 142
 143 /* If a value represents a C++ object, then the `type' field gives the
 144    object's compile-time type.  If the object actually belongs to some
 145    class derived from `type', perhaps with other base classes and
 146    additional members, then `type' is just a subobject of the real
 147    thing, and the full object is probably larger than `type' would
 148    suggest.
 149
 150    If `type' is a dynamic class (i.e. one with a vtable), then GDB can
 151    actually determine the object's run-time type by looking at the
 152    run-time type information in the vtable.  When this information is
 153    available, we may elect to read in the entire object, for several
 154    reasons:
 155
 156    - When printing the value, the user would probably rather see the
 157      full object, not just the limited portion apparent from the
 158      compile-time type.
 159
 160    - If `type' has virtual base classes, then even printing `type'
 161      alone may require reaching outside the `type' portion of the
 162      object to wherever the virtual base class has been stored.
 163
 164    When we store the entire object, `enclosing_type' is the run-time
 165    type -- the complete object -- and `embedded_offset' is the offset
 166    of `type' within that larger type, in bytes.  The value_contents()
 167    macro takes `embedded_offset' into account, so most GDB code
 168    continues to see the `type' portion of the value, just as the
 169    inferior would.
 170
 171    If `type' is a pointer to an object, then `enclosing_type' is a
 172    pointer to the object's run-time type, and `pointed_to_offset' is
 173    the offset in bytes from the full object to the pointed-to object
 174    -- that is, the value `embedded_offset' would have if we followed
 175    the pointer and fetched the complete object.  (I don't really see
 176    the point.  Why not just determine the run-time type when you
 177    indirect, and avoid the special case?  The contents don't matter
 178    until you indirect anyway.)
 179
 180    If we're not doing anything fancy, `enclosing_type' is equal to
 181    `type', and `embedded_offset' is zero, so everything works
 182    normally.  */
 183
 184 extern struct type *value_enclosing_type (struct value *);
 185 extern void set_value_enclosing_type (struct value *val,
 186                                       struct type *new_type);
 187
 188 /* Returns value_type or value_enclosing_type depending on
 189    value_print_options.objectprint.
 190
 191    If RESOLVE_SIMPLE_TYPES is 0 the enclosing type will be resolved
 192    only for pointers and references, else it will be returned
 193    for all the types (e.g. structures).  This option is useful
 194    to prevent retrieving enclosing type for the base classes fields.
 195
 196    REAL_TYPE_FOUND is used to inform whether the real type was found
 197    (or just static type was used).  The NULL may be passed if it is not
 198    necessary. */
 199
 200 extern struct type *value_actual_type (struct value *value,
 201                                        int resolve_simple_types,
 202                                        int *real_type_found);
 203
 204 extern int value_pointed_to_offset (struct value *value);
 205 extern void set_value_pointed_to_offset (struct value *value, int val);
 206 extern int value_embedded_offset (struct value *value);
 207 extern void set_value_embedded_offset (struct value *value, int val);
 208
 209 /* For lval_computed values, this structure holds functions used to
 210    retrieve and set the value (or portions of the value).
 211
 212    For each function, 'V' is the 'this' pointer: an lval_funcs
 213    function F may always assume that the V it receives is an
 214    lval_computed value, and has F in the appropriate slot of its
 215    lval_funcs structure.  */
 216
 217 struct lval_funcs
 218 {
 219   /* Fill in VALUE's contents.  This is used to "un-lazy" values.  If
 220      a problem arises in obtaining VALUE's bits, this function should
 221      call 'error'.  If it is NULL value_fetch_lazy on "un-lazy"
 222      non-optimized-out value is an internal error.  */
 223   void (*read) (struct value *v);
 224
 225   /* Handle an assignment TOVAL = FROMVAL by writing the value of
 226      FROMVAL to TOVAL's location.  The contents of TOVAL have not yet
 227      been updated.  If a problem arises in doing so, this function
 228      should call 'error'.  If it is NULL such TOVAL assignment is an error as
 229      TOVAL is not considered as an lvalue.  */
 230   void (*write) (struct value *toval, struct value *fromval);
 231
 232   /* If non-NULL, this is used to implement pointer indirection for
 233      this value.  This method may return NULL, in which case value_ind
 234      will fall back to ordinary indirection.  */
 235   struct value *(*indirect) (struct value *value);
 236
 237   /* If non-NULL, this is used to implement reference resolving for
 238      this value.  This method may return NULL, in which case coerce_ref
 239      will fall back to ordinary references resolving.  */
 240   struct value *(*coerce_ref) (const struct value *value);
 241
 242   /* If non-NULL, this is used to determine whether the indicated bits
 243      of VALUE are a synthetic pointer.  */
 244   int (*check_synthetic_pointer) (const struct value *value,
 245                                   int offset, int length);
 246
 247   /* Return a duplicate of VALUE's closure, for use in a new value.
 248      This may simply return the same closure, if VALUE's is
 249      reference-counted or statically allocated.
 250
 251      This may be NULL, in which case VALUE's closure is re-used in the
 252      new value.  */
 253   void *(*copy_closure) (const struct value *v);
 254
 255   /* Drop VALUE's reference to its closure.  Maybe this frees the
 256      closure; maybe this decrements a reference count; maybe the
 257      closure is statically allocated and this does nothing.
 258
 259      This may be NULL, in which case no action is taken to free
 260      VALUE's closure.  */
 261   void (*free_closure) (struct value *v);
 262 };
 263
 264 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
 265    and closure CLOSURE.  */
 266
 267 extern struct value *allocate_computed_value (struct type *type,
 268                                               const struct lval_funcs *funcs,
 269                                               void *closure);
 270
 271 /* Helper function to check the validity of some bits of a value.
 272
 273    If TYPE represents some aggregate type (e.g., a structure), return 1.
 274
 275    Otherwise, any of the bytes starting at OFFSET and extending for
 276    TYPE_LENGTH(TYPE) bytes are invalid, print a message to STREAM and
 277    return 0.  The checking is done using FUNCS.
 278
 279    Otherwise, return 1.  */
 280
 281 extern int valprint_check_validity (struct ui_file *stream, struct type *type,
 282                                     int embedded_offset,
 283                                     const struct value *val);
 284
 285 extern struct value *allocate_optimized_out_value (struct type *type);
 286
 287 /* If VALUE is lval_computed, return its lval_funcs structure.  */
 288
 289 extern const struct lval_funcs *value_computed_funcs (const struct value *);
 290
 291 /* If VALUE is lval_computed, return its closure.  The meaning of the
 292    returned value depends on the functions VALUE uses.  */
 293
 294 extern void *value_computed_closure (const struct value *value);
 295
 296 /* If zero, contents of this value are in the contents field.  If
 297    nonzero, contents are in inferior.  If the lval field is lval_memory,
 298    the contents are in inferior memory at location.address plus offset.
 299    The lval field may also be lval_register.
 300
 301    WARNING: This field is used by the code which handles watchpoints
 302    (see breakpoint.c) to decide whether a particular value can be
 303    watched by hardware watchpoints.  If the lazy flag is set for some
 304    member of a value chain, it is assumed that this member of the
 305    chain doesn't need to be watched as part of watching the value
 306    itself.  This is how GDB avoids watching the entire struct or array
 307    when the user wants to watch a single struct member or array
 308    element.  If you ever change the way lazy flag is set and reset, be
 309    sure to consider this use as well!  */
 310
 311 extern int value_lazy (struct value *);
 312 extern void set_value_lazy (struct value *value, int val);
 313
 314 extern int value_stack (struct value *);
 315 extern void set_value_stack (struct value *value, int val);
 316
 317 /* Throw an error complaining that the value has been optimized
 318    out.  */
 319
 320 extern void error_value_optimized_out (void);
 321
 322 /* value_contents() and value_contents_raw() both return the address
 323    of the gdb buffer used to hold a copy of the contents of the lval.
 324    value_contents() is used when the contents of the buffer are needed
 325    -- it uses value_fetch_lazy() to load the buffer from the process
 326    being debugged if it hasn't already been loaded
 327    (value_contents_writeable() is used when a writeable but fetched
 328    buffer is required)..  value_contents_raw() is used when data is
 329    being stored into the buffer, or when it is certain that the
 330    contents of the buffer are valid.
 331
 332    Note: The contents pointer is adjusted by the offset required to
 333    get to the real subobject, if the value happens to represent
 334    something embedded in a larger run-time object.  */
 335
 336 extern gdb_byte *value_contents_raw (struct value *);
 337
 338 /* Actual contents of the value.  For use of this value; setting it
 339    uses the stuff above.  Not valid if lazy is nonzero.  Target
 340    byte-order.  We force it to be aligned properly for any possible
 341    value.  Note that a value therefore extends beyond what is
 342    declared here.  */
 343
 344 extern const gdb_byte *value_contents (struct value *);
 345 extern gdb_byte *value_contents_writeable (struct value *);
 346
 347 /* The ALL variants of the above two macros do not adjust the returned
 348    pointer by the embedded_offset value.  */
 349
 350 extern gdb_byte *value_contents_all_raw (struct value *);
 351 extern const gdb_byte *value_contents_all (struct value *);
 352
 353 /* Like value_contents_all, but does not require that the returned
 354    bits be valid.  This should only be used in situations where you
 355    plan to check the validity manually.  */
 356 extern const gdb_byte *value_contents_for_printing (struct value *value);
 357
 358 /* Like value_contents_for_printing, but accepts a constant value
 359    pointer.  Unlike value_contents_for_printing however, the pointed
 360    value must _not_ be lazy.  */
 361 extern const gdb_byte *
 362   value_contents_for_printing_const (const struct value *value);
 363
 364 extern int value_fetch_lazy (struct value *val);
 365
 366 /* If nonzero, this is the value of a variable which does not actually
 367    exist in the program, at least partially.  If the value is lazy,
 368    this may fetch it now.  */
 369 extern int value_optimized_out (struct value *value);
 370
 371 /* Given a value, return true if any of the contents bits starting at
 372    OFFSET and extending for LENGTH bits is optimized out, false
 373    otherwise.  */
 374
 375 extern int value_bits_any_optimized_out (const struct value *value,
 376                                          int bit_offset, int bit_length);
 377
 378 /* Like value_optimized_out, but return true iff the whole value is
 379    optimized out.  */
 380 extern int value_entirely_optimized_out (struct value *value);
 381
 382 /* Mark VALUE's content bytes starting at OFFSET and extending for
 383    LENGTH bytes as optimized out.  */
 384
 385 extern void mark_value_bytes_optimized_out (struct value *value,
 386                                             int offset, int length);
 387
 388 /* Mark VALUE's content bits starting at OFFSET and extending for
 389    LENGTH bits as optimized out.  */
 390
 391 extern void mark_value_bits_optimized_out (struct value *value,
 392                                            int offset, int length);
 393
 394 /* Set or return field indicating whether a variable is initialized or
 395    not, based on debugging information supplied by the compiler.
 396    1 = initialized; 0 = uninitialized.  */
 397 extern int value_initialized (struct value *);
 398 extern void set_value_initialized (struct value *, int);
 399
 400 /* Set COMPONENT's location as appropriate for a component of WHOLE
 401    --- regardless of what kind of lvalue WHOLE is.  */
 402 extern void set_value_component_location (struct value *component,
 403                                           const struct value *whole);
 404
 405 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
 406    single value might have multiple LVALs), this hacked interface is
 407    limited to just the first PIECE.  Expect further change.  */
 408 /* Type of value; either not an lval, or one of the various different
 409    possible kinds of lval.  */
 410 extern enum lval_type *deprecated_value_lval_hack (struct value *);
 411 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
 412
 413 /* Like VALUE_LVAL, except the parameter can be const.  */
 414 extern enum lval_type value_lval_const (const struct value *value);
 415
 416 /* If lval == lval_memory, return the address in the inferior.  If
 417    lval == lval_register, return the byte offset into the registers
 418    structure.  Otherwise, return 0.  The returned address
 419    includes the offset, if any.  */
 420 extern CORE_ADDR value_address (const struct value *);
 421
 422 /* Like value_address, except the result does not include value's
 423    offset.  */
 424 extern CORE_ADDR value_raw_address (struct value *);
 425
 426 /* Set the address of a value.  */
 427 extern void set_value_address (struct value *, CORE_ADDR);
 428
 429 /* Pointer to internal variable.  */
 430 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
 431 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
 432
 433 /* Frame register value is relative to.  This will be described in the
 434    lval enum above as "lval_register".  */
 435 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
 436 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
 437
 438 /* Register number if the value is from a register.  */
 439 extern short *deprecated_value_regnum_hack (struct value *);
 440 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
 441
 442 /* Return value after lval_funcs->coerce_ref (after check_typedef).  Return
 443    NULL if lval_funcs->coerce_ref is not applicable for whatever reason.  */
 444
 445 extern struct value *coerce_ref_if_computed (const struct value *arg);
 446
 447 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
 448    ENC_TYPE is the new enclosing type that should be set.  ORIGINAL_TYPE and
 449    ORIGINAL_VAL are the type and value of the original reference or pointer.
 450
 451    Note, that VALUE is modified by this function.
 452
 453    It is a common implementation for coerce_ref and value_ind.  */
 454
 455 extern struct value * readjust_indirect_value_type (struct value *value,
 456                                                     struct type *enc_type,
 457                                                     struct type *original_type,
 458                                                     struct value *original_val);
 459
 460 /* Convert a REF to the object referenced.  */
 461
 462 extern struct value *coerce_ref (struct value *value);
 463
 464 /* If ARG is an array, convert it to a pointer.
 465    If ARG is a function, convert it to a function pointer.
 466
 467    References are dereferenced.  */
 468
 469 extern struct value *coerce_array (struct value *value);
 470
 471 /* Given a value, determine whether the bits starting at OFFSET and
 472    extending for LENGTH bits are a synthetic pointer.  */
 473
 474 extern int value_bits_synthetic_pointer (const struct value *value,
 475                                          int offset, int length);
 476
 477 /* Given a value, determine whether the contents bytes starting at
 478    OFFSET and extending for LENGTH bytes are available.  This returns
 479    nonzero if all bytes in the given range are available, zero if any
 480    byte is unavailable.  */
 481
 482 extern int value_bytes_available (const struct value *value,
 483                                   int offset, int length);
 484
 485 /* Given a value, determine whether the contents bits starting at
 486    OFFSET and extending for LENGTH bits are available.  This returns
 487    nonzero if all bits in the given range are available, zero if any
 488    bit is unavailable.  */
 489
 490 extern int value_bits_available (const struct value *value,
 491                                  int offset, int length);
 492
 493 /* Like value_bytes_available, but return false if any byte in the
 494    whole object is unavailable.  */
 495 extern int value_entirely_available (struct value *value);
 496
 497 /* Like value_entirely_available, but return false if any byte in the
 498    whole object is available.  */
 499 extern int value_entirely_unavailable (struct value *value);
 500
 501 /* Mark VALUE's content bytes starting at OFFSET and extending for
 502    LENGTH bytes as unavailable.  */
 503
 504 extern void mark_value_bytes_unavailable (struct value *value,
 505                                           int offset, int length);
 506
 507 /* Mark VALUE's content bits starting at OFFSET and extending for
 508    LENGTH bits as unavailable.  */
 509
 510 extern void mark_value_bits_unavailable (struct value *value,
 511                                          int offset, int length);
 512
 513 /* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
 514    LENGTH bytes of VAL2's contents starting at OFFSET2.
 515
 516    Note that "contents" refers to the whole value's contents
 517    (value_contents_all), without any embedded offset adjustment.  For
 518    example, to compare a complete object value with itself, including
 519    its enclosing type chunk, you'd do:
 520
 521      int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
 522      value_contents_eq (val, 0, val, 0, len);
 523
 524    Returns true iff the set of available/valid contents match.
 525
 526    Optimized-out contents are equal to optimized-out contents, and are
 527    not equal to non-optimized-out contents.
 528
 529    Unavailable contente are equal to unavailable contents, and are not
 530    equal to non-unavailable contents.
 531
 532    For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
 533    represent different available/valid bytes, in a value with length
 534    16:
 535
 536      offset:   0   4   8   12  16
 537      contents: xxxxVVVVxxxxVVZZ
 538
 539    then:
 540
 541      value_contents_eq(val, 0, val, 8, 6) => 1
 542      value_contents_eq(val, 0, val, 4, 4) => 0
 543      value_contents_eq(val, 0, val, 8, 8) => 0
 544      value_contents_eq(val, 4, val, 12, 2) => 1
 545      value_contents_eq(val, 4, val, 12, 4) => 0
 546      value_contents_eq(val, 3, val, 4, 4) => 0
 547
 548    If 'x's represent an unavailable byte, 'o' represents an optimized
 549    out byte, in a value with length 8:
 550
 551      offset:   0   4   8
 552      contents: xxxxoooo
 553
 554    then:
 555
 556      value_contents_eq(val, 0, val, 2, 2) => 1
 557      value_contents_eq(val, 4, val, 6, 2) => 1
 558      value_contents_eq(val, 0, val, 4, 4) => 0
 559
 560    We only know whether a value chunk is unavailable or optimized out
 561    if we've tried to read it.  As this routine is used by printing
 562    routines, which may be printing values in the value history, long
 563    after the inferior is gone, it works with const values.  Therefore,
 564    this routine must not be called with lazy values.  */
 565
 566 extern int value_contents_eq (const struct value *val1, int offset1,
 567                               const struct value *val2, int offset2,
 568                               int length);
 569
 570 /* Read LENGTH bytes of memory starting at MEMADDR into BUFFER, which
 571    is (or will be copied to) VAL's contents buffer offset by
 572    EMBEDDED_OFFSET (that is, to &VAL->contents[EMBEDDED_OFFSET]).
 573    Marks value contents ranges as unavailable if the corresponding
 574    memory is likewise unavailable.  STACK indicates whether the memory
 575    is known to be stack memory.  */
 576
 577 extern void read_value_memory (struct value *val, int embedded_offset,
 578                                int stack, CORE_ADDR memaddr,
 579                                gdb_byte *buffer, size_t length);
 580
 581 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
 582    into each element of a new vector value with VECTOR_TYPE.  */
 583
 584 struct value *value_vector_widen (struct value *scalar_value,
 585                                   struct type *vector_type);
 586
 587 \f
 588
 589 #include "symtab.h"
 590 #include "gdbtypes.h"
 591 #include "expression.h"
 592
 593 struct frame_info;
 594 struct fn_field;
 595
 596 extern int print_address_demangle (const struct value_print_options *,
 597                                    struct gdbarch *, CORE_ADDR,
 598                                    struct ui_file *, int);
 599
 600 extern LONGEST value_as_long (struct value *val);
 601 extern DOUBLEST value_as_double (struct value *val);
 602 extern CORE_ADDR value_as_address (struct value *val);
 603
 604 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
 605 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
 606                                int *invp);
 607 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
 608
 609 extern LONGEST unpack_field_as_long (struct type *type,
 610                                      const gdb_byte *valaddr,
 611                                      int fieldno);
 612 extern int unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
 613                                 int embedded_offset, int fieldno,
 614                                 const struct value *val, LONGEST *result);
 615
 616 extern void unpack_value_bitfield (struct value *dest_val,
 617                                    int bitpos, int bitsize,
 618                                    const gdb_byte *valaddr, int embedded_offset,
 619                                    const struct value *val);
 620
 621 extern struct value *value_field_bitfield (struct type *type, int fieldno,
 622                                            const gdb_byte *valaddr,
 623                                            int embedded_offset,
 624                                            const struct value *val);
 625
 626 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
 627
 628 extern struct value *value_from_longest (struct type *type, LONGEST num);
 629 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
 630 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
 631 extern struct value *value_from_double (struct type *type, DOUBLEST num);
 632 extern struct value *value_from_decfloat (struct type *type,
 633                                           const gdb_byte *decbytes);
 634 extern struct value *value_from_history_ref (const char *, const char **);
 635
 636 extern struct value *value_at (struct type *type, CORE_ADDR addr);
 637 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
 638
 639 extern struct value *value_from_contents_and_address_unresolved
 640      (struct type *, const gdb_byte *, CORE_ADDR);
 641 extern struct value *value_from_contents_and_address (struct type *,
 642                                                       const gdb_byte *,
 643                                                       CORE_ADDR);
 644 extern struct value *value_from_contents (struct type *, const gdb_byte *);
 645
 646 extern struct value *default_value_from_register (struct gdbarch *gdbarch,
 647                                                   struct type *type,
 648                                                   int regnum,
 649                                                   struct frame_id frame_id);
 650
 651 extern void read_frame_register_value (struct value *value,
 652                                        struct frame_info *frame);
 653
 654 extern struct value *value_from_register (struct type *type, int regnum,
 655                                           struct frame_info *frame);
 656
 657 extern CORE_ADDR address_from_register (int regnum,
 658                                         struct frame_info *frame);
 659
 660 extern struct value *value_of_variable (struct symbol *var,
 661                                         const struct block *b);
 662
 663 extern struct value *address_of_variable (struct symbol *var,
 664                                           const struct block *b);
 665
 666 extern struct value *value_of_register (int regnum, struct frame_info *frame);
 667
 668 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
 669
 670 extern int symbol_read_needs_frame (struct symbol *);
 671
 672 extern struct value *read_var_value (struct symbol *var,
 673                                      struct frame_info *frame);
 674
 675 extern struct value *default_read_var_value (struct symbol *var,
 676                                              struct frame_info *frame);
 677
 678 extern struct value *allocate_value (struct type *type);
 679 extern struct value *allocate_value_lazy (struct type *type);
 680 extern void value_contents_copy (struct value *dst, int dst_offset,
 681                                  struct value *src, int src_offset,
 682                                  int length);
 683 extern void value_contents_copy_raw (struct value *dst, int dst_offset,
 684                                      struct value *src, int src_offset,
 685                                      int length);
 686
 687 extern struct value *allocate_repeat_value (struct type *type, int count);
 688
 689 extern struct value *value_mark (void);
 690
 691 extern void value_free_to_mark (struct value *mark);
 692
 693 extern struct value *value_cstring (char *ptr, ssize_t len,
 694                                     struct type *char_type);
 695 extern struct value *value_string (char *ptr, ssize_t len,
 696                                    struct type *char_type);
 697
 698 extern struct value *value_array (int lowbound, int highbound,
 699                                   struct value **elemvec);
 700
 701 extern struct value *value_concat (struct value *arg1, struct value *arg2);
 702
 703 extern struct value *value_binop (struct value *arg1, struct value *arg2,
 704                                   enum exp_opcode op);
 705
 706 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
 707
 708 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
 709
 710 extern int value_must_coerce_to_target (struct value *arg1);
 711
 712 extern struct value *value_coerce_to_target (struct value *arg1);
 713
 714 extern struct value *value_coerce_array (struct value *arg1);
 715
 716 extern struct value *value_coerce_function (struct value *arg1);
 717
 718 extern struct value *value_ind (struct value *arg1);
 719
 720 extern struct value *value_addr (struct value *arg1);
 721
 722 extern struct value *value_ref (struct value *arg1);
 723
 724 extern struct value *value_assign (struct value *toval,
 725                                    struct value *fromval);
 726
 727 extern struct value *value_pos (struct value *arg1);
 728
 729 extern struct value *value_neg (struct value *arg1);
 730
 731 extern struct value *value_complement (struct value *arg1);
 732
 733 extern struct value *value_struct_elt (struct value **argp,
 734                                        struct value **args,
 735                                        const char *name, int *static_memfuncp,
 736                                        const char *err);
 737
 738 extern struct value *value_struct_elt_bitpos (struct value **argp,
 739                                               int bitpos,
 740                                               struct type *field_type,
 741                                               const char *err);
 742
 743 extern struct value *value_aggregate_elt (struct type *curtype,
 744                                           const char *name,
 745                                           struct type *expect_type,
 746                                           int want_address,
 747                                           enum noside noside);
 748
 749 extern struct value *value_static_field (struct type *type, int fieldno);
 750
 751 enum oload_search_type { NON_METHOD, METHOD, BOTH };
 752
 753 extern int find_overload_match (struct value **args, int nargs,
 754                                 const char *name,
 755                                 enum oload_search_type method,
 756                                 struct value **objp, struct symbol *fsym,
 757                                 struct value **valp, struct symbol **symp,
 758                                 int *staticp, const int no_adl,
 759                                 enum noside noside);
 760
 761 extern struct value *value_field (struct value *arg1, int fieldno);
 762
 763 extern struct value *value_primitive_field (struct value *arg1, int offset,
 764                                             int fieldno,
 765                                             struct type *arg_type);
 766
 767
 768 extern struct type *value_rtti_indirect_type (struct value *, int *, int *,
 769                                               int *);
 770
 771 extern struct value *value_full_object (struct value *, struct type *, int,
 772                                         int, int);
 773
 774 extern struct value *value_cast_pointers (struct type *, struct value *, int);
 775
 776 extern struct value *value_cast (struct type *type, struct value *arg2);
 777
 778 extern struct value *value_reinterpret_cast (struct type *type,
 779                                              struct value *arg);
 780
 781 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
 782
 783 extern struct value *value_zero (struct type *type, enum lval_type lv);
 784
 785 extern struct value *value_one (struct type *type);
 786
 787 extern struct value *value_repeat (struct value *arg1, int count);
 788
 789 extern struct value *value_subscript (struct value *array, LONGEST index);
 790
 791 extern struct value *value_bitstring_subscript (struct type *type,
 792                                                 struct value *bitstring,
 793                                                 LONGEST index);
 794
 795 extern struct value *register_value_being_returned (struct type *valtype,
 796                                                     struct regcache *retbuf);
 797
 798 extern int value_in (struct value *element, struct value *set);
 799
 800 extern int value_bit_index (struct type *type, const gdb_byte *addr,
 801                             int index);
 802
 803 extern enum return_value_convention
 804 struct_return_convention (struct gdbarch *gdbarch, struct value *function,
 805                           struct type *value_type);
 806
 807 extern int using_struct_return (struct gdbarch *gdbarch,
 808                                 struct value *function,
 809                                 struct type *value_type);
 810
 811 extern struct value *evaluate_expression (struct expression *exp);
 812
 813 extern struct value *evaluate_type (struct expression *exp);
 814
 815 extern struct value *evaluate_subexp (struct type *expect_type,
 816                                       struct expression *exp,
 817                                       int *pos, enum noside noside);
 818
 819 extern struct value *evaluate_subexpression_type (struct expression *exp,
 820                                                   int subexp);
 821
 822 extern void fetch_subexp_value (struct expression *exp, int *pc,
 823                                 struct value **valp, struct value **resultp,
 824                                 struct value **val_chain,
 825                                 int preserve_errors);
 826
 827 extern char *extract_field_op (struct expression *exp, int *subexp);
 828
 829 extern struct value *evaluate_subexp_with_coercion (struct expression *,
 830                                                     int *, enum noside);
 831
 832 extern struct value *parse_and_eval (const char *exp);
 833
 834 extern struct value *parse_to_comma_and_eval (const char **expp);
 835
 836 extern struct type *parse_and_eval_type (char *p, int length);
 837
 838 extern CORE_ADDR parse_and_eval_address (const char *exp);
 839
 840 extern LONGEST parse_and_eval_long (const char *exp);
 841
 842 extern void unop_promote (const struct language_defn *language,
 843                           struct gdbarch *gdbarch,
 844                           struct value **arg1);
 845
 846 extern void binop_promote (const struct language_defn *language,
 847                            struct gdbarch *gdbarch,
 848                            struct value **arg1, struct value **arg2);
 849
 850 extern struct value *access_value_history (int num);
 851
 852 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
 853                                            struct internalvar *var);
 854
 855 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
 856
 857 extern void set_internalvar (struct internalvar *var, struct value *val);
 858
 859 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
 860
 861 extern void set_internalvar_string (struct internalvar *var,
 862                                     const char *string);
 863
 864 extern void clear_internalvar (struct internalvar *var);
 865
 866 extern void set_internalvar_component (struct internalvar *var,
 867                                        int offset,
 868                                        int bitpos, int bitsize,
 869                                        struct value *newvalue);
 870
 871 extern struct internalvar *lookup_only_internalvar (const char *name);
 872
 873 extern struct internalvar *create_internalvar (const char *name);
 874
 875 extern VEC (char_ptr) *complete_internalvar (const char *name);
 876
 877 /* An internalvar can be dynamically computed by supplying a vector of
 878    function pointers to perform various operations.  */
 879
 880 struct internalvar_funcs
 881 {
 882   /* Compute the value of the variable.  The DATA argument passed to
 883      the function is the same argument that was passed to
 884      `create_internalvar_type_lazy'.  */
 885
 886   struct value *(*make_value) (struct gdbarch *arch,
 887                                struct internalvar *var,
 888                                void *data);
 889
 890   /* Update the agent expression EXPR with bytecode to compute the
 891      value.  VALUE is the agent value we are updating.  The DATA
 892      argument passed to this function is the same argument that was
 893      passed to `create_internalvar_type_lazy'.  If this pointer is
 894      NULL, then the internalvar cannot be compiled to an agent
 895      expression.  */
 896
 897   void (*compile_to_ax) (struct internalvar *var,
 898                          struct agent_expr *expr,
 899                          struct axs_value *value,
 900                          void *data);
 901
 902   /* If non-NULL, this is called to destroy DATA.  The DATA argument
 903      passed to this function is the same argument that was passed to
 904      `create_internalvar_type_lazy'.  */
 905
 906   void (*destroy) (void *data);
 907 };
 908
 909 extern struct internalvar *create_internalvar_type_lazy (const char *name,
 910                                 const struct internalvar_funcs *funcs,
 911                                 void *data);
 912
 913 /* Compile an internal variable to an agent expression.  VAR is the
 914    variable to compile; EXPR and VALUE are the agent expression we are
 915    updating.  This will return 0 if there is no known way to compile
 916    VAR, and 1 if VAR was successfully compiled.  It may also throw an
 917    exception on error.  */
 918
 919 extern int compile_internalvar_to_ax (struct internalvar *var,
 920                                       struct agent_expr *expr,
 921                                       struct axs_value *value);
 922
 923 extern struct internalvar *lookup_internalvar (const char *name);
 924
 925 extern int value_equal (struct value *arg1, struct value *arg2);
 926
 927 extern int value_equal_contents (struct value *arg1, struct value *arg2);
 928
 929 extern int value_less (struct value *arg1, struct value *arg2);
 930
 931 extern int value_logical_not (struct value *arg1);
 932
 933 /* C++ */
 934
 935 extern struct value *value_of_this (const struct language_defn *lang);
 936
 937 extern struct value *value_of_this_silent (const struct language_defn *lang);
 938
 939 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
 940                                     enum exp_opcode op,
 941                                     enum exp_opcode otherop,
 942                                     enum noside noside);
 943
 944 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
 945                                    enum noside noside);
 946
 947 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
 948                                      int j, struct type *type, int offset);
 949
 950 extern int binop_types_user_defined_p (enum exp_opcode op,
 951                                        struct type *type1,
 952                                        struct type *type2);
 953
 954 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
 955                                  struct value *arg2);
 956
 957 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
 958
 959 extern int destructor_name_p (const char *name, struct type *type);
 960
 961 extern void value_incref (struct value *val);
 962
 963 extern void value_free (struct value *val);
 964
 965 extern void free_all_values (void);
 966
 967 extern void free_value_chain (struct value *v);
 968
 969 extern void release_value (struct value *val);
 970
 971 extern void release_value_or_incref (struct value *val);
 972
 973 extern int record_latest_value (struct value *val);
 974
 975 extern void modify_field (struct type *type, gdb_byte *addr,
 976                           LONGEST fieldval, int bitpos, int bitsize);
 977
 978 extern void type_print (struct type *type, const char *varstring,
 979                         struct ui_file *stream, int show);
 980
 981 extern char *type_to_string (struct type *type);
 982
 983 extern gdb_byte *baseclass_addr (struct type *type, int index,
 984                                  gdb_byte *valaddr,
 985                                  struct value **valuep, int *errp);
 986
 987 extern void print_longest (struct ui_file *stream, int format,
 988                            int use_local, LONGEST val);
 989
 990 extern void print_floating (const gdb_byte *valaddr, struct type *type,
 991                             struct ui_file *stream);
 992
 993 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
 994                                     struct ui_file *stream);
 995
 996 extern void value_print (struct value *val, struct ui_file *stream,
 997                          const struct value_print_options *options);
 998
 999 extern void value_print_array_elements (struct value *val,
1000                                         struct ui_file *stream, int format,
1001                                         enum val_prettyformat pretty);
1002
1003 extern struct value *value_release_to_mark (struct value *mark);
1004
1005 extern void val_print (struct type *type, const gdb_byte *valaddr,
1006                        int embedded_offset, CORE_ADDR address,
1007                        struct ui_file *stream, int recurse,
1008                        const struct value *val,
1009                        const struct value_print_options *options,
1010                        const struct language_defn *language);
1011
1012 extern void common_val_print (struct value *val,
1013                               struct ui_file *stream, int recurse,
1014                               const struct value_print_options *options,
1015                               const struct language_defn *language);
1016
1017 extern int val_print_string (struct type *elttype, const char *encoding,
1018                              CORE_ADDR addr, int len,
1019                              struct ui_file *stream,
1020                              const struct value_print_options *options);
1021
1022 extern void print_variable_and_value (const char *name,
1023                                       struct symbol *var,
1024                                       struct frame_info *frame,
1025                                       struct ui_file *stream,
1026                                       int indent);
1027
1028 extern void typedef_print (struct type *type, struct symbol *news,
1029                            struct ui_file *stream);
1030
1031 extern char *internalvar_name (struct internalvar *var);
1032
1033 extern void preserve_values (struct objfile *);
1034
1035 /* From values.c */
1036
1037 extern struct value *value_copy (struct value *);
1038
1039 extern struct value *value_non_lval (struct value *);
1040
1041 extern void value_force_lval (struct value *, CORE_ADDR);
1042
1043 extern struct value *make_cv_value (int, int, struct value *);
1044
1045 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
1046
1047 /* From valops.c */
1048
1049 extern struct value *varying_to_slice (struct value *);
1050
1051 extern struct value *value_slice (struct value *, int, int);
1052
1053 extern struct value *value_literal_complex (struct value *, struct value *,
1054                                             struct type *);
1055
1056 extern struct value *find_function_in_inferior (const char *,
1057                                                 struct objfile **);
1058
1059 extern struct value *value_allocate_space_in_inferior (int);
1060
1061 extern struct value *value_subscripted_rvalue (struct value *array,
1062                                                LONGEST index, int lowerbound);
1063
1064 /* User function handler.  */
1065
1066 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
1067                                                const struct language_defn *language,
1068                                                void *cookie,
1069                                                int argc,
1070                                                struct value **argv);
1071
1072 void add_internal_function (const char *name, const char *doc,
1073                             internal_function_fn handler,
1074                             void *cookie);
1075
1076 struct value *call_internal_function (struct gdbarch *gdbarch,
1077                                       const struct language_defn *language,
1078                                       struct value *function,
1079                                       int argc, struct value **argv);
1080
1081 char *value_internal_function_name (struct value *);
1082
1083 extern struct value *value_of_xmethod (struct xmethod_worker *);
1084
1085 extern struct type *result_type_of_xmethod (struct value *method,
1086                                             int argc, struct value **argv);
1087
1088 extern struct value *call_xmethod (struct value *method,
1089                                    int argc, struct value **argv);
1090
1091 #endif /* !defined (VALUE_H) */