gdb/value.h

   1 /* Definitions for values of C expressions, for GDB.
   2
   3    Copyright (C) 1986-2016 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 (const struct value *);
  97
  98 /* Type of the value.  */
  99
 100 extern struct type *value_type (const struct value *);
 101
 102 /* Return the gdbarch associated with the value. */
 103
 104 extern struct gdbarch *get_value_arch (const struct value *value);
 105
 106 /* This is being used to change the type of an existing value, that
 107    code should instead be creating a new value with the changed type
 108    (but possibly shared content).  */
 109
 110 extern void deprecated_set_value_type (struct value *value,
 111                                        struct type *type);
 112
 113 /* Only used for bitfields; number of bits contained in them.  */
 114
 115 extern int value_bitsize (const struct value *);
 116 extern void set_value_bitsize (struct value *, int bit);
 117
 118 /* Only used for bitfields; position of start of field.  For
 119    gdbarch_bits_big_endian=0 targets, it is the position of the LSB.  For
 120    gdbarch_bits_big_endian=1 targets, it is the position of the MSB.  */
 121
 122 extern int value_bitpos (const struct value *);
 123 extern void set_value_bitpos (struct value *, int bit);
 124
 125 /* Only used for bitfields; the containing value.  This allows a
 126    single read from the target when displaying multiple
 127    bitfields.  */
 128
 129 struct value *value_parent (const struct value *);
 130 extern void set_value_parent (struct value *value, struct value *parent);
 131
 132 /* Describes offset of a value within lval of a structure in bytes.
 133    If lval == lval_memory, this is an offset to the address.  If lval
 134    == lval_register, this is a further offset from location.address
 135    within the registers structure.  Note also the member
 136    embedded_offset below.  */
 137
 138 extern int value_offset (const struct value *);
 139 extern void set_value_offset (struct value *, int offset);
 140
 141 /* The comment from "struct value" reads: ``Is it modifiable?  Only
 142    relevant if lval != not_lval.''.  Shouldn't the value instead be
 143    not_lval and be done with it?  */
 144
 145 extern int deprecated_value_modifiable (const struct value *value);
 146
 147 /* If a value represents a C++ object, then the `type' field gives the
 148    object's compile-time type.  If the object actually belongs to some
 149    class derived from `type', perhaps with other base classes and
 150    additional members, then `type' is just a subobject of the real
 151    thing, and the full object is probably larger than `type' would
 152    suggest.
 153
 154    If `type' is a dynamic class (i.e. one with a vtable), then GDB can
 155    actually determine the object's run-time type by looking at the
 156    run-time type information in the vtable.  When this information is
 157    available, we may elect to read in the entire object, for several
 158    reasons:
 159
 160    - When printing the value, the user would probably rather see the
 161      full object, not just the limited portion apparent from the
 162      compile-time type.
 163
 164    - If `type' has virtual base classes, then even printing `type'
 165      alone may require reaching outside the `type' portion of the
 166      object to wherever the virtual base class has been stored.
 167
 168    When we store the entire object, `enclosing_type' is the run-time
 169    type -- the complete object -- and `embedded_offset' is the offset
 170    of `type' within that larger type, in bytes.  The value_contents()
 171    macro takes `embedded_offset' into account, so most GDB code
 172    continues to see the `type' portion of the value, just as the
 173    inferior would.
 174
 175    If `type' is a pointer to an object, then `enclosing_type' is a
 176    pointer to the object's run-time type, and `pointed_to_offset' is
 177    the offset in bytes from the full object to the pointed-to object
 178    -- that is, the value `embedded_offset' would have if we followed
 179    the pointer and fetched the complete object.  (I don't really see
 180    the point.  Why not just determine the run-time type when you
 181    indirect, and avoid the special case?  The contents don't matter
 182    until you indirect anyway.)
 183
 184    If we're not doing anything fancy, `enclosing_type' is equal to
 185    `type', and `embedded_offset' is zero, so everything works
 186    normally.  */
 187
 188 extern struct type *value_enclosing_type (const struct value *);
 189 extern void set_value_enclosing_type (struct value *val,
 190                                       struct type *new_type);
 191
 192 /* Returns value_type or value_enclosing_type depending on
 193    value_print_options.objectprint.
 194
 195    If RESOLVE_SIMPLE_TYPES is 0 the enclosing type will be resolved
 196    only for pointers and references, else it will be returned
 197    for all the types (e.g. structures).  This option is useful
 198    to prevent retrieving enclosing type for the base classes fields.
 199
 200    REAL_TYPE_FOUND is used to inform whether the real type was found
 201    (or just static type was used).  The NULL may be passed if it is not
 202    necessary. */
 203
 204 extern struct type *value_actual_type (struct value *value,
 205                                        int resolve_simple_types,
 206                                        int *real_type_found);
 207
 208 extern int value_pointed_to_offset (const struct value *value);
 209 extern void set_value_pointed_to_offset (struct value *value, int val);
 210 extern int value_embedded_offset (const struct value *value);
 211 extern void set_value_embedded_offset (struct value *value, int val);
 212
 213 /* For lval_computed values, this structure holds functions used to
 214    retrieve and set the value (or portions of the value).
 215
 216    For each function, 'V' is the 'this' pointer: an lval_funcs
 217    function F may always assume that the V it receives is an
 218    lval_computed value, and has F in the appropriate slot of its
 219    lval_funcs structure.  */
 220
 221 struct lval_funcs
 222 {
 223   /* Fill in VALUE's contents.  This is used to "un-lazy" values.  If
 224      a problem arises in obtaining VALUE's bits, this function should
 225      call 'error'.  If it is NULL value_fetch_lazy on "un-lazy"
 226      non-optimized-out value is an internal error.  */
 227   void (*read) (struct value *v);
 228
 229   /* Handle an assignment TOVAL = FROMVAL by writing the value of
 230      FROMVAL to TOVAL's location.  The contents of TOVAL have not yet
 231      been updated.  If a problem arises in doing so, this function
 232      should call 'error'.  If it is NULL such TOVAL assignment is an error as
 233      TOVAL is not considered as an lvalue.  */
 234   void (*write) (struct value *toval, struct value *fromval);
 235
 236   /* If non-NULL, this is used to implement pointer indirection for
 237      this value.  This method may return NULL, in which case value_ind
 238      will fall back to ordinary indirection.  */
 239   struct value *(*indirect) (struct value *value);
 240
 241   /* If non-NULL, this is used to implement reference resolving for
 242      this value.  This method may return NULL, in which case coerce_ref
 243      will fall back to ordinary references resolving.  */
 244   struct value *(*coerce_ref) (const struct value *value);
 245
 246   /* If non-NULL, this is used to determine whether the indicated bits
 247      of VALUE are a synthetic pointer.  */
 248   int (*check_synthetic_pointer) (const struct value *value,
 249                                   int offset, int length);
 250
 251   /* Return a duplicate of VALUE's closure, for use in a new value.
 252      This may simply return the same closure, if VALUE's is
 253      reference-counted or statically allocated.
 254
 255      This may be NULL, in which case VALUE's closure is re-used in the
 256      new value.  */
 257   void *(*copy_closure) (const struct value *v);
 258
 259   /* Drop VALUE's reference to its closure.  Maybe this frees the
 260      closure; maybe this decrements a reference count; maybe the
 261      closure is statically allocated and this does nothing.
 262
 263      This may be NULL, in which case no action is taken to free
 264      VALUE's closure.  */
 265   void (*free_closure) (struct value *v);
 266 };
 267
 268 /* Create a computed lvalue, with type TYPE, function pointers FUNCS,
 269    and closure CLOSURE.  */
 270
 271 extern struct value *allocate_computed_value (struct type *type,
 272                                               const struct lval_funcs *funcs,
 273                                               void *closure);
 274
 275 /* Helper function to check the validity of some bits of a value.
 276
 277    If TYPE represents some aggregate type (e.g., a structure), return 1.
 278
 279    Otherwise, any of the bytes starting at OFFSET and extending for
 280    TYPE_LENGTH(TYPE) bytes are invalid, print a message to STREAM and
 281    return 0.  The checking is done using FUNCS.
 282
 283    Otherwise, return 1.  */
 284
 285 extern int valprint_check_validity (struct ui_file *stream, struct type *type,
 286                                     int embedded_offset,
 287                                     const struct value *val);
 288
 289 extern struct value *allocate_optimized_out_value (struct type *type);
 290
 291 /* If VALUE is lval_computed, return its lval_funcs structure.  */
 292
 293 extern const struct lval_funcs *value_computed_funcs (const struct value *);
 294
 295 /* If VALUE is lval_computed, return its closure.  The meaning of the
 296    returned value depends on the functions VALUE uses.  */
 297
 298 extern void *value_computed_closure (const struct value *value);
 299
 300 /* If zero, contents of this value are in the contents field.  If
 301    nonzero, contents are in inferior.  If the lval field is lval_memory,
 302    the contents are in inferior memory at location.address plus offset.
 303    The lval field may also be lval_register.
 304
 305    WARNING: This field is used by the code which handles watchpoints
 306    (see breakpoint.c) to decide whether a particular value can be
 307    watched by hardware watchpoints.  If the lazy flag is set for some
 308    member of a value chain, it is assumed that this member of the
 309    chain doesn't need to be watched as part of watching the value
 310    itself.  This is how GDB avoids watching the entire struct or array
 311    when the user wants to watch a single struct member or array
 312    element.  If you ever change the way lazy flag is set and reset, be
 313    sure to consider this use as well!  */
 314
 315 extern int value_lazy (const struct value *);
 316 extern void set_value_lazy (struct value *value, int val);
 317
 318 extern int value_stack (const struct value *);
 319 extern void set_value_stack (struct value *value, int val);
 320
 321 /* Throw an error complaining that the value has been optimized
 322    out.  */
 323
 324 extern void error_value_optimized_out (void);
 325
 326 /* value_contents() and value_contents_raw() both return the address
 327    of the gdb buffer used to hold a copy of the contents of the lval.
 328    value_contents() is used when the contents of the buffer are needed
 329    -- it uses value_fetch_lazy() to load the buffer from the process
 330    being debugged if it hasn't already been loaded
 331    (value_contents_writeable() is used when a writeable but fetched
 332    buffer is required)..  value_contents_raw() is used when data is
 333    being stored into the buffer, or when it is certain that the
 334    contents of the buffer are valid.
 335
 336    Note: The contents pointer is adjusted by the offset required to
 337    get to the real subobject, if the value happens to represent
 338    something embedded in a larger run-time object.  */
 339
 340 extern gdb_byte *value_contents_raw (struct value *);
 341
 342 /* Actual contents of the value.  For use of this value; setting it
 343    uses the stuff above.  Not valid if lazy is nonzero.  Target
 344    byte-order.  We force it to be aligned properly for any possible
 345    value.  Note that a value therefore extends beyond what is
 346    declared here.  */
 347
 348 extern const gdb_byte *value_contents (struct value *);
 349 extern gdb_byte *value_contents_writeable (struct value *);
 350
 351 /* The ALL variants of the above two macros do not adjust the returned
 352    pointer by the embedded_offset value.  */
 353
 354 extern gdb_byte *value_contents_all_raw (struct value *);
 355 extern const gdb_byte *value_contents_all (struct value *);
 356
 357 /* Like value_contents_all, but does not require that the returned
 358    bits be valid.  This should only be used in situations where you
 359    plan to check the validity manually.  */
 360 extern const gdb_byte *value_contents_for_printing (struct value *value);
 361
 362 /* Like value_contents_for_printing, but accepts a constant value
 363    pointer.  Unlike value_contents_for_printing however, the pointed
 364    value must _not_ be lazy.  */
 365 extern const gdb_byte *
 366   value_contents_for_printing_const (const struct value *value);
 367
 368 extern void value_fetch_lazy (struct value *val);
 369
 370 /* If nonzero, this is the value of a variable which does not actually
 371    exist in the program, at least partially.  If the value is lazy,
 372    this may fetch it now.  */
 373 extern int value_optimized_out (struct value *value);
 374
 375 /* Given a value, return true if any of the contents bits starting at
 376    OFFSET and extending for LENGTH bits is optimized out, false
 377    otherwise.  */
 378
 379 extern int value_bits_any_optimized_out (const struct value *value,
 380                                          int bit_offset, int bit_length);
 381
 382 /* Like value_optimized_out, but return true iff the whole value is
 383    optimized out.  */
 384 extern int value_entirely_optimized_out (struct value *value);
 385
 386 /* Mark VALUE's content bytes starting at OFFSET and extending for
 387    LENGTH bytes as optimized out.  */
 388
 389 extern void mark_value_bytes_optimized_out (struct value *value,
 390                                             int offset, int length);
 391
 392 /* Mark VALUE's content bits starting at OFFSET and extending for
 393    LENGTH bits as optimized out.  */
 394
 395 extern void mark_value_bits_optimized_out (struct value *value,
 396                                            int offset, int length);
 397
 398 /* Set or return field indicating whether a variable is initialized or
 399    not, based on debugging information supplied by the compiler.
 400    1 = initialized; 0 = uninitialized.  */
 401 extern int value_initialized (const struct value *);
 402 extern void set_value_initialized (struct value *, int);
 403
 404 /* Set COMPONENT's location as appropriate for a component of WHOLE
 405    --- regardless of what kind of lvalue WHOLE is.  */
 406 extern void set_value_component_location (struct value *component,
 407                                           const struct value *whole);
 408
 409 /* While the following fields are per- VALUE .CONTENT .PIECE (i.e., a
 410    single value might have multiple LVALs), this hacked interface is
 411    limited to just the first PIECE.  Expect further change.  */
 412 /* Type of value; either not an lval, or one of the various different
 413    possible kinds of lval.  */
 414 extern enum lval_type *deprecated_value_lval_hack (struct value *);
 415 #define VALUE_LVAL(val) (*deprecated_value_lval_hack (val))
 416
 417 /* Like VALUE_LVAL, except the parameter can be const.  */
 418 extern enum lval_type value_lval_const (const struct value *value);
 419
 420 /* If lval == lval_memory, return the address in the inferior.  If
 421    lval == lval_register, return the byte offset into the registers
 422    structure.  Otherwise, return 0.  The returned address
 423    includes the offset, if any.  */
 424 extern CORE_ADDR value_address (const struct value *);
 425
 426 /* Like value_address, except the result does not include value's
 427    offset.  */
 428 extern CORE_ADDR value_raw_address (const struct value *);
 429
 430 /* Set the address of a value.  */
 431 extern void set_value_address (struct value *, CORE_ADDR);
 432
 433 /* Pointer to internal variable.  */
 434 extern struct internalvar **deprecated_value_internalvar_hack (struct value *);
 435 #define VALUE_INTERNALVAR(val) (*deprecated_value_internalvar_hack (val))
 436
 437 /* Frame register value is relative to.  This will be described in the
 438    lval enum above as "lval_register".  */
 439 extern struct frame_id *deprecated_value_frame_id_hack (struct value *);
 440 #define VALUE_FRAME_ID(val) (*deprecated_value_frame_id_hack (val))
 441
 442 /* Register number if the value is from a register.  */
 443 extern short *deprecated_value_regnum_hack (struct value *);
 444 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
 445
 446 /* Return value after lval_funcs->coerce_ref (after check_typedef).  Return
 447    NULL if lval_funcs->coerce_ref is not applicable for whatever reason.  */
 448
 449 extern struct value *coerce_ref_if_computed (const struct value *arg);
 450
 451 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
 452    ENC_TYPE is the new enclosing type that should be set.  ORIGINAL_TYPE and
 453    ORIGINAL_VAL are the type and value of the original reference or pointer.
 454
 455    Note, that VALUE is modified by this function.
 456
 457    It is a common implementation for coerce_ref and value_ind.  */
 458
 459 extern struct value * readjust_indirect_value_type (struct value *value,
 460                                                     struct type *enc_type,
 461                                                     const struct type *original_type,
 462                                                     const struct value *original_val);
 463
 464 /* Convert a REF to the object referenced.  */
 465
 466 extern struct value *coerce_ref (struct value *value);
 467
 468 /* If ARG is an array, convert it to a pointer.
 469    If ARG is a function, convert it to a function pointer.
 470
 471    References are dereferenced.  */
 472
 473 extern struct value *coerce_array (struct value *value);
 474
 475 /* Given a value, determine whether the bits starting at OFFSET and
 476    extending for LENGTH bits are a synthetic pointer.  */
 477
 478 extern int value_bits_synthetic_pointer (const struct value *value,
 479                                          int offset, int length);
 480
 481 /* Given a value, determine whether the contents bytes starting at
 482    OFFSET and extending for LENGTH bytes are available.  This returns
 483    nonzero if all bytes in the given range are available, zero if any
 484    byte is unavailable.  */
 485
 486 extern int value_bytes_available (const struct value *value,
 487                                   int offset, int length);
 488
 489 /* Given a value, determine whether the contents bits starting at
 490    OFFSET and extending for LENGTH bits are available.  This returns
 491    nonzero if all bits in the given range are available, zero if any
 492    bit is unavailable.  */
 493
 494 extern int value_bits_available (const struct value *value,
 495                                  int offset, int length);
 496
 497 /* Like value_bytes_available, but return false if any byte in the
 498    whole object is unavailable.  */
 499 extern int value_entirely_available (struct value *value);
 500
 501 /* Like value_entirely_available, but return false if any byte in the
 502    whole object is available.  */
 503 extern int value_entirely_unavailable (struct value *value);
 504
 505 /* Mark VALUE's content bytes starting at OFFSET and extending for
 506    LENGTH bytes as unavailable.  */
 507
 508 extern void mark_value_bytes_unavailable (struct value *value,
 509                                           int offset, int length);
 510
 511 /* Mark VALUE's content bits starting at OFFSET and extending for
 512    LENGTH bits as unavailable.  */
 513
 514 extern void mark_value_bits_unavailable (struct value *value,
 515                                          int offset, int length);
 516
 517 /* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
 518    LENGTH bytes of VAL2's contents starting at OFFSET2.
 519
 520    Note that "contents" refers to the whole value's contents
 521    (value_contents_all), without any embedded offset adjustment.  For
 522    example, to compare a complete object value with itself, including
 523    its enclosing type chunk, you'd do:
 524
 525      int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
 526      value_contents_eq (val, 0, val, 0, len);
 527
 528    Returns true iff the set of available/valid contents match.
 529
 530    Optimized-out contents are equal to optimized-out contents, and are
 531    not equal to non-optimized-out contents.
 532
 533    Unavailable contente are equal to unavailable contents, and are not
 534    equal to non-unavailable contents.
 535
 536    For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
 537    represent different available/valid bytes, in a value with length
 538    16:
 539
 540      offset:   0   4   8   12  16
 541      contents: xxxxVVVVxxxxVVZZ
 542
 543    then:
 544
 545      value_contents_eq(val, 0, val, 8, 6) => 1
 546      value_contents_eq(val, 0, val, 4, 4) => 0
 547      value_contents_eq(val, 0, val, 8, 8) => 0
 548      value_contents_eq(val, 4, val, 12, 2) => 1
 549      value_contents_eq(val, 4, val, 12, 4) => 0
 550      value_contents_eq(val, 3, val, 4, 4) => 0
 551
 552    If 'x's represent an unavailable byte, 'o' represents an optimized
 553    out byte, in a value with length 8:
 554
 555      offset:   0   4   8
 556      contents: xxxxoooo
 557
 558    then:
 559
 560      value_contents_eq(val, 0, val, 2, 2) => 1
 561      value_contents_eq(val, 4, val, 6, 2) => 1
 562      value_contents_eq(val, 0, val, 4, 4) => 0
 563
 564    We only know whether a value chunk is unavailable or optimized out
 565    if we've tried to read it.  As this routine is used by printing
 566    routines, which may be printing values in the value history, long
 567    after the inferior is gone, it works with const values.  Therefore,
 568    this routine must not be called with lazy values.  */
 569
 570 extern int value_contents_eq (const struct value *val1, int offset1,
 571                               const struct value *val2, int offset2,
 572                               int length);
 573
 574 /* Read LENGTH addressable memory units starting at MEMADDR into BUFFER,
 575    which is (or will be copied to) VAL's contents buffer offset by
 576    EMBEDDED_OFFSET (that is, to &VAL->contents[EMBEDDED_OFFSET]).
 577    Marks value contents ranges as unavailable if the corresponding
 578    memory is likewise unavailable.  STACK indicates whether the memory
 579    is known to be stack memory.  */
 580
 581 extern void read_value_memory (struct value *val, int embedded_offset,
 582                                int stack, CORE_ADDR memaddr,
 583                                gdb_byte *buffer, size_t length);
 584
 585 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
 586    into each element of a new vector value with VECTOR_TYPE.  */
 587
 588 struct value *value_vector_widen (struct value *scalar_value,
 589                                   struct type *vector_type);
 590
 591 \f
 592
 593 #include "symtab.h"
 594 #include "gdbtypes.h"
 595 #include "expression.h"
 596
 597 struct frame_info;
 598 struct fn_field;
 599
 600 extern int print_address_demangle (const struct value_print_options *,
 601                                    struct gdbarch *, CORE_ADDR,
 602                                    struct ui_file *, int);
 603
 604 extern LONGEST value_as_long (struct value *val);
 605 extern DOUBLEST value_as_double (struct value *val);
 606 extern CORE_ADDR value_as_address (struct value *val);
 607
 608 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
 609 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
 610                                int *invp);
 611 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
 612
 613 extern LONGEST unpack_field_as_long (struct type *type,
 614                                      const gdb_byte *valaddr,
 615                                      int fieldno);
 616 extern int unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
 617                                 int embedded_offset, int fieldno,
 618                                 const struct value *val, LONGEST *result);
 619
 620 extern void unpack_value_bitfield (struct value *dest_val,
 621                                    int bitpos, int bitsize,
 622                                    const gdb_byte *valaddr, int embedded_offset,
 623                                    const struct value *val);
 624
 625 extern struct value *value_field_bitfield (struct type *type, int fieldno,
 626                                            const gdb_byte *valaddr,
 627                                            int embedded_offset,
 628                                            const struct value *val);
 629
 630 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
 631
 632 extern struct value *value_from_longest (struct type *type, LONGEST num);
 633 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
 634 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
 635 extern struct value *value_from_double (struct type *type, DOUBLEST num);
 636 extern struct value *value_from_decfloat (struct type *type,
 637                                           const gdb_byte *decbytes);
 638 extern struct value *value_from_history_ref (const char *, const char **);
 639
 640 extern struct value *value_at (struct type *type, CORE_ADDR addr);
 641 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
 642
 643 extern struct value *value_from_contents_and_address_unresolved
 644      (struct type *, const gdb_byte *, CORE_ADDR);
 645 extern struct value *value_from_contents_and_address (struct type *,
 646                                                       const gdb_byte *,
 647                                                       CORE_ADDR);
 648 extern struct value *value_from_contents (struct type *, const gdb_byte *);
 649
 650 extern struct value *default_value_from_register (struct gdbarch *gdbarch,
 651                                                   struct type *type,
 652                                                   int regnum,
 653                                                   struct frame_id frame_id);
 654
 655 extern void read_frame_register_value (struct value *value,
 656                                        struct frame_info *frame);
 657
 658 extern struct value *value_from_register (struct type *type, int regnum,
 659                                           struct frame_info *frame);
 660
 661 extern CORE_ADDR address_from_register (int regnum,
 662                                         struct frame_info *frame);
 663
 664 extern struct value *value_of_variable (struct symbol *var,
 665                                         const struct block *b);
 666
 667 extern struct value *address_of_variable (struct symbol *var,
 668                                           const struct block *b);
 669
 670 extern struct value *value_of_register (int regnum, struct frame_info *frame);
 671
 672 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
 673
 674 extern int symbol_read_needs_frame (struct symbol *);
 675
 676 extern struct value *read_var_value (struct symbol *var,
 677                                      const struct block *var_block,
 678                                      struct frame_info *frame);
 679
 680 extern struct value *default_read_var_value (struct symbol *var,
 681                                              const struct block *var_block,
 682                                              struct frame_info *frame);
 683
 684 extern struct value *allocate_value (struct type *type);
 685 extern struct value *allocate_value_lazy (struct type *type);
 686 extern void value_contents_copy (struct value *dst, int dst_offset,
 687                                  struct value *src, int src_offset,
 688                                  int length);
 689 extern void value_contents_copy_raw (struct value *dst, int dst_offset,
 690                                      struct value *src, int src_offset,
 691                                      int length);
 692
 693 extern struct value *allocate_repeat_value (struct type *type, int count);
 694
 695 extern struct value *value_mark (void);
 696
 697 extern void value_free_to_mark (const struct value *mark);
 698
 699 extern struct value *value_cstring (const char *ptr, ssize_t len,
 700                                     struct type *char_type);
 701 extern struct value *value_string (const char *ptr, ssize_t len,
 702                                    struct type *char_type);
 703
 704 extern struct value *value_array (int lowbound, int highbound,
 705                                   struct value **elemvec);
 706
 707 extern struct value *value_concat (struct value *arg1, struct value *arg2);
 708
 709 extern struct value *value_binop (struct value *arg1, struct value *arg2,
 710                                   enum exp_opcode op);
 711
 712 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
 713
 714 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
 715
 716 extern int value_must_coerce_to_target (struct value *arg1);
 717
 718 extern struct value *value_coerce_to_target (struct value *arg1);
 719
 720 extern struct value *value_coerce_array (struct value *arg1);
 721
 722 extern struct value *value_coerce_function (struct value *arg1);
 723
 724 extern struct value *value_ind (struct value *arg1);
 725
 726 extern struct value *value_addr (struct value *arg1);
 727
 728 extern struct value *value_ref (struct value *arg1);
 729
 730 extern struct value *value_assign (struct value *toval,
 731                                    struct value *fromval);
 732
 733 extern struct value *value_pos (struct value *arg1);
 734
 735 extern struct value *value_neg (struct value *arg1);
 736
 737 extern struct value *value_complement (struct value *arg1);
 738
 739 extern struct value *value_struct_elt (struct value **argp,
 740                                        struct value **args,
 741                                        const char *name, int *static_memfuncp,
 742                                        const char *err);
 743
 744 extern struct value *value_struct_elt_bitpos (struct value **argp,
 745                                               int bitpos,
 746                                               struct type *field_type,
 747                                               const char *err);
 748
 749 extern struct value *value_aggregate_elt (struct type *curtype,
 750                                           const char *name,
 751                                           struct type *expect_type,
 752                                           int want_address,
 753                                           enum noside noside);
 754
 755 extern struct value *value_static_field (struct type *type, int fieldno);
 756
 757 enum oload_search_type { NON_METHOD, METHOD, BOTH };
 758
 759 extern int find_overload_match (struct value **args, int nargs,
 760                                 const char *name,
 761                                 enum oload_search_type method,
 762                                 struct value **objp, struct symbol *fsym,
 763                                 struct value **valp, struct symbol **symp,
 764                                 int *staticp, const int no_adl,
 765                                 enum noside noside);
 766
 767 extern struct value *value_field (struct value *arg1, int fieldno);
 768
 769 extern struct value *value_primitive_field (struct value *arg1, int offset,
 770                                             int fieldno,
 771                                             struct type *arg_type);
 772
 773
 774 extern struct type *value_rtti_indirect_type (struct value *, int *, int *,
 775                                               int *);
 776
 777 extern struct value *value_full_object (struct value *, struct type *, int,
 778                                         int, int);
 779
 780 extern struct value *value_cast_pointers (struct type *, struct value *, int);
 781
 782 extern struct value *value_cast (struct type *type, struct value *arg2);
 783
 784 extern struct value *value_reinterpret_cast (struct type *type,
 785                                              struct value *arg);
 786
 787 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
 788
 789 extern struct value *value_zero (struct type *type, enum lval_type lv);
 790
 791 extern struct value *value_one (struct type *type);
 792
 793 extern struct value *value_repeat (struct value *arg1, int count);
 794
 795 extern struct value *value_subscript (struct value *array, LONGEST index);
 796
 797 extern struct value *value_bitstring_subscript (struct type *type,
 798                                                 struct value *bitstring,
 799                                                 LONGEST index);
 800
 801 extern struct value *register_value_being_returned (struct type *valtype,
 802                                                     struct regcache *retbuf);
 803
 804 extern int value_in (struct value *element, struct value *set);
 805
 806 extern int value_bit_index (struct type *type, const gdb_byte *addr,
 807                             int index);
 808
 809 extern enum return_value_convention
 810 struct_return_convention (struct gdbarch *gdbarch, struct value *function,
 811                           struct type *value_type);
 812
 813 extern int using_struct_return (struct gdbarch *gdbarch,
 814                                 struct value *function,
 815                                 struct type *value_type);
 816
 817 extern struct value *evaluate_expression (struct expression *exp);
 818
 819 extern struct value *evaluate_type (struct expression *exp);
 820
 821 extern struct value *evaluate_subexp (struct type *expect_type,
 822                                       struct expression *exp,
 823                                       int *pos, enum noside noside);
 824
 825 extern struct value *evaluate_subexpression_type (struct expression *exp,
 826                                                   int subexp);
 827
 828 extern void fetch_subexp_value (struct expression *exp, int *pc,
 829                                 struct value **valp, struct value **resultp,
 830                                 struct value **val_chain,
 831                                 int preserve_errors);
 832
 833 extern char *extract_field_op (struct expression *exp, int *subexp);
 834
 835 extern struct value *evaluate_subexp_with_coercion (struct expression *,
 836                                                     int *, enum noside);
 837
 838 extern struct value *parse_and_eval (const char *exp);
 839
 840 extern struct value *parse_to_comma_and_eval (const char **expp);
 841
 842 extern struct type *parse_and_eval_type (char *p, int length);
 843
 844 extern CORE_ADDR parse_and_eval_address (const char *exp);
 845
 846 extern LONGEST parse_and_eval_long (const char *exp);
 847
 848 extern void unop_promote (const struct language_defn *language,
 849                           struct gdbarch *gdbarch,
 850                           struct value **arg1);
 851
 852 extern void binop_promote (const struct language_defn *language,
 853                            struct gdbarch *gdbarch,
 854                            struct value **arg1, struct value **arg2);
 855
 856 extern struct value *access_value_history (int num);
 857
 858 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
 859                                            struct internalvar *var);
 860
 861 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
 862
 863 extern void set_internalvar (struct internalvar *var, struct value *val);
 864
 865 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
 866
 867 extern void set_internalvar_string (struct internalvar *var,
 868                                     const char *string);
 869
 870 extern void clear_internalvar (struct internalvar *var);
 871
 872 extern void set_internalvar_component (struct internalvar *var,
 873                                        int offset,
 874                                        int bitpos, int bitsize,
 875                                        struct value *newvalue);
 876
 877 extern struct internalvar *lookup_only_internalvar (const char *name);
 878
 879 extern struct internalvar *create_internalvar (const char *name);
 880
 881 extern VEC (char_ptr) *complete_internalvar (const char *name);
 882
 883 /* An internalvar can be dynamically computed by supplying a vector of
 884    function pointers to perform various operations.  */
 885
 886 struct internalvar_funcs
 887 {
 888   /* Compute the value of the variable.  The DATA argument passed to
 889      the function is the same argument that was passed to
 890      `create_internalvar_type_lazy'.  */
 891
 892   struct value *(*make_value) (struct gdbarch *arch,
 893                                struct internalvar *var,
 894                                void *data);
 895
 896   /* Update the agent expression EXPR with bytecode to compute the
 897      value.  VALUE is the agent value we are updating.  The DATA
 898      argument passed to this function is the same argument that was
 899      passed to `create_internalvar_type_lazy'.  If this pointer is
 900      NULL, then the internalvar cannot be compiled to an agent
 901      expression.  */
 902
 903   void (*compile_to_ax) (struct internalvar *var,
 904                          struct agent_expr *expr,
 905                          struct axs_value *value,
 906                          void *data);
 907
 908   /* If non-NULL, this is called to destroy DATA.  The DATA argument
 909      passed to this function is the same argument that was passed to
 910      `create_internalvar_type_lazy'.  */
 911
 912   void (*destroy) (void *data);
 913 };
 914
 915 extern struct internalvar *create_internalvar_type_lazy (const char *name,
 916                                 const struct internalvar_funcs *funcs,
 917                                 void *data);
 918
 919 /* Compile an internal variable to an agent expression.  VAR is the
 920    variable to compile; EXPR and VALUE are the agent expression we are
 921    updating.  This will return 0 if there is no known way to compile
 922    VAR, and 1 if VAR was successfully compiled.  It may also throw an
 923    exception on error.  */
 924
 925 extern int compile_internalvar_to_ax (struct internalvar *var,
 926                                       struct agent_expr *expr,
 927                                       struct axs_value *value);
 928
 929 extern struct internalvar *lookup_internalvar (const char *name);
 930
 931 extern int value_equal (struct value *arg1, struct value *arg2);
 932
 933 extern int value_equal_contents (struct value *arg1, struct value *arg2);
 934
 935 extern int value_less (struct value *arg1, struct value *arg2);
 936
 937 extern int value_logical_not (struct value *arg1);
 938
 939 /* C++ */
 940
 941 extern struct value *value_of_this (const struct language_defn *lang);
 942
 943 extern struct value *value_of_this_silent (const struct language_defn *lang);
 944
 945 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
 946                                     enum exp_opcode op,
 947                                     enum exp_opcode otherop,
 948                                     enum noside noside);
 949
 950 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
 951                                    enum noside noside);
 952
 953 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
 954                                      int j, struct type *type, int offset);
 955
 956 extern int binop_types_user_defined_p (enum exp_opcode op,
 957                                        struct type *type1,
 958                                        struct type *type2);
 959
 960 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
 961                                  struct value *arg2);
 962
 963 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
 964
 965 extern int destructor_name_p (const char *name, struct type *type);
 966
 967 extern void value_incref (struct value *val);
 968
 969 extern void value_free (struct value *val);
 970
 971 extern void free_all_values (void);
 972
 973 extern void free_value_chain (struct value *v);
 974
 975 extern void release_value (struct value *val);
 976
 977 extern void release_value_or_incref (struct value *val);
 978
 979 extern int record_latest_value (struct value *val);
 980
 981 extern void modify_field (struct type *type, gdb_byte *addr,
 982                           LONGEST fieldval, int bitpos, int bitsize);
 983
 984 extern void type_print (struct type *type, const char *varstring,
 985                         struct ui_file *stream, int show);
 986
 987 extern char *type_to_string (struct type *type);
 988
 989 extern gdb_byte *baseclass_addr (struct type *type, int index,
 990                                  gdb_byte *valaddr,
 991                                  struct value **valuep, int *errp);
 992
 993 extern void print_longest (struct ui_file *stream, int format,
 994                            int use_local, LONGEST val);
 995
 996 extern void print_floating (const gdb_byte *valaddr, struct type *type,
 997                             struct ui_file *stream);
 998
 999 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
1000                                     struct ui_file *stream);
1001
1002 extern void value_print (struct value *val, struct ui_file *stream,
1003                          const struct value_print_options *options);
1004
1005 extern void value_print_array_elements (struct value *val,
1006                                         struct ui_file *stream, int format,
1007                                         enum val_prettyformat pretty);
1008
1009 extern struct value *value_release_to_mark (const struct value *mark);
1010
1011 extern void val_print (struct type *type, const gdb_byte *valaddr,
1012                        int embedded_offset, CORE_ADDR address,
1013                        struct ui_file *stream, int recurse,
1014                        const struct value *val,
1015                        const struct value_print_options *options,
1016                        const struct language_defn *language);
1017
1018 extern void common_val_print (struct value *val,
1019                               struct ui_file *stream, int recurse,
1020                               const struct value_print_options *options,
1021                               const struct language_defn *language);
1022
1023 extern int val_print_string (struct type *elttype, const char *encoding,
1024                              CORE_ADDR addr, int len,
1025                              struct ui_file *stream,
1026                              const struct value_print_options *options);
1027
1028 extern void print_variable_and_value (const char *name,
1029                                       struct symbol *var,
1030                                       struct frame_info *frame,
1031                                       struct ui_file *stream,
1032                                       int indent);
1033
1034 extern void typedef_print (struct type *type, struct symbol *news,
1035                            struct ui_file *stream);
1036
1037 extern char *internalvar_name (const struct internalvar *var);
1038
1039 extern void preserve_values (struct objfile *);
1040
1041 /* From values.c */
1042
1043 extern struct value *value_copy (struct value *);
1044
1045 extern struct value *value_non_lval (struct value *);
1046
1047 extern void value_force_lval (struct value *, CORE_ADDR);
1048
1049 extern struct value *make_cv_value (int, int, struct value *);
1050
1051 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
1052
1053 /* From valops.c */
1054
1055 extern struct value *varying_to_slice (struct value *);
1056
1057 extern struct value *value_slice (struct value *, int, int);
1058
1059 extern struct value *value_literal_complex (struct value *, struct value *,
1060                                             struct type *);
1061
1062 extern struct value *find_function_in_inferior (const char *,
1063                                                 struct objfile **);
1064
1065 extern struct value *value_allocate_space_in_inferior (int);
1066
1067 extern struct value *value_subscripted_rvalue (struct value *array,
1068                                                LONGEST index, int lowerbound);
1069
1070 /* User function handler.  */
1071
1072 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
1073                                                const struct language_defn *language,
1074                                                void *cookie,
1075                                                int argc,
1076                                                struct value **argv);
1077
1078 void add_internal_function (const char *name, const char *doc,
1079                             internal_function_fn handler,
1080                             void *cookie);
1081
1082 struct value *call_internal_function (struct gdbarch *gdbarch,
1083                                       const struct language_defn *language,
1084                                       struct value *function,
1085                                       int argc, struct value **argv);
1086
1087 char *value_internal_function_name (struct value *);
1088
1089 extern struct value *value_of_xmethod (struct xmethod_worker *);
1090
1091 extern struct type *result_type_of_xmethod (struct value *method,
1092                                             int argc, struct value **argv);
1093
1094 extern struct value *call_xmethod (struct value *method,
1095                                    int argc, struct value **argv);
1096
1097 #endif /* !defined (VALUE_H) */