xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/value.h (revision 7c192b2a5e1093666e67801684f930ef49b3b363)
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 void 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 
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) */
1092