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1 /* Definitions for values of C expressions, for GDB.
2
3 Copyright (C) 1986-2017 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 LONGEST value_bitsize (const struct value *);
116 extern void set_value_bitsize (struct value *, LONGEST 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 LONGEST value_bitpos (const struct value *);
123 extern void set_value_bitpos (struct value *, LONGEST 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 LONGEST value_offset (const struct value *);
139 extern void set_value_offset (struct value *, LONGEST 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 LONGEST value_pointed_to_offset (const struct value *value);
209 extern void set_value_pointed_to_offset (struct value *value, LONGEST val);
210 extern LONGEST value_embedded_offset (const struct value *value);
211 extern void set_value_embedded_offset (struct value *value, LONGEST 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 LONGEST 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 LONGEST 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 LONGEST offset, LONGEST 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 ID of "next" frame to which a register value is relative. A
438 register value is indicated by VALUE_LVAL being set to lval_register.
439 So, if the register value is found relative to frame F, then the
440 frame id of F->next will be stored in VALUE_NEXT_FRAME_ID. */
441 extern struct frame_id *deprecated_value_next_frame_id_hack (struct value *);
442 #define VALUE_NEXT_FRAME_ID(val) (*deprecated_value_next_frame_id_hack (val))
443
444 /* Frame ID of frame to which a register value is relative. This is
445 similar to VALUE_NEXT_FRAME_ID, above, but may not be assigned to.
446 Note that VALUE_FRAME_ID effectively undoes the "next" operation
447 that was performed during the assignment to VALUE_NEXT_FRAME_ID. */
448 #define VALUE_FRAME_ID(val) (get_prev_frame_id_by_id (VALUE_NEXT_FRAME_ID (val)))
449
450 /* Register number if the value is from a register. */
451 extern int *deprecated_value_regnum_hack (struct value *);
452 #define VALUE_REGNUM(val) (*deprecated_value_regnum_hack (val))
453
454 /* Return value after lval_funcs->coerce_ref (after check_typedef). Return
455 NULL if lval_funcs->coerce_ref is not applicable for whatever reason. */
456
457 extern struct value *coerce_ref_if_computed (const struct value *arg);
458
459 /* Setup a new value type and enclosing value type for dereferenced value VALUE.
460 ENC_TYPE is the new enclosing type that should be set. ORIGINAL_TYPE and
461 ORIGINAL_VAL are the type and value of the original reference or pointer.
462
463 Note, that VALUE is modified by this function.
464
465 It is a common implementation for coerce_ref and value_ind. */
466
467 extern struct value * readjust_indirect_value_type (struct value *value,
468 struct type *enc_type,
469 const struct type *original_type,
470 const struct value *original_val);
471
472 /* Convert a REF to the object referenced. */
473
474 extern struct value *coerce_ref (struct value *value);
475
476 /* If ARG is an array, convert it to a pointer.
477 If ARG is a function, convert it to a function pointer.
478
479 References are dereferenced. */
480
481 extern struct value *coerce_array (struct value *value);
482
483 /* Given a value, determine whether the bits starting at OFFSET and
484 extending for LENGTH bits are a synthetic pointer. */
485
486 extern int value_bits_synthetic_pointer (const struct value *value,
487 LONGEST offset, LONGEST length);
488
489 /* Given a value, determine whether the contents bytes starting at
490 OFFSET and extending for LENGTH bytes are available. This returns
491 nonzero if all bytes in the given range are available, zero if any
492 byte is unavailable. */
493
494 extern int value_bytes_available (const struct value *value,
495 LONGEST offset, LONGEST length);
496
497 /* Given a value, determine whether the contents bits starting at
498 OFFSET and extending for LENGTH bits are available. This returns
499 nonzero if all bits in the given range are available, zero if any
500 bit is unavailable. */
501
502 extern int value_bits_available (const struct value *value,
503 LONGEST offset, LONGEST length);
504
505 /* Like value_bytes_available, but return false if any byte in the
506 whole object is unavailable. */
507 extern int value_entirely_available (struct value *value);
508
509 /* Like value_entirely_available, but return false if any byte in the
510 whole object is available. */
511 extern int value_entirely_unavailable (struct value *value);
512
513 /* Mark VALUE's content bytes starting at OFFSET and extending for
514 LENGTH bytes as unavailable. */
515
516 extern void mark_value_bytes_unavailable (struct value *value,
517 LONGEST offset, LONGEST length);
518
519 /* Mark VALUE's content bits starting at OFFSET and extending for
520 LENGTH bits as unavailable. */
521
522 extern void mark_value_bits_unavailable (struct value *value,
523 LONGEST offset, LONGEST length);
524
525 /* Compare LENGTH bytes of VAL1's contents starting at OFFSET1 with
526 LENGTH bytes of VAL2's contents starting at OFFSET2.
527
528 Note that "contents" refers to the whole value's contents
529 (value_contents_all), without any embedded offset adjustment. For
530 example, to compare a complete object value with itself, including
531 its enclosing type chunk, you'd do:
532
533 int len = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
534 value_contents_eq (val, 0, val, 0, len);
535
536 Returns true iff the set of available/valid contents match.
537
538 Optimized-out contents are equal to optimized-out contents, and are
539 not equal to non-optimized-out contents.
540
541 Unavailable contente are equal to unavailable contents, and are not
542 equal to non-unavailable contents.
543
544 For example, if 'x's represent an unavailable byte, and 'V' and 'Z'
545 represent different available/valid bytes, in a value with length
546 16:
547
548 offset: 0 4 8 12 16
549 contents: xxxxVVVVxxxxVVZZ
550
551 then:
552
553 value_contents_eq(val, 0, val, 8, 6) => 1
554 value_contents_eq(val, 0, val, 4, 4) => 0
555 value_contents_eq(val, 0, val, 8, 8) => 0
556 value_contents_eq(val, 4, val, 12, 2) => 1
557 value_contents_eq(val, 4, val, 12, 4) => 0
558 value_contents_eq(val, 3, val, 4, 4) => 0
559
560 If 'x's represent an unavailable byte, 'o' represents an optimized
561 out byte, in a value with length 8:
562
563 offset: 0 4 8
564 contents: xxxxoooo
565
566 then:
567
568 value_contents_eq(val, 0, val, 2, 2) => 1
569 value_contents_eq(val, 4, val, 6, 2) => 1
570 value_contents_eq(val, 0, val, 4, 4) => 0
571
572 We only know whether a value chunk is unavailable or optimized out
573 if we've tried to read it. As this routine is used by printing
574 routines, which may be printing values in the value history, long
575 after the inferior is gone, it works with const values. Therefore,
576 this routine must not be called with lazy values. */
577
578 extern int value_contents_eq (const struct value *val1, LONGEST offset1,
579 const struct value *val2, LONGEST offset2,
580 LONGEST length);
581
582 /* Read LENGTH addressable memory units starting at MEMADDR into BUFFER,
583 which is (or will be copied to) VAL's contents buffer offset by
584 BIT_OFFSET bits. Marks value contents ranges as unavailable if
585 the corresponding memory is likewise unavailable. STACK indicates
586 whether the memory is known to be stack memory. */
587
588 extern void read_value_memory (struct value *val, LONGEST bit_offset,
589 int stack, CORE_ADDR memaddr,
590 gdb_byte *buffer, size_t length);
591
592 /* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate
593 into each element of a new vector value with VECTOR_TYPE. */
594
595 struct value *value_vector_widen (struct value *scalar_value,
596 struct type *vector_type);
597
598 \f
599
600 #include "symtab.h"
601 #include "gdbtypes.h"
602 #include "expression.h"
603
604 struct frame_info;
605 struct fn_field;
606
607 extern int print_address_demangle (const struct value_print_options *,
608 struct gdbarch *, CORE_ADDR,
609 struct ui_file *, int);
610
611 extern LONGEST value_as_long (struct value *val);
612 extern DOUBLEST value_as_double (struct value *val);
613 extern CORE_ADDR value_as_address (struct value *val);
614
615 extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr);
616 extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr,
617 int *invp);
618 extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr);
619
620 extern LONGEST unpack_field_as_long (struct type *type,
621 const gdb_byte *valaddr,
622 int fieldno);
623 extern int unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr,
624 LONGEST embedded_offset, int fieldno,
625 const struct value *val, LONGEST *result);
626
627 extern void unpack_value_bitfield (struct value *dest_val,
628 LONGEST bitpos, LONGEST bitsize,
629 const gdb_byte *valaddr,
630 LONGEST embedded_offset,
631 const struct value *val);
632
633 extern struct value *value_field_bitfield (struct type *type, int fieldno,
634 const gdb_byte *valaddr,
635 LONGEST embedded_offset,
636 const struct value *val);
637
638 extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num);
639
640 extern struct value *value_from_longest (struct type *type, LONGEST num);
641 extern struct value *value_from_ulongest (struct type *type, ULONGEST num);
642 extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr);
643 extern struct value *value_from_double (struct type *type, DOUBLEST num);
644 extern struct value *value_from_decfloat (struct type *type,
645 const gdb_byte *decbytes);
646 extern struct value *value_from_history_ref (const char *, const char **);
647 extern struct value *value_from_component (struct value *, struct type *,
648 LONGEST);
649
650 extern struct value *value_at (struct type *type, CORE_ADDR addr);
651 extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr);
652
653 extern struct value *value_from_contents_and_address_unresolved
654 (struct type *, const gdb_byte *, CORE_ADDR);
655 extern struct value *value_from_contents_and_address (struct type *,
656 const gdb_byte *,
657 CORE_ADDR);
658 extern struct value *value_from_contents (struct type *, const gdb_byte *);
659
660 extern struct value *default_value_from_register (struct gdbarch *gdbarch,
661 struct type *type,
662 int regnum,
663 struct frame_id frame_id);
664
665 extern void read_frame_register_value (struct value *value,
666 struct frame_info *frame);
667
668 extern struct value *value_from_register (struct type *type, int regnum,
669 struct frame_info *frame);
670
671 extern CORE_ADDR address_from_register (int regnum,
672 struct frame_info *frame);
673
674 extern struct value *value_of_variable (struct symbol *var,
675 const struct block *b);
676
677 extern struct value *address_of_variable (struct symbol *var,
678 const struct block *b);
679
680 extern struct value *value_of_register (int regnum, struct frame_info *frame);
681
682 struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
683
684 /* Return the symbol's reading requirement. */
685
686 extern enum symbol_needs_kind symbol_read_needs (struct symbol *);
687
688 /* Return true if the symbol needs a frame. This is a wrapper for
689 symbol_read_needs that simply checks for SYMBOL_NEEDS_FRAME. */
690
691 extern int symbol_read_needs_frame (struct symbol *);
692
693 extern struct value *read_var_value (struct symbol *var,
694 const struct block *var_block,
695 struct frame_info *frame);
696
697 extern struct value *default_read_var_value (struct symbol *var,
698 const struct block *var_block,
699 struct frame_info *frame);
700
701 extern struct value *allocate_value (struct type *type);
702 extern struct value *allocate_value_lazy (struct type *type);
703 extern void value_contents_copy (struct value *dst, LONGEST dst_offset,
704 struct value *src, LONGEST src_offset,
705 LONGEST length);
706 extern void value_contents_copy_raw (struct value *dst, LONGEST dst_offset,
707 struct value *src, LONGEST src_offset,
708 LONGEST length);
709
710 extern struct value *allocate_repeat_value (struct type *type, int count);
711
712 extern struct value *value_mark (void);
713
714 extern void value_free_to_mark (const struct value *mark);
715
716 /* A helper class that uses value_mark at construction time and calls
717 value_free_to_mark in the destructor. This is used to clear out
718 temporary values created during the lifetime of this object. */
719 class scoped_value_mark
720 {
721 public:
722
723 scoped_value_mark ()
724 : m_value (value_mark ())
725 {
726 }
727
728 ~scoped_value_mark ()
729 {
730 free_to_mark ();
731 }
732
733 scoped_value_mark (scoped_value_mark &&other) = default;
734
735 DISABLE_COPY_AND_ASSIGN (scoped_value_mark);
736
737 /* Free the values currently on the value stack. */
738 void free_to_mark ()
739 {
740 if (m_value != NULL)
741 {
742 value_free_to_mark (m_value);
743 m_value = NULL;
744 }
745 }
746
747 private:
748
749 const struct value *m_value;
750 };
751
752 extern struct value *value_cstring (const char *ptr, ssize_t len,
753 struct type *char_type);
754 extern struct value *value_string (const char *ptr, ssize_t len,
755 struct type *char_type);
756
757 extern struct value *value_array (int lowbound, int highbound,
758 struct value **elemvec);
759
760 extern struct value *value_concat (struct value *arg1, struct value *arg2);
761
762 extern struct value *value_binop (struct value *arg1, struct value *arg2,
763 enum exp_opcode op);
764
765 extern struct value *value_ptradd (struct value *arg1, LONGEST arg2);
766
767 extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2);
768
769 extern int value_must_coerce_to_target (struct value *arg1);
770
771 extern struct value *value_coerce_to_target (struct value *arg1);
772
773 extern struct value *value_coerce_array (struct value *arg1);
774
775 extern struct value *value_coerce_function (struct value *arg1);
776
777 extern struct value *value_ind (struct value *arg1);
778
779 extern struct value *value_addr (struct value *arg1);
780
781 extern struct value *value_ref (struct value *arg1, enum type_code refcode);
782
783 extern struct value *value_assign (struct value *toval,
784 struct value *fromval);
785
786 extern struct value *value_pos (struct value *arg1);
787
788 extern struct value *value_neg (struct value *arg1);
789
790 extern struct value *value_complement (struct value *arg1);
791
792 extern struct value *value_struct_elt (struct value **argp,
793 struct value **args,
794 const char *name, int *static_memfuncp,
795 const char *err);
796
797 extern struct value *value_struct_elt_bitpos (struct value **argp,
798 int bitpos,
799 struct type *field_type,
800 const char *err);
801
802 extern struct value *value_aggregate_elt (struct type *curtype,
803 const char *name,
804 struct type *expect_type,
805 int want_address,
806 enum noside noside);
807
808 extern struct value *value_static_field (struct type *type, int fieldno);
809
810 enum oload_search_type { NON_METHOD, METHOD, BOTH };
811
812 extern int find_overload_match (struct value **args, int nargs,
813 const char *name,
814 enum oload_search_type method,
815 struct value **objp, struct symbol *fsym,
816 struct value **valp, struct symbol **symp,
817 int *staticp, const int no_adl,
818 enum noside noside);
819
820 extern struct value *value_field (struct value *arg1, int fieldno);
821
822 extern struct value *value_primitive_field (struct value *arg1, LONGEST offset,
823 int fieldno,
824 struct type *arg_type);
825
826
827 extern struct type *value_rtti_indirect_type (struct value *, int *, LONGEST *,
828 int *);
829
830 extern struct value *value_full_object (struct value *, struct type *, int,
831 int, int);
832
833 extern struct value *value_cast_pointers (struct type *, struct value *, int);
834
835 extern struct value *value_cast (struct type *type, struct value *arg2);
836
837 extern struct value *value_reinterpret_cast (struct type *type,
838 struct value *arg);
839
840 extern struct value *value_dynamic_cast (struct type *type, struct value *arg);
841
842 extern struct value *value_zero (struct type *type, enum lval_type lv);
843
844 extern struct value *value_one (struct type *type);
845
846 extern struct value *value_repeat (struct value *arg1, int count);
847
848 extern struct value *value_subscript (struct value *array, LONGEST index);
849
850 extern struct value *value_bitstring_subscript (struct type *type,
851 struct value *bitstring,
852 LONGEST index);
853
854 extern struct value *register_value_being_returned (struct type *valtype,
855 struct regcache *retbuf);
856
857 extern int value_in (struct value *element, struct value *set);
858
859 extern int value_bit_index (struct type *type, const gdb_byte *addr,
860 int index);
861
862 extern enum return_value_convention
863 struct_return_convention (struct gdbarch *gdbarch, struct value *function,
864 struct type *value_type);
865
866 extern int using_struct_return (struct gdbarch *gdbarch,
867 struct value *function,
868 struct type *value_type);
869
870 extern struct value *evaluate_expression (struct expression *exp);
871
872 extern struct value *evaluate_type (struct expression *exp);
873
874 extern struct value *evaluate_subexp (struct type *expect_type,
875 struct expression *exp,
876 int *pos, enum noside noside);
877
878 extern struct value *evaluate_subexpression_type (struct expression *exp,
879 int subexp);
880
881 extern void fetch_subexp_value (struct expression *exp, int *pc,
882 struct value **valp, struct value **resultp,
883 struct value **val_chain,
884 int preserve_errors);
885
886 extern char *extract_field_op (struct expression *exp, int *subexp);
887
888 extern struct value *evaluate_subexp_with_coercion (struct expression *,
889 int *, enum noside);
890
891 extern struct value *parse_and_eval (const char *exp);
892
893 extern struct value *parse_to_comma_and_eval (const char **expp);
894
895 extern struct type *parse_and_eval_type (char *p, int length);
896
897 extern CORE_ADDR parse_and_eval_address (const char *exp);
898
899 extern LONGEST parse_and_eval_long (const char *exp);
900
901 extern void unop_promote (const struct language_defn *language,
902 struct gdbarch *gdbarch,
903 struct value **arg1);
904
905 extern void binop_promote (const struct language_defn *language,
906 struct gdbarch *gdbarch,
907 struct value **arg1, struct value **arg2);
908
909 extern struct value *access_value_history (int num);
910
911 extern struct value *value_of_internalvar (struct gdbarch *gdbarch,
912 struct internalvar *var);
913
914 extern int get_internalvar_integer (struct internalvar *var, LONGEST *l);
915
916 extern void set_internalvar (struct internalvar *var, struct value *val);
917
918 extern void set_internalvar_integer (struct internalvar *var, LONGEST l);
919
920 extern void set_internalvar_string (struct internalvar *var,
921 const char *string);
922
923 extern void clear_internalvar (struct internalvar *var);
924
925 extern void set_internalvar_component (struct internalvar *var,
926 LONGEST offset,
927 LONGEST bitpos, LONGEST bitsize,
928 struct value *newvalue);
929
930 extern struct internalvar *lookup_only_internalvar (const char *name);
931
932 extern struct internalvar *create_internalvar (const char *name);
933
934 extern void complete_internalvar (completion_tracker &tracker,
935 const char *name);
936
937 /* An internalvar can be dynamically computed by supplying a vector of
938 function pointers to perform various operations. */
939
940 struct internalvar_funcs
941 {
942 /* Compute the value of the variable. The DATA argument passed to
943 the function is the same argument that was passed to
944 `create_internalvar_type_lazy'. */
945
946 struct value *(*make_value) (struct gdbarch *arch,
947 struct internalvar *var,
948 void *data);
949
950 /* Update the agent expression EXPR with bytecode to compute the
951 value. VALUE is the agent value we are updating. The DATA
952 argument passed to this function is the same argument that was
953 passed to `create_internalvar_type_lazy'. If this pointer is
954 NULL, then the internalvar cannot be compiled to an agent
955 expression. */
956
957 void (*compile_to_ax) (struct internalvar *var,
958 struct agent_expr *expr,
959 struct axs_value *value,
960 void *data);
961
962 /* If non-NULL, this is called to destroy DATA. The DATA argument
963 passed to this function is the same argument that was passed to
964 `create_internalvar_type_lazy'. */
965
966 void (*destroy) (void *data);
967 };
968
969 extern struct internalvar *create_internalvar_type_lazy (const char *name,
970 const struct internalvar_funcs *funcs,
971 void *data);
972
973 /* Compile an internal variable to an agent expression. VAR is the
974 variable to compile; EXPR and VALUE are the agent expression we are
975 updating. This will return 0 if there is no known way to compile
976 VAR, and 1 if VAR was successfully compiled. It may also throw an
977 exception on error. */
978
979 extern int compile_internalvar_to_ax (struct internalvar *var,
980 struct agent_expr *expr,
981 struct axs_value *value);
982
983 extern struct internalvar *lookup_internalvar (const char *name);
984
985 extern int value_equal (struct value *arg1, struct value *arg2);
986
987 extern int value_equal_contents (struct value *arg1, struct value *arg2);
988
989 extern int value_less (struct value *arg1, struct value *arg2);
990
991 extern int value_logical_not (struct value *arg1);
992
993 /* C++ */
994
995 extern struct value *value_of_this (const struct language_defn *lang);
996
997 extern struct value *value_of_this_silent (const struct language_defn *lang);
998
999 extern struct value *value_x_binop (struct value *arg1, struct value *arg2,
1000 enum exp_opcode op,
1001 enum exp_opcode otherop,
1002 enum noside noside);
1003
1004 extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op,
1005 enum noside noside);
1006
1007 extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f,
1008 int j, struct type *type, LONGEST offset);
1009
1010 extern int binop_types_user_defined_p (enum exp_opcode op,
1011 struct type *type1,
1012 struct type *type2);
1013
1014 extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1,
1015 struct value *arg2);
1016
1017 extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1);
1018
1019 extern int destructor_name_p (const char *name, struct type *type);
1020
1021 extern void value_incref (struct value *val);
1022
1023 extern void value_free (struct value *val);
1024
1025 /* A free policy class to interface std::unique_ptr with
1026 value_free. */
1027
1028 struct value_deleter
1029 {
1030 void operator() (struct value *value) const
1031 {
1032 value_free (value);
1033 }
1034 };
1035
1036 /* A unique pointer to a struct value. */
1037
1038 typedef std::unique_ptr<struct value, value_deleter> gdb_value_up;
1039
1040 extern void free_all_values (void);
1041
1042 extern void free_value_chain (struct value *v);
1043
1044 extern void release_value (struct value *val);
1045
1046 extern void release_value_or_incref (struct value *val);
1047
1048 extern int record_latest_value (struct value *val);
1049
1050 extern void modify_field (struct type *type, gdb_byte *addr,
1051 LONGEST fieldval, LONGEST bitpos, LONGEST bitsize);
1052
1053 extern void type_print (struct type *type, const char *varstring,
1054 struct ui_file *stream, int show);
1055
1056 extern std::string type_to_string (struct type *type);
1057
1058 extern gdb_byte *baseclass_addr (struct type *type, int index,
1059 gdb_byte *valaddr,
1060 struct value **valuep, int *errp);
1061
1062 extern void print_longest (struct ui_file *stream, int format,
1063 int use_local, LONGEST val);
1064
1065 extern void print_floating (const gdb_byte *valaddr, struct type *type,
1066 struct ui_file *stream);
1067
1068 extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type,
1069 struct ui_file *stream);
1070
1071 extern void value_print (struct value *val, struct ui_file *stream,
1072 const struct value_print_options *options);
1073
1074 extern void value_print_array_elements (struct value *val,
1075 struct ui_file *stream, int format,
1076 enum val_prettyformat pretty);
1077
1078 extern struct value *value_release_to_mark (const struct value *mark);
1079
1080 extern void val_print (struct type *type,
1081 LONGEST embedded_offset, CORE_ADDR address,
1082 struct ui_file *stream, int recurse,
1083 struct value *val,
1084 const struct value_print_options *options,
1085 const struct language_defn *language);
1086
1087 extern void common_val_print (struct value *val,
1088 struct ui_file *stream, int recurse,
1089 const struct value_print_options *options,
1090 const struct language_defn *language);
1091
1092 extern int val_print_string (struct type *elttype, const char *encoding,
1093 CORE_ADDR addr, int len,
1094 struct ui_file *stream,
1095 const struct value_print_options *options);
1096
1097 extern void print_variable_and_value (const char *name,
1098 struct symbol *var,
1099 struct frame_info *frame,
1100 struct ui_file *stream,
1101 int indent);
1102
1103 extern void typedef_print (struct type *type, struct symbol *news,
1104 struct ui_file *stream);
1105
1106 extern char *internalvar_name (const struct internalvar *var);
1107
1108 extern void preserve_values (struct objfile *);
1109
1110 /* From values.c */
1111
1112 extern struct value *value_copy (struct value *);
1113
1114 extern struct value *value_non_lval (struct value *);
1115
1116 extern void value_force_lval (struct value *, CORE_ADDR);
1117
1118 extern struct value *make_cv_value (int, int, struct value *);
1119
1120 extern void preserve_one_value (struct value *, struct objfile *, htab_t);
1121
1122 /* From valops.c */
1123
1124 extern struct value *varying_to_slice (struct value *);
1125
1126 extern struct value *value_slice (struct value *, int, int);
1127
1128 extern struct value *value_literal_complex (struct value *, struct value *,
1129 struct type *);
1130
1131 extern struct value *find_function_in_inferior (const char *,
1132 struct objfile **);
1133
1134 extern struct value *value_allocate_space_in_inferior (int);
1135
1136 extern struct value *value_subscripted_rvalue (struct value *array,
1137 LONGEST index, int lowerbound);
1138
1139 /* User function handler. */
1140
1141 typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch,
1142 const struct language_defn *language,
1143 void *cookie,
1144 int argc,
1145 struct value **argv);
1146
1147 void add_internal_function (const char *name, const char *doc,
1148 internal_function_fn handler,
1149 void *cookie);
1150
1151 struct value *call_internal_function (struct gdbarch *gdbarch,
1152 const struct language_defn *language,
1153 struct value *function,
1154 int argc, struct value **argv);
1155
1156 char *value_internal_function_name (struct value *);
1157
1158 extern struct value *value_of_xmethod (struct xmethod_worker *);
1159
1160 extern struct type *result_type_of_xmethod (struct value *method,
1161 int argc, struct value **argv);
1162
1163 extern struct value *call_xmethod (struct value *method,
1164 int argc, struct value **argv);
1165
1166 #endif /* !defined (VALUE_H) */