value.h revision 1.7
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 26struct block; 27struct expression; 28struct regcache; 29struct symbol; 30struct type; 31struct ui_file; 32struct language_defn; 33struct value_print_options; 34struct 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 89struct 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 96struct value *value_next (const struct value *); 97 98/* Type of the value. */ 99 100extern struct type *value_type (const struct value *); 101 102/* Return the gdbarch associated with the value. */ 103 104extern 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 110extern 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 115extern LONGEST value_bitsize (const struct value *); 116extern 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 122extern LONGEST value_bitpos (const struct value *); 123extern 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 129struct value *value_parent (const struct value *); 130extern 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 138extern LONGEST value_offset (const struct value *); 139extern 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 145extern 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 188extern struct type *value_enclosing_type (const struct value *); 189extern 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 204extern struct type *value_actual_type (struct value *value, 205 int resolve_simple_types, 206 int *real_type_found); 207 208extern LONGEST value_pointed_to_offset (const struct value *value); 209extern void set_value_pointed_to_offset (struct value *value, LONGEST val); 210extern LONGEST value_embedded_offset (const struct value *value); 211extern 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 221struct 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 271extern 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 285extern int valprint_check_validity (struct ui_file *stream, struct type *type, 286 LONGEST embedded_offset, 287 const struct value *val); 288 289extern struct value *allocate_optimized_out_value (struct type *type); 290 291/* If VALUE is lval_computed, return its lval_funcs structure. */ 292 293extern 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 298extern 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 315extern int value_lazy (const struct value *); 316extern void set_value_lazy (struct value *value, int val); 317 318extern int value_stack (const struct value *); 319extern void set_value_stack (struct value *value, int val); 320 321/* Throw an error complaining that the value has been optimized 322 out. */ 323 324extern 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 340extern 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 348extern const gdb_byte *value_contents (struct value *); 349extern 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 354extern gdb_byte *value_contents_all_raw (struct value *); 355extern 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. */ 360extern 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. */ 365extern const gdb_byte * 366 value_contents_for_printing_const (const struct value *value); 367 368extern 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. */ 373extern 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 379extern 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. */ 384extern 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 389extern 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 395extern 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. */ 401extern int value_initialized (const struct value *); 402extern 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. */ 406extern 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. */ 414extern 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. */ 418extern 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. */ 424extern CORE_ADDR value_address (const struct value *); 425 426/* Like value_address, except the result does not include value's 427 offset. */ 428extern CORE_ADDR value_raw_address (const struct value *); 429 430/* Set the address of a value. */ 431extern void set_value_address (struct value *, CORE_ADDR); 432 433/* Pointer to internal variable. */ 434extern 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. */ 441extern 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. */ 451extern 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 457extern 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 467extern 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 474extern 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 481extern 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 486extern 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 494extern 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 502extern 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. */ 507extern 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. */ 511extern 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 516extern 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 522extern 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 578extern 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 EMBEDDED_OFFSET (that is, to &VAL->contents[EMBEDDED_OFFSET]). 585 Marks value contents ranges as unavailable if the corresponding 586 memory is likewise unavailable. STACK indicates whether the memory 587 is known to be stack memory. */ 588 589extern void read_value_memory (struct value *val, LONGEST embedded_offset, 590 int stack, CORE_ADDR memaddr, 591 gdb_byte *buffer, size_t length); 592 593/* Cast SCALAR_VALUE to the element type of VECTOR_TYPE, then replicate 594 into each element of a new vector value with VECTOR_TYPE. */ 595 596struct value *value_vector_widen (struct value *scalar_value, 597 struct type *vector_type); 598 599 600 601#include "symtab.h" 602#include "gdbtypes.h" 603#include "expression.h" 604 605struct frame_info; 606struct fn_field; 607 608extern int print_address_demangle (const struct value_print_options *, 609 struct gdbarch *, CORE_ADDR, 610 struct ui_file *, int); 611 612extern LONGEST value_as_long (struct value *val); 613extern DOUBLEST value_as_double (struct value *val); 614extern CORE_ADDR value_as_address (struct value *val); 615 616extern LONGEST unpack_long (struct type *type, const gdb_byte *valaddr); 617extern DOUBLEST unpack_double (struct type *type, const gdb_byte *valaddr, 618 int *invp); 619extern CORE_ADDR unpack_pointer (struct type *type, const gdb_byte *valaddr); 620 621extern LONGEST unpack_field_as_long (struct type *type, 622 const gdb_byte *valaddr, 623 int fieldno); 624extern int unpack_value_field_as_long (struct type *type, const gdb_byte *valaddr, 625 LONGEST embedded_offset, int fieldno, 626 const struct value *val, LONGEST *result); 627 628extern void unpack_value_bitfield (struct value *dest_val, 629 LONGEST bitpos, LONGEST bitsize, 630 const gdb_byte *valaddr, 631 LONGEST embedded_offset, 632 const struct value *val); 633 634extern struct value *value_field_bitfield (struct type *type, int fieldno, 635 const gdb_byte *valaddr, 636 LONGEST embedded_offset, 637 const struct value *val); 638 639extern void pack_long (gdb_byte *buf, struct type *type, LONGEST num); 640 641extern struct value *value_from_longest (struct type *type, LONGEST num); 642extern struct value *value_from_ulongest (struct type *type, ULONGEST num); 643extern struct value *value_from_pointer (struct type *type, CORE_ADDR addr); 644extern struct value *value_from_double (struct type *type, DOUBLEST num); 645extern struct value *value_from_decfloat (struct type *type, 646 const gdb_byte *decbytes); 647extern struct value *value_from_history_ref (const char *, const char **); 648extern struct value *value_from_component (struct value *, struct type *, 649 LONGEST); 650 651extern struct value *value_at (struct type *type, CORE_ADDR addr); 652extern struct value *value_at_lazy (struct type *type, CORE_ADDR addr); 653 654extern struct value *value_from_contents_and_address_unresolved 655 (struct type *, const gdb_byte *, CORE_ADDR); 656extern struct value *value_from_contents_and_address (struct type *, 657 const gdb_byte *, 658 CORE_ADDR); 659extern struct value *value_from_contents (struct type *, const gdb_byte *); 660 661extern struct value *default_value_from_register (struct gdbarch *gdbarch, 662 struct type *type, 663 int regnum, 664 struct frame_id frame_id); 665 666extern void read_frame_register_value (struct value *value, 667 struct frame_info *frame); 668 669extern struct value *value_from_register (struct type *type, int regnum, 670 struct frame_info *frame); 671 672extern CORE_ADDR address_from_register (int regnum, 673 struct frame_info *frame); 674 675extern struct value *value_of_variable (struct symbol *var, 676 const struct block *b); 677 678extern struct value *address_of_variable (struct symbol *var, 679 const struct block *b); 680 681extern struct value *value_of_register (int regnum, struct frame_info *frame); 682 683struct value *value_of_register_lazy (struct frame_info *frame, int regnum); 684 685/* Return the symbol's reading requirement. */ 686 687extern enum symbol_needs_kind symbol_read_needs (struct symbol *); 688 689/* Return true if the symbol needs a frame. This is a wrapper for 690 symbol_read_needs that simply checks for SYMBOL_NEEDS_FRAME. */ 691 692extern int symbol_read_needs_frame (struct symbol *); 693 694extern struct value *read_var_value (struct symbol *var, 695 const struct block *var_block, 696 struct frame_info *frame); 697 698extern struct value *default_read_var_value (struct symbol *var, 699 const struct block *var_block, 700 struct frame_info *frame); 701 702extern struct value *allocate_value (struct type *type); 703extern struct value *allocate_value_lazy (struct type *type); 704extern void value_contents_copy (struct value *dst, LONGEST dst_offset, 705 struct value *src, LONGEST src_offset, 706 LONGEST length); 707extern void value_contents_copy_raw (struct value *dst, LONGEST dst_offset, 708 struct value *src, LONGEST src_offset, 709 LONGEST length); 710 711extern struct value *allocate_repeat_value (struct type *type, int count); 712 713extern struct value *value_mark (void); 714 715extern void value_free_to_mark (const struct value *mark); 716 717/* A helper class that uses value_mark at construction time and calls 718 value_free_to_mark in the destructor. This is used to clear out 719 temporary values created during the lifetime of this object. */ 720class scoped_value_mark 721{ 722 public: 723 724 scoped_value_mark () 725 : m_value (value_mark ()) 726 { 727 } 728 729 ~scoped_value_mark () 730 { 731 free_to_mark (); 732 } 733 734 /* Free the values currently on the value stack. */ 735 void free_to_mark () 736 { 737 if (m_value != NULL) 738 { 739 value_free_to_mark (m_value); 740 m_value = NULL; 741 } 742 } 743 744 private: 745 746 const struct value *m_value; 747}; 748 749extern struct value *value_cstring (const char *ptr, ssize_t len, 750 struct type *char_type); 751extern struct value *value_string (const char *ptr, ssize_t len, 752 struct type *char_type); 753 754extern struct value *value_array (int lowbound, int highbound, 755 struct value **elemvec); 756 757extern struct value *value_concat (struct value *arg1, struct value *arg2); 758 759extern struct value *value_binop (struct value *arg1, struct value *arg2, 760 enum exp_opcode op); 761 762extern struct value *value_ptradd (struct value *arg1, LONGEST arg2); 763 764extern LONGEST value_ptrdiff (struct value *arg1, struct value *arg2); 765 766extern int value_must_coerce_to_target (struct value *arg1); 767 768extern struct value *value_coerce_to_target (struct value *arg1); 769 770extern struct value *value_coerce_array (struct value *arg1); 771 772extern struct value *value_coerce_function (struct value *arg1); 773 774extern struct value *value_ind (struct value *arg1); 775 776extern struct value *value_addr (struct value *arg1); 777 778extern struct value *value_ref (struct value *arg1, enum type_code refcode); 779 780extern struct value *value_assign (struct value *toval, 781 struct value *fromval); 782 783extern struct value *value_pos (struct value *arg1); 784 785extern struct value *value_neg (struct value *arg1); 786 787extern struct value *value_complement (struct value *arg1); 788 789extern struct value *value_struct_elt (struct value **argp, 790 struct value **args, 791 const char *name, int *static_memfuncp, 792 const char *err); 793 794extern struct value *value_struct_elt_bitpos (struct value **argp, 795 int bitpos, 796 struct type *field_type, 797 const char *err); 798 799extern struct value *value_aggregate_elt (struct type *curtype, 800 const char *name, 801 struct type *expect_type, 802 int want_address, 803 enum noside noside); 804 805extern struct value *value_static_field (struct type *type, int fieldno); 806 807enum oload_search_type { NON_METHOD, METHOD, BOTH }; 808 809extern int find_overload_match (struct value **args, int nargs, 810 const char *name, 811 enum oload_search_type method, 812 struct value **objp, struct symbol *fsym, 813 struct value **valp, struct symbol **symp, 814 int *staticp, const int no_adl, 815 enum noside noside); 816 817extern struct value *value_field (struct value *arg1, int fieldno); 818 819extern struct value *value_primitive_field (struct value *arg1, LONGEST offset, 820 int fieldno, 821 struct type *arg_type); 822 823 824extern struct type *value_rtti_indirect_type (struct value *, int *, LONGEST *, 825 int *); 826 827extern struct value *value_full_object (struct value *, struct type *, int, 828 int, int); 829 830extern struct value *value_cast_pointers (struct type *, struct value *, int); 831 832extern struct value *value_cast (struct type *type, struct value *arg2); 833 834extern struct value *value_reinterpret_cast (struct type *type, 835 struct value *arg); 836 837extern struct value *value_dynamic_cast (struct type *type, struct value *arg); 838 839extern struct value *value_zero (struct type *type, enum lval_type lv); 840 841extern struct value *value_one (struct type *type); 842 843extern struct value *value_repeat (struct value *arg1, int count); 844 845extern struct value *value_subscript (struct value *array, LONGEST index); 846 847extern struct value *value_bitstring_subscript (struct type *type, 848 struct value *bitstring, 849 LONGEST index); 850 851extern struct value *register_value_being_returned (struct type *valtype, 852 struct regcache *retbuf); 853 854extern int value_in (struct value *element, struct value *set); 855 856extern int value_bit_index (struct type *type, const gdb_byte *addr, 857 int index); 858 859extern enum return_value_convention 860struct_return_convention (struct gdbarch *gdbarch, struct value *function, 861 struct type *value_type); 862 863extern int using_struct_return (struct gdbarch *gdbarch, 864 struct value *function, 865 struct type *value_type); 866 867extern struct value *evaluate_expression (struct expression *exp); 868 869extern struct value *evaluate_type (struct expression *exp); 870 871extern struct value *evaluate_subexp (struct type *expect_type, 872 struct expression *exp, 873 int *pos, enum noside noside); 874 875extern struct value *evaluate_subexpression_type (struct expression *exp, 876 int subexp); 877 878extern void fetch_subexp_value (struct expression *exp, int *pc, 879 struct value **valp, struct value **resultp, 880 struct value **val_chain, 881 int preserve_errors); 882 883extern char *extract_field_op (struct expression *exp, int *subexp); 884 885extern struct value *evaluate_subexp_with_coercion (struct expression *, 886 int *, enum noside); 887 888extern struct value *parse_and_eval (const char *exp); 889 890extern struct value *parse_to_comma_and_eval (const char **expp); 891 892extern struct type *parse_and_eval_type (char *p, int length); 893 894extern CORE_ADDR parse_and_eval_address (const char *exp); 895 896extern LONGEST parse_and_eval_long (const char *exp); 897 898extern void unop_promote (const struct language_defn *language, 899 struct gdbarch *gdbarch, 900 struct value **arg1); 901 902extern void binop_promote (const struct language_defn *language, 903 struct gdbarch *gdbarch, 904 struct value **arg1, struct value **arg2); 905 906extern struct value *access_value_history (int num); 907 908extern struct value *value_of_internalvar (struct gdbarch *gdbarch, 909 struct internalvar *var); 910 911extern int get_internalvar_integer (struct internalvar *var, LONGEST *l); 912 913extern void set_internalvar (struct internalvar *var, struct value *val); 914 915extern void set_internalvar_integer (struct internalvar *var, LONGEST l); 916 917extern void set_internalvar_string (struct internalvar *var, 918 const char *string); 919 920extern void clear_internalvar (struct internalvar *var); 921 922extern void set_internalvar_component (struct internalvar *var, 923 LONGEST offset, 924 LONGEST bitpos, LONGEST bitsize, 925 struct value *newvalue); 926 927extern struct internalvar *lookup_only_internalvar (const char *name); 928 929extern struct internalvar *create_internalvar (const char *name); 930 931extern VEC (char_ptr) *complete_internalvar (const char *name); 932 933/* An internalvar can be dynamically computed by supplying a vector of 934 function pointers to perform various operations. */ 935 936struct internalvar_funcs 937{ 938 /* Compute the value of the variable. The DATA argument passed to 939 the function is the same argument that was passed to 940 `create_internalvar_type_lazy'. */ 941 942 struct value *(*make_value) (struct gdbarch *arch, 943 struct internalvar *var, 944 void *data); 945 946 /* Update the agent expression EXPR with bytecode to compute the 947 value. VALUE is the agent value we are updating. The DATA 948 argument passed to this function is the same argument that was 949 passed to `create_internalvar_type_lazy'. If this pointer is 950 NULL, then the internalvar cannot be compiled to an agent 951 expression. */ 952 953 void (*compile_to_ax) (struct internalvar *var, 954 struct agent_expr *expr, 955 struct axs_value *value, 956 void *data); 957 958 /* If non-NULL, this is called to destroy DATA. The DATA argument 959 passed to this function is the same argument that was passed to 960 `create_internalvar_type_lazy'. */ 961 962 void (*destroy) (void *data); 963}; 964 965extern struct internalvar *create_internalvar_type_lazy (const char *name, 966 const struct internalvar_funcs *funcs, 967 void *data); 968 969/* Compile an internal variable to an agent expression. VAR is the 970 variable to compile; EXPR and VALUE are the agent expression we are 971 updating. This will return 0 if there is no known way to compile 972 VAR, and 1 if VAR was successfully compiled. It may also throw an 973 exception on error. */ 974 975extern int compile_internalvar_to_ax (struct internalvar *var, 976 struct agent_expr *expr, 977 struct axs_value *value); 978 979extern struct internalvar *lookup_internalvar (const char *name); 980 981extern int value_equal (struct value *arg1, struct value *arg2); 982 983extern int value_equal_contents (struct value *arg1, struct value *arg2); 984 985extern int value_less (struct value *arg1, struct value *arg2); 986 987extern int value_logical_not (struct value *arg1); 988 989/* C++ */ 990 991extern struct value *value_of_this (const struct language_defn *lang); 992 993extern struct value *value_of_this_silent (const struct language_defn *lang); 994 995extern struct value *value_x_binop (struct value *arg1, struct value *arg2, 996 enum exp_opcode op, 997 enum exp_opcode otherop, 998 enum noside noside); 999 1000extern struct value *value_x_unop (struct value *arg1, enum exp_opcode op, 1001 enum noside noside); 1002 1003extern struct value *value_fn_field (struct value **arg1p, struct fn_field *f, 1004 int j, struct type *type, LONGEST offset); 1005 1006extern int binop_types_user_defined_p (enum exp_opcode op, 1007 struct type *type1, 1008 struct type *type2); 1009 1010extern int binop_user_defined_p (enum exp_opcode op, struct value *arg1, 1011 struct value *arg2); 1012 1013extern int unop_user_defined_p (enum exp_opcode op, struct value *arg1); 1014 1015extern int destructor_name_p (const char *name, struct type *type); 1016 1017extern void value_incref (struct value *val); 1018 1019extern void value_free (struct value *val); 1020 1021extern void free_all_values (void); 1022 1023extern void free_value_chain (struct value *v); 1024 1025extern void release_value (struct value *val); 1026 1027extern void release_value_or_incref (struct value *val); 1028 1029extern int record_latest_value (struct value *val); 1030 1031extern void modify_field (struct type *type, gdb_byte *addr, 1032 LONGEST fieldval, LONGEST bitpos, LONGEST bitsize); 1033 1034extern void type_print (struct type *type, const char *varstring, 1035 struct ui_file *stream, int show); 1036 1037extern std::string type_to_string (struct type *type); 1038 1039extern gdb_byte *baseclass_addr (struct type *type, int index, 1040 gdb_byte *valaddr, 1041 struct value **valuep, int *errp); 1042 1043extern void print_longest (struct ui_file *stream, int format, 1044 int use_local, LONGEST val); 1045 1046extern void print_floating (const gdb_byte *valaddr, struct type *type, 1047 struct ui_file *stream); 1048 1049extern void print_decimal_floating (const gdb_byte *valaddr, struct type *type, 1050 struct ui_file *stream); 1051 1052extern void value_print (struct value *val, struct ui_file *stream, 1053 const struct value_print_options *options); 1054 1055extern void value_print_array_elements (struct value *val, 1056 struct ui_file *stream, int format, 1057 enum val_prettyformat pretty); 1058 1059extern struct value *value_release_to_mark (const struct value *mark); 1060 1061extern void val_print (struct type *type, 1062 LONGEST embedded_offset, CORE_ADDR address, 1063 struct ui_file *stream, int recurse, 1064 struct value *val, 1065 const struct value_print_options *options, 1066 const struct language_defn *language); 1067 1068extern void common_val_print (struct value *val, 1069 struct ui_file *stream, int recurse, 1070 const struct value_print_options *options, 1071 const struct language_defn *language); 1072 1073extern int val_print_string (struct type *elttype, const char *encoding, 1074 CORE_ADDR addr, int len, 1075 struct ui_file *stream, 1076 const struct value_print_options *options); 1077 1078extern void print_variable_and_value (const char *name, 1079 struct symbol *var, 1080 struct frame_info *frame, 1081 struct ui_file *stream, 1082 int indent); 1083 1084extern void typedef_print (struct type *type, struct symbol *news, 1085 struct ui_file *stream); 1086 1087extern char *internalvar_name (const struct internalvar *var); 1088 1089extern void preserve_values (struct objfile *); 1090 1091/* From values.c */ 1092 1093extern struct value *value_copy (struct value *); 1094 1095extern struct value *value_non_lval (struct value *); 1096 1097extern void value_force_lval (struct value *, CORE_ADDR); 1098 1099extern struct value *make_cv_value (int, int, struct value *); 1100 1101extern void preserve_one_value (struct value *, struct objfile *, htab_t); 1102 1103/* From valops.c */ 1104 1105extern struct value *varying_to_slice (struct value *); 1106 1107extern struct value *value_slice (struct value *, int, int); 1108 1109extern struct value *value_literal_complex (struct value *, struct value *, 1110 struct type *); 1111 1112extern struct value *find_function_in_inferior (const char *, 1113 struct objfile **); 1114 1115extern struct value *value_allocate_space_in_inferior (int); 1116 1117extern struct value *value_subscripted_rvalue (struct value *array, 1118 LONGEST index, int lowerbound); 1119 1120/* User function handler. */ 1121 1122typedef struct value *(*internal_function_fn) (struct gdbarch *gdbarch, 1123 const struct language_defn *language, 1124 void *cookie, 1125 int argc, 1126 struct value **argv); 1127 1128void add_internal_function (const char *name, const char *doc, 1129 internal_function_fn handler, 1130 void *cookie); 1131 1132struct value *call_internal_function (struct gdbarch *gdbarch, 1133 const struct language_defn *language, 1134 struct value *function, 1135 int argc, struct value **argv); 1136 1137char *value_internal_function_name (struct value *); 1138 1139extern struct value *value_of_xmethod (struct xmethod_worker *); 1140 1141extern struct type *result_type_of_xmethod (struct value *method, 1142 int argc, struct value **argv); 1143 1144extern struct value *call_xmethod (struct value *method, 1145 int argc, struct value **argv); 1146 1147#endif /* !defined (VALUE_H) */ 1148