gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2019 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 (FRAME_H)
  21 #define FRAME_H 1
  22
  23 /* The following is the intended naming schema for frame functions.
  24    It isn't 100% consistent, but it is aproaching that.  Frame naming
  25    schema:
  26
  27    Prefixes:
  28
  29    get_frame_WHAT...(): Get WHAT from the THIS frame (functionally
  30    equivalent to THIS->next->unwind->what)
  31
  32    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  33    frame.
  34
  35    frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
  36    real caller.  Any inlined functions in NEXT's stack frame are
  37    skipped.  Use these to ignore any potentially inlined functions,
  38    e.g. inlined into the first instruction of a library trampoline.
  39
  40    get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is
  41    inlined, skip to the containing stack frame.
  42
  43    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  44    invalidate the frame / regcache afterwards) (better name more
  45    strongly hinting at its unsafeness)
  46
  47    safe_....(): Safer version of various functions, doesn't throw an
  48    error (leave this for later?).  Returns non-zero / non-NULL if the
  49    request succeeds, zero / NULL otherwize.
  50
  51    Suffixes:
  52
  53    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  54
  55    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  56    alternative is *frame_unsigned_WHAT).
  57
  58    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  59
  60    What:
  61
  62    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  63    *memory.
  64
  65    /frame/_register* (frame, regnum [, buf]): extract/return register.
  66
  67    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  68    stack *address, ...
  69
  70    */
  71
  72 #include "language.h"
  73
  74 struct symtab_and_line;
  75 struct frame_unwind;
  76 struct frame_base;
  77 struct block;
  78 struct gdbarch;
  79 struct ui_file;
  80 struct ui_out;
  81
  82 /* Status of a given frame's stack.  */
  83
  84 enum frame_id_stack_status
  85 {
  86   /* Stack address is invalid.  E.g., this frame is the outermost
  87      (i.e., _start), and the stack hasn't been setup yet.  */
  88   FID_STACK_INVALID = 0,
  89
  90   /* Stack address is valid, and is found in the stack_addr field.  */
  91   FID_STACK_VALID = 1,
  92
  93   /* Sentinel frame.  */
  94   FID_STACK_SENTINEL = 2,
  95
  96   /* Stack address is unavailable.  I.e., there's a valid stack, but
  97      we don't know where it is (because memory or registers we'd
  98      compute it from were not collected).  */
  99   FID_STACK_UNAVAILABLE = -1
 100 };
 101
 102 /* The frame object.  */
 103
 104 struct frame_info;
 105
 106 /* The frame object's ID.  This provides a per-frame unique identifier
 107    that can be used to relocate a `struct frame_info' after a target
 108    resume or a frame cache destruct.  It of course assumes that the
 109    inferior hasn't unwound the stack past that frame.  */
 110
 111 struct frame_id
 112 {
 113   /* The frame's stack address.  This shall be constant through out
 114      the lifetime of a frame.  Note that this requirement applies to
 115      not just the function body, but also the prologue and (in theory
 116      at least) the epilogue.  Since that value needs to fall either on
 117      the boundary, or within the frame's address range, the frame's
 118      outer-most address (the inner-most address of the previous frame)
 119      is used.  Watch out for all the legacy targets that still use the
 120      function pointer register or stack pointer register.  They are
 121      wrong.
 122
 123      This field is valid only if frame_id.stack_status is
 124      FID_STACK_VALID.  It will be 0 for other
 125      FID_STACK_... statuses.  */
 126   CORE_ADDR stack_addr;
 127
 128   /* The frame's code address.  This shall be constant through out the
 129      lifetime of the frame.  While the PC (a.k.a. resume address)
 130      changes as the function is executed, this code address cannot.
 131      Typically, it is set to the address of the entry point of the
 132      frame's function (as returned by get_frame_func).
 133
 134      For inlined functions (INLINE_DEPTH != 0), this is the address of
 135      the first executed instruction in the block corresponding to the
 136      inlined function.
 137
 138      This field is valid only if code_addr_p is true.  Otherwise, this
 139      frame is considered to have a wildcard code address, i.e. one that
 140      matches every address value in frame comparisons.  */
 141   CORE_ADDR code_addr;
 142
 143   /* The frame's special address.  This shall be constant through out the
 144      lifetime of the frame.  This is used for architectures that may have
 145      frames that do not change the stack but are still distinct and have
 146      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 147      stack for registers).  This field is treated as unordered - i.e. will
 148      not be used in frame ordering comparisons.
 149
 150      This field is valid only if special_addr_p is true.  Otherwise, this
 151      frame is considered to have a wildcard special address, i.e. one that
 152      matches every address value in frame comparisons.  */
 153   CORE_ADDR special_addr;
 154
 155   /* Flags to indicate the above fields have valid contents.  */
 156   ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
 157   unsigned int code_addr_p : 1;
 158   unsigned int special_addr_p : 1;
 159
 160   /* It is non-zero for a frame made up by GDB without stack data
 161      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 162      Caller of inlined function will have it zero, each more inner called frame
 163      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 164   int artificial_depth;
 165 };
 166
 167 /* Save and restore the currently selected frame.  */
 168
 169 class scoped_restore_selected_frame
 170 {
 171 public:
 172   /* Save the currently selected frame.  */
 173   scoped_restore_selected_frame ();
 174
 175   /* Restore the currently selected frame.  */
 176   ~scoped_restore_selected_frame ();
 177
 178   DISABLE_COPY_AND_ASSIGN (scoped_restore_selected_frame);
 179
 180 private:
 181
 182   /* The ID of the previously selected frame.  */
 183   struct frame_id m_fid;
 184 };
 185
 186 /* Methods for constructing and comparing Frame IDs.  */
 187
 188 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 189 extern const struct frame_id null_frame_id;
 190
 191 /* Sentinel frame.  */
 192 extern const struct frame_id sentinel_frame_id;
 193
 194 /* This means "there is no frame ID, but there is a frame".  It should be
 195    replaced by best-effort frame IDs for the outermost frame, somehow.
 196    The implementation is only special_addr_p set.  */
 197 extern const struct frame_id outer_frame_id;
 198
 199 /* Flag to control debugging.  */
 200
 201 extern unsigned int frame_debug;
 202
 203 /* Construct a frame ID.  The first parameter is the frame's constant
 204    stack address (typically the outer-bound), and the second the
 205    frame's constant code address (typically the entry point).
 206    The special identifier address is set to indicate a wild card.  */
 207 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 208                                        CORE_ADDR code_addr);
 209
 210 /* Construct a special frame ID.  The first parameter is the frame's constant
 211    stack address (typically the outer-bound), the second is the
 212    frame's constant code address (typically the entry point),
 213    and the third parameter is the frame's special identifier address.  */
 214 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 215                                                CORE_ADDR code_addr,
 216                                                CORE_ADDR special_addr);
 217
 218 /* Construct a frame ID representing a frame where the stack address
 219    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 220    address (typically the entry point).  The special identifier
 221    address is set to indicate a wild card.  */
 222 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 223
 224 /* Construct a frame ID representing a frame where the stack address
 225    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 226    address (typically the entry point).  SPECIAL_ADDR is the special
 227    identifier address.  */
 228 extern struct frame_id
 229   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 230                                             CORE_ADDR special_addr);
 231
 232 /* Construct a wild card frame ID.  The parameter is the frame's constant
 233    stack address (typically the outer-bound).  The code address as well
 234    as the special identifier address are set to indicate wild cards.  */
 235 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 236
 237 /* Returns non-zero when L is a valid frame (a valid frame has a
 238    non-zero .base).  The outermost frame is valid even without an
 239    ID.  */
 240 extern int frame_id_p (struct frame_id l);
 241
 242 /* Returns non-zero when L is a valid frame representing a frame made up by GDB
 243    without stack data representation in inferior, such as INLINE_FRAME or
 244    TAILCALL_FRAME.  */
 245 extern int frame_id_artificial_p (struct frame_id l);
 246
 247 /* Returns non-zero when L and R identify the same frame, or, if
 248    either L or R have a zero .func, then the same frame base.  */
 249 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 250
 251 /* Write the internal representation of a frame ID on the specified
 252    stream.  */
 253 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 254
 255
 256 /* Frame types.  Some are real, some are signal trampolines, and some
 257    are completely artificial (dummy).  */
 258
 259 enum frame_type
 260 {
 261   /* A true stack frame, created by the target program during normal
 262      execution.  */
 263   NORMAL_FRAME,
 264   /* A fake frame, created by GDB when performing an inferior function
 265      call.  */
 266   DUMMY_FRAME,
 267   /* A frame representing an inlined function, associated with an
 268      upcoming (prev, outer, older) NORMAL_FRAME.  */
 269   INLINE_FRAME,
 270   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 271   TAILCALL_FRAME,
 272   /* In a signal handler, various OSs handle this in various ways.
 273      The main thing is that the frame may be far from normal.  */
 274   SIGTRAMP_FRAME,
 275   /* Fake frame representing a cross-architecture call.  */
 276   ARCH_FRAME,
 277   /* Sentinel or registers frame.  This frame obtains register values
 278      direct from the inferior's registers.  */
 279   SENTINEL_FRAME
 280 };
 281
 282 /* For every stopped thread, GDB tracks two frames: current and
 283    selected.  Current frame is the inner most frame of the selected
 284    thread.  Selected frame is the one being examined by the GDB
 285    CLI (selected using `up', `down', ...).  The frames are created
 286    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 287 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 288    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 289    selected frame.  At present GDB only tracks the selected frame of
 290    the current thread.  But be warned, that might change.  */
 291 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 292    and current frame can be active.  Switching threads causes gdb to
 293    discard all that cached frame information.  Ulgh!  Instead, current
 294    and selected frame should be bound to a thread.  */
 295
 296 /* On demand, create the inner most frame using information found in
 297    the inferior.  If the inner most frame can't be created, throw an
 298    error.  */
 299 extern struct frame_info *get_current_frame (void);
 300
 301 /* Does the current target interface have enough state to be able to
 302    query the current inferior for frame info, and is the inferior in a
 303    state where that is possible?  */
 304 extern int has_stack_frames (void);
 305
 306 /* Invalidates the frame cache (this function should have been called
 307    invalidate_cached_frames).
 308
 309    FIXME: cagney/2002-11-28: There should be two methods: one that
 310    reverts the thread's selected frame back to current frame (for when
 311    the inferior resumes) and one that does not (for when the user
 312    modifies the target invalidating the frame cache).  */
 313 extern void reinit_frame_cache (void);
 314
 315 /* On demand, create the selected frame and then return it.  If the
 316    selected frame can not be created, this function prints then throws
 317    an error.  When MESSAGE is non-NULL, use it for the error message,
 318    otherwize use a generic error message.  */
 319 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 320    frame, this function always returns the current (inner most) frame.
 321    It should instead, when a thread has previously had its frame
 322    selected (but not resumed) and the frame cache invalidated, find
 323    and then return that thread's previously selected frame.  */
 324 extern struct frame_info *get_selected_frame (const char *message);
 325
 326 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 327 extern struct frame_info *get_selected_frame_if_set (void);
 328
 329 /* Select a specific frame.  NULL, apparently implies re-select the
 330    inner most frame.  */
 331 extern void select_frame (struct frame_info *);
 332
 333 /* Given a FRAME, return the next (more inner, younger) or previous
 334    (more outer, older) frame.  */
 335 extern struct frame_info *get_prev_frame (struct frame_info *);
 336 extern struct frame_info *get_next_frame (struct frame_info *);
 337
 338 /* Like get_next_frame(), but allows return of the sentinel frame.  NULL
 339    is never returned.  */
 340 extern struct frame_info *get_next_frame_sentinel_okay (struct frame_info *);
 341
 342 /* Return a "struct frame_info" corresponding to the frame that called
 343    THIS_FRAME.  Returns NULL if there is no such frame.
 344
 345    Unlike get_prev_frame, this function always tries to unwind the
 346    frame.  */
 347 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 348
 349 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 350    is not found.  */
 351 extern struct frame_info *frame_find_by_id (struct frame_id id);
 352
 353 /* Given a frame's ID, find the previous frame's ID.  Returns null_frame_id
 354    if the frame is not found.  */
 355 extern struct frame_id get_prev_frame_id_by_id (struct frame_id id);
 356
 357 /* Base attributes of a frame: */
 358
 359 /* The frame's `resume' address.  Where the program will resume in
 360    this frame.
 361
 362    This replaced: frame->pc; */
 363 extern CORE_ADDR get_frame_pc (struct frame_info *);
 364
 365 /* Same as get_frame_pc, but return a boolean indication of whether
 366    the PC is actually available, instead of throwing an error.  */
 367
 368 extern int get_frame_pc_if_available (struct frame_info *frame,
 369                                       CORE_ADDR *pc);
 370
 371 /* An address (not necessarily aligned to an instruction boundary)
 372    that falls within THIS frame's code block.
 373
 374    When a function call is the last statement in a block, the return
 375    address for the call may land at the start of the next block.
 376    Similarly, if a no-return function call is the last statement in
 377    the function, the return address may end up pointing beyond the
 378    function, and possibly at the start of the next function.
 379
 380    These methods make an allowance for this.  For call frames, this
 381    function returns the frame's PC-1 which "should" be an address in
 382    the frame's block.  */
 383
 384 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 385
 386 /* Same as get_frame_address_in_block, but returns a boolean
 387    indication of whether the frame address is determinable (when the
 388    PC is unavailable, it will not be), instead of possibly throwing an
 389    error trying to read an unavailable PC.  */
 390
 391 extern int
 392   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 393                                            CORE_ADDR *pc);
 394
 395 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 396    known as top-of-stack.  */
 397
 398 extern CORE_ADDR get_frame_sp (struct frame_info *);
 399
 400 /* Following on from the `resume' address.  Return the entry point
 401    address of the function containing that resume address, or zero if
 402    that function isn't known.  */
 403 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 404
 405 /* Same as get_frame_func, but returns a boolean indication of whether
 406    the frame function is determinable (when the PC is unavailable, it
 407    will not be), instead of possibly throwing an error trying to read
 408    an unavailable PC.  */
 409
 410 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 411
 412 /* Closely related to the resume address, various symbol table
 413    attributes that are determined by the PC.  Note that for a normal
 414    frame, the PC refers to the resume address after the return, and
 415    not the call instruction.  In such a case, the address is adjusted
 416    so that it (approximately) identifies the call site (and not the
 417    return site).
 418
 419    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 420    computed value.  Working on the assumption that the bottle-neck is
 421    in the single step code, and that code causes the frame cache to be
 422    constantly flushed, caching things in a frame is probably of little
 423    benefit.  As they say `show us the numbers'.
 424
 425    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 426    find_frame_block(), find_frame_partial_function(),
 427    find_frame_symtab(), find_frame_function().  Each will need to be
 428    carefully considered to determine if the real intent was for it to
 429    apply to the PC or the adjusted PC.  */
 430 extern symtab_and_line find_frame_sal (frame_info *frame);
 431
 432 /* Set the current source and line to the location given by frame
 433    FRAME, if possible.  */
 434
 435 void set_current_sal_from_frame (struct frame_info *);
 436
 437 /* Return the frame base (what ever that is) (DEPRECATED).
 438
 439    Old code was trying to use this single method for two conflicting
 440    purposes.  Such code needs to be updated to use either of:
 441
 442    get_frame_id: A low level frame unique identifier, that consists of
 443    both a stack and a function address, that can be used to uniquely
 444    identify a frame.  This value is determined by the frame's
 445    low-level unwinder, the stack part [typically] being the
 446    top-of-stack of the previous frame, and the function part being the
 447    function's start address.  Since the correct identification of a
 448    frameless function requires both a stack and function address,
 449    the old get_frame_base method was not sufficient.
 450
 451    get_frame_base_address: get_frame_locals_address:
 452    get_frame_args_address: A set of high-level debug-info dependant
 453    addresses that fall within the frame.  These addresses almost
 454    certainly will not match the stack address part of a frame ID (as
 455    returned by get_frame_base).
 456
 457    This replaced: frame->frame; */
 458
 459 extern CORE_ADDR get_frame_base (struct frame_info *);
 460
 461 /* Return the per-frame unique identifer.  Can be used to relocate a
 462    frame after a frame cache flush (and other similar operations).  If
 463    FI is NULL, return the null_frame_id.
 464
 465    NOTE: kettenis/20040508: These functions return a structure.  On
 466    platforms where structures are returned in static storage (vax,
 467    m68k), this may trigger compiler bugs in code like:
 468
 469    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 470
 471    where the return value from the first get_frame_id (l) gets
 472    overwritten by the second get_frame_id (r).  Please avoid writing
 473    code like this.  Use code like:
 474
 475    struct frame_id id = get_frame_id (l);
 476    if (frame_id_eq (id, get_frame_id (r)))
 477
 478    instead, since that avoids the bug.  */
 479 extern struct frame_id get_frame_id (struct frame_info *fi);
 480 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 481 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 482
 483 /* Assuming that a frame is `normal', return its base-address, or 0 if
 484    the information isn't available.  NOTE: This address is really only
 485    meaningful to the frame's high-level debug info.  */
 486 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 487
 488 /* Assuming that a frame is `normal', return the base-address of the
 489    local variables, or 0 if the information isn't available.  NOTE:
 490    This address is really only meaningful to the frame's high-level
 491    debug info.  Typically, the argument and locals share a single
 492    base-address.  */
 493 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 494
 495 /* Assuming that a frame is `normal', return the base-address of the
 496    parameter list, or 0 if that information isn't available.  NOTE:
 497    This address is really only meaningful to the frame's high-level
 498    debug info.  Typically, the argument and locals share a single
 499    base-address.  */
 500 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 501
 502 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 503    for an invalid frame).  */
 504 extern int frame_relative_level (struct frame_info *fi);
 505
 506 /* Return the frame's type.  */
 507
 508 extern enum frame_type get_frame_type (struct frame_info *);
 509
 510 /* Return the frame's program space.  */
 511 extern struct program_space *get_frame_program_space (struct frame_info *);
 512
 513 /* Unwind THIS frame's program space from the NEXT frame.  */
 514 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 515
 516 class address_space;
 517
 518 /* Return the frame's address space.  */
 519 extern const address_space *get_frame_address_space (struct frame_info *);
 520
 521 /* For frames where we can not unwind further, describe why.  */
 522
 523 enum unwind_stop_reason
 524   {
 525 #define SET(name, description) name,
 526 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 527 #define LAST_ENTRY(name) UNWIND_LAST = name,
 528 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 529
 530 #include "unwind_stop_reasons.def"
 531 #undef SET
 532 #undef FIRST_ENTRY
 533 #undef LAST_ENTRY
 534 #undef FIRST_ERROR
 535   };
 536
 537 /* Return the reason why we can't unwind past this frame.  */
 538
 539 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 540
 541 /* Translate a reason code to an informative string.  This converts the
 542    generic stop reason codes into a generic string describing the code.
 543    For a possibly frame specific string explaining the stop reason, use
 544    FRAME_STOP_REASON_STRING instead.  */
 545
 546 const char *unwind_stop_reason_to_string (enum unwind_stop_reason);
 547
 548 /* Return a possibly frame specific string explaining why the unwind
 549    stopped here.  E.g., if unwinding tripped on a memory error, this
 550    will return the error description string, which includes the address
 551    that we failed to access.  If there's no specific reason stored for
 552    a frame then a generic reason string will be returned.
 553
 554    Should only be called for frames that don't have a previous frame.  */
 555
 556 const char *frame_stop_reason_string (struct frame_info *);
 557
 558 /* Unwind the stack frame so that the value of REGNUM, in the previous
 559    (up, older) frame is returned.  If VALUEP is NULL, don't
 560    fetch/compute the value.  Instead just return the location of the
 561    value.  */
 562 extern void frame_register_unwind (frame_info *frame, int regnum,
 563                                    int *optimizedp, int *unavailablep,
 564                                    enum lval_type *lvalp,
 565                                    CORE_ADDR *addrp, int *realnump,
 566                                    gdb_byte *valuep);
 567
 568 /* Fetch a register from this, or unwind a register from the next
 569    frame.  Note that the get_frame methods are wrappers to
 570    frame->next->unwind.  They all [potentially] throw an error if the
 571    fetch fails.  The value methods never return NULL, but usually
 572    do return a lazy value.  */
 573
 574 extern void frame_unwind_register (frame_info *next_frame,
 575                                    int regnum, gdb_byte *buf);
 576 extern void get_frame_register (struct frame_info *frame,
 577                                 int regnum, gdb_byte *buf);
 578
 579 struct value *frame_unwind_register_value (frame_info *next_frame,
 580                                            int regnum);
 581 struct value *get_frame_register_value (struct frame_info *frame,
 582                                         int regnum);
 583
 584 extern LONGEST frame_unwind_register_signed (frame_info *next_frame,
 585                                              int regnum);
 586 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 587                                           int regnum);
 588 extern ULONGEST frame_unwind_register_unsigned (frame_info *frame,
 589                                                 int regnum);
 590 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 591                                              int regnum);
 592
 593 /* Read a register from this, or unwind a register from the next
 594    frame.  Note that the read_frame methods are wrappers to
 595    get_frame_register_value, that do not throw if the result is
 596    optimized out or unavailable.  */
 597
 598 extern int read_frame_register_unsigned (struct frame_info *frame,
 599                                          int regnum, ULONGEST *val);
 600
 601 /* Get the value of the register that belongs to this FRAME.  This
 602    function is a wrapper to the call sequence ``frame_register_unwind
 603    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 604    VALUEP is NULL, the registers value is not fetched/computed.  */
 605
 606 extern void frame_register (struct frame_info *frame, int regnum,
 607                             int *optimizedp, int *unavailablep,
 608                             enum lval_type *lvalp,
 609                             CORE_ADDR *addrp, int *realnump,
 610                             gdb_byte *valuep);
 611
 612 /* The reverse.  Store a register value relative to the specified
 613    frame.  Note: this call makes the frame's state undefined.  The
 614    register and frame caches must be flushed.  */
 615 extern void put_frame_register (struct frame_info *frame, int regnum,
 616                                 const gdb_byte *buf);
 617
 618 /* Read LEN bytes from one or multiple registers starting with REGNUM
 619    in frame FRAME, starting at OFFSET, into BUF.  If the register
 620    contents are optimized out or unavailable, set *OPTIMIZEDP,
 621    *UNAVAILABLEP accordingly.  */
 622 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 623                                      CORE_ADDR offset, int len,
 624                                      gdb_byte *myaddr,
 625                                      int *optimizedp, int *unavailablep);
 626
 627 /* Write LEN bytes to one or multiple registers starting with REGNUM
 628    in frame FRAME, starting at OFFSET, into BUF.  */
 629 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 630                                       CORE_ADDR offset, int len,
 631                                       const gdb_byte *myaddr);
 632
 633 /* Unwind the PC.  Strictly speaking return the resume address of the
 634    calling frame.  For GDB, `pc' is the resume address and not a
 635    specific register.  */
 636
 637 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 638
 639 /* Discard the specified frame.  Restoring the registers to the state
 640    of the caller.  */
 641 extern void frame_pop (struct frame_info *frame);
 642
 643 /* Return memory from the specified frame.  A frame knows its thread /
 644    LWP and hence can find its way down to a target.  The assumption
 645    here is that the current and previous frame share a common address
 646    space.
 647
 648    If the memory read fails, these methods throw an error.
 649
 650    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 651    methods?  That isn't clear.  Can code, for instance, assume that
 652    this and the previous frame's memory or architecture are identical?
 653    If architecture / memory changes are always separated by special
 654    adaptor frames this should be ok.  */
 655
 656 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 657                               gdb_byte *buf, int len);
 658 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 659                                         CORE_ADDR memaddr, int len);
 660 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 661                                            CORE_ADDR memaddr, int len);
 662
 663 /* Same as above, but return non-zero when the entire memory read
 664    succeeds, zero otherwize.  */
 665 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 666                                      CORE_ADDR addr, gdb_byte *buf, int len);
 667
 668 /* Return this frame's architecture.  */
 669 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 670
 671 /* Return the previous frame's architecture.  */
 672 extern struct gdbarch *frame_unwind_arch (frame_info *next_frame);
 673
 674 /* Return the previous frame's architecture, skipping inline functions.  */
 675 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 676
 677
 678 /* Values for the source flag to be used in print_frame_info_base().  */
 679 enum print_what
 680   {
 681     /* Print only the source line, like in stepi.  */
 682     SRC_LINE = -1,
 683     /* Print only the location, i.e. level, address (sometimes)
 684        function, args, file, line, line num.  */
 685     LOCATION,
 686     /* Print both of the above.  */
 687     SRC_AND_LOC,
 688     /* Print location only, but always include the address.  */
 689     LOC_AND_ADDRESS
 690   };
 691
 692 /* Allocate zero initialized memory from the frame cache obstack.
 693    Appendices to the frame info (such as the unwind cache) should
 694    allocate memory using this method.  */
 695
 696 extern void *frame_obstack_zalloc (unsigned long size);
 697 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 698   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 699 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 700   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 701
 702 class readonly_detached_regcache;
 703 /* Create a regcache, and copy the frame's registers into it.  */
 704 std::unique_ptr<readonly_detached_regcache> frame_save_as_regcache
 705     (struct frame_info *this_frame);
 706
 707 extern const struct block *get_frame_block (struct frame_info *,
 708                                             CORE_ADDR *addr_in_block);
 709
 710 /* Return the `struct block' that belongs to the selected thread's
 711    selected frame.  If the inferior has no state, return NULL.
 712
 713    NOTE: cagney/2002-11-29:
 714
 715    No state?  Does the inferior have any execution state (a core file
 716    does, an executable does not).  At present the code tests
 717    `target_has_stack' but I'm left wondering if it should test
 718    `target_has_registers' or, even, a merged target_has_state.
 719
 720    Should it look at the most recently specified SAL?  If the target
 721    has no state, should this function try to extract a block from the
 722    most recently selected SAL?  That way `list foo' would give it some
 723    sort of reference point.  Then again, perhaps that would confuse
 724    things.
 725
 726    Calls to this function can be broken down into two categories: Code
 727    that uses the selected block as an additional, but optional, data
 728    point; Code that uses the selected block as a prop, when it should
 729    have the relevant frame/block/pc explicitly passed in.
 730
 731    The latter can be eliminated by correctly parameterizing the code,
 732    the former though is more interesting.  Per the "address" command,
 733    it occurs in the CLI code and makes it possible for commands to
 734    work, even when the inferior has no state.  */
 735
 736 extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 737
 738 extern struct symbol *get_frame_function (struct frame_info *);
 739
 740 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 741
 742 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 743
 744 /* Wrapper over print_stack_frame modifying current_uiout with UIOUT for
 745    the function call.  */
 746
 747 extern void print_stack_frame_to_uiout (struct ui_out *uiout,
 748                                         struct frame_info *, int print_level,
 749                                         enum print_what print_what,
 750                                         int set_current_sal);
 751
 752 extern void print_stack_frame (struct frame_info *, int print_level,
 753                                enum print_what print_what,
 754                                int set_current_sal);
 755
 756 extern void print_frame_info (struct frame_info *, int print_level,
 757                               enum print_what print_what, int args,
 758                               int set_current_sal);
 759
 760 extern struct frame_info *block_innermost_frame (const struct block *);
 761
 762 extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
 763                                 gdb_byte *buf);
 764
 765 /* From stack.c.  */
 766
 767 extern const char print_entry_values_no[];
 768 extern const char print_entry_values_only[];
 769 extern const char print_entry_values_preferred[];
 770 extern const char print_entry_values_if_needed[];
 771 extern const char print_entry_values_both[];
 772 extern const char print_entry_values_compact[];
 773 extern const char print_entry_values_default[];
 774 extern const char *print_entry_values;
 775
 776 /* Inferior function parameter value read in from a frame.  */
 777
 778 struct frame_arg
 779 {
 780   /* Symbol for this parameter used for example for its name.  */
 781   struct symbol *sym;
 782
 783   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 784      ERROR are NULL this parameter's value should not be printed.  */
 785   struct value *val;
 786
 787   /* String containing the error message, it is more usually NULL indicating no
 788      error occured reading this parameter.  */
 789   char *error;
 790
 791   /* One of the print_entry_values_* entries as appropriate specifically for
 792      this frame_arg.  It will be different from print_entry_values.  With
 793      print_entry_values_no this frame_arg should be printed as a normal
 794      parameter.  print_entry_values_only says it should be printed as entry
 795      value parameter.  print_entry_values_compact says it should be printed as
 796      both as a normal parameter and entry values parameter having the same
 797      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 798      (in such case print_entry_values_no and print_entry_values_only is used
 799      for each parameter kind specifically.  */
 800   const char *entry_kind;
 801 };
 802
 803 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 804                             struct frame_arg *argp,
 805                             struct frame_arg *entryargp);
 806 extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
 807                               struct frame_arg *argp);
 808
 809 extern void info_args_command (const char *, int);
 810
 811 extern void info_locals_command (const char *, int);
 812
 813 extern void return_command (const char *, int);
 814
 815 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 816    If sniffing fails, the caller should be sure to call
 817    frame_cleanup_after_sniffer.  */
 818
 819 extern void frame_prepare_for_sniffer (struct frame_info *frame,
 820                                        const struct frame_unwind *unwind);
 821
 822 /* Clean up after a failed (wrong unwinder) attempt to unwind past
 823    FRAME.  */
 824
 825 extern void frame_cleanup_after_sniffer (struct frame_info *frame);
 826
 827 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 828
 829    You might think that calls to this function can simply be replaced by a
 830    call to get_selected_frame().
 831
 832    Unfortunately, it isn't that easy.
 833
 834    The relevant code needs to be audited to determine if it is
 835    possible (or practical) to instead pass the applicable frame in as a
 836    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 837    the deprecated_selected_frame global, while its replacement,
 838    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 839    The only real exceptions occur at the edge (in the CLI code) where
 840    user commands need to pick up the selected frame before proceeding.
 841
 842    There are also some functions called with a NULL frame meaning either "the
 843    program is not running" or "use the selected frame".
 844
 845    This is important.  GDB is trying to stamp out the hack:
 846
 847    saved_frame = deprecated_safe_get_selected_frame ();
 848    select_frame (...);
 849    hack_using_global_selected_frame ();
 850    select_frame (saved_frame);
 851
 852    Take care!
 853
 854    This function calls get_selected_frame if the inferior should have a
 855    frame, or returns NULL otherwise.  */
 856
 857 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 858
 859 /* Create a frame using the specified BASE and PC.  */
 860
 861 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 862
 863 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 864    otherwise.  */
 865
 866 extern int frame_unwinder_is (struct frame_info *fi,
 867                               const struct frame_unwind *unwinder);
 868
 869 /* Return the language of FRAME.  */
 870
 871 extern enum language get_frame_language (struct frame_info *frame);
 872
 873 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 874    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 875    chain.  */
 876
 877 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 878
 879 /* Return the first frame above FRAME or FRAME of which the code is
 880    writable.  */
 881
 882 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 883
 884 #endif /* !defined (FRAME_H)  */