gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2020 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 approaching 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 true / non-NULL if the request
  49    succeeds, false / NULL otherwise.
  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 #include "cli/cli-option.h"
  74
  75 struct symtab_and_line;
  76 struct frame_unwind;
  77 struct frame_base;
  78 struct block;
  79 struct gdbarch;
  80 struct ui_file;
  81 struct ui_out;
  82 struct frame_print_options;
  83
  84 /* Status of a given frame's stack.  */
  85
  86 enum frame_id_stack_status
  87 {
  88   /* Stack address is invalid.  */
  89   FID_STACK_INVALID = 0,
  90
  91   /* Stack address is valid, and is found in the stack_addr field.  */
  92   FID_STACK_VALID = 1,
  93
  94   /* Sentinel frame.  */
  95   FID_STACK_SENTINEL = 2,
  96
  97   /* Outer frame.  Since a frame's stack address is typically defined as the
  98      value the stack pointer had prior to the activation of the frame, an outer
  99      frame doesn't have a stack address.  The frame ids of frames inlined in the
 100      outer frame are also of this type.  */
 101   FID_STACK_OUTER = 3,
 102
 103   /* Stack address is unavailable.  I.e., there's a valid stack, but
 104      we don't know where it is (because memory or registers we'd
 105      compute it from were not collected).  */
 106   FID_STACK_UNAVAILABLE = -1
 107 };
 108
 109 /* The frame object.  */
 110
 111 struct frame_info;
 112
 113 /* The frame object's ID.  This provides a per-frame unique identifier
 114    that can be used to relocate a `struct frame_info' after a target
 115    resume or a frame cache destruct.  It of course assumes that the
 116    inferior hasn't unwound the stack past that frame.  */
 117
 118 struct frame_id
 119 {
 120   /* The frame's stack address.  This shall be constant through out
 121      the lifetime of a frame.  Note that this requirement applies to
 122      not just the function body, but also the prologue and (in theory
 123      at least) the epilogue.  Since that value needs to fall either on
 124      the boundary, or within the frame's address range, the frame's
 125      outer-most address (the inner-most address of the previous frame)
 126      is used.  Watch out for all the legacy targets that still use the
 127      function pointer register or stack pointer register.  They are
 128      wrong.
 129
 130      This field is valid only if frame_id.stack_status is
 131      FID_STACK_VALID.  It will be 0 for other
 132      FID_STACK_... statuses.  */
 133   CORE_ADDR stack_addr;
 134
 135   /* The frame's code address.  This shall be constant through out the
 136      lifetime of the frame.  While the PC (a.k.a. resume address)
 137      changes as the function is executed, this code address cannot.
 138      Typically, it is set to the address of the entry point of the
 139      frame's function (as returned by get_frame_func).
 140
 141      For inlined functions (INLINE_DEPTH != 0), this is the address of
 142      the first executed instruction in the block corresponding to the
 143      inlined function.
 144
 145      This field is valid only if code_addr_p is true.  Otherwise, this
 146      frame is considered to have a wildcard code address, i.e. one that
 147      matches every address value in frame comparisons.  */
 148   CORE_ADDR code_addr;
 149
 150   /* The frame's special address.  This shall be constant through out the
 151      lifetime of the frame.  This is used for architectures that may have
 152      frames that do not change the stack but are still distinct and have
 153      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 154      stack for registers).  This field is treated as unordered - i.e. will
 155      not be used in frame ordering comparisons.
 156
 157      This field is valid only if special_addr_p is true.  Otherwise, this
 158      frame is considered to have a wildcard special address, i.e. one that
 159      matches every address value in frame comparisons.  */
 160   CORE_ADDR special_addr;
 161
 162   /* Flags to indicate the above fields have valid contents.  */
 163   ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
 164   unsigned int code_addr_p : 1;
 165   unsigned int special_addr_p : 1;
 166
 167   /* It is non-zero for a frame made up by GDB without stack data
 168      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 169      Caller of inlined function will have it zero, each more inner called frame
 170      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 171   int artificial_depth;
 172 };
 173
 174 /* Save and restore the currently selected frame.  */
 175
 176 class scoped_restore_selected_frame
 177 {
 178 public:
 179   /* Save the currently selected frame.  */
 180   scoped_restore_selected_frame ();
 181
 182   /* Restore the currently selected frame.  */
 183   ~scoped_restore_selected_frame ();
 184
 185   DISABLE_COPY_AND_ASSIGN (scoped_restore_selected_frame);
 186
 187 private:
 188
 189   /* The ID of the previously selected frame.  */
 190   struct frame_id m_fid;
 191 };
 192
 193 /* Methods for constructing and comparing Frame IDs.  */
 194
 195 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 196 extern const struct frame_id null_frame_id;
 197
 198 /* Sentinel frame.  */
 199 extern const struct frame_id sentinel_frame_id;
 200
 201 /* This means "there is no frame ID, but there is a frame".  It should be
 202    replaced by best-effort frame IDs for the outermost frame, somehow.
 203    The implementation is only special_addr_p set.  */
 204 extern const struct frame_id outer_frame_id;
 205
 206 /* Flag to control debugging.  */
 207
 208 extern unsigned int frame_debug;
 209
 210 /* Construct a frame ID.  The first parameter is the frame's constant
 211    stack address (typically the outer-bound), and the second the
 212    frame's constant code address (typically the entry point).
 213    The special identifier address is set to indicate a wild card.  */
 214 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 215                                        CORE_ADDR code_addr);
 216
 217 /* Construct a special frame ID.  The first parameter is the frame's constant
 218    stack address (typically the outer-bound), the second is the
 219    frame's constant code address (typically the entry point),
 220    and the third parameter is the frame's special identifier address.  */
 221 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 222                                                CORE_ADDR code_addr,
 223                                                CORE_ADDR special_addr);
 224
 225 /* Construct a frame ID representing a frame where the stack address
 226    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 227    address (typically the entry point).  The special identifier
 228    address is set to indicate a wild card.  */
 229 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 230
 231 /* Construct a frame ID representing a frame where the stack address
 232    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 233    address (typically the entry point).  SPECIAL_ADDR is the special
 234    identifier address.  */
 235 extern struct frame_id
 236   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 237                                             CORE_ADDR special_addr);
 238
 239 /* Construct a wild card frame ID.  The parameter is the frame's constant
 240    stack address (typically the outer-bound).  The code address as well
 241    as the special identifier address are set to indicate wild cards.  */
 242 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 243
 244 /* Returns true when L is a valid frame.  */
 245 extern bool frame_id_p (frame_id l);
 246
 247 /* Returns true when L is a valid frame representing a frame made up by GDB
 248    without stack data representation in inferior, such as INLINE_FRAME or
 249    TAILCALL_FRAME.  */
 250 extern bool frame_id_artificial_p (frame_id l);
 251
 252 /* Returns true when L and R identify the same frame.  */
 253 extern bool frame_id_eq (frame_id l, frame_id r);
 254
 255 /* Write the internal representation of a frame ID on the specified
 256    stream.  */
 257 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 258
 259
 260 /* Frame types.  Some are real, some are signal trampolines, and some
 261    are completely artificial (dummy).  */
 262
 263 enum frame_type
 264 {
 265   /* A true stack frame, created by the target program during normal
 266      execution.  */
 267   NORMAL_FRAME,
 268   /* A fake frame, created by GDB when performing an inferior function
 269      call.  */
 270   DUMMY_FRAME,
 271   /* A frame representing an inlined function, associated with an
 272      upcoming (prev, outer, older) NORMAL_FRAME.  */
 273   INLINE_FRAME,
 274   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 275   TAILCALL_FRAME,
 276   /* In a signal handler, various OSs handle this in various ways.
 277      The main thing is that the frame may be far from normal.  */
 278   SIGTRAMP_FRAME,
 279   /* Fake frame representing a cross-architecture call.  */
 280   ARCH_FRAME,
 281   /* Sentinel or registers frame.  This frame obtains register values
 282      direct from the inferior's registers.  */
 283   SENTINEL_FRAME
 284 };
 285
 286 /* For every stopped thread, GDB tracks two frames: current and
 287    selected.  Current frame is the inner most frame of the selected
 288    thread.  Selected frame is the one being examined by the GDB
 289    CLI (selected using `up', `down', ...).  The frames are created
 290    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 291 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 292    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 293    selected frame.  At present GDB only tracks the selected frame of
 294    the current thread.  But be warned, that might change.  */
 295 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 296    and current frame can be active.  Switching threads causes gdb to
 297    discard all that cached frame information.  Ulgh!  Instead, current
 298    and selected frame should be bound to a thread.  */
 299
 300 /* On demand, create the inner most frame using information found in
 301    the inferior.  If the inner most frame can't be created, throw an
 302    error.  */
 303 extern struct frame_info *get_current_frame (void);
 304
 305 /* Does the current target interface have enough state to be able to
 306    query the current inferior for frame info, and is the inferior in a
 307    state where that is possible?  */
 308 extern bool has_stack_frames ();
 309
 310 /* Invalidates the frame cache (this function should have been called
 311    invalidate_cached_frames).
 312
 313    FIXME: cagney/2002-11-28: There should be two methods: one that
 314    reverts the thread's selected frame back to current frame (for when
 315    the inferior resumes) and one that does not (for when the user
 316    modifies the target invalidating the frame cache).  */
 317 extern void reinit_frame_cache (void);
 318
 319 /* On demand, create the selected frame and then return it.  If the
 320    selected frame can not be created, this function prints then throws
 321    an error.  When MESSAGE is non-NULL, use it for the error message,
 322    otherwise use a generic error message.  */
 323 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 324    frame, this function always returns the current (inner most) frame.
 325    It should instead, when a thread has previously had its frame
 326    selected (but not resumed) and the frame cache invalidated, find
 327    and then return that thread's previously selected frame.  */
 328 extern struct frame_info *get_selected_frame (const char *message);
 329
 330 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 331 extern struct frame_info *get_selected_frame_if_set (void);
 332
 333 /* Select a specific frame.  NULL, apparently implies re-select the
 334    inner most frame.  */
 335 extern void select_frame (struct frame_info *);
 336
 337 /* Given a FRAME, return the next (more inner, younger) or previous
 338    (more outer, older) frame.  */
 339 extern struct frame_info *get_prev_frame (struct frame_info *);
 340 extern struct frame_info *get_next_frame (struct frame_info *);
 341
 342 /* Like get_next_frame(), but allows return of the sentinel frame.  NULL
 343    is never returned.  */
 344 extern struct frame_info *get_next_frame_sentinel_okay (struct frame_info *);
 345
 346 /* Return a "struct frame_info" corresponding to the frame that called
 347    THIS_FRAME.  Returns NULL if there is no such frame.
 348
 349    Unlike get_prev_frame, this function always tries to unwind the
 350    frame.  */
 351 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 352
 353 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 354    is not found.  */
 355 extern struct frame_info *frame_find_by_id (struct frame_id id);
 356
 357 /* Given a frame's ID, find the previous frame's ID.  Returns null_frame_id
 358    if the frame is not found.  */
 359 extern struct frame_id get_prev_frame_id_by_id (struct frame_id id);
 360
 361 /* Base attributes of a frame: */
 362
 363 /* The frame's `resume' address.  Where the program will resume in
 364    this frame.
 365
 366    This replaced: frame->pc; */
 367 extern CORE_ADDR get_frame_pc (struct frame_info *);
 368
 369 /* Same as get_frame_pc, but return a boolean indication of whether
 370    the PC is actually available, instead of throwing an error.  */
 371
 372 extern bool get_frame_pc_if_available (frame_info *frame, CORE_ADDR *pc);
 373
 374 /* An address (not necessarily aligned to an instruction boundary)
 375    that falls within THIS frame's code block.
 376
 377    When a function call is the last statement in a block, the return
 378    address for the call may land at the start of the next block.
 379    Similarly, if a no-return function call is the last statement in
 380    the function, the return address may end up pointing beyond the
 381    function, and possibly at the start of the next function.
 382
 383    These methods make an allowance for this.  For call frames, this
 384    function returns the frame's PC-1 which "should" be an address in
 385    the frame's block.  */
 386
 387 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 388
 389 /* Same as get_frame_address_in_block, but returns a boolean
 390    indication of whether the frame address is determinable (when the
 391    PC is unavailable, it will not be), instead of possibly throwing an
 392    error trying to read an unavailable PC.  */
 393
 394 extern bool get_frame_address_in_block_if_available (frame_info *this_frame,
 395                                                      CORE_ADDR *pc);
 396
 397 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 398    known as top-of-stack.  */
 399
 400 extern CORE_ADDR get_frame_sp (struct frame_info *);
 401
 402 /* Following on from the `resume' address.  Return the entry point
 403    address of the function containing that resume address, or zero if
 404    that function isn't known.  */
 405 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 406
 407 /* Same as get_frame_func, but returns a boolean indication of whether
 408    the frame function is determinable (when the PC is unavailable, it
 409    will not be), instead of possibly throwing an error trying to read
 410    an unavailable PC.  */
 411
 412 extern bool get_frame_func_if_available (frame_info *fi, CORE_ADDR *);
 413
 414 /* Closely related to the resume address, various symbol table
 415    attributes that are determined by the PC.  Note that for a normal
 416    frame, the PC refers to the resume address after the return, and
 417    not the call instruction.  In such a case, the address is adjusted
 418    so that it (approximately) identifies the call site (and not the
 419    return site).
 420
 421    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 422    computed value.  Working on the assumption that the bottle-neck is
 423    in the single step code, and that code causes the frame cache to be
 424    constantly flushed, caching things in a frame is probably of little
 425    benefit.  As they say `show us the numbers'.
 426
 427    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 428    find_frame_block(), find_frame_partial_function(),
 429    find_frame_symtab(), find_frame_function().  Each will need to be
 430    carefully considered to determine if the real intent was for it to
 431    apply to the PC or the adjusted PC.  */
 432 extern symtab_and_line find_frame_sal (frame_info *frame);
 433
 434 /* Set the current source and line to the location given by frame
 435    FRAME, if possible.  */
 436
 437 void set_current_sal_from_frame (struct frame_info *);
 438
 439 /* Return the frame base (what ever that is) (DEPRECATED).
 440
 441    Old code was trying to use this single method for two conflicting
 442    purposes.  Such code needs to be updated to use either of:
 443
 444    get_frame_id: A low level frame unique identifier, that consists of
 445    both a stack and a function address, that can be used to uniquely
 446    identify a frame.  This value is determined by the frame's
 447    low-level unwinder, the stack part [typically] being the
 448    top-of-stack of the previous frame, and the function part being the
 449    function's start address.  Since the correct identification of a
 450    frameless function requires both a stack and function address,
 451    the old get_frame_base method was not sufficient.
 452
 453    get_frame_base_address: get_frame_locals_address:
 454    get_frame_args_address: A set of high-level debug-info dependant
 455    addresses that fall within the frame.  These addresses almost
 456    certainly will not match the stack address part of a frame ID (as
 457    returned by get_frame_base).
 458
 459    This replaced: frame->frame; */
 460
 461 extern CORE_ADDR get_frame_base (struct frame_info *);
 462
 463 /* Return the per-frame unique identifer.  Can be used to relocate a
 464    frame after a frame cache flush (and other similar operations).  If
 465    FI is NULL, return the null_frame_id.
 466
 467    NOTE: kettenis/20040508: These functions return a structure.  On
 468    platforms where structures are returned in static storage (vax,
 469    m68k), this may trigger compiler bugs in code like:
 470
 471    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 472
 473    where the return value from the first get_frame_id (l) gets
 474    overwritten by the second get_frame_id (r).  Please avoid writing
 475    code like this.  Use code like:
 476
 477    struct frame_id id = get_frame_id (l);
 478    if (frame_id_eq (id, get_frame_id (r)))
 479
 480    instead, since that avoids the bug.  */
 481 extern struct frame_id get_frame_id (struct frame_info *fi);
 482 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 483 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 484
 485 /* Assuming that a frame is `normal', return its base-address, or 0 if
 486    the information isn't available.  NOTE: This address is really only
 487    meaningful to the frame's high-level debug info.  */
 488 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 489
 490 /* Assuming that a frame is `normal', return the base-address of the
 491    local variables, or 0 if the information isn't available.  NOTE:
 492    This address is really only meaningful to the frame's high-level
 493    debug info.  Typically, the argument and locals share a single
 494    base-address.  */
 495 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 496
 497 /* Assuming that a frame is `normal', return the base-address of the
 498    parameter list, or 0 if that information isn't available.  NOTE:
 499    This address is really only meaningful to the frame's high-level
 500    debug info.  Typically, the argument and locals share a single
 501    base-address.  */
 502 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 503
 504 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 505    for an invalid frame).  */
 506 extern int frame_relative_level (struct frame_info *fi);
 507
 508 /* Return the frame's type.  */
 509
 510 extern enum frame_type get_frame_type (struct frame_info *);
 511
 512 /* Return the frame's program space.  */
 513 extern struct program_space *get_frame_program_space (struct frame_info *);
 514
 515 /* Unwind THIS frame's program space from the NEXT frame.  */
 516 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 517
 518 class address_space;
 519
 520 /* Return the frame's address space.  */
 521 extern const address_space *get_frame_address_space (struct frame_info *);
 522
 523 /* For frames where we can not unwind further, describe why.  */
 524
 525 enum unwind_stop_reason
 526   {
 527 #define SET(name, description) name,
 528 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 529 #define LAST_ENTRY(name) UNWIND_LAST = name,
 530 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 531
 532 #include "unwind_stop_reasons.def"
 533 #undef SET
 534 #undef FIRST_ENTRY
 535 #undef LAST_ENTRY
 536 #undef FIRST_ERROR
 537   };
 538
 539 /* Return the reason why we can't unwind past this frame.  */
 540
 541 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 542
 543 /* Translate a reason code to an informative string.  This converts the
 544    generic stop reason codes into a generic string describing the code.
 545    For a possibly frame specific string explaining the stop reason, use
 546    FRAME_STOP_REASON_STRING instead.  */
 547
 548 const char *unwind_stop_reason_to_string (enum unwind_stop_reason);
 549
 550 /* Return a possibly frame specific string explaining why the unwind
 551    stopped here.  E.g., if unwinding tripped on a memory error, this
 552    will return the error description string, which includes the address
 553    that we failed to access.  If there's no specific reason stored for
 554    a frame then a generic reason string will be returned.
 555
 556    Should only be called for frames that don't have a previous frame.  */
 557
 558 const char *frame_stop_reason_string (struct frame_info *);
 559
 560 /* Unwind the stack frame so that the value of REGNUM, in the previous
 561    (up, older) frame is returned.  If VALUEP is NULL, don't
 562    fetch/compute the value.  Instead just return the location of the
 563    value.  */
 564 extern void frame_register_unwind (frame_info *frame, int regnum,
 565                                    int *optimizedp, int *unavailablep,
 566                                    enum lval_type *lvalp,
 567                                    CORE_ADDR *addrp, int *realnump,
 568                                    gdb_byte *valuep);
 569
 570 /* Fetch a register from this, or unwind a register from the next
 571    frame.  Note that the get_frame methods are wrappers to
 572    frame->next->unwind.  They all [potentially] throw an error if the
 573    fetch fails.  The value methods never return NULL, but usually
 574    do return a lazy value.  */
 575
 576 extern void frame_unwind_register (frame_info *next_frame,
 577                                    int regnum, gdb_byte *buf);
 578 extern void get_frame_register (struct frame_info *frame,
 579                                 int regnum, gdb_byte *buf);
 580
 581 struct value *frame_unwind_register_value (frame_info *next_frame,
 582                                            int regnum);
 583 struct value *get_frame_register_value (struct frame_info *frame,
 584                                         int regnum);
 585
 586 extern LONGEST frame_unwind_register_signed (frame_info *next_frame,
 587                                              int regnum);
 588 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 589                                           int regnum);
 590 extern ULONGEST frame_unwind_register_unsigned (frame_info *frame,
 591                                                 int regnum);
 592 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 593                                              int regnum);
 594
 595 /* Read a register from this, or unwind a register from the next
 596    frame.  Note that the read_frame methods are wrappers to
 597    get_frame_register_value, that do not throw if the result is
 598    optimized out or unavailable.  */
 599
 600 extern bool read_frame_register_unsigned (frame_info *frame,
 601                                           int regnum, ULONGEST *val);
 602
 603 /* Get the value of the register that belongs to this FRAME.  This
 604    function is a wrapper to the call sequence ``frame_register_unwind
 605    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 606    VALUEP is NULL, the registers value is not fetched/computed.  */
 607
 608 extern void frame_register (struct frame_info *frame, int regnum,
 609                             int *optimizedp, int *unavailablep,
 610                             enum lval_type *lvalp,
 611                             CORE_ADDR *addrp, int *realnump,
 612                             gdb_byte *valuep);
 613
 614 /* The reverse.  Store a register value relative to the specified
 615    frame.  Note: this call makes the frame's state undefined.  The
 616    register and frame caches must be flushed.  */
 617 extern void put_frame_register (struct frame_info *frame, int regnum,
 618                                 const gdb_byte *buf);
 619
 620 /* Read LEN bytes from one or multiple registers starting with REGNUM
 621    in frame FRAME, starting at OFFSET, into BUF.  If the register
 622    contents are optimized out or unavailable, set *OPTIMIZEDP,
 623    *UNAVAILABLEP accordingly.  */
 624 extern bool get_frame_register_bytes (frame_info *frame, int regnum,
 625                                       CORE_ADDR offset, int len,
 626                                       gdb_byte *myaddr,
 627                                       int *optimizedp, int *unavailablep);
 628
 629 /* Write LEN bytes to one or multiple registers starting with REGNUM
 630    in frame FRAME, starting at OFFSET, into BUF.  */
 631 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 632                                       CORE_ADDR offset, int len,
 633                                       const gdb_byte *myaddr);
 634
 635 /* Unwind the PC.  Strictly speaking return the resume address of the
 636    calling frame.  For GDB, `pc' is the resume address and not a
 637    specific register.  */
 638
 639 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 640
 641 /* Discard the specified frame.  Restoring the registers to the state
 642    of the caller.  */
 643 extern void frame_pop (struct frame_info *frame);
 644
 645 /* Return memory from the specified frame.  A frame knows its thread /
 646    LWP and hence can find its way down to a target.  The assumption
 647    here is that the current and previous frame share a common address
 648    space.
 649
 650    If the memory read fails, these methods throw an error.
 651
 652    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 653    methods?  That isn't clear.  Can code, for instance, assume that
 654    this and the previous frame's memory or architecture are identical?
 655    If architecture / memory changes are always separated by special
 656    adaptor frames this should be ok.  */
 657
 658 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 659                               gdb_byte *buf, int len);
 660 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 661                                         CORE_ADDR memaddr, int len);
 662 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 663                                            CORE_ADDR memaddr, int len);
 664
 665 /* Same as above, but return true zero when the entire memory read
 666    succeeds, false otherwise.  */
 667 extern bool safe_frame_unwind_memory (frame_info *this_frame, CORE_ADDR addr,
 668                                       gdb_byte *buf, int len);
 669
 670 /* Return this frame's architecture.  */
 671 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 672
 673 /* Return the previous frame's architecture.  */
 674 extern struct gdbarch *frame_unwind_arch (frame_info *next_frame);
 675
 676 /* Return the previous frame's architecture, skipping inline functions.  */
 677 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 678
 679
 680 /* Values for the source flag to be used in print_frame_info ().
 681    For all the cases below, the address is never printed if
 682    'set print address' is off.  When 'set print address' is on,
 683    the address is printed if the program counter is not at the
 684    beginning of the source line of the frame
 685    and PRINT_WHAT is != LOC_AND_ADDRESS.  */
 686 enum print_what
 687   {
 688     /* Print only the address, source line, like in stepi.  */
 689     SRC_LINE = -1,
 690     /* Print only the location, i.e. level, address,
 691        function, args (as controlled by 'set print frame-arguments'),
 692        file, line, line num.  */
 693     LOCATION,
 694     /* Print both of the above.  */
 695     SRC_AND_LOC,
 696     /* Print location only, print the address even if the program counter
 697        is at the beginning of the source line.  */
 698     LOC_AND_ADDRESS,
 699     /* Print only level and function,
 700        i.e. location only, without address, file, line, line num.  */
 701     SHORT_LOCATION
 702   };
 703
 704 /* Allocate zero initialized memory from the frame cache obstack.
 705    Appendices to the frame info (such as the unwind cache) should
 706    allocate memory using this method.  */
 707
 708 extern void *frame_obstack_zalloc (unsigned long size);
 709 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 710   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 711 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 712   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 713
 714 class readonly_detached_regcache;
 715 /* Create a regcache, and copy the frame's registers into it.  */
 716 std::unique_ptr<readonly_detached_regcache> frame_save_as_regcache
 717     (struct frame_info *this_frame);
 718
 719 extern const struct block *get_frame_block (struct frame_info *,
 720                                             CORE_ADDR *addr_in_block);
 721
 722 /* Return the `struct block' that belongs to the selected thread's
 723    selected frame.  If the inferior has no state, return NULL.
 724
 725    NOTE: cagney/2002-11-29:
 726
 727    No state?  Does the inferior have any execution state (a core file
 728    does, an executable does not).  At present the code tests
 729    `target_has_stack' but I'm left wondering if it should test
 730    `target_has_registers' or, even, a merged target_has_state.
 731
 732    Should it look at the most recently specified SAL?  If the target
 733    has no state, should this function try to extract a block from the
 734    most recently selected SAL?  That way `list foo' would give it some
 735    sort of reference point.  Then again, perhaps that would confuse
 736    things.
 737
 738    Calls to this function can be broken down into two categories: Code
 739    that uses the selected block as an additional, but optional, data
 740    point; Code that uses the selected block as a prop, when it should
 741    have the relevant frame/block/pc explicitly passed in.
 742
 743    The latter can be eliminated by correctly parameterizing the code,
 744    the former though is more interesting.  Per the "address" command,
 745    it occurs in the CLI code and makes it possible for commands to
 746    work, even when the inferior has no state.  */
 747
 748 extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 749
 750 extern struct symbol *get_frame_function (struct frame_info *);
 751
 752 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 753
 754 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 755
 756 /* Wrapper over print_stack_frame modifying current_uiout with UIOUT for
 757    the function call.  */
 758
 759 extern void print_stack_frame_to_uiout (struct ui_out *uiout,
 760                                         struct frame_info *, int print_level,
 761                                         enum print_what print_what,
 762                                         int set_current_sal);
 763
 764 extern void print_stack_frame (struct frame_info *, int print_level,
 765                                enum print_what print_what,
 766                                int set_current_sal);
 767
 768 extern void print_frame_info (const frame_print_options &fp_opts,
 769                               struct frame_info *, int print_level,
 770                               enum print_what print_what, int args,
 771                               int set_current_sal);
 772
 773 extern struct frame_info *block_innermost_frame (const struct block *);
 774
 775 extern bool deprecated_frame_register_read (frame_info *frame, int regnum,
 776                                             gdb_byte *buf);
 777
 778 /* From stack.c.  */
 779
 780 /* The possible choices of "set print frame-arguments".  */
 781 extern const char print_frame_arguments_all[];
 782 extern const char print_frame_arguments_scalars[];
 783 extern const char print_frame_arguments_none[];
 784
 785 /* The possible choices of "set print frame-info".  */
 786 extern const char print_frame_info_auto[];
 787 extern const char print_frame_info_source_line[];
 788 extern const char print_frame_info_location[];
 789 extern const char print_frame_info_source_and_location[];
 790 extern const char print_frame_info_location_and_address[];
 791 extern const char print_frame_info_short_location[];
 792
 793 /* The possible choices of "set print entry-values".  */
 794 extern const char print_entry_values_no[];
 795 extern const char print_entry_values_only[];
 796 extern const char print_entry_values_preferred[];
 797 extern const char print_entry_values_if_needed[];
 798 extern const char print_entry_values_both[];
 799 extern const char print_entry_values_compact[];
 800 extern const char print_entry_values_default[];
 801
 802 /* Data for the frame-printing "set print" settings exposed as command
 803    options.  */
 804
 805 struct frame_print_options
 806 {
 807   const char *print_frame_arguments = print_frame_arguments_scalars;
 808   const char *print_frame_info = print_frame_info_auto;
 809   const char *print_entry_values = print_entry_values_default;
 810
 811   /* If true, don't invoke pretty-printers for frame
 812      arguments.  */
 813   bool print_raw_frame_arguments;
 814 };
 815
 816 /* The values behind the global "set print ..." settings.  */
 817 extern frame_print_options user_frame_print_options;
 818
 819 /* Inferior function parameter value read in from a frame.  */
 820
 821 struct frame_arg
 822 {
 823   /* Symbol for this parameter used for example for its name.  */
 824   struct symbol *sym = nullptr;
 825
 826   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 827      ERROR are NULL this parameter's value should not be printed.  */
 828   struct value *val = nullptr;
 829
 830   /* String containing the error message, it is more usually NULL indicating no
 831      error occured reading this parameter.  */
 832   gdb::unique_xmalloc_ptr<char> error;
 833
 834   /* One of the print_entry_values_* entries as appropriate specifically for
 835      this frame_arg.  It will be different from print_entry_values.  With
 836      print_entry_values_no this frame_arg should be printed as a normal
 837      parameter.  print_entry_values_only says it should be printed as entry
 838      value parameter.  print_entry_values_compact says it should be printed as
 839      both as a normal parameter and entry values parameter having the same
 840      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 841      (in such case print_entry_values_no and print_entry_values_only is used
 842      for each parameter kind specifically.  */
 843   const char *entry_kind = nullptr;
 844 };
 845
 846 extern void read_frame_arg (const frame_print_options &fp_opts,
 847                             symbol *sym, frame_info *frame,
 848                             struct frame_arg *argp,
 849                             struct frame_arg *entryargp);
 850 extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
 851                               struct frame_arg *argp);
 852
 853 extern void info_args_command (const char *, int);
 854
 855 extern void info_locals_command (const char *, int);
 856
 857 extern void return_command (const char *, int);
 858
 859 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 860    If sniffing fails, the caller should be sure to call
 861    frame_cleanup_after_sniffer.  */
 862
 863 extern void frame_prepare_for_sniffer (struct frame_info *frame,
 864                                        const struct frame_unwind *unwind);
 865
 866 /* Clean up after a failed (wrong unwinder) attempt to unwind past
 867    FRAME.  */
 868
 869 extern void frame_cleanup_after_sniffer (struct frame_info *frame);
 870
 871 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 872
 873    You might think that calls to this function can simply be replaced by a
 874    call to get_selected_frame().
 875
 876    Unfortunately, it isn't that easy.
 877
 878    The relevant code needs to be audited to determine if it is
 879    possible (or practical) to instead pass the applicable frame in as a
 880    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 881    the deprecated_selected_frame global, while its replacement,
 882    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 883    The only real exceptions occur at the edge (in the CLI code) where
 884    user commands need to pick up the selected frame before proceeding.
 885
 886    There are also some functions called with a NULL frame meaning either "the
 887    program is not running" or "use the selected frame".
 888
 889    This is important.  GDB is trying to stamp out the hack:
 890
 891    saved_frame = deprecated_safe_get_selected_frame ();
 892    select_frame (...);
 893    hack_using_global_selected_frame ();
 894    select_frame (saved_frame);
 895
 896    Take care!
 897
 898    This function calls get_selected_frame if the inferior should have a
 899    frame, or returns NULL otherwise.  */
 900
 901 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 902
 903 /* Create a frame using the specified BASE and PC.  */
 904
 905 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 906
 907 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 908    otherwise.  */
 909
 910 extern bool frame_unwinder_is (frame_info *fi, const frame_unwind *unwinder);
 911
 912 /* Return the language of FRAME.  */
 913
 914 extern enum language get_frame_language (struct frame_info *frame);
 915
 916 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 917    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 918    chain.  */
 919
 920 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 921
 922 /* Return the first frame above FRAME or FRAME of which the code is
 923    writable.  */
 924
 925 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 926
 927 /* Data for the "set backtrace" settings.  */
 928
 929 struct set_backtrace_options
 930 {
 931   /* Flag to indicate whether backtraces should continue past
 932      main.  */
 933   bool backtrace_past_main = false;
 934
 935   /* Flag to indicate whether backtraces should continue past
 936      entry.  */
 937   bool backtrace_past_entry = false;
 938
 939   /* Upper bound on the number of backtrace levels.  Note this is not
 940      exposed as a command option, because "backtrace" and "frame
 941      apply" already have other means to set a frame count limit.  */
 942   unsigned int backtrace_limit = UINT_MAX;
 943 };
 944
 945 /* The corresponding option definitions.  */
 946 extern const gdb::option::option_def set_backtrace_option_defs[2];
 947
 948 /* The values behind the global "set backtrace ..." settings.  */
 949 extern set_backtrace_options user_set_backtrace_options;
 950
 951 /* Get the number of calls to reinit_frame_cache.  */
 952
 953 unsigned int get_frame_cache_generation ();
 954
 955 /* Mark that the PC value is masked for the previous frame.  */
 956
 957 extern void set_frame_previous_pc_masked (struct frame_info *frame);
 958
 959 /* Get whether the PC value is masked for the given frame.  */
 960
 961 extern bool get_frame_pc_masked (const struct frame_info *frame);
 962
 963
 964 #endif /* !defined (FRAME_H)  */