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 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 #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.  E.g., this frame is the outermost
  89      (i.e., _start), and the stack hasn't been setup yet.  */
  90   FID_STACK_INVALID = 0,
  91
  92   /* Stack address is valid, and is found in the stack_addr field.  */
  93   FID_STACK_VALID = 1,
  94
  95   /* Sentinel frame.  */
  96   FID_STACK_SENTINEL = 2,
  97
  98   /* Stack address is unavailable.  I.e., there's a valid stack, but
  99      we don't know where it is (because memory or registers we'd
 100      compute it from were not collected).  */
 101   FID_STACK_UNAVAILABLE = -1
 102 };
 103
 104 /* The frame object.  */
 105
 106 struct frame_info;
 107
 108 /* The frame object's ID.  This provides a per-frame unique identifier
 109    that can be used to relocate a `struct frame_info' after a target
 110    resume or a frame cache destruct.  It of course assumes that the
 111    inferior hasn't unwound the stack past that frame.  */
 112
 113 struct frame_id
 114 {
 115   /* The frame's stack address.  This shall be constant through out
 116      the lifetime of a frame.  Note that this requirement applies to
 117      not just the function body, but also the prologue and (in theory
 118      at least) the epilogue.  Since that value needs to fall either on
 119      the boundary, or within the frame's address range, the frame's
 120      outer-most address (the inner-most address of the previous frame)
 121      is used.  Watch out for all the legacy targets that still use the
 122      function pointer register or stack pointer register.  They are
 123      wrong.
 124
 125      This field is valid only if frame_id.stack_status is
 126      FID_STACK_VALID.  It will be 0 for other
 127      FID_STACK_... statuses.  */
 128   CORE_ADDR stack_addr;
 129
 130   /* The frame's code address.  This shall be constant through out the
 131      lifetime of the frame.  While the PC (a.k.a. resume address)
 132      changes as the function is executed, this code address cannot.
 133      Typically, it is set to the address of the entry point of the
 134      frame's function (as returned by get_frame_func).
 135
 136      For inlined functions (INLINE_DEPTH != 0), this is the address of
 137      the first executed instruction in the block corresponding to the
 138      inlined function.
 139
 140      This field is valid only if code_addr_p is true.  Otherwise, this
 141      frame is considered to have a wildcard code address, i.e. one that
 142      matches every address value in frame comparisons.  */
 143   CORE_ADDR code_addr;
 144
 145   /* The frame's special address.  This shall be constant through out the
 146      lifetime of the frame.  This is used for architectures that may have
 147      frames that do not change the stack but are still distinct and have
 148      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 149      stack for registers).  This field is treated as unordered - i.e. will
 150      not be used in frame ordering comparisons.
 151
 152      This field is valid only if special_addr_p is true.  Otherwise, this
 153      frame is considered to have a wildcard special address, i.e. one that
 154      matches every address value in frame comparisons.  */
 155   CORE_ADDR special_addr;
 156
 157   /* Flags to indicate the above fields have valid contents.  */
 158   ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
 159   unsigned int code_addr_p : 1;
 160   unsigned int special_addr_p : 1;
 161
 162   /* It is non-zero for a frame made up by GDB without stack data
 163      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 164      Caller of inlined function will have it zero, each more inner called frame
 165      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 166   int artificial_depth;
 167 };
 168
 169 /* Save and restore the currently selected frame.  */
 170
 171 class scoped_restore_selected_frame
 172 {
 173 public:
 174   /* Save the currently selected frame.  */
 175   scoped_restore_selected_frame ();
 176
 177   /* Restore the currently selected frame.  */
 178   ~scoped_restore_selected_frame ();
 179
 180   DISABLE_COPY_AND_ASSIGN (scoped_restore_selected_frame);
 181
 182 private:
 183
 184   /* The ID of the previously selected frame.  */
 185   struct frame_id m_fid;
 186 };
 187
 188 /* Methods for constructing and comparing Frame IDs.  */
 189
 190 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 191 extern const struct frame_id null_frame_id;
 192
 193 /* Sentinel frame.  */
 194 extern const struct frame_id sentinel_frame_id;
 195
 196 /* This means "there is no frame ID, but there is a frame".  It should be
 197    replaced by best-effort frame IDs for the outermost frame, somehow.
 198    The implementation is only special_addr_p set.  */
 199 extern const struct frame_id outer_frame_id;
 200
 201 /* Flag to control debugging.  */
 202
 203 extern unsigned int frame_debug;
 204
 205 /* Construct a frame ID.  The first parameter is the frame's constant
 206    stack address (typically the outer-bound), and the second the
 207    frame's constant code address (typically the entry point).
 208    The special identifier address is set to indicate a wild card.  */
 209 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 210                                        CORE_ADDR code_addr);
 211
 212 /* Construct a special frame ID.  The first parameter is the frame's constant
 213    stack address (typically the outer-bound), the second is the
 214    frame's constant code address (typically the entry point),
 215    and the third parameter is the frame's special identifier address.  */
 216 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 217                                                CORE_ADDR code_addr,
 218                                                CORE_ADDR special_addr);
 219
 220 /* Construct a frame ID representing a frame where the stack address
 221    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 222    address (typically the entry point).  The special identifier
 223    address is set to indicate a wild card.  */
 224 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 225
 226 /* Construct a frame ID representing a frame where the stack address
 227    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 228    address (typically the entry point).  SPECIAL_ADDR is the special
 229    identifier address.  */
 230 extern struct frame_id
 231   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 232                                             CORE_ADDR special_addr);
 233
 234 /* Construct a wild card frame ID.  The parameter is the frame's constant
 235    stack address (typically the outer-bound).  The code address as well
 236    as the special identifier address are set to indicate wild cards.  */
 237 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 238
 239 /* Returns non-zero when L is a valid frame (a valid frame has a
 240    non-zero .base).  The outermost frame is valid even without an
 241    ID.  */
 242 extern int frame_id_p (struct frame_id l);
 243
 244 /* Returns non-zero when L is a valid frame representing a frame made up by GDB
 245    without stack data representation in inferior, such as INLINE_FRAME or
 246    TAILCALL_FRAME.  */
 247 extern int frame_id_artificial_p (struct frame_id l);
 248
 249 /* Returns non-zero when L and R identify the same frame, or, if
 250    either L or R have a zero .func, then the same frame base.  */
 251 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 252
 253 /* Write the internal representation of a frame ID on the specified
 254    stream.  */
 255 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 256
 257
 258 /* Frame types.  Some are real, some are signal trampolines, and some
 259    are completely artificial (dummy).  */
 260
 261 enum frame_type
 262 {
 263   /* A true stack frame, created by the target program during normal
 264      execution.  */
 265   NORMAL_FRAME,
 266   /* A fake frame, created by GDB when performing an inferior function
 267      call.  */
 268   DUMMY_FRAME,
 269   /* A frame representing an inlined function, associated with an
 270      upcoming (prev, outer, older) NORMAL_FRAME.  */
 271   INLINE_FRAME,
 272   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 273   TAILCALL_FRAME,
 274   /* In a signal handler, various OSs handle this in various ways.
 275      The main thing is that the frame may be far from normal.  */
 276   SIGTRAMP_FRAME,
 277   /* Fake frame representing a cross-architecture call.  */
 278   ARCH_FRAME,
 279   /* Sentinel or registers frame.  This frame obtains register values
 280      direct from the inferior's registers.  */
 281   SENTINEL_FRAME
 282 };
 283
 284 /* For every stopped thread, GDB tracks two frames: current and
 285    selected.  Current frame is the inner most frame of the selected
 286    thread.  Selected frame is the one being examined by the GDB
 287    CLI (selected using `up', `down', ...).  The frames are created
 288    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 289 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 290    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 291    selected frame.  At present GDB only tracks the selected frame of
 292    the current thread.  But be warned, that might change.  */
 293 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 294    and current frame can be active.  Switching threads causes gdb to
 295    discard all that cached frame information.  Ulgh!  Instead, current
 296    and selected frame should be bound to a thread.  */
 297
 298 /* On demand, create the inner most frame using information found in
 299    the inferior.  If the inner most frame can't be created, throw an
 300    error.  */
 301 extern struct frame_info *get_current_frame (void);
 302
 303 /* Does the current target interface have enough state to be able to
 304    query the current inferior for frame info, and is the inferior in a
 305    state where that is possible?  */
 306 extern int has_stack_frames (void);
 307
 308 /* Invalidates the frame cache (this function should have been called
 309    invalidate_cached_frames).
 310
 311    FIXME: cagney/2002-11-28: There should be two methods: one that
 312    reverts the thread's selected frame back to current frame (for when
 313    the inferior resumes) and one that does not (for when the user
 314    modifies the target invalidating the frame cache).  */
 315 extern void reinit_frame_cache (void);
 316
 317 /* On demand, create the selected frame and then return it.  If the
 318    selected frame can not be created, this function prints then throws
 319    an error.  When MESSAGE is non-NULL, use it for the error message,
 320    otherwize use a generic error message.  */
 321 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 322    frame, this function always returns the current (inner most) frame.
 323    It should instead, when a thread has previously had its frame
 324    selected (but not resumed) and the frame cache invalidated, find
 325    and then return that thread's previously selected frame.  */
 326 extern struct frame_info *get_selected_frame (const char *message);
 327
 328 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 329 extern struct frame_info *get_selected_frame_if_set (void);
 330
 331 /* Select a specific frame.  NULL, apparently implies re-select the
 332    inner most frame.  */
 333 extern void select_frame (struct frame_info *);
 334
 335 /* Given a FRAME, return the next (more inner, younger) or previous
 336    (more outer, older) frame.  */
 337 extern struct frame_info *get_prev_frame (struct frame_info *);
 338 extern struct frame_info *get_next_frame (struct frame_info *);
 339
 340 /* Like get_next_frame(), but allows return of the sentinel frame.  NULL
 341    is never returned.  */
 342 extern struct frame_info *get_next_frame_sentinel_okay (struct frame_info *);
 343
 344 /* Return a "struct frame_info" corresponding to the frame that called
 345    THIS_FRAME.  Returns NULL if there is no such frame.
 346
 347    Unlike get_prev_frame, this function always tries to unwind the
 348    frame.  */
 349 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 350
 351 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 352    is not found.  */
 353 extern struct frame_info *frame_find_by_id (struct frame_id id);
 354
 355 /* Given a frame's ID, find the previous frame's ID.  Returns null_frame_id
 356    if the frame is not found.  */
 357 extern struct frame_id get_prev_frame_id_by_id (struct frame_id id);
 358
 359 /* Base attributes of a frame: */
 360
 361 /* The frame's `resume' address.  Where the program will resume in
 362    this frame.
 363
 364    This replaced: frame->pc; */
 365 extern CORE_ADDR get_frame_pc (struct frame_info *);
 366
 367 /* Same as get_frame_pc, but return a boolean indication of whether
 368    the PC is actually available, instead of throwing an error.  */
 369
 370 extern int get_frame_pc_if_available (struct frame_info *frame,
 371                                       CORE_ADDR *pc);
 372
 373 /* An address (not necessarily aligned to an instruction boundary)
 374    that falls within THIS frame's code block.
 375
 376    When a function call is the last statement in a block, the return
 377    address for the call may land at the start of the next block.
 378    Similarly, if a no-return function call is the last statement in
 379    the function, the return address may end up pointing beyond the
 380    function, and possibly at the start of the next function.
 381
 382    These methods make an allowance for this.  For call frames, this
 383    function returns the frame's PC-1 which "should" be an address in
 384    the frame's block.  */
 385
 386 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 387
 388 /* Same as get_frame_address_in_block, but returns a boolean
 389    indication of whether the frame address is determinable (when the
 390    PC is unavailable, it will not be), instead of possibly throwing an
 391    error trying to read an unavailable PC.  */
 392
 393 extern int
 394   get_frame_address_in_block_if_available (struct 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 int get_frame_func_if_available (struct 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 int read_frame_register_unsigned (struct 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 int get_frame_register_bytes (struct 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 non-zero when the entire memory read
 666    succeeds, zero otherwize.  */
 667 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 668                                      CORE_ADDR addr, 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 int deprecated_frame_register_read (struct 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 int frame_unwinder_is (struct frame_info *fi,
 911                               const struct frame_unwind *unwinder);
 912
 913 /* Return the language of FRAME.  */
 914
 915 extern enum language get_frame_language (struct frame_info *frame);
 916
 917 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 918    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 919    chain.  */
 920
 921 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 922
 923 /* Return the first frame above FRAME or FRAME of which the code is
 924    writable.  */
 925
 926 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 927
 928 /* Data for the "set backtrace" settings.  */
 929
 930 struct set_backtrace_options
 931 {
 932   /* Flag to indicate whether backtraces should continue past
 933      main.  */
 934   bool backtrace_past_main = false;
 935
 936   /* Flag to indicate whether backtraces should continue past
 937      entry.  */
 938   bool backtrace_past_entry = false;
 939
 940   /* Upper bound on the number of backtrace levels.  Note this is not
 941      exposed as a command option, because "backtrace" and "frame
 942      apply" already have other means to set a frame count limit.  */
 943   unsigned int backtrace_limit = UINT_MAX;
 944 };
 945
 946 /* The corresponding option definitions.  */
 947 extern const gdb::option::option_def set_backtrace_option_defs[2];
 948
 949 /* The values behind the global "set backtrace ..." settings.  */
 950 extern set_backtrace_options user_set_backtrace_options;
 951
 952 /* Mark that the PC value is masked for the previous frame.  */
 953
 954 extern void set_frame_previous_pc_masked (struct frame_info *frame);
 955
 956 /* Get whether the PC value is masked for the given frame.  */
 957
 958 extern bool get_frame_pc_masked (const struct frame_info *frame);
 959
 960
 961 #endif /* !defined (FRAME_H)  */