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