gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2017 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (FRAME_H)
  21 #define FRAME_H 1
  22
  23 /* The following is the intended naming schema for frame functions.
  24    It isn't 100% consistent, but it is aproaching that.  Frame naming
  25    schema:
  26
  27    Prefixes:
  28
  29    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  30    equivalent to THIS->next->unwind->what)
  31
  32    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  33    frame.
  34
  35    frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
  36    real caller.  Any inlined functions in NEXT's stack frame are
  37    skipped.  Use these to ignore any potentially inlined functions,
  38    e.g. inlined into the first instruction of a library trampoline.
  39
  40    get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is
  41    inlined, skip to the containing stack frame.
  42
  43    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  44    invalidate the frame / regcache afterwards) (better name more
  45    strongly hinting at its unsafeness)
  46
  47    safe_....(): Safer version of various functions, doesn't throw an
  48    error (leave this for later?).  Returns non-zero / non-NULL if the
  49    request succeeds, zero / NULL otherwize.
  50
  51    Suffixes:
  52
  53    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  54
  55    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  56    alternative is *frame_unsigned_WHAT).
  57
  58    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  59
  60    What:
  61
  62    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  63    *memory.
  64
  65    /frame/_register* (frame, regnum [, buf]): extract/return register.
  66
  67    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  68    stack *address, ...
  69
  70    */
  71
  72 #include "language.h"
  73
  74 struct symtab_and_line;
  75 struct frame_unwind;
  76 struct frame_base;
  77 struct block;
  78 struct gdbarch;
  79 struct ui_file;
  80 struct ui_out;
  81
  82 /* Status of a given frame's stack.  */
  83
  84 enum frame_id_stack_status
  85 {
  86   /* Stack address is invalid.  E.g., this frame is the outermost
  87      (i.e., _start), and the stack hasn't been setup yet.  */
  88   FID_STACK_INVALID = 0,
  89
  90   /* Stack address is valid, and is found in the stack_addr field.  */
  91   FID_STACK_VALID = 1,
  92
  93   /* Sentinel frame.  */
  94   FID_STACK_SENTINEL = 2,
  95
  96   /* Stack address is unavailable.  I.e., there's a valid stack, but
  97      we don't know where it is (because memory or registers we'd
  98      compute it from were not collected).  */
  99   FID_STACK_UNAVAILABLE = -1
 100 };
 101
 102 /* The frame object.  */
 103
 104 struct frame_info;
 105
 106 /* The frame object's ID.  This provides a per-frame unique identifier
 107    that can be used to relocate a `struct frame_info' after a target
 108    resume or a frame cache destruct.  It of course assumes that the
 109    inferior hasn't unwound the stack past that frame.  */
 110
 111 struct frame_id
 112 {
 113   /* The frame's stack address.  This shall be constant through out
 114      the lifetime of a frame.  Note that this requirement applies to
 115      not just the function body, but also the prologue and (in theory
 116      at least) the epilogue.  Since that value needs to fall either on
 117      the boundary, or within the frame's address range, the frame's
 118      outer-most address (the inner-most address of the previous frame)
 119      is used.  Watch out for all the legacy targets that still use the
 120      function pointer register or stack pointer register.  They are
 121      wrong.
 122
 123      This field is valid only if frame_id.stack_status is
 124      FID_STACK_VALID.  It will be 0 for other
 125      FID_STACK_... statuses.  */
 126   CORE_ADDR stack_addr;
 127
 128   /* The frame's code address.  This shall be constant through out the
 129      lifetime of the frame.  While the PC (a.k.a. resume address)
 130      changes as the function is executed, this code address cannot.
 131      Typically, it is set to the address of the entry point of the
 132      frame's function (as returned by get_frame_func).
 133
 134      For inlined functions (INLINE_DEPTH != 0), this is the address of
 135      the first executed instruction in the block corresponding to the
 136      inlined function.
 137
 138      This field is valid only if code_addr_p is true.  Otherwise, this
 139      frame is considered to have a wildcard code address, i.e. one that
 140      matches every address value in frame comparisons.  */
 141   CORE_ADDR code_addr;
 142
 143   /* The frame's special address.  This shall be constant through out the
 144      lifetime of the frame.  This is used for architectures that may have
 145      frames that do not change the stack but are still distinct and have
 146      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 147      stack for registers).  This field is treated as unordered - i.e. will
 148      not be used in frame ordering comparisons.
 149
 150      This field is valid only if special_addr_p is true.  Otherwise, this
 151      frame is considered to have a wildcard special address, i.e. one that
 152      matches every address value in frame comparisons.  */
 153   CORE_ADDR special_addr;
 154
 155   /* Flags to indicate the above fields have valid contents.  */
 156   ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
 157   unsigned int code_addr_p : 1;
 158   unsigned int special_addr_p : 1;
 159
 160   /* It is non-zero for a frame made up by GDB without stack data
 161      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 162      Caller of inlined function will have it zero, each more inner called frame
 163      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 164   int artificial_depth;
 165 };
 166
 167 /* Methods for constructing and comparing Frame IDs.  */
 168
 169 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 170 extern const struct frame_id null_frame_id;
 171
 172 /* Sentinel frame.  */
 173 extern const struct frame_id sentinel_frame_id;
 174
 175 /* This means "there is no frame ID, but there is a frame".  It should be
 176    replaced by best-effort frame IDs for the outermost frame, somehow.
 177    The implementation is only special_addr_p set.  */
 178 extern const struct frame_id outer_frame_id;
 179
 180 /* Flag to control debugging.  */
 181
 182 extern unsigned int frame_debug;
 183
 184 /* Construct a frame ID.  The first parameter is the frame's constant
 185    stack address (typically the outer-bound), and the second the
 186    frame's constant code address (typically the entry point).
 187    The special identifier address is set to indicate a wild card.  */
 188 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 189                                        CORE_ADDR code_addr);
 190
 191 /* Construct a special frame ID.  The first parameter is the frame's constant
 192    stack address (typically the outer-bound), the second is the
 193    frame's constant code address (typically the entry point),
 194    and the third parameter is the frame's special identifier address.  */
 195 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 196                                                CORE_ADDR code_addr,
 197                                                CORE_ADDR special_addr);
 198
 199 /* Construct a frame ID representing a frame where the stack address
 200    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 201    address (typically the entry point).  The special identifier
 202    address is set to indicate a wild card.  */
 203 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 204
 205 /* Construct a frame ID representing a frame where the stack address
 206    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 207    address (typically the entry point).  SPECIAL_ADDR is the special
 208    identifier address.  */
 209 extern struct frame_id
 210   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 211                                             CORE_ADDR special_addr);
 212
 213 /* Construct a wild card frame ID.  The parameter is the frame's constant
 214    stack address (typically the outer-bound).  The code address as well
 215    as the special identifier address are set to indicate wild cards.  */
 216 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 217
 218 /* Returns non-zero when L is a valid frame (a valid frame has a
 219    non-zero .base).  The outermost frame is valid even without an
 220    ID.  */
 221 extern int frame_id_p (struct frame_id l);
 222
 223 /* Returns non-zero when L is a valid frame representing a frame made up by GDB
 224    without stack data representation in inferior, such as INLINE_FRAME or
 225    TAILCALL_FRAME.  */
 226 extern int frame_id_artificial_p (struct frame_id l);
 227
 228 /* Returns non-zero when L and R identify the same frame, or, if
 229    either L or R have a zero .func, then the same frame base.  */
 230 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 231
 232 /* Write the internal representation of a frame ID on the specified
 233    stream.  */
 234 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 235
 236
 237 /* Frame types.  Some are real, some are signal trampolines, and some
 238    are completely artificial (dummy).  */
 239
 240 enum frame_type
 241 {
 242   /* A true stack frame, created by the target program during normal
 243      execution.  */
 244   NORMAL_FRAME,
 245   /* A fake frame, created by GDB when performing an inferior function
 246      call.  */
 247   DUMMY_FRAME,
 248   /* A frame representing an inlined function, associated with an
 249      upcoming (prev, outer, older) NORMAL_FRAME.  */
 250   INLINE_FRAME,
 251   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 252   TAILCALL_FRAME,
 253   /* In a signal handler, various OSs handle this in various ways.
 254      The main thing is that the frame may be far from normal.  */
 255   SIGTRAMP_FRAME,
 256   /* Fake frame representing a cross-architecture call.  */
 257   ARCH_FRAME,
 258   /* Sentinel or registers frame.  This frame obtains register values
 259      direct from the inferior's registers.  */
 260   SENTINEL_FRAME
 261 };
 262
 263 /* For every stopped thread, GDB tracks two frames: current and
 264    selected.  Current frame is the inner most frame of the selected
 265    thread.  Selected frame is the one being examined by the GDB
 266    CLI (selected using `up', `down', ...).  The frames are created
 267    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 268 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 269    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 270    selected frame.  At present GDB only tracks the selected frame of
 271    the current thread.  But be warned, that might change.  */
 272 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 273    and current frame can be active.  Switching threads causes gdb to
 274    discard all that cached frame information.  Ulgh!  Instead, current
 275    and selected frame should be bound to a thread.  */
 276
 277 /* On demand, create the inner most frame using information found in
 278    the inferior.  If the inner most frame can't be created, throw an
 279    error.  */
 280 extern struct frame_info *get_current_frame (void);
 281
 282 /* Does the current target interface have enough state to be able to
 283    query the current inferior for frame info, and is the inferior in a
 284    state where that is possible?  */
 285 extern int has_stack_frames (void);
 286
 287 /* Invalidates the frame cache (this function should have been called
 288    invalidate_cached_frames).
 289
 290    FIXME: cagney/2002-11-28: There should be two methods: one that
 291    reverts the thread's selected frame back to current frame (for when
 292    the inferior resumes) and one that does not (for when the user
 293    modifies the target invalidating the frame cache).  */
 294 extern void reinit_frame_cache (void);
 295
 296 /* On demand, create the selected frame and then return it.  If the
 297    selected frame can not be created, this function prints then throws
 298    an error.  When MESSAGE is non-NULL, use it for the error message,
 299    otherwize use a generic error message.  */
 300 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 301    frame, this function always returns the current (inner most) frame.
 302    It should instead, when a thread has previously had its frame
 303    selected (but not resumed) and the frame cache invalidated, find
 304    and then return that thread's previously selected frame.  */
 305 extern struct frame_info *get_selected_frame (const char *message);
 306
 307 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 308 extern struct frame_info *get_selected_frame_if_set (void);
 309
 310 /* Select a specific frame.  NULL, apparently implies re-select the
 311    inner most frame.  */
 312 extern void select_frame (struct frame_info *);
 313
 314 /* Given a FRAME, return the next (more inner, younger) or previous
 315    (more outer, older) frame.  */
 316 extern struct frame_info *get_prev_frame (struct frame_info *);
 317 extern struct frame_info *get_next_frame (struct frame_info *);
 318
 319 /* Like get_next_frame(), but allows return of the sentinel frame.  NULL
 320    is never returned.  */
 321 extern struct frame_info *get_next_frame_sentinel_okay (struct frame_info *);
 322
 323 /* Return a "struct frame_info" corresponding to the frame that called
 324    THIS_FRAME.  Returns NULL if there is no such frame.
 325
 326    Unlike get_prev_frame, this function always tries to unwind the
 327    frame.  */
 328 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 329
 330 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 331    is not found.  */
 332 extern struct frame_info *frame_find_by_id (struct frame_id id);
 333
 334 /* Given a frame's ID, find the previous frame's ID.  Returns null_frame_id
 335    if the frame is not found.  */
 336 extern struct frame_id get_prev_frame_id_by_id (struct frame_id id);
 337
 338 /* Base attributes of a frame: */
 339
 340 /* The frame's `resume' address.  Where the program will resume in
 341    this frame.
 342
 343    This replaced: frame->pc; */
 344 extern CORE_ADDR get_frame_pc (struct frame_info *);
 345
 346 /* Same as get_frame_pc, but return a boolean indication of whether
 347    the PC is actually available, instead of throwing an error.  */
 348
 349 extern int get_frame_pc_if_available (struct frame_info *frame,
 350                                       CORE_ADDR *pc);
 351
 352 /* An address (not necessarily aligned to an instruction boundary)
 353    that falls within THIS frame's code block.
 354
 355    When a function call is the last statement in a block, the return
 356    address for the call may land at the start of the next block.
 357    Similarly, if a no-return function call is the last statement in
 358    the function, the return address may end up pointing beyond the
 359    function, and possibly at the start of the next function.
 360
 361    These methods make an allowance for this.  For call frames, this
 362    function returns the frame's PC-1 which "should" be an address in
 363    the frame's block.  */
 364
 365 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 366
 367 /* Same as get_frame_address_in_block, but returns a boolean
 368    indication of whether the frame address is determinable (when the
 369    PC is unavailable, it will not be), instead of possibly throwing an
 370    error trying to read an unavailable PC.  */
 371
 372 extern int
 373   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 374                                            CORE_ADDR *pc);
 375
 376 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 377    known as top-of-stack.  */
 378
 379 extern CORE_ADDR get_frame_sp (struct frame_info *);
 380
 381 /* Following on from the `resume' address.  Return the entry point
 382    address of the function containing that resume address, or zero if
 383    that function isn't known.  */
 384 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 385
 386 /* Same as get_frame_func, but returns a boolean indication of whether
 387    the frame function is determinable (when the PC is unavailable, it
 388    will not be), instead of possibly throwing an error trying to read
 389    an unavailable PC.  */
 390
 391 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 392
 393 /* Closely related to the resume address, various symbol table
 394    attributes that are determined by the PC.  Note that for a normal
 395    frame, the PC refers to the resume address after the return, and
 396    not the call instruction.  In such a case, the address is adjusted
 397    so that it (approximately) identifies the call site (and not the
 398    return site).
 399
 400    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 401    computed value.  Working on the assumption that the bottle-neck is
 402    in the single step code, and that code causes the frame cache to be
 403    constantly flushed, caching things in a frame is probably of little
 404    benefit.  As they say `show us the numbers'.
 405
 406    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 407    find_frame_block(), find_frame_partial_function(),
 408    find_frame_symtab(), find_frame_function().  Each will need to be
 409    carefully considered to determine if the real intent was for it to
 410    apply to the PC or the adjusted PC.  */
 411 extern symtab_and_line find_frame_sal (frame_info *frame);
 412
 413 /* Set the current source and line to the location given by frame
 414    FRAME, if possible.  */
 415
 416 void set_current_sal_from_frame (struct frame_info *);
 417
 418 /* Return the frame base (what ever that is) (DEPRECATED).
 419
 420    Old code was trying to use this single method for two conflicting
 421    purposes.  Such code needs to be updated to use either of:
 422
 423    get_frame_id: A low level frame unique identifier, that consists of
 424    both a stack and a function address, that can be used to uniquely
 425    identify a frame.  This value is determined by the frame's
 426    low-level unwinder, the stack part [typically] being the
 427    top-of-stack of the previous frame, and the function part being the
 428    function's start address.  Since the correct identification of a
 429    frameless function requires both a stack and function address,
 430    the old get_frame_base method was not sufficient.
 431
 432    get_frame_base_address: get_frame_locals_address:
 433    get_frame_args_address: A set of high-level debug-info dependant
 434    addresses that fall within the frame.  These addresses almost
 435    certainly will not match the stack address part of a frame ID (as
 436    returned by get_frame_base).
 437
 438    This replaced: frame->frame; */
 439
 440 extern CORE_ADDR get_frame_base (struct frame_info *);
 441
 442 /* Return the per-frame unique identifer.  Can be used to relocate a
 443    frame after a frame cache flush (and other similar operations).  If
 444    FI is NULL, return the null_frame_id.
 445
 446    NOTE: kettenis/20040508: These functions return a structure.  On
 447    platforms where structures are returned in static storage (vax,
 448    m68k), this may trigger compiler bugs in code like:
 449
 450    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 451
 452    where the return value from the first get_frame_id (l) gets
 453    overwritten by the second get_frame_id (r).  Please avoid writing
 454    code like this.  Use code like:
 455
 456    struct frame_id id = get_frame_id (l);
 457    if (frame_id_eq (id, get_frame_id (r)))
 458
 459    instead, since that avoids the bug.  */
 460 extern struct frame_id get_frame_id (struct frame_info *fi);
 461 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 462 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 463
 464 /* Assuming that a frame is `normal', return its base-address, or 0 if
 465    the information isn't available.  NOTE: This address is really only
 466    meaningful to the frame's high-level debug info.  */
 467 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 468
 469 /* Assuming that a frame is `normal', return the base-address of the
 470    local variables, or 0 if the information isn't available.  NOTE:
 471    This address is really only meaningful to the frame's high-level
 472    debug info.  Typically, the argument and locals share a single
 473    base-address.  */
 474 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 475
 476 /* Assuming that a frame is `normal', return the base-address of the
 477    parameter list, or 0 if that information isn't available.  NOTE:
 478    This address is really only meaningful to the frame's high-level
 479    debug info.  Typically, the argument and locals share a single
 480    base-address.  */
 481 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 482
 483 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 484    for an invalid frame).  */
 485 extern int frame_relative_level (struct frame_info *fi);
 486
 487 /* Return the frame's type.  */
 488
 489 extern enum frame_type get_frame_type (struct frame_info *);
 490
 491 /* Return the frame's program space.  */
 492 extern struct program_space *get_frame_program_space (struct frame_info *);
 493
 494 /* Unwind THIS frame's program space from the NEXT frame.  */
 495 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 496
 497 /* Return the frame's address space.  */
 498 extern struct address_space *get_frame_address_space (struct frame_info *);
 499
 500 /* For frames where we can not unwind further, describe why.  */
 501
 502 enum unwind_stop_reason
 503   {
 504 #define SET(name, description) name,
 505 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 506 #define LAST_ENTRY(name) UNWIND_LAST = name,
 507 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 508
 509 #include "unwind_stop_reasons.def"
 510 #undef SET
 511 #undef FIRST_ENTRY
 512 #undef LAST_ENTRY
 513 #undef FIRST_ERROR
 514   };
 515
 516 /* Return the reason why we can't unwind past this frame.  */
 517
 518 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 519
 520 /* Translate a reason code to an informative string.  This converts the
 521    generic stop reason codes into a generic string describing the code.
 522    For a possibly frame specific string explaining the stop reason, use
 523    FRAME_STOP_REASON_STRING instead.  */
 524
 525 const char *unwind_stop_reason_to_string (enum unwind_stop_reason);
 526
 527 /* Return a possibly frame specific string explaining why the unwind
 528    stopped here.  E.g., if unwinding tripped on a memory error, this
 529    will return the error description string, which includes the address
 530    that we failed to access.  If there's no specific reason stored for
 531    a frame then a generic reason string will be returned.
 532
 533    Should only be called for frames that don't have a previous frame.  */
 534
 535 const char *frame_stop_reason_string (struct frame_info *);
 536
 537 /* Unwind the stack frame so that the value of REGNUM, in the previous
 538    (up, older) frame is returned.  If VALUEP is NULL, don't
 539    fetch/compute the value.  Instead just return the location of the
 540    value.  */
 541 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 542                                    int *optimizedp, int *unavailablep,
 543                                    enum lval_type *lvalp,
 544                                    CORE_ADDR *addrp, int *realnump,
 545                                    gdb_byte *valuep);
 546
 547 /* Fetch a register from this, or unwind a register from the next
 548    frame.  Note that the get_frame methods are wrappers to
 549    frame->next->unwind.  They all [potentially] throw an error if the
 550    fetch fails.  The value methods never return NULL, but usually
 551    do return a lazy value.  */
 552
 553 extern void frame_unwind_register (struct frame_info *frame,
 554                                    int regnum, gdb_byte *buf);
 555 extern void get_frame_register (struct frame_info *frame,
 556                                 int regnum, gdb_byte *buf);
 557
 558 struct value *frame_unwind_register_value (struct frame_info *frame,
 559                                            int regnum);
 560 struct value *get_frame_register_value (struct frame_info *frame,
 561                                         int regnum);
 562
 563 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 564                                              int regnum);
 565 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 566                                           int regnum);
 567 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 568                                                int regnum);
 569 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 570                                              int regnum);
 571
 572 /* Read a register from this, or unwind a register from the next
 573    frame.  Note that the read_frame methods are wrappers to
 574    get_frame_register_value, that do not throw if the result is
 575    optimized out or unavailable.  */
 576
 577 extern int read_frame_register_unsigned (struct frame_info *frame,
 578                                          int regnum, ULONGEST *val);
 579
 580 /* Get the value of the register that belongs to this FRAME.  This
 581    function is a wrapper to the call sequence ``frame_register_unwind
 582    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 583    VALUEP is NULL, the registers value is not fetched/computed.  */
 584
 585 extern void frame_register (struct frame_info *frame, int regnum,
 586                             int *optimizedp, int *unavailablep,
 587                             enum lval_type *lvalp,
 588                             CORE_ADDR *addrp, int *realnump,
 589                             gdb_byte *valuep);
 590
 591 /* The reverse.  Store a register value relative to the specified
 592    frame.  Note: this call makes the frame's state undefined.  The
 593    register and frame caches must be flushed.  */
 594 extern void put_frame_register (struct frame_info *frame, int regnum,
 595                                 const gdb_byte *buf);
 596
 597 /* Read LEN bytes from one or multiple registers starting with REGNUM
 598    in frame FRAME, starting at OFFSET, into BUF.  If the register
 599    contents are optimized out or unavailable, set *OPTIMIZEDP,
 600    *UNAVAILABLEP accordingly.  */
 601 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 602                                      CORE_ADDR offset, int len,
 603                                      gdb_byte *myaddr,
 604                                      int *optimizedp, int *unavailablep);
 605
 606 /* Write LEN bytes to one or multiple registers starting with REGNUM
 607    in frame FRAME, starting at OFFSET, into BUF.  */
 608 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 609                                       CORE_ADDR offset, int len,
 610                                       const gdb_byte *myaddr);
 611
 612 /* Unwind the PC.  Strictly speaking return the resume address of the
 613    calling frame.  For GDB, `pc' is the resume address and not a
 614    specific register.  */
 615
 616 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 617
 618 /* Discard the specified frame.  Restoring the registers to the state
 619    of the caller.  */
 620 extern void frame_pop (struct frame_info *frame);
 621
 622 /* Return memory from the specified frame.  A frame knows its thread /
 623    LWP and hence can find its way down to a target.  The assumption
 624    here is that the current and previous frame share a common address
 625    space.
 626
 627    If the memory read fails, these methods throw an error.
 628
 629    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 630    methods?  That isn't clear.  Can code, for instance, assume that
 631    this and the previous frame's memory or architecture are identical?
 632    If architecture / memory changes are always separated by special
 633    adaptor frames this should be ok.  */
 634
 635 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 636                               gdb_byte *buf, int len);
 637 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 638                                         CORE_ADDR memaddr, int len);
 639 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 640                                            CORE_ADDR memaddr, int len);
 641
 642 /* Same as above, but return non-zero when the entire memory read
 643    succeeds, zero otherwize.  */
 644 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 645                                      CORE_ADDR addr, gdb_byte *buf, int len);
 646
 647 /* Return this frame's architecture.  */
 648 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 649
 650 /* Return the previous frame's architecture.  */
 651 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 652
 653 /* Return the previous frame's architecture, skipping inline functions.  */
 654 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 655
 656
 657 /* Values for the source flag to be used in print_frame_info_base().  */
 658 enum print_what
 659   {
 660     /* Print only the source line, like in stepi.  */
 661     SRC_LINE = -1,
 662     /* Print only the location, i.e. level, address (sometimes)
 663        function, args, file, line, line num.  */
 664     LOCATION,
 665     /* Print both of the above.  */
 666     SRC_AND_LOC,
 667     /* Print location only, but always include the address.  */
 668     LOC_AND_ADDRESS
 669   };
 670
 671 /* Allocate zero initialized memory from the frame cache obstack.
 672    Appendices to the frame info (such as the unwind cache) should
 673    allocate memory using this method.  */
 674
 675 extern void *frame_obstack_zalloc (unsigned long size);
 676 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 677   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 678 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 679   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 680
 681 /* Create a regcache, and copy the frame's registers into it.  */
 682 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 683
 684 extern const struct block *get_frame_block (struct frame_info *,
 685                                             CORE_ADDR *addr_in_block);
 686
 687 /* Return the `struct block' that belongs to the selected thread's
 688    selected frame.  If the inferior has no state, return NULL.
 689
 690    NOTE: cagney/2002-11-29:
 691
 692    No state?  Does the inferior have any execution state (a core file
 693    does, an executable does not).  At present the code tests
 694    `target_has_stack' but I'm left wondering if it should test
 695    `target_has_registers' or, even, a merged target_has_state.
 696
 697    Should it look at the most recently specified SAL?  If the target
 698    has no state, should this function try to extract a block from the
 699    most recently selected SAL?  That way `list foo' would give it some
 700    sort of reference point.  Then again, perhaps that would confuse
 701    things.
 702
 703    Calls to this function can be broken down into two categories: Code
 704    that uses the selected block as an additional, but optional, data
 705    point; Code that uses the selected block as a prop, when it should
 706    have the relevant frame/block/pc explicitly passed in.
 707
 708    The latter can be eliminated by correctly parameterizing the code,
 709    the former though is more interesting.  Per the "address" command,
 710    it occurs in the CLI code and makes it possible for commands to
 711    work, even when the inferior has no state.  */
 712
 713 extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 714
 715 extern struct symbol *get_frame_function (struct frame_info *);
 716
 717 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 718
 719 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 720
 721 /* Wrapper over print_stack_frame modifying current_uiout with UIOUT for
 722    the function call.  */
 723
 724 extern void print_stack_frame_to_uiout (struct ui_out *uiout,
 725                                         struct frame_info *, int print_level,
 726                                         enum print_what print_what,
 727                                         int set_current_sal);
 728
 729 extern void print_stack_frame (struct frame_info *, int print_level,
 730                                enum print_what print_what,
 731                                int set_current_sal);
 732
 733 extern void print_frame_info (struct frame_info *, int print_level,
 734                               enum print_what print_what, int args,
 735                               int set_current_sal);
 736
 737 extern struct frame_info *block_innermost_frame (const struct block *);
 738
 739 extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
 740                                 gdb_byte *buf);
 741
 742 /* From stack.c.  */
 743
 744 extern const char print_entry_values_no[];
 745 extern const char print_entry_values_only[];
 746 extern const char print_entry_values_preferred[];
 747 extern const char print_entry_values_if_needed[];
 748 extern const char print_entry_values_both[];
 749 extern const char print_entry_values_compact[];
 750 extern const char print_entry_values_default[];
 751 extern const char *print_entry_values;
 752
 753 /* Inferior function parameter value read in from a frame.  */
 754
 755 struct frame_arg
 756 {
 757   /* Symbol for this parameter used for example for its name.  */
 758   struct symbol *sym;
 759
 760   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 761      ERROR are NULL this parameter's value should not be printed.  */
 762   struct value *val;
 763
 764   /* String containing the error message, it is more usually NULL indicating no
 765      error occured reading this parameter.  */
 766   char *error;
 767
 768   /* One of the print_entry_values_* entries as appropriate specifically for
 769      this frame_arg.  It will be different from print_entry_values.  With
 770      print_entry_values_no this frame_arg should be printed as a normal
 771      parameter.  print_entry_values_only says it should be printed as entry
 772      value parameter.  print_entry_values_compact says it should be printed as
 773      both as a normal parameter and entry values parameter having the same
 774      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 775      (in such case print_entry_values_no and print_entry_values_only is used
 776      for each parameter kind specifically.  */
 777   const char *entry_kind;
 778 };
 779
 780 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 781                             struct frame_arg *argp,
 782                             struct frame_arg *entryargp);
 783 extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
 784                               struct frame_arg *argp);
 785
 786 extern void info_args_command (char *, int);
 787
 788 extern void info_locals_command (char *, int);
 789
 790 extern void return_command (char *, int);
 791
 792 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 793    Return a cleanup which should be called if unwinding fails, and
 794    discarded if it succeeds.  */
 795
 796 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 797                                            const struct frame_unwind *unwind);
 798
 799 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 800
 801    You might think that calls to this function can simply be replaced by a
 802    call to get_selected_frame().
 803
 804    Unfortunately, it isn't that easy.
 805
 806    The relevant code needs to be audited to determine if it is
 807    possible (or practical) to instead pass the applicable frame in as a
 808    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 809    the deprecated_selected_frame global, while its replacement,
 810    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 811    The only real exceptions occur at the edge (in the CLI code) where
 812    user commands need to pick up the selected frame before proceeding.
 813
 814    There are also some functions called with a NULL frame meaning either "the
 815    program is not running" or "use the selected frame".
 816
 817    This is important.  GDB is trying to stamp out the hack:
 818
 819    saved_frame = deprecated_safe_get_selected_frame ();
 820    select_frame (...);
 821    hack_using_global_selected_frame ();
 822    select_frame (saved_frame);
 823
 824    Take care!
 825
 826    This function calls get_selected_frame if the inferior should have a
 827    frame, or returns NULL otherwise.  */
 828
 829 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 830
 831 /* Create a frame using the specified BASE and PC.  */
 832
 833 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 834
 835 #if GDB_SELF_TEST
 836
 837 /* Create a frame for unit test.  Its next frame is sentinel frame,
 838    created from REGCACHE.  */
 839
 840 extern struct frame_info *create_test_frame (struct regcache *regcache);
 841 #endif
 842
 843 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 844    otherwise.  */
 845
 846 extern int frame_unwinder_is (struct frame_info *fi,
 847                               const struct frame_unwind *unwinder);
 848
 849 /* Return the language of FRAME.  */
 850
 851 extern enum language get_frame_language (struct frame_info *frame);
 852
 853 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 854    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 855    chain.  */
 856
 857 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 858
 859 /* Return the first frame above FRAME or FRAME of which the code is
 860    writable.  */
 861
 862 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 863
 864 #endif /* !defined (FRAME_H)  */