gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,
   4    1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007
   5    Free Software Foundation, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22    Boston, MA 02110-1301, USA.  */
  23
  24 #if !defined (FRAME_H)
  25 #define FRAME_H 1
  26
  27 /* The following is the intended naming schema for frame functions.
  28    It isn't 100% consistent, but it is aproaching that.  Frame naming
  29    schema:
  30
  31    Prefixes:
  32
  33    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  34    equivalent to THIS->next->unwind->what)
  35
  36    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  37    frame.
  38
  39    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  40    invalidate the frame / regcache afterwards) (better name more
  41    strongly hinting at its unsafeness)
  42
  43    safe_....(): Safer version of various functions, doesn't throw an
  44    error (leave this for later?).  Returns non-zero / non-NULL if the
  45    request succeeds, zero / NULL otherwize.
  46
  47    Suffixes:
  48
  49    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  50
  51    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  52    alternative is *frame_unsigned_WHAT).
  53
  54    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  55
  56    What:
  57
  58    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  59    *memory.
  60
  61    /frame/_register* (frame, regnum [, buf]): extract/return register.
  62
  63    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  64    stack *address, ...
  65
  66    */
  67
  68 struct symtab_and_line;
  69 struct frame_unwind;
  70 struct frame_base;
  71 struct block;
  72 struct gdbarch;
  73 struct ui_file;
  74
  75 /* The frame object.  */
  76
  77 struct frame_info;
  78
  79 /* The frame object's ID.  This provides a per-frame unique identifier
  80    that can be used to relocate a `struct frame_info' after a target
  81    resume or a frame cache destruct.  It of course assumes that the
  82    inferior hasn't unwound the stack past that frame.  */
  83
  84 struct frame_id
  85 {
  86   /* The frame's stack address.  This shall be constant through out
  87      the lifetime of a frame.  Note that this requirement applies to
  88      not just the function body, but also the prologue and (in theory
  89      at least) the epilogue.  Since that value needs to fall either on
  90      the boundary, or within the frame's address range, the frame's
  91      outer-most address (the inner-most address of the previous frame)
  92      is used.  Watch out for all the legacy targets that still use the
  93      function pointer register or stack pointer register.  They are
  94      wrong.
  95
  96      This field is valid only if stack_addr_p is true.  Otherwise, this
  97      frame represents the null frame.  */
  98   CORE_ADDR stack_addr;
  99
 100   /* The frame's code address.  This shall be constant through out the
 101      lifetime of the frame.  While the PC (a.k.a. resume address)
 102      changes as the function is executed, this code address cannot.
 103      Typically, it is set to the address of the entry point of the
 104      frame's function (as returned by frame_func_unwind().
 105
 106      This field is valid only if code_addr_p is true.  Otherwise, this
 107      frame is considered to have a wildcard code address, i.e. one that
 108      matches every address value in frame comparisons.  */
 109   CORE_ADDR code_addr;
 110
 111   /* The frame's special address.  This shall be constant through out the
 112      lifetime of the frame.  This is used for architectures that may have
 113      frames that do not change the stack but are still distinct and have
 114      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 115      stack for registers).  This field is treated as unordered - i.e. will
 116      not be used in frame ordering comparisons such as frame_id_inner().
 117
 118      This field is valid only if special_addr_p is true.  Otherwise, this
 119      frame is considered to have a wildcard special address, i.e. one that
 120      matches every address value in frame comparisons.  */
 121   CORE_ADDR special_addr;
 122
 123   /* Flags to indicate the above fields have valid contents.  */
 124   unsigned int stack_addr_p : 1;
 125   unsigned int code_addr_p : 1;
 126   unsigned int special_addr_p : 1;
 127 };
 128
 129 /* Methods for constructing and comparing Frame IDs.
 130
 131    NOTE: Given stackless functions A and B, where A calls B (and hence
 132    B is inner-to A).  The relationships: !eq(A,B); !eq(B,A);
 133    !inner(A,B); !inner(B,A); all hold.
 134
 135    This is because, while B is inner-to A, B is not strictly inner-to A.
 136    Being stackless, they have an identical .stack_addr value, and differ
 137    only by their unordered .code_addr and/or .special_addr values.
 138
 139    Because frame_id_inner is only used as a safety net (e.g.,
 140    detect a corrupt stack) the lack of strictness is not a problem.
 141    Code needing to determine an exact relationship between two frames
 142    must instead use frame_id_eq and frame_id_unwind.  For instance,
 143    in the above, to determine that A stepped-into B, the equation
 144    "A.id != B.id && A.id == id_unwind (B)" can be used.  */
 145
 146 /* For convenience.  All fields are zero.  */
 147 extern const struct frame_id null_frame_id;
 148
 149 /* Construct a frame ID.  The first parameter is the frame's constant
 150    stack address (typically the outer-bound), and the second the
 151    frame's constant code address (typically the entry point).
 152    The special identifier address is set to indicate a wild card.  */
 153 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 154                                        CORE_ADDR code_addr);
 155
 156 /* Construct a special frame ID.  The first parameter is the frame's constant
 157    stack address (typically the outer-bound), the second is the
 158    frame's constant code address (typically the entry point),
 159    and the third parameter is the frame's special identifier address. */
 160 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 161                                                CORE_ADDR code_addr,
 162                                                CORE_ADDR special_addr);
 163
 164 /* Construct a wild card frame ID.  The parameter is the frame's constant
 165    stack address (typically the outer-bound).  The code address as well
 166    as the special identifier address are set to indicate wild cards.  */
 167 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 168
 169 /* Returns non-zero when L is a valid frame (a valid frame has a
 170    non-zero .base).  */
 171 extern int frame_id_p (struct frame_id l);
 172
 173 /* Returns non-zero when L and R identify the same frame, or, if
 174    either L or R have a zero .func, then the same frame base.  */
 175 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 176
 177 /* Returns non-zero when L is strictly inner-than R (they have
 178    different frame .bases).  Neither L, nor R can be `null'.  See note
 179    above about frameless functions.  */
 180 extern int frame_id_inner (struct frame_id l, struct frame_id r);
 181
 182 /* Write the internal representation of a frame ID on the specified
 183    stream.  */
 184 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 185
 186
 187 /* Frame types.  Some are real, some are signal trampolines, and some
 188    are completely artificial (dummy).  */
 189
 190 enum frame_type
 191 {
 192   /* A true stack frame, created by the target program during normal
 193      execution.  */
 194   NORMAL_FRAME,
 195   /* A fake frame, created by GDB when performing an inferior function
 196      call.  */
 197   DUMMY_FRAME,
 198   /* In a signal handler, various OSs handle this in various ways.
 199      The main thing is that the frame may be far from normal.  */
 200   SIGTRAMP_FRAME,
 201   /* Sentinel or registers frame.  This frame obtains register values
 202      direct from the inferior's registers.  */
 203   SENTINEL_FRAME
 204 };
 205
 206 /* For every stopped thread, GDB tracks two frames: current and
 207    selected.  Current frame is the inner most frame of the selected
 208    thread.  Selected frame is the one being examined by the the GDB
 209    CLI (selected using `up', `down', ...).  The frames are created
 210    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 211 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 212    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 213    selected frame.  At present GDB only tracks the selected frame of
 214    the current thread.  But be warned, that might change.  */
 215 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 216    and current frame can be active.  Switching threads causes gdb to
 217    discard all that cached frame information.  Ulgh!  Instead, current
 218    and selected frame should be bound to a thread.  */
 219
 220 /* On demand, create the inner most frame using information found in
 221    the inferior.  If the inner most frame can't be created, throw an
 222    error.  */
 223 extern struct frame_info *get_current_frame (void);
 224
 225 /* Invalidates the frame cache (this function should have been called
 226    invalidate_cached_frames).
 227
 228    FIXME: cagney/2002-11-28: The only difference between
 229    flush_cached_frames() and reinit_frame_cache() is that the latter
 230    explicitly sets the selected frame back to the current frame -- there
 231    isn't any real difference (except that one delays the selection of
 232    a new frame).  Code can instead simply rely on get_selected_frame()
 233    to reinit the selected frame as needed.  As for invalidating the
 234    cache, there should be two methods: one that reverts the thread's
 235    selected frame back to current frame (for when the inferior
 236    resumes) and one that does not (for when the user modifies the
 237    target invalidating the frame cache).  */
 238 extern void flush_cached_frames (void);
 239 extern void reinit_frame_cache (void);
 240
 241 /* On demand, create the selected frame and then return it.  If the
 242    selected frame can not be created, this function prints then throws
 243    an error.  When MESSAGE is non-NULL, use it for the error message,
 244    otherwize use a generic error message.  */
 245 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 246    frame, this function always returns the current (inner most) frame.
 247    It should instead, when a thread has previously had its frame
 248    selected (but not resumed) and the frame cache invalidated, find
 249    and then return that thread's previously selected frame.  */
 250 extern struct frame_info *get_selected_frame (const char *message);
 251
 252 /* Select a specific frame.  NULL, apparently implies re-select the
 253    inner most frame.  */
 254 extern void select_frame (struct frame_info *);
 255
 256 /* Given a FRAME, return the next (more inner, younger) or previous
 257    (more outer, older) frame.  */
 258 extern struct frame_info *get_prev_frame (struct frame_info *);
 259 extern struct frame_info *get_next_frame (struct frame_info *);
 260
 261 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 262    is not found.  */
 263 extern struct frame_info *frame_find_by_id (struct frame_id id);
 264
 265 /* Base attributes of a frame: */
 266
 267 /* The frame's `resume' address.  Where the program will resume in
 268    this frame.
 269
 270    This replaced: frame->pc; */
 271 extern CORE_ADDR get_frame_pc (struct frame_info *);
 272
 273 /* An address (not necessarily aligned to an instruction boundary)
 274    that falls within THIS frame's code block.
 275
 276    When a function call is the last statement in a block, the return
 277    address for the call may land at the start of the next block.
 278    Similarly, if a no-return function call is the last statement in
 279    the function, the return address may end up pointing beyond the
 280    function, and possibly at the start of the next function.
 281
 282    These methods make an allowance for this.  For call frames, this
 283    function returns the frame's PC-1 which "should" be an address in
 284    the frame's block.  */
 285
 286 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 287
 288 /* Similar to get_frame_address_in_block, find an address in the
 289    block which logically called NEXT_FRAME, assuming it is a THIS_TYPE
 290    frame.  */
 291
 292 extern CORE_ADDR frame_unwind_address_in_block (struct frame_info *next_frame,
 293                                                 enum frame_type this_type);
 294
 295 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 296    known as top-of-stack.  */
 297
 298 extern CORE_ADDR get_frame_sp (struct frame_info *);
 299 extern CORE_ADDR frame_sp_unwind (struct frame_info *);
 300
 301
 302 /* Following on from the `resume' address.  Return the entry point
 303    address of the function containing that resume address, or zero if
 304    that function isn't known.  */
 305 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 306
 307 /* Similar to get_frame_func, find the start of the function which
 308    logically called NEXT_FRAME, assuming it is a THIS_TYPE frame.  */
 309 extern CORE_ADDR frame_func_unwind (struct frame_info *next_frame,
 310                                     enum frame_type this_type);
 311
 312 /* Closely related to the resume address, various symbol table
 313    attributes that are determined by the PC.  Note that for a normal
 314    frame, the PC refers to the resume address after the return, and
 315    not the call instruction.  In such a case, the address is adjusted
 316    so that it (approximately) identifies the call site (and not the
 317    return site).
 318
 319    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 320    computed value.  Working on the assumption that the bottle-neck is
 321    in the single step code, and that code causes the frame cache to be
 322    constantly flushed, caching things in a frame is probably of little
 323    benefit.  As they say `show us the numbers'.
 324
 325    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 326    find_frame_block(), find_frame_partial_function(),
 327    find_frame_symtab(), find_frame_function().  Each will need to be
 328    carefully considered to determine if the real intent was for it to
 329    apply to the PC or the adjusted PC.  */
 330 extern void find_frame_sal (struct frame_info *frame,
 331                             struct symtab_and_line *sal);
 332
 333 /* Set the current source and line to the location given by frame
 334    FRAME, if possible.  When CENTER is true, adjust so the relevant
 335    line is in the center of the next 'list'.  */
 336
 337 void set_current_sal_from_frame (struct frame_info *, int);
 338
 339 /* Return the frame base (what ever that is) (DEPRECATED).
 340
 341    Old code was trying to use this single method for two conflicting
 342    purposes.  Such code needs to be updated to use either of:
 343
 344    get_frame_id: A low level frame unique identifier, that consists of
 345    both a stack and a function address, that can be used to uniquely
 346    identify a frame.  This value is determined by the frame's
 347    low-level unwinder, the stack part [typically] being the
 348    top-of-stack of the previous frame, and the function part being the
 349    function's start address.  Since the correct identification of a
 350    frameless function requires both the a stack and function address,
 351    the old get_frame_base method was not sufficient.
 352
 353    get_frame_base_address: get_frame_locals_address:
 354    get_frame_args_address: A set of high-level debug-info dependant
 355    addresses that fall within the frame.  These addresses almost
 356    certainly will not match the stack address part of a frame ID (as
 357    returned by get_frame_base).
 358
 359    This replaced: frame->frame; */
 360
 361 extern CORE_ADDR get_frame_base (struct frame_info *);
 362
 363 /* Return the per-frame unique identifer.  Can be used to relocate a
 364    frame after a frame cache flush (and other similar operations).  If
 365    FI is NULL, return the null_frame_id.
 366
 367    NOTE: kettenis/20040508: These functions return a structure.  On
 368    platforms where structures are returned in static storage (vax,
 369    m68k), this may trigger compiler bugs in code like:
 370
 371    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 372
 373    where the return value from the first get_frame_id (l) gets
 374    overwritten by the second get_frame_id (r).  Please avoid writing
 375    code like this.  Use code like:
 376
 377    struct frame_id id = get_frame_id (l);
 378    if (frame_id_eq (id, get_frame_id (r)))
 379
 380    instead, since that avoids the bug.  */
 381 extern struct frame_id get_frame_id (struct frame_info *fi);
 382 extern struct frame_id frame_unwind_id (struct frame_info *next_frame);
 383
 384 /* Assuming that a frame is `normal', return its base-address, or 0 if
 385    the information isn't available.  NOTE: This address is really only
 386    meaningful to the frame's high-level debug info.  */
 387 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 388
 389 /* Assuming that a frame is `normal', return the base-address of the
 390    local variables, or 0 if the information isn't available.  NOTE:
 391    This address is really only meaningful to the frame's high-level
 392    debug info.  Typically, the argument and locals share a single
 393    base-address.  */
 394 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 395
 396 /* Assuming that a frame is `normal', return the base-address of the
 397    parameter list, or 0 if that information isn't available.  NOTE:
 398    This address is really only meaningful to the frame's high-level
 399    debug info.  Typically, the argument and locals share a single
 400    base-address.  */
 401 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 402
 403 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 404    for an invalid frame).  */
 405 extern int frame_relative_level (struct frame_info *fi);
 406
 407 /* Return the frame's type.  */
 408
 409 extern enum frame_type get_frame_type (struct frame_info *);
 410
 411 /* For frames where we can not unwind further, describe why.  */
 412
 413 enum unwind_stop_reason
 414   {
 415     /* No particular reason; either we haven't tried unwinding yet,
 416        or we didn't fail.  */
 417     UNWIND_NO_REASON,
 418
 419     /* The previous frame's analyzer returns an invalid result
 420        from this_id.
 421
 422        FIXME drow/2006-08-16: This is how GDB used to indicate end of
 423        stack.  We should migrate to a model where frames always have a
 424        valid ID, and this becomes not just an error but an internal
 425        error.  But that's a project for another day.  */
 426     UNWIND_NULL_ID,
 427
 428     /* All the conditions after this point are considered errors;
 429        abnormal stack termination.  If a backtrace stops for one
 430        of these reasons, we'll let the user know.  This marker
 431        is not a valid stop reason.  */
 432     UNWIND_FIRST_ERROR,
 433
 434     /* This frame ID looks like it ought to belong to a NEXT frame,
 435        but we got it for a PREV frame.  Normally, this is a sign of
 436        unwinder failure.  It could also indicate stack corruption.  */
 437     UNWIND_INNER_ID,
 438
 439     /* This frame has the same ID as the previous one.  That means
 440        that unwinding further would almost certainly give us another
 441        frame with exactly the same ID, so break the chain.  Normally,
 442        this is a sign of unwinder failure.  It could also indicate
 443        stack corruption.  */
 444     UNWIND_SAME_ID,
 445
 446     /* The frame unwinder didn't find any saved PC, but we needed
 447        one to unwind further.  */
 448     UNWIND_NO_SAVED_PC,
 449   };
 450
 451 /* Return the reason why we can't unwind past this frame.  */
 452
 453 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 454
 455 /* Translate a reason code to an informative string.  */
 456
 457 const char *frame_stop_reason_string (enum unwind_stop_reason);
 458
 459 /* Unwind the stack frame so that the value of REGNUM, in the previous
 460    (up, older) frame is returned.  If VALUEP is NULL, don't
 461    fetch/compute the value.  Instead just return the location of the
 462    value.  */
 463 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 464                                    int *optimizedp, enum lval_type *lvalp,
 465                                    CORE_ADDR *addrp, int *realnump,
 466                                    gdb_byte *valuep);
 467
 468 /* Fetch a register from this, or unwind a register from the next
 469    frame.  Note that the get_frame methods are wrappers to
 470    frame->next->unwind.  They all [potentially] throw an error if the
 471    fetch fails.  */
 472
 473 extern void frame_unwind_register (struct frame_info *frame,
 474                                    int regnum, gdb_byte *buf);
 475 extern void get_frame_register (struct frame_info *frame,
 476                                 int regnum, gdb_byte *buf);
 477
 478 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 479                                              int regnum);
 480 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 481                                           int regnum);
 482 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 483                                                int regnum);
 484 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 485                                              int regnum);
 486
 487
 488 /* Use frame_unwind_register_signed.  */
 489 extern void frame_unwind_unsigned_register (struct frame_info *frame,
 490                                             int regnum, ULONGEST *val);
 491
 492 /* Get the value of the register that belongs to this FRAME.  This
 493    function is a wrapper to the call sequence ``frame_register_unwind
 494    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 495    VALUEP is NULL, the registers value is not fetched/computed.  */
 496
 497 extern void frame_register (struct frame_info *frame, int regnum,
 498                             int *optimizedp, enum lval_type *lvalp,
 499                             CORE_ADDR *addrp, int *realnump,
 500                             gdb_byte *valuep);
 501
 502 /* The reverse.  Store a register value relative to the specified
 503    frame.  Note: this call makes the frame's state undefined.  The
 504    register and frame caches must be flushed.  */
 505 extern void put_frame_register (struct frame_info *frame, int regnum,
 506                                 const gdb_byte *buf);
 507
 508 /* Read LEN bytes from one or multiple registers starting with REGNUM
 509    in frame FRAME, starting at OFFSET, into BUF.  */
 510 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 511                                      CORE_ADDR offset, int len,
 512                                      gdb_byte *myaddr);
 513
 514 /* Write LEN bytes to one or multiple registers starting with REGNUM
 515    in frame FRAME, starting at OFFSET, into BUF.  */
 516 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 517                                       CORE_ADDR offset, int len,
 518                                       const gdb_byte *myaddr);
 519
 520 /* Map between a frame register number and its name.  A frame register
 521    space is a superset of the cooked register space --- it also
 522    includes builtin registers.  If NAMELEN is negative, use the NAME's
 523    length when doing the comparison.  */
 524
 525 extern int frame_map_name_to_regnum (struct frame_info *frame,
 526                                      const char *name, int namelen);
 527 extern const char *frame_map_regnum_to_name (struct frame_info *frame,
 528                                              int regnum);
 529
 530 /* Unwind the PC.  Strictly speaking return the resume address of the
 531    calling frame.  For GDB, `pc' is the resume address and not a
 532    specific register.  */
 533
 534 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
 535
 536 /* Discard the specified frame.  Restoring the registers to the state
 537    of the caller.  */
 538 extern void frame_pop (struct frame_info *frame);
 539
 540 /* Return memory from the specified frame.  A frame knows its thread /
 541    LWP and hence can find its way down to a target.  The assumption
 542    here is that the current and previous frame share a common address
 543    space.
 544
 545    If the memory read fails, these methods throw an error.
 546
 547    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 548    methods?  That isn't clear.  Can code, for instance, assume that
 549    this and the previous frame's memory or architecture are identical?
 550    If architecture / memory changes are always separated by special
 551    adaptor frames this should be ok.  */
 552
 553 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 554                               gdb_byte *buf, int len);
 555 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 556                                         CORE_ADDR memaddr, int len);
 557 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 558                                            CORE_ADDR memaddr, int len);
 559
 560 /* Same as above, but return non-zero when the entire memory read
 561    succeeds, zero otherwize.  */
 562 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 563                                      CORE_ADDR addr, gdb_byte *buf, int len);
 564
 565 /* Return this frame's architecture.  */
 566
 567 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 568
 569
 570 /* Values for the source flag to be used in print_frame_info_base().  */
 571 enum print_what
 572   {
 573     /* Print only the source line, like in stepi. */
 574     SRC_LINE = -1,
 575     /* Print only the location, i.e. level, address (sometimes)
 576        function, args, file, line, line num. */
 577     LOCATION,
 578     /* Print both of the above. */
 579     SRC_AND_LOC,
 580     /* Print location only, but always include the address. */
 581     LOC_AND_ADDRESS
 582   };
 583
 584 /* Allocate additional space for appendices to a struct frame_info.
 585    NOTE: Much of GDB's code works on the assumption that the allocated
 586    saved_regs[] array is the size specified below.  If you try to make
 587    that array smaller, GDB will happily walk off its end.  */
 588
 589 #ifdef SIZEOF_FRAME_SAVED_REGS
 590 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 591 #endif
 592 #define SIZEOF_FRAME_SAVED_REGS \
 593         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 594
 595 /* Allocate zero initialized memory from the frame cache obstack.
 596    Appendices to the frame info (such as the unwind cache) should
 597    allocate memory using this method.  */
 598
 599 extern void *frame_obstack_zalloc (unsigned long size);
 600 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 601 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 602
 603 /* Create a regcache, and copy the frame's registers into it.  */
 604 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 605
 606 extern struct block *get_frame_block (struct frame_info *,
 607                                       CORE_ADDR *addr_in_block);
 608
 609 /* Return the `struct block' that belongs to the selected thread's
 610    selected frame.  If the inferior has no state, return NULL.
 611
 612    NOTE: cagney/2002-11-29:
 613
 614    No state?  Does the inferior have any execution state (a core file
 615    does, an executable does not).  At present the code tests
 616    `target_has_stack' but I'm left wondering if it should test
 617    `target_has_registers' or, even, a merged target_has_state.
 618
 619    Should it look at the most recently specified SAL?  If the target
 620    has no state, should this function try to extract a block from the
 621    most recently selected SAL?  That way `list foo' would give it some
 622    sort of reference point.  Then again, perhaps that would confuse
 623    things.
 624
 625    Calls to this function can be broken down into two categories: Code
 626    that uses the selected block as an additional, but optional, data
 627    point; Code that uses the selected block as a prop, when it should
 628    have the relevant frame/block/pc explicitly passed in.
 629
 630    The latter can be eliminated by correctly parameterizing the code,
 631    the former though is more interesting.  Per the "address" command,
 632    it occurs in the CLI code and makes it possible for commands to
 633    work, even when the inferior has no state.  */
 634
 635 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 636
 637 extern struct symbol *get_frame_function (struct frame_info *);
 638
 639 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 640
 641 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 642
 643 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 644                                         enum print_what print_what);
 645
 646 extern void print_stack_frame (struct frame_info *, int print_level,
 647                                enum print_what print_what);
 648
 649 extern void show_stack_frame (struct frame_info *);
 650
 651 extern void print_frame_info (struct frame_info *, int print_level,
 652                               enum print_what print_what, int args);
 653
 654 extern struct frame_info *block_innermost_frame (struct block *);
 655
 656 extern int deprecated_pc_in_call_dummy (CORE_ADDR pc);
 657
 658 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 659    function called get_frame_register_p().  This slightly weird (and
 660    older) variant of get_frame_register() returns zero (indicating the
 661    register is unavailable) if either: the register isn't cached; or
 662    the register has been optimized out.  Problem is, neither check is
 663    exactly correct.  A register can't be optimized out (it may not
 664    have been saved as part of a function call); The fact that a
 665    register isn't in the register cache doesn't mean that the register
 666    isn't available (it could have been fetched from memory).  */
 667
 668 extern int frame_register_read (struct frame_info *frame, int regnum,
 669                                 gdb_byte *buf);
 670
 671 /* From stack.c.  */
 672 extern void args_info (char *, int);
 673
 674 extern void locals_info (char *, int);
 675
 676 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 677
 678 extern void return_command (char *, int);
 679
 680
 681 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 682
 683    You might think that calls to this function can simply be replaced by a
 684    call to get_selected_frame().
 685
 686    Unfortunately, it isn't that easy.
 687
 688    The relevant code needs to be audited to determine if it is
 689    possible (or practical) to instead pass the applicable frame in as a
 690    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 691    the deprecated_selected_frame global, while its replacement,
 692    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 693    The only real exceptions occur at the edge (in the CLI code) where
 694    user commands need to pick up the selected frame before proceeding.
 695
 696    There are also some functions called with a NULL frame meaning either "the
 697    program is not running" or "use the selected frame".
 698
 699    This is important.  GDB is trying to stamp out the hack:
 700
 701    saved_frame = deprecated_safe_get_selected_frame ();
 702    select_frame (...);
 703    hack_using_global_selected_frame ();
 704    select_frame (saved_frame);
 705
 706    Take care!
 707
 708    This function calls get_selected_frame if the inferior should have a
 709    frame, or returns NULL otherwise.  */
 710
 711 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 712
 713 /* Create a frame using the specified BASE and PC.  */
 714
 715 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 716
 717 /* FIXME: cagney/2002-12-06: Has the PC in the current frame changed?
 718    "infrun.c", Thanks to DECR_PC_AFTER_BREAK, can change the PC after
 719    the initial frame create.  This puts things back in sync.
 720
 721    This replaced: frame->pc = ....; */
 722 extern void deprecated_update_frame_pc_hack (struct frame_info *frame,
 723                                              CORE_ADDR pc);
 724
 725 /* FIXME: cagney/2002-12-18: Has the frame's base changed?  Or to be
 726    more exact, was that initial guess at the frame's base as returned
 727    by the deleted read_fp() wrong?  If it was, fix it.  This shouldn't
 728    be necessary since the code should be getting the frame's base
 729    correct from the outset.
 730
 731    This replaced: frame->frame = ....; */
 732 extern void deprecated_update_frame_base_hack (struct frame_info *frame,
 733                                                CORE_ADDR base);
 734
 735 #endif /* !defined (FRAME_H)  */