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