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, 2008, 2009
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  21
  22 #if !defined (FRAME_H)
  23 #define FRAME_H 1
  24
  25 /* The following is the intended naming schema for frame functions.
  26    It isn't 100% consistent, but it is aproaching that.  Frame naming
  27    schema:
  28
  29    Prefixes:
  30
  31    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  32    equivalent to THIS->next->unwind->what)
  33
  34    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  35    frame.
  36
  37    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  38    invalidate the frame / regcache afterwards) (better name more
  39    strongly hinting at its unsafeness)
  40
  41    safe_....(): Safer version of various functions, doesn't throw an
  42    error (leave this for later?).  Returns non-zero / non-NULL if the
  43    request succeeds, zero / NULL otherwize.
  44
  45    Suffixes:
  46
  47    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  48
  49    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  50    alternative is *frame_unsigned_WHAT).
  51
  52    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  53
  54    What:
  55
  56    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  57    *memory.
  58
  59    /frame/_register* (frame, regnum [, buf]): extract/return register.
  60
  61    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  62    stack *address, ...
  63
  64    */
  65
  66 struct symtab_and_line;
  67 struct frame_unwind;
  68 struct frame_base;
  69 struct block;
  70 struct gdbarch;
  71 struct ui_file;
  72
  73 /* The frame object.  */
  74
  75 struct frame_info;
  76
  77 /* The frame object's ID.  This provides a per-frame unique identifier
  78    that can be used to relocate a `struct frame_info' after a target
  79    resume or a frame cache destruct.  It of course assumes that the
  80    inferior hasn't unwound the stack past that frame.  */
  81
  82 struct frame_id
  83 {
  84   /* The frame's stack address.  This shall be constant through out
  85      the lifetime of a frame.  Note that this requirement applies to
  86      not just the function body, but also the prologue and (in theory
  87      at least) the epilogue.  Since that value needs to fall either on
  88      the boundary, or within the frame's address range, the frame's
  89      outer-most address (the inner-most address of the previous frame)
  90      is used.  Watch out for all the legacy targets that still use the
  91      function pointer register or stack pointer register.  They are
  92      wrong.
  93
  94      This field is valid only if stack_addr_p is true.  Otherwise, this
  95      frame represents the null frame.  */
  96   CORE_ADDR stack_addr;
  97
  98   /* The frame's code address.  This shall be constant through out the
  99      lifetime of the frame.  While the PC (a.k.a. resume address)
 100      changes as the function is executed, this code address cannot.
 101      Typically, it is set to the address of the entry point of the
 102      frame's function (as returned by get_frame_func).
 103
 104      This field is valid only if code_addr_p is true.  Otherwise, this
 105      frame is considered to have a wildcard code address, i.e. one that
 106      matches every address value in frame comparisons.  */
 107   CORE_ADDR code_addr;
 108
 109   /* The frame's special address.  This shall be constant through out the
 110      lifetime of the frame.  This is used for architectures that may have
 111      frames that do not change the stack but are still distinct and have
 112      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 113      stack for registers).  This field is treated as unordered - i.e. will
 114      not be used in frame ordering comparisons.
 115
 116      This field is valid only if special_addr_p is true.  Otherwise, this
 117      frame is considered to have a wildcard special address, i.e. one that
 118      matches every address value in frame comparisons.  */
 119   CORE_ADDR special_addr;
 120
 121   /* Flags to indicate the above fields have valid contents.  */
 122   unsigned int stack_addr_p : 1;
 123   unsigned int code_addr_p : 1;
 124   unsigned int special_addr_p : 1;
 125 };
 126
 127 /* Methods for constructing and comparing Frame IDs.  */
 128
 129 /* For convenience.  All fields are zero.  */
 130 extern const struct frame_id null_frame_id;
 131
 132 /* Flag to control debugging.  */
 133
 134 extern int frame_debug;
 135
 136 /* Construct a frame ID.  The first parameter is the frame's constant
 137    stack address (typically the outer-bound), and the second the
 138    frame's constant code address (typically the entry point).
 139    The special identifier address is set to indicate a wild card.  */
 140 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 141                                        CORE_ADDR code_addr);
 142
 143 /* Construct a special frame ID.  The first parameter is the frame's constant
 144    stack address (typically the outer-bound), the second is the
 145    frame's constant code address (typically the entry point),
 146    and the third parameter is the frame's special identifier address. */
 147 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 148                                                CORE_ADDR code_addr,
 149                                                CORE_ADDR special_addr);
 150
 151 /* Construct a wild card frame ID.  The parameter is the frame's constant
 152    stack address (typically the outer-bound).  The code address as well
 153    as the special identifier address are set to indicate wild cards.  */
 154 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 155
 156 /* Returns non-zero when L is a valid frame (a valid frame has a
 157    non-zero .base).  */
 158 extern int frame_id_p (struct frame_id l);
 159
 160 /* Returns non-zero when L and R identify the same frame, or, if
 161    either L or R have a zero .func, then the same frame base.  */
 162 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 163
 164 /* Write the internal representation of a frame ID on the specified
 165    stream.  */
 166 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 167
 168
 169 /* Frame types.  Some are real, some are signal trampolines, and some
 170    are completely artificial (dummy).  */
 171
 172 enum frame_type
 173 {
 174   /* A true stack frame, created by the target program during normal
 175      execution.  */
 176   NORMAL_FRAME,
 177   /* A fake frame, created by GDB when performing an inferior function
 178      call.  */
 179   DUMMY_FRAME,
 180   /* In a signal handler, various OSs handle this in various ways.
 181      The main thing is that the frame may be far from normal.  */
 182   SIGTRAMP_FRAME,
 183   /* Sentinel or registers frame.  This frame obtains register values
 184      direct from the inferior's registers.  */
 185   SENTINEL_FRAME
 186 };
 187
 188 /* For every stopped thread, GDB tracks two frames: current and
 189    selected.  Current frame is the inner most frame of the selected
 190    thread.  Selected frame is the one being examined by the the GDB
 191    CLI (selected using `up', `down', ...).  The frames are created
 192    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 193 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 194    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 195    selected frame.  At present GDB only tracks the selected frame of
 196    the current thread.  But be warned, that might change.  */
 197 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 198    and current frame can be active.  Switching threads causes gdb to
 199    discard all that cached frame information.  Ulgh!  Instead, current
 200    and selected frame should be bound to a thread.  */
 201
 202 /* On demand, create the inner most frame using information found in
 203    the inferior.  If the inner most frame can't be created, throw an
 204    error.  */
 205 extern struct frame_info *get_current_frame (void);
 206
 207 /* Invalidates the frame cache (this function should have been called
 208    invalidate_cached_frames).
 209
 210    FIXME: cagney/2002-11-28: There should be two methods: one that
 211    reverts the thread's selected frame back to current frame (for when
 212    the inferior resumes) and one that does not (for when the user
 213    modifies the target invalidating the frame cache).  */
 214 extern void reinit_frame_cache (void);
 215
 216 /* On demand, create the selected frame and then return it.  If the
 217    selected frame can not be created, this function prints then throws
 218    an error.  When MESSAGE is non-NULL, use it for the error message,
 219    otherwize use a generic error message.  */
 220 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 221    frame, this function always returns the current (inner most) frame.
 222    It should instead, when a thread has previously had its frame
 223    selected (but not resumed) and the frame cache invalidated, find
 224    and then return that thread's previously selected frame.  */
 225 extern struct frame_info *get_selected_frame (const char *message);
 226
 227 /* Select a specific frame.  NULL, apparently implies re-select the
 228    inner most frame.  */
 229 extern void select_frame (struct frame_info *);
 230
 231 /* Given a FRAME, return the next (more inner, younger) or previous
 232    (more outer, older) frame.  */
 233 extern struct frame_info *get_prev_frame (struct frame_info *);
 234 extern struct frame_info *get_next_frame (struct frame_info *);
 235
 236 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 237    is not found.  */
 238 extern struct frame_info *frame_find_by_id (struct frame_id id);
 239
 240 /* Base attributes of a frame: */
 241
 242 /* The frame's `resume' address.  Where the program will resume in
 243    this frame.
 244
 245    This replaced: frame->pc; */
 246 extern CORE_ADDR get_frame_pc (struct frame_info *);
 247
 248 /* An address (not necessarily aligned to an instruction boundary)
 249    that falls within THIS frame's code block.
 250
 251    When a function call is the last statement in a block, the return
 252    address for the call may land at the start of the next block.
 253    Similarly, if a no-return function call is the last statement in
 254    the function, the return address may end up pointing beyond the
 255    function, and possibly at the start of the next function.
 256
 257    These methods make an allowance for this.  For call frames, this
 258    function returns the frame's PC-1 which "should" be an address in
 259    the frame's block.  */
 260
 261 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 262
 263 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 264    known as top-of-stack.  */
 265
 266 extern CORE_ADDR get_frame_sp (struct frame_info *);
 267
 268 /* Following on from the `resume' address.  Return the entry point
 269    address of the function containing that resume address, or zero if
 270    that function isn't known.  */
 271 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 272
 273 /* Closely related to the resume address, various symbol table
 274    attributes that are determined by the PC.  Note that for a normal
 275    frame, the PC refers to the resume address after the return, and
 276    not the call instruction.  In such a case, the address is adjusted
 277    so that it (approximately) identifies the call site (and not the
 278    return site).
 279
 280    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 281    computed value.  Working on the assumption that the bottle-neck is
 282    in the single step code, and that code causes the frame cache to be
 283    constantly flushed, caching things in a frame is probably of little
 284    benefit.  As they say `show us the numbers'.
 285
 286    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 287    find_frame_block(), find_frame_partial_function(),
 288    find_frame_symtab(), find_frame_function().  Each will need to be
 289    carefully considered to determine if the real intent was for it to
 290    apply to the PC or the adjusted PC.  */
 291 extern void find_frame_sal (struct frame_info *frame,
 292                             struct symtab_and_line *sal);
 293
 294 /* Set the current source and line to the location given by frame
 295    FRAME, if possible.  When CENTER is true, adjust so the relevant
 296    line is in the center of the next 'list'.  */
 297
 298 void set_current_sal_from_frame (struct frame_info *, int);
 299
 300 /* Return the frame base (what ever that is) (DEPRECATED).
 301
 302    Old code was trying to use this single method for two conflicting
 303    purposes.  Such code needs to be updated to use either of:
 304
 305    get_frame_id: A low level frame unique identifier, that consists of
 306    both a stack and a function address, that can be used to uniquely
 307    identify a frame.  This value is determined by the frame's
 308    low-level unwinder, the stack part [typically] being the
 309    top-of-stack of the previous frame, and the function part being the
 310    function's start address.  Since the correct identification of a
 311    frameless function requires both the a stack and function address,
 312    the old get_frame_base method was not sufficient.
 313
 314    get_frame_base_address: get_frame_locals_address:
 315    get_frame_args_address: A set of high-level debug-info dependant
 316    addresses that fall within the frame.  These addresses almost
 317    certainly will not match the stack address part of a frame ID (as
 318    returned by get_frame_base).
 319
 320    This replaced: frame->frame; */
 321
 322 extern CORE_ADDR get_frame_base (struct frame_info *);
 323
 324 /* Return the per-frame unique identifer.  Can be used to relocate a
 325    frame after a frame cache flush (and other similar operations).  If
 326    FI is NULL, return the null_frame_id.
 327
 328    NOTE: kettenis/20040508: These functions return a structure.  On
 329    platforms where structures are returned in static storage (vax,
 330    m68k), this may trigger compiler bugs in code like:
 331
 332    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 333
 334    where the return value from the first get_frame_id (l) gets
 335    overwritten by the second get_frame_id (r).  Please avoid writing
 336    code like this.  Use code like:
 337
 338    struct frame_id id = get_frame_id (l);
 339    if (frame_id_eq (id, get_frame_id (r)))
 340
 341    instead, since that avoids the bug.  */
 342 extern struct frame_id get_frame_id (struct frame_info *fi);
 343 extern struct frame_id frame_unwind_id (struct frame_info *next_frame);
 344
 345 /* Assuming that a frame is `normal', return its base-address, or 0 if
 346    the information isn't available.  NOTE: This address is really only
 347    meaningful to the frame's high-level debug info.  */
 348 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 349
 350 /* Assuming that a frame is `normal', return the base-address of the
 351    local variables, or 0 if the information isn't available.  NOTE:
 352    This address is really only meaningful to the frame's high-level
 353    debug info.  Typically, the argument and locals share a single
 354    base-address.  */
 355 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 356
 357 /* Assuming that a frame is `normal', return the base-address of the
 358    parameter list, or 0 if that information isn't available.  NOTE:
 359    This address is really only meaningful to the frame's high-level
 360    debug info.  Typically, the argument and locals share a single
 361    base-address.  */
 362 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 363
 364 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 365    for an invalid frame).  */
 366 extern int frame_relative_level (struct frame_info *fi);
 367
 368 /* Return the frame's type.  */
 369
 370 extern enum frame_type get_frame_type (struct frame_info *);
 371
 372 /* For frames where we can not unwind further, describe why.  */
 373
 374 enum unwind_stop_reason
 375   {
 376     /* No particular reason; either we haven't tried unwinding yet,
 377        or we didn't fail.  */
 378     UNWIND_NO_REASON,
 379
 380     /* The previous frame's analyzer returns an invalid result
 381        from this_id.
 382
 383        FIXME drow/2006-08-16: This is how GDB used to indicate end of
 384        stack.  We should migrate to a model where frames always have a
 385        valid ID, and this becomes not just an error but an internal
 386        error.  But that's a project for another day.  */
 387     UNWIND_NULL_ID,
 388
 389     /* All the conditions after this point are considered errors;
 390        abnormal stack termination.  If a backtrace stops for one
 391        of these reasons, we'll let the user know.  This marker
 392        is not a valid stop reason.  */
 393     UNWIND_FIRST_ERROR,
 394
 395     /* This frame ID looks like it ought to belong to a NEXT frame,
 396        but we got it for a PREV frame.  Normally, this is a sign of
 397        unwinder failure.  It could also indicate stack corruption.  */
 398     UNWIND_INNER_ID,
 399
 400     /* This frame has the same ID as the previous one.  That means
 401        that unwinding further would almost certainly give us another
 402        frame with exactly the same ID, so break the chain.  Normally,
 403        this is a sign of unwinder failure.  It could also indicate
 404        stack corruption.  */
 405     UNWIND_SAME_ID,
 406
 407     /* The frame unwinder didn't find any saved PC, but we needed
 408        one to unwind further.  */
 409     UNWIND_NO_SAVED_PC,
 410   };
 411
 412 /* Return the reason why we can't unwind past this frame.  */
 413
 414 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 415
 416 /* Translate a reason code to an informative string.  */
 417
 418 const char *frame_stop_reason_string (enum unwind_stop_reason);
 419
 420 /* Unwind the stack frame so that the value of REGNUM, in the previous
 421    (up, older) frame is returned.  If VALUEP is NULL, don't
 422    fetch/compute the value.  Instead just return the location of the
 423    value.  */
 424 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 425                                    int *optimizedp, enum lval_type *lvalp,
 426                                    CORE_ADDR *addrp, int *realnump,
 427                                    gdb_byte *valuep);
 428
 429 /* Fetch a register from this, or unwind a register from the next
 430    frame.  Note that the get_frame methods are wrappers to
 431    frame->next->unwind.  They all [potentially] throw an error if the
 432    fetch fails.  The value methods never return NULL, but usually
 433    do return a lazy value.  */
 434
 435 extern void frame_unwind_register (struct frame_info *frame,
 436                                    int regnum, gdb_byte *buf);
 437 extern void get_frame_register (struct frame_info *frame,
 438                                 int regnum, gdb_byte *buf);
 439
 440 struct value *frame_unwind_register_value (struct frame_info *frame,
 441                                            int regnum);
 442 struct value *get_frame_register_value (struct frame_info *frame,
 443                                         int regnum);
 444
 445 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 446                                              int regnum);
 447 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 448                                           int regnum);
 449 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 450                                                int regnum);
 451 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 452                                              int regnum);
 453
 454
 455 /* Get the value of the register that belongs to this FRAME.  This
 456    function is a wrapper to the call sequence ``frame_register_unwind
 457    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 458    VALUEP is NULL, the registers value is not fetched/computed.  */
 459
 460 extern void frame_register (struct frame_info *frame, int regnum,
 461                             int *optimizedp, enum lval_type *lvalp,
 462                             CORE_ADDR *addrp, int *realnump,
 463                             gdb_byte *valuep);
 464
 465 /* The reverse.  Store a register value relative to the specified
 466    frame.  Note: this call makes the frame's state undefined.  The
 467    register and frame caches must be flushed.  */
 468 extern void put_frame_register (struct frame_info *frame, int regnum,
 469                                 const gdb_byte *buf);
 470
 471 /* Read LEN bytes from one or multiple registers starting with REGNUM
 472    in frame FRAME, starting at OFFSET, into BUF.  */
 473 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 474                                      CORE_ADDR offset, int len,
 475                                      gdb_byte *myaddr);
 476
 477 /* Write LEN bytes to one or multiple registers starting with REGNUM
 478    in frame FRAME, starting at OFFSET, into BUF.  */
 479 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 480                                       CORE_ADDR offset, int len,
 481                                       const gdb_byte *myaddr);
 482
 483 /* Unwind the PC.  Strictly speaking return the resume address of the
 484    calling frame.  For GDB, `pc' is the resume address and not a
 485    specific register.  */
 486
 487 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
 488
 489 /* Discard the specified frame.  Restoring the registers to the state
 490    of the caller.  */
 491 extern void frame_pop (struct frame_info *frame);
 492
 493 /* Return memory from the specified frame.  A frame knows its thread /
 494    LWP and hence can find its way down to a target.  The assumption
 495    here is that the current and previous frame share a common address
 496    space.
 497
 498    If the memory read fails, these methods throw an error.
 499
 500    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 501    methods?  That isn't clear.  Can code, for instance, assume that
 502    this and the previous frame's memory or architecture are identical?
 503    If architecture / memory changes are always separated by special
 504    adaptor frames this should be ok.  */
 505
 506 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 507                               gdb_byte *buf, int len);
 508 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 509                                         CORE_ADDR memaddr, int len);
 510 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 511                                            CORE_ADDR memaddr, int len);
 512
 513 /* Same as above, but return non-zero when the entire memory read
 514    succeeds, zero otherwize.  */
 515 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 516                                      CORE_ADDR addr, gdb_byte *buf, int len);
 517
 518 /* Return this frame's architecture.  */
 519
 520 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 521
 522
 523 /* Values for the source flag to be used in print_frame_info_base().  */
 524 enum print_what
 525   {
 526     /* Print only the source line, like in stepi. */
 527     SRC_LINE = -1,
 528     /* Print only the location, i.e. level, address (sometimes)
 529        function, args, file, line, line num. */
 530     LOCATION,
 531     /* Print both of the above. */
 532     SRC_AND_LOC,
 533     /* Print location only, but always include the address. */
 534     LOC_AND_ADDRESS
 535   };
 536
 537 /* Allocate zero initialized memory from the frame cache obstack.
 538    Appendices to the frame info (such as the unwind cache) should
 539    allocate memory using this method.  */
 540
 541 extern void *frame_obstack_zalloc (unsigned long size);
 542 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 543 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 544
 545 /* Create a regcache, and copy the frame's registers into it.  */
 546 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 547
 548 extern struct block *get_frame_block (struct frame_info *,
 549                                       CORE_ADDR *addr_in_block);
 550
 551 /* Return the `struct block' that belongs to the selected thread's
 552    selected frame.  If the inferior has no state, return NULL.
 553
 554    NOTE: cagney/2002-11-29:
 555
 556    No state?  Does the inferior have any execution state (a core file
 557    does, an executable does not).  At present the code tests
 558    `target_has_stack' but I'm left wondering if it should test
 559    `target_has_registers' or, even, a merged target_has_state.
 560
 561    Should it look at the most recently specified SAL?  If the target
 562    has no state, should this function try to extract a block from the
 563    most recently selected SAL?  That way `list foo' would give it some
 564    sort of reference point.  Then again, perhaps that would confuse
 565    things.
 566
 567    Calls to this function can be broken down into two categories: Code
 568    that uses the selected block as an additional, but optional, data
 569    point; Code that uses the selected block as a prop, when it should
 570    have the relevant frame/block/pc explicitly passed in.
 571
 572    The latter can be eliminated by correctly parameterizing the code,
 573    the former though is more interesting.  Per the "address" command,
 574    it occurs in the CLI code and makes it possible for commands to
 575    work, even when the inferior has no state.  */
 576
 577 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 578
 579 extern struct symbol *get_frame_function (struct frame_info *);
 580
 581 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 582
 583 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 584
 585 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 586                                         enum print_what print_what);
 587
 588 extern void print_stack_frame (struct frame_info *, int print_level,
 589                                enum print_what print_what);
 590
 591 extern void print_frame_info (struct frame_info *, int print_level,
 592                               enum print_what print_what, int args);
 593
 594 extern struct frame_info *block_innermost_frame (struct block *);
 595
 596 extern int deprecated_pc_in_call_dummy (CORE_ADDR pc);
 597
 598 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 599    function called get_frame_register_p().  This slightly weird (and
 600    older) variant of get_frame_register() returns zero (indicating the
 601    register is unavailable) if either: the register isn't cached; or
 602    the register has been optimized out.  Problem is, neither check is
 603    exactly correct.  A register can't be optimized out (it may not
 604    have been saved as part of a function call); The fact that a
 605    register isn't in the register cache doesn't mean that the register
 606    isn't available (it could have been fetched from memory).  */
 607
 608 extern int frame_register_read (struct frame_info *frame, int regnum,
 609                                 gdb_byte *buf);
 610
 611 /* From stack.c.  */
 612 extern void args_info (char *, int);
 613
 614 extern void locals_info (char *, int);
 615
 616 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 617
 618 extern void return_command (char *, int);
 619
 620 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 621    Return a cleanup which should be called if unwinding fails, and
 622    discarded if it succeeds.  */
 623
 624 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 625                                            const struct frame_unwind *unwind);
 626
 627 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 628
 629    You might think that calls to this function can simply be replaced by a
 630    call to get_selected_frame().
 631
 632    Unfortunately, it isn't that easy.
 633
 634    The relevant code needs to be audited to determine if it is
 635    possible (or practical) to instead pass the applicable frame in as a
 636    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 637    the deprecated_selected_frame global, while its replacement,
 638    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 639    The only real exceptions occur at the edge (in the CLI code) where
 640    user commands need to pick up the selected frame before proceeding.
 641
 642    There are also some functions called with a NULL frame meaning either "the
 643    program is not running" or "use the selected frame".
 644
 645    This is important.  GDB is trying to stamp out the hack:
 646
 647    saved_frame = deprecated_safe_get_selected_frame ();
 648    select_frame (...);
 649    hack_using_global_selected_frame ();
 650    select_frame (saved_frame);
 651
 652    Take care!
 653
 654    This function calls get_selected_frame if the inferior should have a
 655    frame, or returns NULL otherwise.  */
 656
 657 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 658
 659 /* Create a frame using the specified BASE and PC.  */
 660
 661 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 662
 663 #endif /* !defined (FRAME_H)  */