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