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 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 285    known as top-of-stack.  */
 286
 287 extern CORE_ADDR get_frame_sp (struct frame_info *);
 288 extern CORE_ADDR frame_sp_unwind (struct frame_info *);
 289
 290
 291 /* Following on from the `resume' address.  Return the entry point
 292    address of the function containing that resume address, or zero if
 293    that function isn't known.  */
 294 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 295
 296 /* Closely related to the resume address, various symbol table
 297    attributes that are determined by the PC.  Note that for a normal
 298    frame, the PC refers to the resume address after the return, and
 299    not the call instruction.  In such a case, the address is adjusted
 300    so that it (approximately) identifies the call site (and not the
 301    return site).
 302
 303    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 304    computed value.  Working on the assumption that the bottle-neck is
 305    in the single step code, and that code causes the frame cache to be
 306    constantly flushed, caching things in a frame is probably of little
 307    benefit.  As they say `show us the numbers'.
 308
 309    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 310    find_frame_block(), find_frame_partial_function(),
 311    find_frame_symtab(), find_frame_function().  Each will need to be
 312    carefully considered to determine if the real intent was for it to
 313    apply to the PC or the adjusted PC.  */
 314 extern void find_frame_sal (struct frame_info *frame,
 315                             struct symtab_and_line *sal);
 316
 317 /* Set the current source and line to the location given by frame
 318    FRAME, if possible.  When CENTER is true, adjust so the relevant
 319    line is in the center of the next 'list'.  */
 320
 321 void set_current_sal_from_frame (struct frame_info *, int);
 322
 323 /* Return the frame base (what ever that is) (DEPRECATED).
 324
 325    Old code was trying to use this single method for two conflicting
 326    purposes.  Such code needs to be updated to use either of:
 327
 328    get_frame_id: A low level frame unique identifier, that consists of
 329    both a stack and a function address, that can be used to uniquely
 330    identify a frame.  This value is determined by the frame's
 331    low-level unwinder, the stack part [typically] being the
 332    top-of-stack of the previous frame, and the function part being the
 333    function's start address.  Since the correct identification of a
 334    frameless function requires both the a stack and function address,
 335    the old get_frame_base method was not sufficient.
 336
 337    get_frame_base_address: get_frame_locals_address:
 338    get_frame_args_address: A set of high-level debug-info dependant
 339    addresses that fall within the frame.  These addresses almost
 340    certainly will not match the stack address part of a frame ID (as
 341    returned by get_frame_base).
 342
 343    This replaced: frame->frame; */
 344
 345 extern CORE_ADDR get_frame_base (struct frame_info *);
 346
 347 /* Return the per-frame unique identifer.  Can be used to relocate a
 348    frame after a frame cache flush (and other similar operations).  If
 349    FI is NULL, return the null_frame_id.
 350
 351    NOTE: kettenis/20040508: These functions return a structure.  On
 352    platforms where structures are returned in static storage (vax,
 353    m68k), this may trigger compiler bugs in code like:
 354
 355    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 356
 357    where the return value from the first get_frame_id (l) gets
 358    overwritten by the second get_frame_id (r).  Please avoid writing
 359    code like this.  Use code like:
 360
 361    struct frame_id id = get_frame_id (l);
 362    if (frame_id_eq (id, get_frame_id (r)))
 363
 364    instead, since that avoids the bug.  */
 365 extern struct frame_id get_frame_id (struct frame_info *fi);
 366 extern struct frame_id frame_unwind_id (struct frame_info *next_frame);
 367
 368 /* Assuming that a frame is `normal', return its base-address, or 0 if
 369    the information isn't available.  NOTE: This address is really only
 370    meaningful to the frame's high-level debug info.  */
 371 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 372
 373 /* Assuming that a frame is `normal', return the base-address of the
 374    local variables, or 0 if the information isn't available.  NOTE:
 375    This address is really only meaningful to the frame's high-level
 376    debug info.  Typically, the argument and locals share a single
 377    base-address.  */
 378 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 379
 380 /* Assuming that a frame is `normal', return the base-address of the
 381    parameter list, or 0 if that 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_args_address (struct frame_info *);
 386
 387 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 388    for an invalid frame).  */
 389 extern int frame_relative_level (struct frame_info *fi);
 390
 391 /* Return the frame's type.  */
 392
 393 extern enum frame_type get_frame_type (struct frame_info *);
 394
 395 /* For frames where we can not unwind further, describe why.  */
 396
 397 enum unwind_stop_reason
 398   {
 399     /* No particular reason; either we haven't tried unwinding yet,
 400        or we didn't fail.  */
 401     UNWIND_NO_REASON,
 402
 403     /* The previous frame's analyzer returns an invalid result
 404        from this_id.
 405
 406        FIXME drow/2006-08-16: This is how GDB used to indicate end of
 407        stack.  We should migrate to a model where frames always have a
 408        valid ID, and this becomes not just an error but an internal
 409        error.  But that's a project for another day.  */
 410     UNWIND_NULL_ID,
 411
 412     /* All the conditions after this point are considered errors;
 413        abnormal stack termination.  If a backtrace stops for one
 414        of these reasons, we'll let the user know.  This marker
 415        is not a valid stop reason.  */
 416     UNWIND_FIRST_ERROR,
 417
 418     /* This frame ID looks like it ought to belong to a NEXT frame,
 419        but we got it for a PREV frame.  Normally, this is a sign of
 420        unwinder failure.  It could also indicate stack corruption.  */
 421     UNWIND_INNER_ID,
 422
 423     /* This frame has the same ID as the previous one.  That means
 424        that unwinding further would almost certainly give us another
 425        frame with exactly the same ID, so break the chain.  Normally,
 426        this is a sign of unwinder failure.  It could also indicate
 427        stack corruption.  */
 428     UNWIND_SAME_ID,
 429
 430     /* The frame unwinder didn't find any saved PC, but we needed
 431        one to unwind further.  */
 432     UNWIND_NO_SAVED_PC,
 433   };
 434
 435 /* Return the reason why we can't unwind past this frame.  */
 436
 437 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 438
 439 /* Translate a reason code to an informative string.  */
 440
 441 const char *frame_stop_reason_string (enum unwind_stop_reason);
 442
 443 /* Unwind the stack frame so that the value of REGNUM, in the previous
 444    (up, older) frame is returned.  If VALUEP is NULL, don't
 445    fetch/compute the value.  Instead just return the location of the
 446    value.  */
 447 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 448                                    int *optimizedp, enum lval_type *lvalp,
 449                                    CORE_ADDR *addrp, int *realnump,
 450                                    gdb_byte *valuep);
 451
 452 /* Fetch a register from this, or unwind a register from the next
 453    frame.  Note that the get_frame methods are wrappers to
 454    frame->next->unwind.  They all [potentially] throw an error if the
 455    fetch fails.  The value methods never return NULL, but usually
 456    do return a lazy value.  */
 457
 458 extern void frame_unwind_register (struct frame_info *frame,
 459                                    int regnum, gdb_byte *buf);
 460 extern void get_frame_register (struct frame_info *frame,
 461                                 int regnum, gdb_byte *buf);
 462
 463 struct value *frame_unwind_register_value (struct frame_info *frame,
 464                                            int regnum);
 465 struct value *get_frame_register_value (struct frame_info *frame,
 466                                         int regnum);
 467
 468 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 469                                              int regnum);
 470 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 471                                           int regnum);
 472 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 473                                                int regnum);
 474 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 475                                              int regnum);
 476
 477
 478 /* Get the value of the register that belongs to this FRAME.  This
 479    function is a wrapper to the call sequence ``frame_register_unwind
 480    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 481    VALUEP is NULL, the registers value is not fetched/computed.  */
 482
 483 extern void frame_register (struct frame_info *frame, int regnum,
 484                             int *optimizedp, enum lval_type *lvalp,
 485                             CORE_ADDR *addrp, int *realnump,
 486                             gdb_byte *valuep);
 487
 488 /* The reverse.  Store a register value relative to the specified
 489    frame.  Note: this call makes the frame's state undefined.  The
 490    register and frame caches must be flushed.  */
 491 extern void put_frame_register (struct frame_info *frame, int regnum,
 492                                 const gdb_byte *buf);
 493
 494 /* Read LEN bytes from one or multiple registers starting with REGNUM
 495    in frame FRAME, starting at OFFSET, into BUF.  */
 496 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 497                                      CORE_ADDR offset, int len,
 498                                      gdb_byte *myaddr);
 499
 500 /* Write LEN bytes to one or multiple registers starting with REGNUM
 501    in frame FRAME, starting at OFFSET, into BUF.  */
 502 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 503                                       CORE_ADDR offset, int len,
 504                                       const gdb_byte *myaddr);
 505
 506 /* Map between a frame register number and its name.  A frame register
 507    space is a superset of the cooked register space --- it also
 508    includes builtin registers.  If NAMELEN is negative, use the NAME's
 509    length when doing the comparison.  */
 510
 511 extern int frame_map_name_to_regnum (struct frame_info *frame,
 512                                      const char *name, int namelen);
 513 extern const char *frame_map_regnum_to_name (struct frame_info *frame,
 514                                              int regnum);
 515
 516 /* Unwind the PC.  Strictly speaking return the resume address of the
 517    calling frame.  For GDB, `pc' is the resume address and not a
 518    specific register.  */
 519
 520 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
 521
 522 /* Discard the specified frame.  Restoring the registers to the state
 523    of the caller.  */
 524 extern void frame_pop (struct frame_info *frame);
 525
 526 /* Return memory from the specified frame.  A frame knows its thread /
 527    LWP and hence can find its way down to a target.  The assumption
 528    here is that the current and previous frame share a common address
 529    space.
 530
 531    If the memory read fails, these methods throw an error.
 532
 533    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 534    methods?  That isn't clear.  Can code, for instance, assume that
 535    this and the previous frame's memory or architecture are identical?
 536    If architecture / memory changes are always separated by special
 537    adaptor frames this should be ok.  */
 538
 539 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 540                               gdb_byte *buf, int len);
 541 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 542                                         CORE_ADDR memaddr, int len);
 543 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 544                                            CORE_ADDR memaddr, int len);
 545
 546 /* Same as above, but return non-zero when the entire memory read
 547    succeeds, zero otherwize.  */
 548 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 549                                      CORE_ADDR addr, gdb_byte *buf, int len);
 550
 551 /* Return this frame's architecture.  */
 552
 553 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 554
 555
 556 /* Values for the source flag to be used in print_frame_info_base().  */
 557 enum print_what
 558   {
 559     /* Print only the source line, like in stepi. */
 560     SRC_LINE = -1,
 561     /* Print only the location, i.e. level, address (sometimes)
 562        function, args, file, line, line num. */
 563     LOCATION,
 564     /* Print both of the above. */
 565     SRC_AND_LOC,
 566     /* Print location only, but always include the address. */
 567     LOC_AND_ADDRESS
 568   };
 569
 570 /* Allocate zero initialized memory from the frame cache obstack.
 571    Appendices to the frame info (such as the unwind cache) should
 572    allocate memory using this method.  */
 573
 574 extern void *frame_obstack_zalloc (unsigned long size);
 575 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 576 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 577
 578 /* Create a regcache, and copy the frame's registers into it.  */
 579 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 580
 581 extern struct block *get_frame_block (struct frame_info *,
 582                                       CORE_ADDR *addr_in_block);
 583
 584 /* Return the `struct block' that belongs to the selected thread's
 585    selected frame.  If the inferior has no state, return NULL.
 586
 587    NOTE: cagney/2002-11-29:
 588
 589    No state?  Does the inferior have any execution state (a core file
 590    does, an executable does not).  At present the code tests
 591    `target_has_stack' but I'm left wondering if it should test
 592    `target_has_registers' or, even, a merged target_has_state.
 593
 594    Should it look at the most recently specified SAL?  If the target
 595    has no state, should this function try to extract a block from the
 596    most recently selected SAL?  That way `list foo' would give it some
 597    sort of reference point.  Then again, perhaps that would confuse
 598    things.
 599
 600    Calls to this function can be broken down into two categories: Code
 601    that uses the selected block as an additional, but optional, data
 602    point; Code that uses the selected block as a prop, when it should
 603    have the relevant frame/block/pc explicitly passed in.
 604
 605    The latter can be eliminated by correctly parameterizing the code,
 606    the former though is more interesting.  Per the "address" command,
 607    it occurs in the CLI code and makes it possible for commands to
 608    work, even when the inferior has no state.  */
 609
 610 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 611
 612 extern struct symbol *get_frame_function (struct frame_info *);
 613
 614 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 615
 616 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 617
 618 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 619                                         enum print_what print_what);
 620
 621 extern void print_stack_frame (struct frame_info *, int print_level,
 622                                enum print_what print_what);
 623
 624 extern void print_frame_info (struct frame_info *, int print_level,
 625                               enum print_what print_what, int args);
 626
 627 extern struct frame_info *block_innermost_frame (struct block *);
 628
 629 extern int deprecated_pc_in_call_dummy (CORE_ADDR pc);
 630
 631 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 632    function called get_frame_register_p().  This slightly weird (and
 633    older) variant of get_frame_register() returns zero (indicating the
 634    register is unavailable) if either: the register isn't cached; or
 635    the register has been optimized out.  Problem is, neither check is
 636    exactly correct.  A register can't be optimized out (it may not
 637    have been saved as part of a function call); The fact that a
 638    register isn't in the register cache doesn't mean that the register
 639    isn't available (it could have been fetched from memory).  */
 640
 641 extern int frame_register_read (struct frame_info *frame, int regnum,
 642                                 gdb_byte *buf);
 643
 644 /* From stack.c.  */
 645 extern void args_info (char *, int);
 646
 647 extern void locals_info (char *, int);
 648
 649 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 650
 651 extern void return_command (char *, int);
 652
 653 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 654    Return a cleanup which should be called if unwinding fails, and
 655    discarded if it succeeds.  */
 656
 657 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 658                                            const struct frame_unwind *unwind);
 659
 660 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 661
 662    You might think that calls to this function can simply be replaced by a
 663    call to get_selected_frame().
 664
 665    Unfortunately, it isn't that easy.
 666
 667    The relevant code needs to be audited to determine if it is
 668    possible (or practical) to instead pass the applicable frame in as a
 669    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 670    the deprecated_selected_frame global, while its replacement,
 671    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 672    The only real exceptions occur at the edge (in the CLI code) where
 673    user commands need to pick up the selected frame before proceeding.
 674
 675    There are also some functions called with a NULL frame meaning either "the
 676    program is not running" or "use the selected frame".
 677
 678    This is important.  GDB is trying to stamp out the hack:
 679
 680    saved_frame = deprecated_safe_get_selected_frame ();
 681    select_frame (...);
 682    hack_using_global_selected_frame ();
 683    select_frame (saved_frame);
 684
 685    Take care!
 686
 687    This function calls get_selected_frame if the inferior should have a
 688    frame, or returns NULL otherwise.  */
 689
 690 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 691
 692 /* Create a frame using the specified BASE and PC.  */
 693
 694 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 695
 696 /* FIXME: cagney/2002-12-06: Has the PC in the current frame changed?
 697    "infrun.c", Thanks to gdbarch_decr_pc_after_break, can change the PC after
 698    the initial frame create.  This puts things back in sync.
 699
 700    This replaced: frame->pc = ....; */
 701 extern void deprecated_update_frame_pc_hack (struct frame_info *frame,
 702                                              CORE_ADDR pc);
 703
 704 /* FIXME: cagney/2002-12-18: Has the frame's base changed?  Or to be
 705    more exact, was that initial guess at the frame's base as returned
 706    by the deleted read_fp() wrong?  If it was, fix it.  This shouldn't
 707    be necessary since the code should be getting the frame's base
 708    correct from the outset.
 709
 710    This replaced: frame->frame = ....; */
 711 extern void deprecated_update_frame_base_hack (struct frame_info *frame,
 712                                                CORE_ADDR base);
 713
 714 #endif /* !defined (FRAME_H)  */