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