gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,
   4    1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009
   5    Free Software Foundation, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #if !defined (FRAME_H)
  23 #define FRAME_H 1
  24
  25 /* The following is the intended naming schema for frame functions.
  26    It isn't 100% consistent, but it is aproaching that.  Frame naming
  27    schema:
  28
  29    Prefixes:
  30
  31    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  32    equivalent to THIS->next->unwind->what)
  33
  34    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  35    frame.
  36
  37    frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
  38    real caller.  Any inlined functions in NEXT's stack frame are
  39    skipped.  Use these to ignore any potentially inlined functions,
  40    e.g. inlined into the first instruction of a library trampoline.
  41
  42    get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is
  43    inlined, skip to the containing stack frame.
  44
  45    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  46    invalidate the frame / regcache afterwards) (better name more
  47    strongly hinting at its unsafeness)
  48
  49    safe_....(): Safer version of various functions, doesn't throw an
  50    error (leave this for later?).  Returns non-zero / non-NULL if the
  51    request succeeds, zero / NULL otherwize.
  52
  53    Suffixes:
  54
  55    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  56
  57    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  58    alternative is *frame_unsigned_WHAT).
  59
  60    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  61
  62    What:
  63
  64    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  65    *memory.
  66
  67    /frame/_register* (frame, regnum [, buf]): extract/return register.
  68
  69    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  70    stack *address, ...
  71
  72    */
  73
  74 struct symtab_and_line;
  75 struct frame_unwind;
  76 struct frame_base;
  77 struct block;
  78 struct gdbarch;
  79 struct ui_file;
  80
  81 /* The frame object.  */
  82
  83 struct frame_info;
  84
  85 /* The frame object's ID.  This provides a per-frame unique identifier
  86    that can be used to relocate a `struct frame_info' after a target
  87    resume or a frame cache destruct.  It of course assumes that the
  88    inferior hasn't unwound the stack past that frame.  */
  89
  90 struct frame_id
  91 {
  92   /* The frame's stack address.  This shall be constant through out
  93      the lifetime of a frame.  Note that this requirement applies to
  94      not just the function body, but also the prologue and (in theory
  95      at least) the epilogue.  Since that value needs to fall either on
  96      the boundary, or within the frame's address range, the frame's
  97      outer-most address (the inner-most address of the previous frame)
  98      is used.  Watch out for all the legacy targets that still use the
  99      function pointer register or stack pointer register.  They are
 100      wrong.
 101
 102      This field is valid only if stack_addr_p is true.  Otherwise, this
 103      frame represents the null frame.  */
 104   CORE_ADDR stack_addr;
 105
 106   /* The frame's code address.  This shall be constant through out the
 107      lifetime of the frame.  While the PC (a.k.a. resume address)
 108      changes as the function is executed, this code address cannot.
 109      Typically, it is set to the address of the entry point of the
 110      frame's function (as returned by get_frame_func).
 111
 112      For inlined functions (INLINE_DEPTH != 0), this is the address of
 113      the first executed instruction in the block corresponding to the
 114      inlined function.
 115
 116      This field is valid only if code_addr_p is true.  Otherwise, this
 117      frame is considered to have a wildcard code address, i.e. one that
 118      matches every address value in frame comparisons.  */
 119   CORE_ADDR code_addr;
 120
 121   /* The frame's special address.  This shall be constant through out the
 122      lifetime of the frame.  This is used for architectures that may have
 123      frames that do not change the stack but are still distinct and have
 124      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 125      stack for registers).  This field is treated as unordered - i.e. will
 126      not be used in frame ordering comparisons.
 127
 128      This field is valid only if special_addr_p is true.  Otherwise, this
 129      frame is considered to have a wildcard special address, i.e. one that
 130      matches every address value in frame comparisons.  */
 131   CORE_ADDR special_addr;
 132
 133   /* Flags to indicate the above fields have valid contents.  */
 134   unsigned int stack_addr_p : 1;
 135   unsigned int code_addr_p : 1;
 136   unsigned int special_addr_p : 1;
 137
 138   /* The inline depth of this frame.  A frame representing a "called"
 139      inlined function will have this set to a nonzero value.  */
 140   int inline_depth;
 141 };
 142
 143 /* Methods for constructing and comparing Frame IDs.  */
 144
 145 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 146 extern const struct frame_id null_frame_id;
 147
 148 /* This means "there is no frame ID, but there is a frame".  It should be
 149    replaced by best-effort frame IDs for the outermost frame, somehow.
 150    The implementation is only special_addr_p set.  */
 151 extern const struct frame_id outer_frame_id;
 152
 153 /* Flag to control debugging.  */
 154
 155 extern int frame_debug;
 156
 157 /* Construct a frame ID.  The first parameter is the frame's constant
 158    stack address (typically the outer-bound), and the second the
 159    frame's constant code address (typically the entry point).
 160    The special identifier address is set to indicate a wild card.  */
 161 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 162                                        CORE_ADDR code_addr);
 163
 164 /* Construct a special frame ID.  The first parameter is the frame's constant
 165    stack address (typically the outer-bound), the second is the
 166    frame's constant code address (typically the entry point),
 167    and the third parameter is the frame's special identifier address. */
 168 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 169                                                CORE_ADDR code_addr,
 170                                                CORE_ADDR special_addr);
 171
 172 /* Construct a wild card frame ID.  The parameter is the frame's constant
 173    stack address (typically the outer-bound).  The code address as well
 174    as the special identifier address are set to indicate wild cards.  */
 175 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 176
 177 /* Returns non-zero when L is a valid frame (a valid frame has a
 178    non-zero .base).  The outermost frame is valid even without an
 179    ID.  */
 180 extern int frame_id_p (struct frame_id l);
 181
 182 /* Returns non-zero when L is a valid frame representing an inlined
 183    function.  */
 184 extern int frame_id_inlined_p (struct frame_id l);
 185
 186 /* Returns non-zero when L and R identify the same frame, or, if
 187    either L or R have a zero .func, then the same frame base.  */
 188 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 189
 190 /* Write the internal representation of a frame ID on the specified
 191    stream.  */
 192 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 193
 194
 195 /* Frame types.  Some are real, some are signal trampolines, and some
 196    are completely artificial (dummy).  */
 197
 198 enum frame_type
 199 {
 200   /* A true stack frame, created by the target program during normal
 201      execution.  */
 202   NORMAL_FRAME,
 203   /* A fake frame, created by GDB when performing an inferior function
 204      call.  */
 205   DUMMY_FRAME,
 206   /* A frame representing an inlined function, associated with an
 207      upcoming (next, inner, younger) NORMAL_FRAME.  */
 208   INLINE_FRAME,
 209   /* In a signal handler, various OSs handle this in various ways.
 210      The main thing is that the frame may be far from normal.  */
 211   SIGTRAMP_FRAME,
 212   /* Fake frame representing a cross-architecture call.  */
 213   ARCH_FRAME,
 214   /* Sentinel or registers frame.  This frame obtains register values
 215      direct from the inferior's registers.  */
 216   SENTINEL_FRAME
 217 };
 218
 219 /* For every stopped thread, GDB tracks two frames: current and
 220    selected.  Current frame is the inner most frame of the selected
 221    thread.  Selected frame is the one being examined by the the GDB
 222    CLI (selected using `up', `down', ...).  The frames are created
 223    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 224 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 225    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 226    selected frame.  At present GDB only tracks the selected frame of
 227    the current thread.  But be warned, that might change.  */
 228 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 229    and current frame can be active.  Switching threads causes gdb to
 230    discard all that cached frame information.  Ulgh!  Instead, current
 231    and selected frame should be bound to a thread.  */
 232
 233 /* On demand, create the inner most frame using information found in
 234    the inferior.  If the inner most frame can't be created, throw an
 235    error.  */
 236 extern struct frame_info *get_current_frame (void);
 237
 238 /* Does the current target interface have enough state to be able to
 239    query the current inferior for frame info, and is the inferior in a
 240    state where that is possible?  */
 241 extern int has_stack_frames (void);
 242
 243 /* Invalidates the frame cache (this function should have been called
 244    invalidate_cached_frames).
 245
 246    FIXME: cagney/2002-11-28: There should be two methods: one that
 247    reverts the thread's selected frame back to current frame (for when
 248    the inferior resumes) and one that does not (for when the user
 249    modifies the target invalidating the frame cache).  */
 250 extern void reinit_frame_cache (void);
 251
 252 /* On demand, create the selected frame and then return it.  If the
 253    selected frame can not be created, this function prints then throws
 254    an error.  When MESSAGE is non-NULL, use it for the error message,
 255    otherwize use a generic error message.  */
 256 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 257    frame, this function always returns the current (inner most) frame.
 258    It should instead, when a thread has previously had its frame
 259    selected (but not resumed) and the frame cache invalidated, find
 260    and then return that thread's previously selected frame.  */
 261 extern struct frame_info *get_selected_frame (const char *message);
 262
 263 /* Select a specific frame.  NULL, apparently implies re-select the
 264    inner most frame.  */
 265 extern void select_frame (struct frame_info *);
 266
 267 /* Given a FRAME, return the next (more inner, younger) or previous
 268    (more outer, older) frame.  */
 269 extern struct frame_info *get_prev_frame (struct frame_info *);
 270 extern struct frame_info *get_next_frame (struct frame_info *);
 271
 272 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 273    is not found.  */
 274 extern struct frame_info *frame_find_by_id (struct frame_id id);
 275
 276 /* Base attributes of a frame: */
 277
 278 /* The frame's `resume' address.  Where the program will resume in
 279    this frame.
 280
 281    This replaced: frame->pc; */
 282 extern CORE_ADDR get_frame_pc (struct frame_info *);
 283
 284 /* An address (not necessarily aligned to an instruction boundary)
 285    that falls within THIS frame's code block.
 286
 287    When a function call is the last statement in a block, the return
 288    address for the call may land at the start of the next block.
 289    Similarly, if a no-return function call is the last statement in
 290    the function, the return address may end up pointing beyond the
 291    function, and possibly at the start of the next function.
 292
 293    These methods make an allowance for this.  For call frames, this
 294    function returns the frame's PC-1 which "should" be an address in
 295    the frame's block.  */
 296
 297 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 298
 299 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 300    known as top-of-stack.  */
 301
 302 extern CORE_ADDR get_frame_sp (struct frame_info *);
 303
 304 /* Following on from the `resume' address.  Return the entry point
 305    address of the function containing that resume address, or zero if
 306    that function isn't known.  */
 307 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 308
 309 /* Closely related to the resume address, various symbol table
 310    attributes that are determined by the PC.  Note that for a normal
 311    frame, the PC refers to the resume address after the return, and
 312    not the call instruction.  In such a case, the address is adjusted
 313    so that it (approximately) identifies the call site (and not the
 314    return site).
 315
 316    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 317    computed value.  Working on the assumption that the bottle-neck is
 318    in the single step code, and that code causes the frame cache to be
 319    constantly flushed, caching things in a frame is probably of little
 320    benefit.  As they say `show us the numbers'.
 321
 322    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 323    find_frame_block(), find_frame_partial_function(),
 324    find_frame_symtab(), find_frame_function().  Each will need to be
 325    carefully considered to determine if the real intent was for it to
 326    apply to the PC or the adjusted PC.  */
 327 extern void find_frame_sal (struct frame_info *frame,
 328                             struct symtab_and_line *sal);
 329
 330 /* Set the current source and line to the location given by frame
 331    FRAME, if possible.  When CENTER is true, adjust so the relevant
 332    line is in the center of the next 'list'.  */
 333
 334 void set_current_sal_from_frame (struct frame_info *, int);
 335
 336 /* Return the frame base (what ever that is) (DEPRECATED).
 337
 338    Old code was trying to use this single method for two conflicting
 339    purposes.  Such code needs to be updated to use either of:
 340
 341    get_frame_id: A low level frame unique identifier, that consists of
 342    both a stack and a function address, that can be used to uniquely
 343    identify a frame.  This value is determined by the frame's
 344    low-level unwinder, the stack part [typically] being the
 345    top-of-stack of the previous frame, and the function part being the
 346    function's start address.  Since the correct identification of a
 347    frameless function requires both the a stack and function address,
 348    the old get_frame_base method was not sufficient.
 349
 350    get_frame_base_address: get_frame_locals_address:
 351    get_frame_args_address: A set of high-level debug-info dependant
 352    addresses that fall within the frame.  These addresses almost
 353    certainly will not match the stack address part of a frame ID (as
 354    returned by get_frame_base).
 355
 356    This replaced: frame->frame; */
 357
 358 extern CORE_ADDR get_frame_base (struct frame_info *);
 359
 360 /* Return the per-frame unique identifer.  Can be used to relocate a
 361    frame after a frame cache flush (and other similar operations).  If
 362    FI is NULL, return the null_frame_id.
 363
 364    NOTE: kettenis/20040508: These functions return a structure.  On
 365    platforms where structures are returned in static storage (vax,
 366    m68k), this may trigger compiler bugs in code like:
 367
 368    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 369
 370    where the return value from the first get_frame_id (l) gets
 371    overwritten by the second get_frame_id (r).  Please avoid writing
 372    code like this.  Use code like:
 373
 374    struct frame_id id = get_frame_id (l);
 375    if (frame_id_eq (id, get_frame_id (r)))
 376
 377    instead, since that avoids the bug.  */
 378 extern struct frame_id get_frame_id (struct frame_info *fi);
 379 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 380 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 381
 382 /* Assuming that a frame is `normal', return its base-address, or 0 if
 383    the information isn't available.  NOTE: This address is really only
 384    meaningful to the frame's high-level debug info.  */
 385 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 386
 387 /* Assuming that a frame is `normal', return the base-address of the
 388    local variables, or 0 if the 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_locals_address (struct frame_info *);
 393
 394 /* Assuming that a frame is `normal', return the base-address of the
 395    parameter list, or 0 if that information isn't available.  NOTE:
 396    This address is really only meaningful to the frame's high-level
 397    debug info.  Typically, the argument and locals share a single
 398    base-address.  */
 399 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 400
 401 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 402    for an invalid frame).  */
 403 extern int frame_relative_level (struct frame_info *fi);
 404
 405 /* Return the frame's type.  */
 406
 407 extern enum frame_type get_frame_type (struct frame_info *);
 408
 409 /* For frames where we can not unwind further, describe why.  */
 410
 411 enum unwind_stop_reason
 412   {
 413     /* No particular reason; either we haven't tried unwinding yet,
 414        or we didn't fail.  */
 415     UNWIND_NO_REASON,
 416
 417     /* The previous frame's analyzer returns an invalid result
 418        from this_id.
 419
 420        FIXME drow/2006-08-16: This is how GDB used to indicate end of
 421        stack.  We should migrate to a model where frames always have a
 422        valid ID, and this becomes not just an error but an internal
 423        error.  But that's a project for another day.  */
 424     UNWIND_NULL_ID,
 425
 426     /* All the conditions after this point are considered errors;
 427        abnormal stack termination.  If a backtrace stops for one
 428        of these reasons, we'll let the user know.  This marker
 429        is not a valid stop reason.  */
 430     UNWIND_FIRST_ERROR,
 431
 432     /* This frame ID looks like it ought to belong to a NEXT frame,
 433        but we got it for a PREV frame.  Normally, this is a sign of
 434        unwinder failure.  It could also indicate stack corruption.  */
 435     UNWIND_INNER_ID,
 436
 437     /* This frame has the same ID as the previous one.  That means
 438        that unwinding further would almost certainly give us another
 439        frame with exactly the same ID, so break the chain.  Normally,
 440        this is a sign of unwinder failure.  It could also indicate
 441        stack corruption.  */
 442     UNWIND_SAME_ID,
 443
 444     /* The frame unwinder didn't find any saved PC, but we needed
 445        one to unwind further.  */
 446     UNWIND_NO_SAVED_PC,
 447   };
 448
 449 /* Return the reason why we can't unwind past this frame.  */
 450
 451 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 452
 453 /* Translate a reason code to an informative string.  */
 454
 455 const char *frame_stop_reason_string (enum unwind_stop_reason);
 456
 457 /* Unwind the stack frame so that the value of REGNUM, in the previous
 458    (up, older) frame is returned.  If VALUEP is NULL, don't
 459    fetch/compute the value.  Instead just return the location of the
 460    value.  */
 461 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 462                                    int *optimizedp, enum lval_type *lvalp,
 463                                    CORE_ADDR *addrp, int *realnump,
 464                                    gdb_byte *valuep);
 465
 466 /* Fetch a register from this, or unwind a register from the next
 467    frame.  Note that the get_frame methods are wrappers to
 468    frame->next->unwind.  They all [potentially] throw an error if the
 469    fetch fails.  The value methods never return NULL, but usually
 470    do return a lazy value.  */
 471
 472 extern void frame_unwind_register (struct frame_info *frame,
 473                                    int regnum, gdb_byte *buf);
 474 extern void get_frame_register (struct frame_info *frame,
 475                                 int regnum, gdb_byte *buf);
 476
 477 struct value *frame_unwind_register_value (struct frame_info *frame,
 478                                            int regnum);
 479 struct value *get_frame_register_value (struct frame_info *frame,
 480                                         int regnum);
 481
 482 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 483                                              int regnum);
 484 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 485                                           int regnum);
 486 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 487                                                int regnum);
 488 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 489                                              int regnum);
 490
 491
 492 /* Get the value of the register that belongs to this FRAME.  This
 493    function is a wrapper to the call sequence ``frame_register_unwind
 494    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 495    VALUEP is NULL, the registers value is not fetched/computed.  */
 496
 497 extern void frame_register (struct frame_info *frame, int regnum,
 498                             int *optimizedp, enum lval_type *lvalp,
 499                             CORE_ADDR *addrp, int *realnump,
 500                             gdb_byte *valuep);
 501
 502 /* The reverse.  Store a register value relative to the specified
 503    frame.  Note: this call makes the frame's state undefined.  The
 504    register and frame caches must be flushed.  */
 505 extern void put_frame_register (struct frame_info *frame, int regnum,
 506                                 const gdb_byte *buf);
 507
 508 /* Read LEN bytes from one or multiple registers starting with REGNUM
 509    in frame FRAME, starting at OFFSET, into BUF.  */
 510 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 511                                      CORE_ADDR offset, int len,
 512                                      gdb_byte *myaddr);
 513
 514 /* Write LEN bytes to one or multiple registers starting with REGNUM
 515    in frame FRAME, starting at OFFSET, into BUF.  */
 516 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 517                                       CORE_ADDR offset, int len,
 518                                       const gdb_byte *myaddr);
 519
 520 /* Unwind the PC.  Strictly speaking return the resume address of the
 521    calling frame.  For GDB, `pc' is the resume address and not a
 522    specific register.  */
 523
 524 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 525
 526 /* Discard the specified frame.  Restoring the registers to the state
 527    of the caller.  */
 528 extern void frame_pop (struct frame_info *frame);
 529
 530 /* Return memory from the specified frame.  A frame knows its thread /
 531    LWP and hence can find its way down to a target.  The assumption
 532    here is that the current and previous frame share a common address
 533    space.
 534
 535    If the memory read fails, these methods throw an error.
 536
 537    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 538    methods?  That isn't clear.  Can code, for instance, assume that
 539    this and the previous frame's memory or architecture are identical?
 540    If architecture / memory changes are always separated by special
 541    adaptor frames this should be ok.  */
 542
 543 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 544                               gdb_byte *buf, int len);
 545 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 546                                         CORE_ADDR memaddr, int len);
 547 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 548                                            CORE_ADDR memaddr, int len);
 549
 550 /* Same as above, but return non-zero when the entire memory read
 551    succeeds, zero otherwize.  */
 552 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 553                                      CORE_ADDR addr, gdb_byte *buf, int len);
 554
 555 /* Return this frame's architecture.  */
 556 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 557
 558 /* Return the previous frame's architecture.  */
 559 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 560
 561 /* Return the previous frame's architecture, skipping inline functions.  */
 562 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 563
 564
 565 /* Values for the source flag to be used in print_frame_info_base().  */
 566 enum print_what
 567   {
 568     /* Print only the source line, like in stepi. */
 569     SRC_LINE = -1,
 570     /* Print only the location, i.e. level, address (sometimes)
 571        function, args, file, line, line num. */
 572     LOCATION,
 573     /* Print both of the above. */
 574     SRC_AND_LOC,
 575     /* Print location only, but always include the address. */
 576     LOC_AND_ADDRESS
 577   };
 578
 579 /* Allocate zero initialized memory from the frame cache obstack.
 580    Appendices to the frame info (such as the unwind cache) should
 581    allocate memory using this method.  */
 582
 583 extern void *frame_obstack_zalloc (unsigned long size);
 584 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 585 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 586
 587 /* Create a regcache, and copy the frame's registers into it.  */
 588 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 589
 590 extern struct block *get_frame_block (struct frame_info *,
 591                                       CORE_ADDR *addr_in_block);
 592
 593 /* Return the `struct block' that belongs to the selected thread's
 594    selected frame.  If the inferior has no state, return NULL.
 595
 596    NOTE: cagney/2002-11-29:
 597
 598    No state?  Does the inferior have any execution state (a core file
 599    does, an executable does not).  At present the code tests
 600    `target_has_stack' but I'm left wondering if it should test
 601    `target_has_registers' or, even, a merged target_has_state.
 602
 603    Should it look at the most recently specified SAL?  If the target
 604    has no state, should this function try to extract a block from the
 605    most recently selected SAL?  That way `list foo' would give it some
 606    sort of reference point.  Then again, perhaps that would confuse
 607    things.
 608
 609    Calls to this function can be broken down into two categories: Code
 610    that uses the selected block as an additional, but optional, data
 611    point; Code that uses the selected block as a prop, when it should
 612    have the relevant frame/block/pc explicitly passed in.
 613
 614    The latter can be eliminated by correctly parameterizing the code,
 615    the former though is more interesting.  Per the "address" command,
 616    it occurs in the CLI code and makes it possible for commands to
 617    work, even when the inferior has no state.  */
 618
 619 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 620
 621 extern struct symbol *get_frame_function (struct frame_info *);
 622
 623 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 624
 625 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 626
 627 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 628                                         enum print_what print_what);
 629
 630 extern void print_stack_frame (struct frame_info *, int print_level,
 631                                enum print_what print_what);
 632
 633 extern void print_frame_info (struct frame_info *, int print_level,
 634                               enum print_what print_what, int args);
 635
 636 extern struct frame_info *block_innermost_frame (struct block *);
 637
 638 extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc);
 639
 640 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 641    function called get_frame_register_p().  This slightly weird (and
 642    older) variant of get_frame_register() returns zero (indicating the
 643    register is unavailable) if either: the register isn't cached; or
 644    the register has been optimized out.  Problem is, neither check is
 645    exactly correct.  A register can't be optimized out (it may not
 646    have been saved as part of a function call); The fact that a
 647    register isn't in the register cache doesn't mean that the register
 648    isn't available (it could have been fetched from memory).  */
 649
 650 extern int frame_register_read (struct frame_info *frame, int regnum,
 651                                 gdb_byte *buf);
 652
 653 /* From stack.c.  */
 654 extern void args_info (char *, int);
 655
 656 extern void locals_info (char *, int);
 657
 658 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 659
 660 extern void return_command (char *, int);
 661
 662 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 663    Return a cleanup which should be called if unwinding fails, and
 664    discarded if it succeeds.  */
 665
 666 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 667                                            const struct frame_unwind *unwind);
 668
 669 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 670
 671    You might think that calls to this function can simply be replaced by a
 672    call to get_selected_frame().
 673
 674    Unfortunately, it isn't that easy.
 675
 676    The relevant code needs to be audited to determine if it is
 677    possible (or practical) to instead pass the applicable frame in as a
 678    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 679    the deprecated_selected_frame global, while its replacement,
 680    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 681    The only real exceptions occur at the edge (in the CLI code) where
 682    user commands need to pick up the selected frame before proceeding.
 683
 684    There are also some functions called with a NULL frame meaning either "the
 685    program is not running" or "use the selected frame".
 686
 687    This is important.  GDB is trying to stamp out the hack:
 688
 689    saved_frame = deprecated_safe_get_selected_frame ();
 690    select_frame (...);
 691    hack_using_global_selected_frame ();
 692    select_frame (saved_frame);
 693
 694    Take care!
 695
 696    This function calls get_selected_frame if the inferior should have a
 697    frame, or returns NULL otherwise.  */
 698
 699 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 700
 701 /* Create a frame using the specified BASE and PC.  */
 702
 703 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 704
 705 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 706    otherwise.  */
 707
 708 extern int frame_unwinder_is (struct frame_info *fi,
 709                               const struct frame_unwind *unwinder);
 710
 711 #endif /* !defined (FRAME_H)  */