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, 2010, 2011
   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 (prev, outer, older) NORMAL_FRAME.  */
 208   INLINE_FRAME,
 209   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 210   TAILCALL_FRAME,
 211   /* In a signal handler, various OSs handle this in various ways.
 212      The main thing is that the frame may be far from normal.  */
 213   SIGTRAMP_FRAME,
 214   /* Fake frame representing a cross-architecture call.  */
 215   ARCH_FRAME,
 216   /* Sentinel or registers frame.  This frame obtains register values
 217      direct from the inferior's registers.  */
 218   SENTINEL_FRAME
 219 };
 220
 221 /* For every stopped thread, GDB tracks two frames: current and
 222    selected.  Current frame is the inner most frame of the selected
 223    thread.  Selected frame is the one being examined by the GDB
 224    CLI (selected using `up', `down', ...).  The frames are created
 225    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 226 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 227    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 228    selected frame.  At present GDB only tracks the selected frame of
 229    the current thread.  But be warned, that might change.  */
 230 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 231    and current frame can be active.  Switching threads causes gdb to
 232    discard all that cached frame information.  Ulgh!  Instead, current
 233    and selected frame should be bound to a thread.  */
 234
 235 /* On demand, create the inner most frame using information found in
 236    the inferior.  If the inner most frame can't be created, throw an
 237    error.  */
 238 extern struct frame_info *get_current_frame (void);
 239
 240 /* Does the current target interface have enough state to be able to
 241    query the current inferior for frame info, and is the inferior in a
 242    state where that is possible?  */
 243 extern int has_stack_frames (void);
 244
 245 /* Invalidates the frame cache (this function should have been called
 246    invalidate_cached_frames).
 247
 248    FIXME: cagney/2002-11-28: There should be two methods: one that
 249    reverts the thread's selected frame back to current frame (for when
 250    the inferior resumes) and one that does not (for when the user
 251    modifies the target invalidating the frame cache).  */
 252 extern void reinit_frame_cache (void);
 253
 254 /* On demand, create the selected frame and then return it.  If the
 255    selected frame can not be created, this function prints then throws
 256    an error.  When MESSAGE is non-NULL, use it for the error message,
 257    otherwize use a generic error message.  */
 258 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 259    frame, this function always returns the current (inner most) frame.
 260    It should instead, when a thread has previously had its frame
 261    selected (but not resumed) and the frame cache invalidated, find
 262    and then return that thread's previously selected frame.  */
 263 extern struct frame_info *get_selected_frame (const char *message);
 264
 265 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 266 extern struct frame_info *get_selected_frame_if_set (void);
 267
 268 /* Select a specific frame.  NULL, apparently implies re-select the
 269    inner most frame.  */
 270 extern void select_frame (struct frame_info *);
 271
 272 /* Given a FRAME, return the next (more inner, younger) or previous
 273    (more outer, older) frame.  */
 274 extern struct frame_info *get_prev_frame (struct frame_info *);
 275 extern struct frame_info *get_next_frame (struct frame_info *);
 276
 277 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 278    is not found.  */
 279 extern struct frame_info *frame_find_by_id (struct frame_id id);
 280
 281 /* Base attributes of a frame: */
 282
 283 /* The frame's `resume' address.  Where the program will resume in
 284    this frame.
 285
 286    This replaced: frame->pc; */
 287 extern CORE_ADDR get_frame_pc (struct frame_info *);
 288
 289 /* Same as get_frame_pc, but return a boolean indication of whether
 290    the PC is actually available, instead of throwing an error.  */
 291
 292 extern int get_frame_pc_if_available (struct frame_info *frame,
 293                                       CORE_ADDR *pc);
 294
 295 /* An address (not necessarily aligned to an instruction boundary)
 296    that falls within THIS frame's code block.
 297
 298    When a function call is the last statement in a block, the return
 299    address for the call may land at the start of the next block.
 300    Similarly, if a no-return function call is the last statement in
 301    the function, the return address may end up pointing beyond the
 302    function, and possibly at the start of the next function.
 303
 304    These methods make an allowance for this.  For call frames, this
 305    function returns the frame's PC-1 which "should" be an address in
 306    the frame's block.  */
 307
 308 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 309
 310 /* Same as get_frame_address_in_block, but returns a boolean
 311    indication of whether the frame address is determinable (when the
 312    PC is unavailable, it will not be), instead of possibly throwing an
 313    error trying to read an unavailable PC.  */
 314
 315 extern int
 316   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 317                                            CORE_ADDR *pc);
 318
 319 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 320    known as top-of-stack.  */
 321
 322 extern CORE_ADDR get_frame_sp (struct frame_info *);
 323
 324 /* Following on from the `resume' address.  Return the entry point
 325    address of the function containing that resume address, or zero if
 326    that function isn't known.  */
 327 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 328
 329 /* Same as get_frame_func, but returns a boolean indication of whether
 330    the frame function is determinable (when the PC is unavailable, it
 331    will not be), instead of possibly throwing an error trying to read
 332    an unavailable PC.  */
 333
 334 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 335
 336 /* Closely related to the resume address, various symbol table
 337    attributes that are determined by the PC.  Note that for a normal
 338    frame, the PC refers to the resume address after the return, and
 339    not the call instruction.  In such a case, the address is adjusted
 340    so that it (approximately) identifies the call site (and not the
 341    return site).
 342
 343    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 344    computed value.  Working on the assumption that the bottle-neck is
 345    in the single step code, and that code causes the frame cache to be
 346    constantly flushed, caching things in a frame is probably of little
 347    benefit.  As they say `show us the numbers'.
 348
 349    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 350    find_frame_block(), find_frame_partial_function(),
 351    find_frame_symtab(), find_frame_function().  Each will need to be
 352    carefully considered to determine if the real intent was for it to
 353    apply to the PC or the adjusted PC.  */
 354 extern void find_frame_sal (struct frame_info *frame,
 355                             struct symtab_and_line *sal);
 356
 357 /* Set the current source and line to the location given by frame
 358    FRAME, if possible.  When CENTER is true, adjust so the relevant
 359    line is in the center of the next 'list'.  */
 360
 361 void set_current_sal_from_frame (struct frame_info *, int);
 362
 363 /* Return the frame base (what ever that is) (DEPRECATED).
 364
 365    Old code was trying to use this single method for two conflicting
 366    purposes.  Such code needs to be updated to use either of:
 367
 368    get_frame_id: A low level frame unique identifier, that consists of
 369    both a stack and a function address, that can be used to uniquely
 370    identify a frame.  This value is determined by the frame's
 371    low-level unwinder, the stack part [typically] being the
 372    top-of-stack of the previous frame, and the function part being the
 373    function's start address.  Since the correct identification of a
 374    frameless function requires both a stack and function address,
 375    the old get_frame_base method was not sufficient.
 376
 377    get_frame_base_address: get_frame_locals_address:
 378    get_frame_args_address: A set of high-level debug-info dependant
 379    addresses that fall within the frame.  These addresses almost
 380    certainly will not match the stack address part of a frame ID (as
 381    returned by get_frame_base).
 382
 383    This replaced: frame->frame; */
 384
 385 extern CORE_ADDR get_frame_base (struct frame_info *);
 386
 387 /* Return the per-frame unique identifer.  Can be used to relocate a
 388    frame after a frame cache flush (and other similar operations).  If
 389    FI is NULL, return the null_frame_id.
 390
 391    NOTE: kettenis/20040508: These functions return a structure.  On
 392    platforms where structures are returned in static storage (vax,
 393    m68k), this may trigger compiler bugs in code like:
 394
 395    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 396
 397    where the return value from the first get_frame_id (l) gets
 398    overwritten by the second get_frame_id (r).  Please avoid writing
 399    code like this.  Use code like:
 400
 401    struct frame_id id = get_frame_id (l);
 402    if (frame_id_eq (id, get_frame_id (r)))
 403
 404    instead, since that avoids the bug.  */
 405 extern struct frame_id get_frame_id (struct frame_info *fi);
 406 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 407 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 408
 409 /* Assuming that a frame is `normal', return its base-address, or 0 if
 410    the information isn't available.  NOTE: This address is really only
 411    meaningful to the frame's high-level debug info.  */
 412 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 413
 414 /* Assuming that a frame is `normal', return the base-address of the
 415    local variables, or 0 if the information isn't available.  NOTE:
 416    This address is really only meaningful to the frame's high-level
 417    debug info.  Typically, the argument and locals share a single
 418    base-address.  */
 419 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 420
 421 /* Assuming that a frame is `normal', return the base-address of the
 422    parameter list, or 0 if that information isn't available.  NOTE:
 423    This address is really only meaningful to the frame's high-level
 424    debug info.  Typically, the argument and locals share a single
 425    base-address.  */
 426 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 427
 428 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 429    for an invalid frame).  */
 430 extern int frame_relative_level (struct frame_info *fi);
 431
 432 /* Return the frame's type.  */
 433
 434 extern enum frame_type get_frame_type (struct frame_info *);
 435
 436 /* Return the frame's program space.  */
 437 extern struct program_space *get_frame_program_space (struct frame_info *);
 438
 439 /* Unwind THIS frame's program space from the NEXT frame.  */
 440 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 441
 442 /* Return the frame's address space.  */
 443 extern struct address_space *get_frame_address_space (struct frame_info *);
 444
 445 /* For frames where we can not unwind further, describe why.  */
 446
 447 enum unwind_stop_reason
 448   {
 449     /* No particular reason; either we haven't tried unwinding yet,
 450        or we didn't fail.  */
 451     UNWIND_NO_REASON,
 452
 453     /* The previous frame's analyzer returns an invalid result
 454        from this_id.
 455
 456        FIXME drow/2006-08-16: This is how GDB used to indicate end of
 457        stack.  We should migrate to a model where frames always have a
 458        valid ID, and this becomes not just an error but an internal
 459        error.  But that's a project for another day.  */
 460     UNWIND_NULL_ID,
 461
 462     /* This frame is the outermost.  */
 463     UNWIND_OUTERMOST,
 464
 465     /* All the conditions after this point are considered errors;
 466        abnormal stack termination.  If a backtrace stops for one
 467        of these reasons, we'll let the user know.  This marker
 468        is not a valid stop reason.  */
 469     UNWIND_FIRST_ERROR,
 470
 471     /* Can't unwind further, because that would require knowing the
 472        values of registers or memory that haven't been collected.  */
 473     UNWIND_UNAVAILABLE,
 474
 475     /* This frame ID looks like it ought to belong to a NEXT frame,
 476        but we got it for a PREV frame.  Normally, this is a sign of
 477        unwinder failure.  It could also indicate stack corruption.  */
 478     UNWIND_INNER_ID,
 479
 480     /* This frame has the same ID as the previous one.  That means
 481        that unwinding further would almost certainly give us another
 482        frame with exactly the same ID, so break the chain.  Normally,
 483        this is a sign of unwinder failure.  It could also indicate
 484        stack corruption.  */
 485     UNWIND_SAME_ID,
 486
 487     /* The frame unwinder didn't find any saved PC, but we needed
 488        one to unwind further.  */
 489     UNWIND_NO_SAVED_PC,
 490   };
 491
 492 /* Return the reason why we can't unwind past this frame.  */
 493
 494 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 495
 496 /* Translate a reason code to an informative string.  */
 497
 498 const char *frame_stop_reason_string (enum unwind_stop_reason);
 499
 500 /* Unwind the stack frame so that the value of REGNUM, in the previous
 501    (up, older) frame is returned.  If VALUEP is NULL, don't
 502    fetch/compute the value.  Instead just return the location of the
 503    value.  */
 504 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 505                                    int *optimizedp, int *unavailablep,
 506                                    enum lval_type *lvalp,
 507                                    CORE_ADDR *addrp, int *realnump,
 508                                    gdb_byte *valuep);
 509
 510 /* Fetch a register from this, or unwind a register from the next
 511    frame.  Note that the get_frame methods are wrappers to
 512    frame->next->unwind.  They all [potentially] throw an error if the
 513    fetch fails.  The value methods never return NULL, but usually
 514    do return a lazy value.  */
 515
 516 extern void frame_unwind_register (struct frame_info *frame,
 517                                    int regnum, gdb_byte *buf);
 518 extern void get_frame_register (struct frame_info *frame,
 519                                 int regnum, gdb_byte *buf);
 520
 521 struct value *frame_unwind_register_value (struct frame_info *frame,
 522                                            int regnum);
 523 struct value *get_frame_register_value (struct frame_info *frame,
 524                                         int regnum);
 525
 526 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 527                                              int regnum);
 528 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 529                                           int regnum);
 530 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 531                                                int regnum);
 532 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 533                                              int regnum);
 534
 535
 536 /* Get the value of the register that belongs to this FRAME.  This
 537    function is a wrapper to the call sequence ``frame_register_unwind
 538    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 539    VALUEP is NULL, the registers value is not fetched/computed.  */
 540
 541 extern void frame_register (struct frame_info *frame, int regnum,
 542                             int *optimizedp, int *unavailablep,
 543                             enum lval_type *lvalp,
 544                             CORE_ADDR *addrp, int *realnump,
 545                             gdb_byte *valuep);
 546
 547 /* The reverse.  Store a register value relative to the specified
 548    frame.  Note: this call makes the frame's state undefined.  The
 549    register and frame caches must be flushed.  */
 550 extern void put_frame_register (struct frame_info *frame, int regnum,
 551                                 const gdb_byte *buf);
 552
 553 /* Read LEN bytes from one or multiple registers starting with REGNUM
 554    in frame FRAME, starting at OFFSET, into BUF.  If the register
 555    contents are optimized out or unavailable, set *OPTIMIZEDP,
 556    *UNAVAILABLEP accordingly.  */
 557 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 558                                      CORE_ADDR offset, int len,
 559                                      gdb_byte *myaddr,
 560                                      int *optimizedp, int *unavailablep);
 561
 562 /* Write LEN bytes to one or multiple registers starting with REGNUM
 563    in frame FRAME, starting at OFFSET, into BUF.  */
 564 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 565                                       CORE_ADDR offset, int len,
 566                                       const gdb_byte *myaddr);
 567
 568 /* Unwind the PC.  Strictly speaking return the resume address of the
 569    calling frame.  For GDB, `pc' is the resume address and not a
 570    specific register.  */
 571
 572 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 573
 574 /* Same as frame_unwind_caller_pc, but returns a boolean indication of
 575    whether the caller PC is determinable (when the PC is unavailable,
 576    it will not be), instead of possibly throwing an error trying to
 577    read unavailable memory or registers.  */
 578
 579 extern int frame_unwind_caller_pc_if_available (struct frame_info *this_frame,
 580                                                 CORE_ADDR *pc);
 581
 582 /* Discard the specified frame.  Restoring the registers to the state
 583    of the caller.  */
 584 extern void frame_pop (struct frame_info *frame);
 585
 586 /* Return memory from the specified frame.  A frame knows its thread /
 587    LWP and hence can find its way down to a target.  The assumption
 588    here is that the current and previous frame share a common address
 589    space.
 590
 591    If the memory read fails, these methods throw an error.
 592
 593    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 594    methods?  That isn't clear.  Can code, for instance, assume that
 595    this and the previous frame's memory or architecture are identical?
 596    If architecture / memory changes are always separated by special
 597    adaptor frames this should be ok.  */
 598
 599 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 600                               gdb_byte *buf, int len);
 601 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 602                                         CORE_ADDR memaddr, int len);
 603 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 604                                            CORE_ADDR memaddr, int len);
 605
 606 /* Same as above, but return non-zero when the entire memory read
 607    succeeds, zero otherwize.  */
 608 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 609                                      CORE_ADDR addr, gdb_byte *buf, int len);
 610
 611 /* Return this frame's architecture.  */
 612 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 613
 614 /* Return the previous frame's architecture.  */
 615 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 616
 617 /* Return the previous frame's architecture, skipping inline functions.  */
 618 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 619
 620
 621 /* Values for the source flag to be used in print_frame_info_base().  */
 622 enum print_what
 623   {
 624     /* Print only the source line, like in stepi.  */
 625     SRC_LINE = -1,
 626     /* Print only the location, i.e. level, address (sometimes)
 627        function, args, file, line, line num.  */
 628     LOCATION,
 629     /* Print both of the above.  */
 630     SRC_AND_LOC,
 631     /* Print location only, but always include the address.  */
 632     LOC_AND_ADDRESS
 633   };
 634
 635 /* Allocate zero initialized memory from the frame cache obstack.
 636    Appendices to the frame info (such as the unwind cache) should
 637    allocate memory using this method.  */
 638
 639 extern void *frame_obstack_zalloc (unsigned long size);
 640 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 641   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 642 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 643   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 644
 645 /* Create a regcache, and copy the frame's registers into it.  */
 646 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 647
 648 extern struct block *get_frame_block (struct frame_info *,
 649                                       CORE_ADDR *addr_in_block);
 650
 651 /* Return the `struct block' that belongs to the selected thread's
 652    selected frame.  If the inferior has no state, return NULL.
 653
 654    NOTE: cagney/2002-11-29:
 655
 656    No state?  Does the inferior have any execution state (a core file
 657    does, an executable does not).  At present the code tests
 658    `target_has_stack' but I'm left wondering if it should test
 659    `target_has_registers' or, even, a merged target_has_state.
 660
 661    Should it look at the most recently specified SAL?  If the target
 662    has no state, should this function try to extract a block from the
 663    most recently selected SAL?  That way `list foo' would give it some
 664    sort of reference point.  Then again, perhaps that would confuse
 665    things.
 666
 667    Calls to this function can be broken down into two categories: Code
 668    that uses the selected block as an additional, but optional, data
 669    point; Code that uses the selected block as a prop, when it should
 670    have the relevant frame/block/pc explicitly passed in.
 671
 672    The latter can be eliminated by correctly parameterizing the code,
 673    the former though is more interesting.  Per the "address" command,
 674    it occurs in the CLI code and makes it possible for commands to
 675    work, even when the inferior has no state.  */
 676
 677 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 678
 679 extern struct symbol *get_frame_function (struct frame_info *);
 680
 681 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 682
 683 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 684
 685 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 686                                         enum print_what print_what);
 687
 688 extern void print_stack_frame (struct frame_info *, int print_level,
 689                                enum print_what print_what);
 690
 691 extern void print_frame_info (struct frame_info *, int print_level,
 692                               enum print_what print_what, int args);
 693
 694 extern struct frame_info *block_innermost_frame (struct block *);
 695
 696 extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc);
 697
 698 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 699    function called get_frame_register_p().  This slightly weird (and
 700    older) variant of get_frame_register() returns zero (indicating the
 701    register value is unavailable/invalid) if either: the register
 702    isn't cached; or the register has been optimized out; or the
 703    register contents are unavailable (because they haven't been
 704    collected in a traceframe).  Problem is, neither check is exactly
 705    correct.  A register can't be optimized out (it may not have been
 706    saved as part of a function call); The fact that a register isn't
 707    in the register cache doesn't mean that the register isn't
 708    available (it could have been fetched from memory).  */
 709
 710 extern int frame_register_read (struct frame_info *frame, int regnum,
 711                                 gdb_byte *buf);
 712
 713 /* From stack.c.  */
 714
 715 /* Inferior function parameter value read in from a frame.  */
 716
 717 struct frame_arg
 718 {
 719   /* Symbol for this parameter used for example for its name.  */
 720   struct symbol *sym;
 721
 722   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 723      ERROR are NULL this parameter's value should not be printed.  */
 724   struct value *val;
 725
 726   /* String containing the error message, it is more usually NULL indicating no
 727      error occured reading this parameter.  */
 728   char *error;
 729 };
 730
 731 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 732                             struct frame_arg *argp);
 733
 734 extern void args_info (char *, int);
 735
 736 extern void locals_info (char *, int);
 737
 738 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 739
 740 extern void return_command (char *, int);
 741
 742 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 743    Return a cleanup which should be called if unwinding fails, and
 744    discarded if it succeeds.  */
 745
 746 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 747                                            const struct frame_unwind *unwind);
 748
 749 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 750
 751    You might think that calls to this function can simply be replaced by a
 752    call to get_selected_frame().
 753
 754    Unfortunately, it isn't that easy.
 755
 756    The relevant code needs to be audited to determine if it is
 757    possible (or practical) to instead pass the applicable frame in as a
 758    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 759    the deprecated_selected_frame global, while its replacement,
 760    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 761    The only real exceptions occur at the edge (in the CLI code) where
 762    user commands need to pick up the selected frame before proceeding.
 763
 764    There are also some functions called with a NULL frame meaning either "the
 765    program is not running" or "use the selected frame".
 766
 767    This is important.  GDB is trying to stamp out the hack:
 768
 769    saved_frame = deprecated_safe_get_selected_frame ();
 770    select_frame (...);
 771    hack_using_global_selected_frame ();
 772    select_frame (saved_frame);
 773
 774    Take care!
 775
 776    This function calls get_selected_frame if the inferior should have a
 777    frame, or returns NULL otherwise.  */
 778
 779 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 780
 781 /* Create a frame using the specified BASE and PC.  */
 782
 783 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 784
 785 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 786    otherwise.  */
 787
 788 extern int frame_unwinder_is (struct frame_info *fi,
 789                               const struct frame_unwind *unwinder);
 790
 791 #endif /* !defined (FRAME_H)  */