gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986, 1988-1994, 1996-2004, 2007-2012 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #if !defined (FRAME_H)
  22 #define FRAME_H 1
  23
  24 /* The following is the intended naming schema for frame functions.
  25    It isn't 100% consistent, but it is aproaching that.  Frame naming
  26    schema:
  27
  28    Prefixes:
  29
  30    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  31    equivalent to THIS->next->unwind->what)
  32
  33    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  34    frame.
  35
  36    frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
  37    real caller.  Any inlined functions in NEXT's stack frame are
  38    skipped.  Use these to ignore any potentially inlined functions,
  39    e.g. inlined into the first instruction of a library trampoline.
  40
  41    get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is
  42    inlined, skip to the containing stack frame.
  43
  44    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  45    invalidate the frame / regcache afterwards) (better name more
  46    strongly hinting at its unsafeness)
  47
  48    safe_....(): Safer version of various functions, doesn't throw an
  49    error (leave this for later?).  Returns non-zero / non-NULL if the
  50    request succeeds, zero / NULL otherwize.
  51
  52    Suffixes:
  53
  54    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  55
  56    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  57    alternative is *frame_unsigned_WHAT).
  58
  59    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  60
  61    What:
  62
  63    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  64    *memory.
  65
  66    /frame/_register* (frame, regnum [, buf]): extract/return register.
  67
  68    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  69    stack *address, ...
  70
  71    */
  72
  73 struct symtab_and_line;
  74 struct frame_unwind;
  75 struct frame_base;
  76 struct block;
  77 struct gdbarch;
  78 struct ui_file;
  79
  80 /* The frame object.  */
  81
  82 struct frame_info;
  83
  84 /* The frame object's ID.  This provides a per-frame unique identifier
  85    that can be used to relocate a `struct frame_info' after a target
  86    resume or a frame cache destruct.  It of course assumes that the
  87    inferior hasn't unwound the stack past that frame.  */
  88
  89 struct frame_id
  90 {
  91   /* The frame's stack address.  This shall be constant through out
  92      the lifetime of a frame.  Note that this requirement applies to
  93      not just the function body, but also the prologue and (in theory
  94      at least) the epilogue.  Since that value needs to fall either on
  95      the boundary, or within the frame's address range, the frame's
  96      outer-most address (the inner-most address of the previous frame)
  97      is used.  Watch out for all the legacy targets that still use the
  98      function pointer register or stack pointer register.  They are
  99      wrong.
 100
 101      This field is valid only if stack_addr_p is true.  Otherwise, this
 102      frame represents the null frame.  */
 103   CORE_ADDR stack_addr;
 104
 105   /* The frame's code address.  This shall be constant through out the
 106      lifetime of the frame.  While the PC (a.k.a. resume address)
 107      changes as the function is executed, this code address cannot.
 108      Typically, it is set to the address of the entry point of the
 109      frame's function (as returned by get_frame_func).
 110
 111      For inlined functions (INLINE_DEPTH != 0), this is the address of
 112      the first executed instruction in the block corresponding to the
 113      inlined function.
 114
 115      This field is valid only if code_addr_p is true.  Otherwise, this
 116      frame is considered to have a wildcard code address, i.e. one that
 117      matches every address value in frame comparisons.  */
 118   CORE_ADDR code_addr;
 119
 120   /* The frame's special address.  This shall be constant through out the
 121      lifetime of the frame.  This is used for architectures that may have
 122      frames that do not change the stack but are still distinct and have
 123      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 124      stack for registers).  This field is treated as unordered - i.e. will
 125      not be used in frame ordering comparisons.
 126
 127      This field is valid only if special_addr_p is true.  Otherwise, this
 128      frame is considered to have a wildcard special address, i.e. one that
 129      matches every address value in frame comparisons.  */
 130   CORE_ADDR special_addr;
 131
 132   /* Flags to indicate the above fields have valid contents.  */
 133   unsigned int stack_addr_p : 1;
 134   unsigned int code_addr_p : 1;
 135   unsigned int special_addr_p : 1;
 136
 137   /* The inline depth of this frame.  A frame representing a "called"
 138      inlined function will have this set to a nonzero value.  */
 139   int inline_depth;
 140 };
 141
 142 /* Methods for constructing and comparing Frame IDs.  */
 143
 144 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 145 extern const struct frame_id null_frame_id;
 146
 147 /* This means "there is no frame ID, but there is a frame".  It should be
 148    replaced by best-effort frame IDs for the outermost frame, somehow.
 149    The implementation is only special_addr_p set.  */
 150 extern const struct frame_id outer_frame_id;
 151
 152 /* Flag to control debugging.  */
 153
 154 extern int frame_debug;
 155
 156 /* Construct a frame ID.  The first parameter is the frame's constant
 157    stack address (typically the outer-bound), and the second the
 158    frame's constant code address (typically the entry point).
 159    The special identifier address is set to indicate a wild card.  */
 160 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 161                                        CORE_ADDR code_addr);
 162
 163 /* Construct a special frame ID.  The first parameter is the frame's constant
 164    stack address (typically the outer-bound), the second is the
 165    frame's constant code address (typically the entry point),
 166    and the third parameter is the frame's special identifier address.  */
 167 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 168                                                CORE_ADDR code_addr,
 169                                                CORE_ADDR special_addr);
 170
 171 /* Construct a wild card frame ID.  The parameter is the frame's constant
 172    stack address (typically the outer-bound).  The code address as well
 173    as the special identifier address are set to indicate wild cards.  */
 174 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 175
 176 /* Returns non-zero when L is a valid frame (a valid frame has a
 177    non-zero .base).  The outermost frame is valid even without an
 178    ID.  */
 179 extern int frame_id_p (struct frame_id l);
 180
 181 /* Returns non-zero when L is a valid frame representing an inlined
 182    function.  */
 183 extern int frame_id_inlined_p (struct frame_id l);
 184
 185 /* Returns non-zero when L and R identify the same frame, or, if
 186    either L or R have a zero .func, then the same frame base.  */
 187 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 188
 189 /* Write the internal representation of a frame ID on the specified
 190    stream.  */
 191 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 192
 193
 194 /* Frame types.  Some are real, some are signal trampolines, and some
 195    are completely artificial (dummy).  */
 196
 197 enum frame_type
 198 {
 199   /* A true stack frame, created by the target program during normal
 200      execution.  */
 201   NORMAL_FRAME,
 202   /* A fake frame, created by GDB when performing an inferior function
 203      call.  */
 204   DUMMY_FRAME,
 205   /* A frame representing an inlined function, associated with an
 206      upcoming (prev, outer, older) NORMAL_FRAME.  */
 207   INLINE_FRAME,
 208   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 209   TAILCALL_FRAME,
 210   /* In a signal handler, various OSs handle this in various ways.
 211      The main thing is that the frame may be far from normal.  */
 212   SIGTRAMP_FRAME,
 213   /* Fake frame representing a cross-architecture call.  */
 214   ARCH_FRAME,
 215   /* Sentinel or registers frame.  This frame obtains register values
 216      direct from the inferior's registers.  */
 217   SENTINEL_FRAME
 218 };
 219
 220 /* For every stopped thread, GDB tracks two frames: current and
 221    selected.  Current frame is the inner most frame of the selected
 222    thread.  Selected frame is the one being examined by the GDB
 223    CLI (selected using `up', `down', ...).  The frames are created
 224    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 225 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 226    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 227    selected frame.  At present GDB only tracks the selected frame of
 228    the current thread.  But be warned, that might change.  */
 229 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 230    and current frame can be active.  Switching threads causes gdb to
 231    discard all that cached frame information.  Ulgh!  Instead, current
 232    and selected frame should be bound to a thread.  */
 233
 234 /* On demand, create the inner most frame using information found in
 235    the inferior.  If the inner most frame can't be created, throw an
 236    error.  */
 237 extern struct frame_info *get_current_frame (void);
 238
 239 /* Does the current target interface have enough state to be able to
 240    query the current inferior for frame info, and is the inferior in a
 241    state where that is possible?  */
 242 extern int has_stack_frames (void);
 243
 244 /* Invalidates the frame cache (this function should have been called
 245    invalidate_cached_frames).
 246
 247    FIXME: cagney/2002-11-28: There should be two methods: one that
 248    reverts the thread's selected frame back to current frame (for when
 249    the inferior resumes) and one that does not (for when the user
 250    modifies the target invalidating the frame cache).  */
 251 extern void reinit_frame_cache (void);
 252
 253 /* On demand, create the selected frame and then return it.  If the
 254    selected frame can not be created, this function prints then throws
 255    an error.  When MESSAGE is non-NULL, use it for the error message,
 256    otherwize use a generic error message.  */
 257 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 258    frame, this function always returns the current (inner most) frame.
 259    It should instead, when a thread has previously had its frame
 260    selected (but not resumed) and the frame cache invalidated, find
 261    and then return that thread's previously selected frame.  */
 262 extern struct frame_info *get_selected_frame (const char *message);
 263
 264 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 265 extern struct frame_info *get_selected_frame_if_set (void);
 266
 267 /* Select a specific frame.  NULL, apparently implies re-select the
 268    inner most frame.  */
 269 extern void select_frame (struct frame_info *);
 270
 271 /* Given a FRAME, return the next (more inner, younger) or previous
 272    (more outer, older) frame.  */
 273 extern struct frame_info *get_prev_frame (struct frame_info *);
 274 extern struct frame_info *get_next_frame (struct frame_info *);
 275
 276 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 277    is not found.  */
 278 extern struct frame_info *frame_find_by_id (struct frame_id id);
 279
 280 /* Base attributes of a frame: */
 281
 282 /* The frame's `resume' address.  Where the program will resume in
 283    this frame.
 284
 285    This replaced: frame->pc; */
 286 extern CORE_ADDR get_frame_pc (struct frame_info *);
 287
 288 /* Same as get_frame_pc, but return a boolean indication of whether
 289    the PC is actually available, instead of throwing an error.  */
 290
 291 extern int get_frame_pc_if_available (struct frame_info *frame,
 292                                       CORE_ADDR *pc);
 293
 294 /* An address (not necessarily aligned to an instruction boundary)
 295    that falls within THIS frame's code block.
 296
 297    When a function call is the last statement in a block, the return
 298    address for the call may land at the start of the next block.
 299    Similarly, if a no-return function call is the last statement in
 300    the function, the return address may end up pointing beyond the
 301    function, and possibly at the start of the next function.
 302
 303    These methods make an allowance for this.  For call frames, this
 304    function returns the frame's PC-1 which "should" be an address in
 305    the frame's block.  */
 306
 307 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 308
 309 /* Same as get_frame_address_in_block, but returns a boolean
 310    indication of whether the frame address is determinable (when the
 311    PC is unavailable, it will not be), instead of possibly throwing an
 312    error trying to read an unavailable PC.  */
 313
 314 extern int
 315   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 316                                            CORE_ADDR *pc);
 317
 318 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 319    known as top-of-stack.  */
 320
 321 extern CORE_ADDR get_frame_sp (struct frame_info *);
 322
 323 /* Following on from the `resume' address.  Return the entry point
 324    address of the function containing that resume address, or zero if
 325    that function isn't known.  */
 326 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 327
 328 /* Same as get_frame_func, but returns a boolean indication of whether
 329    the frame function is determinable (when the PC is unavailable, it
 330    will not be), instead of possibly throwing an error trying to read
 331    an unavailable PC.  */
 332
 333 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 334
 335 /* Closely related to the resume address, various symbol table
 336    attributes that are determined by the PC.  Note that for a normal
 337    frame, the PC refers to the resume address after the return, and
 338    not the call instruction.  In such a case, the address is adjusted
 339    so that it (approximately) identifies the call site (and not the
 340    return site).
 341
 342    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 343    computed value.  Working on the assumption that the bottle-neck is
 344    in the single step code, and that code causes the frame cache to be
 345    constantly flushed, caching things in a frame is probably of little
 346    benefit.  As they say `show us the numbers'.
 347
 348    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 349    find_frame_block(), find_frame_partial_function(),
 350    find_frame_symtab(), find_frame_function().  Each will need to be
 351    carefully considered to determine if the real intent was for it to
 352    apply to the PC or the adjusted PC.  */
 353 extern void find_frame_sal (struct frame_info *frame,
 354                             struct symtab_and_line *sal);
 355
 356 /* Set the current source and line to the location given by frame
 357    FRAME, if possible.  When CENTER is true, adjust so the relevant
 358    line is in the center of the next 'list'.  */
 359
 360 void set_current_sal_from_frame (struct frame_info *, int);
 361
 362 /* Return the frame base (what ever that is) (DEPRECATED).
 363
 364    Old code was trying to use this single method for two conflicting
 365    purposes.  Such code needs to be updated to use either of:
 366
 367    get_frame_id: A low level frame unique identifier, that consists of
 368    both a stack and a function address, that can be used to uniquely
 369    identify a frame.  This value is determined by the frame's
 370    low-level unwinder, the stack part [typically] being the
 371    top-of-stack of the previous frame, and the function part being the
 372    function's start address.  Since the correct identification of a
 373    frameless function requires both a stack and function address,
 374    the old get_frame_base method was not sufficient.
 375
 376    get_frame_base_address: get_frame_locals_address:
 377    get_frame_args_address: A set of high-level debug-info dependant
 378    addresses that fall within the frame.  These addresses almost
 379    certainly will not match the stack address part of a frame ID (as
 380    returned by get_frame_base).
 381
 382    This replaced: frame->frame; */
 383
 384 extern CORE_ADDR get_frame_base (struct frame_info *);
 385
 386 /* Return the per-frame unique identifer.  Can be used to relocate a
 387    frame after a frame cache flush (and other similar operations).  If
 388    FI is NULL, return the null_frame_id.
 389
 390    NOTE: kettenis/20040508: These functions return a structure.  On
 391    platforms where structures are returned in static storage (vax,
 392    m68k), this may trigger compiler bugs in code like:
 393
 394    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 395
 396    where the return value from the first get_frame_id (l) gets
 397    overwritten by the second get_frame_id (r).  Please avoid writing
 398    code like this.  Use code like:
 399
 400    struct frame_id id = get_frame_id (l);
 401    if (frame_id_eq (id, get_frame_id (r)))
 402
 403    instead, since that avoids the bug.  */
 404 extern struct frame_id get_frame_id (struct frame_info *fi);
 405 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 406 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 407
 408 /* Assuming that a frame is `normal', return its base-address, or 0 if
 409    the information isn't available.  NOTE: This address is really only
 410    meaningful to the frame's high-level debug info.  */
 411 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 412
 413 /* Assuming that a frame is `normal', return the base-address of the
 414    local variables, or 0 if the information isn't available.  NOTE:
 415    This address is really only meaningful to the frame's high-level
 416    debug info.  Typically, the argument and locals share a single
 417    base-address.  */
 418 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 419
 420 /* Assuming that a frame is `normal', return the base-address of the
 421    parameter list, or 0 if that information isn't available.  NOTE:
 422    This address is really only meaningful to the frame's high-level
 423    debug info.  Typically, the argument and locals share a single
 424    base-address.  */
 425 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 426
 427 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 428    for an invalid frame).  */
 429 extern int frame_relative_level (struct frame_info *fi);
 430
 431 /* Return the frame's type.  */
 432
 433 extern enum frame_type get_frame_type (struct frame_info *);
 434
 435 /* Return the frame's program space.  */
 436 extern struct program_space *get_frame_program_space (struct frame_info *);
 437
 438 /* Unwind THIS frame's program space from the NEXT frame.  */
 439 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 440
 441 /* Return the frame's address space.  */
 442 extern struct address_space *get_frame_address_space (struct frame_info *);
 443
 444 /* For frames where we can not unwind further, describe why.  */
 445
 446 enum unwind_stop_reason
 447   {
 448 #define SET(name, description) name,
 449 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 450 #define LAST_ENTRY(name) UNWIND_LAST = name,
 451 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 452
 453 #include "unwind_stop_reasons.def"
 454 #undef SET
 455 #undef FIRST_ENTRY
 456 #undef LAST_ENTRY
 457 #undef FIRST_ERROR
 458   };
 459
 460 /* Return the reason why we can't unwind past this frame.  */
 461
 462 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 463
 464 /* Translate a reason code to an informative string.  */
 465
 466 const char *frame_stop_reason_string (enum unwind_stop_reason);
 467
 468 /* Unwind the stack frame so that the value of REGNUM, in the previous
 469    (up, older) frame is returned.  If VALUEP is NULL, don't
 470    fetch/compute the value.  Instead just return the location of the
 471    value.  */
 472 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 473                                    int *optimizedp, int *unavailablep,
 474                                    enum lval_type *lvalp,
 475                                    CORE_ADDR *addrp, int *realnump,
 476                                    gdb_byte *valuep);
 477
 478 /* Fetch a register from this, or unwind a register from the next
 479    frame.  Note that the get_frame methods are wrappers to
 480    frame->next->unwind.  They all [potentially] throw an error if the
 481    fetch fails.  The value methods never return NULL, but usually
 482    do return a lazy value.  */
 483
 484 extern void frame_unwind_register (struct frame_info *frame,
 485                                    int regnum, gdb_byte *buf);
 486 extern void get_frame_register (struct frame_info *frame,
 487                                 int regnum, gdb_byte *buf);
 488
 489 struct value *frame_unwind_register_value (struct frame_info *frame,
 490                                            int regnum);
 491 struct value *get_frame_register_value (struct frame_info *frame,
 492                                         int regnum);
 493
 494 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 495                                              int regnum);
 496 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 497                                           int regnum);
 498 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 499                                                int regnum);
 500 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 501                                              int regnum);
 502
 503 /* Read a register from this, or unwind a register from the next
 504    frame.  Note that the read_frame methods are wrappers to
 505    get_frame_register_value, that do not throw if the result is
 506    optimized out or unavailable.  */
 507
 508 extern int read_frame_register_unsigned (struct frame_info *frame,
 509                                          int regnum, ULONGEST *val);
 510
 511 /* Get the value of the register that belongs to this FRAME.  This
 512    function is a wrapper to the call sequence ``frame_register_unwind
 513    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 514    VALUEP is NULL, the registers value is not fetched/computed.  */
 515
 516 extern void frame_register (struct frame_info *frame, int regnum,
 517                             int *optimizedp, int *unavailablep,
 518                             enum lval_type *lvalp,
 519                             CORE_ADDR *addrp, int *realnump,
 520                             gdb_byte *valuep);
 521
 522 /* The reverse.  Store a register value relative to the specified
 523    frame.  Note: this call makes the frame's state undefined.  The
 524    register and frame caches must be flushed.  */
 525 extern void put_frame_register (struct frame_info *frame, int regnum,
 526                                 const gdb_byte *buf);
 527
 528 /* Read LEN bytes from one or multiple registers starting with REGNUM
 529    in frame FRAME, starting at OFFSET, into BUF.  If the register
 530    contents are optimized out or unavailable, set *OPTIMIZEDP,
 531    *UNAVAILABLEP accordingly.  */
 532 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 533                                      CORE_ADDR offset, int len,
 534                                      gdb_byte *myaddr,
 535                                      int *optimizedp, int *unavailablep);
 536
 537 /* Write LEN bytes to one or multiple registers starting with REGNUM
 538    in frame FRAME, starting at OFFSET, into BUF.  */
 539 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 540                                       CORE_ADDR offset, int len,
 541                                       const gdb_byte *myaddr);
 542
 543 /* Unwind the PC.  Strictly speaking return the resume address of the
 544    calling frame.  For GDB, `pc' is the resume address and not a
 545    specific register.  */
 546
 547 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 548
 549 /* Same as frame_unwind_caller_pc, but returns a boolean indication of
 550    whether the caller PC is determinable (when the PC is unavailable,
 551    it will not be), instead of possibly throwing an error trying to
 552    read unavailable memory or registers.  */
 553
 554 extern int frame_unwind_caller_pc_if_available (struct frame_info *this_frame,
 555                                                 CORE_ADDR *pc);
 556
 557 /* Discard the specified frame.  Restoring the registers to the state
 558    of the caller.  */
 559 extern void frame_pop (struct frame_info *frame);
 560
 561 /* Return memory from the specified frame.  A frame knows its thread /
 562    LWP and hence can find its way down to a target.  The assumption
 563    here is that the current and previous frame share a common address
 564    space.
 565
 566    If the memory read fails, these methods throw an error.
 567
 568    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 569    methods?  That isn't clear.  Can code, for instance, assume that
 570    this and the previous frame's memory or architecture are identical?
 571    If architecture / memory changes are always separated by special
 572    adaptor frames this should be ok.  */
 573
 574 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 575                               gdb_byte *buf, int len);
 576 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 577                                         CORE_ADDR memaddr, int len);
 578 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 579                                            CORE_ADDR memaddr, int len);
 580
 581 /* Same as above, but return non-zero when the entire memory read
 582    succeeds, zero otherwize.  */
 583 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 584                                      CORE_ADDR addr, gdb_byte *buf, int len);
 585
 586 /* Return this frame's architecture.  */
 587 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 588
 589 /* Return the previous frame's architecture.  */
 590 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 591
 592 /* Return the previous frame's architecture, skipping inline functions.  */
 593 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 594
 595
 596 /* Values for the source flag to be used in print_frame_info_base().  */
 597 enum print_what
 598   {
 599     /* Print only the source line, like in stepi.  */
 600     SRC_LINE = -1,
 601     /* Print only the location, i.e. level, address (sometimes)
 602        function, args, file, line, line num.  */
 603     LOCATION,
 604     /* Print both of the above.  */
 605     SRC_AND_LOC,
 606     /* Print location only, but always include the address.  */
 607     LOC_AND_ADDRESS
 608   };
 609
 610 /* Allocate zero initialized memory from the frame cache obstack.
 611    Appendices to the frame info (such as the unwind cache) should
 612    allocate memory using this method.  */
 613
 614 extern void *frame_obstack_zalloc (unsigned long size);
 615 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 616   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 617 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 618   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 619
 620 /* Create a regcache, and copy the frame's registers into it.  */
 621 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 622
 623 extern struct block *get_frame_block (struct frame_info *,
 624                                       CORE_ADDR *addr_in_block);
 625
 626 /* Return the `struct block' that belongs to the selected thread's
 627    selected frame.  If the inferior has no state, return NULL.
 628
 629    NOTE: cagney/2002-11-29:
 630
 631    No state?  Does the inferior have any execution state (a core file
 632    does, an executable does not).  At present the code tests
 633    `target_has_stack' but I'm left wondering if it should test
 634    `target_has_registers' or, even, a merged target_has_state.
 635
 636    Should it look at the most recently specified SAL?  If the target
 637    has no state, should this function try to extract a block from the
 638    most recently selected SAL?  That way `list foo' would give it some
 639    sort of reference point.  Then again, perhaps that would confuse
 640    things.
 641
 642    Calls to this function can be broken down into two categories: Code
 643    that uses the selected block as an additional, but optional, data
 644    point; Code that uses the selected block as a prop, when it should
 645    have the relevant frame/block/pc explicitly passed in.
 646
 647    The latter can be eliminated by correctly parameterizing the code,
 648    the former though is more interesting.  Per the "address" command,
 649    it occurs in the CLI code and makes it possible for commands to
 650    work, even when the inferior has no state.  */
 651
 652 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 653
 654 extern struct symbol *get_frame_function (struct frame_info *);
 655
 656 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 657
 658 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 659
 660 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 661                                         enum print_what print_what);
 662
 663 extern void print_stack_frame (struct frame_info *, int print_level,
 664                                enum print_what print_what);
 665
 666 extern void print_frame_info (struct frame_info *, int print_level,
 667                               enum print_what print_what, int args);
 668
 669 extern struct frame_info *block_innermost_frame (const struct block *);
 670
 671 extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc);
 672
 673 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
 674    function called get_frame_register_p().  This slightly weird (and
 675    older) variant of get_frame_register() returns zero (indicating the
 676    register value is unavailable/invalid) if either: the register
 677    isn't cached; or the register has been optimized out; or the
 678    register contents are unavailable (because they haven't been
 679    collected in a traceframe).  Problem is, neither check is exactly
 680    correct.  A register can't be optimized out (it may not have been
 681    saved as part of a function call); The fact that a register isn't
 682    in the register cache doesn't mean that the register isn't
 683    available (it could have been fetched from memory).  */
 684
 685 extern int frame_register_read (struct frame_info *frame, int regnum,
 686                                 gdb_byte *buf);
 687
 688 /* From stack.c.  */
 689
 690 extern const char print_entry_values_no[];
 691 extern const char print_entry_values_only[];
 692 extern const char print_entry_values_preferred[];
 693 extern const char print_entry_values_if_needed[];
 694 extern const char print_entry_values_both[];
 695 extern const char print_entry_values_compact[];
 696 extern const char print_entry_values_default[];
 697 extern const char *print_entry_values;
 698
 699 /* Inferior function parameter value read in from a frame.  */
 700
 701 struct frame_arg
 702 {
 703   /* Symbol for this parameter used for example for its name.  */
 704   struct symbol *sym;
 705
 706   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 707      ERROR are NULL this parameter's value should not be printed.  */
 708   struct value *val;
 709
 710   /* String containing the error message, it is more usually NULL indicating no
 711      error occured reading this parameter.  */
 712   char *error;
 713
 714   /* One of the print_entry_values_* entries as appropriate specifically for
 715      this frame_arg.  It will be different from print_entry_values.  With
 716      print_entry_values_no this frame_arg should be printed as a normal
 717      parameter.  print_entry_values_only says it should be printed as entry
 718      value parameter.  print_entry_values_compact says it should be printed as
 719      both as a normal parameter and entry values parameter having the same
 720      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 721      (in such case print_entry_values_no and print_entry_values_only is used
 722      for each parameter kind specifically.  */
 723   const char *entry_kind;
 724 };
 725
 726 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 727                             struct frame_arg *argp,
 728                             struct frame_arg *entryargp);
 729
 730 extern void args_info (char *, int);
 731
 732 extern void locals_info (char *, int);
 733
 734 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 735
 736 extern void return_command (char *, int);
 737
 738 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 739    Return a cleanup which should be called if unwinding fails, and
 740    discarded if it succeeds.  */
 741
 742 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 743                                            const struct frame_unwind *unwind);
 744
 745 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 746
 747    You might think that calls to this function can simply be replaced by a
 748    call to get_selected_frame().
 749
 750    Unfortunately, it isn't that easy.
 751
 752    The relevant code needs to be audited to determine if it is
 753    possible (or practical) to instead pass the applicable frame in as a
 754    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 755    the deprecated_selected_frame global, while its replacement,
 756    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 757    The only real exceptions occur at the edge (in the CLI code) where
 758    user commands need to pick up the selected frame before proceeding.
 759
 760    There are also some functions called with a NULL frame meaning either "the
 761    program is not running" or "use the selected frame".
 762
 763    This is important.  GDB is trying to stamp out the hack:
 764
 765    saved_frame = deprecated_safe_get_selected_frame ();
 766    select_frame (...);
 767    hack_using_global_selected_frame ();
 768    select_frame (saved_frame);
 769
 770    Take care!
 771
 772    This function calls get_selected_frame if the inferior should have a
 773    frame, or returns NULL otherwise.  */
 774
 775 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 776
 777 /* Create a frame using the specified BASE and PC.  */
 778
 779 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 780
 781 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 782    otherwise.  */
 783
 784 extern int frame_unwinder_is (struct frame_info *fi,
 785                               const struct frame_unwind *unwinder);
 786
 787 #endif /* !defined (FRAME_H)  */