gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2013 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (FRAME_H)
  21 #define FRAME_H 1
  22
  23 /* The following is the intended naming schema for frame functions.
  24    It isn't 100% consistent, but it is aproaching that.  Frame naming
  25    schema:
  26
  27    Prefixes:
  28
  29    get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
  30    equivalent to THIS->next->unwind->what)
  31
  32    frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
  33    frame.
  34
  35    frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
  36    real caller.  Any inlined functions in NEXT's stack frame are
  37    skipped.  Use these to ignore any potentially inlined functions,
  38    e.g. inlined into the first instruction of a library trampoline.
  39
  40    get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is
  41    inlined, skip to the containing stack frame.
  42
  43    put_frame_WHAT...(): Put a value into this frame (unsafe, need to
  44    invalidate the frame / regcache afterwards) (better name more
  45    strongly hinting at its unsafeness)
  46
  47    safe_....(): Safer version of various functions, doesn't throw an
  48    error (leave this for later?).  Returns non-zero / non-NULL if the
  49    request succeeds, zero / NULL otherwize.
  50
  51    Suffixes:
  52
  53    void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
  54
  55    ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
  56    alternative is *frame_unsigned_WHAT).
  57
  58    LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
  59
  60    What:
  61
  62    /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
  63    *memory.
  64
  65    /frame/_register* (frame, regnum [, buf]): extract/return register.
  66
  67    CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
  68    stack *address, ...
  69
  70    */
  71
  72 struct symtab_and_line;
  73 struct frame_unwind;
  74 struct frame_base;
  75 struct block;
  76 struct gdbarch;
  77 struct ui_file;
  78
  79 /* The frame object.  */
  80
  81 struct frame_info;
  82
  83 /* The frame object's ID.  This provides a per-frame unique identifier
  84    that can be used to relocate a `struct frame_info' after a target
  85    resume or a frame cache destruct.  It of course assumes that the
  86    inferior hasn't unwound the stack past that frame.  */
  87
  88 struct frame_id
  89 {
  90   /* The frame's stack address.  This shall be constant through out
  91      the lifetime of a frame.  Note that this requirement applies to
  92      not just the function body, but also the prologue and (in theory
  93      at least) the epilogue.  Since that value needs to fall either on
  94      the boundary, or within the frame's address range, the frame's
  95      outer-most address (the inner-most address of the previous frame)
  96      is used.  Watch out for all the legacy targets that still use the
  97      function pointer register or stack pointer register.  They are
  98      wrong.
  99
 100      This field is valid only if stack_addr_p is true.  Otherwise, this
 101      frame represents the null frame.  */
 102   CORE_ADDR stack_addr;
 103
 104   /* The frame's code address.  This shall be constant through out the
 105      lifetime of the frame.  While the PC (a.k.a. resume address)
 106      changes as the function is executed, this code address cannot.
 107      Typically, it is set to the address of the entry point of the
 108      frame's function (as returned by get_frame_func).
 109
 110      For inlined functions (INLINE_DEPTH != 0), this is the address of
 111      the first executed instruction in the block corresponding to the
 112      inlined function.
 113
 114      This field is valid only if code_addr_p is true.  Otherwise, this
 115      frame is considered to have a wildcard code address, i.e. one that
 116      matches every address value in frame comparisons.  */
 117   CORE_ADDR code_addr;
 118
 119   /* The frame's special address.  This shall be constant through out the
 120      lifetime of the frame.  This is used for architectures that may have
 121      frames that do not change the stack but are still distinct and have
 122      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 123      stack for registers).  This field is treated as unordered - i.e. will
 124      not be used in frame ordering comparisons.
 125
 126      This field is valid only if special_addr_p is true.  Otherwise, this
 127      frame is considered to have a wildcard special address, i.e. one that
 128      matches every address value in frame comparisons.  */
 129   CORE_ADDR special_addr;
 130
 131   /* Flags to indicate the above fields have valid contents.  */
 132   unsigned int stack_addr_p : 1;
 133   unsigned int code_addr_p : 1;
 134   unsigned int special_addr_p : 1;
 135
 136   /* It is non-zero for a frame made up by GDB without stack data
 137      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 138      Caller of inlined function will have it zero, each more inner called frame
 139      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 140   int artificial_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 unsigned 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 a frame made up by GDB
 183    without stack data representation in inferior, such as INLINE_FRAME or
 184    TAILCALL_FRAME.  */
 185 extern int frame_id_artificial_p (struct frame_id l);
 186
 187 /* Returns non-zero when L and R identify the same frame, or, if
 188    either L or R have a zero .func, then the same frame base.  */
 189 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 190
 191 /* Write the internal representation of a frame ID on the specified
 192    stream.  */
 193 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 194
 195
 196 /* Frame types.  Some are real, some are signal trampolines, and some
 197    are completely artificial (dummy).  */
 198
 199 enum frame_type
 200 {
 201   /* A true stack frame, created by the target program during normal
 202      execution.  */
 203   NORMAL_FRAME,
 204   /* A fake frame, created by GDB when performing an inferior function
 205      call.  */
 206   DUMMY_FRAME,
 207   /* A frame representing an inlined function, associated with an
 208      upcoming (prev, outer, older) NORMAL_FRAME.  */
 209   INLINE_FRAME,
 210   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 211   TAILCALL_FRAME,
 212   /* In a signal handler, various OSs handle this in various ways.
 213      The main thing is that the frame may be far from normal.  */
 214   SIGTRAMP_FRAME,
 215   /* Fake frame representing a cross-architecture call.  */
 216   ARCH_FRAME,
 217   /* Sentinel or registers frame.  This frame obtains register values
 218      direct from the inferior's registers.  */
 219   SENTINEL_FRAME
 220 };
 221
 222 /* For every stopped thread, GDB tracks two frames: current and
 223    selected.  Current frame is the inner most frame of the selected
 224    thread.  Selected frame is the one being examined by the GDB
 225    CLI (selected using `up', `down', ...).  The frames are created
 226    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 227 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 228    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 229    selected frame.  At present GDB only tracks the selected frame of
 230    the current thread.  But be warned, that might change.  */
 231 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 232    and current frame can be active.  Switching threads causes gdb to
 233    discard all that cached frame information.  Ulgh!  Instead, current
 234    and selected frame should be bound to a thread.  */
 235
 236 /* On demand, create the inner most frame using information found in
 237    the inferior.  If the inner most frame can't be created, throw an
 238    error.  */
 239 extern struct frame_info *get_current_frame (void);
 240
 241 /* Does the current target interface have enough state to be able to
 242    query the current inferior for frame info, and is the inferior in a
 243    state where that is possible?  */
 244 extern int has_stack_frames (void);
 245
 246 /* Invalidates the frame cache (this function should have been called
 247    invalidate_cached_frames).
 248
 249    FIXME: cagney/2002-11-28: There should be two methods: one that
 250    reverts the thread's selected frame back to current frame (for when
 251    the inferior resumes) and one that does not (for when the user
 252    modifies the target invalidating the frame cache).  */
 253 extern void reinit_frame_cache (void);
 254
 255 /* On demand, create the selected frame and then return it.  If the
 256    selected frame can not be created, this function prints then throws
 257    an error.  When MESSAGE is non-NULL, use it for the error message,
 258    otherwize use a generic error message.  */
 259 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 260    frame, this function always returns the current (inner most) frame.
 261    It should instead, when a thread has previously had its frame
 262    selected (but not resumed) and the frame cache invalidated, find
 263    and then return that thread's previously selected frame.  */
 264 extern struct frame_info *get_selected_frame (const char *message);
 265
 266 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 267 extern struct frame_info *get_selected_frame_if_set (void);
 268
 269 /* Select a specific frame.  NULL, apparently implies re-select the
 270    inner most frame.  */
 271 extern void select_frame (struct frame_info *);
 272
 273 /* Given a FRAME, return the next (more inner, younger) or previous
 274    (more outer, older) frame.  */
 275 extern struct frame_info *get_prev_frame (struct frame_info *);
 276 extern struct frame_info *get_next_frame (struct frame_info *);
 277
 278 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 279    is not found.  */
 280 extern struct frame_info *frame_find_by_id (struct frame_id id);
 281
 282 /* Base attributes of a frame: */
 283
 284 /* The frame's `resume' address.  Where the program will resume in
 285    this frame.
 286
 287    This replaced: frame->pc; */
 288 extern CORE_ADDR get_frame_pc (struct frame_info *);
 289
 290 /* Same as get_frame_pc, but return a boolean indication of whether
 291    the PC is actually available, instead of throwing an error.  */
 292
 293 extern int get_frame_pc_if_available (struct frame_info *frame,
 294                                       CORE_ADDR *pc);
 295
 296 /* An address (not necessarily aligned to an instruction boundary)
 297    that falls within THIS frame's code block.
 298
 299    When a function call is the last statement in a block, the return
 300    address for the call may land at the start of the next block.
 301    Similarly, if a no-return function call is the last statement in
 302    the function, the return address may end up pointing beyond the
 303    function, and possibly at the start of the next function.
 304
 305    These methods make an allowance for this.  For call frames, this
 306    function returns the frame's PC-1 which "should" be an address in
 307    the frame's block.  */
 308
 309 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 310
 311 /* Same as get_frame_address_in_block, but returns a boolean
 312    indication of whether the frame address is determinable (when the
 313    PC is unavailable, it will not be), instead of possibly throwing an
 314    error trying to read an unavailable PC.  */
 315
 316 extern int
 317   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 318                                            CORE_ADDR *pc);
 319
 320 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 321    known as top-of-stack.  */
 322
 323 extern CORE_ADDR get_frame_sp (struct frame_info *);
 324
 325 /* Following on from the `resume' address.  Return the entry point
 326    address of the function containing that resume address, or zero if
 327    that function isn't known.  */
 328 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 329
 330 /* Same as get_frame_func, but returns a boolean indication of whether
 331    the frame function is determinable (when the PC is unavailable, it
 332    will not be), instead of possibly throwing an error trying to read
 333    an unavailable PC.  */
 334
 335 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 336
 337 /* Closely related to the resume address, various symbol table
 338    attributes that are determined by the PC.  Note that for a normal
 339    frame, the PC refers to the resume address after the return, and
 340    not the call instruction.  In such a case, the address is adjusted
 341    so that it (approximately) identifies the call site (and not the
 342    return site).
 343
 344    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 345    computed value.  Working on the assumption that the bottle-neck is
 346    in the single step code, and that code causes the frame cache to be
 347    constantly flushed, caching things in a frame is probably of little
 348    benefit.  As they say `show us the numbers'.
 349
 350    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 351    find_frame_block(), find_frame_partial_function(),
 352    find_frame_symtab(), find_frame_function().  Each will need to be
 353    carefully considered to determine if the real intent was for it to
 354    apply to the PC or the adjusted PC.  */
 355 extern void find_frame_sal (struct frame_info *frame,
 356                             struct symtab_and_line *sal);
 357
 358 /* Set the current source and line to the location given by frame
 359    FRAME, if possible.  When CENTER is true, adjust so the relevant
 360    line is in the center of the next 'list'.  */
 361
 362 void set_current_sal_from_frame (struct frame_info *, int);
 363
 364 /* Return the frame base (what ever that is) (DEPRECATED).
 365
 366    Old code was trying to use this single method for two conflicting
 367    purposes.  Such code needs to be updated to use either of:
 368
 369    get_frame_id: A low level frame unique identifier, that consists of
 370    both a stack and a function address, that can be used to uniquely
 371    identify a frame.  This value is determined by the frame's
 372    low-level unwinder, the stack part [typically] being the
 373    top-of-stack of the previous frame, and the function part being the
 374    function's start address.  Since the correct identification of a
 375    frameless function requires both a stack and function address,
 376    the old get_frame_base method was not sufficient.
 377
 378    get_frame_base_address: get_frame_locals_address:
 379    get_frame_args_address: A set of high-level debug-info dependant
 380    addresses that fall within the frame.  These addresses almost
 381    certainly will not match the stack address part of a frame ID (as
 382    returned by get_frame_base).
 383
 384    This replaced: frame->frame; */
 385
 386 extern CORE_ADDR get_frame_base (struct frame_info *);
 387
 388 /* Return the per-frame unique identifer.  Can be used to relocate a
 389    frame after a frame cache flush (and other similar operations).  If
 390    FI is NULL, return the null_frame_id.
 391
 392    NOTE: kettenis/20040508: These functions return a structure.  On
 393    platforms where structures are returned in static storage (vax,
 394    m68k), this may trigger compiler bugs in code like:
 395
 396    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 397
 398    where the return value from the first get_frame_id (l) gets
 399    overwritten by the second get_frame_id (r).  Please avoid writing
 400    code like this.  Use code like:
 401
 402    struct frame_id id = get_frame_id (l);
 403    if (frame_id_eq (id, get_frame_id (r)))
 404
 405    instead, since that avoids the bug.  */
 406 extern struct frame_id get_frame_id (struct frame_info *fi);
 407 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 408 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 409
 410 /* Assuming that a frame is `normal', return its base-address, or 0 if
 411    the information isn't available.  NOTE: This address is really only
 412    meaningful to the frame's high-level debug info.  */
 413 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 414
 415 /* Assuming that a frame is `normal', return the base-address of the
 416    local variables, or 0 if the information isn't available.  NOTE:
 417    This address is really only meaningful to the frame's high-level
 418    debug info.  Typically, the argument and locals share a single
 419    base-address.  */
 420 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 421
 422 /* Assuming that a frame is `normal', return the base-address of the
 423    parameter list, or 0 if that information isn't available.  NOTE:
 424    This address is really only meaningful to the frame's high-level
 425    debug info.  Typically, the argument and locals share a single
 426    base-address.  */
 427 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 428
 429 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 430    for an invalid frame).  */
 431 extern int frame_relative_level (struct frame_info *fi);
 432
 433 /* Return the frame's type.  */
 434
 435 extern enum frame_type get_frame_type (struct frame_info *);
 436
 437 /* Return the frame's program space.  */
 438 extern struct program_space *get_frame_program_space (struct frame_info *);
 439
 440 /* Unwind THIS frame's program space from the NEXT frame.  */
 441 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 442
 443 /* Return the frame's address space.  */
 444 extern struct address_space *get_frame_address_space (struct frame_info *);
 445
 446 /* For frames where we can not unwind further, describe why.  */
 447
 448 enum unwind_stop_reason
 449   {
 450 #define SET(name, description) name,
 451 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 452 #define LAST_ENTRY(name) UNWIND_LAST = name,
 453 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 454
 455 #include "unwind_stop_reasons.def"
 456 #undef SET
 457 #undef FIRST_ENTRY
 458 #undef LAST_ENTRY
 459 #undef FIRST_ERROR
 460   };
 461
 462 /* Return the reason why we can't unwind past this frame.  */
 463
 464 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 465
 466 /* Translate a reason code to an informative string.  */
 467
 468 const char *frame_stop_reason_string (enum unwind_stop_reason);
 469
 470 /* Unwind the stack frame so that the value of REGNUM, in the previous
 471    (up, older) frame is returned.  If VALUEP is NULL, don't
 472    fetch/compute the value.  Instead just return the location of the
 473    value.  */
 474 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 475                                    int *optimizedp, int *unavailablep,
 476                                    enum lval_type *lvalp,
 477                                    CORE_ADDR *addrp, int *realnump,
 478                                    gdb_byte *valuep);
 479
 480 /* Fetch a register from this, or unwind a register from the next
 481    frame.  Note that the get_frame methods are wrappers to
 482    frame->next->unwind.  They all [potentially] throw an error if the
 483    fetch fails.  The value methods never return NULL, but usually
 484    do return a lazy value.  */
 485
 486 extern void frame_unwind_register (struct frame_info *frame,
 487                                    int regnum, gdb_byte *buf);
 488 extern void get_frame_register (struct frame_info *frame,
 489                                 int regnum, gdb_byte *buf);
 490
 491 struct value *frame_unwind_register_value (struct frame_info *frame,
 492                                            int regnum);
 493 struct value *get_frame_register_value (struct frame_info *frame,
 494                                         int regnum);
 495
 496 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 497                                              int regnum);
 498 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 499                                           int regnum);
 500 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 501                                                int regnum);
 502 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 503                                              int regnum);
 504
 505 /* Read a register from this, or unwind a register from the next
 506    frame.  Note that the read_frame methods are wrappers to
 507    get_frame_register_value, that do not throw if the result is
 508    optimized out or unavailable.  */
 509
 510 extern int read_frame_register_unsigned (struct frame_info *frame,
 511                                          int regnum, ULONGEST *val);
 512
 513 /* Get the value of the register that belongs to this FRAME.  This
 514    function is a wrapper to the call sequence ``frame_register_unwind
 515    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 516    VALUEP is NULL, the registers value is not fetched/computed.  */
 517
 518 extern void frame_register (struct frame_info *frame, int regnum,
 519                             int *optimizedp, int *unavailablep,
 520                             enum lval_type *lvalp,
 521                             CORE_ADDR *addrp, int *realnump,
 522                             gdb_byte *valuep);
 523
 524 /* The reverse.  Store a register value relative to the specified
 525    frame.  Note: this call makes the frame's state undefined.  The
 526    register and frame caches must be flushed.  */
 527 extern void put_frame_register (struct frame_info *frame, int regnum,
 528                                 const gdb_byte *buf);
 529
 530 /* Read LEN bytes from one or multiple registers starting with REGNUM
 531    in frame FRAME, starting at OFFSET, into BUF.  If the register
 532    contents are optimized out or unavailable, set *OPTIMIZEDP,
 533    *UNAVAILABLEP accordingly.  */
 534 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 535                                      CORE_ADDR offset, int len,
 536                                      gdb_byte *myaddr,
 537                                      int *optimizedp, int *unavailablep);
 538
 539 /* Write LEN bytes to one or multiple registers starting with REGNUM
 540    in frame FRAME, starting at OFFSET, into BUF.  */
 541 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 542                                       CORE_ADDR offset, int len,
 543                                       const gdb_byte *myaddr);
 544
 545 /* Unwind the PC.  Strictly speaking return the resume address of the
 546    calling frame.  For GDB, `pc' is the resume address and not a
 547    specific register.  */
 548
 549 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 550
 551 /* Same as frame_unwind_caller_pc, but returns a boolean indication of
 552    whether the caller PC is determinable (when the PC is unavailable,
 553    it will not be), instead of possibly throwing an error trying to
 554    read unavailable memory or registers.  */
 555
 556 extern int frame_unwind_caller_pc_if_available (struct frame_info *this_frame,
 557                                                 CORE_ADDR *pc);
 558
 559 /* Discard the specified frame.  Restoring the registers to the state
 560    of the caller.  */
 561 extern void frame_pop (struct frame_info *frame);
 562
 563 /* Return memory from the specified frame.  A frame knows its thread /
 564    LWP and hence can find its way down to a target.  The assumption
 565    here is that the current and previous frame share a common address
 566    space.
 567
 568    If the memory read fails, these methods throw an error.
 569
 570    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 571    methods?  That isn't clear.  Can code, for instance, assume that
 572    this and the previous frame's memory or architecture are identical?
 573    If architecture / memory changes are always separated by special
 574    adaptor frames this should be ok.  */
 575
 576 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 577                               gdb_byte *buf, int len);
 578 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 579                                         CORE_ADDR memaddr, int len);
 580 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 581                                            CORE_ADDR memaddr, int len);
 582
 583 /* Same as above, but return non-zero when the entire memory read
 584    succeeds, zero otherwize.  */
 585 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 586                                      CORE_ADDR addr, gdb_byte *buf, int len);
 587
 588 /* Return this frame's architecture.  */
 589 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 590
 591 /* Return the previous frame's architecture.  */
 592 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 593
 594 /* Return the previous frame's architecture, skipping inline functions.  */
 595 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 596
 597
 598 /* Values for the source flag to be used in print_frame_info_base().  */
 599 enum print_what
 600   {
 601     /* Print only the source line, like in stepi.  */
 602     SRC_LINE = -1,
 603     /* Print only the location, i.e. level, address (sometimes)
 604        function, args, file, line, line num.  */
 605     LOCATION,
 606     /* Print both of the above.  */
 607     SRC_AND_LOC,
 608     /* Print location only, but always include the address.  */
 609     LOC_AND_ADDRESS
 610   };
 611
 612 /* Allocate zero initialized memory from the frame cache obstack.
 613    Appendices to the frame info (such as the unwind cache) should
 614    allocate memory using this method.  */
 615
 616 extern void *frame_obstack_zalloc (unsigned long size);
 617 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 618   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 619 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 620   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 621
 622 /* Create a regcache, and copy the frame's registers into it.  */
 623 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 624
 625 extern struct block *get_frame_block (struct frame_info *,
 626                                       CORE_ADDR *addr_in_block);
 627
 628 /* Return the `struct block' that belongs to the selected thread's
 629    selected frame.  If the inferior has no state, return NULL.
 630
 631    NOTE: cagney/2002-11-29:
 632
 633    No state?  Does the inferior have any execution state (a core file
 634    does, an executable does not).  At present the code tests
 635    `target_has_stack' but I'm left wondering if it should test
 636    `target_has_registers' or, even, a merged target_has_state.
 637
 638    Should it look at the most recently specified SAL?  If the target
 639    has no state, should this function try to extract a block from the
 640    most recently selected SAL?  That way `list foo' would give it some
 641    sort of reference point.  Then again, perhaps that would confuse
 642    things.
 643
 644    Calls to this function can be broken down into two categories: Code
 645    that uses the selected block as an additional, but optional, data
 646    point; Code that uses the selected block as a prop, when it should
 647    have the relevant frame/block/pc explicitly passed in.
 648
 649    The latter can be eliminated by correctly parameterizing the code,
 650    the former though is more interesting.  Per the "address" command,
 651    it occurs in the CLI code and makes it possible for commands to
 652    work, even when the inferior has no state.  */
 653
 654 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 655
 656 extern struct symbol *get_frame_function (struct frame_info *);
 657
 658 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 659
 660 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 661
 662 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
 663                                         enum print_what print_what);
 664
 665 extern void print_stack_frame (struct frame_info *, int print_level,
 666                                enum print_what print_what);
 667
 668 extern void print_frame_info (struct frame_info *, int print_level,
 669                               enum print_what print_what, int args);
 670
 671 extern struct frame_info *block_innermost_frame (const struct block *);
 672
 673 extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
 674                                 gdb_byte *buf);
 675
 676 /* From stack.c.  */
 677
 678 extern const char print_entry_values_no[];
 679 extern const char print_entry_values_only[];
 680 extern const char print_entry_values_preferred[];
 681 extern const char print_entry_values_if_needed[];
 682 extern const char print_entry_values_both[];
 683 extern const char print_entry_values_compact[];
 684 extern const char print_entry_values_default[];
 685 extern const char *print_entry_values;
 686
 687 /* Inferior function parameter value read in from a frame.  */
 688
 689 struct frame_arg
 690 {
 691   /* Symbol for this parameter used for example for its name.  */
 692   struct symbol *sym;
 693
 694   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 695      ERROR are NULL this parameter's value should not be printed.  */
 696   struct value *val;
 697
 698   /* String containing the error message, it is more usually NULL indicating no
 699      error occured reading this parameter.  */
 700   char *error;
 701
 702   /* One of the print_entry_values_* entries as appropriate specifically for
 703      this frame_arg.  It will be different from print_entry_values.  With
 704      print_entry_values_no this frame_arg should be printed as a normal
 705      parameter.  print_entry_values_only says it should be printed as entry
 706      value parameter.  print_entry_values_compact says it should be printed as
 707      both as a normal parameter and entry values parameter having the same
 708      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 709      (in such case print_entry_values_no and print_entry_values_only is used
 710      for each parameter kind specifically.  */
 711   const char *entry_kind;
 712 };
 713
 714 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 715                             struct frame_arg *argp,
 716                             struct frame_arg *entryargp);
 717
 718 extern void args_info (char *, int);
 719
 720 extern void locals_info (char *, int);
 721
 722 extern void (*deprecated_selected_frame_level_changed_hook) (int);
 723
 724 extern void return_command (char *, int);
 725
 726 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 727    Return a cleanup which should be called if unwinding fails, and
 728    discarded if it succeeds.  */
 729
 730 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 731                                            const struct frame_unwind *unwind);
 732
 733 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 734
 735    You might think that calls to this function can simply be replaced by a
 736    call to get_selected_frame().
 737
 738    Unfortunately, it isn't that easy.
 739
 740    The relevant code needs to be audited to determine if it is
 741    possible (or practical) to instead pass the applicable frame in as a
 742    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 743    the deprecated_selected_frame global, while its replacement,
 744    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 745    The only real exceptions occur at the edge (in the CLI code) where
 746    user commands need to pick up the selected frame before proceeding.
 747
 748    There are also some functions called with a NULL frame meaning either "the
 749    program is not running" or "use the selected frame".
 750
 751    This is important.  GDB is trying to stamp out the hack:
 752
 753    saved_frame = deprecated_safe_get_selected_frame ();
 754    select_frame (...);
 755    hack_using_global_selected_frame ();
 756    select_frame (saved_frame);
 757
 758    Take care!
 759
 760    This function calls get_selected_frame if the inferior should have a
 761    frame, or returns NULL otherwise.  */
 762
 763 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 764
 765 /* Create a frame using the specified BASE and PC.  */
 766
 767 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 768
 769 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 770    otherwise.  */
 771
 772 extern int frame_unwinder_is (struct frame_info *fi,
 773                               const struct frame_unwind *unwinder);
 774
 775 #endif /* !defined (FRAME_H)  */