gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2016 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 #include "language.h"
  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 struct ui_out;
  81
  82 /* Status of a given frame's stack.  */
  83
  84 enum frame_id_stack_status
  85 {
  86   /* Stack address is invalid.  E.g., this frame is the outermost
  87      (i.e., _start), and the stack hasn't been setup yet.  */
  88   FID_STACK_INVALID = 0,
  89
  90   /* Stack address is valid, and is found in the stack_addr field.  */
  91   FID_STACK_VALID = 1,
  92
  93   /* Stack address is unavailable.  I.e., there's a valid stack, but
  94      we don't know where it is (because memory or registers we'd
  95      compute it from were not collected).  */
  96   FID_STACK_UNAVAILABLE = -1
  97 };
  98
  99 /* The frame object.  */
 100
 101 struct frame_info;
 102
 103 /* The frame object's ID.  This provides a per-frame unique identifier
 104    that can be used to relocate a `struct frame_info' after a target
 105    resume or a frame cache destruct.  It of course assumes that the
 106    inferior hasn't unwound the stack past that frame.  */
 107
 108 struct frame_id
 109 {
 110   /* The frame's stack address.  This shall be constant through out
 111      the lifetime of a frame.  Note that this requirement applies to
 112      not just the function body, but also the prologue and (in theory
 113      at least) the epilogue.  Since that value needs to fall either on
 114      the boundary, or within the frame's address range, the frame's
 115      outer-most address (the inner-most address of the previous frame)
 116      is used.  Watch out for all the legacy targets that still use the
 117      function pointer register or stack pointer register.  They are
 118      wrong.
 119
 120      This field is valid only if frame_id.stack_status is
 121      FID_STACK_VALID.  It will be 0 for other
 122      FID_STACK_... statuses.  */
 123   CORE_ADDR stack_addr;
 124
 125   /* The frame's code address.  This shall be constant through out the
 126      lifetime of the frame.  While the PC (a.k.a. resume address)
 127      changes as the function is executed, this code address cannot.
 128      Typically, it is set to the address of the entry point of the
 129      frame's function (as returned by get_frame_func).
 130
 131      For inlined functions (INLINE_DEPTH != 0), this is the address of
 132      the first executed instruction in the block corresponding to the
 133      inlined function.
 134
 135      This field is valid only if code_addr_p is true.  Otherwise, this
 136      frame is considered to have a wildcard code address, i.e. one that
 137      matches every address value in frame comparisons.  */
 138   CORE_ADDR code_addr;
 139
 140   /* The frame's special address.  This shall be constant through out the
 141      lifetime of the frame.  This is used for architectures that may have
 142      frames that do not change the stack but are still distinct and have
 143      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 144      stack for registers).  This field is treated as unordered - i.e. will
 145      not be used in frame ordering comparisons.
 146
 147      This field is valid only if special_addr_p is true.  Otherwise, this
 148      frame is considered to have a wildcard special address, i.e. one that
 149      matches every address value in frame comparisons.  */
 150   CORE_ADDR special_addr;
 151
 152   /* Flags to indicate the above fields have valid contents.  */
 153   ENUM_BITFIELD(frame_id_stack_status) stack_status : 2;
 154   unsigned int code_addr_p : 1;
 155   unsigned int special_addr_p : 1;
 156
 157   /* It is non-zero for a frame made up by GDB without stack data
 158      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 159      Caller of inlined function will have it zero, each more inner called frame
 160      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 161   int artificial_depth;
 162 };
 163
 164 /* Methods for constructing and comparing Frame IDs.  */
 165
 166 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 167 extern const struct frame_id null_frame_id;
 168
 169 /* This means "there is no frame ID, but there is a frame".  It should be
 170    replaced by best-effort frame IDs for the outermost frame, somehow.
 171    The implementation is only special_addr_p set.  */
 172 extern const struct frame_id outer_frame_id;
 173
 174 /* Flag to control debugging.  */
 175
 176 extern unsigned int frame_debug;
 177
 178 /* Construct a frame ID.  The first parameter is the frame's constant
 179    stack address (typically the outer-bound), and the second the
 180    frame's constant code address (typically the entry point).
 181    The special identifier address is set to indicate a wild card.  */
 182 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 183                                        CORE_ADDR code_addr);
 184
 185 /* Construct a special frame ID.  The first parameter is the frame's constant
 186    stack address (typically the outer-bound), the second is the
 187    frame's constant code address (typically the entry point),
 188    and the third parameter is the frame's special identifier address.  */
 189 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 190                                                CORE_ADDR code_addr,
 191                                                CORE_ADDR special_addr);
 192
 193 /* Construct a frame ID representing a frame where the stack address
 194    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 195    address (typically the entry point).  The special identifier
 196    address is set to indicate a wild card.  */
 197 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 198
 199 /* Construct a frame ID representing a frame where the stack address
 200    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 201    address (typically the entry point).  SPECIAL_ADDR is the special
 202    identifier address.  */
 203 extern struct frame_id
 204   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 205                                             CORE_ADDR special_addr);
 206
 207 /* Construct a wild card frame ID.  The parameter is the frame's constant
 208    stack address (typically the outer-bound).  The code address as well
 209    as the special identifier address are set to indicate wild cards.  */
 210 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 211
 212 /* Returns non-zero when L is a valid frame (a valid frame has a
 213    non-zero .base).  The outermost frame is valid even without an
 214    ID.  */
 215 extern int frame_id_p (struct frame_id l);
 216
 217 /* Returns non-zero when L is a valid frame representing a frame made up by GDB
 218    without stack data representation in inferior, such as INLINE_FRAME or
 219    TAILCALL_FRAME.  */
 220 extern int frame_id_artificial_p (struct frame_id l);
 221
 222 /* Returns non-zero when L and R identify the same frame, or, if
 223    either L or R have a zero .func, then the same frame base.  */
 224 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 225
 226 /* Write the internal representation of a frame ID on the specified
 227    stream.  */
 228 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 229
 230
 231 /* Frame types.  Some are real, some are signal trampolines, and some
 232    are completely artificial (dummy).  */
 233
 234 enum frame_type
 235 {
 236   /* A true stack frame, created by the target program during normal
 237      execution.  */
 238   NORMAL_FRAME,
 239   /* A fake frame, created by GDB when performing an inferior function
 240      call.  */
 241   DUMMY_FRAME,
 242   /* A frame representing an inlined function, associated with an
 243      upcoming (prev, outer, older) NORMAL_FRAME.  */
 244   INLINE_FRAME,
 245   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 246   TAILCALL_FRAME,
 247   /* In a signal handler, various OSs handle this in various ways.
 248      The main thing is that the frame may be far from normal.  */
 249   SIGTRAMP_FRAME,
 250   /* Fake frame representing a cross-architecture call.  */
 251   ARCH_FRAME,
 252   /* Sentinel or registers frame.  This frame obtains register values
 253      direct from the inferior's registers.  */
 254   SENTINEL_FRAME
 255 };
 256
 257 /* For every stopped thread, GDB tracks two frames: current and
 258    selected.  Current frame is the inner most frame of the selected
 259    thread.  Selected frame is the one being examined by the GDB
 260    CLI (selected using `up', `down', ...).  The frames are created
 261    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 262 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 263    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 264    selected frame.  At present GDB only tracks the selected frame of
 265    the current thread.  But be warned, that might change.  */
 266 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 267    and current frame can be active.  Switching threads causes gdb to
 268    discard all that cached frame information.  Ulgh!  Instead, current
 269    and selected frame should be bound to a thread.  */
 270
 271 /* On demand, create the inner most frame using information found in
 272    the inferior.  If the inner most frame can't be created, throw an
 273    error.  */
 274 extern struct frame_info *get_current_frame (void);
 275
 276 /* Does the current target interface have enough state to be able to
 277    query the current inferior for frame info, and is the inferior in a
 278    state where that is possible?  */
 279 extern int has_stack_frames (void);
 280
 281 /* Invalidates the frame cache (this function should have been called
 282    invalidate_cached_frames).
 283
 284    FIXME: cagney/2002-11-28: There should be two methods: one that
 285    reverts the thread's selected frame back to current frame (for when
 286    the inferior resumes) and one that does not (for when the user
 287    modifies the target invalidating the frame cache).  */
 288 extern void reinit_frame_cache (void);
 289
 290 /* On demand, create the selected frame and then return it.  If the
 291    selected frame can not be created, this function prints then throws
 292    an error.  When MESSAGE is non-NULL, use it for the error message,
 293    otherwize use a generic error message.  */
 294 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 295    frame, this function always returns the current (inner most) frame.
 296    It should instead, when a thread has previously had its frame
 297    selected (but not resumed) and the frame cache invalidated, find
 298    and then return that thread's previously selected frame.  */
 299 extern struct frame_info *get_selected_frame (const char *message);
 300
 301 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 302 extern struct frame_info *get_selected_frame_if_set (void);
 303
 304 /* Select a specific frame.  NULL, apparently implies re-select the
 305    inner most frame.  */
 306 extern void select_frame (struct frame_info *);
 307
 308 /* Given a FRAME, return the next (more inner, younger) or previous
 309    (more outer, older) frame.  */
 310 extern struct frame_info *get_prev_frame (struct frame_info *);
 311 extern struct frame_info *get_next_frame (struct frame_info *);
 312
 313 /* Return a "struct frame_info" corresponding to the frame that called
 314    THIS_FRAME.  Returns NULL if there is no such frame.
 315
 316    Unlike get_prev_frame, this function always tries to unwind the
 317    frame.  */
 318 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 319
 320 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 321    is not found.  */
 322 extern struct frame_info *frame_find_by_id (struct frame_id id);
 323
 324 /* Base attributes of a frame: */
 325
 326 /* The frame's `resume' address.  Where the program will resume in
 327    this frame.
 328
 329    This replaced: frame->pc; */
 330 extern CORE_ADDR get_frame_pc (struct frame_info *);
 331
 332 /* Same as get_frame_pc, but return a boolean indication of whether
 333    the PC is actually available, instead of throwing an error.  */
 334
 335 extern int get_frame_pc_if_available (struct frame_info *frame,
 336                                       CORE_ADDR *pc);
 337
 338 /* An address (not necessarily aligned to an instruction boundary)
 339    that falls within THIS frame's code block.
 340
 341    When a function call is the last statement in a block, the return
 342    address for the call may land at the start of the next block.
 343    Similarly, if a no-return function call is the last statement in
 344    the function, the return address may end up pointing beyond the
 345    function, and possibly at the start of the next function.
 346
 347    These methods make an allowance for this.  For call frames, this
 348    function returns the frame's PC-1 which "should" be an address in
 349    the frame's block.  */
 350
 351 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 352
 353 /* Same as get_frame_address_in_block, but returns a boolean
 354    indication of whether the frame address is determinable (when the
 355    PC is unavailable, it will not be), instead of possibly throwing an
 356    error trying to read an unavailable PC.  */
 357
 358 extern int
 359   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 360                                            CORE_ADDR *pc);
 361
 362 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 363    known as top-of-stack.  */
 364
 365 extern CORE_ADDR get_frame_sp (struct frame_info *);
 366
 367 /* Following on from the `resume' address.  Return the entry point
 368    address of the function containing that resume address, or zero if
 369    that function isn't known.  */
 370 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 371
 372 /* Same as get_frame_func, but returns a boolean indication of whether
 373    the frame function is determinable (when the PC is unavailable, it
 374    will not be), instead of possibly throwing an error trying to read
 375    an unavailable PC.  */
 376
 377 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 378
 379 /* Closely related to the resume address, various symbol table
 380    attributes that are determined by the PC.  Note that for a normal
 381    frame, the PC refers to the resume address after the return, and
 382    not the call instruction.  In such a case, the address is adjusted
 383    so that it (approximately) identifies the call site (and not the
 384    return site).
 385
 386    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 387    computed value.  Working on the assumption that the bottle-neck is
 388    in the single step code, and that code causes the frame cache to be
 389    constantly flushed, caching things in a frame is probably of little
 390    benefit.  As they say `show us the numbers'.
 391
 392    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 393    find_frame_block(), find_frame_partial_function(),
 394    find_frame_symtab(), find_frame_function().  Each will need to be
 395    carefully considered to determine if the real intent was for it to
 396    apply to the PC or the adjusted PC.  */
 397 extern void find_frame_sal (struct frame_info *frame,
 398                             struct symtab_and_line *sal);
 399
 400 /* Set the current source and line to the location given by frame
 401    FRAME, if possible.  */
 402
 403 void set_current_sal_from_frame (struct frame_info *);
 404
 405 /* Return the frame base (what ever that is) (DEPRECATED).
 406
 407    Old code was trying to use this single method for two conflicting
 408    purposes.  Such code needs to be updated to use either of:
 409
 410    get_frame_id: A low level frame unique identifier, that consists of
 411    both a stack and a function address, that can be used to uniquely
 412    identify a frame.  This value is determined by the frame's
 413    low-level unwinder, the stack part [typically] being the
 414    top-of-stack of the previous frame, and the function part being the
 415    function's start address.  Since the correct identification of a
 416    frameless function requires both a stack and function address,
 417    the old get_frame_base method was not sufficient.
 418
 419    get_frame_base_address: get_frame_locals_address:
 420    get_frame_args_address: A set of high-level debug-info dependant
 421    addresses that fall within the frame.  These addresses almost
 422    certainly will not match the stack address part of a frame ID (as
 423    returned by get_frame_base).
 424
 425    This replaced: frame->frame; */
 426
 427 extern CORE_ADDR get_frame_base (struct frame_info *);
 428
 429 /* Return the per-frame unique identifer.  Can be used to relocate a
 430    frame after a frame cache flush (and other similar operations).  If
 431    FI is NULL, return the null_frame_id.
 432
 433    NOTE: kettenis/20040508: These functions return a structure.  On
 434    platforms where structures are returned in static storage (vax,
 435    m68k), this may trigger compiler bugs in code like:
 436
 437    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 438
 439    where the return value from the first get_frame_id (l) gets
 440    overwritten by the second get_frame_id (r).  Please avoid writing
 441    code like this.  Use code like:
 442
 443    struct frame_id id = get_frame_id (l);
 444    if (frame_id_eq (id, get_frame_id (r)))
 445
 446    instead, since that avoids the bug.  */
 447 extern struct frame_id get_frame_id (struct frame_info *fi);
 448 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 449 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 450
 451 /* Assuming that a frame is `normal', return its base-address, or 0 if
 452    the information isn't available.  NOTE: This address is really only
 453    meaningful to the frame's high-level debug info.  */
 454 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 455
 456 /* Assuming that a frame is `normal', return the base-address of the
 457    local variables, or 0 if the information isn't available.  NOTE:
 458    This address is really only meaningful to the frame's high-level
 459    debug info.  Typically, the argument and locals share a single
 460    base-address.  */
 461 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 462
 463 /* Assuming that a frame is `normal', return the base-address of the
 464    parameter list, or 0 if that information isn't available.  NOTE:
 465    This address is really only meaningful to the frame's high-level
 466    debug info.  Typically, the argument and locals share a single
 467    base-address.  */
 468 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 469
 470 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 471    for an invalid frame).  */
 472 extern int frame_relative_level (struct frame_info *fi);
 473
 474 /* Return the frame's type.  */
 475
 476 extern enum frame_type get_frame_type (struct frame_info *);
 477
 478 /* Return the frame's program space.  */
 479 extern struct program_space *get_frame_program_space (struct frame_info *);
 480
 481 /* Unwind THIS frame's program space from the NEXT frame.  */
 482 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 483
 484 /* Return the frame's address space.  */
 485 extern struct address_space *get_frame_address_space (struct frame_info *);
 486
 487 /* For frames where we can not unwind further, describe why.  */
 488
 489 enum unwind_stop_reason
 490   {
 491 #define SET(name, description) name,
 492 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 493 #define LAST_ENTRY(name) UNWIND_LAST = name,
 494 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 495
 496 #include "unwind_stop_reasons.def"
 497 #undef SET
 498 #undef FIRST_ENTRY
 499 #undef LAST_ENTRY
 500 #undef FIRST_ERROR
 501   };
 502
 503 /* Return the reason why we can't unwind past this frame.  */
 504
 505 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 506
 507 /* Translate a reason code to an informative string.  This converts the
 508    generic stop reason codes into a generic string describing the code.
 509    For a possibly frame specific string explaining the stop reason, use
 510    FRAME_STOP_REASON_STRING instead.  */
 511
 512 const char *unwind_stop_reason_to_string (enum unwind_stop_reason);
 513
 514 /* Return a possibly frame specific string explaining why the unwind
 515    stopped here.  E.g., if unwinding tripped on a memory error, this
 516    will return the error description string, which includes the address
 517    that we failed to access.  If there's no specific reason stored for
 518    a frame then a generic reason string will be returned.
 519
 520    Should only be called for frames that don't have a previous frame.  */
 521
 522 const char *frame_stop_reason_string (struct frame_info *);
 523
 524 /* Unwind the stack frame so that the value of REGNUM, in the previous
 525    (up, older) frame is returned.  If VALUEP is NULL, don't
 526    fetch/compute the value.  Instead just return the location of the
 527    value.  */
 528 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 529                                    int *optimizedp, int *unavailablep,
 530                                    enum lval_type *lvalp,
 531                                    CORE_ADDR *addrp, int *realnump,
 532                                    gdb_byte *valuep);
 533
 534 /* Fetch a register from this, or unwind a register from the next
 535    frame.  Note that the get_frame methods are wrappers to
 536    frame->next->unwind.  They all [potentially] throw an error if the
 537    fetch fails.  The value methods never return NULL, but usually
 538    do return a lazy value.  */
 539
 540 extern void frame_unwind_register (struct frame_info *frame,
 541                                    int regnum, gdb_byte *buf);
 542 extern void get_frame_register (struct frame_info *frame,
 543                                 int regnum, gdb_byte *buf);
 544
 545 struct value *frame_unwind_register_value (struct frame_info *frame,
 546                                            int regnum);
 547 struct value *get_frame_register_value (struct frame_info *frame,
 548                                         int regnum);
 549
 550 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 551                                              int regnum);
 552 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 553                                           int regnum);
 554 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 555                                                int regnum);
 556 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 557                                              int regnum);
 558
 559 /* Read a register from this, or unwind a register from the next
 560    frame.  Note that the read_frame methods are wrappers to
 561    get_frame_register_value, that do not throw if the result is
 562    optimized out or unavailable.  */
 563
 564 extern int read_frame_register_unsigned (struct frame_info *frame,
 565                                          int regnum, ULONGEST *val);
 566
 567 /* Get the value of the register that belongs to this FRAME.  This
 568    function is a wrapper to the call sequence ``frame_register_unwind
 569    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 570    VALUEP is NULL, the registers value is not fetched/computed.  */
 571
 572 extern void frame_register (struct frame_info *frame, int regnum,
 573                             int *optimizedp, int *unavailablep,
 574                             enum lval_type *lvalp,
 575                             CORE_ADDR *addrp, int *realnump,
 576                             gdb_byte *valuep);
 577
 578 /* The reverse.  Store a register value relative to the specified
 579    frame.  Note: this call makes the frame's state undefined.  The
 580    register and frame caches must be flushed.  */
 581 extern void put_frame_register (struct frame_info *frame, int regnum,
 582                                 const gdb_byte *buf);
 583
 584 /* Read LEN bytes from one or multiple registers starting with REGNUM
 585    in frame FRAME, starting at OFFSET, into BUF.  If the register
 586    contents are optimized out or unavailable, set *OPTIMIZEDP,
 587    *UNAVAILABLEP accordingly.  */
 588 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 589                                      CORE_ADDR offset, int len,
 590                                      gdb_byte *myaddr,
 591                                      int *optimizedp, int *unavailablep);
 592
 593 /* Write LEN bytes to one or multiple registers starting with REGNUM
 594    in frame FRAME, starting at OFFSET, into BUF.  */
 595 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 596                                       CORE_ADDR offset, int len,
 597                                       const gdb_byte *myaddr);
 598
 599 /* Unwind the PC.  Strictly speaking return the resume address of the
 600    calling frame.  For GDB, `pc' is the resume address and not a
 601    specific register.  */
 602
 603 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 604
 605 /* Discard the specified frame.  Restoring the registers to the state
 606    of the caller.  */
 607 extern void frame_pop (struct frame_info *frame);
 608
 609 /* Return memory from the specified frame.  A frame knows its thread /
 610    LWP and hence can find its way down to a target.  The assumption
 611    here is that the current and previous frame share a common address
 612    space.
 613
 614    If the memory read fails, these methods throw an error.
 615
 616    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 617    methods?  That isn't clear.  Can code, for instance, assume that
 618    this and the previous frame's memory or architecture are identical?
 619    If architecture / memory changes are always separated by special
 620    adaptor frames this should be ok.  */
 621
 622 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 623                               gdb_byte *buf, int len);
 624 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 625                                         CORE_ADDR memaddr, int len);
 626 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 627                                            CORE_ADDR memaddr, int len);
 628
 629 /* Same as above, but return non-zero when the entire memory read
 630    succeeds, zero otherwize.  */
 631 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 632                                      CORE_ADDR addr, gdb_byte *buf, int len);
 633
 634 /* Return this frame's architecture.  */
 635 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 636
 637 /* Return the previous frame's architecture.  */
 638 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 639
 640 /* Return the previous frame's architecture, skipping inline functions.  */
 641 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 642
 643
 644 /* Values for the source flag to be used in print_frame_info_base().  */
 645 enum print_what
 646   {
 647     /* Print only the source line, like in stepi.  */
 648     SRC_LINE = -1,
 649     /* Print only the location, i.e. level, address (sometimes)
 650        function, args, file, line, line num.  */
 651     LOCATION,
 652     /* Print both of the above.  */
 653     SRC_AND_LOC,
 654     /* Print location only, but always include the address.  */
 655     LOC_AND_ADDRESS
 656   };
 657
 658 /* Allocate zero initialized memory from the frame cache obstack.
 659    Appendices to the frame info (such as the unwind cache) should
 660    allocate memory using this method.  */
 661
 662 extern void *frame_obstack_zalloc (unsigned long size);
 663 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 664   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 665 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 666   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 667
 668 /* Create a regcache, and copy the frame's registers into it.  */
 669 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 670
 671 extern const struct block *get_frame_block (struct frame_info *,
 672                                             CORE_ADDR *addr_in_block);
 673
 674 /* Return the `struct block' that belongs to the selected thread's
 675    selected frame.  If the inferior has no state, return NULL.
 676
 677    NOTE: cagney/2002-11-29:
 678
 679    No state?  Does the inferior have any execution state (a core file
 680    does, an executable does not).  At present the code tests
 681    `target_has_stack' but I'm left wondering if it should test
 682    `target_has_registers' or, even, a merged target_has_state.
 683
 684    Should it look at the most recently specified SAL?  If the target
 685    has no state, should this function try to extract a block from the
 686    most recently selected SAL?  That way `list foo' would give it some
 687    sort of reference point.  Then again, perhaps that would confuse
 688    things.
 689
 690    Calls to this function can be broken down into two categories: Code
 691    that uses the selected block as an additional, but optional, data
 692    point; Code that uses the selected block as a prop, when it should
 693    have the relevant frame/block/pc explicitly passed in.
 694
 695    The latter can be eliminated by correctly parameterizing the code,
 696    the former though is more interesting.  Per the "address" command,
 697    it occurs in the CLI code and makes it possible for commands to
 698    work, even when the inferior has no state.  */
 699
 700 extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 701
 702 extern struct symbol *get_frame_function (struct frame_info *);
 703
 704 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 705
 706 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 707
 708 /* Wrapper over print_stack_frame modifying current_uiout with UIOUT for
 709    the function call.  */
 710
 711 extern void print_stack_frame_to_uiout (struct ui_out *uiout,
 712                                         struct frame_info *, int print_level,
 713                                         enum print_what print_what,
 714                                         int set_current_sal);
 715
 716 extern void print_stack_frame (struct frame_info *, int print_level,
 717                                enum print_what print_what,
 718                                int set_current_sal);
 719
 720 extern void print_frame_info (struct frame_info *, int print_level,
 721                               enum print_what print_what, int args,
 722                               int set_current_sal);
 723
 724 extern struct frame_info *block_innermost_frame (const struct block *);
 725
 726 extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
 727                                 gdb_byte *buf);
 728
 729 /* From stack.c.  */
 730
 731 extern const char print_entry_values_no[];
 732 extern const char print_entry_values_only[];
 733 extern const char print_entry_values_preferred[];
 734 extern const char print_entry_values_if_needed[];
 735 extern const char print_entry_values_both[];
 736 extern const char print_entry_values_compact[];
 737 extern const char print_entry_values_default[];
 738 extern const char *print_entry_values;
 739
 740 /* Inferior function parameter value read in from a frame.  */
 741
 742 struct frame_arg
 743 {
 744   /* Symbol for this parameter used for example for its name.  */
 745   struct symbol *sym;
 746
 747   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 748      ERROR are NULL this parameter's value should not be printed.  */
 749   struct value *val;
 750
 751   /* String containing the error message, it is more usually NULL indicating no
 752      error occured reading this parameter.  */
 753   char *error;
 754
 755   /* One of the print_entry_values_* entries as appropriate specifically for
 756      this frame_arg.  It will be different from print_entry_values.  With
 757      print_entry_values_no this frame_arg should be printed as a normal
 758      parameter.  print_entry_values_only says it should be printed as entry
 759      value parameter.  print_entry_values_compact says it should be printed as
 760      both as a normal parameter and entry values parameter having the same
 761      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 762      (in such case print_entry_values_no and print_entry_values_only is used
 763      for each parameter kind specifically.  */
 764   const char *entry_kind;
 765 };
 766
 767 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 768                             struct frame_arg *argp,
 769                             struct frame_arg *entryargp);
 770 extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
 771                               struct frame_arg *argp);
 772
 773 extern void args_info (char *, int);
 774
 775 extern void locals_info (char *, int);
 776
 777 extern void return_command (char *, int);
 778
 779 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 780    Return a cleanup which should be called if unwinding fails, and
 781    discarded if it succeeds.  */
 782
 783 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 784                                            const struct frame_unwind *unwind);
 785
 786 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 787
 788    You might think that calls to this function can simply be replaced by a
 789    call to get_selected_frame().
 790
 791    Unfortunately, it isn't that easy.
 792
 793    The relevant code needs to be audited to determine if it is
 794    possible (or practical) to instead pass the applicable frame in as a
 795    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 796    the deprecated_selected_frame global, while its replacement,
 797    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 798    The only real exceptions occur at the edge (in the CLI code) where
 799    user commands need to pick up the selected frame before proceeding.
 800
 801    There are also some functions called with a NULL frame meaning either "the
 802    program is not running" or "use the selected frame".
 803
 804    This is important.  GDB is trying to stamp out the hack:
 805
 806    saved_frame = deprecated_safe_get_selected_frame ();
 807    select_frame (...);
 808    hack_using_global_selected_frame ();
 809    select_frame (saved_frame);
 810
 811    Take care!
 812
 813    This function calls get_selected_frame if the inferior should have a
 814    frame, or returns NULL otherwise.  */
 815
 816 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 817
 818 /* Create a frame using the specified BASE and PC.  */
 819
 820 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 821
 822 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 823    otherwise.  */
 824
 825 extern int frame_unwinder_is (struct frame_info *fi,
 826                               const struct frame_unwind *unwinder);
 827
 828 /* Return the language of FRAME.  */
 829
 830 extern enum language get_frame_language (struct frame_info *frame);
 831
 832 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 833    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 834    chain.  */
 835
 836 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 837
 838 /* Return the first frame above FRAME or FRAME of which the code is
 839    writable.  */
 840
 841 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 842
 843 #endif /* !defined (FRAME_H)  */