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   /* Sentinel frame.  */
  94   FID_STACK_SENTINEL = 2,
  95
  96   /* Stack address is unavailable.  I.e., there's a valid stack, but
  97      we don't know where it is (because memory or registers we'd
  98      compute it from were not collected).  */
  99   FID_STACK_UNAVAILABLE = -1
 100 };
 101
 102 /* The frame object.  */
 103
 104 struct frame_info;
 105
 106 /* The frame object's ID.  This provides a per-frame unique identifier
 107    that can be used to relocate a `struct frame_info' after a target
 108    resume or a frame cache destruct.  It of course assumes that the
 109    inferior hasn't unwound the stack past that frame.  */
 110
 111 struct frame_id
 112 {
 113   /* The frame's stack address.  This shall be constant through out
 114      the lifetime of a frame.  Note that this requirement applies to
 115      not just the function body, but also the prologue and (in theory
 116      at least) the epilogue.  Since that value needs to fall either on
 117      the boundary, or within the frame's address range, the frame's
 118      outer-most address (the inner-most address of the previous frame)
 119      is used.  Watch out for all the legacy targets that still use the
 120      function pointer register or stack pointer register.  They are
 121      wrong.
 122
 123      This field is valid only if frame_id.stack_status is
 124      FID_STACK_VALID.  It will be 0 for other
 125      FID_STACK_... statuses.  */
 126   CORE_ADDR stack_addr;
 127
 128   /* The frame's code address.  This shall be constant through out the
 129      lifetime of the frame.  While the PC (a.k.a. resume address)
 130      changes as the function is executed, this code address cannot.
 131      Typically, it is set to the address of the entry point of the
 132      frame's function (as returned by get_frame_func).
 133
 134      For inlined functions (INLINE_DEPTH != 0), this is the address of
 135      the first executed instruction in the block corresponding to the
 136      inlined function.
 137
 138      This field is valid only if code_addr_p is true.  Otherwise, this
 139      frame is considered to have a wildcard code address, i.e. one that
 140      matches every address value in frame comparisons.  */
 141   CORE_ADDR code_addr;
 142
 143   /* The frame's special address.  This shall be constant through out the
 144      lifetime of the frame.  This is used for architectures that may have
 145      frames that do not change the stack but are still distinct and have
 146      some form of distinct identifier (e.g. the ia64 which uses a 2nd
 147      stack for registers).  This field is treated as unordered - i.e. will
 148      not be used in frame ordering comparisons.
 149
 150      This field is valid only if special_addr_p is true.  Otherwise, this
 151      frame is considered to have a wildcard special address, i.e. one that
 152      matches every address value in frame comparisons.  */
 153   CORE_ADDR special_addr;
 154
 155   /* Flags to indicate the above fields have valid contents.  */
 156   ENUM_BITFIELD(frame_id_stack_status) stack_status : 3;
 157   unsigned int code_addr_p : 1;
 158   unsigned int special_addr_p : 1;
 159
 160   /* It is non-zero for a frame made up by GDB without stack data
 161      representation in inferior, such as INLINE_FRAME or TAILCALL_FRAME.
 162      Caller of inlined function will have it zero, each more inner called frame
 163      will have it increasingly one, two etc.  Similarly for TAILCALL_FRAME.  */
 164   int artificial_depth;
 165 };
 166
 167 /* Methods for constructing and comparing Frame IDs.  */
 168
 169 /* For convenience.  All fields are zero.  This means "there is no frame".  */
 170 extern const struct frame_id null_frame_id;
 171
 172 /* Sentinel frame.  */
 173 extern const struct frame_id sentinel_frame_id;
 174
 175 /* This means "there is no frame ID, but there is a frame".  It should be
 176    replaced by best-effort frame IDs for the outermost frame, somehow.
 177    The implementation is only special_addr_p set.  */
 178 extern const struct frame_id outer_frame_id;
 179
 180 /* Flag to control debugging.  */
 181
 182 extern unsigned int frame_debug;
 183
 184 /* Construct a frame ID.  The first parameter is the frame's constant
 185    stack address (typically the outer-bound), and the second the
 186    frame's constant code address (typically the entry point).
 187    The special identifier address is set to indicate a wild card.  */
 188 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
 189                                        CORE_ADDR code_addr);
 190
 191 /* Construct a special frame ID.  The first parameter is the frame's constant
 192    stack address (typically the outer-bound), the second is the
 193    frame's constant code address (typically the entry point),
 194    and the third parameter is the frame's special identifier address.  */
 195 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
 196                                                CORE_ADDR code_addr,
 197                                                CORE_ADDR special_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).  The special identifier
 202    address is set to indicate a wild card.  */
 203 extern struct frame_id frame_id_build_unavailable_stack (CORE_ADDR code_addr);
 204
 205 /* Construct a frame ID representing a frame where the stack address
 206    exists, but is unavailable.  CODE_ADDR is the frame's constant code
 207    address (typically the entry point).  SPECIAL_ADDR is the special
 208    identifier address.  */
 209 extern struct frame_id
 210   frame_id_build_unavailable_stack_special (CORE_ADDR code_addr,
 211                                             CORE_ADDR special_addr);
 212
 213 /* Construct a wild card frame ID.  The parameter is the frame's constant
 214    stack address (typically the outer-bound).  The code address as well
 215    as the special identifier address are set to indicate wild cards.  */
 216 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
 217
 218 /* Returns non-zero when L is a valid frame (a valid frame has a
 219    non-zero .base).  The outermost frame is valid even without an
 220    ID.  */
 221 extern int frame_id_p (struct frame_id l);
 222
 223 /* Returns non-zero when L is a valid frame representing a frame made up by GDB
 224    without stack data representation in inferior, such as INLINE_FRAME or
 225    TAILCALL_FRAME.  */
 226 extern int frame_id_artificial_p (struct frame_id l);
 227
 228 /* Returns non-zero when L and R identify the same frame, or, if
 229    either L or R have a zero .func, then the same frame base.  */
 230 extern int frame_id_eq (struct frame_id l, struct frame_id r);
 231
 232 /* Write the internal representation of a frame ID on the specified
 233    stream.  */
 234 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
 235
 236
 237 /* Frame types.  Some are real, some are signal trampolines, and some
 238    are completely artificial (dummy).  */
 239
 240 enum frame_type
 241 {
 242   /* A true stack frame, created by the target program during normal
 243      execution.  */
 244   NORMAL_FRAME,
 245   /* A fake frame, created by GDB when performing an inferior function
 246      call.  */
 247   DUMMY_FRAME,
 248   /* A frame representing an inlined function, associated with an
 249      upcoming (prev, outer, older) NORMAL_FRAME.  */
 250   INLINE_FRAME,
 251   /* A virtual frame of a tail call - see dwarf2_tailcall_frame_unwind.  */
 252   TAILCALL_FRAME,
 253   /* In a signal handler, various OSs handle this in various ways.
 254      The main thing is that the frame may be far from normal.  */
 255   SIGTRAMP_FRAME,
 256   /* Fake frame representing a cross-architecture call.  */
 257   ARCH_FRAME,
 258   /* Sentinel or registers frame.  This frame obtains register values
 259      direct from the inferior's registers.  */
 260   SENTINEL_FRAME
 261 };
 262
 263 /* For every stopped thread, GDB tracks two frames: current and
 264    selected.  Current frame is the inner most frame of the selected
 265    thread.  Selected frame is the one being examined by the GDB
 266    CLI (selected using `up', `down', ...).  The frames are created
 267    on-demand (via get_prev_frame()) and then held in a frame cache.  */
 268 /* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
 269    sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
 270    selected frame.  At present GDB only tracks the selected frame of
 271    the current thread.  But be warned, that might change.  */
 272 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
 273    and current frame can be active.  Switching threads causes gdb to
 274    discard all that cached frame information.  Ulgh!  Instead, current
 275    and selected frame should be bound to a thread.  */
 276
 277 /* On demand, create the inner most frame using information found in
 278    the inferior.  If the inner most frame can't be created, throw an
 279    error.  */
 280 extern struct frame_info *get_current_frame (void);
 281
 282 /* Does the current target interface have enough state to be able to
 283    query the current inferior for frame info, and is the inferior in a
 284    state where that is possible?  */
 285 extern int has_stack_frames (void);
 286
 287 /* Invalidates the frame cache (this function should have been called
 288    invalidate_cached_frames).
 289
 290    FIXME: cagney/2002-11-28: There should be two methods: one that
 291    reverts the thread's selected frame back to current frame (for when
 292    the inferior resumes) and one that does not (for when the user
 293    modifies the target invalidating the frame cache).  */
 294 extern void reinit_frame_cache (void);
 295
 296 /* On demand, create the selected frame and then return it.  If the
 297    selected frame can not be created, this function prints then throws
 298    an error.  When MESSAGE is non-NULL, use it for the error message,
 299    otherwize use a generic error message.  */
 300 /* FIXME: cagney/2002-11-28: At present, when there is no selected
 301    frame, this function always returns the current (inner most) frame.
 302    It should instead, when a thread has previously had its frame
 303    selected (but not resumed) and the frame cache invalidated, find
 304    and then return that thread's previously selected frame.  */
 305 extern struct frame_info *get_selected_frame (const char *message);
 306
 307 /* If there is a selected frame, return it.  Otherwise, return NULL.  */
 308 extern struct frame_info *get_selected_frame_if_set (void);
 309
 310 /* Select a specific frame.  NULL, apparently implies re-select the
 311    inner most frame.  */
 312 extern void select_frame (struct frame_info *);
 313
 314 /* Given a FRAME, return the next (more inner, younger) or previous
 315    (more outer, older) frame.  */
 316 extern struct frame_info *get_prev_frame (struct frame_info *);
 317 extern struct frame_info *get_next_frame (struct frame_info *);
 318
 319 /* Like get_next_frame(), but allows return of the sentinel frame.  NULL
 320    is never returned.  */
 321 extern struct frame_info *get_next_frame_sentinel_okay (struct frame_info *);
 322
 323 /* Return a "struct frame_info" corresponding to the frame that called
 324    THIS_FRAME.  Returns NULL if there is no such frame.
 325
 326    Unlike get_prev_frame, this function always tries to unwind the
 327    frame.  */
 328 extern struct frame_info *get_prev_frame_always (struct frame_info *);
 329
 330 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
 331    is not found.  */
 332 extern struct frame_info *frame_find_by_id (struct frame_id id);
 333
 334 /* Base attributes of a frame: */
 335
 336 /* The frame's `resume' address.  Where the program will resume in
 337    this frame.
 338
 339    This replaced: frame->pc; */
 340 extern CORE_ADDR get_frame_pc (struct frame_info *);
 341
 342 /* Same as get_frame_pc, but return a boolean indication of whether
 343    the PC is actually available, instead of throwing an error.  */
 344
 345 extern int get_frame_pc_if_available (struct frame_info *frame,
 346                                       CORE_ADDR *pc);
 347
 348 /* An address (not necessarily aligned to an instruction boundary)
 349    that falls within THIS frame's code block.
 350
 351    When a function call is the last statement in a block, the return
 352    address for the call may land at the start of the next block.
 353    Similarly, if a no-return function call is the last statement in
 354    the function, the return address may end up pointing beyond the
 355    function, and possibly at the start of the next function.
 356
 357    These methods make an allowance for this.  For call frames, this
 358    function returns the frame's PC-1 which "should" be an address in
 359    the frame's block.  */
 360
 361 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
 362
 363 /* Same as get_frame_address_in_block, but returns a boolean
 364    indication of whether the frame address is determinable (when the
 365    PC is unavailable, it will not be), instead of possibly throwing an
 366    error trying to read an unavailable PC.  */
 367
 368 extern int
 369   get_frame_address_in_block_if_available (struct frame_info *this_frame,
 370                                            CORE_ADDR *pc);
 371
 372 /* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
 373    known as top-of-stack.  */
 374
 375 extern CORE_ADDR get_frame_sp (struct frame_info *);
 376
 377 /* Following on from the `resume' address.  Return the entry point
 378    address of the function containing that resume address, or zero if
 379    that function isn't known.  */
 380 extern CORE_ADDR get_frame_func (struct frame_info *fi);
 381
 382 /* Same as get_frame_func, but returns a boolean indication of whether
 383    the frame function is determinable (when the PC is unavailable, it
 384    will not be), instead of possibly throwing an error trying to read
 385    an unavailable PC.  */
 386
 387 extern int get_frame_func_if_available (struct frame_info *fi, CORE_ADDR *);
 388
 389 /* Closely related to the resume address, various symbol table
 390    attributes that are determined by the PC.  Note that for a normal
 391    frame, the PC refers to the resume address after the return, and
 392    not the call instruction.  In such a case, the address is adjusted
 393    so that it (approximately) identifies the call site (and not the
 394    return site).
 395
 396    NOTE: cagney/2002-11-28: The frame cache could be used to cache the
 397    computed value.  Working on the assumption that the bottle-neck is
 398    in the single step code, and that code causes the frame cache to be
 399    constantly flushed, caching things in a frame is probably of little
 400    benefit.  As they say `show us the numbers'.
 401
 402    NOTE: cagney/2002-11-28: Plenty more where this one came from:
 403    find_frame_block(), find_frame_partial_function(),
 404    find_frame_symtab(), find_frame_function().  Each will need to be
 405    carefully considered to determine if the real intent was for it to
 406    apply to the PC or the adjusted PC.  */
 407 extern void find_frame_sal (struct frame_info *frame,
 408                             struct symtab_and_line *sal);
 409
 410 /* Set the current source and line to the location given by frame
 411    FRAME, if possible.  */
 412
 413 void set_current_sal_from_frame (struct frame_info *);
 414
 415 /* Return the frame base (what ever that is) (DEPRECATED).
 416
 417    Old code was trying to use this single method for two conflicting
 418    purposes.  Such code needs to be updated to use either of:
 419
 420    get_frame_id: A low level frame unique identifier, that consists of
 421    both a stack and a function address, that can be used to uniquely
 422    identify a frame.  This value is determined by the frame's
 423    low-level unwinder, the stack part [typically] being the
 424    top-of-stack of the previous frame, and the function part being the
 425    function's start address.  Since the correct identification of a
 426    frameless function requires both a stack and function address,
 427    the old get_frame_base method was not sufficient.
 428
 429    get_frame_base_address: get_frame_locals_address:
 430    get_frame_args_address: A set of high-level debug-info dependant
 431    addresses that fall within the frame.  These addresses almost
 432    certainly will not match the stack address part of a frame ID (as
 433    returned by get_frame_base).
 434
 435    This replaced: frame->frame; */
 436
 437 extern CORE_ADDR get_frame_base (struct frame_info *);
 438
 439 /* Return the per-frame unique identifer.  Can be used to relocate a
 440    frame after a frame cache flush (and other similar operations).  If
 441    FI is NULL, return the null_frame_id.
 442
 443    NOTE: kettenis/20040508: These functions return a structure.  On
 444    platforms where structures are returned in static storage (vax,
 445    m68k), this may trigger compiler bugs in code like:
 446
 447    if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
 448
 449    where the return value from the first get_frame_id (l) gets
 450    overwritten by the second get_frame_id (r).  Please avoid writing
 451    code like this.  Use code like:
 452
 453    struct frame_id id = get_frame_id (l);
 454    if (frame_id_eq (id, get_frame_id (r)))
 455
 456    instead, since that avoids the bug.  */
 457 extern struct frame_id get_frame_id (struct frame_info *fi);
 458 extern struct frame_id get_stack_frame_id (struct frame_info *fi);
 459 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
 460
 461 /* Assuming that a frame is `normal', return its base-address, or 0 if
 462    the information isn't available.  NOTE: This address is really only
 463    meaningful to the frame's high-level debug info.  */
 464 extern CORE_ADDR get_frame_base_address (struct frame_info *);
 465
 466 /* Assuming that a frame is `normal', return the base-address of the
 467    local variables, or 0 if the information isn't available.  NOTE:
 468    This address is really only meaningful to the frame's high-level
 469    debug info.  Typically, the argument and locals share a single
 470    base-address.  */
 471 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
 472
 473 /* Assuming that a frame is `normal', return the base-address of the
 474    parameter list, or 0 if that information isn't available.  NOTE:
 475    This address is really only meaningful to the frame's high-level
 476    debug info.  Typically, the argument and locals share a single
 477    base-address.  */
 478 extern CORE_ADDR get_frame_args_address (struct frame_info *);
 479
 480 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
 481    for an invalid frame).  */
 482 extern int frame_relative_level (struct frame_info *fi);
 483
 484 /* Return the frame's type.  */
 485
 486 extern enum frame_type get_frame_type (struct frame_info *);
 487
 488 /* Return the frame's program space.  */
 489 extern struct program_space *get_frame_program_space (struct frame_info *);
 490
 491 /* Unwind THIS frame's program space from the NEXT frame.  */
 492 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 493
 494 /* Return the frame's address space.  */
 495 extern struct address_space *get_frame_address_space (struct frame_info *);
 496
 497 /* For frames where we can not unwind further, describe why.  */
 498
 499 enum unwind_stop_reason
 500   {
 501 #define SET(name, description) name,
 502 #define FIRST_ENTRY(name) UNWIND_FIRST = name,
 503 #define LAST_ENTRY(name) UNWIND_LAST = name,
 504 #define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
 505
 506 #include "unwind_stop_reasons.def"
 507 #undef SET
 508 #undef FIRST_ENTRY
 509 #undef LAST_ENTRY
 510 #undef FIRST_ERROR
 511   };
 512
 513 /* Return the reason why we can't unwind past this frame.  */
 514
 515 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
 516
 517 /* Translate a reason code to an informative string.  This converts the
 518    generic stop reason codes into a generic string describing the code.
 519    For a possibly frame specific string explaining the stop reason, use
 520    FRAME_STOP_REASON_STRING instead.  */
 521
 522 const char *unwind_stop_reason_to_string (enum unwind_stop_reason);
 523
 524 /* Return a possibly frame specific string explaining why the unwind
 525    stopped here.  E.g., if unwinding tripped on a memory error, this
 526    will return the error description string, which includes the address
 527    that we failed to access.  If there's no specific reason stored for
 528    a frame then a generic reason string will be returned.
 529
 530    Should only be called for frames that don't have a previous frame.  */
 531
 532 const char *frame_stop_reason_string (struct frame_info *);
 533
 534 /* Unwind the stack frame so that the value of REGNUM, in the previous
 535    (up, older) frame is returned.  If VALUEP is NULL, don't
 536    fetch/compute the value.  Instead just return the location of the
 537    value.  */
 538 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 539                                    int *optimizedp, int *unavailablep,
 540                                    enum lval_type *lvalp,
 541                                    CORE_ADDR *addrp, int *realnump,
 542                                    gdb_byte *valuep);
 543
 544 /* Fetch a register from this, or unwind a register from the next
 545    frame.  Note that the get_frame methods are wrappers to
 546    frame->next->unwind.  They all [potentially] throw an error if the
 547    fetch fails.  The value methods never return NULL, but usually
 548    do return a lazy value.  */
 549
 550 extern void frame_unwind_register (struct frame_info *frame,
 551                                    int regnum, gdb_byte *buf);
 552 extern void get_frame_register (struct frame_info *frame,
 553                                 int regnum, gdb_byte *buf);
 554
 555 struct value *frame_unwind_register_value (struct frame_info *frame,
 556                                            int regnum);
 557 struct value *get_frame_register_value (struct frame_info *frame,
 558                                         int regnum);
 559
 560 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 561                                              int regnum);
 562 extern LONGEST get_frame_register_signed (struct frame_info *frame,
 563                                           int regnum);
 564 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
 565                                                int regnum);
 566 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
 567                                              int regnum);
 568
 569 /* Read a register from this, or unwind a register from the next
 570    frame.  Note that the read_frame methods are wrappers to
 571    get_frame_register_value, that do not throw if the result is
 572    optimized out or unavailable.  */
 573
 574 extern int read_frame_register_unsigned (struct frame_info *frame,
 575                                          int regnum, ULONGEST *val);
 576
 577 /* Get the value of the register that belongs to this FRAME.  This
 578    function is a wrapper to the call sequence ``frame_register_unwind
 579    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 580    VALUEP is NULL, the registers value is not fetched/computed.  */
 581
 582 extern void frame_register (struct frame_info *frame, int regnum,
 583                             int *optimizedp, int *unavailablep,
 584                             enum lval_type *lvalp,
 585                             CORE_ADDR *addrp, int *realnump,
 586                             gdb_byte *valuep);
 587
 588 /* The reverse.  Store a register value relative to the specified
 589    frame.  Note: this call makes the frame's state undefined.  The
 590    register and frame caches must be flushed.  */
 591 extern void put_frame_register (struct frame_info *frame, int regnum,
 592                                 const gdb_byte *buf);
 593
 594 /* Read LEN bytes from one or multiple registers starting with REGNUM
 595    in frame FRAME, starting at OFFSET, into BUF.  If the register
 596    contents are optimized out or unavailable, set *OPTIMIZEDP,
 597    *UNAVAILABLEP accordingly.  */
 598 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
 599                                      CORE_ADDR offset, int len,
 600                                      gdb_byte *myaddr,
 601                                      int *optimizedp, int *unavailablep);
 602
 603 /* Write LEN bytes to one or multiple registers starting with REGNUM
 604    in frame FRAME, starting at OFFSET, into BUF.  */
 605 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
 606                                       CORE_ADDR offset, int len,
 607                                       const gdb_byte *myaddr);
 608
 609 /* Unwind the PC.  Strictly speaking return the resume address of the
 610    calling frame.  For GDB, `pc' is the resume address and not a
 611    specific register.  */
 612
 613 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
 614
 615 /* Discard the specified frame.  Restoring the registers to the state
 616    of the caller.  */
 617 extern void frame_pop (struct frame_info *frame);
 618
 619 /* Return memory from the specified frame.  A frame knows its thread /
 620    LWP and hence can find its way down to a target.  The assumption
 621    here is that the current and previous frame share a common address
 622    space.
 623
 624    If the memory read fails, these methods throw an error.
 625
 626    NOTE: cagney/2003-06-03: Should there be unwind versions of these
 627    methods?  That isn't clear.  Can code, for instance, assume that
 628    this and the previous frame's memory or architecture are identical?
 629    If architecture / memory changes are always separated by special
 630    adaptor frames this should be ok.  */
 631
 632 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
 633                               gdb_byte *buf, int len);
 634 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
 635                                         CORE_ADDR memaddr, int len);
 636 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
 637                                            CORE_ADDR memaddr, int len);
 638
 639 /* Same as above, but return non-zero when the entire memory read
 640    succeeds, zero otherwize.  */
 641 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 642                                      CORE_ADDR addr, gdb_byte *buf, int len);
 643
 644 /* Return this frame's architecture.  */
 645 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 646
 647 /* Return the previous frame's architecture.  */
 648 extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
 649
 650 /* Return the previous frame's architecture, skipping inline functions.  */
 651 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 652
 653
 654 /* Values for the source flag to be used in print_frame_info_base().  */
 655 enum print_what
 656   {
 657     /* Print only the source line, like in stepi.  */
 658     SRC_LINE = -1,
 659     /* Print only the location, i.e. level, address (sometimes)
 660        function, args, file, line, line num.  */
 661     LOCATION,
 662     /* Print both of the above.  */
 663     SRC_AND_LOC,
 664     /* Print location only, but always include the address.  */
 665     LOC_AND_ADDRESS
 666   };
 667
 668 /* Allocate zero initialized memory from the frame cache obstack.
 669    Appendices to the frame info (such as the unwind cache) should
 670    allocate memory using this method.  */
 671
 672 extern void *frame_obstack_zalloc (unsigned long size);
 673 #define FRAME_OBSTACK_ZALLOC(TYPE) \
 674   ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
 675 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) \
 676   ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
 677
 678 /* Create a regcache, and copy the frame's registers into it.  */
 679 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 680
 681 extern const struct block *get_frame_block (struct frame_info *,
 682                                             CORE_ADDR *addr_in_block);
 683
 684 /* Return the `struct block' that belongs to the selected thread's
 685    selected frame.  If the inferior has no state, return NULL.
 686
 687    NOTE: cagney/2002-11-29:
 688
 689    No state?  Does the inferior have any execution state (a core file
 690    does, an executable does not).  At present the code tests
 691    `target_has_stack' but I'm left wondering if it should test
 692    `target_has_registers' or, even, a merged target_has_state.
 693
 694    Should it look at the most recently specified SAL?  If the target
 695    has no state, should this function try to extract a block from the
 696    most recently selected SAL?  That way `list foo' would give it some
 697    sort of reference point.  Then again, perhaps that would confuse
 698    things.
 699
 700    Calls to this function can be broken down into two categories: Code
 701    that uses the selected block as an additional, but optional, data
 702    point; Code that uses the selected block as a prop, when it should
 703    have the relevant frame/block/pc explicitly passed in.
 704
 705    The latter can be eliminated by correctly parameterizing the code,
 706    the former though is more interesting.  Per the "address" command,
 707    it occurs in the CLI code and makes it possible for commands to
 708    work, even when the inferior has no state.  */
 709
 710 extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 711
 712 extern struct symbol *get_frame_function (struct frame_info *);
 713
 714 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 715
 716 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 717
 718 /* Wrapper over print_stack_frame modifying current_uiout with UIOUT for
 719    the function call.  */
 720
 721 extern void print_stack_frame_to_uiout (struct ui_out *uiout,
 722                                         struct frame_info *, int print_level,
 723                                         enum print_what print_what,
 724                                         int set_current_sal);
 725
 726 extern void print_stack_frame (struct frame_info *, int print_level,
 727                                enum print_what print_what,
 728                                int set_current_sal);
 729
 730 extern void print_frame_info (struct frame_info *, int print_level,
 731                               enum print_what print_what, int args,
 732                               int set_current_sal);
 733
 734 extern struct frame_info *block_innermost_frame (const struct block *);
 735
 736 extern int deprecated_frame_register_read (struct frame_info *frame, int regnum,
 737                                 gdb_byte *buf);
 738
 739 /* From stack.c.  */
 740
 741 extern const char print_entry_values_no[];
 742 extern const char print_entry_values_only[];
 743 extern const char print_entry_values_preferred[];
 744 extern const char print_entry_values_if_needed[];
 745 extern const char print_entry_values_both[];
 746 extern const char print_entry_values_compact[];
 747 extern const char print_entry_values_default[];
 748 extern const char *print_entry_values;
 749
 750 /* Inferior function parameter value read in from a frame.  */
 751
 752 struct frame_arg
 753 {
 754   /* Symbol for this parameter used for example for its name.  */
 755   struct symbol *sym;
 756
 757   /* Value of the parameter.  It is NULL if ERROR is not NULL; if both VAL and
 758      ERROR are NULL this parameter's value should not be printed.  */
 759   struct value *val;
 760
 761   /* String containing the error message, it is more usually NULL indicating no
 762      error occured reading this parameter.  */
 763   char *error;
 764
 765   /* One of the print_entry_values_* entries as appropriate specifically for
 766      this frame_arg.  It will be different from print_entry_values.  With
 767      print_entry_values_no this frame_arg should be printed as a normal
 768      parameter.  print_entry_values_only says it should be printed as entry
 769      value parameter.  print_entry_values_compact says it should be printed as
 770      both as a normal parameter and entry values parameter having the same
 771      value - print_entry_values_compact is not permitted fi ui_out_is_mi_like_p
 772      (in such case print_entry_values_no and print_entry_values_only is used
 773      for each parameter kind specifically.  */
 774   const char *entry_kind;
 775 };
 776
 777 extern void read_frame_arg (struct symbol *sym, struct frame_info *frame,
 778                             struct frame_arg *argp,
 779                             struct frame_arg *entryargp);
 780 extern void read_frame_local (struct symbol *sym, struct frame_info *frame,
 781                               struct frame_arg *argp);
 782
 783 extern void args_info (char *, int);
 784
 785 extern void locals_info (char *, int);
 786
 787 extern void return_command (char *, int);
 788
 789 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
 790    Return a cleanup which should be called if unwinding fails, and
 791    discarded if it succeeds.  */
 792
 793 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
 794                                            const struct frame_unwind *unwind);
 795
 796 /* Notes (cagney/2002-11-27, drow/2003-09-06):
 797
 798    You might think that calls to this function can simply be replaced by a
 799    call to get_selected_frame().
 800
 801    Unfortunately, it isn't that easy.
 802
 803    The relevant code needs to be audited to determine if it is
 804    possible (or practical) to instead pass the applicable frame in as a
 805    parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
 806    the deprecated_selected_frame global, while its replacement,
 807    PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
 808    The only real exceptions occur at the edge (in the CLI code) where
 809    user commands need to pick up the selected frame before proceeding.
 810
 811    There are also some functions called with a NULL frame meaning either "the
 812    program is not running" or "use the selected frame".
 813
 814    This is important.  GDB is trying to stamp out the hack:
 815
 816    saved_frame = deprecated_safe_get_selected_frame ();
 817    select_frame (...);
 818    hack_using_global_selected_frame ();
 819    select_frame (saved_frame);
 820
 821    Take care!
 822
 823    This function calls get_selected_frame if the inferior should have a
 824    frame, or returns NULL otherwise.  */
 825
 826 extern struct frame_info *deprecated_safe_get_selected_frame (void);
 827
 828 /* Create a frame using the specified BASE and PC.  */
 829
 830 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
 831
 832 /* Return true if the frame unwinder for frame FI is UNWINDER; false
 833    otherwise.  */
 834
 835 extern int frame_unwinder_is (struct frame_info *fi,
 836                               const struct frame_unwind *unwinder);
 837
 838 /* Return the language of FRAME.  */
 839
 840 extern enum language get_frame_language (struct frame_info *frame);
 841
 842 /* Return the first non-tailcall frame above FRAME or FRAME if it is not a
 843    tailcall frame.  Return NULL if FRAME is the start of a tailcall-only
 844    chain.  */
 845
 846 extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);
 847
 848 /* Return the first frame above FRAME or FRAME of which the code is
 849    writable.  */
 850
 851 extern struct frame_info *skip_unwritable_frames (struct frame_info *frame);
 852
 853 #endif /* !defined (FRAME_H)  */