Subversion Repositories openrisc_2011-10-31

/* Definitions for dealing with stack frames, for GDB, the GNU debugger.

   Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,

   1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009, 2010

   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#if !defined (FRAME_H)

#define FRAME_H 1

/* The following is the intended naming schema for frame functions.

   It isn't 100% consistent, but it is aproaching that.  Frame naming

   schema:

   Prefixes:

   get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly

   equivalent to THIS->next->unwind->what)

   frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT

   frame.

   frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's

   real caller.  Any inlined functions in NEXT's stack frame are

   skipped.  Use these to ignore any potentially inlined functions,

   e.g. inlined into the first instruction of a library trampoline.

   get_stack_frame_WHAT...(): Get WHAT for THIS frame, but if THIS is

   inlined, skip to the containing stack frame.

   put_frame_WHAT...(): Put a value into this frame (unsafe, need to

   invalidate the frame / regcache afterwards) (better name more

   strongly hinting at its unsafeness)

   safe_....(): Safer version of various functions, doesn't throw an

   error (leave this for later?).  Returns non-zero / non-NULL if the

   request succeeds, zero / NULL otherwize.

   Suffixes:

   void /frame/_WHAT(): Read WHAT's value into the buffer parameter.

   ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the

   alternative is *frame_unsigned_WHAT).

   LONGEST /frame/_WHAT_signed(): Return WHAT signed value.

   What:

   /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return

   *memory.

   /frame/_register* (frame, regnum [, buf]): extract/return register.

   CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most

   stack *address, ...

   */

struct symtab_and_line;

struct frame_unwind;

struct frame_base;

struct block;

struct gdbarch;

struct ui_file;

/* The frame object.  */

struct frame_info;

/* The frame object's ID.  This provides a per-frame unique identifier

   that can be used to relocate a `struct frame_info' after a target

   resume or a frame cache destruct.  It of course assumes that the

   inferior hasn't unwound the stack past that frame.  */

struct frame_id

{

  /* The frame's stack address.  This shall be constant through out

     the lifetime of a frame.  Note that this requirement applies to

     not just the function body, but also the prologue and (in theory

     at least) the epilogue.  Since that value needs to fall either on

     the boundary, or within the frame's address range, the frame's

     outer-most address (the inner-most address of the previous frame)

     is used.  Watch out for all the legacy targets that still use the

     function pointer register or stack pointer register.  They are

     wrong.

     This field is valid only if stack_addr_p is true.  Otherwise, this

     frame represents the null frame.  */

  CORE_ADDR stack_addr;

  /* The frame's code address.  This shall be constant through out the

     lifetime of the frame.  While the PC (a.k.a. resume address)

     changes as the function is executed, this code address cannot.

     Typically, it is set to the address of the entry point of the

     frame's function (as returned by get_frame_func).

     For inlined functions (INLINE_DEPTH != 0), this is the address of

     the first executed instruction in the block corresponding to the

     inlined function.

     This field is valid only if code_addr_p is true.  Otherwise, this

     frame is considered to have a wildcard code address, i.e. one that

     matches every address value in frame comparisons.  */

  CORE_ADDR code_addr;

  /* The frame's special address.  This shall be constant through out the

     lifetime of the frame.  This is used for architectures that may have

     frames that do not change the stack but are still distinct and have

     some form of distinct identifier (e.g. the ia64 which uses a 2nd

     stack for registers).  This field is treated as unordered - i.e. will

     not be used in frame ordering comparisons.

     This field is valid only if special_addr_p is true.  Otherwise, this

     frame is considered to have a wildcard special address, i.e. one that

     matches every address value in frame comparisons.  */

  CORE_ADDR special_addr;

  /* Flags to indicate the above fields have valid contents.  */

  unsigned int stack_addr_p : 1;

  unsigned int code_addr_p : 1;

  unsigned int special_addr_p : 1;

  /* The inline depth of this frame.  A frame representing a "called"

     inlined function will have this set to a nonzero value.  */

  int inline_depth;

};

/* Methods for constructing and comparing Frame IDs.  */

/* For convenience.  All fields are zero.  This means "there is no frame".  */

extern const struct frame_id null_frame_id;

/* This means "there is no frame ID, but there is a frame".  It should be

   replaced by best-effort frame IDs for the outermost frame, somehow.

   The implementation is only special_addr_p set.  */

extern const struct frame_id outer_frame_id;

/* Flag to control debugging.  */

extern int frame_debug;

/* Construct a frame ID.  The first parameter is the frame's constant

   stack address (typically the outer-bound), and the second the

   frame's constant code address (typically the entry point).

   The special identifier address is set to indicate a wild card.  */

extern struct frame_id frame_id_build (CORE_ADDR stack_addr,

                                       CORE_ADDR code_addr);

/* Construct a special frame ID.  The first parameter is the frame's constant

   stack address (typically the outer-bound), the second is the

   frame's constant code address (typically the entry point),

   and the third parameter is the frame's special identifier address. */

extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,

                                               CORE_ADDR code_addr,

                                               CORE_ADDR special_addr);

/* Construct a wild card frame ID.  The parameter is the frame's constant

   stack address (typically the outer-bound).  The code address as well

   as the special identifier address are set to indicate wild cards.  */

extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);

/* Returns non-zero when L is a valid frame (a valid frame has a

   non-zero .base).  The outermost frame is valid even without an

   ID.  */

extern int frame_id_p (struct frame_id l);

/* Returns non-zero when L is a valid frame representing an inlined

   function.  */

extern int frame_id_inlined_p (struct frame_id l);

/* Returns non-zero when L and R identify the same frame, or, if

   either L or R have a zero .func, then the same frame base.  */

extern int frame_id_eq (struct frame_id l, struct frame_id r);

/* Write the internal representation of a frame ID on the specified

   stream.  */

extern void fprint_frame_id (struct ui_file *file, struct frame_id id);

/* Frame types.  Some are real, some are signal trampolines, and some

   are completely artificial (dummy).  */

enum frame_type

{

  /* A true stack frame, created by the target program during normal

     execution.  */

  NORMAL_FRAME,

  /* A fake frame, created by GDB when performing an inferior function

     call.  */

  DUMMY_FRAME,

  /* A frame representing an inlined function, associated with an

     upcoming (next, inner, younger) NORMAL_FRAME.  */

  INLINE_FRAME,

  /* In a signal handler, various OSs handle this in various ways.

     The main thing is that the frame may be far from normal.  */

  SIGTRAMP_FRAME,

  /* Fake frame representing a cross-architecture call.  */

  ARCH_FRAME,

  /* Sentinel or registers frame.  This frame obtains register values

     direct from the inferior's registers.  */

  SENTINEL_FRAME

};

/* For every stopped thread, GDB tracks two frames: current and

   selected.  Current frame is the inner most frame of the selected

   thread.  Selected frame is the one being examined by the the GDB

   CLI (selected using `up', `down', ...).  The frames are created

   on-demand (via get_prev_frame()) and then held in a frame cache.  */

/* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the

   sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's

   selected frame.  At present GDB only tracks the selected frame of

   the current thread.  But be warned, that might change.  */

/* FIXME: cagney/2002-11-14: At any time, only one thread's selected

   and current frame can be active.  Switching threads causes gdb to

   discard all that cached frame information.  Ulgh!  Instead, current

   and selected frame should be bound to a thread.  */

/* On demand, create the inner most frame using information found in

   the inferior.  If the inner most frame can't be created, throw an

   error.  */

extern struct frame_info *get_current_frame (void);

/* Does the current target interface have enough state to be able to

   query the current inferior for frame info, and is the inferior in a

   state where that is possible?  */

extern int has_stack_frames (void);

/* Invalidates the frame cache (this function should have been called

   invalidate_cached_frames).

   FIXME: cagney/2002-11-28: There should be two methods: one that

   reverts the thread's selected frame back to current frame (for when

   the inferior resumes) and one that does not (for when the user

   modifies the target invalidating the frame cache).  */

extern void reinit_frame_cache (void);

/* On demand, create the selected frame and then return it.  If the

   selected frame can not be created, this function prints then throws

   an error.  When MESSAGE is non-NULL, use it for the error message,

   otherwize use a generic error message.  */

/* FIXME: cagney/2002-11-28: At present, when there is no selected

   frame, this function always returns the current (inner most) frame.

   It should instead, when a thread has previously had its frame

   selected (but not resumed) and the frame cache invalidated, find

   and then return that thread's previously selected frame.  */

extern struct frame_info *get_selected_frame (const char *message);

/* Select a specific frame.  NULL, apparently implies re-select the

   inner most frame.  */

extern void select_frame (struct frame_info *);

/* Given a FRAME, return the next (more inner, younger) or previous

   (more outer, older) frame.  */

extern struct frame_info *get_prev_frame (struct frame_info *);

extern struct frame_info *get_next_frame (struct frame_info *);

/* Given a frame's ID, relocate the frame.  Returns NULL if the frame

   is not found.  */

extern struct frame_info *frame_find_by_id (struct frame_id id);

/* Base attributes of a frame: */

/* The frame's `resume' address.  Where the program will resume in

   this frame.

   This replaced: frame->pc; */

extern CORE_ADDR get_frame_pc (struct frame_info *);

/* An address (not necessarily aligned to an instruction boundary)

   that falls within THIS frame's code block.

   When a function call is the last statement in a block, the return

   address for the call may land at the start of the next block.

   Similarly, if a no-return function call is the last statement in

   the function, the return address may end up pointing beyond the

   function, and possibly at the start of the next function.

   These methods make an allowance for this.  For call frames, this

   function returns the frame's PC-1 which "should" be an address in

   the frame's block.  */

extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);

/* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly

   known as top-of-stack.  */

extern CORE_ADDR get_frame_sp (struct frame_info *);

/* Following on from the `resume' address.  Return the entry point

   address of the function containing that resume address, or zero if

   that function isn't known.  */

extern CORE_ADDR get_frame_func (struct frame_info *fi);

/* Closely related to the resume address, various symbol table

   attributes that are determined by the PC.  Note that for a normal

   frame, the PC refers to the resume address after the return, and

   not the call instruction.  In such a case, the address is adjusted

   so that it (approximately) identifies the call site (and not the

   return site).

   NOTE: cagney/2002-11-28: The frame cache could be used to cache the

   computed value.  Working on the assumption that the bottle-neck is

   in the single step code, and that code causes the frame cache to be

   constantly flushed, caching things in a frame is probably of little

   benefit.  As they say `show us the numbers'.

   NOTE: cagney/2002-11-28: Plenty more where this one came from:

   find_frame_block(), find_frame_partial_function(),

   find_frame_symtab(), find_frame_function().  Each will need to be

   carefully considered to determine if the real intent was for it to

   apply to the PC or the adjusted PC.  */

extern void find_frame_sal (struct frame_info *frame,

                            struct symtab_and_line *sal);

/* Set the current source and line to the location given by frame

   FRAME, if possible.  When CENTER is true, adjust so the relevant

   line is in the center of the next 'list'.  */

void set_current_sal_from_frame (struct frame_info *, int);

/* Return the frame base (what ever that is) (DEPRECATED).

   Old code was trying to use this single method for two conflicting

   purposes.  Such code needs to be updated to use either of:

   get_frame_id: A low level frame unique identifier, that consists of

   both a stack and a function address, that can be used to uniquely

   identify a frame.  This value is determined by the frame's

   low-level unwinder, the stack part [typically] being the

   top-of-stack of the previous frame, and the function part being the

   function's start address.  Since the correct identification of a

   frameless function requires both the a stack and function address,

   the old get_frame_base method was not sufficient.

   get_frame_base_address: get_frame_locals_address:

   get_frame_args_address: A set of high-level debug-info dependant

   addresses that fall within the frame.  These addresses almost

   certainly will not match the stack address part of a frame ID (as

   returned by get_frame_base).

   This replaced: frame->frame; */

extern CORE_ADDR get_frame_base (struct frame_info *);

/* Return the per-frame unique identifer.  Can be used to relocate a

   frame after a frame cache flush (and other similar operations).  If

   FI is NULL, return the null_frame_id.

   NOTE: kettenis/20040508: These functions return a structure.  On

   platforms where structures are returned in static storage (vax,

   m68k), this may trigger compiler bugs in code like:

   if (frame_id_eq (get_frame_id (l), get_frame_id (r)))

   where the return value from the first get_frame_id (l) gets

   overwritten by the second get_frame_id (r).  Please avoid writing

   code like this.  Use code like:

   struct frame_id id = get_frame_id (l);

   if (frame_id_eq (id, get_frame_id (r)))

   instead, since that avoids the bug.  */

extern struct frame_id get_frame_id (struct frame_info *fi);

extern struct frame_id get_stack_frame_id (struct frame_info *fi);

extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);

/* Assuming that a frame is `normal', return its base-address, or 0 if

   the information isn't available.  NOTE: This address is really only

   meaningful to the frame's high-level debug info.  */

extern CORE_ADDR get_frame_base_address (struct frame_info *);

/* Assuming that a frame is `normal', return the base-address of the

   local variables, or 0 if the information isn't available.  NOTE:

   This address is really only meaningful to the frame's high-level

   debug info.  Typically, the argument and locals share a single

   base-address.  */

extern CORE_ADDR get_frame_locals_address (struct frame_info *);

/* Assuming that a frame is `normal', return the base-address of the

   parameter list, or 0 if that information isn't available.  NOTE:

   This address is really only meaningful to the frame's high-level

   debug info.  Typically, the argument and locals share a single

   base-address.  */

extern CORE_ADDR get_frame_args_address (struct frame_info *);

/* The frame's level: 0 for innermost, 1 for its caller, ...; or -1

   for an invalid frame).  */

extern int frame_relative_level (struct frame_info *fi);

/* Return the frame's type.  */

extern enum frame_type get_frame_type (struct frame_info *);

/* Return the frame's program space.  */

extern struct program_space *get_frame_program_space (struct frame_info *);

/* Unwind THIS frame's program space from the NEXT frame.  */

extern struct program_space *frame_unwind_program_space (struct frame_info *);

/* Return the frame's address space.  */

extern struct address_space *get_frame_address_space (struct frame_info *);

/* For frames where we can not unwind further, describe why.  */

enum unwind_stop_reason

  {

    /* No particular reason; either we haven't tried unwinding yet,

       or we didn't fail.  */

    UNWIND_NO_REASON,

    /* The previous frame's analyzer returns an invalid result

       from this_id.

       FIXME drow/2006-08-16: This is how GDB used to indicate end of

       stack.  We should migrate to a model where frames always have a

       valid ID, and this becomes not just an error but an internal

       error.  But that's a project for another day.  */

    UNWIND_NULL_ID,

    /* All the conditions after this point are considered errors;

       abnormal stack termination.  If a backtrace stops for one

       of these reasons, we'll let the user know.  This marker

       is not a valid stop reason.  */

    UNWIND_FIRST_ERROR,

    /* This frame ID looks like it ought to belong to a NEXT frame,

       but we got it for a PREV frame.  Normally, this is a sign of

       unwinder failure.  It could also indicate stack corruption.  */

    UNWIND_INNER_ID,

    /* This frame has the same ID as the previous one.  That means

       that unwinding further would almost certainly give us another

       frame with exactly the same ID, so break the chain.  Normally,

       this is a sign of unwinder failure.  It could also indicate

       stack corruption.  */

    UNWIND_SAME_ID,

    /* The frame unwinder didn't find any saved PC, but we needed

       one to unwind further.  */

    UNWIND_NO_SAVED_PC,

  };

/* Return the reason why we can't unwind past this frame.  */

enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);

/* Translate a reason code to an informative string.  */

const char *frame_stop_reason_string (enum unwind_stop_reason);

/* Unwind the stack frame so that the value of REGNUM, in the previous

   (up, older) frame is returned.  If VALUEP is NULL, don't

   fetch/compute the value.  Instead just return the location of the

   value.  */

extern void frame_register_unwind (struct frame_info *frame, int regnum,

                                   int *optimizedp, enum lval_type *lvalp,

                                   CORE_ADDR *addrp, int *realnump,

                                   gdb_byte *valuep);

/* Fetch a register from this, or unwind a register from the next

   frame.  Note that the get_frame methods are wrappers to

   frame->next->unwind.  They all [potentially] throw an error if the

   fetch fails.  The value methods never return NULL, but usually

   do return a lazy value.  */

extern void frame_unwind_register (struct frame_info *frame,

                                   int regnum, gdb_byte *buf);

extern void get_frame_register (struct frame_info *frame,

                                int regnum, gdb_byte *buf);

struct value *frame_unwind_register_value (struct frame_info *frame,

                                           int regnum);

struct value *get_frame_register_value (struct frame_info *frame,

                                        int regnum);

extern LONGEST frame_unwind_register_signed (struct frame_info *frame,

                                             int regnum);

extern LONGEST get_frame_register_signed (struct frame_info *frame,

                                          int regnum);

extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,

                                               int regnum);

extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,

                                             int regnum);

/* Get the value of the register that belongs to this FRAME.  This

   function is a wrapper to the call sequence ``frame_register_unwind

   (get_next_frame (FRAME))''.  As per frame_register_unwind(), if

   VALUEP is NULL, the registers value is not fetched/computed.  */

extern void frame_register (struct frame_info *frame, int regnum,

                            int *optimizedp, enum lval_type *lvalp,

                            CORE_ADDR *addrp, int *realnump,

                            gdb_byte *valuep);

/* The reverse.  Store a register value relative to the specified

   frame.  Note: this call makes the frame's state undefined.  The

   register and frame caches must be flushed.  */

extern void put_frame_register (struct frame_info *frame, int regnum,

                                const gdb_byte *buf);

/* Read LEN bytes from one or multiple registers starting with REGNUM

   in frame FRAME, starting at OFFSET, into BUF.  */

extern int get_frame_register_bytes (struct frame_info *frame, int regnum,

                                     CORE_ADDR offset, int len,

                                     gdb_byte *myaddr);

/* Write LEN bytes to one or multiple registers starting with REGNUM

   in frame FRAME, starting at OFFSET, into BUF.  */

extern void put_frame_register_bytes (struct frame_info *frame, int regnum,

                                      CORE_ADDR offset, int len,

                                      const gdb_byte *myaddr);

/* Unwind the PC.  Strictly speaking return the resume address of the

   calling frame.  For GDB, `pc' is the resume address and not a

   specific register.  */

extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);

/* Discard the specified frame.  Restoring the registers to the state

   of the caller.  */

extern void frame_pop (struct frame_info *frame);

/* Return memory from the specified frame.  A frame knows its thread /

   LWP and hence can find its way down to a target.  The assumption

   here is that the current and previous frame share a common address

   space.

   If the memory read fails, these methods throw an error.

   NOTE: cagney/2003-06-03: Should there be unwind versions of these

   methods?  That isn't clear.  Can code, for instance, assume that

   this and the previous frame's memory or architecture are identical?

   If architecture / memory changes are always separated by special

   adaptor frames this should be ok.  */

extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,

                              gdb_byte *buf, int len);

extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,

                                        CORE_ADDR memaddr, int len);

extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,

                                           CORE_ADDR memaddr, int len);

/* Same as above, but return non-zero when the entire memory read

   succeeds, zero otherwize.  */

extern int safe_frame_unwind_memory (struct frame_info *this_frame,

                                     CORE_ADDR addr, gdb_byte *buf, int len);

/* Return this frame's architecture.  */

extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);

/* Return the previous frame's architecture.  */

extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);

/* Return the previous frame's architecture, skipping inline functions.  */

extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);

/* Values for the source flag to be used in print_frame_info_base().  */

enum print_what

  {

    /* Print only the source line, like in stepi. */

    SRC_LINE = -1,

    /* Print only the location, i.e. level, address (sometimes)

       function, args, file, line, line num. */

    LOCATION,

    /* Print both of the above. */

    SRC_AND_LOC,

    /* Print location only, but always include the address. */

    LOC_AND_ADDRESS

  };

/* Allocate zero initialized memory from the frame cache obstack.

   Appendices to the frame info (such as the unwind cache) should

   allocate memory using this method.  */

extern void *frame_obstack_zalloc (unsigned long size);

#define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))

#define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))

/* Create a regcache, and copy the frame's registers into it.  */

struct regcache *frame_save_as_regcache (struct frame_info *this_frame);

extern struct block *get_frame_block (struct frame_info *,

                                      CORE_ADDR *addr_in_block);

/* Return the `struct block' that belongs to the selected thread's

   selected frame.  If the inferior has no state, return NULL.

   NOTE: cagney/2002-11-29:

   No state?  Does the inferior have any execution state (a core file

   does, an executable does not).  At present the code tests

   `target_has_stack' but I'm left wondering if it should test

   `target_has_registers' or, even, a merged target_has_state.

   Should it look at the most recently specified SAL?  If the target

   has no state, should this function try to extract a block from the

   most recently selected SAL?  That way `list foo' would give it some

   sort of reference point.  Then again, perhaps that would confuse

   things.

   Calls to this function can be broken down into two categories: Code

   that uses the selected block as an additional, but optional, data

   point; Code that uses the selected block as a prop, when it should

   have the relevant frame/block/pc explicitly passed in.

   The latter can be eliminated by correctly parameterizing the code,

   the former though is more interesting.  Per the "address" command,

   it occurs in the CLI code and makes it possible for commands to

   work, even when the inferior has no state.  */

extern struct block *get_selected_block (CORE_ADDR *addr_in_block);

extern struct symbol *get_frame_function (struct frame_info *);

extern CORE_ADDR get_pc_function_start (CORE_ADDR);

extern struct frame_info *find_relative_frame (struct frame_info *, int *);

extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,

                                        enum print_what print_what);

extern void print_stack_frame (struct frame_info *, int print_level,

                               enum print_what print_what);

extern void print_frame_info (struct frame_info *, int print_level,

                              enum print_what print_what, int args);

extern struct frame_info *block_innermost_frame (struct block *);

extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc);

/* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a

   function called get_frame_register_p().  This slightly weird (and

   older) variant of get_frame_register() returns zero (indicating the

   register is unavailable) if either: the register isn't cached; or

   the register has been optimized out.  Problem is, neither check is

   exactly correct.  A register can't be optimized out (it may not

   have been saved as part of a function call); The fact that a

   register isn't in the register cache doesn't mean that the register

   isn't available (it could have been fetched from memory).  */

extern int frame_register_read (struct frame_info *frame, int regnum,

                                gdb_byte *buf);

/* From stack.c.  */

extern void args_info (char *, int);

extern void locals_info (char *, int);

extern void (*deprecated_selected_frame_level_changed_hook) (int);

extern void return_command (char *, int);

/* Set FRAME's unwinder temporarily, so that we can call a sniffer.

   Return a cleanup which should be called if unwinding fails, and

   discarded if it succeeds.  */

struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,

                                           const struct frame_unwind *unwind);

/* Notes (cagney/2002-11-27, drow/2003-09-06):

   You might think that calls to this function can simply be replaced by a

   call to get_selected_frame().

   Unfortunately, it isn't that easy.

   The relevant code needs to be audited to determine if it is

   possible (or practical) to instead pass the applicable frame in as a

   parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on

   the deprecated_selected_frame global, while its replacement,

   PRINT_REGISTERS_INFO(), is parameterized with the selected frame.

   The only real exceptions occur at the edge (in the CLI code) where

   user commands need to pick up the selected frame before proceeding.

   There are also some functions called with a NULL frame meaning either "the

   program is not running" or "use the selected frame".

   This is important.  GDB is trying to stamp out the hack:

   saved_frame = deprecated_safe_get_selected_frame ();

   select_frame (...);

   hack_using_global_selected_frame ();

   select_frame (saved_frame);

   Take care!

   This function calls get_selected_frame if the inferior should have a

   frame, or returns NULL otherwise.  */

extern struct frame_info *deprecated_safe_get_selected_frame (void);

/* Create a frame using the specified BASE and PC.  */

extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);

/* Return true if the frame unwinder for frame FI is UNWINDER; false

   otherwise.  */

extern int frame_unwinder_is (struct frame_info *fi,

                              const struct frame_unwind *unwinder);

#endif /* !defined (FRAME_H)  */