[deliverable/binutils-gdb.git] / gdb / dummy-frame.c

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

   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
   1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */


#include "defs.h"
#include "dummy-frame.h"
#include "regcache.h"
#include "frame.h"
#include "inferior.h"
#include "gdb_assert.h"
#include "frame-unwind.h"

/* Dummy frame.  This saves the processor state just prior to setting
   up the inferior function call.  Older targets save the registers
   on the target stack (but that really slows down function calls).  */

struct dummy_frame
{
  struct dummy_frame *next;

  /* These values belong to the caller (the previous frame, the frame
     that this unwinds back to).  */
  CORE_ADDR pc;
  CORE_ADDR fp;
  CORE_ADDR sp;
  CORE_ADDR top;
  struct frame_id id;
  struct regcache *regcache;

  /* Address range of the call dummy code.  Look for PC in the range
     [LO..HI) (after allowing for DECR_PC_AFTER_BREAK).  */
  CORE_ADDR call_lo;
  CORE_ADDR call_hi;
};

static struct dummy_frame *dummy_frame_stack = NULL;

/* Function: find_dummy_frame(pc, fp, sp)

   Search the stack of dummy frames for one matching the given PC and
   FP/SP.  Unlike pc_in_dummy_frame(), this function doesn't need to
   adjust for DECR_PC_AFTER_BREAK.  This is because it is only legal
   to call this function after the PC has been adjusted.  */

static struct dummy_frame *
find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
  struct dummy_frame *dummyframe;

  for (dummyframe = dummy_frame_stack; dummyframe != NULL;
       dummyframe = dummyframe->next)
    {
      /* Does the PC fall within the dummy frame's breakpoint
         instruction.  If not, discard this one.  */
      if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
	continue;
      /* Does the FP match?  */
      if (dummyframe->top != 0)
	{
	  /* If the target architecture explicitly saved the
	     top-of-stack before the inferior function call, assume
	     that that same architecture will always pass in an FP
	     (frame base) value that eactly matches that saved TOS.
	     Don't check the saved SP and SP as they can lead to false
	     hits.  */
	  if (fp != dummyframe->top)
	    continue;
	}
      else
	{
	  /* An older target that hasn't explicitly or implicitly
             saved the dummy frame's top-of-stack.  Try matching the
             FP against the saved SP and FP.  NOTE: If you're trying
             to fix a problem with GDB not correctly finding a dummy
             frame, check the comments that go with FRAME_ALIGN() and
             SAVE_DUMMY_FRAME_TOS().  */
	  if (fp != dummyframe->fp && fp != dummyframe->sp)
	    continue;
	}
      /* The FP matches this dummy frame.  */
      return dummyframe;
    }

  return NULL;
}

struct dummy_frame *
cached_find_dummy_frame (struct frame_info *frame, void **cache)
{
  if ((*cache) == NULL)
    (*cache) = find_dummy_frame (get_frame_pc (frame), get_frame_base (frame));
  return (*cache);
}

struct regcache *
generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
  struct dummy_frame *dummy = find_dummy_frame (pc, fp);
  if (dummy != NULL)
    return dummy->regcache;
  else
    return NULL;
}

char *
deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
  struct regcache *regcache = generic_find_dummy_frame (pc, fp);
  if (regcache == NULL)
    return NULL;
  return deprecated_grub_regcache_for_registers (regcache);
}

/* Function: pc_in_call_dummy (pc, sp, fp)

   Return true if the PC falls in a dummy frame created by gdb for an
   inferior call.  The code below which allows DECR_PC_AFTER_BREAK is
   for infrun.c, which may give the function a PC without that
   subtracted out.  */

int
generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
{
  return pc_in_dummy_frame (pc);
}

/* Return non-zero if the PC falls in a dummy frame.

   The code below which allows DECR_PC_AFTER_BREAK is for infrun.c,
   which may give the function a PC without that subtracted out.

   FIXME: cagney/2002-11-23: This is silly.  Surely "infrun.c" can
   figure out what the real PC (as in the resume address) is BEFORE
   calling this function (Oh, and I'm not even sure that this function
   is called with an decremented PC, the call to pc_in_call_dummy() in
   that file is conditional on !CALL_DUMMY_BREAKPOINT_OFFSET_P yet
   generic dummy targets set CALL_DUMMY_BREAKPOINT_OFFSET. True?).  */

int
pc_in_dummy_frame (CORE_ADDR pc)
{
  struct dummy_frame *dummyframe;
  for (dummyframe = dummy_frame_stack;
       dummyframe != NULL;
       dummyframe = dummyframe->next)
    {
      if ((pc >= dummyframe->call_lo)
	  && (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
	return 1;
    }
  return 0;
}

/* Function: read_register_dummy 
   Find a saved register from before GDB calls a function in the inferior */

CORE_ADDR
deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
{
  struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);

  if (dummy_regs)
    {
      /* NOTE: cagney/2002-08-12: Replaced a call to
	 regcache_raw_read_as_address() with a call to
	 regcache_cooked_read_unsigned().  The old, ...as_address
	 function was eventually calling extract_unsigned_integer (via
	 extract_address) to unpack the registers value.  The below is
	 doing an unsigned extract so that it is functionally
	 equivalent.  The read needs to be cooked as, otherwise, it
	 will never correctly return the value of a register in the
	 [NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range.  */
      ULONGEST val;
      regcache_cooked_read_unsigned (dummy_regs, regno, &val);
      return val;
    }
  else
    return 0;
}

/* Save all the registers on the dummy frame stack.  Most ports save the
   registers on the target stack.  This results in lots of unnecessary memory
   references, which are slow when debugging via a serial line.  Instead, we
   save all the registers internally, and never write them to the stack.  The
   registers get restored when the called function returns to the entry point,
   where a breakpoint is laying in wait.  */

void
generic_push_dummy_frame (void)
{
  struct dummy_frame *dummy_frame;
  CORE_ADDR fp = get_frame_base (get_current_frame ());

  /* check to see if there are stale dummy frames, 
     perhaps left over from when a longjump took us out of a 
     function that was called by the debugger */

  dummy_frame = dummy_frame_stack;
  while (dummy_frame)
    if (INNER_THAN (dummy_frame->fp, fp))	/* stale -- destroy! */
      {
	dummy_frame_stack = dummy_frame->next;
	regcache_xfree (dummy_frame->regcache);
	xfree (dummy_frame);
	dummy_frame = dummy_frame_stack;
      }
    else
      dummy_frame = dummy_frame->next;

  dummy_frame = xmalloc (sizeof (struct dummy_frame));
  dummy_frame->regcache = regcache_xmalloc (current_gdbarch);

  dummy_frame->pc = read_pc ();
  dummy_frame->sp = read_sp ();
  dummy_frame->top = 0;
  dummy_frame->fp = fp;
  dummy_frame->id = get_frame_id (get_current_frame ());
  regcache_cpy (dummy_frame->regcache, current_regcache);
  dummy_frame->next = dummy_frame_stack;
  dummy_frame_stack = dummy_frame;
}

void
generic_save_dummy_frame_tos (CORE_ADDR sp)
{
  dummy_frame_stack->top = sp;
}

/* Record the upper/lower bounds on the address of the call dummy.  */

void
generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
{
  dummy_frame_stack->call_lo = lo;
  dummy_frame_stack->call_hi = hi;
}

/* Restore the machine state from either the saved dummy stack or a
   real stack frame. */

void
generic_pop_current_frame (void (*popper) (struct frame_info * frame))
{
  struct frame_info *frame = get_current_frame ();
  if (get_frame_type (frame) == DUMMY_FRAME)
    /* NOTE: cagney/2002-22-23: Does this ever occure?  Surely a dummy
       frame will have already been poped by the "infrun.c" code.  */
    generic_pop_dummy_frame ();
  else
    (*popper) (frame);
}

/* Function: pop_dummy_frame
   Restore the machine state from a saved dummy stack frame. */

void
generic_pop_dummy_frame (void)
{
  struct dummy_frame *dummy_frame = dummy_frame_stack;

  /* FIXME: what if the first frame isn't the right one, eg..
     because one call-by-hand function has done a longjmp into another one? */

  if (!dummy_frame)
    error ("Can't pop dummy frame!");
  dummy_frame_stack = dummy_frame->next;
  regcache_cpy (current_regcache, dummy_frame->regcache);
  flush_cached_frames ();

  regcache_xfree (dummy_frame->regcache);
  xfree (dummy_frame);
}

/* Function: fix_call_dummy
   Stub function.  Generic dummy frames typically do not need to fix
   the frame being created */

void
generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
			struct value **args, struct type *type, int gcc_p)
{
  return;
}

/* Given a call-dummy dummy-frame, return the registers.  Here the
   register value is taken from the local copy of the register buffer.  */

static void
dummy_frame_register_unwind (struct frame_info *frame, void **cache,
			     int regnum, int *optimized,
			     enum lval_type *lvalp, CORE_ADDR *addrp,
			     int *realnum, void *bufferp)
{
  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
  gdb_assert (dummy != NULL);

  /* Describe the register's location.  Generic dummy frames always
     have the register value in an ``expression''.  */
  *optimized = 0;
  *lvalp = not_lval;
  *addrp = 0;
  *realnum = -1;

  /* If needed, find and return the value of the register.  */
  if (bufferp != NULL)
    {
      /* Return the actual value.  */
      /* Use the regcache_cooked_read() method so that it, on the fly,
         constructs either a raw or pseudo register from the raw
         register cache.  */
      regcache_cooked_read (dummy->regcache, regnum, bufferp);
    }
}

/* Assuming that FRAME is a dummy, return the resume address for the
   previous frame.  */

static CORE_ADDR
dummy_frame_pc_unwind (struct frame_info *frame,
		       void **cache)
{
  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
  /* Oops!  In a dummy-frame but can't find the stack dummy.  Pretend
     that the frame doesn't unwind.  Should this function instead
     return a has-no-caller indication?  */
  if (dummy == NULL)
    return 0;
  return dummy->pc;
}


/* Assuming that FRAME is a dummy, return the ID of the calling frame
   (the frame that the dummy has the saved state of).  */

static void
dummy_frame_id_unwind (struct frame_info *frame,
		       void **cache,
		       struct frame_id *id)
{
  struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
  /* Oops!  In a dummy-frame but can't find the stack dummy.  Pretend
     that the frame doesn't unwind.  Should this function instead
     return a has-no-caller indication?  */
  if (dummy == NULL)
    (*id) = null_frame_id;
  else
    (*id) = dummy->id;
}

static struct frame_unwind dummy_frame_unwind =
{
  dummy_frame_pc_unwind,
  dummy_frame_id_unwind,
  dummy_frame_register_unwind
};

const struct frame_unwind *
dummy_frame_p (CORE_ADDR pc)
{
  if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
      ? DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)
      : pc_in_dummy_frame (pc))
    return &dummy_frame_unwind;
  else
    return NULL;
}
Commit	Line	Data
9c1412c1 AC	1	/* Code dealing with dummy stack frames, for GDB, the GNU debugger.
	2
	3	Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
	4	1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software
	5	Foundation, Inc.
	6
	7	This file is part of GDB.
	8
	9	This program is free software; you can redistribute it and/or modify
	10	it under the terms of the GNU General Public License as published by
	11	the Free Software Foundation; either version 2 of the License, or
	12	(at your option) any later version.
	13
	14	This program is distributed in the hope that it will be useful,
	15	but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	GNU General Public License for more details.
	18
	19	You should have received a copy of the GNU General Public License
	20	along with this program; if not, write to the Free Software
	21	Foundation, Inc., 59 Temple Place - Suite 330,
	22	Boston, MA 02111-1307, USA. */
	23
	24
	25	#include "defs.h"
	26	#include "dummy-frame.h"
	27	#include "regcache.h"
	28	#include "frame.h"
	29	#include "inferior.h"
	30	#include "gdb_assert.h"
494cca16	31	#include "frame-unwind.h"
9c1412c1 AC	32
	33	/* Dummy frame. This saves the processor state just prior to setting
	34	up the inferior function call. Older targets save the registers
	35	on the target stack (but that really slows down function calls). */
	36
	37	struct dummy_frame
	38	{
	39	struct dummy_frame *next;
	40
f18c5a73 AC	41	/* These values belong to the caller (the previous frame, the frame
f18c5a73 AC	42	that this unwinds back to). */
9c1412c1 AC	43	CORE_ADDR pc;
	44	CORE_ADDR fp;
	45	CORE_ADDR sp;
	46	CORE_ADDR top;
c689142b	47	struct frame_id id;
9c1412c1 AC	48	struct regcache *regcache;
	49
	50	/* Address range of the call dummy code. Look for PC in the range
	51	[LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */
	52	CORE_ADDR call_lo;
	53	CORE_ADDR call_hi;
	54	};
	55
	56	static struct dummy_frame *dummy_frame_stack = NULL;
	57
	58	/* Function: find_dummy_frame(pc, fp, sp)
	59
	60	Search the stack of dummy frames for one matching the given PC and
5e0f933e	61	FP/SP. Unlike pc_in_dummy_frame(), this function doesn't need to
9c1412c1 AC	62	adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
	63	to call this function after the PC has been adjusted. */
	64
8779790c AC	65	static struct dummy_frame *
8779790c AC	66	find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
9c1412c1 AC	67	{
	68	struct dummy_frame *dummyframe;
	69
	70	for (dummyframe = dummy_frame_stack; dummyframe != NULL;
	71	dummyframe = dummyframe->next)
	72	{
	73	/* Does the PC fall within the dummy frame's breakpoint
	74	instruction. If not, discard this one. */
	75	if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
	76	continue;
	77	/* Does the FP match? */
	78	if (dummyframe->top != 0)
	79	{
	80	/* If the target architecture explicitly saved the
	81	top-of-stack before the inferior function call, assume
	82	that that same architecture will always pass in an FP
	83	(frame base) value that eactly matches that saved TOS.
	84	Don't check the saved SP and SP as they can lead to false
	85	hits. */
	86	if (fp != dummyframe->top)
	87	continue;
	88	}
	89	else
	90	{
	91	/* An older target that hasn't explicitly or implicitly
	92	saved the dummy frame's top-of-stack. Try matching the
	93	FP against the saved SP and FP. NOTE: If you're trying
	94	to fix a problem with GDB not correctly finding a dummy
	95	frame, check the comments that go with FRAME_ALIGN() and
	96	SAVE_DUMMY_FRAME_TOS(). */
	97	if (fp != dummyframe->fp && fp != dummyframe->sp)
	98	continue;
	99	}
	100	/* The FP matches this dummy frame. */
8779790c	101	return dummyframe;
9c1412c1 AC	102	}
9c1412c1 AC	103
8779790c AC	104	return NULL;
	105	}
	106
	107	struct dummy_frame *
	108	cached_find_dummy_frame (struct frame_info frame, void *cache)
	109	{
	110	if ((*cache) == NULL)
bdd78e62	111	(*cache) = find_dummy_frame (get_frame_pc (frame), get_frame_base (frame));
8779790c AC	112	return (*cache);
	113	}
	114
	115	struct regcache *
	116	generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
	117	{
	118	struct dummy_frame *dummy = find_dummy_frame (pc, fp);
	119	if (dummy != NULL)
	120	return dummy->regcache;
	121	else
	122	return NULL;
9c1412c1 AC	123	}
	124
	125	char *
	126	deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
	127	{
	128	struct regcache *regcache = generic_find_dummy_frame (pc, fp);
	129	if (regcache == NULL)
	130	return NULL;
	131	return deprecated_grub_regcache_for_registers (regcache);
	132	}
	133
	134	/* Function: pc_in_call_dummy (pc, sp, fp)
	135
	136	Return true if the PC falls in a dummy frame created by gdb for an
	137	inferior call. The code below which allows DECR_PC_AFTER_BREAK is
	138	for infrun.c, which may give the function a PC without that
	139	subtracted out. */
	140
	141	int
	142	generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
5e0f933e AC	143	{
	144	return pc_in_dummy_frame (pc);
	145	}
	146
	147	/* Return non-zero if the PC falls in a dummy frame.
	148
	149	The code below which allows DECR_PC_AFTER_BREAK is for infrun.c,
	150	which may give the function a PC without that subtracted out.
	151
	152	FIXME: cagney/2002-11-23: This is silly. Surely "infrun.c" can
	153	figure out what the real PC (as in the resume address) is BEFORE
	154	calling this function (Oh, and I'm not even sure that this function
	155	is called with an decremented PC, the call to pc_in_call_dummy() in
	156	that file is conditional on !CALL_DUMMY_BREAKPOINT_OFFSET_P yet
	157	generic dummy targets set CALL_DUMMY_BREAKPOINT_OFFSET. True?). */
	158
	159	int
	160	pc_in_dummy_frame (CORE_ADDR pc)
9c1412c1 AC	161	{
	162	struct dummy_frame *dummyframe;
	163	for (dummyframe = dummy_frame_stack;
	164	dummyframe != NULL;
	165	dummyframe = dummyframe->next)
	166	{
	167	if ((pc >= dummyframe->call_lo)
	168	&& (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
	169	return 1;
	170	}
	171	return 0;
	172	}
	173
	174	/* Function: read_register_dummy
	175	Find a saved register from before GDB calls a function in the inferior */
	176
	177	CORE_ADDR
	178	deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
	179	{
	180	struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
	181
	182	if (dummy_regs)
	183	{
	184	/* NOTE: cagney/2002-08-12: Replaced a call to
	185	regcache_raw_read_as_address() with a call to
	186	regcache_cooked_read_unsigned(). The old, ...as_address
	187	function was eventually calling extract_unsigned_integer (via
	188	extract_address) to unpack the registers value. The below is
	189	doing an unsigned extract so that it is functionally
	190	equivalent. The read needs to be cooked as, otherwise, it
	191	will never correctly return the value of a register in the
	192	[NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range. */
	193	ULONGEST val;
	194	regcache_cooked_read_unsigned (dummy_regs, regno, &val);
	195	return val;
	196	}
	197	else
	198	return 0;
	199	}
	200
	201	/* Save all the registers on the dummy frame stack. Most ports save the
	202	registers on the target stack. This results in lots of unnecessary memory
	203	references, which are slow when debugging via a serial line. Instead, we
	204	save all the registers internally, and never write them to the stack. The
	205	registers get restored when the called function returns to the entry point,
	206	where a breakpoint is laying in wait. */
	207
	208	void
	209	generic_push_dummy_frame (void)
	210	{
	211	struct dummy_frame *dummy_frame;
8b36eed8	212	CORE_ADDR fp = get_frame_base (get_current_frame ());
9c1412c1 AC	213
	214	/* check to see if there are stale dummy frames,
	215	perhaps left over from when a longjump took us out of a
	216	function that was called by the debugger */
	217
	218	dummy_frame = dummy_frame_stack;
	219	while (dummy_frame)
	220	if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
	221	{
	222	dummy_frame_stack = dummy_frame->next;
	223	regcache_xfree (dummy_frame->regcache);
	224	xfree (dummy_frame);
	225	dummy_frame = dummy_frame_stack;
	226	}
	227	else
	228	dummy_frame = dummy_frame->next;
	229
	230	dummy_frame = xmalloc (sizeof (struct dummy_frame));
	231	dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
	232
	233	dummy_frame->pc = read_pc ();
	234	dummy_frame->sp = read_sp ();
	235	dummy_frame->top = 0;
	236	dummy_frame->fp = fp;
c689142b	237	dummy_frame->id = get_frame_id (get_current_frame ());
9c1412c1 AC	238	regcache_cpy (dummy_frame->regcache, current_regcache);
	239	dummy_frame->next = dummy_frame_stack;
	240	dummy_frame_stack = dummy_frame;
	241	}
	242
	243	void
	244	generic_save_dummy_frame_tos (CORE_ADDR sp)
	245	{
	246	dummy_frame_stack->top = sp;
	247	}
	248
	249	/* Record the upper/lower bounds on the address of the call dummy. */
	250
	251	void
	252	generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
	253	{
	254	dummy_frame_stack->call_lo = lo;
	255	dummy_frame_stack->call_hi = hi;
	256	}
	257
	258	/* Restore the machine state from either the saved dummy stack or a
	259	real stack frame. */
	260
	261	void
	262	generic_pop_current_frame (void (popper) (struct frame_info frame))
	263	{
	264	struct frame_info *frame = get_current_frame ();
5e0f933e AC	265	if (get_frame_type (frame) == DUMMY_FRAME)
	266	/* NOTE: cagney/2002-22-23: Does this ever occure? Surely a dummy
	267	frame will have already been poped by the "infrun.c" code. */
9c1412c1 AC	268	generic_pop_dummy_frame ();
	269	else
	270	(*popper) (frame);
	271	}
	272
	273	/* Function: pop_dummy_frame
	274	Restore the machine state from a saved dummy stack frame. */
	275
	276	void
	277	generic_pop_dummy_frame (void)
	278	{
	279	struct dummy_frame *dummy_frame = dummy_frame_stack;
	280
	281	/* FIXME: what if the first frame isn't the right one, eg..
	282	because one call-by-hand function has done a longjmp into another one? */
	283
	284	if (!dummy_frame)
	285	error ("Can't pop dummy frame!");
	286	dummy_frame_stack = dummy_frame->next;
	287	regcache_cpy (current_regcache, dummy_frame->regcache);
	288	flush_cached_frames ();
	289
	290	regcache_xfree (dummy_frame->regcache);
	291	xfree (dummy_frame);
	292	}
	293
	294	/* Function: fix_call_dummy
	295	Stub function. Generic dummy frames typically do not need to fix
	296	the frame being created */
	297
	298	void
	299	generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
	300	struct value *args, struct type type, int gcc_p)
	301	{
	302	return;
	303	}
	304
	305	/* Given a call-dummy dummy-frame, return the registers. Here the
	306	register value is taken from the local copy of the register buffer. */
	307
494cca16	308	static void
8779790c AC	309	dummy_frame_register_unwind (struct frame_info frame, void *cache,
	310	int regnum, int *optimized,
	311	enum lval_type lvalp, CORE_ADDR addrp,
	312	int realnum, void bufferp)
9c1412c1	313	{
8779790c AC	314	struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
8779790c AC	315	gdb_assert (dummy != NULL);
9c1412c1 AC	316
	317	/* Describe the register's location. Generic dummy frames always
	318	have the register value in an ``expression''. */
	319	*optimized = 0;
	320	*lvalp = not_lval;
	321	*addrp = 0;
	322	*realnum = -1;
	323
	324	/* If needed, find and return the value of the register. */
	325	if (bufferp != NULL)
	326	{
9c1412c1 AC	327	/* Return the actual value. */
	328	/* Use the regcache_cooked_read() method so that it, on the fly,
	329	constructs either a raw or pseudo register from the raw
	330	register cache. */
8779790c	331	regcache_cooked_read (dummy->regcache, regnum, bufferp);
9c1412c1 AC	332	}
	333	}
	334
494cca16 AC	335	/* Assuming that FRAME is a dummy, return the resume address for the
	336	previous frame. */
	337
	338	static CORE_ADDR
f18c5a73 AC	339	dummy_frame_pc_unwind (struct frame_info *frame,
	340	void **cache)
	341	{
	342	struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
	343	/* Oops! In a dummy-frame but can't find the stack dummy. Pretend
	344	that the frame doesn't unwind. Should this function instead
	345	return a has-no-caller indication? */
	346	if (dummy == NULL)
	347	return 0;
	348	return dummy->pc;
	349	}
	350
c689142b	351
494cca16 AC	352	/* Assuming that FRAME is a dummy, return the ID of the calling frame
	353	(the frame that the dummy has the saved state of). */
	354
	355	static void
	356	dummy_frame_id_unwind (struct frame_info *frame,
	357	void **cache,
c170fb60	358	struct frame_id *id)
c689142b AC	359	{
	360	struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
	361	/* Oops! In a dummy-frame but can't find the stack dummy. Pretend
	362	that the frame doesn't unwind. Should this function instead
	363	return a has-no-caller indication? */
	364	if (dummy == NULL)
c170fb60 AC	365	(*id) = null_frame_id;
	366	else
	367	(*id) = dummy->id;
c689142b AC	368	}
c689142b AC	369
494cca16 AC	370	static struct frame_unwind dummy_frame_unwind =
	371	{
	372	dummy_frame_pc_unwind,
	373	dummy_frame_id_unwind,
	374	dummy_frame_register_unwind
	375	};
	376
	377	const struct frame_unwind *
	378	dummy_frame_p (CORE_ADDR pc)
	379	{
	380	if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
	381	? DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)
	382	: pc_in_dummy_frame (pc))
	383	return &dummy_frame_unwind;
	384	else
	385	return NULL;
	386	}