gdb/inline-frame.c - third_party/gdb - Git at Google

 /* Inline frame unwinder for GDB.

    Copyright (C) 2008-2016 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/>.  */

 #include "defs.h"
 #include "inline-frame.h"
 #include "addrmap.h"
 #include "block.h"
 #include "frame-unwind.h"
 #include "inferior.h"
 #include "regcache.h"
 #include "symtab.h"
 #include "vec.h"
 #include "frame.h"

 /* We need to save a few variables for every thread stopped at the
    virtual call site of an inlined function.  If there was always a
    "struct thread_info", we could hang it off that; in the mean time,
    keep our own list.  */
 struct inline_state
 {
   /* The thread this data relates to.  It should be a currently
      stopped thread; we assume thread IDs never change while the
      thread is stopped.  */
   ptid_t ptid;

   /* The number of inlined functions we are skipping.  Each of these
      functions can be stepped in to.  */
   int skipped_frames;

   /* Only valid if SKIPPED_FRAMES is non-zero.  This is the PC used
      when calculating SKIPPED_FRAMES; used to check whether we have
      moved to a new location by user request.  If so, we invalidate
      any skipped frames.  */
   CORE_ADDR saved_pc;

   /* Only valid if SKIPPED_FRAMES is non-zero.  This is the symbol
      of the outermost skipped inline function.  It's used to find the
      call site of the current frame.  */
   struct symbol *skipped_symbol;
 };

 typedef struct inline_state inline_state_s;
 DEF_VEC_O(inline_state_s);

 static VEC(inline_state_s) *inline_states;

 /* Locate saved inlined frame state for PTID, if it exists
    and is valid.  */

 static struct inline_state *
 find_inline_frame_state (ptid_t ptid)
 {
   struct inline_state *state;
   int ix;

   for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
     {
       if (ptid_equal (state->ptid, ptid))
 	{
 	  struct regcache *regcache = get_thread_regcache (ptid);
 	  CORE_ADDR current_pc = regcache_read_pc (regcache);

 	  if (current_pc != state->saved_pc)
 	    {
 	      /* PC has changed - this context is invalid.  Use the
 		 default behavior.  */
 	      VEC_unordered_remove (inline_state_s, inline_states, ix);
 	      return NULL;
 	    }
 	  else
 	    return state;
 	}
     }

   return NULL;
 }

 /* Allocate saved inlined frame state for PTID.  */

 static struct inline_state *
 allocate_inline_frame_state (ptid_t ptid)
 {
   struct inline_state *state;

   state = VEC_safe_push (inline_state_s, inline_states, NULL);
   memset (state, 0, sizeof (*state));
   state->ptid = ptid;

   return state;
 }

 /* Forget about any hidden inlined functions in PTID, which is new or
    about to be resumed.  PTID may be minus_one_ptid (all processes)
    or a PID (all threads in this process).  */

 void
 clear_inline_frame_state (ptid_t ptid)
 {
   struct inline_state *state;
   int ix;

   if (ptid_equal (ptid, minus_one_ptid))
     {
       VEC_free (inline_state_s, inline_states);
       return;
     }

   if (ptid_is_pid (ptid))
     {
       VEC (inline_state_s) *new_states = NULL;
       int pid = ptid_get_pid (ptid);

       for (ix = 0;
 	   VEC_iterate (inline_state_s, inline_states, ix, state);
 	   ix++)
 	if (pid != ptid_get_pid (state->ptid))
 	  VEC_safe_push (inline_state_s, new_states, state);
       VEC_free (inline_state_s, inline_states);
       inline_states = new_states;
       return;
     }

   for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
     if (ptid_equal (state->ptid, ptid))
       {
 	VEC_unordered_remove (inline_state_s, inline_states, ix);
 	return;
       }
 }

 static void
 inline_frame_this_id (struct frame_info *this_frame,
 		      void **this_cache,
 		      struct frame_id *this_id)
 {
   struct symbol *func;

   /* In order to have a stable frame ID for a given inline function,
      we must get the stack / special addresses from the underlying
      real frame's this_id method.  So we must call
      get_prev_frame_always.  Because we are inlined into some
      function, there must be previous frames, so this is safe - as
      long as we're careful not to create any cycles.  */
   *this_id = get_frame_id (get_prev_frame_always (this_frame));

   /* We need a valid frame ID, so we need to be based on a valid
      frame.  FSF submission NOTE: this would be a good assertion to
      apply to all frames, all the time.  That would fix the ambiguity
      of null_frame_id (between "no/any frame" and "the outermost
      frame").  This will take work.  */
   gdb_assert (frame_id_p (*this_id));

   /* For now, require we don't match outer_frame_id either (see
      comment above).  */
   gdb_assert (!frame_id_eq (*this_id, outer_frame_id));

   /* Future work NOTE: Alexandre Oliva applied a patch to GCC 4.3
      which generates DW_AT_entry_pc for inlined functions when
      possible.  If this attribute is available, we should use it
      in the frame ID (and eventually, to set breakpoints).  */
   func = get_frame_function (this_frame);
   gdb_assert (func != NULL);
   (*this_id).code_addr = BLOCK_START (SYMBOL_BLOCK_VALUE (func));
   (*this_id).artificial_depth++;
 }

 static struct value *
 inline_frame_prev_register (struct frame_info *this_frame, void **this_cache,
 			    int regnum)
 {
   /* Use get_frame_register_value instead of
      frame_unwind_got_register, to avoid requiring this frame's ID.
      This frame's ID depends on the previous frame's ID (unusual), and
      the previous frame's ID depends on this frame's unwound
      registers.  If unwinding registers from this frame called
      get_frame_id, there would be a loop.

      Do not copy this code into any other unwinder!  Inlined functions
      are special; other unwinders must not have a dependency on the
      previous frame's ID, and therefore can and should use
      frame_unwind_got_register instead.  */
   return get_frame_register_value (this_frame, regnum);
 }

 /* Check whether we are at an inlining site that does not already
    have an associated frame.  */

 static int
 inline_frame_sniffer (const struct frame_unwind *self,
 		      struct frame_info *this_frame,
 		      void **this_cache)
 {
   CORE_ADDR this_pc;
   const struct block *frame_block, *cur_block;
   int depth;
   struct frame_info *next_frame;
   struct inline_state *state = find_inline_frame_state (inferior_ptid);

   this_pc = get_frame_address_in_block (this_frame);
   frame_block = block_for_pc (this_pc);
   if (frame_block == NULL)
     return 0;

   /* Calculate DEPTH, the number of inlined functions at this
      location.  */
   depth = 0;
   cur_block = frame_block;
   while (BLOCK_SUPERBLOCK (cur_block))
     {
       if (block_inlined_p (cur_block))
 	depth++;
       else if (BLOCK_FUNCTION (cur_block) != NULL)
 	break;

       cur_block = BLOCK_SUPERBLOCK (cur_block);
     }

   /* Check how many inlined functions already have frames.  */
   for (next_frame = get_next_frame (this_frame);
        next_frame && get_frame_type (next_frame) == INLINE_FRAME;
        next_frame = get_next_frame (next_frame))
     {
       gdb_assert (depth > 0);
       depth--;
     }

   /* If this is the topmost frame, or all frames above us are inlined,
      then check whether we were requested to skip some frames (so they
      can be stepped into later).  */
   if (state != NULL && state->skipped_frames > 0 && next_frame == NULL)
     {
       gdb_assert (depth >= state->skipped_frames);
       depth -= state->skipped_frames;
     }

   /* If all the inlined functions here already have frames, then pass
      to the normal unwinder for this PC.  */
   if (depth == 0)
     return 0;

   /* If the next frame is an inlined function, but not the outermost, then
      we are the next outer.  If it is not an inlined function, then we
      are the innermost inlined function of a different real frame.  */
   return 1;
 }

 const struct frame_unwind inline_frame_unwind = {
   INLINE_FRAME,
   default_frame_unwind_stop_reason,
   inline_frame_this_id,
   inline_frame_prev_register,
   NULL,
   inline_frame_sniffer
 };

 /* Return non-zero if BLOCK, an inlined function block containing PC,
    has a group of contiguous instructions starting at PC (but not
    before it).  */

 static int
 block_starting_point_at (CORE_ADDR pc, const struct block *block)
 {
   const struct blockvector *bv;
   struct block *new_block;

   bv = blockvector_for_pc (pc, NULL);
   if (BLOCKVECTOR_MAP (bv) == NULL)
     return 0;

   new_block = (struct block *) addrmap_find (BLOCKVECTOR_MAP (bv), pc - 1);
   if (new_block == NULL)
     return 1;

   if (new_block == block || contained_in (new_block, block))
     return 0;

   /* The immediately preceding address belongs to a different block,
      which is not a child of this one.  Treat this as an entrance into
      BLOCK.  */
   return 1;
 }

 /* Skip all inlined functions whose call sites are at the current PC.
    Frames for the hidden functions will not appear in the backtrace until the
    user steps into them.  */

 void
 skip_inline_frames (ptid_t ptid)
 {
   CORE_ADDR this_pc;
   const struct block *frame_block, *cur_block;
   struct symbol *last_sym = NULL;
   int skip_count = 0;
   struct inline_state *state;

   /* This function is called right after reinitializing the frame
      cache.  We try not to do more unwinding than absolutely
      necessary, for performance.  */
   this_pc = get_frame_pc (get_current_frame ());
   frame_block = block_for_pc (this_pc);

   if (frame_block != NULL)
     {
       cur_block = frame_block;
       while (BLOCK_SUPERBLOCK (cur_block))
 	{
 	  if (block_inlined_p (cur_block))
 	    {
 	      /* See comments in inline_frame_this_id about this use
 		 of BLOCK_START.  */
 	      if (BLOCK_START (cur_block) == this_pc
 		  || block_starting_point_at (this_pc, cur_block))
 		{
 		  skip_count++;
 		  last_sym = BLOCK_FUNCTION (cur_block);
 		}
 	      else
 		break;
 	    }
 	  else if (BLOCK_FUNCTION (cur_block) != NULL)
 	    break;

 	  cur_block = BLOCK_SUPERBLOCK (cur_block);
 	}
     }

   gdb_assert (find_inline_frame_state (ptid) == NULL);
   state = allocate_inline_frame_state (ptid);
   state->skipped_frames = skip_count;
   state->saved_pc = this_pc;
   state->skipped_symbol = last_sym;

   if (skip_count != 0)
     reinit_frame_cache ();
 }

 /* Step into an inlined function by unhiding it.  */

 void
 step_into_inline_frame (ptid_t ptid)
 {
   struct inline_state *state = find_inline_frame_state (ptid);

   gdb_assert (state != NULL && state->skipped_frames > 0);
   state->skipped_frames--;
   reinit_frame_cache ();
 }

 /* Return the number of hidden functions inlined into the current
    frame.  */

 int
 inline_skipped_frames (ptid_t ptid)
 {
   struct inline_state *state = find_inline_frame_state (ptid);

   if (state == NULL)
     return 0;
   else
     return state->skipped_frames;
 }

 /* If one or more inlined functions are hidden, return the symbol for
    the function inlined into the current frame.  */

 struct symbol *
 inline_skipped_symbol (ptid_t ptid)
 {
   struct inline_state *state = find_inline_frame_state (ptid);

   gdb_assert (state != NULL);
   return state->skipped_symbol;
 }

 /* Return the number of functions inlined into THIS_FRAME.  Some of
    the callees may not have associated frames (see
    skip_inline_frames).  */

 int
 frame_inlined_callees (struct frame_info *this_frame)
 {
   struct frame_info *next_frame;
   int inline_count = 0;

   /* First count how many inlined functions at this PC have frames
      above FRAME (are inlined into FRAME).  */
   for (next_frame = get_next_frame (this_frame);
        next_frame && get_frame_type (next_frame) == INLINE_FRAME;
        next_frame = get_next_frame (next_frame))
     inline_count++;

   /* Simulate some most-inner inlined frames which were suppressed, so
      they can be stepped into later.  If we are unwinding already
      outer frames from some non-inlined frame this does not apply.  */
   if (next_frame == NULL)
     inline_count += inline_skipped_frames (inferior_ptid);

   return inline_count;
 }
	/* Inline frame unwinder for GDB.

	Copyright (C) 2008-2016 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/>. */

	#include "defs.h"
	#include "inline-frame.h"
	#include "addrmap.h"
	#include "block.h"
	#include "frame-unwind.h"
	#include "inferior.h"
	#include "regcache.h"
	#include "symtab.h"
	#include "vec.h"
	#include "frame.h"

	/* We need to save a few variables for every thread stopped at the
	virtual call site of an inlined function. If there was always a
	"struct thread_info", we could hang it off that; in the mean time,
	keep our own list. */
	struct inline_state
	{
	/* The thread this data relates to. It should be a currently
	stopped thread; we assume thread IDs never change while the
	thread is stopped. */
	ptid_t ptid;

	/* The number of inlined functions we are skipping. Each of these
	functions can be stepped in to. */
	int skipped_frames;

	/* Only valid if SKIPPED_FRAMES is non-zero. This is the PC used
	when calculating SKIPPED_FRAMES; used to check whether we have
	moved to a new location by user request. If so, we invalidate
	any skipped frames. */
	CORE_ADDR saved_pc;

	/* Only valid if SKIPPED_FRAMES is non-zero. This is the symbol
	of the outermost skipped inline function. It's used to find the
	call site of the current frame. */
	struct symbol *skipped_symbol;
	};

	typedef struct inline_state inline_state_s;
	DEF_VEC_O(inline_state_s);

	static VEC(inline_state_s) *inline_states;

	/* Locate saved inlined frame state for PTID, if it exists
	and is valid. */

	static struct inline_state *
	find_inline_frame_state (ptid_t ptid)
	{
	struct inline_state *state;
	int ix;

	for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
	{
	if (ptid_equal (state->ptid, ptid))
	{
	struct regcache *regcache = get_thread_regcache (ptid);
	CORE_ADDR current_pc = regcache_read_pc (regcache);

	if (current_pc != state->saved_pc)
	{
	/* PC has changed - this context is invalid. Use the
	default behavior. */
	VEC_unordered_remove (inline_state_s, inline_states, ix);
	return NULL;
	}
	else
	return state;
	}
	}

	return NULL;
	}

	/* Allocate saved inlined frame state for PTID. */

	static struct inline_state *
	allocate_inline_frame_state (ptid_t ptid)
	{
	struct inline_state *state;

	state = VEC_safe_push (inline_state_s, inline_states, NULL);
	memset (state, 0, sizeof (*state));
	state->ptid = ptid;

	return state;
	}

	/* Forget about any hidden inlined functions in PTID, which is new or
	about to be resumed. PTID may be minus_one_ptid (all processes)
	or a PID (all threads in this process). */

	void
	clear_inline_frame_state (ptid_t ptid)
	{
	struct inline_state *state;
	int ix;

	if (ptid_equal (ptid, minus_one_ptid))
	{
	VEC_free (inline_state_s, inline_states);
	return;
	}

	if (ptid_is_pid (ptid))
	{
	VEC (inline_state_s) *new_states = NULL;
	int pid = ptid_get_pid (ptid);

	for (ix = 0;
	VEC_iterate (inline_state_s, inline_states, ix, state);
	ix++)
	if (pid != ptid_get_pid (state->ptid))
	VEC_safe_push (inline_state_s, new_states, state);
	VEC_free (inline_state_s, inline_states);
	inline_states = new_states;
	return;
	}

	for (ix = 0; VEC_iterate (inline_state_s, inline_states, ix, state); ix++)
	if (ptid_equal (state->ptid, ptid))
	{
	VEC_unordered_remove (inline_state_s, inline_states, ix);
	return;
	}
	}

	static void
	inline_frame_this_id (struct frame_info *this_frame,
	void **this_cache,
	struct frame_id *this_id)
	{
	struct symbol *func;

	/* In order to have a stable frame ID for a given inline function,
	we must get the stack / special addresses from the underlying
	real frame's this_id method. So we must call
	get_prev_frame_always. Because we are inlined into some
	function, there must be previous frames, so this is safe - as
	long as we're careful not to create any cycles. */
	*this_id = get_frame_id (get_prev_frame_always (this_frame));

	/* We need a valid frame ID, so we need to be based on a valid
	frame. FSF submission NOTE: this would be a good assertion to
	apply to all frames, all the time. That would fix the ambiguity
	of null_frame_id (between "no/any frame" and "the outermost
	frame"). This will take work. */
	gdb_assert (frame_id_p (*this_id));

	/* For now, require we don't match outer_frame_id either (see
	comment above). */
	gdb_assert (!frame_id_eq (*this_id, outer_frame_id));

	/* Future work NOTE: Alexandre Oliva applied a patch to GCC 4.3
	which generates DW_AT_entry_pc for inlined functions when
	possible. If this attribute is available, we should use it
	in the frame ID (and eventually, to set breakpoints). */
	func = get_frame_function (this_frame);
	gdb_assert (func != NULL);
	(*this_id).code_addr = BLOCK_START (SYMBOL_BLOCK_VALUE (func));
	(*this_id).artificial_depth++;
	}

	static struct value *
	inline_frame_prev_register (struct frame_info this_frame, void *this_cache,
	int regnum)
	{
	/* Use get_frame_register_value instead of
	frame_unwind_got_register, to avoid requiring this frame's ID.
	This frame's ID depends on the previous frame's ID (unusual), and
	the previous frame's ID depends on this frame's unwound
	registers. If unwinding registers from this frame called
	get_frame_id, there would be a loop.

	Do not copy this code into any other unwinder! Inlined functions
	are special; other unwinders must not have a dependency on the
	previous frame's ID, and therefore can and should use
	frame_unwind_got_register instead. */
	return get_frame_register_value (this_frame, regnum);
	}

	/* Check whether we are at an inlining site that does not already
	have an associated frame. */

	static int
	inline_frame_sniffer (const struct frame_unwind *self,
	struct frame_info *this_frame,
	void **this_cache)
	{
	CORE_ADDR this_pc;
	const struct block frame_block, cur_block;
	int depth;
	struct frame_info *next_frame;
	struct inline_state *state = find_inline_frame_state (inferior_ptid);

	this_pc = get_frame_address_in_block (this_frame);
	frame_block = block_for_pc (this_pc);
	if (frame_block == NULL)
	return 0;

	/* Calculate DEPTH, the number of inlined functions at this
	location. */
	depth = 0;
	cur_block = frame_block;
	while (BLOCK_SUPERBLOCK (cur_block))
	{
	if (block_inlined_p (cur_block))
	depth++;
	else if (BLOCK_FUNCTION (cur_block) != NULL)
	break;

	cur_block = BLOCK_SUPERBLOCK (cur_block);
	}

	/* Check how many inlined functions already have frames. */
	for (next_frame = get_next_frame (this_frame);
	next_frame && get_frame_type (next_frame) == INLINE_FRAME;
	next_frame = get_next_frame (next_frame))
	{
	gdb_assert (depth > 0);
	depth--;
	}

	/* If this is the topmost frame, or all frames above us are inlined,
	then check whether we were requested to skip some frames (so they
	can be stepped into later). */
	if (state != NULL && state->skipped_frames > 0 && next_frame == NULL)
	{
	gdb_assert (depth >= state->skipped_frames);
	depth -= state->skipped_frames;
	}

	/* If all the inlined functions here already have frames, then pass
	to the normal unwinder for this PC. */
	if (depth == 0)
	return 0;

	/* If the next frame is an inlined function, but not the outermost, then
	we are the next outer. If it is not an inlined function, then we
	are the innermost inlined function of a different real frame. */
	return 1;
	}

	const struct frame_unwind inline_frame_unwind = {
	INLINE_FRAME,
	default_frame_unwind_stop_reason,
	inline_frame_this_id,
	inline_frame_prev_register,
	NULL,
	inline_frame_sniffer
	};

	/* Return non-zero if BLOCK, an inlined function block containing PC,
	has a group of contiguous instructions starting at PC (but not
	before it). */

	static int
	block_starting_point_at (CORE_ADDR pc, const struct block *block)
	{
	const struct blockvector *bv;
	struct block *new_block;

	bv = blockvector_for_pc (pc, NULL);
	if (BLOCKVECTOR_MAP (bv) == NULL)
	return 0;

	new_block = (struct block *) addrmap_find (BLOCKVECTOR_MAP (bv), pc - 1);
	if (new_block == NULL)
	return 1;

	if (new_block == block \|\| contained_in (new_block, block))
	return 0;

	/* The immediately preceding address belongs to a different block,
	which is not a child of this one. Treat this as an entrance into
	BLOCK. */
	return 1;
	}

	/* Skip all inlined functions whose call sites are at the current PC.
	Frames for the hidden functions will not appear in the backtrace until the
	user steps into them. */

	void
	skip_inline_frames (ptid_t ptid)
	{
	CORE_ADDR this_pc;
	const struct block frame_block, cur_block;
	struct symbol *last_sym = NULL;
	int skip_count = 0;
	struct inline_state *state;

	/* This function is called right after reinitializing the frame
	cache. We try not to do more unwinding than absolutely
	necessary, for performance. */
	this_pc = get_frame_pc (get_current_frame ());
	frame_block = block_for_pc (this_pc);

	if (frame_block != NULL)
	{
	cur_block = frame_block;
	while (BLOCK_SUPERBLOCK (cur_block))
	{
	if (block_inlined_p (cur_block))
	{
	/* See comments in inline_frame_this_id about this use
	of BLOCK_START. */
	if (BLOCK_START (cur_block) == this_pc
	\|\| block_starting_point_at (this_pc, cur_block))
	{
	skip_count++;
	last_sym = BLOCK_FUNCTION (cur_block);
	}
	else
	break;
	}
	else if (BLOCK_FUNCTION (cur_block) != NULL)
	break;

	cur_block = BLOCK_SUPERBLOCK (cur_block);
	}
	}

	gdb_assert (find_inline_frame_state (ptid) == NULL);
	state = allocate_inline_frame_state (ptid);
	state->skipped_frames = skip_count;
	state->saved_pc = this_pc;
	state->skipped_symbol = last_sym;

	if (skip_count != 0)
	reinit_frame_cache ();
	}

	/* Step into an inlined function by unhiding it. */

	void
	step_into_inline_frame (ptid_t ptid)
	{
	struct inline_state *state = find_inline_frame_state (ptid);

	gdb_assert (state != NULL && state->skipped_frames > 0);
	state->skipped_frames--;
	reinit_frame_cache ();
	}

	/* Return the number of hidden functions inlined into the current
	frame. */

	int
	inline_skipped_frames (ptid_t ptid)
	{
	struct inline_state *state = find_inline_frame_state (ptid);

	if (state == NULL)
	return 0;
	else
	return state->skipped_frames;
	}

	/* If one or more inlined functions are hidden, return the symbol for
	the function inlined into the current frame. */

	struct symbol *
	inline_skipped_symbol (ptid_t ptid)
	{
	struct inline_state *state = find_inline_frame_state (ptid);

	gdb_assert (state != NULL);
	return state->skipped_symbol;
	}

	/* Return the number of functions inlined into THIS_FRAME. Some of
	the callees may not have associated frames (see
	skip_inline_frames). */

	int
	frame_inlined_callees (struct frame_info *this_frame)
	{
	struct frame_info *next_frame;
	int inline_count = 0;

	/* First count how many inlined functions at this PC have frames
	above FRAME (are inlined into FRAME). */
	for (next_frame = get_next_frame (this_frame);
	next_frame && get_frame_type (next_frame) == INLINE_FRAME;
	next_frame = get_next_frame (next_frame))
	inline_count++;

	/* Simulate some most-inner inlined frames which were suppressed, so
	they can be stepped into later. If we are unwinding already
	outer frames from some non-inlined frame this does not apply. */
	if (next_frame == NULL)
	inline_count += inline_skipped_frames (inferior_ptid);

	return inline_count;
	}