if (errno) errno_reason = errno;
if (err) errno_reason = err;
_dl_map_object_deps (struct link_map *map,		     struct link_map **preloads, unsigned int npreloads,		     int trace_mode){  struct list known[1 + npreloads + 1];  struct list *runp, *tail;  unsigned int nlist, i;  /* Object name.  */  const char *name;  int errno_saved;  int errno_reason;  const char *errstring;  const char *objname;  auto inline void preload (struct link_map *map);  inline void preload (struct link_map *map)    {      known[nlist].done = 0;      known[nlist].map = map;      known[nlist].next = &known[nlist + 1];      ++nlist;      /* We use `l_reserved' as a mark bit to detect objects we have	 already put in the search list and avoid adding duplicate	 elements later in the list.  */      map->l_reserved = 1;    }  /* No loaded object so far.  */  nlist = 0;  /* First load MAP itself.  */  preload (map);  /* Add the preloaded items after MAP but before any of its dependencies.  */  for (i = 0; i < npreloads; ++i)    preload (preloads[i]);  /* Terminate the lists.  */  known[nlist - 1].next = NULL;  /* Pointer to last unique object.  */  tail = &known[nlist - 1];  /* Process each element of the search list, loading each of its     auxiliary objects and immediate dependencies.  Auxiliary objects     will be added in the list before the object itself and     dependencies will be appended to the list as we step through it.     This produces a flat, ordered list that represents a     breadth-first search of the dependency tree.     The whole process is complicated by the fact that we better     should use alloca for the temporary list elements.  But using     alloca means we cannot use recursive function calls.  */  errno_saved = errno;  errno_reason = 0;  errstring = NULL;  errno = 0;  name = NULL;  for (runp = known; runp; )    {      struct link_map *l = runp->map;      struct link_map **needed = NULL;      unsigned int nneeded = 0;      /* Unless otherwise stated, this object is handled.  */      runp->done = 1;      /* Allocate a temporary record to contain the references to the	 dependencies of this object.  */      if (l->l_searchlist.r_list == NULL && l->l_initfini == NULL	  && l != map && l->l_ldnum > 0)	needed = (struct link_map **) alloca (l->l_ldnum					      * sizeof (struct link_map *));      if (l->l_info[DT_NEEDED] || l->l_info[AUXTAG] || l->l_info[FILTERTAG])	{	  const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);	  struct openaux_args args;	  struct list *orig;	  const ElfW(Dyn) *d;	  args.strtab = strtab;	  args.map = l;	  args.trace_mode = trace_mode;	  orig = runp;	  for (d = l->l_ld; d->d_tag != DT_NULL; ++d)	    if (__builtin_expect (d->d_tag, DT_NEEDED) == DT_NEEDED)	      {		/* Map in the needed object.  */		struct link_map *dep;		/* Recognize DSTs.  */		name = expand_dst (l, strtab + d->d_un.d_val, 0);		/* Store the tag in the argument structure.  */		args.name = name;		if (_dl_catch_error (&objname, &errstring, openaux, &args))		  {		    if (errno)		      errno_reason = errno;		    else		      errno_reason = -1;		    goto out;		  }		else		  dep = args.aux;		if (! dep->l_reserved)		  {		    /* Allocate new entry.  */		    struct list *newp;		    newp = alloca (sizeof (struct list));		    /* Append DEP to the list.  */		    newp->map = dep;		    newp->done = 0;		    newp->next = NULL;		    tail->next = newp;		    tail = newp;		    ++nlist;		    /* Set the mark bit that says it's already in the list.  */		    dep->l_reserved = 1;		  }		/* Remember this dependency.  */		if (needed != NULL)		  needed[nneeded++] = dep;	      }	    else if (d->d_tag == DT_AUXILIARY || d->d_tag == DT_FILTER)	      {		struct list *newp;		/* Recognize DSTs.  */		name = expand_dst (l, strtab + d->d_un.d_val,				   d->d_tag == DT_AUXILIARY);		/* Store the tag in the argument structure.  */		args.name = name;		if (d->d_tag == DT_AUXILIARY)		  {		    /* Say that we are about to load an auxiliary library.  */		    if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))		      _dl_debug_printf ("load auxiliary object=%s"					" requested by file=%s\n", name,					l->l_name[0]					? l->l_name : _dl_argv[0]);		    /* We must be prepared that the addressed shared		       object is not available.  */		    if (_dl_catch_error (&objname, &errstring, openaux, &args))		      {			/* We are not interested in the error message.  */			assert (errstring != NULL);			if (errstring != _dl_out_of_memory)			  free ((char *) errstring);			/* Simply ignore this error and continue the work.  */			continue;		      }		  }		else		  {		    /* Say that we are about to load an auxiliary library.  */		    if (__builtin_expect (_dl_debug_mask & DL_DEBUG_LIBS, 0))		      _dl_debug_printf ("load filtered object=%s"					" requested by file=%s\n", name,					l->l_name[0]					? l->l_name : _dl_argv[0]);		    /* For filter objects the dependency must be available.  */		    if (_dl_catch_error (&objname, &errstring, openaux, &args))		      {			if (errno)			  errno_reason = errno;			else			  errno_reason = -1;			goto out;		      }		  }		/* The auxiliary object is actually available.		   Incorporate the map in all the lists.  */		/* Allocate new entry.  This always has to be done.  */		newp = alloca (sizeof (struct list));		/* We want to insert the new map before the current one,		   but we have no back links.  So we copy the contents of		   the current entry over.  Note that ORIG and NEWP now		   have switched their meanings.  */		memcpy (newp, orig, sizeof (*newp));		/* Initialize new entry.  */		orig->done = 0;		orig->map = args.aux;		/* Remember this dependency.  */		if (needed != NULL)		  needed[nneeded++] = args.aux;		/* We must handle two situations here: the map is new,		   so we must add it in all three lists.  If the map		   is already known, we have two further possibilities:		   - if the object is before the current map in the		   search list, we do nothing.  It is already found		   early		   - if the object is after the current one, we must		   move it just before the current map to make sure		   the symbols are found early enough		*/		if (args.aux->l_reserved)		  {		    /* The object is already somewhere in the list.		       Locate it first.  */		    struct list *late;		    /* This object is already in the search list we		       are building.  Don't add a duplicate pointer.		       Just added by _dl_map_object.  */		    for (late = newp; late->next; late = late->next)		      if (late->next->map == args.aux)			break;		    if (late->next)		      {			/* The object is somewhere behind the current			   position in the search path.  We have to			   move it to this earlier position.  */			orig->next = newp;			/* Now remove the later entry from the list			   and adjust the tail pointer.  */			if (tail == late->next)			  tail = late;			late->next = late->next->next;			/* We must move the object earlier in the chain.  */			if (args.aux->l_prev)			  args.aux->l_prev->l_next = args.aux->l_next;			if (args.aux->l_next)			  args.aux->l_next->l_prev = args.aux->l_prev;			args.aux->l_prev = newp->map->l_prev;			newp->map->l_prev = args.aux;			if (args.aux->l_prev != NULL)			  args.aux->l_prev->l_next = args.aux;			args.aux->l_next = newp->map;		      }		    else		      {			/* The object must be somewhere earlier in the			   list.  That's good, we only have to insert			   an entry for the duplicate list.  */			orig->next = NULL;	/* Never used.  */			/* Now we have a problem.  The element			   pointing to ORIG in the list must			   point to NEWP now.  This is the only place			   where we need this backreference and this			   situation is really not that frequent.  So			   we don't use a double-linked list but			   instead search for the preceding element.  */			late = known;			while (late->next != orig)			  late = late->next;			late->next = newp;		      }		  }		else		  {		    /* This is easy.  We just add the symbol right here.  */		    orig->next = newp;		    ++nlist;		    /* Set the mark bit that says it's already in the list.  */		    args.aux->l_reserved = 1;		    /* The only problem is that in the double linked		       list of all objects we don't have this new		       object at the correct place.  Correct this here.  */		    if (args.aux->l_prev)		      args.aux->l_prev->l_next = args.aux->l_next;		    if (args.aux->l_next)		      args.aux->l_next->l_prev = args.aux->l_prev;		    args.aux->l_prev = newp->map->l_prev;		    newp->map->l_prev = args.aux;		    if (args.aux->l_prev != NULL)		      args.aux->l_prev->l_next = args.aux;		    args.aux->l_next = newp->map;		  }		/* Move the tail pointer if necessary.  */		if (orig == tail)		  tail = newp;		/* Move on the insert point.  */		orig = newp;	      }	}      /* Terminate the list of dependencies and store the array address.  */      if (needed != NULL)	{	  needed[nneeded++] = NULL;	  l->l_initfini = malloc (nneeded * sizeof needed[0]);	  if (l->l_initfini == NULL)	    _dl_signal_error (ENOMEM, map->l_name,			      N_("cannot allocate dependency list"));	  memcpy (l->l_initfini, needed, nneeded * sizeof needed[0]);	}      /* If we have no auxiliary objects just go on to the next map.  */      if (runp->done)	do	  runp = runp->next;	while (runp != NULL && runp->done);    }out:  if (errno == 0 && errno_saved != 0)    __set_errno (errno_saved);  if (map->l_initfini != NULL && map->l_type == lt_loaded)    {      /* This object was previously loaded as a dependency and we have	 a separate l_initfini list.  We don't need it anymore.  */      assert (map->l_searchlist.r_list == NULL);      free (map->l_initfini);    }  /* Store the search list we built in the object.  It will be used for     searches in the scope of this object.  */  map->l_initfini =    (struct link_map **) malloc ((2 * nlist + 1)				 * sizeof (struct link_map *));  if (map->l_initfini == NULL)    _dl_signal_error (ENOMEM, map->l_name,		      N_("cannot allocate symbol search list"));  map->l_searchlist.r_list = &map->l_initfini[nlist + 1];  map->l_searchlist.r_nlist = nlist;  for (nlist = 0, runp = known; runp; runp = runp->next)    {      if (trace_mode && runp->map->l_faked)	/* This can happen when we trace the loading.  */	--map->l_searchlist.r_nlist;      else	map->l_searchlist.r_list[nlist++] = runp->map;      /* Now clear all the mark bits we set in the objects on the search list	 to avoid duplicates, so the next call starts fresh.  */      runp->map->l_reserved = 0;    }  /* Now determine the order in which the initialization has to happen.  */  memcpy (map->l_initfini, map->l_searchlist.r_list,	  nlist * sizeof (struct link_map *));  /* We can skip looking for the binary itself which is at the front     of the search list.  Look through the list backward so that circular     dependencies are not changing the order.  */  for (i = 1; i < nlist; ++i)    {      struct link_map *l = map->l_searchlist.r_list[i];      unsigned int j;      unsigned int k;      /* Find the place in the initfini list where the map is currently	 located.  */      for (j = 1; map->l_initfini[j] != l; ++j)	;      /* Find all object for which the current one is a dependency and	 move the found object (if necessary) in front.  */      for (k = j + 1; k < nlist; ++k)	{	  struct link_map **runp;	  runp = map->l_initfini[k]->l_initfini;	  if (runp != NULL)	    {	      while (*runp != NULL)		if (*runp == l)		  {		    struct link_map *here = map->l_initfini[k];		    /* Move it now.  */		    memmove (&map->l_initfini[j] + 1,			     &map->l_initfini[j],			     (k - j) * sizeof (struct link_map *));		    map->l_initfini[j] = here;		    break;		  }		else		  ++runp;	    }	}    }  /* Terminate the list of dependencies.  */  map->l_initfini[nlist] = NULL;  if (errno_reason)    _dl_signal_error (errno_reason == -1 ? 0 : errno_reason,		      objname, errstring);}