gdb/solib-target.c - third_party/binutils-gdb - Git at Google

 /* Definitions for targets which report shared library events.

    Copyright (C) 2007-2016 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 "objfiles.h"
 #include "solist.h"
 #include "symtab.h"
 #include "symfile.h"
 #include "target.h"
 #include "vec.h"
 #include "solib-target.h"

 /* Private data for each loaded library.  */
 struct lm_info
 {
   /* The library's name.  The name is normally kept in the struct
      so_list; it is only here during XML parsing.  */
   char *name;

   /* The target can either specify segment bases or section bases, not
      both.  */

   /* The base addresses for each independently relocatable segment of
      this shared library.  */
   VEC(CORE_ADDR) *segment_bases;

   /* The base addresses for each independently allocatable,
      relocatable section of this shared library.  */
   VEC(CORE_ADDR) *section_bases;

   /* The cached offsets for each section of this shared library,
      determined from SEGMENT_BASES, or SECTION_BASES.  */
   struct section_offsets *offsets;
 };

 typedef struct lm_info *lm_info_p;
 DEF_VEC_P(lm_info_p);

 #if !defined(HAVE_LIBEXPAT)

 static VEC(lm_info_p) *
 solib_target_parse_libraries (const char *library)
 {
   static int have_warned;

   if (!have_warned)
     {
       have_warned = 1;
       warning (_("Can not parse XML library list; XML support was disabled "
 		 "at compile time"));
     }

   return NULL;
 }

 #else /* HAVE_LIBEXPAT */

 #include "xml-support.h"

 /* Handle the start of a <segment> element.  */

 static void
 library_list_start_segment (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
 			    void *user_data, VEC(gdb_xml_value_s) *attributes)
 {
   VEC(lm_info_p) **list = (VEC(lm_info_p) **) user_data;
   struct lm_info *last = VEC_last (lm_info_p, *list);
   ULONGEST *address_p
     = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
   CORE_ADDR address = (CORE_ADDR) *address_p;

   if (last->section_bases != NULL)
     gdb_xml_error (parser,
 		   _("Library list with both segments and sections"));

   VEC_safe_push (CORE_ADDR, last->segment_bases, address);
 }

 static void
 library_list_start_section (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
 			    void *user_data, VEC(gdb_xml_value_s) *attributes)
 {
   VEC(lm_info_p) **list = (VEC(lm_info_p) **) user_data;
   struct lm_info *last = VEC_last (lm_info_p, *list);
   ULONGEST *address_p
     = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
   CORE_ADDR address = (CORE_ADDR) *address_p;

   if (last->segment_bases != NULL)
     gdb_xml_error (parser,
 		   _("Library list with both segments and sections"));

   VEC_safe_push (CORE_ADDR, last->section_bases, address);
 }

 /* Handle the start of a <library> element.  */

 static void
 library_list_start_library (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
 			    void *user_data, VEC(gdb_xml_value_s) *attributes)
 {
   VEC(lm_info_p) **list = (VEC(lm_info_p) **) user_data;
   struct lm_info *item = XCNEW (struct lm_info);
   const char *name
     = (const char *) xml_find_attribute (attributes, "name")->value;

   item->name = xstrdup (name);
   VEC_safe_push (lm_info_p, *list, item);
 }

 static void
 library_list_end_library (struct gdb_xml_parser *parser,
 			  const struct gdb_xml_element *element,
 			  void *user_data, const char *body_text)
 {
   VEC(lm_info_p) **list = (VEC(lm_info_p) **) user_data;
   struct lm_info *lm_info = VEC_last (lm_info_p, *list);

   if (lm_info->segment_bases == NULL
       && lm_info->section_bases == NULL)
     gdb_xml_error (parser,
 		   _("No segment or section bases defined"));
 }


 /* Handle the start of a <library-list> element.  */

 static void
 library_list_start_list (struct gdb_xml_parser *parser,
 			 const struct gdb_xml_element *element,
 			 void *user_data, VEC(gdb_xml_value_s) *attributes)
 {
   struct gdb_xml_value *version = xml_find_attribute (attributes, "version");

   /* #FIXED attribute may be omitted, Expat returns NULL in such case.  */
   if (version != NULL)
     {
       const char *string = (const char *) version->value;

       if (strcmp (string, "1.0") != 0)
 	gdb_xml_error (parser,
 		       _("Library list has unsupported version \"%s\""),
 		       version);
     }
 }

 /* Discard the constructed library list.  */

 static void
 solib_target_free_library_list (void *p)
 {
   VEC(lm_info_p) **result = (VEC(lm_info_p) **) p;
   struct lm_info *info;
   int ix;

   for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
     {
       xfree (info->name);
       VEC_free (CORE_ADDR, info->segment_bases);
       VEC_free (CORE_ADDR, info->section_bases);
       xfree (info);
     }
   VEC_free (lm_info_p, *result);
   *result = NULL;
 }

 /* The allowed elements and attributes for an XML library list.
    The root element is a <library-list>.  */

 static const struct gdb_xml_attribute segment_attributes[] = {
   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_attribute section_attributes[] = {
   { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_element library_children[] = {
   { "segment", segment_attributes, NULL,
     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
     library_list_start_segment, NULL },
   { "section", section_attributes, NULL,
     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
     library_list_start_section, NULL },
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_attribute library_attributes[] = {
   { "name", GDB_XML_AF_NONE, NULL, NULL },
   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_element library_list_children[] = {
   { "library", library_attributes, library_children,
     GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
     library_list_start_library, library_list_end_library },
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_attribute library_list_attributes[] = {
   { "version", GDB_XML_AF_OPTIONAL, NULL, NULL },
   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 };

 static const struct gdb_xml_element library_list_elements[] = {
   { "library-list", library_list_attributes, library_list_children,
     GDB_XML_EF_NONE, library_list_start_list, NULL },
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 };

 static VEC(lm_info_p) *
 solib_target_parse_libraries (const char *library)
 {
   VEC(lm_info_p) *result = NULL;
   struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
 					  &result);

   if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
 			   library_list_elements, library, &result) == 0)
     {
       /* Parsed successfully, keep the result.  */
       discard_cleanups (back_to);
       return result;
     }

   do_cleanups (back_to);
   return NULL;
 }
 #endif

 static struct so_list *
 solib_target_current_sos (void)
 {
   struct so_list *new_solib, *start = NULL, *last = NULL;
   char *library_document;
   struct cleanup *old_chain;
   VEC(lm_info_p) *library_list;
   struct lm_info *info;
   int ix;

   /* Fetch the list of shared libraries.  */
   library_document = target_read_stralloc (&current_target,
 					   TARGET_OBJECT_LIBRARIES,
 					   NULL);
   if (library_document == NULL)
     return NULL;

   /* solib_target_parse_libraries may throw, so we use a cleanup.  */
   old_chain = make_cleanup (xfree, library_document);

   /* Parse the list.  */
   library_list = solib_target_parse_libraries (library_document);

   /* library_document string is not needed behind this point.  */
   do_cleanups (old_chain);

   if (library_list == NULL)
     return NULL;

   /* Build a struct so_list for each entry on the list.  */
   for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
     {
       new_solib = XCNEW (struct so_list);
       strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
       new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
       strncpy (new_solib->so_original_name, info->name,
 	       SO_NAME_MAX_PATH_SIZE - 1);
       new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
       new_solib->lm_info = info;

       /* We no longer need this copy of the name.  */
       xfree (info->name);
       info->name = NULL;

       /* Add it to the list.  */
       if (!start)
 	last = start = new_solib;
       else
 	{
 	  last->next = new_solib;
 	  last = new_solib;
 	}
     }

   /* Free the library list, but not its members.  */
   VEC_free (lm_info_p, library_list);

   return start;
 }

 static void
 solib_target_special_symbol_handling (void)
 {
   /* Nothing needed.  */
 }

 static void
 solib_target_solib_create_inferior_hook (int from_tty)
 {
   /* Nothing needed.  */
 }

 static void
 solib_target_clear_solib (void)
 {
   /* Nothing needed.  */
 }

 static void
 solib_target_free_so (struct so_list *so)
 {
   gdb_assert (so->lm_info->name == NULL);
   xfree (so->lm_info->offsets);
   VEC_free (CORE_ADDR, so->lm_info->segment_bases);
   xfree (so->lm_info);
 }

 static void
 solib_target_relocate_section_addresses (struct so_list *so,
 					 struct target_section *sec)
 {
   CORE_ADDR offset;

   /* Build the offset table only once per object file.  We can not do
      it any earlier, since we need to open the file first.  */
   if (so->lm_info->offsets == NULL)
     {
       int num_sections = gdb_bfd_count_sections (so->abfd);

       so->lm_info->offsets
 	= ((struct section_offsets *)
 	   xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections)));

       if (so->lm_info->section_bases)
 	{
 	  int i;
 	  asection *sect;
 	  int num_section_bases
 	    = VEC_length (CORE_ADDR, so->lm_info->section_bases);
 	  int num_alloc_sections = 0;

 	  for (i = 0, sect = so->abfd->sections;
 	       sect != NULL;
 	       i++, sect = sect->next)
 	    if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 	      num_alloc_sections++;

 	  if (num_alloc_sections != num_section_bases)
 	    warning (_("\
 Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
 		     so->so_name);
 	  else
 	    {
 	      int bases_index = 0;
 	      int found_range = 0;
 	      CORE_ADDR *section_bases;

 	      section_bases = VEC_address (CORE_ADDR,
 					   so->lm_info->section_bases);

 	      so->addr_low = ~(CORE_ADDR) 0;
 	      so->addr_high = 0;
 	      for (i = 0, sect = so->abfd->sections;
 		   sect != NULL;
 		   i++, sect = sect->next)
 		{
 		  if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
 		    continue;
 		  if (bfd_section_size (so->abfd, sect) > 0)
 		    {
 		      CORE_ADDR low, high;

 		      low = section_bases[i];
 		      high = low + bfd_section_size (so->abfd, sect) - 1;

 		      if (low < so->addr_low)
 			so->addr_low = low;
 		      if (high > so->addr_high)
 			so->addr_high = high;
 		      gdb_assert (so->addr_low <= so->addr_high);
 		      found_range = 1;
 		    }
 		  so->lm_info->offsets->offsets[i]
 		    = section_bases[bases_index];
 		  bases_index++;
 		}
 	      if (!found_range)
 		so->addr_low = so->addr_high = 0;
 	      gdb_assert (so->addr_low <= so->addr_high);
 	    }
 	}
       else if (so->lm_info->segment_bases)
 	{
 	  struct symfile_segment_data *data;

 	  data = get_symfile_segment_data (so->abfd);
 	  if (data == NULL)
 	    warning (_("\
 Could not relocate shared library \"%s\": no segments"), so->so_name);
 	  else
 	    {
 	      ULONGEST orig_delta;
 	      int i;
 	      int num_bases;
 	      CORE_ADDR *segment_bases;

 	      num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
 	      segment_bases = VEC_address (CORE_ADDR,
 					   so->lm_info->segment_bases);

 	      if (!symfile_map_offsets_to_segments (so->abfd, data,
 						    so->lm_info->offsets,
 						    num_bases, segment_bases))
 		warning (_("\
 Could not relocate shared library \"%s\": bad offsets"), so->so_name);

 	      /* Find the range of addresses to report for this library in
 		 "info sharedlibrary".  Report any consecutive segments
 		 which were relocated as a single unit.  */
 	      gdb_assert (num_bases > 0);
 	      orig_delta = segment_bases[0] - data->segment_bases[0];

 	      for (i = 1; i < data->num_segments; i++)
 		{
 		  /* If we have run out of offsets, assume all
 		     remaining segments have the same offset.  */
 		  if (i >= num_bases)
 		    continue;

 		  /* If this segment does not have the same offset, do
 		     not include it in the library's range.  */
 		  if (segment_bases[i] - data->segment_bases[i] != orig_delta)
 		    break;
 		}

 	      so->addr_low = segment_bases[0];
 	      so->addr_high = (data->segment_bases[i - 1]
 			       + data->segment_sizes[i - 1]
 			       + orig_delta);
 	      gdb_assert (so->addr_low <= so->addr_high);

 	      free_symfile_segment_data (data);
 	    }
 	}
     }

   offset = so->lm_info->offsets->offsets[gdb_bfd_section_index
 					 (sec->the_bfd_section->owner,
 					  sec->the_bfd_section)];
   sec->addr += offset;
   sec->endaddr += offset;
 }

 static int
 solib_target_open_symbol_file_object (void *from_ttyp)
 {
   /* We can't locate the main symbol file based on the target's
      knowledge; the user has to specify it.  */
   return 0;
 }

 static int
 solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
 {
   /* We don't have a range of addresses for the dynamic linker; there
      may not be one in the program's address space.  So only report
      PLT entries (which may be import stubs).  */
   return in_plt_section (pc);
 }

 struct target_so_ops solib_target_so_ops;

 /* -Wmissing-prototypes */
 extern initialize_file_ftype _initialize_solib_target;

 void
 _initialize_solib_target (void)
 {
   solib_target_so_ops.relocate_section_addresses
     = solib_target_relocate_section_addresses;
   solib_target_so_ops.free_so = solib_target_free_so;
   solib_target_so_ops.clear_solib = solib_target_clear_solib;
   solib_target_so_ops.solib_create_inferior_hook
     = solib_target_solib_create_inferior_hook;
   solib_target_so_ops.special_symbol_handling
     = solib_target_special_symbol_handling;
   solib_target_so_ops.current_sos = solib_target_current_sos;
   solib_target_so_ops.open_symbol_file_object
     = solib_target_open_symbol_file_object;
   solib_target_so_ops.in_dynsym_resolve_code
     = solib_target_in_dynsym_resolve_code;
   solib_target_so_ops.bfd_open = solib_bfd_open;

   /* Set current_target_so_ops to solib_target_so_ops if not already
      set.  */
   if (current_target_so_ops == 0)
     current_target_so_ops = &solib_target_so_ops;
 }
	/* Definitions for targets which report shared library events.

	Copyright (C) 2007-2016 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 "objfiles.h"
	#include "solist.h"
	#include "symtab.h"
	#include "symfile.h"
	#include "target.h"
	#include "vec.h"
	#include "solib-target.h"

	/* Private data for each loaded library. */
	struct lm_info
	{
	/* The library's name. The name is normally kept in the struct
	so_list; it is only here during XML parsing. */
	char *name;

	/* The target can either specify segment bases or section bases, not
	both. */

	/* The base addresses for each independently relocatable segment of
	this shared library. */
	VEC(CORE_ADDR) *segment_bases;

	/* The base addresses for each independently allocatable,
	relocatable section of this shared library. */
	VEC(CORE_ADDR) *section_bases;

	/* The cached offsets for each section of this shared library,
	determined from SEGMENT_BASES, or SECTION_BASES. */
	struct section_offsets *offsets;
	};

	typedef struct lm_info *lm_info_p;
	DEF_VEC_P(lm_info_p);

	#if !defined(HAVE_LIBEXPAT)

	static VEC(lm_info_p) *
	solib_target_parse_libraries (const char *library)
	{
	static int have_warned;

	if (!have_warned)
	{
	have_warned = 1;
	warning (_("Can not parse XML library list; XML support was disabled "
	"at compile time"));
	}

	return NULL;
	}

	#else /* HAVE_LIBEXPAT */

	#include "xml-support.h"

	/* Handle the start of a <segment> element. */

	static void
	library_list_start_segment (struct gdb_xml_parser *parser,
	const struct gdb_xml_element *element,
	void user_data, VEC(gdb_xml_value_s) attributes)
	{
	VEC(lm_info_p) list = (VEC(lm_info_p) ) user_data;
	struct lm_info last = VEC_last (lm_info_p, list);
	ULONGEST *address_p
	= (ULONGEST *) xml_find_attribute (attributes, "address")->value;
	CORE_ADDR address = (CORE_ADDR) *address_p;

	if (last->section_bases != NULL)
	gdb_xml_error (parser,
	_("Library list with both segments and sections"));

	VEC_safe_push (CORE_ADDR, last->segment_bases, address);
	}

	static void
	library_list_start_section (struct gdb_xml_parser *parser,
	const struct gdb_xml_element *element,
	void user_data, VEC(gdb_xml_value_s) attributes)
	{
	VEC(lm_info_p) list = (VEC(lm_info_p) ) user_data;
	struct lm_info last = VEC_last (lm_info_p, list);
	ULONGEST *address_p
	= (ULONGEST *) xml_find_attribute (attributes, "address")->value;
	CORE_ADDR address = (CORE_ADDR) *address_p;

	if (last->segment_bases != NULL)
	gdb_xml_error (parser,
	_("Library list with both segments and sections"));

	VEC_safe_push (CORE_ADDR, last->section_bases, address);
	}

	/* Handle the start of a <library> element. */

	static void
	library_list_start_library (struct gdb_xml_parser *parser,
	const struct gdb_xml_element *element,
	void user_data, VEC(gdb_xml_value_s) attributes)
	{
	VEC(lm_info_p) list = (VEC(lm_info_p) ) user_data;
	struct lm_info *item = XCNEW (struct lm_info);
	const char *name
	= (const char *) xml_find_attribute (attributes, "name")->value;

	item->name = xstrdup (name);
	VEC_safe_push (lm_info_p, *list, item);
	}

	static void
	library_list_end_library (struct gdb_xml_parser *parser,
	const struct gdb_xml_element *element,
	void user_data, const char body_text)
	{
	VEC(lm_info_p) list = (VEC(lm_info_p) ) user_data;
	struct lm_info lm_info = VEC_last (lm_info_p, list);

	if (lm_info->segment_bases == NULL
	&& lm_info->section_bases == NULL)
	gdb_xml_error (parser,
	_("No segment or section bases defined"));
	}


	/* Handle the start of a <library-list> element. */

	static void
	library_list_start_list (struct gdb_xml_parser *parser,
	const struct gdb_xml_element *element,
	void user_data, VEC(gdb_xml_value_s) attributes)
	{
	struct gdb_xml_value *version = xml_find_attribute (attributes, "version");

	/* #FIXED attribute may be omitted, Expat returns NULL in such case. */
	if (version != NULL)
	{
	const char string = (const char ) version->value;

	if (strcmp (string, "1.0") != 0)
	gdb_xml_error (parser,
	_("Library list has unsupported version \"%s\""),
	version);
	}
	}

	/* Discard the constructed library list. */

	static void
	solib_target_free_library_list (void *p)
	{
	VEC(lm_info_p) result = (VEC(lm_info_p) ) p;
	struct lm_info *info;
	int ix;

	for (ix = 0; VEC_iterate (lm_info_p, *result, ix, info); ix++)
	{
	xfree (info->name);
	VEC_free (CORE_ADDR, info->segment_bases);
	VEC_free (CORE_ADDR, info->section_bases);
	xfree (info);
	}
	VEC_free (lm_info_p, *result);
	*result = NULL;
	}

	/* The allowed elements and attributes for an XML library list.
	The root element is a <library-list>. */

	static const struct gdb_xml_attribute segment_attributes[] = {
	{ "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
	{ NULL, GDB_XML_AF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_attribute section_attributes[] = {
	{ "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
	{ NULL, GDB_XML_AF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_element library_children[] = {
	{ "segment", segment_attributes, NULL,
	GDB_XML_EF_REPEATABLE \| GDB_XML_EF_OPTIONAL,
	library_list_start_segment, NULL },
	{ "section", section_attributes, NULL,
	GDB_XML_EF_REPEATABLE \| GDB_XML_EF_OPTIONAL,
	library_list_start_section, NULL },
	{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_attribute library_attributes[] = {
	{ "name", GDB_XML_AF_NONE, NULL, NULL },
	{ NULL, GDB_XML_AF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_element library_list_children[] = {
	{ "library", library_attributes, library_children,
	GDB_XML_EF_REPEATABLE \| GDB_XML_EF_OPTIONAL,
	library_list_start_library, library_list_end_library },
	{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_attribute library_list_attributes[] = {
	{ "version", GDB_XML_AF_OPTIONAL, NULL, NULL },
	{ NULL, GDB_XML_AF_NONE, NULL, NULL }
	};

	static const struct gdb_xml_element library_list_elements[] = {
	{ "library-list", library_list_attributes, library_list_children,
	GDB_XML_EF_NONE, library_list_start_list, NULL },
	{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
	};

	static VEC(lm_info_p) *
	solib_target_parse_libraries (const char *library)
	{
	VEC(lm_info_p) *result = NULL;
	struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
	&result);

	if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
	library_list_elements, library, &result) == 0)
	{
	/* Parsed successfully, keep the result. */
	discard_cleanups (back_to);
	return result;
	}

	do_cleanups (back_to);
	return NULL;
	}
	#endif

	static struct so_list *
	solib_target_current_sos (void)
	{
	struct so_list new_solib, start = NULL, *last = NULL;
	char *library_document;
	struct cleanup *old_chain;
	VEC(lm_info_p) *library_list;
	struct lm_info *info;
	int ix;

	/* Fetch the list of shared libraries. */
	library_document = target_read_stralloc (&current_target,
	TARGET_OBJECT_LIBRARIES,
	NULL);
	if (library_document == NULL)
	return NULL;

	/* solib_target_parse_libraries may throw, so we use a cleanup. */
	old_chain = make_cleanup (xfree, library_document);

	/* Parse the list. */
	library_list = solib_target_parse_libraries (library_document);

	/* library_document string is not needed behind this point. */
	do_cleanups (old_chain);

	if (library_list == NULL)
	return NULL;

	/* Build a struct so_list for each entry on the list. */
	for (ix = 0; VEC_iterate (lm_info_p, library_list, ix, info); ix++)
	{
	new_solib = XCNEW (struct so_list);
	strncpy (new_solib->so_name, info->name, SO_NAME_MAX_PATH_SIZE - 1);
	new_solib->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
	strncpy (new_solib->so_original_name, info->name,
	SO_NAME_MAX_PATH_SIZE - 1);
	new_solib->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
	new_solib->lm_info = info;

	/* We no longer need this copy of the name. */
	xfree (info->name);
	info->name = NULL;

	/* Add it to the list. */
	if (!start)
	last = start = new_solib;
	else
	{
	last->next = new_solib;
	last = new_solib;
	}
	}

	/* Free the library list, but not its members. */
	VEC_free (lm_info_p, library_list);

	return start;
	}

	static void
	solib_target_special_symbol_handling (void)
	{
	/* Nothing needed. */
	}

	static void
	solib_target_solib_create_inferior_hook (int from_tty)
	{
	/* Nothing needed. */
	}

	static void
	solib_target_clear_solib (void)
	{
	/* Nothing needed. */
	}

	static void
	solib_target_free_so (struct so_list *so)
	{
	gdb_assert (so->lm_info->name == NULL);
	xfree (so->lm_info->offsets);
	VEC_free (CORE_ADDR, so->lm_info->segment_bases);
	xfree (so->lm_info);
	}

	static void
	solib_target_relocate_section_addresses (struct so_list *so,
	struct target_section *sec)
	{
	CORE_ADDR offset;

	/* Build the offset table only once per object file. We can not do
	it any earlier, since we need to open the file first. */
	if (so->lm_info->offsets == NULL)
	{
	int num_sections = gdb_bfd_count_sections (so->abfd);

	so->lm_info->offsets
	= ((struct section_offsets *)
	xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections)));

	if (so->lm_info->section_bases)
	{
	int i;
	asection *sect;
	int num_section_bases
	= VEC_length (CORE_ADDR, so->lm_info->section_bases);
	int num_alloc_sections = 0;

	for (i = 0, sect = so->abfd->sections;
	sect != NULL;
	i++, sect = sect->next)
	if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
	num_alloc_sections++;

	if (num_alloc_sections != num_section_bases)
	warning (_("\
	Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
	so->so_name);
	else
	{
	int bases_index = 0;
	int found_range = 0;
	CORE_ADDR *section_bases;

	section_bases = VEC_address (CORE_ADDR,
	so->lm_info->section_bases);

	so->addr_low = ~(CORE_ADDR) 0;
	so->addr_high = 0;
	for (i = 0, sect = so->abfd->sections;
	sect != NULL;
	i++, sect = sect->next)
	{
	if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
	continue;
	if (bfd_section_size (so->abfd, sect) > 0)
	{
	CORE_ADDR low, high;

	low = section_bases[i];
	high = low + bfd_section_size (so->abfd, sect) - 1;

	if (low < so->addr_low)
	so->addr_low = low;
	if (high > so->addr_high)
	so->addr_high = high;
	gdb_assert (so->addr_low <= so->addr_high);
	found_range = 1;
	}
	so->lm_info->offsets->offsets[i]
	= section_bases[bases_index];
	bases_index++;
	}
	if (!found_range)
	so->addr_low = so->addr_high = 0;
	gdb_assert (so->addr_low <= so->addr_high);
	}
	}
	else if (so->lm_info->segment_bases)
	{
	struct symfile_segment_data *data;

	data = get_symfile_segment_data (so->abfd);
	if (data == NULL)
	warning (_("\
	Could not relocate shared library \"%s\": no segments"), so->so_name);
	else
	{
	ULONGEST orig_delta;
	int i;
	int num_bases;
	CORE_ADDR *segment_bases;

	num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
	segment_bases = VEC_address (CORE_ADDR,
	so->lm_info->segment_bases);

	if (!symfile_map_offsets_to_segments (so->abfd, data,
	so->lm_info->offsets,
	num_bases, segment_bases))
	warning (_("\
	Could not relocate shared library \"%s\": bad offsets"), so->so_name);

	/* Find the range of addresses to report for this library in
	"info sharedlibrary". Report any consecutive segments
	which were relocated as a single unit. */
	gdb_assert (num_bases > 0);
	orig_delta = segment_bases[0] - data->segment_bases[0];

	for (i = 1; i < data->num_segments; i++)
	{
	/* If we have run out of offsets, assume all
	remaining segments have the same offset. */
	if (i >= num_bases)
	continue;

	/* If this segment does not have the same offset, do
	not include it in the library's range. */
	if (segment_bases[i] - data->segment_bases[i] != orig_delta)
	break;
	}

	so->addr_low = segment_bases[0];
	so->addr_high = (data->segment_bases[i - 1]
	+ data->segment_sizes[i - 1]
	+ orig_delta);
	gdb_assert (so->addr_low <= so->addr_high);

	free_symfile_segment_data (data);
	}
	}
	}

	offset = so->lm_info->offsets->offsets[gdb_bfd_section_index
	(sec->the_bfd_section->owner,
	sec->the_bfd_section)];
	sec->addr += offset;
	sec->endaddr += offset;
	}

	static int
	solib_target_open_symbol_file_object (void *from_ttyp)
	{
	/* We can't locate the main symbol file based on the target's
	knowledge; the user has to specify it. */
	return 0;
	}

	static int
	solib_target_in_dynsym_resolve_code (CORE_ADDR pc)
	{
	/* We don't have a range of addresses for the dynamic linker; there
	may not be one in the program's address space. So only report
	PLT entries (which may be import stubs). */
	return in_plt_section (pc);
	}

	struct target_so_ops solib_target_so_ops;

	/* -Wmissing-prototypes */
	extern initialize_file_ftype _initialize_solib_target;

	void
	_initialize_solib_target (void)
	{
	solib_target_so_ops.relocate_section_addresses
	= solib_target_relocate_section_addresses;
	solib_target_so_ops.free_so = solib_target_free_so;
	solib_target_so_ops.clear_solib = solib_target_clear_solib;
	solib_target_so_ops.solib_create_inferior_hook
	= solib_target_solib_create_inferior_hook;
	solib_target_so_ops.special_symbol_handling
	= solib_target_special_symbol_handling;
	solib_target_so_ops.current_sos = solib_target_current_sos;
	solib_target_so_ops.open_symbol_file_object
	= solib_target_open_symbol_file_object;
	solib_target_so_ops.in_dynsym_resolve_code
	= solib_target_in_dynsym_resolve_code;
	solib_target_so_ops.bfd_open = solib_bfd_open;

	/* Set current_target_so_ops to solib_target_so_ops if not already
	set. */
	if (current_target_so_ops == 0)
	current_target_so_ops = &solib_target_so_ops;
	}