bfd/plugin.c - third_party/binutils-gdb - Git at Google

 /* Plugin support for BFD.
    Copyright (C) 2009-2016 Free Software Foundation, Inc.

    This file is part of BFD, the Binary File Descriptor library.

    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, write to the Free Software
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */

 #include "sysdep.h"
 #include "bfd.h"

 #if BFD_SUPPORTS_PLUGINS

 #include <assert.h>
 #ifdef HAVE_DLFCN_H
 #include <dlfcn.h>
 #elif defined (HAVE_WINDOWS_H)
 #include <windows.h>
 #else
 #error Unknown how to handle dynamic-load-libraries.
 #endif
 #include <stdarg.h>
 #include "plugin-api.h"
 #include "plugin.h"
 #include "libbfd.h"
 #include "libiberty.h"
 #include <dirent.h>

 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)

 #define RTLD_NOW 0      /* Dummy value.  */

 static void *
 dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
 {
   return LoadLibrary (file);
 }

 static void *
 dlsym (void *handle, const char *name)
 {
   return GetProcAddress (handle, name);
 }

 static int ATTRIBUTE_UNUSED
 dlclose (void *handle)
 {
   FreeLibrary (handle);
   return 0;
 }

 static const char *
 dlerror (void)
 {
   return "Unable to load DLL.";
 }

 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */

 #define bfd_plugin_close_and_cleanup                  _bfd_generic_close_and_cleanup
 #define bfd_plugin_bfd_free_cached_info               _bfd_generic_bfd_free_cached_info
 #define bfd_plugin_new_section_hook                   _bfd_generic_new_section_hook
 #define bfd_plugin_get_section_contents               _bfd_generic_get_section_contents
 #define bfd_plugin_get_section_contents_in_window     _bfd_generic_get_section_contents_in_window
 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
 #define bfd_plugin_bfd_merge_private_bfd_data         _bfd_generic_bfd_merge_private_bfd_data
 #define bfd_plugin_bfd_copy_private_header_data       _bfd_generic_bfd_copy_private_header_data
 #define bfd_plugin_bfd_set_private_flags              _bfd_generic_bfd_set_private_flags
 #define bfd_plugin_core_file_matches_executable_p     generic_core_file_matches_executable_p
 #define bfd_plugin_bfd_is_local_label_name            _bfd_nosymbols_bfd_is_local_label_name
 #define bfd_plugin_bfd_is_target_special_symbol       ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
 #define bfd_plugin_get_lineno                         _bfd_nosymbols_get_lineno
 #define bfd_plugin_find_nearest_line                  _bfd_nosymbols_find_nearest_line
 #define bfd_plugin_find_line                          _bfd_nosymbols_find_line
 #define bfd_plugin_find_inliner_info                  _bfd_nosymbols_find_inliner_info
 #define bfd_plugin_get_symbol_version_string	      _bfd_nosymbols_get_symbol_version_string
 #define bfd_plugin_bfd_make_debug_symbol              _bfd_nosymbols_bfd_make_debug_symbol
 #define bfd_plugin_read_minisymbols                   _bfd_generic_read_minisymbols
 #define bfd_plugin_minisymbol_to_symbol               _bfd_generic_minisymbol_to_symbol
 #define bfd_plugin_set_arch_mach                      bfd_default_set_arch_mach
 #define bfd_plugin_set_section_contents               _bfd_generic_set_section_contents
 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
 #define bfd_plugin_bfd_relax_section                  bfd_generic_relax_section
 #define bfd_plugin_bfd_link_hash_table_create         _bfd_generic_link_hash_table_create
 #define bfd_plugin_bfd_link_add_symbols               _bfd_generic_link_add_symbols
 #define bfd_plugin_bfd_link_just_syms                 _bfd_generic_link_just_syms
 #define bfd_plugin_bfd_final_link                     _bfd_generic_final_link
 #define bfd_plugin_bfd_link_split_section             _bfd_generic_link_split_section
 #define bfd_plugin_bfd_gc_sections                    bfd_generic_gc_sections
 #define bfd_plugin_bfd_lookup_section_flags           bfd_generic_lookup_section_flags
 #define bfd_plugin_bfd_merge_sections                 bfd_generic_merge_sections
 #define bfd_plugin_bfd_is_group_section               bfd_generic_is_group_section
 #define bfd_plugin_bfd_discard_group                  bfd_generic_discard_group
 #define bfd_plugin_section_already_linked             _bfd_generic_section_already_linked
 #define bfd_plugin_bfd_define_common_symbol           bfd_generic_define_common_symbol
 #define bfd_plugin_bfd_copy_link_hash_symbol_type     _bfd_generic_copy_link_hash_symbol_type
 #define bfd_plugin_bfd_link_check_relocs              _bfd_generic_link_check_relocs

 static enum ld_plugin_status
 message (int level ATTRIBUTE_UNUSED,
 	 const char * format, ...)
 {
   va_list args;
   va_start (args, format);
   printf ("bfd plugin: ");
   vprintf (format, args);
   putchar ('\n');
   va_end (args);
   return LDPS_OK;
 }

 /* Register a claim-file handler. */
 static ld_plugin_claim_file_handler claim_file;

 static enum ld_plugin_status
 register_claim_file (ld_plugin_claim_file_handler handler)
 {
   claim_file = handler;
   return LDPS_OK;
 }

 static enum ld_plugin_status
 add_symbols (void * handle,
 	     int nsyms,
 	     const struct ld_plugin_symbol * syms)
 {
   bfd *abfd = handle;
   struct plugin_data_struct *plugin_data =
     bfd_alloc (abfd, sizeof (plugin_data_struct));

   plugin_data->nsyms = nsyms;
   plugin_data->syms = syms;

   if (nsyms != 0)
     abfd->flags |= HAS_SYMS;

   abfd->tdata.plugin_data = plugin_data;
   return LDPS_OK;
 }

 static const char *plugin_program_name;

 void
 bfd_plugin_set_program_name (const char *program_name)
 {
   plugin_program_name = program_name;
 }

 static int
 try_claim (bfd *abfd)
 {
   int claimed = 0;
   struct ld_plugin_input_file file;
   bfd *iobfd;

   file.name = abfd->filename;

   if (abfd->my_archive && !bfd_is_thin_archive (abfd->my_archive))
     {
       iobfd = abfd->my_archive;
       file.offset = abfd->origin;
       file.filesize = arelt_size (abfd);
     }
   else
     {
       iobfd = abfd;
       file.offset = 0;
       file.filesize = 0;
     }

   if (!iobfd->iostream && !bfd_open_file (iobfd))
     return 0;

   file.fd = fileno ((FILE *) iobfd->iostream);

   if (!abfd->my_archive || bfd_is_thin_archive (abfd->my_archive))
     {
       struct stat stat_buf;
       if (fstat (file.fd, &stat_buf))
         return 0;
       file.filesize = stat_buf.st_size;
     }

   file.handle = abfd;
   off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
   claim_file (&file, &claimed);
   lseek(file.fd, cur_offset, SEEK_SET);
   if (!claimed)
     return 0;

   return 1;
 }

 static int
 try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
 {
   void *plugin_handle;
   struct ld_plugin_tv tv[4];
   int i;
   ld_plugin_onload onload;
   enum ld_plugin_status status;

   *has_plugin_p = 0;

   plugin_handle = dlopen (pname, RTLD_NOW);
   if (!plugin_handle)
     {
       (*_bfd_error_handler)("%s\n", dlerror ());
       return 0;
     }

   onload = dlsym (plugin_handle, "onload");
   if (!onload)
     goto err;

   i = 0;
   tv[i].tv_tag = LDPT_MESSAGE;
   tv[i].tv_u.tv_message = message;

   ++i;
   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
   tv[i].tv_u.tv_register_claim_file = register_claim_file;

   ++i;
   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
   tv[i].tv_u.tv_add_symbols = add_symbols;

   ++i;
   tv[i].tv_tag = LDPT_NULL;
   tv[i].tv_u.tv_val = 0;

   status = (*onload)(tv);

   if (status != LDPS_OK)
     goto err;

   *has_plugin_p = 1;

   abfd->plugin_format = bfd_plugin_no;

   if (!claim_file)
     goto err;

   if (!try_claim (abfd))
     goto err;

   abfd->plugin_format = bfd_plugin_yes;

   return 1;

  err:
   return 0;
 }

 /* There may be plugin libraries in lib/bfd-plugins.  */

 static int has_plugin = -1;

 static const bfd_target *(*ld_plugin_object_p) (bfd *);

 static const char *plugin_name;

 void
 bfd_plugin_set_plugin (const char *p)
 {
   plugin_name = p;
   has_plugin = p != NULL;
 }

 /* Return TRUE if a plugin library is used.  */

 bfd_boolean
 bfd_plugin_specified_p (void)
 {
   return has_plugin > 0;
 }

 /* Return TRUE if ABFD can be claimed by linker LTO plugin.  */

 bfd_boolean
 bfd_link_plugin_object_p (bfd *abfd)
 {
   if (ld_plugin_object_p)
     return ld_plugin_object_p (abfd) != NULL;
   return FALSE;
 }

 extern const bfd_target plugin_vec;

 /* Return TRUE if TARGET is a pointer to plugin_vec.  */

 bfd_boolean
 bfd_plugin_target_p (const bfd_target *target)
 {
   return target == &plugin_vec;
 }

 /* Register OBJECT_P to be used by bfd_plugin_object_p.  */

 void
 register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *))
 {
   ld_plugin_object_p = object_p;
 }

 static int
 load_plugin (bfd *abfd)
 {
   char *plugin_dir;
   char *p;
   DIR *d;
   struct dirent *ent;
   int found = 0;

   if (!has_plugin)
     return found;

   if (plugin_name)
     return try_load_plugin (plugin_name, abfd, &has_plugin);

   if (plugin_program_name == NULL)
     return found;

   plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
   p = make_relative_prefix (plugin_program_name,
 			    BINDIR,
 			    plugin_dir);
   free (plugin_dir);
   plugin_dir = NULL;

   d = opendir (p);
   if (!d)
     goto out;

   while ((ent = readdir (d)))
     {
       char *full_name;
       struct stat s;
       int valid_plugin;

       full_name = concat (p, "/", ent->d_name, NULL);
       if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
 	found = try_load_plugin (full_name, abfd, &valid_plugin);
       if (has_plugin <= 0)
 	has_plugin = valid_plugin;
       free (full_name);
       if (found)
 	break;
     }

  out:
   free (p);
   if (d)
     closedir (d);

   return found;
 }


 static const bfd_target *
 bfd_plugin_object_p (bfd *abfd)
 {
   if (ld_plugin_object_p)
     return ld_plugin_object_p (abfd);

   if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd))
     return NULL;

   return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL;
 }

 /* Copy any private info we understand from the input bfd
    to the output bfd.  */

 static bfd_boolean
 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
 				      bfd *obfd ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return TRUE;
 }

 /* Copy any private info we understand from the input section
    to the output section.  */

 static bfd_boolean
 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
 					  asection *isection ATTRIBUTE_UNUSED,
 					  bfd *obfd ATTRIBUTE_UNUSED,
 					  asection *osection ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return TRUE;
 }

 /* Copy any private info we understand from the input symbol
    to the output symbol.  */

 static bfd_boolean
 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
 					 asymbol *isymbol ATTRIBUTE_UNUSED,
 					 bfd *obfd ATTRIBUTE_UNUSED,
 					 asymbol *osymbol ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return TRUE;
 }

 static bfd_boolean
 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return TRUE;
 }

 static char *
 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return NULL;
 }

 static int
 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return 0;
 }

 static int
 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return 0;
 }

 static long
 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
 {
   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
   long nsyms = plugin_data->nsyms;

   BFD_ASSERT (nsyms >= 0);

   return ((nsyms + 1) * sizeof (asymbol *));
 }

 static flagword
 convert_flags (const struct ld_plugin_symbol *sym)
 {
  switch (sym->def)
    {
    case LDPK_DEF:
    case LDPK_COMMON:
    case LDPK_UNDEF:
      return BSF_GLOBAL;

    case LDPK_WEAKUNDEF:
    case LDPK_WEAKDEF:
      return BSF_GLOBAL | BSF_WEAK;

    default:
      BFD_ASSERT (0);
      return 0;
    }
 }

 static long
 bfd_plugin_canonicalize_symtab (bfd *abfd,
 				asymbol **alocation)
 {
   struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
   long nsyms = plugin_data->nsyms;
   const struct ld_plugin_symbol *syms = plugin_data->syms;
   static asection fake_section;
   static asection fake_common_section;
   int i;

   fake_section.name = ".text";
   fake_common_section.flags = SEC_IS_COMMON;

   for (i = 0; i < nsyms; i++)
     {
       asymbol *s = bfd_alloc (abfd, sizeof (asymbol));

       BFD_ASSERT (s);
       alocation[i] = s;

       s->the_bfd = abfd;
       s->name = syms[i].name;
       s->value = 0;
       s->flags = convert_flags (&syms[i]);
       switch (syms[i].def)
 	{
 	case LDPK_COMMON:
 	  s->section = &fake_common_section;
 	  break;
 	case LDPK_UNDEF:
 	case LDPK_WEAKUNDEF:
 	  s->section = bfd_und_section_ptr;
 	  break;
 	case LDPK_DEF:
 	case LDPK_WEAKDEF:
 	  s->section = &fake_section;
 	  break;
 	default:
 	  BFD_ASSERT (0);
 	}

       s->udata.p = (void *) &syms[i];
     }

   return nsyms;
 }

 static void
 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
 			 PTR afile ATTRIBUTE_UNUSED,
 			 asymbol *symbol ATTRIBUTE_UNUSED,
 			 bfd_print_symbol_type how ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
 }

 static void
 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
 			    asymbol *symbol,
 			    symbol_info *ret)
 {
   bfd_symbol_info (symbol, ret);
 }

 /* Make an empty symbol. */

 static asymbol *
 bfd_plugin_make_empty_symbol (bfd *abfd)
 {
   asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
   if (new_symbol == NULL)
     return new_symbol;
   new_symbol->the_bfd = abfd;
   return new_symbol;
 }

 static int
 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
 			   struct bfd_link_info *info ATTRIBUTE_UNUSED)
 {
   BFD_ASSERT (0);
   return 0;
 }

 const bfd_target plugin_vec =
 {
   "plugin",			/* Name.  */
   bfd_target_unknown_flavour,
   BFD_ENDIAN_LITTLE,		/* Target byte order.  */
   BFD_ENDIAN_LITTLE,		/* Target headers byte order.  */
   (HAS_RELOC | EXEC_P |		/* Object flags.  */
    HAS_LINENO | HAS_DEBUG |
    HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
   (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
    | SEC_ALLOC | SEC_LOAD | SEC_RELOC),	/* Section flags.  */
   0,				/* symbol_leading_char.  */
   '/',				/* ar_pad_char.  */
   15,				/* ar_max_namelen.  */
   255,				/* match priority.  */

   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
   bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* data */
   bfd_getl64, bfd_getl_signed_64, bfd_putl64,
   bfd_getl32, bfd_getl_signed_32, bfd_putl32,
   bfd_getl16, bfd_getl_signed_16, bfd_putl16,	/* hdrs */

   {				/* bfd_check_format.  */
     _bfd_dummy_target,
     bfd_plugin_object_p,
     bfd_generic_archive_p,
     _bfd_dummy_target
   },
   {				/* bfd_set_format.  */
     bfd_false,
     bfd_false,
     _bfd_generic_mkarchive,
     bfd_false,
   },
   {				/* bfd_write_contents.  */
     bfd_false,
     bfd_false,
     _bfd_write_archive_contents,
     bfd_false,
   },

   BFD_JUMP_TABLE_GENERIC (bfd_plugin),
   BFD_JUMP_TABLE_COPY (bfd_plugin),
   BFD_JUMP_TABLE_CORE (bfd_plugin),
 #ifdef USE_64_BIT_ARCHIVE
   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
 #else
   BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
 #endif
   BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
   BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
   BFD_JUMP_TABLE_WRITE (bfd_plugin),
   BFD_JUMP_TABLE_LINK (bfd_plugin),
   BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),

   NULL,

   NULL  			/* backend_data.  */
 };
 #endif /* BFD_SUPPORTS_PLUGIN */
	/* Plugin support for BFD.
	Copyright (C) 2009-2016 Free Software Foundation, Inc.

	This file is part of BFD, the Binary File Descriptor library.

	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, write to the Free Software
	Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
	MA 02110-1301, USA. */

	#include "sysdep.h"
	#include "bfd.h"

	#if BFD_SUPPORTS_PLUGINS

	#include <assert.h>
	#ifdef HAVE_DLFCN_H
	#include <dlfcn.h>
	#elif defined (HAVE_WINDOWS_H)
	#include <windows.h>
	#else
	#error Unknown how to handle dynamic-load-libraries.
	#endif
	#include <stdarg.h>
	#include "plugin-api.h"
	#include "plugin.h"
	#include "libbfd.h"
	#include "libiberty.h"
	#include <dirent.h>

	#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)

	#define RTLD_NOW 0 /* Dummy value. */

	static void *
	dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
	{
	return LoadLibrary (file);
	}

	static void *
	dlsym (void handle, const char name)
	{
	return GetProcAddress (handle, name);
	}

	static int ATTRIBUTE_UNUSED
	dlclose (void *handle)
	{
	FreeLibrary (handle);
	return 0;
	}

	static const char *
	dlerror (void)
	{
	return "Unable to load DLL.";
	}

	#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */

	#define bfd_plugin_close_and_cleanup _bfd_generic_close_and_cleanup
	#define bfd_plugin_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
	#define bfd_plugin_new_section_hook _bfd_generic_new_section_hook
	#define bfd_plugin_get_section_contents _bfd_generic_get_section_contents
	#define bfd_plugin_get_section_contents_in_window _bfd_generic_get_section_contents_in_window
	#define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data
	#define bfd_plugin_bfd_merge_private_bfd_data _bfd_generic_bfd_merge_private_bfd_data
	#define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data
	#define bfd_plugin_bfd_set_private_flags _bfd_generic_bfd_set_private_flags
	#define bfd_plugin_core_file_matches_executable_p generic_core_file_matches_executable_p
	#define bfd_plugin_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name
	#define bfd_plugin_bfd_is_target_special_symbol ((bfd_boolean () (bfd , asymbol *)) bfd_false)
	#define bfd_plugin_get_lineno _bfd_nosymbols_get_lineno
	#define bfd_plugin_find_nearest_line _bfd_nosymbols_find_nearest_line
	#define bfd_plugin_find_line _bfd_nosymbols_find_line
	#define bfd_plugin_find_inliner_info _bfd_nosymbols_find_inliner_info
	#define bfd_plugin_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string
	#define bfd_plugin_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
	#define bfd_plugin_read_minisymbols _bfd_generic_read_minisymbols
	#define bfd_plugin_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
	#define bfd_plugin_set_arch_mach bfd_default_set_arch_mach
	#define bfd_plugin_set_section_contents _bfd_generic_set_section_contents
	#define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
	#define bfd_plugin_bfd_relax_section bfd_generic_relax_section
	#define bfd_plugin_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
	#define bfd_plugin_bfd_link_add_symbols _bfd_generic_link_add_symbols
	#define bfd_plugin_bfd_link_just_syms _bfd_generic_link_just_syms
	#define bfd_plugin_bfd_final_link _bfd_generic_final_link
	#define bfd_plugin_bfd_link_split_section _bfd_generic_link_split_section
	#define bfd_plugin_bfd_gc_sections bfd_generic_gc_sections
	#define bfd_plugin_bfd_lookup_section_flags bfd_generic_lookup_section_flags
	#define bfd_plugin_bfd_merge_sections bfd_generic_merge_sections
	#define bfd_plugin_bfd_is_group_section bfd_generic_is_group_section
	#define bfd_plugin_bfd_discard_group bfd_generic_discard_group
	#define bfd_plugin_section_already_linked _bfd_generic_section_already_linked
	#define bfd_plugin_bfd_define_common_symbol bfd_generic_define_common_symbol
	#define bfd_plugin_bfd_copy_link_hash_symbol_type _bfd_generic_copy_link_hash_symbol_type
	#define bfd_plugin_bfd_link_check_relocs _bfd_generic_link_check_relocs

	static enum ld_plugin_status
	message (int level ATTRIBUTE_UNUSED,
	const char * format, ...)
	{
	va_list args;
	va_start (args, format);
	printf ("bfd plugin: ");
	vprintf (format, args);
	putchar ('\n');
	va_end (args);
	return LDPS_OK;
	}

	/* Register a claim-file handler. */
	static ld_plugin_claim_file_handler claim_file;

	static enum ld_plugin_status
	register_claim_file (ld_plugin_claim_file_handler handler)
	{
	claim_file = handler;
	return LDPS_OK;
	}

	static enum ld_plugin_status
	add_symbols (void * handle,
	int nsyms,
	const struct ld_plugin_symbol * syms)
	{
	bfd *abfd = handle;
	struct plugin_data_struct *plugin_data =
	bfd_alloc (abfd, sizeof (plugin_data_struct));

	plugin_data->nsyms = nsyms;
	plugin_data->syms = syms;

	if (nsyms != 0)
	abfd->flags \|= HAS_SYMS;

	abfd->tdata.plugin_data = plugin_data;
	return LDPS_OK;
	}

	static const char *plugin_program_name;

	void
	bfd_plugin_set_program_name (const char *program_name)
	{
	plugin_program_name = program_name;
	}

	static int
	try_claim (bfd *abfd)
	{
	int claimed = 0;
	struct ld_plugin_input_file file;
	bfd *iobfd;

	file.name = abfd->filename;

	if (abfd->my_archive && !bfd_is_thin_archive (abfd->my_archive))
	{
	iobfd = abfd->my_archive;
	file.offset = abfd->origin;
	file.filesize = arelt_size (abfd);
	}
	else
	{
	iobfd = abfd;
	file.offset = 0;
	file.filesize = 0;
	}

	if (!iobfd->iostream && !bfd_open_file (iobfd))
	return 0;

	file.fd = fileno ((FILE *) iobfd->iostream);

	if (!abfd->my_archive \|\| bfd_is_thin_archive (abfd->my_archive))
	{
	struct stat stat_buf;
	if (fstat (file.fd, &stat_buf))
	return 0;
	file.filesize = stat_buf.st_size;
	}

	file.handle = abfd;
	off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
	claim_file (&file, &claimed);
	lseek(file.fd, cur_offset, SEEK_SET);
	if (!claimed)
	return 0;

	return 1;
	}

	static int
	try_load_plugin (const char pname, bfd abfd, int *has_plugin_p)
	{
	void *plugin_handle;
	struct ld_plugin_tv tv[4];
	int i;
	ld_plugin_onload onload;
	enum ld_plugin_status status;

	*has_plugin_p = 0;

	plugin_handle = dlopen (pname, RTLD_NOW);
	if (!plugin_handle)
	{
	(*_bfd_error_handler)("%s\n", dlerror ());
	return 0;
	}

	onload = dlsym (plugin_handle, "onload");
	if (!onload)
	goto err;

	i = 0;
	tv[i].tv_tag = LDPT_MESSAGE;
	tv[i].tv_u.tv_message = message;

	++i;
	tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
	tv[i].tv_u.tv_register_claim_file = register_claim_file;

	++i;
	tv[i].tv_tag = LDPT_ADD_SYMBOLS;
	tv[i].tv_u.tv_add_symbols = add_symbols;

	++i;
	tv[i].tv_tag = LDPT_NULL;
	tv[i].tv_u.tv_val = 0;

	status = (*onload)(tv);

	if (status != LDPS_OK)
	goto err;

	*has_plugin_p = 1;

	abfd->plugin_format = bfd_plugin_no;

	if (!claim_file)
	goto err;

	if (!try_claim (abfd))
	goto err;

	abfd->plugin_format = bfd_plugin_yes;

	return 1;

	err:
	return 0;
	}

	/* There may be plugin libraries in lib/bfd-plugins. */

	static int has_plugin = -1;

	static const bfd_target (ld_plugin_object_p) (bfd *);

	static const char *plugin_name;

	void
	bfd_plugin_set_plugin (const char *p)
	{
	plugin_name = p;
	has_plugin = p != NULL;
	}

	/* Return TRUE if a plugin library is used. */

	bfd_boolean
	bfd_plugin_specified_p (void)
	{
	return has_plugin > 0;
	}

	/* Return TRUE if ABFD can be claimed by linker LTO plugin. */

	bfd_boolean
	bfd_link_plugin_object_p (bfd *abfd)
	{
	if (ld_plugin_object_p)
	return ld_plugin_object_p (abfd) != NULL;
	return FALSE;
	}

	extern const bfd_target plugin_vec;

	/* Return TRUE if TARGET is a pointer to plugin_vec. */

	bfd_boolean
	bfd_plugin_target_p (const bfd_target *target)
	{
	return target == &plugin_vec;
	}

	/* Register OBJECT_P to be used by bfd_plugin_object_p. */

	void
	register_ld_plugin_object_p (const bfd_target (object_p) (bfd *))
	{
	ld_plugin_object_p = object_p;
	}

	static int
	load_plugin (bfd *abfd)
	{
	char *plugin_dir;
	char *p;
	DIR *d;
	struct dirent *ent;
	int found = 0;

	if (!has_plugin)
	return found;

	if (plugin_name)
	return try_load_plugin (plugin_name, abfd, &has_plugin);

	if (plugin_program_name == NULL)
	return found;

	plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
	p = make_relative_prefix (plugin_program_name,
	BINDIR,
	plugin_dir);
	free (plugin_dir);
	plugin_dir = NULL;

	d = opendir (p);
	if (!d)
	goto out;

	while ((ent = readdir (d)))
	{
	char *full_name;
	struct stat s;
	int valid_plugin;

	full_name = concat (p, "/", ent->d_name, NULL);
	if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
	found = try_load_plugin (full_name, abfd, &valid_plugin);
	if (has_plugin <= 0)
	has_plugin = valid_plugin;
	free (full_name);
	if (found)
	break;
	}

	out:
	free (p);
	if (d)
	closedir (d);

	return found;
	}


	static const bfd_target *
	bfd_plugin_object_p (bfd *abfd)
	{
	if (ld_plugin_object_p)
	return ld_plugin_object_p (abfd);

	if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd))
	return NULL;

	return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL;
	}

	/* Copy any private info we understand from the input bfd
	to the output bfd. */

	static bfd_boolean
	bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
	bfd *obfd ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return TRUE;
	}

	/* Copy any private info we understand from the input section
	to the output section. */

	static bfd_boolean
	bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
	asection *isection ATTRIBUTE_UNUSED,
	bfd *obfd ATTRIBUTE_UNUSED,
	asection *osection ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return TRUE;
	}

	/* Copy any private info we understand from the input symbol
	to the output symbol. */

	static bfd_boolean
	bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
	asymbol *isymbol ATTRIBUTE_UNUSED,
	bfd *obfd ATTRIBUTE_UNUSED,
	asymbol *osymbol ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return TRUE;
	}

	static bfd_boolean
	bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return TRUE;
	}

	static char *
	bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return NULL;
	}

	static int
	bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return 0;
	}

	static int
	bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return 0;
	}

	static long
	bfd_plugin_get_symtab_upper_bound (bfd *abfd)
	{
	struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
	long nsyms = plugin_data->nsyms;

	BFD_ASSERT (nsyms >= 0);

	return ((nsyms + 1) * sizeof (asymbol *));
	}

	static flagword
	convert_flags (const struct ld_plugin_symbol *sym)
	{
	switch (sym->def)
	{
	case LDPK_DEF:
	case LDPK_COMMON:
	case LDPK_UNDEF:
	return BSF_GLOBAL;

	case LDPK_WEAKUNDEF:
	case LDPK_WEAKDEF:
	return BSF_GLOBAL \| BSF_WEAK;

	default:
	BFD_ASSERT (0);
	return 0;
	}
	}

	static long
	bfd_plugin_canonicalize_symtab (bfd *abfd,
	asymbol **alocation)
	{
	struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
	long nsyms = plugin_data->nsyms;
	const struct ld_plugin_symbol *syms = plugin_data->syms;
	static asection fake_section;
	static asection fake_common_section;
	int i;

	fake_section.name = ".text";
	fake_common_section.flags = SEC_IS_COMMON;

	for (i = 0; i < nsyms; i++)
	{
	asymbol *s = bfd_alloc (abfd, sizeof (asymbol));

	BFD_ASSERT (s);
	alocation[i] = s;

	s->the_bfd = abfd;
	s->name = syms[i].name;
	s->value = 0;
	s->flags = convert_flags (&syms[i]);
	switch (syms[i].def)
	{
	case LDPK_COMMON:
	s->section = &fake_common_section;
	break;
	case LDPK_UNDEF:
	case LDPK_WEAKUNDEF:
	s->section = bfd_und_section_ptr;
	break;
	case LDPK_DEF:
	case LDPK_WEAKDEF:
	s->section = &fake_section;
	break;
	default:
	BFD_ASSERT (0);
	}

	s->udata.p = (void *) &syms[i];
	}

	return nsyms;
	}

	static void
	bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
	PTR afile ATTRIBUTE_UNUSED,
	asymbol *symbol ATTRIBUTE_UNUSED,
	bfd_print_symbol_type how ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	}

	static void
	bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
	asymbol *symbol,
	symbol_info *ret)
	{
	bfd_symbol_info (symbol, ret);
	}

	/* Make an empty symbol. */

	static asymbol *
	bfd_plugin_make_empty_symbol (bfd *abfd)
	{
	asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
	if (new_symbol == NULL)
	return new_symbol;
	new_symbol->the_bfd = abfd;
	return new_symbol;
	}

	static int
	bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
	struct bfd_link_info *info ATTRIBUTE_UNUSED)
	{
	BFD_ASSERT (0);
	return 0;
	}

	const bfd_target plugin_vec =
	{
	"plugin", /* Name. */
	bfd_target_unknown_flavour,
	BFD_ENDIAN_LITTLE, /* Target byte order. */
	BFD_ENDIAN_LITTLE, /* Target headers byte order. */
	(HAS_RELOC \| EXEC_P \| /* Object flags. */
	HAS_LINENO \| HAS_DEBUG \|
	HAS_SYMS \| HAS_LOCALS \| DYNAMIC \| WP_TEXT \| D_PAGED),
	(SEC_CODE \| SEC_DATA \| SEC_ROM \| SEC_HAS_CONTENTS
	\| SEC_ALLOC \| SEC_LOAD \| SEC_RELOC), /* Section flags. */
	0, /* symbol_leading_char. */
	'/', /* ar_pad_char. */
	15, /* ar_max_namelen. */
	255, /* match priority. */

	bfd_getl64, bfd_getl_signed_64, bfd_putl64,
	bfd_getl32, bfd_getl_signed_32, bfd_putl32,
	bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
	bfd_getl64, bfd_getl_signed_64, bfd_putl64,
	bfd_getl32, bfd_getl_signed_32, bfd_putl32,
	bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */

	{ /* bfd_check_format. */
	_bfd_dummy_target,
	bfd_plugin_object_p,
	bfd_generic_archive_p,
	_bfd_dummy_target
	},
	{ /* bfd_set_format. */
	bfd_false,
	bfd_false,
	_bfd_generic_mkarchive,
	bfd_false,
	},
	{ /* bfd_write_contents. */
	bfd_false,
	bfd_false,
	_bfd_write_archive_contents,
	bfd_false,
	},

	BFD_JUMP_TABLE_GENERIC (bfd_plugin),
	BFD_JUMP_TABLE_COPY (bfd_plugin),
	BFD_JUMP_TABLE_CORE (bfd_plugin),
	#ifdef USE_64_BIT_ARCHIVE
	BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
	#else
	BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
	#endif
	BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
	BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
	BFD_JUMP_TABLE_WRITE (bfd_plugin),
	BFD_JUMP_TABLE_LINK (bfd_plugin),
	BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),

	NULL,

	NULL /* backend_data. */
	};
	#endif /* BFD_SUPPORTS_PLUGIN */