Esempio n. 1
0
/* Return TRUE if a defined symbol might be reachable from outside the
   universe of claimed objects.  */
static inline bfd_boolean
is_visible_from_outside (struct ld_plugin_symbol *lsym,
                         struct bfd_link_hash_entry *blhe)
{
    struct bfd_sym_chain *sym;

    if (bfd_link_relocatable (&link_info))
        return TRUE;
    if (link_info.export_dynamic || bfd_link_dll (&link_info))
    {
        /* Check if symbol is hidden by version script.  */
        if (bfd_hide_sym_by_version (link_info.version_info,
                                     blhe->root.string))
            return FALSE;
        /* Only ELF symbols really have visibility.  */
        if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
        {
            struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe;
            int vis = ELF_ST_VISIBILITY (el->other);
            return vis == STV_DEFAULT || vis == STV_PROTECTED;
        }
        /* On non-ELF targets, we can safely make inferences by considering
        what visibility the plugin would have liked to apply when it first
         sent us the symbol.  During ELF symbol processing, visibility only
         ever becomes more restrictive, not less, when symbols are merged,
         so this is a conservative estimate; it may give false positives,
         declaring something visible from outside when it in fact would
         not have been, but this will only lead to missed optimisation
         opportunities during LTRANS at worst; it will not give false
         negatives, which can lead to the disastrous conclusion that the
         related symbol is IRONLY.  (See GCC PR46319 for an example.)  */
        return (lsym->visibility == LDPV_DEFAULT
                || lsym->visibility == LDPV_PROTECTED);
    }

    for (sym = &entry_symbol; sym != NULL; sym = sym->next)
        if (sym->name
                && strcmp (sym->name, blhe->root.string) == 0)
            return TRUE;

    return FALSE;
}
Esempio n. 2
0
int
main (int argc, char **argv)
{
  char *emulation;
  long start_time = get_run_time ();

#if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
  setlocale (LC_MESSAGES, "");
#endif
#if defined (HAVE_SETLOCALE)
  setlocale (LC_CTYPE, "");
#endif
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  program_name = argv[0];

  START_PROGRESS (program_name, 0);

  expandargv (&argc, &argv);

  bfd_init ();

  bfd_set_error_program_name (program_name);

  /* We want to notice and fail on those nasty BFD assertions which are
     likely to signal incorrect output being generated but otherwise may
     leave no trace.  */
  default_bfd_assert_handler = bfd_set_assert_handler (ld_bfd_assert_handler);

  /* Also hook the bfd error/warning handler for --fatal-warnings.  */
  default_bfd_error_handler = bfd_set_error_handler (ld_bfd_error_handler);

  xatexit (ld_cleanup);

  /* Set up the sysroot directory.  */
  ld_sysroot = get_sysroot (argc, argv);
  if (*ld_sysroot)
    ld_canon_sysroot = lrealpath (ld_sysroot);
  if (ld_canon_sysroot)
    {
      ld_canon_sysroot_len = strlen (ld_canon_sysroot);

      /* is_sysrooted_pathname() relies on no trailing dirsep.  */
      if (ld_canon_sysroot_len > 0
	  && IS_DIR_SEPARATOR (ld_canon_sysroot [ld_canon_sysroot_len - 1]))
        ld_canon_sysroot [--ld_canon_sysroot_len] = '\0';
    }
  else
    ld_canon_sysroot_len = -1;

  /* Set the default BFD target based on the configured target.  Doing
     this permits the linker to be configured for a particular target,
     and linked against a shared BFD library which was configured for
     a different target.  The macro TARGET is defined by Makefile.  */
  if (!bfd_set_default_target (TARGET))
    {
      einfo (_("%X%P: can't set BFD default target to `%s': %E\n"), TARGET);
      xexit (1);
    }

#if YYDEBUG
  {
    extern int yydebug;
    yydebug = 1;
  }
#endif

  config.build_constructors = TRUE;
  config.rpath_separator = ':';
  config.split_by_reloc = (unsigned) -1;
  config.split_by_file = (bfd_size_type) -1;
  config.make_executable = TRUE;
  config.magic_demand_paged = TRUE;
  config.text_read_only = TRUE;
  link_info.disable_target_specific_optimizations = -1;

  command_line.warn_mismatch = TRUE;
  command_line.warn_search_mismatch = TRUE;
  command_line.check_section_addresses = -1;

  /* We initialize DEMANGLING based on the environment variable
     COLLECT_NO_DEMANGLE.  The gcc collect2 program will demangle the
     output of the linker, unless COLLECT_NO_DEMANGLE is set in the
     environment.  Acting the same way here lets us provide the same
     interface by default.  */
  demangling = getenv ("COLLECT_NO_DEMANGLE") == NULL;

  link_info.allow_undefined_version = TRUE;
  link_info.keep_memory = TRUE;
  link_info.combreloc = TRUE;
  link_info.strip_discarded = TRUE;
  link_info.prohibit_multiple_definition_absolute = FALSE;
  link_info.emit_hash = DEFAULT_EMIT_SYSV_HASH;
  link_info.emit_gnu_hash = DEFAULT_EMIT_GNU_HASH;
  link_info.callbacks = &link_callbacks;
  link_info.input_bfds_tail = &link_info.input_bfds;
  /* SVR4 linkers seem to set DT_INIT and DT_FINI based on magic _init
     and _fini symbols.  We are compatible.  */
  link_info.init_function = "_init";
  link_info.fini_function = "_fini";
  link_info.relax_pass = 1;
  link_info.extern_protected_data = -1;
  link_info.dynamic_undefined_weak = -1;
  link_info.pei386_auto_import = -1;
  link_info.spare_dynamic_tags = 5;
  link_info.path_separator = ':';
#ifdef DEFAULT_FLAG_COMPRESS_DEBUG
  link_info.compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
#endif
#ifdef DEFAULT_NEW_DTAGS
  link_info.new_dtags = DEFAULT_NEW_DTAGS;
#endif

  ldfile_add_arch ("");
  emulation = get_emulation (argc, argv);
  ldemul_choose_mode (emulation);
  default_target = ldemul_choose_target (argc, argv);
  lang_init ();
  ldexp_init ();
  ldemul_before_parse ();
  lang_has_input_file = FALSE;
  parse_args (argc, argv);

  if (config.hash_table_size != 0)
    bfd_hash_set_default_size (config.hash_table_size);

  ldemul_set_symbols ();

  /* If we have not already opened and parsed a linker script,
     try the default script from command line first.  */
  if (saved_script_handle == NULL
      && command_line.default_script != NULL)
    {
      ldfile_open_command_file (command_line.default_script);
      parser_input = input_script;
      yyparse ();
    }

  /* If we have not already opened and parsed a linker script
     read the emulation's appropriate default script.  */
  if (saved_script_handle == NULL)
    {
      int isfile;
      char *s = ldemul_get_script (&isfile);

      if (isfile)
	ldfile_open_default_command_file (s);
      else
	{
	  lex_string = s;
	  lex_redirect (s, _("built in linker script"), 1);
	}
      parser_input = input_script;
      yyparse ();
      lex_string = NULL;
    }

  if (verbose)
    {
      if (saved_script_handle)
	info_msg (_("using external linker script:"));
      else
	info_msg (_("using internal linker script:"));
      info_msg ("\n==================================================\n");

      if (saved_script_handle)
	{
	  static const int ld_bufsz = 8193;
	  size_t n;
	  char *buf = (char *) malloc (ld_bufsz);

	  rewind (saved_script_handle);
	  while ((n = fread (buf, 1, ld_bufsz - 1, saved_script_handle)) > 0)
	    {
	      buf[n] = 0;
	      info_msg ("%s", buf);
	    }
	  rewind (saved_script_handle);
	  free (buf);
	}
      else
	{
	  int isfile;

	  info_msg (ldemul_get_script (&isfile));
	}

      info_msg ("\n==================================================\n");
    }

  if (command_line.force_group_allocation
      || !bfd_link_relocatable (&link_info))
    link_info.resolve_section_groups = TRUE;
  else
    link_info.resolve_section_groups = FALSE;

  if (command_line.print_output_format)
    info_msg ("%s\n", lang_get_output_target ());

  lang_final ();

  /* If the only command line argument has been -v or --version or --verbose
     then ignore any input files provided by linker scripts and exit now.
     We do not want to create an output file when the linker is just invoked
     to provide version information.  */
  if (argc == 2 && version_printed)
    xexit (0);

  if (link_info.inhibit_common_definition && !bfd_link_dll (&link_info))
    einfo (_("%F%P: --no-define-common may not be used without -shared\n"));

  if (!lang_has_input_file)
    {
      if (version_printed || command_line.print_output_format)
	xexit (0);
      einfo (_("%F%P: no input files\n"));
    }

  if (trace_files)
    info_msg (_("%P: mode %s\n"), emulation);

  ldemul_after_parse ();

  if (config.map_filename)
    {
      if (strcmp (config.map_filename, "-") == 0)
	{
	  config.map_file = stdout;
	}
      else
	{
	  config.map_file = fopen (config.map_filename, FOPEN_WT);
	  if (config.map_file == (FILE *) NULL)
	    {
	      bfd_set_error (bfd_error_system_call);
	      einfo (_("%F%P: cannot open map file %s: %E\n"),
		     config.map_filename);
	    }
	}
    }

  lang_process ();

  /* Print error messages for any missing symbols, for any warning
     symbols, and possibly multiple definitions.  */
  if (bfd_link_relocatable (&link_info))
    link_info.output_bfd->flags &= ~EXEC_P;
  else
    link_info.output_bfd->flags |= EXEC_P;

  if ((link_info.compress_debug & COMPRESS_DEBUG))
    {
      link_info.output_bfd->flags |= BFD_COMPRESS;
      if (link_info.compress_debug == COMPRESS_DEBUG_GABI_ZLIB)
	link_info.output_bfd->flags |= BFD_COMPRESS_GABI;
    }

  ldwrite ();

  if (config.map_file != NULL)
    lang_map ();
  if (command_line.cref)
    output_cref (config.map_file != NULL ? config.map_file : stdout);
  if (nocrossref_list != NULL)
    check_nocrossrefs ();
  if (command_line.print_memory_usage)
    lang_print_memory_usage ();
#if 0
  {
    struct bfd_link_hash_entry *h;

    h = bfd_link_hash_lookup (link_info.hash, "__image_base__", 0,0,1);
    fprintf (stderr, "lookup = %p val %lx\n", h, h ? h->u.def.value : 1);
  }
#endif
  ldexp_finish ();
  lang_finish ();

  /* Even if we're producing relocatable output, some non-fatal errors should
     be reported in the exit status.  (What non-fatal errors, if any, do we
     want to ignore for relocatable output?)  */
  if (!config.make_executable && !force_make_executable)
    {
      if (trace_files)
	einfo (_("%P: link errors found, deleting executable `%s'\n"),
	       output_filename);

      /* The file will be removed by ld_cleanup.  */
      xexit (1);
    }
  else
    {
      if (!bfd_close (link_info.output_bfd))
	einfo (_("%F%P: %pB: final close failed: %E\n"), link_info.output_bfd);

      /* If the --force-exe-suffix is enabled, and we're making an
	 executable file and it doesn't end in .exe, copy it to one
	 which does.  */
      if (!bfd_link_relocatable (&link_info)
	  && command_line.force_exe_suffix)
	{
	  int len = strlen (output_filename);

	  if (len < 4
	      || (strcasecmp (output_filename + len - 4, ".exe") != 0
		  && strcasecmp (output_filename + len - 4, ".dll") != 0))
	    {
	      FILE *src;
	      FILE *dst;
	      const int bsize = 4096;
	      char *buf = (char *) malloc (bsize);
	      int l;
	      char *dst_name = (char *) malloc (len + 5);

	      strcpy (dst_name, output_filename);
	      strcat (dst_name, ".exe");
	      src = fopen (output_filename, FOPEN_RB);
	      dst = fopen (dst_name, FOPEN_WB);

	      if (!src)
		einfo (_("%F%P: unable to open for source of copy `%s'\n"),
		       output_filename);
	      if (!dst)
		einfo (_("%F%P: unable to open for destination of copy `%s'\n"),
		       dst_name);
	      while ((l = fread (buf, 1, bsize, src)) > 0)
		{
		  int done = fwrite (buf, 1, l, dst);

		  if (done != l)
		    einfo (_("%P: error writing file `%s'\n"), dst_name);
		}

	      fclose (src);
	      if (fclose (dst) == EOF)
		einfo (_("%P: error closing file `%s'\n"), dst_name);
	      free (dst_name);
	      free (buf);
	    }
	}
    }

  END_PROGRESS (program_name);

  if (config.stats)
    {
      long run_time = get_run_time () - start_time;

      fflush (stdout);
      fprintf (stderr, _("%s: total time in link: %ld.%06ld\n"),
	       program_name, run_time / 1000000, run_time % 1000000);
      fflush (stderr);
    }

  /* Prevent ld_cleanup from doing anything, after a successful link.  */
  output_filename = NULL;

  xexit (0);
  return 0;
}