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/* Main program of GNU linker.

   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,

   2002, 2003, 2004, 2005, 2006, 2007, 2008

   Free Software Foundation, Inc.

   Written by Steve Chamberlain steve@cygnus.com

   This file is part of the GNU Binutils.

   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"

#include "safe-ctype.h"

#include "libiberty.h"

#include "progress.h"

#include "bfdlink.h"

#include "filenames.h"

#include "ld.h"

#include "ldmain.h"

#include "ldmisc.h"

#include "ldwrite.h"

#include "ldexp.h"

#include "ldlang.h"

#include <ldgram.h>

#include "ldlex.h"

#include "ldfile.h"

#include "ldemul.h"

#include "ldctor.h"

/* Somewhere above, sys/stat.h got included.  */

#if !defined(S_ISDIR) && defined(S_IFDIR)

#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)

#endif

#include <string.h>

#ifdef HAVE_SBRK

#if !HAVE_DECL_SBRK

extern void *sbrk ();

#endif

#endif

#ifndef TARGET_SYSTEM_ROOT

#define TARGET_SYSTEM_ROOT ""

#endif

/* EXPORTS */

FILE *saved_script_handle = NULL;

FILE *previous_script_handle = NULL;

bfd_boolean force_make_executable = FALSE;

char *default_target;

const char *output_filename = "a.out";

/* Name this program was invoked by.  */

char *program_name;

/* The prefix for system library directories.  */

const char *ld_sysroot;

/* The canonical representation of ld_sysroot.  */

char * ld_canon_sysroot;

int ld_canon_sysroot_len;

/* Set by -G argument, for MIPS ECOFF target.  */

int g_switch_value = 8;

/* Nonzero means print names of input files as processed.  */

bfd_boolean trace_files;

/* Nonzero means same, but note open failures, too.  */

bfd_boolean trace_file_tries;

/* Nonzero means version number was printed, so exit successfully

   instead of complaining if no input files are given.  */

bfd_boolean version_printed;

/* Nonzero means link in every member of an archive.  */

bfd_boolean whole_archive;

/* Nonzero means create DT_NEEDED entries only if a dynamic library

   actually satisfies some reference in a regular object.  */

bfd_boolean as_needed;

/* Nonzero means never create DT_NEEDED entries for dynamic libraries

   in DT_NEEDED tags.  */

bfd_boolean add_needed = TRUE;

/* TRUE if we should demangle symbol names.  */

bfd_boolean demangling;

args_type command_line;

ld_config_type config;

sort_type sort_section;

static const char *get_sysroot

  (int, char **);

static char *get_emulation

  (int, char **);

static bfd_boolean add_archive_element

  (struct bfd_link_info *, bfd *, const char *);

static bfd_boolean multiple_definition

  (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma,

   bfd *, asection *, bfd_vma);

static bfd_boolean multiple_common

  (struct bfd_link_info *, const char *, bfd *, enum bfd_link_hash_type,

   bfd_vma, bfd *, enum bfd_link_hash_type, bfd_vma);

static bfd_boolean add_to_set

  (struct bfd_link_info *, struct bfd_link_hash_entry *,

   bfd_reloc_code_real_type, bfd *, asection *, bfd_vma);

static bfd_boolean constructor_callback

  (struct bfd_link_info *, bfd_boolean, const char *, bfd *,

   asection *, bfd_vma);

static bfd_boolean warning_callback

  (struct bfd_link_info *, const char *, const char *, bfd *,

   asection *, bfd_vma);

static void warning_find_reloc

  (bfd *, asection *, void *);

static bfd_boolean undefined_symbol

  (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma,

   bfd_boolean);

static bfd_boolean reloc_overflow

  (struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,

   const char *, bfd_vma, bfd *, asection *, bfd_vma);

static bfd_boolean reloc_dangerous

  (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);

static bfd_boolean unattached_reloc

  (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);

static bfd_boolean notice

  (struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma);

static struct bfd_link_callbacks link_callbacks =

{

  add_archive_element,

  multiple_definition,

  multiple_common,

  add_to_set,

  constructor_callback,

  warning_callback,

  undefined_symbol,

  reloc_overflow,

  reloc_dangerous,

  unattached_reloc,

  notice,

  einfo,

  info_msg,

  minfo,

  ldlang_override_segment_assignment

};

struct bfd_link_info link_info;

static void

remove_output (void)

{

  if (output_filename)

    {

      if (link_info.output_bfd)

        bfd_cache_close (link_info.output_bfd);

      if (delete_output_file_on_failure)

        unlink_if_ordinary (output_filename);

    }

}

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];

  xmalloc_set_program_name (program_name);

  START_PROGRESS (program_name, 0);

  expandargv (&argc, &argv);

  bfd_init ();

  bfd_set_error_program_name (program_name);

  xatexit (remove_output);

  /* Set up the sysroot directory.  */

  ld_sysroot = get_sysroot (argc, argv);

  if (*ld_sysroot)

    {

      if (*TARGET_SYSTEM_ROOT == 0)

        {

          einfo ("%P%F: this linker was not configured to use sysroots\n");

          ld_sysroot = "";

        }

      else

        ld_canon_sysroot = lrealpath (ld_sysroot);

    }

  if (ld_canon_sysroot)

    ld_canon_sysroot_len = strlen (ld_canon_sysroot);

  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;

  command_line.warn_mismatch = TRUE;

  command_line.warn_search_mismatch = TRUE;

  command_line.check_section_addresses = TRUE;

  /* 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.emit_hash = TRUE;

  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.pei386_auto_import = -1;

  link_info.spare_dynamic_tags = 5;

  link_info.path_separator = ':';

  ldfile_add_arch ("");

  emulation = get_emulation (argc, argv);

  ldemul_choose_mode (emulation);

  default_target = ldemul_choose_target (argc, argv);

  lang_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 (link_info.relocatable)

    {

      if (command_line.relax)

        einfo (_("%P%F: --relax and -r may not be used together\n"));

      if (link_info.shared)

        einfo (_("%P%F: -r and -shared may not be used together\n"));

    }

  /* We may have -Bsymbolic, -Bsymbolic-functions, --dynamic-list-data,

     --dynamic-list-cpp-new, --dynamic-list-cpp-typeinfo and

     --dynamic-list FILE.  -Bsymbolic and -Bsymbolic-functions are

     for shared libraries.  -Bsymbolic overrides all others and vice

     versa.  */

  switch (command_line.symbolic)

    {

    case symbolic_unset:

      break;

    case symbolic:

      /* -Bsymbolic is for shared library only.  */

      if (link_info.shared)

        {

          link_info.symbolic = TRUE;

          /* Should we free the unused memory?  */

          link_info.dynamic_list = NULL;

          command_line.dynamic_list = dynamic_list_unset;

        }

      break;

    case symbolic_functions:

      /* -Bsymbolic-functions is for shared library only.  */

      if (link_info.shared)

        command_line.dynamic_list = dynamic_list_data;

      break;

    }

  switch (command_line.dynamic_list)

    {

    case dynamic_list_unset:

      break;

    case dynamic_list_data:

      link_info.dynamic_data = TRUE;

    case dynamic_list:

      link_info.dynamic = TRUE;

      break;

    }

  if (! link_info.shared)

    {

      if (command_line.filter_shlib)

        einfo (_("%P%F: -F may not be used without -shared\n"));

      if (command_line.auxiliary_filters)

        einfo (_("%P%F: -f may not be used without -shared\n"));

    }

  if (! link_info.shared || link_info.pie)

    link_info.executable = TRUE;

  /* Treat ld -r -s as ld -r -S -x (i.e., strip all local symbols).  I

     don't see how else this can be handled, since in this case we

     must preserve all externally visible symbols.  */

  if (link_info.relocatable && link_info.strip == strip_all)

    {

      link_info.strip = strip_debugger;

      if (link_info.discard == discard_sec_merge)

        link_info.discard = discard_all;

    }

  /* 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_command_file (s);

      else

        {

          lex_string = s;

          lex_redirect (s);

        }

      parser_input = input_script;

      yyparse ();

      lex_string = NULL;

    }

  if (trace_file_tries)

    {

      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 = xmalloc (ld_bufsz);

          rewind (saved_script_handle);

          while ((n = fread (buf, 1, ld_bufsz - 1, saved_script_handle)) > 0)

            {

              buf[n] = 0;

              info_msg (buf);

            }

          rewind (saved_script_handle);

          free (buf);

        }

      else

        {

          int isfile;

          info_msg (ldemul_get_script (&isfile));

        }

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

    }

  lang_final ();

  if (!lang_has_input_file)

    {

      if (version_printed)

        xexit (0);

      einfo (_("%P%F: 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 (_("%P%F: 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 (link_info.relocatable)

    link_info.output_bfd->flags &= ~EXEC_P;

  else

    link_info.output_bfd->flags |= EXEC_P;

  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 ();

  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 remove_output.  */

      xexit (1);

    }

  else

    {

      if (! bfd_close (link_info.output_bfd))

        einfo (_("%F%B: 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 (! link_info.relocatable && 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 = xmalloc (bsize);

              int l;

              char *dst_name = xmalloc (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 (_("%X%P: unable to open for source of copy `%s'\n"),

                       output_filename);

              if (!dst)

                einfo (_("%X%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)

    {

#ifdef HAVE_SBRK

      char *lim = sbrk (0);

#endif

      long run_time = get_run_time () - start_time;

      fprintf (stderr, _("%s: total time in link: %ld.%06ld\n"),

               program_name, run_time / 1000000, run_time % 1000000);

#ifdef HAVE_SBRK

      fprintf (stderr, _("%s: data size %ld\n"), program_name,

               (long) (lim - (char *) &environ));

#endif

    }

  /* Prevent remove_output from doing anything, after a successful link.  */

  output_filename = NULL;

  xexit (0);

  return 0;

}

/* If the configured sysroot is relocatable, try relocating it based on

   default prefix FROM.  Return the relocated directory if it exists,

   otherwise return null.  */

static char *

get_relative_sysroot (const char *from ATTRIBUTE_UNUSED)

{

#ifdef TARGET_SYSTEM_ROOT_RELOCATABLE

  char *path;

  struct stat s;

  path = make_relative_prefix (program_name, from, TARGET_SYSTEM_ROOT);

  if (path)

    {

      if (stat (path, &s) == 0 && S_ISDIR (s.st_mode))

        return path;

      free (path);

    }

#endif

  return 0;

}

/* Return the sysroot directory.  Return "" if no sysroot is being used.  */

static const char *

get_sysroot (int argc, char **argv)

{

  int i;

  const char *path;

  for (i = 1; i < argc; i++)

    if (CONST_STRNEQ (argv[i], "--sysroot="))

      return argv[i] + strlen ("--sysroot=");

  path = get_relative_sysroot (BINDIR);

  if (path)

    return path;

  path = get_relative_sysroot (TOOLBINDIR);

  if (path)

    return path;

  return TARGET_SYSTEM_ROOT;

}

/* We need to find any explicitly given emulation in order to initialize the

   state that's needed by the lex&yacc argument parser (parse_args).  */

static char *

get_emulation (int argc, char **argv)

{

  char *emulation;

  int i;

  emulation = getenv (EMULATION_ENVIRON);

  if (emulation == NULL)

    emulation = DEFAULT_EMULATION;

  for (i = 1; i < argc; i++)

    {

      if (CONST_STRNEQ (argv[i], "-m"))

        {

          if (argv[i][2] == '\0')

            {

              /* -m EMUL */

              if (i < argc - 1)

                {

                  emulation = argv[i + 1];

                  i++;

                }

              else

                einfo (_("%P%F: missing argument to -m\n"));

            }

          else if (strcmp (argv[i], "-mips1") == 0

                   || strcmp (argv[i], "-mips2") == 0

                   || strcmp (argv[i], "-mips3") == 0

                   || strcmp (argv[i], "-mips4") == 0

                   || strcmp (argv[i], "-mips5") == 0

                   || strcmp (argv[i], "-mips32") == 0

                   || strcmp (argv[i], "-mips32r2") == 0

                   || strcmp (argv[i], "-mips64") == 0

                   || strcmp (argv[i], "-mips64r2") == 0)

            {

              /* FIXME: The arguments -mips1, -mips2, -mips3, etc. are

                 passed to the linker by some MIPS compilers.  They

                 generally tell the linker to use a slightly different

                 library path.  Perhaps someday these should be

                 implemented as emulations; until then, we just ignore

                 the arguments and hope that nobody ever creates

                 emulations named ips1, ips2 or ips3.  */

            }

          else if (strcmp (argv[i], "-m486") == 0)

            {

              /* FIXME: The argument -m486 is passed to the linker on

                 some Linux systems.  Hope that nobody creates an

                 emulation named 486.  */

            }

          else

            {

              /* -mEMUL */

              emulation = &argv[i][2];

            }

        }

    }

  return emulation;

}

void

add_ysym (const char *name)

{

  if (link_info.notice_hash == NULL)

    {

      link_info.notice_hash = xmalloc (sizeof (struct bfd_hash_table));

      if (!bfd_hash_table_init_n (link_info.notice_hash,

                                  bfd_hash_newfunc,

                                  sizeof (struct bfd_hash_entry),

                                  61))

        einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));

    }

  if (bfd_hash_lookup (link_info.notice_hash, name, TRUE, TRUE) == NULL)

    einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));

}

/* Record a symbol to be wrapped, from the --wrap option.  */

void

add_wrap (const char *name)