ldmain.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 1,328 行 · 第 1/3 页

/* Main program of GNU linker.
   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
   Free Software Foundation, Inc.
   Written by Steve Chamberlain [e-mail]

This file is part of GLD, the Gnu Linker.

GLD 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 2, or (at your option)
any later version.

GLD 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 GLD; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#include "bfd.h"
#include "sysdep.h"
#include <stdio.h>
#include <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 "ldgram.h"
#include "ldexp.h"
#include "ldlang.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
#ifdef NEED_DECLARATION_SBRK
extern PTR sbrk ();
#endif
#endif

static char *get_emulation PARAMS ((int, char **));
static void set_scripts_dir PARAMS ((void));

/* EXPORTS */

char *default_target;
const char *output_filename = "a.out";

/* Name this program was invoked by.  */
char *program_name;

/* The file that we're creating.  */
bfd *output_bfd = 0;

/* Set by -G argument, for MIPS ECOFF target.  */
int g_switch_value = 8;

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

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

/* Nonzero means version number was printed, so exit successfully
   instead of complaining if no input files are given.  */
boolean version_printed;

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

/* True if we should demangle symbol names.  */
boolean demangling;

args_type command_line;

ld_config_type config;

static void remove_output PARAMS ((void));
static boolean check_for_scripts_dir PARAMS ((char *dir));
static boolean add_archive_element PARAMS ((struct bfd_link_info *, bfd *,
					    const char *));
static boolean multiple_definition PARAMS ((struct bfd_link_info *,
					    const char *,
					    bfd *, asection *, bfd_vma,
					    bfd *, asection *, bfd_vma));
static boolean multiple_common PARAMS ((struct bfd_link_info *,
					const char *, bfd *,
					enum bfd_link_hash_type, bfd_vma,
					bfd *, enum bfd_link_hash_type,
					bfd_vma));
static boolean add_to_set PARAMS ((struct bfd_link_info *,
				   struct bfd_link_hash_entry *,
				   bfd_reloc_code_real_type,
				   bfd *, asection *, bfd_vma));
static boolean constructor_callback PARAMS ((struct bfd_link_info *,
					     boolean constructor,
					     const char *name,
					     bfd *, asection *, bfd_vma));
static boolean warning_callback PARAMS ((struct bfd_link_info *,
					 const char *, const char *, bfd *,
					 asection *, bfd_vma));
static void warning_find_reloc PARAMS ((bfd *, asection *, PTR));
static boolean undefined_symbol PARAMS ((struct bfd_link_info *,
					 const char *, bfd *,
					 asection *, bfd_vma, boolean));
static boolean reloc_overflow PARAMS ((struct bfd_link_info *, const char *,
				       const char *, bfd_vma,
				       bfd *, asection *, bfd_vma));
static boolean reloc_dangerous PARAMS ((struct bfd_link_info *, const char *,
					bfd *, asection *, bfd_vma));
static boolean unattached_reloc PARAMS ((struct bfd_link_info *,
					 const char *, bfd *, asection *,
					 bfd_vma));
static boolean notice PARAMS ((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
};

struct bfd_link_info link_info;

static void
remove_output ()
{
  if (output_filename)
    {
      if (output_bfd && output_bfd->iostream)
	fclose ((FILE *) (output_bfd->iostream));
      if (delete_output_file_on_failure)
	unlink (output_filename);
    }
}

int
main (argc, argv)
     int argc;
     char **argv;
{
  char *emulation;
  long start_time = get_run_time ();

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

  program_name = argv[0];
  xmalloc_set_program_name (program_name);

  START_PROGRESS (program_name, 0);

  bfd_init ();

  bfd_set_error_program_name (program_name);

  xatexit (remove_output);

  /* 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);
    }

  /* Initialize the data about options.  */
  trace_files = trace_file_tries = version_printed = false;
  whole_archive = false;
  config.build_constructors = true;
  config.dynamic_link = false;
  config.has_shared = false;
  config.split_by_reloc = (unsigned) -1;
  config.split_by_file = (bfd_size_type) -1;
  command_line.force_common_definition = false;
  command_line.interpreter = NULL;
  command_line.rpath = NULL;
  command_line.warn_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.callbacks = &link_callbacks;
  link_info.relocateable = false;
  link_info.emitrelocations = false;
  link_info.shared = false;
  link_info.symbolic = false;
  link_info.static_link = false;
  link_info.traditional_format = false;
  link_info.optimize = false;
  link_info.no_undefined = false;
  link_info.allow_shlib_undefined = false;
  link_info.strip = strip_none;
  link_info.discard = discard_none;
  link_info.keep_memory = true;
  link_info.input_bfds = NULL;
  link_info.create_object_symbols_section = NULL;
  link_info.hash = NULL;
  link_info.keep_hash = NULL;
  link_info.notice_all = false;
  link_info.notice_hash = NULL;
  link_info.wrap_hash = NULL;
  link_info.mpc860c0 = 0;
  /* 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.new_dtags = false;
  link_info.flags = (bfd_vma) 0;
  link_info.flags_1 = (bfd_vma) 0;

  ldfile_add_arch ("");

  config.make_executable = true;
  force_make_executable = false;
  config.magic_demand_paged = true;
  config.text_read_only = true;

  emulation = get_emulation (argc, argv);
  ldemul_choose_mode (emulation);
  default_target = ldemul_choose_target ();
  lang_init ();
  ldemul_before_parse ();
  lang_has_input_file = false;
  parse_args (argc, argv);

  ldemul_set_symbols ();

  if (link_info.relocateable)
    {
      if (command_line.gc_sections)
	einfo ("%P%F: --gc-sections and -r may not be used together\n");
      if (link_info.mpc860c0)
	einfo (_("%P%F: -r and --mpc860c0 may not be used together\n"));
      else 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"));
    }

  /* 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.relocateable && link_info.strip == strip_all)
    {
      link_info.strip = strip_debugger;
      if (link_info.discard == discard_none)
	link_info.discard = discard_all;
    }

  /* This essentially adds another -L directory so this must be done after
     the -L's in argv have been processed.  */
  set_scripts_dir ();

  if (had_script == false)
    {
      /* Read the emulation's appropriate default script.  */
      int isfile;
      char *s = ldemul_get_script (&isfile);

      if (isfile)
	ldfile_open_command_file (s);
      else
	{
	  if (trace_file_tries)
	    {
	      info_msg (_("using internal linker script:\n"));
	      info_msg ("==================================================\n");
	      info_msg (s);
	      info_msg ("\n==================================================\n");
	    }
	  lex_string = s;
	  lex_redirect (s);
	}
      parser_input = input_script;
      yyparse ();
      lex_string = NULL;
    }

  lang_final ();

  if (lang_has_input_file == false)
    {
      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.relocateable)
    {
      /* Look for a text section and switch the readonly attribute in it.  */
      asection *found = bfd_get_section_by_name (output_bfd, ".text");

      if (found != (asection *) NULL)
	{
	  if (config.text_read_only)
	    found->flags |= SEC_READONLY;
	  else
	    found->flags &= ~SEC_READONLY;
	}
    }

  if (link_info.relocateable)
    output_bfd->flags &= ~EXEC_P;
  else
    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 ();

  /* Even if we're producing relocateable output, some non-fatal errors should
     be reported in the exit status.  (What non-fatal errors, if any, do we
     want to ignore for relocateable output?)  */

  if (config.make_executable == false && force_make_executable == false)
    {
      if (trace_files == true)
	{
	  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 (output_bfd))
	einfo (_("%F%B: final close failed: %E\n"), 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.relocateable && 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);
	    }
	}