path: root/binutils/objcopy.c

/* objcopy.c -- copy object file from input to output, optionally massaging it.
   Copyright (C) 1991, 92, 93, 94 Free Software Foundation, Inc.

   This file is part of 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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "bfd.h"
#include "sysdep.h"
#include "bucomm.h"
#include <getopt.h>

static void setup_section ();
static void copy_section ();
static void mangle_section ();

#define nonfatal(s) {bfd_nonfatal(s); status = 1; return;}

static asymbol **isympp = NULL;	/* Input symbols */
static asymbol **osympp = NULL;	/* Output symbols that survive stripping */

/* If `copy_byte' >= 0, copy only that byte of every `interleave' bytes.  */
static int copy_byte = -1;
static int interleave = 4;

static boolean verbose;		/* Print file and target names. */
static int status = 0;		/* Exit status.  */

enum strip_action
  {
    strip_undef,
    strip_none,			/* don't strip */
    strip_debug,		/* strip all debugger symbols */
    strip_all			/* strip all symbols */
  };

/* Which symbols to remove. */
static enum strip_action strip_symbols;

enum locals_action
  {
    locals_undef,
    locals_start_L,		/* discard locals starting with L */
    locals_all			/* discard all locals */
  };

/* Which local symbols to remove.  Overrides strip_all.  */
static enum locals_action discard_locals;

/* Options to handle if running as "strip".  */

static struct option strip_options[] =
{
  {"discard-all", no_argument, 0, 'x'},
  {"discard-locals", no_argument, 0, 'X'},
  {"format", required_argument, 0, 'F'}, /* Obsolete */
  {"help", no_argument, 0, 'h'},
  {"input-format", required_argument, 0, 'I'}, /* Obsolete */
  {"input-target", required_argument, 0, 'I'},
  {"output-format", required_argument, 0, 'O'},	/* Obsolete */
  {"output-target", required_argument, 0, 'O'},
  {"strip-all", no_argument, 0, 's'},
  {"strip-debug", no_argument, 0, 'S'},
  {"target", required_argument, 0, 'F'},
  {"verbose", no_argument, 0, 'v'},
  {"version", no_argument, 0, 'V'},
  {0, no_argument, 0, 0}
};

/* Options to handle if running as "objcopy".  */

static struct option copy_options[] =
{
  {"byte", required_argument, 0, 'b'},
  {"discard-all", no_argument, 0, 'x'},
  {"discard-locals", no_argument, 0, 'X'},
  {"format", required_argument, 0, 'F'}, /* Obsolete */
  {"help", no_argument, 0, 'h'},
  {"input-format", required_argument, 0, 'I'}, /* Obsolete */
  {"input-target", required_argument, 0, 'I'},
  {"interleave", required_argument, 0, 'i'},
  {"output-format", required_argument, 0, 'O'},	/* Obsolete */
  {"output-target", required_argument, 0, 'O'},
  {"strip-all", no_argument, 0, 'S'},
  {"strip-debug", no_argument, 0, 'g'},
  {"target", required_argument, 0, 'F'},
  {"verbose", no_argument, 0, 'v'},
  {"version", no_argument, 0, 'V'},
  {0, no_argument, 0, 0}
};

/* IMPORTS */
extern char *program_name;
extern char *program_version;

/* This flag distinguishes between strip and objcopy:
   1 means this is 'strip'; 0 means this is 'objcopy'.
   -1 means if we should use argv[0] to decide. */
extern int is_strip;


static void
copy_usage (stream, status)
     FILE *stream;
     int status;
{
  fprintf (stream, "\
Usage: %s [-vVSgxX] [-I bfdname] [-O bfdname] [-F bfdname] [-b byte]\n\
       [-i interleave] [--interleave=interleave] [--byte=byte]\n\
       [--input-target=bfdname] [--output-target=bfdname] [--target=bfdname]\n\
       [--strip-all] [--strip-debug] [--discard-all] [--discard-locals]\n\
       [--verbose] [--version] [--help] in-file [out-file]\n",
	   program_name);
  exit (status);
}

static void
strip_usage (stream, status)
     FILE *stream;
     int status;
{
  fprintf (stream, "\
Usage: %s [-vVsSgxX] [-I bfdname] [-O bfdname] [-F bfdname]\n\
       [--input-target=bfdname] [--output-target=bfdname] [--target=bfdname]\n\
       [--strip-all] [--strip-debug] [--discard-all] [--discard-locals]\n\
       [--verbose] [--version] [--help] file...\n",
	   program_name);
  exit (status);
}


/* Return the name of a temporary file in the same directory as FILENAME.  */

static char *
make_tempname (filename)
     char *filename;
{
  static char template[] = "stXXXXXX";
  char *tmpname;
  char *slash = strrchr (filename, '/');

  if (slash != (char *) NULL)
    {
      *slash = 0;
      tmpname = xmalloc (strlen (filename) + sizeof (template) + 1);
      strcpy (tmpname, filename);
      strcat (tmpname, "/");
      strcat (tmpname, template);
      mktemp (tmpname);
      *slash = '/';
    }
  else
    {
      tmpname = xmalloc (sizeof (template));
      strcpy (tmpname, template);
      mktemp (tmpname);
    }
  return tmpname;
}

/* Choose which symbol entries to copy; put the result in OSYMS.
   We don't copy in place, because that confuses the relocs.
   Return the number of symbols to print.  */

static unsigned int
filter_symbols (abfd, osyms, isyms, symcount)
     bfd *abfd;
     asymbol **osyms, **isyms;
     unsigned long symcount;
{
  register asymbol **from = isyms, **to = osyms;
  char locals_prefix = bfd_get_symbol_leading_char (abfd) == '_' ? 'L' : '.';
  unsigned int src_count = 0, dst_count = 0;

  for (; src_count < symcount; src_count++)
    {
      asymbol *sym = from[src_count];
      flagword flags = sym->flags;
      int keep;

      if ((flags & BSF_GLOBAL)	/* Keep if external.  */
	  || bfd_get_section (sym) == &bfd_und_section
	  || bfd_is_com_section (bfd_get_section (sym)))
	keep = 1;
      else if ((flags & BSF_DEBUGGING) != 0)	/* Debugging symbol.  */
	keep = strip_symbols != strip_debug;
      else			/* Local symbol.  */
	keep = discard_locals != locals_all
	  && (discard_locals != locals_start_L ||
	      bfd_asymbol_name (sym)[0] != locals_prefix);
      if (keep)
	to[dst_count++] = sym;
    }

  return dst_count;
}

/* Keep only every `copy_byte'th byte in MEMHUNK, which is *SIZE bytes long.
   Adjust *SIZE.  */

void
filter_bytes (memhunk, size)
     char *memhunk;
     bfd_size_type *size;
{
  char *from = memhunk + copy_byte, *to = memhunk, *end = memhunk + *size;

  for (; from < end; from += interleave)
    *to++ = *from;
  *size /= interleave;
}

/* Copy object file IBFD onto OBFD.  */

static void
copy_object (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  unsigned int symcount;

  if (!bfd_set_format (obfd, bfd_get_format (ibfd)))
    {
      nonfatal (bfd_get_filename (obfd));
    }

  if (verbose)
    printf ("copy from %s(%s) to %s(%s)\n",
	    bfd_get_filename(ibfd), bfd_get_target(ibfd),
	    bfd_get_filename(obfd), bfd_get_target(obfd));

  if (!bfd_set_start_address (obfd, bfd_get_start_address (ibfd))
      || !bfd_set_file_flags (obfd,
			      (bfd_get_file_flags (ibfd)
			       & bfd_applicable_file_flags (obfd))))
    {
      nonfatal (bfd_get_filename (ibfd));
    }

  /* Copy architecture of input file to output file */
  if (!bfd_set_arch_mach (obfd, bfd_get_arch (ibfd),
			  bfd_get_mach (ibfd)))
    {
      fprintf (stderr, "Output file cannot represent architecture %s\n",
	       bfd_printable_arch_mach (bfd_get_arch (ibfd),
					bfd_get_mach (ibfd)));
    }
  if (!bfd_set_format (obfd, bfd_get_format (ibfd)))
    {
      nonfatal (bfd_get_filename(ibfd));
    }

  if (isympp)
    free (isympp);
  if (osympp != isympp)
    free (osympp);

  if (strip_symbols == strip_all && discard_locals == locals_undef)
    {
      osympp = isympp = NULL;
      symcount = 0;
    }
  else
    {
      osympp = isympp = (asymbol **) xmalloc (get_symtab_upper_bound (ibfd));
      symcount = bfd_canonicalize_symtab (ibfd, isympp);

      if (strip_symbols == strip_debug || discard_locals != locals_undef)
	{
	  osympp = (asymbol **) xmalloc (symcount * sizeof (asymbol *));
	  symcount = filter_symbols (ibfd, osympp, isympp, symcount);
	}
    }

  bfd_set_symtab (obfd, osympp, symcount);

  /* bfd mandates that all output sections be created and sizes set before
     any output is done.  Thus, we traverse all sections multiple times.  */
  bfd_map_over_sections (ibfd, setup_section, (void *) obfd);
  bfd_map_over_sections (ibfd, copy_section, (void *) obfd);
  bfd_map_over_sections (ibfd, mangle_section, (void *) obfd);
}

static char *
cat (a, b, c)
     char *a;
     char *b;
     char *c;
{
  size_t size = strlen (a) + strlen (b) + strlen (c);
  char *r = xmalloc (size + 1);

  strcpy (r, a);
  strcat (r, b);
  strcat (r, c);
  return r;
}

/* Read each archive element in turn from IBFD, copy the
   contents to temp file, and keep the temp file handle.  */

static void
copy_archive (ibfd, obfd, output_target)
     bfd *ibfd;
     bfd *obfd;
     char *output_target;
{
  bfd **ptr = &obfd->archive_head;
  bfd *this_element;
  char *dir = cat ("./#", make_tempname (""), "cd");

  /* Make a temp directory to hold the contents.  */
  mkdir (dir, 0777);
  obfd->has_armap = ibfd->has_armap;

  this_element = bfd_openr_next_archived_file (ibfd, NULL);
  ibfd->archive_head = this_element;
  while (this_element != (bfd *) NULL)
    {
      /* Create an output file for this member.  */
      char *output_name = cat (dir, "/", bfd_get_filename(this_element));
      bfd *output_bfd = bfd_openw (output_name, output_target);

      if (output_bfd == (bfd *) NULL)
	{
	  nonfatal (output_name);
	}
      if (!bfd_set_format (obfd, bfd_get_format (ibfd)))
	{
	  nonfatal (bfd_get_filename (obfd));
	}

      if (bfd_check_format (this_element, bfd_object) == true)
	{
	  copy_object (this_element, output_bfd);
	}

      bfd_close (output_bfd);
      /* Open the newly output file and attatch to our list.  */
      output_bfd = bfd_openr (output_name, output_target);

      /* Mark it for deletion.  */
      *ptr = output_bfd;
      ptr = &output_bfd->next;
      this_element->next = bfd_openr_next_archived_file (ibfd, this_element);
      this_element = this_element->next;
    }
  *ptr = (bfd *) NULL;

  if (!bfd_close (obfd))
    {
      nonfatal (bfd_get_filename (obfd));
    }

  /* Delete all the files that we opened.
     Construct their names again, unfortunately, but
     we're about to exit anyway.  */
  for (this_element = ibfd->archive_head;
       this_element != (bfd *) NULL;
       this_element = this_element->next)
    {
      unlink (cat (dir, "/", bfd_get_filename (this_element)));
    }
  rmdir (dir);
  if (!bfd_close (ibfd))
    {
      nonfatal (bfd_get_filename (ibfd));
    }
}

/* The top-level control.  */

static void
copy_file (input_filename, output_filename, input_target, output_target)
     char *input_filename;
     char *output_filename;
     char *input_target;
     char *output_target;
{
  bfd *ibfd;
  char **matching;

  /* To allow us to do "strip *" without dying on the first
     non-object file, failures are nonfatal.  */

  ibfd = bfd_openr (input_filename, input_target);
  if (ibfd == NULL)
    {
      nonfatal (input_filename);
    }

  if (bfd_check_format (ibfd, bfd_archive))
    {
      bfd *obfd = bfd_openw (output_filename, output_target);
      if (obfd == NULL)
	{
	  nonfatal (output_filename);
	}
      copy_archive (ibfd, obfd, output_target);
    }
  else if (bfd_check_format_matches (ibfd, bfd_object, &matching))
    {
      bfd *obfd = bfd_openw (output_filename, output_target);
      if (obfd == NULL)
	{
	  nonfatal (output_filename);
	}

      copy_object (ibfd, obfd);

      if (!bfd_close (obfd))
	{
	  nonfatal (output_filename);
	}

      if (!bfd_close (ibfd))
	{
	  nonfatal (input_filename);
	}
    }
  else
    {
      bfd_nonfatal (input_filename);
      if (bfd_error == file_ambiguously_recognized)
	{
	  list_matching_formats (matching);
	  free (matching);
	}
      status = 1;
    }
}

/* Create a section in OBFD with the same name and attributes
   as ISECTION in IBFD.  */

static void
setup_section (ibfd, isection, obfd)
     bfd *ibfd;
     sec_ptr isection;
     bfd *obfd;
{
  sec_ptr osection;
  char *err;

  if ((bfd_get_section_flags (ibfd, isection) & SEC_DEBUGGING) != 0
      && (strip_symbols == strip_debug
	  || strip_symbols == strip_all
	  || discard_locals == locals_all))
    return;

  osection = bfd_get_section_by_name (obfd, bfd_section_name (ibfd, isection));
  if (osection == NULL)
    {
      osection = bfd_make_section (obfd, bfd_section_name (ibfd, isection));
      if (osection == NULL)
	{
	  err = "making";
	  goto loser;
	}
    }

  if (!bfd_set_section_size (obfd,
			     osection,
			     bfd_section_size (ibfd, isection)))
    {
      err = "size";
      goto loser;
    }

  if (bfd_set_section_vma (obfd,
			   osection,
			   bfd_section_vma (ibfd, isection))
      == false)
    {
      err = "vma";
      goto loser;
    }

  if (bfd_set_section_alignment (obfd,
				 osection,
				 bfd_section_alignment (ibfd, isection))
      == false)
    {
      err = "alignment";
      goto loser;
    }

  if (!bfd_set_section_flags (obfd, osection,
			      bfd_get_section_flags (ibfd, isection)))
    {
      err = "flags";
      goto loser;
    }

  /* All went well */
  return;

loser:
  fprintf (stderr, "%s: %s: section `%s': error in %s: %s\n",
	   program_name,
	   bfd_get_filename (ibfd), bfd_section_name (ibfd, isection),
	   err, bfd_errmsg (bfd_error));
  status = 1;
}

/* Copy the data of input section ISECTION of IBFD
   to an output section with the same name in OBFD.
   If stripping then don't copy any relocation info.  */

static void
copy_section (ibfd, isection, obfd)
     bfd *ibfd;
     sec_ptr isection;
     bfd *obfd;
{
  arelent **relpp;
  int relcount;
  sec_ptr osection;
  bfd_size_type size;

  if ((bfd_get_section_flags (ibfd, isection) & SEC_DEBUGGING) != 0
      && (strip_symbols == strip_debug
	  || strip_symbols == strip_all
	  || discard_locals == locals_all))
    {
      return;
    }

  osection = bfd_get_section_by_name (obfd,
				      bfd_section_name (ibfd, isection));

  size = bfd_get_section_size_before_reloc (isection);

  if (size == 0)
    return;

  if (strip_symbols == strip_all
      || bfd_get_reloc_upper_bound (ibfd, isection) == 0)
    {
      bfd_set_reloc (obfd, osection, (arelent **) NULL, 0);
    }
  else
    {
      relpp = (arelent **) xmalloc (bfd_get_reloc_upper_bound (ibfd, isection));
      relcount = bfd_canonicalize_reloc (ibfd, isection, relpp, isympp);
      bfd_set_reloc (obfd, osection, relpp, relcount);
    }

  isection->_cooked_size = isection->_raw_size;
  isection->reloc_done = true;

  if (bfd_get_section_flags (ibfd, isection) & SEC_HAS_CONTENTS)
    {
      PTR memhunk = (PTR) xmalloc ((unsigned) size);

      if (!bfd_get_section_contents (ibfd, isection, memhunk, (file_ptr) 0,
				     size))
	{
	  nonfatal (bfd_get_filename (ibfd));
	}

      if (copy_byte >= 0)
	filter_bytes (memhunk, &size);

      if (!bfd_set_section_contents (obfd, osection, memhunk, (file_ptr) 0,
				     size))
	{
	  nonfatal (bfd_get_filename (obfd));
	}
      free (memhunk);
    }
}

/* All the symbols have been read in and point to their owning input section.
   They have been relocated so that they are all relative to the base of
   their owning section.  On the way out, all the symbols will be relocated to
   their new location in the output file, through some complex sums.  */

static void
mangle_section (ibfd, p, obfd)
     bfd *ibfd;
     asection *p;
     bfd *obfd;
{
  p->output_section = bfd_get_section_by_name (obfd, p->name);
  p->output_offset = 0;
}

/* The number of bytes to copy at once.  */
#define COPY_BUF 8192

/* Copy file FROM to file TO, performing no translations.
   Return 0 if ok, -1 if error.  */

static int
simple_copy (from, to)
     char *from, *to;
{
  int fromfd, tofd, nread;
  char buf[COPY_BUF];

  fromfd = open (from, O_RDONLY);
  if (fromfd < 0)
    return -1;
  tofd = open (to, O_WRONLY | O_CREAT | O_TRUNC);
  if (tofd < 0)
    {
      close (fromfd);
      return -1;
    }
  while ((nread = read (fromfd, buf, sizeof buf)) > 0)
    {
      if (write (tofd, buf, nread) != nread)
	{
	  close (fromfd);
	  close (tofd);
	  return -1;
	}
    }
  close (fromfd);
  close (tofd);
  if (nread < 0)
    return -1;
  return 0;
}

#ifndef S_ISLNK
#ifdef S_IFLNK
#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#else
#define S_ISLNK(m) 0
#define lstat stat
#endif
#endif

/* Rename FROM to TO, copying if TO is a link.
   Assumes that TO already exists, because FROM is a temp file.
   Return 0 if ok, -1 if error.  */

static int
smart_rename (from, to)
     char *from, *to;
{
  struct stat s;
  int ret = 0;

  if (lstat (to, &s))
    return -1;

  /* Use rename only if TO is not a symbolic link and has
     only one hard link.  */
  if (!S_ISLNK (s.st_mode) && s.st_nlink == 1)
    {
      ret = rename (from, to);
      if (ret == 0)
	{
	  /* Try to preserve the permission bits and ownership of TO.  */
	  chmod (to, s.st_mode & 07777);
	  chown (to, s.st_uid, s.st_gid);
	}
    }
  else
    {
      ret = simple_copy (from, to);
      if (ret == 0)
	unlink (from);
    }
  return ret;
}

static int
strip_main (argc, argv)
     int argc;
     char *argv[];
{
  char *input_target = NULL, *output_target = NULL;
  boolean show_version = false;
  int c, i;

  while ((c = getopt_long (argc, argv, "I:O:F:sSgxXVv",
			   strip_options, (int *) 0)) != EOF)
    {
      switch (c)
	{
	case 'I':
	  input_target = optarg;
	  break;
	case 'O':
	  output_target = optarg;
	  break;
	case 'F':
	  input_target = output_target = optarg;
	  break;
	case 's':
	  strip_symbols = strip_all;
	  break;
	case 'S':
	case 'g':
	  strip_symbols = strip_debug;
	  break;
	case 'x':
	  discard_locals = locals_all;
	  break;
	case 'X':
	  discard_locals = locals_start_L;
	  break;
	case 'v':
	  verbose = true;
	  break;
	case 'V':
	  show_version = true;
	  break;
	case 0:
	  break;		/* we've been given a long option */
	case 'h':
	  strip_usage (stdout, 0);
	default:
	  strip_usage (stderr, 1);
	}
    }

  if (show_version)
    {
      printf ("GNU %s version %s\n", program_name, program_version);
      exit (0);
    }

  /* Default is to strip all symbols.  */
  if (strip_symbols == strip_undef && discard_locals == locals_undef)
    strip_symbols = strip_all;

  if (output_target == (char *) NULL)
    output_target = input_target;

  i = optind;
  if (i == argc)
    strip_usage (stderr, 1);

  for (; i < argc; i++)
    {
      int hold_status = status;

      char *tmpname = make_tempname (argv[i]);
      status = 0;
      copy_file (argv[i], tmpname, input_target, output_target);
      if (status == 0)
	{
	  smart_rename (tmpname, argv[i]);
	  status = hold_status;
	}
      else
	unlink (tmpname);
      free (tmpname);
    }

  return 0;
}

static int
copy_main (argc, argv)
     int argc;
     char *argv[];
{
  char *input_filename, *output_filename;
  char *input_target = NULL, *output_target = NULL;
  boolean show_version = false;
  int c;

  while ((c = getopt_long (argc, argv, "b:i:I:s:O:d:F:SgxXVv",
			   copy_options, (int *) 0)) != EOF)
    {
      switch (c)
	{
	case 'b':
	  copy_byte = atoi(optarg);
	  if (copy_byte < 0)
	    {
	      fprintf (stderr, "%s: byte number must be non-negative\n",
		       program_name);
	      exit (1);
	    }
	  break;
	case 'i':
	  interleave = atoi(optarg);
	  if (interleave < 1)
	    {
	      fprintf(stderr, "%s: interleave must be positive\n",
		      program_name);
	      exit (1);
	    }
	  break;
	case 'I':
	case 's':		/* "source" - 'I' is preferred */
	  input_target = optarg;
	  break;
	case 'O':
	case 'd':		/* "destination" - 'O' is preferred */
	  output_target = optarg;
	  break;
	case 'F':
	  input_target = output_target = optarg;
	  break;
	case 'S':
	  strip_symbols = strip_all;
	  break;
	case 'g':
	  strip_symbols = strip_debug;
	  break;
	case 'x':
	  discard_locals = locals_all;
	  break;
	case 'X':
	  discard_locals = locals_start_L;
	  break;
	case 'v':
	  verbose = true;
	  break;
	case 'V':
	  show_version = true;
	  break;
	case 0:
	  break;		/* we've been given a long option */
	case 'h':
	  copy_usage (stdout, 0);
	default:
	  copy_usage (stderr, 1);
	}
    }

  if (show_version)
    {
      printf ("GNU %s version %s\n", program_name, program_version);
      exit (0);
    }

  if (copy_byte >= interleave)
    {
      fprintf (stderr, "%s: byte number must be less than interleave\n",
	       program_name);
      exit (1);
    }

  if (optind == argc || optind + 2 < argc)
    copy_usage (stderr, 1);

  input_filename = argv[optind];
  if (optind + 1 < argc)
    output_filename = argv[optind + 1];

  /* Default is to strip no symbols.  */
  if (strip_symbols == strip_undef && discard_locals == locals_undef)
    strip_symbols = strip_none;

  if (output_target == (char *) NULL)
    output_target = input_target;

  /* If there is no destination file then create a temp and rename
     the result into the input.  */

  if (output_filename == (char *) NULL)
    {
      char *tmpname = make_tempname (input_filename);
      copy_file (input_filename, tmpname, input_target, output_target);
      if (status == 0)
	smart_rename (tmpname, input_filename);
      else
	unlink (tmpname);
    }
  else
    {
      copy_file (input_filename, output_filename, input_target, output_target);
    }

  return 0;
}

int
main (argc, argv)
     int argc;
     char *argv[];
{
  program_name = argv[0];
  xmalloc_set_program_name (program_name);
  strip_symbols = strip_undef;
  discard_locals = locals_undef;

  bfd_init ();

  if (is_strip < 0)
    {
      int i = strlen (program_name);
      is_strip = (i >= 5 && strcmp (program_name + i - 5, "strip"));
    }

  if (is_strip)
    strip_main (argc, argv);
  else
    copy_main (argc, argv);

  return status;
}