/* BFD back-end for binary objects.

   Copyright (C) 1994-2023 Free Software Foundation, Inc.

   Written by Ian Lance Taylor, Cygnus Support, <ian@cygnus.com>

   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.  */

/* This is a BFD backend which may be used to read or write binary

   objects.  Historically, it was used as an output format for objcopy

   in order to generate raw binary data, but is now used for other

   purposes as well.

   This is very simple.  The only complication is that the real data

   will start at some address X, and in some cases we will not want to

   include X zeroes just to get to that point.  Since the start

   address is not meaningful for this object file format, we use it

   instead to indicate the number of zeroes to skip at the start of

   the file.  objcopy cooperates by specially setting the start

   address to zero by default.  */

#include "sysdep.h"

#include "bfd.h"

#include "safe-ctype.h"

#include "libbfd.h"

/* Any bfd we create by reading a binary file has three symbols:

   a start symbol, an end symbol, and an absolute length symbol.  */

#define BIN_SYMS 3

/* Create a binary object.  Invoked via bfd_set_format.  */

static bool

binary_mkobject (bfd *abfd ATTRIBUTE_UNUSED)

{

  return true;

}

/* Any file may be considered to be a binary file, provided the target

   was not defaulted.  That is, it must be explicitly specified as

   being binary.  */

static bfd_cleanup

binary_object_p (bfd *abfd)

{

  struct stat statbuf;

  asection *sec;

  flagword flags;

  if (abfd->target_defaulted)

    {

      bfd_set_error (bfd_error_wrong_format);

      return NULL;

    }

  abfd->symcount = BIN_SYMS;

  /* Find the file size.  */

  if (bfd_stat (abfd, &statbuf) < 0)

    {

      bfd_set_error (bfd_error_system_call);

      return NULL;

    }

  /* One data section.  */

  flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS;

  sec = bfd_make_section_with_flags (abfd, ".data", flags);

  if (sec == NULL)

    return NULL;

  sec->vma = 0;

  sec->size = statbuf.st_size;

  sec->filepos = 0;

  abfd->tdata.any = (void *) sec;

  return _bfd_no_cleanup;

}

#define binary_close_and_cleanup     _bfd_generic_close_and_cleanup

#define binary_bfd_free_cached_info  _bfd_generic_bfd_free_cached_info

#define binary_new_section_hook      _bfd_generic_new_section_hook

/* Get contents of the only section.  */

static bool

binary_get_section_contents (bfd *abfd,

           asection *section,

           void * location,

           file_ptr offset,

           bfd_size_type count)

{

  if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0

      || bfd_read (location, count, abfd) != count)

    return false;

  return true;

}

/* Return the amount of memory needed to read the symbol table.  */

static long

binary_get_symtab_upper_bound (bfd *abfd ATTRIBUTE_UNUSED)

{

  return (BIN_SYMS + 1) * sizeof (asymbol *);

}

/* Create a symbol name based on the bfd's filename.  */

static char *

mangle_name (bfd *abfd, char *suffix)

{

  bfd_size_type size;

  char *buf;

  char *p;

  size = (strlen (bfd_get_filename (abfd))

    + strlen (suffix)

    + sizeof "_binary__");

  buf = (char *) bfd_alloc (abfd, size);

  if (buf == NULL)

    return "";

  sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix);

  /* Change any non-alphanumeric characters to underscores.  */

  for (p = buf; *p; p++)

    if (! ISALNUM (*p))

      *p = '_';

  return buf;

}

/* Return the symbol table.  */

static long

binary_canonicalize_symtab (bfd *abfd, asymbol **alocation)

{

  asection *sec = (asection *) abfd->tdata.any;

  asymbol *syms;

  unsigned int i;

  size_t amt = BIN_SYMS * sizeof (asymbol);

  syms = (asymbol *) bfd_alloc (abfd, amt);

  if (syms == NULL)

    return -1;

  /* Start symbol.  */

  syms[0].the_bfd = abfd;

  syms[0].name = mangle_name (abfd, "start");

  syms[0].value = 0;

  syms[0].flags = BSF_GLOBAL;

  syms[0].section = sec;

  syms[0].udata.p = NULL;

  /* End symbol.  */

  syms[1].the_bfd = abfd;

  syms[1].name = mangle_name (abfd, "end");

  syms[1].value = sec->size;

  syms[1].flags = BSF_GLOBAL;

  syms[1].section = sec;

  syms[1].udata.p = NULL;

  /* Size symbol.  */

  syms[2].the_bfd = abfd;

  syms[2].name = mangle_name (abfd, "size");

  syms[2].value = sec->size;

  syms[2].flags = BSF_GLOBAL;

  syms[2].section = bfd_abs_section_ptr;

  syms[2].udata.p = NULL;

  for (i = 0; i < BIN_SYMS; i++)

    *alocation++ = syms++;

  *alocation = NULL;

  return BIN_SYMS;

}

#define binary_make_empty_symbol  _bfd_generic_make_empty_symbol

#define binary_print_symbol       _bfd_nosymbols_print_symbol

#define binary_get_symbol_version_string \

  _bfd_nosymbols_get_symbol_version_string

/* Get information about a symbol.  */

static void

binary_get_symbol_info (bfd *ignore_abfd ATTRIBUTE_UNUSED,

      asymbol *symbol,

      symbol_info *ret)

{

  bfd_symbol_info (symbol, ret);

}

#define binary_bfd_is_local_label_name      bfd_generic_is_local_label_name

#define binary_get_lineno      _bfd_nosymbols_get_lineno

#define binary_find_nearest_line     _bfd_nosymbols_find_nearest_line

#define binary_find_nearest_line_with_alt  _bfd_nosymbols_find_nearest_line_with_alt

#define binary_find_line       _bfd_nosymbols_find_line

#define binary_find_inliner_info     _bfd_nosymbols_find_inliner_info

#define binary_bfd_make_debug_symbol     _bfd_nosymbols_bfd_make_debug_symbol

#define binary_read_minisymbols      _bfd_generic_read_minisymbols

#define binary_minisymbol_to_symbol    _bfd_generic_minisymbol_to_symbol

#define binary_bfd_is_target_special_symbol _bfd_bool_bfd_asymbol_false

/* Set the architecture of a binary file.  */

#define binary_set_arch_mach _bfd_generic_set_arch_mach

/* Write section contents of a binary file.  */

static bool

binary_set_section_contents (bfd *abfd,

           asection *sec,

           const void * data,

           file_ptr offset,

           bfd_size_type size)

{

  if (size == 0)

    return true;

  if (! abfd->output_has_begun)

    {

      bool found_low;

      bfd_vma low;

      asection *s;

      /* The lowest section LMA sets the virtual address of the start

   of the file.  We use this to set the file position of all the

   sections.  */

      found_low = false;

      low = 0;

      for (s = abfd->sections; s != NULL; s = s->next)

  if (((s->flags

        & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD))

       == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC))

      && (s->size > 0)

      && (! found_low || s->lma < low))

    {

      low = s->lma;

      found_low = true;

    }

      for (s = abfd->sections; s != NULL; s = s->next)

  {

    unsigned int opb = bfd_octets_per_byte (abfd, s);

    s->filepos = (s->lma - low) * opb;

    /* Skip following warning check for sections that will not

       occupy file space.  */

    if ((s->flags

         & (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_NEVER_LOAD))

        != (SEC_HAS_CONTENTS | SEC_ALLOC)

        || (s->size == 0))

      continue;

    /* If attempting to generate a binary file from a bfd with

       LMA's all over the place, huge (sparse?) binary files may

       result.  This condition attempts to detect this situation

       and print a warning.  Better heuristics would be nice to

       have.  */

    if (s->filepos < 0)

      _bfd_error_handler

        /* xgettext:c-format */

        (_("warning: writing section `%pA' at huge (ie negative) "

     "file offset"),

         s);

  }

      abfd->output_has_begun = true;

    }

  /* We don't want to output anything for a section that is neither

     loaded nor allocated.  The contents of such a section are not

     meaningful in the binary format.  */

  if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0)

    return true;

  if ((sec->flags & SEC_NEVER_LOAD) != 0)

    return true;

  return _bfd_generic_set_section_contents (abfd, sec, data, offset, size);

}

/* No space is required for header information.  */

static int

binary_sizeof_headers (bfd *abfd ATTRIBUTE_UNUSED,

           struct bfd_link_info *info ATTRIBUTE_UNUSED)

{

  return 0;

}

#define binary_bfd_get_relocated_section_contents  bfd_generic_get_relocated_section_contents

#define binary_bfd_relax_section       bfd_generic_relax_section

#define binary_bfd_gc_sections         bfd_generic_gc_sections

#define binary_bfd_lookup_section_flags      bfd_generic_lookup_section_flags

#define binary_bfd_merge_sections      bfd_generic_merge_sections

#define binary_bfd_is_group_section      bfd_generic_is_group_section

#define binary_bfd_group_name        bfd_generic_group_name

#define binary_bfd_discard_group       bfd_generic_discard_group

#define binary_section_already_linked     _bfd_generic_section_already_linked

#define binary_bfd_define_common_symbol      bfd_generic_define_common_symbol

#define binary_bfd_link_hide_symbol      _bfd_generic_link_hide_symbol

#define binary_bfd_define_start_stop       bfd_generic_define_start_stop

#define binary_bfd_link_hash_table_create   _bfd_generic_link_hash_table_create

#define binary_bfd_link_just_syms     _bfd_generic_link_just_syms

#define binary_bfd_copy_link_hash_symbol_type   _bfd_generic_copy_link_hash_symbol_type

#define binary_bfd_link_add_symbols     _bfd_generic_link_add_symbols

#define binary_bfd_final_link       _bfd_generic_final_link

#define binary_bfd_link_split_section     _bfd_generic_link_split_section

#define binary_get_section_contents_in_window   _bfd_generic_get_section_contents_in_window

#define binary_bfd_link_check_relocs      _bfd_generic_link_check_relocs

const bfd_target binary_vec =

{

  "binary",     /* name */

  bfd_target_unknown_flavour, /* flavour */

  BFD_ENDIAN_UNKNOWN,   /* byteorder */

  BFD_ENDIAN_UNKNOWN,   /* header_byteorder */

  EXEC_P,     /* object_flags */

  (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA

   | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */

  0,        /* symbol_leading_char */

  ' ',        /* ar_pad_char */

  16,       /* ar_max_namelen */

  255,        /* match priority.  */

  TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols.  */

  bfd_getb64, bfd_getb_signed_64, bfd_putb64,

  bfd_getb32, bfd_getb_signed_32, bfd_putb32,

  bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */

  bfd_getb64, bfd_getb_signed_64, bfd_putb64,

  bfd_getb32, bfd_getb_signed_32, bfd_putb32,

  bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */

  {       /* bfd_check_format */

    _bfd_dummy_target,

    binary_object_p,

    _bfd_dummy_target,

    _bfd_dummy_target,

  },

  {       /* bfd_set_format */

    _bfd_bool_bfd_false_error,

    binary_mkobject,

    _bfd_bool_bfd_false_error,

    _bfd_bool_bfd_false_error,

  },

  {       /* bfd_write_contents */

    _bfd_bool_bfd_false_error,

    _bfd_bool_bfd_true,

    _bfd_bool_bfd_false_error,

    _bfd_bool_bfd_false_error,

  },

  BFD_JUMP_TABLE_GENERIC (binary),

  BFD_JUMP_TABLE_COPY (_bfd_generic),

  BFD_JUMP_TABLE_CORE (_bfd_nocore),

  BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),

  BFD_JUMP_TABLE_SYMBOLS (binary),

  BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),

  BFD_JUMP_TABLE_WRITE (binary),

  BFD_JUMP_TABLE_LINK (binary),

  BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),

  NULL,

  NULL

};