/* simple.c -- BFD simple client routines

   Copyright (C) 2002-2025 Free Software Foundation, Inc.

   Contributed by MontaVista Software, Inc.

   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.  */

#include "sysdep.h"

#include "bfd.h"

#include "libbfd.h"

#include "bfdlink.h"

#include "genlink.h"

static void

simple_dummy_add_to_set (struct bfd_link_info * info ATTRIBUTE_UNUSED,

       struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED,

       bfd_reloc_code_real_type reloc ATTRIBUTE_UNUSED,

       bfd *abfd ATTRIBUTE_UNUSED,

       asection *sec ATTRIBUTE_UNUSED,

       bfd_vma value ATTRIBUTE_UNUSED)

{

}

static  void

simple_dummy_constructor (struct bfd_link_info * info ATTRIBUTE_UNUSED,

        bool constructor ATTRIBUTE_UNUSED,

        const char *name ATTRIBUTE_UNUSED,

        bfd *abfd ATTRIBUTE_UNUSED,

        asection *sec ATTRIBUTE_UNUSED,

        bfd_vma value ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_multiple_common (struct bfd_link_info * info ATTRIBUTE_UNUSED,

            struct bfd_link_hash_entry * entry ATTRIBUTE_UNUSED,

            bfd * abfd ATTRIBUTE_UNUSED,

            enum bfd_link_hash_type type ATTRIBUTE_UNUSED,

            bfd_vma size ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_warning (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

          const char *warning ATTRIBUTE_UNUSED,

          const char *symbol ATTRIBUTE_UNUSED,

          bfd *abfd ATTRIBUTE_UNUSED,

          asection *section ATTRIBUTE_UNUSED,

          bfd_vma address ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_undefined_symbol (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

             const char *name ATTRIBUTE_UNUSED,

             bfd *abfd ATTRIBUTE_UNUSED,

             asection *section ATTRIBUTE_UNUSED,

             bfd_vma address ATTRIBUTE_UNUSED,

             bool fatal ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_reloc_overflow (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

           struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED,

           const char *name ATTRIBUTE_UNUSED,

           const char *reloc_name ATTRIBUTE_UNUSED,

           bfd_vma addend ATTRIBUTE_UNUSED,

           bfd *abfd ATTRIBUTE_UNUSED,

           asection *section ATTRIBUTE_UNUSED,

           bfd_vma address ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_reloc_dangerous (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

            const char *message ATTRIBUTE_UNUSED,

            bfd *abfd ATTRIBUTE_UNUSED,

            asection *section ATTRIBUTE_UNUSED,

            bfd_vma address ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_unattached_reloc (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

             const char *name ATTRIBUTE_UNUSED,

             bfd *abfd ATTRIBUTE_UNUSED,

             asection *section ATTRIBUTE_UNUSED,

             bfd_vma address ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_multiple_definition (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,

          struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,

          bfd *nbfd ATTRIBUTE_UNUSED,

          asection *nsec ATTRIBUTE_UNUSED,

          bfd_vma nval ATTRIBUTE_UNUSED)

{

}

static void

simple_dummy_einfo (const char *fmt ATTRIBUTE_UNUSED, ...)

{

}

struct saved_output_info

{

  bfd_vma offset;

  asection *section;

};

struct saved_offsets

{

  unsigned int section_count;

  struct saved_output_info *sections;

};

/* The sections in ABFD may already have output sections and offsets

   set if we are here during linking.

   DWARF-2 specifies offsets into debug sections in many cases and

   bfd_simple_get_relocated_section_contents is called to relocate

   debug info for a single relocatable object file.  So we want

   offsets relative to that object file's sections, not offsets in the

   output file.  For that reason, reset a debug section->output_offset

   to zero.

   If not called during linking then set section->output_section to

   point back to the input section, because output_section must not be

   NULL when calling the relocation routines.

   Save the original output offset and section to restore later.  */

static void

simple_save_output_info (bfd *abfd ATTRIBUTE_UNUSED,

       asection *section,

       void *ptr)

{

  struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr;

  struct saved_output_info *output_info;

  output_info = &saved_offsets->sections[section->index];

  output_info->offset = section->output_offset;

  output_info->section = section->output_section;

  if ((section->flags & SEC_DEBUGGING) != 0

      || section->output_section == NULL)

    {

      section->output_offset = 0;

      section->output_section = section;

    }

}

static void

simple_restore_output_info (bfd *abfd ATTRIBUTE_UNUSED,

          asection *section,

          void *ptr)

{

  struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr;

  struct saved_output_info *output_info;

  if (section->index >= saved_offsets->section_count)

    return;

  output_info = &saved_offsets->sections[section->index];

  section->output_offset = output_info->offset;

  section->output_section = output_info->section;

}

/*

FUNCTION

  bfd_simple_relocate_secton

SYNOPSIS

  bfd_byte *bfd_simple_get_relocated_section_contents

    (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table);

DESCRIPTION

  Returns the relocated contents of section @var{sec}.  The symbols in

  @var{symbol_table} will be used, or the symbols from @var{abfd} if

  @var{symbol_table} is NULL.  The output offsets for debug sections will

  be temporarily reset to 0.  The result will be stored at @var{outbuf}

  or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}.

  Returns @code{NULL} on a fatal error; ignores errors applying

  particular relocations.

*/

bfd_byte *

bfd_simple_get_relocated_section_contents (bfd *abfd,

             asection *sec,

             bfd_byte *outbuf,

             asymbol **symbol_table)

{

  struct bfd_link_info link_info;

  struct bfd_link_order link_order;

  struct bfd_link_callbacks callbacks;

  bfd_byte *contents;

  struct saved_offsets saved_offsets;

  bfd *link_next;

  /* Don't apply relocation on executable and shared library.  See

     PR 4756.  */

  if ((abfd->flags & (HAS_RELOC | EXEC_P | DYNAMIC)) != HAS_RELOC

      || ! (sec->flags & SEC_RELOC))

    {

      if (!bfd_get_full_section_contents (abfd, sec, &outbuf))

  return NULL;

      return outbuf;

    }

  /* In order to use bfd_get_relocated_section_contents, we need

     to forge some data structures that it expects.  */

  /* Fill in the bare minimum number of fields for our purposes.  */

  memset (&link_info, 0, sizeof (link_info));

  link_info.output_bfd = abfd;

  link_info.input_bfds = abfd;

  link_info.input_bfds_tail = &abfd->link.next;

  link_next = abfd->link.next;

  abfd->link.next = NULL;

  link_info.hash = _bfd_generic_link_hash_table_create (abfd);

  link_info.callbacks = &callbacks;

  /* Make sure that any fields not initialised below do not

     result in a potential indirection via a random address.  */

  memset (&callbacks, 0, sizeof callbacks);

  callbacks.warning = simple_dummy_warning;

  callbacks.undefined_symbol = simple_dummy_undefined_symbol;

  callbacks.reloc_overflow = simple_dummy_reloc_overflow;

  callbacks.reloc_dangerous = simple_dummy_reloc_dangerous;

  callbacks.unattached_reloc = simple_dummy_unattached_reloc;

  callbacks.multiple_definition = simple_dummy_multiple_definition;

  callbacks.einfo = simple_dummy_einfo;

  callbacks.multiple_common = simple_dummy_multiple_common;

  callbacks.constructor = simple_dummy_constructor;

  callbacks.add_to_set = simple_dummy_add_to_set;

  memset (&link_order, 0, sizeof (link_order));

  link_order.next = NULL;

  link_order.type = bfd_indirect_link_order;

  link_order.offset = 0;

  link_order.size = sec->size;

  link_order.u.indirect.section = sec;

  contents = NULL;

  saved_offsets.section_count = abfd->section_count;

  saved_offsets.sections = malloc (sizeof (*saved_offsets.sections)

           * saved_offsets.section_count);

  if (saved_offsets.sections == NULL)

    goto out1;

  bfd_map_over_sections (abfd, simple_save_output_info, &saved_offsets);

  if (symbol_table == NULL)

    {

      if (!bfd_generic_link_read_symbols (abfd))

  goto out2;

      symbol_table = _bfd_generic_link_get_symbols (abfd);

    }

  contents = bfd_get_relocated_section_contents (abfd,

             &link_info,

             &link_order,

             outbuf,

             false,

             symbol_table);

 out2:

  bfd_map_over_sections (abfd, simple_restore_output_info, &saved_offsets);

  free (saved_offsets.sections);

 out1:

  _bfd_generic_link_hash_table_free (abfd);

  abfd->link.next = link_next;

  return contents;

}