/* Motorola MCore specific support for 32-bit ELF

   Copyright (C) 1994-2025 Free Software Foundation, 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.  */

/* This file is based on a preliminary RCE ELF ABI.  The

   information may not match the final RCE ELF ABI.   */

#include "sysdep.h"

#include "bfd.h"

#include "bfdlink.h"

#include "libbfd.h"

#include "elf-bfd.h"

#include "elf/mcore.h"

#include <assert.h>

/* RELA relocs are used here...  */

/* Function to set whether a module needs the -mrelocatable bit set.  */

static bool

mcore_elf_set_private_flags (bfd * abfd, flagword flags)

{

  BFD_ASSERT (! elf_flags_init (abfd)

        || elf_elfheader (abfd)->e_flags == flags);

  elf_elfheader (abfd)->e_flags = flags;

  elf_flags_init (abfd) = true;

  return true;

}

/* Merge backend specific data from an object file to the output

   object file when linking.  */

static bool

mcore_elf_merge_private_bfd_data (bfd *ibfd, struct bfd_link_info *info)

{

  bfd *obfd = info->output_bfd;

  flagword old_flags;

  flagword new_flags;

  /* Check if we have the same endianness.  */

  if (! _bfd_generic_verify_endian_match (ibfd, info))

    return false;

  if (   bfd_get_flavour (ibfd) != bfd_target_elf_flavour

      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)

    return true;

  new_flags = elf_elfheader (ibfd)->e_flags;

  old_flags = elf_elfheader (obfd)->e_flags;

  if (! elf_flags_init (obfd))

    {

      /* First call, no flags set.  */

      elf_flags_init (obfd) = true;

      elf_elfheader (obfd)->e_flags = new_flags;

    }

  else if (new_flags == old_flags)

    /* Compatible flags are OK.  */

    ;

  else

    {

      /* FIXME */

    }

  return true;

}

/* Don't pretend we can deal with unsupported relocs.  */

static bfd_reloc_status_type

mcore_elf_unsupported_reloc (bfd * abfd,

           arelent * reloc_entry,

           asymbol * symbol ATTRIBUTE_UNUSED,

           void * data ATTRIBUTE_UNUSED,

           asection * input_section ATTRIBUTE_UNUSED,

           bfd * output_bfd ATTRIBUTE_UNUSED,

           char ** error_message ATTRIBUTE_UNUSED)

{

  BFD_ASSERT (reloc_entry->howto != (reloc_howto_type *)0);

  /* xgettext:c-format */

  _bfd_error_handler (_("%pB: %s unsupported"),

          abfd,

          reloc_entry->howto->name);

  return bfd_reloc_notsupported;

}

static reloc_howto_type * mcore_elf_howto_table [(int) R_MCORE_max];

static reloc_howto_type mcore_elf_howto_raw[] =

{

  /* This reloc does nothing.  */

  HOWTO (R_MCORE_NONE,    /* type */

   0,     /* rightshift */

   0,     /* size */

   0,     /* bitsize */

   false,     /* pc_relative */

   0,     /* bitpos */

   complain_overflow_dont,  /* complain_on_overflow */

   NULL,      /* special_function */

   "R_MCORE_NONE",  /* name */

   false,     /* partial_inplace */

   0,     /* src_mask */

   0,     /* dst_mask */

   false),    /* pcrel_offset */

  /* A standard 32 bit relocation.  */

  HOWTO (R_MCORE_ADDR32,  /* type */

   0,     /* rightshift */

   4,     /* size */

   32,      /* bitsize */

   false,     /* pc_relative */

   0,     /* bitpos */

   complain_overflow_bitfield, /* complain_on_overflow */

   bfd_elf_generic_reloc, /* special_function */

   "ADDR32",    /* name *//* For compatibility with coff/pe port.  */

   false,     /* partial_inplace */

   0x0,     /* src_mask */

   0xffffffff,    /* dst_mask */

   false),    /* pcrel_offset */

  /* 8 bits + 2 zero bits; jmpi/jsri/lrw instructions.

     Should not appear in object files.  */

  HOWTO (R_MCORE_PCRELIMM8BY4,  /* type */

   2,     /* rightshift */

   2,     /* size */

   8,     /* bitsize */

   true,      /* pc_relative */

   0,     /* bitpos */

   complain_overflow_bitfield, /* complain_on_overflow */

   mcore_elf_unsupported_reloc, /* special_function */

   "R_MCORE_PCRELIMM8BY4",/* name */

   false,     /* partial_inplace */

   0,     /* src_mask */

   0,     /* dst_mask */

   true),     /* pcrel_offset */

  /* bsr/bt/bf/br instructions; 11 bits + 1 zero bit

     Span 2k instructions == 4k bytes.

     Only useful pieces at the relocated address are the opcode (5 bits) */

  HOWTO (R_MCORE_PCRELIMM11BY2,/* type */

   1,     /* rightshift */

   2,     /* size */

   11,      /* bitsize */

   true,      /* pc_relative */

   0,     /* bitpos */

   complain_overflow_signed, /* complain_on_overflow */

   bfd_elf_generic_reloc, /* special_function */

   "R_MCORE_PCRELIMM11BY2",/* name */

   false,     /* partial_inplace */

   0x0,     /* src_mask */

   0x7ff,     /* dst_mask */

   true),     /* pcrel_offset */

  /* 4 bits + 1 zero bit; 'loopt' instruction only; unsupported.  */

  HOWTO (R_MCORE_PCRELIMM4BY2,  /* type */

   1,     /* rightshift */

   2,     /* size */

   4,     /* bitsize */

   true,      /* pc_relative */

   0,     /* bitpos */

   complain_overflow_bitfield, /* complain_on_overflow */

   mcore_elf_unsupported_reloc,/* special_function */

   "R_MCORE_PCRELIMM4BY2",/* name */

   false,     /* partial_inplace */

   0,     /* src_mask */

   0,     /* dst_mask */

   true),     /* pcrel_offset */

  /* 32-bit pc-relative. Eventually this will help support PIC code.  */

  HOWTO (R_MCORE_PCREL32, /* type */

   0,     /* rightshift */

   4,     /* size */

   32,      /* bitsize */

   true,      /* pc_relative */

   0,     /* bitpos */

   complain_overflow_bitfield, /* complain_on_overflow */

   bfd_elf_generic_reloc, /* special_function */

   "R_MCORE_PCREL32", /* name */

   false,     /* partial_inplace */

   0x0,     /* src_mask */

   0xffffffff,    /* dst_mask */

   true),     /* pcrel_offset */

  /* Like PCRELIMM11BY2, this relocation indicates that there is a

     'jsri' at the specified address. There is a separate relocation

     entry for the literal pool entry that it references, but we

     might be able to change the jsri to a bsr if the target turns out

     to be close enough [even though we won't reclaim the literal pool

     entry, we'll get some runtime efficiency back]. Note that this

     is a relocation that we are allowed to safely ignore.  */

  HOWTO (R_MCORE_PCRELJSR_IMM11BY2,/* type */

   1,     /* rightshift */

   2,     /* size */

   11,      /* bitsize */

   true,      /* pc_relative */

   0,     /* bitpos */

   complain_overflow_signed, /* complain_on_overflow */

   bfd_elf_generic_reloc, /* special_function */

   "R_MCORE_PCRELJSR_IMM11BY2", /* name */

   false,     /* partial_inplace */

   0x0,     /* src_mask */

   0x7ff,     /* dst_mask */

   true),     /* pcrel_offset */

  /* GNU extension to record C++ vtable hierarchy.  */

  HOWTO (R_MCORE_GNU_VTINHERIT, /* type */

   0,     /* rightshift */

   4,     /* size */

   0,     /* bitsize */

   false,     /* pc_relative */

   0,     /* bitpos */

   complain_overflow_dont, /* complain_on_overflow */

   NULL,      /* special_function */

   "R_MCORE_GNU_VTINHERIT", /* name */

   false,     /* partial_inplace */

   0,     /* src_mask */

   0,     /* dst_mask */

   false),    /* pcrel_offset */

  /* GNU extension to record C++ vtable member usage.  */

  HOWTO (R_MCORE_GNU_VTENTRY, /* type */

   0,     /* rightshift */

   4,     /* size */

   0,     /* bitsize */

   false,     /* pc_relative */

   0,     /* bitpos */

   complain_overflow_dont,/* complain_on_overflow */

   _bfd_elf_rel_vtable_reloc_fn,  /* special_function */

   "R_MCORE_GNU_VTENTRY", /* name */

   false,     /* partial_inplace */

   0,     /* src_mask */

   0,     /* dst_mask */

   false),    /* pcrel_offset */

  HOWTO (R_MCORE_RELATIVE,  /* type */

   0,     /* rightshift */

   4,     /* size */

   32,      /* bitsize */

   false,     /* pc_relative */

   0,     /* bitpos */

   complain_overflow_signed, /* complain_on_overflow */

   NULL,      /* special_function */

   "R_MCORE_RELATIVE",  /* name */

   true,      /* partial_inplace */

   0xffffffff,    /* src_mask */

   0xffffffff,    /* dst_mask */

   false)     /* pcrel_offset */

};

#ifndef NUM_ELEM

#define NUM_ELEM(a) (sizeof (a) / sizeof (a)[0])

#endif

/* Initialize the mcore_elf_howto_table, so that linear accesses can be done.  */

static void

mcore_elf_howto_init (void)

{

  unsigned int i;

  for (i = NUM_ELEM (mcore_elf_howto_raw); i--;)

    {

      unsigned int type;

      type = mcore_elf_howto_raw[i].type;

      BFD_ASSERT (type < NUM_ELEM (mcore_elf_howto_table));

      mcore_elf_howto_table [type] = & mcore_elf_howto_raw [i];

    }

}

static reloc_howto_type *

mcore_elf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,

           bfd_reloc_code_real_type code)

{

  enum elf_mcore_reloc_type mcore_reloc = R_MCORE_NONE;

  switch (code)

    {

    case BFD_RELOC_NONE:         mcore_reloc = R_MCORE_NONE; break;

    case BFD_RELOC_32:           mcore_reloc = R_MCORE_ADDR32; break;

    case BFD_RELOC_MCORE_PCREL_IMM8BY4:      mcore_reloc = R_MCORE_PCRELIMM8BY4; break;

    case BFD_RELOC_MCORE_PCREL_IMM11BY2:     mcore_reloc = R_MCORE_PCRELIMM11BY2; break;

    case BFD_RELOC_MCORE_PCREL_IMM4BY2:      mcore_reloc = R_MCORE_PCRELIMM4BY2; break;

    case BFD_RELOC_32_PCREL:         mcore_reloc = R_MCORE_PCREL32; break;

    case BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2: mcore_reloc = R_MCORE_PCRELJSR_IMM11BY2; break;

    case BFD_RELOC_VTABLE_INHERIT:       mcore_reloc = R_MCORE_GNU_VTINHERIT; break;

    case BFD_RELOC_VTABLE_ENTRY:       mcore_reloc = R_MCORE_GNU_VTENTRY; break;

    case BFD_RELOC_RVA:          mcore_reloc = R_MCORE_RELATIVE; break;

    default:

      return NULL;

    }

  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])

    /* Initialize howto table if needed.  */

    mcore_elf_howto_init ();

  return mcore_elf_howto_table [(int) mcore_reloc];

};

static reloc_howto_type *

mcore_elf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,

           const char *r_name)

{

  unsigned int i;

  for (i = 0;

       i < sizeof (mcore_elf_howto_raw) / sizeof (mcore_elf_howto_raw[0]);

       i++)

    if (mcore_elf_howto_raw[i].name != NULL

  && strcasecmp (mcore_elf_howto_raw[i].name, r_name) == 0)

      return &mcore_elf_howto_raw[i];

  return NULL;

}

/* Set the howto pointer for a RCE ELF reloc.  */

static bool

mcore_elf_info_to_howto (bfd * abfd,

       arelent * cache_ptr,

       Elf_Internal_Rela * dst)

{

  unsigned int r_type;

  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])

    /* Initialize howto table if needed.  */

    mcore_elf_howto_init ();

  r_type = ELF32_R_TYPE (dst->r_info);

  if (r_type >= R_MCORE_max)

    {

      /* xgettext:c-format */

      _bfd_error_handler (_("%pB: unsupported relocation type %#x"),

        abfd, r_type);

      bfd_set_error (bfd_error_bad_value);

      return false;

    }

  cache_ptr->howto = mcore_elf_howto_table [r_type];

  return true;

}

/* The RELOCATE_SECTION function is called by the ELF backend linker

   to handle the relocations for a section.

   The relocs are always passed as Rela structures; if the section

   actually uses Rel structures, the r_addend field will always be

   zero.

   This function is responsible for adjust the section contents as

   necessary, and (if using Rela relocs and generating a

   relocatable output file) adjusting the reloc addend as

   necessary.

   This function does not have to worry about setting the reloc

   address or the reloc symbol index.

   LOCAL_SYMS is a pointer to the swapped in local symbols.

   LOCAL_SECTIONS is an array giving the section in the input file

   corresponding to the st_shndx field of each local symbol.

   The global hash table entry for the global symbols can be found

   via elf_sym_hashes (input_bfd).

   When generating relocatable output, this function must handle

   STB_LOCAL/STT_SECTION symbols specially.  The output symbol is

   going to be the section symbol corresponding to the output

   section, which means that the addend must be adjusted

   accordingly.  */

static int

mcore_elf_relocate_section (bfd * output_bfd,

          struct bfd_link_info * info,

          bfd * input_bfd,

          asection * input_section,

          bfd_byte * contents,

          Elf_Internal_Rela * relocs,

          Elf_Internal_Sym * local_syms,

          asection ** local_sections)

{

  Elf_Internal_Shdr * symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;

  struct elf_link_hash_entry ** sym_hashes = elf_sym_hashes (input_bfd);

  Elf_Internal_Rela * rel = relocs;

  Elf_Internal_Rela * relend = relocs + input_section->reloc_count;

  bool ret = true;

#ifdef DEBUG

  _bfd_error_handler

    ("mcore_elf_relocate_section called for %pB section %pA, %u relocations%s",

     input_bfd,

     input_section,

     input_section->reloc_count,

     (bfd_link_relocatable (info)) ? " (relocatable)" : "");

#endif

  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4]) /* Initialize howto table if needed */

    mcore_elf_howto_init ();

  for (; rel < relend; rel++)

    {

      enum elf_mcore_reloc_type    r_type = (enum elf_mcore_reloc_type) ELF32_R_TYPE (rel->r_info);

      bfd_vma        offset = rel->r_offset;

      bfd_vma        addend = rel->r_addend;

      bfd_reloc_status_type    r = bfd_reloc_other;

      asection *       sec = NULL;

      reloc_howto_type *     howto;

      bfd_vma        relocation;

      Elf_Internal_Sym *     sym = NULL;

      unsigned long      r_symndx;

      struct elf_link_hash_entry * h = NULL;

      unsigned short       oldinst = 0;

      /* Unknown relocation handling.  */

      if ((unsigned) r_type >= (unsigned) R_MCORE_max

    || ! mcore_elf_howto_table [(int)r_type])

  {

    /* xgettext:c-format */

    _bfd_error_handler (_("%pB: unsupported relocation type %#x"),

            input_bfd, (int) r_type);

    bfd_set_error (bfd_error_bad_value);

    ret = false;

    continue;

  }

      howto = mcore_elf_howto_table [(int) r_type];

      r_symndx = ELF32_R_SYM (rel->r_info);

      /* Complain about known relocation that are not yet supported.  */

      if (howto->special_function == mcore_elf_unsupported_reloc)

  {

    /* xgettext:c-format */

    _bfd_error_handler (_("%pB: %s unsupported"),

            input_bfd,

            howto->name);

    bfd_set_error (bfd_error_bad_value);

    ret = false;

    continue;

  }

      if (r_symndx < symtab_hdr->sh_info)

  {

    sym = local_syms + r_symndx;

    sec = local_sections [r_symndx];

    relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);

    addend = rel->r_addend;

  }

      else

  {

    bool unresolved_reloc, warned, ignored;

    RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,

           r_symndx, symtab_hdr, sym_hashes,

           h, sec, relocation,

           unresolved_reloc, warned, ignored);

  }

      if (sec != NULL && discarded_section (sec))

  RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,

           rel, 1, relend, howto, 0, contents);

      if (bfd_link_relocatable (info))

  continue;

      switch (r_type)

  {

  default:

    break;

  case R_MCORE_PCRELJSR_IMM11BY2:

    oldinst = bfd_get_16 (input_bfd, contents + offset);

#define MCORE_INST_BSR  0xF800

    bfd_put_16 (input_bfd, (bfd_vma) MCORE_INST_BSR, contents + offset);

    break;

  }

#ifdef DEBUG

      fprintf (stderr, "\ttype = %s (%d), symbol index = %ld, offset = %ld, addend = %ld\n",

         howto->name, r_type, r_symndx, (long) offset, (long) addend);

#endif

      r = _bfd_final_link_relocate

  (howto, input_bfd, input_section, contents, offset, relocation, addend);

      if (r != bfd_reloc_ok && r_type == R_MCORE_PCRELJSR_IMM11BY2)

  {

    /* Wasn't ok, back it out and give up.  */

    bfd_put_16 (input_bfd, (bfd_vma) oldinst, contents + offset);

    r = bfd_reloc_ok;

  }

      if (r != bfd_reloc_ok)

  {

    ret = false;

    switch (r)

      {

      default:

        break;

      case bfd_reloc_overflow:

        {

    const char * name;

    if (h != NULL)

      name = NULL;

    else

      {

        name = bfd_elf_string_from_elf_section

          (input_bfd, symtab_hdr->sh_link, sym->st_name);

        if (name == NULL)

          break;

        if (* name == '\0')

          name = bfd_section_name (sec);

      }

    (*info->callbacks->reloc_overflow)

      (info, (h ? &h->root : NULL), name, howto->name,

       (bfd_vma) 0, input_bfd, input_section, offset);

        }

        break;

      }

  }

    }

#ifdef DEBUG

  fprintf (stderr, "\n");

#endif

  return ret;

}

/* Return the section that should be marked against GC for a given

   relocation.  */

static asection *

mcore_elf_gc_mark_hook (asection *sec,

      struct bfd_link_info *info,

      Elf_Internal_Rela *rel,

      struct elf_link_hash_entry *h,

      Elf_Internal_Sym *sym)

{

  if (h != NULL)

    switch (ELF32_R_TYPE (rel->r_info))

      {

      case R_MCORE_GNU_VTINHERIT:

      case R_MCORE_GNU_VTENTRY:

  return NULL;

      }

  return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);

}

/* Look through the relocs for a section during the first phase.

   Since we don't do .gots or .plts, we just need to consider the

   virtual table relocs for gc.  */

static bool

mcore_elf_check_relocs (bfd * abfd,

      struct bfd_link_info * info,

      asection * sec,

      const Elf_Internal_Rela * relocs)

{

  Elf_Internal_Shdr * symtab_hdr;

  struct elf_link_hash_entry ** sym_hashes;

  const Elf_Internal_Rela * rel;

  const Elf_Internal_Rela * rel_end;

  if (bfd_link_relocatable (info))

    return true;

  symtab_hdr = & elf_tdata (abfd)->symtab_hdr;

  sym_hashes = elf_sym_hashes (abfd);

  rel_end = relocs + sec->reloc_count;

  for (rel = relocs; rel < rel_end; rel++)

    {

      struct elf_link_hash_entry * h;

      unsigned long r_symndx;

      r_symndx = ELF32_R_SYM (rel->r_info);

      if (r_symndx < symtab_hdr->sh_info)

  h = NULL;

      else

  {

    h = sym_hashes [r_symndx - symtab_hdr->sh_info];

    while (h->root.type == bfd_link_hash_indirect

     || h->root.type == bfd_link_hash_warning)

      h = (struct elf_link_hash_entry *) h->root.u.i.link;

  }

      switch (ELF32_R_TYPE (rel->r_info))

  {

  /* This relocation describes the C++ object vtable hierarchy.

     Reconstruct it for later use during GC.  */

  case R_MCORE_GNU_VTINHERIT:

    if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))

      return false;

    break;

  /* This relocation describes which C++ vtable entries are actually

     used.  Record for later use during GC.  */

  case R_MCORE_GNU_VTENTRY:

    if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))

      return false;

    break;

  }

    }

  return true;

}

static const struct bfd_elf_special_section mcore_elf_special_sections[]=

{

  { STRING_COMMA_LEN (".ctors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },

  { STRING_COMMA_LEN (".dtors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },

  { NULL,         0,  0, 0,      0 }

};

#define TARGET_BIG_SYM    mcore_elf32_be_vec

#define TARGET_BIG_NAME   "elf32-mcore-big"

#define TARGET_LITTLE_SYM mcore_elf32_le_vec

#define TARGET_LITTLE_NAME  "elf32-mcore-little"

#define ELF_ARCH    bfd_arch_mcore

#define ELF_MACHINE_CODE  EM_MCORE

#define ELF_MAXPAGESIZE   0x1000    /* 4k, if we ever have 'em */

#define elf_info_to_howto mcore_elf_info_to_howto

#define elf_info_to_howto_rel NULL

#define bfd_elf32_bfd_merge_private_bfd_data  mcore_elf_merge_private_bfd_data

#define bfd_elf32_bfd_set_private_flags   mcore_elf_set_private_flags

#define bfd_elf32_bfd_reloc_type_lookup   mcore_elf_reloc_type_lookup

#define bfd_elf32_bfd_reloc_name_lookup mcore_elf_reloc_name_lookup

#define elf_backend_relocate_section    mcore_elf_relocate_section

#define elf_backend_gc_mark_hook    mcore_elf_gc_mark_hook

#define elf_backend_check_relocs    mcore_elf_check_relocs

#define elf_backend_special_sections    mcore_elf_special_sections

#define elf_backend_can_gc_sections   1

#define elf_backend_rela_normal     1

#include "elf32-target.h"