elf.c

基于4个mips核的noc设计

    }
}

/* Create an entry in an ELF linker hash table.  */

struct bfd_hash_entry *
_bfd_elf_link_hash_newfunc (entry, table, string)
     struct bfd_hash_entry *entry;
     struct bfd_hash_table *table;
     const char *string;
{
  struct elf_link_hash_entry *ret = (struct elf_link_hash_entry *) entry;

  /* Allocate the structure if it has not already been allocated by a
     subclass.  */
  if (ret == (struct elf_link_hash_entry *) NULL)
    ret = ((struct elf_link_hash_entry *)
	   bfd_hash_allocate (table, sizeof (struct elf_link_hash_entry)));
  if (ret == (struct elf_link_hash_entry *) NULL)
    return (struct bfd_hash_entry *) ret;

  /* Call the allocation method of the superclass.  */
  ret = ((struct elf_link_hash_entry *)
	 _bfd_link_hash_newfunc ((struct bfd_hash_entry *) ret,
				 table, string));
  if (ret != (struct elf_link_hash_entry *) NULL)
    {
      /* Set local fields.  */
      ret->indx = -1;
      ret->size = 0;
      ret->dynindx = -1;
      ret->dynstr_index = 0;
      ret->weakdef = NULL;
      ret->got.offset = (bfd_vma) -1;
      ret->plt.offset = (bfd_vma) -1;
      ret->linker_section_pointer = (elf_linker_section_pointers_t *)0;
      ret->verinfo.verdef = NULL;
      ret->vtable_entries_used = NULL;
      ret->vtable_entries_size = 0;
      ret->vtable_parent = NULL;
      ret->type = STT_NOTYPE;
      ret->other = 0;
      /* Assume that we have been called by a non-ELF symbol reader.
         This flag is then reset by the code which reads an ELF input
         file.  This ensures that a symbol created by a non-ELF symbol
         reader will have the flag set correctly.  */
      ret->elf_link_hash_flags = ELF_LINK_NON_ELF;
    }

  return (struct bfd_hash_entry *) ret;
}

/* Copy data from an indirect symbol to its direct symbol, hiding the
   old indirect symbol.  */

void
_bfd_elf_link_hash_copy_indirect (dir, ind)
     struct elf_link_hash_entry *dir, *ind;
{
  /* Copy down any references that we may have already seen to the
     symbol which just became indirect.  */

  dir->elf_link_hash_flags |=
    (ind->elf_link_hash_flags
     & (ELF_LINK_HASH_REF_DYNAMIC
	| ELF_LINK_HASH_REF_REGULAR
	| ELF_LINK_HASH_REF_REGULAR_NONWEAK
	| ELF_LINK_NON_GOT_REF));

  /* Copy over the global and procedure linkage table offset entries.
     These may have been already set up by a check_relocs routine.  */
  if (dir->got.offset == (bfd_vma) -1)
    {
      dir->got.offset = ind->got.offset;
      ind->got.offset = (bfd_vma) -1;
    }
  BFD_ASSERT (ind->got.offset == (bfd_vma) -1);

  if (dir->plt.offset == (bfd_vma) -1)
    {
      dir->plt.offset = ind->plt.offset;
      ind->plt.offset = (bfd_vma) -1;
    }
  BFD_ASSERT (ind->plt.offset == (bfd_vma) -1);

  if (dir->dynindx == -1)
    {
      dir->dynindx = ind->dynindx;
      dir->dynstr_index = ind->dynstr_index;
      ind->dynindx = -1;
      ind->dynstr_index = 0;
    }
  BFD_ASSERT (ind->dynindx == -1);
}

void
_bfd_elf_link_hash_hide_symbol (info, h)
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     struct elf_link_hash_entry *h;
{
  h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT;
  h->plt.offset = (bfd_vma) -1;
  if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
    h->dynindx = -1;
}

/* Initialize an ELF linker hash table.  */

boolean
_bfd_elf_link_hash_table_init (table, abfd, newfunc)
     struct elf_link_hash_table *table;
     bfd *abfd;
     struct bfd_hash_entry *(*newfunc) PARAMS ((struct bfd_hash_entry *,
						struct bfd_hash_table *,
						const char *));
{
  table->dynamic_sections_created = false;
  table->dynobj = NULL;
  /* The first dynamic symbol is a dummy.  */
  table->dynsymcount = 1;
  table->dynstr = NULL;
  table->bucketcount = 0;
  table->needed = NULL;
  table->runpath = NULL;
  table->hgot = NULL;
  table->stab_info = NULL;
  table->dynlocal = NULL;
  return _bfd_link_hash_table_init (&table->root, abfd, newfunc);
}

/* Create an ELF linker hash table.  */

struct bfd_link_hash_table *
_bfd_elf_link_hash_table_create (abfd)
     bfd *abfd;
{
  struct elf_link_hash_table *ret;

  ret = ((struct elf_link_hash_table *)
	 bfd_alloc (abfd, sizeof (struct elf_link_hash_table)));
  if (ret == (struct elf_link_hash_table *) NULL)
    return NULL;

  if (! _bfd_elf_link_hash_table_init (ret, abfd, _bfd_elf_link_hash_newfunc))
    {
      bfd_release (abfd, ret);
      return NULL;
    }

  return &ret->root;
}

/* This is a hook for the ELF emulation code in the generic linker to
   tell the backend linker what file name to use for the DT_NEEDED
   entry for a dynamic object.  The generic linker passes name as an
   empty string to indicate that no DT_NEEDED entry should be made.  */

void
bfd_elf_set_dt_needed_name (abfd, name)
     bfd *abfd;
     const char *name;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
      && bfd_get_format (abfd) == bfd_object)
    elf_dt_name (abfd) = name;
}

void
bfd_elf_set_dt_needed_soname (abfd, name)
     bfd *abfd;
     const char *name;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
      && bfd_get_format (abfd) == bfd_object)
    elf_dt_soname (abfd) = name;
}

/* Get the list of DT_NEEDED entries for a link.  This is a hook for
   the linker ELF emulation code.  */

struct bfd_link_needed_list *
bfd_elf_get_needed_list (abfd, info)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
{
  if (info->hash->creator->flavour != bfd_target_elf_flavour)
    return NULL;
  return elf_hash_table (info)->needed;
}

/* Get the list of DT_RPATH/DT_RUNPATH entries for a link.  This is a
   hook for the linker ELF emulation code.  */

struct bfd_link_needed_list *
bfd_elf_get_runpath_list (abfd, info)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
{
  if (info->hash->creator->flavour != bfd_target_elf_flavour)
    return NULL;
  return elf_hash_table (info)->runpath;
}

/* Get the name actually used for a dynamic object for a link.  This
   is the SONAME entry if there is one.  Otherwise, it is the string
   passed to bfd_elf_set_dt_needed_name, or it is the filename.  */

const char *
bfd_elf_get_dt_soname (abfd)
     bfd *abfd;
{
  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
      && bfd_get_format (abfd) == bfd_object)
    return elf_dt_name (abfd);
  return NULL;
}

/* Get the list of DT_NEEDED entries from a BFD.  This is a hook for
   the ELF linker emulation code.  */

boolean
bfd_elf_get_bfd_needed_list (abfd, pneeded)
     bfd *abfd;
     struct bfd_link_needed_list **pneeded;
{
  asection *s;
  bfd_byte *dynbuf = NULL;
  int elfsec;
  unsigned long link;
  bfd_byte *extdyn, *extdynend;
  size_t extdynsize;
  void (*swap_dyn_in) PARAMS ((bfd *, const PTR, Elf_Internal_Dyn *));

  *pneeded = NULL;

  if (bfd_get_flavour (abfd) != bfd_target_elf_flavour
      || bfd_get_format (abfd) != bfd_object)
    return true;

  s = bfd_get_section_by_name (abfd, ".dynamic");
  if (s == NULL || s->_raw_size == 0)
    return true;

  dynbuf = (bfd_byte *) bfd_malloc (s->_raw_size);
  if (dynbuf == NULL)
    goto error_return;

  if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf, (file_ptr) 0,
				  s->_raw_size))
    goto error_return;

  elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
  if (elfsec == -1)
    goto error_return;

  link = elf_elfsections (abfd)[elfsec]->sh_link;

  extdynsize = get_elf_backend_data (abfd)->s->sizeof_dyn;
  swap_dyn_in = get_elf_backend_data (abfd)->s->swap_dyn_in;

  extdyn = dynbuf;
  extdynend = extdyn + s->_raw_size;
  for (; extdyn < extdynend; extdyn += extdynsize)
    {
      Elf_Internal_Dyn dyn;

      (*swap_dyn_in) (abfd, (PTR) extdyn, &dyn);

      if (dyn.d_tag == DT_NULL)
	break;

      if (dyn.d_tag == DT_NEEDED)
	{
	  const char *string;
	  struct bfd_link_needed_list *l;

	  string = bfd_elf_string_from_elf_section (abfd, link,
						    dyn.d_un.d_val);
	  if (string == NULL)
	    goto error_return;

	  l = (struct bfd_link_needed_list *) bfd_alloc (abfd, sizeof *l);
	  if (l == NULL)
	    goto error_return;

	  l->by = abfd;
	  l->name = string;
	  l->next = *pneeded;
	  *pneeded = l;
	}
    }

  free (dynbuf);

  return true;

 error_return:
  if (dynbuf != NULL)
    free (dynbuf);
  return false;
}

/* Allocate an ELF string table--force the first byte to be zero.  */

struct bfd_strtab_hash *
_bfd_elf_stringtab_init ()
{
  struct bfd_strtab_hash *ret;

  ret = _bfd_stringtab_init ();
  if (ret != NULL)
    {
      bfd_size_type loc;

      loc = _bfd_stringtab_add (ret, "", true, false);
      BFD_ASSERT (loc == 0 || loc == (bfd_size_type) -1);
      if (loc == (bfd_size_type) -1)
	{
	  _bfd_stringtab_free (ret);
	  ret = NULL;
	}
    }
  return ret;
}

/* ELF .o/exec file reading */

/* Create a new bfd section from an ELF section header.  */

boolean
bfd_section_from_shdr (abfd, shindex)
     bfd *abfd;
     unsigned int shindex;
{
  Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[shindex];
  Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd);
  struct elf_backend_data *bed = get_elf_backend_data (abfd);
  char *name;

  name = elf_string_from_elf_strtab (abfd, hdr->sh_name);

  switch (hdr->sh_type)
    {
    case SHT_NULL:
      /* Inactive section. Throw it away.  */
      return true;

    case SHT_PROGBITS:	/* Normal section with contents.  */
    case SHT_DYNAMIC:	/* Dynamic linking information.  */
    case SHT_NOBITS:	/* .bss section.  */
    case SHT_HASH:	/* .hash section.  */
    case SHT_NOTE:	/* .note section.  */
      return _bfd_elf_make_section_from_shdr (abfd, hdr, name);

    case SHT_SYMTAB:		/* A symbol table */
      if (elf_onesymtab (abfd) == shindex)
	return true;

      BFD_ASSERT (hdr->sh_entsize == bed->s->sizeof_sym);
      BFD_ASSERT (elf_onesymtab (abfd) == 0);
      elf_onesymtab (abfd) = shindex;
      elf_tdata (abfd)->symtab_hdr = *hdr;
      elf_elfsections (abfd)[shindex] = hdr = &elf_tdata (abfd)->symtab_hdr;
      abfd->flags |= HAS_SYMS;

      /* Sometimes a shared object will map in the symbol table.  If
         SHF_ALLOC is set, and this is a shared object, then we also
         treat this section as a BFD section.  We can not base the
         decision purely on SHF_ALLOC, because that flag is sometimes
         set in a relocateable object file, which would confuse the
         linker.  */
      if ((hdr->sh_flags & SHF_ALLOC) != 0
	  && (abfd->flags & DYNAMIC) != 0
	  && ! _bfd_elf_make_section_from_shdr (abfd, hdr, name))
	return false;

      return true;

    case SHT_DYNSYM:		/* A dynamic symbol table */
      if (elf_dynsymtab (abfd) == shindex)
	return true;

      BFD_ASSERT (hdr->sh_entsize == bed->s->sizeof_sym);
      BFD_ASSERT (elf_dynsymtab (abfd) == 0);
      elf_dynsymtab (abfd) = shindex;
      elf_tdata (abfd)->dynsymtab_hdr = *hdr;
      elf_elfsections (abfd)[shindex] = hdr = &elf_tdata (abfd)->dynsymtab_hdr;
      abfd->flags |= HAS_SYMS;

      /* Besides being a symbol table, we also treat this as a regular
	 section, so that objcopy can handle it.  */
      return _bfd_elf_make_section_from_shdr (abfd, hdr, name);

    case SHT_STRTAB:		/* A string table */
      if (hdr->bfd_section != NULL)
	return true;
      if (ehdr->e_shstrndx == shindex)
	{
	  elf_tdata (abfd)->shstrtab_hdr = *hdr;
	  elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->shstrtab_hdr;
	  return true;
	}
      {
	unsigned int i;

	for (i = 1; i < ehdr->e_shnum; i++)
	  {
	    Elf_Internal_Shdr *hdr2 = elf_elfsections (abfd)[i];
	    if (hdr2->sh_link == shindex)
	      {
		if (! bfd_section_from_shdr (abfd, i))
		  return false;
		if (elf_onesymtab (abfd) == i)
		  {
		    elf_tdata (abfd)->strtab_hdr = *hdr;
		    elf_elfsections (abfd)[shindex] =
		      &elf_tdata (abfd)->strtab_hdr;
		    return true;
		  }
		if (elf_dynsymtab (abfd) == i)
		  {
		    elf_tdata (abfd)->dynstrtab_hdr = *hdr;
		    elf_elfsections (abfd)[shindex] = hdr =
		      &elf_tdata (abfd)->dynstrtab_hdr;
		    /* We also treat this as a regular section, so
		       that objcopy can handle it.  */
		    break;
		  }
#if 0 /* Not handling other string tables specially right now.  */
		hdr2 = elf_elfsections (abfd)[i];	/* in case it moved */
		/* We have a strtab for some random other section.  */
		newsect = (asection *) hdr2->bfd_section;
		if (!newsect)
		  break;
		hdr->bfd_section = newsect;
		hdr2 = &elf_section_data (newsect)->str_hdr;
		*hdr2 = *hdr;
		elf_elfsections (abfd)[shindex] = hdr2;
#endif
	      }
	  }
      }

      return _bfd_elf_make_section_from_shdr (abfd, hdr, name);

    case SHT_REL:
    case SHT_RELA:
      /* *These* do a lot of work -- but build no sections!  */
      {
	asection *target_sect;
	Elf_Internal_Shdr *hdr2;

	/* Check for a bogus link to avoid crashing.  */
	if (hdr->sh_link >= ehdr->e_shnum)