elf32-sparc.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 2,014 行 · 第 1/5 页

		  && ((y & F3I(~0))
		      || (y & RS2(~0)) != RS2(O7)))
		{
		  bfd_vma reloc;

		  reloc = relocation + rel->r_addend - rel->r_offset;
		  reloc -= (input_section->output_section->vma
			   + input_section->output_offset);

		  /* Ensure the reloc fits into simm22.  */
		  if ((reloc & 3) == 0
		      && ((reloc & ~(bfd_vma)0x7fffff) == 0
			  || ((reloc | 0x7fffff) == ~(bfd_vma)0)))
		    {
		      reloc >>= 2;

		      /* Check whether it fits into simm19 on v9.  */
		      if (((reloc & 0x3c0000) == 0
			   || (reloc & 0x3c0000) == 0x3c0000)
			  && (elf_elfheader (output_bfd)->e_flags & EF_SPARC_32PLUS))
			x = INSN_BPA | (reloc & 0x7ffff); /* ba,pt %xcc */
		      else
			x = INSN_BA | (reloc & 0x3fffff); /* ba */
		      bfd_put_32 (input_bfd, x, contents + rel->r_offset);
		      r = bfd_reloc_ok;
		      if (rel->r_offset >= 4
			  && (y & (0xffffffff ^ RS1(~0)))
			      == (INSN_OR | RD(O7) | RS2(G0)))
			{
			  bfd_vma z;
			  unsigned int reg;

			  z = bfd_get_32 (input_bfd,
					  contents + rel->r_offset - 4);
			  if ((z & (0xffffffff ^ RD(~0)))
			      != (INSN_OR | RS1(O7) | RS2(G0)))
			    break;

			  /* The sequence was
			     or %o7, %g0, %rN
			     call foo
			     or %rN, %g0, %o7

			     If call foo was replaced with ba, replace
			     or %rN, %g0, %o7 with nop.  */

			  reg = (y & RS1(~0)) >> 14;
			  if (reg != ((z & RD(~0)) >> 25)
			      || reg == G0 || reg == O7)
			    break;

			  bfd_put_32 (input_bfd, INSN_NOP,
				      contents + rel->r_offset + 4);
			}

		    }
		}
	    }
	}

      if (r == bfd_reloc_continue)
	r = _bfd_final_link_relocate (howto, input_bfd, input_section,
				      contents, rel->r_offset,
				      relocation, rel->r_addend);

      if (r != bfd_reloc_ok)
	{
	  switch (r)
	    {
	    default:
	    case bfd_reloc_outofrange:
	      abort ();
	    case bfd_reloc_overflow:
	      {
		const char *name;

		if (h != NULL)
		  name = h->root.root.string;
		else
		  {
		    name = bfd_elf_string_from_elf_section (input_bfd,
							    symtab_hdr->sh_link,
							    sym->st_name);
		    if (name == NULL)
		      return false;
		    if (*name == '\0')
		      name = bfd_section_name (input_bfd, sec);
		  }
		if (! ((*info->callbacks->reloc_overflow)
		       (info, name, howto->name, (bfd_vma) 0,
			input_bfd, input_section, rel->r_offset)))
		  return false;
	      }
	      break;
	    }
	}
    }

  return true;
}

/* Finish up dynamic symbol handling.  We set the contents of various
   dynamic sections here.  */

static boolean
elf32_sparc_finish_dynamic_symbol (output_bfd, info, h, sym)
     bfd *output_bfd;
     struct bfd_link_info *info;
     struct elf_link_hash_entry *h;
     Elf_Internal_Sym *sym;
{
  bfd *dynobj;

  dynobj = elf_hash_table (info)->dynobj;

  if (h->plt.offset != (bfd_vma) -1)
    {
      asection *splt;
      asection *srela;
      Elf_Internal_Rela rela;

      /* This symbol has an entry in the procedure linkage table.  Set
         it up.  */

      BFD_ASSERT (h->dynindx != -1);

      splt = bfd_get_section_by_name (dynobj, ".plt");
      srela = bfd_get_section_by_name (dynobj, ".rela.plt");
      BFD_ASSERT (splt != NULL && srela != NULL);

      /* Fill in the entry in the procedure linkage table.  */
      bfd_put_32 (output_bfd,
		  PLT_ENTRY_WORD0 + h->plt.offset,
		  splt->contents + h->plt.offset);
      bfd_put_32 (output_bfd,
		  (PLT_ENTRY_WORD1
		   + (((- (h->plt.offset + 4)) >> 2) & 0x3fffff)),
		  splt->contents + h->plt.offset + 4);
      bfd_put_32 (output_bfd, PLT_ENTRY_WORD2,
		  splt->contents + h->plt.offset + 8);

      /* Fill in the entry in the .rela.plt section.  */
      rela.r_offset = (splt->output_section->vma
		       + splt->output_offset
		       + h->plt.offset);
      rela.r_info = ELF32_R_INFO (h->dynindx, R_SPARC_JMP_SLOT);
      rela.r_addend = 0;
      bfd_elf32_swap_reloca_out (output_bfd, &rela,
				 ((Elf32_External_Rela *) srela->contents
				  + h->plt.offset / PLT_ENTRY_SIZE - 4));

      if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
	{
	  /* Mark the symbol as undefined, rather than as defined in
	     the .plt section.  Leave the value alone.  */
	  sym->st_shndx = SHN_UNDEF;
	  /* If the symbol is weak, we do need to clear the value.
	     Otherwise, the PLT entry would provide a definition for
	     the symbol even if the symbol wasn't defined anywhere,
	     and so the symbol would never be NULL.  */
	  if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK)
	      == 0)
	    sym->st_value = 0;
	}
    }

  if (h->got.offset != (bfd_vma) -1)
    {
      asection *sgot;
      asection *srela;
      Elf_Internal_Rela rela;

      /* This symbol has an entry in the global offset table.  Set it
         up.  */

      sgot = bfd_get_section_by_name (dynobj, ".got");
      srela = bfd_get_section_by_name (dynobj, ".rela.got");
      BFD_ASSERT (sgot != NULL && srela != NULL);

      rela.r_offset = (sgot->output_section->vma
		       + sgot->output_offset
		       + (h->got.offset &~ 1));

      /* If this is a -Bsymbolic link, and the symbol is defined
	 locally, we just want to emit a RELATIVE reloc.  Likewise if
	 the symbol was forced to be local because of a version file.
	 The entry in the global offset table will already have been
	 initialized in the relocate_section function.  */
      if (info->shared
	  && (info->symbolic || h->dynindx == -1)
	  && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
	rela.r_info = ELF32_R_INFO (0, R_SPARC_RELATIVE);
      else
	{
	  bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset);
	  rela.r_info = ELF32_R_INFO (h->dynindx, R_SPARC_GLOB_DAT);
	}

      rela.r_addend = 0;
      bfd_elf32_swap_reloca_out (output_bfd, &rela,
				 ((Elf32_External_Rela *) srela->contents
				  + srela->reloc_count));
      ++srela->reloc_count;
    }

  if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
    {
      asection *s;
      Elf_Internal_Rela rela;

      /* This symbols needs a copy reloc.  Set it up.  */

      BFD_ASSERT (h->dynindx != -1);

      s = bfd_get_section_by_name (h->root.u.def.section->owner,
				   ".rela.bss");
      BFD_ASSERT (s != NULL);

      rela.r_offset = (h->root.u.def.value
		       + h->root.u.def.section->output_section->vma
		       + h->root.u.def.section->output_offset);
      rela.r_info = ELF32_R_INFO (h->dynindx, R_SPARC_COPY);
      rela.r_addend = 0;
      bfd_elf32_swap_reloca_out (output_bfd, &rela,
				 ((Elf32_External_Rela *) s->contents
				  + s->reloc_count));
      ++s->reloc_count;
    }

  /* Mark some specially defined symbols as absolute.  */
  if (strcmp (h->root.root.string, "_DYNAMIC") == 0
      || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0
      || strcmp (h->root.root.string, "_PROCEDURE_LINKAGE_TABLE_") == 0)
    sym->st_shndx = SHN_ABS;

  return true;
}

/* Finish up the dynamic sections.  */

static boolean
elf32_sparc_finish_dynamic_sections (output_bfd, info)
     bfd *output_bfd;
     struct bfd_link_info *info;
{
  bfd *dynobj;
  asection *sdyn;
  asection *sgot;

  dynobj = elf_hash_table (info)->dynobj;

  sdyn = bfd_get_section_by_name (dynobj, ".dynamic");

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      asection *splt;
      Elf32_External_Dyn *dyncon, *dynconend;

      splt = bfd_get_section_by_name (dynobj, ".plt");
      BFD_ASSERT (splt != NULL && sdyn != NULL);

      dyncon = (Elf32_External_Dyn *) sdyn->contents;
      dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
      for (; dyncon < dynconend; dyncon++)
	{
	  Elf_Internal_Dyn dyn;
	  const char *name;
	  boolean size;

	  bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn);

	  switch (dyn.d_tag)
	    {
	    case DT_PLTGOT:   name = ".plt"; size = false; break;
	    case DT_PLTRELSZ: name = ".rela.plt"; size = true; break;
	    case DT_JMPREL:   name = ".rela.plt"; size = false; break;
	    default:	  name = NULL; size = false; break;
	    }

	  if (name != NULL)
	    {
	      asection *s;

	      s = bfd_get_section_by_name (output_bfd, name);
	      if (s == NULL)
		dyn.d_un.d_val = 0;
	      else
		{
		  if (! size)
		    dyn.d_un.d_ptr = s->vma;
		  else
		    {
		      if (s->_cooked_size != 0)
			dyn.d_un.d_val = s->_cooked_size;
		      else
			dyn.d_un.d_val = s->_raw_size;
		    }
		}
	      bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
	    }
	}

      /* Clear the first four entries in the procedure linkage table,
	 and put a nop in the last four bytes.  */
      if (splt->_raw_size > 0)
	{
	  memset (splt->contents, 0, 4 * PLT_ENTRY_SIZE);
	  bfd_put_32 (output_bfd, SPARC_NOP,
		      splt->contents + splt->_raw_size - 4);
	}

      elf_section_data (splt->output_section)->this_hdr.sh_entsize =
	PLT_ENTRY_SIZE;
    }

  /* Set the first entry in the global offset table to the address of
     the dynamic section.  */
  sgot = bfd_get_section_by_name (dynobj, ".got");
  BFD_ASSERT (sgot != NULL);
  if (sgot->_raw_size > 0)
    {
      if (sdyn == NULL)
	bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents);
      else
	bfd_put_32 (output_bfd,
		    sdyn->output_section->vma + sdyn->output_offset,
		    sgot->contents);
    }

  elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;

  return true;
}

/* Functions for dealing with the e_flags field.

   We don't define set_private_flags or copy_private_bfd_data because
   the only currently defined values are based on the bfd mach number,
   so we use the latter instead and defer setting e_flags until the
   file is written out.  */

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

static boolean
elf32_sparc_merge_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  boolean error;
  /* FIXME: This should not be static.  */
  static unsigned long previous_ibfd_e_flags = (unsigned long) -1;

  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return true;

  error = false;

  if (bfd_get_mach (ibfd) >= bfd_mach_sparc_v9)
    {
      error = true;
      (*_bfd_error_handler)
	(_("%s: compiled for a 64 bit system and target is 32 bit"),
	 bfd_get_filename (ibfd));
    }
  else if ((ibfd->flags & DYNAMIC) == 0)
    {
      if (bfd_get_mach (obfd) < bfd_get_mach (ibfd))
	bfd_set_arch_mach (obfd, bfd_arch_sparc, bfd_get_mach (ibfd));
    }

  if (((elf_elfheader (ibfd)->e_flags & EF_SPARC_LEDATA)
       != previous_ibfd_e_flags)
      && previous_ibfd_e_flags != (unsigned long) -1)
    {
      (*_bfd_error_handler)
	(_("%s: linking little endian files with big endian files"),
	 bfd_get_filename (ibfd));
      error = true;
    }
  previous_ibfd_e_flags = elf_elfheader (ibfd)->e_flags & EF_SPARC_LEDATA;

  if (error)
    {
      bfd_set_error (bfd_error_bad_value);
      return false;
    }

  return true;
}

/* Set the right machine number.  */

static boolean
elf32_sparc_object_p (abfd)
     bfd *abfd;
{
  if (elf_elfheader (abfd)->e_machine == EM_SPARC32PLUS)
    {
      if (elf_elfheader (abfd)->e_flags & EF_SPARC_SUN_US3)
	return bfd_def