write.c

基于4个mips核的noc设计

  for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
    {
      arelent *reloc;
      bfd_reloc_status_type s;
      symbolS *sym;

      if (fixp->fx_done)
	{
	  n--;
	  continue;
	}

      /* If this is an undefined symbol which was equated to another
         symbol, then use generate the reloc against the latter symbol
         rather than the former.  */
      sym = fixp->fx_addsy;
      while (symbol_equated_p (sym)
	     && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
	{
	  symbolS *n;

	  /* We must avoid looping, as that can occur with a badly
	     written program.  */
	  n = symbol_get_value_expression (sym)->X_add_symbol;
	  if (n == sym)
	    break;
	  fixp->fx_offset += symbol_get_value_expression (sym)->X_add_number;
	  sym = n;
	}
      fixp->fx_addsy = sym;

      reloc = tc_gen_reloc (sec, fixp);
      if (!reloc)
	{
	  n--;
	  continue;
	}

#if 0
      /* This test is triggered inappropriately for the SH.  */
      if (fixp->fx_where + fixp->fx_size
	  > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset)
	abort ();
#endif

      s = bfd_install_relocation (stdoutput, reloc,
				  fixp->fx_frag->fr_literal,
				  fixp->fx_frag->fr_address,
				  sec, &err);
      switch (s)
	{
	case bfd_reloc_ok:
	  break;
	case bfd_reloc_overflow:
	  as_bad_where (fixp->fx_file, fixp->fx_line, _("relocation overflow"));
	  break;
	case bfd_reloc_outofrange:
	  as_bad_where (fixp->fx_file, fixp->fx_line, _("relocation out of range"));
	  break;
	default:
	  as_fatal (_("%s:%u: bad return from bfd_install_relocation: %x"),
		    fixp->fx_file, fixp->fx_line, s);
	}
      relocs[i++] = reloc;
    }
#else
  n = n * MAX_RELOC_EXPANSION;
  /* Set up reloc information as well.  */
  relocs = (arelent **) xmalloc (n * sizeof (arelent *));

  i = 0;
  for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next)
    {
      arelent **reloc;
      char *data;
      bfd_reloc_status_type s;
      symbolS *sym;
      int j;

      if (fixp->fx_done)
	{
	  n--;
	  continue;
	}

      /* If this is an undefined symbol which was equated to another
         symbol, then generate the reloc against the latter symbol
         rather than the former.  */
      sym = fixp->fx_addsy;
      while (symbol_equated_p (sym)
	     && (! S_IS_DEFINED (sym) || S_IS_COMMON (sym)))
	sym = symbol_get_value_expression (sym)->X_add_symbol;
      fixp->fx_addsy = sym;

      reloc = tc_gen_reloc (sec, fixp);

      for (j = 0; reloc[j]; j++)
	{
	  relocs[i++] = reloc[j];
	  assert (i <= n);
	}
      data = fixp->fx_frag->fr_literal + fixp->fx_where;
      if (fixp->fx_where + fixp->fx_size
	  > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset)
	as_bad_where (fixp->fx_file, fixp->fx_line,
		      _("internal error: fixup not contained within frag"));
      for (j = 0; reloc[j]; j++)
	{
	  s = bfd_install_relocation (stdoutput, reloc[j],
				      fixp->fx_frag->fr_literal,
				      fixp->fx_frag->fr_address,
				      sec, &err);
	  switch (s)
	    {
	    case bfd_reloc_ok:
	      break;
	    case bfd_reloc_overflow:
	      as_bad_where (fixp->fx_file, fixp->fx_line,
			    _("relocation overflow"));
	      break;
	    default:
	      as_fatal (_("%s:%u: bad return from bfd_install_relocation"),
			fixp->fx_file, fixp->fx_line);
	    }
	}
    }
  n = i;
#endif

#ifdef DEBUG4
  {
    int i, j, nsyms;
    asymbol **sympp;
    sympp = bfd_get_outsymbols (stdoutput);
    nsyms = bfd_get_symcount (stdoutput);
    for (i = 0; i < n; i++)
      if (((*relocs[i]->sym_ptr_ptr)->flags & BSF_SECTION_SYM) == 0)
	{
	  for (j = 0; j < nsyms; j++)
	    if (sympp[j] == *relocs[i]->sym_ptr_ptr)
	      break;
	  if (j == nsyms)
	    abort ();
	}
  }
#endif

  if (n)
    bfd_set_reloc (stdoutput, sec, relocs, n);
  else
    bfd_set_section_flags (abfd, sec,
			   (bfd_get_section_flags (abfd, sec)
			    & (flagword) ~SEC_RELOC));

#ifdef SET_SECTION_RELOCS
  SET_SECTION_RELOCS (sec, relocs, n);
#endif

#ifdef DEBUG3
  {
    int i;
    arelent *r;
    asymbol *s;
    fprintf (stderr, "relocs for sec %s\n", sec->name);
    for (i = 0; i < n; i++)
      {
	r = relocs[i];
	s = *r->sym_ptr_ptr;
	fprintf (stderr, "  reloc %2d @%08x off %4x : sym %-10s addend %x\n",
		 i, r, r->address, s->name, r->addend);
      }
  }
#endif
}

static void
write_contents (abfd, sec, xxx)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec;
     PTR xxx ATTRIBUTE_UNUSED;
{
  segment_info_type *seginfo = seg_info (sec);
  unsigned long offset = 0;
  fragS *f;

  /* Write out the frags.  */
  if (seginfo == NULL
      || !(bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS))
    return;

  for (f = seginfo->frchainP->frch_root;
       f;
       f = f->fr_next)
    {
      int x;
      unsigned long fill_size;
      char *fill_literal;
      long count;

      assert (f->fr_type == rs_fill);
      if (f->fr_fix)
	{
	  x = bfd_set_section_contents (stdoutput, sec,
					f->fr_literal, (file_ptr) offset,
					(bfd_size_type) f->fr_fix);
	  if (x == false)
	    {
	      bfd_perror (stdoutput->filename);
	      as_perror (_("FATAL: Can't write %s"), stdoutput->filename);
	      exit (EXIT_FAILURE);
	    }
	  offset += f->fr_fix;
	}
      fill_literal = f->fr_literal + f->fr_fix;
      fill_size = f->fr_var;
      count = f->fr_offset;
      assert (count >= 0);
      if (fill_size && count)
	{
	  char buf[256];
	  if (fill_size > sizeof (buf))
	    {
	      /* Do it the old way. Can this ever happen?  */
	      while (count--)
		{
		  x = bfd_set_section_contents (stdoutput, sec,
						fill_literal,
						(file_ptr) offset,
						(bfd_size_type) fill_size);
		  if (x == false)
		    {
		      bfd_perror (stdoutput->filename);
		      as_perror (_("FATAL: Can't write %s"),
				 stdoutput->filename);
		      exit (EXIT_FAILURE);
		    }
		  offset += fill_size;
		}
	    }
	  else
	    {
	      /* Build a buffer full of fill objects and output it as
		 often as necessary. This saves on the overhead of
		 potentially lots of bfd_set_section_contents calls.  */
	      int n_per_buf, i;
	      if (fill_size == 1)
		{
		  n_per_buf = sizeof (buf);
		  memset (buf, *fill_literal, n_per_buf);
		}
	      else
		{
		  char *bufp;
		  n_per_buf = sizeof (buf) / fill_size;
		  for (i = n_per_buf, bufp = buf; i; i--, bufp += fill_size)
		    memcpy (bufp, fill_literal, fill_size);
		}
	      for (; count > 0; count -= n_per_buf)
		{
		  n_per_buf = n_per_buf > count ? count : n_per_buf;
		  x = bfd_set_section_contents
		    (stdoutput, sec, buf, (file_ptr) offset,
		     (bfd_size_type) n_per_buf * fill_size);
		  if (x != true)
		    as_fatal (_("Cannot write to output file."));
		  offset += n_per_buf * fill_size;
		}
	    }
	}
    }
}
#endif

#if defined(BFD_ASSEMBLER) || (!defined (BFD) && !defined(OBJ_AOUT))
static void
merge_data_into_text ()
{
#if defined(BFD_ASSEMBLER) || defined(MANY_SEGMENTS)
  seg_info (text_section)->frchainP->frch_last->fr_next =
    seg_info (data_section)->frchainP->frch_root;
  seg_info (text_section)->frchainP->frch_last =
    seg_info (data_section)->frchainP->frch_last;
  seg_info (data_section)->frchainP = 0;
#else
  fixS *tmp;

  text_last_frag->fr_next = data_frag_root;
  text_last_frag = data_last_frag;
  data_last_frag = NULL;
  data_frag_root = NULL;
  if (text_fix_root)
    {
      for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next);;
      tmp->fx_next = data_fix_root;
      text_fix_tail = data_fix_tail;
    }
  else
    text_fix_root = data_fix_root;
  data_fix_root = NULL;
#endif
}
#endif /* BFD_ASSEMBLER || (! BFD && ! OBJ_AOUT)  */

#if !defined (BFD_ASSEMBLER) && !defined (BFD)
static void
relax_and_size_all_segments ()
{
  fragS *fragP;

  relax_segment (text_frag_root, SEG_TEXT);
  relax_segment (data_frag_root, SEG_DATA);
  relax_segment (bss_frag_root, SEG_BSS);

  /* Now the addresses of frags are correct within the segment.  */
  know (text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0);
  H_SET_TEXT_SIZE (&headers, text_last_frag->fr_address);
  text_last_frag->fr_address = H_GET_TEXT_SIZE (&headers);

  /* Join the 2 segments into 1 huge segment.
     To do this, re-compute every rn_address in the SEG_DATA frags.
     Then join the data frags after the text frags.

     Determine a_data [length of data segment].  */
  if (data_frag_root)
    {
      register relax_addressT slide;

      know ((text_last_frag->fr_type == rs_fill)
	    && (text_last_frag->fr_offset == 0));

      H_SET_DATA_SIZE (&headers, data_last_frag->fr_address);
      data_last_frag->fr_address = H_GET_DATA_SIZE (&headers);
      slide = H_GET_TEXT_SIZE (&headers);	/* & in file of the data segment.  */
#ifdef OBJ_BOUT
#define RoundUp(N,S) (((N)+(S)-1)&-(S))
      /* For b.out: If the data section has a strict alignment
	 requirement, its load address in the .o file will be
	 rounded up from the size of the text section.  These
	 two values are *not* the same!  Similarly for the bss
	 section....  */
      slide = RoundUp (slide, 1 << section_alignment[SEG_DATA]);
#endif

      for (fragP = data_frag_root; fragP; fragP = fragP->fr_next)
	fragP->fr_address += slide;

      know (text_last_frag != 0);
      text_last_frag->fr_next = data_frag_root;
    }
  else
    {
      H_SET_DATA_SIZE (&headers, 0);
    }

#ifdef OBJ_BOUT
  /* See above comments on b.out data section address.  */
  {
    long bss_vma;
    if (data_last_frag == 0)
      bss_vma = H_GET_TEXT_SIZE (&headers);
    else
      bss_vma = data_last_frag->fr_address;
    bss_vma = RoundUp (bss_vma, 1 << section_alignment[SEG_BSS]);
    bss_address_frag.fr_address = bss_vma;
  }
#else /* ! OBJ_BOUT  */
  bss_address_frag.fr_address = (H_GET_TEXT_SIZE (&headers) +
				 H_GET_DATA_SIZE (&headers));

#endif /* ! OBJ_BOUT  */

  /* Slide all the frags.  */
  if (bss_frag_root)
    {
      relax_addressT slide = bss_address_frag.fr_address;

      for (fragP = bss_frag_root; fragP; fragP = fragP->fr_next)
	fragP->fr_address += slide;
    }

  if (bss_last_frag)
    H_SET_BSS_SIZE (&headers,
		    bss_last_frag->fr_address - bss_frag_root->fr_address);
  else
    H_SET_BSS_SIZE (&headers, 0);
}
#endif /* ! BFD_ASSEMBLER && ! BFD  */

#if defined (BFD_ASSEMBLER) || !defined (BFD)

#ifdef BFD_ASSEMBLER
static void
set_symtab ()
{
  int nsyms;
  asymbol **asympp;
  symbolS *symp;
  boolean result;
  extern PTR bfd_alloc PARAMS ((bfd *, size_t));

  /* Count symbols.  We can't rely on a count made by the loop in
     write_object_file, because *_frob_file may add a new symbol or
     two.  */
  nsyms = 0;
  for (symp = symbol_rootP; symp; symp = symbol_next (symp))
    nsyms++;

  if (nsyms)
    {
      int i;

      asympp = (asymbol **) bfd_alloc (stdoutput,
				       nsyms * sizeof (asymbol *));
      symp = symbol_rootP;
      for (i = 0; i < nsyms; i++, symp = symbol_next (symp))
	{
	  asympp[i] = symbol_get_bfdsym (symp);
	  symbol_mark_written (symp);
	}
    }
  else
    asympp = 0;
  result = bfd_set_symtab (stdoutput, asympp, nsyms);
  assert (result == true);
  symbol_table_frozen = 1;
}
#endif

#if defined (BFD_ASSEMBLER) && defined (OBJ_COFF) && defined (TE_GO32)
static void
set_segment_vma (abfd, sec, xxx)
     bfd *abfd;
     asection *sec;
     PTR xxx ATTRIBUTE_UNUSED;
{
  static bfd_vma addr = 0;

  bfd_set_section_vma (abfd, sec, addr);
  addr += bfd_section_size (abfd, sec);
}
#endif /* BFD_ASSEMBLER && OBJ_COFF && !TE_PE  */

/* Finish the subsegments.  After every sub-segment, we fake an
   ".align ...".  This conforms to BSD4.2 brane-damage.  We then fake
   ".fill 0" because that is the kind of frag that requires least
   thought.  ".align" frags like to have a following frag since that
   makes calculating their intended length trivial.  */

#ifndef SUB_SEGMENT_ALIGN
#ifdef BFD_ASSEMBLER
#define SUB_SEGMENT_ALIGN(SEG) (0)
#else
#define SUB_SEGMENT_ALIGN(SEG) (2)
#endif
#endif

void
subsegs_finish ()
{
  struct frchain *frchainP;

  for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next)
    {
      int alignment;

      subseg_set (frchainP->frch_seg, frchainP->frch_subseg);

      /* This now gets called even if we had errors.  In that case,
         any alignment is meaningless, and, moreover, will look weird
         if we are generating a listing.  */
      alignment = had_errors () ? 0 : SUB_SEGMENT_ALIGN (now_seg);

      /* The last subsegment gets an aligment corresponding to the
	 alignment of the section.  This allows proper nop-filling
	 at the end of code-bearing sections.  */
      if (!frchainP->frch_next || frchainP->frch_next->frch_seg != now_seg)
	alignment = get_recorded_alignment (now_seg);