[deliverable/binutils-gdb.git] / gas / write.c

/* write.c - emit .o file
   Copyright (C) 1986, 1987, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS 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 2, or (at your option)
   any later version.

   GAS 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 GAS; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* This thing should be set up to do byteordering correctly.  But... */

#include "as.h"
#include "subsegs.h"
#include "obstack.h"
#include "output-file.h"

/* The NOP_OPCODE is for the alignment fill value.  Fill it with a nop
   instruction so that the disassembler does not choke on it.  */
#ifndef NOP_OPCODE
#define NOP_OPCODE 0x00
#endif

#ifndef WORKING_DOT_WORD
extern CONST int md_short_jump_size;
extern CONST int md_long_jump_size;
#endif

#ifndef BFD_ASSEMBLER

#ifndef MANY_SEGMENTS
struct frag *text_frag_root;
struct frag *data_frag_root;
struct frag *bss_frag_root;

struct frag *text_last_frag;	/* Last frag in segment. */
struct frag *data_last_frag;	/* Last frag in segment. */
static struct frag *bss_last_frag;	/* Last frag in segment. */
#endif

#if ! defined (BFD_ASSEMBLER) && ! defined (BFD)
static object_headers headers;
static char *the_object_file;
#endif

long string_byte_count;
char *next_object_file_charP;	/* Tracks object file bytes. */

#ifndef OBJ_VMS
int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE;
#endif

#endif /* BFD_ASSEMBLER */

#ifdef BFD_ASSEMBLER
static fixS *fix_new_internal PARAMS ((fragS *, int where, int size,
				       symbolS *add, symbolS *sub,
				       offsetT offset, int pcrel,
				       bfd_reloc_code_real_type r_type));
#else
static fixS *fix_new_internal PARAMS ((fragS *, int where, int size,
				       symbolS *add, symbolS *sub,
				       offsetT offset, int pcrel,
				       int r_type));
#endif
#if defined (BFD_ASSEMBLER) || !defined (BFD)
static long fixup_segment PARAMS ((fixS * fixP, segT this_segment_type));
#endif
static relax_addressT relax_align PARAMS ((relax_addressT addr, int align));

/*
 *			fix_new()
 *
 * Create a fixS in obstack 'notes'.
 */
static fixS *
fix_new_internal (frag, where, size, add_symbol, sub_symbol, offset, pcrel,
		  r_type)
     fragS *frag;		/* Which frag? */
     int where;			/* Where in that frag? */
     int size;			/* 1, 2, or 4 usually. */
     symbolS *add_symbol;	/* X_add_symbol. */
     symbolS *sub_symbol;	/* X_op_symbol. */
     offsetT offset;		/* X_add_number. */
     int pcrel;			/* TRUE if PC-relative relocation. */
#ifdef BFD_ASSEMBLER
     bfd_reloc_code_real_type r_type; /* Relocation type */
#else
     int r_type;		/* Relocation type */
#endif
{
  fixS *fixP;

  fixP = (fixS *) obstack_alloc (&notes, sizeof (fixS));

  fixP->fx_frag = frag;
  fixP->fx_where = where;
  fixP->fx_size = size;
  fixP->fx_addsy = add_symbol;
  fixP->fx_subsy = sub_symbol;
  fixP->fx_offset = offset;
  fixP->fx_pcrel = pcrel;
#if defined(NEED_FX_R_TYPE) || defined (BFD_ASSEMBLER)
  fixP->fx_r_type = r_type;
#endif
  fixP->fx_im_disp = 0;
  fixP->fx_pcrel_adjust = 0;
  fixP->fx_bit_fixP = 0;
  fixP->fx_addnumber = 0;
  fixP->tc_fix_data = NULL;

#ifdef TC_something
  fixP->fx_bsr = 0;
#endif
#ifdef TC_I960
  fixP->fx_callj = 0;
#endif

  as_where (&fixP->fx_file, &fixP->fx_line);

  /* Usually, we want relocs sorted numerically, but while
     comparing to older versions of gas that have relocs
     reverse sorted, it is convenient to have this compile
     time option.  xoxorich. */

  {

#ifdef BFD_ASSEMBLER
    fixS **seg_fix_rootP = & (seg_info (now_seg)->fix_root);
    fixS **seg_fix_tailP = & (seg_info (now_seg)->fix_tail);
#endif

#ifdef REVERSE_SORT_RELOCS

    fixP->fx_next = *seg_fix_rootP;
    *seg_fix_rootP = fixP;

#else /* REVERSE_SORT_RELOCS */

    fixP->fx_next = NULL;

    if (*seg_fix_tailP)
      (*seg_fix_tailP)->fx_next = fixP;
    else
      *seg_fix_rootP = fixP;
    *seg_fix_tailP = fixP;

#endif /* REVERSE_SORT_RELOCS */

  }

  return fixP;
}

/* Create a fixup relative to a symbol (plus a constant).  */

fixS *
fix_new (frag, where, size, add_symbol, offset, pcrel, r_type)
     fragS *frag;		/* Which frag? */
     int where;			/* Where in that frag? */
     short int size;		/* 1, 2, or 4 usually. */
     symbolS *add_symbol;	/* X_add_symbol. */
     offsetT offset;		/* X_add_number. */
     int pcrel;			/* TRUE if PC-relative relocation. */
#ifdef BFD_ASSEMBLER
     bfd_reloc_code_real_type r_type; /* Relocation type */
#else
     int r_type;		/* Relocation type */
#endif
{
  return fix_new_internal (frag, where, size, add_symbol,
			   (symbolS *) NULL, offset, pcrel, r_type);
}

/* Create a fixup for an expression.  Currently we only support fixups
   for difference expressions.  That is itself more than most object
   file formats support anyhow.  */

fixS *
fix_new_exp (frag, where, size, exp, pcrel, r_type)
     fragS *frag;		/* Which frag? */
     int where;			/* Where in that frag? */
     short int size;		/* 1, 2, or 4 usually. */
     expressionS *exp;		/* Expression.  */
     int pcrel;			/* TRUE if PC-relative relocation. */
#ifdef BFD_ASSEMBLER
     bfd_reloc_code_real_type r_type; /* Relocation type */
#else
     int r_type;		/* Relocation type */
#endif
{
  symbolS *add = NULL;
  symbolS *sub = NULL;
  offsetT off = 0;
  
  switch (exp->X_op)
    {
    case O_absent:
      break;

    case O_uminus:
      sub = exp->X_add_symbol;
      off = exp->X_add_number;
      break;

    case O_subtract:
      sub = exp->X_op_symbol;
      /* Fall through.  */
    case O_symbol:
      add = exp->X_add_symbol;
      /* Fall through.   */
    case O_constant:
      off = exp->X_add_number;
      break;
      
    default:
      as_bad ("expression too complex for fixup");
    }

  return fix_new_internal (frag, where, size, add, sub, off,
			   pcrel, r_type);
}

/* Append a string onto another string, bumping the pointer along.  */
void
append (charPP, fromP, length)
     char **charPP;
     char *fromP;
     unsigned long length;
{
  /* Don't trust memcpy() of 0 chars. */
  if (length == 0)
    return;

  memcpy (*charPP, fromP, length);
  *charPP += length;
}

#ifndef BFD_ASSEMBLER 
int section_alignment[SEG_MAXIMUM_ORDINAL];
#endif

/*
 * This routine records the largest alignment seen for each segment.
 * If the beginning of the segment is aligned on the worst-case
 * boundary, all of the other alignments within it will work.  At
 * least one object format really uses this info.
 */
void 
record_alignment (seg, align)
     /* Segment to which alignment pertains */
     segT seg;
     /* Alignment, as a power of 2 (e.g., 1 => 2-byte boundary, 2 => 4-byte
	boundary, etc.)  */
     int align;
{
#ifdef BFD_ASSEMBLER
  if (align > bfd_get_section_alignment (stdoutput, seg))
    bfd_set_section_alignment (stdoutput, seg, align);
#else
  if (align > section_alignment[(int) seg])
    section_alignment[(int) seg] = align;
#endif
}

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

static fragS *
chain_frchains_together_1 (section, frchp)
     segT section;
     struct frchain *frchp;
{
  fragS dummy, *prev_frag = &dummy;
  for (; frchp && frchp->frch_seg == section; frchp = frchp->frch_next)
    {
      prev_frag->fr_next = frchp->frch_root;
      prev_frag = frchp->frch_last;
    }
  prev_frag->fr_next = 0;
  return prev_frag;
}

#endif

#ifdef BFD_ASSEMBLER

static void
chain_frchains_together (abfd, section, xxx)
     bfd *abfd;			/* unused */
     segT section;
     char *xxx;			/* unused */
{
  segment_info_type *info;

  /* BFD may have introduced its own sections without using
     subseg_new, so it is possible that seg_info is NULL.  */
  info = seg_info (section);
  if (info != (segment_info_type *) NULL)
    chain_frchains_together_1 (section, info->frchainP);
}

#endif

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

void 
remove_subsegs (head, seg, root, last)
     frchainS *head;
     int seg;
     fragS **root;
     fragS **last;
{
  *root = head->frch_root;
  *last = chain_frchains_together_1 (seg, head);
}

#endif /* BFD */

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

#ifdef BFD_ASSEMBLER
static void
cvt_frag_to_fill (sec, fragP)
     segT sec;
     fragS *fragP;
#else
static void
cvt_frag_to_fill (headers, fragP)
     object_headers *headers;
     fragS *fragP;
#endif
{
  switch (fragP->fr_type)
    {
    case rs_align:
    case rs_org:
#ifdef HANDLE_ALIGN
      HANDLE_ALIGN (fragP);
#endif
      fragP->fr_type = rs_fill;
      know (fragP->fr_var == 1);
      know (fragP->fr_next != NULL);

      fragP->fr_offset = (fragP->fr_next->fr_address
			  - fragP->fr_address
			  - fragP->fr_fix);
      break;

    case rs_fill:
      break;

    case rs_machine_dependent:
#ifdef BFD_ASSEMBLER
      md_convert_frag (stdoutput, sec, fragP);
#else
      md_convert_frag (headers, fragP);
#endif

      assert (fragP->fr_next == NULL || (fragP->fr_next->fr_address - fragP->fr_address == fragP->fr_fix));

      /*
       * After md_convert_frag, we make the frag into a ".space 0".
       * Md_convert_frag() should set up any fixSs and constants
       * required.
       */
      frag_wane (fragP);
      break;

#ifndef WORKING_DOT_WORD
    case rs_broken_word:
      {
	struct broken_word *lie;

	if (fragP->fr_subtype)
	  {
	    fragP->fr_fix += md_short_jump_size;
	    for (lie = (struct broken_word *) (fragP->fr_symbol);
		 lie && lie->dispfrag == fragP;
		 lie = lie->next_broken_word)
	      if (lie->added == 1)
		fragP->fr_fix += md_long_jump_size;
	  }
	frag_wane (fragP);
      }
      break;
#endif

    default:
      BAD_CASE (fragP->fr_type);
      break;
    }
}

#endif /* defined (BFD_ASSEMBLER) || !defined (BFD) */

#ifdef BFD_ASSEMBLER
static void
relax_and_size_seg (abfd, sec, xxx)
     bfd *abfd;
     asection *sec;
     char *xxx;
{
  flagword flags;
  fragS *fragp;
  segment_info_type *seginfo;
  int x;
  valueT size, newsize;

  flags = bfd_get_section_flags (abfd, sec);

  seginfo = (segment_info_type *) bfd_get_section_userdata (abfd, sec);
  if (seginfo && seginfo->frchainP)
    {
      relax_segment (seginfo->frchainP->frch_root, sec);
      for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next)
	cvt_frag_to_fill (sec, fragp);
      for (fragp = seginfo->frchainP->frch_root;
	   fragp->fr_next;
	   fragp = fragp->fr_next)
	/* walk to last elt */;
      size = fragp->fr_address + fragp->fr_fix;
    }
  else
    size = 0;
  if (size > 0)
    {
      flags |= SEC_HAS_CONTENTS;
      /* @@ This is just an approximation.  */
      if (seginfo->fix_root)
	flags |= SEC_RELOC;
      else
	flags &= ~SEC_RELOC;
      x = bfd_set_section_flags (abfd, sec, flags);
      assert (x == true);
    }
  newsize = md_section_align (sec, size);
  x = bfd_set_section_size (abfd, sec, newsize);
  assert (x == true);

  /* If the size had to be rounded up, add some padding in the last
     non-empty frag.  */
  assert (newsize >= size);
  if (size != newsize)
    {
      fragS *last = seginfo->frchainP->frch_last;
      fragp = seginfo->frchainP->frch_root;
      while (fragp->fr_next != last)
	fragp = fragp->fr_next;
      last->fr_address = size;
      fragp->fr_offset += newsize - size;
    }

#ifdef tc_frob_section
  tc_frob_section (sec);
#endif
#ifdef obj_frob_section
  obj_frob_section (sec);
#endif
}

#ifdef DEBUG2
static void
dump_section_relocs (abfd, sec, stream_)
     bfd *abfd;
     asection *sec;
     char *stream_;
{
  FILE *stream = (FILE *) stream_;
  segment_info_type *seginfo = seg_info (sec);
  fixS *fixp = seginfo->fix_root;

  if (!fixp)
    return;

  fprintf (stream, "sec %s relocs:\n", sec->name);
  while (fixp)
    {
      symbolS *s = fixp->fx_addsy;
      if (s)
	fprintf (stream, "  %08x: %s(%s+%x)+%x\n", fixp,
		 S_GET_NAME (s), s->bsym->section->name,
		 S_GET_VALUE (s), fixp->fx_offset);
      else
	fprintf (stream, "  %08x: type %d no sym\n", fixp, fixp->fx_r_type);
      fixp = fixp->fx_next;
    }
}
#else
#define dump_section_relocs(ABFD,SEC,STREAM)	(void)(ABFD,SEC,STREAM)
#endif

static void
adjust_reloc_syms (abfd, sec, xxx)
     bfd *abfd;
     asection *sec;
     char *xxx;
{
  segment_info_type *seginfo = seg_info (sec);
  fixS *fixp;

  if (seginfo == NULL)
    return;

  dump_section_relocs (abfd, sec, stderr);

  for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
    if (fixp->fx_addsy)
      {
	symbolS *sym = fixp->fx_addsy;
	asection *symsec = sym->bsym->section;
	segment_info_type *symseginfo = seg_info (symsec);

	/* If it's one of these sections, assume the symbol is definitely
	   going to be output.  */
	if (symsec == &bfd_und_section
	    || symsec == &bfd_abs_section
	    || bfd_is_com_section (symsec))
	  {
	    fixp->fx_addsy->sy_used_in_reloc = 1;
	    continue;
	  }

	/* Since we're reducing to section symbols, don't attempt to reduce
	   anything that's already using one.  */
	if (sym->bsym == symsec->symbol)
	  {
	    fixp->fx_addsy->sy_used_in_reloc = 1;
	    continue;
	  }

	/* Is there some other reason we can't adjust this one?  (E.g.,
	   call/bal links in i960-bout symbols.)  */
#ifdef obj_fix_adjustable
	if (! obj_fix_adjustable (fixp))
	  {
	    fixp->fx_addsy->sy_used_in_reloc = 1;
	    continue;
	  }
#endif

	/* Is there some other (target cpu dependent) reason we can't adjust
	   this one?  (E.g. relocations involving function addresses on 
	   the PA.  */
#ifdef tc_fix_adjustable
	if (! tc_fix_adjustable (fixp))
	  {
	    fixp->fx_addsy->sy_used_in_reloc = 1;
	    continue;
	  }
#endif

	/* If the section symbol isn't going to be output, the relocs
	   at least should still work.  If not, figure out what to do
	   when we run into that case.  */
	fixp->fx_offset += S_GET_VALUE (sym);
	if (sym->sy_frag)
	  fixp->fx_offset += sym->sy_frag->fr_address;
	if (symseginfo->sym)
	  fixp->fx_addsy = symseginfo->sym;
	else
	  {
	    fixp->fx_addsy = symbol_find (symsec->name);
	    if (!fixp->fx_addsy)
	      {
		fixp->fx_addsy = symbol_make (symsec->name);
		fixp->fx_addsy->bsym = symsec->symbol;
	      }
	    symseginfo->sym = fixp->fx_addsy;
	  }
	fixp->fx_addsy->sy_used_in_reloc = 1;
      }

  dump_section_relocs (abfd, sec, stderr);
}

static void
write_relocs (abfd, sec, xxx)
     bfd *abfd;
     asection *sec;
     char *xxx;
{
  segment_info_type *seginfo = seg_info (sec);
  int i;
  unsigned int n;
  arelent **relocs;
  fixS *fixp;

  /* If seginfo is NULL, we did not create this section; don't do
     anything with it.  */
  if (seginfo == NULL)
    return;

  fixup_segment (seginfo->fix_root, sec);

  n = 0;
  for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next)
    n++;

#ifndef RELOC_EXPANSION_POSSIBLE
  /* Set up reloc information as well.  */
  relocs = (arelent **) bfd_alloc_by_size_t (stdoutput,
					     n * sizeof (arelent *));
  memset ((char*)relocs, 0, 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;

      if (fixp->fx_addsy == 0)
	{
	  /* @@ Need some other flag to indicate which have already
	     been performed...  */
	  n--;
	  continue;
	}
      reloc = tc_gen_reloc (sec, fixp);
      if (!reloc)
	{
	  n--;
	  continue;
	}
      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)
	abort ();
      /* Pass bogus address so that when bfd_perform_relocation adds
	 `address' back in, it'll come up with `data', which is where
	 we want it to operate.  */
      if (reloc->howto->partial_inplace == false
	  && reloc->howto->pcrel_offset == true
	  && reloc->howto->pc_relative == true)
	{
	  /* bfd_perform_relocation screws this up */
	  reloc->addend += reloc->address;
	}
      s = bfd_perform_relocation (stdoutput, reloc, data - reloc->address,
				  sec, stdoutput);
      switch (s)
	{
	case bfd_reloc_ok:
	  break;
	default:
	  as_fatal ("bad return from bfd_perform_relocation");
	}
      relocs[i++] = reloc;
    }
#else
  n = n * MAX_RELOC_EXPANSION;
  /* Set up reloc information as well.  */
  relocs = (arelent **) bfd_alloc_by_size_t (stdoutput,
					     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;
      int j;

      if (fixp->fx_addsy == 0)
	{
	  /* @@ Need some other flag to indicate which have already
	     been performed...  */
	  n--;
	  continue;
	}
      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)
	abort ();
      for (j = 0; reloc[j]; j++)
        {
          s = bfd_perform_relocation (stdoutput, reloc[j], data - reloc[j]->address,
				      sec, stdoutput);
          switch (s)
	    {
	      case bfd_reloc_ok:
	        break;
	      default:
	        as_fatal ("bad return from bfd_perform_relocation");
	    }
        }
    }
  n = i;
#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 DEBUG2
  {
    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;
     asection *sec;
     char *xxx;
{
  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);
	  assert (x == true);
	  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)
	while (count--)
	  {
	    x = bfd_set_section_contents (stdoutput, sec,
					  fill_literal, (file_ptr) offset,
					  (bfd_size_type) fill_size);
	    assert (x == true);
	    offset += 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;
	}			/* for each data frag */

      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;
	}			/* for each bss frag */
    }

  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)

void 
write_object_file ()
{
  register struct frchain *frchainP;	/* Track along all frchains. */
#if ! defined (BFD_ASSEMBLER) || ! defined (WORKING_DOT_WORD)
  register fragS *fragP;	/* Track along all frags. */
#endif
#if !defined (BFD_ASSEMBLER) && !defined (OBJ_VMS)
  long object_file_size;
#endif

  /* Do we really want to write it?  */
  {
    int n_warns, n_errs;
    n_warns = had_warnings ();
    n_errs = had_errors ();
    /* The -Z flag indicates that an object file should be generated,
       regardless of warnings and errors.  */
    if (flagseen['Z'])
      {
	if (n_warns || n_errs)
	  as_warn ("%d error%s, %d warning%s, generating bad object file.\n",
		   n_errs, n_errs == 1 ? "" : "s",
		   n_warns, n_warns == 1 ? "" : "s");
      }
    else
      {
	if (n_errs)
	  as_fatal ("%d error%s, %d warning%s, no object file generated.\n",
		    n_errs, n_errs == 1 ? "" : "s",
		    n_warns, n_warns == 1 ? "" : "s");
      }
  }

#ifdef	OBJ_VMS
  /*
   *	Under VMS we try to be compatible with VAX-11 "C".  Thus, we
   *	call a routine to check for the definition of the procedure
   *	"_main", and if so -- fix it up so that it can be program
   *	entry point.
   */
  VMS_Check_For_Main ();
#endif /* VMS */

  /* 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.

     @@ Is this really necessary??  */
#ifndef SUB_SEGMENT_ALIGN
#ifdef BFD_ASSEMBLER
#define SUB_SEGMENT_ALIGN(SEG) (0)
#else
#define SUB_SEGMENT_ALIGN(SEG) (2)
#endif
#endif
  for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next)
    {
      subseg_set (frchainP->frch_seg, frchainP->frch_subseg);
      frag_align (SUB_SEGMENT_ALIGN (now_seg), NOP_OPCODE);
      /* frag_align will have left a new frag.
	 Use this last frag for an empty ".fill".

	 For this segment ...
	 Create a last frag. Do not leave a "being filled in frag".  */
      frag_wane (frag_now);
      frag_now->fr_fix = 0;
      know (frag_now->fr_next == NULL);
    }

  /* From now on, we don't care about sub-segments.  Build one frag chain
     for each segment. Linked thru fr_next.  */

#ifdef BFD_ASSEMBLER
  /* Remove the sections created by gas for its own purposes.  */
  {
    asection **seclist, *sec;
    seclist = &stdoutput->sections;
    while (seclist && *seclist)
      {
	sec = *seclist;
	while (sec == reg_section || sec == expr_section)
	  {
	    sec = sec->next;
	    *seclist = sec;
	    stdoutput->section_count--;
	    if (!sec)
	      break;
	  }
	if (*seclist)
	  seclist = &(*seclist)->next;
      }
  }

  bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0);
#else
  remove_subsegs (frchain_root, SEG_TEXT, &text_frag_root, &text_last_frag);
  remove_subsegs (data0_frchainP, SEG_DATA, &data_frag_root, &data_last_frag);
  remove_subsegs (bss0_frchainP, SEG_BSS, &bss_frag_root, &bss_last_frag);
#endif

  /* We have two segments. If user gave -R flag, then we must put the
     data frags into the text segment. Do this before relaxing so
     we know to take advantage of -R and make shorter addresses.  */
#if !defined (OBJ_AOUT) || defined (BFD_ASSEMBLER)
  if (flagseen['R'])
    {
      merge_data_into_text ();
    }
#endif

#ifdef BFD_ASSEMBLER
  bfd_map_over_sections (stdoutput, relax_and_size_seg, (char *) 0);
#else
  relax_and_size_all_segments ();
#endif /* BFD_ASSEMBLER */

#ifndef BFD_ASSEMBLER
  /*
   *
   * Crawl the symbol chain.
   *
   * For each symbol whose value depends on a frag, take the address of
   * that frag and subsume it into the value of the symbol.
   * After this, there is just one way to lookup a symbol value.
   * Values are left in their final state for object file emission.
   * We adjust the values of 'L' local symbols, even if we do
   * not intend to emit them to the object file, because their values
   * are needed for fix-ups.
   *
   * Unless we saw a -L flag, remove all symbols that begin with 'L'
   * from the symbol chain.  (They are still pointed to by the fixes.)
   *
   * Count the remaining symbols.
   * Assign a symbol number to each symbol.
   * Count the number of string-table chars we will emit.
   * Put this info into the headers as appropriate.
   *
   */
  know (zero_address_frag.fr_address == 0);
  string_byte_count = sizeof (string_byte_count);

  obj_crawl_symbol_chain (&headers);

  if (string_byte_count == sizeof (string_byte_count))
    string_byte_count = 0;

  H_SET_STRING_SIZE (&headers, string_byte_count);

  /*
   * Addresses of frags now reflect addresses we use in the object file.
   * Symbol values are correct.
   * Scan the frags, converting any ".org"s and ".align"s to ".fill"s.
   * Also converting any machine-dependent frags using md_convert_frag();
   */
  subseg_change (SEG_TEXT, 0);

  for (fragP = text_frag_root; fragP; fragP = fragP->fr_next)
    {
      cvt_frag_to_fill (&headers, fragP);

      /* Some assert macros don't work with # directives mixed in.  */
#ifndef NDEBUG
      if (!(fragP->fr_next == NULL
#ifdef OBJ_BOUT
	    || fragP->fr_next == data_frag_root
#endif
	    || ((fragP->fr_next->fr_address - fragP->fr_address)
		== (fragP->fr_fix + fragP->fr_offset * fragP->fr_var))))
	abort ();
#endif
    }
#endif /* ! BFD_ASSEMBLER */

#ifndef WORKING_DOT_WORD
  {
    struct broken_word *lie;
    struct broken_word **prevP;

    prevP = &broken_words;
    for (lie = broken_words; lie; lie = lie->next_broken_word)
      if (!lie->added)
	{
	  expressionS exp;

	  exp.X_op = O_subtract;
	  exp.X_add_symbol = lie->add;
	  exp.X_op_symbol = lie->sub;
	  exp.X_add_number = lie->addnum;
#ifdef BFD_ASSEMBLER
	  fix_new_exp (lie->frag,
		       lie->word_goes_here - lie->frag->fr_literal,
		       2, &exp, 0, BFD_RELOC_NONE);
#else
#if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE)
	  fix_new_exp (lie->frag,
		       lie->word_goes_here - lie->frag->fr_literal,
		       2, &exp, 0, NO_RELOC);
#else
#ifdef TC_NS32K
	  fix_new_ns32k_exp (lie->frag,
			     lie->word_goes_here - lie->frag->fr_literal,
			     2, &exp, 0, 0, 2, 0, 0);
#else
	  fix_new_exp (lie->frag,
		       lie->word_goes_here - lie->frag->fr_literal,
		       2, &exp, 0, 0);
#endif /* TC_NS32K */
#endif /* TC_SPARC|TC_A29K|NEED_FX_R_TYPE */
#endif /* BFD_ASSEMBLER */
	  *prevP = lie->next_broken_word;
	}
      else
	prevP = &(lie->next_broken_word);

    for (lie = broken_words; lie;)
      {
	struct broken_word *untruth;
	char *table_ptr;
	addressT table_addr;
	addressT from_addr, to_addr;
	int n, m;

	fragP = lie->dispfrag;

	/* Find out how many broken_words go here.  */
	n = 0;
	for (untruth = lie; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word)
	  if (untruth->added == 1)
	    n++;

	table_ptr = lie->dispfrag->fr_opcode;
	table_addr = lie->dispfrag->fr_address + (table_ptr - lie->dispfrag->fr_literal);
	/* Create the jump around the long jumps.  This is a short
	   jump from table_ptr+0 to table_ptr+n*long_jump_size.  */
	from_addr = table_addr;
	to_addr = table_addr + md_short_jump_size + n * md_long_jump_size;
	md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
	table_ptr += md_short_jump_size;
	table_addr += md_short_jump_size;

	for (m = 0; lie && lie->dispfrag == fragP; m++, lie = lie->next_broken_word)
	  {
	    if (lie->added == 2)
	      continue;
	    /* Patch the jump table */
	    /* This is the offset from ??? to table_ptr+0 */
	    to_addr = table_addr - S_GET_VALUE (lie->sub);
	    md_number_to_chars (lie->word_goes_here, to_addr, 2);
	    for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word)
	      {
		if (untruth->use_jump == lie)
		  md_number_to_chars (untruth->word_goes_here, to_addr, 2);
	      }

	    /* Install the long jump */
	    /* this is a long jump from table_ptr+0 to the final target */
	    from_addr = table_addr;
	    to_addr = S_GET_VALUE (lie->add) + lie->addnum;
	    md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add);
	    table_ptr += md_long_jump_size;
	    table_addr += md_long_jump_size;
	  }
      }
  }
#endif /* not WORKING_DOT_WORD */

#ifndef BFD_ASSEMBLER
#ifndef	OBJ_VMS
  {				/* not vms */
    /*
     * Scan every FixS performing fixups. We had to wait until now to do
     * this because md_convert_frag() may have made some fixSs.
     */
    int trsize, drsize;

    subseg_change (SEG_TEXT, 0);
    trsize = md_reloc_size * fixup_segment (text_fix_root, SEG_TEXT);
    subseg_change (SEG_DATA, 0);
    drsize = md_reloc_size * fixup_segment (data_fix_root, SEG_DATA);
    H_SET_RELOCATION_SIZE (&headers, trsize, drsize);

    /* FIXME move this stuff into the pre-write-hook */
    H_SET_MAGIC_NUMBER (&headers, magic_number_for_object_file);
    H_SET_ENTRY_POINT (&headers, 0);

    obj_pre_write_hook (&headers);	/* extra coff stuff */

    object_file_size = H_GET_FILE_SIZE (&headers);
    next_object_file_charP = the_object_file = xmalloc (object_file_size);

    output_file_create (out_file_name);

    obj_header_append (&next_object_file_charP, &headers);

    know ((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE (&headers));

    /*
     * Emit code.
     */
    for (fragP = text_frag_root; fragP; fragP = fragP->fr_next)
      {
	register long count;
	register char *fill_literal;
	register long fill_size;

	know (fragP->fr_type == rs_fill);
	append (&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix);
	fill_literal = fragP->fr_literal + fragP->fr_fix;
	fill_size = fragP->fr_var;
	know (fragP->fr_offset >= 0);

	for (count = fragP->fr_offset; count; count--)
	  {
	    append (&next_object_file_charP, fill_literal, (unsigned long) fill_size);
	  }			/* for each  */

      }				/* for each code frag. */

    know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers)));

    /*
     * Emit relocations.
     */
    obj_emit_relocations (&next_object_file_charP, text_fix_root, (relax_addressT) 0);
    know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers)));
#ifdef TC_I960
    /* Make addresses in data relocation directives relative to beginning of
     * first data fragment, not end of last text fragment:  alignment of the
     * start of the data segment may place a gap between the segments.
     */
    obj_emit_relocations (&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address);
#else /* TC_I960 */
    obj_emit_relocations (&next_object_file_charP, data_fix_root, text_last_frag->fr_address);
#endif /* TC_I960 */

    know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers)));

    /*
     * Emit line number entries.
     */
    OBJ_EMIT_LINENO (&next_object_file_charP, lineno_rootP, the_object_file);
    know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers)));

    /*
     * Emit symbols.
     */
    obj_emit_symbols (&next_object_file_charP, symbol_rootP);
    know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers) + H_GET_SYMBOL_TABLE_SIZE (&headers)));

    /*
     * Emit strings.
     */

    if (string_byte_count > 0)
      {
	obj_emit_strings (&next_object_file_charP);
      }				/* only if we have a string table */

#ifdef BFD_HEADERS
    bfd_seek (stdoutput, 0, 0);
    bfd_write (the_object_file, 1, object_file_size, stdoutput);
#else

    /* Write the data to the file */
    output_file_append (the_object_file, object_file_size, out_file_name);
#endif

    output_file_close (out_file_name);
  }				/* non vms output */
#else /* VMS */
  /*
   *	Now do the VMS-dependent part of writing the object file
   */
  VMS_write_object_file (H_GET_TEXT_SIZE (&headers),
			 H_GET_DATA_SIZE (&headers),
			 H_GET_BSS_SIZE (&headers),
			 text_frag_root, data_frag_root);
#endif /* VMS */
#else /* BFD_ASSEMBLER */

#ifdef obj_check_file_symbols
  obj_check_file_symbols ();
#endif

  bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *)0);

  /* Set up symbol table, and write it out.  */
  if (symbol_rootP)
    {
      unsigned int i = 0;
      unsigned int n;
      symbolS *symp;

      for (symp = symbol_rootP; symp; symp = symbol_next (symp))
	{
	  if (! symp->sy_resolved)
	    {
	      if (symp->sy_value.X_op == O_constant)
		{
		  /* This is the normal case; skip the call.  */
		  S_SET_VALUE (symp,
			       (S_GET_VALUE (symp)
				+ symp->sy_frag->fr_address));
		  symp->sy_resolved = 1;
		}
	      else
		resolve_symbol_value (symp);
	    }

	  /* So far, common symbols have been treated like undefined symbols.
	     Put them in the common section now.  */
	  if (S_IS_DEFINED (symp) == 0
	      && S_GET_VALUE (symp) != 0)
	    S_SET_SEGMENT (symp, &bfd_com_section);
#if 0
	  printf ("symbol `%s'\n\t@%x: value=%d flags=%x seg=%s\n",
		  S_GET_NAME (symp), symp,
		  S_GET_VALUE (symp),
		  symp->bsym->flags,
		  segment_name (symp->bsym->section));
#endif
	  if (! symp->sy_used_in_reloc)
	    {
#ifdef obj_frob_symbol
	      {
		int punt = 0;
		obj_frob_symbol (symp, punt);
		if (punt)
		  goto punt_it;
	      }
#endif
#ifdef tc_frob_symbol
	      {
		int punt = 0;
		tc_frob_symbol (symp, punt);
		if (punt)
		  goto punt_it;
	      }
#endif
	    }

	  /* If we don't want to keep this symbol, splice it out of the
	     chain now.  */
	  if (! symp->sy_used_in_reloc
	      && S_IS_LOCAL (symp))
	    {
	      symbolS *prev, *next;
#if defined (obj_frob_symbol) || defined (tc_frob_symbol)
	    punt_it:
#endif
	      prev = symbol_previous (symp);
	      next = symbol_next (symp);
#ifdef DEBUG_SYMS
	      verify_symbol_chain_2 (symp);
#endif
	      if (prev)
		{
		  symbol_next (prev) = next;
		  symp = prev;
		}
	      else if (symp == symbol_rootP)
		symbol_rootP = next;
	      else
		abort ();
	      if (next)
		symbol_previous (next) = prev;
	      else
		symbol_lastP = prev;
#ifdef DEBUG_SYMS
	      if (prev)
		verify_symbol_chain_2 (prev);
	      else if (next)
		verify_symbol_chain_2 (next);
#endif
	      continue;
	    }

	  /* Make sure we really got a value for the symbol.  */
	  if (! symp->sy_resolved)
	    {
	      as_bad ("can't resolve value for symbol \"%s\"",
		      S_GET_NAME (symp));
	      symp->sy_resolved = 1;
	    }

	  /* Set the value into the BFD symbol.  Up til now the value
	     has only been kept in the gas symbolS struct.  */
	  symp->bsym->value = S_GET_VALUE (symp);

	  i++;
	}
      n = i;
      if (n)
	{
	  asymbol **asympp;
	  boolean result;
	  extern PTR bfd_alloc PARAMS ((bfd *, size_t));

	  asympp = (asymbol **) bfd_alloc (stdoutput,
					   n * sizeof (asymbol *));
	  symp = symbol_rootP;
	  for (i = 0; i < n; i++, symp = symbol_next (symp))
	    {
	      asympp[i] = symp->bsym;
	      symp->written = 1;
	    }
	  result = bfd_set_symtab (stdoutput, asympp, n);
	  assert (result == true);
	}
    }


#ifdef obj_frob_file
  /* If obj_frob_file changes the symbol value at this point, it is
     responsible for moving the changed value into symp->bsym->value
     as well.  Hopefully all symbol value changing can be done in
     {obj,tc}_frob_symbol.  */
  obj_frob_file ();
#endif

  /* Now that all the sizes are known, and contents correct, we can
     start writing the file.  */
  bfd_map_over_sections (stdoutput, write_relocs, (char *) 0);

  bfd_map_over_sections (stdoutput, write_contents, (char *) 0);

  output_file_close (out_file_name);
#endif /* BFD_ASSEMBLER */
}
#endif /* ! BFD */

/*
 *			relax_segment()
 *
 * Now we have a segment, not a crowd of sub-segments, we can make fr_address
 * values.
 *
 * Relax the frags.
 *
 * After this, all frags in this segment have addresses that are correct
 * within the segment. Since segments live in different file addresses,
 * these frag addresses may not be the same as final object-file addresses.
 */

/* Subroutines of relax_segment.  */
static int 
is_dnrange (f1, f2)
     struct frag *f1;
     struct frag *f2;
{
  for (; f1; f1 = f1->fr_next)
    if (f1->fr_next == f2)
      return 1;
  return 0;
}

/* Relax_align. Advance location counter to next address that has 'alignment'
   lowest order bits all 0s, return size of adjustment made.  */
static relax_addressT
relax_align (address, alignment)
     register relax_addressT address;	/* Address now. */
     register int alignment;	/* Alignment (binary). */
{
  relax_addressT mask;
  relax_addressT new_address;

  mask = ~((~0) << alignment);
  new_address = (address + mask) & (~mask);
  if (linkrelax)
    /* We must provide lots of padding, so the linker can discard it
       when needed.  The linker will not add extra space, ever.  */
    new_address += (1 << alignment);
  return (new_address - address);
}

void 
relax_segment (segment_frag_root, segment)
     struct frag *segment_frag_root;
     segT segment;
{
  register struct frag *fragP;
  register relax_addressT address;
#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
  know (segment == SEG_DATA || segment == SEG_TEXT || segment == SEG_BSS);
#endif
  /* In case md_estimate_size_before_relax() wants to make fixSs. */
  subseg_change (segment, 0);

  /* For each frag in segment: count and store  (a 1st guess of)
     fr_address.  */
  address = 0;
  for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
    {
      fragP->fr_address = address;
      address += fragP->fr_fix;

      switch (fragP->fr_type)
	{
	case rs_fill:
	  address += fragP->fr_offset * fragP->fr_var;
	  break;

	case rs_align:
	  address += relax_align (address, (int) fragP->fr_offset);
	  break;

	case rs_org:
	  /* Assume .org is nugatory. It will grow with 1st relax.  */
	  break;

	case rs_machine_dependent:
	  address += md_estimate_size_before_relax (fragP, segment);
	  break;

#ifndef WORKING_DOT_WORD
	  /* Broken words don't concern us yet */
	case rs_broken_word:
	  break;
#endif

	default:
	  BAD_CASE (fragP->fr_type);
	  break;
	}			/* switch(fr_type) */
    }				/* for each frag in the segment */

  /* Do relax().  */
  {
    long stretch;	/* May be any size, 0 or negative. */
    /* Cumulative number of addresses we have */
    /* relaxed this pass. */
    /* We may have relaxed more than one address. */
    long stretched;	/* Have we stretched on this pass? */
    /* This is 'cuz stretch may be zero, when, in fact some piece of code
       grew, and another shrank.  If a branch instruction doesn't fit anymore,
       we could be scrod.  */

    do
      {
	stretch = stretched = 0;
	for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next)
	  {
	    long growth = 0;
	    unsigned long was_address;
	    long offset;
	    symbolS *symbolP;
	    long target;
	    long after;

	    was_address = fragP->fr_address;
	    address = fragP->fr_address += stretch;
	    symbolP = fragP->fr_symbol;
	    offset = fragP->fr_offset;

	    switch (fragP->fr_type)
	      {
	      case rs_fill:	/* .fill never relaxes. */
		growth = 0;
		break;

#ifndef WORKING_DOT_WORD
		/* JF:  This is RMS's idea.  I do *NOT* want to be blamed
		   for it I do not want to write it.  I do not want to have
		   anything to do with it.  This is not the proper way to
		   implement this misfeature.  */
	      case rs_broken_word:
		{
		  struct broken_word *lie;
		  struct broken_word *untruth;

		  /* Yes this is ugly (storing the broken_word pointer
		     in the symbol slot).  Still, this whole chunk of
		     code is ugly, and I don't feel like doing anything
		     about it.  Think of it as stubbornness in action.  */
		  growth = 0;
		  for (lie = (struct broken_word *) (fragP->fr_symbol);
		       lie && lie->dispfrag == fragP;
		       lie = lie->next_broken_word)
		    {

		      if (lie->added)
			continue;

		      offset = (lie->add->sy_frag->fr_address
				+ S_GET_VALUE (lie->add)
				+ lie->addnum
				- (lie->sub->sy_frag->fr_address
				   + S_GET_VALUE (lie->sub)));
		      if (offset <= -32768 || offset >= 32767)
			{
			  if (flagseen['K'])
			    {
			      char buf[50];
			      sprint_value (buf, (addressT) lie->addnum);
			      as_warn (".word %s-%s+%s didn't fit",
				       S_GET_NAME (lie->add),
				       S_GET_NAME (lie->sub),
				       buf);
			    }
			  lie->added = 1;
			  if (fragP->fr_subtype == 0)
			    {
			      fragP->fr_subtype++;
			      growth += md_short_jump_size;
			    }
			  for (untruth = lie->next_broken_word;
			       untruth && untruth->dispfrag == lie->dispfrag;
			       untruth = untruth->next_broken_word)
			    if ((untruth->add->sy_frag == lie->add->sy_frag)
				&& S_GET_VALUE (untruth->add) == S_GET_VALUE (lie->add))
			      {
				untruth->added = 2;
				untruth->use_jump = lie;
			      }
			  growth += md_long_jump_size;
			}
		    }

		  break;
		}		/* case rs_broken_word */
#endif
	      case rs_align:
		growth = (relax_align ((relax_addressT) (address
							 + fragP->fr_fix),
				       (int) offset)
			  - relax_align ((relax_addressT) (was_address
							   + fragP->fr_fix),
					 (int) offset));
		break;

	      case rs_org:
		target = offset;

		if (symbolP)
		  {
#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
		    know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
			  || (S_GET_SEGMENT (symbolP) == SEG_DATA)
			  || (S_GET_SEGMENT (symbolP) == SEG_TEXT)
			  || S_GET_SEGMENT (symbolP) == SEG_BSS);
		    know (symbolP->sy_frag);
		    know (!(S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
			  || (symbolP->sy_frag == &zero_address_frag));
#endif
		    target += S_GET_VALUE (symbolP)
		      + symbolP->sy_frag->fr_address;
		  }		/* if we have a symbol */

		know (fragP->fr_next);
		after = fragP->fr_next->fr_address;
		growth = ((target - after) > 0) ? (target - after) : 0;
		/* Growth may be negative, but variable part of frag
		   cannot have fewer than 0 chars.  That is, we can't
		   .org backwards. */

		growth -= stretch;	/* This is an absolute growth factor */
		break;

	      case rs_machine_dependent:
		{
		  const relax_typeS *this_type;
		  const relax_typeS *start_type;
		  relax_substateT next_state;
		  relax_substateT this_state;
		  long aim;

		  this_state = fragP->fr_subtype;
		  start_type = this_type = md_relax_table + this_state;
		  target = offset;

		  if (symbolP)
		    {
#ifndef DIFF_EXPR_OK
#if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER)
		      know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE)
			    || (S_GET_SEGMENT (symbolP) == SEG_DATA)
			    || (S_GET_SEGMENT (symbolP) == SEG_BSS)
			    || (S_GET_SEGMENT (symbolP) == SEG_TEXT));
#endif
		      know (symbolP->sy_frag);
#endif
		      know (!(S_GET_SEGMENT (symbolP) == absolute_section)
			    || symbolP->sy_frag == &zero_address_frag);
		      target +=
			S_GET_VALUE (symbolP)
			+ symbolP->sy_frag->fr_address;

		      /* If frag has yet to be reached on this pass,
			 assume it will move by STRETCH just as we did.
			 If this is not so, it will be because some frag
			 between grows, and that will force another pass.

			 Beware zero-length frags.

			 There should be a faster way to do this.  */

		      if (symbolP->sy_frag->fr_address >= was_address
			  && is_dnrange (fragP, symbolP->sy_frag))
			{
			  target += stretch;
			}
		    }

		  aim = target - address - fragP->fr_fix;
		  /* The displacement is affected by the instruction size
		     for the 32k architecture. I think we ought to be able
		     to add fragP->fr_pcrel_adjust in all cases (it should be
		     zero if not used), but just in case it breaks something
		     else we'll put this inside #ifdef NS32K ... #endif  */
#ifndef TC_NS32K
		  if (fragP->fr_pcrel_adjust)
		    abort ();
#endif
		  aim += fragP->fr_pcrel_adjust;

		  if (aim < 0)
		    {
		      /* Look backwards. */
		      for (next_state = this_type->rlx_more; next_state;)
			if (aim >= this_type->rlx_backward)
			  next_state = 0;
			else
			  {
			    /* Grow to next state. */
			    this_state = next_state;
			    this_type = md_relax_table + this_state;
			    next_state = this_type->rlx_more;
			  }
		    }
		  else
		    {
#ifdef M68K_AIM_KLUDGE
		      M68K_AIM_KLUDGE (aim, this_state, this_type);
#endif
		      /* Look forwards. */
		      for (next_state = this_type->rlx_more; next_state;)
			if (aim <= this_type->rlx_forward)
			  next_state = 0;
			else
			  {
			    /* Grow to next state. */
			    this_state = next_state;
			    this_type = md_relax_table + this_state;
			    next_state = this_type->rlx_more;
			  }
		    }

		  growth = this_type->rlx_length - start_type->rlx_length;
		  if (growth != 0)
		    fragP->fr_subtype = this_state;
		}
		break;

	      default:
		BAD_CASE (fragP->fr_type);
		break;
	      }
	    if (growth)
	      {
		stretch += growth;
		stretched++;
	      }
	  }			/* For each frag in the segment. */
      }
    while (stretched);		/* Until nothing further to relax. */
  }				/* do_relax */

  /*
   * We now have valid fr_address'es for each frag.
   */

  /*
   * All fr_address's are correct, relative to their own segment.
   * We have made all the fixS we will ever make.
   */
}				/* relax_segment() */

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

/* fixup_segment()

   Go through all the fixS's in a segment and see which ones can be
   handled now.  (These consist of fixS where we have since discovered
   the value of a symbol, or the address of the frag involved.)
   For each one, call md_apply_fix to put the fix into the frag data.

   Result is a count of how many relocation structs will be needed to
   handle the remaining fixS's that we couldn't completely handle here.
   These will be output later by emit_relocations().  */

static long
fixup_segment (fixP, this_segment_type)
     register fixS *fixP;
     segT this_segment_type;	/* N_TYPE bits for segment. */
{
  register long seg_reloc_count;
  register symbolS *add_symbolP;
  register symbolS *sub_symbolP;
  valueT add_number;
  register int size;
  register char *place;
  register long where;
  register char pcrel;
  register fragS *fragP;
  register segT add_symbol_segment = absolute_section;

  seg_reloc_count = 0;
  /* If the linker is doing the relaxing, we must not do any fixups.  */
  /* Well, strictly speaking that's not true -- we could do any that
     are PC-relative and don't cross regions that could change size.
     And for the i960 (the only machine for which we've got a relaxing
     linker right now), we might be able to turn callx/callj into bal
     in cases where we know the maximum displacement.  */
  if (linkrelax)
    for (; fixP; fixP = fixP->fx_next)
      seg_reloc_count++;
  else
    for (; fixP; fixP = fixP->fx_next)
      {
	fragP = fixP->fx_frag;
	know (fragP);
	where = fixP->fx_where;
	place = fragP->fr_literal + where;
	size = fixP->fx_size;
	add_symbolP = fixP->fx_addsy;
#ifdef TC_I960
	if (fixP->fx_callj && TC_S_IS_CALLNAME (add_symbolP))
	  {
	    /* Relocation should be done via the associated 'bal'
	       entry point symbol. */

	    if (!TC_S_IS_BALNAME (tc_get_bal_of_call (add_symbolP)))
	      {
		as_bad ("No 'bal' entry point for leafproc %s",
			S_GET_NAME (add_symbolP));
		continue;
	      }
	    fixP->fx_addsy = add_symbolP = tc_get_bal_of_call (add_symbolP);
	  }
#endif
	sub_symbolP = fixP->fx_subsy;
	add_number = fixP->fx_offset;
	pcrel = fixP->fx_pcrel;

	if (add_symbolP)
	  add_symbol_segment = S_GET_SEGMENT (add_symbolP);

	if (sub_symbolP)
	  {
	    if (!add_symbolP)
	      {
		/* Its just -sym */
		/* @@ Should try converting to pcrel ref to fixed addr.  */
		if (S_GET_SEGMENT (sub_symbolP) != absolute_section)
		  as_bad ("Negative of non-absolute symbol %s",
			  S_GET_NAME (sub_symbolP));

		add_number -= S_GET_VALUE (sub_symbolP);
	      }
	    else if ((S_GET_SEGMENT (sub_symbolP) == add_symbol_segment)
		     && (SEG_NORMAL (add_symbol_segment)
			 || (add_symbol_segment == absolute_section)))
	      {
		/* Difference of 2 symbols from same segment.
		   Can't make difference of 2 undefineds: 'value' means
		   something different for N_UNDF. */
#ifdef TC_I960
		/* Makes no sense to use the difference of 2 arbitrary symbols
		   as the target of a call instruction.  */
		if (fixP->fx_callj)
		  {
		    as_bad ("callj to difference of 2 symbols");
		  }
#endif /* TC_I960 */
		add_number += S_GET_VALUE (add_symbolP) -
		  S_GET_VALUE (sub_symbolP);

		add_symbolP = NULL;
		fixP->fx_addsy = NULL;
	      }
#if !defined(SEG_DIFF_ALLOWED) && !defined (GLOBAL_DIFF_ALLOWED)
	    else
	      {
		/* Different segments in subtraction. */
		know (!(S_IS_EXTERNAL (sub_symbolP)
			&& (S_GET_SEGMENT (sub_symbolP) == absolute_section)));

		if ((S_GET_SEGMENT (sub_symbolP) == absolute_section))
		  {
		    add_number -= S_GET_VALUE (sub_symbolP);
		  }
#ifdef DIFF_EXPR_OK
		else if (!pcrel
			 && S_GET_SEGMENT (sub_symbolP) == this_segment_type)
		  {
		    /* Make it pc-relative.  */
		    add_number += (md_pcrel_from (fixP)
				   - S_GET_VALUE (sub_symbolP));
		    pcrel = 1;
		    fixP->fx_pcrel = 1;
		    sub_symbolP = 0;
		    fixP->fx_subsy = 0;
		  }
#endif
		else
		  {
		    char buf[50];
		    sprint_value (buf, fragP->fr_address + where);
		    as_bad ("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %s.",
			    segment_name (S_GET_SEGMENT (sub_symbolP)),
			    S_GET_NAME (sub_symbolP), buf);
		  }
	      }
#else
              else
                {
                  seg_reloc_count++;
		  fixP->fx_addnumber = add_number;	/* Remember value for emit_reloc */
                  continue;
                }		/* if absolute */
#endif
	  }

	if (add_symbolP)
	  {
	    if (add_symbol_segment == this_segment_type && pcrel)
	      {
		/*
		 * This fixup was made when the symbol's segment was
		 * SEG_UNKNOWN, but it is now in the local segment.
		 * So we know how to do the address without relocation.
		 */
#ifdef TC_I960
		/* reloc_callj() may replace a 'call' with a 'calls' or a
		   'bal', in which cases it modifies *fixP as appropriate.
		   In the case of a 'calls', no further work is required,
		   and *fixP has been set up to make the rest of the code
		   below a no-op. */
		reloc_callj (fixP);
#endif /* TC_I960 */

		add_number += S_GET_VALUE (add_symbolP);
		add_number -= md_pcrel_from (fixP);
		pcrel = 0;	/* Lie. Don't want further pcrel processing. */
#ifndef TC_HPPA
		fixP->fx_addsy = NULL;	/* No relocations please. */
#endif
	      }
	    else
	      {
		if (add_symbol_segment == absolute_section)
		  {
#ifdef TC_I960
		    /* See comment about reloc_callj() above.  */
		    reloc_callj (fixP);
#endif /* TC_I960 */
		    add_number += S_GET_VALUE (add_symbolP);
		    fixP->fx_addsy = NULL;
		    add_symbolP = NULL;
		  }
		else if (add_symbol_segment == undefined_section
#ifdef BFD_ASSEMBLER
			 || bfd_is_com_section (add_symbol_segment)
#endif
			 )
		  {
#ifdef TC_I960
		    if ((int) fixP->fx_bit_fixP == 13)
		      {
			/* This is a COBR instruction.  They have only a
			 * 13-bit displacement and are only to be used
			 * for local branches: flag as error, don't generate
			 * relocation.
			 */
			as_bad ("can't use COBR format with external label");
			fixP->fx_addsy = NULL;	/* No relocations please. */
			continue;
		      }		/* COBR */
#endif /* TC_I960 */

#ifdef OBJ_COFF
#ifdef TE_I386AIX
		    if (S_IS_COMMON (add_symbolP))
		      add_number += S_GET_VALUE (add_symbolP);
#endif /* TE_I386AIX */
#endif /* OBJ_COFF */
		    ++seg_reloc_count;
		  }
		else
		  {
		    seg_reloc_count++;
		    add_number += S_GET_VALUE (add_symbolP);
		  }
	      }
	  }

	if (pcrel)
	  {
	    add_number -= md_pcrel_from (fixP);
	    if (add_symbolP == 0)
	      {
		fixP->fx_addsy = &abs_symbol;
		++seg_reloc_count;
	      }			/* if there's an add_symbol */
	  }			/* if pcrel */

	if (!fixP->fx_bit_fixP && size > 0)
	  {
	    valueT mask = 0;
	    /* set all bits to one */
	    mask--;
	    /* Technically speaking, combining these produces an
	       undefined result if size is sizeof (valueT), though I
	       think these two half-way operations should both be
	       defined.  */
	    mask <<= size * 4;
	    mask <<= size * 4;
	    if ((add_number & mask) != 0
		&& (add_number & mask) != mask)
	      {
		char buf[50], buf2[50];
		sprint_value (buf, fragP->fr_address + where);
		if (add_number > 1000)
		  sprint_value (buf2, add_number);
		else
		  sprintf (buf2, "%ld", (long) add_number);
		as_bad_where (fixP->fx_file, fixP->fx_line,
			      "Value of %s too large for field of %d bytes at %s",
			      buf2, size, buf);
	      }			/* generic error checking */
#ifdef WARN_SIGNED_OVERFLOW_WORD
	    /* Warn if a .word value is too large when treated as a signed
	       number.  We already know it is not too negative.  This is to
	       catch over-large switches generated by gcc on the 68k.  */
	    if (!flagseen['J']
		&& size == 2
		&& add_number > 0x7fff)
	      as_bad_where (fixP->fx_file, fixP->fx_line,
			    "Signed .word overflow; switch may be too large; %ld at 0x%lx",
			    (long) add_number,
			    (unsigned long) (fragP->fr_address + where));
#endif
	  }			/* not a bit fix */

#ifdef BFD_ASSEMBLER
	md_apply_fix (fixP, &add_number);
#else
	md_apply_fix (fixP, add_number);
#endif
      }				/* For each fixS in this segment. */

#if defined (OBJ_COFF) && defined (TC_I960)
  {
    fixS *topP = fixP;

    /* two relocs per callj under coff. */
    for (fixP = topP; fixP; fixP = fixP->fx_next)
      if (fixP->fx_callj && fixP->fx_addsy != 0)
	++seg_reloc_count;
  }
#endif /* OBJ_COFF && TC_I960 */

  return (seg_reloc_count);
}

#endif /* defined (BFD_ASSEMBLER) || !defined (BFD) */

/* end of write.c */